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 <asm/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_slow */
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;
197 acpar.family = NFPROTO_BRIDGE;
198 acpar.net = state->net;
199 acpar.in = state->in;
200 acpar.out = state->out;
201 acpar.hotdrop = false;
202 acpar.hooknum = hook;
204 read_lock_bh(&table->lock);
205 private = table->private;
206 cb_base = COUNTER_BASE(private->counters, private->nentries,
208 if (private->chainstack)
209 cs = private->chainstack[smp_processor_id()];
212 chaininfo = private->hook_entry[hook];
213 nentries = private->hook_entry[hook]->nentries;
214 point = (struct ebt_entry *)(private->hook_entry[hook]->data);
215 counter_base = cb_base + private->hook_entry[hook]->counter_offset;
216 /* base for chain jumps */
217 base = private->entries;
219 while (i < nentries) {
220 if (ebt_basic_match(point, skb, state->in, state->out))
223 if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0)
226 read_unlock_bh(&table->lock);
230 /* increase counter */
231 (*(counter_base + i)).pcnt++;
232 (*(counter_base + i)).bcnt += skb->len;
234 /* these should only watch: not modify, nor tell us
235 * what to do with the packet
237 EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar);
239 t = (struct ebt_entry_target *)
240 (((char *)point) + point->target_offset);
241 /* standard target */
242 if (!t->u.target->target)
243 verdict = ((struct ebt_standard_target *)t)->verdict;
245 acpar.target = t->u.target;
246 acpar.targinfo = t->data;
247 verdict = t->u.target->target(skb, &acpar);
249 if (verdict == EBT_ACCEPT) {
250 read_unlock_bh(&table->lock);
253 if (verdict == EBT_DROP) {
254 read_unlock_bh(&table->lock);
257 if (verdict == EBT_RETURN) {
259 #ifdef CONFIG_NETFILTER_DEBUG
261 BUGPRINT("RETURN on base chain");
262 /* act like this is EBT_CONTINUE */
267 /* put all the local variables right */
269 chaininfo = cs[sp].chaininfo;
270 nentries = chaininfo->nentries;
272 counter_base = cb_base +
273 chaininfo->counter_offset;
276 if (verdict == EBT_CONTINUE)
278 #ifdef CONFIG_NETFILTER_DEBUG
280 BUGPRINT("bogus standard verdict\n");
281 read_unlock_bh(&table->lock);
287 cs[sp].chaininfo = chaininfo;
288 cs[sp].e = ebt_next_entry(point);
290 chaininfo = (struct ebt_entries *) (base + verdict);
291 #ifdef CONFIG_NETFILTER_DEBUG
292 if (chaininfo->distinguisher) {
293 BUGPRINT("jump to non-chain\n");
294 read_unlock_bh(&table->lock);
298 nentries = chaininfo->nentries;
299 point = (struct ebt_entry *)chaininfo->data;
300 counter_base = cb_base + chaininfo->counter_offset;
304 point = ebt_next_entry(point);
308 /* I actually like this :) */
309 if (chaininfo->policy == EBT_RETURN)
311 if (chaininfo->policy == EBT_ACCEPT) {
312 read_unlock_bh(&table->lock);
315 read_unlock_bh(&table->lock);
319 /* If it succeeds, returns element and locks mutex */
321 find_inlist_lock_noload(struct list_head *head, const char *name, int *error,
325 struct list_head list;
326 char name[EBT_FUNCTION_MAXNAMELEN];
330 list_for_each_entry(e, head, list) {
331 if (strcmp(e->name, name) == 0)
340 find_inlist_lock(struct list_head *head, const char *name, const char *prefix,
341 int *error, struct mutex *mutex)
343 return try_then_request_module(
344 find_inlist_lock_noload(head, name, error, mutex),
345 "%s%s", prefix, name);
348 static inline struct ebt_table *
349 find_table_lock(struct net *net, const char *name, int *error,
352 return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name,
353 "ebtable_", error, mutex);
357 ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
360 const struct ebt_entry *e = par->entryinfo;
361 struct xt_match *match;
362 size_t left = ((char *)e + e->watchers_offset) - (char *)m;
365 if (left < sizeof(struct ebt_entry_match) ||
366 left - sizeof(struct ebt_entry_match) < m->match_size)
369 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, 0);
370 if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) {
372 module_put(match->me);
373 request_module("ebt_%s", m->u.name);
374 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, 0);
377 return PTR_ERR(match);
381 par->matchinfo = m->data;
382 ret = xt_check_match(par, m->match_size,
383 e->ethproto, e->invflags & EBT_IPROTO);
385 module_put(match->me);
394 ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
397 const struct ebt_entry *e = par->entryinfo;
398 struct xt_target *watcher;
399 size_t left = ((char *)e + e->target_offset) - (char *)w;
402 if (left < sizeof(struct ebt_entry_watcher) ||
403 left - sizeof(struct ebt_entry_watcher) < w->watcher_size)
406 watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0);
408 return PTR_ERR(watcher);
409 w->u.watcher = watcher;
411 par->target = watcher;
412 par->targinfo = w->data;
413 ret = xt_check_target(par, w->watcher_size,
414 e->ethproto, e->invflags & EBT_IPROTO);
416 module_put(watcher->me);
424 static int ebt_verify_pointers(const struct ebt_replace *repl,
425 struct ebt_table_info *newinfo)
427 unsigned int limit = repl->entries_size;
428 unsigned int valid_hooks = repl->valid_hooks;
429 unsigned int offset = 0;
432 for (i = 0; i < NF_BR_NUMHOOKS; i++)
433 newinfo->hook_entry[i] = NULL;
435 newinfo->entries_size = repl->entries_size;
436 newinfo->nentries = repl->nentries;
438 while (offset < limit) {
439 size_t left = limit - offset;
440 struct ebt_entry *e = (void *)newinfo->entries + offset;
442 if (left < sizeof(unsigned int))
445 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
446 if ((valid_hooks & (1 << i)) == 0)
448 if ((char __user *)repl->hook_entry[i] ==
449 repl->entries + offset)
453 if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
454 if (e->bitmask != 0) {
455 /* we make userspace set this right,
456 * so there is no misunderstanding
458 BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set "
459 "in distinguisher\n");
462 if (i != NF_BR_NUMHOOKS)
463 newinfo->hook_entry[i] = (struct ebt_entries *)e;
464 if (left < sizeof(struct ebt_entries))
466 offset += sizeof(struct ebt_entries);
468 if (left < sizeof(struct ebt_entry))
470 if (left < e->next_offset)
472 if (e->next_offset < sizeof(struct ebt_entry))
474 offset += e->next_offset;
477 if (offset != limit) {
478 BUGPRINT("entries_size too small\n");
482 /* check if all valid hooks have a chain */
483 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
484 if (!newinfo->hook_entry[i] &&
485 (valid_hooks & (1 << i))) {
486 BUGPRINT("Valid hook without chain\n");
