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 (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
  23  */
  24 
  25 #include <sys/types.h>
  26 #include <stdlib.h>
  27 #include <assert.h>
  28 #include <errno.h>
  29 #include <locale.h>
  30 #include <string.h>
  31 #include <unistd.h>
  32 #include <signal.h>
  33 #include <stdio.h>
  34 #include <stdio_ext.h>
  35 #include <dhcp_hostconf.h>
  36 #include <dhcpagent_ipc.h>
  37 #include <dhcpagent_util.h>
  38 #include <dhcpmsg.h>
  39 #include <netinet/dhcp.h>
  40 #include <net/route.h>
  41 #include <sys/sockio.h>
  42 #include <sys/stat.h>
  43 #include <stropts.h>
  44 #include <fcntl.h>
  45 #include <sys/scsi/adapters/iscsi_if.h>
  46 
  47 #include "async.h"
  48 #include "agent.h"
  49 #include "script_handler.h"
  50 #include "util.h"
  51 #include "class_id.h"
  52 #include "states.h"
  53 #include "packet.h"
  54 #include "interface.h"
  55 #include "defaults.h"
  56 
  57 #ifndef TEXT_DOMAIN
  58 #define TEXT_DOMAIN     "SYS_TEST"
  59 #endif
  60 
  61 iu_timer_id_t           inactivity_id;
  62 int                     class_id_len = 0;
  63 char                    *class_id;
  64 iu_eh_t                 *eh;
  65 iu_tq_t                 *tq;
  66 pid_t                   grandparent;
  67 int                     rtsock_fd;
  68 
  69 static boolean_t        shutdown_started = B_FALSE;
  70 static boolean_t        do_adopt = B_FALSE;
  71 static unsigned int     debug_level = 0;
  72 static iu_eh_callback_t accept_event, ipc_event, rtsock_event;
  73 
  74 /*
  75  * The ipc_cmd_allowed[] table indicates which IPC commands are allowed in
  76  * which states; a non-zero value indicates the command is permitted.
  77  *
  78  * START is permitted if the state machine is fresh, or if we are in the
  79  * process of trying to obtain a lease (as a convenience to save the
  80  * administrator from having to do an explicit DROP).  EXTEND, RELEASE, and
  81  * GET_TAG require a lease to be obtained in order to make sense.  INFORM is
  82  * permitted if the interface is fresh or has an INFORM in progress or
  83  * previously done on it -- otherwise a DROP or RELEASE is first required.
  84  * PING and STATUS always make sense and thus are always permitted, as is DROP
  85  * in order to permit the administrator to always bail out.
  86  */
  87 static int ipc_cmd_allowed[DHCP_NSTATES][DHCP_NIPC] = {
  88         /*                        D  E  P  R  S  S  I  G */
  89         /*                        R  X  I  E  T  T  N  E */
  90         /*                        O  T  N  L  A  A  F  T */
  91         /*                        P  E  G  E  R  T  O  _ */
  92         /*                        .  N  .  A  T  U  R  T */
  93         /*                        .  D  .  S  .  S  M  A */
  94         /*                        .  .  .  E  .  .  .  G */
  95         /* INIT         */      { 1, 0, 1, 0, 1, 1, 1, 0 },
  96         /* SELECTING    */      { 1, 0, 1, 0, 1, 1, 0, 0 },
  97         /* REQUESTING   */      { 1, 0, 1, 0, 1, 1, 0, 0 },
  98         /* PRE_BOUND    */      { 1, 1, 1, 1, 0, 1, 0, 1 },
  99         /* BOUND        */      { 1, 1, 1, 1, 0, 1, 0, 1 },
 100         /* RENEWING     */      { 1, 1, 1, 1, 0, 1, 0, 1 },
 101         /* REBINDING    */      { 1, 1, 1, 1, 0, 1, 0, 1 },
 102         /* INFORMATION  */      { 1, 0, 1, 0, 1, 1, 1, 1 },
 103         /* INIT_REBOOT  */      { 1, 0, 1, 1, 1, 1, 0, 0 },
 104         /* ADOPTING     */      { 1, 0, 1, 1, 0, 1, 0, 0 },
 105         /* INFORM_SENT  */      { 1, 0, 1, 0, 1, 1, 1, 0 },
 106         /* DECLINING    */      { 1, 1, 1, 1, 0, 1, 0, 1 },
 107         /* RELEASING    */      { 1, 0, 1, 0, 0, 1, 0, 1 },
 108 };
 109 
 110 #define CMD_ISPRIV      0x1     /* Command requires privileges */
 111 #define CMD_CREATE      0x2     /* Command creates an interface */
 112 #define CMD_BOOTP       0x4     /* Command is valid with BOOTP */
 113 #define CMD_IMMED       0x8     /* Reply is immediate (no BUSY state) */
 114 
 115 static uint_t ipc_cmd_flags[DHCP_NIPC] = {
 116         /* DHCP_DROP */         CMD_ISPRIV|CMD_BOOTP,
 117         /* DHCP_EXTEND */       CMD_ISPRIV,
 118         /* DHCP_PING */         CMD_BOOTP|CMD_IMMED,
 119         /* DHCP_RELEASE */      CMD_ISPRIV,
 120         /* DHCP_START */        CMD_CREATE|CMD_ISPRIV|CMD_BOOTP,
 121         /* DHCP_STATUS */       CMD_BOOTP|CMD_IMMED,
 122         /* DHCP_INFORM */       CMD_CREATE|CMD_ISPRIV,
 123         /* DHCP_GET_TAG */      CMD_BOOTP|CMD_IMMED
 124 };
 125 
 126 static boolean_t is_iscsi_active(void);
 127 
 128 int
 129 main(int argc, char **argv)
 130 {
 131         boolean_t       is_daemon  = B_TRUE;
 132         boolean_t       is_verbose;
 133         int             ipc_fd;
 134         int             c;
 135         int             aware = RTAW_UNDER_IPMP;
 136         struct rlimit   rl;
 137 
 138         debug_level = df_get_int("", B_FALSE, DF_DEBUG_LEVEL);
 139         is_verbose = df_get_bool("", B_FALSE, DF_VERBOSE);
 140 
 141         /*
 142          * -l is ignored for compatibility with old agent.
 143          */
 144 
 145         while ((c = getopt(argc, argv, "vd:l:fa")) != EOF) {
 146 
 147                 switch (c) {
 148 
 149                 case 'a':
 150                         do_adopt = B_TRUE;
 151                         grandparent = getpid();
 152                         break;
 153 
 154                 case 'd':
 155                         debug_level = strtoul(optarg, NULL, 0);
 156                         break;
 157 
 158                 case 'f':
 159                         is_daemon = B_FALSE;
 160                         break;
 161 
 162                 case 'v':
 163                         is_verbose = B_TRUE;
 164                         break;
 165 
 166                 case '?':
 167                         (void) fprintf(stderr, "usage: %s [-a] [-d n] [-f] [-v]"
 168                             "\n", argv[0]);
 169                         return (EXIT_FAILURE);
 170 
 171                 default:
 172                         break;
 173                 }
 174         }
 175 
 176         (void) setlocale(LC_ALL, "");
 177         (void) textdomain(TEXT_DOMAIN);
 178 
 179         if (geteuid() != 0) {
 180                 dhcpmsg_init(argv[0], B_FALSE, is_verbose, debug_level);
 181                 dhcpmsg(MSG_ERROR, "must be super-user");
 182                 dhcpmsg_fini();
 183                 return (EXIT_FAILURE);
 184         }
 185 
 186         if (is_daemon && daemonize() == 0) {
 187                 dhcpmsg_init(argv[0], B_FALSE, is_verbose, debug_level);
 188                 dhcpmsg(MSG_ERR, "cannot become daemon, exiting");
 189                 dhcpmsg_fini();
 190                 return (EXIT_FAILURE);
 191         }
 192 
 193         /*
 194          * Seed the random number generator, since we're going to need it
 195          * to set transaction id's and for exponential backoff.
