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 <linux/icmpv6.h>
22 #include <net/ipv6.h>
23 #include <net/compat.h>
24 #include <linux/uaccess.h>
25 #include <linux/mutex.h>
26 #include <linux/proc_fs.h>
27 #include <linux/err.h>
28 #include <linux/cpumask.h>
29
30 #include <linux/netfilter_ipv6/ip6_tables.h>
31 #include <linux/netfilter/x_tables.h>
32 #include <net/netfilter/nf_log.h>
33 #include "../../netfilter/xt_repldata.h"
34
35 MODULE_LICENSE("GPL");
36 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
37 MODULE_DESCRIPTION("IPv6 packet filter");
38 MODULE_ALIAS("ip6t_icmp6");
39
40 void *ip6t_alloc_initial_table(const struct xt_table *info)
41 {
42 return xt_alloc_initial_table(ip6t, IP6T);
43 }
44 EXPORT_SYMBOL_GPL(ip6t_alloc_initial_table);
45
46 /* Returns whether matches rule or not. */
47 /* Performance critical - called for every packet */
48 static inline bool
49 ip6_packet_match(const struct sk_buff *skb,
50 const char *indev,
51 const char *outdev,
52 const struct ip6t_ip6 *ip6info,
53 unsigned int *protoff,
54 int *fragoff, bool *hotdrop)
55 {
56 unsigned long ret;
57 const struct ipv6hdr *ipv6 = ipv6_hdr(skb);
58
59 if (NF_INVF(ip6info, IP6T_INV_SRCIP,
60 ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk,
61 &ip6info->src)) ||
62 NF_INVF(ip6info, IP6T_INV_DSTIP,
63 ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk,
64 &ip6info->dst)))
65 return false;
66
67 ret = ifname_compare_aligned(indev, ip6info->iniface, ip6info->iniface_mask);
68
69 if (NF_INVF(ip6info, IP6T_INV_VIA_IN, ret != 0))
70 return false;
71
72 ret = ifname_compare_aligned(outdev, ip6info->outiface, ip6info->outiface_mask);
73
74 if (NF_INVF(ip6info, IP6T_INV_VIA_OUT, ret != 0))
75 return false;
76
77 /* ... might want to do something with class and flowlabel here ... */
78
79 /* look for the desired protocol header */
80 if (ip6info->flags & IP6T_F_PROTO) {
81 int protohdr;
82 unsigned short _frag_off;
83
84 protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off, NULL);
85 if (protohdr < 0) {
86 if (_frag_off == 0)
87 *hotdrop = true;
88 return false;
89 }
90 *fragoff = _frag_off;
91
92 if (ip6info->proto == protohdr) {
93 if (ip6info->invflags & IP6T_INV_PROTO)
94 return false;
95
96 return true;
97 }
98
99 /* We need match for the '-p all', too! */
100 if ((ip6info->proto != 0) &&
101 !(ip6info->invflags & IP6T_INV_PROTO))
102 return false;
103 }
104 return true;
105 }
106
107 /* should be ip6 safe */
108 static bool
109 ip6_checkentry(const struct ip6t_ip6 *ipv6)
110 {
111 if (ipv6->flags & ~IP6T_F_MASK)
112 return false;
113 if (ipv6->invflags & ~IP6T_INV_MASK)
114 return false;
115
116 return true;
117 }
118
119 static unsigned int
120 ip6t_error(struct sk_buff *skb, const struct xt_action_param *par)
121 {
122 net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo);
123
124 return NF_DROP;
125 }
126
127 static inline struct ip6t_entry *
128 get_entry(const void *base, unsigned int offset)
129 {
130 return (struct ip6t_entry *)(base + offset);
131 }
132
133 /* All zeroes == unconditional rule. */
134 /* Mildly perf critical (only if packet tracing is on) */
135 static inline bool unconditional(const struct ip6t_entry *e)
136 {
137 static const struct ip6t_ip6 uncond;
138
139 return e->target_offset == sizeof(struct ip6t_entry) &&
140 memcmp(&e->ipv6, &uncond, sizeof(uncond)) == 0;
141 }
142
143 static inline const struct xt_entry_target *
144 ip6t_get_target_c(const struct ip6t_entry *e)
145 {
146 return ip6t_get_target((struct ip6t_entry *)e);
147 }
148
149 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
150 /* This cries for unification! */
151 static const char *const hooknames[] = {
152 [NF_INET_PRE_ROUTING] = "PREROUTING",
153 [NF_INET_LOCAL_IN] = "INPUT",
154 [NF_INET_FORWARD] = "FORWARD",
155 [NF_INET_LOCAL_OUT] = "OUTPUT",
156 [NF_INET_POST_ROUTING] = "POSTROUTING",
157 };
158
159 enum nf_ip_trace_comments {
160 NF_IP6_TRACE_COMMENT_RULE,
161 NF_IP6_TRACE_COMMENT_RETURN,
162 NF_IP6_TRACE_COMMENT_POLICY,
163 };
164
165 static const char *const comments[] = {
166 [NF_IP6_TRACE_COMMENT_RULE] = "rule",
167 [NF_IP6_TRACE_COMMENT_RETURN] = "return",
168 [NF_IP6_TRACE_COMMENT_POLICY] = "policy",
169 };
170
171 static const struct nf_loginfo trace_loginfo = {
172 .type = NF_LOG_TYPE_LOG,
173 .u = {
174 .log = {
175 .level = LOGLEVEL_WARNING,
176 .logflags = NF_LOG_DEFAULT_MASK,
177 },
178 },
179 };
180
181 /* Mildly perf critical (only if packet tracing is on) */
182 static inline int
183 get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e,
184 const char *hookname, const char **chainname,
185 const char **comment, unsigned int *rulenum)
186 {
187 const struct xt_standard_target *t = (void *)ip6t_get_target_c(s);
188
189 if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) {
190 /* Head of user chain: ERROR target with chainname */
191 *chainname = t->target.data;
192 (*rulenum) = 0;
193 } else if (s == e) {
194 (*rulenum)++;
195
196 if (unconditional(s) &&
197 strcmp(t->target.u.kernel.target->name,
198 XT_STANDARD_TARGET) == 0 &&
199 t->verdict < 0) {
200 /* Tail of chains: STANDARD target (return/policy) */
201 *comment = *chainname == hookname
202 ? comments[NF_IP6_TRACE_COMMENT_POLICY]
203 : comments[NF_IP6_TRACE_COMMENT_RETURN];
204 }
205 return 1;
206 } else
207 (*rulenum)++;
208
209 return 0;
210 }
211
212 static void trace_packet(struct net *net,
213 const struct sk_buff *skb,
214 unsigned int hook,
215 const struct net_device *in,
216 const struct net_device *out,
217 const char *tablename,
218 const struct xt_table_info *private,
219 const struct ip6t_entry *e)
220 {
221 const struct ip6t_entry *root;
222 const char *hookname, *chainname, *comment;
223 const struct ip6t_entry *iter;
224 unsigned int rulenum = 0;
225
226 root = get_entry(private->entries, private->hook_entry[hook]);
227
228 hookname = chainname = hooknames[hook];
229 comment = comments[NF_IP6_TRACE_COMMENT_RULE];
230
231 xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
232 if (get_chainname_rulenum(iter, e, hookname,
233 &chainname, &comment, &rulenum) != 0)
234 break;
235
236 nf_log_trace(net, AF_INET6, hook, skb, in, out, &trace_loginfo,
237 "TRACE: %s:%s:%s:%u ",
238 tablename, chainname, comment, rulenum);
239 }
240 #endif
241
242 static inline struct ip6t_entry *
243 ip6t_next_entry(const struct ip6t_entry *entry)
244 {
245 return (void *)entry + entry->next_offset;
246 }
247
248 /* Returns one of the generic firewall policies, like NF_ACCEPT. */
249 unsigned int
250 ip6t_do_table(struct sk_buff *skb,
251 const struct nf_hook_state *state,
252 struct xt_table *table)
253 {
254 unsigned int hook = state->hook;
255 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
256 /* Initializing verdict to NF_DROP keeps gcc happy. */
257 unsigned int verdict = NF_DROP;
258 const char *indev, *outdev;
259 const void *table_base;
260 struct ip6t_entry *e, **jumpstack;
261 unsigned int stackidx, cpu;
262 const struct xt_table_info *private;
263 struct xt_action_param acpar;
264 unsigned int addend;
265
266 /* Initialization */
267 stackidx = 0;
268 indev = state->in ? state->in->name : nulldevname;
269 outdev = state->out ? state->out->name : nulldevname;
270 /* We handle fragments by dealing with the first fragment as
271 * if it was a normal packet. All other fragments are treated
272 * normally, except that they will NEVER match rules that ask
273 * things we don't know, ie. tcp syn flag or ports). If the
274 * rule is also a fragment-specific rule, non-fragments won't
275 * match it. */
276 acpar.hotdrop = false;
277 acpar.state = state;
278
279 WARN_ON(!(table->valid_hooks & (1 << hook)));
280
281 local_bh_disable();
282 addend = xt_write_recseq_begin();
283 private = READ_ONCE(table->private); /* Address dependency. */
284 cpu = smp_processor_id();
285 table_base = private->entries;
286 jumpstack = (struct ip6t_entry **)private->jumpstack[cpu];
287
288 /* Switch to alternate jumpstack if we're being invoked via TEE.
