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 /* Each cpu has its own set of counters, so there is no need for write_lock in
36 * For reading or updating the counters, the user context needs to
40 /* The size of each set of counters is altered to get cache alignment */
41 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
42 #define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter)))
43 #define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \
44 COUNTER_OFFSET(n) * cpu))
48 static DEFINE_MUTEX(ebt_mutex);
51 static void ebt_standard_compat_from_user(void *dst, const void *src)
53 int v = *(compat_int_t *)src;
56 v += xt_compat_calc_jump(NFPROTO_BRIDGE, v);
57 memcpy(dst, &v, sizeof(v));
60 static int ebt_standard_compat_to_user(void __user *dst, const void *src)
62 compat_int_t cv = *(int *)src;
65 cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv);
66 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
71 static struct xt_target ebt_standard_target = {
74 .family = NFPROTO_BRIDGE,
75 .targetsize = sizeof(int),
77 .compatsize = sizeof(compat_int_t),
78 .compat_from_user = ebt_standard_compat_from_user,
79 .compat_to_user = ebt_standard_compat_to_user,
84 ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb,
85 struct xt_action_param *par)
87 par->target = w->u.watcher;
88 par->targinfo = w->data;
89 w->u.watcher->target(skb, par);
90 /* watchers don't give a verdict */
95 ebt_do_match(struct ebt_entry_match *m, const struct sk_buff *skb,
96 struct xt_action_param *par)
98 par->match = m->u.match;
99 par->matchinfo = m->data;
100 return m->u.match->match(skb, par) ? EBT_MATCH : EBT_NOMATCH;
104 ebt_dev_check(const char *entry, const struct net_device *device)
113 devname = device->name;
114 /* 1 is the wildcard token */
115 while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i])
117 return devname[i] != entry[i] && entry[i] != 1;
120 /* process standard matches */
122 ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb,
123 const struct net_device *in, const struct net_device *out)
125 const struct ethhdr *h = eth_hdr(skb);
126 const struct net_bridge_port *p;
129 if (skb_vlan_tag_present(skb))
130 ethproto = htons(ETH_P_8021Q);
132 ethproto = h->h_proto;
134 if (e->bitmask & EBT_802_3) {
135 if (NF_INVF(e, EBT_IPROTO, eth_proto_is_802_3(ethproto)))
137 } else if (!(e->bitmask & EBT_NOPROTO) &&
138 NF_INVF(e, EBT_IPROTO, e->ethproto != ethproto))
141 if (NF_INVF(e, EBT_IIN, ebt_dev_check(e->in, in)))
143 if (NF_INVF(e, EBT_IOUT, ebt_dev_check(e->out, out)))
145 /* rcu_read_lock()ed by nf_hook_thresh */
146 if (in && (p = br_port_get_rcu(in)) != NULL &&
147 NF_INVF(e, EBT_ILOGICALIN,
148 ebt_dev_check(e->logical_in, p->br->dev)))
150 if (out && (p = br_port_get_rcu(out)) != NULL &&
151 NF_INVF(e, EBT_ILOGICALOUT,
152 ebt_dev_check(e->logical_out, p->br->dev)))
155 if (e->bitmask & EBT_SOURCEMAC) {
156 if (NF_INVF(e, EBT_ISOURCE,
157 !ether_addr_equal_masked(h->h_source, e->sourcemac,
161 if (e->bitmask & EBT_DESTMAC) {
162 if (NF_INVF(e, EBT_IDEST,
163 !ether_addr_equal_masked(h->h_dest, e->destmac,
171 struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry)
173 return (void *)entry + entry->next_offset;
176 /* Do some firewalling */
177 unsigned int ebt_do_table(struct sk_buff *skb,
178 const struct nf_hook_state *state,
179 struct ebt_table *table)
181 unsigned int hook = state->hook;
183 struct ebt_entry *point;
184 struct ebt_counter *counter_base, *cb_base;
185 const struct ebt_entry_target *t;
187 struct ebt_chainstack *cs;
188 struct ebt_entries *chaininfo;
190 const struct ebt_table_info *private;
191 struct xt_action_param acpar;
194 acpar.hotdrop = false;
196 read_lock_bh(&table->lock);
197 private = table->private;
198 cb_base = COUNTER_BASE(private->counters, private->nentries,
200 if (private->chainstack)
201 cs = private->chainstack[smp_processor_id()];
204 chaininfo = private->hook_entry[hook];
205 nentries = private->hook_entry[hook]->nentries;
206 point = (struct ebt_entry *)(private->hook_entry[hook]->data);
207 counter_base = cb_base + private->hook_entry[hook]->counter_offset;
208 /* base for chain jumps */
209 base = private->entries;
211 while (i < nentries) {
212 if (ebt_basic_match(point, skb, state->in, state->out))
215 if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0)
218 read_unlock_bh(&table->lock);
222 /* increase counter */
223 (*(counter_base + i)).pcnt++;
224 (*(counter_base + i)).bcnt += skb->len;
226 /* these should only watch: not modify, nor tell us
227 * what to do with the packet
229 EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar);
231 t = (struct ebt_entry_target *)
232 (((char *)point) + point->target_offset);
233 /* standard target */
234 if (!t->u.target->target)
235 verdict = ((struct ebt_standard_target *)t)->verdict;
237 acpar.target = t->u.target;
238 acpar.targinfo = t->data;
239 verdict = t->u.target->target(skb, &acpar);
241 if (verdict == EBT_ACCEPT) {
242 read_unlock_bh(&table->lock);
245 if (verdict == EBT_DROP) {
246 read_unlock_bh(&table->lock);
249 if (verdict == EBT_RETURN) {
251 if (WARN(sp == 0, "RETURN on base chain")) {
252 /* act like this is EBT_CONTINUE */
257 /* put all the local variables right */
259 chaininfo = cs[sp].chaininfo;
260 nentries = chaininfo->nentries;
262 counter_base = cb_base +
263 chaininfo->counter_offset;
266 if (verdict == EBT_CONTINUE)
269 if (WARN(verdict < 0, "bogus standard verdict\n")) {
270 read_unlock_bh(&table->lock);
276 cs[sp].chaininfo = chaininfo;
277 cs[sp].e = ebt_next_entry(point);
279 chaininfo = (struct ebt_entries *) (base + verdict);
281 if (WARN(chaininfo->distinguisher, "jump to non-chain\n")) {
282 read_unlock_bh(&table->lock);
286 nentries = chaininfo->nentries;
287 point = (struct ebt_entry *)chaininfo->data;
288 counter_base = cb_base + chaininfo->counter_offset;
292 point = ebt_next_entry(point);
296 /* I actually like this :) */
297 if (chaininfo->policy == EBT_RETURN)
299 if (chaininfo->policy == EBT_ACCEPT) {
300 read_unlock_bh(&table->lock);
303 read_unlock_bh(&table->lock);
307 /* If it succeeds, returns element and locks mutex */
309 find_inlist_lock_noload(struct list_head *head, const char *name, int *error,
313 struct list_head list;
314 char name[EBT_FUNCTION_MAXNAMELEN];
318 list_for_each_entry(e, head, list) {
319 if (strcmp(e->name, name) == 0)
328 find_inlist_lock(struct list_head *head, const char *name, const char *prefix,
329 int *error, struct mutex *mutex)
331 return try_then_request_module(
332 find_inlist_lock_noload(head, name, error, mutex),
333 "%s%s", prefix, name);
