?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
ARM: dma-api: fix max_pfn off-by-one error in __dma_supported()
[linux/fpc-iii.git] / net / bridge / netfilter / ebtables.c
blobe1256e03a9a86b5b1249895a0627f7fbfa8e3386
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * ebtables
4 *
5 * Author:
6 * Bart De Schuymer <bdschuym@pandora.be>
7 *
8 * ebtables.c,v 2.0, July, 2002
9 *
10 * This code is strongly inspired by the iptables code which is
11 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
12 */
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/kmod.h>
15 #include <linux/module.h>
16 #include <linux/vmalloc.h>
17 #include <linux/netfilter/x_tables.h>
18 #include <linux/netfilter_bridge/ebtables.h>
19 #include <linux/spinlock.h>
20 #include <linux/mutex.h>
21 #include <linux/slab.h>
22 #include <linux/uaccess.h>
23 #include <linux/smp.h>
24 #include <linux/cpumask.h>
25 #include <linux/audit.h>
26 #include <net/sock.h>
27 /* needed for logical [in,out]-dev filtering */
28 #include "../br_private.h"
29
30 /* Each cpu has its own set of counters, so there is no need for write_lock in
31 * the softirq
32 * For reading or updating the counters, the user context needs to
33 * get a write_lock
34 */
35
36 /* The size of each set of counters is altered to get cache alignment */
37 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
38 #define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter)))
39 #define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \
40 COUNTER_OFFSET(n) * cpu))
41
42
43
44 static DEFINE_MUTEX(ebt_mutex);
45
46 #ifdef CONFIG_COMPAT
47 static void ebt_standard_compat_from_user(void *dst, const void *src)
48 {
49 int v = *(compat_int_t *)src;
50
51 if (v >= 0)
52 v += xt_compat_calc_jump(NFPROTO_BRIDGE, v);
53 memcpy(dst, &v, sizeof(v));
54 }
55
56 static int ebt_standard_compat_to_user(void __user *dst, const void *src)
57 {
58 compat_int_t cv = *(int *)src;
59
60 if (cv >= 0)
61 cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv);
62 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
63 }
64 #endif
65
66
67 static struct xt_target ebt_standard_target = {
68 .name = "standard",
69 .revision = 0,
70 .family = NFPROTO_BRIDGE,
71 .targetsize = sizeof(int),
72 #ifdef CONFIG_COMPAT
73 .compatsize = sizeof(compat_int_t),
74 .compat_from_user = ebt_standard_compat_from_user,
75 .compat_to_user = ebt_standard_compat_to_user,
76 #endif
77 };
78
79 static inline int
80 ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb,
81 struct xt_action_param *par)
82 {
83 par->target = w->u.watcher;
84 par->targinfo = w->data;
85 w->u.watcher->target(skb, par);
86 /* watchers don't give a verdict */
87 return 0;
88 }
89
90 static inline int
91 ebt_do_match(struct ebt_entry_match *m, const struct sk_buff *skb,
92 struct xt_action_param *par)
93 {
94 par->match = m->u.match;
95 par->matchinfo = m->data;
96 return !m->u.match->match(skb, par);
97 }
98
99 static inline int
100 ebt_dev_check(const char *entry, const struct net_device *device)
101 {
102 int i = 0;
103 const char *devname;
104
105 if (*entry == '\0')
106 return 0;
107 if (!device)
108 return 1;
109 devname = device->name;
110 /* 1 is the wildcard token */
111 while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i])
112 i++;
113 return devname[i] != entry[i] && entry[i] != 1;
114 }
115
116 /* process standard matches */
117 static inline int
118 ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb,
119 const struct net_device *in, const struct net_device *out)
120 {
121 const struct ethhdr *h = eth_hdr(skb);
122 const struct net_bridge_port *p;
123 __be16 ethproto;
124
125 if (skb_vlan_tag_present(skb))
126 ethproto = htons(ETH_P_8021Q);
127 else
128 ethproto = h->h_proto;
129
130 if (e->bitmask & EBT_802_3) {
131 if (NF_INVF(e, EBT_IPROTO, eth_proto_is_802_3(ethproto)))
132 return 1;
133 } else if (!(e->bitmask & EBT_NOPROTO) &&
134 NF_INVF(e, EBT_IPROTO, e->ethproto != ethproto))
135 return 1;
136
137 if (NF_INVF(e, EBT_IIN, ebt_dev_check(e->in, in)))
138 return 1;
139 if (NF_INVF(e, EBT_IOUT, ebt_dev_check(e->out, out)))
140 return 1;
141 /* rcu_read_lock()ed by nf_hook_thresh */
142 if (in && (p = br_port_get_rcu(in)) != NULL &&
143 NF_INVF(e, EBT_ILOGICALIN,
144 ebt_dev_check(e->logical_in, p->br->dev)))
145 return 1;
146 if (out && (p = br_port_get_rcu(out)) != NULL &&
147 NF_INVF(e, EBT_ILOGICALOUT,
148 ebt_dev_check(e->logical_out, p->br->dev)))
149 return 1;
150
151 if (e->bitmask & EBT_SOURCEMAC) {
152 if (NF_INVF(e, EBT_ISOURCE,
153 !ether_addr_equal_masked(h->h_source, e->sourcemac,
154 e->sourcemsk)))
155 return 1;
156 }
157 if (e->bitmask & EBT_DESTMAC) {
158 if (NF_INVF(e, EBT_IDEST,
159 !ether_addr_equal_masked(h->h_dest, e->destmac,
160 e->destmsk)))
161 return 1;
162 }
163 return 0;
164 }
165
166 static inline
167 struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry)
168 {
169 return (void *)entry + entry->next_offset;
170 }
171
172 static inline const struct ebt_entry_target *
173 ebt_get_target_c(const struct ebt_entry *e)
174 {
175 return ebt_get_target((struct ebt_entry *)e);
176 }
177
178 /* Do some firewalling */
179 unsigned int ebt_do_table(struct sk_buff *skb,
180 const struct nf_hook_state *state,
181 struct ebt_table *table)
182 {
183 unsigned int hook = state->hook;
184 int i, nentries;
185 struct ebt_entry *point;
186 struct ebt_counter *counter_base, *cb_base;
187 const struct ebt_entry_target *t;
188 int verdict, sp = 0;
189 struct ebt_chainstack *cs;
190 struct ebt_entries *chaininfo;
191 const char *base;
192 const struct ebt_table_info *private;
193 struct xt_action_param acpar;
194
195 acpar.state = state;
196 acpar.hotdrop = false;
197
198 read_lock_bh(&table->lock);
199 private = table->private;
200 cb_base = COUNTER_BASE(private->counters, private->nentries,
201 smp_processor_id());
202 if (private->chainstack)
203 cs = private->chainstack[smp_processor_id()];
204 else
205 cs = NULL;
206 chaininfo = private->hook_entry[hook];
207 nentries = private->hook_entry[hook]->nentries;
208 point = (struct ebt_entry *)(private->hook_entry[hook]->data);
209 counter_base = cb_base + private->hook_entry[hook]->counter_offset;
210 /* base for chain jumps */
211 base = private->entries;
212 i = 0;
213 while (i < nentries) {
214 if (ebt_basic_match(point, skb, state->in, state->out))
215 goto letscontinue;
216
217 if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0)
218 goto letscontinue;
219 if (acpar.hotdrop) {
220 read_unlock_bh(&table->lock);
221 return NF_DROP;
222 }
223
224 ADD_COUNTER(*(counter_base + i), skb->len, 1);
225
226 /* these should only watch: not modify, nor tell us
227 * what to do with the packet
228 */
229 EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar);
230
231 t = ebt_get_target_c(point);
232 /* standard target */
233 if (!t->u.target->target)
234 verdict = ((struct ebt_standard_target *)t)->verdict;
235 else {
236 acpar.target = t->u.target;
237 acpar.targinfo = t->data;
238 verdict = t->u.target->target(skb, &acpar);
239 }
240 if (verdict == EBT_ACCEPT) {
241 read_unlock_bh(&table->lock);
242 return NF_ACCEPT;
243 }
244 if (verdict == EBT_DROP) {
245 read_unlock_bh(&table->lock);
246 return NF_DROP;
247 }
248 if (verdict == EBT_RETURN) {
249 letsreturn:
250 if (WARN(sp == 0, "RETURN on base chain")) {
251 /* act like this is EBT_CONTINUE */
252 goto letscontinue;
253 }
254
255 sp--;
256 /* put all the local variables right */
257 i = cs[sp].n;
258 chaininfo = cs[sp].chaininfo;
259 nentries = chaininfo->nentries;
260 point = cs[sp].e;
261 counter_base = cb_base +
262 chaininfo->counter_offset;
263 continue;
264 }
