iptables.c

   1 /*
   2  * firewall3 - 3rd OpenWrt UCI firewall implementation
   3  *
   4  *   Copyright (C) 2013 Jo-Philipp Wich <jow@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include "iptables.h"
  20
  21
  22 static struct option base_opts[] = {
  23         { .name = "match",  .has_arg = 1, .val = 'm' },
  24         { .name = "jump",   .has_arg = 1, .val = 'j' },
  25         { NULL }
  26 };
  27
  28 static struct xtables_globals xtg = {
  29         .option_offset = 0,
  30         .program_version = "4",
  31         .orig_opts = base_opts,
  32 };
  33
  34 static struct xtables_globals xtg6 = {
  35         .option_offset = 0,
  36         .program_version = "6",
  37         .orig_opts = base_opts,
  38 };
  39
  40 /* Required by certain extensions like SNAT and DNAT */
  41 int kernel_version = 0;
  42
  43 void
  44 get_kernel_version(void)
  45 {
  46         static struct utsname uts;
  47         int x = 0, y = 0, z = 0;
  48
  49         if (uname(&uts) == -1)
  50                 sprintf(uts.release, "3.0.0");
  51
  52         sscanf(uts.release, "%d.%d.%d", &x, &y, &z);
  53         kernel_version = 0x10000 * x + 0x100 * y + z;
  54 }
  55
  56 #ifdef DISABLE_IPV6
  57 #undef __ipt_module
  58 #define __ipt_module(x) libxt_##x##_init, libipt_##x##_init,
  59 #else
  60 #undef __ipt_module
  61 #define __ipt_module(x) libxt_##x##_init, libipt_##x##_init, libip6t_##x##_init,
  62 #endif
  63
  64 static void fw3_init_extensions(void)
  65 {
  66         int i;
  67         void (*initfuncs[])(void) = { FW3_IPT_MODULES };
  68
  69         for (i = 0; i < sizeof(initfuncs)/sizeof(initfuncs[0]); i++)
  70                 if (initfuncs[i])
  71                         initfuncs[i]();
  72 }
  73
  74 struct fw3_ipt_handle *
  75 fw3_ipt_open(enum fw3_family family, enum fw3_table table)
  76 {
  77         struct fw3_ipt_handle *h;
  78
  79         h = fw3_alloc(sizeof(*h));
  80
  81         xtables_init();
  82
  83         if (family == FW3_FAMILY_V6)
  84         {
  85 #ifndef DISABLE_IPV6
  86                 h->family = FW3_FAMILY_V6;
  87                 h->table  = table;
  88                 h->handle = ip6tc_init(fw3_flag_names[table]);
  89
  90                 xtables_set_params(&xtg6);
  91                 xtables_set_nfproto(NFPROTO_IPV6);
  92 #endif
  93         }
  94         else
  95         {
  96                 h->family = FW3_FAMILY_V4;
  97                 h->table  = table;
  98                 h->handle = iptc_init(fw3_flag_names[table]);
  99
 100                 xtables_set_params(&xtg);
 101                 xtables_set_nfproto(NFPROTO_IPV4);
 102         }
 103
 104         if (!h->handle)
 105         {
 106                 free(h);
 107                 return NULL;
 108         }
 109
 110         fw3_xt_reset();
 111         fw3_init_extensions();
 112
 113         return h;
 114 }
 115
 116 static void
 117 debug(struct fw3_ipt_handle *h, const char *fmt, ...)
 118 {
 119         va_list ap;
 120
 121         printf("%s -t %s ", (h->family == FW3_FAMILY_V6) ? "ip6tables" : "iptables",
 122                             fw3_flag_names[h->table]);
 123
 124         va_start(ap, fmt);
 125         vprintf(fmt, ap);
 126         va_end(ap);
 127 }
 128
 129 void
 130 fw3_ipt_set_policy(struct fw3_ipt_handle *h, const char *chain,
 131                    enum fw3_flag policy)
 132 {
 133         if (fw3_pr_debug)
 134                 debug(h, "-P %s %s\n", chain, fw3_flag_names[policy]);
 135
 136 #ifndef DISABLE_IPV6
 137         if (h->family == FW3_FAMILY_V6)
 138                 ip6tc_set_policy(chain, fw3_flag_names[policy], NULL, h->handle);
 139         else
 140 #endif
 141                 iptc_set_policy(chain, fw3_flag_names[policy], NULL, h->handle);
 142 }
 143
 144 void
 145 fw3_ipt_flush_chain(struct fw3_ipt_handle *h, const char *chain)
 146 {
 147         if (fw3_pr_debug)
 148                 debug(h, "-F %s\n", chain);
 149
 150 #ifndef DISABLE_IPV6
 151         if (h->family == FW3_FAMILY_V6)
 152                 ip6tc_flush_entries(chain, h->handle);
 153         else
 154 #endif
 155                 iptc_flush_entries(chain, h->handle);
 156 }
 157
 158 static void
 159 delete_rules(struct fw3_ipt_handle *h, const char *target)
 160 {
 161         unsigned int num;
 162         const struct ipt_entry *e;
 163         const char *chain;
 164         const char *t;
 165         bool found;
 166
 167 #ifndef DISABLE_IPV6
 168         if (h->family == FW3_FAMILY_V6)
 169         {
 170                 for (chain = ip6tc_first_chain(h->handle);
 171                      chain != NULL;
 172                      chain = ip6tc_next_chain(h->handle))
 173                 {
 174                         do {
 175                                 found = false;
 176
 177                                 const struct ip6t_entry *e6;
 178                                 for (num = 0, e6 = ip6tc_first_rule(chain, h->handle);
 179                                          e6 != NULL;
 180                                          num++, e6 = ip6tc_next_rule(e6, h->handle))
 181                                 {
 182                                         t = ip6tc_get_target(e6, h->handle);
 183
 184                                         if (*t && !strcmp(t, target))
 185                                         {
 186                                                 if (fw3_pr_debug)
 187                                                         debug(h, "-D %s %u\n", chain, num + 1);
 188
 189                                                 ip6tc_delete_num_entry(chain, num, h->handle);
 190                                                 found = true;
 191                                                 break;
 192                                         }
 193                                 }
 194                         } while (found);
 195                 }
 196         }
 197         else
 198 #endif
 199         {
 200                 for (chain = iptc_first_chain(h->handle);
 201                      chain != NULL;
 202                      chain = iptc_next_chain(h->handle))
 203                 {
 204                         do {
 205                                 found = false;
 206
 207                                 for (num = 0, e = iptc_first_rule(chain, h->handle);
 208                                      e != NULL;
 209                                          num++, e = iptc_next_rule(e, h->handle))
 210                                 {
 211                                         t = iptc_get_target(e, h->handle);
 212
 213                                         if (*t && !strcmp(t, target))
 214                                         {
 215                                                 if (fw3_pr_debug)
 216                                                         debug(h, "-D %s %u\n", chain, num + 1);
 217
 218                                                 iptc_delete_num_entry(chain, num, h->handle);
 219                                                 found = true;
 220                                                 break;
 221                                         }
 222                                 }
 223                         } while (found);
 224                 }
 225         }
 226 }
 227
 228 void
 229 fw3_ipt_delete_chain(struct fw3_ipt_handle *h, const char *chain)
 230 {
 231         delete_rules(h, chain);
 232
 233         if (fw3_pr_debug)
 234                 debug(h, "-X %s\n", chain);
 235
 236 #ifndef DISABLE_IPV6
 237         if (h->family == FW3_FAMILY_V6)
 238                 ip6tc_delete_chain(chain, h->handle);
 239         else
 240 #endif
 241                 iptc_delete_chain(chain, h->handle);
 242 }
 243
 244 void
 245 fw3_ipt_create_chain(struct fw3_ipt_handle *h, const char *fmt, ...)
