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Commit | Line | Data |
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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 | */ | |
ff67e4e4 | 17 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
1da177e4 LT |
18 | #include <linux/kmod.h> |
19 | #include <linux/module.h> | |
20 | #include <linux/vmalloc.h> | |
18219d3f | 21 | #include <linux/netfilter/x_tables.h> |
1da177e4 LT |
22 | #include <linux/netfilter_bridge/ebtables.h> |
23 | #include <linux/spinlock.h> | |
df0933dc | 24 | #include <linux/mutex.h> |
1da177e4 LT |
25 | #include <asm/uaccess.h> |
26 | #include <linux/smp.h> | |
c8923c6b | 27 | #include <linux/cpumask.h> |
1da177e4 LT |
28 | #include <net/sock.h> |
29 | /* needed for logical [in,out]-dev filtering */ | |
30 | #include "../br_private.h" | |
31 | ||
1da177e4 | 32 | #define BUGPRINT(format, args...) printk("kernel msg: ebtables bug: please "\ |
9d6f229f | 33 | "report to author: "format, ## args) |
1da177e4 | 34 | /* #define BUGPRINT(format, args...) */ |
1da177e4 LT |
35 | |
36 | /* | |
37 | * Each cpu has its own set of counters, so there is no need for write_lock in | |
38 | * the softirq | |
39 | * For reading or updating the counters, the user context needs to | |
40 | * get a write_lock | |
41 | */ | |
42 | ||
43 | /* The size of each set of counters is altered to get cache alignment */ | |
44 | #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1)) | |
45 | #define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter))) | |
46 | #define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \ | |
47 | COUNTER_OFFSET(n) * cpu)) | |
48 | ||
49 | ||
50 | ||
57b47a53 | 51 | static DEFINE_MUTEX(ebt_mutex); |
1da177e4 | 52 | |
81e675c2 FW |
53 | #ifdef CONFIG_COMPAT |
54 | static void ebt_standard_compat_from_user(void *dst, const void *src) | |
55 | { | |
56 | int v = *(compat_int_t *)src; | |
57 | ||
58 | if (v >= 0) | |
59 | v += xt_compat_calc_jump(NFPROTO_BRIDGE, v); | |
60 | memcpy(dst, &v, sizeof(v)); | |
61 | } | |
62 | ||
63 | static int ebt_standard_compat_to_user(void __user *dst, const void *src) | |
64 | { | |
65 | compat_int_t cv = *(int *)src; | |
66 | ||
67 | if (cv >= 0) | |
68 | cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv); | |
69 | return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; | |
70 | } | |
71 | #endif | |
72 | ||
73 | ||
043ef46c | 74 | static struct xt_target ebt_standard_target = { |
001a18d3 JE |
75 | .name = "standard", |
76 | .revision = 0, | |
77 | .family = NFPROTO_BRIDGE, | |
043ef46c | 78 | .targetsize = sizeof(int), |
81e675c2 FW |
79 | #ifdef CONFIG_COMPAT |
80 | .compatsize = sizeof(compat_int_t), | |
81 | .compat_from_user = ebt_standard_compat_from_user, | |
82 | .compat_to_user = ebt_standard_compat_to_user, | |
83 | #endif | |
18219d3f | 84 | }; |
1da177e4 | 85 | |
7eb35586 JE |
86 | static inline int |
87 | ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb, | |
88 | struct xt_target_param *par) | |
1da177e4 | 89 | { |
7eb35586 JE |
90 | par->target = w->u.watcher; |
91 | par->targinfo = w->data; | |
92 | w->u.watcher->target(skb, par); | |
1da177e4 LT |
93 | /* watchers don't give a verdict */ |
94 | return 0; | |
95 | } | |
96 | ||
97 | static inline int ebt_do_match (struct ebt_entry_match *m, | |
f7108a20 | 98 | const struct sk_buff *skb, struct xt_match_param *par) |
1da177e4 | 99 | { |
f7108a20 JE |
100 | par->match = m->u.match; |
101 | par->matchinfo = m->data; | |
d61ba9fd | 102 | return m->u.match->match(skb, par) ? EBT_MATCH : EBT_NOMATCH; |
1da177e4 LT |
103 | } |
104 | ||
d5d1baa1 JE |
105 | static inline int |
106 | ebt_dev_check(const char *entry, const struct net_device *device) | |
1da177e4 LT |
107 | { |
108 | int i = 0; | |
f3d8b2e4 | 109 | const char *devname; |
1da177e4 LT |
110 | |
111 | if (*entry == '\0') | |
112 | return 0; | |
113 | if (!device) | |
114 | return 1; | |
f3d8b2e4 | 115 | devname = device->name; |
1da177e4 LT |
116 | /* 1 is the wildcard token */ |
117 | while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i]) | |
118 | i++; | |
119 | return (devname[i] != entry[i] && entry[i] != 1); | |
120 | } | |
121 | ||
122 | #define FWINV2(bool,invflg) ((bool) ^ !!(e->invflags & invflg)) | |
123 | /* process standard matches */ | |
d5d1baa1 JE |
124 | static inline int |
125 | ebt_basic_match(const struct ebt_entry *e, const struct ethhdr *h, | |
126 | const struct net_device *in, const struct net_device *out) | |
1da177e4 LT |
127 | { |
128 | int verdict, i; | |
129 | ||
130 | if (e->bitmask & EBT_802_3) { | |
131 | if (FWINV2(ntohs(h->h_proto) >= 1536, EBT_IPROTO)) | |
132 | return 1; | |
133 | } else if (!(e->bitmask & EBT_NOPROTO) && | |
134 | FWINV2(e->ethproto != h->h_proto, EBT_IPROTO)) | |
135 | return 1; | |
136 | ||
137 | if (FWINV2(ebt_dev_check(e->in, in), EBT_IIN)) | |
138 | return 1; | |
139 | if (FWINV2(ebt_dev_check(e->out, out), EBT_IOUT)) | |
140 | return 1; | |
141 | if ((!in || !in->br_port) ? 0 : FWINV2(ebt_dev_check( | |
142 | e->logical_in, in->br_port->br->dev), EBT_ILOGICALIN)) | |
143 | return 1; | |
144 | if ((!out || !out->br_port) ? 0 : FWINV2(ebt_dev_check( | |
145 | e->logical_out, out->br_port->br->dev), EBT_ILOGICALOUT)) | |
146 | return 1; | |
147 | ||
148 | if (e->bitmask & EBT_SOURCEMAC) { | |
149 | verdict = 0; | |
150 | for (i = 0; i < 6; i++) | |
151 | verdict |= (h->h_source[i] ^ e->sourcemac[i]) & | |
152 | e->sourcemsk[i]; | |
153 | if (FWINV2(verdict != 0, EBT_ISOURCE) ) | |
154 | return 1; | |
155 | } | |
156 | if (e->bitmask & EBT_DESTMAC) { | |
157 | verdict = 0; | |
158 | for (i = 0; i < 6; i++) | |
159 | verdict |= (h->h_dest[i] ^ e->destmac[i]) & | |
160 | e->destmsk[i]; | |
161 | if (FWINV2(verdict != 0, EBT_IDEST) ) | |
162 | return 1; | |
163 | } | |
164 | return 0; | |
165 | } | |
166 | ||
98e86403 JE |
167 | static inline __pure |
168 | struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry) | |
169 | { | |
170 | return (void *)entry + entry->next_offset; | |
171 | } | |
172 | ||
1da177e4 | 173 | /* Do some firewalling */ |
3db05fea | 174 | unsigned int ebt_do_table (unsigned int hook, struct sk_buff *skb, |
1da177e4 LT |
175 | const struct net_device *in, const struct net_device *out, |
176 | struct ebt_table *table) | |
177 | { | |
178 | int i, nentries; | |
179 | struct ebt_entry *point; | |
180 | struct ebt_counter *counter_base, *cb_base; | |
d5d1baa1 | 181 | const struct ebt_entry_target *t; |
1da177e4 LT |
182 | int verdict, sp = 0; |
183 | struct ebt_chainstack *cs; | |
184 | struct ebt_entries *chaininfo; | |
d5d1baa1 JE |
185 | const char *base; |
186 | const struct ebt_table_info *private; | |
5365f802 | 187 | bool hotdrop = false; |
f7108a20 | 188 | struct xt_match_param mtpar; |
7eb35586 | 189 | struct xt_target_param tgpar; |
f7108a20 | 190 | |
916a917d | 191 | mtpar.family = tgpar.family = NFPROTO_BRIDGE; |
7eb35586 JE |
192 | mtpar.in = tgpar.in = in; |
193 | mtpar.out = tgpar.out = out; | |
f7108a20 | 194 | mtpar.hotdrop = &hotdrop; |
a5e78820 | 195 | mtpar.hooknum = tgpar.hooknum = hook; |
1da177e4 LT |
196 | |
197 | read_lock_bh(&table->lock); | |
198 | private = table->private; | |
199 | cb_base = COUNTER_BASE(private->counters, private->nentries, | |
200 | smp_processor_id()); | |
201 | if (private->chainstack) | |
202 | cs = private->chainstack[smp_processor_id()]; | |
203 | else | |
204 | cs = NULL; | |
205 | chaininfo = private->hook_entry[hook]; | |
206 | nentries = private->hook_entry[hook]->nentries; | |
207 | point = (struct ebt_entry *)(private->hook_entry[hook]->data); | |
208 | counter_base = cb_base + private->hook_entry[hook]->counter_offset; | |
209 | /* base for chain jumps */ | |
210 | base = private->entries; | |
211 | i = 0; | |
212 | while (i < nentries) { | |
3db05fea | 213 | if (ebt_basic_match(point, eth_hdr(skb), in, out)) |
1da177e4 LT |
214 | goto letscontinue; |
215 | ||
f7108a20 | 216 | if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &mtpar) != 0) |
1da177e4 | 217 | goto letscontinue; |
5365f802 JE |
218 | if (hotdrop) { |
219 | read_unlock_bh(&table->lock); | |
220 | return NF_DROP; | |
221 | } | |
1da177e4 LT |
222 | |
223 | /* increase counter */ | |
224 | (*(counter_base + i)).pcnt++; | |
3db05fea | 225 | (*(counter_base + i)).bcnt += skb->len; |
1da177e4 LT |
226 | |
227 | /* these should only watch: not modify, nor tell us | |
228 | what to do with the packet */ | |
7eb35586 | 229 | EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &tgpar); |
1da177e4 LT |
230 | |
231 | t = (struct ebt_entry_target *) | |
232 | (((char *)point) + point->target_offset); | |
233 | /* standard target */ | |
234 | if (!t->u.target->target) | |
235 | verdict = ((struct ebt_standard_target *)t)->verdict; | |
7eb35586 JE |
236 | else { |
237 | tgpar.target = t->u.target; | |
238 | tgpar.targinfo = t->data; | |
239 | verdict = t->u.target->target(skb, &tgpar); | |
240 | } | |
1da177e4 LT |
241 | if (verdict == EBT_ACCEPT) { |
242 | read_unlock_bh(&table->lock); | |
243 | return NF_ACCEPT; | |
244 | } | |
245 | if (verdict == EBT_DROP) { | |
246 | read_unlock_bh(&table->lock); | |
247 | return NF_DROP; | |
248 | } | |
249 | if (verdict == EBT_RETURN) { | |
250 | letsreturn: | |
251 | #ifdef CONFIG_NETFILTER_DEBUG | |
252 | if (sp == 0) { | |
253 | BUGPRINT("RETURN on base chain"); | |
254 | /* act like this is EBT_CONTINUE */ | |
255 | goto letscontinue; | |
256 | } | |
257 | #endif | |
258 | sp--; | |
259 | /* put all the local variables right */ | |
260 | i = cs[sp].n; | |
261 | chaininfo = cs[sp].chaininfo; | |
262 | nentries = chaininfo->nentries; | |
263 | point = cs[sp].e; | |
264 | counter_base = cb_base + | |
265 | chaininfo->counter_offset; | |
266 | continue; | |
267 | } | |
268 | if (verdict == EBT_CONTINUE) | |
269 | goto letscontinue; | |
270 | #ifdef CONFIG_NETFILTER_DEBUG | |
271 | if (verdict < 0) { | |
272 | BUGPRINT("bogus standard verdict\n"); | |
273 | read_unlock_bh(&table->lock); | |
274 | return NF_DROP; | |
275 | } | |
276 | #endif | |
277 | /* jump to a udc */ | |
278 | cs[sp].n = i + 1; | |
279 | cs[sp].chaininfo = chaininfo; | |
98e86403 | 280 | cs[sp].e = ebt_next_entry(point); |
1da177e4 LT |
281 | i = 0; |
282 | chaininfo = (struct ebt_entries *) (base + verdict); | |
283 | #ifdef CONFIG_NETFILTER_DEBUG | |
284 | if (chaininfo->distinguisher) { | |
285 | BUGPRINT("jump to non-chain\n"); | |
286 | read_unlock_bh(&table->lock); | |
287 | return NF_DROP; | |
288 | } | |
289 | #endif | |
290 | nentries = chaininfo->nentries; | |
291 | point = (struct ebt_entry *)chaininfo->data; | |
292 | counter_base = cb_base + chaininfo->counter_offset; | |
293 | sp++; | |
294 | continue; | |
295 | letscontinue: | |
98e86403 | 296 | point = ebt_next_entry(point); |
1da177e4 LT |
297 | i++; |
298 | } | |
299 | ||
300 | /* I actually like this :) */ | |
301 | if (chaininfo->policy == EBT_RETURN) | |
302 | goto letsreturn; | |
303 | if (chaininfo->policy == EBT_ACCEPT) { | |
304 | read_unlock_bh(&table->lock); | |
305 | return NF_ACCEPT; | |
306 | } | |
307 | read_unlock_bh(&table->lock); | |
308 | return NF_DROP; | |
309 | } | |
310 | ||
311 | /* If it succeeds, returns element and locks mutex */ | |
312 | static inline void * | |
