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 check_classless_option(unsigned char *data, int len); 96 int ipv4addrs(char * buf); 97 int res_hnok(const char *dn); 98 char *option_as_string(unsigned int code, unsigned char *data, int len); 99 int fork_privchld(int, int); 100 void get_ifname(char *, char *); 101 static void sig_handle(int sig); 102 static int killclient(int fd); 103 104 time_t scripttime; 105 static FILE *leaseFile; 106 107 int 108 findproto(char *cp, int n) 109 { 110 struct sockaddr *sa; 111 int i; 112 113 if (n == 0) 114 return -1; 115 for (i = 1; i; i <<= 1) { 116 if (i & n) { 117 sa = (struct sockaddr *)cp; 118 switch (i) { 119 case RTA_IFA: 120 case RTA_DST: 121 case RTA_GATEWAY: 122 case RTA_NETMASK: 123 if (sa->sa_family == AF_INET) 124 return AF_INET; 125 if (sa->sa_family == AF_INET6) 126 return AF_INET6; 127 break; 128 case RTA_IFP: 129 break; 130 } 131 RT_ADVANCE(cp, sa); 132 } 133 } 134 return (-1); 135 } 136 137 struct sockaddr * 138 get_ifa(char *cp, int n) 139 { 140 struct sockaddr *sa; 141 int i; 142 143 if (n == 0) 144 return (NULL); 145 for (i = 1; i; i <<= 1) 146 if (i & n) { 147 sa = (struct sockaddr *)cp; 148 if (i == RTA_IFA) 149 return (sa); 150 RT_ADVANCE(cp, sa); 151 } 152 153 return (NULL); 154 } 155 struct iaddr defaddr = { .len = 4 }; /* NULL is for silence warnings */ 156 157 void 158 routehandler(void) 159 { 160 int linkstat; 161 char msg[2048]; 162 struct rt_msghdr *rtm; 163 struct if_msghdr *ifm; 164 struct ifa_msghdr *ifam; 165 struct if_announcemsghdr *ifan; 166 struct client_lease *l; 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 /* state_panic() can try unexpired existing leases */ 201 if (client->active && addr_eq(a, client->active->address)) 202 break; 203 for (l = client->leases; l != NULL; l = l->next) 204 if (addr_eq(a, l->address)) 205 break; 206 207 if (l != NULL) 208 /* new addr is the one we set */ 209 break; 210 snprintf(buf, sizeof(buf), "%s: %s", 211 "new address not one we set", piaddr(a)); 212 errmsg = buf; 213 goto die; 214 case RTM_DELADDR: 215 ifam = (struct ifa_msghdr *)rtm; 216 if (ifam->ifam_index != ifi->index) 217 break; 218 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET) 219 break; 220 /* XXX check addrs like RTM_NEWADDR instead of this? */ 221 if (scripttime == 0 || time(NULL) < scripttime + 10) 222 break; 223 errmsg = "interface address deleted"; 224 goto die; 225 case RTM_IFINFO: 226 ifm = (struct if_msghdr *)rtm; 227 if (ifm->ifm_index != ifi->index) 228 break; 229 if ((rtm->rtm_flags & RTF_UP) == 0) { 230 errmsg = "interface down"; 231 goto die; 232 } 233 234 linkstat = 235 LINK_STATE_IS_UP(ifm->ifm_data.ifi_link_state) ? 1 : 0; 236 if (linkstat != ifi->linkstat) { 237 #ifdef DEBUG 238 debug("link state %s -> %s", 239 ifi->linkstat ? "up" : "down", 240 linkstat ? "up" : "down"); 241 #endif 242 ifi->linkstat = interface_status(ifi->name); 243 if (ifi->linkstat) { 244 client->state = S_REBOOTING; 245 state_reboot(); 246 } 247 } 248 break; 249 case RTM_IFANNOUNCE: 250 ifan = (struct if_announcemsghdr *)rtm; 251 if (ifan->ifan_what == IFAN_DEPARTURE && 252 ifan->ifan_index == ifi->index) { 253 errmsg = "interface departure"; 254 goto die; 255 } 256 break; 257 default: 258 break; 259 } 260 return; 261 262 die: 263 script_init("FAIL"); 264 script_go(); 265 error("routehandler: %s", errmsg); 266 } 267 268 int 269 main(int argc, char *argv[]) 270 { 271 int ch, fd; 272 int pipe_fd[2]; 273 int quiet = 0; 274 int dokillclient = 0; 275 int i; 276 struct passwd *pw; 277 278 /* Initially, log errors to stderr as well as to syslogd. */ 279 openlog(getprogname(), LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY); 280 setlogmask(LOG_UPTO(LOG_INFO)); 281 282 signal(SIGINT, sig_handle); 283 signal(SIGHUP, sig_handle); 284 285 while ((ch = getopt(argc, argv, "c:dl:quwx")) != -1) { 286 switch (ch) { 287 case 'c': 288 path_dhclient_conf = optarg; 289 break; 290 case 'd': 291 no_daemon = 1; 292 break; 293 case 'l': 294 path_dhclient_db = optarg; 295 break; 296 case 'q': 297 quiet = 1; 298 break; 299 case 'u': 300 unknown_ok = 0; 301 break; 302 case 'w': 303 stayalive = 1; 304 break; 305 case 'x': 306 dokillclient = 1; 307 break; 308 default: 309 usage(); 310 } 311 } 312 313 argc -= optind; 314 argv += optind; 315 316 if (argc != 1) 317 usage(); 318 orig_ifname = argv[0]; 319 320 if (dokillclient) { 321 char buf[256]; 322 323 snprintf(buf, sizeof(buf), 324 "/var/run/dhclient.%s.pid", orig_ifname); 325 fd = open(buf, O_RDWR, 0644); 326 if (fd < 0 || killclient(fd)) { 327 fprintf(stderr, 328 "no dhclient running on %s\n", 329 orig_ifname); 330 } else { 331 fprintf(stderr, 332 "stopping dhclient on %s\n", 333 orig_ifname); 334 } 335 if (fd >= 0) 336 close(fd); 337 exit(1); 338 } 339 340 if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1) 341 error("cannot open %s: %m", _PATH_DEVNULL); 342 343 /* 344 * If asked to stay alive forever get our daemon going right now 345 * Then set up to fork/monitor and refork on exit. 346 * 347 * When I say 'forever' I really mean it. If there are configuration 348 * problems or missing interfaces or whatever, dhclient will wait 349 * 10 seconds and try again. 350 */ 351 if (stayalive) { 352 pid_t pid; 353 pid_t rpid; 354 int omask; 355 356 go_daemon(); 357 358 for (;;) { 359 omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP)); 360 pid = fork(); 361 if (pid > 0) 362 monitor_pid = pid; 363 sigsetmask(omask); 364 365 if (pid == 0) /* child falls out of loop */ 366 break; 367 while (pid > 0) { 368 rpid = waitpid(pid, NULL, 0); 369 if (rpid == pid) 370 break; 371 if (rpid != EINTR) 372 break; 373 } 374 sleep(10); 375 } 376 } 377 378 ifi = calloc(1, sizeof(*ifi)); 379 if (ifi == NULL) 380 error("ifi calloc"); 381 client = calloc(1, sizeof(*client)); 382 if (client == NULL) 383 error("client calloc"); 384 config = calloc(1, sizeof(*config)); 385 if (config == NULL) 386 error("config calloc"); 387 388 get_ifname(ifi->name, argv[0]); 389 390 if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s", 391 _PATH_DHCLIENT_DB, ifi->name) == -1) 392 error("asprintf"); 393 394 if (quiet) 395 log_perror = 0; 396 397 tzset(); 398 399 memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast)); 400 sockaddr_broadcast.sin_family = AF_INET; 401 sockaddr_broadcast.sin_port = htons(REMOTE_PORT); 402 sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST; 403 sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast); 404 inaddr_any.s_addr = INADDR_ANY; 405 406 read_client_conf(); 407 408 if (interface_status(ifi->name) == 0) { 409 interface_link_forceup(ifi->name); 410 /* Give it up to 4 seconds of silent grace to find link */ 411 i = -4; 412 } else { 413 i = 0; 414 } 415 416 while (!