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Merge tag 'linux-watchdog-4.17-rc1' of git://www.linux-watchdog.org/linux-watchdog
[mirror_ubuntu-focal-kernel.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 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 #define BUGPRINT(format, args...) printk("kernel msg: ebtables bug: please "\
35 "report to author: "format, ## args)
36 /* #define BUGPRINT(format, args...) */
37
38 /* Each cpu has its own set of counters, so there is no need for write_lock in
39 * the softirq
40 * For reading or updating the counters, the user context needs to
41 * get a write_lock
42 */
43
44 /* The size of each set of counters is altered to get cache alignment */
45 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
46 #define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter)))
47 #define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \
48 COUNTER_OFFSET(n) * cpu))
49
50
51
52 static DEFINE_MUTEX(ebt_mutex);
53
54 #ifdef CONFIG_COMPAT
55 static void ebt_standard_compat_from_user(void *dst, const void *src)
56 {
57 int v = *(compat_int_t *)src;
58
59 if (v >= 0)
60 v += xt_compat_calc_jump(NFPROTO_BRIDGE, v);
61 memcpy(dst, &v, sizeof(v));
62 }
63
64 static int ebt_standard_compat_to_user(void __user *dst, const void *src)
65 {
66 compat_int_t cv = *(int *)src;
67
68 if (cv >= 0)
69 cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv);
70 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
71 }
72 #endif
73
74
75 static struct xt_target ebt_standard_target = {
76 .name = "standard",
77 .revision = 0,
78 .family = NFPROTO_BRIDGE,
79 .targetsize = sizeof(int),
80 #ifdef CONFIG_COMPAT
81 .compatsize = sizeof(compat_int_t),
82 .compat_from_user = ebt_standard_compat_from_user,
83 .compat_to_user = ebt_standard_compat_to_user,
84 #endif
85 };
86
87 static inline int
88 ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb,
89 struct xt_action_param *par)
90 {
91 par->target = w->u.watcher;
92 par->targinfo = w->data;
93 w->u.watcher->target(skb, par);
94 /* watchers don't give a verdict */
95 return 0;
96 }
97
98 static inline int
99 ebt_do_match(struct ebt_entry_match *m, const struct sk_buff *skb,
100 struct xt_action_param *par)
101 {
102 par->match = m->u.match;
103 par->matchinfo = m->data;
104 return m->u.match->match(skb, par) ? EBT_MATCH : EBT_NOMATCH;
105 }
106
107 static inline int
108 ebt_dev_check(const char *entry, const struct net_device *device)
109 {
110 int i = 0;
111 const char *devname;
112
113 if (*entry == '\0')
114 return 0;
115 if (!device)
116 return 1;
117 devname = device->name;
118 /* 1 is the wildcard token */
119 while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i])
120 i++;
121 return devname[i] != entry[i] && entry[i] != 1;
122 }
123
124 /* process standard matches */
125 static inline int
126 ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb,
127 const struct net_device *in, const struct net_device *out)
128 {
129 const struct ethhdr *h = eth_hdr(skb);
130 const struct net_bridge_port *p;
131 __be16 ethproto;
132
133 if (skb_vlan_tag_present(skb))
134 ethproto = htons(ETH_P_8021Q);
135 else
136 ethproto = h->h_proto;
137
138 if (e->bitmask & EBT_802_3) {
139 if (NF_INVF(e, EBT_IPROTO, eth_proto_is_802_3(ethproto)))
140 return 1;
141 } else if (!(e->bitmask & EBT_NOPROTO) &&
142 NF_INVF(e, EBT_IPROTO, e->ethproto != ethproto))
143 return 1;
144
145 if (NF_INVF(e, EBT_IIN, ebt_dev_check(e->in, in)))
146 return 1;
147 if (NF_INVF(e, EBT_IOUT, ebt_dev_check(e->out, out)))
148 return 1;
149 /* rcu_read_lock()ed by nf_hook_thresh */
150 if (in && (p = br_port_get_rcu(in)) != NULL &&
151 NF_INVF(e, EBT_ILOGICALIN,
152 ebt_dev_check(e->logical_in, p->br->dev)))
153 return 1;
154 if (out && (p = br_port_get_rcu(out)) != NULL &&
155 NF_INVF(e, EBT_ILOGICALOUT,
156 ebt_dev_check(e->logical_out, p->br->dev)))
157 return 1;
158
159 if (e->bitmask & EBT_SOURCEMAC) {
160 if (NF_INVF(e, EBT_ISOURCE,
161 !ether_addr_equal_masked(h->h_source, e->sourcemac,
162 e->sourcemsk)))
163 return 1;
164 }
165 if (e->bitmask & EBT_DESTMAC) {
166 if (NF_INVF(e, EBT_IDEST,
167 !ether_addr_equal_masked(h->h_dest, e->destmac,
168 e->destmsk)))
169 return 1;
170 }
171 return 0;
172 }
173
174 static inline
175 struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry)
176 {
177 return (void *)entry + entry->next_offset;
178 }
179
180 /* Do some firewalling */
181 unsigned int ebt_do_table(struct sk_buff *skb,
182 const struct nf_hook_state *state,
183 struct ebt_table *table)
184 {
185 unsigned int hook = state->hook;
186 int i, nentries;
187 struct ebt_entry *point;
188 struct ebt_counter *counter_base, *cb_base;
189 const struct ebt_entry_target *t;
190 int verdict, sp = 0;
191 struct ebt_chainstack *cs;
192 struct ebt_entries *chaininfo;
193 const char *base;
194 const struct ebt_table_info *private;
195 struct xt_action_param acpar;
196
197 acpar.state = state;
198 acpar.hotdrop = false;
199
200 read_lock_bh(&table->lock);
201 private = table->private;
202 cb_base = COUNTER_BASE(private->counters, private->nentries,
203 smp_processor_id());
204 if (private->chainstack)
205 cs = private->chainstack[smp_processor_id()];
206 else
207 cs = NULL;
208 chaininfo = private->hook_entry[hook];
209 nentries = private->hook_entry[hook]->nentries;
210 point = (struct ebt_entry *)(private->hook_entry[hook]->data);
211 counter_base = cb_base + private->hook_entry[hook]->counter_offset;
212 /* base for chain jumps */
213 base = private->entries;
214 i = 0;
215 while (i < nentries) {
216 if (ebt_basic_match(point, skb, state->in, state->out))
217 goto letscontinue;
218
219 if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0)
220 goto letscontinue;
221 if (acpar.hotdrop) {
222 read_unlock_bh(&table->lock);
223 return NF_DROP;
224 }
225
226 ADD_COUNTER(*(counter_base + i), 1, skb->len);
227
228 /* these should only watch: not modify, nor tell us
229 * what to do with the packet
230 */
231 EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar);
232
233 t = (struct ebt_entry_target *)
234 (((char *)point) + point->target_offset);
235 /* standard target */
236 if (!t->u.target->target)
237 verdict = ((struct ebt_standard_target *)t)->verdict;
238 else {
239 acpar.target = t->u.target;
240 acpar.targinfo = t->data;
241 verdict = t->u.target->target(skb, &acpar);
242 }
243 if (verdict == EBT_ACCEPT) {
244 read_unlock_bh(&table->lock);
245 return NF_ACCEPT;
246 }
247 if (verdict == EBT_DROP) {
248 read_unlock_bh(&table->lock);
249 return NF_DROP;
250 }
251 if (verdict == EBT_RETURN) {
252 letsreturn:
253 if (WARN(sp == 0, "RETURN on base chain")) {
254 /* act like this is EBT_CONTINUE */
255 goto letscontinue;
256 }
257
258 sp--;
259 /* put all the local variables right */
260 i = cs[sp].n;
261 chaininfo = cs[sp].chaininfo;
262 nentries = chaininfo->nentries;
263 point = cs[sp].e;
264 counter_base = cb_base +
265 chaininfo->counter_offset;
266 continue;
267 }
268 if (verdict == EBT_CONTINUE)
269 goto letscontinue;
270
271 if (WARN(verdict < 0, "bogus standard verdict\n")) {
272 read_unlock_bh(&table->lock);
273 return NF_DROP;
274 }
275
276 /* jump to a udc */
277 cs[sp].n = i + 1;
278 cs[sp].chaininfo = chaininfo;
279 cs[sp].e = ebt_next_entry(point);
280 i = 0;
281 chaininfo = (struct ebt_entries *) (base + verdict);
282
283 if (WARN(chaininfo->distinguisher, "jump to non-chain\n")) {
284 read_unlock_bh(&table->lock);
285 return NF_DROP;
286 }
287
288 nentries = chaininfo->nentries;
289 point = (struct ebt_entry *)chaininfo->data;
290 counter_base = cb_base + chaininfo->counter_offset;
291 sp++;
292 continue;
293 letscontinue:
294 point = ebt_next_entry(point);
295 i++;
296 }
297
298 /* I actually like this :) */
299 if (chaininfo->policy == EBT_RETURN)
300 goto letsreturn;
301 if (chaininfo->policy == EBT_ACCEPT) {
302 read_unlock_bh(&table->lock);
303 return NF_ACCEPT;
304 }
305 read_unlock_bh(&table->lock);
306 return NF_DROP;
307 }
308
309 /* If it succeeds, returns element and locks mutex */
310 static inline void *
311 find_inlist_lock_noload(struct list_head *head, const char *name, int *error,
312 struct mutex *mutex)
313 {
314 struct {
315 struct list_head list;
316 char name[EBT_FUNCTION_MAXNAMELEN];
317 } *e;
318
319 mutex_lock(mutex);
320 list_for_each_entry(e, head, list) {
321 if (strcmp(e->name, name) == 0)
322 return e;
323 }
324 *error = -ENOENT;
325 mutex_unlock(mutex);
326 return NULL;
327 }
328
329 static void *
330 find_inlist_lock(struct list_head *head, const char *name, const char *prefix,
331 int *error, struct mutex *mutex)
332 {
333 return try_then_request_module(
334 find_inlist_lock_noload(head, name, error, mutex),
335 "%s%s", prefix, name);
336 }
337
338 static inline struct ebt_table *
339 find_table_lock(struct net *net, const char *name, int *error,
340 struct mutex *mutex)
341 {
342 return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name,
343 "ebtable_", error, mutex);
344 }
345
346 static inline int
347 ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
348 unsigned int *cnt)
349 {
350 const struct ebt_entry *e = par->entryinfo;
351 struct xt_match *match;
352 size_t left = ((char *)e + e->watchers_offset) - (char *)m;
353 int ret;
354
355 if (left < sizeof(struct ebt_entry_match) ||
356 left - sizeof(struct ebt_entry_match) < m->match_size)
357 return -EINVAL;
358
