src/iptables.c

   1 /*
   2  *
   3  *  Connection Manager
   4  *
   5  *  Copyright (C) 2007-2012  Intel Corporation. All rights reserved.
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License version 2 as
   9  *  published by the Free Software Foundation.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <getopt.h>
  27 #include <stdlib.h>
  28 #include <stdio.h>
  29 #include <string.h>
  30 #include <unistd.h>
  31 #include <sys/errno.h>
  32 #include <sys/socket.h>
  33 #include <xtables.h>
  34
  35 #include <linux/netfilter_ipv4/ip_tables.h>
  36
  37 #include "connman.h"
  38
  39 void flush_table(const char *name);
  40
  41 /*
  42  * Some comments on how the iptables API works (some of them from the
  43  * source code from iptables and the kernel):
  44  *
  45  * - valid_hooks: bit indicates valid IDs for hook_entry
  46  * - hook_entry[ID] offset to the chain start
  47  * - overflows should be end of entry chains, and uncodintional policy nodes.
  48  * - policy entry: last entry in a chain
  49  * - user chain: end of last builtin + policy entry
  50  * - final entry must be error node
  51  * - Underflows must be unconditional and use the STANDARD target with
  52  *   ACCEPT/DROP
  53  * - IPT_SO_GET_INFO and IPT_SO_GET_ENTRIES are used to read a table
  54  * - IPT_SO_GET_INFO: struct ipt_getinfo (note the lack of table content)
  55  * - IPT_SO_GET_ENTRIES: struct ipt_get_entries (contains only parts of the
  56  *   table header/meta info. The table is appended after the header. The entries
  57  *   are of the type struct ipt_entry.
  58  * - After the ipt_entry the matches are appended. After the matches
  59  *   the target is appended.
  60  * - ipt_entry->target_offset =  Size of ipt_entry + matches
  61  * - ipt_entry->next_offset =  Size of ipt_entry + matches + target
  62  * - IPT_SO_SET_REPLACE is used to write a table (contains the complete
  63  * - hook_entry and overflow mark the begining and the end of a chain, e.g
  64  *     entry hook: pre/in/fwd/out/post -1/0/352/504/-1
  65  *     underflow:  pre/in/fwd/out/post -1/200/352/904/-1
  66  *   means that INPUT starts at offset 0 and ends at 200 (the start offset to
  67  *   the last element). FORWARD has one entry starting/ending at 352. The entry
  68  *   has a size of 152. 352 + 152 = 504 which is the start of the OUTPUT chain
  69  *   which then ends at 904. PREROUTING and POSTROUTING are invalid hooks in
  70  *   the filter table.
  71  * - 'iptables -t filter -A INPUT -m mark --mark 999 -j LOG'
  72  *   writing that table looks like this:
  73  *
  74  *   filter valid_hooks 0x0000000e  num_entries 5  size 856
  75  *   entry hook: pre/in/fwd/out/post -1/0/376/528/-1
  76  *   underflow:  pre/in/fwd/out/post -1/224/376/528/-1
  77  *   entry 0x699d30  offset 0  size 224
  78  *     RULE  match 0x699da0  target 0x699dd0
  79  *             match  mark match 0x3e7
  80  *             target  LOG flags 0 level 4
  81  *             src 0.0.0.0/0.0.0.0
  82  *             dst 0.0.0.0/0.0.0.0
  83  *   entry 0x699e10  offset 224  size 152
  84  *     RULE  match 0x699e80  target 0x699e80
  85  *             target ACCEPT
  86  *             src 0.0.0.0/0.0.0.0
  87  *             dst 0.0.0.0/0.0.0.0
  88  *   entry 0x699ea8  offset 376  size 152
  89  *     RULE  match 0x699f18  target 0x699f18
  90  *             target ACCEPT
  91  *             src 0.0.0.0/0.0.0.0
  92  *             dst 0.0.0.0/0.0.0.0
  93  *   entry 0x699f40  offset 528  size 152
  94  *     RULE  match 0x699fb0  target 0x699fb0
  95  *             target ACCEPT
  96  *             src 0.0.0.0/0.0.0.0
  97  *             dst 0.0.0.0/0.0.0.0
  98  *   entry 0x699fd8  offset 680  size 176
  99  *     USER CHAIN (ERROR)  match 0x69a048  target 0x69a048
 100  *
 101  *   Reading the filter table looks like this:
 102  *
 103  *   filter valid_hooks 0x0000000e  num_entries 5  size 856
 104  *   entry hook: pre/in/fwd/out/post -1/0/376/528/-1
 105  *   underflow:  pre/in/fwd/out/post -1/224/376/528/-1
 106  *   entry 0x25fec28  offset 0  size 224
 107  *     CHAIN (INPUT)  match 0x25fec98  target 0x25fecc8
 108  *             match  mark match 0x3e7
 109  *             target  LOG flags 0 level 4
 110  *             src 0.0.0.0/0.0.0.0
 111  *             dst 0.0.0.0/0.0.0.0
 112  *   entry 0x25fed08  offset 224  size 152
 113  *     RULE  match 0x25fed78  target 0x25fed78
 114  *             target ACCEPT
 115  *             src 0.0.0.0/0.0.0.0
 116  *             dst 0.0.0.0/0.0.0.0
 117  *   entry 0x25feda0  offset 376  size 152
 118  *     CHAIN (FORWARD)  match 0x25fee10  target 0x25fee10
 119  *             target ACCEPT
 120  *             src 0.0.0.0/0.0.0.0
 121  *             dst 0.0.0.0/0.0.0.0
 122  *   entry 0x25fee38  offset 528  size 152
 123  *     CHAIN (OUTPUT)  match 0x25feea8  target 0x25feea8
 124  *             target ACCEPT
 125  *             src 0.0.0.0/0.0.0.0
 126  *             dst 0.0.0.0/0.0.0.0
 127  *   entry 0x25feed0  offset 680  size 176
 128  *     End of CHAIN
 129  */
 130
 131 static const char *hooknames[] = {
 132         [NF_IP_PRE_ROUTING]     = "PREROUTING",
 133         [NF_IP_LOCAL_IN]        = "INPUT",
 134         [NF_IP_FORWARD]         = "FORWARD",
 135         [NF_IP_LOCAL_OUT]       = "OUTPUT",
 136         [NF_IP_POST_ROUTING]    = "POSTROUTING",
 137 };
 138
 139 #define LABEL_ACCEPT  "ACCEPT"
 140 #define LABEL_DROP    "DROP"
 141 #define LABEL_QUEUE   "QUEUE"
 142 #define LABEL_RETURN  "RETURN"
 143
 144 #define XT_OPTION_OFFSET_SCALE 256
 145
 146 #define MIN_ALIGN (__alignof__(struct ipt_entry))
 147
 148 #define ALIGN(s) (((s) + ((MIN_ALIGN)-1)) & ~((MIN_ALIGN)-1))
 149
 150 struct error_target {
 151         struct xt_entry_target t;
 152         char error[IPT_TABLE_MAXNAMELEN];
 153 };
 154
 155 struct connman_iptables_entry {
 156         int offset;
 157         int builtin;
 158
 159         struct ipt_entry *entry;
 160 };
 161
 162 struct connman_iptables {
 163         int ipt_sock;
 164
 165         struct ipt_getinfo *info;
 166         struct ipt_get_entries *blob_entries;
 167
 168         unsigned int num_entries;
 169         unsigned int old_entries;
 170         unsigned int size;
 171
 172         unsigned int underflow[NF_INET_NUMHOOKS];
 173         unsigned int hook_entry[NF_INET_NUMHOOKS];
 174
 175         GList *entries;
 176 };
 177
 178 static GHashTable *table_hash = NULL;
 179 static gboolean debug_enabled = FALSE;
 180
 181 typedef int (*iterate_entries_cb_t)(struct ipt_entry *entry, int builtin,
 182                                         unsigned int hook,size_t size,
 183                                         unsigned int offset, void *user_data);
 184
 185 static unsigned int next_hook_entry_index(unsigned int *valid_hooks)
 186 {
 187         unsigned int h;
 188
 189         if (*valid_hooks == 0)
 190                 return NF_INET_NUMHOOKS;
 191
 192         h = __builtin_ffs(*valid_hooks) - 1;
 193         *valid_hooks ^= (1 << h);
 194
 195         return h;
 196 }
 197
 198 static int iterate_entries(struct ipt_entry *entries,
 199                                 unsigned int valid_hooks,
 200                                 unsigned int *hook_entry,
 201                                 unsigned int *underflow,
 202                                 size_t size, iterate_entries_cb_t cb,
 203                                 void *user_data)
 204 {
 205         unsigned int offset, h, hook;
 206         int builtin, err;
 207         struct ipt_entry *entry;
 208
 209         h = next_hook_entry_index(&valid_hooks);
 210         hook = h;
 211
 212         for (offset = 0, entry = entries; offset < size;
 213                         offset += entry->next_offset) {
 214                 builtin = -1;
 215                 entry = (void *)entries + offset;
 216
 217                 /*
 218                  * Updating builtin, hook and h is very tricky.
 219                  * The rules are:
 220                  * - builtin is only set to the current hook number
 221                  *   if the current entry is the hook entry (aka chain
 222                  *   head). And only for builtin chains, never for
 223                  *   the user chains.
 224                  * - hook is the current hook number. If we
 225                  *   look at user chains it needs to be NF_INET_NETNUMHOOKS.
 226                  * - h is the next hook entry. Thous we need to be carefully
 227                  *   not to access the table when h is NF_INET_NETNUMHOOKS.