265 if (verdict == EBT_CONTINUE)
266 goto letscontinue;
267
268 if (WARN(verdict < 0, "bogus standard verdict\n")) {
269 read_unlock_bh(&table->lock);
270 return NF_DROP;
271 }
272
273 /* jump to a udc */
274 cs[sp].n = i + 1;
275 cs[sp].chaininfo = chaininfo;
276 cs[sp].e = ebt_next_entry(point);
277 i = 0;
278 chaininfo = (struct ebt_entries *) (base + verdict);
279
280 if (WARN(chaininfo->distinguisher, "jump to non-chain\n")) {
281 read_unlock_bh(&table->lock);
282 return NF_DROP;
283 }
284
285 nentries = chaininfo->nentries;
286 point = (struct ebt_entry *)chaininfo->data;
287 counter_base = cb_base + chaininfo->counter_offset;
288 sp++;
289 continue;
290 letscontinue:
291 point = ebt_next_entry(point);
292 i++;
293 }
294
295 /* I actually like this :) */
296 if (chaininfo->policy == EBT_RETURN)
297 goto letsreturn;
298 if (chaininfo->policy == EBT_ACCEPT) {
299 read_unlock_bh(&table->lock);
300 return NF_ACCEPT;
301 }
302 read_unlock_bh(&table->lock);
303 return NF_DROP;
304 }
305
306 /* If it succeeds, returns element and locks mutex */
307 static inline void *
308 find_inlist_lock_noload(struct list_head *head, const char *name, int *error,
309 struct mutex *mutex)
310 {
311 struct {
312 struct list_head list;
313 char name[EBT_FUNCTION_MAXNAMELEN];
314 } *e;
315
316 mutex_lock(mutex);
317 list_for_each_entry(e, head, list) {
318 if (strcmp(e->name, name) == 0)
319 return e;
320 }
321 *error = -ENOENT;
322 mutex_unlock(mutex);
323 return NULL;
324 }
325
326 static void *
327 find_inlist_lock(struct list_head *head, const char *name, const char *prefix,
328 int *error, struct mutex *mutex)
329 {
330 return try_then_request_module(
331 find_inlist_lock_noload(head, name, error, mutex),
332 "%s%s", prefix, name);
333 }
334
335 static inline struct ebt_table *
336 find_table_lock(struct net *net, const char *name, int *error,
337 struct mutex *mutex)
338 {
339 return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name,
340 "ebtable_", error, mutex);
341 }
342
343 static inline void ebt_free_table_info(struct ebt_table_info *info)
344 {
345 int i;
346
347 if (info->chainstack) {
348 for_each_possible_cpu(i)
349 vfree(info->chainstack[i]);
350 vfree(info->chainstack);
351 }
352 }
353 static inline int
354 ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
355 unsigned int *cnt)
356 {
357 const struct ebt_entry *e = par->entryinfo;
358 struct xt_match *match;
359 size_t left = ((char *)e + e->watchers_offset) - (char *)m;
360 int ret;
361
362 if (left < sizeof(struct ebt_entry_match) ||
363 left - sizeof(struct ebt_entry_match) < m->match_size)
364 return -EINVAL;
365
366 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision);
367 if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) {
368 if (!IS_ERR(match))
369 module_put(match->me);
370 request_module("ebt_%s", m->u.name);
371 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision);
372 }
373 if (IS_ERR(match))
374 return PTR_ERR(match);
375 m->u.match = match;
376
377 par->match = match;
378 par->matchinfo = m->data;
379 ret = xt_check_match(par, m->match_size,
380 ntohs(e->ethproto), e->invflags & EBT_IPROTO);
381 if (ret < 0) {
382 module_put(match->me);
383 return ret;
384 }
385
386 (*cnt)++;
387 return 0;
388 }
389
390 static inline int
391 ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
392 unsigned int *cnt)
393 {
394 const struct ebt_entry *e = par->entryinfo;
395 struct xt_target *watcher;
396 size_t left = ((char *)e + e->target_offset) - (char *)w;
397 int ret;
398
399 if (left < sizeof(struct ebt_entry_watcher) ||
400 left - sizeof(struct ebt_entry_watcher) < w->watcher_size)
401 return -EINVAL;
402
403 watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0);
404 if (IS_ERR(watcher))
405 return PTR_ERR(watcher);
406
407 if (watcher->family != NFPROTO_BRIDGE) {
408 module_put(watcher->me);
409 return -ENOENT;
410 }
411
412 w->u.watcher = watcher;
413
414 par->target = watcher;
415 par->targinfo = w->data;
416 ret = xt_check_target(par, w->watcher_size,
417 ntohs(e->ethproto), e->invflags & EBT_IPROTO);
418 if (ret < 0) {
419 module_put(watcher->me);
420 return ret;
421 }
422
423 (*cnt)++;
424 return 0;
425 }
426
427 static int ebt_verify_pointers(const struct ebt_replace *repl,
428 struct ebt_table_info *newinfo)
429 {
430 unsigned int limit = repl->entries_size;
431 unsigned int valid_hooks = repl->valid_hooks;
432 unsigned int offset = 0;
433 int i;
434
435 for (i = 0; i < NF_BR_NUMHOOKS; i++)
436 newinfo->hook_entry[i] = NULL;
437
438 newinfo->entries_size = repl->entries_size;
439 newinfo->nentries = repl->nentries;
440
441 while (offset < limit) {
442 size_t left = limit - offset;
443 struct ebt_entry *e = (void *)newinfo->entries + offset;
444
445 if (left < sizeof(unsigned int))
446 break;
447
448 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
449 if ((valid_hooks & (1 << i)) == 0)
450 continue;
451 if ((char __user *)repl->hook_entry[i] ==
452 repl->entries + offset)
453 break;
454 }
455
456 if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
457 if (e->bitmask != 0) {
458 /* we make userspace set this right,
459 * so there is no misunderstanding
460 */
461 return -EINVAL;
462 }
463 if (i != NF_BR_NUMHOOKS)
464 newinfo->hook_entry[i] = (struct ebt_entries *)e;
465 if (left < sizeof(struct ebt_entries))
466 break;
467 offset += sizeof(struct ebt_entries);
468 } else {
469 if (left < sizeof(struct ebt_entry))
470 break;
471 if (left < e->next_offset)
472 break;
473 if (e->next_offset < sizeof(struct ebt_entry))
474 return -EINVAL;
475 offset += e->next_offset;
476 }
477 }
478 if (offset != limit)
479 return -EINVAL;
480
481 /* check if all valid hooks have a chain */
482 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
483 if (!newinfo->hook_entry[i] &&
484 (valid_hooks & (1 << i)))
485 return -EINVAL;
486 }
487 return 0;
488 }
489
490 /* this one is very careful, as it is the first function
491 * to parse the userspace data
492 */
493 static inline int
494 ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
495 const struct ebt_table_info *newinfo,
496 unsigned int *n, unsigned int *cnt,
497 unsigned int *totalcnt, unsigned int *udc_cnt)
498 {
499 int i;
500
501 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
502 if ((void *)e == (void *)newinfo->hook_entry[i])
503 break;
504 }
505 /* beginning of a new chain
506 * if i == NF_BR_NUMHOOKS it must be a user defined chain
507 */
508 if (i != NF_BR_NUMHOOKS || !e->bitmask) {
509 /* this checks if the previous chain has as many entries
510 * as it said it has
511 */
512 if (*n != *cnt)
513 return -EINVAL;
514
515 if (((struct ebt_entries *)e)->policy != EBT_DROP &&
516 ((struct ebt_entries *)e)->policy != EBT_ACCEPT) {
517 /* only RETURN from udc */
518 if (i != NF_BR_NUMHOOKS ||
519 ((struct ebt_entries *)e)->policy != EBT_RETURN)
520 return -EINVAL;
521 }
522 if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */
523 (*udc_cnt)++;
524 if (((struct ebt_entries *)e)->counter_offset != *totalcnt)
525 return -EINVAL;
526 *n = ((struct ebt_entries *)e)->nentries;
527 *cnt = 0;
528 return 0;
529 }
530 /* a plain old entry, heh */
531 if (sizeof(struct ebt_entry) > e->watchers_offset ||
532 e->watchers_offset > e->target_offset ||
533 e->target_offset >= e->next_offset)
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 return -EINVAL;
539
540 (*cnt)++;
541 (*totalcnt)++;
542 return 0;
543 }
544
545 struct ebt_cl_stack {
546 struct ebt_chainstack cs;
547 int from;
548 unsigned int hookmask;
549 };
550
551 /* We need these positions to check that the jumps to a different part of the
552 * entries is a jump to the beginning of a new chain.
