sbin/dhclient/dhclient.c

   1 /*      $OpenBSD: src/sbin/dhclient/dhclient.c,v 1.128 2009/06/03 02:05:34 stevesk Exp $        */
   2
   3 /*
   4  * Copyright 2004 Henning Brauer <henning@openbsd.org>
   5  * Copyright (c) 1995, 1996, 1997, 1998, 1999
   6  * The Internet Software Consortium.    All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of The Internet Software Consortium nor the names
  18  *    of its contributors may be used to endorse or promote products derived
  19  *    from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
  22  * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  23  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  25  * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
  26  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  28  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  29  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  30  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  * This software has been written for the Internet Software Consortium
  36  * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
  37  * Enterprises.  To learn more about the Internet Software Consortium,
  38  * see ``http://www.vix.com/isc''.  To learn more about Vixie
  39  * Enterprises, see ``http://www.vix.com''.
  40  *
  41  * This client was substantially modified and enhanced by Elliot Poger
  42  * for use on Linux while he was working on the MosquitoNet project at
  43  * Stanford.
  44  *
  45  * The current version owes much to Elliot's Linux enhancements, but
  46  * was substantially reorganized and partially rewritten by Ted Lemon
  47  * so as to use the same networking framework that the Internet Software
  48  * Consortium DHCP server uses.   Much system-specific configuration code
  49  * was moved into a shell script so that as support for more operating
  50  * systems is added, it will not be necessary to port and maintain
  51  * system-specific configuration code to these operating systems - instead,
  52  * the shell script can invoke the native tools to accomplish the same
  53  * purpose.
  54  */
  55
  56 #include <ctype.h>
  57 #include <poll.h>
  58 #include <pwd.h>
  59 #include <unistd.h>
  60
  61 #include "dhcpd.h"
  62 #include "privsep.h"
  63
  64 #define CLIENT_PATH             "PATH=/usr/bin:/usr/sbin:/bin:/sbin"
  65 #define DEFAULT_LEASE_TIME      43200   /* 12 hours... */
  66 #define TIME_MAX                2147483647
  67 #define POLL_FAILURES           10
  68 #define POLL_FAILURE_WAIT       1       /* Back off multiplier (seconds) */
  69
  70 time_t cur_time;
  71
  72 char *path_dhclient_conf = _PATH_DHCLIENT_CONF;
  73 char *path_dhclient_db = NULL;
  74
  75 int log_perror = 1;
  76 int privfd;
  77 int nullfd = -1;
  78 int no_daemon;
  79 int unknown_ok = 1;
  80 int routefd = -1;
  81
  82 struct iaddr iaddr_broadcast = { 4, { 255, 255, 255, 255 } };
  83 struct in_addr inaddr_any;
  84 struct sockaddr_in sockaddr_broadcast;
  85
  86 struct interface_info *ifi;
  87 struct client_state *client;
  88 struct client_config *config;
  89
  90 int              findproto(char *, int);
  91 struct sockaddr *get_ifa(char *, int);
  92 void             usage(void);
  93 int              check_option(struct client_lease *l, int option);
  94 int              ipv4addrs(char * buf);
  95 int              res_hnok(const char *dn);
  96 char            *option_as_string(unsigned int code, unsigned char *data, int len);
  97 int              fork_privchld(int, int);
  98
  99 #define ROUNDUP(a) \
 100             ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
 101 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
 102
 103 time_t  scripttime;
 104 static FILE *leaseFile;
 105
 106 int
 107 findproto(char *cp, int n)
 108 {
 109         struct sockaddr *sa;
 110         int i;
 111
 112         if (n == 0)
 113                 return -1;
 114         for (i = 1; i; i <<= 1) {
 115                 if (i & n) {
 116                         sa = (struct sockaddr *)cp;
 117                         switch (i) {
 118                         case RTA_IFA:
 119                         case RTA_DST:
 120                         case RTA_GATEWAY:
 121                         case RTA_NETMASK:
 122                                 if (sa->sa_family == AF_INET)
 123                                         return AF_INET;
 124                                 if (sa->sa_family == AF_INET6)
 125                                         return AF_INET6;
 126                                 break;
 127                         case RTA_IFP:
 128                                 break;
 129                         }
 130                         ADVANCE(cp, sa);
 131                 }
 132         }
 133         return (-1);
 134 }
 135
 136 struct sockaddr *
 137 get_ifa(char *cp, int n)
 138 {
 139         struct sockaddr *sa;
 140         int i;
 141
 142         if (n == 0)
 143                 return (NULL);
 144         for (i = 1; i; i <<= 1)
 145                 if (i & n) {
 146                         sa = (struct sockaddr *)cp;
 147                         if (i == RTA_IFA)
 148                                 return (sa);
 149                         ADVANCE(cp, sa);
 150                 }
 151
 152         return (NULL);
 153 }
 154 struct iaddr defaddr = { .len = 4 }; /* NULL is for silence warnings */
 155
 156 void
 157 routehandler(void)
 158 {
 159         int linkstat;
 160         char msg[2048];
 161         struct rt_msghdr *rtm;
 162         struct if_msghdr *ifm;
 163         struct ifa_msghdr *ifam;
 164         struct if_announcemsghdr *ifan;
 165         struct client_lease *l;
 166         time_t t = time(NULL);
 167         struct sockaddr *sa;
 168         struct iaddr a;
 169         ssize_t n;
 170         char *errmsg, buf[64];
 171
 172         do {
 173                 n = read(routefd, &msg, sizeof(msg));
 174         } while (n == -1 && errno == EINTR);
 175
 176         rtm = (struct rt_msghdr *)msg;
 177         if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen ||
 178             rtm->rtm_version != RTM_VERSION)
 179                 return;
 180
 181         switch (rtm->rtm_type) {
 182         case RTM_NEWADDR:
 183                 ifam = (struct ifa_msghdr *)rtm;
 184                 if (ifam->ifam_index != ifi->index)
 185                         break;
 186                 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
 187                         break;
 188                 sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs);
 189                 if (sa == NULL) {
 190                         errmsg = "sa == NULL";
 191                         goto die;
 192                 }
 193
 194                 if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf))
 195                         error("king bula sez: len mismatch");
 196                 memcpy(a.iabuf, &((struct sockaddr_in *)sa)->sin_addr, a.len);
 197                 if (addr_eq(a, defaddr))
 198                         break;
 199
 200                 for (l = client->active; l != NULL; l = l->next)
 201                         if (addr_eq(a, l->address))
 202                                 break;
 203
 204                 if (l != NULL || (client->alias &&
 205                     addr_eq(a, client->alias->address)))
 206                         /* new addr is the one we set */
 207                         break;
 208                 snprintf(buf, sizeof(buf), "%s: %s",
 209                     "new address not one we set", piaddr(a));
 210                 errmsg = buf;
 211                 goto die;
 212         case RTM_DELADDR:
 213                 ifam = (struct ifa_msghdr *)rtm;
 214                 if (ifam->ifam_index != ifi->index)
 215                         break;
 216                 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
 217                         break;
 218                 if (scripttime == 0 || t < scripttime + 10)
 219                         break;
 220                 errmsg = "interface address deleted";
 221                 goto die;
 222         case RTM_IFINFO:
 223                 ifm = (struct if_msghdr *)rtm;
 224                 if (ifm->ifm_index != ifi->index)
 225                         break;
 226                 if ((rtm->rtm_flags & RTF_UP) == 0) {
 227                         errmsg = "interface down";
 228                         goto die;
 229                 }
 230
 231                 linkstat =
 232                     LINK_STATE_IS_UP(ifm->ifm_data.ifi_link_state) ? 1 : 0;
 233                 if (linkstat != ifi->linkstat) {
 234                         debug("link state %s -> %s",
 235                             ifi->linkstat ? "up" : "down",
 236                             linkstat ? "up" : "down");
 237                         ifi->linkstat = interface_link_status(ifi->name);
 238                         if (ifi->linkstat) {
 239                                 client->state = S_INIT;
 240                                 state_reboot();
 241                         }
 242                 }
 243                 break;
 244         case RTM_IFANNOUNCE:
 245                 ifan = (struct if_announcemsghdr *)rtm;
 246                 if (ifan->ifan_what == IFAN_DEPARTURE &&
 247                     ifan->ifan_index == ifi->index) {
 248                         errmsg = "interface departure";
 249                         goto die;
