1 /* 2 * Copyright 2004 Henning Brauer <henning@openbsd.org> 3 * Copyright (c) 1995, 1996, 1997, 1998, 1999 4 * The Internet Software Consortium. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of The Internet Software Consortium nor the names 16 * of its contributors may be used to endorse or promote products derived 17 * from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND 20 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 21 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 22 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 23 * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR 24 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 25 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 26 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 27 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 28 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 30 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * This software has been written for the Internet Software Consortium 34 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie 35 * Enterprises. To learn more about the Internet Software Consortium, 36 * see ``http://www.vix.com/isc''. To learn more about Vixie 37 * Enterprises, see ``http://www.vix.com''. 38 * 39 * This client was substantially modified and enhanced by Elliot Poger 40 * for use on Linux while he was working on the MosquitoNet project at 41 * Stanford. 42 * 43 * The current version owes much to Elliot's Linux enhancements, but 44 * was substantially reorganized and partially rewritten by Ted Lemon 45 * so as to use the same networking framework that the Internet Software 46 * Consortium DHCP server uses. Much system-specific configuration code 47 * was moved into a shell script so that as support for more operating 48 * systems is added, it will not be necessary to port and maintain 49 * system-specific configuration code to these operating systems - instead, 50 * the shell script can invoke the native tools to accomplish the same 51 * purpose. 52 */ 53 #include <sys/ioctl.h> 54 55 #include <ctype.h> 56 #include <poll.h> 57 #include <pwd.h> 58 #include <signal.h> 59 #include <unistd.h> 60 61 #include "dhcpd.h" 62 #include "privsep.h" 63 64 #define CLIENT_PATH "PATH=/usr/bin:/usr/sbin:/bin:/sbin" 65 #define DEFAULT_LEASE_TIME 43200 /* 12 hours... */ 66 #define TIME_MAX 2147483647 67 #define POLL_FAILURES 10 68 #define POLL_FAILURE_WAIT 1 /* Back off multiplier (seconds) */ 69 70 char *path_dhclient_conf = _PATH_DHCLIENT_CONF; 71 char *path_dhclient_db = NULL; 72 char *orig_ifname; 73 74 int log_perror = 1; 75 int privfd; 76 int nullfd = -1; 77 int no_daemon; 78 int stayalive = 0; 79 int unknown_ok = 1; 80 int routefd = -1; 81 pid_t monitor_pid; 82 83 struct iaddr iaddr_broadcast = { 4, { 255, 255, 255, 255 } }; 84 struct in_addr inaddr_any; 85 struct sockaddr_in sockaddr_broadcast; 86 87 struct interface_info *ifi; 88 struct client_state *client; 89 struct client_config *config; 90 91 int findproto(char *, int); 92 struct sockaddr *get_ifa(char *, int); 93 void usage(void); 94 int check_option(struct client_lease *l, int option); 95 int ipv4addrs(char * buf); 96 int res_hnok(const char *dn); 97 char *option_as_string(unsigned int code, unsigned char *data, int len); 98 int fork_privchld(int, int); 99 void get_ifname(char *, char *); 100 static void sig_handle(int sig); 101 static int killclient(int fd); 102 103 time_t scripttime; 104 static FILE *leaseFile; 105 106 int 107 findproto(char *cp, int n) 108 { 109 struct sockaddr *sa; 110 int i; 111 112 if (n == 0) 113 return -1; 114 for (i = 1; i; i <<= 1) { 115 if (i & n) { 116 sa = (struct sockaddr *)cp; 117 switch (i) { 118 case RTA_IFA: 119 case RTA_DST: 120 case RTA_GATEWAY: 121 case RTA_NETMASK: 122 if (sa->sa_family == AF_INET) 123 return AF_INET; 124 if (sa->sa_family == AF_INET6) 125 return AF_INET6; 126 break; 127 case RTA_IFP: 128 break; 129 } 130 RT_ADVANCE(cp, sa); 131 } 132 } 133 return (-1); 134 } 135 136 struct sockaddr * 137 get_ifa(char *cp, int n) 138 { 139 struct sockaddr *sa; 140 int i; 141 142 if (n == 0) 143 return (NULL); 144 for (i = 1; i; i <<= 1) 145 if (i & n) { 146 sa = (struct sockaddr *)cp; 147 if (i == RTA_IFA) 148 return (sa); 149 RT_ADVANCE(cp, sa); 150 } 151 152 return (NULL); 153 } 154 struct iaddr defaddr = { .len = 4 }; /* NULL is for silence warnings */ 155 156 void 157 routehandler(void) 158 { 159 int linkstat; 160 char msg[2048]; 161 struct rt_msghdr *rtm; 162 struct if_msghdr *ifm; 163 struct ifa_msghdr *ifam; 164 struct if_announcemsghdr *ifan; 165 struct client_lease *l; 166 struct sockaddr *sa; 167 struct iaddr a; 168 ssize_t n; 169 char *errmsg, buf[64]; 170 171 do { 172 n = read(routefd, &msg, sizeof(msg)); 173 } while (n == -1 && errno == EINTR); 174 175 rtm = (struct rt_msghdr *)msg; 176 if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen || 177 rtm->rtm_version != RTM_VERSION) 178 return; 179 180 switch (rtm->rtm_type) { 181 case RTM_NEWADDR: 182 ifam = (struct ifa_msghdr *)rtm; 183 if (ifam->ifam_index != ifi->index) 184 break; 185 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET) 186 break; 187 sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs); 188 if (sa == NULL) { 189 errmsg = "sa == NULL"; 190 goto die; 191 } 192 193 if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf)) 194 error("king bula sez: len mismatch"); 195 memcpy(a.iabuf, &((struct sockaddr_in *)sa)->sin_addr, a.len); 196 if (addr_eq(a, defaddr)) 197 break; 198 199 /* state_panic() can try unexpired existing leases */ 200 if (client->active && addr_eq(a, client->active->address)) 201 break; 202 for (l = client->leases; l != NULL; l = l->next) 203 if (addr_eq(a, l->address)) 204 break; 205 206 if (l != NULL) 207 /* new addr is the one we set */ 208 break; 209 snprintf(buf, sizeof(buf), "%s: %s", 210 "new address not one we set", piaddr(a)); 211 errmsg = buf; 212 goto die; 213 case RTM_DELADDR: 214 ifam = (struct ifa_msghdr *)rtm; 215 if (ifam->ifam_index != ifi->index) 216 break; 217 if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET) 218 break; 219 /* XXX check addrs like RTM_NEWADDR instead of this? */ 220 if (scripttime == 0 || time(NULL) < scripttime + 10) 221 break; 222 errmsg = "interface address deleted"; 223 goto die; 224 case RTM_IFINFO: 225 ifm = (struct if_msghdr *)rtm; 226 if (ifm->ifm_index != ifi->index) 227 break; 228 if ((rtm->rtm_flags & RTF_UP) == 0) { 229 errmsg = "interface down"; 230 goto die; 231 } 232 233 linkstat = 234 LINK_STATE_IS_UP(ifm->ifm_data.ifi_link_state) ? 1 : 0; 235 if (linkstat != ifi->linkstat) { 236 #ifdef DEBUG 237 debug("link state %s -> %s", 238 ifi->linkstat ? "up" : "down", 239 linkstat ? "up" : "down"); 240 #endif 241 ifi->linkstat = interface_status(ifi->name); 242 if (ifi->linkstat) { 243 client->state = S_REBOOTING; 244 state_reboot(); 245 } 246 } 247 break; 248 case RTM_IFANNOUNCE: 249 ifan = (struct if_announcemsghdr *)rtm; 250 if (ifan->ifan_what == IFAN_DEPARTURE && 251 ifan->ifan_index == ifi->index) { 252 errmsg = "interface departure"; 253 goto die; 254 } 255 break; 256 default: 257 break; 258 } 259 return; 260 261 die: 262 script_init("FAIL"); 263 script_go(); 264 error("routehandler: %s", errmsg); 265 } 266 267 int 268 main(int argc, char *argv[]) 269 { 270 int ch, fd; 271 int pipe_fd[2]; 272 int quiet = 0; 273 int dokillclient = 0; 274 int i; 275 struct passwd *pw; 276 277 /* Initially, log errors to stderr as well as to syslogd. */ 278 openlog(getprogname(), LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY); 279 setlogmask(LOG_UPTO(LOG_INFO)); 280 281 signal(SIGINT, sig_handle); 282 signal(SIGHUP, sig_handle); 283 284 while ((ch = getopt(argc, argv, "c:dl:quwx")) != -1) { 285 switch (ch) { 286 case 'c': 287 path_dhclient_conf = optarg; 288 break; 289 case 'd': 290 no_daemon = 1; 291 break; 292 case 'l': 293 path_dhclient_db = optarg; 294 break; 295 case 'q': 296 quiet = 1; 297 break; 298 case 'u': 299 unknown_ok = 0; 300 break; 301 case 'w': 302 stayalive = 1; 303 break; 304 case 'x': 305 dokillclient = 1; 306 break; 307 default: 308 usage(); 309 } 310 } 311 312 argc -= optind; 313 argv += optind; 314 315 if (argc != 1) 316 usage(); 317 orig_ifname = argv[0]; 318 319 if (dokillclient) { 320 char buf[256]; 321 322 snprintf(buf, sizeof(buf), 323 "/var/run/dhclient.