553 */
554 static inline int
555 ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo,
556 unsigned int *n, struct ebt_cl_stack *udc)
557 {
558 int i;
559
560 /* we're only interested in chain starts */
561 if (e->bitmask)
562 return 0;
563 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
564 if (newinfo->hook_entry[i] == (struct ebt_entries *)e)
565 break;
566 }
567 /* only care about udc */
568 if (i != NF_BR_NUMHOOKS)
569 return 0;
570
571 udc[*n].cs.chaininfo = (struct ebt_entries *)e;
572 /* these initialisations are depended on later in check_chainloops() */
573 udc[*n].cs.n = 0;
574 udc[*n].hookmask = 0;
575
576 (*n)++;
577 return 0;
578 }
579
580 static inline int
581 ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i)
582 {
583 struct xt_mtdtor_param par;
584
585 if (i && (*i)-- == 0)
586 return 1;
587
588 par.net = net;
589 par.match = m->u.match;
590 par.matchinfo = m->data;
591 par.family = NFPROTO_BRIDGE;
592 if (par.match->destroy != NULL)
593 par.match->destroy(&par);
594 module_put(par.match->me);
595 return 0;
596 }
597
598 static inline int
599 ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i)
600 {
601 struct xt_tgdtor_param par;
602
603 if (i && (*i)-- == 0)
604 return 1;
605
606 par.net = net;
607 par.target = w->u.watcher;
608 par.targinfo = w->data;
609 par.family = NFPROTO_BRIDGE;
610 if (par.target->destroy != NULL)
611 par.target->destroy(&par);
612 module_put(par.target->me);
613 return 0;
614 }
615
616 static inline int
617 ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
618 {
619 struct xt_tgdtor_param par;
620 struct ebt_entry_target *t;
621
622 if (e->bitmask == 0)
623 return 0;
624 /* we're done */
625 if (cnt && (*cnt)-- == 0)
626 return 1;
627 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL);
628 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL);
629 t = ebt_get_target(e);
630
631 par.net = net;
632 par.target = t->u.target;
633 par.targinfo = t->data;
634 par.family = NFPROTO_BRIDGE;
635 if (par.target->destroy != NULL)
636 par.target->destroy(&par);
637 module_put(par.target->me);
638 return 0;
639 }
640
641 static inline int
642 ebt_check_entry(struct ebt_entry *e, struct net *net,
643 const struct ebt_table_info *newinfo,
644 const char *name, unsigned int *cnt,
645 struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
646 {
647 struct ebt_entry_target *t;
648 struct xt_target *target;
649 unsigned int i, j, hook = 0, hookmask = 0;
650 size_t gap;
651 int ret;
652 struct xt_mtchk_param mtpar;
653 struct xt_tgchk_param tgpar;
654
655 /* don't mess with the struct ebt_entries */
656 if (e->bitmask == 0)
657 return 0;
658
659 if (e->bitmask & ~EBT_F_MASK)
660 return -EINVAL;
661
662 if (e->invflags & ~EBT_INV_MASK)
663 return -EINVAL;
664
665 if ((e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3))
666 return -EINVAL;
667
668 /* what hook do we belong to? */
669 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
670 if (!newinfo->hook_entry[i])
671 continue;
672 if ((char *)newinfo->hook_entry[i] < (char *)e)
673 hook = i;
674 else
675 break;
676 }
677 /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on
678 * a base chain
679 */
680 if (i < NF_BR_NUMHOOKS)
681 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
682 else {
683 for (i = 0; i < udc_cnt; i++)
684 if ((char *)(cl_s[i].cs.chaininfo) > (char *)e)
685 break;
686 if (i == 0)
687 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
688 else
689 hookmask = cl_s[i - 1].hookmask;
690 }
691 i = 0;
692
693 memset(&mtpar, 0, sizeof(mtpar));
694 memset(&tgpar, 0, sizeof(tgpar));
695 mtpar.net = tgpar.net = net;
696 mtpar.table = tgpar.table = name;
697 mtpar.entryinfo = tgpar.entryinfo = e;
698 mtpar.hook_mask = tgpar.hook_mask = hookmask;
699 mtpar.family = tgpar.family = NFPROTO_BRIDGE;
700 ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i);
701 if (ret != 0)
702 goto cleanup_matches;
703 j = 0;
704 ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j);
705 if (ret != 0)
706 goto cleanup_watchers;
707 t = ebt_get_target(e);
708 gap = e->next_offset - e->target_offset;
709
710 target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0);
711 if (IS_ERR(target)) {
712 ret = PTR_ERR(target);
713 goto cleanup_watchers;
714 }
715
716 /* Reject UNSPEC, xtables verdicts/return values are incompatible */
717 if (target->family != NFPROTO_BRIDGE) {
718 module_put(target->me);
719 ret = -ENOENT;
720 goto cleanup_watchers;
721 }
722
723 t->u.target = target;
724 if (t->u.target == &ebt_standard_target) {
725 if (gap < sizeof(struct ebt_standard_target)) {
726 ret = -EFAULT;
727 goto cleanup_watchers;
728 }
729 if (((struct ebt_standard_target *)t)->verdict <
730 -NUM_STANDARD_TARGETS) {
731 ret = -EFAULT;
732 goto cleanup_watchers;
733 }
734 } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) {
735 module_put(t->u.target->me);
736 ret = -EFAULT;
737 goto cleanup_watchers;
738 }
739
740 tgpar.target = target;
741 tgpar.targinfo = t->data;
742 ret = xt_check_target(&tgpar, t->target_size,
743 ntohs(e->ethproto), e->invflags & EBT_IPROTO);
744 if (ret < 0) {
745 module_put(target->me);
746 goto cleanup_watchers;
747 }
748 (*cnt)++;
749 return 0;
750 cleanup_watchers:
751 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j);
752 cleanup_matches:
753 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i);
754 return ret;
755 }
756
757 /* checks for loops and sets the hook mask for udc
758 * the hook mask for udc tells us from which base chains the udc can be
759 * accessed. This mask is a parameter to the check() functions of the extensions
760 */
761 static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
762 unsigned int udc_cnt, unsigned int hooknr, char *base)
763 {
764 int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
765 const struct ebt_entry *e = (struct ebt_entry *)chain->data;
766 const struct ebt_entry_target *t;
767
768 while (pos < nentries || chain_nr != -1) {
769 /* end of udc, go back one 'recursion' step */
770 if (pos == nentries) {
771 /* put back values of the time when this chain was called */
772 e = cl_s[chain_nr].cs.e;
773 if (cl_s[chain_nr].from != -1)
774 nentries =
775 cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries;
776 else
777 nentries = chain->nentries;
778 pos = cl_s[chain_nr].cs.n;
779 /* make sure we won't see a loop that isn't one */
780 cl_s[chain_nr].cs.n = 0;
781 chain_nr = cl_s[chain_nr].from;
782 if (pos == nentries)
783 continue;
784 }
785 t = ebt_get_target_c(e);
786 if (strcmp(t->u.name, EBT_STANDARD_TARGET))
787 goto letscontinue;
788 if (e->target_offset + sizeof(struct ebt_standard_target) >
789 e->next_offset)
790 return -1;
791
792 verdict = ((struct ebt_standard_target *)t)->verdict;
793 if (verdict >= 0) { /* jump to another chain */
794 struct ebt_entries *hlp2 =
795 (struct ebt_entries *)(base + verdict);
796 for (i = 0; i < udc_cnt; i++)
797 if (hlp2 == cl_s[i].cs.chaininfo)
798 break;
799 /* bad destination or loop */
800 if (i == udc_cnt)
801 return -1;
802
803 if (cl_s[i].cs.n)
804 return -1;
805
806 if (cl_s[i].hookmask & (1 << hooknr))
807 goto letscontinue;
808 /* this can't be 0, so the loop test is correct */
809 cl_s[i].cs.n = pos + 1;
810 pos = 0;
811 cl_s[i].cs.e = ebt_next_entry(e);
812 e = (struct ebt_entry *)(hlp2->data);
813 nentries = hlp2->nentries;
814 cl_s[i].from = chain_nr;
815 chain_nr = i;
816 /* this udc is accessible from the base chain for hooknr */
817 cl_s[i].hookmask |= (1 << hooknr);
818 continue;
819 }
820 letscontinue:
821 e = ebt_next_entry(e);
822 pos++;
823 }
824 return 0;
825 }
826
827 /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
828 static int translate_table(struct net *net, const char *name,
829 struct ebt_table_info *newinfo)
830 {
831 unsigned int i, j, k, udc_cnt;
832 int ret;
833 struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */
834
835 i = 0;
836 while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i])
837 i++;
838 if (i == NF_BR_NUMHOOKS)
839 return -EINVAL;
840
841 if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries)
842 return -EINVAL;
843
844 /* make sure chains are ordered after each other in same order
845 * as their corresponding hooks
846 */
847 for (j = i + 1; j < NF_BR_NUMHOOKS; j++) {
848 if (!newinfo->hook_entry[j])
849 continue;
850 if (newinfo->hook_entry[j] <= newinfo->hook_entry[i])
851 return -EINVAL;
852
853 i = j;
854 }
855
856 /* do some early checkings and initialize some things */
857 i = 0; /* holds the expected nr. of entries for the chain */
858 j = 0; /* holds the up to now counted entries for the chain */
859 k = 0; /* holds the total nr. of entries, should equal
860 * newinfo->nentries afterwards
861 */
862 udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */
863 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
864 ebt_check_entry_size_and_hooks, newinfo,
865 &i, &j, &k, &udc_cnt);
866
867 if (ret != 0)
868 return ret;
869
870 if (i != j)
871 return -EINVAL;
872
873 if (k != newinfo->nentries)
874 return -EINVAL;
875
876 /* get the location of the udc, put them in an array
877 * while we're at it, allocate the chainstack
878 */
879 if (udc_cnt) {
880 /* this will get free'd in do_replace()/ebt_register_table()
881 * if an error occurs
882 */
883 newinfo->chainstack =
884 vmalloc(array_size(nr_cpu_ids,
885 sizeof(*(newinfo->chainstack))));
886 if (!newinfo->chainstack)
887 return -ENOMEM;
888 for_each_possible_cpu(i) {
889 newinfo->chainstack[i] =
890 vmalloc(array_size(udc_cnt, sizeof(*(newinfo->chainstack[0]))));
891 if (!newinfo->chainstack[i]) {
892 while (i)
893 vfree(newinfo->chainstack[--i]);
894 vfree(newinfo->chainstack);
895 newinfo->chainstack = NULL;
896 return -ENOMEM;
897 }
898 }
899
900 cl_s = vmalloc(array_size(udc_cnt, sizeof(*cl_s)));
901 if (!cl_s)
902 return -ENOMEM;
903 i = 0; /* the i'th udc */
904 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
905 ebt_get_udc_positions, newinfo, &i, cl_s);
906 /* sanity check */
907 if (i != udc_cnt) {
908 vfree(cl_s);
909 return -EFAULT;
910 }
911 }
912
913 /* Check for loops */
914 for (i = 0; i < NF_BR_NUMHOOKS; i++)
915 if (newinfo->hook_entry[i])
916 if (check_chainloops(newinfo->hook_entry[i],
917 cl_s, udc_cnt, i, newinfo->entries)) {
918 vfree(cl_s);
919 return -EINVAL;
920 }
921
922 /* we now know the following (along with E=mc²):
923 * - the nr of entries in each chain is right
924 * - the size of the allocated space is right
925 * - all valid hooks have a corresponding chain
926 * - there are no loops
927 * - wrong data can still be on the level of a single entry
928 * - could be there are jumps to places that are not the
929 * beginning of a chain. This can only occur in chains that
930 * are not accessible from any base chains, so we don't care.
