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Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-3.6
[deliverable/linux.git] / net / bridge / netfilter / ebtables.c
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 stongly inspired on 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 <net/sock.h>
30 /* needed for logical [in,out]-dev filtering */
31 #include "../br_private.h"
32
33 #define BUGPRINT(format, args...) printk("kernel msg: ebtables bug: please "\
34 "report to author: "format, ## args)
35 /* #define BUGPRINT(format, args...) */
36
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 (vlan_tx_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(ntohs(ethproto) >= 1536, 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 __pure
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 (unsigned int hook, struct sk_buff *skb,
186 const struct net_device *in, const struct net_device *out,
187 struct ebt_table *table)
188 {
189 int i, nentries;
190 struct ebt_entry *point;
191 struct ebt_counter *counter_base, *cb_base;
192 const struct ebt_entry_target *t;
193 int verdict, sp = 0;
194 struct ebt_chainstack *cs;
195 struct ebt_entries *chaininfo;
196 const char *base;
197 const struct ebt_table_info *private;
198 struct xt_action_param acpar;
199
200 acpar.family = NFPROTO_BRIDGE;
201 acpar.in = in;
202 acpar.out = out;
203 acpar.hotdrop = false;
204 acpar.hooknum = hook;
205
206 read_lock_bh(&table->lock);
207 private = table->private;
208 cb_base = COUNTER_BASE(private->counters, private->nentries,
209 smp_processor_id());
210 if (private->chainstack)
211 cs = private->chainstack[smp_processor_id()];
212 else
213 cs = NULL;
214 chaininfo = private->hook_entry[hook];
215 nentries = private->hook_entry[hook]->nentries;
216 point = (struct ebt_entry *)(private->hook_entry[hook]->data);
217 counter_base = cb_base + private->hook_entry[hook]->counter_offset;
218 /* base for chain jumps */
219 base = private->entries;
220 i = 0;
221 while (i < nentries) {
222 if (ebt_basic_match(point, skb, in, out))
223 goto letscontinue;
224
225 if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0)
226 goto letscontinue;
227 if (acpar.hotdrop) {
228 read_unlock_bh(&table->lock);
229 return NF_DROP;
230 }
231
232 /* increase counter */
233 (*(counter_base + i)).pcnt++;
234 (*(counter_base + i)).bcnt += skb->len;
235
236 /* these should only watch: not modify, nor tell us
237 what to do with the packet */
238 EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar);
239
240 t = (struct ebt_entry_target *)
241 (((char *)point) + point->target_offset);
242 /* standard target */
243 if (!t->u.target->target)
244 verdict = ((struct ebt_standard_target *)t)->verdict;
245 else {
246 acpar.target = t->u.target;
247 acpar.targinfo = t->data;
248 verdict = t->u.target->target(skb, &acpar);
249 }
250 if (verdict == EBT_ACCEPT) {
251 read_unlock_bh(&table->lock);
252 return NF_ACCEPT;
253 }
254 if (verdict == EBT_DROP) {
255 read_unlock_bh(&table->lock);
256 return NF_DROP;
257 }
258 if (verdict == EBT_RETURN) {
259 letsreturn:
260 #ifdef CONFIG_NETFILTER_DEBUG
261 if (sp == 0) {
262 BUGPRINT("RETURN on base chain");
263 /* act like this is EBT_CONTINUE */
264 goto letscontinue;
265 }
266 #endif
267 sp--;
268 /* put all the local variables right */
269 i = cs[sp].n;
270 chaininfo = cs[sp].chaininfo;
271 nentries = chaininfo->nentries;
272 point = cs[sp].e;
273 counter_base = cb_base +
274 chaininfo->counter_offset;
275 continue;
276 }
277 if (verdict == EBT_CONTINUE)
278 goto letscontinue;
279 #ifdef CONFIG_NETFILTER_DEBUG
280 if (verdict < 0) {
281 BUGPRINT("bogus standard verdict\n");
282 read_unlock_bh(&table->lock);
283 return NF_DROP;
284 }
285 #endif
286 /* jump to a udc */
287 cs[sp].n = i + 1;
288 cs[sp].chaininfo = chaininfo;
289 cs[sp].e = ebt_next_entry(point);
290 i = 0;
291 chaininfo = (struct ebt_entries *) (base + verdict);
292 #ifdef CONFIG_NETFILTER_DEBUG
293 if (chaininfo->distinguisher) {
294 BUGPRINT("jump to non-chain\n");
295 read_unlock_bh(&table->lock);
296 return NF_DROP;
297 }
298 #endif
299 nentries = chaininfo->nentries;
300 point = (struct ebt_entry *)chaininfo->data;
301 counter_base = cb_base + chaininfo->counter_offset;
302 sp++;
303 continue;
304 letscontinue:
305 point = ebt_next_entry(point);
306 i++;
307 }
308
309 /* I actually like this :) */
310 if (chaininfo->policy == EBT_RETURN)
311 goto letsreturn;
312 if (chaininfo->policy == EBT_ACCEPT) {
313 read_unlock_bh(&table->lock);
314 return NF_ACCEPT;
315 }
316 read_unlock_bh(&table->lock);
317 return NF_DROP;
318 }
319
320 /* If it succeeds, returns element and locks mutex */
321 static inline void *
322 find_inlist_lock_noload(struct list_head *head, const char *name, int *error,
323 struct mutex *mutex)
324 {
325 struct {
326 struct list_head list;
327 char name[EBT_FUNCTION_MAXNAMELEN];
328 } *e;
329
330 *error = mutex_lock_interruptible(mutex);
331 if (*error != 0)
332 return NULL;
333
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_request_find_match(NFPROTO_BRIDGE, m->u.name, 0);
374 if (IS_ERR(match))
375 return PTR_ERR(match);
376 m->u.match = match;
377
378 par->match = match;
379 par->matchinfo = m->data;
380 ret = xt_check_match(par, m->match_size,
381 e->ethproto, e->invflags & EBT_IPROTO);
382 if (ret < 0) {
383 module_put(match->me);
384 return ret;
385 }
386
387 (*cnt)++;
388 return 0;
389 }
390
391 static inline int
392 ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
393 unsigned int *cnt)
394 {
395 const struct ebt_entry *e = par->entryinfo;
396 struct xt_target *watcher;
397 size_t left = ((char *)e + e->target_offset) - (char *)w;
398 int ret;
399
400 if (left < sizeof(struct ebt_entry_watcher) ||
401 left - sizeof(struct ebt_entry_watcher) < w->watcher_size)
402 return -EINVAL;
403
404 watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0);
405 if (IS_ERR(watcher))
406 return PTR_ERR(watcher);
407 w->u.watcher = watcher;
408
409 par->target = watcher;
410 par->targinfo = w->data;
411 ret = xt_check_target(par, w->watcher_size,
412 e->ethproto, e->invflags & EBT_IPROTO);
413 if (ret < 0) {
414 module_put(watcher->me);
415 return ret;
416 }
417
418 (*cnt)++;
419 return 0;
420 }
421
422 static int ebt_verify_pointers(const struct ebt_replace *repl,
423 struct ebt_table_info *newinfo)
424 {
425 unsigned int limit = repl->entries_size;
426 unsigned int valid_hooks = repl->valid_hooks;
427 unsigned int offset = 0;
428 int i;
429
430 for (i = 0; i < NF_BR_NUMHOOKS; i++)
431 newinfo->hook_entry[i] = NULL;
432
433 newinfo->entries_size = repl->entries_size;
434 newinfo->nentries = repl->nentries;
435
436 while (offset < limit) {
437 size_t left = limit - offset;
438 struct ebt_entry *e = (void *)newinfo->entries + offset;
439
440 if (left < sizeof(unsigned int))
441 break;
442
443 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
444 if ((valid_hooks & (1 << i)) == 0)
445 continue;
446 if ((char __user *)repl->hook_entry[i] ==
447 repl->entries + offset)
448 break;
449 }
450
451 if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
452 if (e->bitmask != 0) {
453 /* we make userspace set this right,
454 so there is no misunderstanding */
455 BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set "
456 "in distinguisher\n");
457 return -EINVAL;
458 }
459 if (i != NF_BR_NUMHOOKS)
460 newinfo->hook_entry[i] = (struct ebt_entries *)e;
461 if (left < sizeof(struct ebt_entries))
462 break;
463 offset += sizeof(struct ebt_entries);
464 } else {
465 if (left < sizeof(struct ebt_entry))
466 break;
467 if (left < e->next_offset)
468 break;
469 if (e->next_offset < sizeof(struct ebt_entry))
470 return -EINVAL;
471 offset += e->next_offset;
472 }
473 }
474 if (offset != limit) {
475 BUGPRINT("entries_size too small\n");
476 return -EINVAL;
477 }
478
479 /* check if all valid hooks have a chain */
480 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
481 if (!newinfo->hook_entry[i] &&
482 (valid_hooks & (1 << i))) {
483 BUGPRINT("Valid hook without chain\n");
484 return -EINVAL;
485 }
486 }
487 return 0;
488 }
489
490 /*
491 * this one is very careful, as it is the first function
492 * to parse the userspace data
493 */
494 static inline int
495 ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
496 const struct ebt_table_info *newinfo,
497 unsigned int *n, unsigned int *cnt,
498 unsigned int *totalcnt, unsigned int *udc_cnt)
499 {
500 int i;
501
502 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
503 if ((void *)e == (void *)newinfo->hook_entry[i])
504 break;
505 }
506 /* beginning of a new chain
507 if i == NF_BR_NUMHOOKS it must be a user defined chain */
508 if (i != NF_BR_NUMHOOKS || !e->bitmask) {
509 /* this checks if the previous chain has as many entries
510 as it said it has */
511 if (*n != *cnt) {
512 BUGPRINT("nentries does not equal the nr of entries "
513 "in the chain\n");
514 return -EINVAL;
515 }
516 if (((struct ebt_entries *)e)->policy != EBT_DROP &&
517 ((struct ebt_entries *)e)->policy != EBT_ACCEPT) {
518 /* only RETURN from udc */
519 if (i != NF_BR_NUMHOOKS ||
520 ((struct ebt_entries *)e)->policy != EBT_RETURN) {
521 BUGPRINT("bad policy\n");
522 return -EINVAL;
523 }
524 }
525 if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */
526 (*udc_cnt)++;
527 if (((struct ebt_entries *)e)->counter_offset != *totalcnt) {
528 BUGPRINT("counter_offset != totalcnt");
529 return -EINVAL;
530 }
531 *n = ((struct ebt_entries *)e)->nentries;
532 *cnt = 0;
533 return 0;
534 }
535 /* a plain old entry, heh */
536 if (sizeof(struct ebt_entry) > e->watchers_offset ||
537 e->watchers_offset > e->target_offset ||
538 e->target_offset >= e->next_offset) {
539 BUGPRINT("entry offsets not in right order\n");
540 return -EINVAL;
541 }
542 /* this is not checked anywhere else */
543 if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target)) {
544 BUGPRINT("target size too small\n");
545 return -EINVAL;
546 }
547 (*cnt)++;
548 (*totalcnt)++;
549 return 0;
550 }
551
552 struct ebt_cl_stack
553 {
554 struct ebt_chainstack cs;
555 int from;
556 unsigned int hookmask;
557 };
558
559 /*
560 * we need these positions to check that the jumps to a different part of the
561 * entries is a jump to the beginning of a new chain.
