1/*
2 * Packet matching code.
3 *
4 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
5 * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
6 * Copyright (C) 2006-2010 Patrick McHardy <kaber@trash.net>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13#include <linux/cache.h>
14#include <linux/capability.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/icmp.h>
21#include <net/ip.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/x_tables.h>
30#include <linux/netfilter_ipv4/ip_tables.h>
31#include <net/netfilter/nf_log.h>
32#include "../../netfilter/xt_repldata.h"
33
34MODULE_LICENSE("GPL");
35MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
36MODULE_DESCRIPTION("IPv4 packet filter");
37MODULE_ALIAS("ipt_icmp");
38
39void *ipt_alloc_initial_table(const struct xt_table *info)
40{
41 return xt_alloc_initial_table(ipt, IPT);
42}
43EXPORT_SYMBOL_GPL(ipt_alloc_initial_table);
44
45/* Returns whether matches rule or not. */
46/* Performance critical - called for every packet */
47static inline bool
48ip_packet_match(const struct iphdr *ip,
49 const char *indev,
50 const char *outdev,
51 const struct ipt_ip *ipinfo,
52 int isfrag)
53{
54 unsigned long ret;
55
56 if (NF_INVF(ipinfo, IPT_INV_SRCIP,
57 (ip->saddr & ipinfo->smsk.s_addr) != ipinfo->src.s_addr) ||
58 NF_INVF(ipinfo, IPT_INV_DSTIP,
59 (ip->daddr & ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr))
60 return false;
61
62 ret = ifname_compare_aligned(indev, ipinfo->iniface, ipinfo->iniface_mask);
63
64 if (NF_INVF(ipinfo, IPT_INV_VIA_IN, ret != 0))
65 return false;
66
67 ret = ifname_compare_aligned(outdev, ipinfo->outiface, ipinfo->outiface_mask);
68
69 if (NF_INVF(ipinfo, IPT_INV_VIA_OUT, ret != 0))
70 return false;
71
72 /* Check specific protocol */
73 if (ipinfo->proto &&
74 NF_INVF(ipinfo, IPT_INV_PROTO, ip->protocol != ipinfo->proto))
75 return false;
76
77 /* If we have a fragment rule but the packet is not a fragment
78 * then we return zero */
79 if (NF_INVF(ipinfo, IPT_INV_FRAG,
80 (ipinfo->flags & IPT_F_FRAG) && !isfrag))
81 return false;
82
83 return true;
84}
85
86static bool
87ip_checkentry(const struct ipt_ip *ip)
88{
89 if (ip->flags & ~IPT_F_MASK)
90 return false;
91 if (ip->invflags & ~IPT_INV_MASK)
92 return false;
93 return true;
94}
95
96static unsigned int
97ipt_error(struct sk_buff *skb, const struct xt_action_param *par)
98{
99 net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo);
100
101 return NF_DROP;
102}
103
104/* Performance critical */
105static inline struct ipt_entry *
106get_entry(const void *base, unsigned int offset)
107{
108 return (struct ipt_entry *)(base + offset);
109}
110
111/* All zeroes == unconditional rule. */
112/* Mildly perf critical (only if packet tracing is on) */
113static inline bool unconditional(const struct ipt_entry *e)
114{
115 static const struct ipt_ip uncond;
116
117 return e->target_offset == sizeof(struct ipt_entry) &&
118 memcmp(&e->ip, &uncond, sizeof(uncond)) == 0;
119}
120
121/* for const-correctness */
122static inline const struct xt_entry_target *
123ipt_get_target_c(const struct ipt_entry *e)
124{
125 return ipt_get_target((struct ipt_entry *)e);
126}
127
128#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
129static const char *const hooknames[] = {
130 [NF_INET_PRE_ROUTING] = "PREROUTING",
131 [NF_INET_LOCAL_IN] = "INPUT",
132 [NF_INET_FORWARD] = "FORWARD",
133 [NF_INET_LOCAL_OUT] = "OUTPUT",
134 [NF_INET_POST_ROUTING] = "POSTROUTING",
135};
136
137enum nf_ip_trace_comments {
138 NF_IP_TRACE_COMMENT_RULE,
139 NF_IP_TRACE_COMMENT_RETURN,
140 NF_IP_TRACE_COMMENT_POLICY,
141};
142
143static const char *const comments[] = {
144 [NF_IP_TRACE_COMMENT_RULE] = "rule",
145 [NF_IP_TRACE_COMMENT_RETURN] = "return",
146 [NF_IP_TRACE_COMMENT_POLICY] = "policy",
147};
148
149static const struct nf_loginfo trace_loginfo = {
150 .type = NF_LOG_TYPE_LOG,
151 .u = {
152 .log = {
153 .level = 4,
154 .logflags = NF_LOG_DEFAULT_MASK,
155 },
156 },
157};
158
159/* Mildly perf critical (only if packet tracing is on) */
160static inline int
161get_chainname_rulenum(const struct ipt_entry *s, const struct ipt_entry *e,
162 const char *hookname, const char **chainname,
163 const char **comment, unsigned int *rulenum)
164{
165 const struct xt_standard_target *t = (void *)ipt_get_target_c(s);
166
167 if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) {
168 /* Head of user chain: ERROR target with chainname */
169 *chainname = t->target.data;
170 (*rulenum) = 0;
171 } else if (s == e) {
172 (*rulenum)++;
173
174 if (unconditional(s) &&
175 strcmp(t->target.u.kernel.target->name,
176 XT_STANDARD_TARGET) == 0 &&
177 t->verdict < 0) {
178 /* Tail of chains: STANDARD target (return/policy) */
179 *comment = *chainname == hookname
180 ? comments[NF_IP_TRACE_COMMENT_POLICY]
181 : comments[NF_IP_TRACE_COMMENT_RETURN];
182 }
183 return 1;
184 } else
185 (*rulenum)++;
186
187 return 0;
188}
189
190static void trace_packet(struct net *net,
191 const struct sk_buff *skb,
192 unsigned int hook,
193 const struct net_device *in,
194 const struct net_device *out,
195 const char *tablename,
196 const struct xt_table_info *private,
197 const struct ipt_entry *e)
198{
199 const struct ipt_entry *root;
200 const char *hookname, *chainname, *comment;
201 const struct ipt_entry *iter;
202 unsigned int rulenum = 0;
203
204 root = get_entry(private->entries, private->hook_entry[hook]);
205
206 hookname = chainname = hooknames[hook];
207 comment = comments[NF_IP_TRACE_COMMENT_RULE];
208
209 xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
210 if (get_chainname_rulenum(iter, e, hookname,
211 &chainname, &comment, &rulenum) != 0)
212 break;
213
214 nf_log_trace(net, AF_INET, hook, skb, in, out, &trace_loginfo,
215 "TRACE: %s:%s:%s:%u ",
216 tablename, chainname, comment, rulenum);
217}
218#endif
219
220static inline
221struct ipt_entry *ipt_next_entry(const struct ipt_entry *entry)
222{
223 return (void *)entry + entry->next_offset;
224}
225
226/* Returns one of the generic firewall policies, like NF_ACCEPT. */
227unsigned int
228ipt_do_table(struct sk_buff *skb,
229 const struct nf_hook_state *state,
230 struct xt_table *table)
231{
232 unsigned int hook = state->hook;
233 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
234 const struct iphdr *ip;
235 /* Initializing verdict to NF_DROP keeps gcc happy. */
236 unsigned int verdict = NF_DROP;
237 const char *indev, *outdev;
238 const void *table_base;
239 struct ipt_entry *e, **jumpstack;
240 unsigned int stackidx, cpu;
241 const struct xt_table_info *private;
242 struct xt_action_param acpar;
243 unsigned int addend;
244
245 /* Initialization */
246 stackidx = 0;
247 ip = ip_hdr(skb);
248 indev = state->in ? state->in->name : nulldevname;
249 outdev = state->out ? state->out->name : nulldevname;
250 /* We handle fragments by dealing with the first fragment as
251 * if it was a normal packet. All other fragments are treated
252 * normally, except that they will NEVER match rules that ask
253 * things we don't know, ie. tcp syn flag or ports). If the
254 * rule is also a fragment-specific rule, non-fragments won't
255 * match it. */
256 acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
257 acpar.thoff = ip_hdrlen(skb);
258 acpar.hotdrop = false;
259 acpar.state = state;
260
261 WARN_ON(!(table->valid_hooks & (1 << hook)));
262 local_bh_disable();
263 addend = xt_write_recseq_begin();
264 private = READ_ONCE(table->private); /* Address dependency. */
265 cpu = smp_processor_id();
266 table_base = private->entries;
267 jumpstack = (struct ipt_entry **)private->jumpstack[cpu];
268
269 /* Switch to alternate jumpstack if we're being invoked via TEE.