 228                  */
 229                 if (h < NF_INET_NUMHOOKS && hook_entry[h] == offset) {
 230                         builtin = h;
 231                         hook = h;
 232                 }
 233
 234                 if (h == NF_INET_NUMHOOKS)
 235                         hook = h;
 236
 237                 if (h < NF_INET_NUMHOOKS && underflow[h] <= offset) {
 238                         h = next_hook_entry_index(&valid_hooks);
 239                 }
 240
 241                 err = cb(entry, builtin, hook, size, offset, user_data);
 242                 if (err < 0)
 243                         return err;
 244         }
 245
 246         return 0;
 247 }
 248
 249 static int print_entry(struct ipt_entry *entry, int builtin, unsigned int hook,
 250                                         size_t size, unsigned int offset,
 251                                         void *user_data)
 252 {
 253         iterate_entries_cb_t cb = user_data;
 254
 255         DBG("entry %p  hook %d  offset %d  size %d", entry, hook,
 256                         offset, entry->next_offset);
 257
 258         return cb(entry, builtin, hook, size, offset, NULL);
 259 }
 260
 261 static int target_to_verdict(const char *target_name)
 262 {
 263         if (!strcmp(target_name, LABEL_ACCEPT))
 264                 return -NF_ACCEPT - 1;
 265
 266         if (!strcmp(target_name, LABEL_DROP))
 267                 return -NF_DROP - 1;
 268
 269         if (!strcmp(target_name, LABEL_QUEUE))
 270                 return -NF_QUEUE - 1;
 271
 272         if (!strcmp(target_name, LABEL_RETURN))
 273                 return XT_RETURN;
 274
 275         return 0;
 276 }
 277
 278 static gboolean is_builtin_target(const char *target_name)
 279 {
 280         if (!strcmp(target_name, LABEL_ACCEPT) ||
 281                 !strcmp(target_name, LABEL_DROP) ||
 282                 !strcmp(target_name, LABEL_QUEUE) ||
 283                 !strcmp(target_name, LABEL_RETURN))
 284                 return TRUE;
 285
 286         return FALSE;
 287 }
 288
 289 static gboolean is_jump(struct connman_iptables_entry *e)
 290 {
 291         struct xt_entry_target *target;
 292
 293         target = ipt_get_target(e->entry);
 294
 295         if (!strcmp(target->u.user.name, IPT_STANDARD_TARGET)) {
 296                 struct xt_standard_target *t;
 297
 298                 t = (struct xt_standard_target *)target;
 299
 300                 switch (t->verdict) {
 301                 case XT_RETURN:
 302                 case -NF_ACCEPT - 1:
 303                 case -NF_DROP - 1:
 304                 case -NF_QUEUE - 1:
 305                 case -NF_STOP - 1:
 306                         return false;
 307
 308                 default:
 309                         return true;
 310                 }
 311         }
 312
 313         return false;
 314 }
 315
 316 static gboolean is_fallthrough(struct connman_iptables_entry *e)
 317 {
 318         struct xt_entry_target *target;
 319
 320         target = ipt_get_target(e->entry);
 321         if (!g_strcmp0(target->u.user.name, IPT_STANDARD_TARGET)) {
 322                 struct xt_standard_target *t;
 323
 324                 t = (struct xt_standard_target *)target;
 325                 if (t->verdict == 0)
 326                         return true;
 327         }
 328         return false;
 329 }
 330
 331 static gboolean is_chain(struct connman_iptables *table,
 332                                 struct connman_iptables_entry *e)
 333 {
 334         struct ipt_entry *entry;
 335         struct xt_entry_target *target;
 336
 337         entry = e->entry;
 338         if (e->builtin >= 0)
 339                 return TRUE;
 340
 341         target = ipt_get_target(entry);
 342         if (!strcmp(target->u.user.name, IPT_ERROR_TARGET))
 343                 return TRUE;
 344
 345         return FALSE;
 346 }
 347
 348 static GList *find_chain_head(struct connman_iptables *table,
 349                                 const char *chain_name)
 350 {
 351         GList *list;
 352         struct connman_iptables_entry *head;
 353         struct ipt_entry *entry;
 354         struct xt_entry_target *target;
 355         int builtin;
 356
 357         for (list = table->entries; list; list = list->next) {
 358                 head = list->data;
 359                 entry = head->entry;
 360
 361                 /* Buit-in chain */
 362                 builtin = head->builtin;
 363                 if (builtin >= 0 && !strcmp(hooknames[builtin], chain_name))
 364                         break;
 365
 366                 /* User defined chain */
 367                 target = ipt_get_target(entry);
 368                 if (!strcmp(target->u.user.name, IPT_ERROR_TARGET) &&
 369                     !strcmp((char *)target->data, chain_name))
 370                         break;
 371         }
 372
 373         return list;
 374 }
 375
 376 static GList *find_chain_tail(struct connman_iptables *table,
 377                                 const char *chain_name)
 378 {
 379         struct connman_iptables_entry *tail;
 380         GList *chain_head, *list;
 381
 382         chain_head = find_chain_head(table, chain_name);
 383         if (chain_head == NULL)
 384                 return NULL;
 385
 386         /* Then we look for the next chain */
 387         for (list = chain_head->next; list; list = list->next) {
 388                 tail = list->data;
 389
 390                 if (is_chain(table, tail))
 391                         return list;
 392         }
 393
 394         /* Nothing found, we return the table end */
 395         return g_list_last(table->entries);
 396 }
 397
 398
 399 static void update_offsets(struct connman_iptables *table)
 400 {
 401         GList *list, *prev;
 402         struct connman_iptables_entry *entry, *prev_entry;
 403
 404         for (list = table->entries; list; list = list->next) {
 405                 entry = list->data;
 406
 407                 if (list == table->entries) {
 408                         entry->offset = 0;
 409
 410                         continue;
 411                 }
 412
 413                 prev = list->prev;
 414                 prev_entry = prev->data;
 415
 416                 entry->offset = prev_entry->offset +
 417                                         prev_entry->entry->next_offset;
 418         }
 419 }
 420
 421 static void update_targets_reference(struct connman_iptables *table,
 422                                 struct connman_iptables_entry *entry_before,
 423                                 struct connman_iptables_entry *modified_entry,
 424                                 gboolean is_removing)
 425 {
 426         struct connman_iptables_entry *tmp;
 427         struct xt_standard_target *t;
 428         GList *list;
 429         int offset;
 430
 431         offset = modified_entry->entry->next_offset;
 432
 433         for (list = table->entries; list; list = list->next) {
 434                 tmp = list->data;
 435
 436                 if (!is_jump(tmp))
 437                         continue;
 438
 439                 t = (struct xt_standard_target *)ipt_get_target(tmp->entry);
 440
 441                 if (is_removing == TRUE) {
 442                         if (t->verdict >= entry_before->offset)
 443                                 t->verdict -= offset;
 444                 } else {
 445                         if (t->verdict > entry_before->offset)
 446                                 t->verdict += offset;
 447                 }
 448         }
 449
 450         if (is_fallthrough(modified_entry)) {
 451                 t = (struct xt_standard_target *) ipt_get_target(modified_entry->entry);
 452
 453                 t->verdict = entry_before->offset +
 454                         modified_entry->entry->target_offset +
 455                         ALIGN(sizeof(struct xt_standard_target));
 456                 t->target.u.target_size =
 457                         ALIGN(sizeof(struct xt_standard_target));
 458         }
 459 }
 460
 461 static int iptables_add_entry(struct connman_iptables *table,
 462                                 struct ipt_entry *entry, GList *before,
 463                                         int builtin)
 464 {
 465         struct connman_iptables_entry *e, *entry_before;
 466
 467         if (table == NULL)
 468                 return -1;
 469
 470         e = g_try_malloc0(sizeof(struct connman_iptables_entry));
 471         if (e == NULL)
 472                 return -1;
 473
 474         e->entry = entry;
 475         e->builtin = builtin;
 476
 477         table->entries = g_list_insert_before(table->entries, before, e);
 478         table->num_entries++;
 479         table->size += entry->next_offset;
 480
 481         if (before == NULL) {
 482                 e->offset = table->size - entry->next_offset;
 483
 484                 return 0;
 485         }
 486
 487         entry_before = before->data;
 488
 489         /*
 490          * We've just appended/insterted a new entry. All references
 491          * should be bumped accordingly.
 492          */
 493         update_targets_reference(table, entry_before, e, FALSE);
 494
 495         update_offsets(table);
 496
 497         return 0;
 498 }
 499
 500 static int remove_table_entry(struct connman_iptables *table,
 501                                 struct connman_iptables_entry *entry)
 502 {
 503         int removed = 0;
 504
 505         table->num_entries--;
 506         table->size -= entry->entry->next_offset;
 507         removed = entry->entry->next_offset;
 508
 509         table->entries = g_list_remove(table->entries, entry);
 510
 511         g_free(entry->entry);
 512         g_free(entry);
 513
 514         return removed;
 515 }
 516
 517 static int iptables_flush_chain(struct connman_iptables *table,
 518                                                 const char *name)
 519 {
 520         GList *chain_head, *chain_tail, *list, *next;
 521         struct connman_iptables_entry *entry;
 522         int builtin, removed = 0;
 523
 524         chain_head = find_chain_head(table, name);
 525         if (chain_head == NULL)
 526                 return -EINVAL;
 527
 528         chain_tail = find_chain_tail(table, name);
 529         if (chain_tail == NULL)
 530                 return -EINVAL;
 531
 532         entry = chain_head->data;
 533         builtin = entry->builtin;
 534
 535         if (builtin >= 0)
 536                 list = chain_head;
 537         else
 538                 list = chain_head->next;
 539
 540         if (list == chain_tail->prev)
 541                 return 0;
 542
 543         while (list != chain_tail->prev) {
 544                 entry = list->data;
 545                 next = g_list_next(list);
 546
 547                 removed += remove_table_entry(table, entry);
 548
 549                 list = next;
 550         }
 551
 552         if (builtin >= 0) {
 553                 struct connman_iptables_entry *e;
 554
 555                 entry = list->data;
 556
 557                 entry->builtin = builtin;
 558
 559                 table->underflow[builtin] -= removed;
 560
 561                 for (list = chain_tail; list; list = list->next) {
 562                         e = list->data;
 563
 564                         builtin = e->builtin;
 565                         if (builtin < 0)
 566                                 continue;
 567
 568                         table->hook_entry[builtin] -= removed;
 569                         table->underflow[builtin] -= removed;
 570                 }
 571         }
 572
 573         update_offsets(table);
 574
 575         return 0;
 576 }
 577
 578 static int iptables_add_chain(struct connman_iptables *table,
 579                                 const char *name)
 580 {
 581         GList *last;
 582         struct ipt_entry *entry_head;
 583         struct ipt_entry *entry_return;
 584         struct error_target *error;
 585         struct ipt_standard_target *standard;
 586         u_int16_t entry_head_size, entry_return_size;
 587
 588         last = g_list_last(table->entries);
 589
 590         /*
 591          * An empty chain is composed of:
 592          * - A head entry, with no match and an error target.
