Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * ebtables | |
3 | * | |
4 | * Author: | |
5 | * Bart De Schuymer <bdschuym@pandora.be> | |
6 | * | |
7 | * ebtables.c,v 2.0, July, 2002 | |
8 | * | |
9 | * This code is stongly inspired on the iptables code which is | |
10 | * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU General Public License | |
14 | * as published by the Free Software Foundation; either version | |
15 | * 2 of the License, or (at your option) any later version. | |
16 | */ | |
17 | ||
18 | /* used for print_string */ | |
1da177e4 LT |
19 | #include <linux/tty.h> |
20 | ||
21 | #include <linux/kmod.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/vmalloc.h> | |
24 | #include <linux/netfilter_bridge/ebtables.h> | |
25 | #include <linux/spinlock.h> | |
df0933dc | 26 | #include <linux/mutex.h> |
1da177e4 LT |
27 | #include <asm/uaccess.h> |
28 | #include <linux/smp.h> | |
c8923c6b | 29 | #include <linux/cpumask.h> |
1da177e4 LT |
30 | #include <net/sock.h> |
31 | /* needed for logical [in,out]-dev filtering */ | |
32 | #include "../br_private.h" | |
33 | ||
1da177e4 | 34 | #define BUGPRINT(format, args...) printk("kernel msg: ebtables bug: please "\ |
9d6f229f | 35 | "report to author: "format, ## args) |
1da177e4 | 36 | /* #define BUGPRINT(format, args...) */ |
1da177e4 | 37 | #define MEMPRINT(format, args...) printk("kernel msg: ebtables "\ |
9d6f229f | 38 | ": out of memory: "format, ## args) |
1da177e4 LT |
39 | /* #define MEMPRINT(format, args...) */ |
40 | ||
41 | ||
42 | ||
43 | /* | |
44 | * Each cpu has its own set of counters, so there is no need for write_lock in | |
45 | * the softirq | |
46 | * For reading or updating the counters, the user context needs to | |
47 | * get a write_lock | |
48 | */ | |
49 | ||
50 | /* The size of each set of counters is altered to get cache alignment */ | |
51 | #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1)) | |
52 | #define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter))) | |
53 | #define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \ | |
54 | COUNTER_OFFSET(n) * cpu)) | |
55 | ||
56 | ||
57 | ||
57b47a53 | 58 | static DEFINE_MUTEX(ebt_mutex); |
1da177e4 LT |
59 | static LIST_HEAD(ebt_tables); |
60 | static LIST_HEAD(ebt_targets); | |
61 | static LIST_HEAD(ebt_matches); | |
62 | static LIST_HEAD(ebt_watchers); | |
63 | ||
64 | static struct ebt_target ebt_standard_target = | |
65 | { {NULL, NULL}, EBT_STANDARD_TARGET, NULL, NULL, NULL, NULL}; | |
66 | ||
67 | static inline int ebt_do_watcher (struct ebt_entry_watcher *w, | |
68 | const struct sk_buff *skb, unsigned int hooknr, const struct net_device *in, | |
69 | const struct net_device *out) | |
70 | { | |
71 | w->u.watcher->watcher(skb, hooknr, in, out, w->data, | |
72 | w->watcher_size); | |
73 | /* watchers don't give a verdict */ | |
74 | return 0; | |
75 | } | |
76 | ||
77 | static inline int ebt_do_match (struct ebt_entry_match *m, | |
78 | const struct sk_buff *skb, const struct net_device *in, | |
79 | const struct net_device *out) | |
80 | { | |
81 | return m->u.match->match(skb, in, out, m->data, | |
82 | m->match_size); | |
83 | } | |
84 | ||
85 | static inline int ebt_dev_check(char *entry, const struct net_device *device) | |
86 | { | |
87 | int i = 0; | |
6f5b7ef6 | 88 | const char *devname = device->name; |
1da177e4 LT |
89 | |
90 | if (*entry == '\0') | |
91 | return 0; | |
92 | if (!device) | |
93 | return 1; | |
94 | /* 1 is the wildcard token */ | |
95 | while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i]) | |
96 | i++; | |
97 | return (devname[i] != entry[i] && entry[i] != 1); | |
98 | } | |
99 | ||
100 | #define FWINV2(bool,invflg) ((bool) ^ !!(e->invflags & invflg)) | |
101 | /* process standard matches */ | |
102 | static inline int ebt_basic_match(struct ebt_entry *e, struct ethhdr *h, | |
103 | const struct net_device *in, const struct net_device *out) | |
104 | { | |
105 | int verdict, i; | |
106 | ||
107 | if (e->bitmask & EBT_802_3) { | |
108 | if (FWINV2(ntohs(h->h_proto) >= 1536, EBT_IPROTO)) | |
109 | return 1; | |
110 | } else if (!(e->bitmask & EBT_NOPROTO) && | |
111 | FWINV2(e->ethproto != h->h_proto, EBT_IPROTO)) | |
112 | return 1; | |
113 | ||
114 | if (FWINV2(ebt_dev_check(e->in, in), EBT_IIN)) | |
115 | return 1; | |
116 | if (FWINV2(ebt_dev_check(e->out, out), EBT_IOUT)) | |
117 | return 1; | |
118 | if ((!in || !in->br_port) ? 0 : FWINV2(ebt_dev_check( | |
119 | e->logical_in, in->br_port->br->dev), EBT_ILOGICALIN)) | |
120 | return 1; | |
121 | if ((!out || !out->br_port) ? 0 : FWINV2(ebt_dev_check( | |
122 | e->logical_out, out->br_port->br->dev), EBT_ILOGICALOUT)) | |
123 | return 1; | |
124 | ||
125 | if (e->bitmask & EBT_SOURCEMAC) { | |
126 | verdict = 0; | |
127 | for (i = 0; i < 6; i++) | |
128 | verdict |= (h->h_source[i] ^ e->sourcemac[i]) & | |
129 | e->sourcemsk[i]; | |
130 | if (FWINV2(verdict != 0, EBT_ISOURCE) ) | |
131 | return 1; | |
132 | } | |
133 | if (e->bitmask & EBT_DESTMAC) { | |
134 | verdict = 0; | |
135 | for (i = 0; i < 6; i++) | |
136 | verdict |= (h->h_dest[i] ^ e->destmac[i]) & | |
137 | e->destmsk[i]; | |
138 | if (FWINV2(verdict != 0, EBT_IDEST) ) | |
139 | return 1; | |
140 | } | |
141 | return 0; | |
142 | } | |
143 | ||
144 | /* Do some firewalling */ | |
3db05fea | 145 | unsigned int ebt_do_table (unsigned int hook, struct sk_buff *skb, |
1da177e4 LT |
146 | const struct net_device *in, const struct net_device *out, |
147 | struct ebt_table *table) | |
148 | { | |
149 | int i, nentries; | |
150 | struct ebt_entry *point; | |
151 | struct ebt_counter *counter_base, *cb_base; | |
152 | struct ebt_entry_target *t; | |
153 | int verdict, sp = 0; | |
154 | struct ebt_chainstack *cs; | |
155 | struct ebt_entries *chaininfo; | |
156 | char *base; | |
157 | struct ebt_table_info *private; | |
158 | ||
159 | read_lock_bh(&table->lock); | |
160 | private = table->private; | |
161 | cb_base = COUNTER_BASE(private->counters, private->nentries, | |
162 | smp_processor_id()); | |
163 | if (private->chainstack) | |
164 | cs = private->chainstack[smp_processor_id()]; | |
165 | else | |
166 | cs = NULL; | |
167 | chaininfo = private->hook_entry[hook]; | |
168 | nentries = private->hook_entry[hook]->nentries; | |
169 | point = (struct ebt_entry *)(private->hook_entry[hook]->data); | |
170 | counter_base = cb_base + private->hook_entry[hook]->counter_offset; | |
171 | /* base for chain jumps */ | |
172 | base = private->entries; | |
173 | i = 0; | |
174 | while (i < nentries) { | |
3db05fea | 175 | if (ebt_basic_match(point, eth_hdr(skb), in, out)) |
1da177e4 LT |
176 | goto letscontinue; |
177 | ||
3db05fea | 178 | if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, in, out) != 0) |
1da177e4 LT |
179 | goto letscontinue; |
180 | ||
181 | /* increase counter */ | |
182 | (*(counter_base + i)).pcnt++; | |
3db05fea | 183 | (*(counter_base + i)).bcnt += skb->len; |
1da177e4 LT |
184 | |
185 | /* these should only watch: not modify, nor tell us | |
186 | what to do with the packet */ | |
3db05fea | 187 | EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, hook, in, |
