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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux...
[linux/fpc-iii.git] / net / bridge / netfilter / ebtables.c
blob5a61f35412a0595845da4feb2cbd0bc09a1cdbeb
1 /*
2 * ebtables
3 *
4 * Author:
5 * Bart De Schuymer <bdschuym@pandora.be>
6 *
7 * ebtables.c,v 2.0, July, 2002
8 *
9 * This code is strongly inspired by the iptables code which is
10 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/kmod.h>
19 #include <linux/module.h>
20 #include <linux/vmalloc.h>
21 #include <linux/netfilter/x_tables.h>
22 #include <linux/netfilter_bridge/ebtables.h>
23 #include <linux/spinlock.h>
24 #include <linux/mutex.h>
25 #include <linux/slab.h>
26 #include <asm/uaccess.h>
27 #include <linux/smp.h>
28 #include <linux/cpumask.h>
29 #include <linux/audit.h>
30 #include <net/sock.h>
31 /* needed for logical [in,out]-dev filtering */
32 #include "../br_private.h"
33
34 #define BUGPRINT(format, args...) printk("kernel msg: ebtables bug: please "\
35 "report to author: "format, ## args)
36 /* #define BUGPRINT(format, args...) */
37
38 /* Each cpu has its own set of counters, so there is no need for write_lock in
39 * the softirq
40 * For reading or updating the counters, the user context needs to
41 * get a write_lock
42 */
43
44 /* The size of each set of counters is altered to get cache alignment */
45 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
46 #define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter)))
47 #define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \
48 COUNTER_OFFSET(n) * cpu))
49
50
51
52 static DEFINE_MUTEX(ebt_mutex);
53
54 #ifdef CONFIG_COMPAT
55 static void ebt_standard_compat_from_user(void *dst, const void *src)
56 {
57 int v = *(compat_int_t *)src;
58
59 if (v >= 0)
60 v += xt_compat_calc_jump(NFPROTO_BRIDGE, v);
61 memcpy(dst, &v, sizeof(v));
62 }
63
64 static int ebt_standard_compat_to_user(void __user *dst, const void *src)
65 {
66 compat_int_t cv = *(int *)src;
67
68 if (cv >= 0)
69 cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv);
70 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
71 }
72 #endif
73
74
75 static struct xt_target ebt_standard_target = {
76 .name = "standard",
77 .revision = 0,
78 .family = NFPROTO_BRIDGE,
79 .targetsize = sizeof(int),
80 #ifdef CONFIG_COMPAT
81 .compatsize = sizeof(compat_int_t),
82 .compat_from_user = ebt_standard_compat_from_user,
83 .compat_to_user = ebt_standard_compat_to_user,
84 #endif
85 };
86
87 static inline int
88 ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb,
89 struct xt_action_param *par)
90 {
91 par->target = w->u.watcher;
92 par->targinfo = w->data;
93 w->u.watcher->target(skb, par);
94 /* watchers don't give a verdict */
95 return 0;
96 }
97
98 static inline int
99 ebt_do_match(struct ebt_entry_match *m, const struct sk_buff *skb,
100 struct xt_action_param *par)
101 {
102 par->match = m->u.match;
103 par->matchinfo = m->data;
104 return m->u.match->match(skb, par) ? EBT_MATCH : EBT_NOMATCH;
105 }
106
107 static inline int
108 ebt_dev_check(const char *entry, const struct net_device *device)
109 {
110 int i = 0;
111 const char *devname;
112
113 if (*entry == '\0')
114 return 0;
115 if (!device)
116 return 1;
117 devname = device->name;
118 /* 1 is the wildcard token */
119 while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i])
120 i++;
121 return devname[i] != entry[i] && entry[i] != 1;
122 }
123
124 #define FWINV2(bool, invflg) ((bool) ^ !!(e->invflags & invflg))
125 /* process standard matches */
126 static inline int
127 ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb,
128 const struct net_device *in, const struct net_device *out)
129 {
130 const struct ethhdr *h = eth_hdr(skb);
131 const struct net_bridge_port *p;
132 __be16 ethproto;
133 int verdict, i;
134
135 if (skb_vlan_tag_present(skb))
136 ethproto = htons(ETH_P_8021Q);
137 else
138 ethproto = h->h_proto;
139
140 if (e->bitmask & EBT_802_3) {
141 if (FWINV2(eth_proto_is_802_3(ethproto), EBT_IPROTO))
142 return 1;
143 } else if (!(e->bitmask & EBT_NOPROTO) &&
144 FWINV2(e->ethproto != ethproto, EBT_IPROTO))
145 return 1;
146
147 if (FWINV2(ebt_dev_check(e->in, in), EBT_IIN))
148 return 1;
149 if (FWINV2(ebt_dev_check(e->out, out), EBT_IOUT))
150 return 1;
151 /* rcu_read_lock()ed by nf_hook_slow */
152 if (in && (p = br_port_get_rcu(in)) != NULL &&
153 FWINV2(ebt_dev_check(e->logical_in, p->br->dev), EBT_ILOGICALIN))
154 return 1;
155 if (out && (p = br_port_get_rcu(out)) != NULL &&
156 FWINV2(ebt_dev_check(e->logical_out, p->br->dev), EBT_ILOGICALOUT))
157 return 1;
158
159 if (e->bitmask & EBT_SOURCEMAC) {
160 verdict = 0;
161 for (i = 0; i < 6; i++)
162 verdict |= (h->h_source[i] ^ e->sourcemac[i]) &
163 e->sourcemsk[i];
164 if (FWINV2(verdict != 0, EBT_ISOURCE))
165 return 1;
166 }
167 if (e->bitmask & EBT_DESTMAC) {
168 verdict = 0;
169 for (i = 0; i < 6; i++)
170 verdict |= (h->h_dest[i] ^ e->destmac[i]) &
171 e->destmsk[i];
172 if (FWINV2(verdict != 0, EBT_IDEST))
173 return 1;
174 }
175 return 0;
176 }
177
178 static inline
179 struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry)
180 {
181 return (void *)entry + entry->next_offset;
182 }
183
184 /* Do some firewalling */
185 unsigned int ebt_do_table(struct sk_buff *skb,
186 const struct nf_hook_state *state,
187 struct ebt_table *table)
188 {
189 unsigned int hook = state->hook;
190 int i, nentries;
191 struct ebt_entry *point;
192 struct ebt_counter *counter_base, *cb_base;
193 const struct ebt_entry_target *t;
194 int verdict, sp = 0;
195 struct ebt_chainstack *cs;
196 struct ebt_entries *chaininfo;
197 const char *base;
198 const struct ebt_table_info *private;
199 struct xt_action_param acpar;
200
201 acpar.family = NFPROTO_BRIDGE;
202 acpar.net = state->net;
203 acpar.in = state->in;
204 acpar.out = state->out;
205 acpar.hotdrop = false;
206 acpar.hooknum = hook;
207
208 read_lock_bh(&table->lock);
209 private = table->private;
210 cb_base = COUNTER_BASE(private->counters, private->nentries,
211 smp_processor_id());
212 if (private->chainstack)
213 cs = private->chainstack[smp_processor_id()];
214 else
215 cs = NULL;
216 chaininfo = private->hook_entry[hook];
217 nentries = private->hook_entry[hook]->nentries;
218 point = (struct ebt_entry *)(private->hook_entry[hook]->data);
219 counter_base = cb_base + private->hook_entry[hook]->counter_offset;
220 /* base for chain jumps */
221 base = private->entries;
222 i = 0;
223 while (i < nentries) {
224 if (ebt_basic_match(point, skb, state->in, state->out))
225 goto letscontinue;
226
227 if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0)
228 goto letscontinue;
229 if (acpar.hotdrop) {
230 read_unlock_bh(&table->lock);
231 return NF_DROP;
232 }
233
234 /* increase counter */
235 (*(counter_base + i)).pcnt++;
236 (*(counter_base + i)).bcnt += skb->len;
237
238 /* these should only watch: not modify, nor tell us
239 * what to do with the packet
240 */
241 EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar);
242
243 t = (struct ebt_entry_target *)
244 (((char *)point) + point->target_offset);
245 /* standard target */
246 if (!t->u.target->target)
247 verdict = ((struct ebt_standard_target *)t)->verdict;
248 else {
249 acpar.target = t->u.target;
250 acpar.targinfo = t->data;
251 verdict = t->u.target->target(skb, &acpar);
252 }
253 if (verdict == EBT_ACCEPT) {
254 read_unlock_bh(&table->lock);
255 return NF_ACCEPT;
256 }
257 if (verdict == EBT_DROP) {
258 read_unlock_bh(&table->lock);
259 return NF_DROP;
260 }
261 if (verdict == EBT_RETURN) {
262 letsreturn:
263 #ifdef CONFIG_NETFILTER_DEBUG
264 if (sp == 0) {
265 BUGPRINT("RETURN on base chain");
266 /* act like this is EBT_CONTINUE */
267 goto letscontinue;
268 }
269 #endif
270 sp--;
271 /* put all the local variables right */
272 i = cs[sp].n;
273 chaininfo = cs[sp].chaininfo;
274 nentries = chaininfo->nentries;
275 point = cs[sp].e;
276 counter_base = cb_base +
