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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  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 
     26 #include <sys/types.h>
     27 #include <stdlib.h>
     28 #include <assert.h>
     29 #include <errno.h>
     30 #include <locale.h>
     31 #include <string.h>
     32 #include <unistd.h>
     33 #include <signal.h>
     34 #include <stdio.h>
     35 #include <stdio_ext.h>
     36 #include <dhcp_hostconf.h>
     37 #include <dhcpagent_ipc.h>
     38 #include <dhcpagent_util.h>
     39 #include <dhcpmsg.h>
     40 #include <netinet/dhcp.h>
     41 #include <net/route.h>
     42 #include <sys/sockio.h>
     43 #include <sys/stat.h>
     44 #include <stropts.h>
     45 #include <fcntl.h>
     46 #include <sys/scsi/adapters/iscsi_if.h>
     47 
     48 #include "async.h"
     49 #include "agent.h"
     50 #include "script_handler.h"
     51 #include "util.h"
     52 #include "class_id.h"
     53 #include "states.h"
     54 #include "packet.h"
     55 #include "interface.h"
     56 #include "defaults.h"
     57 
     58 #ifndef	TEXT_DOMAIN
     59 #define	TEXT_DOMAIN	"SYS_TEST"
     60 #endif
     61 
     62 iu_timer_id_t		inactivity_id;
     63 int			class_id_len = 0;
     64 char			*class_id;
     65 iu_eh_t			*eh;
     66 iu_tq_t			*tq;
     67 pid_t			grandparent;
     68 int			rtsock_fd;
     69 
     70 static boolean_t	shutdown_started = B_FALSE;
     71 static boolean_t	do_adopt = B_FALSE;
     72 static unsigned int	debug_level = 0;
     73 static iu_eh_callback_t	accept_event, ipc_event, rtsock_event;
     74 
     75 /*
     76  * The ipc_cmd_allowed[] table indicates which IPC commands are allowed in
     77  * which states; a non-zero value indicates the command is permitted.
     78  *
     79  * START is permitted if the state machine is fresh, or if we are in the
     80  * process of trying to obtain a lease (as a convenience to save the
     81  * administrator from having to do an explicit DROP).  EXTEND, RELEASE, and
     82  * GET_TAG require a lease to be obtained in order to make sense.  INFORM is
     83  * permitted if the interface is fresh or has an INFORM in progress or
     84  * previously done on it -- otherwise a DROP or RELEASE is first required.
     85  * PING and STATUS always make sense and thus are always permitted, as is DROP
     86  * in order to permit the administrator to always bail out.
     87  */
     88 static int ipc_cmd_allowed[DHCP_NSTATES][DHCP_NIPC] = {
     89 	/*			  D  E	P  R  S	 S  I  G */
     90 	/*			  R  X	I  E  T	 T  N  E */
     91 	/*			  O  T	N  L  A	 A  F  T */
     92 	/*			  P  E	G  E  R	 T  O  _ */
     93 	/*			  .  N  .  A  T  U  R  T */
     94 	/*			  .  D	.  S  .  S  M  A */
     95 	/*			  .  .  .  E  .  .  .  G */
     96 	/* INIT		*/	{ 1, 0, 1, 0, 1, 1, 1, 0 },
     97 	/* SELECTING	*/	{ 1, 0, 1, 0, 1, 1, 0, 0 },
     98 	/* REQUESTING	*/	{ 1, 0, 1, 0, 1, 1, 0, 0 },
     99 	/* PRE_BOUND	*/	{ 1, 1, 1, 1, 0, 1, 0, 1 },
    100 	/* BOUND	*/	{ 1, 1, 1, 1, 0, 1, 0, 1 },
    101 	/* RENEWING	*/	{ 1, 1, 1, 1, 0, 1, 0, 1 },
    102 	/* REBINDING	*/	{ 1, 1, 1, 1, 0, 1, 0, 1 },
    103 	/* INFORMATION  */	{ 1, 0, 1, 0, 1, 1, 1, 1 },
    104 	/* INIT_REBOOT  */	{ 1, 0, 1, 1, 1, 1, 0, 0 },
    105 	/* ADOPTING	*/	{ 1, 0, 1, 1, 0, 1, 0, 0 },
    106 	/* INFORM_SENT  */	{ 1, 0, 1, 0, 1, 1, 1, 0 },
    107 	/* DECLINING	*/	{ 1, 1, 1, 1, 0, 1, 0, 1 },
    108 	/* RELEASING	*/	{ 1, 0, 1, 0, 0, 1, 0, 1 },
    109 };
    110 
    111 #define	CMD_ISPRIV	0x1	/* Command requires privileges */
    112 #define	CMD_CREATE	0x2	/* Command creates an interface */
    113 #define	CMD_BOOTP	0x4	/* Command is valid with BOOTP */
    114 #define	CMD_IMMED	0x8	/* Reply is immediate (no BUSY state) */
    115 
    116 static uint_t ipc_cmd_flags[DHCP_NIPC] = {
    117 	/* DHCP_DROP */		CMD_ISPRIV|CMD_BOOTP,
    118 	/* DHCP_EXTEND */	CMD_ISPRIV,
    119 	/* DHCP_PING */		CMD_BOOTP|CMD_IMMED,
    120 	/* DHCP_RELEASE */	CMD_ISPRIV,
    121 	/* DHCP_START */	CMD_CREATE|CMD_ISPRIV|CMD_BOOTP,
    122 	/* DHCP_STATUS */	CMD_BOOTP|CMD_IMMED,
    123 	/* DHCP_INFORM */	CMD_CREATE|CMD_ISPRIV,
    124 	/* DHCP_GET_TAG */	CMD_BOOTP|CMD_IMMED
    125 };
    126 
    127 static boolean_t is_iscsi_active(void);
    128 
    129 int
    130 main(int argc, char **argv)
    131 {
    132 	boolean_t	is_daemon  = B_TRUE;
    133 	boolean_t	is_verbose;
    134 	int		ipc_fd;
    135 	int		c;
    136 	int		aware = RTAW_UNDER_IPMP;
    137 	struct rlimit	rl;
    138 
    139 	debug_level = df_get_int("", B_FALSE, DF_DEBUG_LEVEL);
    140 	is_verbose = df_get_bool("", B_FALSE, DF_VERBOSE);
    141 
    142 	/*
    143 	 * -l is ignored for compatibility with old agent.
    144 	 */
    145 
    146 	while ((c = getopt(argc, argv, "vd:l:fa")) != EOF) {
    147 
    148 		switch (c) {
    149 
    150 		case 'a':
    151 			do_adopt = B_TRUE;
    152 			grandparent = getpid();
    153 			break;
    154 
    155 		case 'd':
    156 			debug_level = strtoul(optarg, NULL, 0);
    157 			break;
    158 
    159 		case 'f':
    160 			is_daemon = B_FALSE;
    161 			break;
    162 
    163 		case 'v':
    164 			is_verbose = B_TRUE;
    165 			break;
    166 
    167 		case '?':
    168 			(void) fprintf(stderr, "usage: %s [-a] [-d n] [-f] [-v]"
    169 			    "\n", argv[0]);
    170 			return (EXIT_FAILURE);
    171 
    172 		default:
    173 			break;
    174 		}
    175 	}
    176 
    177 	(void) setlocale(LC_ALL, "");
    178 	(void) textdomain(TEXT_DOMAIN);
    179 
    180 	if (geteuid() != 0) {
    181 		dhcpmsg_init(argv[0], B_FALSE, is_verbose, debug_level);
    182 		dhcpmsg(MSG_ERROR, "must be super-user");
    183 		dhcpmsg_fini();
    184 		return (EXIT_FAILURE);
    185 	}
    186 
    187 	if (is_daemon && daemonize() == 0) {
    188 		dhcpmsg_init(argv[0], B_FALSE, is_verbose, debug_level);
    189 		dhcpmsg(MSG_ERR, "cannot become daemon, exiting");
    190 		dhcpmsg_fini();
    191 		return (EXIT_FAILURE);
    192 	}
    193 
    194 	/*
    195 	 * Seed the random number generator, since we're going to need it
    196 	 * to set transaction id's and for exponential backoff.