 196          */
 197         srand48(gethrtime() ^ gethostid() ^ getpid());
 198 
 199         dhcpmsg_init(argv[0], is_daemon, is_verbose, debug_level);
 200         (void) atexit(dhcpmsg_fini);
 201 
 202         tq = iu_tq_create();
 203         eh = iu_eh_create();
 204 
 205         if (eh == NULL || tq == NULL) {
 206                 errno = ENOMEM;
 207                 dhcpmsg(MSG_ERR, "cannot create timer queue or event handler");
 208                 return (EXIT_FAILURE);
 209         }
 210 
 211         /*
 212          * ignore most signals that could be reasonably generated.
 213          */
 214 
 215         (void) signal(SIGTERM, graceful_shutdown);
 216         (void) signal(SIGQUIT, graceful_shutdown);
 217         (void) signal(SIGPIPE, SIG_IGN);
 218         (void) signal(SIGUSR1, SIG_IGN);
 219         (void) signal(SIGUSR2, SIG_IGN);
 220         (void) signal(SIGINT,  SIG_IGN);
 221         (void) signal(SIGHUP,  SIG_IGN);
 222         (void) signal(SIGCHLD, SIG_IGN);
 223 
 224         /*
 225          * upon SIGTHAW we need to refresh any non-infinite leases.
 226          */
 227 
 228         (void) iu_eh_register_signal(eh, SIGTHAW, refresh_smachs, NULL);
 229 
 230         class_id = get_class_id();
 231         if (class_id != NULL)
 232                 class_id_len = strlen(class_id);
 233         else
 234                 dhcpmsg(MSG_WARNING, "get_class_id failed, continuing "
 235                     "with no vendor class id");
 236 
 237         /*
 238          * the inactivity timer is enabled any time there are no
 239          * interfaces under DHCP control.  if DHCP_INACTIVITY_WAIT
 240          * seconds transpire without an interface under DHCP control,
 241          * the agent shuts down.
 242          */
 243 
 244         inactivity_id = iu_schedule_timer(tq, DHCP_INACTIVITY_WAIT,
 245             inactivity_shutdown, NULL);
 246 
 247         /*
 248          * max out the number available descriptors, just in case..
 249          */
 250 
 251         rl.rlim_cur = RLIM_INFINITY;
 252         rl.rlim_max = RLIM_INFINITY;
 253         if (setrlimit(RLIMIT_NOFILE, &rl) == -1)
 254                 dhcpmsg(MSG_ERR, "setrlimit failed");
 255 
 256         (void) enable_extended_FILE_stdio(-1, -1);
 257 
 258         /*
 259          * Create and bind default IP sockets used to control interfaces and to
 260          * catch stray packets.
 261          */
 262 
 263         if (!dhcp_ip_default())
 264                 return (EXIT_FAILURE);
 265 
 266         /*
 267          * create the ipc channel that the agent will listen for
 268          * requests on, and register it with the event handler so that
 269          * `accept_event' will be called back.
 270          */
 271 
 272         switch (dhcp_ipc_init(&ipc_fd)) {
 273 
 274         case 0:
 275                 break;
 276 
 277         case DHCP_IPC_E_BIND:
 278                 dhcpmsg(MSG_ERROR, "dhcp_ipc_init: cannot bind to port "
 279                     "%i (agent already running?)", IPPORT_DHCPAGENT);
 280                 return (EXIT_FAILURE);
 281 
 282         default:
 283                 dhcpmsg(MSG_ERROR, "dhcp_ipc_init failed");
 284                 return (EXIT_FAILURE);
 285         }
 286 
 287         if (iu_register_event(eh, ipc_fd, POLLIN, accept_event, 0) == -1) {
 288                 dhcpmsg(MSG_ERR, "cannot register ipc fd for messages");
 289                 return (EXIT_FAILURE);
 290         }
 291 
 292         /*
 293          * Create the global routing socket.  This is used for monitoring
 294          * interface transitions, so that we learn about the kernel's Duplicate
 295          * Address Detection status, and for inserting and removing default
 296          * routes as learned from DHCP servers.  Both v4 and v6 are handed
 297          * with this one socket.
 298          */
 299         rtsock_fd = socket(PF_ROUTE, SOCK_RAW, 0);
 300         if (rtsock_fd == -1) {
 301                 dhcpmsg(MSG_ERR, "cannot open routing socket");
 302                 return (EXIT_FAILURE);
 303         }
 304 
 305         /*
 306          * We're IPMP-aware and can manage IPMP test addresses, so issue
 307          * RT_AWARE to get routing socket messages for interfaces under IPMP.
 308          */
 309         if (setsockopt(rtsock_fd, SOL_ROUTE, RT_AWARE, &aware,
 310             sizeof (aware)) == -1) {
 311                 dhcpmsg(MSG_ERR, "cannot set RT_AWARE on routing socket");
 312                 return (EXIT_FAILURE);
 313         }
 314 
 315         if (iu_register_event(eh, rtsock_fd, POLLIN, rtsock_event, 0) == -1) {
 316                 dhcpmsg(MSG_ERR, "cannot register routing socket for messages");
 317                 return (EXIT_FAILURE);
 318         }
 319 
 320         /*
 321          * if the -a (adopt) option was specified, try to adopt the
 322          * kernel-managed interface before we start.
 323          */
 324 
 325         if (do_adopt && !dhcp_adopt())
 326                 return (EXIT_FAILURE);
 327 
 328         /*
 329          * For DHCPv6, we own all of the interfaces marked DHCPRUNNING.  As
 330          * we're starting operation here, if there are any of those interfaces
 331          * lingering around, they're strays, and need to be removed.
 332          *
 333          * It might be nice to save these addresses off somewhere -- for both
 334          * v4 and v6 -- and use them as hints for later negotiation.
 335          */
 336         remove_v6_strays();
 337 
 338         /*
 339          * enter the main event loop; this is where all the real work
 340          * takes place (through registering events and scheduling timers).
 341          * this function only returns when the agent is shutting down.
