/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/* Copyright (c) 1990 Mentat Inc. */

#include <sys/types.h>
#include <sys/stream.h>
#include <sys/dlpi.h>
#include <sys/stropts.h>
#include <sys/sysmacros.h>
#include <sys/strsubr.h>
#include <sys/strlog.h>
#include <sys/strsun.h>
#include <sys/zone.h>
#define	_SUN_TPI_VERSION 2
#include <sys/tihdr.h>
#include <sys/xti_inet.h>
#include <sys/ddi.h>
#include <sys/suntpi.h>
#include <sys/cmn_err.h>
#include <sys/debug.h>
#include <sys/kobj.h>
#include <sys/modctl.h>
#include <sys/atomic.h>
#include <sys/policy.h>
#include <sys/priv.h>
#include <sys/taskq.h>

#include <sys/systm.h>
#include <sys/param.h>
#include <sys/kmem.h>
#include <sys/sdt.h>
#include <sys/socket.h>
#include <sys/vtrace.h>
#include <sys/isa_defs.h>
#include <sys/mac.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <net/route.h>
#include <sys/sockio.h>
#include <netinet/in.h>
#include <net/if_dl.h>

#include <inet/common.h>
#include <inet/mi.h>
#include <inet/mib2.h>
#include <inet/nd.h>
#include <inet/arp.h>
#include <inet/snmpcom.h>
#include <inet/optcom.h>
#include <inet/kstatcom.h>

#include <netinet/igmp_var.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <netinet/sctp.h>

#include <inet/ip.h>
#include <inet/ip_impl.h>
#include <inet/ip6.h>
#include <inet/ip6_asp.h>
#include <inet/tcp.h>
#include <inet/tcp_impl.h>
#include <inet/ip_multi.h>
#include <inet/ip_if.h>
#include <inet/ip_ire.h>
#include <inet/ip_ftable.h>
#include <inet/ip_rts.h>
#include <inet/ip_ndp.h>
#include <inet/ip_listutils.h>
#include <netinet/igmp.h>
#include <netinet/ip_mroute.h>
#include <inet/ipp_common.h>

#include <net/pfkeyv2.h>
#include <inet/sadb.h>
#include <inet/ipsec_impl.h>
#include <inet/iptun/iptun_impl.h>
#include <inet/ipdrop.h>
#include <inet/ip_netinfo.h>
#include <inet/ilb_ip.h>

#include <sys/ethernet.h>
#include <net/if_types.h>
#include <sys/cpuvar.h>

#include <ipp/ipp.h>
#include <ipp/ipp_impl.h>
#include <ipp/ipgpc/ipgpc.h>

#include <sys/pattr.h>
#include <inet/ipclassifier.h>
#include <inet/sctp_ip.h>
#include <inet/sctp/sctp_impl.h>
#include <inet/udp_impl.h>
#include <inet/rawip_impl.h>
#include <inet/rts_impl.h>

#include <sys/tsol/label.h>
#include <sys/tsol/tnet.h>

#include <sys/squeue_impl.h>
#include <inet/ip_arp.h>

#include <sys/clock_impl.h>	/* For LBOLT_FASTPATH{,64} */

/*
 * Values for squeue switch:
 * IP_SQUEUE_ENTER_NODRAIN: SQ_NODRAIN
 * IP_SQUEUE_ENTER: SQ_PROCESS
 * IP_SQUEUE_FILL: SQ_FILL
 */
int ip_squeue_enter = IP_SQUEUE_ENTER;	/* Setable in /etc/system */

int ip_squeue_flag;

/*
 * Setable in /etc/system
 */
int ip_poll_normal_ms = 100;
int ip_poll_normal_ticks = 0;
int ip_modclose_ackwait_ms = 3000;

/*
 * It would be nice to have these present only in DEBUG systems, but the
 * current design of the global symbol checking logic requires them to be
 * unconditionally present.
 */
uint_t ip_thread_data;			/* TSD key for debug support */
krwlock_t ip_thread_rwlock;
list_t	ip_thread_list;

/*
 * Structure to represent a linked list of msgblks. Used by ip_snmp_ functions.
 */

struct listptr_s {
	mblk_t	*lp_head;	/* pointer to the head of the list */
	mblk_t	*lp_tail;	/* pointer to the tail of the list */
};

typedef struct listptr_s listptr_t;

/*
 * This is used by ip_snmp_get_mib2_ip_route_media and
 * ip_snmp_get_mib2_ip6_route_media to carry the lists of return data.
 */
typedef struct iproutedata_s {
	uint_t		ird_idx;
	uint_t		ird_flags;	/* see below */
	listptr_t	ird_route;	/* ipRouteEntryTable */
	listptr_t	ird_netmedia;	/* ipNetToMediaEntryTable */
	listptr_t	ird_attrs;	/* ipRouteAttributeTable */
} iproutedata_t;

/* Include ire_testhidden and IRE_IF_CLONE routes */
#define	IRD_REPORT_ALL	0x01

/*
 * Cluster specific hooks. These should be NULL when booted as a non-cluster
 */

/*
 * Hook functions to enable cluster networking
 * On non-clustered systems these vectors must always be NULL.
 *
 * Hook function to Check ip specified ip address is a shared ip address
 * in the cluster
 *
 */
int (*cl_inet_isclusterwide)(netstackid_t stack_id, uint8_t protocol,
    sa_family_t addr_family, uint8_t *laddrp, void *args) = NULL;

/*
 * Hook function to generate cluster wide ip fragment identifier
 */
uint32_t (*cl_inet_ipident)(netstackid_t stack_id, uint8_t protocol,
    sa_family_t addr_family, uint8_t *laddrp, uint8_t *faddrp,
    void *args) = NULL;

/*
 * Hook function to generate cluster wide SPI.
 */
void (*cl_inet_getspi)(netstackid_t, uint8_t, uint8_t *, size_t,
    void *) = NULL;

/*
 * Hook function to verify if the SPI is already utlized.
 */

int (*cl_inet_checkspi)(netstackid_t, uint8_t, uint32_t, void *) = NULL;

/*
 * Hook function to delete the SPI from the cluster wide repository.
 */

void (*cl_inet_deletespi)(netstackid_t, uint8_t, uint32_t, void *) = NULL;

/*
 * Hook function to inform the cluster when packet received on an IDLE SA
 */

void (*cl_inet_idlesa)(netstackid_t, uint8_t, uint32_t, sa_family_t,
    in6_addr_t, in6_addr_t, void *) = NULL;

/*
 * Synchronization notes:
 *
 * IP is a fully D_MP STREAMS module/driver. Thus it does not depend on any
 * MT level protection given by STREAMS. IP uses a combination of its own
 * internal serialization mechanism and standard Solaris locking techniques.
 * The internal serialization is per phyint.  This is used to serialize
 * plumbing operations, IPMP operations, most set ioctls, etc.
 *
 * Plumbing is a long sequence of operations involving message
 * exchanges between IP, ARP and device drivers. Many set ioctls are typically
 * involved in plumbing operations. A natural model is to serialize these
 * ioctls one per ill. For example plumbing of hme0 and qfe0 can go on in
 * parallel without any interference. But various set ioctls on hme0 are best
 * serialized, along with IPMP operations and processing of DLPI control
 * messages received from drivers on a per phyint basis. This serialization is
 * provided by the ipsq_t and primitives operating on this. Details can
 * be found in ip_if.c above the core primitives operating on ipsq_t.
 *
 * Lookups of an ipif or ill by a thread return a refheld ipif / ill.
 * Simiarly lookup of an ire by a thread also returns a refheld ire.
 * In addition ipif's and ill's referenced by the ire are also indirectly
 * refheld. Thus no ipif or ill can vanish as long as an ipif is refheld
 * directly or indirectly. For example an SIOCSLIFADDR ioctl that changes the
 * address of an ipif has to go through the ipsq_t. This ensures that only
 * one such exclusive operation proceeds at any time on the ipif. It then
 * waits for all refcnts
 * associated with this ipif to come down to zero. The address is changed
 * only after the ipif has been quiesced. Then the ipif is brought up again.
 * More details are described above the comment in ip_sioctl_flags.
 *
 * Packet processing is based mostly on IREs and are fully multi-threaded
 * using standard Solaris MT techniques.
 *
 * There are explicit locks in IP to handle:
 * - The ip_g_head list maintained by mi_open_link() and friends.
 *
 * - The reassembly data structures (one lock per hash bucket)
 *
 * - conn_lock is meant to protect conn_t fields. The fields actually
 *   protected by conn_lock are documented in the conn_t definition.
 *
 * - ire_lock to protect some of the fields of the ire, IRE tables
 *   (one lock per hash bucket). Refer to ip_ire.c for details.
 *
 * - ndp_g_lock and ncec_lock for protecting NCEs.
 *
 * - ill_lock protects fields of the ill and ipif. Details in ip.h
 *
 * - ill_g_lock: This is a global reader/writer lock. Protects the following
 *	* The AVL tree based global multi list of all ills.
 *	* The linked list of all ipifs of an ill
 *	* The <ipsq-xop> mapping
 *	* <ill-phyint> association
 *   Insertion/deletion of an ill in the system, insertion/deletion of an ipif
 *   into an ill, changing the <ipsq-xop> mapping of an ill, changing the
 *   <ill-phyint> assoc of an ill will all have to hold the ill_g_lock as
 *   writer for the actual duration of the insertion/deletion/change.
 *
 * - ill_lock:  This is a per ill mutex.
 *   It protects some members of the ill_t struct; see ip.h for details.
 *   It also protects the <ill-phyint> assoc.
 *   It also protects the list of ipifs hanging off the ill.
 *
 * - ipsq_lock: This is a per ipsq_t mutex lock.
 *   This protects some members of the ipsq_t struct; see ip.h for details.
 *   It also protects the <ipsq-ipxop> mapping
 *
 * - ipx_lock: This is a per ipxop_t mutex lock.
 *   This protects some members of the ipxop_t struct; see ip.h for details.
 *
 * - phyint_lock: This is a per phyint mutex lock. Protects just the
 *   phyint_flags
 *
 * - ip_g_nd_lock: This is a global reader/writer lock.
 *   Any call to nd_load to load a new parameter to the ND table must hold the
 *   lock as writer. ND_GET/ND_SET routines that read the ND table hold the lock
 *   as reader.
 *
 * - ip_addr_avail_lock: This is used to ensure the uniqueness of IP addresses.
 *   This lock is held in ipif_up_done and the ipif is marked IPIF_UP and the
 *   uniqueness check also done atomically.
 *
 * - ill_g_usesrc_lock: This readers/writer lock protects the usesrc
 *   group list linked by ill_usesrc_grp_next. It also protects the
 *   ill_usesrc_ifindex field. It is taken as a writer when a member of the
 *   group is being added or deleted.  This lock is taken as a reader when
 *   walking the list/group(eg: to get the number of members in a usesrc group).
 *   Note, it is only necessary to take this lock if the ill_usesrc_grp_next
 *   field is changing state i.e from NULL to non-NULL or vice-versa. For
 *   example, it is not necessary to take this lock in the initial portion
 *   of ip_sioctl_slifusesrc or at all in ip_sioctl_flags since these
 *   operations are executed exclusively and that ensures that the "usesrc
 *   group state" cannot change. The "usesrc group state" change can happen
 *   only in the latter part of ip_sioctl_slifusesrc and in ill_delete.
 *
 * Changing <ill-phyint>, <ipsq-xop> assocications:
 *
 * To change the <ill-phyint> association, the ill_g_lock must be held
 * as writer, and the ill_locks of both the v4 and v6 instance of the ill
 * must be held.
 *
 * To change the <ipsq-xop> association, the ill_g_lock must be held as
 * writer, the ipsq_lock must be held, and one must be writer on the ipsq.
 * This is only done when ills are added or removed from IPMP groups.
 *
 * To add or delete an ipif from the list of ipifs hanging off the ill,
 * ill_g_lock (writer) and ill_lock must be held and the thread must be
 * a writer on the associated ipsq.
 *
 * To add or delete an ill to the system, the ill_g_lock must be held as
 * writer and the thread must be a writer on the associated ipsq.
 *
 * To add or delete an ilm to an ill, the ill_lock must be held and the thread
 * must be a writer on the associated ipsq.
 *
 * Lock hierarchy
 *
 * Some lock hierarchy scenarios are listed below.
 *
 * ill_g_lock -> conn_lock -> ill_lock -> ipsq_lock -> ipx_lock
 * ill_g_lock -> ill_lock(s) -> phyint_lock
 * ill_g_lock -> ndp_g_lock -> ill_lock -> ncec_lock
 * ill_g_lock -> ip_addr_avail_lock
 * conn_lock -> irb_lock -> ill_lock -> ire_lock
 * ill_g_lock -> ip_g_nd_lock
 * ill_g_lock -> ips_ipmp_lock -> ill_lock -> nce_lock
 * ill_g_lock -> ndp_g_lock -> ill_lock -> ncec_lock -> nce_lock
 * arl_lock -> ill_lock
 * ips_ire_dep_lock -> irb_lock
 *
 * When more than 1 ill lock is needed to be held, all ill lock addresses
 * are sorted on address and locked starting from highest addressed lock
 * downward.
 *
 * Multicast scenarios
 * ips_ill_g_lock -> ill_mcast_lock
 * conn_ilg_lock -> ips_ill_g_lock -> ill_lock
 * ill_mcast_serializer -> ill_mcast_lock -> ips_ipmp_lock -> ill_lock
 * ill_mcast_serializer -> ill_mcast_lock -> connf_lock -> conn_lock
 * ill_mcast_serializer -> ill_mcast_lock -> conn_ilg_lock
 * ill_mcast_serializer -> ill_mcast_lock -> ips_igmp_timer_lock
 *
 * IPsec scenarios
 *
 * ipsa_lock -> ill_g_lock -> ill_lock
 * ill_g_usesrc_lock -> ill_g_lock -> ill_lock
 *
 * Trusted Solaris scenarios
 *
 * igsa_lock -> gcgrp_rwlock -> gcgrp_lock
 * igsa_lock -> gcdb_lock
 * gcgrp_rwlock -> ire_lock
 * gcgrp_rwlock -> gcdb_lock
 *
 * squeue(sq_lock), flow related (ft_lock, fe_lock) locking
 *
 * cpu_lock --> ill_lock --> sqset_lock --> sq_lock
 * sq_lock -> conn_lock -> QLOCK(q)
 * ill_lock -> ft_lock -> fe_lock
 *
 * Routing/forwarding table locking notes:
 *
 * Lock acquisition order: Radix tree lock, irb_lock.
 * Requirements:
 * i.  Walker must not hold any locks during the walker callback.
 * ii  Walker must not see a truncated tree during the walk because of any node
 *     deletion.
 * iii Existing code assumes ire_bucket is valid if it is non-null and is used
 *     in many places in the code to walk the irb list. Thus even if all the
 *     ires in a bucket have been deleted, we still can't free the radix node
 *     until the ires have actually been inactive'd (freed).
 *
 * Tree traversal - Need to hold the global tree lock in read mode.
 * Before dropping the global tree lock, need to either increment the ire_refcnt
 * to ensure that the radix node can't be deleted.
 *
 * Tree add - Need to hold the global tree lock in write mode to add a
 * radix node. To prevent the node from being deleted, increment the
 * irb_refcnt, after the node is added to the tree. The ire itself is
 * added later while holding the irb_lock, but not the tree lock.
 *
 * Tree delete - Need to hold the global tree lock and irb_lock in write mode.
 * All associated ires must be inactive (i.e. freed), and irb_refcnt
 * must be zero.
 *
 * Walker - Increment irb_refcnt before calling the walker callback. Hold the
 * global tree lock (read mode) for traversal.
 *
 * IRE dependencies - In some cases we hold ips_ire_dep_lock across ire_refrele
 * hence we will acquire irb_lock while holding ips_ire_dep_lock.
 *
 * IPsec notes :
 *
 * IP interacts with the IPsec code (AH/ESP) by storing IPsec attributes
 * in the ip_xmit_attr_t ip_recv_attr_t. For outbound datagrams, the
 * ip_xmit_attr_t has the
 * information used by the IPsec code for applying the right level of
 * protection. The information initialized by IP in the ip_xmit_attr_t
 * is determined by the per-socket policy or global policy in the system.
 * For inbound datagrams, the ip_recv_attr_t
 * starts out with nothing in it. It gets filled
 * with the right information if it goes through the AH/ESP code, which
 * happens if the incoming packet is secure. The information initialized
 * by AH/ESP, is later used by IP (during fanouts to ULP) to see whether
 * the policy requirements needed by per-socket policy or global policy
 * is met or not.
 *
 * For fully connected sockets i.e dst, src [addr, port] is known,
 * conn_policy_cached is set indicating that policy has been cached.
 * conn_in_enforce_policy may or may not be set depending on whether
 * there is a global policy match or per-socket policy match.
 * Policy inheriting happpens in ip_policy_set once the destination is known.
 * Once the right policy is set on the conn_t, policy cannot change for
 * this socket. This makes life simpler for TCP (UDP ?) where
 * re-transmissions go out with the same policy. For symmetry, policy
 * is cached for fully connected UDP sockets also. Thus if policy is cached,
 * it also implies that policy is latched i.e policy cannot change
 * on these sockets. As we have the right policy on the conn, we don't
 * have to lookup global policy for every outbound and inbound datagram
 * and thus serving as an optimization. Note that a global policy change
 * does not affect fully connected sockets if they have policy. If fully
 * connected sockets did not have any policy associated with it, global
 * policy change may affect them.
 *
 * IP Flow control notes:
 * ---------------------
 * Non-TCP streams are flow controlled by IP. The way this is accomplished
 * differs when ILL_CAPAB_DLD_DIRECT is enabled for that IP instance. When
 * ILL_DIRECT_CAPABLE(ill) is TRUE, IP can do direct function calls into
 * GLDv3. Otherwise packets are sent down to lower layers using STREAMS
 * functions.
 *
 * Per Tx ring udp flow control:
 * This is applicable only when ILL_CAPAB_DLD_DIRECT capability is set in
 * the ill (i.e. ILL_DIRECT_CAPABLE(ill) is true).
 *
 * The underlying link can expose multiple Tx rings to the GLDv3 mac layer.
 * To achieve best performance, outgoing traffic need to be fanned out among
 * these Tx ring. mac_tx() is called (via str_mdata_fastpath_put()) to send
 * traffic out of the NIC and it takes a fanout hint. UDP connections pass
 * the address of connp as fanout hint to mac_tx(). Under flow controlled
 * condition, mac_tx() returns a non-NULL cookie (ip_mac_tx_cookie_t). This
 * cookie points to a specific Tx ring that is blocked. The cookie is used to
 * hash into an idl_tx_list[] entry in idl_tx_list[] array. Each idl_tx_list_t
 * point to drain_lists (idl_t's). These drain list will store the blocked UDP
 * connp's. The drain list is not a single list but a configurable number of
 * lists.
 *
 * The diagram below shows idl_tx_list_t's and their drain_lists. ip_stack_t
 * has an array of idl_tx_list_t. The size of the array is TX_FANOUT_SIZE
 * which is equal to 128. This array in turn contains a pointer to idl_t[],
 * the ip drain list. The idl_t[] array size is MIN(max_ncpus, 8). The drain
 * list will point to the list of connp's that are flow controlled.
 *
 *                      ---------------   -------   -------   -------
 *                   |->|drain_list[0]|-->|connp|-->|connp|-->|connp|-->
 *                   |  ---------------   -------   -------   -------
 *                   |  ---------------   -------   -------   -------
 *                   |->|drain_list[1]|-->|connp|-->|connp|-->|connp|-->
 * ----------------  |  ---------------   -------   -------   -------
 * |idl_tx_list[0]|->|  ---------------   -------   -------   -------
 * ----------------  |->|drain_list[2]|-->|connp|-->|connp|-->|connp|-->
 *                   |  ---------------   -------   -------   -------
 *                   .        .              .         .         .
 *                   |  ---------------   -------   -------   -------
 *                   |->|drain_list[n]|-->|connp|-->|connp|-->|connp|-->
 *                      ---------------   -------   -------   -------
 *                      ---------------   -------   -------   -------
 *                   |->|drain_list[0]|-->|connp|-->|connp|-->|connp|-->
 *                   |  ---------------   -------   -------   -------
 *                   |  ---------------   -------   -------   -------
 * ----------------  |->|drain_list[1]|-->|connp|-->|connp|-->|connp|-->
 * |idl_tx_list[1]|->|  ---------------   -------   -------   -------
 * ----------------  |        .              .         .         .
 *                   |  ---------------   -------   -------   -------
 *                   |->|drain_list[n]|-->|connp|-->|connp|-->|connp|-->
 *                      ---------------   -------   -------   -------
 *     .....
 * ----------------
 * |idl_tx_list[n]|-> ...
 * ----------------
 *
 * When mac_tx() returns a cookie, the cookie is used to hash into a
 * idl_tx_list in ips_idl_tx_list[] array. Then conn_drain_insert() is
 * called passing idl_tx_list. The connp gets inserted in a drain list
 * pointed to by idl_tx_list. conn_drain_list() asserts flow control for
 * the sockets (non stream based) and sets QFULL condition on the conn_wq
 * of streams sockets, or the su_txqfull for non-streams sockets.
 * connp->conn_direct_blocked will be set to indicate the blocked
 * condition.
 *
 * GLDv3 mac layer calls ill_flow_enable() when flow control is relieved.
 * A cookie is passed in the call to ill_flow_enable() that identifies the
 * blocked Tx ring. This cookie is used to get to the idl_tx_list that
 * contains the blocked connp's. conn_walk_drain() uses the idl_tx_list_t
 * and goes through each conn in the drain list and calls conn_idl_remove
 * for the conn to clear the qfull condition for the conn, as well as to
 * remove the conn from the idl list. In addition, streams based sockets
 * will have the conn_wq enabled, causing ip_wsrv to run for the
 * conn. ip_wsrv drains the queued messages, and removes the conn from the
 * drain list, if all messages were drained. It also notifies the
 * conn_upcalls for the conn to signal that flow-control has opened up.
 *
 * In reality the drain list is not a single list, but a configurable number
 * of lists. conn_walk_drain() in the IP module, notifies the conn_upcalls for
 * each conn in the list. conn_drain_insert and conn_drain_tail are the only
 * functions that manipulate this drain list. conn_drain_insert is called in
 * from the protocol layer when conn_ip_output returns EWOULDBLOCK.
 * (as opposed to from ip_wsrv context for STREAMS
 * case -- see below). The synchronization between drain insertion and flow
 * control wakeup is handled by using idl_txl->txl_lock.
 *
 * Flow control using STREAMS:
 * When ILL_DIRECT_CAPABLE() is not TRUE, STREAMS flow control mechanism
 * is used. On the send side, if the packet cannot be sent down to the
 * driver by IP, because of a canput failure, ip_xmit drops the packet
 * and returns EWOULDBLOCK to the caller, who may then invoke
 * ixa_check_drain_insert to insert the conn on the 0'th drain list.
 * When ip_wsrv runs on the ill_wq because flow control has been relieved, the
 * blocked conns in the * 0'th drain list is drained as with the
 * non-STREAMS case.
 *
 * In both the STREAMS and non-STREAMS case, the sockfs upcall to set
 * qfull is done when the conn is inserted into the drain list
 * (conn_drain_insert()) and cleared when the conn is removed from the drain
 * list (conn_idl_remove()).
 *
 * IPQOS notes:
 *
 * IPQoS Policies are applied to packets using IPPF (IP Policy framework)
 * and IPQoS modules. IPPF includes hooks in IP at different control points
 * (callout positions) which direct packets to IPQoS modules for policy
 * processing. Policies, if present, are global.
 *
 * The callout positions are located in the following paths:
 *		o local_in (packets destined for this host)
 *		o local_out (packets orginating from this host )
 *		o fwd_in  (packets forwarded by this m/c - inbound)
 *		o fwd_out (packets forwarded by this m/c - outbound)
 * Hooks at these callout points can be enabled/disabled using the ndd variable
 * ip_policy_mask (a bit mask with the 4 LSB indicating the callout positions).
 * By default all the callout positions are enabled.
 *
 * Outbound (local_out)
 * Hooks are placed in ire_send_wire_v4 and ire_send_wire_v6.
 *
 * Inbound (local_in)
 * Hooks are placed in ip_fanout_v4 and ip_fanout_v6.
 *
 * Forwarding (in and out)
 * Hooks are placed in ire_recv_forward_v4/v6.
 *
 * IP Policy Framework processing (IPPF processing)
 * Policy processing for a packet is initiated by ip_process, which ascertains
 * that the classifier (ipgpc) is loaded and configured, failing which the
 * packet resumes normal processing in IP. If the clasifier is present, the
 * packet is acted upon by one or more IPQoS modules (action instances), per
 * filters configured in ipgpc and resumes normal IP processing thereafter.
 * An action instance can drop a packet in course of its processing.
 *
 * Zones notes:
 *
 * The partitioning rules for networking are as follows:
 * 1) Packets coming from a zone must have a source address belonging to that
 * zone.
 * 2) Packets coming from a zone can only be sent on a physical interface on
 * which the zone has an IP address.
 * 3) Between two zones on the same machine, packet delivery is only allowed if
 * there's a matching route for the destination and zone in the forwarding
 * table.
 * 4) The TCP and UDP port spaces are per-zone; that is, two processes in
 * different zones can bind to the same port with the wildcard address
 * (INADDR_ANY).
 *
 * The granularity of interface partitioning is at the logical interface level.
 * Therefore, every zone has its own IP addresses, and incoming packets can be
 * attributed to a zone unambiguously. A logical interface is placed into a zone
 * using the SIOCSLIFZONE ioctl; this sets the ipif_zoneid field in the ipif_t
 * structure. Rule (1) is implemented by modifying the source address selection
 * algorithm so that the list of eligible addresses is filtered based on the
 * sending process zone.
 *
 * The Internet Routing Entries (IREs) are either exclusive to a zone or shared
 * across all zones, depending on their type. Here is the break-up:
 *
 * IRE type				Shared/exclusive
 * --------				----------------
 * IRE_BROADCAST			Exclusive
 * IRE_DEFAULT (default routes)		Shared (*)
 * IRE_LOCAL				Exclusive (x)
 * IRE_LOOPBACK				Exclusive
 * IRE_PREFIX (net routes)		Shared (*)
 * IRE_IF_NORESOLVER (interface routes)	Exclusive
 * IRE_IF_RESOLVER (interface routes)	Exclusive
 * IRE_IF_CLONE (interface routes)	Exclusive
 * IRE_HOST (host routes)		Shared (*)
 *
 * (*) A zone can only use a default or off-subnet route if the gateway is
 * directly reachable from the zone, that is, if the gateway's address matches
 * one of the zone's logical interfaces.
 *
 * (x) IRE_LOCAL are handled a bit differently.
 * When ip_restrict_interzone_loopback is set (the default),
 * ire_route_recursive restricts loopback using an IRE_LOCAL
 * between zone to the case when L2 would have conceptually looped the packet
 * back, i.e. the loopback which is required since neither Ethernet drivers
 * nor Ethernet hardware loops them back. This is the case when the normal
 * routes (ignoring IREs with different zoneids) would send out the packet on
 * the same ill as the ill with which is IRE_LOCAL is associated.
 *
 * Multiple zones can share a common broadcast address; typically all zones
 * share the 255.255.255.255 address. Incoming as well as locally originated
 * broadcast packets must be dispatched to all the zones on the broadcast
 * network. For directed broadcasts (e.g. 10.16.72.255) this is not trivial
 * since some zones may not be on the 10.16.72/24 network. To handle this, each
 * zone has its own set of IRE_BROADCAST entries; then, broadcast packets are
 * sent to every zone that has an IRE_BROADCAST entry for the destination
 * address on the input ill, see ip_input_broadcast().
 *
 * Applications in different zones can join the same multicast group address.
 * The same logic applies for multicast as for broadcast. ip_input_multicast
 * dispatches packets to all zones that have members on the physical interface.
 */

/*
 * Squeue Fanout flags:
 *	0: No fanout.
 *	1: Fanout across all squeues
 */
boolean_t	ip_squeue_fanout = 0;

/*
 * Maximum dups allowed per packet.
 */
uint_t ip_max_frag_dups = 10;

/* RFC 1122 Conformance */
#define	IP_FORWARD_DEFAULT	IP_FORWARD_NEVER

#define	ILL_MAX_NAMELEN			LIFNAMSIZ

static int	ip_open(queue_t *q, dev_t *devp, int flag, int sflag,
		    cred_t *credp, boolean_t isv6);
static mblk_t	*ip_xmit_attach_llhdr(mblk_t *, nce_t *);

static boolean_t icmp_inbound_verify_v4(mblk_t *, icmph_t *, ip_recv_attr_t *);
static void	icmp_inbound_too_big_v4(icmph_t *, ip_recv_attr_t *);
static void	icmp_inbound_error_fanout_v4(mblk_t *, icmph_t *,
    ip_recv_attr_t *);
static void	icmp_options_update(ipha_t *);
static void	icmp_param_problem(mblk_t *, uint8_t,  ip_recv_attr_t *);
static void	icmp_pkt(mblk_t *, void *, size_t, ip_recv_attr_t *);
static mblk_t	*icmp_pkt_err_ok(mblk_t *, ip_recv_attr_t *);
static void	icmp_redirect_v4(mblk_t *mp, ipha_t *, icmph_t *,
    ip_recv_attr_t *);
static void	icmp_send_redirect(mblk_t *, ipaddr_t, ip_recv_attr_t *);
static void	icmp_send_reply_v4(mblk_t *, ipha_t *, icmph_t *,
    ip_recv_attr_t *);

mblk_t		*ip_dlpi_alloc(size_t, t_uscalar_t);
char		*ip_dot_addr(ipaddr_t, char *);
mblk_t		*ip_carve_mp(mblk_t **, ssize_t);
int		ip_close(queue_t *, int);
static char	*ip_dot_saddr(uchar_t *, char *);
static void	ip_lrput(queue_t *, mblk_t *);
ipaddr_t	ip_net_mask(ipaddr_t);
char		*ip_nv_lookup(nv_t *, int);
static int	ip_param_get(queue_t *, mblk_t *, caddr_t, cred_t *);
static int	ip_param_generic_get(queue_t *, mblk_t *, caddr_t, cred_t *);
static boolean_t	ip_param_register(IDP *ndp, ipparam_t *, size_t,
    ipndp_t *, size_t);
static int	ip_param_set(queue_t *, mblk_t *, char *, caddr_t, cred_t *);
void	ip_rput(queue_t *, mblk_t *);
static void	ip_rput_dlpi_writer(ipsq_t *dummy_sq, queue_t *q, mblk_t *mp,
		    void *dummy_arg);
int		ip_snmp_get(queue_t *, mblk_t *, int);
static mblk_t	*ip_snmp_get_mib2_ip(queue_t *, mblk_t *,
		    mib2_ipIfStatsEntry_t *, ip_stack_t *);
static mblk_t	*ip_snmp_get_mib2_ip_traffic_stats(queue_t *, mblk_t *,
		    ip_stack_t *);
static mblk_t	*ip_snmp_get_mib2_ip6(queue_t *, mblk_t *, ip_stack_t *);
static mblk_t	*ip_snmp_get_mib2_icmp(queue_t *, mblk_t *, ip_stack_t *ipst);
static mblk_t	*ip_snmp_get_mib2_icmp6(queue_t *, mblk_t *, ip_stack_t *ipst);
static mblk_t	*ip_snmp_get_mib2_igmp(queue_t *, mblk_t *, ip_stack_t *ipst);
static mblk_t	*ip_snmp_get_mib2_multi(queue_t *, mblk_t *, ip_stack_t *ipst);
static mblk_t	*ip_snmp_get_mib2_ip_addr(queue_t *, mblk_t *,
		    ip_stack_t *ipst);
static mblk_t	*ip_snmp_get_mib2_ip6_addr(queue_t *, mblk_t *,
		    ip_stack_t *ipst);
static mblk_t	*ip_snmp_get_mib2_ip_group_src(queue_t *, mblk_t *,
		    ip_stack_t *ipst);
static mblk_t	*ip_snmp_get_mib2_ip6_group_src(queue_t *, mblk_t *,
		    ip_stack_t *ipst);
static mblk_t	*ip_snmp_get_mib2_ip_group_mem(queue_t *, mblk_t *,
		    ip_stack_t *ipst);
static mblk_t	*ip_snmp_get_mib2_ip6_group_mem(queue_t *, mblk_t *,
		    ip_stack_t *ipst);
static mblk_t	*ip_snmp_get_mib2_virt_multi(queue_t *, mblk_t *,
		    ip_stack_t *ipst);
static mblk_t	*ip_snmp_get_mib2_multi_rtable(queue_t *, mblk_t *,
		    ip_stack_t *ipst);
static mblk_t	*ip_snmp_get_mib2_ip_route_media(queue_t *, mblk_t *, int,
		    ip_stack_t *ipst);
static mblk_t	*ip_snmp_get_mib2_ip6_route_media(queue_t *, mblk_t *, int,
		    ip_stack_t *ipst);
static void	ip_snmp_get2_v4(ire_t *, iproutedata_t *);
static void	ip_snmp_get2_v6_route(ire_t *, iproutedata_t *);
static int	ip_snmp_get2_v4_media(ncec_t *, iproutedata_t *);
static int	ip_snmp_get2_v6_media(ncec_t *, iproutedata_t *);
int		ip_snmp_set(queue_t *, int, int, uchar_t *, int);

static mblk_t	*ip_fragment_copyhdr(uchar_t *, int, int, ip_stack_t *,
		    mblk_t *);

static void	conn_drain_init(ip_stack_t *);
static void	conn_drain_fini(ip_stack_t *);
static void	conn_drain_tail(conn_t *connp, boolean_t closing);

static void	conn_walk_drain(ip_stack_t *, idl_tx_list_t *);
static void	conn_walk_sctp(pfv_t, void *, zoneid_t, netstack_t *);

static void	*ip_stack_init(netstackid_t stackid, netstack_t *ns);
static void	ip_stack_shutdown(netstackid_t stackid, void *arg);
static void	ip_stack_fini(netstackid_t stackid, void *arg);

static int	ip_forward_set(queue_t *, mblk_t *, char *, caddr_t, cred_t *);

static int	ip_multirt_apply_membership(int (*fn)(conn_t *, boolean_t,
    const in6_addr_t *, ipaddr_t, uint_t, mcast_record_t, const in6_addr_t *),
    ire_t *, conn_t *, boolean_t, const in6_addr_t *,  mcast_record_t,
    const in6_addr_t *);

static int	ip_cgtp_filter_get(queue_t *, mblk_t *, caddr_t, cred_t *);
static int	ip_cgtp_filter_set(queue_t *, mblk_t *, char *,
    caddr_t, cred_t *);
static int	ip_input_proc_set(queue_t *q, mblk_t *mp, char *value,
    caddr_t cp, cred_t *cr);
static int	ip_int_set(queue_t *, mblk_t *, char *, caddr_t,
    cred_t *);
static int	ip_squeue_switch(int);

static void	*ip_kstat_init(netstackid_t, ip_stack_t *);
static void	ip_kstat_fini(netstackid_t, kstat_t *);
static int	ip_kstat_update(kstat_t *kp, int rw);
static void	*icmp_kstat_init(netstackid_t);
static void	icmp_kstat_fini(netstackid_t, kstat_t *);
static int	icmp_kstat_update(kstat_t *kp, int rw);
static void	*ip_kstat2_init(netstackid_t, ip_stat_t *);
static void	ip_kstat2_fini(netstackid_t, kstat_t *);

static void	ipobs_init(ip_stack_t *);
static void	ipobs_fini(ip_stack_t *);

ipaddr_t	ip_g_all_ones = IP_HOST_MASK;

/* How long, in seconds, we allow frags to hang around. */
#define	IP_FRAG_TIMEOUT		15
#define	IPV6_FRAG_TIMEOUT	60

static long ip_rput_pullups;
int	dohwcksum = 1;	/* use h/w cksum if supported by the hardware */

vmem_t *ip_minor_arena_sa; /* for minor nos. from INET_MIN_DEV+2 thru 2^^18-1 */
vmem_t *ip_minor_arena_la; /* for minor nos. from 2^^18 thru 2^^32-1 */

int	ip_debug;

/*
 * Multirouting/CGTP stuff
 */
int	ip_cgtp_filter_rev = CGTP_FILTER_REV;	/* CGTP hooks version */

