sbin/dhclient/dhclient.c

   1 /*
   2  * Copyright 2004 Henning Brauer <henning@openbsd.org>
   3  * Copyright (c) 1995, 1996, 1997, 1998, 1999
   4  * The Internet Software Consortium.    All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of The Internet Software Consortium nor the names
  16  *    of its contributors may be used to endorse or promote products derived
  17  *    from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
  20  * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  21  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  22  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  23  * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
  24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  25  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  26  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  27  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  28  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  30  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * This software has been written for the Internet Software Consortium
  34  * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
  35  * Enterprises.  To learn more about the Internet Software Consortium,
  36  * see ``http://www.vix.com/isc''.  To learn more about Vixie
  37  * Enterprises, see ``http://www.vix.com''.
  38  *
  39  * This client was substantially modified and enhanced by Elliot Poger
  40  * for use on Linux while he was working on the MosquitoNet project at
  41  * Stanford.
  42  *
  43  * The current version owes much to Elliot's Linux enhancements, but
  44  * was substantially reorganized and partially rewritten by Ted Lemon
  45  * so as to use the same networking framework that the Internet Software
  46  * Consortium DHCP server uses.   Much system-specific configuration code
  47  * was moved into a shell script so that as support for more operating
  48  * systems is added, it will not be necessary to port and maintain
  49  * system-specific configuration code to these operating systems - instead,
  50  * the shell script can invoke the native tools to accomplish the same
  51  * purpose.
  52  */
  53 #include <sys/ioctl.h>
  54
  55 #include <ctype.h>
  56 #include <poll.h>
  57 #include <pwd.h>
  58 #include <signal.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 char *path_dhclient_conf = _PATH_DHCLIENT_CONF;
  71 char *path_dhclient_db = NULL;
  72 char *orig_ifname;
  73
  74 int log_perror = 1;
  75 int privfd;
  76 int nullfd = -1;
  77 int no_daemon;
  78 int stayalive = 0;
  79 int unknown_ok = 1;
  80 int routefd = -1;
  81 pid_t monitor_pid;
  82
  83 struct iaddr iaddr_broadcast = { 4, { 255, 255, 255, 255 } };
  84 struct in_addr inaddr_any;
  85 struct sockaddr_in sockaddr_broadcast;
  86
  87 struct interface_info *ifi;
  88 struct client_state *client;
  89 struct client_config *config;
  90
  91 int             findproto(char *, int);
  92 struct sockaddr *get_ifa(char *, int);
  93 void            usage(void);
  94 int             check_option(struct client_lease *l, int option);
  95 int             ipv4addrs(char * buf);
  96 int             res_hnok(const char *dn);
  97 char            *option_as_string(unsigned int code, unsigned char *data, int len);
  98 int             fork_privchld(int, int);
  99 void            get_ifname(char *, char *);
 100 static void     sig_handle(int sig);
 101 static int      killclient(int fd);
 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                         RT_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                         RT_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         struct sockaddr *sa;
 167         struct iaddr a;
 168         ssize_t n;
 169         char *errmsg, buf[64];
 170
 171         do {
 172                 n = read(routefd, &msg, sizeof(msg));
 173         } while (n == -1 && errno == EINTR);
 174
 175         rtm = (struct rt_msghdr *)msg;
 176         if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen ||
 177             rtm->rtm_version != RTM_VERSION)
 178                 return;
 179
 180         switch (rtm->rtm_type) {
 181         case RTM_NEWADDR:
 182                 ifam = (struct ifa_msghdr *)rtm;
 183                 if (ifam->ifam_index != ifi->index)
 184                         break;
 185                 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
 186                         break;
 187                 sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs);
 188                 if (sa == NULL) {
 189                         errmsg = "sa == NULL";
 190                         goto die;
 191                 }
 192
 193                 if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf))
 194                         error("king bula sez: len mismatch");
 195                 memcpy(a.iabuf, &((struct sockaddr_in *)sa)->sin_addr, a.len);
 196                 if (addr_eq(a, defaddr))
 197                         break;
 198
 199                 /* state_panic() can try unexpired existing leases */
 200                 if (client->active && addr_eq(a, client->active->address))
 201                         break;
 202                 for (l = client->leases; l != NULL; l = l->next)
 203                         if (addr_eq(a, l->address))
 204                                 break;
 205
 206                 if (l != NULL)
 207                         /* new addr is the one we set */
 208                         break;
 209                 snprintf(buf, sizeof(buf), "%s: %s",
 210                     "new address not one we set", piaddr(a));
 211                 errmsg = buf;
 212                 goto die;
 213         case RTM_DELADDR:
 214                 ifam = (struct ifa_msghdr *)rtm;
 215                 if (ifam->ifam_index != ifi->index)
 216                         break;
 217                 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
 218                         break;
 219                 /* XXX check addrs like RTM_NEWADDR instead of this? */
 220                 if (scripttime == 0 || time(NULL) < scripttime + 10)
 221                         break;
 222                 errmsg = "interface address deleted";
 223                 goto die;
 224         case RTM_IFINFO:
 225                 ifm = (struct if_msghdr *)rtm;
 226                 if (ifm->ifm_index != ifi->index)
 227                         break;
 228                 if ((rtm->rtm_flags & RTF_UP) == 0) {
 229                         errmsg = "interface down";
 230                         goto die;
 231                 }
 232
 233                 linkstat =
 234                     LINK_STATE_IS_UP(ifm->ifm_data.ifi_link_state) ? 1 : 0;
 235                 if (linkstat != ifi->linkstat) {
 236 #ifdef DEBUG
 237                         debug("link state %s -> %s",
 238                             ifi->linkstat ? "up" : "down",
 239                             linkstat ? "up" : "down");
 240 #endif
 241                         ifi->linkstat = interface_status(ifi->name);
 242                         if (ifi->linkstat) {
 243                                 client->state = S_REBOOTING;
 244                                 state_reboot();
 245                         }
 246                 }
 247                 break;
 248         case RTM_IFANNOUNCE:
 249                 ifan = (struct if_announcemsghdr *)rtm;
 250                 if (ifan->ifan_what == IFAN_DEPARTURE &&
 251                     ifan->ifan_index == ifi->index) {
 252                         errmsg = "interface departure";
 253                         goto die;
 254                 }
 255                 break;
 256         default:
 257                 break;
 258         }
 259         return;
 260
 261 die:
 262         script_init("FAIL");
 263         script_go();
 264         error("routehandler: %s", errmsg);
 265 }
 266
 267 int
 268 main(int argc, char *argv[])
 269 {
 270         int ch, fd;
 271         int pipe_fd[2];
 272         int quiet = 0;
 273         int dokillclient = 0;
 274         int i;
 275         struct passwd *pw;
 276
 277         /* Initially, log errors to stderr as well as to syslogd. */
 278         openlog(getprogname(), LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY);
 279         setlogmask(LOG_UPTO(LOG_INFO));
 280
 281         signal(SIGINT, sig_handle);
 282         signal(SIGHUP, sig_handle);
 283
 284         while ((ch = getopt(argc, argv, "c:dl:quwx")) != -1) {
 285                 switch (ch) {
 286                 case 'c':
 287                         path_dhclient_conf = optarg;
 288                         break;
 289                 case 'd':
 290                         no_daemon = 1;
 291                         break;
 292                 case 'l':
 293                         path_dhclient_db = optarg;
 294                         break;
 295                 case 'q':
 296                         quiet = 1;
 297                         break;
 298                 case 'u':
 299                         unknown_ok = 0;
 300                         break;
 301                 case 'w':
 302                         stayalive = 1;
 303                         break;
 304                 case 'x':
 305                         dokillclient = 1;
 306                         break;
 307                 default:
 308                         usage();
 309                 }
 310         }
 311
 312         argc -= optind;
 313         argv += optind;
 314
 315         if (argc != 1)
 316                 usage();
 317         orig_ifname = argv[0];
 318
 319         if (dokillclient) {
 320                 char buf[256];
 321
 322                 snprintf(buf, sizeof(buf),
 323                          "/var/run/dhclient.%s.pid", orig_ifname);
 324                 fd = open(buf, O_RDWR, 0644);
 325                 if (fd < 0 || killclient(fd)) {
 326                         fprintf(stderr,
 327                                 "no dhclient running on %s\n",
 328                                 orig_ifname);
 329                 } else {
 330                         fprintf(stderr,
 331                                 "stopping dhclient on %s\n",
 332                                 orig_ifname);
 333                 }
 334                 if (fd >= 0)
 335                         close(fd);
 336                 exit(1);
 337         }
 338
 339         if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
 340                 error("cannot open %s: %m", _PATH_DEVNULL);
 341
 342         /*
 343          * If asked to stay alive forever get our daemon going right now
 344          * Then set up to fork/monitor and refork on exit.
 345          *
 346          * When I say 'forever' I really mean it.  If there are configuration
 347          * problems or missing interfaces or whatever, dhclient will wait
 348          * 10 seconds and try again.