1da177e4 LT |
188 | out); |
189 | ||
190 | t = (struct ebt_entry_target *) | |
191 | (((char *)point) + point->target_offset); | |
192 | /* standard target */ | |
193 | if (!t->u.target->target) | |
194 | verdict = ((struct ebt_standard_target *)t)->verdict; | |
195 | else | |
3db05fea | 196 | verdict = t->u.target->target(skb, hook, |
1da177e4 LT |
197 | in, out, t->data, t->target_size); |
198 | if (verdict == EBT_ACCEPT) { | |
199 | read_unlock_bh(&table->lock); | |
200 | return NF_ACCEPT; | |
201 | } | |
202 | if (verdict == EBT_DROP) { | |
203 | read_unlock_bh(&table->lock); | |
204 | return NF_DROP; | |
205 | } | |
206 | if (verdict == EBT_RETURN) { | |
207 | letsreturn: | |
208 | #ifdef CONFIG_NETFILTER_DEBUG | |
209 | if (sp == 0) { | |
210 | BUGPRINT("RETURN on base chain"); | |
211 | /* act like this is EBT_CONTINUE */ | |
212 | goto letscontinue; | |
213 | } | |
214 | #endif | |
215 | sp--; | |
216 | /* put all the local variables right */ | |
217 | i = cs[sp].n; | |
218 | chaininfo = cs[sp].chaininfo; | |
219 | nentries = chaininfo->nentries; | |
220 | point = cs[sp].e; | |
221 | counter_base = cb_base + | |
222 | chaininfo->counter_offset; | |
223 | continue; | |
224 | } | |
225 | if (verdict == EBT_CONTINUE) | |
226 | goto letscontinue; | |
227 | #ifdef CONFIG_NETFILTER_DEBUG | |
228 | if (verdict < 0) { | |
229 | BUGPRINT("bogus standard verdict\n"); | |
230 | read_unlock_bh(&table->lock); | |
231 | return NF_DROP; | |
232 | } | |
233 | #endif | |
234 | /* jump to a udc */ | |
235 | cs[sp].n = i + 1; | |
236 | cs[sp].chaininfo = chaininfo; | |
237 | cs[sp].e = (struct ebt_entry *) | |
238 | (((char *)point) + point->next_offset); | |
239 | i = 0; | |
240 | chaininfo = (struct ebt_entries *) (base + verdict); | |
241 | #ifdef CONFIG_NETFILTER_DEBUG | |
242 | if (chaininfo->distinguisher) { | |
243 | BUGPRINT("jump to non-chain\n"); | |
244 | read_unlock_bh(&table->lock); | |
245 | return NF_DROP; | |
246 | } | |
247 | #endif | |
248 | nentries = chaininfo->nentries; | |
249 | point = (struct ebt_entry *)chaininfo->data; | |
250 | counter_base = cb_base + chaininfo->counter_offset; | |
251 | sp++; | |
252 | continue; | |
253 | letscontinue: | |
254 | point = (struct ebt_entry *) | |
255 | (((char *)point) + point->next_offset); | |
256 | i++; | |
257 | } | |
258 | ||
259 | /* I actually like this :) */ | |
260 | if (chaininfo->policy == EBT_RETURN) | |
261 | goto letsreturn; | |
262 | if (chaininfo->policy == EBT_ACCEPT) { | |
263 | read_unlock_bh(&table->lock); | |
264 | return NF_ACCEPT; | |
265 | } | |
266 | read_unlock_bh(&table->lock); | |
267 | return NF_DROP; | |
268 | } | |
269 | ||
270 | /* If it succeeds, returns element and locks mutex */ | |
271 | static inline void * | |
272 | find_inlist_lock_noload(struct list_head *head, const char *name, int *error, | |
57b47a53 | 273 | struct mutex *mutex) |
1da177e4 | 274 | { |
df0933dc PM |
275 | struct { |
276 | struct list_head list; | |
277 | char name[EBT_FUNCTION_MAXNAMELEN]; | |
278 | } *e; | |
1da177e4 | 279 | |
57b47a53 | 280 | *error = mutex_lock_interruptible(mutex); |
1da177e4 LT |
281 | if (*error != 0) |
282 | return NULL; | |
283 | ||
df0933dc PM |
284 | list_for_each_entry(e, head, list) { |
285 | if (strcmp(e->name, name) == 0) | |
286 | return e; | |
1da177e4 | 287 | } |
df0933dc PM |
288 | *error = -ENOENT; |
289 | mutex_unlock(mutex); | |
290 | return NULL; | |
1da177e4 LT |
291 | } |
292 | ||
293 | #ifndef CONFIG_KMOD | |
294 | #define find_inlist_lock(h,n,p,e,m) find_inlist_lock_noload((h),(n),(e),(m)) | |
295 | #else | |
296 | static void * | |
297 | find_inlist_lock(struct list_head *head, const char *name, const char *prefix, | |
57b47a53 | 298 | int *error, struct mutex *mutex) |
1da177e4 LT |
299 | { |
300 | void *ret; | |
301 | ||
302 | ret = find_inlist_lock_noload(head, name, error, mutex); | |
303 | if (!ret) { | |
304 | request_module("%s%s", prefix, name); | |
305 | ret = find_inlist_lock_noload(head, name, error, mutex); | |
306 | } | |
307 | return ret; | |
308 | } | |
309 | #endif | |
310 | ||
311 | static inline struct ebt_table * | |
57b47a53 | 312 | find_table_lock(const char *name, int *error, struct mutex *mutex) |
1da177e4 LT |
313 | { |
314 | return find_inlist_lock(&ebt_tables, name, "ebtable_", error, mutex); | |
315 | } | |
316 | ||
317 | static inline struct ebt_match * | |
57b47a53 | 318 | find_match_lock(const char *name, int *error, struct mutex *mutex) |
1da177e4 LT |
319 | { |
320 | return find_inlist_lock(&ebt_matches, name, "ebt_", error, mutex); | |
321 | } | |
322 | ||
323 | static inline struct ebt_watcher * | |
57b47a53 | 324 | find_watcher_lock(const char *name, int *error, struct mutex *mutex) |
1da177e4 LT |
325 | { |
326 | return find_inlist_lock(&ebt_watchers, name, "ebt_", error, mutex); | |
327 | } | |
328 | ||
329 | static inline struct ebt_target * | |
57b47a53 | 330 | find_target_lock(const char *name, int *error, struct mutex *mutex) |
1da177e4 LT |
331 | { |
332 | return find_inlist_lock(&ebt_targets, name, "ebt_", error, mutex); | |
333 | } | |
334 | ||
335 | static inline int | |
336 | ebt_check_match(struct ebt_entry_match *m, struct ebt_entry *e, | |
337 | const char *name, unsigned int hookmask, unsigned int *cnt) | |
338 | { | |
339 | struct ebt_match *match; | |
14197d54 | 340 | size_t left = ((char *)e + e->watchers_offset) - (char *)m; |
1da177e4 LT |
341 | int ret; |
342 | ||
14197d54 AV |
343 | if (left < sizeof(struct ebt_entry_match) || |
344 | left - sizeof(struct ebt_entry_match) < m->match_size) | |
1da177e4 LT |
345 | return -EINVAL; |
346 | match = find_match_lock(m->u.name, &ret, &ebt_mutex); | |
347 | if (!match) | |
348 | return ret; | |
349 | m->u.match = match; | |
350 | if (!try_module_get(match->me)) { | |
57b47a53 | 351 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
352 | return -ENOENT; |
353 | } | |
57b47a53 | 354 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
355 | if (match->check && |
356 | match->check(name, hookmask, e, m->data, m->match_size) != 0) { | |
357 | BUGPRINT("match->check failed\n"); | |
358 | module_put(match->me); | |
359 | return -EINVAL; | |
360 | } | |
361 | (*cnt)++; | |
362 | return 0; | |
363 | } | |
364 | ||
365 | static inline int | |
366 | ebt_check_watcher(struct ebt_entry_watcher *w, struct ebt_entry *e, | |
367 | const char *name, unsigned int hookmask, unsigned int *cnt) | |
368 | { | |
369 | struct ebt_watcher *watcher; | |
14197d54 | 370 | size_t left = ((char *)e + e->target_offset) - (char *)w; |
1da177e4 LT |
371 | int ret; |
372 | ||
14197d54 AV |
373 | if (left < sizeof(struct ebt_entry_watcher) || |
374 | left - sizeof(struct ebt_entry_watcher) < w->watcher_size) | |
1da177e4 LT |
375 | return -EINVAL; |
376 | watcher = find_watcher_lock(w->u.name, &ret, &ebt_mutex); | |
377 | if (!watcher) | |
378 | return ret; | |
379 | w->u.watcher = watcher; | |
380 | if (!try_module_get(watcher->me)) { | |
57b47a53 | 381 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
382 | return -ENOENT; |
383 | } | |
57b47a53 | 384 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