 246 {
 247         char buf[32];
 248         va_list ap;
 249
 250         va_start(ap, fmt);
 251         vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 252         va_end(ap);
 253
 254         if (fw3_pr_debug)
 255                 debug(h, "-N %s\n", buf);
 256
 257         iptc_create_chain(buf, h->handle);
 258 }
 259
 260 void
 261 fw3_ipt_flush(struct fw3_ipt_handle *h)
 262 {
 263         const char *chain;
 264
 265 #ifndef DISABLE_IPV6
 266         if (h->family == FW3_FAMILY_V6)
 267         {
 268                 for (chain = ip6tc_first_chain(h->handle);
 269                      chain != NULL;
 270                      chain = ip6tc_next_chain(h->handle))
 271                 {
 272                         ip6tc_flush_entries(chain, h->handle);
 273                 }
 274
 275                 for (chain = ip6tc_first_chain(h->handle);
 276                      chain != NULL;
 277                      chain = ip6tc_next_chain(h->handle))
 278                 {
 279                         ip6tc_delete_chain(chain, h->handle);
 280                 }
 281         }
 282         else
 283 #endif
 284         {
 285                 for (chain = iptc_first_chain(h->handle);
 286                      chain != NULL;
 287                      chain = iptc_next_chain(h->handle))
 288                 {
 289                         iptc_flush_entries(chain, h->handle);
 290                 }
 291
 292                 for (chain = iptc_first_chain(h->handle);
 293                      chain != NULL;
 294                      chain = iptc_next_chain(h->handle))
 295                 {
 296                         iptc_delete_chain(chain, h->handle);
 297                 }
 298         }
 299 }
 300
 301 void
 302 fw3_ipt_commit(struct fw3_ipt_handle *h)
 303 {
 304         int rv;
 305
 306 #ifndef DISABLE_IPV6
 307         if (h->family == FW3_FAMILY_V6)
 308         {
 309                 rv = ip6tc_commit(h->handle);
 310                 if (!rv)
 311                         warn("ip6tc_commit(): %s", ip6tc_strerror(errno));
 312         }
 313         else
 314 #endif
 315         {
 316                 rv = iptc_commit(h->handle);
 317                 if (!rv)
 318                         warn("iptc_commit(): %s", iptc_strerror(errno));
 319         }
 320 }
 321
 322 void
 323 fw3_ipt_close(struct fw3_ipt_handle *h)
 324 {
 325         if (h->libv)
 326         {
 327                 while (h->libc > 0)
 328                 {
 329                         h->libc--;
 330                         dlclose(h->libv[h->libc]);
 331                 }
 332
 333                 free(h->libv);
 334         }
 335
 336         free(h);
 337 }
 338
 339 struct fw3_ipt_rule *
 340 fw3_ipt_rule_new(struct fw3_ipt_handle *h)
 341 {
 342         struct fw3_ipt_rule *r;
 343
 344         r = fw3_alloc(sizeof(*r));
 345
 346         r->h = h;
 347         r->argv = fw3_alloc(sizeof(char *));
 348         r->argv[r->argc++] = "fw3";
 349
 350         return r;
 351 }
 352
 353
 354 static bool
 355 is_chain(struct fw3_ipt_handle *h, const char *name)
 356 {
 357 #ifndef DISABLE_IPV6
 358         if (h->family == FW3_FAMILY_V6)
 359                 return ip6tc_is_chain(name, h->handle);
 360         else
 361 #endif
 362                 return iptc_is_chain(name, h->handle);
 363 }
 364
 365 static char *
 366 get_protoname(struct fw3_ipt_rule *r)
 367 {
 368         const struct xtables_pprot *pp;
 369
 370         if (r->protocol)
 371                 for (pp = xtables_chain_protos; pp->name; pp++)
 372                         if (pp->num == r->protocol)
 373                                 return (char *)pp->name;
 374
 375         return NULL;
 376 }
 377
 378 static bool
 379 load_extension(struct fw3_ipt_handle *h, const char *name)
 380 {
 381         char path[256];
 382         void *lib, **tmp;
 383         const char *pfx = (h->family == FW3_FAMILY_V6) ? "libip6t" : "libipt";
 384
 385         snprintf(path, sizeof(path), "/usr/lib/iptables/libxt_%s.so", name);
 386         if (!(lib = dlopen(path, RTLD_NOW)))
 387         {
 388                 snprintf(path, sizeof(path), "/usr/lib/iptables/%s_%s.so", pfx, name);
 389                 lib = dlopen(path, RTLD_NOW);
 390         }
 391
 392         if (!lib)
 393                 return false;
 394
 395         tmp = realloc(h->libv, sizeof(lib) * (h->libc + 1));
 396
 397         if (!tmp)
 398                 return false;
 399
 400         h->libv = tmp;
 401         h->libv[h->libc++] = lib;
 402
 403         return true;
 404 }
 405
 406 static struct xtables_match *
 407 find_match(struct fw3_ipt_rule *r, const char *name)
 408 {
 409         struct xtables_match *m;
 410
 411         m = xtables_find_match(name, XTF_DONT_LOAD, &r->matches);
 412
 413         if (!m && load_extension(r->h, name))
 414                 m = xtables_find_match(name, XTF_DONT_LOAD, &r->matches);
 415
 416         return m;
 417 }
 418
 419 static void
 420 init_match(struct fw3_ipt_rule *r, struct xtables_match *m, bool no_clone)
 421 {
 422         size_t s;
 423         struct xtables_globals *g;
 424
 425         if (!m)
 426                 return;
 427
 428         s = XT_ALIGN(sizeof(struct xt_entry_match)) + m->size;
 429
 430         m->m = fw3_alloc(s);
 431
 432         fw3_xt_set_match_name(m);
 433
 434         m->m->u.user.revision = m->revision;
 435         m->m->u.match_size = s;
 436
 437         /* free previous userspace data */
 438         fw3_xt_free_match_udata(m);