/*
 * Named Dispatch Parameter Table.
 * All of these are alterable, within the min/max values given, at run time.
 */
static ipparam_t	lcl_param_arr[] = {
	/* min	max	value	name */
	{  0,	1,	0,	"ip_respond_to_address_mask_broadcast"},
	{  0,	1,	1,	"ip_respond_to_echo_broadcast"},
	{  0,	1,	1,	"ip_respond_to_echo_multicast"},
	{  0,	1,	0,	"ip_respond_to_timestamp"},
	{  0,	1,	0,	"ip_respond_to_timestamp_broadcast"},
	{  0,	1,	1,	"ip_send_redirects"},
	{  0,	1,	0,	"ip_forward_directed_broadcasts"},
	{  0,	10,	0,	"ip_mrtdebug"},
	{  1,	8,	3,	"ip_ire_reclaim_fraction" },
	{  1,	8,	3,	"ip_nce_reclaim_fraction" },
	{  1,	8,	3,	"ip_dce_reclaim_fraction" },
	{  1,	255,	255,	"ip_def_ttl" },
	{  0,	1,	0,	"ip_forward_src_routed"},
	{  0,	256,	32,	"ip_wroff_extra" },
	{  2, 999999999, 60*20, "ip_pathmtu_interval" },	/* In seconds */
	{  8,	65536,  64,	"ip_icmp_return_data_bytes" },
	{  0,	1,	1,	"ip_path_mtu_discovery" },
	{ 68,	65535,	576,	"ip_pmtu_min" },
	{  0,	1,	0,	"ip_ignore_redirect" },
	{  0,	1,	0,	"ip_arp_icmp_error" },
	{  1,	254,	1,	"ip_broadcast_ttl" },
	{  0,	99999,	100,	"ip_icmp_err_interval" },
	{  1,	99999,	10,	"ip_icmp_err_burst" },
	{  0,	999999999,	1000000, "ip_reass_queue_bytes" },
	{  0,	1,	0,	"ip_strict_dst_multihoming" },
	{  1,	MAX_ADDRS_PER_IF,	256,	"ip_addrs_per_if"},
	{  0,	1,	0,	"ipsec_override_persocket_policy" },
	{  0,	1,	1,	"icmp_accept_clear_messages" },
	{  0,	1,	1,	"igmp_accept_clear_messages" },
	{  2,	999999999, ND_DELAY_FIRST_PROBE_TIME,
				"ip_ndp_delay_first_probe_time"},
	{  1,	999999999, ND_MAX_UNICAST_SOLICIT,
				"ip_ndp_max_unicast_solicit"},
	{  1,	255,	IPV6_MAX_HOPS,	"ip6_def_hops" },
	{  8,	IPV6_MIN_MTU,	IPV6_MIN_MTU, "ip6_icmp_return_data_bytes" },
	{  0,	1,	0,	"ip6_forward_src_routed"},
	{  0,	1,	1,	"ip6_respond_to_echo_multicast"},
	{  0,	1,	1,	"ip6_send_redirects"},
	{  0,	1,	0,	"ip6_ignore_redirect" },
	{  0,	1,	0,	"ip6_strict_dst_multihoming" },

	{  0,	2,	2,	"ip_src_check" },

	{  0,	999999,	1000,	"ipsec_policy_log_interval" },

	{  0,	1,	1,	"pim_accept_clear_messages" },
	{  1000, 20000,	2000,	"ip_ndp_unsolicit_interval" },
	{  1,	20,	3,	"ip_ndp_unsolicit_count" },
	{  0,	1,	1,	"ip6_ignore_home_address_opt" },
	{  0,	15,	0,	"ip_policy_mask" },
	{  0,	2,	2,	"ip_ecmp_behavior" },
	{  0,	255,	1,	"ip_multirt_ttl" },
	{  0,	3600,	60,	"ip_ire_badcnt_lifetime" },	/* In seconds */
	{  0,	999999,	60*60*24, "ip_max_temp_idle" },
	{  0,	1000,	1,	"ip_max_temp_defend" },
	/*
	 * when a conflict of an active address is detected,
	 * defend up to ip_max_defend times, within any
	 * ip_defend_interval span.
	 */
	{  0,	1000,	3,	"ip_max_defend" },
	{  0,	999999,	30,	"ip_defend_interval" },
	{  0,	3600000, 300000, "ip_dup_recovery" },
	{  0,	1,	1,	"ip_restrict_interzone_loopback" },
	{  0,	1,	1,	"ip_lso_outbound" },
	{  IGMP_V1_ROUTER, IGMP_V3_ROUTER, IGMP_V3_ROUTER, "igmp_max_version" },
	{  MLD_V1_ROUTER, MLD_V2_ROUTER, MLD_V2_ROUTER, "mld_max_version" },
#ifdef DEBUG
	{  0,	1,	0,	"ip6_drop_inbound_icmpv6" },
#else
	{  0,	0,	0,	"" },
#endif
	/* delay before sending first probe: */
	{  0,	20000,	1000,	"arp_probe_delay" },
	{  0,	20000,	100,	"arp_fastprobe_delay" },
	/* interval at which DAD probes are sent: */
	{ 10,	20000,	1500,	"arp_probe_interval" },
	{ 10,	20000,	150,	"arp_fastprobe_interval" },
	/* setting probe count to 0 will disable ARP probing for DAD. */
	{  0,	20,	3,	"arp_probe_count" },
	{  0,	20,	3,	"arp_fastprobe_count" },

	{  0,	3600000, 15000,	"ipv4_dad_announce_interval"},
	{  0,	3600000, 15000,	"ipv6_dad_announce_interval"},
	/*
	 * Rate limiting parameters for DAD defense used in
	 * ill_defend_rate_limit():
	 * defend_rate : pkts/hour permitted
	 * defend_interval : time that can elapse before we send out a
	 *			DAD defense.
	 * defend_period: denominator for defend_rate (in seconds).
	 */
	{  0,	3600000, 300000,	"arp_defend_interval"},
	{  0,	20000, 100,		"arp_defend_rate"},
	{  0,	3600000, 300000,	"ndp_defend_interval"},
	{  0,	20000, 100,		"ndp_defend_rate"},
	{  5,	86400,	3600,		"arp_defend_period"},
	{  5,	86400,	3600,		"ndp_defend_period"},
	{  0,	1,	1,		"ipv4_icmp_return_pmtu" },
	{  0,	1,	1,		"ipv6_icmp_return_pmtu" },
	/*
	 * publish count/interval values used to announce local addresses
	 * for IPv4, IPv6.
	 */
	{  1,	20,	5,	"ip_arp_publish_count" },
	{  1000, 20000,	2000,	"ip_arp_publish_interval" },
};

/*
 * Extended NDP table
 * The addresses for the first two are filled in to be ips_ip_g_forward
 * and ips_ipv6_forward at init time.
 */
static ipndp_t	lcl_ndp_arr[] = {
	/* getf			setf		data			name */
#define	IPNDP_IP_FORWARDING_OFFSET	0
	{  ip_param_generic_get,	ip_forward_set,	NULL,
	    "ip_forwarding" },
#define	IPNDP_IP6_FORWARDING_OFFSET	1
	{  ip_param_generic_get,	ip_forward_set,	NULL,
	    "ip6_forwarding" },
	{ ip_param_generic_get, ip_input_proc_set,
	    (caddr_t)&ip_squeue_enter, "ip_squeue_enter" },
	{ ip_param_generic_get, ip_int_set,
	    (caddr_t)&ip_squeue_fanout, "ip_squeue_fanout" },
#define	IPNDP_CGTP_FILTER_OFFSET	4
	{  ip_cgtp_filter_get,	ip_cgtp_filter_set, NULL,
	    "ip_cgtp_filter" },
	{  ip_param_generic_get, ip_int_set, (caddr_t)&ip_debug,
	    "ip_debug" },
};

/*
 * Table of IP ioctls encoding the various properties of the ioctl and
 * indexed based on the last byte of the ioctl command. Occasionally there
 * is a clash, and there is more than 1 ioctl with the same last byte.
 * In such a case 1 ioctl is encoded in the ndx table and the remaining
 * ioctls are encoded in the misc table. An entry in the ndx table is
 * retrieved by indexing on the last byte of the ioctl command and comparing
 * the ioctl command with the value in the ndx table. In the event of a
 * mismatch the misc table is then searched sequentially for the desired
 * ioctl command.
 *
 * Entry: <command> <copyin_size> <flags> <cmd_type> <function> <restart_func>
 */
ip_ioctl_cmd_t ip_ndx_ioctl_table[] = {
	/* 000 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 001 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 002 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 003 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 004 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 005 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 006 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 007 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 008 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 009 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

	/* 010 */ { SIOCADDRT,	sizeof (struct rtentry), IPI_PRIV,
			MISC_CMD, ip_siocaddrt, NULL },
	/* 011 */ { SIOCDELRT,	sizeof (struct rtentry), IPI_PRIV,
			MISC_CMD, ip_siocdelrt, NULL },

	/* 012 */ { SIOCSIFADDR, sizeof (struct ifreq), IPI_PRIV | IPI_WR,
			IF_CMD, ip_sioctl_addr, ip_sioctl_addr_restart },
	/* 013 */ { SIOCGIFADDR, sizeof (struct ifreq), IPI_GET_CMD,
			IF_CMD, ip_sioctl_get_addr, NULL },

	/* 014 */ { SIOCSIFDSTADDR, sizeof (struct ifreq), IPI_PRIV | IPI_WR,
			IF_CMD, ip_sioctl_dstaddr, ip_sioctl_dstaddr_restart },
	/* 015 */ { SIOCGIFDSTADDR, sizeof (struct ifreq),
			IPI_GET_CMD, IF_CMD, ip_sioctl_get_dstaddr, NULL },

	/* 016 */ { SIOCSIFFLAGS, sizeof (struct ifreq),
			IPI_PRIV | IPI_WR,
			IF_CMD, ip_sioctl_flags, ip_sioctl_flags_restart },
	/* 017 */ { SIOCGIFFLAGS, sizeof (struct ifreq),
			IPI_MODOK | IPI_GET_CMD,
			IF_CMD, ip_sioctl_get_flags, NULL },

	/* 018 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 019 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

	/* copyin size cannot be coded for SIOCGIFCONF */
	/* 020 */ { O_SIOCGIFCONF, 0, IPI_GET_CMD,
			MISC_CMD, ip_sioctl_get_ifconf, NULL },

	/* 021 */ { SIOCSIFMTU,	sizeof (struct ifreq), IPI_PRIV | IPI_WR,
			IF_CMD, ip_sioctl_mtu, NULL },
	/* 022 */ { SIOCGIFMTU,	sizeof (struct ifreq), IPI_GET_CMD,
			IF_CMD, ip_sioctl_get_mtu, NULL },
	/* 023 */ { SIOCGIFBRDADDR, sizeof (struct ifreq),
			IPI_GET_CMD, IF_CMD, ip_sioctl_get_brdaddr, NULL },
	/* 024 */ { SIOCSIFBRDADDR, sizeof (struct ifreq), IPI_PRIV | IPI_WR,
			IF_CMD, ip_sioctl_brdaddr, NULL },
	/* 025 */ { SIOCGIFNETMASK, sizeof (struct ifreq),
			IPI_GET_CMD, IF_CMD, ip_sioctl_get_netmask, NULL },
	/* 026 */ { SIOCSIFNETMASK, sizeof (struct ifreq), IPI_PRIV | IPI_WR,
			IF_CMD, ip_sioctl_netmask, ip_sioctl_netmask_restart },
	/* 027 */ { SIOCGIFMETRIC, sizeof (struct ifreq),
			IPI_GET_CMD, IF_CMD, ip_sioctl_get_metric, NULL },
	/* 028 */ { SIOCSIFMETRIC, sizeof (struct ifreq), IPI_PRIV,
			IF_CMD, ip_sioctl_metric, NULL },
	/* 029 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

	/* See 166-168 below for extended SIOC*XARP ioctls */
	/* 030 */ { SIOCSARP, sizeof (struct arpreq), IPI_PRIV | IPI_WR,
			ARP_CMD, ip_sioctl_arp, NULL },
	/* 031 */ { SIOCGARP, sizeof (struct arpreq), IPI_GET_CMD,
			ARP_CMD, ip_sioctl_arp, NULL },
	/* 032 */ { SIOCDARP, sizeof (struct arpreq), IPI_PRIV | IPI_WR,
			ARP_CMD, ip_sioctl_arp, NULL },

	/* 033 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 034 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 035 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 036 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 037 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 038 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 039 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 040 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 041 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 042 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 043 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 044 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 045 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 046 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 047 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 048 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 049 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 050 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 051 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 052 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 053 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

	/* 054 */ { IF_UNITSEL,	sizeof (int), IPI_PRIV | IPI_WR | IPI_MODOK,
			MISC_CMD, if_unitsel, if_unitsel_restart },

	/* 055 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 056 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 057 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 058 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 059 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 060 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 061 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 062 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 063 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 064 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 065 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 066 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 067 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 068 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 069 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 070 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 071 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 072 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

	/* 073 */ { SIOCSIFNAME, sizeof (struct ifreq),
			IPI_PRIV | IPI_WR | IPI_MODOK,
			IF_CMD, ip_sioctl_sifname, NULL },

	/* 074 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 075 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 076 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 077 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 078 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 079 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 080 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 081 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 082 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 083 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 084 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 085 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 086 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

	/* 087 */ { SIOCGIFNUM, sizeof (int), IPI_GET_CMD,
			MISC_CMD, ip_sioctl_get_ifnum, NULL },
	/* 088 */ { SIOCGIFMUXID, sizeof (struct ifreq), IPI_GET_CMD,
			IF_CMD, ip_sioctl_get_muxid, NULL },
	/* 089 */ { SIOCSIFMUXID, sizeof (struct ifreq),
			IPI_PRIV | IPI_WR, IF_CMD, ip_sioctl_muxid, NULL },

	/* Both if and lif variants share same func */
	/* 090 */ { SIOCGIFINDEX, sizeof (struct ifreq), IPI_GET_CMD,
			IF_CMD, ip_sioctl_get_lifindex, NULL },
	/* Both if and lif variants share same func */
	/* 091 */ { SIOCSIFINDEX, sizeof (struct ifreq),
			IPI_PRIV | IPI_WR, IF_CMD, ip_sioctl_slifindex, NULL },

	/* copyin size cannot be coded for SIOCGIFCONF */
	/* 092 */ { SIOCGIFCONF, 0, IPI_GET_CMD,
			MISC_CMD, ip_sioctl_get_ifconf, NULL },
	/* 093 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 094 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 095 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 096 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 097 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 098 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 099 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 100 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 101 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 102 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 103 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 104 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 105 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 106 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 107 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 108 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 109 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

	/* 110 */ { SIOCLIFREMOVEIF, sizeof (struct lifreq),
			IPI_PRIV | IPI_WR, LIF_CMD, ip_sioctl_removeif,
			ip_sioctl_removeif_restart },
	/* 111 */ { SIOCLIFADDIF, sizeof (struct lifreq),
			IPI_GET_CMD | IPI_PRIV | IPI_WR,
			LIF_CMD, ip_sioctl_addif, NULL },
#define	SIOCLIFADDR_NDX 112
	/* 112 */ { SIOCSLIFADDR, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
			LIF_CMD, ip_sioctl_addr, ip_sioctl_addr_restart },
	/* 113 */ { SIOCGLIFADDR, sizeof (struct lifreq),
			IPI_GET_CMD, LIF_CMD, ip_sioctl_get_addr, NULL },
	/* 114 */ { SIOCSLIFDSTADDR, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
			LIF_CMD, ip_sioctl_dstaddr, ip_sioctl_dstaddr_restart },
	/* 115 */ { SIOCGLIFDSTADDR, sizeof (struct lifreq),
			IPI_GET_CMD, LIF_CMD, ip_sioctl_get_dstaddr, NULL },
	/* 116 */ { SIOCSLIFFLAGS, sizeof (struct lifreq),
			IPI_PRIV | IPI_WR,
			LIF_CMD, ip_sioctl_flags, ip_sioctl_flags_restart },
	/* 117 */ { SIOCGLIFFLAGS, sizeof (struct lifreq),
			IPI_GET_CMD | IPI_MODOK,
			LIF_CMD, ip_sioctl_get_flags, NULL },

	/* 118 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 119 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

	/* 120 */ { O_SIOCGLIFCONF, 0, IPI_GET_CMD, MISC_CMD,
			ip_sioctl_get_lifconf, NULL },
	/* 121 */ { SIOCSLIFMTU, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
			LIF_CMD, ip_sioctl_mtu, NULL },
	/* 122 */ { SIOCGLIFMTU, sizeof (struct lifreq), IPI_GET_CMD,
			LIF_CMD, ip_sioctl_get_mtu, NULL },
	/* 123 */ { SIOCGLIFBRDADDR, sizeof (struct lifreq),
			IPI_GET_CMD, LIF_CMD, ip_sioctl_get_brdaddr, NULL },
	/* 124 */ { SIOCSLIFBRDADDR, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
			LIF_CMD, ip_sioctl_brdaddr, NULL },
	/* 125 */ { SIOCGLIFNETMASK, sizeof (struct lifreq),
			IPI_GET_CMD, LIF_CMD, ip_sioctl_get_netmask, NULL },
	/* 126 */ { SIOCSLIFNETMASK, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
			LIF_CMD, ip_sioctl_netmask, ip_sioctl_netmask_restart },
	/* 127 */ { SIOCGLIFMETRIC, sizeof (struct lifreq),
			IPI_GET_CMD, LIF_CMD, ip_sioctl_get_metric, NULL },
	/* 128 */ { SIOCSLIFMETRIC, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
			LIF_CMD, ip_sioctl_metric, NULL },
	/* 129 */ { SIOCSLIFNAME, sizeof (struct lifreq),
			IPI_PRIV | IPI_WR | IPI_MODOK,
			LIF_CMD, ip_sioctl_slifname,
			ip_sioctl_slifname_restart },

	/* 130 */ { SIOCGLIFNUM, sizeof (struct lifnum), IPI_GET_CMD,
			MISC_CMD, ip_sioctl_get_lifnum, NULL },
	/* 131 */ { SIOCGLIFMUXID, sizeof (struct lifreq),
			IPI_GET_CMD, LIF_CMD, ip_sioctl_get_muxid, NULL },
	/* 132 */ { SIOCSLIFMUXID, sizeof (struct lifreq),
			IPI_PRIV | IPI_WR, LIF_CMD, ip_sioctl_muxid, NULL },
	/* 133 */ { SIOCGLIFINDEX, sizeof (struct lifreq),
			IPI_GET_CMD, LIF_CMD, ip_sioctl_get_lifindex, 0 },
	/* 134 */ { SIOCSLIFINDEX, sizeof (struct lifreq),
			IPI_PRIV | IPI_WR, LIF_CMD, ip_sioctl_slifindex, 0 },
	/* 135 */ { SIOCSLIFTOKEN, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
			LIF_CMD, ip_sioctl_token, NULL },
	/* 136 */ { SIOCGLIFTOKEN, sizeof (struct lifreq),
			IPI_GET_CMD, LIF_CMD, ip_sioctl_get_token, NULL },
	/* 137 */ { SIOCSLIFSUBNET, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
			LIF_CMD, ip_sioctl_subnet, ip_sioctl_subnet_restart },
	/* 138 */ { SIOCGLIFSUBNET, sizeof (struct lifreq),
			IPI_GET_CMD, LIF_CMD, ip_sioctl_get_subnet, NULL },
	/* 139 */ { SIOCSLIFLNKINFO, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
			LIF_CMD, ip_sioctl_lnkinfo, NULL },

	/* 140 */ { SIOCGLIFLNKINFO, sizeof (struct lifreq),
			IPI_GET_CMD, LIF_CMD, ip_sioctl_get_lnkinfo, NULL },
	/* 141 */ { SIOCLIFDELND, sizeof (struct lifreq), IPI_PRIV,
			LIF_CMD, ip_siocdelndp_v6, NULL },
	/* 142 */ { SIOCLIFGETND, sizeof (struct lifreq), IPI_GET_CMD,
			LIF_CMD, ip_siocqueryndp_v6, NULL },
	/* 143 */ { SIOCLIFSETND, sizeof (struct lifreq), IPI_PRIV,
			LIF_CMD, ip_siocsetndp_v6, NULL },
	/* 144 */ { SIOCTMYADDR, sizeof (struct sioc_addrreq), IPI_GET_CMD,
			MISC_CMD, ip_sioctl_tmyaddr, NULL },
	/* 145 */ { SIOCTONLINK, sizeof (struct sioc_addrreq), IPI_GET_CMD,
			MISC_CMD, ip_sioctl_tonlink, NULL },
	/* 146 */ { SIOCTMYSITE, sizeof (struct sioc_addrreq), 0,
			MISC_CMD, ip_sioctl_tmysite, NULL },
	/* 147 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 148 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* IPSECioctls handled in ip_sioctl_copyin_setup itself */
	/* 149 */ { SIOCFIPSECONFIG, 0, IPI_PRIV, MISC_CMD, NULL, NULL },
	/* 150 */ { SIOCSIPSECONFIG, 0, IPI_PRIV, MISC_CMD, NULL, NULL },
	/* 151 */ { SIOCDIPSECONFIG, 0, IPI_PRIV, MISC_CMD, NULL, NULL },
	/* 152 */ { SIOCLIPSECONFIG, 0, IPI_PRIV, MISC_CMD, NULL, NULL },

	/* 153 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

	/* 154 */ { SIOCGLIFBINDING, sizeof (struct lifreq), IPI_GET_CMD,
			LIF_CMD, ip_sioctl_get_binding, NULL },
	/* 155 */ { SIOCSLIFGROUPNAME, sizeof (struct lifreq),
			IPI_PRIV | IPI_WR,
			LIF_CMD, ip_sioctl_groupname, ip_sioctl_groupname },
	/* 156 */ { SIOCGLIFGROUPNAME, sizeof (struct lifreq),
			IPI_GET_CMD, LIF_CMD, ip_sioctl_get_groupname, NULL },
	/* 157 */ { SIOCGLIFGROUPINFO, sizeof (lifgroupinfo_t),
			IPI_GET_CMD, MISC_CMD, ip_sioctl_groupinfo, NULL },

	/* Leave 158-160 unused; used to be SIOC*IFARP ioctls */
	/* 158 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 159 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 160 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

	/* 161 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

	/* These are handled in ip_sioctl_copyin_setup itself */
	/* 162 */ { SIOCGIP6ADDRPOLICY, 0, IPI_NULL_BCONT,
			MISC_CMD, NULL, NULL },
	/* 163 */ { SIOCSIP6ADDRPOLICY, 0, IPI_PRIV | IPI_NULL_BCONT,
			MISC_CMD, NULL, NULL },
	/* 164 */ { SIOCGDSTINFO, 0, IPI_GET_CMD, MISC_CMD, NULL, NULL },

	/* 165 */ { SIOCGLIFCONF, 0, IPI_GET_CMD, MISC_CMD,
			ip_sioctl_get_lifconf, NULL },

	/* 166 */ { SIOCSXARP, sizeof (struct xarpreq), IPI_PRIV | IPI_WR,
			XARP_CMD, ip_sioctl_arp, NULL },
	/* 167 */ { SIOCGXARP, sizeof (struct xarpreq), IPI_GET_CMD,
			XARP_CMD, ip_sioctl_arp, NULL },
	/* 168 */ { SIOCDXARP, sizeof (struct xarpreq), IPI_PRIV | IPI_WR,
			XARP_CMD, ip_sioctl_arp, NULL },

	/* SIOCPOPSOCKFS is not handled by IP */
	/* 169 */ { IPI_DONTCARE /* SIOCPOPSOCKFS */, 0, 0, 0, NULL, NULL },

	/* 170 */ { SIOCGLIFZONE, sizeof (struct lifreq),
			IPI_GET_CMD, LIF_CMD, ip_sioctl_get_lifzone, NULL },
	/* 171 */ { SIOCSLIFZONE, sizeof (struct lifreq),
			IPI_PRIV | IPI_WR, LIF_CMD, ip_sioctl_slifzone,
			ip_sioctl_slifzone_restart },
	/* 172-174 are SCTP ioctls and not handled by IP */
	/* 172 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 173 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 174 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* 175 */ { SIOCGLIFUSESRC, sizeof (struct lifreq),
			IPI_GET_CMD, LIF_CMD,
			ip_sioctl_get_lifusesrc, 0 },
	/* 176 */ { SIOCSLIFUSESRC, sizeof (struct lifreq),
			IPI_PRIV | IPI_WR,
			LIF_CMD, ip_sioctl_slifusesrc,
			NULL },
	/* 177 */ { SIOCGLIFSRCOF, 0, IPI_GET_CMD, MISC_CMD,
			ip_sioctl_get_lifsrcof, NULL },
	/* 178 */ { SIOCGMSFILTER, sizeof (struct group_filter), IPI_GET_CMD,
			MSFILT_CMD, ip_sioctl_msfilter, NULL },
	/* 179 */ { SIOCSMSFILTER, sizeof (struct group_filter), 0,
			MSFILT_CMD, ip_sioctl_msfilter, NULL },
	/* 180 */ { SIOCGIPMSFILTER, sizeof (struct ip_msfilter), IPI_GET_CMD,
			MSFILT_CMD, ip_sioctl_msfilter, NULL },
	/* 181 */ { SIOCSIPMSFILTER, sizeof (struct ip_msfilter), 0,
			MSFILT_CMD, ip_sioctl_msfilter, NULL },
	/* 182 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
	/* SIOCSENABLESDP is handled by SDP */
	/* 183 */ { IPI_DONTCARE /* SIOCSENABLESDP */, 0, 0, 0, NULL, NULL },
	/* 184 */ { IPI_DONTCARE /* SIOCSQPTR */, 0, 0, 0, NULL, NULL },
	/* 185 */ { IPI_DONTCARE /* SIOCGIFHWADDR */, 0, 0, 0, NULL, NULL },
	/* 186 */ { IPI_DONTCARE /* SIOCGSTAMP */, 0, 0, 0, NULL, NULL },
	/* 187 */ { SIOCILB, 0, IPI_PRIV | IPI_GET_CMD, MISC_CMD,
			ip_sioctl_ilb_cmd, NULL },
};

int ip_ndx_ioctl_count = sizeof (ip_ndx_ioctl_table) / sizeof (ip_ioctl_cmd_t);

ip_ioctl_cmd_t ip_misc_ioctl_table[] = {
	{ I_LINK,	0, IPI_PRIV | IPI_WR, 0, NULL, NULL },
	{ I_UNLINK,	0, IPI_PRIV | IPI_WR, 0, NULL, NULL },
	{ I_PLINK,	0, IPI_PRIV | IPI_WR, 0, NULL, NULL },
	{ I_PUNLINK,	0, IPI_PRIV | IPI_WR, 0, NULL, NULL },
	{ ND_GET,	0, 0, 0, NULL, NULL },
	{ ND_SET,	0, IPI_PRIV | IPI_WR, 0, NULL, NULL },
	{ IP_IOCTL,	0, 0, 0, NULL, NULL },
	{ SIOCGETVIFCNT, sizeof (struct sioc_vif_req), IPI_GET_CMD,
		MISC_CMD, mrt_ioctl},
	{ SIOCGETSGCNT,	sizeof (struct sioc_sg_req), IPI_GET_CMD,
		MISC_CMD, mrt_ioctl},
	{ SIOCGETLSGCNT, sizeof (struct sioc_lsg_req), IPI_GET_CMD,
		MISC_CMD, mrt_ioctl}
};

int ip_misc_ioctl_count =
    sizeof (ip_misc_ioctl_table) / sizeof (ip_ioctl_cmd_t);

int	conn_drain_nthreads;		/* Number of drainers reqd. */
					/* Settable in /etc/system */
/* Defined in ip_ire.c */
extern uint32_t ip_ire_max_bucket_cnt, ip6_ire_max_bucket_cnt;
extern uint32_t ip_ire_min_bucket_cnt, ip6_ire_min_bucket_cnt;
extern uint32_t ip_ire_mem_ratio, ip_ire_cpu_ratio;

static nv_t	ire_nv_arr[] = {
	{ IRE_BROADCAST, "BROADCAST" },
	{ IRE_LOCAL, "LOCAL" },
	{ IRE_LOOPBACK, "LOOPBACK" },
	{ IRE_DEFAULT, "DEFAULT" },
	{ IRE_PREFIX, "PREFIX" },
	{ IRE_IF_NORESOLVER, "IF_NORESOL" },
	{ IRE_IF_RESOLVER, "IF_RESOLV" },
	{ IRE_IF_CLONE, "IF_CLONE" },
	{ IRE_HOST, "HOST" },
	{ IRE_MULTICAST, "MULTICAST" },
	{ IRE_NOROUTE, "NOROUTE" },
	{ 0 }
};

nv_t	*ire_nv_tbl = ire_nv_arr;

/* Simple ICMP IP Header Template */
static ipha_t icmp_ipha = {
	IP_SIMPLE_HDR_VERSION, 0, 0, 0, 0, 0, IPPROTO_ICMP
};

struct module_info ip_mod_info = {
	IP_MOD_ID, IP_MOD_NAME, IP_MOD_MINPSZ, IP_MOD_MAXPSZ, IP_MOD_HIWAT,
	IP_MOD_LOWAT
};

/*
 * Duplicate static symbols within a module confuses mdb; so we avoid the
 * problem by making the symbols here distinct from those in udp.c.
 */

/*
 * Entry points for IP as a device and as a module.
 * We have separate open functions for the /dev/ip and /dev/ip6 devices.
 */
static struct qinit iprinitv4 = {
	(pfi_t)ip_rput, NULL, ip_openv4, ip_close, NULL,
	&ip_mod_info
};

struct qinit iprinitv6 = {
	(pfi_t)ip_rput_v6, NULL, ip_openv6, ip_close, NULL,
	&ip_mod_info
};

static struct qinit ipwinit = {
	(pfi_t)ip_wput_nondata, (pfi_t)ip_wsrv, NULL, NULL, NULL,
	&ip_mod_info
};

static struct qinit iplrinit = {
	(pfi_t)ip_lrput, NULL, ip_openv4, ip_close, NULL,
	&ip_mod_info
};

static struct qinit iplwinit = {
	(pfi_t)ip_lwput, NULL, NULL, NULL, NULL,
	&ip_mod_info
};

/* For AF_INET aka /dev/ip */
struct streamtab ipinfov4 = {
	&iprinitv4, &ipwinit, &iplrinit, &iplwinit
};

/* For AF_INET6 aka /dev/ip6 */
struct streamtab ipinfov6 = {
	&iprinitv6, &ipwinit, &iplrinit, &iplwinit
};

#ifdef	DEBUG
boolean_t skip_sctp_cksum = B_FALSE;
#endif

/*
 * Generate an ICMP fragmentation needed message.
 * When called from ip_output side a minimal ip_recv_attr_t needs to be
 * constructed by the caller.
 */
void
icmp_frag_needed(mblk_t *mp, int mtu, ip_recv_attr_t *ira)
{
	icmph_t	icmph;
	ip_stack_t	*ipst = ira->ira_ill->ill_ipst;

	mp = icmp_pkt_err_ok(mp, ira);
	if (mp == NULL)
		return;

	bzero(&icmph, sizeof (icmph_t));
	icmph.icmph_type = ICMP_DEST_UNREACHABLE;
	icmph.icmph_code = ICMP_FRAGMENTATION_NEEDED;
	icmph.icmph_du_mtu = htons((uint16_t)mtu);
	BUMP_MIB(&ipst->ips_icmp_mib, icmpOutFragNeeded);
	BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDestUnreachs);

	icmp_pkt(mp, &icmph, sizeof (icmph_t), ira);
}

/*
 * icmp_inbound_v4 deals with ICMP messages that are handled by IP.
 * If the ICMP message is consumed by IP, i.e., it should not be delivered
 * to any IPPROTO_ICMP raw sockets, then it returns NULL.
 * Likewise, if the ICMP error is misformed (too short, etc), then it
 * returns NULL. The caller uses this to determine whether or not to send
 * to raw sockets.
 *
 * All error messages are passed to the matching transport stream.
 *
 * The following cases are handled by icmp_inbound:
 * 1) It needs to send a reply back and possibly delivering it
 *    to the "interested" upper clients.
 * 2) Return the mblk so that the caller can pass it to the RAW socket clients.
 * 3) It needs to change some values in IP only.
 * 4) It needs to change some values in IP and upper layers e.g TCP
 *    by delivering an error to the upper layers.
 *
 * We handle the above three cases in the context of IPsec in the
 * following way :
 *
 * 1) Send the reply back in the same way as the request came in.
 *    If it came in encrypted, it goes out encrypted. If it came in
 *    clear, it goes out in clear. Thus, this will prevent chosen
 *    plain text attack.
 * 2) The client may or may not expect things to come in secure.
 *    If it comes in secure, the policy constraints are checked
 *    before delivering it to the upper layers. If it comes in
 *    clear, ipsec_inbound_accept_clear will decide whether to
 *    accept this in clear or not. In both the cases, if the returned
 *    message (IP header + 8 bytes) that caused the icmp message has
 *    AH/ESP headers, it is sent up to AH/ESP for validation before
 *    sending up. If there are only 8 bytes of returned message, then
 *    upper client will not be notified.
 * 3) Check with global policy to see whether it matches the constaints.
 *    But this will be done only if icmp_accept_messages_in_clear is
 *    zero.
 * 4) If we need to change both in IP and ULP, then the decision taken
 *    while affecting the values in IP and while delivering up to TCP
 *    should be the same.
 *
 * 	There are two cases.
 *
 * 	a) If we reject data at the IP layer (ipsec_check_global_policy()
 *	   failed), we will not deliver it to the ULP, even though they
 *	   are *willing* to accept in *clear*. This is fine as our global
 *	   disposition to icmp messages asks us reject the datagram.
 *
 *	b) If we accept data at the IP layer (ipsec_check_global_policy()
 *	   succeeded or icmp_accept_messages_in_clear is 1), and not able
 *	   to deliver it to ULP (policy failed), it can lead to
 *	   consistency problems. The cases known at this time are
 *	   ICMP_DESTINATION_UNREACHABLE  messages with following code
 *	   values :
 *
 *	   - ICMP_FRAGMENTATION_NEEDED : IP adapts to the new value
 *	     and Upper layer rejects. Then the communication will
 *	     come to a stop. This is solved by making similar decisions
 *	     at both levels. Currently, when we are unable to deliver
 *	     to the Upper Layer (due to policy failures) while IP has
 *	     adjusted dce_pmtu, the next outbound datagram would
 *	     generate a local ICMP_FRAGMENTATION_NEEDED message - which
 *	     will be with the right level of protection. Thus the right
 *	     value will be communicated even if we are not able to
 *	     communicate when we get from the wire initially. But this
 *	     assumes there would be at least one outbound datagram after
 *	     IP has adjusted its dce_pmtu value. To make things
 *	     simpler, we accept in clear after the validation of
 *	     AH/ESP headers.
 *
 *	   - Other ICMP ERRORS : We may not be able to deliver it to the
 *	     upper layer depending on the level of protection the upper
 *	     layer expects and the disposition in ipsec_inbound_accept_clear().
 *	     ipsec_inbound_accept_clear() decides whether a given ICMP error
 *	     should be accepted in clear when the Upper layer expects secure.
 *	     Thus the communication may get aborted by some bad ICMP
 *	     packets.
 */
mblk_t *
icmp_inbound_v4(mblk_t *mp, ip_recv_attr_t *ira)
{
	icmph_t		*icmph;
	ipha_t		*ipha;		/* Outer header */
	int		ip_hdr_length;	/* Outer header length */
	boolean_t	interested;
	ipif_t		*ipif;
	uint32_t	ts;
	uint32_t	*tsp;
	timestruc_t	now;
	ill_t		*ill = ira->ira_ill;
	ip_stack_t	*ipst = ill->ill_ipst;
	zoneid_t	zoneid = ira->ira_zoneid;
	int		len_needed;
	mblk_t		*mp_ret = NULL;

	ipha = (ipha_t *)mp->b_rptr;

	BUMP_MIB(&ipst->ips_icmp_mib, icmpInMsgs);

	ip_hdr_length = ira->ira_ip_hdr_length;
	if ((mp->b_wptr - mp->b_rptr) < (ip_hdr_length + ICMPH_SIZE)) {
		if (ira->ira_pktlen < (ip_hdr_length + ICMPH_SIZE)) {
			BUMP_MIB(ill->ill_ip_mib, ipIfStatsInTruncatedPkts);
			ip_drop_input("ipIfStatsInTruncatedPkts", mp, ill);
			freemsg(mp);
			return (NULL);
		}
		/* Last chance to get real. */
		ipha = ip_pullup(mp, ip_hdr_length + ICMPH_SIZE, ira);
		if (ipha == NULL) {
			BUMP_MIB(&ipst->ips_icmp_mib, icmpInErrors);
			freemsg(mp);
			return (NULL);
		}
	}

	/* The IP header will always be a multiple of four bytes */
	icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
	ip2dbg(("icmp_inbound_v4: type %d code %d\n", icmph->icmph_type,
	    icmph->icmph_code));

