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1 | /* | |
2 | * x_tables core - Backend for {ip,ip6,arp}_tables | |
3 | * | |
4 | * Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org> | |
5 | * | |
6 | * Based on existing ip_tables code which is | |
7 | * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling | |
8 | * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | * | |
14 | */ | |
15 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/socket.h> | |
19 | #include <linux/net.h> | |
20 | #include <linux/proc_fs.h> | |
21 | #include <linux/seq_file.h> | |
22 | #include <linux/string.h> | |
23 | #include <linux/vmalloc.h> | |
24 | #include <linux/mutex.h> | |
25 | #include <linux/mm.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/audit.h> | |
28 | #include <net/net_namespace.h> | |
29 | ||
30 | #include <linux/netfilter/x_tables.h> | |
31 | #include <linux/netfilter_arp.h> | |
32 | #include <linux/netfilter_ipv4/ip_tables.h> | |
33 | #include <linux/netfilter_ipv6/ip6_tables.h> | |
34 | #include <linux/netfilter_arp/arp_tables.h> | |
35 | ||
36 | MODULE_LICENSE("GPL"); | |
37 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
38 | MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module"); | |
39 | ||
40 | #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1)) | |
41 | ||
42 | struct compat_delta { | |
43 | unsigned int offset; /* offset in kernel */ | |
44 | int delta; /* delta in 32bit user land */ | |
45 | }; | |
46 | ||
47 | struct xt_af { | |
48 | struct mutex mutex; | |
49 | struct list_head match; | |
50 | struct list_head target; | |
51 | #ifdef CONFIG_COMPAT | |
52 | struct mutex compat_mutex; | |
53 | struct compat_delta *compat_tab; | |
54 | unsigned int number; /* number of slots in compat_tab[] */ | |
55 | unsigned int cur; /* number of used slots in compat_tab[] */ | |
56 | #endif | |
57 | }; | |
58 | ||
59 | static struct xt_af *xt; | |
60 | ||
61 | static const char *const xt_prefix[NFPROTO_NUMPROTO] = { | |
62 | [NFPROTO_UNSPEC] = "x", | |
63 | [NFPROTO_IPV4] = "ip", | |
64 | [NFPROTO_ARP] = "arp", | |
65 | [NFPROTO_BRIDGE] = "eb", | |
66 | [NFPROTO_IPV6] = "ip6", | |
67 | }; | |
68 | ||
69 | /* Allow this many total (re)entries. */ | |
70 | static const unsigned int xt_jumpstack_multiplier = 2; | |
71 | ||
72 | /* Registration hooks for targets. */ | |
73 | int | |
74 | xt_register_target(struct xt_target *target) | |
75 | { | |
76 | u_int8_t af = target->family; | |
77 | int ret; | |
78 | ||
79 | ret = mutex_lock_interruptible(&xt[af].mutex); | |
80 | if (ret != 0) | |
81 | return ret; | |
82 | list_add(&target->list, &xt[af].target); | |
83 | mutex_unlock(&xt[af].mutex); | |
84 | return ret; | |
85 | } | |
86 | EXPORT_SYMBOL(xt_register_target); | |
87 | ||
88 | void | |
89 | xt_unregister_target(struct xt_target *target) | |
90 | { | |
91 | u_int8_t af = target->family; | |
92 | ||
93 | mutex_lock(&xt[af].mutex); | |
94 | list_del(&target->list); | |
95 | mutex_unlock(&xt[af].mutex); | |
96 | } | |
97 | EXPORT_SYMBOL(xt_unregister_target); | |
98 | ||
99 | int | |
100 | xt_register_targets(struct xt_target *target, unsigned int n) | |
101 | { | |
102 | unsigned int i; | |
103 | int err = 0; | |
104 | ||
105 | for (i = 0; i < n; i++) { | |
106 | err = xt_register_target(&target[i]); | |
107 | if (err) | |
108 | goto err; | |
109 | } | |
110 | return err; | |
111 | ||
112 | err: | |
113 | if (i > 0) | |
114 | xt_unregister_targets(target, i); | |
115 | return err; | |
116 | } | |
117 | EXPORT_SYMBOL(xt_register_targets); | |
118 | ||
119 | void | |
120 | xt_unregister_targets(struct xt_target *target, unsigned int n) | |
121 | { | |
122 | while (n-- > 0) | |
123 | xt_unregister_target(&target[n]); | |
124 | } | |
125 | EXPORT_SYMBOL(xt_unregister_targets); | |
126 | ||
127 | int | |
128 | xt_register_match(struct xt_match *match) | |
129 | { | |
130 | u_int8_t af = match->family; | |
131 | int ret; | |
132 | ||
133 | ret = mutex_lock_interruptible(&xt[af].mutex); | |
134 | if (ret != 0) | |
135 | return ret; | |
136 | ||
137 | list_add(&match->list, &xt[af].match); | |
138 | mutex_unlock(&xt[af].mutex); | |
139 | ||
140 | return ret; | |
141 | } | |
142 | EXPORT_SYMBOL(xt_register_match); | |
143 | ||
144 | void | |
145 | xt_unregister_match(struct xt_match *match) | |
146 | { | |
147 | u_int8_t af = match->family; | |
148 | ||
149 | mutex_lock(&xt[af].mutex); | |
150 | list_del(&match->list); | |
151 | mutex_unlock(&xt[af].mutex); | |
152 | } | |
153 | EXPORT_SYMBOL(xt_unregister_match); | |
154 | ||
155 | int | |
156 | xt_register_matches(struct xt_match *match, unsigned int n) | |
157 | { | |
158 | unsigned int i; | |
159 | int err = 0; | |
160 | ||
161 | for (i = 0; i < n; i++) { | |
162 | err = xt_register_match(&match[i]); | |
163 | if (err) | |
164 | goto err; | |
165 | } | |
166 | return err; | |
167 | ||
168 | err: | |
169 | if (i > 0) | |
170 | xt_unregister_matches(match, i); | |
171 | return err; | |
172 | } | |
173 | EXPORT_SYMBOL(xt_register_matches); | |
174 | ||
175 | void | |
176 | xt_unregister_matches(struct xt_match *match, unsigned int n) | |
177 | { | |
178 | while (n-- > 0) | |
179 | xt_unregister_match(&match[n]); | |
180 | } | |
181 | EXPORT_SYMBOL(xt_unregister_matches); | |
182 | ||
183 | ||
184 | /* | |
185 | * These are weird, but module loading must not be done with mutex | |
186 | * held (since they will register), and we have to have a single | |
187 | * function to use. | |
188 | */ | |
189 | ||
190 | /* Find match, grabs ref. Returns ERR_PTR() on error. */ | |
191 | struct xt_match *xt_find_match(u8 af, const char *name, u8 revision) | |
192 | { | |
193 | struct xt_match *m; | |
194 | int err = -ENOENT; | |
