projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[deliverable/linux.git] / net / ipv4 / netfilter / ip_tables.c
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 <asm/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
34 MODULE_LICENSE("GPL");
35 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
36 MODULE_DESCRIPTION("IPv4 packet filter");
37
38 #ifdef CONFIG_NETFILTER_DEBUG
39 #define IP_NF_ASSERT(x) WARN_ON(!(x))
40 #else
41 #define IP_NF_ASSERT(x)
42 #endif
43
44 void *ipt_alloc_initial_table(const struct xt_table *info)
45 {
46 return xt_alloc_initial_table(ipt, IPT);
47 }
48 EXPORT_SYMBOL_GPL(ipt_alloc_initial_table);
49
50 /* Returns whether matches rule or not. */
51 /* Performance critical - called for every packet */
52 static inline bool
53 ip_packet_match(const struct iphdr *ip,
54 const char *indev,
55 const char *outdev,
56 const struct ipt_ip *ipinfo,
57 int isfrag)
58 {
59 unsigned long ret;
60
61 if (NF_INVF(ipinfo, IPT_INV_SRCIP,
62 (ip->saddr & ipinfo->smsk.s_addr) != ipinfo->src.s_addr) ||
63 NF_INVF(ipinfo, IPT_INV_DSTIP,
64 (ip->daddr & ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr))
65 return false;
66
67 ret = ifname_compare_aligned(indev, ipinfo->iniface, ipinfo->iniface_mask);
68
69 if (NF_INVF(ipinfo, IPT_INV_VIA_IN, ret != 0))
70 return false;
71
72 ret = ifname_compare_aligned(outdev, ipinfo->outiface, ipinfo->outiface_mask);
73
74 if (NF_INVF(ipinfo, IPT_INV_VIA_OUT, ret != 0))
75 return false;
76
77 /* Check specific protocol */
78 if (ipinfo->proto &&
79 NF_INVF(ipinfo, IPT_INV_PROTO, ip->protocol != ipinfo->proto))
80 return false;
81
82 /* If we have a fragment rule but the packet is not a fragment
83 * then we return zero */
84 if (NF_INVF(ipinfo, IPT_INV_FRAG,
85 (ipinfo->flags & IPT_F_FRAG) && !isfrag))
86 return false;
87
88 return true;
89 }
90
91 static bool
92 ip_checkentry(const struct ipt_ip *ip)
93 {
94 if (ip->flags & ~IPT_F_MASK)
95 return false;
96 if (ip->invflags & ~IPT_INV_MASK)
97 return false;
98 return true;
99 }
100
101 static unsigned int
102 ipt_error(struct sk_buff *skb, const struct xt_action_param *par)
103 {
104 net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo);
105
106 return NF_DROP;
107 }
108
109 /* Performance critical */
110 static inline struct ipt_entry *
111 get_entry(const void *base, unsigned int offset)
112 {
113 return (struct ipt_entry *)(base + offset);
114 }
115
116 /* All zeroes == unconditional rule. */
117 /* Mildly perf critical (only if packet tracing is on) */
118 static inline bool unconditional(const struct ipt_entry *e)
119 {
120 static const struct ipt_ip uncond;
121
122 return e->target_offset == sizeof(struct ipt_entry) &&
123 memcmp(&e->ip, &uncond, sizeof(uncond)) == 0;
124 }
125
126 /* for const-correctness */
127 static inline const struct xt_entry_target *
128 ipt_get_target_c(const struct ipt_entry *e)
129 {
130 return ipt_get_target((struct ipt_entry *)e);
131 }
132
133 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
134 static const char *const hooknames[] = {
135 [NF_INET_PRE_ROUTING] = "PREROUTING",
136 [NF_INET_LOCAL_IN] = "INPUT",
137 [NF_INET_FORWARD] = "FORWARD",
138 [NF_INET_LOCAL_OUT] = "OUTPUT",
139 [NF_INET_POST_ROUTING] = "POSTROUTING",
140 };
141
142 enum nf_ip_trace_comments {
143 NF_IP_TRACE_COMMENT_RULE,
144 NF_IP_TRACE_COMMENT_RETURN,
145 NF_IP_TRACE_COMMENT_POLICY,
146 };
147
148 static const char *const comments[] = {
149 [NF_IP_TRACE_COMMENT_RULE] = "rule",
150 [NF_IP_TRACE_COMMENT_RETURN] = "return",
151 [NF_IP_TRACE_COMMENT_POLICY] = "policy",
152 };
153
154 static struct nf_loginfo trace_loginfo = {
155 .type = NF_LOG_TYPE_LOG,
156 .u = {
157 .log = {
158 .level = 4,
159 .logflags = NF_LOG_MASK,
160 },
161 },
162 };
163
164 /* Mildly perf critical (only if packet tracing is on) */
165 static inline int
166 get_chainname_rulenum(const struct ipt_entry *s, const struct ipt_entry *e,
167 const char *hookname, const char **chainname,
168 const char **comment, unsigned int *rulenum)
169 {
170 const struct xt_standard_target *t = (void *)ipt_get_target_c(s);
171
172 if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) {
173 /* Head of user chain: ERROR target with chainname */
174 *chainname = t->target.data;
175 (*rulenum) = 0;
176 } else if (s == e) {
177 (*rulenum)++;
178
179 if (unconditional(s) &&
180 strcmp(t->target.u.kernel.target->name,
181 XT_STANDARD_TARGET) == 0 &&
182 t->verdict < 0) {
183 /* Tail of chains: STANDARD target (return/policy) */
184 *comment = *chainname == hookname
185 ? comments[NF_IP_TRACE_COMMENT_POLICY]
186 : comments[NF_IP_TRACE_COMMENT_RETURN];
187 }
188 return 1;
189 } else
190 (*rulenum)++;
191
192 return 0;
193 }
194
195 static void trace_packet(struct net *net,
196 const struct sk_buff *skb,
197 unsigned int hook,
198 const struct net_device *in,
199 const struct net_device *out,
200 const char *tablename,
201 const struct xt_table_info *private,
202 const struct ipt_entry *e)
203 {
204 const struct ipt_entry *root;
205 const char *hookname, *chainname, *comment;
206 const struct ipt_entry *iter;
207 unsigned int rulenum = 0;
208
209 root = get_entry(private->entries, private->hook_entry[hook]);
210
211 hookname = chainname = hooknames[hook];
212 comment = comments[NF_IP_TRACE_COMMENT_RULE];
213
214 xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
215 if (get_chainname_rulenum(iter, e, hookname,
216 &chainname, &comment, &rulenum) != 0)
217 break;
218
219 nf_log_trace(net, AF_INET, hook, skb, in, out, &trace_loginfo,
220 "TRACE: %s:%s:%s:%u ",
221 tablename, chainname, comment, rulenum);
222 }
223 #endif
224
225 static inline
226 struct ipt_entry *ipt_next_entry(const struct ipt_entry *entry)
227 {
228 return (void *)entry + entry->next_offset;
229 }
230
231 /* Returns one of the generic firewall policies, like NF_ACCEPT. */
232 unsigned int
233 ipt_do_table(struct sk_buff *skb,
234 const struct nf_hook_state *state,
235 struct xt_table *table)
236 {
237 unsigned int hook = state->hook;
238 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
239 const struct iphdr *ip;
240 /* Initializing verdict to NF_DROP keeps gcc happy. */
241 unsigned int verdict = NF_DROP;
242 const char *indev, *outdev;
243 const void *table_base;
244 struct ipt_entry *e, **jumpstack;
245 unsigned int stackidx, cpu;
246 const struct xt_table_info *private;
247 struct xt_action_param acpar;
248 unsigned int addend;
249
250 /* Initialization */
251 stackidx = 0;
252 ip = ip_hdr(skb);
253 indev = state->in ? state->in->name : nulldevname;
254 outdev = state->out ? state->out->name : nulldevname;
255 /* We handle fragments by dealing with the first fragment as
256 * if it was a normal packet. All other fragments are treated
257 * normally, except that they will NEVER match rules that ask
258 * things we don't know, ie. tcp syn flag or ports). If the
259 * rule is also a fragment-specific rule, non-fragments won't
260 * match it. */
261 acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
262 acpar.thoff = ip_hdrlen(skb);
263 acpar.hotdrop = false;
264 acpar.net = state->net;
265 acpar.in = state->in;
266 acpar.out = state->out;
267 acpar.family = NFPROTO_IPV4;
268 acpar.hooknum = hook;
269
270 IP_NF_ASSERT(table->valid_hooks & (1 << hook));
271 local_bh_disable();
272 addend = xt_write_recseq_begin();
273 private = table->private;
274 cpu = smp_processor_id();
275 /*
276 * Ensure we load private-> members after we've fetched the base
277 * pointer.
