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break out numa_maps gather_pte_stats() checks
[linux-2.6.git] / net / bridge / netfilter / ebtables.c
blob5864cc49136993d9de12f4c0f9110ab2dbcf1025
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) >= 1536, 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 ret = -EFAULT;
1048 }
1049 else
1050 ret = 0;
1051
1052 /* decrease module count and free resources */
1053 EBT_ENTRY_ITERATE(table->entries, table->entries_size,
1054 ebt_cleanup_entry, net, NULL);
1055
1056 vfree(table->entries);
1057 if (table->chainstack) {
1058 for_each_possible_cpu(i)
1059 vfree(table->chainstack[i]);
1060 vfree(table->chainstack);
1061 }
1062 vfree(table);
1063
1064 vfree(counterstmp);
1065 return ret;
1066
1067 free_unlock:
1068 mutex_unlock(&ebt_mutex);
1069 free_iterate:
1070 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
1071 ebt_cleanup_entry, net, NULL);
1072 free_counterstmp:
1073 vfree(counterstmp);
1074 /* can be initialized in translate_table() */
1075 if (newinfo->chainstack) {
1076 for_each_possible_cpu(i)
1077 vfree(newinfo->chainstack[i]);
1078 vfree(newinfo->chainstack);
1079 }
1080 return ret;
1081 }
1082
1083 /* replace the table */
1084 static int do_replace(struct net *net, const void __user *user,
1085 unsigned int len)
1086 {
1087 int ret, countersize;
1088 struct ebt_table_info *newinfo;
1089 struct ebt_replace tmp;
1090
1091 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1092 return -EFAULT;
1093
1094 if (len != sizeof(tmp) + tmp.entries_size) {
1095 BUGPRINT("Wrong len argument\n");
1096 return -EINVAL;
1097 }
1098
1099 if (tmp.entries_size == 0) {
1100 BUGPRINT("Entries_size never zero\n");
1101 return -EINVAL;
1102 }
1103 /* overflow check */
1104 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
1105 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
1106 return -ENOMEM;
1107 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
1108 return -ENOMEM;
1109
1110 tmp.name[sizeof(tmp.name) - 1] = 0;
1111
1112 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
1113 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1114 if (!newinfo)
1115 return -ENOMEM;
1116
1117 if (countersize)
1118 memset(newinfo->counters, 0, countersize);
1119
1120 newinfo->entries = vmalloc(tmp.entries_size);
1121 if (!newinfo->entries) {
1122 ret = -ENOMEM;
1123 goto free_newinfo;
1124 }
1125 if (copy_from_user(
1126 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
1127 BUGPRINT("Couldn't copy entries from userspace\n");
1128 ret = -EFAULT;
1129 goto free_entries;
1130 }
1131
1132 ret = do_replace_finish(net, &tmp, newinfo);
1133 if (ret == 0)
1134 return ret;
1135 free_entries:
1136 vfree(newinfo->entries);
1137 free_newinfo:
1138 vfree(newinfo);
1139 return ret;
1140 }
1141
1142 struct ebt_table *
1143 ebt_register_table(struct net *net, const struct ebt_table *input_table)
1144 {
1145 struct ebt_table_info *newinfo;
1146 struct ebt_table *t, *table;
1147 struct ebt_replace_kernel *repl;
1148 int ret, i, countersize;
1149 void *p;
1150
1151 if (input_table == NULL || (repl = input_table->table) == NULL ||
1152 repl->entries == NULL || repl->entries_size == 0 ||
1153 repl->counters != NULL || input_table->private != NULL) {
1154 BUGPRINT("Bad table data for ebt_register_table!!!\n");
1155 return ERR_PTR(-EINVAL);
1156 }
1157
1158 /* Don't add one table to multiple lists. */
1159 table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL);
1160 if (!table) {
1161 ret = -ENOMEM;
1162 goto out;
1163 }
1164
1165 countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
1166 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1167 ret = -ENOMEM;
1168 if (!newinfo)
1169 goto free_table;
1170
1171 p = vmalloc(repl->entries_size);
1172 if (!p)
1173 goto free_newinfo;
1174
1175 memcpy(p, repl->entries, repl->entries_size);
1176 newinfo->entries = p;
1177
1178 newinfo->entries_size = repl->entries_size;
1179 newinfo->nentries = repl->nentries;
1180
1181 if (countersize)
1182 memset(newinfo->counters, 0, countersize);
1183
1184 /* fill in newinfo and parse the entries */
1185 newinfo->chainstack = NULL;
1186 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1187 if ((repl->valid_hooks & (1 << i)) == 0)
1188 newinfo->hook_entry[i] = NULL;
1189 else
1190 newinfo->hook_entry[i] = p +
1191 ((char *)repl->hook_entry[i] - repl->entries);
1192 }
1193 ret = translate_table(net, repl->name, newinfo);
1194 if (ret != 0) {
1195 BUGPRINT("Translate_table failed\n");
1196 goto free_chainstack;
1197 }
1198
1199 if (table->check && table->check(newinfo, table->valid_hooks)) {
1200 BUGPRINT("The table doesn't like its own initial data, lol\n");
1201 ret = -EINVAL;
1202 goto free_chainstack;
1203 }
1204
1205 table->private = newinfo;
1206 rwlock_init(&table->lock);
1207 ret = mutex_lock_interruptible(&ebt_mutex);
1208 if (ret != 0)
1209 goto free_chainstack;
1210
1211 list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
1212 if (strcmp(t->name, table->name) == 0) {
1213 ret = -EEXIST;
