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 | ||
1da177e4 LT |
18 | |
19 | #include <linux/kmod.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/vmalloc.h> | |
18219d3f | 22 | #include <linux/netfilter/x_tables.h> |
1da177e4 LT |
23 | #include <linux/netfilter_bridge/ebtables.h> |
24 | #include <linux/spinlock.h> | |
df0933dc | 25 | #include <linux/mutex.h> |
1da177e4 LT |
26 | #include <asm/uaccess.h> |
27 | #include <linux/smp.h> | |
c8923c6b | 28 | #include <linux/cpumask.h> |
1da177e4 LT |
29 | #include <net/sock.h> |
30 | /* needed for logical [in,out]-dev filtering */ | |
31 | #include "../br_private.h" | |
32 | ||
1da177e4 | 33 | #define BUGPRINT(format, args...) printk("kernel msg: ebtables bug: please "\ |
9d6f229f | 34 | "report to author: "format, ## args) |
1da177e4 | 35 | /* #define BUGPRINT(format, args...) */ |
1da177e4 | 36 | #define MEMPRINT(format, args...) printk("kernel msg: ebtables "\ |
9d6f229f | 37 | ": out of memory: "format, ## args) |
1da177e4 LT |
38 | /* #define MEMPRINT(format, args...) */ |
39 | ||
40 | ||
41 | ||
42 | /* | |
43 | * Each cpu has its own set of counters, so there is no need for write_lock in | |
44 | * the softirq | |
45 | * For reading or updating the counters, the user context needs to | |
46 | * get a write_lock | |
47 | */ | |
48 | ||
49 | /* The size of each set of counters is altered to get cache alignment */ | |
50 | #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1)) | |
51 | #define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter))) | |
52 | #define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \ | |
53 | COUNTER_OFFSET(n) * cpu)) | |
54 | ||
55 | ||
56 | ||
57b47a53 | 57 | static DEFINE_MUTEX(ebt_mutex); |
1da177e4 | 58 | static LIST_HEAD(ebt_tables); |
1da177e4 | 59 | |
043ef46c | 60 | static struct xt_target ebt_standard_target = { |
001a18d3 JE |
61 | .name = "standard", |
62 | .revision = 0, | |
63 | .family = NFPROTO_BRIDGE, | |
043ef46c | 64 | .targetsize = sizeof(int), |
18219d3f | 65 | }; |
1da177e4 | 66 | |
7eb35586 JE |
67 | static inline int |
68 | ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb, | |
69 | struct xt_target_param *par) | |
1da177e4 | 70 | { |
7eb35586 JE |
71 | par->target = w->u.watcher; |
72 | par->targinfo = w->data; | |
73 | w->u.watcher->target(skb, par); | |
1da177e4 LT |
74 | /* watchers don't give a verdict */ |
75 | return 0; | |
76 | } | |
77 | ||
78 | static inline int ebt_do_match (struct ebt_entry_match *m, | |
f7108a20 | 79 | const struct sk_buff *skb, struct xt_match_param *par) |
1da177e4 | 80 | { |
f7108a20 JE |
81 | par->match = m->u.match; |
82 | par->matchinfo = m->data; | |
83 | return m->u.match->match(skb, par); | |
1da177e4 LT |
84 | } |
85 | ||
86 | static inline int ebt_dev_check(char *entry, const struct net_device *device) | |
87 | { | |
88 | int i = 0; | |
6f5b7ef6 | 89 | const char *devname = device->name; |
1da177e4 LT |
90 | |
91 | if (*entry == '\0') | |
92 | return 0; | |
93 | if (!device) | |
94 | return 1; | |
95 | /* 1 is the wildcard token */ | |
96 | while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i]) | |
97 | i++; | |
98 | return (devname[i] != entry[i] && entry[i] != 1); | |
99 | } | |
100 | ||
101 | #define FWINV2(bool,invflg) ((bool) ^ !!(e->invflags & invflg)) | |
102 | /* process standard matches */ | |
103 | static inline int ebt_basic_match(struct ebt_entry *e, struct ethhdr *h, | |
104 | const struct net_device *in, const struct net_device *out) | |
105 | { | |
106 | int verdict, i; | |
107 | ||
108 | if (e->bitmask & EBT_802_3) { | |
109 | if (FWINV2(ntohs(h->h_proto) >= 1536, EBT_IPROTO)) | |
110 | return 1; | |
111 | } else if (!(e->bitmask & EBT_NOPROTO) && | |
112 | FWINV2(e->ethproto != h->h_proto, EBT_IPROTO)) | |
113 | return 1; | |
114 | ||
115 | if (FWINV2(ebt_dev_check(e->in, in), EBT_IIN)) | |
116 | return 1; | |
117 | if (FWINV2(ebt_dev_check(e->out, out), EBT_IOUT)) | |
118 | return 1; | |
119 | if ((!in || !in->br_port) ? 0 : FWINV2(ebt_dev_check( | |
120 | e->logical_in, in->br_port->br->dev), EBT_ILOGICALIN)) | |
121 | return 1; | |
122 | if ((!out || !out->br_port) ? 0 : FWINV2(ebt_dev_check( | |
123 | e->logical_out, out->br_port->br->dev), EBT_ILOGICALOUT)) | |
124 | return 1; | |
125 | ||
126 | if (e->bitmask & EBT_SOURCEMAC) { | |
127 | verdict = 0; | |
128 | for (i = 0; i < 6; i++) | |
129 | verdict |= (h->h_source[i] ^ e->sourcemac[i]) & | |
130 | e->sourcemsk[i]; | |
131 | if (FWINV2(verdict != 0, EBT_ISOURCE) ) | |
132 | return 1; | |
133 | } | |
134 | if (e->bitmask & EBT_DESTMAC) { | |
135 | verdict = 0; | |
136 | for (i = 0; i < 6; i++) | |
137 | verdict |= (h->h_dest[i] ^ e->destmac[i]) & | |
138 | e->destmsk[i]; | |
139 | if (FWINV2(verdict != 0, EBT_IDEST) ) | |
140 | return 1; | |
141 | } | |
142 | return 0; | |
143 | } | |
144 | ||
145 | /* Do some firewalling */ | |
3db05fea | 146 | unsigned int ebt_do_table (unsigned int hook, struct sk_buff *skb, |
1da177e4 LT |
147 | const struct net_device *in, const struct net_device *out, |
148 | struct ebt_table *table) | |
149 | { | |
150 | int i, nentries; | |
151 | struct ebt_entry *point; | |
152 | struct ebt_counter *counter_base, *cb_base; | |
153 | struct ebt_entry_target *t; | |
154 | int verdict, sp = 0; | |
155 | struct ebt_chainstack *cs; | |
156 | struct ebt_entries *chaininfo; | |
157 | char *base; | |
158 | struct ebt_table_info *private; | |
5365f802 | 159 | bool hotdrop = false; |
f7108a20 | 160 | struct xt_match_param mtpar; |
7eb35586 | 161 | struct xt_target_param tgpar; |
f7108a20 | 162 | |
7eb35586 JE |
163 | mtpar.in = tgpar.in = in; |
164 | mtpar.out = tgpar.out = out; | |
f7108a20 | 165 | mtpar.hotdrop = &hotdrop; |
7eb35586 | 166 | tgpar.hooknum = hook; |
1da177e4 LT |
167 | |
168 | read_lock_bh(&table->lock); | |
169 | private = table->private; | |
170 | cb_base = COUNTER_BASE(private->counters, private->nentries, | |
171 | smp_processor_id()); | |
172 | if (private->chainstack) | |
173 | cs = private->chainstack[smp_processor_id()]; | |
174 | else | |
175 | cs = NULL; | |
176 | chaininfo = private->hook_entry[hook]; | |
177 | nentries = private->hook_entry[hook]->nentries; | |
178 | point = (struct ebt_entry *)(private->hook_entry[hook]->data); | |
179 | counter_base = cb_base + private->hook_entry[hook]->counter_offset; | |
180 | /* base for chain jumps */ | |
181 | base = private->entries; | |
182 | i = 0; | |
183 | while (i < nentries) { | |
3db05fea | 184 | if (ebt_basic_match(point, eth_hdr(skb), in, out)) |
1da177e4 LT |
185 | goto letscontinue; |
186 | ||
f7108a20 | 187 | if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &mtpar) != 0) |
1da177e4 | 188 | goto letscontinue; |
5365f802 JE |
189 | if (hotdrop) { |
190 | read_unlock_bh(&table->lock); | |
191 | return NF_DROP; | |
