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 | |
043ef46c | 59 | static struct xt_target ebt_standard_target = { |
001a18d3 JE |
60 | .name = "standard", |
61 | .revision = 0, | |
62 | .family = NFPROTO_BRIDGE, | |
043ef46c | 63 | .targetsize = sizeof(int), |
18219d3f | 64 | }; |
1da177e4 | 65 | |
7eb35586 JE |
66 | static inline int |
67 | ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb, | |
68 | struct xt_target_param *par) | |
1da177e4 | 69 | { |
7eb35586 JE |
70 | par->target = w->u.watcher; |
71 | par->targinfo = w->data; | |
72 | w->u.watcher->target(skb, par); | |
1da177e4 LT |
73 | /* watchers don't give a verdict */ |
74 | return 0; | |
75 | } | |
76 | ||
77 | static inline int ebt_do_match (struct ebt_entry_match *m, | |
f7108a20 | 78 | const struct sk_buff *skb, struct xt_match_param *par) |
1da177e4 | 79 | { |
f7108a20 JE |
80 | par->match = m->u.match; |
81 | par->matchinfo = m->data; | |
82 | return m->u.match->match(skb, par); | |
1da177e4 LT |
83 | } |
84 | ||
85 | static inline int ebt_dev_check(char *entry, const struct net_device *device) | |
86 | { | |
87 | int i = 0; | |
f3d8b2e4 | 88 | const char *devname; |
1da177e4 LT |
89 | |
90 | if (*entry == '\0') | |
91 | return 0; | |
92 | if (!device) | |
93 | return 1; | |
f3d8b2e4 | 94 | devname = device->name; |
1da177e4 LT |
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 | |
916a917d | 163 | mtpar.family = tgpar.family = NFPROTO_BRIDGE; |
7eb35586 JE |
164 | mtpar.in = tgpar.in = in; |
165 | mtpar.out = tgpar.out = out; | |
f7108a20 | 166 | mtpar.hotdrop = &hotdrop; |
7eb35586 | 167 | tgpar.hooknum = hook; |
1da177e4 LT |
168 | |
169 | read_lock_bh(&table->lock); | |
170 | private = table->private; | |
171 | cb_base = COUNTER_BASE(private->counters, private->nentries, | |
172 | smp_processor_id()); | |
173 | if (private->chainstack) | |
174 | cs = private->chainstack[smp_processor_id()]; | |
175 | else | |
176 | cs = NULL; | |
177 | chaininfo = private->hook_entry[hook]; | |
178 | nentries = private->hook_entry[hook]->nentries; | |
179 | point = (struct ebt_entry *)(private->hook_entry[hook]->data); | |
180 | counter_base = cb_base + private->hook_entry[hook]->counter_offset; | |
181 | /* base for chain jumps */ | |
182 | base = private->entries; | |
183 | i = 0; | |
184 | while (i < nentries) { | |
3db05fea | 185 | if (ebt_basic_match(point, eth_hdr(skb), in, out)) |
1da177e4 LT |
186 | goto letscontinue; |
187 | ||
f7108a20 | 188 | if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &mtpar) != 0) |
1da177e4 | 189 | goto letscontinue; |
5365f802 JE |
190 | if (hotdrop) { |
191 | read_unlock_bh(&table->lock); | |
192 | return NF_DROP; | |
193 | } | |
1da177e4 LT |
194 | |
195 | /* increase counter */ | |
196 | (*(counter_base + i)).pcnt++; | |
3db05fea | 197 | (*(counter_base + i)).bcnt += skb->len; |
1da177e4 LT |
198 | |
199 | /* these should only watch: not modify, nor tell us | |
200 | what to do with the packet */ | |
7eb35586 | 201 | EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &tgpar); |
1da177e4 LT |
202 | |
203 | t = (struct ebt_entry_target *) | |
204 | (((char *)point) + point->target_offset); | |
205 | /* standard target */ | |
206 | if (!t->u.target->target) | |
207 | verdict = ((struct ebt_standard_target *)t)->verdict; | |
7eb35586 JE |
208 | else { |
209 | tgpar.target = t->u.target; | |
210 | tgpar.targinfo = t->data; | |
211 | verdict = t->u.target->target(skb, &tgpar); | |
212 | } | |
1da177e4 LT |
213 | if (verdict == EBT_ACCEPT) { |
214 | read_unlock_bh(&table->lock); | |
215 | return NF_ACCEPT; | |
216 | } | |
217 | if (verdict == EBT_DROP) { | |
218 | read_unlock_bh(&table->lock); | |
219 | return NF_DROP; | |
220 | } | |
221 | if (verdict == EBT_RETURN) { | |
222 | letsreturn: | |
223 | #ifdef CONFIG_NETFILTER_DEBUG | |
224 | if (sp == 0) { | |
225 | BUGPRINT("RETURN on base chain"); | |
226 | /* act like this is EBT_CONTINUE */ | |
227 | goto letscontinue; | |
228 | } | |
229 | #endif | |
230 | sp--; | |
231 | /* put all the local variables right */ | |
232 | i = cs[sp].n; | |
233 | chaininfo = cs[sp].chaininfo; | |
234 | nentries = chaininfo->nentries; | |
235 | point = cs[sp].e; | |
236 | counter_base = cb_base + | |
237 | chaininfo->counter_offset; | |
238 | continue; | |
239 | } | |
240 | if (verdict == EBT_CONTINUE) | |
241 | goto letscontinue; | |
242 | #ifdef CONFIG_NETFILTER_DEBUG | |
243 | if (verdict < 0) { | |
244 | BUGPRINT("bogus standard verdict\n"); | |
245 | read_unlock_bh(&table->lock); | |
246 | return NF_DROP; | |
247 | } | |
248 | #endif | |
249 | /* jump to a udc */ | |
250 | cs[sp].n = i + 1; | |
251 | cs[sp].chaininfo = chaininfo; | |
252 | cs[sp].e = (struct ebt_entry *) | |
253 | (((char *)point) + point->next_offset); | |
254 | i = 0; | |
255 | chaininfo = (struct ebt_entries *) (base + verdict); | |
256 | #ifdef CONFIG_NETFILTER_DEBUG | |
257 | if (chaininfo->distinguisher) { | |
258 | BUGPRINT("jump to non-chain\n"); | |
259 | read_unlock_bh(&table->lock); | |
260 | return NF_DROP; | |
261 | } | |
262 | #endif | |
263 | nentries = chaininfo->nentries; | |
264 | point = (struct ebt_entry *)chaininfo->data; | |
265 | counter_base = cb_base + chaininfo->counter_offset; | |
266 | sp++; | |
267 | continue; | |
268 | letscontinue: | |
269 | point = (struct ebt_entry *) | |
270 | (((char *)point) + point->next_offset); | |
271 | i++; | |
272 | } | |
273 | ||
274 | /* I actually like this :) */ | |
275 | if (chaininfo->policy == EBT_RETURN) | |
276 | goto letsreturn; | |
277 | if (chaininfo->policy == EBT_ACCEPT) { | |
278 | read_unlock_bh(&table->lock); | |
279 | return NF_ACCEPT; | |
280 | } | |
281 | read_unlock_bh(&table->lock); | |
282 | return NF_DROP; | |
283 | } | |
284 | ||
285 | /* If it succeeds, returns element and locks mutex */ | |
286 | static inline void * | |
287 | find_inlist_lock_noload(struct list_head *head, const char *name, int *error, | |
57b47a53 | 288 | struct mutex *mutex) |
1da177e4 | 289 | { |
df0933dc PM |
290 | struct { |
291 | struct list_head list; | |
292 | char name[EBT_FUNCTION_MAXNAMELEN]; | |
293 | } *e; | |
1da177e4 | 294 | |
57b47a53 | 295 | *error = mutex_lock_interruptible(mutex); |
1da177e4 LT |
296 | if (*error != 0) |
297 | return NULL; | |
298 | ||
df0933dc PM |
299 | list_for_each_entry(e, head, list) { |
300 | if (strcmp(e->name, name) == 0) | |
301 | return e; | |
1da177e4 | 302 | } |
df0933dc PM |
303 | *error = -ENOENT; |