 342          */
 343 
 344         switch (iu_handle_events(eh, tq)) {
 345 
 346         case -1:
 347                 dhcpmsg(MSG_WARNING, "iu_handle_events exited abnormally");
 348                 break;
 349 
 350         case DHCP_REASON_INACTIVITY:
 351                 dhcpmsg(MSG_INFO, "no interfaces to manage, shutting down...");
 352                 break;
 353 
 354         case DHCP_REASON_TERMINATE:
 355                 dhcpmsg(MSG_INFO, "received SIGTERM, shutting down...");
 356                 break;
 357 
 358         case DHCP_REASON_SIGNAL:
 359                 dhcpmsg(MSG_WARNING, "received unexpected signal, shutting "
 360                     "down...");
 361                 break;
 362         }
 363 
 364         (void) iu_eh_unregister_signal(eh, SIGTHAW, NULL);
 365 
 366         iu_eh_destroy(eh);
 367         iu_tq_destroy(tq);
 368 
 369         return (EXIT_SUCCESS);
 370 }
 371 
 372 /*
 373  * drain_script(): event loop callback during shutdown
 374  *
 375  *   input: eh_t *: unused
 376  *          void *: unused
 377  *  output: boolean_t: B_TRUE if event loop should exit; B_FALSE otherwise
 378  */
 379 
 380 /* ARGSUSED */
 381 boolean_t
 382 drain_script(iu_eh_t *ehp, void *arg)
 383 {
 384         if (shutdown_started == B_FALSE) {
 385                 shutdown_started = B_TRUE;
 386                 /*
 387                  * Check if the system is diskless client and/or
 388                  * there are active iSCSI sessions
 389                  *
 390                  * Do not drop the lease, or the system will be
 391                  * unable to sync(dump) through nfs/iSCSI driver
 392                  */
 393                 if (!do_adopt && !is_iscsi_active()) {
 394                         nuke_smach_list();
 395                 }
 396         }
 397         return (script_count == 0);
 398 }
 399 
 400 /*
 401  * accept_event(): accepts a new connection on the ipc socket and registers
 402  *                 to receive its messages with the event handler
 403  *
 404  *   input: iu_eh_t *: unused
 405  *          int: the file descriptor in the iu_eh_t * the connection came in on
 406  *          (other arguments unused)
 407  *  output: void
 408  */
 409 
 410 /* ARGSUSED */
 411 static void
 412 accept_event(iu_eh_t *ehp, int fd, short events, iu_event_id_t id, void *arg)
 413 {
 414         int     client_fd;
 415         int     is_priv;
 416 
 417         if (dhcp_ipc_accept(fd, &client_fd, &is_priv) != 0) {
 418                 dhcpmsg(MSG_ERR, "accept_event: accept on ipc socket");
 419                 return;
 420         }
 421 
 422         if (iu_register_event(eh, client_fd, POLLIN, ipc_event,
 423             (void *)is_priv) == -1) {
 424                 dhcpmsg(MSG_ERROR, "accept_event: cannot register ipc socket "
 425                     "for callback");
 426         }
 427 }
 428 
 429 /*
 430  * ipc_event(): processes incoming ipc requests
 431  *
 432  *   input: iu_eh_t *: unused
 433  *          int: the file descriptor in the iu_eh_t * the request came in on
 434  *          short: unused
 435  *          iu_event_id_t: event ID
 436  *          void *: indicates whether the request is from a privileged client
 437  *  output: void
 438  */
 439 
 440 /* ARGSUSED */
 441 static void
 442 ipc_event(iu_eh_t *ehp, int fd, short events, iu_event_id_t id, void *arg)
 443 {
 444         ipc_action_t            ia, *iap;
 445         dhcp_smach_t            *dsmp;
 446         int                     error, is_priv = (int)arg;
 447         const char              *ifname;
 448         boolean_t               isv6;
 449         boolean_t               dsm_created = B_FALSE;
 450 
 451         ipc_action_init(&ia);
 452         error = dhcp_ipc_recv_request(fd, &ia.ia_request,
 453             DHCP_IPC_REQUEST_WAIT);
 454         if (error != DHCP_IPC_SUCCESS) {
 455                 if (error != DHCP_IPC_E_EOF) {
 456                         dhcpmsg(MSG_ERROR,
 457                             "ipc_event: dhcp_ipc_recv_request failed: %s",
 458                             dhcp_ipc_strerror(error));
 459                 } else {
 460                         dhcpmsg(MSG_DEBUG, "ipc_event: connection closed");
 461                 }
 462                 if ((dsmp = lookup_smach_by_event(id)) != NULL) {
 463                         ipc_action_finish(dsmp, error);
 464                 } else {
 465                         (void) iu_unregister_event(eh, id, NULL);
 466                         (void) dhcp_ipc_close(fd);
 467                 }
 468                 return;
 469         }
 470 
 471         /* Fill in temporary ipc_action structure for utility functions */
 472         ia.ia_cmd = DHCP_IPC_CMD(ia.ia_request->message_type);
 473         ia.ia_fd = fd;
 474         ia.ia_eid = id;
 475 
 476         if (ia.ia_cmd >= DHCP_NIPC) {
 477                 dhcpmsg(MSG_ERROR,
 478                     "ipc_event: invalid command (%s) attempted on %s",
 479                     dhcp_ipc_type_to_string(ia.ia_cmd), ia.ia_request->ifname);
 480                 send_error_reply(&ia, DHCP_IPC_E_CMD_UNKNOWN);
 481                 return;
 482         }
 483 
 484         /* return EPERM for any of the privileged actions */
 485 
 486         if (!is_priv && (ipc_cmd_flags[ia.ia_cmd] & CMD_ISPRIV)) {
 487                 dhcpmsg(MSG_WARNING,
 488                     "ipc_event: privileged ipc command (%s) attempted on %s",
 489                     dhcp_ipc_type_to_string(ia.ia_cmd), ia.ia_request->ifname);
 490                 send_error_reply(&ia, DHCP_IPC_E_PERM);
 491                 return;
 492         }
 493 
 494         /*
 495          * Try to locate the state machine associated with this command.  If
 496          * the command is DHCP_START or DHCP_INFORM and there isn't a state
 497          * machine already, make one (there may already be one from a previous
 498          * failed attempt to START or INFORM).  Otherwise, verify the reference
 499          * is still valid.
 500          *
 501          * The interface name may be blank.  In that case, we look up the
 502          * primary interface, and the requested type (v4 or v6) doesn't matter.
 503          */
 504 
 505         isv6 = (ia.ia_request->message_type & DHCP_V6) != 0;
 506         ifname = ia.ia_request->ifname;
 507         if (*ifname == '\0')
 508                 dsmp = primary_smach(isv6);
 509         else
 510                 dsmp = lookup_smach(ifname, isv6);
 511 
 512         if (dsmp != NULL) {
 513                 /* Note that verify_smach drops a reference */
 514                 hold_smach(dsmp);
 515                 if (!verify_smach(dsmp))
 516                         dsmp = NULL;
 517         }
 518 
 519         if (dsmp == NULL) {
 520                 /*
 521                  * If the user asked for the primary DHCP interface by giving
 522                  * an empty string and there is no primary, then check if we're
 523                  * handling dhcpinfo.  If so, then simulate primary selection.
 524                  * Otherwise, report failure.
 525                  */
 526                 if (ifname[0] == '\0') {
 527                         if (ia.ia_cmd == DHCP_GET_TAG)
 528                                 dsmp = info_primary_smach(isv6);
 529                         if (dsmp == NULL)
 530                                 error = DHCP_IPC_E_NOPRIMARY;
 531 
 532                 /*
 533                  * If there's no interface, and we're starting up, then create
 534                  * it now, along with a state machine for it.  Note that if
 535                  * insert_smach fails, it discards the LIF reference.
 536                  */
 537                 } else if (ipc_cmd_flags[ia.ia_cmd] & CMD_CREATE) {
 538                         dhcp_lif_t *lif;
 539 
 540                         lif = attach_lif(ifname, isv6, &error);
 541                         if (lif != NULL &&
 542                             (dsmp = insert_smach(lif, &error)) != NULL) {
 543                                 /*
 544                                  * Get client ID for logical interface.  (V4
 545                                  * only, because V6 plumbs its own interfaces.)
 546                                  */
 547                                 error = get_smach_cid(dsmp);
 548                                 if (error != DHCP_IPC_SUCCESS) {
 549                                         remove_smach(dsmp);
 550                                         dsmp = NULL;
 551                                 }
 552                                 dsm_created = (dsmp != NULL);
 553                         }
 554 
 555                 /*
 556                  * Otherwise, this is an operation on an unknown interface.
 557                  */
 558                 } else {
 559                         error = DHCP_IPC_E_UNKIF;
 560                 }
 561                 if (dsmp == NULL) {
 562                         send_error_reply(&ia, error);
 563                         return;
 564                 }
 565         }
 566 
 567         /*
 568          * If this is a request for DHCP to manage a lease on an address,
 569          * ensure that IFF_DHCPRUNNING is set (we don't set this when the lif
 570          * is created because the lif may have been created for INFORM).