 349          */
 350         if (stayalive) {
 351                 pid_t pid;
 352                 pid_t rpid;
 353                 int omask;
 354
 355                 go_daemon();
 356
 357                 for (;;) {
 358                         omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP));
 359                         pid = fork();
 360                         if (pid > 0)
 361                                 monitor_pid = pid;
 362                         sigsetmask(omask);
 363
 364                         if (pid == 0)   /* child falls out of loop */
 365                                 break;
 366                         while (pid > 0) {
 367                                 rpid = waitpid(pid, NULL, 0);
 368                                 if (rpid == pid)
 369                                         break;
 370                                 if (rpid != EINTR)
 371                                         break;
 372                         }
 373                         sleep(10);
 374                 }
 375         }
 376
 377         ifi = calloc(1, sizeof(*ifi));
 378         if (ifi == NULL)
 379                 error("ifi calloc");
 380         client = calloc(1, sizeof(*client));
 381         if (client == NULL)
 382                 error("client calloc");
 383         config = calloc(1, sizeof(*config));
 384         if (config == NULL)
 385                 error("config calloc");
 386
 387         get_ifname(ifi->name, argv[0]);
 388
 389         if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s",
 390             _PATH_DHCLIENT_DB, ifi->name) == -1)
 391                 error("asprintf");
 392
 393         if (quiet)
 394                 log_perror = 0;
 395
 396         tzset();
 397
 398         memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast));
 399         sockaddr_broadcast.sin_family = AF_INET;
 400         sockaddr_broadcast.sin_port = htons(REMOTE_PORT);
 401         sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST;
 402         sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast);
 403         inaddr_any.s_addr = INADDR_ANY;
 404
 405         read_client_conf();
 406
 407         if (interface_status(ifi->name) == 0) {
 408                 interface_link_forceup(ifi->name);
 409                 /* Give it up to 4 seconds of silent grace to find link */
 410                 i = -4;
 411         } else {
 412                 i = 0;
 413         }
 414
 415         while (!(ifi->linkstat = interface_status(ifi->name))) {
 416                 if (i == 0)
 417                         fprintf(stderr, "%s: no link ...", ifi->name);
 418                 else if (i > 0)
 419                         fprintf(stderr, ".");
 420                 fflush(stderr);
 421                 if (++i > config->link_timeout) {
 422                         fprintf(stderr, " sleeping\n");
 423                         goto dispatch;
 424                 }
 425                 sleep(1);
 426         }
 427         if (i > 0)
 428                 fprintf(stderr, " got link\n");
 429
 430  dispatch:
 431         if ((pw = getpwnam("_dhcp")) == NULL)
 432                 error("no such user: _dhcp");
 433
 434         if (pipe(pipe_fd) == -1)
 435                 error("pipe");
 436
 437         go_daemon();
 438         fork_privchld(pipe_fd[0], pipe_fd[1]);
 439
 440         close(pipe_fd[0]);
 441         privfd = pipe_fd[1];
 442
 443         if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1)
 444                 error("can't open and lock %s: %m", path_dhclient_db);
 445         read_client_leases();
 446         if ((leaseFile = fopen(path_dhclient_db, "w")) == NULL)
 447                 error("can't open %s: %m", path_dhclient_db);
 448         rewrite_client_leases();
 449         close(fd);
 450
 451         if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
 452                 error("socket(PF_ROUTE, SOCK_RAW): %m");
 453
 454         /* set up the interface */
 455         discover_interface();
 456
 457         if (chroot(_PATH_VAREMPTY) == -1)
 458                 error("chroot");
 459         if (chdir("/") == -1)
 460                 error("chdir(\"/\")");
 461
 462         if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1)
 463                 error("setresgid");
 464         if (setgroups(1, &pw->pw_gid) == -1)
 465                 error("setgroups");
 466         if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
 467                 error("setresuid");
 468
 469         endpwent();
 470
 471         setproctitle("%s", ifi->name);
 472
 473         if (ifi->linkstat) {
 474                 client->state = S_REBOOTING;
 475                 state_reboot();
 476         }
 477         dispatch();
 478
 479         /* not reached */
 480         return (0);
 481 }
 482
 483 void
 484 usage(void)
 485 {
 486         fprintf(stderr, "usage: %s [-dqu] [-c file] [-l file] interface\n",
 487             getprogname());
 488         exit(1);
 489 }
 490
 491 /*
 492  * Individual States:
 493  *
 494  * Each routine is called from the dhclient_state_machine() in one of
 495  * these conditions:
 496  * -> entering INIT state
 497  * -> recvpacket_flag == 0: timeout in this state
 498  * -> otherwise: received a packet in this state
 499  *
 500  * Return conditions as handled by dhclient_state_machine():
 501  * Returns 1, sendpacket_flag = 1: send packet, reset timer.
 502  * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone).
 503  * Returns 0: finish the nap which was interrupted for no good reason.
 504  *
 505  * Several per-interface variables are used to keep track of the process:
 506  *   active_lease: the lease that is being used on the interface
 507  *                 (null pointer if not configured yet).
 508  *   offered_leases: leases corresponding to DHCPOFFER messages that have
 509  *                   been sent to us by DHCP servers.
 510  *   acked_leases: leases corresponding to DHCPACK messages that have been
 511  *                 sent to us by DHCP servers.
 512  *   sendpacket: DHCP packet we're trying to send.
 513  *   destination: IP address to send sendpacket to
 514  * In addition, there are several relevant per-lease variables.
 515  *   T1_expiry, T2_expiry, lease_expiry: lease milestones
 516  * In the active lease, these control the process of renewing the lease;
 517  * In leases on the acked_leases list, this simply determines when we
 518  * can no longer legitimately use the lease.
 519  */
 520 void
 521 state_reboot(void)
 522 {
 523         /* Cancel all timeouts, since a link state change gets us here
 524            and can happen anytime. */
 525         cancel_timeout();
 526
 527         /* If we don't remember an active lease, go straight to INIT. */
 528         if (!client->active || client->active->is_bootp) {
 529                 client->state = S_INIT;
 530                 state_init();
 531                 return;
 532         }
 533
 534         /* make_request doesn't initialize xid because it normally comes
 535            from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER,
 536            so pick an xid now. */
 537         client->xid = arc4random();
 538
 539         /* Make a DHCPREQUEST packet, and set appropriate per-interface
 540            flags. */
 541         make_request(client->active);
 542         client->destination = iaddr_broadcast;
 543         client->first_sending = time(NULL);
 544         client->interval = 0;
 545
 546         send_request();
 547 }
 548
 549 /*
 550  * Called when a lease has completely expired and we've
 551  * been unable to renew it.
 552  */
 553 void
 554 state_init(void)
 555 {
 556         /* Make a DHCPDISCOVER packet, and set appropriate per-interface
 557            flags. */
 558         make_discover(client->active);
 559         client->xid = client->packet.xid;
 560         client->destination = iaddr_broadcast;
 561         client->state = S_SELECTING;
 562         client->first_sending = time(NULL);
 563         client->interval = 0;
 564
 565         send_discover();
 566 }
 567
 568 /*
 569  * state_selecting is called when one or more DHCPOFFER packets
 570  * have been received and a configurable period of time has passed.