192 | } | |
1da177e4 LT |
193 | |
194 | /* increase counter */ | |
195 | (*(counter_base + i)).pcnt++; | |
3db05fea | 196 | (*(counter_base + i)).bcnt += skb->len; |
1da177e4 LT |
197 | |
198 | /* these should only watch: not modify, nor tell us | |
199 | what to do with the packet */ | |
7eb35586 | 200 | EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &tgpar); |
1da177e4 LT |
201 | |
202 | t = (struct ebt_entry_target *) | |
203 | (((char *)point) + point->target_offset); | |
204 | /* standard target */ | |
205 | if (!t->u.target->target) | |
206 | verdict = ((struct ebt_standard_target *)t)->verdict; | |
7eb35586 JE |
207 | else { |
208 | tgpar.target = t->u.target; | |
209 | tgpar.targinfo = t->data; | |
210 | verdict = t->u.target->target(skb, &tgpar); | |
211 | } | |
1da177e4 LT |
212 | if (verdict == EBT_ACCEPT) { |
213 | read_unlock_bh(&table->lock); | |
214 | return NF_ACCEPT; | |
215 | } | |
216 | if (verdict == EBT_DROP) { | |
217 | read_unlock_bh(&table->lock); | |
218 | return NF_DROP; | |
219 | } | |
220 | if (verdict == EBT_RETURN) { | |
221 | letsreturn: | |
222 | #ifdef CONFIG_NETFILTER_DEBUG | |
223 | if (sp == 0) { | |
224 | BUGPRINT("RETURN on base chain"); | |
225 | /* act like this is EBT_CONTINUE */ | |
226 | goto letscontinue; | |
227 | } | |
228 | #endif | |
229 | sp--; | |
230 | /* put all the local variables right */ | |
231 | i = cs[sp].n; | |
232 | chaininfo = cs[sp].chaininfo; | |
233 | nentries = chaininfo->nentries; | |
234 | point = cs[sp].e; | |
235 | counter_base = cb_base + | |
236 | chaininfo->counter_offset; | |
237 | continue; | |
238 | } | |
239 | if (verdict == EBT_CONTINUE) | |
240 | goto letscontinue; | |
241 | #ifdef CONFIG_NETFILTER_DEBUG | |
242 | if (verdict < 0) { | |
243 | BUGPRINT("bogus standard verdict\n"); | |
244 | read_unlock_bh(&table->lock); | |
245 | return NF_DROP; | |
246 | } | |
247 | #endif | |
248 | /* jump to a udc */ | |
249 | cs[sp].n = i + 1; | |
250 | cs[sp].chaininfo = chaininfo; | |
251 | cs[sp].e = (struct ebt_entry *) | |
252 | (((char *)point) + point->next_offset); | |
253 | i = 0; | |
254 | chaininfo = (struct ebt_entries *) (base + verdict); | |
255 | #ifdef CONFIG_NETFILTER_DEBUG | |
256 | if (chaininfo->distinguisher) { | |
257 | BUGPRINT("jump to non-chain\n"); | |
258 | read_unlock_bh(&table->lock); | |
259 | return NF_DROP; | |
260 | } | |
261 | #endif | |
262 | nentries = chaininfo->nentries; | |
263 | point = (struct ebt_entry *)chaininfo->data; | |
264 | counter_base = cb_base + chaininfo->counter_offset; | |
265 | sp++; | |
266 | continue; | |
267 | letscontinue: | |
268 | point = (struct ebt_entry *) | |
269 | (((char *)point) + point->next_offset); | |
270 | i++; | |
271 | } | |
272 | ||
273 | /* I actually like this :) */ | |
274 | if (chaininfo->policy == EBT_RETURN) | |
275 | goto letsreturn; | |
276 | if (chaininfo->policy == EBT_ACCEPT) { | |
277 | read_unlock_bh(&table->lock); | |
278 | return NF_ACCEPT; | |
279 | } | |
280 | read_unlock_bh(&table->lock); | |
281 | return NF_DROP; | |
282 | } | |
283 | ||
284 | /* If it succeeds, returns element and locks mutex */ | |
285 | static inline void * | |
286 | find_inlist_lock_noload(struct list_head *head, const char *name, int *error, | |
57b47a53 | 287 | struct mutex *mutex) |
1da177e4 | 288 | { |
df0933dc PM |
289 | struct { |
290 | struct list_head list; | |
291 | char name[EBT_FUNCTION_MAXNAMELEN]; | |
292 | } *e; | |
1da177e4 | 293 | |
57b47a53 | 294 | *error = mutex_lock_interruptible(mutex); |
1da177e4 LT |
295 | if (*error != 0) |
296 | return NULL; | |
297 | ||
df0933dc PM |
298 | list_for_each_entry(e, head, list) { |
299 | if (strcmp(e->name, name) == 0) | |
300 | return e; | |
1da177e4 | 301 | } |
df0933dc PM |
302 | *error = -ENOENT; |
303 | mutex_unlock(mutex); | |
304 | return NULL; | |
1da177e4 LT |
305 | } |
306 | ||
307 | #ifndef CONFIG_KMOD | |
308 | #define find_inlist_lock(h,n,p,e,m) find_inlist_lock_noload((h),(n),(e),(m)) | |
309 | #else | |
310 | static void * | |
311 | find_inlist_lock(struct list_head *head, const char *name, const char *prefix, | |
57b47a53 | 312 | int *error, struct mutex *mutex) |
1da177e4 LT |
313 | { |
314 | void *ret; | |
315 | ||
316 | ret = find_inlist_lock_noload(head, name, error, mutex); | |
317 | if (!ret) { | |
318 | request_module("%s%s", prefix, name); | |
319 | ret = find_inlist_lock_noload(head, name, error, mutex); | |
320 | } | |
321 | return ret; | |
322 | } | |
323 | #endif | |
324 | ||
325 | static inline struct ebt_table * | |
57b47a53 | 326 | find_table_lock(const char *name, int *error, struct mutex *mutex) |
1da177e4 LT |
327 | { |
328 | return find_inlist_lock(&ebt_tables, name, "ebtable_", error, mutex); | |
329 | } | |
330 | ||
1da177e4 | 331 | static inline int |
9b4fce7a JE |
332 | ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par, |
333 | unsigned int *cnt) | |
1da177e4 | 334 | { |
9b4fce7a | 335 | const struct ebt_entry *e = par->entryinfo; |
043ef46c | 336 | struct xt_match *match; |
14197d54 | 337 | size_t left = ((char *)e + e->watchers_offset) - (char *)m; |
1da177e4 LT |
338 | int ret; |
339 | ||
14197d54 AV |
340 | if (left < sizeof(struct ebt_entry_match) || |
341 | left - sizeof(struct ebt_entry_match) < m->match_size) | |
1da177e4 | 342 | return -EINVAL; |
043ef46c JE |
343 | |
344 | match = try_then_request_module(xt_find_match(NFPROTO_BRIDGE, | |
345 | m->u.name, 0), "ebt_%s", m->u.name); | |
346 | if (IS_ERR(match)) | |
347 | return PTR_ERR(match); | |
348 | if (match == NULL) | |
1da177e4 | 349 | return -ENOENT; |
043ef46c JE |
350 | m->u.match = match; |
351 | ||
9b4fce7a JE |
352 | par->match = match; |
353 | par->matchinfo = m->data; | |
354 | ret = xt_check_match(par, NFPROTO_BRIDGE, m->match_size, | |
355 | e->ethproto, e->invflags & EBT_IPROTO); | |
043ef46c JE |
356 | if (ret < 0) { |
357 | module_put(match->me); | |
358 | return ret; | |
1da177e4 | 359 | } |
043ef46c | 360 | |
1da177e4 LT |
361 | (*cnt)++; |
362 | return 0; | |
363 | } | |
364 | ||
365 | static inline int | |
af5d6dc2 JE |
366 | ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par, |
367 | unsigned int *cnt) | |
1da177e4 | 368 | { |
af5d6dc2 | 369 | const struct ebt_entry *e = par->entryinfo; |
043ef46c | 370 | struct xt_target *watcher; |
14197d54 | 371 | size_t left = ((char *)e + e->target_offset) - (char *)w; |
1da177e4 LT |
372 | int ret; |
373 | ||
14197d54 AV |
374 | if (left < sizeof(struct ebt_entry_watcher) || |
375 | left - sizeof(struct ebt_entry_watcher) < w->watcher_size) | |
1da177e4 | 376 | return -EINVAL; |
043ef46c JE |
377 | |
378 | watcher = try_then_request_module( | |
379 | xt_find_target(NFPROTO_BRIDGE, w->u.name, 0), | |
380 | "ebt_%s", w->u.name); | |
381 | if (IS_ERR(watcher)) | |
382 | return PTR_ERR(watcher); | |