493 /* this one is very careful, as it is the first function
494 * to parse the userspace data
497 ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
498 const struct ebt_table_info *newinfo,
499 unsigned int *n, unsigned int *cnt,
500 unsigned int *totalcnt, unsigned int *udc_cnt)
504 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
505 if ((void *)e == (void *)newinfo->hook_entry[i])
508 /* beginning of a new chain
509 * if i == NF_BR_NUMHOOKS it must be a user defined chain
511 if (i != NF_BR_NUMHOOKS || !e->bitmask) {
512 /* this checks if the previous chain has as many entries
516 BUGPRINT("nentries does not equal the nr of entries "
520 if (((struct ebt_entries *)e)->policy != EBT_DROP &&
521 ((struct ebt_entries *)e)->policy != EBT_ACCEPT) {
522 /* only RETURN from udc */
523 if (i != NF_BR_NUMHOOKS ||
524 ((struct ebt_entries *)e)->policy != EBT_RETURN) {
525 BUGPRINT("bad policy\n");
529 if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */
531 if (((struct ebt_entries *)e)->counter_offset != *totalcnt) {
532 BUGPRINT("counter_offset != totalcnt");
535 *n = ((struct ebt_entries *)e)->nentries;
539 /* a plain old entry, heh */
540 if (sizeof(struct ebt_entry) > e->watchers_offset ||
541 e->watchers_offset > e->target_offset ||
542 e->target_offset >= e->next_offset) {
543 BUGPRINT("entry offsets not in right order\n");
546 /* this is not checked anywhere else */
547 if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target)) {
548 BUGPRINT("target size too small\n");
556 struct ebt_cl_stack {
557 struct ebt_chainstack cs;
559 unsigned int hookmask;
562 /* We need these positions to check that the jumps to a different part of the
563 * entries is a jump to the beginning of a new chain.
566 ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo,
567 unsigned int *n, struct ebt_cl_stack *udc)
571 /* we're only interested in chain starts */
574 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
575 if (newinfo->hook_entry[i] == (struct ebt_entries *)e)
578 /* only care about udc */
579 if (i != NF_BR_NUMHOOKS)
582 udc[*n].cs.chaininfo = (struct ebt_entries *)e;
583 /* these initialisations are depended on later in check_chainloops() */
585 udc[*n].hookmask = 0;
592 ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i)
594 struct xt_mtdtor_param par;
596 if (i && (*i)-- == 0)
600 par.match = m->u.match;
601 par.matchinfo = m->data;
602 par.family = NFPROTO_BRIDGE;
603 if (par.match->destroy != NULL)
604 par.match->destroy(&par);
605 module_put(par.match->me);
610 ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i)
612 struct xt_tgdtor_param par;
614 if (i && (*i)-- == 0)
618 par.target = w->u.watcher;
619 par.targinfo = w->data;
620 par.family = NFPROTO_BRIDGE;
621 if (par.target->destroy != NULL)
622 par.target->destroy(&par);
623 module_put(par.target->me);
628 ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
630 struct xt_tgdtor_param par;
631 struct ebt_entry_target *t;
636 if (cnt && (*cnt)-- == 0)
638 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL);
639 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL);
640 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
643 par.target = t->u.target;
644 par.targinfo = t->data;
645 par.family = NFPROTO_BRIDGE;
646 if (par.target->destroy != NULL)
647 par.target->destroy(&par);
648 module_put(par.target->me);
653 ebt_check_entry(struct ebt_entry *e, struct net *net,
654 const struct ebt_table_info *newinfo,
655 const char *name, unsigned int *cnt,
656 struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
658 struct ebt_entry_target *t;
659 struct xt_target *target;
660 unsigned int i, j, hook = 0, hookmask = 0;
663 struct xt_mtchk_param mtpar;
664 struct xt_tgchk_param tgpar;
666 /* don't mess with the struct ebt_entries */
670 if (e->bitmask & ~EBT_F_MASK) {
671 BUGPRINT("Unknown flag for bitmask\n");
674 if (e->invflags & ~EBT_INV_MASK) {
675 BUGPRINT("Unknown flag for inv bitmask\n");
678 if ((e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3)) {
679 BUGPRINT("NOPROTO & 802_3 not allowed\n");
682 /* what hook do we belong to? */
683 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
684 if (!newinfo->hook_entry[i])
686 if ((char *)newinfo->hook_entry[i] < (char *)e)
691 /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on
694 if (i < NF_BR_NUMHOOKS)
695 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
697 for (i = 0; i < udc_cnt; i++)
698 if ((char *)(cl_s[i].cs.chaininfo) > (char *)e)
701 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
703 hookmask = cl_s[i - 1].hookmask;
707 mtpar.net = tgpar.net = net;
708 mtpar.table = tgpar.table = name;
709 mtpar.entryinfo = tgpar.entryinfo = e;
710 mtpar.hook_mask = tgpar.hook_mask = hookmask;
711 mtpar.family = tgpar.family = NFPROTO_BRIDGE;
712 ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i);
714 goto cleanup_matches;
716 ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j);
718 goto cleanup_watchers;
719 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
720 gap = e->next_offset - e->target_offset;
722 target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0);
723 if (IS_ERR(target)) {
724 ret = PTR_ERR(target);
725 goto cleanup_watchers;
728 t->u.target = target;
729 if (t->u.target == &ebt_standard_target) {
730 if (gap < sizeof(struct ebt_standard_target)) {
731 BUGPRINT("Standard target size too big\n");
733 goto cleanup_watchers;
735 if (((struct ebt_standard_target *)t)->verdict <
736 -NUM_STANDARD_TARGETS) {
737 BUGPRINT("Invalid standard target\n");
739 goto cleanup_watchers;
741 } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) {
742 module_put(t->u.target->me);
744 goto cleanup_watchers;
747 tgpar.target = target;
748 tgpar.targinfo = t->data;
749 ret = xt_check_target(&tgpar, t->target_size,
750 e->ethproto, e->invflags & EBT_IPROTO);
752 module_put(target->me);
753 goto cleanup_watchers;
758 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j);
760 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i);
764 /* checks for loops and sets the hook mask for udc
765 * the hook mask for udc tells us from which base chains the udc can be
766 * accessed. This mask is a parameter to the check() functions of the extensions
768 static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
769 unsigned int udc_cnt, unsigned int hooknr, char *base)
771 int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
772 const struct ebt_entry *e = (struct ebt_entry *)chain->data;
