1	// SPDX-License-Identifier: GPL-2.0-or-later
2	/*
3	* ebtables
4	*
5	* Author:
6	* Bart De Schuymer <bdschuym@pandora.be>
7	*
8	* ebtables.c,v 2.0, July, 2002
9	*
10	* This code is strongly inspired by the iptables code which is
11	* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
12	*/
13	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14	#include <linux/kmod.h>
15	#include <linux/module.h>
16	#include <linux/vmalloc.h>
17	#include <linux/netfilter/x_tables.h>
18	#include <linux/netfilter_bridge/ebtables.h>
19	#include <linux/spinlock.h>
20	#include <linux/mutex.h>
21	#include <linux/slab.h>
22	#include <linux/uaccess.h>
23	#include <linux/smp.h>
24	#include <linux/cpumask.h>
25	#include <linux/audit.h>
26	#include <net/sock.h>
27	#include <net/netns/generic.h>
28	/* needed for logical [in,out]-dev filtering */
29	#include "../br_private.h"
30
31	/* Each cpu has its own set of counters, so there is no need for write_lock in
32	* the softirq
33	* For reading or updating the counters, the user context needs to
34	* get a write_lock
35	*/
36
37	/* The size of each set of counters is altered to get cache alignment */
38	#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
39	#define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter)))
40	#define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \
41	COUNTER_OFFSET(n) * cpu))
42
43	struct ebt_pernet {
44	struct list_head tables;
45	};
46
47	struct ebt_template {
48	struct list_head list;
49	char name[EBT_TABLE_MAXNAMELEN];
50	struct module *owner;
51	/* called when table is needed in the given netns */
52	int (*table_init)(struct net *net);
53	};
54
55	static unsigned int ebt_pernet_id __read_mostly;
56	static LIST_HEAD(template_tables);
57	static DEFINE_MUTEX(ebt_mutex);
58
59	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
60	static void ebt_standard_compat_from_user(void *dst, const void *src)
61	{
62	int v = *(compat_int_t *)src;
63
64	if (v >= 0)
65	v += xt_compat_calc_jump(af: NFPROTO_BRIDGE, offset: v);
66	memcpy(dst, &v, sizeof(v));
67	}
68
69	static int ebt_standard_compat_to_user(void __user *dst, const void *src)
70	{
71	compat_int_t cv = *(int *)src;
72
73	if (cv >= 0)
74	cv -= xt_compat_calc_jump(af: NFPROTO_BRIDGE, offset: cv);
75	return copy_to_user(to: dst, from: &cv, n: sizeof(cv)) ? -EFAULT : 0;
76	}
77	#endif
78
79
80	static struct xt_target ebt_standard_target = {
81	.name = "standard",
82	.revision = 0,
83	.family = NFPROTO_BRIDGE,
84	.targetsize = sizeof(int),
85	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
86	.compatsize = sizeof(compat_int_t),
87	.compat_from_user = ebt_standard_compat_from_user,
88	.compat_to_user = ebt_standard_compat_to_user,
89	#endif
90	};
91
92	static inline int
93	ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb,
94	struct xt_action_param *par)
95	{
96	par->target = w->u.watcher;
97	par->targinfo = w->data;
98	w->u.watcher->target(skb, par);
99	/* watchers don't give a verdict */
100	return 0;
101	}
102
103	static inline int
104	ebt_do_match(struct ebt_entry_match *m, const struct sk_buff *skb,
105	struct xt_action_param *par)
106	{
107	par->match = m->u.match;
108	par->matchinfo = m->data;
109	return !m->u.match->match(skb, par);
110	}
111
112	static inline int
113	ebt_dev_check(const char *entry, const struct net_device *device)
114	{
115	int i = 0;
116	const char *devname;
117
118	if (*entry == '\0')
119	return 0;
120	if (!device)
121	return 1;
122	devname = device->name;
123	/* 1 is the wildcard token */
124	while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i])
125	i++;
126	return devname[i] != entry[i] && entry[i] != 1;
127	}
128
129	/* process standard matches */
130	static inline int
131	ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb,
132	const struct net_device *in, const struct net_device *out)
133	{
134	const struct ethhdr *h = eth_hdr(skb);
135	const struct net_bridge_port *p;
136	__be16 ethproto;
137
138	if (skb_vlan_tag_present(skb))
139	ethproto = htons(ETH_P_8021Q);
140	else
141	ethproto = h->h_proto;
142
143	if (e->bitmask & EBT_802_3) {
144	if (NF_INVF(e, EBT_IPROTO, eth_proto_is_802_3(ethproto)))
145	return 1;
146	} else if (!(e->bitmask & EBT_NOPROTO) &&
147	NF_INVF(e, EBT_IPROTO, e->ethproto != ethproto))
148	return 1;
149
150	if (NF_INVF(e, EBT_IIN, ebt_dev_check(e->in, in)))
151	return 1;
152	if (NF_INVF(e, EBT_IOUT, ebt_dev_check(e->out, out)))
153	return 1;
154	/* rcu_read_lock()ed by nf_hook_thresh */
155	if (in && (p = br_port_get_rcu(dev: in)) != NULL &&
156	NF_INVF(e, EBT_ILOGICALIN,
157	ebt_dev_check(e->logical_in, p->br->dev)))
158	return 1;
159	if (out && (p = br_port_get_rcu(dev: out)) != NULL &&
160	NF_INVF(e, EBT_ILOGICALOUT,
161	ebt_dev_check(e->logical_out, p->br->dev)))
162	return 1;
163
164	if (e->bitmask & EBT_SOURCEMAC) {
165	if (NF_INVF(e, EBT_ISOURCE,
166	!ether_addr_equal_masked(h->h_source, e->sourcemac,
167	e->sourcemsk)))
168	return 1;
169	}
170	if (e->bitmask & EBT_DESTMAC) {
171	if (NF_INVF(e, EBT_IDEST,
172	!ether_addr_equal_masked(h->h_dest, e->destmac,
173	e->destmsk)))
174	return 1;
175	}
176	return 0;
177	}
178
179	static inline
180	struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry)
181	{
182	return (void *)entry + entry->next_offset;
183	}
184
185	static inline const struct ebt_entry_target *
186	ebt_get_target_c(const struct ebt_entry *e)
187	{
188	return ebt_get_target(e: (struct ebt_entry *)e);
189	}
190
191	/* Do some firewalling */
192	unsigned int ebt_do_table(void *priv, struct sk_buff *skb,
193	const struct nf_hook_state *state)
194	{
195	struct ebt_table *table = priv;
196	unsigned int hook = state->hook;
197	int i, nentries;
198	struct ebt_entry *point;
199	struct ebt_counter *counter_base, *cb_base;
200	const struct ebt_entry_target *t;
201	int verdict, sp = 0;
202	struct ebt_chainstack *cs;
203	struct ebt_entries *chaininfo;
204	const char *base;
205	const struct ebt_table_info *private;
206	struct xt_action_param acpar;
207
208	acpar.state = state;
209	acpar.hotdrop = false;
210
211	read_lock_bh(&table->lock);
212	private = table->private;
213	cb_base = COUNTER_BASE(private->counters, private->nentries,
214	smp_processor_id());
215	if (private->chainstack)
216	cs = private->chainstack[smp_processor_id()];
217	else
218	cs = NULL;
219	chaininfo = private->hook_entry[hook];
220	nentries = private->hook_entry[hook]->nentries;
221	point = (struct ebt_entry *)(private->hook_entry[hook]->data);
222	counter_base = cb_base + private->hook_entry[hook]->counter_offset;
223	/* base for chain jumps */
224	base = private->entries;
225	i = 0;
226	while (i < nentries) {
227	if (ebt_basic_match(e: point, skb, in: state->in, out: state->out))
228	goto letscontinue;
229
230	if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0)
231	goto letscontinue;
232	if (acpar.hotdrop) {
233	read_unlock_bh(&table->lock);
234	return NF_DROP;
235	}
236
237	ADD_COUNTER(*(counter_base + i), skb->len, 1);
238
239	/* these should only watch: not modify, nor tell us
240	* what to do with the packet
241	*/
242	EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar);
243
244	t = ebt_get_target_c(e: point);
245	/* standard target */
246	if (!t->u.target->target)
247	verdict = ((struct ebt_standard_target *)t)->verdict;
248	else {
249	acpar.target = t->u.target;
250	acpar.targinfo = t->data;
251	verdict = t->u.target->target(skb, &acpar);
252	}
253	if (verdict == EBT_ACCEPT) {
254	read_unlock_bh(&table->lock);
255	return NF_ACCEPT;
256	}
257	if (verdict == EBT_DROP) {
258	read_unlock_bh(&table->lock);
259	return NF_DROP;
260	}
261	if (verdict == EBT_RETURN) {
262	letsreturn:
263	if (WARN(sp == 0, "RETURN on base chain")) {
264	/* act like this is EBT_CONTINUE */
265	goto letscontinue;
266	}
267
268	sp--;
269	/* put all the local variables right */
270	i = cs[sp].n;
271	chaininfo = cs[sp].chaininfo;
272	nentries = chaininfo->nentries;
273	point = cs[sp].e;
274	counter_base = cb_base +
275	chaininfo->counter_offset;
276	continue;
277	}
278	if (verdict == EBT_CONTINUE)
279	goto letscontinue;
280
281	if (WARN(verdict < 0, "bogus standard verdict\n")) {
282	read_unlock_bh(&table->lock);
283	return NF_DROP;
284	}
285
286	/* jump to a udc */
287	cs[sp].n = i + 1;
288	cs[sp].chaininfo = chaininfo;
289	cs[sp].e = ebt_next_entry(entry: point);
290	i = 0;
291	chaininfo = (struct ebt_entries *) (base + verdict);
292
293	if (WARN(chaininfo->distinguisher, "jump to non-chain\n")) {
294	read_unlock_bh(&table->lock);
295	return NF_DROP;
296	}
297
298	nentries = chaininfo->nentries;
299	point = (struct ebt_entry *)chaininfo->data;
300	counter_base = cb_base + chaininfo->counter_offset;
301	sp++;
302	continue;
303	letscontinue:
304	point = ebt_next_entry(entry: point);
305	i++;
306	}
307
308	/* I actually like this :) */
309	if (chaininfo->policy == EBT_RETURN)
310	goto letsreturn;
311	if (chaininfo->policy == EBT_ACCEPT) {
312	read_unlock_bh(&table->lock);
313	return NF_ACCEPT;
314	}
315	read_unlock_bh(&table->lock);
316	return NF_DROP;
317	}
318
319	/* If it succeeds, returns element and locks mutex */
320	static inline void *
321	find_inlist_lock_noload(struct net *net, const char *name, int *error,
322	struct mutex *mutex)
323	{
324	struct ebt_pernet *ebt_net = net_generic(net, id: ebt_pernet_id);
325	struct ebt_template *tmpl;
326	struct ebt_table *table;
327
328	mutex_lock(mutex);
329	list_for_each_entry(table, &ebt_net->tables, list) {
330	if (strcmp(table->name, name) == 0)
331	return table;
332	}
333
334	list_for_each_entry(tmpl, &template_tables, list) {
335	if (strcmp(name, tmpl->name) == 0) {
336	struct module *owner = tmpl->owner;
337
338	if (!try_module_get(module: owner))
339	goto out;
340
341	mutex_unlock(lock: mutex);
342
343	*error = tmpl->table_init(net);
344	if (*error) {
345	module_put(module: owner);
346	return NULL;
347	}
348
349	mutex_lock(mutex);
350	module_put(module: owner);
351	break;
352	}
353	}
354
355	list_for_each_entry(table, &ebt_net->tables, list) {
356	if (strcmp(table->name, name) == 0)
357	return table;
358	}
359
360	out:
361	*error = -ENOENT;
362	mutex_unlock(lock: mutex);
363	return NULL;
364	}
365
366	static void *
367	find_inlist_lock(struct net *net, const char *name, const char *prefix,
