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) __dead2; 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 unsigned 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 /* 317 * dport wpa_supplicant uses 'start ifc' instead of 'ifc', allow 318 * the 'start' keyword. 319 */ 320 if (argc > 1) { 321 if (strcmp(argv[0], "start") == 0) { 322 --argc; 323 ++argv; 324 stayalive = 1; 325 } else if (strcmp(argv[0], "stop") == 0) { 326 dokillclient = 1; 327 --argc; 328 ++argv; 329 } 330 } 331 332 if (argc != 1) 333 usage(); 334 orig_ifname = argv[0]; 335 336 if (dokillclient) { 337 char buf[256]; 338 339 snprintf(buf, sizeof(buf), 340 "/var/run/dhclient.%s.pid", orig_ifname); 341 fd = open(buf, O_RDWR, 0644); 342 if (fd < 0 || killclient(fd)) { 343 fprintf(stderr, 344 "no dhclient running on %s\n", 345 orig_ifname); 346 } else { 347 fprintf(stderr, 348 "stopping dhclient on %s\n", 349 orig_ifname); 350 } 351 if (fd >= 0) 352 close(fd); 353 exit(1); 354 } 355 356 if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1) 357 error("cannot open %s: %m", _PATH_DEVNULL); 358 359 /* 360 * If asked to stay alive forever get our daemon going right now 361 * Then set up to fork/monitor and refork on exit. 362 * 363 * When I say 'forever' I really mean it. If there are configuration 364 * problems or missing interfaces or whatever, dhclient will wait 365 * 10 seconds and try again. 366 */ 367 if (stayalive) { 368 pid_t pid; 369 pid_t rpid; 370 int omask; 371 372 go_daemon(); 373 374 for (;;) { 375 omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP)); 376 pid = fork(); 377 if (pid > 0) 378 monitor_pid = pid; 379 sigsetmask(omask); 380 381 if (pid == 0) /* child falls out of loop */ 382 break; 383 while (pid > 0) { 384 rpid = waitpid(pid, NULL, 0); 385 if (rpid == pid) 386 break; 387 if (rpid != EINTR) 388 break; 389 } 390 sleep(10); 391 } 392 } 393 394 ifi = calloc(1, sizeof(*ifi)); 395 if (ifi == NULL) 396 error("ifi calloc"); 397 client = calloc(1, sizeof(*client)); 398 if (client == NULL) 399 error("client calloc"); 400 config = calloc(1, sizeof(*config)); 401 if (config == NULL) 402 error("config calloc"); 403 404 get_ifname(ifi->name, argv[0]); 405 406 if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s", 407 _PATH_DHCLIENT_DB, ifi->name) == -1) 408 error("asprintf"); 409 410 if (quiet) 411 log_perror = 0; 412 413 tzset(); 414 415 memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast)); 416 sockaddr_broadcast.sin_family = AF_INET; 417 sockaddr_broadcast.sin_port = htons(REMOTE_PORT); 418 sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST; 419 sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast); 420 inaddr_any.s_addr = INADDR_ANY; 421 422 read_client_conf(); 423 424 if (interface_status(ifi->name) == 0) { 425 interface_link_forceup(ifi->name); 426 /* Give it up to 4 seconds of silent grace to find link */ 427 i = -4; 428 } else { 429 i = 0; 430 } 431 432 while (!(ifi->linkstat = interface_status(ifi->name))) { 433 if (i == 0) 434 fprintf(stderr, "%s: no link ...", ifi->name); 435 else if (i > 0) 436 fprintf(stderr, "."); 437 fflush(stderr); 438 if (++i > config->link_timeout) { 439 fprintf(stderr, " sleeping\n"); 440 goto dispatch; 441 } 442 sleep(1); 443 } 444 if (i > 0) 445 fprintf(stderr, " got link\n"); 446 447 dispatch: 448 if ((pw = getpwnam("_dhcp")) == NULL) 449 error("no such user: _dhcp"); 450 451 if (pipe(pipe_fd) == -1) 452 error("pipe"); 453 454 go_daemon(); 455 fork_privchld(pipe_fd[0], pipe_fd[1]); 456 457 close(pipe_fd[0]); 458 privfd = pipe_fd[1]; 459 460 if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1) 461 error("can't open and lock %s: %m", path_dhclient_db); 462 read_client_leases(); 463 if ((leaseFile = fopen(path_dhclient_db, "w")) == NULL) 464 error("can't open %s: %m", path_dhclient_db); 465 rewrite_client_leases(); 466 close(fd); 467 468 if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1) 469 error("socket(PF_ROUTE, SOCK_RAW): %m"); 470 471 /* set up the interface */ 472 discover_interface(); 473 474 if (chroot(_PATH_VAREMPTY) == -1) 475 error("chroot"); 476 if (chdir("/") == -1) 477 error("chdir(\"/\")"); 478 479 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) 480 error("setresgid"); 481 if (setgroups(1, &pw->pw_gid) == -1) 482 error("setgroups"); 483 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) 484 error("setresuid"); 485 486 endpwent(); 487 488 setproctitle("%s", ifi->name); 489 490 if (ifi->linkstat) { 491 client->state = S_REBOOTING; 492 state_reboot(); 493 } 494 dispatch(); 495 496 /* not reached */ 497 return (0); 498 } 499 500 void 501 usage(void) 502 { 503 fprintf(stderr, "usage: %s [-dqu] [-c file] [-l file] interface\n", 504 getprogname()); 505 exit(1); 506 } 507 508 /* 509 * Individual States: 510 * 511 * Each routine is called from the dhclient_state_machine() in one of 512 * these conditions: 513 * -> entering INIT state 514 * -> recvpacket_flag == 0: timeout in this state 515 * -> otherwise: received a packet in this state 516 * 517 * Return conditions as handled by dhclient_state_machine(): 518 * Returns 1, sendpacket_flag = 1: send packet, reset timer. 519 * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone). 520 * Returns 0: finish the nap which was interrupted for no good reason. 521 * 522 * Several per-interface variables are used to keep track of the process: 523 * active_lease: the lease that is being used on the interface 524 * (null pointer if not configured yet). 525 * offered_leases: leases corresponding to DHCPOFFER messages that have 526 * been sent to us by DHCP servers. 527 * acked_leases: leases corresponding to DHCPACK messages that have been 528 * sent to us by DHCP servers. 529 * sendpacket: DHCP packet we're trying to send. 530 * destination: IP address to send sendpacket to 531 * In addition, there are several relevant per-lease variables. 532 * T1_expiry, T2_expiry, lease_expiry: lease milestones 533 * In the active lease, these control the process of renewing the lease; 534 * In leases on the acked_leases list, this simply determines when we 535 * can no longer legitimately use the lease. 536 */ 537 void 538 state_reboot(void) 539 { 540 /* Cancel all timeouts, since a link state change gets us here 541 and can happen anytime. */ 542 cancel_timeout(); 543 544 /* If we don't remember an active lease, go straight to INIT. */ 545 if (!client->active || client->active->is_bootp) { 546 client->state = S_INIT; 547 state_init(); 548 return; 549 } 550 551 /* make_request doesn't initialize xid because it normally comes 552 from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER, 553 so pick an xid now. */ 554 client->xid = arc4random(); 555 556 /* Make a DHCPREQUEST packet, and set appropriate per-interface 557 flags. */ 558 make_request(client->active); 559 client->destination = iaddr_broadcast; 560 client->first_sending = time(NULL); 561 client->interval = 0; 562 563 send_request(); 564 } 565 566 /* 567 * Called when a lease has completely expired and we've 568 * been unable to renew it. 569 */ 570 void 571 state_init(void) 572 { 573 /* Make a DHCPDISCOVER packet, and set appropriate per-interface 574 flags. */ 575 make_discover(client->active); 576 client->xid = client->packet.xid; 577 client->destination = iaddr_broadcast; 578 client->state = S_SELECTING; 579 client->first_sending = time(NULL); 580 client->interval = 0; 581 582 send_discover(); 583 } 584 585 /* 586 * state_selecting is called when one or more DHCPOFFER packets 587 * have been received and a configurable period of time has passed. 