xtables.c revision 39bf9c8214d3073a496a8a1eff91046a8d6fbbdf
1/* 2 * (C) 2000-2006 by the netfilter coreteam <coreteam@netfilter.org>: 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 17 */ 18 19#include <errno.h> 20#include <fcntl.h> 21#include <netdb.h> 22#include <stdarg.h> 23#include <stdbool.h> 24#include <stdio.h> 25#include <stdlib.h> 26#include <string.h> 27#include <unistd.h> 28#include <sys/socket.h> 29#include <sys/stat.h> 30#include <sys/types.h> 31#include <sys/wait.h> 32#include <arpa/inet.h> 33 34#include <xtables.h> 35#include <libiptc/libxtc.h> 36 37#ifndef NO_SHARED_LIBS 38#include <dlfcn.h> 39#endif 40 41#define NPROTO 255 42 43#ifndef PROC_SYS_MODPROBE 44#define PROC_SYS_MODPROBE "/proc/sys/kernel/modprobe" 45#endif 46 47/* Search path for Xtables .so files */ 48static const char *xtables_libdir; 49 50/* the path to command to load kernel module */ 51const char *xtables_modprobe_program; 52 53/* Keeping track of external matches and targets: linked lists. */ 54struct xtables_match *xtables_matches; 55struct xtables_target *xtables_targets; 56 57void xtables_init(void) 58{ 59 xtables_libdir = getenv("XTABLES_LIBDIR"); 60 if (xtables_libdir != NULL) 61 return; 62 xtables_libdir = getenv("IPTABLES_LIB_DIR"); 63 if (xtables_libdir != NULL) { 64 fprintf(stderr, "IPTABLES_LIB_DIR is deprecated, " 65 "use XTABLES_LIBDIR.\n"); 66 return; 67 } 68 xtables_libdir = XTABLES_LIBDIR; 69} 70 71/** 72 * xtables_*alloc - wrappers that exit on failure 73 */ 74void *xtables_calloc(size_t count, size_t size) 75{ 76 void *p; 77 78 if ((p = calloc(count, size)) == NULL) { 79 perror("ip[6]tables: calloc failed"); 80 exit(1); 81 } 82 83 return p; 84} 85 86void *xtables_malloc(size_t size) 87{ 88 void *p; 89 90 if ((p = malloc(size)) == NULL) { 91 perror("ip[6]tables: malloc failed"); 92 exit(1); 93 } 94 95 return p; 96} 97 98static char *get_modprobe(void) 99{ 100 int procfile; 101 char *ret; 102 103#define PROCFILE_BUFSIZ 1024 104 procfile = open(PROC_SYS_MODPROBE, O_RDONLY); 105 if (procfile < 0) 106 return NULL; 107 108 ret = (char *) malloc(PROCFILE_BUFSIZ); 109 if (ret) { 110 memset(ret, 0, PROCFILE_BUFSIZ); 111 switch (read(procfile, ret, PROCFILE_BUFSIZ)) { 112 case -1: goto fail; 113 case PROCFILE_BUFSIZ: goto fail; /* Partial read. Wierd */ 114 } 115 if (ret[strlen(ret)-1]=='\n') 116 ret[strlen(ret)-1]=0; 117 close(procfile); 118 return ret; 119 } 120 fail: 121 free(ret); 122 close(procfile); 123 return NULL; 124} 125 126int xtables_insmod(const char *modname, const char *modprobe, bool quiet) 127{ 128 char *buf = NULL; 129 char *argv[4]; 130 int status; 131 132 /* If they don't explicitly set it, read out of kernel */ 133 if (!modprobe) { 134 buf = get_modprobe(); 135 if (!buf) 136 return -1; 137 modprobe = buf; 138 } 139 140 switch (fork()) { 141 case 0: 142 argv[0] = (char *)modprobe; 143 argv[1] = (char *)modname; 144 if (quiet) { 145 argv[2] = "-q"; 146 argv[3] = NULL; 147 } else { 148 argv[2] = NULL; 149 argv[3] = NULL; 150 } 151 execv(argv[0], argv); 152 153 /* not usually reached */ 154 exit(1); 155 case -1: 156 return -1; 157 158 default: /* parent */ 159 wait(&status); 160 } 161 162 free(buf); 163 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) 164 return 0; 165 return -1; 166} 167 168int xtables_load_ko(const char *modprobe, bool quiet) 169{ 170 static bool loaded = false; 171 static int ret = -1; 172 173 if (!loaded) { 174 ret = xtables_insmod(afinfo.kmod, modprobe, quiet); 175 loaded = (ret == 0); 176 } 177 178 return ret; 179} 180 181int string_to_number_ll(const char *s, unsigned long long min, 182 unsigned long long max, unsigned long long *ret) 183{ 184 unsigned long long number; 185 char *end; 186 187 /* Handle hex, octal, etc. */ 188 errno = 0; 189 number = strtoull(s, &end, 0); 190 if (*end == '\0' && end != s) { 191 /* we parsed a number, let's see if we want this */ 192 if (errno != ERANGE && min <= number && (!max || number <= max)) { 193 *ret = number; 194 return 0; 195 } 196 } 197 return -1; 198} 199 200int string_to_number_l(const char *s, unsigned long min, unsigned long max, 201 unsigned long *ret) 202{ 203 int result; 204 unsigned long long number; 205 206 result = string_to_number_ll(s, min, max, &number); 207 *ret = (unsigned long)number; 208 209 return result; 210} 211 212int string_to_number(const char *s, unsigned int min, unsigned int max, 213 unsigned int *ret) 214{ 215 int result; 216 unsigned long number; 217 218 result = string_to_number_l(s, min, max, &number); 219 *ret = (unsigned int)number; 220 221 return result; 222} 223 224/* 225 * strtonum{,l} - string to number conversion 226 * 227 * If @end is NULL, we assume the caller does not want 228 * a case like "15a", so reject it. 229 */ 230bool strtonuml(const char *s, char **end, unsigned long *value, 231 unsigned long min, unsigned long max) 232{ 233 unsigned long v; 234 char *my_end; 235 236 errno = 0; 237 v = strtoul(s, &my_end, 0); 238 239 if (my_end == s) 240 return false; 241 if (end != NULL) 242 *end = my_end; 243 244 if (errno != ERANGE && min <= v && (max == 0 || v <= max)) { 245 if (value != NULL) 246 *value = v; 247 if (end == NULL) 248 return *my_end == '\0'; 249 return true; 250 } 251 252 return false; 253} 254 255bool strtonum(const char *s, char **end, unsigned int *value, 256 unsigned int min, unsigned int max) 257{ 258 unsigned long v; 259 bool ret; 260 261 ret = strtonuml(s, end, &v, min, max); 262 if (value != NULL) 263 *value = v; 264 return ret; 265} 266 267int service_to_port(const char *name, const char *proto) 268{ 269 struct servent *service; 270 271 if ((service = getservbyname(name, proto)) != NULL) 272 return ntohs((unsigned short) service->s_port); 273 274 return -1; 275} 276 277u_int16_t parse_port(const char *port, const char *proto) 278{ 279 unsigned int portnum; 280 281 if (string_to_number(port, 0, UINT16_MAX, &portnum) != -1 || 282 (portnum = service_to_port(port, proto)) != (unsigned)-1) 283 return portnum; 284 285 exit_error(PARAMETER_PROBLEM, 286 "invalid port/service `%s' specified", port); 287} 288 289void parse_interface(const char *arg, char *vianame, unsigned char *mask) 290{ 291 int vialen = strlen(arg); 292 unsigned int i; 293 294 memset(mask, 0, IFNAMSIZ); 295 memset(vianame, 0, IFNAMSIZ); 296 297 if (vialen + 1 > IFNAMSIZ) 298 exit_error(PARAMETER_PROBLEM, 299 "interface name `%s' must be shorter than IFNAMSIZ" 300 " (%i)", arg, IFNAMSIZ-1); 301 302 strcpy(vianame, arg); 303 if ((vialen == 0) || (vialen == 1 && vianame[0] == '+')) 304 memset(mask, 0, IFNAMSIZ); 305 else if (vianame[vialen - 1] == '+') { 306 memset(mask, 0xFF, vialen - 1); 307 memset(mask + vialen - 1, 0, IFNAMSIZ - vialen + 1); 308 /* Don't remove `+' here! -HW */ 309 } else { 310 /* Include nul-terminator in match */ 311 memset(mask, 0xFF, vialen + 1); 312 memset(mask + vialen + 1, 0, IFNAMSIZ - vialen - 1); 313 for (i = 0; vianame[i]; i++) { 314 if (vianame[i] == ':' || 315 vianame[i] == '!' || 316 vianame[i] == '*') { 317 fprintf(stderr, 318 "Warning: weird character in interface" 319 " `%s' (No aliases, :, ! or *).\n", 320 vianame); 321 break; 322 } 323 } 324 } 325} 326 327#ifndef NO_SHARED_LIBS 328static void *load_extension(const char *search_path, const char *prefix, 329 const char *name, bool is_target) 330{ 331 const char *dir = search_path, *next; 332 void *ptr = NULL; 333 struct stat sb; 334 char path[256]; 335 336 do { 337 next = strchr(dir, ':'); 338 if (next == NULL) 339 next = dir + strlen(dir); 340 snprintf(path, sizeof(path), "%.*s/libxt_%s.so", 341 (unsigned int)(next - dir), dir, name); 342 343 if (dlopen(path, RTLD_NOW) != NULL) { 344 /* Found library. If it didn't register itself, 345 maybe they specified target as match. */ 346 if (is_target) 347 ptr = xtables_find_target(name, XTF_DONT_LOAD); 348 else 349 ptr = xtables_find_match(name, 350 XTF_DONT_LOAD, NULL); 351 } else if (stat(path, &sb) == 0) { 352 fprintf(stderr, "%s: %s\n", path, dlerror()); 353 } 354 355 if (ptr != NULL) 356 return ptr; 357 358 snprintf(path, sizeof(path), "%.