385 | if (watcher->check && |
386 | watcher->check(name, hookmask, e, w->data, w->watcher_size) != 0) { | |
387 | BUGPRINT("watcher->check failed\n"); | |
388 | module_put(watcher->me); | |
389 | return -EINVAL; | |
390 | } | |
391 | (*cnt)++; | |
392 | return 0; | |
393 | } | |
394 | ||
70fe9af4 AV |
395 | static int ebt_verify_pointers(struct ebt_replace *repl, |
396 | struct ebt_table_info *newinfo) | |
1da177e4 | 397 | { |
70fe9af4 AV |
398 | unsigned int limit = repl->entries_size; |
399 | unsigned int valid_hooks = repl->valid_hooks; | |
400 | unsigned int offset = 0; | |
1da177e4 LT |
401 | int i; |
402 | ||
e4fd77de AV |
403 | for (i = 0; i < NF_BR_NUMHOOKS; i++) |
404 | newinfo->hook_entry[i] = NULL; | |
405 | ||
406 | newinfo->entries_size = repl->entries_size; | |
407 | newinfo->nentries = repl->nentries; | |
408 | ||
70fe9af4 AV |
409 | while (offset < limit) { |
410 | size_t left = limit - offset; | |
411 | struct ebt_entry *e = (void *)newinfo->entries + offset; | |
bb2ef25c | 412 | |
70fe9af4 | 413 | if (left < sizeof(unsigned int)) |
1da177e4 | 414 | break; |
70fe9af4 AV |
415 | |
416 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
417 | if ((valid_hooks & (1 << i)) == 0) | |
418 | continue; | |
1e419cd9 AV |
419 | if ((char __user *)repl->hook_entry[i] == |
420 | repl->entries + offset) | |
70fe9af4 AV |
421 | break; |
422 | } | |
423 | ||
424 | if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) { | |
425 | if (e->bitmask != 0) { | |
426 | /* we make userspace set this right, | |
427 | so there is no misunderstanding */ | |
428 | BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set " | |
429 | "in distinguisher\n"); | |
430 | return -EINVAL; | |
431 | } | |
432 | if (i != NF_BR_NUMHOOKS) | |
433 | newinfo->hook_entry[i] = (struct ebt_entries *)e; | |
434 | if (left < sizeof(struct ebt_entries)) | |
435 | break; | |
436 | offset += sizeof(struct ebt_entries); | |
437 | } else { | |
438 | if (left < sizeof(struct ebt_entry)) | |
439 | break; | |
440 | if (left < e->next_offset) | |
441 | break; | |
442 | offset += e->next_offset; | |
1da177e4 | 443 | } |
22b440bf | 444 | } |
70fe9af4 AV |
445 | if (offset != limit) { |
446 | BUGPRINT("entries_size too small\n"); | |
447 | return -EINVAL; | |
448 | } | |
e4fd77de AV |
449 | |
450 | /* check if all valid hooks have a chain */ | |
451 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
452 | if (!newinfo->hook_entry[i] && | |
453 | (valid_hooks & (1 << i))) { | |
454 | BUGPRINT("Valid hook without chain\n"); | |
455 | return -EINVAL; | |
456 | } | |
457 | } | |
22b440bf | 458 | return 0; |
22b440bf AV |
459 | } |
460 | ||
461 | /* | |
462 | * this one is very careful, as it is the first function | |
463 | * to parse the userspace data | |
464 | */ | |
465 | static inline int | |
466 | ebt_check_entry_size_and_hooks(struct ebt_entry *e, | |
0e795531 AV |
467 | struct ebt_table_info *newinfo, |
468 | unsigned int *n, unsigned int *cnt, | |
469 | unsigned int *totalcnt, unsigned int *udc_cnt) | |
22b440bf | 470 | { |
22b440bf AV |
471 | int i; |
472 | ||
473 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
0e795531 | 474 | if ((void *)e == (void *)newinfo->hook_entry[i]) |
22b440bf AV |
475 | break; |
476 | } | |
477 | /* beginning of a new chain | |
478 | if i == NF_BR_NUMHOOKS it must be a user defined chain */ | |
479 | if (i != NF_BR_NUMHOOKS || !e->bitmask) { | |
1da177e4 LT |
480 | /* this checks if the previous chain has as many entries |
481 | as it said it has */ | |
482 | if (*n != *cnt) { | |
483 | BUGPRINT("nentries does not equal the nr of entries " | |
9d6f229f | 484 | "in the chain\n"); |
1da177e4 LT |
485 | return -EINVAL; |
486 | } | |
1da177e4 LT |
487 | if (((struct ebt_entries *)e)->policy != EBT_DROP && |
488 | ((struct ebt_entries *)e)->policy != EBT_ACCEPT) { | |
489 | /* only RETURN from udc */ | |
490 | if (i != NF_BR_NUMHOOKS || | |
491 | ((struct ebt_entries *)e)->policy != EBT_RETURN) { | |
492 | BUGPRINT("bad policy\n"); | |
493 | return -EINVAL; | |
494 | } | |
495 | } | |
496 | if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */ | |
497 | (*udc_cnt)++; | |
1da177e4 LT |
498 | if (((struct ebt_entries *)e)->counter_offset != *totalcnt) { |
499 | BUGPRINT("counter_offset != totalcnt"); | |
500 | return -EINVAL; | |
501 | } | |
502 | *n = ((struct ebt_entries *)e)->nentries; | |
503 | *cnt = 0; | |
504 | return 0; | |
505 | } | |
506 | /* a plain old entry, heh */ | |
507 | if (sizeof(struct ebt_entry) > e->watchers_offset || | |
508 | e->watchers_offset > e->target_offset || | |
509 | e->target_offset >= e->next_offset) { | |
510 | BUGPRINT("entry offsets not in right order\n"); | |
511 | return -EINVAL; | |
512 | } | |
513 | /* this is not checked anywhere else */ | |
514 | if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target)) { | |
515 | BUGPRINT("target size too small\n"); | |
516 | return -EINVAL; | |
517 | } | |
1da177e4 LT |
518 | (*cnt)++; |
519 | (*totalcnt)++; | |
520 | return 0; | |
521 | } | |
522 | ||
523 | struct ebt_cl_stack | |
524 | { | |
525 | struct ebt_chainstack cs; | |
526 | int from; | |
527 | unsigned int hookmask; | |
528 | }; | |
529 | ||
530 | /* | |
531 | * we need these positions to check that the jumps to a different part of the | |
532 | * entries is a jump to the beginning of a new chain. | |
533 | */ | |
534 | static inline int | |
535 | ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo, | |
177abc34 | 536 | unsigned int *n, struct ebt_cl_stack *udc) |
1da177e4 LT |
537 | { |
538 | int i; | |
539 | ||
540 | /* we're only interested in chain starts */ | |
40642f95 | 541 | if (e->bitmask) |
1da177e4 LT |
542 | return 0; |
543 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
1da177e4 LT |
544 | if (newinfo->hook_entry[i] == (struct ebt_entries *)e) |
545 | break; | |
546 | } | |
547 | /* only care about udc */ | |
548 | if (i != NF_BR_NUMHOOKS) | |
549 | return 0; | |
550 | ||
551 | udc[*n].cs.chaininfo = (struct ebt_entries *)e; | |
552 | /* these initialisations are depended on later in check_chainloops() */ | |
553 | udc[*n].cs.n = 0; | |
554 | udc[*n].hookmask = 0; | |
555 | ||
556 | (*n)++; | |
557 | return 0; | |
558 | } | |
559 | ||
560 | static inline int | |
561 | ebt_cleanup_match(struct ebt_entry_match *m, unsigned int *i) | |
562 | { | |
563 | if (i && (*i)-- == 0) | |
564 | return 1; | |
565 | if (m->u.match->destroy) | |
566 | m->u.match->destroy(m->data, m->match_size); | |
567 | module_put(m->u.match->me); | |
568 | ||
569 | return 0; | |
570 | } | |
571 | ||
572 | static inline int | |
573 | ebt_cleanup_watcher(struct ebt_entry_watcher *w, unsigned int *i) | |
574 | { | |
575 | if (i && (*i)-- == 0) | |
576 | return 1; | |
577 | if (w->u.watcher->destroy) | |
578 | w->u.watcher->destroy(w->data, w->watcher_size); | |
579 | module_put(w->u.watcher->me); | |
580 | ||
581 | return 0; | |
582 | } | |
583 | ||
584 | static inline int | |
585 | ebt_cleanup_entry(struct ebt_entry *e, unsigned int *cnt) | |
586 | { | |
587 | struct ebt_entry_target *t; | |
588 | ||
40642f95 | 589 | if (e->bitmask == 0) |