588 */ 589 void 590 state_selecting(void) 591 { 592 struct client_lease *lp, *next, *picked; 593 time_t cur_time; 594 595 /* Cancel state_selecting and send_discover timeouts, since either 596 one could have got us here. */ 597 cancel_timeout(); 598 599 /* We have received one or more DHCPOFFER packets. Currently, 600 the only criterion by which we judge leases is whether or 601 not we get a response when we arp for them. */ 602 picked = NULL; 603 for (lp = client->offered_leases; lp; lp = next) { 604 next = lp->next; 605 606 if (!picked) { 607 picked = lp; 608 } else { 609 make_decline(lp); 610 send_decline(); 611 free_client_lease(lp); 612 } 613 } 614 client->offered_leases = NULL; 615 616 /* If we just tossed all the leases we were offered, go back 617 to square one. */ 618 if (!picked) { 619 client->state = S_INIT; 620 state_init(); 621 return; 622 } 623 picked->next = NULL; 624 625 time(&cur_time); 626 627 /* If it was a BOOTREPLY, we can just take the address right now. */ 628 if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) { 629 client->new = picked; 630 631 /* Make up some lease expiry times 632 XXX these should be configurable. */ 633 client->new->expiry = cur_time + 12000; 634 client->new->renewal += cur_time + 8000; 635 client->new->rebind += cur_time + 10000; 636 637 client->state = S_REQUESTING; 638 639 /* Bind to the address we received. */ 640 bind_lease(); 641 return; 642 } 643 644 /* Go to the REQUESTING state. */ 645 client->destination = iaddr_broadcast; 646 client->state = S_REQUESTING; 647 client->first_sending = cur_time; 648 client->interval = 0; 649 650 /* Make a DHCPREQUEST packet from the lease we picked. */ 651 make_request(picked); 652 client->xid = client->packet.xid; 653 654 /* Toss the lease we picked - we'll get it back in a DHCPACK. */ 655 free_client_lease(picked); 656 657 send_request(); 658 } 659 660 void 661 dhcpack(struct iaddr client_addr, struct option_data *options) 662 { 663 struct client_lease *lease; 664 time_t cur_time; 665 666 667 if (client->state != S_REBOOTING && 668 client->state != S_REQUESTING && 669 client->state != S_RENEWING && 670 client->state != S_REBINDING) 671 return; 672 673 674 lease = packet_to_lease(options); 675 if (!lease) { 676 note("packet_to_lease failed."); 677 return; 678 } 679 680 client->new = lease; 681 682 /* Stop resending DHCPREQUEST. */ 683 cancel_timeout(); 684 685 /* Figure out the lease time. */ 686 if (client->new->options[DHO_DHCP_LEASE_TIME].data) 687 client->new->expiry = 688 getULong(client->new->options[DHO_DHCP_LEASE_TIME].data); 689 else 690 client->new->expiry = DEFAULT_LEASE_TIME; 691 /* A number that looks negative here is really just very large, 692 because the lease expiry offset is unsigned. */ 693 if (client->new->expiry < 0) 694 client->new->expiry = TIME_MAX; 695 /* XXX should be fixed by resetting the client state */ 696 if (client->new->expiry < 60) 697 client->new->expiry = 60; 698 699 /* Take the server-provided renewal time if there is one; 700 otherwise figure it out according to the spec. */ 701 if (client->new->options[DHO_DHCP_RENEWAL_TIME].len) 702 client->new->renewal = 703 getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data); 704 else 705 client->new->renewal = client->new->expiry / 2; 706 707 /* Same deal with the rebind time. */ 708 if (client->new->options[DHO_DHCP_REBINDING_TIME].len) 709 client->new->rebind = 710 getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data); 711 else 712 client->new->rebind = client->new->renewal + 713 client->new->renewal / 2 + client->new->renewal / 4; 714 715 time(&cur_time); 716 717 client->new->expiry += cur_time; 718 /* Lease lengths can never be negative. */ 719 if (client->new->expiry < cur_time) 720 client->new->expiry = TIME_MAX; 721 client->new->renewal += cur_time; 722 if (client->new->renewal < cur_time) 723 client->new->renewal = TIME_MAX; 724 client->new->rebind += cur_time; 725 if (client->new->rebind < cur_time) 726 client->new->rebind = TIME_MAX; 727 728 bind_lease(); 729 } 730 731 void 732 bind_lease(void) 733 { 734 /* Run the client script with the new parameters. */ 735 script_init((client->state == S_REQUESTING ? "BOUND" : 736 (client->state == S_RENEWING ? "RENEW" : 737 (client->state == S_REBOOTING ? "REBOOT" : "REBIND")))); 738 if (client->active && client->state != S_REBOOTING) 739 script_write_params("old_", client->active); 740 script_write_params("new_", client->new); 741 script_go(); 742 743 /* Replace the old active lease with the new one. */ 744 if (client->active) 745 free_client_lease(client->active); 746 client->active = client->new; 747 client->new = NULL; 748 749 /* Write out new leases file. */ 750 rewrite_client_leases(); 751 752 /* Set timeout to start the renewal process. */ 753 set_timeout(client->active->renewal, state_bound); 754 755 note("bound to %s -- renewal in %lld seconds.", 756 piaddr(client->active->address), 757 (long long)(client->active->renewal - time(NULL))); 758 client->state = S_BOUND; 759 } 760 761 /* 762 * state_bound is called when we've successfully bound to a particular 763 * lease, but the renewal time on that lease has expired. We are 764 * expected to unicast a DHCPREQUEST to the server that gave us our 765 * original lease. 766 */ 767 void 768 state_bound(void) 769 { 770 /* T1 has expired. */ 771 make_request(client->active); 772 client->xid = client->packet.xid; 773 774 if (client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) { 775 memcpy(client->destination.iabuf, 776 client->active->options[DHO_DHCP_SERVER_IDENTIFIER].data, 777 4); 778 client->destination.len = 4; 779 } else 780 client->destination = iaddr_broadcast; 781 782 client->first_sending = time(NULL); 783 client->interval = 0; 784 client->state = S_RENEWING; 785 786 send_request(); 787 } 788 789 void 790 dhcpoffer(struct iaddr client_addr, struct option_data *options) 791 { 792 struct client_lease *lease, *lp; 793 int i; 794 time_t stop_selecting; 795 char *name = options[DHO_DHCP_MESSAGE_TYPE].len ? "DHCPOFFER" : 796 "BOOTREPLY"; 797 798 799 if (client->state != S_SELECTING) 800 return; 801 802 803 /* If this lease doesn't supply the minimum required parameters, 804 blow it off. */ 805 for (i = 0; config->required_options[i]; i++) { 806 if (!options[config->required_options[i]].len) { 807 note("%s isn't satisfactory.", name); 808 return; 809 } 810 } 811 812 /* If we've already seen this lease, don't record it again. */ 813 for (lease = client->offered_leases; 814 lease; lease = lease->next) { 815 if (lease->address.len == sizeof(client->packet.yiaddr) && 816 !memcmp(lease->address.iabuf, 817 &client->packet.yiaddr, lease->address.len)) { 818 #ifdef DEBUG 819 debug("%s already seen.", name); 820 #endif 821 return; 822 } 823 } 824 825 lease = packet_to_lease(options); 826 if (!lease) { 827 note("packet_to_lease failed."); 828 return; 829 } 830 831 /* 832 * Reject offers whose subnet is already configured on another 833 * interface. 