*s/%s%s.so", 359 (unsigned int)(next - dir), dir, prefix, name); 360 if (dlopen(path, RTLD_NOW) != NULL) { 361 if (is_target) 362 ptr = xtables_find_target(name, XTF_DONT_LOAD); 363 else 364 ptr = xtables_find_match(name, 365 XTF_DONT_LOAD, NULL); 366 } else if (stat(path, &sb) == 0) { 367 fprintf(stderr, "%s: %s\n", path, dlerror()); 368 } 369 370 if (ptr != NULL) 371 return ptr; 372 373 dir = next + 1; 374 } while (*next != '\0'); 375 376 return NULL; 377} 378#endif 379 380struct xtables_match * 381xtables_find_match(const char *name, enum xtables_tryload tryload, 382 struct xtables_rule_match **matches) 383{ 384 struct xtables_match *ptr; 385 const char *icmp6 = "icmp6"; 386 387 /* This is ugly as hell. Nonetheless, there is no way of changing 388 * this without hurting backwards compatibility */ 389 if ( (strcmp(name,"icmpv6") == 0) || 390 (strcmp(name,"ipv6-icmp") == 0) || 391 (strcmp(name,"icmp6") == 0) ) 392 name = icmp6; 393 394 for (ptr = xtables_matches; ptr; ptr = ptr->next) { 395 if (strcmp(name, ptr->name) == 0) { 396 struct xtables_match *clone; 397 398 /* First match of this type: */ 399 if (ptr->m == NULL) 400 break; 401 402 /* Second and subsequent clones */ 403 clone = xtables_malloc(sizeof(struct xtables_match)); 404 memcpy(clone, ptr, sizeof(struct xtables_match)); 405 clone->mflags = 0; 406 /* This is a clone: */ 407 clone->next = clone; 408 409 ptr = clone; 410 break; 411 } 412 } 413 414#ifndef NO_SHARED_LIBS 415 if (!ptr && tryload != XTF_DONT_LOAD && tryload != XTF_DURING_LOAD) { 416 ptr = load_extension(xtables_libdir, afinfo.libprefix, 417 name, false); 418 419 if (ptr == NULL && tryload == XTF_LOAD_MUST_SUCCEED) 420 exit_error(PARAMETER_PROBLEM, 421 "Couldn't load match `%s':%s\n", 422 name, dlerror()); 423 } 424#else 425 if (ptr && !ptr->loaded) { 426 if (tryload != XTF_DONT_LOAD) 427 ptr->loaded = 1; 428 else 429 ptr = NULL; 430 } 431 if(!ptr && (tryload == XTF_LOAD_MUST_SUCCEED)) { 432 exit_error(PARAMETER_PROBLEM, 433 "Couldn't find match `%s'\n", name); 434 } 435#endif 436 437 if (ptr && matches) { 438 struct xtables_rule_match **i; 439 struct xtables_rule_match *newentry; 440 441 newentry = xtables_malloc(sizeof(struct xtables_rule_match)); 442 443 for (i = matches; *i; i = &(*i)->next) { 444 if (strcmp(name, (*i)->match->name) == 0) 445 (*i)->completed = true; 446 } 447 newentry->match = ptr; 448 newentry->completed = false; 449 newentry->next = NULL; 450 *i = newentry; 451 } 452 453 return ptr; 454} 455 456struct xtables_target * 457xtables_find_target(const char *name, enum xtables_tryload tryload) 458{ 459 struct xtables_target *ptr; 460 461 /* Standard target? */ 462 if (strcmp(name, "") == 0 463 || strcmp(name, XTC_LABEL_ACCEPT) == 0 464 || strcmp(name, XTC_LABEL_DROP) == 0 465 || strcmp(name, XTC_LABEL_QUEUE) == 0 466 || strcmp(name, XTC_LABEL_RETURN) == 0) 467 name = "standard"; 468 469 for (ptr = xtables_targets; ptr; ptr = ptr->next) { 470 if (strcmp(name, ptr->name) == 0) 471 break; 472 } 473 474#ifndef NO_SHARED_LIBS 475 if (!ptr && tryload != XTF_DONT_LOAD && tryload != XTF_DURING_LOAD) { 476 ptr = load_extension(xtables_libdir, afinfo.libprefix, 477 name, true); 478 479 if (ptr == NULL && tryload == XTF_LOAD_MUST_SUCCEED) 480 exit_error(PARAMETER_PROBLEM, 481 "Couldn't load target `%s':%s\n", 482 name, dlerror()); 483 } 484#else 485 if (ptr && !ptr->loaded) { 486 if (tryload != XTF_DONT_LOAD) 487 ptr->loaded = 1; 488 else 489 ptr = NULL; 490 } 491 if(!ptr && (tryload == LOAD_MUST_SUCCEED)) { 492 exit_error(PARAMETER_PROBLEM, 493 "Couldn't find target `%s'\n", name); 494 } 495#endif 496 497 if (ptr) 498 ptr->used = 1; 499 500 return ptr; 501} 502 503static int compatible_revision(const char *name, u_int8_t revision, int opt) 504{ 505 struct xt_get_revision rev; 506 socklen_t s = sizeof(rev); 507 int max_rev, sockfd; 508 509 sockfd = socket(afinfo.family, SOCK_RAW, IPPROTO_RAW); 510 if (sockfd < 0) { 511 if (errno == EPERM) { 512 /* revision 0 is always supported. */ 513 if (revision != 0) 514 fprintf(stderr, "Could not determine whether " 515 "revision %u is supported, " 516 "assuming it is.