278 */
279 smp_read_barrier_depends();
280 table_base = private->entries;
281 jumpstack = (struct ipt_entry **)private->jumpstack[cpu];
282
283 /* Switch to alternate jumpstack if we're being invoked via TEE.
284 * TEE issues XT_CONTINUE verdict on original skb so we must not
285 * clobber the jumpstack.
286 *
287 * For recursion via REJECT or SYNPROXY the stack will be clobbered
288 * but it is no problem since absolute verdict is issued by these.
289 */
290 if (static_key_false(&xt_tee_enabled))
291 jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
292
293 e = get_entry(table_base, private->hook_entry[hook]);
294
295 do {
296 const struct xt_entry_target *t;
297 const struct xt_entry_match *ematch;
298 struct xt_counters *counter;
299
300 IP_NF_ASSERT(e);
301 if (!ip_packet_match(ip, indev, outdev,
302 &e->ip, acpar.fragoff)) {
303 no_match:
304 e = ipt_next_entry(e);
305 continue;
306 }
307
308 xt_ematch_foreach(ematch, e) {
309 acpar.match = ematch->u.kernel.match;
310 acpar.matchinfo = ematch->data;
311 if (!acpar.match->match(skb, &acpar))
312 goto no_match;
313 }
314
315 counter = xt_get_this_cpu_counter(&e->counters);
316 ADD_COUNTER(*counter, skb->len, 1);
317
318 t = ipt_get_target(e);
319 IP_NF_ASSERT(t->u.kernel.target);
320
321 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
322 /* The packet is traced: log it */
323 if (unlikely(skb->nf_trace))
324 trace_packet(state->net, skb, hook, state->in,
325 state->out, table->name, private, e);
326 #endif
327 /* Standard target? */
328 if (!t->u.kernel.target->target) {
329 int v;
330
331 v = ((struct xt_standard_target *)t)->verdict;
332 if (v < 0) {
333 /* Pop from stack? */
334 if (v != XT_RETURN) {
335 verdict = (unsigned int)(-v) - 1;
336 break;
337 }
338 if (stackidx == 0) {
339 e = get_entry(table_base,
340 private->underflow[hook]);
341 } else {
342 e = jumpstack[--stackidx];
343 e = ipt_next_entry(e);
344 }
345 continue;
346 }
347 if (table_base + v != ipt_next_entry(e) &&
348 !(e->ip.flags & IPT_F_GOTO))
349 jumpstack[stackidx++] = e;
350
351 e = get_entry(table_base, v);
352 continue;
353 }
354
355 acpar.target = t->u.kernel.target;
356 acpar.targinfo = t->data;
357
358 verdict = t->u.kernel.target->target(skb, &acpar);
359 /* Target might have changed stuff. */
360 ip = ip_hdr(skb);
361 if (verdict == XT_CONTINUE)
362 e = ipt_next_entry(e);
363 else
364 /* Verdict */
365 break;
366 } while (!acpar.hotdrop);
367
368 xt_write_recseq_end(addend);
369 local_bh_enable();
370
371 if (acpar.hotdrop)
372 return NF_DROP;
373 else return verdict;
374 }
375
376 /* Figures out from what hook each rule can be called: returns 0 if
377 there are loops. Puts hook bitmask in comefrom. */
378 static int
379 mark_source_chains(const struct xt_table_info *newinfo,
380 unsigned int valid_hooks, void *entry0,
381 unsigned int *offsets)
382 {
383 unsigned int hook;
384
385 /* No recursion; use packet counter to save back ptrs (reset
386 to 0 as we leave), and comefrom to save source hook bitmask */
387 for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
388 unsigned int pos = newinfo->hook_entry[hook];
389 struct ipt_entry *e = (struct ipt_entry *)(entry0 + pos);
390
391 if (!(valid_hooks & (1 << hook)))
392 continue;
393
394 /* Set initial back pointer. */
395 e->counters.pcnt = pos;
396
397 for (;;) {
398 const struct xt_standard_target *t
399 = (void *)ipt_get_target_c(e);
400 int visited = e->comefrom & (1 << hook);
401
402 if (e->comefrom & (1 << NF_INET_NUMHOOKS))
403 return 0;
404
405 e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
406
407 /* Unconditional return/END. */
408 if ((unconditional(e) &&
409 (strcmp(t->target.u.user.name,
410 XT_STANDARD_TARGET) == 0) &&
411 t->verdict < 0) || visited) {
412 unsigned int oldpos, size;
413
414 if ((strcmp(t->target.u.user.name,
415 XT_STANDARD_TARGET) == 0) &&
416 t->verdict < -NF_MAX_VERDICT - 1)
417 return 0;
418
419 /* Return: backtrack through the last
420 big jump. */
421 do {
422 e->comefrom ^= (1<<NF_INET_NUMHOOKS);
423 oldpos = pos;
424 pos = e->counters.pcnt;
425 e->counters.pcnt = 0;
426
427 /* We're at the start. */
428 if (pos == oldpos)
429 goto next;
430
431 e = (struct ipt_entry *)
432 (entry0 + pos);
433 } while (oldpos == pos + e->next_offset);
434
435 /* Move along one */
436 size = e->next_offset;
437 e = (struct ipt_entry *)
438 (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 e = (struct ipt_entry *)
454 (entry0 + newpos);
455 } else {
456 /* ... this is a fallthru */
457 newpos = pos + e->next_offset;
458 if (newpos >= newinfo->size)
459 return 0;
460 }
461 e = (struct ipt_entry *)
462 (entry0 + newpos);
463 e->counters.pcnt = pos;
464 pos = newpos;
465 }
466 }
467 next: ;
468 }
469 return 1;
470 }
471
472 static void cleanup_match(struct xt_entry_match *m, struct net *net)
473 {
474 struct xt_mtdtor_param par;
475
476 par.net = net;
477 par.match = m->u.kernel.match;
478 par.matchinfo = m->data;
479 par.family = NFPROTO_IPV4;
480 if (par.match->destroy != NULL)
481 par.match->destroy(&par);
482 module_put(par.match->me);
483 }
484
485 static int
486 check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
487 {
488 const struct ipt_ip *ip = par->entryinfo;
489
490 par->match = m->u.kernel.match;
491 par->matchinfo = m->data;
492
493 return xt_check_match(par, m->u.match_size - sizeof(*m),
494 ip->proto, ip->invflags & IPT_INV_PROTO);
495 }
496
497 static int
498 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
499 {
500 struct xt_match *match;
501 int ret;
502
503 match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name,
504 m->u.user.revision);
505 if (IS_ERR(match))
506 return PTR_ERR(match);
507 m->u.kernel.match = match;
508
509 ret = check_match(m, par);
510 if (ret)
511 goto err;
512
513 return 0;
514 err:
515 module_put(m->u.kernel.match->me);
516 return ret;
517 }
518
519 static int check_target(struct ipt_entry *e, struct net *net, const char *name)
520 {
521 struct xt_entry_target *t = ipt_get_target(e);
522 struct xt_tgchk_param par = {
523 .net = net,
524 .table = name,
525 .entryinfo = e,
526 .target = t->u.kernel.target,
527 .targinfo = t->data,
528 .hook_mask = e->comefrom,
529 .family = NFPROTO_IPV4,