1214 BUGPRINT("Table name already exists\n");
1215 goto free_unlock;
1216 }
1217 }
1218
1219 /* Hold a reference count if the chains aren't empty */
1220 if (newinfo->nentries && !try_module_get(table->me)) {
1221 ret = -ENOENT;
1222 goto free_unlock;
1223 }
1224 list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
1225 mutex_unlock(&ebt_mutex);
1226 return table;
1227 free_unlock:
1228 mutex_unlock(&ebt_mutex);
1229 free_chainstack:
1230 if (newinfo->chainstack) {
1231 for_each_possible_cpu(i)
1232 vfree(newinfo->chainstack[i]);
1233 vfree(newinfo->chainstack);
1234 }
1235 vfree(newinfo->entries);
1236 free_newinfo:
1237 vfree(newinfo);
1238 free_table:
1239 kfree(table);
1240 out:
1241 return ERR_PTR(ret);
1242 }
1243
1244 void ebt_unregister_table(struct net *net, struct ebt_table *table)
1245 {
1246 int i;
1247
1248 if (!table) {
1249 BUGPRINT("Request to unregister NULL table!!!\n");
1250 return;
1251 }
1252 mutex_lock(&ebt_mutex);
1253 list_del(&table->list);
1254 mutex_unlock(&ebt_mutex);
1255 EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
1256 ebt_cleanup_entry, net, NULL);
1257 if (table->private->nentries)
1258 module_put(table->me);
1259 vfree(table->private->entries);
1260 if (table->private->chainstack) {
1261 for_each_possible_cpu(i)
1262 vfree(table->private->chainstack[i]);
1263 vfree(table->private->chainstack);
1264 }
1265 vfree(table->private);
1266 kfree(table);
1267 }
1268
1269 /* userspace just supplied us with counters */
1270 static int do_update_counters(struct net *net, const char *name,
1271 struct ebt_counter __user *counters,
1272 unsigned int num_counters,
1273 const void __user *user, unsigned int len)
1274 {
1275 int i, ret;
1276 struct ebt_counter *tmp;
1277 struct ebt_table *t;
1278
1279 if (num_counters == 0)
1280 return -EINVAL;
1281
1282 tmp = vmalloc(num_counters * sizeof(*tmp));
1283 if (!tmp)
1284 return -ENOMEM;
1285
1286 t = find_table_lock(net, name, &ret, &ebt_mutex);
1287 if (!t)
1288 goto free_tmp;
1289
1290 if (num_counters != t->private->nentries) {
1291 BUGPRINT("Wrong nr of counters\n");
1292 ret = -EINVAL;
1293 goto unlock_mutex;
1294 }
1295
1296 if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) {
1297 ret = -EFAULT;
1298 goto unlock_mutex;
1299 }
1300
1301 /* we want an atomic add of the counters */
1302 write_lock_bh(&t->lock);
1303
1304 /* we add to the counters of the first cpu */
1305 for (i = 0; i < num_counters; i++) {
1306 t->private->counters[i].pcnt += tmp[i].pcnt;
1307 t->private->counters[i].bcnt += tmp[i].bcnt;
1308 }
1309
1310 write_unlock_bh(&t->lock);
1311 ret = 0;
1312 unlock_mutex:
1313 mutex_unlock(&ebt_mutex);
1314 free_tmp:
1315 vfree(tmp);
1316 return ret;
1317 }
1318
1319 static int update_counters(struct net *net, const void __user *user,
1320 unsigned int len)
1321 {
1322 struct ebt_replace hlp;
1323
1324 if (copy_from_user(&hlp, user, sizeof(hlp)))
1325 return -EFAULT;
1326
1327 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
1328 return -EINVAL;
1329
1330 return do_update_counters(net, hlp.name, hlp.counters,
1331 hlp.num_counters, user, len);
1332 }
1333
1334 static inline int ebt_make_matchname(const struct ebt_entry_match *m,
1335 const char *base, char __user *ubase)
1336 {
1337 char __user *hlp = ubase + ((char *)m - base);
1338 if (copy_to_user(hlp, m->u.match->name, EBT_FUNCTION_MAXNAMELEN))
1339 return -EFAULT;
1340 return 0;
1341 }
1342
1343 static inline int ebt_make_watchername(const struct ebt_entry_watcher *w,
1344 const char *base, char __user *ubase)
1345 {
1346 char __user *hlp = ubase + ((char *)w - base);
1347 if (copy_to_user(hlp , w->u.watcher->name, EBT_FUNCTION_MAXNAMELEN))
1348 return -EFAULT;
1349 return 0;
1350 }
1351
1352 static inline int
1353 ebt_make_names(struct ebt_entry *e, const char *base, char __user *ubase)
1354 {
1355 int ret;
1356 char __user *hlp;
1357 const struct ebt_entry_target *t;
1358
1359 if (e->bitmask == 0)
1360 return 0;
1361
1362 hlp = ubase + (((char *)e + e->target_offset) - base);
1363 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
1364
1365 ret = EBT_MATCH_ITERATE(e, ebt_make_matchname, base, ubase);
1366 if (ret != 0)
1367 return ret;
1368 ret = EBT_WATCHER_ITERATE(e, ebt_make_watchername, base, ubase);
1369 if (ret != 0)
1370 return ret;
1371 if (copy_to_user(hlp, t->u.target->name, EBT_FUNCTION_MAXNAMELEN))
1372 return -EFAULT;
1373 return 0;
1374 }
1375
1376 static int copy_counters_to_user(struct ebt_table *t,
1377 const struct ebt_counter *oldcounters,
1378 void __user *user, unsigned int num_counters,
1379 unsigned int nentries)
1380 {
1381 struct ebt_counter *counterstmp;
1382 int ret = 0;
1383
1384 /* userspace might not need the counters */
1385 if (num_counters == 0)
1386 return 0;
1387
1388 if (num_counters != nentries) {
1389 BUGPRINT("Num_counters wrong\n");
1390 return -EINVAL;
1391 }
1392
1393 counterstmp = vmalloc(nentries * sizeof(*counterstmp));
1394 if (!counterstmp)
1395 return -ENOMEM;
1396
1397 write_lock_bh(&t->lock);
1398 get_counters(oldcounters, counterstmp, nentries);
