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Linux 4.19.133
[linux/fpc-iii.git] / net / bridge / netfilter / ebtables.c
blobf59230e4fc2956ea178c1c78890f4963a5fecc87
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 <linux/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 /* Each cpu has its own set of counters, so there is no need for write_lock in
35 * the softirq
36 * For reading or updating the counters, the user context needs to
37 * get a write_lock
38 */
39
40 /* The size of each set of counters is altered to get cache alignment */
41 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
42 #define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter)))
43 #define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \
44 COUNTER_OFFSET(n) * cpu))
45
46
47
48 static DEFINE_MUTEX(ebt_mutex);
49
50 #ifdef CONFIG_COMPAT
51 static void ebt_standard_compat_from_user(void *dst, const void *src)
52 {
53 int v = *(compat_int_t *)src;
54
55 if (v >= 0)
56 v += xt_compat_calc_jump(NFPROTO_BRIDGE, v);
57 memcpy(dst, &v, sizeof(v));
58 }
59
60 static int ebt_standard_compat_to_user(void __user *dst, const void *src)
61 {
62 compat_int_t cv = *(int *)src;
63
64 if (cv >= 0)
65 cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv);
66 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
67 }
68 #endif
69
70
71 static struct xt_target ebt_standard_target = {
72 .name = "standard",
73 .revision = 0,
74 .family = NFPROTO_BRIDGE,
75 .targetsize = sizeof(int),
76 #ifdef CONFIG_COMPAT
77 .compatsize = sizeof(compat_int_t),
78 .compat_from_user = ebt_standard_compat_from_user,
79 .compat_to_user = ebt_standard_compat_to_user,
80 #endif
81 };
82
83 static inline int
84 ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb,
85 struct xt_action_param *par)
86 {
87 par->target = w->u.watcher;
88 par->targinfo = w->data;
89 w->u.watcher->target(skb, par);
90 /* watchers don't give a verdict */
91 return 0;
92 }
93
94 static inline int
95 ebt_do_match(struct ebt_entry_match *m, const struct sk_buff *skb,
96 struct xt_action_param *par)
97 {
98 par->match = m->u.match;
99 par->matchinfo = m->data;
100 return !m->u.match->match(skb, par);
101 }
102
103 static inline int
104 ebt_dev_check(const char *entry, const struct net_device *device)
105 {
106 int i = 0;
107 const char *devname;
108
109 if (*entry == '\0')
110 return 0;
111 if (!device)
112 return 1;
113 devname = device->name;
114 /* 1 is the wildcard token */
115 while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i])
116 i++;
117 return devname[i] != entry[i] && entry[i] != 1;
118 }
119
120 /* process standard matches */
121 static inline int
122 ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb,
123 const struct net_device *in, const struct net_device *out)
124 {
125 const struct ethhdr *h = eth_hdr(skb);
126 const struct net_bridge_port *p;
127 __be16 ethproto;
128
129 if (skb_vlan_tag_present(skb))
130 ethproto = htons(ETH_P_8021Q);
131 else
132 ethproto = h->h_proto;
133
134 if (e->bitmask & EBT_802_3) {
135 if (NF_INVF(e, EBT_IPROTO, eth_proto_is_802_3(ethproto)))
136 return 1;
137 } else if (!(e->bitmask & EBT_NOPROTO) &&
138 NF_INVF(e, EBT_IPROTO, e->ethproto != ethproto))
139 return 1;
140
141 if (NF_INVF(e, EBT_IIN, ebt_dev_check(e->in, in)))
142 return 1;
143 if (NF_INVF(e, EBT_IOUT, ebt_dev_check(e->out, out)))
144 return 1;
145 /* rcu_read_lock()ed by nf_hook_thresh */
146 if (in && (p = br_port_get_rcu(in)) != NULL &&
147 NF_INVF(e, EBT_ILOGICALIN,
148 ebt_dev_check(e->logical_in, p->br->dev)))
149 return 1;
150 if (out && (p = br_port_get_rcu(out)) != NULL &&
151 NF_INVF(e, EBT_ILOGICALOUT,
152 ebt_dev_check(e->logical_out, p->br->dev)))
153 return 1;
154
155 if (e->bitmask & EBT_SOURCEMAC) {
156 if (NF_INVF(e, EBT_ISOURCE,
157 !ether_addr_equal_masked(h->h_source, e->sourcemac,
158 e->sourcemsk)))
159 return 1;
160 }
161 if (e->bitmask & EBT_DESTMAC) {
162 if (NF_INVF(e, EBT_IDEST,
163 !ether_addr_equal_masked(h->h_dest, e->destmac,
164 e->destmsk)))
165 return 1;
166 }
167 return 0;
168 }
169
170 static inline
171 struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry)
172 {
173 return (void *)entry + entry->next_offset;
174 }
175
176 static inline const struct ebt_entry_target *
177 ebt_get_target_c(const struct ebt_entry *e)
178 {
179 return ebt_get_target((struct ebt_entry *)e);
180 }
181
182 /* Do some firewalling */
183 unsigned int ebt_do_table(struct sk_buff *skb,
184 const struct nf_hook_state *state,
185 struct ebt_table *table)
186 {
187 unsigned int hook = state->hook;
188 int i, nentries;
189 struct ebt_entry *point;
190 struct ebt_counter *counter_base, *cb_base;
191 const struct ebt_entry_target *t;
192 int verdict, sp = 0;
193 struct ebt_chainstack *cs;
194 struct ebt_entries *chaininfo;
195 const char *base;
196 const struct ebt_table_info *private;
197 struct xt_action_param acpar;
198
199 acpar.state = state;
200 acpar.hotdrop = false;
201
202 read_lock_bh(&table->lock);
203 private = table->private;
204 cb_base = COUNTER_BASE(private->counters, private->nentries,
205 smp_processor_id());
206 if (private->chainstack)
207 cs = private->chainstack[smp_processor_id()];
208 else
209 cs = NULL;
210 chaininfo = private->hook_entry[hook];
211 nentries = private->hook_entry[hook]->nentries;
212 point = (struct ebt_entry *)(private->hook_entry[hook]->data);
213 counter_base = cb_base + private->hook_entry[hook]->counter_offset;
214 /* base for chain jumps */
215 base = private->entries;
216 i = 0;
217 while (i < nentries) {
218 if (ebt_basic_match(point, skb, state->in, state->out))
219 goto letscontinue;
220
221 if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0)
222 goto letscontinue;
223 if (acpar.hotdrop) {
224 read_unlock_bh(&table->lock);
225 return NF_DROP;
226 }
227
228 ADD_COUNTER(*(counter_base + i), skb->len, 1);
229
230 /* these should only watch: not modify, nor tell us
231 * what to do with the packet
232 */
233 EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar);
234
235 t = ebt_get_target_c(point);
236 /* standard target */
237 if (!t->u.target->target)
238 verdict = ((struct ebt_standard_target *)t)->verdict;
239 else {
240 acpar.target = t->u.target;
241 acpar.targinfo = t->data;
242 verdict = t->u.target->target(skb, &acpar);
243 }
244 if (verdict == EBT_ACCEPT) {
245 read_unlock_bh(&table->lock);
246 return NF_ACCEPT;
247 }
248 if (verdict == EBT_DROP) {
249 read_unlock_bh(&table->lock);
250 return NF_DROP;
251 }
252 if (verdict == EBT_RETURN) {
253 letsreturn:
254 if (WARN(sp == 0, "RETURN on base chain")) {
255 /* act like this is EBT_CONTINUE */
256 goto letscontinue;
257 }
258
259 sp--;
260 /* put all the local variables right */
261 i = cs[sp].n;
262 chaininfo = cs[sp].chaininfo;
263 nentries = chaininfo->nentries;
264 point = cs[sp].e;
265 counter_base = cb_base +
266 chaininfo->counter_offset;
267 continue;
268 }
269 if (verdict == EBT_CONTINUE)
270 goto letscontinue;
271
272 if (WARN(verdict < 0, "bogus standard verdict\n")) {
273 read_unlock_bh(&table->lock);
274 return NF_DROP;
275 }
276
277 /* jump to a udc */
278 cs[sp].n = i + 1;
279 cs[sp].chaininfo = chaininfo;
280 cs[sp].e = ebt_next_entry(point);
281 i = 0;
282 chaininfo = (struct ebt_entries *) (base + verdict);
283
284 if (WARN(chaininfo->distinguisher, "jump to non-chain\n")) {
285 read_unlock_bh(&table->lock);
286 return NF_DROP;
287 }
288
289 nentries = chaininfo->nentries;
290 point = (struct ebt_entry *)chaininfo->data;
291 counter_base = cb_base + chaininfo->counter_offset;
292 sp++;
293 continue;
294 letscontinue:
295 point = ebt_next_entry(point);
296 i++;
297 }
298
299 /* I actually like this :) */
300 if (chaininfo->policy == EBT_RETURN)
301 goto letsreturn;
302 if (chaininfo->policy == EBT_ACCEPT) {
303 read_unlock_bh(&table->lock);
304 return NF_ACCEPT;
305 }
306 read_unlock_bh(&table->lock);
307 return NF_DROP;
308 }
309
310 /* If it succeeds, returns element and locks mutex */
311 static inline void *
312 find_inlist_lock_noload(struct list_head *head, const char *name, int *error,
313 struct mutex *mutex)
314 {
315 struct {
316 struct list_head list;
317 char name[EBT_FUNCTION_MAXNAMELEN];
318 } *e;
319
320 mutex_lock(mutex);
321 list_for_each_entry(e, head, list) {
322 if (strcmp(e->name, name) == 0)
323 return e;
324 }
325 *error = -ENOENT;
326 mutex_unlock(mutex);
327 return NULL;
328 }
329
330 static void *
331 find_inlist_lock(struct list_head *head, const char *name, const char *prefix,
332 int *error, struct mutex *mutex)
333 {
334 return try_then_request_module(
335 find_inlist_lock_noload(head, name, error, mutex),
336 "%s%s", prefix, name);
337 }
338
339 static inline struct ebt_table *
340 find_table_lock(struct net *net, const char *name, int *error,
341 struct mutex *mutex)
342 {
343 return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name,
344 "ebtable_", error, mutex);
345 }
346
347 static inline void ebt_free_table_info(struct ebt_table_info *info)
348 {
349 int i;
350
351 if (info->chainstack) {
352 for_each_possible_cpu(i)
353 vfree(info->chainstack[i]);
354 vfree(info->chainstack);
355 }
356 }
357 static inline int
358 ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
359 unsigned int *cnt)
360 {
361 const struct ebt_entry *e = par->entryinfo;
362 struct xt_match *match;
