5 * Bart De Schuymer <bdschuym@pandora.be>
7 * ebtables.c,v 2.0, July, 2002
9 * This code is strongly inspired by the iptables code which is
10 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/kmod.h>
19 #include <linux/module.h>
20 #include <linux/vmalloc.h>
21 #include <linux/netfilter/x_tables.h>
22 #include <linux/netfilter_bridge/ebtables.h>
23 #include <linux/spinlock.h>
24 #include <linux/mutex.h>
25 #include <linux/slab.h>
26 #include <linux/uaccess.h>
27 #include <linux/smp.h>
28 #include <linux/cpumask.h>
29 #include <linux/audit.h>
31 /* needed for logical [in,out]-dev filtering */
32 #include "../br_private.h"
34 #define BUGPRINT(format, args...) printk("kernel msg: ebtables bug: please "\
35 "report to author: "format, ## args)
36 /* #define BUGPRINT(format, args...) */
38 /* Each cpu has its own set of counters, so there is no need for write_lock in
40 * For reading or updating the counters, the user context needs to
44 /* The size of each set of counters is altered to get cache alignment */
45 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
46 #define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter)))
47 #define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \
48 COUNTER_OFFSET(n) * cpu))
52 static DEFINE_MUTEX(ebt_mutex);
55 static void ebt_standard_compat_from_user(void *dst, const void *src)
57 int v = *(compat_int_t *)src;
60 v += xt_compat_calc_jump(NFPROTO_BRIDGE, v);
61 memcpy(dst, &v, sizeof(v));
64 static int ebt_standard_compat_to_user(void __user *dst, const void *src)
66 compat_int_t cv = *(int *)src;
69 cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv);
70 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
75 static struct xt_target ebt_standard_target = {
78 .family = NFPROTO_BRIDGE,
79 .targetsize = sizeof(int),
81 .compatsize = sizeof(compat_int_t),
82 .compat_from_user = ebt_standard_compat_from_user,
83 .compat_to_user = ebt_standard_compat_to_user,
88 ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb,
89 struct xt_action_param *par)
91 par->target = w->u.watcher;
92 par->targinfo = w->data;
93 w->u.watcher->target(skb, par);
94 /* watchers don't give a verdict */
99 ebt_do_match(struct ebt_entry_match *m, const struct sk_buff *skb,
100 struct xt_action_param *par)
102 par->match = m->u.match;
103 par->matchinfo = m->data;
104 return !m->u.match->match(skb, par);
108 ebt_dev_check(const char *entry, const struct net_device *device)
117 devname = device->name;
118 /* 1 is the wildcard token */
119 while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i])
121 return devname[i] != entry[i] && entry[i] != 1;
124 /* process standard matches */
126 ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb,
127 const struct net_device *in, const struct net_device *out)
129 const struct ethhdr *h = eth_hdr(skb);
130 const struct net_bridge_port *p;
133 if (skb_vlan_tag_present(skb))
134 ethproto = htons(ETH_P_8021Q);
136 ethproto = h->h_proto;
138 if (e->bitmask & EBT_802_3) {
139 if (NF_INVF(e, EBT_IPROTO, eth_proto_is_802_3(ethproto)))
141 } else if (!(e->bitmask & EBT_NOPROTO) &&
142 NF_INVF(e, EBT_IPROTO, e->ethproto != ethproto))
145 if (NF_INVF(e, EBT_IIN, ebt_dev_check(e->in, in)))
147 if (NF_INVF(e, EBT_IOUT, ebt_dev_check(e->out, out)))
149 /* rcu_read_lock()ed by nf_hook_thresh */
150 if (in && (p = br_port_get_rcu(in)) != NULL &&
151 NF_INVF(e, EBT_ILOGICALIN,
152 ebt_dev_check(e->logical_in, p->br->dev)))
154 if (out && (p = br_port_get_rcu(out)) != NULL &&
155 NF_INVF(e, EBT_ILOGICALOUT,
156 ebt_dev_check(e->logical_out, p->br->dev)))
159 if (e->bitmask & EBT_SOURCEMAC) {
160 if (NF_INVF(e, EBT_ISOURCE,
161 !ether_addr_equal_masked(h->h_source, e->sourcemac,
165 if (e->bitmask & EBT_DESTMAC) {
166 if (NF_INVF(e, EBT_IDEST,
167 !ether_addr_equal_masked(h->h_dest, e->destmac,
175 struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry)
177 return (void *)entry + entry->next_offset;
180 static inline const struct ebt_entry_target *
181 ebt_get_target_c(const struct ebt_entry *e)
183 return ebt_get_target((struct ebt_entry *)e);
186 /* Do some firewalling */
187 unsigned int ebt_do_table(struct sk_buff *skb,
188 const struct nf_hook_state *state,
189 struct ebt_table *table)
191 unsigned int hook = state->hook;
193 struct ebt_entry *point;
194 struct ebt_counter *counter_base, *cb_base;
195 const struct ebt_entry_target *t;
197 struct ebt_chainstack *cs;
198 struct ebt_entries *chaininfo;
200 const struct ebt_table_info *private;
201 struct xt_action_param acpar;
204 acpar.hotdrop = false;
206 read_lock_bh(&table->lock);
207 private = table->private;
208 cb_base = COUNTER_BASE(private->counters, private->nentries,
210 if (private->chainstack)
211 cs = private->chainstack[smp_processor_id()];
214 chaininfo = private->hook_entry[hook];
215 nentries = private->hook_entry[hook]->nentries;
216 point = (struct ebt_entry *)(private->hook_entry[hook]->data);
217 counter_base = cb_base + private->hook_entry[hook]->counter_offset;
218 /* base for chain jumps */
219 base = private->entries;
221 while (i < nentries) {
222 if (ebt_basic_match(point, skb, state->in, state->out))
225 if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0)
228 read_unlock_bh(&table->lock);
232 ADD_COUNTER(*(counter_base + i), 1, 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 = ebt_get_target_c(point);
240 /* standard target */
241 if (!t->u.target->target)
242 verdict = ((struct ebt_standard_target *)t)->verdict;
244 acpar.target = t->u.target;
245 acpar.targinfo = t->data;
246 verdict = t->u.target->target(skb, &acpar);
248 if (verdict == EBT_ACCEPT) {
249 read_unlock_bh(&table->lock);
252 if (verdict == EBT_DROP) {
253 read_unlock_bh(&table->lock);
256 if (verdict == EBT_RETURN) {
258 if (WARN(sp == 0, "RETURN on base chain")) {
259 /* act like this is EBT_CONTINUE */
264 /* put all the local variables right */
266 chaininfo = cs[sp].chaininfo;
267 nentries = chaininfo->nentries;
269 counter_base = cb_base +
270 chaininfo->counter_offset;
273 if (verdict == EBT_CONTINUE)
276 if (WARN(verdict < 0, "bogus standard verdict\n")) {
277 read_unlock_bh(&table->lock);
283 cs[sp].chaininfo = chaininfo;