%s.pid", orig_ifname); 324 fd = open(buf, O_RDWR, 0644); 325 if (fd < 0 || killclient(fd)) { 326 fprintf(stderr, 327 "no dhclient running on %s\n", 328 orig_ifname); 329 } else { 330 fprintf(stderr, 331 "stopping dhclient on %s\n", 332 orig_ifname); 333 } 334 if (fd >= 0) 335 close(fd); 336 exit(1); 337 } 338 339 if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1) 340 error("cannot open %s: %m", _PATH_DEVNULL); 341 342 /* 343 * If asked to stay alive forever get our daemon going right now 344 * Then set up to fork/monitor and refork on exit. 345 * 346 * When I say 'forever' I really mean it. If there are configuration 347 * problems or missing interfaces or whatever, dhclient will wait 348 * 10 seconds and try again. 349 */ 350 if (stayalive) { 351 pid_t pid; 352 pid_t rpid; 353 int omask; 354 355 go_daemon(); 356 357 for (;;) { 358 omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP)); 359 pid = fork(); 360 if (pid > 0) 361 monitor_pid = pid; 362 sigsetmask(omask); 363 364 if (pid == 0) /* child falls out of loop */ 365 break; 366 while (pid > 0) { 367 rpid = waitpid(pid, NULL, 0); 368 if (rpid == pid) 369 break; 370 if (rpid != EINTR) 371 break; 372 } 373 sleep(10); 374 } 375 } 376 377 ifi = calloc(1, sizeof(*ifi)); 378 if (ifi == NULL) 379 error("ifi calloc"); 380 client = calloc(1, sizeof(*client)); 381 if (client == NULL) 382 error("client calloc"); 383 config = calloc(1, sizeof(*config)); 384 if (config == NULL) 385 error("config calloc"); 386 387 get_ifname(ifi->name, argv[0]); 388 389 if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s", 390 _PATH_DHCLIENT_DB, ifi->name) == -1) 391 error("asprintf"); 392 393 if (quiet) 394 log_perror = 0; 395 396 tzset(); 397 398 memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast)); 399 sockaddr_broadcast.sin_family = AF_INET; 400 sockaddr_broadcast.sin_port = htons(REMOTE_PORT); 401 sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST; 402 sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast); 403 inaddr_any.s_addr = INADDR_ANY; 404 405 read_client_conf(); 406 407 if (interface_status(ifi->name) == 0) { 408 interface_link_forceup(ifi->name); 409 /* Give it up to 4 seconds of silent grace to find link */ 410 i = -4; 411 } else { 412 i = 0; 413 } 414 415 while (!(ifi->linkstat = interface_status(ifi->name))) { 416 if (i == 0) 417 fprintf(stderr, "%s: no link ...", ifi->name); 418 else if (i > 0) 419 fprintf(stderr, "."); 420 fflush(stderr); 421 if (++i > config->link_timeout) { 422 fprintf(stderr, " sleeping\n"); 423 goto dispatch; 424 } 425 sleep(1); 426 } 427 if (i > 0) 428 fprintf(stderr, " got link\n"); 429 430 dispatch: 431 if ((pw = getpwnam("_dhcp")) == NULL) 432 error("no such user: _dhcp"); 433 434 if (pipe(pipe_fd) == -1) 435 error("pipe"); 436 437 go_daemon(); 438 fork_privchld(pipe_fd[0], pipe_fd[1]); 439 440 close(pipe_fd[0]); 441 privfd = pipe_fd[1]; 442 443 if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1) 444 error("can't open and lock %s: %m", path_dhclient_db); 445 read_client_leases(); 446 if ((leaseFile = fopen(path_dhclient_db, "w")) == NULL) 447 error("can't open %s: %m", path_dhclient_db); 448 rewrite_client_leases(); 449 close(fd); 450 451 if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1) 452 error("socket(PF_ROUTE, SOCK_RAW): %m"); 453 454 /* set up the interface */ 455 discover_interface(); 456 457 if (chroot(_PATH_VAREMPTY) == -1) 458 error("chroot"); 459 if (chdir("/") == -1) 460 error("chdir(\"/\")"); 461 462 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) 463 error("setresgid"); 464 if (setgroups(1, &pw->pw_gid) == -1) 465 error("setgroups"); 466 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) 467 error("setresuid"); 468 469 endpwent(); 470 471 setproctitle("%s", ifi->name); 472 473 if (ifi->linkstat) { 474 client->state = S_REBOOTING; 475 state_reboot(); 476 } 477 dispatch(); 478 479 /* not reached */ 480 return (0); 481 } 482 483 void 484 usage(void) 485 { 486 fprintf(stderr, "usage: %s [-dqu] [-c file] [-l file] interface\n", 487 getprogname()); 488 exit(1); 489 } 490 491 /* 492 * Individual States: 493 * 494 * Each routine is called from the dhclient_state_machine() in one of 495 * these conditions: 496 * -> entering INIT state 497 * -> recvpacket_flag == 0: timeout in this state 498 * -> otherwise: received a packet in this state 499 * 500 * Return conditions as handled by dhclient_state_machine(): 501 * Returns 1, sendpacket_flag = 1: send packet, reset timer. 502 * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone). 503 * Returns 0: finish the nap which was interrupted for no good reason. 504 * 505 * Several per-interface variables are used to keep track of the process: 506 * active_lease: the lease that is being used on the interface 507 * (null pointer if not configured yet). 508 * offered_leases: leases corresponding to DHCPOFFER messages that have 509 * been sent to us by DHCP servers. 510 * acked_leases: leases corresponding to DHCPACK messages that have been 511 * sent to us by DHCP servers. 512 * sendpacket: DHCP packet we're trying to send. 513 * destination: IP address to send sendpacket to 514 * In addition, there are several relevant per-lease variables. 515 * T1_expiry, T2_expiry, lease_expiry: lease milestones 516 * In the active lease, these control the process of renewing the lease; 517 * In leases on the acked_leases list, this simply determines when we 518 * can no longer legitimately use the lease. 519 */ 520 void 521 state_reboot(void) 522 { 523 /* Cancel all timeouts, since a link state change gets us here 524 and can happen anytime. */ 525 cancel_timeout(); 526 527 /* If we don't remember an active lease, go straight to INIT. */ 528 if (!client->active || client->active->is_bootp) { 529 client->state = S_INIT; 530 state_init(); 531 return; 532 } 533 534 /* make_request doesn't initialize xid because it normally comes 535 from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER, 536 so pick an xid now. */ 537 client->xid = arc4random(); 538 539 /* Make a DHCPREQUEST packet, and set appropriate per-interface 540 flags. */ 541 make_request(client->active); 542 client->destination = iaddr_broadcast; 543 client->first_sending = time(NULL); 544 client->interval = 0; 545 546 send_request(); 547 } 548 549 /* 550 * Called when a lease has completely expired and we've 551 * been unable to renew it. 552 */ 553 void 554 state_init(void) 555 { 556 /* Make a DHCPDISCOVER packet, and set appropriate per-interface 557 flags. */ 558 make_discover(client->active); 559 client->xid = client->packet.xid; 560 client->destination = iaddr_broadcast; 561 client->state = S_SELECTING; 562 client->first_sending = time(NULL); 563 client->interval = 0; 564 565 send_discover(); 566 } 567 568 /* 569 * state_selecting is called when one or more DHCPOFFER packets 570 * have been received and a configurable period of time has passed. 