 571          */
 572         if (ia.ia_cmd == DHCP_START &&
 573             (error = set_lif_dhcp(dsmp->dsm_lif)) != DHCP_IPC_SUCCESS) {
 574                 if (dsm_created)
 575                         remove_smach(dsmp);
 576                 send_error_reply(&ia, error);
 577                 return;
 578         }
 579 
 580         if ((dsmp->dsm_dflags & DHCP_IF_BOOTP) &&
 581             !(ipc_cmd_flags[ia.ia_cmd] & CMD_BOOTP)) {
 582                 dhcpmsg(MSG_ERROR, "command %s not valid for BOOTP on %s",
 583                     dhcp_ipc_type_to_string(ia.ia_cmd), dsmp->dsm_name);
 584                 send_error_reply(&ia, DHCP_IPC_E_BOOTP);
 585                 return;
 586         }
 587 
 588         /*
 589          * verify that the state machine is in a state which will allow the
 590          * command.  we do this up front so that we can return an error
 591          * *before* needlessly cancelling an in-progress transaction.
 592          */
 593 
 594         if (!check_cmd_allowed(dsmp->dsm_state, ia.ia_cmd)) {
 595                 dhcpmsg(MSG_DEBUG,
 596                     "in state %s; not allowing %s command on %s",
 597                     dhcp_state_to_string(dsmp->dsm_state),
 598                     dhcp_ipc_type_to_string(ia.ia_cmd), dsmp->dsm_name);
 599                 send_error_reply(&ia,
 600                     ia.ia_cmd == DHCP_START && dsmp->dsm_state != INIT ?
 601                     DHCP_IPC_E_RUNNING : DHCP_IPC_E_OUTSTATE);
 602                 return;
 603         }
 604 
 605         dhcpmsg(MSG_DEBUG, "in state %s; allowing %s command on %s",
 606             dhcp_state_to_string(dsmp->dsm_state),
 607             dhcp_ipc_type_to_string(ia.ia_cmd), dsmp->dsm_name);
 608 
 609         if ((ia.ia_request->message_type & DHCP_PRIMARY) && is_priv)
 610                 make_primary(dsmp);
 611 
 612         /*
 613          * The current design dictates that there can be only one outstanding
 614          * transaction per state machine -- this simplifies the code
 615          * considerably and also fits well with RFCs 2131 and 3315.  It is
 616          * worth classifying the different DHCP commands into synchronous
 617          * (those which we will handle now and reply to immediately) and
 618          * asynchronous (those which require transactions and will be completed
 619          * at an indeterminate time in the future):
 620          *
 621          *    DROP: removes the agent's management of a state machine.
 622          *          asynchronous as the script program may be invoked.
 623          *
 624          *    PING: checks to see if the agent has a named state machine.
 625          *          synchronous, since no packets need to be sent
 626          *          to the DHCP server.
 627          *
 628          *  STATUS: returns information about a state machine.
 629          *          synchronous, since no packets need to be sent
 630          *          to the DHCP server.
 631          *
 632          * RELEASE: releases the agent's management of a state machine
 633          *          and brings the associated interfaces down.  asynchronous
 634          *          as the script program may be invoked.
 635          *
 636          *  EXTEND: renews a lease.  asynchronous, since the agent
 637          *          needs to wait for an ACK, etc.
 638          *
 639          *   START: starts DHCP on a named state machine.  asynchronous since
 640          *          the agent needs to wait for OFFERs, ACKs, etc.
 641          *
 642          *  INFORM: obtains configuration parameters for the system using
 643          *          externally configured interface.  asynchronous, since the
 644          *          agent needs to wait for an ACK.
 645          *
 646          * Notice that EXTEND, INFORM, START, DROP and RELEASE are
 647          * asynchronous.  Notice also that asynchronous commands may occur from
 648          * within the agent -- for instance, the agent will need to do implicit
 649          * EXTENDs to extend the lease. In order to make the code simpler, the
 650          * following rules apply for asynchronous commands:
 651          *
 652          * There can only be one asynchronous command at a time per state
 653          * machine.  The current asynchronous command is managed by the async_*
 654          * api: async_start(), async_finish(), and async_cancel().
 655          * async_start() starts management of a new asynchronous command on an
 656          * state machine, which should only be done after async_cancel() to
 657          * terminate a previous command.  When the command is completed,
 658          * async_finish() should be called.
 659          *
 660          * Asynchronous commands started by a user command have an associated
 661          * ipc_action which provides the agent with information for how to get
 662          * in touch with the user command when the action completes.  These
 663          * ipc_action records also have an associated timeout which may be
 664          * infinite.  ipc_action_start() should be called when starting an
 665          * asynchronous command requested by a user, which sets up the timer
 666          * and keeps track of the ipc information (file descriptor, request
 667          * type).  When the asynchronous command completes, ipc_action_finish()
 668          * should be called to return a command status code to the user and
 669          * close the ipc connection).  If the command does not complete before
 670          * the timer fires, ipc_action_timeout() is called which closes the ipc
 671          * connection and returns DHCP_IPC_E_TIMEOUT to the user.  Note that
 672          * independent of ipc_action_timeout(), ipc_action_finish() should be
 673          * called.
 674          *
 675          * on a case-by-case basis, here is what happens (per state machine):
 676          *
 677          *    o When an asynchronous command is requested, then
 678          *      async_cancel() is called to terminate any non-user
 679          *      action in progress.  If there's a user action running,
 680          *      the user command is sent DHCP_IPC_E_PEND.
 681          *
 682          *    o otherwise, the the transaction is started with
 683          *      async_start().  if the transaction is on behalf
 684          *      of a user, ipc_action_start() is called to keep
 685          *      track of the ipc information and set up the
 686          *      ipc_action timer.
 687          *
 688          *    o if the command completes normally and before a
 689          *      timeout fires, then async_finish() is called.
 690          *      if there was an associated ipc_action,
 691          *      ipc_action_finish() is called to complete it.
 692          *
 693          *    o if the command fails before a timeout fires, then
 694          *      async_finish() is called, and the state machine is
 695          *      is returned to a known state based on the command.
 696          *      if there was an associated ipc_action,
 697          *      ipc_action_finish() is called to complete it.
 698          *
 699          *    o if the ipc_action timer fires before command
 700          *      completion, then DHCP_IPC_E_TIMEOUT is returned to
 701          *      the user.  however, the transaction continues to
 702          *      be carried out asynchronously.
 703          */
 704 
 705         if (ipc_cmd_flags[ia.ia_cmd] & CMD_IMMED) {
 706                 /*
 707                  * Only immediate commands (ping, status, get_tag) need to
 708                  * worry about freeing ia through one of the reply functions
 709                  * before returning.
 710                  */
 711                 iap = &ia;
 712         } else {
 713                 /*
 714                  * if shutdown request has been received, send back an error.
 715                  */
 716                 if (shutdown_started) {
 717                         send_error_reply(&ia, DHCP_IPC_E_OUTSTATE);
 718                         return;
 719                 }
 720 
 721                 if (dsmp->dsm_dflags & DHCP_IF_BUSY) {
 722                         send_error_reply(&ia, DHCP_IPC_E_PEND);
 723                         return;
 724                 }
 725 
 726                 if (!ipc_action_start(dsmp, &ia)) {
 727                         dhcpmsg(MSG_WARNING, "ipc_event: ipc_action_start "
 728                             "failed for %s", dsmp->dsm_name);
 729                         send_error_reply(&ia, DHCP_IPC_E_MEMORY);
 730                         return;
 731                 }
 732 
 733                 /* Action structure consumed by above function */
 734                 iap = &dsmp->dsm_ia;
 735         }
 736 
 737         switch (iap->ia_cmd) {
 738 
 739         case DHCP_DROP:
 740                 if (dsmp->dsm_droprelease)
 741                         break;
 742                 dsmp->dsm_droprelease = B_TRUE;
 743 
 744                 /*
 745                  * Ensure that a timer associated with the existing state
 746                  * doesn't pop while we're waiting for the script to complete.
 747                  * (If so, chaos can result -- e.g., a timer causes us to end
 748                  * up in dhcp_selecting() would start acquiring a new lease on
 749                  * dsmp while our DHCP_DROP dismantling is ongoing.)