1da177e4 LT |
590 | return 0; |
591 | /* we're done */ | |
592 | if (cnt && (*cnt)-- == 0) | |
593 | return 1; | |
594 | EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, NULL); | |
595 | EBT_MATCH_ITERATE(e, ebt_cleanup_match, NULL); | |
596 | t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); | |
597 | if (t->u.target->destroy) | |
598 | t->u.target->destroy(t->data, t->target_size); | |
599 | module_put(t->u.target->me); | |
600 | ||
601 | return 0; | |
602 | } | |
603 | ||
604 | static inline int | |
605 | ebt_check_entry(struct ebt_entry *e, struct ebt_table_info *newinfo, | |
f7da79d9 | 606 | const char *name, unsigned int *cnt, |
1da177e4 LT |
607 | struct ebt_cl_stack *cl_s, unsigned int udc_cnt) |
608 | { | |
609 | struct ebt_entry_target *t; | |
610 | struct ebt_target *target; | |
611 | unsigned int i, j, hook = 0, hookmask = 0; | |
44f9a2fd | 612 | size_t gap; |
1da177e4 LT |
613 | int ret; |
614 | ||
615 | /* don't mess with the struct ebt_entries */ | |
40642f95 | 616 | if (e->bitmask == 0) |
1da177e4 LT |
617 | return 0; |
618 | ||
619 | if (e->bitmask & ~EBT_F_MASK) { | |
620 | BUGPRINT("Unknown flag for bitmask\n"); | |
621 | return -EINVAL; | |
622 | } | |
623 | if (e->invflags & ~EBT_INV_MASK) { | |
624 | BUGPRINT("Unknown flag for inv bitmask\n"); | |
625 | return -EINVAL; | |
626 | } | |
627 | if ( (e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3) ) { | |
628 | BUGPRINT("NOPROTO & 802_3 not allowed\n"); | |
629 | return -EINVAL; | |
630 | } | |
631 | /* what hook do we belong to? */ | |
632 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
f7da79d9 | 633 | if (!newinfo->hook_entry[i]) |
1da177e4 LT |
634 | continue; |
635 | if ((char *)newinfo->hook_entry[i] < (char *)e) | |
636 | hook = i; | |
637 | else | |
638 | break; | |
639 | } | |
640 | /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on | |
641 | a base chain */ | |
642 | if (i < NF_BR_NUMHOOKS) | |
643 | hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS); | |
644 | else { | |
645 | for (i = 0; i < udc_cnt; i++) | |
646 | if ((char *)(cl_s[i].cs.chaininfo) > (char *)e) | |
647 | break; | |
648 | if (i == 0) | |
649 | hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS); | |
650 | else | |
651 | hookmask = cl_s[i - 1].hookmask; | |
652 | } | |
653 | i = 0; | |
654 | ret = EBT_MATCH_ITERATE(e, ebt_check_match, e, name, hookmask, &i); | |
655 | if (ret != 0) | |
656 | goto cleanup_matches; | |
657 | j = 0; | |
658 | ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, e, name, hookmask, &j); | |
659 | if (ret != 0) | |
660 | goto cleanup_watchers; | |
661 | t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); | |
44f9a2fd | 662 | gap = e->next_offset - e->target_offset; |
1da177e4 LT |
663 | target = find_target_lock(t->u.name, &ret, &ebt_mutex); |
664 | if (!target) | |
665 | goto cleanup_watchers; | |
666 | if (!try_module_get(target->me)) { | |
57b47a53 | 667 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
668 | ret = -ENOENT; |
669 | goto cleanup_watchers; | |
670 | } | |
57b47a53 | 671 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
672 | |
673 | t->u.target = target; | |
674 | if (t->u.target == &ebt_standard_target) { | |
14197d54 | 675 | if (gap < sizeof(struct ebt_standard_target)) { |
1da177e4 LT |
676 | BUGPRINT("Standard target size too big\n"); |
677 | ret = -EFAULT; | |
678 | goto cleanup_watchers; | |
679 | } | |
680 | if (((struct ebt_standard_target *)t)->verdict < | |
681 | -NUM_STANDARD_TARGETS) { | |
682 | BUGPRINT("Invalid standard target\n"); | |
683 | ret = -EFAULT; | |
684 | goto cleanup_watchers; | |
685 | } | |
14197d54 | 686 | } else if (t->target_size > gap - sizeof(struct ebt_entry_target) || |
1da177e4 LT |
687 | (t->u.target->check && |
688 | t->u.target->check(name, hookmask, e, t->data, t->target_size) != 0)){ | |
689 | module_put(t->u.target->me); | |
690 | ret = -EFAULT; | |
691 | goto cleanup_watchers; | |
692 | } | |
693 | (*cnt)++; | |
694 | return 0; | |
695 | cleanup_watchers: | |
696 | EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, &j); | |
697 | cleanup_matches: | |
698 | EBT_MATCH_ITERATE(e, ebt_cleanup_match, &i); | |
699 | return ret; | |
700 | } | |
701 | ||
702 | /* | |
703 | * checks for loops and sets the hook mask for udc | |
704 | * the hook mask for udc tells us from which base chains the udc can be | |
705 | * accessed. This mask is a parameter to the check() functions of the extensions | |
706 | */ | |
707 | static int check_chainloops(struct ebt_entries *chain, struct ebt_cl_stack *cl_s, | |
708 | unsigned int udc_cnt, unsigned int hooknr, char *base) | |
709 | { | |
710 | int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict; | |
711 | struct ebt_entry *e = (struct ebt_entry *)chain->data; | |
712 | struct ebt_entry_target *t; | |
713 | ||
714 | while (pos < nentries || chain_nr != -1) { | |
715 | /* end of udc, go back one 'recursion' step */ | |
716 | if (pos == nentries) { | |
717 | /* put back values of the time when this chain was called */ | |
718 | e = cl_s[chain_nr].cs.e; | |
719 | if (cl_s[chain_nr].from != -1) | |
720 | nentries = | |
721 | cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries; | |
722 | else | |
723 | nentries = chain->nentries; | |
724 | pos = cl_s[chain_nr].cs.n; | |
725 | /* make sure we won't see a loop that isn't one */ | |
726 | cl_s[chain_nr].cs.n = 0; | |
727 | chain_nr = cl_s[chain_nr].from; | |
728 | if (pos == nentries) | |
729 | continue; | |
730 | } | |
731 | t = (struct ebt_entry_target *) | |
732 | (((char *)e) + e->target_offset); | |
733 | if (strcmp(t->u.name, EBT_STANDARD_TARGET)) | |
734 | goto letscontinue; | |
735 | if (e->target_offset + sizeof(struct ebt_standard_target) > | |
736 | e->next_offset) { | |
737 | BUGPRINT("Standard target size too big\n"); | |
738 | return -1; | |
739 | } | |
740 | verdict = ((struct ebt_standard_target *)t)->verdict; | |
741 | if (verdict >= 0) { /* jump to another chain */ | |
742 | struct ebt_entries *hlp2 = | |
743 | (struct ebt_entries *)(base + verdict); | |
744 | for (i = 0; i < udc_cnt; i++) | |
745 | if (hlp2 == cl_s[i].cs.chaininfo) | |
746 | break; | |
747 | /* bad destination or loop */ | |
748 | if (i == udc_cnt) { | |
749 | BUGPRINT("bad destination\n"); | |
750 | return -1; | |
751 | } | |
752 | if (cl_s[i].cs.n) { | |
753 | BUGPRINT("loop\n"); | |
754 | return -1; | |
755 | } | |
98a0824a AV |
756 | if (cl_s[i].hookmask & (1 << hooknr)) |
757 | goto letscontinue; | |
758 | /* this can't be 0, so the loop test is correct */ | |
1da177e4 LT |
759 | cl_s[i].cs.n = pos + 1; |
760 | pos = 0; | |
761 | cl_s[i].cs.e = ((void *)e + e->next_offset); | |
762 | e = (struct ebt_entry *)(hlp2->data); | |
763 | nentries = hlp2->nentries; | |
764 | cl_s[i].from = chain_nr; | |
765 | chain_nr = i; | |
766 | /* this udc is accessible from the base chain for hooknr */ | |
767 | cl_s[i].hookmask |= (1 << hooknr); | |
768 | continue; | |
769 | } | |
770 | letscontinue: | |
771 | e = (void *)e + e->next_offset; | |
772 | pos++; | |
773 | } | |
774 | return 0; | |
775 | } | |
776 | ||
