xtables.c revision c0e69db337540b22a3b3f739b1143341e7b759b7
1324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver/* 2324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * (C) 2000-2006 by the netfilter coreteam <coreteam@netfilter.org>: 3324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 4324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * This program is free software; you can redistribute it and/or modify 5324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * it under the terms of the GNU General Public License as published by 6324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * the Free Software Foundation; either version 2 of the License, or 7324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * (at your option) any later version. 8324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 9324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * This program is distributed in the hope that it will be useful, 10324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * but WITHOUT ANY WARRANTY; without even the implied warranty of 11324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * GNU General Public License for more details. 13324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 14324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * You should have received a copy of the GNU General Public License 15324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * along with this program; if not, write to the Free Software 16324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 17324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver */ 18324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include "config.h" 19324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <ctype.h> 20324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <errno.h> 21324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <fcntl.h> 22324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <inttypes.h> 23324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <netdb.h> 24324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <stdarg.h> 25324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <stdbool.h> 26324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <stdio.h> 27324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <stdlib.h> 28324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <string.h> 29324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <unistd.h> 30324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <sys/socket.h> 31324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <sys/stat.h> 32324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <sys/statfs.h> 33324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <sys/types.h> 34324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <sys/wait.h> 35324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <arpa/inet.h> 36324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#if defined(HAVE_LINUX_MAGIC_H) 37324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver# include <linux/magic.h> /* for PROC_SUPER_MAGIC */ 38324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#elif defined(HAVE_LINUX_PROC_FS_H) 39324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver# include <linux/proc_fs.h> /* Linux 2.4 */ 40324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#endif 41324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 42324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <xtables.h> 43324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <limits.h> /* INT_MAX in ip_tables.h/ip6_tables.h */ 44324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <linux/netfilter_ipv4/ip_tables.h> 45324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <linux/netfilter_ipv6/ip6_tables.h> 46324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <libiptc/libxtc.h> 47324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 48324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#ifndef NO_SHARED_LIBS 49324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#include <dlfcn.h> 50324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#endif 51324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#ifndef IPT_SO_GET_REVISION_MATCH /* Old kernel source. */ 52324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver# define IPT_SO_GET_REVISION_MATCH (IPT_BASE_CTL + 2) 53324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver# define IPT_SO_GET_REVISION_TARGET (IPT_BASE_CTL + 3) 54324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#endif 55324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver#ifndef IP6T_SO_GET_REVISION_MATCH /* Old kernel source. */ 56# define IP6T_SO_GET_REVISION_MATCH 68 57# define IP6T_SO_GET_REVISION_TARGET 69 58#endif 59#include <getopt.h> 60#include "iptables/internal.h" 61#include "xshared.h" 62 63#define NPROTO 255 64 65#ifndef PROC_SYS_MODPROBE 66#define PROC_SYS_MODPROBE "/proc/sys/kernel/modprobe" 67#endif 68 69/* we need this for ip6?tables-restore. ip6?tables-restore.c sets line to the 70 * current line of the input file, in order to give a more precise error 71 * message. ip6?tables itself doesn't need this, so it is initialized to the 72 * magic number of -1 */ 73int line = -1; 74 75void basic_exit_err(enum xtables_exittype status, const char *msg, ...) __attribute__((noreturn, format(printf,2,3))); 76 77struct xtables_globals *xt_params = NULL; 78 79void basic_exit_err(enum xtables_exittype status, const char *msg, ...) 80{ 81 va_list args; 82 83 va_start(args, msg); 84 fprintf(stderr, "%s v%s: ", xt_params->program_name, xt_params->program_version); 85 vfprintf(stderr, msg, args); 86 va_end(args); 87 fprintf(stderr, "\n"); 88 exit(status); 89} 90 91void xtables_free_opts(int unused) 92{ 93 if (xt_params->opts != xt_params->orig_opts) { 94 free(xt_params->opts); 95 xt_params->opts = NULL; 96 } 97} 98 99struct option *xtables_merge_options(struct option *orig_opts, 100 struct option *oldopts, 101 const struct option *newopts, 102 unsigned int *option_offset) 103{ 104 unsigned int num_oold = 0, num_old = 0, num_new = 0, i; 105 struct option *merge, *mp; 106 107 if (newopts == NULL) 108 return oldopts; 109 110 for (num_oold = 0; orig_opts[num_oold].name; num_oold++) ; 111 if (oldopts != NULL) 112 for (num_old = 0; oldopts[num_old].name; num_old++) ; 113 for (num_new = 0; newopts[num_new].name; num_new++) ; 114 115 /* 116 * Since @oldopts also has @orig_opts already (and does so at the 117 * start), skip these entries. 