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Linux 3.12.28
[linux/fpc-iii.git] / net / bridge / netfilter / ebtables.c
blobb166fc2ec4b994e43c274ea58f5c4d041ef6ab35
1 /*
2 * ebtables
3 *
4 * Author:
5 * Bart De Schuymer <bdschuym@pandora.be>
6 *
7 * ebtables.c,v 2.0, July, 2002
8 *
9 * This code is stongly inspired on the iptables code which is
10 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/kmod.h>
19 #include <linux/module.h>
20 #include <linux/vmalloc.h>
21 #include <linux/netfilter/x_tables.h>
22 #include <linux/netfilter_bridge/ebtables.h>
23 #include <linux/spinlock.h>
24 #include <linux/mutex.h>
25 #include <linux/slab.h>
26 #include <asm/uaccess.h>
27 #include <linux/smp.h>
28 #include <linux/cpumask.h>
29 #include <net/sock.h>
30 /* needed for logical [in,out]-dev filtering */
31 #include "../br_private.h"
32
33 #define BUGPRINT(format, args...) printk("kernel msg: ebtables bug: please "\
34 "report to author: "format, ## args)
35 /* #define BUGPRINT(format, args...) */
36
37 /*
38 * Each cpu has its own set of counters, so there is no need for write_lock in
39 * the softirq
40 * For reading or updating the counters, the user context needs to
41 * get a write_lock
42 */
43
44 /* The size of each set of counters is altered to get cache alignment */
45 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
46 #define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter)))
47 #define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \
48 COUNTER_OFFSET(n) * cpu))
49
50
51
52 static DEFINE_MUTEX(ebt_mutex);
53
54 #ifdef CONFIG_COMPAT
55 static void ebt_standard_compat_from_user(void *dst, const void *src)
56 {
57 int v = *(compat_int_t *)src;
58
59 if (v >= 0)
60 v += xt_compat_calc_jump(NFPROTO_BRIDGE, v);
61 memcpy(dst, &v, sizeof(v));
62 }
63
64 static int ebt_standard_compat_to_user(void __user *dst, const void *src)
65 {
66 compat_int_t cv = *(int *)src;
67
68 if (cv >= 0)
69 cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv);
70 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
71 }
72 #endif
73
74
75 static struct xt_target ebt_standard_target = {
76 .name = "standard",
77 .revision = 0,
78 .family = NFPROTO_BRIDGE,
79 .targetsize = sizeof(int),
80 #ifdef CONFIG_COMPAT
81 .compatsize = sizeof(compat_int_t),
82 .compat_from_user = ebt_standard_compat_from_user,
83 .compat_to_user = ebt_standard_compat_to_user,
84 #endif
85 };
86
87 static inline int
88 ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb,
89 struct xt_action_param *par)
90 {
91 par->target = w->u.watcher;
92 par->targinfo = w->data;
93 w->u.watcher->target(skb, par);
94 /* watchers don't give a verdict */
95 return 0;
96 }
97
98 static inline int
99 ebt_do_match(struct ebt_entry_match *m, const struct sk_buff *skb,
100 struct xt_action_param *par)
101 {
102 par->match = m->u.match;
103 par->matchinfo = m->data;
104 return m->u.match->match(skb, par) ? EBT_MATCH : EBT_NOMATCH;
105 }
106
107 static inline int
108 ebt_dev_check(const char *entry, const struct net_device *device)
109 {
110 int i = 0;
111 const char *devname;
112
113 if (*entry == '\0')
114 return 0;
115 if (!device)
116 return 1;
117 devname = device->name;
118 /* 1 is the wildcard token */
119 while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i])
120 i++;
121 return (devname[i] != entry[i] && entry[i] != 1);
122 }
123
124 #define FWINV2(bool,invflg) ((bool) ^ !!(e->invflags & invflg))
125 /* process standard matches */
126 static inline int
127 ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb,
128 const struct net_device *in, const struct net_device *out)
129 {
130 const struct ethhdr *h = eth_hdr(skb);
131 const struct net_bridge_port *p;
132 __be16 ethproto;
133 int verdict, i;
134
135 if (vlan_tx_tag_present(skb))
136 ethproto = htons(ETH_P_8021Q);
137 else
138 ethproto = h->h_proto;
139
140 if (e->bitmask & EBT_802_3) {
141 if (FWINV2(ntohs(ethproto) >= ETH_P_802_3_MIN, EBT_IPROTO))
142 return 1;
143 } else if (!(e->bitmask & EBT_NOPROTO) &&
144 FWINV2(e->ethproto != ethproto, EBT_IPROTO))
145 return 1;
146
147 if (FWINV2(ebt_dev_check(e->in, in), EBT_IIN))
148 return 1;
149 if (FWINV2(ebt_dev_check(e->out, out), EBT_IOUT))
150 return 1;
151 /* rcu_read_lock()ed by nf_hook_slow */
152 if (in && (p = br_port_get_rcu(in)) != NULL &&
153 FWINV2(ebt_dev_check(e->logical_in, p->br->dev), EBT_ILOGICALIN))
154 return 1;
155 if (out && (p = br_port_get_rcu(out)) != NULL &&
156 FWINV2(ebt_dev_check(e->logical_out, p->br->dev), EBT_ILOGICALOUT))
157 return 1;
158
159 if (e->bitmask & EBT_SOURCEMAC) {
160 verdict = 0;
161 for (i = 0; i < 6; i++)
162 verdict |= (h->h_source[i] ^ e->sourcemac[i]) &
163 e->sourcemsk[i];
164 if (FWINV2(verdict != 0, EBT_ISOURCE) )
165 return 1;
166 }
167 if (e->bitmask & EBT_DESTMAC) {
168 verdict = 0;
169 for (i = 0; i < 6; i++)
170 verdict |= (h->h_dest[i] ^ e->destmac[i]) &
171 e->destmsk[i];
172 if (FWINV2(verdict != 0, EBT_IDEST) )
173 return 1;
174 }
175 return 0;
176 }
177
178 static inline __pure
179 struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry)
180 {
181 return (void *)entry + entry->next_offset;
182 }
183
184 /* Do some firewalling */
185 unsigned int ebt_do_table (unsigned int hook, struct sk_buff *skb,
186 const struct net_device *in, const struct net_device *out,
187 struct ebt_table *table)
188 {
189 int i, nentries;
190 struct ebt_entry *point;
191 struct ebt_counter *counter_base, *cb_base;
192 const struct ebt_entry_target *t;
193 int verdict, sp = 0;
194 struct ebt_chainstack *cs;
195 struct ebt_entries *chaininfo;
196 const char *base;
197 const struct ebt_table_info *private;
198 struct xt_action_param acpar;
199
200 acpar.family = NFPROTO_BRIDGE;
201 acpar.in = in;
202 acpar.out = out;
203 acpar.hotdrop = false;
204 acpar.hooknum = hook;
205
206 read_lock_bh(&table->lock);
207 private = table->private;
208 cb_base = COUNTER_BASE(private->counters, private->nentries,
209 smp_processor_id());
210 if (private->chainstack)
211 cs = private->chainstack[smp_processor_id()];
212 else
213 cs = NULL;
214 chaininfo = private->hook_entry[hook];
215 nentries = private->hook_entry[hook]->nentries;
216 point = (struct ebt_entry *)(private->hook_entry[hook]->data);
217 counter_base = cb_base + private->hook_entry[hook]->counter_offset;
218 /* base for chain jumps */
219 base = private->entries;
220 i = 0;
221 while (i < nentries) {
222 if (ebt_basic_match(point, skb, in, out))
223 goto letscontinue;
224
225 if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0)
226 goto letscontinue;
227 if (acpar.hotdrop) {
228 read_unlock_bh(&table->lock);
229 return NF_DROP;
230 }
231
232 /* increase counter */
233 (*(counter_base + i)).pcnt++;
234 (*(counter_base + i)).bcnt += skb->len;
235
236 /* these should only watch: not modify, nor tell us
237 what to do with the packet */
238 EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar);
239
240 t = (struct ebt_entry_target *)
241 (((char *)point) + point->target_offset);
242 /* standard target */
243 if (!t->u.target->target)
244 verdict = ((struct ebt_standard_target *)t)->verdict;
245 else {
246 acpar.target = t->u.target;
247 acpar.targinfo = t->data;
248 verdict = t->u.target->target(skb, &acpar);
249 }
250 if (verdict == EBT_ACCEPT) {
251 read_unlock_bh(&table->lock);
252 return NF_ACCEPT;
253 }
254 if (verdict == EBT_DROP) {
255 read_unlock_bh(&table->lock);
256 return NF_DROP;
257 }
258 if (verdict == EBT_RETURN) {
259 letsreturn:
260 #ifdef CONFIG_NETFILTER_DEBUG
261 if (sp == 0) {
262 BUGPRINT("RETURN on base chain");
263 /* act like this is EBT_CONTINUE */
264 goto letscontinue;
265 }
266 #endif
267 sp--;
268 /* put all the local variables right */
269 i = cs[sp].n;
270 chaininfo = cs[sp].chaininfo;
271 nentries = chaininfo->nentries;
272 point = cs[sp].e;
273 counter_base = cb_base +