363 size_t left = ((char *)e + e->watchers_offset) - (char *)m;
364 int ret;
365
366 if (left < sizeof(struct ebt_entry_match) ||
367 left - sizeof(struct ebt_entry_match) < m->match_size)
368 return -EINVAL;
369
370 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision);
371 if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) {
372 if (!IS_ERR(match))
373 module_put(match->me);
374 request_module("ebt_%s", m->u.name);
375 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision);
376 }
377 if (IS_ERR(match))
378 return PTR_ERR(match);
379 m->u.match = match;
380
381 par->match = match;
382 par->matchinfo = m->data;
383 ret = xt_check_match(par, m->match_size,
384 e->ethproto, e->invflags & EBT_IPROTO);
385 if (ret < 0) {
386 module_put(match->me);
387 return ret;
388 }
389
390 (*cnt)++;
391 return 0;
392 }
393
394 static inline int
395 ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
396 unsigned int *cnt)
397 {
398 const struct ebt_entry *e = par->entryinfo;
399 struct xt_target *watcher;
400 size_t left = ((char *)e + e->target_offset) - (char *)w;
401 int ret;
402
403 if (left < sizeof(struct ebt_entry_watcher) ||
404 left - sizeof(struct ebt_entry_watcher) < w->watcher_size)
405 return -EINVAL;
406
407 watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0);
408 if (IS_ERR(watcher))
409 return PTR_ERR(watcher);
410
411 if (watcher->family != NFPROTO_BRIDGE) {
412 module_put(watcher->me);
413 return -ENOENT;
414 }
415
416 w->u.watcher = watcher;
417
418 par->target = watcher;
419 par->targinfo = w->data;
420 ret = xt_check_target(par, w->watcher_size,
421 e->ethproto, e->invflags & EBT_IPROTO);
422 if (ret < 0) {
423 module_put(watcher->me);
424 return ret;
425 }
426
427 (*cnt)++;
428 return 0;
429 }
430
431 static int ebt_verify_pointers(const struct ebt_replace *repl,
432 struct ebt_table_info *newinfo)
433 {
434 unsigned int limit = repl->entries_size;
435 unsigned int valid_hooks = repl->valid_hooks;
436 unsigned int offset = 0;
437 int i;
438
439 for (i = 0; i < NF_BR_NUMHOOKS; i++)
440 newinfo->hook_entry[i] = NULL;
441
442 newinfo->entries_size = repl->entries_size;
443 newinfo->nentries = repl->nentries;
444
445 while (offset < limit) {
446 size_t left = limit - offset;
447 struct ebt_entry *e = (void *)newinfo->entries + offset;
448
449 if (left < sizeof(unsigned int))
450 break;
451
452 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
453 if ((valid_hooks & (1 << i)) == 0)
454 continue;
455 if ((char __user *)repl->hook_entry[i] ==
456 repl->entries + offset)
457 break;
458 }
459
460 if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
461 if (e->bitmask != 0) {
462 /* we make userspace set this right,
463 * so there is no misunderstanding
464 */
465 return -EINVAL;
466 }
467 if (i != NF_BR_NUMHOOKS)
468 newinfo->hook_entry[i] = (struct ebt_entries *)e;
469 if (left < sizeof(struct ebt_entries))
470 break;
471 offset += sizeof(struct ebt_entries);
472 } else {
473 if (left < sizeof(struct ebt_entry))
474 break;
475 if (left < e->next_offset)
476 break;
477 if (e->next_offset < sizeof(struct ebt_entry))
478 return -EINVAL;
479 offset += e->next_offset;
480 }
481 }
482 if (offset != limit)
483 return -EINVAL;
484
485 /* check if all valid hooks have a chain */
486 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
487 if (!newinfo->hook_entry[i] &&
488 (valid_hooks & (1 << i)))
489 return -EINVAL;
490 }
491 return 0;
492 }
493
494 /* this one is very careful, as it is the first function
495 * to parse the userspace data
496 */
497 static inline int
498 ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
499 const struct ebt_table_info *newinfo,
500 unsigned int *n, unsigned int *cnt,
501 unsigned int *totalcnt, unsigned int *udc_cnt)
502 {
503 int i;
504
505 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
506 if ((void *)e == (void *)newinfo->hook_entry[i])
507 break;
508 }
509 /* beginning of a new chain
510 * if i == NF_BR_NUMHOOKS it must be a user defined chain
511 */
512 if (i != NF_BR_NUMHOOKS || !e->bitmask) {
513 /* this checks if the previous chain has as many entries
514 * as it said it has
515 */
516 if (*n != *cnt)
517 return -EINVAL;
518
519 if (((struct ebt_entries *)e)->policy != EBT_DROP &&
520 ((struct ebt_entries *)e)->policy != EBT_ACCEPT) {
521 /* only RETURN from udc */
522 if (i != NF_BR_NUMHOOKS ||
523 ((struct ebt_entries *)e)->policy != EBT_RETURN)
524 return -EINVAL;
525 }
526 if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */
527 (*udc_cnt)++;
528 if (((struct ebt_entries *)e)->counter_offset != *totalcnt)
529 return -EINVAL;
530 *n = ((struct ebt_entries *)e)->nentries;
531 *cnt = 0;
532 return 0;
533 }
534 /* a plain old entry, heh */
535 if (sizeof(struct ebt_entry) > e->watchers_offset ||
536 e->watchers_offset > e->target_offset ||
537 e->target_offset >= e->next_offset)
538 return -EINVAL;
539
540 /* this is not checked anywhere else */
541 if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target))
542 return -EINVAL;
543
544 (*cnt)++;
545 (*totalcnt)++;
546 return 0;
547 }
548
549 struct ebt_cl_stack {
550 struct ebt_chainstack cs;
551 int from;
552 unsigned int hookmask;
553 };
554
555 /* We need these positions to check that the jumps to a different part of the
556 * entries is a jump to the beginning of a new chain.
557 */
558 static inline int
559 ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo,
560 unsigned int *n, struct ebt_cl_stack *udc)
561 {
562 int i;
563
564 /* we're only interested in chain starts */
565 if (e->bitmask)
566 return 0;
567 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
568 if (newinfo->hook_entry[i] == (struct ebt_entries *)e)
569 break;
570 }
571 /* only care about udc */
572 if (i != NF_BR_NUMHOOKS)
573 return 0;
574
575 udc[*n].cs.chaininfo = (struct ebt_entries *)e;
576 /* these initialisations are depended on later in check_chainloops() */
577 udc[*n].cs.n = 0;
578 udc[*n].hookmask = 0;
579
580 (*n)++;
581 return 0;
582 }
583
584 static inline int
585 ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i)
586 {
587 struct xt_mtdtor_param par;
588
589 if (i && (*i)-- == 0)
590 return 1;
591
592 par.net = net;
593 par.match = m->u.match;
594 par.matchinfo = m->data;
595 par.family = NFPROTO_BRIDGE;
596 if (par.match->destroy != NULL)
597 par.match->destroy(&par);
598 module_put(par.match->me);
599 return 0;
600 }
601
602 static inline int
603 ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i)
604 {
605 struct xt_tgdtor_param par;
606
607 if (i && (*i)-- == 0)
608 return 1;
609
610 par.net = net;
611 par.target = w->u.watcher;
612 par.targinfo = w->data;
613 par.family = NFPROTO_BRIDGE;
614 if (par.target->destroy != NULL)
615 par.target->destroy(&par);
616 module_put(par.target->me);
617 return 0;
618 }
619
620 static inline int
621 ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
622 {
623 struct xt_tgdtor_param par;
624 struct ebt_entry_target *t;
625
626 if (e->bitmask == 0)
627 return 0;
628 /* we're done */
629 if (cnt && (*cnt)-- == 0)
630 return 1;
631 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL);
632 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL);
633 t = ebt_get_target(e);
634
635 par.net = net;
636 par.target = t->u.target;
637 par.targinfo = t->data;
638 par.family = NFPROTO_BRIDGE;
639 if (par.target->destroy != NULL)
640 par.target->destroy(&par);
641 module_put(par.target->me);
642 return 0;
643 }
644
645 static inline int
646 ebt_check_entry(struct ebt_entry *e, struct net *net,
647 const struct ebt_table_info *newinfo,
648 const char *name, unsigned int *cnt,
649 struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
650 {
651 struct ebt_entry_target *t;
652 struct xt_target *target;
653 unsigned int i, j, hook = 0, hookmask = 0;
654 size_t gap;
655 int ret;
656 struct xt_mtchk_param mtpar;
657 struct xt_tgchk_param tgpar;
658
659 /* don't mess with the struct ebt_entries */
660 if (e->bitmask == 0)
661 return 0;
662
663 if (e->bitmask & ~EBT_F_MASK)
664 return -EINVAL;
665
666 if (e->invflags & ~EBT_INV_MASK)
667 return -EINVAL;
668
669 if ((e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3))
670 return -EINVAL;
671
672 /* what hook do we belong to? */
673 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
674 if (!newinfo->hook_entry[i])
675 continue;
676 if ((char *)newinfo->hook_entry[i] < (char *)e)
677 hook = i;
678 else
679 break;
680 }
681 /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on
682 * a base chain
683 */
684 if (i < NF_BR_NUMHOOKS)
685 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
686 else {
687 for (i = 0; i < udc_cnt; i++)
688 if ((char *)(cl_s[i].cs.chaininfo) > (char *)e)
689 break;
690 if (i == 0)
691 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
692 else
693 hookmask = cl_s[i - 1].hookmask;
694 }
695 i = 0;
696
697 memset(&mtpar, 0, sizeof(mtpar));
698 memset(&tgpar, 0, sizeof(tgpar));
699 mtpar.net = tgpar.net = net;
700 mtpar.table = tgpar.table = name;
701 mtpar.entryinfo = tgpar.entryinfo = e;
702 mtpar.hook_mask = tgpar.hook_mask = hookmask;
703 mtpar.family = tgpar.family = NFPROTO_BRIDGE;
704 ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i);
705 if (ret != 0)
706 goto cleanup_matches;
707 j = 0;
708 ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j);