313 | find_inlist_lock_noload(struct list_head *head, const char *name, int *error, | |
57b47a53 | 314 | struct mutex *mutex) |
1da177e4 | 315 | { |
df0933dc PM |
316 | struct { |
317 | struct list_head list; | |
318 | char name[EBT_FUNCTION_MAXNAMELEN]; | |
319 | } *e; | |
1da177e4 | 320 | |
57b47a53 | 321 | *error = mutex_lock_interruptible(mutex); |
1da177e4 LT |
322 | if (*error != 0) |
323 | return NULL; | |
324 | ||
df0933dc PM |
325 | list_for_each_entry(e, head, list) { |
326 | if (strcmp(e->name, name) == 0) | |
327 | return e; | |
1da177e4 | 328 | } |
df0933dc PM |
329 | *error = -ENOENT; |
330 | mutex_unlock(mutex); | |
331 | return NULL; | |
1da177e4 LT |
332 | } |
333 | ||
1da177e4 LT |
334 | static void * |
335 | find_inlist_lock(struct list_head *head, const char *name, const char *prefix, | |
57b47a53 | 336 | int *error, struct mutex *mutex) |
1da177e4 | 337 | { |
95a5afca JB |
338 | return try_then_request_module( |
339 | find_inlist_lock_noload(head, name, error, mutex), | |
340 | "%s%s", prefix, name); | |
1da177e4 | 341 | } |
1da177e4 LT |
342 | |
343 | static inline struct ebt_table * | |
511061e2 AD |
344 | find_table_lock(struct net *net, const char *name, int *error, |
345 | struct mutex *mutex) | |
1da177e4 | 346 | { |
511061e2 AD |
347 | return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name, |
348 | "ebtable_", error, mutex); | |
1da177e4 LT |
349 | } |
350 | ||
1da177e4 | 351 | static inline int |
9b4fce7a JE |
352 | ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par, |
353 | unsigned int *cnt) | |
1da177e4 | 354 | { |
9b4fce7a | 355 | const struct ebt_entry *e = par->entryinfo; |
043ef46c | 356 | struct xt_match *match; |
14197d54 | 357 | size_t left = ((char *)e + e->watchers_offset) - (char *)m; |
1da177e4 LT |
358 | int ret; |
359 | ||
14197d54 AV |
360 | if (left < sizeof(struct ebt_entry_match) || |
361 | left - sizeof(struct ebt_entry_match) < m->match_size) | |
1da177e4 | 362 | return -EINVAL; |
043ef46c JE |
363 | |
364 | match = try_then_request_module(xt_find_match(NFPROTO_BRIDGE, | |
365 | m->u.name, 0), "ebt_%s", m->u.name); | |
366 | if (IS_ERR(match)) | |
367 | return PTR_ERR(match); | |
368 | if (match == NULL) | |
1da177e4 | 369 | return -ENOENT; |
043ef46c JE |
370 | m->u.match = match; |
371 | ||
9b4fce7a JE |
372 | par->match = match; |
373 | par->matchinfo = m->data; | |
916a917d | 374 | ret = xt_check_match(par, m->match_size, |
9b4fce7a | 375 | e->ethproto, e->invflags & EBT_IPROTO); |
043ef46c JE |
376 | if (ret < 0) { |
377 | module_put(match->me); | |
378 | return ret; | |
1da177e4 | 379 | } |
043ef46c | 380 | |
1da177e4 LT |
381 | (*cnt)++; |
382 | return 0; | |
383 | } | |
384 | ||
385 | static inline int | |
af5d6dc2 JE |
386 | ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par, |
387 | unsigned int *cnt) | |
1da177e4 | 388 | { |
af5d6dc2 | 389 | const struct ebt_entry *e = par->entryinfo; |
043ef46c | 390 | struct xt_target *watcher; |
14197d54 | 391 | size_t left = ((char *)e + e->target_offset) - (char *)w; |
1da177e4 LT |
392 | int ret; |
393 | ||
14197d54 AV |
394 | if (left < sizeof(struct ebt_entry_watcher) || |
395 | left - sizeof(struct ebt_entry_watcher) < w->watcher_size) | |
1da177e4 | 396 | return -EINVAL; |
043ef46c JE |
397 | |
398 | watcher = try_then_request_module( | |
399 | xt_find_target(NFPROTO_BRIDGE, w->u.name, 0), | |
400 | "ebt_%s", w->u.name); | |
401 | if (IS_ERR(watcher)) | |
402 | return PTR_ERR(watcher); | |
403 | if (watcher == NULL) | |
1da177e4 | 404 | return -ENOENT; |
043ef46c JE |
405 | w->u.watcher = watcher; |
406 | ||
af5d6dc2 JE |
407 | par->target = watcher; |
408 | par->targinfo = w->data; | |
916a917d | 409 | ret = xt_check_target(par, w->watcher_size, |
af5d6dc2 | 410 | e->ethproto, e->invflags & EBT_IPROTO); |
043ef46c JE |
411 | if (ret < 0) { |
412 | module_put(watcher->me); | |
413 | return ret; | |
1da177e4 | 414 | } |
043ef46c | 415 | |
1da177e4 LT |
416 | (*cnt)++; |
417 | return 0; | |
418 | } | |
419 | ||
d5d1baa1 | 420 | static int ebt_verify_pointers(const struct ebt_replace *repl, |
70fe9af4 | 421 | struct ebt_table_info *newinfo) |
1da177e4 | 422 | { |
70fe9af4 AV |
423 | unsigned int limit = repl->entries_size; |
424 | unsigned int valid_hooks = repl->valid_hooks; | |
425 | unsigned int offset = 0; | |
1da177e4 LT |
426 | int i; |
427 | ||
e4fd77de AV |
428 | for (i = 0; i < NF_BR_NUMHOOKS; i++) |
429 | newinfo->hook_entry[i] = NULL; | |
430 | ||
431 | newinfo->entries_size = repl->entries_size; | |
432 | newinfo->nentries = repl->nentries; | |
433 | ||
70fe9af4 AV |
434 | while (offset < limit) { |
435 | size_t left = limit - offset; | |
436 | struct ebt_entry *e = (void *)newinfo->entries + offset; | |
bb2ef25c | 437 | |
70fe9af4 | 438 | if (left < sizeof(unsigned int)) |
1da177e4 | 439 | break; |
70fe9af4 AV |
440 | |
441 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
442 | if ((valid_hooks & (1 << i)) == 0) | |
443 | continue; | |
1e419cd9 AV |
444 | if ((char __user *)repl->hook_entry[i] == |
445 | repl->entries + offset) | |
70fe9af4 AV |
446 | break; |
447 | } | |
448 | ||
449 | if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) { | |
450 | if (e->bitmask != 0) { | |
451 | /* we make userspace set this right, | |
452 | so there is no misunderstanding */ | |
453 | BUGPRINT("EBT_ENTRY_OR_ENTRIES shouldn't be set " | |
454 | "in distinguisher\n"); | |
455 | return -EINVAL; | |
456 | } | |
457 | if (i != NF_BR_NUMHOOKS) | |
458 | newinfo->hook_entry[i] = (struct ebt_entries *)e; | |
459 | if (left < sizeof(struct ebt_entries)) | |
460 | break; | |
461 | offset += sizeof(struct ebt_entries); | |
462 | } else { | |
463 | if (left < sizeof(struct ebt_entry)) | |
464 | break; | |
465 | if (left < e->next_offset) | |
466 | break; | |
1756de26 FW |
467 | if (e->next_offset < sizeof(struct ebt_entry)) |
468 | return -EINVAL; | |
70fe9af4 | 469 | offset += e->next_offset; |
1da177e4 | 470 | } |
22b440bf | 471 | } |
70fe9af4 AV |
472 | if (offset != limit) { |
473 | BUGPRINT("entries_size too small\n"); | |
474 | return -EINVAL; | |
475 | } | |
e4fd77de AV |
476 | |
477 | /* check if all valid hooks have a chain */ | |
478 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
479 | if (!newinfo->hook_entry[i] && | |
480 | (valid_hooks & (1 << i))) { | |
481 | BUGPRINT("Valid hook without chain\n"); | |
482 | return -EINVAL; | |
483 | } | |
484 | } | |
22b440bf | 485 | return 0; |
22b440bf AV |
486 | } |
487 | ||
488 | /* | |
489 | * this one is very careful, as it is the first function | |
490 | * to parse the userspace data | |
491 | */ | |
492 | static inline int | |
d5d1baa1 JE |
493 | ebt_check_entry_size_and_hooks(const struct ebt_entry *e, |
494 | const struct ebt_table_info *newinfo, | |
0e795531 AV |
495 | unsigned int *n, unsigned int *cnt, |
496 | unsigned int *totalcnt, unsigned int *udc_cnt) | |
22b440bf | 497 | { |
22b440bf AV |
498 | int i; |
499 | ||
500 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
0e795531 | 501 | if ((void *)e == (void *)newinfo->hook_entry[i]) |
22b440bf AV |
502 | break; |
503 | } | |
504 | /* beginning of a new chain | |
505 | if i == NF_BR_NUMHOOKS it must be a user defined chain */ | |
506 | if (i != NF_BR_NUMHOOKS || !e->bitmask) { | |
1da177e4 LT |
507 | /* this checks if the previous chain has as many entries |
508 | as it said it has */ | |
509 | if (*n != *cnt) { | |
510 | BUGPRINT("nentries does not equal the nr of entries " | |
9d6f229f | 511 | "in the chain\n"); |
1da177e4 LT |
512 | return -EINVAL; |
513 | } | |
1da177e4 LT |
514 | if (((struct ebt_entries *)e)->policy != EBT_DROP && |
515 | ((struct ebt_entries *)e)->policy != EBT_ACCEPT) { | |
516 | /* only RETURN from udc */ | |
517 | if (i != NF_BR_NUMHOOKS || | |
518 | ((struct ebt_entries *)e)->policy != EBT_RETURN) { | |
519 | BUGPRINT("bad policy\n"); | |
520 | return -EINVAL; | |
521 | } | |
522 | } | |
523 | if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */ | |
524 | (*udc_cnt)++; | |
1da177e4 LT |
525 | if (((struct ebt_entries *)e)->counter_offset != *totalcnt) { |
526 | BUGPRINT("counter_offset != totalcnt"); | |
527 | return -EINVAL; | |
528 | } | |
529 | *n = ((struct ebt_entries *)e)->nentries; | |
530 | *cnt = 0; | |
531 | return 0; | |
532 | } | |
533 | /* a plain old entry, heh */ | |
534 | if (sizeof(struct ebt_entry) > e->watchers_offset || | |
535 | e->watchers_offset > e->target_offset || | |
536 | e->target_offset >= e->next_offset) { | |
537 | BUGPRINT("entry offsets not in right order\n"); | |
538 | return -EINVAL; | |
539 | } | |
540 | /* this is not checked anywhere else */ | |
541 | if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target)) { | |
542 | BUGPRINT("target size too small\n"); | |
543 | return -EINVAL; | |
544 | } | |
1da177e4 LT |
545 | (*cnt)++; |
546 | (*totalcnt)++; | |
547 | return 0; | |
548 | } | |
549 | ||
550 | struct ebt_cl_stack | |
551 | { | |
552 | struct ebt_chainstack cs; | |
553 | int from; | |
554 | unsigned int hookmask; | |
555 | }; | |
556 | ||
557 | /* | |
558 | * we need these positions to check that the jumps to a different part of the | |
559 | * entries is a jump to the beginning of a new chain. | |
560 | */ | |
561 | static inline int | |
562 | ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo, | |
177abc34 | 563 | unsigned int *n, struct ebt_cl_stack *udc) |
1da177e4 LT |
564 | { |
565 | int i; | |
566 | ||
567 | /* we're only interested in chain starts */ | |
40642f95 | 568 | if (e->bitmask) |
1da177e4 LT |
569 | return 0; |
570 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
1da177e4 LT |
571 | if (newinfo->hook_entry[i] == (struct ebt_entries *)e) |
572 | break; | |
573 | } | |
574 | /* only care about udc */ | |
575 | if (i != NF_BR_NUMHOOKS) | |
576 | return 0; | |
577 | ||
578 | udc[*n].cs.chaininfo = (struct ebt_entries *)e; | |
579 | /* these initialisations are depended on later in check_chainloops() */ | |
580 | udc[*n].cs.n = 0; | |
581 | udc[*n].hookmask = 0; | |
582 | ||
583 | (*n)++; | |
584 | return 0; | |
585 | } | |
586 | ||
587 | static inline int | |
f54e9367 | 588 | ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i) |
1da177e4 | 589 | { |
6be3d859 JE |
590 | struct xt_mtdtor_param par; |
591 | ||
1da177e4 LT |
592 | if (i && (*i)-- == 0) |
593 | return 1; | |
1da177e4 | 594 | |
f54e9367 | 595 | par.net = net; |
6be3d859 JE |
596 | par.match = m->u.match; |
597 | par.matchinfo = m->data; | |
916a917d | 598 | par.family = NFPROTO_BRIDGE; |
6be3d859 JE |
599 | if (par.match->destroy != NULL) |
600 | par.match->destroy(&par); | |
601 | module_put(par.match->me); | |
1da177e4 LT |
602 | return 0; |
603 | } | |
604 | ||
605 | static inline int | |
add67461 | 606 | ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i) |
1da177e4 | 607 | { |
a2df1648 JE |
608 | struct xt_tgdtor_param par; |
609 | ||
1da177e4 LT |
610 | if (i && (*i)-- == 0) |
611 | return 1; | |
1da177e4 | 612 | |
add67461 | 613 | par.net = net; |
a2df1648 JE |
614 | par.target = w->u.watcher; |
615 | par.targinfo = w->data; | |
916a917d | 616 | par.family = NFPROTO_BRIDGE; |
a2df1648 JE |
617 | if (par.target->destroy != NULL) |
618 | par.target->destroy(&par); | |
619 | module_put(par.target->me); | |
1da177e4 LT |
620 | return 0; |
621 | } | |
622 | ||
623 | static inline int | |