571 */ 572 void 573 state_selecting(void) 574 { 575 struct client_lease *lp, *next, *picked; 576 time_t cur_time; 577 578 /* Cancel state_selecting and send_discover timeouts, since either 579 one could have got us here. */ 580 cancel_timeout(); 581 582 /* We have received one or more DHCPOFFER packets. Currently, 583 the only criterion by which we judge leases is whether or 584 not we get a response when we arp for them. */ 585 picked = NULL; 586 for (lp = client->offered_leases; lp; lp = next) { 587 next = lp->next; 588 589 if (!picked) { 590 picked = lp; 591 } else { 592 make_decline(lp); 593 send_decline(); 594 free_client_lease(lp); 595 } 596 } 597 client->offered_leases = NULL; 598 599 /* If we just tossed all the leases we were offered, go back 600 to square one. */ 601 if (!picked) { 602 client->state = S_INIT; 603 state_init(); 604 return; 605 } 606 picked->next = NULL; 607 608 time(&cur_time); 609 610 /* If it was a BOOTREPLY, we can just take the address right now. */ 611 if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) { 612 client->new = picked; 613 614 /* Make up some lease expiry times 615 XXX these should be configurable. */ 616 client->new->expiry = cur_time + 12000; 617 client->new->renewal += cur_time + 8000; 618 client->new->rebind += cur_time + 10000; 619 620 client->state = S_REQUESTING; 621 622 /* Bind to the address we received. */ 623 bind_lease(); 624 return; 625 } 626 627 /* Go to the REQUESTING state. */ 628 client->destination = iaddr_broadcast; 629 client->state = S_REQUESTING; 630 client->first_sending = cur_time; 631 client->interval = 0; 632 633 /* Make a DHCPREQUEST packet from the lease we picked. */ 634 make_request(picked); 635 client->xid = client->packet.xid; 636 637 /* Toss the lease we picked - we'll get it back in a DHCPACK. */ 638 free_client_lease(picked); 639 640 send_request(); 641 } 642 643 void 644 dhcpack(struct iaddr client_addr, struct option_data *options) 645 { 646 struct client_lease *lease; 647 time_t cur_time; 648 649 650 if (client->state != S_REBOOTING && 651 client->state != S_REQUESTING && 652 client->state != S_RENEWING && 653 client->state != S_REBINDING) 654 return; 655 656 657 lease = packet_to_lease(options); 658 if (!lease) { 659 note("packet_to_lease failed."); 660 return; 661 } 662 663 client->new = lease; 664 665 /* Stop resending DHCPREQUEST. */ 666 cancel_timeout(); 667 668 /* Figure out the lease time. */ 669 if (client->new->options[DHO_DHCP_LEASE_TIME].data) 670 client->new->expiry = 671 getULong(client->new->options[DHO_DHCP_LEASE_TIME].data); 672 else 673 client->new->expiry = DEFAULT_LEASE_TIME; 674 /* A number that looks negative here is really just very large, 675 because the lease expiry offset is unsigned. */ 676 if (client->new->expiry < 0) 677 client->new->expiry = TIME_MAX; 678 /* XXX should be fixed by resetting the client state */ 679 if (client->new->expiry < 60) 680 client->new->expiry = 60; 681 682 /* Take the server-provided renewal time if there is one; 683 otherwise figure it out according to the spec. */ 684 if (client->new->options[DHO_DHCP_RENEWAL_TIME].len) 685 client->new->renewal = 686 getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data); 687 else 688 client->new->renewal = client->new->expiry / 2; 689 690 /* Same deal with the rebind time. */ 691 if (client->new->options[DHO_DHCP_REBINDING_TIME].len) 692 client->new->rebind = 693 getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data); 694 else 695 client->new->rebind = client->new->renewal + 696 client->new->renewal / 2 + client->new->renewal / 4; 697 698 time(&cur_time); 699 700 client->new->expiry += cur_time; 701 /* Lease lengths can never be negative. */ 702 if (client->new->expiry < cur_time) 703 client->new->expiry = TIME_MAX; 704 client->new->renewal += cur_time; 705 if (client->new->renewal < cur_time) 706 client->new->renewal = TIME_MAX; 707 client->new->rebind += cur_time; 708 if (client->new->rebind < cur_time) 709 client->new->rebind = TIME_MAX; 710 711 bind_lease(); 712 } 713 714 void 715 bind_lease(void) 716 { 717 /* Run the client script with the new parameters. */ 718 script_init((client->state == S_REQUESTING ? "BOUND" : 719 (client->state == S_RENEWING ? "RENEW" : 720 (client->state == S_REBOOTING ? "REBOOT" : "REBIND")))); 721 if (client->active && client->state != S_REBOOTING) 722 script_write_params("old_", client->active); 723 script_write_params("new_", client->new); 724 script_go(); 725 726 /* Replace the old active lease with the new one. */ 727 if (client->active) 728 free_client_lease(client->active); 729 client->active = client->new; 730 client->new = NULL; 731 732 /* Write out new leases file. */ 733 rewrite_client_leases(); 734 735 /* Set timeout to start the renewal process. */ 736 set_timeout(client->active->renewal, state_bound); 737 738 note("bound to %s -- renewal in %lld seconds.", 739 piaddr(client->active->address), 740 (long long)(client->active->renewal - time(NULL))); 741 client->state = S_BOUND; 742 } 743 744 /* 745 * state_bound is called when we've successfully bound to a particular 746 * lease, but the renewal time on that lease has expired. We are 747 * expected to unicast a DHCPREQUEST to the server that gave us our 748 * original lease. 749 */ 750 void 751 state_bound(void) 752 { 753 /* T1 has expired. */ 754 make_request(client->active); 755 client->xid = client->packet.xid; 756 757 if (client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) { 758 memcpy(client->destination.iabuf, 759 client->active->options[DHO_DHCP_SERVER_IDENTIFIER].data, 760 4); 761 client->destination.len = 4; 762 } else 763 client->destination = iaddr_broadcast; 764 765 client->first_sending = time(NULL); 766 client->interval = 0; 767 client->state = S_RENEWING; 768 769 send_request(); 770 } 771 772 void 773 dhcpoffer(struct iaddr client_addr, struct option_data *options) 774 { 775 struct client_lease *lease, *lp; 776 int i; 777 time_t stop_selecting; 778 char *name = options[DHO_DHCP_MESSAGE_TYPE].len ? "DHCPOFFER" : 779 "BOOTREPLY"; 780 781 782 if (client->state != S_SELECTING) 783 return; 784 785 786 /* If this lease doesn't supply the minimum required parameters, 787 blow it off. */ 788 for (i = 0; config->required_options[i]; i++) { 789 if (!options[config->required_options[i]].len) { 790 note("%s isn't satisfactory.", name); 791 return; 792 } 793 } 794 795 /* If we've already seen this lease, don't record it again. */ 796 for (lease = client->offered_leases; 797 lease; lease = lease->next) { 798 if (lease->address.len == sizeof(client->packet.yiaddr) && 799 !memcmp(lease->address.iabuf, 800 &client->packet.yiaddr, lease->address.len)) { 801 #ifdef DEBUG 802 debug("%s already seen.", name); 803 #endif 804 return; 805 } 806 } 807 808 lease = packet_to_lease(options); 809 if (!lease) { 810 note("packet_to_lease failed."); 811 return; 812 } 813 814 /* 815 * Reject offers whose subnet is already configured on another 816 * interface. 817 */ 818 if (subnet_exists(lease)) 819 return; 820 821 /* If this lease was acquired through a BOOTREPLY, record that 822 fact. */ 823 if (!options[DHO_DHCP_MESSAGE_TYPE].len) 824 lease->is_bootp = 1; 825 826 /* Figure out when we're supposed to stop selecting. */ 827 stop_selecting = client->first_sending + config->select_interval; 828 829 /* If this is the lease we asked for, put it at the head of the 830 list, and don't mess with the arp request timeout. */ 831 if (addr_eq(lease->address, client->requested_address)) { 832 lease->next = client->offered_leases; 833 client->offered_leases = lease; 834 } else { 835 /* Put the lease at the end of the list. */ 836 lease->next = NULL; 837 if (!client->offered_leases) 838 client->offered_leases = lease; 839 else { 840 for (lp = client->offered_leases; lp->next; 841 lp = lp->next) 842 ; /* nothing */ 843 lp->next = lease; 844 } 845 } 846 847 /* If the selecting interval has expired, go immediately to 848 state_selecting(). Otherwise, time out into 849 state_selecting at the select interval. */ 850 if (stop_selecting <= time(NULL)) 851 state_selecting(); 852 else { 853 set_timeout(stop_selecting, state_selecting); 854 } 855 } 856 857 /* 858 * Allocate a client_lease structure and initialize it from the 859 * parameters in the specified packet. 