xtables.c revision a96166c24eaac1c91bed4815c09e91733409d888
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#include "config.h" 19#include <ctype.h> 20#include <errno.h> 21#include <fcntl.h> 22#include <inttypes.h> 23#include <netdb.h> 24#include <stdarg.h> 25#include <stdbool.h> 26#include <stdio.h> 27#include <stdlib.h> 28#include <string.h> 29#include <unistd.h> 30#include <sys/socket.h> 31#include <sys/stat.h> 32#include <sys/statfs.h> 33#include <sys/types.h> 34#include <sys/utsname.h> 35#include <sys/wait.h> 36#include <arpa/inet.h> 37#if defined(HAVE_LINUX_MAGIC_H) 38# include <linux/magic.h> /* for PROC_SUPER_MAGIC */ 39#elif defined(HAVE_LINUX_PROC_FS_H) 40# include <linux/proc_fs.h> /* Linux 2.4 */ 41#else 42# define PROC_SUPER_MAGIC 0x9fa0 43#endif 44 45#include <xtables.h> 46#include <limits.h> /* INT_MAX in ip_tables.h/ip6_tables.h */ 47#include <linux/netfilter_ipv4/ip_tables.h> 48#include <linux/netfilter_ipv6/ip6_tables.h> 49#include <libiptc/libxtc.h> 50 51#ifndef NO_SHARED_LIBS 52#include <dlfcn.h> 53#endif 54#ifndef IPT_SO_GET_REVISION_MATCH /* Old kernel source. */ 55# define IPT_SO_GET_REVISION_MATCH (IPT_BASE_CTL + 2) 56# define IPT_SO_GET_REVISION_TARGET (IPT_BASE_CTL + 3) 57#endif 58#ifndef IP6T_SO_GET_REVISION_MATCH /* Old kernel source. */ 59# define IP6T_SO_GET_REVISION_MATCH 68 60# define IP6T_SO_GET_REVISION_TARGET 69 61#endif 62#include <getopt.h> 63#include "iptables/internal.h" 64#include "xshared.h" 65 66#define NPROTO 255 67 68#ifndef PROC_SYS_MODPROBE 69#define PROC_SYS_MODPROBE "/proc/sys/kernel/modprobe" 70#endif 71 72/* we need this for ip6?tables-restore. ip6?tables-restore.c sets line to the 73 * current line of the input file, in order to give a more precise error 74 * message. ip6?tables itself doesn't need this, so it is initialized to the 75 * magic number of -1 */ 76int line = -1; 77 78void basic_exit_err(enum xtables_exittype status, const char *msg, ...) __attribute__((noreturn, format(printf,2,3))); 79 80struct xtables_globals *xt_params = NULL; 81 82void basic_exit_err(enum xtables_exittype status, const char *msg, ...) 83{ 84 va_list args; 85 86 va_start(args, msg); 87 fprintf(stderr, "%s v%s: ", xt_params->program_name, xt_params->program_version); 88 vfprintf(stderr, msg, args); 89 va_end(args); 90 fprintf(stderr, "\n"); 91 exit(status); 92} 93 94void xtables_free_opts(int unused) 95{ 96 if (xt_params->opts != xt_params->orig_opts) { 97 free(xt_params->opts); 98 xt_params->opts = NULL; 99 } 100} 101 102struct option *xtables_merge_options(struct option *orig_opts, 103 struct option *oldopts, 104 const struct option *newopts, 105 unsigned int *option_offset) 106{ 107 unsigned int num_oold = 0, num_old = 0, num_new = 0, i; 108 struct option *merge, *mp; 109 110 if (newopts == NULL) 111 return oldopts; 112 113 for (num_oold = 0; orig_opts[num_oold].name; num_oold++) ; 114 if (oldopts != NULL) 115 for (num_old = 0; oldopts[num_old].name; num_old++) ; 116 for (num_new = 0; newopts[num_new].name; num_new++) ; 117 118 /* 119 * Since @oldopts also has @orig_opts already (and does so at the 120 * start), skip these entries. 121 */ 122 oldopts += num_oold; 123 num_old -= num_oold; 124 125 merge = malloc(sizeof(*mp) * (num_oold + num_old + num_new + 1)); 126 if (merge == NULL) 127 return NULL; 128 129 /* Let the base options -[ADI...] have precedence over everything */ 130 memcpy(merge, orig_opts, sizeof(*mp) * num_oold); 131 mp = merge + num_oold; 132 133 /* Second, the new options */ 134 xt_params->option_offset += XT_OPTION_OFFSET_SCALE; 135 *option_offset = xt_params->option_offset; 136 memcpy(mp, newopts, sizeof(*mp) * num_new); 137 138 for (i = 0; i < num_new; ++i, ++mp) 139 mp->val += *option_offset; 140 141 /* Third, the old options */ 142 memcpy(mp, oldopts, sizeof(*mp) * num_old); 143 mp += num_old; 144 xtables_free_opts(0); 145 146 /* Clear trailing entry */ 147 memset(mp, 0, sizeof(*mp)); 148 return merge; 149} 150 151static const struct xtables_afinfo afinfo_ipv4 = { 152 .kmod = "ip_tables", 153 .proc_exists = "/proc/net/ip_tables_names", 154 .libprefix = "libipt_", 155 .family = NFPROTO_IPV4, 156 .ipproto = IPPROTO_IP, 157 .so_rev_match = IPT_SO_GET_REVISION_MATCH, 158 .so_rev_target = IPT_SO_GET_REVISION_TARGET, 159}; 160 161static const struct xtables_afinfo afinfo_ipv6 = { 162 .kmod = "ip6_tables", 163 .proc_exists = "/proc/net/ip6_tables_names", 164 .libprefix = "libip6t_", 165 .family = NFPROTO_IPV6, 166 .ipproto = IPPROTO_IPV6, 167 .so_rev_match = IP6T_SO_GET_REVISION_MATCH, 168 .so_rev_target = IP6T_SO_GET_REVISION_TARGET, 169}; 170 171const struct xtables_afinfo *afinfo; 172 173/* Search path for Xtables .so files */ 174static const char *xtables_libdir; 175 176/* the path to command to load kernel module */ 177const char *xtables_modprobe_program; 178 179/* Keep track of matches/targets pending full registration: linked lists. */ 180struct xtables_match *xtables_pending_matches; 181struct xtables_target *xtables_pending_targets; 182 183/* Keep track of fully registered external matches/targets: linked lists. */ 184struct xtables_match *xtables_matches; 185struct xtables_target *xtables_targets; 186 187/* Fully register a match/target which was previously partially registered. */ 188static void xtables_fully_register_pending_match(struct xtables_match *me); 189static void xtables_fully_register_pending_target(struct xtables_target *me); 190 191void xtables_init(void) 192{ 193 xtables_libdir = getenv("XTABLES_LIBDIR"); 194 if (xtables_libdir != NULL) 195 return; 196 xtables_libdir = getenv("IPTABLES_LIB_DIR"); 197 if (xtables_libdir != NULL) { 198 fprintf(stderr, "IPTABLES_LIB_DIR is deprecated, " 199 "use XTABLES_LIBDIR.\n"); 200 return; 201 } 202 /* 203 * Well yes, IP6TABLES_LIB_DIR is of lower priority over 204 * IPTABLES_LIB_DIR since this moved to libxtables; I think that is ok 205 * for these env vars are deprecated anyhow, and in light of the 206 * (shared) libxt_*.so files, makes less sense to have 207 * IPTABLES_LIB_DIR != IP6TABLES_LIB_DIR. 208 */ 209 xtables_libdir = getenv("IP6TABLES_LIB_DIR"); 210 if (xtables_libdir != NULL) { 211 fprintf(stderr, "IP6TABLES_LIB_DIR is deprecated, " 212 "use XTABLES_LIBDIR.