    197 	 */
    198 	srand48(gethrtime() ^ gethostid() ^ getpid());
    199 
    200 	dhcpmsg_init(argv[0], is_daemon, is_verbose, debug_level);
    201 	(void) atexit(dhcpmsg_fini);
    202 
    203 	tq = iu_tq_create();
    204 	eh = iu_eh_create();
    205 
    206 	if (eh == NULL || tq == NULL) {
    207 		errno = ENOMEM;
    208 		dhcpmsg(MSG_ERR, "cannot create timer queue or event handler");
    209 		return (EXIT_FAILURE);
    210 	}
    211 
    212 	/*
    213 	 * ignore most signals that could be reasonably generated.
    214 	 */
    215 
    216 	(void) signal(SIGTERM, graceful_shutdown);
    217 	(void) signal(SIGQUIT, graceful_shutdown);
    218 	(void) signal(SIGPIPE, SIG_IGN);
    219 	(void) signal(SIGUSR1, SIG_IGN);
    220 	(void) signal(SIGUSR2, SIG_IGN);
    221 	(void) signal(SIGINT,  SIG_IGN);
    222 	(void) signal(SIGHUP,  SIG_IGN);
    223 	(void) signal(SIGCHLD, SIG_IGN);
    224 
    225 	/*
    226 	 * upon SIGTHAW we need to refresh any non-infinite leases.
    227 	 */
    228 
    229 	(void) iu_eh_register_signal(eh, SIGTHAW, refresh_smachs, NULL);
    230 
    231 	class_id = get_class_id();
    232 	if (class_id != NULL)
    233 		class_id_len = strlen(class_id);
    234 	else
    235 		dhcpmsg(MSG_WARNING, "get_class_id failed, continuing "
    236 		    "with no vendor class id");
    237 
    238 	/*
    239 	 * the inactivity timer is enabled any time there are no
    240 	 * interfaces under DHCP control.  if DHCP_INACTIVITY_WAIT
    241 	 * seconds transpire without an interface under DHCP control,
    242 	 * the agent shuts down.
    243 	 */
    244 
    245 	inactivity_id = iu_schedule_timer(tq, DHCP_INACTIVITY_WAIT,
    246 	    inactivity_shutdown, NULL);
    247 
    248 	/*
    249 	 * max out the number available descriptors, just in case..
    250 	 */
    251 
    252 	rl.rlim_cur = RLIM_INFINITY;
    253 	rl.rlim_max = RLIM_INFINITY;
    254 	if (setrlimit(RLIMIT_NOFILE, &rl) == -1)
    255 		dhcpmsg(MSG_ERR, "setrlimit failed");
    256 
    257 	(void) enable_extended_FILE_stdio(-1, -1);
    258 
    259 	/*
    260 	 * Create and bind default IP sockets used to control interfaces and to
    261 	 * catch stray packets.
    262 	 */
    263 
    264 	if (!dhcp_ip_default())
    265 		return (EXIT_FAILURE);
    266 
    267 	/*
    268 	 * create the ipc channel that the agent will listen for
    269 	 * requests on, and register it with the event handler so that
    270 	 * `accept_event' will be called back.
    271 	 */
    272 
    273 	switch (dhcp_ipc_init(&ipc_fd)) {
    274 
    275 	case 0:
    276 		break;
    277 
    278 	case DHCP_IPC_E_BIND:
    279 		dhcpmsg(MSG_ERROR, "dhcp_ipc_init: cannot bind to port "
    280 		    "%i (agent already running?)", IPPORT_DHCPAGENT);
    281 		return (EXIT_FAILURE);
    282 
    283 	default:
    284 		dhcpmsg(MSG_ERROR, "dhcp_ipc_init failed");
    285 		return (EXIT_FAILURE);
    286 	}
    287 
    288 	if (iu_register_event(eh, ipc_fd, POLLIN, accept_event, 0) == -1) {
    289 		dhcpmsg(MSG_ERR, "cannot register ipc fd for messages");
    290 		return (EXIT_FAILURE);
    291 	}
    292 
    293 	/*
    294 	 * Create the global routing socket.  This is used for monitoring
    295 	 * interface transitions, so that we learn about the kernel's Duplicate
    296 	 * Address Detection status, and for inserting and removing default
    297 	 * routes as learned from DHCP servers.  Both v4 and v6 are handed
    298 	 * with this one socket.
    299 	 */
    300 	rtsock_fd = socket(PF_ROUTE, SOCK_RAW, 0);
    301 	if (rtsock_fd == -1) {
    302 		dhcpmsg(MSG_ERR, "cannot open routing socket");
    303 		return (EXIT_FAILURE);
    304 	}
    305 
    306 	/*
    307 	 * We're IPMP-aware and can manage IPMP test addresses, so issue
    308 	 * RT_AWARE to get routing socket messages for interfaces under IPMP.
    309 	 */
    310 	if (setsockopt(rtsock_fd, SOL_ROUTE, RT_AWARE, &aware,
    311 	    sizeof (aware)) == -1) {
    312 		dhcpmsg(MSG_ERR, "cannot set RT_AWARE on routing socket");
    313 		return (EXIT_FAILURE);
    314 	}
    315 
    316 	if (iu_register_event(eh, rtsock_fd, POLLIN, rtsock_event, 0) == -1) {
    317 		dhcpmsg(MSG_ERR, "cannot register routing socket for messages");
    318 		return (EXIT_FAILURE);
    319 	}
    320 
    321 	/*
    322 	 * if the -a (adopt) option was specified, try to adopt the
    323 	 * kernel-managed interface before we start.
    324 	 */
    325 
    326 	if (do_adopt && !dhcp_adopt())
    327 		return (EXIT_FAILURE);
    328 
    329 	/*
    330 	 * For DHCPv6, we own all of the interfaces marked DHCPRUNNING.  As
    331 	 * we're starting operation here, if there are any of those interfaces
    332 	 * lingering around, they're strays, and need to be removed.
    333 	 *
    334 	 * It might be nice to save these addresses off somewhere -- for both
    335 	 * v4 and v6 -- and use them as hints for later negotiation.
    336 	 */
    337 	remove_v6_strays();
    338 
    339 	/*
    340 	 * enter the main event loop; this is where all the real work
    341 	 * takes place (through registering events and scheduling timers).
    342 	 * this function only returns when the agent is shutting down.