336 static inline struct ebt_table *
337 find_table_lock(struct net *net, const char *name, int *error,
340 return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name,
341 "ebtable_", error, mutex);
345 ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
348 const struct ebt_entry *e = par->entryinfo;
349 struct xt_match *match;
350 size_t left = ((char *)e + e->watchers_offset) - (char *)m;
353 if (left < sizeof(struct ebt_entry_match) ||
354 left - sizeof(struct ebt_entry_match) < m->match_size)
357 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, 0);
358 if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) {
360 module_put(match->me);
361 request_module("ebt_%s", m->u.name);
362 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, 0);
365 return PTR_ERR(match);
369 par->matchinfo = m->data;
370 ret = xt_check_match(par, m->match_size,
371 e->ethproto, e->invflags & EBT_IPROTO);
373 module_put(match->me);
382 ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
385 const struct ebt_entry *e = par->entryinfo;
386 struct xt_target *watcher;
387 size_t left = ((char *)e + e->target_offset) - (char *)w;
390 if (left < sizeof(struct ebt_entry_watcher) ||
391 left - sizeof(struct ebt_entry_watcher) < w->watcher_size)
394 watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0);
396 return PTR_ERR(watcher);
398 if (watcher->family != NFPROTO_BRIDGE) {
399 module_put(watcher->me);
403 w->u.watcher = watcher;
405 par->target = watcher;
406 par->targinfo = w->data;
407 ret = xt_check_target(par, w->watcher_size,
408 e->ethproto, e->invflags & EBT_IPROTO);
410 module_put(watcher->me);
418 static int ebt_verify_pointers(const struct ebt_replace *repl,
419 struct ebt_table_info *newinfo)
421 unsigned int limit = repl->entries_size;
422 unsigned int valid_hooks = repl->valid_hooks;
423 unsigned int offset = 0;
426 for (i = 0; i < NF_BR_NUMHOOKS; i++)
427 newinfo->hook_entry[i] = NULL;
429 newinfo->entries_size = repl->entries_size;
430 newinfo->nentries = repl->nentries;
432 while (offset < limit) {
433 size_t left = limit - offset;
434 struct ebt_entry *e = (void *)newinfo->entries + offset;
436 if (left < sizeof(unsigned int))
439 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
440 if ((valid_hooks & (1 << i)) == 0)
442 if ((char __user *)repl->hook_entry[i] ==
443 repl->entries + offset)
447 if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
448 if (e->bitmask != 0) {
449 /* we make userspace set this right,
450 * so there is no misunderstanding
454 if (i != NF_BR_NUMHOOKS)
455 newinfo->hook_entry[i] = (struct ebt_entries *)e;
456 if (left < sizeof(struct ebt_entries))
458 offset += sizeof(struct ebt_entries);
460 if (left < sizeof(struct ebt_entry))
462 if (left < e->next_offset)
464 if (e->next_offset < sizeof(struct ebt_entry))
466 offset += e->next_offset;
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)))
481 /* this one is very careful, as it is the first function
482 * to parse the userspace data
485 ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
486 const struct ebt_table_info *newinfo,
487 unsigned int *n, unsigned int *cnt,
488 unsigned int *totalcnt, unsigned int *udc_cnt)
492 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
493 if ((void *)e == (void *)newinfo->hook_entry[i])
496 /* beginning of a new chain
497 * if i == NF_BR_NUMHOOKS it must be a user defined chain
499 if (i != NF_BR_NUMHOOKS || !e->bitmask) {
500 /* this checks if the previous chain has as many entries
506 if (((struct ebt_entries *)e)->policy != EBT_DROP &&
507 ((struct ebt_entries *)e)->policy != EBT_ACCEPT) {
508 /* only RETURN from udc */
509 if (i != NF_BR_NUMHOOKS ||
510 ((struct ebt_entries *)e)->policy != EBT_RETURN)
513 if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */
515 if (((struct ebt_entries *)e)->counter_offset != *totalcnt)
517 *n = ((struct ebt_entries *)e)->nentries;
521 /* a plain old entry, heh */
522 if (sizeof(struct ebt_entry) > e->watchers_offset ||
523 e->watchers_offset > e->target_offset ||
524 e->target_offset >= e->next_offset)
527 /* this is not checked anywhere else */
528 if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target))
536 struct ebt_cl_stack {
537 struct ebt_chainstack cs;
539 unsigned int hookmask;
542 /* We need these positions to check that the jumps to a different part of the
543 * entries is a jump to the beginning of a new chain.
546 ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo,
547 unsigned int *n, struct ebt_cl_stack *udc)
551 /* we're only interested in chain starts */
554 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
555 if (newinfo->hook_entry[i] == (struct ebt_entries *)e)
558 /* only care about udc */
559 if (i != NF_BR_NUMHOOKS)
562 udc[*n].cs.chaininfo = (struct ebt_entries *)e;
563 /* these initialisations are depended on later in check_chainloops() */
565 udc[*n].hookmask = 0;
572 ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i)
574 struct xt_mtdtor_param par;
576 if (i && (*i)-- == 0)
580 par.match = m->u.match;
581 par.matchinfo = m->data;
582 par.family = NFPROTO_BRIDGE;
583 if (par.match->destroy != NULL)
584 par.match->destroy(&par);
585 module_put(par.match->me);
590 ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i)
592 struct xt_tgdtor_param par;
594 if (i && (*i)-- == 0)
598 par.target = w->u.watcher;
599 par.targinfo = w->data;
600 par.family = NFPROTO_BRIDGE;
601 if (par.target->destroy != NULL)
602 par.target->destroy(&par);
603 module_put(par.target->me);
608 ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
610 struct xt_tgdtor_param par;
611 struct ebt_entry_target *t;
616 if (cnt && (*cnt)-- == 0)
618 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL);
619 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL);
620 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
623 par.target = t->u.target;
624 par.targinfo = t->data;
625 par.family = NFPROTO_BRIDGE;
626 if (par.target->destroy != NULL)
627 par.target->destroy(&par);
628 module_put(par.target->me);
633 ebt_check_entry(struct ebt_entry *e, struct net *net,
634 const struct ebt_table_info *newinfo,
635 const char *name, unsigned int *cnt,
636 struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
638 struct ebt_entry_target *t;
639 struct xt_target *target;
640 unsigned int i, j, hook = 0, hookmask = 0;
643 struct xt_mtchk_param mtpar;
644 struct xt_tgchk_param tgpar;
646 /* don't mess with the struct ebt_entries */
650 if (e->bitmask & ~EBT_F_MASK)
653 if (e->invflags & ~EBT_INV_MASK)
656 if ((e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3))
