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powerpc/powernv: Report size of OPAL memcons log
[linux/fpc-iii.git] / net / bridge / netfilter / ebtables.c
blob537e3d506fc237f673af53a50109fea6935872ff
1 /*
2 * ebtables
3 *
4 * Author:
5 * Bart De Schuymer <bdschuym@pandora.be>
6 *
7 * ebtables.c,v 2.0, July, 2002
8 *
9 * This code is strongly inspired by the iptables code which is
10 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/kmod.h>
19 #include <linux/module.h>
20 #include <linux/vmalloc.h>
21 #include <linux/netfilter/x_tables.h>
22 #include <linux/netfilter_bridge/ebtables.h>
23 #include <linux/spinlock.h>
24 #include <linux/mutex.h>
25 #include <linux/slab.h>
26 #include <linux/uaccess.h>
27 #include <linux/smp.h>
28 #include <linux/cpumask.h>
29 #include <linux/audit.h>
30 #include <net/sock.h>
31 /* needed for logical [in,out]-dev filtering */
32 #include "../br_private.h"
33
34 #define BUGPRINT(format, args...) printk("kernel msg: ebtables bug: please "\
35 "report to author: "format, ## args)
36 /* #define BUGPRINT(format, args...) */
37
38 /* Each cpu has its own set of counters, so there is no need for write_lock in
39 * the softirq
40 * For reading or updating the counters, the user context needs to
41 * get a write_lock
42 */
43
44 /* The size of each set of counters is altered to get cache alignment */
45 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
46 #define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter)))
47 #define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \
48 COUNTER_OFFSET(n) * cpu))
49
50
51
52 static DEFINE_MUTEX(ebt_mutex);
53
54 #ifdef CONFIG_COMPAT
55 static void ebt_standard_compat_from_user(void *dst, const void *src)
56 {
57 int v = *(compat_int_t *)src;
58
59 if (v >= 0)
60 v += xt_compat_calc_jump(NFPROTO_BRIDGE, v);
61 memcpy(dst, &v, sizeof(v));
62 }
63
64 static int ebt_standard_compat_to_user(void __user *dst, const void *src)
65 {
66 compat_int_t cv = *(int *)src;
67
68 if (cv >= 0)
69 cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv);
70 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
71 }
72 #endif
73
74
75 static struct xt_target ebt_standard_target = {
76 .name = "standard",
77 .revision = 0,
78 .family = NFPROTO_BRIDGE,
79 .targetsize = sizeof(int),
80 #ifdef CONFIG_COMPAT
81 .compatsize = sizeof(compat_int_t),
82 .compat_from_user = ebt_standard_compat_from_user,
83 .compat_to_user = ebt_standard_compat_to_user,
84 #endif
85 };
86
87 static inline int
88 ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb,
89 struct xt_action_param *par)
90 {
91 par->target = w->u.watcher;
92 par->targinfo = w->data;
93 w->u.watcher->target(skb, par);
94 /* watchers don't give a verdict */
95 return 0;
96 }
97
98 static inline int
99 ebt_do_match(struct ebt_entry_match *m, const struct sk_buff *skb,
100 struct xt_action_param *par)
101 {
102 par->match = m->u.match;
103 par->matchinfo = m->data;
104 return m->u.match->match(skb, par) ? EBT_MATCH : EBT_NOMATCH;
105 }
106
107 static inline int
108 ebt_dev_check(const char *entry, const struct net_device *device)
109 {
110 int i = 0;
111 const char *devname;
112
113 if (*entry == '\0')
114 return 0;
115 if (!device)
116 return 1;
117 devname = device->name;
118 /* 1 is the wildcard token */
119 while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i])
120 i++;
121 return devname[i] != entry[i] && entry[i] != 1;
122 }
123
124 /* process standard matches */
125 static inline int
126 ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb,
127 const struct net_device *in, const struct net_device *out)
128 {
129 const struct ethhdr *h = eth_hdr(skb);
130 const struct net_bridge_port *p;
131 __be16 ethproto;
132
133 if (skb_vlan_tag_present(skb))
134 ethproto = htons(ETH_P_8021Q);
135 else
136 ethproto = h->h_proto;
137
138 if (e->bitmask & EBT_802_3) {
139 if (NF_INVF(e, EBT_IPROTO, eth_proto_is_802_3(ethproto)))
140 return 1;
141 } else if (!(e->bitmask & EBT_NOPROTO) &&
142 NF_INVF(e, EBT_IPROTO, e->ethproto != ethproto))
143 return 1;
144
145 if (NF_INVF(e, EBT_IIN, ebt_dev_check(e->in, in)))
146 return 1;
147 if (NF_INVF(e, EBT_IOUT, ebt_dev_check(e->out, out)))
148 return 1;
149 /* rcu_read_lock()ed by nf_hook_thresh */
150 if (in && (p = br_port_get_rcu(in)) != NULL &&
151 NF_INVF(e, EBT_ILOGICALIN,
152 ebt_dev_check(e->logical_in, p->br->dev)))
153 return 1;
154 if (out && (p = br_port_get_rcu(out)) != NULL &&
155 NF_INVF(e, EBT_ILOGICALOUT,
156 ebt_dev_check(e->logical_out, p->br->dev)))
157 return 1;
158
159 if (e->bitmask & EBT_SOURCEMAC) {
160 if (NF_INVF(e, EBT_ISOURCE,
161 !ether_addr_equal_masked(h->h_source, e->sourcemac,
162 e->sourcemsk)))
163 return 1;
164 }
165 if (e->bitmask & EBT_DESTMAC) {
166 if (NF_INVF(e, EBT_IDEST,
167 !ether_addr_equal_masked(h->h_dest, e->destmac,
168 e->destmsk)))
169 return 1;
170 }
171 return 0;
172 }
173
174 static inline
175 struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry)
176 {
177 return (void *)entry + entry->next_offset;
178 }
179
180 /* Do some firewalling */
181 unsigned int ebt_do_table(struct sk_buff *skb,
182 const struct nf_hook_state *state,
183 struct ebt_table *table)
184 {
185 unsigned int hook = state->hook;
186 int i, nentries;
187 struct ebt_entry *point;
188 struct ebt_counter *counter_base, *cb_base;
189 const struct ebt_entry_target *t;
190 int verdict, sp = 0;
191 struct ebt_chainstack *cs;
192 struct ebt_entries *chaininfo;
193 const char *base;
194 const struct ebt_table_info *private;
195 struct xt_action_param acpar;
196
197 acpar.state = state;
198 acpar.hotdrop = false;
199
200 read_lock_bh(&table->lock);
201 private = table->private;
202 cb_base = COUNTER_BASE(private->counters, private->nentries,
203 smp_processor_id());
204 if (private->chainstack)
205 cs = private->chainstack[smp_processor_id()];
206 else
207 cs = NULL;
208 chaininfo = private->hook_entry[hook];
209 nentries = private->hook_entry[hook]->nentries;
210 point = (struct ebt_entry *)(private->hook_entry[hook]->data);
211 counter_base = cb_base + private->hook_entry[hook]->counter_offset;
212 /* base for chain jumps */
213 base = private->entries;
214 i = 0;
215 while (i < nentries) {
216 if (ebt_basic_match(point, skb, state->in, state->out))
217 goto letscontinue;
218
219 if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0)
220 goto letscontinue;
221 if (acpar.hotdrop) {
222 read_unlock_bh(&table->lock);
223 return NF_DROP;
224 }
225
226 /* increase counter */
227 (*(counter_base + i)).pcnt++;
228 (*(counter_base + i)).bcnt += skb->len;
229
230 /* these should only watch: not modify, nor tell us
231 * what to do with the packet
232 */
233 EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar);
234
235 t = (struct ebt_entry_target *)
236 (((char *)point) + point->target_offset);
237 /* standard target */
238 if (!t->u.target->target)
239 verdict = ((struct ebt_standard_target *)t)->verdict;
240 else {
241 acpar.target = t->u.target;
242 acpar.targinfo = t->data;
243 verdict = t->u.target->target(skb, &acpar);
244 }
245 if (verdict == EBT_ACCEPT) {
246 read_unlock_bh(&table->lock);
247 return NF_ACCEPT;
248 }
249 if (verdict == EBT_DROP) {
250 read_unlock_bh(&table->lock);
251 return NF_DROP;
252 }
253 if (verdict == EBT_RETURN) {
254 letsreturn:
255 #ifdef CONFIG_NETFILTER_DEBUG
256 if (sp == 0) {
257 BUGPRINT("RETURN on base chain");
258 /* act like this is EBT_CONTINUE */
259 goto letscontinue;
260 }
261 #endif
262 sp--;
263 /* put all the local variables right */
264 i = cs[sp].n;
265 chaininfo = cs[sp].chaininfo;
266 nentries = chaininfo->nentries;
267 point = cs[sp].e;
268 counter_base = cb_base +
269 chaininfo->counter_offset;
270 continue;
271 }
272 if (verdict == EBT_CONTINUE)
273 goto letscontinue;
274 #ifdef CONFIG_NETFILTER_DEBUG
275 if (verdict < 0) {
276 BUGPRINT("bogus standard verdict\n");
277 read_unlock_bh(&table->lock);
278 return NF_DROP;
279 }
280 #endif
281 /* jump to a udc */
282 cs[sp].n = i + 1;
283 cs[sp].chaininfo = chaininfo;
284 cs[sp].e = ebt_next_entry(point);
285 i = 0;
286 chaininfo = (struct ebt_entries *) (base + verdict);
287 #ifdef CONFIG_NETFILTER_DEBUG
288 if (chaininfo->distinguisher) {
289 BUGPRINT("jump to non-chain\n");
290 read_unlock_bh(&table->lock);
291 return NF_DROP;
292 }
293 #endif
294 nentries = chaininfo->nentries;
295 point = (struct ebt_entry *)chaininfo->data;