709 if (ret != 0)
710 goto cleanup_watchers;
711 t = ebt_get_target(e);
712 gap = e->next_offset - e->target_offset;
713
714 target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0);
715 if (IS_ERR(target)) {
716 ret = PTR_ERR(target);
717 goto cleanup_watchers;
718 }
719
720 /* Reject UNSPEC, xtables verdicts/return values are incompatible */
721 if (target->family != NFPROTO_BRIDGE) {
722 module_put(target->me);
723 ret = -ENOENT;
724 goto cleanup_watchers;
725 }
726
727 t->u.target = target;
728 if (t->u.target == &ebt_standard_target) {
729 if (gap < sizeof(struct ebt_standard_target)) {
730 ret = -EFAULT;
731 goto cleanup_watchers;
732 }
733 if (((struct ebt_standard_target *)t)->verdict <
734 -NUM_STANDARD_TARGETS) {
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 /* checks for loops and sets the hook mask for udc
762 * the hook mask for udc tells us from which base chains the udc can be
763 * accessed. This mask is a parameter to the check() functions of the extensions
764 */
765 static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
766 unsigned int udc_cnt, unsigned int hooknr, char *base)
767 {
768 int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
769 const struct ebt_entry *e = (struct ebt_entry *)chain->data;
770 const struct ebt_entry_target *t;
771
772 while (pos < nentries || chain_nr != -1) {
773 /* end of udc, go back one 'recursion' step */
774 if (pos == nentries) {
775 /* put back values of the time when this chain was called */
776 e = cl_s[chain_nr].cs.e;
777 if (cl_s[chain_nr].from != -1)
778 nentries =
779 cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries;
780 else
781 nentries = chain->nentries;
782 pos = cl_s[chain_nr].cs.n;
783 /* make sure we won't see a loop that isn't one */
784 cl_s[chain_nr].cs.n = 0;
785 chain_nr = cl_s[chain_nr].from;
786 if (pos == nentries)
787 continue;
788 }
789 t = ebt_get_target_c(e);
790 if (strcmp(t->u.name, EBT_STANDARD_TARGET))
791 goto letscontinue;
792 if (e->target_offset + sizeof(struct ebt_standard_target) >
793 e->next_offset)
794 return -1;
795
796 verdict = ((struct ebt_standard_target *)t)->verdict;
797 if (verdict >= 0) { /* jump to another chain */
798 struct ebt_entries *hlp2 =
799 (struct ebt_entries *)(base + verdict);
800 for (i = 0; i < udc_cnt; i++)
801 if (hlp2 == cl_s[i].cs.chaininfo)
802 break;
803 /* bad destination or loop */
804 if (i == udc_cnt)
805 return -1;
806
807 if (cl_s[i].cs.n)
808 return -1;
809
810 if (cl_s[i].hookmask & (1 << hooknr))
811 goto letscontinue;
812 /* this can't be 0, so the loop test is correct */
813 cl_s[i].cs.n = pos + 1;
814 pos = 0;
815 cl_s[i].cs.e = ebt_next_entry(e);
816 e = (struct ebt_entry *)(hlp2->data);
817 nentries = hlp2->nentries;
818 cl_s[i].from = chain_nr;
819 chain_nr = i;
820 /* this udc is accessible from the base chain for hooknr */
821 cl_s[i].hookmask |= (1 << hooknr);
822 continue;
823 }
824 letscontinue:
825 e = ebt_next_entry(e);
826 pos++;
827 }
828 return 0;
829 }
830
831 /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
832 static int translate_table(struct net *net, const char *name,
833 struct ebt_table_info *newinfo)
834 {
835 unsigned int i, j, k, udc_cnt;
836 int ret;
837 struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */
838
839 i = 0;
840 while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i])
841 i++;
842 if (i == NF_BR_NUMHOOKS)
843 return -EINVAL;
844
845 if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries)
846 return -EINVAL;
847
848 /* make sure chains are ordered after each other in same order
849 * as their corresponding hooks
850 */
851 for (j = i + 1; j < NF_BR_NUMHOOKS; j++) {
852 if (!newinfo->hook_entry[j])
853 continue;
854 if (newinfo->hook_entry[j] <= newinfo->hook_entry[i])
855 return -EINVAL;
856
857 i = j;
858 }
859
860 /* do some early checkings and initialize some things */
861 i = 0; /* holds the expected nr. of entries for the chain */
862 j = 0; /* holds the up to now counted entries for the chain */
863 k = 0; /* holds the total nr. of entries, should equal
864 * newinfo->nentries afterwards
865 */
866 udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */
867 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
868 ebt_check_entry_size_and_hooks, newinfo,
869 &i, &j, &k, &udc_cnt);
870
871 if (ret != 0)
872 return ret;
873
874 if (i != j)
875 return -EINVAL;
876
877 if (k != newinfo->nentries)
878 return -EINVAL;
879
880 /* get the location of the udc, put them in an array
881 * while we're at it, allocate the chainstack
882 */
883 if (udc_cnt) {
884 /* this will get free'd in do_replace()/ebt_register_table()
885 * if an error occurs
886 */
887 newinfo->chainstack =
888 vmalloc(array_size(nr_cpu_ids,
889 sizeof(*(newinfo->chainstack))));
890 if (!newinfo->chainstack)
891 return -ENOMEM;
892 for_each_possible_cpu(i) {
893 newinfo->chainstack[i] =
894 vmalloc(array_size(udc_cnt, sizeof(*(newinfo->chainstack[0]))));
895 if (!newinfo->chainstack[i]) {
896 while (i)
897 vfree(newinfo->chainstack[--i]);
898 vfree(newinfo->chainstack);
899 newinfo->chainstack = NULL;
900 return -ENOMEM;
901 }
902 }
903
904 cl_s = vmalloc(array_size(udc_cnt, sizeof(*cl_s)));
905 if (!cl_s)
906 return -ENOMEM;
907 i = 0; /* the i'th udc */
908 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
909 ebt_get_udc_positions, newinfo, &i, cl_s);
910 /* sanity check */
911 if (i != udc_cnt) {
912 vfree(cl_s);
913 return -EFAULT;
914 }
915 }
916
917 /* Check for loops */
918 for (i = 0; i < NF_BR_NUMHOOKS; i++)
919 if (newinfo->hook_entry[i])
920 if (check_chainloops(newinfo->hook_entry[i],
921 cl_s, udc_cnt, i, newinfo->entries)) {
922 vfree(cl_s);
923 return -EINVAL;
924 }
925
926 /* we now know the following (along with E=mc²):
927 * - the nr of entries in each chain is right
928 * - the size of the allocated space is right
929 * - all valid hooks have a corresponding chain
930 * - there are no loops
931 * - wrong data can still be on the level of a single entry
932 * - could be there are jumps to places that are not the
933 * beginning of a chain. This can only occur in chains that
934 * are not accessible from any base chains, so we don't care.
935 */
936
937 /* used to know what we need to clean up if something goes wrong */
938 i = 0;
939 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
940 ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt);
941 if (ret != 0) {
942 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
943 ebt_cleanup_entry, net, &i);
944 }
945 vfree(cl_s);
946 return ret;
947 }
948
949 /* called under write_lock */
950 static void get_counters(const struct ebt_counter *oldcounters,
951 struct ebt_counter *counters, unsigned int nentries)
952 {
953 int i, cpu;
954 struct ebt_counter *counter_base;
955
956 /* counters of cpu 0 */
957 memcpy(counters, oldcounters,
958 sizeof(struct ebt_counter) * nentries);
959
960 /* add other counters to those of cpu 0 */
961 for_each_possible_cpu(cpu) {
962 if (cpu == 0)
963 continue;
964 counter_base = COUNTER_BASE(oldcounters, nentries, cpu);
965 for (i = 0; i < nentries; i++)
966 ADD_COUNTER(counters[i], counter_base[i].bcnt,
967 counter_base[i].pcnt);
968 }
969 }
970
971 static int do_replace_finish(struct net *net, struct ebt_replace *repl,
972 struct ebt_table_info *newinfo)
973 {
974 int ret;
975 struct ebt_counter *counterstmp = NULL;
976 /* used to be able to unlock earlier */
977 struct ebt_table_info *table;
978 struct ebt_table *t;
979
980 /* the user wants counters back
981 * the check on the size is done later, when we have the lock
982 */
983 if (repl->num_counters) {
984 unsigned long size = repl->num_counters * sizeof(*counterstmp);
985 counterstmp = vmalloc(size);
986 if (!counterstmp)
987 return -ENOMEM;
988 }
989
990 newinfo->chainstack = NULL;
991 ret = ebt_verify_pointers(repl, newinfo);
992 if (ret != 0)
993 goto free_counterstmp;
994
995 ret = translate_table(net, repl->name, newinfo);
996
997 if (ret != 0)
998 goto free_counterstmp;
999
1000 t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
1001 if (!t) {
1002 ret = -ENOENT;
1003 goto free_iterate;
1004 }
1005
1006 /* the table doesn't like it */
1007 if (t->check && (ret = t->check(newinfo, repl->valid_hooks)))
1008 goto free_unlock;
1009
1010 if (repl->num_counters && repl->num_counters != t->private->nentries) {
1011 ret = -EINVAL;
1012 goto free_unlock;
1013 }
1014
1015 /* we have the mutex lock, so no danger in reading this pointer */
1016 table = t->private;
1017 /* make sure the table can only be rmmod'ed if it contains no rules */
1018 if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) {
1019 ret = -ENOENT;
1020 goto free_unlock;
1021 } else if (table->nentries && !newinfo->nentries)
1022 module_put(t->me);
1023 /* we need an atomic snapshot of the counters */
1024 write_lock_bh(&t->lock);
1025 if (repl->num_counters)
1026 get_counters(t->private->counters, counterstmp,
1027 t->private->nentries);
1028
1029 t->private = newinfo;
1030 write_unlock_bh(&t->lock);
1031 mutex_unlock(&ebt_mutex);
1032 /* so, a user can change the chains while having messed up her counter
1033 * allocation. Only reason why this is done is because this way the lock
1034 * is held only once, while this doesn't bring the kernel into a
1035 * dangerous state.