 571  */
 572 void
 573 state_selecting(void)
 574 {
 575         struct client_lease *lp, *next, *picked;
 576         time_t cur_time;
 577
 578         /* Cancel state_selecting and send_discover timeouts, since either
 579            one could have got us here. */
 580         cancel_timeout();
 581
 582         /* We have received one or more DHCPOFFER packets.   Currently,
 583            the only criterion by which we judge leases is whether or
 584            not we get a response when we arp for them. */
 585         picked = NULL;
 586         for (lp = client->offered_leases; lp; lp = next) {
 587                 next = lp->next;
 588
 589                 if (!picked) {
 590                         picked = lp;
 591                 } else {
 592                         make_decline(lp);
 593                         send_decline();
 594                         free_client_lease(lp);
 595                 }
 596         }
 597         client->offered_leases = NULL;
 598
 599         /* If we just tossed all the leases we were offered, go back
 600            to square one. */
 601         if (!picked) {
 602                 client->state = S_INIT;
 603                 state_init();
 604                 return;
 605         }
 606         picked->next = NULL;
 607
 608         time(&cur_time);
 609
 610         /* If it was a BOOTREPLY, we can just take the address right now. */
 611         if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
 612                 client->new = picked;
 613
 614                 /* Make up some lease expiry times
 615                    XXX these should be configurable. */
 616                 client->new->expiry = cur_time + 12000;
 617                 client->new->renewal += cur_time + 8000;
 618                 client->new->rebind += cur_time + 10000;
 619
 620                 client->state = S_REQUESTING;
 621
 622                 /* Bind to the address we received. */
 623                 bind_lease();
 624                 return;
 625         }
 626
 627         /* Go to the REQUESTING state. */
 628         client->destination = iaddr_broadcast;
 629         client->state = S_REQUESTING;
 630         client->first_sending = cur_time;
 631         client->interval = 0;
 632
 633         /* Make a DHCPREQUEST packet from the lease we picked. */
 634         make_request(picked);
 635         client->xid = client->packet.xid;
 636
 637         /* Toss the lease we picked - we'll get it back in a DHCPACK. */
 638         free_client_lease(picked);
 639
 640         send_request();
 641 }
 642
 643 void
 644 dhcpack(struct iaddr client_addr, struct option_data *options)
 645 {
 646         struct client_lease *lease;
 647         time_t cur_time;
 648
 649
 650         if (client->state != S_REBOOTING &&
 651             client->state != S_REQUESTING &&
 652             client->state != S_RENEWING &&
 653             client->state != S_REBINDING)
 654                 return;
 655
 656
 657         lease = packet_to_lease(options);
 658         if (!lease) {
 659                 note("packet_to_lease failed.");
 660                 return;
 661         }
 662
 663         client->new = lease;
 664
 665         /* Stop resending DHCPREQUEST. */
 666         cancel_timeout();
 667
 668         /* Figure out the lease time. */
 669         if (client->new->options[DHO_DHCP_LEASE_TIME].data)
 670                 client->new->expiry =
 671                     getULong(client->new->options[DHO_DHCP_LEASE_TIME].data);
 672         else
 673                 client->new->expiry = DEFAULT_LEASE_TIME;
 674         /* A number that looks negative here is really just very large,
 675            because the lease expiry offset is unsigned. */
 676         if (client->new->expiry < 0)
 677                 client->new->expiry = TIME_MAX;
 678         /* XXX should be fixed by resetting the client state */
 679         if (client->new->expiry < 60)
 680                 client->new->expiry = 60;
 681
 682         /* Take the server-provided renewal time if there is one;
 683            otherwise figure it out according to the spec. */
 684         if (client->new->options[DHO_DHCP_RENEWAL_TIME].len)
 685                 client->new->renewal =
 686                     getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data);
 687         else
 688                 client->new->renewal = client->new->expiry / 2;
 689
 690         /* Same deal with the rebind time. */
 691         if (client->new->options[DHO_DHCP_REBINDING_TIME].len)
 692                 client->new->rebind =
 693                     getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data);
 694         else
 695                 client->new->rebind = client->new->renewal +
 696                     client->new->renewal / 2 + client->new->renewal / 4;
 697
 698         time(&cur_time);
 699
 700         client->new->expiry += cur_time;
 701         /* Lease lengths can never be negative. */
 702         if (client->new->expiry < cur_time)
 703                 client->new->expiry = TIME_MAX;
 704         client->new->renewal += cur_time;
 705         if (client->new->renewal < cur_time)
 706                 client->new->renewal = TIME_MAX;
 707         client->new->rebind += cur_time;
 708         if (client->new->rebind < cur_time)
 709                 client->new->rebind = TIME_MAX;
 710
 711         bind_lease();
 712 }
 713
 714 void
 715 bind_lease(void)
 716 {
 717         /* Run the client script with the new parameters. */
 718         script_init((client->state == S_REQUESTING ? "BOUND" :
 719             (client->state == S_RENEWING ? "RENEW" :
 720                 (client->state == S_REBOOTING ? "REBOOT" : "REBIND"))));
 721         if (client->active && client->state != S_REBOOTING)
 722                 script_write_params("old_", client->active);
 723         script_write_params("new_", client->new);
 724         script_go();
 725
 726         /* Replace the old active lease with the new one. */
 727         if (client->active)
 728                 free_client_lease(client->active);
 729         client->active = client->new;
 730         client->new = NULL;
 731
 732         /* Write out new leases file. */
 733         rewrite_client_leases();
 734
 735         /* Set timeout to start the renewal process. */
 736         set_timeout(client->active->renewal, state_bound);
 737
 738         note("bound to %s -- renewal in %lld seconds.",
 739             piaddr(client->active->address),
 740             (long long)(client->active->renewal - time(NULL)));
 741         client->state = S_BOUND;
 742 }
 743
 744 /*
 745  * state_bound is called when we've successfully bound to a particular
 746  * lease, but the renewal time on that lease has expired.   We are
 747  * expected to unicast a DHCPREQUEST to the server that gave us our
 748  * original lease.
 749  */
 750 void
 751 state_bound(void)
 752 {
 753         /* T1 has expired. */
 754         make_request(client->active);
 755         client->xid = client->packet.xid;
 756
 757         if (client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) {
 758                 memcpy(client->destination.iabuf,
 759                     client->active->options[DHO_DHCP_SERVER_IDENTIFIER].data,
 760                     4);
 761                 client->destination.len = 4;
 762         } else
 763                 client->destination = iaddr_broadcast;
 764
 765         client->first_sending = time(NULL);
 766         client->interval = 0;
 767         client->state = S_RENEWING;
 768
 769         send_request();
 770 }
 771
 772 void
 773 dhcpoffer(struct iaddr client_addr, struct option_data *options)
 774 {
 775         struct client_lease *lease, *lp;
 776         int i;
 777         time_t stop_selecting;
 778         char *name = options[DHO_DHCP_MESSAGE_TYPE].len ? "DHCPOFFER" :
 779             "BOOTREPLY";
 780
 781
 782         if (client->state != S_SELECTING)
 783                 return;
 784
 785
 786         /* If this lease doesn't supply the minimum required parameters,
 787            blow it off. */
 788         for (i = 0; config->required_options[i]; i++) {
 789                 if (!options[config->required_options[i]].len) {
 790                         note("%s isn't satisfactory.", name);
 791                         return;
 792                 }
 793         }
 794
 795         /* If we've already seen this lease, don't record it again. */
 796         for (lease = client->offered_leases;
 797             lease; lease = lease->next) {
 798                 if (lease->address.len == sizeof(client->packet.yiaddr) &&
 799                     !memcmp(lease->address.iabuf,
 800                     &client->packet.yiaddr, lease->address.len)) {
 801 #ifdef DEBUG
 802                         debug("%s already seen.", name);
 803 #endif
 804                         return;
 805                 }
 806         }
 807
 808         lease = packet_to_lease(options);
 809         if (!lease) {
 810                 note("packet_to_lease failed.");
 811                 return;
 812         }
 813
 814         /*
 815          * Reject offers whose subnet is already configured on another
 816          * interface.
 817          */
 818         if (subnet_exists(lease))
 819                 return;
 820
 821         /* If this lease was acquired through a BOOTREPLY, record that
 822            fact. */
 823         if (!options[DHO_DHCP_MESSAGE_TYPE].len)
 824                 lease->is_bootp = 1;
 825
 826         /* Figure out when we're supposed to stop selecting. */
 827         stop_selecting = client->first_sending + config->select_interval;
 828
 829         /* If this is the lease we asked for, put it at the head of the
 830            list, and don't mess with the arp request timeout. */
 831         if (addr_eq(lease->address, client->requested_address)) {
 832                 lease->next = client->offered_leases;
 833                 client->offered_leases = lease;
 834         } else {
 835                 /* Put the lease at the end of the list. */
 836                 lease->next = NULL;
 837                 if (!client->offered_leases)
 838                         client->offered_leases = lease;
 839                 else {
 840                         for (lp = client->offered_leases; lp->next;
 841                             lp = lp->next)
 842                                 ;       /* nothing */
 843                         lp->next = lease;
 844                 }
 845         }
 846
 847         /* If the selecting interval has expired, go immediately to
 848            state_selecting().  Otherwise, time out into
 849            state_selecting at the select interval. */
 850         if (stop_selecting <= time(NULL))
 851                 state_selecting();
 852         else {
 853                 set_timeout(stop_selecting, state_selecting);
 854         }
 855 }
 856
 857 /*
 858  * Allocate a client_lease structure and initialize it from the
 859  * parameters in the specified packet.
 860  */
 861 struct client_lease *
 862 packet_to_lease(struct option_data *options)
 863 {
 864         struct client_lease *lease;
 865         int i;
 866
 867         lease = malloc(sizeof(struct client_lease));
 868
 869         if (!lease) {
 870                 warning("dhcpoffer: no memory to record lease.");
 871                 return (NULL);
 872         }
 873
 874         memset(lease, 0, sizeof(*lease));
 875
 876         /* Copy the lease options. */
 877         for (i = 0; i < 256; i++) {
 878                 if (options[i].len) {
 879                         lease->options[i] = options[i];
 880                         options[i].data = NULL;
 881                         options[i].len = 0;
 882                         if (!check_option(lease, i)) {
 883                                 warning("Invalid lease option - ignoring offer");
 884                                 free_client_lease(lease);
 885                                 return (NULL);
 886                         }
 887                 }
 888         }
 889
 890         lease->address.len = sizeof(client->packet.yiaddr);
 891         memcpy(lease->address.iabuf, &client->packet.yiaddr,
 892             lease->address.len);
 893
 894         /* If the server name was filled out, copy it. */
 895         if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
 896             !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
 897             client->packet.sname[0]) {
 898                 lease->server_name = malloc(DHCP_SNAME_LEN + 1);
 899                 if (!lease->server_name) {
 900                         warning("dhcpoffer: no memory for server name.");
 901                         free_client_lease(lease);
 902                         return (NULL);
 903                 }
 904                 memcpy(lease->server_name, client->packet.sname,
 905                     DHCP_SNAME_LEN);
 906                 lease->server_name[DHCP_SNAME_LEN] = '\0';
 907                 if (!res_hnok(lease->server_name)) {
 908                         warning("Bogus server name %s", lease->server_name);
 909                         free(lease->server_name);
 910                         lease->server_name = NULL;
 911                 }
 912         }
 913
 914         /* Ditto for the filename. */
 915         if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len ||
 916             !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
 917             client->packet.file[0]) {
 918                 /* Don't count on the NUL terminator. */
 919                 lease->filename = malloc(DHCP_FILE_LEN + 1);
 920                 if (!lease->filename) {
 921                         warning("dhcpoffer: no memory for filename.");
 922                         free_client_lease(lease);
 923                         return (NULL);
 924                 }
 925                 memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN);
 926                 lease->filename[DHCP_FILE_LEN] = '\0';
 927         }
 928         return lease;
 929 }
 930
 931 void
 932 dhcpnak(struct iaddr client_addr, struct option_data *options)
 933 {
 934
 935         if (client->state != S_REBOOTING &&
 936             client->state != S_REQUESTING &&
 937             client->state != S_RENEWING &&
 938             client->state != S_REBINDING)
 939                 return;
 940
 941
 942         if (!client->active) {
 943                 note("DHCPNAK with no active lease.");
 944                 return;
 945         }
 946
 947         free_client_lease(client->active);
 948         client->active = NULL;
 949
 950         /* Stop sending DHCPREQUEST packets... */
 951         cancel_timeout();
 952
 953         client->state = S_INIT;
 954         state_init();
 955 }
 956
 957 /*
 958  * Send out a DHCPDISCOVER packet, and set a timeout to send out another
 959  * one after the right interval has expired.  If we don't get an offer by
 960  * the time we reach the panic interval, call the panic function.