\n"); 213 return; 214 } 215 xtables_libdir = XTABLES_LIBDIR; 216} 217 218void xtables_set_nfproto(uint8_t nfproto) 219{ 220 switch (nfproto) { 221 case NFPROTO_IPV4: 222 afinfo = &afinfo_ipv4; 223 break; 224 case NFPROTO_IPV6: 225 afinfo = &afinfo_ipv6; 226 break; 227 default: 228 fprintf(stderr, "libxtables: unhandled NFPROTO in %s\n", 229 __func__); 230 } 231} 232 233/** 234 * xtables_set_params - set the global parameters used by xtables 235 * @xtp: input xtables_globals structure 236 * 237 * The app is expected to pass a valid xtables_globals data-filled 238 * with proper values 239 * @xtp cannot be NULL 240 * 241 * Returns -1 on failure to set and 0 on success 242 */ 243int xtables_set_params(struct xtables_globals *xtp) 244{ 245 if (!xtp) { 246 fprintf(stderr, "%s: Illegal global params\n",__func__); 247 return -1; 248 } 249 250 xt_params = xtp; 251 252 if (!xt_params->exit_err) 253 xt_params->exit_err = basic_exit_err; 254 255 return 0; 256} 257 258int xtables_init_all(struct xtables_globals *xtp, uint8_t nfproto) 259{ 260 xtables_init(); 261 xtables_set_nfproto(nfproto); 262 return xtables_set_params(xtp); 263} 264 265/** 266 * xtables_*alloc - wrappers that exit on failure 267 */ 268void *xtables_calloc(size_t count, size_t size) 269{ 270 void *p; 271 272 if ((p = calloc(count, size)) == NULL) { 273 perror("ip[6]tables: calloc failed"); 274 exit(1); 275 } 276 277 return p; 278} 279 280void *xtables_malloc(size_t size) 281{ 282 void *p; 283 284 if ((p = malloc(size)) == NULL) { 285 perror("ip[6]tables: malloc failed"); 286 exit(1); 287 } 288 289 return p; 290} 291 292void *xtables_realloc(void *ptr, size_t size) 293{ 294 void *p; 295 296 if ((p = realloc(ptr, size)) == NULL) { 297 perror("ip[6]tables: realloc failed"); 298 exit(1); 299 } 300 301 return p; 302} 303 304static char *get_modprobe(void) 305{ 306 int procfile; 307 char *ret; 308 309#define PROCFILE_BUFSIZ 1024 310 procfile = open(PROC_SYS_MODPROBE, O_RDONLY); 311 if (procfile < 0) 312 return NULL; 313 if (fcntl(procfile, F_SETFD, FD_CLOEXEC) == -1) { 314 fprintf(stderr, "Could not set close on exec: %s\n", 315 strerror(errno)); 316 exit(1); 317 } 318 319 ret = malloc(PROCFILE_BUFSIZ); 320 if (ret) { 321 memset(ret, 0, PROCFILE_BUFSIZ); 322 switch (read(procfile, ret, PROCFILE_BUFSIZ)) { 323 case -1: goto fail; 324 case PROCFILE_BUFSIZ: goto fail; /* Partial read. Wierd */ 325 } 326 if (ret[strlen(ret)-1]=='\n') 327 ret[strlen(ret)-1]=0; 328 close(procfile); 329 return ret; 330 } 331 fail: 332 free(ret); 333 close(procfile); 334 return NULL; 335} 336 337int xtables_insmod(const char *modname, const char *modprobe, bool quiet) 338{ 339 char *buf = NULL; 340 char *argv[4]; 341 int status; 342 343 /* If they don't explicitly set it, read out of kernel */ 344 if (!modprobe) { 345 buf = get_modprobe(); 346 if (!buf) 347 return -1; 348 modprobe = buf; 349 } 350 351 /* 352 * Need to flush the buffer, or the child may output it again 353 * when switching the program thru execv. 354 */ 355 fflush(stdout); 356 357 switch (vfork()) { 358 case 0: 359 argv[0] = (char *)modprobe; 360 argv[1] = (char *)modname; 361 if (quiet) { 362 argv[2] = "-q"; 363 argv[3] = NULL; 364 } else { 365 argv[2] = NULL; 366 argv[3] = NULL; 367 } 368 execv(argv[0], argv); 369 370 /* not usually reached */ 371 exit(1); 372 case -1: 373 free(buf); 374 return -1; 375 376 default: /* parent */ 377 wait(&status); 378 } 379 380 free(buf); 381 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) 382 return 0; 383 return -1; 384} 385 386/* return true if a given file exists within procfs */ 387static bool proc_file_exists(const char *filename) 388{ 389 struct stat s; 390 struct statfs f; 391 392 if (lstat(filename, &s)) 393 return false; 394 if (!S_ISREG(s.st_mode)) 395 return false; 396 if (statfs(filename, &f)) 397 return false; 398 if (f.f_type != PROC_SUPER_MAGIC) 399 return false; 400 return true; 401} 402 403int xtables_load_ko(const char *modprobe, bool quiet) 404{ 405 static bool loaded = false; 406 int ret; 407 408 if (loaded) 409 return 0; 410 411 if (proc_file_exists(afinfo->proc_exists)) { 412 loaded = true; 413 return 0; 414 }; 415 416 ret = xtables_insmod(afinfo->kmod, modprobe, quiet); 417 if (ret == 0) 418 loaded = true; 419 420 return ret; 421} 422 423/** 424 * xtables_strtou{i,l} - string to number conversion 425 * @s: input string 426 * @end: like strtoul's "end" pointer 427 * @value: pointer for result 428 * @min: minimum accepted value 429 * @max: maximum accepted value 430 * 431 * If @end is NULL, we assume the caller wants a "strict strtoul", and hence 432 * "15a" is rejected. 433 * In either case, the value obtained is compared for min-max compliance. 434 * Base is always 0, i.e. autodetect depending on @s. 435 * 436 * Returns true/false whether number was accepted. On failure, *value has 437 * undefined contents. 438 */ 439bool xtables_strtoul(const char *s, char **end, uintmax_t *value, 440 uintmax_t min, uintmax_t max) 441{ 442 uintmax_t v; 443 const char *p; 444 char *my_end; 445 446 errno = 0; 447 /* Since strtoul allows leading minus, we have to check for ourself. */ 448 for (p = s; isspace(*p); ++p) 449 ; 450 if (*p == '-') 451 return false; 452 v = strtoumax(s, &my_end, 0); 453 if (my_end == s) 454 return false; 455 if (end != NULL) 456 *end = my_end; 457 458 if (errno != ERANGE && min <= v && (max == 0 || v <= max)) { 459 if (value != NULL) 460 *value = v; 461 if (end == NULL) 462 return *my_end == '\0'; 463 return true; 464 } 465 466 return false; 467} 468 469bool xtables_strtoui(const char *s, char **end, unsigned int *value, 470 unsigned int min, unsigned int max) 471{ 472 uintmax_t v; 473 bool ret; 474 475 ret = xtables_strtoul(s, end, &v, min, max); 476 if (value != NULL) 477 *value = v; 478 return ret; 479} 480 481int xtables_service_to_port(const char *name, const char *proto) 482{ 483 struct servent *service; 484 485 if ((service = getservbyname(name, proto)) != NULL) 486 return ntohs((unsigned short) service->s_port); 487 488 return -1; 489} 490 491uint16_t xtables_parse_port(const char *port, const char *proto) 