1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * x_tables core - Backend for {ip,ip6,arp}_tables |
4 | * |
5 | * Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org> |
6 | * Copyright (C) 2006-2012 Patrick McHardy <kaber@trash.net> |
7 | * |
8 | * Based on existing ip_tables code which is |
9 | * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling |
10 | * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org> |
11 | */ |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | #include <linux/kernel.h> |
14 | #include <linux/module.h> |
15 | #include <linux/socket.h> |
16 | #include <linux/net.h> |
17 | #include <linux/proc_fs.h> |
18 | #include <linux/seq_file.h> |
19 | #include <linux/string.h> |
20 | #include <linux/vmalloc.h> |
21 | #include <linux/mutex.h> |
22 | #include <linux/mm.h> |
23 | #include <linux/slab.h> |
24 | #include <linux/audit.h> |
25 | #include <linux/user_namespace.h> |
26 | #include <net/net_namespace.h> |
27 | #include <net/netns/generic.h> |
28 | |
29 | #include <linux/netfilter/x_tables.h> |
30 | #include <linux/netfilter_arp.h> |
31 | #include <linux/netfilter_ipv4/ip_tables.h> |
32 | #include <linux/netfilter_ipv6/ip6_tables.h> |
33 | #include <linux/netfilter_arp/arp_tables.h> |
34 | |
35 | MODULE_LICENSE("GPL" ); |
36 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>" ); |
37 | MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module" ); |
38 | |
39 | #define XT_PCPU_BLOCK_SIZE 4096 |
40 | #define XT_MAX_TABLE_SIZE (512 * 1024 * 1024) |
41 | |
42 | struct xt_template { |
43 | struct list_head list; |
44 | |
45 | /* called when table is needed in the given netns */ |
46 | int (*table_init)(struct net *net); |
47 | |
48 | struct module *me; |
49 | |
50 | /* A unique name... */ |
51 | char name[XT_TABLE_MAXNAMELEN]; |
52 | }; |
53 | |
54 | static struct list_head xt_templates[NFPROTO_NUMPROTO]; |
55 | |
56 | struct xt_pernet { |
57 | struct list_head tables[NFPROTO_NUMPROTO]; |
58 | }; |
59 | |
60 | struct compat_delta { |
61 | unsigned int offset; /* offset in kernel */ |
62 | int delta; /* delta in 32bit user land */ |
63 | }; |
64 | |
65 | struct xt_af { |
66 | struct mutex mutex; |
67 | struct list_head match; |
68 | struct list_head target; |
69 | #ifdef CONFIG_NETFILTER_XTABLES_COMPAT |
70 | struct mutex compat_mutex; |
71 | struct compat_delta *compat_tab; |
72 | unsigned int number; /* number of slots in compat_tab[] */ |
73 | unsigned int cur; /* number of used slots in compat_tab[] */ |
74 | #endif |
75 | }; |
76 | |
77 | static unsigned int xt_pernet_id __read_mostly; |
78 | static struct xt_af *xt __read_mostly; |
79 | |
80 | static const char *const xt_prefix[NFPROTO_NUMPROTO] = { |
81 | [NFPROTO_UNSPEC] = "x" , |
82 | [NFPROTO_IPV4] = "ip" , |
83 | [NFPROTO_ARP] = "arp" , |
84 | [NFPROTO_BRIDGE] = "eb" , |
85 | [NFPROTO_IPV6] = "ip6" , |
86 | }; |
87 | |
88 | /* Registration hooks for targets. */ |
89 | int xt_register_target(struct xt_target *target) |
90 | { |
91 | u_int8_t af = target->family; |
92 | |
93 | mutex_lock(&xt[af].mutex); |
94 | list_add(new: &target->list, head: &xt[af].target); |
95 | mutex_unlock(lock: &xt[af].mutex); |
96 | return 0; |
97 | } |
98 | EXPORT_SYMBOL(xt_register_target); |
99 | |
100 | void |
101 | xt_unregister_target(struct xt_target *target) |
102 | { |
103 | u_int8_t af = target->family; |
104 | |
105 | mutex_lock(&xt[af].mutex); |
106 | list_del(entry: &target->list); |
107 | mutex_unlock(lock: &xt[af].mutex); |
108 | } |
109 | EXPORT_SYMBOL(xt_unregister_target); |
110 | |
111 | int |
112 | xt_register_targets(struct xt_target *target, unsigned int n) |
113 | { |
114 | unsigned int i; |
115 | int err = 0; |
116 | |
117 | for (i = 0; i < n; i++) { |
118 | err = xt_register_target(&target[i]); |
119 | if (err) |
120 | goto err; |
121 | } |
122 | return err; |
123 | |
124 | err: |
125 | if (i > 0) |
126 | xt_unregister_targets(target, n: i); |
127 | return err; |
128 | } |
129 | EXPORT_SYMBOL(xt_register_targets); |
130 | |
131 | void |
132 | xt_unregister_targets(struct xt_target *target, unsigned int n) |
133 | { |
134 | while (n-- > 0) |
135 | xt_unregister_target(&target[n]); |
136 | } |
137 | EXPORT_SYMBOL(xt_unregister_targets); |
138 | |
139 | int xt_register_match(struct xt_match *match) |
140 | { |
141 | u_int8_t af = match->family; |
142 | |
143 | mutex_lock(&xt[af].mutex); |
144 | list_add(new: &match->list, head: &xt[af].match); |
145 | mutex_unlock(lock: &xt[af].mutex); |
146 | return 0; |
147 | } |
148 | EXPORT_SYMBOL(xt_register_match); |
149 | |
150 | void |
151 | xt_unregister_match(struct xt_match *match) |
152 | { |
153 | u_int8_t af = match->family; |
154 | |
155 | mutex_lock(&xt[af].mutex); |
156 | list_del(entry: &match->list); |
157 | mutex_unlock(lock: &xt[af].mutex); |
158 | } |
159 | EXPORT_SYMBOL(xt_unregister_match); |
160 | |
161 | int |
162 | xt_register_matches(struct xt_match *match, unsigned int n) |
163 | { |
164 | unsigned int i; |
165 | int err = 0; |
166 | |
167 | for (i = 0; i < n; i++) { |
168 | err = xt_register_match(&match[i]); |
169 | if (err) |
170 | goto err; |
171 | } |
172 | return err; |
173 | |
174 | err: |
175 | if (i > 0) |
176 | xt_unregister_matches(match, n: i); |
177 | return err; |
178 | } |
179 | EXPORT_SYMBOL(xt_register_matches); |
180 | |
181 | void |
182 | xt_unregister_matches(struct xt_match *match, unsigned int n) |
183 | { |
184 | while (n-- > 0) |
185 | xt_unregister_match(&match[n]); |
186 | } |
187 | EXPORT_SYMBOL(xt_unregister_matches); |
188 | |
189 | |
190 | /* |
191 | * These are weird, but module loading must not be done with mutex |
192 | * held (since they will register), and we have to have a single |
193 | * function to use. |
194 | */ |
195 | |
196 | /* Find match, grabs ref. Returns ERR_PTR() on error. */ |
197 | struct xt_match *xt_find_match(u8 af, const char *name, u8 revision) |
198 | { |
199 | struct xt_match *m; |
200 | int err = -ENOENT; |
201 | |
202 | if (strnlen(p: name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN) |
203 | return ERR_PTR(error: -EINVAL); |
204 | |
205 | mutex_lock(&xt[af].mutex); |
206 | list_for_each_entry(m, &xt[af].match, list) { |
207 | if (strcmp(m->name, name) == 0) { |
208 | if (m->revision == revision) { |
209 | if (try_module_get(module: m->me)) { |
210 | mutex_unlock(lock: &xt[af].mutex); |
211 | return m; |
212 | } |
213 | } else |
214 | err = -EPROTOTYPE; /* Found something. */ |
215 | } |
216 | } |
217 | mutex_unlock(lock: &xt[af].mutex); |
218 | |
219 | if (af != NFPROTO_UNSPEC) |
220 | /* Try searching again in the family-independent list */ |
221 | return xt_find_match(af: NFPROTO_UNSPEC, name, revision); |
222 | |
223 | return ERR_PTR(error: err); |
224 | } |
225 | EXPORT_SYMBOL(xt_find_match); |
226 | |
227 | struct xt_match * |
228 | xt_request_find_match(uint8_t nfproto, const char *name, uint8_t revision) |
229 | { |
230 | struct xt_match *match; |
231 | |
232 | if (strnlen(p: name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN) |
233 | return ERR_PTR(error: -EINVAL); |
234 | |
235 | match = xt_find_match(nfproto, name, revision); |
236 | if (IS_ERR(ptr: match)) { |
237 | request_module("%st_%s" , xt_prefix[nfproto], name); |
238 | match = xt_find_match(nfproto, name, revision); |
239 | } |
240 | |
241 | return match; |
242 | } |
243 | EXPORT_SYMBOL_GPL(xt_request_find_match); |
244 | |
245 | /* Find target, grabs ref. Returns ERR_PTR() on error. */ |
246 | static struct xt_target *xt_find_target(u8 af, const char *name, u8 revision) |
247 | { |
248 | struct xt_target *t; |
249 | int err = -ENOENT; |
250 | |
251 | if (strnlen(p: name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN) |
252 | return ERR_PTR(error: -EINVAL); |
253 | |
254 | mutex_lock(&xt[af].mutex); |
255 | list_for_each_entry(t, &xt[af].target, list) { |
256 | if (strcmp(t->name, name) == 0) { |
257 | if (t->revision == revision) { |
258 | if (try_module_get(module: t->me)) { |
259 | mutex_unlock(lock: &xt[af].mutex); |
260 | return t; |
261 | } |
262 | } else |
263 | err = -EPROTOTYPE; /* Found something. */ |
264 | } |
265 | } |
266 | mutex_unlock(lock: &xt[af].mutex); |
267 | |
268 | if (af != NFPROTO_UNSPEC) |
269 | /* Try searching again in the family-independent list */ |
270 | return xt_find_target(af: NFPROTO_UNSPEC, name, revision); |