f54e9367 | 624 | ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt) |
1da177e4 | 625 | { |
a2df1648 | 626 | struct xt_tgdtor_param par; |
1da177e4 LT |
627 | struct ebt_entry_target *t; |
628 | ||
40642f95 | 629 | if (e->bitmask == 0) |
1da177e4 LT |
630 | return 0; |
631 | /* we're done */ | |
632 | if (cnt && (*cnt)-- == 0) | |
633 | return 1; | |
add67461 | 634 | EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL); |
f54e9367 | 635 | EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL); |
1da177e4 | 636 | t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); |
1da177e4 | 637 | |
add67461 | 638 | par.net = net; |
a2df1648 JE |
639 | par.target = t->u.target; |
640 | par.targinfo = t->data; | |
916a917d | 641 | par.family = NFPROTO_BRIDGE; |
a2df1648 JE |
642 | if (par.target->destroy != NULL) |
643 | par.target->destroy(&par); | |
644 | module_put(par.target->me); | |
1da177e4 LT |
645 | return 0; |
646 | } | |
647 | ||
648 | static inline int | |
d5d1baa1 JE |
649 | ebt_check_entry(struct ebt_entry *e, struct net *net, |
650 | const struct ebt_table_info *newinfo, | |
f7da79d9 | 651 | const char *name, unsigned int *cnt, |
1da177e4 LT |
652 | struct ebt_cl_stack *cl_s, unsigned int udc_cnt) |
653 | { | |
654 | struct ebt_entry_target *t; | |
043ef46c | 655 | struct xt_target *target; |
1da177e4 | 656 | unsigned int i, j, hook = 0, hookmask = 0; |
44f9a2fd | 657 | size_t gap; |
1da177e4 | 658 | int ret; |
6be3d859 | 659 | struct xt_mtchk_param mtpar; |
af5d6dc2 | 660 | struct xt_tgchk_param tgpar; |
1da177e4 LT |
661 | |
662 | /* don't mess with the struct ebt_entries */ | |
40642f95 | 663 | if (e->bitmask == 0) |
1da177e4 LT |
664 | return 0; |
665 | ||
666 | if (e->bitmask & ~EBT_F_MASK) { | |
667 | BUGPRINT("Unknown flag for bitmask\n"); | |
668 | return -EINVAL; | |
669 | } | |
670 | if (e->invflags & ~EBT_INV_MASK) { | |
671 | BUGPRINT("Unknown flag for inv bitmask\n"); | |
672 | return -EINVAL; | |
673 | } | |
674 | if ( (e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3) ) { | |
675 | BUGPRINT("NOPROTO & 802_3 not allowed\n"); | |
676 | return -EINVAL; | |
677 | } | |
678 | /* what hook do we belong to? */ | |
679 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
f7da79d9 | 680 | if (!newinfo->hook_entry[i]) |
1da177e4 LT |
681 | continue; |
682 | if ((char *)newinfo->hook_entry[i] < (char *)e) | |
683 | hook = i; | |
684 | else | |
685 | break; | |
686 | } | |
687 | /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on | |
688 | a base chain */ | |
689 | if (i < NF_BR_NUMHOOKS) | |
690 | hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS); | |
691 | else { | |
692 | for (i = 0; i < udc_cnt; i++) | |
693 | if ((char *)(cl_s[i].cs.chaininfo) > (char *)e) | |
694 | break; | |
695 | if (i == 0) | |
696 | hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS); | |
697 | else | |
698 | hookmask = cl_s[i - 1].hookmask; | |
699 | } | |
700 | i = 0; | |
9b4fce7a | 701 | |
add67461 | 702 | mtpar.net = tgpar.net = net; |
af5d6dc2 JE |
703 | mtpar.table = tgpar.table = name; |
704 | mtpar.entryinfo = tgpar.entryinfo = e; | |
705 | mtpar.hook_mask = tgpar.hook_mask = hookmask; | |
916a917d | 706 | mtpar.family = tgpar.family = NFPROTO_BRIDGE; |
6be3d859 | 707 | ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i); |
1da177e4 LT |
708 | if (ret != 0) |
709 | goto cleanup_matches; | |
710 | j = 0; | |
af5d6dc2 | 711 | ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j); |
1da177e4 LT |
712 | if (ret != 0) |
713 | goto cleanup_watchers; | |
714 | t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); | |
44f9a2fd | 715 | gap = e->next_offset - e->target_offset; |
1da177e4 | 716 | |
043ef46c JE |
717 | target = try_then_request_module( |
718 | xt_find_target(NFPROTO_BRIDGE, t->u.name, 0), | |
719 | "ebt_%s", t->u.name); | |
720 | if (IS_ERR(target)) { | |
721 | ret = PTR_ERR(target); | |
001a18d3 | 722 | goto cleanup_watchers; |
043ef46c JE |
723 | } else if (target == NULL) { |
724 | ret = -ENOENT; | |
001a18d3 JE |
725 | goto cleanup_watchers; |
726 | } | |
727 | ||
1da177e4 LT |
728 | t->u.target = target; |
729 | if (t->u.target == &ebt_standard_target) { | |
14197d54 | 730 | if (gap < sizeof(struct ebt_standard_target)) { |
1da177e4 LT |
731 | BUGPRINT("Standard target size too big\n"); |
732 | ret = -EFAULT; | |
733 | goto cleanup_watchers; | |
734 | } | |
735 | if (((struct ebt_standard_target *)t)->verdict < | |
736 | -NUM_STANDARD_TARGETS) { | |
737 | BUGPRINT("Invalid standard target\n"); | |
738 | ret = -EFAULT; | |
739 | goto cleanup_watchers; | |
740 | } | |
18219d3f JE |
741 | } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) { |
742 | module_put(t->u.target->me); | |
743 | ret = -EFAULT; | |
744 | goto cleanup_watchers; | |
043ef46c JE |
745 | } |
746 | ||
af5d6dc2 JE |
747 | tgpar.target = target; |
748 | tgpar.targinfo = t->data; | |
916a917d | 749 | ret = xt_check_target(&tgpar, t->target_size, |
af5d6dc2 | 750 | e->ethproto, e->invflags & EBT_IPROTO); |
043ef46c JE |
751 | if (ret < 0) { |
752 | module_put(target->me); | |
18219d3f | 753 | goto cleanup_watchers; |
1da177e4 LT |
754 | } |
755 | (*cnt)++; | |
756 | return 0; | |
757 | cleanup_watchers: | |
add67461 | 758 | EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j); |
1da177e4 | 759 | cleanup_matches: |
f54e9367 | 760 | EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i); |
1da177e4 LT |
761 | return ret; |
762 | } | |
763 | ||
764 | /* | |
765 | * checks for loops and sets the hook mask for udc | |
766 | * the hook mask for udc tells us from which base chains the udc can be | |
767 | * accessed. This mask is a parameter to the check() functions of the extensions | |
768 | */ | |
d5d1baa1 | 769 | static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s, |
1da177e4 LT |
770 | unsigned int udc_cnt, unsigned int hooknr, char *base) |
771 | { | |
772 | int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict; | |
d5d1baa1 JE |
773 | const struct ebt_entry *e = (struct ebt_entry *)chain->data; |
774 | const struct ebt_entry_target *t; | |
1da177e4 LT |
775 | |
776 | while (pos < nentries || chain_nr != -1) { | |
777 | /* end of udc, go back one 'recursion' step */ | |
778 | if (pos == nentries) { | |
779 | /* put back values of the time when this chain was called */ | |
780 | e = cl_s[chain_nr].cs.e; | |
781 | if (cl_s[chain_nr].from != -1) | |
782 | nentries = | |
783 | cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries; | |
784 | else | |
785 | nentries = chain->nentries; | |
786 | pos = cl_s[chain_nr].cs.n; | |
787 | /* make sure we won't see a loop that isn't one */ | |
788 | cl_s[chain_nr].cs.n = 0; | |
789 | chain_nr = cl_s[chain_nr].from; | |
790 | if (pos == nentries) | |
791 | continue; | |
792 | } | |
793 | t = (struct ebt_entry_target *) | |
794 | (((char *)e) + e->target_offset); | |
795 | if (strcmp(t->u.name, EBT_STANDARD_TARGET)) | |
796 | goto letscontinue; | |
797 | if (e->target_offset + sizeof(struct ebt_standard_target) > | |
798 | e->next_offset) { | |
799 | BUGPRINT("Standard target size too big\n"); | |
800 | return -1; | |
801 | } | |
802 | verdict = ((struct ebt_standard_target *)t)->verdict; | |
803 | if (verdict >= 0) { /* jump to another chain */ | |
804 | struct ebt_entries *hlp2 = | |
805 | (struct ebt_entries *)(base + verdict); | |
806 | for (i = 0; i < udc_cnt; i++) | |
807 | if (hlp2 == cl_s[i].cs.chaininfo) | |
808 | break; | |
809 | /* bad destination or loop */ | |
810 | if (i == udc_cnt) { | |
811 | BUGPRINT("bad destination\n"); | |
812 | return -1; | |
813 | } | |
814 | if (cl_s[i].cs.n) { | |
815 | BUGPRINT("loop\n"); | |
816 | return -1; | |
817 | } | |
98a0824a AV |
818 | if (cl_s[i].hookmask & (1 << hooknr)) |
819 | goto letscontinue; | |
820 | /* this can't be 0, so the loop test is correct */ | |
1da177e4 LT |
821 | cl_s[i].cs.n = pos + 1; |
822 | pos = 0; | |
98e86403 | 823 | cl_s[i].cs.e = ebt_next_entry(e); |
1da177e4 LT |
824 | e = (struct ebt_entry *)(hlp2->data); |
825 | nentries = hlp2->nentries; | |
826 | cl_s[i].from = chain_nr; | |
827 | chain_nr = i; | |
828 | /* this udc is accessible from the base chain for hooknr */ | |
829 | cl_s[i].hookmask |= (1 << hooknr); | |
830 | continue; | |
831 | } | |
832 | letscontinue: | |
98e86403 | 833 | e = ebt_next_entry(e); |
1da177e4 LT |
834 | pos++; |
835 | } | |
836 | return 0; | |
837 | } | |
838 | ||
839 | /* do the parsing of the table/chains/entries/matches/watchers/targets, heh */ | |
d5d1baa1 | 840 | static int translate_table(struct net *net, const char *name, |
a83d8e8d | 841 | struct ebt_table_info *newinfo) |
1da177e4 LT |
842 | { |
843 | unsigned int i, j, k, udc_cnt; | |
844 | int ret; | |
845 | struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */ | |
846 | ||
847 | i = 0; | |
1f072c96 | 848 | while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i]) |
1da177e4 LT |
849 | i++; |
850 | if (i == NF_BR_NUMHOOKS) { | |
851 | BUGPRINT("No valid hooks specified\n"); | |
852 | return -EINVAL; | |
853 | } | |
1f072c96 | 854 | if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) { |
1da177e4 LT |
855 | BUGPRINT("Chains don't start at beginning\n"); |
856 | return -EINVAL; | |
857 | } | |
858 | /* make sure chains are ordered after each other in same order | |
859 | as their corresponding hooks */ | |
860 | for (j = i + 1; j < NF_BR_NUMHOOKS; j++) { | |
1f072c96 | 861 | if (!newinfo->hook_entry[j]) |
1da177e4 | 862 | continue; |
1f072c96 | 863 | if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) { |
1da177e4 LT |
864 | BUGPRINT("Hook order must be followed\n"); |
865 | return -EINVAL; | |
866 | } | |
867 | i = j; | |
868 | } | |
869 | ||
1da177e4 LT |
870 | /* do some early checkings and initialize some things */ |
871 | i = 0; /* holds the expected nr. of entries for the chain */ | |
872 | j = 0; /* holds the up to now counted entries for the chain */ | |
873 | k = 0; /* holds the total nr. of entries, should equal | |
9d6f229f | 874 | newinfo->nentries afterwards */ |
1da177e4 LT |
875 | udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */ |
876 | ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
0e795531 AV |
877 | ebt_check_entry_size_and_hooks, newinfo, |
878 | &i, &j, &k, &udc_cnt); | |
1da177e4 LT |
879 | |
880 | if (ret != 0) | |
881 | return ret; | |
882 | ||
883 | if (i != j) { | |
884 | BUGPRINT("nentries does not equal the nr of entries in the " | |
9d6f229f | 885 | "(last) chain\n"); |
1da177e4 LT |
886 | return -EINVAL; |
887 | } | |
888 | if (k != newinfo->nentries) { | |
889 | BUGPRINT("Total nentries is wrong\n"); | |
890 | return -EINVAL; | |
891 | } | |
892 | ||
1da177e4 LT |
893 | /* get the location of the udc, put them in an array |
894 | while we're at it, allocate the chainstack */ | |
895 | if (udc_cnt) { | |
896 | /* this will get free'd in do_replace()/ebt_register_table() | |
897 | if an error occurs */ | |
7ad4d2f6 | 898 | newinfo->chainstack = |
53b8a315 | 899 | vmalloc(nr_cpu_ids * sizeof(*(newinfo->chainstack))); |
1da177e4 LT |
900 | if (!newinfo->chainstack) |
901 | return -ENOMEM; | |
6f912042 | 902 | for_each_possible_cpu(i) { |
1da177e4 | 903 | newinfo->chainstack[i] = |
18bc89aa | 904 | vmalloc(udc_cnt * sizeof(*(newinfo->chainstack[0]))); |
1da177e4 LT |