118 */ 119 oldopts += num_oold; 120 num_old -= num_oold; 121 122 merge = malloc(sizeof(*mp) * (num_oold + num_old + num_new + 1)); 123 if (merge == NULL) 124 return NULL; 125 126 /* Let the base options -[ADI...] have precedence over everything */ 127 memcpy(merge, orig_opts, sizeof(*mp) * num_oold); 128 mp = merge + num_oold; 129 130 /* Second, the new options */ 131 xt_params->option_offset += XT_OPTION_OFFSET_SCALE; 132 *option_offset = xt_params->option_offset; 133 memcpy(mp, newopts, sizeof(*mp) * num_new); 134 135 for (i = 0; i < num_new; ++i, ++mp) 136 mp->val += *option_offset; 137 138 /* Third, the old options */ 139 memcpy(mp, oldopts, sizeof(*mp) * num_old); 140 mp += num_old; 141 xtables_free_opts(0); 142 143 /* Clear trailing entry */ 144 memset(mp, 0, sizeof(*mp)); 145 return merge; 146} 147 148static const struct xtables_afinfo afinfo_ipv4 = { 149 .kmod = "ip_tables", 150 .proc_exists = "/proc/net/ip_tables_names", 151 .libprefix = "libipt_", 152 .family = NFPROTO_IPV4, 153 .ipproto = IPPROTO_IP, 154 .so_rev_match = IPT_SO_GET_REVISION_MATCH, 155 .so_rev_target = IPT_SO_GET_REVISION_TARGET, 156}; 157 158static const struct xtables_afinfo afinfo_ipv6 = { 159 .kmod = "ip6_tables", 160 .proc_exists = "/proc/net/ip6_tables_names", 161 .libprefix = "libip6t_", 162 .family = NFPROTO_IPV6, 163 .ipproto = IPPROTO_IPV6, 164 .so_rev_match = IP6T_SO_GET_REVISION_MATCH, 165 .so_rev_target = IP6T_SO_GET_REVISION_TARGET, 166}; 167 168const struct xtables_afinfo *afinfo; 169 170/* Search path for Xtables .so files */ 171static const char *xtables_libdir; 172 173/* the path to command to load kernel module */ 174const char *xtables_modprobe_program; 175 176/* Keep track of matches/targets pending full registration: linked lists. */ 177struct xtables_match *xtables_pending_matches; 178struct xtables_target *xtables_pending_targets; 179 180/* Keep track of fully registered external matches/targets: linked lists. */ 181struct xtables_match *xtables_matches; 182struct xtables_target *xtables_targets; 183 184/* Fully register a match/target which was previously partially registered. */ 185static void xtables_fully_register_pending_match(struct xtables_match *me); 186static void xtables_fully_register_pending_target(struct xtables_target *me); 187 188void xtables_init(void) 189{ 190 xtables_libdir = getenv("XTABLES_LIBDIR"); 191 if (xtables_libdir != NULL) 192 return; 193 xtables_libdir = getenv("IPTABLES_LIB_DIR"); 194 if (xtables_libdir != NULL) { 195 fprintf(stderr, "IPTABLES_LIB_DIR is deprecated, " 196 "use XTABLES_LIBDIR.\n"); 197 return; 198 } 199 /* 200 * Well yes, IP6TABLES_LIB_DIR is of lower priority over 201 * IPTABLES_LIB_DIR since this moved to libxtables; I think that is ok 202 * for these env vars are deprecated anyhow, and in light of the 203 * (shared) libxt_*.so files, makes less sense to have 204 * IPTABLES_LIB_DIR != IP6TABLES_LIB_DIR. 205 */ 206 xtables_libdir = getenv("IP6TABLES_LIB_DIR"); 207 if (xtables_libdir != NULL) { 208 fprintf(stderr, "IP6TABLES_LIB_DIR is deprecated, " 209 "use XTABLES_LIBDIR.\n"); 210 return; 211 } 212 xtables_libdir = XTABLES_LIBDIR; 213} 214 215void xtables_set_nfproto(uint8_t nfproto) 216{ 217 switch (nfproto) { 218 case NFPROTO_IPV4: 219 afinfo = &afinfo_ipv4; 220 break; 221 case NFPROTO_IPV6: 222 afinfo = &afinfo_ipv6; 223 break; 224 default: 225 fprintf(stderr, "libxtables: unhandled NFPROTO in %s\n", 226 __func__); 227 } 228} 229 230/** 231 * xtables_set_params - set the global parameters used by xtables 232 * @xtp: input xtables_globals structure 233 * 234 * The app is expected to pass a valid xtables_globals data-filled 235 * with proper values 236 * @xtp cannot be NULL 237 * 238 * Returns -1 on failure to set and 0 on success 239 */ 240int xtables_set_params(struct xtables_globals *xtp) 241{ 242 if (!xtp) { 243 fprintf(stderr, "%s: Illegal global params\n",__func__); 244 return -1; 245 } 246 247 xt_params = xtp; 248 249 if (!xt_params->exit_err) 250 xt_params->exit_err = basic_exit_err; 251 252 return 0; 253} 254 255int xtables_init_all(struct xtables_globals *xtp, uint8_t nfproto) 256{ 257 xtables_init(); 258 xtables_set_nfproto(nfproto); 259 return xtables_set_params(xtp); 260} 261 262/** 263 * xtables_*alloc - wrappers that exit on failure 264 */ 265void *xtables_calloc(size_t count, size_t size) 266{ 267 void *p; 268 269 if ((p = calloc(count, size)) == NULL) { 270 perror("ip[6]tables: calloc failed"); 271 exit(1); 272 } 273 274 return p; 275} 276 277void *xtables_malloc(size_t size) 278{ 279 void *p; 280 281 if ((p = malloc(size)) == NULL) { 282 perror("ip[6]tables: malloc failed"); 283 exit(1); 284 } 285 286 return p; 287} 288 289void *xtables_realloc(void *ptr, size_t size) 290{ 291 void *p; 292 293 if ((p = realloc(ptr, size)) == NULL) { 294 perror("ip[6]tables: realloc failed"); 295 exit(1); 296 } 297 298 return p; 299} 300 301static char *get_modprobe(void) 302{ 303 int procfile; 304 char *ret; 305 306#define PROCFILE_BUFSIZ 1024 307 procfile = open(PROC_SYS_MODPROBE, O_RDONLY); 308 if (procfile < 0) 309 return NULL; 310 if (fcntl(procfile, F_SETFD, FD_CLOEXEC) == -1) { 311 fprintf(stderr, "Could not set close on exec: %s\n", 312 strerror(errno)); 313 exit(1); 314 } 315 316 ret = malloc(PROCFILE_BUFSIZ); 317 if (ret) { 318 memset(ret, 0, PROCFILE_BUFSIZ); 319 switch (read(procfile, ret, PROCFILE_BUFSIZ)) { 320 case -1: goto fail; 321 case PROCFILE_BUFSIZ: goto fail; /* Partial read. Wierd */ 322 } 323 if (ret[strlen(ret)-1]=='\n') 324 ret[strlen(ret)-1]=0; 325 close(procfile); 326 return ret; 327 } 328 fail: 329 free(ret); 330 close(procfile); 331 return NULL; 332} 333 334int xtables_insmod(const char *modname, const char *modprobe, bool quiet) 335{ 336 char *buf = NULL; 337 char *argv[4]; 338 int status; 339 340 /* If they don't explicitly set it, read out of kernel */ 341 if (!modprobe) { 342 buf = get_modprobe(); 343 if (!buf) 344 return -1; 345 modprobe = buf; 346 } 347 348 /* 349 * Need to flush the buffer, or the child may output it again 350 * when switching the program thru execv. 