492{ 493 unsigned int portnum; 494 495 if (xtables_strtoui(port, NULL, &portnum, 0, UINT16_MAX) || 496 (portnum = xtables_service_to_port(port, proto)) != (unsigned)-1) 497 return portnum; 498 499 xt_params->exit_err(PARAMETER_PROBLEM, 500 "invalid port/service `%s' specified", port); 501} 502 503void xtables_parse_interface(const char *arg, char *vianame, 504 unsigned char *mask) 505{ 506 unsigned int vialen = strlen(arg); 507 unsigned int i; 508 509 memset(mask, 0, IFNAMSIZ); 510 memset(vianame, 0, IFNAMSIZ); 511 512 if (vialen + 1 > IFNAMSIZ) 513 xt_params->exit_err(PARAMETER_PROBLEM, 514 "interface name `%s' must be shorter than IFNAMSIZ" 515 " (%i)", arg, IFNAMSIZ-1); 516 517 strcpy(vianame, arg); 518 if (vialen == 0) 519 return; 520 else if (vianame[vialen - 1] == '+') { 521 memset(mask, 0xFF, vialen - 1); 522 /* Don't remove `+' here! -HW */ 523 } else { 524 /* Include nul-terminator in match */ 525 memset(mask, 0xFF, vialen + 1); 526 for (i = 0; vianame[i]; i++) { 527 if (vianame[i] == '/' || 528 vianame[i] == ' ') { 529 fprintf(stderr, 530 "Warning: weird character in interface" 531 " `%s' ('/' and ' ' are not allowed by the kernel).\n", 532 vianame); 533 break; 534 } 535 } 536 } 537} 538 539#ifndef NO_SHARED_LIBS 540static void *load_extension(const char *search_path, const char *af_prefix, 541 const char *name, bool is_target) 542{ 543 const char *all_prefixes[] = {"libxt_", af_prefix, NULL}; 544 const char **prefix; 545 const char *dir = search_path, *next; 546 void *ptr = NULL; 547 struct stat sb; 548 char path[256]; 549 550 do { 551 next = strchr(dir, ':'); 552 if (next == NULL) 553 next = dir + strlen(dir); 554 555 for (prefix = all_prefixes; *prefix != NULL; ++prefix) { 556 snprintf(path, sizeof(path), "%.*s/%s%s.so", 557 (unsigned int)(next - dir), dir, 558 *prefix, name); 559 560 if (stat(path, &sb) != 0) { 561 if (errno == ENOENT) 562 continue; 563 fprintf(stderr, "%s: %s\n", path, 564 strerror(errno)); 565 return NULL; 566 } 567 if (dlopen(path, RTLD_NOW) == NULL) { 568 fprintf(stderr, "%s: %s\n", path, dlerror()); 569 break; 570 } 571 572 if (is_target) 573 ptr = xtables_find_target(name, XTF_DONT_LOAD); 574 else 575 ptr = xtables_find_match(name, 576 XTF_DONT_LOAD, NULL); 577 578 if (ptr != NULL) 579 return ptr; 580 581 fprintf(stderr, "%s: no \"%s\" extension found for " 582 "this protocol\n", path, name); 583 errno = ENOENT; 584 return NULL; 585 } 586 dir = next + 1; 587 } while (*next != '\0'); 588 589 return NULL; 590} 591#endif 592 593struct xtables_match * 594xtables_find_match(const char *name, enum xtables_tryload tryload, 595 struct xtables_rule_match **matches) 596{ 597 struct xtables_match **dptr; 598 struct xtables_match *ptr; 599 const char *icmp6 = "icmp6"; 600 601 if (strlen(name) >= XT_EXTENSION_MAXNAMELEN) 602 xtables_error(PARAMETER_PROBLEM, 603 "Invalid match name \"%s\" (%u chars max)", 604 name, XT_EXTENSION_MAXNAMELEN - 1); 605 606 /* This is ugly as hell. Nonetheless, there is no way of changing 607 * this without hurting backwards compatibility */ 608 if ( (strcmp(name,"icmpv6") == 0) || 609 (strcmp(name,"ipv6-icmp") == 0) || 610 (strcmp(name,"icmp6") == 0) ) 611 name = icmp6; 612 613 /* Trigger delayed initialization */ 614 for (dptr = &xtables_pending_matches; *dptr; ) { 615 if (strcmp(name, (*dptr)->name) == 0) { 616 ptr = *dptr; 617 *dptr = (*dptr)->next; 618 ptr->next = NULL; 619 xtables_fully_register_pending_match(ptr); 620 } else { 621 dptr = &((*dptr)->next); 622 } 623 } 624 625 for (ptr = xtables_matches; ptr; ptr = ptr->next) { 626 if (strcmp(name, ptr->name) == 0) { 627 struct xtables_match *clone; 628 629 /* First match of this type: */ 630 if (ptr->m == NULL) 631 break; 632 633 /* Second and subsequent clones */ 634 clone = xtables_malloc(sizeof(struct xtables_match)); 635 memcpy(clone, ptr, sizeof(struct xtables_match)); 636 clone->udata = NULL; 637 clone->mflags = 0; 638 /* This is a clone: */ 639 clone->next = clone; 640 641 ptr = clone; 642 break; 643 } 644 } 645 646#ifndef NO_SHARED_LIBS 647 if (!ptr && tryload != XTF_DONT_LOAD && tryload != XTF_DURING_LOAD) { 648 ptr = load_extension(xtables_libdir, afinfo->libprefix, 649 name, false); 650 651 if (ptr == NULL && tryload == XTF_LOAD_MUST_SUCCEED) 652 xt_params->exit_err(PARAMETER_PROBLEM, 653 "Couldn't load match `%s':%s\n", 654 name, strerror(errno)); 655 } 656#else 657 if (ptr && !ptr->loaded) { 658 if (tryload != XTF_DONT_LOAD) 659 ptr->loaded = 1; 660 else 661 ptr = NULL; 662 } 663 if(!ptr && (tryload == XTF_LOAD_MUST_SUCCEED)) { 664 xt_params->exit_err(PARAMETER_PROBLEM, 665 "Couldn't find match `%s'\n", name); 666 } 667#endif 668 669 if (ptr && matches) { 670 struct xtables_rule_match **i; 671 struct xtables_rule_match *newentry; 672 673 newentry = xtables_malloc(sizeof(struct xtables_rule_match)); 674 675 for (i = matches; *i; i = &(*i)->next) { 676 if (strcmp(name, (*i)->match->name) == 0) 677 (*i)->completed = true; 678 } 679 newentry->match = ptr; 680 newentry->completed = false; 681 newentry->next = NULL; 682 *i = newentry; 683 } 684 685 return ptr; 686} 687 688struct xtables_target * 689xtables_find_target(const char *name, enum xtables_tryload tryload) 690{ 691 struct xtables_target **dptr; 692 struct xtables_target *ptr; 693 694 /* Standard target? */ 695 if (strcmp(name, "") == 0 696 || strcmp(name, XTC_LABEL_ACCEPT) == 0 697 || strcmp(name, XTC_LABEL_DROP) == 0 698 || strcmp(name, XTC_LABEL_QUEUE) == 0 699 || strcmp(name, XTC_LABEL_RETURN) == 0) 700 name = "standard"; 701 702 /* Trigger delayed initialization */ 703 for (dptr = &xtables_pending_targets; *dptr; ) { 704 if (strcmp(name, (*dptr)->name) == 0) { 705 ptr = *dptr; 706 *dptr = (*dptr)->next; 707 ptr->next = NULL; 708 xtables_fully_register_pending_target(ptr); 709 } else { 710 dptr = &((*dptr)->next); 711 } 712 } 713 714 for (ptr = xtables_targets; ptr; ptr = ptr->next) { 715 if (strcmp(name, ptr->name) == 0) 716 break; 717 } 718 719#ifndef NO_SHARED_LIBS 720 if (!ptr && tryload != XTF_DONT_LOAD && tryload != XTF_DURING_LOAD) { 721 ptr = load_extension(xtables_libdir, afinfo->libprefix, 722 name, true); 723 724 if (ptr == NULL && tryload == XTF_LOAD_MUST_SUCCEED) 725 xt_params->exit_err(PARAMETER_PROBLEM, 726 "Couldn't load target `%s':%s\n", 727 name, strerror(errno)); 728 } 729#else 730 if (ptr && !ptr->loaded) { 731 if (tryload != XTF_DONT_LOAD) 732 ptr->loaded = 1; 733 else 734 ptr = NULL; 735 } 736 if (ptr == NULL && tryload == XTF_LOAD_MUST_SUCCEED) { 737 xt_params->exit_err(PARAMETER_PROBLEM, 738 "Couldn't find target `%s'\n", name); 739 } 740#endif 741 742 if (ptr) 743 ptr->used = 1; 744 745 return ptr; 746} 747 748static int compatible_revision(const char *name, uint8_t revision, int opt) 749{ 750 struct xt_get_revision rev; 751 socklen_t s = sizeof(rev); 752 int max_rev, sockfd; 753 754 sockfd = socket(afinfo->family, SOCK_RAW, IPPROTO_RAW); 755 if (sockfd < 0) { 756 if (errno == EPERM) { 757 /* revision 0 is always supported. */ 758 if (revision != 0) 759 fprintf(stderr, "%s: Could not determine whether " 760 "revision %u is supported, " 761 "assuming it is.\n", 762 name, revision); 763 return 1; 764 } 765 fprintf(stderr, "Could not open socket to kernel: %s\n", 766 strerror(errno)); 767 exit(1); 768 } 769 770 if (fcntl(sockfd, F_SETFD, FD_CLOEXEC) == -1) { 771 fprintf(stderr, "Could not set close on exec: %s\n", 772 strerror(errno)); 773 exit(1); 774 } 775 776 xtables_load_ko(xtables_modprobe_program, true); 777 778 strcpy(rev.name, name); 779 rev.revision = revision; 780 781 max_rev = getsockopt(sockfd, afinfo->ipproto, opt, &rev, &s); 782 if (max_rev < 0) { 783 /* Definitely don't support this? */ 784 if (errno == ENOENT || errno == EPROTONOSUPPORT) { 785 close(sockfd); 786 return 0; 787 } else if (errno == ENOPROTOOPT) { 788 close(sockfd); 789 /* Assume only revision 0 support (old kernel) */ 790 return (revision == 0); 791 } else { 792 fprintf(stderr, "getsockopt failed strangely: %s\n", 793 strerror(errno)); 794 exit(1); 795 } 796 } 797 close(sockfd); 798 return 1; 799} 800 801 802static int compatible_match_revision(const char *name, uint8_t revision) 803{ 804 return compatible_revision(name, revision, afinfo->so_rev_match); 805} 806 807static int compatible_target_revision(const char *name, uint8_t revision) 808{ 809 return compatible_revision(name, revision, afinfo->so_rev_target); 810} 811 812static void xtables_check_options(const char *name, const struct option *opt) 813{ 814 for (; opt->name != NULL; ++opt) 815 if (opt->val < 0 || opt->val >= XT_OPTION_OFFSET_SCALE) { 816 fprintf(stderr, "%s: Extension %s uses invalid " 817 "option value %d\n",xt_params->program_name, 818 name, opt->val); 819 exit(1); 820 } 821} 822 823void xtables_register_match(struct xtables_match *me) 824{ 825 if (me->version == NULL) { 826 fprintf(stderr, "%s: match %s<%u> is missing a version\n", 827 xt_params->program_name, me->name, me->revision); 828 exit(1); 829 } 830 if (strcmp(me->version, XTABLES_VERSION) != 0) { 831 fprintf(stderr, "%s: match \"%s\" has version \"%s\", " 832 "but \"%s\" is required.\n", 833 xt_params->program_name, me->name, 834 me->version, XTABLES_VERSION); 835 exit(1); 836 } 837 838 if (strlen(me->name) >= XT_EXTENSION_MAXNAMELEN) { 839 fprintf(stderr, "%s: match `%s' has invalid name\n", 840 xt_params->program_name, me->name); 841 exit(1); 842 } 843 844 if (me->family >= NPROTO) { 845 fprintf(stderr, 846 "%s: BUG: match %s has invalid protocol family\n", 847 xt_params->program_name, me->name); 848 exit(1); 849 } 850 851 if (me->x6_options != NULL) 852 xtables_option_metavalidate(me->name, me->x6_options); 853 if (me->extra_opts != NULL) 854 xtables_check_options(me->name, me->extra_opts); 855 856 /* ignore not interested match */ 857 if (me->family != afinfo->family && me->family != AF_UNSPEC) 858 return; 859 860 /* place on linked list of matches pending full registration */ 861 me->next = xtables_pending_matches; 862 xtables_pending_matches = me; 863} 864 865static void xtables_fully_register_pending_match(struct xtables_match *me) 866{ 867 struct xtables_match **i, *old; 868 869 old = xtables_find_match(me->name, XTF_DURING_LOAD, NULL); 870 if (old) { 871 if (old->revision == me->revision && 872 old->family == me->family) { 873 fprintf(stderr, 874 "%s: match `%s' already registered.\n", 875 xt_params->program_name, me->name); 876 exit(1); 877 } 878 879 /* Now we have two (or more) options, check compatibility. */ 880 if (compatible_match_revision(old->name, old->revision) 881 && old->revision > me->revision) 882 return; 883 884 /* See if new match can be used. */ 885 if (!compatible_match_revision(me->name, me->revision)) 886 return; 887 888 /* Prefer !AF_UNSPEC over AF_UNSPEC for same revision. */ 889 if (old->revision == me->revision && me->family == AF_UNSPEC) 890 return; 891 892 /* Delete old one. */ 893 for (i = &xtables_matches; *i!=old; i = &(*i)->next); 894 *i = old->next; 895 } 896 897 if (me->size != XT_ALIGN(me->size)) { 898 fprintf(stderr, "%s: match `%s' has invalid size %u.\n", 899 xt_params->program_name, me->name, 900 (unsigned int)me->size); 901 exit(1); 902 } 903 904 /* Append to list. */ 905 for (i = &xtables_matches; *i; i = &(*i)->next); 906 me->next = NULL; 907 *i = me; 908 909 me->m = NULL; 910 me->mflags = 0; 911} 912 913void xtables_register_matches(struct xtables_match *match, unsigned int n) 914{ 915 do { 916 xtables_register_match(&match[--n]); 917 } while (n > 0); 918} 919 920void xtables_register_target(struct xtables_target *me) 921{ 922 if (me->version == NULL) { 923 fprintf(stderr, "%s: target %s<%u> is missing a version\n", 924 xt_params->program_name, me->name, me->revision); 925 exit(1); 926 } 927 if (strcmp(me->version, XTABLES_VERSION) != 0) { 928 fprintf(stderr, "%s: target \"%s\" has version \"%s\", " 929 "but \"%s\" is required.