773 const struct ebt_entry_target *t;
775 while (pos < nentries || chain_nr != -1) {
776 /* end of udc, go back one 'recursion' step */
777 if (pos == nentries) {
778 /* put back values of the time when this chain was called */
779 e = cl_s[chain_nr].cs.e;
780 if (cl_s[chain_nr].from != -1)
782 cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries;
784 nentries = chain->nentries;
785 pos = cl_s[chain_nr].cs.n;
786 /* make sure we won't see a loop that isn't one */
787 cl_s[chain_nr].cs.n = 0;
788 chain_nr = cl_s[chain_nr].from;
792 t = (struct ebt_entry_target *)
793 (((char *)e) + e->target_offset);
794 if (strcmp(t->u.name, EBT_STANDARD_TARGET))
796 if (e->target_offset + sizeof(struct ebt_standard_target) >
798 BUGPRINT("Standard target size too big\n");
801 verdict = ((struct ebt_standard_target *)t)->verdict;
802 if (verdict >= 0) { /* jump to another chain */
803 struct ebt_entries *hlp2 =
804 (struct ebt_entries *)(base + verdict);
805 for (i = 0; i < udc_cnt; i++)
806 if (hlp2 == cl_s[i].cs.chaininfo)
808 /* bad destination or loop */
810 BUGPRINT("bad destination\n");
817 if (cl_s[i].hookmask & (1 << hooknr))
819 /* this can't be 0, so the loop test is correct */
820 cl_s[i].cs.n = pos + 1;
822 cl_s[i].cs.e = ebt_next_entry(e);
823 e = (struct ebt_entry *)(hlp2->data);
824 nentries = hlp2->nentries;
825 cl_s[i].from = chain_nr;
827 /* this udc is accessible from the base chain for hooknr */
828 cl_s[i].hookmask |= (1 << hooknr);
832 e = ebt_next_entry(e);
838 /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
839 static int translate_table(struct net *net, const char *name,
840 struct ebt_table_info *newinfo)
842 unsigned int i, j, k, udc_cnt;
844 struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */
847 while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i])
849 if (i == NF_BR_NUMHOOKS) {
850 BUGPRINT("No valid hooks specified\n");
853 if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) {
854 BUGPRINT("Chains don't start at beginning\n");
857 /* make sure chains are ordered after each other in same order
858 * as their corresponding hooks
860 for (j = i + 1; j < NF_BR_NUMHOOKS; j++) {
861 if (!newinfo->hook_entry[j])
863 if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) {
864 BUGPRINT("Hook order must be followed\n");
870 /* do some early checkings and initialize some things */
871 i = 0; /* holds the expected nr. of entries for the chain */
872 j = 0; /* holds the up to now counted entries for the chain */
873 k = 0; /* holds the total nr. of entries, should equal
874 * newinfo->nentries afterwards
876 udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */
877 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
878 ebt_check_entry_size_and_hooks, newinfo,
879 &i, &j, &k, &udc_cnt);
885 BUGPRINT("nentries does not equal the nr of entries in the "
889 if (k != newinfo->nentries) {
890 BUGPRINT("Total nentries is wrong\n");
894 /* get the location of the udc, put them in an array
895 * while we're at it, allocate the chainstack
898 /* this will get free'd in do_replace()/ebt_register_table()
901 newinfo->chainstack =
902 vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack)));
903 if (!newinfo->chainstack)
905 for_each_possible_cpu(i) {
906 newinfo->chainstack[i] =
907 vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0])));
908 if (!newinfo->chainstack[i]) {
910 vfree(newinfo->chainstack[--i]);
911 vfree(newinfo->chainstack);
912 newinfo->chainstack = NULL;
917 cl_s = vmalloc(udc_cnt * sizeof(*cl_s));
920 i = 0; /* the i'th udc */
921 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
922 ebt_get_udc_positions, newinfo, &i, cl_s);
925 BUGPRINT("i != udc_cnt\n");
931 /* Check for loops */
932 for (i = 0; i < NF_BR_NUMHOOKS; i++)
933 if (newinfo->hook_entry[i])
934 if (check_chainloops(newinfo->hook_entry[i],
935 cl_s, udc_cnt, i, newinfo->entries)) {
940 /* we now know the following (along with E=mc²):
941 * - the nr of entries in each chain is right
942 * - the size of the allocated space is right
943 * - all valid hooks have a corresponding chain
944 * - there are no loops
945 * - wrong data can still be on the level of a single entry
946 * - could be there are jumps to places that are not the
947 * beginning of a chain. This can only occur in chains that
948 * are not accessible from any base chains, so we don't care.
951 /* used to know what we need to clean up if something goes wrong */
953 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
954 ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt);
956 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
957 ebt_cleanup_entry, net, &i);
963 /* called under write_lock */
964 static void get_counters(const struct ebt_counter *oldcounters,
965 struct ebt_counter *counters, unsigned int nentries)
968 struct ebt_counter *counter_base;
970 /* counters of cpu 0 */
971 memcpy(counters, oldcounters,
972 sizeof(struct ebt_counter) * nentries);
974 /* add other counters to those of cpu 0 */
975 for_each_possible_cpu(cpu) {
978 counter_base = COUNTER_BASE(oldcounters, nentries, cpu);
979 for (i = 0; i < nentries; i++) {
980 counters[i].pcnt += counter_base[i].pcnt;
981 counters[i].bcnt += counter_base[i].bcnt;
986 static int do_replace_finish(struct net *net, struct ebt_replace *repl,
987 struct ebt_table_info *newinfo)
990 struct ebt_counter *counterstmp = NULL;
991 /* used to be able to unlock earlier */
992 struct ebt_table_info *table;
995 /* the user wants counters back
996 * the check on the size is done later, when we have the lock
998 if (repl->num_counters) {
999 unsigned long size = repl->num_counters * sizeof(*counterstmp);
1000 counterstmp = vmalloc(size);
1005 newinfo->chainstack = NULL;
1006 ret = ebt_verify_pointers(repl, newinfo);
1008 goto free_counterstmp;
1010 ret = translate_table(net, repl->name, newinfo);
1013 goto free_counterstmp;
1015 t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
1021 /* the table doesn't like it */
1022 if (t->check && (ret = t->check(newinfo, repl->valid_hooks)))
1025 if (repl->num_counters && repl->num_counters != t->private->nentries) {
1026 BUGPRINT("Wrong nr. of counters requested\n");
1031 /* we have the mutex lock, so no danger in reading this pointer */
1033 /* make sure the table can only be rmmod'ed if it contains no rules */
1034 if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) {
1037 } else if (table->nentries && !newinfo->nentries)
