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Replace <asm/uaccess.h> with <linux/uaccess.h> globally
[linux-2.6/btrfs-unstable.git] / net / ipv4 / netfilter / ip_tables.c
blob91656a1d8fbd5b15b306383fe733751fef10f27c
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
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_DEFAULT_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.state = state;
265
266 IP_NF_ASSERT(table->valid_hooks & (1 << hook));
267 local_bh_disable();
268 addend = xt_write_recseq_begin();
269 private = table->private;
270 cpu = smp_processor_id();
271 /*
272 * Ensure we load private-> members after we've fetched the base
273 * pointer.
274 */
275 smp_read_barrier_depends();
276 table_base = private->entries;
277 jumpstack = (struct ipt_entry **)private->jumpstack[cpu];
278
279 /* Switch to alternate jumpstack if we're being invoked via TEE.
280 * TEE issues XT_CONTINUE verdict on original skb so we must not
281 * clobber the jumpstack.
282 *
283 * For recursion via REJECT or SYNPROXY the stack will be clobbered
284 * but it is no problem since absolute verdict is issued by these.
285 */
286 if (static_key_false(&xt_tee_enabled))
287 jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
288
289 e = get_entry(table_base, private->hook_entry[hook]);
290
291 do {
292 const struct xt_entry_target *t;
293 const struct xt_entry_match *ematch;
294 struct xt_counters *counter;
295
296 IP_NF_ASSERT(e);
297 if (!ip_packet_match(ip, indev, outdev,
298 &e->ip, acpar.fragoff)) {
299 no_match:
300 e = ipt_next_entry(e);
301 continue;
302 }
303
304 xt_ematch_foreach(ematch, e) {
305 acpar.match = ematch->u.kernel.match;
306 acpar.matchinfo = ematch->data;
307 if (!acpar.match->match(skb, &acpar))
308 goto no_match;
309 }
310
311 counter = xt_get_this_cpu_counter(&e->counters);
312 ADD_COUNTER(*counter, skb->len, 1);
313
314 t = ipt_get_target(e);
315 IP_NF_ASSERT(t->u.kernel.target);
316
317 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
318 /* The packet is traced: log it */
319 if (unlikely(skb->nf_trace))
320 trace_packet(state->net, skb, hook, state->in,
321 state->out, table->name, private, e);
322 #endif
323 /* Standard target? */
324 if (!t->u.kernel.target->target) {
325 int v;
326
327 v = ((struct xt_standard_target *)t)->verdict;
328 if (v < 0) {
329 /* Pop from stack? */
330 if (v != XT_RETURN) {
331 verdict = (unsigned int)(-v) - 1;
332 break;
333 }
334 if (stackidx == 0) {
335 e = get_entry(table_base,
336 private->underflow[hook]);
337 } else {
338 e = jumpstack[--stackidx];
339 e = ipt_next_entry(e);
340 }
341 continue;
342 }
343 if (table_base + v != ipt_next_entry(e) &&
344 !(e->ip.flags & IPT_F_GOTO))
345 jumpstack[stackidx++] = e;
346
347 e = get_entry(table_base, v);
348 continue;
349 }
350
351 acpar.target = t->u.kernel.target;
352 acpar.targinfo = t->data;
353
354 verdict = t->u.kernel.target->target(skb, &acpar);
355 /* Target might have changed stuff. */
356 ip = ip_hdr(skb);
357 if (verdict == XT_CONTINUE)
358 e = ipt_next_entry(e);
359 else
360 /* Verdict */
361 break;
362 } while (!acpar.hotdrop);
363
364 xt_write_recseq_end(addend);
365 local_bh_enable();
366
367 if (acpar.hotdrop)
368 return NF_DROP;
369 else return verdict;
370 }
371
372 /* Figures out from what hook each rule can be called: returns 0 if
373 there are loops. Puts hook bitmask in comefrom. */
374 static int
375 mark_source_chains(const struct xt_table_info *newinfo,
376 unsigned int valid_hooks, void *entry0,
377 unsigned int *offsets)
378 {
379 unsigned int hook;
380
381 /* No recursion; use packet counter to save back ptrs (reset
382 to 0 as we leave), and comefrom to save source hook bitmask */
383 for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
384 unsigned int pos = newinfo->hook_entry[hook];
385 struct ipt_entry *e = (struct ipt_entry *)(entry0 + pos);
386
387 if (!(valid_hooks & (1 << hook)))
388 continue;
389
390 /* Set initial back pointer. */
391 e->counters.pcnt = pos;
392
393 for (;;) {
394 const struct xt_standard_target *t
395 = (void *)ipt_get_target_c(e);
396 int visited = e->comefrom & (1 << hook);
397
398 if (e->comefrom & (1 << NF_INET_NUMHOOKS))
399 return 0;
400
401 e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
402
403 /* Unconditional return/END. */
404 if ((unconditional(e) &&
405 (strcmp(t->target.u.user.name,
406 XT_STANDARD_TARGET) == 0) &&
407 t->verdict < 0) || visited) {
408 unsigned int oldpos, size;
409
410 if ((strcmp(t->target.u.user.name,
411 XT_STANDARD_TARGET) == 0) &&
412 t->verdict < -NF_MAX_VERDICT - 1)
413 return 0;
414
415 /* Return: backtrack through the last
416 big jump. */
417 do {
418 e->comefrom ^= (1<<NF_INET_NUMHOOKS);
419 oldpos = pos;
420 pos = e->counters.pcnt;
421 e->counters.pcnt = 0;
422
423 /* We're at the start. */
424 if (pos == oldpos)
425 goto next;
426
427 e = (struct ipt_entry *)
428 (entry0 + pos);
429 } while (oldpos == pos + e->next_offset);
430
431 /* Move along one */
432 size = e->next_offset;
433 e = (struct ipt_entry *)
434 (entry0 + pos + size);
435 if (pos + size >= newinfo->size)
436 return 0;
437 e->counters.pcnt = pos;
438 pos += size;
439 } else {
440 int newpos = t->verdict;
441
442 if (strcmp(t->target.u.user.name,
443 XT_STANDARD_TARGET) == 0 &&
444 newpos >= 0) {
445 /* This a jump; chase it. */
446 if (!xt_find_jump_offset(offsets, newpos,
447 newinfo->number))
448 return 0;
449 e = (struct ipt_entry *)
450 (entry0 + newpos);
451 } else {
452 /* ... this is a fallthru */
453 newpos = pos + e->next_offset;
454 if (newpos >= newinfo->size)
455 return 0;
456 }
457 e = (struct ipt_entry *)
458 (entry0 + newpos);
459 e->counters.pcnt = pos;
460 pos = newpos;
461 }
462 }