777 | /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */ | |
1bc2326c | 778 | static int translate_table(char *name, struct ebt_table_info *newinfo) |
1da177e4 LT |
779 | { |
780 | unsigned int i, j, k, udc_cnt; | |
781 | int ret; | |
782 | struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */ | |
783 | ||
784 | i = 0; | |
1f072c96 | 785 | while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i]) |
1da177e4 LT |
786 | i++; |
787 | if (i == NF_BR_NUMHOOKS) { | |
788 | BUGPRINT("No valid hooks specified\n"); | |
789 | return -EINVAL; | |
790 | } | |
1f072c96 | 791 | if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) { |
1da177e4 LT |
792 | BUGPRINT("Chains don't start at beginning\n"); |
793 | return -EINVAL; | |
794 | } | |
795 | /* make sure chains are ordered after each other in same order | |
796 | as their corresponding hooks */ | |
797 | for (j = i + 1; j < NF_BR_NUMHOOKS; j++) { | |
1f072c96 | 798 | if (!newinfo->hook_entry[j]) |
1da177e4 | 799 | continue; |
1f072c96 | 800 | if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) { |
1da177e4 LT |
801 | BUGPRINT("Hook order must be followed\n"); |
802 | return -EINVAL; | |
803 | } | |
804 | i = j; | |
805 | } | |
806 | ||
1da177e4 LT |
807 | /* do some early checkings and initialize some things */ |
808 | i = 0; /* holds the expected nr. of entries for the chain */ | |
809 | j = 0; /* holds the up to now counted entries for the chain */ | |
810 | k = 0; /* holds the total nr. of entries, should equal | |
9d6f229f | 811 | newinfo->nentries afterwards */ |
1da177e4 LT |
812 | udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */ |
813 | ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
0e795531 AV |
814 | ebt_check_entry_size_and_hooks, newinfo, |
815 | &i, &j, &k, &udc_cnt); | |
1da177e4 LT |
816 | |
817 | if (ret != 0) | |
818 | return ret; | |
819 | ||
820 | if (i != j) { | |
821 | BUGPRINT("nentries does not equal the nr of entries in the " | |
9d6f229f | 822 | "(last) chain\n"); |
1da177e4 LT |
823 | return -EINVAL; |
824 | } | |
825 | if (k != newinfo->nentries) { | |
826 | BUGPRINT("Total nentries is wrong\n"); | |
827 | return -EINVAL; | |
828 | } | |
829 | ||
1da177e4 LT |
830 | /* get the location of the udc, put them in an array |
831 | while we're at it, allocate the chainstack */ | |
832 | if (udc_cnt) { | |
833 | /* this will get free'd in do_replace()/ebt_register_table() | |
834 | if an error occurs */ | |
7ad4d2f6 | 835 | newinfo->chainstack = |
53b8a315 | 836 | vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack))); |
1da177e4 LT |
837 | if (!newinfo->chainstack) |
838 | return -ENOMEM; | |
6f912042 | 839 | for_each_possible_cpu(i) { |
1da177e4 | 840 | newinfo->chainstack[i] = |
18bc89aa | 841 | vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0]))); |
1da177e4 LT |
842 | if (!newinfo->chainstack[i]) { |
843 | while (i) | |
844 | vfree(newinfo->chainstack[--i]); | |
845 | vfree(newinfo->chainstack); | |
846 | newinfo->chainstack = NULL; | |
847 | return -ENOMEM; | |
848 | } | |
849 | } | |
850 | ||
18bc89aa | 851 | cl_s = vmalloc(udc_cnt * sizeof(*cl_s)); |
1da177e4 LT |
852 | if (!cl_s) |
853 | return -ENOMEM; | |
854 | i = 0; /* the i'th udc */ | |
855 | EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
177abc34 | 856 | ebt_get_udc_positions, newinfo, &i, cl_s); |
1da177e4 LT |
857 | /* sanity check */ |
858 | if (i != udc_cnt) { | |
859 | BUGPRINT("i != udc_cnt\n"); | |
860 | vfree(cl_s); | |
861 | return -EFAULT; | |
862 | } | |
863 | } | |
864 | ||
865 | /* Check for loops */ | |
866 | for (i = 0; i < NF_BR_NUMHOOKS; i++) | |
1f072c96 | 867 | if (newinfo->hook_entry[i]) |
1da177e4 LT |
868 | if (check_chainloops(newinfo->hook_entry[i], |
869 | cl_s, udc_cnt, i, newinfo->entries)) { | |
68d31872 | 870 | vfree(cl_s); |
1da177e4 LT |
871 | return -EINVAL; |
872 | } | |
873 | ||
96de0e25 | 874 | /* we now know the following (along with E=mc²): |
1da177e4 LT |
875 | - the nr of entries in each chain is right |
876 | - the size of the allocated space is right | |
877 | - all valid hooks have a corresponding chain | |
878 | - there are no loops | |
879 | - wrong data can still be on the level of a single entry | |
880 | - could be there are jumps to places that are not the | |
881 | beginning of a chain. This can only occur in chains that | |
882 | are not accessible from any base chains, so we don't care. */ | |
883 | ||
884 | /* used to know what we need to clean up if something goes wrong */ | |
885 | i = 0; | |
886 | ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
1bc2326c | 887 | ebt_check_entry, newinfo, name, &i, cl_s, udc_cnt); |
1da177e4 LT |
888 | if (ret != 0) { |
889 | EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
890 | ebt_cleanup_entry, &i); | |
891 | } | |
68d31872 | 892 | vfree(cl_s); |
1da177e4 LT |
893 | return ret; |
894 | } | |
895 | ||
896 | /* called under write_lock */ | |
897 | static void get_counters(struct ebt_counter *oldcounters, | |
898 | struct ebt_counter *counters, unsigned int nentries) | |
899 | { | |
900 | int i, cpu; | |
901 | struct ebt_counter *counter_base; | |
902 | ||
903 | /* counters of cpu 0 */ | |
904 | memcpy(counters, oldcounters, | |
c8923c6b DM |
905 | sizeof(struct ebt_counter) * nentries); |
906 | ||
1da177e4 | 907 | /* add other counters to those of cpu 0 */ |
6f912042 | 908 | for_each_possible_cpu(cpu) { |
c8923c6b DM |
909 | if (cpu == 0) |
910 | continue; | |
1da177e4 LT |
911 | counter_base = COUNTER_BASE(oldcounters, nentries, cpu); |
912 | for (i = 0; i < nentries; i++) { | |
913 | counters[i].pcnt += counter_base[i].pcnt; | |
914 | counters[i].bcnt += counter_base[i].bcnt; | |
915 | } | |
916 | } | |
917 | } | |
918 | ||
919 | /* replace the table */ | |
920 | static int do_replace(void __user *user, unsigned int len) | |
921 | { | |
922 | int ret, i, countersize; | |
923 | struct ebt_table_info *newinfo; | |
924 | struct ebt_replace tmp; | |
925 | struct ebt_table *t; | |
926 | struct ebt_counter *counterstmp = NULL; | |
927 | /* used to be able to unlock earlier */ | |
928 | struct ebt_table_info *table; | |
929 | ||
930 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) | |
931 | return -EFAULT; | |
932 | ||
933 | if (len != sizeof(tmp) + tmp.entries_size) { | |
934 | BUGPRINT("Wrong len argument\n"); | |
935 | return -EINVAL; | |
936 | } | |
937 | ||
938 | if (tmp.entries_size == 0) { | |
939 | BUGPRINT("Entries_size never zero\n"); | |
940 | return -EINVAL; | |
941 | } | |
ee4bb818 KK |
942 | /* overflow check */ |
943 | if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) / NR_CPUS - | |
944 | SMP_CACHE_BYTES) / sizeof(struct ebt_counter)) | |
945 | return -ENOMEM; | |
946 | if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) | |
947 | return -ENOMEM; | |
948 | ||
53b8a315 | 949 | countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids; |
18bc89aa | 950 | newinfo = vmalloc(sizeof(*newinfo) + countersize); |
1da177e4 LT |
951 | if (!newinfo) |
952 | return -ENOMEM; | |
953 | ||
954 | if (countersize) | |
955 | memset(newinfo->counters, 0, countersize); | |
956 | ||
