contrib/fwd/src/fwd_rules.c

   1 /*
   2  * fwd - OpenWrt firewall daemon - iptables rule set
   3  *
   4  *   Copyright (C) 2009 Jo-Philipp Wich <xm@subsignal.org>
   5  *
   6  * The fwd program is free software: you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License version 2
   8  * as published by the Free Software Foundation.
   9  *
  10  * The fwd program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  13  * See the GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with the fwd program. If not, see http://www.gnu.org/licenses/.
  17  */
  18
  19
  20 #include "fwd.h"
  21 #include "fwd_addr.h"
  22 #include "fwd_rules.h"
  23 #include "fwd_xtables.h"
  24
  25
  26 /* -P <chain> <policy> */
  27 static void fwd_r_set_policy(
  28         struct iptc_handle *h, const char *chain, const char *policy
  29 ) {
  30         iptc_set_policy(chain, policy, NULL, h);
  31 }
  32
  33 /* -N <chain> */
  34 static void fwd_r_new_chain(struct iptc_handle *h, const char *chain)
  35 {
  36         iptc_create_chain(chain, h);
  37 }
  38
  39 /* -A <chain1> -j <chain2> */
  40 static void fwd_r_jump_chain(
  41         struct iptc_handle *h, const char *chain1, const char *chain2
  42 ) {
  43         struct fwd_xt_rule *r;
  44
  45         if( (r = fwd_xt_init_rule(h)) != NULL )
  46         {
  47                 fwd_xt_get_target(r, chain2);
  48                 fwd_xt_exec_rule(r, chain1);
  49         }
  50 }
  51
  52 /* -A <chain> -m state --state INVALID -j DROP */
  53 static void fwd_r_drop_invalid(struct iptc_handle *h, const char *chain)
  54 {
  55         struct fwd_xt_rule *r;
  56         struct xtables_match *m;
  57
  58         if( (r = fwd_xt_init_rule(h)) != NULL )
  59         {
  60                 if( (m = fwd_xt_get_match(r, "state")) != NULL )
  61                 {
  62                         fwd_xt_parse_match(r, m, "--state", "INVALID");
  63                         fwd_xt_get_target(r, "DROP");
  64                         fwd_xt_exec_rule(r, chain);
  65                 }
  66         }
  67 }
  68
  69 /* -A <chain> -m state --state RELATED,ESTABLISHED -j ACCEPT */
  70 static void fwd_r_accept_related(struct iptc_handle *h, const char *chain)
  71 {
  72         struct fwd_xt_rule *r;
  73         struct xtables_match *m;
  74
  75         if( (r = fwd_xt_init_rule(h)) != NULL )
  76         {
  77                 if( (m = fwd_xt_get_match(r, "state")) != NULL )
  78                 {
  79                         fwd_xt_parse_match(r, m, "--state", "RELATED,ESTABLISHED");
  80                         fwd_xt_get_target(r, "ACCEPT");
  81                         fwd_xt_exec_rule(r, chain);
  82                 }
  83         }
  84 }
  85
  86 /* -A INPUT -i lo -j ACCEPT; -A OUTPUT -o lo -j ACCEPT */
  87 static void fwd_r_accept_lo(struct iptc_handle *h)
  88 {
  89         struct fwd_network_list n;
  90         struct fwd_xt_rule *r;
  91
  92         n.ifname = "lo";
  93
  94         if( (r = fwd_xt_init_rule(h)) != NULL )
  95         {
  96                 fwd_xt_parse_in(r, &n, 0);
  97                 fwd_xt_get_target(r, "ACCEPT");
  98                 fwd_xt_exec_rule(r, "INPUT");
  99         }
 100
 101         if( (r = fwd_xt_init_rule(h)) != NULL )
 102         {
 103                 fwd_xt_parse_out(r, &n, 0);
 104                 fwd_xt_get_target(r, "ACCEPT");
 105                 fwd_xt_exec_rule(r, "OUTPUT");
 106         }
 107 }
 108
 109 /* build syn_flood chain and jump rule */
 110 static void fwd_r_add_synflood(struct iptc_handle *h, struct fwd_defaults *def)
 111 {
 112         struct fwd_proto p;
 113         struct fwd_xt_rule *r;
 114         struct xtables_match *m;
 115         char buf[32];
 116
 117         /* -N syn_flood */
 118         fwd_r_new_chain(h, "syn_flood");
 119
 120         /* return rule */
 121         if( (r = fwd_xt_init_rule(h)) != NULL )
 122         {
 123                 /* -p tcp */
 124                 p.type = FWD_PR_TCP;
 125                 fwd_xt_parse_proto(r, &p, 0);
 126
 127                 /* -m tcp --syn */
