1 /************************************************************************ 2 Copyright 1988, 1991 by Carnegie Mellon University 3 4 All Rights Reserved 5 6 Permission to use, copy, modify, and distribute this software and its 7 documentation for any purpose and without fee is hereby granted, provided 8 that the above copyright notice appear in all copies and that both that 9 copyright notice and this permission notice appear in supporting 10 documentation, and that the name of Carnegie Mellon University not be used 11 in advertising or publicity pertaining to distribution of the software 12 without specific, written prior permission. 13 14 CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS 15 SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. 16 IN NO EVENT SHALL CMU BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL 17 DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 18 PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 19 ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 20 SOFTWARE. 21 22 $FreeBSD$ 23 24 ************************************************************************/ 25 26 /* 27 * BOOTP (bootstrap protocol) server daemon. 28 * 29 * Answers BOOTP request packets from booting client machines. 30 * See [SRI-NIC]<RFC>RFC951.TXT for a description of the protocol. 31 * See [SRI-NIC]<RFC>RFC1048.TXT for vendor-information extensions. 32 * See RFC 1395 for option tags 14-17. 33 * See accompanying man page -- bootpd.8 34 * 35 * HISTORY 36 * See ./Changes 37 * 38 * BUGS 39 * See ./ToDo 40 */ 41 42 43 44 #include <sys/types.h> 45 #include <sys/param.h> 46 #include <sys/socket.h> 47 #include <sys/ioctl.h> 48 #include <sys/file.h> 49 #include <sys/time.h> 50 #include <sys/stat.h> 51 #include <sys/utsname.h> 52 53 #include <net/if.h> 54 #include <netinet/in.h> 55 #include <arpa/inet.h> /* inet_ntoa */ 56 57 #ifndef NO_UNISTD 58 #include <unistd.h> 59 #endif 60 61 #include <stdlib.h> 62 #include <signal.h> 63 #include <stdio.h> 64 #include <string.h> 65 #include <errno.h> 66 #include <ctype.h> 67 #include <netdb.h> 68 #include <paths.h> 69 #include <syslog.h> 70 #include <assert.h> 71 72 #ifdef NO_SETSID 73 # include <fcntl.h> /* for O_RDONLY, etc */ 74 #endif 75 76 #ifndef USE_BFUNCS 77 # include <memory.h> 78 /* Yes, memcpy is OK here (no overlapped copies). */ 79 # define bcopy(a,b,c) memcpy(b,a,c) 80 # define bzero(p,l) memset(p,0,l) 81 # define bcmp(a,b,c) memcmp(a,b,c) 82 #endif 83 84 #include "bootp.h" 85 #include "hash.h" 86 #include "hwaddr.h" 87 #include "bootpd.h" 88 #include "dovend.h" 89 #include "getif.h" 90 #include "readfile.h" 91 #include "report.h" 92 #include "tzone.h" 93 #include "patchlevel.h" 94 95 #ifndef CONFIG_FILE 96 #define CONFIG_FILE "/etc/bootptab" 97 #endif 98 #ifndef DUMPTAB_FILE 99 #define DUMPTAB_FILE "/tmp/bootpd.dump" 100 #endif 101 102 103 104 /* 105 * Externals, forward declarations, and global variables 106 */ 107 108 extern void dumptab(char *); 109 110 PRIVATE void catcher(int); 111 PRIVATE int chk_access(char *, int32 *); 112 #ifdef VEND_CMU 113 PRIVATE void dovend_cmu(struct bootp *, struct host *); 114 #endif 115 PRIVATE void dovend_rfc1048(struct bootp *, struct host *, int32); 116 PRIVATE void handle_reply(void); 117 PRIVATE void handle_request(void); 118 PRIVATE void sendreply(int forward, int32 dest_override); 119 PRIVATE void usage(void); 120 121 /* 122 * IP port numbers for client and server obtained from /etc/services 123 */ 124 125 u_short bootps_port, bootpc_port; 126 127 128 /* 129 * Internet socket and interface config structures 130 */ 131 132 struct sockaddr_in bind_addr; /* Listening */ 133 struct sockaddr_in recv_addr; /* Packet source */ 134 struct sockaddr_in send_addr; /* destination */ 135 136 137 /* 138 * option defaults 139 */ 140 int debug = 0; /* Debugging flag (level) */ 141 struct timeval actualtimeout = 142 { /* fifteen minutes */ 143 15 * 60L, /* tv_sec */ 144 0 /* tv_usec */ 145 }; 146 147 /* 148 * General 149 */ 150 151 int s; /* Socket file descriptor */ 152 char *pktbuf; /* Receive packet buffer */ 153 int pktlen; 154 char *progname; 155 char *chdir_path; 156 struct in_addr my_ip_addr; 157 158 static const char *hostname; 159 static char default_hostname[MAXHOSTNAMELEN]; 160 161 /* Flags set by signal catcher. */ 162 PRIVATE int do_readtab = 0; 163 PRIVATE int do_dumptab = 0; 164 165 /* 166 * Globals below are associated with the bootp database file (bootptab). 167 */ 168 169 char *bootptab = CONFIG_FILE; 170 char *bootpd_dump = DUMPTAB_FILE; 171 172 173 174 /* 175 * Initialization such as command-line processing is done and then the 176 * main server loop is started. 