271 | |
272 | return ERR_PTR(error: err); |
273 | } |
274 | |
275 | struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision) |
276 | { |
277 | struct xt_target *target; |
278 | |
279 | if (strnlen(p: name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN) |
280 | return ERR_PTR(error: -EINVAL); |
281 | |
282 | target = xt_find_target(af, name, revision); |
283 | if (IS_ERR(ptr: target)) { |
284 | request_module("%st_%s" , xt_prefix[af], name); |
285 | target = xt_find_target(af, name, revision); |
286 | } |
287 | |
288 | return target; |
289 | } |
290 | EXPORT_SYMBOL_GPL(xt_request_find_target); |
291 | |
292 | |
293 | static int xt_obj_to_user(u16 __user *psize, u16 size, |
294 | void __user *pname, const char *name, |
295 | u8 __user *prev, u8 rev) |
296 | { |
297 | if (put_user(size, psize)) |
298 | return -EFAULT; |
299 | if (copy_to_user(to: pname, from: name, strlen(name) + 1)) |
300 | return -EFAULT; |
301 | if (put_user(rev, prev)) |
302 | return -EFAULT; |
303 | |
304 | return 0; |
305 | } |
306 | |
307 | #define XT_OBJ_TO_USER(U, K, TYPE, C_SIZE) \ |
308 | xt_obj_to_user(&U->u.TYPE##_size, C_SIZE ? : K->u.TYPE##_size, \ |
309 | U->u.user.name, K->u.kernel.TYPE->name, \ |
310 | &U->u.user.revision, K->u.kernel.TYPE->revision) |
311 | |
312 | int xt_data_to_user(void __user *dst, const void *src, |
313 | int usersize, int size, int aligned_size) |
314 | { |
315 | usersize = usersize ? : size; |
316 | if (copy_to_user(to: dst, from: src, n: usersize)) |
317 | return -EFAULT; |
318 | if (usersize != aligned_size && |
319 | clear_user(to: dst + usersize, n: aligned_size - usersize)) |
320 | return -EFAULT; |
321 | |
322 | return 0; |
323 | } |
324 | EXPORT_SYMBOL_GPL(xt_data_to_user); |
325 | |
326 | #define XT_DATA_TO_USER(U, K, TYPE) \ |
327 | xt_data_to_user(U->data, K->data, \ |
328 | K->u.kernel.TYPE->usersize, \ |
329 | K->u.kernel.TYPE->TYPE##size, \ |
330 | XT_ALIGN(K->u.kernel.TYPE->TYPE##size)) |
331 | |
332 | int xt_match_to_user(const struct xt_entry_match *m, |
333 | struct xt_entry_match __user *u) |
334 | { |
335 | return XT_OBJ_TO_USER(u, m, match, 0) || |
336 | XT_DATA_TO_USER(u, m, match); |
337 | } |
338 | EXPORT_SYMBOL_GPL(xt_match_to_user); |
339 | |
340 | int xt_target_to_user(const struct xt_entry_target *t, |
341 | struct xt_entry_target __user *u) |
342 | { |
343 | return XT_OBJ_TO_USER(u, t, target, 0) || |
344 | XT_DATA_TO_USER(u, t, target); |
345 | } |
346 | EXPORT_SYMBOL_GPL(xt_target_to_user); |
347 | |
348 | static int match_revfn(u8 af, const char *name, u8 revision, int *bestp) |
349 | { |
350 | const struct xt_match *m; |
351 | int have_rev = 0; |
352 | |
353 | mutex_lock(&xt[af].mutex); |
354 | list_for_each_entry(m, &xt[af].match, list) { |
355 | if (strcmp(m->name, name) == 0) { |
356 | if (m->revision > *bestp) |
357 | *bestp = m->revision; |
358 | if (m->revision == revision) |
359 | have_rev = 1; |
360 | } |
361 | } |
362 | mutex_unlock(lock: &xt[af].mutex); |
363 | |
364 | if (af != NFPROTO_UNSPEC && !have_rev) |
365 | return match_revfn(af: NFPROTO_UNSPEC, name, revision, bestp); |
366 | |
367 | return have_rev; |
368 | } |
369 | |
370 | static int target_revfn(u8 af, const char *name, u8 revision, int *bestp) |
371 | { |
372 | const struct xt_target *t; |
373 | int have_rev = 0; |
374 | |
375 | mutex_lock(&xt[af].mutex); |
376 | list_for_each_entry(t, &xt[af].target, list) { |
377 | if (strcmp(t->name, name) == 0) { |
378 | if (t->revision > *bestp) |
379 | *bestp = t->revision; |
380 | if (t->revision == revision) |
381 | have_rev = 1; |
382 | } |
383 | } |
384 | mutex_unlock(lock: &xt[af].mutex); |
385 | |
386 | if (af != NFPROTO_UNSPEC && !have_rev) |
387 | return target_revfn(af: NFPROTO_UNSPEC, name, revision, bestp); |
388 | |
389 | return have_rev; |
390 | } |
391 | |
392 | /* Returns true or false (if no such extension at all) */ |
393 | int xt_find_revision(u8 af, const char *name, u8 revision, int target, |
394 | int *err) |
395 | { |
396 | int have_rev, best = -1; |
397 | |
398 | if (target == 1) |
399 | have_rev = target_revfn(af, name, revision, bestp: &best); |
400 | else |
401 | have_rev = match_revfn(af, name, revision, bestp: &best); |
402 | |
403 | /* Nothing at all? Return 0 to try loading module. */ |
404 | if (best == -1) { |
405 | *err = -ENOENT; |
406 | return 0; |
407 | } |
408 | |
409 | *err = best; |
410 | if (!have_rev) |
411 | *err = -EPROTONOSUPPORT; |
412 | return 1; |
413 | } |
414 | EXPORT_SYMBOL_GPL(xt_find_revision); |
415 | |
416 | static char * |
417 | textify_hooks(char *buf, size_t size, unsigned int mask, uint8_t nfproto) |
418 | { |
419 | static const char *const inetbr_names[] = { |
420 | "PREROUTING" , "INPUT" , "FORWARD" , |
421 | "OUTPUT" , "POSTROUTING" , "BROUTING" , |
422 | }; |
423 | static const char *const arp_names[] = { |
424 | "INPUT" , "FORWARD" , "OUTPUT" , |
425 | }; |
426 | const char *const *names; |
427 | unsigned int i, max; |
428 | char *p = buf; |
429 | bool np = false; |
430 | int res; |
431 | |
432 | names = (nfproto == NFPROTO_ARP) ? arp_names : inetbr_names; |
433 | max = (nfproto == NFPROTO_ARP) ? ARRAY_SIZE(arp_names) : |
434 | ARRAY_SIZE(inetbr_names); |
435 | *p = '\0'; |
436 | for (i = 0; i < max; ++i) { |
437 | if (!(mask & (1 << i))) |
438 | continue; |
439 | res = snprintf(buf: p, size, fmt: "%s%s" , np ? "/" : "" , names[i]); |
440 | if (res > 0) { |
441 | size -= res; |
442 | p += res; |
443 | } |
444 | np = true; |
445 | } |
446 | |
447 | return buf; |
448 | } |
449 | |
450 | /** |
451 | * xt_check_proc_name - check that name is suitable for /proc file creation |
452 | * |
453 | * @name: file name candidate |
454 | * @size: length of buffer |
455 | * |
456 | * some x_tables modules wish to create a file in /proc. |
457 | * This function makes sure that the name is suitable for this |
458 | * purpose, it checks that name is NUL terminated and isn't a 'special' |
459 | * name, like "..". |
460 | * |
461 | * returns negative number on error or 0 if name is useable. |
462 | */ |
463 | int xt_check_proc_name(const char *name, unsigned int size) |
464 | { |
465 | if (name[0] == '\0') |
466 | return -EINVAL; |
467 | |
468 | if (strnlen(p: name, maxlen: size) == size) |
469 | return -ENAMETOOLONG; |
470 | |
471 | if (strcmp(name, "." ) == 0 || |
472 | strcmp(name, ".." ) == 0 || |
473 | strchr(name, '/')) |
474 | return -EINVAL; |
475 | |
476 | return 0; |
477 | } |
478 | EXPORT_SYMBOL(xt_check_proc_name); |
479 | |
480 | int xt_check_match(struct xt_mtchk_param *par, |
481 | unsigned int size, u16 proto, bool inv_proto) |
482 | { |
483 | int ret; |
484 | |
485 | if (XT_ALIGN(par->match->matchsize) != size && |
486 | par->match->matchsize != -1) { |
487 | /* |
488 | * ebt_among is exempt from centralized matchsize checking |
489 | * because it uses a dynamic-size data set. |
490 | */ |
491 | pr_err_ratelimited("%s_tables: %s.%u match: invalid size %u (kernel) != (user) %u\n" , |
492 | xt_prefix[par->family], par->match->name, |
493 | par->match->revision, |
494 | XT_ALIGN(par->match->matchsize), size); |
495 | return -EINVAL; |
496 | } |
497 | if (par->match->table != NULL && |
498 | strcmp(par->match->table, par->table) != 0) { |
499 | pr_info_ratelimited("%s_tables: %s match: only valid in %s table, not %s\n" , |
500 | xt_prefix[par->family], par->match->name, |
501 | par->match->table, par->table); |
502 | return -EINVAL; |
503 | } |
504 | if (par->match->hooks && (par->hook_mask & ~par->match->hooks) != 0) { |
505 | char used[64], allow[64]; |
506 | |
507 | pr_info_ratelimited("%s_tables: %s match: used from hooks %s, but only valid from %s\n" , |
508 | xt_prefix[par->family], par->match->name, |
509 | textify_hooks(used, sizeof(used), |
510 | par->hook_mask, par->family), |
511 | textify_hooks(allow, sizeof(allow), |
512 | par->match->hooks, |
513 | par->family)); |
514 | return -EINVAL; |
515 | } |
516 | if (par->match->proto && (par->match->proto != proto || inv_proto)) { |
517 | pr_info_ratelimited("%s_tables: %s match: only valid for protocol %u\n" , |
518 | xt_prefix[par->family], par->match->name, |
519 | par->match->proto); |
520 | return -EINVAL; |
521 | } |
522 | if (par->match->checkentry != NULL) { |
523 | ret = par->match->checkentry(par); |
524 | if (ret < 0) |
525 | return ret; |