277 chaininfo->counter_offset;
278 continue;
279 }
280 if (verdict == EBT_CONTINUE)
281 goto letscontinue;
282 #ifdef CONFIG_NETFILTER_DEBUG
283 if (verdict < 0) {
284 BUGPRINT("bogus standard verdict\n");
285 read_unlock_bh(&table->lock);
286 return NF_DROP;
287 }
288 #endif
289 /* jump to a udc */
290 cs[sp].n = i + 1;
291 cs[sp].chaininfo = chaininfo;
292 cs[sp].e = ebt_next_entry(point);
293 i = 0;
294 chaininfo = (struct ebt_entries *) (base + verdict);
295 #ifdef CONFIG_NETFILTER_DEBUG
296 if (chaininfo->distinguisher) {
297 BUGPRINT("jump to non-chain\n");
298 read_unlock_bh(&table->lock);
299 return NF_DROP;
300 }
301 #endif
302 nentries = chaininfo->nentries;
303 point = (struct ebt_entry *)chaininfo->data;
304 counter_base = cb_base + chaininfo->counter_offset;
305 sp++;
306 continue;
307 letscontinue:
308 point = ebt_next_entry(point);
309 i++;
310 }
311
312 /* I actually like this :) */
313 if (chaininfo->policy == EBT_RETURN)
314 goto letsreturn;
315 if (chaininfo->policy == EBT_ACCEPT) {
316 read_unlock_bh(&table->lock);
317 return NF_ACCEPT;
318 }
319 read_unlock_bh(&table->lock);
320 return NF_DROP;
321 }
322
323 /* If it succeeds, returns element and locks mutex */
324 static inline void *
325 find_inlist_lock_noload(struct list_head *head, const char *name, int *error,
326 struct mutex *mutex)
327 {
328 struct {
329 struct list_head list;
330 char name[EBT_FUNCTION_MAXNAMELEN];
331 } *e;
332
333 mutex_lock(mutex);
334 list_for_each_entry(e, head, list) {
335 if (strcmp(e->name, name) == 0)
336 return e;
337 }
338 *error = -ENOENT;
339 mutex_unlock(mutex);
340 return NULL;
341 }
342
343 static void *
344 find_inlist_lock(struct list_head *head, const char *name, const char *prefix,
345 int *error, struct mutex *mutex)
346 {
347 return try_then_request_module(
348 find_inlist_lock_noload(head, name, error, mutex),
349 "%s%s", prefix, name);
350 }
351
352 static inline struct ebt_table *
353 find_table_lock(struct net *net, const char *name, int *error,
354 struct mutex *mutex)
355 {
356 return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name,
357 "ebtable_", error, mutex);
358 }
359
360 static inline int
361 ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
362 unsigned int *cnt)
363 {
364 const struct ebt_entry *e = par->entryinfo;
365 struct xt_match *match;
366 size_t left = ((char *)e + e->watchers_offset) - (char *)m;
367 int ret;
368
369 if (left < sizeof(struct ebt_entry_match) ||
370 left - sizeof(struct ebt_entry_match) < m->match_size)
371 return -EINVAL;
372
373 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, 0);
374 if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) {
375 request_module("ebt_%s", m->u.name);
376 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, 0);
377 }
378 if (IS_ERR(match))
379 return PTR_ERR(match);
380 m->u.match = match;
381
382 par->match = match;
383 par->matchinfo = m->data;
384 ret = xt_check_match(par, m->match_size,
385 e->ethproto, e->invflags & EBT_IPROTO);
386 if (ret < 0) {
387 module_put(match->me);
388 return ret;
389 }
390
391 (*cnt)++;
392 return 0;
393 }
394
395 static inline int
396 ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
397 unsigned int *cnt)
398 {
399 const struct ebt_entry *e = par->entryinfo;
400 struct xt_target *watcher;
401 size_t left = ((char *)e + e->target_offset) - (char *)w;
402 int ret;
403
404 if (left < sizeof(struct ebt_entry_watcher) ||
405 left - sizeof(struct ebt_entry_watcher) < w->watcher_size)
406 return -EINVAL;
407
408 watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0);
409 if (IS_ERR(watcher))
410 return PTR_ERR(watcher);
411 w->u.watcher = watcher;
412
413 par->target = watcher;
414 par->targinfo = w->data;
415 ret = xt_check_target(par, w->watcher_size,
416 e->ethproto, e->invflags & EBT_IPROTO);
417 if (ret < 0) {
418 module_put(watcher->me);
419 return ret;
420 }
421
422 (*cnt)++;
423 return 0;
424 }
425
426 static int ebt_verify_pointers(const struct ebt_replace *repl,
427 struct ebt_table_info *newinfo)
428 {
429 unsigned int limit = repl->entries_size;
430 unsigned int valid_hooks = repl->valid_hooks;
431 unsigned int offset = 0;
432 int i;
433
434 for (i = 0; i < NF_BR_NUMHOOKS; i++)
435 newinfo->hook_entry[i] = NULL;
436
437 newinfo->entries_size = repl->entries_size;
438 newinfo->nentries = repl->nentries;
439
440 while (offset < limit) {
441 size_t left = limit - offset;
442 struct ebt_entry *e = (void *)newinfo->entries + offset;
443
444 if (left < sizeof(unsigned int))
445 break;
446
447 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
448 if ((valid_hooks & (1 << i)) == 0)
449 continue;
450 if ((char __user *)repl->hook_entry[i] ==
451 repl->entries + offset)
452 break;
453 }
454
455 if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
456 if (e->bitmask != 0) {
457 /* we make userspace set this right,
458 * so there is no misunderstanding
459 */
460 BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set "
461 "in distinguisher\n");
462 return -EINVAL;
463 }
464 if (i != NF_BR_NUMHOOKS)
465 newinfo->hook_entry[i] = (struct ebt_entries *)e;
466 if (left < sizeof(struct ebt_entries))
467 break;
468 offset += sizeof(struct ebt_entries);
469 } else {
470 if (left < sizeof(struct ebt_entry))
471 break;
472 if (left < e->next_offset)
473 break;
474 if (e->next_offset < sizeof(struct ebt_entry))
475 return -EINVAL;
476 offset += e->next_offset;
477 }
478 }
479 if (offset != limit) {
480 BUGPRINT("entries_size too small\n");
481 return -EINVAL;
482 }
483
484 /* check if all valid hooks have a chain */
485 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
486 if (!newinfo->hook_entry[i] &&
487 (valid_hooks & (1 << i))) {
488 BUGPRINT("Valid hook without chain\n");
489 return -EINVAL;
490 }
491 }
492 return 0;
493 }
494
495 /* this one is very careful, as it is the first function
496 * to parse the userspace data
497 */
498 static inline int
499 ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
500 const struct ebt_table_info *newinfo,
501 unsigned int *n, unsigned int *cnt,
502 unsigned int *totalcnt, unsigned int *udc_cnt)
503 {
504 int i;
505
506 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
507 if ((void *)e == (void *)newinfo->hook_entry[i])
508 break;
509 }
510 /* beginning of a new chain
511 * if i == NF_BR_NUMHOOKS it must be a user defined chain
512 */
513 if (i != NF_BR_NUMHOOKS || !e->bitmask) {
514 /* this checks if the previous chain has as many entries
515 * as it said it has
516 */
517 if (*n != *cnt) {
518 BUGPRINT("nentries does not equal the nr of entries "
519 "in the chain\n");
520 return -EINVAL;
521 }
522 if (((struct ebt_entries *)e)->policy != EBT_DROP &&
523 ((struct ebt_entries *)e)->policy != EBT_ACCEPT) {
524 /* only RETURN from udc */
525 if (i != NF_BR_NUMHOOKS ||
526 ((struct ebt_entries *)e)->policy != EBT_RETURN) {
527 BUGPRINT("bad policy\n");
528 return -EINVAL;
529 }
530 }
531 if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */
532 (*udc_cnt)++;
533 if (((struct ebt_entries *)e)->counter_offset != *totalcnt) {
534 BUGPRINT("counter_offset != totalcnt");
535 return -EINVAL;
536 }
537 *n = ((struct ebt_entries *)e)->nentries;
538 *cnt = 0;
539 return 0;
540 }
541 /* a plain old entry, heh */
542 if (sizeof(struct ebt_entry) > e->watchers_offset ||
543 e->watchers_offset > e->target_offset ||
544 e->target_offset >= e->next_offset) {
545 BUGPRINT("entry offsets not in right order\n");
546 return -EINVAL;
547 }
548 /* this is not checked anywhere else */
549 if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target)) {
550 BUGPRINT("target size too small\n");
551 return -EINVAL;
552 }
553 (*cnt)++;
554 (*totalcnt)++;
555 return 0;
556 }
557
558 struct ebt_cl_stack {
559 struct ebt_chainstack cs;
560 int from;
561 unsigned int hookmask;
562 };
563
564 /* We need these positions to check that the jumps to a different part of the
565 * entries is a jump to the beginning of a new chain.