351 */ 352 fflush(stdout); 353 354 switch (vfork()) { 355 case 0: 356 argv[0] = (char *)modprobe; 357 argv[1] = (char *)modname; 358 if (quiet) { 359 argv[2] = "-q"; 360 argv[3] = NULL; 361 } else { 362 argv[2] = NULL; 363 argv[3] = NULL; 364 } 365 execv(argv[0], argv); 366 367 /* not usually reached */ 368 exit(1); 369 case -1: 370 free(buf); 371 return -1; 372 373 default: /* parent */ 374 wait(&status); 375 } 376 377 free(buf); 378 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) 379 return 0; 380 return -1; 381} 382 383/* return true if a given file exists within procfs */ 384static bool proc_file_exists(const char *filename) 385{ 386 struct stat s; 387 struct statfs f; 388 389 if (lstat(filename, &s)) 390 return false; 391 if (!S_ISREG(s.st_mode)) 392 return false; 393 if (statfs(filename, &f)) 394 return false; 395 if (f.f_type != PROC_SUPER_MAGIC) 396 return false; 397 return true; 398} 399 400int xtables_load_ko(const char *modprobe, bool quiet) 401{ 402 static bool loaded = false; 403 int ret; 404 405 if (loaded) 406 return 0; 407 408 if (proc_file_exists(afinfo->proc_exists)) { 409 loaded = true; 410 return 0; 411 }; 412 413 ret = xtables_insmod(afinfo->kmod, modprobe, quiet); 414 if (ret == 0) 415 loaded = true; 416 417 return ret; 418} 419 420/** 421 * xtables_strtou{i,l} - string to number conversion 422 * @s: input string 423 * @end: like strtoul's "end" pointer 424 * @value: pointer for result 425 * @min: minimum accepted value 426 * @max: maximum accepted value 427 * 428 * If @end is NULL, we assume the caller wants a "strict strtoul", and hence 429 * "15a" is rejected. 430 * In either case, the value obtained is compared for min-max compliance. 431 * Base is always 0, i.e. autodetect depending on @s. 432 * 433 * Returns true/false whether number was accepted. On failure, *value has 434 * undefined contents. 435 */ 436bool xtables_strtoul(const char *s, char **end, uintmax_t *value, 437 uintmax_t min, uintmax_t max) 438{ 439 uintmax_t v; 440 const char *p; 441 char *my_end; 442 443 errno = 0; 444 /* Since strtoul allows leading minus, we have to check for ourself. */ 445 for (p = s; isspace(*p); ++p) 446 ; 447 if (*p == '-') 448 return false; 449 v = strtoumax(s, &my_end, 0); 450 if (my_end == s) 451 return false; 452 if (end != NULL) 453 *end = my_end; 454 455 if (errno != ERANGE && min <= v && (max == 0 || v <= max)) { 456 if (value != NULL) 457 *value = v; 458 if (end == NULL) 459 return *my_end == '\0'; 460 return true; 461 } 462 463 return false; 464} 465 466bool xtables_strtoui(const char *s, char **end, unsigned int *value, 467 unsigned int min, unsigned int max) 468{ 469 uintmax_t v; 470 bool ret; 471 472 ret = xtables_strtoul(s, end, &v, min, max); 473 if (value != NULL) 474 *value = v; 475 return ret; 476} 477 478int xtables_service_to_port(const char *name, const char *proto) 479{ 480 struct servent *service; 481 482 if ((service = getservbyname(name, proto)) != NULL) 483 return ntohs((unsigned short) service->s_port); 484 485 return -1; 486} 487 488uint16_t xtables_parse_port(const char *port, const char *proto) 489{ 490 unsigned int portnum; 491 492 if (xtables_strtoui(port, NULL, &portnum, 0, UINT16_MAX) || 493 (portnum = xtables_service_to_port(port, proto)) != (unsigned)-1) 494 return portnum; 495 496 xt_params->exit_err(PARAMETER_PROBLEM, 497 "invalid port/service `%s' specified", port); 498} 499 500void xtables_parse_interface(const char *arg, char *vianame, 501 unsigned char *mask) 502{ 503 unsigned int vialen = strlen(arg); 504 unsigned int i; 505 506 memset(mask, 0, IFNAMSIZ); 507 memset(vianame, 0, IFNAMSIZ); 508 509 if (vialen + 1 > IFNAMSIZ) 510 xt_params->exit_err(PARAMETER_PROBLEM, 511 "interface name `%s' must be shorter than IFNAMSIZ" 512 " (%i)", arg, IFNAMSIZ-1); 513 514 strcpy(vianame, arg); 515 if (vialen == 0) 516 memset(mask, 0, IFNAMSIZ); 517 else if (vianame[vialen - 1] == '+') { 518 memset(mask, 0xFF, vialen - 1); 519 memset(mask + vialen - 1, 0, IFNAMSIZ - vialen + 1); 520 /* Don't remove `+' here! -HW */ 521 } else { 522 /* Include nul-terminator in match */ 523 memset(mask, 0xFF, vialen + 1); 524 memset(mask + vialen + 1, 0, IFNAMSIZ - vialen - 1); 525 for (i = 0; vianame[i]; i++) { 526 if (vianame[i] == '/' || 527 vianame[i] == ' ') { 528 fprintf(stderr, 529 "Warning: weird character in interface" 530 " `%s' ('/' and ' ' are not allowed by the kernel).\n", 531 vianame); 532 break; 533 } 534 } 535 } 536} 537 538#ifndef NO_SHARED_LIBS 539static void *load_extension(const char *search_path, const char *af_prefix, 540 const char *name, bool is_target) 541{ 542 const char *all_prefixes[] = {"libxt_", af_prefix, NULL}; 543 const char **prefix; 544 const char *dir = search_path, *next; 545 void *ptr = NULL; 546 struct stat sb; 547 char path[256]; 548 549 do { 550 next = strchr(dir, ':'); 551 if (next == NULL) 552 next = dir + strlen(dir); 553 554 for (prefix = all_prefixes; *prefix != NULL; ++prefix) { 555 snprintf(path, sizeof(path), "%.*s/%s%s.so", 556 (unsigned int)(next - dir), dir, 557 *prefix, name); 558 559 if (stat(path, &sb) != 0) { 560 if (errno == ENOENT) 561 continue; 562 fprintf(stderr, "%s: %s\n", path, 563 strerror(errno)); 564 return NULL; 565 } 566 if (dlopen(path, RTLD_NOW) == NULL) { 567 fprintf(stderr, "%s: %s\n", path, dlerror()); 568 break; 569 } 570 571 if (is_target) 572 ptr = xtables_find_target(name, XTF_DONT_LOAD); 573 else 574 ptr = xtables_find_match(name, 575 XTF_DONT_LOAD, NULL); 576 577 if (ptr != NULL) 578 return ptr; 579 580 fprintf(stderr, "%s: no \"%s\" extension found for " 581 "this protocol\n", path, name); 582 errno = ENOENT; 583 return NULL; 584 } 585 dir = next + 1; 586 } while (*next != '\0'); 587 588 return NULL; 589} 590#endif 591 592struct xtables_match * 593xtables_find_match(const char *name, enum xtables_tryload tryload, 594 struct xtables_rule_match **matches) 595{ 596 struct xtables_match **dptr; 597 struct xtables_match *ptr; 598 const char *icmp6 = "icmp6"; 599 600 if (strlen(name) >= XT_EXTENSION_MAXNAMELEN) 601 xtables_error(PARAMETER_PROBLEM, 602 "Invalid match name \"%s\" (%u chars max)", 603 name, XT_EXTENSION_MAXNAMELEN - 1); 604 605 /* This is ugly as hell. Nonetheless, there is no way of changing 606 * this without hurting backwards compatibility */ 607 if ( (strcmp(name,"icmpv6") == 0) || 608 (strcmp(name,"ipv6-icmp") == 0) || 609 (strcmp(name,"icmp6") == 0) ) 610 name = icmp6; 611 612 /* Trigger delayed initialization */ 613 for (dptr = &xtables_pending_matches; *dptr; ) { 614 if (strcmp(name, (*dptr)->name) == 0) { 615 ptr = *dptr; 616 *dptr = (*dptr)->next; 617 ptr->next = NULL; 618 xtables_fully_register_pending_match(ptr); 619 } else { 620 dptr = &((*dptr)->next); 621 } 622 } 623 624 for (ptr = xtables_matches; ptr; ptr = ptr->next) { 625 if (strcmp(name, ptr->name) == 0) { 626 struct xtables_match *clone; 627 628 /* First match of this type: */ 629 if (ptr->m == NULL) 630 break; 631 632 /* Second and subsequent clones */ 633 clone = xtables_malloc(sizeof(struct xtables_match)); 634 memcpy(clone, ptr, sizeof(struct xtables_match)); 635 clone->mflags = 0; 636 /* This is a clone: */ 637 clone->next = clone; 638 639 ptr = clone; 640 break; 641 } 642 } 643 644#ifndef NO_SHARED_LIBS 645 if (!ptr && tryload != XTF_DONT_LOAD && tryload != XTF_DURING_LOAD) { 646 ptr = load_extension(xtables_libdir, afinfo->libprefix, 647 name, false); 648 649 if (ptr == NULL && tryload == XTF_LOAD_MUST_SUCCEED) 650 xt_params->exit_err(PARAMETER_PROBLEM, 651 "Couldn't load match `%s':%s\n", 652 name, strerror(errno)); 653 } 654#else 655 if (ptr && !ptr->loaded) { 656 if (tryload != XTF_DONT_LOAD) 657 ptr->loaded = 1; 658 else 659 ptr = NULL; 660 } 661 if(!ptr && (tryload == XTF_LOAD_MUST_SUCCEED)) { 662 xt_params->exit_err(PARAMETER_PROBLEM, 663 "Couldn't find match `%s'\n", name); 664 } 665#endif 666 667 if (ptr && matches) { 668 struct xtables_rule_match **i; 669 struct xtables_rule_match *newentry; 670 671 newentry = xtables_malloc(sizeof(struct xtables_rule_match)); 672 673 for (i = matches; *i; i = &(*i)->next) { 674 if (strcmp(name, (*i)->match->name) == 0) 675 (*i)->completed = true; 676 } 677 newentry->match = ptr; 678 newentry->completed = false; 679 newentry->next = NULL; 680 *i = newentry; 681 } 682 683 return ptr; 684} 685 686struct xtables_target * 687xtables_find_target(const char *name, enum xtables_tryload tryload) 688{ 689 struct xtables_target **dptr; 690 struct xtables_target *ptr; 691 692 /* Standard target? */ 693 if (strcmp(name, "") == 0 694 || strcmp(name, XTC_LABEL_ACCEPT) == 0 695 || strcmp(name, XTC_LABEL_DROP) == 0 696 || strcmp(name, XTC_LABEL_QUEUE) == 0 697 || strcmp(name, XTC_LABEL_RETURN) == 0) 698 name = "standard"; 699 700 /* Trigger delayed initialization */ 701 for (dptr = &xtables_pending_targets; *dptr; ) { 702 if (strcmp(name, (*dptr)->name) == 0) { 703 ptr = *dptr; 704 *dptr = (*dptr)->next; 705 ptr->next = NULL; 706 xtables_fully_register_pending_target(ptr); 707 } else { 708 dptr = &((*dptr)->next); 709 } 710 } 711 712 for (ptr = xtables_targets; ptr; ptr = ptr->next) { 713 if (strcmp(name, ptr->name) == 0) 714 break; 715 } 716 717#ifndef NO_SHARED_LIBS 718 if (!ptr && tryload != XTF_DONT_LOAD && tryload != XTF_DURING_LOAD) { 719 ptr = load_extension(xtables_libdir, afinfo->libprefix, 720 name, true); 721 722 if (ptr == NULL && tryload == XTF_LOAD_MUST_SUCCEED) 723 xt_params->exit_err(PARAMETER_PROBLEM, 724 "Couldn't load target `%s':%s\n", 725 name, strerror(errno)); 726 } 727#else 728 if (ptr && !ptr->loaded) { 729 if (tryload != XTF_DONT_LOAD) 730 ptr->loaded = 1; 731 else 732 ptr = NULL; 733 } 734 if (ptr == NULL && tryload == XTF_LOAD_MUST_SUCCEED) { 735 xt_params->exit_err(PARAMETER_PROBLEM, 736 "Couldn't find target `%s'\n", name); 737 } 738#endif 739 740 if (ptr) 741 ptr->used = 1; 742 743 return ptr; 744} 745 746static int compatible_revision(const char *name, uint8_t revision, int opt) 747{ 748 struct xt_get_revision rev; 749 socklen_t s = sizeof(rev); 750 int max_rev, sockfd; 751 752 sockfd = socket(afinfo->family, SOCK_RAW, IPPROTO_RAW); 753 if (sockfd < 0) { 754 if (errno == EPERM) { 755 /* revision 0 is always supported. */ 756 if (revision != 0) 757 fprintf(stderr, "%s: Could not determine whether " 758 "revision %u is supported, " 759 "assuming it is.\n", 760 name, revision); 761 return 1; 762 } 763 fprintf(stderr, "Could not open socket to kernel: %s\n", 764 strerror(errno)); 765 exit(1); 766 } 767 768 if (fcntl(sockfd, F_SETFD, FD_CLOEXEC) == -1) { 769 fprintf(stderr, "Could not set close on exec: %s\n", 770 strerror(errno)); 771 exit(1); 772 } 773 774 xtables_load_ko(xtables_modprobe_program, true); 775 776 strcpy(rev.name, name); 777 rev.revision = revision; 778 779 max_rev = getsockopt(sockfd, afinfo->ipproto, opt, &rev, &s); 780 if (max_rev < 0) { 781 /* Definitely don't support this? */ 782 if (errno == ENOENT || errno == EPROTONOSUPPORT) { 783 close(sockfd); 784 return 0; 785 } else if (errno == ENOPROTOOPT) { 786 close(sockfd); 787 /* Assume only revision 0 support (old kernel) */ 788 return (revision == 0); 789 } else { 790 fprintf(stderr, "getsockopt failed strangely: %s\n", 791 strerror(errno)); 792 exit(1); 793 } 794 } 795 close(sockfd); 796 return 1; 797} 798 799 800static int compatible_match_revision(const char *name, uint8_t revision) 801{ 802 return compatible_revision(name, revision, afinfo->so_rev_match); 803} 804 805static int compatible_target_revision(const char *name, uint8_t revision) 806{ 807 return compatible_revision(name, revision, afinfo->so_rev_target); 808} 809 810static void xtables_check_options(const char *name, const struct option *opt) 811{ 812 for (; opt->name != NULL; ++opt) 813 if (opt->val < 0 || opt->val >= XT_OPTION_OFFSET_SCALE) { 814 fprintf(stderr, "%s: Extension %s uses invalid " 815 "option value %d\n",xt_params->program_name, 816 name, opt->val); 817 exit(1); 818 } 819} 820 821void xtables_register_match(struct xtables_match *me) 822{ 823 if (me->version == NULL) { 824 fprintf(stderr, "%s: match %s<%u> is missing a version\n", 825 xt_params->program_name, me->name, me->revision); 826 exit(1); 827 } 828 if (strcmp(me->version, XTABLES_VERSION) != 0) { 829 fprintf(stderr, "%s: match \"%s\" has version \"%s\", " 830 "but \"%s\" is required.\n", 831 xt_params->program_name, me->name, 832 me->version, XTABLES_VERSION); 833 exit(1); 834 } 835 836 if (strlen(me->name) >= XT_EXTENSION_MAXNAMELEN) { 837 fprintf(stderr, "%s: match `%s' has invalid name\n", 838 xt_params->program_name, me->name); 839 exit(1); 840 } 841 842 if (me->family >= NPROTO) { 843 fprintf(stderr, 844 "%s: BUG: match %s has invalid protocol family\n", 845 xt_params->program_name, me->name); 846 exit(1); 847 } 848 849 if (me->x6_options != NULL) 850 xtables_option_metavalidate(me->name, me->x6_options); 851 if (me->extra_opts != NULL) 852 xtables_check_options(me->name, me->extra_opts); 853 854 /* ignore not interested match */ 855 if (me->family != afinfo->family && me->family != AF_UNSPEC) 856 return; 857 858 /* place on linked list of matches pending full registration */ 859 me->next = xtables_pending_matches; 860 xtables_pending_matches = me; 861} 862 863static void xtables_fully_register_pending_match(struct xtables_match *me) 864{ 865 struct xtables_match **i, *old; 866 867 old = xtables_find_match(me->name, XTF_DURING_LOAD, NULL); 868 if (old) { 869 if (old->revision == me->revision && 870 old->family == me->family) { 871 fprintf(stderr, 872 "%s: match `%s' already registered.