177 */ 178 179 int 180 main(argc, argv) 181 int argc; 182 char **argv; 183 { 184 struct timeval *timeout; 185 struct bootp *bp; 186 struct servent *servp; 187 struct hostent *hep; 188 char *stmp; 189 int n, ba_len, ra_len; 190 int nfound, readfds; 191 int standalone; 192 #ifdef SA_NOCLDSTOP /* Have POSIX sigaction(2). */ 193 struct sigaction sa; 194 #endif 195 196 progname = strrchr(argv[0], '/'); 197 if (progname) progname++; 198 else progname = argv[0]; 199 200 /* 201 * Initialize logging. 202 */ 203 report_init(0); /* uses progname */ 204 205 /* 206 * Log startup 207 */ 208 report(LOG_INFO, "version %s.%d", VERSION, PATCHLEVEL); 209 210 /* Debugging for compilers with struct padding. */ 211 assert(sizeof(struct bootp) == BP_MINPKTSZ); 212 213 /* Get space for receiving packets and composing replies. */ 214 pktbuf = malloc(MAX_MSG_SIZE); 215 if (!pktbuf) { 216 report(LOG_ERR, "malloc failed"); 217 exit(1); 218 } 219 bp = (struct bootp *) pktbuf; 220 221 /* 222 * Check to see if a socket was passed to us from inetd. 223 * 224 * Use getsockname() to determine if descriptor 0 is indeed a socket 225 * (and thus we are probably a child of inetd) or if it is instead 226 * something else and we are running standalone. 227 */ 228 s = 0; 229 ba_len = sizeof(bind_addr); 230 bzero((char *) &bind_addr, ba_len); 231 errno = 0; 232 standalone = TRUE; 233 if (getsockname(s, (struct sockaddr *) &bind_addr, &ba_len) == 0) { 234 /* 235 * Descriptor 0 is a socket. Assume we are a child of inetd. 236 */ 237 if (bind_addr.sin_family == AF_INET) { 238 standalone = FALSE; 239 bootps_port = ntohs(bind_addr.sin_port); 240 } else { 241 /* Some other type of socket? */ 242 report(LOG_ERR, "getsockname: not an INET socket"); 243 } 244 } 245 246 /* 247 * Set defaults that might be changed by option switches. 248 */ 249 stmp = NULL; 250 timeout = &actualtimeout; 251 252 if (gethostname(default_hostname, sizeof(default_hostname) - 1) < 0) { 253 report(LOG_ERR, "bootpd: can't get hostname\n"); 254 exit(1); 255 } 256 default_hostname[sizeof(default_hostname) - 1] = '\0'; 257 hostname = default_hostname; 258 259 /* 260 * Read switches. 261 */ 262 for (argc--, argv++; argc > 0; argc--, argv++) { 263 if (argv[0][0] != '-') 264 break; 265 switch (argv[0][1]) { 266 267 case 'c': /* chdir_path */ 268 if (argv[0][2]) { 269 stmp = &(argv[0][2]); 270 } else { 271 argc--; 272 argv++; 273 stmp = argv[0]; 274 } 275 if (!stmp || (stmp[0] != '/')) { 276 report(LOG_ERR, 277 "bootpd: invalid chdir specification\n"); 278 break; 279 } 280 chdir_path = stmp; 281 break; 282 283 case 'd': /* debug level */ 284 if (argv[0][2]) { 285 stmp = &(argv[0][2]); 286 } else if (argv[1] && argv[1][0] == '-') { 287 /* 288 * Backwards-compatible behavior: 289 * no parameter, so just increment the debug flag. 290 */ 291 debug++; 292 break; 293 } else { 294 argc--; 295 argv++; 296 stmp = argv[0]; 297 } 298 if (!stmp || (sscanf(stmp, "%d", &n) != 1) || (n < 0)) { 299 report(LOG_ERR, 300 "%s: invalid debug level\n", progname); 301 break; 302 } 303 debug = n; 304 break; 305 306 case 'h': /* override hostname */ 307 if (argv[0][2]) { 308 stmp = &(argv[0][2]); 309 } else { 310 argc--; 311 argv++; 312 stmp = argv[0]; 313 } 314 if (!stmp) { 315 report(LOG_ERR, 316 "bootpd: missing hostname\n"); 317 break; 318 } 319 hostname = stmp; 320 break; 321 322 case 'i': /* inetd mode */ 323 standalone = FALSE; 324 break; 325 326 case 's': /* standalone mode */ 327 standalone = TRUE; 328 break; 329 330 case 't': /* timeout */ 331 if (argv[0][2]) { 332 stmp = &(argv[0][2]); 333 } else { 334 argc--; 335 argv++; 336 stmp = argv[0]; 337 } 338 if (!stmp || (sscanf(stmp, "%d", &n) != 1) || (n < 0)) { 339 report(LOG_ERR, 340 "%s: invalid timeout specification\n", progname); 341 break; 342 } 343 actualtimeout.tv_sec = (int32) (60 * n); 344 /* 345 * If the actual timeout is zero, pass a NULL pointer 346 * to select so it blocks indefinitely, otherwise, 347 * point to the actual timeout value. 348 */ 349 timeout = (n > 0) ? &actualtimeout : NULL; 350 break; 351 352 default: 353 report(LOG_ERR, "%s: unknown switch: -%c\n", 354 progname, argv[0][1]); 355 usage(); 356 break; 357 358 } /* switch */ 359 } /* for args */ 360 361 /* 362 * Override default file names if specified on the command line. 363 */ 364 if (argc > 0) 365 bootptab = argv[0]; 366 367 if (argc > 1) 368 bootpd_dump = argv[1]; 369 370 /* 371 * Get my hostname and IP address. 