289 * TEE issues XT_CONTINUE verdict on original skb so we must not
290 * clobber the jumpstack.
291 *
292 * For recursion via REJECT or SYNPROXY the stack will be clobbered
293 * but it is no problem since absolute verdict is issued by these.
294 */
295 if (static_key_false(&xt_tee_enabled))
296 jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
297
298 e = get_entry(table_base, private->hook_entry[hook]);
299
300 do {
301 const struct xt_entry_target *t;
302 const struct xt_entry_match *ematch;
303 struct xt_counters *counter;
304
305 WARN_ON(!e);
306 acpar.thoff = 0;
307 if (!ip6_packet_match(skb, indev, outdev, &e->ipv6,
308 &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) {
309 no_match:
310 e = ip6t_next_entry(e);
311 continue;
312 }
313
314 xt_ematch_foreach(ematch, e) {
315 acpar.match = ematch->u.kernel.match;
316 acpar.matchinfo = ematch->data;
317 if (!acpar.match->match(skb, &acpar))
318 goto no_match;
319 }
320
321 counter = xt_get_this_cpu_counter(&e->counters);
322 ADD_COUNTER(*counter, skb->len, 1);
323
324 t = ip6t_get_target_c(e);
325 WARN_ON(!t->u.kernel.target);
326
327 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
328 /* The packet is traced: log it */
329 if (unlikely(skb->nf_trace))
330 trace_packet(state->net, skb, hook, state->in,
331 state->out, table->name, private, e);
332 #endif
333 /* Standard target? */
334 if (!t->u.kernel.target->target) {
335 int v;
336
337 v = ((struct xt_standard_target *)t)->verdict;
338 if (v < 0) {
339 /* Pop from stack? */
340 if (v != XT_RETURN) {
341 verdict = (unsigned int)(-v) - 1;
342 break;
343 }
344 if (stackidx == 0)
345 e = get_entry(table_base,
346 private->underflow[hook]);
347 else
348 e = ip6t_next_entry(jumpstack[--stackidx]);
349 continue;
350 }
351 if (table_base + v != ip6t_next_entry(e) &&
352 !(e->ipv6.flags & IP6T_F_GOTO)) {
353 if (unlikely(stackidx >= private->stacksize)) {
354 verdict = NF_DROP;
355 break;
356 }
357 jumpstack[stackidx++] = e;
358 }
359
360 e = get_entry(table_base, v);
361 continue;
362 }
363
364 acpar.target = t->u.kernel.target;
365 acpar.targinfo = t->data;
366
367 verdict = t->u.kernel.target->target(skb, &acpar);
368 if (verdict == XT_CONTINUE)
369 e = ip6t_next_entry(e);
370 else
371 /* Verdict */
372 break;
373 } while (!acpar.hotdrop);
374
375 xt_write_recseq_end(addend);
376 local_bh_enable();
377
378 if (acpar.hotdrop)
379 return NF_DROP;
380 else return verdict;
381 }
382
383 /* Figures out from what hook each rule can be called: returns 0 if
384 there are loops. Puts hook bitmask in comefrom. */
385 static int
386 mark_source_chains(const struct xt_table_info *newinfo,
387 unsigned int valid_hooks, void *entry0,
388 unsigned int *offsets)
389 {
390 unsigned int hook;
391
392 /* No recursion; use packet counter to save back ptrs (reset
393 to 0 as we leave), and comefrom to save source hook bitmask */
394 for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
395 unsigned int pos = newinfo->hook_entry[hook];
396 struct ip6t_entry *e = entry0 + pos;
397
398 if (!(valid_hooks & (1 << hook)))
399 continue;
400
401 /* Set initial back pointer. */
402 e->counters.pcnt = pos;
403
404 for (;;) {
405 const struct xt_standard_target *t
406 = (void *)ip6t_get_target_c(e);
407 int visited = e->comefrom & (1 << hook);
408
409 if (e->comefrom & (1 << NF_INET_NUMHOOKS))
410 return 0;
411
412 e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
413
414 /* Unconditional return/END. */
415 if ((unconditional(e) &&
416 (strcmp(t->target.u.user.name,
417 XT_STANDARD_TARGET) == 0) &&
418 t->verdict < 0) || visited) {
419 unsigned int oldpos, size;
420
421 /* Return: backtrack through the last
422 big jump. */
423 do {
424 e->comefrom ^= (1<<NF_INET_NUMHOOKS);
425 oldpos = pos;
426 pos = e->counters.pcnt;
427 e->counters.pcnt = 0;
428
429 /* We're at the start. */
430 if (pos == oldpos)
431 goto next;
432
433 e = entry0 + pos;
434 } while (oldpos == pos + e->next_offset);
435
436 /* Move along one */
437 size = e->next_offset;
438 e = entry0 + pos + size;
439 if (pos + size >= newinfo->size)
440 return 0;
441 e->counters.pcnt = pos;
442 pos += size;
443 } else {
444 int newpos = t->verdict;
445
446 if (strcmp(t->target.u.user.name,
447 XT_STANDARD_TARGET) == 0 &&
448 newpos >= 0) {
449 /* This a jump; chase it. */
450 if (!xt_find_jump_offset(offsets, newpos,
451 newinfo->number))
452 return 0;
453 } else {
454 /* ... this is a fallthru */
455 newpos = pos + e->next_offset;
456 if (newpos >= newinfo->size)
457 return 0;
458 }
459 e = entry0 + newpos;
460 e->counters.pcnt = pos;
461 pos = newpos;
462 }
463 }
464 next: ;
465 }
466 return 1;
467 }
468
469 static void cleanup_match(struct xt_entry_match *m, struct net *net)
470 {
471 struct xt_mtdtor_param par;
472
473 par.net = net;
474 par.match = m->u.kernel.match;
475 par.matchinfo = m->data;
476 par.family = NFPROTO_IPV6;
477 if (par.match->destroy != NULL)
478 par.match->destroy(&par);
479 module_put(par.match->me);
480 }
481
482 static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
483 {
484 const struct ip6t_ip6 *ipv6 = par->entryinfo;
485
486 par->match = m->u.kernel.match;
487 par->matchinfo = m->data;
488
489 return xt_check_match(par, m->u.match_size - sizeof(*m),
490 ipv6->proto, ipv6->invflags & IP6T_INV_PROTO);
491 }
492
493 static int
494 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
495 {
496 struct xt_match *match;
497 int ret;
498
499 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name,
500 m->u.user.revision);
501 if (IS_ERR(match))
502 return PTR_ERR(match);
503
504 m->u.kernel.match = match;
505
506 ret = check_match(m, par);
507 if (ret)
508 goto err;
509
510 return 0;
511 err:
512 module_put(m->u.kernel.match->me);
513 return ret;
514 }
515
516 static int check_target(struct ip6t_entry *e, struct net *net, const char *name)
517 {
518 struct xt_entry_target *t = ip6t_get_target(e);
519 struct xt_tgchk_param par = {
520 .net = net,
521 .table = name,
522 .entryinfo = e,
523 .target = t->u.kernel.target,
524 .targinfo = t->data,
525 .hook_mask = e->comefrom,
526 .family = NFPROTO_IPV6,
527 };
528
529 return xt_check_target(&par, t->u.target_size - sizeof(*t),
530 e->ipv6.proto,
531 e->ipv6.invflags & IP6T_INV_PROTO);
532 }
533
