5 * Bart De Schuymer <bdschuym@pandora.be>
7 * ebtables.c,v 2.0, July, 2002
9 * This code is strongly inspired by the iptables code which is
10 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
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.
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>
31 /* needed for logical [in,out]-dev filtering */
32 #include "../br_private.h"
34 #define BUGPRINT(format, args...) printk("kernel msg: ebtables bug: please "\
35 "report to author: "format, ## args)
36 /* #define BUGPRINT(format, args...) */
38 /* Each cpu has its own set of counters, so there is no need for write_lock in
40 * For reading or updating the counters, the user context needs to
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))
52 static DEFINE_MUTEX(ebt_mutex);
55 static void ebt_standard_compat_from_user(void *dst, const void *src)
57 int v = *(compat_int_t *)src;
60 v += xt_compat_calc_jump(NFPROTO_BRIDGE, v);
61 memcpy(dst, &v, sizeof(v));
64 static int ebt_standard_compat_to_user(void __user *dst, const void *src)
66 compat_int_t cv = *(int *)src;
69 cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv);
70 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
75 static struct xt_target ebt_standard_target = {
78 .family = NFPROTO_BRIDGE,
79 .targetsize = sizeof(int),
81 .compatsize = sizeof(compat_int_t),
82 .compat_from_user = ebt_standard_compat_from_user,
83 .compat_to_user = ebt_standard_compat_to_user,
88 ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb,
89 struct xt_action_param *par)
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 */
99 ebt_do_match(struct ebt_entry_match *m, const struct sk_buff *skb,
100 struct xt_action_param *par)
102 par->match = m->u.match;
103 par->matchinfo = m->data;
104 return m->u.match->match(skb, par) ? EBT_MATCH : EBT_NOMATCH;
108 ebt_dev_check(const char *entry, const struct net_device *device)
117 devname = device->name;
118 /* 1 is the wildcard token */
119 while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i])
121 return devname[i] != entry[i] && entry[i] != 1;
124 /* process standard matches */
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)
129 const struct ethhdr *h = eth_hdr(skb);
130 const struct net_bridge_port *p;
133 if (skb_vlan_tag_present(skb))
134 ethproto = htons(ETH_P_8021Q);
136 ethproto = h->h_proto;
138 if (e->bitmask & EBT_802_3) {
139 if (NF_INVF(e, EBT_IPROTO, eth_proto_is_802_3(ethproto)))
141 } else if (!(e->bitmask & EBT_NOPROTO) &&
142 NF_INVF(e, EBT_IPROTO, e->ethproto != ethproto))
145 if (NF_INVF(e, EBT_IIN, ebt_dev_check(e->in, in)))
147 if (NF_INVF(e, EBT_IOUT, ebt_dev_check(e->out, out)))
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)))
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)))
159 if (e->bitmask & EBT_SOURCEMAC) {
160 if (NF_INVF(e, EBT_ISOURCE,
161 !ether_addr_equal_masked(h->h_source, e->sourcemac,
165 if (e->bitmask & EBT_DESTMAC) {
166 if (NF_INVF(e, EBT_IDEST,
167 !ether_addr_equal_masked(h->h_dest, e->destmac,
175 struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry)
177 return (void *)entry + entry->next_offset;
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)
185 unsigned int hook = state->hook;
187 struct ebt_entry *point;
188 struct ebt_counter *counter_base, *cb_base;
189 const struct ebt_entry_target *t;
191 struct ebt_chainstack *cs;
192 struct ebt_entries *chaininfo;
194 const struct ebt_table_info *private;
195 struct xt_action_param acpar;
198 acpar.hotdrop = false;
200 read_lock_bh(&table->lock);
201 private = table->private;
202 cb_base = COUNTER_BASE(private->counters, private->nentries,
204 if (private->chainstack)
205 cs = private->chainstack[smp_processor_id()];
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;
215 while (i < nentries) {
216 if (ebt_basic_match(point, skb, state->in, state->out))
219 if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0)
222 read_unlock_bh(&table->lock);
226 ADD_COUNTER(*(counter_base + i), 1, skb->len);
228 /* these should only watch: not modify, nor tell us
229 * what to do with the packet
231 EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar);
233 t = (struct ebt_entry_target *)
234 (((char *)point) + point->target_offset);
235 /* standard target */
236 if (!t->u.target->target)
237 verdict = ((struct ebt_standard_target *)t)->verdict;
239 acpar.target = t->u.target;
240 acpar.targinfo = t->data;
241 verdict = t->u.target->target(skb, &acpar);
243 if (verdict == EBT_ACCEPT) {
244 read_unlock_bh(&table->lock);
247 if (verdict == EBT_DROP) {
248 read_unlock_bh(&table->lock);
251 if (verdict == EBT_RETURN) {
253 if (WARN(sp == 0, "RETURN on base chain")) {
254 /* act like this is EBT_CONTINUE */
259 /* put all the local variables right */
261 chaininfo = cs[sp].chaininfo;
262 nentries = chaininfo->nentries;
264 counter_base = cb_base +
265 chaininfo->counter_offset;
268 if (verdict == EBT_CONTINUE)
271 if (WARN(verdict < 0, "bogus standard verdict\n")) {
272 read_unlock_bh(&table->lock);
278 cs[sp].chaininfo = chaininfo;
279 cs[sp].e = ebt_next_entry(point);
281 chaininfo = (struct ebt_entries *) (base + verdict);
283 if (WARN(chaininfo->distinguisher, "jump to non-chain\n")) {
284 read_unlock_bh(&table->lock);
288 nentries = chaininfo->nentries;
289 point = (struct ebt_entry *)chaininfo->data;
290 counter_base = cb_base + chaininfo->counter_offset;
294 point = ebt_next_entry(point);
298 /* I actually like this :) */
299 if (chaininfo->policy == EBT_RETURN)
301 if (chaininfo->policy == EBT_ACCEPT) {
302 read_unlock_bh(&table->lock);
305 read_unlock_bh(&table->lock);
309 /* If it succeeds, returns element and locks mutex */
311 find_inlist_lock_noload(struct list_head *head, const char *name, int *error,
315 struct list_head list;
316 char name[EBT_FUNCTION_MAXNAMELEN];
320 list_for_each_entry(e, head, list) {
321 if (strcmp(e->name, name) == 0)
330 find_inlist_lock(struct list_head *head, const char *name, const char *prefix,
331 int *error, struct mutex *mutex)
333 return try_then_request_module(
334 find_inlist_lock_noload(head, name, error, mutex),
335 "%s%s", prefix, name);
338 static inline struct ebt_table *
339 find_table_lock(struct net *net, const char *name, int *error,
342 return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name,
343 "ebtable_", error, mutex);
347 ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
350 const struct ebt_entry *e = par->entryinfo;
351 struct xt_match *match;
352 size_t left = ((char *)e + e->watchers_offset) - (char *)m;
355 if (left < sizeof(struct ebt_entry_match) ||
356 left - sizeof(struct ebt_entry_match) < m->match_size)
359 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision);