463 next: ;
464 }
465 return 1;
466 }
467
468 static void cleanup_match(struct xt_entry_match *m, struct net *net)
469 {
470 struct xt_mtdtor_param par;
471
472 par.net = net;
473 par.match = m->u.kernel.match;
474 par.matchinfo = m->data;
475 par.family = NFPROTO_IPV4;
476 if (par.match->destroy != NULL)
477 par.match->destroy(&par);
478 module_put(par.match->me);
479 }
480
481 static int
482 check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
483 {
484 const struct ipt_ip *ip = par->entryinfo;
485
486 par->match = m->u.kernel.match;
487 par->matchinfo = m->data;
488
489 return xt_check_match(par, m->u.match_size - sizeof(*m),
490 ip->proto, ip->invflags & IPT_INV_PROTO);
491 }
492
493 static int
494 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
495 {
496 struct xt_match *match;
497 int ret;
498
499 match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name,
500 m->u.user.revision);
501 if (IS_ERR(match))
502 return PTR_ERR(match);
503 m->u.kernel.match = match;
504
505 ret = check_match(m, par);
506 if (ret)
507 goto err;
508
509 return 0;
510 err:
511 module_put(m->u.kernel.match->me);
512 return ret;
513 }
514
515 static int check_target(struct ipt_entry *e, struct net *net, const char *name)
516 {
517 struct xt_entry_target *t = ipt_get_target(e);
518 struct xt_tgchk_param par = {
519 .net = net,
520 .table = name,
521 .entryinfo = e,
522 .target = t->u.kernel.target,
523 .targinfo = t->data,
524 .hook_mask = e->comefrom,
525 .family = NFPROTO_IPV4,
526 };
527
528 return xt_check_target(&par, t->u.target_size - sizeof(*t),
529 e->ip.proto, e->ip.invflags & IPT_INV_PROTO);
530 }
531
532 static int
533 find_check_entry(struct ipt_entry *e, struct net *net, const char *name,
534 unsigned int size,
535 struct xt_percpu_counter_alloc_state *alloc_state)
536 {
537 struct xt_entry_target *t;
538 struct xt_target *target;
539 int ret;
540 unsigned int j;
541 struct xt_mtchk_param mtpar;
542 struct xt_entry_match *ematch;
543
544 if (!xt_percpu_counter_alloc(alloc_state, &e->counters))
545 return -ENOMEM;
546
547 j = 0;
548 mtpar.net = net;
549 mtpar.table = name;
550 mtpar.entryinfo = &e->ip;
551 mtpar.hook_mask = e->comefrom;
552 mtpar.family = NFPROTO_IPV4;
553 xt_ematch_foreach(ematch, e) {
554 ret = find_check_match(ematch, &mtpar);
555 if (ret != 0)
556 goto cleanup_matches;
557 ++j;
558 }
559
560 t = ipt_get_target(e);
561 target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name,
562 t->u.user.revision);
563 if (IS_ERR(target)) {
564 ret = PTR_ERR(target);
565 goto cleanup_matches;
566 }
567 t->u.kernel.target = target;
568
569 ret = check_target(e, net, name);
570 if (ret)
571 goto err;
572
573 return 0;
574 err:
575 module_put(t->u.kernel.target->me);
576 cleanup_matches:
577 xt_ematch_foreach(ematch, e) {
578 if (j-- == 0)
579 break;
580 cleanup_match(ematch, net);
581 }
582
583 xt_percpu_counter_free(&e->counters);
584
585 return ret;
586 }
587
588 static bool check_underflow(const struct ipt_entry *e)
589 {
590 const struct xt_entry_target *t;
591 unsigned int verdict;
592
593 if (!unconditional(e))
594 return false;
595 t = ipt_get_target_c(e);
596 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
597 return false;
598 verdict = ((struct xt_standard_target *)t)->verdict;
599 verdict = -verdict - 1;
600 return verdict == NF_DROP || verdict == NF_ACCEPT;
601 }
602
603 static int
604 check_entry_size_and_hooks(struct ipt_entry *e,
605 struct xt_table_info *newinfo,
606 const unsigned char *base,
607 const unsigned char *limit,
608 const unsigned int *hook_entries,
609 const unsigned int *underflows,
610 unsigned int valid_hooks)
611 {
612 unsigned int h;
613 int err;
614
615 if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 ||
616 (unsigned char *)e + sizeof(struct ipt_entry) >= limit ||
617 (unsigned char *)e + e->next_offset > limit)
618 return -EINVAL;
619
620 if (e->next_offset
621 < sizeof(struct ipt_entry) + sizeof(struct xt_entry_target))
622 return -EINVAL;
623
624 if (!ip_checkentry(&e->ip))
625 return -EINVAL;
626
627 err = xt_check_entry_offsets(e, e->elems, e->target_offset,
628 e->next_offset);
629 if (err)
630 return err;
631
632 /* Check hooks & underflows */
633 for (h = 0; h < NF_INET_NUMHOOKS; h++) {
634 if (!(valid_hooks & (1 << h)))
635 continue;
636 if ((unsigned char *)e - base == hook_entries[h])
637 newinfo->hook_entry[h] = hook_entries[h];
638 if ((unsigned char *)e - base == underflows[h]) {
639 if (!check_underflow(e))
640 return -EINVAL;
641
642 newinfo->underflow[h] = underflows[h];
643 }
644 }
645
646 /* Clear counters and comefrom */
647 e->counters = ((struct xt_counters) { 0, 0 });
648 e->comefrom = 0;
649 return 0;
650 }
651
652 static void
653 cleanup_entry(struct ipt_entry *e, struct net *net)
654 {
655 struct xt_tgdtor_param par;
656 struct xt_entry_target *t;
657 struct xt_entry_match *ematch;
658
659 /* Cleanup all matches */
660 xt_ematch_foreach(ematch, e)
661 cleanup_match(ematch, net);
662 t = ipt_get_target(e);
663
664 par.net = net;
665 par.target = t->u.kernel.target;
666 par.targinfo = t->data;
667 par.family = NFPROTO_IPV4;
668 if (par.target->destroy != NULL)
669 par.target->destroy(&par);
670 module_put(par.target->me);
671 xt_percpu_counter_free(&e->counters);
672 }
673
674 /* Checks and translates the user-supplied table segment (held in
675 newinfo) */
676 static int
677 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
678 const struct ipt_replace *repl)
679 {
680 struct xt_percpu_counter_alloc_state alloc_state = { 0 };
681 struct ipt_entry *iter;
682 unsigned int *offsets;
683 unsigned int i;
684 int ret = 0;
685
686 newinfo->size = repl->size;
687 newinfo->number = repl->num_entries;