372 */ 373 374 hep = gethostbyname(hostname); 375 if (!hep) { 376 report(LOG_ERR, "Can not get my IP address\n"); 377 exit(1); 378 } 379 bcopy(hep->h_addr, (char *)&my_ip_addr, sizeof(my_ip_addr)); 380 381 if (standalone) { 382 /* 383 * Go into background and disassociate from controlling terminal. 384 */ 385 if (debug < 3) { 386 if (fork()) 387 exit(0); 388 #ifdef NO_SETSID 389 setpgrp(0,0); 390 #ifdef TIOCNOTTY 391 n = open(_PATH_TTY, O_RDWR); 392 if (n >= 0) { 393 ioctl(n, TIOCNOTTY, (char *) 0); 394 (void) close(n); 395 } 396 #endif /* TIOCNOTTY */ 397 #else /* SETSID */ 398 if (setsid() < 0) 399 perror("setsid"); 400 #endif /* SETSID */ 401 } /* if debug < 3 */ 402 403 /* 404 * Nuke any timeout value 405 */ 406 timeout = NULL; 407 408 } /* if standalone (1st) */ 409 410 /* Set the cwd (i.e. to /tftpboot) */ 411 if (chdir_path) { 412 if (chdir(chdir_path) < 0) 413 report(LOG_ERR, "%s: chdir failed", chdir_path); 414 } 415 416 /* Get the timezone. */ 417 tzone_init(); 418 419 /* Allocate hash tables. */ 420 rdtab_init(); 421 422 /* 423 * Read the bootptab file. 424 */ 425 readtab(1); /* force read */ 426 427 if (standalone) { 428 429 /* 430 * Create a socket. 431 */ 432 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 433 report(LOG_ERR, "socket: %s", get_network_errmsg()); 434 exit(1); 435 } 436 437 /* 438 * Get server's listening port number 439 */ 440 servp = getservbyname("bootps", "udp"); 441 if (servp) { 442 bootps_port = ntohs((u_short) servp->s_port); 443 } else { 444 bootps_port = (u_short) IPPORT_BOOTPS; 445 report(LOG_ERR, 446 "udp/bootps: unknown service -- assuming port %d", 447 bootps_port); 448 } 449 450 /* 451 * Bind socket to BOOTPS port. 452 */ 453 bind_addr.sin_family = AF_INET; 454 bind_addr.sin_addr.s_addr = INADDR_ANY; 455 bind_addr.sin_port = htons(bootps_port); 456 if (bind(s, (struct sockaddr *) &bind_addr, 457 sizeof(bind_addr)) < 0) 458 { 459 report(LOG_ERR, "bind: %s", get_network_errmsg()); 460 exit(1); 461 } 462 } /* if standalone (2nd)*/ 463 464 /* 465 * Get destination port number so we can reply to client 466 */ 467 servp = getservbyname("bootpc", "udp"); 468 if (servp) { 469 bootpc_port = ntohs(servp->s_port); 470 } else { 471 report(LOG_ERR, 472 "udp/bootpc: unknown service -- assuming port %d", 473 IPPORT_BOOTPC); 474 bootpc_port = (u_short) IPPORT_BOOTPC; 475 } 476 477 /* 478 * Set up signals to read or dump the table. 479 */ 480 #ifdef SA_NOCLDSTOP /* Have POSIX sigaction(2). */ 481 sa.sa_handler = catcher; 482 sigemptyset(&sa.sa_mask); 483 sa.sa_flags = 0; 484 if (sigaction(SIGHUP, &sa, NULL) < 0) { 485 report(LOG_ERR, "sigaction: %s", get_errmsg()); 486 exit(1); 487 } 488 if (sigaction(SIGUSR1, &sa, NULL) < 0) { 489 report(LOG_ERR, "sigaction: %s", get_errmsg()); 490 exit(1); 491 } 492 #else /* SA_NOCLDSTOP */ 493 /* Old-fashioned UNIX signals */ 494 if ((int) signal(SIGHUP, catcher) < 0) { 495 report(LOG_ERR, "signal: %s", get_errmsg()); 496 exit(1); 497 } 498 if ((int) signal(SIGUSR1, catcher) < 0) { 499 report(LOG_ERR, "signal: %s", get_errmsg()); 500 exit(1); 501 } 502 #endif /* SA_NOCLDSTOP */ 503 504 /* 505 * Process incoming requests. 506 */ 507 for (;;) { 508 struct timeval tv; 509 510 readfds = 1 << s; 511 if (timeout) 512 tv = *timeout; 513 514 nfound = select(s + 1, (fd_set *)&readfds, NULL, NULL, 515 (timeout) ? &tv : NULL); 516 if (nfound < 0) { 517 if (errno != EINTR) { 518 report(LOG_ERR, "select: %s", get_errmsg()); 519 } 520 /* 521 * Call readtab() or dumptab() here to avoid the 522 * dangers of doing I/O from a signal handler. 523 */ 524 if (do_readtab) { 525 do_readtab = 0; 526 readtab(1); /* force read */ 527 } 528 if (do_dumptab) { 529 do_dumptab = 0; 530 dumptab(bootpd_dump); 531 } 532 continue; 533 } 534 if (!(readfds & (1 << s))) { 535 if (debug > 1) 536 report(LOG_INFO, "exiting after %ld minutes of inactivity", 537 actualtimeout.tv_sec / 60); 538 exit(0); 539 } 540 ra_len = sizeof(recv_addr); 541 n = recvfrom(s, pktbuf, MAX_MSG_SIZE, 0, 542 (struct sockaddr *) &recv_addr, &ra_len); 543 if (n <= 0) { 544 continue; 545 } 546 if (debug > 1) { 547 report(LOG_INFO, "recvd pkt from IP addr %s", 548 inet_ntoa(recv_addr.sin_addr)); 549 } 550 if (n < sizeof(struct bootp)) { 551 if (debug) { 552 report(LOG_NOTICE, "received short packet"); 553 } 554 continue; 555 } 556 pktlen = n; 557 558 readtab(0); /* maybe re-read bootptab */ 559 560 switch (bp->bp_op) { 561 case BOOTREQUEST: 562 handle_request(); 563 break; 564 case BOOTREPLY: 565 handle_reply(); 566 break; 567 } 568 } 569 return 0; 570 } 571 572 573 574 575 /* 576 * Print "usage" message and exit 577 */ 578 579 PRIVATE void 580 usage() 581 { 582 fprintf(stderr, 583 "usage: bootpd [-d level] [-i] [-s] [-t timeout] [configfile [dumpfile]]\n"); 584 fprintf(stderr, "\t -c n\tset current directory\n"); 585 fprintf(stderr, "\t -d n\tset debug level\n"); 586 fprintf(stderr, "\t -i\tforce inetd mode (run as child of inetd)\n"); 587 fprintf(stderr, "\t -s\tforce standalone mode (run without inetd)\n"); 588 fprintf(stderr, "\t -t n\tset inetd exit timeout to n minutes\n"); 589 exit(1); 590 } 591 592 /* Signal catchers */ 593 PRIVATE void 594 catcher(sig) 595 int sig; 596 { 597 if (sig == SIGHUP) 598 do_readtab = 1; 599 if (sig == SIGUSR1) 600 do_dumptab = 1; 601 #if !defined(SA_NOCLDSTOP) && defined(SYSV) 602 /* For older "System V" derivatives with no sigaction(). */ 603 signal(sig, catcher); 604 #endif 605 } 606 607 608 609 /* 610 * Process BOOTREQUEST packet. 611 * 612 * Note: This version of the bootpd.c server never forwards 613 * a request to another server. That is the job of a gateway 614 * program such as the "bootpgw" program included here. 615 * 616 * (Also this version does not interpret the hostname field of 617 * the request packet; it COULD do a name->address lookup and 618 * forward the request there.) 619 */ 620 PRIVATE void 621 handle_request() 622 { 623 struct bootp *bp = (struct bootp *) pktbuf; 624 struct host *hp = NULL; 625 struct host dummyhost; 626 int32 bootsize = 0; 627 unsigned hlen, hashcode; 628 int32 dest; 629 char realpath[1024]; 630 char *clntpath; 631 char *homedir, *bootfile; 632 int n; 633 634 bp->bp_file[sizeof(bp->bp_file)-1] = '\0'; 635 636 /* XXX - SLIP init: Set bp_ciaddr = recv_addr here? */ 637 638 /* 639 * If the servername field is set, compare it against us. 640 * If we're not being addressed, ignore this request. 641 * If the server name field is null, throw in our name. 642 */ 643 if (strlen(bp->bp_sname)) { 644 if (strcmp(bp->bp_sname, hostname)) { 645 if (debug) 646 report(LOG_INFO, "\ 647 ignoring request for server %s from client at %s address %s", 648 bp->bp_sname, netname(bp->bp_htype), 649 haddrtoa(bp->bp_chaddr, bp->bp_hlen)); 650 /* XXX - Is it correct to ignore such a request? -gwr */ 651 return; 652 } 653 } else { 654 strcpy(bp->bp_sname, hostname); 655 } 656 657 /* Convert the request into a reply. */ 658 bp->bp_op = BOOTREPLY; 659 if (bp->bp_ciaddr.s_addr == 0) { 660 /* 661 * client doesnt know his IP address, 662 * search by hardware address. 663 */ 664 if (debug > 1) { 665 report(LOG_INFO, "request from %s address %s", 666 netname(bp->bp_htype), 667 haddrtoa(bp->bp_chaddr, bp->bp_hlen)); 668 } 669 hlen = haddrlength(bp->bp_htype); 670 if (hlen != bp->bp_hlen) { 671 report(LOG_NOTICE, "bad addr len from from %s address %s", 672 netname(bp->bp_htype), 673 haddrtoa(bp->bp_chaddr, hlen)); 674 } 675 dummyhost.htype = bp->bp_htype; 676 bcopy(bp->bp_chaddr, dummyhost.haddr, hlen); 677 hashcode = hash_HashFunction(bp->bp_chaddr, hlen); 678 hp = (struct host *) hash_Lookup(hwhashtable, hashcode, hwlookcmp, 679 &dummyhost); 680 if (hp == NULL && 681 bp->bp_htype == HTYPE_IEEE802) 682 { 683 /* Try again with address in "canonical" form. */ 684 haddr_conv802(bp->bp_chaddr, dummyhost.haddr, hlen); 685 if (debug > 1) { 686 report(LOG_INFO, "\ 687 HW addr type is IEEE 802. convert to %s and check again\n", 688 haddrtoa(dummyhost.haddr, bp->bp_hlen)); 689 } 690 hashcode = hash_HashFunction(dummyhost.haddr, hlen); 691 hp = (struct host *) hash_Lookup(hwhashtable, hashcode, 692 hwlookcmp, &dummyhost); 693 } 694 if (hp == NULL) { 695 /* 696 * XXX - Add dynamic IP address assignment? 697 */ 698 if (debug) 699 report(LOG_NOTICE, "unknown client %s address %s", 700 netname(bp->bp_htype), 701 haddrtoa(bp->bp_chaddr, bp->bp_hlen)); 702 return; /* not found */ 703 } 704 (bp->bp_yiaddr).s_addr = hp->iaddr.s_addr; 705 706 } else { 707 708 /* 709 * search by IP address. 710 */ 711 if (debug > 1) { 712 report(LOG_INFO, "request from IP addr %s", 713 inet_ntoa(bp->bp_ciaddr)); 714 } 715 dummyhost.iaddr.s_addr = bp->bp_ciaddr.s_addr; 716 hashcode = hash_HashFunction((u_char *) &(bp->bp_ciaddr.s_addr), 4); 717 hp = (struct host *) hash_Lookup(iphashtable, hashcode, iplookcmp, 718 &dummyhost); 719 if (hp == NULL) { 720 if (debug) { 721 report(LOG_NOTICE, "IP address not found: %s", 722 inet_ntoa(bp->bp_ciaddr)); 723 } 724 return; 725 } 726 } 727 728 if (debug) { 729 report(LOG_INFO, "found %s (%s)", inet_ntoa(hp->iaddr), 730 hp->hostname->string); 731 } 732 733 /* 734 * If there is a response delay threshold, ignore requests 735 * with a timestamp lower than the threshold. 