 128                 if( (m = fwd_xt_get_match(r, "tcp")) != NULL )
 129                 {
 130                         fwd_xt_parse_match(r, m, "--syn");
 131                 }
 132
 133                 /* -m limit --limit x/second --limit-burst y */
 134                 if( (m = fwd_xt_get_match(r, "limit")) != NULL )
 135                 {
 136                         sprintf(buf, "%i/second", def->syn_rate);
 137                         fwd_xt_parse_match(r, m, "--limit", buf);
 138
 139                         sprintf(buf, "%i", def->syn_burst);
 140                         fwd_xt_parse_match(r, m, "--limit-burst", buf);
 141                 }
 142
 143                 /* -j RETURN; -A syn_flood */
 144                 fwd_xt_get_target(r, "RETURN");
 145                 fwd_xt_exec_rule(r, "syn_flood");
 146         }
 147
 148         /* drop rule */
 149         if( (r = fwd_xt_init_rule(h)) != NULL )
 150         {
 151                 /* -j DROP; -A syn_flood */
 152                 fwd_xt_get_target(r, "DROP");
 153                 fwd_xt_exec_rule(r, "syn_flood");
 154         }
 155
 156         /* jump to syn_flood rule */
 157         if( (r = fwd_xt_init_rule(h)) != NULL )
 158         {
 159                 /* -p tcp */
 160                 p.type = FWD_PR_TCP;
 161                 fwd_xt_parse_proto(r, &p, 0);
 162
 163                 /* -m tcp --syn */
 164                 if( (m = fwd_xt_get_match(r, "tcp")) != NULL )
 165                 {
 166                         fwd_xt_parse_match(r, m, "--syn");
 167                 }
 168
 169                 /* -j syn_flood; -A INPUT */
 170                 fwd_xt_get_target(r, "syn_flood");
 171                 fwd_xt_exec_rule(r, "INPUT");
 172         }
 173 }
 174
 175 /* build reject target chain */
 176 static void fwd_r_handle_reject(struct iptc_handle *h)
 177 {
 178         struct fwd_proto p;
 179         struct fwd_xt_rule *r;
 180         struct xtables_target *t;
 181
 182         /* -N handle_reject */
 183         fwd_r_new_chain(h, "handle_reject");
 184
 185         /* tcp reject rule */
 186         if( (r = fwd_xt_init_rule(h)) != NULL )
 187         {
 188                 /* -p tcp */
 189                 p.type = FWD_PR_TCP;
 190                 fwd_xt_parse_proto(r, &p, 0);
 191
 192                 /* -j REJECT --reject-with tcp-reset */
 193                 if( (t = fwd_xt_get_target(r, "REJECT")) != NULL )
 194                 {
 195                         fwd_xt_parse_target(r, t, "--reject-with", "tcp-reset");
 196                 }
 197
 198                 /* -A handle_reject */
 199                 fwd_xt_exec_rule(r, "handle_reject");
 200         }
 201
 202         /* common reject rule */
 203         if( (r = fwd_xt_init_rule(h)) != NULL )
 204         {
 205                 /* -j REJECT --reject-with icmp-port-unreachable */
 206                 if( (t = fwd_xt_get_target(r, "REJECT")) != NULL )
 207                 {
 208                         fwd_xt_parse_target(r, t, "--reject-with",
 209                                 "icmp-port-unreachable");
 210                 }
 211
 212                 /* -A handle_reject */
 213                 fwd_xt_exec_rule(r, "handle_reject");
 214         }
 215 }
 216
 217 /* build drop target chain */
 218 static void fwd_r_handle_drop(struct iptc_handle *h)
 219 {
 220         struct fwd_xt_rule *r;
 221
 222         /* -N handle_drop */
 223         fwd_r_new_chain(h, "handle_drop");
 224
 225         /* common drop rule */
 226         if( (r = fwd_xt_init_rule(h)) != NULL )
 227         {
 228                 /* -j DROP; -A handle_reject */
 229                 fwd_xt_get_target(r, "DROP");
 230                 fwd_xt_exec_rule(r, "handle_reject");
 231         }
 232 }
 233
 234 /* build accept target chain */
 235 static void fwd_r_handle_accept(struct iptc_handle *h)
 236 {
 237         struct fwd_xt_rule *r;
 238
 239         /* -N handle_accept */
 240         fwd_r_new_chain(h, "handle_accept");
 241
 242         /* common accept rule */
 243         if( (r = fwd_xt_init_rule(h)) != NULL )
 244         {