296 counter_base = cb_base + chaininfo->counter_offset;
297 sp++;
298 continue;
299 letscontinue:
300 point = ebt_next_entry(point);
301 i++;
302 }
303
304 /* I actually like this :) */
305 if (chaininfo->policy == EBT_RETURN)
306 goto letsreturn;
307 if (chaininfo->policy == EBT_ACCEPT) {
308 read_unlock_bh(&table->lock);
309 return NF_ACCEPT;
310 }
311 read_unlock_bh(&table->lock);
312 return NF_DROP;
313 }
314
315 /* If it succeeds, returns element and locks mutex */
316 static inline void *
317 find_inlist_lock_noload(struct list_head *head, const char *name, int *error,
318 struct mutex *mutex)
319 {
320 struct {
321 struct list_head list;
322 char name[EBT_FUNCTION_MAXNAMELEN];
323 } *e;
324
325 mutex_lock(mutex);
326 list_for_each_entry(e, head, list) {
327 if (strcmp(e->name, name) == 0)
328 return e;
329 }
330 *error = -ENOENT;
331 mutex_unlock(mutex);
332 return NULL;
333 }
334
335 static void *
336 find_inlist_lock(struct list_head *head, const char *name, const char *prefix,
337 int *error, struct mutex *mutex)
338 {
339 return try_then_request_module(
340 find_inlist_lock_noload(head, name, error, mutex),
341 "%s%s", prefix, name);
342 }
343
344 static inline struct ebt_table *
345 find_table_lock(struct net *net, const char *name, int *error,
346 struct mutex *mutex)
347 {
348 return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name,
349 "ebtable_", error, mutex);
350 }
351
352 static inline int
353 ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
354 unsigned int *cnt)
355 {
356 const struct ebt_entry *e = par->entryinfo;
357 struct xt_match *match;
358 size_t left = ((char *)e + e->watchers_offset) - (char *)m;
359 int ret;
360
361 if (left < sizeof(struct ebt_entry_match) ||
362 left - sizeof(struct ebt_entry_match) < m->match_size)
363 return -EINVAL;
364
365 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, 0);
366 if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) {
367 if (!IS_ERR(match))
368 module_put(match->me);
369 request_module("ebt_%s", m->u.name);
370 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, 0);
371 }
372 if (IS_ERR(match))
373 return PTR_ERR(match);
374 m->u.match = match;
375
376 par->match = match;
377 par->matchinfo = m->data;
378 ret = xt_check_match(par, m->match_size,
379 e->ethproto, e->invflags & EBT_IPROTO);
380 if (ret < 0) {
381 module_put(match->me);
382 return ret;
383 }
384
385 (*cnt)++;
386 return 0;
387 }
388
389 static inline int
390 ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
391 unsigned int *cnt)
392 {
393 const struct ebt_entry *e = par->entryinfo;
394 struct xt_target *watcher;
395 size_t left = ((char *)e + e->target_offset) - (char *)w;
396 int ret;
397
398 if (left < sizeof(struct ebt_entry_watcher) ||
399 left - sizeof(struct ebt_entry_watcher) < w->watcher_size)
400 return -EINVAL;
401
402 watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0);
403 if (IS_ERR(watcher))
404 return PTR_ERR(watcher);
405 w->u.watcher = watcher;
406
407 par->target = watcher;
408 par->targinfo = w->data;
409 ret = xt_check_target(par, w->watcher_size,
410 e->ethproto, e->invflags & EBT_IPROTO);
411 if (ret < 0) {
412 module_put(watcher->me);
413 return ret;
414 }
415
416 (*cnt)++;
417 return 0;
418 }
419
420 static int ebt_verify_pointers(const struct ebt_replace *repl,
421 struct ebt_table_info *newinfo)
422 {
423 unsigned int limit = repl->entries_size;
424 unsigned int valid_hooks = repl->valid_hooks;
425 unsigned int offset = 0;
426 int i;
427
428 for (i = 0; i < NF_BR_NUMHOOKS; i++)
429 newinfo->hook_entry[i] = NULL;
430
431 newinfo->entries_size = repl->entries_size;
432 newinfo->nentries = repl->nentries;
433
434 while (offset < limit) {
435 size_t left = limit - offset;
436 struct ebt_entry *e = (void *)newinfo->entries + offset;
437
438 if (left < sizeof(unsigned int))
439 break;
440
441 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
442 if ((valid_hooks & (1 << i)) == 0)
443 continue;
444 if ((char __user *)repl->hook_entry[i] ==
445 repl->entries + offset)
446 break;
447 }
448
449 if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
450 if (e->bitmask != 0) {
451 /* we make userspace set this right,
452 * so there is no misunderstanding
453 */
454 BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set "
455 "in distinguisher\n");
456 return -EINVAL;
457 }
458 if (i != NF_BR_NUMHOOKS)
459 newinfo->hook_entry[i] = (struct ebt_entries *)e;
460 if (left < sizeof(struct ebt_entries))
461 break;
462 offset += sizeof(struct ebt_entries);
463 } else {
464 if (left < sizeof(struct ebt_entry))
465 break;
466 if (left < e->next_offset)
467 break;
468 if (e->next_offset < sizeof(struct ebt_entry))
469 return -EINVAL;
470 offset += e->next_offset;
471 }
472 }
473 if (offset != limit) {
474 BUGPRINT("entries_size too small\n");
475 return -EINVAL;
476 }
477
478 /* check if all valid hooks have a chain */
479 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
480 if (!newinfo->hook_entry[i] &&
481 (valid_hooks & (1 << i))) {
482 BUGPRINT("Valid hook without chain\n");
483 return -EINVAL;
484 }
485 }
486 return 0;
487 }
488
489 /* this one is very careful, as it is the first function
490 * to parse the userspace data
491 */
492 static inline int
493 ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
494 const struct ebt_table_info *newinfo,
495 unsigned int *n, unsigned int *cnt,
496 unsigned int *totalcnt, unsigned int *udc_cnt)
497 {
498 int i;
499
500 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
501 if ((void *)e == (void *)newinfo->hook_entry[i])
502 break;
503 }
504 /* beginning of a new chain
505 * if i == NF_BR_NUMHOOKS it must be a user defined chain
506 */
507 if (i != NF_BR_NUMHOOKS || !e->bitmask) {
508 /* this checks if the previous chain has as many entries
509 * as it said it has
510 */
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 struct ebt_chainstack cs;
554 int from;
555 unsigned int hookmask;
556 };
557
558 /* We need these positions to check that the jumps to a different part of the
559 * entries is a jump to the beginning of a new chain.
560 */
561 static inline int
562 ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo,
563 unsigned int *n, struct ebt_cl_stack *udc)
564 {
565 int i;
566
567 /* we're only interested in chain starts */
568 if (e->bitmask)
569 return 0;
570 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
571 if (newinfo->hook_entry[i] == (struct ebt_entries *)e)
572 break;
573 }
574 /* only care about udc */
575 if (i != NF_BR_NUMHOOKS)
576 return 0;
577
578 udc[*n].cs.chaininfo = (struct ebt_entries *)e;
579 /* these initialisations are depended on later in check_chainloops() */
580 udc[*n].cs.n = 0;
581 udc[*n].hookmask = 0;
582
583 (*n)++;
584 return 0;
585 }
586
587 static inline int
588 ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i)
589 {
590 struct xt_mtdtor_param par;
591
592 if (i && (*i)-- == 0)
593 return 1;
594
595 par.net = net;
596 par.match = m->u.match;
597 par.matchinfo = m->data;
598 par.family = NFPROTO_BRIDGE;
599 if (par.match->destroy != NULL)
600 par.match->destroy(&par);
601 module_put(par.match->me);
602 return 0;
603 }
604
605 static inline int
606 ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i)
607 {
608 struct xt_tgdtor_param par;
609
610 if (i && (*i)-- == 0)
611 return 1;
612
613 par.net = net;
614 par.target = w->u.watcher;
615 par.targinfo = w->data;
616 par.family = NFPROTO_BRIDGE;
617 if (par.target->destroy != NULL)
618 par.target->destroy(&par);
619 module_put(par.target->me);
620 return 0;
621 }
622
623 static inline int
624 ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
625 {
626 struct xt_tgdtor_param par;
627 struct ebt_entry_target *t;
628
629 if (e->bitmask == 0)
630 return 0;
631 /* we're done */
632 if (cnt && (*cnt)-- == 0)
633 return 1;
634 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL);
635 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL);
636 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
637
638 par.net = net;
639 par.target = t->u.target;
640 par.targinfo = t->data;
641 par.family = NFPROTO_BRIDGE;
642 if (par.target->destroy != NULL)
643 par.target->destroy(&par);
644 module_put(par.target->me);
645 return 0;
646 }
647
648 static inline int
649 ebt_check_entry(struct ebt_entry *e, struct net *net,
650 const struct ebt_table_info *newinfo,
651 const char *name, unsigned int *cnt,