688
689 /* Init all hooks to impossible value. */
690 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
691 newinfo->hook_entry[i] = 0xFFFFFFFF;
692 newinfo->underflow[i] = 0xFFFFFFFF;
693 }
694
695 offsets = xt_alloc_entry_offsets(newinfo->number);
696 if (!offsets)
697 return -ENOMEM;
698 i = 0;
699 /* Walk through entries, checking offsets. */
700 xt_entry_foreach(iter, entry0, newinfo->size) {
701 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
702 entry0 + repl->size,
703 repl->hook_entry,
704 repl->underflow,
705 repl->valid_hooks);
706 if (ret != 0)
707 goto out_free;
708 if (i < repl->num_entries)
709 offsets[i] = (void *)iter - entry0;
710 ++i;
711 if (strcmp(ipt_get_target(iter)->u.user.name,
712 XT_ERROR_TARGET) == 0)
713 ++newinfo->stacksize;
714 }
715
716 ret = -EINVAL;
717 if (i != repl->num_entries)
718 goto out_free;
719
720 /* Check hooks all assigned */
721 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
722 /* Only hooks which are valid */
723 if (!(repl->valid_hooks & (1 << i)))
724 continue;
725 if (newinfo->hook_entry[i] == 0xFFFFFFFF)
726 goto out_free;
727 if (newinfo->underflow[i] == 0xFFFFFFFF)
728 goto out_free;
729 }
730
731 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) {
732 ret = -ELOOP;
733 goto out_free;
734 }
735 kvfree(offsets);
736
737 /* Finally, each sanity check must pass */
738 i = 0;
739 xt_entry_foreach(iter, entry0, newinfo->size) {
740 ret = find_check_entry(iter, net, repl->name, repl->size,
741 &alloc_state);
742 if (ret != 0)
743 break;
744 ++i;
745 }
746
747 if (ret != 0) {
748 xt_entry_foreach(iter, entry0, newinfo->size) {
749 if (i-- == 0)
750 break;
751 cleanup_entry(iter, net);
752 }
753 return ret;
754 }
755
756 return ret;
757 out_free:
758 kvfree(offsets);
759 return ret;
760 }
761
762 static void
763 get_counters(const struct xt_table_info *t,
764 struct xt_counters counters[])
765 {
766 struct ipt_entry *iter;
767 unsigned int cpu;
768 unsigned int i;
769
770 for_each_possible_cpu(cpu) {
771 seqcount_t *s = &per_cpu(xt_recseq, cpu);
772
773 i = 0;
774 xt_entry_foreach(iter, t->entries, t->size) {
775 struct xt_counters *tmp;
776 u64 bcnt, pcnt;
777 unsigned int start;
778
779 tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
780 do {
781 start = read_seqcount_begin(s);
782 bcnt = tmp->bcnt;
783 pcnt = tmp->pcnt;
784 } while (read_seqcount_retry(s, start));
785
786 ADD_COUNTER(counters[i], bcnt, pcnt);
787 ++i; /* macro does multi eval of i */
788 }
789 }
790 }
791
792 static struct xt_counters *alloc_counters(const struct xt_table *table)
793 {
794 unsigned int countersize;
795 struct xt_counters *counters;
796 const struct xt_table_info *private = table->private;
797
798 /* We need atomic snapshot of counters: rest doesn't change
799 (other than comefrom, which userspace doesn't care
800 about). */
801 countersize = sizeof(struct xt_counters) * private->number;
802 counters = vzalloc(countersize);
803
804 if (counters == NULL)
805 return ERR_PTR(-ENOMEM);
806
807 get_counters(private, counters);
808
809 return counters;
810 }
811
812 static int
813 copy_entries_to_user(unsigned int total_size,
814 const struct xt_table *table,
815 void __user *userptr)
816 {
817 unsigned int off, num;
818 const struct ipt_entry *e;
819 struct xt_counters *counters;
820 const struct xt_table_info *private = table->private;
821 int ret = 0;
822 const void *loc_cpu_entry;
823
824 counters = alloc_counters(table);
825 if (IS_ERR(counters))
826 return PTR_ERR(counters);
827
828 loc_cpu_entry = private->entries;
829 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
830 ret = -EFAULT;
831 goto free_counters;
832 }
833
834 /* FIXME: use iterator macros --RR */
835 /* ... then go back and fix counters and names */
836 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
837 unsigned int i;
838 const struct xt_entry_match *m;
839 const struct xt_entry_target *t;
840
841 e = (struct ipt_entry *)(loc_cpu_entry + off);
842 if (copy_to_user(userptr + off
843 + offsetof(struct ipt_entry, counters),
844 &counters[num],
845 sizeof(counters[num])) != 0) {
846 ret = -EFAULT;
847 goto free_counters;
848 }
849
850 for (i = sizeof(struct ipt_entry);
851 i < e->target_offset;
852 i += m->u.match_size) {
853 m = (void *)e + i;
854
855 if (copy_to_user(userptr + off + i
856 + offsetof(struct xt_entry_match,
857 u.user.name),
858 m->u.kernel.match->name,
859 strlen(m->u.kernel.match->name)+1)
860 != 0) {
861 ret = -EFAULT;
862 goto free_counters;
863 }
864 }
865
866 t = ipt_get_target_c(e);
867 if (copy_to_user(userptr + off + e->target_offset
868 + offsetof(struct xt_entry_target,
869 u.user.name),
870 t->u.kernel.target->name,
871 strlen(t->u.kernel.target->name)+1) != 0) {
872 ret = -EFAULT;
873 goto free_counters;
874 }
875 }
876
877 free_counters:
878 vfree(counters);
879 return ret;
880 }
881
882 #ifdef CONFIG_COMPAT
883 static void compat_standard_from_user(void *dst, const void *src)
884 {
885 int v = *(compat_int_t *)src;
886
887 if (v > 0)
888 v += xt_compat_calc_jump(AF_INET, v);
889 memcpy(dst, &v, sizeof(v));
890 }
891
892 static int compat_standard_to_user(void __user *dst, const void *src)
893 {
894 compat_int_t cv = *(int *)src;
895
896 if (cv > 0)
897 cv -= xt_compat_calc_jump(AF_INET, cv);
898 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
899 }
900
901 static int compat_calc_entry(const struct ipt_entry *e,
902 const struct xt_table_info *info,
903 const void *base, struct xt_table_info *newinfo)
904 {
905 const struct xt_entry_match *ematch;
906 const struct xt_entry_target *t;
907 unsigned int entry_offset;
908 int off, i, ret;
909
910 off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