534 static int
535 find_check_entry(struct ip6t_entry *e, struct net *net, const char *name,
536 unsigned int size,
537 struct xt_percpu_counter_alloc_state *alloc_state)
538 {
539 struct xt_entry_target *t;
540 struct xt_target *target;
541 int ret;
542 unsigned int j;
543 struct xt_mtchk_param mtpar;
544 struct xt_entry_match *ematch;
545
546 if (!xt_percpu_counter_alloc(alloc_state, &e->counters))
547 return -ENOMEM;
548
549 j = 0;
550 memset(&mtpar, 0, sizeof(mtpar));
551 mtpar.net = net;
552 mtpar.table = name;
553 mtpar.entryinfo = &e->ipv6;
554 mtpar.hook_mask = e->comefrom;
555 mtpar.family = NFPROTO_IPV6;
556 xt_ematch_foreach(ematch, e) {
557 ret = find_check_match(ematch, &mtpar);
558 if (ret != 0)
559 goto cleanup_matches;
560 ++j;
561 }
562
563 t = ip6t_get_target(e);
564 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name,
565 t->u.user.revision);
566 if (IS_ERR(target)) {
567 ret = PTR_ERR(target);
568 goto cleanup_matches;
569 }
570 t->u.kernel.target = target;
571
572 ret = check_target(e, net, name);
573 if (ret)
574 goto err;
575 return 0;
576 err:
577 module_put(t->u.kernel.target->me);
578 cleanup_matches:
579 xt_ematch_foreach(ematch, e) {
580 if (j-- == 0)
581 break;
582 cleanup_match(ematch, net);
583 }
584
585 xt_percpu_counter_free(&e->counters);
586
587 return ret;
588 }
589
590 static bool check_underflow(const struct ip6t_entry *e)
591 {
592 const struct xt_entry_target *t;
593 unsigned int verdict;
594
595 if (!unconditional(e))
596 return false;
597 t = ip6t_get_target_c(e);
598 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
599 return false;
600 verdict = ((struct xt_standard_target *)t)->verdict;
601 verdict = -verdict - 1;
602 return verdict == NF_DROP || verdict == NF_ACCEPT;
603 }
604
605 static int
606 check_entry_size_and_hooks(struct ip6t_entry *e,
607 struct xt_table_info *newinfo,
608 const unsigned char *base,
609 const unsigned char *limit,
610 const unsigned int *hook_entries,
611 const unsigned int *underflows,
612 unsigned int valid_hooks)
613 {
614 unsigned int h;
615 int err;
616
617 if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 ||
618 (unsigned char *)e + sizeof(struct ip6t_entry) >= limit ||
619 (unsigned char *)e + e->next_offset > limit)
620 return -EINVAL;
621
622 if (e->next_offset
623 < sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target))
624 return -EINVAL;
625
626 if (!ip6_checkentry(&e->ipv6))
627 return -EINVAL;
628
629 err = xt_check_entry_offsets(e, e->elems, e->target_offset,
630 e->next_offset);
631 if (err)
632 return err;
633
634 /* Check hooks & underflows */
635 for (h = 0; h < NF_INET_NUMHOOKS; h++) {
636 if (!(valid_hooks & (1 << h)))
637 continue;
638 if ((unsigned char *)e - base == hook_entries[h])
639 newinfo->hook_entry[h] = hook_entries[h];
640 if ((unsigned char *)e - base == underflows[h]) {
641 if (!check_underflow(e))
642 return -EINVAL;
643
644 newinfo->underflow[h] = underflows[h];
645 }
646 }
647
648 /* Clear counters and comefrom */
649 e->counters = ((struct xt_counters) { 0, 0 });
650 e->comefrom = 0;
651 return 0;
652 }
653
654 static void cleanup_entry(struct ip6t_entry *e, struct net *net)
655 {
656 struct xt_tgdtor_param par;
657 struct xt_entry_target *t;
658 struct xt_entry_match *ematch;
659
660 /* Cleanup all matches */
661 xt_ematch_foreach(ematch, e)
662 cleanup_match(ematch, net);
663 t = ip6t_get_target(e);
664
665 par.net = net;
666 par.target = t->u.kernel.target;
667 par.targinfo = t->data;
668 par.family = NFPROTO_IPV6;
669 if (par.target->destroy != NULL)
670 par.target->destroy(&par);
671 module_put(par.target->me);
672 xt_percpu_counter_free(&e->counters);
673 }
674
675 /* Checks and translates the user-supplied table segment (held in
676 newinfo) */
677 static int
678 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
679 const struct ip6t_replace *repl)
680 {
681 struct xt_percpu_counter_alloc_state alloc_state = { 0 };
682 struct ip6t_entry *iter;
683 unsigned int *offsets;
684 unsigned int i;
685 int ret = 0;
686
687 newinfo->size = repl->size;
688 newinfo->number = repl->num_entries;
689
690 /* Init all hooks to impossible value. */
691 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
692 newinfo->hook_entry[i] = 0xFFFFFFFF;
693 newinfo->underflow[i] = 0xFFFFFFFF;
694 }
695
696 offsets = xt_alloc_entry_offsets(newinfo->number);
697 if (!offsets)
698 return -ENOMEM;
699 i = 0;
700 /* Walk through entries, checking offsets. */
701 xt_entry_foreach(iter, entry0, newinfo->size) {
702 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
703 entry0 + repl->size,
704 repl->hook_entry,
705 repl->underflow,
706 repl->valid_hooks);
707 if (ret != 0)
708 goto out_free;
709 if (i < repl->num_entries)
710 offsets[i] = (void *)iter - entry0;
711 ++i;
712 if (strcmp(ip6t_get_target(iter)->u.user.name,
713 XT_ERROR_TARGET) == 0)
714 ++newinfo->stacksize;
715 }
716
717 ret = -EINVAL;
718 if (i != repl->num_entries)
719 goto out_free;
720
721 ret = xt_check_table_hooks(newinfo, repl->valid_hooks);
722 if (ret)
723 goto out_free;
724
725 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) {
726 ret = -ELOOP;
727 goto out_free;
728 }
729 kvfree(offsets);
730
731 /* Finally, each sanity check must pass */
732 i = 0;
733 xt_entry_foreach(iter, entry0, newinfo->size) {
734 ret = find_check_entry(iter, net, repl->name, repl->size,
735 &alloc_state);
736 if (ret != 0)
737 break;
738 ++i;
739 }
740
741 if (ret != 0) {
742 xt_entry_foreach(iter, entry0, newinfo->size) {
743 if (i-- == 0)
744 break;
745 cleanup_entry(iter, net);
746 }
747 return ret;
748 }
749
750 return ret;
751 out_free:
752 kvfree(offsets);
753 return ret;
754 }
755
756 static void
757 get_counters(const struct xt_table_info *t,
758 struct xt_counters counters[])
759 {
760 struct ip6t_entry *iter;
761 unsigned int cpu;
762 unsigned int i;
763
764 for_each_possible_cpu(cpu) {
765 seqcount_t *s = &per_cpu(xt_recseq, cpu);
766
767 i = 0;
768 xt_entry_foreach(iter, t->entries, t->size) {
769 struct xt_counters *tmp;
770 u64 bcnt, pcnt;
771 unsigned int start;
772
773 tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
774 do {
775 start = read_seqcount_begin(s);
776 bcnt = tmp->bcnt;
777 pcnt = tmp->pcnt;
778 } while (read_seqcount_retry(s, start));