652 struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
653 {
654 struct ebt_entry_target *t;
655 struct xt_target *target;
656 unsigned int i, j, hook = 0, hookmask = 0;
657 size_t gap;
658 int ret;
659 struct xt_mtchk_param mtpar;
660 struct xt_tgchk_param tgpar;
661
662 /* don't mess with the struct ebt_entries */
663 if (e->bitmask == 0)
664 return 0;
665
666 if (e->bitmask & ~EBT_F_MASK) {
667 BUGPRINT("Unknown flag for bitmask\n");
668 return -EINVAL;
669 }
670 if (e->invflags & ~EBT_INV_MASK) {
671 BUGPRINT("Unknown flag for inv bitmask\n");
672 return -EINVAL;
673 }
674 if ((e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3)) {
675 BUGPRINT("NOPROTO & 802_3 not allowed\n");
676 return -EINVAL;
677 }
678 /* what hook do we belong to? */
679 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
680 if (!newinfo->hook_entry[i])
681 continue;
682 if ((char *)newinfo->hook_entry[i] < (char *)e)
683 hook = i;
684 else
685 break;
686 }
687 /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on
688 * a base chain
689 */
690 if (i < NF_BR_NUMHOOKS)
691 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
692 else {
693 for (i = 0; i < udc_cnt; i++)
694 if ((char *)(cl_s[i].cs.chaininfo) > (char *)e)
695 break;
696 if (i == 0)
697 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
698 else
699 hookmask = cl_s[i - 1].hookmask;
700 }
701 i = 0;
702
703 mtpar.net = tgpar.net = net;
704 mtpar.table = tgpar.table = name;
705 mtpar.entryinfo = tgpar.entryinfo = e;
706 mtpar.hook_mask = tgpar.hook_mask = hookmask;
707 mtpar.family = tgpar.family = NFPROTO_BRIDGE;
708 ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i);
709 if (ret != 0)
710 goto cleanup_matches;
711 j = 0;
712 ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j);
713 if (ret != 0)
714 goto cleanup_watchers;
715 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
716 gap = e->next_offset - e->target_offset;
717
718 target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0);
719 if (IS_ERR(target)) {
720 ret = PTR_ERR(target);
721 goto cleanup_watchers;
722 }
723
724 t->u.target = target;
725 if (t->u.target == &ebt_standard_target) {
726 if (gap < sizeof(struct ebt_standard_target)) {
727 BUGPRINT("Standard target size too big\n");
728 ret = -EFAULT;
729 goto cleanup_watchers;
730 }
731 if (((struct ebt_standard_target *)t)->verdict <
732 -NUM_STANDARD_TARGETS) {
733 BUGPRINT("Invalid standard target\n");
734 ret = -EFAULT;
735 goto cleanup_watchers;
736 }
737 } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) {
738 module_put(t->u.target->me);
739 ret = -EFAULT;
740 goto cleanup_watchers;
741 }
742
743 tgpar.target = target;
744 tgpar.targinfo = t->data;
745 ret = xt_check_target(&tgpar, t->target_size,
746 e->ethproto, e->invflags & EBT_IPROTO);
747 if (ret < 0) {
748 module_put(target->me);
749 goto cleanup_watchers;
750 }
751 (*cnt)++;
752 return 0;
753 cleanup_watchers:
754 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j);
755 cleanup_matches:
756 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i);
757 return ret;
758 }
759
760 /* checks for loops and sets the hook mask for udc
761 * the hook mask for udc tells us from which base chains the udc can be
762 * accessed. This mask is a parameter to the check() functions of the extensions
763 */
764 static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
765 unsigned int udc_cnt, unsigned int hooknr, char *base)
766 {
767 int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
768 const struct ebt_entry *e = (struct ebt_entry *)chain->data;
769 const struct ebt_entry_target *t;
770
771 while (pos < nentries || chain_nr != -1) {
772 /* end of udc, go back one 'recursion' step */
773 if (pos == nentries) {
774 /* put back values of the time when this chain was called */
775 e = cl_s[chain_nr].cs.e;
776 if (cl_s[chain_nr].from != -1)
777 nentries =
778 cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries;
779 else
780 nentries = chain->nentries;
781 pos = cl_s[chain_nr].cs.n;
782 /* make sure we won't see a loop that isn't one */
783 cl_s[chain_nr].cs.n = 0;
784 chain_nr = cl_s[chain_nr].from;
785 if (pos == nentries)
786 continue;
787 }
788 t = (struct ebt_entry_target *)
789 (((char *)e) + e->target_offset);
790 if (strcmp(t->u.name, EBT_STANDARD_TARGET))
791 goto letscontinue;
792 if (e->target_offset + sizeof(struct ebt_standard_target) >
793 e->next_offset) {
794 BUGPRINT("Standard target size too big\n");
795 return -1;
796 }
797 verdict = ((struct ebt_standard_target *)t)->verdict;
798 if (verdict >= 0) { /* jump to another chain */
799 struct ebt_entries *hlp2 =
800 (struct ebt_entries *)(base + verdict);
801 for (i = 0; i < udc_cnt; i++)
802 if (hlp2 == cl_s[i].cs.chaininfo)
803 break;
804 /* bad destination or loop */
805 if (i == udc_cnt) {
806 BUGPRINT("bad destination\n");
807 return -1;
808 }
809 if (cl_s[i].cs.n) {
810 BUGPRINT("loop\n");
811 return -1;
812 }
813 if (cl_s[i].hookmask & (1 << hooknr))
814 goto letscontinue;
815 /* this can't be 0, so the loop test is correct */
816 cl_s[i].cs.n = pos + 1;
817 pos = 0;
818 cl_s[i].cs.e = ebt_next_entry(e);
819 e = (struct ebt_entry *)(hlp2->data);
820 nentries = hlp2->nentries;
821 cl_s[i].from = chain_nr;
822 chain_nr = i;
823 /* this udc is accessible from the base chain for hooknr */
824 cl_s[i].hookmask |= (1 << hooknr);
825 continue;
826 }
827 letscontinue:
828 e = ebt_next_entry(e);
829 pos++;
830 }
831 return 0;
832 }
833
834 /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
835 static int translate_table(struct net *net, const char *name,
836 struct ebt_table_info *newinfo)
837 {
838 unsigned int i, j, k, udc_cnt;
839 int ret;
840 struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */
841
842 i = 0;
843 while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i])
844 i++;
845 if (i == NF_BR_NUMHOOKS) {
846 BUGPRINT("No valid hooks specified\n");
847 return -EINVAL;
848 }
849 if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) {
850 BUGPRINT("Chains don't start at beginning\n");
851 return -EINVAL;
852 }
853 /* make sure chains are ordered after each other in same order
854 * as their corresponding hooks
855 */
856 for (j = i + 1; j < NF_BR_NUMHOOKS; j++) {
857 if (!newinfo->hook_entry[j])
858 continue;
859 if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) {
860 BUGPRINT("Hook order must be followed\n");
861 return -EINVAL;
862 }
863 i = j;
864 }
865
866 /* do some early checkings and initialize some things */
867 i = 0; /* holds the expected nr. of entries for the chain */
868 j = 0; /* holds the up to now counted entries for the chain */
869 k = 0; /* holds the total nr. of entries, should equal
870 * newinfo->nentries afterwards
871 */
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 */
893 if (udc_cnt) {
894 /* this will get free'd in do_replace()/ebt_register_table()
895 * if an error occurs
896 */
897 newinfo->chainstack =
898 vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack)));
899 if (!newinfo->chainstack)
900 return -ENOMEM;
901 for_each_possible_cpu(i) {
902 newinfo->chainstack[i] =
903 vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0])));
904 if (!newinfo->chainstack[i]) {
905 while (i)
906 vfree(newinfo->chainstack[--i]);
907 vfree(newinfo->chainstack);
908 newinfo->chainstack = NULL;
909 return -ENOMEM;
910 }
911 }
912
913 cl_s = vmalloc(udc_cnt * sizeof(*cl_s));
914 if (!cl_s)
915 return -ENOMEM;
916 i = 0; /* the i'th udc */
917 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
918 ebt_get_udc_positions, newinfo, &i, cl_s);
919 /* sanity check */
920 if (i != udc_cnt) {
921 BUGPRINT("i != udc_cnt\n");
922 vfree(cl_s);
923 return -EFAULT;
924 }
925 }
926
927 /* Check for loops */
928 for (i = 0; i < NF_BR_NUMHOOKS; i++)
929 if (newinfo->hook_entry[i])
930 if (check_chainloops(newinfo->hook_entry[i],
931 cl_s, udc_cnt, i, newinfo->entries)) {
932 vfree(cl_s);
933 return -EINVAL;
934 }
935
936 /* we now know the following (along with E=mc²):
937 * - the nr of entries in each chain is right
938 * - the size of the allocated space is right
939 * - all valid hooks have a corresponding chain
940 * - there are no loops
941 * - wrong data can still be on the level of a single entry
942 * - could be there are jumps to places that are not the
943 * beginning of a chain. This can only occur in chains that
944 * are not accessible from any base chains, so we don't care.