911 entry_offset = (void *)e - base;
912 xt_ematch_foreach(ematch, e)
913 off += xt_compat_match_offset(ematch->u.kernel.match);
914 t = ipt_get_target_c(e);
915 off += xt_compat_target_offset(t->u.kernel.target);
916 newinfo->size -= off;
917 ret = xt_compat_add_offset(AF_INET, entry_offset, off);
918 if (ret)
919 return ret;
920
921 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
922 if (info->hook_entry[i] &&
923 (e < (struct ipt_entry *)(base + info->hook_entry[i])))
924 newinfo->hook_entry[i] -= off;
925 if (info->underflow[i] &&
926 (e < (struct ipt_entry *)(base + info->underflow[i])))
927 newinfo->underflow[i] -= off;
928 }
929 return 0;
930 }
931
932 static int compat_table_info(const struct xt_table_info *info,
933 struct xt_table_info *newinfo)
934 {
935 struct ipt_entry *iter;
936 const void *loc_cpu_entry;
937 int ret;
938
939 if (!newinfo || !info)
940 return -EINVAL;
941
942 /* we dont care about newinfo->entries */
943 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
944 newinfo->initial_entries = 0;
945 loc_cpu_entry = info->entries;
946 xt_compat_init_offsets(AF_INET, info->number);
947 xt_entry_foreach(iter, loc_cpu_entry, info->size) {
948 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
949 if (ret != 0)
950 return ret;
951 }
952 return 0;
953 }
954 #endif
955
956 static int get_info(struct net *net, void __user *user,
957 const int *len, int compat)
958 {
959 char name[XT_TABLE_MAXNAMELEN];
960 struct xt_table *t;
961 int ret;
962
963 if (*len != sizeof(struct ipt_getinfo))
964 return -EINVAL;
965
966 if (copy_from_user(name, user, sizeof(name)) != 0)
967 return -EFAULT;
968
969 name[XT_TABLE_MAXNAMELEN-1] = '\0';
970 #ifdef CONFIG_COMPAT
971 if (compat)
972 xt_compat_lock(AF_INET);
973 #endif
974 t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
975 "iptable_%s", name);
976 if (t) {
977 struct ipt_getinfo info;
978 const struct xt_table_info *private = t->private;
979 #ifdef CONFIG_COMPAT
980 struct xt_table_info tmp;
981
982 if (compat) {
983 ret = compat_table_info(private, &tmp);
984 xt_compat_flush_offsets(AF_INET);
985 private = &tmp;
986 }
987 #endif
988 memset(&info, 0, sizeof(info));
989 info.valid_hooks = t->valid_hooks;
990 memcpy(info.hook_entry, private->hook_entry,
991 sizeof(info.hook_entry));
992 memcpy(info.underflow, private->underflow,
993 sizeof(info.underflow));
994 info.num_entries = private->number;
995 info.size = private->size;
996 strcpy(info.name, name);
997
998 if (copy_to_user(user, &info, *len) != 0)
999 ret = -EFAULT;
1000 else
1001 ret = 0;
1002
1003 xt_table_unlock(t);
1004 module_put(t->me);
1005 } else
1006 ret = -ENOENT;
1007 #ifdef CONFIG_COMPAT
1008 if (compat)
1009 xt_compat_unlock(AF_INET);
1010 #endif
1011 return ret;
1012 }
1013
1014 static int
1015 get_entries(struct net *net, struct ipt_get_entries __user *uptr,
1016 const int *len)
1017 {
1018 int ret;
1019 struct ipt_get_entries get;
1020 struct xt_table *t;
1021
1022 if (*len < sizeof(get))
1023 return -EINVAL;
1024 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1025 return -EFAULT;
1026 if (*len != sizeof(struct ipt_get_entries) + get.size)
1027 return -EINVAL;
1028 get.name[sizeof(get.name) - 1] = '\0';
1029
1030 t = xt_find_table_lock(net, AF_INET, get.name);
1031 if (t) {
1032 const struct xt_table_info *private = t->private;
1033 if (get.size == private->size)
1034 ret = copy_entries_to_user(private->size,
1035 t, uptr->entrytable);
1036 else
1037 ret = -EAGAIN;
1038
1039 module_put(t->me);
1040 xt_table_unlock(t);
1041 } else
1042 ret = -ENOENT;
1043
1044 return ret;
1045 }
1046
1047 static int
1048 __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
1049 struct xt_table_info *newinfo, unsigned int num_counters,
1050 void __user *counters_ptr)
1051 {
1052 int ret;
1053 struct xt_table *t;
1054 struct xt_table_info *oldinfo;
1055 struct xt_counters *counters;
1056 struct ipt_entry *iter;
1057
1058 ret = 0;
1059 counters = vzalloc(num_counters * sizeof(struct xt_counters));
1060 if (!counters) {
1061 ret = -ENOMEM;
1062 goto out;
1063 }
1064
1065 t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
1066 "iptable_%s", name);
1067 if (!t) {
1068 ret = -ENOENT;
1069 goto free_newinfo_counters_untrans;
1070 }
1071
1072 /* You lied! */
1073 if (valid_hooks != t->valid_hooks) {
1074 ret = -EINVAL;
1075 goto put_module;
1076 }
1077
1078 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1079 if (!oldinfo)
1080 goto put_module;
1081
1082 /* Update module usage count based on number of rules */
1083 if ((oldinfo->number > oldinfo->initial_entries) ||
1084 (newinfo->number <= oldinfo->initial_entries))
1085 module_put(t->me);
1086 if ((oldinfo->number > oldinfo->initial_entries) &&
1087 (newinfo->number <= oldinfo->initial_entries))
1088 module_put(t->me);
1089
1090 /* Get the old counters, and synchronize with replace */
1091 get_counters(oldinfo, counters);
1092
1093 /* Decrease module usage counts and free resource */
1094 xt_entry_foreach(iter, oldinfo->entries, oldinfo->size)
1095 cleanup_entry(iter, net);
1096
1097 xt_free_table_info(oldinfo);
1098 if (copy_to_user(counters_ptr, counters,
1099 sizeof(struct xt_counters) * num_counters) != 0) {
1100 /* Silent error, can't fail, new table is already in place */
1101 net_warn_ratelimited("iptables: counters copy to user failed while replacing table\n");
1102 }
1103 vfree(counters);
1104 xt_table_unlock(t);
1105 return ret;
1106
1107 put_module:
1108 module_put(t->me);
1109 xt_table_unlock(t);
1110 free_newinfo_counters_untrans:
1111 vfree(counters);
1112 out:
1113 return ret;
1114 }
1115
1116 static int
1117 do_replace(struct net *net, const void __user *user, unsigned int len)
1118 {
