1	// SPDX-License-Identifier: GPL-2.0-only
2	/*
3	* Packet matching code.
4	*
5	* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
6	* Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
7	* Copyright (c) 2006-2010 Patrick McHardy <kaber@trash.net>
8	*/
9
10	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12	#include <linux/kernel.h>
13	#include <linux/capability.h>
14	#include <linux/in.h>
15	#include <linux/skbuff.h>
16	#include <linux/kmod.h>
17	#include <linux/vmalloc.h>
18	#include <linux/netdevice.h>
19	#include <linux/module.h>
20	#include <linux/poison.h>
21	#include <net/ipv6.h>
22	#include <net/compat.h>
23	#include <linux/uaccess.h>
24	#include <linux/mutex.h>
25	#include <linux/proc_fs.h>
26	#include <linux/err.h>
27	#include <linux/cpumask.h>
28
29	#include <linux/netfilter_ipv6/ip6_tables.h>
30	#include <linux/netfilter/x_tables.h>
31	#include <net/netfilter/nf_log.h>
32	#include "../../netfilter/xt_repldata.h"
33
34	MODULE_LICENSE("GPL");
35	MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
36	MODULE_DESCRIPTION("IPv6 packet filter");
37
38	void *ip6t_alloc_initial_table(const struct xt_table *info)
39	{
40	return xt_alloc_initial_table(ip6t, IP6T);
41	}
42	EXPORT_SYMBOL_GPL(ip6t_alloc_initial_table);
43
44	/* Returns whether matches rule or not. */
45	/* Performance critical - called for every packet */
46	static inline bool
47	ip6_packet_match(const struct sk_buff *skb,
48	const char *indev,
49	const char *outdev,
50	const struct ip6t_ip6 *ip6info,
51	unsigned int *protoff,
52	u16 *fragoff, bool *hotdrop)
53	{
54	unsigned long ret;
55	const struct ipv6hdr *ipv6 = ipv6_hdr(skb);
56
57	if (NF_INVF(ip6info, IP6T_INV_SRCIP,
58	ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk,
59	&ip6info->src)) ||
60	NF_INVF(ip6info, IP6T_INV_DSTIP,
61	ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk,
62	&ip6info->dst)))
63	return false;
64
65	ret = ifname_compare_aligned(a: indev, b: ip6info->iniface, mask: ip6info->iniface_mask);
66
67	if (NF_INVF(ip6info, IP6T_INV_VIA_IN, ret != 0))
68	return false;
69
70	ret = ifname_compare_aligned(a: outdev, b: ip6info->outiface, mask: ip6info->outiface_mask);
71
72	if (NF_INVF(ip6info, IP6T_INV_VIA_OUT, ret != 0))
73	return false;
74
75	/* ... might want to do something with class and flowlabel here ... */
76
77	/* look for the desired protocol header */
78	if (ip6info->flags & IP6T_F_PROTO) {
79	int protohdr;
80	unsigned short _frag_off;
81
82	protohdr = ipv6_find_hdr(skb, offset: protoff, target: -1, fragoff: &_frag_off, NULL);
83	if (protohdr < 0) {
84	if (_frag_off == 0)
85	*hotdrop = true;
86	return false;
87	}
88	*fragoff = _frag_off;
89
90	if (ip6info->proto == protohdr) {
91	if (ip6info->invflags & IP6T_INV_PROTO)
92	return false;
93
94	return true;
95	}
96
97	/* We need match for the '-p all', too! */
98	if ((ip6info->proto != 0) &&
99	!(ip6info->invflags & IP6T_INV_PROTO))
100	return false;
101	}
102	return true;
103	}
104
105	/* should be ip6 safe */
106	static bool
107	ip6_checkentry(const struct ip6t_ip6 *ipv6)
108	{
109	if (ipv6->flags & ~IP6T_F_MASK)
110	return false;
111	if (ipv6->invflags & ~IP6T_INV_MASK)
112	return false;
113
114	return true;
115	}
116
117	static unsigned int
118	ip6t_error(struct sk_buff *skb, const struct xt_action_param *par)
119	{
120	net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo);
121
122	return NF_DROP;
123	}
124
125	static inline struct ip6t_entry *
126	get_entry(const void *base, unsigned int offset)
127	{
128	return (struct ip6t_entry *)(base + offset);
129	}
130
131	/* All zeroes == unconditional rule. */
132	/* Mildly perf critical (only if packet tracing is on) */
133	static inline bool unconditional(const struct ip6t_entry *e)
134	{
135	static const struct ip6t_ip6 uncond;
136
137	return e->target_offset == sizeof(struct ip6t_entry) &&
138	memcmp(p: &e->ipv6, q: &uncond, size: sizeof(uncond)) == 0;
139	}
140
141	static inline const struct xt_entry_target *
142	ip6t_get_target_c(const struct ip6t_entry *e)
143	{
144	return ip6t_get_target(e: (struct ip6t_entry *)e);
145	}
146
147	#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
148	/* This cries for unification! */
149	static const char *const hooknames[] = {
150	[NF_INET_PRE_ROUTING] = "PREROUTING",
151	[NF_INET_LOCAL_IN] = "INPUT",
152	[NF_INET_FORWARD] = "FORWARD",
153	[NF_INET_LOCAL_OUT] = "OUTPUT",
154	[NF_INET_POST_ROUTING] = "POSTROUTING",
155	};
156
157	enum nf_ip_trace_comments {
158	NF_IP6_TRACE_COMMENT_RULE,
159	NF_IP6_TRACE_COMMENT_RETURN,
160	NF_IP6_TRACE_COMMENT_POLICY,
161	};
162
163	static const char *const comments[] = {
164	[NF_IP6_TRACE_COMMENT_RULE] = "rule",
165	[NF_IP6_TRACE_COMMENT_RETURN] = "return",
166	[NF_IP6_TRACE_COMMENT_POLICY] = "policy",
167	};
168
169	static const struct nf_loginfo trace_loginfo = {
170	.type = NF_LOG_TYPE_LOG,
171	.u = {
172	.log = {
173	.level = LOGLEVEL_WARNING,
174	.logflags = NF_LOG_DEFAULT_MASK,
175	},
176	},
177	};
178
179	/* Mildly perf critical (only if packet tracing is on) */
180	static inline int
181	get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e,
182	const char *hookname, const char **chainname,
183	const char **comment, unsigned int *rulenum)
184	{
185	const struct xt_standard_target *t = (void *)ip6t_get_target_c(e: s);
186
187	if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) {
188	/* Head of user chain: ERROR target with chainname */
189	*chainname = t->target.data;
190	(*rulenum) = 0;
191	} else if (s == e) {
192	(*rulenum)++;
193
194	if (unconditional(e: s) &&
195	strcmp(t->target.u.kernel.target->name,
196	XT_STANDARD_TARGET) == 0 &&
197	t->verdict < 0) {
198	/* Tail of chains: STANDARD target (return/policy) */
199	*comment = *chainname == hookname
200	? comments[NF_IP6_TRACE_COMMENT_POLICY]
201	: comments[NF_IP6_TRACE_COMMENT_RETURN];
202	}
203	return 1;
204	} else
205	(*rulenum)++;
206
207	return 0;
208	}
209
210	static void trace_packet(struct net *net,
211	const struct sk_buff *skb,
212	unsigned int hook,
213	const struct net_device *in,
214	const struct net_device *out,
215	const char *tablename,
216	const struct xt_table_info *private,
217	const struct ip6t_entry *e)
218	{
219	const struct ip6t_entry *root;
220	const char *hookname, *chainname, *comment;
221	const struct ip6t_entry *iter;
222	unsigned int rulenum = 0;
223
224	root = get_entry(base: private->entries, offset: private->hook_entry[hook]);
225
226	hookname = chainname = hooknames[hook];
227	comment = comments[NF_IP6_TRACE_COMMENT_RULE];
228
229	xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
230	if (get_chainname_rulenum(s: iter, e, hookname,
231	chainname: &chainname, comment: &comment, rulenum: &rulenum) != 0)
232	break;
233
234	nf_log_trace(net, AF_INET6, hooknum: hook, skb, in, out, li: &trace_loginfo,
235	fmt: "TRACE: %s:%s:%s:%u ",
236	tablename, chainname, comment, rulenum);
237	}
238	#endif
239
240	static inline struct ip6t_entry *
241	ip6t_next_entry(const struct ip6t_entry *entry)
242	{
243	return (void *)entry + entry->next_offset;
244	}
245
246	/* Returns one of the generic firewall policies, like NF_ACCEPT. */
247	unsigned int
248	ip6t_do_table(void *priv, struct sk_buff *skb,
249	const struct nf_hook_state *state)
250	{
251	const struct xt_table *table = priv;
252	unsigned int hook = state->hook;
253	static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
254	/* Initializing verdict to NF_DROP keeps gcc happy. */
255	unsigned int verdict = NF_DROP;
256	const char *indev, *outdev;
257	const void *table_base;
258	struct ip6t_entry *e, **jumpstack;
259	unsigned int stackidx, cpu;
260	const struct xt_table_info *private;
261	struct xt_action_param acpar;
262	unsigned int addend;
263
264	/* Initialization */
265	stackidx = 0;
266	indev = state->in ? state->in->name : nulldevname;
267	outdev = state->out ? state->out->name : nulldevname;
268	/* We handle fragments by dealing with the first fragment as
269	* if it was a normal packet. All other fragments are treated
270	* normally, except that they will NEVER match rules that ask
271	* things we don't know, ie. tcp syn flag or ports). If the
272	* rule is also a fragment-specific rule, non-fragments won't
273	* match it. */
274	acpar.fragoff = 0;
275	acpar.hotdrop = false;
276	acpar.state = state;
277
278	WARN_ON(!(table->valid_hooks & (1 << hook)));
279
280	local_bh_disable();
281	addend = xt_write_recseq_begin();
282	private = READ_ONCE(table->private); /* Address dependency. */
283	cpu = smp_processor_id();
284	table_base = private->entries;
285	jumpstack = (struct ip6t_entry **)private->jumpstack[cpu];
286
287	/* Switch to alternate jumpstack if we're being invoked via TEE.