566 */
567 static inline int
568 ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo,
569 unsigned int *n, struct ebt_cl_stack *udc)
570 {
571 int i;
572
573 /* we're only interested in chain starts */
574 if (e->bitmask)
575 return 0;
576 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
577 if (newinfo->hook_entry[i] == (struct ebt_entries *)e)
578 break;
579 }
580 /* only care about udc */
581 if (i != NF_BR_NUMHOOKS)
582 return 0;
583
584 udc[*n].cs.chaininfo = (struct ebt_entries *)e;
585 /* these initialisations are depended on later in check_chainloops() */
586 udc[*n].cs.n = 0;
587 udc[*n].hookmask = 0;
588
589 (*n)++;
590 return 0;
591 }
592
593 static inline int
594 ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i)
595 {
596 struct xt_mtdtor_param par;
597
598 if (i && (*i)-- == 0)
599 return 1;
600
601 par.net = net;
602 par.match = m->u.match;
603 par.matchinfo = m->data;
604 par.family = NFPROTO_BRIDGE;
605 if (par.match->destroy != NULL)
606 par.match->destroy(&par);
607 module_put(par.match->me);
608 return 0;
609 }
610
611 static inline int
612 ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i)
613 {
614 struct xt_tgdtor_param par;
615
616 if (i && (*i)-- == 0)
617 return 1;
618
619 par.net = net;
620 par.target = w->u.watcher;
621 par.targinfo = w->data;
622 par.family = NFPROTO_BRIDGE;
623 if (par.target->destroy != NULL)
624 par.target->destroy(&par);
625 module_put(par.target->me);
626 return 0;
627 }
628
629 static inline int
630 ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
631 {
632 struct xt_tgdtor_param par;
633 struct ebt_entry_target *t;
634
635 if (e->bitmask == 0)
636 return 0;
637 /* we're done */
638 if (cnt && (*cnt)-- == 0)
639 return 1;
640 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL);
641 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL);
642 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
643
644 par.net = net;
645 par.target = t->u.target;
646 par.targinfo = t->data;
647 par.family = NFPROTO_BRIDGE;
648 if (par.target->destroy != NULL)
649 par.target->destroy(&par);
650 module_put(par.target->me);
651 return 0;
652 }
653
654 static inline int
655 ebt_check_entry(struct ebt_entry *e, struct net *net,
656 const struct ebt_table_info *newinfo,
657 const char *name, unsigned int *cnt,
658 struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
659 {
660 struct ebt_entry_target *t;
661 struct xt_target *target;
662 unsigned int i, j, hook = 0, hookmask = 0;
663 size_t gap;
664 int ret;
665 struct xt_mtchk_param mtpar;
666 struct xt_tgchk_param tgpar;
667
668 /* don't mess with the struct ebt_entries */
669 if (e->bitmask == 0)
670 return 0;
671
672 if (e->bitmask & ~EBT_F_MASK) {
673 BUGPRINT("Unknown flag for bitmask\n");
674 return -EINVAL;
675 }
676 if (e->invflags & ~EBT_INV_MASK) {
677 BUGPRINT("Unknown flag for inv bitmask\n");
678 return -EINVAL;
679 }
680 if ((e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3)) {
681 BUGPRINT("NOPROTO & 802_3 not allowed\n");
682 return -EINVAL;
683 }
684 /* what hook do we belong to? */
685 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
686 if (!newinfo->hook_entry[i])
687 continue;
688 if ((char *)newinfo->hook_entry[i] < (char *)e)
689 hook = i;
690 else
691 break;
692 }
693 /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on
694 * a base chain
695 */
696 if (i < NF_BR_NUMHOOKS)
697 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
698 else {
699 for (i = 0; i < udc_cnt; i++)
700 if ((char *)(cl_s[i].cs.chaininfo) > (char *)e)
701 break;
702 if (i == 0)
703 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
704 else
705 hookmask = cl_s[i - 1].hookmask;
706 }
707 i = 0;
708
709 mtpar.net = tgpar.net = net;
710 mtpar.table = tgpar.table = name;
711 mtpar.entryinfo = tgpar.entryinfo = e;
712 mtpar.hook_mask = tgpar.hook_mask = hookmask;
713 mtpar.family = tgpar.family = NFPROTO_BRIDGE;
714 ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i);
715 if (ret != 0)
716 goto cleanup_matches;
717 j = 0;
718 ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j);
719 if (ret != 0)
720 goto cleanup_watchers;
721 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
722 gap = e->next_offset - e->target_offset;
723
724 target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0);
725 if (IS_ERR(target)) {
726 ret = PTR_ERR(target);
727 goto cleanup_watchers;
728 }
729
730 t->u.target = target;
731 if (t->u.target == &ebt_standard_target) {
732 if (gap < sizeof(struct ebt_standard_target)) {
733 BUGPRINT("Standard target size too big\n");
734 ret = -EFAULT;
735 goto cleanup_watchers;
736 }
737 if (((struct ebt_standard_target *)t)->verdict <
738 -NUM_STANDARD_TARGETS) {
739 BUGPRINT("Invalid standard target\n");
740 ret = -EFAULT;
741 goto cleanup_watchers;
742 }
743 } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) {
744 module_put(t->u.target->me);
745 ret = -EFAULT;
746 goto cleanup_watchers;
747 }
748
749 tgpar.target = target;
750 tgpar.targinfo = t->data;
751 ret = xt_check_target(&tgpar, t->target_size,
752 e->ethproto, e->invflags & EBT_IPROTO);
753 if (ret < 0) {
754 module_put(target->me);
755 goto cleanup_watchers;
756 }
757 (*cnt)++;
758 return 0;
759 cleanup_watchers:
760 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j);
761 cleanup_matches:
762 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i);
763 return ret;
764 }
765
766 /* checks for loops and sets the hook mask for udc
767 * the hook mask for udc tells us from which base chains the udc can be
768 * accessed. This mask is a parameter to the check() functions of the extensions
769 */
770 static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
771 unsigned int udc_cnt, unsigned int hooknr, char *base)
772 {
773 int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
774 const struct ebt_entry *e = (struct ebt_entry *)chain->data;
775 const struct ebt_entry_target *t;
776
777 while (pos < nentries || chain_nr != -1) {
778 /* end of udc, go back one 'recursion' step */
779 if (pos == nentries) {
780 /* put back values of the time when this chain was called */
781 e = cl_s[chain_nr].cs.e;
782 if (cl_s[chain_nr].from != -1)
783 nentries =
784 cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries;
785 else
786 nentries = chain->nentries;
787 pos = cl_s[chain_nr].cs.n;
788 /* make sure we won't see a loop that isn't one */
789 cl_s[chain_nr].cs.n = 0;
790 chain_nr = cl_s[chain_nr].from;
791 if (pos == nentries)
792 continue;
793 }
794 t = (struct ebt_entry_target *)
795 (((char *)e) + e->target_offset);
796 if (strcmp(t->u.name, EBT_STANDARD_TARGET))
797 goto letscontinue;
798 if (e->target_offset + sizeof(struct ebt_standard_target) >
799 e->next_offset) {
800 BUGPRINT("Standard target size too big\n");
801 return -1;
802 }
803 verdict = ((struct ebt_standard_target *)t)->verdict;
804 if (verdict >= 0) { /* jump to another chain */
805 struct ebt_entries *hlp2 =
806 (struct ebt_entries *)(base + verdict);
807 for (i = 0; i < udc_cnt; i++)
808 if (hlp2 == cl_s[i].cs.chaininfo)
809 break;
810 /* bad destination or loop */
811 if (i == udc_cnt) {
812 BUGPRINT("bad destination\n");
813 return -1;
814 }
815 if (cl_s[i].cs.n) {
816 BUGPRINT("loop\n");
817 return -1;
818 }
819 if (cl_s[i].hookmask & (1 << hooknr))
820 goto letscontinue;
821 /* this can't be 0, so the loop test is correct */
822 cl_s[i].cs.n = pos + 1;
823 pos = 0;
824 cl_s[i].cs.e = ebt_next_entry(e);
825 e = (struct ebt_entry *)(hlp2->data);
826 nentries = hlp2->nentries;
827 cl_s[i].from = chain_nr;
828 chain_nr = i;
829 /* this udc is accessible from the base chain for hooknr */
830 cl_s[i].hookmask |= (1 << hooknr);
831 continue;
832 }
833 letscontinue:
834 e = ebt_next_entry(e);
835 pos++;
836 }
837 return 0;
838 }
839
840 /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
841 static int translate_table(struct net *net, const char *name,
842 struct ebt_table_info *newinfo)
843 {
844 unsigned int i, j, k, udc_cnt;
845 int ret;
846 struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */
847
848 i = 0;
849 while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i])
850 i++;
851 if (i == NF_BR_NUMHOOKS) {
852 BUGPRINT("No valid hooks specified\n");
853 return -EINVAL;
854 }
855 if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) {
856 BUGPRINT("Chains don't start at beginning\n");
857 return -EINVAL;
858 }
859 /* make sure chains are ordered after each other in same order
860 * as their corresponding hooks
861 */
862 for (j = i + 1; j < NF_BR_NUMHOOKS; j++) {
863 if (!newinfo->hook_entry[j])
864 continue;
865 if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) {
866 BUGPRINT("Hook order must be followed\n");
867 return -EINVAL;
868 }
869 i = j;
870 }
871
872 /* do some early checkings and initialize some things */
873 i = 0; /* holds the expected nr. of entries for the chain */
874 j = 0; /* holds the up to now counted entries for the chain */
875 k = 0; /* holds the total nr. of entries, should equal
876 * newinfo->nentries afterwards
877 */
878 udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */
879 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
880 ebt_check_entry_size_and_hooks, newinfo,
881 &i, &j, &k, &udc_cnt);
882
883 if (ret != 0)
884 return ret;
885
886 if (i != j) {
887 BUGPRINT("nentries does not equal the nr of entries in the "
888 "(last) chain\n");
889 return -EINVAL;
890 }
891 if (k != newinfo->nentries) {
892 BUGPRINT("Total nentries is wrong\n");
893 return -EINVAL;
894 }
895
896 /* get the location of the udc, put them in an array
897 * while we're at it, allocate the chainstack
898 */
899 if (udc_cnt) {
900 /* this will get free'd in do_replace()/ebt_register_table()
901 * if an error occurs
902 */
903 newinfo->chainstack =
904 vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack)));
905 if (!newinfo->chainstack)
906 return -ENOMEM;
907 for_each_possible_cpu(i) {
908 newinfo->chainstack[i] =
909 vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0])));
910 if (!newinfo->chainstack[i]) {
911 while (i)
912 vfree(newinfo->chainstack[--i]);
913 vfree(newinfo->chainstack);
914 newinfo->chainstack = NULL;
915 return -ENOMEM;
916 }
917 }
918
919 cl_s = vmalloc(udc_cnt * sizeof(*cl_s));
920 if (!cl_s)
921 return -ENOMEM;
922 i = 0; /* the i'th udc */
923 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
924 ebt_get_udc_positions, newinfo, &i, cl_s);
925 /* sanity check */
926 if (i != udc_cnt) {
927 BUGPRINT("i != udc_cnt\n");
928 vfree(cl_s);
929 return -EFAULT;
930 }
931 }
932
933 /* Check for loops */
934 for (i = 0; i < NF_BR_NUMHOOKS; i++)
935 if (newinfo->hook_entry[i])
936 if (check_chainloops(newinfo->hook_entry[i],
937 cl_s, udc_cnt, i, newinfo->entries)) {
938 vfree(cl_s);
939 return -EINVAL;
940 }
941
942 /* we now know the following (along with E=mc²):
943 * - the nr of entries in each chain is right
944 * - the size of the allocated space is right
945 * - all valid hooks have a corresponding chain
946 * - there are no loops
947 * - wrong data can still be on the level of a single entry
948 * - could be there are jumps to places that are not the
949 * beginning of a chain. This can only occur in chains that
950 * are not accessible from any base chains, so we don't care.