304 | mutex_unlock(mutex); | |
305 | return NULL; | |
1da177e4 LT |
306 | } |
307 | ||
1da177e4 LT |
308 | static void * |
309 | find_inlist_lock(struct list_head *head, const char *name, const char *prefix, | |
57b47a53 | 310 | int *error, struct mutex *mutex) |
1da177e4 | 311 | { |
95a5afca JB |
312 | return try_then_request_module( |
313 | find_inlist_lock_noload(head, name, error, mutex), | |
314 | "%s%s", prefix, name); | |
1da177e4 | 315 | } |
1da177e4 LT |
316 | |
317 | static inline struct ebt_table * | |
511061e2 AD |
318 | find_table_lock(struct net *net, const char *name, int *error, |
319 | struct mutex *mutex) | |
1da177e4 | 320 | { |
511061e2 AD |
321 | return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name, |
322 | "ebtable_", error, mutex); | |
1da177e4 LT |
323 | } |
324 | ||
1da177e4 | 325 | static inline int |
9b4fce7a JE |
326 | ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par, |
327 | unsigned int *cnt) | |
1da177e4 | 328 | { |
9b4fce7a | 329 | const struct ebt_entry *e = par->entryinfo; |
043ef46c | 330 | struct xt_match *match; |
14197d54 | 331 | size_t left = ((char *)e + e->watchers_offset) - (char *)m; |
1da177e4 LT |
332 | int ret; |
333 | ||
14197d54 AV |
334 | if (left < sizeof(struct ebt_entry_match) || |
335 | left - sizeof(struct ebt_entry_match) < m->match_size) | |
1da177e4 | 336 | return -EINVAL; |
043ef46c JE |
337 | |
338 | match = try_then_request_module(xt_find_match(NFPROTO_BRIDGE, | |
339 | m->u.name, 0), "ebt_%s", m->u.name); | |
340 | if (IS_ERR(match)) | |
341 | return PTR_ERR(match); | |
342 | if (match == NULL) | |
1da177e4 | 343 | return -ENOENT; |
043ef46c JE |
344 | m->u.match = match; |
345 | ||
9b4fce7a JE |
346 | par->match = match; |
347 | par->matchinfo = m->data; | |
916a917d | 348 | ret = xt_check_match(par, m->match_size, |
9b4fce7a | 349 | e->ethproto, e->invflags & EBT_IPROTO); |
043ef46c JE |
350 | if (ret < 0) { |
351 | module_put(match->me); | |
352 | return ret; | |
1da177e4 | 353 | } |
043ef46c | 354 | |
1da177e4 LT |
355 | (*cnt)++; |
356 | return 0; | |
357 | } | |
358 | ||
359 | static inline int | |
af5d6dc2 JE |
360 | ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par, |
361 | unsigned int *cnt) | |
1da177e4 | 362 | { |
af5d6dc2 | 363 | const struct ebt_entry *e = par->entryinfo; |
043ef46c | 364 | struct xt_target *watcher; |
14197d54 | 365 | size_t left = ((char *)e + e->target_offset) - (char *)w; |
1da177e4 LT |
366 | int ret; |
367 | ||
14197d54 AV |
368 | if (left < sizeof(struct ebt_entry_watcher) || |
369 | left - sizeof(struct ebt_entry_watcher) < w->watcher_size) | |
1da177e4 | 370 | return -EINVAL; |
043ef46c JE |
371 | |
372 | watcher = try_then_request_module( | |
373 | xt_find_target(NFPROTO_BRIDGE, w->u.name, 0), | |
374 | "ebt_%s", w->u.name); | |
375 | if (IS_ERR(watcher)) | |
376 | return PTR_ERR(watcher); | |
377 | if (watcher == NULL) | |
1da177e4 | 378 | return -ENOENT; |
043ef46c JE |
379 | w->u.watcher = watcher; |
380 | ||
af5d6dc2 JE |
381 | par->target = watcher; |
382 | par->targinfo = w->data; | |
916a917d | 383 | ret = xt_check_target(par, w->watcher_size, |
af5d6dc2 | 384 | e->ethproto, e->invflags & EBT_IPROTO); |
043ef46c JE |
385 | if (ret < 0) { |
386 | module_put(watcher->me); | |
387 | return ret; | |
1da177e4 | 388 | } |
043ef46c | 389 | |
1da177e4 LT |
390 | (*cnt)++; |
391 | return 0; | |
392 | } | |
393 | ||
70fe9af4 AV |
394 | static int ebt_verify_pointers(struct ebt_replace *repl, |
395 | struct ebt_table_info *newinfo) | |
1da177e4 | 396 | { |
70fe9af4 AV |
397 | unsigned int limit = repl->entries_size; |
398 | unsigned int valid_hooks = repl->valid_hooks; | |
399 | unsigned int offset = 0; | |
1da177e4 LT |
400 | int i; |
401 | ||
e4fd77de AV |
402 | for (i = 0; i < NF_BR_NUMHOOKS; i++) |
403 | newinfo->hook_entry[i] = NULL; | |
404 | ||
405 | newinfo->entries_size = repl->entries_size; | |
406 | newinfo->nentries = repl->nentries; | |
407 | ||
70fe9af4 AV |
408 | while (offset < limit) { |
409 | size_t left = limit - offset; | |
410 | struct ebt_entry *e = (void *)newinfo->entries + offset; | |
bb2ef25c | 411 | |
70fe9af4 | 412 | if (left < sizeof(unsigned int)) |
1da177e4 | 413 | break; |
70fe9af4 AV |
414 | |
415 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
416 | if ((valid_hooks & (1 << i)) == 0) | |
417 | continue; | |
1e419cd9 AV |
418 | if ((char __user *)repl->hook_entry[i] == |
419 | repl->entries + offset) | |
70fe9af4 AV |
420 | break; |
421 | } | |
422 | ||
423 | if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) { | |
424 | if (e->bitmask != 0) { | |
425 | /* we make userspace set this right, | |
426 | so there is no misunderstanding */ | |
427 | BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set " | |
428 | "in distinguisher\n"); | |
429 | return -EINVAL; | |
430 | } | |
431 | if (i != NF_BR_NUMHOOKS) | |
432 | newinfo->hook_entry[i] = (struct ebt_entries *)e; | |
433 | if (left < sizeof(struct ebt_entries)) | |
434 | break; | |
435 | offset += sizeof(struct ebt_entries); | |
436 | } else { | |
437 | if (left < sizeof(struct ebt_entry)) | |
438 | break; | |
439 | if (left < e->next_offset) | |
440 | break; | |
441 | offset += e->next_offset; | |
1da177e4 | 442 | } |
22b440bf | 443 | } |
70fe9af4 AV |
444 | if (offset != limit) { |
445 | BUGPRINT("entries_size too small\n"); | |
446 | return -EINVAL; | |
447 | } | |
e4fd77de AV |
448 | |
449 | /* check if all valid hooks have a chain */ | |
450 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
451 | if (!newinfo->hook_entry[i] && | |
452 | (valid_hooks & (1 << i))) { | |
453 | BUGPRINT("Valid hook without chain\n"); | |
454 | return -EINVAL; | |
455 | } | |
456 | } | |
22b440bf | 457 | return 0; |
22b440bf AV |
458 | } |
459 | ||
460 | /* | |
461 | * this one is very careful, as it is the first function | |
462 | * to parse the userspace data | |
463 | */ | |
464 | static inline int | |
465 | ebt_check_entry_size_and_hooks(struct ebt_entry *e, | |
0e795531 AV |
466 | struct ebt_table_info *newinfo, |
467 | unsigned int *n, unsigned int *cnt, | |
468 | unsigned int *totalcnt, unsigned int *udc_cnt) | |
22b440bf | 469 | { |
22b440bf AV |
470 | int i; |
471 | ||
472 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
0e795531 | 473 | if ((void *)e == (void *)newinfo->hook_entry[i]) |
22b440bf AV |
474 | break; |
475 | } | |
476 | /* beginning of a new chain | |
477 | if i == NF_BR_NUMHOOKS it must be a user defined chain */ | |