284 cs[sp].e = ebt_next_entry(point);
286 chaininfo = (struct ebt_entries *) (base + verdict);
288 if (WARN(chaininfo->distinguisher, "jump to non-chain\n")) {
289 read_unlock_bh(&table->lock);
293 nentries = chaininfo->nentries;
294 point = (struct ebt_entry *)chaininfo->data;
295 counter_base = cb_base + chaininfo->counter_offset;
299 point = ebt_next_entry(point);
303 /* I actually like this :) */
304 if (chaininfo->policy == EBT_RETURN)
306 if (chaininfo->policy == EBT_ACCEPT) {
307 read_unlock_bh(&table->lock);
310 read_unlock_bh(&table->lock);
314 /* If it succeeds, returns element and locks mutex */
316 find_inlist_lock_noload(struct list_head *head, const char *name, int *error,
320 struct list_head list;
321 char name[EBT_FUNCTION_MAXNAMELEN];
325 list_for_each_entry(e, head, list) {
326 if (strcmp(e->name, name) == 0)
335 find_inlist_lock(struct list_head *head, const char *name, const char *prefix,
336 int *error, struct mutex *mutex)
338 return try_then_request_module(
339 find_inlist_lock_noload(head, name, error, mutex),
340 "%s%s", prefix, name);
343 static inline struct ebt_table *
344 find_table_lock(struct net *net, const char *name, int *error,
347 return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name,
348 "ebtable_", error, mutex);
351 static inline void ebt_free_table_info(struct ebt_table_info *info)
355 if (info->chainstack) {
356 for_each_possible_cpu(i)
357 vfree(info->chainstack[i]);
358 vfree(info->chainstack);
362 ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
365 const struct ebt_entry *e = par->entryinfo;
366 struct xt_match *match;
367 size_t left = ((char *)e + e->watchers_offset) - (char *)m;
370 if (left < sizeof(struct ebt_entry_match) ||
371 left - sizeof(struct ebt_entry_match) < m->match_size)
374 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision);
375 if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) {
377 module_put(match->me);
378 request_module("ebt_%s", m->u.name);
379 match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision);
382 return PTR_ERR(match);
386 par->matchinfo = m->data;
387 ret = xt_check_match(par, m->match_size,
388 e->ethproto, e->invflags & EBT_IPROTO);
390 module_put(match->me);
399 ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
402 const struct ebt_entry *e = par->entryinfo;
403 struct xt_target *watcher;
404 size_t left = ((char *)e + e->target_offset) - (char *)w;
407 if (left < sizeof(struct ebt_entry_watcher) ||
408 left - sizeof(struct ebt_entry_watcher) < w->watcher_size)
411 watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0);
413 return PTR_ERR(watcher);
414 w->u.watcher = watcher;
416 par->target = watcher;
417 par->targinfo = w->data;
418 ret = xt_check_target(par, w->watcher_size,
419 e->ethproto, e->invflags & EBT_IPROTO);
421 module_put(watcher->me);
429 static int ebt_verify_pointers(const struct ebt_replace *repl,
430 struct ebt_table_info *newinfo)
432 unsigned int limit = repl->entries_size;
433 unsigned int valid_hooks = repl->valid_hooks;
434 unsigned int offset = 0;
437 for (i = 0; i < NF_BR_NUMHOOKS; i++)
438 newinfo->hook_entry[i] = NULL;
440 newinfo->entries_size = repl->entries_size;
441 newinfo->nentries = repl->nentries;
443 while (offset < limit) {
444 size_t left = limit - offset;
445 struct ebt_entry *e = (void *)newinfo->entries + offset;
447 if (left < sizeof(unsigned int))
450 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
451 if ((valid_hooks & (1 << i)) == 0)
453 if ((char __user *)repl->hook_entry[i] ==
454 repl->entries + offset)
458 if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
459 if (e->bitmask != 0) {
460 /* we make userspace set this right,
461 * so there is no misunderstanding
463 BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set "
464 "in distinguisher\n");
467 if (i != NF_BR_NUMHOOKS)
468 newinfo->hook_entry[i] = (struct ebt_entries *)e;
469 if (left < sizeof(struct ebt_entries))
471 offset += sizeof(struct ebt_entries);
473 if (left < sizeof(struct ebt_entry))
475 if (left < e->next_offset)
477 if (e->next_offset < sizeof(struct ebt_entry))
479 offset += e->next_offset;
482 if (offset != limit) {
483 BUGPRINT("entries_size too small\n");
487 /* check if all valid hooks have a chain */
488 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
489 if (!newinfo->hook_entry[i] &&
490 (valid_hooks & (1 << i))) {
491 BUGPRINT("Valid hook without chain\n");
498 /* this one is very careful, as it is the first function
499 * to parse the userspace data
502 ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
503 const struct ebt_table_info *newinfo,
504 unsigned int *n, unsigned int *cnt,
505 unsigned int *totalcnt, unsigned int *udc_cnt)
509 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
510 if ((void *)e == (void *)newinfo->hook_entry[i])
513 /* beginning of a new chain
514 * if i == NF_BR_NUMHOOKS it must be a user defined chain
516 if (i != NF_BR_NUMHOOKS || !e->bitmask) {
517 /* this checks if the previous chain has as many entries
521 BUGPRINT("nentries does not equal the nr of entries "
525 if (((struct ebt_entries *)e)->policy != EBT_DROP &&
526 ((struct ebt_entries *)e)->policy != EBT_ACCEPT) {
527 /* only RETURN from udc */
528 if (i != NF_BR_NUMHOOKS ||
529 ((struct ebt_entries *)e)->policy != EBT_RETURN) {
530 BUGPRINT("bad policy\n");
534 if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */
536 if (((struct ebt_entries *)e)->counter_offset != *totalcnt) {
537 BUGPRINT("counter_offset != totalcnt");
540 *n = ((struct ebt_entries *)e)->nentries;
544 /* a plain old entry, heh */
545 if (sizeof(struct ebt_entry) > e->watchers_offset ||
546 e->watchers_offset > e->target_offset ||
547 e->target_offset >= e->next_offset) {
548 BUGPRINT("entry offsets not in right order\n");
551 /* this is not checked anywhere else */
552 if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target)) {
553 BUGPRINT("target size too small\n");
561 struct ebt_cl_stack {
562 struct ebt_chainstack cs;
564 unsigned int hookmask;
567 /* We need these positions to check that the jumps to a different part of the
568 * entries is a jump to the beginning of a new chain.
