1 /**
2 * This file was imported from the iptables sources.
3 * Copyright (C) 1999-2008 Netfilter Core Team
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
19 /* Library which manipulates firewall rules. Version $Revision: 7138 $ */
21 /* Architecture of firewall rules is as follows:
22 *
23 * Chains go INPUT, FORWARD, OUTPUT then user chains.
24 * Each user chain starts with an ERROR node.
25 * Every chain ends with an unconditional jump: a RETURN for user chains,
26 * and a POLICY for built-ins.
27 */
29 /* (C) 1999 Paul ``Rusty'' Russell - Placed under the GNU GPL (See
30 * COPYING for details).
31 * (C) 2000-2004 by the Netfilter Core Team <coreteam@netfilter.org>
32 *
33 * 2003-Jun-20: Harald Welte <laforge@netfilter.org>:
34 * - Reimplementation of chain cache to use offsets instead of entries
35 * 2003-Jun-23: Harald Welte <laforge@netfilter.org>:
36 * - performance optimization, sponsored by Astaro AG (http://www.astaro.com/)
37 * don't rebuild the chain cache after every operation, instead fix it
38 * up after a ruleset change.
39 * 2004-Aug-18: Harald Welte <laforge@netfilter.org>:
40 * - futher performance work: total reimplementation of libiptc.
41 * - libiptc now has a real internal (linked-list) represntation of the
42 * ruleset and a parser/compiler from/to this internal representation
43 * - again sponsored by Astaro AG (http://www.astaro.com/)
44 */
45 #include <sys/types.h>
46 #include <sys/socket.h>
47 #include "xtables.h"
49 #include "linux_list.h"
51 //#define IPTC_DEBUG2 1
53 #ifdef IPTC_DEBUG2
54 #include <fcntl.h>
55 #define DEBUGP(x, args...) fprintf(stderr, "%s: " x, __FUNCTION__, ## args)
56 #define DEBUGP_C(x, args...) fprintf(stderr, x, ## args)
57 #else
58 #define DEBUGP(x, args...)
59 #define DEBUGP_C(x, args...)
60 #endif
62 #ifdef DEBUG
63 #define debug(x, args...) fprintf(stderr, x, ## args)
64 #else
65 #define debug(x, args...)
66 #endif
68 static int sockfd = -1;
69 static int sockfd_use = 0;
70 static void *iptc_fn = NULL;
72 static const char *hooknames[] = {
73 [HOOK_PRE_ROUTING] = "PREROUTING",
74 [HOOK_LOCAL_IN] = "INPUT",
75 [HOOK_FORWARD] = "FORWARD",
76 [HOOK_LOCAL_OUT] = "OUTPUT",
77 [HOOK_POST_ROUTING] = "POSTROUTING",
78 #ifdef HOOK_DROPPING
79 [HOOK_DROPPING] = "DROPPING"
80 #endif
81 };
83 /* Convenience structures */
84 struct ipt_error_target
85 {
86 STRUCT_ENTRY_TARGET t;
87 char error[TABLE_MAXNAMELEN];
88 };
90 struct chain_head;
91 struct rule_head;
93 struct counter_map
94 {
95 enum {
96 COUNTER_MAP_NOMAP,
97 COUNTER_MAP_NORMAL_MAP,
98 COUNTER_MAP_ZEROED,
99 COUNTER_MAP_SET
100 } maptype;
101 unsigned int mappos;
102 };
104 enum iptcc_rule_type {
105 IPTCC_R_STANDARD, /* standard target (ACCEPT, ...) */
106 IPTCC_R_MODULE, /* extension module (SNAT, ...) */
107 IPTCC_R_FALLTHROUGH, /* fallthrough rule */
108 IPTCC_R_JUMP, /* jump to other chain */
109 };
111 struct rule_head
112 {
113 struct list_head list;
114 struct chain_head *chain;
115 struct counter_map counter_map;
117 unsigned int index; /* index (needed for counter_map) */
118 unsigned int offset; /* offset in rule blob */
120 enum iptcc_rule_type type;
121 struct chain_head *jump; /* jump target, if IPTCC_R_JUMP */
123 unsigned int size; /* size of entry data */
124 STRUCT_ENTRY entry[0];
125 };
127 struct chain_head
128 {
129 struct list_head list;
130 char name[TABLE_MAXNAMELEN];
131 unsigned int hooknum; /* hook number+1 if builtin */
132 unsigned int references; /* how many jumps reference us */
133 int verdict; /* verdict if builtin */
135 STRUCT_COUNTERS counters; /* per-chain counters */
136 struct counter_map counter_map;
138 unsigned int num_rules; /* number of rules in list */
139 struct list_head rules; /* list of rules */
141 unsigned int index; /* index (needed for jump resolval) */
142 unsigned int head_offset; /* offset in rule blob */
143 unsigned int foot_index; /* index (needed for counter_map) */
144 unsigned int foot_offset; /* offset in rule blob */
145 };
147 STRUCT_TC_HANDLE
148 {
149 int changed; /* Have changes been made? */
151 struct list_head chains;
153 struct chain_head *chain_iterator_cur;
154 struct rule_head *rule_iterator_cur;
156 unsigned int num_chains; /* number of user defined chains */
158 struct chain_head **chain_index; /* array for fast chain list access*/
159 unsigned int chain_index_sz;/* size of chain index array */
161 STRUCT_GETINFO info;
162 STRUCT_GET_ENTRIES *entries;
163 };
165 /* allocate a new chain head for the cache */
166 static struct chain_head *iptcc_alloc_chain_head(const char *name, int hooknum)
167 {
168 struct chain_head *c = malloc(sizeof(*c));
169 if (!c)
170 return NULL;
171 memset(c, 0, sizeof(*c));
173 strncpy(c->name, name, TABLE_MAXNAMELEN);
174 c->hooknum = hooknum;
175 INIT_LIST_HEAD(&c->rules);
177 return c;
178 }
180 /* allocate and initialize a new rule for the cache */
181 static struct rule_head *iptcc_alloc_rule(struct chain_head *c, unsigned int size)
182 {
183 struct rule_head *r = malloc(sizeof(*r)+size);
184 if (!r)
185 return NULL;
186 memset(r, 0, sizeof(*r));
188 r->chain = c;
189 r->size = size;
191 return r;
192 }
194 /* notify us that the ruleset has been modified by the user */
195 static inline void
196 set_changed(TC_HANDLE_T h)
197 {
198 h->changed = 1;
199 }
201 #ifdef IPTC_DEBUG
202 static void do_check(TC_HANDLE_T h, unsigned int line);
203 #define CHECK(h) do { if (!getenv("IPTC_NO_CHECK")) do_check((h), __LINE__); } while(0)
204 #else
205 #define CHECK(h)
206 #endif
209 /**********************************************************************
210 * iptc blob utility functions (iptcb_*)
211 **********************************************************************/
213 static inline int
214 iptcb_get_number(const STRUCT_ENTRY *i,
215 const STRUCT_ENTRY *seek,
216 unsigned int *pos)
217 {
218 if (i == seek)
219 return 1;
220 (*pos)++;
221 return 0;
222 }
224 static inline int
225 iptcb_get_entry_n(STRUCT_ENTRY *i,
226 unsigned int number,
227 unsigned int *pos,
228 STRUCT_ENTRY **pe)
229 {
230 if (*pos == number) {
231 *pe = i;
232 return 1;
233 }
234 (*pos)++;
235 return 0;
236 }
238 static inline STRUCT_ENTRY *
239 iptcb_get_entry(TC_HANDLE_T h, unsigned int offset)
240 {
241 return (STRUCT_ENTRY *)((char *)h->entries->entrytable + offset);
242 }
244 static unsigned int
245 iptcb_entry2index(const TC_HANDLE_T h, const STRUCT_ENTRY *seek)
246 {
247 unsigned int pos = 0;
249 if (ENTRY_ITERATE(h->entries->entrytable, h->entries->size,
250 iptcb_get_number, seek, &pos) == 0) {
251 fprintf(stderr, "ERROR: offset %u not an entry!\n",
252 (unsigned int)((char *)seek - (char *)h->entries->entrytable));
253 abort();
254 }
255 return pos;
256 }
258 static inline STRUCT_ENTRY *
259 iptcb_offset2entry(TC_HANDLE_T h, unsigned int offset)
260 {
261 return (STRUCT_ENTRY *) ((void *)h->entries->entrytable+offset);
262 }
265 static inline unsigned long
266 iptcb_entry2offset(const TC_HANDLE_T h, const STRUCT_ENTRY *e)
267 {
268 return (void *)e - (void *)h->entries->entrytable;
269 }
271 static inline unsigned int
272 iptcb_offset2index(const TC_HANDLE_T h, unsigned int offset)
273 {
274 return iptcb_entry2index(h, iptcb_offset2entry(h, offset));
275 }
277 /* Returns 0 if not hook entry, else hooknumber + 1 */
278 static inline unsigned int
279 iptcb_ent_is_hook_entry(STRUCT_ENTRY *e, TC_HANDLE_T h)
280 {
281 unsigned int i;
283 for (i = 0; i < NUMHOOKS; i++) {
284 if ((h->info.valid_hooks & (1 << i))
285 && iptcb_get_entry(h, h->info.hook_entry[i]) == e)
286 return i+1;
287 }
288 return 0;
289 }
292 /**********************************************************************
293 * Chain index (cache utility) functions
294 **********************************************************************
295 * The chain index is an array with pointers into the chain list, with
296 * CHAIN_INDEX_BUCKET_LEN spacing. This facilitates the ability to
297 * speedup chain list searching, by find a more optimal starting
298 * points when searching the linked list.
299 *
300 * The starting point can be found fast by using a binary search of
301 * the chain index. Thus, reducing the previous search complexity of
302 * O(n) to O(log(n/k) + k) where k is CHAIN_INDEX_BUCKET_LEN.
303 *
304 * A nice property of the chain index, is that the "bucket" list
305 * length is max CHAIN_INDEX_BUCKET_LEN (when just build, inserts will
306 * change this). Oppose to hashing, where the "bucket" list length can
307 * vary a lot.
308 */
309 #ifndef CHAIN_INDEX_BUCKET_LEN
310 #define CHAIN_INDEX_BUCKET_LEN 40
311 #endif
313 /* Another nice property of the chain index is that inserting/creating
314 * chains in chain list don't change the correctness of the chain
315 * index, it only causes longer lists in the buckets.
316 *
317 * To mitigate the performance penalty of longer bucket lists and the
318 * penalty of rebuilding, the chain index is rebuild only when
319 * CHAIN_INDEX_INSERT_MAX chains has been added.
320 */
321 #ifndef CHAIN_INDEX_INSERT_MAX
322 #define CHAIN_INDEX_INSERT_MAX 355
323 #endif
325 static inline unsigned int iptcc_is_builtin(struct chain_head *c);
328 /* Use binary search in the chain index array, to find a chain_head
329 * pointer closest to the place of the searched name element.
330 *
331 * Notes that, binary search (obviously) requires that the chain list
332 * is sorted by name.