562 */
563 static inline int
564 ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo,
565 unsigned int *n, struct ebt_cl_stack *udc)
566 {
567 int i;
568
569 /* we're only interested in chain starts */
570 if (e->bitmask)
571 return 0;
572 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
573 if (newinfo->hook_entry[i] == (struct ebt_entries *)e)
574 break;
575 }
576 /* only care about udc */
577 if (i != NF_BR_NUMHOOKS)
578 return 0;
579
580 udc[*n].cs.chaininfo = (struct ebt_entries *)e;
581 /* these initialisations are depended on later in check_chainloops() */
582 udc[*n].cs.n = 0;
583 udc[*n].hookmask = 0;
584
585 (*n)++;
586 return 0;
587 }
588
589 static inline int
590 ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i)
591 {
592 struct xt_mtdtor_param par;
593
594 if (i && (*i)-- == 0)
595 return 1;
596
597 par.net = net;
598 par.match = m->u.match;
599 par.matchinfo = m->data;
600 par.family = NFPROTO_BRIDGE;
601 if (par.match->destroy != NULL)
602 par.match->destroy(&par);
603 module_put(par.match->me);
604 return 0;
605 }
606
607 static inline int
608 ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i)
609 {
610 struct xt_tgdtor_param par;
611
612 if (i && (*i)-- == 0)
613 return 1;
614
615 par.net = net;
616 par.target = w->u.watcher;
617 par.targinfo = w->data;
618 par.family = NFPROTO_BRIDGE;
619 if (par.target->destroy != NULL)
620 par.target->destroy(&par);
621 module_put(par.target->me);
622 return 0;
623 }
624
625 static inline int
626 ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
627 {
628 struct xt_tgdtor_param par;
629 struct ebt_entry_target *t;
630
631 if (e->bitmask == 0)
632 return 0;
633 /* we're done */
634 if (cnt && (*cnt)-- == 0)
635 return 1;
636 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL);
637 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL);
638 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
639
640 par.net = net;
641 par.target = t->u.target;
642 par.targinfo = t->data;
643 par.family = NFPROTO_BRIDGE;
644 if (par.target->destroy != NULL)
645 par.target->destroy(&par);
646 module_put(par.target->me);
647 return 0;
648 }
649
650 static inline int
651 ebt_check_entry(struct ebt_entry *e, struct net *net,
652 const struct ebt_table_info *newinfo,
653 const char *name, unsigned int *cnt,
654 struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
655 {
656 struct ebt_entry_target *t;
657 struct xt_target *target;
658 unsigned int i, j, hook = 0, hookmask = 0;
659 size_t gap;
660 int ret;
661 struct xt_mtchk_param mtpar;
662 struct xt_tgchk_param tgpar;
663
664 /* don't mess with the struct ebt_entries */
665 if (e->bitmask == 0)
666 return 0;
667
668 if (e->bitmask & ~EBT_F_MASK) {
669 BUGPRINT("Unknown flag for bitmask\n");
670 return -EINVAL;
671 }
672 if (e->invflags & ~EBT_INV_MASK) {
673 BUGPRINT("Unknown flag for inv bitmask\n");
674 return -EINVAL;
675 }
676 if ( (e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3) ) {
677 BUGPRINT("NOPROTO & 802_3 not allowed\n");
678 return -EINVAL;
679 }
680 /* what hook do we belong to? */
681 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
682 if (!newinfo->hook_entry[i])
683 continue;
684 if ((char *)newinfo->hook_entry[i] < (char *)e)
685 hook = i;
686 else
687 break;
688 }
689 /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on
690 a base chain */
691 if (i < NF_BR_NUMHOOKS)
692 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
693 else {
694 for (i = 0; i < udc_cnt; i++)
695 if ((char *)(cl_s[i].cs.chaininfo) > (char *)e)
696 break;
697 if (i == 0)
698 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
699 else
700 hookmask = cl_s[i - 1].hookmask;
701 }
702 i = 0;
703
704 mtpar.net = tgpar.net = net;
705 mtpar.table = tgpar.table = name;
706 mtpar.entryinfo = tgpar.entryinfo = e;
707 mtpar.hook_mask = tgpar.hook_mask = hookmask;
708 mtpar.family = tgpar.family = NFPROTO_BRIDGE;
709 ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i);
710 if (ret != 0)
711 goto cleanup_matches;
712 j = 0;
713 ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j);
714 if (ret != 0)
715 goto cleanup_watchers;
716 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
717 gap = e->next_offset - e->target_offset;
718
719 target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0);
720 if (IS_ERR(target)) {
721 ret = PTR_ERR(target);
722 goto cleanup_watchers;
723 }
724
725 t->u.target = target;
726 if (t->u.target == &ebt_standard_target) {
727 if (gap < sizeof(struct ebt_standard_target)) {
728 BUGPRINT("Standard target size too big\n");
729 ret = -EFAULT;
730 goto cleanup_watchers;
731 }
732 if (((struct ebt_standard_target *)t)->verdict <
733 -NUM_STANDARD_TARGETS) {
734 BUGPRINT("Invalid standard target\n");
735 ret = -EFAULT;
736 goto cleanup_watchers;
737 }
738 } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) {
739 module_put(t->u.target->me);
740 ret = -EFAULT;
741 goto cleanup_watchers;
742 }
743
744 tgpar.target = target;
745 tgpar.targinfo = t->data;
746 ret = xt_check_target(&tgpar, t->target_size,
747 e->ethproto, e->invflags & EBT_IPROTO);
748 if (ret < 0) {
749 module_put(target->me);
750 goto cleanup_watchers;
751 }
752 (*cnt)++;
753 return 0;
754 cleanup_watchers:
755 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j);
756 cleanup_matches:
757 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i);
758 return ret;
759 }
760
761 /*
762 * checks for loops and sets the hook mask for udc
763 * the hook mask for udc tells us from which base chains the udc can be
764 * accessed. This mask is a parameter to the check() functions of the extensions
765 */
766 static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
767 unsigned int udc_cnt, unsigned int hooknr, char *base)
768 {
769 int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
770 const struct ebt_entry *e = (struct ebt_entry *)chain->data;
771 const struct ebt_entry_target *t;
772
773 while (pos < nentries || chain_nr != -1) {
774 /* end of udc, go back one 'recursion' step */
775 if (pos == nentries) {
776 /* put back values of the time when this chain was called */
777 e = cl_s[chain_nr].cs.e;
778 if (cl_s[chain_nr].from != -1)
779 nentries =
780 cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries;
781 else
782 nentries = chain->nentries;
783 pos = cl_s[chain_nr].cs.n;
784 /* make sure we won't see a loop that isn't one */
785 cl_s[chain_nr].cs.n = 0;
786 chain_nr = cl_s[chain_nr].from;
787 if (pos == nentries)
788 continue;
789 }
790 t = (struct ebt_entry_target *)
791 (((char *)e) + e->target_offset);
792 if (strcmp(t->u.name, EBT_STANDARD_TARGET))
793 goto letscontinue;
794 if (e->target_offset + sizeof(struct ebt_standard_target) >
795 e->next_offset) {
796 BUGPRINT("Standard target size too big\n");
797 return -1;
798 }
799 verdict = ((struct ebt_standard_target *)t)->verdict;
800 if (verdict >= 0) { /* jump to another chain */
801 struct ebt_entries *hlp2 =
802 (struct ebt_entries *)(base + verdict);
803 for (i = 0; i < udc_cnt; i++)
804 if (hlp2 == cl_s[i].cs.chaininfo)
805 break;
806 /* bad destination or loop */
807 if (i == udc_cnt) {
808 BUGPRINT("bad destination\n");
809 return -1;
810 }
811 if (cl_s[i].cs.n) {
812 BUGPRINT("loop\n");
813 return -1;
814 }
815 if (cl_s[i].hookmask & (1 << hooknr))
816 goto letscontinue;
817 /* this can't be 0, so the loop test is correct */