359 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision);
360 if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) {
361 if (!IS_ERR(match))
362 module_put(match->me);
363 request_module("ebt_%s", m->u.name);
364 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision);
365 }
366 if (IS_ERR(match))
367 return PTR_ERR(match);
368 m->u.match = match;
369
370 par->match = match;
371 par->matchinfo = m->data;
372 ret = xt_check_match(par, m->match_size,
373 e->ethproto, e->invflags & EBT_IPROTO);
374 if (ret < 0) {
375 module_put(match->me);
376 return ret;
377 }
378
379 (*cnt)++;
380 return 0;
381 }
382
383 static inline int
384 ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
385 unsigned int *cnt)
386 {
387 const struct ebt_entry *e = par->entryinfo;
388 struct xt_target *watcher;
389 size_t left = ((char *)e + e->target_offset) - (char *)w;
390 int ret;
391
392 if (left < sizeof(struct ebt_entry_watcher) ||
393 left - sizeof(struct ebt_entry_watcher) < w->watcher_size)
394 return -EINVAL;
395
396 watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0);
397 if (IS_ERR(watcher))
398 return PTR_ERR(watcher);
399 w->u.watcher = watcher;
400
401 par->target = watcher;
402 par->targinfo = w->data;
403 ret = xt_check_target(par, w->watcher_size,
404 e->ethproto, e->invflags & EBT_IPROTO);
405 if (ret < 0) {
406 module_put(watcher->me);
407 return ret;
408 }
409
410 (*cnt)++;
411 return 0;
412 }
413
414 static int ebt_verify_pointers(const struct ebt_replace *repl,
415 struct ebt_table_info *newinfo)
416 {
417 unsigned int limit = repl->entries_size;
418 unsigned int valid_hooks = repl->valid_hooks;
419 unsigned int offset = 0;
420 int i;
421
422 for (i = 0; i < NF_BR_NUMHOOKS; i++)
423 newinfo->hook_entry[i] = NULL;
424
425 newinfo->entries_size = repl->entries_size;
426 newinfo->nentries = repl->nentries;
427
428 while (offset < limit) {
429 size_t left = limit - offset;
430 struct ebt_entry *e = (void *)newinfo->entries + offset;
431
432 if (left < sizeof(unsigned int))
433 break;
434
435 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
436 if ((valid_hooks & (1 << i)) == 0)
437 continue;
438 if ((char __user *)repl->hook_entry[i] ==
439 repl->entries + offset)
440 break;
441 }
442
443 if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
444 if (e->bitmask != 0) {
445 /* we make userspace set this right,
446 * so there is no misunderstanding
447 */
448 BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set "
449 "in distinguisher\n");
450 return -EINVAL;
451 }
452 if (i != NF_BR_NUMHOOKS)
453 newinfo->hook_entry[i] = (struct ebt_entries *)e;
454 if (left < sizeof(struct ebt_entries))
455 break;
456 offset += sizeof(struct ebt_entries);
457 } else {
458 if (left < sizeof(struct ebt_entry))
459 break;
460 if (left < e->next_offset)
461 break;
462 if (e->next_offset < sizeof(struct ebt_entry))
463 return -EINVAL;
464 offset += e->next_offset;
465 }
466 }
467 if (offset != limit) {
468 BUGPRINT("entries_size too small\n");
469 return -EINVAL;
470 }
471
472 /* check if all valid hooks have a chain */
473 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
474 if (!newinfo->hook_entry[i] &&
475 (valid_hooks & (1 << i))) {
476 BUGPRINT("Valid hook without chain\n");
477 return -EINVAL;
478 }
479 }
480 return 0;
481 }
482
483 /* this one is very careful, as it is the first function
484 * to parse the userspace data
485 */
486 static inline int
487 ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
488 const struct ebt_table_info *newinfo,
489 unsigned int *n, unsigned int *cnt,
490 unsigned int *totalcnt, unsigned int *udc_cnt)
491 {
492 int i;
493
494 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
495 if ((void *)e == (void *)newinfo->hook_entry[i])
496 break;
497 }
498 /* beginning of a new chain
499 * if i == NF_BR_NUMHOOKS it must be a user defined chain
500 */
501 if (i != NF_BR_NUMHOOKS || !e->bitmask) {
502 /* this checks if the previous chain has as many entries
503 * as it said it has
504 */
505 if (*n != *cnt) {
506 BUGPRINT("nentries does not equal the nr of entries "
507 "in the chain\n");
508 return -EINVAL;
509 }
510 if (((struct ebt_entries *)e)->policy != EBT_DROP &&
511 ((struct ebt_entries *)e)->policy != EBT_ACCEPT) {
512 /* only RETURN from udc */
513 if (i != NF_BR_NUMHOOKS ||
514 ((struct ebt_entries *)e)->policy != EBT_RETURN) {
515 BUGPRINT("bad policy\n");
516 return -EINVAL;
517 }
518 }
519 if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */
520 (*udc_cnt)++;
521 if (((struct ebt_entries *)e)->counter_offset != *totalcnt) {
522 BUGPRINT("counter_offset != totalcnt");
523 return -EINVAL;
524 }
525 *n = ((struct ebt_entries *)e)->nentries;
526 *cnt = 0;
527 return 0;
528 }
529 /* a plain old entry, heh */
530 if (sizeof(struct ebt_entry) > e->watchers_offset ||
531 e->watchers_offset > e->target_offset ||
532 e->target_offset >= e->next_offset) {
533 BUGPRINT("entry offsets not in right order\n");
534 return -EINVAL;
535 }
536 /* this is not checked anywhere else */
537 if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target)) {
538 BUGPRINT("target size too small\n");
539 return -EINVAL;
540 }
541 (*cnt)++;
542 (*totalcnt)++;
543 return 0;
544 }
545
546 struct ebt_cl_stack {
547 struct ebt_chainstack cs;
548 int from;
549 unsigned int hookmask;
550 };
551
552 /* We need these positions to check that the jumps to a different part of the
553 * entries is a jump to the beginning of a new chain.
554 */
555 static inline int
556 ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo,
557 unsigned int *n, struct ebt_cl_stack *udc)
558 {
559 int i;
560
561 /* we're only interested in chain starts */
562 if (e->bitmask)
563 return 0;
564 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
565 if (newinfo->hook_entry[i] == (struct ebt_entries *)e)
566 break;
567 }
568 /* only care about udc */
569 if (i != NF_BR_NUMHOOKS)
570 return 0;
571
572 udc[*n].cs.chaininfo = (struct ebt_entries *)e;
573 /* these initialisations are depended on later in check_chainloops() */
574 udc[*n].cs.n = 0;
575 udc[*n].hookmask = 0;
576
577 (*n)++;
578 return 0;
579 }
580
581 static inline int
582 ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i)
583 {
584 struct xt_mtdtor_param par;
585
586 if (i && (*i)-- == 0)
587 return 1;
588
589 par.net = net;
590 par.match = m->u.match;
591 par.matchinfo = m->data;
592 par.family = NFPROTO_BRIDGE;
593 if (par.match->destroy != NULL)
594 par.match->destroy(&par);
595 module_put(par.match->me);
596 return 0;
597 }
598
599 static inline int
600 ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i)
601 {
602 struct xt_tgdtor_param par;
603
604 if (i && (*i)-- == 0)
605 return 1;
606
607 par.net = net;
608 par.target = w->u.watcher;
609 par.targinfo = w->data;
610 par.family = NFPROTO_BRIDGE;
611 if (par.target->destroy != NULL)
612 par.target->destroy(&par);
613 module_put(par.target->me);
614 return 0;
615 }
616
617 static inline int
618 ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
619 {
620 struct xt_tgdtor_param par;
621 struct ebt_entry_target *t;
622
623 if (e->bitmask == 0)
624 return 0;
625 /* we're done */
626 if (cnt && (*cnt)-- == 0)
627 return 1;
628 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL);
629 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL);
630 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
631
632 par.net = net;
633 par.target = t->u.target;
634 par.targinfo = t->data;
635 par.family = NFPROTO_BRIDGE;
636 if (par.target->destroy != NULL)
637 par.target->destroy(&par);
638 module_put(par.target->me);
639 return 0;
640 }
641
642 static inline int
643 ebt_check_entry(struct ebt_entry *e, struct net *net,
644 const struct ebt_table_info *newinfo,
645 const char *name, unsigned int *cnt,
646 struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
647 {
648 struct ebt_entry_target *t;
649 struct xt_target *target;
650 unsigned int i, j, hook = 0, hookmask = 0;
651 size_t gap;
652 int ret;
653 struct xt_mtchk_param mtpar;
654 struct xt_tgchk_param tgpar;
655
656 /* don't mess with the struct ebt_entries */
657 if (e->bitmask == 0)
658 return 0;
659
660 if (e->bitmask & ~EBT_F_MASK) {
661 BUGPRINT("Unknown flag for bitmask\n");
662 return -EINVAL;
663 }
664 if (e->invflags & ~EBT_INV_MASK) {
665 BUGPRINT("Unknown flag for inv bitmask\n");
666 return -EINVAL;
667 }
668 if ((e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3)) {
669 BUGPRINT("NOPROTO & 802_3 not allowed\n");
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 mtpar.net = tgpar.net = net;
698 mtpar.table = tgpar.table = name;
699 mtpar.entryinfo = tgpar.entryinfo = e;
700 mtpar.hook_mask = tgpar.hook_mask = hookmask;
701 mtpar.family = tgpar.family = NFPROTO_BRIDGE;
702 ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i);
703 if (ret != 0)
704 goto cleanup_matches;
705 j = 0;
706 ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j);
707 if (ret != 0)
708 goto cleanup_watchers;
709 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
710 gap = e->next_offset - e->target_offset;
711
712 target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0);
713 if (IS_ERR(target)) {
714 ret = PTR_ERR(target);
715 goto cleanup_watchers;
716 }
717
718 t->u.target = target;
719 if (t->u.target == &ebt_standard_target) {
720 if (gap < sizeof(struct ebt_standard_target)) {