 961  */
 962 void
 963 send_discover(void)
 964 {
 965         time_t cur_time;
 966         int interval, increase = 1;
 967
 968         time(&cur_time);
 969
 970         /* Figure out how long it's been since we started transmitting. */
 971         interval = cur_time - client->first_sending;
 972
 973         /* If we're past the panic timeout, call the script and tell it
 974            we haven't found anything for this interface yet. */
 975         if (interval > config->timeout) {
 976                 state_panic();
 977                 return;
 978         }
 979
 980         /*
 981          * If we're supposed to increase the interval, do so.  If it's
 982          * currently zero (i.e., we haven't sent any packets yet), set
 983          * it to initial_interval; otherwise, add to it a random
 984          * number between zero and two times itself.  On average, this
 985          * means that it will double with every transmission.
 986          */
 987         if (increase) {
 988                 if (!client->interval)
 989                         client->interval = config->initial_interval;
 990                 else {
 991                         client->interval += (arc4random() >> 2) %
 992                             (2 * client->interval);
 993                 }
 994
 995                 /* Don't backoff past cutoff. */
 996                 if (client->interval > config->backoff_cutoff)
 997                         client->interval = ((config->backoff_cutoff / 2)
 998                                  + ((arc4random() >> 2) %
 999                                     config->backoff_cutoff));
1000         } else if (!client->interval)
1001                 client->interval = config->initial_interval;
1002
1003         /* If the backoff would take us to the panic timeout, just use that
1004            as the interval. */
1005         if (cur_time + client->interval >
1006             client->first_sending + config->timeout)
1007                 client->interval = (client->first_sending +
1008                          config->timeout) - cur_time + 1;
1009
1010         /* Record the number of seconds since we started sending. */
1011         if (interval < 65536)
1012                 client->packet.secs = htons(interval);
1013         else
1014                 client->packet.secs = htons(65535);
1015         client->secs = client->packet.secs;
1016
1017         note("DHCPDISCOVER on %s to %s port %d interval %ld",
1018             ifi->name, inet_ntoa(sockaddr_broadcast.sin_addr),
1019             ntohs(sockaddr_broadcast.sin_port), client->interval);
1020
1021         send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1022
1023         set_timeout_interval(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         time_t cur_time;
1038
1039         note("No DHCPOFFERS received.");
1040
1041         /* We may not have an active lease, but we may have some
1042            predefined leases that we can try. */
1043         if (!client->active && client->leases)
1044                 goto activate_next;
1045
1046         /* Run through the list of leases and see if one can be used. */
1047         time(&cur_time);
1048         while (client->active) {
1049                 if (client->active->expiry > cur_time) {
1050                         note("Trying recorded lease %s",
1051                             piaddr(client->active->address));
1052                         /* Run the client script with the existing
1053                            parameters. */
1054                         script_init("TIMEOUT");
1055                         script_write_params("new_", client->active);
1056
1057                         /* If the old lease is still good and doesn't
1058                            yet need renewal, go into BOUND state and
1059                            timeout at the renewal time. */
1060                         if (!script_go()) {
1061                                 if (cur_time < client->active->renewal) {
1062                                         client->state = S_BOUND;
1063                                         note("bound: renewal in %lld seconds.",
1064                                             (long long)(client->active->renewal
1065                                             - cur_time));
1066                                         set_timeout(client->active->renewal,
1067                                             state_bound);
1068                                 } else {
1069                                         client->state = S_BOUND;
1070                                         note("bound: immediate renewal.");
1071                                         state_bound();
1072                                 }
1073                                 return;
1074                         }
1075                 }
1076
1077                 /* If there are no other leases, give up. */
1078                 if (!client->leases) {
1079                         client->leases = client->active;
1080                         client->active = NULL;
1081                         break;
1082                 }
1083
1084 activate_next:
1085                 /* Otherwise, put the active lease at the end of the
1086                    lease list, and try another lease.. */
1087                 for (lp = client->leases; lp->next; lp = lp->next)
1088                         ;
1089                 lp->next = client->active;
1090                 if (lp->next)
1091                         lp->next->next = NULL;
1092                 client->active = client->leases;
1093                 client->leases = client->leases->next;
1094
1095                 /* If we already tried this lease, we've exhausted the
1096                    set of leases, so we might as well give up for
1097                    now. */
1098                 if (client->active == loop)
1099                         break;
1100                 else if (!loop)
1101                         loop = client->active;
1102         }
1103
1104         /* No leases were available, or what was available didn't work, so
1105            tell the shell script that we failed to allocate an address,
1106            and try again later. */
1107         note("No working leases in persistent database - sleeping.");
1108         script_init("FAIL");
1109         script_go();
1110         client->state = S_INIT;
1111         set_timeout_interval(config->retry_interval, state_init);
1112 }
1113
1114 void
1115 send_request(void)
1116 {
1117         struct sockaddr_in destination;
1118         struct in_addr from;
1119         time_t cur_time;
1120         int interval;
1121
1122         time(&cur_time);
1123
1124         /* Figure out how long it's been since we started transmitting. */
1125         interval = (int)(cur_time - client->first_sending);
1126
1127         /* If we're in the INIT-REBOOT or REQUESTING state and we're
1128            past the reboot timeout, go to INIT and see if we can
1129            DISCOVER an address... */
1130         /* XXX In the INIT-REBOOT state, if we don't get an ACK, it
1131            means either that we're on a network with no DHCP server,
1132            or that our server is down.  In the latter case, assuming
1133            that there is a backup DHCP server, DHCPDISCOVER will get
1134            us a new address, but we could also have successfully
1135            reused our old address.  In the former case, we're hosed
1136            anyway.  This is not a win-prone situation. */
1137         if ((client->state == S_REBOOTING ||
1138             client->state == S_REQUESTING) &&
1139             interval > config->reboot_timeout) {
1140                 client->state = S_INIT;
1141                 cancel_timeout();
1142                 state_init();
1143                 return;
1144         }
1145
1146         /* If the lease has expired, relinquish the address and go back
1147            to the INIT state. */
1148         if (client->state != S_REQUESTING &&
1149             cur_time > client->active->expiry) {
1150                 /* Run the client script with the new parameters. */
1151                 script_init("EXPIRE");
1152                 script_write_params("old_", client->active);
1153                 script_go();
1154
1155                 client->state = S_INIT;
1156                 state_init();
1157                 return;
1158         }
1159
1160         /* Do the exponential backoff... */
1161         if (!client->interval)
1162                 client->interval = config->initial_interval;
1163         else
1164                 client->interval += ((arc4random() >> 2) %
1165                     (2 * client->interval));
1166
1167         /* Don't backoff past cutoff. */
1168         if (client->interval > config->backoff_cutoff)
1169                 client->interval = ((config->backoff_cutoff / 2) +
1170                     ((arc4random() >> 2) % client->interval));
1171
1172         /* If the backoff would take us to the expiry time, just set the
1173            timeout to the expiry time. */
1174         if (client->state != S_REQUESTING && cur_time + client->interval >
1175             client->active->expiry)
1176                 client->interval = client->active->expiry - cur_time + 1;
1177
1178         /* If the lease T2 time has elapsed, or if we're not yet bound,
1179            broadcast the DHCPREQUEST rather than unicasting. */
1180         memset(&destination, 0, sizeof(destination));
1181         if (client->state == S_REQUESTING ||
1182             client->state == S_REBOOTING ||
1183             cur_time > client->active->rebind)
1184                 destination.sin_addr.s_addr = INADDR_BROADCAST;
1185         else
1186                 memcpy(&destination.sin_addr.s_addr, client->destination.iabuf,
1187                     sizeof(destination.sin_addr.s_addr));
1188         destination.sin_port = htons(REMOTE_PORT);
1189         destination.sin_family = AF_INET;
1190         destination.sin_len = sizeof(destination);
1191
1192         if (client->state != S_REQUESTING)
1193                 memcpy(&from, client->active->address.iabuf, sizeof(from));
1194         else
1195                 from.s_addr = INADDR_ANY;
1196
1197         /* Record the number of seconds since we started sending. */
1198         if (client->state == S_REQUESTING)
1199                 client->packet.secs = client->secs;
1200         else {
1201                 if (interval < 65536)
1202                         client->packet.secs = htons(interval);
1203                 else
1204                         client->packet.secs = htons(65535);
1205         }
1206
1207         note("DHCPREQUEST on %s to %s port %d", ifi->name,
1208             inet_ntoa(destination.sin_addr), ntohs(destination.sin_port));
1209
1210         send_packet(from, &destination, NULL);
1211
1212         set_timeout_interval(client->interval, send_request);
1213 }
1214
1215 void
1216 send_decline(void)
1217 {
1218         note("DHCPDECLINE on %s to %s port %d", ifi->name,
1219             inet_ntoa(sockaddr_broadcast.sin_addr),