834 */ 835 if (subnet_exists(lease)) 836 return; 837 838 /* If this lease was acquired through a BOOTREPLY, record that 839 fact. */ 840 if (!options[DHO_DHCP_MESSAGE_TYPE].len) 841 lease->is_bootp = 1; 842 843 /* Figure out when we're supposed to stop selecting. */ 844 stop_selecting = client->first_sending + config->select_interval; 845 846 /* If this is the lease we asked for, put it at the head of the 847 list, and don't mess with the arp request timeout. */ 848 if (addr_eq(lease->address, client->requested_address)) { 849 lease->next = client->offered_leases; 850 client->offered_leases = lease; 851 } else { 852 /* Put the lease at the end of the list. */ 853 lease->next = NULL; 854 if (!client->offered_leases) 855 client->offered_leases = lease; 856 else { 857 for (lp = client->offered_leases; lp->next; 858 lp = lp->next) 859 ; /* nothing */ 860 lp->next = lease; 861 } 862 } 863 864 /* If the selecting interval has expired, go immediately to 865 state_selecting(). Otherwise, time out into 866 state_selecting at the select interval. */ 867 if (stop_selecting <= time(NULL)) 868 state_selecting(); 869 else { 870 set_timeout(stop_selecting, state_selecting); 871 } 872 } 873 874 /* 875 * Allocate a client_lease structure and initialize it from the 876 * parameters in the specified packet. 877 */ 878 struct client_lease * 879 packet_to_lease(struct option_data *options) 880 { 881 struct client_lease *lease; 882 int i; 883 884 lease = malloc(sizeof(struct client_lease)); 885 886 if (!lease) { 887 warning("dhcpoffer: no memory to record lease."); 888 return (NULL); 889 } 890 891 memset(lease, 0, sizeof(*lease)); 892 893 /* Copy the lease options. */ 894 for (i = 0; i < 256; i++) { 895 if (options[i].len) { 896 lease->options[i] = options[i]; 897 options[i].data = NULL; 898 options[i].len = 0; 899 if (!check_option(lease, i)) { 900 warning("Invalid lease option - ignoring offer"); 901 free_client_lease(lease); 902 return (NULL); 903 } 904 } 905 } 906 907 lease->address.len = sizeof(client->packet.yiaddr); 908 memcpy(lease->address.iabuf, &client->packet.yiaddr, 909 lease->address.len); 910 911 /* If the server name was filled out, copy it. */ 912 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len || 913 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) && 914 client->packet.sname[0]) { 915 lease->server_name = malloc(DHCP_SNAME_LEN + 1); 916 if (!lease->server_name) { 917 warning("dhcpoffer: no memory for server name."); 918 free_client_lease(lease); 919 return (NULL); 920 } 921 memcpy(lease->server_name, client->packet.sname, 922 DHCP_SNAME_LEN); 923 lease->server_name[DHCP_SNAME_LEN] = '\0'; 924 if (!res_hnok(lease->server_name)) { 925 warning("Bogus server name %s", lease->server_name); 926 free(lease->server_name); 927 lease->server_name = NULL; 928 } 929 } 930 931 /* Ditto for the filename. */ 932 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len || 933 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) && 934 client->packet.file[0]) { 935 /* Don't count on the NUL terminator. */ 936 lease->filename = malloc(DHCP_FILE_LEN + 1); 937 if (!lease->filename) { 938 warning("dhcpoffer: no memory for filename."); 939 free_client_lease(lease); 940 return (NULL); 941 } 942 memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN); 943 lease->filename[DHCP_FILE_LEN] = '\0'; 944 } 945 return lease; 946 } 947 948 void 949 dhcpnak(struct iaddr client_addr, struct option_data *options) 950 { 951 952 if (client->state != S_REBOOTING && 953 client->state != S_REQUESTING && 954 client->state != S_RENEWING && 955 client->state != S_REBINDING) 956 return; 957 958 959 if (!client->active) { 960 note("DHCPNAK with no active lease."); 961 return; 962 } 963 964 free_client_lease(client->active); 965 client->active = NULL; 966 967 /* Stop sending DHCPREQUEST packets... */ 968 cancel_timeout(); 969 970 client->state = S_INIT; 971 state_init(); 972 } 973 974 /* 975 * Send out a DHCPDISCOVER packet, and set a timeout to send out another 976 * one after the right interval has expired. If we don't get an offer by 977 * the time we reach the panic interval, call the panic function. 978 */ 979 void 980 send_discover(void) 981 { 982 time_t cur_time; 983 int interval, increase = 1; 984 985 time(&cur_time); 986 987 /* Figure out how long it's been since we started transmitting. */ 988 interval = cur_time - client->first_sending; 989 990 /* If we're past the panic timeout, call the script and tell it 991 we haven't found anything for this interface yet. */ 992 if (interval > config->timeout) { 993 state_panic(); 994 return; 995 } 996 997 /* 998 * If we're supposed to increase the interval, do so. If it's 999 * currently zero (i.e., we haven't sent any packets yet), set 1000 * it to initial_interval; otherwise, add to it a random 1001 * number between zero and two times itself. On average, this 1002 * means that it will double with every transmission. 1003 */ 1004 if (increase) { 1005 if (!client->interval) 1006 client->interval = config->initial_interval; 1007 else { 1008 client->interval += (arc4random() >> 2) % 1009 (2 * client->interval); 1010 } 1011 1012 /* Don't backoff past cutoff. */ 1013 if (client->interval > config->backoff_cutoff) 1014 client->interval = ((config->backoff_cutoff / 2) 1015 + ((arc4random() >> 2) % 1016 config->backoff_cutoff)); 1017 } else if (!client->interval) 1018 client->interval = config->initial_interval; 1019 1020 /* If the backoff would take us to the panic timeout, just use that 1021 as the interval. */ 1022 if (cur_time + client->interval > 1023 client->first_sending + config->timeout) 1024 client->interval = (client->first_sending + 1025 config->timeout) - cur_time + 1; 1026 1027 /* Record the number of seconds since we started sending. */ 1028 if (interval < 65536) 1029 client->packet.secs = htons(interval); 1030 else 1031 client->packet.secs = htons(65535); 1032 client->secs = client->packet.secs; 1033 1034 note("DHCPDISCOVER on %s to %s port %d interval %ld", 1035 ifi->name, inet_ntoa(sockaddr_broadcast.sin_addr), 1036 ntohs(sockaddr_broadcast.sin_port), client->interval); 1037 1038 send_packet(inaddr_any, &sockaddr_broadcast, NULL); 1039 1040 set_timeout_interval(client->interval, send_discover); 1041 } 1042 1043 /* 1044 * state_panic gets called if we haven't received any offers in a preset 1045 * amount of time. When this happens, we try to use existing leases 1046 * that haven't yet expired, and failing that, we call the client script 1047 * and hope it can do something. 