	/*
	 * We will set "interested" to "true" if we should pass a copy to
	 * the transport or if we handle the packet locally.
	 */
	interested = B_FALSE;
	switch (icmph->icmph_type) {
	case ICMP_ECHO_REPLY:
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInEchoReps);
		break;
	case ICMP_DEST_UNREACHABLE:
		if (icmph->icmph_code == ICMP_FRAGMENTATION_NEEDED)
			BUMP_MIB(&ipst->ips_icmp_mib, icmpInFragNeeded);
		interested = B_TRUE;	/* Pass up to transport */
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInDestUnreachs);
		break;
	case ICMP_SOURCE_QUENCH:
		interested = B_TRUE;	/* Pass up to transport */
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInSrcQuenchs);
		break;
	case ICMP_REDIRECT:
		if (!ipst->ips_ip_ignore_redirect)
			interested = B_TRUE;
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInRedirects);
		break;
	case ICMP_ECHO_REQUEST:
		/*
		 * Whether to respond to echo requests that come in as IP
		 * broadcasts or as IP multicast is subject to debate
		 * (what isn't?).  We aim to please, you pick it.
		 * Default is do it.
		 */
		if (ira->ira_flags & IRAF_MULTICAST) {
			/* multicast: respond based on tunable */
			interested = ipst->ips_ip_g_resp_to_echo_mcast;
		} else if (ira->ira_flags & IRAF_BROADCAST) {
			/* broadcast: respond based on tunable */
			interested = ipst->ips_ip_g_resp_to_echo_bcast;
		} else {
			/* unicast: always respond */
			interested = B_TRUE;
		}
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInEchos);
		if (!interested) {
			/* We never pass these to RAW sockets */
			freemsg(mp);
			return (NULL);
		}

		/* Check db_ref to make sure we can modify the packet. */
		if (mp->b_datap->db_ref > 1) {
			mblk_t	*mp1;

			mp1 = copymsg(mp);
			freemsg(mp);
			if (!mp1) {
				BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDrops);
				return (NULL);
			}
			mp = mp1;
			ipha = (ipha_t *)mp->b_rptr;
			icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
		}
		icmph->icmph_type = ICMP_ECHO_REPLY;
		BUMP_MIB(&ipst->ips_icmp_mib, icmpOutEchoReps);
		icmp_send_reply_v4(mp, ipha, icmph, ira);
		return (NULL);

	case ICMP_ROUTER_ADVERTISEMENT:
	case ICMP_ROUTER_SOLICITATION:
		break;
	case ICMP_TIME_EXCEEDED:
		interested = B_TRUE;	/* Pass up to transport */
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInTimeExcds);
		break;
	case ICMP_PARAM_PROBLEM:
		interested = B_TRUE;	/* Pass up to transport */
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInParmProbs);
		break;
	case ICMP_TIME_STAMP_REQUEST:
		/* Response to Time Stamp Requests is local policy. */
		if (ipst->ips_ip_g_resp_to_timestamp) {
			if (ira->ira_flags & IRAF_MULTIBROADCAST)
				interested =
				    ipst->ips_ip_g_resp_to_timestamp_bcast;
			else
				interested = B_TRUE;
		}
		if (!interested) {
			/* We never pass these to RAW sockets */
			freemsg(mp);
			return (NULL);
		}

		/* Make sure we have enough of the packet */
		len_needed = ip_hdr_length + ICMPH_SIZE +
		    3 * sizeof (uint32_t);

		if (mp->b_wptr - mp->b_rptr < len_needed) {
			ipha = ip_pullup(mp, len_needed, ira);
			if (ipha == NULL) {
				BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
				ip_drop_input("ipIfStatsInDiscards - ip_pullup",
				    mp, ill);
				freemsg(mp);
				return (NULL);
			}
			/* Refresh following the pullup. */
			icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
		}
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInTimestamps);
		/* Check db_ref to make sure we can modify the packet. */
		if (mp->b_datap->db_ref > 1) {
			mblk_t	*mp1;

			mp1 = copymsg(mp);
			freemsg(mp);
			if (!mp1) {
				BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDrops);
				return (NULL);
			}
			mp = mp1;
			ipha = (ipha_t *)mp->b_rptr;
			icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
		}
		icmph->icmph_type = ICMP_TIME_STAMP_REPLY;
		tsp = (uint32_t *)&icmph[1];
		tsp++;		/* Skip past 'originate time' */
		/* Compute # of milliseconds since midnight */
		gethrestime(&now);
		ts = (now.tv_sec % (24 * 60 * 60)) * 1000 +
		    now.tv_nsec / (NANOSEC / MILLISEC);
		*tsp++ = htonl(ts);	/* Lay in 'receive time' */
		*tsp++ = htonl(ts);	/* Lay in 'send time' */
		BUMP_MIB(&ipst->ips_icmp_mib, icmpOutTimestampReps);
		icmp_send_reply_v4(mp, ipha, icmph, ira);
		return (NULL);

	case ICMP_TIME_STAMP_REPLY:
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInTimestampReps);
		break;
	case ICMP_INFO_REQUEST:
		/* Per RFC 1122 3.2.2.7, ignore this. */
	case ICMP_INFO_REPLY:
		break;
	case ICMP_ADDRESS_MASK_REQUEST:
		if (ira->ira_flags & IRAF_MULTIBROADCAST) {
			interested =
			    ipst->ips_ip_respond_to_address_mask_broadcast;
		} else {
			interested = B_TRUE;
		}
		if (!interested) {
			/* We never pass these to RAW sockets */
			freemsg(mp);
			return (NULL);
		}
		len_needed = ip_hdr_length + ICMPH_SIZE + IP_ADDR_LEN;
		if (mp->b_wptr - mp->b_rptr < len_needed) {
			ipha = ip_pullup(mp, len_needed, ira);
			if (ipha == NULL) {
				BUMP_MIB(ill->ill_ip_mib,
				    ipIfStatsInTruncatedPkts);
				ip_drop_input("ipIfStatsInTruncatedPkts", mp,
				    ill);
				freemsg(mp);
				return (NULL);
			}
			/* Refresh following the pullup. */
			icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
		}
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInAddrMasks);
		/* Check db_ref to make sure we can modify the packet. */
		if (mp->b_datap->db_ref > 1) {
			mblk_t	*mp1;

			mp1 = copymsg(mp);
			freemsg(mp);
			if (!mp1) {
				BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDrops);
				return (NULL);
			}
			mp = mp1;
			ipha = (ipha_t *)mp->b_rptr;
			icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
		}
		/*
		 * Need the ipif with the mask be the same as the source
		 * address of the mask reply. For unicast we have a specific
		 * ipif. For multicast/broadcast we only handle onlink
		 * senders, and use the source address to pick an ipif.
		 */
		ipif = ipif_lookup_addr(ipha->ipha_dst, ill, zoneid, ipst);
		if (ipif == NULL) {
			/* Broadcast or multicast */
			ipif = ipif_lookup_remote(ill, ipha->ipha_src, zoneid);
			if (ipif == NULL) {
				freemsg(mp);
				return (NULL);
			}
		}
		icmph->icmph_type = ICMP_ADDRESS_MASK_REPLY;
		bcopy(&ipif->ipif_net_mask, &icmph[1], IP_ADDR_LEN);
		ipif_refrele(ipif);
		BUMP_MIB(&ipst->ips_icmp_mib, icmpOutAddrMaskReps);
		icmp_send_reply_v4(mp, ipha, icmph, ira);
		return (NULL);

	case ICMP_ADDRESS_MASK_REPLY:
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInAddrMaskReps);
		break;
	default:
		interested = B_TRUE;	/* Pass up to transport */
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInUnknowns);
		break;
	}
	/*
	 * See if there is an ICMP client to avoid an extra copymsg/freemsg
	 * if there isn't one.
	 */
	if (ipst->ips_ipcl_proto_fanout_v4[IPPROTO_ICMP].connf_head != NULL) {
		/* If there is an ICMP client and we want one too, copy it. */

		if (!interested) {
			/* Caller will deliver to RAW sockets */
			return (mp);
		}
		mp_ret = copymsg(mp);
		if (mp_ret == NULL) {
			BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
			ip_drop_input("ipIfStatsInDiscards - copymsg", mp, ill);
		}
	} else if (!interested) {
		/* Neither we nor raw sockets are interested. Drop packet now */
		freemsg(mp);
		return (NULL);
	}

	/*
	 * ICMP error or redirect packet. Make sure we have enough of
	 * the header and that db_ref == 1 since we might end up modifying
	 * the packet.
	 */
	if (mp->b_cont != NULL) {
		if (ip_pullup(mp, -1, ira) == NULL) {
			BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
			ip_drop_input("ipIfStatsInDiscards - ip_pullup",
			    mp, ill);
			freemsg(mp);
			return (mp_ret);
		}
	}

	if (mp->b_datap->db_ref > 1) {
		mblk_t	*mp1;

		mp1 = copymsg(mp);
		if (mp1 == NULL) {
			BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
			ip_drop_input("ipIfStatsInDiscards - copymsg", mp, ill);
			freemsg(mp);
			return (mp_ret);
		}
		freemsg(mp);
		mp = mp1;
	}

	/*
	 * In case mp has changed, verify the message before any further
	 * processes.
	 */
	ipha = (ipha_t *)mp->b_rptr;
	icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
	if (!icmp_inbound_verify_v4(mp, icmph, ira)) {
		freemsg(mp);
		return (mp_ret);
	}

	switch (icmph->icmph_type) {
	case ICMP_REDIRECT:
		icmp_redirect_v4(mp, ipha, icmph, ira);
		break;
	case ICMP_DEST_UNREACHABLE:
		if (icmph->icmph_code == ICMP_FRAGMENTATION_NEEDED) {
			/* Update DCE and adjust MTU is icmp header if needed */
			icmp_inbound_too_big_v4(icmph, ira);
		}
		/* FALLTHRU */
	default:
		icmp_inbound_error_fanout_v4(mp, icmph, ira);
		break;
	}
	return (mp_ret);
}

/*
 * Send an ICMP echo, timestamp or address mask reply.
 * The caller has already updated the payload part of the packet.
 * We handle the ICMP checksum, IP source address selection and feed
 * the packet into ip_output_simple.
 */
static void
icmp_send_reply_v4(mblk_t *mp, ipha_t *ipha, icmph_t *icmph,
    ip_recv_attr_t *ira)
{
	uint_t		ip_hdr_length = ira->ira_ip_hdr_length;
	ill_t		*ill = ira->ira_ill;
	ip_stack_t	*ipst = ill->ill_ipst;
	ip_xmit_attr_t	ixas;

	/* Send out an ICMP packet */
	icmph->icmph_checksum = 0;
	icmph->icmph_checksum = IP_CSUM(mp, ip_hdr_length, 0);
	/* Reset time to live. */
	ipha->ipha_ttl = ipst->ips_ip_def_ttl;
	{
		/* Swap source and destination addresses */
		ipaddr_t tmp;

		tmp = ipha->ipha_src;
		ipha->ipha_src = ipha->ipha_dst;
		ipha->ipha_dst = tmp;
	}
	ipha->ipha_ident = 0;
	if (!IS_SIMPLE_IPH(ipha))
		icmp_options_update(ipha);

	bzero(&ixas, sizeof (ixas));
	ixas.ixa_flags = IXAF_BASIC_SIMPLE_V4;
	ixas.ixa_zoneid = ira->ira_zoneid;
	ixas.ixa_cred = kcred;
	ixas.ixa_cpid = NOPID;
	ixas.ixa_tsl = ira->ira_tsl;	/* Behave as a multi-level responder */
	ixas.ixa_ifindex = 0;
	ixas.ixa_ipst = ipst;
	ixas.ixa_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;

	if (!(ira->ira_flags & IRAF_IPSEC_SECURE)) {
		/*
		 * This packet should go out the same way as it
		 * came in i.e in clear, independent of the IPsec policy
		 * for transmitting packets.
		 */
		ixas.ixa_flags |= IXAF_NO_IPSEC;
	} else {
		if (!ipsec_in_to_out(ira, &ixas, mp, ipha, NULL)) {
			BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
			/* Note: mp already consumed and ip_drop_packet done */
			return;
		}
	}
	if (ira->ira_flags & IRAF_MULTIBROADCAST) {
		/*
		 * Not one or our addresses (IRE_LOCALs), thus we let
		 * ip_output_simple pick the source.
		 */
		ipha->ipha_src = INADDR_ANY;
		ixas.ixa_flags |= IXAF_SET_SOURCE;
	}
	/* Should we send with DF and use dce_pmtu? */
	if (ipst->ips_ipv4_icmp_return_pmtu) {
		ixas.ixa_flags |= IXAF_PMTU_DISCOVERY;
		ipha->ipha_fragment_offset_and_flags |= IPH_DF_HTONS;
	}

	BUMP_MIB(&ipst->ips_icmp_mib, icmpOutMsgs);

	(void) ip_output_simple(mp, &ixas);
	ixa_cleanup(&ixas);
}

/*
 * Verify the ICMP messages for either for ICMP error or redirect packet.
 * The caller should have fully pulled up the message. If it's a redirect
 * packet, only basic checks on IP header will be done; otherwise, verify
 * the packet by looking at the included ULP header.
 *
 * Called before icmp_inbound_error_fanout_v4 is called.
 */
static boolean_t
icmp_inbound_verify_v4(mblk_t *mp, icmph_t *icmph, ip_recv_attr_t *ira)
{
	ill_t		*ill = ira->ira_ill;
	int		hdr_length;
	ip_stack_t	*ipst = ira->ira_ill->ill_ipst;
	conn_t		*connp;
	ipha_t		*ipha;	/* Inner IP header */

	ipha = (ipha_t *)&icmph[1];
	if ((uchar_t *)ipha + IP_SIMPLE_HDR_LENGTH > mp->b_wptr)
		goto truncated;

	hdr_length = IPH_HDR_LENGTH(ipha);

	if ((IPH_HDR_VERSION(ipha) != IPV4_VERSION))
		goto discard_pkt;

	if (hdr_length < sizeof (ipha_t))
		goto truncated;

	if ((uchar_t *)ipha + hdr_length > mp->b_wptr)
		goto truncated;

	/*
	 * Stop here for ICMP_REDIRECT.
	 */
	if (icmph->icmph_type == ICMP_REDIRECT)
		return (B_TRUE);

	/*
	 * ICMP errors only.
	 */
	switch (ipha->ipha_protocol) {
	case IPPROTO_UDP:
		/*
		 * Verify we have at least ICMP_MIN_TP_HDR_LEN bytes of
		 * transport header.
		 */
		if ((uchar_t *)ipha + hdr_length + ICMP_MIN_TP_HDR_LEN >
		    mp->b_wptr)
			goto truncated;
		break;
	case IPPROTO_TCP: {
		tcpha_t		*tcpha;

		/*
		 * Verify we have at least ICMP_MIN_TP_HDR_LEN bytes of
		 * transport header.
		 */
		if ((uchar_t *)ipha + hdr_length + ICMP_MIN_TP_HDR_LEN >
		    mp->b_wptr)
			goto truncated;

		tcpha = (tcpha_t *)((uchar_t *)ipha + hdr_length);
		connp = ipcl_tcp_lookup_reversed_ipv4(ipha, tcpha, TCPS_LISTEN,
		    ipst);
		if (connp == NULL)
			goto discard_pkt;

		if ((connp->conn_verifyicmp != NULL) &&
		    !connp->conn_verifyicmp(connp, tcpha, icmph, NULL, ira)) {
			CONN_DEC_REF(connp);
			goto discard_pkt;
		}
		CONN_DEC_REF(connp);
		break;
	}
	case IPPROTO_SCTP:
		/*
		 * Verify we have at least ICMP_MIN_TP_HDR_LEN bytes of
		 * transport header.
		 */
		if ((uchar_t *)ipha + hdr_length + ICMP_MIN_TP_HDR_LEN >
		    mp->b_wptr)
			goto truncated;
		break;
	case IPPROTO_ESP:
	case IPPROTO_AH:
		break;
	case IPPROTO_ENCAP:
		if ((uchar_t *)ipha + hdr_length + sizeof (ipha_t) >
		    mp->b_wptr)
			goto truncated;
		break;
	default:
		break;
	}

	return (B_TRUE);

discard_pkt:
	/* Bogus ICMP error. */
	BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
	return (B_FALSE);

truncated:
	/* We pulled up everthing already. Must be truncated */
	BUMP_MIB(ill->ill_ip_mib, ipIfStatsInTruncatedPkts);
	ip_drop_input("ipIfStatsInTruncatedPkts", mp, ill);
	return (B_FALSE);
}

/* Table from RFC 1191 */
static int icmp_frag_size_table[] =
{ 32000, 17914, 8166, 4352, 2002, 1496, 1006, 508, 296, 68 };

/*
 * Process received ICMP Packet too big.
 * Just handles the DCE create/update, including using the above table of
 * PMTU guesses. The caller is responsible for validating the packet before
 * passing it in and also to fanout the ICMP error to any matching transport
 * conns. Assumes the message has been fully pulled up and verified.
 *
 * Before getting here, the caller has called icmp_inbound_verify_v4()
 * that should have verified with ULP to prevent undoing the changes we're
 * going to make to DCE. For example, TCP might have verified that the packet
 * which generated error is in the send window.
 *
 * In some cases modified this MTU in the ICMP header packet; the caller
 * should pass to the matching ULP after this returns.
 */
static void
icmp_inbound_too_big_v4(icmph_t *icmph, ip_recv_attr_t *ira)
{
	dce_t		*dce;
	int		old_mtu;
	int		mtu, orig_mtu;
	ipaddr_t	dst;
	boolean_t	disable_pmtud;
	ill_t		*ill = ira->ira_ill;
	ip_stack_t	*ipst = ill->ill_ipst;
	uint_t		hdr_length;
	ipha_t		*ipha;

	/* Caller already pulled up everything. */
	ipha = (ipha_t *)&icmph[1];
	ASSERT(icmph->icmph_type == ICMP_DEST_UNREACHABLE &&
	    icmph->icmph_code == ICMP_FRAGMENTATION_NEEDED);
	ASSERT(ill != NULL);

	hdr_length = IPH_HDR_LENGTH(ipha);

	/*
	 * We handle path MTU for source routed packets since the DCE
	 * is looked up using the final destination.
	 */
	dst = ip_get_dst(ipha);

	dce = dce_lookup_and_add_v4(dst, ipst);
	if (dce == NULL) {
		/* Couldn't add a unique one - ENOMEM */
		ip1dbg(("icmp_inbound_too_big_v4: no dce for 0x%x\n",
		    ntohl(dst)));
		return;
	}

	/* Check for MTU discovery advice as described in RFC 1191 */
	mtu = ntohs(icmph->icmph_du_mtu);
	orig_mtu = mtu;
	disable_pmtud = B_FALSE;

	mutex_enter(&dce->dce_lock);
	if (dce->dce_flags & DCEF_PMTU)
		old_mtu = dce->dce_pmtu;
	else
		old_mtu = ill->ill_mtu;

	if (icmph->icmph_du_zero != 0 || mtu < ipst->ips_ip_pmtu_min) {
		uint32_t length;
		int	i;

		/*
		 * Use the table from RFC 1191 to figure out
		 * the next "plateau" based on the length in
		 * the original IP packet.
		 */
		length = ntohs(ipha->ipha_length);
		DTRACE_PROBE2(ip4__pmtu__guess, dce_t *, dce,
		    uint32_t, length);
		if (old_mtu <= length &&
		    old_mtu >= length - hdr_length) {
			/*
			 * Handle broken BSD 4.2 systems that
			 * return the wrong ipha_length in ICMP
			 * errors.
			 */
			ip1dbg(("Wrong mtu: sent %d, dce %d\n",
			    length, old_mtu));
			length -= hdr_length;
		}
		for (i = 0; i < A_CNT(icmp_frag_size_table); i++) {
			if (length > icmp_frag_size_table[i])
				break;
		}
		if (i == A_CNT(icmp_frag_size_table)) {
			/* Smaller than IP_MIN_MTU! */
			ip1dbg(("Too big for packet size %d\n",
			    length));
			disable_pmtud = B_TRUE;
			mtu = ipst->ips_ip_pmtu_min;
		} else {
			mtu = icmp_frag_size_table[i];
			ip1dbg(("Calculated mtu %d, packet size %d, "
			    "before %d\n", mtu, length, old_mtu));
			if (mtu < ipst->ips_ip_pmtu_min) {
				mtu = ipst->ips_ip_pmtu_min;
				disable_pmtud = B_TRUE;
			}
		}
	}
	if (disable_pmtud)
		dce->dce_flags |= DCEF_TOO_SMALL_PMTU;
	else
		dce->dce_flags &= ~DCEF_TOO_SMALL_PMTU;

	dce->dce_pmtu = MIN(old_mtu, mtu);
	/* Prepare to send the new max frag size for the ULP. */
	icmph->icmph_du_zero = 0;
	icmph->icmph_du_mtu =  htons((uint16_t)dce->dce_pmtu);
	DTRACE_PROBE4(ip4__pmtu__change, icmph_t *, icmph, dce_t *,
	    dce, int, orig_mtu, int, mtu);

	/* We now have a PMTU for sure */
	dce->dce_flags |= DCEF_PMTU;
	dce->dce_last_change_time = TICK_TO_SEC(ddi_get_lbolt64());
	mutex_exit(&dce->dce_lock);
	/*
	 * After dropping the lock the new value is visible to everyone.
	 * Then we bump the generation number so any cached values reinspect
	 * the dce_t.
	 */
	dce_increment_generation(dce);
	dce_refrele(dce);
}

/*
 * If the packet in error is Self-Encapsulated, icmp_inbound_error_fanout_v4
 * calls this function.
 */
static mblk_t *
icmp_inbound_self_encap_error_v4(mblk_t *mp, ipha_t *ipha, ipha_t *in_ipha)
{
	int length;

	ASSERT(mp->b_datap->db_type == M_DATA);

	/* icmp_inbound_v4 has already pulled up the whole error packet */
	ASSERT(mp->b_cont == NULL);

	/*
	 * The length that we want to overlay is the inner header
	 * and what follows it.
	 */
	length = msgdsize(mp) - ((uchar_t *)in_ipha - mp->b_rptr);

	/*
	 * Overlay the inner header and whatever follows it over the
	 * outer header.
	 */
	bcopy((uchar_t *)in_ipha, (uchar_t *)ipha, length);

	/* Adjust for what we removed */
	mp->b_wptr -= (uchar_t *)in_ipha - (uchar_t *)ipha;
	return (mp);
}

/*
 * Try to pass the ICMP message upstream in case the ULP cares.
 *
 * If the packet that caused the ICMP error is secure, we send
 * it to AH/ESP to make sure that the attached packet has a
 * valid association. ipha in the code below points to the
 * IP header of the packet that caused the error.
 *
 * For IPsec cases, we let the next-layer-up (which has access to
 * cached policy on the conn_t, or can query the SPD directly)
 * subtract out any IPsec overhead if they must.  We therefore make no
 * adjustments here for IPsec overhead.
 *
 * IFN could have been generated locally or by some router.
 *
 * LOCAL : ire_send_wire (before calling ipsec_out_process) can call
 * icmp_frag_needed/icmp_pkt2big_v6 to generated a local IFN.
 *	    This happens because IP adjusted its value of MTU on an
 *	    earlier IFN message and could not tell the upper layer,
 *	    the new adjusted value of MTU e.g. Packet was encrypted
 *	    or there was not enough information to fanout to upper
 *	    layers. Thus on the next outbound datagram, ire_send_wire
 *	    generates the IFN, where IPsec processing has *not* been
 *	    done.
 *
 *	    Note that we retain ixa_fragsize across IPsec thus once
 *	    we have picking ixa_fragsize and entered ipsec_out_process we do
 *	    no change the fragsize even if the path MTU changes before
 *	    we reach ip_output_post_ipsec.
 *
 *	    In the local case, IRAF_LOOPBACK will be set indicating
 *	    that IFN was generated locally.
 *
 * ROUTER : IFN could be secure or non-secure.
 *
 *	    * SECURE : We use the IPSEC_IN to fanout to AH/ESP if the
 *	      packet in error has AH/ESP headers to validate the AH/ESP
 *	      headers. AH/ESP will verify whether there is a valid SA or
 *	      not and send it back. We will fanout again if we have more
 *	      data in the packet.
 *
 *	      If the packet in error does not have AH/ESP, we handle it
 *	      like any other case.
 *
 *	    * NON_SECURE : If the packet in error has AH/ESP headers, we send it
 *	      up to AH/ESP for validation. AH/ESP will verify whether there is a
 *	      valid SA or not and send it back. We will fanout again if
 *	      we have more data in the packet.
 *
 *	      If the packet in error does not have AH/ESP, we handle it
 *	      like any other case.
 *
 * The caller must have called icmp_inbound_verify_v4.
 */
static void
icmp_inbound_error_fanout_v4(mblk_t *mp, icmph_t *icmph, ip_recv_attr_t *ira)
{
	uint16_t	*up;	/* Pointer to ports in ULP header */
	uint32_t	ports;	/* reversed ports for fanout */
	ipha_t		ripha;	/* With reversed addresses */
	ipha_t		*ipha;  /* Inner IP header */
	uint_t		hdr_length; /* Inner IP header length */
	tcpha_t		*tcpha;
	conn_t		*connp;
	ill_t		*ill = ira->ira_ill;
	ip_stack_t	*ipst = ill->ill_ipst;
	ipsec_stack_t	*ipss = ipst->ips_netstack->netstack_ipsec;
	ill_t		*rill = ira->ira_rill;

	/* Caller already pulled up everything. */
	ipha = (ipha_t *)&icmph[1];
	ASSERT((uchar_t *)&ipha[1] <= mp->b_wptr);
	ASSERT(mp->b_cont == NULL);

	hdr_length = IPH_HDR_LENGTH(ipha);
	ira->ira_protocol = ipha->ipha_protocol;

	/*
	 * We need a separate IP header with the source and destination
	 * addresses reversed to do fanout/classification because the ipha in
	 * the ICMP error is in the form we sent it out.
	 */
	ripha.ipha_src = ipha->ipha_dst;
	ripha.ipha_dst = ipha->ipha_src;
	ripha.ipha_protocol = ipha->ipha_protocol;
	ripha.ipha_version_and_hdr_length = ipha->ipha_version_and_hdr_length;

	ip2dbg(("icmp_inbound_error_v4: proto %d %x to %x: %d/%d\n",
	    ripha.ipha_protocol, ntohl(ipha->ipha_src),
	    ntohl(ipha->ipha_dst),
	    icmph->icmph_type, icmph->icmph_code));

	switch (ipha->ipha_protocol) {
	case IPPROTO_UDP:
		up = (uint16_t *)((uchar_t *)ipha + hdr_length);

		/* Attempt to find a client stream based on port. */
		ip2dbg(("icmp_inbound_error_v4: UDP ports %d to %d\n",
		    ntohs(up[0]), ntohs(up[1])));

		/* Note that we send error to all matches. */
		ira->ira_flags |= IRAF_ICMP_ERROR;
		ip_fanout_udp_multi_v4(mp, &ripha, up[0], up[1], ira);
		ira->ira_flags &= ~IRAF_ICMP_ERROR;
		return;

	case IPPROTO_TCP:
		/*
		 * Find a TCP client stream for this packet.
		 * Note that we do a reverse lookup since the header is
		 * in the form we sent it out.
		 */
		tcpha = (tcpha_t *)((uchar_t *)ipha + hdr_length);
		connp = ipcl_tcp_lookup_reversed_ipv4(ipha, tcpha, TCPS_LISTEN,
		    ipst);
		if (connp == NULL)
			goto discard_pkt;

		if (CONN_INBOUND_POLICY_PRESENT(connp, ipss) ||
		    (ira->ira_flags & IRAF_IPSEC_SECURE)) {
			mp = ipsec_check_inbound_policy(mp, connp,
			    ipha, NULL, ira);
			if (mp == NULL) {
				BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
				/* Note that mp is NULL */
				ip_drop_input("ipIfStatsInDiscards", mp, ill);
				CONN_DEC_REF(connp);
				return;
			}
		}

		ira->ira_flags |= IRAF_ICMP_ERROR;
		ira->ira_ill = ira->ira_rill = NULL;
		if (IPCL_IS_TCP(connp)) {
			SQUEUE_ENTER_ONE(connp->conn_sqp, mp,
			    connp->conn_recvicmp, connp, ira, SQ_FILL,
			    SQTAG_TCP_INPUT_ICMP_ERR);
		} else {
			/* Not TCP; must be SOCK_RAW, IPPROTO_TCP */
			(connp->conn_recv)(connp, mp, NULL, ira);
			CONN_DEC_REF(connp);
		}
		ira->ira_ill = ill;
		ira->ira_rill = rill;
		ira->ira_flags &= ~IRAF_ICMP_ERROR;
		return;

	case IPPROTO_SCTP:
		up = (uint16_t *)((uchar_t *)ipha + hdr_length);
		/* Find a SCTP client stream for this packet. */
		((uint16_t *)&ports)[0] = up[1];
		((uint16_t *)&ports)[1] = up[0];

		ira->ira_flags |= IRAF_ICMP_ERROR;
		ip_fanout_sctp(mp, &ripha, NULL, ports, ira);
		ira->ira_flags &= ~IRAF_ICMP_ERROR;
		return;

	case IPPROTO_ESP:
	case IPPROTO_AH:
		if (!ipsec_loaded(ipss)) {
			ip_proto_not_sup(mp, ira);
			return;
		}

		if (ipha->ipha_protocol == IPPROTO_ESP)
			mp = ipsecesp_icmp_error(mp, ira);
		else
			mp = ipsecah_icmp_error(mp, ira);
		if (mp == NULL)
			return;

		/* Just in case ipsec didn't preserve the NULL b_cont */
		if (mp->b_cont != NULL) {
			if (!pullupmsg(mp, -1))
				goto discard_pkt;
		}

		/*
		 * Note that ira_pktlen and ira_ip_hdr_length are no longer
		 * correct, but we don't use them any more here.
		 *
		 * If succesful, the mp has been modified to not include
		 * the ESP/AH header so we can fanout to the ULP's icmp
		 * error handler.
		 */
		if (mp->b_wptr - mp->b_rptr < IP_SIMPLE_HDR_LENGTH)
			goto truncated;

		/* Verify the modified message before any further processes. */
		ipha = (ipha_t *)mp->b_rptr;
		hdr_length = IPH_HDR_LENGTH(ipha);
		icmph = (icmph_t *)&mp->b_rptr[hdr_length];
		if (!icmp_inbound_verify_v4(mp, icmph, ira)) {
			freemsg(mp);
			return;
		}

		icmp_inbound_error_fanout_v4(mp, icmph, ira);
		return;

	case IPPROTO_ENCAP: {
		/* Look for self-encapsulated packets that caused an error */
		ipha_t *in_ipha;

		/*
		 * Caller has verified that length has to be
		 * at least the size of IP header.
		 */
		ASSERT(hdr_length >= sizeof (ipha_t));
		/*
		 * Check the sanity of the inner IP header like
		 * we did for the outer header.
		 */
		in_ipha = (ipha_t *)((uchar_t *)ipha + hdr_length);
		if ((IPH_HDR_VERSION(in_ipha) != IPV4_VERSION)) {
			goto discard_pkt;
		}
		if (IPH_HDR_LENGTH(in_ipha) < sizeof (ipha_t)) {
			goto discard_pkt;
		}
		/* Check for Self-encapsulated tunnels */
		if (in_ipha->ipha_src == ipha->ipha_src &&
		    in_ipha->ipha_dst == ipha->ipha_dst) {

			mp = icmp_inbound_self_encap_error_v4(mp, ipha,
			    in_ipha);
			if (mp == NULL)
				goto discard_pkt;

			/*
			 * Just in case self_encap didn't preserve the NULL
			 * b_cont
			 */
			if (mp->b_cont != NULL) {
				if (!pullupmsg(mp, -1))
					goto discard_pkt;
			}
			/*
			 * Note that ira_pktlen and ira_ip_hdr_length are no
			 * longer correct, but we don't use them any more here.
			 */
			if (mp->b_wptr - mp->b_rptr < IP_SIMPLE_HDR_LENGTH)
				goto truncated;

			/*
			 * Verify the modified message before any further
			 * processes.
			 */
			ipha = (ipha_t *)mp->b_rptr;
			hdr_length = IPH_HDR_LENGTH(ipha);
			icmph = (icmph_t *)&mp->b_rptr[hdr_length];
			if (!icmp_inbound_verify_v4(mp, icmph, ira)) {
				freemsg(mp);
				return;
			}

			/*
			 * The packet in error is self-encapsualted.
			 * And we are finding it further encapsulated
			 * which we could not have possibly generated.
			 */
			if (ipha->ipha_protocol == IPPROTO_ENCAP) {
				goto discard_pkt;
			}
			icmp_inbound_error_fanout_v4(mp, icmph, ira);
			return;
		}
		/* No self-encapsulated */
		/* FALLTHRU */
	}
	case IPPROTO_IPV6:
		if ((connp = ipcl_iptun_classify_v4(&ripha.ipha_src,
		    &ripha.ipha_dst, ipst)) != NULL) {
			ira->ira_flags |= IRAF_ICMP_ERROR;
			connp->conn_recvicmp(connp, mp, NULL, ira);
			CONN_DEC_REF(connp);
			ira->ira_flags &= ~IRAF_ICMP_ERROR;
			return;
		}
		/*
		 * No IP tunnel is interested, fallthrough and see
		 * if a raw socket will want it.
		 */
		/* FALLTHRU */
	default:
		ira->ira_flags |= IRAF_ICMP_ERROR;
		ip_fanout_proto_v4(mp, &ripha, ira);
		ira->ira_flags &= ~IRAF_ICMP_ERROR;
		return;
	}
	/* NOTREACHED */
discard_pkt:
	BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
	ip1dbg(("icmp_inbound_error_fanout_v4: drop pkt\n"));
	ip_drop_input("ipIfStatsInDiscards", mp, ill);
	freemsg(mp);
	return;

truncated:
	/* We pulled up everthing already. Must be truncated */
	BUMP_MIB(ill->ill_ip_mib, ipIfStatsInTruncatedPkts);
	ip_drop_input("ipIfStatsInTruncatedPkts", mp, ill);
	freemsg(mp);
}

/*
 * Common IP options parser.
 *
 * Setup routine: fill in *optp with options-parsing state, then
 * tail-call ipoptp_next to return the first option.
 */
uint8_t
ipoptp_first(ipoptp_t *optp, ipha_t *ipha)
{
	uint32_t totallen; /* total length of all options */

	totallen = ipha->ipha_version_and_hdr_length -
	    (uint8_t)((IP_VERSION << 4) + IP_SIMPLE_HDR_LENGTH_IN_WORDS);
	totallen <<= 2;
	optp->ipoptp_next = (uint8_t *)(&ipha[1]);
	optp->ipoptp_end = optp->ipoptp_next + totallen;
	optp->ipoptp_flags = 0;
	return (ipoptp_next(optp));
}

/* Like above but without an ipha_t */
uint8_t
ipoptp_first2(ipoptp_t *optp, uint32_t totallen, uint8_t *opt)
{
	optp->ipoptp_next = opt;
	optp->ipoptp_end = optp->ipoptp_next + totallen;
	optp->ipoptp_flags = 0;
	return (ipoptp_next(optp));
}

/*
 * Common IP options parser: extract next option.
 */
uint8_t
ipoptp_next(ipoptp_t *optp)
{
	uint8_t *end = optp->ipoptp_end;
	uint8_t *cur = optp->ipoptp_next;
	uint8_t opt, len, pointer;

	/*
	 * If cur > end already, then the ipoptp_end or ipoptp_next pointer
	 * has been corrupted.
	 */
	ASSERT(cur <= end);

	if (cur == end)
		return (IPOPT_EOL);

	opt = cur[IPOPT_OPTVAL];

	/*
	 * Skip any NOP options.
	 */
	while (opt == IPOPT_NOP) {
		cur++;
		if (cur == end)
			return (IPOPT_EOL);
		opt = cur[IPOPT_OPTVAL];
	}

	if (opt == IPOPT_EOL)
		return (IPOPT_EOL);

	/*
	 * Option requiring a length.
	 */
	if ((cur + 1) >= end) {
		optp->ipoptp_flags |= IPOPTP_ERROR;
		return (IPOPT_EOL);
	}
	len = cur[IPOPT_OLEN];
	if (len < 2) {
		optp->ipoptp_flags |= IPOPTP_ERROR;
		return (IPOPT_EOL);
	}
	optp->ipoptp_cur = cur;
	optp->ipoptp_len = len;
	optp->ipoptp_next = cur + len;
	if (cur + len > end) {
		optp->ipoptp_flags |= IPOPTP_ERROR;
		return (IPOPT_EOL);
	}