905 | if (!newinfo->chainstack[i]) { |
906 | while (i) | |
907 | vfree(newinfo->chainstack[--i]); | |
908 | vfree(newinfo->chainstack); | |
909 | newinfo->chainstack = NULL; | |
910 | return -ENOMEM; | |
911 | } | |
912 | } | |
913 | ||
18bc89aa | 914 | cl_s = vmalloc(udc_cnt * sizeof(*cl_s)); |
1da177e4 LT |
915 | if (!cl_s) |
916 | return -ENOMEM; | |
917 | i = 0; /* the i'th udc */ | |
918 | EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
177abc34 | 919 | ebt_get_udc_positions, newinfo, &i, cl_s); |
1da177e4 LT |
920 | /* sanity check */ |
921 | if (i != udc_cnt) { | |
922 | BUGPRINT("i != udc_cnt\n"); | |
923 | vfree(cl_s); | |
924 | return -EFAULT; | |
925 | } | |
926 | } | |
927 | ||
928 | /* Check for loops */ | |
929 | for (i = 0; i < NF_BR_NUMHOOKS; i++) | |
1f072c96 | 930 | if (newinfo->hook_entry[i]) |
1da177e4 LT |
931 | if (check_chainloops(newinfo->hook_entry[i], |
932 | cl_s, udc_cnt, i, newinfo->entries)) { | |
68d31872 | 933 | vfree(cl_s); |
1da177e4 LT |
934 | return -EINVAL; |
935 | } | |
936 | ||
96de0e25 | 937 | /* we now know the following (along with E=mc²): |
1da177e4 LT |
938 | - the nr of entries in each chain is right |
939 | - the size of the allocated space is right | |
940 | - all valid hooks have a corresponding chain | |
941 | - there are no loops | |
942 | - wrong data can still be on the level of a single entry | |
943 | - could be there are jumps to places that are not the | |
944 | beginning of a chain. This can only occur in chains that | |
945 | are not accessible from any base chains, so we don't care. */ | |
946 | ||
947 | /* used to know what we need to clean up if something goes wrong */ | |
948 | i = 0; | |
949 | ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
a83d8e8d | 950 | ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt); |
1da177e4 LT |
951 | if (ret != 0) { |
952 | EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
f54e9367 | 953 | ebt_cleanup_entry, net, &i); |
1da177e4 | 954 | } |
68d31872 | 955 | vfree(cl_s); |
1da177e4 LT |
956 | return ret; |
957 | } | |
958 | ||
959 | /* called under write_lock */ | |
d5d1baa1 | 960 | static void get_counters(const struct ebt_counter *oldcounters, |
1da177e4 LT |
961 | struct ebt_counter *counters, unsigned int nentries) |
962 | { | |
963 | int i, cpu; | |
964 | struct ebt_counter *counter_base; | |
965 | ||
966 | /* counters of cpu 0 */ | |
967 | memcpy(counters, oldcounters, | |
c8923c6b DM |
968 | sizeof(struct ebt_counter) * nentries); |
969 | ||
1da177e4 | 970 | /* add other counters to those of cpu 0 */ |
6f912042 | 971 | for_each_possible_cpu(cpu) { |
c8923c6b DM |
972 | if (cpu == 0) |
973 | continue; | |
1da177e4 LT |
974 | counter_base = COUNTER_BASE(oldcounters, nentries, cpu); |
975 | for (i = 0; i < nentries; i++) { | |
976 | counters[i].pcnt += counter_base[i].pcnt; | |
977 | counters[i].bcnt += counter_base[i].bcnt; | |
978 | } | |
979 | } | |
980 | } | |
981 | ||
e788759f FW |
982 | static int do_replace_finish(struct net *net, struct ebt_replace *repl, |
983 | struct ebt_table_info *newinfo) | |
1da177e4 | 984 | { |
e788759f | 985 | int ret, i; |
1da177e4 LT |
986 | struct ebt_counter *counterstmp = NULL; |
987 | /* used to be able to unlock earlier */ | |
988 | struct ebt_table_info *table; | |
e788759f | 989 | struct ebt_table *t; |
1da177e4 LT |
990 | |
991 | /* the user wants counters back | |
992 | the check on the size is done later, when we have the lock */ | |
e788759f FW |
993 | if (repl->num_counters) { |
994 | unsigned long size = repl->num_counters * sizeof(*counterstmp); | |
995 | counterstmp = vmalloc(size); | |
996 | if (!counterstmp) | |
997 | return -ENOMEM; | |
1da177e4 | 998 | } |
1da177e4 | 999 | |
1da177e4 | 1000 | newinfo->chainstack = NULL; |
e788759f | 1001 | ret = ebt_verify_pointers(repl, newinfo); |
1bc2326c AV |
1002 | if (ret != 0) |
1003 | goto free_counterstmp; | |
1004 | ||
e788759f | 1005 | ret = translate_table(net, repl->name, newinfo); |
1da177e4 LT |
1006 | |
1007 | if (ret != 0) | |
1008 | goto free_counterstmp; | |
1009 | ||
e788759f | 1010 | t = find_table_lock(net, repl->name, &ret, &ebt_mutex); |
1da177e4 LT |
1011 | if (!t) { |
1012 | ret = -ENOENT; | |
1013 | goto free_iterate; | |
1014 | } | |
1015 | ||
1016 | /* the table doesn't like it */ | |
e788759f | 1017 | if (t->check && (ret = t->check(newinfo, repl->valid_hooks))) |
1da177e4 LT |
1018 | goto free_unlock; |
1019 | ||
e788759f | 1020 | if (repl->num_counters && repl->num_counters != t->private->nentries) { |
1da177e4 LT |
1021 | BUGPRINT("Wrong nr. of counters requested\n"); |
1022 | ret = -EINVAL; | |
1023 | goto free_unlock; | |
1024 | } | |
1025 | ||
1026 | /* we have the mutex lock, so no danger in reading this pointer */ | |
1027 | table = t->private; | |
1028 | /* make sure the table can only be rmmod'ed if it contains no rules */ | |
1029 | if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) { | |
1030 | ret = -ENOENT; | |
1031 | goto free_unlock; | |
1032 | } else if (table->nentries && !newinfo->nentries) | |
1033 | module_put(t->me); | |
1034 | /* we need an atomic snapshot of the counters */ | |
1035 | write_lock_bh(&t->lock); | |
e788759f | 1036 | if (repl->num_counters) |
1da177e4 LT |
1037 | get_counters(t->private->counters, counterstmp, |
1038 | t->private->nentries); | |
1039 | ||
1040 | t->private = newinfo; | |
1041 | write_unlock_bh(&t->lock); | |
57b47a53 | 1042 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1043 | /* so, a user can change the chains while having messed up her counter |
1044 | allocation. Only reason why this is done is because this way the lock | |
1045 | is held only once, while this doesn't bring the kernel into a | |
1046 | dangerous state. */ | |
e788759f FW |
1047 | if (repl->num_counters && |
1048 | copy_to_user(repl->counters, counterstmp, | |
1049 | repl->num_counters * sizeof(struct ebt_counter))) { | |
1da177e4 LT |
1050 | ret = -EFAULT; |
1051 | } | |
1052 | else | |
1053 | ret = 0; | |
1054 | ||
1055 | /* decrease module count and free resources */ | |
1056 | EBT_ENTRY_ITERATE(table->entries, table->entries_size, | |
f54e9367 | 1057 | ebt_cleanup_entry, net, NULL); |
1da177e4 LT |
1058 | |
1059 | vfree(table->entries); | |
1060 | if (table->chainstack) { | |
6f912042 | 1061 | for_each_possible_cpu(i) |
1da177e4 LT |
1062 | vfree(table->chainstack[i]); |
1063 | vfree(table->chainstack); | |
1064 | } | |
1065 | vfree(table); | |
1066 | ||
68d31872 | 1067 | vfree(counterstmp); |
1da177e4 LT |
1068 | return ret; |
1069 | ||
1070 | free_unlock: | |
57b47a53 | 1071 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1072 | free_iterate: |
1073 | EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, | |
f54e9367 | 1074 | ebt_cleanup_entry, net, NULL); |
1da177e4 | 1075 | free_counterstmp: |
68d31872 | 1076 | vfree(counterstmp); |
1da177e4 LT |
1077 | /* can be initialized in translate_table() */ |
1078 | if (newinfo->chainstack) { | |
6f912042 | 1079 | for_each_possible_cpu(i) |
1da177e4 LT |
1080 | vfree(newinfo->chainstack[i]); |
1081 | vfree(newinfo->chainstack); | |
1082 | } | |
e788759f FW |
1083 | return ret; |
1084 | } | |
1085 | ||
1086 | /* replace the table */ | |
1087 | static int do_replace(struct net *net, const void __user *user, | |
1088 | unsigned int len) | |
1089 | { | |
1090 | int ret, countersize; | |
1091 | struct ebt_table_info *newinfo; | |
1092 | struct ebt_replace tmp; | |
1093 | ||
1094 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) | |
1095 | return -EFAULT; | |
1096 | ||
1097 | if (len != sizeof(tmp) + tmp.entries_size) { | |
1098 | BUGPRINT("Wrong len argument\n"); | |
1099 | return -EINVAL; | |
1100 | } | |
1101 | ||
1102 | if (tmp.entries_size == 0) { | |
1103 | BUGPRINT("Entries_size never zero\n"); | |
1104 | return -EINVAL; | |
1105 | } | |
1106 | /* overflow check */ | |
1107 | if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) / | |
1108 | NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter)) | |
1109 | return -ENOMEM; | |
1110 | if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) | |
1111 | return -ENOMEM; | |
1112 | ||
1113 | countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids; | |
1114 | newinfo = vmalloc(sizeof(*newinfo) + countersize); | |
1115 | if (!newinfo) | |
1116 | return -ENOMEM; | |
1117 | ||
1118 | if (countersize) | |
1119 | memset(newinfo->counters, 0, countersize); | |
1120 | ||
1121 | newinfo->entries = vmalloc(tmp.entries_size); | |
1122 | if (!newinfo->entries) { | |
1123 | ret = -ENOMEM; | |
1124 | goto free_newinfo; | |
1125 | } | |
1126 | if (copy_from_user( | |
1127 | newinfo->entries, tmp.entries, tmp.entries_size) != 0) { | |
1128 | BUGPRINT("Couldn't copy entries from userspace\n"); | |
1129 | ret = -EFAULT; | |
1130 | goto free_entries; | |
1131 | } | |
1132 | ||
1133 | ret = do_replace_finish(net, &tmp, newinfo); | |
1134 | if (ret == 0) | |
1135 | return ret; | |
1da177e4 | 1136 | free_entries: |
68d31872 | 1137 | vfree(newinfo->entries); |
1da177e4 | 1138 | free_newinfo: |
68d31872 | 1139 | vfree(newinfo); |
1da177e4 LT |
1140 | return ret; |
1141 | } | |
1142 | ||
35aad0ff JE |
1143 | struct ebt_table * |
1144 | ebt_register_table(struct net *net, const struct ebt_table *input_table) | |
1da177e4 LT |
1145 | { |
1146 | struct ebt_table_info *newinfo; | |
35aad0ff | 1147 | struct ebt_table *t, *table; |
1e419cd9 | 1148 | struct ebt_replace_kernel *repl; |
1da177e4 | 1149 | int ret, i, countersize; |
df07a81e | 1150 | void *p; |
1da177e4 | 1151 | |
35aad0ff JE |
1152 | if (input_table == NULL || (repl = input_table->table) == NULL || |
1153 | repl->entries == 0 || repl->entries_size == 0 || | |
1154 | repl->counters != NULL || input_table->private != NULL) { | |
1da177e4 | 1155 | BUGPRINT("Bad table data for ebt_register_table!!!\n"); |
6beceee5 AD |
1156 | return ERR_PTR(-EINVAL); |
1157 | } | |
1158 | ||
1159 | /* Don't add one table to multiple lists. */ | |
35aad0ff | 1160 | table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL); |
6beceee5 AD |
1161 | if (!table) { |
1162 | ret = -ENOMEM; | |
1163 | goto out; | |
1da177e4 LT |
1164 | } |
1165 | ||
53b8a315 | 1166 | countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids; |
18bc89aa | 1167 | newinfo = vmalloc(sizeof(*newinfo) + countersize); |
1da177e4 LT |
1168 | ret = -ENOMEM; |
1169 | if (!newinfo) | |
6beceee5 | 1170 | goto free_table; |
1da177e4 | 1171 | |
df07a81e AV |
1172 | p = vmalloc(repl->entries_size); |
1173 | if (!p) | |
1da177e4 LT |
1174 | goto free_newinfo; |
1175 | ||
df07a81e AV |
1176 | memcpy(p, repl->entries, repl->entries_size); |
1177 | newinfo->entries = p; | |
1178 | ||
1179 | newinfo->entries_size = repl->entries_size; | |
1180 | newinfo->nentries = repl->nentries; | |
1da177e4 LT |
1181 | |
1182 | if (countersize) | |
1183 | memset(newinfo->counters, 0, countersize); | |
1184 | ||
1185 | /* fill in newinfo and parse the entries */ | |
1186 | newinfo->chainstack = NULL; | |
df07a81e AV |
1187 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { |
1188 | if ((repl->valid_hooks & (1 << i)) == 0) | |
1189 | newinfo->hook_entry[i] = NULL; | |
1190 | else | |
1191 | newinfo->hook_entry[i] = p + | |
1192 | ((char *)repl->hook_entry[i] - repl->entries); | |
1193 | } | |