818 cl_s[i].cs.n = pos + 1;
819 pos = 0;
820 cl_s[i].cs.e = ebt_next_entry(e);
821 e = (struct ebt_entry *)(hlp2->data);
822 nentries = hlp2->nentries;
823 cl_s[i].from = chain_nr;
824 chain_nr = i;
825 /* this udc is accessible from the base chain for hooknr */
826 cl_s[i].hookmask |= (1 << hooknr);
827 continue;
828 }
829 letscontinue:
830 e = ebt_next_entry(e);
831 pos++;
832 }
833 return 0;
834 }
835
836 /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
837 static int translate_table(struct net *net, const char *name,
838 struct ebt_table_info *newinfo)
839 {
840 unsigned int i, j, k, udc_cnt;
841 int ret;
842 struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */
843
844 i = 0;
845 while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i])
846 i++;
847 if (i == NF_BR_NUMHOOKS) {
848 BUGPRINT("No valid hooks specified\n");
849 return -EINVAL;
850 }
851 if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) {
852 BUGPRINT("Chains don't start at beginning\n");
853 return -EINVAL;
854 }
855 /* make sure chains are ordered after each other in same order
856 as their corresponding hooks */
857 for (j = i + 1; j < NF_BR_NUMHOOKS; j++) {
858 if (!newinfo->hook_entry[j])
859 continue;
860 if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) {
861 BUGPRINT("Hook order must be followed\n");
862 return -EINVAL;
863 }
864 i = j;
865 }
866
867 /* do some early checkings and initialize some things */
868 i = 0; /* holds the expected nr. of entries for the chain */
869 j = 0; /* holds the up to now counted entries for the chain */
870 k = 0; /* holds the total nr. of entries, should equal
871 newinfo->nentries afterwards */
872 udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */
873 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
874 ebt_check_entry_size_and_hooks, newinfo,
875 &i, &j, &k, &udc_cnt);
876
877 if (ret != 0)
878 return ret;
879
880 if (i != j) {
881 BUGPRINT("nentries does not equal the nr of entries in the "
882 "(last) chain\n");
883 return -EINVAL;
884 }
885 if (k != newinfo->nentries) {
886 BUGPRINT("Total nentries is wrong\n");
887 return -EINVAL;
888 }
889
890 /* get the location of the udc, put them in an array
891 while we're at it, allocate the chainstack */
892 if (udc_cnt) {
893 /* this will get free'd in do_replace()/ebt_register_table()
894 if an error occurs */
895 newinfo->chainstack =
896 vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack)));
897 if (!newinfo->chainstack)
898 return -ENOMEM;
899 for_each_possible_cpu(i) {
900 newinfo->chainstack[i] =
901 vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0])));
902 if (!newinfo->chainstack[i]) {
903 while (i)
904 vfree(newinfo->chainstack[--i]);
905 vfree(newinfo->chainstack);
906 newinfo->chainstack = NULL;
907 return -ENOMEM;
908 }
909 }
910
911 cl_s = vmalloc(udc_cnt * sizeof(*cl_s));
912 if (!cl_s)
913 return -ENOMEM;
914 i = 0; /* the i'th udc */
915 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
916 ebt_get_udc_positions, newinfo, &i, cl_s);
917 /* sanity check */
918 if (i != udc_cnt) {
919 BUGPRINT("i != udc_cnt\n");
920 vfree(cl_s);
921 return -EFAULT;
922 }
923 }
924
925 /* Check for loops */
926 for (i = 0; i < NF_BR_NUMHOOKS; i++)
927 if (newinfo->hook_entry[i])
928 if (check_chainloops(newinfo->hook_entry[i],
929 cl_s, udc_cnt, i, newinfo->entries)) {
930 vfree(cl_s);
931 return -EINVAL;
932 }
933
934 /* we now know the following (along with E=mc²):
935 - the nr of entries in each chain is right
936 - the size of the allocated space is right
937 - all valid hooks have a corresponding chain
938 - there are no loops
939 - wrong data can still be on the level of a single entry
940 - could be there are jumps to places that are not the
941 beginning of a chain. This can only occur in chains that
942 are not accessible from any base chains, so we don't care. */
943
944 /* used to know what we need to clean up if something goes wrong */
945 i = 0;
946 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
947 ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt);
948 if (ret != 0) {
949 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
950 ebt_cleanup_entry, net, &i);
951 }
952 vfree(cl_s);
953 return ret;
954 }
955
956 /* called under write_lock */
957 static void get_counters(const struct ebt_counter *oldcounters,
958 struct ebt_counter *counters, unsigned int nentries)
959 {
960 int i, cpu;
961 struct ebt_counter *counter_base;
962
963 /* counters of cpu 0 */
964 memcpy(counters, oldcounters,
965 sizeof(struct ebt_counter) * nentries);
966
967 /* add other counters to those of cpu 0 */
968 for_each_possible_cpu(cpu) {
969 if (cpu == 0)
970 continue;
971 counter_base = COUNTER_BASE(oldcounters, nentries, cpu);
972 for (i = 0; i < nentries; i++) {
973 counters[i].pcnt += counter_base[i].pcnt;
974 counters[i].bcnt += counter_base[i].bcnt;
975 }
976 }
977 }
978
979 static int do_replace_finish(struct net *net, struct ebt_replace *repl,
980 struct ebt_table_info *newinfo)
981 {
982 int ret, i;
983 struct ebt_counter *counterstmp = NULL;
984 /* used to be able to unlock earlier */
985 struct ebt_table_info *table;
986 struct ebt_table *t;
987
988 /* the user wants counters back
989 the check on the size is done later, when we have the lock */
990 if (repl->num_counters) {
991 unsigned long size = repl->num_counters * sizeof(*counterstmp);
992 counterstmp = vmalloc(size);
993 if (!counterstmp)
994 return -ENOMEM;
995 }
996
997 newinfo->chainstack = NULL;
998 ret = ebt_verify_pointers(repl, newinfo);
999 if (ret != 0)
1000 goto free_counterstmp;
1001
1002 ret = translate_table(net, repl->name, newinfo);
1003
1004 if (ret != 0)
1005 goto free_counterstmp;
1006
1007 t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
1008 if (!t) {
1009 ret = -ENOENT;
1010 goto free_iterate;
1011 }
1012
1013 /* the table doesn't like it */
1014 if (t->check && (ret = t->check(newinfo, repl->valid_hooks)))
1015 goto free_unlock;
1016
1017 if (repl->num_counters && repl->num_counters != t->private->nentries) {
1018 BUGPRINT("Wrong nr. of counters requested\n");
1019 ret = -EINVAL;
1020 goto free_unlock;
1021 }
1022
1023 /* we have the mutex lock, so no danger in reading this pointer */
1024 table = t->private;
1025 /* make sure the table can only be rmmod'ed if it contains no rules */
1026 if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) {
1027 ret = -ENOENT;
1028 goto free_unlock;
1029 } else if (table->nentries && !newinfo->nentries)
1030 module_put(t->me);
1031 /* we need an atomic snapshot of the counters */
1032 write_lock_bh(&t->lock);
1033 if (repl->num_counters)
1034 get_counters(t->private->counters, counterstmp,
1035 t->private->nentries);
1036
1037 t->private = newinfo;
1038 write_unlock_bh(&t->lock);
1039 mutex_unlock(&ebt_mutex);
1040 /* so, a user can change the chains while having messed up her counter
1041 allocation. Only reason why this is done is because this way the lock
1042 is held only once, while this doesn't bring the kernel into a
1043 dangerous state. */
1044 if (repl->num_counters &&
1045 copy_to_user(repl->counters, counterstmp,
1046 repl->num_counters * sizeof(struct ebt_counter))) {
1047 ret = -EFAULT;
1048 }
1049 else
1050 ret = 0;
1051
1052 /* decrease module count and free resources */
1053 EBT_ENTRY_ITERATE(table->entries, table->entries_size,