571 ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo,
572 unsigned int *n, struct ebt_cl_stack *udc)
576 /* we're only interested in chain starts */
579 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
580 if (newinfo->hook_entry[i] == (struct ebt_entries *)e)
583 /* only care about udc */
584 if (i != NF_BR_NUMHOOKS)
587 udc[*n].cs.chaininfo = (struct ebt_entries *)e;
588 /* these initialisations are depended on later in check_chainloops() */
590 udc[*n].hookmask = 0;
597 ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i)
599 struct xt_mtdtor_param par;
601 if (i && (*i)-- == 0)
605 par.match = m->u.match;
606 par.matchinfo = m->data;
607 par.family = NFPROTO_BRIDGE;
608 if (par.match->destroy != NULL)
609 par.match->destroy(&par);
610 module_put(par.match->me);
615 ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i)
617 struct xt_tgdtor_param par;
619 if (i && (*i)-- == 0)
623 par.target = w->u.watcher;
624 par.targinfo = w->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_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
635 struct xt_tgdtor_param par;
636 struct ebt_entry_target *t;
641 if (cnt && (*cnt)-- == 0)
643 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL);
644 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL);
645 t = ebt_get_target(e);
648 par.target = t->u.target;
649 par.targinfo = t->data;
650 par.family = NFPROTO_BRIDGE;
651 if (par.target->destroy != NULL)
652 par.target->destroy(&par);
653 module_put(par.target->me);
658 ebt_check_entry(struct ebt_entry *e, struct net *net,
659 const struct ebt_table_info *newinfo,
660 const char *name, unsigned int *cnt,
661 struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
663 struct ebt_entry_target *t;
664 struct xt_target *target;
665 unsigned int i, j, hook = 0, hookmask = 0;
668 struct xt_mtchk_param mtpar;
669 struct xt_tgchk_param tgpar;
671 /* don't mess with the struct ebt_entries */
675 if (e->bitmask & ~EBT_F_MASK) {
676 BUGPRINT("Unknown flag for bitmask\n");
679 if (e->invflags & ~EBT_INV_MASK) {
680 BUGPRINT("Unknown flag for inv bitmask\n");
683 if ((e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3)) {
684 BUGPRINT("NOPROTO & 802_3 not allowed\n");
687 /* what hook do we belong to? */
688 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
689 if (!newinfo->hook_entry[i])
691 if ((char *)newinfo->hook_entry[i] < (char *)e)
696 /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on
699 if (i < NF_BR_NUMHOOKS)
700 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
702 for (i = 0; i < udc_cnt; i++)
703 if ((char *)(cl_s[i].cs.chaininfo) > (char *)e)
706 hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
708 hookmask = cl_s[i - 1].hookmask;
712 mtpar.net = tgpar.net = net;
713 mtpar.table = tgpar.table = name;
714 mtpar.entryinfo = tgpar.entryinfo = e;
715 mtpar.hook_mask = tgpar.hook_mask = hookmask;
716 mtpar.family = tgpar.family = NFPROTO_BRIDGE;
717 ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i);
719 goto cleanup_matches;
721 ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j);
723 goto cleanup_watchers;
724 t = ebt_get_target(e);
725 gap = e->next_offset - e->target_offset;
727 target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0);
728 if (IS_ERR(target)) {
729 ret = PTR_ERR(target);
730 goto cleanup_watchers;
733 t->u.target = target;
734 if (t->u.target == &ebt_standard_target) {
735 if (gap < sizeof(struct ebt_standard_target)) {
736 BUGPRINT("Standard target size too big\n");
738 goto cleanup_watchers;
740 if (((struct ebt_standard_target *)t)->verdict <
741 -NUM_STANDARD_TARGETS) {
742 BUGPRINT("Invalid standard target\n");
744 goto cleanup_watchers;
746 } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) {
747 module_put(t->u.target->me);
749 goto cleanup_watchers;
752 tgpar.target = target;
753 tgpar.targinfo = t->data;
754 ret = xt_check_target(&tgpar, t->target_size,
755 e->ethproto, e->invflags & EBT_IPROTO);
757 module_put(target->me);
758 goto cleanup_watchers;
763 EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j);
765 EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i);
769 /* checks for loops and sets the hook mask for udc
770 * the hook mask for udc tells us from which base chains the udc can be
771 * accessed. This mask is a parameter to the check() functions of the extensions
773 static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
774 unsigned int udc_cnt, unsigned int hooknr, char *base)
776 int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
777 const struct ebt_entry *e = (struct ebt_entry *)chain->data;
778 const struct ebt_entry_target *t;
780 while (pos < nentries || chain_nr != -1) {
781 /* end of udc, go back one 'recursion' step */
782 if (pos == nentries) {
783 /* put back values of the time when this chain was called */
784 e = cl_s[chain_nr].cs.e;
785 if (cl_s[chain_nr].from != -1)
787 cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries;
789 nentries = chain->nentries;
790 pos = cl_s[chain_nr].cs.n;
791 /* make sure we won't see a loop that isn't one */
792 cl_s[chain_nr].cs.n = 0;
793 chain_nr = cl_s[chain_nr].from;
797 t = ebt_get_target_c(e);
798 if (strcmp(t->u.name, EBT_STANDARD_TARGET))
800 if (e->target_offset + sizeof(struct ebt_standard_target) >
802 BUGPRINT("Standard target size too big\n");
805 verdict = ((struct ebt_standard_target *)t)->verdict;
806 if (verdict >= 0) { /* jump to another chain */
807 struct ebt_entries *hlp2 =
808 (struct ebt_entries *)(base + verdict);
809 for (i = 0; i < udc_cnt; i++)
810 if (hlp2 == cl_s[i].cs.chaininfo)
812 /* bad destination or loop */
814 BUGPRINT("bad destination\n");
821 if (cl_s[i].hookmask & (1 << hooknr))
823 /* this can't be 0, so the loop test is correct */
824 cl_s[i].cs.n = pos + 1;
826 cl_s[i].cs.e = ebt_next_entry(e);
827 e = (struct ebt_entry *)(hlp2->data);
828 nentries = hlp2->nentries;
829 cl_s[i].from = chain_nr;
831 /* this udc is accessible from the base chain for hooknr */
832 cl_s[i].hookmask |= (1 << hooknr);
836 e = ebt_next_entry(e);
842 /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
843 static int translate_table(struct net *net, const char *name,
844 struct ebt_table_info *newinfo)
846 unsigned int i, j, k, udc_cnt;
848 struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */
851 while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i])
853 if (i == NF_BR_NUMHOOKS) {
854 BUGPRINT("No valid hooks specified\n");
857 if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) {
858 BUGPRINT("Chains don't start at beginning\n");
861 /* make sure chains are ordered after each other in same order
862 * as their corresponding hooks
864 for (j = i + 1; j < NF_BR_NUMHOOKS; j++) {
865 if (!newinfo->hook_entry[j])
867 if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) {
868 BUGPRINT("Hook order must be followed\n");
874 /* do some early checkings and initialize some things */
875 i = 0; /* holds the expected nr. of entries for the chain */
876 j = 0; /* holds the up to now counted entries for the chain */
877 k = 0; /* holds the total nr. of entries, should equal
878 * newinfo->nentries afterwards
880 udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */
881 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
882 ebt_check_entry_size_and_hooks, newinfo,
883 &i, &j, &k, &udc_cnt);
889 BUGPRINT("nentries does not equal the nr of entries in the "
893 if (k != newinfo->nentries) {
894 BUGPRINT("Total nentries is wrong\n");
898 /* get the location of the udc, put them in an array
899 * while we're at it, allocate the chainstack
902 /* this will get free'd in do_replace()/ebt_register_table()
905 newinfo->chainstack =
906 vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack)));
907 if (!newinfo->chainstack)
909 for_each_possible_cpu(i) {
910 newinfo->chainstack[i] =
911 vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0])));
912 if (!newinfo->chainstack[i]) {
914 vfree(newinfo->chainstack[--i]);
915 vfree(newinfo->chainstack);
916 newinfo->chainstack = NULL;
921 cl_s = vmalloc(udc_cnt * sizeof(*cl_s));
924 i = 0; /* the i'th udc */
925 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
926 ebt_get_udc_positions, newinfo, &i, cl_s);
929 BUGPRINT("i != udc_cnt\n");
935 /* Check for loops */
936 for (i = 0; i < NF_BR_NUMHOOKS; i++)
937 if (newinfo->hook_entry[i])
938 if (check_chainloops(newinfo->hook_entry[i],
939 cl_s, udc_cnt, i, newinfo->entries)) {
944 /* we now know the following (along with E=mc²):
945 * - the nr of entries in each chain is right
946 * - the size of the allocated space is right
947 * - all valid hooks have a corresponding chain
948 * - there are no loops
949 * - wrong data can still be on the level of a single entry
950 * - could be there are jumps to places that are not the
951 * beginning of a chain. This can only occur in chains that
952 * are not accessible from any base chains, so we don't care.