 593          *   The error target data is the chain name.
 594          * - A tail entry, with no match and a standard target.
 595          *   The standard target verdict is XT_RETURN (return to the
 596          *   caller).
 597          */
 598
 599         /* head entry */
 600         entry_head_size = sizeof(struct ipt_entry) +
 601                                 sizeof(struct error_target);
 602         entry_head = g_try_malloc0(entry_head_size);
 603         if (entry_head == NULL)
 604                 goto err_head;
 605
 606         memset(entry_head, 0, entry_head_size);
 607
 608         entry_head->target_offset = sizeof(struct ipt_entry);
 609         entry_head->next_offset = entry_head_size;
 610
 611         error = (struct error_target *) entry_head->elems;
 612         strcpy(error->t.u.user.name, IPT_ERROR_TARGET);
 613         error->t.u.user.target_size = ALIGN(sizeof(struct error_target));
 614         strcpy(error->error, name);
 615
 616         if (iptables_add_entry(table, entry_head, last, -1) < 0)
 617                 goto err_head;
 618
 619         /* tail entry */
 620         entry_return_size = sizeof(struct ipt_entry) +
 621                                 sizeof(struct ipt_standard_target);
 622         entry_return = g_try_malloc0(entry_return_size);
 623         if (entry_return == NULL)
 624                 goto err;
 625
 626         memset(entry_return, 0, entry_return_size);
 627
 628         entry_return->target_offset = sizeof(struct ipt_entry);
 629         entry_return->next_offset = entry_return_size;
 630
 631         standard = (struct ipt_standard_target *) entry_return->elems;
 632         standard->target.u.user.target_size =
 633                                 ALIGN(sizeof(struct ipt_standard_target));
 634         standard->verdict = XT_RETURN;
 635
 636         if (iptables_add_entry(table, entry_return, last, -1) < 0)
 637                 goto err;
 638
 639         return 0;
 640
 641 err:
 642         g_free(entry_return);
 643 err_head:
 644         g_free(entry_head);
 645
 646         return -ENOMEM;
 647 }
 648
 649 static int iptables_delete_chain(struct connman_iptables *table,
 650                                         const char *name)
 651 {
 652         struct connman_iptables_entry *entry;
 653         GList *chain_head, *chain_tail;
 654
 655         chain_head = find_chain_head(table, name);
 656         if (chain_head == NULL)
 657                 return -EINVAL;
 658
 659         entry = chain_head->data;
 660
 661         /* We cannot remove builtin chain */
 662         if (entry->builtin >= 0)
 663                 return -EINVAL;
 664
 665         chain_tail = find_chain_tail(table, name);
 666         if (chain_tail == NULL)
 667                 return -EINVAL;
 668
 669         /* Chain must be flushed */
 670         if (chain_head->next != chain_tail->prev)
 671                 return -EINVAL;
 672
 673         remove_table_entry(table, entry);
 674
 675         entry = chain_tail->prev->data;
 676         remove_table_entry(table, entry);
 677
 678         update_offsets(table);
 679
 680         return 0;
 681 }
 682
 683 static struct ipt_entry *new_rule(struct ipt_ip *ip,
 684                 const char *target_name, struct xtables_target *xt_t,
 685                 struct xtables_rule_match *xt_rm)
 686 {
 687         struct xtables_rule_match *tmp_xt_rm;
 688         struct ipt_entry *new_entry;
 689         size_t match_size, target_size;
 690
 691         match_size = 0;
 692         for (tmp_xt_rm = xt_rm; tmp_xt_rm != NULL; tmp_xt_rm = tmp_xt_rm->next)
 693                 match_size += tmp_xt_rm->match->m->u.match_size;
 694
 695         if (xt_t)
 696                 target_size = ALIGN(xt_t->t->u.target_size);
 697         else
 698                 target_size = ALIGN(sizeof(struct xt_standard_target));
 699
 700         new_entry = g_try_malloc0(sizeof(struct ipt_entry) + target_size +
 701                                                                 match_size);
 702         if (new_entry == NULL)
 703                 return NULL;
 704
 705         memcpy(&new_entry->ip, ip, sizeof(struct ipt_ip));
 706
 707         new_entry->target_offset = sizeof(struct ipt_entry) + match_size;
 708         new_entry->next_offset = sizeof(struct ipt_entry) + target_size +
 709                                                                 match_size;
 710
 711         match_size = 0;
 712         for (tmp_xt_rm = xt_rm; tmp_xt_rm != NULL;
 713                                 tmp_xt_rm = tmp_xt_rm->next) {
 714                 memcpy(new_entry->elems + match_size, tmp_xt_rm->match->m,
 715                                         tmp_xt_rm->match->m->u.match_size);
 716                 match_size += tmp_xt_rm->match->m->u.match_size;
 717         }
 718
 719         if (xt_t) {
 720                 struct xt_entry_target *entry_target;
 721
 722                 entry_target = ipt_get_target(new_entry);
 723                 memcpy(entry_target, xt_t->t, target_size);
 724         }
 725
 726         return new_entry;
 727 }
 728
 729 static void update_hooks(struct connman_iptables *table, GList *chain_head,
 730                                 struct ipt_entry *entry)
 731 {
 732         GList *list;
 733         struct connman_iptables_entry *head, *e;
 734         int builtin;
 735
 736         if (chain_head == NULL)
 737                 return;
 738
 739         head = chain_head->data;
 740
 741         builtin = head->builtin;
 742         if (builtin < 0)
 743                 return;
 744
 745         table->underflow[builtin] += entry->next_offset;
 746
 747         for (list = chain_head->next; list; list = list->next) {
 748                 e = list->data;
 749
 750                 builtin = e->builtin;
 751                 if (builtin < 0)
 752                         continue;
 753
 754                 table->hook_entry[builtin] += entry->next_offset;
 755                 table->underflow[builtin] += entry->next_offset;
 756         }
 757 }
 758
 759 static struct ipt_entry *prepare_rule_inclusion(struct connman_iptables *table,
 760                                 struct ipt_ip *ip, const char *chain_name,
 761                                 const char *target_name,
 762                                 struct xtables_target *xt_t,
 763                                 int *builtin, struct xtables_rule_match *xt_rm)
 764 {
 765         GList *chain_tail, *chain_head;
 766         struct ipt_entry *new_entry;
 767         struct connman_iptables_entry *head;
 768
 769         chain_head = find_chain_head(table, chain_name);
 770         if (chain_head == NULL)
 771                 return NULL;
 772
 773         chain_tail = find_chain_tail(table, chain_name);
 774         if (chain_tail == NULL)
 775                 return NULL;
 776
 777         new_entry = new_rule(ip, target_name, xt_t, xt_rm);
 778         if (new_entry == NULL)
 779                 return NULL;
 780
 781         update_hooks(table, chain_head, new_entry);
 782
 783         /*
 784          * If the chain is builtin, and does not have any rule,
 785          * then the one that we're inserting is becoming the head
 786          * and thus needs the builtin flag.