195 | ||
196 | if (mutex_lock_interruptible(&xt[af].mutex) != 0) | |
197 | return ERR_PTR(-EINTR); | |
198 | ||
199 | list_for_each_entry(m, &xt[af].match, list) { | |
200 | if (strcmp(m->name, name) == 0) { | |
201 | if (m->revision == revision) { | |
202 | if (try_module_get(m->me)) { | |
203 | mutex_unlock(&xt[af].mutex); | |
204 | return m; | |
205 | } | |
206 | } else | |
207 | err = -EPROTOTYPE; /* Found something. */ | |
208 | } | |
209 | } | |
210 | mutex_unlock(&xt[af].mutex); | |
211 | ||
212 | if (af != NFPROTO_UNSPEC) | |
213 | /* Try searching again in the family-independent list */ | |
214 | return xt_find_match(NFPROTO_UNSPEC, name, revision); | |
215 | ||
216 | return ERR_PTR(err); | |
217 | } | |
218 | EXPORT_SYMBOL(xt_find_match); | |
219 | ||
220 | struct xt_match * | |
221 | xt_request_find_match(uint8_t nfproto, const char *name, uint8_t revision) | |
222 | { | |
223 | struct xt_match *match; | |
224 | ||
225 | match = xt_find_match(nfproto, name, revision); | |
226 | if (IS_ERR(match)) { | |
227 | request_module("%st_%s", xt_prefix[nfproto], name); | |
228 | match = xt_find_match(nfproto, name, revision); | |
229 | } | |
230 | ||
231 | return match; | |
232 | } | |
233 | EXPORT_SYMBOL_GPL(xt_request_find_match); | |
234 | ||
235 | /* Find target, grabs ref. Returns ERR_PTR() on error. */ | |
236 | struct xt_target *xt_find_target(u8 af, const char *name, u8 revision) | |
237 | { | |
238 | struct xt_target *t; | |
239 | int err = -ENOENT; | |
240 | ||
241 | if (mutex_lock_interruptible(&xt[af].mutex) != 0) | |
242 | return ERR_PTR(-EINTR); | |
243 | ||
244 | list_for_each_entry(t, &xt[af].target, list) { | |
245 | if (strcmp(t->name, name) == 0) { | |
246 | if (t->revision == revision) { | |
247 | if (try_module_get(t->me)) { | |
248 | mutex_unlock(&xt[af].mutex); | |
249 | return t; | |
250 | } | |
251 | } else | |
252 | err = -EPROTOTYPE; /* Found something. */ | |
253 | } | |
254 | } | |
255 | mutex_unlock(&xt[af].mutex); | |
256 | ||
257 | if (af != NFPROTO_UNSPEC) | |
258 | /* Try searching again in the family-independent list */ | |
259 | return xt_find_target(NFPROTO_UNSPEC, name, revision); | |
260 | ||
261 | return ERR_PTR(err); | |
262 | } | |
263 | EXPORT_SYMBOL(xt_find_target); | |
264 | ||
265 | struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision) | |
266 | { | |
267 | struct xt_target *target; | |
268 | ||
269 | target = xt_find_target(af, name, revision); | |
270 | if (IS_ERR(target)) { | |
271 | request_module("%st_%s", xt_prefix[af], name); | |
272 | target = xt_find_target(af, name, revision); | |
273 | } | |
274 | ||
275 | return target; | |
276 | } | |
277 | EXPORT_SYMBOL_GPL(xt_request_find_target); | |
278 | ||
279 | static int match_revfn(u8 af, const char *name, u8 revision, int *bestp) | |
280 | { | |
281 | const struct xt_match *m; | |
282 | int have_rev = 0; | |
283 | ||
284 | list_for_each_entry(m, &xt[af].match, list) { | |
285 | if (strcmp(m->name, name) == 0) { | |
286 | if (m->revision > *bestp) | |
287 | *bestp = m->revision; | |
288 | if (m->revision == revision) | |
289 | have_rev = 1; | |
290 | } | |
291 | } | |
292 | ||
293 | if (af != NFPROTO_UNSPEC && !have_rev) | |
294 | return match_revfn(NFPROTO_UNSPEC, name, revision, bestp); | |
295 | ||
296 | return have_rev; | |
297 | } | |
298 | ||
299 | static int target_revfn(u8 af, const char *name, u8 revision, int *bestp) | |
300 | { | |
301 | const struct xt_target *t; | |
302 | int have_rev = 0; | |
303 | ||
304 | list_for_each_entry(t, &xt[af].target, list) { | |
305 | if (strcmp(t->name, name) == 0) { | |
306 | if (t->revision > *bestp) | |
307 | *bestp = t->revision; | |
308 | if (t->revision == revision) | |
309 | have_rev = 1; | |
310 | } | |
311 | } | |
312 | ||
313 | if (af != NFPROTO_UNSPEC && !have_rev) | |
314 | return target_revfn(NFPROTO_UNSPEC, name, revision, bestp); | |
315 | ||
316 | return have_rev; | |
317 | } | |
318 | ||
319 | /* Returns true or false (if no such extension at all) */ | |
320 | int xt_find_revision(u8 af, const char *name, u8 revision, int target, | |
321 | int *err) | |
322 | { | |
323 | int have_rev, best = -1; | |
324 | ||
325 | if (mutex_lock_interruptible(&xt[af].mutex) != 0) { | |
326 | *err = -EINTR; | |
327 | return 1; | |
328 | } | |
329 | if (target == 1) | |
330 | have_rev = target_revfn(af, name, revision, &best); | |
331 | else | |
332 | have_rev = match_revfn(af, name, revision, &best); | |
333 | mutex_unlock(&xt[af].mutex); | |
334 | ||
335 | /* Nothing at all? Return 0 to try loading module. */ | |
336 | if (best == -1) { | |
337 | *err = -ENOENT; | |
338 | return 0; | |
339 | } | |
340 | ||
341 | *err = best; | |
342 | if (!have_rev) | |
343 | *err = -EPROTONOSUPPORT; | |
344 | return 1; | |
345 | } | |
346 | EXPORT_SYMBOL_GPL(xt_find_revision); | |
347 | ||
348 | static char * | |
349 | textify_hooks(char *buf, size_t size, unsigned int mask, uint8_t nfproto) | |
350 | { | |
351 | static const char *const inetbr_names[] = { | |
352 | "PREROUTING", "INPUT", "FORWARD", | |
353 | "OUTPUT", "POSTROUTING", "BROUTING", | |
354 | }; | |
355 | static const char *const arp_names[] = { | |
356 | "INPUT", "FORWARD", "OUTPUT", | |
357 | }; | |
358 | const char *const *names; | |
359 | unsigned int i, max; | |
360 | char *p = buf; | |
361 | bool np = false; | |
362 | int res; | |
363 | ||
364 | names = (nfproto == NFPROTO_ARP) ? arp_names : inetbr_names; | |
365 | max = (nfproto == NFPROTO_ARP) ? ARRAY_SIZE(arp_names) : | |
366 | ARRAY_SIZE(inetbr_names); | |
367 | *p = '\0'; | |
368 | for (i = 0; i < max; ++i) { | |
369 | if (!(mask & (1 << i))) | |
370 | continue; | |
371 | res = snprintf(p, size, "%s%s", np ? "/" : "", names[i]); | |