a83d8e8d | 1194 | ret = translate_table(net, repl->name, newinfo); |
1da177e4 LT |
1195 | if (ret != 0) { |
1196 | BUGPRINT("Translate_table failed\n"); | |
1197 | goto free_chainstack; | |
1198 | } | |
1199 | ||
1200 | if (table->check && table->check(newinfo, table->valid_hooks)) { | |
1201 | BUGPRINT("The table doesn't like its own initial data, lol\n"); | |
6beceee5 | 1202 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
1203 | } |
1204 | ||
1205 | table->private = newinfo; | |
1206 | rwlock_init(&table->lock); | |
57b47a53 | 1207 | ret = mutex_lock_interruptible(&ebt_mutex); |
1da177e4 LT |
1208 | if (ret != 0) |
1209 | goto free_chainstack; | |
1210 | ||
511061e2 | 1211 | list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) { |
df0933dc PM |
1212 | if (strcmp(t->name, table->name) == 0) { |
1213 | ret = -EEXIST; | |
1214 | BUGPRINT("Table name already exists\n"); | |
1215 | goto free_unlock; | |
1216 | } | |
1da177e4 LT |
1217 | } |
1218 | ||
1219 | /* Hold a reference count if the chains aren't empty */ | |
1220 | if (newinfo->nentries && !try_module_get(table->me)) { | |
1221 | ret = -ENOENT; | |
1222 | goto free_unlock; | |
1223 | } | |
511061e2 | 1224 | list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]); |
57b47a53 | 1225 | mutex_unlock(&ebt_mutex); |
6beceee5 | 1226 | return table; |
1da177e4 | 1227 | free_unlock: |
57b47a53 | 1228 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1229 | free_chainstack: |
1230 | if (newinfo->chainstack) { | |
6f912042 | 1231 | for_each_possible_cpu(i) |
1da177e4 LT |
1232 | vfree(newinfo->chainstack[i]); |
1233 | vfree(newinfo->chainstack); | |
1234 | } | |
1235 | vfree(newinfo->entries); | |
1236 | free_newinfo: | |
1237 | vfree(newinfo); | |
6beceee5 AD |
1238 | free_table: |
1239 | kfree(table); | |
1240 | out: | |
1241 | return ERR_PTR(ret); | |
1da177e4 LT |
1242 | } |
1243 | ||
f54e9367 | 1244 | void ebt_unregister_table(struct net *net, struct ebt_table *table) |
1da177e4 LT |
1245 | { |
1246 | int i; | |
1247 | ||
1248 | if (!table) { | |
1249 | BUGPRINT("Request to unregister NULL table!!!\n"); | |
1250 | return; | |
1251 | } | |
57b47a53 | 1252 | mutex_lock(&ebt_mutex); |
df0933dc | 1253 | list_del(&table->list); |
57b47a53 | 1254 | mutex_unlock(&ebt_mutex); |
dbcdf85a | 1255 | EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size, |
f54e9367 | 1256 | ebt_cleanup_entry, net, NULL); |
dbcdf85a AD |
1257 | if (table->private->nentries) |
1258 | module_put(table->me); | |
68d31872 | 1259 | vfree(table->private->entries); |
1da177e4 | 1260 | if (table->private->chainstack) { |
6f912042 | 1261 | for_each_possible_cpu(i) |
1da177e4 LT |
1262 | vfree(table->private->chainstack[i]); |
1263 | vfree(table->private->chainstack); | |
1264 | } | |
1265 | vfree(table->private); | |
6beceee5 | 1266 | kfree(table); |
1da177e4 LT |
1267 | } |
1268 | ||
1269 | /* userspace just supplied us with counters */ | |
49facff9 FW |
1270 | static int do_update_counters(struct net *net, const char *name, |
1271 | struct ebt_counter __user *counters, | |
1272 | unsigned int num_counters, | |
1273 | const void __user *user, unsigned int len) | |
1da177e4 LT |
1274 | { |
1275 | int i, ret; | |
1276 | struct ebt_counter *tmp; | |
1da177e4 LT |
1277 | struct ebt_table *t; |
1278 | ||
49facff9 | 1279 | if (num_counters == 0) |
1da177e4 LT |
1280 | return -EINVAL; |
1281 | ||
49facff9 FW |
1282 | tmp = vmalloc(num_counters * sizeof(*tmp)); |
1283 | if (!tmp) | |
1da177e4 | 1284 | return -ENOMEM; |
1da177e4 | 1285 | |
49facff9 | 1286 | t = find_table_lock(net, name, &ret, &ebt_mutex); |
1da177e4 LT |
1287 | if (!t) |
1288 | goto free_tmp; | |
1289 | ||
49facff9 | 1290 | if (num_counters != t->private->nentries) { |
1da177e4 LT |
1291 | BUGPRINT("Wrong nr of counters\n"); |
1292 | ret = -EINVAL; | |
1293 | goto unlock_mutex; | |
1294 | } | |
1295 | ||
49facff9 | 1296 | if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) { |
1da177e4 LT |
1297 | ret = -EFAULT; |
1298 | goto unlock_mutex; | |
1299 | } | |
1300 | ||
1301 | /* we want an atomic add of the counters */ | |
1302 | write_lock_bh(&t->lock); | |
1303 | ||
1304 | /* we add to the counters of the first cpu */ | |
49facff9 | 1305 | for (i = 0; i < num_counters; i++) { |
1da177e4 LT |
1306 | t->private->counters[i].pcnt += tmp[i].pcnt; |
1307 | t->private->counters[i].bcnt += tmp[i].bcnt; | |
1308 | } | |
1309 | ||
1310 | write_unlock_bh(&t->lock); | |
1311 | ret = 0; | |
1312 | unlock_mutex: | |
57b47a53 | 1313 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1314 | free_tmp: |
1315 | vfree(tmp); | |
1316 | return ret; | |
1317 | } | |
1318 | ||
49facff9 FW |
1319 | static int update_counters(struct net *net, const void __user *user, |
1320 | unsigned int len) | |
1321 | { | |
1322 | struct ebt_replace hlp; | |
1323 | ||
1324 | if (copy_from_user(&hlp, user, sizeof(hlp))) | |
1325 | return -EFAULT; | |
1326 | ||
1327 | if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter)) | |
1328 | return -EINVAL; | |
1329 | ||
1330 | return do_update_counters(net, hlp.name, hlp.counters, | |
1331 | hlp.num_counters, user, len); | |
1332 | } | |
1333 | ||
d5d1baa1 JE |
1334 | static inline int ebt_make_matchname(const struct ebt_entry_match *m, |
1335 | const char *base, char __user *ubase) | |
1da177e4 | 1336 | { |
1e419cd9 | 1337 | char __user *hlp = ubase + ((char *)m - base); |
1da177e4 LT |
1338 | if (copy_to_user(hlp, m->u.match->name, EBT_FUNCTION_MAXNAMELEN)) |
1339 | return -EFAULT; | |
1340 | return 0; | |
1341 | } | |
1342 | ||
d5d1baa1 JE |
1343 | static inline int ebt_make_watchername(const struct ebt_entry_watcher *w, |
1344 | const char *base, char __user *ubase) | |
1da177e4 | 1345 | { |
1e419cd9 | 1346 | char __user *hlp = ubase + ((char *)w - base); |
1da177e4 LT |
1347 | if (copy_to_user(hlp , w->u.watcher->name, EBT_FUNCTION_MAXNAMELEN)) |
1348 | return -EFAULT; | |
1349 | return 0; | |
1350 | } | |
1351 | ||
d5d1baa1 JE |
1352 | static inline int |
1353 | ebt_make_names(struct ebt_entry *e, const char *base, char __user *ubase) | |
1da177e4 LT |
1354 | { |
1355 | int ret; | |
1e419cd9 | 1356 | char __user *hlp; |
d5d1baa1 | 1357 | const struct ebt_entry_target *t; |
1da177e4 | 1358 | |
40642f95 | 1359 | if (e->bitmask == 0) |
1da177e4 LT |
1360 | return 0; |
1361 | ||
1e419cd9 | 1362 | hlp = ubase + (((char *)e + e->target_offset) - base); |
1da177e4 | 1363 | t = (struct ebt_entry_target *)(((char *)e) + e->target_offset); |
9d6f229f | 1364 | |
1da177e4 LT |
1365 | ret = EBT_MATCH_ITERATE(e, ebt_make_matchname, base, ubase); |
1366 | if (ret != 0) | |
1367 | return ret; | |
1368 | ret = EBT_WATCHER_ITERATE(e, ebt_make_watchername, base, ubase); | |
1369 | if (ret != 0) | |
1370 | return ret; | |
1371 | if (copy_to_user(hlp, t->u.target->name, EBT_FUNCTION_MAXNAMELEN)) | |
1372 | return -EFAULT; | |
1373 | return 0; | |
1374 | } | |
1375 | ||
837395aa FW |
1376 | static int copy_counters_to_user(struct ebt_table *t, |
1377 | const struct ebt_counter *oldcounters, | |
1378 | void __user *user, unsigned int num_counters, | |
1379 | unsigned int nentries) | |
1380 | { | |
1381 | struct ebt_counter *counterstmp; | |
1382 | int ret = 0; | |
1383 | ||
1384 | /* userspace might not need the counters */ | |
1385 | if (num_counters == 0) | |
1386 | return 0; | |
1387 | ||
1388 | if (num_counters != nentries) { | |
1389 | BUGPRINT("Num_counters wrong\n"); | |
1390 | return -EINVAL; | |
1391 | } | |
1392 | ||
1393 | counterstmp = vmalloc(nentries * sizeof(*counterstmp)); | |
1394 | if (!counterstmp) | |
1395 | return -ENOMEM; | |
1396 | ||
1397 | write_lock_bh(&t->lock); | |
1398 | get_counters(oldcounters, counterstmp, nentries); | |
1399 | write_unlock_bh(&t->lock); | |
1400 | ||
1401 | if (copy_to_user(user, counterstmp, | |
1402 | nentries * sizeof(struct ebt_counter))) | |
1403 | ret = -EFAULT; | |
1404 | vfree(counterstmp); | |
1405 | return ret; | |
1406 | } | |
1407 | ||
57b47a53 | 1408 | /* called with ebt_mutex locked */ |
1da177e4 | 1409 | static int copy_everything_to_user(struct ebt_table *t, void __user *user, |
d5d1baa1 | 1410 | const int *len, int cmd) |
1da177e4 LT |
1411 | { |
1412 | struct ebt_replace tmp; | |
d5d1baa1 | 1413 | const struct ebt_counter *oldcounters; |
1da177e4 | 1414 | unsigned int entries_size, nentries; |
837395aa | 1415 | int ret; |
1da177e4 LT |
1416 | char *entries; |
1417 | ||
1418 | if (cmd == EBT_SO_GET_ENTRIES) { | |
1419 | entries_size = t->private->entries_size; | |
1420 | nentries = t->private->nentries; | |
1421 | entries = t->private->entries; | |
1422 | oldcounters = t->private->counters; | |
1423 | } else { | |
1424 | entries_size = t->table->entries_size; | |
1425 | nentries = t->table->nentries; | |
1426 | entries = t->table->entries; | |
1427 | oldcounters = t->table->counters; | |
1428 | } | |
1429 | ||
90b89af7 | 1430 | if (copy_from_user(&tmp, user, sizeof(tmp))) |
1da177e4 | 1431 | return -EFAULT; |
1da177e4 LT |
1432 | |
1433 | if (*len != sizeof(struct ebt_replace) + entries_size + | |
90b89af7 | 1434 | (tmp.num_counters? nentries * sizeof(struct ebt_counter): 0)) |
1da177e4 | 1435 | return -EINVAL; |
1da177e4 LT |
1436 | |
1437 | if (tmp.nentries != nentries) { | |
1438 | BUGPRINT("Nentries wrong\n"); | |
1439 | return -EINVAL; | |
1440 | } | |
1441 | ||
1442 | if (tmp.entries_size != entries_size) { | |
1443 | BUGPRINT("Wrong size\n"); | |
1444 | return -EINVAL; | |
1445 | } | |
1446 | ||
837395aa FW |
1447 | ret = copy_counters_to_user(t, oldcounters, tmp.counters, |
1448 | tmp.num_counters, nentries); | |
1449 | if (ret) | |
1450 | return ret; | |
1da177e4 LT |
1451 | |
1452 | if (copy_to_user(tmp.entries, entries, entries_size)) { | |
1453 | BUGPRINT("Couldn't copy entries to userspace\n"); | |
1454 | return -EFAULT; | |
1455 | } | |
1456 | /* set the match/watcher/target names right */ | |
1457 | return EBT_ENTRY_ITERATE(entries, entries_size, | |
1458 | ebt_make_names, entries, tmp.entries); | |
1459 | } | |
1460 | ||
1461 | static int do_ebt_set_ctl(struct sock *sk, | |
1462 | int cmd, void __user *user, unsigned int len) | |
1463 | { | |
1464 | int ret; | |
1465 | ||
dce766af FW |
1466 | if (!capable(CAP_NET_ADMIN)) |
1467 | return -EPERM; | |
1468 | ||
1da177e4 LT |
1469 | switch(cmd) { |
1470 | case EBT_SO_SET_ENTRIES: | |
511061e2 | 1471 | ret = do_replace(sock_net(sk), user, len); |
1da177e4 LT |
1472 | break; |
1473 | case EBT_SO_SET_COUNTERS: | |
511061e2 | 1474 | ret = update_counters(sock_net(sk), user, len); |
1da177e4 LT |
1475 | break; |
1476 | default: | |
1477 | ret = -EINVAL; | |
81e675c2 | 1478 | } |
1da177e4 LT |
1479 | return ret; |
1480 | } | |
1481 | ||
1482 | static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) | |
1483 | { | |
1484 | int ret; | |
1485 | struct ebt_replace tmp; | |
1486 | struct ebt_table *t; | |
1487 | ||
dce766af FW |
1488 | if (!capable(CAP_NET_ADMIN)) |
1489 | return -EPERM; | |
1490 | ||
1da177e4 LT |
1491 | if (copy_from_user(&tmp, user, sizeof(tmp))) |
1492 | return -EFAULT; | |
1493 | ||
511061e2 | 1494 | t = find_table_lock(sock_net(sk), tmp.name, &ret, &ebt_mutex); |
1da177e4 LT |
1495 | if (!t) |
1496 | return ret; | |
1497 | ||
1498 | switch(cmd) { | |
1499 | case EBT_SO_GET_INFO: | |
1500 | case EBT_SO_GET_INIT_INFO: | |
1501 | if (*len != sizeof(struct ebt_replace)){ | |