1399 write_unlock_bh(&t->lock);
1400
1401 if (copy_to_user(user, counterstmp,
1402 nentries * sizeof(struct ebt_counter)))
1403 ret = -EFAULT;
1404 vfree(counterstmp);
1405 return ret;
1406 }
1407
1408 /* called with ebt_mutex locked */
1409 static int copy_everything_to_user(struct ebt_table *t, void __user *user,
1410 const int *len, int cmd)
1411 {
1412 struct ebt_replace tmp;
1413 const struct ebt_counter *oldcounters;
1414 unsigned int entries_size, nentries;
1415 int ret;
1416 char *entries;
1417
1418 if (cmd == EBT_SO_GET_ENTRIES) {
1419 entries_size = t->private->entries_size;
1420 nentries = t->private->nentries;
1421 entries = t->private->entries;
1422 oldcounters = t->private->counters;
1423 } else {
1424 entries_size = t->table->entries_size;
1425 nentries = t->table->nentries;
1426 entries = t->table->entries;
1427 oldcounters = t->table->counters;
1428 }
1429
1430 if (copy_from_user(&tmp, user, sizeof(tmp)))
1431 return -EFAULT;
1432
1433 if (*len != sizeof(struct ebt_replace) + entries_size +
1434 (tmp.num_counters? nentries * sizeof(struct ebt_counter): 0))
1435 return -EINVAL;
1436
1437 if (tmp.nentries != nentries) {
1438 BUGPRINT("Nentries wrong\n");
1439 return -EINVAL;
1440 }
1441
1442 if (tmp.entries_size != entries_size) {
1443 BUGPRINT("Wrong size\n");
1444 return -EINVAL;
1445 }
1446
1447 ret = copy_counters_to_user(t, oldcounters, tmp.counters,
1448 tmp.num_counters, nentries);
1449 if (ret)
1450 return ret;
1451
1452 if (copy_to_user(tmp.entries, entries, entries_size)) {
1453 BUGPRINT("Couldn't copy entries to userspace\n");
1454 return -EFAULT;
1455 }
1456 /* set the match/watcher/target names right */
1457 return EBT_ENTRY_ITERATE(entries, entries_size,
1458 ebt_make_names, entries, tmp.entries);
1459 }
1460
1461 static int do_ebt_set_ctl(struct sock *sk,
1462 int cmd, void __user *user, unsigned int len)
1463 {
1464 int ret;
1465
1466 if (!capable(CAP_NET_ADMIN))
1467 return -EPERM;
1468
1469 switch(cmd) {
1470 case EBT_SO_SET_ENTRIES:
1471 ret = do_replace(sock_net(sk), user, len);
1472 break;
1473 case EBT_SO_SET_COUNTERS:
1474 ret = update_counters(sock_net(sk), user, len);
1475 break;
1476 default:
1477 ret = -EINVAL;
1478 }
1479 return ret;
1480 }
1481
1482 static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1483 {
1484 int ret;
1485 struct ebt_replace tmp;
1486 struct ebt_table *t;
1487
1488 if (!capable(CAP_NET_ADMIN))
1489 return -EPERM;
1490
1491 if (copy_from_user(&tmp, user, sizeof(tmp)))
1492 return -EFAULT;
1493
1494 t = find_table_lock(sock_net(sk), tmp.name, &ret, &ebt_mutex);
1495 if (!t)
1496 return ret;
1497
1498 switch(cmd) {
1499 case EBT_SO_GET_INFO:
1500 case EBT_SO_GET_INIT_INFO:
1501 if (*len != sizeof(struct ebt_replace)){
1502 ret = -EINVAL;
1503 mutex_unlock(&ebt_mutex);
1504 break;
1505 }
1506 if (cmd == EBT_SO_GET_INFO) {
1507 tmp.nentries = t->private->nentries;
1508 tmp.entries_size = t->private->entries_size;
1509 tmp.valid_hooks = t->valid_hooks;
1510 } else {
1511 tmp.nentries = t->table->nentries;
1512 tmp.entries_size = t->table->entries_size;
1513 tmp.valid_hooks = t->table->valid_hooks;
1514 }
1515 mutex_unlock(&ebt_mutex);
1516 if (copy_to_user(user, &tmp, *len) != 0){
1517 BUGPRINT("c2u Didn't work\n");
1518 ret = -EFAULT;
1519 break;
1520 }
1521 ret = 0;
1522 break;
1523
1524 case EBT_SO_GET_ENTRIES:
1525 case EBT_SO_GET_INIT_ENTRIES:
1526 ret = copy_everything_to_user(t, user, len, cmd);
1527 mutex_unlock(&ebt_mutex);
1528 break;
1529
1530 default:
1531 mutex_unlock(&ebt_mutex);
1532 ret = -EINVAL;
1533 }
1534
1535 return ret;
1536 }
1537
1538 #ifdef CONFIG_COMPAT
1539 /* 32 bit-userspace compatibility definitions. */
1540 struct compat_ebt_replace {
1541 char name[EBT_TABLE_MAXNAMELEN];
1542 compat_uint_t valid_hooks;
1543 compat_uint_t nentries;
1544 compat_uint_t entries_size;
1545 /* start of the chains */
1546 compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
1547 /* nr of counters userspace expects back */
1548 compat_uint_t num_counters;
1549 /* where the kernel will put the old counters. */
1550 compat_uptr_t counters;
1551 compat_uptr_t entries;
1552 };
1553
1554 /* struct ebt_entry_match, _target and _watcher have same layout */
1555 struct compat_ebt_entry_mwt {
1556 union {
1557 char name[EBT_FUNCTION_MAXNAMELEN];
1558 compat_uptr_t ptr;
1559 } u;
1560 compat_uint_t match_size;
1561 compat_uint_t data[0];
1562 };
1563
1564 /* account for possible padding between match_size and ->data */
1565 static int ebt_compat_entry_padsize(void)
1566 {
1567 BUILD_BUG_ON(XT_ALIGN(sizeof(struct ebt_entry_match)) <
1568 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt)));
1569 return (int) XT_ALIGN(sizeof(struct ebt_entry_match)) -
1570 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt));
1571 }
1572
1573 static int ebt_compat_match_offset(const struct xt_match *match,
1574 unsigned int userlen)
1575 {
1576 /*
1577 * ebt_among needs special handling. The kernel .matchsize is
1578 * set to -1 at registration time; at runtime an EBT_ALIGN()ed
1579 * value is expected.