 439
 440         if (m->init)
 441                 m->init(m->m);
 442
 443         /* don't merge options if no_clone is set and this match is a clone */
 444         if (no_clone && (m == m->next))
 445                 return;
 446
 447         /* merge option table */
 448         g = (r->h->family == FW3_FAMILY_V6) ? &xtg6 : &xtg;
 449         fw3_xt_merge_match_options(g, m);
 450 }
 451
 452 static bool
 453 need_protomatch(struct fw3_ipt_rule *r, const char *pname)
 454 {
 455         if (!pname)
 456                 return false;
 457
 458         if (!xtables_find_match(pname, XTF_DONT_LOAD, NULL))
 459                 return true;
 460
 461         return !r->protocol_loaded;
 462 }
 463
 464 static struct xtables_match *
 465 load_protomatch(struct fw3_ipt_rule *r)
 466 {
 467         const char *pname = get_protoname(r);
 468
 469         if (!need_protomatch(r, pname))
 470                 return NULL;
 471
 472         return find_match(r, pname);
 473 }
 474
 475 static struct xtables_target *
 476 find_target(struct fw3_ipt_rule *r, const char *name)
 477 {
 478         struct xtables_target *t;
 479
 480         if (is_chain(r->h, name))
 481                 return xtables_find_target(XT_STANDARD_TARGET, XTF_LOAD_MUST_SUCCEED);
 482
 483         t = xtables_find_target(name, XTF_DONT_LOAD);
 484
 485         if (!t && load_extension(r->h, name))
 486                 t = xtables_find_target(name, XTF_DONT_LOAD);
 487
 488         return t;
 489 }
 490
 491 static struct xtables_target *
 492 get_target(struct fw3_ipt_rule *r, const char *name)
 493 {
 494         size_t s;
 495         struct xtables_target *t;
 496         struct xtables_globals *g;
 497
 498         t = find_target(r, name);
 499
 500         if (!t)
 501                 return NULL;
 502
 503         s = XT_ALIGN(sizeof(struct xt_entry_target)) + t->size;
 504         t->t = fw3_alloc(s);
 505
 506         fw3_xt_set_target_name(t, name);
 507
 508         t->t->u.user.revision = t->revision;
 509         t->t->u.target_size = s;
 510
 511         /* free previous userspace data */
 512         fw3_xt_free_target_udata(t);
 513
 514         if (t->init)
 515                 t->init(t->t);
 516
 517         /* merge option table */
 518         g = (r->h->family == FW3_FAMILY_V6) ? &xtg6 : &xtg;
 519         fw3_xt_merge_target_options(g, t);
 520
 521         r->target = t;
 522
 523         return t;
 524 }
 525
 526 void
 527 fw3_ipt_rule_proto(struct fw3_ipt_rule *r, struct fw3_protocol *proto)
 528 {
 529         uint32_t pr;
 530
 531         if (!proto || proto->any)
 532                 return;
 533
 534         pr = proto->protocol;
 535
 536 #ifndef DISABLE_IPV6
 537         if (r->h->family == FW3_FAMILY_V6)
 538         {
 539                 if (pr == 1)
 540                         pr = 58;
 541
 542                 r->e6.ipv6.proto = pr;
 543                 r->e6.ipv6.flags |= IP6T_F_PROTO;
 544
 545                 if (proto->invert)
 546                         r->e6.ipv6.invflags |= XT_INV_PROTO;
 547         }
 548         else
 549 #endif
 550         {
 551                 r->e.ip.proto = pr;
 552
 553                 if (proto->invert)
 554                         r->e.ip.invflags |= XT_INV_PROTO;
 555         }
 556
 557         r->protocol = pr;
 558 }
 559
 560 void
 561 fw3_ipt_rule_in_out(struct fw3_ipt_rule *r,
 562                     struct fw3_device *in, struct fw3_device *out)
 563 {
 564 #ifndef DISABLE_IPV6
 565         if (r->h->family == FW3_FAMILY_V6)
 566         {
 567                 if (in && !in->any)
 568                 {
 569                         xtables_parse_interface(in->name, r->e6.ipv6.iniface,
 570                                                           r->e6.ipv6.iniface_mask);
 571
 572                         if (in->invert)
 573                                 r->e6.ipv6.invflags |= IP6T_INV_VIA_IN;
 574                 }
 575
 576                 if (out && !out->any)
 577                 {
 578                         xtables_parse_interface(out->name, r->e6.ipv6.outiface,
 579                                                            r->e6.ipv6.outiface_mask);
 580
 581                         if (out->invert)
 582                                 r->e6.ipv6.invflags |= IP6T_INV_VIA_OUT;
 583                 }
 584         }
 585         else
 586 #endif
 587         {
 588                 if (in && !in->any)
 589                 {
 590                         xtables_parse_interface(in->name, r->e.ip.iniface,
 591                                                           r->e.ip.iniface_mask);
 592
 593                         if (in->invert)
 594                                 r->e.ip.invflags |= IPT_INV_VIA_IN;
 595                 }
 596
 597                 if (out && !out->any)
 598                 {
 599                         xtables_parse_interface(out->name, r->e.ip.outiface,
 600                                                            r->e.ip.outiface_mask);
 601
 602                         if (out->invert)
 603                                 r->e.ip.invflags |= IPT_INV_VIA_OUT;
 604                 }
 605         }
 606 }
 607
 608
 609 void
 610 fw3_ipt_rule_src_dest(struct fw3_ipt_rule *r,
 611                       struct fw3_address *src, struct fw3_address *dest)
 612 {
 613         if ((src && src->range) || (dest && dest->range))
 614         {
 615                 fw3_ipt_rule_addarg(r, false, "-m", "iprange");
 616         }
 617