 245                 /* -j ACCEPT; -A handle_accept */
 246                 fwd_xt_get_target(r, "ACCEPT");
 247                 fwd_xt_exec_rule(r, "handle_accept");
 248         }
 249 }
 250
 251 /* add comment match */
 252 static void fwd_r_add_comment(
 253         struct fwd_xt_rule *r, const char *t, struct fwd_zone *z,
 254         struct fwd_network_list *n, struct fwd_network_list *n2
 255 ) {
 256         struct xtables_match *m;
 257         char buf[256];
 258
 259         if( (m = fwd_xt_get_match(r, "comment")) != NULL )
 260         {
 261                 if( (n != NULL) && (n2 != NULL) )
 262                         snprintf(buf, sizeof(buf), "%s:%s src:%s dest:%s",
 263                                 t, z->name, n->name, n2->name);
 264                 else if( (n == NULL) && (n2 != NULL) )
 265                         snprintf(buf, sizeof(buf), "%s:%s dest:%s", t, z->name, n2->name);
 266                 else
 267                         snprintf(buf, sizeof(buf), "%s:%s src:%s", t, z->name, n->name);
 268
 269                 fwd_xt_parse_match(r, m, "--comment", buf);
 270         }
 271 }
 272
 273 /* add --sport (if applicable) */
 274 static void fwd_r_add_sport(
 275         struct fwd_xt_rule *r, struct fwd_portrange *p
 276 ) {
 277         int proto = r->entry->ip.proto;
 278         char buf[12];
 279         struct xtables_match *m;
 280
 281         /* have portrange and proto is tcp or udp ... */
 282         if( (p != NULL) && ((proto == 6) || (proto == 17)) )
 283         {
 284                 /* get match ... */
 285                 if( (m = fwd_xt_get_match(r, (proto == 6) ? "tcp" : "udp")) != NULL )
 286                 {
 287                         snprintf(buf, sizeof(buf), "%u:%u", p->min, p->max);
 288                         fwd_xt_parse_match(r, m, "--sport", buf);
 289                 }
 290         }
 291 }
 292
 293 /* add --dport (if applicable) */
 294 static void fwd_r_add_dport(
 295         struct fwd_xt_rule *r, struct fwd_portrange *p
 296 ) {
 297         int proto = r->entry->ip.proto;
 298         char buf[12];
 299         struct xtables_match *m;
 300
 301         /* have portrange and proto is tcp or udp ... */
 302         if( (p != NULL) && ((proto == 6) || (proto == 17)) )
 303         {
 304                 /* get match ... */
 305                 if( (m = fwd_xt_get_match(r, (proto == 6) ? "tcp" : "udp")) != NULL )
 306                 {
 307                         snprintf(buf, sizeof(buf), "%u:%u", p->min, p->max);
 308                         fwd_xt_parse_match(r, m, "--dport", buf);
 309                 }
 310         }
 311 }
 312
 313 /* add --icmp-type (of applicable) */
 314 static void fwd_r_add_icmptype(
 315         struct fwd_xt_rule *r, struct fwd_icmptype *i
 316 ) {
 317         int proto = r->entry->ip.proto;
 318         struct xtables_match *m;
 319         char buf[32];
 320
 321         /* have icmp-type and proto is icmp ... */
 322         if( (i != NULL) && (proto == 1) )
 323         {
 324                 /* get match ... */
 325                 if( (m = fwd_xt_get_match(r, "icmp")) != NULL )
 326                 {
 327                         if( i->name[0] )
 328                                 snprintf(buf, sizeof(buf), "%s", i->name);
 329                         else
 330                                 snprintf(buf, sizeof(buf), "%u/%u", i->type, i->code);
 331
 332                         fwd_xt_parse_match(r, m, "--icmp-type", buf);
 333                 }
 334         }
 335 }
 336
 337 /* add -m mac --mac-source ... */
 338 static void fwd_r_add_srcmac(
 339         struct fwd_xt_rule *r, struct fwd_mac *mac
 340 ) {
 341         struct xtables_match *m;
 342         char buf[18];
 343
 344         if( mac != NULL )
 345         {
 346                 if( (m = fwd_xt_get_match(r, "mac")) != NULL )
 347                 {
 348                         snprintf(buf, sizeof(buf), "%02x:%02x:%02x:%02x:%02x:%02x",
 349                                 mac->mac[0], mac->mac[1], mac->mac[2],
 350                                 mac->mac[3], mac->mac[4], mac->mac[5]);
 351