1580 * Example: userspace sends 4500, ebt_among.c wants 4504.
1581 */
1582 if (unlikely(match->matchsize == -1))
1583 return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
1584 return xt_compat_match_offset(match);
1585 }
1586
1587 static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
1588 unsigned int *size)
1589 {
1590 const struct xt_match *match = m->u.match;
1591 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1592 int off = ebt_compat_match_offset(match, m->match_size);
1593 compat_uint_t msize = m->match_size - off;
1594
1595 BUG_ON(off >= m->match_size);
1596
1597 if (copy_to_user(cm->u.name, match->name,
1598 strlen(match->name) + 1) || put_user(msize, &cm->match_size))
1599 return -EFAULT;
1600
1601 if (match->compat_to_user) {
1602 if (match->compat_to_user(cm->data, m->data))
1603 return -EFAULT;
1604 } else if (copy_to_user(cm->data, m->data, msize))
1605 return -EFAULT;
1606
1607 *size -= ebt_compat_entry_padsize() + off;
1608 *dstptr = cm->data;
1609 *dstptr += msize;
1610 return 0;
1611 }
1612
1613 static int compat_target_to_user(struct ebt_entry_target *t,
1614 void __user **dstptr,
1615 unsigned int *size)
1616 {
1617 const struct xt_target *target = t->u.target;
1618 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1619 int off = xt_compat_target_offset(target);
1620 compat_uint_t tsize = t->target_size - off;
1621
1622 BUG_ON(off >= t->target_size);
1623
1624 if (copy_to_user(cm->u.name, target->name,
1625 strlen(target->name) + 1) || put_user(tsize, &cm->match_size))
1626 return -EFAULT;
1627
1628 if (target->compat_to_user) {
1629 if (target->compat_to_user(cm->data, t->data))
1630 return -EFAULT;
1631 } else if (copy_to_user(cm->data, t->data, tsize))
1632 return -EFAULT;
1633
1634 *size -= ebt_compat_entry_padsize() + off;
1635 *dstptr = cm->data;
1636 *dstptr += tsize;
1637 return 0;
1638 }
1639
1640 static int compat_watcher_to_user(struct ebt_entry_watcher *w,
1641 void __user **dstptr,
1642 unsigned int *size)
1643 {
1644 return compat_target_to_user((struct ebt_entry_target *)w,
1645 dstptr, size);
1646 }
1647
1648 static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
1649 unsigned int *size)
1650 {
1651 struct ebt_entry_target *t;
1652 struct ebt_entry __user *ce;
1653 u32 watchers_offset, target_offset, next_offset;
1654 compat_uint_t origsize;
1655 int ret;
1656
1657 if (e->bitmask == 0) {
1658 if (*size < sizeof(struct ebt_entries))
1659 return -EINVAL;
1660 if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries)))
1661 return -EFAULT;
1662
1663 *dstptr += sizeof(struct ebt_entries);
1664 *size -= sizeof(struct ebt_entries);
1665 return 0;
1666 }
1667
1668 if (*size < sizeof(*ce))
1669 return -EINVAL;
1670
1671 ce = (struct ebt_entry __user *)*dstptr;
1672 if (copy_to_user(ce, e, sizeof(*ce)))
1673 return -EFAULT;
1674
1675 origsize = *size;
1676 *dstptr += sizeof(*ce);
1677
1678 ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
1679 if (ret)
1680 return ret;
1681 watchers_offset = e->watchers_offset - (origsize - *size);
1682
1683 ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
1684 if (ret)
1685 return ret;
1686 target_offset = e->target_offset - (origsize - *size);
1687
1688 t = (struct ebt_entry_target *) ((char *) e + e->target_offset);
1689
1690 ret = compat_target_to_user(t, dstptr, size);
1691 if (ret)
1692 return ret;
1693 next_offset = e->next_offset - (origsize - *size);
1694
1695 if (put_user(watchers_offset, &ce->watchers_offset) ||
1696 put_user(target_offset, &ce->target_offset) ||
1697 put_user(next_offset, &ce->next_offset))
1698 return -EFAULT;
1699
1700 *size -= sizeof(*ce);
1701 return 0;
1702 }
1703
1704 static int compat_calc_match(struct ebt_entry_match *m, int *off)
1705 {
1706 *off += ebt_compat_match_offset(m->u.match, m->match_size);
1707 *off += ebt_compat_entry_padsize();
1708 return 0;
1709 }
1710
1711 static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
1712 {
1713 *off += xt_compat_target_offset(w->u.watcher);
1714 *off += ebt_compat_entry_padsize();
1715 return 0;
1716 }
1717
1718 static int compat_calc_entry(const struct ebt_entry *e,
1719 const struct ebt_table_info *info,
1720 const void *base,
1721 struct compat_ebt_replace *newinfo)
1722 {
1723 const struct ebt_entry_target *t;
1724 unsigned int entry_offset;
1725 int off, ret, i;
1726
1727 if (e->bitmask == 0)
1728 return 0;
1729
1730 off = 0;
1731 entry_offset = (void *)e - base;
1732
1733 EBT_MATCH_ITERATE(e, compat_calc_match, &off);
1734 EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
1735
1736 t = (const struct ebt_entry_target *) ((char *) e + e->target_offset);
1737
1738 off += xt_compat_target_offset(t->u.target);
1739 off += ebt_compat_entry_padsize();
1740
1741 newinfo->entries_size -= off;
1742