478 | if (i != NF_BR_NUMHOOKS || !e->bitmask) { | |
1da177e4 LT |
479 | /* this checks if the previous chain has as many entries |
480 | as it said it has */ | |
481 | if (*n != *cnt) { | |
482 | BUGPRINT("nentries does not equal the nr of entries " | |
9d6f229f | 483 | "in the chain\n"); |
1da177e4 LT |
484 | return -EINVAL; |
485 | } | |
1da177e4 LT |
486 | if (((struct ebt_entries *)e)->policy != EBT_DROP && |
487 | ((struct ebt_entries *)e)->policy != EBT_ACCEPT) { | |
488 | /* only RETURN from udc */ | |
489 | if (i != NF_BR_NUMHOOKS || | |
490 | ((struct ebt_entries *)e)->policy != EBT_RETURN) { | |
491 | BUGPRINT("bad policy\n"); | |
492 | return -EINVAL; | |
493 | } | |
494 | } | |
495 | if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */ | |
496 | (*udc_cnt)++; | |
1da177e4 LT |
497 | if (((struct ebt_entries *)e)->counter_offset != *totalcnt) { |
498 | BUGPRINT("counter_offset != totalcnt"); | |
499 | return -EINVAL; | |
500 | } | |
501 | *n = ((struct ebt_entries *)e)->nentries; | |
502 | *cnt = 0; | |
503 | return 0; | |
504 | } | |
505 | /* a plain old entry, heh */ | |
506 | if (sizeof(struct ebt_entry) > e->watchers_offset || | |
507 | e->watchers_offset > e->target_offset || | |
508 | e->target_offset >= e->next_offset) { | |
509 | BUGPRINT("entry offsets not in right order\n"); | |
510 | return -EINVAL; | |
511 | } | |
512 | /* this is not checked anywhere else */ | |
513 | if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target)) { | |
514 | BUGPRINT("target size too small\n"); | |
515 | return -EINVAL; | |
516 | } | |
1da177e4 LT |
517 | (*cnt)++; |
518 | (*totalcnt)++; | |
519 | return 0; | |
520 | } | |
521 | ||
522 | struct ebt_cl_stack | |
523 | { | |
524 | struct ebt_chainstack cs; | |
525 | int from; | |
526 | unsigned int hookmask; | |
527 | }; | |
528 | ||
529 | /* | |
530 | * we need these positions to check that the jumps to a different part of the | |
531 | * entries is a jump to the beginning of a new chain. | |
532 | */ | |
533 | static inline int | |
534 | ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo, | |
177abc34 | 535 | unsigned int *n, struct ebt_cl_stack *udc) |
1da177e4 LT |
536 | { |
537 | int i; | |
538 | ||
539 | /* we're only interested in chain starts */ | |
40642f95 | 540 | if (e->bitmask) |
1da177e4 LT |
541 | return 0; |
542 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
1da177e4 LT |
543 | if (newinfo->hook_entry[i] == (struct ebt_entries *)e) |
544 | break; | |
545 | } | |
546 | /* only care about udc */ | |
547 | if (i != NF_BR_NUMHOOKS) | |
548 | return 0; | |
549 | ||
550 | udc[*n].cs.chaininfo = (struct ebt_entries *)e; | |
551 | /* these initialisations are depended on later in check_chainloops() */ | |
552 | udc[*n].cs.n = 0; | |
553 | udc[*n].hookmask = 0; | |
554 | ||
555 | (*n)++; | |
556 | return 0; | |
557 | } | |
558 | ||
559 | static inline int | |
560 | ebt_cleanup_match(struct ebt_entry_match *m, unsigned int *i) | |
561 | { | |
6be3d859 JE |
562 | struct xt_mtdtor_param par; |
563 | ||
1da177e4 LT |
564 | if (i && (*i)-- == 0) |
565 | return 1; | |
1da177e4 | 566 | |
6be3d859 JE |
567 | par.match = m->u.match; |
568 | par.matchinfo = m->data; | |
916a917d | 569 | par.family = NFPROTO_BRIDGE; |
6be3d859 JE |
570 | if (par.match->destroy != NULL) |
571 | par.match->destroy(&par); | |
572 | module_put(par.match->me); | |
1da177e4 LT |
573 | return 0; |
574 | } | |
575 | ||
576 | static inline int | |
577 | ebt_cleanup_watcher(struct ebt_entry_watcher *w, unsigned int *i) | |
578 | { | |
a2df1648 JE |
579 | struct xt_tgdtor_param par; |
580 | ||
1da177e4 LT |
581 | if (i && (*i)-- == 0) |
582 | return 1; | |
1da177e4 | 583 | |
a2df1648 JE |
584 | par.target = w->u.watcher; |
585 | par.targinfo = w->data; | |
916a917d | 586 | par.family = NFPROTO_BRIDGE; |
a2df1648 JE |
587 | if (par.target->destroy != NULL) |
588 | par.target->destroy(&par); | |
589 | module_put(par.target->me); | |
1da177e4 LT |
590 | return 0; |
591 | } | |
592 | ||
593 | static inline int | |
594 | ebt_cleanup_entry(struct ebt_entry *e, unsigned int *cnt) | |
595 | { | |
a2df1648 | 596 | struct xt_tgdtor_param par; |
1da177e4 LT |
597 | struct ebt_entry_target *t; |
598 | ||
40642f95 | 599 | if (e->bitmask == 0) |
1da177e4 LT |
600 | return 0; |
601 | /* we're done */ | |
602 | if (cnt && (*cnt)-- == 0) | |
603 | return 1; | |
604 | EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, NULL); | |
605 | EBT_MATCH_ITERATE(e, ebt_cleanup_match, NULL); | |
606 | t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); | |
1da177e4 | 607 | |
a2df1648 JE |
608 | par.target = t->u.target; |
609 | par.targinfo = t->data; | |
916a917d | 610 | par.family = NFPROTO_BRIDGE; |
a2df1648 JE |
611 | if (par.target->destroy != NULL) |
612 | par.target->destroy(&par); | |
613 | module_put(par.target->me); | |
1da177e4 LT |
614 | return 0; |
615 | } | |
616 | ||
617 | static inline int | |
618 | ebt_check_entry(struct ebt_entry *e, struct ebt_table_info *newinfo, | |
f7da79d9 | 619 | const char *name, unsigned int *cnt, |
1da177e4 LT |
620 | struct ebt_cl_stack *cl_s, unsigned int udc_cnt) |
621 | { | |
622 | struct ebt_entry_target *t; | |
043ef46c | 623 | struct xt_target *target; |
1da177e4 | 624 | unsigned int i, j, hook = 0, hookmask = 0; |
44f9a2fd | 625 | size_t gap; |
1da177e4 | 626 | int ret; |
6be3d859 | 627 | struct xt_mtchk_param mtpar; |
af5d6dc2 | 628 | struct xt_tgchk_param tgpar; |
1da177e4 LT |
629 | |
630 | /* don't mess with the struct ebt_entries */ | |
40642f95 | 631 | if (e->bitmask == 0) |
1da177e4 LT |
632 | return 0; |
633 | ||
634 | if (e->bitmask & ~EBT_F_MASK) { | |
635 | BUGPRINT("Unknown flag for bitmask\n"); | |
636 | return -EINVAL; | |
637 | } | |
638 | if (e->invflags & ~EBT_INV_MASK) { | |
639 | BUGPRINT("Unknown flag for inv bitmask\n"); | |
640 | return -EINVAL; | |
641 | } | |
642 | if ( (e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3) ) { | |
643 | BUGPRINT("NOPROTO & 802_3 not allowed\n"); | |
644 | return -EINVAL; | |
645 | } | |
646 | /* what hook do we belong to? */ | |
647 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
f7da79d9 | 648 | if (!newinfo->hook_entry[i]) |
1da177e4 LT |
649 | continue; |
650 | if ((char *)newinfo->hook_entry[i] < (char *)e) | |
651 | hook = i; | |
652 | else | |
653 | break; | |
654 | } | |
655 | /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on | |
656 | a base chain */ | |