1048 */ 1049 void 1050 state_panic(void) 1051 { 1052 struct client_lease *loop = client->active; 1053 struct client_lease *lp; 1054 time_t cur_time; 1055 1056 note("No DHCPOFFERS received."); 1057 1058 /* We may not have an active lease, but we may have some 1059 predefined leases that we can try. */ 1060 if (!client->active && client->leases) 1061 goto activate_next; 1062 1063 /* Run through the list of leases and see if one can be used. */ 1064 time(&cur_time); 1065 while (client->active) { 1066 if (client->active->expiry > cur_time) { 1067 note("Trying recorded lease %s", 1068 piaddr(client->active->address)); 1069 /* Run the client script with the existing 1070 parameters. */ 1071 script_init("TIMEOUT"); 1072 script_write_params("new_", client->active); 1073 1074 /* If the old lease is still good and doesn't 1075 yet need renewal, go into BOUND state and 1076 timeout at the renewal time. */ 1077 if (!script_go()) { 1078 if (cur_time < client->active->renewal) { 1079 client->state = S_BOUND; 1080 note("bound: renewal in %lld seconds.", 1081 (long long)(client->active->renewal 1082 - cur_time)); 1083 set_timeout(client->active->renewal, 1084 state_bound); 1085 } else { 1086 client->state = S_BOUND; 1087 note("bound: immediate renewal."); 1088 state_bound(); 1089 } 1090 return; 1091 } 1092 } 1093 1094 /* If there are no other leases, give up. */ 1095 if (!client->leases) { 1096 client->leases = client->active; 1097 client->active = NULL; 1098 break; 1099 } 1100 1101 activate_next: 1102 /* Otherwise, put the active lease at the end of the 1103 lease list, and try another lease.. */ 1104 for (lp = client->leases; lp->next; lp = lp->next) 1105 ; 1106 lp->next = client->active; 1107 if (lp->next) 1108 lp->next->next = NULL; 1109 client->active = client->leases; 1110 client->leases = client->leases->next; 1111 1112 /* If we already tried this lease, we've exhausted the 1113 set of leases, so we might as well give up for 1114 now. */ 1115 if (client->active == loop) 1116 break; 1117 else if (!loop) 1118 loop = client->active; 1119 } 1120 1121 /* No leases were available, or what was available didn't work, so 1122 tell the shell script that we failed to allocate an address, 1123 and try again later. */ 1124 note("No working leases in persistent database - sleeping."); 1125 script_init("FAIL"); 1126 script_go(); 1127 client->state = S_INIT; 1128 set_timeout_interval(config->retry_interval, state_init); 1129 } 1130 1131 void 1132 send_request(void) 1133 { 1134 struct sockaddr_in destination; 1135 struct in_addr from; 1136 time_t cur_time; 1137 int interval; 1138 1139 time(&cur_time); 1140 1141 /* Figure out how long it's been since we started transmitting. */ 1142 interval = (int)(cur_time - client->first_sending); 1143 1144 /* If we're in the INIT-REBOOT or REQUESTING state and we're 1145 past the reboot timeout, go to INIT and see if we can 1146 DISCOVER an address... */ 1147 /* XXX In the INIT-REBOOT state, if we don't get an ACK, it 1148 means either that we're on a network with no DHCP server, 1149 or that our server is down. In the latter case, assuming 1150 that there is a backup DHCP server, DHCPDISCOVER will get 1151 us a new address, but we could also have successfully 1152 reused our old address. In the former case, we're hosed 1153 anyway. This is not a win-prone situation. */ 1154 if ((client->state == S_REBOOTING || 1155 client->state == S_REQUESTING) && 1156 interval > config->reboot_timeout) { 1157 client->state = S_INIT; 1158 cancel_timeout(); 1159 state_init(); 1160 return; 1161 } 1162 1163 /* If the lease has expired, relinquish the address and go back 1164 to the INIT state. */ 1165 if (client->state != S_REQUESTING && 1166 cur_time > client->active->expiry) { 1167 /* Run the client script with the new parameters. */ 1168 script_init("EXPIRE"); 1169 script_write_params("old_", client->active); 1170 script_go(); 1171 1172 client->state = S_INIT; 1173 state_init(); 1174 return; 1175 } 1176 1177 /* Do the exponential backoff... */ 1178 if (!client->interval) 1179 client->interval = config->initial_interval; 1180 else 1181 client->interval += ((arc4random() >> 2) % 1182 (2 * client->interval)); 1183 1184 /* Don't backoff past cutoff. */ 1185 if (client->interval > config->backoff_cutoff) 1186 client->interval = ((config->backoff_cutoff / 2) + 1187 ((arc4random() >> 2) % client->interval)); 1188 1189 /* If the backoff would take us to the expiry time, just set the 1190 timeout to the expiry time. */ 1191 if (client->state != S_REQUESTING && cur_time + client->interval > 1192 client->active->expiry) 1193 client->interval = client->active->expiry - cur_time + 1; 1194 1195 /* If the lease T2 time has elapsed, or if we're not yet bound, 1196 broadcast the DHCPREQUEST rather than unicasting. */ 1197 memset(&destination, 0, sizeof(destination)); 1198 if (client->state == S_REQUESTING || 1199 client->state == S_REBOOTING || 1200 cur_time > client->active->rebind) 1201 destination.sin_addr.s_addr = INADDR_BROADCAST; 1202 else 1203 memcpy(&destination.sin_addr.s_addr, client->destination.iabuf, 1204 sizeof(destination.sin_addr.s_addr)); 1205 destination.sin_port = htons(REMOTE_PORT); 1206 destination.sin_family = AF_INET; 1207 destination.sin_len = sizeof(destination); 1208 1209 if (client->state != S_REQUESTING) 1210 memcpy(&from, client->active->address.iabuf, sizeof(from)); 1211 else 1212 from.s_addr = INADDR_ANY; 1213 1214 /* Record the number of seconds since we started sending. */ 1215 if (client->state == S_REQUESTING) 1216 client->packet.secs = client->secs; 1217 else { 1218 if (interval < 65536) 1219 client->packet.secs = htons(interval); 1220 else 1221 client->packet.secs = htons(65535); 1222 } 1223 1224 note("DHCPREQUEST on %s to %s port %d", ifi->name, 1225 inet_ntoa(destination.sin_addr), ntohs(destination.sin_port)); 1226 1227 send_packet(from, &destination, NULL); 1228 1229 set_timeout_interval(client->interval, send_request); 1230 } 1231 1232 void 1233 send_decline(void) 1234 { 1235 note("DHCPDECLINE on %s to %s port %d", ifi->name, 1236 inet_ntoa(sockaddr_broadcast.sin_addr), 1237 ntohs(sockaddr_broadcast.sin_port)); 1238 1239 send_packet(inaddr_any, &sockaddr_broadcast, NULL); 1240 } 1241 1242 void 1243 make_discover(struct client_lease *lease) 1244 { 1245 unsigned char discover = DHCPDISCOVER; 1246 struct option_data options[256]; 1247 int i; 1248 1249 memset(options, 0, sizeof(options)); 1250 memset(&client->packet, 0, sizeof(client->packet)); 1251 1252 /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */ 1253 i = DHO_DHCP_MESSAGE_TYPE; 1254 options[i].data = &discover; 1255 options[i].len = sizeof(discover); 1256 1257 /* Request the options we want */ 1258 i = DHO_DHCP_PARAMETER_REQUEST_LIST; 1259 options[i].data = config->requested_options; 1260 options[i].len = config->requested_option_count; 1261 1262 /* If we had an address, try to get it again. */ 1263 if (lease) { 1264 client->requested_address = lease->address; 1265 i = DHO_DHCP_REQUESTED_ADDRESS; 1266 options[i].data = lease->address.iabuf; 1267 options[i].len = lease->address.len; 1268 } else 1269 client->requested_address.len = 0; 1270 1271 /* Send any options requested in the config file. */ 1272 for (i = 0; i < 256; i++) 1273 if (!options[i].data && 1274 config->send_options[i].data) { 1275 options[i].data = config->send_options[i].data; 1276 options[i].len = config->send_options[i].len; 1277 } 1278 1279 /* Set up the option buffer to fit in a minimal UDP packet. */ 1280 i = cons_options(options); 1281 if (i == -1 || client->packet.options[i] != DHO_END) 1282 error("options do not fit in DHCPDISCOVER packet."); 1283 client->packet_length = DHCP_FIXED_NON_UDP+i+1; 1284 if (client->packet_length < BOOTP_MIN_LEN) 1285 client->packet_length = BOOTP_MIN_LEN; 1286 1287 client->packet.op = BOOTREQUEST; 1288 client->packet.htype = ifi->hw_address.htype; 1289 client->packet.hlen = ifi->hw_address.hlen; 1290 