951 */
952
953 /* used to know what we need to clean up if something goes wrong */
954 i = 0;
955 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
956 ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt);
957 if (ret != 0) {
958 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
959 ebt_cleanup_entry, net, &i);
960 }
961 vfree(cl_s);
962 return ret;
963 }
964
965 /* called under write_lock */
966 static void get_counters(const struct ebt_counter *oldcounters,
967 struct ebt_counter *counters, unsigned int nentries)
968 {
969 int i, cpu;
970 struct ebt_counter *counter_base;
971
972 /* counters of cpu 0 */
973 memcpy(counters, oldcounters,
974 sizeof(struct ebt_counter) * nentries);
975
976 /* add other counters to those of cpu 0 */
977 for_each_possible_cpu(cpu) {
978 if (cpu == 0)
979 continue;
980 counter_base = COUNTER_BASE(oldcounters, nentries, cpu);
981 for (i = 0; i < nentries; i++) {
982 counters[i].pcnt += counter_base[i].pcnt;
983 counters[i].bcnt += counter_base[i].bcnt;
984 }
985 }
986 }
987
988 static int do_replace_finish(struct net *net, struct ebt_replace *repl,
989 struct ebt_table_info *newinfo)
990 {
991 int ret, i;
992 struct ebt_counter *counterstmp = NULL;
993 /* used to be able to unlock earlier */
994 struct ebt_table_info *table;
995 struct ebt_table *t;
996
997 /* the user wants counters back
998 * the check on the size is done later, when we have the lock
999 */
1000 if (repl->num_counters) {
1001 unsigned long size = repl->num_counters * sizeof(*counterstmp);
1002 counterstmp = vmalloc(size);
1003 if (!counterstmp)
1004 return -ENOMEM;
1005 }
1006
1007 newinfo->chainstack = NULL;
1008 ret = ebt_verify_pointers(repl, newinfo);
1009 if (ret != 0)
1010 goto free_counterstmp;
1011
1012 ret = translate_table(net, repl->name, newinfo);
1013
1014 if (ret != 0)
1015 goto free_counterstmp;
1016
1017 t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
1018 if (!t) {
1019 ret = -ENOENT;
1020 goto free_iterate;
1021 }
1022
1023 /* the table doesn't like it */
1024 if (t->check && (ret = t->check(newinfo, repl->valid_hooks)))
1025 goto free_unlock;
1026
1027 if (repl->num_counters && repl->num_counters != t->private->nentries) {
1028 BUGPRINT("Wrong nr. of counters requested\n");
1029 ret = -EINVAL;
1030 goto free_unlock;
1031 }
1032
1033 /* we have the mutex lock, so no danger in reading this pointer */
1034 table = t->private;
1035 /* make sure the table can only be rmmod'ed if it contains no rules */
1036 if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) {
1037 ret = -ENOENT;
1038 goto free_unlock;
1039 } else if (table->nentries && !newinfo->nentries)
1040 module_put(t->me);
1041 /* we need an atomic snapshot of the counters */
1042 write_lock_bh(&t->lock);
1043 if (repl->num_counters)
1044 get_counters(t->private->counters, counterstmp,
1045 t->private->nentries);
1046
1047 t->private = newinfo;
1048 write_unlock_bh(&t->lock);
1049 mutex_unlock(&ebt_mutex);
1050 /* so, a user can change the chains while having messed up her counter
1051 * allocation. Only reason why this is done is because this way the lock
1052 * is held only once, while this doesn't bring the kernel into a
1053 * dangerous state.
1054 */
1055 if (repl->num_counters &&
1056 copy_to_user(repl->counters, counterstmp,
1057 repl->num_counters * sizeof(struct ebt_counter))) {
1058 /* Silent error, can't fail, new table is already in place */
1059 net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n");
1060 }
1061
1062 /* decrease module count and free resources */
1063 EBT_ENTRY_ITERATE(table->entries, table->entries_size,
1064 ebt_cleanup_entry, net, NULL);
1065
1066 vfree(table->entries);
1067 if (table->chainstack) {
1068 for_each_possible_cpu(i)
1069 vfree(table->chainstack[i]);
1070 vfree(table->chainstack);
1071 }
1072 vfree(table);
1073
1074 vfree(counterstmp);
1075
1076 #ifdef CONFIG_AUDIT
1077 if (audit_enabled) {
1078 struct audit_buffer *ab;
1079
1080 ab = audit_log_start(current->audit_context, GFP_KERNEL,
1081 AUDIT_NETFILTER_CFG);
1082 if (ab) {
1083 audit_log_format(ab, "table=%s family=%u entries=%u",
1084 repl->name, AF_BRIDGE, repl->nentries);
1085 audit_log_end(ab);
1086 }
1087 }
1088 #endif
1089 return ret;
1090
1091 free_unlock:
1092 mutex_unlock(&ebt_mutex);
1093 free_iterate:
1094 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
1095 ebt_cleanup_entry, net, NULL);
1096 free_counterstmp:
1097 vfree(counterstmp);
1098 /* can be initialized in translate_table() */
1099 if (newinfo->chainstack) {
1100 for_each_possible_cpu(i)
1101 vfree(newinfo->chainstack[i]);
1102 vfree(newinfo->chainstack);
1103 }
1104 return ret;
1105 }
1106
1107 /* replace the table */
1108 static int do_replace(struct net *net, const void __user *user,
1109 unsigned int len)
1110 {
1111 int ret, countersize;
1112 struct ebt_table_info *newinfo;
1113 struct ebt_replace tmp;
1114
1115 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1116 return -EFAULT;
1117
1118 if (len != sizeof(tmp) + tmp.entries_size) {
1119 BUGPRINT("Wrong len argument\n");
1120 return -EINVAL;
1121 }
1122
1123 if (tmp.entries_size == 0) {
1124 BUGPRINT("Entries_size never zero\n");
1125 return -EINVAL;
1126 }
1127 /* overflow check */
1128 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
1129 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
1130 return -ENOMEM;
1131 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
1132 return -ENOMEM;
1133
1134 tmp.name[sizeof(tmp.name) - 1] = 0;
1135
1136 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
1137 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1138 if (!newinfo)
1139 return -ENOMEM;
1140
1141 if (countersize)
1142 memset(newinfo->counters, 0, countersize);
1143
1144 newinfo->entries = vmalloc(tmp.entries_size);
1145 if (!newinfo->entries) {
1146 ret = -ENOMEM;
1147 goto free_newinfo;
1148 }
1149 if (copy_from_user(
1150 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
1151 BUGPRINT("Couldn't copy entries from userspace\n");
1152 ret = -EFAULT;
1153 goto free_entries;
1154 }
1155
1156 ret = do_replace_finish(net, &tmp, newinfo);
1157 if (ret == 0)
1158 return ret;
1159 free_entries:
1160 vfree(newinfo->entries);
1161 free_newinfo:
1162 vfree(newinfo);
1163 return ret;
1164 }
1165
1166 struct ebt_table *
1167 ebt_register_table(struct net *net, const struct ebt_table *input_table)
1168 {
1169 struct ebt_table_info *newinfo;
1170 struct ebt_table *t, *table;
1171 struct ebt_replace_kernel *repl;
1172 int ret, i, countersize;
1173 void *p;
1174
1175 if (input_table == NULL || (repl = input_table->table) == NULL ||
1176 repl->entries == NULL || repl->entries_size == 0 ||
1177 repl->counters != NULL || input_table->private != NULL) {
1178 BUGPRINT("Bad table data for ebt_register_table!!!\n");
1179 return ERR_PTR(-EINVAL);
1180 }
1181
1182 /* Don't add one table to multiple lists. */
1183 table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL);
1184 if (!table) {
1185 ret = -ENOMEM;
1186 goto out;
1187 }
1188
1189 countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
1190 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1191 ret = -ENOMEM;
1192 if (!newinfo)
1193 goto free_table;
1194
1195 p = vmalloc(repl->entries_size);
1196 if (!p)
1197 goto free_newinfo;
1198
1199 memcpy(p, repl->entries, repl->entries_size);
1200 newinfo->entries = p;
1201
1202 newinfo->entries_size = repl->entries_size;
1203 newinfo->nentries = repl->nentries;
1204
1205 if (countersize)
1206 memset(newinfo->counters, 0, countersize);
1207
1208 /* fill in newinfo and parse the entries */
1209 newinfo->chainstack = NULL;
1210 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1211 if ((repl->valid_hooks & (1 << i)) == 0)
1212 newinfo->hook_entry[i] = NULL;
1213 else
1214 newinfo->hook_entry[i] = p +
1215 ((char *)repl->hook_entry[i] - repl->entries);
1216 }
1217 ret = translate_table(net, repl->name, newinfo);
1218 if (ret != 0) {
1219 BUGPRINT("Translate_table failed\n");
1220 goto free_chainstack;
1221 }
1222
1223 if (table->check && table->check(newinfo, table->valid_hooks)) {
1224 BUGPRINT("The table doesn't like its own initial data, lol\n");
1225 ret = -EINVAL;
1226 goto free_chainstack;
1227 }
1228
1229 table->private = newinfo;
1230 rwlock_init(&table->lock);
1231 mutex_lock(&ebt_mutex);
1232 list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
1233 if (strcmp(t->name, table->name) == 0) {
1234 ret = -EEXIST;
1235 BUGPRINT("Table name already exists\n");
1236 goto free_unlock;
1237 }
1238 }
1239
1240 /* Hold a reference count if the chains aren't empty */
1241 if (newinfo->nentries && !try_module_get(table->me)) {
1242 ret = -ENOENT;
1243 goto free_unlock;
1244 }
1245 list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
1246 mutex_unlock(&ebt_mutex);
1247 return table;
1248 free_unlock:
1249 mutex_unlock(&ebt_mutex);
1250 free_chainstack:
1251 if (newinfo->chainstack) {
1252 for_each_possible_cpu(i)
1253 vfree(newinfo->chainstack[i]);
1254 vfree(newinfo->chainstack);
1255 }
1256 vfree(newinfo->entries);
1257 free_newinfo:
1258 vfree(newinfo);
1259 free_table:
1260 kfree(table);
1261 out:
1262 return ERR_PTR(ret);
1263 }
1264
1265 void ebt_unregister_table(struct net *net, struct ebt_table *table)
1266 {
1267 int i;
1268
1269 if (!table) {
1270 BUGPRINT("Request to unregister NULL table!!!\n");
1271 return;
1272 }
1273 mutex_lock(&ebt_mutex);
1274 list_del(&table->list);
1275 mutex_unlock(&ebt_mutex);
1276 EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
1277 ebt_cleanup_entry, net, NULL);
1278 if (table->private->nentries)