274 chaininfo->counter_offset;
275 continue;
276 }
277 if (verdict == EBT_CONTINUE)
278 goto letscontinue;
279 #ifdef CONFIG_NETFILTER_DEBUG
280 if (verdict < 0) {
281 BUGPRINT("bogus standard verdict\n");
282 read_unlock_bh(&table->lock);
283 return NF_DROP;
284 }
285 #endif
286 /* jump to a udc */
287 cs[sp].n = i + 1;
288 cs[sp].chaininfo = chaininfo;
289 cs[sp].e = ebt_next_entry(point);
290 i = 0;
291 chaininfo = (struct ebt_entries *) (base + verdict);
292 #ifdef CONFIG_NETFILTER_DEBUG
293 if (chaininfo->distinguisher) {
294 BUGPRINT("jump to non-chain\n");
295 read_unlock_bh(&table->lock);
296 return NF_DROP;
297 }
298 #endif
299 nentries = chaininfo->nentries;
300 point = (struct ebt_entry *)chaininfo->data;
301 counter_base = cb_base + chaininfo->counter_offset;
302 sp++;
303 continue;
304 letscontinue:
305 point = ebt_next_entry(point);
306 i++;
307 }
308
309 /* I actually like this :) */
310 if (chaininfo->policy == EBT_RETURN)
311 goto letsreturn;
312 if (chaininfo->policy == EBT_ACCEPT) {
313 read_unlock_bh(&table->lock);
314 return NF_ACCEPT;
315 }
316 read_unlock_bh(&table->lock);
317 return NF_DROP;
318 }
319
320 /* If it succeeds, returns element and locks mutex */
321 static inline void *
322 find_inlist_lock_noload(struct list_head *head, const char *name, int *error,
323 struct mutex *mutex)
324 {
325 struct {
326 struct list_head list;
327 char name[EBT_FUNCTION_MAXNAMELEN];
328 } *e;
329
330 *error = mutex_lock_interruptible(mutex);
331 if (*error != 0)
332 return NULL;
333
334 list_for_each_entry(e, head, list) {
335 if (strcmp(e->name, name) == 0)
336 return e;
337 }
338 *error = -ENOENT;
339 mutex_unlock(mutex);
340 return NULL;
341 }
342
343 static void *
344 find_inlist_lock(struct list_head *head, const char *name, const char *prefix,
345 int *error, struct mutex *mutex)
346 {
347 return try_then_request_module(
348 find_inlist_lock_noload(head, name, error, mutex),
349 "%s%s", prefix, name);
350 }
351
352 static inline struct ebt_table *
353 find_table_lock(struct net *net, const char *name, int *error,
354 struct mutex *mutex)
355 {
356 return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name,
357 "ebtable_", error, mutex);
358 }
359
360 static inline int
361 ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
362 unsigned int *cnt)
363 {
364 const struct ebt_entry *e = par->entryinfo;
365 struct xt_match *match;
366 size_t left = ((char *)e + e->watchers_offset) - (char *)m;
367 int ret;
368
369 if (left < sizeof(struct ebt_entry_match) ||
370 left - sizeof(struct ebt_entry_match) < m->match_size)
371 return -EINVAL;
372
373 match = xt_request_find_match(NFPROTO_BRIDGE, m->u.name, 0);
374 if (IS_ERR(match))
375 return PTR_ERR(match);
376 m->u.match = match;
377
378 par->match = match;
379 par->matchinfo = m->data;
380 ret = xt_check_match(par, m->match_size,
381 e->ethproto, e->invflags & EBT_IPROTO);
382 if (ret < 0) {
383 module_put(match->me);
384 return ret;
385 }
386
387 (*cnt)++;
388 return 0;
389 }
390
391 static inline int
392 ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
393 unsigned int *cnt)
394 {
395 const struct ebt_entry *e = par->entryinfo;
396 struct xt_target *watcher;
397 size_t left = ((char *)e + e->target_offset) - (char *)w;
398 int ret;
399
400 if (left < sizeof(struct ebt_entry_watcher) ||
401 left - sizeof(struct ebt_entry_watcher) < w->watcher_size)
402 return -EINVAL;
403
404 watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0);
405 if (IS_ERR(watcher))
406 return PTR_ERR(watcher);
407 w->u.watcher = watcher;
408
409 par->target = watcher;
410 par->targinfo = w->data;
411 ret = xt_check_target(par, w->watcher_size,
412 e->ethproto, e->invflags & EBT_IPROTO);
413 if (ret < 0) {
414 module_put(watcher->me);
415 return ret;
416 }
417
418 (*cnt)++;
419 return 0;
420 }
421
422 static int ebt_verify_pointers(const struct ebt_replace *repl,
423 struct ebt_table_info *newinfo)
424 {
425 unsigned int limit = repl->entries_size;
426 unsigned int valid_hooks = repl->valid_hooks;
427 unsigned int offset = 0;
428 int i;
429
430 for (i = 0; i < NF_BR_NUMHOOKS; i++)
431 newinfo->hook_entry[i] = NULL;
432
433 newinfo->entries_size = repl->entries_size;
434 newinfo->nentries = repl->nentries;
435
436 while (offset < limit) {
437 size_t left = limit - offset;
438 struct ebt_entry *e = (void *)newinfo->entries + offset;
439
440 if (left < sizeof(unsigned int))
441 break;
442
443 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
444 if ((valid_hooks & (1 << i)) == 0)
445 continue;
446 if ((char __user *)repl->hook_entry[i] ==
447 repl->entries + offset)
448 break;
449 }
450
451 if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
452 if (e->bitmask != 0) {
453 /* we make userspace set this right,
454 so there is no misunderstanding */
455 BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set "
456 "in distinguisher\n");
457 return -EINVAL;
458 }
459 if (i != NF_BR_NUMHOOKS)
460 newinfo->hook_entry[i] = (struct ebt_entries *)e;
461 if (left < sizeof(struct ebt_entries))
462 break;
463 offset += sizeof(struct ebt_entries);
464 } else {
465 if (left < sizeof(struct ebt_entry))
466 break;
467 if (left < e->next_offset)
468 break;
469 if (e->next_offset < sizeof(struct ebt_entry))
470 return -EINVAL;
471 offset += e->next_offset;
472 }
473 }
474 if (offset != limit) {
475 BUGPRINT("entries_size too small\n");
476 return -EINVAL;
477 }
478
479 /* check if all valid hooks have a chain */
480 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
481 if (!newinfo->hook_entry[i] &&
482 (valid_hooks & (1 << i))) {
483 BUGPRINT("Valid hook without chain\n");
484 return -EINVAL;
485 }
486 }
487 return 0;
488 }
489
490 /*
491 * this one is very careful, as it is the first function
492 * to parse the userspace data
493 */
494 static inline int
495 ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
496 const struct ebt_table_info *newinfo,
497 unsigned int *n, unsigned int *cnt,
498 unsigned int *totalcnt, unsigned int *udc_cnt)
499 {
500 int i;
501
502 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
503 if ((void *)e == (void *)newinfo->hook_entry[i])
504 break;
505 }
506 /* beginning of a new chain
507 if i == NF_BR_NUMHOOKS it must be a user defined chain */
508 if (i != NF_BR_NUMHOOKS || !e->bitmask) {
509 /* this checks if the previous chain has as many entries
510 as it said it has */
511 if (*n != *cnt) {
512 BUGPRINT("nentries does not equal the nr of entries "
513 "in the chain\n");
514 return -EINVAL;
515 }
516 if (((struct ebt_entries *)e)->policy != EBT_DROP &&
517 ((struct ebt_entries *)e)->policy != EBT_ACCEPT) {
518 /* only RETURN from udc */
519 if (i != NF_BR_NUMHOOKS ||
520 ((struct ebt_entries *)e)->policy != EBT_RETURN) {
521 BUGPRINT("bad policy\n");
522 return -EINVAL;
523 }
524 }
525 if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */
526 (*udc_cnt)++;
527 if (((struct ebt_entries *)e)->counter_offset != *totalcnt) {
528 BUGPRINT("counter_offset != totalcnt");
529 return -EINVAL;
530 }
531 *n = ((struct ebt_entries *)e)->nentries;
532 *cnt = 0;
533 return 0;
534 }
535 /* a plain old entry, heh */
536 if (sizeof(struct ebt_entry) > e->watchers_offset ||
537 e->watchers_offset > e->target_offset ||
538 e->target_offset >= e->next_offset) {
539 BUGPRINT("entry offsets not in right order\n");
540 return -EINVAL;
541 }
542 /* this is not checked anywhere else */
543 if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target)) {
544 BUGPRINT("target size too small\n");
545 return -EINVAL;
546 }
547 (*cnt)++;
548 (*totalcnt)++;
549 return 0;
550 }
551
552 struct ebt_cl_stack
553 {
554 struct ebt_chainstack cs;
555 int from;
556 unsigned int hookmask;
557 };
558
559 /*
560 * we need these positions to check that the jumps to a different part of the
561 * entries is a jump to the beginning of a new chain.