 250                 }
 251                 break;
 252         default:
 253                 break;
 254         }
 255         return;
 256
 257 die:
 258         script_init("FAIL", NULL);
 259         if (client->alias)
 260                 script_write_params("alias_", client->alias);
 261         script_go();
 262         error("routehandler: %s", errmsg);
 263 }
 264
 265 int
 266 main(int argc, char *argv[])
 267 {
 268         int      ch, fd, quiet = 0, i = 0, pipe_fd[2];
 269         struct passwd *pw;
 270
 271         /* Initially, log errors to stderr as well as to syslogd. */
 272         openlog(getprogname(), LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY);
 273         setlogmask(LOG_UPTO(LOG_INFO));
 274
 275         while ((ch = getopt(argc, argv, "c:dl:qu")) != -1)
 276                 switch (ch) {
 277                 case 'c':
 278                         path_dhclient_conf = optarg;
 279                         break;
 280                 case 'd':
 281                         no_daemon = 1;
 282                         break;
 283                 case 'l':
 284                         path_dhclient_db = optarg;
 285                         break;
 286                 case 'q':
 287                         quiet = 1;
 288                         break;
 289                 case 'u':
 290                         unknown_ok = 0;
 291                         break;
 292                 default:
 293                         usage();
 294                 }
 295
 296         argc -= optind;
 297         argv += optind;
 298
 299         if (argc != 1)
 300                 usage();
 301
 302         ifi = calloc(1, sizeof(*ifi));
 303         if (ifi == NULL)
 304                 error("ifi calloc");
 305         client = calloc(1, sizeof(*client));
 306         if (client == NULL)
 307                 error("client calloc");
 308         config = calloc(1, sizeof(*config));
 309         if (config == NULL)
 310                 error("config calloc");
 311
 312         if (strlcpy(ifi->name, argv[0], IFNAMSIZ) >= IFNAMSIZ)
 313                 error("Interface name too long");
 314         if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s",
 315             _PATH_DHCLIENT_DB, ifi->name) == -1)
 316                 error("asprintf");
 317
 318         if (quiet)
 319                 log_perror = 0;
 320
 321         tzset();
 322         time(&cur_time);
 323
 324         memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast));
 325         sockaddr_broadcast.sin_family = AF_INET;
 326         sockaddr_broadcast.sin_port = htons(REMOTE_PORT);
 327         sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST;
 328         sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast);
 329         inaddr_any.s_addr = INADDR_ANY;
 330
 331         read_client_conf();
 332
 333         if (interface_status(ifi->name) == 0) {
 334                 interface_link_forceup(ifi->name);
 335                 /* Give it up to 4 seconds of silent grace to find link */
 336                 i = -4;
 337         } else
 338                 i = 0;
 339
 340         while (!(ifi->linkstat = interface_link_status(ifi->name))) {
 341                 if (i == 0)
 342                         fprintf(stderr, "%s: no link ...", ifi->name);
 343                 else if (i > 0)
 344                         fprintf(stderr, ".");
 345                 fflush(stderr);
 346                 if (++i > config->link_timeout) {
 347                         fprintf(stderr, " sleeping\n");
 348                         goto dispatch;
 349                 }
 350                 sleep(1);
 351         }
 352         if (i > 0)
 353                 fprintf(stderr, " got link\n");
 354
 355  dispatch:
 356         if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
 357                 error("cannot open %s: %m", _PATH_DEVNULL);
 358
 359         if ((pw = getpwnam("_dhcp")) == NULL)
 360                 error("no such user: _dhcp");
 361
 362         if (pipe(pipe_fd) == -1)
 363                 error("pipe");
 364
 365         fork_privchld(pipe_fd[0], pipe_fd[1]);
 366
 367         close(pipe_fd[0]);
 368         privfd = pipe_fd[1];
 369
 370         if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1)
 371                 error("can't open and lock %s: %m", path_dhclient_db);
 372         read_client_leases();
 373         if ((leaseFile = fopen(path_dhclient_db, "w")) == NULL)
 374                 error("can't open %s: %m", path_dhclient_db);
 375         rewrite_client_leases();
 376         close(fd);
 377
 378         priv_script_init("PREINIT", NULL);
 379         if (client->alias)
 380                 priv_script_write_params("alias_", client->alias);
 381         priv_script_go();
 382
 383         if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
 384                 error("socket(PF_ROUTE, SOCK_RAW): %m");
 385
 386         /* set up the interface */
 387         discover_interface();
 388
 389         if (chroot(_PATH_VAREMPTY) == -1)
 390                 error("chroot");
 391         if (chdir("/") == -1)
 392                 error("chdir(\"/\")");
 393
 394         if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1)
 395                 error("setresgid");
 396         if (setgroups(1, &pw->pw_gid) == -1)
 397                 error("setgroups");
 398         if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
 399                 error("setresuid");
 400
 401         endpwent();
 402
 403         setproctitle("%s", ifi->name);
 404
 405         if (ifi->linkstat) {
 406                 client->state = S_INIT;
 407                 state_reboot();
 408         } else
 409                 go_daemon();
 410
 411         dispatch();
 412
 413         /* not reached */
 414         return (0);
 415 }
 416
 417 void
 418 usage(void)
 419 {
 420         fprintf(stderr, "usage: %s [-dqu] [-c file] [-l file] interface\n",
 421             getprogname());
 422         exit(1);
 423 }
 424
 425 /*
 426  * Individual States:
 427  *
 428  * Each routine is called from the dhclient_state_machine() in one of
 429  * these conditions:
 430  * -> entering INIT state
 431  * -> recvpacket_flag == 0: timeout in this state
 432  * -> otherwise: received a packet in this state
 433  *
 434  * Return conditions as handled by dhclient_state_machine():
 435  * Returns 1, sendpacket_flag = 1: send packet, reset timer.
 436  * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone).
 437  * Returns 0: finish the nap which was interrupted for no good reason.
 438  *
 439  * Several per-interface variables are used to keep track of the process:
 440  *   active_lease: the lease that is being used on the interface
 441  *                 (null pointer if not configured yet).
 442  *   offered_leases: leases corresponding to DHCPOFFER messages that have
 443  *                   been sent to us by DHCP servers.
 444  *   acked_leases: leases corresponding to DHCPACK messages that have been
 445  *                 sent to us by DHCP servers.
 446  *   sendpacket: DHCP packet we're trying to send.
 447  *   destination: IP address to send sendpacket to
 448  * In addition, there are several relevant per-lease variables.
 449  *   T1_expiry, T2_expiry, lease_expiry: lease milestones
 450  * In the active lease, these control the process of renewing the lease;
 451  * In leases on the acked_leases list, this simply determines when we
 452  * can no longer legitimately use the lease.
 453  */
 454 void
 455 state_reboot(void)
 456 {
 457         /* If we don't remember an active lease, go straight to INIT. */
 458         if (!client->active || client->active->is_bootp) {
 459                 state_init();
 460                 return;
 461         }
 462
 463         /* We are in the rebooting state. */
 464         client->state = S_REBOOTING;
 465
 466         /* make_request doesn't initialize xid because it normally comes
 467            from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER,
 468            so pick an xid now. */
 469         client->xid = arc4random();
 470
 471         /* Make a DHCPREQUEST packet, and set appropriate per-interface
 472            flags. */
 473         make_request(client->active);
 474         client->destination = iaddr_broadcast;
 475         client->first_sending = cur_time;
 476         client->interval = config->initial_interval;
 477
 478         /* Zap the medium list... */
 479         client->medium = NULL;
 480
 481         /* Send out the first DHCPREQUEST packet. */
 482         send_request();
 483 }
 484
 485 /*
 486  * Called when a lease has completely expired and we've
 487  * been unable to renew it.
 488  */
 489 void
 490 state_init(void)
 491 {
 492         /* Make a DHCPDISCOVER packet, and set appropriate per-interface
 493            flags. */
 494         make_discover(client->active);
 495         client->xid = client->packet.xid;
 496         client->destination = iaddr_broadcast;
 497         client->state = S_SELECTING;
 498         client->first_sending = cur_time;
 499         client->interval = config->initial_interval;
 500
 501         /* Add an immediate timeout to cause the first DHCPDISCOVER packet
 502            to go out. */
 503         send_discover();
 504 }
 505
 506 /*
 507  * state_selecting is called when one or more DHCPOFFER packets
 508  * have been received and a configurable period of time has passed.
