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Committer: Michael Beasley <mike@snafu.setup>
[mikesnafu-overlay.git] / net / ipv4 / netfilter / ip_tables.c
blob600737f122d2eee84f269f3abffe2b02880d454b
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 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11 #include <linux/cache.h>
12 #include <linux/capability.h>
13 #include <linux/skbuff.h>
14 #include <linux/kmod.h>
15 #include <linux/vmalloc.h>
16 #include <linux/netdevice.h>
17 #include <linux/module.h>
18 #include <linux/icmp.h>
19 #include <net/ip.h>
20 #include <net/compat.h>
21 #include <asm/uaccess.h>
22 #include <linux/mutex.h>
23 #include <linux/proc_fs.h>
24 #include <linux/err.h>
25 #include <linux/cpumask.h>
26
27 #include <linux/netfilter/x_tables.h>
28 #include <linux/netfilter_ipv4/ip_tables.h>
29 #include <net/netfilter/nf_log.h>
30
31 MODULE_LICENSE("GPL");
32 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
33 MODULE_DESCRIPTION("IPv4 packet filter");
34
35 /*#define DEBUG_IP_FIREWALL*/
36 /*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */
37 /*#define DEBUG_IP_FIREWALL_USER*/
38
39 #ifdef DEBUG_IP_FIREWALL
40 #define dprintf(format, args...) printk(format , ## args)
41 #else
42 #define dprintf(format, args...)
43 #endif
44
45 #ifdef DEBUG_IP_FIREWALL_USER
46 #define duprintf(format, args...) printk(format , ## args)
47 #else
48 #define duprintf(format, args...)
49 #endif
50
51 #ifdef CONFIG_NETFILTER_DEBUG
52 #define IP_NF_ASSERT(x) \
53 do { \
54 if (!(x)) \
55 printk("IP_NF_ASSERT: %s:%s:%u\n", \
56 __FUNCTION__, __FILE__, __LINE__); \
57 } while(0)
58 #else
59 #define IP_NF_ASSERT(x)
60 #endif
61
62 #if 0
63 /* All the better to debug you with... */
64 #define static
65 #define inline
66 #endif
67
68 /*
69 We keep a set of rules for each CPU, so we can avoid write-locking
70 them in the softirq when updating the counters and therefore
71 only need to read-lock in the softirq; doing a write_lock_bh() in user
72 context stops packets coming through and allows user context to read
73 the counters or update the rules.
74
75 Hence the start of any table is given by get_table() below. */
76
77 /* Returns whether matches rule or not. */
78 /* Performance critical - called for every packet */
79 static inline bool
80 ip_packet_match(const struct iphdr *ip,
81 const char *indev,
82 const char *outdev,
83 const struct ipt_ip *ipinfo,
84 int isfrag)
85 {
86 size_t i;
87 unsigned long ret;
88
89 #define FWINV(bool, invflg) ((bool) ^ !!(ipinfo->invflags & (invflg)))
90
91 if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
92 IPT_INV_SRCIP)
93 || FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
94 IPT_INV_DSTIP)) {
95 dprintf("Source or dest mismatch.\n");
96
97 dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
98 NIPQUAD(ip->saddr),
99 NIPQUAD(ipinfo->smsk.s_addr),
100 NIPQUAD(ipinfo->src.s_addr),
101 ipinfo->invflags & IPT_INV_SRCIP ? " (INV)" : "");
102 dprintf("DST: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
103 NIPQUAD(ip->daddr),
104 NIPQUAD(ipinfo->dmsk.s_addr),
105 NIPQUAD(ipinfo->dst.s_addr),
106 ipinfo->invflags & IPT_INV_DSTIP ? " (INV)" : "");
107 return false;
108 }
109
110 /* Look for ifname matches; this should unroll nicely. */
111 for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
112 ret |= (((const unsigned long *)indev)[i]
113 ^ ((const unsigned long *)ipinfo->iniface)[i])
114 & ((const unsigned long *)ipinfo->iniface_mask)[i];
115 }
116
117 if (FWINV(ret != 0, IPT_INV_VIA_IN)) {
118 dprintf("VIA in mismatch (%s vs %s).%s\n",
119 indev, ipinfo->iniface,
120 ipinfo->invflags&IPT_INV_VIA_IN ?" (INV)":"");
121 return false;
122 }
123
124 for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
125 ret |= (((const unsigned long *)outdev)[i]
126 ^ ((const unsigned long *)ipinfo->outiface)[i])
127 & ((const unsigned long *)ipinfo->outiface_mask)[i];
128 }
129
130 if (FWINV(ret != 0, IPT_INV_VIA_OUT)) {
131 dprintf("VIA out mismatch (%s vs %s).%s\n",
132 outdev, ipinfo->outiface,
133 ipinfo->invflags&IPT_INV_VIA_OUT ?" (INV)":"");
134 return false;
135 }
136
137 /* Check specific protocol */
138 if (ipinfo->proto
139 && FWINV(ip->protocol != ipinfo->proto, IPT_INV_PROTO)) {
140 dprintf("Packet protocol %hi does not match %hi.%s\n",
141 ip->protocol, ipinfo->proto,
142 ipinfo->invflags&IPT_INV_PROTO ? " (INV)":"");
143 return false;
144 }
145
146 /* If we have a fragment rule but the packet is not a fragment
147 * then we return zero */
148 if (FWINV((ipinfo->flags&IPT_F_FRAG) && !isfrag, IPT_INV_FRAG)) {
149 dprintf("Fragment rule but not fragment.%s\n",
150 ipinfo->invflags & IPT_INV_FRAG ? " (INV)" : "");
151 return false;
152 }
153
154 return true;
155 }
156
157 static bool
158 ip_checkentry(const struct ipt_ip *ip)
159 {
160 if (ip->flags & ~IPT_F_MASK) {
161 duprintf("Unknown flag bits set: %08X\n",
162 ip->flags & ~IPT_F_MASK);
163 return false;
164 }
165 if (ip->invflags & ~IPT_INV_MASK) {
166 duprintf("Unknown invflag bits set: %08X\n",
167 ip->invflags & ~IPT_INV_MASK);
168 return false;
169 }
170 return true;
171 }
172
173 static unsigned int
174 ipt_error(struct sk_buff *skb,
175 const struct net_device *in,
176 const struct net_device *out,
177 unsigned int hooknum,
178 const struct xt_target *target,
179 const void *targinfo)
180 {
181 if (net_ratelimit())
182 printk("ip_tables: error: `%s'\n", (char *)targinfo);
183
184 return NF_DROP;
185 }
186
187 /* Performance critical - called for every packet */
188 static inline bool
189 do_match(struct ipt_entry_match *m,
190 const struct sk_buff *skb,
191 const struct net_device *in,
192 const struct net_device *out,
193 int offset,
194 bool *hotdrop)
195 {
196 /* Stop iteration if it doesn't match */
197 if (!m->u.kernel.match->match(skb, in, out, m->u.kernel.match, m->data,
198 offset, ip_hdrlen(skb), hotdrop))
199 return true;
200 else
201 return false;
202 }
203
204 /* Performance critical */
205 static inline struct ipt_entry *
206 get_entry(void *base, unsigned int offset)
207 {
208 return (struct ipt_entry *)(base + offset);
209 }
210
211 /* All zeroes == unconditional rule. */
212 /* Mildly perf critical (only if packet tracing is on) */
213 static inline int
214 unconditional(const struct ipt_ip *ip)
215 {
216 unsigned int i;
217
218 for (i = 0; i < sizeof(*ip)/sizeof(__u32); i++)
219 if (((__u32 *)ip)[i])
220 return 0;
221
222 return 1;
223 #undef FWINV
224 }
225
226 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
227 defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
228 static const char *const hooknames[] = {
229 [NF_INET_PRE_ROUTING] = "PREROUTING",
230 [NF_INET_LOCAL_IN] = "INPUT",
231 [NF_INET_FORWARD] = "FORWARD",
232 [NF_INET_LOCAL_OUT] = "OUTPUT",
233 [NF_INET_POST_ROUTING] = "POSTROUTING",
234 };
235
236 enum nf_ip_trace_comments {
237 NF_IP_TRACE_COMMENT_RULE,
238 NF_IP_TRACE_COMMENT_RETURN,
239 NF_IP_TRACE_COMMENT_POLICY,
240 };
241
242 static const char *const comments[] = {
243 [NF_IP_TRACE_COMMENT_RULE] = "rule",
244 [NF_IP_TRACE_COMMENT_RETURN] = "return",
245 [NF_IP_TRACE_COMMENT_POLICY] = "policy",
246 };
247
248 static struct nf_loginfo trace_loginfo = {
249 .type = NF_LOG_TYPE_LOG,
250 .u = {
251 .log = {
252 .level = 4,
253 .logflags = NF_LOG_MASK,
254 },
255 },
256 };
257
258 /* Mildly perf critical (only if packet tracing is on) */
259 static inline int
260 get_chainname_rulenum(struct ipt_entry *s, struct ipt_entry *e,
261 char *hookname, char **chainname,
262 char **comment, unsigned int *rulenum)
263 {
264 struct ipt_standard_target *t = (void *)ipt_get_target(s);
265
266 if (strcmp(t->target.u.kernel.target->name, IPT_ERROR_TARGET) == 0) {
267 /* Head of user chain: ERROR target with chainname */
268 *chainname = t->target.data;
269 (*rulenum) = 0;
270 } else if (s == e) {
271 (*rulenum)++;
272
273 if (s->target_offset == sizeof(struct ipt_entry)
274 && strcmp(t->target.u.kernel.target->name,
275 IPT_STANDARD_TARGET) == 0
276 && t->verdict < 0
277 && unconditional(&s->ip)) {
278 /* Tail of chains: STANDARD target (return/policy) */
279 *comment = *chainname == hookname
280 ? (char *)comments[NF_IP_TRACE_COMMENT_POLICY]