270 * TEE issues XT_CONTINUE verdict on original skb so we must not
271 * clobber the jumpstack.
272 *
273 * For recursion via REJECT or SYNPROXY the stack will be clobbered
274 * but it is no problem since absolute verdict is issued by these.
275 */
276 if (static_key_false(&xt_tee_enabled))
277 jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
278
279 e = get_entry(table_base, private->hook_entry[hook]);
280
281 do {
282 const struct xt_entry_target *t;
283 const struct xt_entry_match *ematch;
284 struct xt_counters *counter;
285
286 WARN_ON(!e);
287 if (!ip_packet_match(ip, indev, outdev,
288 &e->ip, acpar.fragoff)) {
289 no_match:
290 e = ipt_next_entry(e);
291 continue;
292 }
293
294 xt_ematch_foreach(ematch, e) {
295 acpar.match = ematch->u.kernel.match;
296 acpar.matchinfo = ematch->data;
297 if (!acpar.match->match(skb, &acpar))
298 goto no_match;
299 }
300
301 counter = xt_get_this_cpu_counter(&e->counters);
302 ADD_COUNTER(*counter, skb->len, 1);
303
304 t = ipt_get_target_c(e);
305 WARN_ON(!t->u.kernel.target);
306
307#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
308 /* The packet is traced: log it */
309 if (unlikely(skb->nf_trace))
310 trace_packet(state->net, skb, hook, state->in,
311 state->out, table->name, private, e);
312#endif
313 /* Standard target? */
314 if (!t->u.kernel.target->target) {
315 int v;
316
317 v = ((struct xt_standard_target *)t)->verdict;
318 if (v < 0) {
319 /* Pop from stack? */
320 if (v != XT_RETURN) {
321 verdict = (unsigned int)(-v) - 1;
322 break;
323 }
324 if (stackidx == 0) {
325 e = get_entry(table_base,
326 private->underflow[hook]);
327 } else {
328 e = jumpstack[--stackidx];
329 e = ipt_next_entry(e);
330 }
331 continue;
332 }
333 if (table_base + v != ipt_next_entry(e) &&
334 !(e->ip.flags & IPT_F_GOTO)) {
335 if (unlikely(stackidx >= private->stacksize)) {
336 verdict = NF_DROP;
337 break;
338 }
339 jumpstack[stackidx++] = e;
340 }
341
342 e = get_entry(table_base, v);
343 continue;
344 }
345
346 acpar.target = t->u.kernel.target;
347 acpar.targinfo = t->data;
348
349 verdict = t->u.kernel.target->target(skb, &acpar);
350 if (verdict == XT_CONTINUE) {
351 /* Target might have changed stuff. */
352 ip = ip_hdr(skb);
353 e = ipt_next_entry(e);
354 } else {
355 /* Verdict */
356 break;
357 }
358 } while (!acpar.hotdrop);
359
360 xt_write_recseq_end(addend);
361 local_bh_enable();
362
363 if (acpar.hotdrop)
364 return NF_DROP;
365 else return verdict;
366}
367
368/* Figures out from what hook each rule can be called: returns 0 if
369 there are loops. Puts hook bitmask in comefrom. */
370static int
371mark_source_chains(const struct xt_table_info *newinfo,
372 unsigned int valid_hooks, void *entry0,
373 unsigned int *offsets)
374{
375 unsigned int hook;
376
377 /* No recursion; use packet counter to save back ptrs (reset
378 to 0 as we leave), and comefrom to save source hook bitmask */
379 for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
380 unsigned int pos = newinfo->hook_entry[hook];
381 struct ipt_entry *e = entry0 + pos;
382
383 if (!(valid_hooks & (1 << hook)))
384 continue;
385
386 /* Set initial back pointer. */
387 e->counters.pcnt = pos;
388
389 for (;;) {
390 const struct xt_standard_target *t
391 = (void *)ipt_get_target_c(e);
392 int visited = e->comefrom & (1 << hook);
393
394 if (e->comefrom & (1 << NF_INET_NUMHOOKS))
395 return 0;
396
397 e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
398
399 /* Unconditional return/END. */
400 if ((unconditional(e) &&
401 (strcmp(t->target.u.user.name,
402 XT_STANDARD_TARGET) == 0) &&
403 t->verdict < 0) || visited) {
404 unsigned int oldpos, size;
405
406 /* Return: backtrack through the last
407 big jump. */
408 do {
409 e->comefrom ^= (1<<NF_INET_NUMHOOKS);
410 oldpos = pos;
411 pos = e->counters.pcnt;
412 e->counters.pcnt = 0;
413
414 /* We're at the start. */
415 if (pos == oldpos)
416 goto next;
417
418 e = entry0 + pos;
419 } while (oldpos == pos + e->next_offset);
420
421 /* Move along one */
422 size = e->next_offset;
423 e = entry0 + pos + size;
424 if (pos + size >= newinfo->size)
425 return 0;
426 e->counters.pcnt = pos;
427 pos += size;
428 } else {
429 int newpos = t->verdict;
430
431 if (strcmp(t->target.u.user.name,
432 XT_STANDARD_TARGET) == 0 &&
433 newpos >= 0) {
434 /* This a jump; chase it. */
435 if (!xt_find_jump_offset(offsets, newpos,
436 newinfo->number))
437 return 0;
438 } else {
439 /* ... this is a fallthru */
440 newpos = pos + e->next_offset;
441 if (newpos >= newinfo->size)
442 return 0;
443 }
444 e = entry0 + newpos;
445 e->counters.pcnt = pos;
446 pos = newpos;
447 }
448 }
449next: ;
450 }
451 return 1;
452}
453
454static void cleanup_match(struct xt_entry_match *m, struct net *net)
455{
456 struct xt_mtdtor_param par;
457
458 par.net = net;
459 par.match = m->u.kernel.match;
460 par.matchinfo = m->data;
461 par.family = NFPROTO_IPV4;
462 if (par.match->destroy != NULL)
463 par.match->destroy(&par);
464 module_put(par.match->me);
465}
466
467static int
468check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
469{
470 const struct ipt_ip *ip = par->entryinfo;
471
472 par->match = m->u.kernel.match;
473 par->matchinfo = m->data;
474
475 return xt_check_match(par, m->u.match_size - sizeof(*m),
476 ip->proto, ip->invflags & IPT_INV_PROTO);
477}
478
479static int
480find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
481{
482 struct xt_match *match;
483 int ret;
484
485 match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name,
486 m->u.user.revision);
487 if (IS_ERR(match))
488 return PTR_ERR(match);
489 m->u.kernel.match = match;
490
491 ret = check_match(m, par);
492 if (ret)
493 goto err;
494
495 return 0;
496err:
497 module_put(m->u.kernel.match->me);
498 return ret;
499}
500
501static int check_target(struct ipt_entry *e, struct net *net, const char *name)
502{
503 struct xt_entry_target *t = ipt_get_target(e);
504 struct xt_tgchk_param par = {
505 .net = net,
506 .table = name,
507 .entryinfo = e,
508 .target = t->u.kernel.target,
509 .targinfo = t->data,
510 .hook_mask = e->comefrom,
511 .family = NFPROTO_IPV4,
512 };
513
514 return xt_check_target(&par, t->u.target_size - sizeof(*t),
515 e->ip.proto, e->ip.invflags & IPT_INV_PROTO);
516}