372 | if (res > 0) { | |
373 | size -= res; | |
374 | p += res; | |
375 | } | |
376 | np = true; | |
377 | } | |
378 | ||
379 | return buf; | |
380 | } | |
381 | ||
382 | int xt_check_match(struct xt_mtchk_param *par, | |
383 | unsigned int size, u_int8_t proto, bool inv_proto) | |
384 | { | |
385 | int ret; | |
386 | ||
387 | if (XT_ALIGN(par->match->matchsize) != size && | |
388 | par->match->matchsize != -1) { | |
389 | /* | |
390 | * ebt_among is exempt from centralized matchsize checking | |
391 | * because it uses a dynamic-size data set. | |
392 | */ | |
393 | pr_err("%s_tables: %s.%u match: invalid size " | |
394 | "%u (kernel) != (user) %u\n", | |
395 | xt_prefix[par->family], par->match->name, | |
396 | par->match->revision, | |
397 | XT_ALIGN(par->match->matchsize), size); | |
398 | return -EINVAL; | |
399 | } | |
400 | if (par->match->table != NULL && | |
401 | strcmp(par->match->table, par->table) != 0) { | |
402 | pr_err("%s_tables: %s match: only valid in %s table, not %s\n", | |
403 | xt_prefix[par->family], par->match->name, | |
404 | par->match->table, par->table); | |
405 | return -EINVAL; | |
406 | } | |
407 | if (par->match->hooks && (par->hook_mask & ~par->match->hooks) != 0) { | |
408 | char used[64], allow[64]; | |
409 | ||
410 | pr_err("%s_tables: %s match: used from hooks %s, but only " | |
411 | "valid from %s\n", | |
412 | xt_prefix[par->family], par->match->name, | |
413 | textify_hooks(used, sizeof(used), par->hook_mask, | |
414 | par->family), | |
415 | textify_hooks(allow, sizeof(allow), par->match->hooks, | |
416 | par->family)); | |
417 | return -EINVAL; | |
418 | } | |
419 | if (par->match->proto && (par->match->proto != proto || inv_proto)) { | |
420 | pr_err("%s_tables: %s match: only valid for protocol %u\n", | |
421 | xt_prefix[par->family], par->match->name, | |
422 | par->match->proto); | |
423 | return -EINVAL; | |
424 | } | |
425 | if (par->match->checkentry != NULL) { | |
426 | ret = par->match->checkentry(par); | |
427 | if (ret < 0) | |
428 | return ret; | |
429 | else if (ret > 0) | |
430 | /* Flag up potential errors. */ | |
431 | return -EIO; | |
432 | } | |
433 | return 0; | |
434 | } | |
435 | EXPORT_SYMBOL_GPL(xt_check_match); | |
436 | ||
437 | #ifdef CONFIG_COMPAT | |
438 | int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta) | |
439 | { | |
440 | struct xt_af *xp = &xt[af]; | |
441 | ||
442 | if (!xp->compat_tab) { | |
443 | if (!xp->number) | |
444 | return -EINVAL; | |
445 | xp->compat_tab = vmalloc(sizeof(struct compat_delta) * xp->number); | |
446 | if (!xp->compat_tab) | |
447 | return -ENOMEM; | |
448 | xp->cur = 0; | |
449 | } | |
450 | ||
451 | if (xp->cur >= xp->number) | |
452 | return -EINVAL; | |
453 | ||
454 | if (xp->cur) | |
455 | delta += xp->compat_tab[xp->cur - 1].delta; | |
456 | xp->compat_tab[xp->cur].offset = offset; | |
457 | xp->compat_tab[xp->cur].delta = delta; | |
458 | xp->cur++; | |
459 | return 0; | |
460 | } | |
461 | EXPORT_SYMBOL_GPL(xt_compat_add_offset); | |
462 | ||
463 | void xt_compat_flush_offsets(u_int8_t af) | |
464 | { | |
465 | if (xt[af].compat_tab) { | |
466 | vfree(xt[af].compat_tab); | |
467 | xt[af].compat_tab = NULL; | |
468 | xt[af].number = 0; | |
469 | xt[af].cur = 0; | |
470 | } | |
471 | } | |
472 | EXPORT_SYMBOL_GPL(xt_compat_flush_offsets); | |
473 | ||
474 | int xt_compat_calc_jump(u_int8_t af, unsigned int offset) | |
475 | { | |
476 | struct compat_delta *tmp = xt[af].compat_tab; | |
477 | int mid, left = 0, right = xt[af].cur - 1; | |
478 | ||
479 | while (left <= right) { | |
480 | mid = (left + right) >> 1; | |
481 | if (offset > tmp[mid].offset) | |
482 | left = mid + 1; | |
483 | else if (offset < tmp[mid].offset) | |
484 | right = mid - 1; | |
485 | else | |
486 | return mid ? tmp[mid - 1].delta : 0; | |
487 | } | |
488 | return left ? tmp[left - 1].delta : 0; | |
489 | } | |
490 | EXPORT_SYMBOL_GPL(xt_compat_calc_jump); | |
491 | ||
492 | void xt_compat_init_offsets(u_int8_t af, unsigned int number) | |
493 | { | |
494 | xt[af].number = number; | |
495 | xt[af].cur = 0; | |
496 | } | |
497 | EXPORT_SYMBOL(xt_compat_init_offsets); | |
498 | ||
499 | int xt_compat_match_offset(const struct xt_match *match) | |
500 | { | |
501 | u_int16_t csize = match->compatsize ? : match->matchsize; | |
502 | return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize); | |
503 | } | |
504 | EXPORT_SYMBOL_GPL(xt_compat_match_offset); | |
505 | ||
506 | int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr, | |
507 | unsigned int *size) | |
508 | { | |
509 | const struct xt_match *match = m->u.kernel.match; | |
510 | struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m; | |
511 | int pad, off = xt_compat_match_offset(match); | |
512 | u_int16_t msize = cm->u.user.match_size; | |
513 | ||
514 | m = *dstptr; | |
515 | memcpy(m, cm, sizeof(*cm)); | |
516 | if (match->compat_from_user) | |
517 | match->compat_from_user(m->data, cm->data); | |
518 | else | |
519 | memcpy(m->data, cm->data, msize - sizeof(*cm)); | |
520 | pad = XT_ALIGN(match->matchsize) - match->matchsize; | |
521 | if (pad > 0) | |
522 | memset(m->data + match->matchsize, 0, pad); | |
523 | ||
524 | msize += off; | |
525 | m->u.user.match_size = msize; | |
526 | ||
527 | *size += off; | |
528 | *dstptr += msize; | |
529 | return 0; | |
530 | } | |
531 | EXPORT_SYMBOL_GPL(xt_compat_match_from_user); | |
532 | ||
533 | int xt_compat_match_to_user(const struct xt_entry_match *m, | |
534 | void __user **dstptr, unsigned int *size) | |
535 | { | |
536 | const struct xt_match *match = m->u.kernel.match; | |
537 | struct compat_xt_entry_match __user *cm = *dstptr; | |