281 : (char *)comments[NF_IP_TRACE_COMMENT_RETURN];
282 }
283 return 1;
284 } else
285 (*rulenum)++;
286
287 return 0;
288 }
289
290 static void trace_packet(struct sk_buff *skb,
291 unsigned int hook,
292 const struct net_device *in,
293 const struct net_device *out,
294 const char *tablename,
295 struct xt_table_info *private,
296 struct ipt_entry *e)
297 {
298 void *table_base;
299 struct ipt_entry *root;
300 char *hookname, *chainname, *comment;
301 unsigned int rulenum = 0;
302
303 table_base = (void *)private->entries[smp_processor_id()];
304 root = get_entry(table_base, private->hook_entry[hook]);
305
306 hookname = chainname = (char *)hooknames[hook];
307 comment = (char *)comments[NF_IP_TRACE_COMMENT_RULE];
308
309 IPT_ENTRY_ITERATE(root,
310 private->size - private->hook_entry[hook],
311 get_chainname_rulenum,
312 e, hookname, &chainname, &comment, &rulenum);
313
314 nf_log_packet(AF_INET, hook, skb, in, out, &trace_loginfo,
315 "TRACE: %s:%s:%s:%u ",
316 tablename, chainname, comment, rulenum);
317 }
318 #endif
319
320 /* Returns one of the generic firewall policies, like NF_ACCEPT. */
321 unsigned int
322 ipt_do_table(struct sk_buff *skb,
323 unsigned int hook,
324 const struct net_device *in,
325 const struct net_device *out,
326 struct xt_table *table)
327 {
328 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
329 u_int16_t offset;
330 struct iphdr *ip;
331 u_int16_t datalen;
332 bool hotdrop = false;
333 /* Initializing verdict to NF_DROP keeps gcc happy. */
334 unsigned int verdict = NF_DROP;
335 const char *indev, *outdev;
336 void *table_base;
337 struct ipt_entry *e, *back;
338 struct xt_table_info *private;
339
340 /* Initialization */
341 ip = ip_hdr(skb);
342 datalen = skb->len - ip->ihl * 4;
343 indev = in ? in->name : nulldevname;
344 outdev = out ? out->name : nulldevname;
345 /* We handle fragments by dealing with the first fragment as
346 * if it was a normal packet. All other fragments are treated
347 * normally, except that they will NEVER match rules that ask
348 * things we don't know, ie. tcp syn flag or ports). If the
349 * rule is also a fragment-specific rule, non-fragments won't
350 * match it. */
351 offset = ntohs(ip->frag_off) & IP_OFFSET;
352
353 read_lock_bh(&table->lock);
354 IP_NF_ASSERT(table->valid_hooks & (1 << hook));
355 private = table->private;
356 table_base = (void *)private->entries[smp_processor_id()];
357 e = get_entry(table_base, private->hook_entry[hook]);
358
359 /* For return from builtin chain */
360 back = get_entry(table_base, private->underflow[hook]);
361
362 do {
363 IP_NF_ASSERT(e);
364 IP_NF_ASSERT(back);
365 if (ip_packet_match(ip, indev, outdev, &e->ip, offset)) {
366 struct ipt_entry_target *t;
367
368 if (IPT_MATCH_ITERATE(e, do_match,
369 skb, in, out,
370 offset, &hotdrop) != 0)
371 goto no_match;
372
373 ADD_COUNTER(e->counters, ntohs(ip->tot_len), 1);
374
375 t = ipt_get_target(e);
376 IP_NF_ASSERT(t->u.kernel.target);
377
378 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
379 defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
380 /* The packet is traced: log it */
381 if (unlikely(skb->nf_trace))
382 trace_packet(skb, hook, in, out,
383 table->name, private, e);
384 #endif
385 /* Standard target? */
386 if (!t->u.kernel.target->target) {
387 int v;
388
389 v = ((struct ipt_standard_target *)t)->verdict;
390 if (v < 0) {
391 /* Pop from stack? */
392 if (v != IPT_RETURN) {
393 verdict = (unsigned)(-v) - 1;
394 break;
395 }
396 e = back;
397 back = get_entry(table_base,
398 back->comefrom);
399 continue;
400 }
401 if (table_base + v != (void *)e + e->next_offset
402 && !(e->ip.flags & IPT_F_GOTO)) {
403 /* Save old back ptr in next entry */
404 struct ipt_entry *next
405 = (void *)e + e->next_offset;
406 next->comefrom
407 = (void *)back - table_base;
408 /* set back pointer to next entry */
409 back = next;
410 }
411
412 e = get_entry(table_base, v);
413 } else {
414 /* Targets which reenter must return
415 abs. verdicts */
416 #ifdef CONFIG_NETFILTER_DEBUG
417 ((struct ipt_entry *)table_base)->comefrom
418 = 0xeeeeeeec;
419 #endif
420 verdict = t->u.kernel.target->target(skb,
421 in, out,
422 hook,
423 t->u.kernel.target,
424 t->data);
425
426 #ifdef CONFIG_NETFILTER_DEBUG
427 if (((struct ipt_entry *)table_base)->comefrom
428 != 0xeeeeeeec
429 && verdict == IPT_CONTINUE) {
430 printk("Target %s reentered!\n",
431 t->u.kernel.target->name);
432 verdict = NF_DROP;
433 }
434 ((struct ipt_entry *)table_base)->comefrom
435 = 0x57acc001;
436 #endif
437 /* Target might have changed stuff. */
438 ip = ip_hdr(skb);
439 datalen = skb->len - ip->ihl * 4;
440
441 if (verdict == IPT_CONTINUE)
442 e = (void *)e + e->next_offset;
443 else
444 /* Verdict */
445 break;
446 }
447 } else {
448
449 no_match:
450 e = (void *)e + e->next_offset;
451 }
452 } while (!hotdrop);
453
454 read_unlock_bh(&table->lock);
455
456 #ifdef DEBUG_ALLOW_ALL
457 return NF_ACCEPT;
458 #else
459 if (hotdrop)
460 return NF_DROP;
461 else return verdict;
462 #endif
463 }
464
465 /* Figures out from what hook each rule can be called: returns 0 if
466 there are loops. Puts hook bitmask in comefrom. */
467 static int
468 mark_source_chains(struct xt_table_info *newinfo,
469 unsigned int valid_hooks, void *entry0)
470 {
471 unsigned int hook;
472
473 /* No recursion; use packet counter to save back ptrs (reset
474 to 0 as we leave), and comefrom to save source hook bitmask */
475 for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
476 unsigned int pos = newinfo->hook_entry[hook];
477 struct ipt_entry *e = (struct ipt_entry *)(entry0 + pos);
478
479 if (!(valid_hooks & (1 << hook)))
480 continue;
481
482 /* Set initial back pointer. */
483 e->counters.pcnt = pos;
484
485 for (;;) {
486 struct ipt_standard_target *t
487 = (void *)ipt_get_target(e);
488 int visited = e->comefrom & (1 << hook);
489
490 if (e->comefrom & (1 << NF_INET_NUMHOOKS)) {
491 printk("iptables: loop hook %u pos %u %08X.\n",
492 hook, pos, e->comefrom);
493 return 0;
494 }
495 e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
496
497 /* Unconditional return/END. */
498 if ((e->target_offset == sizeof(struct ipt_entry)
499 && (strcmp(t->target.u.user.name,
500 IPT_STANDARD_TARGET) == 0)
501 && t->verdict < 0
502 && unconditional(&e->ip)) || visited) {
503 unsigned int oldpos, size;
504
505 if (t->verdict < -NF_MAX_VERDICT - 1) {
506 duprintf("mark_source_chains: bad "
507 "negative verdict (%i)\n",
508 t->verdict);
509 return 0;
510 }
511
512 /* Return: backtrack through the last
513 big jump. */
514 do {
515 e->comefrom ^= (1<<NF_INET_NUMHOOKS);
516 #ifdef DEBUG_IP_FIREWALL_USER
517 if (e->comefrom
518 & (1 << NF_INET_NUMHOOKS)) {
519 duprintf("Back unset "
520 "on hook %u "
521 "rule %u\n",
522 hook, pos);
523 }
524 #endif
525 oldpos = pos;
526 pos = e->counters.pcnt;
527 e->counters.pcnt = 0;
528
529 /* We're at the start. */
530 if (pos == oldpos)
531 goto next;
532
533 e = (struct ipt_entry *)
534 (entry0 + pos);
535 } while (oldpos == pos + e->next_offset);
536
537 /* Move along one */
538 size = e->next_offset;
539 e = (struct ipt_entry *)
540 (entry0 + pos + size);
541 e->counters.pcnt = pos;
542 pos += size;
543 } else {
544 int newpos = t->verdict;
545
546 if (strcmp(t->target.u.user.name,
547 IPT_STANDARD_TARGET) == 0
548 && newpos >= 0) {
549 if (newpos > newinfo->size -
550 sizeof(struct ipt_entry)) {
551 duprintf("mark_source_chains: "
552 "bad verdict (%i)\n",
553 newpos);
554 return 0;
555 }
556 /* This a jump; chase it. */
557 duprintf("Jump rule %u -> %u\n",
558 pos, newpos);
559 } else {
560 /* ... this is a fallthru */
561 newpos = pos + e->next_offset;
562 }
563 e = (struct ipt_entry *)
564 (entry0 + newpos);
565 e->counters.pcnt = pos;
566 pos = newpos;
567 }
568 }
569 next:
570 duprintf("Finished chain %u\n", hook);
571 }
572 return 1;
573 }
574
575 static int
576 cleanup_match(struct ipt_entry_match *m, unsigned int *i)
577 {
578 if (i && (*i)-- == 0)
579 return 1;
580
581 if (m->u.kernel.match->destroy)
582 m->u.kernel.match->destroy(m->u.kernel.match, m->data);
583 module_put(m->u.kernel.match->me);
584 return 0;