779
780 ADD_COUNTER(counters[i], bcnt, pcnt);
781 ++i;
782 cond_resched();
783 }
784 }
785 }
786
787 static void get_old_counters(const struct xt_table_info *t,
788 struct xt_counters counters[])
789 {
790 struct ip6t_entry *iter;
791 unsigned int cpu, i;
792
793 for_each_possible_cpu(cpu) {
794 i = 0;
795 xt_entry_foreach(iter, t->entries, t->size) {
796 const struct xt_counters *tmp;
797
798 tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
799 ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt);
800 ++i;
801 }
802 cond_resched();
803 }
804 }
805
806 static struct xt_counters *alloc_counters(const struct xt_table *table)
807 {
808 unsigned int countersize;
809 struct xt_counters *counters;
810 const struct xt_table_info *private = table->private;
811
812 /* We need atomic snapshot of counters: rest doesn't change
813 (other than comefrom, which userspace doesn't care
814 about). */
815 countersize = sizeof(struct xt_counters) * private->number;
816 counters = vzalloc(countersize);
817
818 if (counters == NULL)
819 return ERR_PTR(-ENOMEM);
820
821 get_counters(private, counters);
822
823 return counters;
824 }
825
826 static int
827 copy_entries_to_user(unsigned int total_size,
828 const struct xt_table *table,
829 void __user *userptr)
830 {
831 unsigned int off, num;
832 const struct ip6t_entry *e;
833 struct xt_counters *counters;
834 const struct xt_table_info *private = table->private;
835 int ret = 0;
836 const void *loc_cpu_entry;
837
838 counters = alloc_counters(table);
839 if (IS_ERR(counters))
840 return PTR_ERR(counters);
841
842 loc_cpu_entry = private->entries;
843
844 /* FIXME: use iterator macros --RR */
845 /* ... then go back and fix counters and names */
846 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
847 unsigned int i;
848 const struct xt_entry_match *m;
849 const struct xt_entry_target *t;
850
851 e = loc_cpu_entry + off;
852 if (copy_to_user(userptr + off, e, sizeof(*e))) {
853 ret = -EFAULT;
854 goto free_counters;
855 }
856 if (copy_to_user(userptr + off
857 + offsetof(struct ip6t_entry, counters),
858 &counters[num],
859 sizeof(counters[num])) != 0) {
860 ret = -EFAULT;
861 goto free_counters;
862 }
863
864 for (i = sizeof(struct ip6t_entry);
865 i < e->target_offset;
866 i += m->u.match_size) {
867 m = (void *)e + i;
868
869 if (xt_match_to_user(m, userptr + off + i)) {
870 ret = -EFAULT;
871 goto free_counters;
872 }
873 }
874
875 t = ip6t_get_target_c(e);
876 if (xt_target_to_user(t, userptr + off + e->target_offset)) {
877 ret = -EFAULT;
878 goto free_counters;
879 }
880 }
881
882 free_counters:
883 vfree(counters);
884 return ret;
885 }
886
887 #ifdef CONFIG_COMPAT
888 static void compat_standard_from_user(void *dst, const void *src)
889 {
890 int v = *(compat_int_t *)src;
891
892 if (v > 0)
893 v += xt_compat_calc_jump(AF_INET6, v);
894 memcpy(dst, &v, sizeof(v));
895 }
896
897 static int compat_standard_to_user(void __user *dst, const void *src)
898 {
899 compat_int_t cv = *(int *)src;
900
901 if (cv > 0)
902 cv -= xt_compat_calc_jump(AF_INET6, cv);
903 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
904 }
905
906 static int compat_calc_entry(const struct ip6t_entry *e,
907 const struct xt_table_info *info,
908 const void *base, struct xt_table_info *newinfo)
909 {
910 const struct xt_entry_match *ematch;
911 const struct xt_entry_target *t;
912 unsigned int entry_offset;
913 int off, i, ret;
914
915 off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
916 entry_offset = (void *)e - base;
917 xt_ematch_foreach(ematch, e)
918 off += xt_compat_match_offset(ematch->u.kernel.match);
919 t = ip6t_get_target_c(e);
920 off += xt_compat_target_offset(t->u.kernel.target);
921 newinfo->size -= off;
922 ret = xt_compat_add_offset(AF_INET6, entry_offset, off);
923 if (ret)
924 return ret;
925
926 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
927 if (info->hook_entry[i] &&
928 (e < (struct ip6t_entry *)(base + info->hook_entry[i])))
929 newinfo->hook_entry[i] -= off;
930 if (info->underflow[i] &&
931 (e < (struct ip6t_entry *)(base + info->underflow[i])))
932 newinfo->underflow[i] -= off;
933 }
934 return 0;
935 }
936
937 static int compat_table_info(const struct xt_table_info *info,
938 struct xt_table_info *newinfo)
939 {
940 struct ip6t_entry *iter;
941 const void *loc_cpu_entry;
942 int ret;
943
944 if (!newinfo || !info)
945 return -EINVAL;
946
947 /* we dont care about newinfo->entries */
948 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
949 newinfo->initial_entries = 0;
950 loc_cpu_entry = info->entries;
951 ret = xt_compat_init_offsets(AF_INET6, info->number);
952 if (ret)
953 return ret;
954 xt_entry_foreach(iter, loc_cpu_entry, info->size) {
955 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
956 if (ret != 0)
957 return ret;
958 }
959 return 0;
960 }
961 #endif
962
963 static int get_info(struct net *net, void __user *user, const int *len)
964 {
965 char name[XT_TABLE_MAXNAMELEN];
966 struct xt_table *t;
967 int ret;
968
969 if (*len != sizeof(struct ip6t_getinfo))
970 return -EINVAL;
971
972 if (copy_from_user(name, user, sizeof(name)) != 0)
973 return -EFAULT;
974
975 name[XT_TABLE_MAXNAMELEN-1] = '\0';
976 #ifdef CONFIG_COMPAT
977 if (in_compat_syscall())
978 xt_compat_lock(AF_INET6);
979 #endif
980 t = xt_request_find_table_lock(net, AF_INET6, name);
981 if (!IS_ERR(t)) {
982 struct ip6t_getinfo info;
983 const struct xt_table_info *private = t->private;
984 #ifdef CONFIG_COMPAT
985 struct xt_table_info tmp;
986
987 if (in_compat_syscall()) {
988 ret = compat_table_info(private, &tmp);
989 xt_compat_flush_offsets(AF_INET6);
990 private = &tmp;
991 }
992 #endif
993 memset(&info, 0, sizeof(info));
994 info.valid_hooks = t->valid_hooks;
995 memcpy(info.hook_entry, private->hook_entry,
996 sizeof(info.hook_entry));
997 memcpy(info.underflow, private->underflow,
998 sizeof(info.underflow));
999 info.num_entries = private->number;
1000 info.size = private->size;
1001 strcpy(info.name, name);
1002
1003 if (copy_to_user(user, &info, *len) != 0)
1004 ret = -EFAULT;
1005 else
1006 ret = 0;
1007
1008 xt_table_unlock(t);
1009 module_put(t->me);
1010 } else
1011 ret = PTR_ERR(t);
1012 #ifdef CONFIG_COMPAT
1013 if (in_compat_syscall())
