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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 
     22 /*
     23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 #include <sys/types.h>
     28 #include <inet/ip.h>
     29 #include <inet/ip_impl.h>
     30 #include <inet/ipclassifier.h>
     31 #include <inet/proto_set.h>
     32 #include <sys/stream.h>
     33 #include <sys/strsubr.h>
     34 #include <sys/strsun.h>
     35 #include <sys/cmn_err.h>
     36 #include <sys/t_kuser.h>
     37 #include <sys/tihdr.h>
     38 #include <sys/pathname.h>
     39 #include <sys/sockio.h>
     40 #include <sys/vmem.h>
     41 #include <sys/disp.h>
     42 
     43 void ip_helper_wput(queue_t *q, mblk_t *mp);
     44 
     45 static int ip_helper_stream_close(queue_t *, int);
     46 
     47 static struct module_info ip_helper_stream_info =  {
     48 	0, "iphelper", IP_MOD_MINPSZ, IP_MOD_MAXPSZ, IP_MOD_HIWAT, IP_MOD_LOWAT
     49 };
     50 
     51 static struct qinit ip_helper_stream_rinit = {
     52 	NULL, NULL, NULL, ip_helper_stream_close, NULL,
     53 	&ip_helper_stream_info, NULL
     54 };
     55 
     56 static struct qinit ip_helper_stream_winit = {
     57 	(pfi_t)ip_helper_wput, (pfi_t)ip_wsrv, NULL, NULL, NULL,
     58 	&ip_helper_stream_info, NULL, NULL, NULL, STRUIOT_NONE
     59 };
     60 
     61 /*
     62  * set the q_ptr of the 'q' to the conn_t pointer passed in
     63  */
     64 static void
     65 ip_helper_share_conn(queue_t *q, mblk_t *mp, cred_t *crp)
     66 {
     67 	conn_t *connp = *((conn_t **)mp->b_cont->b_rptr);
     68 
     69 	/*
     70 	 * This operation is allowed only on helper streams with kcred
     71 	 */
     72 
     73 	if (kcred != crp || msgdsize(mp->b_cont) != sizeof (void *)) {
     74 		miocnak(q, mp, 0, EINVAL);
     75 		return;
     76 	}
     77 
     78 	connp->conn_helper_info->iphs_minfo = q->q_ptr;
     79 	connp->conn_helper_info->iphs_rq = RD(q);
     80 	connp->conn_helper_info->iphs_wq = WR(q);
     81 	WR(q)->q_ptr = RD(q)->q_ptr = (void *)connp;
     82 	connp->conn_rq = RD(q);
     83 	connp->conn_wq = WR(q);
     84 	miocack(q, mp, 0, 0);
     85 }
     86 
     87 void
     88 ip_helper_wput(queue_t *q, mblk_t *mp)
     89 {
     90 	struct iocblk *iocp = (struct iocblk *)mp->b_rptr;
     91 	if (DB_TYPE(mp) == M_IOCTL &&
     92 	    iocp->ioc_cmd == SIOCSQPTR) {
     93 		ip_helper_share_conn(q, mp, iocp->ioc_cr);
     94 	} else {
     95 		/* We only handle ioctl related messages here */
     96 		ASSERT(DB_TYPE(mp) != M_DATA);
     97 		ip_wput_nondata(q, mp);
     98 	}
     99 }
    100 
    101 /* ARGSUSED3 */
    102 int
    103 ip_helper_stream_setup(queue_t *q, dev_t *devp, int flag, int sflag,
    104     cred_t *credp, boolean_t isv6)
    105 {
    106 	major_t			maj;
    107 	ip_helper_minfo_t	*ip_minfop;
    108 
    109 	ASSERT((flag & ~(FKLYR)) == IP_HELPER_STR);
    110 
    111 	ASSERT(RD(q) == q);
    112 
    113 	ip_minfop = kmem_alloc(sizeof (ip_helper_minfo_t), KM_SLEEP);
    114 	ASSERT(ip_minfop != NULL);
    115 
    116 	ip_minfop->ip_minfo_dev = 0;
    117 	ip_minfop->ip_minfo_arena = NULL;
    118 
    119 	/*
    120 	 * Clone the device, allocate minor device number
    121 	 */
    122 	if (ip_minor_arena_la != NULL)
    123 		ip_minfop->ip_minfo_dev = inet_minor_alloc(ip_minor_arena_la);
    124 
    125 	if (ip_minfop->ip_minfo_dev == 0) {
    126 		/*
    127 		 * numbers in the large arena are exhausted
    128 		 * Try small arena.