1220             ntohs(sockaddr_broadcast.sin_port));
1221
1222         send_packet(inaddr_any, &sockaddr_broadcast, NULL);
1223 }
1224
1225 void
1226 make_discover(struct client_lease *lease)
1227 {
1228         unsigned char discover = DHCPDISCOVER;
1229         struct option_data options[256];
1230         int i;
1231
1232         memset(options, 0, sizeof(options));
1233         memset(&client->packet, 0, sizeof(client->packet));
1234
1235         /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */
1236         i = DHO_DHCP_MESSAGE_TYPE;
1237         options[i].data = &discover;
1238         options[i].len = sizeof(discover);
1239
1240         /* Request the options we want */
1241         i  = DHO_DHCP_PARAMETER_REQUEST_LIST;
1242         options[i].data = config->requested_options;
1243         options[i].len = config->requested_option_count;
1244
1245         /* If we had an address, try to get it again. */
1246         if (lease) {
1247                 client->requested_address = lease->address;
1248                 i = DHO_DHCP_REQUESTED_ADDRESS;
1249                 options[i].data = lease->address.iabuf;
1250                 options[i].len = lease->address.len;
1251         } else
1252                 client->requested_address.len = 0;
1253
1254         /* Send any options requested in the config file. */
1255         for (i = 0; i < 256; i++)
1256                 if (!options[i].data &&
1257                     config->send_options[i].data) {
1258                         options[i].data = config->send_options[i].data;
1259                         options[i].len = config->send_options[i].len;
1260                 }
1261
1262         /* Set up the option buffer to fit in a minimal UDP packet. */
1263         i = cons_options(options);
1264         if (i == -1 || client->packet.options[i] != DHO_END)
1265                 error("options do not fit in DHCPDISCOVER packet.");
1266         client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1267         if (client->packet_length < BOOTP_MIN_LEN)
1268                 client->packet_length = BOOTP_MIN_LEN;
1269
1270         client->packet.op = BOOTREQUEST;
1271         client->packet.htype = ifi->hw_address.htype;
1272         client->packet.hlen = ifi->hw_address.hlen;
1273         client->packet.hops = 0;
1274         client->packet.xid = arc4random();
1275         client->packet.secs = 0; /* filled in by send_discover. */
1276         client->packet.flags = 0;
1277
1278         memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1279         memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1280         memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1281         memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1282         memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1283             ifi->hw_address.hlen);
1284 }
1285
1286 void
1287 make_request(struct client_lease * lease)
1288 {
1289         unsigned char request = DHCPREQUEST;
1290         struct option_data options[256];
1291         int i;
1292
1293         memset(options, 0, sizeof(options));
1294         memset(&client->packet, 0, sizeof(client->packet));
1295
1296         /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */
1297         i = DHO_DHCP_MESSAGE_TYPE;
1298         options[i].data = &request;
1299         options[i].len = sizeof(request);
1300
1301         /* Request the options we want */
1302         i = DHO_DHCP_PARAMETER_REQUEST_LIST;
1303         options[i].data = config->requested_options;
1304         options[i].len = config->requested_option_count;
1305
1306         /* If we are requesting an address that hasn't yet been assigned
1307            to us, use the DHCP Requested Address option. */
1308         if (client->state == S_REQUESTING) {
1309                 /* Send back the server identifier... */
1310                 i = DHO_DHCP_SERVER_IDENTIFIER;
1311                 options[i].data = lease->options[i].data;
1312                 options[i].len = lease->options[i].len;
1313         }
1314         if (client->state == S_REQUESTING ||
1315             client->state == S_REBOOTING) {
1316                 client->requested_address = lease->address;
1317                 i = DHO_DHCP_REQUESTED_ADDRESS;
1318                 options[i].data = lease->address.iabuf;
1319                 options[i].len = lease->address.len;
1320         } else
1321                 client->requested_address.len = 0;
1322
1323         /* Send any options requested in the config file. */
1324         for (i = 0; i < 256; i++)
1325                 if (!options[i].data && config->send_options[i].data) {
1326                         options[i].data = config->send_options[i].data;
1327                         options[i].len = config->send_options[i].len;
1328                 }
1329
1330         /* Set up the option buffer to fit in a minimal UDP packet. */
1331         i = cons_options(options);
1332         if (i == -1 || client->packet.options[i] != DHO_END)
1333                 error("options do not fit in DHCPREQUEST packet.");
1334         client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1335         if (client->packet_length < BOOTP_MIN_LEN)
1336                 client->packet_length = BOOTP_MIN_LEN;
1337
1338         client->packet.op = BOOTREQUEST;
1339         client->packet.htype = ifi->hw_address.htype;
1340         client->packet.hlen = ifi->hw_address.hlen;
1341         client->packet.hops = 0;
1342         client->packet.xid = client->xid;
1343         client->packet.secs = 0; /* Filled in by send_request. */
1344         client->packet.flags = 0;
1345
1346         /* If we own the address we're requesting, put it in ciaddr;
1347            otherwise set ciaddr to zero. */
1348         if (client->state == S_BOUND ||
1349             client->state == S_RENEWING ||
1350             client->state == S_REBINDING) {
1351                 memcpy(&client->packet.ciaddr,
1352                     lease->address.iabuf, lease->address.len);
1353         } else {
1354                 memset(&client->packet.ciaddr, 0,
1355                     sizeof(client->packet.ciaddr));
1356         }
1357
1358         memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1359         memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1360         memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1361         memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1362             ifi->hw_address.hlen);
1363 }
1364
1365 void
1366 make_decline(struct client_lease *lease)
1367 {
1368         struct option_data options[256];
1369         unsigned char decline = DHCPDECLINE;
1370         int i;
1371
1372         memset(options, 0, sizeof(options));
1373         memset(&client->packet, 0, sizeof(client->packet));
1374
1375         /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */
1376         i = DHO_DHCP_MESSAGE_TYPE;
1377         options[i].data = &decline;
1378         options[i].len = sizeof(decline);
1379
1380         /* Send back the server identifier... */
1381         i = DHO_DHCP_SERVER_IDENTIFIER;
1382         options[i].data = lease->options[i].data;
1383         options[i].len = lease->options[i].len;
1384
1385         /* Send back the address we're declining. */
1386         i = DHO_DHCP_REQUESTED_ADDRESS;
1387         options[i].data = lease->address.iabuf;
1388         options[i].len = lease->address.len;
1389
1390         /* Send the uid if the user supplied one. */
1391         i = DHO_DHCP_CLIENT_IDENTIFIER;
1392         if (config->send_options[i].len) {
1393                 options[i].data = config->send_options[i].data;
1394                 options[i].len = config->send_options[i].len;
1395         }
1396
1397         /* Set up the option buffer to fit in a minimal UDP packet. */
1398         i = cons_options(options);
1399         if (i == -1 || client->packet.options[i] != DHO_END)
1400                 error("options do not fit in DHCPDECLINE packet.");
1401         client->packet_length = DHCP_FIXED_NON_UDP+i+1;
1402         if (client->packet_length < BOOTP_MIN_LEN)
1403                 client->packet_length = BOOTP_MIN_LEN;
1404
1405         client->packet.op = BOOTREQUEST;
1406         client->packet.htype = ifi->hw_address.htype;
1407         client->packet.hlen = ifi->hw_address.hlen;
1408         client->packet.hops = 0;
1409         client->packet.xid = client->xid;
1410         client->packet.secs = 0; /* Filled in by send_request. */
1411         client->packet.flags = 0;
1412
1413         /* ciaddr must always be zero. */
1414         memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr));
1415         memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr));
1416         memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr));
1417         memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr));
1418         memcpy(client->packet.chaddr, ifi->hw_address.haddr,
1419             ifi->hw_address.hlen);
1420 }
1421
1422 void
1423 free_client_lease(struct client_lease *lease)
1424 {
1425         int i;
1426
1427         if (lease->server_name)
1428                 free(lease->server_name);
1429         if (lease->filename)
1430                 free(lease->filename);
1431         for (i = 0; i < 256; i++) {
1432                 if (lease->options[i].len)
1433                         free(lease->options[i].data);
1434         }
1435         free(lease);
1436 }
1437
1438 void
1439 rewrite_client_leases(void)
1440 {
1441         struct client_lease *lp;
1442
1443         if (!leaseFile) /* XXX */
1444                 error("lease file not open");
1445
1446         fflush(leaseFile);
1447         rewind(leaseFile);
1448
1449         for (lp = client->leases; lp; lp = lp->next) {
1450                 if (client->active && addr_eq(lp->address,
1451                         client->active->address))
1452                         continue;
1453                 write_client_lease(lp);
1454         }
1455
1456         if (client->active)
1457                 write_client_lease(client->active);
1458
1459         fflush(leaseFile);
1460         ftruncate(fileno(leaseFile), ftello(leaseFile));
1461         fsync(fileno(leaseFile));
1462 }
1463
1464 void
1465 write_client_lease(struct client_lease *lease)
1466 {
1467         struct tm *t;
1468         int i;
1469
1470         /* If the lease came from the config file, we don't need to stash
1471            a copy in the lease database. */
1472         if (lease->is_static)
1473                 return;
1474
1475         if (!leaseFile) /* XXX */
1476                 error("lease file not open");
1477
1478         fprintf(leaseFile, "lease {\n");
1479         if (lease->is_bootp)
1480                 fprintf(leaseFile, "  bootp;\n");
1481         fprintf(leaseFile, "  interface \"%s\";\n", ifi->name);
1482         fprintf(leaseFile, "  fixed-address %s;\n", piaddr(lease->address));
1483         if (lease->filename)
1484                 fprintf(leaseFile, "  filename \"%s\";\n", lease->filename);
1485         if (lease->server_name)
1486                 fprintf(leaseFile, "  server-name \"%s\";\n",