    343 	 */
    344 
    345 	switch (iu_handle_events(eh, tq)) {
    346 
    347 	case -1:
    348 		dhcpmsg(MSG_WARNING, "iu_handle_events exited abnormally");
    349 		break;
    350 
    351 	case DHCP_REASON_INACTIVITY:
    352 		dhcpmsg(MSG_INFO, "no interfaces to manage, shutting down...");
    353 		break;
    354 
    355 	case DHCP_REASON_TERMINATE:
    356 		dhcpmsg(MSG_INFO, "received SIGTERM, shutting down...");
    357 		break;
    358 
    359 	case DHCP_REASON_SIGNAL:
    360 		dhcpmsg(MSG_WARNING, "received unexpected signal, shutting "
    361 		    "down...");
    362 		break;
    363 	}
    364 
    365 	(void) iu_eh_unregister_signal(eh, SIGTHAW, NULL);
    366 
    367 	iu_eh_destroy(eh);
    368 	iu_tq_destroy(tq);
    369 
    370 	return (EXIT_SUCCESS);
    371 }
    372 
    373 /*
    374  * drain_script(): event loop callback during shutdown
    375  *
    376  *   input: eh_t *: unused
    377  *	    void *: unused
    378  *  output: boolean_t: B_TRUE if event loop should exit; B_FALSE otherwise
    379  */
    380 
    381 /* ARGSUSED */
    382 boolean_t
    383 drain_script(iu_eh_t *ehp, void *arg)
    384 {
    385 	if (shutdown_started == B_FALSE) {
    386 		shutdown_started = B_TRUE;
    387 		/*
    388 		 * Check if the system is diskless client and/or
    389 		 * there are active iSCSI sessions
    390 		 *
    391 		 * Do not drop the lease, or the system will be
    392 		 * unable to sync(dump) through nfs/iSCSI driver
    393 		 */
    394 		if (!do_adopt && !is_iscsi_active()) {
    395 			nuke_smach_list();
    396 		}
    397 	}
    398 	return (script_count == 0);
    399 }
    400 
    401 /*
    402  * accept_event(): accepts a new connection on the ipc socket and registers
    403  *		   to receive its messages with the event handler
    404  *
    405  *   input: iu_eh_t *: unused
    406  *	    int: the file descriptor in the iu_eh_t * the connection came in on
    407  *	    (other arguments unused)
    408  *  output: void
    409  */
    410 
    411 /* ARGSUSED */
    412 static void
    413 accept_event(iu_eh_t *ehp, int fd, short events, iu_event_id_t id, void *arg)
    414 {
    415 	int	client_fd;
    416 	int	is_priv;
    417 
    418 	if (dhcp_ipc_accept(fd, &client_fd, &is_priv) != 0) {
    419 		dhcpmsg(MSG_ERR, "accept_event: accept on ipc socket");
    420 		return;
    421 	}
    422 
    423 	if (iu_register_event(eh, client_fd, POLLIN, ipc_event,
    424 	    (void *)is_priv) == -1) {
    425 		dhcpmsg(MSG_ERROR, "accept_event: cannot register ipc socket "
    426 		    "for callback");
    427 	}
    428 }
    429 
    430 /*
    431  * ipc_event(): processes incoming ipc requests
    432  *
    433  *   input: iu_eh_t *: unused
    434  *	    int: the file descriptor in the iu_eh_t * the request came in on
    435  *	    short: unused
    436  *	    iu_event_id_t: event ID
    437  *	    void *: indicates whether the request is from a privileged client
    438  *  output: void
    439  */
    440 
    441 /* ARGSUSED */
    442 static void
    443 ipc_event(iu_eh_t *ehp, int fd, short events, iu_event_id_t id, void *arg)
    444 {
    445 	ipc_action_t		ia, *iap;
    446 	dhcp_smach_t		*dsmp;
    447 	int			error, is_priv = (int)arg;
    448 	const char		*ifname;
    449 	boolean_t		isv6;
    450 	boolean_t		dsm_created = B_FALSE;
    451 
    452 	ipc_action_init(&ia);
    453 	error = dhcp_ipc_recv_request(fd, &ia.ia_request,
    454 	    DHCP_IPC_REQUEST_WAIT);
    455 	if (error != DHCP_IPC_SUCCESS) {
    456 		if (error != DHCP_IPC_E_EOF) {
    457 			dhcpmsg(MSG_ERROR,
    458 			    "ipc_event: dhcp_ipc_recv_request failed: %s",
    459 			    dhcp_ipc_strerror(error));
    460 		} else {
    461 			dhcpmsg(MSG_DEBUG, "ipc_event: connection closed");
    462 		}
    463 		if ((dsmp = lookup_smach_by_event(id)) != NULL) {
    464 			ipc_action_finish(dsmp, error);
    465 		} else {
    466 			(void) iu_unregister_event(eh, id, NULL);
    467 			(void) dhcp_ipc_close(fd);
    468 		}
    469 		return;
    470 	}
    471 
    472 	/* Fill in temporary ipc_action structure for utility functions */
    473 	ia.ia_cmd = DHCP_IPC_CMD(ia.ia_request->message_type);
    474 	ia.ia_fd = fd;
    475 	ia.ia_eid = id;
    476 
    477 	if (ia.ia_cmd >= DHCP_NIPC) {
    478 		dhcpmsg(MSG_ERROR,
    479 		    "ipc_event: invalid command (%s) attempted on %s",
    480 		    dhcp_ipc_type_to_string(ia.ia_cmd), ia.ia_request->ifname);
    481 		send_error_reply(&ia, DHCP_IPC_E_CMD_UNKNOWN);
    482 		return;
    483 	}
    484 
    485 	/* return EPERM for any of the privileged actions */
    486 
    487 	if (!is_priv && (ipc_cmd_flags[ia.ia_cmd] & CMD_ISPRIV)) {
    488 		dhcpmsg(MSG_WARNING,
    489 		    "ipc_event: privileged ipc command (%s) attempted on %s",
    490 		    dhcp_ipc_type_to_string(ia.ia_cmd), ia.ia_request->ifname);
    491 		send_error_reply(&ia, DHCP_IPC_E_PERM);
    492 		return;
    493 	}
    494 
    495 	/*
    496 	 * Try to locate the state machine associated with this command.  If
    497 	 * the command is DHCP_START or DHCP_INFORM and there isn't a state
    498 	 * machine already, make one (there may already be one from a previous
    499 	 * failed attempt to START or INFORM).  Otherwise, verify the reference
    500 	 * is still valid.
    501 	 *
    502 	 * The interface name may be blank.  In that case, we look up the
    503 	 * primary interface, and the requested type (v4 or v6) doesn't matter.
    504 	 */
    505 
    506 	isv6 = (ia.ia_request->message_type & DHCP_V6) != 0;
    507 	ifname = ia.ia_request->ifname;
    508 	if (*ifname == '\0')
    509 		dsmp = primary_smach(isv6);
    510 	else
    511 		dsmp = lookup_smach(ifname, isv6);
    512 
    513 	if (dsmp != NULL) {
    514 		/* Note that verify_smach drops a reference */
    515 		hold_smach(dsmp);
    516 		if (!verify_smach(dsmp))
    517 			dsmp = NULL;
    518 	}
    519 
    520 	if (dsmp == NULL) {
    521 		/*
    522 		 * If the user asked for the primary DHCP interface by giving
    523 		 * an empty string and there is no primary, then check if we're
    524 		 * handling dhcpinfo.  If so, then simulate primary selection.
    525 		 * Otherwise, report failure.
    526 		 */
    527 		if (ifname[0] == '\0') {
    528 			if (ia.ia_cmd == DHCP_GET_TAG)
    529 				dsmp = info_primary_smach(isv6);
    530 			if (dsmp == NULL)
    531 				error = DHCP_IPC_E_NOPRIMARY;
    532 
    533 		/*
    534 		 * If there's no interface, and we're starting up, then create
    535 		 * it now, along with a state machine for it.  Note that if
    536 		 * insert_smach fails, it discards the LIF reference.
    537 		 */
    538 		} else if (ipc_cmd_flags[ia.ia_cmd] & CMD_CREATE) {
    539 			dhcp_lif_t *lif;
    540 
    541 			lif = attach_lif(ifname, isv6, &error);
    542 			if (lif != NULL &&
    543 			    (dsmp = insert_smach(lif, &error)) != NULL) {
    544 				/*
    545 				 * Get client ID for logical interface.  (V4
    546 				 * only, because V6 plumbs its own interfaces.)
    547 				 */
    548 				error = get_smach_cid(dsmp);
    549 				if (error != DHCP_IPC_SUCCESS) {
    550 					remove_smach(dsmp);
    551 					dsmp = NULL;
    552 				}
    553 				dsm_created = (dsmp != NULL);
    554 			}
    555 
    556 		/*
    557 		 * Otherwise, this is an operation on an unknown interface.
    558 		 */
    559 		} else {
    560 			error = DHCP_IPC_E_UNKIF;
    561 		}
    562 		if (dsmp == NULL) {
    563 			send_error_reply(&ia, error);
    564 			return;
    565 		}
    566 	}
    567 
    568 	/*
    569 	 * If this is a request for DHCP to manage a lease on an address,
    570 	 * ensure that IFF_DHCPRUNNING is set (we don't set this when the lif
    571 	 * is created because the lif may have been created for INFORM).
    572 	 */
    573 	if (ia.ia_cmd == DHCP_START &&
    574 	    (error = set_lif_dhcp(dsmp->dsm_lif)) != DHCP_IPC_SUCCESS) {
    575 		if (dsm_created)
    576 			remove_smach(dsmp);
    577 		send_error_reply(&ia, error);
    578 		return;
    579 	}
    580 
    581 	if ((dsmp->dsm_dflags & DHCP_IF_BOOTP) &&
    582 	    !(ipc_cmd_flags[ia.ia_cmd] & CMD_BOOTP)) {
    583 		dhcpmsg(MSG_ERROR, "command %s not valid for BOOTP on %s",
    584 		    dhcp_ipc_type_to_string(ia.ia_cmd), dsmp->dsm_name);
    585 		send_error_reply(&ia, DHCP_IPC_E_BOOTP);
    586 		return;
    587 	}
    588 
    589 	/*
    590 	 * verify that the state machine is in a state which will allow the
    591 	 * command.  we do this up front so that we can return an error
    592 	 * *before* needlessly cancelling an in-progress transaction.