1279 module_put(table->me);
1280 vfree(table->private->entries);
1281 if (table->private->chainstack) {
1282 for_each_possible_cpu(i)
1283 vfree(table->private->chainstack[i]);
1284 vfree(table->private->chainstack);
1285 }
1286 vfree(table->private);
1287 kfree(table);
1288 }
1289
1290 /* userspace just supplied us with counters */
1291 static int do_update_counters(struct net *net, const char *name,
1292 struct ebt_counter __user *counters,
1293 unsigned int num_counters,
1294 const void __user *user, unsigned int len)
1295 {
1296 int i, ret;
1297 struct ebt_counter *tmp;
1298 struct ebt_table *t;
1299
1300 if (num_counters == 0)
1301 return -EINVAL;
1302
1303 tmp = vmalloc(num_counters * sizeof(*tmp));
1304 if (!tmp)
1305 return -ENOMEM;
1306
1307 t = find_table_lock(net, name, &ret, &ebt_mutex);
1308 if (!t)
1309 goto free_tmp;
1310
1311 if (num_counters != t->private->nentries) {
1312 BUGPRINT("Wrong nr of counters\n");
1313 ret = -EINVAL;
1314 goto unlock_mutex;
1315 }
1316
1317 if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) {
1318 ret = -EFAULT;
1319 goto unlock_mutex;
1320 }
1321
1322 /* we want an atomic add of the counters */
1323 write_lock_bh(&t->lock);
1324
1325 /* we add to the counters of the first cpu */
1326 for (i = 0; i < num_counters; i++) {
1327 t->private->counters[i].pcnt += tmp[i].pcnt;
1328 t->private->counters[i].bcnt += tmp[i].bcnt;
1329 }
1330
1331 write_unlock_bh(&t->lock);
1332 ret = 0;
1333 unlock_mutex:
1334 mutex_unlock(&ebt_mutex);
1335 free_tmp:
1336 vfree(tmp);
1337 return ret;
1338 }
1339
1340 static int update_counters(struct net *net, const void __user *user,
1341 unsigned int len)
1342 {
1343 struct ebt_replace hlp;
1344
1345 if (copy_from_user(&hlp, user, sizeof(hlp)))
1346 return -EFAULT;
1347
1348 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
1349 return -EINVAL;
1350
1351 return do_update_counters(net, hlp.name, hlp.counters,
1352 hlp.num_counters, user, len);
1353 }
1354
1355 static inline int ebt_make_matchname(const struct ebt_entry_match *m,
1356 const char *base, char __user *ubase)
1357 {
1358 char __user *hlp = ubase + ((char *)m - base);
1359 char name[EBT_FUNCTION_MAXNAMELEN] = {};
1360
1361 /* ebtables expects 32 bytes long names but xt_match names are 29 bytes
1362 * long. Copy 29 bytes and fill remaining bytes with zeroes.
1363 */
1364 strlcpy(name, m->u.match->name, sizeof(name));
1365 if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN))
1366 return -EFAULT;
1367 return 0;
1368 }
1369
1370 static inline int ebt_make_watchername(const struct ebt_entry_watcher *w,
1371 const char *base, char __user *ubase)
1372 {
1373 char __user *hlp = ubase + ((char *)w - base);
1374 char name[EBT_FUNCTION_MAXNAMELEN] = {};
1375
1376 strlcpy(name, w->u.watcher->name, sizeof(name));
1377 if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN))
1378 return -EFAULT;
1379 return 0;
1380 }
1381
1382 static inline int ebt_make_names(struct ebt_entry *e, const char *base,
1383 char __user *ubase)
1384 {
1385 int ret;
1386 char __user *hlp;
1387 const struct ebt_entry_target *t;
1388 char name[EBT_FUNCTION_MAXNAMELEN] = {};
1389
1390 if (e->bitmask == 0)
1391 return 0;
1392
1393 hlp = ubase + (((char *)e + e->target_offset) - base);
1394 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
1395
1396 ret = EBT_MATCH_ITERATE(e, ebt_make_matchname, base, ubase);
1397 if (ret != 0)
1398 return ret;
1399 ret = EBT_WATCHER_ITERATE(e, ebt_make_watchername, base, ubase);
1400 if (ret != 0)
1401 return ret;
1402 strlcpy(name, t->u.target->name, sizeof(name));
1403 if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN))
1404 return -EFAULT;
1405 return 0;
1406 }
1407
1408 static int copy_counters_to_user(struct ebt_table *t,
1409 const struct ebt_counter *oldcounters,
1410 void __user *user, unsigned int num_counters,
1411 unsigned int nentries)
1412 {
1413 struct ebt_counter *counterstmp;
1414 int ret = 0;
1415
1416 /* userspace might not need the counters */
1417 if (num_counters == 0)
1418 return 0;
1419
1420 if (num_counters != nentries) {
1421 BUGPRINT("Num_counters wrong\n");
1422 return -EINVAL;
1423 }
1424
1425 counterstmp = vmalloc(nentries * sizeof(*counterstmp));
1426 if (!counterstmp)
1427 return -ENOMEM;
1428
1429 write_lock_bh(&t->lock);
1430 get_counters(oldcounters, counterstmp, nentries);
1431 write_unlock_bh(&t->lock);
1432
1433 if (copy_to_user(user, counterstmp,
1434 nentries * sizeof(struct ebt_counter)))
1435 ret = -EFAULT;
1436 vfree(counterstmp);
1437 return ret;
1438 }
1439
1440 /* called with ebt_mutex locked */
1441 static int copy_everything_to_user(struct ebt_table *t, void __user *user,
1442 const int *len, int cmd)
1443 {
1444 struct ebt_replace tmp;
1445 const struct ebt_counter *oldcounters;
1446 unsigned int entries_size, nentries;
1447 int ret;
1448 char *entries;
1449
1450 if (cmd == EBT_SO_GET_ENTRIES) {
1451 entries_size = t->private->entries_size;
1452 nentries = t->private->nentries;
1453 entries = t->private->entries;
1454 oldcounters = t->private->counters;
1455 } else {
1456 entries_size = t->table->entries_size;
1457 nentries = t->table->nentries;
1458 entries = t->table->entries;
1459 oldcounters = t->table->counters;
1460 }
1461
1462 if (copy_from_user(&tmp, user, sizeof(tmp)))
1463 return -EFAULT;
1464
1465 if (*len != sizeof(struct ebt_replace) + entries_size +
1466 (tmp.num_counters ? nentries * sizeof(struct ebt_counter) : 0))
1467 return -EINVAL;
1468
1469 if (tmp.nentries != nentries) {
1470 BUGPRINT("Nentries wrong\n");
1471 return -EINVAL;
1472 }
1473
1474 if (tmp.entries_size != entries_size) {
1475 BUGPRINT("Wrong size\n");
1476 return -EINVAL;
1477 }
1478
1479 ret = copy_counters_to_user(t, oldcounters, tmp.counters,
1480 tmp.num_counters, nentries);
1481 if (ret)
1482 return ret;
1483
1484 if (copy_to_user(tmp.entries, entries, entries_size)) {
1485 BUGPRINT("Couldn't copy entries to userspace\n");
1486 return -EFAULT;
1487 }
1488 /* set the match/watcher/target names right */
1489 return EBT_ENTRY_ITERATE(entries, entries_size,
1490 ebt_make_names, entries, tmp.entries);
1491 }
1492
1493 static int do_ebt_set_ctl(struct sock *sk,
1494 int cmd, void __user *user, unsigned int len)
1495 {
1496 int ret;
1497 struct net *net = sock_net(sk);
1498
1499 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1500 return -EPERM;
1501
1502 switch (cmd) {
1503 case EBT_SO_SET_ENTRIES:
1504 ret = do_replace(net, user, len);
1505 break;
1506 case EBT_SO_SET_COUNTERS:
1507 ret = update_counters(net, user, len);
1508 break;
1509 default:
1510 ret = -EINVAL;
1511 }
1512 return ret;
1513 }
1514
1515 static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1516 {
1517 int ret;
1518 struct ebt_replace tmp;
1519 struct ebt_table *t;
1520 struct net *net = sock_net(sk);
1521
1522 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1523 return -EPERM;
1524
1525 if (copy_from_user(&tmp, user, sizeof(tmp)))
1526 return -EFAULT;
1527
1528 tmp.name[sizeof(tmp.name) - 1] = '\0';
1529
1530 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
1531 if (!t)
1532 return ret;
1533
1534 switch (cmd) {
1535 case EBT_SO_GET_INFO:
1536 case EBT_SO_GET_INIT_INFO:
1537 if (*len != sizeof(struct ebt_replace)) {
1538 ret = -EINVAL;
1539 mutex_unlock(&ebt_mutex);
1540 break;
1541 }
1542 if (cmd == EBT_SO_GET_INFO) {
1543 tmp.nentries = t->private->nentries;
1544 tmp.entries_size = t->private->entries_size;
1545 tmp.valid_hooks = t->valid_hooks;
1546 } else {
1547 tmp.nentries = t->table->nentries;
1548 tmp.entries_size = t->table->entries_size;
1549 tmp.valid_hooks = t->table->valid_hooks;
1550 }
1551 mutex_unlock(&ebt_mutex);
1552 if (copy_to_user(user, &tmp, *len) != 0) {
1553 BUGPRINT("c2u Didn't work\n");
1554 ret = -EFAULT;
1555 break;
1556 }
1557 ret = 0;
1558 break;
1559
1560 case EBT_SO_GET_ENTRIES:
1561 case EBT_SO_GET_INIT_ENTRIES:
1562 ret = copy_everything_to_user(t, user, len, cmd);
1563 mutex_unlock(&ebt_mutex);
1564 break;
1565
1566 default:
1567 mutex_unlock(&ebt_mutex);
1568 ret = -EINVAL;
1569 }
1570
1571 return ret;
1572 }
1573
1574 #ifdef CONFIG_COMPAT
1575 /* 32 bit-userspace compatibility definitions. */
1576 struct compat_ebt_replace {
1577 char name[EBT_TABLE_MAXNAMELEN];
1578 compat_uint_t valid_hooks;
1579 compat_uint_t nentries;
1580 compat_uint_t entries_size;
1581 /* start of the chains */
1582 compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
1583 /* nr of counters userspace expects back */
1584 compat_uint_t num_counters;
1585 /* where the kernel will put the old counters. */
1586 compat_uptr_t counters;
1587 compat_uptr_t entries;
1588 };
1589
1590 /* struct ebt_entry_match, _target and _watcher have same layout */
1591 struct compat_ebt_entry_mwt {
1592 union {
1593 char name[EBT_FUNCTION_MAXNAMELEN];
1594 compat_uptr_t ptr;
1595 } u;
1596 compat_uint_t match_size;
1597 compat_uint_t data[0];
1598 };
1599
1600 /* account for possible padding between match_size and ->data */
1601 static int ebt_compat_entry_padsize(void)
1602 {
1603 BUILD_BUG_ON(XT_ALIGN(sizeof(struct ebt_entry_match)) <
1604 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt)));
1605 return (int) XT_ALIGN(sizeof(struct ebt_entry_match)) -
1606 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt));
1607 }
1608
1609 static int ebt_compat_match_offset(const struct xt_match *match,
1610 unsigned int userlen)
1611 {
1612 /* ebt_among needs special handling. The kernel .matchsize is
1613 * set to -1 at registration time; at runtime an EBT_ALIGN()ed
1614 * value is expected.