 509  */
 510 void
 511 state_selecting(void)
 512 {
 513         struct client_lease *lp, *next, *picked;
 514
 515         /* Cancel state_selecting and send_discover timeouts, since either
 516            one could have got us here. */
 517         cancel_timeout(state_selecting);
 518         cancel_timeout(send_discover);
 519
 520         /* We have received one or more DHCPOFFER packets.   Currently,
 521            the only criterion by which we judge leases is whether or
 522            not we get a response when we arp for them. */
 523         picked = NULL;
 524         for (lp = client->offered_leases; lp; lp = next) {
 525                 next = lp->next;
 526
 527                 /* Check to see if we got an ARPREPLY for the address
 528                    in this particular lease. */
 529                 if (!picked) {
 530                         script_init("ARPCHECK", lp->medium);
 531                         script_write_params("check_", lp);
 532
 533                         /* If the ARPCHECK code detects another
 534                            machine using the offered address, it exits
 535                            nonzero.  We need to send a DHCPDECLINE and
 536                            toss the lease. */
 537                         if (script_go()) {
 538                                 make_decline(lp);
 539                                 send_decline();
 540                                 goto freeit;
 541                         }
 542                         picked = lp;
 543                         picked->next = NULL;
 544                 } else {
 545 freeit:
 546                         free_client_lease(lp);
 547                 }
 548         }
 549         client->offered_leases = NULL;
 550
 551         /* If we just tossed all the leases we were offered, go back
 552            to square one. */
 553         if (!picked) {
 554                 client->state = S_INIT;
 555                 state_init();
 556                 return;
 557         }
 558
 559         /* If it was a BOOTREPLY, we can just take the address right now. */
 560         if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
 561                 client->new = picked;
 562
 563                 /* Make up some lease expiry times
 564                    XXX these should be configurable. */
 565                 client->new->expiry = cur_time + 12000;
 566                 client->new->renewal += cur_time + 8000;
 567                 client->new->rebind += cur_time + 10000;
 568
 569                 client->state = S_REQUESTING;
 570
 571                 /* Bind to the address we received. */
 572                 bind_lease();
 573                 return;
 574         }
 575
 576         /* Go to the REQUESTING state. */
 577         client->destination = iaddr_broadcast;
 578         client->state = S_REQUESTING;
 579         client->first_sending = cur_time;
 580         client->interval = config->initial_interval;
 581
 582         /* Make a DHCPREQUEST packet from the lease we picked. */
 583         make_request(picked);
 584         client->xid = client->packet.xid;
 585
 586         /* Toss the lease we picked - we'll get it back in a DHCPACK. */
 587         free_client_lease(picked);
 588
 589         /* Add an immediate timeout to send the first DHCPREQUEST packet. */
 590         send_request();
 591 }
 592
 593 void
 594 dhcpack(struct iaddr client_addr, struct option_data *options)
 595 {
 596         struct client_lease *lease;
 597
 598
 599         if (client->state != S_REBOOTING &&
 600             client->state != S_REQUESTING &&
 601             client->state != S_RENEWING &&
 602             client->state != S_REBINDING)
 603                 return;
 604
 605
 606         lease = packet_to_lease(options);
 607         if (!lease) {
 608                 note("packet_to_lease failed.");
 609                 return;
 610         }
 611
 612         client->new = lease;
 613
 614         /* Stop resending DHCPREQUEST. */
 615         cancel_timeout(send_request);
 616
 617         /* Figure out the lease time. */
 618         if (client->new->options[DHO_DHCP_LEASE_TIME].data)
 619                 client->new->expiry =
 620                     getULong(client->new->options[DHO_DHCP_LEASE_TIME].data);
 621         else
 622                 client->new->expiry = DEFAULT_LEASE_TIME;
 623         /* A number that looks negative here is really just very large,
 624            because the lease expiry offset is unsigned. */
 625         if (client->new->expiry < 0)
 626                 client->new->expiry = TIME_MAX;
 627         /* XXX should be fixed by resetting the client state */
 628         if (client->new->expiry < 60)
 629                 client->new->expiry = 60;
 630
 631         /* Take the server-provided renewal time if there is one;
 632            otherwise figure it out according to the spec. */
 633         if (client->new->options[DHO_DHCP_RENEWAL_TIME].len)
 634                 client->new->renewal =
 635                     getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data);
 636         else
 637                 client->new->renewal = client->new->expiry / 2;
 638
 639         /* Same deal with the rebind time. */
 640         if (client->new->options[DHO_DHCP_REBINDING_TIME].len)
 641                 client->new->rebind =
 642                     getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data);
 643         else
 644                 client->new->rebind = client->new->renewal +
 645                     client->new->renewal / 2 + client->new->renewal / 4;
 646
 647         client->new->expiry += cur_time;
 648         /* Lease lengths can never be negative. */
 649         if (client->new->expiry < cur_time)
 650                 client->new->expiry = TIME_MAX;
 651         client->new->renewal += cur_time;
 652         if (client->new->renewal < cur_time)
 653                 client->new->renewal = TIME_MAX;
 654         client->new->rebind += cur_time;
 655         if (client->new->rebind < cur_time)
 656                 client->new->rebind = TIME_MAX;
 657
 658         bind_lease();
 659 }
 660
 661 void
 662 bind_lease(void)
 663 {
 664         /* Remember the medium. */
 665         client->new->medium = client->medium;
 666
 667         /* Write out the new lease. */
 668         write_client_lease(client->new, 0);
 669
 670         /* Run the client script with the new parameters. */
 671         script_init((client->state == S_REQUESTING ? "BOUND" :
 672             (client->state == S_RENEWING ? "RENEW" :
 673             (client->state == S_REBOOTING ? "REBOOT" : "REBIND"))),
 674             client->new->medium);
 675         if (client->active && client->state != S_REBOOTING)
 676                 script_write_params("old_", client->active);
 677         script_write_params("new_", client->new);
 678         if (client->alias)
 679                 script_write_params("alias_", client->alias);
 680         script_go();
 681
 682         /* Replace the old active lease with the new one. */
 683         if (client->active)
 684                 free_client_lease(client->active);
 685         client->active = client->new;
 686         client->new = NULL;
 687
 688         /* Set up a timeout to start the renewal process. */
 689         add_timeout(client->active->renewal, state_bound);
 690
 691         note("bound to %s -- renewal in %ld seconds.",
 692             piaddr(client->active->address),
 693             client->active->renewal - cur_time);
 694         client->state = S_BOUND;
 695         reinitialize_interface();
 696         go_daemon();
 697 }
 698
 699 /*
 700  * state_bound is called when we've successfully bound to a particular
 701  * lease, but the renewal time on that lease has expired.   We are
 702  * expected to unicast a DHCPREQUEST to the server that gave us our
 703  * original lease.
 704  */
 705 void
 706 state_bound(void)
 707 {
 708         /* T1 has expired. */
 709         make_request(client->active);
 710         client->xid = client->packet.xid;
 711
 712         if (client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) {
 713                 memcpy(client->destination.iabuf,
 714                     client->active->options[DHO_DHCP_SERVER_IDENTIFIER].data,
 715                     4);
 716                 client->destination.len = 4;
 717         } else
 718                 client->destination = iaddr_broadcast;
 719
 720         client->first_sending = cur_time;
 721         client->interval = config->initial_interval;
 722         client->state = S_RENEWING;
 723
 724         /* Send the first packet immediately. */
 725         send_request();
 726 }
 727
 728 void
 729 dhcpoffer(struct iaddr client_addr, struct option_data *options)
 730 {
 731         struct client_lease *lease, *lp;
 732         int i;
 733         int arp_timeout_needed, stop_selecting;
 734         char *name = options[DHO_DHCP_MESSAGE_TYPE].len ? "DHCPOFFER" :
 735             "BOOTREPLY";
 736
 737
 738         if (client->state != S_SELECTING)
 739                 return;
 740
 741
 742         /* If this lease doesn't supply the minimum required parameters,
 743            blow it off. */
 744         for (i = 0; config->required_options[i]; i++) {
 745                 if (!options[config->required_options[i]].len) {
 746                         note("%s isn't satisfactory.", name);
 747                         return;
 748                 }
 749         }
 750
 751         /* If we've already seen this lease, don't record it again. */
 752         for (lease = client->offered_leases;
 753             lease; lease = lease->next) {
 754                 if (lease->address.len == sizeof(client->packet.yiaddr) &&
 755                     !memcmp(lease->address.iabuf,
 756                     &client->packet.yiaddr, lease->address.len)) {
 757                         debug("%s already seen.", name);
 758                         return;
 759                 }
 760         }
 761
 762         lease = packet_to_lease(options);
 763         if (!lease) {
 764                 note("packet_to_lease failed.");
 765                 return;
 766         }
 767
 768         /* If this lease was acquired through a BOOTREPLY, record that
 769            fact. */
 770         if (!options[DHO_DHCP_MESSAGE_TYPE].len)
 771                 lease->is_bootp = 1;
 772
 773         /* Record the medium under which this lease was offered. */
 774         lease->medium = client->medium;
 775
 776         /* Send out an ARP Request for the offered IP address. */
 777         script_init("ARPSEND", lease->medium);
 778         script_write_params("check_", lease);
 779         /* If the script can't send an ARP request without waiting,
 780            we'll be waiting when we do the ARPCHECK, so don't wait now. */
 781         if (script_go())
 782                 arp_timeout_needed = 0;
 783         else
 784                 arp_timeout_needed = 2;
 785
 786         /* Figure out when we're supposed to stop selecting. */
 787         stop_selecting = client->first_sending + config->select_interval;
 788
 789         /* If this is the lease we asked for, put it at the head of the
 790            list, and don't mess with the arp request timeout. */
 791         if (lease->address.len == client->requested_address.len &&
 792             !memcmp(lease->address.iabuf,
 793             client->requested_address.iabuf,
 794             client->requested_address.len)) {
 795                 lease->next = client->offered_leases;
 796                 client->offered_leases = lease;
 797         } else {
 798                 /* If we already have an offer, and arping for this
 799                    offer would take us past the selection timeout,
 800                    then don't extend the timeout - just hope for the
 801                    best. */
 802                 if (client->offered_leases &&
 803                     (cur_time + arp_timeout_needed) > stop_selecting)
 804                         arp_timeout_needed = 0;
 805
 806                 /* Put the lease at the end of the list. */
 807                 lease->next = NULL;
 808                 if (!client->offered_leases)
 809                         client->offered_leases = lease;
 810                 else {
 811                         for (lp = client->offered_leases; lp->next;
 812                             lp = lp->next)
 813                                 ;       /* nothing */
 814                         lp->next = lease;
 815                 }
 816         }
 817
 818         /* If we're supposed to stop selecting before we've had time
 819            to wait for the ARPREPLY, add some delay to wait for
 820            the ARPREPLY. */
 821         if (stop_selecting - cur_time < arp_timeout_needed)
 822                 stop_selecting = cur_time + arp_timeout_needed;
 823
 824         /* If the selecting interval has expired, go immediately to
 825            state_selecting().  Otherwise, time out into
 826            state_selecting at the select interval. */
 827         if (stop_selecting <= 0)
 828                 state_selecting();
 829         else {
 830                 add_timeout(stop_selecting, state_selecting);
 831                 cancel_timeout(send_discover);
 832         }
 833 }
 834
 835 /*
 836  * Allocate a client_lease structure and initialize it from the
 837  * parameters in the specified packet.