736 */ 737 if (hp->flags.min_wait) { 738 u_int32 t = (u_int32) ntohs(bp->bp_secs); 739 if (t < hp->min_wait) { 740 if (debug > 1) 741 report(LOG_INFO, 742 "ignoring request due to timestamp (%d < %d)", 743 t, hp->min_wait); 744 return; 745 } 746 } 747 748 #ifdef YORK_EX_OPTION 749 /* 750 * The need for the "ex" tag arose out of the need to empty 751 * shared networked drives on diskless PCs. This solution is 752 * not very clean but it does work fairly well. 753 * Written by Edmund J. Sutcliffe <edmund@york.ac.uk> 754 * 755 * XXX - This could compromise security if a non-trusted user 756 * managed to write an entry in the bootptab with :ex=trojan: 757 * so I would leave this turned off unless you need it. -gwr 758 */ 759 /* Run a program, passing the client name as a parameter. */ 760 if (hp->flags.exec_file) { 761 char tst[100]; 762 /* XXX - Check string lengths? -gwr */ 763 strcpy (tst, hp->exec_file->string); 764 strcat (tst, " "); 765 strcat (tst, hp->hostname->string); 766 strcat (tst, " &"); 767 if (debug) 768 report(LOG_INFO, "executing %s", tst); 769 system(tst); /* Hope this finishes soon... */ 770 } 771 #endif /* YORK_EX_OPTION */ 772 773 /* 774 * If a specific TFTP server address was specified in the bootptab file, 775 * fill it in, otherwise zero it. 776 * XXX - Rather than zero it, should it be the bootpd address? -gwr 777 */ 778 (bp->bp_siaddr).s_addr = (hp->flags.bootserver) ? 779 hp->bootserver.s_addr : 0L; 780 781 #ifdef STANFORD_PROM_COMPAT 782 /* 783 * Stanford bootp PROMs (for a Sun?) have no way to leave 784 * the boot file name field blank (because the boot file 785 * name is automatically generated from some index). 786 * As a work-around, this little hack allows those PROMs to 787 * specify "sunboot14" with the same effect as a NULL name. 788 * (The user specifies boot device 14 or some such magic.) 789 */ 790 if (strcmp(bp->bp_file, "sunboot14") == 0) 791 bp->bp_file[0] = '\0'; /* treat it as unspecified */ 792 #endif 793 794 /* 795 * Fill in the client's proper bootfile. 796 * 797 * If the client specifies an absolute path, try that file with a 798 * ".host" suffix and then without. If the file cannot be found, no 799 * reply is made at all. 800 * 801 * If the client specifies a null or relative file, use the following 802 * table to determine the appropriate action: 803 * 804 * Homedir Bootfile Client's file 805 * specified? specified? specification Action 806 * ------------------------------------------------------------------- 807 * No No Null Send null filename 808 * No No Relative Discard request 809 * No Yes Null Send if absolute else null 810 * No Yes Relative Discard request *XXX 811 * Yes No Null Send null filename 812 * Yes No Relative Lookup with ".host" 813 * Yes Yes Null Send home/boot or bootfile 814 * Yes Yes Relative Lookup with ".host" *XXX 815 * 816 */ 817 818 /* 819 * XXX - I don't like the policy of ignoring a client when the 820 * boot file is not accessible. The TFTP server might not be 821 * running on the same machine as the BOOTP server, in which 822 * case checking accessibility of the boot file is pointless. 823 * 824 * Therefore, file accessibility is now demanded ONLY if you 825 * define CHECK_FILE_ACCESS in the Makefile options. -gwr 826 */ 827 828 /* 829 * The "real" path is as seen by the BOOTP daemon on this 830 * machine, while the client path is relative to the TFTP 831 * daemon chroot directory (i.e. /tftpboot). 832 */ 833 if (hp->flags.tftpdir) { 834 snprintf(realpath, sizeof(realpath), "%s", hp->tftpdir->string); 835 clntpath = &realpath[strlen(realpath)]; 836 } else { 837 realpath[0] = '\0'; 838 clntpath = realpath; 839 } 840 841 /* 842 * Determine client's requested homedir and bootfile. 843 */ 844 homedir = NULL; 845 bootfile = NULL; 846 if (bp->bp_file[0]) { 847 homedir = bp->bp_file; 848 bootfile = strrchr(homedir, '/'); 849 if (bootfile) { 850 if (homedir == bootfile) 851 homedir = NULL; 852 *bootfile++ = '\0'; 853 } else { 854 /* no "/" in the string */ 855 bootfile = homedir; 856 homedir = NULL; 857 } 858 if (debug > 2) { 859 report(LOG_INFO, "requested path=\"%s\" file=\"%s\"", 860 (homedir) ? homedir : "", 861 (bootfile) ? bootfile : ""); 862 } 863 } 864 865 /* 866 * Specifications in bootptab override client requested values. 