860 */ 861 struct client_lease * 862 packet_to_lease(struct option_data *options) 863 { 864 struct client_lease *lease; 865 int i; 866 867 lease = malloc(sizeof(struct client_lease)); 868 869 if (!lease) { 870 warning("dhcpoffer: no memory to record lease."); 871 return (NULL); 872 } 873 874 memset(lease, 0, sizeof(*lease)); 875 876 /* Copy the lease options. */ 877 for (i = 0; i < 256; i++) { 878 if (options[i].len) { 879 lease->options[i] = options[i]; 880 options[i].data = NULL; 881 options[i].len = 0; 882 if (!check_option(lease, i)) { 883 warning("Invalid lease option - ignoring offer"); 884 free_client_lease(lease); 885 return (NULL); 886 } 887 } 888 } 889 890 lease->address.len = sizeof(client->packet.yiaddr); 891 memcpy(lease->address.iabuf, &client->packet.yiaddr, 892 lease->address.len); 893 894 /* If the server name was filled out, copy it. */ 895 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len || 896 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) && 897 client->packet.sname[0]) { 898 lease->server_name = malloc(DHCP_SNAME_LEN + 1); 899 if (!lease->server_name) { 900 warning("dhcpoffer: no memory for server name."); 901 free_client_lease(lease); 902 return (NULL); 903 } 904 memcpy(lease->server_name, client->packet.sname, 905 DHCP_SNAME_LEN); 906 lease->server_name[DHCP_SNAME_LEN] = '\0'; 907 if (!res_hnok(lease->server_name)) { 908 warning("Bogus server name %s", lease->server_name); 909 free(lease->server_name); 910 lease->server_name = NULL; 911 } 912 } 913 914 /* Ditto for the filename. */ 915 if ((!lease->options[DHO_DHCP_OPTION_OVERLOAD].len || 916 !(lease->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) && 917 client->packet.file[0]) { 918 /* Don't count on the NUL terminator. */ 919 lease->filename = malloc(DHCP_FILE_LEN + 1); 920 if (!lease->filename) { 921 warning("dhcpoffer: no memory for filename."); 922 free_client_lease(lease); 923 return (NULL); 924 } 925 memcpy(lease->filename, client->packet.file, DHCP_FILE_LEN); 926 lease->filename[DHCP_FILE_LEN] = '\0'; 927 } 928 return lease; 929 } 930 931 void 932 dhcpnak(struct iaddr client_addr, struct option_data *options) 933 { 934 935 if (client->state != S_REBOOTING && 936 client->state != S_REQUESTING && 937 client->state != S_RENEWING && 938 client->state != S_REBINDING) 939 return; 940 941 942 if (!client->active) { 943 note("DHCPNAK with no active lease."); 944 return; 945 } 946 947 free_client_lease(client->active); 948 client->active = NULL; 949 950 /* Stop sending DHCPREQUEST packets... */ 951 cancel_timeout(); 952 953 client->state = S_INIT; 954 state_init(); 955 } 956 957 /* 958 * Send out a DHCPDISCOVER packet, and set a timeout to send out another 959 * one after the right interval has expired. If we don't get an offer by 960 * the time we reach the panic interval, call the panic function. 961 */ 962 void 963 send_discover(void) 964 { 965 time_t cur_time; 966 int interval, increase = 1; 967 968 time(&cur_time); 969 970 /* Figure out how long it's been since we started transmitting. */ 971 interval = cur_time - client->first_sending; 972 973 /* If we're past the panic timeout, call the script and tell it 974 we haven't found anything for this interface yet. */ 975 if (interval > config->timeout) { 976 state_panic(); 977 return; 978 } 979 980 /* 981 * If we're supposed to increase the interval, do so. If it's 982 * currently zero (i.e., we haven't sent any packets yet), set 983 * it to initial_interval; otherwise, add to it a random 984 * number between zero and two times itself. On average, this 985 * means that it will double with every transmission. 986 */ 987 if (increase) { 988 if (!client->interval) 989 client->interval = config->initial_interval; 990 else { 991 client->interval += (arc4random() >> 2) % 992 (2 * client->interval); 993 } 994 995 /* Don't backoff past cutoff. */ 996 if (client->interval > config->backoff_cutoff) 997 client->interval = ((config->backoff_cutoff / 2) 998 + ((arc4random() >> 2) % 999 config->backoff_cutoff)); 1000 } else if (!client->interval) 1001 client->interval = config->initial_interval; 1002 1003 /* If the backoff would take us to the panic timeout, just use that 1004 as the interval. */ 1005 if (cur_time + client->interval > 1006 client->first_sending + config->timeout) 1007 client->interval = (client->first_sending + 1008 config->timeout) - cur_time + 1; 1009 1010 /* Record the number of seconds since we started sending. */ 1011 if (interval < 65536) 1012 client->packet.secs = htons(interval); 1013 else 1014 client->packet.secs = htons(65535); 1015 client->secs = client->packet.secs; 1016 1017 note("DHCPDISCOVER on %s to %s port %d interval %ld", 1018 ifi->name, inet_ntoa(sockaddr_broadcast.sin_addr), 1019 ntohs(sockaddr_broadcast.sin_port), client->interval); 1020 1021 send_packet(inaddr_any, &sockaddr_broadcast, NULL); 1022 1023 set_timeout_interval(client->interval, send_discover); 1024 } 1025 1026 /* 1027 * state_panic gets called if we haven't received any offers in a preset 1028 * amount of time. When this happens, we try to use existing leases 1029 * that haven't yet expired, and failing that, we call the client script 1030 * and hope it can do something. 1031 */ 1032 void 1033 state_panic(void) 1034 { 1035 struct client_lease *loop = client->active; 1036 struct client_lease *lp; 1037 time_t cur_time; 1038 1039 note("No DHCPOFFERS received."); 1040 1041 /* We may not have an active lease, but we may have some 1042 predefined leases that we can try. */ 1043 if (!client->active && client->leases) 1044 goto activate_next; 1045 1046 /* Run through the list of leases and see if one can be used. */ 1047 time(&cur_time); 1048 while (client->active) { 1049 if (client->active->expiry > cur_time) { 1050 note("Trying recorded lease %s", 1051 piaddr(client->active->address)); 1052 /* Run the client script with the existing 1053 parameters. */ 1054 script_init("TIMEOUT"); 1055 script_write_params("new_", client->active); 1056 1057 /* If the old lease is still good and doesn't 1058 yet need renewal, go into BOUND state and 1059 timeout at the renewal time. */ 1060 if (!script_go()) { 1061 if (cur_time < client->active->renewal) { 1062 client->state = S_BOUND; 1063 note("bound: renewal in %lld seconds.", 1064 (long long)(client->active->renewal 1065 - cur_time)); 1066 set_timeout(client->active->renewal, 1067 state_bound); 1068 } else { 1069 client->state = S_BOUND; 1070 note("bound: immediate renewal."); 1071 state_bound(); 1072 } 1073 return; 1074 } 1075 } 1076 1077 /* If there are no other leases, give up. */ 1078 if (!client->leases) { 1079 client->leases = client->active; 1080 client->active = NULL; 1081 break; 1082 } 1083 1084 activate_next: 1085 /* Otherwise, put the active lease at the end of the 1086 lease list, and try another lease.. */ 1087 for (lp = client->leases; lp->next; lp = lp->next) 1088 ; 1089 lp->next = client->active; 1090 if (lp->next) 1091 lp->next->next = NULL; 1092 client->active = client->leases; 1093 client->leases = client->leases->next; 1094 1095 /* If we already tried this lease, we've exhausted the 1096 set of leases, so we might as well give up for 1097 now. */ 1098 if (client->active == loop) 1099 break; 1100 else if (!loop) 1101 loop = client->active; 1102 } 1103 1104 /* No leases were available, or what was available didn't work, so 1105 tell the shell script that we failed to allocate an address, 1106 and try again later. */ 1107 note("No working leases in persistent database - sleeping."); 1108 script_init("FAIL"); 1109 script_go(); 1110 client->state = S_INIT; 1111 set_timeout_interval(config->retry_interval, state_init); 1112 } 1113 1114 void 1115 send_request(void) 1116 { 1117 struct sockaddr_in destination; 1118 struct in_addr from; 1119 time_t cur_time; 1120 int interval; 1121 1122 time(&cur_time); 1123 1124 /* Figure out how long it's been since we started transmitting. */ 1125 interval = (int)(cur_time - client->first_sending); 1126 1127 /* If we're in the INIT-REBOOT or REQUESTING state and we're 1128 past the reboot timeout, go to INIT and see if we can 1129 DISCOVER an address... */ 1130 /* XXX In the INIT-REBOOT state, if we don't get an ACK, it 1131 means either that we're on a network with no DHCP server, 1132 or that our server is down. In the latter case, assuming 1133 that there is a backup DHCP server, DHCPDISCOVER will get 1134 us a new address, but we could also have successfully 1135 