(ifi->linkstat = interface_status(ifi->name))) { 417 if (i == 0) 418 fprintf(stderr, "%s: no link ...", ifi->name); 419 else if (i > 0) 420 fprintf(stderr, "."); 421 fflush(stderr); 422 if (++i > config->link_timeout) { 423 fprintf(stderr, " sleeping\n"); 424 goto dispatch; 425 } 426 sleep(1); 427 } 428 if (i > 0) 429 fprintf(stderr, " got link\n"); 430 431 dispatch: 432 if ((pw = getpwnam("_dhcp")) == NULL) 433 error("no such user: _dhcp"); 434 435 if (pipe(pipe_fd) == -1) 436 error("pipe"); 437 438 go_daemon(); 439 fork_privchld(pipe_fd[0], pipe_fd[1]); 440 441 close(pipe_fd[0]); 442 privfd = pipe_fd[1]; 443 444 if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1) 445 error("can't open and lock %s: %m", path_dhclient_db); 446 read_client_leases(); 447 if ((leaseFile = fopen(path_dhclient_db, "w")) == NULL) 448 error("can't open %s: %m", path_dhclient_db); 449 rewrite_client_leases(); 450 close(fd); 451 452 if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1) 453 error("socket(PF_ROUTE, SOCK_RAW): %m"); 454 455 /* set up the interface */ 456 discover_interface(); 457 458 if (chroot(_PATH_VAREMPTY) == -1) 459 error("chroot"); 460 if (chdir("/") == -1) 461 error("chdir(\"/\")"); 462 463 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) 464 error("setresgid"); 465 if (setgroups(1, &pw->pw_gid) == -1) 466 error("setgroups"); 467 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) 468 error("setresuid"); 469 470 endpwent(); 471 472 setproctitle("%s", ifi->name); 473 474 if (ifi->linkstat) { 475 client->state = S_REBOOTING; 476 state_reboot(); 477 } 478 dispatch(); 479 480 /* not reached */ 481 return (0); 482 } 483 484 void 485 usage(void) 486 { 487 fprintf(stderr, "usage: %s [-dqu] [-c file] [-l file] interface\n", 488 getprogname()); 489 exit(1); 490 } 491 492 /* 493 * Individual States: 494 * 495 * Each routine is called from the dhclient_state_machine() in one of 496 * these conditions: 497 * -> entering INIT state 498 * -> recvpacket_flag == 0: timeout in this state 499 * -> otherwise: received a packet in this state 500 * 501 * Return conditions as handled by dhclient_state_machine(): 502 * Returns 1, sendpacket_flag = 1: send packet, reset timer. 503 * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone). 504 * Returns 0: finish the nap which was interrupted for no good reason. 505 * 506 * Several per-interface variables are used to keep track of the process: 507 * active_lease: the lease that is being used on the interface 508 * (null pointer if not configured yet). 509 * offered_leases: leases corresponding to DHCPOFFER messages that have 510 * been sent to us by DHCP servers. 511 * acked_leases: leases corresponding to DHCPACK messages that have been 512 * sent to us by DHCP servers. 513 * sendpacket: DHCP packet we're trying to send. 514 * destination: IP address to send sendpacket to 515 * In addition, there are several relevant per-lease variables. 516 * T1_expiry, T2_expiry, lease_expiry: lease milestones 517 * In the active lease, these control the process of renewing the lease; 518 * In leases on the acked_leases list, this simply determines when we 519 * can no longer legitimately use the lease. 520 */ 521 void 522 state_reboot(void) 523 { 524 /* Cancel all timeouts, since a link state change gets us here 525 and can happen anytime. */ 526 cancel_timeout(); 527 528 /* If we don't remember an active lease, go straight to INIT. */ 529 if (!client->active || client->active->is_bootp) { 530 client->state = S_INIT; 531 state_init(); 532 return; 533 } 534 535 /* make_request doesn't initialize xid because it normally comes 536 from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER, 537 so pick an xid now. */ 538 client->xid = arc4random(); 539 540 /* Make a DHCPREQUEST packet, and set appropriate per-interface 541 flags. */ 542 make_request(client->active); 543 client->destination = iaddr_broadcast; 544 client->first_sending = time(NULL); 545 client->interval = 0; 546 547 send_request(); 548 } 549 550 /* 551 * Called when a lease has completely expired and we've 552 * been unable to renew it. 553 */ 554 void 555 state_init(void) 556 { 557 /* Make a DHCPDISCOVER packet, and set appropriate per-interface 558 flags. */ 559 make_discover(client->active); 560 client->xid = client->packet.xid; 561 client->destination = iaddr_broadcast; 562 client->state = S_SELECTING; 563 client->first_sending = time(NULL); 564 client->interval = 0; 565 566 send_discover(); 567 } 568 569 /* 570 * state_selecting is called when one or more DHCPOFFER packets 571 * have been received and a configurable period of time has passed. 572 */ 573 void 574 state_selecting(void) 575 { 576 struct client_lease *lp, *next, *picked; 577 time_t cur_time; 578 579 /* Cancel state_selecting and send_discover timeouts, since either 580 one could have got us here. */ 581 cancel_timeout(); 582 583 /* We have received one or more DHCPOFFER packets. Currently, 584 the only criterion by which we judge leases is whether or 585 not we get a response when we arp for them. */ 586 picked = NULL; 587 for (lp = client->offered_leases; lp; lp = next) { 588 next = lp->next; 589 590 if (!picked) { 591 picked = lp; 592 } else { 593 make_decline(lp); 594 send_decline(); 595 free_client_lease(lp); 596 } 597 } 598 client->offered_leases = NULL; 599 600 /* If we just tossed all the leases we were offered, go back 601 to square one. */ 602 if (!picked) { 603 client->state = S_INIT; 604 state_init(); 605 return; 606 } 607 picked->next = NULL; 608 609 time(&cur_time); 610 611 /* If it was a BOOTREPLY, we can just take the address right now. */ 612 if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) { 613 client->new = picked; 614 615 /* Make up some lease expiry times 616 XXX these should be configurable. */ 617 client->new->expiry = cur_time + 12000; 618 client->new->renewal += cur_time + 8000; 619 client->new->rebind += cur_time + 10000; 620 621 client->state = S_REQUESTING; 622 623 /* Bind to the address we received. */ 624 bind_lease(); 625 return; 626 } 627 628 /* Go to the REQUESTING state. */ 629 client->destination = iaddr_broadcast; 630 client->state = S_REQUESTING; 631 client->first_sending = cur_time; 632 client->interval = 0; 633 634 /* Make a DHCPREQUEST packet from the lease we picked. */ 635 make_request(picked); 636 client->xid = client->packet.xid; 637 638 /* Toss the lease we picked - we'll get it back in a DHCPACK. */ 639 free_client_lease(picked); 640 641 send_request(); 642 } 643 644 void 645 dhcpack(struct iaddr client_addr, struct option_data *options) 646 { 647 struct client_lease *lease; 648 time_t cur_time; 649 650 651 if (client->state != S_REBOOTING && 652 client->state != S_REQUESTING && 653 client->state != S_RENEWING && 654 client->state != S_REBINDING) 655 return; 656 657 658 lease = packet_to_lease(options); 659 if (!lease) { 660 note("packet_to_lease failed."); 661 return; 662 } 663 664 client->new = lease; 665 666 /* Stop resending DHCPREQUEST. */ 667 cancel_timeout(); 668 669 /* Figure out the lease time. */ 670 if (client->new->options[DHO_DHCP_LEASE_TIME].data) 671 client->new->expiry = 672 getULong(client->new->options[DHO_DHCP_LEASE_TIME].data); 673 else 674 client->new->expiry = DEFAULT_LEASE_TIME; 675 /* A number that looks negative here is really just very large, 676 because the lease expiry offset is unsigned. */ 677 if (client->new->expiry < 0) 678 client->new->expiry = TIME_MAX; 679 /* XXX should be fixed by resetting the client state */ 680 if (client->new->expiry < 60) 681 client->new->expiry = 60; 682 683 /* Take the server-provided renewal time if there is one; 684 otherwise figure it out according to the spec. */ 685 if (client->new->options[DHO_DHCP_RENEWAL_TIME].len) 686 client->new->renewal = 687 getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data); 688 else 689 client->new->renewal = client->new->expiry / 2; 690 691 /* Same deal with the rebind time. */ 692 if (client->new->options[DHO_DHCP_REBINDING_TIME].len) 693 client->new->rebind = 694 getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data); 695 else 696 client->new->rebind = client->new->renewal + 697 client->new->renewal / 2 + client->new->renewal / 4; 698 699 time(&cur_time); 700 701 client->new->expiry += cur_time; 702 /* Lease lengths can never be negative. */ 703 if (client->new->expiry < cur_time) 704 client->new->expiry = TIME_MAX; 705 client->new->renewal += cur_time; 706 if (client->new->renewal < cur_time) 707 client->new->renewal = TIME_MAX; 708 client->new->rebind += cur_time; 709 if (client->new->rebind < cur_time) 710 client->new->rebind = TIME_MAX; 711 712 bind_lease(); 713 } 714 715 void 716 bind_lease(void) 717 { 718 /* Run the client script with the new parameters. */ 719 script_init((client->state == S_REQUESTING ? "BOUND" : 720 (client->state == S_RENEWING ? "RENEW" : 721 (client->state == S_REBOOTING ? "REBOOT" : "REBIND")))); 722 if (client->active && client->state != S_REBOOTING) 723 script_write_params("old_", client->active); 724 script_write_params("new_", client->new); 725 script_go(); 726 727 /* Replace the old active lease with the new one. */ 728 if (client->active) 729 free_client_lease(client->active); 730 client->active = client->new; 731 client->new = NULL; 732 733 /* Write out new leases file. */ 734 rewrite_client_leases(); 735 736 /* Set timeout to start the renewal process. */ 737 set_timeout(client->active->renewal, state_bound); 738 739 note("bound to %s -- renewal in %lld seconds.", 740 piaddr(client->active->address), 741 (long long)(client->active->renewal - time(NULL))); 742 client->state = S_BOUND; 743 } 744 745 /* 746 * state_bound is called when we've successfully bound to a particular 747 * lease, but the renewal time on that lease has expired. We are 748 * expected to unicast a DHCPREQUEST to the server that gave us our 749 * original lease. 