659 /* what hook do we belong to? */
660 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
661 if (!newinfo->hook_entry[i])
663 if ((char *)newinfo->hook_entry[i] < (char *)e)
668 /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on
671 if (i < NF_BR_NUMHOOKS)
672 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
674 for (i = 0; i < udc_cnt; i++)
675 if ((char *)(cl_s[i].cs.chaininfo) > (char *)e)
678 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
680 hookmask = cl_s[i - 1].hookmask;
684 memset(&mtpar, 0, sizeof(mtpar));
685 memset(&tgpar, 0, sizeof(tgpar));
686 mtpar.net = tgpar.net = net;
687 mtpar.table = tgpar.table = name;
688 mtpar.entryinfo = tgpar.entryinfo = e;
689 mtpar.hook_mask = tgpar.hook_mask = hookmask;
690 mtpar.family = tgpar.family = NFPROTO_BRIDGE;
691 ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i);
693 goto cleanup_matches;
695 ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j);
697 goto cleanup_watchers;
698 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
699 gap = e->next_offset - e->target_offset;
701 target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0);
702 if (IS_ERR(target)) {
703 ret = PTR_ERR(target);
704 goto cleanup_watchers;
707 /* Reject UNSPEC, xtables verdicts/return values are incompatible */
708 if (target->family != NFPROTO_BRIDGE) {
709 module_put(target->me);
711 goto cleanup_watchers;
714 t->u.target = target;
715 if (t->u.target == &ebt_standard_target) {
716 if (gap < sizeof(struct ebt_standard_target)) {
718 goto cleanup_watchers;
720 if (((struct ebt_standard_target *)t)->verdict <
721 -NUM_STANDARD_TARGETS) {
723 goto cleanup_watchers;
725 } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) {
726 module_put(t->u.target->me);
728 goto cleanup_watchers;
731 tgpar.target = target;
732 tgpar.targinfo = t->data;
733 ret = xt_check_target(&tgpar, t->target_size,
734 e->ethproto, e->invflags & EBT_IPROTO);
736 module_put(target->me);
737 goto cleanup_watchers;
742 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j);
744 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i);
748 /* checks for loops and sets the hook mask for udc
749 * the hook mask for udc tells us from which base chains the udc can be
750 * accessed. This mask is a parameter to the check() functions of the extensions
752 static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
753 unsigned int udc_cnt, unsigned int hooknr, char *base)
755 int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
756 const struct ebt_entry *e = (struct ebt_entry *)chain->data;
757 const struct ebt_entry_target *t;
759 while (pos < nentries || chain_nr != -1) {
760 /* end of udc, go back one 'recursion' step */
761 if (pos == nentries) {
762 /* put back values of the time when this chain was called */
763 e = cl_s[chain_nr].cs.e;
764 if (cl_s[chain_nr].from != -1)
766 cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries;
768 nentries = chain->nentries;
769 pos = cl_s[chain_nr].cs.n;
770 /* make sure we won't see a loop that isn't one */
771 cl_s[chain_nr].cs.n = 0;
772 chain_nr = cl_s[chain_nr].from;
776 t = (struct ebt_entry_target *)
777 (((char *)e) + e->target_offset);
778 if (strcmp(t->u.name, EBT_STANDARD_TARGET))
780 if (e->target_offset + sizeof(struct ebt_standard_target) >
784 verdict = ((struct ebt_standard_target *)t)->verdict;
785 if (verdict >= 0) { /* jump to another chain */
786 struct ebt_entries *hlp2 =
787 (struct ebt_entries *)(base + verdict);
788 for (i = 0; i < udc_cnt; i++)
789 if (hlp2 == cl_s[i].cs.chaininfo)
791 /* bad destination or loop */
798 if (cl_s[i].hookmask & (1 << hooknr))
800 /* this can't be 0, so the loop test is correct */
801 cl_s[i].cs.n = pos + 1;
803 cl_s[i].cs.e = ebt_next_entry(e);
804 e = (struct ebt_entry *)(hlp2->data);
805 nentries = hlp2->nentries;
806 cl_s[i].from = chain_nr;
808 /* this udc is accessible from the base chain for hooknr */
809 cl_s[i].hookmask |= (1 << hooknr);
813 e = ebt_next_entry(e);
819 /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
820 static int translate_table(struct net *net, const char *name,
821 struct ebt_table_info *newinfo)
823 unsigned int i, j, k, udc_cnt;
825 struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */
828 while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i])
830 if (i == NF_BR_NUMHOOKS)
833 if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries)
836 /* make sure chains are ordered after each other in same order
837 * as their corresponding hooks
839 for (j = i + 1; j < NF_BR_NUMHOOKS; j++) {
840 if (!newinfo->hook_entry[j])
842 if (newinfo->hook_entry[j] <= newinfo->hook_entry[i])
848 /* do some early checkings and initialize some things */
849 i = 0; /* holds the expected nr. of entries for the chain */
850 j = 0; /* holds the up to now counted entries for the chain */
851 k = 0; /* holds the total nr. of entries, should equal
852 * newinfo->nentries afterwards
854 udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */
855 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
856 ebt_check_entry_size_and_hooks, newinfo,
857 &i, &j, &k, &udc_cnt);
865 if (k != newinfo->nentries)
868 /* get the location of the udc, put them in an array
869 * while we're at it, allocate the chainstack
872 /* this will get free'd in do_replace()/ebt_register_table()
875 newinfo->chainstack =
876 vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack)));
877 if (!newinfo->chainstack)
879 for_each_possible_cpu(i) {
880 newinfo->chainstack[i] =
881 vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0])));
882 if (!newinfo->chainstack[i]) {
884 vfree(newinfo->chainstack[--i]);
885 vfree(newinfo->chainstack);
886 newinfo->chainstack = NULL;
891 cl_s = vmalloc(udc_cnt * sizeof(*cl_s));
894 i = 0; /* the i'th udc */
895 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
896 ebt_get_udc_positions, newinfo, &i, cl_s);
904 /* Check for loops */
905 for (i = 0; i < NF_BR_NUMHOOKS; i++)
906 if (newinfo->hook_entry[i])
907 if (check_chainloops(newinfo->hook_entry[i],
908 cl_s, udc_cnt, i, newinfo->entries)) {
913 /* we now know the following (along with E=mc²):
914 * - the nr of entries in each chain is right
915 * - the size of the allocated space is right
916 * - all valid hooks have a corresponding chain
917 * - there are no loops
918 * - wrong data can still be on the level of a single entry
919 * - could be there are jumps to places that are not the
920 * beginning of a chain. This can only occur in chains that
921 * are not accessible from any base chains, so we don't care.