945 */
946
947 /* used to know what we need to clean up if something goes wrong */
948 i = 0;
949 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
950 ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt);
951 if (ret != 0) {
952 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
953 ebt_cleanup_entry, net, &i);
954 }
955 vfree(cl_s);
956 return ret;
957 }
958
959 /* called under write_lock */
960 static void get_counters(const struct ebt_counter *oldcounters,
961 struct ebt_counter *counters, unsigned int nentries)
962 {
963 int i, cpu;
964 struct ebt_counter *counter_base;
965
966 /* counters of cpu 0 */
967 memcpy(counters, oldcounters,
968 sizeof(struct ebt_counter) * nentries);
969
970 /* add other counters to those of cpu 0 */
971 for_each_possible_cpu(cpu) {
972 if (cpu == 0)
973 continue;
974 counter_base = COUNTER_BASE(oldcounters, nentries, cpu);
975 for (i = 0; i < nentries; i++) {
976 counters[i].pcnt += counter_base[i].pcnt;
977 counters[i].bcnt += counter_base[i].bcnt;
978 }
979 }
980 }
981
982 static int do_replace_finish(struct net *net, struct ebt_replace *repl,
983 struct ebt_table_info *newinfo)
984 {
985 int ret, i;
986 struct ebt_counter *counterstmp = NULL;
987 /* used to be able to unlock earlier */
988 struct ebt_table_info *table;
989 struct ebt_table *t;
990
991 /* the user wants counters back
992 * the check on the size is done later, when we have the lock
993 */
994 if (repl->num_counters) {
995 unsigned long size = repl->num_counters * sizeof(*counterstmp);
996 counterstmp = vmalloc(size);
997 if (!counterstmp)
998 return -ENOMEM;
999 }
1000
1001 newinfo->chainstack = NULL;
1002 ret = ebt_verify_pointers(repl, newinfo);
1003 if (ret != 0)
1004 goto free_counterstmp;
1005
1006 ret = translate_table(net, repl->name, newinfo);
1007
1008 if (ret != 0)
1009 goto free_counterstmp;
1010
1011 t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
1012 if (!t) {
1013 ret = -ENOENT;
1014 goto free_iterate;
1015 }
1016
1017 /* the table doesn't like it */
1018 if (t->check && (ret = t->check(newinfo, repl->valid_hooks)))
1019 goto free_unlock;
1020
1021 if (repl->num_counters && repl->num_counters != t->private->nentries) {
1022 BUGPRINT("Wrong nr. of counters requested\n");
1023 ret = -EINVAL;
1024 goto free_unlock;
1025 }
1026
1027 /* we have the mutex lock, so no danger in reading this pointer */
1028 table = t->private;
1029 /* make sure the table can only be rmmod'ed if it contains no rules */
1030 if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) {
1031 ret = -ENOENT;
1032 goto free_unlock;
1033 } else if (table->nentries && !newinfo->nentries)
1034 module_put(t->me);
1035 /* we need an atomic snapshot of the counters */
1036 write_lock_bh(&t->lock);
1037 if (repl->num_counters)
1038 get_counters(t->private->counters, counterstmp,
1039 t->private->nentries);
1040
1041 t->private = newinfo;
1042 write_unlock_bh(&t->lock);
1043 mutex_unlock(&ebt_mutex);
1044 /* so, a user can change the chains while having messed up her counter
1045 * allocation. Only reason why this is done is because this way the lock
1046 * is held only once, while this doesn't bring the kernel into a
1047 * dangerous state.
1048 */
1049 if (repl->num_counters &&
1050 copy_to_user(repl->counters, counterstmp,
1051 repl->num_counters * sizeof(struct ebt_counter))) {
1052 /* Silent error, can't fail, new table is already in place */
1053 net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n");
1054 }
1055
1056 /* decrease module count and free resources */
1057 EBT_ENTRY_ITERATE(table->entries, table->entries_size,
1058 ebt_cleanup_entry, net, NULL);
1059
1060 vfree(table->entries);
1061 if (table->chainstack) {
1062 for_each_possible_cpu(i)
1063 vfree(table->chainstack[i]);
1064 vfree(table->chainstack);
1065 }
1066 vfree(table);
1067
1068 vfree(counterstmp);
1069
1070 #ifdef CONFIG_AUDIT
1071 if (audit_enabled) {
1072 struct audit_buffer *ab;
1073
1074 ab = audit_log_start(current->audit_context, GFP_KERNEL,
1075 AUDIT_NETFILTER_CFG);
1076 if (ab) {
1077 audit_log_format(ab, "table=%s family=%u entries=%u",
1078 repl->name, AF_BRIDGE, repl->nentries);
1079 audit_log_end(ab);
1080 }
1081 }
1082 #endif
1083 return ret;
1084
1085 free_unlock:
1086 mutex_unlock(&ebt_mutex);
1087 free_iterate:
1088 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
1089 ebt_cleanup_entry, net, NULL);
1090 free_counterstmp:
1091 vfree(counterstmp);
1092 /* can be initialized in translate_table() */
1093 if (newinfo->chainstack) {
1094 for_each_possible_cpu(i)
1095 vfree(newinfo->chainstack[i]);
1096 vfree(newinfo->chainstack);
1097 }
1098 return ret;
1099 }
1100
1101 /* replace the table */
1102 static int do_replace(struct net *net, const void __user *user,
1103 unsigned int len)
1104 {
1105 int ret, countersize;
1106 struct ebt_table_info *newinfo;
1107 struct ebt_replace tmp;
1108
1109 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1110 return -EFAULT;
1111
1112 if (len != sizeof(tmp) + tmp.entries_size) {
1113 BUGPRINT("Wrong len argument\n");
1114 return -EINVAL;
1115 }
1116
1117 if (tmp.entries_size == 0) {
1118 BUGPRINT("Entries_size never zero\n");
1119 return -EINVAL;
1120 }
1121 /* overflow check */
1122 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
1123 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
1124 return -ENOMEM;
1125 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
1126 return -ENOMEM;
1127
1128 tmp.name[sizeof(tmp.name) - 1] = 0;
1129
1130 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
1131 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1132 if (!newinfo)
1133 return -ENOMEM;
1134
1135 if (countersize)
1136 memset(newinfo->counters, 0, countersize);
1137
1138 newinfo->entries = vmalloc(tmp.entries_size);
1139 if (!newinfo->entries) {
1140 ret = -ENOMEM;
1141 goto free_newinfo;
1142 }
1143 if (copy_from_user(
1144 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
1145 BUGPRINT("Couldn't copy entries from userspace\n");
1146 ret = -EFAULT;
1147 goto free_entries;
1148 }
1149
1150 ret = do_replace_finish(net, &tmp, newinfo);
1151 if (ret == 0)
1152 return ret;
1153 free_entries:
1154 vfree(newinfo->entries);
1155 free_newinfo:
1156 vfree(newinfo);
1157 return ret;
1158 }
1159
1160 struct ebt_table *
1161 ebt_register_table(struct net *net, const struct ebt_table *input_table)
1162 {
1163 struct ebt_table_info *newinfo;
1164 struct ebt_table *t, *table;
1165 struct ebt_replace_kernel *repl;
1166 int ret, i, countersize;
1167 void *p;
1168
1169 if (input_table == NULL || (repl = input_table->table) == NULL ||
1170 repl->entries == NULL || repl->entries_size == 0 ||
1171 repl->counters != NULL || input_table->private != NULL) {
1172 BUGPRINT("Bad table data for ebt_register_table!!!\n");
1173 return ERR_PTR(-EINVAL);
1174 }
1175
1176 /* Don't add one table to multiple lists. */
1177 table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL);
1178 if (!table) {
1179 ret = -ENOMEM;
1180 goto out;
1181 }
1182
1183 countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
1184 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1185 ret = -ENOMEM;
1186 if (!newinfo)
1187 goto free_table;
1188
1189 p = vmalloc(repl->entries_size);
1190 if (!p)
1191 goto free_newinfo;
1192
1193 memcpy(p, repl->entries, repl->entries_size);
1194 newinfo->entries = p;
1195
1196 newinfo->entries_size = repl->entries_size;
1197 newinfo->nentries = repl->nentries;
1198
1199 if (countersize)
1200 memset(newinfo->counters, 0, countersize);
1201
1202 /* fill in newinfo and parse the entries */
1203 newinfo->chainstack = NULL;
1204 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1205 if ((repl->valid_hooks & (1 << i)) == 0)
1206 newinfo->hook_entry[i] = NULL;
1207 else
1208 newinfo->hook_entry[i] = p +
1209 ((char *)repl->hook_entry[i] - repl->entries);
1210 }
1211 ret = translate_table(net, repl->name, newinfo);
1212 if (ret != 0) {
1213 BUGPRINT("Translate_table failed\n");
1214 goto free_chainstack;
1215 }
1216
1217 if (table->check && table->check(newinfo, table->valid_hooks)) {
1218 BUGPRINT("The table doesn't like its own initial data, lol\n");
1219 ret = -EINVAL;
1220 goto free_chainstack;
1221 }
1222
1223 table->private = newinfo;
1224 rwlock_init(&table->lock);
1225 mutex_lock(&ebt_mutex);
1226 list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
1227 if (strcmp(t->name, table->name) == 0) {
1228 ret = -EEXIST;
1229 BUGPRINT("Table name already exists\n");
1230 goto free_unlock;
1231 }
1232 }
1233
1234 /* Hold a reference count if the chains aren't empty */
1235 if (newinfo->nentries && !try_module_get(table->me)) {
1236 ret = -ENOENT;
1237 goto free_unlock;
1238 }
1239 list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
1240 mutex_unlock(&ebt_mutex);
1241 return table;
1242 free_unlock:
1243 mutex_unlock(&ebt_mutex);
1244 free_chainstack:
1245 if (newinfo->chainstack) {
1246 for_each_possible_cpu(i)
1247 vfree(newinfo->chainstack[i]);
1248 vfree(newinfo->chainstack);
1249 }
1250 vfree(newinfo->entries);
1251 free_newinfo:
1252 vfree(newinfo);
1253 free_table:
1254 kfree(table);
1255 out:
1256 return ERR_PTR(ret);
1257 }
1258
1259 void ebt_unregister_table(struct net *net, struct ebt_table *table)
1260 {
1261 int i;
1262
1263 if (!table) {
1264 BUGPRINT("Request to unregister NULL table!!!\n");
1265 return;
1266 }
1267 mutex_lock(&ebt_mutex);
1268 list_del(&table->list);
1269 mutex_unlock(&ebt_mutex);
1270 EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
1271 ebt_cleanup_entry, net, NULL);
1272 if (table->private->nentries)
1273 module_put(table->me);
1274 vfree(table->private->entries);
1275 if (table->private->chainstack) {
1276 for_each_possible_cpu(i)
1277 vfree(table->private->chainstack[i]);
1278 vfree(table->private->chainstack);
1279 }
1280 vfree(table->private);
1281 kfree(table);
1282 }
1283
1284 /* userspace just supplied us with counters */
1285 static int do_update_counters(struct net *net, const char *name,
1286 struct ebt_counter __user *counters,
1287 unsigned int num_counters,
1288 const void __user *user, unsigned int len)
1289 {
1290 int i, ret;
1291 struct ebt_counter *tmp;
1292 struct ebt_table *t;
1293
1294 if (num_counters == 0)
1295 return -EINVAL;
1296
1297 tmp = vmalloc(num_counters * sizeof(*tmp));
1298 if (!tmp)
1299 return -ENOMEM;
1300
1301 t = find_table_lock(net, name, &ret, &ebt_mutex);
1302 if (!t)
1303 goto free_tmp;
1304
1305 if (num_counters != t->private->nentries) {
1306 BUGPRINT("Wrong nr of counters\n");
1307 ret = -EINVAL;
1308 goto unlock_mutex;
1309 }
1310
1311 if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) {
1312 ret = -EFAULT;
1313 goto unlock_mutex;
1314 }
1315
1316 /* we want an atomic add of the counters */
1317 write_lock_bh(&t->lock);
1318
1319 /* we add to the counters of the first cpu */
1320 for (i = 0; i < num_counters; i++) {
1321 t->private->counters[i].pcnt += tmp[i].pcnt;
1322 t->private->counters[i].bcnt += tmp[i].bcnt;
1323 }
1324
1325 write_unlock_bh(&t->lock);
1326 ret = 0;
1327 unlock_mutex:
1328 mutex_unlock(&ebt_mutex);
1329 free_tmp:
1330 vfree(tmp);
1331 return ret;
1332 }
1333
1334 static int update_counters(struct net *net, const void __user *user,
1335 unsigned int len)
1336 {
1337 struct ebt_replace hlp;
1338
1339 if (copy_from_user(&hlp, user, sizeof(hlp)))
1340 return -EFAULT;
1341
1342 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
1343 return -EINVAL;
1344
1345 return do_update_counters(net, hlp.name, hlp.counters,
1346 hlp.num_counters, user, len);
1347 }
1348
1349 static inline int ebt_make_matchname(const struct ebt_entry_match *m,
1350 const char *base, char __user *ubase)
1351 {
1352 char __user *hlp = ubase + ((char *)m - base);
1353 char name[EBT_FUNCTION_MAXNAMELEN] = {};
1354
1355 /* ebtables expects 32 bytes long names but xt_match names are 29 bytes
1356 * long. Copy 29 bytes and fill remaining bytes with zeroes.