721 BUGPRINT("Standard target size too big\n");
722 ret = -EFAULT;
723 goto cleanup_watchers;
724 }
725 if (((struct ebt_standard_target *)t)->verdict <
726 -NUM_STANDARD_TARGETS) {
727 BUGPRINT("Invalid standard target\n");
728 ret = -EFAULT;
729 goto cleanup_watchers;
730 }
731 } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) {
732 module_put(t->u.target->me);
733 ret = -EFAULT;
734 goto cleanup_watchers;
735 }
736
737 tgpar.target = target;
738 tgpar.targinfo = t->data;
739 ret = xt_check_target(&tgpar, t->target_size,
740 e->ethproto, e->invflags & EBT_IPROTO);
741 if (ret < 0) {
742 module_put(target->me);
743 goto cleanup_watchers;
744 }
745 (*cnt)++;
746 return 0;
747 cleanup_watchers:
748 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j);
749 cleanup_matches:
750 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i);
751 return ret;
752 }
753
754 /* checks for loops and sets the hook mask for udc
755 * the hook mask for udc tells us from which base chains the udc can be
756 * accessed. This mask is a parameter to the check() functions of the extensions
757 */
758 static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
759 unsigned int udc_cnt, unsigned int hooknr, char *base)
760 {
761 int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
762 const struct ebt_entry *e = (struct ebt_entry *)chain->data;
763 const struct ebt_entry_target *t;
764
765 while (pos < nentries || chain_nr != -1) {
766 /* end of udc, go back one 'recursion' step */
767 if (pos == nentries) {
768 /* put back values of the time when this chain was called */
769 e = cl_s[chain_nr].cs.e;
770 if (cl_s[chain_nr].from != -1)
771 nentries =
772 cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries;
773 else
774 nentries = chain->nentries;
775 pos = cl_s[chain_nr].cs.n;
776 /* make sure we won't see a loop that isn't one */
777 cl_s[chain_nr].cs.n = 0;
778 chain_nr = cl_s[chain_nr].from;
779 if (pos == nentries)
780 continue;
781 }
782 t = (struct ebt_entry_target *)
783 (((char *)e) + e->target_offset);
784 if (strcmp(t->u.name, EBT_STANDARD_TARGET))
785 goto letscontinue;
786 if (e->target_offset + sizeof(struct ebt_standard_target) >
787 e->next_offset) {
788 BUGPRINT("Standard target size too big\n");
789 return -1;
790 }
791 verdict = ((struct ebt_standard_target *)t)->verdict;
792 if (verdict >= 0) { /* jump to another chain */
793 struct ebt_entries *hlp2 =
794 (struct ebt_entries *)(base + verdict);
795 for (i = 0; i < udc_cnt; i++)
796 if (hlp2 == cl_s[i].cs.chaininfo)
797 break;
798 /* bad destination or loop */
799 if (i == udc_cnt) {
800 BUGPRINT("bad destination\n");
801 return -1;
802 }
803 if (cl_s[i].cs.n) {
804 BUGPRINT("loop\n");
805 return -1;
806 }
807 if (cl_s[i].hookmask & (1 << hooknr))
808 goto letscontinue;
809 /* this can't be 0, so the loop test is correct */
810 cl_s[i].cs.n = pos + 1;
811 pos = 0;
812 cl_s[i].cs.e = ebt_next_entry(e);
813 e = (struct ebt_entry *)(hlp2->data);
814 nentries = hlp2->nentries;
815 cl_s[i].from = chain_nr;
816 chain_nr = i;
817 /* this udc is accessible from the base chain for hooknr */
818 cl_s[i].hookmask |= (1 << hooknr);
819 continue;
820 }
821 letscontinue:
822 e = ebt_next_entry(e);
823 pos++;
824 }
825 return 0;
826 }
827
828 /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
829 static int translate_table(struct net *net, const char *name,
830 struct ebt_table_info *newinfo)
831 {
832 unsigned int i, j, k, udc_cnt;
833 int ret;
834 struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */
835
836 i = 0;
837 while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i])
838 i++;
839 if (i == NF_BR_NUMHOOKS) {
840 BUGPRINT("No valid hooks specified\n");
841 return -EINVAL;
842 }
843 if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) {
844 BUGPRINT("Chains don't start at beginning\n");
845 return -EINVAL;
846 }
847 /* make sure chains are ordered after each other in same order
848 * as their corresponding hooks
849 */
850 for (j = i + 1; j < NF_BR_NUMHOOKS; j++) {
851 if (!newinfo->hook_entry[j])
852 continue;
853 if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) {
854 BUGPRINT("Hook order must be followed\n");
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 BUGPRINT("nentries does not equal the nr of entries in the "
876 "(last) chain\n");
877 return -EINVAL;
878 }
879 if (k != newinfo->nentries) {
880 BUGPRINT("Total nentries is wrong\n");
881 return -EINVAL;
882 }
883
884 /* get the location of the udc, put them in an array
885 * while we're at it, allocate the chainstack
886 */
887 if (udc_cnt) {
888 /* this will get free'd in do_replace()/ebt_register_table()
889 * if an error occurs
890 */
891 newinfo->chainstack =
892 vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack)));
893 if (!newinfo->chainstack)
894 return -ENOMEM;
895 for_each_possible_cpu(i) {
896 newinfo->chainstack[i] =
897 vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0])));
898 if (!newinfo->chainstack[i]) {
899 while (i)
900 vfree(newinfo->chainstack[--i]);
901 vfree(newinfo->chainstack);
902 newinfo->chainstack = NULL;
903 return -ENOMEM;
904 }
905 }
906
907 cl_s = vmalloc(udc_cnt * sizeof(*cl_s));
908 if (!cl_s)
909 return -ENOMEM;
910 i = 0; /* the i'th udc */
911 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
912 ebt_get_udc_positions, newinfo, &i, cl_s);
913 /* sanity check */
914 if (i != udc_cnt) {
915 BUGPRINT("i != udc_cnt\n");
916 vfree(cl_s);
917 return -EFAULT;
918 }
919 }
920
921 /* Check for loops */
922 for (i = 0; i < NF_BR_NUMHOOKS; i++)
923 if (newinfo->hook_entry[i])
924 if (check_chainloops(newinfo->hook_entry[i],
925 cl_s, udc_cnt, i, newinfo->entries)) {
926 vfree(cl_s);
927 return -EINVAL;
928 }
929
930 /* we now know the following (along with E=mc²):
931 * - the nr of entries in each chain is right
932 * - the size of the allocated space is right
933 * - all valid hooks have a corresponding chain
934 * - there are no loops
935 * - wrong data can still be on the level of a single entry
936 * - could be there are jumps to places that are not the
937 * beginning of a chain. This can only occur in chains that
938 * are not accessible from any base chains, so we don't care.
939 */
940
941 /* used to know what we need to clean up if something goes wrong */
942 i = 0;
943 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
944 ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt);
945 if (ret != 0) {
946 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
947 ebt_cleanup_entry, net, &i);
948 }
949 vfree(cl_s);
950 return ret;
951 }
952
953 /* called under write_lock */
954 static void get_counters(const struct ebt_counter *oldcounters,
955 struct ebt_counter *counters, unsigned int nentries)
956 {
957 int i, cpu;
958 struct ebt_counter *counter_base;
959
960 /* counters of cpu 0 */
961 memcpy(counters, oldcounters,
962 sizeof(struct ebt_counter) * nentries);
963
964 /* add other counters to those of cpu 0 */
965 for_each_possible_cpu(cpu) {
966 if (cpu == 0)
967 continue;
968 counter_base = COUNTER_BASE(oldcounters, nentries, cpu);
969 for (i = 0; i < nentries; i++)
970 ADD_COUNTER(counters[i], counter_base[i].pcnt,
971 counter_base[i].bcnt);
972 }
973 }
974
975 static int do_replace_finish(struct net *net, struct ebt_replace *repl,
976 struct ebt_table_info *newinfo)
977 {
978 int ret, i;
979 struct ebt_counter *counterstmp = NULL;
980 /* used to be able to unlock earlier */
981 struct ebt_table_info *table;
982 struct ebt_table *t;
983
984 /* the user wants counters back
985 * the check on the size is done later, when we have the lock
986 */
987 if (repl->num_counters) {
988 unsigned long size = repl->num_counters * sizeof(*counterstmp);
989 counterstmp = vmalloc(size);
990 if (!counterstmp)
991 return -ENOMEM;
992 }
993
994 newinfo->chainstack = NULL;
995 ret = ebt_verify_pointers(repl, newinfo);
996 if (ret != 0)
997 goto free_counterstmp;
998
999 ret = translate_table(net, repl->name, newinfo);
1000
1001 if (ret != 0)
1002 goto free_counterstmp;
1003
1004 t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
1005 if (!t) {
1006 ret = -ENOENT;
1007 goto free_iterate;
1008 }
1009
1010 /* the table doesn't like it */
1011 if (t->check && (ret = t->check(newinfo, repl->valid_hooks)))
1012 goto free_unlock;
1013
1014 if (repl->num_counters && repl->num_counters != t->private->nentries) {
1015 BUGPRINT("Wrong nr. of counters requested\n");
1016 ret = -EINVAL;
1017 goto free_unlock;
1018 }
1019
1020 /* we have the mutex lock, so no danger in reading this pointer */
1021 table = t->private;
1022 /* make sure the table can only be rmmod'ed if it contains no rules */
1023 if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) {
1024 ret = -ENOENT;
1025 goto free_unlock;
1026 } else if (table->nentries && !newinfo->nentries)
1027 module_put(t->me);
1028 /* we need an atomic snapshot of the counters */
1029 write_lock_bh(&t->lock);
1030 if (repl->num_counters)
1031 get_counters(t->private->counters, counterstmp,
1032 t->private->nentries);
1033
1034 t->private = newinfo;
1035 write_unlock_bh(&t->lock);
1036 mutex_unlock(&ebt_mutex);
1037 /* so, a user can change the chains while having messed up her counter
1038 * allocation. Only reason why this is done is because this way the lock
1039 * is held only once, while this doesn't bring the kernel into a
1040 * dangerous state.