360 if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) {
362 module_put(match->me);
363 request_module("ebt_%s", m->u.name);
364 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision);
367 return PTR_ERR(match);
371 par->matchinfo = m->data;
372 ret = xt_check_match(par, m->match_size,
373 e->ethproto, e->invflags & EBT_IPROTO);
375 module_put(match->me);
384 ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
387 const struct ebt_entry *e = par->entryinfo;
388 struct xt_target *watcher;
389 size_t left = ((char *)e + e->target_offset) - (char *)w;
392 if (left < sizeof(struct ebt_entry_watcher) ||
393 left - sizeof(struct ebt_entry_watcher) < w->watcher_size)
396 watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0);
398 return PTR_ERR(watcher);
399 w->u.watcher = watcher;
401 par->target = watcher;
402 par->targinfo = w->data;
403 ret = xt_check_target(par, w->watcher_size,
404 e->ethproto, e->invflags & EBT_IPROTO);
406 module_put(watcher->me);
414 static int ebt_verify_pointers(const struct ebt_replace *repl,
415 struct ebt_table_info *newinfo)
417 unsigned int limit = repl->entries_size;
418 unsigned int valid_hooks = repl->valid_hooks;
419 unsigned int offset = 0;
422 for (i = 0; i < NF_BR_NUMHOOKS; i++)
423 newinfo->hook_entry[i] = NULL;
425 newinfo->entries_size = repl->entries_size;
426 newinfo->nentries = repl->nentries;
428 while (offset < limit) {
429 size_t left = limit - offset;
430 struct ebt_entry *e = (void *)newinfo->entries + offset;
432 if (left < sizeof(unsigned int))
435 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
436 if ((valid_hooks & (1 << i)) == 0)
438 if ((char __user *)repl->hook_entry[i] ==
439 repl->entries + offset)
443 if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
444 if (e->bitmask != 0) {
445 /* we make userspace set this right,
446 * so there is no misunderstanding
448 BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set "
449 "in distinguisher\n");
452 if (i != NF_BR_NUMHOOKS)
453 newinfo->hook_entry[i] = (struct ebt_entries *)e;
454 if (left < sizeof(struct ebt_entries))
456 offset += sizeof(struct ebt_entries);
458 if (left < sizeof(struct ebt_entry))
460 if (left < e->next_offset)
462 if (e->next_offset < sizeof(struct ebt_entry))
464 offset += e->next_offset;
467 if (offset != limit) {
468 BUGPRINT("entries_size too small\n");
472 /* check if all valid hooks have a chain */
473 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
474 if (!newinfo->hook_entry[i] &&
475 (valid_hooks & (1 << i))) {
476 BUGPRINT("Valid hook without chain\n");
483 /* this one is very careful, as it is the first function
484 * to parse the userspace data
487 ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
488 const struct ebt_table_info *newinfo,
489 unsigned int *n, unsigned int *cnt,
490 unsigned int *totalcnt, unsigned int *udc_cnt)
494 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
495 if ((void *)e == (void *)newinfo->hook_entry[i])
498 /* beginning of a new chain
499 * if i == NF_BR_NUMHOOKS it must be a user defined chain
501 if (i != NF_BR_NUMHOOKS || !e->bitmask) {
502 /* this checks if the previous chain has as many entries
506 BUGPRINT("nentries does not equal the nr of entries "
510 if (((struct ebt_entries *)e)->policy != EBT_DROP &&
511 ((struct ebt_entries *)e)->policy != EBT_ACCEPT) {
512 /* only RETURN from udc */
513 if (i != NF_BR_NUMHOOKS ||
514 ((struct ebt_entries *)e)->policy != EBT_RETURN) {
515 BUGPRINT("bad policy\n");
519 if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */
521 if (((struct ebt_entries *)e)->counter_offset != *totalcnt) {
522 BUGPRINT("counter_offset != totalcnt");
525 *n = ((struct ebt_entries *)e)->nentries;
529 /* a plain old entry, heh */
530 if (sizeof(struct ebt_entry) > e->watchers_offset ||
531 e->watchers_offset > e->target_offset ||
532 e->target_offset >= e->next_offset) {
533 BUGPRINT("entry offsets not in right order\n");
536 /* this is not checked anywhere else */
537 if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target)) {
538 BUGPRINT("target size too small\n");
546 struct ebt_cl_stack {
547 struct ebt_chainstack cs;
549 unsigned int hookmask;
552 /* We need these positions to check that the jumps to a different part of the
553 * entries is a jump to the beginning of a new chain.
556 ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo,
557 unsigned int *n, struct ebt_cl_stack *udc)
561 /* we're only interested in chain starts */
564 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
565 if (newinfo->hook_entry[i] == (struct ebt_entries *)e)
568 /* only care about udc */
569 if (i != NF_BR_NUMHOOKS)
572 udc[*n].cs.chaininfo = (struct ebt_entries *)e;
573 /* these initialisations are depended on later in check_chainloops() */
575 udc[*n].hookmask = 0;
582 ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i)
584 struct xt_mtdtor_param par;
586 if (i && (*i)-- == 0)
590 par.match = m->u.match;
591 par.matchinfo = m->data;
592 par.family = NFPROTO_BRIDGE;
593 if (par.match->destroy != NULL)
594 par.match->destroy(&par);
595 module_put(par.match->me);
600 ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i)
602 struct xt_tgdtor_param par;
604 if (i && (*i)-- == 0)
608 par.target = w->u.watcher;
609 par.targinfo = w->data;
610 par.family = NFPROTO_BRIDGE;
611 if (par.target->destroy != NULL)
612 par.target->destroy(&par);
613 module_put(par.target->me);
618 ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
620 struct xt_tgdtor_param par;
621 struct ebt_entry_target *t;
626 if (cnt && (*cnt)-- == 0)
628 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL);
629 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL);
630 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
633 par.target = t->u.target;
634 par.targinfo = t->data;
635 par.family = NFPROTO_BRIDGE;
636 if (par.target->destroy != NULL)
637 par.target->destroy(&par);
638 module_put(par.target->me);
643 ebt_check_entry(struct ebt_entry *e, struct net *net,
644 const struct ebt_table_info *newinfo,
645 const char *name, unsigned int *cnt,
646 struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
648 struct ebt_entry_target *t;
649 struct xt_target *target;
650 unsigned int i, j, hook = 0, hookmask = 0;
653 struct xt_mtchk_param mtpar;
654 struct xt_tgchk_param tgpar;
656 /* don't mess with the struct ebt_entries */
660 if (e->bitmask & ~EBT_F_MASK) {
661 BUGPRINT("Unknown flag for bitmask\n");
664 if (e->invflags & ~EBT_INV_MASK) {
665 BUGPRINT("Unknown flag for inv bitmask\n");
668 if ((e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3)) {
669 BUGPRINT("NOPROTO & 802_3 not allowed\n");
672 /* what hook do we belong to? */
673 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