1039 /* we need an atomic snapshot of the counters */
1040 write_lock_bh(&t->lock);
1041 if (repl->num_counters)
1042 get_counters(t->private->counters, counterstmp,
1043 t->private->nentries);
1045 t->private = newinfo;
1046 write_unlock_bh(&t->lock);
1047 mutex_unlock(&ebt_mutex);
1048 /* so, a user can change the chains while having messed up her counter
1049 * allocation. Only reason why this is done is because this way the lock
1050 * is held only once, while this doesn't bring the kernel into a
1053 if (repl->num_counters &&
1054 copy_to_user(repl->counters, counterstmp,
1055 repl->num_counters * sizeof(struct ebt_counter))) {
1056 /* Silent error, can't fail, new table is already in place */
1057 net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n");
1060 /* decrease module count and free resources */
1061 EBT_ENTRY_ITERATE(table->entries, table->entries_size,
1062 ebt_cleanup_entry, net, NULL);
1064 vfree(table->entries);
1065 if (table->chainstack) {
1066 for_each_possible_cpu(i)
1067 vfree(table->chainstack[i]);
1068 vfree(table->chainstack);
1075 if (audit_enabled) {
1076 struct audit_buffer *ab;
1078 ab = audit_log_start(current->audit_context, GFP_KERNEL,
1079 AUDIT_NETFILTER_CFG);
1081 audit_log_format(ab, "table=%s family=%u entries=%u",
1082 repl->name, AF_BRIDGE, repl->nentries);
1090 mutex_unlock(&ebt_mutex);
1092 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
1093 ebt_cleanup_entry, net, NULL);
1096 /* can be initialized in translate_table() */
1097 if (newinfo->chainstack) {
1098 for_each_possible_cpu(i)
1099 vfree(newinfo->chainstack[i]);
1100 vfree(newinfo->chainstack);
1105 /* replace the table */
1106 static int do_replace(struct net *net, const void __user *user,
1109 int ret, countersize;
1110 struct ebt_table_info *newinfo;
1111 struct ebt_replace tmp;
1113 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1116 if (len != sizeof(tmp) + tmp.entries_size) {
1117 BUGPRINT("Wrong len argument\n");
1121 if (tmp.entries_size == 0) {
1122 BUGPRINT("Entries_size never zero\n");
1125 /* overflow check */
1126 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
1127 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
1129 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
1132 tmp.name[sizeof(tmp.name) - 1] = 0;
1134 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
1135 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1140 memset(newinfo->counters, 0, countersize);
1142 newinfo->entries = vmalloc(tmp.entries_size);
1143 if (!newinfo->entries) {
1148 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
1149 BUGPRINT("Couldn't copy entries from userspace\n");
1154 ret = do_replace_finish(net, &tmp, newinfo);
1158 vfree(newinfo->entries);
1165 ebt_register_table(struct net *net, const struct ebt_table *input_table)
1167 struct ebt_table_info *newinfo;
1168 struct ebt_table *t, *table;
1169 struct ebt_replace_kernel *repl;
1170 int ret, i, countersize;
1173 if (input_table == NULL || (repl = input_table->table) == NULL ||
1174 repl->entries == NULL || repl->entries_size == 0 ||
1175 repl->counters != NULL || input_table->private != NULL) {
1176 BUGPRINT("Bad table data for ebt_register_table!!!\n");
1177 return ERR_PTR(-EINVAL);
1180 /* Don't add one table to multiple lists. */
1181 table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL);
1187 countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
1188 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1193 p = vmalloc(repl->entries_size);
1197 memcpy(p, repl->entries, repl->entries_size);
1198 newinfo->entries = p;
1200 newinfo->entries_size = repl->entries_size;
1201 newinfo->nentries = repl->nentries;
1204 memset(newinfo->counters, 0, countersize);
1206 /* fill in newinfo and parse the entries */
1207 newinfo->chainstack = NULL;
1208 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1209 if ((repl->valid_hooks & (1 << i)) == 0)
1210 newinfo->hook_entry[i] = NULL;
1212 newinfo->hook_entry[i] = p +
1213 ((char *)repl->hook_entry[i] - repl->entries);
1215 ret = translate_table(net, repl->name, newinfo);
1217 BUGPRINT("Translate_table failed\n");
1218 goto free_chainstack;
1221 if (table->check && table->check(newinfo, table->valid_hooks)) {
1222 BUGPRINT("The table doesn't like its own initial data, lol\n");
1224 goto free_chainstack;
1227 table->private = newinfo;
1228 rwlock_init(&table->lock);
1229 mutex_lock(&ebt_mutex);
1230 list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
1231 if (strcmp(t->name, table->name) == 0) {
1233 BUGPRINT("Table name already exists\n");
1238 /* Hold a reference count if the chains aren't empty */
1239 if (newinfo->nentries && !try_module_get(table->me)) {
1243 list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
1244 mutex_unlock(&ebt_mutex);
1247 mutex_unlock(&ebt_mutex);
1249 if (newinfo->chainstack) {
1250 for_each_possible_cpu(i)
1251 vfree(newinfo->chainstack[i]);
1252 vfree(newinfo->chainstack);
1254 vfree(newinfo->entries);
1260 return ERR_PTR(ret);
1263 void ebt_unregister_table(struct net *net, struct ebt_table *table)
1268 BUGPRINT("Request to unregister NULL table!!!\n");
1271 mutex_lock(&ebt_mutex);
1272 list_del(&table->list);
1273 mutex_unlock(&ebt_mutex);
1274 EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
1275 ebt_cleanup_entry, net, NULL);
1276 if (table->private->nentries)
1277 module_put(table->me);
1278 vfree(table->private->entries);
1279 if (table->private->chainstack) {
1280 for_each_possible_cpu(i)
1281 vfree(table->private->chainstack[i]);
1282 vfree(table->private->chainstack);
1284 vfree(table->private);
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 t->private->counters[i].pcnt += tmp[i].pcnt;
1326 t->private->counters[i].bcnt += tmp[i].bcnt;
1329 write_unlock_bh(&t->lock);
1332 mutex_unlock(&ebt_mutex);
1338 static int update_counters(struct net *net, const void __user *user,
1341 struct ebt_replace hlp;
1343 if (copy_from_user(&hlp, user, sizeof(hlp)))
1346 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
1349 return do_update_counters(net, hlp.name, hlp.counters,
1350 hlp.num_counters, user, len);
1353 static inline int ebt_make_matchname(const struct ebt_entry_match *m,
1354 const char *base, char __user *ubase)
1356 char __user *hlp = ubase + ((char *)m - base);
1357 char name[EBT_FUNCTION_MAXNAMELEN] = {};
1359 /* ebtables expects 32 bytes long names but xt_match names are 29 bytes
1360 * long. Copy 29 bytes and fill remaining bytes with zeroes.