288	* TEE issues XT_CONTINUE verdict on original skb so we must not
289	* clobber the jumpstack.
290	*
291	* For recursion via REJECT or SYNPROXY the stack will be clobbered
292	* but it is no problem since absolute verdict is issued by these.
293	*/
294	if (static_key_false(key: &xt_tee_enabled))
295	jumpstack += private->stacksize * current->in_nf_duplicate;
296
297	e = get_entry(base: table_base, offset: private->hook_entry[hook]);
298
299	do {
300	const struct xt_entry_target *t;
301	const struct xt_entry_match *ematch;
302	struct xt_counters *counter;
303
304	WARN_ON(!e);
305	acpar.thoff = 0;
306	if (!ip6_packet_match(skb, indev, outdev, ip6info: &e->ipv6,
307	protoff: &acpar.thoff, fragoff: &acpar.fragoff, hotdrop: &acpar.hotdrop)) {
308	no_match:
309	e = ip6t_next_entry(entry: e);
310	continue;
311	}
312
313	xt_ematch_foreach(ematch, e) {
314	acpar.match = ematch->u.kernel.match;
315	acpar.matchinfo = ematch->data;
316	if (!acpar.match->match(skb, &acpar))
317	goto no_match;
318	}
319
320	counter = xt_get_this_cpu_counter(cnt: &e->counters);
321	ADD_COUNTER(*counter, skb->len, 1);
322
323	t = ip6t_get_target_c(e);
324	WARN_ON(!t->u.kernel.target);
325
326	#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
327	/* The packet is traced: log it */
328	if (unlikely(skb->nf_trace))
329	trace_packet(net: state->net, skb, hook, in: state->in,
330	out: state->out, tablename: table->name, private, e);
331	#endif
332	/* Standard target? */
333	if (!t->u.kernel.target->target) {
334	int v;
335
336	v = ((struct xt_standard_target *)t)->verdict;
337	if (v < 0) {
338	/* Pop from stack? */
339	if (v != XT_RETURN) {
340	verdict = (unsigned int)(-v) - 1;
341	break;
342	}
343	if (stackidx == 0)
344	e = get_entry(base: table_base,
345	offset: private->underflow[hook]);
346	else
347	e = ip6t_next_entry(entry: jumpstack[--stackidx]);
348	continue;
349	}
350	if (table_base + v != ip6t_next_entry(entry: e) &&
351	!(e->ipv6.flags & IP6T_F_GOTO)) {
352	if (unlikely(stackidx >= private->stacksize)) {
353	verdict = NF_DROP;
354	break;
355	}
356	jumpstack[stackidx++] = e;
357	}
358
359	e = get_entry(base: table_base, offset: v);
360	continue;
361	}
362
363	acpar.target = t->u.kernel.target;
364	acpar.targinfo = t->data;
365
366	verdict = t->u.kernel.target->target(skb, &acpar);
367	if (verdict == XT_CONTINUE)
368	e = ip6t_next_entry(entry: e);
369	else
370	/* Verdict */
371	break;
372	} while (!acpar.hotdrop);
373
374	xt_write_recseq_end(addend);
375	local_bh_enable();
376
377	if (acpar.hotdrop)
378	return NF_DROP;
379	else return verdict;
380	}
381
382	/* Figures out from what hook each rule can be called: returns 0 if
383	there are loops. Puts hook bitmask in comefrom. */
384	static int
385	mark_source_chains(const struct xt_table_info *newinfo,
386	unsigned int valid_hooks, void *entry0,
387	unsigned int *offsets)
388	{
389	unsigned int hook;
390
391	/* No recursion; use packet counter to save back ptrs (reset
392	to 0 as we leave), and comefrom to save source hook bitmask */
393	for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
394	unsigned int pos = newinfo->hook_entry[hook];
395	struct ip6t_entry *e = entry0 + pos;
396
397	if (!(valid_hooks & (1 << hook)))
398	continue;
399
400	/* Set initial back pointer. */
401	e->counters.pcnt = pos;
402
403	for (;;) {
404	const struct xt_standard_target *t
405	= (void *)ip6t_get_target_c(e);
406	int visited = e->comefrom & (1 << hook);
407
408	if (e->comefrom & (1 << NF_INET_NUMHOOKS))
409	return 0;
410
411	e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
412
413	/* Unconditional return/END. */
414	if ((unconditional(e) &&
415	(strcmp(t->target.u.user.name,
416	XT_STANDARD_TARGET) == 0) &&
417	t->verdict < 0) || visited) {
418	unsigned int oldpos, size;
419
420	/* Return: backtrack through the last
421	big jump. */
422	do {
423	e->comefrom ^= (1<<NF_INET_NUMHOOKS);
424	oldpos = pos;
425	pos = e->counters.pcnt;
426	e->counters.pcnt = 0;
427
428	/* We're at the start. */
429	if (pos == oldpos)
430	goto next;
431
432	e = entry0 + pos;
433	} while (oldpos == pos + e->next_offset);
434
435	/* Move along one */
436	size = e->next_offset;
437	e = entry0 + pos + size;
438	if (pos + size >= newinfo->size)
439	return 0;
440	e->counters.pcnt = pos;
441	pos += size;
442	} else {
443	int newpos = t->verdict;
444
445	if (strcmp(t->target.u.user.name,
446	XT_STANDARD_TARGET) == 0 &&
447	newpos >= 0) {
448	/* This a jump; chase it. */
449	if (!xt_find_jump_offset(offsets, target: newpos,
450	size: newinfo->number))
451	return 0;
452	} else {
453	/* ... this is a fallthru */
454	newpos = pos + e->next_offset;
455	if (newpos >= newinfo->size)
456	return 0;
457	}
458	e = entry0 + newpos;
459	e->counters.pcnt = pos;
460	pos = newpos;
461	}
462	}
463	next: ;
464	}
465	return 1;
466	}
467
468	static void cleanup_match(struct xt_entry_match *m, struct net *net)
469	{
470	struct xt_mtdtor_param par;
471
472	par.net = net;
473	par.match = m->u.kernel.match;
474	par.matchinfo = m->data;
475	par.family = NFPROTO_IPV6;
476	if (par.match->destroy != NULL)
477	par.match->destroy(&par);
478	module_put(module: par.match->me);
479	}
480
481	static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
482	{
483	const struct ip6t_ip6 *ipv6 = par->entryinfo;
484
485	par->match = m->u.kernel.match;
486	par->matchinfo = m->data;
487
488	return xt_check_match(par, size: m->u.match_size - sizeof(*m),
489	proto: ipv6->proto, inv_proto: ipv6->invflags & IP6T_INV_PROTO);
490	}
491
492	static int
493	find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
494	{
495	struct xt_match *match;
496	int ret;
497
498	match = xt_request_find_match(af: NFPROTO_IPV6, name: m->u.user.name,
499	revision: m->u.user.revision);
500	if (IS_ERR(ptr: match))
501	return PTR_ERR(ptr: match);
502
503	m->u.kernel.match = match;
504
505	ret = check_match(m, par);
506	if (ret)
507	goto err;
508
509	return 0;
510	err:
511	module_put(module: m->u.kernel.match->me);
512	return ret;
513	}
514
515	static int check_target(struct ip6t_entry *e, struct net *net, const char *name)
516	{
517	struct xt_entry_target *t = ip6t_get_target(e);
518	struct xt_tgchk_param par = {
519	.net = net,
520	.table = name,
521	.entryinfo = e,
522	.target = t->u.kernel.target,
523	.targinfo = t->data,
524	.hook_mask = e->comefrom,
525	.family = NFPROTO_IPV6,
526	};
527
528	return xt_check_target(&par, size: t->u.target_size - sizeof(*t),