	/*
	 * For the options which require a pointer field, make sure
	 * its there, and make sure it points to either something
	 * inside this option, or the end of the option.
	 */
	switch (opt) {
	case IPOPT_RR:
	case IPOPT_TS:
	case IPOPT_LSRR:
	case IPOPT_SSRR:
		if (len <= IPOPT_OFFSET) {
			optp->ipoptp_flags |= IPOPTP_ERROR;
			return (opt);
		}
		pointer = cur[IPOPT_OFFSET];
		if (pointer - 1 > len) {
			optp->ipoptp_flags |= IPOPTP_ERROR;
			return (opt);
		}
		break;
	}

	/*
	 * Sanity check the pointer field based on the type of the
	 * option.
	 */
	switch (opt) {
	case IPOPT_RR:
	case IPOPT_SSRR:
	case IPOPT_LSRR:
		if (pointer < IPOPT_MINOFF_SR)
			optp->ipoptp_flags |= IPOPTP_ERROR;
		break;
	case IPOPT_TS:
		if (pointer < IPOPT_MINOFF_IT)
			optp->ipoptp_flags |= IPOPTP_ERROR;
		/*
		 * Note that the Internet Timestamp option also
		 * contains two four bit fields (the Overflow field,
		 * and the Flag field), which follow the pointer
		 * field.  We don't need to check that these fields
		 * fall within the length of the option because this
		 * was implicitely done above.  We've checked that the
		 * pointer value is at least IPOPT_MINOFF_IT, and that
		 * it falls within the option.  Since IPOPT_MINOFF_IT >
		 * IPOPT_POS_OV_FLG, we don't need the explicit check.
		 */
		ASSERT(len > IPOPT_POS_OV_FLG);
		break;
	}

	return (opt);
}

/*
 * Use the outgoing IP header to create an IP_OPTIONS option the way
 * it was passed down from the application.
 *
 * This is compatible with BSD in that it returns
 * the reverse source route with the final destination
 * as the last entry. The first 4 bytes of the option
 * will contain the final destination.
 */
int
ip_opt_get_user(conn_t *connp, uchar_t *buf)
{
	ipoptp_t	opts;
	uchar_t		*opt;
	uint8_t		optval;
	uint8_t		optlen;
	uint32_t	len = 0;
	uchar_t		*buf1 = buf;
	uint32_t	totallen;
	ipaddr_t	dst;
	ip_pkt_t	*ipp = &connp->conn_xmit_ipp;

	if (!(ipp->ipp_fields & IPPF_IPV4_OPTIONS))
		return (0);

	totallen = ipp->ipp_ipv4_options_len;
	if (totallen & 0x3)
		return (0);

	buf += IP_ADDR_LEN;	/* Leave room for final destination */
	len += IP_ADDR_LEN;
	bzero(buf1, IP_ADDR_LEN);

	dst = connp->conn_faddr_v4;

	for (optval = ipoptp_first2(&opts, totallen, ipp->ipp_ipv4_options);
	    optval != IPOPT_EOL;
	    optval = ipoptp_next(&opts)) {
		int	off;

		opt = opts.ipoptp_cur;
		if ((opts.ipoptp_flags & IPOPTP_ERROR) != 0) {
			break;
		}
		optlen = opts.ipoptp_len;

		switch (optval) {
		case IPOPT_SSRR:
		case IPOPT_LSRR:

			/*
			 * Insert destination as the first entry in the source
			 * route and move down the entries on step.
			 * The last entry gets placed at buf1.
			 */
			buf[IPOPT_OPTVAL] = optval;
			buf[IPOPT_OLEN] = optlen;
			buf[IPOPT_OFFSET] = optlen;

			off = optlen - IP_ADDR_LEN;
			if (off < 0) {
				/* No entries in source route */
				break;
			}
			/* Last entry in source route if not already set */
			if (dst == INADDR_ANY)
				bcopy(opt + off, buf1, IP_ADDR_LEN);
			off -= IP_ADDR_LEN;

			while (off > 0) {
				bcopy(opt + off,
				    buf + off + IP_ADDR_LEN,
				    IP_ADDR_LEN);
				off -= IP_ADDR_LEN;
			}
			/* ipha_dst into first slot */
			bcopy(&dst, buf + off + IP_ADDR_LEN,
			    IP_ADDR_LEN);
			buf += optlen;
			len += optlen;
			break;

		default:
			bcopy(opt, buf, optlen);
			buf += optlen;
			len += optlen;
			break;
		}
	}
done:
	/* Pad the resulting options */
	while (len & 0x3) {
		*buf++ = IPOPT_EOL;
		len++;
	}
	return (len);
}

/*
 * Update any record route or timestamp options to include this host.
 * Reverse any source route option.
 * This routine assumes that the options are well formed i.e. that they
 * have already been checked.
 */
static void
icmp_options_update(ipha_t *ipha)
{
	ipoptp_t	opts;
	uchar_t		*opt;
	uint8_t		optval;
	ipaddr_t	src;		/* Our local address */
	ipaddr_t	dst;

	ip2dbg(("icmp_options_update\n"));
	src = ipha->ipha_src;
	dst = ipha->ipha_dst;

	for (optval = ipoptp_first(&opts, ipha);
	    optval != IPOPT_EOL;
	    optval = ipoptp_next(&opts)) {
		ASSERT((opts.ipoptp_flags & IPOPTP_ERROR) == 0);
		opt = opts.ipoptp_cur;
		ip2dbg(("icmp_options_update: opt %d, len %d\n",
		    optval, opts.ipoptp_len));
		switch (optval) {
			int off1, off2;
		case IPOPT_SSRR:
		case IPOPT_LSRR:
			/*
			 * Reverse the source route.  The first entry
			 * should be the next to last one in the current
			 * source route (the last entry is our address).
			 * The last entry should be the final destination.
			 */
			off1 = IPOPT_MINOFF_SR - 1;
			off2 = opt[IPOPT_OFFSET] - IP_ADDR_LEN - 1;
			if (off2 < 0) {
				/* No entries in source route */
				ip1dbg((
				    "icmp_options_update: bad src route\n"));
				break;
			}
			bcopy((char *)opt + off2, &dst, IP_ADDR_LEN);
			bcopy(&ipha->ipha_dst, (char *)opt + off2, IP_ADDR_LEN);
			bcopy(&dst, &ipha->ipha_dst, IP_ADDR_LEN);
			off2 -= IP_ADDR_LEN;

			while (off1 < off2) {
				bcopy((char *)opt + off1, &src, IP_ADDR_LEN);
				bcopy((char *)opt + off2, (char *)opt + off1,
				    IP_ADDR_LEN);
				bcopy(&src, (char *)opt + off2, IP_ADDR_LEN);
				off1 += IP_ADDR_LEN;
				off2 -= IP_ADDR_LEN;
			}
			opt[IPOPT_OFFSET] = IPOPT_MINOFF_SR;
			break;
		}
	}
}

/*
 * Process received ICMP Redirect messages.
 * Assumes the caller has verified that the headers are in the pulled up mblk.
 * Consumes mp.
 */
static void
icmp_redirect_v4(mblk_t *mp, ipha_t *ipha, icmph_t *icmph, ip_recv_attr_t *ira)
{
	ire_t		*ire, *nire;
	ire_t		*prev_ire;
	ipaddr_t  	src, dst, gateway;
	ip_stack_t	*ipst = ira->ira_ill->ill_ipst;
	ipha_t		*inner_ipha;	/* Inner IP header */

	/* Caller already pulled up everything. */
	inner_ipha = (ipha_t *)&icmph[1];
	src = ipha->ipha_src;
	dst = inner_ipha->ipha_dst;
	gateway = icmph->icmph_rd_gateway;
	/* Make sure the new gateway is reachable somehow. */
	ire = ire_ftable_lookup_v4(gateway, 0, 0, IRE_ONLINK, NULL,
	    ALL_ZONES, NULL, MATCH_IRE_TYPE, 0, ipst, NULL);
	/*
	 * Make sure we had a route for the dest in question and that
	 * that route was pointing to the old gateway (the source of the
	 * redirect packet.)
	 * Note: this merely says that there is some IRE which matches that
	 * gateway; not that the longest match matches that gateway.
	 */
	prev_ire = ire_ftable_lookup_v4(dst, 0, src, 0, NULL, ALL_ZONES,
	    NULL, MATCH_IRE_GW, 0, ipst, NULL);
	/*
	 * Check that
	 *	the redirect was not from ourselves
	 *	the new gateway and the old gateway are directly reachable
	 */
	if (prev_ire == NULL || ire == NULL ||
	    (prev_ire->ire_type & (IRE_LOCAL|IRE_LOOPBACK)) ||
	    (prev_ire->ire_flags & (RTF_REJECT|RTF_BLACKHOLE)) ||
	    !(ire->ire_type & IRE_IF_ALL)) {
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInBadRedirects);
		ip_drop_input("icmpInBadRedirects - ire", mp, ira->ira_ill);
		freemsg(mp);
		if (ire != NULL)
			ire_refrele(ire);
		if (prev_ire != NULL)
			ire_refrele(prev_ire);
		return;
	}

	ire_refrele(prev_ire);
	ire_refrele(ire);

	/*
	 * TODO: more precise handling for cases 0, 2, 3, the latter two
	 * require TOS routing
	 */
	switch (icmph->icmph_code) {
	case 0:
	case 1:
		/* TODO: TOS specificity for cases 2 and 3 */
	case 2:
	case 3:
		break;
	default:
		BUMP_MIB(&ipst->ips_icmp_mib, icmpInBadRedirects);
		ip_drop_input("icmpInBadRedirects - code", mp, ira->ira_ill);
		freemsg(mp);
		return;
	}
	/*
	 * Create a Route Association.  This will allow us to remember that
	 * someone we believe told us to use the particular gateway.
	 */
	ire = ire_create(
	    (uchar_t *)&dst,			/* dest addr */
	    (uchar_t *)&ip_g_all_ones,		/* mask */
	    (uchar_t *)&gateway,		/* gateway addr */
	    IRE_HOST,
	    NULL,				/* ill */
	    ALL_ZONES,
	    (RTF_DYNAMIC | RTF_GATEWAY | RTF_HOST),
	    NULL,				/* tsol_gc_t */
	    ipst);

	if (ire == NULL) {
		freemsg(mp);
		return;
	}
	nire = ire_add(ire);
	/* Check if it was a duplicate entry */
	if (nire != NULL && nire != ire) {
		ASSERT(nire->ire_identical_ref > 1);
		ire_delete(nire);
		ire_refrele(nire);
		nire = NULL;
	}
	ire = nire;
	if (ire != NULL) {
		ire_refrele(ire);		/* Held in ire_add */

		/* tell routing sockets that we received a redirect */
		ip_rts_change(RTM_REDIRECT, dst, gateway, IP_HOST_MASK, 0, src,
		    (RTF_DYNAMIC | RTF_GATEWAY | RTF_HOST), 0,
		    (RTA_DST | RTA_GATEWAY | RTA_NETMASK | RTA_AUTHOR), ipst);
	}

	/*
	 * Delete any existing IRE_HOST type redirect ires for this destination.
	 * This together with the added IRE has the effect of
	 * modifying an existing redirect.
	 */
	prev_ire = ire_ftable_lookup_v4(dst, 0, src, IRE_HOST, NULL,
	    ALL_ZONES, NULL, (MATCH_IRE_GW | MATCH_IRE_TYPE), 0, ipst, NULL);
	if (prev_ire != NULL) {
		if (prev_ire ->ire_flags & RTF_DYNAMIC)
			ire_delete(prev_ire);
		ire_refrele(prev_ire);
	}

	freemsg(mp);
}

/*
 * Generate an ICMP parameter problem message.
 * When called from ip_output side a minimal ip_recv_attr_t needs to be
 * constructed by the caller.
 */
static void
icmp_param_problem(mblk_t *mp, uint8_t ptr, ip_recv_attr_t *ira)
{
	icmph_t	icmph;
	ip_stack_t	*ipst = ira->ira_ill->ill_ipst;

	mp = icmp_pkt_err_ok(mp, ira);
	if (mp == NULL)
		return;

	bzero(&icmph, sizeof (icmph_t));
	icmph.icmph_type = ICMP_PARAM_PROBLEM;
	icmph.icmph_pp_ptr = ptr;
	BUMP_MIB(&ipst->ips_icmp_mib, icmpOutParmProbs);
	icmp_pkt(mp, &icmph, sizeof (icmph_t), ira);
}

/*
 * Build and ship an IPv4 ICMP message using the packet data in mp, and
 * the ICMP header pointed to by "stuff".  (May be called as writer.)
 * Note: assumes that icmp_pkt_err_ok has been called to verify that
 * an icmp error packet can be sent.
 * Assigns an appropriate source address to the packet. If ipha_dst is
 * one of our addresses use it for source. Otherwise let ip_output_simple
 * pick the source address.
 */
static void
icmp_pkt(mblk_t *mp, void *stuff, size_t len, ip_recv_attr_t *ira)
{
	ipaddr_t dst;
	icmph_t	*icmph;
	ipha_t	*ipha;
	uint_t	len_needed;
	size_t	msg_len;
	mblk_t	*mp1;
	ipaddr_t src;
	ire_t	*ire;
	ip_xmit_attr_t ixas;
	ip_stack_t *ipst = ira->ira_ill->ill_ipst;

	ipha = (ipha_t *)mp->b_rptr;

	bzero(&ixas, sizeof (ixas));
	ixas.ixa_flags = IXAF_BASIC_SIMPLE_V4;
	ixas.ixa_zoneid = ira->ira_zoneid;
	ixas.ixa_ifindex = 0;
	ixas.ixa_ipst = ipst;
	ixas.ixa_cred = kcred;
	ixas.ixa_cpid = NOPID;
	ixas.ixa_tsl = ira->ira_tsl;	/* Behave as a multi-level responder */
	ixas.ixa_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;

	if (ira->ira_flags & IRAF_IPSEC_SECURE) {
		/*
		 * Apply IPsec based on how IPsec was applied to
		 * the packet that had the error.
		 *
		 * If it was an outbound packet that caused the ICMP
		 * error, then the caller will have setup the IRA
		 * appropriately.
		 */
		if (!ipsec_in_to_out(ira, &ixas, mp, ipha, NULL)) {
			BUMP_MIB(&ipst->ips_ip_mib, ipIfStatsOutDiscards);
			/* Note: mp already consumed and ip_drop_packet done */
			return;
		}
	} else {
		/*
		 * This is in clear. The icmp message we are building
		 * here should go out in clear, independent of our policy.
		 */
		ixas.ixa_flags |= IXAF_NO_IPSEC;
	}

	/* Remember our eventual destination */
	dst = ipha->ipha_src;

	/*
	 * If the packet was for one of our unicast addresses, make
	 * sure we respond with that as the source. Otherwise
	 * have ip_output_simple pick the source address.
	 */
	ire = ire_ftable_lookup_v4(ipha->ipha_dst, 0, 0,
	    (IRE_LOCAL|IRE_LOOPBACK), NULL, ira->ira_zoneid, NULL,
	    MATCH_IRE_TYPE|MATCH_IRE_ZONEONLY, 0, ipst, NULL);
	if (ire != NULL) {
		ire_refrele(ire);
		src = ipha->ipha_dst;
	} else {
		src = INADDR_ANY;
		ixas.ixa_flags |= IXAF_SET_SOURCE;
	}

	/*
	 * Check if we can send back more then 8 bytes in addition to
	 * the IP header.  We try to send 64 bytes of data and the internal
	 * header in the special cases of ipv4 encapsulated ipv4 or ipv6.
	 */
	len_needed = IPH_HDR_LENGTH(ipha);
	if (ipha->ipha_protocol == IPPROTO_ENCAP ||
	    ipha->ipha_protocol == IPPROTO_IPV6) {
		if (!pullupmsg(mp, -1)) {
			BUMP_MIB(&ipst->ips_ip_mib, ipIfStatsOutDiscards);
			ip_drop_output("ipIfStatsOutDiscards", mp, NULL);
			freemsg(mp);
			return;
		}
		ipha = (ipha_t *)mp->b_rptr;

		if (ipha->ipha_protocol == IPPROTO_ENCAP) {
			len_needed += IPH_HDR_LENGTH(((uchar_t *)ipha +
			    len_needed));
		} else {
			ip6_t *ip6h = (ip6_t *)((uchar_t *)ipha + len_needed);

			ASSERT(ipha->ipha_protocol == IPPROTO_IPV6);
			len_needed += ip_hdr_length_v6(mp, ip6h);
		}
	}
	len_needed += ipst->ips_ip_icmp_return;
	msg_len = msgdsize(mp);
	if (msg_len > len_needed) {
		(void) adjmsg(mp, len_needed - msg_len);
		msg_len = len_needed;
	}
	mp1 = allocb(sizeof (icmp_ipha) + len, BPRI_MED);
	if (mp1 == NULL) {
		BUMP_MIB(&ipst->ips_icmp_mib, icmpOutErrors);
		freemsg(mp);
		return;
	}
	mp1->b_cont = mp;
	mp = mp1;

	/*
	 * Set IXAF_TRUSTED_ICMP so we can let the ICMP messages this
	 * node generates be accepted in peace by all on-host destinations.
	 * If we do NOT assume that all on-host destinations trust
	 * self-generated ICMP messages, then rework here, ip6.c, and spd.c.
	 * (Look for IXAF_TRUSTED_ICMP).
	 */
	ixas.ixa_flags |= IXAF_TRUSTED_ICMP;

	ipha = (ipha_t *)mp->b_rptr;
	mp1->b_wptr = (uchar_t *)ipha + (sizeof (icmp_ipha) + len);
	*ipha = icmp_ipha;
	ipha->ipha_src = src;
	ipha->ipha_dst = dst;
	ipha->ipha_ttl = ipst->ips_ip_def_ttl;
	msg_len += sizeof (icmp_ipha) + len;
	if (msg_len > IP_MAXPACKET) {
		(void) adjmsg(mp, IP_MAXPACKET - msg_len);
		msg_len = IP_MAXPACKET;
	}
	ipha->ipha_length = htons((uint16_t)msg_len);
	icmph = (icmph_t *)&ipha[1];
	bcopy(stuff, icmph, len);
	icmph->icmph_checksum = 0;
	icmph->icmph_checksum = IP_CSUM(mp, (int32_t)sizeof (ipha_t), 0);
	BUMP_MIB(&ipst->ips_icmp_mib, icmpOutMsgs);

	(void) ip_output_simple(mp, &ixas);
	ixa_cleanup(&ixas);
}

/*
 * Determine if an ICMP error packet can be sent given the rate limit.
 * The limit consists of an average frequency (icmp_pkt_err_interval measured
 * in milliseconds) and a burst size. Burst size number of packets can
 * be sent arbitrarely closely spaced.
 * The state is tracked using two variables to implement an approximate
 * token bucket filter:
 *	icmp_pkt_err_last - lbolt value when the last burst started
 *	icmp_pkt_err_sent - number of packets sent in current burst
 */
boolean_t
icmp_err_rate_limit(ip_stack_t *ipst)
{
	clock_t now = TICK_TO_MSEC(ddi_get_lbolt());
	uint_t refilled; /* Number of packets refilled in tbf since last */
	/* Guard against changes by loading into local variable */
	uint_t err_interval = ipst->ips_ip_icmp_err_interval;

	if (err_interval == 0)
		return (B_FALSE);

	if (ipst->ips_icmp_pkt_err_last > now) {
		/* 100HZ lbolt in ms for 32bit arch wraps every 49.7 days */
		ipst->ips_icmp_pkt_err_last = 0;
		ipst->ips_icmp_pkt_err_sent = 0;
	}
	/*
	 * If we are in a burst update the token bucket filter.
	 * Update the "last" time to be close to "now" but make sure
	 * we don't loose precision.
	 */
	if (ipst->ips_icmp_pkt_err_sent != 0) {
		refilled = (now - ipst->ips_icmp_pkt_err_last)/err_interval;
		if (refilled > ipst->ips_icmp_pkt_err_sent) {
			ipst->ips_icmp_pkt_err_sent = 0;
		} else {
			ipst->ips_icmp_pkt_err_sent -= refilled;
			ipst->ips_icmp_pkt_err_last += refilled * err_interval;
		}
	}
	if (ipst->ips_icmp_pkt_err_sent == 0) {
		/* Start of new burst */
		ipst->ips_icmp_pkt_err_last = now;
	}
	if (ipst->ips_icmp_pkt_err_sent < ipst->ips_ip_icmp_err_burst) {
		ipst->ips_icmp_pkt_err_sent++;
		ip1dbg(("icmp_err_rate_limit: %d sent in burst\n",
		    ipst->ips_icmp_pkt_err_sent));
		return (B_FALSE);
	}
	ip1dbg(("icmp_err_rate_limit: dropped\n"));
	return (B_TRUE);
}

/*
 * Check if it is ok to send an IPv4 ICMP error packet in
 * response to the IPv4 packet in mp.
 * Free the message and return null if no
 * ICMP error packet should be sent.
 */
static mblk_t *
icmp_pkt_err_ok(mblk_t *mp, ip_recv_attr_t *ira)
{
	ip_stack_t	*ipst = ira->ira_ill->ill_ipst;
	icmph_t	*icmph;
	ipha_t	*ipha;
	uint_t	len_needed;

	if (!mp)
		return (NULL);
	ipha = (ipha_t *)mp->b_rptr;
	if (ip_csum_hdr(ipha)) {
		BUMP_MIB(&ipst->ips_ip_mib, ipIfStatsInCksumErrs);
		ip_drop_input("ipIfStatsInCksumErrs", mp, NULL);
		freemsg(mp);
		return (NULL);
	}
	if (ip_type_v4(ipha->ipha_dst, ipst) == IRE_BROADCAST ||
	    ip_type_v4(ipha->ipha_src, ipst) == IRE_BROADCAST ||
	    CLASSD(ipha->ipha_dst) ||
	    CLASSD(ipha->ipha_src) ||
	    (ntohs(ipha->ipha_fragment_offset_and_flags) & IPH_OFFSET)) {
		/* Note: only errors to the fragment with offset 0 */
		BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDrops);
		freemsg(mp);
		return (NULL);
	}
	if (ipha->ipha_protocol == IPPROTO_ICMP) {
		/*
		 * Check the ICMP type.  RFC 1122 sez:  don't send ICMP
		 * errors in response to any ICMP errors.
		 */
		len_needed = IPH_HDR_LENGTH(ipha) + ICMPH_SIZE;
		if (mp->b_wptr - mp->b_rptr < len_needed) {
			if (!pullupmsg(mp, len_needed)) {
				BUMP_MIB(&ipst->ips_icmp_mib, icmpInErrors);
				freemsg(mp);
				return (NULL);
			}
			ipha = (ipha_t *)mp->b_rptr;
		}
		icmph = (icmph_t *)
		    (&((char *)ipha)[IPH_HDR_LENGTH(ipha)]);
		switch (icmph->icmph_type) {
		case ICMP_DEST_UNREACHABLE:
		case ICMP_SOURCE_QUENCH:
		case ICMP_TIME_EXCEEDED:
		case ICMP_PARAM_PROBLEM:
		case ICMP_REDIRECT:
			BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDrops);
			freemsg(mp);
			return (NULL);
		default:
			break;
		}
	}
	/*
	 * If this is a labeled system, then check to see if we're allowed to
	 * send a response to this particular sender.  If not, then just drop.
	 */
	if (is_system_labeled() && !tsol_can_reply_error(mp, ira)) {
		ip2dbg(("icmp_pkt_err_ok: can't respond to packet\n"));
		BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDrops);
		freemsg(mp);
		return (NULL);
	}
	if (icmp_err_rate_limit(ipst)) {
		/*
		 * Only send ICMP error packets every so often.
		 * This should be done on a per port/source basis,
		 * but for now this will suffice.
		 */
		freemsg(mp);
		return (NULL);
	}
	return (mp);
}

/*
 * Called when a packet was sent out the same link that it arrived on.
 * Check if it is ok to send a redirect and then send it.
 */
void
ip_send_potential_redirect_v4(mblk_t *mp, ipha_t *ipha, ire_t *ire,
    ip_recv_attr_t *ira)
{
	ip_stack_t	*ipst = ira->ira_ill->ill_ipst;
	ipaddr_t	src, nhop;
	mblk_t		*mp1;
	ire_t		*nhop_ire;

	/*
	 * Check the source address to see if it originated
	 * on the same logical subnet it is going back out on.
	 * If so, we should be able to send it a redirect.
	 * Avoid sending a redirect if the destination
	 * is directly connected (i.e., we matched an IRE_ONLINK),
	 * or if the packet was source routed out this interface.
	 *
	 * We avoid sending a redirect if the
	 * destination is directly connected
	 * because it is possible that multiple
	 * IP subnets may have been configured on
	 * the link, and the source may not
	 * be on the same subnet as ip destination,
	 * even though they are on the same
	 * physical link.
	 */
	if ((ire->ire_type & IRE_ONLINK) ||
	    ip_source_routed(ipha, ipst))
		return;

	nhop_ire = ire_nexthop(ire);
	if (nhop_ire == NULL)
		return;

	nhop = nhop_ire->ire_addr;

	if (nhop_ire->ire_type & IRE_IF_CLONE) {
		ire_t	*ire2;

		/* Follow ire_dep_parent to find non-clone IRE_INTERFACE */
		mutex_enter(&nhop_ire->ire_lock);
		ire2 = nhop_ire->ire_dep_parent;
		if (ire2 != NULL)
			ire_refhold(ire2);
		mutex_exit(&nhop_ire->ire_lock);
		ire_refrele(nhop_ire);
		nhop_ire = ire2;
	}
	if (nhop_ire == NULL)
		return;

	ASSERT(!(nhop_ire->ire_type & IRE_IF_CLONE));

	src = ipha->ipha_src;

	/*
	 * We look at the interface ire for the nexthop,
	 * to see if ipha_src is in the same subnet
	 * as the nexthop.
	 */
	if ((src & nhop_ire->ire_mask) == (nhop & nhop_ire->ire_mask)) {
		/*
		 * The source is directly connected.
		 */
		mp1 = copymsg(mp);
		if (mp1 != NULL) {
			icmp_send_redirect(mp1, nhop, ira);
		}
	}
	ire_refrele(nhop_ire);
}

/*
 * Generate an ICMP redirect message.
 */
static void
icmp_send_redirect(mblk_t *mp, ipaddr_t gateway, ip_recv_attr_t *ira)
{
	icmph_t	icmph;
	ip_stack_t *ipst = ira->ira_ill->ill_ipst;

	mp = icmp_pkt_err_ok(mp, ira);
	if (mp == NULL)
		return;

	bzero(&icmph, sizeof (icmph_t));
	icmph.icmph_type = ICMP_REDIRECT;
	icmph.icmph_code = 1;
	icmph.icmph_rd_gateway = gateway;
	BUMP_MIB(&ipst->ips_icmp_mib, icmpOutRedirects);
	icmp_pkt(mp, &icmph, sizeof (icmph_t), ira);
}

/*
 * Generate an ICMP time exceeded message.
 */
void
icmp_time_exceeded(mblk_t *mp, uint8_t code, ip_recv_attr_t *ira)
{
	icmph_t	icmph;
	ip_stack_t *ipst = ira->ira_ill->ill_ipst;

	mp = icmp_pkt_err_ok(mp, ira);
	if (mp == NULL)
		return;

	bzero(&icmph, sizeof (icmph_t));
	icmph.icmph_type = ICMP_TIME_EXCEEDED;
	icmph.icmph_code = code;
	BUMP_MIB(&ipst->ips_icmp_mib, icmpOutTimeExcds);
	icmp_pkt(mp, &icmph, sizeof (icmph_t), ira);
}

/*
 * Generate an ICMP unreachable message.
 * When called from ip_output side a minimal ip_recv_attr_t needs to be
 * constructed by the caller.
 */
void
icmp_unreachable(mblk_t *mp, uint8_t code, ip_recv_attr_t *ira)
{
	icmph_t	icmph;
	ip_stack_t *ipst = ira->ira_ill->ill_ipst;

	mp = icmp_pkt_err_ok(mp, ira);
	if (mp == NULL)
		return;

	bzero(&icmph, sizeof (icmph_t));
	icmph.icmph_type = ICMP_DEST_UNREACHABLE;
	icmph.icmph_code = code;
	BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDestUnreachs);
	icmp_pkt(mp, &icmph, sizeof (icmph_t), ira);
}

/*
 * Latch in the IPsec state for a stream based the policy in the listener
 * and the actions in the ip_recv_attr_t.
 * Called directly from TCP and SCTP.
 */
boolean_t
ip_ipsec_policy_inherit(conn_t *connp, conn_t *lconnp, ip_recv_attr_t *ira)
{
	ASSERT(lconnp->conn_policy != NULL);
	ASSERT(connp->conn_policy == NULL);

	IPPH_REFHOLD(lconnp->conn_policy);
	connp->conn_policy = lconnp->conn_policy;

	if (ira->ira_ipsec_action != NULL) {
		if (connp->conn_latch == NULL) {
			connp->conn_latch = iplatch_create();
			if (connp->conn_latch == NULL)
				return (B_FALSE);
		}
		ipsec_latch_inbound(connp, ira);
	}
	return (B_TRUE);
}

/*
 * Verify whether or not the IP address is a valid local address.
 * Could be a unicast, including one for a down interface.
 * If allow_mcbc then a multicast or broadcast address is also
 * acceptable.
 *
 * In the case of a broadcast/multicast address, however, the
 * upper protocol is expected to reset the src address
 * to zero when we return IPVL_MCAST/IPVL_BCAST so that
 * no packets are emitted with broadcast/multicast address as
 * source address (that violates hosts requirements RFC 1122)
 * The addresses valid for bind are:
 *	(1) - INADDR_ANY (0)
 *	(2) - IP address of an UP interface
 *	(3) - IP address of a DOWN interface
 *	(4) - valid local IP broadcast addresses. In this case
 *	the conn will only receive packets destined to
 *	the specified broadcast address.
 *	(5) - a multicast address. In this case
 *	the conn will only receive packets destined to
 *	the specified multicast address. Note: the
 *	application still has to issue an
 *	IP_ADD_MEMBERSHIP socket option.
 *
 * In all the above cases, the bound address must be valid in the current zone.
 * When the address is loopback, multicast or broadcast, there might be many
 * matching IREs so bind has to look up based on the zone.
 */
ip_laddr_t
ip_laddr_verify_v4(ipaddr_t src_addr, zoneid_t zoneid,
    ip_stack_t *ipst, boolean_t allow_mcbc)
{
	ire_t *src_ire;

	ASSERT(src_addr != INADDR_ANY);

	src_ire = ire_ftable_lookup_v4(src_addr, 0, 0, 0,
	    NULL, zoneid, NULL, MATCH_IRE_ZONEONLY, 0, ipst, NULL);

	/*
	 * If an address other than in6addr_any is requested,
	 * we verify that it is a valid address for bind
	 * Note: Following code is in if-else-if form for
	 * readability compared to a condition check.
	 */
	if (src_ire != NULL && (src_ire->ire_type & (IRE_LOCAL|IRE_LOOPBACK))) {
		/*
		 * (2) Bind to address of local UP interface
		 */
		ire_refrele(src_ire);
		return (IPVL_UNICAST_UP);
	} else if (src_ire != NULL && src_ire->ire_type & IRE_BROADCAST) {
		/*
		 * (4) Bind to broadcast address
		 */
		ire_refrele(src_ire);
		if (allow_mcbc)
			return (IPVL_BCAST);
		else
			return (IPVL_BAD);
	} else if (CLASSD(src_addr)) {
		/* (5) bind to multicast address. */
		if (src_ire != NULL)
			ire_refrele(src_ire);

		if (allow_mcbc)
			return (IPVL_MCAST);
		else
			return (IPVL_BAD);
	} else {
		ipif_t *ipif;

		/*
		 * (3) Bind to address of local DOWN interface?
		 * (ipif_lookup_addr() looks up all interfaces
		 * but we do not get here for UP interfaces
		 * - case (2) above)
		 */
		if (src_ire != NULL)
			ire_refrele(src_ire);

		ipif = ipif_lookup_addr(src_addr, NULL, zoneid, ipst);
		if (ipif == NULL)
			return (IPVL_BAD);

		/* Not a useful source? */
		if (ipif->ipif_flags & (IPIF_NOLOCAL | IPIF_ANYCAST)) {
			ipif_refrele(ipif);
			return (IPVL_BAD);
		}
		ipif_refrele(ipif);
		return (IPVL_UNICAST_DOWN);
	}
}

/*
 * Insert in the bind fanout for IPv4 and IPv6.
 * The caller should already have used ip_laddr_verify_v*() before calling
 * this.
 */
int
ip_laddr_fanout_insert(conn_t *connp)
{
	int		error;

	/*
	 * Allow setting new policies. For example, disconnects result
	 * in us being called. As we would have set conn_policy_cached
	 * to B_TRUE before, we should set it to B_FALSE, so that policy
	 * can change after the disconnect.
	 */
	connp->conn_policy_cached = B_FALSE;

	error = ipcl_bind_insert(connp);
	if (error != 0) {
		if (connp->conn_anon_port) {
			(void) tsol_mlp_anon(crgetzone(connp->conn_cred),
			    connp->conn_mlp_type, connp->conn_proto,
			    ntohs(connp->conn_lport), B_FALSE);
		}
		connp->conn_mlp_type = mlptSingle;
	}
	return (error);
}

/*
 * Verify that both the source and destination addresses are valid. If
 * IPDF_VERIFY_DST is not set, then the destination address may be unreachable,
 * i.e. have no route to it.  Protocols like TCP want to verify destination
 * reachability, while tunnels do not.
 *
 * Determine the route, the interface, and (optionally) the source address
 * to use to reach a given destination.
 * Note that we allow connect to broadcast and multicast addresses when
 * IPDF_ALLOW_MCBC is set.
 * first_hop and dst_addr are normally the same, but if source routing
 * they will differ; in that case the first_hop is what we'll use for the
 * routing lookup but the dce and label checks will be done on dst_addr,
 *
 * If uinfo is set, then we fill in the best available information
 * we have for the destination. This is based on (in priority order) any
 * metrics and path MTU stored in a dce_t, route metrics, and finally the
 * ill_mtu.
 *
 * Tsol note: If we have a source route then dst_addr != firsthop. But we
 * always do the label check on dst_addr.
 */
int
ip_set_destination_v4(ipaddr_t *src_addrp, ipaddr_t dst_addr, ipaddr_t firsthop,
    ip_xmit_attr_t *ixa, iulp_t *uinfo, uint32_t flags, uint_t mac_mode)
{
	ire_t		*ire = NULL;
	int		error = 0;
	ipaddr_t	setsrc;				/* RTF_SETSRC */
	zoneid_t	zoneid = ixa->ixa_zoneid;	/* Honors SO_ALLZONES */
	ip_stack_t	*ipst = ixa->ixa_ipst;
	dce_t		*dce;
	uint_t		pmtu;
	uint_t		generation;
	nce_t		*nce;
	ill_t		*ill = NULL;
	boolean_t	multirt = B_FALSE;

	ASSERT(ixa->ixa_flags & IXAF_IS_IPV4);

	/*
	 * We never send to zero; the ULPs map it to the loopback address.
	 * We can't allow it since we use zero to mean unitialized in some
	 * places.
	 */
	ASSERT(dst_addr != INADDR_ANY);

	if (is_system_labeled()) {
		ts_label_t *tsl = NULL;

		error = tsol_check_dest(ixa->ixa_tsl, &dst_addr, IPV4_VERSION,
		    mac_mode, (flags & IPDF_ZONE_IS_GLOBAL) != 0, &tsl);
		if (error != 0)
			return (error);
		if (tsl != NULL) {
			/* Update the label */
			ip_xmit_attr_replace_tsl(ixa, tsl);
		}
	}

	setsrc = INADDR_ANY;
	/*
	 * Select a route; For IPMP interfaces, we would only select
	 * a "hidden" route (i.e., going through a specific under_ill)
	 * if ixa_ifindex has been specified.
	 */
	ire = ip_select_route_v4(firsthop, ixa, &generation, &setsrc, &error,
	    &multirt);
	ASSERT(ire != NULL);	/* IRE_NOROUTE if none found */
	if (error != 0)
		goto bad_addr;