\n", 873 xt_params->program_name, me->name); 874 exit(1); 875 } 876 877 /* Now we have two (or more) options, check compatibility. */ 878 if (compatible_match_revision(old->name, old->revision) 879 && old->revision > me->revision) 880 return; 881 882 /* See if new match can be used. */ 883 if (!compatible_match_revision(me->name, me->revision)) 884 return; 885 886 /* Prefer !AF_UNSPEC over AF_UNSPEC for same revision. */ 887 if (old->revision == me->revision && me->family == AF_UNSPEC) 888 return; 889 890 /* Delete old one. */ 891 for (i = &xtables_matches; *i!=old; i = &(*i)->next); 892 *i = old->next; 893 } 894 895 if (me->size != XT_ALIGN(me->size)) { 896 fprintf(stderr, "%s: match `%s' has invalid size %u.\n", 897 xt_params->program_name, me->name, 898 (unsigned int)me->size); 899 exit(1); 900 } 901 902 /* Append to list. */ 903 for (i = &xtables_matches; *i; i = &(*i)->next); 904 me->next = NULL; 905 *i = me; 906 907 me->m = NULL; 908 me->mflags = 0; 909} 910 911void xtables_register_matches(struct xtables_match *match, unsigned int n) 912{ 913 do { 914 xtables_register_match(&match[--n]); 915 } while (n > 0); 916} 917 918void xtables_register_target(struct xtables_target *me) 919{ 920 if (me->version == NULL) { 921 fprintf(stderr, "%s: target %s<%u> is missing a version\n", 922 xt_params->program_name, me->name, me->revision); 923 exit(1); 924 } 925 if (strcmp(me->version, XTABLES_VERSION) != 0) { 926 fprintf(stderr, "%s: target \"%s\" has version \"%s\", " 927 "but \"%s\" is required.\n", 928 xt_params->program_name, me->name, 929 me->version, XTABLES_VERSION); 930 exit(1); 931 } 932 933 if (strlen(me->name) >= XT_EXTENSION_MAXNAMELEN) { 934 fprintf(stderr, "%s: target `%s' has invalid name\n", 935 xt_params->program_name, me->name); 936 exit(1); 937 } 938 939 if (me->family >= NPROTO) { 940 fprintf(stderr, 941 "%s: BUG: target %s has invalid protocol family\n", 942 xt_params->program_name, me->name); 943 exit(1); 944 } 945 946 if (me->x6_options != NULL) 947 xtables_option_metavalidate(me->name, me->x6_options); 948 if (me->extra_opts != NULL) 949 xtables_check_options(me->name, me->extra_opts); 950 951 /* ignore not interested target */ 952 if (me->family != afinfo->family && me->family != AF_UNSPEC) 953 return; 954 955 /* place on linked list of targets pending full registration */ 956 me->next = xtables_pending_targets; 957 xtables_pending_targets = me; 958} 959 960static void xtables_fully_register_pending_target(struct xtables_target *me) 961{ 962 struct xtables_target *old; 963 964 old = xtables_find_target(me->name, XTF_DURING_LOAD); 965 if (old) { 966 struct xtables_target **i; 967 968 if (old->revision == me->revision && 969 old->family == me->family) { 970 fprintf(stderr, 971 "%s: target `%s' already registered.\n", 972 xt_params->program_name, me->name); 973 exit(1); 974 } 975 976 /* Now we have two (or more) options, check compatibility. */ 977 if (compatible_target_revision(old->name, old->revision) 978 && old->revision > me->revision) 979 return; 980 981 /* See if new target can be used. */ 982 if (!compatible_target_revision(me->name, me->revision)) 983 return; 984 985 /* Prefer !AF_UNSPEC over AF_UNSPEC for same revision. */ 986 if (old->revision == me->revision && me->family == AF_UNSPEC) 987 return; 988 989 /* Delete old one. */ 990 for (i = &xtables_targets; *i!=old; i = &(*i)->next); 991 *i = old->next; 992 } 993 994 if (me->size != XT_ALIGN(me->size)) { 995 fprintf(stderr, "%s: target `%s' has invalid size %u.\n", 996 xt_params->program_name, me->name, 997 (unsigned int)me->size); 998 exit(1); 999 } 1000 1001 /* Prepend to list. */ 1002 me->next = xtables_targets; 1003 xtables_targets = me; 1004 me->t = NULL; 1005 me->tflags = 0; 1006} 1007 1008void xtables_register_targets(struct xtables_target *target, unsigned int n) 1009{ 1010 do { 1011 xtables_register_target(&target[--n]); 1012 } while (n > 0); 1013} 1014 1015/** 1016 * xtables_param_act - act on condition 1017 * @status: a constant from enum xtables_exittype 1018 * 1019 * %XTF_ONLY_ONCE: print error message that option may only be used once. 1020 * @p1: module name (e.g. "mark") 1021 * @p2(...): option in conflict (e.g. "--mark") 1022 * @p3(...): condition to match on (see extensions/ for examples) 1023 * 1024 * %XTF_NO_INVERT: option does not support inversion 1025 * @p1: module name 1026 * @p2: option in conflict 1027 * @p3: condition to match on 1028 * 1029 * %XTF_BAD_VALUE: bad value for option 1030 * @p1: module name 1031 * @p2: option with which the problem occured (e.g. "--mark") 1032 * @p3: string the user passed in (e.g. "99999999999999") 1033 * 1034 * %XTF_ONE_ACTION: two mutually exclusive actions have been specified 1035 * @p1: module name 1036 * 1037 * Displays an error message and exits the program. 1038 */ 1039void xtables_param_act(unsigned int status, const char *p1, ...) 1040{ 1041 const char *p2, *p3; 1042 va_list args; 1043 bool b; 1044 1045 va_start(args, p1); 1046 1047 switch (status) { 1048 case XTF_ONLY_ONCE: 1049 p2 = va_arg(args, const char *); 1050 b = va_arg(args, unsigned int); 1051 if (!b) { 1052 va_end(args); 1053 return; 1054 } 1055 xt_params->exit_err(PARAMETER_PROBLEM, 1056 "%s: \"%s\" option may only be specified once", 1057 p1, p2); 1058 break; 1059 case XTF_NO_INVERT: 1060 p2 = va_arg(args, const char *); 1061 b = va_arg(args, unsigned int); 1062 if (!b) { 1063 va_end(args); 1064 return; 1065 } 1066 xt_params->exit_err(PARAMETER_PROBLEM, 1067 "%s: \"%s\" option cannot be inverted", p1, p2); 1068 break; 1069 case XTF_BAD_VALUE: 1070 p2 = va_arg(args, const char *); 1071 p3 = va_arg(args, const char *); 1072 xt_params->exit_err(PARAMETER_PROBLEM, 1073 "%s: Bad value for \"%s\" option: \"%s\"", 1074 p1, p2, p3); 1075 break; 1076 case XTF_ONE_ACTION: 1077 b = va_arg(args, unsigned int); 1078 if (!b) { 1079 va_end(args); 1080 return; 1081 } 1082 xt_params->exit_err(PARAMETER_PROBLEM, 1083 "%s: At most one action is possible", p1); 1084 break; 1085 default: 1086 xt_params->exit_err(status, p1, args); 1087 break; 1088 } 1089 1090 va_end(args); 1091} 1092 1093const char *xtables_ipaddr_to_numeric(const struct in_addr *addrp) 1094{ 1095 static char buf[20]; 1096 const unsigned char *bytep = (const void *)&addrp->s_addr; 1097 1098 sprintf(buf, "%u.%u.%u.