1119 int ret;
1120 struct ipt_replace tmp;
1121 struct xt_table_info *newinfo;
1122 void *loc_cpu_entry;
1123 struct ipt_entry *iter;
1124
1125 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1126 return -EFAULT;
1127
1128 /* overflow check */
1129 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1130 return -ENOMEM;
1131 if (tmp.num_counters == 0)
1132 return -EINVAL;
1133
1134 tmp.name[sizeof(tmp.name)-1] = 0;
1135
1136 newinfo = xt_alloc_table_info(tmp.size);
1137 if (!newinfo)
1138 return -ENOMEM;
1139
1140 loc_cpu_entry = newinfo->entries;
1141 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1142 tmp.size) != 0) {
1143 ret = -EFAULT;
1144 goto free_newinfo;
1145 }
1146
1147 ret = translate_table(net, newinfo, loc_cpu_entry, &tmp);
1148 if (ret != 0)
1149 goto free_newinfo;
1150
1151 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1152 tmp.num_counters, tmp.counters);
1153 if (ret)
1154 goto free_newinfo_untrans;
1155 return 0;
1156
1157 free_newinfo_untrans:
1158 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1159 cleanup_entry(iter, net);
1160 free_newinfo:
1161 xt_free_table_info(newinfo);
1162 return ret;
1163 }
1164
1165 static int
1166 do_add_counters(struct net *net, const void __user *user,
1167 unsigned int len, int compat)
1168 {
1169 unsigned int i;
1170 struct xt_counters_info tmp;
1171 struct xt_counters *paddc;
1172 struct xt_table *t;
1173 const struct xt_table_info *private;
1174 int ret = 0;
1175 struct ipt_entry *iter;
1176 unsigned int addend;
1177
1178 paddc = xt_copy_counters_from_user(user, len, &tmp, compat);
1179 if (IS_ERR(paddc))
1180 return PTR_ERR(paddc);
1181
1182 t = xt_find_table_lock(net, AF_INET, tmp.name);
1183 if (!t) {
1184 ret = -ENOENT;
1185 goto free;
1186 }
1187
1188 local_bh_disable();
1189 private = t->private;
1190 if (private->number != tmp.num_counters) {
1191 ret = -EINVAL;
1192 goto unlock_up_free;
1193 }
1194
1195 i = 0;
1196 addend = xt_write_recseq_begin();
1197 xt_entry_foreach(iter, private->entries, private->size) {
1198 struct xt_counters *tmp;
1199
1200 tmp = xt_get_this_cpu_counter(&iter->counters);
1201 ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt);
1202 ++i;
1203 }
1204 xt_write_recseq_end(addend);
1205 unlock_up_free:
1206 local_bh_enable();
1207 xt_table_unlock(t);
1208 module_put(t->me);
1209 free:
1210 vfree(paddc);
1211
1212 return ret;
1213 }
1214
1215 #ifdef CONFIG_COMPAT
1216 struct compat_ipt_replace {
1217 char name[XT_TABLE_MAXNAMELEN];
1218 u32 valid_hooks;
1219 u32 num_entries;
1220 u32 size;
1221 u32 hook_entry[NF_INET_NUMHOOKS];
1222 u32 underflow[NF_INET_NUMHOOKS];
1223 u32 num_counters;
1224 compat_uptr_t counters; /* struct xt_counters * */
1225 struct compat_ipt_entry entries[0];
1226 };
1227
1228 static int
1229 compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr,
1230 unsigned int *size, struct xt_counters *counters,
1231 unsigned int i)
1232 {
1233 struct xt_entry_target *t;
1234 struct compat_ipt_entry __user *ce;
1235 u_int16_t target_offset, next_offset;
1236 compat_uint_t origsize;
1237 const struct xt_entry_match *ematch;
1238 int ret = 0;
1239
1240 origsize = *size;
1241 ce = (struct compat_ipt_entry __user *)*dstptr;
1242 if (copy_to_user(ce, e, sizeof(struct ipt_entry)) != 0 ||
1243 copy_to_user(&ce->counters, &counters[i],
1244 sizeof(counters[i])) != 0)
1245 return -EFAULT;
1246
1247 *dstptr += sizeof(struct compat_ipt_entry);
1248 *size -= sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1249
1250 xt_ematch_foreach(ematch, e) {
1251 ret = xt_compat_match_to_user(ematch, dstptr, size);
1252 if (ret != 0)
1253 return ret;
1254 }
1255 target_offset = e->target_offset - (origsize - *size);
1256 t = ipt_get_target(e);
1257 ret = xt_compat_target_to_user(t, dstptr, size);
1258 if (ret)
1259 return ret;
1260 next_offset = e->next_offset - (origsize - *size);
1261 if (put_user(target_offset, &ce->target_offset) != 0 ||
1262 put_user(next_offset, &ce->next_offset) != 0)
1263 return -EFAULT;
1264 return 0;
1265 }
1266
1267 static int
1268 compat_find_calc_match(struct xt_entry_match *m,
1269 const struct ipt_ip *ip,
1270 int *size)
1271 {
1272 struct xt_match *match;
1273
1274 match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name,
1275 m->u.user.revision);
1276 if (IS_ERR(match))
1277 return PTR_ERR(match);
1278
1279 m->u.kernel.match = match;
1280 *size += xt_compat_match_offset(match);
1281 return 0;
1282 }
1283
1284 static void compat_release_entry(struct compat_ipt_entry *e)
1285 {
1286 struct xt_entry_target *t;
1287 struct xt_entry_match *ematch;
1288
1289 /* Cleanup all matches */
1290 xt_ematch_foreach(ematch, e)
1291 module_put(ematch->u.kernel.match->me);
1292 t = compat_ipt_get_target(e);
1293 module_put(t->u.kernel.target->me);
1294 }
1295
1296 static int
1297 check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
1298 struct xt_table_info *newinfo,
1299 unsigned int *size,
1300 const unsigned char *base,
1301 const unsigned char *limit)
1302 {
1303 struct xt_entry_match *ematch;
1304 struct xt_entry_target *t;
1305 struct xt_target *target;
1306 unsigned int entry_offset;
1307 unsigned int j;
1308 int ret, off;
1309
1310 if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0 ||
1311 (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit ||
1312 (unsigned char *)e + e->next_offset > limit)
1313 return -EINVAL;
1314
1315 if (e->next_offset < sizeof(struct compat_ipt_entry) +
1316 sizeof(struct compat_xt_entry_target))
1317 return -EINVAL;
1318
1319 if (!ip_checkentry(&e->ip))
1320 return -EINVAL;
1321
1322 ret = xt_compat_check_entry_offsets(e, e->elems,
1323 e->target_offset, e->next_offset);
1324 if (ret)
1325 return ret;
1326