674 if (!newinfo->hook_entry[i])
676 if ((char *)newinfo->hook_entry[i] < (char *)e)
681 /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on
684 if (i < NF_BR_NUMHOOKS)
685 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
687 for (i = 0; i < udc_cnt; i++)
688 if ((char *)(cl_s[i].cs.chaininfo) > (char *)e)
691 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
693 hookmask = cl_s[i - 1].hookmask;
697 mtpar.net = tgpar.net = net;
698 mtpar.table = tgpar.table = name;
699 mtpar.entryinfo = tgpar.entryinfo = e;
700 mtpar.hook_mask = tgpar.hook_mask = hookmask;
701 mtpar.family = tgpar.family = NFPROTO_BRIDGE;
702 ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i);
704 goto cleanup_matches;
706 ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j);
708 goto cleanup_watchers;
709 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
710 gap = e->next_offset - e->target_offset;
712 target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0);
713 if (IS_ERR(target)) {
714 ret = PTR_ERR(target);
715 goto cleanup_watchers;
718 t->u.target = target;
719 if (t->u.target == &ebt_standard_target) {
720 if (gap < sizeof(struct ebt_standard_target)) {
721 BUGPRINT("Standard target size too big\n");
723 goto cleanup_watchers;
725 if (((struct ebt_standard_target *)t)->verdict <
726 -NUM_STANDARD_TARGETS) {
727 BUGPRINT("Invalid standard target\n");
729 goto cleanup_watchers;
731 } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) {
732 module_put(t->u.target->me);
734 goto cleanup_watchers;
737 tgpar.target = target;
738 tgpar.targinfo = t->data;
739 ret = xt_check_target(&tgpar, t->target_size,
740 e->ethproto, e->invflags & EBT_IPROTO);
742 module_put(target->me);
743 goto cleanup_watchers;
748 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j);
750 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i);
754 /* checks for loops and sets the hook mask for udc
755 * the hook mask for udc tells us from which base chains the udc can be
756 * accessed. This mask is a parameter to the check() functions of the extensions
758 static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
759 unsigned int udc_cnt, unsigned int hooknr, char *base)
761 int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
762 const struct ebt_entry *e = (struct ebt_entry *)chain->data;
763 const struct ebt_entry_target *t;
765 while (pos < nentries || chain_nr != -1) {
766 /* end of udc, go back one 'recursion' step */
767 if (pos == nentries) {
768 /* put back values of the time when this chain was called */
769 e = cl_s[chain_nr].cs.e;
770 if (cl_s[chain_nr].from != -1)
772 cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries;
774 nentries = chain->nentries;
775 pos = cl_s[chain_nr].cs.n;
776 /* make sure we won't see a loop that isn't one */
777 cl_s[chain_nr].cs.n = 0;
778 chain_nr = cl_s[chain_nr].from;
782 t = (struct ebt_entry_target *)
783 (((char *)e) + e->target_offset);
784 if (strcmp(t->u.name, EBT_STANDARD_TARGET))
786 if (e->target_offset + sizeof(struct ebt_standard_target) >
788 BUGPRINT("Standard target size too big\n");
791 verdict = ((struct ebt_standard_target *)t)->verdict;
792 if (verdict >= 0) { /* jump to another chain */
793 struct ebt_entries *hlp2 =
794 (struct ebt_entries *)(base + verdict);
795 for (i = 0; i < udc_cnt; i++)
796 if (hlp2 == cl_s[i].cs.chaininfo)
798 /* bad destination or loop */
800 BUGPRINT("bad destination\n");
807 if (cl_s[i].hookmask & (1 << hooknr))
809 /* this can't be 0, so the loop test is correct */
810 cl_s[i].cs.n = pos + 1;
812 cl_s[i].cs.e = ebt_next_entry(e);
813 e = (struct ebt_entry *)(hlp2->data);
814 nentries = hlp2->nentries;
815 cl_s[i].from = chain_nr;
817 /* this udc is accessible from the base chain for hooknr */
818 cl_s[i].hookmask |= (1 << hooknr);
822 e = ebt_next_entry(e);
828 /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
829 static int translate_table(struct net *net, const char *name,
830 struct ebt_table_info *newinfo)
832 unsigned int i, j, k, udc_cnt;
834 struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */
837 while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i])
839 if (i == NF_BR_NUMHOOKS) {
840 BUGPRINT("No valid hooks specified\n");
843 if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) {
844 BUGPRINT("Chains don't start at beginning\n");
847 /* make sure chains are ordered after each other in same order
848 * as their corresponding hooks
850 for (j = i + 1; j < NF_BR_NUMHOOKS; j++) {
851 if (!newinfo->hook_entry[j])
853 if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) {
854 BUGPRINT("Hook order must be followed\n");
860 /* do some early checkings and initialize some things */
861 i = 0; /* holds the expected nr. of entries for the chain */
862 j = 0; /* holds the up to now counted entries for the chain */
863 k = 0; /* holds the total nr. of entries, should equal
864 * newinfo->nentries afterwards
866 udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */
867 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
868 ebt_check_entry_size_and_hooks, newinfo,
869 &i, &j, &k, &udc_cnt);
875 BUGPRINT("nentries does not equal the nr of entries in the "
879 if (k != newinfo->nentries) {
880 BUGPRINT("Total nentries is wrong\n");
884 /* get the location of the udc, put them in an array
885 * while we're at it, allocate the chainstack
888 /* this will get free'd in do_replace()/ebt_register_table()
891 newinfo->chainstack =
892 vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack)));
893 if (!newinfo->chainstack)
895 for_each_possible_cpu(i) {
896 newinfo->chainstack[i] =
897 vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0])));
898 if (!newinfo->chainstack[i]) {
900 vfree(newinfo->chainstack[--i]);
901 vfree(newinfo->chainstack);
902 newinfo->chainstack = NULL;
907 cl_s = vmalloc(udc_cnt * sizeof(*cl_s));
910 i = 0; /* the i'th udc */
911 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
912 ebt_get_udc_positions, newinfo, &i, cl_s);
915 BUGPRINT("i != udc_cnt\n");
921 /* Check for loops */
922 for (i = 0; i < NF_BR_NUMHOOKS; i++)
923 if (newinfo->hook_entry[i])
924 if (check_chainloops(newinfo->hook_entry[i],
925 cl_s, udc_cnt, i, newinfo->entries)) {
930 /* we now know the following (along with E=mc²):
931 * - the nr of entries in each chain is right
932 * - the size of the allocated space is right
933 * - all valid hooks have a corresponding chain
934 * - there are no loops
935 * - wrong data can still be on the level of a single entry
936 * - could be there are jumps to places that are not the
937 * beginning of a chain. This can only occur in chains that
938 * are not accessible from any base chains, so we don't care.