1041 */
1042 if (repl->num_counters &&
1043 copy_to_user(repl->counters, counterstmp,
1044 repl->num_counters * sizeof(struct ebt_counter))) {
1045 /* Silent error, can't fail, new table is already in place */
1046 net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n");
1047 }
1048
1049 /* decrease module count and free resources */
1050 EBT_ENTRY_ITERATE(table->entries, table->entries_size,
1051 ebt_cleanup_entry, net, NULL);
1052
1053 vfree(table->entries);
1054 if (table->chainstack) {
1055 for_each_possible_cpu(i)
1056 vfree(table->chainstack[i]);
1057 vfree(table->chainstack);
1058 }
1059 vfree(table);
1060
1061 vfree(counterstmp);
1062
1063 #ifdef CONFIG_AUDIT
1064 if (audit_enabled) {
1065 audit_log(current->audit_context, GFP_KERNEL,
1066 AUDIT_NETFILTER_CFG,
1067 "table=%s family=%u entries=%u",
1068 repl->name, AF_BRIDGE, repl->nentries);
1069 }
1070 #endif
1071 return ret;
1072
1073 free_unlock:
1074 mutex_unlock(&ebt_mutex);
1075 free_iterate:
1076 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
1077 ebt_cleanup_entry, net, NULL);
1078 free_counterstmp:
1079 vfree(counterstmp);
1080 /* can be initialized in translate_table() */
1081 if (newinfo->chainstack) {
1082 for_each_possible_cpu(i)
1083 vfree(newinfo->chainstack[i]);
1084 vfree(newinfo->chainstack);
1085 }
1086 return ret;
1087 }
1088
1089 /* replace the table */
1090 static int do_replace(struct net *net, const void __user *user,
1091 unsigned int len)
1092 {
1093 int ret, countersize;
1094 struct ebt_table_info *newinfo;
1095 struct ebt_replace tmp;
1096
1097 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1098 return -EFAULT;
1099
1100 if (len != sizeof(tmp) + tmp.entries_size) {
1101 BUGPRINT("Wrong len argument\n");
1102 return -EINVAL;
1103 }
1104
1105 if (tmp.entries_size == 0) {
1106 BUGPRINT("Entries_size never zero\n");
1107 return -EINVAL;
1108 }
1109 /* overflow check */
1110 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
1111 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
1112 return -ENOMEM;
1113 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
1114 return -ENOMEM;
1115
1116 tmp.name[sizeof(tmp.name) - 1] = 0;
1117
1118 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
1119 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1120 if (!newinfo)
1121 return -ENOMEM;
1122
1123 if (countersize)
1124 memset(newinfo->counters, 0, countersize);
1125
1126 newinfo->entries = vmalloc(tmp.entries_size);
1127 if (!newinfo->entries) {
1128 ret = -ENOMEM;
1129 goto free_newinfo;
1130 }
1131 if (copy_from_user(
1132 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
1133 BUGPRINT("Couldn't copy entries from userspace\n");
1134 ret = -EFAULT;
1135 goto free_entries;
1136 }
1137
1138 ret = do_replace_finish(net, &tmp, newinfo);
1139 if (ret == 0)
1140 return ret;
1141 free_entries:
1142 vfree(newinfo->entries);
1143 free_newinfo:
1144 vfree(newinfo);
1145 return ret;
1146 }
1147
1148 static void __ebt_unregister_table(struct net *net, struct ebt_table *table)
1149 {
1150 int i;
1151
1152 mutex_lock(&ebt_mutex);
1153 list_del(&table->list);
1154 mutex_unlock(&ebt_mutex);
1155 EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
1156 ebt_cleanup_entry, net, NULL);
1157 if (table->private->nentries)
1158 module_put(table->me);
1159 vfree(table->private->entries);
1160 if (table->private->chainstack) {
1161 for_each_possible_cpu(i)
1162 vfree(table->private->chainstack[i]);
1163 vfree(table->private->chainstack);
1164 }
1165 vfree(table->private);
1166 kfree(table);
1167 }
1168
1169 int ebt_register_table(struct net *net, const struct ebt_table *input_table,
1170 const struct nf_hook_ops *ops, struct ebt_table **res)
1171 {
1172 struct ebt_table_info *newinfo;
1173 struct ebt_table *t, *table;
1174 struct ebt_replace_kernel *repl;
1175 int ret, i, countersize;
1176 void *p;
1177
1178 if (input_table == NULL || (repl = input_table->table) == NULL ||
1179 repl->entries == NULL || repl->entries_size == 0 ||
1180 repl->counters != NULL || input_table->private != NULL) {
1181 BUGPRINT("Bad table data for ebt_register_table!!!\n");
1182 return -EINVAL;
1183 }
1184
1185 /* Don't add one table to multiple lists. */
1186 table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL);
1187 if (!table) {
1188 ret = -ENOMEM;
1189 goto out;
1190 }
1191
1192 countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
1193 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1194 ret = -ENOMEM;
1195 if (!newinfo)
1196 goto free_table;
1197
1198 p = vmalloc(repl->entries_size);
1199 if (!p)
1200 goto free_newinfo;
1201
1202 memcpy(p, repl->entries, repl->entries_size);
1203 newinfo->entries = p;
1204
1205 newinfo->entries_size = repl->entries_size;
1206 newinfo->nentries = repl->nentries;
1207
1208 if (countersize)
1209 memset(newinfo->counters, 0, countersize);
1210
1211 /* fill in newinfo and parse the entries */
1212 newinfo->chainstack = NULL;
1213 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1214 if ((repl->valid_hooks & (1 << i)) == 0)
1215 newinfo->hook_entry[i] = NULL;
1216 else
1217 newinfo->hook_entry[i] = p +
1218 ((char *)repl->hook_entry[i] - repl->entries);
1219 }
1220 ret = translate_table(net, repl->name, newinfo);
1221 if (ret != 0) {
1222 BUGPRINT("Translate_table failed\n");
1223 goto free_chainstack;
1224 }
1225
1226 if (table->check && table->check(newinfo, table->valid_hooks)) {
1227 BUGPRINT("The table doesn't like its own initial data, lol\n");
1228 ret = -EINVAL;
1229 goto free_chainstack;
1230 }
1231
1232 table->private = newinfo;
1233 rwlock_init(&table->lock);
1234 mutex_lock(&ebt_mutex);
1235 list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
1236 if (strcmp(t->name, table->name) == 0) {
1237 ret = -EEXIST;
1238 BUGPRINT("Table name already exists\n");
1239 goto free_unlock;
1240 }
1241 }
1242
1243 /* Hold a reference count if the chains aren't empty */
1244 if (newinfo->nentries && !try_module_get(table->me)) {
1245 ret = -ENOENT;
1246 goto free_unlock;
1247 }
1248 list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
1249 mutex_unlock(&ebt_mutex);
1250
1251 WRITE_ONCE(*res, table);
1252
1253 if (!ops)
1254 return 0;
1255
1256 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
1257 if (ret) {
1258 __ebt_unregister_table(net, table);
1259 *res = NULL;
1260 }
1261
1262 return ret;
1263 free_unlock:
1264 mutex_unlock(&ebt_mutex);
1265 free_chainstack:
1266 if (newinfo->chainstack) {
1267 for_each_possible_cpu(i)
1268 vfree(newinfo->chainstack[i]);
1269 vfree(newinfo->chainstack);
1270 }
1271 vfree(newinfo->entries);
1272 free_newinfo:
1273 vfree(newinfo);
1274 free_table:
1275 kfree(table);
1276 out:
1277 return ret;
1278 }
1279
1280 void ebt_unregister_table(struct net *net, struct ebt_table *table,
1281 const struct nf_hook_ops *ops)
1282 {
1283 if (ops)
1284 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
1285 __ebt_unregister_table(net, table);
1286 }
1287
1288 /* userspace just supplied us with counters */
1289 static int do_update_counters(struct net *net, const char *name,
1290 struct ebt_counter __user *counters,
1291 unsigned int num_counters,
1292 const void __user *user, unsigned int len)
1293 {
1294 int i, ret;
1295 struct ebt_counter *tmp;
1296 struct ebt_table *t;
1297
1298 if (num_counters == 0)
1299 return -EINVAL;
1300
1301 tmp = vmalloc(num_counters * sizeof(*tmp));
1302 if (!tmp)
1303 return -ENOMEM;
1304
1305 t = find_table_lock(net, name, &ret, &ebt_mutex);
1306 if (!t)
1307 goto free_tmp;
1308
1309 if (num_counters != t->private->nentries) {
1310 BUGPRINT("Wrong nr of counters\n");
1311 ret = -EINVAL;
1312 goto unlock_mutex;
1313 }
1314
1315 if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) {
1316 ret = -EFAULT;
1317 goto unlock_mutex;
1318 }
1319
1320 /* we want an atomic add of the counters */
1321 write_lock_bh(&t->lock);
1322
1323 /* we add to the counters of the first cpu */
1324 for (i = 0; i < num_counters; i++)
1325 ADD_COUNTER(t->private->counters[i], tmp[i].pcnt, tmp[i].bcnt);
1326
1327 write_unlock_bh(&t->lock);
1328 ret = 0;
1329 unlock_mutex:
1330 mutex_unlock(&ebt_mutex);
1331 free_tmp:
1332 vfree(tmp);
1333 return ret;
1334 }
1335
1336 static int update_counters(struct net *net, const void __user *user,
1337 unsigned int len)
1338 {
1339 struct ebt_replace hlp;
1340
1341 if (copy_from_user(&hlp, user, sizeof(hlp)))
1342 return -EFAULT;
1343
1344 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
1345 return -EINVAL;
1346
1347 return do_update_counters(net, hlp.name, hlp.counters,
1348 hlp.num_counters, user, len);
1349 }
1350
1351 static inline int ebt_obj_to_user(char __user *um, const char *_name,
1352 const char *data, int entrysize,
1353 int usersize, int datasize, u8 revision)
1354 {
1355 char name[EBT_EXTENSION_MAXNAMELEN] = {0};
1356
1357 /* ebtables expects 31 bytes long names but xt_match names are 29 bytes
1358 * long. Copy 29 bytes and fill remaining bytes with zeroes.