585 }
586
587 static int
588 check_entry(struct ipt_entry *e, const char *name)
589 {
590 struct ipt_entry_target *t;
591
592 if (!ip_checkentry(&e->ip)) {
593 duprintf("ip_tables: ip check failed %p %s.\n", e, name);
594 return -EINVAL;
595 }
596
597 if (e->target_offset + sizeof(struct ipt_entry_target) >
598 e->next_offset)
599 return -EINVAL;
600
601 t = ipt_get_target(e);
602 if (e->target_offset + t->u.target_size > e->next_offset)
603 return -EINVAL;
604
605 return 0;
606 }
607
608 static int
609 check_match(struct ipt_entry_match *m, const char *name,
610 const struct ipt_ip *ip,
611 unsigned int hookmask, unsigned int *i)
612 {
613 struct xt_match *match;
614 int ret;
615
616 match = m->u.kernel.match;
617 ret = xt_check_match(match, AF_INET, m->u.match_size - sizeof(*m),
618 name, hookmask, ip->proto,
619 ip->invflags & IPT_INV_PROTO);
620 if (!ret && m->u.kernel.match->checkentry
621 && !m->u.kernel.match->checkentry(name, ip, match, m->data,
622 hookmask)) {
623 duprintf("ip_tables: check failed for `%s'.\n",
624 m->u.kernel.match->name);
625 ret = -EINVAL;
626 }
627 if (!ret)
628 (*i)++;
629 return ret;
630 }
631
632 static int
633 find_check_match(struct ipt_entry_match *m,
634 const char *name,
635 const struct ipt_ip *ip,
636 unsigned int hookmask,
637 unsigned int *i)
638 {
639 struct xt_match *match;
640 int ret;
641
642 match = try_then_request_module(xt_find_match(AF_INET, m->u.user.name,
643 m->u.user.revision),
644 "ipt_%s", m->u.user.name);
645 if (IS_ERR(match) || !match) {
646 duprintf("find_check_match: `%s' not found\n", m->u.user.name);
647 return match ? PTR_ERR(match) : -ENOENT;
648 }
649 m->u.kernel.match = match;
650
651 ret = check_match(m, name, ip, hookmask, i);
652 if (ret)
653 goto err;
654
655 return 0;
656 err:
657 module_put(m->u.kernel.match->me);
658 return ret;
659 }
660
661 static int check_target(struct ipt_entry *e, const char *name)
662 {
663 struct ipt_entry_target *t;
664 struct xt_target *target;
665 int ret;
666
667 t = ipt_get_target(e);
668 target = t->u.kernel.target;
669 ret = xt_check_target(target, AF_INET, t->u.target_size - sizeof(*t),
670 name, e->comefrom, e->ip.proto,
671 e->ip.invflags & IPT_INV_PROTO);
672 if (!ret && t->u.kernel.target->checkentry
673 && !t->u.kernel.target->checkentry(name, e, target, t->data,
674 e->comefrom)) {
675 duprintf("ip_tables: check failed for `%s'.\n",
676 t->u.kernel.target->name);
677 ret = -EINVAL;
678 }
679 return ret;
680 }
681
682 static int
683 find_check_entry(struct ipt_entry *e, const char *name, unsigned int size,
684 unsigned int *i)
685 {
686 struct ipt_entry_target *t;
687 struct xt_target *target;
688 int ret;
689 unsigned int j;
690
691 ret = check_entry(e, name);
692 if (ret)
693 return ret;
694
695 j = 0;
696 ret = IPT_MATCH_ITERATE(e, find_check_match, name, &e->ip,
697 e->comefrom, &j);
698 if (ret != 0)
699 goto cleanup_matches;
700
701 t = ipt_get_target(e);
702 target = try_then_request_module(xt_find_target(AF_INET,
703 t->u.user.name,
704 t->u.user.revision),
705 "ipt_%s", t->u.user.name);
706 if (IS_ERR(target) || !target) {
707 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
708 ret = target ? PTR_ERR(target) : -ENOENT;
709 goto cleanup_matches;
710 }
711 t->u.kernel.target = target;
712
713 ret = check_target(e, name);
714 if (ret)
715 goto err;
716
717 (*i)++;
718 return 0;
719 err:
720 module_put(t->u.kernel.target->me);
721 cleanup_matches:
722 IPT_MATCH_ITERATE(e, cleanup_match, &j);
723 return ret;
724 }
725
726 static int
727 check_entry_size_and_hooks(struct ipt_entry *e,
728 struct xt_table_info *newinfo,
729 unsigned char *base,
730 unsigned char *limit,
731 const unsigned int *hook_entries,
732 const unsigned int *underflows,
733 unsigned int *i)
734 {
735 unsigned int h;
736
737 if ((unsigned long)e % __alignof__(struct ipt_entry) != 0
738 || (unsigned char *)e + sizeof(struct ipt_entry) >= limit) {
739 duprintf("Bad offset %p\n", e);
740 return -EINVAL;
741 }
742
743 if (e->next_offset
744 < sizeof(struct ipt_entry) + sizeof(struct ipt_entry_target)) {
745 duprintf("checking: element %p size %u\n",
746 e, e->next_offset);
747 return -EINVAL;
748 }
749
750 /* Check hooks & underflows */
751 for (h = 0; h < NF_INET_NUMHOOKS; h++) {
752 if ((unsigned char *)e - base == hook_entries[h])
753 newinfo->hook_entry[h] = hook_entries[h];
754 if ((unsigned char *)e - base == underflows[h])
755 newinfo->underflow[h] = underflows[h];
756 }
757
758 /* FIXME: underflows must be unconditional, standard verdicts
759 < 0 (not IPT_RETURN). --RR */
760
761 /* Clear counters and comefrom */
762 e->counters = ((struct xt_counters) { 0, 0 });
763 e->comefrom = 0;
764
765 (*i)++;
766 return 0;
767 }
768
769 static int
770 cleanup_entry(struct ipt_entry *e, unsigned int *i)
771 {
772 struct ipt_entry_target *t;
773
774 if (i && (*i)-- == 0)
775 return 1;
776
777 /* Cleanup all matches */
778 IPT_MATCH_ITERATE(e, cleanup_match, NULL);
779 t = ipt_get_target(e);
780 if (t->u.kernel.target->destroy)
781 t->u.kernel.target->destroy(t->u.kernel.target, t->data);
782 module_put(t->u.kernel.target->me);
783 return 0;
784 }
785
786 /* Checks and translates the user-supplied table segment (held in
787 newinfo) */
788 static int
789 translate_table(const char *name,
790 unsigned int valid_hooks,
791 struct xt_table_info *newinfo,
792 void *entry0,
793 unsigned int size,
794 unsigned int number,
795 const unsigned int *hook_entries,
796 const unsigned int *underflows)
797 {
798 unsigned int i;
799 int ret;
800
801 newinfo->size = size;
802 newinfo->number = number;
803
804 /* Init all hooks to impossible value. */
805 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
806 newinfo->hook_entry[i] = 0xFFFFFFFF;
807 newinfo->underflow[i] = 0xFFFFFFFF;
808 }
809
810 duprintf("translate_table: size %u\n", newinfo->size);
811 i = 0;
812 /* Walk through entries, checking offsets. */
813 ret = IPT_ENTRY_ITERATE(entry0, newinfo->size,
814 check_entry_size_and_hooks,
815 newinfo,
816 entry0,
817 entry0 + size,
818 hook_entries, underflows, &i);
819 if (ret != 0)
820 return ret;
821
822 if (i != number) {
823 duprintf("translate_table: %u not %u entries\n",
824 i, number);
825 return -EINVAL;
826 }
827
828 /* Check hooks all assigned */
829 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
830 /* Only hooks which are valid */
831 if (!(valid_hooks & (1 << i)))
832 continue;
833 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
834 duprintf("Invalid hook entry %u %u\n",
835 i, hook_entries[i]);
836 return -EINVAL;
837 }
838 if (newinfo->underflow[i] == 0xFFFFFFFF) {
839 duprintf("Invalid underflow %u %u\n",
840 i, underflows[i]);
841 return -EINVAL;
842 }
843 }
844
845 if (!mark_source_chains(newinfo, valid_hooks, entry0))
846 return -ELOOP;
847
848 /* Finally, each sanity check must pass */
849 i = 0;
850 ret = IPT_ENTRY_ITERATE(entry0, newinfo->size,
851 find_check_entry, name, size, &i);
852
853 if (ret != 0) {
854 IPT_ENTRY_ITERATE(entry0, newinfo->size,
855 cleanup_entry, &i);
856 return ret;
857 }
858
859 /* And one copy for every other CPU */
860 for_each_possible_cpu(i) {
861 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
862 memcpy(newinfo->entries[i], entry0, newinfo->size);
863 }
864
865 return ret;
866 }
867
868 /* Gets counters. */
869 static inline int
870 add_entry_to_counter(const struct ipt_entry *e,
871 struct xt_counters total[],
872 unsigned int *i)
873 {
874 ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
875
876 (*i)++;
877 return 0;
878 }
879
880 static inline int
881 set_entry_to_counter(const struct ipt_entry *e,
882 struct ipt_counters total[],
883 unsigned int *i)
884 {
885 SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
886
887 (*i)++;
888 return 0;
889 }
890
891 static void
892 get_counters(const struct xt_table_info *t,
893 struct xt_counters counters[])
894 {
895 unsigned int cpu;
896 unsigned int i;
897 unsigned int curcpu;
898
899 /* Instead of clearing (by a previous call to memset())
900 * the counters and using adds, we set the counters
901 * with data used by 'current' CPU
902 * We dont care about preemption here.