530 };
531
532 return xt_check_target(&par, t->u.target_size - sizeof(*t),
533 e->ip.proto, e->ip.invflags & IPT_INV_PROTO);
534 }
535
536 static int
537 find_check_entry(struct ipt_entry *e, struct net *net, const char *name,
538 unsigned int size)
539 {
540 struct xt_entry_target *t;
541 struct xt_target *target;
542 int ret;
543 unsigned int j;
544 struct xt_mtchk_param mtpar;
545 struct xt_entry_match *ematch;
546 unsigned long pcnt;
547
548 pcnt = xt_percpu_counter_alloc();
549 if (IS_ERR_VALUE(pcnt))
550 return -ENOMEM;
551 e->counters.pcnt = pcnt;
552
553 j = 0;
554 mtpar.net = net;
555 mtpar.table = name;
556 mtpar.entryinfo = &e->ip;
557 mtpar.hook_mask = e->comefrom;
558 mtpar.family = NFPROTO_IPV4;
559 xt_ematch_foreach(ematch, e) {
560 ret = find_check_match(ematch, &mtpar);
561 if (ret != 0)
562 goto cleanup_matches;
563 ++j;
564 }
565
566 t = ipt_get_target(e);
567 target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name,
568 t->u.user.revision);
569 if (IS_ERR(target)) {
570 ret = PTR_ERR(target);
571 goto cleanup_matches;
572 }
573 t->u.kernel.target = target;
574
575 ret = check_target(e, net, name);
576 if (ret)
577 goto err;
578
579 return 0;
580 err:
581 module_put(t->u.kernel.target->me);
582 cleanup_matches:
583 xt_ematch_foreach(ematch, e) {
584 if (j-- == 0)
585 break;
586 cleanup_match(ematch, net);
587 }
588
589 xt_percpu_counter_free(e->counters.pcnt);
590
591 return ret;
592 }
593
594 static bool check_underflow(const struct ipt_entry *e)
595 {
596 const struct xt_entry_target *t;
597 unsigned int verdict;
598
599 if (!unconditional(e))
600 return false;
601 t = ipt_get_target_c(e);
602 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
603 return false;
604 verdict = ((struct xt_standard_target *)t)->verdict;
605 verdict = -verdict - 1;
606 return verdict == NF_DROP || verdict == NF_ACCEPT;
607 }
608
609 static int
610 check_entry_size_and_hooks(struct ipt_entry *e,
611 struct xt_table_info *newinfo,
612 const unsigned char *base,
613 const unsigned char *limit,
614 const unsigned int *hook_entries,
615 const unsigned int *underflows,
616 unsigned int valid_hooks)
617 {
618 unsigned int h;
619 int err;
620
621 if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 ||
622 (unsigned char *)e + sizeof(struct ipt_entry) >= limit ||
623 (unsigned char *)e + e->next_offset > limit)
624 return -EINVAL;
625
626 if (e->next_offset
627 < sizeof(struct ipt_entry) + sizeof(struct xt_entry_target))
628 return -EINVAL;
629
630 if (!ip_checkentry(&e->ip))
631 return -EINVAL;
632
633 err = xt_check_entry_offsets(e, e->elems, e->target_offset,
634 e->next_offset);
635 if (err)
636 return err;
637
638 /* Check hooks & underflows */
639 for (h = 0; h < NF_INET_NUMHOOKS; h++) {
640 if (!(valid_hooks & (1 << h)))
641 continue;
642 if ((unsigned char *)e - base == hook_entries[h])
643 newinfo->hook_entry[h] = hook_entries[h];
644 if ((unsigned char *)e - base == underflows[h]) {
645 if (!check_underflow(e))
646 return -EINVAL;
647
648 newinfo->underflow[h] = underflows[h];
649 }
650 }
651
652 /* Clear counters and comefrom */
653 e->counters = ((struct xt_counters) { 0, 0 });
654 e->comefrom = 0;
655 return 0;
656 }
657
658 static void
659 cleanup_entry(struct ipt_entry *e, struct net *net)
660 {
661 struct xt_tgdtor_param par;
662 struct xt_entry_target *t;
663 struct xt_entry_match *ematch;
664
665 /* Cleanup all matches */
666 xt_ematch_foreach(ematch, e)
667 cleanup_match(ematch, net);
668 t = ipt_get_target(e);
669
670 par.net = net;
671 par.target = t->u.kernel.target;
672 par.targinfo = t->data;
673 par.family = NFPROTO_IPV4;
674 if (par.target->destroy != NULL)
675 par.target->destroy(&par);
676 module_put(par.target->me);
677 xt_percpu_counter_free(e->counters.pcnt);
678 }
679
680 /* Checks and translates the user-supplied table segment (held in
681 newinfo) */
682 static int
683 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
684 const struct ipt_replace *repl)
685 {
686 struct ipt_entry *iter;
687 unsigned int *offsets;
688 unsigned int i;
689 int ret = 0;
690
691 newinfo->size = repl->size;
692 newinfo->number = repl->num_entries;
693
694 /* Init all hooks to impossible value. */
695 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
696 newinfo->hook_entry[i] = 0xFFFFFFFF;
697 newinfo->underflow[i] = 0xFFFFFFFF;
698 }
699
700 offsets = xt_alloc_entry_offsets(newinfo->number);
701 if (!offsets)
702 return -ENOMEM;
703 i = 0;
704 /* Walk through entries, checking offsets. */
705 xt_entry_foreach(iter, entry0, newinfo->size) {
706 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
707 entry0 + repl->size,
708 repl->hook_entry,
709 repl->underflow,
710 repl->valid_hooks);
711 if (ret != 0)
712 goto out_free;
713 if (i < repl->num_entries)
714 offsets[i] = (void *)iter - entry0;
715 ++i;
716 if (strcmp(ipt_get_target(iter)->u.user.name,
717 XT_ERROR_TARGET) == 0)
718 ++newinfo->stacksize;
719 }
720
721 ret = -EINVAL;
722 if (i != repl->num_entries)
723 goto out_free;
724
725 /* Check hooks all assigned */
726 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
727 /* Only hooks which are valid */
728 if (!(repl->valid_hooks & (1 << i)))
729 continue;
730 if (newinfo->hook_entry[i] == 0xFFFFFFFF)
731 goto out_free;
732 if (newinfo->underflow[i] == 0xFFFFFFFF)
733 goto out_free;
734 }
735
736 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) {
737 ret = -ELOOP;
738 goto out_free;
739 }
740 kvfree(offsets);
741
742 /* Finally, each sanity check must pass */
743 i = 0;
744 xt_entry_foreach(iter, entry0, newinfo->size) {
745 ret = find_check_entry(iter, net, repl->name, repl->size);
746 if (ret != 0)
747 break;
748 ++i;
749 }
750
751 if (ret != 0) {
752 xt_entry_foreach(iter, entry0, newinfo->size) {
753 if (i-- == 0)
754 break;
755 cleanup_entry(iter, net);
756 }
757 return ret;
758 }
759
760 return ret;
761 out_free:
762 kvfree(offsets);
763 return ret;
764 }
765
766 static void
767 get_counters(const struct xt_table_info *t,
768 struct xt_counters counters[])
769 {
770 struct ipt_entry *iter;
771 unsigned int cpu;
772 unsigned int i;
773
774 for_each_possible_cpu(cpu) {
775 seqcount_t *s = &per_cpu(xt_recseq, cpu);