1359 */
1360 strlcpy(name, _name, sizeof(name));
1361 if (copy_to_user(um, name, EBT_EXTENSION_MAXNAMELEN) ||
1362 put_user(revision, (u8 __user *)(um + EBT_EXTENSION_MAXNAMELEN)) ||
1363 put_user(datasize, (int __user *)(um + EBT_EXTENSION_MAXNAMELEN + 1)) ||
1364 xt_data_to_user(um + entrysize, data, usersize, datasize,
1365 XT_ALIGN(datasize)))
1366 return -EFAULT;
1367
1368 return 0;
1369 }
1370
1371 static inline int ebt_match_to_user(const struct ebt_entry_match *m,
1372 const char *base, char __user *ubase)
1373 {
1374 return ebt_obj_to_user(ubase + ((char *)m - base),
1375 m->u.match->name, m->data, sizeof(*m),
1376 m->u.match->usersize, m->match_size,
1377 m->u.match->revision);
1378 }
1379
1380 static inline int ebt_watcher_to_user(const struct ebt_entry_watcher *w,
1381 const char *base, char __user *ubase)
1382 {
1383 return ebt_obj_to_user(ubase + ((char *)w - base),
1384 w->u.watcher->name, w->data, sizeof(*w),
1385 w->u.watcher->usersize, w->watcher_size,
1386 w->u.watcher->revision);
1387 }
1388
1389 static inline int ebt_entry_to_user(struct ebt_entry *e, const char *base,
1390 char __user *ubase)
1391 {
1392 int ret;
1393 char __user *hlp;
1394 const struct ebt_entry_target *t;
1395
1396 if (e->bitmask == 0) {
1397 /* special case !EBT_ENTRY_OR_ENTRIES */
1398 if (copy_to_user(ubase + ((char *)e - base), e,
1399 sizeof(struct ebt_entries)))
1400 return -EFAULT;
1401 return 0;
1402 }
1403
1404 if (copy_to_user(ubase + ((char *)e - base), e, sizeof(*e)))
1405 return -EFAULT;
1406
1407 hlp = ubase + (((char *)e + e->target_offset) - base);
1408 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
1409
1410 ret = EBT_MATCH_ITERATE(e, ebt_match_to_user, base, ubase);
1411 if (ret != 0)
1412 return ret;
1413 ret = EBT_WATCHER_ITERATE(e, ebt_watcher_to_user, base, ubase);
1414 if (ret != 0)
1415 return ret;
1416 ret = ebt_obj_to_user(hlp, t->u.target->name, t->data, sizeof(*t),
1417 t->u.target->usersize, t->target_size,
1418 t->u.target->revision);
1419 if (ret != 0)
1420 return ret;
1421
1422 return 0;
1423 }
1424
1425 static int copy_counters_to_user(struct ebt_table *t,
1426 const struct ebt_counter *oldcounters,
1427 void __user *user, unsigned int num_counters,
1428 unsigned int nentries)
1429 {
1430 struct ebt_counter *counterstmp;
1431 int ret = 0;
1432
1433 /* userspace might not need the counters */
1434 if (num_counters == 0)
1435 return 0;
1436
1437 if (num_counters != nentries) {
1438 BUGPRINT("Num_counters wrong\n");
1439 return -EINVAL;
1440 }
1441
1442 counterstmp = vmalloc(nentries * sizeof(*counterstmp));
1443 if (!counterstmp)
1444 return -ENOMEM;
1445
1446 write_lock_bh(&t->lock);
1447 get_counters(oldcounters, counterstmp, nentries);
1448 write_unlock_bh(&t->lock);
1449
1450 if (copy_to_user(user, counterstmp,
1451 nentries * sizeof(struct ebt_counter)))
1452 ret = -EFAULT;
1453 vfree(counterstmp);
1454 return ret;
1455 }
1456
1457 /* called with ebt_mutex locked */
1458 static int copy_everything_to_user(struct ebt_table *t, void __user *user,
1459 const int *len, int cmd)
1460 {
1461 struct ebt_replace tmp;
1462 const struct ebt_counter *oldcounters;
1463 unsigned int entries_size, nentries;
1464 int ret;
1465 char *entries;
1466
1467 if (cmd == EBT_SO_GET_ENTRIES) {
1468 entries_size = t->private->entries_size;
1469 nentries = t->private->nentries;
1470 entries = t->private->entries;
1471 oldcounters = t->private->counters;
1472 } else {
1473 entries_size = t->table->entries_size;
1474 nentries = t->table->nentries;
1475 entries = t->table->entries;
1476 oldcounters = t->table->counters;
1477 }
1478
1479 if (copy_from_user(&tmp, user, sizeof(tmp)))
1480 return -EFAULT;
1481
1482 if (*len != sizeof(struct ebt_replace) + entries_size +
1483 (tmp.num_counters ? nentries * sizeof(struct ebt_counter) : 0))
1484 return -EINVAL;
1485
1486 if (tmp.nentries != nentries) {
1487 BUGPRINT("Nentries wrong\n");
1488 return -EINVAL;
1489 }
1490
1491 if (tmp.entries_size != entries_size) {
1492 BUGPRINT("Wrong size\n");
1493 return -EINVAL;
1494 }
1495
1496 ret = copy_counters_to_user(t, oldcounters, tmp.counters,
1497 tmp.num_counters, nentries);
1498 if (ret)
1499 return ret;
1500
1501 /* set the match/watcher/target names right */
1502 return EBT_ENTRY_ITERATE(entries, entries_size,
1503 ebt_entry_to_user, entries, tmp.entries);
1504 }
1505
1506 static int do_ebt_set_ctl(struct sock *sk,
1507 int cmd, void __user *user, unsigned int len)
1508 {
1509 int ret;
1510 struct net *net = sock_net(sk);
1511
1512 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1513 return -EPERM;
1514
1515 switch (cmd) {
1516 case EBT_SO_SET_ENTRIES:
1517 ret = do_replace(net, user, len);
1518 break;
1519 case EBT_SO_SET_COUNTERS:
1520 ret = update_counters(net, user, len);
1521 break;
1522 default:
1523 ret = -EINVAL;
1524 }
1525 return ret;
1526 }
1527
1528 static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1529 {
1530 int ret;
1531 struct ebt_replace tmp;
1532 struct ebt_table *t;
1533 struct net *net = sock_net(sk);
1534
1535 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1536 return -EPERM;
1537
1538 if (copy_from_user(&tmp, user, sizeof(tmp)))
1539 return -EFAULT;
1540
1541 tmp.name[sizeof(tmp.name) - 1] = '\0';
1542
1543 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
1544 if (!t)
1545 return ret;
1546
1547 switch (cmd) {
1548 case EBT_SO_GET_INFO:
1549 case EBT_SO_GET_INIT_INFO:
1550 if (*len != sizeof(struct ebt_replace)) {
1551 ret = -EINVAL;
1552 mutex_unlock(&ebt_mutex);
1553 break;
1554 }
1555 if (cmd == EBT_SO_GET_INFO) {
1556 tmp.nentries = t->private->nentries;
1557 tmp.entries_size = t->private->entries_size;
1558 tmp.valid_hooks = t->valid_hooks;
1559 } else {
1560 tmp.nentries = t->table->nentries;
1561 tmp.entries_size = t->table->entries_size;
1562 tmp.valid_hooks = t->table->valid_hooks;
1563 }
1564 mutex_unlock(&ebt_mutex);
1565 if (copy_to_user(user, &tmp, *len) != 0) {
1566 BUGPRINT("c2u Didn't work\n");
1567 ret = -EFAULT;
1568 break;
1569 }
1570 ret = 0;
1571 break;
1572
1573 case EBT_SO_GET_ENTRIES:
1574 case EBT_SO_GET_INIT_ENTRIES:
1575 ret = copy_everything_to_user(t, user, len, cmd);
1576 mutex_unlock(&ebt_mutex);
1577 break;
1578
1579 default:
1580 mutex_unlock(&ebt_mutex);
1581 ret = -EINVAL;
1582 }
1583
1584 return ret;
1585 }
1586
1587 #ifdef CONFIG_COMPAT
1588 /* 32 bit-userspace compatibility definitions. */
1589 struct compat_ebt_replace {
1590 char name[EBT_TABLE_MAXNAMELEN];
1591 compat_uint_t valid_hooks;
1592 compat_uint_t nentries;
1593 compat_uint_t entries_size;
1594 /* start of the chains */
1595 compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
1596 /* nr of counters userspace expects back */
1597 compat_uint_t num_counters;
1598 /* where the kernel will put the old counters. */
1599 compat_uptr_t counters;
1600 compat_uptr_t entries;
1601 };
1602
1603 /* struct ebt_entry_match, _target and _watcher have same layout */
1604 struct compat_ebt_entry_mwt {
1605 union {
1606 struct {
1607 char name[EBT_EXTENSION_MAXNAMELEN];
1608 u8 revision;
1609 };
1610 compat_uptr_t ptr;
1611 } u;
1612 compat_uint_t match_size;
1613 compat_uint_t data[0];
1614 };
1615
1616 /* account for possible padding between match_size and ->data */
1617 static int ebt_compat_entry_padsize(void)
1618 {
1619 BUILD_BUG_ON(XT_ALIGN(sizeof(struct ebt_entry_match)) <
1620 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt)));
1621 return (int) XT_ALIGN(sizeof(struct ebt_entry_match)) -
1622 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt));
1623 }
1624
1625 static int ebt_compat_match_offset(const struct xt_match *match,
1626 unsigned int userlen)
1627 {
1628 /* ebt_among needs special handling. The kernel .matchsize is
1629 * set to -1 at registration time; at runtime an EBT_ALIGN()ed
1630 * value is expected.