931 */
932
933 /* used to know what we need to clean up if something goes wrong */
934 i = 0;
935 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
936 ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt);
937 if (ret != 0) {
938 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
939 ebt_cleanup_entry, net, &i);
940 }
941 vfree(cl_s);
942 return ret;
943 }
944
945 /* called under write_lock */
946 static void get_counters(const struct ebt_counter *oldcounters,
947 struct ebt_counter *counters, unsigned int nentries)
948 {
949 int i, cpu;
950 struct ebt_counter *counter_base;
951
952 /* counters of cpu 0 */
953 memcpy(counters, oldcounters,
954 sizeof(struct ebt_counter) * nentries);
955
956 /* add other counters to those of cpu 0 */
957 for_each_possible_cpu(cpu) {
958 if (cpu == 0)
959 continue;
960 counter_base = COUNTER_BASE(oldcounters, nentries, cpu);
961 for (i = 0; i < nentries; i++)
962 ADD_COUNTER(counters[i], counter_base[i].bcnt,
963 counter_base[i].pcnt);
964 }
965 }
966
967 static int do_replace_finish(struct net *net, struct ebt_replace *repl,
968 struct ebt_table_info *newinfo)
969 {
970 int ret;
971 struct ebt_counter *counterstmp = NULL;
972 /* used to be able to unlock earlier */
973 struct ebt_table_info *table;
974 struct ebt_table *t;
975
976 /* the user wants counters back
977 * the check on the size is done later, when we have the lock
978 */
979 if (repl->num_counters) {
980 unsigned long size = repl->num_counters * sizeof(*counterstmp);
981 counterstmp = vmalloc(size);
982 if (!counterstmp)
983 return -ENOMEM;
984 }
985
986 newinfo->chainstack = NULL;
987 ret = ebt_verify_pointers(repl, newinfo);
988 if (ret != 0)
989 goto free_counterstmp;
990
991 ret = translate_table(net, repl->name, newinfo);
992
993 if (ret != 0)
994 goto free_counterstmp;
995
996 t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
997 if (!t) {
998 ret = -ENOENT;
999 goto free_iterate;
1000 }
1001
1002 /* the table doesn't like it */
1003 if (t->check && (ret = t->check(newinfo, repl->valid_hooks)))
1004 goto free_unlock;
1005
1006 if (repl->num_counters && repl->num_counters != t->private->nentries) {
1007 ret = -EINVAL;
1008 goto free_unlock;
1009 }
1010
1011 /* we have the mutex lock, so no danger in reading this pointer */
1012 table = t->private;
1013 /* make sure the table can only be rmmod'ed if it contains no rules */
1014 if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) {
1015 ret = -ENOENT;
1016 goto free_unlock;
1017 } else if (table->nentries && !newinfo->nentries)
1018 module_put(t->me);
1019 /* we need an atomic snapshot of the counters */
1020 write_lock_bh(&t->lock);
1021 if (repl->num_counters)
1022 get_counters(t->private->counters, counterstmp,
1023 t->private->nentries);
1024
1025 t->private = newinfo;
1026 write_unlock_bh(&t->lock);
1027 mutex_unlock(&ebt_mutex);
1028 /* so, a user can change the chains while having messed up her counter
1029 * allocation. Only reason why this is done is because this way the lock
1030 * is held only once, while this doesn't bring the kernel into a
1031 * dangerous state.
1032 */
1033 if (repl->num_counters &&
1034 copy_to_user(repl->counters, counterstmp,
1035 repl->num_counters * sizeof(struct ebt_counter))) {
1036 /* Silent error, can't fail, new table is already in place */
1037 net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n");
1038 }
1039
1040 /* decrease module count and free resources */
1041 EBT_ENTRY_ITERATE(table->entries, table->entries_size,
1042 ebt_cleanup_entry, net, NULL);
1043
1044 vfree(table->entries);
1045 ebt_free_table_info(table);
1046 vfree(table);
1047 vfree(counterstmp);
1048
1049 #ifdef CONFIG_AUDIT
1050 if (audit_enabled) {
1051 audit_log(audit_context(), GFP_KERNEL,
1052 AUDIT_NETFILTER_CFG,
1053 "table=%s family=%u entries=%u",
1054 repl->name, AF_BRIDGE, repl->nentries);
1055 }
1056 #endif
1057 return ret;
1058
1059 free_unlock:
1060 mutex_unlock(&ebt_mutex);
1061 free_iterate:
1062 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
1063 ebt_cleanup_entry, net, NULL);
1064 free_counterstmp:
1065 vfree(counterstmp);
1066 /* can be initialized in translate_table() */
1067 ebt_free_table_info(newinfo);
1068 return ret;
1069 }
1070
1071 /* replace the table */
1072 static int do_replace(struct net *net, const void __user *user,
1073 unsigned int len)
1074 {
1075 int ret, countersize;
1076 struct ebt_table_info *newinfo;
1077 struct ebt_replace tmp;
1078
1079 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1080 return -EFAULT;
1081
1082 if (len != sizeof(tmp) + tmp.entries_size)
1083 return -EINVAL;
1084
1085 if (tmp.entries_size == 0)
1086 return -EINVAL;
1087
1088 /* overflow check */
1089 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
1090 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
1091 return -ENOMEM;
1092 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
1093 return -ENOMEM;
1094
1095 tmp.name[sizeof(tmp.name) - 1] = 0;
1096
1097 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
1098 newinfo = __vmalloc(sizeof(*newinfo) + countersize, GFP_KERNEL_ACCOUNT,
1099 PAGE_KERNEL);
1100 if (!newinfo)
1101 return -ENOMEM;
1102
1103 if (countersize)
1104 memset(newinfo->counters, 0, countersize);
1105
1106 newinfo->entries = __vmalloc(tmp.entries_size, GFP_KERNEL_ACCOUNT,
1107 PAGE_KERNEL);
1108 if (!newinfo->entries) {
1109 ret = -ENOMEM;
1110 goto free_newinfo;
1111 }
1112 if (copy_from_user(
1113 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
1114 ret = -EFAULT;
1115 goto free_entries;
1116 }
1117
1118 ret = do_replace_finish(net, &tmp, newinfo);
1119 if (ret == 0)
1120 return ret;
1121 free_entries:
1122 vfree(newinfo->entries);
1123 free_newinfo:
1124 vfree(newinfo);
1125 return ret;
1126 }
1127
1128 static void __ebt_unregister_table(struct net *net, struct ebt_table *table)
1129 {
1130 mutex_lock(&ebt_mutex);
1131 list_del(&table->list);
1132 mutex_unlock(&ebt_mutex);
1133 EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
1134 ebt_cleanup_entry, net, NULL);
1135 if (table->private->nentries)
1136 module_put(table->me);
1137 vfree(table->private->entries);
1138 ebt_free_table_info(table->private);
1139 vfree(table->private);
1140 kfree(table);
1141 }
1142
1143 int ebt_register_table(struct net *net, const struct ebt_table *input_table,
1144 const struct nf_hook_ops *ops, struct ebt_table **res)
1145 {
1146 struct ebt_table_info *newinfo;
1147 struct ebt_table *t, *table;
1148 struct ebt_replace_kernel *repl;
1149 int ret, i, countersize;
1150 void *p;
1151
1152 if (input_table == NULL || (repl = input_table->table) == NULL ||
1153 repl->entries == NULL || repl->entries_size == 0 ||
1154 repl->counters != NULL || input_table->private != NULL)
1155 return -EINVAL;
1156
1157 /* Don't add one table to multiple lists. */
1158 table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL);
1159 if (!table) {
1160 ret = -ENOMEM;
1161 goto out;
1162 }
1163
1164 countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
1165 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1166 ret = -ENOMEM;
1167 if (!newinfo)
1168 goto free_table;
1169
1170 p = vmalloc(repl->entries_size);
1171 if (!p)
1172 goto free_newinfo;
1173
1174 memcpy(p, repl->entries, repl->entries_size);
1175 newinfo->entries = p;
1176
1177 newinfo->entries_size = repl->entries_size;
1178 newinfo->nentries = repl->nentries;
1179
1180 if (countersize)
1181 memset(newinfo->counters, 0, countersize);
1182
1183 /* fill in newinfo and parse the entries */
1184 newinfo->chainstack = NULL;
1185 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1186 if ((repl->valid_hooks & (1 << i)) == 0)
1187 newinfo->hook_entry[i] = NULL;
1188 else
1189 newinfo->hook_entry[i] = p +
1190 ((char *)repl->hook_entry[i] - repl->entries);
1191 }
1192 ret = translate_table(net, repl->name, newinfo);
1193 if (ret != 0)
1194 goto free_chainstack;
1195
1196 if (table->check && table->check(newinfo, table->valid_hooks)) {
1197 ret = -EINVAL;
1198 goto free_chainstack;
1199 }
1200
1201 table->private = newinfo;
1202 rwlock_init(&table->lock);
1203 mutex_lock(&ebt_mutex);
1204 list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
1205 if (strcmp(t->name, table->name) == 0) {
1206 ret = -EEXIST;
1207 goto free_unlock;
1208 }
1209 }
1210
1211 /* Hold a reference count if the chains aren't empty */
1212 if (newinfo->nentries && !try_module_get(table->me)) {
1213 ret = -ENOENT;
1214 goto free_unlock;
1215 }
1216 list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
1217 mutex_unlock(&ebt_mutex);
1218
1219 WRITE_ONCE(*res, table);
1220 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
1221 if (ret) {
1222 __ebt_unregister_table(net, table);
1223 *res = NULL;
1224 }
1225
1226 return ret;
1227 free_unlock:
1228 mutex_unlock(&ebt_mutex);
1229 free_chainstack:
1230 ebt_free_table_info(newinfo);
1231 vfree(newinfo->entries);
1232 free_newinfo:
1233 vfree(newinfo);
1234 free_table:
1235 kfree(table);
1236 out:
1237 return ret;
1238 }
1239
1240 void ebt_unregister_table(struct net *net, struct ebt_table *table,
1241 const struct nf_hook_ops *ops)
1242 {
1243 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
1244 __ebt_unregister_table(net, table);
1245 }
1246
1247 /* userspace just supplied us with counters */
1248 static int do_update_counters(struct net *net, const char *name,
1249 struct ebt_counter __user *counters,
1250 unsigned int num_counters,
1251 const void __user *user, unsigned int len)
1252 {
1253 int i, ret;
1254 struct ebt_counter *tmp;
1255 struct ebt_table *t;
1256
1257 if (num_counters == 0)
1258 return -EINVAL;
1259
1260 tmp = vmalloc(array_size(num_counters, sizeof(*tmp)));
1261 if (!tmp)
1262 return -ENOMEM;
1263
1264 t = find_table_lock(net, name, &ret, &ebt_mutex);
1265 if (!t)
1266 goto free_tmp;
1267
1268 if (num_counters != t->private->nentries) {
1269 ret = -EINVAL;
1270 goto unlock_mutex;
1271 }
1272
1273 if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) {
1274 ret = -EFAULT;
1275 goto unlock_mutex;
1276 }
1277
1278 /* we want an atomic add of the counters */
1279 write_lock_bh(&t->lock);
1280
1281 /* we add to the counters of the first cpu */
1282 for (i = 0; i < num_counters; i++)
1283 ADD_COUNTER(t->private->counters[i], tmp[i].bcnt, tmp[i].pcnt);
1284
1285 write_unlock_bh(&t->lock);
1286 ret = 0;
1287 unlock_mutex:
1288 mutex_unlock(&ebt_mutex);
1289 free_tmp:
1290 vfree(tmp);
1291 return ret;
1292 }
1293
1294 static int update_counters(struct net *net, const void __user *user,
1295 unsigned int len)
1296 {
1297 struct ebt_replace hlp;
1298
1299 if (copy_from_user(&hlp, user, sizeof(hlp)))
1300 return -EFAULT;
1301
1302 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
1303 return -EINVAL;
1304
1305 return do_update_counters(net, hlp.name, hlp.counters,
1306 hlp.num_counters, user, len);
1307 }
1308
1309 static inline int ebt_obj_to_user(char __user *um, const char *_name,
1310 const char *data, int entrysize,
1311 int usersize, int datasize, u8 revision)
1312 {
1313 char name[EBT_EXTENSION_MAXNAMELEN] = {0};
1314
1315 /* ebtables expects 31 bytes long names but xt_match names are 29 bytes
1316 * long. Copy 29 bytes and fill remaining bytes with zeroes.