 618         if (src && src->set)
 619         {
 620                 if (src->range)
 621                 {
 622                         fw3_ipt_rule_addarg(r, src->invert, "--src-range",
 623                                             fw3_address_to_string(src, false, false));
 624                 }
 625 #ifndef DISABLE_IPV6
 626                 else if (r->h->family == FW3_FAMILY_V6)
 627                 {
 628                         r->e6.ipv6.src = src->address.v6;
 629                         r->e6.ipv6.smsk = src->mask.v6;
 630
 631                         int i;
 632                         for (i = 0; i < 4; i++)
 633                                 r->e6.ipv6.src.s6_addr32[i] &= r->e6.ipv6.smsk.s6_addr32[i];
 634
 635                         if (src->invert)
 636                                 r->e6.ipv6.invflags |= IP6T_INV_SRCIP;
 637                 }
 638 #endif
 639                 else
 640                 {
 641                         r->e.ip.src = src->address.v4;
 642                         r->e.ip.smsk = src->mask.v4;
 643
 644                         r->e.ip.src.s_addr &= r->e.ip.smsk.s_addr;
 645
 646                         if (src->invert)
 647                                 r->e.ip.invflags |= IPT_INV_SRCIP;
 648                 }
 649         }
 650
 651         if (dest && dest->set)
 652         {
 653                 if (dest->range)
 654                 {
 655                         fw3_ipt_rule_addarg(r, dest->invert, "--dst-range",
 656                                             fw3_address_to_string(dest, false, false));
 657                 }
 658 #ifndef DISABLE_IPV6
 659                 else if (r->h->family == FW3_FAMILY_V6)
 660                 {
 661                         r->e6.ipv6.dst = dest->address.v6;
 662                         r->e6.ipv6.dmsk = dest->mask.v6;
 663
 664                         int i;
 665                         for (i = 0; i < 4; i++)
 666                                 r->e6.ipv6.dst.s6_addr32[i] &= r->e6.ipv6.dmsk.s6_addr32[i];
 667
 668                         if (dest->invert)
 669                                 r->e6.ipv6.invflags |= IP6T_INV_DSTIP;
 670                 }
 671 #endif
 672                 else
 673                 {
 674                         r->e.ip.dst = dest->address.v4;
 675                         r->e.ip.dmsk = dest->mask.v4;
 676
 677                         r->e.ip.dst.s_addr &= r->e.ip.dmsk.s_addr;
 678
 679                         if (dest->invert)
 680                                 r->e.ip.invflags |= IPT_INV_DSTIP;
 681                 }
 682         }
 683 }
 684
 685 void
 686 fw3_ipt_rule_sport_dport(struct fw3_ipt_rule *r,
 687                          struct fw3_port *sp, struct fw3_port *dp)
 688 {
 689         char buf[sizeof("65535:65535\0")];
 690
 691         if ((!sp || !sp->set) && (!dp || !dp->set))
 692                 return;
 693
 694         if (!get_protoname(r))
 695                 return;
 696
 697         if (sp && sp->set)
 698         {
 699                 if (sp->port_min == sp->port_max)
 700                         sprintf(buf, "%u", sp->port_min);
 701                 else
 702                         sprintf(buf, "%u:%u", sp->port_min, sp->port_max);
 703
 704                 fw3_ipt_rule_addarg(r, sp->invert, "--sport", buf);
 705         }
 706
 707         if (dp && dp->set)
 708         {
 709                 if (dp->port_min == dp->port_max)
 710                         sprintf(buf, "%u", dp->port_min);
 711                 else
 712                         sprintf(buf, "%u:%u", dp->port_min, dp->port_max);
 713
 714                 fw3_ipt_rule_addarg(r, dp->invert, "--dport", buf);
 715         }
 716 }
 717
 718 void
 719 fw3_ipt_rule_device(struct fw3_ipt_rule *r, const char *device, bool out)
 720 {
 721         if (device) {
 722                 struct fw3_device dev = { .any = false };
 723                 strncpy(dev.name, device, sizeof(dev.name) - 1);
 724                 fw3_ipt_rule_in_out(r, (out) ? NULL : &dev, (out) ? &dev : NULL);
 725         }
 726 }
 727
 728 void
 729 fw3_ipt_rule_mac(struct fw3_ipt_rule *r, struct fw3_mac *mac)
 730 {
 731         char buf[sizeof("ff:ff:ff:ff:ff:ff\0")];
 732         uint8_t *addr = mac->mac.ether_addr_octet;
 733
 734         if (!mac)
 735                 return;
 736
 737         sprintf(buf, "%02x:%02x:%02x:%02x:%02x:%02x",
 738                 addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
 739
 740         fw3_ipt_rule_addarg(r, false, "-m", "mac");
 741         fw3_ipt_rule_addarg(r, mac->invert, "--mac-source", buf);
 742 }
 743
 744 void
 745 fw3_ipt_rule_icmptype(struct fw3_ipt_rule *r, struct fw3_icmptype *icmp)
 746 {
 747         char buf[sizeof("255/255\0")];
 748
 749         if (!icmp)
 750                 return;
 751
 752 #ifndef DISABLE_IPV6
 753         if (r->h->family == FW3_FAMILY_V6)
 754         {
 755                 if (icmp->code6_min == 0 && icmp->code6_max == 0xFF)
 756                         sprintf(buf, "%u", icmp->type6);
 757                 else
 758                         sprintf(buf, "%u/%u", icmp->type6, icmp->code6_min);
 759
 760                 fw3_ipt_rule_addarg(r, icmp->invert, "--icmpv6-type", buf);
 761         }
 762         else
 763 #endif
 764         {
 765                 if (icmp->code_min == 0 && icmp->code_max == 0xFF)
 766                         sprintf(buf, "%u", icmp->type);
 767                 else
 768                         sprintf(buf, "%u/%u", icmp->type, icmp->code_min);