1036 */
1037 if (repl->num_counters &&
1038 copy_to_user(repl->counters, counterstmp,
1039 repl->num_counters * sizeof(struct ebt_counter))) {
1040 /* Silent error, can't fail, new table is already in place */
1041 net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n");
1042 }
1043
1044 /* decrease module count and free resources */
1045 EBT_ENTRY_ITERATE(table->entries, table->entries_size,
1046 ebt_cleanup_entry, net, NULL);
1047
1048 vfree(table->entries);
1049 ebt_free_table_info(table);
1050 vfree(table);
1051 vfree(counterstmp);
1052
1053 #ifdef CONFIG_AUDIT
1054 if (audit_enabled) {
1055 audit_log(audit_context(), GFP_KERNEL,
1056 AUDIT_NETFILTER_CFG,
1057 "table=%s family=%u entries=%u",
1058 repl->name, AF_BRIDGE, repl->nentries);
1059 }
1060 #endif
1061 return ret;
1062
1063 free_unlock:
1064 mutex_unlock(&ebt_mutex);
1065 free_iterate:
1066 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
1067 ebt_cleanup_entry, net, NULL);
1068 free_counterstmp:
1069 vfree(counterstmp);
1070 /* can be initialized in translate_table() */
1071 ebt_free_table_info(newinfo);
1072 return ret;
1073 }
1074
1075 /* replace the table */
1076 static int do_replace(struct net *net, const void __user *user,
1077 unsigned int len)
1078 {
1079 int ret, countersize;
1080 struct ebt_table_info *newinfo;
1081 struct ebt_replace tmp;
1082
1083 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1084 return -EFAULT;
1085
1086 if (len != sizeof(tmp) + tmp.entries_size)
1087 return -EINVAL;
1088
1089 if (tmp.entries_size == 0)
1090 return -EINVAL;
1091
1092 /* overflow check */
1093 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
1094 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
1095 return -ENOMEM;
1096 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
1097 return -ENOMEM;
1098
1099 tmp.name[sizeof(tmp.name) - 1] = 0;
1100
1101 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
1102 newinfo = __vmalloc(sizeof(*newinfo) + countersize, GFP_KERNEL_ACCOUNT,
1103 PAGE_KERNEL);
1104 if (!newinfo)
1105 return -ENOMEM;
1106
1107 if (countersize)
1108 memset(newinfo->counters, 0, countersize);
1109
1110 newinfo->entries = __vmalloc(tmp.entries_size, GFP_KERNEL_ACCOUNT,
1111 PAGE_KERNEL);
1112 if (!newinfo->entries) {
1113 ret = -ENOMEM;
1114 goto free_newinfo;
1115 }
1116 if (copy_from_user(
1117 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
1118 ret = -EFAULT;
1119 goto free_entries;
1120 }
1121
1122 ret = do_replace_finish(net, &tmp, newinfo);
1123 if (ret == 0)
1124 return ret;
1125 free_entries:
1126 vfree(newinfo->entries);
1127 free_newinfo:
1128 vfree(newinfo);
1129 return ret;
1130 }
1131
1132 static void __ebt_unregister_table(struct net *net, struct ebt_table *table)
1133 {
1134 mutex_lock(&ebt_mutex);
1135 list_del(&table->list);
1136 mutex_unlock(&ebt_mutex);
1137 EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
1138 ebt_cleanup_entry, net, NULL);
1139 if (table->private->nentries)
1140 module_put(table->me);
1141 vfree(table->private->entries);
1142 ebt_free_table_info(table->private);
1143 vfree(table->private);
1144 kfree(table);
1145 }
1146
1147 int ebt_register_table(struct net *net, const struct ebt_table *input_table,
1148 const struct nf_hook_ops *ops, struct ebt_table **res)
1149 {
1150 struct ebt_table_info *newinfo;
1151 struct ebt_table *t, *table;
1152 struct ebt_replace_kernel *repl;
1153 int ret, i, countersize;
1154 void *p;
1155
1156 if (input_table == NULL || (repl = input_table->table) == NULL ||
1157 repl->entries == NULL || repl->entries_size == 0 ||
1158 repl->counters != NULL || input_table->private != NULL)
1159 return -EINVAL;
1160
1161 /* Don't add one table to multiple lists. */
1162 table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL);
1163 if (!table) {
1164 ret = -ENOMEM;
1165 goto out;
1166 }
1167
1168 countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
1169 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1170 ret = -ENOMEM;
1171 if (!newinfo)
1172 goto free_table;
1173
1174 p = vmalloc(repl->entries_size);
1175 if (!p)
1176 goto free_newinfo;
1177
1178 memcpy(p, repl->entries, repl->entries_size);
1179 newinfo->entries = p;
1180
1181 newinfo->entries_size = repl->entries_size;
1182 newinfo->nentries = repl->nentries;
1183
1184 if (countersize)
1185 memset(newinfo->counters, 0, countersize);
1186
1187 /* fill in newinfo and parse the entries */
1188 newinfo->chainstack = NULL;
1189 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1190 if ((repl->valid_hooks & (1 << i)) == 0)
1191 newinfo->hook_entry[i] = NULL;
1192 else
1193 newinfo->hook_entry[i] = p +
1194 ((char *)repl->hook_entry[i] - repl->entries);
1195 }
1196 ret = translate_table(net, repl->name, newinfo);
1197 if (ret != 0)
1198 goto free_chainstack;
1199
1200 if (table->check && table->check(newinfo, table->valid_hooks)) {
1201 ret = -EINVAL;
1202 goto free_chainstack;
1203 }
1204
1205 table->private = newinfo;
1206 rwlock_init(&table->lock);
1207 mutex_lock(&ebt_mutex);
1208 list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
1209 if (strcmp(t->name, table->name) == 0) {
1210 ret = -EEXIST;
1211 goto free_unlock;
1212 }
1213 }
1214
1215 /* Hold a reference count if the chains aren't empty */
1216 if (newinfo->nentries && !try_module_get(table->me)) {
1217 ret = -ENOENT;
1218 goto free_unlock;
1219 }
1220 list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
1221 mutex_unlock(&ebt_mutex);
1222
1223 WRITE_ONCE(*res, table);
1224
1225 if (!ops)
1226 return 0;
1227
1228 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
1229 if (ret) {
1230 __ebt_unregister_table(net, table);
1231 *res = NULL;
1232 }
1233
1234 return ret;
1235 free_unlock:
1236 mutex_unlock(&ebt_mutex);
1237 free_chainstack:
1238 ebt_free_table_info(newinfo);
1239 vfree(newinfo->entries);
1240 free_newinfo:
1241 vfree(newinfo);
1242 free_table:
1243 kfree(table);
1244 out:
1245 return ret;
1246 }
1247
1248 void ebt_unregister_table(struct net *net, struct ebt_table *table,
1249 const struct nf_hook_ops *ops)
1250 {
1251 if (ops)
1252 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
1253 __ebt_unregister_table(net, table);
1254 }
1255
1256 /* userspace just supplied us with counters */
1257 static int do_update_counters(struct net *net, const char *name,
1258 struct ebt_counter __user *counters,
1259 unsigned int num_counters,
1260 const void __user *user, unsigned int len)
1261 {
1262 int i, ret;
1263 struct ebt_counter *tmp;
1264 struct ebt_table *t;
1265
1266 if (num_counters == 0)
1267 return -EINVAL;
1268
1269 tmp = vmalloc(array_size(num_counters, sizeof(*tmp)));
1270 if (!tmp)
1271 return -ENOMEM;
1272
1273 t = find_table_lock(net, name, &ret, &ebt_mutex);
1274 if (!t)
1275 goto free_tmp;
1276
1277 if (num_counters != t->private->nentries) {
1278 ret = -EINVAL;
1279 goto unlock_mutex;
1280 }
1281
1282 if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) {
1283 ret = -EFAULT;
1284 goto unlock_mutex;
1285 }
1286
1287 /* we want an atomic add of the counters */
1288 write_lock_bh(&t->lock);
1289
1290 /* we add to the counters of the first cpu */
1291 for (i = 0; i < num_counters; i++)
1292 ADD_COUNTER(t->private->counters[i], tmp[i].bcnt, tmp[i].pcnt);
1293
1294 write_unlock_bh(&t->lock);
1295 ret = 0;
1296 unlock_mutex:
1297 mutex_unlock(&ebt_mutex);
1298 free_tmp:
1299 vfree(tmp);
1300 return ret;
1301 }
1302
1303 static int update_counters(struct net *net, const void __user *user,
1304 unsigned int len)
1305 {
1306 struct ebt_replace hlp;
1307
1308 if (copy_from_user(&hlp, user, sizeof(hlp)))
1309 return -EFAULT;
1310
1311 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
1312 return -EINVAL;
1313
1314 return do_update_counters(net, hlp.name, hlp.counters,
1315 hlp.num_counters, user, len);
1316 }
1317
1318 static inline int ebt_obj_to_user(char __user *um, const char *_name,
1319 const char *data, int entrysize,
1320 int usersize, int datasize, u8 revision)
1321 {
1322 char name[EBT_EXTENSION_MAXNAMELEN] = {0};
1323
1324 /* ebtables expects 31 bytes long names but xt_match names are 29 bytes
1325 * long. Copy 29 bytes and fill remaining bytes with zeroes.