    593 	 */
    594 
    595 	if (!check_cmd_allowed(dsmp->dsm_state, ia.ia_cmd)) {
    596 		dhcpmsg(MSG_DEBUG,
    597 		    "in state %s; not allowing %s command on %s",
    598 		    dhcp_state_to_string(dsmp->dsm_state),
    599 		    dhcp_ipc_type_to_string(ia.ia_cmd), dsmp->dsm_name);
    600 		send_error_reply(&ia,
    601 		    ia.ia_cmd == DHCP_START && dsmp->dsm_state != INIT ?
    602 		    DHCP_IPC_E_RUNNING : DHCP_IPC_E_OUTSTATE);
    603 		return;
    604 	}
    605 
    606 	dhcpmsg(MSG_DEBUG, "in state %s; allowing %s command on %s",
    607 	    dhcp_state_to_string(dsmp->dsm_state),
    608 	    dhcp_ipc_type_to_string(ia.ia_cmd), dsmp->dsm_name);
    609 
    610 	if ((ia.ia_request->message_type & DHCP_PRIMARY) && is_priv)
    611 		make_primary(dsmp);
    612 
    613 	/*
    614 	 * The current design dictates that there can be only one outstanding
    615 	 * transaction per state machine -- this simplifies the code
    616 	 * considerably and also fits well with RFCs 2131 and 3315.  It is
    617 	 * worth classifying the different DHCP commands into synchronous
    618 	 * (those which we will handle now and reply to immediately) and
    619 	 * asynchronous (those which require transactions and will be completed
    620 	 * at an indeterminate time in the future):
    621 	 *
    622 	 *    DROP: removes the agent's management of a state machine.
    623 	 *	    asynchronous as the script program may be invoked.
    624 	 *
    625 	 *    PING: checks to see if the agent has a named state machine.
    626 	 *	    synchronous, since no packets need to be sent
    627 	 *	    to the DHCP server.
    628 	 *
    629 	 *  STATUS: returns information about a state machine.
    630 	 *	    synchronous, since no packets need to be sent
    631 	 *	    to the DHCP server.
    632 	 *
    633 	 * RELEASE: releases the agent's management of a state machine
    634 	 *	    and brings the associated interfaces down.  asynchronous
    635 	 *	    as the script program may be invoked.
    636 	 *
    637 	 *  EXTEND: renews a lease.  asynchronous, since the agent
    638 	 *	    needs to wait for an ACK, etc.
    639 	 *
    640 	 *   START: starts DHCP on a named state machine.  asynchronous since
    641 	 *	    the agent needs to wait for OFFERs, ACKs, etc.
    642 	 *
    643 	 *  INFORM: obtains configuration parameters for the system using
    644 	 *	    externally configured interface.  asynchronous, since the
    645 	 *	    agent needs to wait for an ACK.
    646 	 *
    647 	 * Notice that EXTEND, INFORM, START, DROP and RELEASE are
    648 	 * asynchronous.  Notice also that asynchronous commands may occur from
    649 	 * within the agent -- for instance, the agent will need to do implicit
    650 	 * EXTENDs to extend the lease. In order to make the code simpler, the
    651 	 * following rules apply for asynchronous commands:
    652 	 *
    653 	 * There can only be one asynchronous command at a time per state
    654 	 * machine.  The current asynchronous command is managed by the async_*
    655 	 * api: async_start(), async_finish(), and async_cancel().
    656 	 * async_start() starts management of a new asynchronous command on an
    657 	 * state machine, which should only be done after async_cancel() to
    658 	 * terminate a previous command.  When the command is completed,
    659 	 * async_finish() should be called.
    660 	 *
    661 	 * Asynchronous commands started by a user command have an associated
    662 	 * ipc_action which provides the agent with information for how to get
    663 	 * in touch with the user command when the action completes.  These
    664 	 * ipc_action records also have an associated timeout which may be
    665 	 * infinite.  ipc_action_start() should be called when starting an
    666 	 * asynchronous command requested by a user, which sets up the timer
    667 	 * and keeps track of the ipc information (file descriptor, request
    668 	 * type).  When the asynchronous command completes, ipc_action_finish()
    669 	 * should be called to return a command status code to the user and
    670 	 * close the ipc connection).  If the command does not complete before
    671 	 * the timer fires, ipc_action_timeout() is called which closes the ipc
    672 	 * connection and returns DHCP_IPC_E_TIMEOUT to the user.  Note that
    673 	 * independent of ipc_action_timeout(), ipc_action_finish() should be
    674 	 * called.
    675 	 *
    676 	 * on a case-by-case basis, here is what happens (per state machine):
    677 	 *
    678 	 *    o When an asynchronous command is requested, then
    679 	 *	async_cancel() is called to terminate any non-user
    680 	 *	action in progress.  If there's a user action running,
    681 	 *	the user command is sent DHCP_IPC_E_PEND.
    682 	 *
    683 	 *    o otherwise, the the transaction is started with
    684 	 *	async_start().  if the transaction is on behalf
    685 	 *	of a user, ipc_action_start() is called to keep
    686 	 *	track of the ipc information and set up the
    687 	 *	ipc_action timer.
    688 	 *
    689 	 *    o if the command completes normally and before a
    690 	 *	timeout fires, then async_finish() is called.
    691 	 *	if there was an associated ipc_action,
    692 	 *	ipc_action_finish() is called to complete it.
    693 	 *
    694 	 *    o if the command fails before a timeout fires, then
    695 	 *	async_finish() is called, and the state machine is
    696 	 *	is returned to a known state based on the command.
    697 	 *	if there was an associated ipc_action,
    698 	 *	ipc_action_finish() is called to complete it.
    699 	 *
    700 	 *    o if the ipc_action timer fires before command
    701 	 *	completion, then DHCP_IPC_E_TIMEOUT is returned to
    702 	 *	the user.  however, the transaction continues to
    703 	 *	be carried out asynchronously.
    704 	 */
    705 
    706 	if (ipc_cmd_flags[ia.ia_cmd] & CMD_IMMED) {
    707 		/*
    708 		 * Only immediate commands (ping, status, get_tag) need to
    709 		 * worry about freeing ia through one of the reply functions
    710 		 * before returning.
    711 		 */
    712 		iap = &ia;
    713 	} else {
    714 		/*
    715 		 * if shutdown request has been received, send back an error.
    716 		 */
    717 		if (shutdown_started) {
    718 			send_error_reply(&ia, DHCP_IPC_E_OUTSTATE);
    719 			return;
    720 		}
    721 
    722 		if (dsmp->dsm_dflags & DHCP_IF_BUSY) {
    723 			send_error_reply(&ia, DHCP_IPC_E_PEND);
    724 			return;
    725 		}
    726 
    727 		if (!ipc_action_start(dsmp, &ia)) {
    728 			dhcpmsg(MSG_WARNING, "ipc_event: ipc_action_start "
    729 			    "failed for %s", dsmp->dsm_name);
    730 			send_error_reply(&ia, DHCP_IPC_E_MEMORY);
    731 			return;
    732 		}
    733 
    734 		/* Action structure consumed by above function */
    735 		iap = &dsmp->dsm_ia;
    736 	}
    737 
    738 	switch (iap->ia_cmd) {
    739 
    740 	case DHCP_DROP:
    741 		if (dsmp->dsm_droprelease)
    742 			break;
    743 		dsmp->dsm_droprelease = B_TRUE;
    744 
    745 		/*
    746 		 * Ensure that a timer associated with the existing state
    747 		 * doesn't pop while we're waiting for the script to complete.
    748 		 * (If so, chaos can result -- e.g., a timer causes us to end
    749 		 * up in dhcp_selecting() would start acquiring a new lease on
    750 		 * dsmp while our DHCP_DROP dismantling is ongoing.)