368	int *error, struct mutex *mutex)
369	{
370	return try_then_request_module(
371	find_inlist_lock_noload(net, name, error, mutex),
372	"%s%s", prefix, name);
373	}
374
375	static inline struct ebt_table *
376	find_table_lock(struct net *net, const char *name, int *error,
377	struct mutex *mutex)
378	{
379	return find_inlist_lock(net, name, prefix: "ebtable_", error, mutex);
380	}
381
382	static inline void ebt_free_table_info(struct ebt_table_info *info)
383	{
384	int i;
385
386	if (info->chainstack) {
387	for_each_possible_cpu(i)
388	vfree(addr: info->chainstack[i]);
389	vfree(addr: info->chainstack);
390	}
391	}
392	static inline int
393	ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
394	unsigned int *cnt)
395	{
396	const struct ebt_entry *e = par->entryinfo;
397	struct xt_match *match;
398	size_t left = ((char *)e + e->watchers_offset) - (char *)m;
399	int ret;
400
401	if (left < sizeof(struct ebt_entry_match) ||
402	left - sizeof(struct ebt_entry_match) < m->match_size)
403	return -EINVAL;
404
405	match = xt_find_match(af: NFPROTO_BRIDGE, name: m->u.name, revision: m->u.revision);
406	if (IS_ERR(ptr: match) || match->family != NFPROTO_BRIDGE) {
407	if (!IS_ERR(ptr: match))
408	module_put(module: match->me);
409	request_module("ebt_%s", m->u.name);
410	match = xt_find_match(af: NFPROTO_BRIDGE, name: m->u.name, revision: m->u.revision);
411	}
412	if (IS_ERR(ptr: match))
413	return PTR_ERR(ptr: match);
414	m->u.match = match;
415
416	par->match = match;
417	par->matchinfo = m->data;
418	ret = xt_check_match(par, size: m->match_size,
419	ntohs(e->ethproto), inv_proto: e->invflags & EBT_IPROTO);
420	if (ret < 0) {
421	module_put(module: match->me);
422	return ret;
423	}
424
425	(*cnt)++;
426	return 0;
427	}
428
429	static inline int
430	ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
431	unsigned int *cnt)
432	{
433	const struct ebt_entry *e = par->entryinfo;
434	struct xt_target *watcher;
435	size_t left = ((char *)e + e->target_offset) - (char *)w;
436	int ret;
437
438	if (left < sizeof(struct ebt_entry_watcher) ||
439	left - sizeof(struct ebt_entry_watcher) < w->watcher_size)
440	return -EINVAL;
441
442	watcher = xt_request_find_target(af: NFPROTO_BRIDGE, name: w->u.name, revision: 0);
443	if (IS_ERR(ptr: watcher))
444	return PTR_ERR(ptr: watcher);
445
446	if (watcher->family != NFPROTO_BRIDGE) {
447	module_put(module: watcher->me);
448	return -ENOENT;
449	}
450
451	w->u.watcher = watcher;
452
453	par->target = watcher;
454	par->targinfo = w->data;
455	ret = xt_check_target(par, size: w->watcher_size,
456	ntohs(e->ethproto), inv_proto: e->invflags & EBT_IPROTO);
457	if (ret < 0) {
458	module_put(module: watcher->me);
459	return ret;
460	}
461
462	(*cnt)++;
463	return 0;
464	}
465
466	static int ebt_verify_pointers(const struct ebt_replace *repl,
467	struct ebt_table_info *newinfo)
468	{
469	unsigned int limit = repl->entries_size;
470	unsigned int valid_hooks = repl->valid_hooks;
471	unsigned int offset = 0;
472	int i;
473
474	for (i = 0; i < NF_BR_NUMHOOKS; i++)
475	newinfo->hook_entry[i] = NULL;
476
477	newinfo->entries_size = repl->entries_size;
478	newinfo->nentries = repl->nentries;
479
480	while (offset < limit) {
481	size_t left = limit - offset;
482	struct ebt_entry *e = (void *)newinfo->entries + offset;
483
484	if (left < sizeof(unsigned int))
485	break;
486
487	for (i = 0; i < NF_BR_NUMHOOKS; i++) {
488	if ((valid_hooks & (1 << i)) == 0)
489	continue;
490	if ((char __user *)repl->hook_entry[i] ==
491	repl->entries + offset)
492	break;
493	}
494
495	if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
496	if (e->bitmask != 0) {
497	/* we make userspace set this right,
498	* so there is no misunderstanding
499	*/
500	return -EINVAL;
501	}
502	if (i != NF_BR_NUMHOOKS)
503	newinfo->hook_entry[i] = (struct ebt_entries *)e;
504	if (left < sizeof(struct ebt_entries))
505	break;
506	offset += sizeof(struct ebt_entries);
507	} else {
508	if (left < sizeof(struct ebt_entry))
509	break;
510	if (left < e->next_offset)
511	break;
512	if (e->next_offset < sizeof(struct ebt_entry))
513	return -EINVAL;
514	offset += e->next_offset;
515	}
516	}
517	if (offset != limit)
518	return -EINVAL;
519
520	/* check if all valid hooks have a chain */
521	for (i = 0; i < NF_BR_NUMHOOKS; i++) {
522	if (!newinfo->hook_entry[i] &&
523	(valid_hooks & (1 << i)))
524	return -EINVAL;
525	}
526	return 0;
527	}
528
529	/* this one is very careful, as it is the first function
530	* to parse the userspace data
531	*/
532	static inline int
533	ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
534	const struct ebt_table_info *newinfo,
535	unsigned int *n, unsigned int *cnt,
536	unsigned int *totalcnt, unsigned int *udc_cnt)
537	{
538	int i;
539
540	for (i = 0; i < NF_BR_NUMHOOKS; i++) {
541	if ((void *)e == (void *)newinfo->hook_entry[i])
542	break;
543	}
544	/* beginning of a new chain
545	* if i == NF_BR_NUMHOOKS it must be a user defined chain
546	*/
547	if (i != NF_BR_NUMHOOKS || !e->bitmask) {
548	/* this checks if the previous chain has as many entries
549	* as it said it has
550	*/
551	if (*n != *cnt)
552	return -EINVAL;
553
554	if (((struct ebt_entries *)e)->policy != EBT_DROP &&
555	((struct ebt_entries *)e)->policy != EBT_ACCEPT) {
556	/* only RETURN from udc */
557	if (i != NF_BR_NUMHOOKS ||
558	((struct ebt_entries *)e)->policy != EBT_RETURN)
559	return -EINVAL;
560	}
561	if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */
562	(*udc_cnt)++;
563	if (((struct ebt_entries *)e)->counter_offset != *totalcnt)
564	return -EINVAL;
565	*n = ((struct ebt_entries *)e)->nentries;
566	*cnt = 0;
567	return 0;
568	}
569	/* a plain old entry, heh */
570	if (sizeof(struct ebt_entry) > e->watchers_offset ||
571	e->watchers_offset > e->target_offset ||
572	e->target_offset >= e->next_offset)
573	return -EINVAL;
574
575	/* this is not checked anywhere else */
576	if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target))
577	return -EINVAL;
578
579	(*cnt)++;
580	(*totalcnt)++;
581	return 0;
582	}
583
584	struct ebt_cl_stack {
585	struct ebt_chainstack cs;
586	int from;
587	unsigned int hookmask;
588	};
589
590	/* We need these positions to check that the jumps to a different part of the
591	* entries is a jump to the beginning of a new chain.
592	*/
593	static inline int
594	ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo,
595	unsigned int *n, struct ebt_cl_stack *udc)
596	{
597	int i;
598
599	/* we're only interested in chain starts */
600	if (e->bitmask)
601	return 0;
602	for (i = 0; i < NF_BR_NUMHOOKS; i++) {
603	if (newinfo->hook_entry[i] == (struct ebt_entries *)e)
604	break;
605	}
606	/* only care about udc */
607	if (i != NF_BR_NUMHOOKS)
608	return 0;
609
610	udc[*n].cs.chaininfo = (struct ebt_entries *)e;
611	/* these initialisations are depended on later in check_chainloops() */
612	udc[*n].cs.n = 0;
613	udc[*n].hookmask = 0;
614
615	(*n)++;
616	return 0;
617	}
618
619	static inline int
620	ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i)
621	{
622	struct xt_mtdtor_param par;
623
624	if (i && (*i)-- == 0)
625	return 1;
626
627	par.net = net;
628	par.match = m->u.match;
629	par.matchinfo = m->data;
630	par.family = NFPROTO_BRIDGE;
631	if (par.match->destroy != NULL)
632	par.match->destroy(&par);
633	module_put(module: par.match->me);
634	return 0;
635	}
636
637	static inline int
638	ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i)
639	{
640	struct xt_tgdtor_param par;
641
642	if (i && (*i)-- == 0)
643	return 1;
644
645	par.net = net;
646	par.target = w->u.watcher;
647	par.targinfo = w->data;
648	par.family = NFPROTO_BRIDGE;
649	if (par.target->destroy != NULL)
650	par.target->destroy(&par);
651	module_put(module: par.target->me);
652	return 0;
653	}
654
655	static inline int
656	ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
657	{
658	struct xt_tgdtor_param par;
659	struct ebt_entry_target *t;
660
661	if (e->bitmask == 0)
662	return 0;
663	/* we're done */
664	if (cnt && (*cnt)-- == 0)
665	return 1;
666	EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL);
667	EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL);
668	t = ebt_get_target(e);
669
670	par.net = net;
671	par.target = t->u.target;
672	par.targinfo = t->data;
673	par.family = NFPROTO_BRIDGE;
674	if (par.target->destroy != NULL)
675	par.target->destroy(&par);
676	module_put(module: par.target->me);
677	return 0;
678	}
679
680	static inline int
681	ebt_check_entry(struct ebt_entry *e, struct net *net,
682	const struct ebt_table_info *newinfo,
683	const char *name, unsigned int *cnt,
684	struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
685	{
686	struct ebt_entry_target *t;
687	struct xt_target *target;
688	unsigned int i, j, hook = 0, hookmask = 0;
689	size_t gap;
690	int ret;
691	struct xt_mtchk_param mtpar;
692	struct xt_tgchk_param tgpar;
693
694	/* don't mess with the struct ebt_entries */
695	if (e->bitmask == 0)
696	return 0;
697
698	if (e->bitmask & ~EBT_F_MASK)
699	return -EINVAL;
700
701	if (e->invflags & ~EBT_INV_MASK)
702	return -EINVAL;
703
704	if ((e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3))
705	return -EINVAL;
706
707	/* what hook do we belong to? */
708	for (i = 0; i < NF_BR_NUMHOOKS; i++) {
709	if (!newinfo->hook_entry[i])
710	continue;
711	if ((char *)newinfo->hook_entry[i] < (char *)e)
712	hook = i;
713	else
714	break;
715	}
716	/* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on
717	* a base chain
718	*/
719	if (i < NF_BR_NUMHOOKS)
720	hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
721	else {
722	for (i = 0; i < udc_cnt; i++)
723	if ((char *)(cl_s[i].cs.chaininfo) > (char *)e)
724	break;
725	if (i == 0)
726	hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
727	else
728	hookmask = cl_s[i - 1].hookmask;
729	}
730	i = 0;
731
732	memset(&mtpar, 0, sizeof(mtpar));
733	memset(&tgpar, 0, sizeof(tgpar));
734	mtpar.net = tgpar.net = net;
735	mtpar.table = tgpar.table = name;
736	mtpar.entryinfo = tgpar.entryinfo = e;
737	mtpar.hook_mask = tgpar.hook_mask = hookmask;
738	mtpar.family = tgpar.family = NFPROTO_BRIDGE;
739	ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i);
740	if (ret != 0)
741	goto cleanup_matches;
742	j = 0;
743	ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j);