517
518static int
519find_check_entry(struct ipt_entry *e, struct net *net, const char *name,
520 unsigned int size,
521 struct xt_percpu_counter_alloc_state *alloc_state)
522{
523 struct xt_entry_target *t;
524 struct xt_target *target;
525 int ret;
526 unsigned int j;
527 struct xt_mtchk_param mtpar;
528 struct xt_entry_match *ematch;
529
530 if (!xt_percpu_counter_alloc(alloc_state, &e->counters))
531 return -ENOMEM;
532
533 j = 0;
534 memset(&mtpar, 0, sizeof(mtpar));
535 mtpar.net = net;
536 mtpar.table = name;
537 mtpar.entryinfo = &e->ip;
538 mtpar.hook_mask = e->comefrom;
539 mtpar.family = NFPROTO_IPV4;
540 xt_ematch_foreach(ematch, e) {
541 ret = find_check_match(ematch, &mtpar);
542 if (ret != 0)
543 goto cleanup_matches;
544 ++j;
545 }
546
547 t = ipt_get_target(e);
548 target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name,
549 t->u.user.revision);
550 if (IS_ERR(target)) {
551 ret = PTR_ERR(target);
552 goto cleanup_matches;
553 }
554 t->u.kernel.target = target;
555
556 ret = check_target(e, net, name);
557 if (ret)
558 goto err;
559
560 return 0;
561 err:
562 module_put(t->u.kernel.target->me);
563 cleanup_matches:
564 xt_ematch_foreach(ematch, e) {
565 if (j-- == 0)
566 break;
567 cleanup_match(ematch, net);
568 }
569
570 xt_percpu_counter_free(&e->counters);
571
572 return ret;
573}
574
575static bool check_underflow(const struct ipt_entry *e)
576{
577 const struct xt_entry_target *t;
578 unsigned int verdict;
579
580 if (!unconditional(e))
581 return false;
582 t = ipt_get_target_c(e);
583 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
584 return false;
585 verdict = ((struct xt_standard_target *)t)->verdict;
586 verdict = -verdict - 1;
587 return verdict == NF_DROP || verdict == NF_ACCEPT;
588}
589
590static int
591check_entry_size_and_hooks(struct ipt_entry *e,
592 struct xt_table_info *newinfo,
593 const unsigned char *base,
594 const unsigned char *limit,
595 const unsigned int *hook_entries,
596 const unsigned int *underflows,
597 unsigned int valid_hooks)
598{
599 unsigned int h;
600 int err;
601
602 if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 ||
603 (unsigned char *)e + sizeof(struct ipt_entry) >= limit ||
604 (unsigned char *)e + e->next_offset > limit)
605 return -EINVAL;
606
607 if (e->next_offset
608 < sizeof(struct ipt_entry) + sizeof(struct xt_entry_target))
609 return -EINVAL;
610
611 if (!ip_checkentry(&e->ip))
612 return -EINVAL;
613
614 err = xt_check_entry_offsets(e, e->elems, e->target_offset,
615 e->next_offset);
616 if (err)
617 return err;
618
619 /* Check hooks & underflows */
620 for (h = 0; h < NF_INET_NUMHOOKS; h++) {
621 if (!(valid_hooks & (1 << h)))
622 continue;
623 if ((unsigned char *)e - base == hook_entries[h])
624 newinfo->hook_entry[h] = hook_entries[h];
625 if ((unsigned char *)e - base == underflows[h]) {
626 if (!check_underflow(e))
627 return -EINVAL;
628
629 newinfo->underflow[h] = underflows[h];
630 }
631 }
632
633 /* Clear counters and comefrom */
634 e->counters = ((struct xt_counters) { 0, 0 });
635 e->comefrom = 0;
636 return 0;
637}
638
639static void
640cleanup_entry(struct ipt_entry *e, struct net *net)
641{
642 struct xt_tgdtor_param par;
643 struct xt_entry_target *t;
644 struct xt_entry_match *ematch;
645
646 /* Cleanup all matches */
647 xt_ematch_foreach(ematch, e)
648 cleanup_match(ematch, net);
649 t = ipt_get_target(e);
650
651 par.net = net;
652 par.target = t->u.kernel.target;
653 par.targinfo = t->data;
654 par.family = NFPROTO_IPV4;
655 if (par.target->destroy != NULL)
656 par.target->destroy(&par);
657 module_put(par.target->me);
658 xt_percpu_counter_free(&e->counters);
659}
660
661/* Checks and translates the user-supplied table segment (held in
662 newinfo) */
663static int
664translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
665 const struct ipt_replace *repl)
666{
667 struct xt_percpu_counter_alloc_state alloc_state = { 0 };
668 struct ipt_entry *iter;
669 unsigned int *offsets;
670 unsigned int i;
671 int ret = 0;
672
673 newinfo->size = repl->size;
674 newinfo->number = repl->num_entries;
675
676 /* Init all hooks to impossible value. */
677 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
678 newinfo->hook_entry[i] = 0xFFFFFFFF;
679 newinfo->underflow[i] = 0xFFFFFFFF;
680 }
681
682 offsets = xt_alloc_entry_offsets(newinfo->number);
683 if (!offsets)
684 return -ENOMEM;
685 i = 0;
686 /* Walk through entries, checking offsets. */
687 xt_entry_foreach(iter, entry0, newinfo->size) {
688 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
689 entry0 + repl->size,
690 repl->hook_entry,
691 repl->underflow,
692 repl->valid_hooks);
693 if (ret != 0)
694 goto out_free;
695 if (i < repl->num_entries)
696 offsets[i] = (void *)iter - entry0;
697 ++i;
698 if (strcmp(ipt_get_target(iter)->u.user.name,
699 XT_ERROR_TARGET) == 0)
700 ++newinfo->stacksize;
701 }
702
703 ret = -EINVAL;
704 if (i != repl->num_entries)
705 goto out_free;
706
707 ret = xt_check_table_hooks(newinfo, repl->valid_hooks);
708 if (ret)
709 goto out_free;
710
711 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) {
712 ret = -ELOOP;
713 goto out_free;
714 }
715 kvfree(offsets);
716
717 /* Finally, each sanity check must pass */
718 i = 0;
719 xt_entry_foreach(iter, entry0, newinfo->size) {
720 ret = find_check_entry(iter, net, repl->name, repl->size,
721 &alloc_state);
722 if (ret != 0)
723 break;
724 ++i;
725 }
726
727 if (ret != 0) {
728 xt_entry_foreach(iter, entry0, newinfo->size) {
729 if (i-- == 0)
730 break;
731 cleanup_entry(iter, net);
732 }
733 return ret;
734 }
735
736 return ret;
737 out_free:
738 kvfree(offsets);
739 return ret;
740}
741
742static void
743get_counters(const struct xt_table_info *t,
744 struct xt_counters counters[])
745{
746 struct ipt_entry *iter;
747 unsigned int cpu;
748 unsigned int i;
749
750 for_each_possible_cpu(cpu) {
751 seqcount_t *s = &per_cpu(xt_recseq, cpu);
752
753 i = 0;
754 xt_entry_foreach(iter, t->entries, t->size) {
755 struct xt_counters *tmp;
756 u64 bcnt, pcnt;
757 unsigned int start;
758
759 tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
760 do {
761 start = read_seqcount_begin(s);
762 bcnt = tmp->bcnt;
763 pcnt = tmp->pcnt;
764 } while (read_seqcount_retry(s, start));