562 */
563 static inline int
564 ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo,
565 unsigned int *n, struct ebt_cl_stack *udc)
566 {
567 int i;
568
569 /* we're only interested in chain starts */
570 if (e->bitmask)
571 return 0;
572 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
573 if (newinfo->hook_entry[i] == (struct ebt_entries *)e)
574 break;
575 }
576 /* only care about udc */
577 if (i != NF_BR_NUMHOOKS)
578 return 0;
579
580 udc[*n].cs.chaininfo = (struct ebt_entries *)e;
581 /* these initialisations are depended on later in check_chainloops() */
582 udc[*n].cs.n = 0;
583 udc[*n].hookmask = 0;
584
585 (*n)++;
586 return 0;
587 }
588
589 static inline int
590 ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i)
591 {
592 struct xt_mtdtor_param par;
593
594 if (i && (*i)-- == 0)
595 return 1;
596
597 par.net = net;
598 par.match = m->u.match;
599 par.matchinfo = m->data;
600 par.family = NFPROTO_BRIDGE;
601 if (par.match->destroy != NULL)
602 par.match->destroy(&par);
603 module_put(par.match->me);
604 return 0;
605 }
606
607 static inline int
608 ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i)
609 {
610 struct xt_tgdtor_param par;
611
612 if (i && (*i)-- == 0)
613 return 1;
614
615 par.net = net;
616 par.target = w->u.watcher;
617 par.targinfo = w->data;
618 par.family = NFPROTO_BRIDGE;
619 if (par.target->destroy != NULL)
620 par.target->destroy(&par);
621 module_put(par.target->me);
622 return 0;
623 }
624
625 static inline int
626 ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
627 {
628 struct xt_tgdtor_param par;
629 struct ebt_entry_target *t;
630
631 if (e->bitmask == 0)
632 return 0;
633 /* we're done */
634 if (cnt && (*cnt)-- == 0)
635 return 1;
636 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL);
637 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL);
638 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
639
640 par.net = net;
641 par.target = t->u.target;
642 par.targinfo = t->data;
643 par.family = NFPROTO_BRIDGE;
644 if (par.target->destroy != NULL)
645 par.target->destroy(&par);
646 module_put(par.target->me);
647 return 0;
648 }
649
650 static inline int
651 ebt_check_entry(struct ebt_entry *e, struct net *net,
652 const struct ebt_table_info *newinfo,
653 const char *name, unsigned int *cnt,
654 struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
655 {
656 struct ebt_entry_target *t;
657 struct xt_target *target;
658 unsigned int i, j, hook = 0, hookmask = 0;
659 size_t gap;
660 int ret;
661 struct xt_mtchk_param mtpar;
662 struct xt_tgchk_param tgpar;
663
664 /* don't mess with the struct ebt_entries */
665 if (e->bitmask == 0)
666 return 0;
667
668 if (e->bitmask & ~EBT_F_MASK) {
669 BUGPRINT("Unknown flag for bitmask\n");
670 return -EINVAL;
671 }
672 if (e->invflags & ~EBT_INV_MASK) {
673 BUGPRINT("Unknown flag for inv bitmask\n");
674 return -EINVAL;
675 }
676 if ( (e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3) ) {
677 BUGPRINT("NOPROTO & 802_3 not allowed\n");
678 return -EINVAL;
679 }
680 /* what hook do we belong to? */
681 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
682 if (!newinfo->hook_entry[i])
683 continue;
684 if ((char *)newinfo->hook_entry[i] < (char *)e)
685 hook = i;
686 else
687 break;
688 }
689 /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on
690 a base chain */
691 if (i < NF_BR_NUMHOOKS)
692 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
693 else {
694 for (i = 0; i < udc_cnt; i++)
695 if ((char *)(cl_s[i].cs.chaininfo) > (char *)e)
696 break;
697 if (i == 0)
698 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
699 else
700 hookmask = cl_s[i - 1].hookmask;
701 }
702 i = 0;
703
704 mtpar.net = tgpar.net = net;
705 mtpar.table = tgpar.table = name;
706 mtpar.entryinfo = tgpar.entryinfo = e;
707 mtpar.hook_mask = tgpar.hook_mask = hookmask;
708 mtpar.family = tgpar.family = NFPROTO_BRIDGE;
709 ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i);
710 if (ret != 0)
711 goto cleanup_matches;
712 j = 0;
713 ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j);
714 if (ret != 0)
715 goto cleanup_watchers;
716 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
717 gap = e->next_offset - e->target_offset;
718
719 target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0);
720 if (IS_ERR(target)) {
721 ret = PTR_ERR(target);
722 goto cleanup_watchers;
723 }
724
725 t->u.target = target;
726 if (t->u.target == &ebt_standard_target) {
727 if (gap < sizeof(struct ebt_standard_target)) {
728 BUGPRINT("Standard target size too big\n");
729 ret = -EFAULT;
730 goto cleanup_watchers;
731 }
732 if (((struct ebt_standard_target *)t)->verdict <
733 -NUM_STANDARD_TARGETS) {
734 BUGPRINT("Invalid standard target\n");
735 ret = -EFAULT;
736 goto cleanup_watchers;
737 }
738 } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) {
739 module_put(t->u.target->me);
740 ret = -EFAULT;
741 goto cleanup_watchers;
742 }
743
744 tgpar.target = target;
745 tgpar.targinfo = t->data;
746 ret = xt_check_target(&tgpar, t->target_size,
747 e->ethproto, e->invflags & EBT_IPROTO);
748 if (ret < 0) {
749 module_put(target->me);
750 goto cleanup_watchers;
751 }
752 (*cnt)++;
753 return 0;
754 cleanup_watchers:
755 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j);
756 cleanup_matches:
757 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i);
758 return ret;
759 }
760
761 /*
762 * checks for loops and sets the hook mask for udc
763 * the hook mask for udc tells us from which base chains the udc can be
764 * accessed. This mask is a parameter to the check() functions of the extensions
765 */
766 static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
767 unsigned int udc_cnt, unsigned int hooknr, char *base)
768 {
769 int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
770 const struct ebt_entry *e = (struct ebt_entry *)chain->data;
771 const struct ebt_entry_target *t;
772
773 while (pos < nentries || chain_nr != -1) {
774 /* end of udc, go back one 'recursion' step */
775 if (pos == nentries) {
776 /* put back values of the time when this chain was called */
777 e = cl_s[chain_nr].cs.e;
778 if (cl_s[chain_nr].from != -1)
779 nentries =
780 cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries;
781 else
782 nentries = chain->nentries;
783 pos = cl_s[chain_nr].cs.n;
784 /* make sure we won't see a loop that isn't one */
785 cl_s[chain_nr].cs.n = 0;
786 chain_nr = cl_s[chain_nr].from;
787 if (pos == nentries)
788 continue;
789 }
790 t = (struct ebt_entry_target *)
791 (((char *)e) + e->target_offset);
792 if (strcmp(t->u.name, EBT_STANDARD_TARGET))
793 goto letscontinue;
794 if (e->target_offset + sizeof(struct ebt_standard_target) >
795 e->next_offset) {
796 BUGPRINT("Standard target size too big\n");
797 return -1;
798 }
799 verdict = ((struct ebt_standard_target *)t)->verdict;
800 if (verdict >= 0) { /* jump to another chain */
801 struct ebt_entries *hlp2 =
802 (struct ebt_entries *)(base + verdict);
803 for (i = 0; i < udc_cnt; i++)
804 if (hlp2 == cl_s[i].cs.chaininfo)
805 break;
806 /* bad destination or loop */
807 if (i == udc_cnt) {
808 BUGPRINT("bad destination\n");
809 return -1;
810 }
811 if (cl_s[i].cs.n) {
812 BUGPRINT("loop\n");
813 return -1;
814 }
815 if (cl_s[i].hookmask & (1 << hooknr))
816 goto letscontinue;
817 /* this can't be 0, so the loop test is correct */
818 cl_s[i].cs.n = pos + 1;
819 pos = 0;
820 cl_s[i].cs.e = ebt_next_entry(e);
821 e = (struct ebt_entry *)(hlp2->data);
822 nentries = hlp2->nentries;
823 cl_s[i].from = chain_nr;
824 chain_nr = i;
825 /* this udc is accessible from the base chain for hooknr */
826 cl_s[i].hookmask |= (1 << hooknr);
827 continue;
828 }
829 letscontinue:
830 e = ebt_next_entry(e);
831 pos++;
832 }
833 return 0;
834 }
835
836 /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
837 static int translate_table(struct net *net, const char *name,
838 struct ebt_table_info *newinfo)
839 {
840 unsigned int i, j, k, udc_cnt;
841 int ret;
842 struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */
843
844 i = 0;
845 while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i])
846 i++;
847 if (i == NF_BR_NUMHOOKS) {
848 BUGPRINT("No valid hooks specified\n");
849 return -EINVAL;
850 }
851 if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) {
852 BUGPRINT("Chains don't start at beginning\n");
853 return -EINVAL;
854 }
855 /* make sure chains are ordered after each other in same order
856 as their corresponding hooks */
857 for (j = i + 1; j < NF_BR_NUMHOOKS; j++) {
858 if (!newinfo->hook_entry[j])
859 continue;
860 if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) {
861 BUGPRINT("Hook order must be followed\n");
862 return -EINVAL;
863 }
864 i = j;
865 }
866
867 /* do some early checkings and initialize some things */
868 i = 0; /* holds the expected nr. of entries for the chain */
869 j = 0; /* holds the up to now counted entries for the chain */
870 k = 0; /* holds the total nr. of entries, should equal
871 newinfo->nentries afterwards */
872 udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */
873 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
874 ebt_check_entry_size_and_hooks, newinfo,
875 &i, &j, &k, &udc_cnt);
876
877 if (ret != 0)
878 return ret;
879
880 if (i != j) {
881 BUGPRINT("nentries does not equal the nr of entries in the "
882 "(last) chain\n");
883 return -EINVAL;
884 }
885 if (k != newinfo->nentries) {
886 BUGPRINT("Total nentries is wrong\n");
887 return -EINVAL;
888 }
889
890 /* get the location of the udc, put them in an array
891 while we're at it, allocate the chainstack */
892 if (udc_cnt) {