1327 off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1328 entry_offset = (void *)e - (void *)base;
1329 j = 0;
1330 xt_ematch_foreach(ematch, e) {
1331 ret = compat_find_calc_match(ematch, &e->ip, &off);
1332 if (ret != 0)
1333 goto release_matches;
1334 ++j;
1335 }
1336
1337 t = compat_ipt_get_target(e);
1338 target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name,
1339 t->u.user.revision);
1340 if (IS_ERR(target)) {
1341 ret = PTR_ERR(target);
1342 goto release_matches;
1343 }
1344 t->u.kernel.target = target;
1345
1346 off += xt_compat_target_offset(target);
1347 *size += off;
1348 ret = xt_compat_add_offset(AF_INET, entry_offset, off);
1349 if (ret)
1350 goto out;
1351
1352 return 0;
1353
1354 out:
1355 module_put(t->u.kernel.target->me);
1356 release_matches:
1357 xt_ematch_foreach(ematch, e) {
1358 if (j-- == 0)
1359 break;
1360 module_put(ematch->u.kernel.match->me);
1361 }
1362 return ret;
1363 }
1364
1365 static void
1366 compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
1367 unsigned int *size,
1368 struct xt_table_info *newinfo, unsigned char *base)
1369 {
1370 struct xt_entry_target *t;
1371 struct xt_target *target;
1372 struct ipt_entry *de;
1373 unsigned int origsize;
1374 int h;
1375 struct xt_entry_match *ematch;
1376
1377 origsize = *size;
1378 de = (struct ipt_entry *)*dstptr;
1379 memcpy(de, e, sizeof(struct ipt_entry));
1380 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1381
1382 *dstptr += sizeof(struct ipt_entry);
1383 *size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1384
1385 xt_ematch_foreach(ematch, e)
1386 xt_compat_match_from_user(ematch, dstptr, size);
1387
1388 de->target_offset = e->target_offset - (origsize - *size);
1389 t = compat_ipt_get_target(e);
1390 target = t->u.kernel.target;
1391 xt_compat_target_from_user(t, dstptr, size);
1392
1393 de->next_offset = e->next_offset - (origsize - *size);
1394
1395 for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1396 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1397 newinfo->hook_entry[h] -= origsize - *size;
1398 if ((unsigned char *)de - base < newinfo->underflow[h])
1399 newinfo->underflow[h] -= origsize - *size;
1400 }
1401 }
1402
1403 static int
1404 translate_compat_table(struct net *net,
1405 struct xt_table_info **pinfo,
1406 void **pentry0,
1407 const struct compat_ipt_replace *compatr)
1408 {
1409 unsigned int i, j;
1410 struct xt_table_info *newinfo, *info;
1411 void *pos, *entry0, *entry1;
1412 struct compat_ipt_entry *iter0;
1413 struct ipt_replace repl;
1414 unsigned int size;
1415 int ret;
1416
1417 info = *pinfo;
1418 entry0 = *pentry0;
1419 size = compatr->size;
1420 info->number = compatr->num_entries;
1421
1422 j = 0;
1423 xt_compat_lock(AF_INET);
1424 xt_compat_init_offsets(AF_INET, compatr->num_entries);
1425 /* Walk through entries, checking offsets. */
1426 xt_entry_foreach(iter0, entry0, compatr->size) {
1427 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1428 entry0,
1429 entry0 + compatr->size);
1430 if (ret != 0)
1431 goto out_unlock;
1432 ++j;
1433 }
1434
1435 ret = -EINVAL;
1436 if (j != compatr->num_entries)
1437 goto out_unlock;
1438
1439 ret = -ENOMEM;
1440 newinfo = xt_alloc_table_info(size);
1441 if (!newinfo)
1442 goto out_unlock;
1443
1444 newinfo->number = compatr->num_entries;
1445 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1446 newinfo->hook_entry[i] = compatr->hook_entry[i];
1447 newinfo->underflow[i] = compatr->underflow[i];
1448 }
1449 entry1 = newinfo->entries;
1450 pos = entry1;
1451 size = compatr->size;
1452 xt_entry_foreach(iter0, entry0, compatr->size)
1453 compat_copy_entry_from_user(iter0, &pos, &size,
1454 newinfo, entry1);
1455
1456 /* all module references in entry0 are now gone.
1457 * entry1/newinfo contains a 64bit ruleset that looks exactly as
1458 * generated by 64bit userspace.
1459 *
1460 * Call standard translate_table() to validate all hook_entrys,
1461 * underflows, check for loops, etc.
1462 */
1463 xt_compat_flush_offsets(AF_INET);
1464 xt_compat_unlock(AF_INET);
1465
1466 memcpy(&repl, compatr, sizeof(*compatr));
1467
1468 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1469 repl.hook_entry[i] = newinfo->hook_entry[i];
1470 repl.underflow[i] = newinfo->underflow[i];
1471 }
1472
1473 repl.num_counters = 0;
1474 repl.counters = NULL;
1475 repl.size = newinfo->size;
1476 ret = translate_table(net, newinfo, entry1, &repl);
1477 if (ret)
1478 goto free_newinfo;
1479
1480 *pinfo = newinfo;
1481 *pentry0 = entry1;
1482 xt_free_table_info(info);
1483 return 0;
1484
1485 free_newinfo:
1486 xt_free_table_info(newinfo);
1487 return ret;
1488 out_unlock:
1489 xt_compat_flush_offsets(AF_INET);
1490 xt_compat_unlock(AF_INET);
1491 xt_entry_foreach(iter0, entry0, compatr->size) {
1492 if (j-- == 0)
1493 break;
1494 compat_release_entry(iter0);
1495 }
1496 return ret;
1497 }
1498
1499 static int
1500 compat_do_replace(struct net *net, void __user *user, unsigned int len)
1501 {
1502 int ret;
1503 struct compat_ipt_replace tmp;
1504 struct xt_table_info *newinfo;
1505 void *loc_cpu_entry;
1506 struct ipt_entry *iter;
1507
1508 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1509 return -EFAULT;
1510
1511 /* overflow check */
1512 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1513 return -ENOMEM;
1514 if (tmp.num_counters == 0)
1515 return -EINVAL;
1516
1517 tmp.name[sizeof(tmp.name)-1] = 0;
1518
1519 newinfo = xt_alloc_table_info(tmp.size);
1520 if (!newinfo)
1521 return -ENOMEM;
1522
1523 loc_cpu_entry = newinfo->entries;
1524 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1525 tmp.size) != 0) {
1526 ret = -EFAULT;
1527 goto free_newinfo;
1528 }
1529