 769
 770                 fw3_ipt_rule_addarg(r, icmp->invert, "--icmp-type", buf);
 771         }
 772 }
 773
 774 void
 775 fw3_ipt_rule_limit(struct fw3_ipt_rule *r, struct fw3_limit *limit)
 776 {
 777         char buf[sizeof("-4294967296/second\0")];
 778
 779         if (!limit || limit->rate <= 0)
 780                 return;
 781
 782         fw3_ipt_rule_addarg(r, false, "-m", "limit");
 783
 784         sprintf(buf, "%u/%s", limit->rate, fw3_limit_units[limit->unit]);
 785         fw3_ipt_rule_addarg(r, limit->invert, "--limit", buf);
 786
 787         if (limit->burst > 0)
 788         {
 789                 sprintf(buf, "%u", limit->burst);
 790                 fw3_ipt_rule_addarg(r, limit->invert, "--limit-burst", buf);
 791         }
 792 }
 793
 794 void
 795 fw3_ipt_rule_ipset(struct fw3_ipt_rule *r, struct fw3_setmatch *match)
 796 {
 797         char buf[sizeof("dst,dst,dst\0")];
 798         char *p = buf;
 799         int i = 0;
 800
 801         struct fw3_ipset *set;
 802         struct fw3_ipset_datatype *type;
 803
 804         if (!match || !match->set || !match->ptr)
 805                 return;
 806
 807         set = match->ptr;
 808         list_for_each_entry(type, &set->datatypes, list)
 809         {
 810                 if (i >= 3)
 811                         break;
 812
 813                 if (p > buf)
 814                         *p++ = ',';
 815
 816                 p += sprintf(p, "%s", match->dir[i] ? match->dir[i] : type->dir);
 817                 i++;
 818         }
 819
 820         fw3_ipt_rule_addarg(r, false, "-m", "set");
 821
 822         fw3_ipt_rule_addarg(r, match->invert, "--match-set",
 823                             set->external ? set->external : set->name);
 824
 825         fw3_ipt_rule_addarg(r, false, buf, NULL);
 826 }
 827
 828 void
 829 fw3_ipt_rule_time(struct fw3_ipt_rule *r, struct fw3_time *time)
 830 {
 831         int i;
 832         struct tm empty = { 0 };
 833
 834         char buf[84]; /* sizeof("1,2,3,...,30,31\0") */
 835         char *p;
 836
 837         bool d1 = memcmp(&time->datestart, &empty, sizeof(empty));
 838         bool d2 = memcmp(&time->datestop, &empty, sizeof(empty));
 839
 840         if (!d1 && !d2 && !time->timestart && !time->timestop &&
 841             !(time->monthdays & 0xFFFFFFFE) && !(time->weekdays & 0xFE))
 842         {
 843                 return;
 844         }
 845
 846         fw3_ipt_rule_addarg(r, false, "-m", "time");
 847
 848         if (time->utc)
 849                 fw3_ipt_rule_addarg(r, false, "--utc", NULL);
 850
 851         if (d1)
 852         {
 853                 strftime(buf, sizeof(buf), "%Y-%m-%dT%H:%M:%S", &time->datestart);
 854                 fw3_ipt_rule_addarg(r, false, "--datestart", buf);
 855         }
 856
 857         if (d2)
 858         {
 859                 strftime(buf, sizeof(buf), "%Y-%m-%dT%H:%M:%S", &time->datestop);
 860                 fw3_ipt_rule_addarg(r, false, "--datestop", buf);
 861         }
 862
 863         if (time->timestart)
 864         {
 865                 sprintf(buf, "%02d:%02d:%02d",
 866                         time->timestart / 3600,
 867                         time->timestart % 3600 / 60,
 868                         time->timestart % 60);
 869
 870                 fw3_ipt_rule_addarg(r, false, "--timestart", buf);
 871         }
 872
 873         if (time->timestop)
 874         {
 875                 sprintf(buf, "%02d:%02d:%02d",
 876                         time->timestop / 3600,
 877                         time->timestop % 3600 / 60,
 878                         time->timestop % 60);
 879
 880                 fw3_ipt_rule_addarg(r, false, "--timestop", buf);
 881         }
 882
 883         if (time->monthdays & 0xFFFFFFFE)
 884         {
 885                 for (i = 1, p = buf; i < 32; i++)
 886                 {
 887                         if (hasbit(time->monthdays, i))
 888                         {
 889                                 if (p > buf)
 890                                         *p++ = ',';
 891
 892                                 p += sprintf(p, "%u", i);
 893                         }
 894                 }
 895
 896                 fw3_ipt_rule_addarg(r, hasbit(time->monthdays, 0), "--monthdays", buf);
 897         }
 898
 899         if (time->weekdays & 0xFE)
 900         {
 901                 for (i = 1, p = buf; i < 8; i++)
 902                 {
 903                         if (hasbit(time->weekdays, i))
 904                         {
 905                                 if (p > buf)
 906                                         *p++ = ',';
 907
 908                                 p += sprintf(p, "%u", i);
 909                         }
 910                 }
 911
 912                 fw3_ipt_rule_addarg(r, hasbit(time->weekdays, 0), "--weekdays", buf);
 913         }
 914 }
 915
 916 void
 917 fw3_ipt_rule_mark(struct fw3_ipt_rule *r, struct fw3_mark *mark)
 918 {
 919         char buf[sizeof("0xFFFFFFFF/0xFFFFFFFF\0")];
 920
 921         if (!mark || !mark->set)
 922                 return;
 923
 924         if (mark->mask < 0xFFFFFFFF)
 925                 sprintf(buf, "0x%x/0x%x", mark->mark, mark->mask);
 926         else
 927                 sprintf(buf, "0x%x", mark->mark);
 928
 929         fw3_ipt_rule_addarg(r, false, "-m", "mark");
 930         fw3_ipt_rule_addarg(r, mark->invert, "--mark", buf);
 931 }
 932
 933 void
 934 fw3_ipt_rule_comment(struct fw3_ipt_rule *r, const char *fmt, ...)