529	proto: e->ipv6.proto,
530	inv_proto: e->ipv6.invflags & IP6T_INV_PROTO);
531	}
532
533	static int
534	find_check_entry(struct ip6t_entry *e, struct net *net, const char *name,
535	unsigned int size,
536	struct xt_percpu_counter_alloc_state *alloc_state)
537	{
538	struct xt_entry_target *t;
539	struct xt_target *target;
540	int ret;
541	unsigned int j;
542	struct xt_mtchk_param mtpar;
543	struct xt_entry_match *ematch;
544
545	if (!xt_percpu_counter_alloc(state: alloc_state, counter: &e->counters))
546	return -ENOMEM;
547
548	j = 0;
549	memset(&mtpar, 0, sizeof(mtpar));
550	mtpar.net = net;
551	mtpar.table = name;
552	mtpar.entryinfo = &e->ipv6;
553	mtpar.hook_mask = e->comefrom;
554	mtpar.family = NFPROTO_IPV6;
555	xt_ematch_foreach(ematch, e) {
556	ret = find_check_match(m: ematch, par: &mtpar);
557	if (ret != 0)
558	goto cleanup_matches;
559	++j;
560	}
561
562	t = ip6t_get_target(e);
563	target = xt_request_find_target(af: NFPROTO_IPV6, name: t->u.user.name,
564	revision: t->u.user.revision);
565	if (IS_ERR(ptr: target)) {
566	ret = PTR_ERR(ptr: target);
567	goto cleanup_matches;
568	}
569	t->u.kernel.target = target;
570
571	ret = check_target(e, net, name);
572	if (ret)
573	goto err;
574	return 0;
575	err:
576	module_put(module: t->u.kernel.target->me);
577	cleanup_matches:
578	xt_ematch_foreach(ematch, e) {
579	if (j-- == 0)
580	break;
581	cleanup_match(m: ematch, net);
582	}
583
584	xt_percpu_counter_free(cnt: &e->counters);
585
586	return ret;
587	}
588
589	static bool check_underflow(const struct ip6t_entry *e)
590	{
591	const struct xt_entry_target *t;
592	unsigned int verdict;
593
594	if (!unconditional(e))
595	return false;
596	t = ip6t_get_target_c(e);
597	if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
598	return false;
599	verdict = ((struct xt_standard_target *)t)->verdict;
600	verdict = -verdict - 1;
601	return verdict == NF_DROP || verdict == NF_ACCEPT;
602	}
603
604	static int
605	check_entry_size_and_hooks(struct ip6t_entry *e,
606	struct xt_table_info *newinfo,
607	const unsigned char *base,
608	const unsigned char *limit,
609	const unsigned int *hook_entries,
610	const unsigned int *underflows,
611	unsigned int valid_hooks)
612	{
613	unsigned int h;
614	int err;
615
616	if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 ||
617	(unsigned char *)e + sizeof(struct ip6t_entry) >= limit ||
618	(unsigned char *)e + e->next_offset > limit)
619	return -EINVAL;
620
621	if (e->next_offset
622	< sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target))
623	return -EINVAL;
624
625	if (!ip6_checkentry(ipv6: &e->ipv6))
626	return -EINVAL;
627
628	err = xt_check_entry_offsets(base: e, elems: e->elems, target_offset: e->target_offset,
629	next_offset: e->next_offset);
630	if (err)
631	return err;
632
633	/* Check hooks & underflows */
634	for (h = 0; h < NF_INET_NUMHOOKS; h++) {
635	if (!(valid_hooks & (1 << h)))
636	continue;
637	if ((unsigned char *)e - base == hook_entries[h])
638	newinfo->hook_entry[h] = hook_entries[h];
639	if ((unsigned char *)e - base == underflows[h]) {
640	if (!check_underflow(e))
641	return -EINVAL;
642
643	newinfo->underflow[h] = underflows[h];
644	}
645	}
646
647	/* Clear counters and comefrom */
648	e->counters = ((struct xt_counters) { 0, 0 });
649	e->comefrom = 0;
650	return 0;
651	}
652
653	static void cleanup_entry(struct ip6t_entry *e, struct net *net)
654	{
655	struct xt_tgdtor_param par;
656	struct xt_entry_target *t;
657	struct xt_entry_match *ematch;
658
659	/* Cleanup all matches */
660	xt_ematch_foreach(ematch, e)
661	cleanup_match(m: ematch, net);
662	t = ip6t_get_target(e);
663
664	par.net = net;
665	par.target = t->u.kernel.target;
666	par.targinfo = t->data;
667	par.family = NFPROTO_IPV6;
668	if (par.target->destroy != NULL)
669	par.target->destroy(&par);
670	module_put(module: par.target->me);
671	xt_percpu_counter_free(cnt: &e->counters);
672	}
673
674	/* Checks and translates the user-supplied table segment (held in
675	newinfo) */
676	static int
677	translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
678	const struct ip6t_replace *repl)
679	{
680	struct xt_percpu_counter_alloc_state alloc_state = { 0 };
681	struct ip6t_entry *iter;
682	unsigned int *offsets;
683	unsigned int i;
684	int ret = 0;
685
686	newinfo->size = repl->size;
687	newinfo->number = repl->num_entries;
688
689	/* Init all hooks to impossible value. */
690	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
691	newinfo->hook_entry[i] = 0xFFFFFFFF;
692	newinfo->underflow[i] = 0xFFFFFFFF;
693	}
694
695	offsets = xt_alloc_entry_offsets(size: newinfo->number);
696	if (!offsets)
697	return -ENOMEM;
698	i = 0;
699	/* Walk through entries, checking offsets. */
700	xt_entry_foreach(iter, entry0, newinfo->size) {
701	ret = check_entry_size_and_hooks(e: iter, newinfo, base: entry0,
702	limit: entry0 + repl->size,
703	hook_entries: repl->hook_entry,
704	underflows: repl->underflow,
705	valid_hooks: repl->valid_hooks);
706	if (ret != 0)
707	goto out_free;
708	if (i < repl->num_entries)
709	offsets[i] = (void *)iter - entry0;
710	++i;
711	if (strcmp(ip6t_get_target(e: iter)->u.user.name,
712	XT_ERROR_TARGET) == 0)
713	++newinfo->stacksize;
714	}
715
716	ret = -EINVAL;
717	if (i != repl->num_entries)
718	goto out_free;
719
720	ret = xt_check_table_hooks(info: newinfo, valid_hooks: repl->valid_hooks);
721	if (ret)
722	goto out_free;
723
724	if (!mark_source_chains(newinfo, valid_hooks: repl->valid_hooks, entry0, offsets)) {
725	ret = -ELOOP;
726	goto out_free;
727	}
728	kvfree(addr: offsets);
729
730	/* Finally, each sanity check must pass */
731	i = 0;
732	xt_entry_foreach(iter, entry0, newinfo->size) {
733	ret = find_check_entry(e: iter, net, name: repl->name, size: repl->size,
734	alloc_state: &alloc_state);
735	if (ret != 0)
736	break;
737	++i;
738	}
739
740	if (ret != 0) {
741	xt_entry_foreach(iter, entry0, newinfo->size) {
742	if (i-- == 0)
743	break;
744	cleanup_entry(e: iter, net);
745	}
746	return ret;
747	}
748
749	return ret;
750	out_free:
751	kvfree(addr: offsets);
752	return ret;
753	}
754
755	static void
756	get_counters(const struct xt_table_info *t,
757	struct xt_counters counters[])
758	{
759	struct ip6t_entry *iter;
760	unsigned int cpu;
761	unsigned int i;
762
763	for_each_possible_cpu(cpu) {
764	seqcount_t *s = &per_cpu(xt_recseq, cpu);
765
766	i = 0;