538 | int off = xt_compat_match_offset(match); | |
539 | u_int16_t msize = m->u.user.match_size - off; | |
540 | ||
541 | if (copy_to_user(cm, m, sizeof(*cm)) || | |
542 | put_user(msize, &cm->u.user.match_size) || | |
543 | copy_to_user(cm->u.user.name, m->u.kernel.match->name, | |
544 | strlen(m->u.kernel.match->name) + 1)) | |
545 | return -EFAULT; | |
546 | ||
547 | if (match->compat_to_user) { | |
548 | if (match->compat_to_user((void __user *)cm->data, m->data)) | |
549 | return -EFAULT; | |
550 | } else { | |
551 | if (copy_to_user(cm->data, m->data, msize - sizeof(*cm))) | |
552 | return -EFAULT; | |
553 | } | |
554 | ||
555 | *size -= off; | |
556 | *dstptr += msize; | |
557 | return 0; | |
558 | } | |
559 | EXPORT_SYMBOL_GPL(xt_compat_match_to_user); | |
560 | #endif /* CONFIG_COMPAT */ | |
561 | ||
562 | int xt_check_target(struct xt_tgchk_param *par, | |
563 | unsigned int size, u_int8_t proto, bool inv_proto) | |
564 | { | |
565 | int ret; | |
566 | ||
567 | if (XT_ALIGN(par->target->targetsize) != size) { | |
568 | pr_err("%s_tables: %s.%u target: invalid size " | |
569 | "%u (kernel) != (user) %u\n", | |
570 | xt_prefix[par->family], par->target->name, | |
571 | par->target->revision, | |
572 | XT_ALIGN(par->target->targetsize), size); | |
573 | return -EINVAL; | |
574 | } | |
575 | if (par->target->table != NULL && | |
576 | strcmp(par->target->table, par->table) != 0) { | |
577 | pr_err("%s_tables: %s target: only valid in %s table, not %s\n", | |
578 | xt_prefix[par->family], par->target->name, | |
579 | par->target->table, par->table); | |
580 | return -EINVAL; | |
581 | } | |
582 | if (par->target->hooks && (par->hook_mask & ~par->target->hooks) != 0) { | |
583 | char used[64], allow[64]; | |
584 | ||
585 | pr_err("%s_tables: %s target: used from hooks %s, but only " | |
586 | "usable from %s\n", | |
587 | xt_prefix[par->family], par->target->name, | |
588 | textify_hooks(used, sizeof(used), par->hook_mask, | |
589 | par->family), | |
590 | textify_hooks(allow, sizeof(allow), par->target->hooks, | |
591 | par->family)); | |
592 | return -EINVAL; | |
593 | } | |
594 | if (par->target->proto && (par->target->proto != proto || inv_proto)) { | |
595 | pr_err("%s_tables: %s target: only valid for protocol %u\n", | |
596 | xt_prefix[par->family], par->target->name, | |
597 | par->target->proto); | |
598 | return -EINVAL; | |
599 | } | |
600 | if (par->target->checkentry != NULL) { | |
601 | ret = par->target->checkentry(par); | |
602 | if (ret < 0) | |
603 | return ret; | |
604 | else if (ret > 0) | |
605 | /* Flag up potential errors. */ | |
606 | return -EIO; | |
607 | } | |
608 | return 0; | |
609 | } | |
610 | EXPORT_SYMBOL_GPL(xt_check_target); | |
611 | ||
612 | #ifdef CONFIG_COMPAT | |
613 | int xt_compat_target_offset(const struct xt_target *target) | |
614 | { | |
615 | u_int16_t csize = target->compatsize ? : target->targetsize; | |
616 | return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize); | |
617 | } | |
618 | EXPORT_SYMBOL_GPL(xt_compat_target_offset); | |
619 | ||
620 | void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr, | |
621 | unsigned int *size) | |
622 | { | |
623 | const struct xt_target *target = t->u.kernel.target; | |
624 | struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t; | |
625 | int pad, off = xt_compat_target_offset(target); | |
626 | u_int16_t tsize = ct->u.user.target_size; | |
627 | ||
628 | t = *dstptr; | |
629 | memcpy(t, ct, sizeof(*ct)); | |
630 | if (target->compat_from_user) | |
631 | target->compat_from_user(t->data, ct->data); | |
632 | else | |
633 | memcpy(t->data, ct->data, tsize - sizeof(*ct)); | |
634 | pad = XT_ALIGN(target->targetsize) - target->targetsize; | |
635 | if (pad > 0) | |
636 | memset(t->data + target->targetsize, 0, pad); | |
637 | ||
638 | tsize += off; | |
639 | t->u.user.target_size = tsize; | |
640 | ||
641 | *size += off; | |
642 | *dstptr += tsize; | |
643 | } | |
644 | EXPORT_SYMBOL_GPL(xt_compat_target_from_user); | |
645 | ||
646 | int xt_compat_target_to_user(const struct xt_entry_target *t, | |
647 | void __user **dstptr, unsigned int *size) | |
648 | { | |
649 | const struct xt_target *target = t->u.kernel.target; | |
650 | struct compat_xt_entry_target __user *ct = *dstptr; | |
651 | int off = xt_compat_target_offset(target); | |
652 | u_int16_t tsize = t->u.user.target_size - off; | |
653 | ||
654 | if (copy_to_user(ct, t, sizeof(*ct)) || | |
655 | put_user(tsize, &ct->u.user.target_size) || | |
656 | copy_to_user(ct->u.user.name, t->u.kernel.target->name, | |
657 | strlen(t->u.kernel.target->name) + 1)) | |
658 | return -EFAULT; | |
659 | ||
660 | if (target->compat_to_user) { | |
661 | if (target->compat_to_user((void __user *)ct->data, t->data)) | |
662 | return -EFAULT; | |
663 | } else { | |
664 | if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct))) | |
665 | return -EFAULT; | |
666 | } | |
667 | ||
668 | *size -= off; | |
669 | *dstptr += tsize; | |
670 | return 0; | |
671 | } | |
672 | EXPORT_SYMBOL_GPL(xt_compat_target_to_user); | |
673 | #endif | |
674 | ||
675 | struct xt_table_info *xt_alloc_table_info(unsigned int size) | |
676 | { | |
677 | struct xt_table_info *newinfo; | |
678 | int cpu; | |
679 | ||
680 | /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */ | |
681 | if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages) | |
682 | return NULL; | |
683 | ||
684 | newinfo = kzalloc(XT_TABLE_INFO_SZ, GFP_KERNEL); | |
685 | if (!newinfo) | |
686 | return NULL; | |
687 | ||
688 | newinfo->size = size; | |
689 | ||
690 | for_each_possible_cpu(cpu) { | |
691 | if (size <= PAGE_SIZE) | |
692 | newinfo->entries[cpu] = kmalloc_node(size, | |
693 | GFP_KERNEL, | |