776
777 i = 0;
778 xt_entry_foreach(iter, t->entries, t->size) {
779 struct xt_counters *tmp;
780 u64 bcnt, pcnt;
781 unsigned int start;
782
783 tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
784 do {
785 start = read_seqcount_begin(s);
786 bcnt = tmp->bcnt;
787 pcnt = tmp->pcnt;
788 } while (read_seqcount_retry(s, start));
789
790 ADD_COUNTER(counters[i], bcnt, pcnt);
791 ++i; /* macro does multi eval of i */
792 }
793 }
794 }
795
796 static struct xt_counters *alloc_counters(const struct xt_table *table)
797 {
798 unsigned int countersize;
799 struct xt_counters *counters;
800 const struct xt_table_info *private = table->private;
801
802 /* We need atomic snapshot of counters: rest doesn't change
803 (other than comefrom, which userspace doesn't care
804 about). */
805 countersize = sizeof(struct xt_counters) * private->number;
806 counters = vzalloc(countersize);
807
808 if (counters == NULL)
809 return ERR_PTR(-ENOMEM);
810
811 get_counters(private, counters);
812
813 return counters;
814 }
815
816 static int
817 copy_entries_to_user(unsigned int total_size,
818 const struct xt_table *table,
819 void __user *userptr)
820 {
821 unsigned int off, num;
822 const struct ipt_entry *e;
823 struct xt_counters *counters;
824 const struct xt_table_info *private = table->private;
825 int ret = 0;
826 const void *loc_cpu_entry;
827
828 counters = alloc_counters(table);
829 if (IS_ERR(counters))
830 return PTR_ERR(counters);
831
832 loc_cpu_entry = private->entries;
833 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
834 ret = -EFAULT;
835 goto free_counters;
836 }
837
838 /* FIXME: use iterator macros --RR */
839 /* ... then go back and fix counters and names */
840 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
841 unsigned int i;
842 const struct xt_entry_match *m;
843 const struct xt_entry_target *t;
844
845 e = (struct ipt_entry *)(loc_cpu_entry + off);
846 if (copy_to_user(userptr + off
847 + offsetof(struct ipt_entry, counters),
848 &counters[num],
849 sizeof(counters[num])) != 0) {
850 ret = -EFAULT;
851 goto free_counters;
852 }
853
854 for (i = sizeof(struct ipt_entry);
855 i < e->target_offset;
856 i += m->u.match_size) {
857 m = (void *)e + i;
858
859 if (copy_to_user(userptr + off + i
860 + offsetof(struct xt_entry_match,
861 u.user.name),
862 m->u.kernel.match->name,
863 strlen(m->u.kernel.match->name)+1)
864 != 0) {
865 ret = -EFAULT;
866 goto free_counters;
867 }
868 }
869
870 t = ipt_get_target_c(e);
871 if (copy_to_user(userptr + off + e->target_offset
872 + offsetof(struct xt_entry_target,
873 u.user.name),
874 t->u.kernel.target->name,
875 strlen(t->u.kernel.target->name)+1) != 0) {
876 ret = -EFAULT;
877 goto free_counters;
878 }
879 }
880
881 free_counters:
882 vfree(counters);
883 return ret;
884 }
885
886 #ifdef CONFIG_COMPAT
887 static void compat_standard_from_user(void *dst, const void *src)
888 {
889 int v = *(compat_int_t *)src;
890
891 if (v > 0)
892 v += xt_compat_calc_jump(AF_INET, v);
893 memcpy(dst, &v, sizeof(v));
894 }
895
896 static int compat_standard_to_user(void __user *dst, const void *src)
897 {
898 compat_int_t cv = *(int *)src;
899
900 if (cv > 0)
901 cv -= xt_compat_calc_jump(AF_INET, cv);
902 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
903 }
904
905 static int compat_calc_entry(const struct ipt_entry *e,
906 const struct xt_table_info *info,
907 const void *base, struct xt_table_info *newinfo)
908 {
909 const struct xt_entry_match *ematch;
910 const struct xt_entry_target *t;
911 unsigned int entry_offset;
912 int off, i, ret;
913
914 off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
915 entry_offset = (void *)e - base;
916 xt_ematch_foreach(ematch, e)
917 off += xt_compat_match_offset(ematch->u.kernel.match);
918 t = ipt_get_target_c(e);
919 off += xt_compat_target_offset(t->u.kernel.target);
920 newinfo->size -= off;
921 ret = xt_compat_add_offset(AF_INET, entry_offset, off);
922 if (ret)
923 return ret;
924
925 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
926 if (info->hook_entry[i] &&
927 (e < (struct ipt_entry *)(base + info->hook_entry[i])))
928 newinfo->hook_entry[i] -= off;
929 if (info->underflow[i] &&
930 (e < (struct ipt_entry *)(base + info->underflow[i])))
931 newinfo->underflow[i] -= off;
932 }
933 return 0;
934 }
935
936 static int compat_table_info(const struct xt_table_info *info,
937 struct xt_table_info *newinfo)
938 {
939 struct ipt_entry *iter;
940 const void *loc_cpu_entry;
941 int ret;
942
943 if (!newinfo || !info)
944 return -EINVAL;
945
946 /* we dont care about newinfo->entries */
947 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
948 newinfo->initial_entries = 0;
949 loc_cpu_entry = info->entries;
950 xt_compat_init_offsets(AF_INET, info->number);
951 xt_entry_foreach(iter, loc_cpu_entry, info->size) {
952 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
953 if (ret != 0)
954 return ret;
955 }
956 return 0;
957 }
958 #endif
959
960 static int get_info(struct net *net, void __user *user,
961 const int *len, int compat)
962 {
963 char name[XT_TABLE_MAXNAMELEN];
964 struct xt_table *t;
965 int ret;
966
967 if (*len != sizeof(struct ipt_getinfo))
968 return -EINVAL;
969
970 if (copy_from_user(name, user, sizeof(name)) != 0)
971 return -EFAULT;
972
973 name[XT_TABLE_MAXNAMELEN-1] = '\0';
974 #ifdef CONFIG_COMPAT
975 if (compat)
976 xt_compat_lock(AF_INET);
977 #endif
978 t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
979 "iptable_%s", name);
980 if (!IS_ERR_OR_NULL(t)) {
981 struct ipt_getinfo info;
982 const struct xt_table_info *private = t->private;
983 #ifdef CONFIG_COMPAT
984 struct xt_table_info tmp;
985
986 if (compat) {
987 ret = compat_table_info(private, &tmp);
988 xt_compat_flush_offsets(AF_INET);
989 private = &tmp;
990 }
991 #endif
992 memset(&info, 0, sizeof(info));
993 info.valid_hooks = t->valid_hooks;
994 memcpy(info.hook_entry, private->hook_entry,
995 sizeof(info.hook_entry));
996 memcpy(info.underflow, private->underflow,
997 sizeof(info.underflow));
998 info.num_entries = private->number;
999 info.size = private->size;
1000 strcpy(info.name, name);
1001
1002 if (copy_to_user(user, &info, *len) != 0)
1003 ret = -EFAULT;