526 | else if (ret > 0) |
527 | /* Flag up potential errors. */ |
528 | return -EIO; |
529 | } |
530 | return 0; |
531 | } |
532 | EXPORT_SYMBOL_GPL(xt_check_match); |
533 | |
534 | /** xt_check_entry_match - check that matches end before start of target |
535 | * |
536 | * @match: beginning of xt_entry_match |
537 | * @target: beginning of this rules target (alleged end of matches) |
538 | * @alignment: alignment requirement of match structures |
539 | * |
540 | * Validates that all matches add up to the beginning of the target, |
541 | * and that each match covers at least the base structure size. |
542 | * |
543 | * Return: 0 on success, negative errno on failure. |
544 | */ |
545 | static int xt_check_entry_match(const char *match, const char *target, |
546 | const size_t alignment) |
547 | { |
548 | const struct xt_entry_match *pos; |
549 | int length = target - match; |
550 | |
551 | if (length == 0) /* no matches */ |
552 | return 0; |
553 | |
554 | pos = (struct xt_entry_match *)match; |
555 | do { |
556 | if ((unsigned long)pos % alignment) |
557 | return -EINVAL; |
558 | |
559 | if (length < (int)sizeof(struct xt_entry_match)) |
560 | return -EINVAL; |
561 | |
562 | if (pos->u.match_size < sizeof(struct xt_entry_match)) |
563 | return -EINVAL; |
564 | |
565 | if (pos->u.match_size > length) |
566 | return -EINVAL; |
567 | |
568 | length -= pos->u.match_size; |
569 | pos = ((void *)((char *)(pos) + (pos)->u.match_size)); |
570 | } while (length > 0); |
571 | |
572 | return 0; |
573 | } |
574 | |
575 | /** xt_check_table_hooks - check hook entry points are sane |
576 | * |
577 | * @info xt_table_info to check |
578 | * @valid_hooks - hook entry points that we can enter from |
579 | * |
580 | * Validates that the hook entry and underflows points are set up. |
581 | * |
582 | * Return: 0 on success, negative errno on failure. |
583 | */ |
584 | int xt_check_table_hooks(const struct xt_table_info *info, unsigned int valid_hooks) |
585 | { |
586 | const char *err = "unsorted underflow" ; |
587 | unsigned int i, max_uflow, max_entry; |
588 | bool check_hooks = false; |
589 | |
590 | BUILD_BUG_ON(ARRAY_SIZE(info->hook_entry) != ARRAY_SIZE(info->underflow)); |
591 | |
592 | max_entry = 0; |
593 | max_uflow = 0; |
594 | |
595 | for (i = 0; i < ARRAY_SIZE(info->hook_entry); i++) { |
596 | if (!(valid_hooks & (1 << i))) |
597 | continue; |
598 | |
599 | if (info->hook_entry[i] == 0xFFFFFFFF) |
600 | return -EINVAL; |
601 | if (info->underflow[i] == 0xFFFFFFFF) |
602 | return -EINVAL; |
603 | |
604 | if (check_hooks) { |
605 | if (max_uflow > info->underflow[i]) |
606 | goto error; |
607 | |
608 | if (max_uflow == info->underflow[i]) { |
609 | err = "duplicate underflow" ; |
610 | goto error; |
611 | } |
612 | if (max_entry > info->hook_entry[i]) { |
613 | err = "unsorted entry" ; |
614 | goto error; |
615 | } |
616 | if (max_entry == info->hook_entry[i]) { |
617 | err = "duplicate entry" ; |
618 | goto error; |
619 | } |
620 | } |
621 | max_entry = info->hook_entry[i]; |
622 | max_uflow = info->underflow[i]; |
623 | check_hooks = true; |
624 | } |
625 | |
626 | return 0; |
627 | error: |
628 | pr_err_ratelimited("%s at hook %d\n" , err, i); |
629 | return -EINVAL; |
630 | } |
631 | EXPORT_SYMBOL(xt_check_table_hooks); |
632 | |
633 | static bool verdict_ok(int verdict) |
634 | { |
635 | if (verdict > 0) |
636 | return true; |
637 | |
638 | if (verdict < 0) { |
639 | int v = -verdict - 1; |
640 | |
641 | if (verdict == XT_RETURN) |
642 | return true; |
643 | |
644 | switch (v) { |
645 | case NF_ACCEPT: return true; |
646 | case NF_DROP: return true; |
647 | case NF_QUEUE: return true; |
648 | default: |
649 | break; |
650 | } |
651 | |
652 | return false; |
653 | } |
654 | |
655 | return false; |
656 | } |
657 | |
658 | static bool error_tg_ok(unsigned int usersize, unsigned int kernsize, |
659 | const char *msg, unsigned int msglen) |
660 | { |
661 | return usersize == kernsize && strnlen(p: msg, maxlen: msglen) < msglen; |
662 | } |
663 | |
664 | #ifdef CONFIG_NETFILTER_XTABLES_COMPAT |
665 | int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta) |
666 | { |
667 | struct xt_af *xp = &xt[af]; |
668 | |
669 | WARN_ON(!mutex_is_locked(&xt[af].compat_mutex)); |
670 | |
671 | if (WARN_ON(!xp->compat_tab)) |
672 | return -ENOMEM; |
673 | |
674 | if (xp->cur >= xp->number) |
675 | return -EINVAL; |
676 | |
677 | if (xp->cur) |
678 | delta += xp->compat_tab[xp->cur - 1].delta; |
679 | xp->compat_tab[xp->cur].offset = offset; |
680 | xp->compat_tab[xp->cur].delta = delta; |
681 | xp->cur++; |
682 | return 0; |
683 | } |
684 | EXPORT_SYMBOL_GPL(xt_compat_add_offset); |
685 | |
686 | void xt_compat_flush_offsets(u_int8_t af) |
687 | { |
688 | WARN_ON(!mutex_is_locked(&xt[af].compat_mutex)); |
689 | |
690 | if (xt[af].compat_tab) { |
691 | vfree(addr: xt[af].compat_tab); |
692 | xt[af].compat_tab = NULL; |
693 | xt[af].number = 0; |
694 | xt[af].cur = 0; |
695 | } |
696 | } |
697 | EXPORT_SYMBOL_GPL(xt_compat_flush_offsets); |
698 | |
699 | int xt_compat_calc_jump(u_int8_t af, unsigned int offset) |
700 | { |
701 | struct compat_delta *tmp = xt[af].compat_tab; |
702 | int mid, left = 0, right = xt[af].cur - 1; |
703 | |
704 | while (left <= right) { |
705 | mid = (left + right) >> 1; |
706 | if (offset > tmp[mid].offset) |
707 | left = mid + 1; |
708 | else if (offset < tmp[mid].offset) |
709 | right = mid - 1; |
710 | else |
711 | return mid ? tmp[mid - 1].delta : 0; |
712 | } |
713 | return left ? tmp[left - 1].delta : 0; |
714 | } |
715 | EXPORT_SYMBOL_GPL(xt_compat_calc_jump); |
716 | |
717 | int xt_compat_init_offsets(u8 af, unsigned int number) |
718 | { |
719 | size_t mem; |
720 | |
721 | WARN_ON(!mutex_is_locked(&xt[af].compat_mutex)); |
722 | |
723 | if (!number || number > (INT_MAX / sizeof(struct compat_delta))) |
724 | return -EINVAL; |
725 | |
726 | if (WARN_ON(xt[af].compat_tab)) |
727 | return -EINVAL; |
728 | |
729 | mem = sizeof(struct compat_delta) * number; |
730 | if (mem > XT_MAX_TABLE_SIZE) |
731 | return -ENOMEM; |
732 | |
733 | xt[af].compat_tab = vmalloc(size: mem); |
734 | if (!xt[af].compat_tab) |
735 | return -ENOMEM; |
736 | |
737 | xt[af].number = number; |
738 | xt[af].cur = 0; |
739 | |
740 | return 0; |
741 | } |
742 | EXPORT_SYMBOL(xt_compat_init_offsets); |
743 | |
744 | int xt_compat_match_offset(const struct xt_match *match) |
745 | { |
746 | u_int16_t csize = match->compatsize ? : match->matchsize; |
747 | return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize); |
748 | } |
749 | EXPORT_SYMBOL_GPL(xt_compat_match_offset); |
750 | |
751 | void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr, |
752 | unsigned int *size) |
753 | { |
754 | const struct xt_match *match = m->u.kernel.match; |
755 | struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m; |
756 | int off = xt_compat_match_offset(match); |
757 | u_int16_t msize = cm->u.user.match_size; |
758 | char name[sizeof(m->u.user.name)]; |
759 | |
760 | m = *dstptr; |
761 | memcpy(m, cm, sizeof(*cm)); |
762 | if (match->compat_from_user) |
763 | match->compat_from_user(m->data, cm->data); |
764 | else |
765 | memcpy(m->data, cm->data, msize - sizeof(*cm)); |
766 | |
767 | msize += off; |
768 | m->u.user.match_size = msize; |
769 | strscpy(p: name, q: match->name, size: sizeof(name)); |
770 | module_put(module: match->me); |
771 | strscpy_pad(dest: m->u.user.name, src: name, count: sizeof(m->u.user.name)); |
772 | |
773 | *size += off; |
774 | *dstptr += msize; |
775 | } |
776 | EXPORT_SYMBOL_GPL(xt_compat_match_from_user); |
777 | |
778 | #define COMPAT_XT_DATA_TO_USER(U, K, TYPE, C_SIZE) \ |
779 | xt_data_to_user(U->data, K->data, \ |
780 | K->u.kernel.TYPE->usersize, \ |
781 | C_SIZE, \ |
782 | COMPAT_XT_ALIGN(C_SIZE)) |
783 | |
784 | int xt_compat_match_to_user(const struct xt_entry_match *m, |
785 | void __user **dstptr, unsigned int *size) |
786 | { |
787 | const struct xt_match *match = m->u.kernel.match; |
788 | struct compat_xt_entry_match __user *cm = *dstptr; |
789 | int off = xt_compat_match_offset(match); |
790 | u_int16_t msize = m->u.user.match_size - off; |
791 | |
792 | if (XT_OBJ_TO_USER(cm, m, match, msize)) |
793 | return -EFAULT; |
794 | |
795 | if (match->compat_to_user) { |
796 | if (match->compat_to_user((void __user *)cm->data, m->data)) |