 838  */
 839 struct client_lease *
 840 packet_to_lease(struct option_data *options)
 841 {
 842         struct client_lease *lease;
 843         int i;
 844
 845         lease = malloc(sizeof(struct client_lease));
 846
 847         if (!lease) {
 848                 warning("dhcpoffer: no memory to record lease.");
 849                 return (NULL);
 850         }
 851
 852         memset(lease, 0, sizeof(*lease));
 853
 854         /* Copy the lease options. */
 855         for (i = 0; i < 256; i++) {
 856                 if (options[i].len) {
 857                         lease->options[i] = options[i];
 858                         options[i].data = NULL;
 859                         options[i].len = 0;
 860                         if (!check_option(lease, i)) {
 861                                 warning("Invalid lease option - ignoring offer");
 862                                 free_client_lease(lease);
 863                                 return (NULL);
 864                         }
 865                 }
 866         }
 867
 868         lease->address.len = sizeof(client->packet.yiaddr);
 869         memcpy(lease->address.iabuf, &client->packet.yiaddr,
 870             lease->address.len);
 871
 872         /* If the server name was filled out, copy it. */
 873         if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
 874             !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
 875             client->packet.sname[0]) {
 876                 lease->server_name = malloc(DHCP_SNAME_LEN + 1);
 877                 if (!lease->server_name) {
 878                         warning("dhcpoffer: no memory for server name.");
 879                         free_client_lease(lease);
 880                         return (NULL);
 881                 }
 882                 memcpy(lease->server_name, client->packet.sname,
 883                     DHCP_SNAME_LEN);
 884                 lease->server_name[DHCP_SNAME_LEN] = '\0';
 885                 if (!res_hnok(lease->server_name)) {
 886                         warning("Bogus server name %s", lease->server_name);
 887                         free(lease->server_name);
 888                         lease->server_name = NULL;
 889                 }
 890         }
 891
 892         /* Ditto for the filename. */
 893         if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
 894             !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
 895             client->packet.file[0]) {
 896                 /* Don't count on the NUL terminator. */
 897                 lease->filename = malloc(DHCP_FILE_LEN + 1);
 898                 if (!lease->filename) {
 899                         warning("dhcpoffer: no memory for filename.");
 900                         free_client_lease(lease);
 901                         return (NULL);
 902                 }
 903                 memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN);
 904                 lease->filename[DHCP_FILE_LEN] = '\0';
 905         }
 906         return lease;
 907 }
 908
 909 void
 910 dhcpnak(struct iaddr client_addr, struct option_data *options)
 911 {
 912
 913         if (client->state != S_REBOOTING &&
 914             client->state != S_REQUESTING &&
 915             client->state != S_RENEWING &&
 916             client->state != S_REBINDING)
 917                 return;
 918
 919
 920         if (!client->active) {
 921                 note("DHCPNAK with no active lease.");
 922                 return;
 923         }
 924
 925         free_client_lease(client->active);
 926         client->active = NULL;
 927
 928         /* Stop sending DHCPREQUEST packets... */
 929         cancel_timeout(send_request);
 930
 931         client->state = S_INIT;
 932         state_init();
 933 }
 934
 935 /*
 936  * Send out a DHCPDISCOVER packet, and set a timeout to send out another
 937  * one after the right interval has expired.  If we don't get an offer by
 938  * the time we reach the panic interval, call the panic function.
 939  */
 940 void
 941 send_discover(void)
 942 {
 943         int interval, increase = 1;
 944
 945         /* Figure out how long it's been since we started transmitting. */
 946         interval = cur_time - client->first_sending;
 947
 948         /* If we're past the panic timeout, call the script and tell it
 949            we haven't found anything for this interface yet. */
 950         if (interval > config->timeout) {
 951                 state_panic();
 952                 return;
 953         }
 954
 955         /* If we're selecting media, try the whole list before doing
 956            the exponential backoff, but if we've already received an
 957            offer, stop looping, because we obviously have it right. */
 958         if (!client->offered_leases && config->media) {
 959                 int fail = 0;
 960 again:
 961                 if (client->medium) {
 962                         client->medium = client->medium->next;
 963                         increase = 0;
 964                 }
 965                 if (!client->medium) {
 966                         if (fail)
 967                                 error("No valid media types for %s!", ifi->name);
 968                         client->medium = config->media;
 969                         increase = 1;
 970                 }
 971
 972                 note("Trying medium \"%s\" %d", client->medium->string,
 973                     increase);
 974                 script_init("MEDIUM", client->medium);
 975                 if (script_go())
 976                         goto again;
 977         }
 978
 979         /*
 980          * If we're supposed to increase the interval, do so.  If it's
 981          * currently zero (i.e., we haven't sent any packets yet), set
 982          * it to initial_interval; otherwise, add to it a random
 983          * number between zero and two times itself.  On average, this
 984          * means that it will double with every transmission.
 985          */
 986         if (increase) {
 987                 if (!client->interval)
 988                         client->interval = config->initial_interval;
 989                 else {
 990                         client->interval += (arc4random() >> 2) %
 991                             (2 * client->interval);
 992                 }
 993
 994                 /* Don't backoff past cutoff. */
 995                 if (client->interval > config->backoff_cutoff)
 996                         client->interval = ((config->backoff_cutoff / 2)
 997                                  + ((arc4random() >> 2) %
 998                                     config->backoff_cutoff));
 999         } else if (!client->interval)
1000                 client->interval = config->initial_interval;
1001
1002         /* If the backoff would take us to the panic timeout, just use that
1003            as the interval. */
1004         if (cur_time + client->interval >
1005             client->first_sending + config->timeout)
1006                 client->interval = (client->first_sending +
1007                          config->timeout) - cur_time + 1;
1008
1009         /* Record the number of seconds since we started sending. */
1010         if (interval < 65536)
1011                 client->packet.secs = htons(interval);
1012         else
1013                 client->packet.secs = htons(65535);
1014         client->secs = client->packet.secs;
1015
1016         note("DHCPDISCOVER on %s to %s port %d interval %ld",
1017             ifi->name, inet_ntoa(sockaddr_broadcast.sin_addr),
1018             ntohs(sockaddr_broadcast.sin_port), client->interval);
1019
1020         /* Send out a packet. */
1021         send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1022
1023         add_timeout(cur_time + client->interval, send_discover);
1024 }
1025
1026 /*
1027  * state_panic gets called if we haven't received any offers in a preset
1028  * amount of time.   When this happens, we try to use existing leases
1029  * that haven't yet expired, and failing that, we call the client script
1030  * and hope it can do something.
1031  */
1032 void
1033 state_panic(void)
1034 {
1035         struct client_lease *loop = client->active;
1036         struct client_lease *lp;
1037
1038         note("No DHCPOFFERS received.");
1039
1040         /* We may not have an active lease, but we may have some
1041            predefined leases that we can try. */
1042         if (!client->active && client->leases)
1043                 goto activate_next;
1044
1045         /* Run through the list of leases and see if one can be used. */
1046         while (client->active) {
1047                 if (client->active->expiry > cur_time) {
1048                         note("Trying recorded lease %s",
1049                             piaddr(client->active->address));
1050                         /* Run the client script with the existing
1051                            parameters. */
1052                         script_init("TIMEOUT",
1053                             client->active->medium);
1054                         script_write_params("new_", client->active);
1055                         if (client->alias)
1056                                 script_write_params("alias_",
1057                                     client->alias);
1058
1059                         /* If the old lease is still good and doesn't
1060                            yet need renewal, go into BOUND state and
1061                            timeout at the renewal time. */
1062                         if (!script_go()) {
1063                                 if (cur_time <
1064                                     client->active->renewal) {
1065                                         client->state = S_BOUND;
1066                                         note("bound: renewal in %ld seconds.",
1067                                             client->active->renewal -
1068                                             cur_time);
1069                                         add_timeout(client->active->renewal,
1070                                             state_bound);
1071                                 } else {
1072                                         client->state = S_BOUND;
1073                                         note("bound: immediate renewal.");
1074                                         state_bound();
1075                                 }
1076                                 reinitialize_interface();
1077                                 go_daemon();
1078                                 return;
1079                         }
1080                 }
1081
1082                 /* If there are no other leases, give up. */
1083                 if (!client->leases) {
1084                         client->leases = client->active;
1085                         client->active = NULL;
1086                         break;