867 */ 868 if (hp->flags.homedir) 869 homedir = hp->homedir->string; 870 if (hp->flags.bootfile) 871 bootfile = hp->bootfile->string; 872 873 /* 874 * Construct bootfile path. 875 */ 876 if (homedir) { 877 if (homedir[0] != '/') 878 strcat(clntpath, "/"); 879 strcat(clntpath, homedir); 880 homedir = NULL; 881 } 882 if (bootfile) { 883 if (bootfile[0] != '/') 884 strcat(clntpath, "/"); 885 strcat(clntpath, bootfile); 886 bootfile = NULL; 887 } 888 889 /* 890 * First try to find the file with a ".host" suffix 891 */ 892 n = strlen(clntpath); 893 strcat(clntpath, "."); 894 strcat(clntpath, hp->hostname->string); 895 if (chk_access(realpath, &bootsize) < 0) { 896 clntpath[n] = 0; /* Try it without the suffix */ 897 if (chk_access(realpath, &bootsize) < 0) { 898 /* neither "file.host" nor "file" was found */ 899 #ifdef CHECK_FILE_ACCESS 900 901 if (bp->bp_file[0]) { 902 /* 903 * Client wanted specific file 904 * and we didn't have it. 905 */ 906 report(LOG_NOTICE, 907 "requested file not found: \"%s\"", clntpath); 908 return; 909 } 910 /* 911 * Client didn't ask for a specific file and we couldn't 912 * access the default file, so just zero-out the bootfile 913 * field in the packet and continue processing the reply. 914 */ 915 bzero(bp->bp_file, sizeof(bp->bp_file)); 916 goto null_file_name; 917 918 #else /* CHECK_FILE_ACCESS */ 919 920 /* Complain only if boot file size was needed. */ 921 if (hp->flags.bootsize_auto) { 922 report(LOG_ERR, "can not determine size of file \"%s\"", 923 clntpath); 924 } 925 926 #endif /* CHECK_FILE_ACCESS */ 927 } 928 } 929 strncpy(bp->bp_file, clntpath, BP_FILE_LEN); 930 if (debug > 2) 931 report(LOG_INFO, "bootfile=\"%s\"", clntpath); 932 933 #ifdef CHECK_FILE_ACCESS 934 null_file_name: 935 #endif /* CHECK_FILE_ACCESS */ 936 937 938 /* 939 * Handle vendor options based on magic number. 940 */ 941 942 if (debug > 1) { 943 report(LOG_INFO, "vendor magic field is %d.%d.%d.%d", 944 (int) ((bp->bp_vend)[0]), 945 (int) ((bp->bp_vend)[1]), 946 (int) ((bp->bp_vend)[2]), 947 (int) ((bp->bp_vend)[3])); 948 } 949 /* 950 * If this host isn't set for automatic vendor info then copy the 951 * specific cookie into the bootp packet, thus forcing a certain 952 * reply format. Only force reply format if user specified it. 953 */ 954 if (hp->flags.vm_cookie) { 955 /* Slam in the user specified magic number. */ 956 bcopy(hp->vm_cookie, bp->bp_vend, 4); 957 } 958 /* 959 * Figure out the format for the vendor-specific info. 960 * Note that bp->bp_vend may have been set above. 961 */ 962 if (!bcmp(bp->bp_vend, vm_rfc1048, 4)) { 963 /* RFC1048 conformant bootp client */ 964 dovend_rfc1048(bp, hp, bootsize); 965 if (debug > 1) { 966 report(LOG_INFO, "sending reply (with RFC1048 options)"); 967 } 968 } 969 #ifdef VEND_CMU 970 else if (!bcmp(bp->bp_vend, vm_cmu, 4)) { 971 dovend_cmu(bp, hp); 972 if (debug > 1) { 973 report(LOG_INFO, "sending reply (with CMU options)"); 974 } 975 } 976 #endif 977 else { 978 if (debug > 1) { 979 report(LOG_INFO, "sending reply (with no options)"); 980 } 981 } 982 983 dest = (hp->flags.reply_addr) ? 984 hp->reply_addr.s_addr : 0L; 985 986 /* not forwarded */ 987 sendreply(0, dest); 988 } 989 990 991 /* 992 * Process BOOTREPLY packet. 993 */ 994 PRIVATE void 995 handle_reply() 996 { 997 if (debug) { 998 report(LOG_INFO, "processing boot reply"); 999 } 1000 /* forwarded, no destination override */ 1001 sendreply(1, 0); 1002 } 1003 1004 1005 /* 1006 * Send a reply packet to the client. 'forward' flag is set if we are 1007 * not the originator of this reply packet. 1008 */ 1009 PRIVATE void 1010 sendreply(forward, dst_override) 1011 int forward; 1012 int32 dst_override; 1013 { 1014 struct bootp *bp = (struct bootp *) pktbuf; 1015 struct in_addr dst; 1016 u_short port = bootpc_port; 1017 unsigned char *ha; 1018 int len, haf; 1019 1020 /* 1021 * XXX - Should honor bp_flags "broadcast" bit here. 1022 * Temporary workaround: use the :ra=ADDR: option to 1023 * set the reply address to the broadcast address. 1024 */ 1025 1026 /* 1027 * If the destination address was specified explicitly 1028 * (i.e. the broadcast address for HP compatiblity) 1029 * then send the response to that address. Otherwise, 1030 * act in accordance with RFC951: 1031 * If the client IP address is specified, use that 1032 * else if gateway IP address is specified, use that 1033 * else make a temporary arp cache entry for the client's 1034 * NEW IP/hardware address and use that. 1035 */ 1036 if (dst_override) { 1037 dst.s_addr = dst_override; 1038 if (debug > 1) { 1039 report(LOG_INFO, "reply address override: %s", 1040 inet_ntoa(dst)); 1041 } 1042 } else if (bp->bp_ciaddr.s_addr) { 1043 dst = bp->bp_ciaddr; 1044 } else if (bp->bp_giaddr.s_addr && forward == 0) { 1045 dst = bp->bp_giaddr; 1046 port = bootps_port; 1047 if (debug > 1) { 1048 report(LOG_INFO, "sending reply to gateway %s", 1049 inet_ntoa(dst)); 1050 } 1051 } else { 1052 dst = bp->bp_yiaddr; 1053 ha = bp->bp_chaddr; 1054 len = bp->bp_hlen; 1055 if (len > MAXHADDRLEN) 1056 len = MAXHADDRLEN; 1057 haf = (int) bp->bp_htype; 1058 if (haf == 0) 1059 haf = HTYPE_ETHERNET; 1060 1061 if (debug > 1) 1062 report(LOG_INFO, "setarp %s - %s", 1063 inet_ntoa(dst), haddrtoa(ha, len)); 1064 setarp(s, &dst, haf, ha, len); 1065 } 1066 1067 if ((forward == 0) && 1068 (bp->bp_siaddr.s_addr == 0)) 1069 { 1070 struct ifreq *ifr; 1071 struct in_addr siaddr; 1072 /* 1073 * If we are originating this reply, we 1074 * need to find our own interface address to 1075 * put in the bp_siaddr field of the reply. 