797 | return -EFAULT; |
798 | } else { |
799 | if (COMPAT_XT_DATA_TO_USER(cm, m, match, msize - sizeof(*cm))) |
800 | return -EFAULT; |
801 | } |
802 | |
803 | *size -= off; |
804 | *dstptr += msize; |
805 | return 0; |
806 | } |
807 | EXPORT_SYMBOL_GPL(xt_compat_match_to_user); |
808 | |
809 | /* non-compat version may have padding after verdict */ |
810 | struct compat_xt_standard_target { |
811 | struct compat_xt_entry_target t; |
812 | compat_uint_t verdict; |
813 | }; |
814 | |
815 | struct compat_xt_error_target { |
816 | struct compat_xt_entry_target t; |
817 | char errorname[XT_FUNCTION_MAXNAMELEN]; |
818 | }; |
819 | |
820 | int xt_compat_check_entry_offsets(const void *base, const char *elems, |
821 | unsigned int target_offset, |
822 | unsigned int next_offset) |
823 | { |
824 | long size_of_base_struct = elems - (const char *)base; |
825 | const struct compat_xt_entry_target *t; |
826 | const char *e = base; |
827 | |
828 | if (target_offset < size_of_base_struct) |
829 | return -EINVAL; |
830 | |
831 | if (target_offset + sizeof(*t) > next_offset) |
832 | return -EINVAL; |
833 | |
834 | t = (void *)(e + target_offset); |
835 | if (t->u.target_size < sizeof(*t)) |
836 | return -EINVAL; |
837 | |
838 | if (target_offset + t->u.target_size > next_offset) |
839 | return -EINVAL; |
840 | |
841 | if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0) { |
842 | const struct compat_xt_standard_target *st = (const void *)t; |
843 | |
844 | if (COMPAT_XT_ALIGN(target_offset + sizeof(*st)) != next_offset) |
845 | return -EINVAL; |
846 | |
847 | if (!verdict_ok(verdict: st->verdict)) |
848 | return -EINVAL; |
849 | } else if (strcmp(t->u.user.name, XT_ERROR_TARGET) == 0) { |
850 | const struct compat_xt_error_target *et = (const void *)t; |
851 | |
852 | if (!error_tg_ok(usersize: t->u.target_size, kernsize: sizeof(*et), |
853 | msg: et->errorname, msglen: sizeof(et->errorname))) |
854 | return -EINVAL; |
855 | } |
856 | |
857 | /* compat_xt_entry match has less strict alignment requirements, |
858 | * otherwise they are identical. In case of padding differences |
859 | * we need to add compat version of xt_check_entry_match. |
860 | */ |
861 | BUILD_BUG_ON(sizeof(struct compat_xt_entry_match) != sizeof(struct xt_entry_match)); |
862 | |
863 | return xt_check_entry_match(match: elems, target: base + target_offset, |
864 | alignment: __alignof__(struct compat_xt_entry_match)); |
865 | } |
866 | EXPORT_SYMBOL(xt_compat_check_entry_offsets); |
867 | #endif /* CONFIG_NETFILTER_XTABLES_COMPAT */ |
868 | |
869 | /** |
870 | * xt_check_entry_offsets - validate arp/ip/ip6t_entry |
871 | * |
872 | * @base: pointer to arp/ip/ip6t_entry |
873 | * @elems: pointer to first xt_entry_match, i.e. ip(6)t_entry->elems |
874 | * @target_offset: the arp/ip/ip6_t->target_offset |
875 | * @next_offset: the arp/ip/ip6_t->next_offset |
876 | * |
877 | * validates that target_offset and next_offset are sane and that all |
878 | * match sizes (if any) align with the target offset. |
879 | * |
880 | * This function does not validate the targets or matches themselves, it |
881 | * only tests that all the offsets and sizes are correct, that all |
882 | * match structures are aligned, and that the last structure ends where |
883 | * the target structure begins. |
884 | * |
885 | * Also see xt_compat_check_entry_offsets for CONFIG_NETFILTER_XTABLES_COMPAT version. |
886 | * |
887 | * The arp/ip/ip6t_entry structure @base must have passed following tests: |
888 | * - it must point to a valid memory location |
889 | * - base to base + next_offset must be accessible, i.e. not exceed allocated |
890 | * length. |
891 | * |
892 | * A well-formed entry looks like this: |
893 | * |
894 | * ip(6)t_entry match [mtdata] match [mtdata] target [tgdata] ip(6)t_entry |
895 | * e->elems[]-----' | | |
896 | * matchsize | | |
897 | * matchsize | | |
898 | * | | |
899 | * target_offset---------------------------------' | |
900 | * next_offset---------------------------------------------------' |
901 | * |
902 | * elems[]: flexible array member at end of ip(6)/arpt_entry struct. |
903 | * This is where matches (if any) and the target reside. |
904 | * target_offset: beginning of target. |
905 | * next_offset: start of the next rule; also: size of this rule. |
906 | * Since targets have a minimum size, target_offset + minlen <= next_offset. |
907 | * |
908 | * Every match stores its size, sum of sizes must not exceed target_offset. |
909 | * |
910 | * Return: 0 on success, negative errno on failure. |
911 | */ |
912 | int xt_check_entry_offsets(const void *base, |
913 | const char *elems, |
914 | unsigned int target_offset, |
915 | unsigned int next_offset) |
916 | { |
917 | long size_of_base_struct = elems - (const char *)base; |
918 | const struct xt_entry_target *t; |
919 | const char *e = base; |
920 | |
921 | /* target start is within the ip/ip6/arpt_entry struct */ |
922 | if (target_offset < size_of_base_struct) |
923 | return -EINVAL; |
924 | |
925 | if (target_offset + sizeof(*t) > next_offset) |
926 | return -EINVAL; |
927 | |
928 | t = (void *)(e + target_offset); |
929 | if (t->u.target_size < sizeof(*t)) |
930 | return -EINVAL; |
931 | |
932 | if (target_offset + t->u.target_size > next_offset) |
933 | return -EINVAL; |
934 | |
935 | if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0) { |
936 | const struct xt_standard_target *st = (const void *)t; |
937 | |
938 | if (XT_ALIGN(target_offset + sizeof(*st)) != next_offset) |
939 | return -EINVAL; |
940 | |
941 | if (!verdict_ok(verdict: st->verdict)) |
942 | return -EINVAL; |
943 | } else if (strcmp(t->u.user.name, XT_ERROR_TARGET) == 0) { |
944 | const struct xt_error_target *et = (const void *)t; |
945 | |
946 | if (!error_tg_ok(usersize: t->u.target_size, kernsize: sizeof(*et), |
947 | msg: et->errorname, msglen: sizeof(et->errorname))) |
948 | return -EINVAL; |
949 | } |
950 | |
951 | return xt_check_entry_match(match: elems, target: base + target_offset, |
952 | alignment: __alignof__(struct xt_entry_match)); |
953 | } |
954 | EXPORT_SYMBOL(xt_check_entry_offsets); |
955 | |
956 | /** |
957 | * xt_alloc_entry_offsets - allocate array to store rule head offsets |
958 | * |
959 | * @size: number of entries |
960 | * |
961 | * Return: NULL or zeroed kmalloc'd or vmalloc'd array |
962 | */ |
963 | unsigned int *xt_alloc_entry_offsets(unsigned int size) |
964 | { |
965 | if (size > XT_MAX_TABLE_SIZE / sizeof(unsigned int)) |
966 | return NULL; |
967 | |
968 | return kvcalloc(n: size, size: sizeof(unsigned int), GFP_KERNEL); |
969 | |
970 | } |
971 | EXPORT_SYMBOL(xt_alloc_entry_offsets); |
972 | |
973 | /** |
974 | * xt_find_jump_offset - check if target is a valid jump offset |
975 | * |
976 | * @offsets: array containing all valid rule start offsets of a rule blob |
977 | * @target: the jump target to search for |
978 | * @size: entries in @offset |
979 | */ |
980 | bool xt_find_jump_offset(const unsigned int *offsets, |
981 | unsigned int target, unsigned int size) |
982 | { |
983 | int m, low = 0, hi = size; |
984 | |
985 | while (hi > low) { |
986 | m = (low + hi) / 2u; |
987 | |
988 | if (offsets[m] > target) |
989 | hi = m; |
990 | else if (offsets[m] < target) |
991 | low = m + 1; |
992 | else |
993 | return true; |
994 | } |
995 | |
996 | return false; |
997 | } |
998 | EXPORT_SYMBOL(xt_find_jump_offset); |
999 | |
1000 | int xt_check_target(struct xt_tgchk_param *par, |
1001 | unsigned int size, u16 proto, bool inv_proto) |
1002 | { |
1003 | int ret; |
1004 | |
1005 | if (XT_ALIGN(par->target->targetsize) != size) { |
1006 | pr_err_ratelimited("%s_tables: %s.%u target: invalid size %u (kernel) != (user) %u\n" , |
1007 | xt_prefix[par->family], par->target->name, |
1008 | par->target->revision, |
1009 | XT_ALIGN(par->target->targetsize), size); |
1010 | return -EINVAL; |
1011 | } |
1012 | if (par->target->table != NULL && |
1013 | strcmp(par->target->table, par->table) != 0) { |
1014 | pr_info_ratelimited("%s_tables: %s target: only valid in %s table, not %s\n" , |
1015 | xt_prefix[par->family], par->target->name, |
1016 | par->target->table, par->table); |
1017 | return -EINVAL; |
1018 | } |
1019 | if (par->target->hooks && (par->hook_mask & ~par->target->hooks) != 0) { |
1020 | char used[64], allow[64]; |
1021 | |