744	if (ret != 0)
745	goto cleanup_watchers;
746	t = ebt_get_target(e);
747	gap = e->next_offset - e->target_offset;
748
749	target = xt_request_find_target(af: NFPROTO_BRIDGE, name: t->u.name, revision: 0);
750	if (IS_ERR(ptr: target)) {
751	ret = PTR_ERR(ptr: target);
752	goto cleanup_watchers;
753	}
754
755	/* Reject UNSPEC, xtables verdicts/return values are incompatible */
756	if (target->family != NFPROTO_BRIDGE) {
757	module_put(module: target->me);
758	ret = -ENOENT;
759	goto cleanup_watchers;
760	}
761
762	t->u.target = target;
763	if (t->u.target == &ebt_standard_target) {
764	if (gap < sizeof(struct ebt_standard_target)) {
765	ret = -EFAULT;
766	goto cleanup_watchers;
767	}
768	if (((struct ebt_standard_target *)t)->verdict <
769	-NUM_STANDARD_TARGETS) {
770	ret = -EFAULT;
771	goto cleanup_watchers;
772	}
773	} else if (t->target_size > gap - sizeof(struct ebt_entry_target)) {
774	module_put(module: t->u.target->me);
775	ret = -EFAULT;
776	goto cleanup_watchers;
777	}
778
779	tgpar.target = target;
780	tgpar.targinfo = t->data;
781	ret = xt_check_target(&tgpar, size: t->target_size,
782	ntohs(e->ethproto), inv_proto: e->invflags & EBT_IPROTO);
783	if (ret < 0) {
784	module_put(module: target->me);
785	goto cleanup_watchers;
786	}
787	(*cnt)++;
788	return 0;
789	cleanup_watchers:
790	EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j);
791	cleanup_matches:
792	EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i);
793	return ret;
794	}
795
796	/* checks for loops and sets the hook mask for udc
797	* the hook mask for udc tells us from which base chains the udc can be
798	* accessed. This mask is a parameter to the check() functions of the extensions
799	*/
800	static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
801	unsigned int udc_cnt, unsigned int hooknr, char *base)
802	{
803	int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
804	const struct ebt_entry *e = (struct ebt_entry *)chain->data;
805	const struct ebt_entry_target *t;
806
807	while (pos < nentries || chain_nr != -1) {
808	/* end of udc, go back one 'recursion' step */
809	if (pos == nentries) {
810	/* put back values of the time when this chain was called */
811	e = cl_s[chain_nr].cs.e;
812	if (cl_s[chain_nr].from != -1)
813	nentries =
814	cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries;
815	else
816	nentries = chain->nentries;
817	pos = cl_s[chain_nr].cs.n;
818	/* make sure we won't see a loop that isn't one */
819	cl_s[chain_nr].cs.n = 0;
820	chain_nr = cl_s[chain_nr].from;
821	if (pos == nentries)
822	continue;
823	}
824	t = ebt_get_target_c(e);
825	if (strcmp(t->u.name, EBT_STANDARD_TARGET))
826	goto letscontinue;
827	if (e->target_offset + sizeof(struct ebt_standard_target) >
828	e->next_offset)
829	return -1;
830
831	verdict = ((struct ebt_standard_target *)t)->verdict;
832	if (verdict >= 0) { /* jump to another chain */
833	struct ebt_entries *hlp2 =
834	(struct ebt_entries *)(base + verdict);
835	for (i = 0; i < udc_cnt; i++)
836	if (hlp2 == cl_s[i].cs.chaininfo)
837	break;
838	/* bad destination or loop */
839	if (i == udc_cnt)
840	return -1;
841
842	if (cl_s[i].cs.n)
843	return -1;
844
845	if (cl_s[i].hookmask & (1 << hooknr))
846	goto letscontinue;
847	/* this can't be 0, so the loop test is correct */
848	cl_s[i].cs.n = pos + 1;
849	pos = 0;
850	cl_s[i].cs.e = ebt_next_entry(entry: e);
851	e = (struct ebt_entry *)(hlp2->data);
852	nentries = hlp2->nentries;
853	cl_s[i].from = chain_nr;
854	chain_nr = i;
855	/* this udc is accessible from the base chain for hooknr */
856	cl_s[i].hookmask |= (1 << hooknr);
857	continue;
858	}
859	letscontinue:
860	e = ebt_next_entry(entry: e);
861	pos++;
862	}
863	return 0;
864	}
865
866	/* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
867	static int translate_table(struct net *net, const char *name,
868	struct ebt_table_info *newinfo)
869	{
870	unsigned int i, j, k, udc_cnt;
871	int ret;
872	struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */
873
874	i = 0;
875	while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i])
876	i++;
877	if (i == NF_BR_NUMHOOKS)
878	return -EINVAL;
879
880	if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries)
881	return -EINVAL;
882
883	/* make sure chains are ordered after each other in same order
884	* as their corresponding hooks
885	*/
886	for (j = i + 1; j < NF_BR_NUMHOOKS; j++) {
887	if (!newinfo->hook_entry[j])
888	continue;
889	if (newinfo->hook_entry[j] <= newinfo->hook_entry[i])
890	return -EINVAL;
891
892	i = j;
893	}
894
895	/* do some early checkings and initialize some things */
896	i = 0; /* holds the expected nr. of entries for the chain */
897	j = 0; /* holds the up to now counted entries for the chain */
898	k = 0; /* holds the total nr. of entries, should equal
899	* newinfo->nentries afterwards
900	*/
901	udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */
902	ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
903	ebt_check_entry_size_and_hooks, newinfo,
904	&i, &j, &k, &udc_cnt);
905
906	if (ret != 0)
907	return ret;
908
909	if (i != j)
910	return -EINVAL;
911
912	if (k != newinfo->nentries)
913	return -EINVAL;
914
915	/* get the location of the udc, put them in an array
916	* while we're at it, allocate the chainstack
917	*/
918	if (udc_cnt) {
919	/* this will get free'd in do_replace()/ebt_register_table()
920	* if an error occurs
921	*/
922	newinfo->chainstack =
923	vmalloc(array_size(nr_cpu_ids,
924	sizeof(*(newinfo->chainstack))));
925	if (!newinfo->chainstack)
926	return -ENOMEM;
927	for_each_possible_cpu(i) {
928	newinfo->chainstack[i] =
929	vmalloc_node(array_size(udc_cnt,
930	sizeof(*(newinfo->chainstack[0]))),
931	cpu_to_node(cpu: i));
932	if (!newinfo->chainstack[i]) {
933	while (i)
934	vfree(addr: newinfo->chainstack[--i]);
935	vfree(addr: newinfo->chainstack);
936	newinfo->chainstack = NULL;
937	return -ENOMEM;
938	}
939	}
940
941	cl_s = vmalloc(array_size(udc_cnt, sizeof(*cl_s)));
942	if (!cl_s)
943	return -ENOMEM;
944	i = 0; /* the i'th udc */
945	EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
946	ebt_get_udc_positions, newinfo, &i, cl_s);
947	/* sanity check */
948	if (i != udc_cnt) {
949	vfree(addr: cl_s);
950	return -EFAULT;
951	}
952	}
953
954	/* Check for loops */
955	for (i = 0; i < NF_BR_NUMHOOKS; i++)
956	if (newinfo->hook_entry[i])
957	if (check_chainloops(chain: newinfo->hook_entry[i],
958	cl_s, udc_cnt, hooknr: i, base: newinfo->entries)) {
959	vfree(addr: cl_s);
960	return -EINVAL;
961	}
962
963	/* we now know the following (along with E=mc²):
964	* - the nr of entries in each chain is right
965	* - the size of the allocated space is right
966	* - all valid hooks have a corresponding chain
967	* - there are no loops
968	* - wrong data can still be on the level of a single entry
969	* - could be there are jumps to places that are not the
970	* beginning of a chain. This can only occur in chains that
971	* are not accessible from any base chains, so we don't care.
972	*/
973
974	/* used to know what we need to clean up if something goes wrong */
975	i = 0;
976	ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
977	ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt);
978	if (ret != 0) {
979	EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
980	ebt_cleanup_entry, net, &i);
981	}
982	vfree(addr: cl_s);
983	return ret;
984	}
985
986	/* called under write_lock */
987	static void get_counters(const struct ebt_counter *oldcounters,
988	struct ebt_counter *counters, unsigned int nentries)
989	{
990	int i, cpu;
991	struct ebt_counter *counter_base;
992
993	/* counters of cpu 0 */
994	memcpy(counters, oldcounters,
995	sizeof(struct ebt_counter) * nentries);
996
997	/* add other counters to those of cpu 0 */
998	for_each_possible_cpu(cpu) {
999	if (cpu == 0)
1000	continue;
1001	counter_base = COUNTER_BASE(oldcounters, nentries, cpu);
1002	for (i = 0; i < nentries; i++)
1003	ADD_COUNTER(counters[i], counter_base[i].bcnt,
1004	counter_base[i].pcnt);
1005	}
1006	}
1007
1008	static int do_replace_finish(struct net *net, struct ebt_replace *repl,
1009	struct ebt_table_info *newinfo)
1010	{
1011	int ret;
1012	struct ebt_counter *counterstmp = NULL;
1013	/* used to be able to unlock earlier */
1014	struct ebt_table_info *table;
1015	struct ebt_table *t;
1016
1017	/* the user wants counters back
1018	* the check on the size is done later, when we have the lock
1019	*/
1020	if (repl->num_counters) {
1021	unsigned long size = repl->num_counters * sizeof(*counterstmp);
1022	counterstmp = vmalloc(size);
1023	if (!counterstmp)
1024	return -ENOMEM;
1025	}
1026
1027	newinfo->chainstack = NULL;
1028	ret = ebt_verify_pointers(repl, newinfo);
1029	if (ret != 0)
1030	goto free_counterstmp;
1031
1032	ret = translate_table(net, name: repl->name, newinfo);
1033
1034	if (ret != 0)
1035	goto free_counterstmp;
1036
1037	t = find_table_lock(net, name: repl->name, error: &ret, mutex: &ebt_mutex);
1038	if (!t) {
1039	ret = -ENOENT;
1040	goto free_iterate;
1041	}
1042
1043	if (repl->valid_hooks != t->valid_hooks) {
1044	ret = -EINVAL;
1045	goto free_unlock;
1046	}
1047
1048	if (repl->num_counters && repl->num_counters != t->private->nentries) {
1049	ret = -EINVAL;
1050	goto free_unlock;
1051	}
1052
1053	/* we have the mutex lock, so no danger in reading this pointer */
1054	table = t->private;
1055	/* make sure the table can only be rmmod'ed if it contains no rules */
1056	if (!table->nentries && newinfo->nentries && !try_module_get(module: t->me)) {
1057	ret = -ENOENT;
1058	goto free_unlock;
1059	} else if (table->nentries && !newinfo->nentries)
1060	module_put(module: t->me);
1061	/* we need an atomic snapshot of the counters */
1062	write_lock_bh(&t->lock);
1063	if (repl->num_counters)
1064	get_counters(oldcounters: t->private->counters, counters: counterstmp,
1065	nentries: t->private->nentries);
1066
1067	t->private = newinfo;
1068	write_unlock_bh(&t->lock);
1069	mutex_unlock(lock: &ebt_mutex);
1070	/* so, a user can change the chains while having messed up her counter
1071	* allocation. Only reason why this is done is because this way the lock
1072	* is held only once, while this doesn't bring the kernel into a
1073	* dangerous state.