8b3a7005 | 957 | newinfo->entries = vmalloc(tmp.entries_size); |
1da177e4 LT |
958 | if (!newinfo->entries) { |
959 | ret = -ENOMEM; | |
960 | goto free_newinfo; | |
961 | } | |
962 | if (copy_from_user( | |
963 | newinfo->entries, tmp.entries, tmp.entries_size) != 0) { | |
964 | BUGPRINT("Couldn't copy entries from userspace\n"); | |
965 | ret = -EFAULT; | |
966 | goto free_entries; | |
967 | } | |
968 | ||
969 | /* the user wants counters back | |
970 | the check on the size is done later, when we have the lock */ | |
971 | if (tmp.num_counters) { | |
18bc89aa | 972 | counterstmp = vmalloc(tmp.num_counters * sizeof(*counterstmp)); |
1da177e4 LT |
973 | if (!counterstmp) { |
974 | ret = -ENOMEM; | |
975 | goto free_entries; | |
976 | } | |
977 | } | |
978 | else | |
979 | counterstmp = NULL; | |
980 | ||
981 | /* this can get initialized by translate_table() */ | |
982 | newinfo->chainstack = NULL; | |
1bc2326c AV |
983 | ret = ebt_verify_pointers(&tmp, newinfo); |
984 | if (ret != 0) | |
985 | goto free_counterstmp; | |
986 | ||
987 | ret = translate_table(tmp.name, newinfo); | |
1da177e4 LT |
988 | |
989 | if (ret != 0) | |
990 | goto free_counterstmp; | |
991 | ||
992 | t = find_table_lock(tmp.name, &ret, &ebt_mutex); | |
993 | if (!t) { | |
994 | ret = -ENOENT; | |
995 | goto free_iterate; | |
996 | } | |
997 | ||
998 | /* the table doesn't like it */ | |
999 | if (t->check && (ret = t->check(newinfo, tmp.valid_hooks))) | |
1000 | goto free_unlock; | |
1001 | ||
1002 | if (tmp.num_counters && tmp.num_counters != t->private->nentries) { | |
1003 | BUGPRINT("Wrong nr. of counters requested\n"); | |
1004 | ret = -EINVAL; | |
1005 | goto free_unlock; | |
1006 | } | |
1007 | ||
1008 | /* we have the mutex lock, so no danger in reading this pointer */ | |
1009 | table = t->private; | |
1010 | /* make sure the table can only be rmmod'ed if it contains no rules */ | |
1011 | if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) { | |
1012 | ret = -ENOENT; | |
1013 | goto free_unlock; | |
1014 | } else if (table->nentries && !newinfo->nentries) | |
1015 | module_put(t->me); | |
1016 | /* we need an atomic snapshot of the counters */ | |
1017 | write_lock_bh(&t->lock); | |
1018 | if (tmp.num_counters) | |
1019 | get_counters(t->private->counters, counterstmp, | |
1020 | t->private->nentries); | |
1021 | ||
1022 | t->private = newinfo; | |
1023 | write_unlock_bh(&t->lock); | |
57b47a53 | 1024 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1025 | /* so, a user can change the chains while having messed up her counter |
1026 | allocation. Only reason why this is done is because this way the lock | |
1027 | is held only once, while this doesn't bring the kernel into a | |
1028 | dangerous state. */ | |
1029 | if (tmp.num_counters && | |
1030 | copy_to_user(tmp.counters, counterstmp, | |
1031 | tmp.num_counters * sizeof(struct ebt_counter))) { | |
1032 | BUGPRINT("Couldn't copy counters to userspace\n"); | |
1033 | ret = -EFAULT; | |
1034 | } | |
1035 | else | |
1036 | ret = 0; | |
1037 | ||
1038 | /* decrease module count and free resources */ | |
1039 | EBT_ENTRY_ITERATE(table->entries, table->entries_size, | |
1040 | ebt_cleanup_entry, NULL); | |
1041 | ||
1042 | vfree(table->entries); | |
1043 | if (table->chainstack) { | |
6f912042 | 1044 | for_each_possible_cpu(i) |
1da177e4 LT |
1045 | vfree(table->chainstack[i]); |
1046 | vfree(table->chainstack); | |
1047 | } | |
1048 | vfree(table); | |
1049 | ||
68d31872 | 1050 | vfree(counterstmp); |
1da177e4 LT |
1051 | return ret; |
1052 | ||
1053 | free_unlock: | |
57b47a53 | 1054 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1055 | free_iterate: |
1056 | EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
1057 | ebt_cleanup_entry, NULL); | |
1058 | free_counterstmp: | |
68d31872 | 1059 | vfree(counterstmp); |
1da177e4 LT |
1060 | /* can be initialized in translate_table() */ |
1061 | if (newinfo->chainstack) { | |
6f912042 | 1062 | for_each_possible_cpu(i) |
1da177e4 LT |
1063 | vfree(newinfo->chainstack[i]); |
1064 | vfree(newinfo->chainstack); | |
1065 | } | |
1066 | free_entries: | |
68d31872 | 1067 | vfree(newinfo->entries); |
1da177e4 | 1068 | free_newinfo: |
68d31872 | 1069 | vfree(newinfo); |
1da177e4 LT |
1070 | return ret; |
1071 | } | |
1072 | ||
1073 | int ebt_register_target(struct ebt_target *target) | |
1074 | { | |
df0933dc | 1075 | struct ebt_target *t; |
1da177e4 LT |
1076 | int ret; |
1077 | ||
57b47a53 | 1078 | ret = mutex_lock_interruptible(&ebt_mutex); |
1da177e4 LT |
1079 | if (ret != 0) |
1080 | return ret; | |
df0933dc PM |
1081 | list_for_each_entry(t, &ebt_targets, list) { |
1082 | if (strcmp(t->name, target->name) == 0) { | |
1083 | mutex_unlock(&ebt_mutex); | |
1084 | return -EEXIST; | |
1085 | } | |
1da177e4 | 1086 | } |
df0933dc | 1087 | list_add(&target->list, &ebt_targets); |
57b47a53 | 1088 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1089 | |
1090 | return 0; | |
1091 | } | |
1092 | ||
1093 | void ebt_unregister_target(struct ebt_target *target) | |
1094 | { | |
57b47a53 | 1095 | mutex_lock(&ebt_mutex); |
df0933dc | 1096 | list_del(&target->list); |
57b47a53 | 1097 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1098 | } |
1099 | ||
1100 | int ebt_register_match(struct ebt_match *match) | |
1101 | { | |
df0933dc | 1102 | struct ebt_match *m; |
1da177e4 LT |
1103 | int ret; |
1104 | ||
57b47a53 | 1105 | ret = mutex_lock_interruptible(&ebt_mutex); |
1da177e4 LT |
1106 | if (ret != 0) |
1107 | return ret; | |
df0933dc PM |
1108 | list_for_each_entry(m, &ebt_matches, list) { |
1109 | if (strcmp(m->name, match->name) == 0) { | |
1110 | mutex_unlock(&ebt_mutex); | |
1111 | return -EEXIST; | |
1112 | } | |
1da177e4 | 1113 | } |
df0933dc | 1114 | list_add(&match->list, &ebt_matches); |
57b47a53 | 1115 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1116 | |
1117 | return 0; | |
1118 | } | |
1119 | ||
1120 | void ebt_unregister_match(struct ebt_match *match) | |
1121 | { | |
57b47a53 | 1122 | mutex_lock(&ebt_mutex); |
df0933dc | 1123 | list_del(&match->list); |
57b47a53 | 1124 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1125 | } |
1126 | ||
1127 | int ebt_register_watcher(struct ebt_watcher *watcher) | |
1128 | { | |
df0933dc | 1129 | struct ebt_watcher *w; |
1da177e4 LT |
1130 | int ret; |
1131 | ||
57b47a53 | 1132 | ret = mutex_lock_interruptible(&ebt_mutex); |
1da177e4 LT |
1133 | if (ret != 0) |
1134 | return ret; | |
df0933dc PM |
1135 | list_for_each_entry(w, &ebt_watchers, list) { |
1136 | if (strcmp(w->name, watcher->name) == 0) { | |
1137 | mutex_unlock(&ebt_mutex); | |
1138 | return -EEXIST; | |
1139 | } | |
1da177e4 | 1140 | } |
df0933dc | 1141 | list_add(&watcher->list, &ebt_watchers); |
57b47a53 | 1142 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1143 | |
1144 | return 0; | |
1145 | } | |
1146 | ||
1147 | void ebt_unregister_watcher(struct ebt_watcher *watcher) | |
1148 | { | |
57b47a53 | 1149 | mutex_lock(&ebt_mutex); |
df0933dc | 1150 | list_del(&watcher->list); |
57b47a53 | 1151 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1152 | } |
1153 | ||