767	xt_entry_foreach(iter, t->entries, t->size) {
768	struct xt_counters *tmp;
769	u64 bcnt, pcnt;
770	unsigned int start;
771
772	tmp = xt_get_per_cpu_counter(cnt: &iter->counters, cpu);
773	do {
774	start = read_seqcount_begin(s);
775	bcnt = tmp->bcnt;
776	pcnt = tmp->pcnt;
777	} while (read_seqcount_retry(s, start));
778
779	ADD_COUNTER(counters[i], bcnt, pcnt);
780	++i;
781	cond_resched();
782	}
783	}
784	}
785
786	static void get_old_counters(const struct xt_table_info *t,
787	struct xt_counters counters[])
788	{
789	struct ip6t_entry *iter;
790	unsigned int cpu, i;
791
792	for_each_possible_cpu(cpu) {
793	i = 0;
794	xt_entry_foreach(iter, t->entries, t->size) {
795	const struct xt_counters *tmp;
796
797	tmp = xt_get_per_cpu_counter(cnt: &iter->counters, cpu);
798	ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt);
799	++i;
800	}
801	cond_resched();
802	}
803	}
804
805	static struct xt_counters *alloc_counters(const struct xt_table *table)
806	{
807	unsigned int countersize;
808	struct xt_counters *counters;
809	const struct xt_table_info *private = table->private;
810
811	/* We need atomic snapshot of counters: rest doesn't change
812	(other than comefrom, which userspace doesn't care
813	about). */
814	countersize = sizeof(struct xt_counters) * private->number;
815	counters = vzalloc(countersize);
816
817	if (counters == NULL)
818	return ERR_PTR(error: -ENOMEM);
819
820	get_counters(t: private, counters);
821
822	return counters;
823	}
824
825	static int
826	copy_entries_to_user(unsigned int total_size,
827	const struct xt_table *table,
828	void __user *userptr)
829	{
830	unsigned int off, num;
831	const struct ip6t_entry *e;
832	struct xt_counters *counters;
833	const struct xt_table_info *private = table->private;
834	int ret = 0;
835	const void *loc_cpu_entry;
836
837	counters = alloc_counters(table);
838	if (IS_ERR(ptr: counters))
839	return PTR_ERR(ptr: counters);
840
841	loc_cpu_entry = private->entries;
842
843	/* FIXME: use iterator macros --RR */
844	/* ... then go back and fix counters and names */
845	for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
846	unsigned int i;
847	const struct xt_entry_match *m;
848	const struct xt_entry_target *t;
849
850	e = loc_cpu_entry + off;
851	if (copy_to_user(to: userptr + off, from: e, n: sizeof(*e))) {
852	ret = -EFAULT;
853	goto free_counters;
854	}
855	if (copy_to_user(to: userptr + off
856	+ offsetof(struct ip6t_entry, counters),
857	from: &counters[num],
858	n: sizeof(counters[num])) != 0) {
859	ret = -EFAULT;
860	goto free_counters;
861	}
862
863	for (i = sizeof(struct ip6t_entry);
864	i < e->target_offset;
865	i += m->u.match_size) {
866	m = (void *)e + i;
867
868	if (xt_match_to_user(m, u: userptr + off + i)) {
869	ret = -EFAULT;
870	goto free_counters;
871	}
872	}
873
874	t = ip6t_get_target_c(e);
875	if (xt_target_to_user(t, u: userptr + off + e->target_offset)) {
876	ret = -EFAULT;
877	goto free_counters;
878	}
879	}
880
881	free_counters:
882	vfree(addr: counters);
883	return ret;
884	}
885
886	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
887	static void compat_standard_from_user(void *dst, const void *src)
888	{
889	int v = *(compat_int_t *)src;
890
891	if (v > 0)
892	v += xt_compat_calc_jump(AF_INET6, offset: v);
893	memcpy(dst, &v, sizeof(v));
894	}
895
896	static int compat_standard_to_user(void __user *dst, const void *src)
897	{
898	compat_int_t cv = *(int *)src;
899
900	if (cv > 0)
901	cv -= xt_compat_calc_jump(AF_INET6, offset: cv);
902	return copy_to_user(to: dst, from: &cv, n: sizeof(cv)) ? -EFAULT : 0;
903	}
904
905	static int compat_calc_entry(const struct ip6t_entry *e,
906	const struct xt_table_info *info,
907	const void *base, struct xt_table_info *newinfo)
908	{
909	const struct xt_entry_match *ematch;
910	const struct xt_entry_target *t;
911	unsigned int entry_offset;
912	int off, i, ret;
913
914	off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
915	entry_offset = (void *)e - base;
916	xt_ematch_foreach(ematch, e)
917	off += xt_compat_match_offset(match: ematch->u.kernel.match);
918	t = ip6t_get_target_c(e);
919	off += xt_compat_target_offset(target: t->u.kernel.target);
920	newinfo->size -= off;
921	ret = xt_compat_add_offset(AF_INET6, offset: entry_offset, delta: off);
922	if (ret)
923	return ret;
924
925	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
926	if (info->hook_entry[i] &&
927	(e < (struct ip6t_entry *)(base + info->hook_entry[i])))
928	newinfo->hook_entry[i] -= off;
929	if (info->underflow[i] &&
930	(e < (struct ip6t_entry *)(base + info->underflow[i])))
931	newinfo->underflow[i] -= off;
932	}
933	return 0;
934	}
935
936	static int compat_table_info(const struct xt_table_info *info,
937	struct xt_table_info *newinfo)
938	{
939	struct ip6t_entry *iter;
940	const void *loc_cpu_entry;
941	int ret;
942
943	if (!newinfo || !info)
944	return -EINVAL;
945
946	/* we dont care about newinfo->entries */
947	memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
948	newinfo->initial_entries = 0;
949	loc_cpu_entry = info->entries;
950	ret = xt_compat_init_offsets(AF_INET6, number: info->number);
951	if (ret)
952	return ret;
953	xt_entry_foreach(iter, loc_cpu_entry, info->size) {
954	ret = compat_calc_entry(e: iter, info, base: loc_cpu_entry, newinfo);
955	if (ret != 0)
956	return ret;
957	}
958	return 0;
959	}
960	#endif
961
962	static int get_info(struct net *net, void __user *user, const int *len)
963	{
964	char name[XT_TABLE_MAXNAMELEN];
965	struct xt_table *t;
966	int ret;
967
968	if (*len != sizeof(struct ip6t_getinfo))
969	return -EINVAL;
970
971	if (copy_from_user(to: name, from: user, n: sizeof(name)) != 0)
972	return -EFAULT;
973
974	name[XT_TABLE_MAXNAMELEN-1] = '\0';
975	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
976	if (in_compat_syscall())
977	xt_compat_lock(AF_INET6);
978	#endif
979	t = xt_request_find_table_lock(net, AF_INET6, name);
980	if (!IS_ERR(ptr: t)) {
981	struct ip6t_getinfo info;
982	const struct xt_table_info *private = t->private;
983	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
984	struct xt_table_info tmp;
985
986	if (in_compat_syscall()) {
987	ret = compat_table_info(info: private, newinfo: &tmp);
988	xt_compat_flush_offsets(AF_INET6);
989	private = &tmp;
990	}
991	#endif
992	memset(&info, 0, sizeof(info));
993	info.valid_hooks = t->valid_hooks;
994	memcpy(info.hook_entry, private->hook_entry,
995	sizeof(info.hook_entry));