\n", 930 xt_params->program_name, me->name, 931 me->version, XTABLES_VERSION); 932 exit(1); 933 } 934 935 if (strlen(me->name) >= XT_EXTENSION_MAXNAMELEN) { 936 fprintf(stderr, "%s: target `%s' has invalid name\n", 937 xt_params->program_name, me->name); 938 exit(1); 939 } 940 941 if (me->family >= NPROTO) { 942 fprintf(stderr, 943 "%s: BUG: target %s has invalid protocol family\n", 944 xt_params->program_name, me->name); 945 exit(1); 946 } 947 948 if (me->x6_options != NULL) 949 xtables_option_metavalidate(me->name, me->x6_options); 950 if (me->extra_opts != NULL) 951 xtables_check_options(me->name, me->extra_opts); 952 953 /* ignore not interested target */ 954 if (me->family != afinfo->family && me->family != AF_UNSPEC) 955 return; 956 957 /* place on linked list of targets pending full registration */ 958 me->next = xtables_pending_targets; 959 xtables_pending_targets = me; 960} 961 962static void xtables_fully_register_pending_target(struct xtables_target *me) 963{ 964 struct xtables_target *old; 965 966 old = xtables_find_target(me->name, XTF_DURING_LOAD); 967 if (old) { 968 struct xtables_target **i; 969 970 if (old->revision == me->revision && 971 old->family == me->family) { 972 fprintf(stderr, 973 "%s: target `%s' already registered.\n", 974 xt_params->program_name, me->name); 975 exit(1); 976 } 977 978 /* Now we have two (or more) options, check compatibility. */ 979 if (compatible_target_revision(old->name, old->revision) 980 && old->revision > me->revision) 981 return; 982 983 /* See if new target can be used. */ 984 if (!compatible_target_revision(me->name, me->revision)) 985 return; 986 987 /* Prefer !AF_UNSPEC over AF_UNSPEC for same revision. */ 988 if (old->revision == me->revision && me->family == AF_UNSPEC) 989 return; 990 991 /* Delete old one. */ 992 for (i = &xtables_targets; *i!=old; i = &(*i)->next); 993 *i = old->next; 994 } 995 996 if (me->size != XT_ALIGN(me->size)) { 997 fprintf(stderr, "%s: target `%s' has invalid size %u.\n", 998 xt_params->program_name, me->name, 999 (unsigned int)me->size); 1000 exit(1); 1001 } 1002 1003 /* Prepend to list. */ 1004 me->next = xtables_targets; 1005 xtables_targets = me; 1006 me->t = NULL; 1007 me->tflags = 0; 1008} 1009 1010void xtables_register_targets(struct xtables_target *target, unsigned int n) 1011{ 1012 do { 1013 xtables_register_target(&target[--n]); 1014 } while (n > 0); 1015} 1016 1017/** 1018 * xtables_param_act - act on condition 1019 * @status: a constant from enum xtables_exittype 1020 * 1021 * %XTF_ONLY_ONCE: print error message that option may only be used once. 1022 * @p1: module name (e.g. "mark") 1023 * @p2(...): option in conflict (e.g. "--mark") 1024 * @p3(...): condition to match on (see extensions/ for examples) 1025 * 1026 * %XTF_NO_INVERT: option does not support inversion 1027 * @p1: module name 1028 * @p2: option in conflict 1029 * @p3: condition to match on 1030 * 1031 * %XTF_BAD_VALUE: bad value for option 1032 * @p1: module name 1033 * @p2: option with which the problem occured (e.g. "--mark") 1034 * @p3: string the user passed in (e.g. "99999999999999") 1035 * 1036 * %XTF_ONE_ACTION: two mutually exclusive actions have been specified 1037 * @p1: module name 1038 * 1039 * Displays an error message and exits the program. 1040 */ 1041void xtables_param_act(unsigned int status, const char *p1, ...) 1042{ 1043 const char *p2, *p3; 1044 va_list args; 1045 bool b; 1046 1047 va_start(args, p1); 1048 1049 switch (status) { 1050 case XTF_ONLY_ONCE: 1051 p2 = va_arg(args, const char *); 1052 b = va_arg(args, unsigned int); 1053 if (!b) { 1054 va_end(args); 1055 return; 1056 } 1057 xt_params->exit_err(PARAMETER_PROBLEM, 1058 "%s: \"%s\" option may only be specified once", 1059 p1, p2); 1060 break; 1061 case XTF_NO_INVERT: 1062 p2 = va_arg(args, const char *); 1063 b = va_arg(args, unsigned int); 1064 if (!b) { 1065 va_end(args); 1066 return; 1067 } 1068 xt_params->exit_err(PARAMETER_PROBLEM, 1069 "%s: \"%s\" option cannot be inverted", p1, p2); 1070 break; 1071 case XTF_BAD_VALUE: 1072 p2 = va_arg(args, const char *); 1073 p3 = va_arg(args, const char *); 1074 xt_params->exit_err(PARAMETER_PROBLEM, 1075 "%s: Bad value for \"%s\" option: \"%s\"", 1076 p1, p2, p3); 1077 break; 1078 case XTF_ONE_ACTION: 1079 b = va_arg(args, unsigned int); 1080 if (!b) { 1081 va_end(args); 1082 return; 1083 } 1084 xt_params->exit_err(PARAMETER_PROBLEM, 1085 "%s: At most one action is possible", p1); 1086 break; 1087 default: 1088 xt_params->exit_err(status, p1, args); 1089 break; 1090 } 1091 1092 va_end(args); 1093} 1094 1095const char *xtables_ipaddr_to_numeric(const struct in_addr *addrp) 1096{ 1097 static char buf[20]; 1098 const unsigned char *bytep = (const void *)&addrp->s_addr; 1099 1100 sprintf(buf, "%u.%u.%u.%u", bytep[0], bytep[1], bytep[2], bytep[3]); 1101 return buf; 1102} 1103 1104static const char *ipaddr_to_host(const struct in_addr *addr) 1105{ 1106 struct hostent *host; 1107 1108 host = gethostbyaddr(addr, sizeof(struct in_addr), AF_INET); 1109 if (host == NULL) 1110 return NULL; 1111 1112 return host->h_name; 1113} 1114 1115static const char *ipaddr_to_network(const struct in_addr *addr) 1116{ 1117 struct netent *net; 1118 1119 if ((net = getnetbyaddr(ntohl(addr->s_addr), AF_INET)) != NULL) 1120 return net->n_name; 1121 1122 return NULL; 1123} 1124 1125const char *xtables_ipaddr_to_anyname(const struct in_addr *addr) 1126{ 1127 const char *name; 1128 1129 if ((name = ipaddr_to_host(addr)) != NULL || 1130 (name = ipaddr_to_network(addr)) != NULL) 1131 return name; 1132 1133 return xtables_ipaddr_to_numeric(addr); 1134} 1135 1136int xtables_ipmask_to_cidr(const struct in_addr *mask) 1137{ 1138 uint32_t maskaddr, bits; 1139 int i; 1140 1141 maskaddr = ntohl(mask->s_addr); 1142 /* shortcut for /32 networks */ 1143 if (maskaddr == 0xFFFFFFFFL) 1144 return 32; 1145 1146 i = 32; 1147 bits = 0xFFFFFFFEL; 1148 while (--i >= 0 && maskaddr != bits) 1149 bits <<= 1; 1150 if (i >= 0) 1151 return i; 1152 1153 /* this mask cannot be converted to CIDR notation */ 1154 return -1; 1155} 1156 1157const char *xtables_ipmask_to_numeric(const struct in_addr *mask) 1158{ 1159 static char buf[20]; 1160 uint32_t cidr; 1161 1162 cidr = xtables_ipmask_to_cidr(mask); 1163 if (cidr < 0) { 1164 /* mask was not a decent combination of 1's and 0's */ 1165 sprintf(buf, "/%s", xtables_ipaddr_to_numeric(mask)); 1166 return buf; 1167 } else if (cidr == 32) { 1168 /* we don't want to see "/32" */ 1169 return ""; 1170 } 1171 1172 sprintf(buf, "/%d", cidr); 1173 return buf; 1174} 1175 1176static struct in_addr *__numeric_to_ipaddr(const char *dotted, bool is_mask) 