1054 ebt_cleanup_entry, net, NULL);
1055
1056 vfree(table->entries);
1057 if (table->chainstack) {
1058 for_each_possible_cpu(i)
1059 vfree(table->chainstack[i]);
1060 vfree(table->chainstack);
1061 }
1062 vfree(table);
1063
1064 vfree(counterstmp);
1065 return ret;
1066
1067 free_unlock:
1068 mutex_unlock(&ebt_mutex);
1069 free_iterate:
1070 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
1071 ebt_cleanup_entry, net, NULL);
1072 free_counterstmp:
1073 vfree(counterstmp);
1074 /* can be initialized in translate_table() */
1075 if (newinfo->chainstack) {
1076 for_each_possible_cpu(i)
1077 vfree(newinfo->chainstack[i]);
1078 vfree(newinfo->chainstack);
1079 }
1080 return ret;
1081 }
1082
1083 /* replace the table */
1084 static int do_replace(struct net *net, const void __user *user,
1085 unsigned int len)
1086 {
1087 int ret, countersize;
1088 struct ebt_table_info *newinfo;
1089 struct ebt_replace tmp;
1090
1091 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1092 return -EFAULT;
1093
1094 if (len != sizeof(tmp) + tmp.entries_size) {
1095 BUGPRINT("Wrong len argument\n");
1096 return -EINVAL;
1097 }
1098
1099 if (tmp.entries_size == 0) {
1100 BUGPRINT("Entries_size never zero\n");
1101 return -EINVAL;
1102 }
1103 /* overflow check */
1104 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
1105 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
1106 return -ENOMEM;
1107 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
1108 return -ENOMEM;
1109
1110 tmp.name[sizeof(tmp.name) - 1] = 0;
1111
1112 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
1113 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1114 if (!newinfo)
1115 return -ENOMEM;
1116
1117 if (countersize)
1118 memset(newinfo->counters, 0, countersize);
1119
1120 newinfo->entries = vmalloc(tmp.entries_size);
1121 if (!newinfo->entries) {
1122 ret = -ENOMEM;
1123 goto free_newinfo;
1124 }
1125 if (copy_from_user(
1126 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
1127 BUGPRINT("Couldn't copy entries from userspace\n");
1128 ret = -EFAULT;
1129 goto free_entries;
1130 }
1131
1132 ret = do_replace_finish(net, &tmp, newinfo);
1133 if (ret == 0)
1134 return ret;
1135 free_entries:
1136 vfree(newinfo->entries);
1137 free_newinfo:
1138 vfree(newinfo);
1139 return ret;
1140 }
1141
1142 struct ebt_table *
1143 ebt_register_table(struct net *net, const struct ebt_table *input_table)
1144 {
1145 struct ebt_table_info *newinfo;
1146 struct ebt_table *t, *table;
1147 struct ebt_replace_kernel *repl;
1148 int ret, i, countersize;
1149 void *p;
1150
1151 if (input_table == NULL || (repl = input_table->table) == NULL ||
1152 repl->entries == NULL || repl->entries_size == 0 ||
1153 repl->counters != NULL || input_table->private != NULL) {
1154 BUGPRINT("Bad table data for ebt_register_table!!!\n");
1155 return ERR_PTR(-EINVAL);
1156 }
1157
1158 /* Don't add one table to multiple lists. */
1159 table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL);
1160 if (!table) {
1161 ret = -ENOMEM;
1162 goto out;
1163 }
1164
1165 countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
1166 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1167 ret = -ENOMEM;
1168 if (!newinfo)
1169 goto free_table;
1170
1171 p = vmalloc(repl->entries_size);
1172 if (!p)
1173 goto free_newinfo;
1174
1175 memcpy(p, repl->entries, repl->entries_size);
1176 newinfo->entries = p;
1177
1178 newinfo->entries_size = repl->entries_size;
1179 newinfo->nentries = repl->nentries;
1180
1181 if (countersize)
1182 memset(newinfo->counters, 0, countersize);
1183
1184 /* fill in newinfo and parse the entries */
1185 newinfo->chainstack = NULL;
1186 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1187 if ((repl->valid_hooks & (1 << i)) == 0)
1188 newinfo->hook_entry[i] = NULL;
1189 else
1190 newinfo->hook_entry[i] = p +
1191 ((char *)repl->hook_entry[i] - repl->entries);
1192 }
1193 ret = translate_table(net, repl->name, newinfo);
1194 if (ret != 0) {
1195 BUGPRINT("Translate_table failed\n");
1196 goto free_chainstack;
1197 }
1198
1199 if (table->check && table->check(newinfo, table->valid_hooks)) {
1200 BUGPRINT("The table doesn't like its own initial data, lol\n");
1201 return ERR_PTR(-EINVAL);
1202 }
1203
1204 table->private = newinfo;
1205 rwlock_init(&table->lock);
1206 ret = mutex_lock_interruptible(&ebt_mutex);
1207 if (ret != 0)
1208 goto free_chainstack;
1209
1210 list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
1211 if (strcmp(t->name, table->name) == 0) {
1212 ret = -EEXIST;
1213 BUGPRINT("Table name already exists\n");
1214 goto free_unlock;
1215 }
1216 }
1217
1218 /* Hold a reference count if the chains aren't empty */
1219 if (newinfo->nentries && !try_module_get(table->me)) {
1220 ret = -ENOENT;
1221 goto free_unlock;
1222 }
1223 list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
1224 mutex_unlock(&ebt_mutex);
1225 return table;
1226 free_unlock:
1227 mutex_unlock(&ebt_mutex);
1228 free_chainstack:
1229 if (newinfo->chainstack) {
1230 for_each_possible_cpu(i)
1231 vfree(newinfo->chainstack[i]);
1232 vfree(newinfo->chainstack);
1233 }
1234 vfree(newinfo->entries);
1235 free_newinfo:
1236 vfree(newinfo);
1237 free_table:
1238 kfree(table);
1239 out:
1240 return ERR_PTR(ret);
1241 }
1242
1243 void ebt_unregister_table(struct net *net, struct ebt_table *table)
1244 {
1245 int i;
1246
1247 if (!table) {
1248 BUGPRINT("Request to unregister NULL table!!!\n");
1249 return;
1250 }
1251 mutex_lock(&ebt_mutex);
1252 list_del(&table->list);
1253 mutex_unlock(&ebt_mutex);
1254 EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
1255 ebt_cleanup_entry, net, NULL);
1256 if (table->private->nentries)
1257 module_put(table->me);
1258 vfree(table->private->entries);
1259 if (table->private->chainstack) {
1260 for_each_possible_cpu(i)
1261 vfree(table->private->chainstack[i]);
1262 vfree(table->private->chainstack);
1263 }
1264 vfree(table->private);
1265 kfree(table);
1266 }
1267
1268 /* userspace just supplied us with counters */
1269 static int do_update_counters(struct net *net, const char *name,
1270 struct ebt_counter __user *counters,
1271 unsigned int num_counters,
1272 const void __user *user, unsigned int len)
1273 {
1274 int i, ret;
1275 struct ebt_counter *tmp;
1276 struct ebt_table *t;
1277
1278 if (num_counters == 0)
1279 return -EINVAL;
1280
1281 tmp = vmalloc(num_counters * sizeof(*tmp));
1282 if (!tmp)
1283 return -ENOMEM;
1284
1285 t = find_table_lock(net, name, &ret, &ebt_mutex);
1286 if (!t)
1287 goto free_tmp;
1288
1289 if (num_counters != t->private->nentries) {
1290 BUGPRINT("Wrong nr of counters\n");
1291 ret = -EINVAL;
1292 goto unlock_mutex;
1293 }
1294
1295 if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) {
1296 ret = -EFAULT;
1297 goto unlock_mutex;
1298 }
1299
1300 /* we want an atomic add of the counters */
1301 write_lock_bh(&t->lock);
1302
1303 /* we add to the counters of the first cpu */
1304 for (i = 0; i < num_counters; i++) {
1305 t->private->counters[i].pcnt += tmp[i].pcnt;
1306 t->private->counters[i].bcnt += tmp[i].bcnt;
1307 }
1308
1309 write_unlock_bh(&t->lock);
1310 ret = 0;
1311 unlock_mutex:
1312 mutex_unlock(&ebt_mutex);
1313 free_tmp:
1314 vfree(tmp);
1315 return ret;
1316 }
1317
1318 static int update_counters(struct net *net, const void __user *user,
1319 unsigned int len)
1320 {