1326 */
1327 strlcpy(name, _name, sizeof(name));
1328 if (copy_to_user(um, name, EBT_EXTENSION_MAXNAMELEN) ||
1329 put_user(revision, (u8 __user *)(um + EBT_EXTENSION_MAXNAMELEN)) ||
1330 put_user(datasize, (int __user *)(um + EBT_EXTENSION_MAXNAMELEN + 1)) ||
1331 xt_data_to_user(um + entrysize, data, usersize, datasize,
1332 XT_ALIGN(datasize)))
1333 return -EFAULT;
1334
1335 return 0;
1336 }
1337
1338 static inline int ebt_match_to_user(const struct ebt_entry_match *m,
1339 const char *base, char __user *ubase)
1340 {
1341 return ebt_obj_to_user(ubase + ((char *)m - base),
1342 m->u.match->name, m->data, sizeof(*m),
1343 m->u.match->usersize, m->match_size,
1344 m->u.match->revision);
1345 }
1346
1347 static inline int ebt_watcher_to_user(const struct ebt_entry_watcher *w,
1348 const char *base, char __user *ubase)
1349 {
1350 return ebt_obj_to_user(ubase + ((char *)w - base),
1351 w->u.watcher->name, w->data, sizeof(*w),
1352 w->u.watcher->usersize, w->watcher_size,
1353 w->u.watcher->revision);
1354 }
1355
1356 static inline int ebt_entry_to_user(struct ebt_entry *e, const char *base,
1357 char __user *ubase)
1358 {
1359 int ret;
1360 char __user *hlp;
1361 const struct ebt_entry_target *t;
1362
1363 if (e->bitmask == 0) {
1364 /* special case !EBT_ENTRY_OR_ENTRIES */
1365 if (copy_to_user(ubase + ((char *)e - base), e,
1366 sizeof(struct ebt_entries)))
1367 return -EFAULT;
1368 return 0;
1369 }
1370
1371 if (copy_to_user(ubase + ((char *)e - base), e, sizeof(*e)))
1372 return -EFAULT;
1373
1374 hlp = ubase + (((char *)e + e->target_offset) - base);
1375 t = ebt_get_target_c(e);
1376
1377 ret = EBT_MATCH_ITERATE(e, ebt_match_to_user, base, ubase);
1378 if (ret != 0)
1379 return ret;
1380 ret = EBT_WATCHER_ITERATE(e, ebt_watcher_to_user, base, ubase);
1381 if (ret != 0)
1382 return ret;
1383 ret = ebt_obj_to_user(hlp, t->u.target->name, t->data, sizeof(*t),
1384 t->u.target->usersize, t->target_size,
1385 t->u.target->revision);
1386 if (ret != 0)
1387 return ret;
1388
1389 return 0;
1390 }
1391
1392 static int copy_counters_to_user(struct ebt_table *t,
1393 const struct ebt_counter *oldcounters,
1394 void __user *user, unsigned int num_counters,
1395 unsigned int nentries)
1396 {
1397 struct ebt_counter *counterstmp;
1398 int ret = 0;
1399
1400 /* userspace might not need the counters */
1401 if (num_counters == 0)
1402 return 0;
1403
1404 if (num_counters != nentries)
1405 return -EINVAL;
1406
1407 counterstmp = vmalloc(array_size(nentries, sizeof(*counterstmp)));
1408 if (!counterstmp)
1409 return -ENOMEM;
1410
1411 write_lock_bh(&t->lock);
1412 get_counters(oldcounters, counterstmp, nentries);
1413 write_unlock_bh(&t->lock);
1414
1415 if (copy_to_user(user, counterstmp,
1416 nentries * sizeof(struct ebt_counter)))
1417 ret = -EFAULT;
1418 vfree(counterstmp);
1419 return ret;
1420 }
1421
1422 /* called with ebt_mutex locked */
1423 static int copy_everything_to_user(struct ebt_table *t, void __user *user,
1424 const int *len, int cmd)
1425 {
1426 struct ebt_replace tmp;
1427 const struct ebt_counter *oldcounters;
1428 unsigned int entries_size, nentries;
1429 int ret;
1430 char *entries;
1431
1432 if (cmd == EBT_SO_GET_ENTRIES) {
1433 entries_size = t->private->entries_size;
1434 nentries = t->private->nentries;
1435 entries = t->private->entries;
1436 oldcounters = t->private->counters;
1437 } else {
1438 entries_size = t->table->entries_size;
1439 nentries = t->table->nentries;
1440 entries = t->table->entries;
1441 oldcounters = t->table->counters;
1442 }
1443
1444 if (copy_from_user(&tmp, user, sizeof(tmp)))
1445 return -EFAULT;
1446
1447 if (*len != sizeof(struct ebt_replace) + entries_size +
1448 (tmp.num_counters ? nentries * sizeof(struct ebt_counter) : 0))
1449 return -EINVAL;
1450
1451 if (tmp.nentries != nentries)
1452 return -EINVAL;
1453
1454 if (tmp.entries_size != entries_size)
1455 return -EINVAL;
1456
1457 ret = copy_counters_to_user(t, oldcounters, tmp.counters,
1458 tmp.num_counters, nentries);
1459 if (ret)
1460 return ret;
1461
1462 /* set the match/watcher/target names right */
1463 return EBT_ENTRY_ITERATE(entries, entries_size,
1464 ebt_entry_to_user, entries, tmp.entries);
1465 }
1466
1467 static int do_ebt_set_ctl(struct sock *sk,
1468 int cmd, void __user *user, unsigned int len)
1469 {
1470 int ret;
1471 struct net *net = sock_net(sk);
1472
1473 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1474 return -EPERM;
1475
1476 switch (cmd) {
1477 case EBT_SO_SET_ENTRIES:
1478 ret = do_replace(net, user, len);
1479 break;
1480 case EBT_SO_SET_COUNTERS:
1481 ret = update_counters(net, user, len);
1482 break;
1483 default:
1484 ret = -EINVAL;
1485 }
1486 return ret;
1487 }
1488
1489 static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1490 {
1491 int ret;
1492 struct ebt_replace tmp;
1493 struct ebt_table *t;
1494 struct net *net = sock_net(sk);
1495
1496 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1497 return -EPERM;
1498
1499 if (copy_from_user(&tmp, user, sizeof(tmp)))
1500 return -EFAULT;
1501
1502 tmp.name[sizeof(tmp.name) - 1] = '\0';
1503
1504 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
1505 if (!t)
1506 return ret;
1507
1508 switch (cmd) {
1509 case EBT_SO_GET_INFO:
1510 case EBT_SO_GET_INIT_INFO:
1511 if (*len != sizeof(struct ebt_replace)) {
1512 ret = -EINVAL;
1513 mutex_unlock(&ebt_mutex);
1514 break;
1515 }
1516 if (cmd == EBT_SO_GET_INFO) {
1517 tmp.nentries = t->private->nentries;
1518 tmp.entries_size = t->private->entries_size;
1519 tmp.valid_hooks = t->valid_hooks;
1520 } else {
1521 tmp.nentries = t->table->nentries;
1522 tmp.entries_size = t->table->entries_size;
1523 tmp.valid_hooks = t->table->valid_hooks;
1524 }
1525 mutex_unlock(&ebt_mutex);
1526 if (copy_to_user(user, &tmp, *len) != 0) {
1527 ret = -EFAULT;
1528 break;
1529 }
1530 ret = 0;
1531 break;
1532
1533 case EBT_SO_GET_ENTRIES:
1534 case EBT_SO_GET_INIT_ENTRIES:
1535 ret = copy_everything_to_user(t, user, len, cmd);
1536 mutex_unlock(&ebt_mutex);
1537 break;
1538
1539 default:
1540 mutex_unlock(&ebt_mutex);
1541 ret = -EINVAL;
1542 }
1543
1544 return ret;
1545 }
1546
1547 #ifdef CONFIG_COMPAT
1548 /* 32 bit-userspace compatibility definitions. */
1549 struct compat_ebt_replace {
1550 char name[EBT_TABLE_MAXNAMELEN];
1551 compat_uint_t valid_hooks;
1552 compat_uint_t nentries;
1553 compat_uint_t entries_size;
1554 /* start of the chains */
1555 compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
1556 /* nr of counters userspace expects back */
1557 compat_uint_t num_counters;
1558 /* where the kernel will put the old counters. */
1559 compat_uptr_t counters;
1560 compat_uptr_t entries;
1561 };
1562
1563 /* struct ebt_entry_match, _target and _watcher have same layout */
1564 struct compat_ebt_entry_mwt {
1565 union {
1566 struct {
1567 char name[EBT_EXTENSION_MAXNAMELEN];
1568 u8 revision;
1569 };
1570 compat_uptr_t ptr;
1571 } u;
1572 compat_uint_t match_size;
1573 compat_uint_t data[0] __attribute__ ((aligned (__alignof__(struct compat_ebt_replace))));
1574 };
1575
1576 /* account for possible padding between match_size and ->data */
1577 static int ebt_compat_entry_padsize(void)
1578 {
1579 BUILD_BUG_ON(sizeof(struct ebt_entry_match) <
1580 sizeof(struct compat_ebt_entry_mwt));
1581 return (int) sizeof(struct ebt_entry_match) -
1582 sizeof(struct compat_ebt_entry_mwt);
1583 }
1584
1585 static int ebt_compat_match_offset(const struct xt_match *match,
1586 unsigned int userlen)
1587 {
1588 /* ebt_among needs special handling. The kernel .matchsize is
1589 * set to -1 at registration time; at runtime an EBT_ALIGN()ed
1590 * value is expected.