1177{ 1178 static struct in_addr addr; 1179 unsigned char *addrp; 1180 unsigned int onebyte; 1181 char buf[20], *p, *q; 1182 int i; 1183 1184 /* copy dotted string, because we need to modify it */ 1185 strncpy(buf, dotted, sizeof(buf) - 1); 1186 buf[sizeof(buf) - 1] = '\0'; 1187 addrp = (void *)&addr.s_addr; 1188 1189 p = buf; 1190 for (i = 0; i < 3; ++i) { 1191 if ((q = strchr(p, '.')) == NULL) { 1192 if (is_mask) 1193 return NULL; 1194 1195 /* autocomplete, this is a network address */ 1196 if (!xtables_strtoui(p, NULL, &onebyte, 0, UINT8_MAX)) 1197 return NULL; 1198 1199 addrp[i] = onebyte; 1200 while (i < 3) 1201 addrp[++i] = 0; 1202 1203 return &addr; 1204 } 1205 1206 *q = '\0'; 1207 if (!xtables_strtoui(p, NULL, &onebyte, 0, UINT8_MAX)) 1208 return NULL; 1209 1210 addrp[i] = onebyte; 1211 p = q + 1; 1212 } 1213 1214 /* we have checked 3 bytes, now we check the last one */ 1215 if (!xtables_strtoui(p, NULL, &onebyte, 0, UINT8_MAX)) 1216 return NULL; 1217 1218 addrp[3] = onebyte; 1219 return &addr; 1220} 1221 1222struct in_addr *xtables_numeric_to_ipaddr(const char *dotted) 1223{ 1224 return __numeric_to_ipaddr(dotted, false); 1225} 1226 1227struct in_addr *xtables_numeric_to_ipmask(const char *dotted) 1228{ 1229 return __numeric_to_ipaddr(dotted, true); 1230} 1231 1232static struct in_addr *network_to_ipaddr(const char *name) 1233{ 1234 static struct in_addr addr; 1235 struct netent *net; 1236 1237 if ((net = getnetbyname(name)) != NULL) { 1238 if (net->n_addrtype != AF_INET) 1239 return NULL; 1240 addr.s_addr = htonl(net->n_net); 1241 return &addr; 1242 } 1243 1244 return NULL; 1245} 1246 1247static struct in_addr *host_to_ipaddr(const char *name, unsigned int *naddr) 1248{ 1249 struct hostent *host; 1250 struct in_addr *addr; 1251 unsigned int i; 1252 1253 *naddr = 0; 1254 if ((host = gethostbyname(name)) != NULL) { 1255 if (host->h_addrtype != AF_INET || 1256 host->h_length != sizeof(struct in_addr)) 1257 return NULL; 1258 1259 while (host->h_addr_list[*naddr] != NULL) 1260 ++*naddr; 1261 addr = xtables_calloc(*naddr, sizeof(struct in_addr)); 1262 for (i = 0; i < *naddr; i++) 1263 memcpy(&addr[i], host->h_addr_list[i], 1264 sizeof(struct in_addr)); 1265 return addr; 1266 } 1267 1268 return NULL; 1269} 1270 1271static struct in_addr * 1272ipparse_hostnetwork(const char *name, unsigned int *naddrs) 1273{ 1274 struct in_addr *addrptmp, *addrp; 1275 1276 if ((addrptmp = xtables_numeric_to_ipaddr(name)) != NULL || 1277 (addrptmp = network_to_ipaddr(name)) != NULL) { 1278 addrp = xtables_malloc(sizeof(struct in_addr)); 1279 memcpy(addrp, addrptmp, sizeof(*addrp)); 1280 *naddrs = 1; 1281 return addrp; 1282 } 1283 if ((addrptmp = host_to_ipaddr(name, naddrs)) != NULL) 1284 return addrptmp; 1285 1286 xt_params->exit_err(PARAMETER_PROBLEM, "host/network `%s' not found", name); 1287} 1288 1289static struct in_addr *parse_ipmask(const char *mask) 1290{ 1291 static struct in_addr maskaddr; 1292 struct in_addr *addrp; 1293 unsigned int bits; 1294 1295 if (mask == NULL) { 1296 /* no mask at all defaults to 32 bits */ 1297 maskaddr.s_addr = 0xFFFFFFFF; 1298 return &maskaddr; 1299 } 1300 if ((addrp = xtables_numeric_to_ipmask(mask)) != NULL) 1301 /* dotted_to_addr already returns a network byte order addr */ 1302 return addrp; 1303 if (!xtables_strtoui(mask, NULL, &bits, 0, 32)) 1304 xt_params->exit_err(PARAMETER_PROBLEM, 1305 "invalid mask `%s' specified", mask); 1306 if (bits != 0) { 1307 maskaddr.s_addr = htonl(0xFFFFFFFF << (32 - bits)); 1308 return &maskaddr; 1309 } 1310 1311 maskaddr.s_addr = 0U; 1312 return &maskaddr; 1313} 1314 1315void xtables_ipparse_multiple(const char *name, struct in_addr **addrpp, 1316 struct in_addr **maskpp, unsigned int *naddrs) 1317{ 1318 struct in_addr *addrp; 1319 char buf[256], *p, *next; 1320 unsigned int len, i, j, n, count = 1; 1321 const char *loop = name; 1322 1323 while ((loop = strchr(loop, ',')) != NULL) { 1324 ++count; 1325 ++loop; /* skip ',' */ 1326 } 1327 1328 *addrpp = xtables_malloc(sizeof(struct in_addr) * count); 1329 *maskpp = xtables_malloc(sizeof(struct in_addr) * count); 1330 1331 loop = name; 1332 1333 for (i = 0; i < count; ++i) { 1334 while (isspace(*loop)) 1335 ++loop; 1336 next = strchr(loop, ','); 1337 if (next != NULL) 1338 len = next - loop; 1339 else 1340 len = strlen(loop); 1341 if (len > sizeof(buf) - 1) 1342 xt_params->exit_err(PARAMETER_PROBLEM, 1343 "Hostname too long"); 1344 1345 strncpy(buf, loop, len); 1346 buf[len] = '\0'; 1347 if ((p = strrchr(buf, '/')) != NULL) { 1348 *p = '\0'; 1349 addrp = parse_ipmask(p + 1); 1350 } else { 1351 addrp = parse_ipmask(NULL); 1352 } 1353 memcpy(*maskpp + i, addrp, sizeof(*addrp)); 1354 1355 /* if a null mask is given, the name is ignored, like in "any/0" */ 1356 if ((*maskpp + i)->s_addr == 0) 1357 /* 1358 * A bit pointless to process multiple addresses 1359 * in this case... 1360 */ 1361 strcpy(buf, "0.0.0.0"); 1362 1363 addrp = ipparse_hostnetwork(buf, &n); 1364 if (n > 1) { 1365 count += n - 1; 1366 *addrpp = xtables_realloc(*addrpp, 1367 sizeof(struct in_addr) * count); 1368 *maskpp = xtables_realloc(*maskpp, 1369 sizeof(struct in_addr) * count); 1370 for (j = 0; j < n; ++j) 1371 /* for each new addr */ 1372 memcpy(*addrpp + i + j, addrp + j, 1373 sizeof(*addrp)); 1374 for (j = 1; j < n; ++j) 1375 /* for each new mask */ 1376 memcpy(*maskpp + i + j, *maskpp + i, 1377 sizeof(*addrp)); 1378 i += n - 1; 1379 } else { 1380 memcpy(*addrpp + i, addrp, sizeof(*addrp)); 1381 } 1382 /* free what ipparse_hostnetwork had allocated: */ 1383 free(addrp); 1384 if (next == NULL) 1385 break; 1386 loop = next + 1; 1387 } 1388 *naddrs = count; 1389 for (i = 0; i < count; ++i) 1390 (*addrpp+i)->s_addr &= (*maskpp+i)->s_addr; 1391} 1392 1393 1394/** 1395 * xtables_ipparse_any - transform arbitrary name to in_addr 1396 * 1397 * Possible inputs (pseudo regex): 1398 * m{^($hostname|$networkname|$ipaddr)(/$mask)?