383 | if (watcher == NULL) | |
1da177e4 | 384 | return -ENOENT; |
043ef46c JE |
385 | w->u.watcher = watcher; |
386 | ||
af5d6dc2 JE |
387 | par->target = watcher; |
388 | par->targinfo = w->data; | |
389 | ret = xt_check_target(par, NFPROTO_BRIDGE, w->watcher_size, | |
390 | e->ethproto, e->invflags & EBT_IPROTO); | |
043ef46c JE |
391 | if (ret < 0) { |
392 | module_put(watcher->me); | |
393 | return ret; | |
1da177e4 | 394 | } |
043ef46c | 395 | |
1da177e4 LT |
396 | (*cnt)++; |
397 | return 0; | |
398 | } | |
399 | ||
70fe9af4 AV |
400 | static int ebt_verify_pointers(struct ebt_replace *repl, |
401 | struct ebt_table_info *newinfo) | |
1da177e4 | 402 | { |
70fe9af4 AV |
403 | unsigned int limit = repl->entries_size; |
404 | unsigned int valid_hooks = repl->valid_hooks; | |
405 | unsigned int offset = 0; | |
1da177e4 LT |
406 | int i; |
407 | ||
e4fd77de AV |
408 | for (i = 0; i < NF_BR_NUMHOOKS; i++) |
409 | newinfo->hook_entry[i] = NULL; | |
410 | ||
411 | newinfo->entries_size = repl->entries_size; | |
412 | newinfo->nentries = repl->nentries; | |
413 | ||
70fe9af4 AV |
414 | while (offset < limit) { |
415 | size_t left = limit - offset; | |
416 | struct ebt_entry *e = (void *)newinfo->entries + offset; | |
bb2ef25c | 417 | |
70fe9af4 | 418 | if (left < sizeof(unsigned int)) |
1da177e4 | 419 | break; |
70fe9af4 AV |
420 | |
421 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
422 | if ((valid_hooks & (1 << i)) == 0) | |
423 | continue; | |
1e419cd9 AV |
424 | if ((char __user *)repl->hook_entry[i] == |
425 | repl->entries + offset) | |
70fe9af4 AV |
426 | break; |
427 | } | |
428 | ||
429 | if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) { | |
430 | if (e->bitmask != 0) { | |
431 | /* we make userspace set this right, | |
432 | so there is no misunderstanding */ | |
433 | BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set " | |
434 | "in distinguisher\n"); | |
435 | return -EINVAL; | |
436 | } | |
437 | if (i != NF_BR_NUMHOOKS) | |
438 | newinfo->hook_entry[i] = (struct ebt_entries *)e; | |
439 | if (left < sizeof(struct ebt_entries)) | |
440 | break; | |
441 | offset += sizeof(struct ebt_entries); | |
442 | } else { | |
443 | if (left < sizeof(struct ebt_entry)) | |
444 | break; | |
445 | if (left < e->next_offset) | |
446 | break; | |
447 | offset += e->next_offset; | |
1da177e4 | 448 | } |
22b440bf | 449 | } |
70fe9af4 AV |
450 | if (offset != limit) { |
451 | BUGPRINT("entries_size too small\n"); | |
452 | return -EINVAL; | |
453 | } | |
e4fd77de AV |
454 | |
455 | /* check if all valid hooks have a chain */ | |
456 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
457 | if (!newinfo->hook_entry[i] && | |
458 | (valid_hooks & (1 << i))) { | |
459 | BUGPRINT("Valid hook without chain\n"); | |
460 | return -EINVAL; | |
461 | } | |
462 | } | |
22b440bf | 463 | return 0; |
22b440bf AV |
464 | } |
465 | ||
466 | /* | |
467 | * this one is very careful, as it is the first function | |
468 | * to parse the userspace data | |
469 | */ | |
470 | static inline int | |
471 | ebt_check_entry_size_and_hooks(struct ebt_entry *e, | |
0e795531 AV |
472 | struct ebt_table_info *newinfo, |
473 | unsigned int *n, unsigned int *cnt, | |
474 | unsigned int *totalcnt, unsigned int *udc_cnt) | |
22b440bf | 475 | { |
22b440bf AV |
476 | int i; |
477 | ||
478 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
0e795531 | 479 | if ((void *)e == (void *)newinfo->hook_entry[i]) |
22b440bf AV |
480 | break; |
481 | } | |
482 | /* beginning of a new chain | |
483 | if i == NF_BR_NUMHOOKS it must be a user defined chain */ | |
484 | if (i != NF_BR_NUMHOOKS || !e->bitmask) { | |
1da177e4 LT |
485 | /* this checks if the previous chain has as many entries |
486 | as it said it has */ | |
487 | if (*n != *cnt) { | |
488 | BUGPRINT("nentries does not equal the nr of entries " | |
9d6f229f | 489 | "in the chain\n"); |
1da177e4 LT |
490 | return -EINVAL; |
491 | } | |
1da177e4 LT |
492 | if (((struct ebt_entries *)e)->policy != EBT_DROP && |
493 | ((struct ebt_entries *)e)->policy != EBT_ACCEPT) { | |
494 | /* only RETURN from udc */ | |
495 | if (i != NF_BR_NUMHOOKS || | |
496 | ((struct ebt_entries *)e)->policy != EBT_RETURN) { | |
497 | BUGPRINT("bad policy\n"); | |
498 | return -EINVAL; | |
499 | } | |
500 | } | |
501 | if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */ | |
502 | (*udc_cnt)++; | |
1da177e4 LT |
503 | if (((struct ebt_entries *)e)->counter_offset != *totalcnt) { |
504 | BUGPRINT("counter_offset != totalcnt"); | |
505 | return -EINVAL; | |
506 | } | |
507 | *n = ((struct ebt_entries *)e)->nentries; | |
508 | *cnt = 0; | |
509 | return 0; | |
510 | } | |
511 | /* a plain old entry, heh */ | |
512 | if (sizeof(struct ebt_entry) > e->watchers_offset || | |
513 | e->watchers_offset > e->target_offset || | |
514 | e->target_offset >= e->next_offset) { | |
515 | BUGPRINT("entry offsets not in right order\n"); | |
516 | return -EINVAL; | |
517 | } | |
518 | /* this is not checked anywhere else */ | |
519 | if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target)) { | |
520 | BUGPRINT("target size too small\n"); | |
521 | return -EINVAL; | |
522 | } | |
1da177e4 LT |
523 | (*cnt)++; |
524 | (*totalcnt)++; | |
525 | return 0; | |
526 | } | |
527 | ||
528 | struct ebt_cl_stack | |
529 | { | |
530 | struct ebt_chainstack cs; | |
531 | int from; | |
532 | unsigned int hookmask; | |
533 | }; | |
534 | ||
535 | /* | |
536 | * we need these positions to check that the jumps to a different part of the | |
537 | * entries is a jump to the beginning of a new chain. | |
538 | */ | |
539 | static inline int | |
540 | ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo, | |
177abc34 | 541 | unsigned int *n, struct ebt_cl_stack *udc) |
1da177e4 LT |
542 | { |
543 | int i; | |
544 | ||
545 | /* we're only interested in chain starts */ | |
40642f95 | 546 | if (e->bitmask) |
1da177e4 LT |
547 | return 0; |
548 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
1da177e4 LT |
549 | if (newinfo->hook_entry[i] == (struct ebt_entries *)e) |
550 | break; | |
551 | } | |
552 | /* only care about udc */ | |
553 | if (i != NF_BR_NUMHOOKS) | |
554 | return 0; | |
555 | ||
556 | udc[*n].cs.chaininfo = (struct ebt_entries *)e; | |
557 | /* these initialisations are depended on later in check_chainloops() */ | |
558 | udc[*n].cs.n = 0; | |
559 | udc[*n].hookmask = 0; | |
560 | ||
561 | (*n)++; | |
562 | return 0; | |
563 | } | |
564 | ||
565 | static inline int | |
566 | ebt_cleanup_match(struct ebt_entry_match *m, unsigned int *i) | |
567 | { | |
6be3d859 JE |
568 | struct xt_mtdtor_param par; |
569 | ||
1da177e4 LT |
570 | if (i && (*i)-- == 0) |
571 | return 1; | |
1da177e4 | 572 | |
6be3d859 JE |
573 | par.match = m->u.match; |
574 | par.matchinfo = m->data; | |