1357 */
1358 strlcpy(name, m->u.match->name, sizeof(name));
1359 if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN))
1360 return -EFAULT;
1361 return 0;
1362 }
1363
1364 static inline int ebt_make_watchername(const struct ebt_entry_watcher *w,
1365 const char *base, char __user *ubase)
1366 {
1367 char __user *hlp = ubase + ((char *)w - base);
1368 char name[EBT_FUNCTION_MAXNAMELEN] = {};
1369
1370 strlcpy(name, w->u.watcher->name, sizeof(name));
1371 if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN))
1372 return -EFAULT;
1373 return 0;
1374 }
1375
1376 static inline int ebt_make_names(struct ebt_entry *e, const char *base,
1377 char __user *ubase)
1378 {
1379 int ret;
1380 char __user *hlp;
1381 const struct ebt_entry_target *t;
1382 char name[EBT_FUNCTION_MAXNAMELEN] = {};
1383
1384 if (e->bitmask == 0)
1385 return 0;
1386
1387 hlp = ubase + (((char *)e + e->target_offset) - base);
1388 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
1389
1390 ret = EBT_MATCH_ITERATE(e, ebt_make_matchname, base, ubase);
1391 if (ret != 0)
1392 return ret;
1393 ret = EBT_WATCHER_ITERATE(e, ebt_make_watchername, base, ubase);
1394 if (ret != 0)
1395 return ret;
1396 strlcpy(name, t->u.target->name, sizeof(name));
1397 if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN))
1398 return -EFAULT;
1399 return 0;
1400 }
1401
1402 static int copy_counters_to_user(struct ebt_table *t,
1403 const struct ebt_counter *oldcounters,
1404 void __user *user, unsigned int num_counters,
1405 unsigned int nentries)
1406 {
1407 struct ebt_counter *counterstmp;
1408 int ret = 0;
1409
1410 /* userspace might not need the counters */
1411 if (num_counters == 0)
1412 return 0;
1413
1414 if (num_counters != nentries) {
1415 BUGPRINT("Num_counters wrong\n");
1416 return -EINVAL;
1417 }
1418
1419 counterstmp = vmalloc(nentries * sizeof(*counterstmp));
1420 if (!counterstmp)
1421 return -ENOMEM;
1422
1423 write_lock_bh(&t->lock);
1424 get_counters(oldcounters, counterstmp, nentries);
1425 write_unlock_bh(&t->lock);
1426
1427 if (copy_to_user(user, counterstmp,
1428 nentries * sizeof(struct ebt_counter)))
1429 ret = -EFAULT;
1430 vfree(counterstmp);
1431 return ret;
1432 }
1433
1434 /* called with ebt_mutex locked */
1435 static int copy_everything_to_user(struct ebt_table *t, void __user *user,
1436 const int *len, int cmd)
1437 {
1438 struct ebt_replace tmp;
1439 const struct ebt_counter *oldcounters;
1440 unsigned int entries_size, nentries;
1441 int ret;
1442 char *entries;
1443
1444 if (cmd == EBT_SO_GET_ENTRIES) {
1445 entries_size = t->private->entries_size;
1446 nentries = t->private->nentries;
1447 entries = t->private->entries;
1448 oldcounters = t->private->counters;
1449 } else {
1450 entries_size = t->table->entries_size;
1451 nentries = t->table->nentries;
1452 entries = t->table->entries;
1453 oldcounters = t->table->counters;
1454 }
1455
1456 if (copy_from_user(&tmp, user, sizeof(tmp)))
1457 return -EFAULT;
1458
1459 if (*len != sizeof(struct ebt_replace) + entries_size +
1460 (tmp.num_counters ? nentries * sizeof(struct ebt_counter) : 0))
1461 return -EINVAL;
1462
1463 if (tmp.nentries != nentries) {
1464 BUGPRINT("Nentries wrong\n");
1465 return -EINVAL;
1466 }
1467
1468 if (tmp.entries_size != entries_size) {
1469 BUGPRINT("Wrong size\n");
1470 return -EINVAL;
1471 }
1472
1473 ret = copy_counters_to_user(t, oldcounters, tmp.counters,
1474 tmp.num_counters, nentries);
1475 if (ret)
1476 return ret;
1477
1478 if (copy_to_user(tmp.entries, entries, entries_size)) {
1479 BUGPRINT("Couldn't copy entries to userspace\n");
1480 return -EFAULT;
1481 }
1482 /* set the match/watcher/target names right */
1483 return EBT_ENTRY_ITERATE(entries, entries_size,
1484 ebt_make_names, entries, tmp.entries);
1485 }
1486
1487 static int do_ebt_set_ctl(struct sock *sk,
1488 int cmd, void __user *user, unsigned int len)
1489 {
1490 int ret;
1491 struct net *net = sock_net(sk);
1492
1493 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1494 return -EPERM;
1495
1496 switch (cmd) {
1497 case EBT_SO_SET_ENTRIES:
1498 ret = do_replace(net, user, len);
1499 break;
1500 case EBT_SO_SET_COUNTERS:
1501 ret = update_counters(net, user, len);
1502 break;
1503 default:
1504 ret = -EINVAL;
1505 }
1506 return ret;
1507 }
1508
1509 static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1510 {
1511 int ret;
1512 struct ebt_replace tmp;
1513 struct ebt_table *t;
1514 struct net *net = sock_net(sk);
1515
1516 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1517 return -EPERM;
1518
1519 if (copy_from_user(&tmp, user, sizeof(tmp)))
1520 return -EFAULT;
1521
1522 tmp.name[sizeof(tmp.name) - 1] = '\0';
1523
1524 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
1525 if (!t)
1526 return ret;
1527
1528 switch (cmd) {
1529 case EBT_SO_GET_INFO:
1530 case EBT_SO_GET_INIT_INFO:
1531 if (*len != sizeof(struct ebt_replace)) {
1532 ret = -EINVAL;
1533 mutex_unlock(&ebt_mutex);
1534 break;
1535 }
1536 if (cmd == EBT_SO_GET_INFO) {
1537 tmp.nentries = t->private->nentries;
1538 tmp.entries_size = t->private->entries_size;
1539 tmp.valid_hooks = t->valid_hooks;
1540 } else {
1541 tmp.nentries = t->table->nentries;
1542 tmp.entries_size = t->table->entries_size;
1543 tmp.valid_hooks = t->table->valid_hooks;
1544 }
1545 mutex_unlock(&ebt_mutex);
1546 if (copy_to_user(user, &tmp, *len) != 0) {
1547 BUGPRINT("c2u Didn't work\n");
1548 ret = -EFAULT;
1549 break;
1550 }
1551 ret = 0;
1552 break;
1553
1554 case EBT_SO_GET_ENTRIES:
1555 case EBT_SO_GET_INIT_ENTRIES:
1556 ret = copy_everything_to_user(t, user, len, cmd);
1557 mutex_unlock(&ebt_mutex);
1558 break;
1559
1560 default:
1561 mutex_unlock(&ebt_mutex);
1562 ret = -EINVAL;
1563 }
1564
1565 return ret;
1566 }
1567
1568 #ifdef CONFIG_COMPAT
1569 /* 32 bit-userspace compatibility definitions. */
1570 struct compat_ebt_replace {
1571 char name[EBT_TABLE_MAXNAMELEN];
1572 compat_uint_t valid_hooks;
1573 compat_uint_t nentries;
1574 compat_uint_t entries_size;
1575 /* start of the chains */
1576 compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
1577 /* nr of counters userspace expects back */
1578 compat_uint_t num_counters;
1579 /* where the kernel will put the old counters. */
1580 compat_uptr_t counters;
1581 compat_uptr_t entries;
1582 };
1583
1584 /* struct ebt_entry_match, _target and _watcher have same layout */
1585 struct compat_ebt_entry_mwt {
1586 union {
1587 char name[EBT_FUNCTION_MAXNAMELEN];
1588 compat_uptr_t ptr;
1589 } u;
1590 compat_uint_t match_size;
1591 compat_uint_t data[0];
1592 };
1593
1594 /* account for possible padding between match_size and ->data */
1595 static int ebt_compat_entry_padsize(void)
1596 {
1597 BUILD_BUG_ON(XT_ALIGN(sizeof(struct ebt_entry_match)) <
1598 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt)));
1599 return (int) XT_ALIGN(sizeof(struct ebt_entry_match)) -
1600 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt));
1601 }
1602
1603 static int ebt_compat_match_offset(const struct xt_match *match,
1604 unsigned int userlen)
1605 {
1606 /* ebt_among needs special handling. The kernel .matchsize is
1607 * set to -1 at registration time; at runtime an EBT_ALIGN()ed
1608 * value is expected.