1631 * Example: userspace sends 4500, ebt_among.c wants 4504.
1632 */
1633 if (unlikely(match->matchsize == -1))
1634 return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
1635 return xt_compat_match_offset(match);
1636 }
1637
1638 static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
1639 unsigned int *size)
1640 {
1641 const struct xt_match *match = m->u.match;
1642 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1643 int off = ebt_compat_match_offset(match, m->match_size);
1644 compat_uint_t msize = m->match_size - off;
1645
1646 if (WARN_ON(off >= m->match_size))
1647 return -EINVAL;
1648
1649 if (copy_to_user(cm->u.name, match->name, strlen(match->name) + 1) ||
1650 put_user(match->revision, &cm->u.revision) ||
1651 put_user(msize, &cm->match_size))
1652 return -EFAULT;
1653
1654 if (match->compat_to_user) {
1655 if (match->compat_to_user(cm->data, m->data))
1656 return -EFAULT;
1657 } else {
1658 if (xt_data_to_user(cm->data, m->data, match->usersize, msize,
1659 COMPAT_XT_ALIGN(msize)))
1660 return -EFAULT;
1661 }
1662
1663 *size -= ebt_compat_entry_padsize() + off;
1664 *dstptr = cm->data;
1665 *dstptr += msize;
1666 return 0;
1667 }
1668
1669 static int compat_target_to_user(struct ebt_entry_target *t,
1670 void __user **dstptr,
1671 unsigned int *size)
1672 {
1673 const struct xt_target *target = t->u.target;
1674 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1675 int off = xt_compat_target_offset(target);
1676 compat_uint_t tsize = t->target_size - off;
1677
1678 if (WARN_ON(off >= t->target_size))
1679 return -EINVAL;
1680
1681 if (copy_to_user(cm->u.name, target->name, strlen(target->name) + 1) ||
1682 put_user(target->revision, &cm->u.revision) ||
1683 put_user(tsize, &cm->match_size))
1684 return -EFAULT;
1685
1686 if (target->compat_to_user) {
1687 if (target->compat_to_user(cm->data, t->data))
1688 return -EFAULT;
1689 } else {
1690 if (xt_data_to_user(cm->data, t->data, target->usersize, tsize,
1691 COMPAT_XT_ALIGN(tsize)))
1692 return -EFAULT;
1693 }
1694
1695 *size -= ebt_compat_entry_padsize() + off;
1696 *dstptr = cm->data;
1697 *dstptr += tsize;
1698 return 0;
1699 }
1700
1701 static int compat_watcher_to_user(struct ebt_entry_watcher *w,
1702 void __user **dstptr,
1703 unsigned int *size)
1704 {
1705 return compat_target_to_user((struct ebt_entry_target *)w,
1706 dstptr, size);
1707 }
1708
1709 static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
1710 unsigned int *size)
1711 {
1712 struct ebt_entry_target *t;
1713 struct ebt_entry __user *ce;
1714 u32 watchers_offset, target_offset, next_offset;
1715 compat_uint_t origsize;
1716 int ret;
1717
1718 if (e->bitmask == 0) {
1719 if (*size < sizeof(struct ebt_entries))
1720 return -EINVAL;
1721 if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries)))
1722 return -EFAULT;
1723
1724 *dstptr += sizeof(struct ebt_entries);
1725 *size -= sizeof(struct ebt_entries);
1726 return 0;
1727 }
1728
1729 if (*size < sizeof(*ce))
1730 return -EINVAL;
1731
1732 ce = *dstptr;
1733 if (copy_to_user(ce, e, sizeof(*ce)))
1734 return -EFAULT;
1735
1736 origsize = *size;
1737 *dstptr += sizeof(*ce);
1738
1739 ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
1740 if (ret)
1741 return ret;
1742 watchers_offset = e->watchers_offset - (origsize - *size);
1743
1744 ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
1745 if (ret)
1746 return ret;
1747 target_offset = e->target_offset - (origsize - *size);
1748
1749 t = (struct ebt_entry_target *) ((char *) e + e->target_offset);
1750
1751 ret = compat_target_to_user(t, dstptr, size);
1752 if (ret)
1753 return ret;
1754 next_offset = e->next_offset - (origsize - *size);
1755
1756 if (put_user(watchers_offset, &ce->watchers_offset) ||
1757 put_user(target_offset, &ce->target_offset) ||
1758 put_user(next_offset, &ce->next_offset))
1759 return -EFAULT;
1760
1761 *size -= sizeof(*ce);
1762 return 0;
1763 }
1764
1765 static int compat_calc_match(struct ebt_entry_match *m, int *off)
1766 {
1767 *off += ebt_compat_match_offset(m->u.match, m->match_size);
1768 *off += ebt_compat_entry_padsize();
1769 return 0;
1770 }
1771
1772 static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
1773 {
1774 *off += xt_compat_target_offset(w->u.watcher);
1775 *off += ebt_compat_entry_padsize();
1776 return 0;
1777 }
1778
1779 static int compat_calc_entry(const struct ebt_entry *e,
1780 const struct ebt_table_info *info,
1781 const void *base,
1782 struct compat_ebt_replace *newinfo)
1783 {
1784 const struct ebt_entry_target *t;
1785 unsigned int entry_offset;
1786 int off, ret, i;
1787
1788 if (e->bitmask == 0)
1789 return 0;
1790
1791 off = 0;
1792 entry_offset = (void *)e - base;
1793
1794 EBT_MATCH_ITERATE(e, compat_calc_match, &off);
1795 EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
1796
1797 t = (const struct ebt_entry_target *) ((char *) e + e->target_offset);
1798
1799 off += xt_compat_target_offset(t->u.target);
1800 off += ebt_compat_entry_padsize();
1801
1802 newinfo->entries_size -= off;
1803
1804 ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off);
1805 if (ret)
1806 return ret;
1807
1808 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1809 const void *hookptr = info->hook_entry[i];
1810 if (info->hook_entry[i] &&
1811 (e < (struct ebt_entry *)(base - hookptr))) {
1812 newinfo->hook_entry[i] -= off;
1813 pr_debug("0x%08X -> 0x%08X\n",
1814 newinfo->hook_entry[i] + off,
1815 newinfo->hook_entry[i]);
1816 }
1817 }
1818
1819 return 0;
1820 }
1821
1822
1823 static int compat_table_info(const struct ebt_table_info *info,
1824 struct compat_ebt_replace *newinfo)
1825 {
1826 unsigned int size = info->entries_size;
1827 const void *entries = info->entries;
1828 int ret;
1829
1830 newinfo->entries_size = size;
1831
1832 ret = xt_compat_init_offsets(NFPROTO_BRIDGE, info->nentries);
1833 if (ret)
1834 return ret;
1835
1836 return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
1837 entries, newinfo);
1838 }
1839
1840 static int compat_copy_everything_to_user(struct ebt_table *t,
1841 void __user *user, int *len, int cmd)
1842 {
1843 struct compat_ebt_replace repl, tmp;
1844 struct ebt_counter *oldcounters;
1845 struct ebt_table_info tinfo;
1846 int ret;
1847 void __user *pos;
1848
1849 memset(&tinfo, 0, sizeof(tinfo));
1850
1851 if (cmd == EBT_SO_GET_ENTRIES) {
1852 tinfo.entries_size = t->private->entries_size;
1853 tinfo.nentries = t->private->nentries;
1854 tinfo.entries = t->private->entries;
1855 oldcounters = t->private->counters;
1856 } else {
1857 tinfo.entries_size = t->table->entries_size;
1858 tinfo.nentries = t->table->nentries;
1859 tinfo.entries = t->table->entries;
1860 oldcounters = t->table->counters;
1861 }
1862
1863 if (copy_from_user(&tmp, user, sizeof(tmp)))
1864 return -EFAULT;
1865
1866 if (tmp.nentries != tinfo.nentries ||
1867 (tmp.num_counters && tmp.num_counters != tinfo.nentries))
1868 return -EINVAL;
1869
1870 memcpy(&repl, &tmp, sizeof(repl));
1871 if (cmd == EBT_SO_GET_ENTRIES)
1872 ret = compat_table_info(t->private, &repl);
1873 else
1874 ret = compat_table_info(&tinfo, &repl);
1875 if (ret)
1876 return ret;
1877
1878 if (*len != sizeof(tmp) + repl.entries_size +
1879 (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
1880 pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
1881 *len, tinfo.entries_size, repl.entries_size);
1882 return -EINVAL;
1883 }
1884
1885 /* userspace might not need the counters */
1886 ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters),
1887 tmp.num_counters, tinfo.nentries);
1888 if (ret)
1889 return ret;
1890
1891 pos = compat_ptr(tmp.entries);
1892 return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
1893 compat_copy_entry_to_user, &pos, &tmp.entries_size);
1894 }
1895
1896 struct ebt_entries_buf_state {
1897 char *buf_kern_start; /* kernel buffer to copy (translated) data to */
1898 u32 buf_kern_len; /* total size of kernel buffer */
1899 u32 buf_kern_offset; /* amount of data copied so far */
1900 u32 buf_user_offset; /* read position in userspace buffer */
1901 };
1902
1903 static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