333 */
334 static struct list_head *
335 iptcc_bsearch_chain_index(const char *name, unsigned int *idx, TC_HANDLE_T handle)
336 {
337 unsigned int pos, end;
338 int res;
340 struct list_head *list_pos;
341 list_pos=&handle->chains;
343 /* Check for empty array, e.g. no user defined chains */
344 if (handle->chain_index_sz == 0) {
345 debug("WARNING: handle->chain_index_sz == 0\n");
346 return list_pos;
347 }
349 /* Init */
350 end = handle->chain_index_sz;
351 pos = end / 2;
353 debug("bsearch Find chain:%s (pos:%d end:%d)\n", name, pos, end);
355 /* Loop */
356 loop:
357 if (!handle->chain_index[pos]) {
358 fprintf(stderr, "ERROR: NULL pointer chain_index[%d]\n", pos);
359 return &handle->chains; /* Be safe, return orig start pos */
360 }
362 res = strcmp(name, handle->chain_index[pos]->name);
363 list_pos = &handle->chain_index[pos]->list;
364 *idx = pos;
366 debug("bsearch Index[%d] name:%s res:%d ",
367 pos, handle->chain_index[pos]->name, res);
369 if (res == 0) { /* Found element, by direct hit */
370 debug("[found] Direct hit pos:%d end:%d\n", pos, end);
371 return list_pos;
372 } else if (res < 0) { /* Too far, jump back */
373 end = pos;
374 pos = pos / 2;
376 /* Exit case: First element of array */
377 if (end == 0) {
378 debug("[found] Reached first array elem (end%d)\n",end);
379 return list_pos;
380 }
381 debug("jump back to pos:%d (end:%d)\n", pos, end);
382 goto loop;
383 } else if (res > 0 ){ /* Not far enough, jump forward */
385 /* Exit case: Last element of array */
386 if (pos == handle->chain_index_sz-1) {
387 debug("[found] Last array elem (end:%d)\n", end);
388 return list_pos;
389 }
391 /* Exit case: Next index less, thus elem in this list section */
392 res = strcmp(name, handle->chain_index[pos+1]->name);
393 if (res < 0) {
394 debug("[found] closest list (end:%d)\n", end);
395 return list_pos;
396 }
398 pos = (pos+end)/2;
399 debug("jump forward to pos:%d (end:%d)\n", pos, end);
400 goto loop;
401 }
403 return list_pos;
404 }
406 #ifdef DEBUG
407 /* Trivial linear search of chain index. Function used for verifying
408 the output of bsearch function */
409 static struct list_head *
410 iptcc_linearly_search_chain_index(const char *name, TC_HANDLE_T handle)
411 {
412 unsigned int i=0;
413 int res=0;
415 struct list_head *list_pos;
416 list_pos = &handle->chains;
418 if (handle->chain_index_sz)
419 list_pos = &handle->chain_index[0]->list;
421 /* Linearly walk of chain index array */
423 for (i=0; i < handle->chain_index_sz; i++) {
424 if (handle->chain_index[i]) {
425 res = strcmp(handle->chain_index[i]->name, name);
426 if (res > 0)
427 break; // One step too far
428 list_pos = &handle->chain_index[i]->list;
429 if (res == 0)
430 break; // Direct hit
431 }
432 }
434 return list_pos;
435 }
436 #endif
438 static int iptcc_chain_index_alloc(TC_HANDLE_T h)
439 {
440 unsigned int list_length = CHAIN_INDEX_BUCKET_LEN;
441 unsigned int array_elems;
442 unsigned int array_mem;
444 /* Allocate memory for the chain index array */
445 array_elems = (h->num_chains / list_length) +
446 (h->num_chains % list_length ? 1 : 0);
447 array_mem = sizeof(h->chain_index) * array_elems;
449 debug("Alloc Chain index, elems:%d mem:%d bytes\n",
450 array_elems, array_mem);
452 h->chain_index = malloc(array_mem);
453 if (!h->chain_index) {
454 h->chain_index_sz = 0;
455 return -ENOMEM;
456 }
457 memset(h->chain_index, 0, array_mem);
458 h->chain_index_sz = array_elems;
460 return 1;
461 }
463 static void iptcc_chain_index_free(TC_HANDLE_T h)
464 {
465 h->chain_index_sz = 0;
466 free(h->chain_index);
467 }
470 #ifdef DEBUG
471 static void iptcc_chain_index_dump(TC_HANDLE_T h)
472 {
473 unsigned int i = 0;
475 /* Dump: contents of chain index array */
476 for (i=0; i < h->chain_index_sz; i++) {
477 if (h->chain_index[i]) {
478 fprintf(stderr, "Chain index[%d].name: %s\n",
479 i, h->chain_index[i]->name);
480 }
481 }
482 }
483 #endif
485 /* Build the chain index */
486 static int iptcc_chain_index_build(TC_HANDLE_T h)
487 {
488 unsigned int list_length = CHAIN_INDEX_BUCKET_LEN;
489 unsigned int chains = 0;
490 unsigned int cindex = 0;
491 struct chain_head *c;
493 /* Build up the chain index array here */
494 debug("Building chain index\n");
496 debug("Number of user defined chains:%d bucket_sz:%d array_sz:%d\n",
497 h->num_chains, list_length, h->chain_index_sz);
499 if (h->chain_index_sz == 0)
500 return 0;
502 list_for_each_entry(c, &h->chains, list) {
504 /* Issue: The index array needs to start after the
505 * builtin chains, as they are not sorted */
506 if (!iptcc_is_builtin(c)) {
507 cindex=chains / list_length;
509 /* Safe guard, break out on array limit, this
510 * is useful if chains are added and array is
511 * rebuild, without realloc of memory. */
512 if (cindex >= h->chain_index_sz)
513 break;
515 if ((chains % list_length)== 0) {
516 debug("\nIndex[%d] Chains:", cindex);
517 h->chain_index[cindex] = c;
518 }
519 chains++;
520 }
521 debug("%s, ", c->name);
522 }
523 debug("\n");
525 return 1;
526 }
528 static int iptcc_chain_index_rebuild(TC_HANDLE_T h)
529 {
530 debug("REBUILD chain index array\n");
531 iptcc_chain_index_free(h);
532 if ((iptcc_chain_index_alloc(h)) < 0)
533 return -ENOMEM;
534 iptcc_chain_index_build(h);
535 return 1;
536 }
538 /* Delete chain (pointer) from index array. Removing an element from
539 * the chain list only affects the chain index array, if the chain
540 * index points-to/uses that list pointer.
541 *
542 * There are different strategies, the simple and safe is to rebuild
543 * the chain index every time. The more advanced is to update the
544 * array index to point to the next element, but that requires some
545 * house keeping and boundry checks. The advanced is implemented, as
546 * the simple approach behaves badly when all chains are deleted
547 * because list_for_each processing will always hit the first chain
548 * index, thus causing a rebuild for every chain.
549 */
550 static int iptcc_chain_index_delete_chain(struct chain_head *c, TC_HANDLE_T h)
551 {
552 struct list_head *index_ptr, *next;
553 struct chain_head *c2;
554 unsigned int idx, idx2;
556 index_ptr = iptcc_bsearch_chain_index(c->name, &idx, h);
558 debug("Del chain[%s] c->list:%p index_ptr:%p\n",
559 c->name, &c->list, index_ptr);
561 /* Save the next pointer */
562 next = c->list.next;
563 list_del(&c->list);
565 if (index_ptr == &c->list) { /* Chain used as index ptr */
567 /* See if its possible to avoid a rebuild, by shifting
568 * to next pointer. Its possible if the next pointer
569 * is located in the same index bucket.
570 */
571 c2 = list_entry(next, struct chain_head, list);
572 iptcc_bsearch_chain_index(c2->name, &idx2, h);
573 if (idx != idx2) {
574 /* Rebuild needed */
575 return iptcc_chain_index_rebuild(h);
576 } else {
577 /* Avoiding rebuild */
578 debug("Update cindex[%d] with next ptr name:[%s]\n",
579 idx, c2->name);
580 h->chain_index[idx]=c2;
581 return 0;
582 }
583 }
584 return 0;
585 }
588 /**********************************************************************
589 * iptc cache utility functions (iptcc_*)
590 **********************************************************************/
592 /* Is the given chain builtin (1) or user-defined (0) */
593 static inline unsigned int iptcc_is_builtin(struct chain_head *c)
594 {
595 return (c->hooknum ? 1 : 0);
596 }
598 /* Get a specific rule within a chain */
599 static struct rule_head *iptcc_get_rule_num(struct chain_head *c,
600 unsigned int rulenum)
601 {
602 struct rule_head *r;
603 unsigned int num = 0;
605 list_for_each_entry(r, &c->rules, list) {
606 num++;
607 if (num == rulenum)
608 return r;
609 }
610 return NULL;
611 }
613 /* Get a specific rule within a chain backwards */
614 static struct rule_head *iptcc_get_rule_num_reverse(struct chain_head *c,
615 unsigned int rulenum)
616 {
617 struct rule_head *r;
618 unsigned int num = 0;
620 list_for_each_entry_reverse(r, &c->rules, list) {
621 num++;
622 if (num == rulenum)
623 return r;
624 }
625 return NULL;
626 }
628 /* Returns chain head if found, otherwise NULL. */
629 static struct chain_head *
630 iptcc_find_chain_by_offset(TC_HANDLE_T handle, unsigned int offset)
631 {
632 struct list_head *pos;
634 if (list_empty(&handle->chains))
635 return NULL;
637 list_for_each(pos, &handle->chains) {
638 struct chain_head *c = list_entry(pos, struct chain_head, list);
639 if (offset >= c->head_offset && offset <= c->foot_offset)
640 return c;
641 }
643 return NULL;
644 }
646 /* Returns chain head if found, otherwise NULL. */
647 static struct chain_head *
648 iptcc_find_label(const char *name, TC_HANDLE_T handle)
649 {
650 struct list_head *pos;
651 struct list_head *list_start_pos;
652 unsigned int i=0;
653 int res;
655 if (list_empty(&handle->chains))
656 return NULL;
658 /* First look at builtin chains */
659 list_for_each(pos, &handle->chains) {
660 struct chain_head *c = list_entry(pos, struct chain_head, list);
661 if (!iptcc_is_builtin(c))
662 break;
663 if (!strcmp(c->name, name))
664 return c;
665 }
667 /* Find a smart place to start the search via chain index */
668 //list_start_pos = iptcc_linearly_search_chain_index(name, handle);
669 list_start_pos = iptcc_bsearch_chain_index(name, &i, handle);
671 /* Handel if bsearch bails out early */
672 if (list_start_pos == &handle->chains) {
673 list_start_pos = pos;
674 }
675 #ifdef DEBUG
676 else {
677 /* Verify result of bsearch against linearly index search */
678 struct list_head *test_pos;
679 struct chain_head *test_c, *tmp_c;
680 test_pos = iptcc_linearly_search_chain_index(name, handle);
681 if (list_start_pos != test_pos) {
682 debug("BUG in chain_index search\n");
683 test_c=list_entry(test_pos, struct chain_head,list);
684 tmp_c =list_entry(list_start_pos,struct chain_head,list);
685 debug("Verify search found:\n");
686 debug(" Chain:%s\n", test_c->name);
687 debug("BSearch found:\n");
688 debug(" Chain:%s\n", tmp_c->name);
689 exit(42);
690 }
691 }
692 #endif
694 /* Initial/special case, no user defined chains */
695 if (handle->num_chains == 0)
696 return NULL;
698 /* Start searching through the chain list */
699 list_for_each(pos, list_start_pos->prev) {
700 struct chain_head *c = list_entry(pos, struct chain_head, list);
701 res = strcmp(c->name, name);
702 debug("List search name:%s == %s res:%d\n", name, c->name, res);
703 if (res==0)
704 return c;
706 /* We can stop earlier as we know list is sorted */
707 if (res>0 && !iptcc_is_builtin(c)) { /* Walked too far*/
708 debug(" Not in list, walked too far, sorted list\n");
709 return NULL;
710 }
712 /* Stop on wrap around, if list head is reached */
713 if (pos == &handle->chains) {
714 debug("Stop, list head reached\n");
715 return NULL;
716 }
717 }
719 debug("List search NOT found name:%s\n", name);
720 return NULL;
721 }
723 /* called when rule is to be removed from cache */
724 static void iptcc_delete_rule(struct rule_head *r)
725 {
726 DEBUGP("deleting rule %p (offset %u)\n", r, r->offset);
727 /* clean up reference count of called chain */
728 if (r->type == IPTCC_R_JUMP
729 && r->jump)
730 r->jump->references--;
732 list_del(&r->list);
733 free(r);
734 }
737 /**********************************************************************
738 * RULESET PARSER (blob -> cache)
739 **********************************************************************/
741 /* Delete policy rule of previous chain, since cache doesn't contain
742 * chain policy rules.