1004 else
1005 ret = 0;
1006
1007 xt_table_unlock(t);
1008 module_put(t->me);
1009 } else
1010 ret = t ? PTR_ERR(t) : -ENOENT;
1011 #ifdef CONFIG_COMPAT
1012 if (compat)
1013 xt_compat_unlock(AF_INET);
1014 #endif
1015 return ret;
1016 }
1017
1018 static int
1019 get_entries(struct net *net, struct ipt_get_entries __user *uptr,
1020 const int *len)
1021 {
1022 int ret;
1023 struct ipt_get_entries get;
1024 struct xt_table *t;
1025
1026 if (*len < sizeof(get))
1027 return -EINVAL;
1028 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1029 return -EFAULT;
1030 if (*len != sizeof(struct ipt_get_entries) + get.size)
1031 return -EINVAL;
1032 get.name[sizeof(get.name) - 1] = '\0';
1033
1034 t = xt_find_table_lock(net, AF_INET, get.name);
1035 if (!IS_ERR_OR_NULL(t)) {
1036 const struct xt_table_info *private = t->private;
1037 if (get.size == private->size)
1038 ret = copy_entries_to_user(private->size,
1039 t, uptr->entrytable);
1040 else
1041 ret = -EAGAIN;
1042
1043 module_put(t->me);
1044 xt_table_unlock(t);
1045 } else
1046 ret = t ? PTR_ERR(t) : -ENOENT;
1047
1048 return ret;
1049 }
1050
1051 static int
1052 __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
1053 struct xt_table_info *newinfo, unsigned int num_counters,
1054 void __user *counters_ptr)
1055 {
1056 int ret;
1057 struct xt_table *t;
1058 struct xt_table_info *oldinfo;
1059 struct xt_counters *counters;
1060 struct ipt_entry *iter;
1061
1062 ret = 0;
1063 counters = vzalloc(num_counters * sizeof(struct xt_counters));
1064 if (!counters) {
1065 ret = -ENOMEM;
1066 goto out;
1067 }
1068
1069 t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
1070 "iptable_%s", name);
1071 if (IS_ERR_OR_NULL(t)) {
1072 ret = t ? PTR_ERR(t) : -ENOENT;
1073 goto free_newinfo_counters_untrans;
1074 }
1075
1076 /* You lied! */
1077 if (valid_hooks != t->valid_hooks) {
1078 ret = -EINVAL;
1079 goto put_module;
1080 }
1081
1082 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1083 if (!oldinfo)
1084 goto put_module;
1085
1086 /* Update module usage count based on number of rules */
1087 if ((oldinfo->number > oldinfo->initial_entries) ||
1088 (newinfo->number <= oldinfo->initial_entries))
1089 module_put(t->me);
1090 if ((oldinfo->number > oldinfo->initial_entries) &&
1091 (newinfo->number <= oldinfo->initial_entries))
1092 module_put(t->me);
1093
1094 /* Get the old counters, and synchronize with replace */
1095 get_counters(oldinfo, counters);
1096
1097 /* Decrease module usage counts and free resource */
1098 xt_entry_foreach(iter, oldinfo->entries, oldinfo->size)
1099 cleanup_entry(iter, net);
1100
1101 xt_free_table_info(oldinfo);
1102 if (copy_to_user(counters_ptr, counters,
1103 sizeof(struct xt_counters) * num_counters) != 0) {
1104 /* Silent error, can't fail, new table is already in place */
1105 net_warn_ratelimited("iptables: counters copy to user failed while replacing table\n");
1106 }
1107 vfree(counters);
1108 xt_table_unlock(t);
1109 return ret;
1110
1111 put_module:
1112 module_put(t->me);
1113 xt_table_unlock(t);
1114 free_newinfo_counters_untrans:
1115 vfree(counters);
1116 out:
1117 return ret;
1118 }
1119
1120 static int
1121 do_replace(struct net *net, const void __user *user, unsigned int len)
1122 {
1123 int ret;
1124 struct ipt_replace tmp;
1125 struct xt_table_info *newinfo;
1126 void *loc_cpu_entry;
1127 struct ipt_entry *iter;
1128
1129 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1130 return -EFAULT;
1131
1132 /* overflow check */
1133 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1134 return -ENOMEM;
1135 if (tmp.num_counters == 0)
1136 return -EINVAL;
1137
1138 tmp.name[sizeof(tmp.name)-1] = 0;
1139
1140 newinfo = xt_alloc_table_info(tmp.size);
1141 if (!newinfo)
1142 return -ENOMEM;
1143
1144 loc_cpu_entry = newinfo->entries;
1145 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1146 tmp.size) != 0) {
1147 ret = -EFAULT;
1148 goto free_newinfo;
1149 }
1150
1151 ret = translate_table(net, newinfo, loc_cpu_entry, &tmp);
1152 if (ret != 0)
1153 goto free_newinfo;
1154
1155 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1156 tmp.num_counters, tmp.counters);
1157 if (ret)
1158 goto free_newinfo_untrans;
1159 return 0;
1160
1161 free_newinfo_untrans:
1162 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1163 cleanup_entry(iter, net);
1164 free_newinfo:
1165 xt_free_table_info(newinfo);
1166 return ret;
1167 }
1168
1169 static int
1170 do_add_counters(struct net *net, const void __user *user,
1171 unsigned int len, int compat)
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 ipt_entry *iter;
1180 unsigned int addend;
1181
1182 paddc = xt_copy_counters_from_user(user, len, &tmp, compat);
1183 if (IS_ERR(paddc))
1184 return PTR_ERR(paddc);
1185
1186 t = xt_find_table_lock(net, AF_INET, tmp.name);
1187 if (IS_ERR_OR_NULL(t)) {
1188 ret = t ? PTR_ERR(t) : -ENOENT;
1189 goto free;
1190 }
1191
1192 local_bh_disable();
1193 private = t->private;
1194 if (private->number != tmp.num_counters) {
1195 ret = -EINVAL;
1196 goto unlock_up_free;
1197 }
1198
1199 i = 0;
1200 addend = xt_write_recseq_begin();
1201 xt_entry_foreach(iter, private->entries, private->size) {
1202 struct xt_counters *tmp;
1203
1204 tmp = xt_get_this_cpu_counter(&iter->counters);
1205 ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt);
1206 ++i;
1207 }
1208 xt_write_recseq_end(addend);
1209 unlock_up_free:
1210 local_bh_enable();
1211 xt_table_unlock(t);
1212 module_put(t->me);
1213 free:
1214 vfree(paddc);
1215
1216 return ret;
1217 }
1218
1219 #ifdef CONFIG_COMPAT
1220 struct compat_ipt_replace {
1221 char name[XT_TABLE_MAXNAMELEN];
1222 u32 valid_hooks;
1223 u32 num_entries;
1224 u32 size;
1225 u32 hook_entry[NF_INET_NUMHOOKS];
1226 u32 underflow[NF_INET_NUMHOOKS];
1227 u32 num_counters;
1228 compat_uptr_t counters; /* struct xt_counters * */
1229 struct compat_ipt_entry entries[0];
1230 };
1231
1232 static int
1233 compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr,
1234 unsigned int *size, struct xt_counters *counters,
1235 unsigned int i)
1236 {
1237 struct xt_entry_target *t;
1238 struct compat_ipt_entry __user *ce;
1239 u_int16_t target_offset, next_offset;