657 | if (i < NF_BR_NUMHOOKS) | |
658 | hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS); | |
659 | else { | |
660 | for (i = 0; i < udc_cnt; i++) | |
661 | if ((char *)(cl_s[i].cs.chaininfo) > (char *)e) | |
662 | break; | |
663 | if (i == 0) | |
664 | hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS); | |
665 | else | |
666 | hookmask = cl_s[i - 1].hookmask; | |
667 | } | |
668 | i = 0; | |
9b4fce7a | 669 | |
af5d6dc2 JE |
670 | mtpar.table = tgpar.table = name; |
671 | mtpar.entryinfo = tgpar.entryinfo = e; | |
672 | mtpar.hook_mask = tgpar.hook_mask = hookmask; | |
916a917d | 673 | mtpar.family = tgpar.family = NFPROTO_BRIDGE; |
6be3d859 | 674 | ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i); |
1da177e4 LT |
675 | if (ret != 0) |
676 | goto cleanup_matches; | |
677 | j = 0; | |
af5d6dc2 | 678 | ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j); |
1da177e4 LT |
679 | if (ret != 0) |
680 | goto cleanup_watchers; | |
681 | t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); | |
44f9a2fd | 682 | gap = e->next_offset - e->target_offset; |
1da177e4 | 683 | |
043ef46c JE |
684 | target = try_then_request_module( |
685 | xt_find_target(NFPROTO_BRIDGE, t->u.name, 0), | |
686 | "ebt_%s", t->u.name); | |
687 | if (IS_ERR(target)) { | |
688 | ret = PTR_ERR(target); | |
001a18d3 | 689 | goto cleanup_watchers; |
043ef46c JE |
690 | } else if (target == NULL) { |
691 | ret = -ENOENT; | |
001a18d3 JE |
692 | goto cleanup_watchers; |
693 | } | |
694 | ||
1da177e4 LT |
695 | t->u.target = target; |
696 | if (t->u.target == &ebt_standard_target) { | |
14197d54 | 697 | if (gap < sizeof(struct ebt_standard_target)) { |
1da177e4 LT |
698 | BUGPRINT("Standard target size too big\n"); |
699 | ret = -EFAULT; | |
700 | goto cleanup_watchers; | |
701 | } | |
702 | if (((struct ebt_standard_target *)t)->verdict < | |
703 | -NUM_STANDARD_TARGETS) { | |
704 | BUGPRINT("Invalid standard target\n"); | |
705 | ret = -EFAULT; | |
706 | goto cleanup_watchers; | |
707 | } | |
18219d3f JE |
708 | } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) { |
709 | module_put(t->u.target->me); | |
710 | ret = -EFAULT; | |
711 | goto cleanup_watchers; | |
043ef46c JE |
712 | } |
713 | ||
af5d6dc2 JE |
714 | tgpar.target = target; |
715 | tgpar.targinfo = t->data; | |
916a917d | 716 | ret = xt_check_target(&tgpar, t->target_size, |
af5d6dc2 | 717 | e->ethproto, e->invflags & EBT_IPROTO); |
043ef46c JE |
718 | if (ret < 0) { |
719 | module_put(target->me); | |
18219d3f | 720 | goto cleanup_watchers; |
1da177e4 LT |
721 | } |
722 | (*cnt)++; | |
723 | return 0; | |
724 | cleanup_watchers: | |
725 | EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, &j); | |
726 | cleanup_matches: | |
727 | EBT_MATCH_ITERATE(e, ebt_cleanup_match, &i); | |
728 | return ret; | |
729 | } | |
730 | ||
731 | /* | |
732 | * checks for loops and sets the hook mask for udc | |
733 | * the hook mask for udc tells us from which base chains the udc can be | |
734 | * accessed. This mask is a parameter to the check() functions of the extensions | |
735 | */ | |
736 | static int check_chainloops(struct ebt_entries *chain, struct ebt_cl_stack *cl_s, | |
737 | unsigned int udc_cnt, unsigned int hooknr, char *base) | |
738 | { | |
739 | int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict; | |
740 | struct ebt_entry *e = (struct ebt_entry *)chain->data; | |
741 | struct ebt_entry_target *t; | |
742 | ||
743 | while (pos < nentries || chain_nr != -1) { | |
744 | /* end of udc, go back one 'recursion' step */ | |
745 | if (pos == nentries) { | |
746 | /* put back values of the time when this chain was called */ | |
747 | e = cl_s[chain_nr].cs.e; | |
748 | if (cl_s[chain_nr].from != -1) | |
749 | nentries = | |
750 | cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries; | |
751 | else | |
752 | nentries = chain->nentries; | |
753 | pos = cl_s[chain_nr].cs.n; | |
754 | /* make sure we won't see a loop that isn't one */ | |
755 | cl_s[chain_nr].cs.n = 0; | |
756 | chain_nr = cl_s[chain_nr].from; | |
757 | if (pos == nentries) | |
758 | continue; | |
759 | } | |
760 | t = (struct ebt_entry_target *) | |
761 | (((char *)e) + e->target_offset); | |
762 | if (strcmp(t->u.name, EBT_STANDARD_TARGET)) | |
763 | goto letscontinue; | |
764 | if (e->target_offset + sizeof(struct ebt_standard_target) > | |
765 | e->next_offset) { | |
766 | BUGPRINT("Standard target size too big\n"); | |
767 | return -1; | |
768 | } | |
769 | verdict = ((struct ebt_standard_target *)t)->verdict; | |
770 | if (verdict >= 0) { /* jump to another chain */ | |
771 | struct ebt_entries *hlp2 = | |
772 | (struct ebt_entries *)(base + verdict); | |
773 | for (i = 0; i < udc_cnt; i++) | |
774 | if (hlp2 == cl_s[i].cs.chaininfo) | |
775 | break; | |
776 | /* bad destination or loop */ | |
777 | if (i == udc_cnt) { | |
778 | BUGPRINT("bad destination\n"); | |
779 | return -1; | |
780 | } | |
781 | if (cl_s[i].cs.n) { | |
782 | BUGPRINT("loop\n"); | |
783 | return -1; | |
784 | } | |
98a0824a AV |
785 | if (cl_s[i].hookmask & (1 << hooknr)) |
786 | goto letscontinue; | |
787 | /* this can't be 0, so the loop test is correct */ | |
1da177e4 LT |
788 | cl_s[i].cs.n = pos + 1; |
789 | pos = 0; | |
790 | cl_s[i].cs.e = ((void *)e + e->next_offset); | |
791 | e = (struct ebt_entry *)(hlp2->data); | |
792 | nentries = hlp2->nentries; | |
793 | cl_s[i].from = chain_nr; | |
794 | chain_nr = i; | |
795 | /* this udc is accessible from the base chain for hooknr */ | |
796 | cl_s[i].hookmask |= (1 << hooknr); | |
797 | continue; | |
798 | } | |
799 | letscontinue: | |
800 | e = (void *)e + e->next_offset; | |
801 | pos++; | |
802 | } | |
803 | return 0; | |
804 | } | |
805 | ||
806 | /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */ | |
1bc2326c | 807 | static int translate_table(char *name, struct ebt_table_info *newinfo) |
1da177e4 LT |
808 | { |
809 | unsigned int i, j, k, udc_cnt; | |
810 | int ret; | |
811 | struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */ | |
812 | ||
813 | i = 0; | |
1f072c96 | 814 | while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i]) |
1da177e4 LT |
815 | i++; |
816 | if (i == NF_BR_NUMHOOKS) { | |
817 | BUGPRINT("No valid hooks specified\n"); | |
818 | return -EINVAL; | |
819 | } | |
1f072c96 | 820 | if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) { |
1da177e4 LT |
821 | BUGPRINT("Chains don't start at beginning\n"); |