1362 strlcpy(name, m->u.match->name, sizeof(name));
1363 if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN))
1368 static inline int ebt_make_watchername(const struct ebt_entry_watcher *w,
1369 const char *base, char __user *ubase)
1371 char __user *hlp = ubase + ((char *)w - base);
1372 char name[EBT_FUNCTION_MAXNAMELEN] = {};
1374 strlcpy(name, w->u.watcher->name, sizeof(name));
1375 if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN))
1380 static inline int ebt_make_names(struct ebt_entry *e, const char *base,
1385 const struct ebt_entry_target *t;
1386 char name[EBT_FUNCTION_MAXNAMELEN] = {};
1388 if (e->bitmask == 0)
1391 hlp = ubase + (((char *)e + e->target_offset) - base);
1392 t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
1394 ret = EBT_MATCH_ITERATE(e, ebt_make_matchname, base, ubase);
1397 ret = EBT_WATCHER_ITERATE(e, ebt_make_watchername, base, ubase);
1400 strlcpy(name, t->u.target->name, sizeof(name));
1401 if (copy_to_user(hlp, name, EBT_FUNCTION_MAXNAMELEN))
1406 static int copy_counters_to_user(struct ebt_table *t,
1407 const struct ebt_counter *oldcounters,
1408 void __user *user, unsigned int num_counters,
1409 unsigned int nentries)
1411 struct ebt_counter *counterstmp;
1414 /* userspace might not need the counters */
1415 if (num_counters == 0)
1418 if (num_counters != nentries) {
1419 BUGPRINT("Num_counters wrong\n");
1423 counterstmp = vmalloc(nentries * sizeof(*counterstmp));
1427 write_lock_bh(&t->lock);
1428 get_counters(oldcounters, counterstmp, nentries);
1429 write_unlock_bh(&t->lock);
1431 if (copy_to_user(user, counterstmp,
1432 nentries * sizeof(struct ebt_counter)))
1438 /* called with ebt_mutex locked */
1439 static int copy_everything_to_user(struct ebt_table *t, void __user *user,
1440 const int *len, int cmd)
1442 struct ebt_replace tmp;
1443 const struct ebt_counter *oldcounters;
1444 unsigned int entries_size, nentries;
1448 if (cmd == EBT_SO_GET_ENTRIES) {
1449 entries_size = t->private->entries_size;
1450 nentries = t->private->nentries;
1451 entries = t->private->entries;
1452 oldcounters = t->private->counters;
1454 entries_size = t->table->entries_size;
1455 nentries = t->table->nentries;
1456 entries = t->table->entries;
1457 oldcounters = t->table->counters;
1460 if (copy_from_user(&tmp, user, sizeof(tmp)))
1463 if (*len != sizeof(struct ebt_replace) + entries_size +
1464 (tmp.num_counters ? nentries * sizeof(struct ebt_counter) : 0))
1467 if (tmp.nentries != nentries) {
1468 BUGPRINT("Nentries wrong\n");
1472 if (tmp.entries_size != entries_size) {
1473 BUGPRINT("Wrong size\n");
1477 ret = copy_counters_to_user(t, oldcounters, tmp.counters,
1478 tmp.num_counters, nentries);
1482 if (copy_to_user(tmp.entries, entries, entries_size)) {
1483 BUGPRINT("Couldn't copy entries to userspace\n");
1486 /* set the match/watcher/target names right */
1487 return EBT_ENTRY_ITERATE(entries, entries_size,
1488 ebt_make_names, entries, tmp.entries);
1491 static int do_ebt_set_ctl(struct sock *sk,
1492 int cmd, void __user *user, unsigned int len)
1495 struct net *net = sock_net(sk);
1497 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1501 case EBT_SO_SET_ENTRIES:
1502 ret = do_replace(net, user, len);
1504 case EBT_SO_SET_COUNTERS:
1505 ret = update_counters(net, user, len);
1513 static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1516 struct ebt_replace tmp;
1517 struct ebt_table *t;
1518 struct net *net = sock_net(sk);
1520 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1523 if (copy_from_user(&tmp, user, sizeof(tmp)))
1526 tmp.name[sizeof(tmp.name) - 1] = '\0';
1528 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
1533 case EBT_SO_GET_INFO:
1534 case EBT_SO_GET_INIT_INFO:
1535 if (*len != sizeof(struct ebt_replace)) {
1537 mutex_unlock(&ebt_mutex);
1540 if (cmd == EBT_SO_GET_INFO) {
1541 tmp.nentries = t->private->nentries;
1542 tmp.entries_size = t->private->entries_size;
1543 tmp.valid_hooks = t->valid_hooks;
1545 tmp.nentries = t->table->nentries;
1546 tmp.entries_size = t->table->entries_size;
1547 tmp.valid_hooks = t->table->valid_hooks;
1549 mutex_unlock(&ebt_mutex);
1550 if (copy_to_user(user, &tmp, *len) != 0) {
1551 BUGPRINT("c2u Didn't work\n");
1558 case EBT_SO_GET_ENTRIES:
1559 case EBT_SO_GET_INIT_ENTRIES:
1560 ret = copy_everything_to_user(t, user, len, cmd);
1561 mutex_unlock(&ebt_mutex);
1565 mutex_unlock(&ebt_mutex);
1572 #ifdef CONFIG_COMPAT
1573 /* 32 bit-userspace compatibility definitions. */
1574 struct compat_ebt_replace {
1575 char name[EBT_TABLE_MAXNAMELEN];
1576 compat_uint_t valid_hooks;
1577 compat_uint_t nentries;
1578 compat_uint_t entries_size;
1579 /* start of the chains */
1580 compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
1581 /* nr of counters userspace expects back */
1582 compat_uint_t num_counters;
1583 /* where the kernel will put the old counters. */
1584 compat_uptr_t counters;
1585 compat_uptr_t entries;
1588 /* struct ebt_entry_match, _target and _watcher have same layout */
1589 struct compat_ebt_entry_mwt {
1591 char name[EBT_FUNCTION_MAXNAMELEN];
1594 compat_uint_t match_size;
1595 compat_uint_t data[0];
1598 /* account for possible padding between match_size and ->data */
1599 static int ebt_compat_entry_padsize(void)
1601 BUILD_BUG_ON(XT_ALIGN(sizeof(struct ebt_entry_match)) <
1602 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt)));
1603 return (int) XT_ALIGN(sizeof(struct ebt_entry_match)) -
1604 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt));
1607 static int ebt_compat_match_offset(const struct xt_match *match,
1608 unsigned int userlen)
1610 /* ebt_among needs special handling. The kernel .matchsize is
1611 * set to -1 at registration time; at runtime an EBT_ALIGN()ed
1612 * value is expected.