996	memcpy(info.underflow, private->underflow,
997	sizeof(info.underflow));
998	info.num_entries = private->number;
999	info.size = private->size;
1000	strcpy(p: info.name, q: name);
1001
1002	if (copy_to_user(to: user, from: &info, n: *len) != 0)
1003	ret = -EFAULT;
1004	else
1005	ret = 0;
1006
1007	xt_table_unlock(t);
1008	module_put(module: t->me);
1009	} else
1010	ret = PTR_ERR(ptr: t);
1011	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
1012	if (in_compat_syscall())
1013	xt_compat_unlock(AF_INET6);
1014	#endif
1015	return ret;
1016	}
1017
1018	static int
1019	get_entries(struct net *net, struct ip6t_get_entries __user *uptr,
1020	const int *len)
1021	{
1022	int ret;
1023	struct ip6t_get_entries get;
1024	struct xt_table *t;
1025
1026	if (*len < sizeof(get))
1027	return -EINVAL;
1028	if (copy_from_user(to: &get, from: uptr, n: sizeof(get)) != 0)
1029	return -EFAULT;
1030	if (*len != sizeof(struct ip6t_get_entries) + get.size)
1031	return -EINVAL;
1032
1033	get.name[sizeof(get.name) - 1] = '\0';
1034
1035	t = xt_find_table_lock(net, AF_INET6, name: get.name);
1036	if (!IS_ERR(ptr: t)) {
1037	struct xt_table_info *private = t->private;
1038	if (get.size == private->size)
1039	ret = copy_entries_to_user(total_size: private->size,
1040	table: t, userptr: uptr->entrytable);
1041	else
1042	ret = -EAGAIN;
1043
1044	module_put(module: t->me);
1045	xt_table_unlock(t);
1046	} else
1047	ret = PTR_ERR(ptr: t);
1048
1049	return ret;
1050	}
1051
1052	static int
1053	__do_replace(struct net *net, const char *name, unsigned int valid_hooks,
1054	struct xt_table_info *newinfo, unsigned int num_counters,
1055	void __user *counters_ptr)
1056	{
1057	int ret;
1058	struct xt_table *t;
1059	struct xt_table_info *oldinfo;
1060	struct xt_counters *counters;
1061	struct ip6t_entry *iter;
1062
1063	counters = xt_counters_alloc(counters: num_counters);
1064	if (!counters) {
1065	ret = -ENOMEM;
1066	goto out;
1067	}
1068
1069	t = xt_request_find_table_lock(net, AF_INET6, name);
1070	if (IS_ERR(ptr: t)) {
1071	ret = PTR_ERR(ptr: t);
1072	goto free_newinfo_counters_untrans;
1073	}
1074
1075	/* You lied! */
1076	if (valid_hooks != t->valid_hooks) {
1077	ret = -EINVAL;
1078	goto put_module;
1079	}
1080
1081	oldinfo = xt_replace_table(table: t, num_counters, newinfo, error: &ret);
1082	if (!oldinfo)
1083	goto put_module;
1084
1085	/* Update module usage count based on number of rules */
1086	if ((oldinfo->number > oldinfo->initial_entries) ||
1087	(newinfo->number <= oldinfo->initial_entries))
1088	module_put(module: t->me);
1089	if ((oldinfo->number > oldinfo->initial_entries) &&
1090	(newinfo->number <= oldinfo->initial_entries))
1091	module_put(module: t->me);
1092
1093	xt_table_unlock(t);
1094
1095	get_old_counters(t: oldinfo, counters);
1096
1097	/* Decrease module usage counts and free resource */
1098	xt_entry_foreach(iter, oldinfo->entries, oldinfo->size)
1099	cleanup_entry(e: iter, net);
1100
1101	xt_free_table_info(info: oldinfo);
1102	if (copy_to_user(to: counters_ptr, from: counters,
1103	n: sizeof(struct xt_counters) * num_counters) != 0) {
1104	/* Silent error, can't fail, new table is already in place */
1105	net_warn_ratelimited("ip6tables: counters copy to user failed while replacing table\n");
1106	}
1107	vfree(addr: counters);
1108	return 0;
1109
1110	put_module:
1111	module_put(module: t->me);
1112	xt_table_unlock(t);
1113	free_newinfo_counters_untrans:
1114	vfree(addr: counters);
1115	out:
1116	return ret;
1117	}
1118
1119	static int
1120	do_replace(struct net *net, sockptr_t arg, unsigned int len)
1121	{
1122	int ret;
1123	struct ip6t_replace tmp;
1124	struct xt_table_info *newinfo;
1125	void *loc_cpu_entry;
1126	struct ip6t_entry *iter;
1127
1128	if (len < sizeof(tmp))
1129	return -EINVAL;
1130	if (copy_from_sockptr(dst: &tmp, src: arg, size: sizeof(tmp)) != 0)
1131	return -EFAULT;
1132
1133	/* overflow check */
1134	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1135	return -ENOMEM;
1136	if (tmp.num_counters == 0)
1137	return -EINVAL;
1138	if ((u64)len < (u64)tmp.size + sizeof(tmp))
1139	return -EINVAL;
1140
1141	tmp.name[sizeof(tmp.name)-1] = 0;
1142
1143	newinfo = xt_alloc_table_info(size: tmp.size);
1144	if (!newinfo)
1145	return -ENOMEM;
1146
1147	loc_cpu_entry = newinfo->entries;
1148	if (copy_from_sockptr_offset(dst: loc_cpu_entry, src: arg, offset: sizeof(tmp),
1149	size: tmp.size) != 0) {
1150	ret = -EFAULT;
1151	goto free_newinfo;
1152	}
1153
1154	ret = translate_table(net, newinfo, entry0: loc_cpu_entry, repl: &tmp);
1155	if (ret != 0)
1156	goto free_newinfo;
1157
1158	ret = __do_replace(net, name: tmp.name, valid_hooks: tmp.valid_hooks, newinfo,
1159	num_counters: tmp.num_counters, counters_ptr: tmp.counters);
1160	if (ret)
1161	goto free_newinfo_untrans;
1162	return 0;
1163
1164	free_newinfo_untrans:
1165	xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1166	cleanup_entry(e: iter, net);
1167	free_newinfo:
1168	xt_free_table_info(info: newinfo);
1169	return ret;
1170	}
1171
1172	static int
1173	do_add_counters(struct net *net, sockptr_t arg, unsigned int len)
1174	{
1175	unsigned int i;
1176	struct xt_counters_info tmp;
1177	struct xt_counters *paddc;
1178	struct xt_table *t;
1179	const struct xt_table_info *private;
1180	int ret = 0;
1181	struct ip6t_entry *iter;
1182	unsigned int addend;
1183
1184	paddc = xt_copy_counters(arg, len, info: &tmp);
1185	if (IS_ERR(ptr: paddc))
1186	return PTR_ERR(ptr: paddc);
1187	t = xt_find_table_lock(net, AF_INET6, name: tmp.name);
1188	if (IS_ERR(ptr: t)) {
1189	ret = PTR_ERR(ptr: t);
1190	goto free;
1191	}
1192
1193	local_bh_disable();
1194	private = t->private;
1195	if (private->number != tmp.num_counters) {
1196	ret = -EINVAL;
1197	goto unlock_up_free;
1198	}
1199
1200	i = 0;
1201	addend = xt_write_recseq_begin();
1202	xt_entry_foreach(iter, private->entries, private->size) {
1203	struct xt_counters *tmp;
1204
1205	tmp = xt_get_this_cpu_counter(cnt: &iter->counters);
1206	ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt);
1207	++i;
1208	}
1209	xt_write_recseq_end(addend);
1210	unlock_up_free:
1211	local_bh_enable();
1212	xt_table_unlock(t);
1213	module_put(module: t->me);
1214	free:
1215	vfree(addr: paddc);
1216
1217	return ret;
1218	}
1219
1220	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
1221	struct compat_ip6t_replace {
1222	char name[XT_TABLE_MAXNAMELEN];