955 /* used to know what we need to clean up if something goes wrong */
957 ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
958 ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt);
960 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
961 ebt_cleanup_entry, net, &i);
967 /* called under write_lock */
968 static void get_counters(const struct ebt_counter *oldcounters,
969 struct ebt_counter *counters, unsigned int nentries)
972 struct ebt_counter *counter_base;
974 /* counters of cpu 0 */
975 memcpy(counters, oldcounters,
976 sizeof(struct ebt_counter) * nentries);
978 /* add other counters to those of cpu 0 */
979 for_each_possible_cpu(cpu) {
982 counter_base = COUNTER_BASE(oldcounters, nentries, cpu);
983 for (i = 0; i < nentries; i++)
984 ADD_COUNTER(counters[i], counter_base[i].pcnt,
985 counter_base[i].bcnt);
989 static int do_replace_finish(struct net *net, struct ebt_replace *repl,
990 struct ebt_table_info *newinfo)
993 struct ebt_counter *counterstmp = NULL;
994 /* used to be able to unlock earlier */
995 struct ebt_table_info *table;
998 /* the user wants counters back
999 * the check on the size is done later, when we have the lock
1001 if (repl->num_counters) {
1002 unsigned long size = repl->num_counters * sizeof(*counterstmp);
1003 counterstmp = vmalloc(size);
1008 newinfo->chainstack = NULL;
1009 ret = ebt_verify_pointers(repl, newinfo);
1011 goto free_counterstmp;
1013 ret = translate_table(net, repl->name, newinfo);
1016 goto free_counterstmp;
1018 t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
1024 /* the table doesn't like it */
1025 if (t->check && (ret = t->check(newinfo, repl->valid_hooks)))
1028 if (repl->num_counters && repl->num_counters != t->private->nentries) {
1029 BUGPRINT("Wrong nr. of counters requested\n");
1034 /* we have the mutex lock, so no danger in reading this pointer */
1036 /* make sure the table can only be rmmod'ed if it contains no rules */
1037 if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) {
1040 } else if (table->nentries && !newinfo->nentries)
1042 /* we need an atomic snapshot of the counters */
1043 write_lock_bh(&t->lock);
1044 if (repl->num_counters)
1045 get_counters(t->private->counters, counterstmp,
1046 t->private->nentries);
1048 t->private = newinfo;
1049 write_unlock_bh(&t->lock);
1050 mutex_unlock(&ebt_mutex);
1051 /* so, a user can change the chains while having messed up her counter
1052 * allocation. Only reason why this is done is because this way the lock
1053 * is held only once, while this doesn't bring the kernel into a
1056 if (repl->num_counters &&
1057 copy_to_user(repl->counters, counterstmp,
1058 repl->num_counters * sizeof(struct ebt_counter))) {
1059 /* Silent error, can't fail, new table is already in place */
1060 net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n");
1063 /* decrease module count and free resources */
1064 EBT_ENTRY_ITERATE(table->entries, table->entries_size,
1065 ebt_cleanup_entry, net, NULL);
1067 vfree(table->entries);
1068 ebt_free_table_info(table);
1073 if (audit_enabled) {
1074 audit_log(audit_context(), GFP_KERNEL,
1075 AUDIT_NETFILTER_CFG,
1076 "table=%s family=%u entries=%u",
1077 repl->name, AF_BRIDGE, repl->nentries);
1083 mutex_unlock(&ebt_mutex);
1085 EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
1086 ebt_cleanup_entry, net, NULL);
1089 /* can be initialized in translate_table() */
1090 ebt_free_table_info(newinfo);
1094 /* replace the table */
1095 static int do_replace(struct net *net, const void __user *user,
1098 int ret, countersize;
1099 struct ebt_table_info *newinfo;
1100 struct ebt_replace tmp;
1102 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1105 if (len != sizeof(tmp) + tmp.entries_size) {
1106 BUGPRINT("Wrong len argument\n");
1110 if (tmp.entries_size == 0) {
1111 BUGPRINT("Entries_size never zero\n");
1114 /* overflow check */
1115 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
1116 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
1118 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
1121 tmp.name[sizeof(tmp.name) - 1] = 0;
1123 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
1124 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1129 memset(newinfo->counters, 0, countersize);
1131 newinfo->entries = vmalloc(tmp.entries_size);
1132 if (!newinfo->entries) {
1137 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
1138 BUGPRINT("Couldn't copy entries from userspace\n");
1143 ret = do_replace_finish(net, &tmp, newinfo);
1147 vfree(newinfo->entries);
1153 static void __ebt_unregister_table(struct net *net, struct ebt_table *table)
1155 mutex_lock(&ebt_mutex);
1156 list_del(&table->list);
1157 mutex_unlock(&ebt_mutex);
1158 EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
1159 ebt_cleanup_entry, net, NULL);
1160 if (table->private->nentries)
1161 module_put(table->me);
1162 vfree(table->private->entries);
1163 ebt_free_table_info(table->private);
1164 vfree(table->private);
1168 int ebt_register_table(struct net *net, const struct ebt_table *input_table,
1169 const struct nf_hook_ops *ops, struct ebt_table **res)
1171 struct ebt_table_info *newinfo;
1172 struct ebt_table *t, *table;
1173 struct ebt_replace_kernel *repl;
1174 int ret, i, countersize;
1177 if (input_table == NULL || (repl = input_table->table) == NULL ||
1178 repl->entries == NULL || repl->entries_size == 0 ||
1179 repl->counters != NULL || input_table->private != NULL) {
1180 BUGPRINT("Bad table data for ebt_register_table!!!\n");
1184 /* Don't add one table to multiple lists. */
1185 table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL);
1191 countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
1192 newinfo = vmalloc(sizeof(*newinfo) + countersize);
1197 p = vmalloc(repl->entries_size);
1201 memcpy(p, repl->entries, repl->entries_size);
1202 newinfo->entries = p;
1204 newinfo->entries_size = repl->entries_size;
1205 newinfo->nentries = repl->nentries;
1208 memset(newinfo->counters, 0, countersize);
1210 /* fill in newinfo and parse the entries */
1211 newinfo->chainstack = NULL;
1212 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1213 if ((repl->valid_hooks & (1 << i)) == 0)
1214 newinfo->hook_entry[i] = NULL;
1216 newinfo->hook_entry[i] = p +
1217 ((char *)repl->hook_entry[i] - repl->entries);
1219 ret = translate_table(net, repl->name, newinfo);
1221 BUGPRINT("Translate_table failed\n");
1222 goto free_chainstack;
1225 if (table->check && table->check(newinfo, table->valid_hooks)) {
1226 BUGPRINT("The table doesn't like its own initial data, lol\n");
1228 goto free_chainstack;
1231 table->private = newinfo;
1232 rwlock_init(&table->lock);
1233 mutex_lock(&ebt_mutex);
1234 list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
1235 if (strcmp(t->name, table->name) == 0) {
1237 BUGPRINT("Table name already exists\n");
1242 /* Hold a reference count if the chains aren't empty */
1243 if (newinfo->nentries && !try_module_get(table->me)) {
1247 list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
1248 mutex_unlock(&ebt_mutex);
1250 WRITE_ONCE(*res, table);
1255 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
1257 __ebt_unregister_table(net, table);
1263 mutex_unlock(&ebt_mutex);
1265 ebt_free_table_info(newinfo);
1266 vfree(newinfo->entries);
1275 void ebt_unregister_table(struct net *net, struct ebt_table *table,
1276 const struct nf_hook_ops *ops)
1279 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
1280 __ebt_unregister_table(net, table);
1283 /* userspace just supplied us with counters */
1284 static int do_update_counters(struct net *net, const char *name,
1285 struct ebt_counter __user *counters,
1286 unsigned int num_counters,
1287 const void __user *user, unsigned int len)
1290 struct ebt_counter *tmp;
1291 struct ebt_table *t;
1293 if (num_counters == 0)
1296 tmp = vmalloc(num_counters * sizeof(*tmp));
1300 t = find_table_lock(net, name, &ret, &ebt_mutex);
1304 if (num_counters != t->private->nentries) {
1305 BUGPRINT("Wrong nr of counters\n");
1310 if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) {
1315 /* we want an atomic add of the counters */
1316 write_lock_bh(&t->lock);
1318 /* we add to the counters of the first cpu */
1319 for (i = 0; i < num_counters; i++)
1320 ADD_COUNTER(t->private->counters[i], tmp[i].pcnt, tmp[i].bcnt);
1322 write_unlock_bh(&t->lock);
1325 mutex_unlock(&ebt_mutex);
1331 static int update_counters(struct net *net, const void __user *user,
1334 struct ebt_replace hlp;
1336 if (copy_from_user(&hlp, user, sizeof(hlp)))
1339 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
1342 return do_update_counters(net, hlp.name, hlp.counters,
1343 hlp.num_counters, user, len);
1346 static inline int ebt_obj_to_user(char __user *um, const char *_name,
1347 const char *data, int entrysize,
1348 int usersize, int datasize, u8 revision)
1350 char name[EBT_EXTENSION_MAXNAMELEN] = {0};
1352 /* ebtables expects 31 bytes long names but xt_match names are 29 bytes
1353 * long. Copy 29 bytes and fill remaining bytes with zeroes.