1317 */
1318 strlcpy(name, _name, sizeof(name));
1319 if (copy_to_user(um, name, EBT_EXTENSION_MAXNAMELEN) ||
1320 put_user(revision, (u8 __user *)(um + EBT_EXTENSION_MAXNAMELEN)) ||
1321 put_user(datasize, (int __user *)(um + EBT_EXTENSION_MAXNAMELEN + 1)) ||
1322 xt_data_to_user(um + entrysize, data, usersize, datasize,
1323 XT_ALIGN(datasize)))
1324 return -EFAULT;
1325
1326 return 0;
1327 }
1328
1329 static inline int ebt_match_to_user(const struct ebt_entry_match *m,
1330 const char *base, char __user *ubase)
1331 {
1332 return ebt_obj_to_user(ubase + ((char *)m - base),
1333 m->u.match->name, m->data, sizeof(*m),
1334 m->u.match->usersize, m->match_size,
1335 m->u.match->revision);
1336 }
1337
1338 static inline int ebt_watcher_to_user(const struct ebt_entry_watcher *w,
1339 const char *base, char __user *ubase)
1340 {
1341 return ebt_obj_to_user(ubase + ((char *)w - base),
1342 w->u.watcher->name, w->data, sizeof(*w),
1343 w->u.watcher->usersize, w->watcher_size,
1344 w->u.watcher->revision);
1345 }
1346
1347 static inline int ebt_entry_to_user(struct ebt_entry *e, const char *base,
1348 char __user *ubase)
1349 {
1350 int ret;
1351 char __user *hlp;
1352 const struct ebt_entry_target *t;
1353
1354 if (e->bitmask == 0) {
1355 /* special case !EBT_ENTRY_OR_ENTRIES */
1356 if (copy_to_user(ubase + ((char *)e - base), e,
1357 sizeof(struct ebt_entries)))
1358 return -EFAULT;
1359 return 0;
1360 }
1361
1362 if (copy_to_user(ubase + ((char *)e - base), e, sizeof(*e)))
1363 return -EFAULT;
1364
1365 hlp = ubase + (((char *)e + e->target_offset) - base);
1366 t = ebt_get_target_c(e);
1367
1368 ret = EBT_MATCH_ITERATE(e, ebt_match_to_user, base, ubase);
1369 if (ret != 0)
1370 return ret;
1371 ret = EBT_WATCHER_ITERATE(e, ebt_watcher_to_user, base, ubase);
1372 if (ret != 0)
1373 return ret;
1374 ret = ebt_obj_to_user(hlp, t->u.target->name, t->data, sizeof(*t),
1375 t->u.target->usersize, t->target_size,
1376 t->u.target->revision);
1377 if (ret != 0)
1378 return ret;
1379
1380 return 0;
1381 }
1382
1383 static int copy_counters_to_user(struct ebt_table *t,
1384 const struct ebt_counter *oldcounters,
1385 void __user *user, unsigned int num_counters,
1386 unsigned int nentries)
1387 {
1388 struct ebt_counter *counterstmp;
1389 int ret = 0;
1390
1391 /* userspace might not need the counters */
1392 if (num_counters == 0)
1393 return 0;
1394
1395 if (num_counters != nentries)
1396 return -EINVAL;
1397
1398 counterstmp = vmalloc(array_size(nentries, sizeof(*counterstmp)));
1399 if (!counterstmp)
1400 return -ENOMEM;
1401
1402 write_lock_bh(&t->lock);
1403 get_counters(oldcounters, counterstmp, nentries);
1404 write_unlock_bh(&t->lock);
1405
1406 if (copy_to_user(user, counterstmp,
1407 nentries * sizeof(struct ebt_counter)))
1408 ret = -EFAULT;
1409 vfree(counterstmp);
1410 return ret;
1411 }
1412
1413 /* called with ebt_mutex locked */
1414 static int copy_everything_to_user(struct ebt_table *t, void __user *user,
1415 const int *len, int cmd)
1416 {
1417 struct ebt_replace tmp;
1418 const struct ebt_counter *oldcounters;
1419 unsigned int entries_size, nentries;
1420 int ret;
1421 char *entries;
1422
1423 if (cmd == EBT_SO_GET_ENTRIES) {
1424 entries_size = t->private->entries_size;
1425 nentries = t->private->nentries;
1426 entries = t->private->entries;
1427 oldcounters = t->private->counters;
1428 } else {
1429 entries_size = t->table->entries_size;
1430 nentries = t->table->nentries;
1431 entries = t->table->entries;
1432 oldcounters = t->table->counters;
1433 }
1434
1435 if (copy_from_user(&tmp, user, sizeof(tmp)))
1436 return -EFAULT;
1437
1438 if (*len != sizeof(struct ebt_replace) + entries_size +
1439 (tmp.num_counters ? nentries * sizeof(struct ebt_counter) : 0))
1440 return -EINVAL;
1441
1442 if (tmp.nentries != nentries)
1443 return -EINVAL;
1444
1445 if (tmp.entries_size != entries_size)
1446 return -EINVAL;
1447
1448 ret = copy_counters_to_user(t, oldcounters, tmp.counters,
1449 tmp.num_counters, nentries);
1450 if (ret)
1451 return ret;
1452
1453 /* set the match/watcher/target names right */
1454 return EBT_ENTRY_ITERATE(entries, entries_size,
1455 ebt_entry_to_user, entries, tmp.entries);
1456 }
1457
1458 static int do_ebt_set_ctl(struct sock *sk,
1459 int cmd, void __user *user, unsigned int len)
1460 {
1461 int ret;
1462 struct net *net = sock_net(sk);
1463
1464 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1465 return -EPERM;
1466
1467 switch (cmd) {
1468 case EBT_SO_SET_ENTRIES:
1469 ret = do_replace(net, user, len);
1470 break;
1471 case EBT_SO_SET_COUNTERS:
1472 ret = update_counters(net, user, len);
1473 break;
1474 default:
1475 ret = -EINVAL;
1476 }
1477 return ret;
1478 }
1479
1480 static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1481 {
1482 int ret;
1483 struct ebt_replace tmp;
1484 struct ebt_table *t;
1485 struct net *net = sock_net(sk);
1486
1487 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1488 return -EPERM;
1489
1490 if (copy_from_user(&tmp, user, sizeof(tmp)))
1491 return -EFAULT;
1492
1493 tmp.name[sizeof(tmp.name) - 1] = '\0';
1494
1495 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
1496 if (!t)
1497 return ret;
1498
1499 switch (cmd) {
1500 case EBT_SO_GET_INFO:
1501 case EBT_SO_GET_INIT_INFO:
1502 if (*len != sizeof(struct ebt_replace)) {
1503 ret = -EINVAL;
1504 mutex_unlock(&ebt_mutex);
1505 break;
1506 }
1507 if (cmd == EBT_SO_GET_INFO) {
1508 tmp.nentries = t->private->nentries;
1509 tmp.entries_size = t->private->entries_size;
1510 tmp.valid_hooks = t->valid_hooks;
1511 } else {
1512 tmp.nentries = t->table->nentries;
1513 tmp.entries_size = t->table->entries_size;
1514 tmp.valid_hooks = t->table->valid_hooks;
1515 }
1516 mutex_unlock(&ebt_mutex);
1517 if (copy_to_user(user, &tmp, *len) != 0) {
1518 ret = -EFAULT;
1519 break;
1520 }
1521 ret = 0;
1522 break;
1523
1524 case EBT_SO_GET_ENTRIES:
1525 case EBT_SO_GET_INIT_ENTRIES:
1526 ret = copy_everything_to_user(t, user, len, cmd);
1527 mutex_unlock(&ebt_mutex);
1528 break;
1529
1530 default:
1531 mutex_unlock(&ebt_mutex);
1532 ret = -EINVAL;
1533 }
1534
1535 return ret;
1536 }
1537
1538 #ifdef CONFIG_COMPAT
1539 /* 32 bit-userspace compatibility definitions. */
1540 struct compat_ebt_replace {
1541 char name[EBT_TABLE_MAXNAMELEN];
1542 compat_uint_t valid_hooks;
1543 compat_uint_t nentries;
1544 compat_uint_t entries_size;
1545 /* start of the chains */
1546 compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
1547 /* nr of counters userspace expects back */
1548 compat_uint_t num_counters;
1549 /* where the kernel will put the old counters. */
1550 compat_uptr_t counters;
1551 compat_uptr_t entries;
1552 };
1553
1554 /* struct ebt_entry_match, _target and _watcher have same layout */
1555 struct compat_ebt_entry_mwt {
1556 union {
1557 struct {
1558 char name[EBT_EXTENSION_MAXNAMELEN];
1559 u8 revision;
1560 };
1561 compat_uptr_t ptr;
1562 } u;
1563 compat_uint_t match_size;
1564 compat_uint_t data[0] __attribute__ ((aligned (__alignof__(struct compat_ebt_replace))));
1565 };
1566
1567 /* account for possible padding between match_size and ->data */
1568 static int ebt_compat_entry_padsize(void)
1569 {
1570 BUILD_BUG_ON(sizeof(struct ebt_entry_match) <
1571 sizeof(struct compat_ebt_entry_mwt));
1572 return (int) sizeof(struct ebt_entry_match) -
1573 sizeof(struct compat_ebt_entry_mwt);
1574 }
1575
1576 static int ebt_compat_match_offset(const struct xt_match *match,
1577 unsigned int userlen)
1578 {
1579 /* ebt_among needs special handling. The kernel .matchsize is
1580 * set to -1 at registration time; at runtime an EBT_ALIGN()ed
1581 * value is expected.