1904 {
1905 state->buf_kern_offset += sz;
1906 return state->buf_kern_offset >= sz ? 0 : -EINVAL;
1907 }
1908
1909 static int ebt_buf_add(struct ebt_entries_buf_state *state,
1910 void *data, unsigned int sz)
1911 {
1912 if (state->buf_kern_start == NULL)
1913 goto count_only;
1914
1915 if (WARN_ON(state->buf_kern_offset + sz > state->buf_kern_len))
1916 return -EINVAL;
1917
1918 memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz);
1919
1920 count_only:
1921 state->buf_user_offset += sz;
1922 return ebt_buf_count(state, sz);
1923 }
1924
1925 static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz)
1926 {
1927 char *b = state->buf_kern_start;
1928
1929 if (WARN_ON(b && state->buf_kern_offset > state->buf_kern_len))
1930 return -EINVAL;
1931
1932 if (b != NULL && sz > 0)
1933 memset(b + state->buf_kern_offset, 0, sz);
1934 /* do not adjust ->buf_user_offset here, we added kernel-side padding */
1935 return ebt_buf_count(state, sz);
1936 }
1937
1938 enum compat_mwt {
1939 EBT_COMPAT_MATCH,
1940 EBT_COMPAT_WATCHER,
1941 EBT_COMPAT_TARGET,
1942 };
1943
1944 static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt,
1945 enum compat_mwt compat_mwt,
1946 struct ebt_entries_buf_state *state,
1947 const unsigned char *base)
1948 {
1949 char name[EBT_EXTENSION_MAXNAMELEN];
1950 struct xt_match *match;
1951 struct xt_target *wt;
1952 void *dst = NULL;
1953 int off, pad = 0;
1954 unsigned int size_kern, match_size = mwt->match_size;
1955
1956 strlcpy(name, mwt->u.name, sizeof(name));
1957
1958 if (state->buf_kern_start)
1959 dst = state->buf_kern_start + state->buf_kern_offset;
1960
1961 switch (compat_mwt) {
1962 case EBT_COMPAT_MATCH:
1963 match = xt_request_find_match(NFPROTO_BRIDGE, name,
1964 mwt->u.revision);
1965 if (IS_ERR(match))
1966 return PTR_ERR(match);
1967
1968 off = ebt_compat_match_offset(match, match_size);
1969 if (dst) {
1970 if (match->compat_from_user)
1971 match->compat_from_user(dst, mwt->data);
1972 else
1973 memcpy(dst, mwt->data, match_size);
1974 }
1975
1976 size_kern = match->matchsize;
1977 if (unlikely(size_kern == -1))
1978 size_kern = match_size;
1979 module_put(match->me);
1980 break;
1981 case EBT_COMPAT_WATCHER: /* fallthrough */
1982 case EBT_COMPAT_TARGET:
1983 wt = xt_request_find_target(NFPROTO_BRIDGE, name,
1984 mwt->u.revision);
1985 if (IS_ERR(wt))
1986 return PTR_ERR(wt);
1987 off = xt_compat_target_offset(wt);
1988
1989 if (dst) {
1990 if (wt->compat_from_user)
1991 wt->compat_from_user(dst, mwt->data);
1992 else
1993 memcpy(dst, mwt->data, match_size);
1994 }
1995
1996 size_kern = wt->targetsize;
1997 module_put(wt->me);
1998 break;
1999
2000 default:
2001 return -EINVAL;
2002 }
2003
2004 state->buf_kern_offset += match_size + off;
2005 state->buf_user_offset += match_size;
2006 pad = XT_ALIGN(size_kern) - size_kern;
2007
2008 if (pad > 0 && dst) {
2009 if (WARN_ON(state->buf_kern_len <= pad))
2010 return -EINVAL;
2011 if (WARN_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad))
2012 return -EINVAL;
2013 memset(dst + size_kern, 0, pad);
2014 }
2015 return off + match_size;
2016 }
2017
2018 /* return size of all matches, watchers or target, including necessary
2019 * alignment and padding.
2020 */
2021 static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32,
2022 unsigned int size_left, enum compat_mwt type,
2023 struct ebt_entries_buf_state *state, const void *base)
2024 {
2025 int growth = 0;
2026 char *buf;
2027
2028 if (size_left == 0)
2029 return 0;
2030
2031 buf = (char *) match32;
2032
2033 while (size_left >= sizeof(*match32)) {
2034 struct ebt_entry_match *match_kern;
2035 int ret;
2036
2037 match_kern = (struct ebt_entry_match *) state->buf_kern_start;
2038 if (match_kern) {
2039 char *tmp;
2040 tmp = state->buf_kern_start + state->buf_kern_offset;
2041 match_kern = (struct ebt_entry_match *) tmp;
2042 }
2043 ret = ebt_buf_add(state, buf, sizeof(*match32));
2044 if (ret < 0)
2045 return ret;
2046 size_left -= sizeof(*match32);
2047
2048 /* add padding before match->data (if any) */
2049 ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize());
2050 if (ret < 0)
2051 return ret;
2052
2053 if (match32->match_size > size_left)
2054 return -EINVAL;
2055
2056 size_left -= match32->match_size;
2057
2058 ret = compat_mtw_from_user(match32, type, state, base);
2059 if (ret < 0)
2060 return ret;
2061
2062 if (WARN_ON(ret < match32->match_size))
2063 return -EINVAL;
2064 growth += ret - match32->match_size;
2065 growth += ebt_compat_entry_padsize();
2066
2067 buf += sizeof(*match32);
2068 buf += match32->match_size;
2069
2070 if (match_kern)
2071 match_kern->match_size = ret;
2072
2073 if (WARN_ON(type == EBT_COMPAT_TARGET && size_left))
2074 return -EINVAL;
2075
2076 match32 = (struct compat_ebt_entry_mwt *) buf;
2077 }
2078
2079 return growth;
2080 }
2081
2082 /* called for all ebt_entry structures. */
2083 static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,
2084 unsigned int *total,
2085 struct ebt_entries_buf_state *state)
2086 {
2087 unsigned int i, j, startoff, new_offset = 0;
2088 /* stores match/watchers/targets & offset of next struct ebt_entry: */
2089 unsigned int offsets[4];
2090 unsigned int *offsets_update = NULL;
2091 int ret;
2092 char *buf_start;
2093
2094 if (*total < sizeof(struct ebt_entries))
2095 return -EINVAL;
2096
2097 if (!entry->bitmask) {
2098 *total -= sizeof(struct ebt_entries);
2099 return ebt_buf_add(state, entry, sizeof(struct ebt_entries));
2100 }
2101 if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
2102 return -EINVAL;
2103
2104 startoff = state->buf_user_offset;
2105 /* pull in most part of ebt_entry, it does not need to be changed. */
2106 ret = ebt_buf_add(state, entry,
2107 offsetof(struct ebt_entry, watchers_offset));
2108 if (ret < 0)
2109 return ret;
2110
2111 offsets[0] = sizeof(struct ebt_entry); /* matches come first */
2112 memcpy(&offsets[1], &entry->watchers_offset,
2113 sizeof(offsets) - sizeof(offsets[0]));
2114
2115 if (state->buf_kern_start) {
2116 buf_start = state->buf_kern_start + state->buf_kern_offset;
2117 offsets_update = (unsigned int *) buf_start;
2118 }
2119 ret = ebt_buf_add(state, &offsets[1],
2120 sizeof(offsets) - sizeof(offsets[0]));
2121 if (ret < 0)
2122 return ret;
2123 buf_start = (char *) entry;
2124 /* 0: matches offset, always follows ebt_entry.
2125 * 1: watchers offset, from ebt_entry structure
2126 * 2: target offset, from ebt_entry structure
2127 * 3: next ebt_entry offset, from ebt_entry structure
2128 *
2129 * offsets are relative to beginning of struct ebt_entry (i.e., 0).
2130 */
2131 for (i = 0; i < 4 ; ++i) {
2132 if (offsets[i] > *total)
2133 return -EINVAL;
2134
2135 if (i < 3 && offsets[i] == *total)
2136 return -EINVAL;
2137
2138 if (i == 0)
2139 continue;
2140 if (offsets[i-1] > offsets[i])
2141 return -EINVAL;
2142 }
2143
2144 for (i = 0, j = 1 ; j < 4 ; j++, i++) {
2145 struct compat_ebt_entry_mwt *match32;
2146 unsigned int size;
2147 char *buf = buf_start + offsets[i];
2148
2149 if (offsets[i] > offsets[j])
2150 return -EINVAL;
2151
2152 match32 = (struct compat_ebt_entry_mwt *) buf;
2153 size = offsets[j] - offsets[i];
2154 ret = ebt_size_mwt(match32, size, i, state, base);
2155 if (ret < 0)
2156 return ret;
2157 new_offset += ret;
2158 if (offsets_update && new_offset) {
2159 pr_debug("change offset %d to %d\n",
2160 offsets_update[i], offsets[j] + new_offset);
2161 offsets_update[i] = offsets[j] + new_offset;
2162 }
2163 }
2164
2165 if (state->buf_kern_start == NULL) {
2166 unsigned int offset = buf_start - (char *) base;
2167
2168 ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);
2169 if (ret < 0)
2170 return ret;
2171 }
2172
2173 startoff = state->buf_user_offset - startoff;
2174
2175 if (WARN_ON(*total < startoff))
2176 return -EINVAL;
2177 *total -= startoff;
2178 return 0;
2179 }
2180
2181 /* repl->entries_size is the size of the ebt_entry blob in userspace.
2182 * It might need more memory when copied to a 64 bit kernel in case
2183 * userspace is 32-bit. So, first task: find out how much memory is needed.
2184 *
2185 * Called before validation is performed.