client->packet.hops = 0; 1291 client->packet.xid = arc4random(); 1292 client->packet.secs = 0; /* filled in by send_discover. */ 1293 client->packet.flags = 0; 1294 1295 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr)); 1296 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr)); 1297 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr)); 1298 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr)); 1299 memcpy(client->packet.chaddr, ifi->hw_address.haddr, 1300 ifi->hw_address.hlen); 1301 } 1302 1303 void 1304 make_request(struct client_lease * lease) 1305 { 1306 unsigned char request = DHCPREQUEST; 1307 struct option_data options[256]; 1308 int i; 1309 1310 memset(options, 0, sizeof(options)); 1311 memset(&client->packet, 0, sizeof(client->packet)); 1312 1313 /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */ 1314 i = DHO_DHCP_MESSAGE_TYPE; 1315 options[i].data = &request; 1316 options[i].len = sizeof(request); 1317 1318 /* Request the options we want */ 1319 i = DHO_DHCP_PARAMETER_REQUEST_LIST; 1320 options[i].data = config->requested_options; 1321 options[i].len = config->requested_option_count; 1322 1323 /* If we are requesting an address that hasn't yet been assigned 1324 to us, use the DHCP Requested Address option. */ 1325 if (client->state == S_REQUESTING) { 1326 /* Send back the server identifier... */ 1327 i = DHO_DHCP_SERVER_IDENTIFIER; 1328 options[i].data = lease->options[i].data; 1329 options[i].len = lease->options[i].len; 1330 } 1331 if (client->state == S_REQUESTING || 1332 client->state == S_REBOOTING) { 1333 client->requested_address = lease->address; 1334 i = DHO_DHCP_REQUESTED_ADDRESS; 1335 options[i].data = lease->address.iabuf; 1336 options[i].len = lease->address.len; 1337 } else 1338 client->requested_address.len = 0; 1339 1340 /* Send any options requested in the config file. */ 1341 for (i = 0; i < 256; i++) 1342 if (!options[i].data && config->send_options[i].data) { 1343 options[i].data = config->send_options[i].data; 1344 options[i].len = config->send_options[i].len; 1345 } 1346 1347 /* Set up the option buffer to fit in a minimal UDP packet. */ 1348 i = cons_options(options); 1349 if (i == -1 || client->packet.options[i] != DHO_END) 1350 error("options do not fit in DHCPREQUEST packet."); 1351 client->packet_length = DHCP_FIXED_NON_UDP+i+1; 1352 if (client->packet_length < BOOTP_MIN_LEN) 1353 client->packet_length = BOOTP_MIN_LEN; 1354 1355 client->packet.op = BOOTREQUEST; 1356 client->packet.htype = ifi->hw_address.htype; 1357 client->packet.hlen = ifi->hw_address.hlen; 1358 client->packet.hops = 0; 1359 client->packet.xid = client->xid; 1360 client->packet.secs = 0; /* Filled in by send_request. */ 1361 client->packet.flags = 0; 1362 1363 /* If we own the address we're requesting, put it in ciaddr; 1364 otherwise set ciaddr to zero. */ 1365 if (client->state == S_BOUND || 1366 client->state == S_RENEWING || 1367 client->state == S_REBINDING) { 1368 memcpy(&client->packet.ciaddr, 1369 lease->address.iabuf, lease->address.len); 1370 } else { 1371 memset(&client->packet.ciaddr, 0, 1372 sizeof(client->packet.ciaddr)); 1373 } 1374 1375 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr)); 1376 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr)); 1377 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr)); 1378 memcpy(client->packet.chaddr, ifi->hw_address.haddr, 1379 ifi->hw_address.hlen); 1380 } 1381 1382 void 1383 make_decline(struct client_lease *lease) 1384 { 1385 struct option_data options[256]; 1386 unsigned char decline = DHCPDECLINE; 1387 int i; 1388 1389 memset(options, 0, sizeof(options)); 1390 memset(&client->packet, 0, sizeof(client->packet)); 1391 1392 /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */ 1393 i = DHO_DHCP_MESSAGE_TYPE; 1394 options[i].data = &decline; 1395 options[i].len = sizeof(decline); 1396 1397 /* Send back the server identifier... */ 1398 i = DHO_DHCP_SERVER_IDENTIFIER; 1399 options[i].data = lease->options[i].data; 1400 options[i].len = lease->options[i].len; 1401 1402 /* Send back the address we're declining. */ 1403 i = DHO_DHCP_REQUESTED_ADDRESS; 1404 options[i].data = lease->address.iabuf; 1405 options[i].len = lease->address.len; 1406 1407 /* Send the uid if the user supplied one. */ 1408 i = DHO_DHCP_CLIENT_IDENTIFIER; 1409 if (config->send_options[i].len) { 1410 options[i].data = config->send_options[i].data; 1411 options[i].len = config->send_options[i].len; 1412 } 1413 1414 /* Set up the option buffer to fit in a minimal UDP packet. */ 1415 i = cons_options(options); 1416 if (i == -1 || client->packet.options[i] != DHO_END) 1417 error("options do not fit in DHCPDECLINE packet."); 1418 client->packet_length = DHCP_FIXED_NON_UDP+i+1; 1419 if (client->packet_length < BOOTP_MIN_LEN) 1420 client->packet_length = BOOTP_MIN_LEN; 1421 1422 client->packet.op = BOOTREQUEST; 1423 client->packet.htype = ifi->hw_address.htype; 1424 client->packet.hlen = ifi->hw_address.hlen; 1425 client->packet.hops = 0; 1426 client->packet.xid = client->xid; 1427 client->packet.secs = 0; /* Filled in by send_request. */ 1428 client->packet.flags = 0; 1429 1430 /* ciaddr must always be zero. */ 1431 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr)); 1432 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr)); 1433 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr)); 1434 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr)); 1435 memcpy(client->packet.chaddr, ifi->hw_address.haddr, 1436 ifi->hw_address.hlen); 1437 } 1438 1439 void 1440 free_client_lease(struct client_lease *lease) 1441 { 1442 int i; 1443 1444 if (lease->server_name) 1445 free(lease->server_name); 1446 if (lease->filename) 1447 free(lease->filename); 1448 for (i = 0; i < 256; i++) { 1449 if (lease->options[i].len) 1450 free(lease->options[i].data); 1451 } 1452 free(lease); 1453 } 1454 1455 void 1456 rewrite_client_leases(void) 1457 { 1458 struct client_lease *lp; 1459 1460 if (!leaseFile) /* XXX */ 1461 error("lease file not open"); 1462 1463 fflush(leaseFile); 1464 rewind(leaseFile); 1465 1466 for (lp = client->leases; lp; lp = lp->next) { 1467 if (client->active && addr_eq(lp->address, 1468 client->active->address)) 1469 continue; 1470 write_client_lease(lp); 1471 } 1472 1473 if (client->active) 1474 write_client_lease(client->active); 1475 1476 fflush(leaseFile); 1477 ftruncate(fileno(leaseFile), ftello(leaseFile)); 1478 fsync(fileno(leaseFile)); 1479 } 1480 1481 void 1482 write_client_lease(struct client_lease *lease) 1483 { 1484 struct tm *t; 1485 int i; 1486 1487 /* If the lease came from the config file, we don't need to stash 1488 a copy in the lease database. */ 1489 if (lease->is_static) 1490 return; 1491 1492 if (!leaseFile) /* XXX */ 1493 error("lease file not open"); 1494 1495 fprintf(leaseFile, "lease {\n"); 1496 if (lease->is_bootp) 1497 fprintf(leaseFile, " bootp;\n"); 1498 fprintf(leaseFile, " interface \"%s\";\n", ifi->name); 1499 fprintf(leaseFile, " fixed-address %s;\n", piaddr(lease->address)); 1500 if (lease->filename) 1501 fprintf(leaseFile, " filename \"%s\";\n", lease->filename); 1502 if (lease->server_name) 1503 fprintf(leaseFile, " server-name \"%s\";\n", 1504 lease->server_name); 1505 for (i = 0; i < 256; i++) 1506 if (lease->options[i].len) 