\n", 517 revision); 518 return 1; 519 } 520 fprintf(stderr, "Could not open socket to kernel: %s\n", 521 strerror(errno)); 522 exit(1); 523 } 524 525 xtables_load_ko(xtables_modprobe_program, true); 526 527 strcpy(rev.name, name); 528 rev.revision = revision; 529 530 max_rev = getsockopt(sockfd, afinfo.ipproto, opt, &rev, &s); 531 if (max_rev < 0) { 532 /* Definitely don't support this? */ 533 if (errno == ENOENT || errno == EPROTONOSUPPORT) { 534 close(sockfd); 535 return 0; 536 } else if (errno == ENOPROTOOPT) { 537 close(sockfd); 538 /* Assume only revision 0 support (old kernel) */ 539 return (revision == 0); 540 } else { 541 fprintf(stderr, "getsockopt failed strangely: %s\n", 542 strerror(errno)); 543 exit(1); 544 } 545 } 546 close(sockfd); 547 return 1; 548} 549 550 551static int compatible_match_revision(const char *name, u_int8_t revision) 552{ 553 return compatible_revision(name, revision, afinfo.so_rev_match); 554} 555 556static int compatible_target_revision(const char *name, u_int8_t revision) 557{ 558 return compatible_revision(name, revision, afinfo.so_rev_target); 559} 560 561void xtables_register_match(struct xtables_match *me) 562{ 563 struct xtables_match **i, *old; 564 565 if (strcmp(me->version, program_version) != 0) { 566 fprintf(stderr, "%s: match `%s' v%s (I'm v%s).\n", 567 program_name, me->name, me->version, program_version); 568 exit(1); 569 } 570 571 /* Revision field stole a char from name. */ 572 if (strlen(me->name) >= XT_FUNCTION_MAXNAMELEN-1) { 573 fprintf(stderr, "%s: target `%s' has invalid name\n", 574 program_name, me->name); 575 exit(1); 576 } 577 578 if (me->family >= NPROTO) { 579 fprintf(stderr, 580 "%s: BUG: match %s has invalid protocol family\n", 581 program_name, me->name); 582 exit(1); 583 } 584 585 /* ignore not interested match */ 586 if (me->family != afinfo.family && me->family != AF_UNSPEC) 587 return; 588 589 old = xtables_find_match(me->name, XTF_DURING_LOAD, NULL); 590 if (old) { 591 if (old->revision == me->revision && 592 old->family == me->family) { 593 fprintf(stderr, 594 "%s: match `%s' already registered.\n", 595 program_name, me->name); 596 exit(1); 597 } 598 599 /* Now we have two (or more) options, check compatibility. */ 600 if (compatible_match_revision(old->name, old->revision) 601 && old->revision > me->revision) 602 return; 603 604 /* See if new match can be used. */ 605 if (!compatible_match_revision(me->name, me->revision)) 606 return; 607 608 /* Prefer !AF_UNSPEC over AF_UNSPEC for same revision. */ 609 if (old->revision == me->revision && me->family == AF_UNSPEC) 610 return; 611 612 /* Delete old one. */ 613 for (i = &xtables_matches; *i!=old; i = &(*i)->next); 614 *i = old->next; 615 } 616 617 if (me->size != XT_ALIGN(me->size)) { 618 fprintf(stderr, "%s: match `%s' has invalid size %u.\n", 619 program_name, me->name, (unsigned int)me->size); 620 exit(1); 621 } 622 623 /* Append to list. */ 624 for (i = &xtables_matches; *i; i = &(*i)->next); 625 me->next = NULL; 626 *i = me; 627 628 me->m = NULL; 629 me->mflags = 0; 630} 631 632void xtables_register_target(struct xtables_target *me) 633{ 634 struct xtables_target *old; 635 636 if (strcmp(me->version, program_version) != 0) { 637 fprintf(stderr, "%s: target `%s' v%s (I'm v%s).