 352                         fwd_xt_parse_match(r, m, "--mac-source", buf);
 353                 }
 354         }
 355 }
 356
 357 /* add policy target */
 358 static void fwd_r_add_policytarget(
 359         struct fwd_xt_rule *r, enum fwd_policy pol
 360 ) {
 361         switch(pol)
 362         {
 363                 case FWD_P_ACCEPT:
 364                         fwd_xt_get_target(r, "handle_accept");
 365                         break;
 366
 367                 case FWD_P_REJECT:
 368                         fwd_xt_get_target(r, "handle_reject");
 369                         break;
 370
 371                 case FWD_P_DROP:
 372                 case FWD_P_UNSPEC:
 373                         fwd_xt_get_target(r, "handle_drop");
 374                         break;
 375         }
 376 }
 377
 378 /* add dnat target */
 379 static void fwd_r_add_dnattarget(
 380         struct fwd_xt_rule *r, struct fwd_cidr *c, struct fwd_portrange *p
 381 ) {
 382         struct xtables_target *t;
 383         char buf[32];
 384
 385         if( c != NULL )
 386         {
 387                 if( (t = fwd_xt_get_target(r, "DNAT")) != NULL )
 388                 {
 389                         if( p != NULL )
 390                                 snprintf(buf, sizeof(buf), "%s:%u-%u",
 391                                         inet_ntoa(c->addr), p->min, p->max);
 392                         else
 393                                 snprintf(buf, sizeof(buf), "%s", inet_ntoa(c->addr));
 394
 395                         fwd_xt_parse_target(r, t, "--to-destination", buf);
 396                 }
 397         }
 398 }
 399
 400
 401 static void fwd_ipt_defaults_create(struct fwd_data *d)
 402 {
 403         struct fwd_defaults *def = &d->section.defaults;
 404         struct iptc_handle *h_filter, *h_nat;
 405
 406         if( !(h_filter = iptc_init("filter")) || !(h_nat = iptc_init("nat")) )
 407                 fwd_fatal("Unable to obtain libiptc handle");
 408
 409         /* policies */
 410         fwd_r_set_policy(h_filter, "INPUT",
 411                 def->input == FWD_P_ACCEPT ? "ACCEPT" : "DROP");
 412         fwd_r_set_policy(h_filter, "OUTPUT",
 413                 def->output == FWD_P_ACCEPT ? "ACCEPT" : "DROP");
 414         fwd_r_set_policy(h_filter, "FORWARD",
 415                 def->forward == FWD_P_ACCEPT ? "ACCEPT" : "DROP");
 416
 417         /* invalid state drop */
 418         if( def->drop_invalid )
 419         {
 420                 fwd_r_drop_invalid(h_filter, "INPUT");
 421                 fwd_r_drop_invalid(h_filter, "OUTPUT");
 422                 fwd_r_drop_invalid(h_filter, "FORWARD");
 423         }
 424
 425         /* default accept related */
 426         fwd_r_accept_related(h_filter, "INPUT");
 427         fwd_r_accept_related(h_filter, "OUTPUT");
 428         fwd_r_accept_related(h_filter, "FORWARD");
 429
 430         /* default accept on lo */
 431         fwd_r_accept_lo(h_filter);
 432
 433         /* syn flood protection */
 434         if( def->syn_flood )
 435         {
 436                 fwd_r_add_synflood(h_filter, def);
 437         }
 438
 439         /* rule container chains */
 440         fwd_r_new_chain(h_filter, "mssfix");
 441         fwd_r_new_chain(h_filter, "zones");
 442         fwd_r_new_chain(h_filter, "rules");
 443         fwd_r_new_chain(h_filter, "redirects");
 444         fwd_r_new_chain(h_filter, "forwardings");
 445         fwd_r_jump_chain(h_filter, "INPUT", "rules");
 446         fwd_r_jump_chain(h_filter, "FORWARD", "mssfix");
 447         fwd_r_jump_chain(h_filter, "FORWARD", "zones");
 448         fwd_r_jump_chain(h_filter, "FORWARD", "rules");
 449         fwd_r_jump_chain(h_filter, "FORWARD", "redirects");
 450         fwd_r_jump_chain(h_filter, "FORWARD", "forwardings");
 451         fwd_r_new_chain(h_nat, "zonemasq");
 452         fwd_r_new_chain(h_nat, "redirects");
 453         fwd_r_new_chain(h_nat, "loopback");
 454         fwd_r_jump_chain(h_nat, "POSTROUTING", "zonemasq");
 455         fwd_r_jump_chain(h_nat, "PREROUTING", "redirects");
 456         fwd_r_jump_chain(h_nat, "POSTROUTING", "loopback");