743 * WARNING: This function has ugly design and relies on a lot of context, only
744 * to be called from specific places within the parser */
745 static int __iptcc_p_del_policy(TC_HANDLE_T h, unsigned int num)
746 {
747 const unsigned char *data;
749 if (h->chain_iterator_cur) {
750 /* policy rule is last rule */
751 struct rule_head *pr = (struct rule_head *)
752 h->chain_iterator_cur->rules.prev;
754 /* save verdict */
755 data = GET_TARGET(pr->entry)->data;
756 h->chain_iterator_cur->verdict = *(const int *)data;
758 /* save counter and counter_map information */
759 h->chain_iterator_cur->counter_map.maptype =
760 COUNTER_MAP_NORMAL_MAP;
761 h->chain_iterator_cur->counter_map.mappos = num-1;
762 memcpy(&h->chain_iterator_cur->counters, &pr->entry->counters,
763 sizeof(h->chain_iterator_cur->counters));
765 /* foot_offset points to verdict rule */
766 h->chain_iterator_cur->foot_index = num;
767 h->chain_iterator_cur->foot_offset = pr->offset;
769 /* delete rule from cache */
770 iptcc_delete_rule(pr);
771 h->chain_iterator_cur->num_rules--;
773 return 1;
774 }
775 return 0;
776 }
778 /* alphabetically insert a chain into the list */
779 static inline void iptc_insert_chain(TC_HANDLE_T h, struct chain_head *c)
780 {
781 struct chain_head *tmp;
782 struct list_head *list_start_pos;
783 unsigned int i=1;
785 /* Find a smart place to start the insert search */
786 list_start_pos = iptcc_bsearch_chain_index(c->name, &i, h);
788 /* Handle the case, where chain.name is smaller than index[0] */
789 if (i==0 && strcmp(c->name, h->chain_index[0]->name) <= 0) {
790 h->chain_index[0] = c; /* Update chain index head */
791 list_start_pos = h->chains.next;
792 debug("Update chain_index[0] with %s\n", c->name);
793 }
795 /* Handel if bsearch bails out early */
796 if (list_start_pos == &h->chains) {
797 list_start_pos = h->chains.next;
798 }
800 /* sort only user defined chains */
801 if (!c->hooknum) {
802 list_for_each_entry(tmp, list_start_pos->prev, list) {
803 if (!tmp->hooknum && strcmp(c->name, tmp->name) <= 0) {
804 list_add(&c->list, tmp->list.prev);
805 return;
806 }
808 /* Stop if list head is reached */
809 if (&tmp->list == &h->chains) {
810 debug("Insert, list head reached add to tail\n");
811 break;
812 }
813 }
814 }
816 /* survived till end of list: add at tail */
817 list_add_tail(&c->list, &h->chains);
818 }
820 /* Another ugly helper function split out of cache_add_entry to make it less
821 * spaghetti code */
822 static void __iptcc_p_add_chain(TC_HANDLE_T h, struct chain_head *c,
823 unsigned int offset, unsigned int *num)
824 {
825 struct list_head *tail = h->chains.prev;
826 struct chain_head *ctail;
828 __iptcc_p_del_policy(h, *num);
830 c->head_offset = offset;
831 c->index = *num;
833 /* Chains from kernel are already sorted, as they are inserted
834 * sorted. But there exists an issue when shifting to 1.4.0
835 * from an older version, as old versions allow last created
836 * chain to be unsorted.
837 */
838 if (iptcc_is_builtin(c)) /* Only user defined chains are sorted*/
839 list_add_tail(&c->list, &h->chains);
840 else {
841 ctail = list_entry(tail, struct chain_head, list);
842 if (strcmp(c->name, ctail->name) > 0)
843 list_add_tail(&c->list, &h->chains);/* Already sorted*/
844 else
845 iptc_insert_chain(h, c);/* Was not sorted */
846 }
848 h->chain_iterator_cur = c;
849 }
851 /* main parser function: add an entry from the blob to the cache */
852 static int cache_add_entry(STRUCT_ENTRY *e,
853 TC_HANDLE_T h,
854 STRUCT_ENTRY **prev,
855 unsigned int *num)
856 {
857 unsigned int builtin;
858 unsigned int offset = (char *)e - (char *)h->entries->entrytable;
860 DEBUGP("entering...");
862 /* Last entry ("policy rule"). End it.*/
863 if (iptcb_entry2offset(h,e) + e->next_offset == h->entries->size) {
864 /* This is the ERROR node at the end of the chain */
865 DEBUGP_C("%u:%u: end of table:\n", *num, offset);
867 __iptcc_p_del_policy(h, *num);
869 h->chain_iterator_cur = NULL;
870 goto out_inc;
871 }
873 /* We know this is the start of a new chain if it's an ERROR
874 * target, or a hook entry point */
876 if (strcmp(GET_TARGET(e)->u.user.name, ERROR_TARGET) == 0) {
877 struct chain_head *c =
878 iptcc_alloc_chain_head((const char *)GET_TARGET(e)->data, 0);
879 DEBUGP_C("%u:%u:new userdefined chain %s: %p\n", *num, offset,
880 (char *)c->name, c);
881 if (!c) {
882 errno = -ENOMEM;
883 return -1;
884 }
885 h->num_chains++; /* New user defined chain */
887 __iptcc_p_add_chain(h, c, offset, num);
889 } else if ((builtin = iptcb_ent_is_hook_entry(e, h)) != 0) {
890 struct chain_head *c =
891 iptcc_alloc_chain_head((char *)hooknames[builtin-1],
892 builtin);
893 DEBUGP_C("%u:%u new builtin chain: %p (rules=%p)\n",
894 *num, offset, c, &c->rules);
895 if (!c) {
896 errno = -ENOMEM;
897 return -1;
898 }
900 c->hooknum = builtin;
902 __iptcc_p_add_chain(h, c, offset, num);
904 /* FIXME: this is ugly. */
905 goto new_rule;
906 } else {
907 /* has to be normal rule */
908 struct rule_head *r;
909 new_rule:
911 if (!(r = iptcc_alloc_rule(h->chain_iterator_cur,
912 e->next_offset))) {
913 errno = ENOMEM;
914 return -1;
915 }
916 DEBUGP_C("%u:%u normal rule: %p: ", *num, offset, r);
918 r->index = *num;
919 r->offset = offset;
920 memcpy(r->entry, e, e->next_offset);
921 r->counter_map.maptype = COUNTER_MAP_NORMAL_MAP;
922 r->counter_map.mappos = r->index;
924 /* handling of jumps, etc. */
925 if (!strcmp(GET_TARGET(e)->u.user.name, STANDARD_TARGET)) {
926 STRUCT_STANDARD_TARGET *t;
928 t = (STRUCT_STANDARD_TARGET *)GET_TARGET(e);
929 if (t->target.u.target_size
930 != ALIGN(sizeof(STRUCT_STANDARD_TARGET))) {
931 errno = EINVAL;
932 return -1;
933 }
935 if (t->verdict < 0) {
936 DEBUGP_C("standard, verdict=%d\n", t->verdict);
937 r->type = IPTCC_R_STANDARD;
938 } else if (t->verdict == r->offset+e->next_offset) {
939 DEBUGP_C("fallthrough\n");
940 r->type = IPTCC_R_FALLTHROUGH;
941 } else {
942 DEBUGP_C("jump, target=%u\n", t->verdict);
943 r->type = IPTCC_R_JUMP;
944 /* Jump target fixup has to be deferred
945 * until second pass, since we migh not
946 * yet have parsed the target */
947 }
948 } else {
949 DEBUGP_C("module, target=%s\n", GET_TARGET(e)->u.user.name);
950 r->type = IPTCC_R_MODULE;
951 }
953 list_add_tail(&r->list, &h->chain_iterator_cur->rules);
954 h->chain_iterator_cur->num_rules++;
955 }
956 out_inc:
957 (*num)++;
958 return 0;
959 }
962 /* parse an iptables blob into it's pieces */
963 static int parse_table(TC_HANDLE_T h)
964 {
965 STRUCT_ENTRY *prev;
966 unsigned int num = 0;
967 struct chain_head *c;
969 /* First pass: over ruleset blob */
970 ENTRY_ITERATE(h->entries->entrytable, h->entries->size,
971 cache_add_entry, h, &prev, &num);
973 /* Build the chain index, used for chain list search speedup */
974 if ((iptcc_chain_index_alloc(h)) < 0)
975 return -ENOMEM;
976 iptcc_chain_index_build(h);
978 /* Second pass: fixup parsed data from first pass */
979 list_for_each_entry(c, &h->chains, list) {
980 struct rule_head *r;
981 list_for_each_entry(r, &c->rules, list) {
982 struct chain_head *lc;
983 STRUCT_STANDARD_TARGET *t;
985 if (r->type != IPTCC_R_JUMP)
986 continue;
988 t = (STRUCT_STANDARD_TARGET *)GET_TARGET(r->entry);
989 lc = iptcc_find_chain_by_offset(h, t->verdict);
990 if (!lc)
991 return -1;
992 r->jump = lc;
993 lc->references++;
994 }
995 }
997 /* FIXME: sort chains */
999 return 1;
1000 }
1003 /**********************************************************************
1004 * RULESET COMPILATION (cache -> blob)
1005 **********************************************************************/
1007 /* Convenience structures */
1008 struct iptcb_chain_start{
1009 STRUCT_ENTRY e;
1010 struct ipt_error_target name;
1011 };
1012 #define IPTCB_CHAIN_START_SIZE (sizeof(STRUCT_ENTRY) + \
1013 ALIGN(sizeof(struct ipt_error_target)))
1015 struct iptcb_chain_foot {
1016 STRUCT_ENTRY e;
1017 STRUCT_STANDARD_TARGET target;
1018 };
1019 #define IPTCB_CHAIN_FOOT_SIZE (sizeof(STRUCT_ENTRY) + \