1014 xt_compat_unlock(AF_INET6);
1015 #endif
1016 return ret;
1017 }
1018
1019 static int
1020 get_entries(struct net *net, struct ip6t_get_entries __user *uptr,
1021 const int *len)
1022 {
1023 int ret;
1024 struct ip6t_get_entries get;
1025 struct xt_table *t;
1026
1027 if (*len < sizeof(get))
1028 return -EINVAL;
1029 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1030 return -EFAULT;
1031 if (*len != sizeof(struct ip6t_get_entries) + get.size)
1032 return -EINVAL;
1033
1034 get.name[sizeof(get.name) - 1] = '\0';
1035
1036 t = xt_find_table_lock(net, AF_INET6, get.name);
1037 if (!IS_ERR(t)) {
1038 struct xt_table_info *private = t->private;
1039 if (get.size == private->size)
1040 ret = copy_entries_to_user(private->size,
1041 t, uptr->entrytable);
1042 else
1043 ret = -EAGAIN;
1044
1045 module_put(t->me);
1046 xt_table_unlock(t);
1047 } else
1048 ret = PTR_ERR(t);
1049
1050 return ret;
1051 }
1052
1053 static int
1054 __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
1055 struct xt_table_info *newinfo, unsigned int num_counters,
1056 void __user *counters_ptr)
1057 {
1058 int ret;
1059 struct xt_table *t;
1060 struct xt_table_info *oldinfo;
1061 struct xt_counters *counters;
1062 struct ip6t_entry *iter;
1063
1064 ret = 0;
1065 counters = xt_counters_alloc(num_counters);
1066 if (!counters) {
1067 ret = -ENOMEM;
1068 goto out;
1069 }
1070
1071 t = xt_request_find_table_lock(net, AF_INET6, name);
1072 if (IS_ERR(t)) {
1073 ret = PTR_ERR(t);
1074 goto free_newinfo_counters_untrans;
1075 }
1076
1077 /* You lied! */
1078 if (valid_hooks != t->valid_hooks) {
1079 ret = -EINVAL;
1080 goto put_module;
1081 }
1082
1083 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1084 if (!oldinfo)
1085 goto put_module;
1086
1087 /* Update module usage count based on number of rules */
1088 if ((oldinfo->number > oldinfo->initial_entries) ||
1089 (newinfo->number <= oldinfo->initial_entries))
1090 module_put(t->me);
1091 if ((oldinfo->number > oldinfo->initial_entries) &&
1092 (newinfo->number <= oldinfo->initial_entries))
1093 module_put(t->me);
1094
1095 xt_table_unlock(t);
1096
1097 get_old_counters(oldinfo, counters);
1098
1099 /* Decrease module usage counts and free resource */
1100 xt_entry_foreach(iter, oldinfo->entries, oldinfo->size)
1101 cleanup_entry(iter, net);
1102
1103 xt_free_table_info(oldinfo);
1104 if (copy_to_user(counters_ptr, counters,
1105 sizeof(struct xt_counters) * num_counters) != 0) {
1106 /* Silent error, can't fail, new table is already in place */
1107 net_warn_ratelimited("ip6tables: counters copy to user failed while replacing table\n");
1108 }
1109 vfree(counters);
1110 return ret;
1111
1112 put_module:
1113 module_put(t->me);
1114 xt_table_unlock(t);
1115 free_newinfo_counters_untrans:
1116 vfree(counters);
1117 out:
1118 return ret;
1119 }
1120
1121 static int
1122 do_replace(struct net *net, sockptr_t arg, unsigned int len)
1123 {
1124 int ret;
1125 struct ip6t_replace tmp;
1126 struct xt_table_info *newinfo;
1127 void *loc_cpu_entry;
1128 struct ip6t_entry *iter;
1129
1130 if (copy_from_sockptr(&tmp, arg, 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
1139 tmp.name[sizeof(tmp.name)-1] = 0;
1140
1141 newinfo = xt_alloc_table_info(tmp.size);
1142 if (!newinfo)
1143 return -ENOMEM;
1144
1145 loc_cpu_entry = newinfo->entries;
1146 if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp),
1147 tmp.size) != 0) {
1148 ret = -EFAULT;
1149 goto free_newinfo;
1150 }
1151
1152 ret = translate_table(net, newinfo, loc_cpu_entry, &tmp);
1153 if (ret != 0)
1154 goto free_newinfo;
1155
1156 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1157 tmp.num_counters, tmp.counters);
1158 if (ret)
1159 goto free_newinfo_untrans;
1160 return 0;
1161
1162 free_newinfo_untrans:
1163 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1164 cleanup_entry(iter, net);
1165 free_newinfo:
1166 xt_free_table_info(newinfo);
1167 return ret;
1168 }
1169
1170 static int
1171 do_add_counters(struct net *net, sockptr_t arg, unsigned int len)
1172 {
1173 unsigned int i;
1174 struct xt_counters_info tmp;
1175 struct xt_counters *paddc;
1176 struct xt_table *t;
1177 const struct xt_table_info *private;
1178 int ret = 0;
1179 struct ip6t_entry *iter;
1180 unsigned int addend;
1181
1182 paddc = xt_copy_counters(arg, len, &tmp);
1183 if (IS_ERR(paddc))
1184 return PTR_ERR(paddc);
1185 t = xt_find_table_lock(net, AF_INET6, tmp.name);
1186 if (IS_ERR(t)) {
1187 ret = PTR_ERR(t);
1188 goto free;
1189 }
1190
1191 local_bh_disable();
1192 private = t->private;
1193 if (private->number != tmp.num_counters) {
1194 ret = -EINVAL;
1195 goto unlock_up_free;
1196 }
1197
1198 i = 0;
1199 addend = xt_write_recseq_begin();
1200 xt_entry_foreach(iter, private->entries, private->size) {
1201 struct xt_counters *tmp;
1202
1203 tmp = xt_get_this_cpu_counter(&iter->counters);
1204 ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt);
1205 ++i;
1206 }
1207 xt_write_recseq_end(addend);
1208 unlock_up_free:
1209 local_bh_enable();
1210 xt_table_unlock(t);
1211 module_put(t->me);
1212 free:
1213 vfree(paddc);
1214
1215 return ret;
1216 }
1217
1218 #ifdef CONFIG_COMPAT
1219 struct compat_ip6t_replace {
1220 char name[XT_TABLE_MAXNAMELEN];
1221 u32 valid_hooks;
1222 u32 num_entries;
1223 u32 size;
1224 u32 hook_entry[NF_INET_NUMHOOKS];
1225 u32 underflow[NF_INET_NUMHOOKS];
1226 u32 num_counters;
1227 compat_uptr_t counters; /* struct xt_counters * */
1228 struct compat_ip6t_entry entries[];
1229 };
1230
1231 static int
1232 compat_copy_entry_to_user(struct ip6t_entry *e, void __user **dstptr,
1233 unsigned int *size, struct xt_counters *counters,
1234 unsigned int i)
1235 {
1236 struct xt_entry_target *t;
1237 struct compat_ip6t_entry __user *ce;
1238 u_int16_t target_offset, next_offset;
1239 compat_uint_t origsize;
1240 const struct xt_entry_match *ematch;
1241 int ret = 0;
1242
1243 origsize = *size;
1244 ce = *dstptr;
1245 if (copy_to_user(ce, e, sizeof(struct ip6t_entry)) != 0 ||
1246 copy_to_user(&ce->counters, &counters[i],
1247 sizeof(counters[i])) != 0)
1248 return -EFAULT;
1249
1250 *dstptr += sizeof(struct compat_ip6t_entry);
1251 *size -= sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1252
1253 xt_ematch_foreach(ematch, e) {