1076 * If this server is multi-homed, pick the 1077 * 'best' interface (the one on the same net 1078 * as the client). Of course, the client may 1079 * be on the other side of a BOOTP gateway... 1080 */ 1081 ifr = getif(s, &dst); 1082 if (ifr) { 1083 struct sockaddr_in *sip; 1084 sip = (struct sockaddr_in *) &(ifr->ifr_addr); 1085 siaddr = sip->sin_addr; 1086 } else { 1087 /* Just use my "official" IP address. */ 1088 siaddr = my_ip_addr; 1089 } 1090 1091 /* XXX - No need to set bp_giaddr here. */ 1092 1093 /* Finally, set the server address field. */ 1094 bp->bp_siaddr = siaddr; 1095 } 1096 /* Set up socket address for send. */ 1097 send_addr.sin_family = AF_INET; 1098 send_addr.sin_port = htons(port); 1099 send_addr.sin_addr = dst; 1100 1101 /* Send reply with same size packet as request used. */ 1102 if (sendto(s, pktbuf, pktlen, 0, 1103 (struct sockaddr *) &send_addr, 1104 sizeof(send_addr)) < 0) 1105 { 1106 report(LOG_ERR, "sendto: %s", get_network_errmsg()); 1107 } 1108 } /* sendreply */ 1109 1110 1111 /* nmatch() - now in getif.c */ 1112 /* setarp() - now in hwaddr.c */ 1113 1114 1115 /* 1116 * This call checks read access to a file. It returns 0 if the file given 1117 * by "path" exists and is publically readable. A value of -1 is returned if 1118 * access is not permitted or an error occurs. Successful calls also 1119 * return the file size in bytes using the long pointer "filesize". 1120 * 1121 * The read permission bit for "other" users is checked. This bit must be 1122 * set for tftpd(8) to allow clients to read the file. 1123 */ 1124 1125 PRIVATE int 1126 chk_access(path, filesize) 1127 char *path; 1128 int32 *filesize; 1129 { 1130 struct stat st; 1131 1132 if ((stat(path, &st) == 0) && (st.st_mode & (S_IREAD >> 6))) { 1133 *filesize = (int32) st.st_size; 1134 return 0; 1135 } else { 1136 return -1; 1137 } 1138 } 1139 1140 1141 /* 1142 * Now in dumptab.c : 1143 * dumptab() 1144 * dump_host() 1145 * list_ipaddresses() 1146 */ 1147 1148 #ifdef VEND_CMU 1149 1150 /* 1151 * Insert the CMU "vendor" data for the host pointed to by "hp" into the 1152 * bootp packet pointed to by "bp". 1153 */ 1154 1155 PRIVATE void 1156 dovend_cmu(bp, hp) 1157 struct bootp *bp; 1158 struct host *hp; 1159 { 1160 struct cmu_vend *vendp; 1161 struct in_addr_list *taddr; 1162 1163 /* 1164 * Initialize the entire vendor field to zeroes. 1165 */ 1166 bzero(bp->bp_vend, sizeof(bp->bp_vend)); 1167 1168 /* 1169 * Fill in vendor information. Subnet mask, default gateway, 1170 * domain name server, ien name server, time server 1171 */ 1172 vendp = (struct cmu_vend *) bp->bp_vend; 1173 strcpy(vendp->v_magic, (char *)vm_cmu); 1174 if (hp->flags.subnet_mask) { 1175 (vendp->v_smask).s_addr = hp->subnet_mask.s_addr; 1176 (vendp->v_flags) |= VF_SMASK; 1177 if (hp->flags.gateway) { 1178 (vendp->v_dgate).s_addr = hp->gateway->addr->s_addr; 1179 } 1180 } 1181 if (hp->flags.domain_server) { 1182 taddr = hp->domain_server; 1183 if (taddr->addrcount > 0) { 1184 (vendp->v_dns1).s_addr = (taddr->addr)[0].s_addr; 1185 if (taddr->addrcount > 1) { 1186 (vendp->v_dns2).s_addr = (taddr->addr)[1].s_addr; 1187 } 1188 } 1189 } 1190 if (hp->flags.name_server) { 1191 taddr = hp->name_server; 1192 if (taddr->addrcount > 0) { 1193 (vendp->v_ins1).s_addr = (taddr->addr)[0].s_addr; 1194 if (taddr->addrcount > 1) { 1195 (vendp->v_ins2).s_addr = (taddr->addr)[1].s_addr; 1196 } 1197 } 1198 } 1199 if (hp->flags.time_server) { 1200 taddr = hp->time_server; 1201 if (taddr->addrcount > 0) { 1202 (vendp->v_ts1).s_addr = (taddr->addr)[0].s_addr; 1203 if (taddr->addrcount > 1) { 1204 (vendp->v_ts2).s_addr = (taddr->addr)[1].s_addr; 1205 } 1206 } 1207 } 1208 /* Log message now done by caller. */ 1209 } /* dovend_cmu */ 1210 1211 #endif /* VEND_CMU */ 1212 1213 1214 1215 /* 1216 * Insert the RFC1048 vendor data for the host pointed to by "hp" into the 1217 * bootp packet pointed to by "bp". 