 750                  */
 751                 cancel_smach_timers(dsmp);
 752                 (void) script_start(dsmp, isv6 ? EVENT_DROP6 : EVENT_DROP,
 753                     dhcp_drop, NULL, NULL);
 754                 break;          /* not an immediate function */
 755 
 756         case DHCP_EXTEND:
 757                 (void) dhcp_extending(dsmp);
 758                 break;
 759 
 760         case DHCP_GET_TAG: {
 761                 dhcp_optnum_t   optnum;
 762                 void            *opt = NULL;
 763                 uint_t          optlen;
 764                 boolean_t       did_alloc = B_FALSE;
 765                 PKT_LIST        *ack = dsmp->dsm_ack;
 766                 int             i;
 767 
 768                 /*
 769                  * verify the request makes sense.
 770                  */
 771 
 772                 if (iap->ia_request->data_type   != DHCP_TYPE_OPTNUM ||
 773                     iap->ia_request->data_length != sizeof (dhcp_optnum_t)) {
 774                         send_error_reply(iap, DHCP_IPC_E_PROTO);
 775                         break;
 776                 }
 777 
 778                 (void) memcpy(&optnum, iap->ia_request->buffer,
 779                     sizeof (dhcp_optnum_t));
 780 
 781 load_option:
 782                 switch (optnum.category) {
 783 
 784                 case DSYM_SITE:                 /* FALLTHRU */
 785                 case DSYM_STANDARD:
 786                         for (i = 0; i < dsmp->dsm_pillen; i++) {
 787                                 if (dsmp->dsm_pil[i] == optnum.code)
 788                                         break;
 789                         }
 790                         if (i < dsmp->dsm_pillen)
 791                                 break;
 792                         if (isv6) {
 793                                 opt = dhcpv6_pkt_option(ack, NULL, optnum.code,
 794                                     NULL);
 795                         } else {
 796                                 if (optnum.code <= DHCP_LAST_OPT)
 797                                         opt = ack->opts[optnum.code];
 798                         }
 799                         break;
 800 
 801                 case DSYM_VENDOR:
 802                         if (isv6) {
 803                                 dhcpv6_option_t *d6o;
 804                                 uint32_t ent;
 805 
 806                                 /*
 807                                  * Look through vendor options to find our
 808                                  * enterprise number.
 809                                  */
 810                                 d6o = NULL;
 811                                 for (;;) {
 812                                         d6o = dhcpv6_pkt_option(ack, d6o,
 813                                             DHCPV6_OPT_VENDOR_OPT, &optlen);
 814                                         if (d6o == NULL)
 815                                                 break;
 816                                         optlen -= sizeof (*d6o);
 817                                         if (optlen < sizeof (ent))
 818                                                 continue;
 819                                         (void) memcpy(&ent, d6o + 1,
 820                                             sizeof (ent));
 821                                         if (ntohl(ent) != DHCPV6_SUN_ENT)
 822                                                 continue;
 823                                         break;
 824                                 }
 825                                 if (d6o != NULL) {
 826                                         /*
 827                                          * Now find the requested vendor option
 828                                          * within the vendor options block.
 829                                          */
 830                                         opt = dhcpv6_find_option(
 831                                             (char *)(d6o + 1) + sizeof (ent),
 832                                             optlen - sizeof (ent), NULL,
 833                                             optnum.code, NULL);
 834                                 }
 835                         } else {
 836                                 /*
 837                                  * the test against VS_OPTION_START is broken
 838                                  * up into two tests to avoid compiler warnings
 839                                  * under intel.
 840                                  */
 841                                 if ((optnum.code > VS_OPTION_START ||
 842                                     optnum.code == VS_OPTION_START) &&
 843                                     optnum.code <= VS_OPTION_END)
 844                                         opt = ack->vs[optnum.code];
 845                         }
 846                         break;
 847 
 848                 case DSYM_FIELD:
 849                         if (isv6) {
 850                                 dhcpv6_message_t *d6m =
 851                                     (dhcpv6_message_t *)ack->pkt;
 852                                 dhcpv6_option_t *d6o;
 853 
 854                                 /* Validate the packet field the user wants */
 855                                 optlen = optnum.code + optnum.size;
 856                                 if (d6m->d6m_msg_type ==
 857                                     DHCPV6_MSG_RELAY_FORW ||
 858                                     d6m->d6m_msg_type ==
 859                                     DHCPV6_MSG_RELAY_REPL) {
 860                                         if (optlen > sizeof (dhcpv6_relay_t))
 861                                                 break;
 862                                 } else {
 863                                         if (optlen > sizeof (*d6m))
 864                                                 break;
 865                                 }
 866 
 867                                 opt = malloc(sizeof (*d6o) + optnum.size);
 868                                 if (opt != NULL) {
 869                                         d6o = opt;
 870                                         d6o->d6o_code = htons(optnum.code);
 871                                         d6o->d6o_len = htons(optnum.size);
 872                                         (void) memcpy(d6o + 1, (caddr_t)d6m +
 873                                             optnum.code, optnum.size);
 874                                 }
 875                         } else {
 876                                 if (optnum.code + optnum.size > sizeof (PKT))
 877                                         break;
 878 
 879                                 /*
 880                                  * + 2 to account for option code and length
 881                                  * byte
 882                                  */
 883                                 opt = malloc(optnum.size + 2);
 884                                 if (opt != NULL) {
 885                                         DHCP_OPT *v4opt = opt;
 886 
 887                                         v4opt->len  = optnum.size;
 888                                         v4opt->code = optnum.code;
 889                                         (void) memcpy(v4opt->value,
 890                                             (caddr_t)ack->pkt + optnum.code,
 891                                             optnum.size);
 892                                 }
 893                         }
 894 
 895                         if (opt == NULL) {
 896                                 send_error_reply(iap, DHCP_IPC_E_MEMORY);
 897                                 return;
 898                         }
 899                         did_alloc = B_TRUE;
 900                         break;
 901 
 902                 default:
 903                         send_error_reply(iap, DHCP_IPC_E_PROTO);
 904                         return;
 905                 }
 906 
 907                 /*
 908                  * return the option payload, if there was one.  the "+ 2"
 909                  * accounts for the option code number and length byte.
 910                  */
 911 
 912                 if (opt != NULL) {
 913                         if (isv6) {
 914                                 dhcpv6_option_t d6ov;
 915 
 916                                 (void) memcpy(&d6ov, opt, sizeof (d6ov));
 917                                 optlen = ntohs(d6ov.d6o_len) + sizeof (d6ov);
 918                         } else {
 919                                 optlen = ((DHCP_OPT *)opt)->len + 2;
 920                         }
 921                         send_data_reply(iap, 0, DHCP_TYPE_OPTION, opt, optlen);
 922 
 923                         if (did_alloc)
 924                                 free(opt);
 925                         break;
 926                 } else if (ack != dsmp->dsm_orig_ack) {
 927                         /*
 928                          * There wasn't any definition for the option in the
 929                          * current ack, so now retry with the original ack if
 930                          * the original ack is not the current ack.
 931                          */
 932                         ack = dsmp->dsm_orig_ack;
 933                         goto load_option;
 934                 }
 935 
 936                 /*
 937                  * note that an "okay" response is returned either in
 938                  * the case of an unknown option or a known option
 939                  * with no payload.  this is okay (for now) since
 940                  * dhcpinfo checks whether an option is valid before
 941                  * ever performing ipc with the agent.