1582 * Example: userspace sends 4500, ebt_among.c wants 4504.
1583 */
1584 if (unlikely(match->matchsize == -1))
1585 return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
1586 return xt_compat_match_offset(match);
1587 }
1588
1589 static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
1590 unsigned int *size)
1591 {
1592 const struct xt_match *match = m->u.match;
1593 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1594 int off = ebt_compat_match_offset(match, m->match_size);
1595 compat_uint_t msize = m->match_size - off;
1596
1597 if (WARN_ON(off >= m->match_size))
1598 return -EINVAL;
1599
1600 if (copy_to_user(cm->u.name, match->name, strlen(match->name) + 1) ||
1601 put_user(match->revision, &cm->u.revision) ||
1602 put_user(msize, &cm->match_size))
1603 return -EFAULT;
1604
1605 if (match->compat_to_user) {
1606 if (match->compat_to_user(cm->data, m->data))
1607 return -EFAULT;
1608 } else {
1609 if (xt_data_to_user(cm->data, m->data, match->usersize, msize,
1610 COMPAT_XT_ALIGN(msize)))
1611 return -EFAULT;
1612 }
1613
1614 *size -= ebt_compat_entry_padsize() + off;
1615 *dstptr = cm->data;
1616 *dstptr += msize;
1617 return 0;
1618 }
1619
1620 static int compat_target_to_user(struct ebt_entry_target *t,
1621 void __user **dstptr,
1622 unsigned int *size)
1623 {
1624 const struct xt_target *target = t->u.target;
1625 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1626 int off = xt_compat_target_offset(target);
1627 compat_uint_t tsize = t->target_size - off;
1628
1629 if (WARN_ON(off >= t->target_size))
1630 return -EINVAL;
1631
1632 if (copy_to_user(cm->u.name, target->name, strlen(target->name) + 1) ||
1633 put_user(target->revision, &cm->u.revision) ||
1634 put_user(tsize, &cm->match_size))
1635 return -EFAULT;
1636
1637 if (target->compat_to_user) {
1638 if (target->compat_to_user(cm->data, t->data))
1639 return -EFAULT;
1640 } else {
1641 if (xt_data_to_user(cm->data, t->data, target->usersize, tsize,
1642 COMPAT_XT_ALIGN(tsize)))
1643 return -EFAULT;
1644 }
1645
1646 *size -= ebt_compat_entry_padsize() + off;
1647 *dstptr = cm->data;
1648 *dstptr += tsize;
1649 return 0;
1650 }
1651
1652 static int compat_watcher_to_user(struct ebt_entry_watcher *w,
1653 void __user **dstptr,
1654 unsigned int *size)
1655 {
1656 return compat_target_to_user((struct ebt_entry_target *)w,
1657 dstptr, size);
1658 }
1659
1660 static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
1661 unsigned int *size)
1662 {
1663 struct ebt_entry_target *t;
1664 struct ebt_entry __user *ce;
1665 u32 watchers_offset, target_offset, next_offset;
1666 compat_uint_t origsize;
1667 int ret;
1668
1669 if (e->bitmask == 0) {
1670 if (*size < sizeof(struct ebt_entries))
1671 return -EINVAL;
1672 if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries)))
1673 return -EFAULT;
1674
1675 *dstptr += sizeof(struct ebt_entries);
1676 *size -= sizeof(struct ebt_entries);
1677 return 0;
1678 }
1679
1680 if (*size < sizeof(*ce))
1681 return -EINVAL;
1682
1683 ce = *dstptr;
1684 if (copy_to_user(ce, e, sizeof(*ce)))
1685 return -EFAULT;
1686
1687 origsize = *size;
1688 *dstptr += sizeof(*ce);
1689
1690 ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
1691 if (ret)
1692 return ret;
1693 watchers_offset = e->watchers_offset - (origsize - *size);
1694
1695 ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
1696 if (ret)
1697 return ret;
1698 target_offset = e->target_offset - (origsize - *size);
1699
1700 t = ebt_get_target(e);
1701
1702 ret = compat_target_to_user(t, dstptr, size);
1703 if (ret)
1704 return ret;
1705 next_offset = e->next_offset - (origsize - *size);
1706
1707 if (put_user(watchers_offset, &ce->watchers_offset) ||
1708 put_user(target_offset, &ce->target_offset) ||
1709 put_user(next_offset, &ce->next_offset))
1710 return -EFAULT;
1711
1712 *size -= sizeof(*ce);
1713 return 0;
1714 }
1715
1716 static int compat_calc_match(struct ebt_entry_match *m, int *off)
1717 {
1718 *off += ebt_compat_match_offset(m->u.match, m->match_size);
1719 *off += ebt_compat_entry_padsize();
1720 return 0;
1721 }
1722
1723 static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
1724 {
1725 *off += xt_compat_target_offset(w->u.watcher);
1726 *off += ebt_compat_entry_padsize();
1727 return 0;
1728 }
1729
1730 static int compat_calc_entry(const struct ebt_entry *e,
1731 const struct ebt_table_info *info,
1732 const void *base,
1733 struct compat_ebt_replace *newinfo)
1734 {
1735 const struct ebt_entry_target *t;
1736 unsigned int entry_offset;
1737 int off, ret, i;
1738
1739 if (e->bitmask == 0)
1740 return 0;
1741
1742 off = 0;
1743 entry_offset = (void *)e - base;
1744
1745 EBT_MATCH_ITERATE(e, compat_calc_match, &off);
1746 EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
1747
1748 t = ebt_get_target_c(e);
1749
1750 off += xt_compat_target_offset(t->u.target);
1751 off += ebt_compat_entry_padsize();
1752
1753 newinfo->entries_size -= off;
1754
1755 ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off);
1756 if (ret)
1757 return ret;
1758
1759 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1760 const void *hookptr = info->hook_entry[i];
1761 if (info->hook_entry[i] &&
1762 (e < (struct ebt_entry *)(base - hookptr))) {
1763 newinfo->hook_entry[i] -= off;
1764 pr_debug("0x%08X -> 0x%08X\n",
1765 newinfo->hook_entry[i] + off,
1766 newinfo->hook_entry[i]);
1767 }
1768 }
1769
1770 return 0;
1771 }
1772
1773 static int ebt_compat_init_offsets(unsigned int number)
1774 {
1775 if (number > INT_MAX)
1776 return -EINVAL;
1777
1778 /* also count the base chain policies */
1779 number += NF_BR_NUMHOOKS;
1780
1781 return xt_compat_init_offsets(NFPROTO_BRIDGE, number);
1782 }
1783
1784 static int compat_table_info(const struct ebt_table_info *info,
1785 struct compat_ebt_replace *newinfo)
1786 {
1787 unsigned int size = info->entries_size;
1788 const void *entries = info->entries;
1789 int ret;
1790
1791 newinfo->entries_size = size;
1792 ret = ebt_compat_init_offsets(info->nentries);
1793 if (ret)
1794 return ret;
1795
1796 return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
1797 entries, newinfo);
1798 }
1799
1800 static int compat_copy_everything_to_user(struct ebt_table *t,
1801 void __user *user, int *len, int cmd)
1802 {
1803 struct compat_ebt_replace repl, tmp;
1804 struct ebt_counter *oldcounters;
1805 struct ebt_table_info tinfo;
1806 int ret;
1807 void __user *pos;
1808
1809 memset(&tinfo, 0, sizeof(tinfo));
1810
1811 if (cmd == EBT_SO_GET_ENTRIES) {
1812 tinfo.entries_size = t->private->entries_size;
1813 tinfo.nentries = t->private->nentries;
1814 tinfo.entries = t->private->entries;
1815 oldcounters = t->private->counters;
1816 } else {
1817 tinfo.entries_size = t->table->entries_size;
1818 tinfo.nentries = t->table->nentries;
1819 tinfo.entries = t->table->entries;
1820 oldcounters = t->table->counters;
1821 }
1822
1823 if (copy_from_user(&tmp, user, sizeof(tmp)))
1824 return -EFAULT;
1825
1826 if (tmp.nentries != tinfo.nentries ||
1827 (tmp.num_counters && tmp.num_counters != tinfo.nentries))
1828 return -EINVAL;
1829
1830 memcpy(&repl, &tmp, sizeof(repl));
1831 if (cmd == EBT_SO_GET_ENTRIES)
1832 ret = compat_table_info(t->private, &repl);
1833 else
1834 ret = compat_table_info(&tinfo, &repl);
1835 if (ret)
1836 return ret;
1837
1838 if (*len != sizeof(tmp) + repl.entries_size +
1839 (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
1840 pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
1841 *len, tinfo.entries_size, repl.entries_size);
1842 return -EINVAL;
1843 }
1844
1845 /* userspace might not need the counters */
1846 ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters),
1847 tmp.num_counters, tinfo.nentries);
1848 if (ret)
1849 return ret;
1850
1851 pos = compat_ptr(tmp.entries);
1852 return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
1853 compat_copy_entry_to_user, &pos, &tmp.entries_size);
1854 }
1855
1856 struct ebt_entries_buf_state {
1857 char *buf_kern_start; /* kernel buffer to copy (translated) data to */
1858 u32 buf_kern_len; /* total size of kernel buffer */
1859 u32 buf_kern_offset; /* amount of data copied so far */
1860 u32 buf_user_offset; /* read position in userspace buffer */
1861 };
1862
1863 static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