%u", bytep[0], bytep[1], bytep[2], bytep[3]); 1099 return buf; 1100} 1101 1102static const char *ipaddr_to_host(const struct in_addr *addr) 1103{ 1104 struct hostent *host; 1105 1106 host = gethostbyaddr(addr, sizeof(struct in_addr), AF_INET); 1107 if (host == NULL) 1108 return NULL; 1109 1110 return host->h_name; 1111} 1112 1113static const char *ipaddr_to_network(const struct in_addr *addr) 1114{ 1115 struct netent *net; 1116 1117 if ((net = getnetbyaddr(ntohl(addr->s_addr), AF_INET)) != NULL) 1118 return net->n_name; 1119 1120 return NULL; 1121} 1122 1123const char *xtables_ipaddr_to_anyname(const struct in_addr *addr) 1124{ 1125 const char *name; 1126 1127 if ((name = ipaddr_to_host(addr)) != NULL || 1128 (name = ipaddr_to_network(addr)) != NULL) 1129 return name; 1130 1131 return xtables_ipaddr_to_numeric(addr); 1132} 1133 1134const char *xtables_ipmask_to_numeric(const struct in_addr *mask) 1135{ 1136 static char buf[20]; 1137 uint32_t maskaddr, bits; 1138 int i; 1139 1140 maskaddr = ntohl(mask->s_addr); 1141 1142 if (maskaddr == 0xFFFFFFFFL) 1143 /* we don't want to see "/32" */ 1144 return ""; 1145 1146 i = 32; 1147 bits = 0xFFFFFFFEL; 1148 while (--i >= 0 && maskaddr != bits) 1149 bits <<= 1; 1150 if (i >= 0) 1151 sprintf(buf, "/%d", i); 1152 else 1153 /* mask was not a decent combination of 1's and 0's */ 1154 sprintf(buf, "/%s", xtables_ipaddr_to_numeric(mask)); 1155 1156 return buf; 1157} 1158 1159static struct in_addr *__numeric_to_ipaddr(const char *dotted, bool is_mask) 1160{ 1161 static struct in_addr addr; 1162 unsigned char *addrp; 1163 unsigned int onebyte; 1164 char buf[20], *p, *q; 1165 int i; 1166 1167 /* copy dotted string, because we need to modify it */ 1168 strncpy(buf, dotted, sizeof(buf) - 1); 1169 buf[sizeof(buf) - 1] = '\0'; 1170 addrp = (void *)&addr.s_addr; 1171 1172 p = buf; 1173 for (i = 0; i < 3; ++i) { 1174 if ((q = strchr(p, '.')) == NULL) { 1175 if (is_mask) 1176 return NULL; 1177 1178 /* autocomplete, this is a network address */ 1179 if (!xtables_strtoui(p, NULL, &onebyte, 0, UINT8_MAX)) 1180 return NULL; 1181 1182 addrp[i] = onebyte; 1183 while (i < 3) 1184 addrp[++i] = 0; 1185 1186 return &addr; 1187 } 1188 1189 *q = '\0'; 1190 if (!xtables_strtoui(p, NULL, &onebyte, 0, UINT8_MAX)) 1191 return NULL; 1192 1193 addrp[i] = onebyte; 1194 p = q + 1; 1195 } 1196 1197 /* we have checked 3 bytes, now we check the last one */ 1198 if (!xtables_strtoui(p, NULL, &onebyte, 0, UINT8_MAX)) 1199 return NULL; 1200 1201 addrp[3] = onebyte; 1202 return &addr; 1203} 1204 1205struct in_addr *xtables_numeric_to_ipaddr(const char *dotted) 1206{ 1207 return __numeric_to_ipaddr(dotted, false); 1208} 1209 1210struct in_addr *xtables_numeric_to_ipmask(const char *dotted) 1211{ 1212 return __numeric_to_ipaddr(dotted, true); 1213} 1214 1215static struct in_addr *network_to_ipaddr(const char *name) 1216{ 1217 static struct in_addr addr; 1218 struct netent *net; 1219 1220 if ((net = getnetbyname(name)) != NULL) { 1221 if (net->n_addrtype != AF_INET) 1222 return NULL; 1223 addr.s_addr = htonl(net->n_net); 1224 return &addr; 1225 } 1226 1227 return NULL; 1228} 1229 1230static struct in_addr *host_to_ipaddr(const char *name, unsigned int *naddr) 1231{ 1232 struct hostent *host; 1233 struct in_addr *addr; 1234 unsigned int i; 1235 1236 *naddr = 0; 1237 if ((host = gethostbyname(name)) != NULL) { 1238 if (host->h_addrtype != AF_INET || 1239 host->h_length != sizeof(struct in_addr)) 1240 return NULL; 1241 1242 while (host->h_addr_list[*naddr] != NULL) 1243 ++*naddr; 1244 addr = xtables_calloc(*naddr, sizeof(struct in_addr)); 1245 for (i = 0; i < *naddr; i++) 1246 memcpy(&addr[i], host->h_addr_list[i], 1247 sizeof(struct in_addr)); 1248 return addr; 1249 } 1250 1251 return NULL; 1252} 1253 1254static struct in_addr * 1255ipparse_hostnetwork(const char *name, unsigned int *naddrs) 1256{ 1257 struct in_addr *addrptmp, *addrp; 1258 1259 if ((addrptmp = xtables_numeric_to_ipaddr(name)) != NULL || 1260 (addrptmp = network_to_ipaddr(name)) != NULL) { 1261 addrp = xtables_malloc(sizeof(struct in_addr)); 1262 memcpy(addrp, addrptmp, sizeof(*addrp)); 1263 *naddrs = 1; 1264 return addrp; 1265 } 1266 if ((addrptmp = host_to_ipaddr(name, naddrs)) != NULL) 1267 return addrptmp; 1268 1269 xt_params->exit_err(PARAMETER_PROBLEM, "host/network `%s' not found", name); 1270} 1271 1272static struct in_addr *parse_ipmask(const char *mask) 1273{ 1274 static struct in_addr maskaddr; 1275 struct in_addr *addrp; 1276 unsigned int bits; 1277 1278 if (mask == NULL) { 1279 /* no mask at all defaults to 32 bits */ 1280 maskaddr.s_addr = 0xFFFFFFFF; 1281 return &maskaddr; 1282 } 1283 if ((addrp = xtables_numeric_to_ipmask(mask)) != NULL) 1284 /* dotted_to_addr already returns a network byte order addr */ 1285 return addrp; 1286 if (!xtables_strtoui(mask, NULL, &bits, 0, 32)) 1287 xt_params->exit_err(PARAMETER_PROBLEM, 1288 "invalid mask `%s' specified", mask); 1289 if (bits != 0) { 1290 maskaddr.s_addr = htonl(0xFFFFFFFF << (32 - bits)); 1291 return &maskaddr; 1292 } 1293 1294 maskaddr.s_addr = 0U; 1295 return &maskaddr; 1296} 1297 1298void xtables_ipparse_multiple(const char *name, struct in_addr **addrpp, 1299 struct in_addr **maskpp, unsigned int *naddrs) 1300{ 1301 struct in_addr *addrp; 1302 char buf[256], *p, *next; 1303 unsigned int len, i, j, n, count = 1; 1304 const char *loop = name; 1305 1306 while ((loop = strchr(loop, ',')) != NULL) { 1307 ++count; 1308 ++loop; /* skip ',' */ 1309 } 1310 1311 *addrpp = xtables_malloc(sizeof(struct in_addr) * count); 1312 *maskpp = xtables_malloc(sizeof(struct in_addr) * count); 1313 1314 loop = name; 1315 1316 for (i = 0; i < count; ++i) { 1317 next = strchr(loop, ','); 1318 if (next != NULL) 1319 len = next - loop; 1320 else 1321 len = strlen(loop); 1322 if (len > sizeof(buf) - 1) 1323 xt_params->exit_err(PARAMETER_PROBLEM, 1324 "Hostname too long"); 1325 1326 strncpy(buf, loop, len); 1327 buf[len] = '\0'; 1328 if ((p = strrchr(buf, '/')) != NULL) { 1329 *p = '\0'; 1330 addrp = parse_ipmask(p + 1); 1331 } else { 1332 addrp = parse_ipmask(NULL); 1333 } 1334 memcpy(*maskpp + i, addrp, sizeof(*addrp)); 1335 1336 /* if a null mask is given, the name is ignored, like in "any/0" */ 1337 if ((*maskpp + i)->s_addr == 0) 1338 /* 1339 * A bit pointless to process multiple addresses 1340 * in this case... 1341 */ 1342 strcpy(buf, "0.0.0.0"); 1343 1344 addrp = ipparse_hostnetwork(buf, &n); 1345 if (n > 1) { 1346 count += n - 1; 1347 *addrpp = xtables_realloc(*addrpp, 1348 sizeof(struct in_addr) * count); 1349 *maskpp = xtables_realloc(*maskpp, 1350 sizeof(struct in_addr) * count); 1351 for (j = 0; j < n; ++j) 1352 /* for each new addr */ 1353 memcpy(*addrpp + i + j, addrp + j, 1354 sizeof(*addrp)); 1355 for (j = 1; j < n; ++j) 1356 /* for each new mask */ 1357 memcpy(*maskpp + i + j, *maskpp + i, 1358 sizeof(*addrp)); 1359 i += n - 1; 1360 } else { 1361 memcpy(*addrpp + i, addrp, sizeof(*addrp)); 1362 } 1363 /* free what ipparse_hostnetwork had allocated: */ 1364 free(addrp); 1365 if (next == NULL) 1366 break; 1367 loop = next + 1; 1368 } 1369 *naddrs = count; 1370 for (i = 0; i < count; ++i) 1371 (*addrpp+i)->s_addr &= (*maskpp+i)->s_addr; 1372} 1373 1374 1375/** 1376 * xtables_ipparse_any - transform arbitrary name to in_addr 1377 * 1378 * Possible inputs (pseudo regex): 1379 * m{^($hostname|$networkname|$ipaddr)(/$mask)?