694 | cpu_to_node(cpu)); | |
695 | else | |
696 | newinfo->entries[cpu] = vmalloc_node(size, | |
697 | cpu_to_node(cpu)); | |
698 | ||
699 | if (newinfo->entries[cpu] == NULL) { | |
700 | xt_free_table_info(newinfo); | |
701 | return NULL; | |
702 | } | |
703 | } | |
704 | ||
705 | return newinfo; | |
706 | } | |
707 | EXPORT_SYMBOL(xt_alloc_table_info); | |
708 | ||
709 | void xt_free_table_info(struct xt_table_info *info) | |
710 | { | |
711 | int cpu; | |
712 | ||
713 | for_each_possible_cpu(cpu) { | |
714 | if (info->size <= PAGE_SIZE) | |
715 | kfree(info->entries[cpu]); | |
716 | else | |
717 | vfree(info->entries[cpu]); | |
718 | } | |
719 | ||
720 | if (info->jumpstack != NULL) { | |
721 | if (sizeof(void *) * info->stacksize > PAGE_SIZE) { | |
722 | for_each_possible_cpu(cpu) | |
723 | vfree(info->jumpstack[cpu]); | |
724 | } else { | |
725 | for_each_possible_cpu(cpu) | |
726 | kfree(info->jumpstack[cpu]); | |
727 | } | |
728 | } | |
729 | ||
730 | if (sizeof(void **) * nr_cpu_ids > PAGE_SIZE) | |
731 | vfree(info->jumpstack); | |
732 | else | |
733 | kfree(info->jumpstack); | |
734 | ||
735 | free_percpu(info->stackptr); | |
736 | ||
737 | kfree(info); | |
738 | } | |
739 | EXPORT_SYMBOL(xt_free_table_info); | |
740 | ||
741 | /* Find table by name, grabs mutex & ref. Returns ERR_PTR() on error. */ | |
742 | struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af, | |
743 | const char *name) | |
744 | { | |
745 | struct xt_table *t; | |
746 | ||
747 | if (mutex_lock_interruptible(&xt[af].mutex) != 0) | |
748 | return ERR_PTR(-EINTR); | |
749 | ||
750 | list_for_each_entry(t, &net->xt.tables[af], list) | |
751 | if (strcmp(t->name, name) == 0 && try_module_get(t->me)) | |
752 | return t; | |
753 | mutex_unlock(&xt[af].mutex); | |
754 | return NULL; | |
755 | } | |
756 | EXPORT_SYMBOL_GPL(xt_find_table_lock); | |
757 | ||
758 | void xt_table_unlock(struct xt_table *table) | |
759 | { | |
760 | mutex_unlock(&xt[table->af].mutex); | |
761 | } | |
762 | EXPORT_SYMBOL_GPL(xt_table_unlock); | |
763 | ||
764 | #ifdef CONFIG_COMPAT | |
765 | void xt_compat_lock(u_int8_t af) | |
766 | { | |
767 | mutex_lock(&xt[af].compat_mutex); | |
768 | } | |
769 | EXPORT_SYMBOL_GPL(xt_compat_lock); | |
770 | ||
771 | void xt_compat_unlock(u_int8_t af) | |
772 | { | |
773 | mutex_unlock(&xt[af].compat_mutex); | |
774 | } | |
775 | EXPORT_SYMBOL_GPL(xt_compat_unlock); | |
776 | #endif | |
777 | ||
778 | DEFINE_PER_CPU(seqcount_t, xt_recseq); | |
779 | EXPORT_PER_CPU_SYMBOL_GPL(xt_recseq); | |
780 | ||
781 | static int xt_jumpstack_alloc(struct xt_table_info *i) | |
782 | { | |
783 | unsigned int size; | |
784 | int cpu; | |
785 | ||
786 | i->stackptr = alloc_percpu(unsigned int); | |
787 | if (i->stackptr == NULL) | |
788 | return -ENOMEM; | |
789 | ||
790 | size = sizeof(void **) * nr_cpu_ids; | |
791 | if (size > PAGE_SIZE) | |
792 | i->jumpstack = vzalloc(size); | |
793 | else | |
794 | i->jumpstack = kzalloc(size, GFP_KERNEL); | |
795 | if (i->jumpstack == NULL) | |
796 | return -ENOMEM; | |
797 | ||
798 | i->stacksize *= xt_jumpstack_multiplier; | |
799 | size = sizeof(void *) * i->stacksize; | |
800 | for_each_possible_cpu(cpu) { | |
801 | if (size > PAGE_SIZE) | |
802 | i->jumpstack[cpu] = vmalloc_node(size, | |
803 | cpu_to_node(cpu)); | |
804 | else | |
805 | i->jumpstack[cpu] = kmalloc_node(size, | |
806 | GFP_KERNEL, cpu_to_node(cpu)); | |
807 | if (i->jumpstack[cpu] == NULL) | |
808 | /* | |
809 | * Freeing will be done later on by the callers. The | |
810 | * chain is: xt_replace_table -> __do_replace -> | |
811 | * do_replace -> xt_free_table_info. | |
812 | */ | |
813 | return -ENOMEM; | |
814 | } | |
815 | ||
816 | return 0; | |
817 | } | |
818 | ||
819 | struct xt_table_info * | |
820 | xt_replace_table(struct xt_table *table, | |
821 | unsigned int num_counters, | |
822 | struct xt_table_info *newinfo, | |
823 | int *error) | |
824 | { | |
825 | struct xt_table_info *private; | |
826 | int ret; | |
827 | ||
828 | ret = xt_jumpstack_alloc(newinfo); | |
829 | if (ret < 0) { | |
830 | *error = ret; | |
831 | return NULL; | |
832 | } | |
833 | ||
834 | /* Do the substitution. */ | |
835 | local_bh_disable(); | |
836 | private = table->private; | |
837 | ||
838 | /* Check inside lock: is the old number correct? */ | |
839 | if (num_counters != private->number) { | |
840 | pr_debug("num_counters != table->private->number (%u/%u)\n", | |
841 | num_counters, private->number); | |
842 | local_bh_enable(); | |
843 | *error = -EAGAIN; | |
844 | return NULL; | |
845 | } | |
846 | ||
847 | table->private = newinfo; | |
848 | newinfo->initial_entries = private->initial_entries; | |
849 | ||
850 | /* | |
851 | * Even though table entries have now been swapped, other CPU's | |
852 | * may still be using the old entries. This is okay, because | |
853 | * resynchronization happens because of the locking done | |
854 | * during the get_counters() routine. | |
855 | */ | |
856 | local_bh_enable(); | |
857 | ||
858 | #ifdef CONFIG_AUDIT | |
859 | if (audit_enabled) { | |
860 | struct audit_buffer *ab; | |
861 | ||
862 | ab = audit_log_start(current->audit_context, GFP_KERNEL, | |
863 | AUDIT_NETFILTER_CFG); | |
864 | if (ab) { | |
865 | audit_log_format(ab, "table=%s family=%u entries=%u", | |
866 | table->name, table->af, | |
867 | private->number); | |
868 | audit_log_end(ab); | |
869 | } | |
870 | } | |
871 | #endif | |
872 | ||
873 | return private; | |
874 | } | |
875 | EXPORT_SYMBOL_GPL(xt_replace_table); | |
876 | ||
877 | struct xt_table *xt_register_table(struct net *net, | |
878 | const struct xt_table *input_table, | |
879 | struct xt_table_info *bootstrap, | |