575 | if (par.match->destroy != NULL) | |
576 | par.match->destroy(&par); | |
577 | module_put(par.match->me); | |
1da177e4 LT |
578 | return 0; |
579 | } | |
580 | ||
581 | static inline int | |
582 | ebt_cleanup_watcher(struct ebt_entry_watcher *w, unsigned int *i) | |
583 | { | |
584 | if (i && (*i)-- == 0) | |
585 | return 1; | |
586 | if (w->u.watcher->destroy) | |
043ef46c | 587 | w->u.watcher->destroy(w->u.watcher, w->data); |
1da177e4 LT |
588 | module_put(w->u.watcher->me); |
589 | ||
590 | return 0; | |
591 | } | |
592 | ||
593 | static inline int | |
594 | ebt_cleanup_entry(struct ebt_entry *e, unsigned int *cnt) | |
595 | { | |
596 | struct ebt_entry_target *t; | |
597 | ||
40642f95 | 598 | if (e->bitmask == 0) |
1da177e4 LT |
599 | return 0; |
600 | /* we're done */ | |
601 | if (cnt && (*cnt)-- == 0) | |
602 | return 1; | |
603 | EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, NULL); | |
604 | EBT_MATCH_ITERATE(e, ebt_cleanup_match, NULL); | |
605 | t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); | |
606 | if (t->u.target->destroy) | |
043ef46c | 607 | t->u.target->destroy(t->u.target, t->data); |
1da177e4 LT |
608 | module_put(t->u.target->me); |
609 | ||
610 | return 0; | |
611 | } | |
612 | ||
613 | static inline int | |
614 | ebt_check_entry(struct ebt_entry *e, struct ebt_table_info *newinfo, | |
f7da79d9 | 615 | const char *name, unsigned int *cnt, |
1da177e4 LT |
616 | struct ebt_cl_stack *cl_s, unsigned int udc_cnt) |
617 | { | |
618 | struct ebt_entry_target *t; | |
043ef46c | 619 | struct xt_target *target; |
1da177e4 | 620 | unsigned int i, j, hook = 0, hookmask = 0; |
44f9a2fd | 621 | size_t gap; |
1da177e4 | 622 | int ret; |
6be3d859 | 623 | struct xt_mtchk_param mtpar; |
af5d6dc2 | 624 | struct xt_tgchk_param tgpar; |
1da177e4 LT |
625 | |
626 | /* don't mess with the struct ebt_entries */ | |
40642f95 | 627 | if (e->bitmask == 0) |
1da177e4 LT |
628 | return 0; |
629 | ||
630 | if (e->bitmask & ~EBT_F_MASK) { | |
631 | BUGPRINT("Unknown flag for bitmask\n"); | |
632 | return -EINVAL; | |
633 | } | |
634 | if (e->invflags & ~EBT_INV_MASK) { | |
635 | BUGPRINT("Unknown flag for inv bitmask\n"); | |
636 | return -EINVAL; | |
637 | } | |
638 | if ( (e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3) ) { | |
639 | BUGPRINT("NOPROTO & 802_3 not allowed\n"); | |
640 | return -EINVAL; | |
641 | } | |
642 | /* what hook do we belong to? */ | |
643 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
f7da79d9 | 644 | if (!newinfo->hook_entry[i]) |
1da177e4 LT |
645 | continue; |
646 | if ((char *)newinfo->hook_entry[i] < (char *)e) | |
647 | hook = i; | |
648 | else | |
649 | break; | |
650 | } | |
651 | /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on | |
652 | a base chain */ | |
653 | if (i < NF_BR_NUMHOOKS) | |
654 | hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS); | |
655 | else { | |
656 | for (i = 0; i < udc_cnt; i++) | |
657 | if ((char *)(cl_s[i].cs.chaininfo) > (char *)e) | |
658 | break; | |
659 | if (i == 0) | |
660 | hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS); | |
661 | else | |
662 | hookmask = cl_s[i - 1].hookmask; | |
663 | } | |
664 | i = 0; | |
9b4fce7a | 665 | |
af5d6dc2 JE |
666 | mtpar.table = tgpar.table = name; |
667 | mtpar.entryinfo = tgpar.entryinfo = e; | |
668 | mtpar.hook_mask = tgpar.hook_mask = hookmask; | |
6be3d859 | 669 | ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i); |
1da177e4 LT |
670 | if (ret != 0) |
671 | goto cleanup_matches; | |
672 | j = 0; | |
af5d6dc2 | 673 | ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j); |
1da177e4 LT |
674 | if (ret != 0) |
675 | goto cleanup_watchers; | |
676 | t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); | |
44f9a2fd | 677 | gap = e->next_offset - e->target_offset; |
1da177e4 | 678 | |
043ef46c JE |
679 | target = try_then_request_module( |
680 | xt_find_target(NFPROTO_BRIDGE, t->u.name, 0), | |
681 | "ebt_%s", t->u.name); | |
682 | if (IS_ERR(target)) { | |
683 | ret = PTR_ERR(target); | |
001a18d3 | 684 | goto cleanup_watchers; |
043ef46c JE |
685 | } else if (target == NULL) { |
686 | ret = -ENOENT; | |
001a18d3 JE |
687 | goto cleanup_watchers; |
688 | } | |
689 | ||
1da177e4 LT |
690 | t->u.target = target; |
691 | if (t->u.target == &ebt_standard_target) { | |
14197d54 | 692 | if (gap < sizeof(struct ebt_standard_target)) { |
1da177e4 LT |
693 | BUGPRINT("Standard target size too big\n"); |
694 | ret = -EFAULT; | |
695 | goto cleanup_watchers; | |
696 | } | |
697 | if (((struct ebt_standard_target *)t)->verdict < | |
698 | -NUM_STANDARD_TARGETS) { | |
699 | BUGPRINT("Invalid standard target\n"); | |
700 | ret = -EFAULT; | |
701 | goto cleanup_watchers; | |
702 | } | |
18219d3f JE |
703 | } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) { |
704 | module_put(t->u.target->me); | |
705 | ret = -EFAULT; | |
706 | goto cleanup_watchers; | |
043ef46c JE |
707 | } |
708 | ||
af5d6dc2 JE |
709 | tgpar.target = target; |
710 | tgpar.targinfo = t->data; | |
711 | ret = xt_check_target(&tgpar, NFPROTO_BRIDGE, t->target_size, | |
712 | e->ethproto, e->invflags & EBT_IPROTO); | |
043ef46c JE |
713 | if (ret < 0) { |
714 | module_put(target->me); | |
18219d3f | 715 | goto cleanup_watchers; |
1da177e4 LT |
716 | } |
717 | (*cnt)++; | |
718 | return 0; | |
719 | cleanup_watchers: | |
720 | EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, &j); | |
721 | cleanup_matches: | |
722 | EBT_MATCH_ITERATE(e, ebt_cleanup_match, &i); | |
723 | return ret; | |
724 | } | |
725 | ||
726 | /* | |
727 | * checks for loops and sets the hook mask for udc | |
728 | * the hook mask for udc tells us from which base chains the udc can be | |
729 | * accessed. This mask is a parameter to the check() functions of the extensions | |
730 | */ | |
731 | static int check_chainloops(struct ebt_entries *chain, struct ebt_cl_stack *cl_s, | |
732 | unsigned int udc_cnt, unsigned int hooknr, char *base) | |
733 | { | |
734 | int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict; | |
735 | struct ebt_entry *e = (struct ebt_entry *)chain->data; | |
736 | struct ebt_entry_target *t; | |
737 | ||
738 | while (pos < nentries || chain_nr != -1) { | |
739 | /* end of udc, go back one 'recursion' step */ | |
740 | if (pos == nentries) { | |
741 | /* put back values of the time when this chain was called */ | |
742 | e = cl_s[chain_nr].cs.e; | |
743 | if (cl_s[chain_nr].from != -1) | |
744 | nentries = | |
745 | cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries; | |
746 | else | |
747 | nentries = chain->nentries; | |
748 | pos = cl_s[chain_nr].cs.n; | |
749 | /* make sure we won't see a loop that isn't one */ | |
750 | cl_s[chain_nr].cs.n = 0; | |
751 | chain_nr = cl_s[chain_nr].from; | |
752 | if (pos == nentries) | |