1087                 }
1088
1089 activate_next:
1090                 /* Otherwise, put the active lease at the end of the
1091                    lease list, and try another lease.. */
1092                 for (lp = client->leases; lp->next; lp = lp->next)
1093                         ;
1094                 lp->next = client->active;
1095                 if (lp->next)
1096                         lp->next->next = NULL;
1097                 client->active = client->leases;
1098                 client->leases = client->leases->next;
1099
1100                 /* If we already tried this lease, we've exhausted the
1101                    set of leases, so we might as well give up for
1102                    now. */
1103                 if (client->active == loop)
1104                         break;
1105                 else if (!loop)
1106                         loop = client->active;
1107         }
1108
1109         /* No leases were available, or what was available didn't work, so
1110            tell the shell script that we failed to allocate an address,
1111            and try again later. */
1112         note("No working leases in persistent database - sleeping.");
1113         script_init("FAIL", NULL);
1114         if (client->alias)
1115                 script_write_params("alias_", client->alias);
1116         script_go();
1117         client->state = S_INIT;
1118         add_timeout(cur_time + config->retry_interval, state_init);
1119         go_daemon();
1120 }
1121
1122 void
1123 send_request(void)
1124 {
1125         struct sockaddr_in destination;
1126         struct in_addr from;
1127         int interval;
1128
1129         /* Figure out how long it's been since we started transmitting. */
1130         interval = cur_time - client->first_sending;
1131
1132         /* If we're in the INIT-REBOOT or REQUESTING state and we're
1133            past the reboot timeout, go to INIT and see if we can
1134            DISCOVER an address... */
1135         /* XXX In the INIT-REBOOT state, if we don't get an ACK, it
1136            means either that we're on a network with no DHCP server,
1137            or that our server is down.  In the latter case, assuming
1138            that there is a backup DHCP server, DHCPDISCOVER will get
1139            us a new address, but we could also have successfully
1140            reused our old address.  In the former case, we're hosed
1141            anyway.  This is not a win-prone situation. */
1142         if ((client->state == S_REBOOTING ||
1143             client->state == S_REQUESTING) &&
1144             interval > config->reboot_timeout) {
1145 cancel:
1146                 client->state = S_INIT;
1147                 cancel_timeout(send_request);
1148                 state_init();
1149                 return;
1150         }
1151
1152         /* If we're in the reboot state, make sure the media is set up
1153            correctly. */
1154         if (client->state == S_REBOOTING &&
1155             !client->medium &&
1156             client->active->medium) {
1157                 script_init("MEDIUM", client->active->medium);
1158
1159                 /* If the medium we chose won't fly, go to INIT state. */
1160                 if (script_go())
1161                         goto cancel;
1162
1163                 /* Record the medium. */
1164                 client->medium = client->active->medium;
1165         }
1166
1167         /* If the lease has expired, relinquish the address and go back
1168            to the INIT state. */
1169         if (client->state != S_REQUESTING &&
1170             cur_time > client->active->expiry) {
1171                 /* Run the client script with the new parameters. */
1172                 script_init("EXPIRE", NULL);
1173                 script_write_params("old_", client->active);
1174                 if (client->alias)
1175                         script_write_params("alias_", client->alias);
1176                 script_go();
1177
1178                 /* Now do a preinit on the interface so that we can
1179                    discover a new address. */
1180                 script_init("PREINIT", NULL);
1181                 if (client->alias)
1182                         script_write_params("alias_", client->alias);
1183                 script_go();
1184
1185                 client->state = S_INIT;
1186                 state_init();
1187                 return;
1188         }
1189
1190         /* Do the exponential backoff... */
1191         if (!client->interval)
1192                 client->interval = config->initial_interval;
1193         else
1194                 client->interval += ((arc4random() >> 2) %
1195                     (2 * client->interval));
1196
1197         /* Don't backoff past cutoff. */
1198         if (client->interval > config->backoff_cutoff)
1199                 client->interval = ((config->backoff_cutoff / 2) +
1200                     ((arc4random() >> 2) % client->interval));
1201
1202         /* If the backoff would take us to the expiry time, just set the
1203            timeout to the expiry time. */
1204         if (client->state != S_REQUESTING && cur_time + client->interval >
1205             client->active->expiry)
1206                 client->interval = client->active->expiry - cur_time + 1;
1207
1208         /* If the lease T2 time has elapsed, or if we're not yet bound,
1209            broadcast the DHCPREQUEST rather than unicasting. */
1210         memset(&destination, 0, sizeof(destination));
1211         if (client->state == S_REQUESTING ||
1212             client->state == S_REBOOTING ||
1213             cur_time > client->active->rebind)
1214                 destination.sin_addr.s_addr = INADDR_BROADCAST;
1215         else
1216                 memcpy(&destination.sin_addr.s_addr, client->destination.iabuf,
1217                     sizeof(destination.sin_addr.s_addr));
1218         destination.sin_port = htons(REMOTE_PORT);
1219         destination.sin_family = AF_INET;
1220         destination.sin_len = sizeof(destination);
1221
1222         if (client->state != S_REQUESTING)
1223                 memcpy(&from, client->active->address.iabuf, sizeof(from));
1224         else
1225                 from.s_addr = INADDR_ANY;
1226
1227         /* Record the number of seconds since we started sending. */
1228         if (client->state == S_REQUESTING)
1229                 client->packet.secs = client->secs;
1230         else {
1231                 if (interval < 65536)
1232                         client->packet.secs = htons(interval);
1233                 else
1234                         client->packet.secs = htons(65535);
1235         }
1236
1237         note("DHCPREQUEST on %s to %s port %d", ifi->name,
1238             inet_ntoa(destination.sin_addr), ntohs(destination.sin_port));
1239
1240         /* Send out a packet. */
1241         send_packet(from, &destination, NULL);
1242
1243         add_timeout(cur_time + client->interval, send_request);
1244 }
1245
1246 void
1247 send_decline(void)
1248 {
1249         note("DHCPDECLINE on %s to %s port %d", ifi->name,
1250             inet_ntoa(sockaddr_broadcast.sin_addr),
1251             ntohs(sockaddr_broadcast.sin_port));
1252
1253         /* Send out a packet. */
1254         send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1255 }
1256
1257 void
1258 make_discover(struct client_lease *lease)
1259 {
1260         unsigned char discover = DHCPDISCOVER;
1261         struct option_data options[256];
1262         int i;
1263
1264         memset(options, 0, sizeof(options));
1265         memset(&client->packet, 0, sizeof(client->packet));
1266
1267         /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */
1268         i = DHO_DHCP_MESSAGE_TYPE;
1269         options[i].data = &discover;
1270         options[i].len = sizeof(discover);
1271
1272         /* Request the options we want */
1273         i  = DHO_DHCP_PARAMETER_REQUEST_LIST;
1274         options[i].data = config->requested_options;
1275         options[i].len = config->requested_option_count;
1276
1277         /* If we had an address, try to get it again. */
1278         if (lease) {
1279                 client->requested_address = lease->address;
1280                 i = DHO_DHCP_REQUESTED_ADDRESS;
1281                 options[i].data = lease->address.iabuf;
1282                 options[i].len = lease->address.len;
1283         } else
1284                 client->requested_address.len = 0;
1285
1286         /* Send any options requested in the config file. */
1287         for (i = 0; i < 256; i++)
1288                 if (!options[i].data &&
1289                     config->send_options[i].data) {
1290                         options[i].data = config->send_options[i].data;
1291                         options[i].len = config->send_options[i].len;
1292                 }
1293
1294         /* Set up the option buffer to fit in a minimal UDP packet. */
1295         i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1296             options);
1297         if (i == -1 || client->packet.options[i] != DHO_END)
1298                 error("options do not fit in DHCPDISCOVER packet.");
1299         client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1300         if (client->packet_length < BOOTP_MIN_LEN)
1301                 client->packet_length = BOOTP_MIN_LEN;
1302
1303         client->packet.op = BOOTREQUEST;
1304         client->packet.htype = ifi->hw_address.htype;
1305         client->packet.hlen = ifi->hw_address.hlen;
1306         client->packet.hops = 0;
1307         client->packet.xid = arc4random();
1308         client->packet.secs = 0; /* filled in by send_discover. */
1309         client->packet.flags = 0;
1310
1311         memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1312         memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1313         memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1314         memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1315         memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1316             ifi->hw_address.hlen);
1317 }
1318
1319 void
1320 make_request(struct client_lease * lease)
1321 {
1322         unsigned char request = DHCPREQUEST;
1323         struct option_data options[256];
1324         int i;
1325
1326         memset(options, 0, sizeof(options));
1327         memset(&client->packet, 0, sizeof(client->packet));
1328
1329         /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */
1330         i = DHO_DHCP_MESSAGE_TYPE;
1331         options[i].data = &request;
1332         options[i].len = sizeof(request);
1333
1334         /* Request the options we want */
1335         i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1336         options[i].data = config->requested_options;
1337         options[i].len = config->requested_option_count;
1338