765
766 ADD_COUNTER(counters[i], bcnt, pcnt);
767 ++i; /* macro does multi eval of i */
768 cond_resched();
769 }
770 }
771}
772
773static void get_old_counters(const struct xt_table_info *t,
774 struct xt_counters counters[])
775{
776 struct ipt_entry *iter;
777 unsigned int cpu, i;
778
779 for_each_possible_cpu(cpu) {
780 i = 0;
781 xt_entry_foreach(iter, t->entries, t->size) {
782 const struct xt_counters *tmp;
783
784 tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
785 ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt);
786 ++i; /* macro does multi eval of i */
787 }
788
789 cond_resched();
790 }
791}
792
793static struct xt_counters *alloc_counters(const struct xt_table *table)
794{
795 unsigned int countersize;
796 struct xt_counters *counters;
797 const struct xt_table_info *private = table->private;
798
799 /* We need atomic snapshot of counters: rest doesn't change
800 (other than comefrom, which userspace doesn't care
801 about). */
802 countersize = sizeof(struct xt_counters) * private->number;
803 counters = vzalloc(countersize);
804
805 if (counters == NULL)
806 return ERR_PTR(-ENOMEM);
807
808 get_counters(private, counters);
809
810 return counters;
811}
812
813static int
814copy_entries_to_user(unsigned int total_size,
815 const struct xt_table *table,
816 void __user *userptr)
817{
818 unsigned int off, num;
819 const struct ipt_entry *e;
820 struct xt_counters *counters;
821 const struct xt_table_info *private = table->private;
822 int ret = 0;
823 const void *loc_cpu_entry;
824
825 counters = alloc_counters(table);
826 if (IS_ERR(counters))
827 return PTR_ERR(counters);
828
829 loc_cpu_entry = private->entries;
830
831 /* FIXME: use iterator macros --RR */
832 /* ... then go back and fix counters and names */
833 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
834 unsigned int i;
835 const struct xt_entry_match *m;
836 const struct xt_entry_target *t;
837
838 e = loc_cpu_entry + off;
839 if (copy_to_user(userptr + off, e, sizeof(*e))) {
840 ret = -EFAULT;
841 goto free_counters;
842 }
843 if (copy_to_user(userptr + off
844 + offsetof(struct ipt_entry, counters),
845 &counters[num],
846 sizeof(counters[num])) != 0) {
847 ret = -EFAULT;
848 goto free_counters;
849 }
850
851 for (i = sizeof(struct ipt_entry);
852 i < e->target_offset;
853 i += m->u.match_size) {
854 m = (void *)e + i;
855
856 if (xt_match_to_user(m, userptr + off + i)) {
857 ret = -EFAULT;
858 goto free_counters;
859 }
860 }
861
862 t = ipt_get_target_c(e);
863 if (xt_target_to_user(t, userptr + off + e->target_offset)) {
864 ret = -EFAULT;
865 goto free_counters;
866 }
867 }
868
869 free_counters:
870 vfree(counters);
871 return ret;
872}
873
874#ifdef CONFIG_COMPAT
875static void compat_standard_from_user(void *dst, const void *src)
876{
877 int v = *(compat_int_t *)src;
878
879 if (v > 0)
880 v += xt_compat_calc_jump(AF_INET, v);
881 memcpy(dst, &v, sizeof(v));
882}
883
884static int compat_standard_to_user(void __user *dst, const void *src)
885{
886 compat_int_t cv = *(int *)src;
887
888 if (cv > 0)
889 cv -= xt_compat_calc_jump(AF_INET, cv);
890 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
891}
892
893static int compat_calc_entry(const struct ipt_entry *e,
894 const struct xt_table_info *info,
895 const void *base, struct xt_table_info *newinfo)
896{
897 const struct xt_entry_match *ematch;
898 const struct xt_entry_target *t;
899 unsigned int entry_offset;
900 int off, i, ret;
901
902 off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
903 entry_offset = (void *)e - base;
904 xt_ematch_foreach(ematch, e)
905 off += xt_compat_match_offset(ematch->u.kernel.match);
906 t = ipt_get_target_c(e);
907 off += xt_compat_target_offset(t->u.kernel.target);
908 newinfo->size -= off;
909 ret = xt_compat_add_offset(AF_INET, entry_offset, off);
910 if (ret)
911 return ret;
912
913 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
914 if (info->hook_entry[i] &&
915 (e < (struct ipt_entry *)(base + info->hook_entry[i])))
916 newinfo->hook_entry[i] -= off;
917 if (info->underflow[i] &&
918 (e < (struct ipt_entry *)(base + info->underflow[i])))
919 newinfo->underflow[i] -= off;
920 }
921 return 0;
922}
923
924static int compat_table_info(const struct xt_table_info *info,
925 struct xt_table_info *newinfo)
926{
927 struct ipt_entry *iter;
928 const void *loc_cpu_entry;
929 int ret;
930
931 if (!newinfo || !info)
932 return -EINVAL;
933
934 /* we dont care about newinfo->entries */
935 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
936 newinfo->initial_entries = 0;
937 loc_cpu_entry = info->entries;
938 ret = xt_compat_init_offsets(AF_INET, info->number);
939 if (ret)
940 return ret;
941 xt_entry_foreach(iter, loc_cpu_entry, info->size) {
942 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
943 if (ret != 0)
944 return ret;
945 }
946 return 0;
947}
948#endif
949
950static int get_info(struct net *net, void __user *user,
951 const int *len, int compat)
952{
953 char name[XT_TABLE_MAXNAMELEN];
954 struct xt_table *t;
955 int ret;
956
957 if (*len != sizeof(struct ipt_getinfo))
958 return -EINVAL;
959
960 if (copy_from_user(name, user, sizeof(name)) != 0)
961 return -EFAULT;
962
963 name[XT_TABLE_MAXNAMELEN-1] = '\0';
964#ifdef CONFIG_COMPAT
965 if (compat)
966 xt_compat_lock(AF_INET);
967#endif
968 t = xt_request_find_table_lock(net, AF_INET, name);
969 if (!IS_ERR(t)) {
970 struct ipt_getinfo info;
971 const struct xt_table_info *private = t->private;
972#ifdef CONFIG_COMPAT
973 struct xt_table_info tmp;
974
975 if (compat) {
976 ret = compat_table_info(private, &tmp);
977 xt_compat_flush_offsets(AF_INET);
978 private = &tmp;
979 }
980#endif
981 memset(&info, 0, sizeof(info));
982 info.valid_hooks = t->valid_hooks;
983 memcpy(info.hook_entry, private->hook_entry,
984 sizeof(info.hook_entry));
985 memcpy(info.underflow, private->underflow,
986 sizeof(info.underflow));
987 info.num_entries = private->number;
988 info.size = private->size;
989 strcpy(info.name, name);
990
991 if (copy_to_user(user, &info, *len) != 0)
992 ret = -EFAULT;
993 else
994 ret = 0;
995
996 xt_table_unlock(t);
997 module_put(t->me);
998 } else
999 ret = PTR_ERR(t);
1000#ifdef CONFIG_COMPAT
1001 if (compat)
1002 xt_compat_unlock(AF_INET);