941 /* used to know what we need to clean up if something goes wrong */
943 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
944 ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt);
946 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
947 ebt_cleanup_entry, net, &i);
953 /* called under write_lock */
954 static void get_counters(const struct ebt_counter *oldcounters,
955 struct ebt_counter *counters, unsigned int nentries)
958 struct ebt_counter *counter_base;
960 /* counters of cpu 0 */
961 memcpy(counters, oldcounters,
962 sizeof(struct ebt_counter) * nentries);
964 /* add other counters to those of cpu 0 */
965 for_each_possible_cpu(cpu) {
968 counter_base = COUNTER_BASE(oldcounters, nentries, cpu);
969 for (i = 0; i < nentries; i++)
970 ADD_COUNTER(counters[i], counter_base[i].pcnt,
971 counter_base[i].bcnt);
975 static int do_replace_finish(struct net *net, struct ebt_replace *repl,
976 struct ebt_table_info *newinfo)
979 struct ebt_counter *counterstmp = NULL;
980 /* used to be able to unlock earlier */
981 struct ebt_table_info *table;
984 /* the user wants counters back
985 * the check on the size is done later, when we have the lock
987 if (repl->num_counters) {
988 unsigned long size = repl->num_counters * sizeof(*counterstmp);
989 counterstmp = vmalloc(size);
994 newinfo->chainstack = NULL;
995 ret = ebt_verify_pointers(repl, newinfo);
997 goto free_counterstmp;
999 ret = translate_table(net, repl->name, newinfo);
1002 goto free_counterstmp;
1004 t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
1010 /* the table doesn't like it */
1011 if (t->check && (ret = t->check(newinfo, repl->valid_hooks)))
1014 if (repl->num_counters && repl->num_counters != t->private->nentries) {
1015 BUGPRINT("Wrong nr. of counters requested\n");
1020 /* we have the mutex lock, so no danger in reading this pointer */
1022 /* make sure the table can only be rmmod'ed if it contains no rules */
1023 if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) {
1026 } else if (table->nentries && !newinfo->nentries)
1028 /* we need an atomic snapshot of the counters */
1029 write_lock_bh(&t->lock);
1030 if (repl->num_counters)
1031 get_counters(t->private->counters, counterstmp,
1032 t->private->nentries);
1034 t->private = newinfo;
1035 write_unlock_bh(&t->lock);
1036 mutex_unlock(&ebt_mutex);
1037 /* so, a user can change the chains while having messed up her counter
1038 * allocation. Only reason why this is done is because this way the lock
1039 * is held only once, while this doesn't bring the kernel into a
1042 if (repl->num_counters &&
1043 copy_to_user(repl->counters, counterstmp,
1044 repl->num_counters * sizeof(struct ebt_counter))) {
1045 /* Silent error, can't fail, new table is already in place */
1046 net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n");
1049 /* decrease module count and free resources */
1050 EBT_ENTRY_ITERATE(table->entries, table->entries_size,
1051 ebt_cleanup_entry, net, NULL);
1053 vfree(table->entries);
1054 if (table->chainstack) {
1055 for_each_possible_cpu(i)
1056 vfree(table->chainstack[i]);
1057 vfree(table->chainstack);
1064 if (audit_enabled) {
1065 audit_log(current->audit_context, GFP_KERNEL,
1066 AUDIT_NETFILTER_CFG,
1067 "table=%s family=%u entries=%u",
1068 repl->name, AF_BRIDGE, repl->nentries);
1074 mutex_unlock(&ebt_mutex);
1076 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
1077 ebt_cleanup_entry, net, NULL);
1080 /* can be initialized in translate_table() */
1081 if (newinfo->chainstack) {
1082 for_each_possible_cpu(i)
1083 vfree(newinfo->chainstack[i]);
1084 vfree(newinfo->chainstack);
1089 /* replace the table */
1090 static int do_replace(struct net *net, const void __user *user,
1093 int ret, countersize;
1094 struct ebt_table_info *newinfo;
1095 struct ebt_replace tmp;
1097 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1100 if (len != sizeof(tmp) + tmp.entries_size) {
1101 BUGPRINT("Wrong len argument\n");
1105 if (tmp.entries_size == 0) {
1106 BUGPRINT("Entries_size never zero\n");
1109 /* overflow check */
1110 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
1111 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
1113 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
1116 tmp.name[sizeof(tmp.name) - 1] = 0;
1118 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
1119 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1124 memset(newinfo->counters, 0, countersize);
1126 newinfo->entries = vmalloc(tmp.entries_size);
1127 if (!newinfo->entries) {
1132 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
1133 BUGPRINT("Couldn't copy entries from userspace\n");
1138 ret = do_replace_finish(net, &tmp, newinfo);
1142 vfree(newinfo->entries);
1148 static void __ebt_unregister_table(struct net *net, struct ebt_table *table)
1152 mutex_lock(&ebt_mutex);
1153 list_del(&table->list);
1154 mutex_unlock(&ebt_mutex);
1155 EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
1156 ebt_cleanup_entry, net, NULL);
1157 if (table->private->nentries)
1158 module_put(table->me);
1159 vfree(table->private->entries);
1160 if (table->private->chainstack) {
1161 for_each_possible_cpu(i)
1162 vfree(table->private->chainstack[i]);
1163 vfree(table->private->chainstack);
1165 vfree(table->private);
1169 int ebt_register_table(struct net *net, const struct ebt_table *input_table,
1170 const struct nf_hook_ops *ops, struct ebt_table **res)
1172 struct ebt_table_info *newinfo;
1173 struct ebt_table *t, *table;
1174 struct ebt_replace_kernel *repl;
1175 int ret, i, countersize;
1178 if (input_table == NULL || (repl = input_table->table) == NULL ||
1179 repl->entries == NULL || repl->entries_size == 0 ||
1180 repl->counters != NULL || input_table->private != NULL) {
1181 BUGPRINT("Bad table data for ebt_register_table!!!\n");
1185 /* Don't add one table to multiple lists. */
1186 table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL);
1192 countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
1193 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1198 p = vmalloc(repl->entries_size);
1202 memcpy(p, repl->entries, repl->entries_size);
1203 newinfo->entries = p;
1205 newinfo->entries_size = repl->entries_size;
1206 newinfo->nentries = repl->nentries;
1209 memset(newinfo->counters, 0, countersize);
1211 /* fill in newinfo and parse the entries */
1212 newinfo->chainstack = NULL;
1213 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1214 if ((repl->valid_hooks & (1 << i)) == 0)
1215 newinfo->hook_entry[i] = NULL;
1217 newinfo->hook_entry[i] = p +
1218 ((char *)repl->hook_entry[i] - repl->entries);
1220 ret = translate_table(net, repl->name, newinfo);
1222 BUGPRINT("Translate_table failed\n");
1223 goto free_chainstack;
1226 if (table->check && table->check(newinfo, table->valid_hooks)) {
1227 BUGPRINT("The table doesn't like its own initial data, lol\n");
1229 goto free_chainstack;
1232 table->private = newinfo;
1233 rwlock_init(&table->lock);
1234 mutex_lock(&ebt_mutex);
1235 list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
1236 if (strcmp(t->name, table->name) == 0) {
1238 BUGPRINT("Table name already exists\n");
1243 /* Hold a reference count if the chains aren't empty */
1244 if (newinfo->nentries && !try_module_get(table->me)) {
1248 list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
1249 mutex_unlock(&ebt_mutex);
1251 WRITE_ONCE(*res, table);
1256 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
1258 __ebt_unregister_table(net, table);
1264 mutex_unlock(&ebt_mutex);
1266 if (newinfo->chainstack) {
1267 for_each_possible_cpu(i)
1268 vfree(newinfo->chainstack[i]);
1269 vfree(newinfo->chainstack);
1271 vfree(newinfo->entries);
1280 void ebt_unregister_table(struct net *net, struct ebt_table *table,
1281 const struct nf_hook_ops *ops)
1284 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
1285 __ebt_unregister_table(net, table);
1288 /* userspace just supplied us with counters */
1289 static int do_update_counters(struct net *net, const char *name,
1290 struct ebt_counter __user *counters,
1291 unsigned int num_counters,
1292 const void __user *user, unsigned int len)
1295 struct ebt_counter *tmp;
1296 struct ebt_table *t;
1298 if (num_counters == 0)
1301 tmp = vmalloc(num_counters * sizeof(*tmp));
1305 t = find_table_lock(net, name, &ret, &ebt_mutex);
1309 if (num_counters != t->private->nentries) {
1310 BUGPRINT("Wrong nr of counters\n");
1315 if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) {
1320 /* we want an atomic add of the counters */
1321 write_lock_bh(&t->lock);
1323 /* we add to the counters of the first cpu */
1324 for (i = 0; i < num_counters; i++)
1325 ADD_COUNTER(t->private->counters[i], tmp[i].pcnt, tmp[i].bcnt);
1327 write_unlock_bh(&t->lock);
1330 mutex_unlock(&ebt_mutex);
1336 static int update_counters(struct net *net, const void __user *user,
1339 struct ebt_replace hlp;
1341 if (copy_from_user(&hlp, user, sizeof(hlp)))
1344 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
1347 return do_update_counters(net, hlp.name, hlp.counters,
1348 hlp.num_counters, user, len);
1351 static inline int ebt_obj_to_user(char __user *um, const char *_name,
1352 const char *data, int entrysize,
1353 int usersize, int datasize, u8 revision)
1355 char name[EBT_EXTENSION_MAXNAMELEN] = {0};
1357 /* ebtables expects 31 bytes long names but xt_match names are 29 bytes
1358 * long. Copy 29 bytes and fill remaining bytes with zeroes.