 935 {
 936         va_list ap;
 937         char buf[256];
 938
 939         if (!fmt || !*fmt)
 940                 return;
 941
 942         va_start(ap, fmt);
 943         vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
 944         va_end(ap);
 945
 946         fw3_ipt_rule_addarg(r, false, "-m", "comment");
 947         fw3_ipt_rule_addarg(r, false, "--comment", buf);
 948 }
 949
 950 void
 951 fw3_ipt_rule_extra(struct fw3_ipt_rule *r, const char *extra)
 952 {
 953         char *p, **tmp, *s;
 954
 955         if (!extra || !*extra)
 956                 return;
 957
 958         s = fw3_strdup(extra);
 959
 960         for (p = strtok(s, " \t"); p; p = strtok(NULL, " \t"))
 961         {
 962                 tmp = realloc(r->argv, (r->argc + 1) * sizeof(*r->argv));
 963
 964                 if (!tmp)
 965                         break;
 966
 967                 r->argv = tmp;
 968                 r->argv[r->argc++] = fw3_strdup(p);
 969         }
 970
 971         free(s);
 972 }
 973
 974 #ifndef DISABLE_IPV6
 975 static void
 976 rule_print6(struct ip6t_entry *e)
 977 {
 978         char buf1[INET6_ADDRSTRLEN], buf2[INET6_ADDRSTRLEN];
 979         char *pname;
 980
 981         if (e->ipv6.flags & IP6T_F_PROTO)
 982         {
 983                 if (e->ipv6.flags & XT_INV_PROTO)
 984                         printf(" !");
 985
 986                 pname = get_protoname(container_of(e, struct fw3_ipt_rule, e6));
 987
 988                 if (pname)
 989                         printf(" -p %s", pname);
 990                 else
 991                         printf(" -p %u", e->ipv6.proto);
 992         }
 993
 994         if (e->ipv6.iniface[0])
 995         {
 996                 if (e->ipv6.flags & IP6T_INV_VIA_IN)
 997                         printf(" !");
 998
 999                 printf(" -i %s", e->ipv6.iniface);
1000         }
1001
1002         if (e->ipv6.outiface[0])
1003         {
1004                 if (e->ipv6.flags & IP6T_INV_VIA_OUT)
1005                         printf(" !");
1006
1007                 printf(" -o %s", e->ipv6.outiface);
1008         }
1009
1010         if (memcmp(&e->ipv6.src, &in6addr_any, sizeof(struct in6_addr)))
1011         {
1012                 if (e->ipv6.flags & IP6T_INV_SRCIP)
1013                         printf(" !");
1014
1015                 printf(" -s %s/%s",
1016                        inet_ntop(AF_INET6, &e->ipv6.src, buf1, sizeof(buf1)),
1017                        inet_ntop(AF_INET6, &e->ipv6.smsk, buf2, sizeof(buf2)));
1018         }
1019
1020         if (memcmp(&e->ipv6.dst, &in6addr_any, sizeof(struct in6_addr)))
1021         {
1022                 if (e->ipv6.flags & IP6T_INV_DSTIP)
1023                         printf(" !");
1024
1025                 printf(" -d %s/%s",
1026                        inet_ntop(AF_INET6, &e->ipv6.dst, buf1, sizeof(buf1)),
1027                        inet_ntop(AF_INET6, &e->ipv6.dmsk, buf2, sizeof(buf2)));
1028         }
1029 }
1030 #endif
1031
1032 static void
1033 rule_print4(struct ipt_entry *e)
1034 {
1035         struct in_addr in_zero = { 0 };
1036         char buf1[sizeof("255.255.255.255\0")], buf2[sizeof("255.255.255.255\0")];
1037         char *pname;
1038
1039         if (e->ip.proto)
1040         {
1041                 if (e->ip.flags & XT_INV_PROTO)
1042                         printf(" !");
1043
1044                 pname = get_protoname(container_of(e, struct fw3_ipt_rule, e));
1045
1046                 if (pname)
1047                         printf(" -p %s", pname);
1048                 else
1049                         printf(" -p %u", e->ip.proto);
1050         }
1051
1052         if (e->ip.iniface[0])
1053         {
1054                 if (e->ip.flags & IPT_INV_VIA_IN)
1055                         printf(" !");
1056
1057                 printf(" -i %s", e->ip.iniface);
1058         }
1059
1060         if (e->ip.outiface[0])
1061         {
1062                 if (e->ip.flags & IPT_INV_VIA_OUT)
1063                         printf(" !");
1064
1065                 printf(" -o %s", e->ip.outiface);
1066         }
1067
1068         if (memcmp(&e->ip.src, &in_zero, sizeof(struct in_addr)))
1069         {
1070                 if (e->ip.flags & IPT_INV_SRCIP)
1071                         printf(" !");
1072
1073                 printf(" -s %s/%s",
1074                        inet_ntop(AF_INET, &e->ip.src, buf1, sizeof(buf1)),
1075                        inet_ntop(AF_INET, &e->ip.smsk, buf2, sizeof(buf2)));
1076         }
1077
1078         if (memcmp(&e->ip.dst, &in_zero, sizeof(struct in_addr)))
1079         {
1080                 if (e->ip.flags & IPT_INV_DSTIP)
1081                         printf(" !");
1082
1083                 printf(" -d %s/%s",
1084                        inet_ntop(AF_INET, &e->ip.dst, buf1, sizeof(buf1)),
1085                        inet_ntop(AF_INET, &e->ip.dmsk, buf2, sizeof(buf2)));
1086         }
1087 }
1088
1089 static void
1090 rule_print(struct fw3_ipt_rule *r, const char *prefix, const char *chain)
1091 {
1092         debug(r->h, "%s %s", prefix, chain);
1093
1094 #ifndef DISABLE_IPV6
1095         if (r->h->family == FW3_FAMILY_V6)
1096                 rule_print6(&r->e6);
1097         else
1098 #endif
1099                 rule_print4(&r->e);
1100
1101         fw3_xt_print_matches(&r->e.ip, r->matches);
1102         fw3_xt_print_target(&r->e.ip, r->target);
1103
1104         printf("\n");
1105 }
1106
1107 static bool
1108 parse_option(struct fw3_ipt_rule *r, int optc, bool inv)
1109 {
1110         struct xtables_rule_match *m;
1111         struct xtables_match *em;
1112
1113         /* is a target option */
1114         if (r->target && fw3_xt_has_target_parse(r->target) &&
1115                 optc >= r->target->option_offset &&
1116                 optc < (r->target->option_offset + 256))
1117         {
1118                 xtables_option_tpcall(optc, r->argv, inv, r->target, &r->e);
1119                 return false;
1120         }
1121
1122         /* try to dispatch argument to one of the match parsers */