1507 fprintf(leaseFile, " option %s %s;\n", 1508 dhcp_options[i].name, 1509 pretty_print_option(i, &lease->options[i], 1)); 1510 1511 t = gmtime(&lease->renewal); 1512 fprintf(leaseFile, " renew %d %d/%d/%d %02d:%02d:%02d;\n", 1513 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, 1514 t->tm_hour, t->tm_min, t->tm_sec); 1515 t = gmtime(&lease->rebind); 1516 fprintf(leaseFile, " rebind %d %d/%d/%d %02d:%02d:%02d;\n", 1517 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, 1518 t->tm_hour, t->tm_min, t->tm_sec); 1519 t = gmtime(&lease->expiry); 1520 fprintf(leaseFile, " expire %d %d/%d/%d %02d:%02d:%02d;\n", 1521 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, 1522 t->tm_hour, t->tm_min, t->tm_sec); 1523 fprintf(leaseFile, "}\n"); 1524 fflush(leaseFile); 1525 } 1526 1527 void 1528 script_init(char *reason) 1529 { 1530 size_t len; 1531 struct imsg_hdr hdr; 1532 struct buf *buf; 1533 1534 hdr.code = IMSG_SCRIPT_INIT; 1535 hdr.len = sizeof(struct imsg_hdr) + sizeof(size_t) + strlen(reason); 1536 buf = buf_open(hdr.len); 1537 1538 buf_add(buf, &hdr, sizeof(hdr)); 1539 len = strlen(reason); 1540 buf_add(buf, &len, sizeof(len)); 1541 buf_add(buf, reason, len); 1542 1543 buf_close(privfd, buf); 1544 } 1545 1546 void 1547 priv_script_init(char *reason) 1548 { 1549 client->scriptEnvsize = 100; 1550 if (client->scriptEnv == NULL) 1551 client->scriptEnv = 1552 calloc(client->scriptEnvsize, sizeof(char *)); 1553 if (client->scriptEnv == NULL) 1554 error("script_init: no memory for environment"); 1555 1556 client->scriptEnv[0] = strdup(CLIENT_PATH); 1557 if (client->scriptEnv[0] == NULL) 1558 error("script_init: no memory for environment"); 1559 1560 client->scriptEnv[1] = NULL; 1561 1562 script_set_env("", "interface", ifi->name); 1563 1564 script_set_env("", "reason", reason); 1565 } 1566 1567 void 1568 priv_script_write_params(char *prefix, struct client_lease *lease) 1569 { 1570 char buf[256]; 1571 struct option_data o; 1572 int i; 1573 1574 script_set_env(prefix, "ip_address", piaddr(lease->address)); 1575 1576 if (lease->options[DHO_SUBNET_MASK].len && 1577 (lease->options[DHO_SUBNET_MASK].len < 1578 sizeof(lease->address.iabuf))) { 1579 struct iaddr netmask, subnet, broadcast; 1580 1581 memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data, 1582 lease->options[DHO_SUBNET_MASK].len); 1583 netmask.len = lease->options[DHO_SUBNET_MASK].len; 1584 1585 subnet = subnet_number(lease->address, netmask); 1586 if (subnet.len) { 1587 script_set_env(prefix, "network_number", 1588 piaddr(subnet)); 1589 if (!lease->options[DHO_BROADCAST_ADDRESS].len) { 1590 broadcast = broadcast_addr(subnet, netmask); 1591 if (broadcast.len) 1592 script_set_env(prefix, 1593 "broadcast_address", 1594 piaddr(broadcast)); 1595 } 1596 } 1597 } 1598 1599 if (lease->filename) 1600 script_set_env(prefix, "filename", lease->filename); 1601 if (lease->server_name) 1602 script_set_env(prefix, "server_name", 1603 lease->server_name); 1604 1605 for (i = 0; i < 256; i++) { 1606 if (!dhcp_option_ev_name(buf, sizeof(buf), &dhcp_options[i])) 1607 continue; 1608 1609 switch (config->default_actions[i]) { 1610 case ACTION_IGNORE: 1611 break; 1612 1613 case ACTION_DEFAULT: 1614 if (lease->options[i].len) 1615 script_set_env(prefix, buf, 1616 pretty_print_option(i, &lease->options[i], 1617 0)); 1618 else if (config->defaults[i].len) 1619 script_set_env(prefix, buf, 1620 pretty_print_option(i, &config->defaults[i], 1621 0)); 1622 break; 1623 1624 case ACTION_SUPERSEDE: 1625 if (config->defaults[i].len) 1626 script_set_env(prefix, buf, 1627 pretty_print_option(i, &config->defaults[i], 1628 0)); 1629 break; 1630 1631 case ACTION_PREPEND: 1632 o.len = config->defaults[i].len + lease->options[i].len; 1633 if (o.len > 0) { 1634 o.data = calloc(1, o.len); 1635 if (o.data == NULL) 1636 error("no space to prepend '%s' to %s", 1637 config->defaults[i].data, 1638 dhcp_options[i].name); 1639 memcpy(o.data, config->defaults[i].data, 1640 config->defaults[i].len); 1641 memcpy(o.data + config->defaults[i].len, 1642 lease->options[i].data, 1643 lease->options[i].len); 1644 script_set_env(prefix, buf, 1645 pretty_print_option(i, &o, 0)); 1646 free(o.data); 1647 } 1648 break; 1649 1650 case ACTION_APPEND: 1651 o.len = config->defaults[i].len + lease->options[i].len; 1652 if (o.len > 0) { 1653 o.data = calloc(1, o.len); 1654 if (o.data == NULL) 1655 error("no space to append '%s' to %s", 1656 config->defaults[i].data, 1657 dhcp_options[i].name); 1658 memcpy(o.data, lease->options[i].data, 1659 lease->options[i].len); 1660 memcpy(o.data + lease->options[i].len, 1661 config->defaults[i].data, 1662 config->defaults[i].len); 1663 script_set_env(prefix, buf, 1664 pretty_print_option(i, &o, 0)); 1665 free(o.data); 1666 } 1667 break; 1668 } 1669 } 1670 1671 snprintf(buf, sizeof(buf), "%d", (int)lease->expiry); 1672 script_set_env(prefix, "expiry", buf); 1673 } 1674 1675 void 1676 script_write_params(char *prefix, struct client_lease *lease) 1677 { 1678 size_t fn_len = 0, sn_len = 0, pr_len = 0; 1679 struct imsg_hdr hdr; 1680 struct buf *buf; 1681 int i; 1682 1683 if (lease->filename != NULL) 1684 fn_len = strlen(lease->filename); 1685 if (lease->server_name != NULL) 1686 sn_len = strlen(lease->server_name); 1687 if (prefix != NULL) 1688 pr_len = strlen(prefix); 1689 1690 hdr.code = IMSG_SCRIPT_WRITE_PARAMS; 1691 hdr.len = sizeof(hdr) + sizeof(struct client_lease) + 1692 sizeof(size_t) + fn_len + sizeof(size_t) + sn_len + 1693 sizeof(size_t) + pr_len; 1694 1695 for (i = 0; i < 256; i++) 1696 hdr.len += sizeof(int) + lease->options[i].len; 1697 1698 scripttime = time(NULL); 1699 1700 buf = buf_open(hdr.len); 1701 1702 buf_add(buf, &hdr, sizeof(hdr)); 1703 buf_add(buf, lease, sizeof(struct client_lease)); 1704 buf_add(buf, &fn_len, sizeof(fn_len)); 1705 buf_add(buf, lease->filename, fn_len); 1706 buf_add(buf, &sn_len, sizeof(sn_len)); 1707 buf_add(buf, lease->server_name, sn_len); 1708 buf_add(buf, &pr_len, sizeof(pr_len)); 1709 buf_add(buf, prefix, pr_len); 1710 1711 for (i = 0; i < 256; i++) { 1712 buf_add(buf, &lease->options[i].len, 1713 sizeof(lease->options[i].len)); 1714 buf_add(buf, lease->options[i].data, 1715 lease->options[i].len); 1716 } 1717 1718 buf_close(privfd, buf); 1719 } 1720 1721 int 1722 script_go(void) 1723 { 1724 struct imsg_hdr hdr; 1725 struct buf *buf; 1726 int ret; 1727 1728 scripttime = time(NULL); 1729 1730 hdr.code = IMSG_SCRIPT_GO; 1731 hdr.len = sizeof(struct imsg_hdr); 1732 1733 buf = buf_open(hdr.len); 1734 1735 buf_add(buf, &hdr, sizeof(hdr)); 1736 buf_close(privfd, buf); 1737 1738 bzero(&hdr, sizeof(hdr)); 1739 buf_read(privfd, &hdr, sizeof(hdr)); 1740 if (hdr.code != IMSG_SCRIPT_GO_RET) 1741 error("unexpected msg type %u", hdr.code); 1742 if (hdr.len != sizeof(hdr) + sizeof(int)) 1743 error("received corrupted message"); 1744 buf_read(privfd, &ret, sizeof(ret)); 1745 1746 return (ret); 1747 } 1748 1749 int 1750 priv_script_go(void) 1751 { 1752 char *scriptName, *argv[2], **envp; 1753 int pid, wpid, wstatus; 1754 1755 scripttime = time(NULL); 1756 1757 scriptName = config->script_name; 1758 envp = client->scriptEnv; 1759 1760 argv[0] = scriptName; 1761 argv[1] = NULL; 1762 1763 pid = fork(); 1764 if (pid < 0) { 1765 error("fork: %m"); 1766 } else if (pid) { 1767 do { 1768 wpid = wait(&wstatus); 1769 } while (wpid != pid && wpid > 0); 1770 if (wpid < 0) { 1771 error("wait: %m"); 1772 } 1773 } else { 1774 execve(scriptName, argv, envp); 1775 error("execve (%s, ...): %m", scriptName); 1776 } 1777 1778 script_flush_env(); 1779 1780 return (WEXITSTATUS(wstatus)); 1781 } 1782 1783 void 1784 script_set_env(const char *prefix, const char *name, const char *value) 1785 { 1786 int i, j, namelen; 1787 1788 /* No `` or $() command substitution allowed in environment values! */ 1789 for (j = 0; j < strlen(value); j++) 1790 switch (value[j]) { 1791 case '`': 1792 case '$': 1793 warning("illegal character (%c) in value '%s'", 1794 value[j], value); 1795 /* Ignore this option */ 1796 return; 1797 } 1798 1799 namelen = strlen(name); 1800 1801 for (i = 0; client->scriptEnv[i]; i++) 1802 if (strncmp(client->scriptEnv[i], name, namelen) == 0 && 1803 client->scriptEnv[i][namelen] == '=') 1804 break; 1805 1806 if (client->scriptEnv[i]) 1807 /* Reuse the slot. */ 1808 free(client->scriptEnv[i]); 1809 else { 1810 /* New variable. Expand if necessary. */ 1811 if (i >= client->scriptEnvsize - 1) { 1812 char **newscriptEnv; 1813 int newscriptEnvsize = client->scriptEnvsize + 50; 1814 1815 newscriptEnv = realloc(client->scriptEnv, 1816 newscriptEnvsize); 1817 if (newscriptEnv == NULL) { 1818 free(client->scriptEnv); 1819 client->scriptEnv = NULL; 1820 client->scriptEnvsize = 0; 1821 error("script_set_env: no memory for variable"); 1822 } 1823 client->scriptEnv = newscriptEnv; 1824 client->scriptEnvsize = newscriptEnvsize; 1825 } 1826 /* need to set the NULL pointer at end of array beyond 1827 the new slot. */ 1828 client->scriptEnv[i + 1] = NULL; 1829 } 1830 /* Allocate space and format the variable in the appropriate slot. */ 1831 client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 + 1832 strlen(value) + 1); 1833 if (client->scriptEnv[i] == NULL) 1834 error("script_set_env: no memory for variable assignment"); 1835 snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) + 1836 1 + strlen(value) + 1, "%s%s=%s", prefix, name, value); 1837 } 1838 1839 void 1840 script_flush_env(void) 1841 { 1842 int i; 1843 1844 for (i = 0; client->scriptEnv[i]; i++) { 1845 free(client->scriptEnv[i]); 1846 client->scriptEnv[i] = NULL; 1847 } 1848 client->scriptEnvsize = 0; 1849 } 1850 1851 int 1852 dhcp_option_ev_name(char *buf, size_t buflen, const struct option *option) 1853 { 1854 size_t i; 1855 1856 for (i = 0; option->name[i]; i++) { 1857 if (i + 1 == buflen) 1858 return 0; 1859 if (option->name[i] == '-') 1860 buf[i] = '_'; 1861 else 1862 buf[i] = option->name[i]; 1863 } 1864 1865 buf[i] = 0; 1866 return 1; 1867 } 1868 1869 void 1870 go_daemon(void) 1871 { 1872 char buf[256]; 1873 int fd; 1874 1875 /* 1876 * Only once 1877 */ 1878 if (no_daemon == 2) 1879 return; 1880 1881 /* 1882 * Setup pidfile, kill any dhclient already running for this 1883 * interface. 1884 */ 1885 snprintf(buf, sizeof(buf), "/var/run/dhclient.%s.pid", orig_ifname); 1886 fd = open(buf, O_RDWR|O_CREAT, 0644); 1887 if (fd >= 0) { 1888 if (killclient(fd)) { 1889 fprintf(stderr, 1890 "starting dhclient on %s\n", 1891 orig_ifname); 1892 } else { 1893 fprintf(stderr, 1894 "restarting dhclient on %s\n", 1895 orig_ifname); 1896 } 1897 } 1898 1899 /* 1900 * Daemonize if requested 1901 */ 1902 if (no_daemon == 0) { 1903 /* Stop logging to stderr... */ 1904 log_perror = 0; 1905 1906 if (daemon(1, 0) == -1) 1907 error("daemon"); 1908 1909 /* we are chrooted, daemon(3) fails to open /dev/null */ 1910 if (nullfd != -1) { 1911 dup2(nullfd, STDIN_FILENO); 1912 dup2(nullfd, STDOUT_FILENO); 1913 dup2(nullfd, STDERR_FILENO); 1914 close(nullfd); 1915 nullfd = -1; 1916 } 1917 } 1918 1919 /* 1920 * No further daemonizations, write out pid file and lock. 1921 */ 1922 no_daemon = 2; 1923 if (fd >= 0) { 1924 lseek(fd, 0L, SEEK_SET); 1925 ftruncate(fd, 0); 1926 snprintf(buf, sizeof(buf), "%ld\n", (long)getpid()); 1927 write(fd, buf, strlen(buf)); 1928 flock(fd, LOCK_EX); 1929 /* leave descriptor open and locked */ 1930 } 1931 } 1932 1933 int 1934 check_option(struct client_lease *l, int option) 1935 { 1936 char *opbuf; 1937 char *sbuf; 1938 1939 /* we use this, since this is what gets passed to dhclient-script */ 1940 1941 opbuf = pretty_print_option(option, &l->options[option], 0); 1942 1943 sbuf = option_as_string(option, l->options[option].data, 1944 l->options[option].len); 1945 1946 switch (option) { 1947 case DHO_SUBNET_MASK: 1948 case DHO_SWAP_SERVER: 1949 case DHO_BROADCAST_ADDRESS: 1950 case DHO_DHCP_SERVER_IDENTIFIER: 1951 case DHO_ROUTER_SOLICITATION_ADDRESS: 1952 case DHO_DHCP_REQUESTED_ADDRESS: 1953 if (ipv4addrs(opbuf) == 0) { 1954 warning("Invalid IP address in option %s: %s", 1955 dhcp_options[option].name, opbuf); 1956 return (0); 1957 } 1958 if (l->options[option].len != 4) { /* RFC 2132 */ 1959 warning("warning: Only 1 IP address allowed in " 1960 "%s option; length %d, must be 4", 1961 dhcp_options[option].name, 1962 l->options[option].len); 1963 l->options[option].len = 4; 1964 } 1965 return (1); 1966 case DHO_TIME_SERVERS: 1967 case DHO_NAME_SERVERS: 1968 case DHO_ROUTERS: 1969 case DHO_DOMAIN_NAME_SERVERS: 1970 case DHO_LOG_SERVERS: 1971 case DHO_COOKIE_SERVERS: 1972 case DHO_LPR_SERVERS: 1973 case DHO_IMPRESS_SERVERS: 1974 case DHO_RESOURCE_LOCATION_SERVERS: 1975 case DHO_NIS_SERVERS: 1976 case DHO_NTP_SERVERS: 1977 case DHO_NETBIOS_NAME_SERVERS: 1978 case DHO_NETBIOS_DD_SERVER: 1979 case DHO_FONT_SERVERS: 1980 if (ipv4addrs(opbuf) == 0) { 1981 warning("Invalid IP address in option %s: %s", 1982 dhcp_options[option].name, opbuf); 1983 return (0); 1984 } 1985 return (1); 1986 case DHO_HOST_NAME: 1987 case DHO_DOMAIN_NAME: 1988 case DHO_NIS_DOMAIN: 1989 if (!res_hnok(sbuf)) { 1990 warning("Bogus Host Name option %d: %s (%s)", option, 1991 sbuf, opbuf); 1992 l->options[option].len = 0; 1993 free(l->options[option].data); 1994 } 1995 return (1); 1996 case DHO_PAD: 1997 case DHO_TIME_OFFSET: 1998 case DHO_BOOT_SIZE: 1999 case DHO_MERIT_DUMP: 2000 case DHO_ROOT_PATH: 2001 case DHO_EXTENSIONS_PATH: 2002 case DHO_IP_FORWARDING: 2003 case DHO_NON_LOCAL_SOURCE_ROUTING: 2004 case DHO_POLICY_FILTER: 2005 case DHO_MAX_DGRAM_REASSEMBLY: 2006 case DHO_DEFAULT_IP_TTL: 2007 case DHO_PATH_MTU_AGING_TIMEOUT: 2008 case DHO_PATH_MTU_PLATEAU_TABLE: 2009 case DHO_INTERFACE_MTU: 2010 case DHO_ALL_SUBNETS_LOCAL: 2011 case DHO_PERFORM_MASK_DISCOVERY: 2012 case DHO_MASK_SUPPLIER: 2013 case DHO_ROUTER_DISCOVERY: 2014 case DHO_STATIC_ROUTES: 2015 case DHO_TRAILER_ENCAPSULATION: 2016 case DHO_ARP_CACHE_TIMEOUT: 2017 case DHO_IEEE802_3_ENCAPSULATION: 2018 case DHO_DEFAULT_TCP_TTL: 2019 case DHO_TCP_KEEPALIVE_INTERVAL: 2020 case DHO_TCP_KEEPALIVE_GARBAGE: 2021 case DHO_VENDOR_ENCAPSULATED_OPTIONS: 2022 case DHO_NETBIOS_NODE_TYPE: 2023 case DHO_NETBIOS_SCOPE: 2024 case DHO_X_DISPLAY_MANAGER: 2025 case DHO_DHCP_LEASE_TIME: 2026 case DHO_DHCP_OPTION_OVERLOAD: 2027 case DHO_DHCP_MESSAGE_TYPE: 2028 case DHO_DHCP_PARAMETER_REQUEST_LIST: 2029 case DHO_DHCP_MESSAGE: 2030 case DHO_DHCP_MAX_MESSAGE_SIZE: 2031 case DHO_DHCP_RENEWAL_TIME: 2032 case DHO_DHCP_REBINDING_TIME: 2033 case DHO_DHCP_CLASS_IDENTIFIER: 2034 case DHO_DHCP_CLIENT_IDENTIFIER: 