1609 * Example: userspace sends 4500, ebt_among.c wants 4504.
1610 */
1611 if (unlikely(match->matchsize == -1))
1612 return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
1613 return xt_compat_match_offset(match);
1614 }
1615
1616 static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
1617 unsigned int *size)
1618 {
1619 const struct xt_match *match = m->u.match;
1620 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1621 int off = ebt_compat_match_offset(match, m->match_size);
1622 compat_uint_t msize = m->match_size - off;
1623
1624 BUG_ON(off >= m->match_size);
1625
1626 if (copy_to_user(cm->u.name, match->name,
1627 strlen(match->name) + 1) || put_user(msize, &cm->match_size))
1628 return -EFAULT;
1629
1630 if (match->compat_to_user) {
1631 if (match->compat_to_user(cm->data, m->data))
1632 return -EFAULT;
1633 } else if (copy_to_user(cm->data, m->data, msize))
1634 return -EFAULT;
1635
1636 *size -= ebt_compat_entry_padsize() + off;
1637 *dstptr = cm->data;
1638 *dstptr += msize;
1639 return 0;
1640 }
1641
1642 static int compat_target_to_user(struct ebt_entry_target *t,
1643 void __user **dstptr,
1644 unsigned int *size)
1645 {
1646 const struct xt_target *target = t->u.target;
1647 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1648 int off = xt_compat_target_offset(target);
1649 compat_uint_t tsize = t->target_size - off;
1650
1651 BUG_ON(off >= t->target_size);
1652
1653 if (copy_to_user(cm->u.name, target->name,
1654 strlen(target->name) + 1) || put_user(tsize, &cm->match_size))
1655 return -EFAULT;
1656
1657 if (target->compat_to_user) {
1658 if (target->compat_to_user(cm->data, t->data))
1659 return -EFAULT;
1660 } else if (copy_to_user(cm->data, t->data, tsize))
1661 return -EFAULT;
1662
1663 *size -= ebt_compat_entry_padsize() + off;
1664 *dstptr = cm->data;
1665 *dstptr += tsize;
1666 return 0;
1667 }
1668
1669 static int compat_watcher_to_user(struct ebt_entry_watcher *w,
1670 void __user **dstptr,
1671 unsigned int *size)
1672 {
1673 return compat_target_to_user((struct ebt_entry_target *)w,
1674 dstptr, size);
1675 }
1676
1677 static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
1678 unsigned int *size)
1679 {
1680 struct ebt_entry_target *t;
1681 struct ebt_entry __user *ce;
1682 u32 watchers_offset, target_offset, next_offset;
1683 compat_uint_t origsize;
1684 int ret;
1685
1686 if (e->bitmask == 0) {
1687 if (*size < sizeof(struct ebt_entries))
1688 return -EINVAL;
1689 if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries)))
1690 return -EFAULT;
1691
1692 *dstptr += sizeof(struct ebt_entries);
1693 *size -= sizeof(struct ebt_entries);
1694 return 0;
1695 }
1696
1697 if (*size < sizeof(*ce))
1698 return -EINVAL;
1699
1700 ce = (struct ebt_entry __user *)*dstptr;
1701 if (copy_to_user(ce, e, sizeof(*ce)))
1702 return -EFAULT;
1703
1704 origsize = *size;
1705 *dstptr += sizeof(*ce);
1706
1707 ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
1708 if (ret)
1709 return ret;
1710 watchers_offset = e->watchers_offset - (origsize - *size);
1711
1712 ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
1713 if (ret)
1714 return ret;
1715 target_offset = e->target_offset - (origsize - *size);
1716
1717 t = (struct ebt_entry_target *) ((char *) e + e->target_offset);
1718
1719 ret = compat_target_to_user(t, dstptr, size);
1720 if (ret)
1721 return ret;
1722 next_offset = e->next_offset - (origsize - *size);
1723
1724 if (put_user(watchers_offset, &ce->watchers_offset) ||
1725 put_user(target_offset, &ce->target_offset) ||
1726 put_user(next_offset, &ce->next_offset))
1727 return -EFAULT;
1728
1729 *size -= sizeof(*ce);
1730 return 0;
1731 }
1732
1733 static int compat_calc_match(struct ebt_entry_match *m, int *off)
1734 {
1735 *off += ebt_compat_match_offset(m->u.match, m->match_size);
1736 *off += ebt_compat_entry_padsize();
1737 return 0;
1738 }
1739
1740 static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
1741 {
1742 *off += xt_compat_target_offset(w->u.watcher);
1743 *off += ebt_compat_entry_padsize();
1744 return 0;
1745 }
1746
1747 static int compat_calc_entry(const struct ebt_entry *e,
1748 const struct ebt_table_info *info,
1749 const void *base,
1750 struct compat_ebt_replace *newinfo)
1751 {
1752 const struct ebt_entry_target *t;
1753 unsigned int entry_offset;
1754 int off, ret, i;
1755
1756 if (e->bitmask == 0)
1757 return 0;
1758
1759 off = 0;
1760 entry_offset = (void *)e - base;
1761
1762 EBT_MATCH_ITERATE(e, compat_calc_match, &off);
1763 EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
1764
1765 t = (const struct ebt_entry_target *) ((char *) e + e->target_offset);
1766
1767 off += xt_compat_target_offset(t->u.target);
1768 off += ebt_compat_entry_padsize();
1769
1770 newinfo->entries_size -= off;
1771
1772 ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off);
1773 if (ret)
1774 return ret;
1775
1776 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1777 const void *hookptr = info->hook_entry[i];
1778 if (info->hook_entry[i] &&
1779 (e < (struct ebt_entry *)(base - hookptr))) {
1780 newinfo->hook_entry[i] -= off;
1781 pr_debug("0x%08X -> 0x%08X\n",
1782 newinfo->hook_entry[i] + off,
1783 newinfo->hook_entry[i]);
1784 }
1785 }
1786
1787 return 0;
1788 }
1789
1790
1791 static int compat_table_info(const struct ebt_table_info *info,
1792 struct compat_ebt_replace *newinfo)
1793 {
1794 unsigned int size = info->entries_size;
1795 const void *entries = info->entries;
1796
1797 newinfo->entries_size = size;
1798
1799 xt_compat_init_offsets(NFPROTO_BRIDGE, info->nentries);
1800 return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
1801 entries, newinfo);
1802 }
1803
1804 static int compat_copy_everything_to_user(struct ebt_table *t,
1805 void __user *user, int *len, int cmd)
1806 {
1807 struct compat_ebt_replace repl, tmp;
1808 struct ebt_counter *oldcounters;
1809 struct ebt_table_info tinfo;
1810 int ret;
1811 void __user *pos;
1812
1813 memset(&tinfo, 0, sizeof(tinfo));
1814
1815 if (cmd == EBT_SO_GET_ENTRIES) {
1816 tinfo.entries_size = t->private->entries_size;
1817 tinfo.nentries = t->private->nentries;
1818 tinfo.entries = t->private->entries;
1819 oldcounters = t->private->counters;
1820 } else {
1821 tinfo.entries_size = t->table->entries_size;
1822 tinfo.nentries = t->table->nentries;
1823 tinfo.entries = t->table->entries;
1824 oldcounters = t->table->counters;
1825 }
1826
1827 if (copy_from_user(&tmp, user, sizeof(tmp)))
1828 return -EFAULT;
1829
1830 if (tmp.nentries != tinfo.nentries ||
1831 (tmp.num_counters && tmp.num_counters != tinfo.nentries))
1832 return -EINVAL;
1833
1834 memcpy(&repl, &tmp, sizeof(repl));
1835 if (cmd == EBT_SO_GET_ENTRIES)
1836 ret = compat_table_info(t->private, &repl);
1837 else
1838 ret = compat_table_info(&tinfo, &repl);
1839 if (ret)
1840 return ret;
1841
1842 if (*len != sizeof(tmp) + repl.entries_size +
1843 (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
1844 pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
1845 *len, tinfo.entries_size, repl.entries_size);
1846 return -EINVAL;
1847 }
1848
1849 /* userspace might not need the counters */
1850 ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters),
1851 tmp.num_counters, tinfo.nentries);
1852 if (ret)
1853 return ret;
1854
1855 pos = compat_ptr(tmp.entries);
1856 return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
1857 compat_copy_entry_to_user, &pos, &tmp.entries_size);
1858 }
1859
1860 struct ebt_entries_buf_state {