1591 * Example: userspace sends 4500, ebt_among.c wants 4504.
1592 */
1593 if (unlikely(match->matchsize == -1))
1594 return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
1595 return xt_compat_match_offset(match);
1596 }
1597
1598 static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
1599 unsigned int *size)
1600 {
1601 const struct xt_match *match = m->u.match;
1602 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1603 int off = ebt_compat_match_offset(match, m->match_size);
1604 compat_uint_t msize = m->match_size - off;
1605
1606 if (WARN_ON(off >= m->match_size))
1607 return -EINVAL;
1608
1609 if (copy_to_user(cm->u.name, match->name, strlen(match->name) + 1) ||
1610 put_user(match->revision, &cm->u.revision) ||
1611 put_user(msize, &cm->match_size))
1612 return -EFAULT;
1613
1614 if (match->compat_to_user) {
1615 if (match->compat_to_user(cm->data, m->data))
1616 return -EFAULT;
1617 } else {
1618 if (xt_data_to_user(cm->data, m->data, match->usersize, msize,
1619 COMPAT_XT_ALIGN(msize)))
1620 return -EFAULT;
1621 }
1622
1623 *size -= ebt_compat_entry_padsize() + off;
1624 *dstptr = cm->data;
1625 *dstptr += msize;
1626 return 0;
1627 }
1628
1629 static int compat_target_to_user(struct ebt_entry_target *t,
1630 void __user **dstptr,
1631 unsigned int *size)
1632 {
1633 const struct xt_target *target = t->u.target;
1634 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1635 int off = xt_compat_target_offset(target);
1636 compat_uint_t tsize = t->target_size - off;
1637
1638 if (WARN_ON(off >= t->target_size))
1639 return -EINVAL;
1640
1641 if (copy_to_user(cm->u.name, target->name, strlen(target->name) + 1) ||
1642 put_user(target->revision, &cm->u.revision) ||
1643 put_user(tsize, &cm->match_size))
1644 return -EFAULT;
1645
1646 if (target->compat_to_user) {
1647 if (target->compat_to_user(cm->data, t->data))
1648 return -EFAULT;
1649 } else {
1650 if (xt_data_to_user(cm->data, t->data, target->usersize, tsize,
1651 COMPAT_XT_ALIGN(tsize)))
1652 return -EFAULT;
1653 }
1654
1655 *size -= ebt_compat_entry_padsize() + off;
1656 *dstptr = cm->data;
1657 *dstptr += tsize;
1658 return 0;
1659 }
1660
1661 static int compat_watcher_to_user(struct ebt_entry_watcher *w,
1662 void __user **dstptr,
1663 unsigned int *size)
1664 {
1665 return compat_target_to_user((struct ebt_entry_target *)w,
1666 dstptr, size);
1667 }
1668
1669 static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
1670 unsigned int *size)
1671 {
1672 struct ebt_entry_target *t;
1673 struct ebt_entry __user *ce;
1674 u32 watchers_offset, target_offset, next_offset;
1675 compat_uint_t origsize;
1676 int ret;
1677
1678 if (e->bitmask == 0) {
1679 if (*size < sizeof(struct ebt_entries))
1680 return -EINVAL;
1681 if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries)))
1682 return -EFAULT;
1683
1684 *dstptr += sizeof(struct ebt_entries);
1685 *size -= sizeof(struct ebt_entries);
1686 return 0;
1687 }
1688
1689 if (*size < sizeof(*ce))
1690 return -EINVAL;
1691
1692 ce = *dstptr;
1693 if (copy_to_user(ce, e, sizeof(*ce)))
1694 return -EFAULT;
1695
1696 origsize = *size;
1697 *dstptr += sizeof(*ce);
1698
1699 ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
1700 if (ret)
1701 return ret;
1702 watchers_offset = e->watchers_offset - (origsize - *size);
1703
1704 ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
1705 if (ret)
1706 return ret;
1707 target_offset = e->target_offset - (origsize - *size);
1708
1709 t = ebt_get_target(e);
1710
1711 ret = compat_target_to_user(t, dstptr, size);
1712 if (ret)
1713 return ret;
1714 next_offset = e->next_offset - (origsize - *size);
1715
1716 if (put_user(watchers_offset, &ce->watchers_offset) ||
1717 put_user(target_offset, &ce->target_offset) ||
1718 put_user(next_offset, &ce->next_offset))
1719 return -EFAULT;
1720
1721 *size -= sizeof(*ce);
1722 return 0;
1723 }
1724
1725 static int compat_calc_match(struct ebt_entry_match *m, int *off)
1726 {
1727 *off += ebt_compat_match_offset(m->u.match, m->match_size);
1728 *off += ebt_compat_entry_padsize();
1729 return 0;
1730 }
1731
1732 static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
1733 {
1734 *off += xt_compat_target_offset(w->u.watcher);
1735 *off += ebt_compat_entry_padsize();
1736 return 0;
1737 }
1738
1739 static int compat_calc_entry(const struct ebt_entry *e,
1740 const struct ebt_table_info *info,
1741 const void *base,
1742 struct compat_ebt_replace *newinfo)
1743 {
1744 const struct ebt_entry_target *t;
1745 unsigned int entry_offset;
1746 int off, ret, i;
1747
1748 if (e->bitmask == 0)
1749 return 0;
1750
1751 off = 0;
1752 entry_offset = (void *)e - base;
1753
1754 EBT_MATCH_ITERATE(e, compat_calc_match, &off);
1755 EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
1756
1757 t = ebt_get_target_c(e);
1758
1759 off += xt_compat_target_offset(t->u.target);
1760 off += ebt_compat_entry_padsize();
1761
1762 newinfo->entries_size -= off;
1763
1764 ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off);
1765 if (ret)
1766 return ret;
1767
1768 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1769 const void *hookptr = info->hook_entry[i];
1770 if (info->hook_entry[i] &&
1771 (e < (struct ebt_entry *)(base - hookptr))) {
1772 newinfo->hook_entry[i] -= off;
1773 pr_debug("0x%08X -> 0x%08X\n",
1774 newinfo->hook_entry[i] + off,
1775 newinfo->hook_entry[i]);
1776 }
1777 }
1778
1779 return 0;
1780 }
1781
1782 static int ebt_compat_init_offsets(unsigned int number)
1783 {
1784 if (number > INT_MAX)
1785 return -EINVAL;
1786
1787 /* also count the base chain policies */
1788 number += NF_BR_NUMHOOKS;
1789
1790 return xt_compat_init_offsets(NFPROTO_BRIDGE, number);
1791 }
1792
1793 static int compat_table_info(const struct ebt_table_info *info,
1794 struct compat_ebt_replace *newinfo)
1795 {
1796 unsigned int size = info->entries_size;
1797 const void *entries = info->entries;
1798 int ret;
1799
1800 newinfo->entries_size = size;
1801 ret = ebt_compat_init_offsets(info->nentries);
1802 if (ret)
1803 return ret;
1804
1805 return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
1806 entries, newinfo);
1807 }
1808
1809 static int compat_copy_everything_to_user(struct ebt_table *t,
1810 void __user *user, int *len, int cmd)
1811 {
1812 struct compat_ebt_replace repl, tmp;
1813 struct ebt_counter *oldcounters;
1814 struct ebt_table_info tinfo;
1815 int ret;
1816 void __user *pos;
1817
1818 memset(&tinfo, 0, sizeof(tinfo));
1819
1820 if (cmd == EBT_SO_GET_ENTRIES) {
1821 tinfo.entries_size = t->private->entries_size;
1822 tinfo.nentries = t->private->nentries;
1823 tinfo.entries = t->private->entries;
1824 oldcounters = t->private->counters;
1825 } else {
1826 tinfo.entries_size = t->table->entries_size;
1827 tinfo.nentries = t->table->nentries;
1828 tinfo.entries = t->table->entries;
1829 oldcounters = t->table->counters;
1830 }
1831
1832 if (copy_from_user(&tmp, user, sizeof(tmp)))
1833 return -EFAULT;
1834
1835 if (tmp.nentries != tinfo.nentries ||
1836 (tmp.num_counters && tmp.num_counters != tinfo.nentries))
1837 return -EINVAL;
1838
1839 memcpy(&repl, &tmp, sizeof(repl));
1840 if (cmd == EBT_SO_GET_ENTRIES)
1841 ret = compat_table_info(t->private, &repl);
1842 else
1843 ret = compat_table_info(&tinfo, &repl);
1844 if (ret)
1845 return ret;
1846
1847 if (*len != sizeof(tmp) + repl.entries_size +
1848 (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
1849 pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
1850 *len, tinfo.entries_size, repl.entries_size);
1851 return -EINVAL;
1852 }
1853
1854 /* userspace might not need the counters */
1855 ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters),
1856 tmp.num_counters, tinfo.nentries);
1857 if (ret)
1858 return ret;
1859
1860 pos = compat_ptr(tmp.entries);
1861 return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
1862 compat_copy_entry_to_user, &pos, &tmp.entries_size);
1863 }
1864
1865 struct ebt_entries_buf_state {
1866 char *buf_kern_start; /* kernel buffer to copy (translated) data to */
1867 u32 buf_kern_len; /* total size of kernel buffer */
1868 u32 buf_kern_offset; /* amount of data copied so far */