1339         /* If we are requesting an address that hasn't yet been assigned
1340            to us, use the DHCP Requested Address option. */
1341         if (client->state == S_REQUESTING) {
1342                 /* Send back the server identifier... */
1343                 i = DHO_DHCP_SERVER_IDENTIFIER;
1344                 options[i].data = lease->options[i].data;
1345                 options[i].len = lease->options[i].len;
1346         }
1347         if (client->state == S_REQUESTING ||
1348             client->state == S_REBOOTING) {
1349                 client->requested_address = lease->address;
1350                 i = DHO_DHCP_REQUESTED_ADDRESS;
1351                 options[i].data = lease->address.iabuf;
1352                 options[i].len = lease->address.len;
1353         } else
1354                 client->requested_address.len = 0;
1355
1356         /* Send any options requested in the config file. */
1357         for (i = 0; i < 256; i++)
1358                 if (!options[i].data && config->send_options[i].data) {
1359                         options[i].data = config->send_options[i].data;
1360                         options[i].len = config->send_options[i].len;
1361                 }
1362
1363         /* Set up the option buffer to fit in a minimal UDP packet. */
1364         i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1365             options);
1366         if (i == -1 || client->packet.options[i] != DHO_END)
1367                 error("options do not fit in DHCPREQUEST packet.");
1368         client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1369         if (client->packet_length < BOOTP_MIN_LEN)
1370                 client->packet_length = BOOTP_MIN_LEN;
1371
1372         client->packet.op = BOOTREQUEST;
1373         client->packet.htype = ifi->hw_address.htype;
1374         client->packet.hlen = ifi->hw_address.hlen;
1375         client->packet.hops = 0;
1376         client->packet.xid = client->xid;
1377         client->packet.secs = 0; /* Filled in by send_request. */
1378         client->packet.flags = 0;
1379
1380         /* If we own the address we're requesting, put it in ciaddr;
1381            otherwise set ciaddr to zero. */
1382         if (client->state == S_BOUND ||
1383             client->state == S_RENEWING ||
1384             client->state == S_REBINDING) {
1385                 memcpy(&client->packet.ciaddr,
1386                     lease->address.iabuf, lease->address.len);
1387         } else {
1388                 memset(&client->packet.ciaddr, 0,
1389                     sizeof(client->packet.ciaddr));
1390         }
1391
1392         memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1393         memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1394         memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1395         memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1396             ifi->hw_address.hlen);
1397 }
1398
1399 void
1400 make_decline(struct client_lease *lease)
1401 {
1402         struct option_data options[256];
1403         unsigned char decline = DHCPDECLINE;
1404         int i;
1405
1406         memset(options, 0, sizeof(options));
1407         memset(&client->packet, 0, sizeof(client->packet));
1408
1409         /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */
1410         i = DHO_DHCP_MESSAGE_TYPE;
1411         options[i].data = &decline;
1412         options[i].len = sizeof(decline);
1413
1414         /* Send back the server identifier... */
1415         i = DHO_DHCP_SERVER_IDENTIFIER;
1416         options[i].data = lease->options[i].data;
1417         options[i].len = lease->options[i].len;
1418
1419         /* Send back the address we're declining. */
1420         i = DHO_DHCP_REQUESTED_ADDRESS;
1421         options[i].data = lease->address.iabuf;
1422         options[i].len = lease->address.len;
1423
1424         /* Send the uid if the user supplied one. */
1425         i = DHO_DHCP_CLIENT_IDENTIFIER;
1426         if (config->send_options[i].len) {
1427                 options[i].data = config->send_options[i].data;
1428                 options[i].len = config->send_options[i].len;
1429         }
1430
1431         /* Set up the option buffer to fit in a minimal UDP packet. */
1432         i = cons_options(client->packet.options, 576 - DHCP_FIXED_LEN,
1433             options);
1434         if (i == -1 || client->packet.options[i] != DHO_END)
1435                 error("options do not fit in DHCPDECLINE packet.");
1436         client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1437         if (client->packet_length < BOOTP_MIN_LEN)
1438                 client->packet_length = BOOTP_MIN_LEN;
1439
1440         client->packet.op = BOOTREQUEST;
1441         client->packet.htype = ifi->hw_address.htype;
1442         client->packet.hlen = ifi->hw_address.hlen;
1443         client->packet.hops = 0;
1444         client->packet.xid = client->xid;
1445         client->packet.secs = 0; /* Filled in by send_request. */
1446         client->packet.flags = 0;
1447
1448         /* ciaddr must always be zero. */
1449         memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1450         memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1451         memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1452         memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1453         memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1454             ifi->hw_address.hlen);
1455 }
1456
1457 void
1458 free_client_lease(struct client_lease *lease)
1459 {
1460         int i;
1461
1462         if (lease->server_name)
1463                 free(lease->server_name);
1464         if (lease->filename)
1465                 free(lease->filename);
1466         for (i = 0; i < 256; i++) {
1467                 if (lease->options[i].len)
1468                         free(lease->options[i].data);
1469         }
1470         free(lease);
1471 }
1472
1473 void
1474 rewrite_client_leases(void)
1475 {
1476         struct client_lease *lp;
1477
1478         if (!leaseFile) /* XXX */
1479                 error("lease file not open");
1480
1481         fflush(leaseFile);
1482         rewind(leaseFile);
1483
1484         for (lp = client->leases; lp; lp = lp->next)
1485                 write_client_lease(lp, 1);
1486         if (client->active)
1487                 write_client_lease(client->active, 1);
1488
1489         fflush(leaseFile);
1490         ftruncate(fileno(leaseFile), ftello(leaseFile));
1491         fsync(fileno(leaseFile));
1492 }
1493
1494 void
1495 write_client_lease(struct client_lease *lease, int rewrite)
1496 {
1497         static int leases_written;
1498         struct tm *t;
1499         int i;
1500
1501         if (!rewrite) {
1502                 if (leases_written++ > 20) {
1503                         rewrite_client_leases();
1504                         leases_written = 0;
1505                 }
1506         }
1507
1508         /* If the lease came from the config file, we don't need to stash
1509            a copy in the lease database. */
1510         if (lease->is_static)
1511                 return;
1512
1513         if (!leaseFile) /* XXX */
1514                 error("lease file not open");
1515
1516         fprintf(leaseFile, "lease {\n");
1517         if (lease->is_bootp)
1518                 fprintf(leaseFile, "  bootp;\n");
1519         fprintf(leaseFile, "  interface \"%s\";\n", ifi->name);
1520         fprintf(leaseFile, "  fixed-address %s;\n", piaddr(lease->address));
1521         if (lease->filename)
1522                 fprintf(leaseFile, "  filename \"%s\";\n", lease->filename);
1523         if (lease->server_name)
1524                 fprintf(leaseFile, "  server-name \"%s\";\n",
1525                     lease->server_name);
1526         if (lease->medium)
1527                 fprintf(leaseFile, "  medium \"%s\";\n", lease->medium->string);
1528         for (i = 0; i < 256; i++)
1529                 if (lease->options[i].len)
1530                         fprintf(leaseFile, "  option %s %s;\n",
1531                             dhcp_options[i].name,
1532                             pretty_print_option(i, lease->options[i].data,
1533                             lease->options[i].len, 1, 1));
1534
1535         t = gmtime(&lease->renewal);
1536         fprintf(leaseFile, "  renew %d %d/%d/%d %02d:%02d:%02d;\n",
1537             t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1538             t->tm_hour, t->tm_min, t->tm_sec);
1539         t = gmtime(&lease->rebind);
1540         fprintf(leaseFile, "  rebind %d %d/%d/%d %02d:%02d:%02d;\n",
1541             t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1542             t->tm_hour, t->tm_min, t->tm_sec);
1543         t = gmtime(&lease->expiry);
1544         fprintf(leaseFile, "  expire %d %d/%d/%d %02d:%02d:%02d;\n",
1545             t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1546             t->tm_hour, t->tm_min, t->tm_sec);
1547         fprintf(leaseFile, "}\n");
1548         fflush(leaseFile);
1549 }
1550
1551 void
1552 script_init(char *reason, struct string_list *medium)
1553 {
1554         size_t           len, mediumlen = 0;
1555         struct imsg_hdr  hdr;
1556         struct buf      *buf;
1557
1558         if (medium != NULL && medium->string != NULL)
1559                 mediumlen = strlen(medium->string);
1560
1561         hdr.code = IMSG_SCRIPT_INIT;
1562         hdr.len = sizeof(struct imsg_hdr) +
1563             sizeof(size_t) + mediumlen +
1564             sizeof(size_t) + strlen(reason);
1565
1566         buf = buf_open(hdr.len);
1567
1568         buf_add(buf, &hdr, sizeof(hdr));
1569         buf_add(buf, &mediumlen, sizeof(mediumlen));
1570         if (mediumlen > 0)
1571                 buf_add(buf, medium->string, mediumlen);
1572         len = strlen(reason);
1573         buf_add(buf, &len, sizeof(len));
1574         buf_add(buf, reason, len);
1575
1576         buf_close(privfd, buf);
1577 }
1578
1579 void
1580 priv_script_init(char *reason, char *medium)
1581 {
1582         client->scriptEnvsize = 100;
1583         if (client->scriptEnv == NULL)
1584                 client->scriptEnv =
1585                     calloc(client->scriptEnvsize, sizeof(char *));
1586         if (client->scriptEnv == NULL)
1587                 error("script_init: no memory for environment");
1588
1589         client->scriptEnv[0] = strdup(CLIENT_PATH);
1590         if (client->scriptEnv[0] == NULL)
1591                 error("script_init: no memory for environment");
1592
1593         client->scriptEnv[1] = NULL;
1594
1595         script_set_env("", "interface", ifi->name);
1596
1597         if (medium)
1598                 script_set_env("", "medium", medium);
1599
1600         script_set_env("", "reason", reason);
1601 }
1602
1603 void
1604 priv_script_write_params(char *prefix, struct client_lease *lease)
1605 {
1606         u_int8_t dbuf[1500];