1487                     lease->server_name);
1488         for (i = 0; i < 256; i++)
1489                 if (lease->options[i].len)
1490                         fprintf(leaseFile, "  option %s %s;\n",
1491                             dhcp_options[i].name,
1492                             pretty_print_option(i, &lease->options[i], 1));
1493
1494         t = gmtime(&lease->renewal);
1495         fprintf(leaseFile, "  renew %d %d/%d/%d %02d:%02d:%02d;\n",
1496             t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1497             t->tm_hour, t->tm_min, t->tm_sec);
1498         t = gmtime(&lease->rebind);
1499         fprintf(leaseFile, "  rebind %d %d/%d/%d %02d:%02d:%02d;\n",
1500             t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1501             t->tm_hour, t->tm_min, t->tm_sec);
1502         t = gmtime(&lease->expiry);
1503         fprintf(leaseFile, "  expire %d %d/%d/%d %02d:%02d:%02d;\n",
1504             t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
1505             t->tm_hour, t->tm_min, t->tm_sec);
1506         fprintf(leaseFile, "}\n");
1507         fflush(leaseFile);
1508 }
1509
1510 void
1511 script_init(char *reason)
1512 {
1513         size_t           len;
1514         struct imsg_hdr  hdr;
1515         struct buf      *buf;
1516
1517         hdr.code = IMSG_SCRIPT_INIT;
1518         hdr.len = sizeof(struct imsg_hdr) + sizeof(size_t) + strlen(reason);
1519         buf = buf_open(hdr.len);
1520
1521         buf_add(buf, &hdr, sizeof(hdr));
1522         len = strlen(reason);
1523         buf_add(buf, &len, sizeof(len));
1524         buf_add(buf, reason, len);
1525
1526         buf_close(privfd, buf);
1527 }
1528
1529 void
1530 priv_script_init(char *reason)
1531 {
1532         client->scriptEnvsize = 100;
1533         if (client->scriptEnv == NULL)
1534                 client->scriptEnv =
1535                     calloc(client->scriptEnvsize, sizeof(char *));
1536         if (client->scriptEnv == NULL)
1537                 error("script_init: no memory for environment");
1538
1539         client->scriptEnv[0] = strdup(CLIENT_PATH);
1540         if (client->scriptEnv[0] == NULL)
1541                 error("script_init: no memory for environment");
1542
1543         client->scriptEnv[1] = NULL;
1544
1545         script_set_env("", "interface", ifi->name);
1546
1547         script_set_env("", "reason", reason);
1548 }
1549
1550 void
1551 priv_script_write_params(char *prefix, struct client_lease *lease)
1552 {
1553         char buf[256];
1554         struct option_data o;
1555         int i;
1556
1557         script_set_env(prefix, "ip_address", piaddr(lease->address));
1558
1559         if (lease->options[DHO_SUBNET_MASK].len &&
1560             (lease->options[DHO_SUBNET_MASK].len <
1561             sizeof(lease->address.iabuf))) {
1562                 struct iaddr netmask, subnet, broadcast;
1563
1564                 memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data,
1565                     lease->options[DHO_SUBNET_MASK].len);
1566                 netmask.len = lease->options[DHO_SUBNET_MASK].len;
1567
1568                 subnet = subnet_number(lease->address, netmask);
1569                 if (subnet.len) {
1570                         script_set_env(prefix, "network_number",
1571                             piaddr(subnet));
1572                         if (!lease->options[DHO_BROADCAST_ADDRESS].len) {
1573                                 broadcast = broadcast_addr(subnet, netmask);
1574                                 if (broadcast.len)
1575                                         script_set_env(prefix,
1576                                             "broadcast_address",
1577                                             piaddr(broadcast));
1578                         }
1579                 }
1580         }
1581
1582         if (lease->filename)
1583                 script_set_env(prefix, "filename", lease->filename);
1584         if (lease->server_name)
1585                 script_set_env(prefix, "server_name",
1586                     lease->server_name);
1587
1588         for (i = 0; i < 256; i++) {
1589                 if (!dhcp_option_ev_name(buf, sizeof(buf), &dhcp_options[i]))
1590                         continue;
1591
1592                 switch (config->default_actions[i]) {
1593                 case ACTION_IGNORE:
1594                          break;
1595
1596                 case ACTION_DEFAULT:
1597                         if (lease->options[i].len)
1598                                 script_set_env(prefix, buf,
1599                                     pretty_print_option(i, &lease->options[i],
1600                                         0));
1601                         else if (config->defaults[i].len)
1602                                 script_set_env(prefix, buf,
1603                                     pretty_print_option(i, &config->defaults[i],
1604                                         0));
1605                         break;
1606
1607                 case ACTION_SUPERSEDE:
1608                         if (config->defaults[i].len)
1609                                 script_set_env(prefix, buf,
1610                                     pretty_print_option(i, &config->defaults[i],
1611                                         0));
1612                         break;
1613
1614                 case ACTION_PREPEND:
1615                         o.len = config->defaults[i].len + lease->options[i].len;
1616                         if (o.len > 0) {
1617                                 o.data = calloc(1, o.len);
1618                                 if (o.data == NULL)
1619                                         error("no space to prepend '%s' to %s",
1620                                             config->defaults[i].data,
1621                                             dhcp_options[i].name);
1622                                 memcpy(o.data, config->defaults[i].data,
1623                                     config->defaults[i].len);
1624                                 memcpy(o.data + config->defaults[i].len,
1625                                     lease->options[i].data,
1626                                     lease->options[i].len);
1627                                 script_set_env(prefix, buf,
1628                                     pretty_print_option(i, &o, 0));
1629                                 free(o.data);
1630                         }
1631                         break;
1632
1633                 case ACTION_APPEND:
1634                         o.len = config->defaults[i].len + lease->options[i].len;
1635                         if (o.len > 0) {
1636                                 o.data = calloc(1, o.len);
1637                                 if (o.data == NULL)
1638                                         error("no space to append '%s' to %s",
1639                                             config->defaults[i].data,
1640                                             dhcp_options[i].name);
1641                                 memcpy(o.data, lease->options[i].data,
1642                                     lease->options[i].len);
1643                                 memcpy(o.data + lease->options[i].len,
1644                                     config->defaults[i].data,
1645                                     config->defaults[i].len);
1646                                 script_set_env(prefix, buf,
1647                                     pretty_print_option(i, &o, 0));
1648                                 free(o.data);
1649                         }
1650                         break;
1651                 }
1652         }
1653
1654         snprintf(buf, sizeof(buf), "%d", (int)lease->expiry);
1655         script_set_env(prefix, "expiry", buf);
1656 }
1657
1658 void
1659 script_write_params(char *prefix, struct client_lease *lease)
1660 {
1661         size_t           fn_len = 0, sn_len = 0, pr_len = 0;
1662         struct imsg_hdr  hdr;
1663         struct buf      *buf;
1664         int              i;
1665
1666         if (lease->filename != NULL)
1667                 fn_len = strlen(lease->filename);
1668         if (lease->server_name != NULL)
1669                 sn_len = strlen(lease->server_name);
1670         if (prefix != NULL)
1671                 pr_len = strlen(prefix);
1672
1673         hdr.code = IMSG_SCRIPT_WRITE_PARAMS;
1674         hdr.len = sizeof(hdr) + sizeof(struct client_lease) +
1675             sizeof(size_t) + fn_len + sizeof(size_t) + sn_len +
1676             sizeof(size_t) + pr_len;
1677
1678         for (i = 0; i < 256; i++)
1679                 hdr.len += sizeof(int) + lease->options[i].len;
1680
1681         scripttime = time(NULL);
1682
1683         buf = buf_open(hdr.len);
1684
1685         buf_add(buf, &hdr, sizeof(hdr));
1686         buf_add(buf, lease, sizeof(struct client_lease));
1687         buf_add(buf, &fn_len, sizeof(fn_len));
1688         buf_add(buf, lease->filename, fn_len);
1689         buf_add(buf, &sn_len, sizeof(sn_len));
1690         buf_add(buf, lease->server_name, sn_len);
1691         buf_add(buf, &pr_len, sizeof(pr_len));
1692         buf_add(buf, prefix, pr_len);
1693
1694         for (i = 0; i < 256; i++) {
1695                 buf_add(buf, &lease->options[i].len,
1696                     sizeof(lease->options[i].len));
1697                 buf_add(buf, lease->options[i].data,
1698                     lease->options[i].len);
1699         }
1700
1701         buf_close(privfd, buf);
1702 }
1703
1704 int
1705 script_go(void)
1706 {
1707         struct imsg_hdr  hdr;
1708         struct buf      *buf;
1709         int              ret;
1710
1711         scripttime = time(NULL);
1712
1713         hdr.code = IMSG_SCRIPT_GO;
1714         hdr.len = sizeof(struct imsg_hdr);
1715
1716         buf = buf_open(hdr.len);
1717
1718         buf_add(buf, &hdr, sizeof(hdr));
1719         buf_close(privfd, buf);
1720
1721         bzero(&hdr, sizeof(hdr));
1722         buf_read(privfd, &hdr, sizeof(hdr));
1723         if (hdr.code != IMSG_SCRIPT_GO_RET)
1724                 error("unexpected msg type %u", hdr.code);
1725         if (hdr.len != sizeof(hdr) + sizeof(int))
1726                 error("received corrupted message");
1727         buf_read(privfd, &ret, sizeof(ret));
1728
1729         return (ret);
1730 }
1731
1732 int
1733 priv_script_go(void)
1734 {
1735         char *scriptName, *argv[2], **envp;
1736         int pid, wpid, wstatus;
1737
1738         scripttime = time(NULL);
1739
1740         scriptName = config->script_name;
1741         envp = client->scriptEnv;
1742
1743         argv[0] = scriptName;
1744         argv[1] = NULL;
1745
1746         pid = fork();
1747         if (pid < 0) {
1748                 error("fork: %m");
1749                 wstatus = 0;
1750         } else if (pid) {
1751                 do {
1752                         wpid = wait(&wstatus);
1753                 } while (wpid != pid && wpid > 0);
1754                 if (wpid < 0) {
1755                         error("wait: %m");
1756                         wstatus = 0;
1757                 }