reused our old address. In the former case, we're hosed 1136 anyway. This is not a win-prone situation. */ 1137 if ((client->state == S_REBOOTING || 1138 client->state == S_REQUESTING) && 1139 interval > config->reboot_timeout) { 1140 client->state = S_INIT; 1141 cancel_timeout(); 1142 state_init(); 1143 return; 1144 } 1145 1146 /* If the lease has expired, relinquish the address and go back 1147 to the INIT state. */ 1148 if (client->state != S_REQUESTING && 1149 cur_time > client->active->expiry) { 1150 /* Run the client script with the new parameters. */ 1151 script_init("EXPIRE"); 1152 script_write_params("old_", client->active); 1153 script_go(); 1154 1155 client->state = S_INIT; 1156 state_init(); 1157 return; 1158 } 1159 1160 /* Do the exponential backoff... */ 1161 if (!client->interval) 1162 client->interval = config->initial_interval; 1163 else 1164 client->interval += ((arc4random() >> 2) % 1165 (2 * client->interval)); 1166 1167 /* Don't backoff past cutoff. */ 1168 if (client->interval > config->backoff_cutoff) 1169 client->interval = ((config->backoff_cutoff / 2) + 1170 ((arc4random() >> 2) % client->interval)); 1171 1172 /* If the backoff would take us to the expiry time, just set the 1173 timeout to the expiry time. */ 1174 if (client->state != S_REQUESTING && cur_time + client->interval > 1175 client->active->expiry) 1176 client->interval = client->active->expiry - cur_time + 1; 1177 1178 /* If the lease T2 time has elapsed, or if we're not yet bound, 1179 broadcast the DHCPREQUEST rather than unicasting. */ 1180 memset(&destination, 0, sizeof(destination)); 1181 if (client->state == S_REQUESTING || 1182 client->state == S_REBOOTING || 1183 cur_time > client->active->rebind) 1184 destination.sin_addr.s_addr = INADDR_BROADCAST; 1185 else 1186 memcpy(&destination.sin_addr.s_addr, client->destination.iabuf, 1187 sizeof(destination.sin_addr.s_addr)); 1188 destination.sin_port = htons(REMOTE_PORT); 1189 destination.sin_family = AF_INET; 1190 destination.sin_len = sizeof(destination); 1191 1192 if (client->state != S_REQUESTING) 1193 memcpy(&from, client->active->address.iabuf, sizeof(from)); 1194 else 1195 from.s_addr = INADDR_ANY; 1196 1197 /* Record the number of seconds since we started sending. */ 1198 if (client->state == S_REQUESTING) 1199 client->packet.secs = client->secs; 1200 else { 1201 if (interval < 65536) 1202 client->packet.secs = htons(interval); 1203 else 1204 client->packet.secs = htons(65535); 1205 } 1206 1207 note("DHCPREQUEST on %s to %s port %d", ifi->name, 1208 inet_ntoa(destination.sin_addr), ntohs(destination.sin_port)); 1209 1210 send_packet(from, &destination, NULL); 1211 1212 set_timeout_interval(client->interval, send_request); 1213 } 1214 1215 void 1216 send_decline(void) 1217 { 1218 note("DHCPDECLINE on %s to %s port %d", ifi->name, 1219 inet_ntoa(sockaddr_broadcast.sin_addr), 1220 ntohs(sockaddr_broadcast.sin_port)); 1221 1222 send_packet(inaddr_any, &sockaddr_broadcast, NULL); 1223 } 1224 1225 void 1226 make_discover(struct client_lease *lease) 1227 { 1228 unsigned char discover = DHCPDISCOVER; 1229 struct option_data options[256]; 1230 int i; 1231 1232 memset(options, 0, sizeof(options)); 1233 memset(&client->packet, 0, sizeof(client->packet)); 1234 1235 /* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */ 1236 i = DHO_DHCP_MESSAGE_TYPE; 1237 options[i].data = &discover; 1238 options[i].len = sizeof(discover); 1239 1240 /* Request the options we want */ 1241 i = DHO_DHCP_PARAMETER_REQUEST_LIST; 1242 options[i].data = config->requested_options; 1243 options[i].len = config->requested_option_count; 1244 1245 /* If we had an address, try to get it again. */ 1246 if (lease) { 1247 client->requested_address = lease->address; 1248 i = DHO_DHCP_REQUESTED_ADDRESS; 1249 options[i].data = lease->address.iabuf; 1250 options[i].len = lease->address.len; 1251 } else 1252 client->requested_address.len = 0; 1253 1254 /* Send any options requested in the config file. */ 1255 for (i = 0; i < 256; i++) 1256 if (!options[i].data && 1257 config->send_options[i].data) { 1258 options[i].data = config->send_options[i].data; 1259 options[i].len = config->send_options[i].len; 1260 } 1261 1262 /* Set up the option buffer to fit in a minimal UDP packet. */ 1263 i = cons_options(options); 1264 if (i == -1 || client->packet.options[i] != DHO_END) 1265 error("options do not fit in DHCPDISCOVER packet."); 1266 client->packet_length = DHCP_FIXED_NON_UDP+i+1; 1267 if (client->packet_length < BOOTP_MIN_LEN) 1268 client->packet_length = BOOTP_MIN_LEN; 1269 1270 client->packet.op = BOOTREQUEST; 1271 client->packet.htype = ifi->hw_address.htype; 1272 client->packet.hlen = ifi->hw_address.hlen; 1273 client->packet.hops = 0; 1274 client->packet.xid = arc4random(); 1275 client->packet.secs = 0; /* filled in by send_discover. */ 1276 client->packet.flags = 0; 1277 1278 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr)); 1279 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr)); 1280 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr)); 1281 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr)); 1282 memcpy(client->packet.chaddr, ifi->hw_address.haddr, 1283 ifi->hw_address.hlen); 1284 } 1285 1286 void 1287 make_request(struct client_lease * lease) 1288 { 1289 unsigned char request = DHCPREQUEST; 1290 struct option_data options[256]; 1291 int i; 1292 1293 memset(options, 0, sizeof(options)); 1294 memset(&client->packet, 0, sizeof(client->packet)); 1295 1296 /* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */ 1297 i = DHO_DHCP_MESSAGE_TYPE; 1298 options[i].data = &request; 1299 options[i].len = sizeof(request); 1300 1301 /* Request the options we want */ 1302 i = DHO_DHCP_PARAMETER_REQUEST_LIST; 1303 options[i].data = config->requested_options; 1304 options[i].len = config->requested_option_count; 1305 1306 /* If we are requesting an address that hasn't yet been assigned 1307 to us, use the DHCP Requested Address option. */ 1308 if (client->state == S_REQUESTING) { 1309 /* Send back the server identifier... */ 1310 i = DHO_DHCP_SERVER_IDENTIFIER; 1311 options[i].data = lease->options[i].data; 1312 options[i].len = lease->options[i].len; 1313 } 1314 if (client->state == S_REQUESTING || 1315 client->state == S_REBOOTING) { 1316 client->requested_address = lease->address; 1317 i = DHO_DHCP_REQUESTED_ADDRESS; 1318 options[i].data = lease->address.iabuf; 1319 options[i].len = lease->address.len; 1320 } else 1321 client->requested_address.len = 0; 1322 1323 /* Send any options requested in the config file. */ 1324 for (i = 0; i < 256; i++) 1325 if (!options[i].data && config->send_options[i].data) { 1326 options[i].data = config->send_options[i].data; 1327 options[i].len = config->send_options[i].len; 1328 } 1329 1330 /* Set up the option buffer to fit in a minimal UDP packet. */ 1331 i = cons_options(options); 1332 if (i == -1 || client->packet.options[i] != DHO_END) 1333 error("options do not fit in DHCPREQUEST packet."); 1334 client->packet_length = DHCP_FIXED_NON_UDP+i+1; 1335 if (client->packet_length < BOOTP_MIN_LEN) 1336 client->packet_length = BOOTP_MIN_LEN; 1337 1338 client->packet.op = BOOTREQUEST; 1339 client->packet.htype = ifi->hw_address.htype; 1340 client->packet.hlen = ifi->hw_address.hlen; 1341 client->packet.hops = 0; 1342 client->packet.xid = client->xid; 1343 client->packet.secs = 0; /* Filled in by send_request. */ 1344 client->packet.flags = 0; 1345 1346 /* If we own the address we're requesting, put it in ciaddr; 1347 otherwise set ciaddr to zero. */ 1348 if (client->state == S_BOUND || 1349 client->state == S_RENEWING || 1350 client->state == S_REBINDING) { 1351 memcpy(&client->packet.ciaddr, 1352 lease->address.iabuf, lease->address.len); 1353 } else { 1354 memset(&client->packet.ciaddr, 0, 1355 sizeof(client->packet.ciaddr)); 1356 } 1357 1358 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr)); 1359 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr)); 1360 