 787          */
 788         head = chain_head->data;
 789         if (head->builtin < 0)
 790                 *builtin = -1;
 791         else if (chain_head == chain_tail->prev) {
 792                 *builtin = head->builtin;
 793                 head->builtin = -1;
 794         }
 795
 796         return new_entry;
 797 }
 798
 799 static int iptables_append_rule(struct connman_iptables *table,
 800                                 struct ipt_ip *ip, const char *chain_name,
 801                                 const char *target_name,
 802                                 struct xtables_target *xt_t,
 803                                 struct xtables_rule_match *xt_rm)
 804 {
 805         struct ipt_entry *new_entry;
 806         int builtin = -1, ret;
 807         GList *chain_tail;
 808
 809         chain_tail = find_chain_tail(table, chain_name);
 810         if (chain_tail == NULL)
 811                 return -EINVAL;
 812
 813         new_entry = prepare_rule_inclusion(table, ip, chain_name,
 814                                         target_name, xt_t, &builtin, xt_rm);
 815         if (new_entry == NULL)
 816                 return -EINVAL;
 817
 818         ret = iptables_add_entry(table, new_entry, chain_tail->prev, builtin);
 819         if (ret < 0)
 820                 g_free(new_entry);
 821
 822         return ret;
 823 }
 824
 825 static gboolean is_same_ipt_entry(struct ipt_entry *i_e1,
 826                                         struct ipt_entry *i_e2)
 827 {
 828         if (memcmp(&i_e1->ip, &i_e2->ip, sizeof(struct ipt_ip)) != 0)
 829                 return FALSE;
 830
 831         if (i_e1->target_offset != i_e2->target_offset)
 832                 return FALSE;
 833
 834         if (i_e1->next_offset != i_e2->next_offset)
 835                 return FALSE;
 836
 837         return TRUE;
 838 }
 839
 840 static gboolean is_same_target(struct xt_entry_target *xt_e_t1,
 841                                         struct xt_entry_target *xt_e_t2)
 842 {
 843         unsigned int i;
 844
 845         if (xt_e_t1 == NULL || xt_e_t2 == NULL)
 846                 return FALSE;
 847
 848         if (strcmp(xt_e_t1->u.user.name, "") == 0 &&
 849                         strcmp(xt_e_t2->u.user.name, "") == 0) {
 850                 /* fallthrough */
 851                 return TRUE;
 852         } else if (strcmp(xt_e_t1->u.user.name, IPT_STANDARD_TARGET) == 0) {
 853                 struct xt_standard_target *xt_s_t1;
 854                 struct xt_standard_target *xt_s_t2;
 855
 856                 xt_s_t1 = (struct xt_standard_target *) xt_e_t1;
 857                 xt_s_t2 = (struct xt_standard_target *) xt_e_t2;
 858
 859                 if (xt_s_t1->verdict != xt_s_t2->verdict)
 860                         return FALSE;
 861         } else {
 862                 if (xt_e_t1->u.target_size != xt_e_t2->u.target_size)
 863                         return FALSE;
 864
 865                 if (strcmp(xt_e_t1->u.user.name, xt_e_t2->u.user.name) != 0)
 866                         return FALSE;
 867
 868                 for (i = 0; i < xt_e_t1->u.target_size -
 869                                 sizeof(struct xt_standard_target); i++) {
 870                         if ((xt_e_t1->data[i] ^ xt_e_t2->data[i]) != 0)
 871                                 return FALSE;
 872                 }
 873         }
 874
 875         return TRUE;
 876 }
 877
 878 static gboolean is_same_match(struct xt_entry_match *xt_e_m1,
 879                                 struct xt_entry_match *xt_e_m2)
 880 {
 881         unsigned int i;
 882
 883         if (xt_e_m1 == NULL || xt_e_m2 == NULL)
 884                 return FALSE;
 885
 886         if (xt_e_m1->u.match_size != xt_e_m2->u.match_size)
 887                 return FALSE;
 888
 889         if (xt_e_m1->u.user.revision != xt_e_m2->u.user.revision)
 890                 return FALSE;
 891
 892         if (strcmp(xt_e_m1->u.user.name, xt_e_m2->u.user.name) != 0)
 893                 return FALSE;
 894
 895         for (i = 0; i < xt_e_m1->u.match_size - sizeof(struct xt_entry_match);
 896                         i++) {
 897                 if ((xt_e_m1->data[i] ^ xt_e_m2->data[i]) != 0)
 898                         return FALSE;
 899         }
 900
 901         return TRUE;
 902 }
 903
 904 static GList *find_existing_rule(struct connman_iptables *table,
 905                                 struct ipt_ip *ip, const char *chain_name,
 906                                 const char *target_name,
 907                                 struct xtables_target *xt_t,
 908                                 struct xtables_match *xt_m,
 909                                 struct xtables_rule_match *xt_rm)
 910 {
 911         GList *chain_tail, *chain_head, *list;
 912         struct xt_entry_target *xt_e_t = NULL;
 913         struct xt_entry_match *xt_e_m = NULL;
 914         struct connman_iptables_entry *entry;
 915         struct ipt_entry *entry_test;
 916         int builtin;
 917
 918         chain_head = find_chain_head(table, chain_name);
 919         if (chain_head == NULL)
 920                 return NULL;
 921
 922         chain_tail = find_chain_tail(table, chain_name);
 923         if (chain_tail == NULL)
 924                 return NULL;
 925
 926         if (!xt_t && !xt_m)
 927                 return NULL;
 928
 929         entry_test = new_rule(ip, target_name, xt_t, xt_rm);
 930         if (entry_test == NULL)
 931                 return NULL;
 932
 933         if (xt_t != NULL)
 934                 xt_e_t = ipt_get_target(entry_test);
 935         if (xt_m != NULL)
 936                 xt_e_m = (struct xt_entry_match *)entry_test->elems;
 937
 938         entry = chain_head->data;
 939         builtin = entry->builtin;
 940
 941         if (builtin >= 0)
 942                 list = chain_head;
 943         else
 944                 list = chain_head->next;
 945
 946         for (; list != chain_tail->prev; list = list->next) {
 947                 struct connman_iptables_entry *tmp;
 948                 struct ipt_entry *tmp_e;
 949
 950                 tmp = list->data;
 951                 tmp_e = tmp->entry;
 952
 953                 if (is_same_ipt_entry(entry_test, tmp_e) == FALSE)
 954                         continue;
 955
 956                 if (xt_t != NULL) {
 957                         struct xt_entry_target *tmp_xt_e_t;
 958
 959                         tmp_xt_e_t = ipt_get_target(tmp_e);
 960
 961                         if (!is_same_target(tmp_xt_e_t, xt_e_t))
 962                                 continue;
 963                 }
 964
 965                 if (xt_m != NULL) {
 966                         struct xt_entry_match *tmp_xt_e_m;
 967
 968                         tmp_xt_e_m = (struct xt_entry_match *)tmp_e->elems;
 969
 970                         if (!is_same_match(tmp_xt_e_m, xt_e_m))
 971                                 continue;
 972                 }
 973
 974                 break;
 975         }
 976
 977         g_free(entry_test);
 978
 979         if (list != chain_tail->prev)
 980                 return list;
 981
 982         return NULL;
 983 }
 984
 985 static int iptables_delete_rule(struct connman_iptables *table,
 986                                 struct ipt_ip *ip, const char *chain_name,
 987                                 const char *target_name,
 988                                 struct xtables_target *xt_t,
 989                                 struct xtables_match *xt_m,
 990                                 struct xtables_rule_match *xt_rm)
 991 {
 992         struct connman_iptables_entry *entry;
 993         GList *chain_head, *chain_tail, *list;
 994         int builtin, removed;
 995
 996         removed = 0;
 997
 998         chain_head = find_chain_head(table, chain_name);
 999         if (chain_head == NULL)
1000                 return -EINVAL;
1001
1002         chain_tail = find_chain_tail(table, chain_name);
1003         if (chain_tail == NULL)
1004                 return -EINVAL;
1005
1006         list = find_existing_rule(table, ip, chain_name, target_name,
1007                                                         xt_t, xt_m, xt_rm);
1008         if (list == NULL)
1009                 return -EINVAL;
1010
1011         entry = chain_head->data;
1012         builtin = entry->builtin;
1013
1014         entry = list->data;
1015         if (entry == NULL)
1016                 return -EINVAL;
1017
1018         /* We have deleted a rule,
1019          * all references should be bumped accordingly */
1020         if (list->next != NULL)
1021                 update_targets_reference(table, list->next->data,
1022                                                 list->data, TRUE);
1023
1024         removed += remove_table_entry(table, entry);
1025
1026         if (builtin >= 0) {
1027                 list = list->next;
1028                 if (list) {
1029                         entry = list->data;
1030                         entry->builtin = builtin;
1031                 }
1032
1033                 table->underflow[builtin] -= removed;
1034                 for (list = chain_tail; list; list = list->next) {
1035                         entry = list->data;
1036
1037                         builtin = entry->builtin;
1038                         if (builtin < 0)
1039                                 continue;
1040
1041                         table->hook_entry[builtin] -= removed;
1042                         table->underflow[builtin] -= removed;
1043                 }
1044         }
1045
1046         update_offsets(table);
1047
1048         return 0;
1049 }
1050
1051 static int iptables_change_policy(struct connman_iptables *table,
1052                                 const char *chain_name, const char *policy)
1053 {
1054         GList *chain_head, *chain_tail;
1055         struct connman_iptables_entry *entry;
1056         struct xt_entry_target *target;
1057         struct xt_standard_target *t;
1058         int verdict;
1059
1060         verdict = target_to_verdict(policy);
1061         switch (verdict) {
1062         case -NF_ACCEPT - 1:
1063         case -NF_DROP - 1:
1064                 break;
1065         default:
1066                 return -EINVAL;
1067         }
1068
1069         chain_head = find_chain_head(table, chain_name);
1070         if (chain_head == NULL)
1071                 return -EINVAL;
1072
1073         entry = chain_head->data;
1074         if (entry->builtin < 0)
1075                 return -EINVAL;
1076
1077         chain_tail = find_chain_tail(table, chain_name);
1078         if (chain_tail == NULL)
1079                 return -EINVAL;
1080
1081         entry = chain_tail->prev->data;
1082         target = ipt_get_target(entry->entry);
1083
1084         t = (struct xt_standard_target *)target;
1085         t->verdict = verdict;
1086
1087         return 0;
1088 }
1089
1090 static struct ipt_replace *iptables_blob(struct connman_iptables *table)
1091 {
1092         struct ipt_replace *r;
1093         GList *list;
1094         struct connman_iptables_entry *e;
1095         unsigned char *entry_index;
1096
1097         r = g_try_malloc0(sizeof(struct ipt_replace) + table->size);
1098         if (r == NULL)
1099                 return NULL;
1100
1101         memset(r, 0, sizeof(*r) + table->size);
1102
1103         r->counters = g_try_malloc0(sizeof(struct xt_counters)