1355 strlcpy(name, _name, sizeof(name));
1356 if (copy_to_user(um, name, EBT_EXTENSION_MAXNAMELEN) ||
1357 put_user(revision, (u8 __user *)(um + EBT_EXTENSION_MAXNAMELEN)) ||
1358 put_user(datasize, (int __user *)(um + EBT_EXTENSION_MAXNAMELEN + 1)) ||
1359 xt_data_to_user(um + entrysize, data, usersize, datasize,
1360 XT_ALIGN(datasize)))
1366 static inline int ebt_match_to_user(const struct ebt_entry_match *m,
1367 const char *base, char __user *ubase)
1369 return ebt_obj_to_user(ubase + ((char *)m - base),
1370 m->u.match->name, m->data, sizeof(*m),
1371 m->u.match->usersize, m->match_size,
1372 m->u.match->revision);
1375 static inline int ebt_watcher_to_user(const struct ebt_entry_watcher *w,
1376 const char *base, char __user *ubase)
1378 return ebt_obj_to_user(ubase + ((char *)w - base),
1379 w->u.watcher->name, w->data, sizeof(*w),
1380 w->u.watcher->usersize, w->watcher_size,
1381 w->u.watcher->revision);
1384 static inline int ebt_entry_to_user(struct ebt_entry *e, const char *base,
1389 const struct ebt_entry_target *t;
1391 if (e->bitmask == 0) {
1392 /* special case !EBT_ENTRY_OR_ENTRIES */
1393 if (copy_to_user(ubase + ((char *)e - base), e,
1394 sizeof(struct ebt_entries)))
1399 if (copy_to_user(ubase + ((char *)e - base), e, sizeof(*e)))
1402 hlp = ubase + (((char *)e + e->target_offset) - base);
1403 t = ebt_get_target_c(e);
1405 ret = EBT_MATCH_ITERATE(e, ebt_match_to_user, base, ubase);
1408 ret = EBT_WATCHER_ITERATE(e, ebt_watcher_to_user, base, ubase);
1411 ret = ebt_obj_to_user(hlp, t->u.target->name, t->data, sizeof(*t),
1412 t->u.target->usersize, t->target_size,
1413 t->u.target->revision);
1420 static int copy_counters_to_user(struct ebt_table *t,
1421 const struct ebt_counter *oldcounters,
1422 void __user *user, unsigned int num_counters,
1423 unsigned int nentries)
1425 struct ebt_counter *counterstmp;
1428 /* userspace might not need the counters */
1429 if (num_counters == 0)
1432 if (num_counters != nentries) {
1433 BUGPRINT("Num_counters wrong\n");
1437 counterstmp = vmalloc(nentries * sizeof(*counterstmp));
1441 write_lock_bh(&t->lock);
1442 get_counters(oldcounters, counterstmp, nentries);
1443 write_unlock_bh(&t->lock);
1445 if (copy_to_user(user, counterstmp,
1446 nentries * sizeof(struct ebt_counter)))
1452 /* called with ebt_mutex locked */
1453 static int copy_everything_to_user(struct ebt_table *t, void __user *user,
1454 const int *len, int cmd)
1456 struct ebt_replace tmp;
1457 const struct ebt_counter *oldcounters;
1458 unsigned int entries_size, nentries;
1462 if (cmd == EBT_SO_GET_ENTRIES) {
1463 entries_size = t->private->entries_size;
1464 nentries = t->private->nentries;
1465 entries = t->private->entries;
1466 oldcounters = t->private->counters;
1468 entries_size = t->table->entries_size;
1469 nentries = t->table->nentries;
1470 entries = t->table->entries;
1471 oldcounters = t->table->counters;
1474 if (copy_from_user(&tmp, user, sizeof(tmp)))
1477 if (*len != sizeof(struct ebt_replace) + entries_size +
1478 (tmp.num_counters ? nentries * sizeof(struct ebt_counter) : 0))
1481 if (tmp.nentries != nentries) {
1482 BUGPRINT("Nentries wrong\n");
1486 if (tmp.entries_size != entries_size) {
1487 BUGPRINT("Wrong size\n");
1491 ret = copy_counters_to_user(t, oldcounters, tmp.counters,
1492 tmp.num_counters, nentries);
1496 /* set the match/watcher/target names right */
1497 return EBT_ENTRY_ITERATE(entries, entries_size,
1498 ebt_entry_to_user, entries, tmp.entries);
1501 static int do_ebt_set_ctl(struct sock *sk,
1502 int cmd, void __user *user, unsigned int len)
1505 struct net *net = sock_net(sk);
1507 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1511 case EBT_SO_SET_ENTRIES:
1512 ret = do_replace(net, user, len);
1514 case EBT_SO_SET_COUNTERS:
1515 ret = update_counters(net, user, len);
1523 static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1526 struct ebt_replace tmp;
1527 struct ebt_table *t;
1528 struct net *net = sock_net(sk);
1530 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1533 if (copy_from_user(&tmp, user, sizeof(tmp)))
1536 tmp.name[sizeof(tmp.name) - 1] = '\0';
1538 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
1543 case EBT_SO_GET_INFO:
1544 case EBT_SO_GET_INIT_INFO:
1545 if (*len != sizeof(struct ebt_replace)) {
1547 mutex_unlock(&ebt_mutex);
1550 if (cmd == EBT_SO_GET_INFO) {
1551 tmp.nentries = t->private->nentries;
1552 tmp.entries_size = t->private->entries_size;
1553 tmp.valid_hooks = t->valid_hooks;
1555 tmp.nentries = t->table->nentries;
1556 tmp.entries_size = t->table->entries_size;
1557 tmp.valid_hooks = t->table->valid_hooks;
1559 mutex_unlock(&ebt_mutex);
1560 if (copy_to_user(user, &tmp, *len) != 0) {
1561 BUGPRINT("c2u Didn't work\n");
1568 case EBT_SO_GET_ENTRIES:
1569 case EBT_SO_GET_INIT_ENTRIES:
1570 ret = copy_everything_to_user(t, user, len, cmd);
1571 mutex_unlock(&ebt_mutex);
1575 mutex_unlock(&ebt_mutex);
1582 #ifdef CONFIG_COMPAT
1583 /* 32 bit-userspace compatibility definitions. */
1584 struct compat_ebt_replace {
1585 char name[EBT_TABLE_MAXNAMELEN];
1586 compat_uint_t valid_hooks;
1587 compat_uint_t nentries;
1588 compat_uint_t entries_size;
1589 /* start of the chains */
1590 compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
1591 /* nr of counters userspace expects back */
1592 compat_uint_t num_counters;
1593 /* where the kernel will put the old counters. */
1594 compat_uptr_t counters;
1595 compat_uptr_t entries;
1598 /* struct ebt_entry_match, _target and _watcher have same layout */
1599 struct compat_ebt_entry_mwt {
1602 char name[EBT_EXTENSION_MAXNAMELEN];
1607 compat_uint_t match_size;
1608 compat_uint_t data[0];
1611 /* account for possible padding between match_size and ->data */
1612 static int ebt_compat_entry_padsize(void)
1614 BUILD_BUG_ON(XT_ALIGN(sizeof(struct ebt_entry_match)) <
1615 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt)));
1616 return (int) XT_ALIGN(sizeof(struct ebt_entry_match)) -
1617 COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt));
1620 static int ebt_compat_match_offset(const struct xt_match *match,
1621 unsigned int userlen)
1623 /* ebt_among needs special handling. The kernel .matchsize is
1624 * set to -1 at registration time; at runtime an EBT_ALIGN()ed
1625 * value is expected.