1360 strlcpy(name, _name, sizeof(name));
1361 if (copy_to_user(um, name, EBT_EXTENSION_MAXNAMELEN) ||
1362 put_user(revision, (u8 __user *)(um + EBT_EXTENSION_MAXNAMELEN)) ||
1363 put_user(datasize, (int __user *)(um + EBT_EXTENSION_MAXNAMELEN + 1)) ||
1364 xt_data_to_user(um + entrysize, data, usersize, datasize,
1365 XT_ALIGN(datasize)))
1371 static inline int ebt_match_to_user(const struct ebt_entry_match *m,
1372 const char *base, char __user *ubase)
1374 return ebt_obj_to_user(ubase + ((char *)m - base),
1375 m->u.match->name, m->data, sizeof(*m),
1376 m->u.match->usersize, m->match_size,
1377 m->u.match->revision);
1380 static inline int ebt_watcher_to_user(const struct ebt_entry_watcher *w,
1381 const char *base, char __user *ubase)
1383 return ebt_obj_to_user(ubase + ((char *)w - base),
1384 w->u.watcher->name, w->data, sizeof(*w),
1385 w->u.watcher->usersize, w->watcher_size,
1386 w->u.watcher->revision);
1389 static inline int ebt_entry_to_user(struct ebt_entry *e, const char *base,
1394 const struct ebt_entry_target *t;
1396 if (e->bitmask == 0) {
1397 /* special case !EBT_ENTRY_OR_ENTRIES */
1398 if (copy_to_user(ubase + ((char *)e - base), e,
1399 sizeof(struct ebt_entries)))
1404 if (copy_to_user(ubase + ((char *)e - base), e, sizeof(*e)))
1407 hlp = ubase + (((char *)e + e->target_offset) - base);
1408 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
1410 ret = EBT_MATCH_ITERATE(e, ebt_match_to_user, base, ubase);
1413 ret = EBT_WATCHER_ITERATE(e, ebt_watcher_to_user, base, ubase);
1416 ret = ebt_obj_to_user(hlp, t->u.target->name, t->data, sizeof(*t),
1417 t->u.target->usersize, t->target_size,
1418 t->u.target->revision);
1425 static int copy_counters_to_user(struct ebt_table *t,
1426 const struct ebt_counter *oldcounters,
1427 void __user *user, unsigned int num_counters,
1428 unsigned int nentries)
1430 struct ebt_counter *counterstmp;
1433 /* userspace might not need the counters */
1434 if (num_counters == 0)
1437 if (num_counters != nentries) {
1438 BUGPRINT("Num_counters wrong\n");
1442 counterstmp = vmalloc(nentries * sizeof(*counterstmp));
1446 write_lock_bh(&t->lock);
1447 get_counters(oldcounters, counterstmp, nentries);
1448 write_unlock_bh(&t->lock);
1450 if (copy_to_user(user, counterstmp,
1451 nentries * sizeof(struct ebt_counter)))
1457 /* called with ebt_mutex locked */
1458 static int copy_everything_to_user(struct ebt_table *t, void __user *user,
1459 const int *len, int cmd)
1461 struct ebt_replace tmp;
1462 const struct ebt_counter *oldcounters;
1463 unsigned int entries_size, nentries;
1467 if (cmd == EBT_SO_GET_ENTRIES) {
1468 entries_size = t->private->entries_size;
1469 nentries = t->private->nentries;
1470 entries = t->private->entries;
1471 oldcounters = t->private->counters;
1473 entries_size = t->table->entries_size;
1474 nentries = t->table->nentries;
1475 entries = t->table->entries;
1476 oldcounters = t->table->counters;
1479 if (copy_from_user(&tmp, user, sizeof(tmp)))
1482 if (*len != sizeof(struct ebt_replace) + entries_size +
1483 (tmp.num_counters ? nentries * sizeof(struct ebt_counter) : 0))
1486 if (tmp.nentries != nentries) {
1487 BUGPRINT("Nentries wrong\n");
1491 if (tmp.entries_size != entries_size) {
1492 BUGPRINT("Wrong size\n");
1496 ret = copy_counters_to_user(t, oldcounters, tmp.counters,
1497 tmp.num_counters, nentries);
1501 /* set the match/watcher/target names right */
1502 return EBT_ENTRY_ITERATE(entries, entries_size,
1503 ebt_entry_to_user, entries, tmp.entries);
1506 static int do_ebt_set_ctl(struct sock *sk,
1507 int cmd, void __user *user, unsigned int len)
1510 struct net *net = sock_net(sk);
1512 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1516 case EBT_SO_SET_ENTRIES:
1517 ret = do_replace(net, user, len);
1519 case EBT_SO_SET_COUNTERS:
1520 ret = update_counters(net, user, len);
1528 static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1531 struct ebt_replace tmp;
1532 struct ebt_table *t;
1533 struct net *net = sock_net(sk);
1535 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1538 if (copy_from_user(&tmp, user, sizeof(tmp)))
1541 tmp.name[sizeof(tmp.name) - 1] = '\0';
1543 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
1548 case EBT_SO_GET_INFO:
1549 case EBT_SO_GET_INIT_INFO:
1550 if (*len != sizeof(struct ebt_replace)) {
1552 mutex_unlock(&ebt_mutex);
1555 if (cmd == EBT_SO_GET_INFO) {
1556 tmp.nentries = t->private->nentries;
1557 tmp.entries_size = t->private->entries_size;
1558 tmp.valid_hooks = t->valid_hooks;
1560 tmp.nentries = t->table->nentries;
1561 tmp.entries_size = t->table->entries_size;
1562 tmp.valid_hooks = t->table->valid_hooks;
1564 mutex_unlock(&ebt_mutex);
1565 if (copy_to_user(user, &tmp, *len) != 0) {
1566 BUGPRINT("c2u Didn't work\n");
1573 case EBT_SO_GET_ENTRIES:
1574 case EBT_SO_GET_INIT_ENTRIES:
1575 ret = copy_everything_to_user(t, user, len, cmd);
1576 mutex_unlock(&ebt_mutex);
1580 mutex_unlock(&ebt_mutex);
1587 #ifdef CONFIG_COMPAT
1588 /* 32 bit-userspace compatibility definitions. */
1589 struct compat_ebt_replace {
1590 char name[EBT_TABLE_MAXNAMELEN];
1591 compat_uint_t valid_hooks;
1592 compat_uint_t nentries;
1593 compat_uint_t entries_size;
1594 /* start of the chains */
1595 compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
1596 /* nr of counters userspace expects back */
1597 compat_uint_t num_counters;
1598 /* where the kernel will put the old counters. */
1599 compat_uptr_t counters;
1600 compat_uptr_t entries;
1603 /* struct ebt_entry_match, _target and _watcher have same layout */
1604 struct compat_ebt_entry_mwt {
1607 char name[EBT_EXTENSION_MAXNAMELEN];
1612 compat_uint_t match_size;
1613 compat_uint_t data[0];
1616 /* account for possible padding between match_size and ->data */
1617 static int ebt_compat_entry_padsize(void)
1619 BUILD_BUG_ON(XT_ALIGN(sizeof(struct ebt_entry_match)) <
1620 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt)));
1621 return (int) XT_ALIGN(sizeof(struct ebt_entry_match)) -
1622 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt));
1625 static int ebt_compat_match_offset(const struct xt_match *match,
1626 unsigned int userlen)
1628 /* ebt_among needs special handling. The kernel .matchsize is
1629 * set to -1 at registration time; at runtime an EBT_ALIGN()ed
1630 * value is expected.