880 | struct xt_table_info *newinfo) | |
881 | { | |
882 | int ret; | |
883 | struct xt_table_info *private; | |
884 | struct xt_table *t, *table; | |
885 | ||
886 | /* Don't add one object to multiple lists. */ | |
887 | table = kmemdup(input_table, sizeof(struct xt_table), GFP_KERNEL); | |
888 | if (!table) { | |
889 | ret = -ENOMEM; | |
890 | goto out; | |
891 | } | |
892 | ||
893 | ret = mutex_lock_interruptible(&xt[table->af].mutex); | |
894 | if (ret != 0) | |
895 | goto out_free; | |
896 | ||
897 | /* Don't autoload: we'd eat our tail... */ | |
898 | list_for_each_entry(t, &net->xt.tables[table->af], list) { | |
899 | if (strcmp(t->name, table->name) == 0) { | |
900 | ret = -EEXIST; | |
901 | goto unlock; | |
902 | } | |
903 | } | |
904 | ||
905 | /* Simplifies replace_table code. */ | |
906 | table->private = bootstrap; | |
907 | ||
908 | if (!xt_replace_table(table, 0, newinfo, &ret)) | |
909 | goto unlock; | |
910 | ||
911 | private = table->private; | |
912 | pr_debug("table->private->number = %u\n", private->number); | |
913 | ||
914 | /* save number of initial entries */ | |
915 | private->initial_entries = private->number; | |
916 | ||
917 | list_add(&table->list, &net->xt.tables[table->af]); | |
918 | mutex_unlock(&xt[table->af].mutex); | |
919 | return table; | |
920 | ||
921 | unlock: | |
922 | mutex_unlock(&xt[table->af].mutex); | |
923 | out_free: | |
924 | kfree(table); | |
925 | out: | |
926 | return ERR_PTR(ret); | |
927 | } | |
928 | EXPORT_SYMBOL_GPL(xt_register_table); | |
929 | ||
930 | void *xt_unregister_table(struct xt_table *table) | |
931 | { | |
932 | struct xt_table_info *private; | |
933 | ||
934 | mutex_lock(&xt[table->af].mutex); | |
935 | private = table->private; | |
936 | list_del(&table->list); | |
937 | mutex_unlock(&xt[table->af].mutex); | |
938 | kfree(table); | |
939 | ||
940 | return private; | |
941 | } | |
942 | EXPORT_SYMBOL_GPL(xt_unregister_table); | |
943 | ||
944 | #ifdef CONFIG_PROC_FS | |
945 | struct xt_names_priv { | |
946 | struct seq_net_private p; | |
947 | u_int8_t af; | |
948 | }; | |
949 | static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos) | |
950 | { | |
951 | struct xt_names_priv *priv = seq->private; | |
952 | struct net *net = seq_file_net(seq); | |
953 | u_int8_t af = priv->af; | |
954 | ||
955 | mutex_lock(&xt[af].mutex); | |
956 | return seq_list_start(&net->xt.tables[af], *pos); | |
957 | } | |
958 | ||
959 | static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
960 | { | |
961 | struct xt_names_priv *priv = seq->private; | |
962 | struct net *net = seq_file_net(seq); | |
963 | u_int8_t af = priv->af; | |
964 | ||
965 | return seq_list_next(v, &net->xt.tables[af], pos); | |
966 | } | |
967 | ||
968 | static void xt_table_seq_stop(struct seq_file *seq, void *v) | |
969 | { | |
970 | struct xt_names_priv *priv = seq->private; | |
971 | u_int8_t af = priv->af; | |
972 | ||
973 | mutex_unlock(&xt[af].mutex); | |
974 | } | |
975 | ||
976 | static int xt_table_seq_show(struct seq_file *seq, void *v) | |
977 | { | |
978 | struct xt_table *table = list_entry(v, struct xt_table, list); | |
979 | ||
980 | if (strlen(table->name)) | |
981 | return seq_printf(seq, "%s\n", table->name); | |
982 | else | |
983 | return 0; | |
984 | } | |
985 | ||
986 | static const struct seq_operations xt_table_seq_ops = { | |
987 | .start = xt_table_seq_start, | |
988 | .next = xt_table_seq_next, | |
989 | .stop = xt_table_seq_stop, | |
990 | .show = xt_table_seq_show, | |
991 | }; | |
992 | ||
993 | static int xt_table_open(struct inode *inode, struct file *file) | |
994 | { | |
995 | int ret; | |
996 | struct xt_names_priv *priv; | |
997 | ||
998 | ret = seq_open_net(inode, file, &xt_table_seq_ops, | |
999 | sizeof(struct xt_names_priv)); | |
1000 | if (!ret) { | |
1001 | priv = ((struct seq_file *)file->private_data)->private; | |
1002 | priv->af = (unsigned long)PDE_DATA(inode); | |
1003 | } | |
1004 | return ret; | |
1005 | } | |
1006 | ||
1007 | static const struct file_operations xt_table_ops = { | |
1008 | .owner = THIS_MODULE, | |
1009 | .open = xt_table_open, | |
1010 | .read = seq_read, | |
1011 | .llseek = seq_lseek, | |
1012 | .release = seq_release_net, | |
1013 | }; | |
1014 | ||
1015 | /* | |
1016 | * Traverse state for ip{,6}_{tables,matches} for helping crossing | |
1017 | * the multi-AF mutexes. | |
1018 | */ | |
1019 | struct nf_mttg_trav { | |
1020 | struct list_head *head, *curr; | |
1021 | uint8_t class, nfproto; | |
1022 | }; | |
1023 | ||
1024 | enum { | |
1025 | MTTG_TRAV_INIT, | |
1026 | MTTG_TRAV_NFP_UNSPEC, | |
1027 | MTTG_TRAV_NFP_SPEC, | |
1028 | MTTG_TRAV_DONE, | |
1029 | }; | |
1030 | ||
1031 | static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos, | |
1032 | bool is_target) | |
1033 | { | |
1034 | static const uint8_t next_class[] = { | |
1035 | [MTTG_TRAV_NFP_UNSPEC] = MTTG_TRAV_NFP_SPEC, | |
1036 | [MTTG_TRAV_NFP_SPEC] = MTTG_TRAV_DONE, | |
1037 | }; | |
1038 | struct nf_mttg_trav *trav = seq->private; | |
1039 | ||
1040 | switch (trav->class) { | |
1041 | case MTTG_TRAV_INIT: | |
1042 | trav->class = MTTG_TRAV_NFP_UNSPEC; | |
1043 | mutex_lock(&xt[NFPROTO_UNSPEC].mutex); | |
1044 | trav->head = trav->curr = is_target ? | |
1045 | &xt[NFPROTO_UNSPEC].target : &xt[NFPROTO_UNSPEC].match; | |
1046 | break; | |
1047 | case MTTG_TRAV_NFP_UNSPEC: | |
1048 | trav->curr = trav->curr->next; | |
1049 | if (trav->curr != trav->head) | |
1050 | break; | |
1051 | mutex_unlock(&xt[NFPROTO_UNSPEC].mutex); | |
1052 | mutex_lock(&xt[trav->nfproto].mutex); | |
1053 | trav->head = trav->curr = is_target ? | |
1054 | &xt[trav->nfproto].target : &xt[trav->nfproto].match; | |
1055 | trav->class = next_class[trav->class]; | |