903 */
904 curcpu = raw_smp_processor_id();
905
906 i = 0;
907 IPT_ENTRY_ITERATE(t->entries[curcpu],
908 t->size,
909 set_entry_to_counter,
910 counters,
911 &i);
912
913 for_each_possible_cpu(cpu) {
914 if (cpu == curcpu)
915 continue;
916 i = 0;
917 IPT_ENTRY_ITERATE(t->entries[cpu],
918 t->size,
919 add_entry_to_counter,
920 counters,
921 &i);
922 }
923 }
924
925 static struct xt_counters * alloc_counters(struct xt_table *table)
926 {
927 unsigned int countersize;
928 struct xt_counters *counters;
929 struct xt_table_info *private = table->private;
930
931 /* We need atomic snapshot of counters: rest doesn't change
932 (other than comefrom, which userspace doesn't care
933 about). */
934 countersize = sizeof(struct xt_counters) * private->number;
935 counters = vmalloc_node(countersize, numa_node_id());
936
937 if (counters == NULL)
938 return ERR_PTR(-ENOMEM);
939
940 /* First, sum counters... */
941 write_lock_bh(&table->lock);
942 get_counters(private, counters);
943 write_unlock_bh(&table->lock);
944
945 return counters;
946 }
947
948 static int
949 copy_entries_to_user(unsigned int total_size,
950 struct xt_table *table,
951 void __user *userptr)
952 {
953 unsigned int off, num;
954 struct ipt_entry *e;
955 struct xt_counters *counters;
956 struct xt_table_info *private = table->private;
957 int ret = 0;
958 void *loc_cpu_entry;
959
960 counters = alloc_counters(table);
961 if (IS_ERR(counters))
962 return PTR_ERR(counters);
963
964 /* choose the copy that is on our node/cpu, ...
965 * This choice is lazy (because current thread is
966 * allowed to migrate to another cpu)
967 */
968 loc_cpu_entry = private->entries[raw_smp_processor_id()];
969 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
970 ret = -EFAULT;
971 goto free_counters;
972 }
973
974 /* FIXME: use iterator macros --RR */
975 /* ... then go back and fix counters and names */
976 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
977 unsigned int i;
978 struct ipt_entry_match *m;
979 struct ipt_entry_target *t;
980
981 e = (struct ipt_entry *)(loc_cpu_entry + off);
982 if (copy_to_user(userptr + off
983 + offsetof(struct ipt_entry, counters),
984 &counters[num],
985 sizeof(counters[num])) != 0) {
986 ret = -EFAULT;
987 goto free_counters;
988 }
989
990 for (i = sizeof(struct ipt_entry);
991 i < e->target_offset;
992 i += m->u.match_size) {
993 m = (void *)e + i;
994
995 if (copy_to_user(userptr + off + i
996 + offsetof(struct ipt_entry_match,
997 u.user.name),
998 m->u.kernel.match->name,
999 strlen(m->u.kernel.match->name)+1)
1000 != 0) {
1001 ret = -EFAULT;
1002 goto free_counters;
1003 }
1004 }
1005
1006 t = ipt_get_target(e);
1007 if (copy_to_user(userptr + off + e->target_offset
1008 + offsetof(struct ipt_entry_target,
1009 u.user.name),
1010 t->u.kernel.target->name,
1011 strlen(t->u.kernel.target->name)+1) != 0) {
1012 ret = -EFAULT;
1013 goto free_counters;
1014 }
1015 }
1016
1017 free_counters:
1018 vfree(counters);
1019 return ret;
1020 }
1021
1022 #ifdef CONFIG_COMPAT
1023 static void compat_standard_from_user(void *dst, void *src)
1024 {
1025 int v = *(compat_int_t *)src;
1026
1027 if (v > 0)
1028 v += xt_compat_calc_jump(AF_INET, v);
1029 memcpy(dst, &v, sizeof(v));
1030 }
1031
1032 static int compat_standard_to_user(void __user *dst, void *src)
1033 {
1034 compat_int_t cv = *(int *)src;
1035
1036 if (cv > 0)
1037 cv -= xt_compat_calc_jump(AF_INET, cv);
1038 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
1039 }
1040
1041 static inline int
1042 compat_calc_match(struct ipt_entry_match *m, int *size)
1043 {
1044 *size += xt_compat_match_offset(m->u.kernel.match);
1045 return 0;
1046 }
1047
1048 static int compat_calc_entry(struct ipt_entry *e,
1049 const struct xt_table_info *info,
1050 void *base, struct xt_table_info *newinfo)
1051 {
1052 struct ipt_entry_target *t;
1053 unsigned int entry_offset;
1054 int off, i, ret;
1055
1056 off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1057 entry_offset = (void *)e - base;
1058 IPT_MATCH_ITERATE(e, compat_calc_match, &off);
1059 t = ipt_get_target(e);
1060 off += xt_compat_target_offset(t->u.kernel.target);
1061 newinfo->size -= off;
1062 ret = xt_compat_add_offset(AF_INET, entry_offset, off);
1063 if (ret)
1064 return ret;
1065
1066 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1067 if (info->hook_entry[i] &&
1068 (e < (struct ipt_entry *)(base + info->hook_entry[i])))
1069 newinfo->hook_entry[i] -= off;
1070 if (info->underflow[i] &&
1071 (e < (struct ipt_entry *)(base + info->underflow[i])))
1072 newinfo->underflow[i] -= off;
1073 }
1074 return 0;
1075 }
1076
1077 static int compat_table_info(const struct xt_table_info *info,
1078 struct xt_table_info *newinfo)
1079 {
1080 void *loc_cpu_entry;
1081
1082 if (!newinfo || !info)
1083 return -EINVAL;
1084
1085 /* we dont care about newinfo->entries[] */
1086 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
1087 newinfo->initial_entries = 0;
1088 loc_cpu_entry = info->entries[raw_smp_processor_id()];
1089 return IPT_ENTRY_ITERATE(loc_cpu_entry, info->size,
1090 compat_calc_entry, info, loc_cpu_entry,
1091 newinfo);
1092 }
1093 #endif
1094
1095 static int get_info(struct net *net, void __user *user, int *len, int compat)
1096 {
1097 char name[IPT_TABLE_MAXNAMELEN];
1098 struct xt_table *t;
1099 int ret;
1100
1101 if (*len != sizeof(struct ipt_getinfo)) {
1102 duprintf("length %u != %zu\n", *len,
1103 sizeof(struct ipt_getinfo));
1104 return -EINVAL;
1105 }
1106
1107 if (copy_from_user(name, user, sizeof(name)) != 0)
1108 return -EFAULT;
1109
1110 name[IPT_TABLE_MAXNAMELEN-1] = '\0';
1111 #ifdef CONFIG_COMPAT
1112 if (compat)
1113 xt_compat_lock(AF_INET);
1114 #endif
1115 t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
1116 "iptable_%s", name);
1117 if (t && !IS_ERR(t)) {
1118 struct ipt_getinfo info;
1119 struct xt_table_info *private = t->private;
1120
1121 #ifdef CONFIG_COMPAT
1122 if (compat) {
1123 struct xt_table_info tmp;
1124 ret = compat_table_info(private, &tmp);
1125 xt_compat_flush_offsets(AF_INET);
1126 private = &tmp;
1127 }
1128 #endif
1129 info.valid_hooks = t->valid_hooks;
1130 memcpy(info.hook_entry, private->hook_entry,
1131 sizeof(info.hook_entry));
1132 memcpy(info.underflow, private->underflow,
1133 sizeof(info.underflow));
1134 info.num_entries = private->number;
1135 info.size = private->size;
1136 strcpy(info.name, name);
1137
1138 if (copy_to_user(user, &info, *len) != 0)
1139 ret = -EFAULT;
1140 else
1141 ret = 0;
1142
1143 xt_table_unlock(t);
1144 module_put(t->me);
1145 } else
1146 ret = t ? PTR_ERR(t) : -ENOENT;
1147 #ifdef CONFIG_COMPAT
1148 if (compat)
1149 xt_compat_unlock(AF_INET);
1150 #endif
1151 return ret;
1152 }
1153
1154 static int
1155 get_entries(struct net *net, struct ipt_get_entries __user *uptr, int *len)
1156 {
1157 int ret;
1158 struct ipt_get_entries get;
1159 struct xt_table *t;
1160
1161 if (*len < sizeof(get)) {
1162 duprintf("get_entries: %u < %zu\n", *len, sizeof(get));
1163 return -EINVAL;
1164 }
1165 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1166 return -EFAULT;
1167 if (*len != sizeof(struct ipt_get_entries) + get.size) {
1168 duprintf("get_entries: %u != %zu\n",
1169 *len, sizeof(get) + get.size);
1170 return -EINVAL;
1171 }
1172
1173 t = xt_find_table_lock(net, AF_INET, get.name);
1174 if (t && !IS_ERR(t)) {
1175 struct xt_table_info *private = t->private;
1176 duprintf("t->private->number = %u\n", private->number);
1177 if (get.size == private->size)