750 */ 751 void 752 state_bound(void) 753 { 754 /* T1 has expired. */ 755 make_request(client->active); 756 client->xid = client->packet.xid; 757 758 if (client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) { 759 memcpy(client->destination.iabuf, 760 client->active->options[DHO_DHCP_SERVER_IDENTIFIER].data, 761 4); 762 client->destination.len = 4; 763 } else 764 client->destination = iaddr_broadcast; 765 766 client->first_sending = time(NULL); 767 client->interval = 0; 768 client->state = S_RENEWING; 769 770 send_request(); 771 } 772 773 void 774 dhcpoffer(struct iaddr client_addr, struct option_data *options) 775 { 776 struct client_lease *lease, *lp; 777 int i; 778 time_t stop_selecting; 779 char *name = options[DHO_DHCP_MESSAGE_TYPE].len ? "DHCPOFFER" : 780 "BOOTREPLY"; 781 782 783 if (client->state != S_SELECTING) 784 return; 785 786 787 /* If this lease doesn't supply the minimum required parameters, 788 blow it off. */ 789 for (i = 0; config->required_options[i]; i++) { 790 if (!options[config->required_options[i]].len) { 791 note("%s isn't satisfactory.", name); 792 return; 793 } 794 } 795 796 /* If we've already seen this lease, don't record it again. */ 797 for (lease = client->offered_leases; 798 lease; lease = lease->next) { 799 if (lease->address.len == sizeof(client->packet.yiaddr) && 800 !memcmp(lease->address.iabuf, 801 &client->packet.yiaddr, lease->address.len)) { 802 #ifdef DEBUG 803 debug("%s already seen.", name); 804 #endif 805 return; 806 } 807 } 808 809 lease = packet_to_lease(options); 810 if (!lease) { 811 note("packet_to_lease failed."); 812 return; 813 } 814 815 /* 816 * Reject offers whose subnet is already configured on another 817 * interface. 818 */ 819 if (subnet_exists(lease)) 820 return; 821 822 /* If this lease was acquired through a BOOTREPLY, record that 823 fact. */ 824 if (!options[DHO_DHCP_MESSAGE_TYPE].len) 825 lease->is_bootp = 1; 826 827 /* Figure out when we're supposed to stop selecting. */ 828 stop_selecting = client->first_sending + config->select_interval; 829 830 /* If this is the lease we asked for, put it at the head of the 831 list, and don't mess with the arp request timeout. */ 832 if (addr_eq(lease->address, client->requested_address)) { 833 lease->next = client->offered_leases; 834 client->offered_leases = lease; 835 } else { 836 /* Put the lease at the end of the list. */ 837 lease->next = NULL; 838 if (!client->offered_leases) 839 client->offered_leases = lease; 840 else { 841 for (lp = client->offered_leases; lp->next; 842 lp = lp->next) 843 ; /* nothing */ 844 lp->next = lease; 845 } 846 } 847 848 /* If the selecting interval has expired, go immediately to 849 state_selecting(). Otherwise, time out into 850 state_selecting at the select interval. */ 851 if (stop_selecting <= time(NULL)) 852 state_selecting(); 853 else { 854 set_timeout(stop_selecting, state_selecting); 855 } 856 } 857 858 /* 859 * Allocate a client_lease structure and initialize it from the 860 * parameters in the specified packet. 861 */ 862 struct client_lease * 863 packet_to_lease(struct option_data *options) 864 { 865 struct client_lease *lease; 866 int i; 867 868 lease = malloc(sizeof(struct client_lease)); 869 870 if (!lease) { 871 warning("dhcpoffer: no memory to record lease."); 872 return (NULL); 873 } 874 875 memset(lease, 0, sizeof(*lease)); 876 877 /* Copy the lease options. */ 878 for (i = 0; i < 256; i++) { 879 if (options[i].len) { 880 lease->options[i] = options[i]; 881 options[i].data = NULL; 882 options[i].len = 0; 883 if (!check_option(lease, i)) { 884 warning("Invalid lease option - ignoring offer"); 885 free_client_lease(lease); 886 return (NULL); 887 } 888 } 889 } 890 891 lease->address.len = sizeof(client->packet.yiaddr); 892 memcpy(lease->address.iabuf, &client->packet.yiaddr, 893 lease->address.len); 894 895 /* If the server name was filled out, copy it. */ 896 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len || 897 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) && 898 client->packet.sname[0]) { 899 lease->server_name = malloc(DHCP_SNAME_LEN + 1); 900 if (!lease->server_name) { 901 warning("dhcpoffer: no memory for server name."); 902 free_client_lease(lease); 903 return (NULL); 904 } 905 memcpy(lease->server_name, client->packet.sname, 906 DHCP_SNAME_LEN); 907 lease->server_name[DHCP_SNAME_LEN] = '\0'; 908 if (!res_hnok(lease->server_name)) { 909 warning("Bogus server name %s", lease->server_name); 910 free(lease->server_name); 911 lease->server_name = NULL; 912 } 913 } 914 915 /* Ditto for the filename. */ 916 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len || 917 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) && 918 client->packet.file[0]) { 919 /* Don't count on the NUL terminator. */ 920 lease->filename = malloc(DHCP_FILE_LEN + 1); 921 if (!lease->filename) { 922 warning("dhcpoffer: no memory for filename."); 923 free_client_lease(lease); 924 return (NULL); 925 } 926 memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN); 927 lease->filename[DHCP_FILE_LEN] = '\0'; 928 } 929 return lease; 930 } 931 932 void 933 dhcpnak(struct iaddr client_addr, struct option_data *options) 934 { 935 936 if (client->state != S_REBOOTING && 937 client->state != S_REQUESTING && 938 client->state != S_RENEWING && 939 client->state != S_REBINDING) 940 return; 941 942 943 if (!client->active) { 944 note("DHCPNAK with no active lease."); 945 return; 946 } 947 948 free_client_lease(client->active); 949 client->active = NULL; 950 951 /* Stop sending DHCPREQUEST packets... */ 952 cancel_timeout(); 953 954 client->state = S_INIT; 955 state_init(); 956 } 957 958 /* 959 * Send out a DHCPDISCOVER packet, and set a timeout to send out another 960 * one after the right interval has expired. If we don't get an offer by 961 * the time we reach the panic interval, call the panic function. 962 */ 963 void 964 send_discover(void) 965 { 966 time_t cur_time; 967 int interval, increase = 1; 968 969 time(&cur_time); 970 971 /* Figure out how long it's been since we started transmitting. */ 972 interval = cur_time - client->first_sending; 973 974 /* If we're past the panic timeout, call the script and tell it 975 we haven't found anything for this interface yet. */ 976 if (interval > config->timeout) { 977 state_panic(); 978 return; 979 } 980 981 /* 982 * If we're supposed to increase the interval, do so. If it's 983 * currently zero (i.e., we haven't sent any packets yet), set 984 * it to initial_interval; otherwise, add to it a random 985 * number between zero and two times itself. On average, this 986 * means that it will double with every transmission. 