1530 ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp);
1531 if (ret != 0)
1532 goto free_newinfo;
1533
1534 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1535 tmp.num_counters, compat_ptr(tmp.counters));
1536 if (ret)
1537 goto free_newinfo_untrans;
1538 return 0;
1539
1540 free_newinfo_untrans:
1541 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1542 cleanup_entry(iter, net);
1543 free_newinfo:
1544 xt_free_table_info(newinfo);
1545 return ret;
1546 }
1547
1548 static int
1549 compat_do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user,
1550 unsigned int len)
1551 {
1552 int ret;
1553
1554 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1555 return -EPERM;
1556
1557 switch (cmd) {
1558 case IPT_SO_SET_REPLACE:
1559 ret = compat_do_replace(sock_net(sk), user, len);
1560 break;
1561
1562 case IPT_SO_SET_ADD_COUNTERS:
1563 ret = do_add_counters(sock_net(sk), user, len, 1);
1564 break;
1565
1566 default:
1567 ret = -EINVAL;
1568 }
1569
1570 return ret;
1571 }
1572
1573 struct compat_ipt_get_entries {
1574 char name[XT_TABLE_MAXNAMELEN];
1575 compat_uint_t size;
1576 struct compat_ipt_entry entrytable[0];
1577 };
1578
1579 static int
1580 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
1581 void __user *userptr)
1582 {
1583 struct xt_counters *counters;
1584 const struct xt_table_info *private = table->private;
1585 void __user *pos;
1586 unsigned int size;
1587 int ret = 0;
1588 unsigned int i = 0;
1589 struct ipt_entry *iter;
1590
1591 counters = alloc_counters(table);
1592 if (IS_ERR(counters))
1593 return PTR_ERR(counters);
1594
1595 pos = userptr;
1596 size = total_size;
1597 xt_entry_foreach(iter, private->entries, total_size) {
1598 ret = compat_copy_entry_to_user(iter, &pos,
1599 &size, counters, i++);
1600 if (ret != 0)
1601 break;
1602 }
1603
1604 vfree(counters);
1605 return ret;
1606 }
1607
1608 static int
1609 compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr,
1610 int *len)
1611 {
1612 int ret;
1613 struct compat_ipt_get_entries get;
1614 struct xt_table *t;
1615
1616 if (*len < sizeof(get))
1617 return -EINVAL;
1618
1619 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1620 return -EFAULT;
1621
1622 if (*len != sizeof(struct compat_ipt_get_entries) + get.size)
1623 return -EINVAL;
1624
1625 get.name[sizeof(get.name) - 1] = '\0';
1626
1627 xt_compat_lock(AF_INET);
1628 t = xt_find_table_lock(net, AF_INET, get.name);
1629 if (t) {
1630 const struct xt_table_info *private = t->private;
1631 struct xt_table_info info;
1632 ret = compat_table_info(private, &info);
1633 if (!ret && get.size == info.size)
1634 ret = compat_copy_entries_to_user(private->size,
1635 t, uptr->entrytable);
1636 else if (!ret)
1637 ret = -EAGAIN;
1638
1639 xt_compat_flush_offsets(AF_INET);
1640 module_put(t->me);
1641 xt_table_unlock(t);
1642 } else
1643 ret = -ENOENT;
1644
1645 xt_compat_unlock(AF_INET);
1646 return ret;
1647 }
1648
1649 static int do_ipt_get_ctl(struct sock *, int, void __user *, int *);
1650
1651 static int
1652 compat_do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1653 {
1654 int ret;
1655
1656 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1657 return -EPERM;
1658
1659 switch (cmd) {
1660 case IPT_SO_GET_INFO:
1661 ret = get_info(sock_net(sk), user, len, 1);
1662 break;
1663 case IPT_SO_GET_ENTRIES:
1664 ret = compat_get_entries(sock_net(sk), user, len);
1665 break;
1666 default:
1667 ret = do_ipt_get_ctl(sk, cmd, user, len);
1668 }
1669 return ret;
1670 }
1671 #endif
1672
1673 static int
1674 do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1675 {
1676 int ret;
1677
1678 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1679 return -EPERM;
1680
1681 switch (cmd) {
1682 case IPT_SO_SET_REPLACE:
1683 ret = do_replace(sock_net(sk), user, len);
1684 break;
1685
1686 case IPT_SO_SET_ADD_COUNTERS:
1687 ret = do_add_counters(sock_net(sk), user, len, 0);
1688 break;
1689
1690 default:
1691 ret = -EINVAL;
1692 }
1693
1694 return ret;
1695 }
1696
1697 static int
1698 do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1699 {
1700 int ret;
1701
1702 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1703 return -EPERM;
1704
1705 switch (cmd) {
1706 case IPT_SO_GET_INFO:
1707 ret = get_info(sock_net(sk), user, len, 0);
1708 break;
1709
1710 case IPT_SO_GET_ENTRIES:
1711 ret = get_entries(sock_net(sk), user, len);
1712 break;
1713
1714 case IPT_SO_GET_REVISION_MATCH:
1715 case IPT_SO_GET_REVISION_TARGET: {
1716 struct xt_get_revision rev;
1717 int target;
1718
1719 if (*len != sizeof(rev)) {
1720 ret = -EINVAL;
1721 break;
1722 }
1723 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1724 ret = -EFAULT;
1725 break;
1726 }
1727 rev.name[sizeof(rev.name)-1] = 0;
1728
1729 if (cmd == IPT_SO_GET_REVISION_TARGET)
1730 target = 1;
1731 else
1732 target = 0;
1733
1734 try_then_request_module(xt_find_revision(AF_INET, rev.name,
1735 rev.revision,
1736 target, &ret),
1737 "ipt_%s", rev.name);
1738 break;
1739 }
1740
1741 default:
1742 ret = -EINVAL;
1743 }
1744
1745 return ret;
1746 }
1747
1748 static void __ipt_unregister_table(struct net *net, struct xt_table *table)
1749 {
1750 struct xt_table_info *private;
1751 void *loc_cpu_entry;
1752 struct module *table_owner = table->me;
1753 struct ipt_entry *iter;
1754
1755 private = xt_unregister_table(table);
1756
1757 /* Decrease module usage counts and free resources */
1758 loc_cpu_entry = private->entries;
1759 xt_entry_foreach(iter, loc_cpu_entry, private->size)
1760 cleanup_entry(iter, net);
1761 if (private->number > private->initial_entries)
1762 module_put(table_owner);
1763 xt_free_table_info(private);
1764 }
1765
1766 int ipt_register_table(struct net *net, const struct xt_table *table,