1074	*/
1075	if (repl->num_counters &&
1076	copy_to_user(to: repl->counters, from: counterstmp,
1077	array_size(repl->num_counters, sizeof(struct ebt_counter)))) {
1078	/* Silent error, can't fail, new table is already in place */
1079	net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n");
1080	}
1081
1082	/* decrease module count and free resources */
1083	EBT_ENTRY_ITERATE(table->entries, table->entries_size,
1084	ebt_cleanup_entry, net, NULL);
1085
1086	vfree(addr: table->entries);
1087	ebt_free_table_info(info: table);
1088	vfree(addr: table);
1089	vfree(addr: counterstmp);
1090
1091	audit_log_nfcfg(name: repl->name, AF_BRIDGE, nentries: repl->nentries,
1092	op: AUDIT_XT_OP_REPLACE, GFP_KERNEL);
1093	return 0;
1094
1095	free_unlock:
1096	mutex_unlock(lock: &ebt_mutex);
1097	free_iterate:
1098	EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
1099	ebt_cleanup_entry, net, NULL);
1100	free_counterstmp:
1101	vfree(addr: counterstmp);
1102	/* can be initialized in translate_table() */
1103	ebt_free_table_info(info: newinfo);
1104	return ret;
1105	}
1106
1107	/* replace the table */
1108	static int do_replace(struct net *net, sockptr_t arg, unsigned int len)
1109	{
1110	int ret, countersize;
1111	struct ebt_table_info *newinfo;
1112	struct ebt_replace tmp;
1113
1114	if (len < sizeof(tmp))
1115	return -EINVAL;
1116	if (copy_from_sockptr(dst: &tmp, src: arg, size: sizeof(tmp)) != 0)
1117	return -EFAULT;
1118
1119	if (len != sizeof(tmp) + tmp.entries_size)
1120	return -EINVAL;
1121
1122	if (tmp.entries_size == 0)
1123	return -EINVAL;
1124
1125	/* overflow check */
1126	if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
1127	NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
1128	return -ENOMEM;
1129	if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
1130	return -ENOMEM;
1131
1132	tmp.name[sizeof(tmp.name) - 1] = 0;
1133
1134	countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
1135	newinfo = __vmalloc(size: sizeof(*newinfo) + countersize, GFP_KERNEL_ACCOUNT);
1136	if (!newinfo)
1137	return -ENOMEM;
1138
1139	if (countersize)
1140	memset(newinfo->counters, 0, countersize);
1141
1142	newinfo->entries = __vmalloc(size: tmp.entries_size, GFP_KERNEL_ACCOUNT);
1143	if (!newinfo->entries) {
1144	ret = -ENOMEM;
1145	goto free_newinfo;
1146	}
1147	if (copy_from_user(
1148	to: newinfo->entries, from: tmp.entries, n: tmp.entries_size) != 0) {
1149	ret = -EFAULT;
1150	goto free_entries;
1151	}
1152
1153	ret = do_replace_finish(net, repl: &tmp, newinfo);
1154	if (ret == 0)
1155	return ret;
1156	free_entries:
1157	vfree(addr: newinfo->entries);
1158	free_newinfo:
1159	vfree(addr: newinfo);
1160	return ret;
1161	}
1162
1163	static void __ebt_unregister_table(struct net *net, struct ebt_table *table)
1164	{
1165	mutex_lock(&ebt_mutex);
1166	list_del(entry: &table->list);
1167	mutex_unlock(lock: &ebt_mutex);
1168	audit_log_nfcfg(name: table->name, AF_BRIDGE, nentries: table->private->nentries,
1169	op: AUDIT_XT_OP_UNREGISTER, GFP_KERNEL);
1170	EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
1171	ebt_cleanup_entry, net, NULL);
1172	if (table->private->nentries)
1173	module_put(module: table->me);
1174	vfree(addr: table->private->entries);
1175	ebt_free_table_info(info: table->private);
1176	vfree(addr: table->private);
1177	kfree(objp: table->ops);
1178	kfree(objp: table);
1179	}
1180
1181	int ebt_register_table(struct net *net, const struct ebt_table *input_table,
1182	const struct nf_hook_ops *template_ops)
1183	{
1184	struct ebt_pernet *ebt_net = net_generic(net, id: ebt_pernet_id);
1185	struct ebt_table_info *newinfo;
1186	struct ebt_table *t, *table;
1187	struct nf_hook_ops *ops;
1188	unsigned int num_ops;
1189	struct ebt_replace_kernel *repl;
1190	int ret, i, countersize;
1191	void *p;
1192
1193	if (input_table == NULL || (repl = input_table->table) == NULL ||
1194	repl->entries == NULL || repl->entries_size == 0 ||
1195	repl->counters != NULL || input_table->private != NULL)
1196	return -EINVAL;
1197
1198	/* Don't add one table to multiple lists. */
1199	table = kmemdup(p: input_table, size: sizeof(struct ebt_table), GFP_KERNEL);
1200	if (!table) {
1201	ret = -ENOMEM;
1202	goto out;
1203	}
1204
1205	countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
1206	newinfo = vmalloc(size: sizeof(*newinfo) + countersize);
1207	ret = -ENOMEM;
1208	if (!newinfo)
1209	goto free_table;
1210
1211	p = vmalloc(size: repl->entries_size);
1212	if (!p)
1213	goto free_newinfo;
1214
1215	memcpy(p, repl->entries, repl->entries_size);
1216	newinfo->entries = p;
1217
1218	newinfo->entries_size = repl->entries_size;
1219	newinfo->nentries = repl->nentries;
1220
1221	if (countersize)
1222	memset(newinfo->counters, 0, countersize);
1223
1224	/* fill in newinfo and parse the entries */
1225	newinfo->chainstack = NULL;
1226	for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1227	if ((repl->valid_hooks & (1 << i)) == 0)
1228	newinfo->hook_entry[i] = NULL;
1229	else
1230	newinfo->hook_entry[i] = p +
1231	((char *)repl->hook_entry[i] - repl->entries);
1232	}
1233	ret = translate_table(net, name: repl->name, newinfo);
1234	if (ret != 0)
1235	goto free_chainstack;
1236
1237	table->private = newinfo;
1238	rwlock_init(&table->lock);
1239	mutex_lock(&ebt_mutex);
1240	list_for_each_entry(t, &ebt_net->tables, list) {
1241	if (strcmp(t->name, table->name) == 0) {
1242	ret = -EEXIST;
1243	goto free_unlock;
1244	}
1245	}
1246
1247	/* Hold a reference count if the chains aren't empty */
1248	if (newinfo->nentries && !try_module_get(module: table->me)) {
1249	ret = -ENOENT;
1250	goto free_unlock;
1251	}
1252
1253	num_ops = hweight32(table->valid_hooks);
1254	if (num_ops == 0) {
1255	ret = -EINVAL;
1256	goto free_unlock;
1257	}
1258
1259	ops = kmemdup(p: template_ops, size: sizeof(*ops) * num_ops, GFP_KERNEL);
1260	if (!ops) {
1261	ret = -ENOMEM;
1262	if (newinfo->nentries)
1263	module_put(module: table->me);
1264	goto free_unlock;
1265	}
1266
1267	for (i = 0; i < num_ops; i++)
1268	ops[i].priv = table;
1269
1270	list_add(new: &table->list, head: &ebt_net->tables);
1271	mutex_unlock(lock: &ebt_mutex);
1272
1273	table->ops = ops;
1274	ret = nf_register_net_hooks(net, reg: ops, n: num_ops);
1275	if (ret)
1276	__ebt_unregister_table(net, table);
1277
1278	audit_log_nfcfg(name: repl->name, AF_BRIDGE, nentries: repl->nentries,
1279	op: AUDIT_XT_OP_REGISTER, GFP_KERNEL);
1280	return ret;
1281	free_unlock:
1282	mutex_unlock(lock: &ebt_mutex);
1283	free_chainstack:
1284	ebt_free_table_info(info: newinfo);
1285	vfree(addr: newinfo->entries);
1286	free_newinfo:
1287	vfree(addr: newinfo);
1288	free_table:
1289	kfree(objp: table);
1290	out:
1291	return ret;
1292	}
1293
1294	int ebt_register_template(const struct ebt_table *t, int (*table_init)(struct net *net))
1295	{
1296	struct ebt_template *tmpl;
1297
1298	mutex_lock(&ebt_mutex);
1299	list_for_each_entry(tmpl, &template_tables, list) {
1300	if (WARN_ON_ONCE(strcmp(t->name, tmpl->name) == 0)) {
1301	mutex_unlock(lock: &ebt_mutex);
1302	return -EEXIST;
1303	}
1304	}
1305
1306	tmpl = kzalloc(size: sizeof(*tmpl), GFP_KERNEL);
1307	if (!tmpl) {
1308	mutex_unlock(lock: &ebt_mutex);
1309	return -ENOMEM;
1310	}
1311
1312	tmpl->table_init = table_init;
1313	strscpy(tmpl->name, t->name, sizeof(tmpl->name));
1314	tmpl->owner = t->me;
1315	list_add(new: &tmpl->list, head: &template_tables);
1316
1317	mutex_unlock(lock: &ebt_mutex);
1318	return 0;
1319	}
1320	EXPORT_SYMBOL(ebt_register_template);
1321
1322	void ebt_unregister_template(const struct ebt_table *t)
1323	{
1324	struct ebt_template *tmpl;
1325
1326	mutex_lock(&ebt_mutex);
1327	list_for_each_entry(tmpl, &template_tables, list) {
1328	if (strcmp(t->name, tmpl->name))
1329	continue;
1330
1331	list_del(entry: &tmpl->list);
1332	mutex_unlock(lock: &ebt_mutex);
1333	kfree(objp: tmpl);
1334	return;
1335	}
1336
1337	mutex_unlock(lock: &ebt_mutex);
1338	WARN_ON_ONCE(1);
1339	}
1340	EXPORT_SYMBOL(ebt_unregister_template);
1341
1342	static struct ebt_table *__ebt_find_table(struct net *net, const char *name)
1343	{
1344	struct ebt_pernet *ebt_net = net_generic(net, id: ebt_pernet_id);
1345	struct ebt_table *t;
1346
1347	mutex_lock(&ebt_mutex);
1348
1349	list_for_each_entry(t, &ebt_net->tables, list) {
1350	if (strcmp(t->name, name) == 0) {
1351	mutex_unlock(lock: &ebt_mutex);
1352	return t;
1353	}
1354	}
1355
1356	mutex_unlock(lock: &ebt_mutex);
1357	return NULL;
1358	}
1359
1360	void ebt_unregister_table_pre_exit(struct net *net, const char *name)
1361	{
1362	struct ebt_table *table = __ebt_find_table(net, name);
1363
1364	if (table)
1365	nf_unregister_net_hooks(net, reg: table->ops, hweight32(table->valid_hooks));
1366	}
1367	EXPORT_SYMBOL(ebt_unregister_table_pre_exit);
1368
1369	void ebt_unregister_table(struct net *net, const char *name)
1370	{
1371	struct ebt_table *table = __ebt_find_table(net, name);
1372
1373	if (table)
1374	__ebt_unregister_table(net, table);
1375	}
1376
1377	/* userspace just supplied us with counters */
1378	static int do_update_counters(struct net *net, const char *name,
1379	struct ebt_counter __user *counters,
1380	unsigned int num_counters, unsigned int len)
1381	{
1382	int i, ret;
1383	struct ebt_counter *tmp;
1384	struct ebt_table *t;
1385
1386	if (num_counters == 0)
1387	return -EINVAL;
1388
1389	tmp = vmalloc(array_size(num_counters, sizeof(*tmp)));
1390	if (!tmp)
1391	return -ENOMEM;
1392
1393	t = find_table_lock(net, name, error: &ret, mutex: &ebt_mutex);
1394	if (!t)
1395	goto free_tmp;
1396
1397	if (num_counters != t->private->nentries) {
1398	ret = -EINVAL;
1399	goto unlock_mutex;
1400	}
1401
1402	if (copy_from_user(to: tmp, from: counters,
1403	array_size(num_counters, sizeof(*counters)))) {
1404	ret = -EFAULT;
1405	goto unlock_mutex;
1406	}
1407
1408	/* we want an atomic add of the counters */
1409	write_lock_bh(&t->lock);
1410
1411	/* we add to the counters of the first cpu */
1412	for (i = 0; i < num_counters; i++)
1413	ADD_COUNTER(t->private->counters[i], tmp[i].bcnt, tmp[i].pcnt);
1414
1415	write_unlock_bh(&t->lock);
1416	ret = 0;
1417	unlock_mutex:
1418	mutex_unlock(lock: &ebt_mutex);
1419	free_tmp:
1420	vfree(addr: tmp);
1421	return ret;
1422	}
1423
1424	static int update_counters(struct net *net, sockptr_t arg, unsigned int len)
1425	{
1426	struct ebt_replace hlp;
1427
1428	if (len < sizeof(hlp))
1429	return -EINVAL;
1430	if (copy_from_sockptr(dst: &hlp, src: arg, size: sizeof(hlp)))
1431	return -EFAULT;
1432
1433	if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
1434	return -EINVAL;
1435
1436	return do_update_counters(net, name: hlp.name, counters: hlp.counters,
1437	num_counters: hlp.num_counters, len);
1438	}
1439
1440	static inline int ebt_obj_to_user(char __user *um, const char *_name,
1441	const char *data, int entrysize,
1442	int usersize, int datasize, u8 revision)
1443	{
1444	char name[EBT_EXTENSION_MAXNAMELEN] = {0};
1445
1446	/* ebtables expects 31 bytes long names but xt_match names are 29 bytes
1447	* long. Copy 29 bytes and fill remaining bytes with zeroes.