1321 struct ebt_replace hlp;
1322
1323 if (copy_from_user(&hlp, user, sizeof(hlp)))
1324 return -EFAULT;
1325
1326 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
1327 return -EINVAL;
1328
1329 return do_update_counters(net, hlp.name, hlp.counters,
1330 hlp.num_counters, user, len);
1331 }
1332
1333 static inline int ebt_make_matchname(const struct ebt_entry_match *m,
1334 const char *base, char __user *ubase)
1335 {
1336 char __user *hlp = ubase + ((char *)m - base);
1337 if (copy_to_user(hlp, m->u.match->name, EBT_FUNCTION_MAXNAMELEN))
1338 return -EFAULT;
1339 return 0;
1340 }
1341
1342 static inline int ebt_make_watchername(const struct ebt_entry_watcher *w,
1343 const char *base, char __user *ubase)
1344 {
1345 char __user *hlp = ubase + ((char *)w - base);
1346 if (copy_to_user(hlp , w->u.watcher->name, EBT_FUNCTION_MAXNAMELEN))
1347 return -EFAULT;
1348 return 0;
1349 }
1350
1351 static inline int
1352 ebt_make_names(struct ebt_entry *e, const char *base, char __user *ubase)
1353 {
1354 int ret;
1355 char __user *hlp;
1356 const struct ebt_entry_target *t;
1357
1358 if (e->bitmask == 0)
1359 return 0;
1360
1361 hlp = ubase + (((char *)e + e->target_offset) - base);
1362 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
1363
1364 ret = EBT_MATCH_ITERATE(e, ebt_make_matchname, base, ubase);
1365 if (ret != 0)
1366 return ret;
1367 ret = EBT_WATCHER_ITERATE(e, ebt_make_watchername, base, ubase);
1368 if (ret != 0)
1369 return ret;
1370 if (copy_to_user(hlp, t->u.target->name, EBT_FUNCTION_MAXNAMELEN))
1371 return -EFAULT;
1372 return 0;
1373 }
1374
1375 static int copy_counters_to_user(struct ebt_table *t,
1376 const struct ebt_counter *oldcounters,
1377 void __user *user, unsigned int num_counters,
1378 unsigned int nentries)
1379 {
1380 struct ebt_counter *counterstmp;
1381 int ret = 0;
1382
1383 /* userspace might not need the counters */
1384 if (num_counters == 0)
1385 return 0;
1386
1387 if (num_counters != nentries) {
1388 BUGPRINT("Num_counters wrong\n");
1389 return -EINVAL;
1390 }
1391
1392 counterstmp = vmalloc(nentries * sizeof(*counterstmp));
1393 if (!counterstmp)
1394 return -ENOMEM;
1395
1396 write_lock_bh(&t->lock);
1397 get_counters(oldcounters, counterstmp, nentries);
1398 write_unlock_bh(&t->lock);
1399
1400 if (copy_to_user(user, counterstmp,
1401 nentries * sizeof(struct ebt_counter)))
1402 ret = -EFAULT;
1403 vfree(counterstmp);
1404 return ret;
1405 }
1406
1407 /* called with ebt_mutex locked */
1408 static int copy_everything_to_user(struct ebt_table *t, void __user *user,
1409 const int *len, int cmd)
1410 {
1411 struct ebt_replace tmp;
1412 const struct ebt_counter *oldcounters;
1413 unsigned int entries_size, nentries;
1414 int ret;
1415 char *entries;
1416
1417 if (cmd == EBT_SO_GET_ENTRIES) {
1418 entries_size = t->private->entries_size;
1419 nentries = t->private->nentries;
1420 entries = t->private->entries;
1421 oldcounters = t->private->counters;
1422 } else {
1423 entries_size = t->table->entries_size;
1424 nentries = t->table->nentries;
1425 entries = t->table->entries;
1426 oldcounters = t->table->counters;
1427 }
1428
1429 if (copy_from_user(&tmp, user, sizeof(tmp)))
1430 return -EFAULT;
1431
1432 if (*len != sizeof(struct ebt_replace) + entries_size +
1433 (tmp.num_counters? nentries * sizeof(struct ebt_counter): 0))
1434 return -EINVAL;
1435
1436 if (tmp.nentries != nentries) {
1437 BUGPRINT("Nentries wrong\n");
1438 return -EINVAL;
1439 }
1440
1441 if (tmp.entries_size != entries_size) {
1442 BUGPRINT("Wrong size\n");
1443 return -EINVAL;
1444 }
1445
1446 ret = copy_counters_to_user(t, oldcounters, tmp.counters,
1447 tmp.num_counters, nentries);
1448 if (ret)
1449 return ret;
1450
1451 if (copy_to_user(tmp.entries, entries, entries_size)) {
1452 BUGPRINT("Couldn't copy entries to userspace\n");
1453 return -EFAULT;
1454 }
1455 /* set the match/watcher/target names right */
1456 return EBT_ENTRY_ITERATE(entries, entries_size,
1457 ebt_make_names, entries, tmp.entries);
1458 }
1459
1460 static int do_ebt_set_ctl(struct sock *sk,
1461 int cmd, void __user *user, unsigned int len)
1462 {
1463 int ret;
1464
1465 if (!capable(CAP_NET_ADMIN))
1466 return -EPERM;
1467
1468 switch(cmd) {
1469 case EBT_SO_SET_ENTRIES:
1470 ret = do_replace(sock_net(sk), user, len);
1471 break;
1472 case EBT_SO_SET_COUNTERS:
1473 ret = update_counters(sock_net(sk), user, len);
1474 break;
1475 default:
1476 ret = -EINVAL;
1477 }
1478 return ret;
1479 }
1480
1481 static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1482 {
1483 int ret;
1484 struct ebt_replace tmp;
1485 struct ebt_table *t;
1486
1487 if (!capable(CAP_NET_ADMIN))
1488 return -EPERM;
1489
1490 if (copy_from_user(&tmp, user, sizeof(tmp)))
1491 return -EFAULT;
1492
1493 t = find_table_lock(sock_net(sk), tmp.name, &ret, &ebt_mutex);
1494 if (!t)
1495 return ret;
1496
1497 switch(cmd) {
1498 case EBT_SO_GET_INFO:
1499 case EBT_SO_GET_INIT_INFO:
1500 if (*len != sizeof(struct ebt_replace)){
1501 ret = -EINVAL;
1502 mutex_unlock(&ebt_mutex);
1503 break;
1504 }
1505 if (cmd == EBT_SO_GET_INFO) {
1506 tmp.nentries = t->private->nentries;
1507 tmp.entries_size = t->private->entries_size;
1508 tmp.valid_hooks = t->valid_hooks;
1509 } else {
1510 tmp.nentries = t->table->nentries;
1511 tmp.entries_size = t->table->entries_size;
1512 tmp.valid_hooks = t->table->valid_hooks;
1513 }
1514 mutex_unlock(&ebt_mutex);
1515 if (copy_to_user(user, &tmp, *len) != 0){
1516 BUGPRINT("c2u Didn't work\n");
1517 ret = -EFAULT;
1518 break;
1519 }
1520 ret = 0;
1521 break;
1522
1523 case EBT_SO_GET_ENTRIES:
1524 case EBT_SO_GET_INIT_ENTRIES:
1525 ret = copy_everything_to_user(t, user, len, cmd);
1526 mutex_unlock(&ebt_mutex);
1527 break;
1528
1529 default:
1530 mutex_unlock(&ebt_mutex);
1531 ret = -EINVAL;
1532 }
1533
1534 return ret;
1535 }
1536
1537 #ifdef CONFIG_COMPAT
1538 /* 32 bit-userspace compatibility definitions. */
1539 struct compat_ebt_replace {
1540 char name[EBT_TABLE_MAXNAMELEN];
1541 compat_uint_t valid_hooks;
1542 compat_uint_t nentries;
1543 compat_uint_t entries_size;
1544 /* start of the chains */
1545 compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
1546 /* nr of counters userspace expects back */
1547 compat_uint_t num_counters;
1548 /* where the kernel will put the old counters. */
1549 compat_uptr_t counters;
1550 compat_uptr_t entries;
1551 };
1552
1553 /* struct ebt_entry_match, _target and _watcher have same layout */
1554 struct compat_ebt_entry_mwt {
1555 union {
1556 char name[EBT_FUNCTION_MAXNAMELEN];
1557 compat_uptr_t ptr;
1558 } u;
1559 compat_uint_t match_size;
1560 compat_uint_t data[0];
1561 };
1562
1563 /* account for possible padding between match_size and ->data */
1564 static int ebt_compat_entry_padsize(void)
1565 {
1566 BUILD_BUG_ON(XT_ALIGN(sizeof(struct ebt_entry_match)) <
1567 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt)));
1568 return (int) XT_ALIGN(sizeof(struct ebt_entry_match)) -
1569 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt));
1570 }
1571
1572 static int ebt_compat_match_offset(const struct xt_match *match,
1573 unsigned int userlen)
1574 {
1575 /*
1576 * ebt_among needs special handling. The kernel .matchsize is
1577 * set to -1 at registration time; at runtime an EBT_ALIGN()ed
1578 * value is expected.
1579 * Example: userspace sends 4500, ebt_among.c wants 4504.