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr)); 1361 memcpy(client->packet.chaddr, ifi->hw_address.haddr, 1362 ifi->hw_address.hlen); 1363 } 1364 1365 void 1366 make_decline(struct client_lease *lease) 1367 { 1368 struct option_data options[256]; 1369 unsigned char decline = DHCPDECLINE; 1370 int i; 1371 1372 memset(options, 0, sizeof(options)); 1373 memset(&client->packet, 0, sizeof(client->packet)); 1374 1375 /* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */ 1376 i = DHO_DHCP_MESSAGE_TYPE; 1377 options[i].data = &decline; 1378 options[i].len = sizeof(decline); 1379 1380 /* Send back the server identifier... */ 1381 i = DHO_DHCP_SERVER_IDENTIFIER; 1382 options[i].data = lease->options[i].data; 1383 options[i].len = lease->options[i].len; 1384 1385 /* Send back the address we're declining. */ 1386 i = DHO_DHCP_REQUESTED_ADDRESS; 1387 options[i].data = lease->address.iabuf; 1388 options[i].len = lease->address.len; 1389 1390 /* Send the uid if the user supplied one. */ 1391 i = DHO_DHCP_CLIENT_IDENTIFIER; 1392 if (config->send_options[i].len) { 1393 options[i].data = config->send_options[i].data; 1394 options[i].len = config->send_options[i].len; 1395 } 1396 1397 /* Set up the option buffer to fit in a minimal UDP packet. */ 1398 i = cons_options(options); 1399 if (i == -1 || client->packet.options[i] != DHO_END) 1400 error("options do not fit in DHCPDECLINE packet."); 1401 client->packet_length = DHCP_FIXED_NON_UDP+i+1; 1402 if (client->packet_length < BOOTP_MIN_LEN) 1403 client->packet_length = BOOTP_MIN_LEN; 1404 1405 client->packet.op = BOOTREQUEST; 1406 client->packet.htype = ifi->hw_address.htype; 1407 client->packet.hlen = ifi->hw_address.hlen; 1408 client->packet.hops = 0; 1409 client->packet.xid = client->xid; 1410 client->packet.secs = 0; /* Filled in by send_request. */ 1411 client->packet.flags = 0; 1412 1413 /* ciaddr must always be zero. */ 1414 memset(&client->packet.ciaddr, 0, sizeof(client->packet.ciaddr)); 1415 memset(&client->packet.yiaddr, 0, sizeof(client->packet.yiaddr)); 1416 memset(&client->packet.siaddr, 0, sizeof(client->packet.siaddr)); 1417 memset(&client->packet.giaddr, 0, sizeof(client->packet.giaddr)); 1418 memcpy(client->packet.chaddr, ifi->hw_address.haddr, 1419 ifi->hw_address.hlen); 1420 } 1421 1422 void 1423 free_client_lease(struct client_lease *lease) 1424 { 1425 int i; 1426 1427 if (lease->server_name) 1428 free(lease->server_name); 1429 if (lease->filename) 1430 free(lease->filename); 1431 for (i = 0; i < 256; i++) { 1432 if (lease->options[i].len) 1433 free(lease->options[i].data); 1434 } 1435 free(lease); 1436 } 1437 1438 void 1439 rewrite_client_leases(void) 1440 { 1441 struct client_lease *lp; 1442 1443 if (!leaseFile) /* XXX */ 1444 error("lease file not open"); 1445 1446 fflush(leaseFile); 1447 rewind(leaseFile); 1448 1449 for (lp = client->leases; lp; lp = lp->next) { 1450 if (client->active && addr_eq(lp->address, 1451 client->active->address)) 1452 continue; 1453 write_client_lease(lp); 1454 } 1455 1456 if (client->active) 1457 write_client_lease(client->active); 1458 1459 fflush(leaseFile); 1460 ftruncate(fileno(leaseFile), ftello(leaseFile)); 1461 fsync(fileno(leaseFile)); 1462 } 1463 1464 void 1465 write_client_lease(struct client_lease *lease) 1466 { 1467 struct tm *t; 1468 int i; 1469 1470 /* If the lease came from the config file, we don't need to stash 1471 a copy in the lease database. */ 1472 if (lease->is_static) 1473 return; 1474 1475 if (!leaseFile) /* XXX */ 1476 error("lease file not open"); 1477 1478 fprintf(leaseFile, "lease {\n"); 1479 if (lease->is_bootp) 1480 fprintf(leaseFile, " bootp;\n"); 1481 fprintf(leaseFile, " interface \"%s\";\n", ifi->name); 1482 fprintf(leaseFile, " fixed-address %s;\n", piaddr(lease->address)); 1483 if (lease->filename) 1484 fprintf(leaseFile, " filename \"%s\";\n", lease->filename); 1485 if (lease->server_name) 1486 fprintf(leaseFile, " server-name \"%s\";\n", 1487 lease->server_name); 1488 for (i = 0; i < 256; i++) 1489 if (lease->options[i].len) 1490 fprintf(leaseFile, " option %s %s;\n", 1491 dhcp_options[i].name, 1492 pretty_print_option(i, &lease->options[i], 1)); 1493 1494 t = gmtime(&lease->renewal); 1495 fprintf(leaseFile, " renew %d %d/%d/%d %02d:%02d:%02d;\n", 1496 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, 1497 t->tm_hour, t->tm_min, t->tm_sec); 1498 t = gmtime(&lease->rebind); 1499 fprintf(leaseFile, " rebind %d %d/%d/%d %02d:%02d:%02d;\n", 1500 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, 1501 t->tm_hour, t->tm_min, t->tm_sec); 1502 t = gmtime(&lease->expiry); 1503 fprintf(leaseFile, " expire %d %d/%d/%d %02d:%02d:%02d;\n", 1504 t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, 1505 t->tm_hour, t->tm_min, t->tm_sec); 1506 fprintf(leaseFile, "}\n"); 1507 fflush(leaseFile); 1508 } 1509 1510 void 1511 script_init(char *reason) 1512 { 1513 size_t len; 1514 struct imsg_hdr hdr; 1515 struct buf *buf; 1516 1517 hdr.code = IMSG_SCRIPT_INIT; 1518 hdr.len = sizeof(struct imsg_hdr) + sizeof(size_t) + strlen(reason); 1519 buf = buf_open(hdr.len); 1520 1521 buf_add(buf, &hdr, sizeof(hdr)); 1522 len = strlen(reason); 1523 buf_add(buf, &len, sizeof(len)); 1524 buf_add(buf, reason, len); 1525 1526 buf_close(privfd, buf); 1527 } 1528 1529 void 1530 priv_script_init(char *reason) 1531 { 1532 client->scriptEnvsize = 100; 1533 if (client->scriptEnv == NULL) 1534 client->scriptEnv = 1535 calloc(client->scriptEnvsize, sizeof(char *)); 1536 if (client->scriptEnv == NULL) 1537 error("script_init: no memory for environment"); 1538 1539 client->scriptEnv[0] = strdup(CLIENT_PATH); 1540 if (client->scriptEnv[0] == NULL) 1541 error("script_init: no memory for environment"); 1542 1543 client->scriptEnv[1] = NULL; 1544 1545 script_set_env("", "interface", ifi->name); 1546 1547 script_set_env("", "reason", reason); 1548 } 1549 1550 void 1551 priv_script_write_params(char *prefix, struct client_lease *lease) 1552 { 1553 char buf[256]; 1554 struct option_data o; 1555 int i; 1556 1557 script_set_env(prefix, "ip_address", piaddr(lease->address)); 1558 1559 if (lease->options[DHO_SUBNET_MASK].len && 1560 (lease->options[DHO_SUBNET_MASK].len < 1561 sizeof(lease->address.iabuf))) { 1562 struct iaddr netmask, subnet, broadcast; 1563 1564 memcpy(netmask.iabuf, lease->options[DHO_SUBNET_MASK].data, 1565 lease->options[DHO_SUBNET_MASK].len); 1566 netmask.len = lease->options[DHO_SUBNET_MASK].len; 1567 1568 subnet = subnet_number(lease->address, netmask); 1569 if (subnet.len) { 1570 script_set_env(prefix, "network_number", 1571 piaddr(subnet)); 1572 if (!lease->options[DHO_BROADCAST_ADDRESS].len) { 1573 broadcast = broadcast_addr(subnet, netmask); 1574 if (broadcast.len) 1575 script_set_env(prefix, 1576 "broadcast_address", 1577 piaddr(broadcast)); 1578 } 1579 } 1580 } 1581 1582 if (lease->filename) 1583 script_set_env(prefix, "filename", lease->filename); 1584 if (lease->server_name) 1585 script_set_env(prefix, "server_name", 1586 lease->server_name); 1587 1588 for (i = 0; i < 256; i++) { 1589 if (!dhcp_option_ev_name(buf, sizeof(buf), &dhcp_options[i])) 1590 continue; 1591 1592 switch (config->default_actions[i]) { 1593 case ACTION_IGNORE: 1594 break; 1595 1596 case ACTION_DEFAULT: 1597 if (lease->options[i].len) 1598 script_set_env(prefix, buf, 1599 pretty_print_option(i, &lease->options[i], 1600 0)); 1601 else if (config->defaults[i].len) 1602 script_set_env(prefix, buf, 1603 pretty_print_option(i, &config->defaults[i], 1604 0)); 1605 break; 1606 1607 case ACTION_SUPERSEDE: 1608 if (config->defaults[i].len) 1609 script_set_env(prefix, buf, 1610 pretty_print_option(i, &config->defaults[i], 1611 0)); 1612 break; 1613 1614 case ACTION_PREPEND: 1615 o.len = config->defaults[i].len + lease->options[i].len; 1616 if (o.len > 0) { 1617 o.data = calloc(1, o.len); 1618 if (o.data == NULL) 1619 error("no space to prepend '%s' to %s", 1620 config->defaults[i].data, 1621 dhcp_options[i].name); 1622 memcpy(o.data, config->defaults[i].data, 1623 