1448	*/
1449	strscpy(name, _name, sizeof(name));
1450	if (copy_to_user(to: um, from: name, EBT_EXTENSION_MAXNAMELEN) ||
1451	put_user(revision, (u8 __user *)(um + EBT_EXTENSION_MAXNAMELEN)) ||
1452	put_user(datasize, (int __user *)(um + EBT_EXTENSION_MAXNAMELEN + 1)) ||
1453	xt_data_to_user(dst: um + entrysize, src: data, usersize, size: datasize,
1454	XT_ALIGN(datasize)))
1455	return -EFAULT;
1456
1457	return 0;
1458	}
1459
1460	static inline int ebt_match_to_user(const struct ebt_entry_match *m,
1461	const char *base, char __user *ubase)
1462	{
1463	return ebt_obj_to_user(um: ubase + ((char *)m - base),
1464	name: m->u.match->name, data: m->data, entrysize: sizeof(*m),
1465	usersize: m->u.match->usersize, datasize: m->match_size,
1466	revision: m->u.match->revision);
1467	}
1468
1469	static inline int ebt_watcher_to_user(const struct ebt_entry_watcher *w,
1470	const char *base, char __user *ubase)
1471	{
1472	return ebt_obj_to_user(um: ubase + ((char *)w - base),
1473	name: w->u.watcher->name, data: w->data, entrysize: sizeof(*w),
1474	usersize: w->u.watcher->usersize, datasize: w->watcher_size,
1475	revision: w->u.watcher->revision);
1476	}
1477
1478	static inline int ebt_entry_to_user(struct ebt_entry *e, const char *base,
1479	char __user *ubase)
1480	{
1481	int ret;
1482	char __user *hlp;
1483	const struct ebt_entry_target *t;
1484
1485	if (e->bitmask == 0) {
1486	/* special case !EBT_ENTRY_OR_ENTRIES */
1487	if (copy_to_user(to: ubase + ((char *)e - base), from: e,
1488	n: sizeof(struct ebt_entries)))
1489	return -EFAULT;
1490	return 0;
1491	}
1492
1493	if (copy_to_user(to: ubase + ((char *)e - base), from: e, n: sizeof(*e)))
1494	return -EFAULT;
1495
1496	hlp = ubase + (((char *)e + e->target_offset) - base);
1497	t = ebt_get_target_c(e);
1498
1499	ret = EBT_MATCH_ITERATE(e, ebt_match_to_user, base, ubase);
1500	if (ret != 0)
1501	return ret;
1502	ret = EBT_WATCHER_ITERATE(e, ebt_watcher_to_user, base, ubase);
1503	if (ret != 0)
1504	return ret;
1505	ret = ebt_obj_to_user(um: hlp, name: t->u.target->name, data: t->data, entrysize: sizeof(*t),
1506	usersize: t->u.target->usersize, datasize: t->target_size,
1507	revision: t->u.target->revision);
1508	if (ret != 0)
1509	return ret;
1510
1511	return 0;
1512	}
1513
1514	static int copy_counters_to_user(struct ebt_table *t,
1515	const struct ebt_counter *oldcounters,
1516	void __user *user, unsigned int num_counters,
1517	unsigned int nentries)
1518	{
1519	struct ebt_counter *counterstmp;
1520	int ret = 0;
1521
1522	/* userspace might not need the counters */
1523	if (num_counters == 0)
1524	return 0;
1525
1526	if (num_counters != nentries)
1527	return -EINVAL;
1528
1529	counterstmp = vmalloc(array_size(nentries, sizeof(*counterstmp)));
1530	if (!counterstmp)
1531	return -ENOMEM;
1532
1533	write_lock_bh(&t->lock);
1534	get_counters(oldcounters, counters: counterstmp, nentries);
1535	write_unlock_bh(&t->lock);
1536
1537	if (copy_to_user(to: user, from: counterstmp,
1538	array_size(nentries, sizeof(struct ebt_counter))))
1539	ret = -EFAULT;
1540	vfree(addr: counterstmp);
1541	return ret;
1542	}
1543
1544	/* called with ebt_mutex locked */
1545	static int copy_everything_to_user(struct ebt_table *t, void __user *user,
1546	const int *len, int cmd)
1547	{
1548	struct ebt_replace tmp;
1549	const struct ebt_counter *oldcounters;
1550	unsigned int entries_size, nentries;
1551	int ret;
1552	char *entries;
1553
1554	if (cmd == EBT_SO_GET_ENTRIES) {
1555	entries_size = t->private->entries_size;
1556	nentries = t->private->nentries;
1557	entries = t->private->entries;
1558	oldcounters = t->private->counters;
1559	} else {
1560	entries_size = t->table->entries_size;
1561	nentries = t->table->nentries;
1562	entries = t->table->entries;
1563	oldcounters = t->table->counters;
1564	}
1565
1566	if (copy_from_user(to: &tmp, from: user, n: sizeof(tmp)))
1567	return -EFAULT;
1568
1569	if (*len != sizeof(struct ebt_replace) + entries_size +
1570	(tmp.num_counters ? nentries * sizeof(struct ebt_counter) : 0))
1571	return -EINVAL;
1572
1573	if (tmp.nentries != nentries)
1574	return -EINVAL;
1575
1576	if (tmp.entries_size != entries_size)
1577	return -EINVAL;
1578
1579	ret = copy_counters_to_user(t, oldcounters, user: tmp.counters,
1580	num_counters: tmp.num_counters, nentries);
1581	if (ret)
1582	return ret;
1583
1584	/* set the match/watcher/target names right */
1585	return EBT_ENTRY_ITERATE(entries, entries_size,
1586	ebt_entry_to_user, entries, tmp.entries);
1587	}
1588
1589	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
1590	/* 32 bit-userspace compatibility definitions. */
1591	struct compat_ebt_replace {
1592	char name[EBT_TABLE_MAXNAMELEN];
1593	compat_uint_t valid_hooks;
1594	compat_uint_t nentries;
1595	compat_uint_t entries_size;
1596	/* start of the chains */
1597	compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
1598	/* nr of counters userspace expects back */
1599	compat_uint_t num_counters;
1600	/* where the kernel will put the old counters. */
1601	compat_uptr_t counters;
1602	compat_uptr_t entries;
1603	};
1604
1605	/* struct ebt_entry_match, _target and _watcher have same layout */
1606	struct compat_ebt_entry_mwt {
1607	union {
1608	struct {
1609	char name[EBT_EXTENSION_MAXNAMELEN];
1610	u8 revision;
1611	};
1612	compat_uptr_t ptr;
1613	} u;
1614	compat_uint_t match_size;
1615	compat_uint_t data[] __aligned(__alignof__(struct compat_ebt_replace));
1616	};
1617
1618	/* account for possible padding between match_size and ->data */
1619	static int ebt_compat_entry_padsize(void)
1620	{
1621	BUILD_BUG_ON(sizeof(struct ebt_entry_match) <
1622	sizeof(struct compat_ebt_entry_mwt));
1623	return (int) sizeof(struct ebt_entry_match) -
1624	sizeof(struct compat_ebt_entry_mwt);
1625	}
1626
1627	static int ebt_compat_match_offset(const struct xt_match *match,
1628	unsigned int userlen)
1629	{
1630	/* ebt_among needs special handling. The kernel .matchsize is
1631	* set to -1 at registration time; at runtime an EBT_ALIGN()ed
1632	* value is expected.
1633	* Example: userspace sends 4500, ebt_among.c wants 4504.