1864 {
1865 state->buf_kern_offset += sz;
1866 return state->buf_kern_offset >= sz ? 0 : -EINVAL;
1867 }
1868
1869 static int ebt_buf_add(struct ebt_entries_buf_state *state,
1870 const void *data, unsigned int sz)
1871 {
1872 if (state->buf_kern_start == NULL)
1873 goto count_only;
1874
1875 if (WARN_ON(state->buf_kern_offset + sz > state->buf_kern_len))
1876 return -EINVAL;
1877
1878 memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz);
1879
1880 count_only:
1881 state->buf_user_offset += sz;
1882 return ebt_buf_count(state, sz);
1883 }
1884
1885 static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz)
1886 {
1887 char *b = state->buf_kern_start;
1888
1889 if (WARN_ON(b && state->buf_kern_offset > state->buf_kern_len))
1890 return -EINVAL;
1891
1892 if (b != NULL && sz > 0)
1893 memset(b + state->buf_kern_offset, 0, sz);
1894 /* do not adjust ->buf_user_offset here, we added kernel-side padding */
1895 return ebt_buf_count(state, sz);
1896 }
1897
1898 enum compat_mwt {
1899 EBT_COMPAT_MATCH,
1900 EBT_COMPAT_WATCHER,
1901 EBT_COMPAT_TARGET,
1902 };
1903
1904 static int compat_mtw_from_user(const struct compat_ebt_entry_mwt *mwt,
1905 enum compat_mwt compat_mwt,
1906 struct ebt_entries_buf_state *state,
1907 const unsigned char *base)
1908 {
1909 char name[EBT_EXTENSION_MAXNAMELEN];
1910 struct xt_match *match;
1911 struct xt_target *wt;
1912 void *dst = NULL;
1913 int off, pad = 0;
1914 unsigned int size_kern, match_size = mwt->match_size;
1915
1916 if (strscpy(name, mwt->u.name, sizeof(name)) < 0)
1917 return -EINVAL;
1918
1919 if (state->buf_kern_start)
1920 dst = state->buf_kern_start + state->buf_kern_offset;
1921
1922 switch (compat_mwt) {
1923 case EBT_COMPAT_MATCH:
1924 match = xt_request_find_match(NFPROTO_BRIDGE, name,
1925 mwt->u.revision);
1926 if (IS_ERR(match))
1927 return PTR_ERR(match);
1928
1929 off = ebt_compat_match_offset(match, match_size);
1930 if (dst) {
1931 if (match->compat_from_user)
1932 match->compat_from_user(dst, mwt->data);
1933 else
1934 memcpy(dst, mwt->data, match_size);
1935 }
1936
1937 size_kern = match->matchsize;
1938 if (unlikely(size_kern == -1))
1939 size_kern = match_size;
1940 module_put(match->me);
1941 break;
1942 case EBT_COMPAT_WATCHER: /* fallthrough */
1943 case EBT_COMPAT_TARGET:
1944 wt = xt_request_find_target(NFPROTO_BRIDGE, name,
1945 mwt->u.revision);
1946 if (IS_ERR(wt))
1947 return PTR_ERR(wt);
1948 off = xt_compat_target_offset(wt);
1949
1950 if (dst) {
1951 if (wt->compat_from_user)
1952 wt->compat_from_user(dst, mwt->data);
1953 else
1954 memcpy(dst, mwt->data, match_size);
1955 }
1956
1957 size_kern = wt->targetsize;
1958 module_put(wt->me);
1959 break;
1960
1961 default:
1962 return -EINVAL;
1963 }
1964
1965 state->buf_kern_offset += match_size + off;
1966 state->buf_user_offset += match_size;
1967 pad = XT_ALIGN(size_kern) - size_kern;
1968
1969 if (pad > 0 && dst) {
1970 if (WARN_ON(state->buf_kern_len <= pad))
1971 return -EINVAL;
1972 if (WARN_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad))
1973 return -EINVAL;
1974 memset(dst + size_kern, 0, pad);
1975 }
1976 return off + match_size;
1977 }
1978
1979 /* return size of all matches, watchers or target, including necessary
1980 * alignment and padding.
1981 */
1982 static int ebt_size_mwt(const struct compat_ebt_entry_mwt *match32,
1983 unsigned int size_left, enum compat_mwt type,
1984 struct ebt_entries_buf_state *state, const void *base)
1985 {
1986 const char *buf = (const char *)match32;
1987 int growth = 0;
1988
1989 if (size_left == 0)
1990 return 0;
1991
1992 do {
1993 struct ebt_entry_match *match_kern;
1994 int ret;
1995
1996 if (size_left < sizeof(*match32))
1997 return -EINVAL;
1998
1999 match_kern = (struct ebt_entry_match *) state->buf_kern_start;
2000 if (match_kern) {
2001 char *tmp;
2002 tmp = state->buf_kern_start + state->buf_kern_offset;
2003 match_kern = (struct ebt_entry_match *) tmp;
2004 }
2005 ret = ebt_buf_add(state, buf, sizeof(*match32));
2006 if (ret < 0)
2007 return ret;
2008 size_left -= sizeof(*match32);
2009
2010 /* add padding before match->data (if any) */
2011 ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize());
2012 if (ret < 0)
2013 return ret;
2014
2015 if (match32->match_size > size_left)
2016 return -EINVAL;
2017
2018 size_left -= match32->match_size;
2019
2020 ret = compat_mtw_from_user(match32, type, state, base);
2021 if (ret < 0)
2022 return ret;
2023
2024 if (WARN_ON(ret < match32->match_size))
2025 return -EINVAL;
2026 growth += ret - match32->match_size;
2027 growth += ebt_compat_entry_padsize();
2028
2029 buf += sizeof(*match32);
2030 buf += match32->match_size;
2031
2032 if (match_kern)
2033 match_kern->match_size = ret;
2034
2035 match32 = (struct compat_ebt_entry_mwt *) buf;
2036 } while (size_left);
2037
2038 return growth;
2039 }
2040
2041 /* called for all ebt_entry structures. */
2042 static int size_entry_mwt(const struct ebt_entry *entry, const unsigned char *base,
2043 unsigned int *total,
2044 struct ebt_entries_buf_state *state)
2045 {
2046 unsigned int i, j, startoff, next_expected_off, new_offset = 0;
2047 /* stores match/watchers/targets & offset of next struct ebt_entry: */
2048 unsigned int offsets[4];
2049 unsigned int *offsets_update = NULL;
2050 int ret;
2051 char *buf_start;
2052
2053 if (*total < sizeof(struct ebt_entries))
2054 return -EINVAL;
2055
2056 if (!entry->bitmask) {
2057 *total -= sizeof(struct ebt_entries);
2058 return ebt_buf_add(state, entry, sizeof(struct ebt_entries));
2059 }
2060 if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
2061 return -EINVAL;
2062
2063 startoff = state->buf_user_offset;
2064 /* pull in most part of ebt_entry, it does not need to be changed. */
2065 ret = ebt_buf_add(state, entry,
2066 offsetof(struct ebt_entry, watchers_offset));
2067 if (ret < 0)
2068 return ret;
2069
2070 offsets[0] = sizeof(struct ebt_entry); /* matches come first */
2071 memcpy(&offsets[1], &entry->watchers_offset,
2072 sizeof(offsets) - sizeof(offsets[0]));
2073
2074 if (state->buf_kern_start) {
2075 buf_start = state->buf_kern_start + state->buf_kern_offset;
2076 offsets_update = (unsigned int *) buf_start;
2077 }
2078 ret = ebt_buf_add(state, &offsets[1],
2079 sizeof(offsets) - sizeof(offsets[0]));
2080 if (ret < 0)
2081 return ret;
2082 buf_start = (char *) entry;
2083 /* 0: matches offset, always follows ebt_entry.
2084 * 1: watchers offset, from ebt_entry structure
2085 * 2: target offset, from ebt_entry structure
2086 * 3: next ebt_entry offset, from ebt_entry structure
2087 *
2088 * offsets are relative to beginning of struct ebt_entry (i.e., 0).
2089 */
2090 for (i = 0; i < 4 ; ++i) {
2091 if (offsets[i] > *total)
2092 return -EINVAL;
2093
2094 if (i < 3 && offsets[i] == *total)
2095 return -EINVAL;
2096
2097 if (i == 0)
2098 continue;
2099 if (offsets[i-1] > offsets[i])
2100 return -EINVAL;
2101 }
2102
2103 for (i = 0, j = 1 ; j < 4 ; j++, i++) {
2104 struct compat_ebt_entry_mwt *match32;
2105 unsigned int size;
2106 char *buf = buf_start + offsets[i];
2107
2108 if (offsets[i] > offsets[j])
2109 return -EINVAL;
2110
2111 match32 = (struct compat_ebt_entry_mwt *) buf;
2112 size = offsets[j] - offsets[i];
2113 ret = ebt_size_mwt(match32, size, i, state, base);
2114 if (ret < 0)
2115 return ret;
2116 new_offset += ret;
2117 if (offsets_update && new_offset) {
2118 pr_debug("change offset %d to %d\n",
2119 offsets_update[i], offsets[j] + new_offset);
2120 offsets_update[i] = offsets[j] + new_offset;
2121 }
2122 }
2123
2124 if (state->buf_kern_start == NULL) {
2125 unsigned int offset = buf_start - (char *) base;
2126
2127 ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);
2128 if (ret < 0)
2129 return ret;
2130 }
2131
2132 next_expected_off = state->buf_user_offset - startoff;
2133 if (next_expected_off != entry->next_offset)
2134 return -EINVAL;
2135
2136 if (*total < entry->next_offset)
2137 return -EINVAL;
2138 *total -= entry->next_offset;
2139 return 0;
2140 }
2141
2142 /* repl->entries_size is the size of the ebt_entry blob in userspace.
2143 * It might need more memory when copied to a 64 bit kernel in case
2144 * userspace is 32-bit. So, first task: find out how much memory is needed.
2145 *
2146 * Called before validation is performed.