1626 * Example: userspace sends 4500, ebt_among.c wants 4504.
1628 if (unlikely(match->matchsize == -1))
1629 return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
1630 return xt_compat_match_offset(match);
1633 static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
1636 const struct xt_match *match = m->u.match;
1637 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1638 int off = ebt_compat_match_offset(match, m->match_size);
1639 compat_uint_t msize = m->match_size - off;
1641 if (WARN_ON(off >= m->match_size))
1644 if (copy_to_user(cm->u.name, match->name, strlen(match->name) + 1) ||
1645 put_user(match->revision, &cm->u.revision) ||
1646 put_user(msize, &cm->match_size))
1649 if (match->compat_to_user) {
1650 if (match->compat_to_user(cm->data, m->data))
1653 if (xt_data_to_user(cm->data, m->data, match->usersize, msize,
1654 COMPAT_XT_ALIGN(msize)))
1658 *size -= ebt_compat_entry_padsize() + off;
1664 static int compat_target_to_user(struct ebt_entry_target *t,
1665 void __user **dstptr,
1668 const struct xt_target *target = t->u.target;
1669 struct compat_ebt_entry_mwt __user *cm = *dstptr;
1670 int off = xt_compat_target_offset(target);
1671 compat_uint_t tsize = t->target_size - off;
1673 if (WARN_ON(off >= t->target_size))
1676 if (copy_to_user(cm->u.name, target->name, strlen(target->name) + 1) ||
1677 put_user(target->revision, &cm->u.revision) ||
1678 put_user(tsize, &cm->match_size))
1681 if (target->compat_to_user) {
1682 if (target->compat_to_user(cm->data, t->data))
1685 if (xt_data_to_user(cm->data, t->data, target->usersize, tsize,
1686 COMPAT_XT_ALIGN(tsize)))
1690 *size -= ebt_compat_entry_padsize() + off;
1696 static int compat_watcher_to_user(struct ebt_entry_watcher *w,
1697 void __user **dstptr,
1700 return compat_target_to_user((struct ebt_entry_target *)w,
1704 static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
1707 struct ebt_entry_target *t;
1708 struct ebt_entry __user *ce;
1709 u32 watchers_offset, target_offset, next_offset;
1710 compat_uint_t origsize;
1713 if (e->bitmask == 0) {
1714 if (*size < sizeof(struct ebt_entries))
1716 if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries)))
1719 *dstptr += sizeof(struct ebt_entries);
1720 *size -= sizeof(struct ebt_entries);
1724 if (*size < sizeof(*ce))
1728 if (copy_to_user(ce, e, sizeof(*ce)))
1732 *dstptr += sizeof(*ce);
1734 ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
1737 watchers_offset = e->watchers_offset - (origsize - *size);
1739 ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
1742 target_offset = e->target_offset - (origsize - *size);
1744 t = ebt_get_target(e);
1746 ret = compat_target_to_user(t, dstptr, size);
1749 next_offset = e->next_offset - (origsize - *size);
1751 if (put_user(watchers_offset, &ce->watchers_offset) ||
1752 put_user(target_offset, &ce->target_offset) ||
1753 put_user(next_offset, &ce->next_offset))
1756 *size -= sizeof(*ce);
1760 static int compat_calc_match(struct ebt_entry_match *m, int *off)
1762 *off += ebt_compat_match_offset(m->u.match, m->match_size);
1763 *off += ebt_compat_entry_padsize();
1767 static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
1769 *off += xt_compat_target_offset(w->u.watcher);
1770 *off += ebt_compat_entry_padsize();
1774 static int compat_calc_entry(const struct ebt_entry *e,
1775 const struct ebt_table_info *info,
1777 struct compat_ebt_replace *newinfo)
1779 const struct ebt_entry_target *t;
1780 unsigned int entry_offset;
1783 if (e->bitmask == 0)
1787 entry_offset = (void *)e - base;
1789 EBT_MATCH_ITERATE(e, compat_calc_match, &off);
1790 EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
1792 t = ebt_get_target_c(e);
1794 off += xt_compat_target_offset(t->u.target);
1795 off += ebt_compat_entry_padsize();
1797 newinfo->entries_size -= off;
1799 ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off);
1803 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1804 const void *hookptr = info->hook_entry[i];
1805 if (info->hook_entry[i] &&
1806 (e < (struct ebt_entry *)(base - hookptr))) {
1807 newinfo->hook_entry[i] -= off;
1808 pr_debug("0x%08X -> 0x%08X\n",
1809 newinfo->hook_entry[i] + off,
1810 newinfo->hook_entry[i]);
1818 static int compat_table_info(const struct ebt_table_info *info,
1819 struct compat_ebt_replace *newinfo)
1821 unsigned int size = info->entries_size;
1822 const void *entries = info->entries;
1824 newinfo->entries_size = size;
1825 if (info->nentries) {
1826 int ret = xt_compat_init_offsets(NFPROTO_BRIDGE,
1832 return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
1836 static int compat_copy_everything_to_user(struct ebt_table *t,
1837 void __user *user, int *len, int cmd)
1839 struct compat_ebt_replace repl, tmp;
1840 struct ebt_counter *oldcounters;
1841 struct ebt_table_info tinfo;
1845 memset(&tinfo, 0, sizeof(tinfo));
1847 if (cmd == EBT_SO_GET_ENTRIES) {
1848 tinfo.entries_size = t->private->entries_size;
1849 tinfo.nentries = t->private->nentries;
1850 tinfo.entries = t->private->entries;
1851 oldcounters = t->private->counters;
1853 tinfo.entries_size = t->table->entries_size;
1854 tinfo.nentries = t->table->nentries;
1855 tinfo.entries = t->table->entries;
1856 oldcounters = t->table->counters;
1859 if (copy_from_user(&tmp, user, sizeof(tmp)))
1862 if (tmp.nentries != tinfo.nentries ||
1863 (tmp.num_counters && tmp.num_counters != tinfo.nentries))
1866 memcpy(&repl, &tmp, sizeof(repl));
1867 if (cmd == EBT_SO_GET_ENTRIES)
1868 ret = compat_table_info(t->private, &repl);
1870 ret = compat_table_info(&tinfo, &repl);
1874 if (*len != sizeof(tmp) + repl.entries_size +
1875 (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
1876 pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
1877 *len, tinfo.entries_size, repl.entries_size);
1881 /* userspace might not need the counters */
1882 ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters),
1883 tmp.num_counters, tinfo.nentries);
1887 pos = compat_ptr(tmp.entries);
1888 return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
1889 compat_copy_entry_to_user, &pos, &tmp.entries_size);
1892 struct ebt_entries_buf_state {
1893 char *buf_kern_start; /* kernel buffer to copy (translated) data to */
1894 u32 buf_kern_len; /* total size of kernel buffer */
1895 u32 buf_kern_offset; /* amount of data copied so far */