1123         for (m = r->matches; m; m = m->next)
1124         {
1125                 em = m->match;
1126
1127                 if (m->completed || !fw3_xt_has_match_parse(em))
1128                         continue;
1129
1130                 if (optc < em->option_offset ||
1131                         optc >= (em->option_offset + 256))
1132                         continue;
1133
1134                 xtables_option_mpcall(optc, r->argv, inv, em, &r->e);
1135                 return false;
1136         }
1137
1138         /* unhandled option, might belong to a protocol match */
1139         if ((em = load_protomatch(r)) != NULL)
1140         {
1141                 init_match(r, em, false);
1142
1143                 r->protocol_loaded = true;
1144                 optind--;
1145
1146                 return true;
1147         }
1148
1149         if (optc == ':')
1150                 warn("parse_option(): option '%s' needs argument", r->argv[optind-1]);
1151
1152         if (optc == '?')
1153                 warn("parse_option(): unknown option '%s'", r->argv[optind-1]);
1154
1155         return false;
1156 }
1157
1158 void
1159 fw3_ipt_rule_addarg(struct fw3_ipt_rule *r, bool inv,
1160                     const char *k, const char *v)
1161 {
1162         int n;
1163         char **tmp;
1164
1165         if (!k)
1166                 return;
1167
1168         n = inv + !!k + !!v;
1169         tmp = realloc(r->argv, (r->argc + n) * sizeof(*tmp));
1170
1171         if (!tmp)
1172                 return;
1173
1174         r->argv = tmp;
1175
1176         if (inv)
1177                 r->argv[r->argc++] = fw3_strdup("!");
1178
1179         r->argv[r->argc++] = fw3_strdup(k);
1180
1181         if (v)
1182                 r->argv[r->argc++] = fw3_strdup(v);
1183 }
1184
1185 static unsigned char *
1186 rule_mask(struct fw3_ipt_rule *r)
1187 {
1188         size_t s;
1189         unsigned char *p, *mask = NULL;
1190         struct xtables_rule_match *m;
1191
1192 #define SZ(x) XT_ALIGN(sizeof(struct x))
1193
1194 #ifndef DISABLE_IPV6
1195         if (r->h->family == FW3_FAMILY_V6)
1196         {
1197                 s = SZ(ip6t_entry);
1198
1199                 for (m = r->matches; m; m = m->next)
1200                         s += SZ(ip6t_entry_match) + m->match->size;
1201
1202                 s += SZ(ip6t_entry_target) + r->target->size;
1203
1204                 mask = fw3_alloc(s);
1205                 memset(mask, 0xFF, SZ(ip6t_entry));
1206                 p = mask + SZ(ip6t_entry);
1207
1208                 for (m = r->matches; m; m = m->next)
1209                 {
1210                         memset(p, 0xFF, SZ(ip6t_entry_match) + m->match->userspacesize);
1211                         p += SZ(ip6t_entry_match) + m->match->size;
1212                 }
1213
1214                 memset(p, 0xFF, SZ(ip6t_entry_target) + r->target->userspacesize);
1215         }
1216         else
1217 #endif
1218         {
1219                 s = SZ(ipt_entry);
1220
1221                 for (m = r->matches; m; m = m->next)
1222                         s += SZ(ipt_entry_match) + m->match->size;
1223
1224                 s += SZ(ipt_entry_target) + r->target->size;
1225
1226                 mask = fw3_alloc(s);
1227                 memset(mask, 0xFF, SZ(ipt_entry));
1228                 p = mask + SZ(ipt_entry);
1229
1230                 for (m = r->matches; m; m = m->next)
1231                 {
1232                         memset(p, 0xFF, SZ(ipt_entry_match) + m->match->userspacesize);
1233                         p += SZ(ipt_entry_match) + m->match->size;
1234                 }
1235
1236                 memset(p, 0xFF, SZ(ipt_entry_target) + r->target->userspacesize);
1237         }
1238
1239         return mask;
1240 }
1241
1242 static void *
1243 rule_build(struct fw3_ipt_rule *r)
1244 {
1245         size_t s;
1246         struct xtables_rule_match *m;
1247
1248 #ifndef DISABLE_IPV6
1249         if (r->h->family == FW3_FAMILY_V6)
1250         {
1251                 struct ip6t_entry *e6;
1252
1253                 s = XT_ALIGN(sizeof(struct ip6t_entry));
1254
1255                 for (m = r->matches; m; m = m->next)
1256                         s += m->match->m->u.match_size;
1257
1258                 e6 = fw3_alloc(s + r->target->t->u.target_size);
1259
1260                 memcpy(e6, &r->e6, sizeof(struct ip6t_entry));
1261
1262                 e6->target_offset = s;
1263                 e6->next_offset = s + r->target->t->u.target_size;
1264
1265                 s = 0;
1266
1267                 for (m = r->matches; m; m = m->next)
1268                 {
1269                         memcpy(e6->elems + s, m->match->m, m->match->m->u.match_size);
1270                         s += m->match->m->u.match_size;
1271                 }
1272
1273                 memcpy(e6->elems + s, r->target->t, r->target->t->u.target_size);
1274
1275                 return e6;
1276         }
1277         else
1278 #endif
1279         {
1280                 struct ipt_entry *e;
1281
1282                 s = XT_ALIGN(sizeof(struct ipt_entry));
1283
1284                 for (m = r->matches; m; m = m->next)
1285                         s += m->match->m->u.match_size;
1286
1287                 e = fw3_alloc(s + r->target->t->u.target_size);
1288
1289                 memcpy(e, &r->e, sizeof(struct ipt_entry));
1290
1291                 e->target_offset = s;
1292                 e->next_offset = s + r->target->t->u.target_size;
1293
1294                 s = 0;
1295
1296                 for (m = r->matches; m; m = m->next)
1297                 {
1298                         memcpy(e->elems + s, m->match->m, m->match->m->u.match_size);
1299                         s += m->match->m->u.match_size;
1300                 }
1301
1302                 memcpy(e->elems + s, r->target->t, r->target->t->u.target_size);
1303
1304                 return e;
1305         }
1306 }
1307
1308 void
1309 __fw3_ipt_rule_append(struct fw3_ipt_rule *r, bool repl, const char *fmt, ...)
