xref: /titanic_44/usr/src/cmd/cmd-inet/sbin/dhcpagent/agent.c (revision 3c112a2b34403220c06c3e2fcac403358cfba168)
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