1104                                 * table->old_entries);
1105         if (r->counters == NULL) {
1106                 g_free(r);
1107                 return NULL;
1108         }
1109
1110         strcpy(r->name, table->info->name);
1111         r->num_entries = table->num_entries;
1112         r->size = table->size;
1113
1114         r->num_counters = table->old_entries;
1115         r->valid_hooks  = table->info->valid_hooks;
1116
1117         memcpy(r->hook_entry, table->hook_entry, sizeof(table->hook_entry));
1118         memcpy(r->underflow, table->underflow, sizeof(table->underflow));
1119
1120         entry_index = (unsigned char *)r->entries;
1121         for (list = table->entries; list; list = list->next) {
1122                 e = list->data;
1123
1124                 memcpy(entry_index, e->entry, e->entry->next_offset);
1125                 entry_index += e->entry->next_offset;
1126         }
1127
1128         return r;
1129 }
1130
1131 static void dump_ip(struct ipt_entry *entry)
1132 {
1133         struct ipt_ip *ip = &entry->ip;
1134         char ip_string[INET6_ADDRSTRLEN];
1135         char ip_mask[INET6_ADDRSTRLEN];
1136
1137         if (strlen(ip->iniface))
1138                 DBG("\tin %s", ip->iniface);
1139
1140         if (strlen(ip->outiface))
1141                 DBG("\tout %s", ip->outiface);
1142
1143         if (inet_ntop(AF_INET, &ip->src, ip_string, INET6_ADDRSTRLEN) != NULL &&
1144                         inet_ntop(AF_INET, &ip->smsk,
1145                                         ip_mask, INET6_ADDRSTRLEN) != NULL)
1146                 DBG("\tsrc %s/%s", ip_string, ip_mask);
1147
1148         if (inet_ntop(AF_INET, &ip->dst, ip_string, INET6_ADDRSTRLEN) != NULL &&
1149                         inet_ntop(AF_INET, &ip->dmsk,
1150                                         ip_mask, INET6_ADDRSTRLEN) != NULL)
1151                 DBG("\tdst %s/%s", ip_string, ip_mask);
1152 }
1153
1154 static void dump_target(struct ipt_entry *entry)
1155
1156 {
1157         struct xtables_target *xt_t;
1158         struct xt_entry_target *target;
1159
1160         target = ipt_get_target(entry);
1161
1162         if (!strcmp(target->u.user.name, IPT_STANDARD_TARGET)) {
1163                 struct xt_standard_target *t;
1164
1165                 t = (struct xt_standard_target *)target;
1166
1167                 switch (t->verdict) {
1168                 case XT_RETURN:
1169                         DBG("\ttarget RETURN");
1170                         break;
1171
1172                 case -NF_ACCEPT - 1:
1173                         DBG("\ttarget ACCEPT");
1174                         break;
1175
1176                 case -NF_DROP - 1:
1177                         DBG("\ttarget DROP");
1178                         break;
1179
1180                 case -NF_QUEUE - 1:
1181                         DBG("\ttarget QUEUE");
1182                         break;
1183
1184                 case -NF_STOP - 1:
1185                         DBG("\ttarget STOP");
1186                         break;
1187
1188                 default:
1189                         DBG("\tJUMP %u", t->verdict);
1190                         break;
1191                 }
1192
1193                 xt_t = xtables_find_target(IPT_STANDARD_TARGET,
1194                                                 XTF_LOAD_MUST_SUCCEED);
1195
1196                 if(xt_t->print != NULL)
1197                         xt_t->print(NULL, target, 1);
1198         } else {
1199                 xt_t = xtables_find_target(target->u.user.name, XTF_TRY_LOAD);
1200                 if (xt_t == NULL) {
1201                         DBG("\ttarget %s", target->u.user.name);
1202                         return;
1203                 }
1204
1205                 if(xt_t->print != NULL) {
1206                         DBG("\ttarget ");
1207                         xt_t->print(NULL, target, 1);
1208                 }
1209         }
1210 }
1211
1212 static void dump_match(struct ipt_entry *entry)
1213 {
1214         struct xtables_match *xt_m;
1215         struct xt_entry_match *match;
1216
1217         if (entry->elems == (unsigned char *)entry + entry->target_offset)
1218                 return;
1219
1220         match = (struct xt_entry_match *) entry->elems;
1221
1222         if (!strlen(match->u.user.name))
1223                 return;
1224
1225         xt_m = xtables_find_match(match->u.user.name, XTF_TRY_LOAD, NULL);
1226         if (xt_m == NULL)
1227                 goto out;
1228
1229         if(xt_m->print != NULL) {
1230                 DBG("\tmatch ");
1231                 xt_m->print(NULL, match, 1);
1232
1233                 return;
1234         }
1235
1236 out:
1237         DBG("\tmatch %s", match->u.user.name);
1238
1239 }
1240
1241 static int dump_entry(struct ipt_entry *entry, int builtin,
1242                         unsigned int hook, size_t size, unsigned int offset,
1243                         void *user_data)
1244 {
1245         struct xt_entry_target *target;
1246
1247         target = ipt_get_target(entry);
1248
1249         if (offset + entry->next_offset == size) {
1250                 DBG("\tEnd of CHAIN");
1251                 return 0;
1252         }
1253
1254         if (!strcmp(target->u.user.name, IPT_ERROR_TARGET)) {
1255                 DBG("\tUSER CHAIN (%s) match %p  target %p",
1256                         target->data, entry->elems,
1257                         (char *)entry + entry->target_offset);
1258
1259                 return 0;
1260         } else if (builtin >= 0) {
1261                 DBG("\tCHAIN (%s) match %p  target %p",
1262                         hooknames[builtin], entry->elems,
1263                         (char *)entry + entry->target_offset);
1264         } else {
1265                 DBG("\tRULE  match %p  target %p",
1266                         entry->elems,
1267                         (char *)entry + entry->target_offset);
1268         }
1269
1270         dump_match(entry);
1271         dump_target(entry);
1272         dump_ip(entry);
1273
1274         return 0;
1275 }
1276
1277 static void dump_table(struct connman_iptables *table)
1278 {
1279         DBG("%s valid_hooks=0x%08x, num_entries=%u, size=%u",
1280                         table->info->name,
1281                         table->info->valid_hooks, table->info->num_entries,
1282                                 table->info->size);
1283
1284         DBG("entry hook: pre/in/fwd/out/post %d/%d/%d/%d/%d",
1285                 table->info->hook_entry[NF_IP_PRE_ROUTING],
1286                 table->info->hook_entry[NF_IP_LOCAL_IN],
1287                 table->info->hook_entry[NF_IP_FORWARD],
1288                 table->info->hook_entry[NF_IP_LOCAL_OUT],
1289                 table->info->hook_entry[NF_IP_POST_ROUTING]);
1290         DBG("underflow:  pre/in/fwd/out/post %d/%d/%d/%d/%d",
1291                 table->info->underflow[NF_IP_PRE_ROUTING],
1292                 table->info->underflow[NF_IP_LOCAL_IN],
1293                 table->info->underflow[NF_IP_FORWARD],
1294                 table->info->underflow[NF_IP_LOCAL_OUT],
1295                 table->info->underflow[NF_IP_POST_ROUTING]);
1296
1297         iterate_entries(table->blob_entries->entrytable,
1298                         table->info->valid_hooks,
1299                         table->info->hook_entry,
1300                         table->info->underflow,
1301                         table->blob_entries->size,
1302                         print_entry, dump_entry);
1303 }
1304
1305 static void dump_ipt_replace(struct ipt_replace *repl)
1306 {
1307         DBG("%s valid_hooks 0x%08x  num_entries %u  size %u",
1308                         repl->name, repl->valid_hooks, repl->num_entries,
1309                         repl->size);
1310
1311         DBG("entry hook: pre/in/fwd/out/post %d/%d/%d/%d/%d",
1312                 repl->hook_entry[NF_IP_PRE_ROUTING],
1313                 repl->hook_entry[NF_IP_LOCAL_IN],
1314                 repl->hook_entry[NF_IP_FORWARD],
1315                 repl->hook_entry[NF_IP_LOCAL_OUT],
1316                 repl->hook_entry[NF_IP_POST_ROUTING]);
1317         DBG("underflow:  pre/in/fwd/out/post %d/%d/%d/%d/%d",
1318                 repl->underflow[NF_IP_PRE_ROUTING],
1319                 repl->underflow[NF_IP_LOCAL_IN],
1320                 repl->underflow[NF_IP_FORWARD],
1321                 repl->underflow[NF_IP_LOCAL_OUT],
1322                 repl->underflow[NF_IP_POST_ROUTING]);
1323
1324         iterate_entries(repl->entries, repl->valid_hooks,
1325                         repl->hook_entry, repl->underflow,
1326                         repl->size, print_entry, dump_entry);
1327 }
1328
1329 static int iptables_get_entries(struct connman_iptables *table)
1330 {
1331         socklen_t entry_size;
1332
1333         entry_size = sizeof(struct ipt_get_entries) + table->info->size;
1334
1335         return getsockopt(table->ipt_sock, IPPROTO_IP, IPT_SO_GET_ENTRIES,
1336                                 table->blob_entries, &entry_size);
1337 }
1338
1339 static int iptables_replace(struct connman_iptables *table,
1340                                         struct ipt_replace *r)
1341 {
1342         return setsockopt(table->ipt_sock, IPPROTO_IP, IPT_SO_SET_REPLACE, r,
1343                          sizeof(*r) + r->size);
1344 }
1345
1346 static int add_entry(struct ipt_entry *entry, int builtin, unsigned int hook,
1347                         size_t size, unsigned offset, void *user_data)
1348 {
1349         struct connman_iptables *table = user_data;
1350         struct ipt_entry *new_entry;
1351
1352         new_entry = g_try_malloc0(entry->next_offset);
1353         if (new_entry == NULL)
1354                 return -ENOMEM;
1355
1356         memcpy(new_entry, entry, entry->next_offset);
1357
1358         return iptables_add_entry(table, new_entry, NULL, builtin);
1359 }
1360
1361 static void table_cleanup(struct connman_iptables *table)
1362 {
1363         GList *list;
1364         struct connman_iptables_entry *entry;
1365
1366         if (table == NULL)
1367                 return;
1368
1369         if (table->ipt_sock >= 0)
1370                 close(table->ipt_sock);
1371
1372         for (list = table->entries; list; list = list->next) {
1373                 entry = list->data;
1374
1375                 g_free(entry->entry);
1376                 g_free(entry);
1377         }
1378
1379         g_list_free(table->entries);
1380         g_free(table->info);
1381         g_free(table->blob_entries);
1382         g_free(table);
1383 }
1384
1385 static struct connman_iptables *iptables_init(const char *table_name)
1386 {
1387         struct connman_iptables *table = NULL;
1388         char *module = NULL;
1389         socklen_t s;
1390
1391         if (table_name == NULL)
1392                 table_name = "filter";
1393
1394         DBG("%s", table_name);
1395
1396         if (xtables_insmod("ip_tables", NULL, TRUE) != 0)
1397                 DBG("ip_tables module loading gives error but trying anyway");
1398
1399         module = g_strconcat("iptable_", table_name, NULL);
1400         if (module == NULL)
1401                 return NULL;
1402
1403         if (xtables_insmod(module, NULL, TRUE) != 0)
1404                 DBG("%s module loading gives error but trying anyway", module);
1405
1406         g_free(module);