    751 		 */
    752 		cancel_smach_timers(dsmp);
    753 		(void) script_start(dsmp, isv6 ? EVENT_DROP6 : EVENT_DROP,
    754 		    dhcp_drop, NULL, NULL);
    755 		break;		/* not an immediate function */
    756 
    757 	case DHCP_EXTEND:
    758 		(void) dhcp_extending(dsmp);
    759 		break;
    760 
    761 	case DHCP_GET_TAG: {
    762 		dhcp_optnum_t	optnum;
    763 		void		*opt = NULL;
    764 		uint_t		optlen;
    765 		boolean_t	did_alloc = B_FALSE;
    766 		PKT_LIST	*ack = dsmp->dsm_ack;
    767 		int		i;
    768 
    769 		/*
    770 		 * verify the request makes sense.
    771 		 */
    772 
    773 		if (iap->ia_request->data_type   != DHCP_TYPE_OPTNUM ||
    774 		    iap->ia_request->data_length != sizeof (dhcp_optnum_t)) {
    775 			send_error_reply(iap, DHCP_IPC_E_PROTO);
    776 			break;
    777 		}
    778 
    779 		(void) memcpy(&optnum, iap->ia_request->buffer,
    780 		    sizeof (dhcp_optnum_t));
    781 
    782 load_option:
    783 		switch (optnum.category) {
    784 
    785 		case DSYM_SITE:			/* FALLTHRU */
    786 		case DSYM_STANDARD:
    787 			for (i = 0; i < dsmp->dsm_pillen; i++) {
    788 				if (dsmp->dsm_pil[i] == optnum.code)
    789 					break;
    790 			}
    791 			if (i < dsmp->dsm_pillen)
    792 				break;
    793 			if (isv6) {
    794 				opt = dhcpv6_pkt_option(ack, NULL, optnum.code,
    795 				    NULL);
    796 			} else {
    797 				if (optnum.code <= DHCP_LAST_OPT)
    798 					opt = ack->opts[optnum.code];
    799 			}
    800 			break;
    801 
    802 		case DSYM_VENDOR:
    803 			if (isv6) {
    804 				dhcpv6_option_t *d6o;
    805 				uint32_t ent;
    806 
    807 				/*
    808 				 * Look through vendor options to find our
    809 				 * enterprise number.
    810 				 */
    811 				d6o = NULL;
    812 				for (;;) {
    813 					d6o = dhcpv6_pkt_option(ack, d6o,
    814 					    DHCPV6_OPT_VENDOR_OPT, &optlen);
    815 					if (d6o == NULL)
    816 						break;
    817 					optlen -= sizeof (*d6o);
    818 					if (optlen < sizeof (ent))
    819 						continue;
    820 					(void) memcpy(&ent, d6o + 1,
    821 					    sizeof (ent));
    822 					if (ntohl(ent) != DHCPV6_SUN_ENT)
    823 						continue;
    824 					break;
    825 				}
    826 				if (d6o != NULL) {
    827 					/*
    828 					 * Now find the requested vendor option
    829 					 * within the vendor options block.
    830 					 */
    831 					opt = dhcpv6_find_option(
    832 					    (char *)(d6o + 1) + sizeof (ent),
    833 					    optlen - sizeof (ent), NULL,
    834 					    optnum.code, NULL);
    835 				}
    836 			} else {
    837 				/*
    838 				 * the test against VS_OPTION_START is broken
    839 				 * up into two tests to avoid compiler warnings
    840 				 * under intel.
    841 				 */
    842 				if ((optnum.code > VS_OPTION_START ||
    843 				    optnum.code == VS_OPTION_START) &&
    844 				    optnum.code <= VS_OPTION_END)
    845 					opt = ack->vs[optnum.code];
    846 			}
    847 			break;
    848 
    849 		case DSYM_FIELD:
    850 			if (isv6) {
    851 				dhcpv6_message_t *d6m =
    852 				    (dhcpv6_message_t *)ack->pkt;
    853 				dhcpv6_option_t *d6o;
    854 
    855 				/* Validate the packet field the user wants */
    856 				optlen = optnum.code + optnum.size;
    857 				if (d6m->d6m_msg_type ==
    858 				    DHCPV6_MSG_RELAY_FORW ||
    859 				    d6m->d6m_msg_type ==
    860 				    DHCPV6_MSG_RELAY_REPL) {
    861 					if (optlen > sizeof (dhcpv6_relay_t))
    862 						break;
    863 				} else {
    864 					if (optlen > sizeof (*d6m))
    865 						break;
    866 				}
    867 
    868 				opt = malloc(sizeof (*d6o) + optnum.size);
    869 				if (opt != NULL) {
    870 					d6o = opt;
    871 					d6o->d6o_code = htons(optnum.code);
    872 					d6o->d6o_len = htons(optnum.size);
    873 					(void) memcpy(d6o + 1, (caddr_t)d6m +
    874 					    optnum.code, optnum.size);
    875 				}
    876 			} else {
    877 				if (optnum.code + optnum.size > sizeof (PKT))
    878 					break;
    879 
    880 				/*
    881 				 * + 2 to account for option code and length
    882 				 * byte
    883 				 */
    884 				opt = malloc(optnum.size + 2);
    885 				if (opt != NULL) {
    886 					DHCP_OPT *v4opt = opt;
    887 
    888 					v4opt->len  = optnum.size;
    889 					v4opt->code = optnum.code;
    890 					(void) memcpy(v4opt->value,
    891 					    (caddr_t)ack->pkt + optnum.code,
    892 					    optnum.size);
    893 				}
    894 			}
    895 
    896 			if (opt == NULL) {
    897 				send_error_reply(iap, DHCP_IPC_E_MEMORY);
    898 				return;
    899 			}
    900 			did_alloc = B_TRUE;
    901 			break;
    902 
    903 		default:
    904 			send_error_reply(iap, DHCP_IPC_E_PROTO);
    905 			return;
    906 		}
    907 
    908 		/*
    909 		 * return the option payload, if there was one.  the "+ 2"
    910 		 * accounts for the option code number and length byte.
    911 		 */
    912 
    913 		if (opt != NULL) {
    914 			if (isv6) {
    915 				dhcpv6_option_t d6ov;
    916 
    917 				(void) memcpy(&d6ov, opt, sizeof (d6ov));
    918 				optlen = ntohs(d6ov.d6o_len) + sizeof (d6ov);
    919 			} else {
    920 				optlen = ((DHCP_OPT *)opt)->len + 2;
    921 			}
    922 			send_data_reply(iap, 0, DHCP_TYPE_OPTION, opt, optlen);
    923 
    924 			if (did_alloc)
    925 				free(opt);
    926 			break;
    927 		} else if (ack != dsmp->dsm_orig_ack) {
    928 			/*
    929 			 * There wasn't any definition for the option in the
    930 			 * current ack, so now retry with the original ack if
    931 			 * the original ack is not the current ack.
    932 			 */
    933 			ack = dsmp->dsm_orig_ack;
    934 			goto load_option;
    935 		}
    936 
    937 		/*
    938 		 * note that an "okay" response is returned either in
    939 		 * the case of an unknown option or a known option
    940 		 * with no payload.  this is okay (for now) since
    941 		 * dhcpinfo checks whether an option is valid before
    942 		 * ever performing ipc with the agent.
    943 		 */
    944 
    945 		send_ok_reply(iap);
    946 		break;
    947 	}
    948 
    949 	case DHCP_INFORM:
    950 		dhcp_inform(dsmp);
    951 		/* next destination: dhcp_acknak() */
    952 		break;		/* not an immediate function */
    953 
    954 	case DHCP_PING:
    955 		if (dsmp->dsm_dflags & DHCP_IF_FAILED)
    956 			send_error_reply(iap, DHCP_IPC_E_FAILEDIF);
    957 		else
    958 			send_ok_reply(iap);
    959 		break;
    960 
    961 	case DHCP_RELEASE:
    962 		if (dsmp->dsm_droprelease)
    963 			break;
    964 		dsmp->dsm_droprelease = B_TRUE;
    965 		cancel_smach_timers(dsmp); /* see comment in DHCP_DROP above */
    966 		(void) script_start(dsmp, isv6 ? EVENT_RELEASE6 :
    967 		    EVENT_RELEASE, dhcp_release, "Finished with lease.", NULL);
    968 		break;		/* not an immediate function */
    969 
    970 	case DHCP_START: {
    971 		PKT_LIST *ack, *oack;
    972 		PKT_LIST *plp[2];
    973 
    974 		deprecate_leases(dsmp);
    975 
    976 		/*
    977 		 * if we have a valid hostconf lying around, then jump
    978 		 * into INIT_REBOOT.  if it fails, we'll end up going
    979 		 * through the whole selecting() procedure again.