1613 * Example: userspace sends 4500, ebt_among.c wants 4504.
1615 if (unlikely(match->matchsize == -1))
1616 return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
1617 return xt_compat_match_offset(match);
1620 static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
1623 const struct xt_match *match = m->u.match;
1624 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1625 int off = ebt_compat_match_offset(match, m->match_size);
1626 compat_uint_t msize = m->match_size - off;
1628 BUG_ON(off >= m->match_size);
1630 if (copy_to_user(cm->u.name, match->name,
1631 strlen(match->name) + 1) || put_user(msize, &cm->match_size))
1634 if (match->compat_to_user) {
1635 if (match->compat_to_user(cm->data, m->data))
1637 } else if (copy_to_user(cm->data, m->data, msize))
1640 *size -= ebt_compat_entry_padsize() + off;
1646 static int compat_target_to_user(struct ebt_entry_target *t,
1647 void __user **dstptr,
1650 const struct xt_target *target = t->u.target;
1651 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1652 int off = xt_compat_target_offset(target);
1653 compat_uint_t tsize = t->target_size - off;
1655 BUG_ON(off >= t->target_size);
1657 if (copy_to_user(cm->u.name, target->name,
1658 strlen(target->name) + 1) || put_user(tsize, &cm->match_size))
1661 if (target->compat_to_user) {
1662 if (target->compat_to_user(cm->data, t->data))
1664 } else if (copy_to_user(cm->data, t->data, tsize))
1667 *size -= ebt_compat_entry_padsize() + off;
1673 static int compat_watcher_to_user(struct ebt_entry_watcher *w,
1674 void __user **dstptr,
1677 return compat_target_to_user((struct ebt_entry_target *)w,
1681 static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
1684 struct ebt_entry_target *t;
1685 struct ebt_entry __user *ce;
1686 u32 watchers_offset, target_offset, next_offset;
1687 compat_uint_t origsize;
1690 if (e->bitmask == 0) {
1691 if (*size < sizeof(struct ebt_entries))
1693 if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries)))
1696 *dstptr += sizeof(struct ebt_entries);
1697 *size -= sizeof(struct ebt_entries);
1701 if (*size < sizeof(*ce))
1704 ce = (struct ebt_entry __user *)*dstptr;
1705 if (copy_to_user(ce, e, sizeof(*ce)))
1709 *dstptr += sizeof(*ce);
1711 ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
1714 watchers_offset = e->watchers_offset - (origsize - *size);
1716 ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
1719 target_offset = e->target_offset - (origsize - *size);
1721 t = (struct ebt_entry_target *) ((char *) e + e->target_offset);
1723 ret = compat_target_to_user(t, dstptr, size);
1726 next_offset = e->next_offset - (origsize - *size);
1728 if (put_user(watchers_offset, &ce->watchers_offset) ||
1729 put_user(target_offset, &ce->target_offset) ||
1730 put_user(next_offset, &ce->next_offset))
1733 *size -= sizeof(*ce);
1737 static int compat_calc_match(struct ebt_entry_match *m, int *off)
1739 *off += ebt_compat_match_offset(m->u.match, m->match_size);
1740 *off += ebt_compat_entry_padsize();
1744 static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
1746 *off += xt_compat_target_offset(w->u.watcher);
1747 *off += ebt_compat_entry_padsize();
1751 static int compat_calc_entry(const struct ebt_entry *e,
1752 const struct ebt_table_info *info,
1754 struct compat_ebt_replace *newinfo)
1756 const struct ebt_entry_target *t;
1757 unsigned int entry_offset;
1760 if (e->bitmask == 0)
1764 entry_offset = (void *)e - base;
1766 EBT_MATCH_ITERATE(e, compat_calc_match, &off);
1767 EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
1769 t = (const struct ebt_entry_target *) ((char *) e + e->target_offset);
1771 off += xt_compat_target_offset(t->u.target);
1772 off += ebt_compat_entry_padsize();
1774 newinfo->entries_size -= off;
1776 ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off);
1780 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1781 const void *hookptr = info->hook_entry[i];
1782 if (info->hook_entry[i] &&
1783 (e < (struct ebt_entry *)(base - hookptr))) {
1784 newinfo->hook_entry[i] -= off;
1785 pr_debug("0x%08X -> 0x%08X\n",
1786 newinfo->hook_entry[i] + off,
1787 newinfo->hook_entry[i]);
1795 static int compat_table_info(const struct ebt_table_info *info,
1796 struct compat_ebt_replace *newinfo)
1798 unsigned int size = info->entries_size;
1799 const void *entries = info->entries;
1801 newinfo->entries_size = size;
1803 xt_compat_init_offsets(NFPROTO_BRIDGE, info->nentries);
1804 return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
1808 static int compat_copy_everything_to_user(struct ebt_table *t,
1809 void __user *user, int *len, int cmd)
1811 struct compat_ebt_replace repl, tmp;
1812 struct ebt_counter *oldcounters;
1813 struct ebt_table_info tinfo;
1817 memset(&tinfo, 0, sizeof(tinfo));
1819 if (cmd == EBT_SO_GET_ENTRIES) {
1820 tinfo.entries_size = t->private->entries_size;
1821 tinfo.nentries = t->private->nentries;
1822 tinfo.entries = t->private->entries;
1823 oldcounters = t->private->counters;
1825 tinfo.entries_size = t->table->entries_size;
1826 tinfo.nentries = t->table->nentries;
1827 tinfo.entries = t->table->entries;
1828 oldcounters = t->table->counters;
1831 if (copy_from_user(&tmp, user, sizeof(tmp)))
1834 if (tmp.nentries != tinfo.nentries ||
1835 (tmp.num_counters && tmp.num_counters != tinfo.nentries))
1838 memcpy(&repl, &tmp, sizeof(repl));
1839 if (cmd == EBT_SO_GET_ENTRIES)
1840 ret = compat_table_info(t->private, &repl);
1842 ret = compat_table_info(&tinfo, &repl);
1846 if (*len != sizeof(tmp) + repl.entries_size +
1847 (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
1848 pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
1849 *len, tinfo.entries_size, repl.entries_size);
1853 /* userspace might not need the counters */
1854 ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters),
1855 tmp.num_counters, tinfo.nentries);
1859 pos = compat_ptr(tmp.entries);
1860 return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
1861 compat_copy_entry_to_user, &pos, &tmp.entries_size);
1864 struct ebt_entries_buf_state {
1865 char *buf_kern_start; /* kernel buffer to copy (translated) data to */
1866 u32 buf_kern_len; /* total size of kernel buffer */
1867 u32 buf_kern_offset; /* amount of data copied so far */
1868 u32 buf_user_offset; /* read position in userspace buffer */
1871 static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
1873 state->buf_kern_offset += sz;
1874 return state->buf_kern_offset >= sz ? 0 : -EINVAL;
1877 static int ebt_buf_add(struct ebt_entries_buf_state *state,
1878 void *data, unsigned int sz)
1880 if (state->buf_kern_start == NULL)
1883 BUG_ON(state->buf_kern_offset + sz > state->buf_kern_len);
1885 memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz);
1888 state->buf_user_offset += sz;
1889 return ebt_buf_count(state, sz);
1892 static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz)
1894 char *b = state->buf_kern_start;
1896 BUG_ON(b && state->buf_kern_offset > state->buf_kern_len);
1898 if (b != NULL && sz > 0)
1899 memset(b + state->buf_kern_offset, 0, sz);
1900 /* do not adjust ->buf_user_offset here, we added kernel-side padding */
1901 return ebt_buf_count(state, sz);
1910 static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt,
1911 enum compat_mwt compat_mwt,
1912 struct ebt_entries_buf_state *state,
1913 const unsigned char *base)
1915 char name[EBT_FUNCTION_MAXNAMELEN];
1916 struct xt_match *match;
1917 struct xt_target *wt;
1920 unsigned int size_kern, match_size = mwt->match_size;
1922 strlcpy(name, mwt->u.name, sizeof(name));
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 BUG_ON(state->buf_kern_len <= pad);
1974 BUG_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad);
1975 memset(dst + size_kern, 0, pad);
1977 return off + match_size;
1980 /* return size of all matches, watchers or target, including necessary
1981 * alignment and padding.