 942                  */
 943 
 944                 send_ok_reply(iap);
 945                 break;
 946         }
 947 
 948         case DHCP_INFORM:
 949                 dhcp_inform(dsmp);
 950                 /* next destination: dhcp_acknak() */
 951                 break;          /* not an immediate function */
 952 
 953         case DHCP_PING:
 954                 if (dsmp->dsm_dflags & DHCP_IF_FAILED)
 955                         send_error_reply(iap, DHCP_IPC_E_FAILEDIF);
 956                 else
 957                         send_ok_reply(iap);
 958                 break;
 959 
 960         case DHCP_RELEASE:
 961                 if (dsmp->dsm_droprelease)
 962                         break;
 963                 dsmp->dsm_droprelease = B_TRUE;
 964                 cancel_smach_timers(dsmp); /* see comment in DHCP_DROP above */
 965                 (void) script_start(dsmp, isv6 ? EVENT_RELEASE6 :
 966                     EVENT_RELEASE, dhcp_release, "Finished with lease.", NULL);
 967                 break;          /* not an immediate function */
 968 
 969         case DHCP_START: {
 970                 PKT_LIST *ack, *oack;
 971                 PKT_LIST *plp[2];
 972 
 973                 deprecate_leases(dsmp);
 974 
 975                 /*
 976                  * if we have a valid hostconf lying around, then jump
 977                  * into INIT_REBOOT.  if it fails, we'll end up going
 978                  * through the whole selecting() procedure again.
 979                  */
 980 
 981                 error = read_hostconf(dsmp->dsm_name, plp, 2, dsmp->dsm_isv6);
 982                 ack = error > 0 ? plp[0] : NULL;
 983                 oack = error > 1 ? plp[1] : NULL;
 984 
 985                 /*
 986                  * If the allocation of the old ack fails, that's fine;
 987                  * continue without it.
 988                  */
 989                 if (oack == NULL)
 990                         oack = ack;
 991 
 992                 /*
 993                  * As long as we've allocated something, start using it.
 994                  */
 995                 if (ack != NULL) {
 996                         dsmp->dsm_orig_ack = oack;
 997                         dsmp->dsm_ack = ack;
 998                         dhcp_init_reboot(dsmp);
 999                         /* next destination: dhcp_acknak() */
1000                         break;
1001                 }
1002 
1003                 /*
1004                  * if not debugging, wait for a few seconds before
1005                  * going into SELECTING.
1006                  */
1007 
1008                 if (debug_level == 0 && set_start_timer(dsmp)) {
1009                         /* next destination: dhcp_start() */
1010                         break;
1011                 } else {
1012                         dhcp_selecting(dsmp);
1013                         /* next destination: dhcp_requesting() */
1014                         break;
1015                 }
1016         }
1017 
1018         case DHCP_STATUS: {
1019                 dhcp_status_t   status;
1020                 dhcp_lease_t    *dlp;
1021 
1022                 status.if_began = monosec_to_time(dsmp->dsm_curstart_monosec);
1023 
1024                 /*
1025                  * We return information on just the first lease as being
1026                  * representative of the lot.  A better status mechanism is
1027                  * needed.
1028                  */
1029                 dlp = dsmp->dsm_leases;
1030 
1031                 if (dlp == NULL ||
1032                     dlp->dl_lifs->lif_expire.dt_start == DHCP_PERM) {
1033                         status.if_t1    = DHCP_PERM;
1034                         status.if_t2    = DHCP_PERM;
1035                         status.if_lease = DHCP_PERM;
1036                 } else {
1037                         status.if_t1    = status.if_began +
1038                             dlp->dl_t1.dt_start;
1039                         status.if_t2    = status.if_began +
1040                             dlp->dl_t2.dt_start;
1041                         status.if_lease = status.if_began +
1042                             dlp->dl_lifs->lif_expire.dt_start;
1043                 }
1044 
1045                 status.version          = DHCP_STATUS_VER;
1046                 status.if_state         = dsmp->dsm_state;
1047                 status.if_dflags        = dsmp->dsm_dflags;
1048                 status.if_sent          = dsmp->dsm_sent;
1049                 status.if_recv          = dsmp->dsm_received;
1050                 status.if_bad_offers    = dsmp->dsm_bad_offers;
1051 
1052                 (void) strlcpy(status.if_name, dsmp->dsm_name, LIFNAMSIZ);
1053 
1054                 send_data_reply(iap, 0, DHCP_TYPE_STATUS, &status,
1055                     sizeof (dhcp_status_t));
1056                 break;
1057         }
1058         }
1059 }
1060 
1061 /*
1062  * check_rtm_addr(): determine if routing socket message matches interface
1063  *                   address
1064  *
1065  *   input: const struct if_msghdr *: pointer to routing socket message
1066  *          int: routing socket message length
1067  *          boolean_t: set to B_TRUE if IPv6
1068  *          const in6_addr_t *: pointer to IP address
1069  *  output: boolean_t: B_TRUE if address is a match
1070  */
1071 
1072 static boolean_t
1073 check_rtm_addr(const struct ifa_msghdr *ifam, int msglen, boolean_t isv6,
1074     const in6_addr_t *addr)
1075 {
1076         const char *cp, *lim;
1077         uint_t flag;
1078         const struct sockaddr *sa;
1079 
1080         if (!(ifam->ifam_addrs & RTA_IFA))
1081                 return (B_FALSE);
1082 
1083         cp = (const char *)(ifam + 1);
1084         lim = (const char *)ifam + msglen;
1085         for (flag = 1; flag < RTA_IFA; flag <<= 1) {
1086                 if (ifam->ifam_addrs & flag) {
1087                         /* LINTED: alignment */
1088                         sa = (const struct sockaddr *)cp;
1089                         if ((const char *)(sa + 1) > lim)
1090                                 return (B_FALSE);
1091                         switch (sa->sa_family) {
1092                         case AF_INET:
1093                                 cp += sizeof (struct sockaddr_in);
1094                                 break;
1095                         case AF_LINK:
1096                                 cp += sizeof (struct sockaddr_dl);
1097                                 break;
1098                         case AF_INET6:
1099                                 cp += sizeof (struct sockaddr_in6);
1100                                 break;
1101                         default:
1102                                 cp += sizeof (struct sockaddr);
1103                                 break;
1104                         }
1105                 }
1106         }
1107         if (isv6) {
1108                 const struct sockaddr_in6 *sin6;
1109 
1110                 /* LINTED: alignment */
1111                 sin6 = (const struct sockaddr_in6 *)cp;
1112                 if ((const char *)(sin6 + 1) > lim)
1113                         return (B_FALSE);
1114                 if (sin6->sin6_family != AF_INET6)
1115                         return (B_FALSE);
1116                 return (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, addr));
1117         } else {
1118                 const struct sockaddr_in *sinp;
1119                 ipaddr_t v4addr;
1120 
1121                 /* LINTED: alignment */
1122                 sinp = (const struct sockaddr_in *)cp;
1123                 if ((const char *)(sinp + 1) > lim)
1124                         return (B_FALSE);
1125                 if (sinp->sin_family != AF_INET)
1126                         return (B_FALSE);
1127                 IN6_V4MAPPED_TO_IPADDR(addr, v4addr);
1128                 return (sinp->sin_addr.s_addr == v4addr);
1129         }
1130 }
1131 
1132 /*
1133  * is_rtm_v6(): determine if routing socket message is IPv6
1134  *
1135  *   input: struct ifa_msghdr *: pointer to routing socket message
1136  *          int: message length
1137  *  output: boolean_t
1138  */
1139 
1140 static boolean_t
1141 is_rtm_v6(const struct ifa_msghdr *ifam, int msglen)
1142 {
1143         const char *cp, *lim;
1144         uint_t flag;
1145         const struct sockaddr *sa;
1146 
1147         cp = (const char *)(ifam + 1);
1148         lim = (const char *)ifam + msglen;
1149         for (flag = ifam->ifam_addrs; flag != 0; flag &= flag - 1) {
1150                 /* LINTED: alignment */
1151                 sa = (const struct sockaddr *)cp;
1152                 if ((const char *)(sa + 1) > lim)
1153                         return (B_FALSE);
1154                 switch (sa->sa_family) {
1155                 case AF_INET:
1156                         return (B_FALSE);
1157                 case AF_LINK:
1158                         cp += sizeof (struct sockaddr_dl);
1159                         break;
1160                 case AF_INET6:
1161                         return (B_TRUE);
1162                 default:
1163                         cp += sizeof (struct sockaddr);
1164                         break;
1165                 }
1166         }
1167         return (B_FALSE);
1168 }
1169 
1170 /*
1171  * check_lif(): check the state of a given logical interface and its DHCP
1172  *              lease.  We've been told by the routing socket that the
1173  *              corresponding ifIndex has changed.  This may mean that DAD has
1174  *              completed or failed.