893 /* this will get free'd in do_replace()/ebt_register_table()
894 if an error occurs */
895 newinfo->chainstack =
896 vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack)));
897 if (!newinfo->chainstack)
898 return -ENOMEM;
899 for_each_possible_cpu(i) {
900 newinfo->chainstack[i] =
901 vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0])));
902 if (!newinfo->chainstack[i]) {
903 while (i)
904 vfree(newinfo->chainstack[--i]);
905 vfree(newinfo->chainstack);
906 newinfo->chainstack = NULL;
907 return -ENOMEM;
908 }
909 }
910
911 cl_s = vmalloc(udc_cnt * sizeof(*cl_s));
912 if (!cl_s)
913 return -ENOMEM;
914 i = 0; /* the i'th udc */
915 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
916 ebt_get_udc_positions, newinfo, &i, cl_s);
917 /* sanity check */
918 if (i != udc_cnt) {
919 BUGPRINT("i != udc_cnt\n");
920 vfree(cl_s);
921 return -EFAULT;
922 }
923 }
924
925 /* Check for loops */
926 for (i = 0; i < NF_BR_NUMHOOKS; i++)
927 if (newinfo->hook_entry[i])
928 if (check_chainloops(newinfo->hook_entry[i],
929 cl_s, udc_cnt, i, newinfo->entries)) {
930 vfree(cl_s);
931 return -EINVAL;
932 }
933
934 /* we now know the following (along with E=mc²):
935 - the nr of entries in each chain is right
936 - the size of the allocated space is right
937 - all valid hooks have a corresponding chain
938 - there are no loops
939 - wrong data can still be on the level of a single entry
940 - could be there are jumps to places that are not the
941 beginning of a chain. This can only occur in chains that
942 are not accessible from any base chains, so we don't care. */
943
944 /* used to know what we need to clean up if something goes wrong */
945 i = 0;
946 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
947 ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt);
948 if (ret != 0) {
949 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
950 ebt_cleanup_entry, net, &i);
951 }
952 vfree(cl_s);
953 return ret;
954 }
955
956 /* called under write_lock */
957 static void get_counters(const struct ebt_counter *oldcounters,
958 struct ebt_counter *counters, unsigned int nentries)
959 {
960 int i, cpu;
961 struct ebt_counter *counter_base;
962
963 /* counters of cpu 0 */
964 memcpy(counters, oldcounters,
965 sizeof(struct ebt_counter) * nentries);
966
967 /* add other counters to those of cpu 0 */
968 for_each_possible_cpu(cpu) {
969 if (cpu == 0)
970 continue;
971 counter_base = COUNTER_BASE(oldcounters, nentries, cpu);
972 for (i = 0; i < nentries; i++) {
973 counters[i].pcnt += counter_base[i].pcnt;
974 counters[i].bcnt += counter_base[i].bcnt;
975 }
976 }
977 }
978
979 static int do_replace_finish(struct net *net, struct ebt_replace *repl,
980 struct ebt_table_info *newinfo)
981 {
982 int ret, i;
983 struct ebt_counter *counterstmp = NULL;
984 /* used to be able to unlock earlier */
985 struct ebt_table_info *table;
986 struct ebt_table *t;
987
988 /* the user wants counters back
989 the check on the size is done later, when we have the lock */
990 if (repl->num_counters) {
991 unsigned long size = repl->num_counters * sizeof(*counterstmp);
992 counterstmp = vmalloc(size);
993 if (!counterstmp)
994 return -ENOMEM;
995 }
996
997 newinfo->chainstack = NULL;
998 ret = ebt_verify_pointers(repl, newinfo);
999 if (ret != 0)
1000 goto free_counterstmp;
1001
1002 ret = translate_table(net, repl->name, newinfo);
1003
1004 if (ret != 0)
1005 goto free_counterstmp;
1006
1007 t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
1008 if (!t) {
1009 ret = -ENOENT;
1010 goto free_iterate;
1011 }
1012
1013 /* the table doesn't like it */
1014 if (t->check && (ret = t->check(newinfo, repl->valid_hooks)))
1015 goto free_unlock;
1016
1017 if (repl->num_counters && repl->num_counters != t->private->nentries) {
1018 BUGPRINT("Wrong nr. of counters requested\n");
1019 ret = -EINVAL;
1020 goto free_unlock;
1021 }
1022
1023 /* we have the mutex lock, so no danger in reading this pointer */
1024 table = t->private;
1025 /* make sure the table can only be rmmod'ed if it contains no rules */
1026 if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) {
1027 ret = -ENOENT;
1028 goto free_unlock;
1029 } else if (table->nentries && !newinfo->nentries)
1030 module_put(t->me);
1031 /* we need an atomic snapshot of the counters */
1032 write_lock_bh(&t->lock);
1033 if (repl->num_counters)
1034 get_counters(t->private->counters, counterstmp,
1035 t->private->nentries);
1036
1037 t->private = newinfo;
1038 write_unlock_bh(&t->lock);
1039 mutex_unlock(&ebt_mutex);
1040 /* so, a user can change the chains while having messed up her counter
1041 allocation. Only reason why this is done is because this way the lock
1042 is held only once, while this doesn't bring the kernel into a
1043 dangerous state. */
1044 if (repl->num_counters &&
1045 copy_to_user(repl->counters, counterstmp,
1046 repl->num_counters * sizeof(struct ebt_counter))) {
1047 /* Silent error, can't fail, new table is already in place */
1048 net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n");
1049 }
1050
1051 /* decrease module count and free resources */
1052 EBT_ENTRY_ITERATE(table->entries, table->entries_size,
1053 ebt_cleanup_entry, net, NULL);
1054
1055 vfree(table->entries);
1056 if (table->chainstack) {
1057 for_each_possible_cpu(i)
1058 vfree(table->chainstack[i]);
1059 vfree(table->chainstack);
1060 }
1061 vfree(table);
1062
1063 vfree(counterstmp);
1064 return ret;
1065
1066 free_unlock:
1067 mutex_unlock(&ebt_mutex);
1068 free_iterate:
1069 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
1070 ebt_cleanup_entry, net, NULL);
1071 free_counterstmp:
1072 vfree(counterstmp);
1073 /* can be initialized in translate_table() */
1074 if (newinfo->chainstack) {
1075 for_each_possible_cpu(i)
1076 vfree(newinfo->chainstack[i]);
1077 vfree(newinfo->chainstack);
1078 }
1079 return ret;
1080 }
1081
1082 /* replace the table */
1083 static int do_replace(struct net *net, const void __user *user,
1084 unsigned int len)
1085 {
1086 int ret, countersize;
1087 struct ebt_table_info *newinfo;
1088 struct ebt_replace tmp;
1089
1090 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1091 return -EFAULT;
1092
1093 if (len != sizeof(tmp) + tmp.entries_size) {
1094 BUGPRINT("Wrong len argument\n");
1095 return -EINVAL;
1096 }
1097
1098 if (tmp.entries_size == 0) {
1099 BUGPRINT("Entries_size never zero\n");
1100 return -EINVAL;
1101 }
1102 /* overflow check */
1103 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
1104 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
1105 return -ENOMEM;
1106 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
1107 return -ENOMEM;
1108
1109 tmp.name[sizeof(tmp.name) - 1] = 0;
1110
1111 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
1112 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1113 if (!newinfo)
1114 return -ENOMEM;
1115
1116 if (countersize)
1117 memset(newinfo->counters, 0, countersize);
1118
1119 newinfo->entries = vmalloc(tmp.entries_size);
1120 if (!newinfo->entries) {
1121 ret = -ENOMEM;
1122 goto free_newinfo;
1123 }
1124 if (copy_from_user(
1125 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
1126 BUGPRINT("Couldn't copy entries from userspace\n");
1127 ret = -EFAULT;
1128 goto free_entries;
1129 }
1130
1131 ret = do_replace_finish(net, &tmp, newinfo);
1132 if (ret == 0)
1133 return ret;
1134 free_entries:
1135 vfree(newinfo->entries);
1136 free_newinfo:
1137 vfree(newinfo);
1138 return ret;
1139 }
1140
1141 struct ebt_table *
1142 ebt_register_table(struct net *net, const struct ebt_table *input_table)
1143 {
1144 struct ebt_table_info *newinfo;
1145 struct ebt_table *t, *table;
1146 struct ebt_replace_kernel *repl;
1147 int ret, i, countersize;
1148 void *p;
1149
1150 if (input_table == NULL || (repl = input_table->table) == NULL ||
1151 repl->entries == NULL || repl->entries_size == 0 ||
1152 repl->counters != NULL || input_table->private != NULL) {
1153 BUGPRINT("Bad table data for ebt_register_table!!!\n");
1154 return ERR_PTR(-EINVAL);
1155 }
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 BUGPRINT("Translate_table failed\n");
1195 goto free_chainstack;
1196 }
1197
1198 if (table->check && table->check(newinfo, table->valid_hooks)) {
1199 BUGPRINT("The table doesn't like its own initial data, lol\n");
1200 ret = -EINVAL;
1201 goto free_chainstack;
1202 }
1203
1204 table->private = newinfo;
1205 rwlock_init(&table->lock);
1206 ret = mutex_lock_interruptible(&ebt_mutex);
1207 if (ret != 0)
1208 goto free_chainstack;
1209
1210 list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
1211 if (strcmp(t->name, table->name) == 0) {
1212 ret = -EEXIST;
1213 BUGPRINT("Table name already exists\n");
1214 goto free_unlock;
1215 }
1216 }
1217
1218 /* Hold a reference count if the chains aren't empty */
1219 if (newinfo->nentries && !try_module_get(table->me)) {
1220 ret = -ENOENT;
1221 goto free_unlock;
1222 }
1223 list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
1224 mutex_unlock(&ebt_mutex);
1225 return table;
1226 free_unlock:
1227 mutex_unlock(&ebt_mutex);
1228 free_chainstack:
1229 if (newinfo->chainstack) {
1230 for_each_possible_cpu(i)
1231 vfree(newinfo->chainstack[i]);
1232 vfree(newinfo->chainstack);
1233 }
1234 vfree(newinfo->entries);
1235 free_newinfo:
1236 vfree(newinfo);
1237 free_table:
1238 kfree(table);
1239 out:
1240 return ERR_PTR(ret);
1241 }
1242
1243 void ebt_unregister_table(struct net *net, struct ebt_table *table)
1244 {
1245 int i;
1246
1247 if (!table) {
1248 BUGPRINT("Request to unregister NULL table!!!\n");
1249 return;
1250 }
1251 mutex_lock(&ebt_mutex);
1252 list_del(&table->list);