753 | continue; | |
754 | } | |
755 | t = (struct ebt_entry_target *) | |
756 | (((char *)e) + e->target_offset); | |
757 | if (strcmp(t->u.name, EBT_STANDARD_TARGET)) | |
758 | goto letscontinue; | |
759 | if (e->target_offset + sizeof(struct ebt_standard_target) > | |
760 | e->next_offset) { | |
761 | BUGPRINT("Standard target size too big\n"); | |
762 | return -1; | |
763 | } | |
764 | verdict = ((struct ebt_standard_target *)t)->verdict; | |
765 | if (verdict >= 0) { /* jump to another chain */ | |
766 | struct ebt_entries *hlp2 = | |
767 | (struct ebt_entries *)(base + verdict); | |
768 | for (i = 0; i < udc_cnt; i++) | |
769 | if (hlp2 == cl_s[i].cs.chaininfo) | |
770 | break; | |
771 | /* bad destination or loop */ | |
772 | if (i == udc_cnt) { | |
773 | BUGPRINT("bad destination\n"); | |
774 | return -1; | |
775 | } | |
776 | if (cl_s[i].cs.n) { | |
777 | BUGPRINT("loop\n"); | |
778 | return -1; | |
779 | } | |
98a0824a AV |
780 | if (cl_s[i].hookmask & (1 << hooknr)) |
781 | goto letscontinue; | |
782 | /* this can't be 0, so the loop test is correct */ | |
1da177e4 LT |
783 | cl_s[i].cs.n = pos + 1; |
784 | pos = 0; | |
785 | cl_s[i].cs.e = ((void *)e + e->next_offset); | |
786 | e = (struct ebt_entry *)(hlp2->data); | |
787 | nentries = hlp2->nentries; | |
788 | cl_s[i].from = chain_nr; | |
789 | chain_nr = i; | |
790 | /* this udc is accessible from the base chain for hooknr */ | |
791 | cl_s[i].hookmask |= (1 << hooknr); | |
792 | continue; | |
793 | } | |
794 | letscontinue: | |
795 | e = (void *)e + e->next_offset; | |
796 | pos++; | |
797 | } | |
798 | return 0; | |
799 | } | |
800 | ||
801 | /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */ | |
1bc2326c | 802 | static int translate_table(char *name, struct ebt_table_info *newinfo) |
1da177e4 LT |
803 | { |
804 | unsigned int i, j, k, udc_cnt; | |
805 | int ret; | |
806 | struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */ | |
807 | ||
808 | i = 0; | |
1f072c96 | 809 | while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i]) |
1da177e4 LT |
810 | i++; |
811 | if (i == NF_BR_NUMHOOKS) { | |
812 | BUGPRINT("No valid hooks specified\n"); | |
813 | return -EINVAL; | |
814 | } | |
1f072c96 | 815 | if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) { |
1da177e4 LT |
816 | BUGPRINT("Chains don't start at beginning\n"); |
817 | return -EINVAL; | |
818 | } | |
819 | /* make sure chains are ordered after each other in same order | |
820 | as their corresponding hooks */ | |
821 | for (j = i + 1; j < NF_BR_NUMHOOKS; j++) { | |
1f072c96 | 822 | if (!newinfo->hook_entry[j]) |
1da177e4 | 823 | continue; |
1f072c96 | 824 | if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) { |
1da177e4 LT |
825 | BUGPRINT("Hook order must be followed\n"); |
826 | return -EINVAL; | |
827 | } | |
828 | i = j; | |
829 | } | |
830 | ||
1da177e4 LT |
831 | /* do some early checkings and initialize some things */ |
832 | i = 0; /* holds the expected nr. of entries for the chain */ | |
833 | j = 0; /* holds the up to now counted entries for the chain */ | |
834 | k = 0; /* holds the total nr. of entries, should equal | |
9d6f229f | 835 | newinfo->nentries afterwards */ |
1da177e4 LT |
836 | udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */ |
837 | ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
0e795531 AV |
838 | ebt_check_entry_size_and_hooks, newinfo, |
839 | &i, &j, &k, &udc_cnt); | |
1da177e4 LT |
840 | |
841 | if (ret != 0) | |
842 | return ret; | |
843 | ||
844 | if (i != j) { | |
845 | BUGPRINT("nentries does not equal the nr of entries in the " | |
9d6f229f | 846 | "(last) chain\n"); |
1da177e4 LT |
847 | return -EINVAL; |
848 | } | |
849 | if (k != newinfo->nentries) { | |
850 | BUGPRINT("Total nentries is wrong\n"); | |
851 | return -EINVAL; | |
852 | } | |
853 | ||
1da177e4 LT |
854 | /* get the location of the udc, put them in an array |
855 | while we're at it, allocate the chainstack */ | |
856 | if (udc_cnt) { | |
857 | /* this will get free'd in do_replace()/ebt_register_table() | |
858 | if an error occurs */ | |
7ad4d2f6 | 859 | newinfo->chainstack = |
53b8a315 | 860 | vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack))); |
1da177e4 LT |
861 | if (!newinfo->chainstack) |
862 | return -ENOMEM; | |
6f912042 | 863 | for_each_possible_cpu(i) { |
1da177e4 | 864 | newinfo->chainstack[i] = |
18bc89aa | 865 | vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0]))); |
1da177e4 LT |
866 | if (!newinfo->chainstack[i]) { |
867 | while (i) | |
868 | vfree(newinfo->chainstack[--i]); | |
869 | vfree(newinfo->chainstack); | |
870 | newinfo->chainstack = NULL; | |
871 | return -ENOMEM; | |
872 | } | |
873 | } | |
874 | ||
18bc89aa | 875 | cl_s = vmalloc(udc_cnt * sizeof(*cl_s)); |
1da177e4 LT |
876 | if (!cl_s) |
877 | return -ENOMEM; | |
878 | i = 0; /* the i'th udc */ | |
879 | EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
177abc34 | 880 | ebt_get_udc_positions, newinfo, &i, cl_s); |
1da177e4 LT |
881 | /* sanity check */ |
882 | if (i != udc_cnt) { | |
883 | BUGPRINT("i != udc_cnt\n"); | |
884 | vfree(cl_s); | |
885 | return -EFAULT; | |
886 | } | |
887 | } | |
888 | ||
889 | /* Check for loops */ | |
890 | for (i = 0; i < NF_BR_NUMHOOKS; i++) | |
1f072c96 | 891 | if (newinfo->hook_entry[i]) |
1da177e4 LT |
892 | if (check_chainloops(newinfo->hook_entry[i], |
893 | cl_s, udc_cnt, i, newinfo->entries)) { | |
68d31872 | 894 | vfree(cl_s); |
1da177e4 LT |
895 | return -EINVAL; |
896 | } | |
897 | ||
96de0e25 | 898 | /* we now know the following (along with E=mc²): |
1da177e4 LT |
899 | - the nr of entries in each chain is right |
900 | - the size of the allocated space is right | |
901 | - all valid hooks have a corresponding chain | |
902 | - there are no loops | |
903 | - wrong data can still be on the level of a single entry | |
904 | - could be there are jumps to places that are not the | |
905 | beginning of a chain. This can only occur in chains that | |
906 | are not accessible from any base chains, so we don't care. */ | |
907 | ||
908 | /* used to know what we need to clean up if something goes wrong */ | |
909 | i = 0; | |
910 | ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
1bc2326c | 911 | ebt_check_entry, newinfo, name, &i, cl_s, udc_cnt); |
1da177e4 LT |
912 | if (ret != 0) { |
913 | EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
914 | ebt_cleanup_entry, &i); | |
915 | } | |
68d31872 | 916 | vfree(cl_s); |
1da177e4 LT |
917 | return ret; |
918 | } | |
919 | ||
920 | /* called under write_lock */ | |
921 | static void get_counters(struct ebt_counter *oldcounters, | |
922 | struct ebt_counter *counters, unsigned int nentries) | |
923 | { | |
924 | int i, cpu; | |
925 | struct ebt_counter *counter_base; | |
926 | ||