1407
1408         table = g_hash_table_lookup(table_hash, table_name);
1409         if (table != NULL)
1410                 return table;
1411
1412         table = g_try_new0(struct connman_iptables, 1);
1413         if (table == NULL)
1414                 return NULL;
1415
1416         table->info = g_try_new0(struct ipt_getinfo, 1);
1417         if (table->info == NULL)
1418                 goto err;
1419
1420         table->ipt_sock = socket(AF_INET, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_RAW);
1421         if (table->ipt_sock < 0)
1422                 goto err;
1423
1424         s = sizeof(*table->info);
1425         strcpy(table->info->name, table_name);
1426         if (getsockopt(table->ipt_sock, IPPROTO_IP, IPT_SO_GET_INFO,
1427                                                 table->info, &s) < 0) {
1428                 connman_error("iptables support missing error %d (%s)", errno,
1429                         strerror(errno));
1430                 goto err;
1431         }
1432
1433         table->blob_entries = g_try_malloc0(sizeof(struct ipt_get_entries) +
1434                                                 table->info->size);
1435         if (table->blob_entries == NULL)
1436                 goto err;
1437
1438         strcpy(table->blob_entries->name, table_name);
1439         table->blob_entries->size = table->info->size;
1440
1441         if (iptables_get_entries(table) < 0)
1442                 goto err;
1443
1444         table->num_entries = 0;
1445         table->old_entries = table->info->num_entries;
1446         table->size = 0;
1447
1448         memcpy(table->underflow, table->info->underflow,
1449                                 sizeof(table->info->underflow));
1450         memcpy(table->hook_entry, table->info->hook_entry,
1451                                 sizeof(table->info->hook_entry));
1452
1453         iterate_entries(table->blob_entries->entrytable,
1454                         table->info->valid_hooks, table->info->hook_entry,
1455                         table->info->underflow, table->blob_entries->size,
1456                         add_entry, table);
1457
1458         g_hash_table_insert(table_hash, g_strdup(table_name), table);
1459
1460         if (debug_enabled == TRUE)
1461                 dump_table(table);
1462
1463         return table;
1464
1465 err:
1466         table_cleanup(table);
1467
1468         return NULL;
1469 }
1470
1471 static struct option iptables_opts[] = {
1472         {.name = "append",        .has_arg = 1, .val = 'A'},
1473         {.name = "compare",       .has_arg = 1, .val = 'C'},
1474         {.name = "delete",        .has_arg = 1, .val = 'D'},
1475         {.name = "flush-chain",   .has_arg = 1, .val = 'F'},
1476         {.name = "insert",        .has_arg = 1, .val = 'I'},
1477         {.name = "list",          .has_arg = 2, .val = 'L'},
1478         {.name = "new-chain",     .has_arg = 1, .val = 'N'},
1479         {.name = "policy",        .has_arg = 1, .val = 'P'},
1480         {.name = "delete-chain",  .has_arg = 1, .val = 'X'},
1481         {.name = "destination",   .has_arg = 1, .val = 'd'},
1482         {.name = "in-interface",  .has_arg = 1, .val = 'i'},
1483         {.name = "jump",          .has_arg = 1, .val = 'j'},
1484         {.name = "match",         .has_arg = 1, .val = 'm'},
1485         {.name = "out-interface", .has_arg = 1, .val = 'o'},
1486         {.name = "source",        .has_arg = 1, .val = 's'},
1487         {.name = "table",         .has_arg = 1, .val = 't'},
1488         {NULL},
1489 };
1490
1491 struct xtables_globals iptables_globals = {
1492         .option_offset = 0,
1493         .opts = iptables_opts,
1494         .orig_opts = iptables_opts,
1495 };
1496
1497 static struct xtables_target *prepare_target(struct connman_iptables *table,
1498                                                         const char *target_name)
1499 {
1500         struct xtables_target *xt_t = NULL;
1501         gboolean is_builtin, is_user_defined;
1502         GList *chain_head = NULL;
1503         size_t target_size;
1504
1505         is_builtin = FALSE;
1506         is_user_defined = FALSE;
1507
1508         if (is_builtin_target(target_name))
1509                 is_builtin = TRUE;
1510         else {
1511                 chain_head = find_chain_head(table, target_name);
1512                 if (chain_head != NULL && chain_head->next != NULL)
1513                         is_user_defined = TRUE;
1514         }
1515
1516         if (is_builtin || is_user_defined)
1517                 xt_t = xtables_find_target(IPT_STANDARD_TARGET,
1518                                                 XTF_LOAD_MUST_SUCCEED);
1519         else
1520                 xt_t = xtables_find_target(target_name, XTF_TRY_LOAD);
1521
1522         if (xt_t == NULL)
1523                 return NULL;
1524
1525         target_size = ALIGN(sizeof(struct ipt_entry_target)) + xt_t->size;
1526
1527         xt_t->t = g_try_malloc0(target_size);
1528         if (xt_t->t == NULL)
1529                 return NULL;
1530
1531         xt_t->t->u.target_size = target_size;
1532
1533         if (is_builtin || is_user_defined) {
1534                 struct xt_standard_target *target;
1535
1536                 target = (struct xt_standard_target *)(xt_t->t);
1537                 strcpy(target->target.u.user.name, IPT_STANDARD_TARGET);
1538
1539                 if (is_builtin == TRUE)
1540                         target->verdict = target_to_verdict(target_name);
1541                 else if (is_user_defined == TRUE) {
1542                         struct connman_iptables_entry *target_rule;
1543
1544                         if (chain_head == NULL) {
1545                                 g_free(xt_t->t);
1546                                 return NULL;
1547                         }
1548
1549                         target_rule = chain_head->next->data;
1550                         target->verdict = target_rule->offset;
1551                 }
1552         } else {
1553                 strcpy(xt_t->t->u.user.name, target_name);
1554                 xt_t->t->u.user.revision = xt_t->revision;
1555                 if (xt_t->init != NULL)
1556                         xt_t->init(xt_t->t);
1557         }
1558
1559         if (xt_t->x6_options != NULL)
1560                 iptables_globals.opts =
1561                         xtables_options_xfrm(
1562                                 iptables_globals.orig_opts,
1563                                 iptables_globals.opts,
1564                                 xt_t->x6_options,
1565                                 &xt_t->option_offset);
1566         else
1567                 iptables_globals.opts =
1568                         xtables_merge_options(
1569                                 iptables_globals.orig_opts,
1570                                 iptables_globals.opts,
1571                                 xt_t->extra_opts,
1572                                 &xt_t->option_offset);
1573
1574         if (iptables_globals.opts == NULL) {
1575                 g_free(xt_t->t);
1576                 xt_t = NULL;
1577         }
1578
1579         return xt_t;
1580 }
1581
1582 static struct xtables_match *prepare_matches(struct connman_iptables *table,
1583                                         struct xtables_rule_match **xt_rm,
1584                                         const char *match_name)
1585 {
1586         struct xtables_match *xt_m;
1587         size_t match_size;
1588
1589         if (match_name == NULL)
1590                 return NULL;
1591
1592         xt_m = xtables_find_match(match_name, XTF_LOAD_MUST_SUCCEED, xt_rm);
1593         match_size = ALIGN(sizeof(struct ipt_entry_match)) + xt_m->size;
1594
1595         xt_m->m = g_try_malloc0(match_size);
1596         if (xt_m->m == NULL)
1597                 return NULL;
1598
1599         xt_m->m->u.match_size = match_size;
1600         strcpy(xt_m->m->u.user.name, xt_m->name);
1601         xt_m->m->u.user.revision = xt_m->revision;
1602
1603         if (xt_m->init != NULL)
1604                 xt_m->init(xt_m->m);
1605
1606         if (xt_m->x6_options != NULL)
1607                 iptables_globals.opts =
1608                         xtables_options_xfrm(
1609                                 iptables_globals.orig_opts,
1610                                 iptables_globals.opts,
1611                                 xt_m->x6_options,
1612                                 &xt_m->option_offset);
1613         else
1614                         iptables_globals.opts =
1615                         xtables_merge_options(
1616                                 iptables_globals.orig_opts,
1617                                 iptables_globals.opts,
1618                                 xt_m->extra_opts,
1619                                 &xt_m->option_offset);
1620
1621         if (iptables_globals.opts == NULL) {
1622                 g_free(xt_m->m);
1623                 xt_m = NULL;
1624         }
1625
1626         return xt_m;
1627 }
1628
1629 static int parse_ip_and_mask(const char *str, struct in_addr *ip, struct in_addr *mask)
1630 {
1631         char **tokens;
1632         uint32_t prefixlength;
1633         uint32_t tmp;
1634         int err;
1635
1636         tokens = g_strsplit(str, "/", 2);
1637         if (tokens == NULL)
1638                 return -1;
1639
1640         if (!inet_pton(AF_INET, tokens[0], ip)) {
1641                 err = -1;
1642                 goto out;
1643         }
1644
1645         if (tokens[1] != NULL) {
1646                 prefixlength = strtol(tokens[1], NULL, 10);
1647                 if (prefixlength > 31) {
1648                         err = -1;
1649                         goto out;
1650                 }
1651
1652                 tmp = ~(0xffffffff >> prefixlength);
1653         } else {
1654                 tmp = 0xffffffff;
1655         }
1656
1657         mask->s_addr = htonl(tmp);
1658         ip->s_addr = ip->s_addr & mask->s_addr;
1659         err = 0;
1660 out:
1661         g_strfreev(tokens);
1662
1663         return err;
1664 }
1665
1666 static struct connman_iptables *pre_load_table(const char *table_name,
1667                                         struct connman_iptables *table)
1668 {
1669         if (table != NULL)
1670                 return table;
1671
1672         return iptables_init(table_name);
1673 }
1674
1675 struct parse_context {
1676         int argc;
1677         char **argv;
1678         struct ipt_ip *ip;
1679         struct xtables_target *xt_t;
1680         struct xtables_match *xt_m;
1681         struct xtables_rule_match *xt_rm;
1682 };
1683
1684 static int prepare_getopt_args(const char *str, struct parse_context *ctx)
1685 {
1686         char **tokens;
1687         int i;
1688
1689         tokens = g_strsplit_set(str, " ", -1);
1690
1691         i = g_strv_length(tokens);
1692
1693         /* Add space for the argv[0] value */
1694         ctx->argc = i + 1;
1695
1696         /* Don't forget the last NULL entry */
1697         ctx->argv = g_try_malloc0((ctx->argc + 1) * sizeof(char *));
1698         if (ctx->argv == NULL) {
1699                 g_strfreev(tokens);
1700                 return -ENOMEM;
1701         }
1702
1703         /*
1704          * getopt_long() jumps over the first token; we need to add some
1705          * random argv[0] entry.