1178 ret = copy_entries_to_user(private->size,
1179 t, uptr->entrytable);
1180 else {
1181 duprintf("get_entries: I've got %u not %u!\n",
1182 private->size, get.size);
1183 ret = -EINVAL;
1184 }
1185 module_put(t->me);
1186 xt_table_unlock(t);
1187 } else
1188 ret = t ? PTR_ERR(t) : -ENOENT;
1189
1190 return ret;
1191 }
1192
1193 static int
1194 __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
1195 struct xt_table_info *newinfo, unsigned int num_counters,
1196 void __user *counters_ptr)
1197 {
1198 int ret;
1199 struct xt_table *t;
1200 struct xt_table_info *oldinfo;
1201 struct xt_counters *counters;
1202 void *loc_cpu_old_entry;
1203
1204 ret = 0;
1205 counters = vmalloc(num_counters * sizeof(struct xt_counters));
1206 if (!counters) {
1207 ret = -ENOMEM;
1208 goto out;
1209 }
1210
1211 t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
1212 "iptable_%s", name);
1213 if (!t || IS_ERR(t)) {
1214 ret = t ? PTR_ERR(t) : -ENOENT;
1215 goto free_newinfo_counters_untrans;
1216 }
1217
1218 /* You lied! */
1219 if (valid_hooks != t->valid_hooks) {
1220 duprintf("Valid hook crap: %08X vs %08X\n",
1221 valid_hooks, t->valid_hooks);
1222 ret = -EINVAL;
1223 goto put_module;
1224 }
1225
1226 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1227 if (!oldinfo)
1228 goto put_module;
1229
1230 /* Update module usage count based on number of rules */
1231 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1232 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1233 if ((oldinfo->number > oldinfo->initial_entries) ||
1234 (newinfo->number <= oldinfo->initial_entries))
1235 module_put(t->me);
1236 if ((oldinfo->number > oldinfo->initial_entries) &&
1237 (newinfo->number <= oldinfo->initial_entries))
1238 module_put(t->me);
1239
1240 /* Get the old counters. */
1241 get_counters(oldinfo, counters);
1242 /* Decrease module usage counts and free resource */
1243 loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1244 IPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,
1245 NULL);
1246 xt_free_table_info(oldinfo);
1247 if (copy_to_user(counters_ptr, counters,
1248 sizeof(struct xt_counters) * num_counters) != 0)
1249 ret = -EFAULT;
1250 vfree(counters);
1251 xt_table_unlock(t);
1252 return ret;
1253
1254 put_module:
1255 module_put(t->me);
1256 xt_table_unlock(t);
1257 free_newinfo_counters_untrans:
1258 vfree(counters);
1259 out:
1260 return ret;
1261 }
1262
1263 static int
1264 do_replace(struct net *net, void __user *user, unsigned int len)
1265 {
1266 int ret;
1267 struct ipt_replace tmp;
1268 struct xt_table_info *newinfo;
1269 void *loc_cpu_entry;
1270
1271 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1272 return -EFAULT;
1273
1274 /* overflow check */
1275 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1276 return -ENOMEM;
1277
1278 newinfo = xt_alloc_table_info(tmp.size);
1279 if (!newinfo)
1280 return -ENOMEM;
1281
1282 /* choose the copy that is on our node/cpu */
1283 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1284 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1285 tmp.size) != 0) {
1286 ret = -EFAULT;
1287 goto free_newinfo;
1288 }
1289
1290 ret = translate_table(tmp.name, tmp.valid_hooks,
1291 newinfo, loc_cpu_entry, tmp.size, tmp.num_entries,
1292 tmp.hook_entry, tmp.underflow);
1293 if (ret != 0)
1294 goto free_newinfo;
1295
1296 duprintf("ip_tables: Translated table\n");
1297
1298 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1299 tmp.num_counters, tmp.counters);
1300 if (ret)
1301 goto free_newinfo_untrans;
1302 return 0;
1303
1304 free_newinfo_untrans:
1305 IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
1306 free_newinfo:
1307 xt_free_table_info(newinfo);
1308 return ret;
1309 }
1310
1311 /* We're lazy, and add to the first CPU; overflow works its fey magic
1312 * and everything is OK. */
1313 static int
1314 add_counter_to_entry(struct ipt_entry *e,
1315 const struct xt_counters addme[],
1316 unsigned int *i)
1317 {
1318 #if 0
1319 duprintf("add_counter: Entry %u %lu/%lu + %lu/%lu\n",
1320 *i,
1321 (long unsigned int)e->counters.pcnt,
1322 (long unsigned int)e->counters.bcnt,
1323 (long unsigned int)addme[*i].pcnt,
1324 (long unsigned int)addme[*i].bcnt);
1325 #endif
1326
1327 ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
1328
1329 (*i)++;
1330 return 0;
1331 }
1332
1333 static int
1334 do_add_counters(struct net *net, void __user *user, unsigned int len, int compat)
1335 {
1336 unsigned int i;
1337 struct xt_counters_info tmp;
1338 struct xt_counters *paddc;
1339 unsigned int num_counters;
1340 char *name;
1341 int size;
1342 void *ptmp;
1343 struct xt_table *t;
1344 struct xt_table_info *private;
1345 int ret = 0;
1346 void *loc_cpu_entry;
1347 #ifdef CONFIG_COMPAT
1348 struct compat_xt_counters_info compat_tmp;
1349
1350 if (compat) {
1351 ptmp = &compat_tmp;
1352 size = sizeof(struct compat_xt_counters_info);
1353 } else
1354 #endif
1355 {
1356 ptmp = &tmp;
1357 size = sizeof(struct xt_counters_info);
1358 }
1359
1360 if (copy_from_user(ptmp, user, size) != 0)
1361 return -EFAULT;
1362
1363 #ifdef CONFIG_COMPAT
1364 if (compat) {
1365 num_counters = compat_tmp.num_counters;
1366 name = compat_tmp.name;
1367 } else
1368 #endif
1369 {
1370 num_counters = tmp.num_counters;
1371 name = tmp.name;
1372 }
1373
1374 if (len != size + num_counters * sizeof(struct xt_counters))
1375 return -EINVAL;
1376
1377 paddc = vmalloc_node(len - size, numa_node_id());
1378 if (!paddc)
1379 return -ENOMEM;
1380
1381 if (copy_from_user(paddc, user + size, len - size) != 0) {
1382 ret = -EFAULT;
1383 goto free;
1384 }
1385
1386 t = xt_find_table_lock(net, AF_INET, name);
1387 if (!t || IS_ERR(t)) {
1388 ret = t ? PTR_ERR(t) : -ENOENT;
1389 goto free;
1390 }
1391
1392 write_lock_bh(&t->lock);
1393 private = t->private;
1394 if (private->number != num_counters) {
1395 ret = -EINVAL;
1396 goto unlock_up_free;
1397 }
1398
1399 i = 0;
1400 /* Choose the copy that is on our node */
1401 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1402 IPT_ENTRY_ITERATE(loc_cpu_entry,
1403 private->size,
1404 add_counter_to_entry,
1405 paddc,
1406 &i);
1407 unlock_up_free:
1408 write_unlock_bh(&t->lock);
1409 xt_table_unlock(t);
1410 module_put(t->me);
1411 free:
1412 vfree(paddc);
1413
1414 return ret;
1415 }
1416
1417 #ifdef CONFIG_COMPAT
1418 struct compat_ipt_replace {
1419 char name[IPT_TABLE_MAXNAMELEN];
1420 u32 valid_hooks;
1421 u32 num_entries;
1422 u32 size;
1423 u32 hook_entry[NF_INET_NUMHOOKS];
1424 u32 underflow[NF_INET_NUMHOOKS];
1425 u32 num_counters;
1426 compat_uptr_t counters; /* struct ipt_counters * */
1427 struct compat_ipt_entry entries[0];
1428 };
1429
1430 static int
1431 compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr,
1432 unsigned int *size, struct xt_counters *counters,
1433 unsigned int *i)
1434 {
1435 struct ipt_entry_target *t;
1436 struct compat_ipt_entry __user *ce;
1437 u_int16_t target_offset, next_offset;
1438 compat_uint_t origsize;
1439 int ret;
1440
1441 ret = -EFAULT;
1442 origsize = *size;
1443 ce = (struct compat_ipt_entry __user *)*dstptr;
1444 if (copy_to_user(ce, e, sizeof(struct ipt_entry)))
1445 goto out;
1446
1447 if (copy_to_user(&ce->counters, &counters[*i], sizeof(counters[*i])))
1448 goto out;
1449
1450 *dstptr += sizeof(struct compat_ipt_entry);
1451 *size -= sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1452
1453 ret = IPT_MATCH_ITERATE(e, xt_compat_match_to_user, dstptr, size);
1454 target_offset = e->target_offset - (origsize - *size);
1455 if (ret)