	/*
	 * ire can't be a broadcast or multicast unless IPDF_ALLOW_MCBC is set.
	 * If IPDF_VERIFY_DST is set, the destination must be reachable;
	 * Otherwise the destination needn't be reachable.
	 *
	 * If we match on a reject or black hole, then we've got a
	 * local failure.  May as well fail out the connect() attempt,
	 * since it's never going to succeed.
	 */
	if (ire->ire_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
		/*
		 * If we're verifying destination reachability, we always want
		 * to complain here.
		 *
		 * If we're not verifying destination reachability but the
		 * destination has a route, we still want to fail on the
		 * temporary address and broadcast address tests.
		 *
		 * In both cases do we let the code continue so some reasonable
		 * information is returned to the caller. That enables the
		 * caller to use (and even cache) the IRE. conn_ip_ouput will
		 * use the generation mismatch path to check for the unreachable
		 * case thereby avoiding any specific check in the main path.
		 */
		ASSERT(generation == IRE_GENERATION_VERIFY);
		if (flags & IPDF_VERIFY_DST) {
			/*
			 * Set errno but continue to set up ixa_ire to be
			 * the RTF_REJECT|RTF_BLACKHOLE IRE.
			 * That allows callers to use ip_output to get an
			 * ICMP error back.
			 */
			if (!(ire->ire_type & IRE_HOST))
				error = ENETUNREACH;
			else
				error = EHOSTUNREACH;
		}
	}

	if ((ire->ire_type & (IRE_BROADCAST|IRE_MULTICAST)) &&
	    !(flags & IPDF_ALLOW_MCBC)) {
		ire_refrele(ire);
		ire = ire_reject(ipst, B_FALSE);
		generation = IRE_GENERATION_VERIFY;
		error = ENETUNREACH;
	}

	/* Cache things */
	if (ixa->ixa_ire != NULL)
		ire_refrele_notr(ixa->ixa_ire);
#ifdef DEBUG
	ire_refhold_notr(ire);
	ire_refrele(ire);
#endif
	ixa->ixa_ire = ire;
	ixa->ixa_ire_generation = generation;

	/*
	 * For multicast with multirt we have a flag passed back from
	 * ire_lookup_multi_ill_v4 since we don't have an IRE for each
	 * possible multicast address.
	 * We also need a flag for multicast since we can't check
	 * whether RTF_MULTIRT is set in ixa_ire for multicast.
	 */
	if (multirt) {
		ixa->ixa_postfragfn = ip_postfrag_multirt_v4;
		ixa->ixa_flags |= IXAF_MULTIRT_MULTICAST;
	} else {
		ixa->ixa_postfragfn = ire->ire_postfragfn;
		ixa->ixa_flags &= ~IXAF_MULTIRT_MULTICAST;
	}
	if (!(ire->ire_flags & (RTF_REJECT|RTF_BLACKHOLE))) {
		/* Get an nce to cache. */
		nce = ire_to_nce(ire, firsthop, NULL);
		if (nce == NULL) {
			/* Allocation failure? */
			ixa->ixa_ire_generation = IRE_GENERATION_VERIFY;
		} else {
			if (ixa->ixa_nce != NULL)
				nce_refrele(ixa->ixa_nce);
			ixa->ixa_nce = nce;
		}
	}

	/*
	 * If the source address is a loopback address, the
	 * destination had best be local or multicast.
	 * If we are sending to an IRE_LOCAL using a loopback source then
	 * it had better be the same zoneid.
	 */
	if (*src_addrp == htonl(INADDR_LOOPBACK)) {
		if ((ire->ire_type & IRE_LOCAL) && ire->ire_zoneid != zoneid) {
			ire = NULL;	/* Stored in ixa_ire */
			error = EADDRNOTAVAIL;
			goto bad_addr;
		}
		if (!(ire->ire_type & (IRE_LOOPBACK|IRE_LOCAL|IRE_MULTICAST))) {
			ire = NULL;	/* Stored in ixa_ire */
			error = EADDRNOTAVAIL;
			goto bad_addr;
		}
	}
	if (ire->ire_type & IRE_BROADCAST) {
		/*
		 * If the ULP didn't have a specified source, then we
		 * make sure we reselect the source when sending
		 * broadcasts out different interfaces.
		 */
		if (flags & IPDF_SELECT_SRC)
			ixa->ixa_flags |= IXAF_SET_SOURCE;
		else
			ixa->ixa_flags &= ~IXAF_SET_SOURCE;
	}

	/*
	 * Does the caller want us to pick a source address?
	 */
	if (flags & IPDF_SELECT_SRC) {
		ipaddr_t	src_addr;

		/*
		 * We use use ire_nexthop_ill to avoid the under ipmp
		 * interface for source address selection. Note that for ipmp
		 * probe packets, ixa_ifindex would have been specified, and
		 * the ip_select_route() invocation would have picked an ire
		 * will ire_ill pointing at an under interface.
		 */
		ill = ire_nexthop_ill(ire);

		/* If unreachable we have no ill but need some source */
		if (ill == NULL) {
			src_addr = htonl(INADDR_LOOPBACK);
			/* Make sure we look for a better source address */
			generation = SRC_GENERATION_VERIFY;
		} else {
			error = ip_select_source_v4(ill, setsrc, dst_addr,
			    ixa->ixa_multicast_ifaddr, zoneid,
			    ipst, &src_addr, &generation, NULL);
			if (error != 0) {
				ire = NULL;	/* Stored in ixa_ire */
				goto bad_addr;
			}
		}

		/*
		 * We allow the source address to to down.
		 * However, we check that we don't use the loopback address
		 * as a source when sending out on the wire.
		 */
		if ((src_addr == htonl(INADDR_LOOPBACK)) &&
		    !(ire->ire_type & (IRE_LOCAL|IRE_LOOPBACK|IRE_MULTICAST)) &&
		    !(ire->ire_flags & (RTF_REJECT|RTF_BLACKHOLE))) {
			ire = NULL;	/* Stored in ixa_ire */
			error = EADDRNOTAVAIL;
			goto bad_addr;
		}

		*src_addrp = src_addr;
		ixa->ixa_src_generation = generation;
	}

	if (flags & IPDF_UNIQUE_DCE) {
		/* Fallback to the default dce if allocation fails */
		dce = dce_lookup_and_add_v4(dst_addr, ipst);
		if (dce != NULL)
			generation = dce->dce_generation;
		else
			dce = dce_lookup_v4(dst_addr, ipst, &generation);
	} else {
		dce = dce_lookup_v4(dst_addr, ipst, &generation);
	}
	ASSERT(dce != NULL);
	if (ixa->ixa_dce != NULL)
		dce_refrele_notr(ixa->ixa_dce);
#ifdef DEBUG
	dce_refhold_notr(dce);
	dce_refrele(dce);
#endif
	ixa->ixa_dce = dce;
	ixa->ixa_dce_generation = generation;

	/*
	 * Make sure we don't leave an unreachable ixa_nce in place
	 * since ip_select_route is used when we unplumb i.e., remove
	 * references on ixa_ire, ixa_nce, and ixa_dce.
	 */
	nce = ixa->ixa_nce;
	if (nce != NULL && nce->nce_is_condemned) {
		nce_refrele(nce);
		ixa->ixa_nce = NULL;
		ixa->ixa_ire_generation = IRE_GENERATION_VERIFY;
	}

	/*
	 * The caller has set IXAF_PMTU_DISCOVERY if path MTU is desired.
	 * However, we can't do it for IPv4 multicast or broadcast.
	 */
	if (ire->ire_type & (IRE_BROADCAST|IRE_MULTICAST))
		ixa->ixa_flags &= ~IXAF_PMTU_DISCOVERY;

	/*
	 * Set initial value for fragmentation limit. Either conn_ip_output
	 * or ULP might updates it when there are routing changes.
	 * Handles a NULL ixa_ire->ire_ill or a NULL ixa_nce for RTF_REJECT.
	 */
	pmtu = ip_get_pmtu(ixa);
	ixa->ixa_fragsize = pmtu;
	/* Make sure ixa_fragsize and ixa_pmtu remain identical */
	if (ixa->ixa_flags & IXAF_VERIFY_PMTU)
		ixa->ixa_pmtu = pmtu;

	/*
	 * Extract information useful for some transports.
	 * First we look for DCE metrics. Then we take what we have in
	 * the metrics in the route, where the offlink is used if we have
	 * one.
	 */
	if (uinfo != NULL) {
		bzero(uinfo, sizeof (*uinfo));

		if (dce->dce_flags & DCEF_UINFO)
			*uinfo = dce->dce_uinfo;

		rts_merge_metrics(uinfo, &ire->ire_metrics);

		/* Allow ire_metrics to decrease the path MTU from above */
		if (uinfo->iulp_mtu == 0 || uinfo->iulp_mtu > pmtu)
			uinfo->iulp_mtu = pmtu;

		uinfo->iulp_localnet = (ire->ire_type & IRE_ONLINK) != 0;
		uinfo->iulp_loopback = (ire->ire_type & IRE_LOOPBACK) != 0;
		uinfo->iulp_local = (ire->ire_type & IRE_LOCAL) != 0;
	}

	if (ill != NULL)
		ill_refrele(ill);

	return (error);

bad_addr:
	if (ire != NULL)
		ire_refrele(ire);

	if (ill != NULL)
		ill_refrele(ill);

	/*
	 * Make sure we don't leave an unreachable ixa_nce in place
	 * since ip_select_route is used when we unplumb i.e., remove
	 * references on ixa_ire, ixa_nce, and ixa_dce.
	 */
	nce = ixa->ixa_nce;
	if (nce != NULL && nce->nce_is_condemned) {
		nce_refrele(nce);
		ixa->ixa_nce = NULL;
		ixa->ixa_ire_generation = IRE_GENERATION_VERIFY;
	}

	return (error);
}


/*
 * Get the base MTU for the case when path MTU discovery is not used.
 * Takes the MTU of the IRE into account.
 */
uint_t
ip_get_base_mtu(ill_t *ill, ire_t *ire)
{
	uint_t mtu = ill->ill_mtu;
	uint_t iremtu = ire->ire_metrics.iulp_mtu;

	if (iremtu != 0 && iremtu < mtu)
		mtu = iremtu;

	return (mtu);
}

/*
 * Get the PMTU for the attributes. Handles both IPv4 and IPv6.
 * Assumes that ixa_ire, dce, and nce have already been set up.
 *
 * The caller has set IXAF_PMTU_DISCOVERY if path MTU discovery is desired.
 * We avoid path MTU discovery if it is disabled with ndd.
 * Furtermore, if the path MTU is too small, then we don't set DF for IPv4.
 *
 * NOTE: We also used to turn it off for source routed packets. That
 * is no longer required since the dce is per final destination.
 */
uint_t
ip_get_pmtu(ip_xmit_attr_t *ixa)
{
	ip_stack_t	*ipst = ixa->ixa_ipst;
	dce_t		*dce;
	nce_t		*nce;
	ire_t		*ire;
	uint_t		pmtu;

	ire = ixa->ixa_ire;
	dce = ixa->ixa_dce;
	nce = ixa->ixa_nce;

	/*
	 * If path MTU discovery has been turned off by ndd, then we ignore
	 * any dce_pmtu and for IPv4 we will not set DF.
	 */
	if (!ipst->ips_ip_path_mtu_discovery)
		ixa->ixa_flags &= ~IXAF_PMTU_DISCOVERY;

	pmtu = IP_MAXPACKET;
	/*
	 * Decide whether whether IPv4 sets DF
	 * For IPv6 "no DF" means to use the 1280 mtu
	 */
	if (ixa->ixa_flags & IXAF_PMTU_DISCOVERY) {
		ixa->ixa_flags |= IXAF_PMTU_IPV4_DF;
	} else {
		ixa->ixa_flags &= ~IXAF_PMTU_IPV4_DF;
		if (!(ixa->ixa_flags & IXAF_IS_IPV4))
			pmtu = IPV6_MIN_MTU;
	}

	/* Check if the PMTU is to old before we use it */
	if ((dce->dce_flags & DCEF_PMTU) &&
	    TICK_TO_SEC(ddi_get_lbolt64()) - dce->dce_last_change_time >
	    ipst->ips_ip_pathmtu_interval) {
		/*
		 * Older than 20 minutes. Drop the path MTU information.
		 */
		mutex_enter(&dce->dce_lock);
		dce->dce_flags &= ~(DCEF_PMTU|DCEF_TOO_SMALL_PMTU);
		dce->dce_last_change_time = TICK_TO_SEC(ddi_get_lbolt64());
		mutex_exit(&dce->dce_lock);
		dce_increment_generation(dce);
	}

	/* The metrics on the route can lower the path MTU */
	if (ire->ire_metrics.iulp_mtu != 0 &&
	    ire->ire_metrics.iulp_mtu < pmtu)
		pmtu = ire->ire_metrics.iulp_mtu;

	/*
	 * If the path MTU is smaller than some minimum, we still use dce_pmtu
	 * above (would be 576 for IPv4 and 1280 for IPv6), but we clear
	 * IXAF_PMTU_IPV4_DF so that we avoid setting DF for IPv4.
	 */
	if (ixa->ixa_flags & IXAF_PMTU_DISCOVERY) {
		if (dce->dce_flags & DCEF_PMTU) {
			if (dce->dce_pmtu < pmtu)
				pmtu = dce->dce_pmtu;

			if (dce->dce_flags & DCEF_TOO_SMALL_PMTU) {
				ixa->ixa_flags |= IXAF_PMTU_TOO_SMALL;
				ixa->ixa_flags &= ~IXAF_PMTU_IPV4_DF;
			} else {
				ixa->ixa_flags &= ~IXAF_PMTU_TOO_SMALL;
				ixa->ixa_flags |= IXAF_PMTU_IPV4_DF;
			}
		} else {
			ixa->ixa_flags &= ~IXAF_PMTU_TOO_SMALL;
			ixa->ixa_flags |= IXAF_PMTU_IPV4_DF;
		}
	}

	/*
	 * If we have an IRE_LOCAL we use the loopback mtu instead of
	 * the ill for going out the wire i.e., IRE_LOCAL gets the same
	 * mtu as IRE_LOOPBACK.
	 */
	if (ire->ire_type & (IRE_LOCAL|IRE_LOOPBACK)) {
		uint_t loopback_mtu;

		loopback_mtu = (ire->ire_ipversion == IPV6_VERSION) ?
		    ip_loopback_mtu_v6plus : ip_loopback_mtuplus;

		if (loopback_mtu < pmtu)
			pmtu = loopback_mtu;
	} else if (nce != NULL) {
		/*
		 * Make sure we don't exceed the interface MTU.
		 * In the case of RTF_REJECT or RTF_BLACKHOLE we might not have
		 * an ill. We'd use the above IP_MAXPACKET in that case just
		 * to tell the transport something larger than zero.
		 */
		if (nce->nce_common->ncec_ill->ill_mtu < pmtu)
			pmtu = nce->nce_common->ncec_ill->ill_mtu;
		if (nce->nce_common->ncec_ill != nce->nce_ill &&
		    nce->nce_ill->ill_mtu < pmtu) {
			/*
			 * for interfaces in an IPMP group, the mtu of
			 * the nce_ill (under_ill) could be different
			 * from the mtu of the ncec_ill, so we take the
			 * min of the two.
			 */
			pmtu = nce->nce_ill->ill_mtu;
		}
	}

	/*
	 * Handle the IPV6_USE_MIN_MTU socket option or ancillary data.
	 * Only applies to IPv6.
	 */
	if (!(ixa->ixa_flags & IXAF_IS_IPV4)) {
		if (ixa->ixa_flags & IXAF_USE_MIN_MTU) {
			switch (ixa->ixa_use_min_mtu) {
			case IPV6_USE_MIN_MTU_MULTICAST:
				if (ire->ire_type & IRE_MULTICAST)
					pmtu = IPV6_MIN_MTU;
				break;
			case IPV6_USE_MIN_MTU_ALWAYS:
				pmtu = IPV6_MIN_MTU;
				break;
			case IPV6_USE_MIN_MTU_NEVER:
				break;
			}
		} else {
			/* Default is IPV6_USE_MIN_MTU_MULTICAST */
			if (ire->ire_type & IRE_MULTICAST)
				pmtu = IPV6_MIN_MTU;
		}
	}

	/*
	 * After receiving an ICMPv6 "packet too big" message with a
	 * MTU < 1280, and for multirouted IPv6 packets, the IP layer
	 * will insert a 8-byte fragment header in every packet. We compensate
	 * for those cases by returning a smaller path MTU to the ULP.
	 *
	 * In the case of CGTP then ip_output will add a fragment header.
	 * Make sure there is room for it by telling a smaller number
	 * to the transport.
	 *
	 * When IXAF_IPV6_ADDR_FRAGHDR we subtract the frag hdr here
	 * so the ULPs consistently see a iulp_pmtu and ip_get_pmtu()
	 * which is the size of the packets it can send.
	 */
	if (!(ixa->ixa_flags & IXAF_IS_IPV4)) {
		if ((dce->dce_flags & DCEF_TOO_SMALL_PMTU) ||
		    (ire->ire_flags & RTF_MULTIRT) ||
		    (ixa->ixa_flags & IXAF_MULTIRT_MULTICAST)) {
			pmtu -= sizeof (ip6_frag_t);
			ixa->ixa_flags |= IXAF_IPV6_ADD_FRAGHDR;
		}
	}

	return (pmtu);
}

/*
 * Carve "len" bytes out of an mblk chain, consuming any we empty, and duping
 * the final piece where we don't.  Return a pointer to the first mblk in the
 * result, and update the pointer to the next mblk to chew on.  If anything
 * goes wrong (i.e., dupb fails), we waste everything in sight and return a
 * NULL pointer.
 */
mblk_t *
ip_carve_mp(mblk_t **mpp, ssize_t len)
{
	mblk_t	*mp0;
	mblk_t	*mp1;
	mblk_t	*mp2;

	if (!len || !mpp || !(mp0 = *mpp))
		return (NULL);
	/* If we aren't going to consume the first mblk, we need a dup. */
	if (mp0->b_wptr - mp0->b_rptr > len) {
		mp1 = dupb(mp0);
		if (mp1) {
			/* Partition the data between the two mblks. */
			mp1->b_wptr = mp1->b_rptr + len;
			mp0->b_rptr = mp1->b_wptr;
			/*
			 * after adjustments if mblk not consumed is now
			 * unaligned, try to align it. If this fails free
			 * all messages and let upper layer recover.
			 */
			if (!OK_32PTR(mp0->b_rptr)) {
				if (!pullupmsg(mp0, -1)) {
					freemsg(mp0);
					freemsg(mp1);
					*mpp = NULL;
					return (NULL);
				}
			}
		}
		return (mp1);
	}
	/* Eat through as many mblks as we need to get len bytes. */
	len -= mp0->b_wptr - mp0->b_rptr;
	for (mp2 = mp1 = mp0; (mp2 = mp2->b_cont) != 0 && len; mp1 = mp2) {
		if (mp2->b_wptr - mp2->b_rptr > len) {
			/*
			 * We won't consume the entire last mblk.  Like
			 * above, dup and partition it.
			 */
			mp1->b_cont = dupb(mp2);
			mp1 = mp1->b_cont;
			if (!mp1) {
				/*
				 * Trouble.  Rather than go to a lot of
				 * trouble to clean up, we free the messages.
				 * This won't be any worse than losing it on
				 * the wire.
				 */
				freemsg(mp0);
				freemsg(mp2);
				*mpp = NULL;
				return (NULL);
			}
			mp1->b_wptr = mp1->b_rptr + len;
			mp2->b_rptr = mp1->b_wptr;
			/*
			 * after adjustments if mblk not consumed is now
			 * unaligned, try to align it. If this fails free
			 * all messages and let upper layer recover.
			 */
			if (!OK_32PTR(mp2->b_rptr)) {
				if (!pullupmsg(mp2, -1)) {
					freemsg(mp0);
					freemsg(mp2);
					*mpp = NULL;
					return (NULL);
				}
			}
			*mpp = mp2;
			return (mp0);
		}
		/* Decrement len by the amount we just got. */
		len -= mp2->b_wptr - mp2->b_rptr;
	}
	/*
	 * len should be reduced to zero now.  If not our caller has
	 * screwed up.
	 */
	if (len) {
		/* Shouldn't happen! */
		freemsg(mp0);
		*mpp = NULL;
		return (NULL);
	}
	/*
	 * We consumed up to exactly the end of an mblk.  Detach the part
	 * we are returning from the rest of the chain.
	 */
	mp1->b_cont = NULL;
	*mpp = mp2;
	return (mp0);
}

/* The ill stream is being unplumbed. Called from ip_close */
int
ip_modclose(ill_t *ill)
{
	boolean_t success;
	ipsq_t	*ipsq;
	ipif_t	*ipif;
	queue_t	*q = ill->ill_rq;
	ip_stack_t	*ipst = ill->ill_ipst;
	int	i;
	arl_ill_common_t *ai = ill->ill_common;

	/*
	 * The punlink prior to this may have initiated a capability
	 * negotiation. But ipsq_enter will block until that finishes or
	 * times out.
	 */
	success = ipsq_enter(ill, B_FALSE, NEW_OP);

	/*
	 * Open/close/push/pop is guaranteed to be single threaded
	 * per stream by STREAMS. FS guarantees that all references
	 * from top are gone before close is called. So there can't
	 * be another close thread that has set CONDEMNED on this ill.
	 * and cause ipsq_enter to return failure.
	 */
	ASSERT(success);
	ipsq = ill->ill_phyint->phyint_ipsq;

	/*
	 * Mark it condemned. No new reference will be made to this ill.
	 * Lookup functions will return an error. Threads that try to
	 * increment the refcnt must check for ILL_CAN_LOOKUP. This ensures
	 * that the refcnt will drop down to zero.
	 */
	mutex_enter(&ill->ill_lock);
	ill->ill_state_flags |= ILL_CONDEMNED;
	for (ipif = ill->ill_ipif; ipif != NULL;
	    ipif = ipif->ipif_next) {
		ipif->ipif_state_flags |= IPIF_CONDEMNED;
	}
	/*
	 * Wake up anybody waiting to enter the ipsq. ipsq_enter
	 * returns  error if ILL_CONDEMNED is set
	 */
	cv_broadcast(&ill->ill_cv);
	mutex_exit(&ill->ill_lock);

	/*
	 * Send all the deferred DLPI messages downstream which came in
	 * during the small window right before ipsq_enter(). We do this
	 * without waiting for the ACKs because all the ACKs for M_PROTO
	 * messages are ignored in ip_rput() when ILL_CONDEMNED is set.
	 */
	ill_dlpi_send_deferred(ill);

	/*
	 * Shut down fragmentation reassembly.
	 * ill_frag_timer won't start a timer again.
	 * Now cancel any existing timer
	 */
	(void) untimeout(ill->ill_frag_timer_id);
	(void) ill_frag_timeout(ill, 0);

	/*
	 * Call ill_delete to bring down the ipifs, ilms and ill on
	 * this ill. Then wait for the refcnts to drop to zero.
	 * ill_is_freeable checks whether the ill is really quiescent.
	 * Then make sure that threads that are waiting to enter the
	 * ipsq have seen the error returned by ipsq_enter and have
	 * gone away. Then we call ill_delete_tail which does the
	 * DL_UNBIND_REQ with the driver and then qprocsoff.
	 */
	ill_delete(ill);
	mutex_enter(&ill->ill_lock);
	while (!ill_is_freeable(ill))
		cv_wait(&ill->ill_cv, &ill->ill_lock);

	while (ill->ill_waiters)
		cv_wait(&ill->ill_cv, &ill->ill_lock);

	mutex_exit(&ill->ill_lock);

	/*
	 * ill_delete_tail drops reference on ill_ipst, but we need to keep
	 * it held until the end of the function since the cleanup
	 * below needs to be able to use the ip_stack_t.
	 */
	netstack_hold(ipst->ips_netstack);

	/* qprocsoff is done via ill_delete_tail */
	ill_delete_tail(ill);
	/*
	 * synchronously wait for arp stream to unbind. After this, we
	 * cannot get any data packets up from the driver.
	 */
	arp_unbind_complete(ill);
	ASSERT(ill->ill_ipst == NULL);

	/*
	 * Walk through all conns and qenable those that have queued data.
	 * Close synchronization needs this to
	 * be done to ensure that all upper layers blocked
	 * due to flow control to the closing device
	 * get unblocked.
	 */
	ip1dbg(("ip_wsrv: walking\n"));
	for (i = 0; i < TX_FANOUT_SIZE; i++) {
		conn_walk_drain(ipst, &ipst->ips_idl_tx_list[i]);
	}

	/*
	 * ai can be null if this is an IPv6 ill, or if the IPv4
	 * stream is being torn down before ARP was plumbed (e.g.,
	 * /sbin/ifconfig plumbing a stream twice, and encountering
	 * an error
	 */
	if (ai != NULL) {
		ASSERT(!ill->ill_isv6);
		mutex_enter(&ai->ai_lock);
		ai->ai_ill = NULL;
		if (ai->ai_arl == NULL) {
			mutex_destroy(&ai->ai_lock);
			kmem_free(ai, sizeof (*ai));
		} else {
			cv_signal(&ai->ai_ill_unplumb_done);
			mutex_exit(&ai->ai_lock);
		}
	}

	mutex_enter(&ipst->ips_ip_mi_lock);
	mi_close_unlink(&ipst->ips_ip_g_head, (IDP)ill);
	mutex_exit(&ipst->ips_ip_mi_lock);

	/*
	 * credp could be null if the open didn't succeed and ip_modopen
	 * itself calls ip_close.
	 */
	if (ill->ill_credp != NULL)
		crfree(ill->ill_credp);

	mutex_destroy(&ill->ill_saved_ire_lock);
	mutex_destroy(&ill->ill_lock);
	rw_destroy(&ill->ill_mcast_lock);
	mutex_destroy(&ill->ill_mcast_serializer);
	list_destroy(&ill->ill_nce);

	/*
	 * Now we are done with the module close pieces that
	 * need the netstack_t.
	 */
	netstack_rele(ipst->ips_netstack);

	mi_close_free((IDP)ill);
	q->q_ptr = WR(q)->q_ptr = NULL;

	ipsq_exit(ipsq);

	return (0);
}

/*
 * This is called as part of close() for IP, UDP, ICMP, and RTS
 * in order to quiesce the conn.
 */
void
ip_quiesce_conn(conn_t *connp)
{
	boolean_t	drain_cleanup_reqd = B_FALSE;
	boolean_t	conn_ioctl_cleanup_reqd = B_FALSE;
	boolean_t	ilg_cleanup_reqd = B_FALSE;
	ip_stack_t	*ipst;

	ASSERT(!IPCL_IS_TCP(connp));
	ipst = connp->conn_netstack->netstack_ip;

	/*
	 * Mark the conn as closing, and this conn must not be
	 * inserted in future into any list. Eg. conn_drain_insert(),
	 * won't insert this conn into the conn_drain_list.
	 *
	 * conn_idl, and conn_ilg cannot get set henceforth.
	 */
	mutex_enter(&connp->conn_lock);
	ASSERT(!(connp->conn_state_flags & CONN_QUIESCED));
	connp->conn_state_flags |= CONN_CLOSING;
	if (connp->conn_idl != NULL)
		drain_cleanup_reqd = B_TRUE;
	if (connp->conn_oper_pending_ill != NULL)
		conn_ioctl_cleanup_reqd = B_TRUE;
	if (connp->conn_dhcpinit_ill != NULL) {
		ASSERT(connp->conn_dhcpinit_ill->ill_dhcpinit != 0);
		atomic_dec_32(&connp->conn_dhcpinit_ill->ill_dhcpinit);
		ill_set_inputfn(connp->conn_dhcpinit_ill);
		connp->conn_dhcpinit_ill = NULL;
	}
	if (connp->conn_ilg != NULL)
		ilg_cleanup_reqd = B_TRUE;
	mutex_exit(&connp->conn_lock);

	if (conn_ioctl_cleanup_reqd)
		conn_ioctl_cleanup(connp);

	if (is_system_labeled() && connp->conn_anon_port) {
		(void) tsol_mlp_anon(crgetzone(connp->conn_cred),
		    connp->conn_mlp_type, connp->conn_proto,
		    ntohs(connp->conn_lport), B_FALSE);
		connp->conn_anon_port = 0;
	}
	connp->conn_mlp_type = mlptSingle;

	/*
	 * Remove this conn from any fanout list it is on.
	 * and then wait for any threads currently operating
	 * on this endpoint to finish
	 */
	ipcl_hash_remove(connp);

	/*
	 * Remove this conn from the drain list, and do
	 * any other cleanup that may be required.
	 * (Only non-tcp conns may have a non-null conn_idl.
	 * TCP conns are never flow controlled, and
	 * conn_idl will be null)
	 */
	if (drain_cleanup_reqd && connp->conn_idl != NULL) {
		mutex_enter(&connp->conn_idl->idl_lock);
		conn_drain_tail(connp, B_TRUE);
		mutex_exit(&connp->conn_idl->idl_lock);
	}

	if (connp == ipst->ips_ip_g_mrouter)
		(void) ip_mrouter_done(ipst);

	if (ilg_cleanup_reqd)
		ilg_delete_all(connp);

	/*
	 * Now conn refcnt can increase only thru CONN_INC_REF_LOCKED.
	 * callers from write side can't be there now because close
	 * is in progress. The only other caller is ipcl_walk
	 * which checks for the condemned flag.
	 */
	mutex_enter(&connp->conn_lock);
	connp->conn_state_flags |= CONN_CONDEMNED;
	while (connp->conn_ref != 1)
		cv_wait(&connp->conn_cv, &connp->conn_lock);
	connp->conn_state_flags |= CONN_QUIESCED;
	mutex_exit(&connp->conn_lock);
}

/* ARGSUSED */
int
ip_close(queue_t *q, int flags)
{
	conn_t		*connp;

	/*
	 * Call the appropriate delete routine depending on whether this is
	 * a module or device.
	 */
	if (WR(q)->q_next != NULL) {
		/* This is a module close */
		return (ip_modclose((ill_t *)q->q_ptr));
	}

	connp = q->q_ptr;
	ip_quiesce_conn(connp);

	qprocsoff(q);

	/*
	 * Now we are truly single threaded on this stream, and can
	 * delete the things hanging off the connp, and finally the connp.
	 * We removed this connp from the fanout list, it cannot be
	 * accessed thru the fanouts, and we already waited for the
	 * conn_ref to drop to 0. We are already in close, so
	 * there cannot be any other thread from the top. qprocsoff
	 * has completed, and service has completed or won't run in
	 * future.
	 */
	ASSERT(connp->conn_ref == 1);

	inet_minor_free(connp->conn_minor_arena, connp->conn_dev);

	connp->conn_ref--;
	ipcl_conn_destroy(connp);

	q->q_ptr = WR(q)->q_ptr = NULL;
	return (0);
}

/*
 * Wapper around putnext() so that ip_rts_request can merely use
 * conn_recv.
 */
/*ARGSUSED2*/
static void
ip_conn_input(void *arg1, mblk_t *mp, void *arg2, ip_recv_attr_t *ira)
{
	conn_t *connp = (conn_t *)arg1;

	putnext(connp->conn_rq, mp);
}

/* Dummy in case ICMP error delivery is attempted to a /dev/ip instance */
/* ARGSUSED */
static void
ip_conn_input_icmp(void *arg1, mblk_t *mp, void *arg2, ip_recv_attr_t *ira)
{
	freemsg(mp);
}

/*
 * Called when the module is about to be unloaded
 */
void
ip_ddi_destroy(void)
{
	tnet_fini();

	icmp_ddi_g_destroy();
	rts_ddi_g_destroy();
	udp_ddi_g_destroy();
	sctp_ddi_g_destroy();
	tcp_ddi_g_destroy();
	ilb_ddi_g_destroy();
	dce_g_destroy();
	ipsec_policy_g_destroy();
	ipcl_g_destroy();
	ip_net_g_destroy();
	ip_ire_g_fini();
	inet_minor_destroy(ip_minor_arena_sa);
#if defined(_LP64)
	inet_minor_destroy(ip_minor_arena_la);
#endif

#ifdef DEBUG
	list_destroy(&ip_thread_list);
	rw_destroy(&ip_thread_rwlock);
	tsd_destroy(&ip_thread_data);
#endif

	netstack_unregister(NS_IP);
}

/*
 * First step in cleanup.
 */
/* ARGSUSED */
static void
ip_stack_shutdown(netstackid_t stackid, void *arg)
{
	ip_stack_t *ipst = (ip_stack_t *)arg;

#ifdef NS_DEBUG
	printf("ip_stack_shutdown(%p, stack %d)\n", (void *)ipst, stackid);
#endif

	/*
	 * Perform cleanup for special interfaces (loopback and IPMP).
	 */
	ip_interface_cleanup(ipst);

	/*
	 * The *_hook_shutdown()s start the process of notifying any
	 * consumers that things are going away.... nothing is destroyed.
	 */
	ipv4_hook_shutdown(ipst);
	ipv6_hook_shutdown(ipst);
	arp_hook_shutdown(ipst);

	mutex_enter(&ipst->ips_capab_taskq_lock);
	ipst->ips_capab_taskq_quit = B_TRUE;
	cv_signal(&ipst->ips_capab_taskq_cv);
	mutex_exit(&ipst->ips_capab_taskq_lock);
}

/*
 * Free the IP stack instance.
 */
static void
ip_stack_fini(netstackid_t stackid, void *arg)
{
	ip_stack_t *ipst = (ip_stack_t *)arg;
	int ret;

#ifdef NS_DEBUG
	printf("ip_stack_fini(%p, stack %d)\n", (void *)ipst, stackid);
#endif
	/*
	 * At this point, all of the notifications that the events and
	 * protocols are going away have been run, meaning that we can
	 * now set about starting to clean things up.
	 */
	ipobs_fini(ipst);
	ipv4_hook_destroy(ipst);
	ipv6_hook_destroy(ipst);
	arp_hook_destroy(ipst);
	ip_net_destroy(ipst);

	mutex_destroy(&ipst->ips_capab_taskq_lock);
	cv_destroy(&ipst->ips_capab_taskq_cv);

	ipmp_destroy(ipst);
	rw_destroy(&ipst->ips_srcid_lock);

	ip_kstat_fini(stackid, ipst->ips_ip_mibkp);
	ipst->ips_ip_mibkp = NULL;
	icmp_kstat_fini(stackid, ipst->ips_icmp_mibkp);
	ipst->ips_icmp_mibkp = NULL;
	ip_kstat2_fini(stackid, ipst->ips_ip_kstat);
	ipst->ips_ip_kstat = NULL;
	bzero(&ipst->ips_ip_statistics, sizeof (ipst->ips_ip_statistics));
	ip6_kstat_fini(stackid, ipst->ips_ip6_kstat);
	ipst->ips_ip6_kstat = NULL;
	bzero(&ipst->ips_ip6_statistics, sizeof (ipst->ips_ip6_statistics));

	nd_free(&ipst->ips_ip_g_nd);
	kmem_free(ipst->ips_param_arr, sizeof (lcl_param_arr));
	ipst->ips_param_arr = NULL;
	kmem_free(ipst->ips_ndp_arr, sizeof (lcl_ndp_arr));
	ipst->ips_ndp_arr = NULL;

	dce_stack_destroy(ipst);
	ip_mrouter_stack_destroy(ipst);

	mutex_destroy(&ipst->ips_ip_mi_lock);
	rw_destroy(&ipst->ips_ill_g_usesrc_lock);
	rw_destroy(&ipst->ips_ip_g_nd_lock);

	ret = untimeout(ipst->ips_igmp_timeout_id);
	if (ret == -1) {
		ASSERT(ipst->ips_igmp_timeout_id == 0);
	} else {
		ASSERT(ipst->ips_igmp_timeout_id != 0);
		ipst->ips_igmp_timeout_id = 0;
	}
	ret = untimeout(ipst->ips_igmp_slowtimeout_id);
	if (ret == -1) {
		ASSERT(ipst->ips_igmp_slowtimeout_id == 0);
	} else {
		ASSERT(ipst->ips_igmp_slowtimeout_id != 0);
		ipst->ips_igmp_slowtimeout_id = 0;
	}
	ret = untimeout(ipst->ips_mld_timeout_id);
	if (ret == -1) {
		ASSERT(ipst->ips_mld_timeout_id == 0);
	} else {
		ASSERT(ipst->ips_mld_timeout_id != 0);
		ipst->ips_mld_timeout_id = 0;
	}
	ret = untimeout(ipst->ips_mld_slowtimeout_id);
	if (ret == -1) {
		ASSERT(ipst->ips_mld_slowtimeout_id == 0);
	} else {
		ASSERT(ipst->ips_mld_slowtimeout_id != 0);
		ipst->ips_mld_slowtimeout_id = 0;
	}

	mutex_destroy(&ipst->ips_igmp_timer_lock);
	mutex_destroy(&ipst->ips_mld_timer_lock);
	mutex_destroy(&ipst->ips_igmp_slowtimeout_lock);
	mutex_destroy(&ipst->ips_mld_slowtimeout_lock);
	mutex_destroy(&ipst->ips_ip_addr_avail_lock);
	rw_destroy(&ipst->ips_ill_g_lock);

	ip_ire_fini(ipst);
	ip6_asp_free(ipst);
	conn_drain_fini(ipst);
	ipcl_destroy(ipst);

	mutex_destroy(&ipst->ips_ndp4->ndp_g_lock);
	mutex_destroy(&ipst->ips_ndp6->ndp_g_lock);
	kmem_free(ipst->ips_ndp4, sizeof (ndp_g_t));
	ipst->ips_ndp4 = NULL;
	kmem_free(ipst->ips_ndp6, sizeof (ndp_g_t));
	ipst->ips_ndp6 = NULL;

	if (ipst->ips_loopback_ksp != NULL) {
		kstat_delete_netstack(ipst->ips_loopback_ksp, stackid);
		ipst->ips_loopback_ksp = NULL;
	}

	kmem_free(ipst->ips_phyint_g_list, sizeof (phyint_list_t));
	ipst->ips_phyint_g_list = NULL;
	kmem_free(ipst->ips_ill_g_heads, sizeof (ill_g_head_t) * MAX_G_HEADS);
	ipst->ips_ill_g_heads = NULL;

	ldi_ident_release(ipst->ips_ldi_ident);
	kmem_free(ipst, sizeof (*ipst));
}

/*
 * This function is called from the TSD destructor, and is used to debug
 * reference count issues in IP. See block comment in <inet/ip_if.h> for
 * details.
 */
static void
ip_thread_exit(void *phash)
{
	th_hash_t *thh = phash;

	rw_enter(&ip_thread_rwlock, RW_WRITER);
	list_remove(&ip_thread_list, thh);
	rw_exit(&ip_thread_rwlock);
	mod_hash_destroy_hash(thh->thh_hash);
	kmem_free(thh, sizeof (*thh));
}