1615 * Example: userspace sends 4500, ebt_among.c wants 4504.
1616 */
1617 if (unlikely(match->matchsize == -1))
1618 return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
1619 return xt_compat_match_offset(match);
1620 }
1621
1622 static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
1623 unsigned int *size)
1624 {
1625 const struct xt_match *match = m->u.match;
1626 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1627 int off = ebt_compat_match_offset(match, m->match_size);
1628 compat_uint_t msize = m->match_size - off;
1629
1630 BUG_ON(off >= m->match_size);
1631
1632 if (copy_to_user(cm->u.name, match->name,
1633 strlen(match->name) + 1) || put_user(msize, &cm->match_size))
1634 return -EFAULT;
1635
1636 if (match->compat_to_user) {
1637 if (match->compat_to_user(cm->data, m->data))
1638 return -EFAULT;
1639 } else if (copy_to_user(cm->data, m->data, msize))
1640 return -EFAULT;
1641
1642 *size -= ebt_compat_entry_padsize() + off;
1643 *dstptr = cm->data;
1644 *dstptr += msize;
1645 return 0;
1646 }
1647
1648 static int compat_target_to_user(struct ebt_entry_target *t,
1649 void __user **dstptr,
1650 unsigned int *size)
1651 {
1652 const struct xt_target *target = t->u.target;
1653 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1654 int off = xt_compat_target_offset(target);
1655 compat_uint_t tsize = t->target_size - off;
1656
1657 BUG_ON(off >= t->target_size);
1658
1659 if (copy_to_user(cm->u.name, target->name,
1660 strlen(target->name) + 1) || put_user(tsize, &cm->match_size))
1661 return -EFAULT;
1662
1663 if (target->compat_to_user) {
1664 if (target->compat_to_user(cm->data, t->data))
1665 return -EFAULT;
1666 } else if (copy_to_user(cm->data, t->data, tsize))
1667 return -EFAULT;
1668
1669 *size -= ebt_compat_entry_padsize() + off;
1670 *dstptr = cm->data;
1671 *dstptr += tsize;
1672 return 0;
1673 }
1674
1675 static int compat_watcher_to_user(struct ebt_entry_watcher *w,
1676 void __user **dstptr,
1677 unsigned int *size)
1678 {
1679 return compat_target_to_user((struct ebt_entry_target *)w,
1680 dstptr, size);
1681 }
1682
1683 static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
1684 unsigned int *size)
1685 {
1686 struct ebt_entry_target *t;
1687 struct ebt_entry __user *ce;
1688 u32 watchers_offset, target_offset, next_offset;
1689 compat_uint_t origsize;
1690 int ret;
1691
1692 if (e->bitmask == 0) {
1693 if (*size < sizeof(struct ebt_entries))
1694 return -EINVAL;
1695 if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries)))
1696 return -EFAULT;
1697
1698 *dstptr += sizeof(struct ebt_entries);
1699 *size -= sizeof(struct ebt_entries);
1700 return 0;
1701 }
1702
1703 if (*size < sizeof(*ce))
1704 return -EINVAL;
1705
1706 ce = (struct ebt_entry __user *)*dstptr;
1707 if (copy_to_user(ce, e, sizeof(*ce)))
1708 return -EFAULT;
1709
1710 origsize = *size;
1711 *dstptr += sizeof(*ce);
1712
1713 ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
1714 if (ret)
1715 return ret;
1716 watchers_offset = e->watchers_offset - (origsize - *size);
1717
1718 ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
1719 if (ret)
1720 return ret;
1721 target_offset = e->target_offset - (origsize - *size);
1722
1723 t = (struct ebt_entry_target *) ((char *) e + e->target_offset);
1724
1725 ret = compat_target_to_user(t, dstptr, size);
1726 if (ret)
1727 return ret;
1728 next_offset = e->next_offset - (origsize - *size);
1729
1730 if (put_user(watchers_offset, &ce->watchers_offset) ||
1731 put_user(target_offset, &ce->target_offset) ||
1732 put_user(next_offset, &ce->next_offset))
1733 return -EFAULT;
1734
1735 *size -= sizeof(*ce);
1736 return 0;
1737 }
1738
1739 static int compat_calc_match(struct ebt_entry_match *m, int *off)
1740 {
1741 *off += ebt_compat_match_offset(m->u.match, m->match_size);
1742 *off += ebt_compat_entry_padsize();
1743 return 0;
1744 }
1745
1746 static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
1747 {
1748 *off += xt_compat_target_offset(w->u.watcher);
1749 *off += ebt_compat_entry_padsize();
1750 return 0;
1751 }
1752
1753 static int compat_calc_entry(const struct ebt_entry *e,
1754 const struct ebt_table_info *info,
1755 const void *base,
1756 struct compat_ebt_replace *newinfo)
1757 {
1758 const struct ebt_entry_target *t;
1759 unsigned int entry_offset;
1760 int off, ret, i;
1761
1762 if (e->bitmask == 0)
1763 return 0;
1764
1765 off = 0;
1766 entry_offset = (void *)e - base;
1767
1768 EBT_MATCH_ITERATE(e, compat_calc_match, &off);
1769 EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
1770
1771 t = (const struct ebt_entry_target *) ((char *) e + e->target_offset);
1772
1773 off += xt_compat_target_offset(t->u.target);
1774 off += ebt_compat_entry_padsize();
1775
1776 newinfo->entries_size -= off;
1777
1778 ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off);
1779 if (ret)
1780 return ret;
1781
1782 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1783 const void *hookptr = info->hook_entry[i];
1784 if (info->hook_entry[i] &&
1785 (e < (struct ebt_entry *)(base - hookptr))) {
1786 newinfo->hook_entry[i] -= off;
1787 pr_debug("0x%08X -> 0x%08X\n",
1788 newinfo->hook_entry[i] + off,
1789 newinfo->hook_entry[i]);
1790 }
1791 }
1792
1793 return 0;
1794 }
1795
1796
1797 static int compat_table_info(const struct ebt_table_info *info,
1798 struct compat_ebt_replace *newinfo)
1799 {
1800 unsigned int size = info->entries_size;
1801 const void *entries = info->entries;
1802
1803 newinfo->entries_size = size;
1804
1805 xt_compat_init_offsets(NFPROTO_BRIDGE, info->nentries);
1806 return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
1807 entries, newinfo);
1808 }
1809
1810 static int compat_copy_everything_to_user(struct ebt_table *t,
1811 void __user *user, int *len, int cmd)
1812 {
1813 struct compat_ebt_replace repl, tmp;
1814 struct ebt_counter *oldcounters;
1815 struct ebt_table_info tinfo;
1816 int ret;
1817 void __user *pos;
1818
1819 memset(&tinfo, 0, sizeof(tinfo));
1820
1821 if (cmd == EBT_SO_GET_ENTRIES) {
1822 tinfo.entries_size = t->private->entries_size;
1823 tinfo.nentries = t->private->nentries;
1824 tinfo.entries = t->private->entries;
1825 oldcounters = t->private->counters;
1826 } else {
1827 tinfo.entries_size = t->table->entries_size;
1828 tinfo.nentries = t->table->nentries;
1829 tinfo.entries = t->table->entries;
1830 oldcounters = t->table->counters;
1831 }
1832
1833 if (copy_from_user(&tmp, user, sizeof(tmp)))
1834 return -EFAULT;
1835
1836 if (tmp.nentries != tinfo.nentries ||
1837 (tmp.num_counters && tmp.num_counters != tinfo.nentries))
1838 return -EINVAL;
1839
1840 memcpy(&repl, &tmp, sizeof(repl));
1841 if (cmd == EBT_SO_GET_ENTRIES)
1842 ret = compat_table_info(t->private, &repl);
1843 else
1844 ret = compat_table_info(&tinfo, &repl);
1845 if (ret)
1846 return ret;
1847
1848 if (*len != sizeof(tmp) + repl.entries_size +
1849 (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
1850 pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
1851 *len, tinfo.entries_size, repl.entries_size);
1852 return -EINVAL;
1853 }
1854
1855 /* userspace might not need the counters */
1856 ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters),
1857 tmp.num_counters, tinfo.nentries);
1858 if (ret)
1859 return ret;
1860
1861 pos = compat_ptr(tmp.entries);
1862 return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
1863 compat_copy_entry_to_user, &pos, &tmp.entries_size);
1864 }
1865
1866 struct ebt_entries_buf_state {
1867 char *buf_kern_start; /* kernel buffer to copy (translated) data to */
1868 u32 buf_kern_len; /* total size of kernel buffer */
1869 u32 buf_kern_offset; /* amount of data copied so far */
1870 u32 buf_user_offset; /* read position in userspace buffer */