1706          */
1707         ctx->argv[0] = g_strdup("argh");
1708         for (i = 1; i < ctx->argc; i++)
1709                 ctx->argv[i] = tokens[i - 1];
1710
1711         g_free(tokens);
1712
1713         return 0;
1714 }
1715
1716 static int parse_xt_modules(int c, connman_bool_t invert,
1717                                 struct parse_context *ctx)
1718 {
1719         struct xtables_match *m;
1720         struct xtables_rule_match *rm;
1721
1722         for (rm = ctx->xt_rm; rm != NULL; rm = rm->next) {
1723                 if (rm->completed != 0)
1724                         continue;
1725
1726                 m = rm->match;
1727
1728                 if (m->x6_parse == NULL && m->parse == NULL)
1729                         continue;
1730
1731                 if (c < (int) m->option_offset ||
1732                                 c >= (int) m->option_offset
1733                                         + XT_OPTION_OFFSET_SCALE)
1734                         continue;
1735
1736                 xtables_option_mpcall(c, ctx->argv, invert, m, NULL);
1737         }
1738
1739         if (ctx->xt_t == NULL)
1740                 return 0;
1741
1742         if (ctx->xt_t->x6_parse == NULL && ctx->xt_t->parse == NULL)
1743                 return 0;
1744
1745         if (c < (int) ctx->xt_t->option_offset ||
1746                         c >= (int) ctx->xt_t->option_offset
1747                                         + XT_OPTION_OFFSET_SCALE)
1748                 return 0;
1749
1750         xtables_option_tpcall(c, ctx->argv, invert, ctx->xt_t, NULL);
1751
1752         return 0;
1753 }
1754
1755 static int final_check_xt_modules(struct parse_context *ctx)
1756 {
1757         struct xtables_rule_match *rm;
1758
1759         for (rm = ctx->xt_rm; rm != NULL; rm = rm->next)
1760                 xtables_option_mfcall(rm->match);
1761
1762         if (ctx->xt_t != NULL)
1763                 xtables_option_tfcall(ctx->xt_t);
1764
1765         return 0;
1766 }
1767
1768 static int parse_rule_spec(struct connman_iptables *table,
1769                                 struct parse_context *ctx)
1770 {
1771         /*
1772          * How the parser works:
1773          *
1774          *  - If getopt finds 's', 'd', 'i', 'o'.
1775          *    just extract the information.
1776          *  - if '!' is found, set the invert flag to true and
1777          *    removes the '!' from the optarg string and jumps
1778          *    back to getopt to reparse the current optarg string.
1779          *    After reparsing the invert flag is reseted to false.
1780          *  - If 'm' or 'j' is found then call either
1781          *    prepare_matches() or prepare_target(). Those function
1782          *    will modify (extend) the longopts for getopt_long.
1783          *    That means getopt will change its matching context according
1784          *    the loaded target.
1785          *
1786          *    Here an example with iptables-test
1787          *
1788          *    argv[0] = ./tools/iptables-test
1789          *    argv[1] = -t
1790          *    argv[2] = filter
1791          *    argv[3] = -A
1792          *    argv[4] = INPUT
1793          *    argv[5] = -m
1794          *    argv[6] = mark
1795          *    argv[7] = --mark
1796          *    argv[8] = 999
1797          *    argv[9] = -j
1798          *    argv[10] = LOG
1799          *
1800          *    getopt found 'm' then the optarg is "mark" and optind 7
1801          *    The longopts array containts before hitting the `case 'm'`
1802          *
1803          *    val A has_arg 1 name append
1804          *    val C has_arg 1 name compare
1805          *    val D has_arg 1 name delete
1806          *    val F has_arg 1 name flush-chain
1807          *    val I has_arg 1 name insert
1808          *    val L has_arg 2 name list
1809          *    val N has_arg 1 name new-chain
1810          *    val P has_arg 1 name policy
1811          *    val X has_arg 1 name delete-chain
1812          *    val d has_arg 1 name destination
1813          *    val i has_arg 1 name in-interface
1814          *    val j has_arg 1 name jump
1815          *    val m has_arg 1 name match
1816          *    val o has_arg 1 name out-interface
1817          *    val s has_arg 1 name source
1818          *    val t has_arg 1 name table
1819          *
1820          *    After executing the `case 'm'` block longopts is
1821          *
1822          *    val A has_arg 1 name append
1823          *    val C has_arg 1 name compare
1824          *    val D has_arg 1 name delete
1825          *    val F has_arg 1 name flush-chain
1826          *    val I has_arg 1 name insert
1827          *    val L has_arg 2 name list
1828          *    val N has_arg 1 name new-chain
1829          *    val P has_arg 1 name policy
1830          *    val X has_arg 1 name delete-chain
1831          *    val d has_arg 1 name destination
1832          *    val i has_arg 1 name in-interface
1833          *    val j has_arg 1 name jump
1834          *    val m has_arg 1 name match
1835          *    val o has_arg 1 name out-interface
1836          *    val s has_arg 1 name source
1837          *    val t has_arg 1 name table
1838          *    val   has_arg 1 name mark
1839          *
1840          *    So the 'mark' matcher has added the 'mark' options
1841          *    and getopt will then return c '256' optarg "999" optind 9
1842          *    And we will hit the 'default' statement which then
1843          *    will call the matchers parser (xt_m->parser() or
1844          *    xtables_option_mpcall() depending on which version
1845          *    of libxtables is found.
1846          */
1847         connman_bool_t invert = FALSE;
1848         int len, c, err;
1849
1850         DBG("");
1851
1852         ctx->ip = g_try_new0(struct ipt_ip, 1);
1853         if (ctx->ip == NULL)
1854                 return -ENOMEM;
1855
1856         /*
1857          * Tell getopt_long not to generate error messages for unknown
1858          * options and also reset optind back to 0.
1859          */
1860         opterr = 0;
1861         optind = 0;
1862
1863         while ((c = getopt_long(ctx->argc, ctx->argv,
1864                                         "-:d:i:o:s:m:j:",
1865                                         iptables_globals.opts, NULL)) != -1) {
1866                 switch (c) {
1867                 case 's':
1868                         /* Source specification */
1869                         if (!parse_ip_and_mask(optarg,
1870                                                 &ctx->ip->src,
1871                                                 &ctx->ip->smsk))
1872                                 break;
1873
1874                         if (invert)
1875                                 ctx->ip->invflags |= IPT_INV_SRCIP;
1876
1877                         break;
1878                 case 'd':
1879                         /* Destination specification */
1880                         if (!parse_ip_and_mask(optarg,
1881                                                 &ctx->ip->dst,
1882                                                 &ctx->ip->dmsk))
1883                                 break;
1884
1885                         if (invert)
1886                                 ctx->ip->invflags |= IPT_INV_DSTIP;
1887                         break;
1888                 case 'i':
1889                         /* In interface specification */
1890                         len = strlen(optarg);
1891
1892                         if (len + 1 > IFNAMSIZ)
1893                                 break;
1894
1895                         strcpy(ctx->ip->iniface, optarg);
1896                         memset(ctx->ip->iniface_mask, 0xff, len + 1);
1897
1898                         if (invert)
1899                                 ctx->ip->invflags |= IPT_INV_VIA_IN;
1900
1901                         break;
1902                 case 'o':
1903                         /* Out interface specification */
1904                         len = strlen(optarg);
1905
1906                         if (len + 1 > IFNAMSIZ)
1907                                 break;
1908
1909                         strcpy(ctx->ip->outiface, optarg);
1910                         memset(ctx->ip->outiface_mask, 0xff, len + 1);
1911
1912                         if (invert)
1913                                 ctx->ip->invflags |= IPT_INV_VIA_OUT;
1914
1915                         break;
1916                 case 'm':
1917                         /* Matches */
1918                         ctx->xt_m = prepare_matches(table, &ctx->xt_rm, optarg);
1919                         if (ctx->xt_m == NULL) {
1920                                 err = -EINVAL;
1921                                 goto out;
1922                         }
1923
1924                         break;
1925                 case 'j':
1926                         /* Target */
1927                         ctx->xt_t = prepare_target(table, optarg);
1928                         if (ctx->xt_t == NULL) {
1929                                 err = -EINVAL;
1930                                 goto out;
1931                         }
1932
1933                         break;
1934                 case 1:
1935                         if (optarg[0] == '!' && optarg[1] == '\0') {
1936                                 invert = TRUE;
1937
1938                                 /* Remove the '!' from the optarg */
1939                                 optarg[0] = '\0';
1940
1941                                 /*
1942                                  * And recall getopt_long without reseting
1943                                  * invert.
1944                                  */
1945                                 continue;
1946                         }
1947
1948                         break;
1949                 default:
1950                         err = parse_xt_modules(c, invert, ctx);
1951                         if (err == 1)
1952                                 continue;
1953
1954                         break;
1955                 }
1956
1957                 invert = FALSE;
1958         }
1959
1960         err = final_check_xt_modules(ctx);
1961
1962 out:
1963         return err;
1964 }
1965
1966 static void reset_xtables(void)
1967 {
1968         struct xtables_match *xt_m;
1969         struct xtables_target *xt_t;
1970
1971         /*
1972          * As side effect parsing a rule sets some global flags
1973          * which will be evaluated/verified. Let's reset them
1974          * to ensure we can parse more than one rule.