1154 | int ebt_register_table(struct ebt_table *table) | |
1155 | { | |
1156 | struct ebt_table_info *newinfo; | |
df0933dc | 1157 | struct ebt_table *t; |
1e419cd9 | 1158 | struct ebt_replace_kernel *repl; |
1da177e4 | 1159 | int ret, i, countersize; |
df07a81e | 1160 | void *p; |
1da177e4 | 1161 | |
df07a81e AV |
1162 | if (!table || !(repl = table->table) || !repl->entries || |
1163 | repl->entries_size == 0 || | |
1164 | repl->counters || table->private) { | |
1da177e4 LT |
1165 | BUGPRINT("Bad table data for ebt_register_table!!!\n"); |
1166 | return -EINVAL; | |
1167 | } | |
1168 | ||
53b8a315 | 1169 | countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids; |
18bc89aa | 1170 | newinfo = vmalloc(sizeof(*newinfo) + countersize); |
1da177e4 LT |
1171 | ret = -ENOMEM; |
1172 | if (!newinfo) | |
1173 | return -ENOMEM; | |
1174 | ||
df07a81e AV |
1175 | p = vmalloc(repl->entries_size); |
1176 | if (!p) | |
1da177e4 LT |
1177 | goto free_newinfo; |
1178 | ||
df07a81e AV |
1179 | memcpy(p, repl->entries, repl->entries_size); |
1180 | newinfo->entries = p; | |
1181 | ||
1182 | newinfo->entries_size = repl->entries_size; | |
1183 | newinfo->nentries = repl->nentries; | |
1da177e4 LT |
1184 | |
1185 | if (countersize) | |
1186 | memset(newinfo->counters, 0, countersize); | |
1187 | ||
1188 | /* fill in newinfo and parse the entries */ | |
1189 | newinfo->chainstack = NULL; | |
df07a81e AV |
1190 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { |
1191 | if ((repl->valid_hooks & (1 << i)) == 0) | |
1192 | newinfo->hook_entry[i] = NULL; | |
1193 | else | |
1194 | newinfo->hook_entry[i] = p + | |
1195 | ((char *)repl->hook_entry[i] - repl->entries); | |
1196 | } | |
1197 | ret = translate_table(repl->name, newinfo); | |
1da177e4 LT |
1198 | if (ret != 0) { |
1199 | BUGPRINT("Translate_table failed\n"); | |
1200 | goto free_chainstack; | |
1201 | } | |
1202 | ||
1203 | if (table->check && table->check(newinfo, table->valid_hooks)) { | |
1204 | BUGPRINT("The table doesn't like its own initial data, lol\n"); | |
1205 | return -EINVAL; | |
1206 | } | |
1207 | ||
1208 | table->private = newinfo; | |
1209 | rwlock_init(&table->lock); | |
57b47a53 | 1210 | ret = mutex_lock_interruptible(&ebt_mutex); |
1da177e4 LT |
1211 | if (ret != 0) |
1212 | goto free_chainstack; | |
1213 | ||
df0933dc PM |
1214 | list_for_each_entry(t, &ebt_tables, list) { |
1215 | if (strcmp(t->name, table->name) == 0) { | |
1216 | ret = -EEXIST; | |
1217 | BUGPRINT("Table name already exists\n"); | |
1218 | goto free_unlock; | |
1219 | } | |
1da177e4 LT |
1220 | } |
1221 | ||
1222 | /* Hold a reference count if the chains aren't empty */ | |
1223 | if (newinfo->nentries && !try_module_get(table->me)) { | |
1224 | ret = -ENOENT; | |
1225 | goto free_unlock; | |
1226 | } | |
df0933dc | 1227 | list_add(&table->list, &ebt_tables); |
57b47a53 | 1228 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1229 | return 0; |
1230 | free_unlock: | |
57b47a53 | 1231 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1232 | free_chainstack: |
1233 | if (newinfo->chainstack) { | |
6f912042 | 1234 | for_each_possible_cpu(i) |
1da177e4 LT |
1235 | vfree(newinfo->chainstack[i]); |
1236 | vfree(newinfo->chainstack); | |
1237 | } | |
1238 | vfree(newinfo->entries); | |
1239 | free_newinfo: | |
1240 | vfree(newinfo); | |
1241 | return ret; | |
1242 | } | |
1243 | ||
1244 | void ebt_unregister_table(struct ebt_table *table) | |
1245 | { | |
1246 | int i; | |
1247 | ||
1248 | if (!table) { | |
1249 | BUGPRINT("Request to unregister NULL table!!!\n"); | |
1250 | return; | |
1251 | } | |
57b47a53 | 1252 | mutex_lock(&ebt_mutex); |
df0933dc | 1253 | list_del(&table->list); |
57b47a53 | 1254 | mutex_unlock(&ebt_mutex); |
68d31872 | 1255 | vfree(table->private->entries); |
1da177e4 | 1256 | if (table->private->chainstack) { |
6f912042 | 1257 | for_each_possible_cpu(i) |
1da177e4 LT |
1258 | vfree(table->private->chainstack[i]); |
1259 | vfree(table->private->chainstack); | |
1260 | } | |
1261 | vfree(table->private); | |
1262 | } | |
1263 | ||
1264 | /* userspace just supplied us with counters */ | |
1265 | static int update_counters(void __user *user, unsigned int len) | |
1266 | { | |
1267 | int i, ret; | |
1268 | struct ebt_counter *tmp; | |
1269 | struct ebt_replace hlp; | |
1270 | struct ebt_table *t; | |
1271 | ||
1272 | if (copy_from_user(&hlp, user, sizeof(hlp))) | |
1273 | return -EFAULT; | |
1274 | ||
1275 | if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter)) | |
1276 | return -EINVAL; | |
1277 | if (hlp.num_counters == 0) | |
1278 | return -EINVAL; | |
1279 | ||
18bc89aa | 1280 | if (!(tmp = vmalloc(hlp.num_counters * sizeof(*tmp)))) { |
1da177e4 LT |
1281 | MEMPRINT("Update_counters && nomemory\n"); |
1282 | return -ENOMEM; | |
1283 | } | |
1284 | ||
1285 | t = find_table_lock(hlp.name, &ret, &ebt_mutex); | |
1286 | if (!t) | |
1287 | goto free_tmp; | |
1288 | ||
1289 | if (hlp.num_counters != t->private->nentries) { | |
1290 | BUGPRINT("Wrong nr of counters\n"); | |
1291 | ret = -EINVAL; | |
1292 | goto unlock_mutex; | |
1293 | } | |
1294 | ||
1295 | if ( copy_from_user(tmp, hlp.counters, | |
1296 | hlp.num_counters * sizeof(struct ebt_counter)) ) { | |
1297 | BUGPRINT("Updata_counters && !cfu\n"); | |
1298 | ret = -EFAULT; | |
1299 | goto unlock_mutex; | |
1300 | } | |
1301 | ||
1302 | /* we want an atomic add of the counters */ | |
1303 | write_lock_bh(&t->lock); | |
1304 | ||
1305 | /* we add to the counters of the first cpu */ | |
1306 | for (i = 0; i < hlp.num_counters; i++) { | |
1307 | t->private->counters[i].pcnt += tmp[i].pcnt; | |
1308 | t->private->counters[i].bcnt += tmp[i].bcnt; | |
1309 | } | |
1310 | ||
1311 | write_unlock_bh(&t->lock); | |
1312 | ret = 0; | |
1313 | unlock_mutex: | |
57b47a53 | 1314 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1315 | free_tmp: |
1316 | vfree(tmp); | |
1317 | return ret; | |
1318 | } | |
1319 | ||
1320 | static inline int ebt_make_matchname(struct ebt_entry_match *m, | |
1e419cd9 | 1321 | char *base, char __user *ubase) |
1da177e4 | 1322 | { |
1e419cd9 | 1323 | char __user *hlp = ubase + ((char *)m - base); |
1da177e4 LT |
1324 | if (copy_to_user(hlp, m->u.match->name, EBT_FUNCTION_MAXNAMELEN)) |
1325 | return -EFAULT; | |
1326 | return 0; | |
1327 | } | |
1328 | ||
1329 | static inline int ebt_make_watchername(struct ebt_entry_watcher *w, | |
1e419cd9 | 1330 | char *base, char __user *ubase) |
1da177e4 | 1331 | { |
1e419cd9 | 1332 | char __user *hlp = ubase + ((char *)w - base); |
1da177e4 LT |
1333 | if (copy_to_user(hlp , w->u.watcher->name, EBT_FUNCTION_MAXNAMELEN)) |
1334 | return -EFAULT; | |
1335 | return 0; | |
1336 | } | |
1337 | ||
1e419cd9 | 1338 | static inline int ebt_make_names(struct ebt_entry *e, char *base, char __user *ubase) |
1da177e4 LT |
1339 | { |
1340 | int ret; | |
1e419cd9 | 1341 | char __user *hlp; |
1da177e4 LT |
1342 | struct ebt_entry_target *t; |
1343 | ||
40642f95 | 1344 | if (e->bitmask == 0) |
1da177e4 LT |
1345 | return 0; |
1346 | ||
1e419cd9 | 1347 | hlp = ubase + (((char *)e + e->target_offset) - base); |