822 | return -EINVAL; | |
823 | } | |
824 | /* make sure chains are ordered after each other in same order | |
825 | as their corresponding hooks */ | |
826 | for (j = i + 1; j < NF_BR_NUMHOOKS; j++) { | |
1f072c96 | 827 | if (!newinfo->hook_entry[j]) |
1da177e4 | 828 | continue; |
1f072c96 | 829 | if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) { |
1da177e4 LT |
830 | BUGPRINT("Hook order must be followed\n"); |
831 | return -EINVAL; | |
832 | } | |
833 | i = j; | |
834 | } | |
835 | ||
1da177e4 LT |
836 | /* do some early checkings and initialize some things */ |
837 | i = 0; /* holds the expected nr. of entries for the chain */ | |
838 | j = 0; /* holds the up to now counted entries for the chain */ | |
839 | k = 0; /* holds the total nr. of entries, should equal | |
9d6f229f | 840 | newinfo->nentries afterwards */ |
1da177e4 LT |
841 | udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */ |
842 | ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
0e795531 AV |
843 | ebt_check_entry_size_and_hooks, newinfo, |
844 | &i, &j, &k, &udc_cnt); | |
1da177e4 LT |
845 | |
846 | if (ret != 0) | |
847 | return ret; | |
848 | ||
849 | if (i != j) { | |
850 | BUGPRINT("nentries does not equal the nr of entries in the " | |
9d6f229f | 851 | "(last) chain\n"); |
1da177e4 LT |
852 | return -EINVAL; |
853 | } | |
854 | if (k != newinfo->nentries) { | |
855 | BUGPRINT("Total nentries is wrong\n"); | |
856 | return -EINVAL; | |
857 | } | |
858 | ||
1da177e4 LT |
859 | /* get the location of the udc, put them in an array |
860 | while we're at it, allocate the chainstack */ | |
861 | if (udc_cnt) { | |
862 | /* this will get free'd in do_replace()/ebt_register_table() | |
863 | if an error occurs */ | |
7ad4d2f6 | 864 | newinfo->chainstack = |
53b8a315 | 865 | vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack))); |
1da177e4 LT |
866 | if (!newinfo->chainstack) |
867 | return -ENOMEM; | |
6f912042 | 868 | for_each_possible_cpu(i) { |
1da177e4 | 869 | newinfo->chainstack[i] = |
18bc89aa | 870 | vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0]))); |
1da177e4 LT |
871 | if (!newinfo->chainstack[i]) { |
872 | while (i) | |
873 | vfree(newinfo->chainstack[--i]); | |
874 | vfree(newinfo->chainstack); | |
875 | newinfo->chainstack = NULL; | |
876 | return -ENOMEM; | |
877 | } | |
878 | } | |
879 | ||
18bc89aa | 880 | cl_s = vmalloc(udc_cnt * sizeof(*cl_s)); |
1da177e4 LT |
881 | if (!cl_s) |
882 | return -ENOMEM; | |
883 | i = 0; /* the i'th udc */ | |
884 | EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
177abc34 | 885 | ebt_get_udc_positions, newinfo, &i, cl_s); |
1da177e4 LT |
886 | /* sanity check */ |
887 | if (i != udc_cnt) { | |
888 | BUGPRINT("i != udc_cnt\n"); | |
889 | vfree(cl_s); | |
890 | return -EFAULT; | |
891 | } | |
892 | } | |
893 | ||
894 | /* Check for loops */ | |
895 | for (i = 0; i < NF_BR_NUMHOOKS; i++) | |
1f072c96 | 896 | if (newinfo->hook_entry[i]) |
1da177e4 LT |
897 | if (check_chainloops(newinfo->hook_entry[i], |
898 | cl_s, udc_cnt, i, newinfo->entries)) { | |
68d31872 | 899 | vfree(cl_s); |
1da177e4 LT |
900 | return -EINVAL; |
901 | } | |
902 | ||
96de0e25 | 903 | /* we now know the following (along with E=mc²): |
1da177e4 LT |
904 | - the nr of entries in each chain is right |
905 | - the size of the allocated space is right | |
906 | - all valid hooks have a corresponding chain | |
907 | - there are no loops | |
908 | - wrong data can still be on the level of a single entry | |
909 | - could be there are jumps to places that are not the | |
910 | beginning of a chain. This can only occur in chains that | |
911 | are not accessible from any base chains, so we don't care. */ | |
912 | ||
913 | /* used to know what we need to clean up if something goes wrong */ | |
914 | i = 0; | |
915 | ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
1bc2326c | 916 | ebt_check_entry, newinfo, name, &i, cl_s, udc_cnt); |
1da177e4 LT |
917 | if (ret != 0) { |
918 | EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
919 | ebt_cleanup_entry, &i); | |
920 | } | |
68d31872 | 921 | vfree(cl_s); |
1da177e4 LT |
922 | return ret; |
923 | } | |
924 | ||
925 | /* called under write_lock */ | |
926 | static void get_counters(struct ebt_counter *oldcounters, | |
927 | struct ebt_counter *counters, unsigned int nentries) | |
928 | { | |
929 | int i, cpu; | |
930 | struct ebt_counter *counter_base; | |
931 | ||
932 | /* counters of cpu 0 */ | |
933 | memcpy(counters, oldcounters, | |
c8923c6b DM |
934 | sizeof(struct ebt_counter) * nentries); |
935 | ||
1da177e4 | 936 | /* add other counters to those of cpu 0 */ |
6f912042 | 937 | for_each_possible_cpu(cpu) { |
c8923c6b DM |
938 | if (cpu == 0) |
939 | continue; | |
1da177e4 LT |
940 | counter_base = COUNTER_BASE(oldcounters, nentries, cpu); |
941 | for (i = 0; i < nentries; i++) { | |
942 | counters[i].pcnt += counter_base[i].pcnt; | |
943 | counters[i].bcnt += counter_base[i].bcnt; | |
944 | } | |
945 | } | |
946 | } | |
947 | ||
948 | /* replace the table */ | |
511061e2 | 949 | static int do_replace(struct net *net, void __user *user, unsigned int len) |
1da177e4 LT |
950 | { |
951 | int ret, i, countersize; | |
952 | struct ebt_table_info *newinfo; | |
953 | struct ebt_replace tmp; | |
954 | struct ebt_table *t; | |
955 | struct ebt_counter *counterstmp = NULL; | |
956 | /* used to be able to unlock earlier */ | |
957 | struct ebt_table_info *table; | |
958 | ||
959 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) | |
960 | return -EFAULT; | |
961 | ||
962 | if (len != sizeof(tmp) + tmp.entries_size) { | |
963 | BUGPRINT("Wrong len argument\n"); | |
964 | return -EINVAL; | |
965 | } | |
966 | ||
967 | if (tmp.entries_size == 0) { | |
968 | BUGPRINT("Entries_size never zero\n"); | |
969 | return -EINVAL; | |
970 | } | |
ee4bb818 KK |
971 | /* overflow check */ |
972 | if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) / NR_CPUS - | |
973 | SMP_CACHE_BYTES) / sizeof(struct ebt_counter)) | |
974 | return -ENOMEM; | |
975 | if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) | |
976 | return -ENOMEM; | |
977 | ||
53b8a315 | 978 | countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids; |
18bc89aa | 979 | newinfo = vmalloc(sizeof(*newinfo) + countersize); |
1da177e4 LT |
980 | if (!newinfo) |
981 | return -ENOMEM; | |
982 | ||
983 | if (countersize) | |
984 | memset(newinfo->counters, 0, countersize); | |
985 | ||