1580 */
1581 if (unlikely(match->matchsize == -1))
1582 return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
1583 return xt_compat_match_offset(match);
1584 }
1585
1586 static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
1587 unsigned int *size)
1588 {
1589 const struct xt_match *match = m->u.match;
1590 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1591 int off = ebt_compat_match_offset(match, m->match_size);
1592 compat_uint_t msize = m->match_size - off;
1593
1594 BUG_ON(off >= m->match_size);
1595
1596 if (copy_to_user(cm->u.name, match->name,
1597 strlen(match->name) + 1) || put_user(msize, &cm->match_size))
1598 return -EFAULT;
1599
1600 if (match->compat_to_user) {
1601 if (match->compat_to_user(cm->data, m->data))
1602 return -EFAULT;
1603 } else if (copy_to_user(cm->data, m->data, msize))
1604 return -EFAULT;
1605
1606 *size -= ebt_compat_entry_padsize() + off;
1607 *dstptr = cm->data;
1608 *dstptr += msize;
1609 return 0;
1610 }
1611
1612 static int compat_target_to_user(struct ebt_entry_target *t,
1613 void __user **dstptr,
1614 unsigned int *size)
1615 {
1616 const struct xt_target *target = t->u.target;
1617 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1618 int off = xt_compat_target_offset(target);
1619 compat_uint_t tsize = t->target_size - off;
1620
1621 BUG_ON(off >= t->target_size);
1622
1623 if (copy_to_user(cm->u.name, target->name,
1624 strlen(target->name) + 1) || put_user(tsize, &cm->match_size))
1625 return -EFAULT;
1626
1627 if (target->compat_to_user) {
1628 if (target->compat_to_user(cm->data, t->data))
1629 return -EFAULT;
1630 } else if (copy_to_user(cm->data, t->data, tsize))
1631 return -EFAULT;
1632
1633 *size -= ebt_compat_entry_padsize() + off;
1634 *dstptr = cm->data;
1635 *dstptr += tsize;
1636 return 0;
1637 }
1638
1639 static int compat_watcher_to_user(struct ebt_entry_watcher *w,
1640 void __user **dstptr,
1641 unsigned int *size)
1642 {
1643 return compat_target_to_user((struct ebt_entry_target *)w,
1644 dstptr, size);
1645 }
1646
1647 static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
1648 unsigned int *size)
1649 {
1650 struct ebt_entry_target *t;
1651 struct ebt_entry __user *ce;
1652 u32 watchers_offset, target_offset, next_offset;
1653 compat_uint_t origsize;
1654 int ret;
1655
1656 if (e->bitmask == 0) {
1657 if (*size < sizeof(struct ebt_entries))
1658 return -EINVAL;
1659 if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries)))
1660 return -EFAULT;
1661
1662 *dstptr += sizeof(struct ebt_entries);
1663 *size -= sizeof(struct ebt_entries);
1664 return 0;
1665 }
1666
1667 if (*size < sizeof(*ce))
1668 return -EINVAL;
1669
1670 ce = (struct ebt_entry __user *)*dstptr;
1671 if (copy_to_user(ce, e, sizeof(*ce)))
1672 return -EFAULT;
1673
1674 origsize = *size;
1675 *dstptr += sizeof(*ce);
1676
1677 ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
1678 if (ret)
1679 return ret;
1680 watchers_offset = e->watchers_offset - (origsize - *size);
1681
1682 ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
1683 if (ret)
1684 return ret;
1685 target_offset = e->target_offset - (origsize - *size);
1686
1687 t = (struct ebt_entry_target *) ((char *) e + e->target_offset);
1688
1689 ret = compat_target_to_user(t, dstptr, size);
1690 if (ret)
1691 return ret;
1692 next_offset = e->next_offset - (origsize - *size);
1693
1694 if (put_user(watchers_offset, &ce->watchers_offset) ||
1695 put_user(target_offset, &ce->target_offset) ||
1696 put_user(next_offset, &ce->next_offset))
1697 return -EFAULT;
1698
1699 *size -= sizeof(*ce);
1700 return 0;
1701 }
1702
1703 static int compat_calc_match(struct ebt_entry_match *m, int *off)
1704 {
1705 *off += ebt_compat_match_offset(m->u.match, m->match_size);
1706 *off += ebt_compat_entry_padsize();
1707 return 0;
1708 }
1709
1710 static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
1711 {
1712 *off += xt_compat_target_offset(w->u.watcher);
1713 *off += ebt_compat_entry_padsize();
1714 return 0;
1715 }
1716
1717 static int compat_calc_entry(const struct ebt_entry *e,
1718 const struct ebt_table_info *info,
1719 const void *base,
1720 struct compat_ebt_replace *newinfo)
1721 {
1722 const struct ebt_entry_target *t;
1723 unsigned int entry_offset;
1724 int off, ret, i;
1725
1726 if (e->bitmask == 0)
1727 return 0;
1728
1729 off = 0;
1730 entry_offset = (void *)e - base;
1731
1732 EBT_MATCH_ITERATE(e, compat_calc_match, &off);
1733 EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
1734
1735 t = (const struct ebt_entry_target *) ((char *) e + e->target_offset);
1736
1737 off += xt_compat_target_offset(t->u.target);
1738 off += ebt_compat_entry_padsize();
1739
1740 newinfo->entries_size -= off;
1741
1742 ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off);
1743 if (ret)
1744 return ret;
1745
1746 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1747 const void *hookptr = info->hook_entry[i];
1748 if (info->hook_entry[i] &&
1749 (e < (struct ebt_entry *)(base - hookptr))) {
1750 newinfo->hook_entry[i] -= off;
1751 pr_debug("0x%08X -> 0x%08X\n",
1752 newinfo->hook_entry[i] + off,
1753 newinfo->hook_entry[i]);
1754 }
1755 }
1756
1757 return 0;
1758 }
1759
1760
1761 static int compat_table_info(const struct ebt_table_info *info,
1762 struct compat_ebt_replace *newinfo)
1763 {
1764 unsigned int size = info->entries_size;
1765 const void *entries = info->entries;
1766
1767 newinfo->entries_size = size;
1768
1769 xt_compat_init_offsets(NFPROTO_BRIDGE, info->nentries);
1770 return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
1771 entries, newinfo);
1772 }
1773
1774 static int compat_copy_everything_to_user(struct ebt_table *t,
1775 void __user *user, int *len, int cmd)
1776 {
1777 struct compat_ebt_replace repl, tmp;
1778 struct ebt_counter *oldcounters;
1779 struct ebt_table_info tinfo;
1780 int ret;
1781 void __user *pos;
1782
1783 memset(&tinfo, 0, sizeof(tinfo));
1784
1785 if (cmd == EBT_SO_GET_ENTRIES) {
1786 tinfo.entries_size = t->private->entries_size;
1787 tinfo.nentries = t->private->nentries;
1788 tinfo.entries = t->private->entries;
1789 oldcounters = t->private->counters;
1790 } else {
1791 tinfo.entries_size = t->table->entries_size;
1792 tinfo.nentries = t->table->nentries;
1793 tinfo.entries = t->table->entries;
1794 oldcounters = t->table->counters;
1795 }
1796
1797 if (copy_from_user(&tmp, user, sizeof(tmp)))
1798 return -EFAULT;
1799
1800 if (tmp.nentries != tinfo.nentries ||
1801 (tmp.num_counters && tmp.num_counters != tinfo.nentries))
1802 return -EINVAL;
1803
1804 memcpy(&repl, &tmp, sizeof(repl));
1805 if (cmd == EBT_SO_GET_ENTRIES)
1806 ret = compat_table_info(t->private, &repl);
1807 else
1808 ret = compat_table_info(&tinfo, &repl);
1809 if (ret)
1810 return ret;
1811
1812 if (*len != sizeof(tmp) + repl.entries_size +
1813 (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
1814 pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
1815 *len, tinfo.entries_size, repl.entries_size);
1816 return -EINVAL;
1817 }
1818
1819 /* userspace might not need the counters */
1820 ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters),
1821 tmp.num_counters, tinfo.nentries);
1822 if (ret)
1823 return ret;
1824
1825 pos = compat_ptr(tmp.entries);
1826 return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
1827 compat_copy_entry_to_user, &pos, &tmp.entries_size);
1828 }
1829
1830 struct ebt_entries_buf_state {
1831 char *buf_kern_start; /* kernel buffer to copy (translated) data to */
1832 u32 buf_kern_len; /* total size of kernel buffer */
1833 u32 buf_kern_offset; /* amount of data copied so far */
1834 u32 buf_user_offset; /* read position in userspace buffer */
1835 };
1836
1837 static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
1838 {
1839 state->buf_kern_offset += sz;