1743 ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off);
1744 if (ret)
1745 return ret;
1746
1747 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1748 const void *hookptr = info->hook_entry[i];
1749 if (info->hook_entry[i] &&
1750 (e < (struct ebt_entry *)(base - hookptr))) {
1751 newinfo->hook_entry[i] -= off;
1752 pr_debug("0x%08X -> 0x%08X\n",
1753 newinfo->hook_entry[i] + off,
1754 newinfo->hook_entry[i]);
1755 }
1756 }
1757
1758 return 0;
1759 }
1760
1761
1762 static int compat_table_info(const struct ebt_table_info *info,
1763 struct compat_ebt_replace *newinfo)
1764 {
1765 unsigned int size = info->entries_size;
1766 const void *entries = info->entries;
1767
1768 newinfo->entries_size = size;
1769
1770 xt_compat_init_offsets(NFPROTO_BRIDGE, info->nentries);
1771 return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
1772 entries, newinfo);
1773 }
1774
1775 static int compat_copy_everything_to_user(struct ebt_table *t,
1776 void __user *user, int *len, int cmd)
1777 {
1778 struct compat_ebt_replace repl, tmp;
1779 struct ebt_counter *oldcounters;
1780 struct ebt_table_info tinfo;
1781 int ret;
1782 void __user *pos;
1783
1784 memset(&tinfo, 0, sizeof(tinfo));
1785
1786 if (cmd == EBT_SO_GET_ENTRIES) {
1787 tinfo.entries_size = t->private->entries_size;
1788 tinfo.nentries = t->private->nentries;
1789 tinfo.entries = t->private->entries;
1790 oldcounters = t->private->counters;
1791 } else {
1792 tinfo.entries_size = t->table->entries_size;
1793 tinfo.nentries = t->table->nentries;
1794 tinfo.entries = t->table->entries;
1795 oldcounters = t->table->counters;
1796 }
1797
1798 if (copy_from_user(&tmp, user, sizeof(tmp)))
1799 return -EFAULT;
1800
1801 if (tmp.nentries != tinfo.nentries ||
1802 (tmp.num_counters && tmp.num_counters != tinfo.nentries))
1803 return -EINVAL;
1804
1805 memcpy(&repl, &tmp, sizeof(repl));
1806 if (cmd == EBT_SO_GET_ENTRIES)
1807 ret = compat_table_info(t->private, &repl);
1808 else
1809 ret = compat_table_info(&tinfo, &repl);
1810 if (ret)
1811 return ret;
1812
1813 if (*len != sizeof(tmp) + repl.entries_size +
1814 (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
1815 pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
1816 *len, tinfo.entries_size, repl.entries_size);
1817 return -EINVAL;
1818 }
1819
1820 /* userspace might not need the counters */
1821 ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters),
1822 tmp.num_counters, tinfo.nentries);
1823 if (ret)
1824 return ret;
1825
1826 pos = compat_ptr(tmp.entries);
1827 return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
1828 compat_copy_entry_to_user, &pos, &tmp.entries_size);
1829 }
1830
1831 struct ebt_entries_buf_state {
1832 char *buf_kern_start; /* kernel buffer to copy (translated) data to */
1833 u32 buf_kern_len; /* total size of kernel buffer */
1834 u32 buf_kern_offset; /* amount of data copied so far */
1835 u32 buf_user_offset; /* read position in userspace buffer */
1836 };
1837
1838 static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
1839 {
1840 state->buf_kern_offset += sz;
1841 return state->buf_kern_offset >= sz ? 0 : -EINVAL;
1842 }
1843
1844 static int ebt_buf_add(struct ebt_entries_buf_state *state,
1845 void *data, unsigned int sz)
1846 {
1847 if (state->buf_kern_start == NULL)
1848 goto count_only;
1849
1850 BUG_ON(state->buf_kern_offset + sz > state->buf_kern_len);
1851
1852 memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz);
1853
1854 count_only:
1855 state->buf_user_offset += sz;
1856 return ebt_buf_count(state, sz);
1857 }
1858
1859 static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz)
1860 {
1861 char *b = state->buf_kern_start;
1862
1863 BUG_ON(b && state->buf_kern_offset > state->buf_kern_len);
1864
1865 if (b != NULL && sz > 0)
1866 memset(b + state->buf_kern_offset, 0, sz);
1867 /* do not adjust ->buf_user_offset here, we added kernel-side padding */
1868 return ebt_buf_count(state, sz);
1869 }
1870
1871 enum compat_mwt {
1872 EBT_COMPAT_MATCH,
1873 EBT_COMPAT_WATCHER,
1874 EBT_COMPAT_TARGET,
1875 };
1876
1877 static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt,
1878 enum compat_mwt compat_mwt,
1879 struct ebt_entries_buf_state *state,
1880 const unsigned char *base)
1881 {
1882 char name[EBT_FUNCTION_MAXNAMELEN];
1883 struct xt_match *match;
1884 struct xt_target *wt;
1885 void *dst = NULL;
1886 int off, pad = 0;
1887 unsigned int size_kern, match_size = mwt->match_size;
1888
1889 strlcpy(name, mwt->u.name, sizeof(name));
1890
1891 if (state->buf_kern_start)
1892 dst = state->buf_kern_start + state->buf_kern_offset;
1893
1894 switch (compat_mwt) {
1895 case EBT_COMPAT_MATCH:
1896 match = try_then_request_module(xt_find_match(NFPROTO_BRIDGE,
1897 name, 0), "ebt_%s", name);
1898 if (match == NULL)
1899 return -ENOENT;