1983 static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32,
1984 unsigned int size_left, enum compat_mwt type,
1985 struct ebt_entries_buf_state *state, const void *base)
1993 buf = (char *) match32;
1995 while (size_left >= sizeof(*match32)) {
1996 struct ebt_entry_match *match_kern;
1999 match_kern = (struct ebt_entry_match *) state->buf_kern_start;
2002 tmp = state->buf_kern_start + state->buf_kern_offset;
2003 match_kern = (struct ebt_entry_match *) tmp;
2005 ret = ebt_buf_add(state, buf, sizeof(*match32));
2008 size_left -= sizeof(*match32);
2010 /* add padding before match->data (if any) */
2011 ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize());
2015 if (match32->match_size > size_left)
2018 size_left -= match32->match_size;
2020 ret = compat_mtw_from_user(match32, type, state, base);
2024 BUG_ON(ret < match32->match_size);
2025 growth += ret - match32->match_size;
2026 growth += ebt_compat_entry_padsize();
2028 buf += sizeof(*match32);
2029 buf += match32->match_size;
2032 match_kern->match_size = ret;
2034 WARN_ON(type == EBT_COMPAT_TARGET && size_left);
2035 match32 = (struct compat_ebt_entry_mwt *) buf;
2041 /* called for all ebt_entry structures. */
2042 static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,
2043 unsigned int *total,
2044 struct ebt_entries_buf_state *state)
2046 unsigned int i, j, startoff, new_offset = 0;
2047 /* stores match/watchers/targets & offset of next struct ebt_entry: */
2048 unsigned int offsets[4];
2049 unsigned int *offsets_update = NULL;
2053 if (*total < sizeof(struct ebt_entries))
2056 if (!entry->bitmask) {
2057 *total -= sizeof(struct ebt_entries);
2058 return ebt_buf_add(state, entry, sizeof(struct ebt_entries));
2060 if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
2063 startoff = state->buf_user_offset;
2064 /* pull in most part of ebt_entry, it does not need to be changed. */
2065 ret = ebt_buf_add(state, entry,
2066 offsetof(struct ebt_entry, watchers_offset));
2070 offsets[0] = sizeof(struct ebt_entry); /* matches come first */
2071 memcpy(&offsets[1], &entry->watchers_offset,
2072 sizeof(offsets) - sizeof(offsets[0]));
2074 if (state->buf_kern_start) {
2075 buf_start = state->buf_kern_start + state->buf_kern_offset;
2076 offsets_update = (unsigned int *) buf_start;
2078 ret = ebt_buf_add(state, &offsets[1],
2079 sizeof(offsets) - sizeof(offsets[0]));
2082 buf_start = (char *) entry;
2083 /* 0: matches offset, always follows ebt_entry.
2084 * 1: watchers offset, from ebt_entry structure
2085 * 2: target offset, from ebt_entry structure
2086 * 3: next ebt_entry offset, from ebt_entry structure
2088 * offsets are relative to beginning of struct ebt_entry (i.e., 0).
2090 for (i = 0, j = 1 ; j < 4 ; j++, i++) {
2091 struct compat_ebt_entry_mwt *match32;
2093 char *buf = buf_start;
2095 buf = buf_start + offsets[i];
2096 if (offsets[i] > offsets[j])
2099 match32 = (struct compat_ebt_entry_mwt *) buf;
2100 size = offsets[j] - offsets[i];
2101 ret = ebt_size_mwt(match32, size, i, state, base);
2105 if (offsets_update && new_offset) {
2106 pr_debug("change offset %d to %d\n",
2107 offsets_update[i], offsets[j] + new_offset);
2108 offsets_update[i] = offsets[j] + new_offset;
2112 if (state->buf_kern_start == NULL) {
2113 unsigned int offset = buf_start - (char *) base;
2115 ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);
2120 startoff = state->buf_user_offset - startoff;
2122 BUG_ON(*total < startoff);
2127 /* repl->entries_size is the size of the ebt_entry blob in userspace.
2128 * It might need more memory when copied to a 64 bit kernel in case
2129 * userspace is 32-bit. So, first task: find out how much memory is needed.
2131 * Called before validation is performed.