1631 * Example: userspace sends 4500, ebt_among.c wants 4504.
1633 if (unlikely(match->matchsize == -1))
1634 return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
1635 return xt_compat_match_offset(match);
1638 static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
1641 const struct xt_match *match = m->u.match;
1642 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1643 int off = ebt_compat_match_offset(match, m->match_size);
1644 compat_uint_t msize = m->match_size - off;
1646 if (WARN_ON(off >= m->match_size))
1649 if (copy_to_user(cm->u.name, match->name, strlen(match->name) + 1) ||
1650 put_user(match->revision, &cm->u.revision) ||
1651 put_user(msize, &cm->match_size))
1654 if (match->compat_to_user) {
1655 if (match->compat_to_user(cm->data, m->data))
1658 if (xt_data_to_user(cm->data, m->data, match->usersize, msize,
1659 COMPAT_XT_ALIGN(msize)))
1663 *size -= ebt_compat_entry_padsize() + off;
1669 static int compat_target_to_user(struct ebt_entry_target *t,
1670 void __user **dstptr,
1673 const struct xt_target *target = t->u.target;
1674 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1675 int off = xt_compat_target_offset(target);
1676 compat_uint_t tsize = t->target_size - off;
1678 if (WARN_ON(off >= t->target_size))
1681 if (copy_to_user(cm->u.name, target->name, strlen(target->name) + 1) ||
1682 put_user(target->revision, &cm->u.revision) ||
1683 put_user(tsize, &cm->match_size))
1686 if (target->compat_to_user) {
1687 if (target->compat_to_user(cm->data, t->data))
1690 if (xt_data_to_user(cm->data, t->data, target->usersize, tsize,
1691 COMPAT_XT_ALIGN(tsize)))
1695 *size -= ebt_compat_entry_padsize() + off;
1701 static int compat_watcher_to_user(struct ebt_entry_watcher *w,
1702 void __user **dstptr,
1705 return compat_target_to_user((struct ebt_entry_target *)w,
1709 static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
1712 struct ebt_entry_target *t;
1713 struct ebt_entry __user *ce;
1714 u32 watchers_offset, target_offset, next_offset;
1715 compat_uint_t origsize;
1718 if (e->bitmask == 0) {
1719 if (*size < sizeof(struct ebt_entries))
1721 if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries)))
1724 *dstptr += sizeof(struct ebt_entries);
1725 *size -= sizeof(struct ebt_entries);
1729 if (*size < sizeof(*ce))
1733 if (copy_to_user(ce, e, sizeof(*ce)))
1737 *dstptr += sizeof(*ce);
1739 ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
1742 watchers_offset = e->watchers_offset - (origsize - *size);
1744 ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
1747 target_offset = e->target_offset - (origsize - *size);
1749 t = (struct ebt_entry_target *) ((char *) e + e->target_offset);
1751 ret = compat_target_to_user(t, dstptr, size);
1754 next_offset = e->next_offset - (origsize - *size);
1756 if (put_user(watchers_offset, &ce->watchers_offset) ||
1757 put_user(target_offset, &ce->target_offset) ||
1758 put_user(next_offset, &ce->next_offset))
1761 *size -= sizeof(*ce);
1765 static int compat_calc_match(struct ebt_entry_match *m, int *off)
1767 *off += ebt_compat_match_offset(m->u.match, m->match_size);
1768 *off += ebt_compat_entry_padsize();
1772 static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
1774 *off += xt_compat_target_offset(w->u.watcher);
1775 *off += ebt_compat_entry_padsize();
1779 static int compat_calc_entry(const struct ebt_entry *e,
1780 const struct ebt_table_info *info,
1782 struct compat_ebt_replace *newinfo)
1784 const struct ebt_entry_target *t;
1785 unsigned int entry_offset;
1788 if (e->bitmask == 0)
1792 entry_offset = (void *)e - base;
1794 EBT_MATCH_ITERATE(e, compat_calc_match, &off);
1795 EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
1797 t = (const struct ebt_entry_target *) ((char *) e + e->target_offset);
1799 off += xt_compat_target_offset(t->u.target);
1800 off += ebt_compat_entry_padsize();
1802 newinfo->entries_size -= off;
1804 ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off);
1808 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1809 const void *hookptr = info->hook_entry[i];
1810 if (info->hook_entry[i] &&
1811 (e < (struct ebt_entry *)(base - hookptr))) {
1812 newinfo->hook_entry[i] -= off;
1813 pr_debug("0x%08X -> 0x%08X\n",
1814 newinfo->hook_entry[i] + off,
1815 newinfo->hook_entry[i]);
1823 static int compat_table_info(const struct ebt_table_info *info,
1824 struct compat_ebt_replace *newinfo)
1826 unsigned int size = info->entries_size;
1827 const void *entries = info->entries;
1829 newinfo->entries_size = size;
1830 if (info->nentries) {
1831 int ret = xt_compat_init_offsets(NFPROTO_BRIDGE,
1837 return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
1841 static int compat_copy_everything_to_user(struct ebt_table *t,
1842 void __user *user, int *len, int cmd)
1844 struct compat_ebt_replace repl, tmp;
1845 struct ebt_counter *oldcounters;
1846 struct ebt_table_info tinfo;
1850 memset(&tinfo, 0, sizeof(tinfo));
1852 if (cmd == EBT_SO_GET_ENTRIES) {
1853 tinfo.entries_size = t->private->entries_size;
1854 tinfo.nentries = t->private->nentries;
1855 tinfo.entries = t->private->entries;
1856 oldcounters = t->private->counters;
1858 tinfo.entries_size = t->table->entries_size;
1859 tinfo.nentries = t->table->nentries;
1860 tinfo.entries = t->table->entries;
1861 oldcounters = t->table->counters;
1864 if (copy_from_user(&tmp, user, sizeof(tmp)))
1867 if (tmp.nentries != tinfo.nentries ||
1868 (tmp.num_counters && tmp.num_counters != tinfo.nentries))
1871 memcpy(&repl, &tmp, sizeof(repl));
1872 if (cmd == EBT_SO_GET_ENTRIES)
1873 ret = compat_table_info(t->private, &repl);
1875 ret = compat_table_info(&tinfo, &repl);
1879 if (*len != sizeof(tmp) + repl.entries_size +
1880 (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
1881 pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
1882 *len, tinfo.entries_size, repl.entries_size);
1886 /* userspace might not need the counters */
1887 ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters),
1888 tmp.num_counters, tinfo.nentries);
1892 pos = compat_ptr(tmp.entries);
1893 return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
1894 compat_copy_entry_to_user, &pos, &tmp.entries_size);
1897 struct ebt_entries_buf_state {
1898 char *buf_kern_start; /* kernel buffer to copy (translated) data to */
1899 u32 buf_kern_len; /* total size of kernel buffer */