1240 compat_uint_t origsize;
1241 const struct xt_entry_match *ematch;
1242 int ret = 0;
1243
1244 origsize = *size;
1245 ce = (struct compat_ipt_entry __user *)*dstptr;
1246 if (copy_to_user(ce, e, sizeof(struct ipt_entry)) != 0 ||
1247 copy_to_user(&ce->counters, &counters[i],
1248 sizeof(counters[i])) != 0)
1249 return -EFAULT;
1250
1251 *dstptr += sizeof(struct compat_ipt_entry);
1252 *size -= sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1253
1254 xt_ematch_foreach(ematch, e) {
1255 ret = xt_compat_match_to_user(ematch, dstptr, size);
1256 if (ret != 0)
1257 return ret;
1258 }
1259 target_offset = e->target_offset - (origsize - *size);
1260 t = ipt_get_target(e);
1261 ret = xt_compat_target_to_user(t, dstptr, size);
1262 if (ret)
1263 return ret;
1264 next_offset = e->next_offset - (origsize - *size);
1265 if (put_user(target_offset, &ce->target_offset) != 0 ||
1266 put_user(next_offset, &ce->next_offset) != 0)
1267 return -EFAULT;
1268 return 0;
1269 }
1270
1271 static int
1272 compat_find_calc_match(struct xt_entry_match *m,
1273 const struct ipt_ip *ip,
1274 int *size)
1275 {
1276 struct xt_match *match;
1277
1278 match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name,
1279 m->u.user.revision);
1280 if (IS_ERR(match))
1281 return PTR_ERR(match);
1282
1283 m->u.kernel.match = match;
1284 *size += xt_compat_match_offset(match);
1285 return 0;
1286 }
1287
1288 static void compat_release_entry(struct compat_ipt_entry *e)
1289 {
1290 struct xt_entry_target *t;
1291 struct xt_entry_match *ematch;
1292
1293 /* Cleanup all matches */
1294 xt_ematch_foreach(ematch, e)
1295 module_put(ematch->u.kernel.match->me);
1296 t = compat_ipt_get_target(e);
1297 module_put(t->u.kernel.target->me);
1298 }
1299
1300 static int
1301 check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
1302 struct xt_table_info *newinfo,
1303 unsigned int *size,
1304 const unsigned char *base,
1305 const unsigned char *limit)
1306 {
1307 struct xt_entry_match *ematch;
1308 struct xt_entry_target *t;
1309 struct xt_target *target;
1310 unsigned int entry_offset;
1311 unsigned int j;
1312 int ret, off;
1313
1314 if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0 ||
1315 (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit ||
1316 (unsigned char *)e + e->next_offset > limit)
1317 return -EINVAL;
1318
1319 if (e->next_offset < sizeof(struct compat_ipt_entry) +
1320 sizeof(struct compat_xt_entry_target))
1321 return -EINVAL;
1322
1323 if (!ip_checkentry(&e->ip))
1324 return -EINVAL;
1325
1326 ret = xt_compat_check_entry_offsets(e, e->elems,
1327 e->target_offset, e->next_offset);
1328 if (ret)
1329 return ret;
1330
1331 off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1332 entry_offset = (void *)e - (void *)base;
1333 j = 0;
1334 xt_ematch_foreach(ematch, e) {
1335 ret = compat_find_calc_match(ematch, &e->ip, &off);
1336 if (ret != 0)
1337 goto release_matches;
1338 ++j;
1339 }
1340
1341 t = compat_ipt_get_target(e);
1342 target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name,
1343 t->u.user.revision);
1344 if (IS_ERR(target)) {
1345 ret = PTR_ERR(target);
1346 goto release_matches;
1347 }
1348 t->u.kernel.target = target;
1349
1350 off += xt_compat_target_offset(target);
1351 *size += off;
1352 ret = xt_compat_add_offset(AF_INET, entry_offset, off);
1353 if (ret)
1354 goto out;
1355
1356 return 0;
1357
1358 out:
1359 module_put(t->u.kernel.target->me);
1360 release_matches:
1361 xt_ematch_foreach(ematch, e) {
1362 if (j-- == 0)
1363 break;
1364 module_put(ematch->u.kernel.match->me);
1365 }
1366 return ret;
1367 }
1368
1369 static void
1370 compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
1371 unsigned int *size,
1372 struct xt_table_info *newinfo, unsigned char *base)
1373 {
1374 struct xt_entry_target *t;
1375 struct xt_target *target;
1376 struct ipt_entry *de;
1377 unsigned int origsize;
1378 int h;
1379 struct xt_entry_match *ematch;
1380
1381 origsize = *size;
1382 de = (struct ipt_entry *)*dstptr;
1383 memcpy(de, e, sizeof(struct ipt_entry));
1384 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1385
1386 *dstptr += sizeof(struct ipt_entry);
1387 *size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1388
1389 xt_ematch_foreach(ematch, e)
1390 xt_compat_match_from_user(ematch, dstptr, size);
1391
1392 de->target_offset = e->target_offset - (origsize - *size);
1393 t = compat_ipt_get_target(e);
1394 target = t->u.kernel.target;
1395 xt_compat_target_from_user(t, dstptr, size);
1396
1397 de->next_offset = e->next_offset - (origsize - *size);
1398
1399 for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1400 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1401 newinfo->hook_entry[h] -= origsize - *size;
1402 if ((unsigned char *)de - base < newinfo->underflow[h])
1403 newinfo->underflow[h] -= origsize - *size;
1404 }
1405 }
1406
1407 static int
1408 translate_compat_table(struct net *net,
1409 struct xt_table_info **pinfo,
1410 void **pentry0,
1411 const struct compat_ipt_replace *compatr)
1412 {
1413 unsigned int i, j;
1414 struct xt_table_info *newinfo, *info;
1415 void *pos, *entry0, *entry1;
1416 struct compat_ipt_entry *iter0;
1417 struct ipt_replace repl;
1418 unsigned int size;
1419 int ret;
1420
1421 info = *pinfo;
1422 entry0 = *pentry0;
1423 size = compatr->size;
1424 info->number = compatr->num_entries;
1425
1426 j = 0;
1427 xt_compat_lock(AF_INET);
1428 xt_compat_init_offsets(AF_INET, compatr->num_entries);
1429 /* Walk through entries, checking offsets. */
1430 xt_entry_foreach(iter0, entry0, compatr->size) {
1431 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1432 entry0,
1433 entry0 + compatr->size);
1434 if (ret != 0)
1435 goto out_unlock;
1436 ++j;
1437 }
1438
1439 ret = -EINVAL;
1440 if (j != compatr->num_entries)
1441 goto out_unlock;
1442
1443 ret = -ENOMEM;
1444 newinfo = xt_alloc_table_info(size);
1445 if (!newinfo)
1446 goto out_unlock;
1447
1448 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 * entry1/newinfo contains a 64bit ruleset that looks exactly as
1462 * generated by 64bit userspace.
1463 *
1464 * Call standard translate_table() to validate all hook_entrys,
1465 * underflows, check for loops, etc.