927 | /* counters of cpu 0 */ | |
928 | memcpy(counters, oldcounters, | |
c8923c6b DM |
929 | sizeof(struct ebt_counter) * nentries); |
930 | ||
1da177e4 | 931 | /* add other counters to those of cpu 0 */ |
6f912042 | 932 | for_each_possible_cpu(cpu) { |
c8923c6b DM |
933 | if (cpu == 0) |
934 | continue; | |
1da177e4 LT |
935 | counter_base = COUNTER_BASE(oldcounters, nentries, cpu); |
936 | for (i = 0; i < nentries; i++) { | |
937 | counters[i].pcnt += counter_base[i].pcnt; | |
938 | counters[i].bcnt += counter_base[i].bcnt; | |
939 | } | |
940 | } | |
941 | } | |
942 | ||
943 | /* replace the table */ | |
944 | static int do_replace(void __user *user, unsigned int len) | |
945 | { | |
946 | int ret, i, countersize; | |
947 | struct ebt_table_info *newinfo; | |
948 | struct ebt_replace tmp; | |
949 | struct ebt_table *t; | |
950 | struct ebt_counter *counterstmp = NULL; | |
951 | /* used to be able to unlock earlier */ | |
952 | struct ebt_table_info *table; | |
953 | ||
954 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) | |
955 | return -EFAULT; | |
956 | ||
957 | if (len != sizeof(tmp) + tmp.entries_size) { | |
958 | BUGPRINT("Wrong len argument\n"); | |
959 | return -EINVAL; | |
960 | } | |
961 | ||
962 | if (tmp.entries_size == 0) { | |
963 | BUGPRINT("Entries_size never zero\n"); | |
964 | return -EINVAL; | |
965 | } | |
ee4bb818 KK |
966 | /* overflow check */ |
967 | if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) / NR_CPUS - | |
968 | SMP_CACHE_BYTES) / sizeof(struct ebt_counter)) | |
969 | return -ENOMEM; | |
970 | if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) | |
971 | return -ENOMEM; | |
972 | ||
53b8a315 | 973 | countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids; |
18bc89aa | 974 | newinfo = vmalloc(sizeof(*newinfo) + countersize); |
1da177e4 LT |
975 | if (!newinfo) |
976 | return -ENOMEM; | |
977 | ||
978 | if (countersize) | |
979 | memset(newinfo->counters, 0, countersize); | |
980 | ||
8b3a7005 | 981 | newinfo->entries = vmalloc(tmp.entries_size); |
1da177e4 LT |
982 | if (!newinfo->entries) { |
983 | ret = -ENOMEM; | |
984 | goto free_newinfo; | |
985 | } | |
986 | if (copy_from_user( | |
987 | newinfo->entries, tmp.entries, tmp.entries_size) != 0) { | |
988 | BUGPRINT("Couldn't copy entries from userspace\n"); | |
989 | ret = -EFAULT; | |
990 | goto free_entries; | |
991 | } | |
992 | ||
993 | /* the user wants counters back | |
994 | the check on the size is done later, when we have the lock */ | |
995 | if (tmp.num_counters) { | |
18bc89aa | 996 | counterstmp = vmalloc(tmp.num_counters * sizeof(*counterstmp)); |
1da177e4 LT |
997 | if (!counterstmp) { |
998 | ret = -ENOMEM; | |
999 | goto free_entries; | |
1000 | } | |
1001 | } | |
1002 | else | |
1003 | counterstmp = NULL; | |
1004 | ||
1005 | /* this can get initialized by translate_table() */ | |
1006 | newinfo->chainstack = NULL; | |
1bc2326c AV |
1007 | ret = ebt_verify_pointers(&tmp, newinfo); |
1008 | if (ret != 0) | |
1009 | goto free_counterstmp; | |
1010 | ||
1011 | ret = translate_table(tmp.name, newinfo); | |
1da177e4 LT |
1012 | |
1013 | if (ret != 0) | |
1014 | goto free_counterstmp; | |
1015 | ||
1016 | t = find_table_lock(tmp.name, &ret, &ebt_mutex); | |
1017 | if (!t) { | |
1018 | ret = -ENOENT; | |
1019 | goto free_iterate; | |
1020 | } | |
1021 | ||
1022 | /* the table doesn't like it */ | |
1023 | if (t->check && (ret = t->check(newinfo, tmp.valid_hooks))) | |
1024 | goto free_unlock; | |
1025 | ||
1026 | if (tmp.num_counters && tmp.num_counters != t->private->nentries) { | |
1027 | BUGPRINT("Wrong nr. of counters requested\n"); | |
1028 | ret = -EINVAL; | |
1029 | goto free_unlock; | |
1030 | } | |
1031 | ||
1032 | /* we have the mutex lock, so no danger in reading this pointer */ | |
1033 | table = t->private; | |
1034 | /* make sure the table can only be rmmod'ed if it contains no rules */ | |
1035 | if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) { | |
1036 | ret = -ENOENT; | |
1037 | goto free_unlock; | |
1038 | } else if (table->nentries && !newinfo->nentries) | |
1039 | module_put(t->me); | |
1040 | /* we need an atomic snapshot of the counters */ | |
1041 | write_lock_bh(&t->lock); | |
1042 | if (tmp.num_counters) | |
1043 | get_counters(t->private->counters, counterstmp, | |
1044 | t->private->nentries); | |
1045 | ||
1046 | t->private = newinfo; | |
1047 | write_unlock_bh(&t->lock); | |
57b47a53 | 1048 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1049 | /* so, a user can change the chains while having messed up her counter |
1050 | allocation. Only reason why this is done is because this way the lock | |
1051 | is held only once, while this doesn't bring the kernel into a | |
1052 | dangerous state. */ | |
1053 | if (tmp.num_counters && | |
1054 | copy_to_user(tmp.counters, counterstmp, | |
1055 | tmp.num_counters * sizeof(struct ebt_counter))) { | |
1056 | BUGPRINT("Couldn't copy counters to userspace\n"); | |
1057 | ret = -EFAULT; | |
1058 | } | |
1059 | else | |
1060 | ret = 0; | |
1061 | ||
1062 | /* decrease module count and free resources */ | |
1063 | EBT_ENTRY_ITERATE(table->entries, table->entries_size, | |
1064 | ebt_cleanup_entry, NULL); | |
1065 | ||
1066 | vfree(table->entries); | |
1067 | if (table->chainstack) { | |
6f912042 | 1068 | for_each_possible_cpu(i) |
1da177e4 LT |
1069 | vfree(table->chainstack[i]); |
1070 | vfree(table->chainstack); | |
1071 | } | |
1072 | vfree(table); | |
1073 | ||
68d31872 | 1074 | vfree(counterstmp); |
1da177e4 LT |
1075 | return ret; |
1076 | ||
1077 | free_unlock: | |
57b47a53 | 1078 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1079 | free_iterate: |
1080 | EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
1081 | ebt_cleanup_entry, NULL); | |
1082 | free_counterstmp: | |
68d31872 | 1083 | vfree(counterstmp); |
1da177e4 LT |
1084 | /* can be initialized in translate_table() */ |
1085 | if (newinfo->chainstack) { | |
6f912042 | 1086 | for_each_possible_cpu(i) |
1da177e4 LT |
1087 | vfree(newinfo->chainstack[i]); |
1088 | vfree(newinfo->chainstack); | |
1089 | } | |
1090 | free_entries: | |
68d31872 | 1091 | vfree(newinfo->entries); |
1da177e4 | 1092 | free_newinfo: |
68d31872 | 1093 | vfree(newinfo); |
1da177e4 LT |
1094 | return ret; |
1095 | } | |
1096 | ||
1da177e4 LT |
1097 | int ebt_register_table(struct ebt_table *table) |
1098 | { | |
1099 | struct ebt_table_info *newinfo; | |
df0933dc | 1100 | struct ebt_table *t; |
1e419cd9 | 1101 | struct ebt_replace_kernel *repl; |
1da177e4 | 1102 | int ret, i, countersize; |
df07a81e | 1103 | void *p; |
1da177e4 | 1104 | |
df07a81e AV |
1105 | if (!table || !(repl = table->table) || !repl->entries || |
1106 | repl->entries_size == 0 || | |
1107 | repl->counters || table->private) { | |
1da177e4 LT |