1254 ret = xt_compat_match_to_user(ematch, dstptr, size);
1255 if (ret != 0)
1256 return ret;
1257 }
1258 target_offset = e->target_offset - (origsize - *size);
1259 t = ip6t_get_target(e);
1260 ret = xt_compat_target_to_user(t, dstptr, size);
1261 if (ret)
1262 return ret;
1263 next_offset = e->next_offset - (origsize - *size);
1264 if (put_user(target_offset, &ce->target_offset) != 0 ||
1265 put_user(next_offset, &ce->next_offset) != 0)
1266 return -EFAULT;
1267 return 0;
1268 }
1269
1270 static int
1271 compat_find_calc_match(struct xt_entry_match *m,
1272 const struct ip6t_ip6 *ipv6,
1273 int *size)
1274 {
1275 struct xt_match *match;
1276
1277 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name,
1278 m->u.user.revision);
1279 if (IS_ERR(match))
1280 return PTR_ERR(match);
1281
1282 m->u.kernel.match = match;
1283 *size += xt_compat_match_offset(match);
1284 return 0;
1285 }
1286
1287 static void compat_release_entry(struct compat_ip6t_entry *e)
1288 {
1289 struct xt_entry_target *t;
1290 struct xt_entry_match *ematch;
1291
1292 /* Cleanup all matches */
1293 xt_ematch_foreach(ematch, e)
1294 module_put(ematch->u.kernel.match->me);
1295 t = compat_ip6t_get_target(e);
1296 module_put(t->u.kernel.target->me);
1297 }
1298
1299 static int
1300 check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e,
1301 struct xt_table_info *newinfo,
1302 unsigned int *size,
1303 const unsigned char *base,
1304 const unsigned char *limit)
1305 {
1306 struct xt_entry_match *ematch;
1307 struct xt_entry_target *t;
1308 struct xt_target *target;
1309 unsigned int entry_offset;
1310 unsigned int j;
1311 int ret, off;
1312
1313 if ((unsigned long)e % __alignof__(struct compat_ip6t_entry) != 0 ||
1314 (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit ||
1315 (unsigned char *)e + e->next_offset > limit)
1316 return -EINVAL;
1317
1318 if (e->next_offset < sizeof(struct compat_ip6t_entry) +
1319 sizeof(struct compat_xt_entry_target))
1320 return -EINVAL;
1321
1322 if (!ip6_checkentry(&e->ipv6))
1323 return -EINVAL;
1324
1325 ret = xt_compat_check_entry_offsets(e, e->elems,
1326 e->target_offset, e->next_offset);
1327 if (ret)
1328 return ret;
1329
1330 off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1331 entry_offset = (void *)e - (void *)base;
1332 j = 0;
1333 xt_ematch_foreach(ematch, e) {
1334 ret = compat_find_calc_match(ematch, &e->ipv6, &off);
1335 if (ret != 0)
1336 goto release_matches;
1337 ++j;
1338 }
1339
1340 t = compat_ip6t_get_target(e);
1341 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name,
1342 t->u.user.revision);
1343 if (IS_ERR(target)) {
1344 ret = PTR_ERR(target);
1345 goto release_matches;
1346 }
1347 t->u.kernel.target = target;
1348
1349 off += xt_compat_target_offset(target);
1350 *size += off;
1351 ret = xt_compat_add_offset(AF_INET6, entry_offset, off);
1352 if (ret)
1353 goto out;
1354
1355 return 0;
1356
1357 out:
1358 module_put(t->u.kernel.target->me);
1359 release_matches:
1360 xt_ematch_foreach(ematch, e) {
1361 if (j-- == 0)
1362 break;
1363 module_put(ematch->u.kernel.match->me);
1364 }
1365 return ret;
1366 }
1367
1368 static void
1369 compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr,
1370 unsigned int *size,
1371 struct xt_table_info *newinfo, unsigned char *base)
1372 {
1373 struct xt_entry_target *t;
1374 struct ip6t_entry *de;
1375 unsigned int origsize;
1376 int h;
1377 struct xt_entry_match *ematch;
1378
1379 origsize = *size;
1380 de = *dstptr;
1381 memcpy(de, e, sizeof(struct ip6t_entry));
1382 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1383
1384 *dstptr += sizeof(struct ip6t_entry);
1385 *size += sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
1386
1387 xt_ematch_foreach(ematch, e)
1388 xt_compat_match_from_user(ematch, dstptr, size);
1389
1390 de->target_offset = e->target_offset - (origsize - *size);
1391 t = compat_ip6t_get_target(e);
1392 xt_compat_target_from_user(t, dstptr, size);
1393
1394 de->next_offset = e->next_offset - (origsize - *size);
1395 for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1396 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1397 newinfo->hook_entry[h] -= origsize - *size;
1398 if ((unsigned char *)de - base < newinfo->underflow[h])
1399 newinfo->underflow[h] -= origsize - *size;
1400 }
1401 }
1402
1403 static int
1404 translate_compat_table(struct net *net,
1405 struct xt_table_info **pinfo,
1406 void **pentry0,
1407 const struct compat_ip6t_replace *compatr)
1408 {
1409 unsigned int i, j;
1410 struct xt_table_info *newinfo, *info;
1411 void *pos, *entry0, *entry1;
1412 struct compat_ip6t_entry *iter0;
1413 struct ip6t_replace repl;
1414 unsigned int size;
1415 int ret;
1416
1417 info = *pinfo;
1418 entry0 = *pentry0;
1419 size = compatr->size;
1420 info->number = compatr->num_entries;
1421
1422 j = 0;
1423 xt_compat_lock(AF_INET6);
1424 ret = xt_compat_init_offsets(AF_INET6, compatr->num_entries);
1425 if (ret)
1426 goto out_unlock;
1427 /* Walk through entries, checking offsets. */
1428 xt_entry_foreach(iter0, entry0, compatr->size) {
1429 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1430 entry0,
1431 entry0 + compatr->size);
1432 if (ret != 0)
1433 goto out_unlock;
1434 ++j;
1435 }
1436
1437 ret = -EINVAL;
1438 if (j != compatr->num_entries)
1439 goto out_unlock;
1440
1441 ret = -ENOMEM;
1442 newinfo = xt_alloc_table_info(size);
1443 if (!newinfo)
1444 goto out_unlock;
1445
1446 memset(newinfo->entries, 0, size);
1447
1448 newinfo->number = compatr->num_entries;
1449 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1450 newinfo->hook_entry[i] = compatr->hook_entry[i];
1451 newinfo->underflow[i] = compatr->underflow[i];
1452 }
1453 entry1 = newinfo->entries;
1454 pos = entry1;
1455 size = compatr->size;
1456 xt_entry_foreach(iter0, entry0, compatr->size)
1457 compat_copy_entry_from_user(iter0, &pos, &size,
1458 newinfo, entry1);
1459
1460 /* all module references in entry0 are now gone. */
1461 xt_compat_flush_offsets(AF_INET6);
1462 xt_compat_unlock(AF_INET6);
1463
1464 memcpy(&repl, compatr, sizeof(*compatr));
1465
1466 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1467 repl.hook_entry[i] = newinfo->hook_entry[i];
1468 repl.underflow[i] = newinfo->underflow[i];
1469 }