 457
 458         /* standard drop, accept, reject chain */
 459         fwd_r_handle_drop(h_filter);
 460         fwd_r_handle_accept(h_filter);
 461         fwd_r_handle_reject(h_filter);
 462
 463
 464         if( !iptc_commit(h_nat) )
 465                 fwd_fatal("Cannot commit nat table: %s", iptc_strerror(errno));
 466
 467         if( !iptc_commit(h_filter) )
 468                 fwd_fatal("Cannot commit filter table: %s", iptc_strerror(errno));
 469
 470         iptc_free(h_nat);
 471         iptc_free(h_filter);
 472 }
 473
 474
 475 void fwd_ipt_build_ruleset(struct fwd_handle *h)
 476 {
 477         struct fwd_data *e;
 478
 479         fwd_xt_init();
 480
 481         for( e = h->conf; e; e = e->next )
 482         {
 483                 switch(e->type)
 484                 {
 485                         case FWD_S_DEFAULTS:
 486                                 printf("\n## DEFAULTS\n");
 487                                 fwd_ipt_defaults_create(e);
 488                                 break;
 489
 490                         case FWD_S_INCLUDE:
 491                                 printf("\n## INCLUDE %s\n", e->section.include.path);
 492                                 break;
 493
 494                         case FWD_S_ZONE:
 495                         case FWD_S_FORWARD:
 496                         case FWD_S_REDIRECT:
 497                         case FWD_S_RULE:
 498                                 /* Make gcc happy */
 499                                 break;
 500                 }
 501         }
 502 }
 503
 504
 505 static struct fwd_zone *
 506 fwd_lookup_zone(struct fwd_handle *h, const char *net)
 507 {
 508         struct fwd_data *e;
 509         struct fwd_network_list *n;
 510
 511         for( e = h->conf; e; e = e->next )
 512                 if( e->type == FWD_S_ZONE )
 513                         for( n = e->section.zone.networks; n; n = n->next )
 514                                 if( !strcmp(n->name, net) )
 515                                         return &e->section.zone;
 516
 517         return NULL;
 518 }
 519
 520 static struct fwd_network_list *
 521 fwd_lookup_network(struct fwd_zone *z, const char *net)
 522 {
 523         struct fwd_network_list *n;
 524
 525         for( n = z->networks; n; n = n->next )
 526                 if( !strcmp(n->name, net) )
 527                         return n;
 528
 529         return NULL;
 530 }
 531
 532 static struct fwd_addr_list *
 533 fwd_lookup_addr(struct fwd_handle *h, struct fwd_network_list *n)
 534 {
 535         struct fwd_addr_list *a;
 536
 537         if( n != NULL )
 538                 for( a = h->addrs; a; a = a->next )
 539                         if( !strcmp(a->ifname, n->ifname) )
 540                                 return a;
 541
 542         return NULL;
 543 }
 544
 545 void fwd_ipt_addif(struct fwd_handle *h, const char *net)
 546 {
 547         struct fwd_data *e;
 548         struct fwd_zone *z;
 549         struct fwd_rule *c;
 550         struct fwd_redirect *r;
 551         struct fwd_forwarding *f;
 552         struct fwd_addr_list *a, *a2;
 553         struct fwd_network_list *n, *n2;
 554         struct fwd_proto p;
 555
 556         struct fwd_xt_rule *x;
 557         struct xtables_match *m;
 558         struct xtables_target *t;
 559
 560         struct iptc_handle *h_filter, *h_nat;
 561
 562         if( !(h_filter = iptc_init("filter")) || !(h_nat = iptc_init("nat")) )
 563                 fwd_fatal("Unable to obtain libiptc handle");
 564
 565
 566         if( !(z = fwd_lookup_zone(h, net)) )
 567                 return;
 568
 569         if( !(n = fwd_lookup_network(z, net)) )
 570                 return;
 571
 572         if( !(a = fwd_lookup_addr(h, n)) )
 573                 return;
 574
 575         printf("\n\n#\n# addif(%s)\n#\n", net);
 576
 577         /* Build masquerading rule */
 578         if( z->masq )
 579         {
 580                 printf("\n# Net %s (%s) - masq\n", n->name, n->ifname);
 581
 582                 if( (x = fwd_xt_init_rule(h_nat)) != NULL )
 583                 {