    129 		 * Or this is a 32 bit system, 32 bit systems do not have
    130 		 * ip_minor_arena_la
    131 		 */
    132 		ip_minfop->ip_minfo_dev = inet_minor_alloc(ip_minor_arena_sa);
    133 		if (ip_minfop->ip_minfo_dev == 0) {
    134 			return (EBUSY);
    135 		}
    136 		ip_minfop->ip_minfo_arena = ip_minor_arena_sa;
    137 	} else {
    138 		ip_minfop->ip_minfo_arena = ip_minor_arena_la;
    139 	}
    140 
    141 
    142 	ASSERT(ip_minfop->ip_minfo_dev != 0);
    143 	ASSERT(ip_minfop->ip_minfo_arena != NULL);
    144 
    145 	RD(q)->q_ptr = WR(q)->q_ptr = ip_minfop;
    146 
    147 	maj = getemajor(*devp);
    148 	*devp = makedevice(maj, (ulong_t)(ip_minfop->ip_minfo_dev));
    149 
    150 	q->q_qinfo = &ip_helper_stream_rinit;
    151 	WR(q)->q_qinfo = &ip_helper_stream_winit;
    152 	qprocson(q);
    153 	return (0);
    154 }
    155 
    156 /* ARGSUSED1 */
    157 static int
    158 ip_helper_stream_close(queue_t *q, int flag)
    159 {
    160 	ip_helper_minfo_t *ip_minfop;
    161 
    162 	qprocsoff(q);
    163 	ip_minfop = (q)->q_ptr;
    164 	inet_minor_free(ip_minfop->ip_minfo_arena,
    165 	    ip_minfop->ip_minfo_dev);
    166 	kmem_free(ip_minfop, sizeof (ip_helper_minfo_t));
    167 	RD(q)->q_ptr = NULL;
    168 	WR(q)->q_ptr = NULL;
    169 	return (0);
    170 }
    171 
    172 /*
    173  * Public interface for creating an IP stream with shared conn_t
    174  * Handles multiple callers in parallel by using conn_lock.
    175  * Note that we allocate the helper stream without any locks, which means
    176  * we might need to free it if we had two threads doing this concurrently
    177  * for the conn_t.
    178  */
    179 int
    180 ip_create_helper_stream(conn_t *connp, ldi_ident_t li)
    181 {
    182 	ip_helper_stream_info_t *helper;
    183 	int	error;
    184 	int	ret;
    185 
    186 	ASSERT(!servicing_interrupt());
    187 
    188 	if (connp->conn_helper_info != NULL) {
    189 		/* Already allocated */
    190 		return (0);
    191 	}
    192 
    193 	error = 0;
    194 	helper = kmem_alloc(sizeof (ip_helper_stream_info_t), KM_SLEEP);
    195 
    196 	/*
    197 	 * open ip device via the layered interface.
    198 	 * pass in kcred as some threads do not have the
    199 	 * priviledge to open /dev/ip and the check in
    200 	 * secpolicy_spec_open() will fail the open
    201 	 */
    202 	error = ldi_open_by_name((connp->conn_family == AF_INET6 ? DEV_IP6 :
    203 	    DEV_IP), IP_HELPER_STR, kcred, &helper->iphs_handle, li);
    204 
    205 	if (error != 0) {
    206 		kmem_free(helper, sizeof (ip_helper_stream_info_t));
    207 		return (error);
    208 	}
    209 	/* Make sure we are the only one */
    210 	mutex_enter(&connp->conn_lock);
    211 	if (connp->conn_helper_info != NULL) {
    212 		/* Some other thread won - discard this stream */
    213 		mutex_exit(&connp->conn_lock);
    214 		(void) ldi_close(helper->iphs_handle, 0, kcred);
    215 		kmem_free(helper, sizeof (ip_helper_stream_info_t));
    216 		return (0);
    217 	}
    218 	connp->conn_helper_info = helper;
    219 	/*
    220 	 * Share connp with the helper stream. We hold conn_lock across this
    221 	 * operation.
    222 	 */
    223 	error = ldi_ioctl(helper->iphs_handle, SIOCSQPTR, (intptr_t)connp,
    224 	    FKIOCTL, kcred, &ret);
    225 
    226 	if (error != 0) {
    227 		/*
    228 		 * Passing in a zero flag indicates that an error
    229 		 * occured and stream was not shared
    230 		 */
    231 		(void) ldi_close(helper->iphs_handle, 0, kcred);
    232 		kmem_free(helper, sizeof (ip_helper_stream_info_t));
    233 		connp->conn_helper_info = NULL;
    234 	}
    235 	mutex_exit(&connp->conn_lock);
    236 	return (error);
    237 }
    238 
    239 /*
    240  * Public interface for freeing IP helper stream
    241  * Caller must ensure no concurrent use of the conn_t, which is normally
    242  * done by calling this from the close routine when the conn_t is quiesced.
    243  */
    244 void
    245 ip_free_helper_stream(conn_t *connp)
    246 {
    247 	ASSERT(!servicing_interrupt());
    248 
    249 	if (connp->conn_helper_info == NULL)
    250 		return;
    251 
    252 	ASSERT(connp->conn_helper_info->iphs_handle != NULL);
    253 
    254 	connp->conn_helper_info->iphs_rq->q_ptr =
    255 	    connp->conn_helper_info->iphs_wq->q_ptr =
    256 	    connp->conn_helper_info->iphs_minfo;
    257 	(void) ldi_close(connp->conn_helper_info->iphs_handle,
    258 	    IP_HELPER_STR, kcred);
    259 	kmem_free(connp->conn_helper_info, sizeof (ip_helper_stream_info_t));
    260 	connp->conn_helper_info = NULL;
    261 }
    262