1003#endif
1004 return ret;
1005}
1006
1007static int
1008get_entries(struct net *net, struct ipt_get_entries __user *uptr,
1009 const int *len)
1010{
1011 int ret;
1012 struct ipt_get_entries get;
1013 struct xt_table *t;
1014
1015 if (*len < sizeof(get))
1016 return -EINVAL;
1017 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1018 return -EFAULT;
1019 if (*len != sizeof(struct ipt_get_entries) + get.size)
1020 return -EINVAL;
1021 get.name[sizeof(get.name) - 1] = '\0';
1022
1023 t = xt_find_table_lock(net, AF_INET, get.name);
1024 if (!IS_ERR(t)) {
1025 const struct xt_table_info *private = t->private;
1026 if (get.size == private->size)
1027 ret = copy_entries_to_user(private->size,
1028 t, uptr->entrytable);
1029 else
1030 ret = -EAGAIN;
1031
1032 module_put(t->me);
1033 xt_table_unlock(t);
1034 } else
1035 ret = PTR_ERR(t);
1036
1037 return ret;
1038}
1039
1040static int
1041__do_replace(struct net *net, const char *name, unsigned int valid_hooks,
1042 struct xt_table_info *newinfo, unsigned int num_counters,
1043 void __user *counters_ptr)
1044{
1045 int ret;
1046 struct xt_table *t;
1047 struct xt_table_info *oldinfo;
1048 struct xt_counters *counters;
1049 struct ipt_entry *iter;
1050
1051 ret = 0;
1052 counters = xt_counters_alloc(num_counters);
1053 if (!counters) {
1054 ret = -ENOMEM;
1055 goto out;
1056 }
1057
1058 t = xt_request_find_table_lock(net, AF_INET, name);
1059 if (IS_ERR(t)) {
1060 ret = PTR_ERR(t);
1061 goto free_newinfo_counters_untrans;
1062 }
1063
1064 /* You lied! */
1065 if (valid_hooks != t->valid_hooks) {
1066 ret = -EINVAL;
1067 goto put_module;
1068 }
1069
1070 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1071 if (!oldinfo)
1072 goto put_module;
1073
1074 /* Update module usage count based on number of rules */
1075 if ((oldinfo->number > oldinfo->initial_entries) ||
1076 (newinfo->number <= oldinfo->initial_entries))
1077 module_put(t->me);
1078 if ((oldinfo->number > oldinfo->initial_entries) &&
1079 (newinfo->number <= oldinfo->initial_entries))
1080 module_put(t->me);
1081
1082 xt_table_unlock(t);
1083
1084 get_old_counters(oldinfo, counters);
1085
1086 /* Decrease module usage counts and free resource */
1087 xt_entry_foreach(iter, oldinfo->entries, oldinfo->size)
1088 cleanup_entry(iter, net);
1089
1090 xt_free_table_info(oldinfo);
1091 if (copy_to_user(counters_ptr, counters,
1092 sizeof(struct xt_counters) * num_counters) != 0) {
1093 /* Silent error, can't fail, new table is already in place */
1094 net_warn_ratelimited("iptables: counters copy to user failed while replacing table\n");
1095 }
1096 vfree(counters);
1097 return ret;
1098
1099 put_module:
1100 module_put(t->me);
1101 xt_table_unlock(t);
1102 free_newinfo_counters_untrans:
1103 vfree(counters);
1104 out:
1105 return ret;
1106}
1107
1108static int
1109do_replace(struct net *net, const void __user *user, unsigned int len)
1110{
1111 int ret;
1112 struct ipt_replace tmp;
1113 struct xt_table_info *newinfo;
1114 void *loc_cpu_entry;
1115 struct ipt_entry *iter;
1116
1117 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1118 return -EFAULT;
1119
1120 /* overflow check */
1121 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1122 return -ENOMEM;
1123 if (tmp.num_counters == 0)
1124 return -EINVAL;
1125
1126 tmp.name[sizeof(tmp.name)-1] = 0;
1127
1128 newinfo = xt_alloc_table_info(tmp.size);
1129 if (!newinfo)
1130 return -ENOMEM;
1131
1132 loc_cpu_entry = newinfo->entries;
1133 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1134 tmp.size) != 0) {
1135 ret = -EFAULT;
1136 goto free_newinfo;
1137 }
1138
1139 ret = translate_table(net, newinfo, loc_cpu_entry, &tmp);
1140 if (ret != 0)
1141 goto free_newinfo;
1142
1143 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1144 tmp.num_counters, tmp.counters);
1145 if (ret)
1146 goto free_newinfo_untrans;
1147 return 0;
1148
1149 free_newinfo_untrans:
1150 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1151 cleanup_entry(iter, net);
1152 free_newinfo:
1153 xt_free_table_info(newinfo);
1154 return ret;
1155}
1156
1157static int
1158do_add_counters(struct net *net, const void __user *user,
1159 unsigned int len, int compat)
1160{
1161 unsigned int i;
1162 struct xt_counters_info tmp;
1163 struct xt_counters *paddc;
1164 struct xt_table *t;
1165 const struct xt_table_info *private;
1166 int ret = 0;
1167 struct ipt_entry *iter;
1168 unsigned int addend;
1169
1170 paddc = xt_copy_counters_from_user(user, len, &tmp, compat);
1171 if (IS_ERR(paddc))
1172 return PTR_ERR(paddc);
1173
1174 t = xt_find_table_lock(net, AF_INET, tmp.name);
1175 if (IS_ERR(t)) {
1176 ret = PTR_ERR(t);
1177 goto free;
1178 }
1179
1180 local_bh_disable();
1181 private = t->private;
1182 if (private->number != tmp.num_counters) {
1183 ret = -EINVAL;
1184 goto unlock_up_free;
1185 }
1186
1187 i = 0;
1188 addend = xt_write_recseq_begin();
1189 xt_entry_foreach(iter, private->entries, private->size) {
1190 struct xt_counters *tmp;
1191
1192 tmp = xt_get_this_cpu_counter(&iter->counters);
1193 ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt);
1194 ++i;
1195 }
1196 xt_write_recseq_end(addend);
1197 unlock_up_free:
1198 local_bh_enable();
1199 xt_table_unlock(t);
1200 module_put(t->me);
1201 free:
1202 vfree(paddc);
1203
1204 return ret;
1205}
1206
1207#ifdef CONFIG_COMPAT
1208struct compat_ipt_replace {
1209 char name[XT_TABLE_MAXNAMELEN];
1210 u32 valid_hooks;
1211 u32 num_entries;
1212 u32 size;
1213 u32 hook_entry[NF_INET_NUMHOOKS];
1214 u32 underflow[NF_INET_NUMHOOKS];
1215 u32 num_counters;
1216 compat_uptr_t counters; /* struct xt_counters * */
1217 struct compat_ipt_entry entries[0];
1218};
1219
1220static int
1221compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr,
1222 unsigned int *size, struct xt_counters *counters,
1223 unsigned int i)
1224{
1225 struct xt_entry_target *t;
1226 struct compat_ipt_entry __user *ce;
1227 u_int16_t target_offset, next_offset;
1228 compat_uint_t origsize;
1229 const struct xt_entry_match *ematch;
1230 int ret = 0;
1231
1232 origsize = *size;
1233 ce = *dstptr;
1234 if (copy_to_user(ce, e, sizeof(struct ipt_entry)) != 0 ||
1235 copy_to_user(&ce->counters, &counters[i],
1236 sizeof(counters[i])) != 0)
1237 return -EFAULT;