1871 };
1872
1873 static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
1874 {
1875 state->buf_kern_offset += sz;
1876 return state->buf_kern_offset >= sz ? 0 : -EINVAL;
1877 }
1878
1879 static int ebt_buf_add(struct ebt_entries_buf_state *state,
1880 void *data, unsigned int sz)
1881 {
1882 if (state->buf_kern_start == NULL)
1883 goto count_only;
1884
1885 BUG_ON(state->buf_kern_offset + sz > state->buf_kern_len);
1886
1887 memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz);
1888
1889 count_only:
1890 state->buf_user_offset += sz;
1891 return ebt_buf_count(state, sz);
1892 }
1893
1894 static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz)
1895 {
1896 char *b = state->buf_kern_start;
1897
1898 BUG_ON(b && state->buf_kern_offset > state->buf_kern_len);
1899
1900 if (b != NULL && sz > 0)
1901 memset(b + state->buf_kern_offset, 0, sz);
1902 /* do not adjust ->buf_user_offset here, we added kernel-side padding */
1903 return ebt_buf_count(state, sz);
1904 }
1905
1906 enum compat_mwt {
1907 EBT_COMPAT_MATCH,
1908 EBT_COMPAT_WATCHER,
1909 EBT_COMPAT_TARGET,
1910 };
1911
1912 static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt,
1913 enum compat_mwt compat_mwt,
1914 struct ebt_entries_buf_state *state,
1915 const unsigned char *base)
1916 {
1917 char name[EBT_FUNCTION_MAXNAMELEN];
1918 struct xt_match *match;
1919 struct xt_target *wt;
1920 void *dst = NULL;
1921 int off, pad = 0;
1922 unsigned int size_kern, match_size = mwt->match_size;
1923
1924 strlcpy(name, mwt->u.name, sizeof(name));
1925
1926 if (state->buf_kern_start)
1927 dst = state->buf_kern_start + state->buf_kern_offset;
1928
1929 switch (compat_mwt) {
1930 case EBT_COMPAT_MATCH:
1931 match = xt_request_find_match(NFPROTO_BRIDGE, name, 0);
1932 if (IS_ERR(match))
1933 return PTR_ERR(match);
1934
1935 off = ebt_compat_match_offset(match, match_size);
1936 if (dst) {
1937 if (match->compat_from_user)
1938 match->compat_from_user(dst, mwt->data);
1939 else
1940 memcpy(dst, mwt->data, match_size);
1941 }
1942
1943 size_kern = match->matchsize;
1944 if (unlikely(size_kern == -1))
1945 size_kern = match_size;
1946 module_put(match->me);
1947 break;
1948 case EBT_COMPAT_WATCHER: /* fallthrough */
1949 case EBT_COMPAT_TARGET:
1950 wt = xt_request_find_target(NFPROTO_BRIDGE, name, 0);
1951 if (IS_ERR(wt))
1952 return PTR_ERR(wt);
1953 off = xt_compat_target_offset(wt);
1954
1955 if (dst) {
1956 if (wt->compat_from_user)
1957 wt->compat_from_user(dst, mwt->data);
1958 else
1959 memcpy(dst, mwt->data, match_size);
1960 }
1961
1962 size_kern = wt->targetsize;
1963 module_put(wt->me);
1964 break;
1965
1966 default:
1967 return -EINVAL;
1968 }
1969
1970 state->buf_kern_offset += match_size + off;
1971 state->buf_user_offset += match_size;
1972 pad = XT_ALIGN(size_kern) - size_kern;
1973
1974 if (pad > 0 && dst) {
1975 BUG_ON(state->buf_kern_len <= pad);
1976 BUG_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad);
1977 memset(dst + size_kern, 0, pad);
1978 }
1979 return off + match_size;
1980 }
1981
1982 /* return size of all matches, watchers or target, including necessary
1983 * alignment and padding.
1984 */
1985 static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32,
1986 unsigned int size_left, enum compat_mwt type,
1987 struct ebt_entries_buf_state *state, const void *base)
1988 {
1989 int growth = 0;
1990 char *buf;
1991
1992 if (size_left == 0)
1993 return 0;
1994
1995 buf = (char *) match32;
1996
1997 while (size_left >= sizeof(*match32)) {
1998 struct ebt_entry_match *match_kern;
1999 int ret;
2000
2001 match_kern = (struct ebt_entry_match *) state->buf_kern_start;
2002 if (match_kern) {
2003 char *tmp;
2004 tmp = state->buf_kern_start + state->buf_kern_offset;
2005 match_kern = (struct ebt_entry_match *) tmp;
2006 }
2007 ret = ebt_buf_add(state, buf, sizeof(*match32));
2008 if (ret < 0)
2009 return ret;
2010 size_left -= sizeof(*match32);
2011
2012 /* add padding before match->data (if any) */
2013 ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize());
2014 if (ret < 0)
2015 return ret;
2016
2017 if (match32->match_size > size_left)
2018 return -EINVAL;
2019
2020 size_left -= match32->match_size;
2021
2022 ret = compat_mtw_from_user(match32, type, state, base);
2023 if (ret < 0)
2024 return ret;
2025
2026 BUG_ON(ret < match32->match_size);
2027 growth += ret - match32->match_size;
2028 growth += ebt_compat_entry_padsize();
2029
2030 buf += sizeof(*match32);
2031 buf += match32->match_size;
2032
2033 if (match_kern)
2034 match_kern->match_size = ret;
2035
2036 WARN_ON(type == EBT_COMPAT_TARGET && size_left);
2037 match32 = (struct compat_ebt_entry_mwt *) buf;
2038 }
2039
2040 return growth;
2041 }
2042
2043 /* called for all ebt_entry structures. */
2044 static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,
2045 unsigned int *total,
2046 struct ebt_entries_buf_state *state)
2047 {
2048 unsigned int i, j, startoff, new_offset = 0;
2049 /* stores match/watchers/targets & offset of next struct ebt_entry: */
2050 unsigned int offsets[4];
2051 unsigned int *offsets_update = NULL;
2052 int ret;
2053 char *buf_start;
2054
2055 if (*total < sizeof(struct ebt_entries))
2056 return -EINVAL;
2057
2058 if (!entry->bitmask) {
2059 *total -= sizeof(struct ebt_entries);
2060 return ebt_buf_add(state, entry, sizeof(struct ebt_entries));
2061 }
2062 if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
2063 return -EINVAL;
2064
2065 startoff = state->buf_user_offset;
2066 /* pull in most part of ebt_entry, it does not need to be changed. */
2067 ret = ebt_buf_add(state, entry,
2068 offsetof(struct ebt_entry, watchers_offset));
2069 if (ret < 0)
2070 return ret;
2071
2072 offsets[0] = sizeof(struct ebt_entry); /* matches come first */
2073 memcpy(&offsets[1], &entry->watchers_offset,
2074 sizeof(offsets) - sizeof(offsets[0]));
2075
2076 if (state->buf_kern_start) {
2077 buf_start = state->buf_kern_start + state->buf_kern_offset;
2078 offsets_update = (unsigned int *) buf_start;
2079 }
2080 ret = ebt_buf_add(state, &offsets[1],
2081 sizeof(offsets) - sizeof(offsets[0]));
2082 if (ret < 0)
2083 return ret;
2084 buf_start = (char *) entry;
2085 /* 0: matches offset, always follows ebt_entry.
2086 * 1: watchers offset, from ebt_entry structure
2087 * 2: target offset, from ebt_entry structure
2088 * 3: next ebt_entry offset, from ebt_entry structure
2089 *
2090 * offsets are relative to beginning of struct ebt_entry (i.e., 0).
2091 */
2092 for (i = 0, j = 1 ; j < 4 ; j++, i++) {
2093 struct compat_ebt_entry_mwt *match32;
2094 unsigned int size;
2095 char *buf = buf_start;
2096
2097 buf = buf_start + offsets[i];
2098 if (offsets[i] > offsets[j])
2099 return -EINVAL;
2100
2101 match32 = (struct compat_ebt_entry_mwt *) buf;
2102 size = offsets[j] - offsets[i];
2103 ret = ebt_size_mwt(match32, size, i, state, base);
2104 if (ret < 0)
2105 return ret;
2106 new_offset += ret;
2107 if (offsets_update && new_offset) {
2108 pr_debug("change offset %d to %d\n",
2109 offsets_update[i], offsets[j] + new_offset);
2110 offsets_update[i] = offsets[j] + new_offset;
2111 }
2112 }
2113
2114 if (state->buf_kern_start == NULL) {
2115 unsigned int offset = buf_start - (char *) base;
2116
2117 ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);
2118 if (ret < 0)
2119 return ret;
2120 }
2121
2122 startoff = state->buf_user_offset - startoff;
2123
2124 BUG_ON(*total < startoff);
2125 *total -= startoff;
2126 return 0;
2127 }
2128
2129 /* repl->entries_size is the size of the ebt_entry blob in userspace.
2130 * It might need more memory when copied to a 64 bit kernel in case
2131 * userspace is 32-bit. So, first task: find out how much memory is needed.
2132 *
2133 * Called before validation is performed.