1108 | BUGPRINT("Bad table data for ebt_register_table!!!\n"); |
1109 | return -EINVAL; | |
1110 | } | |
1111 | ||
53b8a315 | 1112 | countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids; |
18bc89aa | 1113 | newinfo = vmalloc(sizeof(*newinfo) + countersize); |
1da177e4 LT |
1114 | ret = -ENOMEM; |
1115 | if (!newinfo) | |
1116 | return -ENOMEM; | |
1117 | ||
df07a81e AV |
1118 | p = vmalloc(repl->entries_size); |
1119 | if (!p) | |
1da177e4 LT |
1120 | goto free_newinfo; |
1121 | ||
df07a81e AV |
1122 | memcpy(p, repl->entries, repl->entries_size); |
1123 | newinfo->entries = p; | |
1124 | ||
1125 | newinfo->entries_size = repl->entries_size; | |
1126 | newinfo->nentries = repl->nentries; | |
1da177e4 LT |
1127 | |
1128 | if (countersize) | |
1129 | memset(newinfo->counters, 0, countersize); | |
1130 | ||
1131 | /* fill in newinfo and parse the entries */ | |
1132 | newinfo->chainstack = NULL; | |
df07a81e AV |
1133 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { |
1134 | if ((repl->valid_hooks & (1 << i)) == 0) | |
1135 | newinfo->hook_entry[i] = NULL; | |
1136 | else | |
1137 | newinfo->hook_entry[i] = p + | |
1138 | ((char *)repl->hook_entry[i] - repl->entries); | |
1139 | } | |
1140 | ret = translate_table(repl->name, newinfo); | |
1da177e4 LT |
1141 | if (ret != 0) { |
1142 | BUGPRINT("Translate_table failed\n"); | |
1143 | goto free_chainstack; | |
1144 | } | |
1145 | ||
1146 | if (table->check && table->check(newinfo, table->valid_hooks)) { | |
1147 | BUGPRINT("The table doesn't like its own initial data, lol\n"); | |
1148 | return -EINVAL; | |
1149 | } | |
1150 | ||
1151 | table->private = newinfo; | |
1152 | rwlock_init(&table->lock); | |
57b47a53 | 1153 | ret = mutex_lock_interruptible(&ebt_mutex); |
1da177e4 LT |
1154 | if (ret != 0) |
1155 | goto free_chainstack; | |
1156 | ||
df0933dc PM |
1157 | list_for_each_entry(t, &ebt_tables, list) { |
1158 | if (strcmp(t->name, table->name) == 0) { | |
1159 | ret = -EEXIST; | |
1160 | BUGPRINT("Table name already exists\n"); | |
1161 | goto free_unlock; | |
1162 | } | |
1da177e4 LT |
1163 | } |
1164 | ||
1165 | /* Hold a reference count if the chains aren't empty */ | |
1166 | if (newinfo->nentries && !try_module_get(table->me)) { | |
1167 | ret = -ENOENT; | |
1168 | goto free_unlock; | |
1169 | } | |
df0933dc | 1170 | list_add(&table->list, &ebt_tables); |
57b47a53 | 1171 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1172 | return 0; |
1173 | free_unlock: | |
57b47a53 | 1174 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1175 | free_chainstack: |
1176 | if (newinfo->chainstack) { | |
6f912042 | 1177 | for_each_possible_cpu(i) |
1da177e4 LT |
1178 | vfree(newinfo->chainstack[i]); |
1179 | vfree(newinfo->chainstack); | |
1180 | } | |
1181 | vfree(newinfo->entries); | |
1182 | free_newinfo: | |
1183 | vfree(newinfo); | |
1184 | return ret; | |
1185 | } | |
1186 | ||
1187 | void ebt_unregister_table(struct ebt_table *table) | |
1188 | { | |
1189 | int i; | |
1190 | ||
1191 | if (!table) { | |
1192 | BUGPRINT("Request to unregister NULL table!!!\n"); | |
1193 | return; | |
1194 | } | |
57b47a53 | 1195 | mutex_lock(&ebt_mutex); |
df0933dc | 1196 | list_del(&table->list); |
57b47a53 | 1197 | mutex_unlock(&ebt_mutex); |
68d31872 | 1198 | vfree(table->private->entries); |
1da177e4 | 1199 | if (table->private->chainstack) { |
6f912042 | 1200 | for_each_possible_cpu(i) |
1da177e4 LT |
1201 | vfree(table->private->chainstack[i]); |
1202 | vfree(table->private->chainstack); | |
1203 | } | |
1204 | vfree(table->private); | |
1205 | } | |
1206 | ||
1207 | /* userspace just supplied us with counters */ | |
1208 | static int update_counters(void __user *user, unsigned int len) | |
1209 | { | |
1210 | int i, ret; | |
1211 | struct ebt_counter *tmp; | |
1212 | struct ebt_replace hlp; | |
1213 | struct ebt_table *t; | |
1214 | ||
1215 | if (copy_from_user(&hlp, user, sizeof(hlp))) | |
1216 | return -EFAULT; | |
1217 | ||
1218 | if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter)) | |
1219 | return -EINVAL; | |
1220 | if (hlp.num_counters == 0) | |
1221 | return -EINVAL; | |
1222 | ||
18bc89aa | 1223 | if (!(tmp = vmalloc(hlp.num_counters * sizeof(*tmp)))) { |
1da177e4 LT |
1224 | MEMPRINT("Update_counters && nomemory\n"); |
1225 | return -ENOMEM; | |
1226 | } | |
1227 | ||
1228 | t = find_table_lock(hlp.name, &ret, &ebt_mutex); | |
1229 | if (!t) | |
1230 | goto free_tmp; | |
1231 | ||
1232 | if (hlp.num_counters != t->private->nentries) { | |
1233 | BUGPRINT("Wrong nr of counters\n"); | |
1234 | ret = -EINVAL; | |
1235 | goto unlock_mutex; | |
1236 | } | |
1237 | ||
1238 | if ( copy_from_user(tmp, hlp.counters, | |
1239 | hlp.num_counters * sizeof(struct ebt_counter)) ) { | |
1240 | BUGPRINT("Updata_counters && !cfu\n"); | |
1241 | ret = -EFAULT; | |
1242 | goto unlock_mutex; | |
1243 | } | |
1244 | ||
1245 | /* we want an atomic add of the counters */ | |
1246 | write_lock_bh(&t->lock); | |
1247 | ||
1248 | /* we add to the counters of the first cpu */ | |
1249 | for (i = 0; i < hlp.num_counters; i++) { | |
1250 | t->private->counters[i].pcnt += tmp[i].pcnt; | |
1251 | t->private->counters[i].bcnt += tmp[i].bcnt; | |
1252 | } | |
1253 | ||
1254 | write_unlock_bh(&t->lock); | |
1255 | ret = 0; | |
1256 | unlock_mutex: | |
57b47a53 | 1257 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1258 | free_tmp: |
1259 | vfree(tmp); | |
1260 | return ret; | |
1261 | } | |
1262 | ||
1263 | static inline int ebt_make_matchname(struct ebt_entry_match *m, | |
1e419cd9 | 1264 | char *base, char __user *ubase) |
1da177e4 | 1265 | { |
1e419cd9 | 1266 | char __user *hlp = ubase + ((char *)m - base); |
1da177e4 LT |
1267 | if (copy_to_user(hlp, m->u.match->name, EBT_FUNCTION_MAXNAMELEN)) |
1268 | return -EFAULT; | |
1269 | return 0; | |
1270 | } | |
1271 | ||
1272 | static inline int ebt_make_watchername(struct ebt_entry_watcher *w, | |
1e419cd9 | 1273 | char *base, char __user *ubase) |
1da177e4 | 1274 | { |
1e419cd9 | 1275 | char __user *hlp = ubase + ((char *)w - base); |
1da177e4 LT |
1276 | if (copy_to_user(hlp , w->u.watcher->name, EBT_FUNCTION_MAXNAMELEN)) |
1277 | return -EFAULT; | |
1278 | return 0; | |
1279 | } | |
1280 | ||
1e419cd9 | 1281 | static inline int ebt_make_names(struct ebt_entry *e, char *base, char __user *ubase) |
1da177e4 LT |
1282 | { |
1283 | int ret; | |
1e419cd9 | 1284 | char __user *hlp; |
1da177e4 LT |
1285 | struct ebt_entry_target *t; |
1286 | ||
40642f95 | 1287 | if (e->bitmask == 0) |
1da177e4 LT |
1288 | return 0; |
1289 | ||
1e419cd9 | 1290 | hlp = ubase + (((char *)e + e->target_offset) - base); |
1da177e4 | 1291 | t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); |
9d6f229f | 1292 | |
1da177e4 LT |
1293 | ret = EBT_MATCH_ITERATE(e, ebt_make_matchname, base, ubase); |