1869 u32 buf_user_offset; /* read position in userspace buffer */
1870 };
1871
1872 static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
1873 {
1874 state->buf_kern_offset += sz;
1875 return state->buf_kern_offset >= sz ? 0 : -EINVAL;
1876 }
1877
1878 static int ebt_buf_add(struct ebt_entries_buf_state *state,
1879 const void *data, unsigned int sz)
1880 {
1881 if (state->buf_kern_start == NULL)
1882 goto count_only;
1883
1884 if (WARN_ON(state->buf_kern_offset + sz > state->buf_kern_len))
1885 return -EINVAL;
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 if (WARN_ON(b && state->buf_kern_offset > state->buf_kern_len))
1899 return -EINVAL;
1900
1901 if (b != NULL && sz > 0)
1902 memset(b + state->buf_kern_offset, 0, sz);
1903 /* do not adjust ->buf_user_offset here, we added kernel-side padding */
1904 return ebt_buf_count(state, sz);
1905 }
1906
1907 enum compat_mwt {
1908 EBT_COMPAT_MATCH,
1909 EBT_COMPAT_WATCHER,
1910 EBT_COMPAT_TARGET,
1911 };
1912
1913 static int compat_mtw_from_user(const struct compat_ebt_entry_mwt *mwt,
1914 enum compat_mwt compat_mwt,
1915 struct ebt_entries_buf_state *state,
1916 const unsigned char *base)
1917 {
1918 char name[EBT_EXTENSION_MAXNAMELEN];
1919 struct xt_match *match;
1920 struct xt_target *wt;
1921 void *dst = NULL;
1922 int off, pad = 0;
1923 unsigned int size_kern, match_size = mwt->match_size;
1924
1925 if (strscpy(name, mwt->u.name, sizeof(name)) < 0)
1926 return -EINVAL;
1927
1928 if (state->buf_kern_start)
1929 dst = state->buf_kern_start + state->buf_kern_offset;
1930
1931 switch (compat_mwt) {
1932 case EBT_COMPAT_MATCH:
1933 match = xt_request_find_match(NFPROTO_BRIDGE, name,
1934 mwt->u.revision);
1935 if (IS_ERR(match))
1936 return PTR_ERR(match);
1937
1938 off = ebt_compat_match_offset(match, match_size);
1939 if (dst) {
1940 if (match->compat_from_user)
1941 match->compat_from_user(dst, mwt->data);
1942 else
1943 memcpy(dst, mwt->data, match_size);
1944 }
1945
1946 size_kern = match->matchsize;
1947 if (unlikely(size_kern == -1))
1948 size_kern = match_size;
1949 module_put(match->me);
1950 break;
1951 case EBT_COMPAT_WATCHER: /* fallthrough */
1952 case EBT_COMPAT_TARGET:
1953 wt = xt_request_find_target(NFPROTO_BRIDGE, name,
1954 mwt->u.revision);
1955 if (IS_ERR(wt))
1956 return PTR_ERR(wt);
1957 off = xt_compat_target_offset(wt);
1958
1959 if (dst) {
1960 if (wt->compat_from_user)
1961 wt->compat_from_user(dst, mwt->data);
1962 else
1963 memcpy(dst, mwt->data, match_size);
1964 }
1965
1966 size_kern = wt->targetsize;
1967 module_put(wt->me);
1968 break;
1969
1970 default:
1971 return -EINVAL;
1972 }
1973
1974 state->buf_kern_offset += match_size + off;
1975 state->buf_user_offset += match_size;
1976 pad = XT_ALIGN(size_kern) - size_kern;
1977
1978 if (pad > 0 && dst) {
1979 if (WARN_ON(state->buf_kern_len <= pad))
1980 return -EINVAL;
1981 if (WARN_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad))
1982 return -EINVAL;
1983 memset(dst + size_kern, 0, pad);
1984 }
1985 return off + match_size;
1986 }
1987
1988 /* return size of all matches, watchers or target, including necessary
1989 * alignment and padding.
1990 */
1991 static int ebt_size_mwt(const struct compat_ebt_entry_mwt *match32,
1992 unsigned int size_left, enum compat_mwt type,
1993 struct ebt_entries_buf_state *state, const void *base)
1994 {
1995 const char *buf = (const char *)match32;
1996 int growth = 0;
1997
1998 if (size_left == 0)
1999 return 0;
2000
2001 do {
2002 struct ebt_entry_match *match_kern;
2003 int ret;
2004
2005 if (size_left < sizeof(*match32))
2006 return -EINVAL;
2007
2008 match_kern = (struct ebt_entry_match *) state->buf_kern_start;
2009 if (match_kern) {
2010 char *tmp;
2011 tmp = state->buf_kern_start + state->buf_kern_offset;
2012 match_kern = (struct ebt_entry_match *) tmp;
2013 }
2014 ret = ebt_buf_add(state, buf, sizeof(*match32));
2015 if (ret < 0)
2016 return ret;
2017 size_left -= sizeof(*match32);
2018
2019 /* add padding before match->data (if any) */
2020 ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize());
2021 if (ret < 0)
2022 return ret;
2023
2024 if (match32->match_size > size_left)
2025 return -EINVAL;
2026
2027 size_left -= match32->match_size;
2028
2029 ret = compat_mtw_from_user(match32, type, state, base);
2030 if (ret < 0)
2031 return ret;
2032
2033 if (WARN_ON(ret < match32->match_size))
2034 return -EINVAL;
2035 growth += ret - match32->match_size;
2036 growth += ebt_compat_entry_padsize();
2037
2038 buf += sizeof(*match32);
2039 buf += match32->match_size;
2040
2041 if (match_kern)
2042 match_kern->match_size = ret;
2043
2044 match32 = (struct compat_ebt_entry_mwt *) buf;
2045 } while (size_left);
2046
2047 return growth;
2048 }
2049
2050 /* called for all ebt_entry structures. */
2051 static int size_entry_mwt(const struct ebt_entry *entry, const unsigned char *base,
2052 unsigned int *total,
2053 struct ebt_entries_buf_state *state)
2054 {
2055 unsigned int i, j, startoff, next_expected_off, new_offset = 0;
2056 /* stores match/watchers/targets & offset of next struct ebt_entry: */
2057 unsigned int offsets[4];
2058 unsigned int *offsets_update = NULL;
2059 int ret;
2060 char *buf_start;
2061
2062 if (*total < sizeof(struct ebt_entries))
2063 return -EINVAL;
2064
2065 if (!entry->bitmask) {
2066 *total -= sizeof(struct ebt_entries);
2067 return ebt_buf_add(state, entry, sizeof(struct ebt_entries));
2068 }
2069 if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
2070 return -EINVAL;
2071
2072 startoff = state->buf_user_offset;
2073 /* pull in most part of ebt_entry, it does not need to be changed. */
2074 ret = ebt_buf_add(state, entry,
2075 offsetof(struct ebt_entry, watchers_offset));
2076 if (ret < 0)
2077 return ret;
2078
2079 offsets[0] = sizeof(struct ebt_entry); /* matches come first */
2080 memcpy(&offsets[1], &entry->watchers_offset,
2081 sizeof(offsets) - sizeof(offsets[0]));
2082
2083 if (state->buf_kern_start) {
2084 buf_start = state->buf_kern_start + state->buf_kern_offset;
2085 offsets_update = (unsigned int *) buf_start;
2086 }
2087 ret = ebt_buf_add(state, &offsets[1],
2088 sizeof(offsets) - sizeof(offsets[0]));
2089 if (ret < 0)
2090 return ret;
2091 buf_start = (char *) entry;
2092 /* 0: matches offset, always follows ebt_entry.
2093 * 1: watchers offset, from ebt_entry structure
2094 * 2: target offset, from ebt_entry structure
2095 * 3: next ebt_entry offset, from ebt_entry structure
2096 *
2097 * offsets are relative to beginning of struct ebt_entry (i.e., 0).
2098 */
2099 for (i = 0; i < 4 ; ++i) {
2100 if (offsets[i] > *total)
2101 return -EINVAL;
2102
2103 if (i < 3 && offsets[i] == *total)
2104 return -EINVAL;
2105
2106 if (i == 0)
2107 continue;
2108 if (offsets[i-1] > offsets[i])
2109 return -EINVAL;
2110 }
2111
2112 for (i = 0, j = 1 ; j < 4 ; j++, i++) {
2113 struct compat_ebt_entry_mwt *match32;
2114 unsigned int size;
2115 char *buf = buf_start + offsets[i];
2116
2117 if (offsets[i] > offsets[j])
2118 return -EINVAL;
2119
2120 match32 = (struct compat_ebt_entry_mwt *) buf;
2121 size = offsets[j] - offsets[i];
2122 ret = ebt_size_mwt(match32, size, i, state, base);
2123 if (ret < 0)
2124 return ret;
2125 new_offset += ret;
2126 if (offsets_update && new_offset) {
2127 pr_debug("change offset %d to %d\n",
2128 offsets_update[i], offsets[j] + new_offset);
2129 offsets_update[i] = offsets[j] + new_offset;
2130 }
2131 }
2132
2133 if (state->buf_kern_start == NULL) {
2134 unsigned int offset = buf_start - (char *) base;
2135
2136 ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);
2137 if (ret < 0)
2138 return ret;
2139 }
2140
2141 next_expected_off = state->buf_user_offset - startoff;
2142 if (next_expected_off != entry->next_offset)
2143 return -EINVAL;
2144
2145 if (*total < entry->next_offset)
2146 return -EINVAL;
2147 *total -= entry->next_offset;
2148 return 0;
2149 }
2150
2151 /* repl->entries_size is the size of the ebt_entry blob in userspace.
2152 * It might need more memory when copied to a 64 bit kernel in case
2153 * userspace is 32-bit. So, first task: find out how much memory is needed.
2154 *
2155 * Called before validation is performed.