1020 ALIGN(sizeof(STRUCT_STANDARD_TARGET)))
1022 struct iptcb_chain_error {
1023 STRUCT_ENTRY entry;
1024 struct ipt_error_target target;
1025 };
1026 #define IPTCB_CHAIN_ERROR_SIZE (sizeof(STRUCT_ENTRY) + \
1027 ALIGN(sizeof(struct ipt_error_target)))
1031 /* compile rule from cache into blob */
1032 static inline int iptcc_compile_rule (TC_HANDLE_T h, STRUCT_REPLACE *repl, struct rule_head *r)
1033 {
1034 /* handle jumps */
1035 if (r->type == IPTCC_R_JUMP) {
1036 STRUCT_STANDARD_TARGET *t;
1037 t = (STRUCT_STANDARD_TARGET *)GET_TARGET(r->entry);
1038 /* memset for memcmp convenience on delete/replace */
1039 memset(t->target.u.user.name, 0, FUNCTION_MAXNAMELEN);
1040 strcpy(t->target.u.user.name, STANDARD_TARGET);
1041 /* Jumps can only happen to builtin chains, so we
1042 * can safely assume that they always have a header */
1043 t->verdict = r->jump->head_offset + IPTCB_CHAIN_START_SIZE;
1044 } else if (r->type == IPTCC_R_FALLTHROUGH) {
1045 STRUCT_STANDARD_TARGET *t;
1046 t = (STRUCT_STANDARD_TARGET *)GET_TARGET(r->entry);
1047 t->verdict = r->offset + r->size;
1048 }
1050 /* copy entry from cache to blob */
1051 memcpy((char *)repl->entries+r->offset, r->entry, r->size);
1053 return 1;
1054 }
1056 /* compile chain from cache into blob */
1057 static int iptcc_compile_chain(TC_HANDLE_T h, STRUCT_REPLACE *repl, struct chain_head *c)
1058 {
1059 int ret;
1060 struct rule_head *r;
1061 struct iptcb_chain_start *head;
1062 struct iptcb_chain_foot *foot;
1064 /* only user-defined chains have heaer */
1065 if (!iptcc_is_builtin(c)) {
1066 /* put chain header in place */
1067 head = (void *)repl->entries + c->head_offset;
1068 head->e.target_offset = sizeof(STRUCT_ENTRY);
1069 head->e.next_offset = IPTCB_CHAIN_START_SIZE;
1070 strcpy(head->name.t.u.user.name, ERROR_TARGET);
1071 head->name.t.u.target_size =
1072 ALIGN(sizeof(struct ipt_error_target));
1073 strcpy(head->name.error, c->name);
1074 } else {
1075 repl->hook_entry[c->hooknum-1] = c->head_offset;
1076 repl->underflow[c->hooknum-1] = c->foot_offset;
1077 }
1079 /* iterate over rules */
1080 list_for_each_entry(r, &c->rules, list) {
1081 ret = iptcc_compile_rule(h, repl, r);
1082 if (ret < 0)
1083 return ret;
1084 }
1086 /* put chain footer in place */
1087 foot = (void *)repl->entries + c->foot_offset;
1088 foot->e.target_offset = sizeof(STRUCT_ENTRY);
1089 foot->e.next_offset = IPTCB_CHAIN_FOOT_SIZE;
1090 strcpy(foot->target.target.u.user.name, STANDARD_TARGET);
1091 foot->target.target.u.target_size =
1092 ALIGN(sizeof(STRUCT_STANDARD_TARGET));
1093 /* builtin targets have verdict, others return */
1094 if (iptcc_is_builtin(c))
1095 foot->target.verdict = c->verdict;
1096 else
1097 foot->target.verdict = RETURN;
1098 /* set policy-counters */
1099 memcpy(&foot->e.counters, &c->counters, sizeof(STRUCT_COUNTERS));
1101 return 0;
1102 }
1104 /* calculate offset and number for every rule in the cache */
1105 static int iptcc_compile_chain_offsets(TC_HANDLE_T h, struct chain_head *c,
1106 unsigned int *offset, unsigned int *num)
1107 {
1108 struct rule_head *r;
1110 c->head_offset = *offset;
1111 DEBUGP("%s: chain_head %u, offset=%u\n", c->name, *num, *offset);
1113 if (!iptcc_is_builtin(c)) {
1114 /* Chain has header */
1115 *offset += sizeof(STRUCT_ENTRY)
1116 + ALIGN(sizeof(struct ipt_error_target));
1117 (*num)++;
1118 }
1120 list_for_each_entry(r, &c->rules, list) {
1121 DEBUGP("rule %u, offset=%u, index=%u\n", *num, *offset, *num);
1122 r->offset = *offset;
1123 r->index = *num;
1124 *offset += r->size;
1125 (*num)++;
1126 }
1128 DEBUGP("%s; chain_foot %u, offset=%u, index=%u\n", c->name, *num,
1129 *offset, *num);
1130 c->foot_offset = *offset;
1131 c->foot_index = *num;
1132 *offset += sizeof(STRUCT_ENTRY)
1133 + ALIGN(sizeof(STRUCT_STANDARD_TARGET));
1134 (*num)++;
1136 return 1;
1137 }
1139 /* put the pieces back together again */
1140 static int iptcc_compile_table_prep(TC_HANDLE_T h, unsigned int *size)
1141 {
1142 struct chain_head *c;
1143 unsigned int offset = 0, num = 0;
1144 int ret = 0;
1146 /* First pass: calculate offset for every rule */
1147 list_for_each_entry(c, &h->chains, list) {
1148 ret = iptcc_compile_chain_offsets(h, c, &offset, &num);
1149 if (ret < 0)
1150 return ret;
1151 }
1153 /* Append one error rule at end of chain */
1154 num++;
1155 offset += sizeof(STRUCT_ENTRY)
1156 + ALIGN(sizeof(struct ipt_error_target));
1158 /* ruleset size is now in offset */
1159 *size = offset;
1160 return num;
1161 }
1163 static int iptcc_compile_table(TC_HANDLE_T h, STRUCT_REPLACE *repl)
1164 {
1165 struct chain_head *c;
1166 struct iptcb_chain_error *error;
1168 /* Second pass: copy from cache to offsets, fill in jumps */
1169 list_for_each_entry(c, &h->chains, list) {
1170 int ret = iptcc_compile_chain(h, repl, c);
1171 if (ret < 0)
1172 return ret;
1173 }
1175 /* Append error rule at end of chain */
1176 error = (void *)repl->entries + repl->size - IPTCB_CHAIN_ERROR_SIZE;
1177 error->entry.target_offset = sizeof(STRUCT_ENTRY);
1178 error->entry.next_offset = IPTCB_CHAIN_ERROR_SIZE;
1179 error->target.t.u.user.target_size =
1180 ALIGN(sizeof(struct ipt_error_target));
1181 strcpy((char *)&error->target.t.u.user.name, ERROR_TARGET);
1182 strcpy((char *)&error->target.error, "ERROR");
1184 return 1;
1185 }
1187 /**********************************************************************
1188 * EXTERNAL API (operates on cache only)
1189 **********************************************************************/
1191 /* Allocate handle of given size */
1192 static TC_HANDLE_T
1193 alloc_handle(const char *tablename, unsigned int size, unsigned int num_rules)
1194 {
1195 TC_HANDLE_T h;
1198 h = malloc(sizeof(STRUCT_TC_HANDLE));
1199 if (!h) {
1200 errno = ENOMEM;
1201 return NULL;
1202 }
1203 memset(h, 0, sizeof(*h));
1204 INIT_LIST_HEAD(&h->chains);
1205 strcpy(h->info.name, tablename);
1207 h->entries = malloc(sizeof(STRUCT_GET_ENTRIES) + size);
1208 if (!h->entries)
1209 goto out_free_handle;
1211 strcpy(h->entries->name, tablename);
1212 h->entries->size = size;
1214 return h;
1216 out_free_handle:
1217 free(h);
1219 return NULL;
1220 }
1223 TC_HANDLE_T
1224 TC_INIT(const char *tablename)
1225 {
1226 TC_HANDLE_T h;
1227 STRUCT_GETINFO info;
1228 unsigned int tmp;
1229 socklen_t s;
1231 iptc_fn = TC_INIT;
1233 if (strlen(tablename) >= TABLE_MAXNAMELEN) {
1234 errno = EINVAL;
1235 return NULL;
1236 }
1238 if (sockfd_use == 0) {
1239 sockfd = socket(TC_AF, SOCK_RAW, IPPROTO_RAW);
1240 if (sockfd < 0)
1241 return NULL;
1242 }
1243 sockfd_use++;
1244 retry:
1245 s = sizeof(info);
1247 strcpy(info.name, tablename);
1248 if (getsockopt(sockfd, TC_IPPROTO, SO_GET_INFO, &info, &s) < 0) {
1249 if (--sockfd_use == 0) {
1250 close(sockfd);
1251 sockfd = -1;
1252 }
1253 return NULL;
1254 }
1256 DEBUGP("valid_hooks=0x%08x, num_entries=%u, size=%u\n",
1257 info.valid_hooks, info.num_entries, info.size);
1259 if ((h = alloc_handle(info.name, info.size, info.num_entries))
1260 == NULL) {
1261 if (--sockfd_use == 0) {
1262 close(sockfd);
1263 sockfd = -1;
1264 }
1265 return NULL;
1266 }
1268 /* Initialize current state */
1269 h->info = info;
1271 h->entries->size = h->info.size;
1273 tmp = sizeof(STRUCT_GET_ENTRIES) + h->info.size;
1275 if (getsockopt(sockfd, TC_IPPROTO, SO_GET_ENTRIES, h->entries,
1276 &tmp) < 0)
1277 goto error;
1279 #ifdef IPTC_DEBUG2
1280 {
1281 int fd = open("/tmp/libiptc-so_get_entries.blob",
1282 O_CREAT|O_WRONLY);
1283 if (fd >= 0) {
1284 write(fd, h->entries, tmp);
1285 close(fd);
1286 }
1287 }
1288 #endif
1290 if (parse_table(h) < 0)
1291 goto error;
1293 CHECK(h);
1294 return h;
1295 error:
1296 TC_FREE(&h);
1297 /* A different process changed the ruleset size, retry */
1298 if (errno == EAGAIN)
1299 goto retry;
1300 return NULL;
1301 }
1303 void
1304 TC_FREE(TC_HANDLE_T *h)
1305 {
1306 struct chain_head *c, *tmp;
1308 iptc_fn = TC_FREE;
1309 if (--sockfd_use == 0) {
1310 close(sockfd);
1311 sockfd = -1;
1312 }