1238
1239 *dstptr += sizeof(struct compat_ipt_entry);
1240 *size -= sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1241
1242 xt_ematch_foreach(ematch, e) {
1243 ret = xt_compat_match_to_user(ematch, dstptr, size);
1244 if (ret != 0)
1245 return ret;
1246 }
1247 target_offset = e->target_offset - (origsize - *size);
1248 t = ipt_get_target(e);
1249 ret = xt_compat_target_to_user(t, dstptr, size);
1250 if (ret)
1251 return ret;
1252 next_offset = e->next_offset - (origsize - *size);
1253 if (put_user(target_offset, &ce->target_offset) != 0 ||
1254 put_user(next_offset, &ce->next_offset) != 0)
1255 return -EFAULT;
1256 return 0;
1257}
1258
1259static int
1260compat_find_calc_match(struct xt_entry_match *m,
1261 const struct ipt_ip *ip,
1262 int *size)
1263{
1264 struct xt_match *match;
1265
1266 match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name,
1267 m->u.user.revision);
1268 if (IS_ERR(match))
1269 return PTR_ERR(match);
1270
1271 m->u.kernel.match = match;
1272 *size += xt_compat_match_offset(match);
1273 return 0;
1274}
1275
1276static void compat_release_entry(struct compat_ipt_entry *e)
1277{
1278 struct xt_entry_target *t;
1279 struct xt_entry_match *ematch;
1280
1281 /* Cleanup all matches */
1282 xt_ematch_foreach(ematch, e)
1283 module_put(ematch->u.kernel.match->me);
1284 t = compat_ipt_get_target(e);
1285 module_put(t->u.kernel.target->me);
1286}
1287
1288static int
1289check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
1290 struct xt_table_info *newinfo,
1291 unsigned int *size,
1292 const unsigned char *base,
1293 const unsigned char *limit)
1294{
1295 struct xt_entry_match *ematch;
1296 struct xt_entry_target *t;
1297 struct xt_target *target;
1298 unsigned int entry_offset;
1299 unsigned int j;
1300 int ret, off;
1301
1302 if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0 ||
1303 (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit ||
1304 (unsigned char *)e + e->next_offset > limit)
1305 return -EINVAL;
1306
1307 if (e->next_offset < sizeof(struct compat_ipt_entry) +
1308 sizeof(struct compat_xt_entry_target))
1309 return -EINVAL;
1310
1311 if (!ip_checkentry(&e->ip))
1312 return -EINVAL;
1313
1314 ret = xt_compat_check_entry_offsets(e, e->elems,
1315 e->target_offset, e->next_offset);
1316 if (ret)
1317 return ret;
1318
1319 off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1320 entry_offset = (void *)e - (void *)base;
1321 j = 0;
1322 xt_ematch_foreach(ematch, e) {
1323 ret = compat_find_calc_match(ematch, &e->ip, &off);
1324 if (ret != 0)
1325 goto release_matches;
1326 ++j;
1327 }
1328
1329 t = compat_ipt_get_target(e);
1330 target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name,
1331 t->u.user.revision);
1332 if (IS_ERR(target)) {
1333 ret = PTR_ERR(target);
1334 goto release_matches;
1335 }
1336 t->u.kernel.target = target;
1337
1338 off += xt_compat_target_offset(target);
1339 *size += off;
1340 ret = xt_compat_add_offset(AF_INET, entry_offset, off);
1341 if (ret)
1342 goto out;
1343
1344 return 0;
1345
1346out:
1347 module_put(t->u.kernel.target->me);
1348release_matches:
1349 xt_ematch_foreach(ematch, e) {
1350 if (j-- == 0)
1351 break;
1352 module_put(ematch->u.kernel.match->me);
1353 }
1354 return ret;
1355}
1356
1357static void
1358compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
1359 unsigned int *size,
1360 struct xt_table_info *newinfo, unsigned char *base)
1361{
1362 struct xt_entry_target *t;
1363 struct ipt_entry *de;
1364 unsigned int origsize;
1365 int h;
1366 struct xt_entry_match *ematch;
1367
1368 origsize = *size;
1369 de = *dstptr;
1370 memcpy(de, e, sizeof(struct ipt_entry));
1371 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1372
1373 *dstptr += sizeof(struct ipt_entry);
1374 *size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1375
1376 xt_ematch_foreach(ematch, e)
1377 xt_compat_match_from_user(ematch, dstptr, size);
1378
1379 de->target_offset = e->target_offset - (origsize - *size);
1380 t = compat_ipt_get_target(e);
1381 xt_compat_target_from_user(t, dstptr, size);
1382
1383 de->next_offset = e->next_offset - (origsize - *size);
1384
1385 for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1386 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1387 newinfo->hook_entry[h] -= origsize - *size;
1388 if ((unsigned char *)de - base < newinfo->underflow[h])
1389 newinfo->underflow[h] -= origsize - *size;
1390 }
1391}
1392
1393static int
1394translate_compat_table(struct net *net,
1395 struct xt_table_info **pinfo,
1396 void **pentry0,
1397 const struct compat_ipt_replace *compatr)
1398{
1399 unsigned int i, j;
1400 struct xt_table_info *newinfo, *info;
1401 void *pos, *entry0, *entry1;
1402 struct compat_ipt_entry *iter0;
1403 struct ipt_replace repl;
1404 unsigned int size;
1405 int ret;
1406
1407 info = *pinfo;
1408 entry0 = *pentry0;
1409 size = compatr->size;
1410 info->number = compatr->num_entries;
1411
1412 j = 0;
1413 xt_compat_lock(AF_INET);
1414 ret = xt_compat_init_offsets(AF_INET, compatr->num_entries);
1415 if (ret)
1416 goto out_unlock;
1417 /* Walk through entries, checking offsets. */
1418 xt_entry_foreach(iter0, entry0, compatr->size) {
1419 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1420 entry0,
1421 entry0 + compatr->size);
1422 if (ret != 0)
1423 goto out_unlock;
1424 ++j;
1425 }
1426
1427 ret = -EINVAL;
1428 if (j != compatr->num_entries)
1429 goto out_unlock;
1430
1431 ret = -ENOMEM;
1432 newinfo = xt_alloc_table_info(size);
1433 if (!newinfo)
1434 goto out_unlock;
1435
1436 newinfo->number = compatr->num_entries;
1437 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1438 newinfo->hook_entry[i] = compatr->hook_entry[i];
1439 newinfo->underflow[i] = compatr->underflow[i];
1440 }
1441 entry1 = newinfo->entries;
1442 pos = entry1;
1443 size = compatr->size;
1444 xt_entry_foreach(iter0, entry0, compatr->size)
1445 compat_copy_entry_from_user(iter0, &pos, &size,
1446 newinfo, entry1);
1447
1448 /* all module references in entry0 are now gone.
1449 * entry1/newinfo contains a 64bit ruleset that looks exactly as
1450 * generated by 64bit userspace.
1451 *
1452 * Call standard translate_table() to validate all hook_entrys,
1453 * underflows, check for loops, etc.