1470
1471 repl.num_counters = 0;
1472 repl.counters = NULL;
1473 repl.size = newinfo->size;
1474 ret = translate_table(net, newinfo, entry1, &repl);
1475 if (ret)
1476 goto free_newinfo;
1477
1478 *pinfo = newinfo;
1479 *pentry0 = entry1;
1480 xt_free_table_info(info);
1481 return 0;
1482
1483 free_newinfo:
1484 xt_free_table_info(newinfo);
1485 return ret;
1486 out_unlock:
1487 xt_compat_flush_offsets(AF_INET6);
1488 xt_compat_unlock(AF_INET6);
1489 xt_entry_foreach(iter0, entry0, compatr->size) {
1490 if (j-- == 0)
1491 break;
1492 compat_release_entry(iter0);
1493 }
1494 return ret;
1495 }
1496
1497 static int
1498 compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
1499 {
1500 int ret;
1501 struct compat_ip6t_replace tmp;
1502 struct xt_table_info *newinfo;
1503 void *loc_cpu_entry;
1504 struct ip6t_entry *iter;
1505
1506 if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0)
1507 return -EFAULT;
1508
1509 /* overflow check */
1510 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1511 return -ENOMEM;
1512 if (tmp.num_counters == 0)
1513 return -EINVAL;
1514
1515 tmp.name[sizeof(tmp.name)-1] = 0;
1516
1517 newinfo = xt_alloc_table_info(tmp.size);
1518 if (!newinfo)
1519 return -ENOMEM;
1520
1521 loc_cpu_entry = newinfo->entries;
1522 if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp),
1523 tmp.size) != 0) {
1524 ret = -EFAULT;
1525 goto free_newinfo;
1526 }
1527
1528 ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp);
1529 if (ret != 0)
1530 goto free_newinfo;
1531
1532 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1533 tmp.num_counters, compat_ptr(tmp.counters));
1534 if (ret)
1535 goto free_newinfo_untrans;
1536 return 0;
1537
1538 free_newinfo_untrans:
1539 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1540 cleanup_entry(iter, net);
1541 free_newinfo:
1542 xt_free_table_info(newinfo);
1543 return ret;
1544 }
1545
1546 struct compat_ip6t_get_entries {
1547 char name[XT_TABLE_MAXNAMELEN];
1548 compat_uint_t size;
1549 struct compat_ip6t_entry entrytable[];
1550 };
1551
1552 static int
1553 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
1554 void __user *userptr)
1555 {
1556 struct xt_counters *counters;
1557 const struct xt_table_info *private = table->private;
1558 void __user *pos;
1559 unsigned int size;
1560 int ret = 0;
1561 unsigned int i = 0;
1562 struct ip6t_entry *iter;
1563
1564 counters = alloc_counters(table);
1565 if (IS_ERR(counters))
1566 return PTR_ERR(counters);
1567
1568 pos = userptr;
1569 size = total_size;
1570 xt_entry_foreach(iter, private->entries, total_size) {
1571 ret = compat_copy_entry_to_user(iter, &pos,
1572 &size, counters, i++);
1573 if (ret != 0)
1574 break;
1575 }
1576
1577 vfree(counters);
1578 return ret;
1579 }
1580
1581 static int
1582 compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr,
1583 int *len)
1584 {
1585 int ret;
1586 struct compat_ip6t_get_entries get;
1587 struct xt_table *t;
1588
1589 if (*len < sizeof(get))
1590 return -EINVAL;
1591
1592 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1593 return -EFAULT;
1594
1595 if (*len != sizeof(struct compat_ip6t_get_entries) + get.size)
1596 return -EINVAL;
1597
1598 get.name[sizeof(get.name) - 1] = '\0';
1599
1600 xt_compat_lock(AF_INET6);
1601 t = xt_find_table_lock(net, AF_INET6, get.name);
1602 if (!IS_ERR(t)) {
1603 const struct xt_table_info *private = t->private;
1604 struct xt_table_info info;
1605 ret = compat_table_info(private, &info);
1606 if (!ret && get.size == info.size)
1607 ret = compat_copy_entries_to_user(private->size,
1608 t, uptr->entrytable);
1609 else if (!ret)
1610 ret = -EAGAIN;
1611
1612 xt_compat_flush_offsets(AF_INET6);
1613 module_put(t->me);
1614 xt_table_unlock(t);
1615 } else
1616 ret = PTR_ERR(t);
1617
1618 xt_compat_unlock(AF_INET6);
1619 return ret;
1620 }
1621 #endif
1622
1623 static int
1624 do_ip6t_set_ctl(struct sock *sk, int cmd, sockptr_t arg, unsigned int len)
1625 {
1626 int ret;
1627
1628 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1629 return -EPERM;
1630
1631 switch (cmd) {
1632 case IP6T_SO_SET_REPLACE:
1633 #ifdef CONFIG_COMPAT
1634 if (in_compat_syscall())
1635 ret = compat_do_replace(sock_net(sk), arg, len);
1636 else
1637 #endif
1638 ret = do_replace(sock_net(sk), arg, len);
1639 break;
1640
1641 case IP6T_SO_SET_ADD_COUNTERS:
1642 ret = do_add_counters(sock_net(sk), arg, len);
1643 break;
1644
1645 default:
1646 ret = -EINVAL;
1647 }
1648
1649 return ret;
1650 }
1651
1652 static int
1653 do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1654 {
1655 int ret;
1656
1657 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1658 return -EPERM;
1659
1660 switch (cmd) {
1661 case IP6T_SO_GET_INFO:
1662 ret = get_info(sock_net(sk), user, len);
1663 break;
1664
1665 case IP6T_SO_GET_ENTRIES:
1666 #ifdef CONFIG_COMPAT
1667 if (in_compat_syscall())
1668 ret = compat_get_entries(sock_net(sk), user, len);
1669 else
1670 #endif
1671 ret = get_entries(sock_net(sk), user, len);
1672 break;
1673
1674 case IP6T_SO_GET_REVISION_MATCH:
1675 case IP6T_SO_GET_REVISION_TARGET: {
1676 struct xt_get_revision rev;
1677 int target;
1678
1679 if (*len != sizeof(rev)) {
1680 ret = -EINVAL;
1681 break;
1682 }
1683 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1684 ret = -EFAULT;
1685 break;
1686 }
1687 rev.name[sizeof(rev.name)-1] = 0;
1688
1689 if (cmd == IP6T_SO_GET_REVISION_TARGET)
1690 target = 1;
1691 else
1692 target = 0;
1693
1694 try_then_request_module(xt_find_revision(AF_INET6, rev.name,
1695 rev.revision,
1696 target, &ret),
1697 "ip6t_%s", rev.name);
1698 break;
1699 }
1700
1701 default:
1702 ret = -EINVAL;
1703 }
1704
1705 return ret;
1706 }
1707
1708 static void __ip6t_unregister_table(struct net *net, struct xt_table *table)
1709 {
1710 struct xt_table_info *private;
1711 void *loc_cpu_entry;
1712 struct module *table_owner = table->me;
1713 struct ip6t_entry *iter;
1714
1715 private = xt_unregister_table(table);
1716
1717 /* Decrease module usage counts and free resources */
1718 loc_cpu_entry = private->entries;
1719 xt_entry_foreach(iter, loc_cpu_entry, private->size)
1720 cleanup_entry(iter, net);
1721 if (private->number > private->initial_entries)
1722 module_put(table_owner);
1723 xt_free_table_info(private);