1900 u32 buf_kern_offset; /* amount of data copied so far */
1901 u32 buf_user_offset; /* read position in userspace buffer */
1904 static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
1906 state->buf_kern_offset += sz;
1907 return state->buf_kern_offset >= sz ? 0 : -EINVAL;
1910 static int ebt_buf_add(struct ebt_entries_buf_state *state,
1911 void *data, unsigned int sz)
1913 if (state->buf_kern_start == NULL)
1916 if (WARN_ON(state->buf_kern_offset + sz > state->buf_kern_len))
1919 memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz);
1922 state->buf_user_offset += sz;
1923 return ebt_buf_count(state, sz);
1926 static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz)
1928 char *b = state->buf_kern_start;
1930 if (WARN_ON(b && state->buf_kern_offset > state->buf_kern_len))
1933 if (b != NULL && sz > 0)
1934 memset(b + state->buf_kern_offset, 0, sz);
1935 /* do not adjust ->buf_user_offset here, we added kernel-side padding */
1936 return ebt_buf_count(state, sz);
1945 static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt,
1946 enum compat_mwt compat_mwt,
1947 struct ebt_entries_buf_state *state,
1948 const unsigned char *base)
1950 char name[EBT_EXTENSION_MAXNAMELEN];
1951 struct xt_match *match;
1952 struct xt_target *wt;
1955 unsigned int size_kern, match_size = mwt->match_size;
1957 strlcpy(name, mwt->u.name, sizeof(name));
1959 if (state->buf_kern_start)
1960 dst = state->buf_kern_start + state->buf_kern_offset;
1962 switch (compat_mwt) {
1963 case EBT_COMPAT_MATCH:
1964 match = xt_request_find_match(NFPROTO_BRIDGE, name,
1967 return PTR_ERR(match);
1969 off = ebt_compat_match_offset(match, match_size);
1971 if (match->compat_from_user)
1972 match->compat_from_user(dst, mwt->data);
1974 memcpy(dst, mwt->data, match_size);
1977 size_kern = match->matchsize;
1978 if (unlikely(size_kern == -1))
1979 size_kern = match_size;
1980 module_put(match->me);
1982 case EBT_COMPAT_WATCHER: /* fallthrough */
1983 case EBT_COMPAT_TARGET:
1984 wt = xt_request_find_target(NFPROTO_BRIDGE, name,
1988 off = xt_compat_target_offset(wt);
1991 if (wt->compat_from_user)
1992 wt->compat_from_user(dst, mwt->data);
1994 memcpy(dst, mwt->data, match_size);
1997 size_kern = wt->targetsize;
2005 state->buf_kern_offset += match_size + off;
2006 state->buf_user_offset += match_size;
2007 pad = XT_ALIGN(size_kern) - size_kern;
2009 if (pad > 0 && dst) {
2010 if (WARN_ON(state->buf_kern_len <= pad))
2012 if (WARN_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad))
2014 memset(dst + size_kern, 0, pad);
2016 return off + match_size;
2019 /* return size of all matches, watchers or target, including necessary
2020 * alignment and padding.
2022 static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32,
2023 unsigned int size_left, enum compat_mwt type,
2024 struct ebt_entries_buf_state *state, const void *base)
2032 buf = (char *) match32;
2034 while (size_left >= sizeof(*match32)) {
2035 struct ebt_entry_match *match_kern;
2038 match_kern = (struct ebt_entry_match *) state->buf_kern_start;
2041 tmp = state->buf_kern_start + state->buf_kern_offset;
2042 match_kern = (struct ebt_entry_match *) tmp;
2044 ret = ebt_buf_add(state, buf, sizeof(*match32));
2047 size_left -= sizeof(*match32);
2049 /* add padding before match->data (if any) */
2050 ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize());
2054 if (match32->match_size > size_left)
2057 size_left -= match32->match_size;
2059 ret = compat_mtw_from_user(match32, type, state, base);
2063 if (WARN_ON(ret < match32->match_size))
2065 growth += ret - match32->match_size;
2066 growth += ebt_compat_entry_padsize();
2068 buf += sizeof(*match32);
2069 buf += match32->match_size;
2072 match_kern->match_size = ret;
2074 if (WARN_ON(type == EBT_COMPAT_TARGET && size_left))
2077 match32 = (struct compat_ebt_entry_mwt *) buf;
2083 /* called for all ebt_entry structures. */
2084 static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,
2085 unsigned int *total,
2086 struct ebt_entries_buf_state *state)
2088 unsigned int i, j, startoff, new_offset = 0;
2089 /* stores match/watchers/targets & offset of next struct ebt_entry: */
2090 unsigned int offsets[4];
2091 unsigned int *offsets_update = NULL;
2095 if (*total < sizeof(struct ebt_entries))
2098 if (!entry->bitmask) {
2099 *total -= sizeof(struct ebt_entries);
2100 return ebt_buf_add(state, entry, sizeof(struct ebt_entries));
2102 if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
2105 startoff = state->buf_user_offset;
2106 /* pull in most part of ebt_entry, it does not need to be changed. */
2107 ret = ebt_buf_add(state, entry,
2108 offsetof(struct ebt_entry, watchers_offset));
2112 offsets[0] = sizeof(struct ebt_entry); /* matches come first */
2113 memcpy(&offsets[1], &entry->watchers_offset,
2114 sizeof(offsets) - sizeof(offsets[0]));
2116 if (state->buf_kern_start) {
2117 buf_start = state->buf_kern_start + state->buf_kern_offset;
2118 offsets_update = (unsigned int *) buf_start;
2120 ret = ebt_buf_add(state, &offsets[1],
2121 sizeof(offsets) - sizeof(offsets[0]));
2124 buf_start = (char *) entry;
2125 /* 0: matches offset, always follows ebt_entry.
2126 * 1: watchers offset, from ebt_entry structure
2127 * 2: target offset, from ebt_entry structure
2128 * 3: next ebt_entry offset, from ebt_entry structure
2130 * offsets are relative to beginning of struct ebt_entry (i.e., 0).
2132 for (i = 0; i < 4 ; ++i) {
2133 if (offsets[i] > *total)
2136 if (i < 3 && offsets[i] == *total)
2141 if (offsets[i-1] > offsets[i])
2145 for (i = 0, j = 1 ; j < 4 ; j++, i++) {
2146 struct compat_ebt_entry_mwt *match32;
2148 char *buf = buf_start + offsets[i];
2150 if (offsets[i] > offsets[j])
2153 match32 = (struct compat_ebt_entry_mwt *) buf;
2154 size = offsets[j] - offsets[i];
2155 ret = ebt_size_mwt(match32, size, i, state, base);
2159 if (offsets_update && new_offset) {
2160 pr_debug("change offset %d to %d\n",
2161 offsets_update[i], offsets[j] + new_offset);
2162 offsets_update[i] = offsets[j] + new_offset;
2166 if (state->buf_kern_start == NULL) {
2167 unsigned int offset = buf_start - (char *) base;
2169 ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);
2174 startoff = state->buf_user_offset - startoff;
2176 if (WARN_ON(*total < startoff))
2182 /* repl->entries_size is the size of the ebt_entry blob in userspace.