987 */ 988 if (increase) { 989 if (!client->interval) 990 client->interval = config->initial_interval; 991 else { 992 client->interval += (arc4random() >> 2) % 993 (2 * client->interval); 994 } 995 996 /* Don't backoff past cutoff. */ 997 if (client->interval > config->backoff_cutoff) 998 client->interval = ((config->backoff_cutoff / 2) 999 + ((arc4random() >> 2) % 1000 config->backoff_cutoff)); 1001 } else if (!client->interval) 1002 client->interval = config->initial_interval; 1003 1004 /* If the backoff would take us to the panic timeout, just use that 1005 as the interval. */ 1006 if (cur_time + client->interval > 1007 client->first_sending + config->timeout) 1008 client->interval = (client->first_sending + 1009 config->timeout) - cur_time + 1; 1010 1011 /* Record the number of seconds since we started sending. */ 1012 if (interval < 65536) 1013 client->packet.secs = htons(interval); 1014 else 1015 client->packet.secs = htons(65535); 1016 client->secs = client->packet.secs; 1017 1018 note("DHCPDISCOVER on %s to %s port %d interval %ld", 1019 ifi->name, inet_ntoa(sockaddr_broadcast.sin_addr), 1020 ntohs(sockaddr_broadcast.sin_port), client->interval); 1021 1022 send_packet(inaddr_any, &sockaddr_broadcast, NULL); 1023 1024 set_timeout_interval(client->interval, send_discover); 1025 } 1026 1027 /* 1028 * state_panic gets called if we haven't received any offers in a preset 1029 * amount of time. When this happens, we try to use existing leases 1030 * that haven't yet expired, and failing that, we call the client script 1031 * and hope it can do something. 1032 */ 1033 void 1034 state_panic(void) 1035 { 1036 struct client_lease *loop = client->active; 1037 struct client_lease *lp; 1038 time_t cur_time; 1039 1040 note("No DHCPOFFERS received."); 1041 1042 /* We may not have an active lease, but we may have some 1043 predefined leases that we can try. */ 1044 if (!client->active && client->leases) 1045 goto activate_next; 1046 1047 /* Run through the list of leases and see if one can be used. */ 1048 time(&cur_time); 1049 while (client->active) { 1050 if (client->active->expiry > cur_time) { 1051 note("Trying recorded lease %s", 1052 piaddr(client->active->address)); 1053 /* Run the client script with the existing 1054 parameters. */ 1055 script_init("TIMEOUT"); 1056 script_write_params("new_", client->active); 1057 1058 /* If the old lease is still good and doesn't 1059 yet need renewal, go into BOUND state and 1060 timeout at the renewal time. */ 1061 if (!script_go()) { 1062 if (cur_time < client->active->renewal) { 1063 client->state = S_BOUND; 1064 note("bound: renewal in %lld seconds.", 1065 (long long)(client->active->renewal 1066 - cur_time)); 1067 set_timeout(client->active->renewal, 1068 state_bound); 1069 } else { 1070 client->state = S_BOUND; 1071 note("bound: immediate renewal."); 1072 state_bound(); 1073 } 1074 return; 1075 } 1076 } 1077 1078 /* If there are no other leases, give up. */ 1079 if (!client->leases) { 1080 client->leases = client->active; 1081 client->active = NULL; 1082 break; 1083 } 1084 1085 activate_next: 1086 /* Otherwise, put the active lease at the end of the 1087 lease list, and try another lease.. */ 1088 for (lp = client->leases; lp->next; lp = lp->next) 1089 ; 1090 lp->next = client->active; 1091 if (lp->next) 1092 lp->next->next = NULL; 1093 client->active = client->leases; 1094 client->leases = client->leases->next; 1095 1096 /* If we already tried this lease, we've exhausted the 1097 set of leases, so we might as well give up for 1098 now. */ 1099 if (client->active == loop) 1100 break; 1101 else if (!loop) 1102 loop = client->active; 1103 } 1104 1105 /* No leases were available, or what was available didn't work, so 1106 tell the shell script that we failed to allocate an address, 1107 and try again later. */ 1108 note("No working leases in persistent database - sleeping."); 1109 script_init("FAIL"); 1110 script_go(); 1111 client->state = S_INIT; 1112 set_timeout_interval(config->retry_interval, state_init); 1113 } 1114 1115 void 1116 send_request(void) 1117 { 1118 struct sockaddr_in destination; 1119 struct in_addr from; 1120 time_t cur_time; 1121 int interval; 1122 1123 time(&cur_time); 1124 1125 /* Figure out how long it's been since we started transmitting. */ 1126 interval = (int)(cur_time - client->first_sending); 1127 1128 /* If we're in the INIT-REBOOT or REQUESTING state and we're 1129 past the reboot timeout, go to INIT and see if we can 1130 DISCOVER an address... */ 1131 /* XXX In the INIT-REBOOT state, if we don't get an ACK, it 1132 means either that we're on a network with no DHCP server, 1133 or that our server is down. In the latter case, assuming 1134 that there is a backup DHCP server, DHCPDISCOVER will get 1135 us a new address, but we could also have successfully 1136 reused our old address. In the former case, we're hosed 1137 anyway. This is not a win-prone situation. */ 1138 if ((client->state == S_REBOOTING || 1139 client->state == S_REQUESTING) && 1140 interval > config->reboot_timeout) { 1141 client->state = S_INIT; 1142 cancel_timeout(); 1143 state_init(); 1144 return; 1145 } 1146 1147 /* If the lease has expired, relinquish the address and go back 1148 to the INIT state. */ 1149 if (client->state != S_REQUESTING && 1150 cur_time > client->active->expiry) { 1151 /* Run the client script with the new parameters. */ 1152 script_init("EXPIRE"); 1153 script_write_params("old_", client->active); 1154 script_go(); 1155 1156 client->state = S_INIT; 1157 state_init(); 1158 return; 1159 } 1160 1161 /* Do the exponential backoff... */ 1162 if (!client->interval) 1163 client->interval = config->initial_interval; 1164 else 1165 client->interval += ((arc4random() >> 2) % 1166 (2 * client->interval)); 1167 1168 /* Don't backoff past cutoff. */ 1169 if (client->interval > config->backoff_cutoff) 1170 client->interval = ((config->backoff_cutoff / 2) + 1171 ((arc4random() >> 2) % client->interval)); 1172 1173 /* If the backoff would take us to the expiry time, just set the 1174 timeout to the expiry time. */ 1175 if (client->state != S_REQUESTING && cur_time + client->interval > 1176 client->active->expiry) 1177 client->interval = client->active->expiry - cur_time + 1; 1178 1179 /* If the lease T2 time has elapsed, or if we're not yet bound, 1180 broadcast the DHCPREQUEST rather than unicasting. */ 1181 memset(&destination, 0, sizeof(destination)); 1182 if (client->state == S_REQUESTING || 1183 client->state == S_REBOOTING || 1184 cur_time > client->active->rebind) 1185 destination.sin_addr.s_addr = INADDR_BROADCAST; 1186 else 1187 memcpy(&destination.sin_addr.s_addr, client->destination.iabuf, 1188 sizeof(destination.sin_addr.s_addr)); 1189 destination.sin_port = htons(REMOTE_PORT); 1190 destination.sin_family = AF_INET; 1191 destination.sin_len = sizeof(destination); 1192 1193 if (client->state != S_REQUESTING) 1194 memcpy(&from, client->active->address.iabuf, sizeof(from)); 1195 else 1196 from.s_addr = INADDR_ANY; 1197 1198 /* Record the number of seconds since we started sending. */ 1199 if (client->state == S_REQUESTING) 1200 client->packet.secs = client->secs; 1201 else { 1202 if (interval < 65536) 1203 client->packet.secs = htons(interval); 1204 else 1205 client->packet.secs = htons(65535); 1206 } 1207 1208 note("DHCPREQUEST on %s to %s port %d", ifi->name, 1209 inet_ntoa(destination.sin_addr), ntohs(destination.sin_port)); 1210 1211 send_packet(from, &destination, NULL); 1212 1213 set_timeout_interval(client->interval, send_request); 1214 } 1215 1216 void 1217 send_decline(void) 1218 { 1219 note("DHCPDECLINE on %s to %s port %d", ifi->name, 1220 