1314 list_for_each_entry_safe(c, tmp, &(*h)->chains, list) {
1315 struct rule_head *r, *rtmp;
1317 list_for_each_entry_safe(r, rtmp, &c->rules, list) {
1318 free(r);
1319 }
1321 free(c);
1322 }
1324 iptcc_chain_index_free(*h);
1326 free((*h)->entries);
1327 free(*h);
1329 *h = NULL;
1330 }
1332 static inline int
1333 print_match(const STRUCT_ENTRY_MATCH *m)
1334 {
1335 printf("Match name: `%s'\n", m->u.user.name);
1336 return 0;
1337 }
1339 static int dump_entry(STRUCT_ENTRY *e, const TC_HANDLE_T handle);
1341 void
1342 TC_DUMP_ENTRIES(const TC_HANDLE_T handle)
1343 {
1344 iptc_fn = TC_DUMP_ENTRIES;
1345 CHECK(handle);
1347 printf("libiptc v%s. %u bytes.\n",
1348 XTABLES_VERSION, handle->entries->size);
1349 printf("Table `%s'\n", handle->info.name);
1350 printf("Hooks: pre/in/fwd/out/post = %u/%u/%u/%u/%u\n",
1351 handle->info.hook_entry[HOOK_PRE_ROUTING],
1352 handle->info.hook_entry[HOOK_LOCAL_IN],
1353 handle->info.hook_entry[HOOK_FORWARD],
1354 handle->info.hook_entry[HOOK_LOCAL_OUT],
1355 handle->info.hook_entry[HOOK_POST_ROUTING]);
1356 printf("Underflows: pre/in/fwd/out/post = %u/%u/%u/%u/%u\n",
1357 handle->info.underflow[HOOK_PRE_ROUTING],
1358 handle->info.underflow[HOOK_LOCAL_IN],
1359 handle->info.underflow[HOOK_FORWARD],
1360 handle->info.underflow[HOOK_LOCAL_OUT],
1361 handle->info.underflow[HOOK_POST_ROUTING]);
1363 ENTRY_ITERATE(handle->entries->entrytable, handle->entries->size,
1364 dump_entry, handle);
1365 }
1367 /* Does this chain exist? */
1368 int TC_IS_CHAIN(const char *chain, const TC_HANDLE_T handle)
1369 {
1370 iptc_fn = TC_IS_CHAIN;
1371 return iptcc_find_label(chain, handle) != NULL;
1372 }
1374 static void iptcc_chain_iterator_advance(TC_HANDLE_T handle)
1375 {
1376 struct chain_head *c = handle->chain_iterator_cur;
1378 if (c->list.next == &handle->chains)
1379 handle->chain_iterator_cur = NULL;
1380 else
1381 handle->chain_iterator_cur =
1382 list_entry(c->list.next, struct chain_head, list);
1383 }
1385 /* Iterator functions to run through the chains. */
1386 const char *
1387 TC_FIRST_CHAIN(TC_HANDLE_T *handle)
1388 {
1389 struct chain_head *c = list_entry((*handle)->chains.next,
1390 struct chain_head, list);
1392 iptc_fn = TC_FIRST_CHAIN;
1395 if (list_empty(&(*handle)->chains)) {
1396 DEBUGP(": no chains\n");
1397 return NULL;
1398 }
1400 (*handle)->chain_iterator_cur = c;
1401 iptcc_chain_iterator_advance(*handle);
1403 DEBUGP(": returning `%s'\n", c->name);
1404 return c->name;
1405 }
1407 /* Iterator functions to run through the chains. Returns NULL at end. */
1408 const char *
1409 TC_NEXT_CHAIN(TC_HANDLE_T *handle)
1410 {
1411 struct chain_head *c = (*handle)->chain_iterator_cur;
1413 iptc_fn = TC_NEXT_CHAIN;
1415 if (!c) {
1416 DEBUGP(": no more chains\n");
1417 return NULL;
1418 }
1420 iptcc_chain_iterator_advance(*handle);
1422 DEBUGP(": returning `%s'\n", c->name);
1423 return c->name;
1424 }
1426 /* Get first rule in the given chain: NULL for empty chain. */
1427 const STRUCT_ENTRY *
1428 TC_FIRST_RULE(const char *chain, TC_HANDLE_T *handle)
1429 {
1430 struct chain_head *c;
1431 struct rule_head *r;
1433 iptc_fn = TC_FIRST_RULE;
1435 DEBUGP("first rule(%s): ", chain);
1437 c = iptcc_find_label(chain, *handle);
1438 if (!c) {
1439 errno = ENOENT;
1440 return NULL;
1441 }
1443 /* Empty chain: single return/policy rule */
1444 if (list_empty(&c->rules)) {
1445 DEBUGP_C("no rules, returning NULL\n");
1446 return NULL;
1447 }
1449 r = list_entry(c->rules.next, struct rule_head, list);
1450 (*handle)->rule_iterator_cur = r;
1451 DEBUGP_C("%p\n", r);
1453 return r->entry;
1454 }
1456 /* Returns NULL when rules run out. */
1457 const STRUCT_ENTRY *
1458 TC_NEXT_RULE(const STRUCT_ENTRY *prev, TC_HANDLE_T *handle)
1459 {
1460 struct rule_head *r;
1462 iptc_fn = TC_NEXT_RULE;
1463 DEBUGP("rule_iterator_cur=%p...", (*handle)->rule_iterator_cur);
1465 if (!(*handle)->rule_iterator_cur) {
1466 DEBUGP_C("returning NULL\n");
1467 return NULL;
1468 }
1470 r = list_entry((*handle)->rule_iterator_cur->list.next,
1471 struct rule_head, list);
1473 iptc_fn = TC_NEXT_RULE;
1475 DEBUGP_C("next=%p, head=%p...", &r->list,
1476 &(*handle)->rule_iterator_cur->chain->rules);
1478 if (&r->list == &(*handle)->rule_iterator_cur->chain->rules) {
1479 (*handle)->rule_iterator_cur = NULL;
1480 DEBUGP_C("finished, returning NULL\n");
1481 return NULL;
1482 }
1484 (*handle)->rule_iterator_cur = r;
1486 /* NOTE: prev is without any influence ! */
1487 DEBUGP_C("returning rule %p\n", r);
1488 return r->entry;
1489 }
1491 /* How many rules in this chain? */
1492 #if 0
1493 static unsigned int
1494 TC_NUM_RULES(const char *chain, TC_HANDLE_T *handle)
1495 {
1496 struct chain_head *c;
1497 iptc_fn = TC_NUM_RULES;
1498 CHECK(*handle);
1500 c = iptcc_find_label(chain, *handle);
1501 if (!c) {
1502 errno = ENOENT;
1503 return (unsigned int)-1;
1504 }
1506 return c->num_rules;
1507 }
1508 #endif
1510 #if 0
1511 static const STRUCT_ENTRY *
1512 TC_GET_RULE(const char *chain, unsigned int n, TC_HANDLE_T *handle)
1513 {
1514 struct chain_head *c;
1515 struct rule_head *r;
1517 iptc_fn = TC_GET_RULE;
1519 CHECK(*handle);
1521 c = iptcc_find_label(chain, *handle);
1522 if (!c) {
1523 errno = ENOENT;
1524 return NULL;
1525 }
1527 r = iptcc_get_rule_num(c, n);
1528 if (!r)
1529 return NULL;
1530 return r->entry;
1531 }
1532 #endif
1534 /* Returns a pointer to the target name of this position. */
1535 static const char *standard_target_map(int verdict)
1536 {
1537 switch (verdict) {
1538 case RETURN:
1539 return LABEL_RETURN;
1540 break;
1541 case -NF_ACCEPT-1:
1542 return LABEL_ACCEPT;
1543 break;
1544 case -NF_DROP-1:
1545 return LABEL_DROP;
1546 break;
1547 case -NF_QUEUE-1:
1548 return LABEL_QUEUE;
1549 break;
1550 default:
1551 fprintf(stderr, "ERROR: %d not a valid target)\n",
1552 verdict);
1553 abort();
1554 break;
1555 }
1556 /* not reached */
1557 return NULL;
1558 }
1560 /* Returns a pointer to the target name of this position. */
1561 const char *TC_GET_TARGET(const STRUCT_ENTRY *ce,
1562 TC_HANDLE_T *handle)
1563 {
1564 STRUCT_ENTRY *e = (STRUCT_ENTRY *)ce;
1565 struct rule_head *r = container_of(e, struct rule_head, entry[0]);
1566 const unsigned char *data;
1568 iptc_fn = TC_GET_TARGET;
1570 switch(r->type) {
1571 int spos;
1572 case IPTCC_R_FALLTHROUGH:
1573 return "";
1574 break;
1575 case IPTCC_R_JUMP:
1576 DEBUGP("r=%p, jump=%p, name=`%s'\n", r, r->jump, r->jump->name);
1577 return r->jump->name;
1578 break;
1579 case IPTCC_R_STANDARD:
1580 data = GET_TARGET(e)->data;
1581 spos = *(const int *)data;
1582 DEBUGP("r=%p, spos=%d'\n", r, spos);
1583 return standard_target_map(spos);
1584 break;
1585 case IPTCC_R_MODULE:
1586 return GET_TARGET(e)->u.user.name;
1587 break;
1588 }
1589 return NULL;
1590 }
1591 /* Is this a built-in chain? Actually returns hook + 1. */
1592 int
1593 TC_BUILTIN(const char *chain, const TC_HANDLE_T handle)
1594 {
1595 struct chain_head *c;
1597 iptc_fn = TC_BUILTIN;
1599 c = iptcc_find_label(chain, handle);
1600 if (!c) {
1601 errno = ENOENT;
1602 return 0;
1603 }
1605 return iptcc_is_builtin(c);
1606 }
1608 /* Get the policy of a given built-in chain */
1609 const char *
1610 TC_GET_POLICY(const char *chain,
1611 STRUCT_COUNTERS *counters,
1612 TC_HANDLE_T *handle)
1613 {
1614 struct chain_head *c;
1616 iptc_fn = TC_GET_POLICY;
1618 DEBUGP("called for chain %s\n", chain);
1620 c = iptcc_find_label(chain, *handle);
1621 if (!c) {
1622 errno = ENOENT;
1623 return NULL;
1624 }
1626 if (!iptcc_is_builtin(c))
1627 return NULL;
1629 *counters = c->counters;
1631 return standard_target_map(c->verdict);
1632 }
1634 static int
1635 iptcc_standard_map(struct rule_head *r, int verdict)
1636 {
1637 STRUCT_ENTRY *e = r->entry;
1638 STRUCT_STANDARD_TARGET *t;
1640 t = (STRUCT_STANDARD_TARGET *)GET_TARGET(e);
1642 if (t->target.u.target_size
1643 != ALIGN(sizeof(STRUCT_STANDARD_TARGET))) {
1644 errno = EINVAL;
1645 return 0;
1646 }
1647 /* memset for memcmp convenience on delete/replace */
