2 * x_tables core - Backend for {ip,ip6,arp}_tables
4 * Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
5 * Copyright (C) 2006-2012 Patrick McHardy <kaber@trash.net>
7 * Based on existing ip_tables code which is
8 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
9 * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/socket.h>
20 #include <linux/net.h>
21 #include <linux/proc_fs.h>
22 #include <linux/seq_file.h>
23 #include <linux/string.h>
24 #include <linux/vmalloc.h>
25 #include <linux/mutex.h>
27 #include <linux/slab.h>
28 #include <linux/audit.h>
29 #include <net/net_namespace.h>
31 #include <linux/netfilter/x_tables.h>
32 #include <linux/netfilter_arp.h>
33 #include <linux/netfilter_ipv4/ip_tables.h>
34 #include <linux/netfilter_ipv6/ip6_tables.h>
35 #include <linux/netfilter_arp/arp_tables.h>
37 MODULE_LICENSE("GPL");
38 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
39 MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module");
41 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
44 unsigned int offset; /* offset in kernel */
45 int delta; /* delta in 32bit user land */
50 struct list_head match;
51 struct list_head target;
53 struct mutex compat_mutex;
54 struct compat_delta *compat_tab;
55 unsigned int number; /* number of slots in compat_tab[] */
56 unsigned int cur; /* number of used slots in compat_tab[] */
60 static struct xt_af *xt;
62 static const char *const xt_prefix[NFPROTO_NUMPROTO] = {
63 [NFPROTO_UNSPEC] = "x",
64 [NFPROTO_IPV4] = "ip",
65 [NFPROTO_ARP] = "arp",
66 [NFPROTO_BRIDGE] = "eb",
67 [NFPROTO_IPV6] = "ip6",
70 /* Allow this many total (re)entries. */
71 static const unsigned int xt_jumpstack_multiplier = 2;
73 /* Registration hooks for targets. */
74 int xt_register_target(struct xt_target *target)
76 u_int8_t af = target->family;
78 mutex_lock(&xt[af].mutex);
79 list_add(&target->list, &xt[af].target);
80 mutex_unlock(&xt[af].mutex);
83 EXPORT_SYMBOL(xt_register_target);
86 xt_unregister_target(struct xt_target *target)
88 u_int8_t af = target->family;
90 mutex_lock(&xt[af].mutex);
91 list_del(&target->list);
92 mutex_unlock(&xt[af].mutex);
94 EXPORT_SYMBOL(xt_unregister_target);
97 xt_register_targets(struct xt_target *target, unsigned int n)
102 for (i = 0; i < n; i++) {
103 err = xt_register_target(&target[i]);
111 xt_unregister_targets(target, i);
114 EXPORT_SYMBOL(xt_register_targets);
117 xt_unregister_targets(struct xt_target *target, unsigned int n)
120 xt_unregister_target(&target[n]);
122 EXPORT_SYMBOL(xt_unregister_targets);
124 int xt_register_match(struct xt_match *match)
126 u_int8_t af = match->family;
128 mutex_lock(&xt[af].mutex);
129 list_add(&match->list, &xt[af].match);
130 mutex_unlock(&xt[af].mutex);
133 EXPORT_SYMBOL(xt_register_match);
136 xt_unregister_match(struct xt_match *match)
138 u_int8_t af = match->family;
140 mutex_lock(&xt[af].mutex);
141 list_del(&match->list);
142 mutex_unlock(&xt[af].mutex);
144 EXPORT_SYMBOL(xt_unregister_match);
147 xt_register_matches(struct xt_match *match, unsigned int n)
152 for (i = 0; i < n; i++) {
153 err = xt_register_match(&match[i]);
161 xt_unregister_matches(match, i);
164 EXPORT_SYMBOL(xt_register_matches);
167 xt_unregister_matches(struct xt_match *match, unsigned int n)
170 xt_unregister_match(&match[n]);
172 EXPORT_SYMBOL(xt_unregister_matches);