} 1399 * "1.2.3.4/5", "1.2.3.4", "hostname", "networkname" 1400 */ 1401void xtables_ipparse_any(const char *name, struct in_addr **addrpp, 1402 struct in_addr *maskp, unsigned int *naddrs) 1403{ 1404 unsigned int i, j, k, n; 1405 struct in_addr *addrp; 1406 char buf[256], *p; 1407 1408 strncpy(buf, name, sizeof(buf) - 1); 1409 buf[sizeof(buf) - 1] = '\0'; 1410 if ((p = strrchr(buf, '/')) != NULL) { 1411 *p = '\0'; 1412 addrp = parse_ipmask(p + 1); 1413 } else { 1414 addrp = parse_ipmask(NULL); 1415 } 1416 memcpy(maskp, addrp, sizeof(*maskp)); 1417 1418 /* if a null mask is given, the name is ignored, like in "any/0" */ 1419 if (maskp->s_addr == 0U) 1420 strcpy(buf, "0.0.0.0"); 1421 1422 addrp = *addrpp = ipparse_hostnetwork(buf, naddrs); 1423 n = *naddrs; 1424 for (i = 0, j = 0; i < n; ++i) { 1425 addrp[j++].s_addr &= maskp->s_addr; 1426 for (k = 0; k < j - 1; ++k) 1427 if (addrp[k].s_addr == addrp[j-1].s_addr) { 1428 /* 1429 * Nuke the dup by copying an address from the 1430 * tail here, and check the current position 1431 * again (--j). 1432 */ 1433 memcpy(&addrp[--j], &addrp[--*naddrs], 1434 sizeof(struct in_addr)); 1435 break; 1436 } 1437 } 1438} 1439 1440const char *xtables_ip6addr_to_numeric(const struct in6_addr *addrp) 1441{ 1442 /* 0000:0000:0000:0000:0000:0000:000.000.000.000 1443 * 0000:0000:0000:0000:0000:0000:0000:0000 */ 1444 static char buf[50+1]; 1445 return inet_ntop(AF_INET6, addrp, buf, sizeof(buf)); 1446} 1447 1448static const char *ip6addr_to_host(const struct in6_addr *addr) 1449{ 1450 static char hostname[NI_MAXHOST]; 1451 struct sockaddr_in6 saddr; 1452 int err; 1453 1454 memset(&saddr, 0, sizeof(struct sockaddr_in6)); 1455 memcpy(&saddr.sin6_addr, addr, sizeof(*addr)); 1456 saddr.sin6_family = AF_INET6; 1457 1458 err = getnameinfo((const void *)&saddr, sizeof(struct sockaddr_in6), 1459 hostname, sizeof(hostname) - 1, NULL, 0, 0); 1460 if (err != 0) { 1461#ifdef DEBUG 1462 fprintf(stderr,"IP2Name: %s\n",gai_strerror(err)); 1463#endif 1464 return NULL; 1465 } 1466 1467#ifdef DEBUG 1468 fprintf (stderr, "\naddr2host: %s\n", hostname); 1469#endif 1470 return hostname; 1471} 1472 1473const char *xtables_ip6addr_to_anyname(const struct in6_addr *addr) 1474{ 1475 const char *name; 1476 1477 if ((name = ip6addr_to_host(addr)) != NULL) 1478 return name; 1479 1480 return xtables_ip6addr_to_numeric(addr); 1481} 1482 1483int xtables_ip6mask_to_cidr(const struct in6_addr *k) 1484{ 1485 unsigned int bits = 0; 1486 uint32_t a, b, c, d; 1487 1488 a = ntohl(k->s6_addr32[0]); 1489 b = ntohl(k->s6_addr32[1]); 1490 c = ntohl(k->s6_addr32[2]); 1491 d = ntohl(k->s6_addr32[3]); 1492 while (a & 0x80000000U) { 1493 ++bits; 1494 a <<= 1; 1495 a |= (b >> 31) & 1; 1496 b <<= 1; 1497 b |= (c >> 31) & 1; 1498 c <<= 1; 1499 c |= (d >> 31) & 1; 1500 d <<= 1; 1501 } 1502 if (a != 0 || b != 0 || c != 0 || d != 0) 1503 return -1; 1504 return bits; 1505} 1506 1507const char *xtables_ip6mask_to_numeric(const struct in6_addr *addrp) 1508{ 1509 static char buf[50+2]; 1510 int l = xtables_ip6mask_to_cidr(addrp); 1511 1512 if (l == -1) { 1513 strcpy(buf, "/"); 1514 strcat(buf, xtables_ip6addr_to_numeric(addrp)); 1515 return buf; 1516 } 1517 sprintf(buf, "/%d", l); 1518 return buf; 1519} 1520 1521struct in6_addr *xtables_numeric_to_ip6addr(const char *num) 1522{ 1523 static struct in6_addr ap; 1524 int err; 1525 1526 if ((err = inet_pton(AF_INET6, num, &ap)) == 1) 1527 return ≈ 1528#ifdef DEBUG 1529 fprintf(stderr, "\nnumeric2addr: %d\n", err); 1530#endif 1531 return NULL; 1532} 1533 1534static struct in6_addr * 1535host_to_ip6addr(const char *name, unsigned int *naddr) 1536{ 1537 struct in6_addr *addr; 1538 struct addrinfo hints; 1539 struct addrinfo *res, *p; 1540 int err; 1541 unsigned int i; 1542 1543 memset(&hints, 0, sizeof(hints)); 1544 hints.ai_flags = AI_CANONNAME; 1545 hints.ai_family = AF_INET6; 1546 hints.ai_socktype = SOCK_RAW; 1547 1548 *naddr = 0; 1549 if ((err = getaddrinfo(name, NULL, &hints, &res)) != 0) { 1550#ifdef DEBUG 1551 fprintf(stderr,"Name2IP: %s\n",gai_strerror(err)); 1552#endif 1553 return NULL; 1554 } else { 1555 /* Find length of address chain */ 1556 for (p = res; p != NULL; p = p->ai_next) 1557 ++*naddr; 1558#ifdef DEBUG 1559 fprintf(stderr, "resolved: len=%d %s ", res->ai_addrlen, 1560 xtables_ip6addr_to_numeric(&((struct sockaddr_in6 *)res->ai_addr)->sin6_addr)); 1561#endif 1562 /* Copy each element of the address chain */ 1563 addr = xtables_calloc(*naddr, sizeof(struct in6_addr)); 1564 for (i = 0, p = res; p != NULL; p = p->ai_next) 1565 memcpy(&addr[i++], 1566 &((const struct sockaddr_in6 *)p->ai_addr)->sin6_addr, 1567 sizeof(struct in6_addr)); 1568 freeaddrinfo(res); 1569 return addr; 1570 } 1571 1572 return NULL; 1573} 1574 1575static struct in6_addr *network_to_ip6addr(const char *name) 1576{ 1577 /* abort();*/ 1578 /* TODO: not implemented yet, but the exception breaks the 1579 * name resolvation */ 1580 return NULL; 1581} 1582 1583static struct in6_addr * 1584ip6parse_hostnetwork(const char *name, unsigned int *naddrs) 1585{ 1586 struct in6_addr *addrp, *addrptmp; 1587 1588 if ((addrptmp = xtables_numeric_to_ip6addr(name)) != NULL || 1589 (addrptmp = network_to_ip6addr(name)) != NULL) { 1590 addrp = xtables_malloc(sizeof(struct in6_addr)); 1591 memcpy(addrp, addrptmp, sizeof(*addrp)); 1592 *naddrs = 1; 1593 return addrp; 1594 } 1595 if ((addrp = host_to_ip6addr(name, naddrs)) != NULL) 1596 return addrp; 1597 1598 xt_params->exit_err(PARAMETER_PROBLEM, "host/network `%s' not found", name); 1599} 1600 1601static struct in6_addr *parse_ip6mask(char *mask) 1602{ 1603 static struct in6_addr maskaddr; 1604 struct in6_addr *addrp; 1605 unsigned int bits; 1606 1607 if (mask == NULL) { 1608 /* no mask at all defaults to 128 bits */ 1609 memset(&maskaddr, 0xff, sizeof maskaddr); 1610 return &maskaddr; 1611 } 1612 if ((addrp = xtables_numeric_to_ip6addr(mask)) != NULL) 1613 return addrp; 1614 if (!xtables_strtoui(mask, NULL, &bits, 0, 128)) 1615 xt_params->exit_err(PARAMETER_PROBLEM, 1616 "invalid mask `%s' specified", mask); 1617 if (bits != 0) { 1618 char *p = (void *)&maskaddr; 1619 memset(p, 0xff, bits / 8); 1620 memset(p + (bits / 8) + 1, 0, (128 - bits) / 8); 1621 p[bits/8] = 0xff << (8 - (bits & 7)); 1622 return &maskaddr; 1623 } 1624 1625 memset(&maskaddr, 0, sizeof(maskaddr)); 1626 return &maskaddr; 1627} 1628 1629void 1630xtables_ip6parse_multiple(const