1634	*/
1635	if (unlikely(match->matchsize == -1))
1636	return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
1637	return xt_compat_match_offset(match);
1638	}
1639
1640	static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
1641	unsigned int *size)
1642	{
1643	const struct xt_match *match = m->u.match;
1644	struct compat_ebt_entry_mwt __user *cm = *dstptr;
1645	int off = ebt_compat_match_offset(match, userlen: m->match_size);
1646	compat_uint_t msize = m->match_size - off;
1647
1648	if (WARN_ON(off >= m->match_size))
1649	return -EINVAL;
1650
1651	if (copy_to_user(to: cm->u.name, from: match->name, strlen(match->name) + 1) ||
1652	put_user(match->revision, &cm->u.revision) ||
1653	put_user(msize, &cm->match_size))
1654	return -EFAULT;
1655
1656	if (match->compat_to_user) {
1657	if (match->compat_to_user(cm->data, m->data))
1658	return -EFAULT;
1659	} else {
1660	if (xt_data_to_user(dst: cm->data, src: m->data, usersize: match->usersize, size: msize,
1661	COMPAT_XT_ALIGN(msize)))
1662	return -EFAULT;
1663	}
1664
1665	*size -= ebt_compat_entry_padsize() + off;
1666	*dstptr = cm->data;
1667	*dstptr += msize;
1668	return 0;
1669	}
1670
1671	static int compat_target_to_user(struct ebt_entry_target *t,
1672	void __user **dstptr,
1673	unsigned int *size)
1674	{
1675	const struct xt_target *target = t->u.target;
1676	struct compat_ebt_entry_mwt __user *cm = *dstptr;
1677	int off = xt_compat_target_offset(target);
1678	compat_uint_t tsize = t->target_size - off;
1679
1680	if (WARN_ON(off >= t->target_size))
1681	return -EINVAL;
1682
1683	if (copy_to_user(to: cm->u.name, from: target->name, strlen(target->name) + 1) ||
1684	put_user(target->revision, &cm->u.revision) ||
1685	put_user(tsize, &cm->match_size))
1686	return -EFAULT;
1687
1688	if (target->compat_to_user) {
1689	if (target->compat_to_user(cm->data, t->data))
1690	return -EFAULT;
1691	} else {
1692	if (xt_data_to_user(dst: cm->data, src: t->data, usersize: target->usersize, size: tsize,
1693	COMPAT_XT_ALIGN(tsize)))
1694	return -EFAULT;
1695	}
1696
1697	*size -= ebt_compat_entry_padsize() + off;
1698	*dstptr = cm->data;
1699	*dstptr += tsize;
1700	return 0;
1701	}
1702
1703	static int compat_watcher_to_user(struct ebt_entry_watcher *w,
1704	void __user **dstptr,
1705	unsigned int *size)
1706	{
1707	return compat_target_to_user(t: (struct ebt_entry_target *)w,
1708	dstptr, size);
1709	}
1710
1711	static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
1712	unsigned int *size)
1713	{
1714	struct ebt_entry_target *t;
1715	struct ebt_entry __user *ce;
1716	u32 watchers_offset, target_offset, next_offset;
1717	compat_uint_t origsize;
1718	int ret;
1719
1720	if (e->bitmask == 0) {
1721	if (*size < sizeof(struct ebt_entries))
1722	return -EINVAL;
1723	if (copy_to_user(to: *dstptr, from: e, n: sizeof(struct ebt_entries)))
1724	return -EFAULT;
1725
1726	*dstptr += sizeof(struct ebt_entries);
1727	*size -= sizeof(struct ebt_entries);
1728	return 0;
1729	}
1730
1731	if (*size < sizeof(*ce))
1732	return -EINVAL;
1733
1734	ce = *dstptr;
1735	if (copy_to_user(to: ce, from: e, n: sizeof(*ce)))
1736	return -EFAULT;
1737
1738	origsize = *size;
1739	*dstptr += sizeof(*ce);
1740
1741	ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
1742	if (ret)
1743	return ret;
1744	watchers_offset = e->watchers_offset - (origsize - *size);
1745
1746	ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
1747	if (ret)
1748	return ret;
1749	target_offset = e->target_offset - (origsize - *size);
1750
1751	t = ebt_get_target(e);
1752
1753	ret = compat_target_to_user(t, dstptr, size);
1754	if (ret)
1755	return ret;
1756	next_offset = e->next_offset - (origsize - *size);
1757
1758	if (put_user(watchers_offset, &ce->watchers_offset) ||
1759	put_user(target_offset, &ce->target_offset) ||
1760	put_user(next_offset, &ce->next_offset))
1761	return -EFAULT;
1762
1763	*size -= sizeof(*ce);
1764	return 0;
1765	}
1766
1767	static int compat_calc_match(struct ebt_entry_match *m, int *off)
1768	{
1769	*off += ebt_compat_match_offset(match: m->u.match, userlen: m->match_size);
1770	*off += ebt_compat_entry_padsize();
1771	return 0;
1772	}
1773
1774	static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
1775	{
1776	*off += xt_compat_target_offset(target: w->u.watcher);
1777	*off += ebt_compat_entry_padsize();
1778	return 0;
1779	}
1780
1781	static int compat_calc_entry(const struct ebt_entry *e,
1782	const struct ebt_table_info *info,
1783	const void *base,
1784	struct compat_ebt_replace *newinfo)
1785	{
1786	const struct ebt_entry_target *t;
1787	unsigned int entry_offset;
1788	int off, ret, i;
1789
1790	if (e->bitmask == 0)
1791	return 0;
1792
1793	off = 0;
1794	entry_offset = (void *)e - base;
1795
1796	EBT_MATCH_ITERATE(e, compat_calc_match, &off);
1797	EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
1798
1799	t = ebt_get_target_c(e);
1800
1801	off += xt_compat_target_offset(target: t->u.target);
1802	off += ebt_compat_entry_padsize();
1803
1804	newinfo->entries_size -= off;
1805
1806	ret = xt_compat_add_offset(af: NFPROTO_BRIDGE, offset: entry_offset, delta: off);
1807	if (ret)
1808	return ret;
1809
1810	for (i = 0; i < NF_BR_NUMHOOKS; i++) {
1811	const void *hookptr = info->hook_entry[i];
1812	if (info->hook_entry[i] &&
1813	(e < (struct ebt_entry *)(base - hookptr))) {
1814	newinfo->hook_entry[i] -= off;
1815	pr_debug("0x%08X -> 0x%08X\n",
1816	newinfo->hook_entry[i] + off,
1817	newinfo->hook_entry[i]);
1818	}
1819	}
1820
1821	return 0;
1822	}
1823
1824	static int ebt_compat_init_offsets(unsigned int number)
1825	{
1826	if (number > INT_MAX)
1827	return -EINVAL;
1828
1829	/* also count the base chain policies */
1830	number += NF_BR_NUMHOOKS;
1831
1832	return xt_compat_init_offsets(af: NFPROTO_BRIDGE, number);
1833	}
1834
1835	static int compat_table_info(const struct ebt_table_info *info,
1836	struct compat_ebt_replace *newinfo)
1837	{
1838	unsigned int size = info->entries_size;
1839	const void *entries = info->entries;
1840	int ret;
1841
1842	newinfo->entries_size = size;
1843	ret = ebt_compat_init_offsets(number: info->nentries);
1844	if (ret)
1845	return ret;
1846
1847	return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
1848	entries, newinfo);
1849	}
1850
1851	static int compat_copy_everything_to_user(struct ebt_table *t,
1852	void __user *user, int *len, int cmd)
1853	{
1854	struct compat_ebt_replace repl, tmp;
1855	struct ebt_counter *oldcounters;
1856	struct ebt_table_info tinfo;
1857	int ret;
1858	void __user *pos;
1859
1860	memset(&tinfo, 0, sizeof(tinfo));
1861
1862	if (cmd == EBT_SO_GET_ENTRIES) {
1863	tinfo.entries_size = t->private->entries_size;
1864	tinfo.nentries = t->private->nentries;
1865	tinfo.entries = t->private->entries;
1866	oldcounters = t->private->counters;
1867	} else {
1868	tinfo.entries_size = t->table->entries_size;
1869	tinfo.nentries = t->table->nentries;
1870	tinfo.entries = t->table->entries;
1871	oldcounters = t->table->counters;
1872	}
1873
1874	if (copy_from_user(to: &tmp, from: user, n: sizeof(tmp)))
1875	return -EFAULT;
1876
1877	if (tmp.nentries != tinfo.nentries ||
1878	(tmp.num_counters && tmp.num_counters != tinfo.nentries))
1879	return -EINVAL;
1880
1881	memcpy(&repl, &tmp, sizeof(repl));
1882	if (cmd == EBT_SO_GET_ENTRIES)
1883	ret = compat_table_info(info: t->private, newinfo: &repl);
1884	else
1885	ret = compat_table_info(info: &tinfo, newinfo: &repl);
1886	if (ret)
1887	return ret;
1888
1889	if (*len != sizeof(tmp) + repl.entries_size +
1890	(tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
1891	pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
1892	*len, tinfo.entries_size, repl.entries_size);
1893	return -EINVAL;
1894	}
1895
1896	/* userspace might not need the counters */
1897	ret = copy_counters_to_user(t, oldcounters, user: compat_ptr(uptr: tmp.counters),
1898	num_counters: tmp.num_counters, nentries: tinfo.nentries);
1899	if (ret)
1900	return ret;
1901
1902	pos = compat_ptr(uptr: tmp.entries);
1903	return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
1904	compat_copy_entry_to_user, &pos, &tmp.entries_size);
1905	}
1906
1907	struct ebt_entries_buf_state {
1908	char *buf_kern_start; /* kernel buffer to copy (translated) data to */
1909	u32 buf_kern_len; /* total size of kernel buffer */
1910	u32 buf_kern_offset; /* amount of data copied so far */
1911	u32 buf_user_offset; /* read position in userspace buffer */
1912	};
1913
1914	static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
1915	{
1916	state->buf_kern_offset += sz;
1917	return state->buf_kern_offset >= sz ? 0 : -EINVAL;
1918	}
1919
1920	static int ebt_buf_add(struct ebt_entries_buf_state *state,
1921	const void *data, unsigned int sz)
1922	{
1923	if (state->buf_kern_start == NULL)
1924	goto count_only;
1925
1926	if (WARN_ON(state->buf_kern_offset + sz > state->buf_kern_len))
1927	return -EINVAL;
1928
1929	memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz);
1930
1931	count_only:
1932	state->buf_user_offset += sz;
1933	return ebt_buf_count(state, sz);
1934	}
1935
1936	static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz)
1937	{
1938	char *b = state->buf_kern_start;
1939
1940	if (WARN_ON(b && state->buf_kern_offset > state->buf_kern_len))
1941	return -EINVAL;
1942
1943	if (b != NULL && sz > 0)
1944	memset(b + state->buf_kern_offset, 0, sz);
1945	/* do not adjust ->buf_user_offset here, we added kernel-side padding */
1946	return ebt_buf_count(state, sz);
1947	}
1948
1949	enum compat_mwt {
1950	EBT_COMPAT_MATCH,
1951	EBT_COMPAT_WATCHER,
1952	EBT_COMPAT_TARGET,
1953	};
1954
1955	static int compat_mtw_from_user(const struct compat_ebt_entry_mwt *mwt,
1956	enum compat_mwt compat_mwt,
1957	struct ebt_entries_buf_state *state,
1958	const unsigned char *base)
1959	{
1960	char name[EBT_EXTENSION_MAXNAMELEN];
1961	struct xt_match *match;
1962	struct xt_target *wt;
1963	void *dst = NULL;
1964	int off, pad = 0;
1965	unsigned int size_kern, match_size = mwt->match_size;
1966
1967	if (strscpy(name, mwt->u.name, sizeof(name)) < 0)
1968	return -EINVAL;
1969
1970	if (state->buf_kern_start)
1971	dst = state->buf_kern_start + state->buf_kern_offset;
1972
1973	switch (compat_mwt) {
1974	case EBT_COMPAT_MATCH:
1975	match = xt_request_find_match(af: NFPROTO_BRIDGE, name,
1976	revision: mwt->u.revision);
1977	if (IS_ERR(ptr: match))
1978	return PTR_ERR(ptr: match);
1979
1980	off = ebt_compat_match_offset(match, userlen: match_size);
1981	if (dst) {
1982	if (match->compat_from_user)
1983	match->compat_from_user(dst, mwt->data);
1984	else
1985	memcpy(dst, mwt->data, match_size);
1986	}
1987
1988	size_kern = match->matchsize;
1989	if (unlikely(size_kern == -1))
1990	size_kern = match_size;
1991	module_put(module: match->me);
1992	break;
1993	case EBT_COMPAT_WATCHER:
1994	case EBT_COMPAT_TARGET:
1995	wt = xt_request_find_target(af: NFPROTO_BRIDGE, name,
1996	revision: mwt->u.revision);
1997	if (IS_ERR(ptr: wt))
1998	return PTR_ERR(ptr: wt);
1999	off = xt_compat_target_offset(target: wt);
2000
2001	if (dst) {
2002	if (wt->compat_from_user)
2003	wt->compat_from_user(dst, mwt->data);
2004	else
2005	memcpy(dst, mwt->data, match_size);
2006	}
2007
2008	size_kern = wt->targetsize;
2009	module_put(module: wt->me);
2010	break;
2011
2012	default:
2013	return -EINVAL;
2014	}
2015
2016	state->buf_kern_offset += match_size + off;
2017	state->buf_user_offset += match_size;
2018	pad = XT_ALIGN(size_kern) - size_kern;
2019
2020	if (pad > 0 && dst) {
2021	if (WARN_ON(state->buf_kern_len <= pad))
2022	return -EINVAL;
2023	if (WARN_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad))
2024	return -EINVAL;
2025	memset(dst + size_kern, 0, pad);
2026	}
2027	return off + match_size;
2028	}
2029
2030	/* return size of all matches, watchers or target, including necessary
2031	* alignment and padding.