    980 		 */
    981 
    982 		error = read_hostconf(dsmp->dsm_name, plp, 2, dsmp->dsm_isv6);
    983 		ack = error > 0 ? plp[0] : NULL;
    984 		oack = error > 1 ? plp[1] : NULL;
    985 
    986 		/*
    987 		 * If the allocation of the old ack fails, that's fine;
    988 		 * continue without it.
    989 		 */
    990 		if (oack == NULL)
    991 			oack = ack;
    992 
    993 		/*
    994 		 * As long as we've allocated something, start using it.
    995 		 */
    996 		if (ack != NULL) {
    997 			dsmp->dsm_orig_ack = oack;
    998 			dsmp->dsm_ack = ack;
    999 			dhcp_init_reboot(dsmp);
   1000 			/* next destination: dhcp_acknak() */
   1001 			break;
   1002 		}
   1003 
   1004 		/*
   1005 		 * if not debugging, wait for a few seconds before
   1006 		 * going into SELECTING.
   1007 		 */
   1008 
   1009 		if (debug_level == 0 && set_start_timer(dsmp)) {
   1010 			/* next destination: dhcp_start() */
   1011 			break;
   1012 		} else {
   1013 			dhcp_selecting(dsmp);
   1014 			/* next destination: dhcp_requesting() */
   1015 			break;
   1016 		}
   1017 	}
   1018 
   1019 	case DHCP_STATUS: {
   1020 		dhcp_status_t	status;
   1021 		dhcp_lease_t	*dlp;
   1022 
   1023 		status.if_began = monosec_to_time(dsmp->dsm_curstart_monosec);
   1024 
   1025 		/*
   1026 		 * We return information on just the first lease as being
   1027 		 * representative of the lot.  A better status mechanism is
   1028 		 * needed.
   1029 		 */
   1030 		dlp = dsmp->dsm_leases;
   1031 
   1032 		if (dlp == NULL ||
   1033 		    dlp->dl_lifs->lif_expire.dt_start == DHCP_PERM) {
   1034 			status.if_t1	= DHCP_PERM;
   1035 			status.if_t2	= DHCP_PERM;
   1036 			status.if_lease	= DHCP_PERM;
   1037 		} else {
   1038 			status.if_t1	= status.if_began +
   1039 			    dlp->dl_t1.dt_start;
   1040 			status.if_t2	= status.if_began +
   1041 			    dlp->dl_t2.dt_start;
   1042 			status.if_lease	= status.if_began +
   1043 			    dlp->dl_lifs->lif_expire.dt_start;
   1044 		}
   1045 
   1046 		status.version		= DHCP_STATUS_VER;
   1047 		status.if_state		= dsmp->dsm_state;
   1048 		status.if_dflags	= dsmp->dsm_dflags;
   1049 		status.if_sent		= dsmp->dsm_sent;
   1050 		status.if_recv		= dsmp->dsm_received;
   1051 		status.if_bad_offers	= dsmp->dsm_bad_offers;
   1052 
   1053 		(void) strlcpy(status.if_name, dsmp->dsm_name, LIFNAMSIZ);
   1054 
   1055 		send_data_reply(iap, 0, DHCP_TYPE_STATUS, &status,
   1056 		    sizeof (dhcp_status_t));
   1057 		break;
   1058 	}
   1059 	}
   1060 }
   1061 
   1062 /*
   1063  * check_rtm_addr(): determine if routing socket message matches interface
   1064  *		     address
   1065  *
   1066  *   input: const struct if_msghdr *: pointer to routing socket message
   1067  *	    int: routing socket message length
   1068  *	    boolean_t: set to B_TRUE if IPv6
   1069  *	    const in6_addr_t *: pointer to IP address
   1070  *  output: boolean_t: B_TRUE if address is a match
   1071  */
   1072 
   1073 static boolean_t
   1074 check_rtm_addr(const struct ifa_msghdr *ifam, int msglen, boolean_t isv6,
   1075     const in6_addr_t *addr)
   1076 {
   1077 	const char *cp, *lim;
   1078 	uint_t flag;
   1079 	const struct sockaddr *sa;
   1080 
   1081 	if (!(ifam->ifam_addrs & RTA_IFA))
   1082 		return (B_FALSE);
   1083 
   1084 	cp = (const char *)(ifam + 1);
   1085 	lim = (const char *)ifam + msglen;
   1086 	for (flag = 1; flag < RTA_IFA; flag <<= 1) {
   1087 		if (ifam->ifam_addrs & flag) {
   1088 			/* LINTED: alignment */
   1089 			sa = (const struct sockaddr *)cp;
   1090 			if ((const char *)(sa + 1) > lim)
   1091 				return (B_FALSE);
   1092 			switch (sa->sa_family) {
   1093 			case AF_INET:
   1094 				cp += sizeof (struct sockaddr_in);
   1095 				break;
   1096 			case AF_LINK:
   1097 				cp += sizeof (struct sockaddr_dl);
   1098 				break;
   1099 			case AF_INET6:
   1100 				cp += sizeof (struct sockaddr_in6);
   1101 				break;
   1102 			default:
   1103 				cp += sizeof (struct sockaddr);
   1104 				break;
   1105 			}
   1106 		}
   1107 	}
   1108 	if (isv6) {
   1109 		const struct sockaddr_in6 *sin6;
   1110 
   1111 		/* LINTED: alignment */
   1112 		sin6 = (const struct sockaddr_in6 *)cp;
   1113 		if ((const char *)(sin6 + 1) > lim)
   1114 			return (B_FALSE);
   1115 		if (sin6->sin6_family != AF_INET6)
   1116 			return (B_FALSE);
   1117 		return (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, addr));
   1118 	} else {
   1119 		const struct sockaddr_in *sinp;
   1120 		ipaddr_t v4addr;
   1121 
   1122 		/* LINTED: alignment */
   1123 		sinp = (const struct sockaddr_in *)cp;
   1124 		if ((const char *)(sinp + 1) > lim)
   1125 			return (B_FALSE);
   1126 		if (sinp->sin_family != AF_INET)
   1127 			return (B_FALSE);
   1128 		IN6_V4MAPPED_TO_IPADDR(addr, v4addr);
   1129 		return (sinp->sin_addr.s_addr == v4addr);
   1130 	}
   1131 }
   1132 
   1133 /*
   1134  * is_rtm_v6(): determine if routing socket message is IPv6
   1135  *
   1136  *   input: struct ifa_msghdr *: pointer to routing socket message
   1137  *	    int: message length
   1138  *  output: boolean_t
   1139  */
   1140 
   1141 static boolean_t
   1142 is_rtm_v6(const struct ifa_msghdr *ifam, int msglen)
   1143 {
   1144 	const char *cp, *lim;
   1145 	uint_t flag;
   1146 	const struct sockaddr *sa;
   1147 
   1148 	cp = (const char *)(ifam + 1);
   1149 	lim = (const char *)ifam + msglen;
   1150 	for (flag = ifam->ifam_addrs; flag != 0; flag &= flag - 1) {
   1151 		/* LINTED: alignment */
   1152 		sa = (const struct sockaddr *)cp;
   1153 		if ((const char *)(sa + 1) > lim)
   1154 			return (B_FALSE);
   1155 		switch (sa->sa_family) {
   1156 		case AF_INET:
   1157 			return (B_FALSE);
   1158 		case AF_LINK:
   1159 			cp += sizeof (struct sockaddr_dl);
   1160 			break;
   1161 		case AF_INET6:
   1162 			return (B_TRUE);
   1163 		default:
   1164 			cp += sizeof (struct sockaddr);
   1165 			break;
   1166 		}
   1167 	}
   1168 	return (B_FALSE);
   1169 }
   1170 
   1171 /*
   1172  * check_lif(): check the state of a given logical interface and its DHCP
   1173  *		lease.  We've been told by the routing socket that the
   1174  *		corresponding ifIndex has changed.  This may mean that DAD has
   1175  *		completed or failed.