1456 goto out;
1457 t = ipt_get_target(e);
1458 ret = xt_compat_target_to_user(t, dstptr, size);
1459 if (ret)
1460 goto out;
1461 ret = -EFAULT;
1462 next_offset = e->next_offset - (origsize - *size);
1463 if (put_user(target_offset, &ce->target_offset))
1464 goto out;
1465 if (put_user(next_offset, &ce->next_offset))
1466 goto out;
1467
1468 (*i)++;
1469 return 0;
1470 out:
1471 return ret;
1472 }
1473
1474 static int
1475 compat_find_calc_match(struct ipt_entry_match *m,
1476 const char *name,
1477 const struct ipt_ip *ip,
1478 unsigned int hookmask,
1479 int *size, unsigned int *i)
1480 {
1481 struct xt_match *match;
1482
1483 match = try_then_request_module(xt_find_match(AF_INET, m->u.user.name,
1484 m->u.user.revision),
1485 "ipt_%s", m->u.user.name);
1486 if (IS_ERR(match) || !match) {
1487 duprintf("compat_check_calc_match: `%s' not found\n",
1488 m->u.user.name);
1489 return match ? PTR_ERR(match) : -ENOENT;
1490 }
1491 m->u.kernel.match = match;
1492 *size += xt_compat_match_offset(match);
1493
1494 (*i)++;
1495 return 0;
1496 }
1497
1498 static int
1499 compat_release_match(struct ipt_entry_match *m, unsigned int *i)
1500 {
1501 if (i && (*i)-- == 0)
1502 return 1;
1503
1504 module_put(m->u.kernel.match->me);
1505 return 0;
1506 }
1507
1508 static int
1509 compat_release_entry(struct compat_ipt_entry *e, unsigned int *i)
1510 {
1511 struct ipt_entry_target *t;
1512
1513 if (i && (*i)-- == 0)
1514 return 1;
1515
1516 /* Cleanup all matches */
1517 COMPAT_IPT_MATCH_ITERATE(e, compat_release_match, NULL);
1518 t = compat_ipt_get_target(e);
1519 module_put(t->u.kernel.target->me);
1520 return 0;
1521 }
1522
1523 static int
1524 check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
1525 struct xt_table_info *newinfo,
1526 unsigned int *size,
1527 unsigned char *base,
1528 unsigned char *limit,
1529 unsigned int *hook_entries,
1530 unsigned int *underflows,
1531 unsigned int *i,
1532 const char *name)
1533 {
1534 struct ipt_entry_target *t;
1535 struct xt_target *target;
1536 unsigned int entry_offset;
1537 unsigned int j;
1538 int ret, off, h;
1539
1540 duprintf("check_compat_entry_size_and_hooks %p\n", e);
1541 if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0
1542 || (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit) {
1543 duprintf("Bad offset %p, limit = %p\n", e, limit);
1544 return -EINVAL;
1545 }
1546
1547 if (e->next_offset < sizeof(struct compat_ipt_entry) +
1548 sizeof(struct compat_xt_entry_target)) {
1549 duprintf("checking: element %p size %u\n",
1550 e, e->next_offset);
1551 return -EINVAL;
1552 }
1553
1554 /* For purposes of check_entry casting the compat entry is fine */
1555 ret = check_entry((struct ipt_entry *)e, name);
1556 if (ret)
1557 return ret;
1558
1559 off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1560 entry_offset = (void *)e - (void *)base;
1561 j = 0;
1562 ret = COMPAT_IPT_MATCH_ITERATE(e, compat_find_calc_match, name,
1563 &e->ip, e->comefrom, &off, &j);
1564 if (ret != 0)
1565 goto release_matches;
1566
1567 t = compat_ipt_get_target(e);
1568 target = try_then_request_module(xt_find_target(AF_INET,
1569 t->u.user.name,
1570 t->u.user.revision),
1571 "ipt_%s", t->u.user.name);
1572 if (IS_ERR(target) || !target) {
1573 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1574 t->u.user.name);
1575 ret = target ? PTR_ERR(target) : -ENOENT;
1576 goto release_matches;
1577 }
1578 t->u.kernel.target = target;
1579
1580 off += xt_compat_target_offset(target);
1581 *size += off;
1582 ret = xt_compat_add_offset(AF_INET, entry_offset, off);
1583 if (ret)
1584 goto out;
1585
1586 /* Check hooks & underflows */
1587 for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1588 if ((unsigned char *)e - base == hook_entries[h])
1589 newinfo->hook_entry[h] = hook_entries[h];
1590 if ((unsigned char *)e - base == underflows[h])
1591 newinfo->underflow[h] = underflows[h];
1592 }
1593
1594 /* Clear counters and comefrom */
1595 memset(&e->counters, 0, sizeof(e->counters));
1596 e->comefrom = 0;
1597
1598 (*i)++;
1599 return 0;
1600
1601 out:
1602 module_put(t->u.kernel.target->me);
1603 release_matches:
1604 IPT_MATCH_ITERATE(e, compat_release_match, &j);
1605 return ret;
1606 }
1607
1608 static int
1609 compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
1610 unsigned int *size, const char *name,
1611 struct xt_table_info *newinfo, unsigned char *base)
1612 {
1613 struct ipt_entry_target *t;
1614 struct xt_target *target;
1615 struct ipt_entry *de;
1616 unsigned int origsize;
1617 int ret, h;
1618
1619 ret = 0;
1620 origsize = *size;
1621 de = (struct ipt_entry *)*dstptr;
1622 memcpy(de, e, sizeof(struct ipt_entry));
1623 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1624
1625 *dstptr += sizeof(struct ipt_entry);
1626 *size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1627
1628 ret = COMPAT_IPT_MATCH_ITERATE(e, xt_compat_match_from_user,
1629 dstptr, size);
1630 if (ret)
1631 return ret;
1632 de->target_offset = e->target_offset - (origsize - *size);
1633 t = compat_ipt_get_target(e);
1634 target = t->u.kernel.target;
1635 xt_compat_target_from_user(t, dstptr, size);
1636
1637 de->next_offset = e->next_offset - (origsize - *size);
1638 for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1639 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1640 newinfo->hook_entry[h] -= origsize - *size;
1641 if ((unsigned char *)de - base < newinfo->underflow[h])
1642 newinfo->underflow[h] -= origsize - *size;
1643 }
1644 return ret;
1645 }
1646
1647 static int
1648 compat_check_entry(struct ipt_entry *e, const char *name,
1649 unsigned int *i)
1650 {
1651 unsigned int j;
1652 int ret;
1653
1654 j = 0;
1655 ret = IPT_MATCH_ITERATE(e, check_match, name, &e->ip,
1656 e->comefrom, &j);
1657 if (ret)
1658 goto cleanup_matches;
1659
1660 ret = check_target(e, name);
1661 if (ret)
1662 goto cleanup_matches;
1663
1664 (*i)++;
1665 return 0;
1666
1667 cleanup_matches:
1668 IPT_MATCH_ITERATE(e, cleanup_match, &j);
1669 return ret;
1670 }
1671
1672 static int
1673 translate_compat_table(const char *name,
1674 unsigned int valid_hooks,
1675 struct xt_table_info **pinfo,
1676 void **pentry0,
1677 unsigned int total_size,
1678 unsigned int number,
1679 unsigned int *hook_entries,
1680 unsigned int *underflows)
1681 {
1682 unsigned int i, j;
1683 struct xt_table_info *newinfo, *info;
1684 void *pos, *entry0, *entry1;
1685 unsigned int size;
1686 int ret;
1687
1688 info = *pinfo;
1689 entry0 = *pentry0;
1690 size = total_size;
1691 info->number = number;
1692
1693 /* Init all hooks to impossible value. */
1694 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1695 info->hook_entry[i] = 0xFFFFFFFF;
1696 info->underflow[i] = 0xFFFFFFFF;
1697 }
1698
1699 duprintf("translate_compat_table: size %u\n", info->size);
1700 j = 0;
1701 xt_compat_lock(AF_INET);
1702 /* Walk through entries, checking offsets. */
1703 ret = COMPAT_IPT_ENTRY_ITERATE(entry0, total_size,
1704 check_compat_entry_size_and_hooks,
1705 info, &size, entry0,
1706 entry0 + total_size,
1707 hook_entries, underflows, &j, name);
1708 if (ret != 0)
1709 goto out_unlock;
1710
1711 ret = -EINVAL;
1712 if (j != number) {
1713 duprintf("translate_compat_table: %u not %u entries\n",
1714 j, number);
1715 goto out_unlock;
1716 }
1717
1718 /* Check hooks all assigned */
1719 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1720 /* Only hooks which are valid */
1721 if (!(valid_hooks & (1 << i)))
1722 continue;
1723 if (info->hook_entry[i] == 0xFFFFFFFF) {