1648 memset(t->target.u.user.name, 0, FUNCTION_MAXNAMELEN);
1649 strcpy(t->target.u.user.name, STANDARD_TARGET);
1650 t->verdict = verdict;
1652 r->type = IPTCC_R_STANDARD;
1654 return 1;
1655 }
1657 static int
1658 iptcc_map_target(const TC_HANDLE_T handle,
1659 struct rule_head *r)
1660 {
1661 STRUCT_ENTRY *e = r->entry;
1662 STRUCT_ENTRY_TARGET *t = GET_TARGET(e);
1664 /* Maybe it's empty (=> fall through) */
1665 if (strcmp(t->u.user.name, "") == 0) {
1666 r->type = IPTCC_R_FALLTHROUGH;
1667 return 1;
1668 }
1669 /* Maybe it's a standard target name... */
1670 else if (strcmp(t->u.user.name, LABEL_ACCEPT) == 0)
1671 return iptcc_standard_map(r, -NF_ACCEPT - 1);
1672 else if (strcmp(t->u.user.name, LABEL_DROP) == 0)
1673 return iptcc_standard_map(r, -NF_DROP - 1);
1674 else if (strcmp(t->u.user.name, LABEL_QUEUE) == 0)
1675 return iptcc_standard_map(r, -NF_QUEUE - 1);
1676 else if (strcmp(t->u.user.name, LABEL_RETURN) == 0)
1677 return iptcc_standard_map(r, RETURN);
1678 else if (TC_BUILTIN(t->u.user.name, handle)) {
1679 /* Can't jump to builtins. */
1680 errno = EINVAL;
1681 return 0;
1682 } else {
1683 /* Maybe it's an existing chain name. */
1684 struct chain_head *c;
1685 DEBUGP("trying to find chain `%s': ", t->u.user.name);
1687 c = iptcc_find_label(t->u.user.name, handle);
1688 if (c) {
1689 DEBUGP_C("found!\n");
1690 r->type = IPTCC_R_JUMP;
1691 r->jump = c;
1692 c->references++;
1693 return 1;
1694 }
1695 DEBUGP_C("not found :(\n");
1696 }
1698 /* Must be a module? If not, kernel will reject... */
1699 /* memset to all 0 for your memcmp convenience: don't clear version */
1700 memset(t->u.user.name + strlen(t->u.user.name),
1701 0,
1702 FUNCTION_MAXNAMELEN - 1 - strlen(t->u.user.name));
1703 r->type = IPTCC_R_MODULE;
1704 set_changed(handle);
1705 return 1;
1706 }
1708 /* Insert the entry `fw' in chain `chain' into position `rulenum'. */
1709 int
1710 TC_INSERT_ENTRY(const IPT_CHAINLABEL chain,
1711 const STRUCT_ENTRY *e,
1712 unsigned int rulenum,
1713 TC_HANDLE_T *handle)
1714 {
1715 struct chain_head *c;
1716 struct rule_head *r;
1717 struct list_head *prev;
1719 iptc_fn = TC_INSERT_ENTRY;
1721 if (!(c = iptcc_find_label(chain, *handle))) {
1722 errno = ENOENT;
1723 return 0;
1724 }
1726 /* first rulenum index = 0
1727 first c->num_rules index = 1 */
1728 if (rulenum > c->num_rules) {
1729 errno = E2BIG;
1730 return 0;
1731 }
1733 /* If we are inserting at the end just take advantage of the
1734 double linked list, insert will happen before the entry
1735 prev points to. */
1736 if (rulenum == c->num_rules) {
1737 prev = &c->rules;
1738 } else if (rulenum + 1 <= c->num_rules/2) {
1739 r = iptcc_get_rule_num(c, rulenum + 1);
1740 prev = &r->list;
1741 } else {
1742 r = iptcc_get_rule_num_reverse(c, c->num_rules - rulenum);
1743 prev = &r->list;
1744 }
1746 if (!(r = iptcc_alloc_rule(c, e->next_offset))) {
1747 errno = ENOMEM;
1748 return 0;
1749 }
1751 memcpy(r->entry, e, e->next_offset);
1752 r->counter_map.maptype = COUNTER_MAP_SET;
1754 if (!iptcc_map_target(*handle, r)) {
1755 free(r);
1756 return 0;
1757 }
1759 list_add_tail(&r->list, prev);
1760 c->num_rules++;
1762 set_changed(*handle);
1764 return 1;
1765 }
1767 /* Atomically replace rule `rulenum' in `chain' with `fw'. */
1768 int
1769 TC_REPLACE_ENTRY(const IPT_CHAINLABEL chain,
1770 const STRUCT_ENTRY *e,
1771 unsigned int rulenum,
1772 TC_HANDLE_T *handle)
1773 {
1774 struct chain_head *c;
1775 struct rule_head *r, *old;
1777 iptc_fn = TC_REPLACE_ENTRY;
1779 if (!(c = iptcc_find_label(chain, *handle))) {
1780 errno = ENOENT;
1781 return 0;
1782 }
1784 if (rulenum >= c->num_rules) {
1785 errno = E2BIG;
1786 return 0;
1787 }
1789 /* Take advantage of the double linked list if possible. */
1790 if (rulenum + 1 <= c->num_rules/2) {
1791 old = iptcc_get_rule_num(c, rulenum + 1);
1792 } else {
1793 old = iptcc_get_rule_num_reverse(c, c->num_rules - rulenum);
1794 }
1796 if (!(r = iptcc_alloc_rule(c, e->next_offset))) {
1797 errno = ENOMEM;
1798 return 0;
1799 }
1801 memcpy(r->entry, e, e->next_offset);
1802 r->counter_map.maptype = COUNTER_MAP_SET;
1804 if (!iptcc_map_target(*handle, r)) {
1805 free(r);
1806 return 0;
1807 }
1809 list_add(&r->list, &old->list);
1810 iptcc_delete_rule(old);
1812 set_changed(*handle);
1814 return 1;
1815 }
1817 /* Append entry `fw' to chain `chain'. Equivalent to insert with
1818 rulenum = length of chain. */
1819 int
1820 TC_APPEND_ENTRY(const IPT_CHAINLABEL chain,
1821 const STRUCT_ENTRY *e,
1822 TC_HANDLE_T *handle)
1823 {
1824 struct chain_head *c;
1825 struct rule_head *r;
1827 iptc_fn = TC_APPEND_ENTRY;
1828 if (!(c = iptcc_find_label(chain, *handle))) {
1829 DEBUGP("unable to find chain `%s'\n", chain);
1830 errno = ENOENT;
1831 return 0;
1832 }
1834 if (!(r = iptcc_alloc_rule(c, e->next_offset))) {
1835 DEBUGP("unable to allocate rule for chain `%s'\n", chain);
1836 errno = ENOMEM;
1837 return 0;
1838 }
1840 memcpy(r->entry, e, e->next_offset);
1841 r->counter_map.maptype = COUNTER_MAP_SET;
1843 if (!iptcc_map_target(*handle, r)) {
1844 DEBUGP("unable to map target of rule for chain `%s'\n", chain);
1845 free(r);
1846 return 0;
1847 }
1849 list_add_tail(&r->list, &c->rules);
1850 c->num_rules++;
1852 set_changed(*handle);
1854 return 1;
1855 }
1857 static inline int
1858 match_different(const STRUCT_ENTRY_MATCH *a,
1859 const unsigned char *a_elems,
1860 const unsigned char *b_elems,
1861 unsigned char **maskptr)
1862 {
1863 const STRUCT_ENTRY_MATCH *b;
1864 unsigned int i;
1866 /* Offset of b is the same as a. */
1867 b = (void *)b_elems + ((unsigned char *)a - a_elems);
1869 if (a->u.match_size != b->u.match_size)
1870 return 1;
1872 if (strcmp(a->u.user.name, b->u.user.name) != 0)
1873 return 1;
1875 *maskptr += ALIGN(sizeof(*a));
1877 for (i = 0; i < a->u.match_size - ALIGN(sizeof(*a)); i++)
1878 if (((a->data[i] ^ b->data[i]) & (*maskptr)[i]) != 0)
1879 return 1;
1880 *maskptr += i;
1881 return 0;
1882 }
1884 static inline int
1885 target_same(struct rule_head *a, struct rule_head *b,const unsigned char *mask)
1886 {
1887 unsigned int i;
1888 STRUCT_ENTRY_TARGET *ta, *tb;
1890 if (a->type != b->type)
1891 return 0;
1893 ta = GET_TARGET(a->entry);
1894 tb = GET_TARGET(b->entry);
1896 switch (a->type) {
1897 case IPTCC_R_FALLTHROUGH:
1898 return 1;
1899 case IPTCC_R_JUMP:
1900 return a->jump == b->jump;
1901 case IPTCC_R_STANDARD:
1902 return ((STRUCT_STANDARD_TARGET *)ta)->verdict
1903 == ((STRUCT_STANDARD_TARGET *)tb)->verdict;
1904 case IPTCC_R_MODULE:
1905 if (ta->u.target_size != tb->u.target_size)
1906 return 0;
1907 if (strcmp(ta->u.user.name, tb->u.user.name) != 0)
1908 return 0;
1910 for (i = 0; i < ta->u.target_size - sizeof(*ta); i++)
1911 if (((ta->data[i] ^ tb->data[i]) & mask[i]) != 0)
1912 return 0;
1913 return 1;
1914 default:
1915 fprintf(stderr, "ERROR: bad type %i\n", a->type);
1916 abort();
1917 }
1918 }
1920 static unsigned char *
1921 is_same(const STRUCT_ENTRY *a,
1922 const STRUCT_ENTRY *b,
1923 unsigned char *matchmask);
1925 /* Delete the first rule in `chain' which matches `fw'. */
1926 int
1927 TC_DELETE_ENTRY(const IPT_CHAINLABEL chain,
1928 const STRUCT_ENTRY *origfw,
1929 unsigned char *matchmask,
1930 TC_HANDLE_T *handle)
1931 {
1932 struct chain_head *c;
1933 struct rule_head *r, *i;
1935 iptc_fn = TC_DELETE_ENTRY;
1936 if (!(c = iptcc_find_label(chain, *handle))) {
1937 errno = ENOENT;
1938 return 0;
1939 }
1941 /* Create a rule_head from origfw. */
1942 r = iptcc_alloc_rule(c, origfw->next_offset);
1943 if (!r) {
1944 errno = ENOMEM;
1945 return 0;
1946 }
1948 memcpy(r->entry, origfw, origfw->next_offset);
1949 r->counter_map.maptype = COUNTER_MAP_NOMAP;
1950 if (!iptcc_map_target(*handle, r)) {
1951 DEBUGP("unable to map target of rule for chain `%s'\n", chain);
1952 free(r);
1953 return 0;
1954 } else {
1955 /* iptcc_map_target increment target chain references
1956 * since this is a fake rule only used for matching
1957 * the chain references count is decremented again.