2134 */
2135 static int compat_copy_entries(unsigned char *data, unsigned int size_user,
2136 struct ebt_entries_buf_state *state)
2137 {
2138 unsigned int size_remaining = size_user;
2139 int ret;
2140
2141 ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
2142 &size_remaining, state);
2143 if (ret < 0)
2144 return ret;
2145
2146 WARN_ON(size_remaining);
2147 return state->buf_kern_offset;
2148 }
2149
2150
2151 static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
2152 void __user *user, unsigned int len)
2153 {
2154 struct compat_ebt_replace tmp;
2155 int i;
2156
2157 if (len < sizeof(tmp))
2158 return -EINVAL;
2159
2160 if (copy_from_user(&tmp, user, sizeof(tmp)))
2161 return -EFAULT;
2162
2163 if (len != sizeof(tmp) + tmp.entries_size)
2164 return -EINVAL;
2165
2166 if (tmp.entries_size == 0)
2167 return -EINVAL;
2168
2169 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
2170 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
2171 return -ENOMEM;
2172 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
2173 return -ENOMEM;
2174
2175 memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
2176
2177 /* starting with hook_entry, 32 vs. 64 bit structures are different */
2178 for (i = 0; i < NF_BR_NUMHOOKS; i++)
2179 repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]);
2180
2181 repl->num_counters = tmp.num_counters;
2182 repl->counters = compat_ptr(tmp.counters);
2183 repl->entries = compat_ptr(tmp.entries);
2184 return 0;
2185 }
2186
2187 static int compat_do_replace(struct net *net, void __user *user,
2188 unsigned int len)
2189 {
2190 int ret, i, countersize, size64;
2191 struct ebt_table_info *newinfo;
2192 struct ebt_replace tmp;
2193 struct ebt_entries_buf_state state;
2194 void *entries_tmp;
2195
2196 ret = compat_copy_ebt_replace_from_user(&tmp, user, len);
2197 if (ret) {
2198 /* try real handler in case userland supplied needed padding */
2199 if (ret == -EINVAL && do_replace(net, user, len) == 0)
2200 ret = 0;
2201 return ret;
2202 }
2203
2204 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
2205 newinfo = vmalloc(sizeof(*newinfo) + countersize);
2206 if (!newinfo)
2207 return -ENOMEM;
2208
2209 if (countersize)
2210 memset(newinfo->counters, 0, countersize);
2211
2212 memset(&state, 0, sizeof(state));
2213
2214 newinfo->entries = vmalloc(tmp.entries_size);
2215 if (!newinfo->entries) {
2216 ret = -ENOMEM;
2217 goto free_newinfo;
2218 }
2219 if (copy_from_user(
2220 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
2221 ret = -EFAULT;
2222 goto free_entries;
2223 }
2224
2225 entries_tmp = newinfo->entries;
2226
2227 xt_compat_lock(NFPROTO_BRIDGE);
2228
2229 xt_compat_init_offsets(NFPROTO_BRIDGE, tmp.nentries);
2230 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2231 if (ret < 0)
2232 goto out_unlock;
2233
2234 pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
2235 tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
2236 xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
2237
2238 size64 = ret;
2239 newinfo->entries = vmalloc(size64);
2240 if (!newinfo->entries) {
2241 vfree(entries_tmp);
2242 ret = -ENOMEM;
2243 goto out_unlock;
2244 }
2245
2246 memset(&state, 0, sizeof(state));
2247 state.buf_kern_start = newinfo->entries;
2248 state.buf_kern_len = size64;
2249
2250 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2251 BUG_ON(ret < 0); /* parses same data again */
2252
2253 vfree(entries_tmp);
2254 tmp.entries_size = size64;
2255
2256 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
2257 char __user *usrptr;
2258 if (tmp.hook_entry[i]) {
2259 unsigned int delta;
2260 usrptr = (char __user *) tmp.hook_entry[i];
2261 delta = usrptr - tmp.entries;
2262 usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta);
2263 tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
2264 }
2265 }
2266
2267 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2268 xt_compat_unlock(NFPROTO_BRIDGE);
2269
2270 ret = do_replace_finish(net, &tmp, newinfo);
2271 if (ret == 0)
2272 return ret;
2273 free_entries:
2274 vfree(newinfo->entries);
2275 free_newinfo:
2276 vfree(newinfo);
2277 return ret;
2278 out_unlock:
2279 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2280 xt_compat_unlock(NFPROTO_BRIDGE);
2281 goto free_entries;
2282 }
2283
2284 static int compat_update_counters(struct net *net, void __user *user,
2285 unsigned int len)
2286 {
2287 struct compat_ebt_replace hlp;
2288
2289 if (copy_from_user(&hlp, user, sizeof(hlp)))
2290 return -EFAULT;
2291
2292 /* try real handler in case userland supplied needed padding */
2293 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
2294 return update_counters(net, user, len);
2295
2296 return do_update_counters(net, hlp.name, compat_ptr(hlp.counters),
2297 hlp.num_counters, user, len);
2298 }
2299
2300 static int compat_do_ebt_set_ctl(struct sock *sk,
2301 int cmd, void __user *user, unsigned int len)
2302 {
2303 int ret;
2304 struct net *net = sock_net(sk);
2305
2306 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2307 return -EPERM;
2308
2309 switch (cmd) {
2310 case EBT_SO_SET_ENTRIES:
2311 ret = compat_do_replace(net, user, len);
2312 break;
2313 case EBT_SO_SET_COUNTERS:
2314 ret = compat_update_counters(net, user, len);
2315 break;
2316 default:
2317 ret = -EINVAL;
2318 }
2319 return ret;
2320 }
2321
2322 static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
2323 void __user *user, int *len)
2324 {
2325 int ret;
2326 struct compat_ebt_replace tmp;
2327 struct ebt_table *t;
2328 struct net *net = sock_net(sk);
2329
2330 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2331 return -EPERM;
2332
2333 /* try real handler in case userland supplied needed padding */
2334 if ((cmd == EBT_SO_GET_INFO ||
2335 cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp))
2336 return do_ebt_get_ctl(sk, cmd, user, len);
2337
2338 if (copy_from_user(&tmp, user, sizeof(tmp)))
2339 return -EFAULT;
2340
2341 tmp.name[sizeof(tmp.name) - 1] = '\0';
2342
2343 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
2344 if (!t)
2345 return ret;
2346
2347 xt_compat_lock(NFPROTO_BRIDGE);
2348 switch (cmd) {
2349 case EBT_SO_GET_INFO:
2350 tmp.nentries = t->private->nentries;
2351 ret = compat_table_info(t->private, &tmp);
2352 if (ret)
2353 goto out;
2354 tmp.valid_hooks = t->valid_hooks;
2355
2356 if (copy_to_user(user, &tmp, *len) != 0) {
2357 ret = -EFAULT;
2358 break;
2359 }
2360 ret = 0;
2361 break;
2362 case EBT_SO_GET_INIT_INFO:
2363 tmp.nentries = t->table->nentries;
2364 tmp.entries_size = t->table->entries_size;
2365 tmp.valid_hooks = t->table->valid_hooks;
2366
2367 if (copy_to_user(user, &tmp, *len) != 0) {
2368 ret = -EFAULT;
2369 break;
2370 }
2371 ret = 0;
2372 break;
2373 case EBT_SO_GET_ENTRIES:
2374 case EBT_SO_GET_INIT_ENTRIES:
2375 /* try real handler first in case of userland-side padding.
2376 * in case we are dealing with an 'ordinary' 32 bit binary
2377 * without 64bit compatibility padding, this will fail right
2378 * after copy_from_user when the *len argument is validated.
2379 *
2380 * the compat_ variant needs to do one pass over the kernel
2381 * data set to adjust for size differences before it the check.
2382 */
2383 if (copy_everything_to_user(t, user, len, cmd) == 0)
2384 ret = 0;
2385 else
2386 ret = compat_copy_everything_to_user(t, user, len, cmd);
2387 break;
2388 default:
2389 ret = -EINVAL;
2390 }
2391 out:
2392 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2393 xt_compat_unlock(NFPROTO_BRIDGE);
2394 mutex_unlock(&ebt_mutex);
2395 return ret;
2396 }
2397 #endif
2398
2399 static struct nf_sockopt_ops ebt_sockopts = {
2400 .pf = PF_INET,
2401 .set_optmin = EBT_BASE_CTL,
2402 .set_optmax = EBT_SO_SET_MAX + 1,
2403 .set = do_ebt_set_ctl,
2404 #ifdef CONFIG_COMPAT
2405 .compat_set = compat_do_ebt_set_ctl,
2406 #endif
2407 .get_optmin = EBT_BASE_CTL,
2408 .get_optmax = EBT_SO_GET_MAX + 1,
2409 .get = do_ebt_get_ctl,
2410 #ifdef CONFIG_COMPAT
2411 .compat_get = compat_do_ebt_get_ctl,
2412 #endif
2413 .owner = THIS_MODULE,
2414 };
2415
2416 static int __init ebtables_init(void)
2417 {
2418 int ret;
2419
2420 ret = xt_register_target(&ebt_standard_target);
2421 if (ret < 0)
2422 return ret;
2423 ret = nf_register_sockopt(&ebt_sockopts);
2424 if (ret < 0) {
2425 xt_unregister_target(&ebt_standard_target);
2426 return ret;
2427 }
2428
2429 printk(KERN_INFO "Ebtables v2.0 registered\n");
2430 return 0;
2431 }
2432
2433 static void __exit ebtables_fini(void)
2434 {
2435 nf_unregister_sockopt(&ebt_sockopts);
2436 xt_unregister_target(&ebt_standard_target);
2437 printk(KERN_INFO "Ebtables v2.0 unregistered\n");
2438 }
2439
2440 EXPORT_SYMBOL(ebt_register_table);
2441 EXPORT_SYMBOL(ebt_unregister_table);
2442 EXPORT_SYMBOL(ebt_do_table);
2443 module_init(ebtables_init);
2444 module_exit(ebtables_fini);
2445 MODULE_LICENSE("GPL");
Linux with added FPC-III support