1223	u32 valid_hooks;
1224	u32 num_entries;
1225	u32 size;
1226	u32 hook_entry[NF_INET_NUMHOOKS];
1227	u32 underflow[NF_INET_NUMHOOKS];
1228	u32 num_counters;
1229	compat_uptr_t counters; /* struct xt_counters * */
1230	struct compat_ip6t_entry entries[];
1231	};
1232
1233	static int
1234	compat_copy_entry_to_user(struct ip6t_entry *e, void __user **dstptr,
1235	unsigned int *size, struct xt_counters *counters,
1236	unsigned int i)
1237	{
1238	struct xt_entry_target *t;
1239	struct compat_ip6t_entry __user *ce;
1240	u_int16_t target_offset, next_offset;
1241	compat_uint_t origsize;
1242	const struct xt_entry_match *ematch;
1243	int ret = 0;
1244
1245	origsize = *size;
1246	ce = *dstptr;
1247	if (copy_to_user(to: ce, from: e, n: sizeof(struct ip6t_entry)) != 0 ||
1248	copy_to_user(to: &ce->counters, from: &counters[i],
1249	n: sizeof(counters[i])) != 0)
1250	return -EFAULT;
1251
1252	*dstptr += sizeof(struct compat_ip6t_entry);
1253	*size -= sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1254
1255	xt_ematch_foreach(ematch, e) {
1256	ret = xt_compat_match_to_user(m: ematch, dstptr, size);
1257	if (ret != 0)
1258	return ret;
1259	}
1260	target_offset = e->target_offset - (origsize - *size);
1261	t = ip6t_get_target(e);
1262	ret = xt_compat_target_to_user(t, dstptr, size);
1263	if (ret)
1264	return ret;
1265	next_offset = e->next_offset - (origsize - *size);
1266	if (put_user(target_offset, &ce->target_offset) != 0 ||
1267	put_user(next_offset, &ce->next_offset) != 0)
1268	return -EFAULT;
1269	return 0;
1270	}
1271
1272	static int
1273	compat_find_calc_match(struct xt_entry_match *m,
1274	const struct ip6t_ip6 *ipv6,
1275	int *size)
1276	{
1277	struct xt_match *match;
1278
1279	match = xt_request_find_match(af: NFPROTO_IPV6, name: m->u.user.name,
1280	revision: m->u.user.revision);
1281	if (IS_ERR(ptr: match))
1282	return PTR_ERR(ptr: match);
1283
1284	m->u.kernel.match = match;
1285	*size += xt_compat_match_offset(match);
1286	return 0;
1287	}
1288
1289	static void compat_release_entry(struct compat_ip6t_entry *e)
1290	{
1291	struct xt_entry_target *t;
1292	struct xt_entry_match *ematch;
1293
1294	/* Cleanup all matches */
1295	xt_ematch_foreach(ematch, e)
1296	module_put(module: ematch->u.kernel.match->me);
1297	t = compat_ip6t_get_target(e);
1298	module_put(module: t->u.kernel.target->me);
1299	}
1300
1301	static int
1302	check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e,
1303	struct xt_table_info *newinfo,
1304	unsigned int *size,
1305	const unsigned char *base,
1306	const unsigned char *limit)
1307	{
1308	struct xt_entry_match *ematch;
1309	struct xt_entry_target *t;
1310	struct xt_target *target;
1311	unsigned int entry_offset;
1312	unsigned int j;
1313	int ret, off;
1314
1315	if ((unsigned long)e % __alignof__(struct compat_ip6t_entry) != 0 ||
1316	(unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit ||
1317	(unsigned char *)e + e->next_offset > limit)
1318	return -EINVAL;
1319
1320	if (e->next_offset < sizeof(struct compat_ip6t_entry) +
1321	sizeof(struct compat_xt_entry_target))
1322	return -EINVAL;
1323
1324	if (!ip6_checkentry(ipv6: &e->ipv6))
1325	return -EINVAL;
1326
1327	ret = xt_compat_check_entry_offsets(base: e, elems: e->elems,
1328	target_offset: e->target_offset, next_offset: e->next_offset);
1329	if (ret)
1330	return ret;
1331
1332	off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1333	entry_offset = (void *)e - (void *)base;
1334	j = 0;
1335	xt_ematch_foreach(ematch, e) {
1336	ret = compat_find_calc_match(m: ematch, ipv6: &e->ipv6, size: &off);
1337	if (ret != 0)
1338	goto release_matches;
1339	++j;
1340	}
1341
1342	t = compat_ip6t_get_target(e);
1343	target = xt_request_find_target(af: NFPROTO_IPV6, name: t->u.user.name,
1344	revision: t->u.user.revision);
1345	if (IS_ERR(ptr: target)) {
1346	ret = PTR_ERR(ptr: target);
1347	goto release_matches;
1348	}
1349	t->u.kernel.target = target;
1350
1351	off += xt_compat_target_offset(target);
1352	*size += off;
1353	ret = xt_compat_add_offset(AF_INET6, offset: entry_offset, delta: off);
1354	if (ret)
1355	goto out;
1356
1357	return 0;
1358
1359	out:
1360	module_put(module: t->u.kernel.target->me);
1361	release_matches:
1362	xt_ematch_foreach(ematch, e) {
1363	if (j-- == 0)
1364	break;
1365	module_put(module: ematch->u.kernel.match->me);
1366	}
1367	return ret;
1368	}
1369
1370	static void
1371	compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr,
1372	unsigned int *size,
1373	struct xt_table_info *newinfo, unsigned char *base)
1374	{
1375	struct xt_entry_target *t;
1376	struct ip6t_entry *de;
1377	unsigned int origsize;
1378	int h;
1379	struct xt_entry_match *ematch;
1380
1381	origsize = *size;
1382	de = *dstptr;
1383	memcpy(de, e, sizeof(struct ip6t_entry));
1384	memcpy(&de->counters, &e->counters, sizeof(e->counters));
1385
1386	*dstptr += sizeof(struct ip6t_entry);
1387	*size += sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1388
1389	xt_ematch_foreach(ematch, e)
1390	xt_compat_match_from_user(m: ematch, dstptr, size);
1391
1392	de->target_offset = e->target_offset - (origsize - *size);
1393	t = compat_ip6t_get_target(e);
1394	xt_compat_target_from_user(t, dstptr, size);
1395
1396	de->next_offset = e->next_offset - (origsize - *size);
1397	for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1398	if ((unsigned char *)de - base < newinfo->hook_entry[h])
1399	newinfo->hook_entry[h] -= origsize - *size;
1400	if ((unsigned char *)de - base < newinfo->underflow[h])
1401	newinfo->underflow[h] -= origsize - *size;
1402	}
1403	}
1404
1405	static int
1406	translate_compat_table(struct net *net,
1407	struct xt_table_info **pinfo,
1408	void **pentry0,
1409	const struct compat_ip6t_replace *compatr)
1410	{
1411	unsigned int i, j;
1412	struct xt_table_info *newinfo, *info;
1413	void *pos, *entry0, *entry1;
1414	struct compat_ip6t_entry *iter0;
1415	struct ip6t_replace repl;
1416	unsigned int size;
1417	int ret;
1418
1419	info = *pinfo;
1420	entry0 = *pentry0;
1421	size = compatr->size;
1422	info->number = compatr->num_entries;
1423
1424	j = 0;
1425	xt_compat_lock(AF_INET6);
1426	ret = xt_compat_init_offsets(AF_INET6, number: compatr->num_entries);
1427	if (ret)
1428	goto out_unlock;
1429	/* Walk through entries, checking offsets. */
1430	xt_entry_foreach(iter0, entry0, compatr->size) {
1431	ret = check_compat_entry_size_and_hooks(e: iter0, newinfo: info, size: &size,