1022 | pr_info_ratelimited("%s_tables: %s target: used from hooks %s, but only usable from %s\n" , |
1023 | xt_prefix[par->family], par->target->name, |
1024 | textify_hooks(used, sizeof(used), |
1025 | par->hook_mask, par->family), |
1026 | textify_hooks(allow, sizeof(allow), |
1027 | par->target->hooks, |
1028 | par->family)); |
1029 | return -EINVAL; |
1030 | } |
1031 | if (par->target->proto && (par->target->proto != proto || inv_proto)) { |
1032 | pr_info_ratelimited("%s_tables: %s target: only valid for protocol %u\n" , |
1033 | xt_prefix[par->family], par->target->name, |
1034 | par->target->proto); |
1035 | return -EINVAL; |
1036 | } |
1037 | if (par->target->checkentry != NULL) { |
1038 | ret = par->target->checkentry(par); |
1039 | if (ret < 0) |
1040 | return ret; |
1041 | else if (ret > 0) |
1042 | /* Flag up potential errors. */ |
1043 | return -EIO; |
1044 | } |
1045 | return 0; |
1046 | } |
1047 | EXPORT_SYMBOL_GPL(xt_check_target); |
1048 | |
1049 | /** |
1050 | * xt_copy_counters - copy counters and metadata from a sockptr_t |
1051 | * |
1052 | * @arg: src sockptr |
1053 | * @len: alleged size of userspace memory |
1054 | * @info: where to store the xt_counters_info metadata |
1055 | * |
1056 | * Copies counter meta data from @user and stores it in @info. |
1057 | * |
1058 | * vmallocs memory to hold the counters, then copies the counter data |
1059 | * from @user to the new memory and returns a pointer to it. |
1060 | * |
1061 | * If called from a compat syscall, @info gets converted automatically to the |
1062 | * 64bit representation. |
1063 | * |
1064 | * The metadata associated with the counters is stored in @info. |
1065 | * |
1066 | * Return: returns pointer that caller has to test via IS_ERR(). |
1067 | * If IS_ERR is false, caller has to vfree the pointer. |
1068 | */ |
1069 | void *xt_copy_counters(sockptr_t arg, unsigned int len, |
1070 | struct xt_counters_info *info) |
1071 | { |
1072 | size_t offset; |
1073 | void *mem; |
1074 | u64 size; |
1075 | |
1076 | #ifdef CONFIG_NETFILTER_XTABLES_COMPAT |
1077 | if (in_compat_syscall()) { |
1078 | /* structures only differ in size due to alignment */ |
1079 | struct compat_xt_counters_info compat_tmp; |
1080 | |
1081 | if (len <= sizeof(compat_tmp)) |
1082 | return ERR_PTR(error: -EINVAL); |
1083 | |
1084 | len -= sizeof(compat_tmp); |
1085 | if (copy_from_sockptr(dst: &compat_tmp, src: arg, size: sizeof(compat_tmp)) != 0) |
1086 | return ERR_PTR(error: -EFAULT); |
1087 | |
1088 | memcpy(info->name, compat_tmp.name, sizeof(info->name) - 1); |
1089 | info->num_counters = compat_tmp.num_counters; |
1090 | offset = sizeof(compat_tmp); |
1091 | } else |
1092 | #endif |
1093 | { |
1094 | if (len <= sizeof(*info)) |
1095 | return ERR_PTR(error: -EINVAL); |
1096 | |
1097 | len -= sizeof(*info); |
1098 | if (copy_from_sockptr(dst: info, src: arg, size: sizeof(*info)) != 0) |
1099 | return ERR_PTR(error: -EFAULT); |
1100 | |
1101 | offset = sizeof(*info); |
1102 | } |
1103 | info->name[sizeof(info->name) - 1] = '\0'; |
1104 | |
1105 | size = sizeof(struct xt_counters); |
1106 | size *= info->num_counters; |
1107 | |
1108 | if (size != (u64)len) |
1109 | return ERR_PTR(error: -EINVAL); |
1110 | |
1111 | mem = vmalloc(size: len); |
1112 | if (!mem) |
1113 | return ERR_PTR(error: -ENOMEM); |
1114 | |
1115 | if (copy_from_sockptr_offset(dst: mem, src: arg, offset, size: len) == 0) |
1116 | return mem; |
1117 | |
1118 | vfree(addr: mem); |
1119 | return ERR_PTR(error: -EFAULT); |
1120 | } |
1121 | EXPORT_SYMBOL_GPL(xt_copy_counters); |
1122 | |
1123 | #ifdef CONFIG_NETFILTER_XTABLES_COMPAT |
1124 | int xt_compat_target_offset(const struct xt_target *target) |
1125 | { |
1126 | u_int16_t csize = target->compatsize ? : target->targetsize; |
1127 | return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize); |
1128 | } |
1129 | EXPORT_SYMBOL_GPL(xt_compat_target_offset); |
1130 | |
1131 | void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr, |
1132 | unsigned int *size) |
1133 | { |
1134 | const struct xt_target *target = t->u.kernel.target; |
1135 | struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t; |
1136 | int off = xt_compat_target_offset(target); |
1137 | u_int16_t tsize = ct->u.user.target_size; |
1138 | char name[sizeof(t->u.user.name)]; |
1139 | |
1140 | t = *dstptr; |
1141 | memcpy(t, ct, sizeof(*ct)); |
1142 | if (target->compat_from_user) |
1143 | target->compat_from_user(t->data, ct->data); |
1144 | else |
1145 | memcpy(t->data, ct->data, tsize - sizeof(*ct)); |
1146 | |
1147 | tsize += off; |
1148 | t->u.user.target_size = tsize; |
1149 | strscpy(p: name, q: target->name, size: sizeof(name)); |
1150 | module_put(module: target->me); |
1151 | strscpy_pad(dest: t->u.user.name, src: name, count: sizeof(t->u.user.name)); |
1152 | |
1153 | *size += off; |
1154 | *dstptr += tsize; |
1155 | } |
1156 | EXPORT_SYMBOL_GPL(xt_compat_target_from_user); |
1157 | |
1158 | int xt_compat_target_to_user(const struct xt_entry_target *t, |
1159 | void __user **dstptr, unsigned int *size) |
1160 | { |
1161 | const struct xt_target *target = t->u.kernel.target; |
1162 | struct compat_xt_entry_target __user *ct = *dstptr; |
1163 | int off = xt_compat_target_offset(target); |
1164 | u_int16_t tsize = t->u.user.target_size - off; |
1165 | |
1166 | if (XT_OBJ_TO_USER(ct, t, target, tsize)) |
1167 | return -EFAULT; |
1168 | |
1169 | if (target->compat_to_user) { |
1170 | if (target->compat_to_user((void __user *)ct->data, t->data)) |
1171 | return -EFAULT; |
1172 | } else { |
1173 | if (COMPAT_XT_DATA_TO_USER(ct, t, target, tsize - sizeof(*ct))) |
1174 | return -EFAULT; |
1175 | } |
1176 | |
1177 | *size -= off; |
1178 | *dstptr += tsize; |
1179 | return 0; |
1180 | } |
1181 | EXPORT_SYMBOL_GPL(xt_compat_target_to_user); |
1182 | #endif |
1183 | |
1184 | struct xt_table_info *xt_alloc_table_info(unsigned int size) |
1185 | { |
1186 | struct xt_table_info *info = NULL; |
1187 | size_t sz = sizeof(*info) + size; |
1188 | |
1189 | if (sz < sizeof(*info) || sz >= XT_MAX_TABLE_SIZE) |
1190 | return NULL; |
1191 | |
1192 | info = kvmalloc(size: sz, GFP_KERNEL_ACCOUNT); |
1193 | if (!info) |
1194 | return NULL; |
1195 | |
1196 | memset(info, 0, sizeof(*info)); |
1197 | info->size = size; |
1198 | return info; |
1199 | } |
1200 | EXPORT_SYMBOL(xt_alloc_table_info); |
1201 | |
1202 | void xt_free_table_info(struct xt_table_info *info) |
1203 | { |
1204 | int cpu; |
1205 | |
1206 | if (info->jumpstack != NULL) { |
1207 | for_each_possible_cpu(cpu) |
1208 | kvfree(addr: info->jumpstack[cpu]); |
1209 | kvfree(addr: info->jumpstack); |
1210 | } |
1211 | |
1212 | kvfree(addr: info); |
1213 | } |
1214 | EXPORT_SYMBOL(xt_free_table_info); |
1215 | |
1216 | struct xt_table *xt_find_table(struct net *net, u8 af, const char *name) |
1217 | { |
1218 | struct xt_pernet *xt_net = net_generic(net, id: xt_pernet_id); |
1219 | struct xt_table *t; |
1220 | |
1221 | mutex_lock(&xt[af].mutex); |
1222 | list_for_each_entry(t, &xt_net->tables[af], list) { |
1223 | if (strcmp(t->name, name) == 0) { |
1224 | mutex_unlock(lock: &xt[af].mutex); |
1225 | return t; |
1226 | } |
1227 | } |
1228 | mutex_unlock(lock: &xt[af].mutex); |
1229 | return NULL; |
1230 | } |
1231 | EXPORT_SYMBOL(xt_find_table); |
1232 | |
1233 | /* Find table by name, grabs mutex & ref. Returns ERR_PTR on error. */ |
1234 | struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af, |
1235 | const char *name) |
1236 | { |
1237 | struct xt_pernet *xt_net = net_generic(net, id: xt_pernet_id); |
1238 | struct module *owner = NULL; |
1239 | struct xt_template *tmpl; |
1240 | struct xt_table *t; |
1241 | |
1242 | mutex_lock(&xt[af].mutex); |
1243 | list_for_each_entry(t, &xt_net->tables[af], list) |
1244 | if (strcmp(t->name, name) == 0 && try_module_get(module: t->me)) |
1245 | return t; |
1246 | |
1247 | /* Table doesn't exist in this netns, check larval list */ |
1248 | list_for_each_entry(tmpl, &xt_templates[af], list) { |
1249 | int err; |
1250 | |
1251 | if (strcmp(tmpl->name, name)) |
1252 | continue; |
1253 | if (!try_module_get(module: tmpl->me)) |
1254 | goto out; |
1255 | |
1256 | owner = tmpl->me; |
1257 | |
1258 | mutex_unlock(lock: &xt[af].mutex); |
1259 | err = tmpl->table_init(net); |
1260 | if (err < 0) { |
1261 | module_put(module: owner); |