1900 if (IS_ERR(match))
1901 return PTR_ERR(match);
1902
1903 off = ebt_compat_match_offset(match, match_size);
1904 if (dst) {
1905 if (match->compat_from_user)
1906 match->compat_from_user(dst, mwt->data);
1907 else
1908 memcpy(dst, mwt->data, match_size);
1909 }
1910
1911 size_kern = match->matchsize;
1912 if (unlikely(size_kern == -1))
1913 size_kern = match_size;
1914 module_put(match->me);
1915 break;
1916 case EBT_COMPAT_WATCHER: /* fallthrough */
1917 case EBT_COMPAT_TARGET:
1918 wt = try_then_request_module(xt_find_target(NFPROTO_BRIDGE,
1919 name, 0), "ebt_%s", name);
1920 if (wt == NULL)
1921 return -ENOENT;
1922 if (IS_ERR(wt))
1923 return PTR_ERR(wt);
1924 off = xt_compat_target_offset(wt);
1925
1926 if (dst) {
1927 if (wt->compat_from_user)
1928 wt->compat_from_user(dst, mwt->data);
1929 else
1930 memcpy(dst, mwt->data, match_size);
1931 }
1932
1933 size_kern = wt->targetsize;
1934 module_put(wt->me);
1935 break;
1936
1937 default:
1938 return -EINVAL;
1939 }
1940
1941 state->buf_kern_offset += match_size + off;
1942 state->buf_user_offset += match_size;
1943 pad = XT_ALIGN(size_kern) - size_kern;
1944
1945 if (pad > 0 && dst) {
1946 BUG_ON(state->buf_kern_len <= pad);
1947 BUG_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad);
1948 memset(dst + size_kern, 0, pad);
1949 }
1950 return off + match_size;
1951 }
1952
1953 /*
1954 * return size of all matches, watchers or target, including necessary
1955 * alignment and padding.
1956 */
1957 static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32,
1958 unsigned int size_left, enum compat_mwt type,
1959 struct ebt_entries_buf_state *state, const void *base)
1960 {
1961 int growth = 0;
1962 char *buf;
1963
1964 if (size_left == 0)
1965 return 0;
1966
1967 buf = (char *) match32;
1968
1969 while (size_left >= sizeof(*match32)) {
1970 struct ebt_entry_match *match_kern;
1971 int ret;
1972
1973 match_kern = (struct ebt_entry_match *) state->buf_kern_start;
1974 if (match_kern) {
1975 char *tmp;
1976 tmp = state->buf_kern_start + state->buf_kern_offset;
1977 match_kern = (struct ebt_entry_match *) tmp;
1978 }
1979 ret = ebt_buf_add(state, buf, sizeof(*match32));
1980 if (ret < 0)
1981 return ret;
1982 size_left -= sizeof(*match32);
1983
1984 /* add padding before match->data (if any) */
1985 ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize());
1986 if (ret < 0)
1987 return ret;
1988
1989 if (match32->match_size > size_left)
1990 return -EINVAL;
1991
1992 size_left -= match32->match_size;
1993
1994 ret = compat_mtw_from_user(match32, type, state, base);
1995 if (ret < 0)
1996 return ret;
1997
1998 BUG_ON(ret < match32->match_size);
1999 growth += ret - match32->match_size;
2000 growth += ebt_compat_entry_padsize();
2001
2002 buf += sizeof(*match32);
2003 buf += match32->match_size;
2004
2005 if (match_kern)
2006 match_kern->match_size = ret;
2007
2008 WARN_ON(type == EBT_COMPAT_TARGET && size_left);
2009 match32 = (struct compat_ebt_entry_mwt *) buf;
2010 }
2011
2012 return growth;
2013 }
2014
2015 /* called for all ebt_entry structures. */
2016 static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,
2017 unsigned int *total,
2018 struct ebt_entries_buf_state *state)
2019 {
2020 unsigned int i, j, startoff, new_offset = 0;
2021 /* stores match/watchers/targets & offset of next struct ebt_entry: */
2022 unsigned int offsets[4];
2023 unsigned int *offsets_update = NULL;
2024 int ret;
2025 char *buf_start;
2026
2027 if (*total < sizeof(struct ebt_entries))
2028 return -EINVAL;
2029
2030 if (!entry->bitmask) {
2031 *total -= sizeof(struct ebt_entries);
2032 return ebt_buf_add(state, entry, sizeof(struct ebt_entries));
2033 }
2034 if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
2035 return -EINVAL;
2036
2037 startoff = state->buf_user_offset;
2038 /* pull in most part of ebt_entry, it does not need to be changed. */
2039 ret = ebt_buf_add(state, entry,
2040 offsetof(struct ebt_entry, watchers_offset));
2041 if (ret < 0)
2042 return ret;
2043
2044 offsets[0] = sizeof(struct ebt_entry); /* matches come first */
2045 memcpy(&offsets[1], &entry->watchers_offset,
2046 sizeof(offsets) - sizeof(offsets[0]));
2047
2048 if (state->buf_kern_start) {
2049 buf_start = state->buf_kern_start + state->buf_kern_offset;
2050 offsets_update = (unsigned int *) buf_start;
2051 }
2052 ret = ebt_buf_add(state, &offsets[1],
2053 sizeof(offsets) - sizeof(offsets[0]));
2054 if (ret < 0)
2055 return ret;
2056 buf_start = (char *) entry;
2057 /*
2058 * 0: matches offset, always follows ebt_entry.
2059 * 1: watchers offset, from ebt_entry structure
2060 * 2: target offset, from ebt_entry structure
2061 * 3: next ebt_entry offset, from ebt_entry structure
2062 *
2063 * offsets are relative to beginning of struct ebt_entry (i.e., 0).