1861 char *buf_kern_start; /* kernel buffer to copy (translated) data to */
1862 u32 buf_kern_len; /* total size of kernel buffer */
1863 u32 buf_kern_offset; /* amount of data copied so far */
1864 u32 buf_user_offset; /* read position in userspace buffer */
1865 };
1866
1867 static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
1868 {
1869 state->buf_kern_offset += sz;
1870 return state->buf_kern_offset >= sz ? 0 : -EINVAL;
1871 }
1872
1873 static int ebt_buf_add(struct ebt_entries_buf_state *state,
1874 void *data, unsigned int sz)
1875 {
1876 if (state->buf_kern_start == NULL)
1877 goto count_only;
1878
1879 BUG_ON(state->buf_kern_offset + sz > state->buf_kern_len);
1880
1881 memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz);
1882
1883 count_only:
1884 state->buf_user_offset += sz;
1885 return ebt_buf_count(state, sz);
1886 }
1887
1888 static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz)
1889 {
1890 char *b = state->buf_kern_start;
1891
1892 BUG_ON(b && state->buf_kern_offset > state->buf_kern_len);
1893
1894 if (b != NULL && sz > 0)
1895 memset(b + state->buf_kern_offset, 0, sz);
1896 /* do not adjust ->buf_user_offset here, we added kernel-side padding */
1897 return ebt_buf_count(state, sz);
1898 }
1899
1900 enum compat_mwt {
1901 EBT_COMPAT_MATCH,
1902 EBT_COMPAT_WATCHER,
1903 EBT_COMPAT_TARGET,
1904 };
1905
1906 static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt,
1907 enum compat_mwt compat_mwt,
1908 struct ebt_entries_buf_state *state,
1909 const unsigned char *base)
1910 {
1911 char name[EBT_FUNCTION_MAXNAMELEN];
1912 struct xt_match *match;
1913 struct xt_target *wt;
1914 void *dst = NULL;
1915 int off, pad = 0;
1916 unsigned int size_kern, match_size = mwt->match_size;
1917
1918 strlcpy(name, mwt->u.name, sizeof(name));
1919
1920 if (state->buf_kern_start)
1921 dst = state->buf_kern_start + state->buf_kern_offset;
1922
1923 switch (compat_mwt) {
1924 case EBT_COMPAT_MATCH:
1925 match = xt_request_find_match(NFPROTO_BRIDGE, name, 0);
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, 0);
1945 if (IS_ERR(wt))
1946 return PTR_ERR(wt);
1947 off = xt_compat_target_offset(wt);
1948
1949 if (dst) {
1950 if (wt->compat_from_user)
1951 wt->compat_from_user(dst, mwt->data);
1952 else
1953 memcpy(dst, mwt->data, match_size);
1954 }
1955
1956 size_kern = wt->targetsize;
1957 module_put(wt->me);
1958 break;
1959
1960 default:
1961 return -EINVAL;
1962 }
1963
1964 state->buf_kern_offset += match_size + off;
1965 state->buf_user_offset += match_size;
1966 pad = XT_ALIGN(size_kern) - size_kern;
1967
1968 if (pad > 0 && dst) {
1969 BUG_ON(state->buf_kern_len <= pad);
1970 BUG_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad);
1971 memset(dst + size_kern, 0, pad);
1972 }
1973 return off + match_size;
1974 }
1975
1976 /* return size of all matches, watchers or target, including necessary
1977 * alignment and padding.
1978 */
1979 static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32,
1980 unsigned int size_left, enum compat_mwt type,
1981 struct ebt_entries_buf_state *state, const void *base)
1982 {
1983 int growth = 0;
1984 char *buf;
1985
1986 if (size_left == 0)
1987 return 0;
1988
1989 buf = (char *) match32;
1990
1991 while (size_left >= sizeof(*match32)) {
1992 struct ebt_entry_match *match_kern;
1993 int ret;
1994
1995 match_kern = (struct ebt_entry_match *) state->buf_kern_start;
1996 if (match_kern) {
1997 char *tmp;
1998 tmp = state->buf_kern_start + state->buf_kern_offset;
1999 match_kern = (struct ebt_entry_match *) tmp;
2000 }
2001 ret = ebt_buf_add(state, buf, sizeof(*match32));
2002 if (ret < 0)
2003 return ret;
2004 size_left -= sizeof(*match32);
2005
2006 /* add padding before match->data (if any) */
2007 ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize());
2008 if (ret < 0)
2009 return ret;
2010
2011 if (match32->match_size > size_left)
2012 return -EINVAL;
2013
2014 size_left -= match32->match_size;
2015
2016 ret = compat_mtw_from_user(match32, type, state, base);
2017 if (ret < 0)
2018 return ret;
2019
2020 BUG_ON(ret < match32->match_size);
2021 growth += ret - match32->match_size;
2022 growth += ebt_compat_entry_padsize();
2023
2024 buf += sizeof(*match32);
2025 buf += match32->match_size;
2026
2027 if (match_kern)
2028 match_kern->match_size = ret;
2029
2030 WARN_ON(type == EBT_COMPAT_TARGET && size_left);
2031 match32 = (struct compat_ebt_entry_mwt *) buf;
2032 }
2033
2034 return growth;
2035 }
2036
2037 /* called for all ebt_entry structures. */
2038 static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,
2039 unsigned int *total,
2040 struct ebt_entries_buf_state *state)
2041 {
2042 unsigned int i, j, startoff, new_offset = 0;
2043 /* stores match/watchers/targets & offset of next struct ebt_entry: */
2044 unsigned int offsets[4];
2045 unsigned int *offsets_update = NULL;
2046 int ret;
2047 char *buf_start;
2048
2049 if (*total < sizeof(struct ebt_entries))
2050 return -EINVAL;
2051
2052 if (!entry->bitmask) {
2053 *total -= sizeof(struct ebt_entries);
2054 return ebt_buf_add(state, entry, sizeof(struct ebt_entries));
2055 }
2056 if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
2057 return -EINVAL;
2058
2059 startoff = state->buf_user_offset;
2060 /* pull in most part of ebt_entry, it does not need to be changed. */
2061 ret = ebt_buf_add(state, entry,
2062 offsetof(struct ebt_entry, watchers_offset));
2063 if (ret < 0)
2064 return ret;
2065
2066 offsets[0] = sizeof(struct ebt_entry); /* matches come first */
2067 memcpy(&offsets[1], &entry->watchers_offset,
2068 sizeof(offsets) - sizeof(offsets[0]));
2069
2070 if (state->buf_kern_start) {
2071 buf_start = state->buf_kern_start + state->buf_kern_offset;
2072 offsets_update = (unsigned int *) buf_start;
2073 }
2074 ret = ebt_buf_add(state, &offsets[1],
2075 sizeof(offsets) - sizeof(offsets[0]));
2076 if (ret < 0)
2077 return ret;
2078 buf_start = (char *) entry;
2079 /* 0: matches offset, always follows ebt_entry.
2080 * 1: watchers offset, from ebt_entry structure
2081 * 2: target offset, from ebt_entry structure
2082 * 3: next ebt_entry offset, from ebt_entry structure
2083 *
2084 * offsets are relative to beginning of struct ebt_entry (i.e., 0).
2085 */
2086 for (i = 0, j = 1 ; j < 4 ; j++, i++) {
2087 struct compat_ebt_entry_mwt *match32;
2088 unsigned int size;
2089 char *buf = buf_start;
2090
2091 buf = buf_start + offsets[i];
2092 if (offsets[i] > offsets[j])
2093 return -EINVAL;
2094
2095 match32 = (struct compat_ebt_entry_mwt *) buf;
2096 size = offsets[j] - offsets[i];
2097 ret = ebt_size_mwt(match32, size, i, state, base);
2098 if (ret < 0)
2099 return ret;
2100 new_offset += ret;
2101 if (offsets_update && new_offset) {
2102 pr_debug("change offset %d to %d\n",
2103 offsets_update[i], offsets[j] + new_offset);
2104 offsets_update[i] = offsets[j] + new_offset;
2105 }
2106 }
2107
2108 if (state->buf_kern_start == NULL) {
2109 unsigned int offset = buf_start - (char *) base;
2110
2111 ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);
2112 if (ret < 0)
2113 return ret;
2114 }
2115
2116 startoff = state->buf_user_offset - startoff;
2117
2118 BUG_ON(*total < startoff);
2119 *total -= startoff;
2120 return 0;
2121 }
2122
2123 /* repl->entries_size is the size of the ebt_entry blob in userspace.
2124 * It might need more memory when copied to a 64 bit kernel in case
2125 * userspace is 32-bit. So, first task: find out how much memory is needed.
2126 *
2127 * Called before validation is performed.