1502 | ret = -EINVAL; | |
57b47a53 | 1503 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1504 | break; |
1505 | } | |
1506 | if (cmd == EBT_SO_GET_INFO) { | |
1507 | tmp.nentries = t->private->nentries; | |
1508 | tmp.entries_size = t->private->entries_size; | |
1509 | tmp.valid_hooks = t->valid_hooks; | |
1510 | } else { | |
1511 | tmp.nentries = t->table->nentries; | |
1512 | tmp.entries_size = t->table->entries_size; | |
1513 | tmp.valid_hooks = t->table->valid_hooks; | |
1514 | } | |
57b47a53 | 1515 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1516 | if (copy_to_user(user, &tmp, *len) != 0){ |
1517 | BUGPRINT("c2u Didn't work\n"); | |
1518 | ret = -EFAULT; | |
1519 | break; | |
1520 | } | |
1521 | ret = 0; | |
1522 | break; | |
1523 | ||
1524 | case EBT_SO_GET_ENTRIES: | |
1525 | case EBT_SO_GET_INIT_ENTRIES: | |
1526 | ret = copy_everything_to_user(t, user, len, cmd); | |
57b47a53 | 1527 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1528 | break; |
1529 | ||
1530 | default: | |
57b47a53 | 1531 | mutex_unlock(&ebt_mutex); |
1da177e4 LT |
1532 | ret = -EINVAL; |
1533 | } | |
1534 | ||
1535 | return ret; | |
1536 | } | |
1537 | ||
81e675c2 FW |
1538 | #ifdef CONFIG_COMPAT |
1539 | /* 32 bit-userspace compatibility definitions. */ | |
1540 | struct compat_ebt_replace { | |
1541 | char name[EBT_TABLE_MAXNAMELEN]; | |
1542 | compat_uint_t valid_hooks; | |
1543 | compat_uint_t nentries; | |
1544 | compat_uint_t entries_size; | |
1545 | /* start of the chains */ | |
1546 | compat_uptr_t hook_entry[NF_BR_NUMHOOKS]; | |
1547 | /* nr of counters userspace expects back */ | |
1548 | compat_uint_t num_counters; | |
1549 | /* where the kernel will put the old counters. */ | |
1550 | compat_uptr_t counters; | |
1551 | compat_uptr_t entries; | |
1552 | }; | |
1553 | ||
1554 | /* struct ebt_entry_match, _target and _watcher have same layout */ | |
1555 | struct compat_ebt_entry_mwt { | |
1556 | union { | |
1557 | char name[EBT_FUNCTION_MAXNAMELEN]; | |
1558 | compat_uptr_t ptr; | |
1559 | } u; | |
1560 | compat_uint_t match_size; | |
1561 | compat_uint_t data[0]; | |
1562 | }; | |
1563 | ||
1564 | /* account for possible padding between match_size and ->data */ | |
1565 | static int ebt_compat_entry_padsize(void) | |
1566 | { | |
1567 | BUILD_BUG_ON(XT_ALIGN(sizeof(struct ebt_entry_match)) < | |
1568 | COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt))); | |
1569 | return (int) XT_ALIGN(sizeof(struct ebt_entry_match)) - | |
1570 | COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt)); | |
1571 | } | |
1572 | ||
1573 | static int ebt_compat_match_offset(const struct xt_match *match, | |
1574 | unsigned int userlen) | |
1575 | { | |
1576 | /* | |
1577 | * ebt_among needs special handling. The kernel .matchsize is | |
1578 | * set to -1 at registration time; at runtime an EBT_ALIGN()ed | |
1579 | * value is expected. | |
1580 | * Example: userspace sends 4500, ebt_among.c wants 4504. | |
1581 | */ | |
1582 | if (unlikely(match->matchsize == -1)) | |
1583 | return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen); | |
1584 | return xt_compat_match_offset(match); | |
1585 | } | |
1586 | ||
1587 | static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr, | |
1588 | unsigned int *size) | |
1589 | { | |
1590 | const struct xt_match *match = m->u.match; | |
1591 | struct compat_ebt_entry_mwt __user *cm = *dstptr; | |
1592 | int off = ebt_compat_match_offset(match, m->match_size); | |
1593 | compat_uint_t msize = m->match_size - off; | |
1594 | ||
1595 | BUG_ON(off >= m->match_size); | |
1596 | ||
1597 | if (copy_to_user(cm->u.name, match->name, | |
1598 | strlen(match->name) + 1) || put_user(msize, &cm->match_size)) | |
1599 | return -EFAULT; | |
1600 | ||
1601 | if (match->compat_to_user) { | |
1602 | if (match->compat_to_user(cm->data, m->data)) | |
1603 | return -EFAULT; | |
1604 | } else if (copy_to_user(cm->data, m->data, msize)) | |
1605 | return -EFAULT; | |
1606 | ||
1607 | *size -= ebt_compat_entry_padsize() + off; | |
1608 | *dstptr = cm->data; | |
1609 | *dstptr += msize; | |
1610 | return 0; | |
1611 | } | |
1612 | ||
1613 | static int compat_target_to_user(struct ebt_entry_target *t, | |
1614 | void __user **dstptr, | |
1615 | unsigned int *size) | |
1616 | { | |
1617 | const struct xt_target *target = t->u.target; | |
1618 | struct compat_ebt_entry_mwt __user *cm = *dstptr; | |
1619 | int off = xt_compat_target_offset(target); | |
1620 | compat_uint_t tsize = t->target_size - off; | |
1621 | ||
1622 | BUG_ON(off >= t->target_size); | |
1623 | ||
1624 | if (copy_to_user(cm->u.name, target->name, | |
1625 | strlen(target->name) + 1) || put_user(tsize, &cm->match_size)) | |
1626 | return -EFAULT; | |
1627 | ||
1628 | if (target->compat_to_user) { | |
1629 | if (target->compat_to_user(cm->data, t->data)) | |
1630 | return -EFAULT; | |
1631 | } else if (copy_to_user(cm->data, t->data, tsize)) | |
1632 | return -EFAULT; | |
1633 | ||
1634 | *size -= ebt_compat_entry_padsize() + off; | |
1635 | *dstptr = cm->data; | |
1636 | *dstptr += tsize; | |
1637 | return 0; | |
1638 | } | |
1639 | ||
1640 | static int compat_watcher_to_user(struct ebt_entry_watcher *w, | |
1641 | void __user **dstptr, | |
1642 | unsigned int *size) | |
1643 | { | |
1644 | return compat_target_to_user((struct ebt_entry_target *)w, | |
1645 | dstptr, size); | |
1646 | } | |
1647 | ||
1648 | static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr, | |
1649 | unsigned int *size) | |
1650 | { | |
1651 | struct ebt_entry_target *t; | |
1652 | struct ebt_entry __user *ce; | |
1653 | u32 watchers_offset, target_offset, next_offset; | |
1654 | compat_uint_t origsize; | |
1655 | int ret; | |
1656 | ||
1657 | if (e->bitmask == 0) { | |
1658 | if (*size < sizeof(struct ebt_entries)) | |
1659 | return -EINVAL; | |
1660 | if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries))) | |
1661 | return -EFAULT; | |
1662 | ||
1663 | *dstptr += sizeof(struct ebt_entries); | |
1664 | *size -= sizeof(struct ebt_entries); | |
1665 | return 0; | |
1666 | } | |
1667 | ||
1668 | if (*size < sizeof(*ce)) | |
1669 | return -EINVAL; | |
1670 | ||
1671 | ce = (struct ebt_entry __user *)*dstptr; | |
1672 | if (copy_to_user(ce, e, sizeof(*ce))) | |
1673 | return -EFAULT; | |
1674 | ||
1675 | origsize = *size; | |
1676 | *dstptr += sizeof(*ce); | |
1677 | ||
1678 | ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size); | |
1679 | if (ret) | |
1680 | return ret; | |
1681 | watchers_offset = e->watchers_offset - (origsize - *size); | |
1682 | ||
1683 | ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size); | |
1684 | if (ret) | |
1685 | return ret; | |
1686 | target_offset = e->target_offset - (origsize - *size); | |
1687 | ||
1688 | t = (struct ebt_entry_target *) ((char *) e + e->target_offset); | |
1689 | ||
1690 | ret = compat_target_to_user(t, dstptr, size); | |
1691 | if (ret) | |
1692 | return ret; | |
1693 | next_offset = e->next_offset - (origsize - *size); | |
1694 | ||
1695 | if (put_user(watchers_offset, &ce->watchers_offset) || | |
1696 | put_user(target_offset, &ce->target_offset) || | |
1697 | put_user(next_offset, &ce->next_offset)) | |
1698 | return -EFAULT; | |
1699 | ||
1700 | *size -= sizeof(*ce); | |
1701 | return 0; | |
1702 | } | |
1703 | ||
1704 | static int compat_calc_match(struct ebt_entry_match *m, int *off) | |
1705 | { | |
1706 | *off += ebt_compat_match_offset(m->u.match, m->match_size); | |
1707 | *off += ebt_compat_entry_padsize(); | |
1708 | return 0; | |
1709 | } | |
1710 | ||
1711 | static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off) | |
1712 | { | |
1713 | *off += xt_compat_target_offset(w->u.watcher); | |
1714 | *off += ebt_compat_entry_padsize(); | |
1715 | return 0; | |
1716 | } | |
1717 | ||
1718 | static int compat_calc_entry(const struct ebt_entry *e, | |
1719 | const struct ebt_table_info *info, | |
1720 | const void *base, | |
1721 | struct compat_ebt_replace *newinfo) | |
1722 | { | |
1723 | const struct ebt_entry_target *t; | |
1724 | unsigned int entry_offset; | |
1725 | int off, ret, i; | |
1726 | ||
1727 | if (e->bitmask == 0) | |
1728 | return 0; | |
1729 | ||
1730 | off = 0; | |
1731 | entry_offset = (void *)e - base; | |
1732 | ||
1733 | EBT_MATCH_ITERATE(e, compat_calc_match, &off); | |
1734 | EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off); | |
1735 | ||
1736 | t = (const struct ebt_entry_target *) ((char *) e + e->target_offset); | |
1737 | ||
1738 | off += xt_compat_target_offset(t->u.target); | |
1739 | off += ebt_compat_entry_padsize(); | |
1740 | ||
1741 | newinfo->entries_size -= off; | |
1742 | ||
1743 | ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off); | |
1744 | if (ret) | |
1745 | return ret; | |
1746 | ||
1747 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
1748 | const void *hookptr = info->hook_entry[i]; | |
1749 | if (info->hook_entry[i] && | |
1750 | (e < (struct ebt_entry *)(base - hookptr))) { | |
1751 | newinfo->hook_entry[i] -= off; | |
1752 | pr_debug("0x%08X -> 0x%08X\n", | |
1753 | newinfo->hook_entry[i] + off, | |
1754 | newinfo->hook_entry[i]); | |
1755 | } | |
1756 | } | |
1757 | ||
1758 | return 0; | |
1759 | } | |
1760 | ||
1761 | ||
1762 | static int compat_table_info(const struct ebt_table_info *info, | |
1763 | struct compat_ebt_replace *newinfo) | |
1764 | { | |
1765 | unsigned int size = info->entries_size; | |
1766 | const void *entries = info->entries; | |
1767 | ||
1768 | newinfo->entries_size = size; | |
1769 | ||
1770 | return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info, | |
1771 | entries, newinfo); | |
1772 | } | |
1773 | ||
1774 | static int compat_copy_everything_to_user(struct ebt_table *t, | |
1775 | void __user *user, int *len, int cmd) | |
1776 | { | |
1777 | struct compat_ebt_replace repl, tmp; | |
1778 | struct ebt_counter *oldcounters; | |
1779 | struct ebt_table_info tinfo; | |
1780 | int ret; | |
1781 | void __user *pos; | |
1782 | ||
1783 | memset(&tinfo, 0, sizeof(tinfo)); | |
1784 | ||
1785 | if (cmd == EBT_SO_GET_ENTRIES) { | |
1786 | tinfo.entries_size = t->private->entries_size; | |
1787 | tinfo.nentries = t->private->nentries; | |
1788 | tinfo.entries = t->private->entries; | |
1789 | oldcounters = t->private->counters; | |
1790 | } else { | |
1791 | tinfo.entries_size = t->table->entries_size; | |
1792 | tinfo.nentries = t->table->nentries; | |
1793 | tinfo.entries = t->table->entries; | |
1794 | oldcounters = t->table->counters; | |
1795 | } | |
1796 | ||
1797 | if (copy_from_user(&tmp, user, sizeof(tmp))) | |
1798 | return -EFAULT; | |
1799 | ||
1800 | if (tmp.nentries != tinfo.nentries || | |
1801 | (tmp.num_counters && tmp.num_counters != tinfo.nentries)) | |
1802 | return -EINVAL; | |
1803 | ||
1804 | memcpy(&repl, &tmp, sizeof(repl)); | |
1805 | if (cmd == EBT_SO_GET_ENTRIES) | |
1806 | ret = compat_table_info(t->private, &repl); | |
1807 | else | |
1808 | ret = compat_table_info(&tinfo, &repl); | |
1809 | if (ret) | |
1810 | return ret; | |
1811 | ||
1812 | if (*len != sizeof(tmp) + repl.entries_size + | |
1813 | (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) { | |
1814 | pr_err("wrong size: *len %d, entries_size %u, replsz %d\n", | |
1815 | *len, tinfo.entries_size, repl.entries_size); | |