inet_ntoa(sockaddr_broadcast.sin_addr), 1221 ntohs(sockaddr_broadcast.sin_port)); 1222 1223 send_packet(inaddr_any, &sockaddr_broadcast, NULL); 1224 } 1225 1226 void 1227 make_discover(struct client_lease *lease) 1228 { 1229 unsigned char discover = DHCPDISCOVER; 1230 struct option_data options[256]; 1231 int i; 1232 1233 memset(options, 0, sizeof(options)); 1234 memset(&client->packet, 0, sizeof(client->packet)); 1235 1236 /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */ 1237 i = DHO_DHCP_MESSAGE_TYPE; 1238 options[i].data = &discover; 1239 options[i].len = sizeof(discover); 1240 1241 /* Request the options we want */ 1242 i = DHO_DHCP_PARAMETER_REQUEST_LIST; 1243 options[i].data = config->requested_options; 1244 options[i].len = config->requested_option_count; 1245 1246 /* If we had an address, try to get it again. */ 1247 if (lease) { 1248 client->requested_address = lease->address; 1249 i = DHO_DHCP_REQUESTED_ADDRESS; 1250 options[i].data = lease->address.iabuf; 1251 options[i].len = lease->address.len; 1252 } else 1253 client->requested_address.len = 0; 1254 1255 /* Send any options requested in the config file. */ 1256 for (i = 0; i < 256; i++) 1257 if (!options[i].data && 1258 config->send_options[i].data) { 1259 options[i].data = config->send_options[i].data; 1260 options[i].len = config->send_options[i].len; 1261 } 1262 1263 /* Set up the option buffer to fit in a minimal UDP packet. */ 1264 i = cons_options(options); 1265 if (i == -1 || client->packet.options[i] != DHO_END) 1266 error("options do not fit in DHCPDISCOVER packet."); 1267 client->packet_length = DHCP_FIXED_NON_UDP+i+1; 1268 if (client->packet_length < BOOTP_MIN_LEN) 1269 client->packet_length = BOOTP_MIN_LEN; 1270 1271 client->packet.op = BOOTREQUEST; 1272 client->packet.htype = ifi->hw_address.htype; 1273 client->packet.hlen = ifi->hw_address.hlen; 1274 client->packet.hops = 0; 1275 client->packet.xid = arc4random(); 1276 client->packet.secs = 0; /* filled in by send_discover. */ 1277 client->packet.flags = 0; 1278 1279 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr)); 1280 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr)); 1281 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr)); 1282 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr)); 1283 memcpy(client->packet.chaddr, ifi->hw_address.haddr, 1284 ifi->hw_address.hlen); 1285 } 1286 1287 void 1288 make_request(struct client_lease * lease) 1289 { 1290 unsigned char request = DHCPREQUEST; 1291 struct option_data options[256]; 1292 int i; 1293 1294 memset(options, 0, sizeof(options)); 1295 memset(&client->packet, 0, sizeof(client->packet)); 1296 1297 /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */ 1298 i = DHO_DHCP_MESSAGE_TYPE; 1299 options[i].data = &request; 1300 options[i].len = sizeof(request); 1301 1302 /* Request the options we want */ 1303 i = DHO_DHCP_PARAMETER_REQUEST_LIST; 1304 options[i].data = config->requested_options; 1305 options[i].len = config->requested_option_count; 1306 1307 /* If we are requesting an address that hasn't yet been assigned 1308 to us, use the DHCP Requested Address option. */ 1309 if (client->state == S_REQUESTING) { 1310 /* Send back the server identifier... */ 1311 i = DHO_DHCP_SERVER_IDENTIFIER; 1312 options[i].data = lease->options[i].data; 1313 options[i].len = lease->options[i].len; 1314 } 1315 if (client->state == S_REQUESTING || 1316 client->state == S_REBOOTING) { 1317 client->requested_address = lease->address; 1318 i = DHO_DHCP_REQUESTED_ADDRESS; 1319 options[i].data = lease->address.iabuf; 1320 options[i].len = lease->address.len; 1321 } else 1322 client->requested_address.len = 0; 1323 1324 /* Send any options requested in the config file. */ 1325 for (i = 0; i < 256; i++) 1326 if (!options[i].data && config->send_options[i].data) { 1327 options[i].data = config->send_options[i].data; 1328 options[i].len = config->send_options[i].len; 1329 } 1330 1331 /* Set up the option buffer to fit in a minimal UDP packet. */ 1332 i = cons_options(options); 1333 if (i == -1 || client->packet.options[i] != DHO_END) 1334 error("options do not fit in DHCPREQUEST packet."); 1335 client->packet_length = DHCP_FIXED_NON_UDP+i+1; 1336 if (client->packet_length < BOOTP_MIN_LEN) 1337 client->packet_length = BOOTP_MIN_LEN; 1338 1339 client->packet.op = BOOTREQUEST; 1340 client->packet.htype = ifi->hw_address.htype; 1341 client->packet.hlen = ifi->hw_address.hlen; 1342 client->packet.hops = 0; 1343 client->packet.xid = client->xid; 1344 client->packet.secs = 0; /* Filled in by send_request. */ 1345 client->packet.flags = 0; 1346 1347 /* If we own the address we're requesting, put it in ciaddr; 1348 otherwise set ciaddr to zero. */ 1349 if (client->state == S_BOUND || 1350 client->state == S_RENEWING || 1351 client->state == S_REBINDING) { 1352 memcpy(&client->packet.ciaddr, 1353 lease->address.iabuf, lease->address.len); 1354 } else { 1355 memset(&client->packet.ciaddr, 0, 1356 sizeof(client->packet.ciaddr)); 1357 } 1358 1359 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr)); 1360 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr)); 1361 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr)); 1362 memcpy(client->packet.chaddr, ifi->hw_address.haddr, 1363 ifi->hw_address.hlen); 1364 } 1365 1366 void 1367 make_decline(struct client_lease *lease) 1368 { 1369 struct option_data options[256]; 1370 unsigned char decline = DHCPDECLINE; 1371 int i; 1372 1373 memset(options, 0, sizeof(options)); 1374 memset(&client->packet, 0, sizeof(client->packet)); 1375 1376 /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */ 1377 i = DHO_DHCP_MESSAGE_TYPE; 1378 options[i].data = &decline; 1379 options[i].len = sizeof(decline); 1380 1381 /* Send back the server identifier... */ 1382 i = DHO_DHCP_SERVER_IDENTIFIER; 1383 options[i].data = lease->options[i].data; 1384 options[i].len = lease->options[i].len; 1385 1386 /* Send back the address we're declining. */ 1387 i = DHO_DHCP_REQUESTED_ADDRESS; 1388 options[i].data = lease->address.iabuf; 1389 options[i].len = lease->address.len; 1390 1391 /* Send the uid if the user supplied one. */ 1392 i = DHO_DHCP_CLIENT_IDENTIFIER; 1393 if (config->send_options[i].len) { 1394 options[i].data = config->send_options[i].data; 1395 options[i].len = config->send_options[i].len; 1396 } 1397 1398 /* Set up the option buffer to fit in a minimal UDP packet. */ 1399 i = cons_options(options); 1400 if (i == -1 || client->packet.options[i] != DHO_END) 1401 error("options do not fit in DHCPDECLINE packet."); 1402 client->packet_length = DHCP_FIXED_NON_UDP+i+1; 1403 if (client->packet_length < BOOTP_MIN_LEN) 1404 client->packet_length = BOOTP_MIN_LEN; 1405 1406 client->packet.op = BOOTREQUEST; 1407 client->packet.htype = ifi->hw_address.htype; 1408 client->packet.hlen = ifi->hw_address.hlen; 1409 client->packet.hops = 0; 1410 client->packet.xid = client->xid; 1411 client->packet.secs = 0; /* Filled in by send_request. */ 1412 client->packet.flags = 0; 1413 1414 /* ciaddr must always be zero. */ 1415 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr)); 1416 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr)); 1417 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr)); 1418 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr)); 1419 memcpy(client->packet.chaddr, ifi->hw_address.haddr, 1420 ifi->hw_address.hlen); 1421 } 1422 1423 void 1424 free_client_lease(struct client_lease *lease) 1425 { 1426 int i; 1427 1428 if (lease->server_name) 1429 free(lease->server_name); 1430 if (lease->filename) 1431 free(lease->filename); 1432 for (i = 0; i < 256; i++) { 1433 if (lease->options[i].len) 1434 free(lease->options[i].data); 1435 } 1436 free(lease); 1437 } 1438 1439 void 