1056 | break; | |
1057 | case MTTG_TRAV_NFP_SPEC: | |
1058 | trav->curr = trav->curr->next; | |
1059 | if (trav->curr != trav->head) | |
1060 | break; | |
1061 | /* fallthru, _stop will unlock */ | |
1062 | default: | |
1063 | return NULL; | |
1064 | } | |
1065 | ||
1066 | if (ppos != NULL) | |
1067 | ++*ppos; | |
1068 | return trav; | |
1069 | } | |
1070 | ||
1071 | static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos, | |
1072 | bool is_target) | |
1073 | { | |
1074 | struct nf_mttg_trav *trav = seq->private; | |
1075 | unsigned int j; | |
1076 | ||
1077 | trav->class = MTTG_TRAV_INIT; | |
1078 | for (j = 0; j < *pos; ++j) | |
1079 | if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL) | |
1080 | return NULL; | |
1081 | return trav; | |
1082 | } | |
1083 | ||
1084 | static void xt_mttg_seq_stop(struct seq_file *seq, void *v) | |
1085 | { | |
1086 | struct nf_mttg_trav *trav = seq->private; | |
1087 | ||
1088 | switch (trav->class) { | |
1089 | case MTTG_TRAV_NFP_UNSPEC: | |
1090 | mutex_unlock(&xt[NFPROTO_UNSPEC].mutex); | |
1091 | break; | |
1092 | case MTTG_TRAV_NFP_SPEC: | |
1093 | mutex_unlock(&xt[trav->nfproto].mutex); | |
1094 | break; | |
1095 | } | |
1096 | } | |
1097 | ||
1098 | static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos) | |
1099 | { | |
1100 | return xt_mttg_seq_start(seq, pos, false); | |
1101 | } | |
1102 | ||
1103 | static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *ppos) | |
1104 | { | |
1105 | return xt_mttg_seq_next(seq, v, ppos, false); | |
1106 | } | |
1107 | ||
1108 | static int xt_match_seq_show(struct seq_file *seq, void *v) | |
1109 | { | |
1110 | const struct nf_mttg_trav *trav = seq->private; | |
1111 | const struct xt_match *match; | |
1112 | ||
1113 | switch (trav->class) { | |
1114 | case MTTG_TRAV_NFP_UNSPEC: | |
1115 | case MTTG_TRAV_NFP_SPEC: | |
1116 | if (trav->curr == trav->head) | |
1117 | return 0; | |
1118 | match = list_entry(trav->curr, struct xt_match, list); | |
1119 | return (*match->name == '\0') ? 0 : | |
1120 | seq_printf(seq, "%s\n", match->name); | |
1121 | } | |
1122 | return 0; | |
1123 | } | |
1124 | ||
1125 | static const struct seq_operations xt_match_seq_ops = { | |
1126 | .start = xt_match_seq_start, | |
1127 | .next = xt_match_seq_next, | |
1128 | .stop = xt_mttg_seq_stop, | |
1129 | .show = xt_match_seq_show, | |
1130 | }; | |
1131 | ||
1132 | static int xt_match_open(struct inode *inode, struct file *file) | |
1133 | { | |
1134 | struct seq_file *seq; | |
1135 | struct nf_mttg_trav *trav; | |
1136 | int ret; | |
1137 | ||
1138 | trav = kmalloc(sizeof(*trav), GFP_KERNEL); | |
1139 | if (trav == NULL) | |
1140 | return -ENOMEM; | |
1141 | ||
1142 | ret = seq_open(file, &xt_match_seq_ops); | |
1143 | if (ret < 0) { | |
1144 | kfree(trav); | |
1145 | return ret; | |
1146 | } | |
1147 | ||
1148 | seq = file->private_data; | |
1149 | seq->private = trav; | |
1150 | trav->nfproto = (unsigned long)PDE_DATA(inode); | |
1151 | return 0; | |
1152 | } | |
1153 | ||
1154 | static const struct file_operations xt_match_ops = { | |
1155 | .owner = THIS_MODULE, | |
1156 | .open = xt_match_open, | |
1157 | .read = seq_read, | |
1158 | .llseek = seq_lseek, | |
1159 | .release = seq_release_private, | |
1160 | }; | |
1161 | ||
1162 | static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos) | |
1163 | { | |
1164 | return xt_mttg_seq_start(seq, pos, true); | |
1165 | } | |
1166 | ||
1167 | static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *ppos) | |
1168 | { | |
1169 | return xt_mttg_seq_next(seq, v, ppos, true); | |
1170 | } | |
1171 | ||
1172 | static int xt_target_seq_show(struct seq_file *seq, void *v) | |
1173 | { | |
1174 | const struct nf_mttg_trav *trav = seq->private; | |
1175 | const struct xt_target *target; | |
1176 | ||
1177 | switch (trav->class) { | |
1178 | case MTTG_TRAV_NFP_UNSPEC: | |
1179 | case MTTG_TRAV_NFP_SPEC: | |
1180 | if (trav->curr == trav->head) | |
1181 | return 0; | |
1182 | target = list_entry(trav->curr, struct xt_target, list); | |
1183 | return (*target->name == '\0') ? 0 : | |
1184 | seq_printf(seq, "%s\n", target->name); | |
1185 | } | |
1186 | return 0; | |
1187 | } | |
1188 | ||
1189 | static const struct seq_operations xt_target_seq_ops = { | |
1190 | .start = xt_target_seq_start, | |
1191 | .next = xt_target_seq_next, | |
1192 | .stop = xt_mttg_seq_stop, | |
1193 | .show = xt_target_seq_show, | |
1194 | }; | |
1195 | ||
1196 | static int xt_target_open(struct inode *inode, struct file *file) | |
1197 | { | |
1198 | struct seq_file *seq; | |
1199 | struct nf_mttg_trav *trav; | |
1200 | int ret; | |
1201 | ||
1202 | trav = kmalloc(sizeof(*trav), GFP_KERNEL); | |
1203 | if (trav == NULL) | |
1204 | return -ENOMEM; | |
1205 | ||
1206 | ret = seq_open(file, &xt_target_seq_ops); | |
1207 | if (ret < 0) { | |
1208 | kfree(trav); | |
1209 | return ret; | |
1210 | } | |
1211 | ||
1212 | seq = file->private_data; | |
1213 | seq->private = trav; | |
1214 | trav->nfproto = (unsigned long)PDE_DATA(inode); | |
1215 | return 0; | |
1216 | } | |
1217 | ||
1218 | static const struct file_operations xt_target_ops = { | |
1219 | .owner = THIS_MODULE, | |
1220 | .open = xt_target_open, | |
1221 | .read = seq_read, | |
1222 | .llseek = seq_lseek, | |
1223 | .release = seq_release_private, | |
1224 | }; | |
1225 | ||
1226 | #define FORMAT_TABLES "_tables_names" | |
1227 | #define FORMAT_MATCHES "_tables_matches" | |
1228 | #define FORMAT_TARGETS "_tables_targets" | |
1229 | ||
1230 | #endif /* CONFIG_PROC_FS */ | |
1231 | ||
1232 | /** | |
1233 | * xt_hook_link - set up hooks for a new table | |
1234 | * @table: table with metadata needed to set up hooks | |