/*
 * Called when the IP kernel module is loaded into the kernel
 */
void
ip_ddi_init(void)
{
	ip_squeue_flag = ip_squeue_switch(ip_squeue_enter);

	/*
	 * For IP and TCP the minor numbers should start from 2 since we have 4
	 * initial devices: ip, ip6, tcp, tcp6.
	 */
	/*
	 * If this is a 64-bit kernel, then create two separate arenas -
	 * one for TLIs in the range of INET_MIN_DEV+2 through 2^^18-1, and the
	 * other for socket apps in the range 2^^18 through 2^^32-1.
	 */
	ip_minor_arena_la = NULL;
	ip_minor_arena_sa = NULL;
#if defined(_LP64)
	if ((ip_minor_arena_sa = inet_minor_create("ip_minor_arena_sa",
	    INET_MIN_DEV + 2, MAXMIN32, KM_SLEEP)) == NULL) {
		cmn_err(CE_PANIC,
		    "ip_ddi_init: ip_minor_arena_sa creation failed\n");
	}
	if ((ip_minor_arena_la = inet_minor_create("ip_minor_arena_la",
	    MAXMIN32 + 1, MAXMIN64, KM_SLEEP)) == NULL) {
		cmn_err(CE_PANIC,
		    "ip_ddi_init: ip_minor_arena_la creation failed\n");
	}
#else
	if ((ip_minor_arena_sa = inet_minor_create("ip_minor_arena_sa",
	    INET_MIN_DEV + 2, MAXMIN, KM_SLEEP)) == NULL) {
		cmn_err(CE_PANIC,
		    "ip_ddi_init: ip_minor_arena_sa creation failed\n");
	}
#endif
	ip_poll_normal_ticks = MSEC_TO_TICK_ROUNDUP(ip_poll_normal_ms);

	ipcl_g_init();
	ip_ire_g_init();
	ip_net_g_init();

#ifdef DEBUG
	tsd_create(&ip_thread_data, ip_thread_exit);
	rw_init(&ip_thread_rwlock, NULL, RW_DEFAULT, NULL);
	list_create(&ip_thread_list, sizeof (th_hash_t),
	    offsetof(th_hash_t, thh_link));
#endif
	ipsec_policy_g_init();
	tcp_ddi_g_init();
	sctp_ddi_g_init();
	dce_g_init();

	/*
	 * We want to be informed each time a stack is created or
	 * destroyed in the kernel, so we can maintain the
	 * set of udp_stack_t's.
	 */
	netstack_register(NS_IP, ip_stack_init, ip_stack_shutdown,
	    ip_stack_fini);

	tnet_init();

	udp_ddi_g_init();
	rts_ddi_g_init();
	icmp_ddi_g_init();
	ilb_ddi_g_init();
}

/*
 * Initialize the IP stack instance.
 */
static void *
ip_stack_init(netstackid_t stackid, netstack_t *ns)
{
	ip_stack_t	*ipst;
	ipparam_t	*pa;
	ipndp_t		*na;
	major_t		major;

#ifdef NS_DEBUG
	printf("ip_stack_init(stack %d)\n", stackid);
#endif

	ipst = (ip_stack_t *)kmem_zalloc(sizeof (*ipst), KM_SLEEP);
	ipst->ips_netstack = ns;

	ipst->ips_ill_g_heads = kmem_zalloc(sizeof (ill_g_head_t) * MAX_G_HEADS,
	    KM_SLEEP);
	ipst->ips_phyint_g_list = kmem_zalloc(sizeof (phyint_list_t),
	    KM_SLEEP);
	ipst->ips_ndp4 = kmem_zalloc(sizeof (ndp_g_t), KM_SLEEP);
	ipst->ips_ndp6 = kmem_zalloc(sizeof (ndp_g_t), KM_SLEEP);
	mutex_init(&ipst->ips_ndp4->ndp_g_lock, NULL, MUTEX_DEFAULT, NULL);
	mutex_init(&ipst->ips_ndp6->ndp_g_lock, NULL, MUTEX_DEFAULT, NULL);

	rw_init(&ipst->ips_ip_g_nd_lock, NULL, RW_DEFAULT, NULL);
	mutex_init(&ipst->ips_igmp_timer_lock, NULL, MUTEX_DEFAULT, NULL);
	ipst->ips_igmp_deferred_next = INFINITY;
	mutex_init(&ipst->ips_mld_timer_lock, NULL, MUTEX_DEFAULT, NULL);
	ipst->ips_mld_deferred_next = INFINITY;
	mutex_init(&ipst->ips_igmp_slowtimeout_lock, NULL, MUTEX_DEFAULT, NULL);
	mutex_init(&ipst->ips_mld_slowtimeout_lock, NULL, MUTEX_DEFAULT, NULL);
	mutex_init(&ipst->ips_ip_mi_lock, NULL, MUTEX_DEFAULT, NULL);
	mutex_init(&ipst->ips_ip_addr_avail_lock, NULL, MUTEX_DEFAULT, NULL);
	rw_init(&ipst->ips_ill_g_lock, NULL, RW_DEFAULT, NULL);
	rw_init(&ipst->ips_ill_g_usesrc_lock, NULL, RW_DEFAULT, NULL);

	ipcl_init(ipst);
	ip_ire_init(ipst);
	ip6_asp_init(ipst);
	ipif_init(ipst);
	conn_drain_init(ipst);
	ip_mrouter_stack_init(ipst);
	dce_stack_init(ipst);

	ipst->ips_ip_g_frag_timeout = IP_FRAG_TIMEOUT;
	ipst->ips_ip_g_frag_timo_ms = IP_FRAG_TIMEOUT * 1000;
	ipst->ips_ipv6_frag_timeout = IPV6_FRAG_TIMEOUT;
	ipst->ips_ipv6_frag_timo_ms = IPV6_FRAG_TIMEOUT * 1000;

	ipst->ips_ip_multirt_log_interval = 1000;

	ipst->ips_ip_g_forward = IP_FORWARD_DEFAULT;
	ipst->ips_ipv6_forward = IP_FORWARD_DEFAULT;
	ipst->ips_ill_index = 1;

	ipst->ips_saved_ip_g_forward = -1;
	ipst->ips_reg_vif_num = ALL_VIFS; 	/* Index to Register vif */

	pa = (ipparam_t *)kmem_alloc(sizeof (lcl_param_arr), KM_SLEEP);
	ipst->ips_param_arr = pa;
	bcopy(lcl_param_arr, ipst->ips_param_arr, sizeof (lcl_param_arr));

	na = (ipndp_t *)kmem_alloc(sizeof (lcl_ndp_arr), KM_SLEEP);
	ipst->ips_ndp_arr = na;
	bcopy(lcl_ndp_arr, ipst->ips_ndp_arr, sizeof (lcl_ndp_arr));
	ipst->ips_ndp_arr[IPNDP_IP_FORWARDING_OFFSET].ip_ndp_data =
	    (caddr_t)&ipst->ips_ip_g_forward;
	ipst->ips_ndp_arr[IPNDP_IP6_FORWARDING_OFFSET].ip_ndp_data =
	    (caddr_t)&ipst->ips_ipv6_forward;
	ASSERT(strcmp(ipst->ips_ndp_arr[IPNDP_CGTP_FILTER_OFFSET].ip_ndp_name,
	    "ip_cgtp_filter") == 0);
	ipst->ips_ndp_arr[IPNDP_CGTP_FILTER_OFFSET].ip_ndp_data =
	    (caddr_t)&ipst->ips_ip_cgtp_filter;

	(void) ip_param_register(&ipst->ips_ip_g_nd,
	    ipst->ips_param_arr, A_CNT(lcl_param_arr),
	    ipst->ips_ndp_arr, A_CNT(lcl_ndp_arr));

	ipst->ips_ip_mibkp = ip_kstat_init(stackid, ipst);
	ipst->ips_icmp_mibkp = icmp_kstat_init(stackid);
	ipst->ips_ip_kstat = ip_kstat2_init(stackid, &ipst->ips_ip_statistics);
	ipst->ips_ip6_kstat =
	    ip6_kstat_init(stackid, &ipst->ips_ip6_statistics);

	ipst->ips_ip_src_id = 1;
	rw_init(&ipst->ips_srcid_lock, NULL, RW_DEFAULT, NULL);

	ipst->ips_src_generation = SRC_GENERATION_INITIAL;

	ip_net_init(ipst, ns);
	ipv4_hook_init(ipst);
	ipv6_hook_init(ipst);
	arp_hook_init(ipst);
	ipmp_init(ipst);
	ipobs_init(ipst);

	/*
	 * Create the taskq dispatcher thread and initialize related stuff.
	 */
	ipst->ips_capab_taskq_thread = thread_create(NULL, 0,
	    ill_taskq_dispatch, ipst, 0, &p0, TS_RUN, minclsyspri);
	mutex_init(&ipst->ips_capab_taskq_lock, NULL, MUTEX_DEFAULT, NULL);
	cv_init(&ipst->ips_capab_taskq_cv, NULL, CV_DEFAULT, NULL);

	major = mod_name_to_major(INET_NAME);
	(void) ldi_ident_from_major(major, &ipst->ips_ldi_ident);
	return (ipst);
}

/*
 * Allocate and initialize a DLPI template of the specified length.  (May be
 * called as writer.)
 */
mblk_t *
ip_dlpi_alloc(size_t len, t_uscalar_t prim)
{
	mblk_t	*mp;

	mp = allocb(len, BPRI_MED);
	if (!mp)
		return (NULL);

	/*
	 * DLPIv2 says that DL_INFO_REQ and DL_TOKEN_REQ (the latter
	 * of which we don't seem to use) are sent with M_PCPROTO, and
	 * that other DLPI are M_PROTO.
	 */
	if (prim == DL_INFO_REQ) {
		mp->b_datap->db_type = M_PCPROTO;
	} else {
		mp->b_datap->db_type = M_PROTO;
	}

	mp->b_wptr = mp->b_rptr + len;
	bzero(mp->b_rptr, len);
	((dl_unitdata_req_t *)mp->b_rptr)->dl_primitive = prim;
	return (mp);
}

/*
 * Allocate and initialize a DLPI notification.  (May be called as writer.)
 */
mblk_t *
ip_dlnotify_alloc(uint_t notification, uint_t data)
{
	dl_notify_ind_t	*notifyp;
	mblk_t		*mp;

	if ((mp = ip_dlpi_alloc(DL_NOTIFY_IND_SIZE, DL_NOTIFY_IND)) == NULL)
		return (NULL);

	notifyp = (dl_notify_ind_t *)mp->b_rptr;
	notifyp->dl_notification = notification;
	notifyp->dl_data = data;
	return (mp);
}

/*
 * Debug formatting routine.  Returns a character string representation of the
 * addr in buf, of the form xxx.xxx.xxx.xxx.  This routine takes the address
 * in the form of a ipaddr_t and calls ip_dot_saddr with a pointer.
 *
 * Once the ndd table-printing interfaces are removed, this can be changed to
 * standard dotted-decimal form.
 */
char *
ip_dot_addr(ipaddr_t addr, char *buf)
{
	uint8_t *ap = (uint8_t *)&addr;

	(void) mi_sprintf(buf, "%03d.%03d.%03d.%03d",
	    ap[0] & 0xFF, ap[1] & 0xFF, ap[2] & 0xFF, ap[3] & 0xFF);
	return (buf);
}

/*
 * Write the given MAC address as a printable string in the usual colon-
 * separated format.
 */
const char *
mac_colon_addr(const uint8_t *addr, size_t alen, char *buf, size_t buflen)
{
	char *bp;

	if (alen == 0 || buflen < 4)
		return ("?");
	bp = buf;
	for (;;) {
		/*
		 * If there are more MAC address bytes available, but we won't
		 * have any room to print them, then add "..." to the string
		 * instead.  See below for the 'magic number' explanation.
		 */
		if ((alen == 2 && buflen < 6) || (alen > 2 && buflen < 7)) {
			(void) strcpy(bp, "...");
			break;
		}
		(void) sprintf(bp, "%02x", *addr++);
		bp += 2;
		if (--alen == 0)
			break;
		*bp++ = ':';
		buflen -= 3;
		/*
		 * At this point, based on the first 'if' statement above,
		 * either alen == 1 and buflen >= 3, or alen > 1 and
		 * buflen >= 4.  The first case leaves room for the final "xx"
		 * number and trailing NUL byte.  The second leaves room for at
		 * least "...".  Thus the apparently 'magic' numbers chosen for
		 * that statement.
		 */
	}
	return (buf);
}

/*
 * Called when it is conceptually a ULP that would sent the packet
 * e.g., port unreachable and protocol unreachable. Check that the packet
 * would have passed the IPsec global policy before sending the error.
 *
 * Send an ICMP error after patching up the packet appropriately.
 * Uses ip_drop_input and bumps the appropriate MIB.
 */
void
ip_fanout_send_icmp_v4(mblk_t *mp, uint_t icmp_type, uint_t icmp_code,
    ip_recv_attr_t *ira)
{
	ipha_t		*ipha;
	boolean_t	secure;
	ill_t		*ill = ira->ira_ill;
	ip_stack_t	*ipst = ill->ill_ipst;
	netstack_t	*ns = ipst->ips_netstack;
	ipsec_stack_t	*ipss = ns->netstack_ipsec;

	secure = ira->ira_flags & IRAF_IPSEC_SECURE;

	/*
	 * We are generating an icmp error for some inbound packet.
	 * Called from all ip_fanout_(udp, tcp, proto) functions.
	 * Before we generate an error, check with global policy
	 * to see whether this is allowed to enter the system. As
	 * there is no "conn", we are checking with global policy.
	 */
	ipha = (ipha_t *)mp->b_rptr;
	if (secure || ipss->ipsec_inbound_v4_policy_present) {
		mp = ipsec_check_global_policy(mp, NULL, ipha, NULL, ira, ns);
		if (mp == NULL)
			return;
	}

	/* We never send errors for protocols that we do implement */
	if (ira->ira_protocol == IPPROTO_ICMP ||
	    ira->ira_protocol == IPPROTO_IGMP) {
		BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
		ip_drop_input("ip_fanout_send_icmp_v4", mp, ill);
		freemsg(mp);
		return;
	}
	/*
	 * Have to correct checksum since
	 * the packet might have been
	 * fragmented and the reassembly code in ip_rput
	 * does not restore the IP checksum.
	 */
	ipha->ipha_hdr_checksum = 0;
	ipha->ipha_hdr_checksum = ip_csum_hdr(ipha);

	switch (icmp_type) {
	case ICMP_DEST_UNREACHABLE:
		switch (icmp_code) {
		case ICMP_PROTOCOL_UNREACHABLE:
			BUMP_MIB(ill->ill_ip_mib, ipIfStatsInUnknownProtos);
			ip_drop_input("ipIfStatsInUnknownProtos", mp, ill);
			break;
		case ICMP_PORT_UNREACHABLE:
			BUMP_MIB(ill->ill_ip_mib, udpIfStatsNoPorts);
			ip_drop_input("ipIfStatsNoPorts", mp, ill);
			break;
		}

		icmp_unreachable(mp, icmp_code, ira);
		break;
	default:
#ifdef DEBUG
		panic("ip_fanout_send_icmp_v4: wrong type");
		/*NOTREACHED*/
#else
		freemsg(mp);
		break;
#endif
	}
}

/*
 * Used to send an ICMP error message when a packet is received for
 * a protocol that is not supported. The mblk passed as argument
 * is consumed by this function.
 */
void
ip_proto_not_sup(mblk_t *mp, ip_recv_attr_t *ira)
{
	ipha_t		*ipha;

	ipha = (ipha_t *)mp->b_rptr;
	if (ira->ira_flags & IRAF_IS_IPV4) {
		ASSERT(IPH_HDR_VERSION(ipha) == IP_VERSION);
		ip_fanout_send_icmp_v4(mp, ICMP_DEST_UNREACHABLE,
		    ICMP_PROTOCOL_UNREACHABLE, ira);
	} else {
		ASSERT(IPH_HDR_VERSION(ipha) == IPV6_VERSION);
		ip_fanout_send_icmp_v6(mp, ICMP6_PARAM_PROB,
		    ICMP6_PARAMPROB_NEXTHEADER, ira);
	}
}

/*
 * Deliver a rawip packet to the given conn, possibly applying ipsec policy.
 * Handles IPv4 and IPv6.
 * We are responsible for disposing of mp, such as by freemsg() or putnext()
 * Caller is responsible for dropping references to the conn.
 */
void
ip_fanout_proto_conn(conn_t *connp, mblk_t *mp, ipha_t *ipha, ip6_t *ip6h,
    ip_recv_attr_t *ira)
{
	ill_t		*ill = ira->ira_ill;
	ip_stack_t	*ipst = ill->ill_ipst;
	ipsec_stack_t	*ipss = ipst->ips_netstack->netstack_ipsec;
	boolean_t	secure;
	uint_t		protocol = ira->ira_protocol;
	iaflags_t	iraflags = ira->ira_flags;
	queue_t		*rq;

	secure = iraflags & IRAF_IPSEC_SECURE;

	rq = connp->conn_rq;
	if (IPCL_IS_NONSTR(connp) ? connp->conn_flow_cntrld : !canputnext(rq)) {
		switch (protocol) {
		case IPPROTO_ICMPV6:
			BUMP_MIB(ill->ill_icmp6_mib, ipv6IfIcmpInOverflows);
			break;
		case IPPROTO_ICMP:
			BUMP_MIB(&ipst->ips_icmp_mib, icmpInOverflows);
			break;
		default:
			BUMP_MIB(ill->ill_ip_mib, rawipIfStatsInOverflows);
			break;
		}
		freemsg(mp);
		return;
	}

	ASSERT(!(IPCL_IS_IPTUN(connp)));

	if (((iraflags & IRAF_IS_IPV4) ?
	    CONN_INBOUND_POLICY_PRESENT(connp, ipss) :
	    CONN_INBOUND_POLICY_PRESENT_V6(connp, ipss)) ||
	    secure) {
		mp = ipsec_check_inbound_policy(mp, connp, ipha,
		    ip6h, ira);
		if (mp == NULL) {
			BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
			/* Note that mp is NULL */
			ip_drop_input("ipIfStatsInDiscards", mp, ill);
			return;
		}
	}

	if (iraflags & IRAF_ICMP_ERROR) {
		(connp->conn_recvicmp)(connp, mp, NULL, ira);
	} else {
		ill_t *rill = ira->ira_rill;

		BUMP_MIB(ill->ill_ip_mib, ipIfStatsHCInDelivers);
		ira->ira_ill = ira->ira_rill = NULL;
		/* Send it upstream */
		(connp->conn_recv)(connp, mp, NULL, ira);
		ira->ira_ill = ill;
		ira->ira_rill = rill;
	}
}

/*
 * Handle protocols with which IP is less intimate.  There
 * can be more than one stream bound to a particular
 * protocol.  When this is the case, normally each one gets a copy
 * of any incoming packets.
 *
 * IPsec NOTE :
 *
 * Don't allow a secure packet going up a non-secure connection.
 * We don't allow this because
 *
 * 1) Reply might go out in clear which will be dropped at
 *    the sending side.
 * 2) If the reply goes out in clear it will give the
 *    adversary enough information for getting the key in
 *    most of the cases.
 *
 * Moreover getting a secure packet when we expect clear
 * implies that SA's were added without checking for
 * policy on both ends. This should not happen once ISAKMP
 * is used to negotiate SAs as SAs will be added only after
 * verifying the policy.
 *
 * Zones notes:
 * Earlier in ip_input on a system with multiple shared-IP zones we
 * duplicate the multicast and broadcast packets and send them up
 * with each explicit zoneid that exists on that ill.
 * This means that here we can match the zoneid with SO_ALLZONES being special.
 */
void
ip_fanout_proto_v4(mblk_t *mp, ipha_t *ipha, ip_recv_attr_t *ira)
{
	mblk_t		*mp1;
	ipaddr_t	laddr;
	conn_t		*connp, *first_connp, *next_connp;
	connf_t		*connfp;
	ill_t		*ill = ira->ira_ill;
	ip_stack_t	*ipst = ill->ill_ipst;

	laddr = ipha->ipha_dst;

	connfp = &ipst->ips_ipcl_proto_fanout_v4[ira->ira_protocol];
	mutex_enter(&connfp->connf_lock);
	connp = connfp->connf_head;
	for (connp = connfp->connf_head; connp != NULL;
	    connp = connp->conn_next) {
		/* Note: IPCL_PROTO_MATCH includes conn_wantpacket */
		if (IPCL_PROTO_MATCH(connp, ira, ipha) &&
		    (!(ira->ira_flags & IRAF_SYSTEM_LABELED) ||
		    tsol_receive_local(mp, &laddr, IPV4_VERSION, ira, connp))) {
			break;
		}
	}

	if (connp == NULL) {
		/*
		 * No one bound to these addresses.  Is
		 * there a client that wants all
		 * unclaimed datagrams?
		 */
		mutex_exit(&connfp->connf_lock);
		ip_fanout_send_icmp_v4(mp, ICMP_DEST_UNREACHABLE,
		    ICMP_PROTOCOL_UNREACHABLE, ira);
		return;
	}

	ASSERT(IPCL_IS_NONSTR(connp) || connp->conn_rq != NULL);

	CONN_INC_REF(connp);
	first_connp = connp;
	connp = connp->conn_next;

	for (;;) {
		while (connp != NULL) {
			/* Note: IPCL_PROTO_MATCH includes conn_wantpacket */
			if (IPCL_PROTO_MATCH(connp, ira, ipha) &&
			    (!(ira->ira_flags & IRAF_SYSTEM_LABELED) ||
			    tsol_receive_local(mp, &laddr, IPV4_VERSION,
			    ira, connp)))
				break;
			connp = connp->conn_next;
		}

		if (connp == NULL) {
			/* No more interested clients */
			connp = first_connp;
			break;
		}
		if (((mp1 = dupmsg(mp)) == NULL) &&
		    ((mp1 = copymsg(mp)) == NULL)) {
			/* Memory allocation failed */
			BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
			ip_drop_input("ipIfStatsInDiscards", mp, ill);
			connp = first_connp;
			break;
		}

		CONN_INC_REF(connp);
		mutex_exit(&connfp->connf_lock);

		ip_fanout_proto_conn(connp, mp1, (ipha_t *)mp1->b_rptr, NULL,
		    ira);

		mutex_enter(&connfp->connf_lock);
		/* Follow the next pointer before releasing the conn. */
		next_connp = connp->conn_next;
		CONN_DEC_REF(connp);
		connp = next_connp;
	}

	/* Last one.  Send it upstream. */
	mutex_exit(&connfp->connf_lock);

	ip_fanout_proto_conn(connp, mp, ipha, NULL, ira);

	CONN_DEC_REF(connp);
}

/*
 * If we have a IPsec NAT-Traversal packet, strip the zero-SPI or
 * pass it along to ESP if the SPI is non-zero.  Returns the mblk if the mblk
 * is not consumed.
 *
 * One of three things can happen, all of which affect the passed-in mblk:
 *
 * 1.) The packet is stock UDP and gets its zero-SPI stripped.  Return mblk..
 *
 * 2.) The packet is ESP-in-UDP, gets transformed into an equivalent
 *     ESP packet, and is passed along to ESP for consumption.  Return NULL.
 *
 * 3.) The packet is an ESP-in-UDP Keepalive.  Drop it and return NULL.
 */
mblk_t *
zero_spi_check(mblk_t *mp, ip_recv_attr_t *ira)
{
	int shift, plen, iph_len;
	ipha_t *ipha;
	udpha_t *udpha;
	uint32_t *spi;
	uint32_t esp_ports;
	uint8_t *orptr;
	ip_stack_t	*ipst = ira->ira_ill->ill_ipst;
	ipsec_stack_t	*ipss = ipst->ips_netstack->netstack_ipsec;

	ipha = (ipha_t *)mp->b_rptr;
	iph_len = ira->ira_ip_hdr_length;
	plen = ira->ira_pktlen;

	if (plen - iph_len - sizeof (udpha_t) < sizeof (uint32_t)) {
		/*
		 * Most likely a keepalive for the benefit of an intervening
		 * NAT.  These aren't for us, per se, so drop it.
		 *
		 * RFC 3947/8 doesn't say for sure what to do for 2-3
		 * byte packets (keepalives are 1-byte), but we'll drop them
		 * also.
		 */
		ip_drop_packet(mp, B_TRUE, ira->ira_ill,
		    DROPPER(ipss, ipds_esp_nat_t_ka), &ipss->ipsec_dropper);
		return (NULL);
	}

	if (MBLKL(mp) < iph_len + sizeof (udpha_t) + sizeof (*spi)) {
		/* might as well pull it all up - it might be ESP. */
		if (!pullupmsg(mp, -1)) {
			ip_drop_packet(mp, B_TRUE, ira->ira_ill,
			    DROPPER(ipss, ipds_esp_nomem),
			    &ipss->ipsec_dropper);
			return (NULL);
		}

		ipha = (ipha_t *)mp->b_rptr;
	}
	spi = (uint32_t *)(mp->b_rptr + iph_len + sizeof (udpha_t));
	if (*spi == 0) {
		/* UDP packet - remove 0-spi. */
		shift = sizeof (uint32_t);
	} else {
		/* ESP-in-UDP packet - reduce to ESP. */
		ipha->ipha_protocol = IPPROTO_ESP;
		shift = sizeof (udpha_t);
	}

	/* Fix IP header */
	ira->ira_pktlen = (plen - shift);
	ipha->ipha_length = htons(ira->ira_pktlen);
	ipha->ipha_hdr_checksum = 0;

	orptr = mp->b_rptr;
	mp->b_rptr += shift;

	udpha = (udpha_t *)(orptr + iph_len);
	if (*spi == 0) {
		ASSERT((uint8_t *)ipha == orptr);
		udpha->uha_length = htons(plen - shift - iph_len);
		iph_len += sizeof (udpha_t);	/* For the call to ovbcopy(). */
		esp_ports = 0;
	} else {
		esp_ports = *((uint32_t *)udpha);
		ASSERT(esp_ports != 0);
	}
	ovbcopy(orptr, orptr + shift, iph_len);
	if (esp_ports != 0) /* Punt up for ESP processing. */ {
		ipha = (ipha_t *)(orptr + shift);

		ira->ira_flags |= IRAF_ESP_UDP_PORTS;
		ira->ira_esp_udp_ports = esp_ports;
		ip_fanout_v4(mp, ipha, ira);
		return (NULL);
	}
	return (mp);
}

/*
 * Deliver a udp packet to the given conn, possibly applying ipsec policy.
 * Handles IPv4 and IPv6.
 * We are responsible for disposing of mp, such as by freemsg() or putnext()
 * Caller is responsible for dropping references to the conn.
 */
void
ip_fanout_udp_conn(conn_t *connp, mblk_t *mp, ipha_t *ipha, ip6_t *ip6h,
    ip_recv_attr_t *ira)
{
	ill_t		*ill = ira->ira_ill;
	ip_stack_t	*ipst = ill->ill_ipst;
	ipsec_stack_t	*ipss = ipst->ips_netstack->netstack_ipsec;
	boolean_t	secure;
	iaflags_t	iraflags = ira->ira_flags;

	secure = iraflags & IRAF_IPSEC_SECURE;

	if (IPCL_IS_NONSTR(connp) ? connp->conn_flow_cntrld :
	    !canputnext(connp->conn_rq)) {
		BUMP_MIB(ill->ill_ip_mib, udpIfStatsInOverflows);
		freemsg(mp);
		return;
	}

	if (((iraflags & IRAF_IS_IPV4) ?
	    CONN_INBOUND_POLICY_PRESENT(connp, ipss) :
	    CONN_INBOUND_POLICY_PRESENT_V6(connp, ipss)) ||
	    secure) {
		mp = ipsec_check_inbound_policy(mp, connp, ipha,
		    ip6h, ira);
		if (mp == NULL) {
			BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
			/* Note that mp is NULL */
			ip_drop_input("ipIfStatsInDiscards", mp, ill);
			return;
		}
	}

	/*
	 * Since this code is not used for UDP unicast we don't need a NAT_T
	 * check. Only ip_fanout_v4 has that check.
	 */
	if (ira->ira_flags & IRAF_ICMP_ERROR) {
		(connp->conn_recvicmp)(connp, mp, NULL, ira);
	} else {
		ill_t *rill = ira->ira_rill;

		BUMP_MIB(ill->ill_ip_mib, ipIfStatsHCInDelivers);
		ira->ira_ill = ira->ira_rill = NULL;
		/* Send it upstream */
		(connp->conn_recv)(connp, mp, NULL, ira);
		ira->ira_ill = ill;
		ira->ira_rill = rill;
	}
}

/*
 * Fanout for UDP packets that are multicast or broadcast, and ICMP errors.
 * (Unicast fanout is handled in ip_input_v4.)
 *
 * If SO_REUSEADDR is set all multicast and broadcast packets
 * will be delivered to all conns bound to the same port.
 *
 * If there is at least one matching AF_INET receiver, then we will
 * ignore any AF_INET6 receivers.
 * In the special case where an AF_INET socket binds to 0.0.0.0/<port> and an
 * AF_INET6 socket binds to ::/<port>, only the AF_INET socket receives the IPv4
 * packets.
 *
 * Zones notes:
 * Earlier in ip_input on a system with multiple shared-IP zones we
 * duplicate the multicast and broadcast packets and send them up
 * with each explicit zoneid that exists on that ill.
 * This means that here we can match the zoneid with SO_ALLZONES being special.
 */
void
ip_fanout_udp_multi_v4(mblk_t *mp, ipha_t *ipha, uint16_t lport, uint16_t fport,
    ip_recv_attr_t *ira)
{
	ipaddr_t	laddr;
	in6_addr_t	v6faddr;
	conn_t		*connp;
	connf_t		*connfp;
	ipaddr_t	faddr;
	ill_t		*ill = ira->ira_ill;
	ip_stack_t	*ipst = ill->ill_ipst;

	ASSERT(ira->ira_flags & (IRAF_MULTIBROADCAST|IRAF_ICMP_ERROR));

	laddr = ipha->ipha_dst;
	faddr = ipha->ipha_src;

	connfp = &ipst->ips_ipcl_udp_fanout[IPCL_UDP_HASH(lport, ipst)];
	mutex_enter(&connfp->connf_lock);
	connp = connfp->connf_head;

	/*
	 * If SO_REUSEADDR has been set on the first we send the
	 * packet to all clients that have joined the group and
	 * match the port.
	 */
	while (connp != NULL) {
		if ((IPCL_UDP_MATCH(connp, lport, laddr, fport, faddr)) &&
		    conn_wantpacket(connp, ira, ipha) &&
		    (!(ira->ira_flags & IRAF_SYSTEM_LABELED) ||
		    tsol_receive_local(mp, &laddr, IPV4_VERSION, ira, connp)))
			break;
		connp = connp->conn_next;
	}

	if (connp == NULL)
		goto notfound;

	CONN_INC_REF(connp);

	if (connp->conn_reuseaddr) {
		conn_t		*first_connp = connp;
		conn_t		*next_connp;
		mblk_t		*mp1;

		connp = connp->conn_next;
		for (;;) {
			while (connp != NULL) {
				if (IPCL_UDP_MATCH(connp, lport, laddr,
				    fport, faddr) &&
				    conn_wantpacket(connp, ira, ipha) &&
				    (!(ira->ira_flags & IRAF_SYSTEM_LABELED) ||
				    tsol_receive_local(mp, &laddr, IPV4_VERSION,
				    ira, connp)))
					break;
				connp = connp->conn_next;
			}
			if (connp == NULL) {
				/* No more interested clients */
				connp = first_connp;
				break;
			}
			if (((mp1 = dupmsg(mp)) == NULL) &&
			    ((mp1 = copymsg(mp)) == NULL)) {
				/* Memory allocation failed */
				BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
				ip_drop_input("ipIfStatsInDiscards", mp, ill);
				connp = first_connp;
				break;
			}
			CONN_INC_REF(connp);
			mutex_exit(&connfp->connf_lock);

			IP_STAT(ipst, ip_udp_fanmb);
			ip_fanout_udp_conn(connp, mp1, (ipha_t *)mp1->b_rptr,
			    NULL, ira);
			mutex_enter(&connfp->connf_lock);
			/* Follow the next pointer before releasing the conn */
			next_connp = connp->conn_next;
			CONN_DEC_REF(connp);
			connp = next_connp;
		}
	}

	/* Last one.  Send it upstream. */
	mutex_exit(&connfp->connf_lock);
	IP_STAT(ipst, ip_udp_fanmb);
	ip_fanout_udp_conn(connp, mp, ipha, NULL, ira);
	CONN_DEC_REF(connp);
	return;

notfound:
	mutex_exit(&connfp->connf_lock);
	/*
	 * IPv6 endpoints bound to multicast IPv4-mapped addresses
	 * have already been matched above, since they live in the IPv4
	 * fanout tables. This implies we only need to
	 * check for IPv6 in6addr_any endpoints here.
	 * Thus we compare using ipv6_all_zeros instead of the destination
	 * address, except for the multicast group membership lookup which
	 * uses the IPv4 destination.
	 */
	IN6_IPADDR_TO_V4MAPPED(ipha->ipha_src, &v6faddr);
	connfp = &ipst->ips_ipcl_udp_fanout[IPCL_UDP_HASH(lport, ipst)];
	mutex_enter(&connfp->connf_lock);
	connp = connfp->connf_head;
	/*
	 * IPv4 multicast packet being delivered to an AF_INET6
	 * in6addr_any endpoint.
	 * Need to check conn_wantpacket(). Note that we use conn_wantpacket()
	 * and not conn_wantpacket_v6() since any multicast membership is
	 * for an IPv4-mapped multicast address.
	 */
	while (connp != NULL) {
		if (IPCL_UDP_MATCH_V6(connp, lport, ipv6_all_zeros,
		    fport, v6faddr) &&
		    conn_wantpacket(connp, ira, ipha) &&
		    (!(ira->ira_flags & IRAF_SYSTEM_LABELED) ||
		    tsol_receive_local(mp, &laddr, IPV4_VERSION, ira, connp)))
			break;
		connp = connp->conn_next;
	}

	if (connp == NULL) {
		/*
		 * No one bound to this port.  Is
		 * there a client that wants all
		 * unclaimed datagrams?
		 */
		mutex_exit(&connfp->connf_lock);

		if (ipst->ips_ipcl_proto_fanout_v4[IPPROTO_UDP].connf_head !=
		    NULL) {
			ASSERT(ira->ira_protocol == IPPROTO_UDP);
			ip_fanout_proto_v4(mp, ipha, ira);
		} else {
			/*
			 * We used to attempt to send an icmp error here, but
			 * since this is known to be a multicast packet
			 * and we don't send icmp errors in response to
			 * multicast, just drop the packet and give up sooner.
			 */
			BUMP_MIB(ill->ill_ip_mib, udpIfStatsNoPorts);
			freemsg(mp);
		}
		return;
	}
	ASSERT(IPCL_IS_NONSTR(connp) || connp->conn_rq != NULL);