176 * These are weird, but module loading must not be done with mutex
177 * held (since they will register), and we have to have a single
181 /* Find match, grabs ref. Returns ERR_PTR() on error. */
182 struct xt_match *xt_find_match(u8 af, const char *name, u8 revision)
187 mutex_lock(&xt[af].mutex);
188 list_for_each_entry(m, &xt[af].match, list) {
189 if (strcmp(m->name, name) == 0) {
190 if (m->revision == revision) {
191 if (try_module_get(m->me)) {
192 mutex_unlock(&xt[af].mutex);
196 err = -EPROTOTYPE; /* Found something. */
199 mutex_unlock(&xt[af].mutex);
201 if (af != NFPROTO_UNSPEC)
202 /* Try searching again in the family-independent list */
203 return xt_find_match(NFPROTO_UNSPEC, name, revision);
207 EXPORT_SYMBOL(xt_find_match);
210 xt_request_find_match(uint8_t nfproto, const char *name, uint8_t revision)
212 struct xt_match *match;
214 match = xt_find_match(nfproto, name, revision);
216 request_module("%st_%s", xt_prefix[nfproto], name);
217 match = xt_find_match(nfproto, name, revision);
222 EXPORT_SYMBOL_GPL(xt_request_find_match);
224 /* Find target, grabs ref. Returns ERR_PTR() on error. */
225 struct xt_target *xt_find_target(u8 af, const char *name, u8 revision)
230 mutex_lock(&xt[af].mutex);
231 list_for_each_entry(t, &xt[af].target, list) {
232 if (strcmp(t->name, name) == 0) {
233 if (t->revision == revision) {
234 if (try_module_get(t->me)) {
235 mutex_unlock(&xt[af].mutex);
239 err = -EPROTOTYPE; /* Found something. */
242 mutex_unlock(&xt[af].mutex);
244 if (af != NFPROTO_UNSPEC)
245 /* Try searching again in the family-independent list */
246 return xt_find_target(NFPROTO_UNSPEC, name, revision);
250 EXPORT_SYMBOL(xt_find_target);
252 struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision)
254 struct xt_target *target;
256 target = xt_find_target(af, name, revision);
257 if (IS_ERR(target)) {
258 request_module("%st_%s", xt_prefix[af], name);
259 target = xt_find_target(af, name, revision);
264 EXPORT_SYMBOL_GPL(xt_request_find_target);
266 static int match_revfn(u8 af, const char *name, u8 revision, int *bestp)
268 const struct xt_match *m;
271 list_for_each_entry(m, &xt[af].match, list) {
272 if (strcmp(m->name, name) == 0) {
273 if (m->revision > *bestp)
274 *bestp = m->revision;
275 if (m->revision == revision)
280 if (af != NFPROTO_UNSPEC && !have_rev)
281 return match_revfn(NFPROTO_UNSPEC, name, revision, bestp);
286 static int target_revfn(u8 af, const char *name, u8 revision, int *bestp)
288 const struct xt_target *t;
291 list_for_each_entry(t, &xt[af].target, list) {
292 if (strcmp(t->name, name) == 0) {
293 if (t->revision > *bestp)
294 *bestp = t->revision;
295 if (t->revision == revision)
300 if (af != NFPROTO_UNSPEC && !have_rev)
301 return target_revfn(NFPROTO_UNSPEC, name, revision, bestp);
306 /* Returns true or false (if no such extension at all) */
307 int xt_find_revision(u8 af, const char *name, u8 revision, int target,
310 int have_rev, best = -1;
312 mutex_lock(&xt[af].mutex);
314 have_rev = target_revfn(af, name, revision, &best);
316 have_rev = match_revfn(af, name, revision, &best);
317 mutex_unlock(&xt[af].mutex);
319 /* Nothing at all? Return 0 to try loading module. */
327 *err = -EPROTONOSUPPORT;
330 EXPORT_SYMBOL_GPL(xt_find_revision);
333 textify_hooks(char *buf, size_t size, unsigned int mask, uint8_t nfproto)