1724 duprintf("Invalid hook entry %u %u\n",
1725 i, hook_entries[i]);
1726 goto out_unlock;
1727 }
1728 if (info->underflow[i] == 0xFFFFFFFF) {
1729 duprintf("Invalid underflow %u %u\n",
1730 i, underflows[i]);
1731 goto out_unlock;
1732 }
1733 }
1734
1735 ret = -ENOMEM;
1736 newinfo = xt_alloc_table_info(size);
1737 if (!newinfo)
1738 goto out_unlock;
1739
1740 newinfo->number = number;
1741 for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1742 newinfo->hook_entry[i] = info->hook_entry[i];
1743 newinfo->underflow[i] = info->underflow[i];
1744 }
1745 entry1 = newinfo->entries[raw_smp_processor_id()];
1746 pos = entry1;
1747 size = total_size;
1748 ret = COMPAT_IPT_ENTRY_ITERATE(entry0, total_size,
1749 compat_copy_entry_from_user,
1750 &pos, &size, name, newinfo, entry1);
1751 xt_compat_flush_offsets(AF_INET);
1752 xt_compat_unlock(AF_INET);
1753 if (ret)
1754 goto free_newinfo;
1755
1756 ret = -ELOOP;
1757 if (!mark_source_chains(newinfo, valid_hooks, entry1))
1758 goto free_newinfo;
1759
1760 i = 0;
1761 ret = IPT_ENTRY_ITERATE(entry1, newinfo->size, compat_check_entry,
1762 name, &i);
1763 if (ret) {
1764 j -= i;
1765 COMPAT_IPT_ENTRY_ITERATE_CONTINUE(entry0, newinfo->size, i,
1766 compat_release_entry, &j);
1767 IPT_ENTRY_ITERATE(entry1, newinfo->size, cleanup_entry, &i);
1768 xt_free_table_info(newinfo);
1769 return ret;
1770 }
1771
1772 /* And one copy for every other CPU */
1773 for_each_possible_cpu(i)
1774 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1775 memcpy(newinfo->entries[i], entry1, newinfo->size);
1776
1777 *pinfo = newinfo;
1778 *pentry0 = entry1;
1779 xt_free_table_info(info);
1780 return 0;
1781
1782 free_newinfo:
1783 xt_free_table_info(newinfo);
1784 out:
1785 COMPAT_IPT_ENTRY_ITERATE(entry0, total_size, compat_release_entry, &j);
1786 return ret;
1787 out_unlock:
1788 xt_compat_flush_offsets(AF_INET);
1789 xt_compat_unlock(AF_INET);
1790 goto out;
1791 }
1792
1793 static int
1794 compat_do_replace(struct net *net, void __user *user, unsigned int len)
1795 {
1796 int ret;
1797 struct compat_ipt_replace tmp;
1798 struct xt_table_info *newinfo;
1799 void *loc_cpu_entry;
1800
1801 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1802 return -EFAULT;
1803
1804 /* overflow check */
1805 if (tmp.size >= INT_MAX / num_possible_cpus())
1806 return -ENOMEM;
1807 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1808 return -ENOMEM;
1809
1810 newinfo = xt_alloc_table_info(tmp.size);
1811 if (!newinfo)
1812 return -ENOMEM;
1813
1814 /* choose the copy that is on our node/cpu */
1815 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1816 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1817 tmp.size) != 0) {
1818 ret = -EFAULT;
1819 goto free_newinfo;
1820 }
1821
1822 ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1823 &newinfo, &loc_cpu_entry, tmp.size,
1824 tmp.num_entries, tmp.hook_entry,
1825 tmp.underflow);
1826 if (ret != 0)
1827 goto free_newinfo;
1828
1829 duprintf("compat_do_replace: Translated table\n");
1830
1831 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1832 tmp.num_counters, compat_ptr(tmp.counters));
1833 if (ret)
1834 goto free_newinfo_untrans;
1835 return 0;
1836
1837 free_newinfo_untrans:
1838 IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
1839 free_newinfo:
1840 xt_free_table_info(newinfo);
1841 return ret;
1842 }
1843
1844 static int
1845 compat_do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user,
1846 unsigned int len)
1847 {
1848 int ret;
1849
1850 if (!capable(CAP_NET_ADMIN))
1851 return -EPERM;
1852
1853 switch (cmd) {
1854 case IPT_SO_SET_REPLACE:
1855 ret = compat_do_replace(sk->sk_net, user, len);
1856 break;
1857
1858 case IPT_SO_SET_ADD_COUNTERS:
1859 ret = do_add_counters(sk->sk_net, user, len, 1);
1860 break;
1861
1862 default:
1863 duprintf("do_ipt_set_ctl: unknown request %i\n", cmd);
1864 ret = -EINVAL;
1865 }
1866
1867 return ret;
1868 }
1869
1870 struct compat_ipt_get_entries {
1871 char name[IPT_TABLE_MAXNAMELEN];
1872 compat_uint_t size;
1873 struct compat_ipt_entry entrytable[0];
1874 };
1875
1876 static int
1877 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
1878 void __user *userptr)
1879 {
1880 struct xt_counters *counters;
1881 struct xt_table_info *private = table->private;
1882 void __user *pos;
1883 unsigned int size;
1884 int ret = 0;
1885 void *loc_cpu_entry;
1886 unsigned int i = 0;
1887
1888 counters = alloc_counters(table);
1889 if (IS_ERR(counters))
1890 return PTR_ERR(counters);
1891
1892 /* choose the copy that is on our node/cpu, ...
1893 * This choice is lazy (because current thread is
1894 * allowed to migrate to another cpu)
1895 */
1896 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1897 pos = userptr;
1898 size = total_size;
1899 ret = IPT_ENTRY_ITERATE(loc_cpu_entry, total_size,
1900 compat_copy_entry_to_user,
1901 &pos, &size, counters, &i);
1902
1903 vfree(counters);
1904 return ret;
1905 }
1906
1907 static int
1908 compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr,
1909 int *len)
1910 {
1911 int ret;
1912 struct compat_ipt_get_entries get;
1913 struct xt_table *t;
1914
1915 if (*len < sizeof(get)) {
1916 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1917 return -EINVAL;
1918 }
1919
1920 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1921 return -EFAULT;
1922
1923 if (*len != sizeof(struct compat_ipt_get_entries) + get.size) {
1924 duprintf("compat_get_entries: %u != %zu\n",
1925 *len, sizeof(get) + get.size);
1926 return -EINVAL;
1927 }
1928
1929 xt_compat_lock(AF_INET);
1930 t = xt_find_table_lock(net, AF_INET, get.name);
1931 if (t && !IS_ERR(t)) {
1932 struct xt_table_info *private = t->private;
1933 struct xt_table_info info;
1934 duprintf("t->private->number = %u\n", private->number);
1935 ret = compat_table_info(private, &info);
1936 if (!ret && get.size == info.size) {
1937 ret = compat_copy_entries_to_user(private->size,
1938 t, uptr->entrytable);
1939 } else if (!ret) {
1940 duprintf("compat_get_entries: I've got %u not %u!\n",
1941 private->size, get.size);
1942 ret = -EINVAL;
1943 }
1944 xt_compat_flush_offsets(AF_INET);
1945 module_put(t->me);
1946 xt_table_unlock(t);
1947 } else
1948 ret = t ? PTR_ERR(t) : -ENOENT;
1949
1950 xt_compat_unlock(AF_INET);
1951 return ret;
1952 }
1953
1954 static int do_ipt_get_ctl(struct sock *, int, void __user *, int *);
1955
1956 static int
1957 compat_do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1958 {
1959 int ret;
1960
1961 if (!capable(CAP_NET_ADMIN))
1962 return -EPERM;
1963
1964 switch (cmd) {
1965 case IPT_SO_GET_INFO:
1966 ret = get_info(sk->sk_net, user, len, 1);
1967 break;
1968 case IPT_SO_GET_ENTRIES:
1969 ret = compat_get_entries(sk->sk_net, user, len);
1970 break;
1971 default:
1972 ret = do_ipt_get_ctl(sk, cmd, user, len);
1973 }
1974 return ret;
1975 }
1976 #endif
1977
1978 static int
1979 do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1980 {
1981 int ret;
1982
1983 if (!capable(CAP_NET_ADMIN))
1984 return -EPERM;
1985
1986 switch (cmd) {
1987 case IPT_SO_SET_REPLACE:
1988 ret = do_replace(sk->sk_net, user, len);
1989 break;
1990
1991 case IPT_SO_SET_ADD_COUNTERS:
1992 ret = do_add_counters(sk->sk_net, user, len, 0);
1993 break;
1994
1995 default:
1996 duprintf("do_ipt_set_ctl: unknown request %i\n", cmd);
1997 ret = -EINVAL;
1998 }
1999
2000 return ret;
2001 }
2002
2003 static int
2004 do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
2005 {
2006 int ret;
2007