924 /* used to know what we need to clean up if something goes wrong */
926 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
927 ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt);
929 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
930 ebt_cleanup_entry, net, &i);
936 /* called under write_lock */
937 static void get_counters(const struct ebt_counter *oldcounters,
938 struct ebt_counter *counters, unsigned int nentries)
941 struct ebt_counter *counter_base;
943 /* counters of cpu 0 */
944 memcpy(counters, oldcounters,
945 sizeof(struct ebt_counter) * nentries);
947 /* add other counters to those of cpu 0 */
948 for_each_possible_cpu(cpu) {
951 counter_base = COUNTER_BASE(oldcounters, nentries, cpu);
952 for (i = 0; i < nentries; i++) {
953 counters[i].pcnt += counter_base[i].pcnt;
954 counters[i].bcnt += counter_base[i].bcnt;
959 static int do_replace_finish(struct net *net, struct ebt_replace *repl,
960 struct ebt_table_info *newinfo)
963 struct ebt_counter *counterstmp = NULL;
964 /* used to be able to unlock earlier */
965 struct ebt_table_info *table;
968 /* the user wants counters back
969 * the check on the size is done later, when we have the lock
971 if (repl->num_counters) {
972 unsigned long size = repl->num_counters * sizeof(*counterstmp);
973 counterstmp = vmalloc(size);
978 newinfo->chainstack = NULL;
979 ret = ebt_verify_pointers(repl, newinfo);
981 goto free_counterstmp;
983 ret = translate_table(net, repl->name, newinfo);
986 goto free_counterstmp;
988 t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
994 if (repl->valid_hooks != t->valid_hooks) {
999 if (repl->num_counters && repl->num_counters != t->private->nentries) {
1004 /* we have the mutex lock, so no danger in reading this pointer */
1006 /* make sure the table can only be rmmod'ed if it contains no rules */
1007 if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) {
1010 } else if (table->nentries && !newinfo->nentries)
1012 /* we need an atomic snapshot of the counters */
1013 write_lock_bh(&t->lock);
1014 if (repl->num_counters)
1015 get_counters(t->private->counters, counterstmp,
1016 t->private->nentries);
1018 t->private = newinfo;
1019 write_unlock_bh(&t->lock);
1020 mutex_unlock(&ebt_mutex);
1021 /* so, a user can change the chains while having messed up her counter
1022 * allocation. Only reason why this is done is because this way the lock
1023 * is held only once, while this doesn't bring the kernel into a
1026 if (repl->num_counters &&
1027 copy_to_user(repl->counters, counterstmp,
1028 repl->num_counters * sizeof(struct ebt_counter))) {
1029 /* Silent error, can't fail, new table is already in place */
1030 net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n");
1033 /* decrease module count and free resources */
1034 EBT_ENTRY_ITERATE(table->entries, table->entries_size,
1035 ebt_cleanup_entry, net, NULL);
1037 vfree(table->entries);
1038 if (table->chainstack) {
1039 for_each_possible_cpu(i)
1040 vfree(table->chainstack[i]);
1041 vfree(table->chainstack);
1048 if (audit_enabled) {
1049 audit_log(current->audit_context, GFP_KERNEL,
1050 AUDIT_NETFILTER_CFG,
1051 "table=%s family=%u entries=%u",
1052 repl->name, AF_BRIDGE, repl->nentries);
1058 mutex_unlock(&ebt_mutex);
1060 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
1061 ebt_cleanup_entry, net, NULL);
1064 /* can be initialized in translate_table() */
1065 if (newinfo->chainstack) {
1066 for_each_possible_cpu(i)
1067 vfree(newinfo->chainstack[i]);
1068 vfree(newinfo->chainstack);
1073 /* replace the table */
1074 static int do_replace(struct net *net, const void __user *user,
1077 int ret, countersize;
1078 struct ebt_table_info *newinfo;
1079 struct ebt_replace tmp;
1081 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1084 if (len != sizeof(tmp) + tmp.entries_size)
1087 if (tmp.entries_size == 0)
1090 /* overflow check */
1091 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
1092 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
1094 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
1097 tmp.name[sizeof(tmp.name) - 1] = 0;
1099 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
1100 newinfo = __vmalloc(sizeof(*newinfo) + countersize, GFP_KERNEL_ACCOUNT,
1106 memset(newinfo->counters, 0, countersize);
1108 newinfo->entries = __vmalloc(tmp.entries_size, GFP_KERNEL_ACCOUNT,
1110 if (!newinfo->entries) {
1115 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
1120 ret = do_replace_finish(net, &tmp, newinfo);
1124 vfree(newinfo->entries);
1130 static void __ebt_unregister_table(struct net *net, struct ebt_table *table)
1134 mutex_lock(&ebt_mutex);
1135 list_del(&table->list);
1136 mutex_unlock(&ebt_mutex);
1137 EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
1138 ebt_cleanup_entry, net, NULL);
1139 if (table->private->nentries)
1140 module_put(table->me);
1141 vfree(table->private->entries);
1142 if (table->private->chainstack) {
1143 for_each_possible_cpu(i)
1144 vfree(table->private->chainstack[i]);
1145 vfree(table->private->chainstack);
1147 vfree(table->private);
1151 int ebt_register_table(struct net *net, const struct ebt_table *input_table,
1152 const struct nf_hook_ops *ops, struct ebt_table **res)
1154 struct ebt_table_info *newinfo;
1155 struct ebt_table *t, *table;
1156 struct ebt_replace_kernel *repl;
1157 int ret, i, countersize;
1160 if (input_table == NULL || (repl = input_table->table) == NULL ||
1161 repl->entries == NULL || repl->entries_size == 0 ||
1162 repl->counters != NULL || input_table->private != NULL)
1165 /* Don't add one table to multiple lists. */
1166 table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL);
1172 countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
1173 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1178 p = vmalloc(repl->entries_size);
1182 memcpy(p, repl->entries, repl->entries_size);
1183 newinfo->entries = p;
1185 newinfo->entries_size = repl->entries_size;
1186 newinfo->nentries = repl->nentries;
1189 memset(newinfo->counters, 0, countersize);
1191 /* fill in newinfo and parse the entries */
1192 newinfo->chainstack = NULL;
1193 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1194 if ((repl->valid_hooks & (1 << i)) == 0)
1195 newinfo->hook_entry[i] = NULL;
1197 newinfo->hook_entry[i] = p +
1198 ((char *)repl->hook_entry[i] - repl->entries);
1200 ret = translate_table(net, repl->name, newinfo);
1202 goto free_chainstack;
1204 table->private = newinfo;
1205 rwlock_init(&table->lock);
1206 mutex_lock(&ebt_mutex);
1207 list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
1208 if (strcmp(t->name, table->name) == 0) {
1214 /* Hold a reference count if the chains aren't empty */
1215 if (newinfo->nentries && !try_module_get(table->me)) {
1219 list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
1220 mutex_unlock(&ebt_mutex);
1222 WRITE_ONCE(*res, table);
1227 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
1229 __ebt_unregister_table(net, table);
1235 mutex_unlock(&ebt_mutex);
1237 if (newinfo->chainstack) {
1238 for_each_possible_cpu(i)
1239 vfree(newinfo->chainstack[i]);
1240 vfree(newinfo->chainstack);
1242 vfree(newinfo->entries);
1251 void ebt_unregister_table(struct net *net, struct ebt_table *table,
1252 const struct nf_hook_ops *ops)
1255 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
1256 __ebt_unregister_table(net, table);
1259 /* userspace just supplied us with counters */
1260 static int do_update_counters(struct net *net, const char *name,
1261 struct ebt_counter __user *counters,
1262 unsigned int num_counters,
1263 const void __user *user, unsigned int len)
1266 struct ebt_counter *tmp;
1267 struct ebt_table *t;
1269 if (num_counters == 0)
1272 tmp = vmalloc(num_counters * sizeof(*tmp));
1276 t = find_table_lock(net, name, &ret, &ebt_mutex);
1280 if (num_counters != t->private->nentries) {
1285 if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) {
1290 /* we want an atomic add of the counters */
1291 write_lock_bh(&t->lock);
1293 /* we add to the counters of the first cpu */
1294 for (i = 0; i < num_counters; i++) {
1295 t->private->counters[i].pcnt += tmp[i].pcnt;
1296 t->private->counters[i].bcnt += tmp[i].bcnt;
1299 write_unlock_bh(&t->lock);
1302 mutex_unlock(&ebt_mutex);
1308 static int update_counters(struct net *net, const void __user *user,
1311 struct ebt_replace hlp;
1313 if (copy_from_user(&hlp, user, sizeof(hlp)))
1316 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
1319 return do_update_counters(net, hlp.name, hlp.counters,
1320 hlp.num_counters, user, len);
1323 static inline int ebt_obj_to_user(char __user *um, const char *_name,
1324 const char *data, int entrysize,
1325 int usersize, int datasize)
1327 char name[EBT_FUNCTION_MAXNAMELEN] = {0};
1329 /* ebtables expects 32 bytes long names but xt_match names are 29 bytes
1330 * long. Copy 29 bytes and fill remaining bytes with zeroes.