2064 */
2065 for (i = 0, j = 1 ; j < 4 ; j++, i++) {
2066 struct compat_ebt_entry_mwt *match32;
2067 unsigned int size;
2068 char *buf = buf_start;
2069
2070 buf = buf_start + offsets[i];
2071 if (offsets[i] > offsets[j])
2072 return -EINVAL;
2073
2074 match32 = (struct compat_ebt_entry_mwt *) buf;
2075 size = offsets[j] - offsets[i];
2076 ret = ebt_size_mwt(match32, size, i, state, base);
2077 if (ret < 0)
2078 return ret;
2079 new_offset += ret;
2080 if (offsets_update && new_offset) {
2081 pr_debug("change offset %d to %d\n",
2082 offsets_update[i], offsets[j] + new_offset);
2083 offsets_update[i] = offsets[j] + new_offset;
2084 }
2085 }
2086
2087 if (state->buf_kern_start == NULL) {
2088 unsigned int offset = buf_start - (char *) base;
2089
2090 ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);
2091 if (ret < 0)
2092 return ret;
2093 }
2094
2095 startoff = state->buf_user_offset - startoff;
2096
2097 BUG_ON(*total < startoff);
2098 *total -= startoff;
2099 return 0;
2100 }
2101
2102 /*
2103 * repl->entries_size is the size of the ebt_entry blob in userspace.
2104 * It might need more memory when copied to a 64 bit kernel in case
2105 * userspace is 32-bit. So, first task: find out how much memory is needed.
2106 *
2107 * Called before validation is performed.
2108 */
2109 static int compat_copy_entries(unsigned char *data, unsigned int size_user,
2110 struct ebt_entries_buf_state *state)
2111 {
2112 unsigned int size_remaining = size_user;
2113 int ret;
2114
2115 ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
2116 &size_remaining, state);
2117 if (ret < 0)
2118 return ret;
2119
2120 WARN_ON(size_remaining);
2121 return state->buf_kern_offset;
2122 }
2123
2124
2125 static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
2126 void __user *user, unsigned int len)
2127 {
2128 struct compat_ebt_replace tmp;
2129 int i;
2130
2131 if (len < sizeof(tmp))
2132 return -EINVAL;
2133
2134 if (copy_from_user(&tmp, user, sizeof(tmp)))
2135 return -EFAULT;
2136
2137 if (len != sizeof(tmp) + tmp.entries_size)
2138 return -EINVAL;
2139
2140 if (tmp.entries_size == 0)
2141 return -EINVAL;
2142
2143 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
2144 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
2145 return -ENOMEM;
2146 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
2147 return -ENOMEM;
2148
2149 memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
2150
2151 /* starting with hook_entry, 32 vs. 64 bit structures are different */
2152 for (i = 0; i < NF_BR_NUMHOOKS; i++)
2153 repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]);
2154
2155 repl->num_counters = tmp.num_counters;
2156 repl->counters = compat_ptr(tmp.counters);
2157 repl->entries = compat_ptr(tmp.entries);
2158 return 0;
2159 }
2160
2161 static int compat_do_replace(struct net *net, void __user *user,
2162 unsigned int len)
2163 {
2164 int ret, i, countersize, size64;
2165 struct ebt_table_info *newinfo;
2166 struct ebt_replace tmp;
2167 struct ebt_entries_buf_state state;
2168 void *entries_tmp;
2169
2170 ret = compat_copy_ebt_replace_from_user(&tmp, user, len);
2171 if (ret) {
2172 /* try real handler in case userland supplied needed padding */
2173 if (ret == -EINVAL && do_replace(net, user, len) == 0)
2174 ret = 0;
2175 return ret;
2176 }
2177
2178 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
2179 newinfo = vmalloc(sizeof(*newinfo) + countersize);
2180 if (!newinfo)
2181 return -ENOMEM;
2182
2183 if (countersize)
2184 memset(newinfo->counters, 0, countersize);
2185
2186 memset(&state, 0, sizeof(state));
2187
2188 newinfo->entries = vmalloc(tmp.entries_size);
2189 if (!newinfo->entries) {
2190 ret = -ENOMEM;
2191 goto free_newinfo;
2192 }
2193 if (copy_from_user(
2194 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
2195 ret = -EFAULT;
2196 goto free_entries;
2197 }
2198
2199 entries_tmp = newinfo->entries;
2200
2201 xt_compat_lock(NFPROTO_BRIDGE);
2202
2203 xt_compat_init_offsets(NFPROTO_BRIDGE, tmp.nentries);
2204 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2205 if (ret < 0)
2206 goto out_unlock;
2207
2208 pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
2209 tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
2210 xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
2211
2212 size64 = ret;
2213 newinfo->entries = vmalloc(size64);
2214 if (!newinfo->entries) {
2215 vfree(entries_tmp);
2216 ret = -ENOMEM;
2217 goto out_unlock;
2218 }
2219
2220 memset(&state, 0, sizeof(state));
2221 state.buf_kern_start = newinfo->entries;
2222 state.buf_kern_len = size64;
2223
2224 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2225 BUG_ON(ret < 0); /* parses same data again */
2226
2227 vfree(entries_tmp);
2228 tmp.entries_size = size64;
2229
2230 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
2231 char __user *usrptr;
2232 if (tmp.hook_entry[i]) {
2233 unsigned int delta;
2234 usrptr = (char __user *) tmp.hook_entry[i];
2235 delta = usrptr - tmp.entries;
2236 usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta);