 584                         fwd_xt_parse_out(x, n, 0);                                      /* -o ... */
 585                         fwd_xt_get_target(x, "MASQUERADE");                     /* -j MASQUERADE */
 586                         fwd_r_add_comment(x, "masq", z, NULL, n);       /* -m comment ... */
 587                         fwd_xt_exec_rule(x, "zonemasq");                        /* -A zonemasq */
 588                 }
 589         }
 590
 591         /* Build MSS fix rule */
 592         if( z->mtu_fix )
 593         {
 594                 printf("\n# Net %s (%s) - mtu_fix\n", n->name, n->ifname);
 595
 596                 if( (x = fwd_xt_init_rule(h_filter)) != NULL )
 597                 {
 598                         p.type = FWD_PR_TCP;
 599                         fwd_xt_parse_out(x, n, 0);                                      /* -o ... */
 600                         fwd_xt_parse_proto(x, &p, 0);                           /* -p tcp */
 601
 602                         /* -m tcp --tcp-flags SYN,RST SYN */
 603                         if( (m = fwd_xt_get_match(x, "tcp")) != NULL )
 604                                 fwd_xt_parse_match(x, m, "--tcp-flags", "SYN,RST", "SYN");
 605
 606                         /* -j TCPMSS --clamp-mss-to-pmtu */
 607                         if( (t = fwd_xt_get_target(x, "TCPMSS")) != NULL )
 608                                 fwd_xt_parse_target(x, t, "--clamp-mss-to-pmtu");
 609
 610                         /* -m comment ... */
 611                         fwd_r_add_comment(x, "mssfix", z, NULL, n);
 612
 613                         /* -A mssfix */
 614                         fwd_xt_exec_rule(x, "mssfix");
 615                 }
 616         }
 617
 618         /* Build intra-zone forwarding rules */
 619         for( n2 = z->networks; n2; n2 = n2->next )
 620         {
 621                 if( (a2 = fwd_lookup_addr(h, n2)) != NULL )
 622                 {
 623                         printf("\n# Net %s (%s) - intra-zone-forwarding"
 624                                " Z:%s N:%s I:%s -> Z:%s N:%s I:%s\n",
 625                                 n->name, n->ifname, z->name, n->name, n->ifname,
 626                                 z->name, n2->name, n2->ifname);
 627
 628                         if( (x = fwd_xt_init_rule(h_filter)) != NULL )
 629                         {
 630                                 fwd_xt_parse_in(x, n, 0);                               /* -i ... */
 631                                 fwd_xt_parse_out(x, n2, 0);                             /* -o ... */
 632                                 fwd_r_add_policytarget(x, z->forward);  /* -j handle_... */
 633                                 fwd_r_add_comment(x, "zone", z, n, n2); /* -m comment ... */
 634                                 fwd_xt_exec_rule(x, "zones");                   /* -A zones */
 635                         }
 636                 }
 637         }
 638
 639         /* Build inter-zone forwarding rules */
 640         for( e = z->forwardings; e && (f = &e->section.forwarding); e = e->next )
 641         {
 642                 for( n2 = f->dest->networks; n2; n2 = n2->next )
 643                 {
 644                         printf("\n# Net %s (%s) - inter-zone-forwarding"
 645                    " Z:%s N:%s I:%s -> Z:%s N:%s I:%s\n",
 646                                 n->name, n->ifname, z->name, n->name, n->ifname,
 647                                 f->dest->name, n2->name, n2->ifname);
 648
 649                         /* Build forwarding rule */
 650                         if( (x = fwd_xt_init_rule(h_filter)) != NULL )
 651                         {
 652                                 fwd_xt_parse_in(x, n, 0);                                       /* -i ... */
 653                                 fwd_xt_parse_out(x, n2, 0);                                     /* -o ... */
 654                                 fwd_r_add_policytarget(x, FWD_P_ACCEPT);        /* -j handle_... */
 655                                 fwd_r_add_comment(x, "forward", z, n, n2);      /* -m comment ... */