335 static const char *const inetbr_names[] = {
336 "PREROUTING", "INPUT", "FORWARD",
337 "OUTPUT", "POSTROUTING", "BROUTING",
339 static const char *const arp_names[] = {
340 "INPUT", "FORWARD", "OUTPUT",
342 const char *const *names;
348 names = (nfproto == NFPROTO_ARP) ? arp_names : inetbr_names;
349 max = (nfproto == NFPROTO_ARP) ? ARRAY_SIZE(arp_names) :
350 ARRAY_SIZE(inetbr_names);
352 for (i = 0; i < max; ++i) {
353 if (!(mask & (1 << i)))
355 res = snprintf(p, size, "%s%s", np ? "/" : "", names[i]);
366 int xt_check_match(struct xt_mtchk_param *par,
367 unsigned int size, u_int8_t proto, bool inv_proto)
371 if (XT_ALIGN(par->match->matchsize) != size &&
372 par->match->matchsize != -1) {
374 * ebt_among is exempt from centralized matchsize checking
375 * because it uses a dynamic-size data set.
377 pr_err("%s_tables: %s.%u match: invalid size "
378 "%u (kernel) != (user) %u\n",
379 xt_prefix[par->family], par->match->name,
380 par->match->revision,
381 XT_ALIGN(par->match->matchsize), size);
384 if (par->match->table != NULL &&
385 strcmp(par->match->table, par->table) != 0) {
386 pr_err("%s_tables: %s match: only valid in %s table, not %s\n",
387 xt_prefix[par->family], par->match->name,
388 par->match->table, par->table);
391 if (par->match->hooks && (par->hook_mask & ~par->match->hooks) != 0) {
392 char used[64], allow[64];
394 pr_err("%s_tables: %s match: used from hooks %s, but only "
396 xt_prefix[par->family], par->match->name,
397 textify_hooks(used, sizeof(used), par->hook_mask,
399 textify_hooks(allow, sizeof(allow), par->match->hooks,
403 if (par->match->proto && (par->match->proto != proto || inv_proto)) {
404 pr_err("%s_tables: %s match: only valid for protocol %u\n",
405 xt_prefix[par->family], par->match->name,
409 if (par->match->checkentry != NULL) {
410 ret = par->match->checkentry(par);
414 /* Flag up potential errors. */
419 EXPORT_SYMBOL_GPL(xt_check_match);
422 int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta)
424 struct xt_af *xp = &xt[af];
426 if (!xp->compat_tab) {
429 xp->compat_tab = vmalloc(sizeof(struct compat_delta) * xp->number);
435 if (xp->cur >= xp->number)
439 delta += xp->compat_tab[xp->cur - 1].delta;
440 xp->compat_tab[xp->cur].offset = offset;
441 xp->compat_tab[xp->cur].delta = delta;
445 EXPORT_SYMBOL_GPL(xt_compat_add_offset);
447 void xt_compat_flush_offsets(u_int8_t af)
449 if (xt[af].compat_tab) {
450 vfree(xt[af].compat_tab);
451 xt[af].compat_tab = NULL;
456 EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);
458 int xt_compat_calc_jump(u_int8_t af, unsigned int offset)
460 struct compat_delta *tmp = xt[af].compat_tab;
461 int mid, left = 0, right = xt[af].cur - 1;
463 while (left <= right) {
464 mid = (left + right) >> 1;
465 if (offset > tmp[mid].offset)
467 else if (offset < tmp[mid].offset)
470 return mid ? tmp[mid - 1].delta : 0;
472 return left ? tmp[left - 1].delta : 0;
474 EXPORT_SYMBOL_GPL(xt_compat_calc_jump);
476 void xt_compat_init_offsets(u_int8_t af, unsigned int number)
478 xt[af].number = number;
481 EXPORT_SYMBOL(xt_compat_init_offsets);
483 int xt_compat_match_offset(const struct xt_match *match)
485 u_int16_t csize = match->compatsize ? : match->matchsize;
486 return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
488 EXPORT_SYMBOL_GPL(xt_compat_match_offset);