1253 mutex_unlock(&ebt_mutex);
1254 EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
1255 ebt_cleanup_entry, net, NULL);
1256 if (table->private->nentries)
1257 module_put(table->me);
1258 vfree(table->private->entries);
1259 if (table->private->chainstack) {
1260 for_each_possible_cpu(i)
1261 vfree(table->private->chainstack[i]);
1262 vfree(table->private->chainstack);
1263 }
1264 vfree(table->private);
1265 kfree(table);
1266 }
1267
1268 /* userspace just supplied us with counters */
1269 static int do_update_counters(struct net *net, const char *name,
1270 struct ebt_counter __user *counters,
1271 unsigned int num_counters,
1272 const void __user *user, unsigned int len)
1273 {
1274 int i, ret;
1275 struct ebt_counter *tmp;
1276 struct ebt_table *t;
1277
1278 if (num_counters == 0)
1279 return -EINVAL;
1280
1281 tmp = vmalloc(num_counters * sizeof(*tmp));
1282 if (!tmp)
1283 return -ENOMEM;
1284
1285 t = find_table_lock(net, name, &ret, &ebt_mutex);
1286 if (!t)
1287 goto free_tmp;
1288
1289 if (num_counters != t->private->nentries) {
1290 BUGPRINT("Wrong nr of counters\n");
1291 ret = -EINVAL;
1292 goto unlock_mutex;
1293 }
1294
1295 if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) {
1296 ret = -EFAULT;
1297 goto unlock_mutex;
1298 }
1299
1300 /* we want an atomic add of the counters */
1301 write_lock_bh(&t->lock);
1302
1303 /* we add to the counters of the first cpu */
1304 for (i = 0; i < num_counters; i++) {
1305 t->private->counters[i].pcnt += tmp[i].pcnt;
1306 t->private->counters[i].bcnt += tmp[i].bcnt;
1307 }
1308
1309 write_unlock_bh(&t->lock);
1310 ret = 0;
1311 unlock_mutex:
1312 mutex_unlock(&ebt_mutex);
1313 free_tmp:
1314 vfree(tmp);
1315 return ret;
1316 }
1317
1318 static int update_counters(struct net *net, const void __user *user,
1319 unsigned int len)
1320 {
1321 struct ebt_replace hlp;
1322
1323 if (copy_from_user(&hlp, user, sizeof(hlp)))
1324 return -EFAULT;
1325
1326 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
1327 return -EINVAL;
1328
1329 return do_update_counters(net, hlp.name, hlp.counters,
1330 hlp.num_counters, user, len);
1331 }
1332
1333 static inline int ebt_make_matchname(const struct ebt_entry_match *m,
1334 const char *base, char __user *ubase)
1335 {
1336 char __user *hlp = ubase + ((char *)m - base);
1337 char name[EBT_FUNCTION_MAXNAMELEN] = {};
1338
1339 /* ebtables expects 32 bytes long names but xt_match names are 29 bytes
1340 long. Copy 29 bytes and fill remaining bytes with zeroes. */
1341 strlcpy(name, m->u.match->name, sizeof(name));
1342 if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN))
1343 return -EFAULT;
1344 return 0;
1345 }
1346
1347 static inline int ebt_make_watchername(const struct ebt_entry_watcher *w,
1348 const char *base, char __user *ubase)
1349 {
1350 char __user *hlp = ubase + ((char *)w - base);
1351 char name[EBT_FUNCTION_MAXNAMELEN] = {};
1352
1353 strlcpy(name, w->u.watcher->name, sizeof(name));
1354 if (copy_to_user(hlp , name, EBT_FUNCTION_MAXNAMELEN))
1355 return -EFAULT;
1356 return 0;
1357 }
1358
1359 static inline int
1360 ebt_make_names(struct ebt_entry *e, const char *base, char __user *ubase)
1361 {
1362 int ret;
1363 char __user *hlp;
1364 const struct ebt_entry_target *t;
1365 char name[EBT_FUNCTION_MAXNAMELEN] = {};
1366
1367 if (e->bitmask == 0)
1368 return 0;
1369
1370 hlp = ubase + (((char *)e + e->target_offset) - base);
1371 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
1372
1373 ret = EBT_MATCH_ITERATE(e, ebt_make_matchname, base, ubase);
1374 if (ret != 0)
1375 return ret;
1376 ret = EBT_WATCHER_ITERATE(e, ebt_make_watchername, base, ubase);
1377 if (ret != 0)
1378 return ret;
1379 strlcpy(name, t->u.target->name, sizeof(name));
1380 if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN))
1381 return -EFAULT;
1382 return 0;
1383 }
1384
1385 static int copy_counters_to_user(struct ebt_table *t,
1386 const struct ebt_counter *oldcounters,
1387 void __user *user, unsigned int num_counters,
1388 unsigned int nentries)
1389 {
1390 struct ebt_counter *counterstmp;
1391 int ret = 0;
1392
1393 /* userspace might not need the counters */
1394 if (num_counters == 0)
1395 return 0;
1396
1397 if (num_counters != nentries) {
1398 BUGPRINT("Num_counters wrong\n");
1399 return -EINVAL;
1400 }
1401
1402 counterstmp = vmalloc(nentries * sizeof(*counterstmp));
1403 if (!counterstmp)
1404 return -ENOMEM;
1405
1406 write_lock_bh(&t->lock);
1407 get_counters(oldcounters, counterstmp, nentries);
1408 write_unlock_bh(&t->lock);
1409
1410 if (copy_to_user(user, counterstmp,
1411 nentries * sizeof(struct ebt_counter)))
1412 ret = -EFAULT;
1413 vfree(counterstmp);
1414 return ret;
1415 }
1416
1417 /* called with ebt_mutex locked */
1418 static int copy_everything_to_user(struct ebt_table *t, void __user *user,
1419 const int *len, int cmd)
1420 {
1421 struct ebt_replace tmp;
1422 const struct ebt_counter *oldcounters;
1423 unsigned int entries_size, nentries;
1424 int ret;
1425 char *entries;
1426
1427 if (cmd == EBT_SO_GET_ENTRIES) {
1428 entries_size = t->private->entries_size;
1429 nentries = t->private->nentries;
1430 entries = t->private->entries;
1431 oldcounters = t->private->counters;
1432 } else {
1433 entries_size = t->table->entries_size;
1434 nentries = t->table->nentries;
1435 entries = t->table->entries;
1436 oldcounters = t->table->counters;
1437 }
1438
1439 if (copy_from_user(&tmp, user, sizeof(tmp)))
1440 return -EFAULT;
1441
1442 if (*len != sizeof(struct ebt_replace) + entries_size +
1443 (tmp.num_counters? nentries * sizeof(struct ebt_counter): 0))
1444 return -EINVAL;
1445
1446 if (tmp.nentries != nentries) {
1447 BUGPRINT("Nentries wrong\n");
1448 return -EINVAL;
1449 }
1450
1451 if (tmp.entries_size != entries_size) {
1452 BUGPRINT("Wrong size\n");
1453 return -EINVAL;
1454 }
1455
1456 ret = copy_counters_to_user(t, oldcounters, tmp.counters,
1457 tmp.num_counters, nentries);
1458 if (ret)
1459 return ret;
1460
1461 if (copy_to_user(tmp.entries, entries, entries_size)) {
1462 BUGPRINT("Couldn't copy entries to userspace\n");
1463 return -EFAULT;
1464 }
1465 /* set the match/watcher/target names right */
1466 return EBT_ENTRY_ITERATE(entries, entries_size,
1467 ebt_make_names, entries, tmp.entries);
1468 }
1469
1470 static int do_ebt_set_ctl(struct sock *sk,
1471 int cmd, void __user *user, unsigned int len)
1472 {
1473 int ret;
1474 struct net *net = sock_net(sk);
1475
1476 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1477 return -EPERM;
1478
1479 switch(cmd) {
1480 case EBT_SO_SET_ENTRIES:
1481 ret = do_replace(net, user, len);
1482 break;
1483 case EBT_SO_SET_COUNTERS:
1484 ret = update_counters(net, user, len);
1485 break;
1486 default:
1487 ret = -EINVAL;
1488 }
1489 return ret;
1490 }
1491
1492 static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1493 {
1494 int ret;
1495 struct ebt_replace tmp;
1496 struct ebt_table *t;
1497 struct net *net = sock_net(sk);
1498
1499 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1500 return -EPERM;
1501
1502 if (copy_from_user(&tmp, user, sizeof(tmp)))
1503 return -EFAULT;
1504
1505 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
1506 if (!t)
1507 return ret;
1508
1509 switch(cmd) {
1510 case EBT_SO_GET_INFO:
1511 case EBT_SO_GET_INIT_INFO:
1512 if (*len != sizeof(struct ebt_replace)){
1513 ret = -EINVAL;
1514 mutex_unlock(&ebt_mutex);
1515 break;
1516 }
1517 if (cmd == EBT_SO_GET_INFO) {
1518 tmp.nentries = t->private->nentries;
1519 tmp.entries_size = t->private->entries_size;
1520 tmp.valid_hooks = t->valid_hooks;
1521 } else {
1522 tmp.nentries = t->table->nentries;
1523 tmp.entries_size = t->table->entries_size;
1524 tmp.valid_hooks = t->table->valid_hooks;
1525 }
1526 mutex_unlock(&ebt_mutex);
1527 if (copy_to_user(user, &tmp, *len) != 0){
1528 BUGPRINT("c2u Didn't work\n");
1529 ret = -EFAULT;
1530 break;
1531 }
1532 ret = 0;
1533 break;
1534
1535 case EBT_SO_GET_ENTRIES:
1536 case EBT_SO_GET_INIT_ENTRIES:
1537 ret = copy_everything_to_user(t, user, len, cmd);
1538 mutex_unlock(&ebt_mutex);
1539 break;
1540
1541 default:
1542 mutex_unlock(&ebt_mutex);
1543 ret = -EINVAL;
1544 }
1545
1546 return ret;
1547 }
1548
1549 #ifdef CONFIG_COMPAT
1550 /* 32 bit-userspace compatibility definitions. */
1551 struct compat_ebt_replace {
1552 char name[EBT_TABLE_MAXNAMELEN];
1553 compat_uint_t valid_hooks;
1554 compat_uint_t nentries;
1555 compat_uint_t entries_size;
1556 /* start of the chains */
1557 compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
1558 /* nr of counters userspace expects back */
1559 compat_uint_t num_counters;
1560 /* where the kernel will put the old counters. */
1561 compat_uptr_t counters;
1562 compat_uptr_t entries;
1563 };
1564
1565 /* struct ebt_entry_match, _target and _watcher have same layout */
1566 struct compat_ebt_entry_mwt {
1567 union {
1568 char name[EBT_FUNCTION_MAXNAMELEN];
1569 compat_uptr_t ptr;
1570 } u;
1571 compat_uint_t match_size;
1572 compat_uint_t data[0];
1573 };
1574
1575 /* account for possible padding between match_size and ->data */
1576 static int ebt_compat_entry_padsize(void)
1577 {
1578 BUILD_BUG_ON(XT_ALIGN(sizeof(struct ebt_entry_match)) <
1579 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt)));
1580 return (int) XT_ALIGN(sizeof(struct ebt_entry_match)) -
1581 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt));
1582 }
1583
1584 static int ebt_compat_match_offset(const struct xt_match *match,
1585 unsigned int userlen)
1586 {
1587 /*
1588 * ebt_among needs special handling. The kernel .matchsize is
1589 * set to -1 at registration time; at runtime an EBT_ALIGN()ed
1590 * value is expected.