1da177e4 | 1348 | t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); |
9d6f229f | 1349 | |
1da177e4 LT |
1350 | ret = EBT_MATCH_ITERATE(e, ebt_make_matchname, base, ubase); |
1351 | if (ret != 0) | |
1352 | return ret; | |
1353 | ret = EBT_WATCHER_ITERATE(e, ebt_make_watchername, base, ubase); | |
1354 | if (ret != 0) | |
1355 | return ret; | |
1356 | if (copy_to_user(hlp, t->u.target->name, EBT_FUNCTION_MAXNAMELEN)) | |
1357 | return -EFAULT; | |
1358 | return 0; | |
1359 | } | |
1360 | ||
57b47a53 | 1361 | /* called with ebt_mutex locked */ |
1da177e4 LT |
1362 | static int copy_everything_to_user(struct ebt_table *t, void __user *user, |
1363 | int *len, int cmd) | |
1364 | { | |
1365 | struct ebt_replace tmp; | |
1366 | struct ebt_counter *counterstmp, *oldcounters; | |
1367 | unsigned int entries_size, nentries; | |
1368 | char *entries; | |
1369 | ||
1370 | if (cmd == EBT_SO_GET_ENTRIES) { | |
1371 | entries_size = t->private->entries_size; | |
1372 | nentries = t->private->nentries; | |
1373 | entries = t->private->entries; | |
1374 | oldcounters = t->private->counters; | |
1375 | } else { | |
1376 | entries_size = t->table->entries_size; | |
1377 | nentries = t->table->nentries; | |
1378 | entries = t->table->entries; | |
1379 | oldcounters = t->table->counters; | |
1380 | } | |
1381 | ||
1382 | if (copy_from_user(&tmp, user, sizeof(tmp))) { | |
1383 | BUGPRINT("Cfu didn't work\n"); | |
1384 | return -EFAULT; | |
1385 | } | |
1386 | ||
1387 | if (*len != sizeof(struct ebt_replace) + entries_size + | |
1388 | (tmp.num_counters? nentries * sizeof(struct ebt_counter): 0)) { | |
1389 | BUGPRINT("Wrong size\n"); | |
1390 | return -EINVAL; | |
1391 | } | |
1392 | ||
1393 | if (tmp.nentries != nentries) { | |
1394 | BUGPRINT("Nentries wrong\n"); | |
1395 | return -EINVAL; | |
1396 | } | |
1397 | ||
1398 | if (tmp.entries_size != entries_size) { | |
1399 | BUGPRINT("Wrong size\n"); | |
1400 | return -EINVAL; | |
1401 | } | |
1402 | ||
1403 | /* userspace might not need the counters */ | |
1404 | if (tmp.num_counters) { | |
1405 | if (tmp.num_counters != nentries) { | |
1406 | BUGPRINT("Num_counters wrong\n"); | |
1407 | return -EINVAL; | |
1408 | } | |
18bc89aa | 1409 | counterstmp = vmalloc(nentries * sizeof(*counterstmp)); |
1da177e4 LT |
1410 | if (!counterstmp) { |
1411 | MEMPRINT("Couldn't copy counters, out of memory\n"); | |
1412 | return -ENOMEM; | |
1413 | } | |
1414 | write_lock_bh(&t->lock); | |
1415 | get_counters(oldcounters, counterstmp, nentries); | |
1416 | write_unlock_bh(&t->lock); | |
1417 | ||
1418 | if (copy_to_user(tmp.counters, counterstmp, | |
1419 | nentries * sizeof(struct ebt_counter))) { | |
1420 | BUGPRINT("Couldn't copy counters to userspace\n"); | |
1421 | vfree(counterstmp); | |
1422 | return -EFAULT; | |
1423 | } | |
1424 | vfree(counterstmp); | |
1425 | } | |
1426 | ||
1427 | if (copy_to_user(tmp.entries, entries, entries_size)) { | |
1428 | BUGPRINT("Couldn't copy entries to userspace\n"); | |
1429 | return -EFAULT; | |
1430 | } | |
1431 | /* set the match/watcher/target names right */ | |
1432 | return EBT_ENTRY_ITERATE(entries, entries_size, | |
1433 | ebt_make_names, entries, tmp.entries); | |
1434 | } | |
1435 | ||
1436 | static int do_ebt_set_ctl(struct sock *sk, | |
1437 | int cmd, void __user *user, unsigned int len) | |
1438 | { | |
1439 | int ret; | |
1440 | ||
1441 | switch(cmd) { | |
1442 | case EBT_SO_SET_ENTRIES: | |
1443 | ret = do_replace(user, len); | |
1444 | break; | |
1445 | case EBT_SO_SET_COUNTERS: | |
1446 | ret = update_counters(user, len); | |
1447 | break; | |
1448 | default: | |
1449 | ret = -EINVAL; | |
1450 | } | |
1451 | return ret; | |
1452 | } | |
1453 | ||
1454 | static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) | |
1455 | { | |
1456 | int ret; | |
1457 | struct ebt_replace tmp; | |
1458 | struct ebt_table *t; | |
1459 | ||
1460 | if (copy_from_user(&tmp, user, sizeof(tmp))) | |
1461 | return -EFAULT; | |
1462 | ||
1463 | t = find_table_lock(tmp.name, &ret, &ebt_mutex); | |
1464 | if (!t) | |
1465 | return ret; | |
1466 | ||
1467 | switch(cmd) { | |
1468 | case EBT_SO_GET_INFO: | |
1469 | case EBT_SO_GET_INIT_INFO: | |
1470 | if (*len != sizeof(struct ebt_replace)){ | |
1471 | ret = -EINVAL; | |
57b47a53 | 1472 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1473 | break; |
1474 | } | |
1475 | if (cmd == EBT_SO_GET_INFO) { | |
1476 | tmp.nentries = t->private->nentries; | |
1477 | tmp.entries_size = t->private->entries_size; | |
1478 | tmp.valid_hooks = t->valid_hooks; | |
1479 | } else { | |
1480 | tmp.nentries = t->table->nentries; | |
1481 | tmp.entries_size = t->table->entries_size; | |
1482 | tmp.valid_hooks = t->table->valid_hooks; | |
1483 | } | |
57b47a53 | 1484 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1485 | if (copy_to_user(user, &tmp, *len) != 0){ |
1486 | BUGPRINT("c2u Didn't work\n"); | |
1487 | ret = -EFAULT; | |
1488 | break; | |
1489 | } | |
1490 | ret = 0; | |
1491 | break; | |
1492 | ||
1493 | case EBT_SO_GET_ENTRIES: | |
1494 | case EBT_SO_GET_INIT_ENTRIES: | |
1495 | ret = copy_everything_to_user(t, user, len, cmd); | |
57b47a53 | 1496 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1497 | break; |
1498 | ||
1499 | default: | |
57b47a53 | 1500 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1501 | ret = -EINVAL; |
1502 | } | |
1503 | ||
1504 | return ret; | |
1505 | } | |
1506 | ||
1507 | static struct nf_sockopt_ops ebt_sockopts = | |
74ca4e5a AM |
1508 | { |
1509 | .pf = PF_INET, | |
1510 | .set_optmin = EBT_BASE_CTL, | |
1511 | .set_optmax = EBT_SO_SET_MAX + 1, | |
1512 | .set = do_ebt_set_ctl, | |
1513 | .get_optmin = EBT_BASE_CTL, | |
1514 | .get_optmax = EBT_SO_GET_MAX + 1, | |
1515 | .get = do_ebt_get_ctl, | |
16fcec35 | 1516 | .owner = THIS_MODULE, |
1da177e4 LT |
1517 | }; |
1518 | ||
65b4b4e8 | 1519 | static int __init ebtables_init(void) |
1da177e4 LT |
1520 | { |
1521 | int ret; | |
1522 | ||
57b47a53 | 1523 | mutex_lock(&ebt_mutex); |
df0933dc | 1524 | list_add(&ebt_standard_target.list, &ebt_targets); |
57b47a53 | 1525 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1526 | if ((ret = nf_register_sockopt(&ebt_sockopts)) < 0) |
1527 | return ret; | |
1528 | ||
a887c1c1 | 1529 | printk(KERN_INFO "Ebtables v2.0 registered\n"); |
1da177e4 LT |
1530 | return 0; |
1531 | } | |
1532 | ||
65b4b4e8 | 1533 | static void __exit ebtables_fini(void) |
1da177e4 LT |
1534 | { |
1535 | nf_unregister_sockopt(&ebt_sockopts); | |
a887c1c1 | 1536 | printk(KERN_INFO "Ebtables v2.0 unregistered\n"); |
1da177e4 LT |
1537 | } |
1538 | ||
1539 | EXPORT_SYMBOL(ebt_register_table); | |
1540 | EXPORT_SYMBOL(ebt_unregister_table); | |
1541 | EXPORT_SYMBOL(ebt_register_match); | |
1542 | EXPORT_SYMBOL(ebt_unregister_match); | |
1543 | EXPORT_SYMBOL(ebt_register_watcher); | |
1544 | EXPORT_SYMBOL(ebt_unregister_watcher); | |
1545 | EXPORT_SYMBOL(ebt_register_target); | |
1546 | EXPORT_SYMBOL(ebt_unregister_target); | |
1547 | EXPORT_SYMBOL(ebt_do_table); | |
65b4b4e8 AM |
1548 | module_init(ebtables_init); |
1549 | module_exit(ebtables_fini); | |
1da177e4 | 1550 | MODULE_LICENSE("GPL"); |