490 int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
493 const struct xt_match *match = m->u.kernel.match;
494 struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
495 int pad, off = xt_compat_match_offset(match);
496 u_int16_t msize = cm->u.user.match_size;
499 memcpy(m, cm, sizeof(*cm));
500 if (match->compat_from_user)
501 match->compat_from_user(m->data, cm->data);
503 memcpy(m->data, cm->data, msize - sizeof(*cm));
504 pad = XT_ALIGN(match->matchsize) - match->matchsize;
506 memset(m->data + match->matchsize, 0, pad);
509 m->u.user.match_size = msize;
515 EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
517 int xt_compat_match_to_user(const struct xt_entry_match *m,
518 void __user **dstptr, unsigned int *size)
520 const struct xt_match *match = m->u.kernel.match;
521 struct compat_xt_entry_match __user *cm = *dstptr;
522 int off = xt_compat_match_offset(match);
523 u_int16_t msize = m->u.user.match_size - off;
525 if (copy_to_user(cm, m, sizeof(*cm)) ||
526 put_user(msize, &cm->u.user.match_size) ||
527 copy_to_user(cm->u.user.name, m->u.kernel.match->name,
528 strlen(m->u.kernel.match->name) + 1))
531 if (match->compat_to_user) {
532 if (match->compat_to_user((void __user *)cm->data, m->data))
535 if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
543 EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
544 #endif /* CONFIG_COMPAT */
546 int xt_check_target(struct xt_tgchk_param *par,
547 unsigned int size, u_int8_t proto, bool inv_proto)
551 if (XT_ALIGN(par->target->targetsize) != size) {
552 pr_err("%s_tables: %s.%u target: invalid size "
553 "%u (kernel) != (user) %u\n",
554 xt_prefix[par->family], par->target->name,
555 par->target->revision,
556 XT_ALIGN(par->target->targetsize), size);
559 if (par->target->table != NULL &&
560 strcmp(par->target->table, par->table) != 0) {
561 pr_err("%s_tables: %s target: only valid in %s table, not %s\n",
562 xt_prefix[par->family], par->target->name,
563 par->target->table, par->table);
566 if (par->target->hooks && (par->hook_mask & ~par->target->hooks) != 0) {
567 char used[64], allow[64];
569 pr_err("%s_tables: %s target: used from hooks %s, but only "
571 xt_prefix[par->family], par->target->name,
572 textify_hooks(used, sizeof(used), par->hook_mask,
574 textify_hooks(allow, sizeof(allow), par->target->hooks,
578 if (par->target->proto && (par->target->proto != proto || inv_proto)) {
579 pr_err("%s_tables: %s target: only valid for protocol %u\n",
580 xt_prefix[par->family], par->target->name,
584 if (par->target->checkentry != NULL) {
585 ret = par->target->checkentry(par);
589 /* Flag up potential errors. */
594 EXPORT_SYMBOL_GPL(xt_check_target);
597 int xt_compat_target_offset(const struct xt_target *target)
599 u_int16_t csize = target->compatsize ? : target->targetsize;
600 return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
602 EXPORT_SYMBOL_GPL(xt_compat_target_offset);
604 void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
607 const struct xt_target *target = t->u.kernel.target;
608 struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
609 int pad, off = xt_compat_target_offset(target);
610 u_int16_t tsize = ct->u.user.target_size;
613 memcpy(t, ct, sizeof(*ct));
614 if (target->compat_from_user)
615 target->compat_from_user(t->data, ct->data);
617 memcpy(t->data, ct->data, tsize - sizeof(*ct));