} 1380 * "1.2.3.4/5", "1.2.3.4", "hostname", "networkname" 1381 */ 1382void xtables_ipparse_any(const char *name, struct in_addr **addrpp, 1383 struct in_addr *maskp, unsigned int *naddrs) 1384{ 1385 unsigned int i, j, k, n; 1386 struct in_addr *addrp; 1387 char buf[256], *p; 1388 1389 strncpy(buf, name, sizeof(buf) - 1); 1390 buf[sizeof(buf) - 1] = '\0'; 1391 if ((p = strrchr(buf, '/')) != NULL) { 1392 *p = '\0'; 1393 addrp = parse_ipmask(p + 1); 1394 } else { 1395 addrp = parse_ipmask(NULL); 1396 } 1397 memcpy(maskp, addrp, sizeof(*maskp)); 1398 1399 /* if a null mask is given, the name is ignored, like in "any/0" */ 1400 if (maskp->s_addr == 0U) 1401 strcpy(buf, "0.0.0.0"); 1402 1403 addrp = *addrpp = ipparse_hostnetwork(buf, naddrs); 1404 n = *naddrs; 1405 for (i = 0, j = 0; i < n; ++i) { 1406 addrp[j++].s_addr &= maskp->s_addr; 1407 for (k = 0; k < j - 1; ++k) 1408 if (addrp[k].s_addr == addrp[j-1].s_addr) { 1409 /* 1410 * Nuke the dup by copying an address from the 1411 * tail here, and check the current position 1412 * again (--j). 1413 */ 1414 memcpy(&addrp[--j], &addrp[--*naddrs], 1415 sizeof(struct in_addr)); 1416 break; 1417 } 1418 } 1419} 1420 1421const char *xtables_ip6addr_to_numeric(const struct in6_addr *addrp) 1422{ 1423 /* 0000:0000:0000:0000:0000:0000:000.000.000.000 1424 * 0000:0000:0000:0000:0000:0000:0000:0000 */ 1425 static char buf[50+1]; 1426 return inet_ntop(AF_INET6, addrp, buf, sizeof(buf)); 1427} 1428 1429static const char *ip6addr_to_host(const struct in6_addr *addr) 1430{ 1431 static char hostname[NI_MAXHOST]; 1432 struct sockaddr_in6 saddr; 1433 int err; 1434 1435 memset(&saddr, 0, sizeof(struct sockaddr_in6)); 1436 memcpy(&saddr.sin6_addr, addr, sizeof(*addr)); 1437 saddr.sin6_family = AF_INET6; 1438 1439 err = getnameinfo((const void *)&saddr, sizeof(struct sockaddr_in6), 1440 hostname, sizeof(hostname) - 1, NULL, 0, 0); 1441 if (err != 0) { 1442#ifdef DEBUG 1443 fprintf(stderr,"IP2Name: %s\n",gai_strerror(err)); 1444#endif 1445 return NULL; 1446 } 1447 1448#ifdef DEBUG 1449 fprintf (stderr, "\naddr2host: %s\n", hostname); 1450#endif 1451 return hostname; 1452} 1453 1454const char *xtables_ip6addr_to_anyname(const struct in6_addr *addr) 1455{ 1456 const char *name; 1457 1458 if ((name = ip6addr_to_host(addr)) != NULL) 1459 return name; 1460 1461 return xtables_ip6addr_to_numeric(addr); 1462} 1463 1464static int ip6addr_prefix_length(const struct in6_addr *k) 1465{ 1466 unsigned int bits = 0; 1467 uint32_t a, b, c, d; 1468 1469 a = ntohl(k->s6_addr32[0]); 1470 b = ntohl(k->s6_addr32[1]); 1471 c = ntohl(k->s6_addr32[2]); 1472 d = ntohl(k->s6_addr32[3]); 1473 while (a & 0x80000000U) { 1474 ++bits; 1475 a <<= 1; 1476 a |= (b >> 31) & 1; 1477 b <<= 1; 1478 b |= (c >> 31) & 1; 1479 c <<= 1; 1480 c |= (d >> 31) & 1; 1481 d <<= 1; 1482 } 1483 if (a != 0 || b != 0 || c != 0 || d != 0) 1484 return -1; 1485 return bits; 1486} 1487 1488const char *xtables_ip6mask_to_numeric(const struct in6_addr *addrp) 1489{ 1490 static char buf[50+2]; 1491 int l = ip6addr_prefix_length(addrp); 1492 1493 if (l == -1) { 1494 strcpy(buf, "/"); 1495 strcat(buf, xtables_ip6addr_to_numeric(addrp)); 1496 return buf; 1497 } 1498 sprintf(buf, "/%d", l); 1499 return buf; 1500} 1501 1502struct in6_addr *xtables_numeric_to_ip6addr(const char *num) 1503{ 1504 static struct in6_addr ap; 1505 int err; 1506 1507 if ((err = inet_pton(AF_INET6, num, &ap)) == 1) 1508 return ≈ 1509#ifdef DEBUG 1510 fprintf(stderr, "\nnumeric2addr: %d\n", err); 1511#endif 1512 return NULL; 1513} 1514 1515static struct in6_addr * 1516host_to_ip6addr(const char *name, unsigned int *naddr) 1517{ 1518 struct in6_addr *addr; 1519 struct addrinfo hints; 1520 struct addrinfo *res, *p; 1521 int err; 1522 unsigned int i; 1523 1524 memset(&hints, 0, sizeof(hints)); 1525 hints.ai_flags = AI_CANONNAME; 1526 hints.ai_family = AF_INET6; 1527 hints.ai_socktype = SOCK_RAW; 1528 1529 *naddr = 0; 1530 if ((err = getaddrinfo(name, NULL, &hints, &res)) != 0) { 1531#ifdef DEBUG 1532 fprintf(stderr,"Name2IP: %s\n",gai_strerror(err)); 1533#endif 1534 return NULL; 1535 } else { 1536 /* Find length of address chain */ 1537 for (p = res; p != NULL; p = p->ai_next) 1538 ++*naddr; 1539#ifdef DEBUG 1540 fprintf(stderr, "resolved: len=%d %s ", res->ai_addrlen, 1541 xtables_ip6addr_to_numeric(&((struct sockaddr_in6 *)res->ai_addr)->sin6_addr)); 1542#endif 1543 /* Copy each element of the address chain */ 1544 addr = xtables_calloc(*naddr, sizeof(struct in6_addr)); 1545 for (i = 0, p = res; p != NULL; p = p->ai_next) 1546 memcpy(&addr[i++], 1547 &((const struct sockaddr_in6 *)p->ai_addr)->sin6_addr, 1548 sizeof(struct in6_addr)); 1549 freeaddrinfo(res); 1550 return addr; 1551 } 1552 1553 return NULL; 1554} 1555 1556static struct in6_addr *network_to_ip6addr(const char *name) 1557{ 1558 /* abort();*/ 1559 /* TODO: not implemented yet, but the exception breaks the 1560 * name resolvation */ 1561 return NULL; 1562} 1563 1564static struct in6_addr * 1565ip6parse_hostnetwork(const char *name, unsigned int *naddrs) 1566{ 1567 struct in6_addr *addrp, *addrptmp; 1568 1569 if ((addrptmp = xtables_numeric_to_ip6addr(name)) != NULL || 1570 (addrptmp = network_to_ip6addr(name)) != NULL) { 1571 addrp = xtables_malloc(sizeof(struct in6_addr)); 1572 memcpy(addrp, addrptmp, sizeof(*addrp)); 1573 *naddrs = 1; 1574 return addrp; 1575 } 1576 if ((addrp = host_to_ip6addr(name, naddrs)) != NULL) 1577 return addrp; 1578 1579 xt_params->exit_err(PARAMETER_PROBLEM, "host/network `%s' not found", name); 1580} 1581 1582static struct in6_addr *parse_ip6mask(char *mask) 1583{ 1584 static struct in6_addr maskaddr; 1585 struct in6_addr *addrp; 1586 unsigned int bits; 1587 1588 if (mask == NULL) { 1589 /* no mask at all defaults to 128 bits */ 1590 memset(&maskaddr, 0xff, sizeof maskaddr); 1591 return &maskaddr; 1592 } 1593 if ((addrp = xtables_numeric_to_ip6addr(mask)) != NULL) 1594 return addrp; 1595 if (!xtables_strtoui(mask, NULL, &bits, 0, 128)) 1596 xt_params->exit_err(PARAMETER_PROBLEM, 1597 "invalid mask `%s' specified", mask); 1598 if (bits != 0) { 1599 char *p = (void *)&maskaddr; 1600 memset(p, 0xff, bits / 8); 1601 memset(p + (bits / 8) + 1, 0, (128 - bits) / 8); 1602 p[bits/8] = 0xff << (8 - (bits & 7)); 1603 return &maskaddr; 1604 } 1605 1606 memset(&maskaddr, 0, sizeof(maskaddr)); 1607 return &maskaddr; 