1454 */
1455 xt_compat_flush_offsets(AF_INET);
1456 xt_compat_unlock(AF_INET);
1457
1458 memcpy(&repl, compatr, sizeof(*compatr));
1459
1460 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1461 repl.hook_entry[i] = newinfo->hook_entry[i];
1462 repl.underflow[i] = newinfo->underflow[i];
1463 }
1464
1465 repl.num_counters = 0;
1466 repl.counters = NULL;
1467 repl.size = newinfo->size;
1468 ret = translate_table(net, newinfo, entry1, &repl);
1469 if (ret)
1470 goto free_newinfo;
1471
1472 *pinfo = newinfo;
1473 *pentry0 = entry1;
1474 xt_free_table_info(info);
1475 return 0;
1476
1477free_newinfo:
1478 xt_free_table_info(newinfo);
1479 return ret;
1480out_unlock:
1481 xt_compat_flush_offsets(AF_INET);
1482 xt_compat_unlock(AF_INET);
1483 xt_entry_foreach(iter0, entry0, compatr->size) {
1484 if (j-- == 0)
1485 break;
1486 compat_release_entry(iter0);
1487 }
1488 return ret;
1489}
1490
1491static int
1492compat_do_replace(struct net *net, void __user *user, unsigned int len)
1493{
1494 int ret;
1495 struct compat_ipt_replace tmp;
1496 struct xt_table_info *newinfo;
1497 void *loc_cpu_entry;
1498 struct ipt_entry *iter;
1499
1500 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1501 return -EFAULT;
1502
1503 /* overflow check */
1504 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1505 return -ENOMEM;
1506 if (tmp.num_counters == 0)
1507 return -EINVAL;
1508
1509 tmp.name[sizeof(tmp.name)-1] = 0;
1510
1511 newinfo = xt_alloc_table_info(tmp.size);
1512 if (!newinfo)
1513 return -ENOMEM;
1514
1515 loc_cpu_entry = newinfo->entries;
1516 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1517 tmp.size) != 0) {
1518 ret = -EFAULT;
1519 goto free_newinfo;
1520 }
1521
1522 ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp);
1523 if (ret != 0)
1524 goto free_newinfo;
1525
1526 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1527 tmp.num_counters, compat_ptr(tmp.counters));
1528 if (ret)
1529 goto free_newinfo_untrans;
1530 return 0;
1531
1532 free_newinfo_untrans:
1533 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1534 cleanup_entry(iter, net);
1535 free_newinfo:
1536 xt_free_table_info(newinfo);
1537 return ret;
1538}
1539
1540static int
1541compat_do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user,
1542 unsigned int len)
1543{
1544 int ret;
1545
1546 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1547 return -EPERM;
1548
1549 switch (cmd) {
1550 case IPT_SO_SET_REPLACE:
1551 ret = compat_do_replace(sock_net(sk), user, len);
1552 break;
1553
1554 case IPT_SO_SET_ADD_COUNTERS:
1555 ret = do_add_counters(sock_net(sk), user, len, 1);
1556 break;
1557
1558 default:
1559 ret = -EINVAL;
1560 }
1561
1562 return ret;
1563}
1564
1565struct compat_ipt_get_entries {
1566 char name[XT_TABLE_MAXNAMELEN];
1567 compat_uint_t size;
1568 struct compat_ipt_entry entrytable[0];
1569};
1570
1571static int
1572compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
1573 void __user *userptr)
1574{
1575 struct xt_counters *counters;
1576 const struct xt_table_info *private = table->private;
1577 void __user *pos;
1578 unsigned int size;
1579 int ret = 0;
1580 unsigned int i = 0;
1581 struct ipt_entry *iter;
1582
1583 counters = alloc_counters(table);
1584 if (IS_ERR(counters))
1585 return PTR_ERR(counters);
1586
1587 pos = userptr;
1588 size = total_size;
1589 xt_entry_foreach(iter, private->entries, total_size) {
1590 ret = compat_copy_entry_to_user(iter, &pos,
1591 &size, counters, i++);
1592 if (ret != 0)
1593 break;
1594 }
1595
1596 vfree(counters);
1597 return ret;
1598}
1599
1600static int
1601compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr,
1602 int *len)
1603{
1604 int ret;
1605 struct compat_ipt_get_entries get;
1606 struct xt_table *t;
1607
1608 if (*len < sizeof(get))
1609 return -EINVAL;
1610
1611 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1612 return -EFAULT;
1613
1614 if (*len != sizeof(struct compat_ipt_get_entries) + get.size)
1615 return -EINVAL;
1616
1617 get.name[sizeof(get.name) - 1] = '\0';
1618
1619 xt_compat_lock(AF_INET);
1620 t = xt_find_table_lock(net, AF_INET, get.name);
1621 if (!IS_ERR(t)) {
1622 const struct xt_table_info *private = t->private;
1623 struct xt_table_info info;
1624 ret = compat_table_info(private, &info);
1625 if (!ret && get.size == info.size)
1626 ret = compat_copy_entries_to_user(private->size,
1627 t, uptr->entrytable);
1628 else if (!ret)
1629 ret = -EAGAIN;
1630
1631 xt_compat_flush_offsets(AF_INET);
1632 module_put(t->me);
1633 xt_table_unlock(t);
1634 } else
1635 ret = PTR_ERR(t);
1636
1637 xt_compat_unlock(AF_INET);
1638 return ret;
1639}
1640
1641static int do_ipt_get_ctl(struct sock *, int, void __user *, int *);
1642
1643static int
1644compat_do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1645{
1646 int ret;
1647
1648 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1649 return -EPERM;
1650
1651 switch (cmd) {
1652 case IPT_SO_GET_INFO:
1653 ret = get_info(sock_net(sk), user, len, 1);
1654 break;
1655 case IPT_SO_GET_ENTRIES:
1656 ret = compat_get_entries(sock_net(sk), user, len);
1657 break;
1658 default:
1659 ret = do_ipt_get_ctl(sk, cmd, user, len);
1660 }
1661 return ret;
1662}
1663#endif
1664
1665static int
1666do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1667{
1668 int ret;
1669
1670 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1671 return -EPERM;
1672
1673 switch (cmd) {
1674 case IPT_SO_SET_REPLACE:
1675 ret = do_replace(sock_net(sk), user, len);
1676 break;
1677
1678 case IPT_SO_SET_ADD_COUNTERS:
1679 ret = do_add_counters(sock_net(sk), user, len, 0);
1680 break;
1681
1682 default:
1683 ret = -EINVAL;
1684 }
1685
1686 return ret;
1687}
1688
1689static int
1690do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1691{
1692 int ret;
1693
1694 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1695 return -EPERM;
1696
1697 switch (cmd) {
1698 case IPT_SO_GET_INFO:
1699 ret = get_info(sock_net(sk), user, len, 0);
1700 break;
1701
1702 case IPT_SO_GET_ENTRIES:
1703 ret = get_entries(sock_net(sk), user, len);
1704 break;
1705
1706 case IPT_SO_GET_REVISION_MATCH:
1707 case IPT_SO_GET_REVISION_TARGET: {
1708 struct xt_get_revision rev;
1709 int target;
1710
1711 if (*len != sizeof(rev)) {
1712 ret = -EINVAL;
1713 break;
1714 }
1715 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1716 ret = -EFAULT;
1717 break;
1718 }
1719 rev.name[sizeof(rev.name)-1] = 0;
1720
1721 if (cmd == IPT_SO_GET_REVISION_TARGET)
1722 target = 1;
1723 else
1724 target = 0;
1725