2186 */
2187 static int compat_copy_entries(unsigned char *data, unsigned int size_user,
2188 struct ebt_entries_buf_state *state)
2189 {
2190 unsigned int size_remaining = size_user;
2191 int ret;
2192
2193 ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
2194 &size_remaining, state);
2195 if (ret < 0)
2196 return ret;
2197
2198 WARN_ON(size_remaining);
2199 return state->buf_kern_offset;
2200 }
2201
2202
2203 static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
2204 void __user *user, unsigned int len)
2205 {
2206 struct compat_ebt_replace tmp;
2207 int i;
2208
2209 if (len < sizeof(tmp))
2210 return -EINVAL;
2211
2212 if (copy_from_user(&tmp, user, sizeof(tmp)))
2213 return -EFAULT;
2214
2215 if (len != sizeof(tmp) + tmp.entries_size)
2216 return -EINVAL;
2217
2218 if (tmp.entries_size == 0)
2219 return -EINVAL;
2220
2221 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
2222 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
2223 return -ENOMEM;
2224 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
2225 return -ENOMEM;
2226
2227 memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
2228
2229 /* starting with hook_entry, 32 vs. 64 bit structures are different */
2230 for (i = 0; i < NF_BR_NUMHOOKS; i++)
2231 repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]);
2232
2233 repl->num_counters = tmp.num_counters;
2234 repl->counters = compat_ptr(tmp.counters);
2235 repl->entries = compat_ptr(tmp.entries);
2236 return 0;
2237 }
2238
2239 static int compat_do_replace(struct net *net, void __user *user,
2240 unsigned int len)
2241 {
2242 int ret, i, countersize, size64;
2243 struct ebt_table_info *newinfo;
2244 struct ebt_replace tmp;
2245 struct ebt_entries_buf_state state;
2246 void *entries_tmp;
2247
2248 ret = compat_copy_ebt_replace_from_user(&tmp, user, len);
2249 if (ret) {
2250 /* try real handler in case userland supplied needed padding */
2251 if (ret == -EINVAL && do_replace(net, user, len) == 0)
2252 ret = 0;
2253 return ret;
2254 }
2255
2256 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
2257 newinfo = vmalloc(sizeof(*newinfo) + countersize);
2258 if (!newinfo)
2259 return -ENOMEM;
2260
2261 if (countersize)
2262 memset(newinfo->counters, 0, countersize);
2263
2264 memset(&state, 0, sizeof(state));
2265
2266 newinfo->entries = vmalloc(tmp.entries_size);
2267 if (!newinfo->entries) {
2268 ret = -ENOMEM;
2269 goto free_newinfo;
2270 }
2271 if (copy_from_user(
2272 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
2273 ret = -EFAULT;
2274 goto free_entries;
2275 }
2276
2277 entries_tmp = newinfo->entries;
2278
2279 xt_compat_lock(NFPROTO_BRIDGE);
2280
2281 ret = xt_compat_init_offsets(NFPROTO_BRIDGE, tmp.nentries);
2282 if (ret < 0)
2283 goto out_unlock;
2284 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2285 if (ret < 0)
2286 goto out_unlock;
2287
2288 pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
2289 tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
2290 xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
2291
2292 size64 = ret;
2293 newinfo->entries = vmalloc(size64);
2294 if (!newinfo->entries) {
2295 vfree(entries_tmp);
2296 ret = -ENOMEM;
2297 goto out_unlock;
2298 }
2299
2300 memset(&state, 0, sizeof(state));
2301 state.buf_kern_start = newinfo->entries;
2302 state.buf_kern_len = size64;
2303
2304 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2305 if (WARN_ON(ret < 0))
2306 goto out_unlock;
2307
2308 vfree(entries_tmp);
2309 tmp.entries_size = size64;
2310
2311 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
2312 char __user *usrptr;
2313 if (tmp.hook_entry[i]) {
2314 unsigned int delta;
2315 usrptr = (char __user *) tmp.hook_entry[i];
2316 delta = usrptr - tmp.entries;
2317 usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta);
2318 tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
2319 }
2320 }
2321
2322 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2323 xt_compat_unlock(NFPROTO_BRIDGE);
2324
2325 ret = do_replace_finish(net, &tmp, newinfo);
2326 if (ret == 0)
2327 return ret;
2328 free_entries:
2329 vfree(newinfo->entries);
2330 free_newinfo:
2331 vfree(newinfo);
2332 return ret;
2333 out_unlock:
2334 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2335 xt_compat_unlock(NFPROTO_BRIDGE);
2336 goto free_entries;
2337 }
2338
2339 static int compat_update_counters(struct net *net, void __user *user,
2340 unsigned int len)
2341 {
2342 struct compat_ebt_replace hlp;
2343
2344 if (copy_from_user(&hlp, user, sizeof(hlp)))
2345 return -EFAULT;
2346
2347 /* try real handler in case userland supplied needed padding */
2348 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
2349 return update_counters(net, user, len);
2350
2351 return do_update_counters(net, hlp.name, compat_ptr(hlp.counters),
2352 hlp.num_counters, user, len);
2353 }
2354
2355 static int compat_do_ebt_set_ctl(struct sock *sk,
2356 int cmd, void __user *user, unsigned int len)
2357 {
2358 int ret;
2359 struct net *net = sock_net(sk);
2360
2361 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2362 return -EPERM;
2363
2364 switch (cmd) {
2365 case EBT_SO_SET_ENTRIES:
2366 ret = compat_do_replace(net, user, len);
2367 break;
2368 case EBT_SO_SET_COUNTERS:
2369 ret = compat_update_counters(net, user, len);
2370 break;
2371 default:
2372 ret = -EINVAL;
2373 }
2374 return ret;
2375 }
2376
2377 static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
2378 void __user *user, int *len)
2379 {
2380 int ret;
2381 struct compat_ebt_replace tmp;
2382 struct ebt_table *t;
2383 struct net *net = sock_net(sk);
2384
2385 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2386 return -EPERM;
2387
2388 /* try real handler in case userland supplied needed padding */
2389 if ((cmd == EBT_SO_GET_INFO ||
2390 cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp))
2391 return do_ebt_get_ctl(sk, cmd, user, len);
2392
2393 if (copy_from_user(&tmp, user, sizeof(tmp)))
2394 return -EFAULT;
2395
2396 tmp.name[sizeof(tmp.name) - 1] = '\0';
2397
2398 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
2399 if (!t)
2400 return ret;
2401
2402 xt_compat_lock(NFPROTO_BRIDGE);
2403 switch (cmd) {
2404 case EBT_SO_GET_INFO:
2405 tmp.nentries = t->private->nentries;
2406 ret = compat_table_info(t->private, &tmp);
2407 if (ret)
2408 goto out;
2409 tmp.valid_hooks = t->valid_hooks;
2410
2411 if (copy_to_user(user, &tmp, *len) != 0) {
2412 ret = -EFAULT;
2413 break;
2414 }
2415 ret = 0;
2416 break;
2417 case EBT_SO_GET_INIT_INFO:
2418 tmp.nentries = t->table->nentries;
2419 tmp.entries_size = t->table->entries_size;
2420 tmp.valid_hooks = t->table->valid_hooks;
2421
2422 if (copy_to_user(user, &tmp, *len) != 0) {
2423 ret = -EFAULT;
2424 break;
2425 }
2426 ret = 0;
2427 break;
2428 case EBT_SO_GET_ENTRIES:
2429 case EBT_SO_GET_INIT_ENTRIES:
2430 /* try real handler first in case of userland-side padding.
2431 * in case we are dealing with an 'ordinary' 32 bit binary
2432 * without 64bit compatibility padding, this will fail right
2433 * after copy_from_user when the *len argument is validated.
2434 *
2435 * the compat_ variant needs to do one pass over the kernel
2436 * data set to adjust for size differences before it the check.
2437 */
2438 if (copy_everything_to_user(t, user, len, cmd) == 0)
2439 ret = 0;
2440 else
2441 ret = compat_copy_everything_to_user(t, user, len, cmd);
2442 break;
2443 default:
2444 ret = -EINVAL;
2445 }
2446 out:
2447 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2448 xt_compat_unlock(NFPROTO_BRIDGE);
2449 mutex_unlock(&ebt_mutex);
2450 return ret;
2451 }
2452 #endif
2453
2454 static struct nf_sockopt_ops ebt_sockopts = {
2455 .pf = PF_INET,
2456 .set_optmin = EBT_BASE_CTL,
2457 .set_optmax = EBT_SO_SET_MAX + 1,
2458 .set = do_ebt_set_ctl,
2459 #ifdef CONFIG_COMPAT
2460 .compat_set = compat_do_ebt_set_ctl,
2461 #endif
2462 .get_optmin = EBT_BASE_CTL,
2463 .get_optmax = EBT_SO_GET_MAX + 1,
2464 .get = do_ebt_get_ctl,
2465 #ifdef CONFIG_COMPAT
2466 .compat_get = compat_do_ebt_get_ctl,
2467 #endif
2468 .owner = THIS_MODULE,
2469 };
2470
2471 static int __init ebtables_init(void)
2472 {
2473 int ret;
2474
2475 ret = xt_register_target(&ebt_standard_target);
2476 if (ret < 0)
2477 return ret;
2478 ret = nf_register_sockopt(&ebt_sockopts);
2479 if (ret < 0) {
2480 xt_unregister_target(&ebt_standard_target);
2481 return ret;
2482 }
2483
2484 return 0;
2485 }
2486
2487 static void __exit ebtables_fini(void)
2488 {
2489 nf_unregister_sockopt(&ebt_sockopts);
2490 xt_unregister_target(&ebt_standard_target);
2491 }
2492
2493 EXPORT_SYMBOL(ebt_register_table);
2494 EXPORT_SYMBOL(ebt_unregister_table);
2495 EXPORT_SYMBOL(ebt_do_table);
2496 module_init(ebtables_init);
2497 module_exit(ebtables_fini);
2498 MODULE_LICENSE("GPL");
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