1816 | return -EINVAL; | |
1817 | } | |
1818 | ||
1819 | /* userspace might not need the counters */ | |
1820 | ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters), | |
1821 | tmp.num_counters, tinfo.nentries); | |
1822 | if (ret) | |
1823 | return ret; | |
1824 | ||
1825 | pos = compat_ptr(tmp.entries); | |
1826 | return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size, | |
1827 | compat_copy_entry_to_user, &pos, &tmp.entries_size); | |
1828 | } | |
1829 | ||
1830 | struct ebt_entries_buf_state { | |
1831 | char *buf_kern_start; /* kernel buffer to copy (translated) data to */ | |
1832 | u32 buf_kern_len; /* total size of kernel buffer */ | |
1833 | u32 buf_kern_offset; /* amount of data copied so far */ | |
1834 | u32 buf_user_offset; /* read position in userspace buffer */ | |
1835 | }; | |
1836 | ||
1837 | static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz) | |
1838 | { | |
1839 | state->buf_kern_offset += sz; | |
1840 | return state->buf_kern_offset >= sz ? 0 : -EINVAL; | |
1841 | } | |
1842 | ||
1843 | static int ebt_buf_add(struct ebt_entries_buf_state *state, | |
1844 | void *data, unsigned int sz) | |
1845 | { | |
1846 | if (state->buf_kern_start == NULL) | |
1847 | goto count_only; | |
1848 | ||
1849 | BUG_ON(state->buf_kern_offset + sz > state->buf_kern_len); | |
1850 | ||
1851 | memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz); | |
1852 | ||
1853 | count_only: | |
1854 | state->buf_user_offset += sz; | |
1855 | return ebt_buf_count(state, sz); | |
1856 | } | |
1857 | ||
1858 | static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz) | |
1859 | { | |
1860 | char *b = state->buf_kern_start; | |
1861 | ||
1862 | BUG_ON(b && state->buf_kern_offset > state->buf_kern_len); | |
1863 | ||
1864 | if (b != NULL && sz > 0) | |
1865 | memset(b + state->buf_kern_offset, 0, sz); | |
1866 | /* do not adjust ->buf_user_offset here, we added kernel-side padding */ | |
1867 | return ebt_buf_count(state, sz); | |
1868 | } | |
1869 | ||
1870 | enum compat_mwt { | |
1871 | EBT_COMPAT_MATCH, | |
1872 | EBT_COMPAT_WATCHER, | |
1873 | EBT_COMPAT_TARGET, | |
1874 | }; | |
1875 | ||
1876 | static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt, | |
1877 | enum compat_mwt compat_mwt, | |
1878 | struct ebt_entries_buf_state *state, | |
1879 | const unsigned char *base) | |
1880 | { | |
1881 | char name[EBT_FUNCTION_MAXNAMELEN]; | |
1882 | struct xt_match *match; | |
1883 | struct xt_target *wt; | |
1884 | void *dst = NULL; | |
1885 | int off, pad = 0, ret = 0; | |
1886 | unsigned int size_kern, entry_offset, match_size = mwt->match_size; | |
1887 | ||
1888 | strlcpy(name, mwt->u.name, sizeof(name)); | |
1889 | ||
1890 | if (state->buf_kern_start) | |
1891 | dst = state->buf_kern_start + state->buf_kern_offset; | |
1892 | ||
1893 | entry_offset = (unsigned char *) mwt - base; | |
1894 | switch (compat_mwt) { | |
1895 | case EBT_COMPAT_MATCH: | |
1896 | match = try_then_request_module(xt_find_match(NFPROTO_BRIDGE, | |
1897 | name, 0), "ebt_%s", name); | |
1898 | if (match == NULL) | |
1899 | return -ENOENT; | |
1900 | if (IS_ERR(match)) | |
1901 | return PTR_ERR(match); | |
1902 | ||
1903 | off = ebt_compat_match_offset(match, match_size); | |
1904 | if (dst) { | |
1905 | if (match->compat_from_user) | |
1906 | match->compat_from_user(dst, mwt->data); | |
1907 | else | |
1908 | memcpy(dst, mwt->data, match_size); | |
1909 | } | |
1910 | ||
1911 | size_kern = match->matchsize; | |
1912 | if (unlikely(size_kern == -1)) | |
1913 | size_kern = match_size; | |
1914 | module_put(match->me); | |
1915 | break; | |
1916 | case EBT_COMPAT_WATCHER: /* fallthrough */ | |
1917 | case EBT_COMPAT_TARGET: | |
1918 | wt = try_then_request_module(xt_find_target(NFPROTO_BRIDGE, | |
1919 | name, 0), "ebt_%s", name); | |
1920 | if (wt == NULL) | |
1921 | return -ENOENT; | |
1922 | if (IS_ERR(wt)) | |
1923 | return PTR_ERR(wt); | |
1924 | off = xt_compat_target_offset(wt); | |
1925 | ||
1926 | if (dst) { | |
1927 | if (wt->compat_from_user) | |
1928 | wt->compat_from_user(dst, mwt->data); | |
1929 | else | |
1930 | memcpy(dst, mwt->data, match_size); | |
1931 | } | |
1932 | ||
1933 | size_kern = wt->targetsize; | |
1934 | module_put(wt->me); | |
1935 | break; | |
1936 | } | |
1937 | ||
1938 | if (!dst) { | |
1939 | ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, | |
1940 | off + ebt_compat_entry_padsize()); | |
1941 | if (ret < 0) | |
1942 | return ret; | |
1943 | } | |
1944 | ||
1945 | state->buf_kern_offset += match_size + off; | |
1946 | state->buf_user_offset += match_size; | |
1947 | pad = XT_ALIGN(size_kern) - size_kern; | |
1948 | ||
1949 | if (pad > 0 && dst) { | |
1950 | BUG_ON(state->buf_kern_len <= pad); | |
1951 | BUG_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad); | |
1952 | memset(dst + size_kern, 0, pad); | |
1953 | } | |
1954 | return off + match_size; | |
1955 | } | |
1956 | ||
1957 | /* | |
1958 | * return size of all matches, watchers or target, including necessary | |
1959 | * alignment and padding. | |
1960 | */ | |
1961 | static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32, | |
1962 | unsigned int size_left, enum compat_mwt type, | |
1963 | struct ebt_entries_buf_state *state, const void *base) | |
1964 | { | |
1965 | int growth = 0; | |
1966 | char *buf; | |
1967 | ||
1968 | if (size_left == 0) | |
1969 | return 0; | |
1970 | ||
1971 | buf = (char *) match32; | |
1972 | ||
1973 | while (size_left >= sizeof(*match32)) { | |
1974 | struct ebt_entry_match *match_kern; | |
1975 | int ret; | |
1976 | ||
1977 | match_kern = (struct ebt_entry_match *) state->buf_kern_start; | |
1978 | if (match_kern) { | |
1979 | char *tmp; | |
1980 | tmp = state->buf_kern_start + state->buf_kern_offset; | |
1981 | match_kern = (struct ebt_entry_match *) tmp; | |
1982 | } | |
1983 | ret = ebt_buf_add(state, buf, sizeof(*match32)); | |
1984 | if (ret < 0) | |
1985 | return ret; | |
1986 | size_left -= sizeof(*match32); | |
1987 | ||
1988 | /* add padding before match->data (if any) */ | |
1989 | ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize()); | |
1990 | if (ret < 0) | |
1991 | return ret; | |
1992 | ||
1993 | if (match32->match_size > size_left) | |
1994 | return -EINVAL; | |
1995 | ||
1996 | size_left -= match32->match_size; | |
1997 | ||
1998 | ret = compat_mtw_from_user(match32, type, state, base); | |
1999 | if (ret < 0) | |
2000 | return ret; | |
2001 | ||
2002 | BUG_ON(ret < match32->match_size); | |
2003 | growth += ret - match32->match_size; | |
2004 | growth += ebt_compat_entry_padsize(); | |
2005 | ||
2006 | buf += sizeof(*match32); | |
2007 | buf += match32->match_size; | |
2008 | ||
2009 | if (match_kern) | |
2010 | match_kern->match_size = ret; | |
2011 | ||
2012 | WARN_ON(type == EBT_COMPAT_TARGET && size_left); | |
2013 | match32 = (struct compat_ebt_entry_mwt *) buf; | |
2014 | } | |
2015 | ||
2016 | return growth; | |
2017 | } | |
2018 | ||
2019 | #define EBT_COMPAT_WATCHER_ITERATE(e, fn, args...) \ | |
2020 | ({ \ | |
2021 | unsigned int __i; \ | |
2022 | int __ret = 0; \ | |
2023 | struct compat_ebt_entry_mwt *__watcher; \ | |
2024 | \ | |
2025 | for (__i = e->watchers_offset; \ | |
2026 | __i < (e)->target_offset; \ | |
2027 | __i += __watcher->watcher_size + \ | |
2028 | sizeof(struct compat_ebt_entry_mwt)) { \ | |
2029 | __watcher = (void *)(e) + __i; \ | |
2030 | __ret = fn(__watcher , ## args); \ | |
2031 | if (__ret != 0) \ | |
2032 | break; \ | |
2033 | } \ | |
2034 | if (__ret == 0) { \ | |
2035 | if (__i != (e)->target_offset) \ | |
2036 | __ret = -EINVAL; \ | |
2037 | } \ | |
2038 | __ret; \ | |
2039 | }) | |
2040 | ||
2041 | #define EBT_COMPAT_MATCH_ITERATE(e, fn, args...) \ | |
2042 | ({ \ | |
2043 | unsigned int __i; \ | |
2044 | int __ret = 0; \ | |
2045 | struct compat_ebt_entry_mwt *__match; \ | |
2046 | \ | |
2047 | for (__i = sizeof(struct ebt_entry); \ | |
2048 | __i < (e)->watchers_offset; \ | |
2049 | __i += __match->match_size + \ | |
2050 | sizeof(struct compat_ebt_entry_mwt)) { \ | |
2051 | __match = (void *)(e) + __i; \ | |
2052 | __ret = fn(__match , ## args); \ | |
2053 | if (__ret != 0) \ | |
2054 | break; \ | |
2055 | } \ | |
2056 | if (__ret == 0) { \ | |
2057 | if (__i != (e)->watchers_offset) \ | |
2058 | __ret = -EINVAL; \ | |
2059 | } \ | |
2060 | __ret; \ | |
2061 | }) | |
2062 | ||
2063 | /* called for all ebt_entry structures. */ | |
2064 | static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base, | |
2065 | unsigned int *total, | |
2066 | struct ebt_entries_buf_state *state) | |
2067 | { | |
2068 | unsigned int i, j, startoff, new_offset = 0; | |
2069 | /* stores match/watchers/targets & offset of next struct ebt_entry: */ | |
2070 | unsigned int offsets[4]; | |
2071 | unsigned int *offsets_update = NULL; | |
2072 | int ret; | |
2073 | char *buf_start; | |
2074 | ||
2075 | if (*total < sizeof(struct ebt_entries)) | |
2076 | return -EINVAL; | |
2077 | ||
2078 | if (!entry->bitmask) { | |
2079 | *total -= sizeof(struct ebt_entries); | |
2080 | return ebt_buf_add(state, entry, sizeof(struct ebt_entries)); | |
2081 | } | |
2082 | if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry)) | |
2083 | return -EINVAL; | |
2084 | ||
2085 | startoff = state->buf_user_offset; | |
2086 | /* pull in most part of ebt_entry, it does not need to be changed. */ | |
2087 | ret = ebt_buf_add(state, entry, | |
2088 | offsetof(struct ebt_entry, watchers_offset)); | |
2089 | if (ret < 0) | |
2090 | return ret; | |
2091 | ||
2092 | offsets[0] = sizeof(struct ebt_entry); /* matches come first */ | |
2093 | memcpy(&offsets[1], &entry->watchers_offset, | |
2094 | sizeof(offsets) - sizeof(offsets[0])); | |
2095 | ||
2096 | if (state->buf_kern_start) { | |
2097 | buf_start = state->buf_kern_start + state->buf_kern_offset; | |
2098 | offsets_update = (unsigned int *) buf_start; | |
2099 | } | |
2100 | ret = ebt_buf_add(state, &offsets[1], | |
2101 | sizeof(offsets) - sizeof(offsets[0])); | |
2102 | if (ret < 0) | |
2103 | return ret; | |
2104 | buf_start = (char *) entry; | |
2105 | /* | |
2106 | * 0: matches offset, always follows ebt_entry. | |
2107 | * 1: watchers offset, from ebt_entry structure | |
2108 | * 2: target offset, from ebt_entry structure | |
2109 | * 3: next ebt_entry offset, from ebt_entry structure | |
2110 | * | |
2111 | * offsets are relative to beginning of struct ebt_entry (i.e., 0). | |
2112 | */ | |
2113 | for (i = 0, j = 1 ; j < 4 ; j++, i++) { | |
2114 | struct compat_ebt_entry_mwt *match32; | |
2115 | unsigned int size; | |
2116 | char *buf = buf_start; | |
2117 | ||
2118 | buf = buf_start + offsets[i]; | |
2119 | if (offsets[i] > offsets[j]) | |
2120 | return -EINVAL; | |
2121 | ||
2122 | match32 = (struct compat_ebt_entry_mwt *) buf; | |
2123 | size = offsets[j] - offsets[i]; | |
2124 | ret = ebt_size_mwt(match32, size, i, state, base); | |
2125 | if (ret < 0) | |
2126 | return ret; | |
2127 | new_offset += ret; | |
2128 | if (offsets_update && new_offset) { | |
ff67e4e4 | 2129 | pr_debug("change offset %d to %d\n", |
81e675c2 FW |
2130 | offsets_update[i], offsets[j] + new_offset); |
2131 | offsets_update[i] = offsets[j] + new_offset; | |
2132 | } | |
2133 | } | |
2134 | ||
2135 | startoff = state->buf_user_offset - startoff; | |
2136 | ||