1440 rewrite_client_leases(void) 1441 { 1442 struct client_lease *lp; 1443 1444 if (!leaseFile) /* XXX */ 1445 error("lease file not open"); 1446 1447 fflush(leaseFile); 1448 rewind(leaseFile); 1449 1450 for (lp = client->leases; lp; lp = lp->next) { 1451 if (client->active && addr_eq(lp->address, 1452 client->active->address)) 1453 continue; 1454 write_client_lease(lp); 1455 } 1456 1457 if (client->active) 1458 write_client_lease(client->active); 1459 1460 fflush(leaseFile); 1461 ftruncate(fileno(leaseFile), ftello(leaseFile)); 1462 fsync(fileno(leaseFile)); 1463 } 1464 1465 void 1466 write_client_lease(struct client_lease *lease) 1467 { 1468 struct tm *t; 1469 int i; 1470 1471 /* If the lease came from the config file, we don't need to stash 1472 a copy in the lease database. */ 1473 if (lease->is_static) 1474 return; 1475 1476 if (!leaseFile) /* XXX */ 1477 error("lease file not open"); 1478 1479 fprintf(leaseFile, "lease {\n"); 1480 if (lease->is_bootp) 1481 fprintf(leaseFile, " bootp;\n"); 1482 fprintf(leaseFile, " interface \"%s\";\n", ifi->name); 1483 fprintf(leaseFile, " fixed-address %s;\n", piaddr(lease->address)); 1484 if (lease->filename) 1485 fprintf(leaseFile, " filename \"%s\";\n", lease->filename); 1486 if (lease->server_name) 1487 fprintf(leaseFile, " server-name \"%s\";\n", 1488 lease->server_name); 1489 for (i = 0; i < 256; i++) 1490 if (lease->options[i].len) 1491 fprintf(leaseFile, " option %s %s;\n", 1492 dhcp_options[i].name, 1493 pretty_print_option(i, &lease->options[i], 1)); 1494 1495 t = gmtime(&lease->renewal); 1496 fprintf(leaseFile, " renew %d %d/%d/%d %02d:%02d:%02d;\n", 1497 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, 1498 t->tm_hour, t->tm_min, t->tm_sec); 1499 t = gmtime(&lease->rebind); 1500 fprintf(leaseFile, " rebind %d %d/%d/%d %02d:%02d:%02d;\n", 1501 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, 1502 t->tm_hour, t->tm_min, t->tm_sec); 1503 t = gmtime(&lease->expiry); 1504 fprintf(leaseFile, " expire %d %d/%d/%d %02d:%02d:%02d;\n", 1505 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, 1506 t->tm_hour, t->tm_min, t->tm_sec); 1507 fprintf(leaseFile, "}\n"); 1508 fflush(leaseFile); 1509 } 1510 1511 void 1512 script_init(char *reason) 1513 { 1514 size_t len; 1515 struct imsg_hdr hdr; 1516 struct buf *buf; 1517 1518 hdr.code = IMSG_SCRIPT_INIT; 1519 hdr.len = sizeof(struct imsg_hdr) + sizeof(size_t) + strlen(reason); 1520 buf = buf_open(hdr.len); 1521 1522 buf_add(buf, &hdr, sizeof(hdr)); 1523 len = strlen(reason); 1524 buf_add(buf, &len, sizeof(len)); 1525 buf_add(buf, reason, len); 1526 1527 buf_close(privfd, buf); 1528 } 1529 1530 void 1531 priv_script_init(char *reason) 1532 { 1533 client->scriptEnvsize = 100; 1534 if (client->scriptEnv == NULL) 1535 client->scriptEnv = 1536 calloc(client->scriptEnvsize, sizeof(char *)); 1537 if (client->scriptEnv == NULL) 1538 error("script_init: no memory for environment"); 1539 1540 client->scriptEnv[0] = strdup(CLIENT_PATH); 1541 if (client->scriptEnv[0] == NULL) 1542 error("script_init: no memory for environment"); 1543 1544 client->scriptEnv[1] = NULL; 1545 1546 script_set_env("", "interface", ifi->name); 1547 1548 script_set_env("", "reason", reason); 1549 } 1550 1551 void 1552 priv_script_write_params(char *prefix, struct client_lease *lease) 1553 { 1554 char buf[256]; 1555 struct option_data o; 1556 int i; 1557 1558 script_set_env(prefix, "ip_address", piaddr(lease->address)); 1559 1560 if (lease->options[DHO_SUBNET_MASK].len && 1561 (lease->options[DHO_SUBNET_MASK].len < 1562 sizeof(lease->address.iabuf))) { 1563 struct iaddr netmask, subnet, broadcast; 1564 1565 memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data, 1566 lease->options[DHO_SUBNET_MASK].len); 1567 netmask.len = lease->options[DHO_SUBNET_MASK].len; 1568 1569 subnet = subnet_number(lease->address, netmask); 1570 if (subnet.len) { 1571 script_set_env(prefix, "network_number", 1572 piaddr(subnet)); 1573 if (!lease->options[DHO_BROADCAST_ADDRESS].len) { 1574 broadcast = broadcast_addr(subnet, netmask); 1575 if (broadcast.len) 1576 script_set_env(prefix, 1577 "broadcast_address", 1578 piaddr(broadcast)); 1579 } 1580 } 1581 } 1582 1583 if (lease->filename) 1584 script_set_env(prefix, "filename", lease->filename); 1585 if (lease->server_name) 1586 script_set_env(prefix, "server_name", 1587 lease->server_name); 1588 1589 for (i = 0; i < 256; i++) { 1590 if (!dhcp_option_ev_name(buf, sizeof(buf), &dhcp_options[i])) 1591 continue; 1592 1593 switch (config->default_actions[i]) { 1594 case ACTION_IGNORE: 1595 break; 1596 1597 case ACTION_DEFAULT: 1598 if (lease->options[i].len) 1599 script_set_env(prefix, buf, 1600 pretty_print_option(i, &lease->options[i], 1601 0)); 1602 else if (config->defaults[i].len) 1603 script_set_env(prefix, buf, 1604 pretty_print_option(i, &config->defaults[i], 1605 0)); 1606 break; 1607 1608 case ACTION_SUPERSEDE: 1609 if (config->defaults[i].len) 1610 script_set_env(prefix, buf, 1611 pretty_print_option(i, &config->defaults[i], 1612 0)); 1613 break; 1614 1615 case ACTION_PREPEND: 1616 o.len = config->defaults[i].len + lease->options[i].len; 1617 if (o.len > 0) { 1618 o.data = calloc(1, o.len); 1619 if (o.data == NULL) 1620 error("no space to prepend '%s' to %s", 1621 config->defaults[i].data, 1622 dhcp_options[i].name); 1623 memcpy(o.data, config->defaults[i].data, 1624 config->defaults[i].len); 1625 memcpy(o.data + config->defaults[i].len, 1626 lease->options[i].data, 1627 lease->options[i].len); 1628 script_set_env(prefix, buf, 1629 pretty_print_option(i, &o, 0)); 1630 free(o.data); 1631 } 1632 break; 1633 1634 case ACTION_APPEND: 1635 o.len = config->defaults[i].len + lease->options[i].len; 1636 if (o.len > 0) { 1637 o.data = calloc(1, o.len); 1638 if (o.data == NULL) 1639 error("no space to append '%s' to %s", 1640 config->defaults[i].data, 1641 dhcp_options[i].name); 1642 memcpy(o.data, lease->options[i].data, 1643 lease->options[i].len); 1644 memcpy(o.data + lease->options[i].len, 1645 config->defaults[i].data, 1646 config->defaults[i].len); 1647 script_set_env(prefix, buf, 1648 pretty_print_option(i, &o, 0)); 1649 free(o.data); 1650 } 1651 break; 1652 } 1653 } 1654 1655 snprintf(buf, sizeof(buf), "%d", (int)lease->expiry); 1656 script_set_env(prefix, "expiry", buf); 1657 } 1658 1659 void 1660 script_write_params(char *prefix, struct client_lease *lease) 1661 { 1662 size_t fn_len = 0, sn_len = 0, pr_len = 0; 1663 struct imsg_hdr hdr; 1664 struct buf *buf; 1665 int i; 1666 1667 if (lease->filename != NULL) 1668 fn_len = strlen(lease->filename); 1669 if (lease->server_name != NULL) 1670 sn_len = strlen(lease->server_name); 1671 if (prefix != NULL) 1672 pr_len = strlen(prefix); 1673 1674 hdr.code = IMSG_SCRIPT_WRITE_PARAMS; 1675 hdr.len = sizeof(hdr) + sizeof(struct client_lease) + 1676 sizeof(size_t) + fn_len + sizeof(size_t) + sn_len + 1677 sizeof(size_t) + pr_len; 1678 1679 for (i = 0; i < 256; i++) 1680 hdr.len += sizeof(int) + lease->options[i].len; 1681 1682 scripttime = time(NULL); 1683 1684 buf = buf_open(hdr.len); 1685 1686 buf_add(buf, &hdr, sizeof(hdr)); 1687 buf_add(buf, lease, sizeof(struct client_lease)); 1688 buf_add(buf, &fn_len, sizeof(fn_len)); 1689 buf_add(buf, lease->filename, fn_len); 1690 buf_add(buf, &sn_len, sizeof(sn_len)); 1691 buf_add(buf, lease->server_name, sn_len); 1692 buf_add(buf, &pr_len, sizeof(pr_len)); 1693 buf_add(buf, prefix, pr_len); 1694 1695 for (i = 0; i < 256; i++) { 1696 buf_add(buf, &lease->options[i].len, 1697 sizeof(lease->options[i].len)); 1698 buf_add(buf, lease->options[i].data, 1699 lease->options[i].len); 1700 } 1701 1702 buf_close(privfd, buf); 1703 } 1704 1705 int 1706 script_go(void) 1707 { 1708 struct imsg_hdr hdr; 1709 struct