1767 const struct ipt_replace *repl,
1768 const struct nf_hook_ops *ops, struct xt_table **res)
1769 {
1770 int ret;
1771 struct xt_table_info *newinfo;
1772 struct xt_table_info bootstrap = {0};
1773 void *loc_cpu_entry;
1774 struct xt_table *new_table;
1775
1776 newinfo = xt_alloc_table_info(repl->size);
1777 if (!newinfo)
1778 return -ENOMEM;
1779
1780 loc_cpu_entry = newinfo->entries;
1781 memcpy(loc_cpu_entry, repl->entries, repl->size);
1782
1783 ret = translate_table(net, newinfo, loc_cpu_entry, repl);
1784 if (ret != 0)
1785 goto out_free;
1786
1787 new_table = xt_register_table(net, table, &bootstrap, newinfo);
1788 if (IS_ERR(new_table)) {
1789 ret = PTR_ERR(new_table);
1790 goto out_free;
1791 }
1792
1793 /* set res now, will see skbs right after nf_register_net_hooks */
1794 WRITE_ONCE(*res, new_table);
1795
1796 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
1797 if (ret != 0) {
1798 __ipt_unregister_table(net, new_table);
1799 *res = NULL;
1800 }
1801
1802 return ret;
1803
1804 out_free:
1805 xt_free_table_info(newinfo);
1806 return ret;
1807 }
1808
1809 void ipt_unregister_table(struct net *net, struct xt_table *table,
1810 const struct nf_hook_ops *ops)
1811 {
1812 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
1813 __ipt_unregister_table(net, table);
1814 }
1815
1816 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
1817 static inline bool
1818 icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
1819 u_int8_t type, u_int8_t code,
1820 bool invert)
1821 {
1822 return ((test_type == 0xFF) ||
1823 (type == test_type && code >= min_code && code <= max_code))
1824 ^ invert;
1825 }
1826
1827 static bool
1828 icmp_match(const struct sk_buff *skb, struct xt_action_param *par)
1829 {
1830 const struct icmphdr *ic;
1831 struct icmphdr _icmph;
1832 const struct ipt_icmp *icmpinfo = par->matchinfo;
1833
1834 /* Must not be a fragment. */
1835 if (par->fragoff != 0)
1836 return false;
1837
1838 ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph);
1839 if (ic == NULL) {
1840 /* We've been asked to examine this packet, and we
1841 * can't. Hence, no choice but to drop.
1842 */
1843 par->hotdrop = true;
1844 return false;
1845 }
1846
1847 return icmp_type_code_match(icmpinfo->type,
1848 icmpinfo->code[0],
1849 icmpinfo->code[1],
1850 ic->type, ic->code,
1851 !!(icmpinfo->invflags&IPT_ICMP_INV));
1852 }
1853
1854 static int icmp_checkentry(const struct xt_mtchk_param *par)
1855 {
1856 const struct ipt_icmp *icmpinfo = par->matchinfo;
1857
1858 /* Must specify no unknown invflags */
1859 return (icmpinfo->invflags & ~IPT_ICMP_INV) ? -EINVAL : 0;
1860 }
1861
1862 static struct xt_target ipt_builtin_tg[] __read_mostly = {
1863 {
1864 .name = XT_STANDARD_TARGET,
1865 .targetsize = sizeof(int),
1866 .family = NFPROTO_IPV4,
1867 #ifdef CONFIG_COMPAT
1868 .compatsize = sizeof(compat_int_t),
1869 .compat_from_user = compat_standard_from_user,
1870 .compat_to_user = compat_standard_to_user,
1871 #endif
1872 },
1873 {
1874 .name = XT_ERROR_TARGET,
1875 .target = ipt_error,
1876 .targetsize = XT_FUNCTION_MAXNAMELEN,
1877 .family = NFPROTO_IPV4,
1878 },
1879 };
1880
1881 static struct nf_sockopt_ops ipt_sockopts = {
1882 .pf = PF_INET,
1883 .set_optmin = IPT_BASE_CTL,
1884 .set_optmax = IPT_SO_SET_MAX+1,
1885 .set = do_ipt_set_ctl,
1886 #ifdef CONFIG_COMPAT
1887 .compat_set = compat_do_ipt_set_ctl,
1888 #endif
1889 .get_optmin = IPT_BASE_CTL,
1890 .get_optmax = IPT_SO_GET_MAX+1,
1891 .get = do_ipt_get_ctl,
1892 #ifdef CONFIG_COMPAT
1893 .compat_get = compat_do_ipt_get_ctl,
1894 #endif
1895 .owner = THIS_MODULE,
1896 };
1897
1898 static struct xt_match ipt_builtin_mt[] __read_mostly = {
1899 {
1900 .name = "icmp",
1901 .match = icmp_match,
1902 .matchsize = sizeof(struct ipt_icmp),
1903 .checkentry = icmp_checkentry,
1904 .proto = IPPROTO_ICMP,
1905 .family = NFPROTO_IPV4,
1906 },
1907 };
1908
1909 static int __net_init ip_tables_net_init(struct net *net)
1910 {
1911 return xt_proto_init(net, NFPROTO_IPV4);
1912 }
1913
1914 static void __net_exit ip_tables_net_exit(struct net *net)
1915 {
1916 xt_proto_fini(net, NFPROTO_IPV4);
1917 }
1918
1919 static struct pernet_operations ip_tables_net_ops = {
1920 .init = ip_tables_net_init,
1921 .exit = ip_tables_net_exit,
1922 };
1923
1924 static int __init ip_tables_init(void)
1925 {
1926 int ret;
1927
1928 ret = register_pernet_subsys(&ip_tables_net_ops);
1929 if (ret < 0)
1930 goto err1;
1931
1932 /* No one else will be downing sem now, so we won't sleep */
1933 ret = xt_register_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
1934 if (ret < 0)
1935 goto err2;
1936 ret = xt_register_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
1937 if (ret < 0)
1938 goto err4;
1939
1940 /* Register setsockopt */
1941 ret = nf_register_sockopt(&ipt_sockopts);
1942 if (ret < 0)
1943 goto err5;
1944
1945 pr_info("(C) 2000-2006 Netfilter Core Team\n");
1946 return 0;
1947
1948 err5:
1949 xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
1950 err4:
1951 xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
1952 err2:
1953 unregister_pernet_subsys(&ip_tables_net_ops);
1954 err1:
1955 return ret;
1956 }
1957
1958 static void __exit ip_tables_fini(void)
1959 {
1960 nf_unregister_sockopt(&ipt_sockopts);
1961
1962 xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
1963 xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
1964 unregister_pernet_subsys(&ip_tables_net_ops);
1965 }
1966
1967 EXPORT_SYMBOL(ipt_register_table);
1968 EXPORT_SYMBOL(ipt_unregister_table);
1969 EXPORT_SYMBOL(ipt_do_table);
1970 module_init(ip_tables_init);
1971 module_exit(ip_tables_fini);
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