2032	*/
2033	static int ebt_size_mwt(const struct compat_ebt_entry_mwt *match32,
2034	unsigned int size_left, enum compat_mwt type,
2035	struct ebt_entries_buf_state *state, const void *base)
2036	{
2037	const char *buf = (const char *)match32;
2038	int growth = 0;
2039
2040	if (size_left == 0)
2041	return 0;
2042
2043	do {
2044	struct ebt_entry_match *match_kern;
2045	int ret;
2046
2047	if (size_left < sizeof(*match32))
2048	return -EINVAL;
2049
2050	match_kern = (struct ebt_entry_match *) state->buf_kern_start;
2051	if (match_kern) {
2052	char *tmp;
2053	tmp = state->buf_kern_start + state->buf_kern_offset;
2054	match_kern = (struct ebt_entry_match *) tmp;
2055	}
2056	ret = ebt_buf_add(state, data: buf, sz: sizeof(*match32));
2057	if (ret < 0)
2058	return ret;
2059	size_left -= sizeof(*match32);
2060
2061	/* add padding before match->data (if any) */
2062	ret = ebt_buf_add_pad(state, sz: ebt_compat_entry_padsize());
2063	if (ret < 0)
2064	return ret;
2065
2066	if (match32->match_size > size_left)
2067	return -EINVAL;
2068
2069	size_left -= match32->match_size;
2070
2071	ret = compat_mtw_from_user(mwt: match32, compat_mwt: type, state, base);
2072	if (ret < 0)
2073	return ret;
2074
2075	if (WARN_ON(ret < match32->match_size))
2076	return -EINVAL;
2077	growth += ret - match32->match_size;
2078	growth += ebt_compat_entry_padsize();
2079
2080	buf += sizeof(*match32);
2081	buf += match32->match_size;
2082
2083	if (match_kern)
2084	match_kern->match_size = ret;
2085
2086	match32 = (struct compat_ebt_entry_mwt *) buf;
2087	} while (size_left);
2088
2089	return growth;
2090	}
2091
2092	/* called for all ebt_entry structures. */
2093	static int size_entry_mwt(const struct ebt_entry *entry, const unsigned char *base,
2094	unsigned int *total,
2095	struct ebt_entries_buf_state *state)
2096	{
2097	unsigned int i, j, startoff, next_expected_off, new_offset = 0;
2098	/* stores match/watchers/targets & offset of next struct ebt_entry: */
2099	unsigned int offsets[4];
2100	unsigned int *offsets_update = NULL;
2101	int ret;
2102	char *buf_start;
2103
2104	if (*total < sizeof(struct ebt_entries))
2105	return -EINVAL;
2106
2107	if (!entry->bitmask) {
2108	*total -= sizeof(struct ebt_entries);
2109	return ebt_buf_add(state, data: entry, sz: sizeof(struct ebt_entries));
2110	}
2111	if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
2112	return -EINVAL;
2113
2114	startoff = state->buf_user_offset;
2115	/* pull in most part of ebt_entry, it does not need to be changed. */
2116	ret = ebt_buf_add(state, data: entry,
2117	offsetof(struct ebt_entry, watchers_offset));
2118	if (ret < 0)
2119	return ret;
2120
2121	offsets[0] = sizeof(struct ebt_entry); /* matches come first */
2122	memcpy(&offsets[1], &entry->offsets, sizeof(entry->offsets));
2123
2124	if (state->buf_kern_start) {
2125	buf_start = state->buf_kern_start + state->buf_kern_offset;
2126	offsets_update = (unsigned int *) buf_start;
2127	}
2128	ret = ebt_buf_add(state, data: &offsets[1],
2129	sz: sizeof(offsets) - sizeof(offsets[0]));
2130	if (ret < 0)
2131	return ret;
2132	buf_start = (char *) entry;
2133	/* 0: matches offset, always follows ebt_entry.
2134	* 1: watchers offset, from ebt_entry structure
2135	* 2: target offset, from ebt_entry structure
2136	* 3: next ebt_entry offset, from ebt_entry structure
2137	*
2138	* offsets are relative to beginning of struct ebt_entry (i.e., 0).
2139	*/
2140	for (i = 0; i < 4 ; ++i) {
2141	if (offsets[i] > *total)
2142	return -EINVAL;
2143
2144	if (i < 3 && offsets[i] == *total)
2145	return -EINVAL;
2146
2147	if (i == 0)
2148	continue;
2149	if (offsets[i-1] > offsets[i])
2150	return -EINVAL;
2151	}
2152
2153	for (i = 0, j = 1 ; j < 4 ; j++, i++) {
2154	struct compat_ebt_entry_mwt *match32;
2155	unsigned int size;
2156	char *buf = buf_start + offsets[i];
2157
2158	if (offsets[i] > offsets[j])
2159	return -EINVAL;
2160
2161	match32 = (struct compat_ebt_entry_mwt *) buf;
2162	size = offsets[j] - offsets[i];
2163	ret = ebt_size_mwt(match32, size_left: size, type: i, state, base);
2164	if (ret < 0)
2165	return ret;
2166	new_offset += ret;
2167	if (offsets_update && new_offset) {
2168	pr_debug("change offset %d to %d\n",
2169	offsets_update[i], offsets[j] + new_offset);
2170	offsets_update[i] = offsets[j] + new_offset;
2171	}
2172	}
2173
2174	if (state->buf_kern_start == NULL) {
2175	unsigned int offset = buf_start - (char *) base;
2176
2177	ret = xt_compat_add_offset(af: NFPROTO_BRIDGE, offset, delta: new_offset);
2178	if (ret < 0)
2179	return ret;
2180	}
2181
2182	next_expected_off = state->buf_user_offset - startoff;
2183	if (next_expected_off != entry->next_offset)
2184	return -EINVAL;
2185
2186	if (*total < entry->next_offset)
2187	return -EINVAL;
2188	*total -= entry->next_offset;
2189	return 0;
2190	}
2191
2192	/* repl->entries_size is the size of the ebt_entry blob in userspace.
2193	* It might need more memory when copied to a 64 bit kernel in case
2194	* userspace is 32-bit. So, first task: find out how much memory is needed.
2195	*
2196	* Called before validation is performed.