1896 u32 buf_user_offset; /* read position in userspace buffer */
1899 static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
1901 state->buf_kern_offset += sz;
1902 return state->buf_kern_offset >= sz ? 0 : -EINVAL;
1905 static int ebt_buf_add(struct ebt_entries_buf_state *state,
1906 void *data, unsigned int sz)
1908 if (state->buf_kern_start == NULL)
1911 if (WARN_ON(state->buf_kern_offset + sz > state->buf_kern_len))
1914 memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz);
1917 state->buf_user_offset += sz;
1918 return ebt_buf_count(state, sz);
1921 static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz)
1923 char *b = state->buf_kern_start;
1925 if (WARN_ON(b && state->buf_kern_offset > state->buf_kern_len))
1928 if (b != NULL && sz > 0)
1929 memset(b + state->buf_kern_offset, 0, sz);
1930 /* do not adjust ->buf_user_offset here, we added kernel-side padding */
1931 return ebt_buf_count(state, sz);
1940 static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt,
1941 enum compat_mwt compat_mwt,
1942 struct ebt_entries_buf_state *state,
1943 const unsigned char *base)
1945 char name[EBT_EXTENSION_MAXNAMELEN];
1946 struct xt_match *match;
1947 struct xt_target *wt;
1950 unsigned int size_kern, match_size = mwt->match_size;
1952 if (strscpy(name, mwt->u.name, sizeof(name)) < 0)
1955 if (state->buf_kern_start)
1956 dst = state->buf_kern_start + state->buf_kern_offset;
1958 switch (compat_mwt) {
1959 case EBT_COMPAT_MATCH:
1960 match = xt_request_find_match(NFPROTO_BRIDGE, name,
1963 return PTR_ERR(match);
1965 off = ebt_compat_match_offset(match, match_size);
1967 if (match->compat_from_user)
1968 match->compat_from_user(dst, mwt->data);
1970 memcpy(dst, mwt->data, match_size);
1973 size_kern = match->matchsize;
1974 if (unlikely(size_kern == -1))
1975 size_kern = match_size;
1976 module_put(match->me);
1978 case EBT_COMPAT_WATCHER: /* fallthrough */
1979 case EBT_COMPAT_TARGET:
1980 wt = xt_request_find_target(NFPROTO_BRIDGE, name,
1984 off = xt_compat_target_offset(wt);
1987 if (wt->compat_from_user)
1988 wt->compat_from_user(dst, mwt->data);
1990 memcpy(dst, mwt->data, match_size);
1993 size_kern = wt->targetsize;
2001 state->buf_kern_offset += match_size + off;
2002 state->buf_user_offset += match_size;
2003 pad = XT_ALIGN(size_kern) - size_kern;
2005 if (pad > 0 && dst) {
2006 if (WARN_ON(state->buf_kern_len <= pad))
2008 if (WARN_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad))
2010 memset(dst + size_kern, 0, pad);
2012 return off + match_size;
2015 /* return size of all matches, watchers or target, including necessary
2016 * alignment and padding.
2018 static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32,
2019 unsigned int size_left, enum compat_mwt type,
2020 struct ebt_entries_buf_state *state, const void *base)
2028 buf = (char *) match32;
2030 while (size_left >= sizeof(*match32)) {
2031 struct ebt_entry_match *match_kern;
2034 match_kern = (struct ebt_entry_match *) state->buf_kern_start;
2037 tmp = state->buf_kern_start + state->buf_kern_offset;
2038 match_kern = (struct ebt_entry_match *) tmp;
2040 ret = ebt_buf_add(state, buf, sizeof(*match32));
2043 size_left -= sizeof(*match32);
2045 /* add padding before match->data (if any) */
2046 ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize());
2050 if (match32->match_size > size_left)
2053 size_left -= match32->match_size;
2055 ret = compat_mtw_from_user(match32, type, state, base);
2059 if (WARN_ON(ret < match32->match_size))
2061 growth += ret - match32->match_size;
2062 growth += ebt_compat_entry_padsize();
2064 buf += sizeof(*match32);
2065 buf += match32->match_size;
2068 match_kern->match_size = ret;
2070 if (WARN_ON(type == EBT_COMPAT_TARGET && size_left))
2073 match32 = (struct compat_ebt_entry_mwt *) buf;
2079 /* called for all ebt_entry structures. */
2080 static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,
2081 unsigned int *total,
2082 struct ebt_entries_buf_state *state)
2084 unsigned int i, j, startoff, new_offset = 0;
2085 /* stores match/watchers/targets & offset of next struct ebt_entry: */
2086 unsigned int offsets[4];
2087 unsigned int *offsets_update = NULL;
2091 if (*total < sizeof(struct ebt_entries))
2094 if (!entry->bitmask) {
2095 *total -= sizeof(struct ebt_entries);
2096 return ebt_buf_add(state, entry, sizeof(struct ebt_entries));
2098 if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
2101 startoff = state->buf_user_offset;
2102 /* pull in most part of ebt_entry, it does not need to be changed. */
2103 ret = ebt_buf_add(state, entry,
2104 offsetof(struct ebt_entry, watchers_offset));
2108 offsets[0] = sizeof(struct ebt_entry); /* matches come first */
2109 memcpy(&offsets[1], &entry->watchers_offset,
2110 sizeof(offsets) - sizeof(offsets[0]));
2112 if (state->buf_kern_start) {
2113 buf_start = state->buf_kern_start + state->buf_kern_offset;
2114 offsets_update = (unsigned int *) buf_start;
2116 ret = ebt_buf_add(state, &offsets[1],
2117 sizeof(offsets) - sizeof(offsets[0]));
2120 buf_start = (char *) entry;
2121 /* 0: matches offset, always follows ebt_entry.
2122 * 1: watchers offset, from ebt_entry structure
2123 * 2: target offset, from ebt_entry structure
2124 * 3: next ebt_entry offset, from ebt_entry structure
2126 * offsets are relative to beginning of struct ebt_entry (i.e., 0).
2128 for (i = 0; i < 4 ; ++i) {
2129 if (offsets[i] > *total)
2132 if (i < 3 && offsets[i] == *total)
2137 if (offsets[i-1] > offsets[i])
2141 for (i = 0, j = 1 ; j < 4 ; j++, i++) {
2142 struct compat_ebt_entry_mwt *match32;
2144 char *buf = buf_start + offsets[i];
2146 if (offsets[i] > offsets[j])
2149 match32 = (struct compat_ebt_entry_mwt *) buf;
2150 size = offsets[j] - offsets[i];
2151 ret = ebt_size_mwt(match32, size, i, state, base);
2155 if (offsets_update && new_offset) {
2156 pr_debug("change offset %d to %d\n",
2157 offsets_update[i], offsets[j] + new_offset);
2158 offsets_update[i] = offsets[j] + new_offset;
2162 if (state->buf_kern_start == NULL) {
2163 unsigned int offset = buf_start - (char *) base;
2165 ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);
2170 startoff = state->buf_user_offset - startoff;
2172 if (WARN_ON(*total < startoff))
2178 /* repl->entries_size is the size of the ebt_entry blob in userspace.