\n", 638 program_name, me->name, me->version, program_version); 639 exit(1); 640 } 641 642 /* Revision field stole a char from name. */ 643 if (strlen(me->name) >= XT_FUNCTION_MAXNAMELEN-1) { 644 fprintf(stderr, "%s: target `%s' has invalid name\n", 645 program_name, me->name); 646 exit(1); 647 } 648 649 if (me->family >= NPROTO) { 650 fprintf(stderr, 651 "%s: BUG: target %s has invalid protocol family\n", 652 program_name, me->name); 653 exit(1); 654 } 655 656 /* ignore not interested target */ 657 if (me->family != afinfo.family && me->family != AF_UNSPEC) 658 return; 659 660 old = xtables_find_target(me->name, XTF_DURING_LOAD); 661 if (old) { 662 struct xtables_target **i; 663 664 if (old->revision == me->revision && 665 old->family == me->family) { 666 fprintf(stderr, 667 "%s: target `%s' already registered.\n", 668 program_name, me->name); 669 exit(1); 670 } 671 672 /* Now we have two (or more) options, check compatibility. */ 673 if (compatible_target_revision(old->name, old->revision) 674 && old->revision > me->revision) 675 return; 676 677 /* See if new target can be used. */ 678 if (!compatible_target_revision(me->name, me->revision)) 679 return; 680 681 /* Prefer !AF_UNSPEC over AF_UNSPEC for same revision. */ 682 if (old->revision == me->revision && me->family == AF_UNSPEC) 683 return; 684 685 /* Delete old one. */ 686 for (i = &xtables_targets; *i!=old; i = &(*i)->next); 687 *i = old->next; 688 } 689 690 if (me->size != XT_ALIGN(me->size)) { 691 fprintf(stderr, "%s: target `%s' has invalid size %u.\n", 692 program_name, me->name, (unsigned int)me->size); 693 exit(1); 694 } 695 696 /* Prepend to list. */ 697 me->next = xtables_targets; 698 xtables_targets = me; 699 me->t = NULL; 700 me->tflags = 0; 701} 702 703void param_act(unsigned int status, const char *p1, ...) 704{ 705 const char *p2, *p3; 706 va_list args; 707 bool b; 708 709 va_start(args, p1); 710 711 switch (status) { 712 case P_ONLY_ONCE: 713 p2 = va_arg(args, const char *); 714 b = va_arg(args, unsigned int); 715 if (!b) 716 return; 717 exit_error(PARAMETER_PROBLEM, 718 "%s: \"%s\" option may only be specified once", 719 p1, p2); 720 break; 721 case P_NO_INVERT: 722 p2 = va_arg(args, const char *); 723 b = va_arg(args, unsigned int); 724 if (!b) 725 return; 726 exit_error(PARAMETER_PROBLEM, 727 "%s: \"%s\" option cannot be inverted", p1, p2); 728 break; 729 case P_BAD_VALUE: 730 p2 = va_arg(args, const char *); 731 p3 = va_arg(args, const char *); 732 exit_error(PARAMETER_PROBLEM, 733 "%s: Bad value for \"%s\" option: \"%s\"", 734 p1, p2, p3); 735 break; 736 case P_ONE_ACTION: 737 b = va_arg(args, unsigned int); 738 if (!b) 739 return; 740 exit_error(PARAMETER_PROBLEM, 741 "%s: At most one action is possible", p1); 742 break; 743 default: 744 exit_error(status, p1, args); 745 break; 746 } 747 748 va_end(args); 749} 750 751const char *ipaddr_to_numeric(const struct in_addr *addrp) 752{ 753 static char buf[20]; 754 const unsigned char *bytep = (const void *)&addrp->s_addr; 755 756 sprintf(buf, "%u.%u.%u.%u", bytep[0], bytep[1], bytep[2], bytep[3]); 757 return buf; 758} 759 760static const char *ipaddr_to_host(const struct in_addr *addr) 761{ 762 struct hostent *host; 763 764 host = gethostbyaddr(addr, sizeof(struct in_addr), AF_INET); 765 if (host == NULL) 766 return NULL; 767 768 return host->h_name; 769} 770 771static const char *ipaddr_to_network(const struct in_addr *addr) 772{ 773 struct netent *net; 774 775 if ((net = getnetbyaddr(ntohl(addr->s_addr), AF_INET)) != NULL) 776 return net->n_name; 777 778 return NULL; 779} 780 781const char *ipaddr_to_anyname(const struct in_addr *addr) 782{ 783 const char *name; 784 785 if ((name = ipaddr_to_host(addr)) != NULL || 786 (name = ipaddr_to_network(addr)) != NULL) 787 return name; 788 789 return ipaddr_to_numeric(addr); 790} 791 792const char *ipmask_to_numeric(const struct in_addr *mask) 793{ 794 static char buf[20]; 795 uint32_t maskaddr, bits; 796 int i; 797 798 maskaddr = ntohl(mask->s_addr); 799 800 if (maskaddr == 0xFFFFFFFFL) 801 /* we don't want to see "/32" */ 802 return ""; 803 804 i = 32; 805 bits = 0xFFFFFFFEL; 806 while (--i >= 0 && maskaddr != bits) 