1958 */
1959 if (r->type == IPTCC_R_JUMP
1960 && r->jump)
1961 r->jump->references--;
1962 }
1964 list_for_each_entry(i, &c->rules, list) {
1965 unsigned char *mask;
1967 mask = is_same(r->entry, i->entry, matchmask);
1968 if (!mask)
1969 continue;
1971 if (!target_same(r, i, mask))
1972 continue;
1974 /* If we are about to delete the rule that is the
1975 * current iterator, move rule iterator back. next
1976 * pointer will then point to real next node */
1977 if (i == (*handle)->rule_iterator_cur) {
1978 (*handle)->rule_iterator_cur =
1979 list_entry((*handle)->rule_iterator_cur->list.prev,
1980 struct rule_head, list);
1981 }
1983 c->num_rules--;
1984 iptcc_delete_rule(i);
1986 set_changed(*handle);
1987 free(r);
1988 return 1;
1989 }
1991 free(r);
1992 errno = ENOENT;
1993 return 0;
1994 }
1997 /* Delete the rule in position `rulenum' in `chain'. */
1998 int
1999 TC_DELETE_NUM_ENTRY(const IPT_CHAINLABEL chain,
2000 unsigned int rulenum,
2001 TC_HANDLE_T *handle)
2002 {
2003 struct chain_head *c;
2004 struct rule_head *r;
2006 iptc_fn = TC_DELETE_NUM_ENTRY;
2008 if (!(c = iptcc_find_label(chain, *handle))) {
2009 errno = ENOENT;
2010 return 0;
2011 }
2013 if (rulenum >= c->num_rules) {
2014 errno = E2BIG;
2015 return 0;
2016 }
2018 /* Take advantage of the double linked list if possible. */
2019 if (rulenum + 1 <= c->num_rules/2) {
2020 r = iptcc_get_rule_num(c, rulenum + 1);
2021 } else {
2022 r = iptcc_get_rule_num_reverse(c, c->num_rules - rulenum);
2023 }
2025 /* If we are about to delete the rule that is the current
2026 * iterator, move rule iterator back. next pointer will then
2027 * point to real next node */
2028 if (r == (*handle)->rule_iterator_cur) {
2029 (*handle)->rule_iterator_cur =
2030 list_entry((*handle)->rule_iterator_cur->list.prev,
2031 struct rule_head, list);
2032 }
2034 c->num_rules--;
2035 iptcc_delete_rule(r);
2037 set_changed(*handle);
2039 return 1;
2040 }
2042 /* Check the packet `fw' on chain `chain'. Returns the verdict, or
2043 NULL and sets errno. */
2044 const char *
2045 TC_CHECK_PACKET(const IPT_CHAINLABEL chain,
2046 STRUCT_ENTRY *entry,
2047 TC_HANDLE_T *handle)
2048 {
2049 iptc_fn = TC_CHECK_PACKET;
2050 errno = ENOSYS;
2051 return NULL;
2052 }
2054 /* Flushes the entries in the given chain (ie. empties chain). */
2055 int
2056 TC_FLUSH_ENTRIES(const IPT_CHAINLABEL chain, TC_HANDLE_T *handle)
2057 {
2058 struct chain_head *c;
2059 struct rule_head *r, *tmp;
2061 iptc_fn = TC_FLUSH_ENTRIES;
2062 if (!(c = iptcc_find_label(chain, *handle))) {
2063 errno = ENOENT;
2064 return 0;
2065 }
2067 list_for_each_entry_safe(r, tmp, &c->rules, list) {
2068 iptcc_delete_rule(r);
2069 }
2071 c->num_rules = 0;
2073 set_changed(*handle);
2075 return 1;
2076 }
2078 /* Zeroes the counters in a chain. */
2079 int
2080 TC_ZERO_ENTRIES(const IPT_CHAINLABEL chain, TC_HANDLE_T *handle)
2081 {
2082 struct chain_head *c;
2083 struct rule_head *r;
2085 iptc_fn = TC_ZERO_ENTRIES;
2086 if (!(c = iptcc_find_label(chain, *handle))) {
2087 errno = ENOENT;
2088 return 0;
2089 }
2091 if (c->counter_map.maptype == COUNTER_MAP_NORMAL_MAP)
2092 c->counter_map.maptype = COUNTER_MAP_ZEROED;
2094 list_for_each_entry(r, &c->rules, list) {
2095 if (r->counter_map.maptype == COUNTER_MAP_NORMAL_MAP)
2096 r->counter_map.maptype = COUNTER_MAP_ZEROED;
2097 }
2099 set_changed(*handle);
2101 return 1;
2102 }
2104 STRUCT_COUNTERS *
2105 TC_READ_COUNTER(const IPT_CHAINLABEL chain,
2106 unsigned int rulenum,
2107 TC_HANDLE_T *handle)
2108 {
2109 struct chain_head *c;
2110 struct rule_head *r;
2112 iptc_fn = TC_READ_COUNTER;
2113 CHECK(*handle);
2115 if (!(c = iptcc_find_label(chain, *handle))) {
2116 errno = ENOENT;
2117 return NULL;
2118 }
2120 if (!(r = iptcc_get_rule_num(c, rulenum))) {
2121 errno = E2BIG;
2122 return NULL;
2123 }
2125 return &r->entry[0].counters;
2126 }
2128 int
2129 TC_ZERO_COUNTER(const IPT_CHAINLABEL chain,
2130 unsigned int rulenum,
2131 TC_HANDLE_T *handle)
2132 {
2133 struct chain_head *c;
2134 struct rule_head *r;
2136 iptc_fn = TC_ZERO_COUNTER;
2137 CHECK(*handle);
2139 if (!(c = iptcc_find_label(chain, *handle))) {
2140 errno = ENOENT;
2141 return 0;
2142 }
2144 if (!(r = iptcc_get_rule_num(c, rulenum))) {
2145 errno = E2BIG;
2146 return 0;
2147 }
2149 if (r->counter_map.maptype == COUNTER_MAP_NORMAL_MAP)
2150 r->counter_map.maptype = COUNTER_MAP_ZEROED;
2152 set_changed(*handle);
2154 return 1;
2155 }
2157 int
2158 TC_SET_COUNTER(const IPT_CHAINLABEL chain,
2159 unsigned int rulenum,
2160 STRUCT_COUNTERS *counters,
2161 TC_HANDLE_T *handle)
2162 {
2163 struct chain_head *c;
2164 struct rule_head *r;
2165 STRUCT_ENTRY *e;
2167 iptc_fn = TC_SET_COUNTER;
2168 CHECK(*handle);
2170 if (!(c = iptcc_find_label(chain, *handle))) {
2171 errno = ENOENT;
2172 return 0;
2173 }
2175 if (!(r = iptcc_get_rule_num(c, rulenum))) {
2176 errno = E2BIG;
2177 return 0;
2178 }
2180 e = r->entry;
2181 r->counter_map.maptype = COUNTER_MAP_SET;
2183 memcpy(&e->counters, counters, sizeof(STRUCT_COUNTERS));
2185 set_changed(*handle);
2187 return 1;
2188 }
2190 /* Creates a new chain. */
2191 /* To create a chain, create two rules: error node and unconditional
2192 * return. */
2193 int
2194 TC_CREATE_CHAIN(const IPT_CHAINLABEL chain, TC_HANDLE_T *handle)
2195 {
2196 static struct chain_head *c;
2197 int capacity;
2198 int exceeded;
2200 iptc_fn = TC_CREATE_CHAIN;
2202 /* find_label doesn't cover built-in targets: DROP, ACCEPT,
2203 QUEUE, RETURN. */
2204 if (iptcc_find_label(chain, *handle)
2205 || strcmp(chain, LABEL_DROP) == 0
2206 || strcmp(chain, LABEL_ACCEPT) == 0
2207 || strcmp(chain, LABEL_QUEUE) == 0
2208 || strcmp(chain, LABEL_RETURN) == 0) {
2209 DEBUGP("Chain `%s' already exists\n", chain);
2210 errno = EEXIST;
2211 return 0;
2212 }
2214 if (strlen(chain)+1 > sizeof(IPT_CHAINLABEL)) {
2215 DEBUGP("Chain name `%s' too long\n", chain);
2216 errno = EINVAL;
2217 return 0;
2218 }
2220 c = iptcc_alloc_chain_head(chain, 0);
2221 if (!c) {
2222 DEBUGP("Cannot allocate memory for chain `%s'\n", chain);
2223 errno = ENOMEM;
2224 return 0;
2226 }
2227 (*handle)->num_chains++; /* New user defined chain */
2229 DEBUGP("Creating chain `%s'\n", chain);
2230 iptc_insert_chain(*handle, c); /* Insert sorted */
2232 /* Inserting chains don't change the correctness of the chain
2233 * index (except if its smaller than index[0], but that
2234 * handled by iptc_insert_chain). It only causes longer lists
2235 * in the buckets. Thus, only rebuild chain index when the
2236 * capacity is exceed with CHAIN_INDEX_INSERT_MAX chains.
2237 */
2238 capacity = (*handle)->chain_index_sz * CHAIN_INDEX_BUCKET_LEN;
2239 exceeded = ((((*handle)->num_chains)-capacity));
2240 if (exceeded > CHAIN_INDEX_INSERT_MAX) {
2241 debug("Capacity(%d) exceeded(%d) rebuild (chains:%d)\n",
2242 capacity, exceeded, (*handle)->num_chains);
2243 iptcc_chain_index_rebuild(*handle);
2244 }
2246 set_changed(*handle);
2248 return 1;
2249 }
2251 /* Get the number of references to this chain. */
2252 int
2253 TC_GET_REFERENCES(unsigned int *ref, const IPT_CHAINLABEL chain,
2254 TC_HANDLE_T *handle)
2255 {
2256 struct chain_head *c;
2258 iptc_fn = TC_GET_REFERENCES;
2259 if (!(c = iptcc_find_label(chain, *handle))) {
2260 errno = ENOENT;
2261 return 0;
2262 }
2264 *ref = c->references;
2266 return 1;
2267 }
2269 /* Deletes a chain. */
2270 int
2271 TC_DELETE_CHAIN(const IPT_CHAINLABEL chain, TC_HANDLE_T *handle)
2272 {
2273 unsigned int references;
2274 struct chain_head *c;
2276 iptc_fn = TC_DELETE_CHAIN;
2278 if (!(c = iptcc_find_label(chain, *handle))) {
2279 DEBUGP("cannot find chain `%s'\n", chain);
2280 errno = ENOENT;
2281 return 0;
2282 }
2284 if (TC_BUILTIN(chain, *handle)) {
2285 DEBUGP("cannot remove builtin chain `%s'\n", chain);
2286 errno = EINVAL;
2287 return 0;
2288 }
2290 if (!TC_GET_REFERENCES(&references, chain, handle)) {
2291 DEBUGP("cannot get references on chain `%s'\n", chain);
2292 return 0;
2293 }
2295 if (references > 0) {
2296 DEBUGP("chain `%s' still has references\n", chain);
2297 errno = EMLINK;
2298 return 0;
2299 }
2301 if (c->num_rules) {
2302 DEBUGP("chain `%s' is not empty\n", chain);
2303 errno = ENOTEMPTY;
2304 return 0;
2305 }
2307 /* If we are about to delete the chain that is the current
2308 * iterator, move chain iterator forward. */
2309 if (c == (*handle)->chain_iterator_cur)
2310 iptcc_chain_iterator_advance(*handle);
2312 (*handle)->num_chains--; /* One user defined chain deleted */
2314 //list_del(&c->list); /* Done in iptcc_chain_index_delete_chain() */
2315 iptcc_chain_index_delete_chain(c, *handle);
2316 free(c);
2318 DEBUGP("chain `%s' deleted\n", chain);
2320 set_changed(*handle);
2322 return 1;
2323 }
2325 /* Renames a chain. */
2326 int TC_RENAME_CHAIN(const IPT_CHAINLABEL oldname,
2327 const IPT_CHAINLABEL newname,
2328 TC_HANDLE_T *handle)
2329 {
2330 struct chain_head *c;
2331 iptc_fn = TC_RENAME_CHAIN;
2333 /* find_label doesn't cover built-in targets: DROP, ACCEPT,
2334 QUEUE, RETURN. */
2335 if (iptcc_find_label(newname, *handle)
2336 || strcmp(newname, LABEL_DROP) == 0
2337 || strcmp(newname, LABEL_ACCEPT) == 0
2338 || strcmp(newname, LABEL_QUEUE) == 0
2339 || strcmp(newname, LABEL_RETURN) == 0) {
2340 errno = EEXIST;
2341 return 0;
2342 }
2344 if (!(c = iptcc_find_label(oldname, *handle))
2345 || TC_BUILTIN(oldname, *handle)) {
2346 errno = ENOENT;
2347 return 0;
2348 }
2350 if (strlen(newname)+1 > sizeof(IPT_CHAINLABEL)) {
2351 errno = EINVAL;
2352 return 0;
2353 }
2355 strncpy(c->name, newname, sizeof(IPT_CHAINLABEL));
2357 set_changed(*handle);
2359 return 1;
2360 }
2362 /* Sets the policy on a built-in chain. */
2363 int
2364 TC_SET_POLICY(const IPT_CHAINLABEL chain,
2365 const IPT_CHAINLABEL policy,
2366 STRUCT_COUNTERS *counters,
2367 TC_HANDLE_T *handle)
2368 {
2369 struct chain_head *c;
2371 iptc_fn = TC_SET_POLICY;
2373 if (!(c = iptcc_find_label(chain, *handle))) {
2374 DEBUGP("cannot find chain `%s'\n", chain);
2375 errno = ENOENT;
2376 return 0;
2377 }
2379 if (!iptcc_is_builtin(c)) {
2380 DEBUGP("cannot set policy of userdefinedchain `%s'\n", chain);
2381 errno = ENOENT;
2382 return 0;
2383 }
2385 if (strcmp(policy, LABEL_ACCEPT) == 0)
2386 c->verdict = -NF_ACCEPT - 1;
2387 else if (strcmp(policy, LABEL_DROP) == 0)
2388 c->verdict = -NF_DROP - 1;
2389 else {
2390 errno = EINVAL;
2391 return 0;
2392 }
2394 if (counters) {
2395 /* set byte and packet counters */
2396 memcpy(&c->counters, counters, sizeof(STRUCT_COUNTERS));
2397 c->counter_map.maptype = COUNTER_MAP_SET;
2398 } else {
2399 c->counter_map.maptype = COUNTER_MAP_NOMAP;
2400 }
2402 set_changed(*handle);
2404 return 1;
2405 }
2407 /* Without this, on gcc 2.7.2.3, we get:
2408 libiptc.c: In function `TC_COMMIT':
2409 libiptc.c:833: fixed or forbidden register was spilled.