1294 | if (ret != 0) | |
1295 | return ret; | |
1296 | ret = EBT_WATCHER_ITERATE(e, ebt_make_watchername, base, ubase); | |
1297 | if (ret != 0) | |
1298 | return ret; | |
1299 | if (copy_to_user(hlp, t->u.target->name, EBT_FUNCTION_MAXNAMELEN)) | |
1300 | return -EFAULT; | |
1301 | return 0; | |
1302 | } | |
1303 | ||
57b47a53 | 1304 | /* called with ebt_mutex locked */ |
1da177e4 LT |
1305 | static int copy_everything_to_user(struct ebt_table *t, void __user *user, |
1306 | int *len, int cmd) | |
1307 | { | |
1308 | struct ebt_replace tmp; | |
1309 | struct ebt_counter *counterstmp, *oldcounters; | |
1310 | unsigned int entries_size, nentries; | |
1311 | char *entries; | |
1312 | ||
1313 | if (cmd == EBT_SO_GET_ENTRIES) { | |
1314 | entries_size = t->private->entries_size; | |
1315 | nentries = t->private->nentries; | |
1316 | entries = t->private->entries; | |
1317 | oldcounters = t->private->counters; | |
1318 | } else { | |
1319 | entries_size = t->table->entries_size; | |
1320 | nentries = t->table->nentries; | |
1321 | entries = t->table->entries; | |
1322 | oldcounters = t->table->counters; | |
1323 | } | |
1324 | ||
1325 | if (copy_from_user(&tmp, user, sizeof(tmp))) { | |
1326 | BUGPRINT("Cfu didn't work\n"); | |
1327 | return -EFAULT; | |
1328 | } | |
1329 | ||
1330 | if (*len != sizeof(struct ebt_replace) + entries_size + | |
1331 | (tmp.num_counters? nentries * sizeof(struct ebt_counter): 0)) { | |
1332 | BUGPRINT("Wrong size\n"); | |
1333 | return -EINVAL; | |
1334 | } | |
1335 | ||
1336 | if (tmp.nentries != nentries) { | |
1337 | BUGPRINT("Nentries wrong\n"); | |
1338 | return -EINVAL; | |
1339 | } | |
1340 | ||
1341 | if (tmp.entries_size != entries_size) { | |
1342 | BUGPRINT("Wrong size\n"); | |
1343 | return -EINVAL; | |
1344 | } | |
1345 | ||
1346 | /* userspace might not need the counters */ | |
1347 | if (tmp.num_counters) { | |
1348 | if (tmp.num_counters != nentries) { | |
1349 | BUGPRINT("Num_counters wrong\n"); | |
1350 | return -EINVAL; | |
1351 | } | |
18bc89aa | 1352 | counterstmp = vmalloc(nentries * sizeof(*counterstmp)); |
1da177e4 LT |
1353 | if (!counterstmp) { |
1354 | MEMPRINT("Couldn't copy counters, out of memory\n"); | |
1355 | return -ENOMEM; | |
1356 | } | |
1357 | write_lock_bh(&t->lock); | |
1358 | get_counters(oldcounters, counterstmp, nentries); | |
1359 | write_unlock_bh(&t->lock); | |
1360 | ||
1361 | if (copy_to_user(tmp.counters, counterstmp, | |
1362 | nentries * sizeof(struct ebt_counter))) { | |
1363 | BUGPRINT("Couldn't copy counters to userspace\n"); | |
1364 | vfree(counterstmp); | |
1365 | return -EFAULT; | |
1366 | } | |
1367 | vfree(counterstmp); | |
1368 | } | |
1369 | ||
1370 | if (copy_to_user(tmp.entries, entries, entries_size)) { | |
1371 | BUGPRINT("Couldn't copy entries to userspace\n"); | |
1372 | return -EFAULT; | |
1373 | } | |
1374 | /* set the match/watcher/target names right */ | |
1375 | return EBT_ENTRY_ITERATE(entries, entries_size, | |
1376 | ebt_make_names, entries, tmp.entries); | |
1377 | } | |
1378 | ||
1379 | static int do_ebt_set_ctl(struct sock *sk, | |
1380 | int cmd, void __user *user, unsigned int len) | |
1381 | { | |
1382 | int ret; | |
1383 | ||
1384 | switch(cmd) { | |
1385 | case EBT_SO_SET_ENTRIES: | |
1386 | ret = do_replace(user, len); | |
1387 | break; | |
1388 | case EBT_SO_SET_COUNTERS: | |
1389 | ret = update_counters(user, len); | |
1390 | break; | |
1391 | default: | |
1392 | ret = -EINVAL; | |
1393 | } | |
1394 | return ret; | |
1395 | } | |
1396 | ||
1397 | static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) | |
1398 | { | |
1399 | int ret; | |
1400 | struct ebt_replace tmp; | |
1401 | struct ebt_table *t; | |
1402 | ||
1403 | if (copy_from_user(&tmp, user, sizeof(tmp))) | |
1404 | return -EFAULT; | |
1405 | ||
1406 | t = find_table_lock(tmp.name, &ret, &ebt_mutex); | |
1407 | if (!t) | |
1408 | return ret; | |
1409 | ||
1410 | switch(cmd) { | |
1411 | case EBT_SO_GET_INFO: | |
1412 | case EBT_SO_GET_INIT_INFO: | |
1413 | if (*len != sizeof(struct ebt_replace)){ | |
1414 | ret = -EINVAL; | |
57b47a53 | 1415 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1416 | break; |
1417 | } | |
1418 | if (cmd == EBT_SO_GET_INFO) { | |
1419 | tmp.nentries = t->private->nentries; | |
1420 | tmp.entries_size = t->private->entries_size; | |
1421 | tmp.valid_hooks = t->valid_hooks; | |
1422 | } else { | |
1423 | tmp.nentries = t->table->nentries; | |
1424 | tmp.entries_size = t->table->entries_size; | |
1425 | tmp.valid_hooks = t->table->valid_hooks; | |
1426 | } | |
57b47a53 | 1427 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1428 | if (copy_to_user(user, &tmp, *len) != 0){ |
1429 | BUGPRINT("c2u Didn't work\n"); | |
1430 | ret = -EFAULT; | |
1431 | break; | |
1432 | } | |
1433 | ret = 0; | |
1434 | break; | |
1435 | ||
1436 | case EBT_SO_GET_ENTRIES: | |
1437 | case EBT_SO_GET_INIT_ENTRIES: | |
1438 | ret = copy_everything_to_user(t, user, len, cmd); | |
57b47a53 | 1439 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1440 | break; |
1441 | ||
1442 | default: | |
57b47a53 | 1443 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1444 | ret = -EINVAL; |
1445 | } | |
1446 | ||
1447 | return ret; | |
1448 | } | |
1449 | ||
1450 | static struct nf_sockopt_ops ebt_sockopts = | |
74ca4e5a AM |
1451 | { |
1452 | .pf = PF_INET, | |
1453 | .set_optmin = EBT_BASE_CTL, | |
1454 | .set_optmax = EBT_SO_SET_MAX + 1, | |
1455 | .set = do_ebt_set_ctl, | |
1456 | .get_optmin = EBT_BASE_CTL, | |
1457 | .get_optmax = EBT_SO_GET_MAX + 1, | |
1458 | .get = do_ebt_get_ctl, | |
16fcec35 | 1459 | .owner = THIS_MODULE, |
1da177e4 LT |
1460 | }; |
1461 | ||
65b4b4e8 | 1462 | static int __init ebtables_init(void) |
1da177e4 LT |
1463 | { |
1464 | int ret; | |
1465 | ||
043ef46c JE |
1466 | ret = xt_register_target(&ebt_standard_target); |
1467 | if (ret < 0) | |
1da177e4 | 1468 | return ret; |
043ef46c JE |
1469 | ret = nf_register_sockopt(&ebt_sockopts); |
1470 | if (ret < 0) { | |
1471 | xt_unregister_target(&ebt_standard_target); | |
1472 | return ret; | |
1473 | } | |
1da177e4 | 1474 | |
a887c1c1 | 1475 | printk(KERN_INFO "Ebtables v2.0 registered\n"); |
1da177e4 LT |
1476 | return 0; |
1477 | } | |
1478 | ||
65b4b4e8 | 1479 | static void __exit ebtables_fini(void) |
1da177e4 LT |
1480 | { |
1481 | nf_unregister_sockopt(&ebt_sockopts); | |
043ef46c | 1482 | xt_unregister_target(&ebt_standard_target); |
a887c1c1 | 1483 | printk(KERN_INFO "Ebtables v2.0 unregistered\n"); |
1da177e4 LT |
1484 | } |
1485 | ||
1486 | EXPORT_SYMBOL(ebt_register_table); | |
1487 | EXPORT_SYMBOL(ebt_unregister_table); | |
1da177e4 | 1488 | EXPORT_SYMBOL(ebt_do_table); |
65b4b4e8 AM |
1489 | module_init(ebtables_init); |
1490 | module_exit(ebtables_fini); | |
1da177e4 | 1491 | MODULE_LICENSE("GPL"); |