8b3a7005 | 986 | newinfo->entries = vmalloc(tmp.entries_size); |
1da177e4 LT |
987 | if (!newinfo->entries) { |
988 | ret = -ENOMEM; | |
989 | goto free_newinfo; | |
990 | } | |
991 | if (copy_from_user( | |
992 | newinfo->entries, tmp.entries, tmp.entries_size) != 0) { | |
993 | BUGPRINT("Couldn't copy entries from userspace\n"); | |
994 | ret = -EFAULT; | |
995 | goto free_entries; | |
996 | } | |
997 | ||
998 | /* the user wants counters back | |
999 | the check on the size is done later, when we have the lock */ | |
1000 | if (tmp.num_counters) { | |
18bc89aa | 1001 | counterstmp = vmalloc(tmp.num_counters * sizeof(*counterstmp)); |
1da177e4 LT |
1002 | if (!counterstmp) { |
1003 | ret = -ENOMEM; | |
1004 | goto free_entries; | |
1005 | } | |
1006 | } | |
1007 | else | |
1008 | counterstmp = NULL; | |
1009 | ||
1010 | /* this can get initialized by translate_table() */ | |
1011 | newinfo->chainstack = NULL; | |
1bc2326c AV |
1012 | ret = ebt_verify_pointers(&tmp, newinfo); |
1013 | if (ret != 0) | |
1014 | goto free_counterstmp; | |
1015 | ||
1016 | ret = translate_table(tmp.name, newinfo); | |
1da177e4 LT |
1017 | |
1018 | if (ret != 0) | |
1019 | goto free_counterstmp; | |
1020 | ||
511061e2 | 1021 | t = find_table_lock(net, tmp.name, &ret, &ebt_mutex); |
1da177e4 LT |
1022 | if (!t) { |
1023 | ret = -ENOENT; | |
1024 | goto free_iterate; | |
1025 | } | |
1026 | ||
1027 | /* the table doesn't like it */ | |
1028 | if (t->check && (ret = t->check(newinfo, tmp.valid_hooks))) | |
1029 | goto free_unlock; | |
1030 | ||
1031 | if (tmp.num_counters && tmp.num_counters != t->private->nentries) { | |
1032 | BUGPRINT("Wrong nr. of counters requested\n"); | |
1033 | ret = -EINVAL; | |
1034 | goto free_unlock; | |
1035 | } | |
1036 | ||
1037 | /* we have the mutex lock, so no danger in reading this pointer */ | |
1038 | table = t->private; | |
1039 | /* make sure the table can only be rmmod'ed if it contains no rules */ | |
1040 | if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) { | |
1041 | ret = -ENOENT; | |
1042 | goto free_unlock; | |
1043 | } else if (table->nentries && !newinfo->nentries) | |
1044 | module_put(t->me); | |
1045 | /* we need an atomic snapshot of the counters */ | |
1046 | write_lock_bh(&t->lock); | |
1047 | if (tmp.num_counters) | |
1048 | get_counters(t->private->counters, counterstmp, | |
1049 | t->private->nentries); | |
1050 | ||
1051 | t->private = newinfo; | |
1052 | write_unlock_bh(&t->lock); | |
57b47a53 | 1053 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1054 | /* so, a user can change the chains while having messed up her counter |
1055 | allocation. Only reason why this is done is because this way the lock | |
1056 | is held only once, while this doesn't bring the kernel into a | |
1057 | dangerous state. */ | |
1058 | if (tmp.num_counters && | |
1059 | copy_to_user(tmp.counters, counterstmp, | |
1060 | tmp.num_counters * sizeof(struct ebt_counter))) { | |
1061 | BUGPRINT("Couldn't copy counters to userspace\n"); | |
1062 | ret = -EFAULT; | |
1063 | } | |
1064 | else | |
1065 | ret = 0; | |
1066 | ||
1067 | /* decrease module count and free resources */ | |
1068 | EBT_ENTRY_ITERATE(table->entries, table->entries_size, | |
1069 | ebt_cleanup_entry, NULL); | |
1070 | ||
1071 | vfree(table->entries); | |
1072 | if (table->chainstack) { | |
6f912042 | 1073 | for_each_possible_cpu(i) |
1da177e4 LT |
1074 | vfree(table->chainstack[i]); |
1075 | vfree(table->chainstack); | |
1076 | } | |
1077 | vfree(table); | |
1078 | ||
68d31872 | 1079 | vfree(counterstmp); |
1da177e4 LT |
1080 | return ret; |
1081 | ||
1082 | free_unlock: | |
57b47a53 | 1083 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1084 | free_iterate: |
1085 | EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
1086 | ebt_cleanup_entry, NULL); | |
1087 | free_counterstmp: | |
68d31872 | 1088 | vfree(counterstmp); |
1da177e4 LT |
1089 | /* can be initialized in translate_table() */ |
1090 | if (newinfo->chainstack) { | |
6f912042 | 1091 | for_each_possible_cpu(i) |
1da177e4 LT |
1092 | vfree(newinfo->chainstack[i]); |
1093 | vfree(newinfo->chainstack); | |
1094 | } | |
1095 | free_entries: | |
68d31872 | 1096 | vfree(newinfo->entries); |
1da177e4 | 1097 | free_newinfo: |
68d31872 | 1098 | vfree(newinfo); |
1da177e4 LT |
1099 | return ret; |
1100 | } | |
1101 | ||
6beceee5 | 1102 | struct ebt_table *ebt_register_table(struct net *net, struct ebt_table *table) |
1da177e4 LT |
1103 | { |
1104 | struct ebt_table_info *newinfo; | |
df0933dc | 1105 | struct ebt_table *t; |
1e419cd9 | 1106 | struct ebt_replace_kernel *repl; |
1da177e4 | 1107 | int ret, i, countersize; |
df07a81e | 1108 | void *p; |
1da177e4 | 1109 | |
df07a81e AV |
1110 | if (!table || !(repl = table->table) || !repl->entries || |
1111 | repl->entries_size == 0 || | |
1112 | repl->counters || table->private) { | |
1da177e4 | 1113 | BUGPRINT("Bad table data for ebt_register_table!!!\n"); |
6beceee5 AD |
1114 | return ERR_PTR(-EINVAL); |
1115 | } | |
1116 | ||
1117 | /* Don't add one table to multiple lists. */ | |
1118 | table = kmemdup(table, sizeof(struct ebt_table), GFP_KERNEL); | |
1119 | if (!table) { | |
1120 | ret = -ENOMEM; | |
1121 | goto out; | |
1da177e4 LT |
1122 | } |
1123 | ||
53b8a315 | 1124 | countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids; |
18bc89aa | 1125 | newinfo = vmalloc(sizeof(*newinfo) + countersize); |
1da177e4 LT |
1126 | ret = -ENOMEM; |
1127 | if (!newinfo) | |
6beceee5 | 1128 | goto free_table; |
1da177e4 | 1129 | |
df07a81e AV |
1130 | p = vmalloc(repl->entries_size); |
1131 | if (!p) | |
1da177e4 LT |
1132 | goto free_newinfo; |
1133 | ||
df07a81e AV |
1134 | memcpy(p, repl->entries, repl->entries_size); |
1135 | newinfo->entries = p; | |
1136 | ||
1137 | newinfo->entries_size = repl->entries_size; | |
1138 | newinfo->nentries = repl->nentries; | |
1da177e4 LT |
1139 | |
1140 | if (countersize) | |
1141 | memset(newinfo->counters, 0, countersize); | |
1142 | ||
1143 | /* fill in newinfo and parse the entries */ | |
1144 | newinfo->chainstack = NULL; | |
df07a81e AV |
1145 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { |
1146 | if ((repl->valid_hooks & (1 << i)) == 0) | |
1147 | newinfo->hook_entry[i] = NULL; | |
1148 | else | |
1149 | newinfo->hook_entry[i] = p + | |
1150 | ((char *)repl->hook_entry[i] - repl->entries); | |
1151 | } | |
1152 | ret = translate_table(repl->name, newinfo); | |
1da177e4 LT |
1153 | if (ret != 0) { |