1758         } else {
1759                 execve(scriptName, argv, envp);
1760                 error("execve (%s, ...): %m", scriptName);
1761         }
1762
1763         script_flush_env();
1764
1765         return (WEXITSTATUS(wstatus));
1766 }
1767
1768 void
1769 script_set_env(const char *prefix, const char *name, const char *value)
1770 {
1771         int i, j, namelen;
1772
1773         /* No `` or $() command substitution allowed in environment values! */
1774         for (j = 0; j < strlen(value); j++)
1775                 switch (value[j]) {
1776                 case '`':
1777                 case '$':
1778                         warning("illegal character (%c) in value '%s'",
1779                             value[j], value);
1780                         /* Ignore this option */
1781                         return;
1782                 }
1783
1784         namelen = strlen(name);
1785
1786         for (i = 0; client->scriptEnv[i]; i++)
1787                 if (strncmp(client->scriptEnv[i], name, namelen) == 0 &&
1788                     client->scriptEnv[i][namelen] == '=')
1789                         break;
1790
1791         if (client->scriptEnv[i])
1792                 /* Reuse the slot. */
1793                 free(client->scriptEnv[i]);
1794         else {
1795                 /* New variable.  Expand if necessary. */
1796                 if (i >= client->scriptEnvsize - 1) {
1797                         char **newscriptEnv;
1798                         int newscriptEnvsize = client->scriptEnvsize + 50;
1799
1800                         newscriptEnv = realloc(client->scriptEnv,
1801                             newscriptEnvsize);
1802                         if (newscriptEnv == NULL) {
1803                                 free(client->scriptEnv);
1804                                 client->scriptEnv = NULL;
1805                                 client->scriptEnvsize = 0;
1806                                 error("script_set_env: no memory for variable");
1807                         }
1808                         client->scriptEnv = newscriptEnv;
1809                         client->scriptEnvsize = newscriptEnvsize;
1810                 }
1811                 /* need to set the NULL pointer at end of array beyond
1812                    the new slot. */
1813                 client->scriptEnv[i + 1] = NULL;
1814         }
1815         /* Allocate space and format the variable in the appropriate slot. */
1816         client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 +
1817             strlen(value) + 1);
1818         if (client->scriptEnv[i] == NULL)
1819                 error("script_set_env: no memory for variable assignment");
1820         snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) +
1821             1 + strlen(value) + 1, "%s%s=%s", prefix, name, value);
1822 }
1823
1824 void
1825 script_flush_env(void)
1826 {
1827         int i;
1828
1829         for (i = 0; client->scriptEnv[i]; i++) {
1830                 free(client->scriptEnv[i]);
1831                 client->scriptEnv[i] = NULL;
1832         }
1833         client->scriptEnvsize = 0;
1834 }
1835
1836 int
1837 dhcp_option_ev_name(char *buf, size_t buflen, const struct option *option)
1838 {
1839         size_t i;
1840
1841         for (i = 0; option->name[i]; i++) {
1842                 if (i + 1 == buflen)
1843                         return 0;
1844                 if (option->name[i] == '-')
1845                         buf[i] = '_';
1846                 else
1847                         buf[i] = option->name[i];
1848         }
1849
1850         buf[i] = 0;
1851         return 1;
1852 }
1853
1854 void
1855 go_daemon(void)
1856 {
1857         char buf[256];
1858         int fd;
1859
1860         /*
1861          * Only once
1862          */
1863         if (no_daemon == 2)
1864                 return;
1865
1866         /*
1867          * Setup pidfile, kill any dhclient already running for this
1868          * interface.
1869          */
1870         snprintf(buf, sizeof(buf), "/var/run/dhclient.%s.pid", orig_ifname);
1871         fd = open(buf, O_RDWR|O_CREAT, 0644);
1872         if (fd >= 0) {
1873                 if (killclient(fd)) {
1874                         fprintf(stderr,
1875                                 "starting dhclient on %s\n",
1876                                 orig_ifname);
1877                 } else {
1878                         fprintf(stderr,
1879                                 "restarting dhclient on %s\n",
1880                                 orig_ifname);
1881                 }
1882         }
1883
1884         /*
1885          * Daemonize if requested
1886          */
1887         if (no_daemon == 0) {
1888                 /* Stop logging to stderr... */
1889                 log_perror = 0;
1890
1891                 if (daemon(1, 0) == -1)
1892                         error("daemon");
1893
1894                 /* we are chrooted, daemon(3) fails to open /dev/null */
1895                 if (nullfd != -1) {
1896                         dup2(nullfd, STDIN_FILENO);
1897                         dup2(nullfd, STDOUT_FILENO);
1898                         dup2(nullfd, STDERR_FILENO);
1899                         close(nullfd);
1900                         nullfd = -1;
1901                 }
1902         }
1903
1904         /*
1905          * No further daemonizations, write out pid file and lock.
1906          */
1907         no_daemon = 2;
1908         if (fd >= 0) {
1909                 lseek(fd, 0L, SEEK_SET);
1910                 ftruncate(fd, 0);
1911                 snprintf(buf, sizeof(buf), "%ld\n", (long)getpid());
1912                 write(fd, buf, strlen(buf));
1913                 flock(fd, LOCK_EX);
1914                 /* leave descriptor open and locked */
1915         }
1916 }
1917
1918 int
1919 check_option(struct client_lease *l, int option)
1920 {
1921         char *opbuf;
1922         char *sbuf;
1923
1924         /* we use this, since this is what gets passed to dhclient-script */
1925
1926         opbuf = pretty_print_option(option, &l->options[option], 0);
1927
1928         sbuf = option_as_string(option, l->options[option].data,
1929             l->options[option].len);
1930
1931         switch (option) {
1932         case DHO_SUBNET_MASK:
1933         case DHO_SWAP_SERVER:
1934         case DHO_BROADCAST_ADDRESS:
1935         case DHO_DHCP_SERVER_IDENTIFIER:
1936         case DHO_ROUTER_SOLICITATION_ADDRESS:
1937         case DHO_DHCP_REQUESTED_ADDRESS:
1938                 if (ipv4addrs(opbuf) == 0) {
1939                         warning("Invalid IP address in option %s: %s",
1940                             dhcp_options[option].name, opbuf);
1941                         return (0);
1942                 }
1943                 if (l->options[option].len != 4) { /* RFC 2132 */
1944                         warning("warning: Only 1 IP address allowed in "
1945                             "%s option; length %d, must be 4",
1946                             dhcp_options[option].name,
1947                             l->options[option].len);
1948                         l->options[option].len = 4;
1949                 }
1950                 return (1);
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_NIS_SERVERS:
1961         case DHO_NTP_SERVERS:
1962         case DHO_NETBIOS_NAME_SERVERS:
1963         case DHO_NETBIOS_DD_SERVER:
1964         case DHO_FONT_SERVERS:
1965                 if (ipv4addrs(opbuf) == 0) {
1966                         warning("Invalid IP address in option %s: %s",
1967                             dhcp_options[option].name, opbuf);
1968                         return (0);
1969                 }
1970                 return (1);
1971         case DHO_HOST_NAME:
1972         case DHO_DOMAIN_NAME:
1973         case DHO_NIS_DOMAIN:
1974                 if (!res_hnok(sbuf)) {
1975                         warning("Bogus Host Name option %d: %s (%s)", option,
1976                             sbuf, opbuf);
1977                         l->options[option].len = 0;
1978                         free(l->options[option].data);
1979                 }
1980                 return (1);
1981         case DHO_PAD:
1982         case DHO_TIME_OFFSET:
1983         case DHO_BOOT_SIZE:
1984         case DHO_MERIT_DUMP:
1985         case DHO_ROOT_PATH:
1986         case DHO_EXTENSIONS_PATH:
1987         case DHO_IP_FORWARDING:
1988         case DHO_NON_LOCAL_SOURCE_ROUTING:
1989         case DHO_POLICY_FILTER:
1990         case DHO_MAX_DGRAM_REASSEMBLY:
1991         case DHO_DEFAULT_IP_TTL:
1992         case DHO_PATH_MTU_AGING_TIMEOUT:
1993         case DHO_PATH_MTU_PLATEAU_TABLE:
1994         case DHO_INTERFACE_MTU:
1995         case DHO_ALL_SUBNETS_LOCAL:
1996         case DHO_PERFORM_MASK_DISCOVERY:
1997         case DHO_MASK_SUPPLIER:
1998         case DHO_ROUTER_DISCOVERY:
1999         case DHO_STATIC_ROUTES:
2000         case DHO_TRAILER_ENCAPSULATION:
2001         case DHO_ARP_CACHE_TIMEOUT:
2002         case DHO_IEEE802_3_ENCAPSULATION:
2003         case DHO_DEFAULT_TCP_TTL:
2004         case DHO_TCP_KEEPALIVE_INTERVAL:
2005         case DHO_TCP_KEEPALIVE_GARBAGE:
2006         case DHO_VENDOR_ENCAPSULATED_OPTIONS:
2007         case DHO_NETBIOS_NODE_TYPE:
2008         case DHO_NETBIOS_SCOPE:
2009         case DHO_X_DISPLAY_MANAGER:
2010         case DHO_DHCP_LEASE_TIME:
2011         case DHO_DHCP_OPTION_OVERLOAD:
2012         case DHO_DHCP_MESSAGE_TYPE:
2013         case DHO_DHCP_PARAMETER_REQUEST_LIST:
2014         case DHO_DHCP_MESSAGE:
2015         case DHO_DHCP_MAX_MESSAGE_SIZE:
2016         case DHO_DHCP_RENEWAL_TIME:
2017         case DHO_DHCP_REBINDING_TIME:
2018         case DHO_DHCP_CLASS_IDENTIFIER:
2019         case DHO_DHCP_CLIENT_IDENTIFIER:
2020         case DHO_DHCP_USER_CLASS_ID:
2021         case DHO_TFTP_SERVER:
2022         case DHO_END:
2023                 return (1);
2024         default:
2025                 if (!unknown_ok)
2026                         warning("unknown dhcp option value 0x%x", option);
2027                 return (unknown_ok);
2028         }
2029 }
2030
2031 int
2032 res_hnok(const char *name)
2033 {
2034         const char *dn = name;
2035         int pch = '.', ch = *dn++;
2036         int warn = 0;
2037
2038         while (ch != '\0') {
2039                 int nch = *dn++;
2040
2041                 if (ch == '.') {
2042                         ;
2043                 } else if (pch == '.' || nch == '.' || nch == '\0') {
2044                         if (!isalnum(ch))
2045                                 return (0);
2046                 } else if (!isalnum(ch) && ch != '-' && ch != '_')
2047                                 return (0);
2048                 else if (ch == '_' && warn == 0) {
2049                         warning("warning: hostname %s contains an "
2050                             "underscore which violates RFC 952", name);
2051                         warn++;
2052                 }
2053                 pch = ch, ch = nch;
2054         }
2055         return (1);
2056 }
2057
2058 /* Does buf consist only of dotted decimal ipv4 addrs?