1591 * Example: userspace sends 4500, ebt_among.c wants 4504.
1592 */
1593 if (unlikely(match->matchsize == -1))
1594 return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
1595 return xt_compat_match_offset(match);
1596 }
1597
1598 static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
1599 unsigned int *size)
1600 {
1601 const struct xt_match *match = m->u.match;
1602 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1603 int off = ebt_compat_match_offset(match, m->match_size);
1604 compat_uint_t msize = m->match_size - off;
1605
1606 BUG_ON(off >= m->match_size);
1607
1608 if (copy_to_user(cm->u.name, match->name,
1609 strlen(match->name) + 1) || put_user(msize, &cm->match_size))
1610 return -EFAULT;
1611
1612 if (match->compat_to_user) {
1613 if (match->compat_to_user(cm->data, m->data))
1614 return -EFAULT;
1615 } else if (copy_to_user(cm->data, m->data, msize))
1616 return -EFAULT;
1617
1618 *size -= ebt_compat_entry_padsize() + off;
1619 *dstptr = cm->data;
1620 *dstptr += msize;
1621 return 0;
1622 }
1623
1624 static int compat_target_to_user(struct ebt_entry_target *t,
1625 void __user **dstptr,
1626 unsigned int *size)
1627 {
1628 const struct xt_target *target = t->u.target;
1629 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1630 int off = xt_compat_target_offset(target);
1631 compat_uint_t tsize = t->target_size - off;
1632
1633 BUG_ON(off >= t->target_size);
1634
1635 if (copy_to_user(cm->u.name, target->name,
1636 strlen(target->name) + 1) || put_user(tsize, &cm->match_size))
1637 return -EFAULT;
1638
1639 if (target->compat_to_user) {
1640 if (target->compat_to_user(cm->data, t->data))
1641 return -EFAULT;
1642 } else if (copy_to_user(cm->data, t->data, tsize))
1643 return -EFAULT;
1644
1645 *size -= ebt_compat_entry_padsize() + off;
1646 *dstptr = cm->data;
1647 *dstptr += tsize;
1648 return 0;
1649 }
1650
1651 static int compat_watcher_to_user(struct ebt_entry_watcher *w,
1652 void __user **dstptr,
1653 unsigned int *size)
1654 {
1655 return compat_target_to_user((struct ebt_entry_target *)w,
1656 dstptr, size);
1657 }
1658
1659 static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
1660 unsigned int *size)
1661 {
1662 struct ebt_entry_target *t;
1663 struct ebt_entry __user *ce;
1664 u32 watchers_offset, target_offset, next_offset;
1665 compat_uint_t origsize;
1666 int ret;
1667
1668 if (e->bitmask == 0) {
1669 if (*size < sizeof(struct ebt_entries))
1670 return -EINVAL;
1671 if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries)))
1672 return -EFAULT;
1673
1674 *dstptr += sizeof(struct ebt_entries);
1675 *size -= sizeof(struct ebt_entries);
1676 return 0;
1677 }
1678
1679 if (*size < sizeof(*ce))
1680 return -EINVAL;
1681
1682 ce = (struct ebt_entry __user *)*dstptr;
1683 if (copy_to_user(ce, e, sizeof(*ce)))
1684 return -EFAULT;
1685
1686 origsize = *size;
1687 *dstptr += sizeof(*ce);
1688
1689 ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
1690 if (ret)
1691 return ret;
1692 watchers_offset = e->watchers_offset - (origsize - *size);
1693
1694 ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
1695 if (ret)
1696 return ret;
1697 target_offset = e->target_offset - (origsize - *size);
1698
1699 t = (struct ebt_entry_target *) ((char *) e + e->target_offset);
1700
1701 ret = compat_target_to_user(t, dstptr, size);
1702 if (ret)
1703 return ret;
1704 next_offset = e->next_offset - (origsize - *size);
1705
1706 if (put_user(watchers_offset, &ce->watchers_offset) ||
1707 put_user(target_offset, &ce->target_offset) ||
1708 put_user(next_offset, &ce->next_offset))
1709 return -EFAULT;
1710
1711 *size -= sizeof(*ce);
1712 return 0;
1713 }
1714
1715 static int compat_calc_match(struct ebt_entry_match *m, int *off)
1716 {
1717 *off += ebt_compat_match_offset(m->u.match, m->match_size);
1718 *off += ebt_compat_entry_padsize();
1719 return 0;
1720 }
1721
1722 static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
1723 {
1724 *off += xt_compat_target_offset(w->u.watcher);
1725 *off += ebt_compat_entry_padsize();
1726 return 0;
1727 }
1728
1729 static int compat_calc_entry(const struct ebt_entry *e,
1730 const struct ebt_table_info *info,
1731 const void *base,
1732 struct compat_ebt_replace *newinfo)
1733 {
1734 const struct ebt_entry_target *t;
1735 unsigned int entry_offset;
1736 int off, ret, i;
1737
1738 if (e->bitmask == 0)
1739 return 0;
1740
1741 off = 0;
1742 entry_offset = (void *)e - base;
1743
1744 EBT_MATCH_ITERATE(e, compat_calc_match, &off);
1745 EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
1746
1747 t = (const struct ebt_entry_target *) ((char *) e + e->target_offset);
1748
1749 off += xt_compat_target_offset(t->u.target);
1750 off += ebt_compat_entry_padsize();
1751
1752 newinfo->entries_size -= off;
1753
1754 ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off);
1755 if (ret)
1756 return ret;
1757
1758 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1759 const void *hookptr = info->hook_entry[i];
1760 if (info->hook_entry[i] &&
1761 (e < (struct ebt_entry *)(base - hookptr))) {
1762 newinfo->hook_entry[i] -= off;
1763 pr_debug("0x%08X -> 0x%08X\n",
1764 newinfo->hook_entry[i] + off,
1765 newinfo->hook_entry[i]);
1766 }
1767 }
1768
1769 return 0;
1770 }
1771
1772
1773 static int compat_table_info(const struct ebt_table_info *info,
1774 struct compat_ebt_replace *newinfo)
1775 {
1776 unsigned int size = info->entries_size;
1777 const void *entries = info->entries;
1778
1779 newinfo->entries_size = size;
1780
1781 xt_compat_init_offsets(NFPROTO_BRIDGE, info->nentries);
1782 return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
1783 entries, newinfo);
1784 }
1785
1786 static int compat_copy_everything_to_user(struct ebt_table *t,
1787 void __user *user, int *len, int cmd)
1788 {
1789 struct compat_ebt_replace repl, tmp;
1790 struct ebt_counter *oldcounters;
1791 struct ebt_table_info tinfo;
1792 int ret;
1793 void __user *pos;
1794
1795 memset(&tinfo, 0, sizeof(tinfo));
1796
1797 if (cmd == EBT_SO_GET_ENTRIES) {
1798 tinfo.entries_size = t->private->entries_size;
1799 tinfo.nentries = t->private->nentries;
1800 tinfo.entries = t->private->entries;
1801 oldcounters = t->private->counters;
1802 } else {
1803 tinfo.entries_size = t->table->entries_size;
1804 tinfo.nentries = t->table->nentries;
1805 tinfo.entries = t->table->entries;
1806 oldcounters = t->table->counters;
1807 }
1808
1809 if (copy_from_user(&tmp, user, sizeof(tmp)))
1810 return -EFAULT;
1811
1812 if (tmp.nentries != tinfo.nentries ||
1813 (tmp.num_counters && tmp.num_counters != tinfo.nentries))
1814 return -EINVAL;
1815
1816 memcpy(&repl, &tmp, sizeof(repl));
1817 if (cmd == EBT_SO_GET_ENTRIES)
1818 ret = compat_table_info(t->private, &repl);
1819 else
1820 ret = compat_table_info(&tinfo, &repl);
1821 if (ret)
1822 return ret;
1823
1824 if (*len != sizeof(tmp) + repl.entries_size +
1825 (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
1826 pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
1827 *len, tinfo.entries_size, repl.entries_size);
1828 return -EINVAL;
1829 }
1830
1831 /* userspace might not need the counters */
1832 ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters),
1833 tmp.num_counters, tinfo.nentries);
1834 if (ret)
1835 return ret;
1836
1837 pos = compat_ptr(tmp.entries);
1838 return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
1839 compat_copy_entry_to_user, &pos, &tmp.entries_size);
1840 }
1841
1842 struct ebt_entries_buf_state {
1843 char *buf_kern_start; /* kernel buffer to copy (translated) data to */
1844 u32 buf_kern_len; /* total size of kernel buffer */
1845 u32 buf_kern_offset; /* amount of data copied so far */
1846 u32 buf_user_offset; /* read position in userspace buffer */
1847 };