1154 | BUGPRINT("Translate_table failed\n"); | |
1155 | goto free_chainstack; | |
1156 | } | |
1157 | ||
1158 | if (table->check && table->check(newinfo, table->valid_hooks)) { | |
1159 | BUGPRINT("The table doesn't like its own initial data, lol\n"); | |
6beceee5 | 1160 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
1161 | } |
1162 | ||
1163 | table->private = newinfo; | |
1164 | rwlock_init(&table->lock); | |
57b47a53 | 1165 | ret = mutex_lock_interruptible(&ebt_mutex); |
1da177e4 LT |
1166 | if (ret != 0) |
1167 | goto free_chainstack; | |
1168 | ||
511061e2 | 1169 | list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) { |
df0933dc PM |
1170 | if (strcmp(t->name, table->name) == 0) { |
1171 | ret = -EEXIST; | |
1172 | BUGPRINT("Table name already exists\n"); | |
1173 | goto free_unlock; | |
1174 | } | |
1da177e4 LT |
1175 | } |
1176 | ||
1177 | /* Hold a reference count if the chains aren't empty */ | |
1178 | if (newinfo->nentries && !try_module_get(table->me)) { | |
1179 | ret = -ENOENT; | |
1180 | goto free_unlock; | |
1181 | } | |
511061e2 | 1182 | list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]); |
57b47a53 | 1183 | mutex_unlock(&ebt_mutex); |
6beceee5 | 1184 | return table; |
1da177e4 | 1185 | free_unlock: |
57b47a53 | 1186 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1187 | free_chainstack: |
1188 | if (newinfo->chainstack) { | |
6f912042 | 1189 | for_each_possible_cpu(i) |
1da177e4 LT |
1190 | vfree(newinfo->chainstack[i]); |
1191 | vfree(newinfo->chainstack); | |
1192 | } | |
1193 | vfree(newinfo->entries); | |
1194 | free_newinfo: | |
1195 | vfree(newinfo); | |
6beceee5 AD |
1196 | free_table: |
1197 | kfree(table); | |
1198 | out: | |
1199 | return ERR_PTR(ret); | |
1da177e4 LT |
1200 | } |
1201 | ||
1202 | void ebt_unregister_table(struct ebt_table *table) | |
1203 | { | |
1204 | int i; | |
1205 | ||
1206 | if (!table) { | |
1207 | BUGPRINT("Request to unregister NULL table!!!\n"); | |
1208 | return; | |
1209 | } | |
57b47a53 | 1210 | mutex_lock(&ebt_mutex); |
df0933dc | 1211 | list_del(&table->list); |
57b47a53 | 1212 | mutex_unlock(&ebt_mutex); |
dbcdf85a AD |
1213 | EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size, |
1214 | ebt_cleanup_entry, NULL); | |
1215 | if (table->private->nentries) | |
1216 | module_put(table->me); | |
68d31872 | 1217 | vfree(table->private->entries); |
1da177e4 | 1218 | if (table->private->chainstack) { |
6f912042 | 1219 | for_each_possible_cpu(i) |
1da177e4 LT |
1220 | vfree(table->private->chainstack[i]); |
1221 | vfree(table->private->chainstack); | |
1222 | } | |
1223 | vfree(table->private); | |
6beceee5 | 1224 | kfree(table); |
1da177e4 LT |
1225 | } |
1226 | ||
1227 | /* userspace just supplied us with counters */ | |
511061e2 | 1228 | static int update_counters(struct net *net, void __user *user, unsigned int len) |
1da177e4 LT |
1229 | { |
1230 | int i, ret; | |
1231 | struct ebt_counter *tmp; | |
1232 | struct ebt_replace hlp; | |
1233 | struct ebt_table *t; | |
1234 | ||
1235 | if (copy_from_user(&hlp, user, sizeof(hlp))) | |
1236 | return -EFAULT; | |
1237 | ||
1238 | if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter)) | |
1239 | return -EINVAL; | |
1240 | if (hlp.num_counters == 0) | |
1241 | return -EINVAL; | |
1242 | ||
18bc89aa | 1243 | if (!(tmp = vmalloc(hlp.num_counters * sizeof(*tmp)))) { |
1da177e4 LT |
1244 | MEMPRINT("Update_counters && nomemory\n"); |
1245 | return -ENOMEM; | |
1246 | } | |
1247 | ||
511061e2 | 1248 | t = find_table_lock(net, hlp.name, &ret, &ebt_mutex); |
1da177e4 LT |
1249 | if (!t) |
1250 | goto free_tmp; | |
1251 | ||
1252 | if (hlp.num_counters != t->private->nentries) { | |
1253 | BUGPRINT("Wrong nr of counters\n"); | |
1254 | ret = -EINVAL; | |
1255 | goto unlock_mutex; | |
1256 | } | |
1257 | ||
1258 | if ( copy_from_user(tmp, hlp.counters, | |
1259 | hlp.num_counters * sizeof(struct ebt_counter)) ) { | |
1260 | BUGPRINT("Updata_counters && !cfu\n"); | |
1261 | ret = -EFAULT; | |
1262 | goto unlock_mutex; | |
1263 | } | |
1264 | ||
1265 | /* we want an atomic add of the counters */ | |
1266 | write_lock_bh(&t->lock); | |
1267 | ||
1268 | /* we add to the counters of the first cpu */ | |
1269 | for (i = 0; i < hlp.num_counters; i++) { | |
1270 | t->private->counters[i].pcnt += tmp[i].pcnt; | |
1271 | t->private->counters[i].bcnt += tmp[i].bcnt; | |
1272 | } | |
1273 | ||
1274 | write_unlock_bh(&t->lock); | |
1275 | ret = 0; | |
1276 | unlock_mutex: | |
57b47a53 | 1277 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1278 | free_tmp: |
1279 | vfree(tmp); | |
1280 | return ret; | |
1281 | } | |
1282 | ||
1283 | static inline int ebt_make_matchname(struct ebt_entry_match *m, | |
1e419cd9 | 1284 | char *base, char __user *ubase) |
1da177e4 | 1285 | { |
1e419cd9 | 1286 | char __user *hlp = ubase + ((char *)m - base); |
1da177e4 LT |
1287 | if (copy_to_user(hlp, m->u.match->name, EBT_FUNCTION_MAXNAMELEN)) |
1288 | return -EFAULT; | |
1289 | return 0; | |
1290 | } | |
1291 | ||
1292 | static inline int ebt_make_watchername(struct ebt_entry_watcher *w, | |
1e419cd9 | 1293 | char *base, char __user *ubase) |
1da177e4 | 1294 | { |
1e419cd9 | 1295 | char __user *hlp = ubase + ((char *)w - base); |
1da177e4 LT |
1296 | if (copy_to_user(hlp , w->u.watcher->name, EBT_FUNCTION_MAXNAMELEN)) |
1297 | return -EFAULT; | |
1298 | return 0; | |
1299 | } | |
1300 | ||
1e419cd9 | 1301 | static inline int ebt_make_names(struct ebt_entry *e, char *base, char __user *ubase) |
1da177e4 LT |
1302 | { |
1303 | int ret; | |
1e419cd9 | 1304 | char __user *hlp; |
1da177e4 LT |
1305 | struct ebt_entry_target *t; |
1306 | ||
40642f95 | 1307 | if (e->bitmask == 0) |
1da177e4 LT |
1308 | return 0; |
1309 | ||
1e419cd9 | 1310 | hlp = ubase + (((char *)e + e->target_offset) - base); |
1da177e4 | 1311 | t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); |
9d6f229f | 1312 | |
1da177e4 LT |
1313 | ret = EBT_MATCH_ITERATE(e, ebt_make_matchname, base, ubase); |
1314 | if (ret != 0) | |
1315 | return ret; | |
1316 | ret = EBT_WATCHER_ITERATE(e, ebt_make_watchername, base, ubase); | |
1317 | if (ret != 0) | |
1318 | return ret; | |
1319 | if (copy_to_user(hlp, t->u.target->name, EBT_FUNCTION_MAXNAMELEN)) | |
1320 | return -EFAULT; | |
1321 | return 0; | |
1322 | } | |
1323 | ||
57b47a53 | 1324 | /* called with ebt_mutex locked */ |
1da177e4 LT |
1325 | static int copy_everything_to_user(struct ebt_table *t, void __user *user, |