2156 */
2157 static int compat_copy_entries(unsigned char *data, unsigned int size_user,
2158 struct ebt_entries_buf_state *state)
2159 {
2160 unsigned int size_remaining = size_user;
2161 int ret;
2162
2163 ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
2164 &size_remaining, state);
2165 if (ret < 0)
2166 return ret;
2167
2168 if (size_remaining)
2169 return -EINVAL;
2170
2171 return state->buf_kern_offset;
2172 }
2173
2174
2175 static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
2176 void __user *user, unsigned int len)
2177 {
2178 struct compat_ebt_replace tmp;
2179 int i;
2180
2181 if (len < sizeof(tmp))
2182 return -EINVAL;
2183
2184 if (copy_from_user(&tmp, user, sizeof(tmp)))
2185 return -EFAULT;
2186
2187 if (len != sizeof(tmp) + tmp.entries_size)
2188 return -EINVAL;
2189
2190 if (tmp.entries_size == 0)
2191 return -EINVAL;
2192
2193 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
2194 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
2195 return -ENOMEM;
2196 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
2197 return -ENOMEM;
2198
2199 memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
2200
2201 /* starting with hook_entry, 32 vs. 64 bit structures are different */
2202 for (i = 0; i < NF_BR_NUMHOOKS; i++)
2203 repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]);
2204
2205 repl->num_counters = tmp.num_counters;
2206 repl->counters = compat_ptr(tmp.counters);
2207 repl->entries = compat_ptr(tmp.entries);
2208 return 0;
2209 }
2210
2211 static int compat_do_replace(struct net *net, void __user *user,
2212 unsigned int len)
2213 {
2214 int ret, i, countersize, size64;
2215 struct ebt_table_info *newinfo;
2216 struct ebt_replace tmp;
2217 struct ebt_entries_buf_state state;
2218 void *entries_tmp;
2219
2220 ret = compat_copy_ebt_replace_from_user(&tmp, user, len);
2221 if (ret) {
2222 /* try real handler in case userland supplied needed padding */
2223 if (ret == -EINVAL && do_replace(net, user, len) == 0)
2224 ret = 0;
2225 return ret;
2226 }
2227
2228 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
2229 newinfo = vmalloc(sizeof(*newinfo) + countersize);
2230 if (!newinfo)
2231 return -ENOMEM;
2232
2233 if (countersize)
2234 memset(newinfo->counters, 0, countersize);
2235
2236 memset(&state, 0, sizeof(state));
2237
2238 newinfo->entries = vmalloc(tmp.entries_size);
2239 if (!newinfo->entries) {
2240 ret = -ENOMEM;
2241 goto free_newinfo;
2242 }
2243 if (copy_from_user(
2244 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
2245 ret = -EFAULT;
2246 goto free_entries;
2247 }
2248
2249 entries_tmp = newinfo->entries;
2250
2251 xt_compat_lock(NFPROTO_BRIDGE);
2252
2253 ret = ebt_compat_init_offsets(tmp.nentries);
2254 if (ret < 0)
2255 goto out_unlock;
2256
2257 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2258 if (ret < 0)
2259 goto out_unlock;
2260
2261 pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
2262 tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
2263 xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
2264
2265 size64 = ret;
2266 newinfo->entries = vmalloc(size64);
2267 if (!newinfo->entries) {
2268 vfree(entries_tmp);
2269 ret = -ENOMEM;
2270 goto out_unlock;
2271 }
2272
2273 memset(&state, 0, sizeof(state));
2274 state.buf_kern_start = newinfo->entries;
2275 state.buf_kern_len = size64;
2276
2277 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2278 if (WARN_ON(ret < 0)) {
2279 vfree(entries_tmp);
2280 goto out_unlock;
2281 }
2282
2283 vfree(entries_tmp);
2284 tmp.entries_size = size64;
2285
2286 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
2287 char __user *usrptr;
2288 if (tmp.hook_entry[i]) {
2289 unsigned int delta;
2290 usrptr = (char __user *) tmp.hook_entry[i];
2291 delta = usrptr - tmp.entries;
2292 usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta);
2293 tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
2294 }
2295 }
2296
2297 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2298 xt_compat_unlock(NFPROTO_BRIDGE);
2299
2300 ret = do_replace_finish(net, &tmp, newinfo);
2301 if (ret == 0)
2302 return ret;
2303 free_entries:
2304 vfree(newinfo->entries);
2305 free_newinfo:
2306 vfree(newinfo);
2307 return ret;
2308 out_unlock:
2309 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2310 xt_compat_unlock(NFPROTO_BRIDGE);
2311 goto free_entries;
2312 }
2313
2314 static int compat_update_counters(struct net *net, void __user *user,
2315 unsigned int len)
2316 {
2317 struct compat_ebt_replace hlp;
2318
2319 if (copy_from_user(&hlp, user, sizeof(hlp)))
2320 return -EFAULT;
2321
2322 /* try real handler in case userland supplied needed padding */
2323 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
2324 return update_counters(net, user, len);
2325
2326 return do_update_counters(net, hlp.name, compat_ptr(hlp.counters),
2327 hlp.num_counters, user, len);
2328 }
2329
2330 static int compat_do_ebt_set_ctl(struct sock *sk,
2331 int cmd, void __user *user, unsigned int len)
2332 {
2333 int ret;
2334 struct net *net = sock_net(sk);
2335
2336 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2337 return -EPERM;
2338
2339 switch (cmd) {
2340 case EBT_SO_SET_ENTRIES:
2341 ret = compat_do_replace(net, user, len);
2342 break;
2343 case EBT_SO_SET_COUNTERS:
2344 ret = compat_update_counters(net, user, len);
2345 break;
2346 default:
2347 ret = -EINVAL;
2348 }
2349 return ret;
2350 }
2351
2352 static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
2353 void __user *user, int *len)
2354 {
2355 int ret;
2356 struct compat_ebt_replace tmp;
2357 struct ebt_table *t;
2358 struct net *net = sock_net(sk);
2359
2360 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2361 return -EPERM;
2362
2363 /* try real handler in case userland supplied needed padding */
2364 if ((cmd == EBT_SO_GET_INFO ||
2365 cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp))
2366 return do_ebt_get_ctl(sk, cmd, user, len);
2367
2368 if (copy_from_user(&tmp, user, sizeof(tmp)))
2369 return -EFAULT;
2370
2371 tmp.name[sizeof(tmp.name) - 1] = '\0';
2372
2373 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
2374 if (!t)
2375 return ret;
2376
2377 xt_compat_lock(NFPROTO_BRIDGE);
2378 switch (cmd) {
2379 case EBT_SO_GET_INFO:
2380 tmp.nentries = t->private->nentries;
2381 ret = compat_table_info(t->private, &tmp);
2382 if (ret)
2383 goto out;
2384 tmp.valid_hooks = t->valid_hooks;
2385
2386 if (copy_to_user(user, &tmp, *len) != 0) {
2387 ret = -EFAULT;
2388 break;
2389 }
2390 ret = 0;
2391 break;
2392 case EBT_SO_GET_INIT_INFO:
2393 tmp.nentries = t->table->nentries;
2394 tmp.entries_size = t->table->entries_size;
2395 tmp.valid_hooks = t->table->valid_hooks;
2396
2397 if (copy_to_user(user, &tmp, *len) != 0) {
2398 ret = -EFAULT;
2399 break;
2400 }
2401 ret = 0;
2402 break;
2403 case EBT_SO_GET_ENTRIES:
2404 case EBT_SO_GET_INIT_ENTRIES:
2405 /* try real handler first in case of userland-side padding.
2406 * in case we are dealing with an 'ordinary' 32 bit binary
2407 * without 64bit compatibility padding, this will fail right
2408 * after copy_from_user when the *len argument is validated.
2409 *
2410 * the compat_ variant needs to do one pass over the kernel
2411 * data set to adjust for size differences before it the check.
2412 */
2413 if (copy_everything_to_user(t, user, len, cmd) == 0)
2414 ret = 0;
2415 else
2416 ret = compat_copy_everything_to_user(t, user, len, cmd);
2417 break;
2418 default:
2419 ret = -EINVAL;
2420 }
2421 out:
2422 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2423 xt_compat_unlock(NFPROTO_BRIDGE);
2424 mutex_unlock(&ebt_mutex);
2425 return ret;
2426 }
2427 #endif
2428
2429 static struct nf_sockopt_ops ebt_sockopts = {
2430 .pf = PF_INET,
2431 .set_optmin = EBT_BASE_CTL,
2432 .set_optmax = EBT_SO_SET_MAX + 1,
2433 .set = do_ebt_set_ctl,
2434 #ifdef CONFIG_COMPAT
2435 .compat_set = compat_do_ebt_set_ctl,
2436 #endif
2437 .get_optmin = EBT_BASE_CTL,
2438 .get_optmax = EBT_SO_GET_MAX + 1,
2439 .get = do_ebt_get_ctl,
2440 #ifdef CONFIG_COMPAT
2441 .compat_get = compat_do_ebt_get_ctl,
2442 #endif
2443 .owner = THIS_MODULE,
2444 };
2445
2446 static int __init ebtables_init(void)
2447 {
2448 int ret;
2449
2450 ret = xt_register_target(&ebt_standard_target);
2451 if (ret < 0)
2452 return ret;
2453 ret = nf_register_sockopt(&ebt_sockopts);
2454 if (ret < 0) {
2455 xt_unregister_target(&ebt_standard_target);
2456 return ret;
2457 }
2458
2459 return 0;
2460 }
2461
2462 static void __exit ebtables_fini(void)
2463 {
2464 nf_unregister_sockopt(&ebt_sockopts);
2465 xt_unregister_target(&ebt_standard_target);
2466 }
2467
2468 EXPORT_SYMBOL(ebt_register_table);
2469 EXPORT_SYMBOL(ebt_unregister_table);
2470 EXPORT_SYMBOL(ebt_do_table);
2471 module_init(ebtables_init);
2472 module_exit(ebtables_fini);
2473 MODULE_LICENSE("GPL");
Linux with added FPC-III support