buf *buf; 1710 int ret; 1711 1712 scripttime = time(NULL); 1713 1714 hdr.code = IMSG_SCRIPT_GO; 1715 hdr.len = sizeof(struct imsg_hdr); 1716 1717 buf = buf_open(hdr.len); 1718 1719 buf_add(buf, &hdr, sizeof(hdr)); 1720 buf_close(privfd, buf); 1721 1722 bzero(&hdr, sizeof(hdr)); 1723 buf_read(privfd, &hdr, sizeof(hdr)); 1724 if (hdr.code != IMSG_SCRIPT_GO_RET) 1725 error("unexpected msg type %u", hdr.code); 1726 if (hdr.len != sizeof(hdr) + sizeof(int)) 1727 error("received corrupted message"); 1728 buf_read(privfd, &ret, sizeof(ret)); 1729 1730 return (ret); 1731 } 1732 1733 int 1734 priv_script_go(void) 1735 { 1736 char *scriptName, *argv[2], **envp; 1737 int pid, wpid, wstatus; 1738 1739 scripttime = time(NULL); 1740 1741 scriptName = config->script_name; 1742 envp = client->scriptEnv; 1743 1744 argv[0] = scriptName; 1745 argv[1] = NULL; 1746 1747 pid = fork(); 1748 if (pid < 0) { 1749 error("fork: %m"); 1750 wstatus = 0; 1751 } else if (pid) { 1752 do { 1753 wpid = wait(&wstatus); 1754 } while (wpid != pid && wpid > 0); 1755 if (wpid < 0) { 1756 error("wait: %m"); 1757 wstatus = 0; 1758 } 1759 } else { 1760 execve(scriptName, argv, envp); 1761 error("execve (%s, ...): %m", scriptName); 1762 } 1763 1764 script_flush_env(); 1765 1766 return (WEXITSTATUS(wstatus)); 1767 } 1768 1769 void 1770 script_set_env(const char *prefix, const char *name, const char *value) 1771 { 1772 int i, j, namelen; 1773 1774 /* No `` or $() command substitution allowed in environment values! */ 1775 for (j = 0; j < strlen(value); j++) 1776 switch (value[j]) { 1777 case '`': 1778 case '$': 1779 warning("illegal character (%c) in value '%s'", 1780 value[j], value); 1781 /* Ignore this option */ 1782 return; 1783 } 1784 1785 namelen = strlen(name); 1786 1787 for (i = 0; client->scriptEnv[i]; i++) 1788 if (strncmp(client->scriptEnv[i], name, namelen) == 0 && 1789 client->scriptEnv[i][namelen] == '=') 1790 break; 1791 1792 if (client->scriptEnv[i]) 1793 /* Reuse the slot. */ 1794 free(client->scriptEnv[i]); 1795 else { 1796 /* New variable. Expand if necessary. */ 1797 if (i >= client->scriptEnvsize - 1) { 1798 char **newscriptEnv; 1799 int newscriptEnvsize = client->scriptEnvsize + 50; 1800 1801 newscriptEnv = realloc(client->scriptEnv, 1802 newscriptEnvsize); 1803 if (newscriptEnv == NULL) { 1804 free(client->scriptEnv); 1805 client->scriptEnv = NULL; 1806 client->scriptEnvsize = 0; 1807 error("script_set_env: no memory for variable"); 1808 } 1809 client->scriptEnv = newscriptEnv; 1810 client->scriptEnvsize = newscriptEnvsize; 1811 } 1812 /* need to set the NULL pointer at end of array beyond 1813 the new slot. */ 1814 client->scriptEnv[i + 1] = NULL; 1815 } 1816 /* Allocate space and format the variable in the appropriate slot. */ 1817 client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 + 1818 strlen(value) + 1); 1819 if (client->scriptEnv[i] == NULL) 1820 error("script_set_env: no memory for variable assignment"); 1821 snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) + 1822 1 + strlen(value) + 1, "%s%s=%s", prefix, name, value); 1823 } 1824 1825 void 1826 script_flush_env(void) 1827 { 1828 int i; 1829 1830 for (i = 0; client->scriptEnv[i]; i++) { 1831 free(client->scriptEnv[i]); 1832 client->scriptEnv[i] = NULL; 1833 } 1834 client->scriptEnvsize = 0; 1835 } 1836 1837 int 1838 dhcp_option_ev_name(char *buf, size_t buflen, const struct option *option) 1839 { 1840 size_t i; 1841 1842 for (i = 0; option->name[i]; i++) { 1843 if (i + 1 == buflen) 1844 return 0; 1845 if (option->name[i] == '-') 1846 buf[i] = '_'; 1847 else 1848 buf[i] = option->name[i]; 1849 } 1850 1851 buf[i] = 0; 1852 return 1; 1853 } 1854 1855 void 1856 go_daemon(void) 1857 { 1858 char buf[256]; 1859 int fd; 1860 1861 /* 1862 * Only once 1863 */ 1864 if (no_daemon == 2) 1865 return; 1866 1867 /* 1868 * Setup pidfile, kill any dhclient already running for this 1869 * interface. 1870 */ 1871 snprintf(buf, sizeof(buf), "/var/run/dhclient.%s.pid", orig_ifname); 1872 fd = open(buf, O_RDWR|O_CREAT, 0644); 1873 if (fd >= 0) { 1874 if (killclient(fd)) { 1875 fprintf(stderr, 1876 "starting dhclient on %s\n", 1877 orig_ifname); 1878 } else { 1879 fprintf(stderr, 1880 "restarting dhclient on %s\n", 1881 orig_ifname); 1882 } 1883 } 1884 1885 /* 1886 * Daemonize if requested 1887 */ 1888 if (no_daemon == 0) { 1889 /* Stop logging to stderr... */ 1890 log_perror = 0; 1891 1892 if (daemon(1, 0) == -1) 1893 error("daemon"); 1894 1895 /* we are chrooted, daemon(3) fails to open /dev/null */ 1896 if (nullfd != -1) { 1897 dup2(nullfd, STDIN_FILENO); 1898 dup2(nullfd, STDOUT_FILENO); 1899 dup2(nullfd, STDERR_FILENO); 1900 close(nullfd); 1901 nullfd = -1; 1902 } 1903 } 1904 1905 /* 1906 * No further daemonizations, write out pid file and lock. 1907 */ 1908 no_daemon = 2; 1909 if (fd >= 0) { 1910 lseek(fd, 0L, SEEK_SET); 1911 ftruncate(fd, 0); 1912 snprintf(buf, sizeof(buf), "%ld\n", (long)getpid()); 1913 write(fd, buf, strlen(buf)); 1914 flock(fd, LOCK_EX); 1915 /* leave descriptor open and locked */ 1916 } 1917 } 1918 1919 int 1920 check_option(struct client_lease *l, int option) 1921 { 1922 char *opbuf; 1923 char *sbuf; 1924 1925 /* we use this, since this is what gets passed to dhclient-script */ 1926 1927 opbuf = pretty_print_option(option, &l->options[option], 0); 1928 1929 sbuf = option_as_string(option, l->options[option].data, 1930 l->options[option].len); 1931 1932 switch (option) { 1933 case DHO_SUBNET_MASK: 1934 case DHO_SWAP_SERVER: 1935 case DHO_BROADCAST_ADDRESS: 1936 case DHO_DHCP_SERVER_IDENTIFIER: 1937 case DHO_ROUTER_SOLICITATION_ADDRESS: 1938 case DHO_DHCP_REQUESTED_ADDRESS: 1939 if (ipv4addrs(opbuf) == 0) { 1940 warning("Invalid IP address in option %s: %s", 1941 dhcp_options[option].name, opbuf); 1942 return (0); 1943 } 1944 if (l->options[option].len != 4) { /* RFC 2132 */ 1945 warning("warning: Only 1 IP address allowed in " 1946 "%s option; length %d, must be 4", 1947 dhcp_options[option].name, 1948 l->options[option].len); 1949 l->options[option].len = 4; 1950 } 1951 return (1); 1952 case DHO_TIME_SERVERS: 1953 case DHO_NAME_SERVERS: 1954 case DHO_ROUTERS: 1955 case DHO_DOMAIN_NAME_SERVERS: 1956 case DHO_LOG_SERVERS: 1957 case DHO_COOKIE_SERVERS: 1958 case DHO_LPR_SERVERS: 1959 case DHO_IMPRESS_SERVERS: 1960 case DHO_RESOURCE_LOCATION_SERVERS: 1961 case DHO_NIS_SERVERS: 1962 case DHO_NTP_SERVERS: 1963 case DHO_NETBIOS_NAME_SERVERS: 1964 case DHO_NETBIOS_DD_SERVER: 1965 case DHO_FONT_SERVERS: 1966 if (ipv4addrs(opbuf) == 0) { 1967 warning("Invalid IP address in option %s: %s", 1968 dhcp_options[option].name, opbuf); 1969 return (0); 1970 } 1971 return (1); 1972 case DHO_HOST_NAME: 1973 case DHO_DOMAIN_NAME: 1974 case DHO_NIS_DOMAIN: 1975 if (!res_hnok(sbuf)) { 1976 warning("Bogus Host Name option %d: %s (%s)", option, 1977 sbuf, opbuf); 1978 l->options[option].len = 0; 1979 free(l->options[option].data); 1980 } 1981 return (1); 1982 case DHO_PAD: 1983 case DHO_TIME_OFFSET: 1984 case DHO_BOOT_SIZE: 1985 case DHO_MERIT_DUMP: 1986 case DHO_ROOT_PATH: 1987 case DHO_EXTENSIONS_PATH: 1988 case DHO_IP_FORWARDING: 1989 case DHO_NON_LOCAL_SOURCE_ROUTING: 1990 case DHO_POLICY_FILTER: 1991 case DHO_MAX_DGRAM_REASSEMBLY: 1992 case DHO_DEFAULT_IP_TTL: 1993 case DHO_PATH_MTU_AGING_TIMEOUT: 1994 case DHO_PATH_MTU_PLATEAU_TABLE: 1995 case DHO_INTERFACE_MTU: 1996 case DHO_ALL_SUBNETS_LOCAL: 1997 case DHO_PERFORM_MASK_DISCOVERY: 1998 case DHO_MASK_SUPPLIER: 1999 case DHO_ROUTER_DISCOVERY: 2000 case DHO_STATIC_ROUTES: 2001 case DHO_TRAILER_ENCAPSULATION: 2002 case DHO_ARP_CACHE_TIMEOUT: 2003 case DHO_IEEE802_3_ENCAPSULATION: 2004 case DHO_DEFAULT_TCP_TTL: 2005 case DHO_TCP_KEEPALIVE_INTERVAL: 2006 case DHO_TCP_KEEPALIVE_GARBAGE: 2007 