1175  *
1176  *   input: dhcp_lif_t *: pointer to the LIF
1177  *          const struct ifa_msghdr *: routing socket message
1178  *          int: size of routing socket message
1179  *  output: boolean_t: B_TRUE if DAD has completed on this interface
1180  */
1181 
1182 static boolean_t
1183 check_lif(dhcp_lif_t *lif, const struct ifa_msghdr *ifam, int msglen)
1184 {
1185         boolean_t isv6, dad_wait, unplumb;
1186         int fd;
1187         struct lifreq lifr;
1188 
1189         isv6 = lif->lif_pif->pif_isv6;
1190         fd = isv6 ? v6_sock_fd : v4_sock_fd;
1191 
1192         /*
1193          * Get the real (64 bit) logical interface flags.  Note that the
1194          * routing socket message has flags, but these are just the lower 32
1195          * bits.
1196          */
1197         unplumb = B_FALSE;
1198         (void) memset(&lifr, 0, sizeof (lifr));
1199         (void) strlcpy(lifr.lifr_name, lif->lif_name, sizeof (lifr.lifr_name));
1200         if (ioctl(fd, SIOCGLIFFLAGS, &lifr) == -1) {
1201                 /*
1202                  * Failing to retrieve flags means that the interface is gone.
1203                  * It hasn't failed to verify with DAD, but we still have to
1204                  * give up on it.
1205                  */
1206                 lifr.lifr_flags = 0;
1207                 if (errno == ENXIO) {
1208                         lif->lif_plumbed = B_FALSE;
1209                         dhcpmsg(MSG_INFO, "%s has been removed; abandoning",
1210                             lif->lif_name);
1211                         if (!isv6)
1212                                 discard_default_routes(lif->lif_smachs);
1213                 } else {
1214                         dhcpmsg(MSG_ERR,
1215                             "unable to retrieve interface flags on %s",
1216                             lif->lif_name);
1217                 }
1218                 unplumb = B_TRUE;
1219         } else if (!check_rtm_addr(ifam, msglen, isv6, &lif->lif_v6addr)) {
1220                 /*
1221                  * If the message is not about this logical interface,
1222                  * then just ignore it.
1223                  */
1224                 return (B_FALSE);
1225         } else if (lifr.lifr_flags & IFF_DUPLICATE) {
1226                 dhcpmsg(MSG_ERROR, "interface %s has duplicate address",
1227                     lif->lif_name);
1228                 lif_mark_decline(lif, "duplicate address");
1229                 close_ip_lif(lif);
1230                 (void) open_ip_lif(lif, INADDR_ANY, B_TRUE);
1231         }
1232 
1233         dad_wait = lif->lif_dad_wait;
1234         if (dad_wait) {
1235                 dhcpmsg(MSG_VERBOSE, "check_lif: %s has finished DAD",
1236                     lif->lif_name);
1237                 lif->lif_dad_wait = B_FALSE;
1238         }
1239 
1240         if (unplumb)
1241                 unplumb_lif(lif);
1242 
1243         return (dad_wait);
1244 }
1245 
1246 /*
1247  * check_main_lif(): check the state of a main logical interface for a state
1248  *                   machine.  This is used only for DHCPv6.
1249  *
1250  *   input: dhcp_smach_t *: pointer to the state machine
1251  *          const struct ifa_msghdr *: routing socket message
1252  *          int: size of routing socket message
1253  *  output: boolean_t: B_TRUE if LIF is ok.
1254  */
1255 
1256 static boolean_t
1257 check_main_lif(dhcp_smach_t *dsmp, const struct ifa_msghdr *ifam, int msglen)
1258 {
1259         dhcp_lif_t *lif = dsmp->dsm_lif;
1260         struct lifreq lifr;
1261 
1262         /*
1263          * Get the real (64 bit) logical interface flags.  Note that the
1264          * routing socket message has flags, but these are just the lower 32
1265          * bits.
1266          */
1267         (void) memset(&lifr, 0, sizeof (lifr));
1268         (void) strlcpy(lifr.lifr_name, lif->lif_name, sizeof (lifr.lifr_name));
1269         if (ioctl(v6_sock_fd, SIOCGLIFFLAGS, &lifr) == -1) {
1270                 /*
1271                  * Failing to retrieve flags means that the interface is gone.
1272                  * Our state machine is now trash.
1273                  */
1274                 if (errno == ENXIO) {
1275                         dhcpmsg(MSG_INFO, "%s has been removed; abandoning",
1276                             lif->lif_name);
1277                 } else {
1278                         dhcpmsg(MSG_ERR,
1279                             "unable to retrieve interface flags on %s",
1280                             lif->lif_name);
1281                 }
1282                 return (B_FALSE);
1283         } else if (!check_rtm_addr(ifam, msglen, B_TRUE, &lif->lif_v6addr)) {
1284                 /*
1285                  * If the message is not about this logical interface,
1286                  * then just ignore it.
1287                  */
1288                 return (B_TRUE);
1289         } else if (lifr.lifr_flags & IFF_DUPLICATE) {
1290                 dhcpmsg(MSG_ERROR, "interface %s has duplicate address",
1291                     lif->lif_name);
1292                 return (B_FALSE);
1293         } else {
1294                 return (B_TRUE);
1295         }
1296 }
1297 
1298 /*
1299  * process_link_up_down(): check the state of a physical interface for up/down
1300  *                         transitions; must go through INIT_REBOOT state if
1301  *                         the link flaps.
1302  *
1303  *   input: dhcp_pif_t *: pointer to the physical interface to check
1304  *          const struct if_msghdr *: routing socket message
1305  *  output: none
1306  */
1307 
1308 static void
1309 process_link_up_down(dhcp_pif_t *pif, const struct if_msghdr *ifm)
1310 {
1311         struct lifreq lifr;
1312         boolean_t isv6;
1313         int fd;
1314 
1315         /*
1316          * If the message implies no change of flags, then we're done; no need
1317          * to check further.  Note that if we have multiple state machines on a
1318          * single physical interface, this test keeps us from issuing an ioctl
1319          * for each one.
1320          */
1321         if ((ifm->ifm_flags & IFF_RUNNING) && pif->pif_running ||
1322             !(ifm->ifm_flags & IFF_RUNNING) && !pif->pif_running)
1323                 return;
1324 
1325         /*
1326          * We don't know what the real interface flags are, because the
1327          * if_index number is only 16 bits; we must go ask.
1328          */
1329         isv6 = pif->pif_isv6;
1330         fd = isv6 ? v6_sock_fd : v4_sock_fd;
1331         (void) memset(&lifr, 0, sizeof (lifr));
1332         (void) strlcpy(lifr.lifr_name, pif->pif_name, sizeof (lifr.lifr_name));
1333 
1334         if (ioctl(fd, SIOCGLIFFLAGS, &lifr) == -1 ||
1335             !(lifr.lifr_flags & IFF_RUNNING)) {
1336                 /*
1337                  * If we've lost the interface or it has gone down, then
1338                  * nothing special to do; just turn off the running flag.
1339                  */
1340                 pif_status(pif, B_FALSE);
1341         } else {
1342                 /*
1343                  * Interface has come back up: go through verification process.
1344                  */
1345                 pif_status(pif, B_TRUE);
1346         }
1347 }
1348 
1349 /*
1350  * rtsock_event(): fetches routing socket messages and updates internal
1351  *                 interface state based on those messages.