1840 return state->buf_kern_offset >= sz ? 0 : -EINVAL;
1841 }
1842
1843 static int ebt_buf_add(struct ebt_entries_buf_state *state,
1844 void *data, unsigned int sz)
1845 {
1846 if (state->buf_kern_start == NULL)
1847 goto count_only;
1848
1849 BUG_ON(state->buf_kern_offset + sz > state->buf_kern_len);
1850
1851 memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz);
1852
1853 count_only:
1854 state->buf_user_offset += sz;
1855 return ebt_buf_count(state, sz);
1856 }
1857
1858 static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz)
1859 {
1860 char *b = state->buf_kern_start;
1861
1862 BUG_ON(b && state->buf_kern_offset > state->buf_kern_len);
1863
1864 if (b != NULL && sz > 0)
1865 memset(b + state->buf_kern_offset, 0, sz);
1866 /* do not adjust ->buf_user_offset here, we added kernel-side padding */
1867 return ebt_buf_count(state, sz);
1868 }
1869
1870 enum compat_mwt {
1871 EBT_COMPAT_MATCH,
1872 EBT_COMPAT_WATCHER,
1873 EBT_COMPAT_TARGET,
1874 };
1875
1876 static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt,
1877 enum compat_mwt compat_mwt,
1878 struct ebt_entries_buf_state *state,
1879 const unsigned char *base)
1880 {
1881 char name[EBT_FUNCTION_MAXNAMELEN];
1882 struct xt_match *match;
1883 struct xt_target *wt;
1884 void *dst = NULL;
1885 int off, pad = 0;
1886 unsigned int size_kern, entry_offset, match_size = mwt->match_size;
1887
1888 strlcpy(name, mwt->u.name, sizeof(name));
1889
1890 if (state->buf_kern_start)
1891 dst = state->buf_kern_start + state->buf_kern_offset;
1892
1893 entry_offset = (unsigned char *) mwt - base;
1894 switch (compat_mwt) {
1895 case EBT_COMPAT_MATCH:
1896 match = try_then_request_module(xt_find_match(NFPROTO_BRIDGE,
1897 name, 0), "ebt_%s", name);
1898 if (match == NULL)
1899 return -ENOENT;
1900 if (IS_ERR(match))
1901 return PTR_ERR(match);
1902
1903 off = ebt_compat_match_offset(match, match_size);
1904 if (dst) {
1905 if (match->compat_from_user)
1906 match->compat_from_user(dst, mwt->data);
1907 else
1908 memcpy(dst, mwt->data, match_size);
1909 }
1910
1911 size_kern = match->matchsize;
1912 if (unlikely(size_kern == -1))
1913 size_kern = match_size;
1914 module_put(match->me);
1915 break;
1916 case EBT_COMPAT_WATCHER: /* fallthrough */
1917 case EBT_COMPAT_TARGET:
1918 wt = try_then_request_module(xt_find_target(NFPROTO_BRIDGE,
1919 name, 0), "ebt_%s", name);
1920 if (wt == NULL)
1921 return -ENOENT;
1922 if (IS_ERR(wt))
1923 return PTR_ERR(wt);
1924 off = xt_compat_target_offset(wt);
1925
1926 if (dst) {
1927 if (wt->compat_from_user)
1928 wt->compat_from_user(dst, mwt->data);
1929 else
1930 memcpy(dst, mwt->data, match_size);
1931 }
1932
1933 size_kern = wt->targetsize;
1934 module_put(wt->me);
1935 break;
1936 }
1937
1938 state->buf_kern_offset += match_size + off;
1939 state->buf_user_offset += match_size;
1940 pad = XT_ALIGN(size_kern) - size_kern;
1941
1942 if (pad > 0 && dst) {
1943 BUG_ON(state->buf_kern_len <= pad);
1944 BUG_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad);
1945 memset(dst + size_kern, 0, pad);
1946 }
1947 return off + match_size;
1948 }
1949
1950 /*
1951 * return size of all matches, watchers or target, including necessary
1952 * alignment and padding.
1953 */
1954 static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32,
1955 unsigned int size_left, enum compat_mwt type,
1956 struct ebt_entries_buf_state *state, const void *base)
1957 {
1958 int growth = 0;
1959 char *buf;
1960
1961 if (size_left == 0)
1962 return 0;
1963
1964 buf = (char *) match32;
1965
1966 while (size_left >= sizeof(*match32)) {
1967 struct ebt_entry_match *match_kern;
1968 int ret;
1969
1970 match_kern = (struct ebt_entry_match *) state->buf_kern_start;
1971 if (match_kern) {
1972 char *tmp;
1973 tmp = state->buf_kern_start + state->buf_kern_offset;
1974 match_kern = (struct ebt_entry_match *) tmp;
1975 }
1976 ret = ebt_buf_add(state, buf, sizeof(*match32));
1977 if (ret < 0)
1978 return ret;
1979 size_left -= sizeof(*match32);
1980
1981 /* add padding before match->data (if any) */
1982 ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize());
1983 if (ret < 0)
1984 return ret;
1985
1986 if (match32->match_size > size_left)
1987 return -EINVAL;
1988
1989 size_left -= match32->match_size;
1990
1991 ret = compat_mtw_from_user(match32, type, state, base);
1992 if (ret < 0)
1993 return ret;
1994
1995 BUG_ON(ret < match32->match_size);
1996 growth += ret - match32->match_size;
1997 growth += ebt_compat_entry_padsize();
1998
1999 buf += sizeof(*match32);
2000 buf += match32->match_size;
2001
2002 if (match_kern)
2003 match_kern->match_size = ret;
2004
2005 WARN_ON(type == EBT_COMPAT_TARGET && size_left);
2006 match32 = (struct compat_ebt_entry_mwt *) buf;
2007 }
2008
2009 return growth;
2010 }
2011
2012 /* called for all ebt_entry structures. */
2013 static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,
2014 unsigned int *total,
2015 struct ebt_entries_buf_state *state)
2016 {
2017 unsigned int i, j, startoff, new_offset = 0;
2018 /* stores match/watchers/targets & offset of next struct ebt_entry: */
2019 unsigned int offsets[4];
2020 unsigned int *offsets_update = NULL;
2021 int ret;
2022 char *buf_start;
2023
2024 if (*total < sizeof(struct ebt_entries))
2025 return -EINVAL;
2026
2027 if (!entry->bitmask) {
2028 *total -= sizeof(struct ebt_entries);
2029 return ebt_buf_add(state, entry, sizeof(struct ebt_entries));
2030 }
2031 if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
2032 return -EINVAL;
2033
2034 startoff = state->buf_user_offset;
2035 /* pull in most part of ebt_entry, it does not need to be changed. */
2036 ret = ebt_buf_add(state, entry,
2037 offsetof(struct ebt_entry, watchers_offset));
2038 if (ret < 0)
2039 return ret;
2040
2041 offsets[0] = sizeof(struct ebt_entry); /* matches come first */
2042 memcpy(&offsets[1], &entry->watchers_offset,
2043 sizeof(offsets) - sizeof(offsets[0]));
2044
2045 if (state->buf_kern_start) {
2046 buf_start = state->buf_kern_start + state->buf_kern_offset;
2047 offsets_update = (unsigned int *) buf_start;
2048 }
2049 ret = ebt_buf_add(state, &offsets[1],
2050 sizeof(offsets) - sizeof(offsets[0]));
2051 if (ret < 0)
2052 return ret;
2053 buf_start = (char *) entry;
2054 /*
2055 * 0: matches offset, always follows ebt_entry.
2056 * 1: watchers offset, from ebt_entry structure
2057 * 2: target offset, from ebt_entry structure
2058 * 3: next ebt_entry offset, from ebt_entry structure
2059 *
2060 * offsets are relative to beginning of struct ebt_entry (i.e., 0).
2061 */
2062 for (i = 0, j = 1 ; j < 4 ; j++, i++) {
2063 struct compat_ebt_entry_mwt *match32;
2064 unsigned int size;
2065 char *buf = buf_start;
2066
2067 buf = buf_start + offsets[i];
2068 if (offsets[i] > offsets[j])
2069 return -EINVAL;
2070
2071 match32 = (struct compat_ebt_entry_mwt *) buf;
2072 size = offsets[j] - offsets[i];
2073 ret = ebt_size_mwt(match32, size, i, state, base);
2074 if (ret < 0)
2075 return ret;
2076 new_offset += ret;
2077 if (offsets_update && new_offset) {
2078 pr_debug("change offset %d to %d\n",
2079 offsets_update[i], offsets[j] + new_offset);
2080 offsets_update[i] = offsets[j] + new_offset;
2081 }
2082 }
2083
2084 if (state->buf_kern_start == NULL) {
2085 unsigned int offset = buf_start - (char *) base;
2086
2087 ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);
2088 if (ret < 0)
2089 return ret;
2090 }
2091
2092 startoff = state->buf_user_offset - startoff;
2093
2094 BUG_ON(*total < startoff);
2095 *total -= startoff;
2096 return 0;
2097 }
2098
2099 /*
2100 * repl->entries_size is the size of the ebt_entry blob in userspace.
2101 * It might need more memory when copied to a 64 bit kernel in case
2102 * userspace is 32-bit. So, first task: find out how much memory is needed.
2103 *
2104 * Called before validation is performed.