618 pad = XT_ALIGN(target->targetsize) - target->targetsize;
620 memset(t->data + target->targetsize, 0, pad);
623 t->u.user.target_size = tsize;
628 EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
630 int xt_compat_target_to_user(const struct xt_entry_target *t,
631 void __user **dstptr, unsigned int *size)
633 const struct xt_target *target = t->u.kernel.target;
634 struct compat_xt_entry_target __user *ct = *dstptr;
635 int off = xt_compat_target_offset(target);
636 u_int16_t tsize = t->u.user.target_size - off;
638 if (copy_to_user(ct, t, sizeof(*ct)) ||
639 put_user(tsize, &ct->u.user.target_size) ||
640 copy_to_user(ct->u.user.name, t->u.kernel.target->name,
641 strlen(t->u.kernel.target->name) + 1))
644 if (target->compat_to_user) {
645 if (target->compat_to_user((void __user *)ct->data, t->data))
648 if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
656 EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
659 struct xt_table_info *xt_alloc_table_info(unsigned int size)
661 struct xt_table_info *newinfo;
663 /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
664 if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages)
667 newinfo = kzalloc(XT_TABLE_INFO_SZ, GFP_KERNEL);
671 newinfo->size = size;
673 if (size <= PAGE_SIZE)
674 newinfo->entries = kmalloc(size, GFP_KERNEL);
676 newinfo->entries = vmalloc(size);
678 if (newinfo->entries == NULL) {
679 xt_free_table_info(newinfo);
685 EXPORT_SYMBOL(xt_alloc_table_info);
687 void xt_free_table_info(struct xt_table_info *info)
691 kvfree(info->entries);
693 if (info->jumpstack != NULL) {
694 for_each_possible_cpu(cpu)
695 kvfree(info->jumpstack[cpu]);
696 kvfree(info->jumpstack);
699 free_percpu(info->stackptr);
703 EXPORT_SYMBOL(xt_free_table_info);
705 /* Find table by name, grabs mutex & ref. Returns ERR_PTR() on error. */
706 struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
711 mutex_lock(&xt[af].mutex);
712 list_for_each_entry(t, &net->xt.tables[af], list)
713 if (strcmp(t->name, name) == 0 && try_module_get(t->me))
715 mutex_unlock(&xt[af].mutex);
718 EXPORT_SYMBOL_GPL(xt_find_table_lock);
720 void xt_table_unlock(struct xt_table *table)
722 mutex_unlock(&xt[table->af].mutex);
724 EXPORT_SYMBOL_GPL(xt_table_unlock);
727 void xt_compat_lock(u_int8_t af)
729 mutex_lock(&xt[af].compat_mutex);
731 EXPORT_SYMBOL_GPL(xt_compat_lock);
733 void xt_compat_unlock(u_int8_t af)
735 mutex_unlock(&xt[af].compat_mutex);
737 EXPORT_SYMBOL_GPL(xt_compat_unlock);
740 DEFINE_PER_CPU(seqcount_t, xt_recseq);
741 EXPORT_PER_CPU_SYMBOL_GPL(xt_recseq);
743 static int xt_jumpstack_alloc(struct xt_table_info *i)
748 i->stackptr = alloc_percpu(unsigned int);
749 if (i->stackptr == NULL)
752 size = sizeof(void **) * nr_cpu_ids;
753 if (size > PAGE_SIZE)
754 i->jumpstack = vzalloc(size);
756 i->jumpstack = kzalloc(size, GFP_KERNEL);
757 if (i->jumpstack == NULL)
760 i->stacksize *= xt_jumpstack_multiplier;
761 size = sizeof(void *) * i->stacksize;
762 for_each_possible_cpu(cpu) {
763 if (size > PAGE_SIZE)
764 i->jumpstack[cpu] = vmalloc_node(size,
767 i->jumpstack[cpu] = kmalloc_node(size,
768 GFP_KERNEL, cpu_to_node(cpu));
769 if (i->jumpstack[cpu] == NULL)
771 * Freeing will be done later on by the callers. The
772 * chain is: xt_replace_table -> __do_replace ->
773 * do_replace -> xt_free_table_info.