char *name, struct in6_addr **addrpp, 1631 struct in6_addr **maskpp, unsigned int *naddrs) 1632{ 1633 static const struct in6_addr zero_addr; 1634 struct in6_addr *addrp; 1635 char buf[256], *p, *next; 1636 unsigned int len, i, j, n, count = 1; 1637 const char *loop = name; 1638 1639 while ((loop = strchr(loop, ',')) != NULL) { 1640 ++count; 1641 ++loop; /* skip ',' */ 1642 } 1643 1644 *addrpp = xtables_malloc(sizeof(struct in6_addr) * count); 1645 *maskpp = xtables_malloc(sizeof(struct in6_addr) * count); 1646 1647 loop = name; 1648 1649 for (i = 0; i < count /*NB: count can grow*/; ++i) { 1650 while (isspace(*loop)) 1651 ++loop; 1652 next = strchr(loop, ','); 1653 if (next != NULL) 1654 len = next - loop; 1655 else 1656 len = strlen(loop); 1657 if (len > sizeof(buf) - 1) 1658 xt_params->exit_err(PARAMETER_PROBLEM, 1659 "Hostname too long"); 1660 1661 strncpy(buf, loop, len); 1662 buf[len] = '\0'; 1663 if ((p = strrchr(buf, '/')) != NULL) { 1664 *p = '\0'; 1665 addrp = parse_ip6mask(p + 1); 1666 } else { 1667 addrp = parse_ip6mask(NULL); 1668 } 1669 memcpy(*maskpp + i, addrp, sizeof(*addrp)); 1670 1671 /* if a null mask is given, the name is ignored, like in "any/0" */ 1672 if (memcmp(*maskpp + i, &zero_addr, sizeof(zero_addr)) == 0) 1673 strcpy(buf, "::"); 1674 1675 addrp = ip6parse_hostnetwork(buf, &n); 1676 if (n > 1) { 1677 count += n - 1; 1678 *addrpp = xtables_realloc(*addrpp, 1679 sizeof(struct in6_addr) * count); 1680 *maskpp = xtables_realloc(*maskpp, 1681 sizeof(struct in6_addr) * count); 1682 for (j = 0; j < n; ++j) 1683 /* for each new addr */ 1684 memcpy(*addrpp + i + j, addrp + j, 1685 sizeof(*addrp)); 1686 for (j = 1; j < n; ++j) 1687 /* for each new mask */ 1688 memcpy(*maskpp + i + j, *maskpp + i, 1689 sizeof(*addrp)); 1690 i += n - 1; 1691 } else { 1692 memcpy(*addrpp + i, addrp, sizeof(*addrp)); 1693 } 1694 /* free what ip6parse_hostnetwork had allocated: */ 1695 free(addrp); 1696 if (next == NULL) 1697 break; 1698 loop = next + 1; 1699 } 1700 *naddrs = count; 1701 for (i = 0; i < count; ++i) 1702 for (j = 0; j < 4; ++j) 1703 (*addrpp+i)->s6_addr32[j] &= (*maskpp+i)->s6_addr32[j]; 1704} 1705 1706void xtables_ip6parse_any(const char *name, struct in6_addr **addrpp, 1707 struct in6_addr *maskp, unsigned int *naddrs) 1708{ 1709 static const struct in6_addr zero_addr; 1710 struct in6_addr *addrp; 1711 unsigned int i, j, k, n; 1712 char buf[256], *p; 1713 1714 strncpy(buf, name, sizeof(buf) - 1); 1715 buf[sizeof(buf)-1] = '\0'; 1716 if ((p = strrchr(buf, '/')) != NULL) { 1717 *p = '\0'; 1718 addrp = parse_ip6mask(p + 1); 1719 } else { 1720 addrp = parse_ip6mask(NULL); 1721 } 1722 memcpy(maskp, addrp, sizeof(*maskp)); 1723 1724 /* if a null mask is given, the name is ignored, like in "any/0" */ 1725 if (memcmp(maskp, &zero_addr, sizeof(zero_addr)) == 0) 1726 strcpy(buf, "::"); 1727 1728 addrp = *addrpp = ip6parse_hostnetwork(buf, naddrs); 1729 n = *naddrs; 1730 for (i = 0, j = 0; i < n; ++i) { 1731 for (k = 0; k < 4; ++k) 1732 addrp[j].s6_addr32[k] &= maskp->s6_addr32[k]; 1733 ++j; 1734 for (k = 0; k < j - 1; ++k) 1735 if (IN6_ARE_ADDR_EQUAL(&addrp[k], &addrp[j - 1])) { 1736 /* 1737 * Nuke the dup by copying an address from the 1738 * tail here, and check the current position 1739 * again (--j). 1740 */ 1741 memcpy(&addrp[--j], &addrp[--*naddrs], 1742 sizeof(struct in_addr)); 1743 break; 1744 } 1745 } 1746} 1747 1748void xtables_save_string(const char *value) 1749{ 1750 static const char no_quote_chars[] = "_-0123456789" 1751 "abcdefghijklmnopqrstuvwxyz" 1752 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; 1753 static const char escape_chars[] = "\"\\'"; 1754 size_t length; 1755 const char *p; 1756 1757 length = strspn(value, no_quote_chars); 1758 if (length > 0 && value[length] == 0) { 1759 /* no quoting required */ 1760 putchar(' '); 1761 fputs(value, stdout); 1762 } else { 1763 /* there is at least one dangerous character in the 1764 value, which we have to quote. Write double quotes 1765 around the value and escape special characters with 1766 a backslash */ 1767 printf(" \""); 1768 1769 for (p = strpbrk(value, escape_chars); p != NULL; 1770 p = strpbrk(value, escape_chars)) { 1771 if (p > value) 1772 fwrite(value, 1, p - value, stdout); 1773 putchar('\\'); 1774 putchar(*p); 1775 value = p + 1; 1776 } 1777 1778 /* print the rest and finish the double quoted 1779 string */ 1780 fputs(value, stdout); 1781 putchar('\"'); 1782 } 1783} 1784 1785const struct xtables_pprot xtables_chain_protos[] = { 1786 {"tcp", IPPROTO_TCP}, 1787 {"sctp", IPPROTO_SCTP}, 1788 {"udp", IPPROTO_UDP}, 1789 {"udplite", IPPROTO_UDPLITE}, 1790 {"icmp", IPPROTO_ICMP}, 1791 {"icmpv6", IPPROTO_ICMPV6}, 1792 {"ipv6-icmp", IPPROTO_ICMPV6}, 1793 {"esp", IPPROTO_ESP}, 1794 {"ah", IPPROTO_AH}, 1795 {"ipv6-mh", IPPROTO_MH}, 1796 {"mh", IPPROTO_MH}, 1797 {"all", 0}, 1798 {NULL}, 1799}; 1800 1801uint16_t 1802xtables_parse_protocol(const char *s) 1803{ 1804 const struct protoent *pent; 1805 unsigned int proto, i; 1806 1807 if (xtables_strtoui(s, NULL, &proto, 0, UINT8_MAX)) 1808 return proto; 1809 1810 /* first deal with the special case of 'all' to prevent 1811 * people from being able to redefine 'all' in nsswitch 1812 * and/or provoke expensive [not working] ldap/nis/... 1813 * lookups */ 1814 if (strcmp(s, "all") == 0) 1815 return 0; 1816 1817 pent = getprotobyname(s); 1818 if (pent != NULL) 1819 return pent->p_proto; 1820 1821 for (i = 0; i < ARRAY_SIZE(xtables_chain_protos); ++i) { 1822 if (xtables_chain_protos[i].name == NULL) 1823 continue; 1824 if (strcmp(s, xtables_chain_protos[i].name) == 0) 1825 return xtables_chain_protos[i].num; 1826 } 1827 xt_params->exit_err(PARAMETER_PROBLEM, 1828 "unknown protocol \"%s\" specified", s); 1829 return -1; 1830} 1831 1832int kernel_version; 1833 1834void get_kernel_version(void) 1835{ 1836 static struct utsname uts; 1837 int x = 0, y = 0, z = 0; 1838 1839 if (uname(&uts) == -1) { 1840 fprintf(stderr, "Unable to retrieve kernel version.\n"); 1841 xtables_free_opts(1); 1842 exit(1); 1843 } 1844 1845 sscanf(uts.release, "%d.%d.%d", &x, &y, &z); 1846 kernel_version = LINUX_VERSION(x, y, z); 1847} 1848