2183 * It might need more memory when copied to a 64 bit kernel in case
2184 * userspace is 32-bit. So, first task: find out how much memory is needed.
2186 * Called before validation is performed.
2188 static int compat_copy_entries(unsigned char *data, unsigned int size_user,
2189 struct ebt_entries_buf_state *state)
2191 unsigned int size_remaining = size_user;
2194 ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
2195 &size_remaining, state);
2199 WARN_ON(size_remaining);
2200 return state->buf_kern_offset;
2204 static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
2205 void __user *user, unsigned int len)
2207 struct compat_ebt_replace tmp;
2210 if (len < sizeof(tmp))
2213 if (copy_from_user(&tmp, user, sizeof(tmp)))
2216 if (len != sizeof(tmp) + tmp.entries_size)
2219 if (tmp.entries_size == 0)
2222 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
2223 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
2225 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
2228 memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
2230 /* starting with hook_entry, 32 vs. 64 bit structures are different */
2231 for (i = 0; i < NF_BR_NUMHOOKS; i++)
2232 repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]);
2234 repl->num_counters = tmp.num_counters;
2235 repl->counters = compat_ptr(tmp.counters);
2236 repl->entries = compat_ptr(tmp.entries);
2240 static int compat_do_replace(struct net *net, void __user *user,
2243 int ret, i, countersize, size64;
2244 struct ebt_table_info *newinfo;
2245 struct ebt_replace tmp;
2246 struct ebt_entries_buf_state state;
2249 ret = compat_copy_ebt_replace_from_user(&tmp, user, len);
2251 /* try real handler in case userland supplied needed padding */
2252 if (ret == -EINVAL && do_replace(net, user, len) == 0)
2257 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
2258 newinfo = vmalloc(sizeof(*newinfo) + countersize);
2263 memset(newinfo->counters, 0, countersize);
2265 memset(&state, 0, sizeof(state));
2267 newinfo->entries = vmalloc(tmp.entries_size);
2268 if (!newinfo->entries) {
2273 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
2278 entries_tmp = newinfo->entries;
2280 xt_compat_lock(NFPROTO_BRIDGE);
2282 ret = xt_compat_init_offsets(NFPROTO_BRIDGE, tmp.nentries);
2285 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2289 pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
2290 tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
2291 xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
2294 newinfo->entries = vmalloc(size64);
2295 if (!newinfo->entries) {
2301 memset(&state, 0, sizeof(state));
2302 state.buf_kern_start = newinfo->entries;
2303 state.buf_kern_len = size64;
2305 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2306 if (WARN_ON(ret < 0))
2310 tmp.entries_size = size64;
2312 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
2313 char __user *usrptr;
2314 if (tmp.hook_entry[i]) {
2316 usrptr = (char __user *) tmp.hook_entry[i];
2317 delta = usrptr - tmp.entries;
2318 usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta);
2319 tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
2323 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2324 xt_compat_unlock(NFPROTO_BRIDGE);
2326 ret = do_replace_finish(net, &tmp, newinfo);
2330 vfree(newinfo->entries);
2335 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2336 xt_compat_unlock(NFPROTO_BRIDGE);
2340 static int compat_update_counters(struct net *net, void __user *user,
2343 struct compat_ebt_replace hlp;
2345 if (copy_from_user(&hlp, user, sizeof(hlp)))
2348 /* try real handler in case userland supplied needed padding */
2349 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
2350 return update_counters(net, user, len);
2352 return do_update_counters(net, hlp.name, compat_ptr(hlp.counters),
2353 hlp.num_counters, user, len);
2356 static int compat_do_ebt_set_ctl(struct sock *sk,
2357 int cmd, void __user *user, unsigned int len)
2360 struct net *net = sock_net(sk);
2362 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2366 case EBT_SO_SET_ENTRIES:
2367 ret = compat_do_replace(net, user, len);
2369 case EBT_SO_SET_COUNTERS:
2370 ret = compat_update_counters(net, user, len);
2378 static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
2379 void __user *user, int *len)
2382 struct compat_ebt_replace tmp;
2383 struct ebt_table *t;
2384 struct net *net = sock_net(sk);
2386 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2389 /* try real handler in case userland supplied needed padding */
2390 if ((cmd == EBT_SO_GET_INFO ||
2391 cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp))
2392 return do_ebt_get_ctl(sk, cmd, user, len);
2394 if (copy_from_user(&tmp, user, sizeof(tmp)))
2397 tmp.name[sizeof(tmp.name) - 1] = '\0';
2399 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
2403 xt_compat_lock(NFPROTO_BRIDGE);
2405 case EBT_SO_GET_INFO:
2406 tmp.nentries = t->private->nentries;
2407 ret = compat_table_info(t->private, &tmp);
2410 tmp.valid_hooks = t->valid_hooks;
2412 if (copy_to_user(user, &tmp, *len) != 0) {
2418 case EBT_SO_GET_INIT_INFO:
2419 tmp.nentries = t->table->nentries;
2420 tmp.entries_size = t->table->entries_size;
2421 tmp.valid_hooks = t->table->valid_hooks;
2423 if (copy_to_user(user, &tmp, *len) != 0) {
2429 case EBT_SO_GET_ENTRIES:
2430 case EBT_SO_GET_INIT_ENTRIES:
2431 /* try real handler first in case of userland-side padding.
2432 * in case we are dealing with an 'ordinary' 32 bit binary
2433 * without 64bit compatibility padding, this will fail right
2434 * after copy_from_user when the *len argument is validated.
2436 * the compat_ variant needs to do one pass over the kernel
2437 * data set to adjust for size differences before it the check.
2439 if (copy_everything_to_user(t, user, len, cmd) == 0)
2442 ret = compat_copy_everything_to_user(t, user, len, cmd);
2448 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2449 xt_compat_unlock(NFPROTO_BRIDGE);
2450 mutex_unlock(&ebt_mutex);
2455 static struct nf_sockopt_ops ebt_sockopts = {
2457 .set_optmin = EBT_BASE_CTL,
2458 .set_optmax = EBT_SO_SET_MAX + 1,
2459 .set = do_ebt_set_ctl,
2460 #ifdef CONFIG_COMPAT
2461 .compat_set = compat_do_ebt_set_ctl,
2463 .get_optmin = EBT_BASE_CTL,
2464 .get_optmax = EBT_SO_GET_MAX + 1,
2465 .get = do_ebt_get_ctl,
2466 #ifdef CONFIG_COMPAT
2467 .compat_get = compat_do_ebt_get_ctl,
2469 .owner = THIS_MODULE,
2472 static int __init ebtables_init(void)
2476 ret = xt_register_target(&ebt_standard_target);
2479 ret = nf_register_sockopt(&ebt_sockopts);
2481 xt_unregister_target(&ebt_standard_target);
2488 static void __exit ebtables_fini(void)
2490 nf_unregister_sockopt(&ebt_sockopts);
2491 xt_unregister_target(&ebt_standard_target);
2494 EXPORT_SYMBOL(ebt_register_table);
2495 EXPORT_SYMBOL(ebt_unregister_table);
2496 EXPORT_SYMBOL(ebt_do_table);
2497 module_init(ebtables_init);
2498 module_exit(ebtables_fini);
2499 MODULE_LICENSE("GPL");