1262 | return ERR_PTR(error: err); |
1263 | } |
1264 | |
1265 | mutex_lock(&xt[af].mutex); |
1266 | break; |
1267 | } |
1268 | |
1269 | /* and once again: */ |
1270 | list_for_each_entry(t, &xt_net->tables[af], list) |
1271 | if (strcmp(t->name, name) == 0) |
1272 | return t; |
1273 | |
1274 | module_put(module: owner); |
1275 | out: |
1276 | mutex_unlock(lock: &xt[af].mutex); |
1277 | return ERR_PTR(error: -ENOENT); |
1278 | } |
1279 | EXPORT_SYMBOL_GPL(xt_find_table_lock); |
1280 | |
1281 | struct xt_table *xt_request_find_table_lock(struct net *net, u_int8_t af, |
1282 | const char *name) |
1283 | { |
1284 | struct xt_table *t = xt_find_table_lock(net, af, name); |
1285 | |
1286 | #ifdef CONFIG_MODULES |
1287 | if (IS_ERR(ptr: t)) { |
1288 | int err = request_module("%stable_%s" , xt_prefix[af], name); |
1289 | if (err < 0) |
1290 | return ERR_PTR(error: err); |
1291 | t = xt_find_table_lock(net, af, name); |
1292 | } |
1293 | #endif |
1294 | |
1295 | return t; |
1296 | } |
1297 | EXPORT_SYMBOL_GPL(xt_request_find_table_lock); |
1298 | |
1299 | void xt_table_unlock(struct xt_table *table) |
1300 | { |
1301 | mutex_unlock(lock: &xt[table->af].mutex); |
1302 | } |
1303 | EXPORT_SYMBOL_GPL(xt_table_unlock); |
1304 | |
1305 | #ifdef CONFIG_NETFILTER_XTABLES_COMPAT |
1306 | void xt_compat_lock(u_int8_t af) |
1307 | { |
1308 | mutex_lock(&xt[af].compat_mutex); |
1309 | } |
1310 | EXPORT_SYMBOL_GPL(xt_compat_lock); |
1311 | |
1312 | void xt_compat_unlock(u_int8_t af) |
1313 | { |
1314 | mutex_unlock(lock: &xt[af].compat_mutex); |
1315 | } |
1316 | EXPORT_SYMBOL_GPL(xt_compat_unlock); |
1317 | #endif |
1318 | |
1319 | DEFINE_PER_CPU(seqcount_t, xt_recseq); |
1320 | EXPORT_PER_CPU_SYMBOL_GPL(xt_recseq); |
1321 | |
1322 | struct static_key xt_tee_enabled __read_mostly; |
1323 | EXPORT_SYMBOL_GPL(xt_tee_enabled); |
1324 | |
1325 | static int xt_jumpstack_alloc(struct xt_table_info *i) |
1326 | { |
1327 | unsigned int size; |
1328 | int cpu; |
1329 | |
1330 | size = sizeof(void **) * nr_cpu_ids; |
1331 | if (size > PAGE_SIZE) |
1332 | i->jumpstack = kvzalloc(size, GFP_KERNEL); |
1333 | else |
1334 | i->jumpstack = kzalloc(size, GFP_KERNEL); |
1335 | if (i->jumpstack == NULL) |
1336 | return -ENOMEM; |
1337 | |
1338 | /* ruleset without jumps -- no stack needed */ |
1339 | if (i->stacksize == 0) |
1340 | return 0; |
1341 | |
1342 | /* Jumpstack needs to be able to record two full callchains, one |
1343 | * from the first rule set traversal, plus one table reentrancy |
1344 | * via -j TEE without clobbering the callchain that brought us to |
1345 | * TEE target. |
1346 | * |
1347 | * This is done by allocating two jumpstacks per cpu, on reentry |
1348 | * the upper half of the stack is used. |
1349 | * |
1350 | * see the jumpstack setup in ipt_do_table() for more details. |
1351 | */ |
1352 | size = sizeof(void *) * i->stacksize * 2u; |
1353 | for_each_possible_cpu(cpu) { |
1354 | i->jumpstack[cpu] = kvmalloc_node(size, GFP_KERNEL, |
1355 | cpu_to_node(cpu)); |
1356 | if (i->jumpstack[cpu] == NULL) |
1357 | /* |
1358 | * Freeing will be done later on by the callers. The |
1359 | * chain is: xt_replace_table -> __do_replace -> |
1360 | * do_replace -> xt_free_table_info. |
1361 | */ |
1362 | return -ENOMEM; |
1363 | } |
1364 | |
1365 | return 0; |
1366 | } |
1367 | |
1368 | struct xt_counters *xt_counters_alloc(unsigned int counters) |
1369 | { |
1370 | struct xt_counters *mem; |
1371 | |
1372 | if (counters == 0 || counters > INT_MAX / sizeof(*mem)) |
1373 | return NULL; |
1374 | |
1375 | counters *= sizeof(*mem); |
1376 | if (counters > XT_MAX_TABLE_SIZE) |
1377 | return NULL; |
1378 | |
1379 | return vzalloc(size: counters); |
1380 | } |
1381 | EXPORT_SYMBOL(xt_counters_alloc); |
1382 | |
1383 | struct xt_table_info * |
1384 | xt_replace_table(struct xt_table *table, |
1385 | unsigned int num_counters, |
1386 | struct xt_table_info *newinfo, |
1387 | int *error) |
1388 | { |
1389 | struct xt_table_info *private; |
1390 | unsigned int cpu; |
1391 | int ret; |
1392 | |
1393 | ret = xt_jumpstack_alloc(i: newinfo); |
1394 | if (ret < 0) { |
1395 | *error = ret; |
1396 | return NULL; |
1397 | } |
1398 | |
1399 | /* Do the substitution. */ |
1400 | local_bh_disable(); |
1401 | private = table->private; |
1402 | |
1403 | /* Check inside lock: is the old number correct? */ |
1404 | if (num_counters != private->number) { |
1405 | pr_debug("num_counters != table->private->number (%u/%u)\n" , |
1406 | num_counters, private->number); |
1407 | local_bh_enable(); |
1408 | *error = -EAGAIN; |
1409 | return NULL; |
1410 | } |
1411 | |
1412 | newinfo->initial_entries = private->initial_entries; |
1413 | /* |
1414 | * Ensure contents of newinfo are visible before assigning to |
1415 | * private. |
1416 | */ |
1417 | smp_wmb(); |
1418 | table->private = newinfo; |
1419 | |
1420 | /* make sure all cpus see new ->private value */ |
1421 | smp_mb(); |
1422 | |
1423 | /* |
1424 | * Even though table entries have now been swapped, other CPU's |
1425 | * may still be using the old entries... |
1426 | */ |
1427 | local_bh_enable(); |
1428 | |
1429 | /* ... so wait for even xt_recseq on all cpus */ |
1430 | for_each_possible_cpu(cpu) { |
1431 | seqcount_t *s = &per_cpu(xt_recseq, cpu); |
1432 | u32 seq = raw_read_seqcount(s); |
1433 | |
1434 | if (seq & 1) { |
1435 | do { |
1436 | cond_resched(); |
1437 | cpu_relax(); |
1438 | } while (seq == raw_read_seqcount(s)); |
1439 | } |
1440 | } |
1441 | |
1442 | audit_log_nfcfg(name: table->name, af: table->af, nentries: private->number, |
1443 | op: !private->number ? AUDIT_XT_OP_REGISTER : |
1444 | AUDIT_XT_OP_REPLACE, |
1445 | GFP_KERNEL); |
1446 | return private; |
1447 | } |
1448 | EXPORT_SYMBOL_GPL(xt_replace_table); |
1449 | |
1450 | struct xt_table *xt_register_table(struct net *net, |
1451 | const struct xt_table *input_table, |
1452 | struct xt_table_info *bootstrap, |
1453 | struct xt_table_info *newinfo) |
1454 | { |
1455 | struct xt_pernet *xt_net = net_generic(net, id: xt_pernet_id); |
1456 | struct xt_table_info *private; |
1457 | struct xt_table *t, *table; |
1458 | int ret; |
1459 | |
1460 | /* Don't add one object to multiple lists. */ |
1461 | table = kmemdup(p: input_table, size: sizeof(struct xt_table), GFP_KERNEL); |
1462 | if (!table) { |
1463 | ret = -ENOMEM; |
1464 | goto out; |
1465 | } |
1466 | |
1467 | mutex_lock(&xt[table->af].mutex); |
1468 | /* Don't autoload: we'd eat our tail... */ |
1469 | list_for_each_entry(t, &xt_net->tables[table->af], list) { |
1470 | if (strcmp(t->name, table->name) == 0) { |
1471 | ret = -EEXIST; |
1472 | goto unlock; |
1473 | } |
1474 | } |
1475 | |
1476 | /* Simplifies replace_table code. */ |
1477 | table->private = bootstrap; |
1478 | |
1479 | if (!xt_replace_table(table, 0, newinfo, &ret)) |
1480 | goto unlock; |
1481 | |
1482 | private = table->private; |
1483 | pr_debug("table->private->number = %u\n" , private->number); |
1484 | |
1485 | /* save number of initial entries */ |
1486 | private->initial_entries = private->number; |
1487 | |
1488 | list_add(new: &table->list, head: &xt_net->tables[table->af]); |
1489 | mutex_unlock(lock: &xt[table->af].mutex); |
1490 | return table; |
1491 | |
1492 | unlock: |
1493 | mutex_unlock(lock: &xt[table->af].mutex); |
1494 | kfree(objp: table); |
1495 | out: |
1496 | return ERR_PTR(error: ret); |
1497 | } |
1498 | EXPORT_SYMBOL_GPL(xt_register_table); |
1499 | |
1500 | void *xt_unregister_table(struct xt_table *table) |
1501 | { |
1502 | struct xt_table_info *private; |
1503 | |
1504 | mutex_lock(&xt[table->af].mutex); |
1505 | private = table->private; |
1506 | list_del(entry: &table->list); |
1507 | mutex_unlock(lock: &xt[table->af].mutex); |
1508 | audit_log_nfcfg(name: table->name, af: table->af, nentries: private->number, |
1509 | op: AUDIT_XT_OP_UNREGISTER, GFP_KERNEL); |
1510 | kfree(objp: table->ops); |
1511 | kfree(objp: table); |
1512 | |
1513 | return private; |
1514 | } |
1515 | EXPORT_SYMBOL_GPL(xt_unregister_table); |
1516 | |
1517 | #ifdef CONFIG_PROC_FS |
1518 | static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos) |
1519 | { |
1520 | u8 af = (unsigned long)pde_data(inode: file_inode(f: seq->file)); |
1521 | struct net *net = seq_file_net(seq); |
1522 | struct xt_pernet *xt_net; |
1523 | |