1466 */
1467 xt_compat_flush_offsets(AF_INET);
1468 xt_compat_unlock(AF_INET);
1469
1470 memcpy(&repl, compatr, sizeof(*compatr));
1471
1472 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1473 repl.hook_entry[i] = newinfo->hook_entry[i];
1474 repl.underflow[i] = newinfo->underflow[i];
1475 }
1476
1477 repl.num_counters = 0;
1478 repl.counters = NULL;
1479 repl.size = newinfo->size;
1480 ret = translate_table(net, newinfo, entry1, &repl);
1481 if (ret)
1482 goto free_newinfo;
1483
1484 *pinfo = newinfo;
1485 *pentry0 = entry1;
1486 xt_free_table_info(info);
1487 return 0;
1488
1489 free_newinfo:
1490 xt_free_table_info(newinfo);
1491 return ret;
1492 out_unlock:
1493 xt_compat_flush_offsets(AF_INET);
1494 xt_compat_unlock(AF_INET);
1495 xt_entry_foreach(iter0, entry0, compatr->size) {
1496 if (j-- == 0)
1497 break;
1498 compat_release_entry(iter0);
1499 }
1500 return ret;
1501 }
1502
1503 static int
1504 compat_do_replace(struct net *net, void __user *user, unsigned int len)
1505 {
1506 int ret;
1507 struct compat_ipt_replace tmp;
1508 struct xt_table_info *newinfo;
1509 void *loc_cpu_entry;
1510 struct ipt_entry *iter;
1511
1512 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1513 return -EFAULT;
1514
1515 /* overflow check */
1516 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1517 return -ENOMEM;
1518 if (tmp.num_counters == 0)
1519 return -EINVAL;
1520
1521 tmp.name[sizeof(tmp.name)-1] = 0;
1522
1523 newinfo = xt_alloc_table_info(tmp.size);
1524 if (!newinfo)
1525 return -ENOMEM;
1526
1527 loc_cpu_entry = newinfo->entries;
1528 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1529 tmp.size) != 0) {
1530 ret = -EFAULT;
1531 goto free_newinfo;
1532 }
1533
1534 ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp);
1535 if (ret != 0)
1536 goto free_newinfo;
1537
1538 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1539 tmp.num_counters, compat_ptr(tmp.counters));
1540 if (ret)
1541 goto free_newinfo_untrans;
1542 return 0;
1543
1544 free_newinfo_untrans:
1545 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1546 cleanup_entry(iter, net);
1547 free_newinfo:
1548 xt_free_table_info(newinfo);
1549 return ret;
1550 }
1551
1552 static int
1553 compat_do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user,
1554 unsigned int len)
1555 {
1556 int ret;
1557
1558 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1559 return -EPERM;
1560
1561 switch (cmd) {
1562 case IPT_SO_SET_REPLACE:
1563 ret = compat_do_replace(sock_net(sk), user, len);
1564 break;
1565
1566 case IPT_SO_SET_ADD_COUNTERS:
1567 ret = do_add_counters(sock_net(sk), user, len, 1);
1568 break;
1569
1570 default:
1571 ret = -EINVAL;
1572 }
1573
1574 return ret;
1575 }
1576
1577 struct compat_ipt_get_entries {
1578 char name[XT_TABLE_MAXNAMELEN];
1579 compat_uint_t size;
1580 struct compat_ipt_entry entrytable[0];
1581 };
1582
1583 static int
1584 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
1585 void __user *userptr)
1586 {
1587 struct xt_counters *counters;
1588 const struct xt_table_info *private = table->private;
1589 void __user *pos;
1590 unsigned int size;
1591 int ret = 0;
1592 unsigned int i = 0;
1593 struct ipt_entry *iter;
1594
1595 counters = alloc_counters(table);
1596 if (IS_ERR(counters))
1597 return PTR_ERR(counters);
1598
1599 pos = userptr;
1600 size = total_size;
1601 xt_entry_foreach(iter, private->entries, total_size) {
1602 ret = compat_copy_entry_to_user(iter, &pos,
1603 &size, counters, i++);
1604 if (ret != 0)
1605 break;
1606 }
1607
1608 vfree(counters);
1609 return ret;
1610 }
1611
1612 static int
1613 compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr,
1614 int *len)
1615 {
1616 int ret;
1617 struct compat_ipt_get_entries get;
1618 struct xt_table *t;
1619
1620 if (*len < sizeof(get))
1621 return -EINVAL;
1622
1623 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1624 return -EFAULT;
1625
1626 if (*len != sizeof(struct compat_ipt_get_entries) + get.size)
1627 return -EINVAL;
1628
1629 get.name[sizeof(get.name) - 1] = '\0';
1630
1631 xt_compat_lock(AF_INET);
1632 t = xt_find_table_lock(net, AF_INET, get.name);
1633 if (!IS_ERR_OR_NULL(t)) {
1634 const struct xt_table_info *private = t->private;
1635 struct xt_table_info info;
1636 ret = compat_table_info(private, &info);
1637 if (!ret && get.size == info.size)
1638 ret = compat_copy_entries_to_user(private->size,
1639 t, uptr->entrytable);
1640 else if (!ret)
1641 ret = -EAGAIN;
1642
1643 xt_compat_flush_offsets(AF_INET);
1644 module_put(t->me);
1645 xt_table_unlock(t);
1646 } else
1647 ret = t ? PTR_ERR(t) : -ENOENT;
1648
1649 xt_compat_unlock(AF_INET);
1650 return ret;
1651 }
1652
1653 static int do_ipt_get_ctl(struct sock *, int, void __user *, int *);
1654
1655 static int
1656 compat_do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1657 {
1658 int ret;
1659
1660 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1661 return -EPERM;
1662
1663 switch (cmd) {
1664 case IPT_SO_GET_INFO:
1665 ret = get_info(sock_net(sk), user, len, 1);
1666 break;
1667 case IPT_SO_GET_ENTRIES:
1668 ret = compat_get_entries(sock_net(sk), user, len);
1669 break;
1670 default:
1671 ret = do_ipt_get_ctl(sk, cmd, user, len);
1672 }
1673 return ret;
1674 }
1675 #endif
1676
1677 static int
1678 do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1679 {
1680 int ret;
1681
1682 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1683 return -EPERM;
1684
1685 switch (cmd) {
1686 case IPT_SO_SET_REPLACE:
1687 ret = do_replace(sock_net(sk), user, len);
1688 break;
1689
1690 case IPT_SO_SET_ADD_COUNTERS:
1691 ret = do_add_counters(sock_net(sk), user, len, 0);
1692 break;
1693
1694 default:
1695 ret = -EINVAL;
1696 }
1697
1698 return ret;
1699 }
1700
1701 static int
1702 do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1703 {
1704 int ret;
1705
1706 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1707 return -EPERM;
1708
1709 switch (cmd) {
1710 case IPT_SO_GET_INFO:
1711 ret = get_info(sock_net(sk), user, len, 0);
1712 break;
1713
1714 case IPT_SO_GET_ENTRIES:
1715 ret = get_entries(sock_net(sk), user, len);
1716 break;
1717
1718 case IPT_SO_GET_REVISION_MATCH:
1719 case IPT_SO_GET_REVISION_TARGET: {
1720 struct xt_get_revision rev;
1721 int target;
1722
1723 if (*len != sizeof(rev)) {
1724 ret = -EINVAL;
1725 break;
1726 }
1727 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1728 ret = -EFAULT;
1729 break;
1730 }
1731 rev.name[sizeof(rev.name)-1] = 0;
1732
1733 if (cmd == IPT_SO_GET_REVISION_TARGET)
1734 target = 1;
1735 else
1736 target = 0;
1737