2147 */
2148 static int compat_copy_entries(unsigned char *data, unsigned int size_user,
2149 struct ebt_entries_buf_state *state)
2150 {
2151 unsigned int size_remaining = size_user;
2152 int ret;
2153
2154 ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
2155 &size_remaining, state);
2156 if (ret < 0)
2157 return ret;
2158
2159 if (size_remaining)
2160 return -EINVAL;
2161
2162 return state->buf_kern_offset;
2163 }
2164
2165
2166 static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
2167 void __user *user, unsigned int len)
2168 {
2169 struct compat_ebt_replace tmp;
2170 int i;
2171
2172 if (len < sizeof(tmp))
2173 return -EINVAL;
2174
2175 if (copy_from_user(&tmp, user, sizeof(tmp)))
2176 return -EFAULT;
2177
2178 if (len != sizeof(tmp) + tmp.entries_size)
2179 return -EINVAL;
2180
2181 if (tmp.entries_size == 0)
2182 return -EINVAL;
2183
2184 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
2185 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
2186 return -ENOMEM;
2187 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
2188 return -ENOMEM;
2189
2190 memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
2191
2192 /* starting with hook_entry, 32 vs. 64 bit structures are different */
2193 for (i = 0; i < NF_BR_NUMHOOKS; i++)
2194 repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]);
2195
2196 repl->num_counters = tmp.num_counters;
2197 repl->counters = compat_ptr(tmp.counters);
2198 repl->entries = compat_ptr(tmp.entries);
2199 return 0;
2200 }
2201
2202 static int compat_do_replace(struct net *net, void __user *user,
2203 unsigned int len)
2204 {
2205 int ret, i, countersize, size64;
2206 struct ebt_table_info *newinfo;
2207 struct ebt_replace tmp;
2208 struct ebt_entries_buf_state state;
2209 void *entries_tmp;
2210
2211 ret = compat_copy_ebt_replace_from_user(&tmp, user, len);
2212 if (ret) {
2213 /* try real handler in case userland supplied needed padding */
2214 if (ret == -EINVAL && do_replace(net, user, len) == 0)
2215 ret = 0;
2216 return ret;
2217 }
2218
2219 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
2220 newinfo = vmalloc(sizeof(*newinfo) + countersize);
2221 if (!newinfo)
2222 return -ENOMEM;
2223
2224 if (countersize)
2225 memset(newinfo->counters, 0, countersize);
2226
2227 memset(&state, 0, sizeof(state));
2228
2229 newinfo->entries = vmalloc(tmp.entries_size);
2230 if (!newinfo->entries) {
2231 ret = -ENOMEM;
2232 goto free_newinfo;
2233 }
2234 if (copy_from_user(
2235 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
2236 ret = -EFAULT;
2237 goto free_entries;
2238 }
2239
2240 entries_tmp = newinfo->entries;
2241
2242 xt_compat_lock(NFPROTO_BRIDGE);
2243
2244 ret = ebt_compat_init_offsets(tmp.nentries);
2245 if (ret < 0)
2246 goto out_unlock;
2247
2248 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2249 if (ret < 0)
2250 goto out_unlock;
2251
2252 pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
2253 tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
2254 xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
2255
2256 size64 = ret;
2257 newinfo->entries = vmalloc(size64);
2258 if (!newinfo->entries) {
2259 vfree(entries_tmp);
2260 ret = -ENOMEM;
2261 goto out_unlock;
2262 }
2263
2264 memset(&state, 0, sizeof(state));
2265 state.buf_kern_start = newinfo->entries;
2266 state.buf_kern_len = size64;
2267
2268 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2269 if (WARN_ON(ret < 0)) {
2270 vfree(entries_tmp);
2271 goto out_unlock;
2272 }
2273
2274 vfree(entries_tmp);
2275 tmp.entries_size = size64;
2276
2277 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
2278 char __user *usrptr;
2279 if (tmp.hook_entry[i]) {
2280 unsigned int delta;
2281 usrptr = (char __user *) tmp.hook_entry[i];
2282 delta = usrptr - tmp.entries;
2283 usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta);
2284 tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
2285 }
2286 }
2287
2288 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2289 xt_compat_unlock(NFPROTO_BRIDGE);
2290
2291 ret = do_replace_finish(net, &tmp, newinfo);
2292 if (ret == 0)
2293 return ret;
2294 free_entries:
2295 vfree(newinfo->entries);
2296 free_newinfo:
2297 vfree(newinfo);
2298 return ret;
2299 out_unlock:
2300 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2301 xt_compat_unlock(NFPROTO_BRIDGE);
2302 goto free_entries;
2303 }
2304
2305 static int compat_update_counters(struct net *net, void __user *user,
2306 unsigned int len)
2307 {
2308 struct compat_ebt_replace hlp;
2309
2310 if (copy_from_user(&hlp, user, sizeof(hlp)))
2311 return -EFAULT;
2312
2313 /* try real handler in case userland supplied needed padding */
2314 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
2315 return update_counters(net, user, len);
2316
2317 return do_update_counters(net, hlp.name, compat_ptr(hlp.counters),
2318 hlp.num_counters, user, len);
2319 }
2320
2321 static int compat_do_ebt_set_ctl(struct sock *sk,
2322 int cmd, void __user *user, unsigned int len)
2323 {
2324 int ret;
2325 struct net *net = sock_net(sk);
2326
2327 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2328 return -EPERM;
2329
2330 switch (cmd) {
2331 case EBT_SO_SET_ENTRIES:
2332 ret = compat_do_replace(net, user, len);
2333 break;
2334 case EBT_SO_SET_COUNTERS:
2335 ret = compat_update_counters(net, user, len);
2336 break;
2337 default:
2338 ret = -EINVAL;
2339 }
2340 return ret;
2341 }
2342
2343 static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
2344 void __user *user, int *len)
2345 {
2346 int ret;
2347 struct compat_ebt_replace tmp;
2348 struct ebt_table *t;
2349 struct net *net = sock_net(sk);
2350
2351 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2352 return -EPERM;
2353
2354 /* try real handler in case userland supplied needed padding */
2355 if ((cmd == EBT_SO_GET_INFO ||
2356 cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp))
2357 return do_ebt_get_ctl(sk, cmd, user, len);
2358
2359 if (copy_from_user(&tmp, user, sizeof(tmp)))
2360 return -EFAULT;
2361
2362 tmp.name[sizeof(tmp.name) - 1] = '\0';
2363
2364 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
2365 if (!t)
2366 return ret;
2367
2368 xt_compat_lock(NFPROTO_BRIDGE);
2369 switch (cmd) {
2370 case EBT_SO_GET_INFO:
2371 tmp.nentries = t->private->nentries;
2372 ret = compat_table_info(t->private, &tmp);
2373 if (ret)
2374 goto out;
2375 tmp.valid_hooks = t->valid_hooks;
2376
2377 if (copy_to_user(user, &tmp, *len) != 0) {
2378 ret = -EFAULT;
2379 break;
2380 }
2381 ret = 0;
2382 break;
2383 case EBT_SO_GET_INIT_INFO:
2384 tmp.nentries = t->table->nentries;
2385 tmp.entries_size = t->table->entries_size;
2386 tmp.valid_hooks = t->table->valid_hooks;
2387
2388 if (copy_to_user(user, &tmp, *len) != 0) {
2389 ret = -EFAULT;
2390 break;
2391 }
2392 ret = 0;
2393 break;
2394 case EBT_SO_GET_ENTRIES:
2395 case EBT_SO_GET_INIT_ENTRIES:
2396 /* try real handler first in case of userland-side padding.
2397 * in case we are dealing with an 'ordinary' 32 bit binary
2398 * without 64bit compatibility padding, this will fail right
2399 * after copy_from_user when the *len argument is validated.
2400 *
2401 * the compat_ variant needs to do one pass over the kernel
2402 * data set to adjust for size differences before it the check.
2403 */
2404 if (copy_everything_to_user(t, user, len, cmd) == 0)
2405 ret = 0;
2406 else
2407 ret = compat_copy_everything_to_user(t, user, len, cmd);
2408 break;
2409 default:
2410 ret = -EINVAL;
2411 }
2412 out:
2413 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2414 xt_compat_unlock(NFPROTO_BRIDGE);
2415 mutex_unlock(&ebt_mutex);
2416 return ret;
2417 }
2418 #endif
2419
2420 static struct nf_sockopt_ops ebt_sockopts = {
2421 .pf = PF_INET,
2422 .set_optmin = EBT_BASE_CTL,
2423 .set_optmax = EBT_SO_SET_MAX + 1,
2424 .set = do_ebt_set_ctl,
2425 #ifdef CONFIG_COMPAT
2426 .compat_set = compat_do_ebt_set_ctl,
2427 #endif
2428 .get_optmin = EBT_BASE_CTL,
2429 .get_optmax = EBT_SO_GET_MAX + 1,
2430 .get = do_ebt_get_ctl,
2431 #ifdef CONFIG_COMPAT
2432 .compat_get = compat_do_ebt_get_ctl,
2433 #endif
2434 .owner = THIS_MODULE,
2435 };
2436
2437 static int __init ebtables_init(void)
2438 {
2439 int ret;
2440
2441 ret = xt_register_target(&ebt_standard_target);
2442 if (ret < 0)
2443 return ret;
2444 ret = nf_register_sockopt(&ebt_sockopts);
2445 if (ret < 0) {
2446 xt_unregister_target(&ebt_standard_target);
2447 return ret;
2448 }
2449
2450 return 0;
2451 }
2452
2453 static void __exit ebtables_fini(void)
2454 {
2455 nf_unregister_sockopt(&ebt_sockopts);
2456 xt_unregister_target(&ebt_standard_target);
2457 }
2458
2459 EXPORT_SYMBOL(ebt_register_table);
2460 EXPORT_SYMBOL(ebt_unregister_table);
2461 EXPORT_SYMBOL(ebt_do_table);
2462 module_init(ebtables_init);
2463 module_exit(ebtables_fini);
2464 MODULE_LICENSE("GPL");
Linux with added FPC-III support