1432	base: entry0,
1433	limit: entry0 + compatr->size);
1434	if (ret != 0)
1435	goto out_unlock;
1436	++j;
1437	}
1438
1439	ret = -EINVAL;
1440	if (j != compatr->num_entries)
1441	goto out_unlock;
1442
1443	ret = -ENOMEM;
1444	newinfo = xt_alloc_table_info(size);
1445	if (!newinfo)
1446	goto out_unlock;
1447
1448	memset(newinfo->entries, 0, size);
1449
1450	newinfo->number = compatr->num_entries;
1451	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1452	newinfo->hook_entry[i] = compatr->hook_entry[i];
1453	newinfo->underflow[i] = compatr->underflow[i];
1454	}
1455	entry1 = newinfo->entries;
1456	pos = entry1;
1457	size = compatr->size;
1458	xt_entry_foreach(iter0, entry0, compatr->size)
1459	compat_copy_entry_from_user(e: iter0, dstptr: &pos, size: &size,
1460	newinfo, base: entry1);
1461
1462	/* all module references in entry0 are now gone. */
1463	xt_compat_flush_offsets(AF_INET6);
1464	xt_compat_unlock(AF_INET6);
1465
1466	memcpy(&repl, compatr, sizeof(*compatr));
1467
1468	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1469	repl.hook_entry[i] = newinfo->hook_entry[i];
1470	repl.underflow[i] = newinfo->underflow[i];
1471	}
1472
1473	repl.num_counters = 0;
1474	repl.counters = NULL;
1475	repl.size = newinfo->size;
1476	ret = translate_table(net, newinfo, entry0: entry1, repl: &repl);
1477	if (ret)
1478	goto free_newinfo;
1479
1480	*pinfo = newinfo;
1481	*pentry0 = entry1;
1482	xt_free_table_info(info);
1483	return 0;
1484
1485	free_newinfo:
1486	xt_free_table_info(info: newinfo);
1487	return ret;
1488	out_unlock:
1489	xt_compat_flush_offsets(AF_INET6);
1490	xt_compat_unlock(AF_INET6);
1491	xt_entry_foreach(iter0, entry0, compatr->size) {
1492	if (j-- == 0)
1493	break;
1494	compat_release_entry(e: iter0);
1495	}
1496	return ret;
1497	}
1498
1499	static int
1500	compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
1501	{
1502	int ret;
1503	struct compat_ip6t_replace tmp;
1504	struct xt_table_info *newinfo;
1505	void *loc_cpu_entry;
1506	struct ip6t_entry *iter;
1507
1508	if (len < sizeof(tmp))
1509	return -EINVAL;
1510	if (copy_from_sockptr(dst: &tmp, src: arg, size: sizeof(tmp)) != 0)
1511	return -EFAULT;
1512
1513	/* overflow check */
1514	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1515	return -ENOMEM;
1516	if (tmp.num_counters == 0)
1517	return -EINVAL;
1518	if ((u64)len < (u64)tmp.size + sizeof(tmp))
1519	return -EINVAL;
1520
1521	tmp.name[sizeof(tmp.name)-1] = 0;
1522
1523	newinfo = xt_alloc_table_info(size: tmp.size);
1524	if (!newinfo)
1525	return -ENOMEM;
1526
1527	loc_cpu_entry = newinfo->entries;
1528	if (copy_from_sockptr_offset(dst: loc_cpu_entry, src: arg, offset: sizeof(tmp),
1529	size: tmp.size) != 0) {
1530	ret = -EFAULT;
1531	goto free_newinfo;
1532	}
1533
1534	ret = translate_compat_table(net, pinfo: &newinfo, pentry0: &loc_cpu_entry, compatr: &tmp);
1535	if (ret != 0)
1536	goto free_newinfo;
1537
1538	ret = __do_replace(net, name: tmp.name, valid_hooks: tmp.valid_hooks, newinfo,
1539	num_counters: tmp.num_counters, counters_ptr: compat_ptr(uptr: tmp.counters));
1540	if (ret)
1541	goto free_newinfo_untrans;
1542	return 0;
1543
1544	free_newinfo_untrans:
1545	xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1546	cleanup_entry(e: iter, net);
1547	free_newinfo:
1548	xt_free_table_info(info: newinfo);
1549	return ret;
1550	}
1551
1552	struct compat_ip6t_get_entries {
1553	char name[XT_TABLE_MAXNAMELEN];
1554	compat_uint_t size;
1555	struct compat_ip6t_entry entrytable[];
1556	};
1557
1558	static int
1559	compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
1560	void __user *userptr)
1561	{
1562	struct xt_counters *counters;
1563	const struct xt_table_info *private = table->private;
1564	void __user *pos;
1565	unsigned int size;
1566	int ret = 0;
1567	unsigned int i = 0;
1568	struct ip6t_entry *iter;
1569
1570	counters = alloc_counters(table);
1571	if (IS_ERR(ptr: counters))
1572	return PTR_ERR(ptr: counters);
1573
1574	pos = userptr;
1575	size = total_size;
1576	xt_entry_foreach(iter, private->entries, total_size) {
1577	ret = compat_copy_entry_to_user(e: iter, dstptr: &pos,
1578	size: &size, counters, i: i++);
1579	if (ret != 0)
1580	break;
1581	}
1582
1583	vfree(addr: counters);
1584	return ret;
1585	}
1586
1587	static int
1588	compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr,
1589	int *len)
1590	{
1591	int ret;
1592	struct compat_ip6t_get_entries get;
1593	struct xt_table *t;
1594
1595	if (*len < sizeof(get))
1596	return -EINVAL;
1597
1598	if (copy_from_user(to: &get, from: uptr, n: sizeof(get)) != 0)
1599	return -EFAULT;
1600
1601	if (*len != sizeof(struct compat_ip6t_get_entries) + get.size)
1602	return -EINVAL;
1603
1604	get.name[sizeof(get.name) - 1] = '\0';
1605
1606	xt_compat_lock(AF_INET6);
1607	t = xt_find_table_lock(net, AF_INET6, name: get.name);
1608	if (!IS_ERR(ptr: t)) {
1609	const struct xt_table_info *private = t->private;
1610	struct xt_table_info info;
1611	ret = compat_table_info(info: private, newinfo: &info);
1612	if (!ret && get.size == info.size)
1613	ret = compat_copy_entries_to_user(total_size: private->size,
1614	table: t, userptr: uptr->entrytable);
1615	else if (!ret)
1616	ret = -EAGAIN;
1617
1618	xt_compat_flush_offsets(AF_INET6);
1619	module_put(module: t->me);
1620	xt_table_unlock(t);
1621	} else
1622	ret = PTR_ERR(ptr: t);
1623
1624	xt_compat_unlock(AF_INET6);
1625	return ret;
1626	}
1627	#endif
1628
1629	static int
1630	do_ip6t_set_ctl(struct sock *sk, int cmd, sockptr_t arg, unsigned int len)
1631	{
1632	int ret;
1633
1634	if (!ns_capable(ns: sock_net(sk)->user_ns, CAP_NET_ADMIN))
1635	return -EPERM;
1636
1637	switch (cmd) {
1638	case IP6T_SO_SET_REPLACE:
1639	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
1640	if (in_compat_syscall())
1641	ret = compat_do_replace(net: sock_net(sk), arg, len);
1642	else
1643	#endif
1644	ret = do_replace(net: sock_net(sk), arg, len);
1645	break;
1646
1647	case IP6T_SO_SET_ADD_COUNTERS:
1648	ret = do_add_counters(net: sock_net(sk), arg, len);
1649	break;
1650
1651	default:
1652	ret = -EINVAL;
1653	}
1654
1655	return ret;
1656	}
1657
1658	static int
1659	do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1660	{
1661	int ret;
1662
1663	if (!ns_capable(ns: sock_net(sk)->user_ns, CAP_NET_ADMIN))
1664	return -EPERM;
1665
1666	switch (cmd) {
1667	case IP6T_SO_GET_INFO:
1668	ret = get_info(net: sock_net(sk), user, len);