2133 static int compat_copy_entries(unsigned char *data, unsigned int size_user,
2134 struct ebt_entries_buf_state *state)
2136 unsigned int size_remaining = size_user;
2139 ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
2140 &size_remaining, state);
2144 WARN_ON(size_remaining);
2145 return state->buf_kern_offset;
2149 static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
2150 void __user *user, unsigned int len)
2152 struct compat_ebt_replace tmp;
2155 if (len < sizeof(tmp))
2158 if (copy_from_user(&tmp, user, sizeof(tmp)))
2161 if (len != sizeof(tmp) + tmp.entries_size)
2164 if (tmp.entries_size == 0)
2167 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
2168 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
2170 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
2173 memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
2175 /* starting with hook_entry, 32 vs. 64 bit structures are different */
2176 for (i = 0; i < NF_BR_NUMHOOKS; i++)
2177 repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]);
2179 repl->num_counters = tmp.num_counters;
2180 repl->counters = compat_ptr(tmp.counters);
2181 repl->entries = compat_ptr(tmp.entries);
2185 static int compat_do_replace(struct net *net, void __user *user,
2188 int ret, i, countersize, size64;
2189 struct ebt_table_info *newinfo;
2190 struct ebt_replace tmp;
2191 struct ebt_entries_buf_state state;
2194 ret = compat_copy_ebt_replace_from_user(&tmp, user, len);
2196 /* try real handler in case userland supplied needed padding */
2197 if (ret == -EINVAL && do_replace(net, user, len) == 0)
2202 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
2203 newinfo = vmalloc(sizeof(*newinfo) + countersize);
2208 memset(newinfo->counters, 0, countersize);
2210 memset(&state, 0, sizeof(state));
2212 newinfo->entries = vmalloc(tmp.entries_size);
2213 if (!newinfo->entries) {
2218 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
2223 entries_tmp = newinfo->entries;
2225 xt_compat_lock(NFPROTO_BRIDGE);
2227 xt_compat_init_offsets(NFPROTO_BRIDGE, tmp.nentries);
2228 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2232 pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
2233 tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
2234 xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
2237 newinfo->entries = vmalloc(size64);
2238 if (!newinfo->entries) {
2244 memset(&state, 0, sizeof(state));
2245 state.buf_kern_start = newinfo->entries;
2246 state.buf_kern_len = size64;
2248 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2249 BUG_ON(ret < 0); /* parses same data again */
2252 tmp.entries_size = size64;
2254 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
2255 char __user *usrptr;
2256 if (tmp.hook_entry[i]) {
2258 usrptr = (char __user *) tmp.hook_entry[i];
2259 delta = usrptr - tmp.entries;
2260 usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta);
2261 tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
2265 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2266 xt_compat_unlock(NFPROTO_BRIDGE);
2268 ret = do_replace_finish(net, &tmp, newinfo);
2272 vfree(newinfo->entries);
2277 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2278 xt_compat_unlock(NFPROTO_BRIDGE);
2282 static int compat_update_counters(struct net *net, void __user *user,
2285 struct compat_ebt_replace hlp;
2287 if (copy_from_user(&hlp, user, sizeof(hlp)))
2290 /* try real handler in case userland supplied needed padding */
2291 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
2292 return update_counters(net, user, len);
2294 return do_update_counters(net, hlp.name, compat_ptr(hlp.counters),
2295 hlp.num_counters, user, len);
2298 static int compat_do_ebt_set_ctl(struct sock *sk,
2299 int cmd, void __user *user, unsigned int len)
2302 struct net *net = sock_net(sk);
2304 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2308 case EBT_SO_SET_ENTRIES:
2309 ret = compat_do_replace(net, user, len);
2311 case EBT_SO_SET_COUNTERS:
2312 ret = compat_update_counters(net, user, len);
2320 static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
2321 void __user *user, int *len)
2324 struct compat_ebt_replace tmp;
2325 struct ebt_table *t;
2326 struct net *net = sock_net(sk);
2328 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2331 /* try real handler in case userland supplied needed padding */
2332 if ((cmd == EBT_SO_GET_INFO ||
2333 cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp))
2334 return do_ebt_get_ctl(sk, cmd, user, len);
2336 if (copy_from_user(&tmp, user, sizeof(tmp)))
2339 tmp.name[sizeof(tmp.name) - 1] = '\0';
2341 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
2345 xt_compat_lock(NFPROTO_BRIDGE);
2347 case EBT_SO_GET_INFO:
2348 tmp.nentries = t->private->nentries;
2349 ret = compat_table_info(t->private, &tmp);
2352 tmp.valid_hooks = t->valid_hooks;
2354 if (copy_to_user(user, &tmp, *len) != 0) {
2360 case EBT_SO_GET_INIT_INFO:
2361 tmp.nentries = t->table->nentries;
2362 tmp.entries_size = t->table->entries_size;
2363 tmp.valid_hooks = t->table->valid_hooks;
2365 if (copy_to_user(user, &tmp, *len) != 0) {
2371 case EBT_SO_GET_ENTRIES:
2372 case EBT_SO_GET_INIT_ENTRIES:
2373 /* try real handler first in case of userland-side padding.
2374 * in case we are dealing with an 'ordinary' 32 bit binary
2375 * without 64bit compatibility padding, this will fail right
2376 * after copy_from_user when the *len argument is validated.
2378 * the compat_ variant needs to do one pass over the kernel
2379 * data set to adjust for size differences before it the check.
2381 if (copy_everything_to_user(t, user, len, cmd) == 0)
2384 ret = compat_copy_everything_to_user(t, user, len, cmd);
2390 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2391 xt_compat_unlock(NFPROTO_BRIDGE);
2392 mutex_unlock(&ebt_mutex);
2397 static struct nf_sockopt_ops ebt_sockopts = {
2399 .set_optmin = EBT_BASE_CTL,
2400 .set_optmax = EBT_SO_SET_MAX + 1,
2401 .set = do_ebt_set_ctl,
2402 #ifdef CONFIG_COMPAT
2403 .compat_set = compat_do_ebt_set_ctl,
2405 .get_optmin = EBT_BASE_CTL,
2406 .get_optmax = EBT_SO_GET_MAX + 1,
2407 .get = do_ebt_get_ctl,
2408 #ifdef CONFIG_COMPAT
2409 .compat_get = compat_do_ebt_get_ctl,
2411 .owner = THIS_MODULE,
2414 static int __init ebtables_init(void)
2418 ret = xt_register_target(&ebt_standard_target);
2421 ret = nf_register_sockopt(&ebt_sockopts);
2423 xt_unregister_target(&ebt_standard_target);
2427 printk(KERN_INFO "Ebtables v2.0 registered\n");
2431 static void __exit ebtables_fini(void)
2433 nf_unregister_sockopt(&ebt_sockopts);
2434 xt_unregister_target(&ebt_standard_target);
2435 printk(KERN_INFO "Ebtables v2.0 unregistered\n");
2438 EXPORT_SYMBOL(ebt_register_table);
2439 EXPORT_SYMBOL(ebt_unregister_table);
2440 EXPORT_SYMBOL(ebt_do_table);
2441 module_init(ebtables_init);
2442 module_exit(ebtables_fini);
2443 MODULE_LICENSE("GPL");