2137 | BUG_ON(*total < startoff); | |
2138 | *total -= startoff; | |
2139 | return 0; | |
2140 | } | |
2141 | ||
2142 | /* | |
2143 | * repl->entries_size is the size of the ebt_entry blob in userspace. | |
2144 | * It might need more memory when copied to a 64 bit kernel in case | |
2145 | * userspace is 32-bit. So, first task: find out how much memory is needed. | |
2146 | * | |
2147 | * Called before validation is performed. | |
2148 | */ | |
2149 | static int compat_copy_entries(unsigned char *data, unsigned int size_user, | |
2150 | struct ebt_entries_buf_state *state) | |
2151 | { | |
2152 | unsigned int size_remaining = size_user; | |
2153 | int ret; | |
2154 | ||
2155 | ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data, | |
2156 | &size_remaining, state); | |
2157 | if (ret < 0) | |
2158 | return ret; | |
2159 | ||
2160 | WARN_ON(size_remaining); | |
2161 | return state->buf_kern_offset; | |
2162 | } | |
2163 | ||
2164 | ||
2165 | static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl, | |
2166 | void __user *user, unsigned int len) | |
2167 | { | |
2168 | struct compat_ebt_replace tmp; | |
2169 | int i; | |
2170 | ||
2171 | if (len < sizeof(tmp)) | |
2172 | return -EINVAL; | |
2173 | ||
2174 | if (copy_from_user(&tmp, user, sizeof(tmp))) | |
2175 | return -EFAULT; | |
2176 | ||
2177 | if (len != sizeof(tmp) + tmp.entries_size) | |
2178 | return -EINVAL; | |
2179 | ||
2180 | if (tmp.entries_size == 0) | |
2181 | return -EINVAL; | |
2182 | ||
2183 | if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) / | |
2184 | NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter)) | |
2185 | return -ENOMEM; | |
2186 | if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) | |
2187 | return -ENOMEM; | |
2188 | ||
2189 | memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry)); | |
2190 | ||
2191 | /* starting with hook_entry, 32 vs. 64 bit structures are different */ | |
2192 | for (i = 0; i < NF_BR_NUMHOOKS; i++) | |
2193 | repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]); | |
2194 | ||
2195 | repl->num_counters = tmp.num_counters; | |
2196 | repl->counters = compat_ptr(tmp.counters); | |
2197 | repl->entries = compat_ptr(tmp.entries); | |
2198 | return 0; | |
2199 | } | |
2200 | ||
2201 | static int compat_do_replace(struct net *net, void __user *user, | |
2202 | unsigned int len) | |
2203 | { | |
2204 | int ret, i, countersize, size64; | |
2205 | struct ebt_table_info *newinfo; | |
2206 | struct ebt_replace tmp; | |
2207 | struct ebt_entries_buf_state state; | |
2208 | void *entries_tmp; | |
2209 | ||
2210 | ret = compat_copy_ebt_replace_from_user(&tmp, user, len); | |
90b89af7 FW |
2211 | if (ret) { |
2212 | /* try real handler in case userland supplied needed padding */ | |
2213 | if (ret == -EINVAL && do_replace(net, user, len) == 0) | |
2214 | ret = 0; | |
81e675c2 | 2215 | return ret; |
90b89af7 | 2216 | } |
81e675c2 FW |
2217 | |
2218 | countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids; | |
2219 | newinfo = vmalloc(sizeof(*newinfo) + countersize); | |
2220 | if (!newinfo) | |
2221 | return -ENOMEM; | |
2222 | ||
2223 | if (countersize) | |
2224 | memset(newinfo->counters, 0, countersize); | |
2225 | ||
2226 | memset(&state, 0, sizeof(state)); | |
2227 | ||
2228 | newinfo->entries = vmalloc(tmp.entries_size); | |
2229 | if (!newinfo->entries) { | |
2230 | ret = -ENOMEM; | |
2231 | goto free_newinfo; | |
2232 | } | |
2233 | if (copy_from_user( | |
2234 | newinfo->entries, tmp.entries, tmp.entries_size) != 0) { | |
2235 | ret = -EFAULT; | |
2236 | goto free_entries; | |
2237 | } | |
2238 | ||
2239 | entries_tmp = newinfo->entries; | |
2240 | ||
2241 | xt_compat_lock(NFPROTO_BRIDGE); | |
2242 | ||
2243 | ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state); | |
2244 | if (ret < 0) | |
2245 | goto out_unlock; | |
2246 | ||
2247 | pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n", | |
2248 | tmp.entries_size, state.buf_kern_offset, state.buf_user_offset, | |
2249 | xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size)); | |
2250 | ||
2251 | size64 = ret; | |
2252 | newinfo->entries = vmalloc(size64); | |
2253 | if (!newinfo->entries) { | |
2254 | vfree(entries_tmp); | |
2255 | ret = -ENOMEM; | |
2256 | goto out_unlock; | |
2257 | } | |
2258 | ||
2259 | memset(&state, 0, sizeof(state)); | |
2260 | state.buf_kern_start = newinfo->entries; | |
2261 | state.buf_kern_len = size64; | |
2262 | ||
2263 | ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state); | |
2264 | BUG_ON(ret < 0); /* parses same data again */ | |
2265 | ||
2266 | vfree(entries_tmp); | |
2267 | tmp.entries_size = size64; | |
2268 | ||
2269 | for (i = 0; i < NF_BR_NUMHOOKS; i++) { | |
2270 | char __user *usrptr; | |
2271 | if (tmp.hook_entry[i]) { | |
2272 | unsigned int delta; | |
2273 | usrptr = (char __user *) tmp.hook_entry[i]; | |
2274 | delta = usrptr - tmp.entries; | |
2275 | usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta); | |
2276 | tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr; | |
2277 | } | |
2278 | } | |
2279 | ||
2280 | xt_compat_flush_offsets(NFPROTO_BRIDGE); | |
2281 | xt_compat_unlock(NFPROTO_BRIDGE); | |
2282 | ||
2283 | ret = do_replace_finish(net, &tmp, newinfo); | |
2284 | if (ret == 0) | |
2285 | return ret; | |
2286 | free_entries: | |
2287 | vfree(newinfo->entries); | |
2288 | free_newinfo: | |
2289 | vfree(newinfo); | |
2290 | return ret; | |
2291 | out_unlock: | |
2292 | xt_compat_flush_offsets(NFPROTO_BRIDGE); | |
2293 | xt_compat_unlock(NFPROTO_BRIDGE); | |
2294 | goto free_entries; | |
2295 | } | |
2296 | ||
2297 | static int compat_update_counters(struct net *net, void __user *user, | |
2298 | unsigned int len) | |
2299 | { | |
2300 | struct compat_ebt_replace hlp; | |
2301 | ||
2302 | if (copy_from_user(&hlp, user, sizeof(hlp))) | |
2303 | return -EFAULT; | |
2304 | ||
90b89af7 | 2305 | /* try real handler in case userland supplied needed padding */ |
81e675c2 | 2306 | if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter)) |
90b89af7 | 2307 | return update_counters(net, user, len); |
81e675c2 FW |
2308 | |
2309 | return do_update_counters(net, hlp.name, compat_ptr(hlp.counters), | |
2310 | hlp.num_counters, user, len); | |
2311 | } | |
2312 | ||
2313 | static int compat_do_ebt_set_ctl(struct sock *sk, | |
2314 | int cmd, void __user *user, unsigned int len) | |
2315 | { | |
2316 | int ret; | |
2317 | ||
2318 | if (!capable(CAP_NET_ADMIN)) | |
2319 | return -EPERM; | |
2320 | ||
2321 | switch (cmd) { | |
2322 | case EBT_SO_SET_ENTRIES: | |
2323 | ret = compat_do_replace(sock_net(sk), user, len); | |
2324 | break; | |
2325 | case EBT_SO_SET_COUNTERS: | |
2326 | ret = compat_update_counters(sock_net(sk), user, len); | |
2327 | break; | |
2328 | default: | |
2329 | ret = -EINVAL; | |
2330 | } | |
2331 | return ret; | |
2332 | } | |
2333 | ||
2334 | static int compat_do_ebt_get_ctl(struct sock *sk, int cmd, | |
2335 | void __user *user, int *len) | |
2336 | { | |
2337 | int ret; | |
2338 | struct compat_ebt_replace tmp; | |
2339 | struct ebt_table *t; | |
2340 | ||
2341 | if (!capable(CAP_NET_ADMIN)) | |
2342 | return -EPERM; | |
2343 | ||
90b89af7 | 2344 | /* try real handler in case userland supplied needed padding */ |
81e675c2 FW |
2345 | if ((cmd == EBT_SO_GET_INFO || |
2346 | cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp)) | |
90b89af7 | 2347 | return do_ebt_get_ctl(sk, cmd, user, len); |
81e675c2 FW |
2348 | |
2349 | if (copy_from_user(&tmp, user, sizeof(tmp))) | |
2350 | return -EFAULT; | |
2351 | ||
2352 | t = find_table_lock(sock_net(sk), tmp.name, &ret, &ebt_mutex); | |
2353 | if (!t) | |
2354 | return ret; | |
2355 | ||
2356 | xt_compat_lock(NFPROTO_BRIDGE); | |
2357 | switch (cmd) { | |
2358 | case EBT_SO_GET_INFO: | |
2359 | tmp.nentries = t->private->nentries; | |
2360 | ret = compat_table_info(t->private, &tmp); | |
2361 | if (ret) | |
2362 | goto out; | |
2363 | tmp.valid_hooks = t->valid_hooks; | |
2364 | ||
2365 | if (copy_to_user(user, &tmp, *len) != 0) { | |
2366 | ret = -EFAULT; | |
2367 | break; | |
2368 | } | |
2369 | ret = 0; | |
2370 | break; | |
2371 | case EBT_SO_GET_INIT_INFO: | |
2372 | tmp.nentries = t->table->nentries; | |
2373 | tmp.entries_size = t->table->entries_size; | |
2374 | tmp.valid_hooks = t->table->valid_hooks; | |
2375 | ||
2376 | if (copy_to_user(user, &tmp, *len) != 0) { | |
2377 | ret = -EFAULT; | |
2378 | break; | |
2379 | } | |
2380 | ret = 0; | |
2381 | break; | |
2382 | case EBT_SO_GET_ENTRIES: | |
2383 | case EBT_SO_GET_INIT_ENTRIES: | |
90b89af7 FW |
2384 | /* |
2385 | * try real handler first in case of userland-side padding. | |
2386 | * in case we are dealing with an 'ordinary' 32 bit binary | |
2387 | * without 64bit compatibility padding, this will fail right | |
2388 | * after copy_from_user when the *len argument is validated. | |
2389 | * | |
2390 | * the compat_ variant needs to do one pass over the kernel | |
2391 | * data set to adjust for size differences before it the check. | |
2392 | */ | |
2393 | if (copy_everything_to_user(t, user, len, cmd) == 0) | |
2394 | ret = 0; | |
2395 | else | |
2396 | ret = compat_copy_everything_to_user(t, user, len, cmd); | |
81e675c2 FW |
2397 | break; |
2398 | default: | |
2399 | ret = -EINVAL; | |
2400 | } | |
2401 | out: | |
2402 | xt_compat_flush_offsets(NFPROTO_BRIDGE); | |
2403 | xt_compat_unlock(NFPROTO_BRIDGE); | |
2404 | mutex_unlock(&ebt_mutex); | |
2405 | return ret; | |
2406 | } | |
2407 | #endif | |
2408 | ||
1da177e4 | 2409 | static struct nf_sockopt_ops ebt_sockopts = |
74ca4e5a AM |
2410 | { |
2411 | .pf = PF_INET, | |
2412 | .set_optmin = EBT_BASE_CTL, | |
2413 | .set_optmax = EBT_SO_SET_MAX + 1, | |
2414 | .set = do_ebt_set_ctl, | |
81e675c2 FW |
2415 | #ifdef CONFIG_COMPAT |
2416 | .compat_set = compat_do_ebt_set_ctl, | |
2417 | #endif | |
74ca4e5a AM |
2418 | .get_optmin = EBT_BASE_CTL, |
2419 | .get_optmax = EBT_SO_GET_MAX + 1, | |
2420 | .get = do_ebt_get_ctl, | |
81e675c2 FW |
2421 | #ifdef CONFIG_COMPAT |
2422 | .compat_get = compat_do_ebt_get_ctl, | |
2423 | #endif | |
16fcec35 | 2424 | .owner = THIS_MODULE, |
1da177e4 LT |
2425 | }; |
2426 | ||
65b4b4e8 | 2427 | static int __init ebtables_init(void) |
1da177e4 LT |
2428 | { |
2429 | int ret; | |
2430 | ||
043ef46c JE |
2431 | ret = xt_register_target(&ebt_standard_target); |
2432 | if (ret < 0) | |
1da177e4 | 2433 | return ret; |
043ef46c JE |
2434 | ret = nf_register_sockopt(&ebt_sockopts); |
2435 | if (ret < 0) { | |
2436 | xt_unregister_target(&ebt_standard_target); | |
2437 | return ret; | |
2438 | } | |
1da177e4 | 2439 | |
a887c1c1 | 2440 | printk(KERN_INFO "Ebtables v2.0 registered\n"); |
1da177e4 LT |
2441 | return 0; |
2442 | } | |
2443 | ||
65b4b4e8 | 2444 | static void __exit ebtables_fini(void) |
1da177e4 LT |
2445 | { |
2446 | nf_unregister_sockopt(&ebt_sockopts); | |
043ef46c | 2447 | xt_unregister_target(&ebt_standard_target); |
a887c1c1 | 2448 | printk(KERN_INFO "Ebtables v2.0 unregistered\n"); |
1da177e4 LT |
2449 | } |
2450 | ||
2451 | EXPORT_SYMBOL(ebt_register_table); | |
2452 | EXPORT_SYMBOL(ebt_unregister_table); | |
1da177e4 | 2453 | EXPORT_SYMBOL(ebt_do_table); |
65b4b4e8 AM |
2454 | module_init(ebtables_init); |
2455 | module_exit(ebtables_fini); | |
1da177e4 | 2456 | MODULE_LICENSE("GPL"); |