 656                                 fwd_xt_exec_rule(x, "forwardings");                     /* -A forwardings */
 657                         }
 658                 }
 659         }
 660
 661         /* Build DNAT rules */
 662         for( e = z->redirects; e && (r = &e->section.redirect); e = e->next )
 663         {
 664                 printf("\n# Net %s (%s) - redirect Z:%s N:%s I:%s\n",
 665                         n->name, n->ifname, z->name, n->name, n->ifname);
 666
 667                 /* DNAT */
 668                 if( (x = fwd_xt_init_rule(h_nat)) != NULL )
 669                 {
 670                         fwd_xt_parse_in(x, n, 0);                                       /* -i ... */
 671                         fwd_xt_parse_src(x, r->src_ip, 0);                      /* -s ... */
 672                         fwd_xt_parse_dest(x, &a->ipaddr, 0);            /* -d ... */
 673                         fwd_xt_parse_proto(x, r->proto, 0);                     /* -p ... */
 674                         fwd_r_add_sport(x, r->src_port);                        /* --sport ... */
 675                         fwd_r_add_dport(x, r->src_dport);                       /* --dport ... */
 676                         fwd_r_add_srcmac(x, r->src_mac);                        /* -m mac --mac-source ... */
 677                         fwd_r_add_dnattarget(x, r->dest_ip, r->dest_port);      /* -j DNAT ... */
 678                         fwd_r_add_comment(x, "redir", z, n, NULL);      /* -m comment ... */
 679                         fwd_xt_exec_rule(x, "redirects");                       /* -A redirects */
 680                 }
 681
 682                 /* Forward */
 683                 if( (x = fwd_xt_init_rule(h_filter)) != NULL )
 684                 {
 685                         fwd_xt_parse_in(x, n, 0);                                       /* -i ... */
 686                         fwd_xt_parse_src(x, r->src_ip, 0);                      /* -s ... */
 687                         fwd_xt_parse_dest(x, r->dest_ip, 0);            /* -d ... */
 688                         fwd_xt_parse_proto(x, r->proto, 0);                     /* -p ... */
 689                         fwd_r_add_srcmac(x, r->src_mac);                        /* -m mac --mac-source ... */
 690                         fwd_r_add_sport(x, r->src_port);                        /* --sport ... */
 691                         fwd_r_add_dport(x, r->dest_port);                       /* --dport ... */
 692                         fwd_r_add_policytarget(x, FWD_P_ACCEPT);        /* -j handle_accept */
 693                         fwd_r_add_comment(x, "redir", z, n, NULL);      /* -m comment ... */
 694                         fwd_xt_exec_rule(x, "redirects");                       /* -A redirects */
 695                 }
 696
 697                 /* Add loopback rule if neither src_ip nor src_mac are defined */
 698                 if( !r->src_ip && !r->src_mac )
 699                 {
 700                         if( (x = fwd_xt_init_rule(h_nat)) != NULL )
 701                         {
 702                                 fwd_xt_parse_in(x, n, 1);                                       /* -i ! ... */
 703                                 fwd_xt_parse_dest(x, r->dest_ip, 0);            /* -d ... */
 704                                 fwd_xt_parse_proto(x, r->proto, 0);                     /* -p ... */
 705                                 fwd_r_add_sport(x, r->src_port);                        /* --sport ... */
 706                                 fwd_r_add_dport(x, r->src_dport);                       /* --dport ... */
 707                                 fwd_xt_get_target(x, "MASQUERADE");                     /* -j MASQUERADE */
 708                                 fwd_r_add_comment(x, "redir", z, n, NULL);      /* -m comment ... */
 709                                 fwd_xt_exec_rule(x, "loopback");                        /* -A loopback */
 710                         }
 711                 }
 712         }
 713
 714         /* Build rules */
 715         for( e = z->rules; e && (c = &e->section.rule); e = e->next )
 716         {