1608} 1609 1610void 1611xtables_ip6parse_multiple(const char *name, struct in6_addr **addrpp, 1612 struct in6_addr **maskpp, unsigned int *naddrs) 1613{ 1614 static const struct in6_addr zero_addr; 1615 struct in6_addr *addrp; 1616 char buf[256], *p, *next; 1617 unsigned int len, i, j, n, count = 1; 1618 const char *loop = name; 1619 1620 while ((loop = strchr(loop, ',')) != NULL) { 1621 ++count; 1622 ++loop; /* skip ',' */ 1623 } 1624 1625 *addrpp = xtables_malloc(sizeof(struct in6_addr) * count); 1626 *maskpp = xtables_malloc(sizeof(struct in6_addr) * count); 1627 1628 loop = name; 1629 1630 for (i = 0; i < count /*NB: count can grow*/; ++i) { 1631 next = strchr(loop, ','); 1632 if (next != NULL) 1633 len = next - loop; 1634 else 1635 len = strlen(loop); 1636 if (len > sizeof(buf) - 1) 1637 xt_params->exit_err(PARAMETER_PROBLEM, 1638 "Hostname too long"); 1639 1640 strncpy(buf, loop, len); 1641 buf[len] = '\0'; 1642 if ((p = strrchr(buf, '/')) != NULL) { 1643 *p = '\0'; 1644 addrp = parse_ip6mask(p + 1); 1645 } else { 1646 addrp = parse_ip6mask(NULL); 1647 } 1648 memcpy(*maskpp + i, addrp, sizeof(*addrp)); 1649 1650 /* if a null mask is given, the name is ignored, like in "any/0" */ 1651 if (memcmp(*maskpp + i, &zero_addr, sizeof(zero_addr)) == 0) 1652 strcpy(buf, "::"); 1653 1654 addrp = ip6parse_hostnetwork(buf, &n); 1655 if (n > 1) { 1656 count += n - 1; 1657 *addrpp = xtables_realloc(*addrpp, 1658 sizeof(struct in6_addr) * count); 1659 *maskpp = xtables_realloc(*maskpp, 1660 sizeof(struct in6_addr) * count); 1661 for (j = 0; j < n; ++j) 1662 /* for each new addr */ 1663 memcpy(*addrpp + i + j, addrp + j, 1664 sizeof(*addrp)); 1665 for (j = 1; j < n; ++j) 1666 /* for each new mask */ 1667 memcpy(*maskpp + i + j, *maskpp + i, 1668 sizeof(*addrp)); 1669 i += n - 1; 1670 } else { 1671 memcpy(*addrpp + i, addrp, sizeof(*addrp)); 1672 } 1673 /* free what ip6parse_hostnetwork had allocated: */ 1674 free(addrp); 1675 if (next == NULL) 1676 break; 1677 loop = next + 1; 1678 } 1679 *naddrs = count; 1680 for (i = 0; i < count; ++i) 1681 for (j = 0; j < 4; ++j) 1682 (*addrpp+i)->s6_addr32[j] &= (*maskpp+i)->s6_addr32[j]; 1683} 1684 1685void xtables_ip6parse_any(const char *name, struct in6_addr **addrpp, 1686 struct in6_addr *maskp, unsigned int *naddrs) 1687{ 1688 static const struct in6_addr zero_addr; 1689 struct in6_addr *addrp; 1690 unsigned int i, j, k, n; 1691 char buf[256], *p; 1692 1693 strncpy(buf, name, sizeof(buf) - 1); 1694 buf[sizeof(buf)-1] = '\0'; 1695 if ((p = strrchr(buf, '/')) != NULL) { 1696 *p = '\0'; 1697 addrp = parse_ip6mask(p + 1); 1698 } else { 1699 addrp = parse_ip6mask(NULL); 1700 } 1701 memcpy(maskp, addrp, sizeof(*maskp)); 1702 1703 /* if a null mask is given, the name is ignored, like in "any/0" */ 1704 if (memcmp(maskp, &zero_addr, sizeof(zero_addr)) == 0) 1705 strcpy(buf, "::"); 1706 1707 addrp = *addrpp = ip6parse_hostnetwork(buf, naddrs); 1708 n = *naddrs; 1709 for (i = 0, j = 0; i < n; ++i) { 1710 for (k = 0; k < 4; ++k) 1711 addrp[j].s6_addr32[k] &= maskp->s6_addr32[k]; 1712 ++j; 1713 for (k = 0; k < j - 1; ++k) 1714 if (IN6_ARE_ADDR_EQUAL(&addrp[k], &addrp[j - 1])) { 1715 /* 1716 * Nuke the dup by copying an address from the 1717 * tail here, and check the current position 1718 * again (--j). 1719 */ 1720 memcpy(&addrp[--j], &addrp[--*naddrs], 1721 sizeof(struct in_addr)); 1722 break; 1723 } 1724 } 1725} 1726 1727void xtables_save_string(const char *value) 1728{ 1729 static const char no_quote_chars[] = "_-0123456789" 1730 "abcdefghijklmnopqrstuvwxyz" 1731 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; 1732 static const char escape_chars[] = "\"\\'"; 1733 size_t length; 1734 const char *p; 1735 1736 length = strspn(value, no_quote_chars); 1737 if (length > 0 && value[length] == 0) { 1738 /* no quoting required */ 1739 putchar(' '); 1740 fputs(value, stdout); 1741 } else { 1742 /* there is at least one dangerous character in the 1743 value, which we have to quote. Write double quotes 1744 around the value and escape special characters with 1745 a backslash */ 1746 printf(" \""); 1747 1748 for (p = strpbrk(value, escape_chars); p != NULL; 1749 p = strpbrk(value, escape_chars)) { 1750 if (p > value) 1751 fwrite(value, 1, p - value, stdout); 1752 putchar('\\'); 1753 putchar(*p); 1754 value = p + 1; 1755 } 1756 1757 /* print the rest and finish the double quoted 1758 string */ 1759 fputs(value, stdout); 1760 putchar('\"'); 1761 } 1762} 1763 1764/** 1765 * Check for option-intrapositional negation. 1766 * Do not use in new code. 1767 */ 1768int xtables_check_inverse(const char option[], int *invert, 1769 int *my_optind, int argc, char **argv) 1770{ 1771 if (option == NULL || strcmp(option, "!") != 0) 1772 return false; 1773 1774 fprintf(stderr, "Using intrapositioned negation " 1775 "(`--option ! this`) is deprecated in favor of " 1776 "extrapositioned (`! --option this`).\n"); 1777 1778 if (*invert) 1779 xt_params->exit_err(PARAMETER_PROBLEM, 1780 "Multiple `!' flags not allowed"); 1781 *invert = true; 1782 if (my_optind != NULL) { 1783 optarg = argv[*my_optind]; 1784 ++*my_optind; 1785 if (argc && *my_optind > argc) 1786 xt_params->exit_err(PARAMETER_PROBLEM, 1787 "no argument following `!'"); 1788 } 1789 1790 return true; 1791} 1792 1793const struct xtables_pprot xtables_chain_protos[] = { 1794 {"tcp", IPPROTO_TCP}, 1795 {"sctp", IPPROTO_SCTP}, 1796 {"udp", IPPROTO_UDP}, 1797 {"udplite", IPPROTO_UDPLITE}, 1798 {"icmp", IPPROTO_ICMP}, 1799 {"icmpv6", IPPROTO_ICMPV6}, 1800 {"ipv6-icmp", IPPROTO_ICMPV6}, 1801 {"esp", IPPROTO_ESP}, 1802 {"ah", IPPROTO_AH}, 1803 {"ipv6-mh", IPPROTO_MH}, 1804 {"mh", IPPROTO_MH}, 1805 {"all", 0}, 1806 {NULL}, 1807}; 1808 1809uint16_t 1810xtables_parse_protocol(const char *s) 1811{ 1812 const struct protoent *pent; 1813 unsigned int proto, i; 1814 1815 if (xtables_strtoui(s, NULL, &proto, 0, UINT8_MAX)) 1816 return proto; 1817 1818 /* first deal with the special case of 'all' to prevent 1819 * people from being able to redefine 'all' in nsswitch 1820 * and/or provoke expensive [not working] ldap/nis/... 1821 * lookups */ 1822 if (strcmp(s, "all") == 0) 1823 return 0; 1824 1825 pent = getprotobyname(s); 1826 if (pent != NULL) 1827 return pent->p_proto; 1828 1829 for (i = 0; i < ARRAY_SIZE(xtables_chain_protos); ++i) { 1830 if (xtables_chain_protos[i].name == NULL) 1831 continue; 1832 if (strcmp(s, xtables_chain_protos[i].name) == 0) 1833 return xtables_chain_protos[i].num; 1834 } 1835 xt_params->exit_err(PARAMETER_PROBLEM, 1836 "unknown protocol \"%s\" specified", s); 1837 return -1; 1838} 1839