config->defaults[i].len); 1624 memcpy(o.data + config->defaults[i].len, 1625 lease->options[i].data, 1626 lease->options[i].len); 1627 script_set_env(prefix, buf, 1628 pretty_print_option(i, &o, 0)); 1629 free(o.data); 1630 } 1631 break; 1632 1633 case ACTION_APPEND: 1634 o.len = config->defaults[i].len + lease->options[i].len; 1635 if (o.len > 0) { 1636 o.data = calloc(1, o.len); 1637 if (o.data == NULL) 1638 error("no space to append '%s' to %s", 1639 config->defaults[i].data, 1640 dhcp_options[i].name); 1641 memcpy(o.data, lease->options[i].data, 1642 lease->options[i].len); 1643 memcpy(o.data + lease->options[i].len, 1644 config->defaults[i].data, 1645 config->defaults[i].len); 1646 script_set_env(prefix, buf, 1647 pretty_print_option(i, &o, 0)); 1648 free(o.data); 1649 } 1650 break; 1651 } 1652 } 1653 1654 snprintf(buf, sizeof(buf), "%d", (int)lease->expiry); 1655 script_set_env(prefix, "expiry", buf); 1656 } 1657 1658 void 1659 script_write_params(char *prefix, struct client_lease *lease) 1660 { 1661 size_t fn_len = 0, sn_len = 0, pr_len = 0; 1662 struct imsg_hdr hdr; 1663 struct buf *buf; 1664 int i; 1665 1666 if (lease->filename != NULL) 1667 fn_len = strlen(lease->filename); 1668 if (lease->server_name != NULL) 1669 sn_len = strlen(lease->server_name); 1670 if (prefix != NULL) 1671 pr_len = strlen(prefix); 1672 1673 hdr.code = IMSG_SCRIPT_WRITE_PARAMS; 1674 hdr.len = sizeof(hdr) + sizeof(struct client_lease) + 1675 sizeof(size_t) + fn_len + sizeof(size_t) + sn_len + 1676 sizeof(size_t) + pr_len; 1677 1678 for (i = 0; i < 256; i++) 1679 hdr.len += sizeof(int) + lease->options[i].len; 1680 1681 scripttime = time(NULL); 1682 1683 buf = buf_open(hdr.len); 1684 1685 buf_add(buf, &hdr, sizeof(hdr)); 1686 buf_add(buf, lease, sizeof(struct client_lease)); 1687 buf_add(buf, &fn_len, sizeof(fn_len)); 1688 buf_add(buf, lease->filename, fn_len); 1689 buf_add(buf, &sn_len, sizeof(sn_len)); 1690 buf_add(buf, lease->server_name, sn_len); 1691 buf_add(buf, &pr_len, sizeof(pr_len)); 1692 buf_add(buf, prefix, pr_len); 1693 1694 for (i = 0; i < 256; i++) { 1695 buf_add(buf, &lease->options[i].len, 1696 sizeof(lease->options[i].len)); 1697 buf_add(buf, lease->options[i].data, 1698 lease->options[i].len); 1699 } 1700 1701 buf_close(privfd, buf); 1702 } 1703 1704 int 1705 script_go(void) 1706 { 1707 struct imsg_hdr hdr; 1708 struct buf *buf; 1709 int ret; 1710 1711 scripttime = time(NULL); 1712 1713 hdr.code = IMSG_SCRIPT_GO; 1714 hdr.len = sizeof(struct imsg_hdr); 1715 1716 buf = buf_open(hdr.len); 1717 1718 buf_add(buf, &hdr, sizeof(hdr)); 1719 buf_close(privfd, buf); 1720 1721 bzero(&hdr, sizeof(hdr)); 1722 buf_read(privfd, &hdr, sizeof(hdr)); 1723 if (hdr.code != IMSG_SCRIPT_GO_RET) 1724 error("unexpected msg type %u", hdr.code); 1725 if (hdr.len != sizeof(hdr) + sizeof(int)) 1726 error("received corrupted message"); 1727 buf_read(privfd, &ret, sizeof(ret)); 1728 1729 return (ret); 1730 } 1731 1732 int 1733 priv_script_go(void) 1734 { 1735 char *scriptName, *argv[2], **envp; 1736 int pid, wpid, wstatus; 1737 1738 scripttime = time(NULL); 1739 1740 scriptName = config->script_name; 1741 envp = client->scriptEnv; 1742 1743 argv[0] = scriptName; 1744 argv[1] = NULL; 1745 1746 pid = fork(); 1747 if (pid < 0) { 1748 error("fork: %m"); 1749 wstatus = 0; 1750 } else if (pid) { 1751 do { 1752 wpid = wait(&wstatus); 1753 } while (wpid != pid && wpid > 0); 1754 if (wpid < 0) { 1755 error("wait: %m"); 1756 wstatus = 0; 1757 } 1758 } else { 1759 execve(scriptName, argv, envp); 1760 error("execve (%s, ...): %m", scriptName); 1761 } 1762 1763 script_flush_env(); 1764 1765 return (WEXITSTATUS(wstatus)); 1766 } 1767 1768 void 1769 script_set_env(const char *prefix, const char *name, const char *value) 1770 { 1771 int i, j, namelen; 1772 1773 namelen = strlen(name); 1774 1775 for (i = 0; client->scriptEnv[i]; i++) 1776 if (strncmp(client->scriptEnv[i], name, namelen) == 0 && 1777 client->scriptEnv[i][namelen] == '=') 1778 break; 1779 1780 if (client->scriptEnv[i]) 1781 /* Reuse the slot. */ 1782 free(client->scriptEnv[i]); 1783 else { 1784 /* New variable. Expand if necessary. */ 1785 if (i >= client->scriptEnvsize - 1) { 1786 char **newscriptEnv; 1787 int newscriptEnvsize = client->scriptEnvsize + 50; 1788 1789 newscriptEnv = realloc(client->scriptEnv, 1790 newscriptEnvsize); 1791 if (newscriptEnv == NULL) { 1792 free(client->scriptEnv); 1793 client->scriptEnv = NULL; 1794 client->scriptEnvsize = 0; 1795 error("script_set_env: no memory for variable"); 1796 } 1797 client->scriptEnv = newscriptEnv; 1798 client->scriptEnvsize = newscriptEnvsize; 1799 } 1800 /* need to set the NULL pointer at end of array beyond 1801 the new slot. */ 1802 client->scriptEnv[i + 1] = NULL; 1803 } 1804 /* Allocate space and format the variable in the appropriate slot. */ 1805 client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 + 1806 strlen(value) + 1); 1807 if (client->scriptEnv[i] == NULL) 1808 error("script_set_env: no memory for variable assignment"); 1809 1810 /* No `` or $() command substitution allowed in environment values! */ 1811 for (j = 0; j < strlen(value); j++) 1812 switch (value[j]) { 1813 case '`': 1814 case '$': 1815 error("illegal character (%c) in value '%s'", value[j], 1816 value); 1817 /* not reached */ 1818 } 1819 snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) + 1820 1 + strlen(value) + 1, "%s%s=%s", prefix, name, value); 1821 } 1822 1823 void 1824 script_flush_env(void) 1825 { 1826 int i; 1827 1828 for (i = 0; client->scriptEnv[i]; i++) { 1829 free(client->scriptEnv[i]); 1830 client->scriptEnv[i] = NULL; 1831 } 1832 client->scriptEnvsize = 0; 1833 } 1834 1835 int 1836 dhcp_option_ev_name(char *buf, size_t buflen, const struct option *option) 1837 { 1838 size_t i; 1839 1840 for (i = 0; option->name[i]; i++) { 1841 if (i + 1 == buflen) 1842 return 0; 1843 if (option->name[i] == '-') 1844 buf[i] = '_'; 1845 else 1846 buf[i] = option->name[i]; 1847 } 1848 1849 buf[i] = 0; 1850 return 1; 1851 } 1852 1853 void 1854 go_daemon(void) 1855 { 1856 char buf[256]; 1857 int fd; 1858 1859 /* 1860 * Only once 1861 */ 1862 if (no_daemon == 2) 1863 return; 1864 1865 /* 1866 * Setup pidfile, kill any dhclient already running for this 1867 * interface. 1868 */ 1869 snprintf(buf, sizeof(buf), "/var/run/dhclient.%s.pid", orig_ifname); 1870 fd = open(buf, O_RDWR|O_CREAT, 0644); 1871 if (fd >= 0) { 1872 if (killclient(fd)) { 1873 fprintf(stderr, 1874 "starting dhclient on %s\n", 1875 orig_ifname); 1876 } else { 1877 fprintf(stderr, 1878 "restarting dhclient on %s\n", 1879 orig_ifname); 1880 } 1881 } 1882 1883 /* 1884 * Daemonize if requested 1885 */ 1886 if (no_daemon == 0) { 1887 /* Stop logging to stderr... */ 1888 log_perror = 0; 1889 1890 if (daemon(1, 0) == -1) 1891 error("daemon"); 1892 1893 /* we are chrooted, daemon(3) fails to open /dev/null */ 1894 if (nullfd != -1) { 1895 dup2(nullfd, STDIN_FILENO); 1896 dup2(nullfd, STDOUT_FILENO); 1897 dup2(nullfd, STDERR_FILENO); 1898 close(nullfd); 1899 nullfd = -1; 1900 } 1901 } 1902 1903 /* 1904 * No further daemonizations, write out pid file and lock. 1905 */ 1906 no_daemon = 2; 1907 if (fd >= 0) { 1908 lseek(fd, 0L, SEEK_SET); 1909 ftruncate(fd, 0); 1910 snprintf(buf, sizeof(buf), "%ld\n", (long)getpid()); 1911 write(fd, buf, strlen(buf)); 1912 flock(fd, LOCK_EX); 1913 /* leave descriptor open and locked */ 1914 } 1915 } 1916 1917 int 1918 check_option(struct client_lease *l, int option) 1919 { 1920 char *opbuf; 1921 char *sbuf; 1922 1923 /* we use this, since this is what gets passed to dhclient-script */ 1924 1925 opbuf = pretty_print_option(option, &l->options[option], 0); 1926 1927 sbuf = option_as_string(option, l->options[option].data, 1928 l->options[option].len); 1929 1930 switch (option) { 1931 case DHO_SUBNET_MASK: 1932 case DHO_SWAP_SERVER: 1933 case DHO_BROADCAST_ADDRESS: 1934 case DHO_DHCP_SERVER_IDENTIFIER: 1935 case DHO_ROUTER_SOLICITATION_ADDRESS: 1936 case DHO_DHCP_REQUESTED_ADDRESS: 1937 if (ipv4addrs(opbuf) == 