1332 strlcpy(name, _name, sizeof(name));
1333 if (copy_to_user(um, name, EBT_FUNCTION_MAXNAMELEN) ||
1334 put_user(datasize, (int __user *)(um + EBT_FUNCTION_MAXNAMELEN)) ||
1335 xt_data_to_user(um + entrysize, data, usersize, datasize,
1336 XT_ALIGN(datasize)))
1342 static inline int ebt_match_to_user(const struct ebt_entry_match *m,
1343 const char *base, char __user *ubase)
1345 return ebt_obj_to_user(ubase + ((char *)m - base),
1346 m->u.match->name, m->data, sizeof(*m),
1347 m->u.match->usersize, m->match_size);
1350 static inline int ebt_watcher_to_user(const struct ebt_entry_watcher *w,
1351 const char *base, char __user *ubase)
1353 return ebt_obj_to_user(ubase + ((char *)w - base),
1354 w->u.watcher->name, w->data, sizeof(*w),
1355 w->u.watcher->usersize, w->watcher_size);
1358 static inline int ebt_entry_to_user(struct ebt_entry *e, const char *base,
1363 const struct ebt_entry_target *t;
1365 if (e->bitmask == 0) {
1366 /* special case !EBT_ENTRY_OR_ENTRIES */
1367 if (copy_to_user(ubase + ((char *)e - base), e,
1368 sizeof(struct ebt_entries)))
1373 if (copy_to_user(ubase + ((char *)e - base), e, sizeof(*e)))
1376 hlp = ubase + (((char *)e + e->target_offset) - base);
1377 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
1379 ret = EBT_MATCH_ITERATE(e, ebt_match_to_user, base, ubase);
1382 ret = EBT_WATCHER_ITERATE(e, ebt_watcher_to_user, base, ubase);
1385 ret = ebt_obj_to_user(hlp, t->u.target->name, t->data, sizeof(*t),
1386 t->u.target->usersize, t->target_size);
1393 static int copy_counters_to_user(struct ebt_table *t,
1394 const struct ebt_counter *oldcounters,
1395 void __user *user, unsigned int num_counters,
1396 unsigned int nentries)
1398 struct ebt_counter *counterstmp;
1401 /* userspace might not need the counters */
1402 if (num_counters == 0)
1405 if (num_counters != nentries)
1408 counterstmp = vmalloc(nentries * sizeof(*counterstmp));
1412 write_lock_bh(&t->lock);
1413 get_counters(oldcounters, counterstmp, nentries);
1414 write_unlock_bh(&t->lock);
1416 if (copy_to_user(user, counterstmp,
1417 nentries * sizeof(struct ebt_counter)))
1423 /* called with ebt_mutex locked */
1424 static int copy_everything_to_user(struct ebt_table *t, void __user *user,
1425 const int *len, int cmd)
1427 struct ebt_replace tmp;
1428 const struct ebt_counter *oldcounters;
1429 unsigned int entries_size, nentries;
1433 if (cmd == EBT_SO_GET_ENTRIES) {
1434 entries_size = t->private->entries_size;
1435 nentries = t->private->nentries;
1436 entries = t->private->entries;
1437 oldcounters = t->private->counters;
1439 entries_size = t->table->entries_size;
1440 nentries = t->table->nentries;
1441 entries = t->table->entries;
1442 oldcounters = t->table->counters;
1445 if (copy_from_user(&tmp, user, sizeof(tmp)))
1448 if (*len != sizeof(struct ebt_replace) + entries_size +
1449 (tmp.num_counters ? nentries * sizeof(struct ebt_counter) : 0))
1452 if (tmp.nentries != nentries)
1455 if (tmp.entries_size != entries_size)
1458 ret = copy_counters_to_user(t, oldcounters, tmp.counters,
1459 tmp.num_counters, nentries);
1463 /* set the match/watcher/target names right */
1464 return EBT_ENTRY_ITERATE(entries, entries_size,
1465 ebt_entry_to_user, entries, tmp.entries);
1468 static int do_ebt_set_ctl(struct sock *sk,
1469 int cmd, void __user *user, unsigned int len)
1472 struct net *net = sock_net(sk);
1474 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1478 case EBT_SO_SET_ENTRIES:
1479 ret = do_replace(net, user, len);
1481 case EBT_SO_SET_COUNTERS:
1482 ret = update_counters(net, user, len);
1490 static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1493 struct ebt_replace tmp;
1494 struct ebt_table *t;
1495 struct net *net = sock_net(sk);
1497 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1500 if (copy_from_user(&tmp, user, sizeof(tmp)))
1503 tmp.name[sizeof(tmp.name) - 1] = '\0';
1505 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
1510 case EBT_SO_GET_INFO:
1511 case EBT_SO_GET_INIT_INFO:
1512 if (*len != sizeof(struct ebt_replace)) {
1514 mutex_unlock(&ebt_mutex);
1517 if (cmd == EBT_SO_GET_INFO) {
1518 tmp.nentries = t->private->nentries;
1519 tmp.entries_size = t->private->entries_size;
1520 tmp.valid_hooks = t->valid_hooks;
1522 tmp.nentries = t->table->nentries;
1523 tmp.entries_size = t->table->entries_size;
1524 tmp.valid_hooks = t->table->valid_hooks;
1526 mutex_unlock(&ebt_mutex);
1527 if (copy_to_user(user, &tmp, *len) != 0) {
1534 case EBT_SO_GET_ENTRIES:
1535 case EBT_SO_GET_INIT_ENTRIES:
1536 ret = copy_everything_to_user(t, user, len, cmd);
1537 mutex_unlock(&ebt_mutex);
1541 mutex_unlock(&ebt_mutex);
1548 #ifdef CONFIG_COMPAT
1549 /* 32 bit-userspace compatibility definitions. */
1550 struct compat_ebt_replace {
1551 char name[EBT_TABLE_MAXNAMELEN];
1552 compat_uint_t valid_hooks;
1553 compat_uint_t nentries;
1554 compat_uint_t entries_size;
1555 /* start of the chains */
1556 compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
1557 /* nr of counters userspace expects back */
1558 compat_uint_t num_counters;
1559 /* where the kernel will put the old counters. */
1560 compat_uptr_t counters;
1561 compat_uptr_t entries;
1564 /* struct ebt_entry_match, _target and _watcher have same layout */
1565 struct compat_ebt_entry_mwt {
1567 char name[EBT_FUNCTION_MAXNAMELEN];
1570 compat_uint_t match_size;
1571 compat_uint_t data[0];
1574 /* account for possible padding between match_size and ->data */
1575 static int ebt_compat_entry_padsize(void)
1577 BUILD_BUG_ON(XT_ALIGN(sizeof(struct ebt_entry_match)) <
1578 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt)));
1579 return (int) XT_ALIGN(sizeof(struct ebt_entry_match)) -
1580 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt));
1583 static int ebt_compat_match_offset(const struct xt_match *match,
1584 unsigned int userlen)
1586 /* ebt_among needs special handling. The kernel .matchsize is
1587 * set to -1 at registration time; at runtime an EBT_ALIGN()ed
1588 * value is expected.