1848
1849 static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
1850 {
1851 state->buf_kern_offset += sz;
1852 return state->buf_kern_offset >= sz ? 0 : -EINVAL;
1853 }
1854
1855 static int ebt_buf_add(struct ebt_entries_buf_state *state,
1856 void *data, unsigned int sz)
1857 {
1858 if (state->buf_kern_start == NULL)
1859 goto count_only;
1860
1861 BUG_ON(state->buf_kern_offset + sz > state->buf_kern_len);
1862
1863 memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz);
1864
1865 count_only:
1866 state->buf_user_offset += sz;
1867 return ebt_buf_count(state, sz);
1868 }
1869
1870 static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz)
1871 {
1872 char *b = state->buf_kern_start;
1873
1874 BUG_ON(b && state->buf_kern_offset > state->buf_kern_len);
1875
1876 if (b != NULL && sz > 0)
1877 memset(b + state->buf_kern_offset, 0, sz);
1878 /* do not adjust ->buf_user_offset here, we added kernel-side padding */
1879 return ebt_buf_count(state, sz);
1880 }
1881
1882 enum compat_mwt {
1883 EBT_COMPAT_MATCH,
1884 EBT_COMPAT_WATCHER,
1885 EBT_COMPAT_TARGET,
1886 };
1887
1888 static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt,
1889 enum compat_mwt compat_mwt,
1890 struct ebt_entries_buf_state *state,
1891 const unsigned char *base)
1892 {
1893 char name[EBT_FUNCTION_MAXNAMELEN];
1894 struct xt_match *match;
1895 struct xt_target *wt;
1896 void *dst = NULL;
1897 int off, pad = 0;
1898 unsigned int size_kern, match_size = mwt->match_size;
1899
1900 strlcpy(name, mwt->u.name, sizeof(name));
1901
1902 if (state->buf_kern_start)
1903 dst = state->buf_kern_start + state->buf_kern_offset;
1904
1905 switch (compat_mwt) {
1906 case EBT_COMPAT_MATCH:
1907 match = xt_request_find_match(NFPROTO_BRIDGE, name, 0);
1908 if (IS_ERR(match))
1909 return PTR_ERR(match);
1910
1911 off = ebt_compat_match_offset(match, match_size);
1912 if (dst) {
1913 if (match->compat_from_user)
1914 match->compat_from_user(dst, mwt->data);
1915 else
1916 memcpy(dst, mwt->data, match_size);
1917 }
1918
1919 size_kern = match->matchsize;
1920 if (unlikely(size_kern == -1))
1921 size_kern = match_size;
1922 module_put(match->me);
1923 break;
1924 case EBT_COMPAT_WATCHER: /* fallthrough */
1925 case EBT_COMPAT_TARGET:
1926 wt = xt_request_find_target(NFPROTO_BRIDGE, name, 0);
1927 if (IS_ERR(wt))
1928 return PTR_ERR(wt);
1929 off = xt_compat_target_offset(wt);
1930
1931 if (dst) {
1932 if (wt->compat_from_user)
1933 wt->compat_from_user(dst, mwt->data);
1934 else
1935 memcpy(dst, mwt->data, match_size);
1936 }
1937
1938 size_kern = wt->targetsize;
1939 module_put(wt->me);
1940 break;
1941
1942 default:
1943 return -EINVAL;
1944 }
1945
1946 state->buf_kern_offset += match_size + off;
1947 state->buf_user_offset += match_size;
1948 pad = XT_ALIGN(size_kern) - size_kern;
1949
1950 if (pad > 0 && dst) {
1951 BUG_ON(state->buf_kern_len <= pad);
1952 BUG_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad);
1953 memset(dst + size_kern, 0, pad);
1954 }
1955 return off + match_size;
1956 }
1957
1958 /*
1959 * return size of all matches, watchers or target, including necessary
1960 * alignment and padding.
1961 */
1962 static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32,
1963 unsigned int size_left, enum compat_mwt type,
1964 struct ebt_entries_buf_state *state, const void *base)
1965 {
1966 int growth = 0;
1967 char *buf;
1968
1969 if (size_left == 0)
1970 return 0;
1971
1972 buf = (char *) match32;
1973
1974 while (size_left >= sizeof(*match32)) {
1975 struct ebt_entry_match *match_kern;
1976 int ret;
1977
1978 match_kern = (struct ebt_entry_match *) state->buf_kern_start;
1979 if (match_kern) {
1980 char *tmp;
1981 tmp = state->buf_kern_start + state->buf_kern_offset;
1982 match_kern = (struct ebt_entry_match *) tmp;
1983 }
1984 ret = ebt_buf_add(state, buf, sizeof(*match32));
1985 if (ret < 0)
1986 return ret;
1987 size_left -= sizeof(*match32);
1988
1989 /* add padding before match->data (if any) */
1990 ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize());
1991 if (ret < 0)
1992 return ret;
1993
1994 if (match32->match_size > size_left)
1995 return -EINVAL;
1996
1997 size_left -= match32->match_size;
1998
1999 ret = compat_mtw_from_user(match32, type, state, base);
2000 if (ret < 0)
2001 return ret;
2002
2003 BUG_ON(ret < match32->match_size);
2004 growth += ret - match32->match_size;
2005 growth += ebt_compat_entry_padsize();
2006
2007 buf += sizeof(*match32);
2008 buf += match32->match_size;
2009
2010 if (match_kern)
2011 match_kern->match_size = ret;
2012
2013 WARN_ON(type == EBT_COMPAT_TARGET && size_left);
2014 match32 = (struct compat_ebt_entry_mwt *) buf;
2015 }
2016
2017 return growth;
2018 }
2019
2020 /* called for all ebt_entry structures. */
2021 static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,
2022 unsigned int *total,
2023 struct ebt_entries_buf_state *state)
2024 {
2025 unsigned int i, j, startoff, new_offset = 0;
2026 /* stores match/watchers/targets & offset of next struct ebt_entry: */
2027 unsigned int offsets[4];
2028 unsigned int *offsets_update = NULL;
2029 int ret;
2030 char *buf_start;
2031
2032 if (*total < sizeof(struct ebt_entries))
2033 return -EINVAL;
2034
2035 if (!entry->bitmask) {
2036 *total -= sizeof(struct ebt_entries);
2037 return ebt_buf_add(state, entry, sizeof(struct ebt_entries));
2038 }
2039 if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
2040 return -EINVAL;
2041
2042 startoff = state->buf_user_offset;
2043 /* pull in most part of ebt_entry, it does not need to be changed. */
2044 ret = ebt_buf_add(state, entry,
2045 offsetof(struct ebt_entry, watchers_offset));
2046 if (ret < 0)
2047 return ret;
2048
2049 offsets[0] = sizeof(struct ebt_entry); /* matches come first */
2050 memcpy(&offsets[1], &entry->watchers_offset,
2051 sizeof(offsets) - sizeof(offsets[0]));
2052
2053 if (state->buf_kern_start) {
2054 buf_start = state->buf_kern_start + state->buf_kern_offset;
2055 offsets_update = (unsigned int *) buf_start;
2056 }
2057 ret = ebt_buf_add(state, &offsets[1],
2058 sizeof(offsets) - sizeof(offsets[0]));
2059 if (ret < 0)
2060 return ret;
2061 buf_start = (char *) entry;
2062 /*
2063 * 0: matches offset, always follows ebt_entry.
2064 * 1: watchers offset, from ebt_entry structure
2065 * 2: target offset, from ebt_entry structure
2066 * 3: next ebt_entry offset, from ebt_entry structure
2067 *
2068 * offsets are relative to beginning of struct ebt_entry (i.e., 0).
2069 */
2070 for (i = 0, j = 1 ; j < 4 ; j++, i++) {
2071 struct compat_ebt_entry_mwt *match32;
2072 unsigned int size;
2073 char *buf = buf_start;
2074
2075 buf = buf_start + offsets[i];
2076 if (offsets[i] > offsets[j])
2077 return -EINVAL;
2078
2079 match32 = (struct compat_ebt_entry_mwt *) buf;
2080 size = offsets[j] - offsets[i];
2081 ret = ebt_size_mwt(match32, size, i, state, base);
2082 if (ret < 0)
2083 return ret;
2084 new_offset += ret;
2085 if (offsets_update && new_offset) {
2086 pr_debug("change offset %d to %d\n",
2087 offsets_update[i], offsets[j] + new_offset);
2088 offsets_update[i] = offsets[j] + new_offset;
2089 }
2090 }
2091
2092 if (state->buf_kern_start == NULL) {
2093 unsigned int offset = buf_start - (char *) base;
2094
2095 ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);
2096 if (ret < 0)
2097 return ret;
2098 }
2099
2100 startoff = state->buf_user_offset - startoff;
2101
2102 BUG_ON(*total < startoff);
2103 *total -= startoff;
2104 return 0;
2105 }
2106
2107 /*
2108 * repl->entries_size is the size of the ebt_entry blob in userspace.
2109 * It might need more memory when copied to a 64 bit kernel in case
2110 * userspace is 32-bit. So, first task: find out how much memory is needed.
2111 *
2112 * Called before validation is performed.