1326 | int *len, int cmd) | |
1327 | { | |
1328 | struct ebt_replace tmp; | |
1329 | struct ebt_counter *counterstmp, *oldcounters; | |
1330 | unsigned int entries_size, nentries; | |
1331 | char *entries; | |
1332 | ||
1333 | if (cmd == EBT_SO_GET_ENTRIES) { | |
1334 | entries_size = t->private->entries_size; | |
1335 | nentries = t->private->nentries; | |
1336 | entries = t->private->entries; | |
1337 | oldcounters = t->private->counters; | |
1338 | } else { | |
1339 | entries_size = t->table->entries_size; | |
1340 | nentries = t->table->nentries; | |
1341 | entries = t->table->entries; | |
1342 | oldcounters = t->table->counters; | |
1343 | } | |
1344 | ||
1345 | if (copy_from_user(&tmp, user, sizeof(tmp))) { | |
1346 | BUGPRINT("Cfu didn't work\n"); | |
1347 | return -EFAULT; | |
1348 | } | |
1349 | ||
1350 | if (*len != sizeof(struct ebt_replace) + entries_size + | |
1351 | (tmp.num_counters? nentries * sizeof(struct ebt_counter): 0)) { | |
1352 | BUGPRINT("Wrong size\n"); | |
1353 | return -EINVAL; | |
1354 | } | |
1355 | ||
1356 | if (tmp.nentries != nentries) { | |
1357 | BUGPRINT("Nentries wrong\n"); | |
1358 | return -EINVAL; | |
1359 | } | |
1360 | ||
1361 | if (tmp.entries_size != entries_size) { | |
1362 | BUGPRINT("Wrong size\n"); | |
1363 | return -EINVAL; | |
1364 | } | |
1365 | ||
1366 | /* userspace might not need the counters */ | |
1367 | if (tmp.num_counters) { | |
1368 | if (tmp.num_counters != nentries) { | |
1369 | BUGPRINT("Num_counters wrong\n"); | |
1370 | return -EINVAL; | |
1371 | } | |
18bc89aa | 1372 | counterstmp = vmalloc(nentries * sizeof(*counterstmp)); |
1da177e4 LT |
1373 | if (!counterstmp) { |
1374 | MEMPRINT("Couldn't copy counters, out of memory\n"); | |
1375 | return -ENOMEM; | |
1376 | } | |
1377 | write_lock_bh(&t->lock); | |
1378 | get_counters(oldcounters, counterstmp, nentries); | |
1379 | write_unlock_bh(&t->lock); | |
1380 | ||
1381 | if (copy_to_user(tmp.counters, counterstmp, | |
1382 | nentries * sizeof(struct ebt_counter))) { | |
1383 | BUGPRINT("Couldn't copy counters to userspace\n"); | |
1384 | vfree(counterstmp); | |
1385 | return -EFAULT; | |
1386 | } | |
1387 | vfree(counterstmp); | |
1388 | } | |
1389 | ||
1390 | if (copy_to_user(tmp.entries, entries, entries_size)) { | |
1391 | BUGPRINT("Couldn't copy entries to userspace\n"); | |
1392 | return -EFAULT; | |
1393 | } | |
1394 | /* set the match/watcher/target names right */ | |
1395 | return EBT_ENTRY_ITERATE(entries, entries_size, | |
1396 | ebt_make_names, entries, tmp.entries); | |
1397 | } | |
1398 | ||
1399 | static int do_ebt_set_ctl(struct sock *sk, | |
1400 | int cmd, void __user *user, unsigned int len) | |
1401 | { | |
1402 | int ret; | |
1403 | ||
1404 | switch(cmd) { | |
1405 | case EBT_SO_SET_ENTRIES: | |
511061e2 | 1406 | ret = do_replace(sock_net(sk), user, len); |
1da177e4 LT |
1407 | break; |
1408 | case EBT_SO_SET_COUNTERS: | |
511061e2 | 1409 | ret = update_counters(sock_net(sk), user, len); |
1da177e4 LT |
1410 | break; |
1411 | default: | |
1412 | ret = -EINVAL; | |
1413 | } | |
1414 | return ret; | |
1415 | } | |
1416 | ||
1417 | static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) | |
1418 | { | |
1419 | int ret; | |
1420 | struct ebt_replace tmp; | |
1421 | struct ebt_table *t; | |
1422 | ||
1423 | if (copy_from_user(&tmp, user, sizeof(tmp))) | |
1424 | return -EFAULT; | |
1425 | ||
511061e2 | 1426 | t = find_table_lock(sock_net(sk), tmp.name, &ret, &ebt_mutex); |
1da177e4 LT |
1427 | if (!t) |
1428 | return ret; | |
1429 | ||
1430 | switch(cmd) { | |
1431 | case EBT_SO_GET_INFO: | |
1432 | case EBT_SO_GET_INIT_INFO: | |
1433 | if (*len != sizeof(struct ebt_replace)){ | |
1434 | ret = -EINVAL; | |
57b47a53 | 1435 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1436 | break; |
1437 | } | |
1438 | if (cmd == EBT_SO_GET_INFO) { | |
1439 | tmp.nentries = t->private->nentries; | |
1440 | tmp.entries_size = t->private->entries_size; | |
1441 | tmp.valid_hooks = t->valid_hooks; | |
1442 | } else { | |
1443 | tmp.nentries = t->table->nentries; | |
1444 | tmp.entries_size = t->table->entries_size; | |
1445 | tmp.valid_hooks = t->table->valid_hooks; | |
1446 | } | |
57b47a53 | 1447 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1448 | if (copy_to_user(user, &tmp, *len) != 0){ |
1449 | BUGPRINT("c2u Didn't work\n"); | |
1450 | ret = -EFAULT; | |
1451 | break; | |
1452 | } | |
1453 | ret = 0; | |
1454 | break; | |
1455 | ||
1456 | case EBT_SO_GET_ENTRIES: | |
1457 | case EBT_SO_GET_INIT_ENTRIES: | |
1458 | ret = copy_everything_to_user(t, user, len, cmd); | |
57b47a53 | 1459 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1460 | break; |
1461 | ||
1462 | default: | |
57b47a53 | 1463 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1464 | ret = -EINVAL; |
1465 | } | |
1466 | ||
1467 | return ret; | |
1468 | } | |
1469 | ||
1470 | static struct nf_sockopt_ops ebt_sockopts = | |
74ca4e5a AM |
1471 | { |
1472 | .pf = PF_INET, | |
1473 | .set_optmin = EBT_BASE_CTL, | |
1474 | .set_optmax = EBT_SO_SET_MAX + 1, | |
1475 | .set = do_ebt_set_ctl, | |
1476 | .get_optmin = EBT_BASE_CTL, | |
1477 | .get_optmax = EBT_SO_GET_MAX + 1, | |
1478 | .get = do_ebt_get_ctl, | |
16fcec35 | 1479 | .owner = THIS_MODULE, |
1da177e4 LT |
1480 | }; |
1481 | ||
65b4b4e8 | 1482 | static int __init ebtables_init(void) |
1da177e4 LT |
1483 | { |
1484 | int ret; | |
1485 | ||
043ef46c JE |
1486 | ret = xt_register_target(&ebt_standard_target); |
1487 | if (ret < 0) | |
1da177e4 | 1488 | return ret; |
043ef46c JE |
1489 | ret = nf_register_sockopt(&ebt_sockopts); |
1490 | if (ret < 0) { | |
1491 | xt_unregister_target(&ebt_standard_target); | |
1492 | return ret; | |
1493 | } | |
1da177e4 | 1494 | |
a887c1c1 | 1495 | printk(KERN_INFO "Ebtables v2.0 registered\n"); |
1da177e4 LT |
1496 | return 0; |
1497 | } | |
1498 | ||
65b4b4e8 | 1499 | static void __exit ebtables_fini(void) |
1da177e4 LT |
1500 | { |
1501 | nf_unregister_sockopt(&ebt_sockopts); | |
043ef46c | 1502 | xt_unregister_target(&ebt_standard_target); |
a887c1c1 | 1503 | printk(KERN_INFO "Ebtables v2.0 unregistered\n"); |
1da177e4 LT |
1504 | } |
1505 | ||
1506 | EXPORT_SYMBOL(ebt_register_table); | |
1507 | EXPORT_SYMBOL(ebt_unregister_table); | |
1da177e4 | 1508 | EXPORT_SYMBOL(ebt_do_table); |
65b4b4e8 AM |
1509 | module_init(ebtables_init); |
1510 | module_exit(ebtables_fini); | |
1da177e4 | 1511 | MODULE_LICENSE("GPL"); |