1589 * Example: userspace sends 4500, ebt_among.c wants 4504.
1591 if (unlikely(match->matchsize == -1))
1592 return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
1593 return xt_compat_match_offset(match);
1596 static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
1599 const struct xt_match *match = m->u.match;
1600 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1601 int off = ebt_compat_match_offset(match, m->match_size);
1602 compat_uint_t msize = m->match_size - off;
1604 if (WARN_ON(off >= m->match_size))
1607 if (copy_to_user(cm->u.name, match->name,
1608 strlen(match->name) + 1) || put_user(msize, &cm->match_size))
1611 if (match->compat_to_user) {
1612 if (match->compat_to_user(cm->data, m->data))
1615 if (xt_data_to_user(cm->data, m->data, match->usersize, msize,
1616 COMPAT_XT_ALIGN(msize)))
1620 *size -= ebt_compat_entry_padsize() + off;
1626 static int compat_target_to_user(struct ebt_entry_target *t,
1627 void __user **dstptr,
1630 const struct xt_target *target = t->u.target;
1631 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1632 int off = xt_compat_target_offset(target);
1633 compat_uint_t tsize = t->target_size - off;
1635 if (WARN_ON(off >= t->target_size))
1638 if (copy_to_user(cm->u.name, target->name,
1639 strlen(target->name) + 1) || put_user(tsize, &cm->match_size))
1642 if (target->compat_to_user) {
1643 if (target->compat_to_user(cm->data, t->data))
1646 if (xt_data_to_user(cm->data, t->data, target->usersize, tsize,
1647 COMPAT_XT_ALIGN(tsize)))
1651 *size -= ebt_compat_entry_padsize() + off;
1657 static int compat_watcher_to_user(struct ebt_entry_watcher *w,
1658 void __user **dstptr,
1661 return compat_target_to_user((struct ebt_entry_target *)w,
1665 static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
1668 struct ebt_entry_target *t;
1669 struct ebt_entry __user *ce;
1670 u32 watchers_offset, target_offset, next_offset;
1671 compat_uint_t origsize;
1674 if (e->bitmask == 0) {
1675 if (*size < sizeof(struct ebt_entries))
1677 if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries)))
1680 *dstptr += sizeof(struct ebt_entries);
1681 *size -= sizeof(struct ebt_entries);
1685 if (*size < sizeof(*ce))
1689 if (copy_to_user(ce, e, sizeof(*ce)))
1693 *dstptr += sizeof(*ce);
1695 ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
1698 watchers_offset = e->watchers_offset - (origsize - *size);
1700 ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
1703 target_offset = e->target_offset - (origsize - *size);
1705 t = (struct ebt_entry_target *) ((char *) e + e->target_offset);
1707 ret = compat_target_to_user(t, dstptr, size);
1710 next_offset = e->next_offset - (origsize - *size);
1712 if (put_user(watchers_offset, &ce->watchers_offset) ||
1713 put_user(target_offset, &ce->target_offset) ||
1714 put_user(next_offset, &ce->next_offset))
1717 *size -= sizeof(*ce);
1721 static int compat_calc_match(struct ebt_entry_match *m, int *off)
1723 *off += ebt_compat_match_offset(m->u.match, m->match_size);
1724 *off += ebt_compat_entry_padsize();
1728 static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
1730 *off += xt_compat_target_offset(w->u.watcher);
1731 *off += ebt_compat_entry_padsize();
1735 static int compat_calc_entry(const struct ebt_entry *e,
1736 const struct ebt_table_info *info,
1738 struct compat_ebt_replace *newinfo)
1740 const struct ebt_entry_target *t;
1741 unsigned int entry_offset;
1744 if (e->bitmask == 0)
1748 entry_offset = (void *)e - base;
1750 EBT_MATCH_ITERATE(e, compat_calc_match, &off);
1751 EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
1753 t = (const struct ebt_entry_target *) ((char *) e + e->target_offset);
1755 off += xt_compat_target_offset(t->u.target);
1756 off += ebt_compat_entry_padsize();
1758 newinfo->entries_size -= off;
1760 ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off);
1764 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1765 const void *hookptr = info->hook_entry[i];
1766 if (info->hook_entry[i] &&
1767 (e < (struct ebt_entry *)(base - hookptr))) {
1768 newinfo->hook_entry[i] -= off;
1769 pr_debug("0x%08X -> 0x%08X\n",
1770 newinfo->hook_entry[i] + off,
1771 newinfo->hook_entry[i]);
1778 static int ebt_compat_init_offsets(unsigned int number)
1780 if (number > INT_MAX)
1783 /* also count the base chain policies */
1784 number += NF_BR_NUMHOOKS;
1786 return xt_compat_init_offsets(NFPROTO_BRIDGE, number);
1789 static int compat_table_info(const struct ebt_table_info *info,
1790 struct compat_ebt_replace *newinfo)
1792 unsigned int size = info->entries_size;
1793 const void *entries = info->entries;
1796 newinfo->entries_size = size;
1797 ret = ebt_compat_init_offsets(info->nentries);
1801 return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
1805 static int compat_copy_everything_to_user(struct ebt_table *t,
1806 void __user *user, int *len, int cmd)
1808 struct compat_ebt_replace repl, tmp;
1809 struct ebt_counter *oldcounters;
1810 struct ebt_table_info tinfo;
1814 memset(&tinfo, 0, sizeof(tinfo));
1816 if (cmd == EBT_SO_GET_ENTRIES) {
1817 tinfo.entries_size = t->private->entries_size;
1818 tinfo.nentries = t->private->nentries;
1819 tinfo.entries = t->private->entries;
1820 oldcounters = t->private->counters;
1822 tinfo.entries_size = t->table->entries_size;
1823 tinfo.nentries = t->table->nentries;
1824 tinfo.entries = t->table->entries;
1825 oldcounters = t->table->counters;
1828 if (copy_from_user(&tmp, user, sizeof(tmp)))
1831 if (tmp.nentries != tinfo.nentries ||
1832 (tmp.num_counters && tmp.num_counters != tinfo.nentries))
1835 memcpy(&repl, &tmp, sizeof(repl));
1836 if (cmd == EBT_SO_GET_ENTRIES)
1837 ret = compat_table_info(t->private, &repl);
1839 ret = compat_table_info(&tinfo, &repl);
1843 if (*len != sizeof(tmp) + repl.entries_size +
1844 (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
1845 pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
1846 *len, tinfo.entries_size, repl.entries_size);
1850 /* userspace might not need the counters */
1851 ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters),
1852 tmp.num_counters, tinfo.nentries);
1856 pos = compat_ptr(tmp.entries);
1857 return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
1858 compat_copy_entry_to_user, &pos, &tmp.entries_size);
1861 struct ebt_entries_buf_state {
1862 char *buf_kern_start; /* kernel buffer to copy (translated) data to */
1863 u32 buf_kern_len; /* total size of kernel buffer */
1864 u32 buf_kern_offset; /* amount of data copied so far */