1524 | xt_net = net_generic(net, id: xt_pernet_id); |
1525 | |
1526 | mutex_lock(&xt[af].mutex); |
1527 | return seq_list_start(head: &xt_net->tables[af], pos: *pos); |
1528 | } |
1529 | |
1530 | static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
1531 | { |
1532 | u8 af = (unsigned long)pde_data(inode: file_inode(f: seq->file)); |
1533 | struct net *net = seq_file_net(seq); |
1534 | struct xt_pernet *xt_net; |
1535 | |
1536 | xt_net = net_generic(net, id: xt_pernet_id); |
1537 | |
1538 | return seq_list_next(v, head: &xt_net->tables[af], ppos: pos); |
1539 | } |
1540 | |
1541 | static void xt_table_seq_stop(struct seq_file *seq, void *v) |
1542 | { |
1543 | u_int8_t af = (unsigned long)pde_data(inode: file_inode(f: seq->file)); |
1544 | |
1545 | mutex_unlock(lock: &xt[af].mutex); |
1546 | } |
1547 | |
1548 | static int xt_table_seq_show(struct seq_file *seq, void *v) |
1549 | { |
1550 | struct xt_table *table = list_entry(v, struct xt_table, list); |
1551 | |
1552 | if (*table->name) |
1553 | seq_printf(m: seq, fmt: "%s\n" , table->name); |
1554 | return 0; |
1555 | } |
1556 | |
1557 | static const struct seq_operations xt_table_seq_ops = { |
1558 | .start = xt_table_seq_start, |
1559 | .next = xt_table_seq_next, |
1560 | .stop = xt_table_seq_stop, |
1561 | .show = xt_table_seq_show, |
1562 | }; |
1563 | |
1564 | /* |
1565 | * Traverse state for ip{,6}_{tables,matches} for helping crossing |
1566 | * the multi-AF mutexes. |
1567 | */ |
1568 | struct nf_mttg_trav { |
1569 | struct list_head *head, *curr; |
1570 | uint8_t class; |
1571 | }; |
1572 | |
1573 | enum { |
1574 | MTTG_TRAV_INIT, |
1575 | MTTG_TRAV_NFP_UNSPEC, |
1576 | MTTG_TRAV_NFP_SPEC, |
1577 | MTTG_TRAV_DONE, |
1578 | }; |
1579 | |
1580 | static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos, |
1581 | bool is_target) |
1582 | { |
1583 | static const uint8_t next_class[] = { |
1584 | [MTTG_TRAV_NFP_UNSPEC] = MTTG_TRAV_NFP_SPEC, |
1585 | [MTTG_TRAV_NFP_SPEC] = MTTG_TRAV_DONE, |
1586 | }; |
1587 | uint8_t nfproto = (unsigned long)pde_data(inode: file_inode(f: seq->file)); |
1588 | struct nf_mttg_trav *trav = seq->private; |
1589 | |
1590 | if (ppos != NULL) |
1591 | ++(*ppos); |
1592 | |
1593 | switch (trav->class) { |
1594 | case MTTG_TRAV_INIT: |
1595 | trav->class = MTTG_TRAV_NFP_UNSPEC; |
1596 | mutex_lock(&xt[NFPROTO_UNSPEC].mutex); |
1597 | trav->head = trav->curr = is_target ? |
1598 | &xt[NFPROTO_UNSPEC].target : &xt[NFPROTO_UNSPEC].match; |
1599 | break; |
1600 | case MTTG_TRAV_NFP_UNSPEC: |
1601 | trav->curr = trav->curr->next; |
1602 | if (trav->curr != trav->head) |
1603 | break; |
1604 | mutex_unlock(lock: &xt[NFPROTO_UNSPEC].mutex); |
1605 | mutex_lock(&xt[nfproto].mutex); |
1606 | trav->head = trav->curr = is_target ? |
1607 | &xt[nfproto].target : &xt[nfproto].match; |
1608 | trav->class = next_class[trav->class]; |
1609 | break; |
1610 | case MTTG_TRAV_NFP_SPEC: |
1611 | trav->curr = trav->curr->next; |
1612 | if (trav->curr != trav->head) |
1613 | break; |
1614 | fallthrough; |
1615 | default: |
1616 | return NULL; |
1617 | } |
1618 | return trav; |
1619 | } |
1620 | |
1621 | static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos, |
1622 | bool is_target) |
1623 | { |
1624 | struct nf_mttg_trav *trav = seq->private; |
1625 | unsigned int j; |
1626 | |
1627 | trav->class = MTTG_TRAV_INIT; |
1628 | for (j = 0; j < *pos; ++j) |
1629 | if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL) |
1630 | return NULL; |
1631 | return trav; |
1632 | } |
1633 | |
1634 | static void xt_mttg_seq_stop(struct seq_file *seq, void *v) |
1635 | { |
1636 | uint8_t nfproto = (unsigned long)pde_data(inode: file_inode(f: seq->file)); |
1637 | struct nf_mttg_trav *trav = seq->private; |
1638 | |
1639 | switch (trav->class) { |
1640 | case MTTG_TRAV_NFP_UNSPEC: |
1641 | mutex_unlock(lock: &xt[NFPROTO_UNSPEC].mutex); |
1642 | break; |
1643 | case MTTG_TRAV_NFP_SPEC: |
1644 | mutex_unlock(lock: &xt[nfproto].mutex); |
1645 | break; |
1646 | } |
1647 | } |
1648 | |
1649 | static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos) |
1650 | { |
1651 | return xt_mttg_seq_start(seq, pos, is_target: false); |
1652 | } |
1653 | |
1654 | static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *ppos) |
1655 | { |
1656 | return xt_mttg_seq_next(seq, v, ppos, is_target: false); |
1657 | } |
1658 | |
1659 | static int xt_match_seq_show(struct seq_file *seq, void *v) |
1660 | { |
1661 | const struct nf_mttg_trav *trav = seq->private; |
1662 | const struct xt_match *match; |
1663 | |
1664 | switch (trav->class) { |
1665 | case MTTG_TRAV_NFP_UNSPEC: |
1666 | case MTTG_TRAV_NFP_SPEC: |
1667 | if (trav->curr == trav->head) |
1668 | return 0; |
1669 | match = list_entry(trav->curr, struct xt_match, list); |
1670 | if (*match->name) |
1671 | seq_printf(m: seq, fmt: "%s\n" , match->name); |
1672 | } |
1673 | return 0; |
1674 | } |
1675 | |
1676 | static const struct seq_operations xt_match_seq_ops = { |
1677 | .start = xt_match_seq_start, |
1678 | .next = xt_match_seq_next, |
1679 | .stop = xt_mttg_seq_stop, |
1680 | .show = xt_match_seq_show, |
1681 | }; |
1682 | |
1683 | static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos) |
1684 | { |
1685 | return xt_mttg_seq_start(seq, pos, is_target: true); |
1686 | } |
1687 | |
1688 | static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *ppos) |
1689 | { |
1690 | return xt_mttg_seq_next(seq, v, ppos, is_target: true); |
1691 | } |
1692 | |
1693 | static int xt_target_seq_show(struct seq_file *seq, void *v) |
1694 | { |
1695 | const struct nf_mttg_trav *trav = seq->private; |
1696 | const struct xt_target *target; |
1697 | |
1698 | switch (trav->class) { |
1699 | case MTTG_TRAV_NFP_UNSPEC: |
1700 | case MTTG_TRAV_NFP_SPEC: |
1701 | if (trav->curr == trav->head) |
1702 | return 0; |
1703 | target = list_entry(trav->curr, struct xt_target, list); |
1704 | if (*target->name) |
1705 | seq_printf(m: seq, fmt: "%s\n" , target->name); |
1706 | } |
1707 | return 0; |
1708 | } |
1709 | |
1710 | static const struct seq_operations xt_target_seq_ops = { |
1711 | .start = xt_target_seq_start, |
1712 | .next = xt_target_seq_next, |
1713 | .stop = xt_mttg_seq_stop, |
1714 | .show = xt_target_seq_show, |
1715 | }; |
1716 | |
1717 | #define FORMAT_TABLES "_tables_names" |
1718 | #define FORMAT_MATCHES "_tables_matches" |
1719 | #define FORMAT_TARGETS "_tables_targets" |
1720 | |
1721 | #endif /* CONFIG_PROC_FS */ |
1722 | |
1723 | /** |
1724 | * xt_hook_ops_alloc - set up hooks for a new table |
1725 | * @table: table with metadata needed to set up hooks |
1726 | * @fn: Hook function |
1727 | * |
1728 | * This function will create the nf_hook_ops that the x_table needs |
1729 | * to hand to xt_hook_link_net(). |
1730 | */ |
1731 | struct nf_hook_ops * |
1732 | xt_hook_ops_alloc(const struct xt_table *table, nf_hookfn *fn) |
1733 | { |
1734 | unsigned int hook_mask = table->valid_hooks; |
1735 | uint8_t i, num_hooks = hweight32(hook_mask); |
1736 | uint8_t hooknum; |
1737 | struct nf_hook_ops *ops; |
1738 | |
1739 | if (!num_hooks) |
1740 | return ERR_PTR(error: -EINVAL); |
1741 | |
1742 | ops = kcalloc(n: num_hooks, size: sizeof(*ops), GFP_KERNEL); |
1743 | if (ops == NULL) |
1744 | return ERR_PTR(error: -ENOMEM); |
1745 | |
1746 | for (i = 0, hooknum = 0; i < num_hooks && hook_mask != 0; |
1747 | hook_mask >>= 1, ++hooknum) { |
1748 | if (!(hook_mask & 1)) |
1749 | continue; |
1750 | ops[i].hook = fn; |
1751 | ops[i].pf = table->af; |
1752 | ops[i].hooknum = hooknum; |
1753 | ops[i].priority = table->priority; |
1754 | ++i; |
1755 | } |
1756 | |
1757 | return ops; |
1758 | } |
1759 | EXPORT_SYMBOL_GPL(xt_hook_ops_alloc); |
1760 | |
1761 | int xt_register_template(const struct xt_table *table, |
1762 | int (*table_init)(struct net *net)) |
1763 | { |
1764 | int ret = -EEXIST, af = table->af; |
1765 | struct xt_template *t; |
1766 | |
1767 | mutex_lock(&xt[af].mutex); |
1768 | |
1769 | list_for_each_entry(t, &xt_templates[af], list) { |
1770 | if (WARN_ON_ONCE(strcmp(table->name, t->name) == 0)) |
1771 | goto out_unlock; |
1772 | } |
1773 | |
1774 | ret = -ENOMEM; |
1775 | t = kzalloc(size: sizeof(*t), GFP_KERNEL); |
1776 | if (!t) |
1777 | goto out_unlock; |
1778 | |
1779 | BUILD_BUG_ON(sizeof(t->name) != sizeof(table->name)); |
1780 | |