2008 if (!capable(CAP_NET_ADMIN))
2009 return -EPERM;
2010
2011 switch (cmd) {
2012 case IPT_SO_GET_INFO:
2013 ret = get_info(sk->sk_net, user, len, 0);
2014 break;
2015
2016 case IPT_SO_GET_ENTRIES:
2017 ret = get_entries(sk->sk_net, user, len);
2018 break;
2019
2020 case IPT_SO_GET_REVISION_MATCH:
2021 case IPT_SO_GET_REVISION_TARGET: {
2022 struct ipt_get_revision rev;
2023 int target;
2024
2025 if (*len != sizeof(rev)) {
2026 ret = -EINVAL;
2027 break;
2028 }
2029 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
2030 ret = -EFAULT;
2031 break;
2032 }
2033
2034 if (cmd == IPT_SO_GET_REVISION_TARGET)
2035 target = 1;
2036 else
2037 target = 0;
2038
2039 try_then_request_module(xt_find_revision(AF_INET, rev.name,
2040 rev.revision,
2041 target, &ret),
2042 "ipt_%s", rev.name);
2043 break;
2044 }
2045
2046 default:
2047 duprintf("do_ipt_get_ctl: unknown request %i\n", cmd);
2048 ret = -EINVAL;
2049 }
2050
2051 return ret;
2052 }
2053
2054 struct xt_table *ipt_register_table(struct net *net, struct xt_table *table,
2055 const struct ipt_replace *repl)
2056 {
2057 int ret;
2058 struct xt_table_info *newinfo;
2059 struct xt_table_info bootstrap
2060 = { 0, 0, 0, { 0 }, { 0 }, { } };
2061 void *loc_cpu_entry;
2062 struct xt_table *new_table;
2063
2064 newinfo = xt_alloc_table_info(repl->size);
2065 if (!newinfo) {
2066 ret = -ENOMEM;
2067 goto out;
2068 }
2069
2070 /* choose the copy on our node/cpu, but dont care about preemption */
2071 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
2072 memcpy(loc_cpu_entry, repl->entries, repl->size);
2073
2074 ret = translate_table(table->name, table->valid_hooks,
2075 newinfo, loc_cpu_entry, repl->size,
2076 repl->num_entries,
2077 repl->hook_entry,
2078 repl->underflow);
2079 if (ret != 0)
2080 goto out_free;
2081
2082 new_table = xt_register_table(net, table, &bootstrap, newinfo);
2083 if (IS_ERR(new_table)) {
2084 ret = PTR_ERR(new_table);
2085 goto out_free;
2086 }
2087
2088 return new_table;
2089
2090 out_free:
2091 xt_free_table_info(newinfo);
2092 out:
2093 return ERR_PTR(ret);
2094 }
2095
2096 void ipt_unregister_table(struct xt_table *table)
2097 {
2098 struct xt_table_info *private;
2099 void *loc_cpu_entry;
2100 struct module *table_owner = table->me;
2101
2102 private = xt_unregister_table(table);
2103
2104 /* Decrease module usage counts and free resources */
2105 loc_cpu_entry = private->entries[raw_smp_processor_id()];
2106 IPT_ENTRY_ITERATE(loc_cpu_entry, private->size, cleanup_entry, NULL);
2107 if (private->number > private->initial_entries)
2108 module_put(table_owner);
2109 xt_free_table_info(private);
2110 }
2111
2112 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
2113 static inline bool
2114 icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
2115 u_int8_t type, u_int8_t code,
2116 bool invert)
2117 {
2118 return ((test_type == 0xFF) ||
2119 (type == test_type && code >= min_code && code <= max_code))
2120 ^ invert;
2121 }
2122
2123 static bool
2124 icmp_match(const struct sk_buff *skb,
2125 const struct net_device *in,
2126 const struct net_device *out,
2127 const struct xt_match *match,
2128 const void *matchinfo,
2129 int offset,
2130 unsigned int protoff,
2131 bool *hotdrop)
2132 {
2133 struct icmphdr _icmph, *ic;
2134 const struct ipt_icmp *icmpinfo = matchinfo;
2135
2136 /* Must not be a fragment. */
2137 if (offset)
2138 return false;
2139
2140 ic = skb_header_pointer(skb, protoff, sizeof(_icmph), &_icmph);
2141 if (ic == NULL) {
2142 /* We've been asked to examine this packet, and we
2143 * can't. Hence, no choice but to drop.
2144 */
2145 duprintf("Dropping evil ICMP tinygram.\n");
2146 *hotdrop = true;
2147 return false;
2148 }
2149
2150 return icmp_type_code_match(icmpinfo->type,
2151 icmpinfo->code[0],
2152 icmpinfo->code[1],
2153 ic->type, ic->code,
2154 !!(icmpinfo->invflags&IPT_ICMP_INV));
2155 }
2156
2157 /* Called when user tries to insert an entry of this type. */
2158 static bool
2159 icmp_checkentry(const char *tablename,
2160 const void *entry,
2161 const struct xt_match *match,
2162 void *matchinfo,
2163 unsigned int hook_mask)
2164 {
2165 const struct ipt_icmp *icmpinfo = matchinfo;
2166
2167 /* Must specify no unknown invflags */
2168 return !(icmpinfo->invflags & ~IPT_ICMP_INV);
2169 }
2170
2171 /* The built-in targets: standard (NULL) and error. */
2172 static struct xt_target ipt_standard_target __read_mostly = {
2173 .name = IPT_STANDARD_TARGET,
2174 .targetsize = sizeof(int),
2175 .family = AF_INET,
2176 #ifdef CONFIG_COMPAT
2177 .compatsize = sizeof(compat_int_t),
2178 .compat_from_user = compat_standard_from_user,
2179 .compat_to_user = compat_standard_to_user,
2180 #endif
2181 };
2182
2183 static struct xt_target ipt_error_target __read_mostly = {
2184 .name = IPT_ERROR_TARGET,
2185 .target = ipt_error,
2186 .targetsize = IPT_FUNCTION_MAXNAMELEN,
2187 .family = AF_INET,
2188 };
2189
2190 static struct nf_sockopt_ops ipt_sockopts = {
2191 .pf = PF_INET,
2192 .set_optmin = IPT_BASE_CTL,
2193 .set_optmax = IPT_SO_SET_MAX+1,
2194 .set = do_ipt_set_ctl,
2195 #ifdef CONFIG_COMPAT
2196 .compat_set = compat_do_ipt_set_ctl,
2197 #endif
2198 .get_optmin = IPT_BASE_CTL,
2199 .get_optmax = IPT_SO_GET_MAX+1,
2200 .get = do_ipt_get_ctl,
2201 #ifdef CONFIG_COMPAT
2202 .compat_get = compat_do_ipt_get_ctl,
2203 #endif
2204 .owner = THIS_MODULE,
2205 };
2206
2207 static struct xt_match icmp_matchstruct __read_mostly = {
2208 .name = "icmp",
2209 .match = icmp_match,
2210 .matchsize = sizeof(struct ipt_icmp),
2211 .checkentry = icmp_checkentry,
2212 .proto = IPPROTO_ICMP,
2213 .family = AF_INET,
2214 };
2215
2216 static int __net_init ip_tables_net_init(struct net *net)
2217 {
2218 return xt_proto_init(net, AF_INET);
2219 }
2220
2221 static void __net_exit ip_tables_net_exit(struct net *net)
2222 {
2223 xt_proto_fini(net, AF_INET);
2224 }
2225
2226 static struct pernet_operations ip_tables_net_ops = {
2227 .init = ip_tables_net_init,
2228 .exit = ip_tables_net_exit,
2229 };
2230
2231 static int __init ip_tables_init(void)
2232 {
2233 int ret;
2234
2235 ret = register_pernet_subsys(&ip_tables_net_ops);
2236 if (ret < 0)
2237 goto err1;
2238
2239 /* Noone else will be downing sem now, so we won't sleep */
2240 ret = xt_register_target(&ipt_standard_target);
2241 if (ret < 0)
2242 goto err2;
2243 ret = xt_register_target(&ipt_error_target);
2244 if (ret < 0)
2245 goto err3;
2246 ret = xt_register_match(&icmp_matchstruct);
2247 if (ret < 0)
2248 goto err4;
2249
2250 /* Register setsockopt */
2251 ret = nf_register_sockopt(&ipt_sockopts);
2252 if (ret < 0)
2253 goto err5;
2254
2255 printk(KERN_INFO "ip_tables: (C) 2000-2006 Netfilter Core Team\n");
2256 return 0;
2257
2258 err5:
2259 xt_unregister_match(&icmp_matchstruct);
2260 err4:
2261 xt_unregister_target(&ipt_error_target);
2262 err3:
2263 xt_unregister_target(&ipt_standard_target);
2264 err2:
2265 unregister_pernet_subsys(&ip_tables_net_ops);
2266 err1:
2267 return ret;
2268 }
2269
2270 static void __exit ip_tables_fini(void)
2271 {
2272 nf_unregister_sockopt(&ipt_sockopts);
2273
2274 xt_unregister_match(&icmp_matchstruct);
2275 xt_unregister_target(&ipt_error_target);
2276 xt_unregister_target(&ipt_standard_target);
2277
2278 unregister_pernet_subsys(&ip_tables_net_ops);
2279 }
2280
2281 EXPORT_SYMBOL(ipt_register_table);
2282 EXPORT_SYMBOL(ipt_unregister_table);
2283 EXPORT_SYMBOL(ipt_do_table);
2284 module_init(ip_tables_init);
2285 module_exit(ip_tables_fini);
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