0) { 1938 warning("Invalid IP address in option %s: %s", 1939 dhcp_options[option].name, opbuf); 1940 return (0); 1941 } 1942 if (l->options[option].len != 4) { /* RFC 2132 */ 1943 warning("warning: Only 1 IP address allowed in " 1944 "%s option; length %d, must be 4", 1945 dhcp_options[option].name, 1946 l->options[option].len); 1947 l->options[option].len = 4; 1948 } 1949 return (1); 1950 case DHO_TIME_SERVERS: 1951 case DHO_NAME_SERVERS: 1952 case DHO_ROUTERS: 1953 case DHO_DOMAIN_NAME_SERVERS: 1954 case DHO_LOG_SERVERS: 1955 case DHO_COOKIE_SERVERS: 1956 case DHO_LPR_SERVERS: 1957 case DHO_IMPRESS_SERVERS: 1958 case DHO_RESOURCE_LOCATION_SERVERS: 1959 case DHO_NIS_SERVERS: 1960 case DHO_NTP_SERVERS: 1961 case DHO_NETBIOS_NAME_SERVERS: 1962 case DHO_NETBIOS_DD_SERVER: 1963 case DHO_FONT_SERVERS: 1964 if (ipv4addrs(opbuf) == 0) { 1965 warning("Invalid IP address in option %s: %s", 1966 dhcp_options[option].name, opbuf); 1967 return (0); 1968 } 1969 return (1); 1970 case DHO_HOST_NAME: 1971 case DHO_DOMAIN_NAME: 1972 case DHO_NIS_DOMAIN: 1973 if (!res_hnok(sbuf)) { 1974 warning("Bogus Host Name option %d: %s (%s)", option, 1975 sbuf, opbuf); 1976 l->options[option].len = 0; 1977 free(l->options[option].data); 1978 } 1979 return (1); 1980 case DHO_PAD: 1981 case DHO_TIME_OFFSET: 1982 case DHO_BOOT_SIZE: 1983 case DHO_MERIT_DUMP: 1984 case DHO_ROOT_PATH: 1985 case DHO_EXTENSIONS_PATH: 1986 case DHO_IP_FORWARDING: 1987 case DHO_NON_LOCAL_SOURCE_ROUTING: 1988 case DHO_POLICY_FILTER: 1989 case DHO_MAX_DGRAM_REASSEMBLY: 1990 case DHO_DEFAULT_IP_TTL: 1991 case DHO_PATH_MTU_AGING_TIMEOUT: 1992 case DHO_PATH_MTU_PLATEAU_TABLE: 1993 case DHO_INTERFACE_MTU: 1994 case DHO_ALL_SUBNETS_LOCAL: 1995 case DHO_PERFORM_MASK_DISCOVERY: 1996 case DHO_MASK_SUPPLIER: 1997 case DHO_ROUTER_DISCOVERY: 1998 case DHO_STATIC_ROUTES: 1999 case DHO_TRAILER_ENCAPSULATION: 2000 case DHO_ARP_CACHE_TIMEOUT: 2001 case DHO_IEEE802_3_ENCAPSULATION: 2002 case DHO_DEFAULT_TCP_TTL: 2003 case DHO_TCP_KEEPALIVE_INTERVAL: 2004 case DHO_TCP_KEEPALIVE_GARBAGE: 2005 case DHO_VENDOR_ENCAPSULATED_OPTIONS: 2006 case DHO_NETBIOS_NODE_TYPE: 2007 case DHO_NETBIOS_SCOPE: 2008 case DHO_X_DISPLAY_MANAGER: 2009 case DHO_DHCP_LEASE_TIME: 2010 case DHO_DHCP_OPTION_OVERLOAD: 2011 case DHO_DHCP_MESSAGE_TYPE: 2012 case DHO_DHCP_PARAMETER_REQUEST_LIST: 2013 case DHO_DHCP_MESSAGE: 2014 case DHO_DHCP_MAX_MESSAGE_SIZE: 2015 case DHO_DHCP_RENEWAL_TIME: 2016 case DHO_DHCP_REBINDING_TIME: 2017 case DHO_DHCP_CLASS_IDENTIFIER: 2018 case DHO_DHCP_CLIENT_IDENTIFIER: 2019 case DHO_DHCP_USER_CLASS_ID: 2020 case DHO_TFTP_SERVER: 2021 case DHO_END: 2022 return (1); 2023 default: 2024 if (!unknown_ok) 2025 warning("unknown dhcp option value 0x%x", option); 2026 return (unknown_ok); 2027 } 2028 } 2029 2030 int 2031 res_hnok(const char *name) 2032 { 2033 const char *dn = name; 2034 int pch = '.', ch = *dn++; 2035 int warn = 0; 2036 2037 while (ch != '\0') { 2038 int nch = *dn++; 2039 2040 if (ch == '.') { 2041 ; 2042 } else if (pch == '.' || nch == '.' || nch == '\0') { 2043 if (!isalnum(ch)) 2044 return (0); 2045 } else if (!isalnum(ch) && ch != '-' && ch != '_') 2046 return (0); 2047 else if (ch == '_' && warn == 0) { 2048 warning("warning: hostname %s contains an " 2049 "underscore which violates RFC 952", name); 2050 warn++; 2051 } 2052 pch = ch, ch = nch; 2053 } 2054 return (1); 2055 } 2056 2057 /* Does buf consist only of dotted decimal ipv4 addrs? 2058 * return how many if so, 2059 * otherwise, return 0 2060 */ 2061 int 2062 ipv4addrs(char * buf) 2063 { 2064 struct in_addr jnk; 2065 int count = 0; 2066 2067 while (inet_aton(buf, &jnk) == 1){ 2068 count++; 2069 while (*buf == '.' || isdigit(*buf)) 2070 buf++; 2071 if (*buf == '\0') 2072 return (count); 2073 while (*buf == ' ') 2074 buf++; 2075 } 2076 return (0); 2077 } 2078 2079 char * 2080 option_as_string(unsigned int code, unsigned char *data, int len) 2081 { 2082 static char optbuf[32768]; /* XXX */ 2083 char *op = optbuf; 2084 int opleft = sizeof(optbuf); 2085 unsigned char *dp = data; 2086 2087 if (code > 255) 2088 error("option_as_string: bad code %d", code); 2089 2090 for (; dp < data + len; dp++) { 2091 if (!isascii(*dp) || !isprint(*dp)) { 2092 if (dp + 1 != data + len || *dp != 0) { 2093 size_t oplen; 2094 snprintf(op, opleft, "\\%03o", *dp); 2095 oplen = strlen(op); 2096 op += oplen; 2097 opleft -= oplen; 2098 } 2099 } else if (*dp == '"' || *dp == '\'' || *dp == '$' || 2100 *dp == '`' || *dp == '\\') { 2101 *op++ = '\\'; 2102 *op++ = *dp; 2103 opleft -= 2; 2104 } else { 2105 *op++ = *dp; 2106 opleft--; 2107 } 2108 } 2109 if (opleft < 1) 2110 goto toobig; 2111 *op = 0; 2112 return optbuf; 2113 toobig: 2114 warning("dhcp option too large"); 2115 return "<error>"; 2116 } 2117 2118 int 2119 fork_privchld(int fd, int fd2) 2120 { 2121 struct pollfd pfd[1]; 2122 int nfds, pfail = 0; 2123 pid_t pid; 2124 int omask; 2125 2126 omask = sigblock(sigmask(SIGINT)|sigmask(SIGHUP)); 2127 pid = fork(); 2128 if (pid > 0) 2129 monitor_pid = pid; 2130 sigsetmask(omask); 2131 2132 switch (pid) { 2133 case -1: 2134 error("cannot fork"); 2135 break; 2136 case 0: 2137 break; 2138 default: 2139 return (0); 2140 } 2141 2142 if (chdir("/") == -1) 2143 error("chdir(\"/\")"); 2144 2145 setproctitle("%s [priv]", ifi->name); 2146 2147 dup2(nullfd, STDIN_FILENO); 2148 dup2(nullfd, STDOUT_FILENO); 2149 dup2(nullfd, STDERR_FILENO); 2150 close(nullfd); 2151 close(fd2); 2152 2153 for (;;) { 2154 pfd[0].fd = fd; 2155 pfd[0].events = POLLIN; 2156 if ((nfds = poll(pfd, 1, INFTIM)) == -1) 2157 if (errno != EINTR) 2158 error("poll error"); 2159 2160 /* 2161 * Handle temporary errors, but bail if they persist. 2162 */ 2163 if (nfds == 0 || !(pfd[0].revents & POLLIN)) { 2164 if (pfail > POLL_FAILURES) 2165 error("poll failed > %d times", POLL_FAILURES); 2166 sleep(pfail * POLL_FAILURE_WAIT); 2167 pfail++; 2168 continue; 2169 } 2170 2171 dispatch_imsg(fd); 2172 } 2173 } 2174 2175 void 2176 get_ifname(char *ifname, char *arg) 2177 { 2178 struct ifgroupreq ifgr; 2179 struct ifg_req *ifg; 2180 int s, len; 2181 2182 if (!strcmp(arg, "egress")) { 2183 s = socket(AF_INET, SOCK_DGRAM, 0); 2184 if (s == -1) 2185 error("socket error"); 2186 bzero(&ifgr, sizeof(ifgr)); 2187 strlcpy(ifgr.ifgr_name, "egress", sizeof(ifgr.ifgr_name)); 2188 if (ioctl(s, SIOCGIFGMEMB, (caddr_t)&ifgr) == -1) { 2189 if (errno == ENOENT) 2190 error("no interface in group egress found"); 2191 error("ioctl SIOCGIFGMEMB: %m"); 2192 } 2193 len = ifgr.ifgr_len; 2194 if ((ifgr.ifgr_groups = calloc(1, len)) == NULL) 2195 error("get_ifname"); 2196 if (ioctl(s, SIOCGIFGMEMB, (caddr_t)&ifgr) == -1) 2197 error("ioctl SIOCGIFGMEMB: %m"); 2198 2199 arg = NULL; 2200 for (ifg = ifgr.ifgr_groups; 2201 ifg && len >= sizeof(struct ifg_req); ifg++) { 2202 len -= sizeof(struct ifg_req); 2203 if (arg) 2204 error("too many interfaces in group egress"); 2205 arg = ifg->ifgrq_member; 2206 } 2207 2208 if (strlcpy(ifi->name, arg, IFNAMSIZ) >= IFNAMSIZ) 2209 error("Interface name too long: %m"); 2210 2211 free(ifgr.ifgr_groups); 2212 close(s); 2213 } else if (strlcpy(ifi->name, arg, IFNAMSIZ) >= IFNAMSIZ) 2214 error("Interface name too long"); 2215 } 2216 2217 static 2218 void 2219 sig_handle(int signo) 2220 { 2221 if (monitor_pid > 0) 2222 kill(monitor_pid, signo); 2223 fprintf(stderr, "killed by signal\n"); 2224 exit(1); 2225 } 2226 2227 static 2228 int 2229 killclient(int fd) 2230 { 2231 int noclient = 1; 2232 2233 /* 2234 * Kill previously running dhclient 2235 */ 2236 if (flock(fd, LOCK_EX|LOCK_NB) < 0) { 2237 char buf[256]; 2238 ssize_t n; 2239 pid_t pid; 2240 2241 lseek(fd, 0L, SEEK_SET); 2242 n = read(fd, buf, sizeof(buf)); 2243 if (n > 0) { 2244 buf[n-1] = 0; 2245 pid = strtol(buf, NULL, 10); 2246 if ((int)pid > 0) { 2247 noclient = 0; 2248 kill(pid, SIGINT); 2249 } 2250 } 2251 if (flock(fd, LOCK_EX|LOCK_NB) < 0) 2252 usleep(20000); 2253 while (flock(fd, LOCK_EX|LOCK_NB) < 0) 2254 sleep(1); 2255 } 2256 return noclient; 2257 } 2258