1738 try_then_request_module(xt_find_revision(AF_INET, rev.name,
1739 rev.revision,
1740 target, &ret),
1741 "ipt_%s", rev.name);
1742 break;
1743 }
1744
1745 default:
1746 ret = -EINVAL;
1747 }
1748
1749 return ret;
1750 }
1751
1752 static void __ipt_unregister_table(struct net *net, struct xt_table *table)
1753 {
1754 struct xt_table_info *private;
1755 void *loc_cpu_entry;
1756 struct module *table_owner = table->me;
1757 struct ipt_entry *iter;
1758
1759 private = xt_unregister_table(table);
1760
1761 /* Decrease module usage counts and free resources */
1762 loc_cpu_entry = private->entries;
1763 xt_entry_foreach(iter, loc_cpu_entry, private->size)
1764 cleanup_entry(iter, net);
1765 if (private->number > private->initial_entries)
1766 module_put(table_owner);
1767 xt_free_table_info(private);
1768 }
1769
1770 int ipt_register_table(struct net *net, const struct xt_table *table,
1771 const struct ipt_replace *repl,
1772 const struct nf_hook_ops *ops, struct xt_table **res)
1773 {
1774 int ret;
1775 struct xt_table_info *newinfo;
1776 struct xt_table_info bootstrap = {0};
1777 void *loc_cpu_entry;
1778 struct xt_table *new_table;
1779
1780 newinfo = xt_alloc_table_info(repl->size);
1781 if (!newinfo)
1782 return -ENOMEM;
1783
1784 loc_cpu_entry = newinfo->entries;
1785 memcpy(loc_cpu_entry, repl->entries, repl->size);
1786
1787 ret = translate_table(net, newinfo, loc_cpu_entry, repl);
1788 if (ret != 0)
1789 goto out_free;
1790
1791 new_table = xt_register_table(net, table, &bootstrap, newinfo);
1792 if (IS_ERR(new_table)) {
1793 ret = PTR_ERR(new_table);
1794 goto out_free;
1795 }
1796
1797 /* set res now, will see skbs right after nf_register_net_hooks */
1798 WRITE_ONCE(*res, new_table);
1799
1800 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
1801 if (ret != 0) {
1802 __ipt_unregister_table(net, new_table);
1803 *res = NULL;
1804 }
1805
1806 return ret;
1807
1808 out_free:
1809 xt_free_table_info(newinfo);
1810 return ret;
1811 }
1812
1813 void ipt_unregister_table(struct net *net, struct xt_table *table,
1814 const struct nf_hook_ops *ops)
1815 {
1816 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
1817 __ipt_unregister_table(net, table);
1818 }
1819
1820 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
1821 static inline bool
1822 icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
1823 u_int8_t type, u_int8_t code,
1824 bool invert)
1825 {
1826 return ((test_type == 0xFF) ||
1827 (type == test_type && code >= min_code && code <= max_code))
1828 ^ invert;
1829 }
1830
1831 static bool
1832 icmp_match(const struct sk_buff *skb, struct xt_action_param *par)
1833 {
1834 const struct icmphdr *ic;
1835 struct icmphdr _icmph;
1836 const struct ipt_icmp *icmpinfo = par->matchinfo;
1837
1838 /* Must not be a fragment. */
1839 if (par->fragoff != 0)
1840 return false;
1841
1842 ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph);
1843 if (ic == NULL) {
1844 /* We've been asked to examine this packet, and we
1845 * can't. Hence, no choice but to drop.
1846 */
1847 par->hotdrop = true;
1848 return false;
1849 }
1850
1851 return icmp_type_code_match(icmpinfo->type,
1852 icmpinfo->code[0],
1853 icmpinfo->code[1],
1854 ic->type, ic->code,
1855 !!(icmpinfo->invflags&IPT_ICMP_INV));
1856 }
1857
1858 static int icmp_checkentry(const struct xt_mtchk_param *par)
1859 {
1860 const struct ipt_icmp *icmpinfo = par->matchinfo;
1861
1862 /* Must specify no unknown invflags */
1863 return (icmpinfo->invflags & ~IPT_ICMP_INV) ? -EINVAL : 0;
1864 }
1865
1866 static struct xt_target ipt_builtin_tg[] __read_mostly = {
1867 {
1868 .name = XT_STANDARD_TARGET,
1869 .targetsize = sizeof(int),
1870 .family = NFPROTO_IPV4,
1871 #ifdef CONFIG_COMPAT
1872 .compatsize = sizeof(compat_int_t),
1873 .compat_from_user = compat_standard_from_user,
1874 .compat_to_user = compat_standard_to_user,
1875 #endif
1876 },
1877 {
1878 .name = XT_ERROR_TARGET,
1879 .target = ipt_error,
1880 .targetsize = XT_FUNCTION_MAXNAMELEN,
1881 .family = NFPROTO_IPV4,
1882 },
1883 };
1884
1885 static struct nf_sockopt_ops ipt_sockopts = {
1886 .pf = PF_INET,
1887 .set_optmin = IPT_BASE_CTL,
1888 .set_optmax = IPT_SO_SET_MAX+1,
1889 .set = do_ipt_set_ctl,
1890 #ifdef CONFIG_COMPAT
1891 .compat_set = compat_do_ipt_set_ctl,
1892 #endif
1893 .get_optmin = IPT_BASE_CTL,
1894 .get_optmax = IPT_SO_GET_MAX+1,
1895 .get = do_ipt_get_ctl,
1896 #ifdef CONFIG_COMPAT
1897 .compat_get = compat_do_ipt_get_ctl,
1898 #endif
1899 .owner = THIS_MODULE,
1900 };
1901
1902 static struct xt_match ipt_builtin_mt[] __read_mostly = {
1903 {
1904 .name = "icmp",
1905 .match = icmp_match,
1906 .matchsize = sizeof(struct ipt_icmp),
1907 .checkentry = icmp_checkentry,
1908 .proto = IPPROTO_ICMP,
1909 .family = NFPROTO_IPV4,
1910 },
1911 };
1912
1913 static int __net_init ip_tables_net_init(struct net *net)
1914 {
1915 return xt_proto_init(net, NFPROTO_IPV4);
1916 }
1917
1918 static void __net_exit ip_tables_net_exit(struct net *net)
1919 {
1920 xt_proto_fini(net, NFPROTO_IPV4);
1921 }
1922
1923 static struct pernet_operations ip_tables_net_ops = {
1924 .init = ip_tables_net_init,
1925 .exit = ip_tables_net_exit,
1926 };
1927
1928 static int __init ip_tables_init(void)
1929 {
1930 int ret;
1931
1932 ret = register_pernet_subsys(&ip_tables_net_ops);
1933 if (ret < 0)
1934 goto err1;
1935
1936 /* No one else will be downing sem now, so we won't sleep */
1937 ret = xt_register_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
1938 if (ret < 0)
1939 goto err2;
1940 ret = xt_register_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
1941 if (ret < 0)
1942 goto err4;
1943
1944 /* Register setsockopt */
1945 ret = nf_register_sockopt(&ipt_sockopts);
1946 if (ret < 0)
1947 goto err5;
1948
1949 pr_info("(C) 2000-2006 Netfilter Core Team\n");
1950 return 0;
1951
1952 err5:
1953 xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
1954 err4:
1955 xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
1956 err2:
1957 unregister_pernet_subsys(&ip_tables_net_ops);
1958 err1:
1959 return ret;
1960 }
1961
1962 static void __exit ip_tables_fini(void)
1963 {
1964 nf_unregister_sockopt(&ipt_sockopts);
1965
1966 xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
1967 xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
1968 unregister_pernet_subsys(&ip_tables_net_ops);
1969 }
1970
1971 EXPORT_SYMBOL(ipt_register_table);
1972 EXPORT_SYMBOL(ipt_unregister_table);
1973 EXPORT_SYMBOL(ipt_do_table);
1974 module_init(ip_tables_init);
1975 module_exit(ip_tables_fini);
Linux kernel - Deliverables
This page took 0.07254 seconds and 5 git commands to generate.