807 bits <<= 1; 808 if (i >= 0) 809 sprintf(buf, "/%d", i); 810 else 811 /* mask was not a decent combination of 1's and 0's */ 812 sprintf(buf, "/%s", ipaddr_to_numeric(mask)); 813 814 return buf; 815} 816 817static struct in_addr *__numeric_to_ipaddr(const char *dotted, bool is_mask) 818{ 819 static struct in_addr addr; 820 unsigned char *addrp; 821 unsigned int onebyte; 822 char buf[20], *p, *q; 823 int i; 824 825 /* copy dotted string, because we need to modify it */ 826 strncpy(buf, dotted, sizeof(buf) - 1); 827 buf[sizeof(buf) - 1] = '\0'; 828 addrp = (void *)&addr.s_addr; 829 830 p = buf; 831 for (i = 0; i < 3; ++i) { 832 if ((q = strchr(p, '.')) == NULL) { 833 if (is_mask) 834 return NULL; 835 836 /* autocomplete, this is a network address */ 837 if (!strtonum(p, NULL, &onebyte, 0, UINT8_MAX)) 838 return NULL; 839 840 addrp[i] = onebyte; 841 while (i < 3) 842 addrp[++i] = 0; 843 844 return &addr; 845 } 846 847 *q = '\0'; 848 if (!strtonum(p, NULL, &onebyte, 0, UINT8_MAX)) 849 return NULL; 850 851 addrp[i] = onebyte; 852 p = q + 1; 853 } 854 855 /* we have checked 3 bytes, now we check the last one */ 856 if (!strtonum(p, NULL, &onebyte, 0, UINT8_MAX)) 857 return NULL; 858 859 addrp[3] = onebyte; 860 return &addr; 861} 862 863struct in_addr *numeric_to_ipaddr(const char *dotted) 864{ 865 return __numeric_to_ipaddr(dotted, false); 866} 867 868struct in_addr *numeric_to_ipmask(const char *dotted) 869{ 870 return __numeric_to_ipaddr(dotted, true); 871} 872 873static struct in_addr *network_to_ipaddr(const char *name) 874{ 875 static struct in_addr addr; 876 struct netent *net; 877 878 if ((net = getnetbyname(name)) != NULL) { 879 if (net->n_addrtype != AF_INET) 880 return NULL; 881 addr.s_addr = htonl(net->n_net); 882 return &addr; 883 } 884 885 return NULL; 886} 887 888static struct in_addr *host_to_ipaddr(const char *name, unsigned int *naddr) 889{ 890 struct hostent *host; 891 struct in_addr *addr; 892 unsigned int i; 893 894 *naddr = 0; 895 if ((host = gethostbyname(name)) != NULL) { 896 if (host->h_addrtype != AF_INET || 897 host->h_length != sizeof(struct in_addr)) 898 return NULL; 899 900 while (host->h_addr_list[*naddr] != NULL) 901 ++*naddr; 902 addr = xtables_calloc(*naddr, sizeof(struct in_addr) * *naddr); 903 for (i = 0; i < *naddr; i++) 904 memcpy(&addr[i], host->h_addr_list[i], 905 sizeof(struct in_addr)); 906 return addr; 907 } 908 909 return NULL; 910} 911 912static struct in_addr * 913ipparse_hostnetwork(const char *name, unsigned int *naddrs) 914{ 915 struct in_addr *addrptmp, *addrp; 916 917 if ((addrptmp = numeric_to_ipaddr(name)) != NULL || 918 (addrptmp = network_to_ipaddr(name)) != NULL) { 919 addrp = xtables_malloc(sizeof(struct in_addr)); 920 memcpy(addrp, addrptmp, sizeof(*addrp)); 921 *naddrs = 1; 922 return addrp; 923 } 924 if ((addrptmp = host_to_ipaddr(name, naddrs)) != NULL) 925 return addrptmp; 926 927 exit_error(PARAMETER_PROBLEM, "host/network `%s' not found", name); 928} 929 930static struct in_addr *parse_ipmask(const char *mask) 931{ 932 static struct in_addr maskaddr; 933 struct in_addr *addrp; 934 unsigned int bits; 935 936 if (mask == NULL) { 937 /* no mask at all defaults to 32 bits */ 938 maskaddr.s_addr = 0xFFFFFFFF; 939 return &maskaddr; 940 } 941 if ((addrp = numeric_to_ipmask(mask)) != NULL) 942 /* dotted_to_addr already returns a network byte order addr */ 943 return addrp; 944 if (string_to_number(mask, 0, 32, &bits) == -1) 945 exit_error(PARAMETER_PROBLEM, 946 "invalid mask `%s' specified", mask); 947 if (bits != 0) { 948 maskaddr.s_addr = htonl(0xFFFFFFFF << (32 - bits)); 949 return &maskaddr; 950 } 951 952 maskaddr.s_addr = 0U; 953 return &maskaddr; 954} 955 956void ipparse_hostnetworkmask(const char *name, struct in_addr **addrpp, 957 struct in_addr *maskp, unsigned int *naddrs) 958{ 959 unsigned int i, j, k, n; 960 struct in_addr *addrp; 961 char buf[256], *p; 962 963 