1865 u32 buf_user_offset; /* read position in userspace buffer */
1868 static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
1870 state->buf_kern_offset += sz;
1871 return state->buf_kern_offset >= sz ? 0 : -EINVAL;
1874 static int ebt_buf_add(struct ebt_entries_buf_state *state,
1875 const void *data, unsigned int sz)
1877 if (state->buf_kern_start == NULL)
1880 if (WARN_ON(state->buf_kern_offset + sz > state->buf_kern_len))
1883 memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz);
1886 state->buf_user_offset += sz;
1887 return ebt_buf_count(state, sz);
1890 static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz)
1892 char *b = state->buf_kern_start;
1894 if (WARN_ON(b && state->buf_kern_offset > state->buf_kern_len))
1897 if (b != NULL && sz > 0)
1898 memset(b + state->buf_kern_offset, 0, sz);
1899 /* do not adjust ->buf_user_offset here, we added kernel-side padding */
1900 return ebt_buf_count(state, sz);
1909 static int compat_mtw_from_user(const struct compat_ebt_entry_mwt *mwt,
1910 enum compat_mwt compat_mwt,
1911 struct ebt_entries_buf_state *state,
1912 const unsigned char *base)
1914 char name[EBT_FUNCTION_MAXNAMELEN];
1915 struct xt_match *match;
1916 struct xt_target *wt;
1919 unsigned int size_kern, match_size = mwt->match_size;
1921 if (strscpy(name, mwt->u.name, sizeof(name)) < 0)
1924 if (state->buf_kern_start)
1925 dst = state->buf_kern_start + state->buf_kern_offset;
1927 switch (compat_mwt) {
1928 case EBT_COMPAT_MATCH:
1929 match = xt_request_find_match(NFPROTO_BRIDGE, name, 0);
1931 return PTR_ERR(match);
1933 off = ebt_compat_match_offset(match, match_size);
1935 if (match->compat_from_user)
1936 match->compat_from_user(dst, mwt->data);
1938 memcpy(dst, mwt->data, match_size);
1941 size_kern = match->matchsize;
1942 if (unlikely(size_kern == -1))
1943 size_kern = match_size;
1944 module_put(match->me);
1946 case EBT_COMPAT_WATCHER: /* fallthrough */
1947 case EBT_COMPAT_TARGET:
1948 wt = xt_request_find_target(NFPROTO_BRIDGE, name, 0);
1951 off = xt_compat_target_offset(wt);
1954 if (wt->compat_from_user)
1955 wt->compat_from_user(dst, mwt->data);
1957 memcpy(dst, mwt->data, match_size);
1960 size_kern = wt->targetsize;
1968 state->buf_kern_offset += match_size + off;
1969 state->buf_user_offset += match_size;
1970 pad = XT_ALIGN(size_kern) - size_kern;
1972 if (pad > 0 && dst) {
1973 if (WARN_ON(state->buf_kern_len <= pad))
1975 if (WARN_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad))
1977 memset(dst + size_kern, 0, pad);
1979 return off + match_size;
1982 /* return size of all matches, watchers or target, including necessary
1983 * alignment and padding.
1985 static int ebt_size_mwt(const struct compat_ebt_entry_mwt *match32,
1986 unsigned int size_left, enum compat_mwt type,
1987 struct ebt_entries_buf_state *state, const void *base)
1989 const char *buf = (const char *)match32;
1996 struct ebt_entry_match *match_kern;
1999 if (size_left < sizeof(*match32))
2002 match_kern = (struct ebt_entry_match *) state->buf_kern_start;
2005 tmp = state->buf_kern_start + state->buf_kern_offset;
2006 match_kern = (struct ebt_entry_match *) tmp;
2008 ret = ebt_buf_add(state, buf, sizeof(*match32));
2011 size_left -= sizeof(*match32);
2013 /* add padding before match->data (if any) */
2014 ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize());
2018 if (match32->match_size > size_left)
2021 size_left -= match32->match_size;
2023 ret = compat_mtw_from_user(match32, type, state, base);
2027 if (WARN_ON(ret < match32->match_size))
2029 growth += ret - match32->match_size;
2030 growth += ebt_compat_entry_padsize();
2032 buf += sizeof(*match32);
2033 buf += match32->match_size;
2036 match_kern->match_size = ret;
2038 match32 = (struct compat_ebt_entry_mwt *) buf;
2039 } while (size_left);
2044 /* called for all ebt_entry structures. */
2045 static int size_entry_mwt(const struct ebt_entry *entry, const unsigned char *base,
2046 unsigned int *total,
2047 struct ebt_entries_buf_state *state)
2049 unsigned int i, j, startoff, next_expected_off, new_offset = 0;
2050 /* stores match/watchers/targets & offset of next struct ebt_entry: */
2051 unsigned int offsets[4];
2052 unsigned int *offsets_update = NULL;
2056 if (*total < sizeof(struct ebt_entries))
2059 if (!entry->bitmask) {
2060 *total -= sizeof(struct ebt_entries);
2061 return ebt_buf_add(state, entry, sizeof(struct ebt_entries));
2063 if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
2066 startoff = state->buf_user_offset;
2067 /* pull in most part of ebt_entry, it does not need to be changed. */
2068 ret = ebt_buf_add(state, entry,
2069 offsetof(struct ebt_entry, watchers_offset));
2073 offsets[0] = sizeof(struct ebt_entry); /* matches come first */
2074 memcpy(&offsets[1], &entry->watchers_offset,
2075 sizeof(offsets) - sizeof(offsets[0]));
2077 if (state->buf_kern_start) {
2078 buf_start = state->buf_kern_start + state->buf_kern_offset;
2079 offsets_update = (unsigned int *) buf_start;
2081 ret = ebt_buf_add(state, &offsets[1],
2082 sizeof(offsets) - sizeof(offsets[0]));
2085 buf_start = (char *) entry;
2086 /* 0: matches offset, always follows ebt_entry.
2087 * 1: watchers offset, from ebt_entry structure
2088 * 2: target offset, from ebt_entry structure
2089 * 3: next ebt_entry offset, from ebt_entry structure
2091 * offsets are relative to beginning of struct ebt_entry (i.e., 0).
2093 for (i = 0; i < 4 ; ++i) {
2094 if (offsets[i] > *total)
2097 if (i < 3 && offsets[i] == *total)
2102 if (offsets[i-1] > offsets[i])
2106 for (i = 0, j = 1 ; j < 4 ; j++, i++) {
2107 struct compat_ebt_entry_mwt *match32;
2109 char *buf = buf_start;
2111 buf = buf_start + offsets[i];
2112 if (offsets[i] > offsets[j])
2115 match32 = (struct compat_ebt_entry_mwt *) buf;
2116 size = offsets[j] - offsets[i];
2117 ret = ebt_size_mwt(match32, size, i, state, base);
2121 if (offsets_update && new_offset) {
2122 pr_debug("change offset %d to %d\n",
2123 offsets_update[i], offsets[j] + new_offset);
2124 offsets_update[i] = offsets[j] + new_offset;
2128 if (state->buf_kern_start == NULL) {
2129 unsigned int offset = buf_start - (char *) base;
2131 ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);
2136 next_expected_off = state->buf_user_offset - startoff;
2137 if (next_expected_off != entry->next_offset)
2140 if (*total < entry->next_offset)
2142 *total -= entry->next_offset;
2146 /* repl->entries_size is the size of the ebt_entry blob in userspace.