2035 case DHO_DHCP_USER_CLASS_ID: 2036 case DHO_TFTP_SERVER: 2037 case DHO_END: 2038 return (1); 2039 case DHO_CLASSLESS_ROUTES: 2040 return (check_classless_option(l->options[option].data, 2041 l->options[option].len)); 2042 default: 2043 if (!unknown_ok) 2044 warning("unknown dhcp option value 0x%x", option); 2045 return (unknown_ok); 2046 } 2047 } 2048 2049 /* RFC 3442 The Classless Static Routes option checks */ 2050 int 2051 check_classless_option(unsigned char *data, int len) 2052 { 2053 int i = 0; 2054 unsigned char width; 2055 in_addr_t addr, mask; 2056 2057 if (len < 5) { 2058 warning("Too small length: %d", len); 2059 return (0); 2060 } 2061 while(i < len) { 2062 width = data[i++]; 2063 if (width == 0) { 2064 i += 4; 2065 continue; 2066 } else if (width < 9) { 2067 addr = (in_addr_t)(data[i] << 24); 2068 i += 1; 2069 } else if (width < 17) { 2070 addr = (in_addr_t)(data[i] << 24) + 2071 (in_addr_t)(data[i + 1] << 16); 2072 i += 2; 2073 } else if (width < 25) { 2074 addr = (in_addr_t)(data[i] << 24) + 2075 (in_addr_t)(data[i + 1] << 16) + 2076 (in_addr_t)(data[i + 2] << 8); 2077 i += 3; 2078 } else if (width < 33) { 2079 addr = (in_addr_t)(data[i] << 24) + 2080 (in_addr_t)(data[i + 1] << 16) + 2081 (in_addr_t)(data[i + 2] << 8) + 2082 data[i + 3]; 2083 i += 4; 2084 } else { 2085 warning("Incorrect subnet width: %d", width); 2086 return (0); 2087 } 2088 mask = (in_addr_t)(~0) << (32 - width); 2089 addr = ntohl(addr); 2090 mask = ntohl(mask); 2091 2092 /* 2093 * From RFC 3442: 2094 * ... After deriving a subnet number and subnet mask 2095 * from each destination descriptor, the DHCP client 2096 * MUST zero any bits in the subnet number where the 2097 * corresponding bit in the mask is zero... 2098 */ 2099 if ((addr & mask) != addr) { 2100 addr &= mask; 2101 data[i - 1] = (unsigned char)( 2102 (addr >> rounddown(32 - width, 8)) & 0xFF); 2103 } 2104 i += 4; 2105 } 2106 if (i > len) { 2107 warning("Incorrect data length: %d (must be %d)", len, i); 2108 return (0); 2109 } 2110 return (1); 2111 } 2112 2113 int 2114 res_hnok(const char *name) 2115 { 2116 const char *dn = name; 2117 int pch = '.', ch = *dn++; 2118 int warn = 0; 2119 2120 while (ch != '\0') { 2121 int nch = *dn++; 2122 2123 if (ch == '.') { 2124 ; 2125 } else if (pch == '.' || nch == '.' || nch == '\0') { 2126 if (!isalnum(ch)) 2127 return (0); 2128 } else if (!isalnum(ch) && ch != '-' && ch != '_') 2129 return (0); 2130 else if (ch == '_' && warn == 0) { 2131 warning("warning: hostname %s contains an " 2132 "underscore which violates RFC 952", name); 2133 warn++; 2134 } 2135 pch = ch, ch = nch; 2136 } 2137 return (1); 2138 } 2139 2140 /* Does buf consist only of dotted decimal ipv4 addrs? 2141 * return how many if so, 2142 * otherwise, return 0 2143 */ 2144 int 2145 ipv4addrs(char * buf) 2146 { 2147 struct in_addr jnk; 2148 int count = 0; 2149 2150 while (inet_aton(buf, &jnk) == 1){ 2151 count++; 2152 while (*buf == '.' || isdigit(*buf)) 2153 buf++; 2154 if (*buf == '\0') 2155 return (count); 2156 while (*buf == ' ') 2157 buf++; 2158 } 2159 return (0); 2160 } 2161 2162 char * 2163 option_as_string(unsigned int code, unsigned char *data, int len) 2164 { 2165 static char optbuf[32768]; /* XXX */ 2166 char *op = optbuf; 2167 int opleft = sizeof(optbuf); 2168 unsigned char *dp = data; 2169 2170 if (code > 255) 2171 error("option_as_string: bad code %d", code); 2172 2173 for (; dp < data + len; dp++) { 2174 if (!isascii(*dp) || !isprint(*dp)) { 2175 if (dp + 1 != data + len || *dp != 0) { 2176 size_t oplen; 2177 snprintf(op, opleft, "\\%03o", *dp); 2178 oplen = strlen(op); 2179 op += oplen; 2180 opleft -= oplen; 2181 } 2182 } else if (*dp == '"' || *dp == '\'' || *dp == '$' || 2183 *dp == '`' || *dp == '\\') { 2184 *op++ = '\\'; 2185 *op++ = *dp; 2186 opleft -= 2; 2187 } else { 2188 *op++ = *dp; 2189 opleft--; 2190 } 2191 } 2192 if (opleft < 1) 2193 goto toobig; 2194 *op = 0; 2195 return optbuf; 2196 toobig: 2197 warning("dhcp option too large"); 2198 return "<error>"; 2199 } 2200 2201 int 2202 fork_privchld(int fd, int fd2) 2203 { 2204 struct pollfd pfd[1]; 2205 int nfds, pfail = 0; 2206 pid_t pid; 2207 int omask; 2208 2209 omask = sigblock(sigmask(SIGINT)|sigmask(SIGHUP)); 2210 pid = fork(); 2211 if (pid > 0) 2212 monitor_pid = pid; 2213 sigsetmask(omask); 2214 2215 switch (pid) { 2216 case -1: 2217 error("cannot fork"); 2218 break; 2219 case 0: 2220 break; 2221 default: 2222 return (0); 2223 } 2224 2225 if (chdir("/") == -1) 2226 error("chdir(\"/\")"); 2227 2228 setproctitle("%s [priv]", ifi->name); 2229 2230 dup2(nullfd, STDIN_FILENO); 2231 dup2(nullfd, STDOUT_FILENO); 2232 dup2(nullfd, STDERR_FILENO); 2233 close(nullfd); 2234 close(fd2); 2235 2236 for (;;) { 2237 pfd[0].fd = fd; 2238 pfd[0].events = POLLIN; 2239 if ((nfds = poll(pfd, 1, INFTIM)) == -1) 2240 if (errno != EINTR) 2241 error("poll error"); 2242 2243 /* 2244 * Handle temporary errors, but bail if they persist. 2245 */ 2246 if (nfds == 0 || !(pfd[0].revents & POLLIN)) { 2247 if (pfail > POLL_FAILURES) 2248 error("poll failed > %d times", POLL_FAILURES); 2249 sleep(pfail * POLL_FAILURE_WAIT); 2250 pfail++; 2251 continue; 2252 } 2253 2254 dispatch_imsg(fd); 2255 } 2256 } 2257 2258 void 2259 get_ifname(char *ifname, char *arg) 2260 { 2261 struct ifgroupreq ifgr; 2262 struct ifg_req *ifg; 2263 int s, len; 2264 2265 if (!strcmp(arg, "egress")) { 2266 s = socket(AF_INET, SOCK_DGRAM, 0); 2267 if (s == -1) 2268 error("socket error"); 2269 bzero(&ifgr, sizeof(ifgr)); 2270 strlcpy(ifgr.ifgr_name, "egress", sizeof(ifgr.ifgr_name)); 2271 if (ioctl(s, SIOCGIFGMEMB, (caddr_t)&ifgr) == -1) { 2272 if (errno == ENOENT) 2273 error("no interface in group egress found"); 2274 error("ioctl SIOCGIFGMEMB: %m"); 2275 } 2276 len = ifgr.ifgr_len; 2277 if ((ifgr.ifgr_groups = calloc(1, len)) == NULL) 2278 error("get_ifname"); 2279 if (ioctl(s, SIOCGIFGMEMB, (caddr_t)&ifgr) == -1) 2280 error("ioctl SIOCGIFGMEMB: %m"); 2281 2282 arg = NULL; 2283 for (ifg = ifgr.ifgr_groups; 2284 ifg && len >= sizeof(struct ifg_req); ifg++) { 2285 len -= sizeof(struct ifg_req); 2286 if (arg) 2287 error("too many interfaces in group egress"); 2288 arg = ifg->ifgrq_member; 2289 } 2290 2291 if (strlcpy(ifi->name, arg, IFNAMSIZ) >= IFNAMSIZ) 2292 error("Interface name too long: %m"); 2293 2294 free(ifgr.ifgr_groups); 2295 close(s); 2296 } else if (strlcpy(ifi->name, arg, IFNAMSIZ) >= IFNAMSIZ) 2297 error("Interface name too long"); 2298 } 2299 2300 static 2301 void 2302 sig_handle(int signo) 2303 { 2304 if (monitor_pid > 0) 2305 kill(monitor_pid, signo); 2306 fprintf(stderr, "killed by signal\n"); 2307 exit(1); 2308 } 2309 2310 static 2311 int 2312 killclient(int fd) 2313 { 2314 int noclient = 1; 2315 2316 /* 2317 * Kill previously running dhclient 2318 */ 2319 if (flock(fd, LOCK_EX|LOCK_NB) < 0) { 2320 char buf[256]; 2321 ssize_t n; 2322 pid_t pid; 2323 2324 lseek(fd, 0L, SEEK_SET); 2325 n = read(fd, buf, sizeof(buf)); 2326 if (n > 0) { 2327 buf[n-1] = 0; 2328 pid = strtol(buf, NULL, 10); 2329 if ((int)pid > 0) { 2330 noclient = 0; 2331 kill(pid, SIGINT); 2332 } 2333 } 2334 if (flock(fd, LOCK_EX|LOCK_NB) < 0) 2335 usleep(20000); 2336 while (flock(fd, LOCK_EX|LOCK_NB) < 0) 2337 sleep(1); 2338 } 2339 return noclient; 2340 } 2341