1726 try_then_request_module(xt_find_revision(AF_INET, rev.name,
1727 rev.revision,
1728 target, &ret),
1729 "ipt_%s", rev.name);
1730 break;
1731 }
1732
1733 default:
1734 ret = -EINVAL;
1735 }
1736
1737 return ret;
1738}
1739
1740static void __ipt_unregister_table(struct net *net, struct xt_table *table)
1741{
1742 struct xt_table_info *private;
1743 void *loc_cpu_entry;
1744 struct module *table_owner = table->me;
1745 struct ipt_entry *iter;
1746
1747 private = xt_unregister_table(table);
1748
1749 /* Decrease module usage counts and free resources */
1750 loc_cpu_entry = private->entries;
1751 xt_entry_foreach(iter, loc_cpu_entry, private->size)
1752 cleanup_entry(iter, net);
1753 if (private->number > private->initial_entries)
1754 module_put(table_owner);
1755 xt_free_table_info(private);
1756}
1757
1758int ipt_register_table(struct net *net, const struct xt_table *table,
1759 const struct ipt_replace *repl,
1760 const struct nf_hook_ops *ops, struct xt_table **res)
1761{
1762 int ret;
1763 struct xt_table_info *newinfo;
1764 struct xt_table_info bootstrap = {0};
1765 void *loc_cpu_entry;
1766 struct xt_table *new_table;
1767
1768 newinfo = xt_alloc_table_info(repl->size);
1769 if (!newinfo)
1770 return -ENOMEM;
1771
1772 loc_cpu_entry = newinfo->entries;
1773 memcpy(loc_cpu_entry, repl->entries, repl->size);
1774
1775 ret = translate_table(net, newinfo, loc_cpu_entry, repl);
1776 if (ret != 0)
1777 goto out_free;
1778
1779 new_table = xt_register_table(net, table, &bootstrap, newinfo);
1780 if (IS_ERR(new_table)) {
1781 ret = PTR_ERR(new_table);
1782 goto out_free;
1783 }
1784
1785 /* set res now, will see skbs right after nf_register_net_hooks */
1786 WRITE_ONCE(*res, new_table);
1787 if (!ops)
1788 return 0;
1789
1790 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
1791 if (ret != 0) {
1792 __ipt_unregister_table(net, new_table);
1793 *res = NULL;
1794 }
1795
1796 return ret;
1797
1798out_free:
1799 xt_free_table_info(newinfo);
1800 return ret;
1801}
1802
1803void ipt_unregister_table(struct net *net, struct xt_table *table,
1804 const struct nf_hook_ops *ops)
1805{
1806 if (ops)
1807 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
1808 __ipt_unregister_table(net, table);
1809}
1810
1811/* Returns 1 if the type and code is matched by the range, 0 otherwise */
1812static inline bool
1813icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
1814 u_int8_t type, u_int8_t code,
1815 bool invert)
1816{
1817 return ((test_type == 0xFF) ||
1818 (type == test_type && code >= min_code && code <= max_code))
1819 ^ invert;
1820}
1821
1822static bool
1823icmp_match(const struct sk_buff *skb, struct xt_action_param *par)
1824{
1825 const struct icmphdr *ic;
1826 struct icmphdr _icmph;
1827 const struct ipt_icmp *icmpinfo = par->matchinfo;
1828
1829 /* Must not be a fragment. */
1830 if (par->fragoff != 0)
1831 return false;
1832
1833 ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph);
1834 if (ic == NULL) {
1835 /* We've been asked to examine this packet, and we
1836 * can't. Hence, no choice but to drop.
1837 */
1838 par->hotdrop = true;
1839 return false;
1840 }
1841
1842 return icmp_type_code_match(icmpinfo->type,
1843 icmpinfo->code[0],
1844 icmpinfo->code[1],
1845 ic->type, ic->code,
1846 !!(icmpinfo->invflags&IPT_ICMP_INV));
1847}
1848
1849static int icmp_checkentry(const struct xt_mtchk_param *par)
1850{
1851 const struct ipt_icmp *icmpinfo = par->matchinfo;
1852
1853 /* Must specify no unknown invflags */
1854 return (icmpinfo->invflags & ~IPT_ICMP_INV) ? -EINVAL : 0;
1855}
1856
1857static struct xt_target ipt_builtin_tg[] __read_mostly = {
1858 {
1859 .name = XT_STANDARD_TARGET,
1860 .targetsize = sizeof(int),
1861 .family = NFPROTO_IPV4,
1862#ifdef CONFIG_COMPAT
1863 .compatsize = sizeof(compat_int_t),
1864 .compat_from_user = compat_standard_from_user,
1865 .compat_to_user = compat_standard_to_user,
1866#endif
1867 },
1868 {
1869 .name = XT_ERROR_TARGET,
1870 .target = ipt_error,
1871 .targetsize = XT_FUNCTION_MAXNAMELEN,
1872 .family = NFPROTO_IPV4,
1873 },
1874};
1875
1876static struct nf_sockopt_ops ipt_sockopts = {
1877 .pf = PF_INET,
1878 .set_optmin = IPT_BASE_CTL,
1879 .set_optmax = IPT_SO_SET_MAX+1,
1880 .set = do_ipt_set_ctl,
1881#ifdef CONFIG_COMPAT
1882 .compat_set = compat_do_ipt_set_ctl,
1883#endif
1884 .get_optmin = IPT_BASE_CTL,
1885 .get_optmax = IPT_SO_GET_MAX+1,
1886 .get = do_ipt_get_ctl,
1887#ifdef CONFIG_COMPAT
1888 .compat_get = compat_do_ipt_get_ctl,
1889#endif
1890 .owner = THIS_MODULE,
1891};
1892
1893static struct xt_match ipt_builtin_mt[] __read_mostly = {
1894 {
1895 .name = "icmp",
1896 .match = icmp_match,
1897 .matchsize = sizeof(struct ipt_icmp),
1898 .checkentry = icmp_checkentry,
1899 .proto = IPPROTO_ICMP,
1900 .family = NFPROTO_IPV4,
1901 .me = THIS_MODULE,
1902 },
1903};
1904
1905static int __net_init ip_tables_net_init(struct net *net)
1906{
1907 return xt_proto_init(net, NFPROTO_IPV4);
1908}
1909
1910static void __net_exit ip_tables_net_exit(struct net *net)
1911{
1912 xt_proto_fini(net, NFPROTO_IPV4);
1913}
1914
1915static struct pernet_operations ip_tables_net_ops = {
1916 .init = ip_tables_net_init,
1917 .exit = ip_tables_net_exit,
1918};
1919
1920static int __init ip_tables_init(void)
1921{
1922 int ret;
1923
1924 ret = register_pernet_subsys(&ip_tables_net_ops);
1925 if (ret < 0)
1926 goto err1;
1927
1928 /* No one else will be downing sem now, so we won't sleep */
1929 ret = xt_register_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
1930 if (ret < 0)
1931 goto err2;
1932 ret = xt_register_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
1933 if (ret < 0)
1934 goto err4;
1935
1936 /* Register setsockopt */
1937 ret = nf_register_sockopt(&ipt_sockopts);
1938 if (ret < 0)
1939 goto err5;
1940
1941 return 0;
1942
1943err5:
1944 xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
1945err4:
1946 xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
1947err2:
1948 unregister_pernet_subsys(&ip_tables_net_ops);
1949err1:
1950 return ret;
1951}
1952
1953static void __exit ip_tables_fini(void)
1954{
1955 nf_unregister_sockopt(&ipt_sockopts);
1956
1957 xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
1958 xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
1959 unregister_pernet_subsys(&ip_tables_net_ops);
1960}
1961
1962EXPORT_SYMBOL(ipt_register_table);
1963EXPORT_SYMBOL(ipt_unregister_table);
1964EXPORT_SYMBOL(ipt_do_table);
1965module_init(ip_tables_init);
1966module_exit(ip_tables_fini);
1967