1218 */ 1219 #define NEED(LEN, MSG) do \ 1220 if (bytesleft < (LEN)) { \ 1221 report(LOG_NOTICE, noroom, \ 1222 hp->hostname->string, MSG); \ 1223 return; \ 1224 } while (0) 1225 PRIVATE void 1226 dovend_rfc1048(bp, hp, bootsize) 1227 struct bootp *bp; 1228 struct host *hp; 1229 int32 bootsize; 1230 { 1231 int bytesleft, len; 1232 byte *vp; 1233 1234 static const char noroom[] = "%s: No room for \"%s\" option"; 1235 1236 vp = bp->bp_vend; 1237 1238 if (hp->flags.msg_size) { 1239 pktlen = hp->msg_size; 1240 } else { 1241 /* 1242 * If the request was longer than the official length, build 1243 * a response of that same length where the additional length 1244 * is assumed to be part of the bp_vend (options) area. 1245 */ 1246 if (pktlen > sizeof(*bp)) { 1247 if (debug > 1) 1248 report(LOG_INFO, "request message length=%d", pktlen); 1249 } 1250 /* 1251 * Check whether the request contains the option: 1252 * Maximum DHCP Message Size (RFC1533 sec. 9.8) 1253 * and if so, override the response length with its value. 1254 * This request must lie within the first BP_VEND_LEN 1255 * bytes of the option space. 1256 */ 1257 { 1258 byte *p, *ep; 1259 byte tag, len; 1260 short msgsz = 0; 1261 1262 p = vp + 4; 1263 ep = p + BP_VEND_LEN - 4; 1264 while (p < ep) { 1265 tag = *p++; 1266 /* Check for tags with no data first. */ 1267 if (tag == TAG_PAD) 1268 continue; 1269 if (tag == TAG_END) 1270 break; 1271 /* Now scan the length byte. */ 1272 len = *p++; 1273 switch (tag) { 1274 case TAG_MAX_MSGSZ: 1275 if (len == 2) { 1276 bcopy(p, (char*)&msgsz, 2); 1277 msgsz = ntohs(msgsz); 1278 } 1279 break; 1280 case TAG_SUBNET_MASK: 1281 /* XXX - Should preserve this if given... */ 1282 break; 1283 } /* swtich */ 1284 p += len; 1285 } 1286 1287 if (msgsz > sizeof(*bp) + BP_MSG_OVERHEAD) { 1288 if (debug > 1) 1289 report(LOG_INFO, "request has DHCP msglen=%d", msgsz); 1290 pktlen = msgsz - BP_MSG_OVERHEAD; 1291 } 1292 } 1293 } 1294 1295 if (pktlen < sizeof(*bp)) { 1296 report(LOG_ERR, "invalid response length=%d", pktlen); 1297 pktlen = sizeof(*bp); 1298 } 1299 bytesleft = ((byte*)bp + pktlen) - vp; 1300 if (pktlen > sizeof(*bp)) { 1301 if (debug > 1) 1302 report(LOG_INFO, "extended reply, length=%d, options=%d", 1303 pktlen, bytesleft); 1304 } 1305 1306 /* Copy in the magic cookie */ 1307 bcopy(vm_rfc1048, vp, 4); 1308 vp += 4; 1309 bytesleft -= 4; 1310 1311 if (hp->flags.subnet_mask) { 1312 /* always enough room here. */ 1313 *vp++ = TAG_SUBNET_MASK;/* -1 byte */ 1314 *vp++ = 4; /* -1 byte */ 1315 insert_u_long(hp->subnet_mask.s_addr, &vp); /* -4 bytes */ 1316 bytesleft -= 6; /* Fix real count */ 1317 if (hp->flags.gateway) { 1318 (void) insert_ip(TAG_GATEWAY, 1319 hp->gateway, 1320 &vp, &bytesleft); 1321 } 1322 } 1323 if (hp->flags.bootsize) { 1324 /* always enough room here */ 1325 bootsize = (hp->flags.bootsize_auto) ? 1326 ((bootsize + 511) / 512) : (hp->bootsize); /* Round up */ 1327 *vp++ = TAG_BOOT_SIZE; 1328 *vp++ = 2; 1329 *vp++ = (byte) ((bootsize >> 8) & 0xFF); 1330 *vp++ = (byte) (bootsize & 0xFF); 1331 bytesleft -= 4; /* Tag, length, and 16 bit blocksize */ 1332 } 1333 /* 1334 * This one is special: Remaining options go in the ext file. 1335 * Only the subnet_mask, bootsize, and gateway should precede. 1336 */ 1337 if (hp->flags.exten_file) { 1338 /* 1339 * Check for room for exten_file. Add 3 to account for 1340 * TAG_EXTEN_FILE, length, and TAG_END. 1341 */ 1342 len = strlen(hp->exten_file->string); 1343 NEED((len + 3), "ef"); 1344 *vp++ = TAG_EXTEN_FILE; 1345 *vp++ = (byte) (len & 0xFF); 1346 bcopy(hp->exten_file->string, vp, len); 1347 vp += len; 1348 *vp++ = TAG_END; 1349 bytesleft -= len + 3; 1350 return; /* no more options here. */ 1351 } 1352 /* 1353 * The remaining options are inserted by the following 1354 * function (which is shared with bootpef.c). 1355 * Keep back one byte for the TAG_END. 1356 */ 1357 len = dovend_rfc1497(hp, vp, bytesleft - 1); 1358 vp += len; 1359 bytesleft -= len; 1360 1361 /* There should be at least one byte left. */ 1362 NEED(1, "(end)"); 1363 *vp++ = TAG_END; 1364 bytesleft--; 1365 1366 /* Log message done by caller. */ 1367 if (bytesleft > 0) { 1368 /* 1369 * Zero out any remaining part of the vendor area. 1370 */ 1371 bzero(vp, bytesleft); 1372 } 1373 } /* dovend_rfc1048 */ 1374 #undef NEED 1375 1376 1377 /* 1378 * Now in readfile.c: 1379 * hwlookcmp() 1380 * iplookcmp() 1381 */ 1382 1383 /* haddrtoa() - now in hwaddr.c */ 1384 /* 1385 * Now in dovend.c: 1386 * insert_ip() 1387 * insert_generic() 1388 * insert_u_long() 1389 */ 1390 1391 /* get_errmsg() - now in report.c */ 1392 1393 /* 1394 * Local Variables: 1395 * tab-width: 4 1396 * c-indent-level: 4 1397 * c-argdecl-indent: 4 1398 * c-continued-statement-offset: 4 1399 * c-continued-brace-offset: -4 1400 * c-label-offset: -4 1401 * c-brace-offset: 0 1402 * End: 1403 */ 1404