2147 * It might need more memory when copied to a 64 bit kernel in case
2148 * userspace is 32-bit. So, first task: find out how much memory is needed.
2150 * Called before validation is performed.
2152 static int compat_copy_entries(unsigned char *data, unsigned int size_user,
2153 struct ebt_entries_buf_state *state)
2155 unsigned int size_remaining = size_user;
2158 ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
2159 &size_remaining, state);
2166 return state->buf_kern_offset;
2170 static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
2171 void __user *user, unsigned int len)
2173 struct compat_ebt_replace tmp;
2176 if (len < sizeof(tmp))
2179 if (copy_from_user(&tmp, user, sizeof(tmp)))
2182 if (len != sizeof(tmp) + tmp.entries_size)
2185 if (tmp.entries_size == 0)
2188 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
2189 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
2191 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
2194 memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
2196 /* starting with hook_entry, 32 vs. 64 bit structures are different */
2197 for (i = 0; i < NF_BR_NUMHOOKS; i++)
2198 repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]);
2200 repl->num_counters = tmp.num_counters;
2201 repl->counters = compat_ptr(tmp.counters);
2202 repl->entries = compat_ptr(tmp.entries);
2206 static int compat_do_replace(struct net *net, void __user *user,
2209 int ret, i, countersize, size64;
2210 struct ebt_table_info *newinfo;
2211 struct ebt_replace tmp;
2212 struct ebt_entries_buf_state state;
2215 ret = compat_copy_ebt_replace_from_user(&tmp, user, len);
2217 /* try real handler in case userland supplied needed padding */
2218 if (ret == -EINVAL && do_replace(net, user, len) == 0)
2223 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
2224 newinfo = vmalloc(sizeof(*newinfo) + countersize);
2229 memset(newinfo->counters, 0, countersize);
2231 memset(&state, 0, sizeof(state));
2233 newinfo->entries = vmalloc(tmp.entries_size);
2234 if (!newinfo->entries) {
2239 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
2244 entries_tmp = newinfo->entries;
2246 xt_compat_lock(NFPROTO_BRIDGE);
2248 ret = ebt_compat_init_offsets(tmp.nentries);
2252 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2256 pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
2257 tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
2258 xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
2261 newinfo->entries = vmalloc(size64);
2262 if (!newinfo->entries) {
2268 memset(&state, 0, sizeof(state));
2269 state.buf_kern_start = newinfo->entries;
2270 state.buf_kern_len = size64;
2272 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2273 if (WARN_ON(ret < 0)) {
2279 tmp.entries_size = size64;
2281 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
2282 char __user *usrptr;
2283 if (tmp.hook_entry[i]) {
2285 usrptr = (char __user *) tmp.hook_entry[i];
2286 delta = usrptr - tmp.entries;
2287 usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta);
2288 tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
2292 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2293 xt_compat_unlock(NFPROTO_BRIDGE);
2295 ret = do_replace_finish(net, &tmp, newinfo);
2299 vfree(newinfo->entries);
2304 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2305 xt_compat_unlock(NFPROTO_BRIDGE);
2309 static int compat_update_counters(struct net *net, void __user *user,
2312 struct compat_ebt_replace hlp;
2314 if (copy_from_user(&hlp, user, sizeof(hlp)))
2317 /* try real handler in case userland supplied needed padding */
2318 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
2319 return update_counters(net, user, len);
2321 return do_update_counters(net, hlp.name, compat_ptr(hlp.counters),
2322 hlp.num_counters, user, len);
2325 static int compat_do_ebt_set_ctl(struct sock *sk,
2326 int cmd, void __user *user, unsigned int len)
2329 struct net *net = sock_net(sk);
2331 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2335 case EBT_SO_SET_ENTRIES:
2336 ret = compat_do_replace(net, user, len);
2338 case EBT_SO_SET_COUNTERS:
2339 ret = compat_update_counters(net, user, len);
2347 static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
2348 void __user *user, int *len)
2351 struct compat_ebt_replace tmp;
2352 struct ebt_table *t;
2353 struct net *net = sock_net(sk);
2355 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2358 /* try real handler in case userland supplied needed padding */
2359 if ((cmd == EBT_SO_GET_INFO ||
2360 cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp))
2361 return do_ebt_get_ctl(sk, cmd, user, len);
2363 if (copy_from_user(&tmp, user, sizeof(tmp)))
2366 tmp.name[sizeof(tmp.name) - 1] = '\0';
2368 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
2372 xt_compat_lock(NFPROTO_BRIDGE);
2374 case EBT_SO_GET_INFO:
2375 tmp.nentries = t->private->nentries;
2376 ret = compat_table_info(t->private, &tmp);
2379 tmp.valid_hooks = t->valid_hooks;
2381 if (copy_to_user(user, &tmp, *len) != 0) {
2387 case EBT_SO_GET_INIT_INFO:
2388 tmp.nentries = t->table->nentries;
2389 tmp.entries_size = t->table->entries_size;
2390 tmp.valid_hooks = t->table->valid_hooks;
2392 if (copy_to_user(user, &tmp, *len) != 0) {
2398 case EBT_SO_GET_ENTRIES:
2399 case EBT_SO_GET_INIT_ENTRIES:
2400 /* try real handler first in case of userland-side padding.
2401 * in case we are dealing with an 'ordinary' 32 bit binary
2402 * without 64bit compatibility padding, this will fail right
2403 * after copy_from_user when the *len argument is validated.
2405 * the compat_ variant needs to do one pass over the kernel
2406 * data set to adjust for size differences before it the check.
2408 if (copy_everything_to_user(t, user, len, cmd) == 0)
2411 ret = compat_copy_everything_to_user(t, user, len, cmd);
2417 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2418 xt_compat_unlock(NFPROTO_BRIDGE);
2419 mutex_unlock(&ebt_mutex);
2424 static struct nf_sockopt_ops ebt_sockopts = {
2426 .set_optmin = EBT_BASE_CTL,
2427 .set_optmax = EBT_SO_SET_MAX + 1,
2428 .set = do_ebt_set_ctl,
2429 #ifdef CONFIG_COMPAT
2430 .compat_set = compat_do_ebt_set_ctl,
2432 .get_optmin = EBT_BASE_CTL,
2433 .get_optmax = EBT_SO_GET_MAX + 1,
2434 .get = do_ebt_get_ctl,
2435 #ifdef CONFIG_COMPAT
2436 .compat_get = compat_do_ebt_get_ctl,
2438 .owner = THIS_MODULE,
2441 static int __init ebtables_init(void)
2445 ret = xt_register_target(&ebt_standard_target);
2448 ret = nf_register_sockopt(&ebt_sockopts);
2450 xt_unregister_target(&ebt_standard_target);
2454 printk(KERN_INFO "Ebtables v2.0 registered\n");
2458 static void __exit ebtables_fini(void)
2460 nf_unregister_sockopt(&ebt_sockopts);
2461 xt_unregister_target(&ebt_standard_target);
2462 printk(KERN_INFO "Ebtables v2.0 unregistered\n");
2465 EXPORT_SYMBOL(ebt_register_table);
2466 EXPORT_SYMBOL(ebt_unregister_table);
2467 EXPORT_SYMBOL(ebt_do_table);
2468 module_init(ebtables_init);
2469 module_exit(ebtables_fini);
2470 MODULE_LICENSE("GPL");