2105 */
2106 static int compat_copy_entries(unsigned char *data, unsigned int size_user,
2107 struct ebt_entries_buf_state *state)
2108 {
2109 unsigned int size_remaining = size_user;
2110 int ret;
2111
2112 ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
2113 &size_remaining, state);
2114 if (ret < 0)
2115 return ret;
2116
2117 WARN_ON(size_remaining);
2118 return state->buf_kern_offset;
2119 }
2120
2121
2122 static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
2123 void __user *user, unsigned int len)
2124 {
2125 struct compat_ebt_replace tmp;
2126 int i;
2127
2128 if (len < sizeof(tmp))
2129 return -EINVAL;
2130
2131 if (copy_from_user(&tmp, user, sizeof(tmp)))
2132 return -EFAULT;
2133
2134 if (len != sizeof(tmp) + tmp.entries_size)
2135 return -EINVAL;
2136
2137 if (tmp.entries_size == 0)
2138 return -EINVAL;
2139
2140 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
2141 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
2142 return -ENOMEM;
2143 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
2144 return -ENOMEM;
2145
2146 memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
2147
2148 /* starting with hook_entry, 32 vs. 64 bit structures are different */
2149 for (i = 0; i < NF_BR_NUMHOOKS; i++)
2150 repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]);
2151
2152 repl->num_counters = tmp.num_counters;
2153 repl->counters = compat_ptr(tmp.counters);
2154 repl->entries = compat_ptr(tmp.entries);
2155 return 0;
2156 }
2157
2158 static int compat_do_replace(struct net *net, void __user *user,
2159 unsigned int len)
2160 {
2161 int ret, i, countersize, size64;
2162 struct ebt_table_info *newinfo;
2163 struct ebt_replace tmp;
2164 struct ebt_entries_buf_state state;
2165 void *entries_tmp;
2166
2167 ret = compat_copy_ebt_replace_from_user(&tmp, user, len);
2168 if (ret) {
2169 /* try real handler in case userland supplied needed padding */
2170 if (ret == -EINVAL && do_replace(net, user, len) == 0)
2171 ret = 0;
2172 return ret;
2173 }
2174
2175 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
2176 newinfo = vmalloc(sizeof(*newinfo) + countersize);
2177 if (!newinfo)
2178 return -ENOMEM;
2179
2180 if (countersize)
2181 memset(newinfo->counters, 0, countersize);
2182
2183 memset(&state, 0, sizeof(state));
2184
2185 newinfo->entries = vmalloc(tmp.entries_size);
2186 if (!newinfo->entries) {
2187 ret = -ENOMEM;
2188 goto free_newinfo;
2189 }
2190 if (copy_from_user(
2191 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
2192 ret = -EFAULT;
2193 goto free_entries;
2194 }
2195
2196 entries_tmp = newinfo->entries;
2197
2198 xt_compat_lock(NFPROTO_BRIDGE);
2199
2200 xt_compat_init_offsets(NFPROTO_BRIDGE, tmp.nentries);
2201 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2202 if (ret < 0)
2203 goto out_unlock;
2204
2205 pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
2206 tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
2207 xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
2208
2209 size64 = ret;
2210 newinfo->entries = vmalloc(size64);
2211 if (!newinfo->entries) {
2212 vfree(entries_tmp);
2213 ret = -ENOMEM;
2214 goto out_unlock;
2215 }
2216
2217 memset(&state, 0, sizeof(state));
2218 state.buf_kern_start = newinfo->entries;
2219 state.buf_kern_len = size64;
2220
2221 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2222 BUG_ON(ret < 0); /* parses same data again */
2223
2224 vfree(entries_tmp);
2225 tmp.entries_size = size64;
2226
2227 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
2228 char __user *usrptr;
2229 if (tmp.hook_entry[i]) {
2230 unsigned int delta;
2231 usrptr = (char __user *) tmp.hook_entry[i];
2232 delta = usrptr - tmp.entries;
2233 usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta);
2234 tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
2235 }
2236 }
2237
2238 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2239 xt_compat_unlock(NFPROTO_BRIDGE);
2240
2241 ret = do_replace_finish(net, &tmp, newinfo);
2242 if (ret == 0)
2243 return ret;
2244 free_entries:
2245 vfree(newinfo->entries);
2246 free_newinfo:
2247 vfree(newinfo);
2248 return ret;
2249 out_unlock:
2250 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2251 xt_compat_unlock(NFPROTO_BRIDGE);
2252 goto free_entries;
2253 }
2254
2255 static int compat_update_counters(struct net *net, void __user *user,
2256 unsigned int len)
2257 {
2258 struct compat_ebt_replace hlp;
2259
2260 if (copy_from_user(&hlp, user, sizeof(hlp)))
2261 return -EFAULT;
2262
2263 /* try real handler in case userland supplied needed padding */
2264 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
2265 return update_counters(net, user, len);
2266
2267 return do_update_counters(net, hlp.name, compat_ptr(hlp.counters),
2268 hlp.num_counters, user, len);
2269 }
2270
2271 static int compat_do_ebt_set_ctl(struct sock *sk,
2272 int cmd, void __user *user, unsigned int len)
2273 {
2274 int ret;
2275
2276 if (!capable(CAP_NET_ADMIN))
2277 return -EPERM;
2278
2279 switch (cmd) {
2280 case EBT_SO_SET_ENTRIES:
2281 ret = compat_do_replace(sock_net(sk), user, len);
2282 break;
2283 case EBT_SO_SET_COUNTERS:
2284 ret = compat_update_counters(sock_net(sk), user, len);
2285 break;
2286 default:
2287 ret = -EINVAL;
2288 }
2289 return ret;
2290 }
2291
2292 static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
2293 void __user *user, int *len)
2294 {
2295 int ret;
2296 struct compat_ebt_replace tmp;
2297 struct ebt_table *t;
2298
2299 if (!capable(CAP_NET_ADMIN))
2300 return -EPERM;
2301
2302 /* try real handler in case userland supplied needed padding */
2303 if ((cmd == EBT_SO_GET_INFO ||
2304 cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp))
2305 return do_ebt_get_ctl(sk, cmd, user, len);
2306
2307 if (copy_from_user(&tmp, user, sizeof(tmp)))
2308 return -EFAULT;
2309
2310 t = find_table_lock(sock_net(sk), tmp.name, &ret, &ebt_mutex);
2311 if (!t)
2312 return ret;
2313
2314 xt_compat_lock(NFPROTO_BRIDGE);
2315 switch (cmd) {
2316 case EBT_SO_GET_INFO:
2317 tmp.nentries = t->private->nentries;
2318 ret = compat_table_info(t->private, &tmp);
2319 if (ret)
2320 goto out;
2321 tmp.valid_hooks = t->valid_hooks;
2322
2323 if (copy_to_user(user, &tmp, *len) != 0) {
2324 ret = -EFAULT;
2325 break;
2326 }
2327 ret = 0;
2328 break;
2329 case EBT_SO_GET_INIT_INFO:
2330 tmp.nentries = t->table->nentries;
2331 tmp.entries_size = t->table->entries_size;
2332 tmp.valid_hooks = t->table->valid_hooks;
2333
2334 if (copy_to_user(user, &tmp, *len) != 0) {
2335 ret = -EFAULT;
2336 break;
2337 }
2338 ret = 0;
2339 break;
2340 case EBT_SO_GET_ENTRIES:
2341 case EBT_SO_GET_INIT_ENTRIES:
2342 /*
2343 * try real handler first in case of userland-side padding.
2344 * in case we are dealing with an 'ordinary' 32 bit binary
2345 * without 64bit compatibility padding, this will fail right
2346 * after copy_from_user when the *len argument is validated.
2347 *
2348 * the compat_ variant needs to do one pass over the kernel
2349 * data set to adjust for size differences before it the check.
2350 */
2351 if (copy_everything_to_user(t, user, len, cmd) == 0)
2352 ret = 0;
2353 else
2354 ret = compat_copy_everything_to_user(t, user, len, cmd);
2355 break;
2356 default:
2357 ret = -EINVAL;
2358 }
2359 out:
2360 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2361 xt_compat_unlock(NFPROTO_BRIDGE);
2362 mutex_unlock(&ebt_mutex);
2363 return ret;
2364 }
2365 #endif
2366
2367 static struct nf_sockopt_ops ebt_sockopts =
2368 {
2369 .pf = PF_INET,
2370 .set_optmin = EBT_BASE_CTL,
2371 .set_optmax = EBT_SO_SET_MAX + 1,
2372 .set = do_ebt_set_ctl,
2373 #ifdef CONFIG_COMPAT
2374 .compat_set = compat_do_ebt_set_ctl,
2375 #endif
2376 .get_optmin = EBT_BASE_CTL,
2377 .get_optmax = EBT_SO_GET_MAX + 1,
2378 .get = do_ebt_get_ctl,
2379 #ifdef CONFIG_COMPAT
2380 .compat_get = compat_do_ebt_get_ctl,
2381 #endif
2382 .owner = THIS_MODULE,
2383 };
2384
2385 static int __init ebtables_init(void)
2386 {
2387 int ret;
2388
2389 ret = xt_register_target(&ebt_standard_target);
2390 if (ret < 0)
2391 return ret;
2392 ret = nf_register_sockopt(&ebt_sockopts);
2393 if (ret < 0) {
2394 xt_unregister_target(&ebt_standard_target);
2395 return ret;
2396 }
2397
2398 printk(KERN_INFO "Ebtables v2.0 registered\n");
2399 return 0;
2400 }
2401
2402 static void __exit ebtables_fini(void)
2403 {
2404 nf_unregister_sockopt(&ebt_sockopts);
2405 xt_unregister_target(&ebt_standard_target);
2406 printk(KERN_INFO "Ebtables v2.0 unregistered\n");
2407 }
2408
2409 EXPORT_SYMBOL(ebt_register_table);
2410 EXPORT_SYMBOL(ebt_unregister_table);
2411 EXPORT_SYMBOL(ebt_do_table);
2412 module_init(ebtables_init);
2413 module_exit(ebtables_fini);
2414 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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