1669	break;
1670
1671	case IP6T_SO_GET_ENTRIES:
1672	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
1673	if (in_compat_syscall())
1674	ret = compat_get_entries(net: sock_net(sk), uptr: user, len);
1675	else
1676	#endif
1677	ret = get_entries(net: sock_net(sk), uptr: user, len);
1678	break;
1679
1680	case IP6T_SO_GET_REVISION_MATCH:
1681	case IP6T_SO_GET_REVISION_TARGET: {
1682	struct xt_get_revision rev;
1683	int target;
1684
1685	if (*len != sizeof(rev)) {
1686	ret = -EINVAL;
1687	break;
1688	}
1689	if (copy_from_user(to: &rev, from: user, n: sizeof(rev)) != 0) {
1690	ret = -EFAULT;
1691	break;
1692	}
1693	rev.name[sizeof(rev.name)-1] = 0;
1694
1695	if (cmd == IP6T_SO_GET_REVISION_TARGET)
1696	target = 1;
1697	else
1698	target = 0;
1699
1700	try_then_request_module(xt_find_revision(AF_INET6, rev.name,
1701	rev.revision,
1702	target, &ret),
1703	"ip6t_%s", rev.name);
1704	break;
1705	}
1706
1707	default:
1708	ret = -EINVAL;
1709	}
1710
1711	return ret;
1712	}
1713
1714	static void __ip6t_unregister_table(struct net *net, struct xt_table *table)
1715	{
1716	struct xt_table_info *private;
1717	void *loc_cpu_entry;
1718	struct module *table_owner = table->me;
1719	struct ip6t_entry *iter;
1720
1721	private = xt_unregister_table(table);
1722
1723	/* Decrease module usage counts and free resources */
1724	loc_cpu_entry = private->entries;
1725	xt_entry_foreach(iter, loc_cpu_entry, private->size)
1726	cleanup_entry(e: iter, net);
1727	if (private->number > private->initial_entries)
1728	module_put(module: table_owner);
1729	xt_free_table_info(info: private);
1730	}
1731
1732	int ip6t_register_table(struct net *net, const struct xt_table *table,
1733	const struct ip6t_replace *repl,
1734	const struct nf_hook_ops *template_ops)
1735	{
1736	struct nf_hook_ops *ops;
1737	unsigned int num_ops;
1738	int ret, i;
1739	struct xt_table_info *newinfo;
1740	struct xt_table_info bootstrap = {0};
1741	void *loc_cpu_entry;
1742	struct xt_table *new_table;
1743
1744	newinfo = xt_alloc_table_info(size: repl->size);
1745	if (!newinfo)
1746	return -ENOMEM;
1747
1748	loc_cpu_entry = newinfo->entries;
1749	memcpy(loc_cpu_entry, repl->entries, repl->size);
1750
1751	ret = translate_table(net, newinfo, entry0: loc_cpu_entry, repl);
1752	if (ret != 0) {
1753	xt_free_table_info(info: newinfo);
1754	return ret;
1755	}
1756
1757	new_table = xt_register_table(net, table, bootstrap: &bootstrap, newinfo);
1758	if (IS_ERR(ptr: new_table)) {
1759	struct ip6t_entry *iter;
1760
1761	xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1762	cleanup_entry(e: iter, net);
1763	xt_free_table_info(info: newinfo);
1764	return PTR_ERR(ptr: new_table);
1765	}
1766
1767	if (!template_ops)
1768	return 0;
1769
1770	num_ops = hweight32(table->valid_hooks);
1771	if (num_ops == 0) {
1772	ret = -EINVAL;
1773	goto out_free;
1774	}
1775
1776	ops = kmemdup_array(src: template_ops, count: num_ops, element_size: sizeof(*ops), GFP_KERNEL);
1777	if (!ops) {
1778	ret = -ENOMEM;
1779	goto out_free;
1780	}
1781
1782	for (i = 0; i < num_ops; i++)
1783	ops[i].priv = new_table;
1784
1785	new_table->ops = ops;
1786
1787	ret = nf_register_net_hooks(net, reg: ops, n: num_ops);
1788	if (ret != 0)
1789	goto out_free;
1790
1791	return ret;
1792
1793	out_free:
1794	__ip6t_unregister_table(net, table: new_table);
1795	return ret;
1796	}
1797
1798	void ip6t_unregister_table_pre_exit(struct net *net, const char *name)
1799	{
1800	struct xt_table *table = xt_find_table(net, af: NFPROTO_IPV6, name);
1801
1802	if (table)
1803	nf_unregister_net_hooks(net, reg: table->ops, hweight32(table->valid_hooks));
1804	}
1805
1806	void ip6t_unregister_table_exit(struct net *net, const char *name)
1807	{
1808	struct xt_table *table = xt_find_table(net, af: NFPROTO_IPV6, name);
1809
1810	if (table)
1811	__ip6t_unregister_table(net, table);
1812	}
1813
1814	/* The built-in targets: standard (NULL) and error. */
1815	static struct xt_target ip6t_builtin_tg[] __read_mostly = {
1816	{
1817	.name = XT_STANDARD_TARGET,
1818	.targetsize = sizeof(int),
1819	.family = NFPROTO_IPV6,
1820	#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
1821	.compatsize = sizeof(compat_int_t),
1822	.compat_from_user = compat_standard_from_user,
1823	.compat_to_user = compat_standard_to_user,
1824	#endif
1825	},
1826	{
1827	.name = XT_ERROR_TARGET,
1828	.target = ip6t_error,
1829	.targetsize = XT_FUNCTION_MAXNAMELEN,
1830	.family = NFPROTO_IPV6,
1831	},
1832	};
1833
1834	static struct nf_sockopt_ops ip6t_sockopts = {
1835	.pf = PF_INET6,
1836	.set_optmin = IP6T_BASE_CTL,
1837	.set_optmax = IP6T_SO_SET_MAX+1,
1838	.set = do_ip6t_set_ctl,
1839	.get_optmin = IP6T_BASE_CTL,
1840	.get_optmax = IP6T_SO_GET_MAX+1,
1841	.get = do_ip6t_get_ctl,
1842	.owner = THIS_MODULE,
1843	};
1844
1845	static int __net_init ip6_tables_net_init(struct net *net)
1846	{
1847	return xt_proto_init(net, af: NFPROTO_IPV6);
1848	}
1849
1850	static void __net_exit ip6_tables_net_exit(struct net *net)
1851	{
1852	xt_proto_fini(net, af: NFPROTO_IPV6);
1853	}
1854
1855	static struct pernet_operations ip6_tables_net_ops = {
1856	.init = ip6_tables_net_init,
1857	.exit = ip6_tables_net_exit,
1858	};
1859
1860	static int __init ip6_tables_init(void)
1861	{
1862	int ret;
1863
1864	ret = register_pernet_subsys(&ip6_tables_net_ops);
1865	if (ret < 0)
1866	goto err1;
1867
1868	/* No one else will be downing sem now, so we won't sleep */
1869	ret = xt_register_targets(target: ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
1870	if (ret < 0)
1871	goto err2;
1872
1873	/* Register setsockopt */
1874	ret = nf_register_sockopt(reg: &ip6t_sockopts);
1875	if (ret < 0)
1876	goto err4;
1877
1878	return 0;
1879
1880	err4:
1881	xt_unregister_targets(target: ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
1882	err2:
1883	unregister_pernet_subsys(&ip6_tables_net_ops);
1884	err1:
1885	return ret;
1886	}
1887
1888	static void __exit ip6_tables_fini(void)
1889	{
1890	nf_unregister_sockopt(reg: &ip6t_sockopts);
1891
1892	xt_unregister_targets(target: ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
1893	unregister_pernet_subsys(&ip6_tables_net_ops);
1894	}
1895
1896	EXPORT_SYMBOL(ip6t_register_table);
1897	EXPORT_SYMBOL(ip6t_unregister_table_pre_exit);
1898	EXPORT_SYMBOL(ip6t_unregister_table_exit);
1899	EXPORT_SYMBOL(ip6t_do_table);
1900
1901	module_init(ip6_tables_init);
1902	module_exit(ip6_tables_fini);
1903