2113 */
2114 static int compat_copy_entries(unsigned char *data, unsigned int size_user,
2115 struct ebt_entries_buf_state *state)
2116 {
2117 unsigned int size_remaining = size_user;
2118 int ret;
2119
2120 ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
2121 &size_remaining, state);
2122 if (ret < 0)
2123 return ret;
2124
2125 WARN_ON(size_remaining);
2126 return state->buf_kern_offset;
2127 }
2128
2129
2130 static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
2131 void __user *user, unsigned int len)
2132 {
2133 struct compat_ebt_replace tmp;
2134 int i;
2135
2136 if (len < sizeof(tmp))
2137 return -EINVAL;
2138
2139 if (copy_from_user(&tmp, user, sizeof(tmp)))
2140 return -EFAULT;
2141
2142 if (len != sizeof(tmp) + tmp.entries_size)
2143 return -EINVAL;
2144
2145 if (tmp.entries_size == 0)
2146 return -EINVAL;
2147
2148 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
2149 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
2150 return -ENOMEM;
2151 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
2152 return -ENOMEM;
2153
2154 memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
2155
2156 /* starting with hook_entry, 32 vs. 64 bit structures are different */
2157 for (i = 0; i < NF_BR_NUMHOOKS; i++)
2158 repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]);
2159
2160 repl->num_counters = tmp.num_counters;
2161 repl->counters = compat_ptr(tmp.counters);
2162 repl->entries = compat_ptr(tmp.entries);
2163 return 0;
2164 }
2165
2166 static int compat_do_replace(struct net *net, void __user *user,
2167 unsigned int len)
2168 {
2169 int ret, i, countersize, size64;
2170 struct ebt_table_info *newinfo;
2171 struct ebt_replace tmp;
2172 struct ebt_entries_buf_state state;
2173 void *entries_tmp;
2174
2175 ret = compat_copy_ebt_replace_from_user(&tmp, user, len);
2176 if (ret) {
2177 /* try real handler in case userland supplied needed padding */
2178 if (ret == -EINVAL && do_replace(net, user, len) == 0)
2179 ret = 0;
2180 return ret;
2181 }
2182
2183 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
2184 newinfo = vmalloc(sizeof(*newinfo) + countersize);
2185 if (!newinfo)
2186 return -ENOMEM;
2187
2188 if (countersize)
2189 memset(newinfo->counters, 0, countersize);
2190
2191 memset(&state, 0, sizeof(state));
2192
2193 newinfo->entries = vmalloc(tmp.entries_size);
2194 if (!newinfo->entries) {
2195 ret = -ENOMEM;
2196 goto free_newinfo;
2197 }
2198 if (copy_from_user(
2199 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
2200 ret = -EFAULT;
2201 goto free_entries;
2202 }
2203
2204 entries_tmp = newinfo->entries;
2205
2206 xt_compat_lock(NFPROTO_BRIDGE);
2207
2208 xt_compat_init_offsets(NFPROTO_BRIDGE, tmp.nentries);
2209 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2210 if (ret < 0)
2211 goto out_unlock;
2212
2213 pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
2214 tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
2215 xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
2216
2217 size64 = ret;
2218 newinfo->entries = vmalloc(size64);
2219 if (!newinfo->entries) {
2220 vfree(entries_tmp);
2221 ret = -ENOMEM;
2222 goto out_unlock;
2223 }
2224
2225 memset(&state, 0, sizeof(state));
2226 state.buf_kern_start = newinfo->entries;
2227 state.buf_kern_len = size64;
2228
2229 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2230 BUG_ON(ret < 0); /* parses same data again */
2231
2232 vfree(entries_tmp);
2233 tmp.entries_size = size64;
2234
2235 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
2236 char __user *usrptr;
2237 if (tmp.hook_entry[i]) {
2238 unsigned int delta;
2239 usrptr = (char __user *) tmp.hook_entry[i];
2240 delta = usrptr - tmp.entries;
2241 usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta);
2242 tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
2243 }
2244 }
2245
2246 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2247 xt_compat_unlock(NFPROTO_BRIDGE);
2248
2249 ret = do_replace_finish(net, &tmp, newinfo);
2250 if (ret == 0)
2251 return ret;
2252 free_entries:
2253 vfree(newinfo->entries);
2254 free_newinfo:
2255 vfree(newinfo);
2256 return ret;
2257 out_unlock:
2258 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2259 xt_compat_unlock(NFPROTO_BRIDGE);
2260 goto free_entries;
2261 }
2262
2263 static int compat_update_counters(struct net *net, void __user *user,
2264 unsigned int len)
2265 {
2266 struct compat_ebt_replace hlp;
2267
2268 if (copy_from_user(&hlp, user, sizeof(hlp)))
2269 return -EFAULT;
2270
2271 /* try real handler in case userland supplied needed padding */
2272 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
2273 return update_counters(net, user, len);
2274
2275 return do_update_counters(net, hlp.name, compat_ptr(hlp.counters),
2276 hlp.num_counters, user, len);
2277 }
2278
2279 static int compat_do_ebt_set_ctl(struct sock *sk,
2280 int cmd, void __user *user, unsigned int len)
2281 {
2282 int ret;
2283 struct net *net = sock_net(sk);
2284
2285 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2286 return -EPERM;
2287
2288 switch (cmd) {
2289 case EBT_SO_SET_ENTRIES:
2290 ret = compat_do_replace(net, user, len);
2291 break;
2292 case EBT_SO_SET_COUNTERS:
2293 ret = compat_update_counters(net, user, len);
2294 break;
2295 default:
2296 ret = -EINVAL;
2297 }
2298 return ret;
2299 }
2300
2301 static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
2302 void __user *user, int *len)
2303 {
2304 int ret;
2305 struct compat_ebt_replace tmp;
2306 struct ebt_table *t;
2307 struct net *net = sock_net(sk);
2308
2309 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2310 return -EPERM;
2311
2312 /* try real handler in case userland supplied needed padding */
2313 if ((cmd == EBT_SO_GET_INFO ||
2314 cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp))
2315 return do_ebt_get_ctl(sk, cmd, user, len);
2316
2317 if (copy_from_user(&tmp, user, sizeof(tmp)))
2318 return -EFAULT;
2319
2320 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
2321 if (!t)
2322 return ret;
2323
2324 xt_compat_lock(NFPROTO_BRIDGE);
2325 switch (cmd) {
2326 case EBT_SO_GET_INFO:
2327 tmp.nentries = t->private->nentries;
2328 ret = compat_table_info(t->private, &tmp);
2329 if (ret)
2330 goto out;
2331 tmp.valid_hooks = t->valid_hooks;
2332
2333 if (copy_to_user(user, &tmp, *len) != 0) {
2334 ret = -EFAULT;
2335 break;
2336 }
2337 ret = 0;
2338 break;
2339 case EBT_SO_GET_INIT_INFO:
2340 tmp.nentries = t->table->nentries;
2341 tmp.entries_size = t->table->entries_size;
2342 tmp.valid_hooks = t->table->valid_hooks;
2343
2344 if (copy_to_user(user, &tmp, *len) != 0) {
2345 ret = -EFAULT;
2346 break;
2347 }
2348 ret = 0;
2349 break;
2350 case EBT_SO_GET_ENTRIES:
2351 case EBT_SO_GET_INIT_ENTRIES:
2352 /*
2353 * try real handler first in case of userland-side padding.
2354 * in case we are dealing with an 'ordinary' 32 bit binary
2355 * without 64bit compatibility padding, this will fail right
2356 * after copy_from_user when the *len argument is validated.
2357 *
2358 * the compat_ variant needs to do one pass over the kernel
2359 * data set to adjust for size differences before it the check.
2360 */
2361 if (copy_everything_to_user(t, user, len, cmd) == 0)
2362 ret = 0;
2363 else
2364 ret = compat_copy_everything_to_user(t, user, len, cmd);
2365 break;
2366 default:
2367 ret = -EINVAL;
2368 }
2369 out:
2370 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2371 xt_compat_unlock(NFPROTO_BRIDGE);
2372 mutex_unlock(&ebt_mutex);
2373 return ret;
2374 }
2375 #endif
2376
2377 static struct nf_sockopt_ops ebt_sockopts =
2378 {
2379 .pf = PF_INET,
2380 .set_optmin = EBT_BASE_CTL,
2381 .set_optmax = EBT_SO_SET_MAX + 1,
2382 .set = do_ebt_set_ctl,
2383 #ifdef CONFIG_COMPAT
2384 .compat_set = compat_do_ebt_set_ctl,
2385 #endif
2386 .get_optmin = EBT_BASE_CTL,
2387 .get_optmax = EBT_SO_GET_MAX + 1,
2388 .get = do_ebt_get_ctl,
2389 #ifdef CONFIG_COMPAT
2390 .compat_get = compat_do_ebt_get_ctl,
2391 #endif
2392 .owner = THIS_MODULE,
2393 };
2394
2395 static int __init ebtables_init(void)
2396 {
2397 int ret;
2398
2399 ret = xt_register_target(&ebt_standard_target);
2400 if (ret < 0)
2401 return ret;
2402 ret = nf_register_sockopt(&ebt_sockopts);
2403 if (ret < 0) {
2404 xt_unregister_target(&ebt_standard_target);
2405 return ret;
2406 }
2407
2408 printk(KERN_INFO "Ebtables v2.0 registered\n");
2409 return 0;
2410 }
2411
2412 static void __exit ebtables_fini(void)
2413 {
2414 nf_unregister_sockopt(&ebt_sockopts);
2415 xt_unregister_target(&ebt_standard_target);
2416 printk(KERN_INFO "Ebtables v2.0 unregistered\n");
2417 }
2418
2419 EXPORT_SYMBOL(ebt_register_table);
2420 EXPORT_SYMBOL(ebt_unregister_table);
2421 EXPORT_SYMBOL(ebt_do_table);
2422 module_init(ebtables_init);
2423 module_exit(ebtables_fini);
2424 MODULE_LICENSE("GPL");
Linux with added FPC-III support