	/*
	 * If SO_REUSEADDR has been set on the first we send the
	 * packet to all clients that have joined the group and
	 * match the port.
	 */
	if (connp->conn_reuseaddr) {
		conn_t		*first_connp = connp;
		conn_t		*next_connp;
		mblk_t		*mp1;

		CONN_INC_REF(connp);
		connp = connp->conn_next;
		for (;;) {
			while (connp != NULL) {
				if (IPCL_UDP_MATCH_V6(connp, lport,
				    ipv6_all_zeros, fport, v6faddr) &&
				    conn_wantpacket(connp, ira, ipha) &&
				    (!(ira->ira_flags & IRAF_SYSTEM_LABELED) ||
				    tsol_receive_local(mp, &laddr, IPV4_VERSION,
				    ira, connp)))
					break;
				connp = connp->conn_next;
			}
			if (connp == NULL) {
				/* No more interested clients */
				connp = first_connp;
				break;
			}
			if (((mp1 = dupmsg(mp)) == NULL) &&
			    ((mp1 = copymsg(mp)) == NULL)) {
				/* Memory allocation failed */
				BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
				ip_drop_input("ipIfStatsInDiscards", mp, ill);
				connp = first_connp;
				break;
			}
			CONN_INC_REF(connp);
			mutex_exit(&connfp->connf_lock);

			IP_STAT(ipst, ip_udp_fanmb);
			ip_fanout_udp_conn(connp, mp1, (ipha_t *)mp1->b_rptr,
			    NULL, ira);
			mutex_enter(&connfp->connf_lock);
			/* Follow the next pointer before releasing the conn */
			next_connp = connp->conn_next;
			CONN_DEC_REF(connp);
			connp = next_connp;
		}
	}

	/* Last one.  Send it upstream. */
	mutex_exit(&connfp->connf_lock);
	IP_STAT(ipst, ip_udp_fanmb);
	ip_fanout_udp_conn(connp, mp, ipha, NULL, ira);
	CONN_DEC_REF(connp);
}

/*
 * Split an incoming packet's IPv4 options into the label and the other options.
 * If 'allocate' is set it does memory allocation for the ip_pkt_t, including
 * clearing out any leftover label or options.
 * Otherwise it just makes ipp point into the packet.
 *
 * Returns zero if ok; ENOMEM if the buffer couldn't be allocated.
 */
int
ip_find_hdr_v4(ipha_t *ipha, ip_pkt_t *ipp, boolean_t allocate)
{
	uchar_t		*opt;
	uint32_t	totallen;
	uint32_t	optval;
	uint32_t	optlen;

	ipp->ipp_fields |= IPPF_HOPLIMIT | IPPF_TCLASS | IPPF_ADDR;
	ipp->ipp_hoplimit = ipha->ipha_ttl;
	ipp->ipp_type_of_service = ipha->ipha_type_of_service;
	IN6_IPADDR_TO_V4MAPPED(ipha->ipha_dst, &ipp->ipp_addr);

	/*
	 * Get length (in 4 byte octets) of IP header options.
	 */
	totallen = ipha->ipha_version_and_hdr_length -
	    (uint8_t)((IP_VERSION << 4) + IP_SIMPLE_HDR_LENGTH_IN_WORDS);

	if (totallen == 0) {
		if (!allocate)
			return (0);

		/* Clear out anything from a previous packet */
		if (ipp->ipp_fields & IPPF_IPV4_OPTIONS) {
			kmem_free(ipp->ipp_ipv4_options,
			    ipp->ipp_ipv4_options_len);
			ipp->ipp_ipv4_options = NULL;
			ipp->ipp_ipv4_options_len = 0;
			ipp->ipp_fields &= ~IPPF_IPV4_OPTIONS;
		}
		if (ipp->ipp_fields & IPPF_LABEL_V4) {
			kmem_free(ipp->ipp_label_v4, ipp->ipp_label_len_v4);
			ipp->ipp_label_v4 = NULL;
			ipp->ipp_label_len_v4 = 0;
			ipp->ipp_fields &= ~IPPF_LABEL_V4;
		}
		return (0);
	}

	totallen <<= 2;
	opt = (uchar_t *)&ipha[1];
	if (!is_system_labeled()) {

	copyall:
		if (!allocate) {
			if (totallen != 0) {
				ipp->ipp_ipv4_options = opt;
				ipp->ipp_ipv4_options_len = totallen;
				ipp->ipp_fields |= IPPF_IPV4_OPTIONS;
			}
			return (0);
		}
		/* Just copy all of options */
		if (ipp->ipp_fields & IPPF_IPV4_OPTIONS) {
			if (totallen == ipp->ipp_ipv4_options_len) {
				bcopy(opt, ipp->ipp_ipv4_options, totallen);
				return (0);
			}
			kmem_free(ipp->ipp_ipv4_options,
			    ipp->ipp_ipv4_options_len);
			ipp->ipp_ipv4_options = NULL;
			ipp->ipp_ipv4_options_len = 0;
			ipp->ipp_fields &= ~IPPF_IPV4_OPTIONS;
		}
		if (totallen == 0)
			return (0);

		ipp->ipp_ipv4_options = kmem_alloc(totallen, KM_NOSLEEP);
		if (ipp->ipp_ipv4_options == NULL)
			return (ENOMEM);
		ipp->ipp_ipv4_options_len = totallen;
		ipp->ipp_fields |= IPPF_IPV4_OPTIONS;
		bcopy(opt, ipp->ipp_ipv4_options, totallen);
		return (0);
	}

	if (allocate && (ipp->ipp_fields & IPPF_LABEL_V4)) {
		kmem_free(ipp->ipp_label_v4, ipp->ipp_label_len_v4);
		ipp->ipp_label_v4 = NULL;
		ipp->ipp_label_len_v4 = 0;
		ipp->ipp_fields &= ~IPPF_LABEL_V4;
	}

	/*
	 * Search for CIPSO option.
	 * We assume CIPSO is first in options if it is present.
	 * If it isn't, then ipp_opt_ipv4_options will not include the options
	 * prior to the CIPSO option.
	 */
	while (totallen != 0) {
		switch (optval = opt[IPOPT_OPTVAL]) {
		case IPOPT_EOL:
			return (0);
		case IPOPT_NOP:
			optlen = 1;
			break;
		default:
			if (totallen <= IPOPT_OLEN)
				return (EINVAL);
			optlen = opt[IPOPT_OLEN];
			if (optlen < 2)
				return (EINVAL);
		}
		if (optlen > totallen)
			return (EINVAL);

		switch (optval) {
		case IPOPT_COMSEC:
			if (!allocate) {
				ipp->ipp_label_v4 = opt;
				ipp->ipp_label_len_v4 = optlen;
				ipp->ipp_fields |= IPPF_LABEL_V4;
			} else {
				ipp->ipp_label_v4 = kmem_alloc(optlen,
				    KM_NOSLEEP);
				if (ipp->ipp_label_v4 == NULL)
					return (ENOMEM);
				ipp->ipp_label_len_v4 = optlen;
				ipp->ipp_fields |= IPPF_LABEL_V4;
				bcopy(opt, ipp->ipp_label_v4, optlen);
			}
			totallen -= optlen;
			opt += optlen;

			/* Skip padding bytes until we get to a multiple of 4 */
			while ((totallen & 3) != 0 && opt[0] == IPOPT_NOP) {
				totallen--;
				opt++;
			}
			/* Remaining as ipp_ipv4_options */
			goto copyall;
		}
		totallen -= optlen;
		opt += optlen;
	}
	/* No CIPSO found; return everything as ipp_ipv4_options */
	totallen = ipha->ipha_version_and_hdr_length -
	    (uint8_t)((IP_VERSION << 4) + IP_SIMPLE_HDR_LENGTH_IN_WORDS);
	totallen <<= 2;
	opt = (uchar_t *)&ipha[1];
	goto copyall;
}

/*
 * Efficient versions of lookup for an IRE when we only
 * match the address.
 * For RTF_REJECT or BLACKHOLE we return IRE_NOROUTE.
 * Does not handle multicast addresses.
 */
uint_t
ip_type_v4(ipaddr_t addr, ip_stack_t *ipst)
{
	ire_t *ire;
	uint_t result;

	ire = ire_ftable_lookup_simple_v4(addr, 0, ipst, NULL);
	ASSERT(ire != NULL);
	if (ire->ire_flags & (RTF_REJECT|RTF_BLACKHOLE))
		result = IRE_NOROUTE;
	else
		result = ire->ire_type;
	ire_refrele(ire);
	return (result);
}

/*
 * Efficient versions of lookup for an IRE when we only
 * match the address.
 * For RTF_REJECT or BLACKHOLE we return IRE_NOROUTE.
 * Does not handle multicast addresses.
 */
uint_t
ip_type_v6(const in6_addr_t *addr, ip_stack_t *ipst)
{
	ire_t *ire;
	uint_t result;

	ire = ire_ftable_lookup_simple_v6(addr, 0, ipst, NULL);
	ASSERT(ire != NULL);
	if (ire->ire_flags & (RTF_REJECT|RTF_BLACKHOLE))
		result = IRE_NOROUTE;
	else
		result = ire->ire_type;
	ire_refrele(ire);
	return (result);
}

/*
 * Nobody should be sending
 * packets up this stream
 */
static void
ip_lrput(queue_t *q, mblk_t *mp)
{
	switch (mp->b_datap->db_type) {
	case M_FLUSH:
		/* Turn around */
		if (*mp->b_rptr & FLUSHW) {
			*mp->b_rptr &= ~FLUSHR;
			qreply(q, mp);
			return;
		}
		break;
	}
	freemsg(mp);
}

/* Nobody should be sending packets down this stream */
/* ARGSUSED */
void
ip_lwput(queue_t *q, mblk_t *mp)
{
	freemsg(mp);
}

/*
 * Move the first hop in any source route to ipha_dst and remove that part of
 * the source route.  Called by other protocols.  Errors in option formatting
 * are ignored - will be handled by ip_output_options. Return the final
 * destination (either ipha_dst or the last entry in a source route.)
 */
ipaddr_t
ip_massage_options(ipha_t *ipha, netstack_t *ns)
{
	ipoptp_t	opts;
	uchar_t		*opt;
	uint8_t		optval;
	uint8_t		optlen;
	ipaddr_t	dst;
	int		i;
	ip_stack_t	*ipst = ns->netstack_ip;

	ip2dbg(("ip_massage_options\n"));
	dst = ipha->ipha_dst;
	for (optval = ipoptp_first(&opts, ipha);
	    optval != IPOPT_EOL;
	    optval = ipoptp_next(&opts)) {
		opt = opts.ipoptp_cur;
		switch (optval) {
			uint8_t off;
		case IPOPT_SSRR:
		case IPOPT_LSRR:
			if ((opts.ipoptp_flags & IPOPTP_ERROR) != 0) {
				ip1dbg(("ip_massage_options: bad src route\n"));
				break;
			}
			optlen = opts.ipoptp_len;
			off = opt[IPOPT_OFFSET];
			off--;
		redo_srr:
			if (optlen < IP_ADDR_LEN ||
			    off > optlen - IP_ADDR_LEN) {
				/* End of source route */
				ip1dbg(("ip_massage_options: end of SR\n"));
				break;
			}
			bcopy((char *)opt + off, &dst, IP_ADDR_LEN);
			ip1dbg(("ip_massage_options: next hop 0x%x\n",
			    ntohl(dst)));
			/*
			 * Check if our address is present more than
			 * once as consecutive hops in source route.
			 * XXX verify per-interface ip_forwarding
			 * for source route?
			 */
			if (ip_type_v4(dst, ipst) == IRE_LOCAL) {
				off += IP_ADDR_LEN;
				goto redo_srr;
			}
			if (dst == htonl(INADDR_LOOPBACK)) {
				ip1dbg(("ip_massage_options: loopback addr in "
				    "source route!\n"));
				break;
			}
			/*
			 * Update ipha_dst to be the first hop and remove the
			 * first hop from the source route (by overwriting
			 * part of the option with NOP options).
			 */
			ipha->ipha_dst = dst;
			/* Put the last entry in dst */
			off = ((optlen - IP_ADDR_LEN - 3) & ~(IP_ADDR_LEN-1)) +
			    3;
			bcopy(&opt[off], &dst, IP_ADDR_LEN);

			ip1dbg(("ip_massage_options: last hop 0x%x\n",
			    ntohl(dst)));
			/* Move down and overwrite */
			opt[IP_ADDR_LEN] = opt[0];
			opt[IP_ADDR_LEN+1] = opt[IPOPT_OLEN] - IP_ADDR_LEN;
			opt[IP_ADDR_LEN+2] = opt[IPOPT_OFFSET];
			for (i = 0; i < IP_ADDR_LEN; i++)
				opt[i] = IPOPT_NOP;
			break;
		}
	}
	return (dst);
}

/*
 * Return the network mask
 * associated with the specified address.
 */
ipaddr_t
ip_net_mask(ipaddr_t addr)
{
	uchar_t	*up = (uchar_t *)&addr;
	ipaddr_t mask = 0;
	uchar_t	*maskp = (uchar_t *)&mask;

#if defined(__i386) || defined(__amd64)
#define	TOTALLY_BRAIN_DAMAGED_C_COMPILER
#endif
#ifdef  TOTALLY_BRAIN_DAMAGED_C_COMPILER
	maskp[0] = maskp[1] = maskp[2] = maskp[3] = 0;
#endif
	if (CLASSD(addr)) {
		maskp[0] = 0xF0;
		return (mask);
	}

	/* We assume Class E default netmask to be 32 */
	if (CLASSE(addr))
		return (0xffffffffU);

	if (addr == 0)
		return (0);
	maskp[0] = 0xFF;
	if ((up[0] & 0x80) == 0)
		return (mask);

	maskp[1] = 0xFF;
	if ((up[0] & 0xC0) == 0x80)
		return (mask);

	maskp[2] = 0xFF;
	if ((up[0] & 0xE0) == 0xC0)
		return (mask);

	/* Otherwise return no mask */
	return ((ipaddr_t)0);
}

/* Name/Value Table Lookup Routine */
char *
ip_nv_lookup(nv_t *nv, int value)
{
	if (!nv)
		return (NULL);
	for (; nv->nv_name; nv++) {
		if (nv->nv_value == value)
			return (nv->nv_name);
	}
	return ("unknown");
}

static int
ip_wait_for_info_ack(ill_t *ill)
{
	int err;

	mutex_enter(&ill->ill_lock);
	while (ill->ill_state_flags & ILL_LL_SUBNET_PENDING) {
		/*
		 * Return value of 0 indicates a pending signal.
		 */
		err = cv_wait_sig(&ill->ill_cv, &ill->ill_lock);
		if (err == 0) {
			mutex_exit(&ill->ill_lock);
			return (EINTR);
		}
	}
	mutex_exit(&ill->ill_lock);
	/*
	 * ip_rput_other could have set an error  in ill_error on
	 * receipt of M_ERROR.
	 */
	return (ill->ill_error);
}

/*
 * This is a module open, i.e. this is a control stream for access
 * to a DLPI device.  We allocate an ill_t as the instance data in
 * this case.
 */
static int
ip_modopen(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp)
{
	ill_t	*ill;
	int	err;
	zoneid_t zoneid;
	netstack_t *ns;
	ip_stack_t *ipst;

	/*
	 * Prevent unprivileged processes from pushing IP so that
	 * they can't send raw IP.
	 */
	if (secpolicy_net_rawaccess(credp) != 0)
		return (EPERM);

	ns = netstack_find_by_cred(credp);
	ASSERT(ns != NULL);
	ipst = ns->netstack_ip;
	ASSERT(ipst != NULL);

	/*
	 * For exclusive stacks we set the zoneid to zero
	 * to make IP operate as if in the global zone.
	 */
	if (ipst->ips_netstack->netstack_stackid != GLOBAL_NETSTACKID)
		zoneid = GLOBAL_ZONEID;
	else
		zoneid = crgetzoneid(credp);

	ill = (ill_t *)mi_open_alloc_sleep(sizeof (ill_t));
	q->q_ptr = WR(q)->q_ptr = ill;
	ill->ill_ipst = ipst;
	ill->ill_zoneid = zoneid;

	/*
	 * ill_init initializes the ill fields and then sends down
	 * down a DL_INFO_REQ after calling qprocson.
	 */
	err = ill_init(q, ill);

	if (err != 0) {
		mi_free(ill);
		netstack_rele(ipst->ips_netstack);
		q->q_ptr = NULL;
		WR(q)->q_ptr = NULL;
		return (err);
	}

	/*
	 * Wait for the DL_INFO_ACK if a DL_INFO_REQ was sent.
	 *
	 * ill_init initializes the ipsq marking this thread as
	 * writer
	 */
	ipsq_exit(ill->ill_phyint->phyint_ipsq);
	err = ip_wait_for_info_ack(ill);
	if (err == 0)
		ill->ill_credp = credp;
	else
		goto fail;

	crhold(credp);

	mutex_enter(&ipst->ips_ip_mi_lock);
	err = mi_open_link(&ipst->ips_ip_g_head, (IDP)q->q_ptr, devp, flag,
	    sflag, credp);
	mutex_exit(&ipst->ips_ip_mi_lock);
fail:
	if (err) {
		(void) ip_close(q, 0);
		return (err);
	}
	return (0);
}

/* For /dev/ip aka AF_INET open */
int
ip_openv4(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp)
{
	return (ip_open(q, devp, flag, sflag, credp, B_FALSE));
}

/* For /dev/ip6 aka AF_INET6 open */
int
ip_openv6(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp)
{
	return (ip_open(q, devp, flag, sflag, credp, B_TRUE));
}

/* IP open routine. */
int
ip_open(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp,
    boolean_t isv6)
{
	conn_t 		*connp;
	major_t		maj;
	zoneid_t	zoneid;
	netstack_t	*ns;
	ip_stack_t	*ipst;

	/* Allow reopen. */
	if (q->q_ptr != NULL)
		return (0);

	if (sflag & MODOPEN) {
		/* This is a module open */
		return (ip_modopen(q, devp, flag, sflag, credp));
	}

	if ((flag & ~(FKLYR)) == IP_HELPER_STR) {
		/*
		 * Non streams based socket looking for a stream
		 * to access IP
		 */
		return (ip_helper_stream_setup(q, devp, flag, sflag,
		    credp, isv6));
	}

	ns = netstack_find_by_cred(credp);
	ASSERT(ns != NULL);
	ipst = ns->netstack_ip;
	ASSERT(ipst != NULL);

	/*
	 * For exclusive stacks we set the zoneid to zero
	 * to make IP operate as if in the global zone.
	 */
	if (ipst->ips_netstack->netstack_stackid != GLOBAL_NETSTACKID)
		zoneid = GLOBAL_ZONEID;
	else
		zoneid = crgetzoneid(credp);

	/*
	 * We are opening as a device. This is an IP client stream, and we
	 * allocate an conn_t as the instance data.
	 */
	connp = ipcl_conn_create(IPCL_IPCCONN, KM_SLEEP, ipst->ips_netstack);

	/*
	 * ipcl_conn_create did a netstack_hold. Undo the hold that was
	 * done by netstack_find_by_cred()
	 */
	netstack_rele(ipst->ips_netstack);

	connp->conn_ixa->ixa_flags |= IXAF_MULTICAST_LOOP | IXAF_SET_ULP_CKSUM;
	/* conn_allzones can not be set this early, hence no IPCL_ZONEID */
	connp->conn_ixa->ixa_zoneid = zoneid;
	connp->conn_zoneid = zoneid;

	connp->conn_rq = q;
	q->q_ptr = WR(q)->q_ptr = connp;

	/* Minor tells us which /dev entry was opened */
	if (isv6) {
		connp->conn_family = AF_INET6;
		connp->conn_ipversion = IPV6_VERSION;
		connp->conn_ixa->ixa_flags &= ~IXAF_IS_IPV4;
		connp->conn_ixa->ixa_src_preferences = IPV6_PREFER_SRC_DEFAULT;
	} else {
		connp->conn_family = AF_INET;
		connp->conn_ipversion = IPV4_VERSION;
		connp->conn_ixa->ixa_flags |= IXAF_IS_IPV4;
	}

	if ((ip_minor_arena_la != NULL) && (flag & SO_SOCKSTR) &&
	    ((connp->conn_dev = inet_minor_alloc(ip_minor_arena_la)) != 0)) {
		connp->conn_minor_arena = ip_minor_arena_la;
	} else {
		/*
		 * Either minor numbers in the large arena were exhausted
		 * or a non socket application is doing the open.
		 * Try to allocate from the small arena.
		 */
		if ((connp->conn_dev =
		    inet_minor_alloc(ip_minor_arena_sa)) == 0) {
			/* CONN_DEC_REF takes care of netstack_rele() */
			q->q_ptr = WR(q)->q_ptr = NULL;
			CONN_DEC_REF(connp);
			return (EBUSY);
		}
		connp->conn_minor_arena = ip_minor_arena_sa;
	}

	maj = getemajor(*devp);
	*devp = makedevice(maj, (minor_t)connp->conn_dev);

	/*
	 * connp->conn_cred is crfree()ed in ipcl_conn_destroy()
	 */
	connp->conn_cred = credp;
	/* Cache things in ixa without an extra refhold */
	connp->conn_ixa->ixa_cred = connp->conn_cred;
	connp->conn_ixa->ixa_cpid = connp->conn_cpid;
	if (is_system_labeled())
		connp->conn_ixa->ixa_tsl = crgetlabel(connp->conn_cred);

	/*
	 * Handle IP_IOC_RTS_REQUEST and other ioctls which use conn_recv
	 */
	connp->conn_recv = ip_conn_input;
	connp->conn_recvicmp = ip_conn_input_icmp;

	crhold(connp->conn_cred);

	/*
	 * If the caller has the process-wide flag set, then default to MAC
	 * exempt mode.  This allows read-down to unlabeled hosts.
	 */
	if (getpflags(NET_MAC_AWARE, credp) != 0)
		connp->conn_mac_mode = CONN_MAC_AWARE;

	connp->conn_zone_is_global = (crgetzoneid(credp) == GLOBAL_ZONEID);

	connp->conn_rq = q;
	connp->conn_wq = WR(q);

	/* Non-zero default values */
	connp->conn_ixa->ixa_flags |= IXAF_MULTICAST_LOOP;

	/*
	 * Make the conn globally visible to walkers
	 */
	ASSERT(connp->conn_ref == 1);
	mutex_enter(&connp->conn_lock);
	connp->conn_state_flags &= ~CONN_INCIPIENT;
	mutex_exit(&connp->conn_lock);

	qprocson(q);

	return (0);
}

/*
 * Set IPsec policy from an ipsec_req_t. If the req is not "zero" and valid,
 * all of them are copied to the conn_t. If the req is "zero", the policy is
 * zeroed out. A "zero" policy has zero ipsr_{ah,req,self_encap}_req
 * fields.
 * We keep only the latest setting of the policy and thus policy setting
 * is not incremental/cumulative.
 *
 * Requests to set policies with multiple alternative actions will
 * go through a different API.
 */
int
ipsec_set_req(cred_t *cr, conn_t *connp, ipsec_req_t *req)
{
	uint_t ah_req = 0;
	uint_t esp_req = 0;
	uint_t se_req = 0;
	ipsec_act_t *actp = NULL;
	uint_t nact;
	ipsec_policy_head_t *ph;
	boolean_t is_pol_reset, is_pol_inserted = B_FALSE;
	int error = 0;
	netstack_t	*ns = connp->conn_netstack;
	ip_stack_t	*ipst = ns->netstack_ip;
	ipsec_stack_t	*ipss = ns->netstack_ipsec;

#define	REQ_MASK (IPSEC_PREF_REQUIRED|IPSEC_PREF_NEVER)

	/*
	 * The IP_SEC_OPT option does not allow variable length parameters,
	 * hence a request cannot be NULL.
	 */
	if (req == NULL)
		return (EINVAL);

	ah_req = req->ipsr_ah_req;
	esp_req = req->ipsr_esp_req;
	se_req = req->ipsr_self_encap_req;

	/* Don't allow setting self-encap without one or more of AH/ESP. */
	if (se_req != 0 && esp_req == 0 && ah_req == 0)
		return (EINVAL);

	/*
	 * Are we dealing with a request to reset the policy (i.e.
	 * zero requests).
	 */
	is_pol_reset = ((ah_req & REQ_MASK) == 0 &&
	    (esp_req & REQ_MASK) == 0 &&
	    (se_req & REQ_MASK) == 0);

	if (!is_pol_reset) {
		/*
		 * If we couldn't load IPsec, fail with "protocol
		 * not supported".
		 * IPsec may not have been loaded for a request with zero
		 * policies, so we don't fail in this case.
		 */
		mutex_enter(&ipss->ipsec_loader_lock);
		if (ipss->ipsec_loader_state != IPSEC_LOADER_SUCCEEDED) {
			mutex_exit(&ipss->ipsec_loader_lock);
			return (EPROTONOSUPPORT);
		}
		mutex_exit(&ipss->ipsec_loader_lock);

		/*
		 * Test for valid requests. Invalid algorithms
		 * need to be tested by IPsec code because new
		 * algorithms can be added dynamically.
		 */
		if ((ah_req & ~(REQ_MASK|IPSEC_PREF_UNIQUE)) != 0 ||
		    (esp_req & ~(REQ_MASK|IPSEC_PREF_UNIQUE)) != 0 ||
		    (se_req & ~(REQ_MASK|IPSEC_PREF_UNIQUE)) != 0) {
			return (EINVAL);
		}

		/*
		 * Only privileged users can issue these
		 * requests.
		 */
		if (((ah_req & IPSEC_PREF_NEVER) ||
		    (esp_req & IPSEC_PREF_NEVER) ||
		    (se_req & IPSEC_PREF_NEVER)) &&
		    secpolicy_ip_config(cr, B_FALSE) != 0) {
			return (EPERM);
		}

		/*
		 * The IPSEC_PREF_REQUIRED and IPSEC_PREF_NEVER
		 * are mutually exclusive.
		 */
		if (((ah_req & REQ_MASK) == REQ_MASK) ||
		    ((esp_req & REQ_MASK) == REQ_MASK) ||
		    ((se_req & REQ_MASK) == REQ_MASK)) {
			/* Both of them are set */
			return (EINVAL);
		}
	}

	ASSERT(MUTEX_HELD(&connp->conn_lock));

	/*
	 * If we have already cached policies in conn_connect(), don't
	 * let them change now. We cache policies for connections
	 * whose src,dst [addr, port] is known.
	 */
	if (connp->conn_policy_cached) {
		return (EINVAL);
	}

	/*
	 * We have a zero policies, reset the connection policy if already
	 * set. This will cause the connection to inherit the
	 * global policy, if any.
	 */
	if (is_pol_reset) {
		if (connp->conn_policy != NULL) {
			IPPH_REFRELE(connp->conn_policy, ipst->ips_netstack);
			connp->conn_policy = NULL;
		}
		connp->conn_in_enforce_policy = B_FALSE;
		connp->conn_out_enforce_policy = B_FALSE;
		return (0);
	}

	ph = connp->conn_policy = ipsec_polhead_split(connp->conn_policy,
	    ipst->ips_netstack);
	if (ph == NULL)
		goto enomem;

	ipsec_actvec_from_req(req, &actp, &nact, ipst->ips_netstack);
	if (actp == NULL)
		goto enomem;

	/*
	 * Always insert IPv4 policy entries, since they can also apply to
	 * ipv6 sockets being used in ipv4-compat mode.
	 */
	if (!ipsec_polhead_insert(ph, actp, nact, IPSEC_AF_V4,
	    IPSEC_TYPE_INBOUND, ns))
		goto enomem;
	is_pol_inserted = B_TRUE;
	if (!ipsec_polhead_insert(ph, actp, nact, IPSEC_AF_V4,
	    IPSEC_TYPE_OUTBOUND, ns))
		goto enomem;

	/*
	 * We're looking at a v6 socket, also insert the v6-specific
	 * entries.
	 */
	if (connp->conn_family == AF_INET6) {
		if (!ipsec_polhead_insert(ph, actp, nact, IPSEC_AF_V6,
		    IPSEC_TYPE_INBOUND, ns))
			goto enomem;
		if (!ipsec_polhead_insert(ph, actp, nact, IPSEC_AF_V6,
		    IPSEC_TYPE_OUTBOUND, ns))
			goto enomem;
	}

	ipsec_actvec_free(actp, nact);

	/*
	 * If the requests need security, set enforce_policy.
	 * If the requests are IPSEC_PREF_NEVER, one should
	 * still set conn_out_enforce_policy so that ip_set_destination
	 * marks the ip_xmit_attr_t appropriatly. This is needed so that
	 * for connections that we don't cache policy in at connect time,
	 * if global policy matches in ip_output_attach_policy, we
	 * don't wrongly inherit global policy. Similarly, we need
	 * to set conn_in_enforce_policy also so that we don't verify
	 * policy wrongly.
	 */
	if ((ah_req & REQ_MASK) != 0 ||
	    (esp_req & REQ_MASK) != 0 ||
	    (se_req & REQ_MASK) != 0) {
		connp->conn_in_enforce_policy = B_TRUE;
		connp->conn_out_enforce_policy = B_TRUE;
	}

	return (error);
#undef REQ_MASK

	/*
	 * Common memory-allocation-failure exit path.
	 */
enomem:
	if (actp != NULL)
		ipsec_actvec_free(actp, nact);
	if (is_pol_inserted)
		ipsec_polhead_flush(ph, ns);
	return (ENOMEM);
}

/*
 * Set socket options for joining and leaving multicast groups.
 * Common to IPv4 and IPv6; inet6 indicates the type of socket.
 * The caller has already check that the option name is consistent with
 * the address family of the socket.
 */
int
ip_opt_set_multicast_group(conn_t *connp, t_scalar_t name,
    uchar_t *invalp, boolean_t inet6, boolean_t checkonly)
{
	int		*i1 = (int *)invalp;
	int		error = 0;
	ip_stack_t	*ipst = connp->conn_netstack->netstack_ip;
	struct ip_mreq	*v4_mreqp;
	struct ipv6_mreq *v6_mreqp;
	struct group_req *greqp;
	ire_t *ire;
	boolean_t done = B_FALSE;
	ipaddr_t ifaddr;
	in6_addr_t v6group;
	uint_t ifindex;
	boolean_t mcast_opt = B_TRUE;
	mcast_record_t fmode;
	int (*optfn)(conn_t *, boolean_t, const in6_addr_t *,
	    ipaddr_t, uint_t, mcast_record_t, const in6_addr_t *);

	switch (name) {
	case IP_ADD_MEMBERSHIP:
	case IPV6_JOIN_GROUP:
		mcast_opt = B_FALSE;
		/* FALLTHRU */
	case MCAST_JOIN_GROUP:
		fmode = MODE_IS_EXCLUDE;
		optfn = ip_opt_add_group;
		break;

	case IP_DROP_MEMBERSHIP:
	case IPV6_LEAVE_GROUP:
		mcast_opt = B_FALSE;
		/* FALLTHRU */
	case MCAST_LEAVE_GROUP:
		fmode = MODE_IS_INCLUDE;
		optfn = ip_opt_delete_group;
		break;
	default:
		ASSERT(0);
	}

	if (mcast_opt) {
		struct sockaddr_in *sin;
		struct sockaddr_in6 *sin6;

		greqp = (struct group_req *)i1;
		if (greqp->gr_group.ss_family == AF_INET) {
			sin = (struct sockaddr_in *)&(greqp->gr_group);
			IN6_INADDR_TO_V4MAPPED(&sin->sin_addr, &v6group);
		} else {
			if (!inet6)
				return (EINVAL);	/* Not on INET socket */

			sin6 = (struct sockaddr_in6 *)&(greqp->gr_group);
			v6group = sin6->sin6_addr;
		}
		ifaddr = INADDR_ANY;
		ifindex = greqp->gr_interface;
	} else if (inet6) {
		v6_mreqp = (struct ipv6_mreq *)i1;
		v6group = v6_mreqp->ipv6mr_multiaddr;
		ifaddr = INADDR_ANY;
		ifindex = v6_mreqp->ipv6mr_interface;
	} else {
		v4_mreqp = (struct ip_mreq *)i1;
		IN6_INADDR_TO_V4MAPPED(&v4_mreqp->imr_multiaddr, &v6group);
		ifaddr = (ipaddr_t)v4_mreqp->imr_interface.s_addr;
		ifindex = 0;
	}

	/*
	 * In the multirouting case, we need to replicate
	 * the request on all interfaces that will take part
	 * in replication.  We do so because multirouting is
	 * reflective, thus we will probably receive multi-
	 * casts on those interfaces.
	 * The ip_multirt_apply_membership() succeeds if
	 * the operation succeeds on at least one interface.
	 */
	if (IN6_IS_ADDR_V4MAPPED(&v6group)) {
		ipaddr_t group;

		IN6_V4MAPPED_TO_IPADDR(&v6group, group);

		ire = ire_ftable_lookup_v4(group, IP_HOST_MASK, 0,
		    IRE_HOST | IRE_INTERFACE, NULL, ALL_ZONES, NULL,
		    MATCH_IRE_MASK | MATCH_IRE_TYPE, 0, ipst, NULL);
	} else {
		ire = ire_ftable_lookup_v6(&v6group, &ipv6_all_ones, 0,
		    IRE_HOST | IRE_INTERFACE, NULL, ALL_ZONES, NULL,
		    MATCH_IRE_MASK | MATCH_IRE_TYPE, 0, ipst, NULL);
	}
	if (ire != NULL) {
		if (ire->ire_flags & RTF_MULTIRT) {
			error = ip_multirt_apply_membership(optfn, ire, connp,
			    checkonly, &v6group, fmode, &ipv6_all_zeros);
			done = B_TRUE;
		}
		ire_refrele(ire);
	}

	if (!done) {
		error = optfn(connp, checkonly, &v6group, ifaddr, ifindex,
		    fmode, &ipv6_all_zeros);
	}
	return (error);
}

/*
 * Set socket options for joining and leaving multicast groups
 * for specific sources.
 * Common to IPv4 and IPv6; inet6 indicates the type of socket.
 * The caller has already check that the option name is consistent with
 * the address family of the socket.
 */
int
ip_opt_set_multicast_sources(conn_t *connp, t_scalar_t name,
    uchar_t *invalp, boolean_t inet6, boolean_t checkonly)
{
	int		*i1 = (int *)invalp;
	int		error = 0;
	ip_stack_t	*ipst = connp->conn_netstack->netstack_ip;
	struct ip_mreq_source *imreqp;
	struct group_source_req *gsreqp;
	in6_addr_t v6group, v6src;
	uint32_t ifindex;
	ipaddr_t ifaddr;
	boolean_t mcast_opt = B_TRUE;
	mcast_record_t fmode;
	ire_t *ire;
	boolean_t done = B_FALSE;
	int (*optfn)(conn_t *, boolean_t, const in6_addr_t *,
	    ipaddr_t, uint_t, mcast_record_t, const in6_addr_t *);

	switch (name) {
	case IP_BLOCK_SOURCE:
		mcast_opt = B_FALSE;
		/* FALLTHRU */
	case MCAST_BLOCK_SOURCE:
		fmode = MODE_IS_EXCLUDE;
		optfn = ip_opt_add_group;
		break;

	case IP_UNBLOCK_SOURCE:
		mcast_opt = B_FALSE;
		/* FALLTHRU */
	case MCAST_UNBLOCK_SOURCE:
		fmode = MODE_IS_EXCLUDE;
		optfn = ip_opt_delete_group;
		break;

	case IP_ADD_SOURCE_MEMBERSHIP:
		mcast_opt = B_FALSE;
		/* FALLTHRU */
	case MCAST_JOIN_SOURCE_GROUP:
		fmode = MODE_IS_INCLUDE;
		optfn = ip_opt_add_group;
		break;

	case IP_DROP_SOURCE_MEMBERSHIP:
		mcast_opt = B_FALSE;
		/* FALLTHRU */
	case MCAST_LEAVE_SOURCE_GROUP:
		fmode = MODE_IS_INCLUDE;
		optfn = ip_opt_delete_group;
		break;
	default:
		ASSERT(0);
	}

	if (mcast_opt) {
		gsreqp = (struct group_source_req *)i1;
		ifindex = gsreqp->gsr_interface;
		if (gsreqp->gsr_group.ss_family == AF_INET) {
			struct sockaddr_in *s;
			s = (struct sockaddr_in *)&gsreqp->gsr_group;
			IN6_INADDR_TO_V4MAPPED(&s->sin_addr, &v6group);
			s = (struct sockaddr_in *)&gsreqp->gsr_source;
			IN6_INADDR_TO_V4MAPPED(&s->sin_addr, &v6src);
		} else {
			struct sockaddr_in6 *s6;

			if (!inet6)
				return (EINVAL);	/* Not on INET socket */

			s6 = (struct sockaddr_in6 *)&gsreqp->gsr_group;
			v6group = s6->sin6_addr;
			s6 = (struct sockaddr_in6 *)&gsreqp->gsr_source;
			v6src = s6->sin6_addr;
		}
		ifaddr = INADDR_ANY;
	} else {
		imreqp = (struct ip_mreq_source *)i1;
		IN6_INADDR_TO_V4MAPPED(&imreqp->imr_multiaddr, &v6group);
		IN6_INADDR_TO_V4MAPPED(&imreqp->imr_sourceaddr, &v6src);
		ifaddr = (ipaddr_t)imreqp->imr_interface.s_addr;
		ifindex = 0;
	}