1724 }
1725
1726 int ip6t_register_table(struct net *net, const struct xt_table *table,
1727 const struct ip6t_replace *repl,
1728 const struct nf_hook_ops *ops,
1729 struct xt_table **res)
1730 {
1731 int ret;
1732 struct xt_table_info *newinfo;
1733 struct xt_table_info bootstrap = {0};
1734 void *loc_cpu_entry;
1735 struct xt_table *new_table;
1736
1737 newinfo = xt_alloc_table_info(repl->size);
1738 if (!newinfo)
1739 return -ENOMEM;
1740
1741 loc_cpu_entry = newinfo->entries;
1742 memcpy(loc_cpu_entry, repl->entries, repl->size);
1743
1744 ret = translate_table(net, newinfo, loc_cpu_entry, repl);
1745 if (ret != 0)
1746 goto out_free;
1747
1748 new_table = xt_register_table(net, table, &bootstrap, newinfo);
1749 if (IS_ERR(new_table)) {
1750 ret = PTR_ERR(new_table);
1751 goto out_free;
1752 }
1753
1754 /* set res now, will see skbs right after nf_register_net_hooks */
1755 WRITE_ONCE(*res, new_table);
1756 if (!ops)
1757 return 0;
1758
1759 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
1760 if (ret != 0) {
1761 __ip6t_unregister_table(net, new_table);
1762 *res = NULL;
1763 }
1764
1765 return ret;
1766
1767 out_free:
1768 xt_free_table_info(newinfo);
1769 return ret;
1770 }
1771
1772 void ip6t_unregister_table_pre_exit(struct net *net, struct xt_table *table,
1773 const struct nf_hook_ops *ops)
1774 {
1775 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
1776 }
1777
1778 void ip6t_unregister_table_exit(struct net *net, struct xt_table *table)
1779 {
1780 __ip6t_unregister_table(net, table);
1781 }
1782
1783 void ip6t_unregister_table(struct net *net, struct xt_table *table,
1784 const struct nf_hook_ops *ops)
1785 {
1786 if (ops)
1787 ip6t_unregister_table_pre_exit(net, table, ops);
1788 __ip6t_unregister_table(net, table);
1789 }
1790
1791 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
1792 static inline bool
1793 icmp6_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
1794 u_int8_t type, u_int8_t code,
1795 bool invert)
1796 {
1797 return (type == test_type && code >= min_code && code <= max_code)
1798 ^ invert;
1799 }
1800
1801 static bool
1802 icmp6_match(const struct sk_buff *skb, struct xt_action_param *par)
1803 {
1804 const struct icmp6hdr *ic;
1805 struct icmp6hdr _icmph;
1806 const struct ip6t_icmp *icmpinfo = par->matchinfo;
1807
1808 /* Must not be a fragment. */
1809 if (par->fragoff != 0)
1810 return false;
1811
1812 ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph);
1813 if (ic == NULL) {
1814 /* We've been asked to examine this packet, and we
1815 * can't. Hence, no choice but to drop.
1816 */
1817 par->hotdrop = true;
1818 return false;
1819 }
1820
1821 return icmp6_type_code_match(icmpinfo->type,
1822 icmpinfo->code[0],
1823 icmpinfo->code[1],
1824 ic->icmp6_type, ic->icmp6_code,
1825 !!(icmpinfo->invflags&IP6T_ICMP_INV));
1826 }
1827
1828 /* Called when user tries to insert an entry of this type. */
1829 static int icmp6_checkentry(const struct xt_mtchk_param *par)
1830 {
1831 const struct ip6t_icmp *icmpinfo = par->matchinfo;
1832
1833 /* Must specify no unknown invflags */
1834 return (icmpinfo->invflags & ~IP6T_ICMP_INV) ? -EINVAL : 0;
1835 }
1836
1837 /* The built-in targets: standard (NULL) and error. */
1838 static struct xt_target ip6t_builtin_tg[] __read_mostly = {
1839 {
1840 .name = XT_STANDARD_TARGET,
1841 .targetsize = sizeof(int),
1842 .family = NFPROTO_IPV6,
1843 #ifdef CONFIG_COMPAT
1844 .compatsize = sizeof(compat_int_t),
1845 .compat_from_user = compat_standard_from_user,
1846 .compat_to_user = compat_standard_to_user,
1847 #endif
1848 },
1849 {
1850 .name = XT_ERROR_TARGET,
1851 .target = ip6t_error,
1852 .targetsize = XT_FUNCTION_MAXNAMELEN,
1853 .family = NFPROTO_IPV6,
1854 },
1855 };
1856
1857 static struct nf_sockopt_ops ip6t_sockopts = {
1858 .pf = PF_INET6,
1859 .set_optmin = IP6T_BASE_CTL,
1860 .set_optmax = IP6T_SO_SET_MAX+1,
1861 .set = do_ip6t_set_ctl,
1862 .get_optmin = IP6T_BASE_CTL,
1863 .get_optmax = IP6T_SO_GET_MAX+1,
1864 .get = do_ip6t_get_ctl,
1865 .owner = THIS_MODULE,
1866 };
1867
1868 static struct xt_match ip6t_builtin_mt[] __read_mostly = {
1869 {
1870 .name = "icmp6",
1871 .match = icmp6_match,
1872 .matchsize = sizeof(struct ip6t_icmp),
1873 .checkentry = icmp6_checkentry,
1874 .proto = IPPROTO_ICMPV6,
1875 .family = NFPROTO_IPV6,
1876 .me = THIS_MODULE,
1877 },
1878 };
1879
1880 static int __net_init ip6_tables_net_init(struct net *net)
1881 {
1882 return xt_proto_init(net, NFPROTO_IPV6);
1883 }
1884
1885 static void __net_exit ip6_tables_net_exit(struct net *net)
1886 {
1887 xt_proto_fini(net, NFPROTO_IPV6);
1888 }
1889
1890 static struct pernet_operations ip6_tables_net_ops = {
1891 .init = ip6_tables_net_init,
1892 .exit = ip6_tables_net_exit,
1893 };
1894
1895 static int __init ip6_tables_init(void)
1896 {
1897 int ret;
1898
1899 ret = register_pernet_subsys(&ip6_tables_net_ops);
1900 if (ret < 0)
1901 goto err1;
1902
1903 /* No one else will be downing sem now, so we won't sleep */
1904 ret = xt_register_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
1905 if (ret < 0)
1906 goto err2;
1907 ret = xt_register_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt));
1908 if (ret < 0)
1909 goto err4;
1910
1911 /* Register setsockopt */
1912 ret = nf_register_sockopt(&ip6t_sockopts);
1913 if (ret < 0)
1914 goto err5;
1915
1916 return 0;
1917
1918 err5:
1919 xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt));
1920 err4:
1921 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
1922 err2:
1923 unregister_pernet_subsys(&ip6_tables_net_ops);
1924 err1:
1925 return ret;
1926 }
1927
1928 static void __exit ip6_tables_fini(void)
1929 {
1930 nf_unregister_sockopt(&ip6t_sockopts);
1931
1932 xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt));
1933 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
1934 unregister_pernet_subsys(&ip6_tables_net_ops);
1935 }
1936
1937 EXPORT_SYMBOL(ip6t_register_table);
1938 EXPORT_SYMBOL(ip6t_unregister_table);
1939 EXPORT_SYMBOL(ip6t_unregister_table_pre_exit);
1940 EXPORT_SYMBOL(ip6t_unregister_table_exit);
1941 EXPORT_SYMBOL(ip6t_do_table);
1942
1943 module_init(ip6_tables_init);
1944 module_exit(ip6_tables_fini);
1945
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