1781 | strscpy(p: t->name, q: table->name, size: sizeof(t->name)); |
1782 | t->table_init = table_init; |
1783 | t->me = table->me; |
1784 | list_add(new: &t->list, head: &xt_templates[af]); |
1785 | ret = 0; |
1786 | out_unlock: |
1787 | mutex_unlock(lock: &xt[af].mutex); |
1788 | return ret; |
1789 | } |
1790 | EXPORT_SYMBOL_GPL(xt_register_template); |
1791 | |
1792 | void xt_unregister_template(const struct xt_table *table) |
1793 | { |
1794 | struct xt_template *t; |
1795 | int af = table->af; |
1796 | |
1797 | mutex_lock(&xt[af].mutex); |
1798 | list_for_each_entry(t, &xt_templates[af], list) { |
1799 | if (strcmp(table->name, t->name)) |
1800 | continue; |
1801 | |
1802 | list_del(entry: &t->list); |
1803 | mutex_unlock(lock: &xt[af].mutex); |
1804 | kfree(objp: t); |
1805 | return; |
1806 | } |
1807 | |
1808 | mutex_unlock(lock: &xt[af].mutex); |
1809 | WARN_ON_ONCE(1); |
1810 | } |
1811 | EXPORT_SYMBOL_GPL(xt_unregister_template); |
1812 | |
1813 | int xt_proto_init(struct net *net, u_int8_t af) |
1814 | { |
1815 | #ifdef CONFIG_PROC_FS |
1816 | char buf[XT_FUNCTION_MAXNAMELEN]; |
1817 | struct proc_dir_entry *proc; |
1818 | kuid_t root_uid; |
1819 | kgid_t root_gid; |
1820 | #endif |
1821 | |
1822 | if (af >= ARRAY_SIZE(xt_prefix)) |
1823 | return -EINVAL; |
1824 | |
1825 | |
1826 | #ifdef CONFIG_PROC_FS |
1827 | root_uid = make_kuid(from: net->user_ns, uid: 0); |
1828 | root_gid = make_kgid(from: net->user_ns, gid: 0); |
1829 | |
1830 | strscpy(p: buf, q: xt_prefix[af], size: sizeof(buf)); |
1831 | strlcat(p: buf, FORMAT_TABLES, avail: sizeof(buf)); |
1832 | proc = proc_create_net_data(name: buf, mode: 0440, parent: net->proc_net, ops: &xt_table_seq_ops, |
1833 | state_size: sizeof(struct seq_net_private), |
1834 | data: (void *)(unsigned long)af); |
1835 | if (!proc) |
1836 | goto out; |
1837 | if (uid_valid(uid: root_uid) && gid_valid(gid: root_gid)) |
1838 | proc_set_user(proc, root_uid, root_gid); |
1839 | |
1840 | strscpy(p: buf, q: xt_prefix[af], size: sizeof(buf)); |
1841 | strlcat(p: buf, FORMAT_MATCHES, avail: sizeof(buf)); |
1842 | proc = proc_create_seq_private(name: buf, mode: 0440, parent: net->proc_net, |
1843 | ops: &xt_match_seq_ops, state_size: sizeof(struct nf_mttg_trav), |
1844 | data: (void *)(unsigned long)af); |
1845 | if (!proc) |
1846 | goto out_remove_tables; |
1847 | if (uid_valid(uid: root_uid) && gid_valid(gid: root_gid)) |
1848 | proc_set_user(proc, root_uid, root_gid); |
1849 | |
1850 | strscpy(p: buf, q: xt_prefix[af], size: sizeof(buf)); |
1851 | strlcat(p: buf, FORMAT_TARGETS, avail: sizeof(buf)); |
1852 | proc = proc_create_seq_private(name: buf, mode: 0440, parent: net->proc_net, |
1853 | ops: &xt_target_seq_ops, state_size: sizeof(struct nf_mttg_trav), |
1854 | data: (void *)(unsigned long)af); |
1855 | if (!proc) |
1856 | goto out_remove_matches; |
1857 | if (uid_valid(uid: root_uid) && gid_valid(gid: root_gid)) |
1858 | proc_set_user(proc, root_uid, root_gid); |
1859 | #endif |
1860 | |
1861 | return 0; |
1862 | |
1863 | #ifdef CONFIG_PROC_FS |
1864 | out_remove_matches: |
1865 | strscpy(p: buf, q: xt_prefix[af], size: sizeof(buf)); |
1866 | strlcat(p: buf, FORMAT_MATCHES, avail: sizeof(buf)); |
1867 | remove_proc_entry(buf, net->proc_net); |
1868 | |
1869 | out_remove_tables: |
1870 | strscpy(p: buf, q: xt_prefix[af], size: sizeof(buf)); |
1871 | strlcat(p: buf, FORMAT_TABLES, avail: sizeof(buf)); |
1872 | remove_proc_entry(buf, net->proc_net); |
1873 | out: |
1874 | return -1; |
1875 | #endif |
1876 | } |
1877 | EXPORT_SYMBOL_GPL(xt_proto_init); |
1878 | |
1879 | void xt_proto_fini(struct net *net, u_int8_t af) |
1880 | { |
1881 | #ifdef CONFIG_PROC_FS |
1882 | char buf[XT_FUNCTION_MAXNAMELEN]; |
1883 | |
1884 | strscpy(p: buf, q: xt_prefix[af], size: sizeof(buf)); |
1885 | strlcat(p: buf, FORMAT_TABLES, avail: sizeof(buf)); |
1886 | remove_proc_entry(buf, net->proc_net); |
1887 | |
1888 | strscpy(p: buf, q: xt_prefix[af], size: sizeof(buf)); |
1889 | strlcat(p: buf, FORMAT_TARGETS, avail: sizeof(buf)); |
1890 | remove_proc_entry(buf, net->proc_net); |
1891 | |
1892 | strscpy(p: buf, q: xt_prefix[af], size: sizeof(buf)); |
1893 | strlcat(p: buf, FORMAT_MATCHES, avail: sizeof(buf)); |
1894 | remove_proc_entry(buf, net->proc_net); |
1895 | #endif /*CONFIG_PROC_FS*/ |
1896 | } |
1897 | EXPORT_SYMBOL_GPL(xt_proto_fini); |
1898 | |
1899 | /** |
1900 | * xt_percpu_counter_alloc - allocate x_tables rule counter |
1901 | * |
1902 | * @state: pointer to xt_percpu allocation state |
1903 | * @counter: pointer to counter struct inside the ip(6)/arpt_entry struct |
1904 | * |
1905 | * On SMP, the packet counter [ ip(6)t_entry->counters.pcnt ] will then |
1906 | * contain the address of the real (percpu) counter. |
1907 | * |
1908 | * Rule evaluation needs to use xt_get_this_cpu_counter() helper |
1909 | * to fetch the real percpu counter. |
1910 | * |
1911 | * To speed up allocation and improve data locality, a 4kb block is |
1912 | * allocated. Freeing any counter may free an entire block, so all |
1913 | * counters allocated using the same state must be freed at the same |
1914 | * time. |
1915 | * |
1916 | * xt_percpu_counter_alloc_state contains the base address of the |
1917 | * allocated page and the current sub-offset. |
1918 | * |
1919 | * returns false on error. |
1920 | */ |
1921 | bool xt_percpu_counter_alloc(struct xt_percpu_counter_alloc_state *state, |
1922 | struct xt_counters *counter) |
1923 | { |
1924 | BUILD_BUG_ON(XT_PCPU_BLOCK_SIZE < (sizeof(*counter) * 2)); |
1925 | |
1926 | if (nr_cpu_ids <= 1) |
1927 | return true; |
1928 | |
1929 | if (!state->mem) { |
1930 | state->mem = __alloc_percpu(XT_PCPU_BLOCK_SIZE, |
1931 | XT_PCPU_BLOCK_SIZE); |
1932 | if (!state->mem) |
1933 | return false; |
1934 | } |
1935 | counter->pcnt = (__force unsigned long)(state->mem + state->off); |
1936 | state->off += sizeof(*counter); |
1937 | if (state->off > (XT_PCPU_BLOCK_SIZE - sizeof(*counter))) { |
1938 | state->mem = NULL; |
1939 | state->off = 0; |
1940 | } |
1941 | return true; |
1942 | } |
1943 | EXPORT_SYMBOL_GPL(xt_percpu_counter_alloc); |
1944 | |
1945 | void xt_percpu_counter_free(struct xt_counters *counters) |
1946 | { |
1947 | unsigned long pcnt = counters->pcnt; |
1948 | |
1949 | if (nr_cpu_ids > 1 && (pcnt & (XT_PCPU_BLOCK_SIZE - 1)) == 0) |
1950 | free_percpu(pdata: (void __percpu *)pcnt); |
1951 | } |
1952 | EXPORT_SYMBOL_GPL(xt_percpu_counter_free); |
1953 | |
1954 | static int __net_init xt_net_init(struct net *net) |
1955 | { |
1956 | struct xt_pernet *xt_net = net_generic(net, id: xt_pernet_id); |
1957 | int i; |
1958 | |
1959 | for (i = 0; i < NFPROTO_NUMPROTO; i++) |
1960 | INIT_LIST_HEAD(list: &xt_net->tables[i]); |
1961 | return 0; |
1962 | } |
1963 | |
1964 | static void __net_exit xt_net_exit(struct net *net) |
1965 | { |
1966 | struct xt_pernet *xt_net = net_generic(net, id: xt_pernet_id); |
1967 | int i; |
1968 | |
1969 | for (i = 0; i < NFPROTO_NUMPROTO; i++) |
1970 | WARN_ON_ONCE(!list_empty(&xt_net->tables[i])); |
1971 | } |
1972 | |
1973 | static struct pernet_operations xt_net_ops = { |
1974 | .init = xt_net_init, |
1975 | .exit = xt_net_exit, |
1976 | .id = &xt_pernet_id, |
1977 | .size = sizeof(struct xt_pernet), |
1978 | }; |
1979 | |
1980 | static int __init xt_init(void) |
1981 | { |
1982 | unsigned int i; |
1983 | int rv; |
1984 | |
1985 | for_each_possible_cpu(i) { |
1986 | seqcount_init(&per_cpu(xt_recseq, i)); |
1987 | } |
1988 | |
1989 | xt = kcalloc(n: NFPROTO_NUMPROTO, size: sizeof(struct xt_af), GFP_KERNEL); |
1990 | if (!xt) |
1991 | return -ENOMEM; |
1992 | |
1993 | for (i = 0; i < NFPROTO_NUMPROTO; i++) { |
1994 | mutex_init(&xt[i].mutex); |
1995 | #ifdef CONFIG_NETFILTER_XTABLES_COMPAT |
1996 | mutex_init(&xt[i].compat_mutex); |
1997 | xt[i].compat_tab = NULL; |
1998 | #endif |
1999 | INIT_LIST_HEAD(list: &xt[i].target); |
2000 | INIT_LIST_HEAD(list: &xt[i].match); |
2001 | INIT_LIST_HEAD(list: &xt_templates[i]); |
2002 | } |
2003 | rv = register_pernet_subsys(&xt_net_ops); |
2004 | if (rv < 0) |
2005 | kfree(objp: xt); |
2006 | return rv; |
2007 | } |
2008 | |
2009 | static void __exit xt_fini(void) |
2010 | { |
2011 | unregister_pernet_subsys(&xt_net_ops); |
2012 | kfree(objp: xt); |
2013 | } |
2014 | |
2015 | module_init(xt_init); |
2016 | module_exit(xt_fini); |
2017 | |