	/*
	 * Handle src being mapped INADDR_ANY by changing it to unspecified.
	 */
	if (IN6_IS_ADDR_V4MAPPED_ANY(&v6src))
		v6src = ipv6_all_zeros;

	/*
	 * In the multirouting case, we need to replicate
	 * the request as noted in the mcast cases above.
	 */
	if (IN6_IS_ADDR_V4MAPPED(&v6group)) {
		ipaddr_t group;

		IN6_V4MAPPED_TO_IPADDR(&v6group, group);

		ire = ire_ftable_lookup_v4(group, IP_HOST_MASK, 0,
		    IRE_HOST | IRE_INTERFACE, NULL, ALL_ZONES, NULL,
		    MATCH_IRE_MASK | MATCH_IRE_TYPE, 0, ipst, NULL);
	} else {
		ire = ire_ftable_lookup_v6(&v6group, &ipv6_all_ones, 0,
		    IRE_HOST | IRE_INTERFACE, NULL, ALL_ZONES, NULL,
		    MATCH_IRE_MASK | MATCH_IRE_TYPE, 0, ipst, NULL);
	}
	if (ire != NULL) {
		if (ire->ire_flags & RTF_MULTIRT) {
			error = ip_multirt_apply_membership(optfn, ire, connp,
			    checkonly, &v6group, fmode, &v6src);
			done = B_TRUE;
		}
		ire_refrele(ire);
	}
	if (!done) {
		error = optfn(connp, checkonly, &v6group, ifaddr, ifindex,
		    fmode, &v6src);
	}
	return (error);
}

/*
 * Given a destination address and a pointer to where to put the information
 * this routine fills in the mtuinfo.
 * The socket must be connected.
 * For sctp conn_faddr is the primary address.
 */
int
ip_fill_mtuinfo(conn_t *connp, ip_xmit_attr_t *ixa, struct ip6_mtuinfo *mtuinfo)
{
	uint32_t	pmtu = IP_MAXPACKET;
	uint_t		scopeid;

	if (IN6_IS_ADDR_UNSPECIFIED(&connp->conn_faddr_v6))
		return (-1);

	/* In case we never sent or called ip_set_destination_v4/v6 */
	if (ixa->ixa_ire != NULL)
		pmtu = ip_get_pmtu(ixa);

	if (ixa->ixa_flags & IXAF_SCOPEID_SET)
		scopeid = ixa->ixa_scopeid;
	else
		scopeid = 0;

	bzero(mtuinfo, sizeof (*mtuinfo));
	mtuinfo->ip6m_addr.sin6_family = AF_INET6;
	mtuinfo->ip6m_addr.sin6_port = connp->conn_fport;
	mtuinfo->ip6m_addr.sin6_addr = connp->conn_faddr_v6;
	mtuinfo->ip6m_addr.sin6_scope_id = scopeid;
	mtuinfo->ip6m_mtu = pmtu;

	return (sizeof (struct ip6_mtuinfo));
}

/* Named Dispatch routine to get a current value out of our parameter table. */
/* ARGSUSED */
static int
ip_param_get(queue_t *q, mblk_t *mp, caddr_t cp, cred_t *ioc_cr)
{
	ipparam_t *ippa = (ipparam_t *)cp;

	(void) mi_mpprintf(mp, "%d", ippa->ip_param_value);
	return (0);
}

/* ARGSUSED */
static int
ip_param_generic_get(queue_t *q, mblk_t *mp, caddr_t cp, cred_t *ioc_cr)
{

	(void) mi_mpprintf(mp, "%d", *(int *)cp);
	return (0);
}

/*
 * Set ip{,6}_forwarding values.  This means walking through all of the
 * ill's and toggling their forwarding values.
 */
/* ARGSUSED */
static int
ip_forward_set(queue_t *q, mblk_t *mp, char *value, caddr_t cp, cred_t *ioc_cr)
{
	long new_value;
	int *forwarding_value = (int *)cp;
	ill_t *ill;
	boolean_t isv6;
	ill_walk_context_t ctx;
	ip_stack_t *ipst = CONNQ_TO_IPST(q);

	isv6 = (forwarding_value == &ipst->ips_ipv6_forward);

	if (ddi_strtol(value, NULL, 10, &new_value) != 0 ||
	    new_value < 0 || new_value > 1) {
		return (EINVAL);
	}

	*forwarding_value = new_value;

	/*
	 * Regardless of the current value of ip_forwarding, set all per-ill
	 * values of ip_forwarding to the value being set.
	 *
	 * Bring all the ill's up to date with the new global value.
	 */
	rw_enter(&ipst->ips_ill_g_lock, RW_READER);

	if (isv6)
		ill = ILL_START_WALK_V6(&ctx, ipst);
	else
		ill = ILL_START_WALK_V4(&ctx, ipst);

	for (; ill != NULL; ill = ill_next(&ctx, ill))
		(void) ill_forward_set(ill, new_value != 0);

	rw_exit(&ipst->ips_ill_g_lock);
	return (0);
}

/*
 * Walk through the param array specified registering each element with the
 * Named Dispatch handler. This is called only during init. So it is ok
 * not to acquire any locks
 */
static boolean_t
ip_param_register(IDP *ndp, ipparam_t *ippa, size_t ippa_cnt,
    ipndp_t *ipnd, size_t ipnd_cnt)
{
	for (; ippa_cnt-- > 0; ippa++) {
		if (ippa->ip_param_name && ippa->ip_param_name[0]) {
			if (!nd_load(ndp, ippa->ip_param_name,
			    ip_param_get, ip_param_set, (caddr_t)ippa)) {
				nd_free(ndp);
				return (B_FALSE);
			}
		}
	}

	for (; ipnd_cnt-- > 0; ipnd++) {
		if (ipnd->ip_ndp_name && ipnd->ip_ndp_name[0]) {
			if (!nd_load(ndp, ipnd->ip_ndp_name,
			    ipnd->ip_ndp_getf, ipnd->ip_ndp_setf,
			    ipnd->ip_ndp_data)) {
				nd_free(ndp);
				return (B_FALSE);
			}
		}
	}

	return (B_TRUE);
}

/* Named Dispatch routine to negotiate a new value for one of our parameters. */
/* ARGSUSED */
static int
ip_param_set(queue_t *q, mblk_t *mp, char *value, caddr_t cp, cred_t *ioc_cr)
{
	long		new_value;
	ipparam_t	*ippa = (ipparam_t *)cp;

	if (ddi_strtol(value, NULL, 10, &new_value) != 0 ||
	    new_value < ippa->ip_param_min || new_value > ippa->ip_param_max) {
		return (EINVAL);
	}
	ippa->ip_param_value = new_value;
	return (0);
}

/*
 * Handles both IPv4 and IPv6 reassembly - doing the out-of-order cases,
 * When an ipf is passed here for the first time, if
 * we already have in-order fragments on the queue, we convert from the fast-
 * path reassembly scheme to the hard-case scheme.  From then on, additional
 * fragments are reassembled here.  We keep track of the start and end offsets
 * of each piece, and the number of holes in the chain.  When the hole count
 * goes to zero, we are done!
 *
 * The ipf_count will be updated to account for any mblk(s) added (pointed to
 * by mp) or subtracted (freeb()ed dups), upon return the caller must update
 * ipfb_count and ill_frag_count by the difference of ipf_count before and
 * after the call to ip_reassemble().
 */
int
ip_reassemble(mblk_t *mp, ipf_t *ipf, uint_t start, boolean_t more, ill_t *ill,
    size_t msg_len)
{
	uint_t	end;
	mblk_t	*next_mp;
	mblk_t	*mp1;
	uint_t	offset;
	boolean_t incr_dups = B_TRUE;
	boolean_t offset_zero_seen = B_FALSE;
	boolean_t pkt_boundary_checked = B_FALSE;

	/* If start == 0 then ipf_nf_hdr_len has to be set. */
	ASSERT(start != 0 || ipf->ipf_nf_hdr_len != 0);

	/* Add in byte count */
	ipf->ipf_count += msg_len;
	if (ipf->ipf_end) {
		/*
		 * We were part way through in-order reassembly, but now there
		 * is a hole.  We walk through messages already queued, and
		 * mark them for hard case reassembly.  We know that up till
		 * now they were in order starting from offset zero.
		 */
		offset = 0;
		for (mp1 = ipf->ipf_mp->b_cont; mp1; mp1 = mp1->b_cont) {
			IP_REASS_SET_START(mp1, offset);
			if (offset == 0) {
				ASSERT(ipf->ipf_nf_hdr_len != 0);
				offset = -ipf->ipf_nf_hdr_len;
			}
			offset += mp1->b_wptr - mp1->b_rptr;
			IP_REASS_SET_END(mp1, offset);
		}
		/* One hole at the end. */
		ipf->ipf_hole_cnt = 1;
		/* Brand it as a hard case, forever. */
		ipf->ipf_end = 0;
	}
	/* Walk through all the new pieces. */
	do {
		end = start + (mp->b_wptr - mp->b_rptr);
		/*
		 * If start is 0, decrease 'end' only for the first mblk of
		 * the fragment. Otherwise 'end' can get wrong value in the
		 * second pass of the loop if first mblk is exactly the
		 * size of ipf_nf_hdr_len.
		 */
		if (start == 0 && !offset_zero_seen) {
			/* First segment */
			ASSERT(ipf->ipf_nf_hdr_len != 0);
			end -= ipf->ipf_nf_hdr_len;
			offset_zero_seen = B_TRUE;
		}
		next_mp = mp->b_cont;
		/*
		 * We are checking to see if there is any interesing data
		 * to process.  If there isn't and the mblk isn't the
		 * one which carries the unfragmentable header then we
		 * drop it.  It's possible to have just the unfragmentable
		 * header come through without any data.  That needs to be
		 * saved.
		 *
		 * If the assert at the top of this function holds then the
		 * term "ipf->ipf_nf_hdr_len != 0" isn't needed.  This code
		 * is infrequently traveled enough that the test is left in
		 * to protect against future code changes which break that
		 * invariant.
		 */
		if (start == end && start != 0 && ipf->ipf_nf_hdr_len != 0) {
			/* Empty.  Blast it. */
			IP_REASS_SET_START(mp, 0);
			IP_REASS_SET_END(mp, 0);
			/*
			 * If the ipf points to the mblk we are about to free,
			 * update ipf to point to the next mblk (or NULL
			 * if none).
			 */
			if (ipf->ipf_mp->b_cont == mp)
				ipf->ipf_mp->b_cont = next_mp;
			freeb(mp);
			continue;
		}
		mp->b_cont = NULL;
		IP_REASS_SET_START(mp, start);
		IP_REASS_SET_END(mp, end);
		if (!ipf->ipf_tail_mp) {
			ipf->ipf_tail_mp = mp;
			ipf->ipf_mp->b_cont = mp;
			if (start == 0 || !more) {
				ipf->ipf_hole_cnt = 1;
				/*
				 * if the first fragment comes in more than one
				 * mblk, this loop will be executed for each
				 * mblk. Need to adjust hole count so exiting
				 * this routine will leave hole count at 1.
				 */
				if (next_mp)
					ipf->ipf_hole_cnt++;
			} else
				ipf->ipf_hole_cnt = 2;
			continue;
		} else if (ipf->ipf_last_frag_seen && !more &&
		    !pkt_boundary_checked) {
			/*
			 * We check datagram boundary only if this fragment
			 * claims to be the last fragment and we have seen a
			 * last fragment in the past too. We do this only
			 * once for a given fragment.
			 *
			 * start cannot be 0 here as fragments with start=0
			 * and MF=0 gets handled as a complete packet. These
			 * fragments should not reach here.
			 */

			if (start + msgdsize(mp) !=
			    IP_REASS_END(ipf->ipf_tail_mp)) {
				/*
				 * We have two fragments both of which claim
				 * to be the last fragment but gives conflicting
				 * information about the whole datagram size.
				 * Something fishy is going on. Drop the
				 * fragment and free up the reassembly list.
				 */
				return (IP_REASS_FAILED);
			}

			/*
			 * We shouldn't come to this code block again for this
			 * particular fragment.
			 */
			pkt_boundary_checked = B_TRUE;
		}

		/* New stuff at or beyond tail? */
		offset = IP_REASS_END(ipf->ipf_tail_mp);
		if (start >= offset) {
			if (ipf->ipf_last_frag_seen) {
				/* current fragment is beyond last fragment */
				return (IP_REASS_FAILED);
			}
			/* Link it on end. */
			ipf->ipf_tail_mp->b_cont = mp;
			ipf->ipf_tail_mp = mp;
			if (more) {
				if (start != offset)
					ipf->ipf_hole_cnt++;
			} else if (start == offset && next_mp == NULL)
					ipf->ipf_hole_cnt--;
			continue;
		}
		mp1 = ipf->ipf_mp->b_cont;
		offset = IP_REASS_START(mp1);
		/* New stuff at the front? */
		if (start < offset) {
			if (start == 0) {
				if (end >= offset) {
					/* Nailed the hole at the begining. */
					ipf->ipf_hole_cnt--;
				}
			} else if (end < offset) {
				/*
				 * A hole, stuff, and a hole where there used
				 * to be just a hole.
				 */
				ipf->ipf_hole_cnt++;
			}
			mp->b_cont = mp1;
			/* Check for overlap. */
			while (end > offset) {
				if (end < IP_REASS_END(mp1)) {
					mp->b_wptr -= end - offset;
					IP_REASS_SET_END(mp, offset);
					BUMP_MIB(ill->ill_ip_mib,
					    ipIfStatsReasmPartDups);
					break;
				}
				/* Did we cover another hole? */
				if ((mp1->b_cont &&
				    IP_REASS_END(mp1) !=
				    IP_REASS_START(mp1->b_cont) &&
				    end >= IP_REASS_START(mp1->b_cont)) ||
				    (!ipf->ipf_last_frag_seen && !more)) {
					ipf->ipf_hole_cnt--;
				}
				/* Clip out mp1. */
				if ((mp->b_cont = mp1->b_cont) == NULL) {
					/*
					 * After clipping out mp1, this guy
					 * is now hanging off the end.
					 */
					ipf->ipf_tail_mp = mp;
				}
				IP_REASS_SET_START(mp1, 0);
				IP_REASS_SET_END(mp1, 0);
				/* Subtract byte count */
				ipf->ipf_count -= mp1->b_datap->db_lim -
				    mp1->b_datap->db_base;
				freeb(mp1);
				BUMP_MIB(ill->ill_ip_mib,
				    ipIfStatsReasmPartDups);
				mp1 = mp->b_cont;
				if (!mp1)
					break;
				offset = IP_REASS_START(mp1);
			}
			ipf->ipf_mp->b_cont = mp;
			continue;
		}
		/*
		 * The new piece starts somewhere between the start of the head
		 * and before the end of the tail.
		 */
		for (; mp1; mp1 = mp1->b_cont) {
			offset = IP_REASS_END(mp1);
			if (start < offset) {
				if (end <= offset) {
					/* Nothing new. */
					IP_REASS_SET_START(mp, 0);
					IP_REASS_SET_END(mp, 0);
					/* Subtract byte count */
					ipf->ipf_count -= mp->b_datap->db_lim -
					    mp->b_datap->db_base;
					if (incr_dups) {
						ipf->ipf_num_dups++;
						incr_dups = B_FALSE;
					}
					freeb(mp);
					BUMP_MIB(ill->ill_ip_mib,
					    ipIfStatsReasmDuplicates);
					break;
				}
				/*
				 * Trim redundant stuff off beginning of new
				 * piece.
				 */
				IP_REASS_SET_START(mp, offset);
				mp->b_rptr += offset - start;
				BUMP_MIB(ill->ill_ip_mib,
				    ipIfStatsReasmPartDups);
				start = offset;
				if (!mp1->b_cont) {
					/*
					 * After trimming, this guy is now
					 * hanging off the end.
					 */
					mp1->b_cont = mp;
					ipf->ipf_tail_mp = mp;
					if (!more) {
						ipf->ipf_hole_cnt--;
					}
					break;
				}
			}
			if (start >= IP_REASS_START(mp1->b_cont))
				continue;
			/* Fill a hole */
			if (start > offset)
				ipf->ipf_hole_cnt++;
			mp->b_cont = mp1->b_cont;
			mp1->b_cont = mp;
			mp1 = mp->b_cont;
			offset = IP_REASS_START(mp1);
			if (end >= offset) {
				ipf->ipf_hole_cnt--;
				/* Check for overlap. */
				while (end > offset) {
					if (end < IP_REASS_END(mp1)) {
						mp->b_wptr -= end - offset;
						IP_REASS_SET_END(mp, offset);
						/*
						 * TODO we might bump
						 * this up twice if there is
						 * overlap at both ends.
						 */
						BUMP_MIB(ill->ill_ip_mib,
						    ipIfStatsReasmPartDups);
						break;
					}
					/* Did we cover another hole? */
					if ((mp1->b_cont &&
					    IP_REASS_END(mp1)
					    != IP_REASS_START(mp1->b_cont) &&
					    end >=
					    IP_REASS_START(mp1->b_cont)) ||
					    (!ipf->ipf_last_frag_seen &&
					    !more)) {
						ipf->ipf_hole_cnt--;
					}
					/* Clip out mp1. */
					if ((mp->b_cont = mp1->b_cont) ==
					    NULL) {
						/*
						 * After clipping out mp1,
						 * this guy is now hanging
						 * off the end.
						 */
						ipf->ipf_tail_mp = mp;
					}
					IP_REASS_SET_START(mp1, 0);
					IP_REASS_SET_END(mp1, 0);
					/* Subtract byte count */
					ipf->ipf_count -=
					    mp1->b_datap->db_lim -
					    mp1->b_datap->db_base;
					freeb(mp1);
					BUMP_MIB(ill->ill_ip_mib,
					    ipIfStatsReasmPartDups);
					mp1 = mp->b_cont;
					if (!mp1)
						break;
					offset = IP_REASS_START(mp1);
				}
			}
			break;
		}
	} while (start = end, mp = next_mp);

	/* Fragment just processed could be the last one. Remember this fact */
	if (!more)
		ipf->ipf_last_frag_seen = B_TRUE;

	/* Still got holes? */
	if (ipf->ipf_hole_cnt)
		return (IP_REASS_PARTIAL);
	/* Clean up overloaded fields to avoid upstream disasters. */
	for (mp1 = ipf->ipf_mp->b_cont; mp1; mp1 = mp1->b_cont) {
		IP_REASS_SET_START(mp1, 0);
		IP_REASS_SET_END(mp1, 0);
	}
	return (IP_REASS_COMPLETE);
}

/*
 * Fragmentation reassembly.  Each ILL has a hash table for
 * queuing packets undergoing reassembly for all IPIFs
 * associated with the ILL.  The hash is based on the packet
 * IP ident field.  The ILL frag hash table was allocated
 * as a timer block at the time the ILL was created.  Whenever
 * there is anything on the reassembly queue, the timer will
 * be running.  Returns the reassembled packet if reassembly completes.
 */
mblk_t *
ip_input_fragment(mblk_t *mp, ipha_t *ipha, ip_recv_attr_t *ira)
{
	uint32_t	frag_offset_flags;
	mblk_t		*t_mp;
	ipaddr_t	dst;
	uint8_t		proto = ipha->ipha_protocol;
	uint32_t	sum_val;
	uint16_t	sum_flags;
	ipf_t		*ipf;
	ipf_t		**ipfp;
	ipfb_t		*ipfb;
	uint16_t	ident;
	uint32_t	offset;
	ipaddr_t	src;
	uint_t		hdr_length;
	uint32_t	end;
	mblk_t		*mp1;
	mblk_t		*tail_mp;
	size_t		count;
	size_t		msg_len;
	uint8_t		ecn_info = 0;
	uint32_t	packet_size;
	boolean_t	pruned = B_FALSE;
	ill_t		*ill = ira->ira_ill;
	ip_stack_t	*ipst = ill->ill_ipst;

	/*
	 * Drop the fragmented as early as possible, if
	 * we don't have resource(s) to re-assemble.
	 */
	if (ipst->ips_ip_reass_queue_bytes == 0) {
		freemsg(mp);
		return (NULL);
	}

	/* Check for fragmentation offset; return if there's none */
	if ((frag_offset_flags = ntohs(ipha->ipha_fragment_offset_and_flags) &
	    (IPH_MF | IPH_OFFSET)) == 0)
		return (mp);

	/*
	 * We utilize hardware computed checksum info only for UDP since
	 * IP fragmentation is a normal occurrence for the protocol.  In
	 * addition, checksum offload support for IP fragments carrying
	 * UDP payload is commonly implemented across network adapters.
	 */
	ASSERT(ira->ira_rill != NULL);
	if (proto == IPPROTO_UDP && dohwcksum &&
	    ILL_HCKSUM_CAPABLE(ira->ira_rill) &&
	    (DB_CKSUMFLAGS(mp) & (HCK_FULLCKSUM | HCK_PARTIALCKSUM))) {
		mblk_t *mp1 = mp->b_cont;
		int32_t len;

		/* Record checksum information from the packet */
		sum_val = (uint32_t)DB_CKSUM16(mp);
		sum_flags = DB_CKSUMFLAGS(mp);

		/* IP payload offset from beginning of mblk */
		offset = ((uchar_t *)ipha + IPH_HDR_LENGTH(ipha)) - mp->b_rptr;

		if ((sum_flags & HCK_PARTIALCKSUM) &&
		    (mp1 == NULL || mp1->b_cont == NULL) &&
		    offset >= DB_CKSUMSTART(mp) &&
		    ((len = offset - DB_CKSUMSTART(mp)) & 1) == 0) {
			uint32_t adj;
			/*
			 * Partial checksum has been calculated by hardware
			 * and attached to the packet; in addition, any
			 * prepended extraneous data is even byte aligned.
			 * If any such data exists, we adjust the checksum;
			 * this would also handle any postpended data.
			 */
			IP_ADJCKSUM_PARTIAL(mp->b_rptr + DB_CKSUMSTART(mp),
			    mp, mp1, len, adj);

			/* One's complement subtract extraneous checksum */
			if (adj >= sum_val)
				sum_val = ~(adj - sum_val) & 0xFFFF;
			else
				sum_val -= adj;
		}
	} else {
		sum_val = 0;
		sum_flags = 0;
	}

	/* Clear hardware checksumming flag */
	DB_CKSUMFLAGS(mp) = 0;

	ident = ipha->ipha_ident;
	offset = (frag_offset_flags << 3) & 0xFFFF;
	src = ipha->ipha_src;
	dst = ipha->ipha_dst;
	hdr_length = IPH_HDR_LENGTH(ipha);
	end = ntohs(ipha->ipha_length) - hdr_length;

	/* If end == 0 then we have a packet with no data, so just free it */
	if (end == 0) {
		freemsg(mp);
		return (NULL);
	}

	/* Record the ECN field info. */
	ecn_info = (ipha->ipha_type_of_service & 0x3);
	if (offset != 0) {
		/*
		 * If this isn't the first piece, strip the header, and
		 * add the offset to the end value.
		 */
		mp->b_rptr += hdr_length;
		end += offset;
	}

	/* Handle vnic loopback of fragments */
	if (mp->b_datap->db_ref > 2)
		msg_len = 0;
	else
		msg_len = MBLKSIZE(mp);

	tail_mp = mp;
	while (tail_mp->b_cont != NULL) {
		tail_mp = tail_mp->b_cont;
		if (tail_mp->b_datap->db_ref <= 2)
			msg_len += MBLKSIZE(tail_mp);
	}

	/* If the reassembly list for this ILL will get too big, prune it */
	if ((msg_len + sizeof (*ipf) + ill->ill_frag_count) >=
	    ipst->ips_ip_reass_queue_bytes) {
		DTRACE_PROBE3(ip_reass_queue_bytes, uint_t, msg_len,
		    uint_t, ill->ill_frag_count,
		    uint_t, ipst->ips_ip_reass_queue_bytes);
		ill_frag_prune(ill,
		    (ipst->ips_ip_reass_queue_bytes < msg_len) ? 0 :
		    (ipst->ips_ip_reass_queue_bytes - msg_len));
		pruned = B_TRUE;
	}

	ipfb = &ill->ill_frag_hash_tbl[ILL_FRAG_HASH(src, ident)];
	mutex_enter(&ipfb->ipfb_lock);

	ipfp = &ipfb->ipfb_ipf;
	/* Try to find an existing fragment queue for this packet. */
	for (;;) {
		ipf = ipfp[0];
		if (ipf != NULL) {
			/*
			 * It has to match on ident and src/dst address.
			 */
			if (ipf->ipf_ident == ident &&
			    ipf->ipf_src == src &&
			    ipf->ipf_dst == dst &&
			    ipf->ipf_protocol == proto) {
				/*
				 * If we have received too many
				 * duplicate fragments for this packet
				 * free it.
				 */
				if (ipf->ipf_num_dups > ip_max_frag_dups) {
					ill_frag_free_pkts(ill, ipfb, ipf, 1);
					freemsg(mp);
					mutex_exit(&ipfb->ipfb_lock);
					return (NULL);
				}
				/* Found it. */
				break;
			}
			ipfp = &ipf->ipf_hash_next;
			continue;
		}

		/*
		 * If we pruned the list, do we want to store this new
		 * fragment?. We apply an optimization here based on the
		 * fact that most fragments will be received in order.
		 * So if the offset of this incoming fragment is zero,
		 * it is the first fragment of a new packet. We will
		 * keep it.  Otherwise drop the fragment, as we have
		 * probably pruned the packet already (since the
		 * packet cannot be found).
		 */
		if (pruned && offset != 0) {
			mutex_exit(&ipfb->ipfb_lock);
			freemsg(mp);
			return (NULL);
		}

		if (ipfb->ipfb_frag_pkts >= MAX_FRAG_PKTS(ipst))  {
			/*
			 * Too many fragmented packets in this hash
			 * bucket. Free the oldest.
			 */
			ill_frag_free_pkts(ill, ipfb, ipfb->ipfb_ipf, 1);
		}

		/* New guy.  Allocate a frag message. */
		mp1 = allocb(sizeof (*ipf), BPRI_MED);
		if (mp1 == NULL) {
			BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
			ip_drop_input("ipIfStatsInDiscards", mp, ill);
			freemsg(mp);
reass_done:
			mutex_exit(&ipfb->ipfb_lock);
			return (NULL);
		}

		BUMP_MIB(ill->ill_ip_mib, ipIfStatsReasmReqds);
		mp1->b_cont = mp;

		/* Initialize the fragment header. */
		ipf = (ipf_t *)mp1->b_rptr;
		ipf->ipf_mp = mp1;
		ipf->ipf_ptphn = ipfp;
		ipfp[0] = ipf;
		ipf->ipf_hash_next = NULL;
		ipf->ipf_ident = ident;
		ipf->ipf_protocol = proto;
		ipf->ipf_src = src;
		ipf->ipf_dst = dst;
		ipf->ipf_nf_hdr_len = 0;
		/* Record reassembly start time. */
		ipf->ipf_timestamp = gethrestime_sec();
		/* Record ipf generation and account for frag header */
		ipf->ipf_gen = ill->ill_ipf_gen++;
		ipf->ipf_count = MBLKSIZE(mp1);
		ipf->ipf_last_frag_seen = B_FALSE;
		ipf->ipf_ecn = ecn_info;
		ipf->ipf_num_dups = 0;
		ipfb->ipfb_frag_pkts++;
		ipf->ipf_checksum = 0;
		ipf->ipf_checksum_flags = 0;

		/* Store checksum value in fragment header */
		if (sum_flags != 0) {
			sum_val = (sum_val & 0xFFFF) + (sum_val >> 16);
			sum_val = (sum_val & 0xFFFF) + (sum_val >> 16);
			ipf->ipf_checksum = sum_val;
			ipf->ipf_checksum_flags = sum_flags;
		}

		/*
		 * We handle reassembly two ways.  In the easy case,
		 * where all the fragments show up in order, we do
		 * minimal bookkeeping, and just clip new pieces on
		 * the end.  If we ever see a hole, then we go off
		 * to ip_reassemble which has to mark the pieces and
		 * keep track of the number of holes, etc.  Obviously,
		 * the point of having both mechanisms is so we can
		 * handle the easy case as efficiently as possible.
		 */
		if (offset == 0) {
			/* Easy case, in-order reassembly so far. */
			ipf->ipf_count += msg_len;
			ipf->ipf_tail_mp = tail_mp;
			/*
			 * Keep track of next expected offset in
			 * ipf_end.
			 */
			ipf->ipf_end = end;
			ipf->ipf_nf_hdr_len = hdr_length;
		} else {
			/* Hard case, hole at the beginning. */
			ipf->ipf_tail_mp = NULL;
			/*
			 * ipf_end == 0 means that we have given up
			 * on easy reassembly.
			 */
			ipf->ipf_end = 0;

			/* Forget checksum offload from now on */
			ipf->ipf_checksum_flags = 0;

			/*
			 * ipf_hole_cnt is set by ip_reassemble.
			 * ipf_count is updated by ip_reassemble.
			 * No need to check for return value here
			 * as we don't expect reassembly to complete
			 * or fail for the first fragment itself.
			 */
			(void) ip_reassemble(mp, ipf,
			    (frag_offset_flags & IPH_OFFSET) << 3,
			    (frag_offset_flags & IPH_MF), ill, msg_len);
		}
		/* Update per ipfb and ill byte counts */
		ipfb->ipfb_count += ipf->ipf_count;
		ASSERT(ipfb->ipfb_count > 0);	/* Wraparound */
		atomic_add_32(&ill->ill_frag_count, ipf->ipf_count);
		/* If the frag timer wasn't already going, start it. */
		mutex_enter(&ill->ill_lock);
		ill_frag_timer_start(ill);
		mutex_exit(&ill->ill_lock);
		goto reass_done;
	}

	/*
	 * If the packet's flag has changed (it could be coming up
	 * from an interface different than the previous, therefore
	 * possibly different checksum capability), then forget about
	 * any stored checksum states.  Otherwise add the value to
	 * the existing one stored in the fragment header.
	 */
	if (sum_flags != 0 && sum_flags == ipf->ipf_checksum_flags) {
		sum_val += ipf->ipf_checksum;
		sum_val = (sum_val & 0xFFFF) + (sum_val >> 16);
		sum_val = (sum_val & 0xFFFF) + (sum_val >> 16);
		ipf->ipf_checksum = sum_val;
	} else if (ipf->ipf_checksum_flags != 0) {
		/* Forget checksum offload from now on */
		ipf->ipf_checksum_flags = 0;
	}

	/*
	 * We have a new piece of a datagram which is already being
	 * reassembled.  Update the ECN info if all IP fragments
	 * are ECN capable.  If there is one which is not, clear
	 * all the info.  If there is at least one which has CE
	 * code point, IP needs to report that up to transport.
	 */
	if (ecn_info != IPH_ECN_NECT && ipf->ipf_ecn != IPH_ECN_NECT) {
		if (ecn_info == IPH_ECN_CE)
			ipf->ipf_ecn = IPH_ECN_CE;
	} else {
		ipf->ipf_ecn = IPH_ECN_NECT;
	}
	if (offset && ipf->ipf_end == offset) {
		/* The new fragment fits at the end */
		ipf->ipf_tail_mp->b_cont = mp;
		/* Update the byte count */
		ipf->ipf_count += msg_len;
		/* Update per ipfb and ill byte counts */
		ipfb->ipfb_count += msg_len;
		ASSERT(ipfb->ipfb_count > 0);	/* Wraparound */
		atomic_add_32(&ill->ill_frag_count, msg_len);
		if (frag_offset_flags & IPH_MF) {
			/* More to come. */
			ipf->ipf_end = end;
			ipf->ipf_tail_mp = tail_mp;
			goto reass_done;
		}
	} else {
		/* Go do the hard cases. */
		int ret;

		if (offset == 0)
			ipf->ipf_nf_hdr_len = hdr_length;

		/* Save current byte count */
		count = ipf->ipf_count;
		ret = ip_reassemble(mp, ipf,
		    (frag_offset_flags & IPH_OFFSET) << 3,
		    (frag_offset_flags & IPH_MF), ill, msg_len);
		/* Count of bytes added and subtracted (freeb()ed) */
		count = ipf->ipf_count - count;
		if (count) {
			/* Update per ipfb and ill byte counts */
			ipfb->ipfb_count += count;
			ASSERT(ipfb->ipfb_count > 0); /* Wraparound */
			atomic_add_32(&ill->ill_frag_count, count);
		}
		if (ret == IP_REASS_PARTIAL) {
			goto reass_done;
		} else if (ret == IP_REASS_FAILED) {
			/* Reassembly failed. Free up all resources */
			ill_frag_free_pkts(ill, ipfb, ipf, 1);
			for (t_mp = mp; t_mp != NULL; t_mp = t_mp->b_cont) {
				IP_REASS_SET_START(t_mp, 0);
				IP_REASS_SET_END(t_mp, 0);
			}
			freemsg(mp);
			goto reass_done;
		}
		/* We will reach here iff 'ret' is IP_REASS_COMPLETE */
	}
	/*
	 * We have completed reassembly.  Unhook the frag header from
	 * the reassembly list.
	 *
	 * Before we free the frag header, record the ECN info
	 * to report back to the transport.
	 */
	ecn_info = ipf->ipf_ecn;
	BUMP_MIB(ill->ill_ip_mib, ipIfStatsReasmOKs);
	ipfp = ipf->ipf_ptphn;

	/* We need to supply these to caller */
	if ((sum_flags = ipf->ipf_checksum_flags) != 0)
		sum_val = ipf->ipf_checksum;
	else
		sum_val = 0;

	mp1 = ipf->ipf_mp;
	count = ipf->ipf_count;
	ipf = ipf->ipf_hash_next;
	if (ipf != NULL)
		ipf->ipf_ptphn = ipfp;
	ipfp[0] = ipf;
	atomic_add_32(&ill->ill_frag_count, -count);
	ASSERT(ipfb->ipfb_count >= count);
	ipfb->ipfb_count -= count;
	ipfb->ipfb_frag_pkts--;
	mutex_exit(&ipfb->ipfb_lock);
	/* Ditch the frag header. */
	mp = mp1->b_cont;

	freeb(mp1);

	/* Restore original IP length in header. */
	packet_size = (uint32_t)msgdsize(mp);
	if (packet_size > IP_MAXPACKET) {
		BUMP_MIB(ill->ill_ip_mib, ipIfStatsInHdrErrors);
		ip_drop_input("Reassembled packet too large", mp, ill);
		freemsg(mp);
		return (NULL);
	}

	if (DB_REF(mp) > 1) {
		mblk_t *mp2 = copymsg(mp);

		if (mp2 == NULL) {
			BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
			ip_drop_input("ipIfStatsInDiscards", mp, ill);
			freemsg(mp);
			return (NULL);
		}
		freemsg(mp);
		mp = mp2;
	}
	ipha = (ipha_t *)mp->b_rptr;

	ipha->ipha_length = htons((uint16_t)packet_size);
	/* We're now complete, zip the frag state */
	ipha->ipha_fragment_offset_and_flags = 0;
	/* Record the ECN info. */
	ipha->ipha_type_of_service &= 0xFC;
	ipha->ipha_type_of_service |= ecn_info;

	/* Update the receive attributes */
	ira->ira_pktlen = packet_size;
	ira->ira_ip_hdr_length = IPH_HDR_LENGTH(ipha);

	/* Reassembly is successful; set checksum information in packet */
	DB_CKSUM16(mp) = (uint16_t)sum_val;
	DB_CKSUMFLAGS(mp) = sum_flags;
	DB_CKSUMSTART(mp) = ira->ira_ip_hdr_length;

	return (mp);
}

/*
 * Pullup function that should be used for IP input in order to
 * ensure we do not loose the L2 source address; we need the l2 source
 * address for IP_RECVSLLA and for ndp_input.
 *
 * We return either NULL or b_rptr.
 */
void *
ip_pullup(mblk_t *mp, ssize_t len, ip_recv_attr_t *ira)
{
	ill_t		*ill = ira->ira_ill;

	if (ip_rput_pullups++ == 0) {
		(void) m