2059  * return how many if so,
2060  * otherwise, return 0
2061  */
2062 int
2063 ipv4addrs(char * buf)
2064 {
2065         struct in_addr jnk;
2066         int count = 0;
2067
2068         while (inet_aton(buf, &jnk) == 1){
2069                 count++;
2070                 while (*buf == '.' || isdigit(*buf))
2071                         buf++;
2072                 if (*buf == '\0')
2073                         return (count);
2074                 while (*buf ==  ' ')
2075                         buf++;
2076         }
2077         return (0);
2078 }
2079
2080 char *
2081 option_as_string(unsigned int code, unsigned char *data, int len)
2082 {
2083         static char optbuf[32768]; /* XXX */
2084         char *op = optbuf;
2085         int opleft = sizeof(optbuf);
2086         unsigned char *dp = data;
2087
2088         if (code > 255)
2089                 error("option_as_string: bad code %d", code);
2090
2091         for (; dp < data + len; dp++) {
2092                 if (!isascii(*dp) || !isprint(*dp)) {
2093                         if (dp + 1 != data + len || *dp != 0) {
2094                                 size_t oplen;
2095                                 snprintf(op, opleft, "\\%03o", *dp);
2096                                 oplen = strlen(op);
2097                                 op += oplen;
2098                                 opleft -= oplen;
2099                         }
2100                 } else if (*dp == '"' || *dp == '\'' || *dp == '$' ||
2101                     *dp == '`' || *dp == '\\') {
2102                         *op++ = '\\';
2103                         *op++ = *dp;
2104                         opleft -= 2;
2105                 } else {
2106                         *op++ = *dp;
2107                         opleft--;
2108                 }
2109         }
2110         if (opleft < 1)
2111                 goto toobig;
2112         *op = 0;
2113         return optbuf;
2114 toobig:
2115         warning("dhcp option too large");
2116         return "<error>";
2117 }
2118
2119 int
2120 fork_privchld(int fd, int fd2)
2121 {
2122         struct pollfd pfd[1];
2123         int nfds, pfail = 0;
2124         pid_t pid;
2125         int omask;
2126
2127         omask = sigblock(sigmask(SIGINT)|sigmask(SIGHUP));
2128         pid = fork();
2129         if (pid > 0)
2130                 monitor_pid = pid;
2131         sigsetmask(omask);
2132
2133         switch (pid) {
2134         case -1:
2135                 error("cannot fork");
2136                 break;
2137         case 0:
2138                 break;
2139         default:
2140                 return (0);
2141         }
2142
2143         if (chdir("/") == -1)
2144                 error("chdir(\"/\")");
2145
2146         setproctitle("%s [priv]", ifi->name);
2147
2148         dup2(nullfd, STDIN_FILENO);
2149         dup2(nullfd, STDOUT_FILENO);
2150         dup2(nullfd, STDERR_FILENO);
2151         close(nullfd);
2152         close(fd2);
2153
2154         for (;;) {
2155                 pfd[0].fd = fd;
2156                 pfd[0].events = POLLIN;
2157                 if ((nfds = poll(pfd, 1, INFTIM)) == -1)
2158                         if (errno != EINTR)
2159                                 error("poll error");
2160
2161                 /*
2162                  * Handle temporary errors, but bail if they persist.
2163                  */
2164                 if (nfds == 0 || !(pfd[0].revents & POLLIN)) {
2165                         if (pfail > POLL_FAILURES)
2166                                 error("poll failed > %d times", POLL_FAILURES);
2167                         sleep(pfail * POLL_FAILURE_WAIT);
2168                         pfail++;
2169                         continue;
2170                 }
2171
2172                 dispatch_imsg(fd);
2173         }
2174 }
2175
2176 void
2177 get_ifname(char *ifname, char *arg)
2178 {
2179         struct ifgroupreq ifgr;
2180         struct ifg_req *ifg;
2181         int s, len;
2182
2183         if (!strcmp(arg, "egress")) {
2184                 s = socket(AF_INET, SOCK_DGRAM, 0);
2185                 if (s == -1)
2186                         error("socket error");
2187                 bzero(&ifgr, sizeof(ifgr));
2188                 strlcpy(ifgr.ifgr_name, "egress", sizeof(ifgr.ifgr_name));
2189                 if (ioctl(s, SIOCGIFGMEMB, (caddr_t)&ifgr) == -1) {
2190                         if (errno == ENOENT)
2191                                 error("no interface in group egress found");
2192                         error("ioctl SIOCGIFGMEMB: %m");
2193                 }
2194                 len = ifgr.ifgr_len;
2195                 if ((ifgr.ifgr_groups = calloc(1, len)) == NULL)
2196                         error("get_ifname");
2197                 if (ioctl(s, SIOCGIFGMEMB, (caddr_t)&ifgr) == -1)
2198                         error("ioctl SIOCGIFGMEMB: %m");
2199
2200                 arg = NULL;
2201                 for (ifg = ifgr.ifgr_groups;
2202                      ifg && len >= sizeof(struct ifg_req); ifg++) {
2203                         len -= sizeof(struct ifg_req);
2204                         if (arg)
2205                                 error("too many interfaces in group egress");
2206                         arg = ifg->ifgrq_member;
2207                 }
2208
2209                 if (strlcpy(ifi->name, arg, IFNAMSIZ) >= IFNAMSIZ)
2210                         error("Interface name too long: %m");
2211
2212                 free(ifgr.ifgr_groups);
2213                 close(s);
2214         } else if (strlcpy(ifi->name, arg, IFNAMSIZ) >= IFNAMSIZ)
2215                 error("Interface name too long");
2216 }
2217
2218 static
2219 void
2220 sig_handle(int signo)
2221 {
2222         if (monitor_pid > 0)
2223                 kill(monitor_pid, signo);
2224         fprintf(stderr, "killed by signal\n");
2225         exit(1);
2226 }
2227
2228 static
2229 int
2230 killclient(int fd)
2231 {
2232         int noclient = 1;
2233
2234         /*
2235          * Kill previously running dhclient
2236          */
2237         if (flock(fd, LOCK_EX|LOCK_NB) < 0) {
2238                 char buf[256];
2239                 ssize_t n;
2240                 pid_t pid;
2241
2242                 lseek(fd, 0L, SEEK_SET);
2243                 n = read(fd, buf, sizeof(buf));
2244                 if (n > 0) {
2245                         buf[n-1] = 0;
2246                         pid = strtol(buf, NULL, 10);
2247                         if ((int)pid > 0) {
2248                                 noclient = 0;
2249                                 kill(pid, SIGINT);
2250                         }
2251                 }
2252                 if (flock(fd, LOCK_EX|LOCK_NB) < 0)
2253                         usleep(20000);
2254                 while (flock(fd, LOCK_EX|LOCK_NB) < 0)
2255                         sleep(1);
2256         }
2257         return noclient;
2258 }