1607         int i, len = 0;
1608         char tbuf[128];
1609
1610         script_set_env(prefix, "ip_address", piaddr(lease->address));
1611
1612         if (lease->options[DHO_SUBNET_MASK].len &&
1613             (lease->options[DHO_SUBNET_MASK].len <
1614             sizeof(lease->address.iabuf))) {
1615                 struct iaddr netmask, subnet, broadcast;
1616
1617                 memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data,
1618                     lease->options[DHO_SUBNET_MASK].len);
1619                 netmask.len = lease->options[DHO_SUBNET_MASK].len;
1620
1621                 subnet = subnet_number(lease->address, netmask);
1622                 if (subnet.len) {
1623                         script_set_env(prefix, "network_number",
1624                             piaddr(subnet));
1625                         if (!lease->options[DHO_BROADCAST_ADDRESS].len) {
1626                                 broadcast = broadcast_addr(subnet, netmask);
1627                                 if (broadcast.len)
1628                                         script_set_env(prefix,
1629                                             "broadcast_address",
1630                                             piaddr(broadcast));
1631                         }
1632                 }
1633         }
1634
1635         if (lease->filename)
1636                 script_set_env(prefix, "filename", lease->filename);
1637         if (lease->server_name)
1638                 script_set_env(prefix, "server_name",
1639                     lease->server_name);
1640         for (i = 0; i < 256; i++) {
1641                 u_int8_t *dp = NULL;
1642
1643                 if (config->defaults[i].len) {
1644                         if (lease->options[i].len) {
1645                                 switch (config->default_actions[i]) {
1646                                 case ACTION_DEFAULT:
1647                                         dp = lease->options[i].data;
1648                                         len = lease->options[i].len;
1649                                         break;
1650                                 case ACTION_SUPERSEDE:
1651 supersede:
1652                                         dp = config->defaults[i].data;
1653                                         len = config->defaults[i].len;
1654                                         break;
1655                                 case ACTION_PREPEND:
1656                                         len = config->defaults[i].len +
1657                                             lease->options[i].len;
1658                                         if (len > sizeof(dbuf)) {
1659                                                 warning("no space to %s %s",
1660                                                     "prepend option",
1661                                                     dhcp_options[i].name);
1662                                                 goto supersede;
1663                                         }
1664                                         dp = dbuf;
1665                                         memcpy(dp,
1666                                             config->defaults[i].data,
1667                                             config->defaults[i].len);
1668                                         memcpy(dp +
1669                                             config->defaults[i].len,
1670                                             lease->options[i].data,
1671                                             lease->options[i].len);
1672                                         dp[len] = '\0';
1673                                         break;
1674                                 case ACTION_APPEND:
1675                                         len = config->defaults[i].len +
1676                                             lease->options[i].len;
1677                                         if (len > sizeof(dbuf)) {
1678                                                 warning("no space to %s %s",
1679                                                     "append option",
1680                                                     dhcp_options[i].name);
1681                                                 goto supersede;
1682                                         }
1683                                         dp = dbuf;
1684                                         memcpy(dp, lease->options[i].data,
1685                                             lease->options[i].len);
1686                                         memcpy(dp + lease->options[i].len,
1687                                             config->defaults[i].data,
1688                                             config->defaults[i].len);
1689                                         dp[len] = '\0';
1690                                 }
1691                         } else {
1692                                 dp = config->defaults[i].data;
1693                                 len = config->defaults[i].len;
1694                         }
1695                 } else if (lease->options[i].len) {
1696                         len = lease->options[i].len;
1697                         dp = lease->options[i].data;
1698                 } else {
1699                         len = 0;
1700                 }
1701                 if (len) {
1702                         char name[256];
1703
1704                         if (dhcp_option_ev_name(name, sizeof(name),
1705                             &dhcp_options[i]))
1706                                 script_set_env(prefix, name,
1707                                     pretty_print_option(i, dp, len, 0, 0));
1708                 }
1709         }
1710         snprintf(tbuf, sizeof(tbuf), "%d", (int)lease->expiry);
1711         script_set_env(prefix, "expiry", tbuf);
1712 }
1713
1714 void
1715 script_write_params(char *prefix, struct client_lease *lease)
1716 {
1717         size_t           fn_len = 0, sn_len = 0, pr_len = 0;
1718         struct imsg_hdr  hdr;
1719         struct buf      *buf;
1720         int              i;
1721
1722         if (lease->filename != NULL)
1723                 fn_len = strlen(lease->filename);
1724         if (lease->server_name != NULL)
1725                 sn_len = strlen(lease->server_name);
1726         if (prefix != NULL)
1727                 pr_len = strlen(prefix);
1728
1729         hdr.code = IMSG_SCRIPT_WRITE_PARAMS;
1730         hdr.len = sizeof(hdr) + sizeof(struct client_lease) +
1731             sizeof(size_t) + fn_len + sizeof(size_t) + sn_len +
1732             sizeof(size_t) + pr_len;
1733
1734         for (i = 0; i < 256; i++)
1735                 hdr.len += sizeof(int) + lease->options[i].len;
1736
1737         scripttime = time(NULL);
1738
1739         buf = buf_open(hdr.len);
1740
1741         buf_add(buf, &hdr, sizeof(hdr));
1742         buf_add(buf, lease, sizeof(struct client_lease));
1743         buf_add(buf, &fn_len, sizeof(fn_len));
1744         buf_add(buf, lease->filename, fn_len);
1745         buf_add(buf, &sn_len, sizeof(sn_len));
1746         buf_add(buf, lease->server_name, sn_len);
1747         buf_add(buf, &pr_len, sizeof(pr_len));
1748         buf_add(buf, prefix, pr_len);
1749
1750         for (i = 0; i < 256; i++) {
1751                 buf_add(buf, &lease->options[i].len,
1752                     sizeof(lease->options[i].len));
1753                 buf_add(buf, lease->options[i].data,
1754                     lease->options[i].len);
1755         }
1756
1757         buf_close(privfd, buf);
1758 }
1759
1760 int
1761 script_go(void)
1762 {
1763         struct imsg_hdr  hdr;
1764         struct buf      *buf;
1765         int              ret;
1766
1767         scripttime = time(NULL);
1768
1769         hdr.code = IMSG_SCRIPT_GO;
1770         hdr.len = sizeof(struct imsg_hdr);
1771
1772         buf = buf_open(hdr.len);
1773
1774         buf_add(buf, &hdr, sizeof(hdr));
1775         buf_close(privfd, buf);
1776
1777         bzero(&hdr, sizeof(hdr));
1778         buf_read(privfd, &hdr, sizeof(hdr));
1779         if (hdr.code != IMSG_SCRIPT_GO_RET)
1780                 error("unexpected msg type %u", hdr.code);
1781         if (hdr.len != sizeof(hdr) + sizeof(int))
1782                 error("received corrupted message");
1783         buf_read(privfd, &ret, sizeof(ret));
1784
1785         return (ret);
1786 }
1787
1788 int
1789 priv_script_go(void)
1790 {
1791         char *scriptName, *argv[2], **envp;
1792         int pid, wpid, wstatus;
1793
1794         scripttime = time(NULL);
1795
1796         scriptName = config->script_name;
1797         envp = client->scriptEnv;
1798
1799         argv[0] = scriptName;
1800         argv[1] = NULL;
1801
1802         pid = fork();
1803         if (pid < 0) {
1804                 error("fork: %m");
1805                 wstatus = 0;
1806         } else if (pid) {
1807                 do {
1808                         wpid = wait(&wstatus);
1809                 } while (wpid != pid && wpid > 0);
1810                 if (wpid < 0) {
1811                         error("wait: %m");
1812                         wstatus = 0;
1813                 }
1814         } else {
1815                 execve(scriptName, argv, envp);
1816                 error("execve (%s, ...): %m", scriptName);
1817         }
1818
1819         script_flush_env();
1820
1821         return (WEXITSTATUS(wstatus));
1822 }
1823
1824 void
1825 script_set_env(const char *prefix, const char *name, const char *value)
1826 {
1827         int i, j, namelen;
1828
1829         namelen = strlen(name);
1830
1831         for (i = 0; client->scriptEnv[i]; i++)
1832                 if (strncmp(client->scriptEnv[i], name, namelen) == 0 &&
1833                     client->scriptEnv[i][namelen] == '=')
1834                         break;
1835
1836         if (client->scriptEnv[i])
1837                 /* Reuse the slot. */
1838                 free(client->scriptEnv[i]);
1839         else {
1840                 /* New variable.  Expand if necessary. */
1841                 if (i >= client->scriptEnvsize - 1) {
1842                         char **newscriptEnv;
1843                         int newscriptEnvsize = client->scriptEnvsize + 50;
1844
1845                         newscriptEnv = realloc(client->scriptEnv,
1846                             newscriptEnvsize);
1847                         if (newscriptEnv == NULL) {
1848                                 free(client->scriptEnv);
1849                                 client->scriptEnv = NULL;
1850                                 client->scriptEnvsize = 0;
1851                                 error("script_set_env: no memory for variable");
1852                         }
1853                         client->scriptEnv = newscriptEnv;
1854                         client->scriptEnvsize = newscriptEnvsize;
1855                 }
1856                 /* need to set the NULL pointer at end of array beyond