1310 {
1311         void *rule;
1312         unsigned char *mask;
1313
1314         struct xtables_rule_match *m;
1315         struct xtables_match *em;
1316         struct xtables_target *et;
1317         struct xtables_globals *g;
1318
1319         int i, optc;
1320         bool inv = false;
1321         char buf[32];
1322         va_list ap;
1323
1324         va_start(ap, fmt);
1325         vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
1326         va_end(ap);
1327
1328         g = (r->h->family == FW3_FAMILY_V6) ? &xtg6 : &xtg;
1329         g->opts = g->orig_opts;
1330
1331         optind = 0;
1332         opterr = 0;
1333
1334         while ((optc = getopt_long(r->argc, r->argv, "-:m:j:", g->opts,
1335                                    NULL)) != -1)
1336         {
1337                 switch (optc)
1338                 {
1339                 case 'm':
1340                         em = find_match(r, optarg);
1341
1342                         if (!em)
1343                         {
1344                                 warn("fw3_ipt_rule_append(): Can't find match '%s'", optarg);
1345                                 goto free;
1346                         }
1347
1348                         init_match(r, em, true);
1349                         break;
1350
1351                 case 'j':
1352                         et = get_target(r, optarg);
1353
1354                         if (!et)
1355                         {
1356                                 warn("fw3_ipt_rule_append(): Can't find target '%s'", optarg);
1357                                 goto free;
1358                         }
1359
1360                         break;
1361
1362                 case 1:
1363                         if ((optarg[0] == '!') && (optarg[1] == '\0'))
1364                         {
1365                                 optarg[0] = '\0';
1366                                 inv = true;
1367                                 continue;
1368                         }
1369
1370                         warn("fw3_ipt_rule_append(): Bad argument '%s'", optarg);
1371                         goto free;
1372
1373                 default:
1374                         if (parse_option(r, optc, inv))
1375                                 continue;
1376                         break;
1377                 }
1378
1379                 inv = false;
1380         }
1381
1382         for (m = r->matches; m; m = m->next)
1383                 xtables_option_mfcall(m->match);
1384
1385         if (r->target)
1386                 xtables_option_tfcall(r->target);
1387
1388         rule = rule_build(r);
1389
1390 #ifndef DISABLE_IPV6
1391         if (r->h->family == FW3_FAMILY_V6)
1392         {
1393                 if (repl)
1394                 {
1395                         mask = rule_mask(r);
1396
1397                         while (ip6tc_delete_entry(buf, rule, mask, r->h->handle))
1398                                 if (fw3_pr_debug)
1399                                         rule_print(r, "-D", buf);
1400
1401                         free(mask);
1402                 }
1403
1404                 if (fw3_pr_debug)
1405                         rule_print(r, "-A", buf);
1406
1407                 if (!ip6tc_append_entry(buf, rule, r->h->handle))
1408                         warn("ip6tc_append_entry(): %s", ip6tc_strerror(errno));
1409         }
1410         else
1411 #endif
1412         {
1413                 if (repl)
1414                 {
1415                         mask = rule_mask(r);
1416
1417                         while (iptc_delete_entry(buf, rule, mask, r->h->handle))
1418                                 if (fw3_pr_debug)
1419                                         rule_print(r, "-D", buf);
1420
1421                         free(mask);
1422                 }
1423
1424                 if (fw3_pr_debug)
1425                         rule_print(r, "-A", buf);
1426
1427                 if (!iptc_append_entry(buf, rule, r->h->handle))
1428                         warn("iptc_append_entry(): %s\n", iptc_strerror(errno));
1429         }
1430
1431         free(rule);
1432
1433 free:
1434         for (i = 1; i < r->argc; i++)
1435                 free(r->argv[i]);
1436
1437         free(r->argv);
1438
1439         xtables_rule_matches_free(&r->matches);
1440
1441         if (r->target)
1442                 free(r->target->t);
1443
1444         free(r);
1445
1446         /* reset all targets and matches */
1447         for (em = xtables_matches; em; em = em->next)
1448                 em->mflags = 0;
1449
1450         for (et = xtables_targets; et; et = et->next)
1451         {
1452                 et->tflags = 0;
1453                 et->used = 0;
1454         }
1455
1456         xtables_free_opts(1);
1457 }
1458
1459 struct fw3_ipt_rule *
1460 fw3_ipt_rule_create(struct fw3_ipt_handle *handle, struct fw3_protocol *proto,
1461                     struct fw3_device *in, struct fw3_device *out,
1462                     struct fw3_address *src, struct fw3_address *dest)
1463 {
1464         struct fw3_ipt_rule *r;
1465
1466         r = fw3_ipt_rule_new(handle);
1467
1468         fw3_ipt_rule_proto(r, proto);
1469         fw3_ipt_rule_in_out(r, in, out);
1470         fw3_ipt_rule_src_dest(r, src, dest);
1471
1472         return r;
1473 }