2197	*/
2198	static int compat_copy_entries(unsigned char *data, unsigned int size_user,
2199	struct ebt_entries_buf_state *state)
2200	{
2201	unsigned int size_remaining = size_user;
2202	int ret;
2203
2204	ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
2205	&size_remaining, state);
2206	if (ret < 0)
2207	return ret;
2208
2209	if (size_remaining)
2210	return -EINVAL;
2211
2212	return state->buf_kern_offset;
2213	}
2214
2215
2216	static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
2217	sockptr_t arg, unsigned int len)
2218	{
2219	struct compat_ebt_replace tmp;
2220	int i;
2221
2222	if (len < sizeof(tmp))
2223	return -EINVAL;
2224
2225	if (copy_from_sockptr(dst: &tmp, src: arg, size: sizeof(tmp)))
2226	return -EFAULT;
2227
2228	if (len != sizeof(tmp) + tmp.entries_size)
2229	return -EINVAL;
2230
2231	if (tmp.entries_size == 0)
2232	return -EINVAL;
2233
2234	if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
2235	NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
2236	return -ENOMEM;
2237	if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
2238	return -ENOMEM;
2239
2240	memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
2241
2242	/* starting with hook_entry, 32 vs. 64 bit structures are different */
2243	for (i = 0; i < NF_BR_NUMHOOKS; i++)
2244	repl->hook_entry[i] = compat_ptr(uptr: tmp.hook_entry[i]);
2245
2246	repl->num_counters = tmp.num_counters;
2247	repl->counters = compat_ptr(uptr: tmp.counters);
2248	repl->entries = compat_ptr(uptr: tmp.entries);
2249	return 0;
2250	}
2251
2252	static int compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
2253	{
2254	int ret, i, countersize, size64;
2255	struct ebt_table_info *newinfo;
2256	struct ebt_replace tmp;
2257	struct ebt_entries_buf_state state;
2258	void *entries_tmp;
2259
2260	ret = compat_copy_ebt_replace_from_user(repl: &tmp, arg, len);
2261	if (ret) {
2262	/* try real handler in case userland supplied needed padding */
2263	if (ret == -EINVAL && do_replace(net, arg, len) == 0)
2264	ret = 0;
2265	return ret;
2266	}
2267
2268	countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
2269	newinfo = vmalloc(size: sizeof(*newinfo) + countersize);
2270	if (!newinfo)
2271	return -ENOMEM;
2272
2273	if (countersize)
2274	memset(newinfo->counters, 0, countersize);
2275
2276	memset(&state, 0, sizeof(state));
2277
2278	newinfo->entries = vmalloc(size: tmp.entries_size);
2279	if (!newinfo->entries) {
2280	ret = -ENOMEM;
2281	goto free_newinfo;
2282	}
2283	if (copy_from_user(
2284	to: newinfo->entries, from: tmp.entries, n: tmp.entries_size) != 0) {
2285	ret = -EFAULT;
2286	goto free_entries;
2287	}
2288
2289	entries_tmp = newinfo->entries;
2290
2291	xt_compat_lock(af: NFPROTO_BRIDGE);
2292
2293	ret = ebt_compat_init_offsets(number: tmp.nentries);
2294	if (ret < 0)
2295	goto out_unlock;
2296
2297	ret = compat_copy_entries(data: entries_tmp, size_user: tmp.entries_size, state: &state);
2298	if (ret < 0)
2299	goto out_unlock;
2300
2301	pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
2302	tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
2303	xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
2304
2305	size64 = ret;
2306	newinfo->entries = vmalloc(size: size64);
2307	if (!newinfo->entries) {
2308	vfree(addr: entries_tmp);
2309	ret = -ENOMEM;
2310	goto out_unlock;
2311	}
2312
2313	memset(&state, 0, sizeof(state));
2314	state.buf_kern_start = newinfo->entries;
2315	state.buf_kern_len = size64;
2316
2317	ret = compat_copy_entries(data: entries_tmp, size_user: tmp.entries_size, state: &state);
2318	if (WARN_ON(ret < 0)) {
2319	vfree(addr: entries_tmp);
2320	goto out_unlock;
2321	}
2322
2323	vfree(addr: entries_tmp);
2324	tmp.entries_size = size64;
2325
2326	for (i = 0; i < NF_BR_NUMHOOKS; i++) {
2327	char __user *usrptr;
2328	if (tmp.hook_entry[i]) {
2329	unsigned int delta;
2330	usrptr = (char __user *) tmp.hook_entry[i];
2331	delta = usrptr - tmp.entries;
2332	usrptr += xt_compat_calc_jump(af: NFPROTO_BRIDGE, offset: delta);
2333	tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
2334	}
2335	}
2336
2337	xt_compat_flush_offsets(af: NFPROTO_BRIDGE);
2338	xt_compat_unlock(af: NFPROTO_BRIDGE);
2339
2340	ret = do_replace_finish(net, repl: &tmp, newinfo);
2341	if (ret == 0)
2342	return ret;
2343	free_entries:
2344	vfree(addr: newinfo->entries);
2345	free_newinfo:
2346	vfree(addr: newinfo);
2347	return ret;
2348	out_unlock:
2349	xt_compat_flush_offsets(af: NFPROTO_BRIDGE);
2350	xt_compat_unlock(af: NFPROTO_BRIDGE);
2351	goto free_entries;
2352	}
2353
2354	static int compat_update_counters(struct net *net, sockptr_t arg,
2355	unsigned int len)
2356	{
2357	struct compat_ebt_replace hlp;
2358
2359	if (len < sizeof(hlp))
2360	return -EINVAL;
2361	if (copy_from_sockptr(dst: &hlp, src: arg, size: sizeof(hlp)))
2362	return -EFAULT;
2363
2364	/* try real handler in case userland supplied needed padding */
2365	if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
2366	return update_counters(net, arg, len);
2367
2368	return do_update_counters(net, name: hlp.name, counters: compat_ptr(uptr: hlp.counters),
2369	num_counters: hlp.num_counters, len);
2370	}
2371
2372	static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
2373	void __user *user, int *len)
2374	{
2375	int ret;
2376	struct compat_ebt_replace tmp;
2377	struct ebt_table *t;
2378	struct net *net = sock_net(sk);
2379
2380	if ((cmd == EBT_SO_GET_INFO || cmd == EBT_SO_GET_INIT_INFO) &&
2381	*len != sizeof(struct compat_ebt_replace))
2382	return -EINVAL;
2383
2384	if (copy_from_user(to: &tmp, from: user, n: sizeof(tmp)))
2385	return -EFAULT;
2386
2387	tmp.name[sizeof(tmp.name) - 1] = '\0';
2388
2389	t = find_table_lock(net, name: tmp.name, error: &ret, mutex: &ebt_mutex);
2390	if (!t)
2391	return ret;
2392
2393	xt_compat_lock(af: NFPROTO_BRIDGE);
2394	switch (cmd) {
2395	case EBT_SO_GET_INFO:
2396	tmp.nentries = t->private->nentries;
2397	ret = compat_table_info(info: t->private, newinfo: &tmp);
2398	if (ret)
2399	goto out;
2400	tmp.valid_hooks = t->valid_hooks;
2401
2402	if (copy_to_user(to: user, from: &tmp, n: *len) != 0) {
2403	ret = -EFAULT;
2404	break;
2405	}
2406	ret = 0;
2407	break;
2408	case EBT_SO_GET_INIT_INFO:
2409	tmp.nentries = t->table->nentries;
2410	tmp.entries_size = t->table->entries_size;
2411	tmp.valid_hooks = t->table->valid_hooks;
2412
2413	if (copy_to_user(to: user, from: &tmp, n: *len) != 0) {
2414	ret = -EFAULT;
2415	break;
2416	}
2417	ret = 0;
2418	break;
2419	case EBT_SO_GET_ENTRIES:
2420	case EBT_SO_GET_INIT_ENTRIES:
2421	/* try real handler first in case of userland-side padding.
2422	* in case we are dealing with an 'ordinary' 32 bit binary
2423	* without 64bit compatibility padding, this will fail right
2424	* after copy_from_user when the *len argument is validated.
2425	*
2426	* the compat_ variant needs to do one pass over the kernel
2427	* data set to adjust for size differences before it the check.
2428	*/
2429	if (copy_everything_to_user(t, user, len, cmd) == 0)
2430	ret = 0;
2431	else
2432	ret = compat_copy_everything_to_user(t, user, len, cmd);
2433	break;
2434	default:
2435	ret = -EINVAL;
2436	}
2437	out:
2438	xt_compat_flush_offsets(af: NFPROTO_BRIDGE);
2439	xt_compat_unlock(af: NFPROTO_BRIDGE);
2440	mutex_unlock(lock: &ebt_mutex);
2441	return ret;
2442	}
2443	#endif
2444
2445	static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
2446	{
2447	struct net *net = sock_net(sk);
2448	struct ebt_replace tmp;
2449	struct ebt_table *t;
2450	int ret;
2451
2452	if (!ns_capable(ns: net->user_ns, CAP_NET_ADMIN))
2453	return -EPERM;
2454
2455	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
2456	/* try real handler in case userland supplied needed padding */
2457	if (in_compat_syscall() &&
2458	((cmd != EBT_SO_GET_INFO && cmd != EBT_SO_GET_INIT_INFO) ||
2459	*len != sizeof(tmp)))
2460	return compat_do_ebt_get_ctl(sk, cmd, user, len);
2461	#endif
2462
2463	if (copy_from_user(to: &tmp, from: user, n: sizeof(tmp)))
2464	return -EFAULT;
2465
2466	tmp.name[sizeof(tmp.name) - 1] = '\0';
2467
2468	t = find_table_lock(net, name: tmp.name, error: &ret, mutex: &ebt_mutex);
2469	if (!t)
2470	return ret;
2471
2472	switch (cmd) {
2473	case EBT_SO_GET_INFO:
2474	case EBT_SO_GET_INIT_INFO:
2475	if (*len != sizeof(struct ebt_replace)) {
2476	ret = -EINVAL;
2477	mutex_unlock(lock: &ebt_mutex);
2478	break;
2479	}
2480	if (cmd == EBT_SO_GET_INFO) {
2481	tmp.nentries = t->private->nentries;
2482	tmp.entries_size = t->private->entries_size;
2483	tmp.valid_hooks = t->valid_hooks;
2484	} else {
2485	tmp.nentries = t->table->nentries;
2486	tmp.entries_size = t->table->entries_size;
2487	tmp.valid_hooks = t->table->valid_hooks;
2488	}
2489	mutex_unlock(lock: &ebt_mutex);
2490	if (copy_to_user(to: user, from: &tmp, n: *len) != 0) {
2491	ret = -EFAULT;
2492	break;
2493	}
2494	ret = 0;
2495	break;
2496
2497	case EBT_SO_GET_ENTRIES:
2498	case EBT_SO_GET_INIT_ENTRIES:
2499	ret = copy_everything_to_user(t, user, len, cmd);
2500	mutex_unlock(lock: &ebt_mutex);
2501	break;
2502
2503	default:
2504	mutex_unlock(lock: &ebt_mutex);
2505	ret = -EINVAL;
2506	}
2507
2508	return ret;
2509	}
2510
2511	static int do_ebt_set_ctl(struct sock *sk, int cmd, sockptr_t arg,
2512	unsigned int len)
2513	{
2514	struct net *net = sock_net(sk);
2515	int ret;
2516
2517	if (!ns_capable(ns: net->user_ns, CAP_NET_ADMIN))
2518	return -EPERM;
2519
2520	switch (cmd) {
2521	case EBT_SO_SET_ENTRIES:
2522	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
2523	if (in_compat_syscall())
2524	ret = compat_do_replace(net, arg, len);
2525	else
2526	#endif
2527	ret = do_replace(net, arg, len);
2528	break;
2529	case EBT_SO_SET_COUNTERS:
2530	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
2531	if (in_compat_syscall())
2532	ret = compat_update_counters(net, arg, len);
2533	else
2534	#endif
2535	ret = update_counters(net, arg, len);
2536	break;
2537	default:
2538	ret = -EINVAL;
2539	}
2540	return ret;
2541	}
2542
2543	static struct nf_sockopt_ops ebt_sockopts = {
2544	.pf = PF_INET,
2545	.set_optmin = EBT_BASE_CTL,
2546	.set_optmax = EBT_SO_SET_MAX + 1,
2547	.set = do_ebt_set_ctl,
2548	.get_optmin = EBT_BASE_CTL,
2549	.get_optmax = EBT_SO_GET_MAX + 1,
2550	.get = do_ebt_get_ctl,
2551	.owner = THIS_MODULE,
2552	};
2553
2554	static int __net_init ebt_pernet_init(struct net *net)
2555	{
2556	struct ebt_pernet *ebt_net = net_generic(net, id: ebt_pernet_id);
2557
2558	INIT_LIST_HEAD(list: &ebt_net->tables);
2559	return 0;
2560	}
2561
2562	static struct pernet_operations ebt_net_ops = {
2563	.init = ebt_pernet_init,
2564	.id = &ebt_pernet_id,
2565	.size = sizeof(struct ebt_pernet),
2566	};
2567
2568	static int __init ebtables_init(void)
2569	{
2570	int ret;
2571
2572	ret = xt_register_target(target: &ebt_standard_target);
2573	if (ret < 0)
2574	return ret;
2575	ret = nf_register_sockopt(reg: &ebt_sockopts);
2576	if (ret < 0) {
2577	xt_unregister_target(target: &ebt_standard_target);
2578	return ret;
2579	}
2580
2581	ret = register_pernet_subsys(&ebt_net_ops);
2582	if (ret < 0) {
2583	nf_unregister_sockopt(reg: &ebt_sockopts);
2584	xt_unregister_target(target: &ebt_standard_target);
2585	return ret;
2586	}
2587
2588	return 0;
2589	}
2590
2591	static void ebtables_fini(void)
2592	{
2593	nf_unregister_sockopt(reg: &ebt_sockopts);
2594	xt_unregister_target(target: &ebt_standard_target);
2595	unregister_pernet_subsys(&ebt_net_ops);
2596	}
2597
2598	EXPORT_SYMBOL(ebt_register_table);
2599	EXPORT_SYMBOL(ebt_unregister_table);
2600	EXPORT_SYMBOL(ebt_do_table);
2601	module_init(ebtables_init);
2602	module_exit(ebtables_fini);
2603	MODULE_LICENSE("GPL");
2604	MODULE_DESCRIPTION("ebtables legacy core");
2605