2128 */
2129 static int compat_copy_entries(unsigned char *data, unsigned int size_user,
2130 struct ebt_entries_buf_state *state)
2131 {
2132 unsigned int size_remaining = size_user;
2133 int ret;
2134
2135 ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
2136 &size_remaining, state);
2137 if (ret < 0)
2138 return ret;
2139
2140 WARN_ON(size_remaining);
2141 return state->buf_kern_offset;
2142 }
2143
2144
2145 static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
2146 void __user *user, unsigned int len)
2147 {
2148 struct compat_ebt_replace tmp;
2149 int i;
2150
2151 if (len < sizeof(tmp))
2152 return -EINVAL;
2153
2154 if (copy_from_user(&tmp, user, sizeof(tmp)))
2155 return -EFAULT;
2156
2157 if (len != sizeof(tmp) + tmp.entries_size)
2158 return -EINVAL;
2159
2160 if (tmp.entries_size == 0)
2161 return -EINVAL;
2162
2163 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
2164 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
2165 return -ENOMEM;
2166 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
2167 return -ENOMEM;
2168
2169 memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
2170
2171 /* starting with hook_entry, 32 vs. 64 bit structures are different */
2172 for (i = 0; i < NF_BR_NUMHOOKS; i++)
2173 repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]);
2174
2175 repl->num_counters = tmp.num_counters;
2176 repl->counters = compat_ptr(tmp.counters);
2177 repl->entries = compat_ptr(tmp.entries);
2178 return 0;
2179 }
2180
2181 static int compat_do_replace(struct net *net, void __user *user,
2182 unsigned int len)
2183 {
2184 int ret, i, countersize, size64;
2185 struct ebt_table_info *newinfo;
2186 struct ebt_replace tmp;
2187 struct ebt_entries_buf_state state;
2188 void *entries_tmp;
2189
2190 ret = compat_copy_ebt_replace_from_user(&tmp, user, len);
2191 if (ret) {
2192 /* try real handler in case userland supplied needed padding */
2193 if (ret == -EINVAL && do_replace(net, user, len) == 0)
2194 ret = 0;
2195 return ret;
2196 }
2197
2198 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
2199 newinfo = vmalloc(sizeof(*newinfo) + countersize);
2200 if (!newinfo)
2201 return -ENOMEM;
2202
2203 if (countersize)
2204 memset(newinfo->counters, 0, countersize);
2205
2206 memset(&state, 0, sizeof(state));
2207
2208 newinfo->entries = vmalloc(tmp.entries_size);
2209 if (!newinfo->entries) {
2210 ret = -ENOMEM;
2211 goto free_newinfo;
2212 }
2213 if (copy_from_user(
2214 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
2215 ret = -EFAULT;
2216 goto free_entries;
2217 }
2218
2219 entries_tmp = newinfo->entries;
2220
2221 xt_compat_lock(NFPROTO_BRIDGE);
2222
2223 xt_compat_init_offsets(NFPROTO_BRIDGE, tmp.nentries);
2224 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2225 if (ret < 0)
2226 goto out_unlock;
2227
2228 pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
2229 tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
2230 xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
2231
2232 size64 = ret;
2233 newinfo->entries = vmalloc(size64);
2234 if (!newinfo->entries) {
2235 vfree(entries_tmp);
2236 ret = -ENOMEM;
2237 goto out_unlock;
2238 }
2239
2240 memset(&state, 0, sizeof(state));
2241 state.buf_kern_start = newinfo->entries;
2242 state.buf_kern_len = size64;
2243
2244 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2245 BUG_ON(ret < 0); /* parses same data again */
2246
2247 vfree(entries_tmp);
2248 tmp.entries_size = size64;
2249
2250 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
2251 char __user *usrptr;
2252 if (tmp.hook_entry[i]) {
2253 unsigned int delta;
2254 usrptr = (char __user *) tmp.hook_entry[i];
2255 delta = usrptr - tmp.entries;
2256 usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta);
2257 tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
2258 }
2259 }
2260
2261 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2262 xt_compat_unlock(NFPROTO_BRIDGE);
2263
2264 ret = do_replace_finish(net, &tmp, newinfo);
2265 if (ret == 0)
2266 return ret;
2267 free_entries:
2268 vfree(newinfo->entries);
2269 free_newinfo:
2270 vfree(newinfo);
2271 return ret;
2272 out_unlock:
2273 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2274 xt_compat_unlock(NFPROTO_BRIDGE);
2275 goto free_entries;
2276 }
2277
2278 static int compat_update_counters(struct net *net, void __user *user,
2279 unsigned int len)
2280 {
2281 struct compat_ebt_replace hlp;
2282
2283 if (copy_from_user(&hlp, user, sizeof(hlp)))
2284 return -EFAULT;
2285
2286 /* try real handler in case userland supplied needed padding */
2287 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
2288 return update_counters(net, user, len);
2289
2290 return do_update_counters(net, hlp.name, compat_ptr(hlp.counters),
2291 hlp.num_counters, user, len);
2292 }
2293
2294 static int compat_do_ebt_set_ctl(struct sock *sk,
2295 int cmd, void __user *user, unsigned int len)
2296 {
2297 int ret;
2298 struct net *net = sock_net(sk);
2299
2300 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2301 return -EPERM;
2302
2303 switch (cmd) {
2304 case EBT_SO_SET_ENTRIES:
2305 ret = compat_do_replace(net, user, len);
2306 break;
2307 case EBT_SO_SET_COUNTERS:
2308 ret = compat_update_counters(net, user, len);
2309 break;
2310 default:
2311 ret = -EINVAL;
2312 }
2313 return ret;
2314 }
2315
2316 static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
2317 void __user *user, int *len)
2318 {
2319 int ret;
2320 struct compat_ebt_replace tmp;
2321 struct ebt_table *t;
2322 struct net *net = sock_net(sk);
2323
2324 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2325 return -EPERM;
2326
2327 /* try real handler in case userland supplied needed padding */
2328 if ((cmd == EBT_SO_GET_INFO ||
2329 cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp))
2330 return do_ebt_get_ctl(sk, cmd, user, len);
2331
2332 if (copy_from_user(&tmp, user, sizeof(tmp)))
2333 return -EFAULT;
2334
2335 tmp.name[sizeof(tmp.name) - 1] = '\0';
2336
2337 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
2338 if (!t)
2339 return ret;
2340
2341 xt_compat_lock(NFPROTO_BRIDGE);
2342 switch (cmd) {
2343 case EBT_SO_GET_INFO:
2344 tmp.nentries = t->private->nentries;
2345 ret = compat_table_info(t->private, &tmp);
2346 if (ret)
2347 goto out;
2348 tmp.valid_hooks = t->valid_hooks;
2349
2350 if (copy_to_user(user, &tmp, *len) != 0) {
2351 ret = -EFAULT;
2352 break;
2353 }
2354 ret = 0;
2355 break;
2356 case EBT_SO_GET_INIT_INFO:
2357 tmp.nentries = t->table->nentries;
2358 tmp.entries_size = t->table->entries_size;
2359 tmp.valid_hooks = t->table->valid_hooks;
2360
2361 if (copy_to_user(user, &tmp, *len) != 0) {
2362 ret = -EFAULT;
2363 break;
2364 }
2365 ret = 0;
2366 break;
2367 case EBT_SO_GET_ENTRIES:
2368 case EBT_SO_GET_INIT_ENTRIES:
2369 /* try real handler first in case of userland-side padding.
2370 * in case we are dealing with an 'ordinary' 32 bit binary
2371 * without 64bit compatibility padding, this will fail right
2372 * after copy_from_user when the *len argument is validated.
2373 *
2374 * the compat_ variant needs to do one pass over the kernel
2375 * data set to adjust for size differences before it the check.
2376 */
2377 if (copy_everything_to_user(t, user, len, cmd) == 0)
2378 ret = 0;
2379 else
2380 ret = compat_copy_everything_to_user(t, user, len, cmd);
2381 break;
2382 default:
2383 ret = -EINVAL;
2384 }
2385 out:
2386 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2387 xt_compat_unlock(NFPROTO_BRIDGE);
2388 mutex_unlock(&ebt_mutex);
2389 return ret;
2390 }
2391 #endif
2392
2393 static struct nf_sockopt_ops ebt_sockopts = {
2394 .pf = PF_INET,
2395 .set_optmin = EBT_BASE_CTL,
2396 .set_optmax = EBT_SO_SET_MAX + 1,
2397 .set = do_ebt_set_ctl,
2398 #ifdef CONFIG_COMPAT
2399 .compat_set = compat_do_ebt_set_ctl,
2400 #endif
2401 .get_optmin = EBT_BASE_CTL,
2402 .get_optmax = EBT_SO_GET_MAX + 1,
2403 .get = do_ebt_get_ctl,
2404 #ifdef CONFIG_COMPAT
2405 .compat_get = compat_do_ebt_get_ctl,
2406 #endif
2407 .owner = THIS_MODULE,
2408 };
2409
2410 static int __init ebtables_init(void)
2411 {
2412 int ret;
2413
2414 ret = xt_register_target(&ebt_standard_target);
2415 if (ret < 0)
2416 return ret;
2417 ret = nf_register_sockopt(&ebt_sockopts);
2418 if (ret < 0) {
2419 xt_unregister_target(&ebt_standard_target);
2420 return ret;
2421 }
2422
2423 printk(KERN_INFO "Ebtables v2.0 registered\n");
2424 return 0;
2425 }
2426
2427 static void __exit ebtables_fini(void)
2428 {
2429 nf_unregister_sockopt(&ebt_sockopts);
2430 xt_unregister_target(&ebt_standard_target);
2431 printk(KERN_INFO "Ebtables v2.0 unregistered\n");
2432 }
2433
2434 EXPORT_SYMBOL(ebt_register_table);
2435 EXPORT_SYMBOL(ebt_unregister_table);
2436 EXPORT_SYMBOL(ebt_do_table);
2437 module_init(ebtables_init);
2438 module_exit(ebtables_fini);
2439 MODULE_LICENSE("GPL");
Linux with added FPC-III support