1235 | * @fn: Hook function | |
1236 | * | |
1237 | * This function will take care of creating and registering the necessary | |
1238 | * Netfilter hooks for XT tables. | |
1239 | */ | |
1240 | struct nf_hook_ops *xt_hook_link(const struct xt_table *table, nf_hookfn *fn) | |
1241 | { | |
1242 | unsigned int hook_mask = table->valid_hooks; | |
1243 | uint8_t i, num_hooks = hweight32(hook_mask); | |
1244 | uint8_t hooknum; | |
1245 | struct nf_hook_ops *ops; | |
1246 | int ret; | |
1247 | ||
1248 | ops = kmalloc(sizeof(*ops) * num_hooks, GFP_KERNEL); | |
1249 | if (ops == NULL) | |
1250 | return ERR_PTR(-ENOMEM); | |
1251 | ||
1252 | for (i = 0, hooknum = 0; i < num_hooks && hook_mask != 0; | |
1253 | hook_mask >>= 1, ++hooknum) { | |
1254 | if (!(hook_mask & 1)) | |
1255 | continue; | |
1256 | ops[i].hook = fn; | |
1257 | ops[i].owner = table->me; | |
1258 | ops[i].pf = table->af; | |
1259 | ops[i].hooknum = hooknum; | |
1260 | ops[i].priority = table->priority; | |
1261 | ++i; | |
1262 | } | |
1263 | ||
1264 | ret = nf_register_hooks(ops, num_hooks); | |
1265 | if (ret < 0) { | |
1266 | kfree(ops); | |
1267 | return ERR_PTR(ret); | |
1268 | } | |
1269 | ||
1270 | return ops; | |
1271 | } | |
1272 | EXPORT_SYMBOL_GPL(xt_hook_link); | |
1273 | ||
1274 | /** | |
1275 | * xt_hook_unlink - remove hooks for a table | |
1276 | * @ops: nf_hook_ops array as returned by nf_hook_link | |
1277 | * @hook_mask: the very same mask that was passed to nf_hook_link | |
1278 | */ | |
1279 | void xt_hook_unlink(const struct xt_table *table, struct nf_hook_ops *ops) | |
1280 | { | |
1281 | nf_unregister_hooks(ops, hweight32(table->valid_hooks)); | |
1282 | kfree(ops); | |
1283 | } | |
1284 | EXPORT_SYMBOL_GPL(xt_hook_unlink); | |
1285 | ||
1286 | int xt_proto_init(struct net *net, u_int8_t af) | |
1287 | { | |
1288 | #ifdef CONFIG_PROC_FS | |
1289 | char buf[XT_FUNCTION_MAXNAMELEN]; | |
1290 | struct proc_dir_entry *proc; | |
1291 | #endif | |
1292 | ||
1293 | if (af >= ARRAY_SIZE(xt_prefix)) | |
1294 | return -EINVAL; | |
1295 | ||
1296 | ||
1297 | #ifdef CONFIG_PROC_FS | |
1298 | strlcpy(buf, xt_prefix[af], sizeof(buf)); | |
1299 | strlcat(buf, FORMAT_TABLES, sizeof(buf)); | |
1300 | proc = proc_create_data(buf, 0440, net->proc_net, &xt_table_ops, | |
1301 | (void *)(unsigned long)af); | |
1302 | if (!proc) | |
1303 | goto out; | |
1304 | ||
1305 | strlcpy(buf, xt_prefix[af], sizeof(buf)); | |
1306 | strlcat(buf, FORMAT_MATCHES, sizeof(buf)); | |
1307 | proc = proc_create_data(buf, 0440, net->proc_net, &xt_match_ops, | |
1308 | (void *)(unsigned long)af); | |
1309 | if (!proc) | |
1310 | goto out_remove_tables; | |
1311 | ||
1312 | strlcpy(buf, xt_prefix[af], sizeof(buf)); | |
1313 | strlcat(buf, FORMAT_TARGETS, sizeof(buf)); | |
1314 | proc = proc_create_data(buf, 0440, net->proc_net, &xt_target_ops, | |
1315 | (void *)(unsigned long)af); | |
1316 | if (!proc) | |
1317 | goto out_remove_matches; | |
1318 | #endif | |
1319 | ||
1320 | return 0; | |
1321 | ||
1322 | #ifdef CONFIG_PROC_FS | |
1323 | out_remove_matches: | |
1324 | strlcpy(buf, xt_prefix[af], sizeof(buf)); | |
1325 | strlcat(buf, FORMAT_MATCHES, sizeof(buf)); | |
1326 | remove_proc_entry(buf, net->proc_net); | |
1327 | ||
1328 | out_remove_tables: | |
1329 | strlcpy(buf, xt_prefix[af], sizeof(buf)); | |
1330 | strlcat(buf, FORMAT_TABLES, sizeof(buf)); | |
1331 | remove_proc_entry(buf, net->proc_net); | |
1332 | out: | |
1333 | return -1; | |
1334 | #endif | |
1335 | } | |
1336 | EXPORT_SYMBOL_GPL(xt_proto_init); | |
1337 | ||
1338 | void xt_proto_fini(struct net *net, u_int8_t af) | |
1339 | { | |
1340 | #ifdef CONFIG_PROC_FS | |
1341 | char buf[XT_FUNCTION_MAXNAMELEN]; | |
1342 | ||
1343 | strlcpy(buf, xt_prefix[af], sizeof(buf)); | |
1344 | strlcat(buf, FORMAT_TABLES, sizeof(buf)); | |
1345 | remove_proc_entry(buf, net->proc_net); | |
1346 | ||
1347 | strlcpy(buf, xt_prefix[af], sizeof(buf)); | |
1348 | strlcat(buf, FORMAT_TARGETS, sizeof(buf)); | |
1349 | remove_proc_entry(buf, net->proc_net); | |
1350 | ||
1351 | strlcpy(buf, xt_prefix[af], sizeof(buf)); | |
1352 | strlcat(buf, FORMAT_MATCHES, sizeof(buf)); | |
1353 | remove_proc_entry(buf, net->proc_net); | |
1354 | #endif /*CONFIG_PROC_FS*/ | |
1355 | } | |
1356 | EXPORT_SYMBOL_GPL(xt_proto_fini); | |
1357 | ||
1358 | static int __net_init xt_net_init(struct net *net) | |
1359 | { | |
1360 | int i; | |
1361 | ||
1362 | for (i = 0; i < NFPROTO_NUMPROTO; i++) | |
1363 | INIT_LIST_HEAD(&net->xt.tables[i]); | |
1364 | return 0; | |
1365 | } | |
1366 | ||
1367 | static struct pernet_operations xt_net_ops = { | |
1368 | .init = xt_net_init, | |
1369 | }; | |
1370 | ||
1371 | static int __init xt_init(void) | |
1372 | { | |
1373 | unsigned int i; | |
1374 | int rv; | |
1375 | ||
1376 | for_each_possible_cpu(i) { | |
1377 | seqcount_init(&per_cpu(xt_recseq, i)); | |
1378 | } | |
1379 | ||
1380 | xt = kmalloc(sizeof(struct xt_af) * NFPROTO_NUMPROTO, GFP_KERNEL); | |
1381 | if (!xt) | |
1382 | return -ENOMEM; | |
1383 | ||
1384 | for (i = 0; i < NFPROTO_NUMPROTO; i++) { | |
1385 | mutex_init(&xt[i].mutex); | |
1386 | #ifdef CONFIG_COMPAT | |
1387 | mutex_init(&xt[i].compat_mutex); | |
1388 | xt[i].compat_tab = NULL; | |
1389 | #endif | |
1390 | INIT_LIST_HEAD(&xt[i].target); | |
1391 | INIT_LIST_HEAD(&xt[i].match); | |
1392 | } | |
1393 | rv = register_pernet_subsys(&xt_net_ops); | |
1394 | if (rv < 0) | |
1395 | kfree(xt); | |
1396 | return rv; | |
1397 | } | |
1398 | ||
1399 | static void __exit xt_fini(void) | |
1400 | { | |
1401 | unregister_pernet_subsys(&xt_net_ops); | |
1402 | kfree(xt); | |
1403 | } | |
1404 | ||
1405 | module_init(xt_init); | |
1406 | module_exit(xt_fini); | |
1407 |