   1176  *
   1177  *   input: dhcp_lif_t *: pointer to the LIF
   1178  *	    const struct ifa_msghdr *: routing socket message
   1179  *	    int: size of routing socket message
   1180  *  output: boolean_t: B_TRUE if DAD has completed on this interface
   1181  */
   1182 
   1183 static boolean_t
   1184 check_lif(dhcp_lif_t *lif, const struct ifa_msghdr *ifam, int msglen)
   1185 {
   1186 	boolean_t isv6, dad_wait, unplumb;
   1187 	int fd;
   1188 	struct lifreq lifr;
   1189 
   1190 	isv6 = lif->lif_pif->pif_isv6;
   1191 	fd = isv6 ? v6_sock_fd : v4_sock_fd;
   1192 
   1193 	/*
   1194 	 * Get the real (64 bit) logical interface flags.  Note that the
   1195 	 * routing socket message has flags, but these are just the lower 32
   1196 	 * bits.
   1197 	 */
   1198 	unplumb = B_FALSE;
   1199 	(void) memset(&lifr, 0, sizeof (lifr));
   1200 	(void) strlcpy(lifr.lifr_name, lif->lif_name, sizeof (lifr.lifr_name));
   1201 	if (ioctl(fd, SIOCGLIFFLAGS, &lifr) == -1) {
   1202 		/*
   1203 		 * Failing to retrieve flags means that the interface is gone.
   1204 		 * It hasn't failed to verify with DAD, but we still have to
   1205 		 * give up on it.
   1206 		 */
   1207 		lifr.lifr_flags = 0;
   1208 		if (errno == ENXIO) {
   1209 			lif->lif_plumbed = B_FALSE;
   1210 			dhcpmsg(MSG_INFO, "%s has been removed; abandoning",
   1211 			    lif->lif_name);
   1212 			if (!isv6)
   1213 				discard_default_routes(lif->lif_smachs);
   1214 		} else {
   1215 			dhcpmsg(MSG_ERR,
   1216 			    "unable to retrieve interface flags on %s",
   1217 			    lif->lif_name);
   1218 		}
   1219 		unplumb = B_TRUE;
   1220 	} else if (!check_rtm_addr(ifam, msglen, isv6, &lif->lif_v6addr)) {
   1221 		/*
   1222 		 * If the message is not about this logical interface,
   1223 		 * then just ignore it.
   1224 		 */
   1225 		return (B_FALSE);
   1226 	} else if (lifr.lifr_flags & IFF_DUPLICATE) {
   1227 		dhcpmsg(MSG_ERROR, "interface %s has duplicate address",
   1228 		    lif->lif_name);
   1229 		lif_mark_decline(lif, "duplicate address");
   1230 		close_ip_lif(lif);
   1231 		(void) open_ip_lif(lif, INADDR_ANY, B_TRUE);
   1232 	}
   1233 
   1234 	dad_wait = lif->lif_dad_wait;
   1235 	if (dad_wait) {
   1236 		dhcpmsg(MSG_VERBOSE, "check_lif: %s has finished DAD",
   1237 		    lif->lif_name);
   1238 		lif->lif_dad_wait = B_FALSE;
   1239 	}
   1240 
   1241 	if (unplumb)
   1242 		unplumb_lif(lif);
   1243 
   1244 	return (dad_wait);
   1245 }
   1246 
   1247 /*
   1248  * check_main_lif(): check the state of a main logical interface for a state
   1249  *		     machine.  This is used only for DHCPv6.
   1250  *
   1251  *   input: dhcp_smach_t *: pointer to the state machine
   1252  *	    const struct ifa_msghdr *: routing socket message
   1253  *	    int: size of routing socket message
   1254  *  output: boolean_t: B_TRUE if LIF is ok.
   1255  */
   1256 
   1257 static boolean_t
   1258 check_main_lif(dhcp_smach_t *dsmp, const struct ifa_msghdr *ifam, int msglen)
   1259 {
   1260 	dhcp_lif_t *lif = dsmp->dsm_lif;
   1261 	struct lifreq lifr;
   1262 
   1263 	/*
   1264 	 * Get the real (64 bit) logical interface flags.  Note that the
   1265 	 * routing socket message has flags, but these are just the lower 32
   1266 	 * bits.
   1267 	 */
   1268 	(void) memset(&lifr, 0, sizeof (lifr));
   1269 	(void) strlcpy(lifr.lifr_name, lif->lif_name, sizeof (lifr.lifr_name));
   1270 	if (ioctl(v6_sock_fd, SIOCGLIFFLAGS, &lifr) == -1) {
   1271 		/*
   1272 		 * Failing to retrieve flags means that the interface is gone.
   1273 		 * Our state machine is now trash.
   1274 		 */
   1275 		if (errno == ENXIO) {
   1276 			dhcpmsg(MSG_INFO, "%s has been removed; abandoning",
   1277 			    lif->lif_name);
   1278 		} else {
   1279 			dhcpmsg(MSG_ERR,
   1280 			    "unable to retrieve interface flags on %s",
   1281 			    lif->lif_name);
   1282 		}
   1283 		return (B_FALSE);
   1284 	} else if (!check_rtm_addr(ifam, msglen, B_TRUE, &lif->lif_v6addr)) {
   1285 		/*
   1286 		 * If the message is not about this logical interface,
   1287 		 * then just ignore it.
   1288 		 */
   1289 		return (B_TRUE);
   1290 	} else if (lifr.lifr_flags & IFF_DUPLICATE) {
   1291 		dhcpmsg(MSG_ERROR, "interface %s has duplicate address",
   1292 		    lif->lif_name);
   1293 		return (B_FALSE);
   1294 	} else {
   1295 		return (B_TRUE);
   1296 	}
   1297 }
   1298 
   1299 /*
   1300  * process_link_up_down(): check the state of a physical interface for up/down
   1301  *			   transitions; must go through INIT_REBOOT state if
   1302  *			   the link flaps.
   1303  *
   1304  *   input: dhcp_pif_t *: pointer to the physical interface to check
   1305  *	    const struct if_msghdr *: routing socket message
   1306  *  output: none
   1307  */
   1308 
   1309 static void
   1310 process_link_up_down(dhcp_pif_t *pif, const struct if_msghdr *ifm)
   1311 {
   1312 	struct lifreq lifr;
   1313 	boolean_t isv6;
   1314 	int fd;
   1315 
   1316 	/*
   1317 	 * If the message implies no change of flags, then we're done; no need
   1318 	 * to check further.  Note that if we have multiple state machines on a
   1319 	 * single physical interface, this test keeps us from issuing an ioctl
   1320 	 * for each one.
   1321 	 */
   1322 	if ((ifm->ifm_flags & IFF_RUNNING) && pif->pif_running ||
   1323 	    !(ifm->ifm_flags & IFF_RUNNING) && !pif->pif_running)
   1324 		return;
   1325 
   1326 	/*
   1327 	 * We don't know what the real interface flags are, because the
   1328 	 * if_index number is only 16 bits; we must go ask.
   1329 	 */
   1330 	isv6 = pif->pif_isv6;
   1331 	fd = isv6 ? v6_sock_fd : v4_sock_fd;
   1332 	(void) memset(&lifr, 0, sizeof (lifr));
   1333 	(void) strlcpy(lifr.lifr_name, pif->pif_name, sizeof (lifr.lifr_name));
   1334 
   1335 	if (ioctl(fd, SIOCGLIFFLAGS, &lifr) == -1 ||
   1336 	    !(lifr.lifr_flags & IFF_RUNNING)) {
   1337 		/*
   1338 		 * If we've lost the interface or it has gone down, then
   1339 		 * nothing special to do; just turn off the running flag.
   1340 		 */
   1341 		pif_status(pif, B_FALSE);
   1342 	} else {
   1343 		/*
   1344 		 * Interface has come back up: go through verification process.
   1345 		 */
   1346 		pif_status(pif, B_TRUE);
   1347 	}
   1348 }
   1349 
   1350 /*
   1351  * rtsock_event(): fetches routing socket messages and updates internal
   1352  *		   interface state based on those messages.