strncpy(buf, name, sizeof(buf) - 1); 964 buf[sizeof(buf) - 1] = '\0'; 965 if ((p = strrchr(buf, '/')) != NULL) { 966 *p = '\0'; 967 addrp = parse_ipmask(p + 1); 968 } else { 969 addrp = parse_ipmask(NULL); 970 } 971 memcpy(maskp, addrp, sizeof(*maskp)); 972 973 /* if a null mask is given, the name is ignored, like in "any/0" */ 974 if (maskp->s_addr == 0U) 975 strcpy(buf, "0.0.0.0"); 976 977 addrp = *addrpp = ipparse_hostnetwork(buf, naddrs); 978 n = *naddrs; 979 for (i = 0, j = 0; i < n; ++i) { 980 addrp[j++].s_addr &= maskp->s_addr; 981 for (k = 0; k < j - 1; ++k) 982 if (addrp[k].s_addr == addrp[j-1].s_addr) { 983 --*naddrs; 984 --j; 985 break; 986 } 987 } 988} 989 990const char *ip6addr_to_numeric(const struct in6_addr *addrp) 991{ 992 /* 0000:0000:0000:0000:0000:000.000.000.000 993 * 0000:0000:0000:0000:0000:0000:0000:0000 */ 994 static char buf[50+1]; 995 return inet_ntop(AF_INET6, addrp, buf, sizeof(buf)); 996} 997 998static const char *ip6addr_to_host(const struct in6_addr *addr) 999{ 1000 static char hostname[NI_MAXHOST]; 1001 struct sockaddr_in6 saddr; 1002 int err; 1003 1004 memset(&saddr, 0, sizeof(struct sockaddr_in6)); 1005 memcpy(&saddr.sin6_addr, addr, sizeof(*addr)); 1006 saddr.sin6_family = AF_INET6; 1007 1008 err = getnameinfo((const void *)&saddr, sizeof(struct sockaddr_in6), 1009 hostname, sizeof(hostname) - 1, NULL, 0, 0); 1010 if (err != 0) { 1011#ifdef DEBUG 1012 fprintf(stderr,"IP2Name: %s\n",gai_strerror(err)); 1013#endif 1014 return NULL; 1015 } 1016 1017#ifdef DEBUG 1018 fprintf (stderr, "\naddr2host: %s\n", hostname); 1019#endif 1020 return hostname; 1021} 1022 1023const char *ip6addr_to_anyname(const struct in6_addr *addr) 1024{ 1025 const char *name; 1026 1027 if ((name = ip6addr_to_host(addr)) != NULL) 1028 return name; 1029 1030 return ip6addr_to_numeric(addr); 1031} 1032 1033static int ip6addr_prefix_length(const struct in6_addr *k) 1034{ 1035 unsigned int bits = 0; 1036 uint32_t a, b, c, d; 1037 1038 a = ntohl(k->s6_addr32[0]); 1039 b = ntohl(k->s6_addr32[1]); 1040 c = ntohl(k->s6_addr32[2]); 1041 d = ntohl(k->s6_addr32[3]); 1042 while (a & 0x80000000U) { 1043 ++bits; 1044 a <<= 1; 1045 a |= (b >> 31) & 1; 1046 b <<= 1; 1047 b |= (c >> 31) & 1; 1048 c <<= 1; 1049 c |= (d >> 31) & 1; 1050 d <<= 1; 1051 } 1052 if (a != 0 || b != 0 || c != 0 || d != 0) 1053 return -1; 1054 return bits; 1055} 1056 1057const char *ip6mask_to_numeric(const struct in6_addr *addrp) 1058{ 1059 static char buf[50+2]; 1060 int l = ip6addr_prefix_length(addrp); 1061 1062 if (l == -1) { 1063 strcpy(buf, "/"); 1064 strcat(buf, ip6addr_to_numeric(addrp)); 1065 return buf; 1066 } 1067 sprintf(buf, "/%d", l); 1068 return buf; 1069} 1070 1071struct in6_addr *numeric_to_ip6addr(const char *num) 1072{ 1073 static struct in6_addr ap; 1074 int err; 1075 1076 if ((err = inet_pton(AF_INET6, num, &ap)) == 1) 1077 return ≈ 1078#ifdef DEBUG 1079 fprintf(stderr, "\nnumeric2addr: %d\n", err); 1080#endif 1081 return NULL; 1082} 1083 1084static struct in6_addr * 1085host_to_ip6addr(const char *name, unsigned int *naddr) 1086{ 1087 static struct in6_addr *addr; 1088 struct addrinfo hints; 1089 struct addrinfo *res; 1090 int err; 1091 1092 memset(&hints, 0, sizeof(hints)); 1093 hints.ai_flags = AI_CANONNAME; 1094 hints.ai_family = AF_INET6; 1095 hints.ai_socktype = SOCK_RAW; 1096 hints.ai_protocol = IPPROTO_IPV6; 1097 hints.ai_next = NULL; 1098 1099 *naddr = 0; 1100 if ((err = getaddrinfo(name, NULL, &hints, &res)) != 0) { 1101#ifdef DEBUG 1102 fprintf(stderr,"Name2IP: %s\n",gai_strerror(err)); 1103#endif 1104 return NULL; 1105 } else { 1106 if (res->ai_family != AF_INET6 || 1107 res->ai_addrlen != sizeof(struct sockaddr_in6)) 1108 return NULL; 1109 1110#ifdef DEBUG 1111 fprintf(stderr, "resolved: len=%d %s ", res->ai_addrlen, 1112 ip6addr_to_numeric(&((struct sockaddr_in6 *)res->ai_addr)->sin6_addr)); 1113#endif 1114 /* Get the first element of the address-chain */ 1115 addr = xtables_malloc(sizeof(struct in6_addr)); 1116 memcpy(addr, &((const struct sockaddr_in6 *)res->ai_addr)->sin6_addr, 1117 sizeof(struct in6_addr)); 1118 freeaddrinfo(res); 1119 *naddr = 1; 1120 return addr; 1121 } 1122 1123 return NULL; 1124} 1125 1126static struct in6_addr *network_to_ip6addr(const char *name) 1127{ 1128 /* abort();*/ 1129 /* TODO: not implemented yet, but the exception breaks the 1130 * name resolvation */ 1131 return NULL; 1132} 1133 1134static struct in6_addr * 1135ip6parse_hostnetwork(const char *name, unsigned int *naddrs) 1136{ 1137 struct in6_addr *addrp, *addrptmp; 1138 1139 if ((addrptmp = numeric_to_ip6addr(name)) != NULL || 1140 (addrptmp = network_to_ip6addr(name)) != NULL) { 1141 addrp = xtables_malloc(sizeof(struct in6_addr)); 1142 memcpy(addrp, addrptmp, sizeof(*addrp)); 1143 *naddrs = 1; 1144 return addrp; 1145 } 1146 if ((addrp = host_to_ip6addr(name, naddrs)) != NULL) 1147 return addrp; 1148 1149 exit_error(PARAMETER_PROBLEM, "host/network `%s' not found", name); 1150} 1151 1152static struct in6_addr *parse_ip6mask(char *mask) 1153{ 1154 static struct in6_addr maskaddr; 1155 struct in6_addr *addrp; 1156 unsigned int bits; 1157 1158 if (mask == NULL) { 1159 /* no mask at all defaults to 128 bits */ 1160 memset(&maskaddr, 0xff, sizeof maskaddr); 1161 return &maskaddr; 1162 } 1163 if ((addrp = numeric_to_ip6addr(mask)) != NULL) 1164 return addrp; 1165 if (string_to_number(mask, 0, 128, &bits) == -1) 1166 exit_error(PARAMETER_PROBLEM, 1167 "invalid mask `%s' specified", mask); 1168 if (bits != 0) { 1169 char *p = (void *)&maskaddr; 1170 memset(p, 0xff, bits / 8); 1171 memset(p + (bits / 8) + 1, 0, (128 - bits) / 8); 1172 p[bits/8] = 0xff << (8 - (bits & 7)); 1173 return &maskaddr; 1174 } 1175 1176 memset(&maskaddr, 0, sizeof(maskaddr)); 1177 return &maskaddr; 1178} 1179 1180void ip6parse_hostnetworkmask(const char *name, struct in6_addr **addrpp, 1181 struct in6_addr *maskp, unsigned int *naddrs) 1182{ 1183 struct in6_addr *addrp; 1184 unsigned int i, j, k, n; 1185 char buf[256], *p; 1186 1187 strncpy(buf, name, sizeof(buf) - 1); 1188 buf[sizeof(buf)-1] = '\0'; 1189 if ((p = strrchr(buf, '/')) != NULL) { 1190 *p = '\0'; 1191 addrp = parse_ip6mask(p + 1); 1192 } else { 1193 addrp = parse_ip6mask(NULL); 1194 } 1195 memcpy(maskp, addrp, sizeof(*maskp)); 1196 1197 /* if a null mask is given, the name is ignored, like in "any/0" */ 1198 if (memcmp(maskp, &in6addr_any, sizeof(in6addr_any)) == 0) 1199 strcpy(buf, "::"); 1200 1201 addrp = *addrpp = ip6parse_hostnetwork(buf, naddrs); 1202 n = *naddrs; 1203 for (i = 0, j = 0; i < n; ++i) { 1204 for (k = 0; k < 4; ++k) 1205 addrp[j].s6_addr32[k] &= maskp->s6_addr32[k]; 1206 ++j; 1207 for (k = 0; k < j - 1; ++k) 1208 if (IN6_ARE_ADDR_EQUAL(&addrp[k], &addrp[j - 1])) { 1209 --*naddrs; 1210 --j; 1211 break; 1212 } 1213 } 1214} 1215 1216void save_string(const char *value) 1217{ 1218 static const char no_quote_chars[] = "_-0123456789" 1219 "abcdefghijklmnopqrstuvwxyz" 1220 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; 1221 static const char escape_chars[] = "\"\\'"; 1222 size_t length; 1223 const char *p; 1224 1225 length = strcspn(value, no_quote_chars); 1226 if (length > 0 && value[length] == 0) { 1227 /* no quoting required */ 1228 fputs(value, stdout); 1229 putchar(' '); 1230 } else { 1231 /* there is at least one dangerous character in the 1232 value, which we have to quote. Write double quotes 1233 around the value and escape special characters with 1234 a backslash */ 1235 putchar('"'); 1236 1237 for (p = strpbrk(value, escape_chars); p != NULL; 1238 p = strpbrk(value, escape_chars)) { 1239 if (p > value) 1240 fwrite(value, 1, p - value, stdout); 1241 putchar('\\'); 1242 putchar(*p); 1243 value = p + 1; 1244 } 1245 1246 /* print the rest and finish the double quoted 1247 string */ 1248 fputs(value, stdout); 1249 printf("\" "); 1250 } 1251} 1252