 717                 /* Has destination, add forward rule for each network in target zone */
 718                 if( c->dest )
 719                 {
 720                         for( n2 = c->dest->networks; n2; n2 = n2->next )
 721                         {
 722                                 printf("\n# Net %s (%s) - rule+dest"
 723                                " Z:%s N:%s I:%s -> Z:%s N:%s I:%s\n",
 724                                         n->name, n->ifname, z->name, n->name, n->ifname,
 725                                         f->dest->name, n2->name, n2->ifname);
 726
 727                                 if( (x = fwd_xt_init_rule(h_filter)) != NULL )
 728                                 {
 729                                         fwd_xt_parse_in(x, n, 0);                               /* -i ... */
 730                                         fwd_xt_parse_out(x, n2, 0);                             /* -o ... */
 731                                         fwd_xt_parse_src(x, c->src_ip, 0);              /* -s ... */
 732                                         fwd_xt_parse_dest(x, c->dest_ip, 0);    /* -d ... */
 733                                         fwd_xt_parse_proto(x, c->proto, 0);             /* -p ... */
 734                                         fwd_r_add_icmptype(x, c->icmp_type);    /* --icmp-type ... */
 735                                         fwd_r_add_srcmac(x, c->src_mac);                /* --mac-source ... */
 736                                         fwd_r_add_sport(x, c->src_port);                /* --sport ... */
 737                                         fwd_r_add_dport(x, c->dest_port);               /* --dport ... */
 738                                         fwd_r_add_policytarget(x, c->target);   /* -j handle_... */
 739                                         fwd_r_add_comment(x, "rule", z, n, n2); /* -m comment ... */
 740                                         fwd_xt_exec_rule(x, "rules");                   /* -A rules */
 741                                 }
 742                         }
 743                 }
 744
 745                 /* No destination specified, treat it as input rule */
 746                 else
 747                 {
 748                         printf("\n# Net %s (%s) - rule Z:%s N:%s I:%s\n",
 749                                 n->name, n->ifname, z->name, n->name, n->ifname);
 750
 751                         if( (x = fwd_xt_init_rule(h_filter)) != NULL )
 752                         {
 753                                 fwd_xt_parse_in(x, n, 0);                                       /* -i ... */
 754                                 fwd_xt_parse_src(x, c->src_ip, 0);                      /* -s ... */
 755                                 fwd_xt_parse_dest(x, c->dest_ip, 0);            /* -d ... */
 756                                 fwd_xt_parse_proto(x, c->proto, 0);                     /* -p ... */
 757                                 fwd_r_add_icmptype(x, c->icmp_type);            /* --icmp-type ... */
 758                                 fwd_r_add_srcmac(x, c->src_mac);                        /* --mac-source ... */
 759                                 fwd_r_add_sport(x, c->src_port);                        /* --sport ... */
 760                                 fwd_r_add_dport(x, c->dest_port);                       /* --dport ... */
 761                                 fwd_r_add_policytarget(x, c->target);           /* -j handle_... */
 762                                 fwd_r_add_comment(x, "rule", z, n, NULL);       /* -m comment ... */
 763                                 fwd_xt_exec_rule(x, "rules");                           /* -A rules */
 764                         }
 765                 }
 766         }
 767
 768         if( !iptc_commit(h_nat) )
 769                 fwd_fatal("Cannot commit nat table: %s", iptc_strerror(errno));
 770
 771         if( !iptc_commit(h_filter) )
 772                 fwd_fatal("Cannot commit filter table: %s", iptc_strerror(errno));
 773
 774         iptc_free(h_nat);
 775         iptc_free(h_filter);
 776 }
 777