2179 * It might need more memory when copied to a 64 bit kernel in case
2180 * userspace is 32-bit. So, first task: find out how much memory is needed.
2182 * Called before validation is performed.
2184 static int compat_copy_entries(unsigned char *data, unsigned int size_user,
2185 struct ebt_entries_buf_state *state)
2187 unsigned int size_remaining = size_user;
2190 ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
2191 &size_remaining, state);
2195 WARN_ON(size_remaining);
2196 return state->buf_kern_offset;
2200 static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
2201 void __user *user, unsigned int len)
2203 struct compat_ebt_replace tmp;
2206 if (len < sizeof(tmp))
2209 if (copy_from_user(&tmp, user, sizeof(tmp)))
2212 if (len != sizeof(tmp) + tmp.entries_size)
2215 if (tmp.entries_size == 0)
2218 if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
2219 NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
2221 if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
2224 memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
2226 /* starting with hook_entry, 32 vs. 64 bit structures are different */
2227 for (i = 0; i < NF_BR_NUMHOOKS; i++)
2228 repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]);
2230 repl->num_counters = tmp.num_counters;
2231 repl->counters = compat_ptr(tmp.counters);
2232 repl->entries = compat_ptr(tmp.entries);
2236 static int compat_do_replace(struct net *net, void __user *user,
2239 int ret, i, countersize, size64;
2240 struct ebt_table_info *newinfo;
2241 struct ebt_replace tmp;
2242 struct ebt_entries_buf_state state;
2245 ret = compat_copy_ebt_replace_from_user(&tmp, user, len);
2247 /* try real handler in case userland supplied needed padding */
2248 if (ret == -EINVAL && do_replace(net, user, len) == 0)
2253 countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
2254 newinfo = vmalloc(sizeof(*newinfo) + countersize);
2259 memset(newinfo->counters, 0, countersize);
2261 memset(&state, 0, sizeof(state));
2263 newinfo->entries = vmalloc(tmp.entries_size);
2264 if (!newinfo->entries) {
2269 newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
2274 entries_tmp = newinfo->entries;
2276 xt_compat_lock(NFPROTO_BRIDGE);
2278 ret = xt_compat_init_offsets(NFPROTO_BRIDGE, tmp.nentries);
2281 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2285 pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
2286 tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
2287 xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
2290 newinfo->entries = vmalloc(size64);
2291 if (!newinfo->entries) {
2297 memset(&state, 0, sizeof(state));
2298 state.buf_kern_start = newinfo->entries;
2299 state.buf_kern_len = size64;
2301 ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
2302 if (WARN_ON(ret < 0))
2306 tmp.entries_size = size64;
2308 for (i = 0; i < NF_BR_NUMHOOKS; i++) {
2309 char __user *usrptr;
2310 if (tmp.hook_entry[i]) {
2312 usrptr = (char __user *) tmp.hook_entry[i];
2313 delta = usrptr - tmp.entries;
2314 usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta);
2315 tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
2319 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2320 xt_compat_unlock(NFPROTO_BRIDGE);
2322 ret = do_replace_finish(net, &tmp, newinfo);
2326 vfree(newinfo->entries);
2331 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2332 xt_compat_unlock(NFPROTO_BRIDGE);
2336 static int compat_update_counters(struct net *net, void __user *user,
2339 struct compat_ebt_replace hlp;
2341 if (copy_from_user(&hlp, user, sizeof(hlp)))
2344 /* try real handler in case userland supplied needed padding */
2345 if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
2346 return update_counters(net, user, len);
2348 return do_update_counters(net, hlp.name, compat_ptr(hlp.counters),
2349 hlp.num_counters, user, len);
2352 static int compat_do_ebt_set_ctl(struct sock *sk,
2353 int cmd, void __user *user, unsigned int len)
2356 struct net *net = sock_net(sk);
2358 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2362 case EBT_SO_SET_ENTRIES:
2363 ret = compat_do_replace(net, user, len);
2365 case EBT_SO_SET_COUNTERS:
2366 ret = compat_update_counters(net, user, len);
2374 static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
2375 void __user *user, int *len)
2378 struct compat_ebt_replace tmp;
2379 struct ebt_table *t;
2380 struct net *net = sock_net(sk);
2382 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2385 /* try real handler in case userland supplied needed padding */
2386 if ((cmd == EBT_SO_GET_INFO ||
2387 cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp))
2388 return do_ebt_get_ctl(sk, cmd, user, len);
2390 if (copy_from_user(&tmp, user, sizeof(tmp)))
2393 tmp.name[sizeof(tmp.name) - 1] = '\0';
2395 t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
2399 xt_compat_lock(NFPROTO_BRIDGE);
2401 case EBT_SO_GET_INFO:
2402 tmp.nentries = t->private->nentries;
2403 ret = compat_table_info(t->private, &tmp);
2406 tmp.valid_hooks = t->valid_hooks;
2408 if (copy_to_user(user, &tmp, *len) != 0) {
2414 case EBT_SO_GET_INIT_INFO:
2415 tmp.nentries = t->table->nentries;
2416 tmp.entries_size = t->table->entries_size;
2417 tmp.valid_hooks = t->table->valid_hooks;
2419 if (copy_to_user(user, &tmp, *len) != 0) {
2425 case EBT_SO_GET_ENTRIES:
2426 case EBT_SO_GET_INIT_ENTRIES:
2427 /* try real handler first in case of userland-side padding.
2428 * in case we are dealing with an 'ordinary' 32 bit binary
2429 * without 64bit compatibility padding, this will fail right
2430 * after copy_from_user when the *len argument is validated.
2432 * the compat_ variant needs to do one pass over the kernel
2433 * data set to adjust for size differences before it the check.
2435 if (copy_everything_to_user(t, user, len, cmd) == 0)
2438 ret = compat_copy_everything_to_user(t, user, len, cmd);
2444 xt_compat_flush_offsets(NFPROTO_BRIDGE);
2445 xt_compat_unlock(NFPROTO_BRIDGE);
2446 mutex_unlock(&ebt_mutex);
2451 static struct nf_sockopt_ops ebt_sockopts = {
2453 .set_optmin = EBT_BASE_CTL,
2454 .set_optmax = EBT_SO_SET_MAX + 1,
2455 .set = do_ebt_set_ctl,
2456 #ifdef CONFIG_COMPAT
2457 .compat_set = compat_do_ebt_set_ctl,
2459 .get_optmin = EBT_BASE_CTL,
2460 .get_optmax = EBT_SO_GET_MAX + 1,
2461 .get = do_ebt_get_ctl,
2462 #ifdef CONFIG_COMPAT
2463 .compat_get = compat_do_ebt_get_ctl,
2465 .owner = THIS_MODULE,
2468 static int __init ebtables_init(void)
2472 ret = xt_register_target(&ebt_standard_target);
2475 ret = nf_register_sockopt(&ebt_sockopts);
2477 xt_unregister_target(&ebt_standard_target);
2484 static void __exit ebtables_fini(void)
2486 nf_unregister_sockopt(&ebt_sockopts);
2487 xt_unregister_target(&ebt_standard_target);
2490 EXPORT_SYMBOL(ebt_register_table);
2491 EXPORT_SYMBOL(ebt_unregister_table);
2492 EXPORT_SYMBOL(ebt_do_table);
2493 module_init(ebtables_init);
2494 module_exit(ebtables_fini);
2495 MODULE_LICENSE("GPL");