   1353  *
   1354  *   input: iu_eh_t *: unused
   1355  *	    int: the routing socket file descriptor
   1356  *	    (other arguments unused)
   1357  *  output: void
   1358  */
   1359 
   1360 /* ARGSUSED */
   1361 static void
   1362 rtsock_event(iu_eh_t *ehp, int fd, short events, iu_event_id_t id, void *arg)
   1363 {
   1364 	dhcp_smach_t *dsmp, *dsmnext;
   1365 	union {
   1366 		struct ifa_msghdr ifam;
   1367 		struct if_msghdr ifm;
   1368 		char buf[1024];
   1369 	} msg;
   1370 	uint16_t ifindex;
   1371 	int msglen;
   1372 	boolean_t isv6;
   1373 
   1374 	if ((msglen = read(fd, &msg, sizeof (msg))) <= 0)
   1375 		return;
   1376 
   1377 	/* Note that the routing socket interface index is just 16 bits */
   1378 	if (msg.ifm.ifm_type == RTM_IFINFO) {
   1379 		ifindex = msg.ifm.ifm_index;
   1380 		isv6 = (msg.ifm.ifm_flags & IFF_IPV6) ? B_TRUE : B_FALSE;
   1381 	} else if (msg.ifam.ifam_type == RTM_DELADDR ||
   1382 	    msg.ifam.ifam_type == RTM_NEWADDR) {
   1383 		ifindex = msg.ifam.ifam_index;
   1384 		isv6 = is_rtm_v6(&msg.ifam, msglen);
   1385 	} else {
   1386 		return;
   1387 	}
   1388 
   1389 	for (dsmp = lookup_smach_by_uindex(ifindex, NULL, isv6);
   1390 	    dsmp != NULL; dsmp = dsmnext) {
   1391 		DHCPSTATE oldstate;
   1392 		boolean_t lif_finished;
   1393 		boolean_t lease_removed;
   1394 		dhcp_lease_t *dlp, *dlnext;
   1395 
   1396 		/*
   1397 		 * Note that script_start can call dhcp_drop directly, and
   1398 		 * that will do release_smach.
   1399 		 */
   1400 		dsmnext = lookup_smach_by_uindex(ifindex, dsmp, isv6);
   1401 		oldstate = dsmp->dsm_state;
   1402 
   1403 		/*
   1404 		 * Ignore state machines that are currently processing drop or
   1405 		 * release; there is nothing more we can do for them.
   1406 		 */
   1407 		if (dsmp->dsm_droprelease)
   1408 			continue;
   1409 
   1410 		/*
   1411 		 * Look for link up/down notifications.  These occur on a
   1412 		 * physical interface basis.
   1413 		 */
   1414 		if (msg.ifm.ifm_type == RTM_IFINFO) {
   1415 			process_link_up_down(dsmp->dsm_lif->lif_pif, &msg.ifm);
   1416 			continue;
   1417 		}
   1418 
   1419 		/*
   1420 		 * Since we cannot trust the flags reported by the routing
   1421 		 * socket (they're just 32 bits -- and thus never include
   1422 		 * IFF_DUPLICATE), and we can't trust the ifindex (it's only 16
   1423 		 * bits and also doesn't reflect the alias in use), we get
   1424 		 * flags on all matching interfaces, and go by that.
   1425 		 */
   1426 		lif_finished = B_FALSE;
   1427 		lease_removed = B_FALSE;
   1428 		for (dlp = dsmp->dsm_leases; dlp != NULL; dlp = dlnext) {
   1429 			dhcp_lif_t *lif, *lifnext;
   1430 			uint_t nlifs = dlp->dl_nlifs;
   1431 
   1432 			dlnext = dlp->dl_next;
   1433 			for (lif = dlp->dl_lifs; lif != NULL && nlifs > 0;
   1434 			    lif = lifnext, nlifs--) {
   1435 				lifnext = lif->lif_next;
   1436 				if (check_lif(lif, &msg.ifam, msglen)) {
   1437 					dsmp->dsm_lif_wait--;
   1438 					lif_finished = B_TRUE;
   1439 				}
   1440 			}
   1441 			if (dlp->dl_nlifs == 0) {
   1442 				remove_lease(dlp);
   1443 				lease_removed = B_TRUE;
   1444 			}
   1445 		}
   1446 
   1447 		if ((isv6 && !check_main_lif(dsmp, &msg.ifam, msglen)) ||
   1448 		    (!isv6 && !verify_lif(dsmp->dsm_lif))) {
   1449 			dsmp->dsm_droprelease = B_TRUE;
   1450 			(void) script_start(dsmp, isv6 ? EVENT_DROP6 :
   1451 			    EVENT_DROP, dhcp_drop, NULL, NULL);
   1452 			continue;
   1453 		}
   1454 
   1455 		/*
   1456 		 * Ignore this state machine if nothing interesting has
   1457 		 * happened.
   1458 		 */
   1459 		if (!lif_finished && dsmp->dsm_lif_down == 0 &&
   1460 		    (dsmp->dsm_leases != NULL || !lease_removed))
   1461 			continue;
   1462 
   1463 		/*
   1464 		 * If we're still waiting for DAD to complete on some of the
   1465 		 * configured LIFs, then don't send a response.
   1466 		 */
   1467 		if (dsmp->dsm_lif_wait != 0) {
   1468 			dhcpmsg(MSG_VERBOSE, "rtsock_event: %s still has %d "
   1469 			    "LIFs waiting on DAD", dsmp->dsm_name,
   1470 			    dsmp->dsm_lif_wait);
   1471 			continue;
   1472 		}
   1473 
   1474 		/*
   1475 		 * If we have some failed LIFs, then handle them now.  We'll
   1476 		 * remove them from the list.  Any leases that become empty are
   1477 		 * also removed as part of the decline-generation process.
   1478 		 */
   1479 		if (dsmp->dsm_lif_down != 0)
   1480 			send_declines(dsmp);
   1481 
   1482 		if (dsmp->dsm_leases == NULL) {
   1483 			dsmp->dsm_bad_offers++;
   1484 			/*
   1485 			 * For DHCPv6, we'll process the restart once we're
   1486 			 * done sending Decline messages, because these are
   1487 			 * supposed to be acknowledged.  With DHCPv4, there's
   1488 			 * no acknowledgment for a DECLINE, so after sending
   1489 			 * it, we just restart right away.
   1490 			 */
   1491 			if (!dsmp->dsm_isv6) {
   1492 				dhcpmsg(MSG_VERBOSE, "rtsock_event: %s has no "
   1493 				    "LIFs left", dsmp->dsm_name);
   1494 				dhcp_restart(dsmp);
   1495 			}
   1496 		} else {
   1497 			/*
   1498 			 * If we're now up on at least some of the leases and
   1499 			 * we were waiting for that, then kick off the rest of
   1500 			 * configuration.  Lease validation and DAD are done.
   1501 			 */
   1502 			dhcpmsg(MSG_VERBOSE, "rtsock_event: all LIFs verified "
   1503 			    "on %s in %s state", dsmp->dsm_name,
   1504 			    dhcp_state_to_string(oldstate));
   1505 			if (oldstate == PRE_BOUND ||
   1506 			    oldstate == ADOPTING)
   1507 				dhcp_bound_complete(dsmp);
   1508 			if (oldstate == ADOPTING)
   1509 				dhcp_adopt_complete(dsmp);
   1510 		}
   1511 	}
   1512 }
   1513 
   1514 /*
   1515  * check_cmd_allowed(): check whether the requested command is allowed in the
   1516  *			state specified.
   1517  *
   1518  *   input: DHCPSTATE: current state
   1519  *	    dhcp_ipc_type_t: requested command
   1520  *  output: boolean_t: B_TRUE if command is allowed in this state
   1521  */
   1522 
   1523 boolean_t
   1524 check_cmd_allowed(DHCPSTATE state, dhcp_ipc_type_t cmd)
   1525 {
   1526 	return (ipc_cmd_allowed[state][cmd] != 0);
   1527 }
   1528 
   1529 static boolean_t
   1530 is_iscsi_active(void)
   1531 {
   1532 	int fd;
   1533 	int active = 0;
   1534 
   1535 	if ((fd = open(ISCSI_DRIVER_DEVCTL, O_RDONLY)) != -1) {
   1536 		if (ioctl(fd, ISCSI_IS_ACTIVE, &active) != 0)
   1537 			active = 0;
   1538 		(void) close(fd);
   1539 	}
   1540 
   1541 	return (active != 0);
   1542 }
   1543