1352  *
1353  *   input: iu_eh_t *: unused
1354  *          int: the routing socket file descriptor
1355  *          (other arguments unused)
1356  *  output: void
1357  */
1358 
1359 /* ARGSUSED */
1360 static void
1361 rtsock_event(iu_eh_t *ehp, int fd, short events, iu_event_id_t id, void *arg)
1362 {
1363         dhcp_smach_t *dsmp, *dsmnext;
1364         union {
1365                 struct ifa_msghdr ifam;
1366                 struct if_msghdr ifm;
1367                 char buf[1024];
1368         } msg;
1369         uint16_t ifindex;
1370         int msglen;
1371         boolean_t isv6;
1372 
1373         if ((msglen = read(fd, &msg, sizeof (msg))) <= 0)
1374                 return;
1375 
1376         /* Note that the routing socket interface index is just 16 bits */
1377         if (msg.ifm.ifm_type == RTM_IFINFO) {
1378                 ifindex = msg.ifm.ifm_index;
1379                 isv6 = (msg.ifm.ifm_flags & IFF_IPV6) ? B_TRUE : B_FALSE;
1380         } else if (msg.ifam.ifam_type == RTM_DELADDR ||
1381             msg.ifam.ifam_type == RTM_NEWADDR) {
1382                 ifindex = msg.ifam.ifam_index;
1383                 isv6 = is_rtm_v6(&msg.ifam, msglen);
1384         } else {
1385                 return;
1386         }
1387 
1388         for (dsmp = lookup_smach_by_uindex(ifindex, NULL, isv6);
1389             dsmp != NULL; dsmp = dsmnext) {
1390                 DHCPSTATE oldstate;
1391                 boolean_t lif_finished;
1392                 boolean_t lease_removed;
1393                 dhcp_lease_t *dlp, *dlnext;
1394 
1395                 /*
1396                  * Note that script_start can call dhcp_drop directly, and
1397                  * that will do release_smach.
1398                  */
1399                 dsmnext = lookup_smach_by_uindex(ifindex, dsmp, isv6);
1400                 oldstate = dsmp->dsm_state;
1401 
1402                 /*
1403                  * Ignore state machines that are currently processing drop or
1404                  * release; there is nothing more we can do for them.
1405                  */
1406                 if (dsmp->dsm_droprelease)
1407                         continue;
1408 
1409                 /*
1410                  * Look for link up/down notifications.  These occur on a
1411                  * physical interface basis.
1412                  */
1413                 if (msg.ifm.ifm_type == RTM_IFINFO) {
1414                         process_link_up_down(dsmp->dsm_lif->lif_pif, &msg.ifm);
1415                         continue;
1416                 }
1417 
1418                 /*
1419                  * Since we cannot trust the flags reported by the routing
1420                  * socket (they're just 32 bits -- and thus never include
1421                  * IFF_DUPLICATE), and we can't trust the ifindex (it's only 16
1422                  * bits and also doesn't reflect the alias in use), we get
1423                  * flags on all matching interfaces, and go by that.
1424                  */
1425                 lif_finished = B_FALSE;
1426                 lease_removed = B_FALSE;
1427                 for (dlp = dsmp->dsm_leases; dlp != NULL; dlp = dlnext) {
1428                         dhcp_lif_t *lif, *lifnext;
1429                         uint_t nlifs = dlp->dl_nlifs;
1430 
1431                         dlnext = dlp->dl_next;
1432                         for (lif = dlp->dl_lifs; lif != NULL && nlifs > 0;
1433                             lif = lifnext, nlifs--) {
1434                                 lifnext = lif->lif_next;
1435                                 if (check_lif(lif, &msg.ifam, msglen)) {
1436                                         dsmp->dsm_lif_wait--;
1437                                         lif_finished = B_TRUE;
1438                                 }
1439                         }
1440                         if (dlp->dl_nlifs == 0) {
1441                                 remove_lease(dlp);
1442                                 lease_removed = B_TRUE;
1443                         }
1444                 }
1445 
1446                 if ((isv6 && !check_main_lif(dsmp, &msg.ifam, msglen)) ||
1447                     (!isv6 && !verify_lif(dsmp->dsm_lif))) {
1448                         finished_smach(dsmp, DHCP_IPC_E_INVIF);
1449                         continue;
1450                 }
1451 
1452                 /*
1453                  * Ignore this state machine if nothing interesting has
1454                  * happened.
1455                  */
1456                 if (!lif_finished && dsmp->dsm_lif_down == 0 &&
1457                     (dsmp->dsm_leases != NULL || !lease_removed))
1458                         continue;
1459 
1460                 /*
1461                  * If we're still waiting for DAD to complete on some of the
1462                  * configured LIFs, then don't send a response.
1463                  */
1464                 if (dsmp->dsm_lif_wait != 0) {
1465                         dhcpmsg(MSG_VERBOSE, "rtsock_event: %s still has %d "
1466                             "LIFs waiting on DAD", dsmp->dsm_name,
1467                             dsmp->dsm_lif_wait);
1468                         continue;
1469                 }
1470 
1471                 /*
1472                  * If we have some failed LIFs, then handle them now.  We'll
1473                  * remove them from the list.  Any leases that become empty are
1474                  * also removed as part of the decline-generation process.
1475                  */
1476                 if (dsmp->dsm_lif_down != 0)
1477                         send_declines(dsmp);
1478 
1479                 if (dsmp->dsm_leases == NULL) {
1480                         dsmp->dsm_bad_offers++;
1481                         /*
1482                          * For DHCPv6, we'll process the restart once we're
1483                          * done sending Decline messages, because these are
1484                          * supposed to be acknowledged.  With DHCPv4, there's
1485                          * no acknowledgment for a DECLINE, so after sending
1486                          * it, we just restart right away.
1487                          */
1488                         if (!dsmp->dsm_isv6) {
1489                                 dhcpmsg(MSG_VERBOSE, "rtsock_event: %s has no "
1490                                     "LIFs left", dsmp->dsm_name);
1491                                 dhcp_restart(dsmp);
1492                         }
1493                 } else {
1494                         /*
1495                          * If we're now up on at least some of the leases and
1496                          * we were waiting for that, then kick off the rest of
1497                          * configuration.  Lease validation and DAD are done.
1498                          */
1499                         dhcpmsg(MSG_VERBOSE, "rtsock_event: all LIFs verified "
1500                             "on %s in %s state", dsmp->dsm_name,
1501                             dhcp_state_to_string(oldstate));
1502                         if (oldstate == PRE_BOUND ||
1503                             oldstate == ADOPTING)
1504                                 dhcp_bound_complete(dsmp);
1505                         if (oldstate == ADOPTING)
1506                                 dhcp_adopt_complete(dsmp);
1507                 }
1508         }
1509 }
1510 
1511 /*
1512  * check_cmd_allowed(): check whether the requested command is allowed in the
1513  *                      state specified.
1514  *
1515  *   input: DHCPSTATE: current state
1516  *          dhcp_ipc_type_t: requested command
1517  *  output: boolean_t: B_TRUE if command is allowed in this state
1518  */
1519 
1520 boolean_t
1521 check_cmd_allowed(DHCPSTATE state, dhcp_ipc_type_t cmd)
1522 {
1523         return (ipc_cmd_allowed[state][cmd] != 0);
1524 }
1525 
1526 static boolean_t
1527 is_iscsi_active(void)
1528 {
1529         int fd;
1530         int active = 0;
1531 
1532         if ((fd = open(ISCSI_DRIVER_DEVCTL, O_RDONLY)) != -1) {
1533                 if (ioctl(fd, ISCSI_IS_ACTIVE, &active) != 0)
1534                         active = 0;
1535                 (void) close(fd);
1536         }
1537 
1538         return (active != 0);
1539 }