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