1857                    the new slot. */
1858                 client->scriptEnv[i + 1] = NULL;
1859         }
1860         /* Allocate space and format the variable in the appropriate slot. */
1861         client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 +
1862             strlen(value) + 1);
1863         if (client->scriptEnv[i] == NULL)
1864                 error("script_set_env: no memory for variable assignment");
1865
1866         /* No `` or $() command substitution allowed in environment values! */
1867         for (j = 0; j < strlen(value); j++)
1868                 switch (value[j]) {
1869                 case '`':
1870                 case '$':
1871                         error("illegal character (%c) in value '%s'", value[j],
1872                             value);
1873                         /* not reached */
1874                 }
1875         snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) +
1876             1 + strlen(value) + 1, "%s%s=%s", prefix, name, value);
1877 }
1878
1879 void
1880 script_flush_env(void)
1881 {
1882         int i;
1883
1884         for (i = 0; client->scriptEnv[i]; i++) {
1885                 free(client->scriptEnv[i]);
1886                 client->scriptEnv[i] = NULL;
1887         }
1888         client->scriptEnvsize = 0;
1889 }
1890
1891 int
1892 dhcp_option_ev_name(char *buf, size_t buflen, const struct option *option)
1893 {
1894         size_t i;
1895
1896         for (i = 0; option->name[i]; i++) {
1897                 if (i + 1 == buflen)
1898                         return 0;
1899                 if (option->name[i] == '-')
1900                         buf[i] = '_';
1901                 else
1902                         buf[i] = option->name[i];
1903         }
1904
1905         buf[i] = 0;
1906         return 1;
1907 }
1908
1909 void
1910 go_daemon(void)
1911 {
1912         static int state = 0;
1913
1914         if (no_daemon || state)
1915                 return;
1916
1917         state = 1;
1918
1919         /* Stop logging to stderr... */
1920         log_perror = 0;
1921
1922         if (daemon(1, 0) == -1)
1923                 error("daemon");
1924
1925         /* we are chrooted, daemon(3) fails to open /dev/null */
1926         if (nullfd != -1) {
1927                 dup2(nullfd, STDIN_FILENO);
1928                 dup2(nullfd, STDOUT_FILENO);
1929                 dup2(nullfd, STDERR_FILENO);
1930                 close(nullfd);
1931                 nullfd = -1;
1932         }
1933 }
1934
1935 int
1936 check_option(struct client_lease *l, int option)
1937 {
1938         char *opbuf;
1939         char *sbuf;
1940
1941         /* we use this, since this is what gets passed to dhclient-script */
1942
1943         opbuf = pretty_print_option(option, l->options[option].data,
1944             l->options[option].len, 0, 0);
1945
1946         sbuf = option_as_string(option, l->options[option].data,
1947             l->options[option].len);
1948
1949         switch (option) {
1950         case DHO_SUBNET_MASK:
1951         case DHO_TIME_SERVERS:
1952         case DHO_NAME_SERVERS:
1953         case DHO_ROUTERS:
1954         case DHO_DOMAIN_NAME_SERVERS:
1955         case DHO_LOG_SERVERS:
1956         case DHO_COOKIE_SERVERS:
1957         case DHO_LPR_SERVERS:
1958         case DHO_IMPRESS_SERVERS:
1959         case DHO_RESOURCE_LOCATION_SERVERS:
1960         case DHO_SWAP_SERVER:
1961         case DHO_BROADCAST_ADDRESS:
1962         case DHO_NIS_SERVERS:
1963         case DHO_NTP_SERVERS:
1964         case DHO_NETBIOS_NAME_SERVERS:
1965         case DHO_NETBIOS_DD_SERVER:
1966         case DHO_FONT_SERVERS:
1967         case DHO_DHCP_SERVER_IDENTIFIER:
1968                 if (!ipv4addrs(opbuf)) {
1969                         warning("Invalid IP address in option: %s", opbuf);
1970                         return (0);
1971                 }
1972                 return (1);
1973         case DHO_HOST_NAME:
1974         case DHO_DOMAIN_NAME:
1975         case DHO_NIS_DOMAIN:
1976                 if (!res_hnok(sbuf)) {
1977                         warning("Bogus Host Name option %d: %s (%s)", option,
1978                             sbuf, opbuf);
1979                         l->options[option].len = 0;
1980                         free(l->options[option].data);
1981                 }
1982                 return (1);
1983         case DHO_PAD:
1984         case DHO_TIME_OFFSET:
1985         case DHO_BOOT_SIZE:
1986         case DHO_MERIT_DUMP:
1987         case DHO_ROOT_PATH:
1988         case DHO_EXTENSIONS_PATH:
1989         case DHO_IP_FORWARDING:
1990         case DHO_NON_LOCAL_SOURCE_ROUTING:
1991         case DHO_POLICY_FILTER:
1992         case DHO_MAX_DGRAM_REASSEMBLY:
1993         case DHO_DEFAULT_IP_TTL:
1994         case DHO_PATH_MTU_AGING_TIMEOUT:
1995         case DHO_PATH_MTU_PLATEAU_TABLE:
1996         case DHO_INTERFACE_MTU:
1997         case DHO_ALL_SUBNETS_LOCAL:
1998         case DHO_PERFORM_MASK_DISCOVERY:
1999         case DHO_MASK_SUPPLIER:
2000         case DHO_ROUTER_DISCOVERY:
2001         case DHO_ROUTER_SOLICITATION_ADDRESS:
2002         case DHO_STATIC_ROUTES:
2003         case DHO_TRAILER_ENCAPSULATION:
2004         case DHO_ARP_CACHE_TIMEOUT:
2005         case DHO_IEEE802_3_ENCAPSULATION:
2006         case DHO_DEFAULT_TCP_TTL:
2007         case DHO_TCP_KEEPALIVE_INTERVAL:
2008         case DHO_TCP_KEEPALIVE_GARBAGE:
2009         case DHO_VENDOR_ENCAPSULATED_OPTIONS:
2010         case DHO_NETBIOS_NODE_TYPE:
2011         case DHO_NETBIOS_SCOPE:
2012         case DHO_X_DISPLAY_MANAGER:
2013         case DHO_DHCP_REQUESTED_ADDRESS:
2014         case DHO_DHCP_LEASE_TIME:
2015         case DHO_DHCP_OPTION_OVERLOAD:
2016         case DHO_DHCP_MESSAGE_TYPE:
2017         case DHO_DHCP_PARAMETER_REQUEST_LIST:
2018         case DHO_DHCP_MESSAGE:
2019         case DHO_DHCP_MAX_MESSAGE_SIZE:
2020         case DHO_DHCP_RENEWAL_TIME:
2021         case DHO_DHCP_REBINDING_TIME:
2022         case DHO_DHCP_CLASS_IDENTIFIER:
2023         case DHO_DHCP_CLIENT_IDENTIFIER:
2024         case DHO_DHCP_USER_CLASS_ID:
2025         case DHO_END:
2026                 return (1);
2027         default:
2028                 warning("unknown dhcp option value 0x%x", option);
2029                 return (unknown_ok);
2030         }
2031 }
2032
2033 int
2034 res_hnok(const char *name)
2035 {
2036         const char *dn = name;
2037         int pch = '.', ch = *dn++;
2038         int warn = 0;
2039
2040         while (ch != '\0') {
2041                 int nch = *dn++;
2042
2043                 if (ch == '.') {
2044                         ;
2045                 } else if (pch == '.' || nch == '.' || nch == '\0') {
2046                         if (!isalnum(ch))
2047                                 return (0);
2048                 } else if (!isalnum(ch) && ch != '-' && ch != '_')
2049                                 return (0);
2050                 else if (ch == '_' && warn == 0) {
2051                         warning("warning: hostname %s contains an "
2052                             "underscore which violates RFC 952", name);
2053                         warn++;
2054                 }
2055                 pch = ch, ch = nch;
2056         }
2057         return (1);
2058 }
2059
2060 /* Does buf consist only of dotted decimal ipv4 addrs?
2061  * return how many if so,
2062  * otherwise, return 0
2063  */
2064 int
2065 ipv4addrs(char * buf)
2066 {
2067         struct in_addr jnk;
2068         int count = 0;
2069
2070         while (inet_aton(buf, &jnk) == 1){
2071                 count++;
2072                 while (*buf == '.' || isdigit(*buf))
2073                         buf++;
2074                 if (*buf == '\0')
2075                         return (count);
2076                 while (*buf ==  ' ')
2077                         buf++;
2078         }
2079         return (0);
2080 }
2081
2082 char *
2083 option_as_string(unsigned int code, unsigned char *data, int len)
2084 {
2085         static char optbuf[32768]; /* XXX */
2086         char *op = optbuf;
2087         int opleft = sizeof(optbuf);
2088         unsigned char *dp = data;
2089
2090         if (code > 255)
2091                 error("option_as_string: bad code %d", code);
2092
2093         for (; dp < data + len; dp++) {
2094                 if (!isascii(*dp) || !isprint(*dp)) {
2095                         if (dp + 1 != data + len || *dp != 0) {
2096                                 size_t oplen;
2097                                 snprintf(op, opleft, "\\%03o", *dp);
2098                                 oplen = strlen(op);
2099                                 op += oplen;
2100                                 opleft -= oplen;
2101                         }
2102                 } else if (*dp == '"' || *dp == '\'' || *dp == '$' ||
2103                     *dp == '`' || *dp == '\\') {
2104                         *op++ = '\\';
2105                         *op++ = *dp;
2106                         opleft -= 2;
2107                 } else {
2108                         *op++ = *dp;
2109                         opleft--;
2110                 }
2111         }
2112         if (opleft < 1)
2113                 goto toobig;
2114         *op = 0;
2115         return optbuf;
2116 toobig:
2117         warning("dhcp option too large");
2118         return "<error>";
2119 }
2120
2121 int
2122 fork_privchld(int fd, int fd2)
2123 {
2124         struct pollfd pfd[1];
2125         int nfds, pfail = 0;
2126
2127         switch (fork()) {
2128         case -1:
2129                 error("cannot fork");
2130                 break;
2131         case 0:
2132                 break;
2133         default:
2134                 return (0);
2135         }
2136
2137         if (chdir("/") == -1)
2138                 error("chdir(\"/\")");
2139
2140         setproctitle("%s [priv]", ifi->name);
2141
2142         dup2(nullfd, STDIN_FILENO);
2143         dup2(nullfd, STDOUT_FILENO);
2144         dup2(nullfd, STDERR_FILENO);
2145         close(nullfd);
2146         close(fd2);
2147
2148         for (;;) {
2149                 pfd[0].fd = fd;
2150                 pfd[0].events = POLLIN;
2151                 if ((nfds = poll(pfd, 1, INFTIM)) == -1)
2152                         if (errno != EINTR)
2153                                 error("poll error");
2154
2155                 /*
2156                  * Handle temporary errors, but bail if they persist.
2157                  */
2158                 if (nfds == 0 || !(pfd[0].revents & POLLIN)) {
2159                         if (pfail > POLL_FAILURES)
2160                                 error("poll failed > %d times", POLL_FAILURES);
2161                         sleep(pfail * POLL_FAILURE_WAIT);
2162                         pfail++;
2163                         continue;
2164                 }
2165
2166                 dispatch_imsg(fd);
2167         }
2168 }