case DHO_VENDOR_ENCAPSULATED_OPTIONS: 2008 case DHO_NETBIOS_NODE_TYPE: 2009 case DHO_NETBIOS_SCOPE: 2010 case DHO_X_DISPLAY_MANAGER: 2011 case DHO_DHCP_LEASE_TIME: 2012 case DHO_DHCP_OPTION_OVERLOAD: 2013 case DHO_DHCP_MESSAGE_TYPE: 2014 case DHO_DHCP_PARAMETER_REQUEST_LIST: 2015 case DHO_DHCP_MESSAGE: 2016 case DHO_DHCP_MAX_MESSAGE_SIZE: 2017 case DHO_DHCP_RENEWAL_TIME: 2018 case DHO_DHCP_REBINDING_TIME: 2019 case DHO_DHCP_CLASS_IDENTIFIER: 2020 case DHO_DHCP_CLIENT_IDENTIFIER: 2021 case DHO_DHCP_USER_CLASS_ID: 2022 case DHO_TFTP_SERVER: 2023 case DHO_END: 2024 return (1); 2025 case DHO_CLASSLESS_ROUTES: 2026 return (check_classless_option(l->options[option].data, 2027 l->options[option].len)); 2028 default: 2029 if (!unknown_ok) 2030 warning("unknown dhcp option value 0x%x", option); 2031 return (unknown_ok); 2032 } 2033 } 2034 2035 /* RFC 3442 The Classless Static Routes option checks */ 2036 int 2037 check_classless_option(unsigned char *data, int len) 2038 { 2039 int i = 0; 2040 unsigned char width; 2041 in_addr_t addr, mask; 2042 2043 if (len < 5) { 2044 warning("Too small length: %d", len); 2045 return (0); 2046 } 2047 while(i < len) { 2048 width = data[i++]; 2049 if (width == 0) { 2050 i += 4; 2051 continue; 2052 } else if (width < 9) { 2053 addr = (in_addr_t)(data[i] << 24); 2054 i += 1; 2055 } else if (width < 17) { 2056 addr = (in_addr_t)(data[i] << 24) + 2057 (in_addr_t)(data[i + 1] << 16); 2058 i += 2; 2059 } else if (width < 25) { 2060 addr = (in_addr_t)(data[i] << 24) + 2061 (in_addr_t)(data[i + 1] << 16) + 2062 (in_addr_t)(data[i + 2] << 8); 2063 i += 3; 2064 } else if (width < 33) { 2065 addr = (in_addr_t)(data[i] << 24) + 2066 (in_addr_t)(data[i + 1] << 16) + 2067 (in_addr_t)(data[i + 2] << 8) + 2068 data[i + 3]; 2069 i += 4; 2070 } else { 2071 warning("Incorrect subnet width: %d", width); 2072 return (0); 2073 } 2074 mask = (in_addr_t)(~0) << (32 - width); 2075 addr = ntohl(addr); 2076 mask = ntohl(mask); 2077 2078 /* 2079 * From RFC 3442: 2080 * ... After deriving a subnet number and subnet mask 2081 * from each destination descriptor, the DHCP client 2082 * MUST zero any bits in the subnet number where the 2083 * corresponding bit in the mask is zero... 2084 */ 2085 if ((addr & mask) != addr) { 2086 addr &= mask; 2087 data[i - 1] = (unsigned char)( 2088 (addr >> (((32 - width)/8)*8)) & 0xFF); 2089 } 2090 i += 4; 2091 } 2092 if (i > len) { 2093 warning("Incorrect data length: %d (must be %d)", len, i); 2094 return (0); 2095 } 2096 return (1); 2097 } 2098 2099 int 2100 res_hnok(const char *name) 2101 { 2102 const char *dn = name; 2103 int pch = '.', ch = *dn++; 2104 int warn = 0; 2105 2106 while (ch != '\0') { 2107 int nch = *dn++; 2108 2109 if (ch == '.') { 2110 ; 2111 } else if (pch == '.' || nch == '.' || nch == '\0') { 2112 if (!isalnum(ch)) 2113 return (0); 2114 } else if (!isalnum(ch) && ch != '-' && ch != '_') 2115 return (0); 2116 else if (ch == '_' && warn == 0) { 2117 warning("warning: hostname %s contains an " 2118 "underscore which violates RFC 952", name); 2119 warn++; 2120 } 2121 pch = ch, ch = nch; 2122 } 2123 return (1); 2124 } 2125 2126 /* Does buf consist only of dotted decimal ipv4 addrs? 2127 * return how many if so, 2128 * otherwise, return 0 2129 */ 2130 int 2131 ipv4addrs(char * buf) 2132 { 2133 struct in_addr jnk; 2134 int count = 0; 2135 2136 while (inet_aton(buf, &jnk) == 1){ 2137 count++; 2138 while (*buf == '.' || isdigit(*buf)) 2139 buf++; 2140 if (*buf == '\0') 2141 return (count); 2142 while (*buf == ' ') 2143 buf++; 2144 } 2145 return (0); 2146 } 2147 2148 char * 2149 option_as_string(unsigned int code, unsigned char *data, int len) 2150 { 2151 static char optbuf[32768]; /* XXX */ 2152 char *op = optbuf; 2153 int opleft = sizeof(optbuf); 2154 unsigned char *dp = data; 2155 2156 if (code > 255) 2157 error("option_as_string: bad code %d", code); 2158 2159 for (; dp < data + len; dp++) { 2160 if (!isascii(*dp) || !isprint(*dp)) { 2161 if (dp + 1 != data + len || *dp != 0) { 2162 size_t oplen; 2163 snprintf(op, opleft, "\\%03o", *dp); 2164 oplen = strlen(op); 2165 op += oplen; 2166 opleft -= oplen; 2167 } 2168 } else if (*dp == '"' || *dp == '\'' || *dp == '$' || 2169 *dp == '`' || *dp == '\\') { 2170 *op++ = '\\'; 2171 *op++ = *dp; 2172 opleft -= 2; 2173 } else { 2174 *op++ = *dp; 2175 opleft--; 2176 } 2177 } 2178 if (opleft < 1) 2179 goto toobig; 2180 *op = 0; 2181 return optbuf; 2182 toobig: 2183 warning("dhcp option too large"); 2184 return "<error>"; 2185 } 2186 2187 int 2188 fork_privchld(int fd, int fd2) 2189 { 2190 struct pollfd pfd[1]; 2191 int nfds, pfail = 0; 2192 pid_t pid; 2193 int omask; 2194 2195 omask = sigblock(sigmask(SIGINT)|sigmask(SIGHUP)); 2196 pid = fork(); 2197 if (pid > 0) 2198 monitor_pid = pid; 2199 sigsetmask(omask); 2200 2201 switch (pid) { 2202 case -1: 2203 error("cannot fork"); 2204 break; 2205 case 0: 2206 break; 2207 default: 2208 return (0); 2209 } 2210 2211 if (chdir("/") == -1) 2212 error("chdir(\"/\")"); 2213 2214 setproctitle("%s [priv]", ifi->name); 2215 2216 dup2(nullfd, STDIN_FILENO); 2217 dup2(nullfd, STDOUT_FILENO); 2218 dup2(nullfd, STDERR_FILENO); 2219 close(nullfd); 2220 close(fd2); 2221 2222 for (;;) { 2223 pfd[0].fd = fd; 2224 pfd[0].events = POLLIN; 2225 if ((nfds = poll(pfd, 1, INFTIM)) == -1) 2226 if (errno != EINTR) 2227 error("poll error"); 2228 2229 /* 2230 * Handle temporary errors, but bail if they persist. 2231 */ 2232 if (nfds == 0 || !(pfd[0].revents & POLLIN)) { 2233 if (pfail > POLL_FAILURES) 2234 error("poll failed > %d times", POLL_FAILURES); 2235 sleep(pfail * POLL_FAILURE_WAIT); 2236 pfail++; 2237 continue; 2238 } 2239 2240 dispatch_imsg(fd); 2241 } 2242 } 2243 2244 void 2245 get_ifname(char *ifname, char *arg) 2246 { 2247 struct ifgroupreq ifgr; 2248 struct ifg_req *ifg; 2249 int s, len; 2250 2251 if (!strcmp(arg, "egress")) { 2252 s = socket(AF_INET, SOCK_DGRAM, 0); 2253 if (s == -1) 2254 error("socket error"); 2255 bzero(&ifgr, sizeof(ifgr)); 2256 strlcpy(ifgr.ifgr_name, "egress", sizeof(ifgr.ifgr_name)); 2257 if (ioctl(s, SIOCGIFGMEMB, (caddr_t)&ifgr) == -1) { 2258 if (errno == ENOENT) 2259 error("no interface in group egress found"); 2260 error("ioctl SIOCGIFGMEMB: %m"); 2261 } 2262 len = ifgr.ifgr_len; 2263 if ((ifgr.ifgr_groups = calloc(1, len)) == NULL) 2264 error("get_ifname"); 2265 if (ioctl(s, SIOCGIFGMEMB, (caddr_t)&ifgr) == -1) 2266 error("ioctl SIOCGIFGMEMB: %m"); 2267 2268 arg = NULL; 2269 for (ifg = ifgr.ifgr_groups; 2270 ifg && len >= sizeof(struct ifg_req); ifg++) { 2271 len -= sizeof(struct ifg_req); 2272 if (arg) 2273 error("too many interfaces in group egress"); 2274 arg = ifg->ifgrq_member; 2275 } 2276 2277 if (strlcpy(ifi->name, arg, IFNAMSIZ) >= IFNAMSIZ) 2278 error("Interface name too long: %m"); 2279 2280 free(ifgr.ifgr_groups); 2281 close(s); 2282 } else if (strlcpy(ifi->name, arg, IFNAMSIZ) >= IFNAMSIZ) 2283 error("Interface name too long"); 2284 } 2285 2286 static 2287 void 2288 sig_handle(int signo) 2289 { 2290 if (monitor_pid > 0) 2291 kill(monitor_pid, signo); 2292 fprintf(stderr, "killed by signal\n"); 2293 exit(1); 2294 } 2295 2296 static 2297 int 2298 killclient(int fd) 2299 { 2300 int noclient = 1; 2301 2302 /* 2303 * Kill previously running dhclient 2304 */ 2305 if (flock(fd, LOCK_EX|LOCK_NB) < 0) { 2306 char buf[256]; 2307 ssize_t n; 2308 pid_t pid; 2309 2310 lseek(fd, 0L, SEEK_SET); 2311 n = read(fd, buf, sizeof(buf)); 2312 if (n > 0) { 2313 buf[n-1] = 0; 2314 pid = strtol(buf, NULL, 10); 2315 if ((int)pid > 0) { 2316 noclient = 0; 2317 kill(pid, SIGINT); 2318 } 2319 } 2320 if (flock(fd, LOCK_EX|LOCK_NB) < 0) 2321 usleep(20000); 2322 while (flock(fd, LOCK_EX|LOCK_NB) < 0) 2323 sleep(1); 2324 } 2325 return noclient; 2326 } 2327