1975          *
1976          * Clear all flags because the flags are only valid
1977          * for one rule.
1978          */
1979         for (xt_m = xtables_matches; xt_m != NULL; xt_m = xt_m->next)
1980                 xt_m->mflags = 0;
1981
1982         for (xt_t = xtables_targets; xt_t != NULL; xt_t = xt_t->next) {
1983                 xt_t->tflags = 0;
1984                 xt_t->used = 0;
1985         }
1986
1987         /*
1988          * We need also to free the memory implicitly allocated
1989          * during parsing (see xtables_options_xfrm()).
1990          * Note xt_params is actually iptables_globals.
1991          */
1992         if (xt_params->opts != xt_params->orig_opts) {
1993                 g_free(xt_params->opts);
1994                 xt_params->opts = xt_params->orig_opts;
1995         }
1996         xt_params->option_offset = 0;
1997 }
1998
1999 static void cleanup_parse_context(struct parse_context *ctx)
2000 {
2001         struct xtables_rule_match *rm, *tmp;
2002
2003         g_strfreev(ctx->argv);
2004         g_free(ctx->ip);
2005         if (ctx->xt_t != NULL) {
2006                 g_free(ctx->xt_t->t);
2007                 ctx->xt_t->t = NULL;
2008         }
2009         if (ctx->xt_m != NULL) {
2010                 g_free(ctx->xt_m->m);
2011                 ctx->xt_m->m = NULL;
2012         }
2013         for (tmp = NULL, rm = ctx->xt_rm; rm != NULL; rm = rm->next) {
2014                 if (tmp != NULL)
2015                         g_free(tmp);
2016                 tmp = rm;
2017         }
2018         g_free(tmp);
2019
2020         g_free(ctx);
2021 }
2022
2023 int __connman_iptables_dump(const char *table_name)
2024 {
2025         struct connman_iptables *table;
2026
2027         DBG("-t %s -L", table_name);
2028
2029         table = pre_load_table(table_name, NULL);
2030         if (table == NULL)
2031                 return -EINVAL;
2032
2033         dump_table(table);
2034
2035         return 0;
2036 }
2037
2038 int __connman_iptables_new_chain(const char *table_name,
2039                                         const char *chain)
2040 {
2041         struct connman_iptables *table;
2042
2043         DBG("-t %s -N %s", table_name, chain);
2044
2045         table = pre_load_table(table_name, NULL);
2046         if (table == NULL)
2047                 return -EINVAL;
2048
2049         return iptables_add_chain(table, chain);
2050 }
2051
2052 int __connman_iptables_delete_chain(const char *table_name,
2053                                         const char *chain)
2054 {
2055         struct connman_iptables *table;
2056
2057         DBG("-t %s -X %s", table_name, chain);
2058
2059         table = pre_load_table(table_name, NULL);
2060         if (table == NULL)
2061                 return -EINVAL;
2062
2063         return iptables_delete_chain(table, chain);
2064 }
2065
2066 int __connman_iptables_flush_chain(const char *table_name,
2067                                         const char *chain)
2068 {
2069         struct connman_iptables *table;
2070
2071         DBG("-t %s -F %s", table_name, chain);
2072
2073         table = pre_load_table(table_name, NULL);
2074         if (table == NULL)
2075                 return -EINVAL;
2076
2077         return iptables_flush_chain(table, chain);
2078 }
2079
2080 int __connman_iptables_change_policy(const char *table_name,
2081                                         const char *chain,
2082                                         const char *policy)
2083 {
2084         struct connman_iptables *table;
2085
2086         DBG("-t %s -F %s", table_name, chain);
2087
2088         table = pre_load_table(table_name, NULL);
2089         if (table == NULL)
2090                 return -EINVAL;
2091
2092         return iptables_change_policy(table, chain, policy);
2093 }
2094
2095 int __connman_iptables_append(const char *table_name,
2096                                 const char *chain,
2097                                 const char *rule_spec)
2098 {
2099         struct connman_iptables *table;
2100         struct parse_context *ctx;
2101         const char *target_name;
2102         int err;
2103
2104         ctx = g_try_new0(struct parse_context, 1);
2105         if (ctx == NULL)
2106                 return -ENOMEM;
2107
2108         DBG("-t %s -A %s %s", table_name, chain, rule_spec);
2109
2110         err = prepare_getopt_args(rule_spec, ctx);
2111         if (err < 0)
2112                 goto out;
2113
2114         table = pre_load_table(table_name, NULL);
2115         if (table == NULL) {
2116                 err = -EINVAL;
2117                 goto out;
2118         }
2119
2120         err = parse_rule_spec(table, ctx);
2121         if (err < 0)
2122                 goto out;
2123
2124         if (ctx->xt_t == NULL)
2125                 target_name = NULL;
2126         else
2127                 target_name = ctx->xt_t->name;
2128
2129         err = iptables_append_rule(table, ctx->ip, chain,
2130                                 target_name, ctx->xt_t, ctx->xt_rm);
2131 out:
2132         cleanup_parse_context(ctx);
2133         reset_xtables();
2134
2135         return err;
2136 }
2137
2138 int __connman_iptables_delete(const char *table_name,
2139                                 const char *chain,
2140                                 const char *rule_spec)
2141 {
2142         struct connman_iptables *table;
2143         struct parse_context *ctx;
2144         const char *target_name;
2145         int err;
2146
2147         ctx = g_try_new0(struct parse_context, 1);
2148         if (ctx == NULL)
2149                 return -ENOMEM;
2150
2151         DBG("-t %s -D %s %s", table_name, chain, rule_spec);
2152
2153         err = prepare_getopt_args(rule_spec, ctx);
2154         if (err < 0)
2155                 goto out;
2156
2157         table = pre_load_table(table_name, NULL);
2158         if (table == NULL) {
2159                 err = -EINVAL;
2160                 goto out;
2161         }
2162
2163         err = parse_rule_spec(table, ctx);
2164         if (err < 0)
2165                 goto out;
2166
2167         if (ctx->xt_t == NULL)
2168                 target_name = NULL;
2169         else
2170                 target_name = ctx->xt_t->name;
2171
2172         err = iptables_delete_rule(table, ctx->ip, chain,
2173                                 target_name, ctx->xt_t, ctx->xt_m,
2174                                 ctx->xt_rm);
2175 out:
2176         cleanup_parse_context(ctx);
2177         reset_xtables();
2178
2179         return err;
2180 }
2181
2182 int __connman_iptables_commit(const char *table_name)
2183 {
2184         struct connman_iptables *table;
2185         struct ipt_replace *repl;
2186         int err;
2187
2188         DBG("%s", table_name);
2189
2190         table = g_hash_table_lookup(table_hash, table_name);
2191         if (table == NULL)
2192                 return -EINVAL;
2193
2194         repl = iptables_blob(table);
2195
2196         if (debug_enabled == TRUE)
2197                 dump_ipt_replace(repl);
2198
2199         err = iptables_replace(table, repl);
2200
2201         g_free(repl->counters);
2202         g_free(repl);
2203
2204         if (err < 0)
2205             return err;
2206
2207         g_hash_table_remove(table_hash, table_name);
2208
2209         return 0;
2210 }
2211
2212 static void remove_table(gpointer user_data)
2213 {
2214         struct connman_iptables *table = user_data;
2215
2216         table_cleanup(table);
2217 }
2218
2219 static int flush_table_cb(struct ipt_entry *entry, int builtin,
2220                                 unsigned int hook, size_t size,
2221                                 unsigned int offset, void *user_data)
2222 {
2223         GSList **chains = user_data;
2224         struct xt_entry_target *target;
2225         char *name;
2226
2227         if (offset + entry->next_offset == size)
2228                 return 0;
2229
2230         target = ipt_get_target(entry);
2231
2232         if (!strcmp(target->u.user.name, IPT_ERROR_TARGET))
2233                 name = g_strdup((const char*)target->data);
2234         else if (builtin >= 0)
2235                   name = g_strdup(hooknames[builtin]);
2236         else
2237                 return 0;
2238
2239         *chains = g_slist_prepend(*chains, name);
2240
2241         return 0;
2242 }
2243
2244 void flush_table(const char *name)
2245 {
2246         GSList *chains = NULL, *list;
2247         struct connman_iptables *table;
2248
2249         table = pre_load_table(name, NULL);
2250         if (table == NULL)
2251                 return;
2252
2253         iterate_entries(table->blob_entries->entrytable,
2254                         table->info->valid_hooks,
2255                         table->info->hook_entry,
2256                         table->info->underflow,
2257                         table->blob_entries->size,
2258                         flush_table_cb, &chains);
2259
2260
2261         /*
2262          * The offset update code is fragile and it works
2263          * only safe if we remove elements and move forwards
2264          * in the table.
2265          */
2266         chains = g_slist_reverse(chains);
2267
2268         for (list = chains; list != NULL; list = list->next) {
2269                 char *chain = list->data;
2270
2271                 DBG("chain %s", chain);
2272                 iptables_flush_chain(table, chain);
2273         }
2274
2275         __connman_iptables_commit(name);
2276         g_slist_free_full(chains, g_free);
2277 }
2278
2279 int __connman_iptables_init(void)
2280 {
2281         DBG("");
2282
2283         if (getenv("CONNMAN_IPTABLES_DEBUG"))
2284                 debug_enabled = TRUE;
2285
2286         table_hash = g_hash_table_new_full(g_str_hash, g_str_equal,
2287                                                 g_free, remove_table);
2288
2289         xtables_init_all(&iptables_globals, NFPROTO_IPV4);
2290
2291         return 0;
2292 }
2293
2294 void __connman_iptables_cleanup(void)
2295 {
2296         DBG("");
2297
2298         g_hash_table_destroy(table_hash);
2299 }