2237 tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
2238 }
2239 }
2240
2241 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2242 xt_compat_unlock(NFPROTO_BRIDGE);
2243
2244 ret = do_replace_finish(net, &tmp, newinfo);
2245 if (ret == 0)
2246 return ret;
2247 free_entries:
2248 vfree(newinfo->entries);
2249 free_newinfo:
2250 vfree(newinfo);
2251 return ret;
2252 out_unlock:
2253 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2254 xt_compat_unlock(NFPROTO_BRIDGE);
2255 goto free_entries;
2256 }
2257
2258 static int compat_update_counters(struct net *net, void __user *user,
2259 unsigned int len)
2260 {
2261 struct compat_ebt_replace hlp;
2262
2263 if (copy_from_user(&hlp, user, sizeof(hlp)))
2264 return -EFAULT;
2265
2266 /* try real handler in case userland supplied needed padding */
2267 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
2268 return update_counters(net, user, len);
2269
2270 return do_update_counters(net, hlp.name, compat_ptr(hlp.counters),
2271 hlp.num_counters, user, len);
2272 }
2273
2274 static int compat_do_ebt_set_ctl(struct sock *sk,
2275 int cmd, void __user *user, unsigned int len)
2276 {
2277 int ret;
2278
2279 if (!capable(CAP_NET_ADMIN))
2280 return -EPERM;
2281
2282 switch (cmd) {
2283 case EBT_SO_SET_ENTRIES:
2284 ret = compat_do_replace(sock_net(sk), user, len);
2285 break;
2286 case EBT_SO_SET_COUNTERS:
2287 ret = compat_update_counters(sock_net(sk), user, len);
2288 break;
2289 default:
2290 ret = -EINVAL;
2291 }
2292 return ret;
2293 }
2294
2295 static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
2296 void __user *user, int *len)
2297 {
2298 int ret;
2299 struct compat_ebt_replace tmp;
2300 struct ebt_table *t;
2301
2302 if (!capable(CAP_NET_ADMIN))
2303 return -EPERM;
2304
2305 /* try real handler in case userland supplied needed padding */
2306 if ((cmd == EBT_SO_GET_INFO ||
2307 cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp))
2308 return do_ebt_get_ctl(sk, cmd, user, len);
2309
2310 if (copy_from_user(&tmp, user, sizeof(tmp)))
2311 return -EFAULT;
2312
2313 t = find_table_lock(sock_net(sk), tmp.name, &ret, &ebt_mutex);
2314 if (!t)
2315 return ret;
2316
2317 xt_compat_lock(NFPROTO_BRIDGE);
2318 switch (cmd) {
2319 case EBT_SO_GET_INFO:
2320 tmp.nentries = t->private->nentries;
2321 ret = compat_table_info(t->private, &tmp);
2322 if (ret)
2323 goto out;
2324 tmp.valid_hooks = t->valid_hooks;
2325
2326 if (copy_to_user(user, &tmp, *len) != 0) {
2327 ret = -EFAULT;
2328 break;
2329 }
2330 ret = 0;
2331 break;
2332 case EBT_SO_GET_INIT_INFO:
2333 tmp.nentries = t->table->nentries;
2334 tmp.entries_size = t->table->entries_size;
2335 tmp.valid_hooks = t->table->valid_hooks;
2336
2337 if (copy_to_user(user, &tmp, *len) != 0) {
2338 ret = -EFAULT;
2339 break;
2340 }
2341 ret = 0;
2342 break;
2343 case EBT_SO_GET_ENTRIES:
2344 case EBT_SO_GET_INIT_ENTRIES:
2345 /*
2346 * try real handler first in case of userland-side padding.
2347 * in case we are dealing with an 'ordinary' 32 bit binary
2348 * without 64bit compatibility padding, this will fail right
2349 * after copy_from_user when the *len argument is validated.
2350 *
2351 * the compat_ variant needs to do one pass over the kernel
2352 * data set to adjust for size differences before it the check.
2353 */
2354 if (copy_everything_to_user(t, user, len, cmd) == 0)
2355 ret = 0;
2356 else
2357 ret = compat_copy_everything_to_user(t, user, len, cmd);
2358 break;
2359 default:
2360 ret = -EINVAL;
2361 }
2362 out:
2363 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2364 xt_compat_unlock(NFPROTO_BRIDGE);
2365 mutex_unlock(&ebt_mutex);
2366 return ret;
2367 }
2368 #endif
2369
2370 static struct nf_sockopt_ops ebt_sockopts =
2371 {
2372 .pf = PF_INET,
2373 .set_optmin = EBT_BASE_CTL,
2374 .set_optmax = EBT_SO_SET_MAX + 1,
2375 .set = do_ebt_set_ctl,
2376 #ifdef CONFIG_COMPAT
2377 .compat_set = compat_do_ebt_set_ctl,
2378 #endif
2379 .get_optmin = EBT_BASE_CTL,
2380 .get_optmax = EBT_SO_GET_MAX + 1,
2381 .get = do_ebt_get_ctl,
2382 #ifdef CONFIG_COMPAT
2383 .compat_get = compat_do_ebt_get_ctl,
2384 #endif
2385 .owner = THIS_MODULE,
2386 };
2387
2388 static int __init ebtables_init(void)
2389 {
2390 int ret;
2391
2392 ret = xt_register_target(&ebt_standard_target);
2393 if (ret < 0)
2394 return ret;
2395 ret = nf_register_sockopt(&ebt_sockopts);
2396 if (ret < 0) {
2397 xt_unregister_target(&ebt_standard_target);
2398 return ret;
2399 }
2400
2401 printk(KERN_INFO "Ebtables v2.0 registered\n");
2402 return 0;
2403 }
2404
2405 static void __exit ebtables_fini(void)
2406 {
2407 nf_unregister_sockopt(&ebt_sockopts);
2408 xt_unregister_target(&ebt_standard_target);
2409 printk(KERN_INFO "Ebtables v2.0 unregistered\n");
2410 }
2411
2412 EXPORT_SYMBOL(ebt_register_table);
2413 EXPORT_SYMBOL(ebt_unregister_table);
2414 EXPORT_SYMBOL(ebt_do_table);
2415 module_init(ebtables_init);
2416 module_exit(ebtables_fini);
2417 MODULE_LICENSE("GPL");
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