2410 This may be due to a compiler bug or to impossible asm
2411 statements or clauses.
2412 */
2413 static void
2414 subtract_counters(STRUCT_COUNTERS *answer,
2415 const STRUCT_COUNTERS *a,
2416 const STRUCT_COUNTERS *b)
2417 {
2418 answer->pcnt = a->pcnt - b->pcnt;
2419 answer->bcnt = a->bcnt - b->bcnt;
2420 }
2423 static void counters_nomap(STRUCT_COUNTERS_INFO *newcounters, unsigned int idx)
2424 {
2425 newcounters->counters[idx] = ((STRUCT_COUNTERS) { 0, 0});
2426 DEBUGP_C("NOMAP => zero\n");
2427 }
2429 static void counters_normal_map(STRUCT_COUNTERS_INFO *newcounters,
2430 STRUCT_REPLACE *repl, unsigned int idx,
2431 unsigned int mappos)
2432 {
2433 /* Original read: X.
2434 * Atomic read on replacement: X + Y.
2435 * Currently in kernel: Z.
2436 * Want in kernel: X + Y + Z.
2437 * => Add in X + Y
2438 * => Add in replacement read.
2439 */
2440 newcounters->counters[idx] = repl->counters[mappos];
2441 DEBUGP_C("NORMAL_MAP => mappos %u \n", mappos);
2442 }
2444 static void counters_map_zeroed(STRUCT_COUNTERS_INFO *newcounters,
2445 STRUCT_REPLACE *repl, unsigned int idx,
2446 unsigned int mappos, STRUCT_COUNTERS *counters)
2447 {
2448 /* Original read: X.
2449 * Atomic read on replacement: X + Y.
2450 * Currently in kernel: Z.
2451 * Want in kernel: Y + Z.
2452 * => Add in Y.
2453 * => Add in (replacement read - original read).
2454 */
2455 subtract_counters(&newcounters->counters[idx],
2456 &repl->counters[mappos],
2457 counters);
2458 DEBUGP_C("ZEROED => mappos %u\n", mappos);
2459 }
2461 static void counters_map_set(STRUCT_COUNTERS_INFO *newcounters,
2462 unsigned int idx, STRUCT_COUNTERS *counters)
2463 {
2464 /* Want to set counter (iptables-restore) */
2466 memcpy(&newcounters->counters[idx], counters,
2467 sizeof(STRUCT_COUNTERS));
2469 DEBUGP_C("SET\n");
2470 }
2473 int
2474 TC_COMMIT(TC_HANDLE_T *handle)
2475 {
2476 /* Replace, then map back the counters. */
2477 STRUCT_REPLACE *repl;
2478 STRUCT_COUNTERS_INFO *newcounters;
2479 struct chain_head *c;
2480 int ret;
2481 size_t counterlen;
2482 int new_number;
2483 unsigned int new_size;
2485 iptc_fn = TC_COMMIT;
2486 CHECK(*handle);
2488 /* Don't commit if nothing changed. */
2489 if (!(*handle)->changed)
2490 goto finished;
2492 new_number = iptcc_compile_table_prep(*handle, &new_size);
2493 if (new_number < 0) {
2494 errno = ENOMEM;
2495 goto out_zero;
2496 }
2498 repl = malloc(sizeof(*repl) + new_size);
2499 if (!repl) {
2500 errno = ENOMEM;
2501 goto out_zero;
2502 }
2503 memset(repl, 0, sizeof(*repl) + new_size);
2505 #if 0
2506 TC_DUMP_ENTRIES(*handle);
2507 #endif
2509 counterlen = sizeof(STRUCT_COUNTERS_INFO)
2510 + sizeof(STRUCT_COUNTERS) * new_number;
2512 /* These are the old counters we will get from kernel */
2513 repl->counters = malloc(sizeof(STRUCT_COUNTERS)
2514 * (*handle)->info.num_entries);
2515 if (!repl->counters) {
2516 errno = ENOMEM;
2517 goto out_free_repl;
2518 }
2519 /* These are the counters we're going to put back, later. */
2520 newcounters = malloc(counterlen);
2521 if (!newcounters) {
2522 errno = ENOMEM;
2523 goto out_free_repl_counters;
2524 }
2525 memset(newcounters, 0, counterlen);
2527 strcpy(repl->name, (*handle)->info.name);
2528 repl->num_entries = new_number;
2529 repl->size = new_size;
2531 repl->num_counters = (*handle)->info.num_entries;
2532 repl->valid_hooks = (*handle)->info.valid_hooks;
2534 DEBUGP("num_entries=%u, size=%u, num_counters=%u\n",
2535 repl->num_entries, repl->size, repl->num_counters);
2537 ret = iptcc_compile_table(*handle, repl);
2538 if (ret < 0) {
2539 errno = ret;
2540 goto out_free_newcounters;
2541 }
2544 #ifdef IPTC_DEBUG2
2545 {
2546 int fd = open("/tmp/libiptc-so_set_replace.blob",
2547 O_CREAT|O_WRONLY);
2548 if (fd >= 0) {
2549 write(fd, repl, sizeof(*repl) + repl->size);
2550 close(fd);
2551 }
2552 }
2553 #endif
2555 ret = setsockopt(sockfd, TC_IPPROTO, SO_SET_REPLACE, repl,
2556 sizeof(*repl) + repl->size);
2557 if (ret < 0)
2558 goto out_free_newcounters;
2560 /* Put counters back. */
2561 strcpy(newcounters->name, (*handle)->info.name);
2562 newcounters->num_counters = new_number;
2564 list_for_each_entry(c, &(*handle)->chains, list) {
2565 struct rule_head *r;
2567 /* Builtin chains have their own counters */
2568 if (iptcc_is_builtin(c)) {
2569 DEBUGP("counter for chain-index %u: ", c->foot_index);
2570 switch(c->counter_map.maptype) {
2571 case COUNTER_MAP_NOMAP:
2572 counters_nomap(newcounters, c->foot_index);
2573 break;
2574 case COUNTER_MAP_NORMAL_MAP:
2575 counters_normal_map(newcounters, repl,
2576 c->foot_index,
2577 c->counter_map.mappos);
2578 break;
2579 case COUNTER_MAP_ZEROED:
2580 counters_map_zeroed(newcounters, repl,
2581 c->foot_index,
2582 c->counter_map.mappos,
2583 &c->counters);
2584 break;
2585 case COUNTER_MAP_SET:
2586 counters_map_set(newcounters, c->foot_index,
2587 &c->counters);
2588 break;
2589 }
2590 }
2592 list_for_each_entry(r, &c->rules, list) {
2593 DEBUGP("counter for index %u: ", r->index);
2594 switch (r->counter_map.maptype) {
2595 case COUNTER_MAP_NOMAP:
2596 counters_nomap(newcounters, r->index);
2597 break;
2599 case COUNTER_MAP_NORMAL_MAP:
2600 counters_normal_map(newcounters, repl,
2601 r->index,
2602 r->counter_map.mappos);
2603 break;
2605 case COUNTER_MAP_ZEROED:
2606 counters_map_zeroed(newcounters, repl,
2607 r->index,
2608 r->counter_map.mappos,
2609 &r->entry->counters);
2610 break;
2612 case COUNTER_MAP_SET:
2613 counters_map_set(newcounters, r->index,
2614 &r->entry->counters);
2615 break;
2616 }
2617 }
2618 }
2620 #ifdef IPTC_DEBUG2
2621 {
2622 int fd = open("/tmp/libiptc-so_set_add_counters.blob",
2623 O_CREAT|O_WRONLY);
2624 if (fd >= 0) {
2625 write(fd, newcounters, counterlen);
2626 close(fd);
2627 }
2628 }
2629 #endif
2631 ret = setsockopt(sockfd, TC_IPPROTO, SO_SET_ADD_COUNTERS,
2632 newcounters, counterlen);
2633 if (ret < 0)
2634 goto out_free_newcounters;
2636 free(repl->counters);
2637 free(repl);
2638 free(newcounters);
2640 finished:
2641 TC_FREE(handle);
2642 return 1;
2644 out_free_newcounters:
2645 free(newcounters);
2646 out_free_repl_counters:
2647 free(repl->counters);
2648 out_free_repl:
2649 free(repl);
2650 out_zero:
2651 return 0;
2652 }
2654 /* Get raw socket. */
2655 int
2656 TC_GET_RAW_SOCKET(void)
2657 {
2658 return sockfd;
2659 }
2661 /* Translates errno numbers into more human-readable form than strerror. */
2662 const char *
2663 TC_STRERROR(int err)
2664 {
2665 unsigned int i;
2666 struct table_struct {
2667 void *fn;
2668 int err;
2669 const char *message;
2670 } table [] =
2671 { { TC_INIT, EPERM, "Permission denied (you must be root)" },
2672 { TC_INIT, EINVAL, "Module is wrong version" },
2673 { TC_INIT, ENOENT,
2674 "Table does not exist (do you need to insmod?)" },
2675 { TC_DELETE_CHAIN, ENOTEMPTY, "Chain is not empty" },
2676 { TC_DELETE_CHAIN, EINVAL, "Can't delete built-in chain" },
2677 { TC_DELETE_CHAIN, EMLINK,
2678 "Can't delete chain with references left" },
2679 { TC_CREATE_CHAIN, EEXIST, "Chain already exists" },
2680 { TC_INSERT_ENTRY, E2BIG, "Index of insertion too big" },
2681 { TC_REPLACE_ENTRY, E2BIG, "Index of replacement too big" },
2682 { TC_DELETE_NUM_ENTRY, E2BIG, "Index of deletion too big" },
2683 { TC_READ_COUNTER, E2BIG, "Index of counter too big" },
2684 { TC_ZERO_COUNTER, E2BIG, "Index of counter too big" },
2685 { TC_INSERT_ENTRY, ELOOP, "Loop found in table" },
2686 { TC_INSERT_ENTRY, EINVAL, "Target problem" },
2687 /* EINVAL for CHECK probably means bad interface. */
2688 { TC_CHECK_PACKET, EINVAL,
2689 "Bad arguments (does that interface exist?)" },
2690 { TC_CHECK_PACKET, ENOSYS,
2691 "Checking will most likely never get implemented" },
2692 /* ENOENT for DELETE probably means no matching rule */
2693 { TC_DELETE_ENTRY, ENOENT,
2694 "Bad rule (does a matching rule exist in that chain?)" },
2695 { TC_SET_POLICY, ENOENT,
2696 "Bad built-in chain name" },
2697 { TC_SET_POLICY, EINVAL,
2698 "Bad policy name" },
2700 { NULL, 0, "Incompatible with this kernel" },
2701 { NULL, ENOPROTOOPT, "iptables who? (do you need to insmod?)" },
2702 { NULL, ENOSYS, "Will be implemented real soon. I promise ;)" },
2703 { NULL, ENOMEM, "Memory allocation problem" },
2704 { NULL, ENOENT, "No chain/target/match by that name" },
2705 };
2707 for (i = 0; i < sizeof(table)/sizeof(struct table_struct); i++) {
2708 if ((!table[i].fn || table[i].fn == iptc_fn)
2709 && table[i].err == err)
2710 return table[i].message;
2711 }
2713 return strerror(err);
2714 }