781 struct xt_table_info *
782 xt_replace_table(struct xt_table *table,
783 unsigned int num_counters,
784 struct xt_table_info *newinfo,
787 struct xt_table_info *private;
790 ret = xt_jumpstack_alloc(newinfo);
796 /* Do the substitution. */
798 private = table->private;
800 /* Check inside lock: is the old number correct? */
801 if (num_counters != private->number) {
802 pr_debug("num_counters != table->private->number (%u/%u)\n",
803 num_counters, private->number);
809 newinfo->initial_entries = private->initial_entries;
811 * Ensure contents of newinfo are visible before assigning to
815 table->private = newinfo;
818 * Even though table entries have now been swapped, other CPU's
819 * may still be using the old entries. This is okay, because
820 * resynchronization happens because of the locking done
821 * during the get_counters() routine.
827 struct audit_buffer *ab;
829 ab = audit_log_start(current->audit_context, GFP_KERNEL,
830 AUDIT_NETFILTER_CFG);
832 audit_log_format(ab, "table=%s family=%u entries=%u",
833 table->name, table->af,
842 EXPORT_SYMBOL_GPL(xt_replace_table);
844 struct xt_table *xt_register_table(struct net *net,
845 const struct xt_table *input_table,
846 struct xt_table_info *bootstrap,
847 struct xt_table_info *newinfo)
850 struct xt_table_info *private;
851 struct xt_table *t, *table;
853 /* Don't add one object to multiple lists. */
854 table = kmemdup(input_table, sizeof(struct xt_table), GFP_KERNEL);
860 mutex_lock(&xt[table->af].mutex);
861 /* Don't autoload: we'd eat our tail... */
862 list_for_each_entry(t, &net->xt.tables[table->af], list) {
863 if (strcmp(t->name, table->name) == 0) {
869 /* Simplifies replace_table code. */
870 table->private = bootstrap;
872 if (!xt_replace_table(table, 0, newinfo, &ret))
875 private = table->private;
876 pr_debug("table->private->number = %u\n", private->number);
878 /* save number of initial entries */
879 private->initial_entries = private->number;
881 list_add(&table->list, &net->xt.tables[table->af]);
882 mutex_unlock(&xt[table->af].mutex);
886 mutex_unlock(&xt[table->af].mutex);
891 EXPORT_SYMBOL_GPL(xt_register_table);
893 void *xt_unregister_table(struct xt_table *table)
895 struct xt_table_info *private;
897 mutex_lock(&xt[table->af].mutex);
898 private = table->private;
899 list_del(&table->list);
900 mutex_unlock(&xt[table->af].mutex);
905 EXPORT_SYMBOL_GPL(xt_unregister_table);
907 #ifdef CONFIG_PROC_FS
908 struct xt_names_priv {
909 struct seq_net_private p;
912 static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)
914 struct xt_names_priv *priv = seq->private;
915 struct net *net = seq_file_net(seq);
916 u_int8_t af = priv->af;
918 mutex_lock(&xt[af].mutex);
919 return seq_list_start(&net->xt.tables[af], *pos);
922 static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
924 struct xt_names_priv *priv = seq->private;
925 struct net *net = seq_file_net(seq);
926 u_int8_t af = priv->af;
928 return seq_list_next(v, &net->xt.tables[af], pos);
931 static void xt_table_seq_stop(struct seq_file *seq, void *v)
933 struct xt_names_priv *priv = seq->private;
934 u_int8_t af = priv->af;
936 mutex_unlock(&xt[af].mutex);
939 static int xt_table_seq_show(struct seq_file *seq, void *v)
941 struct xt_table *table = list_entry(v, struct xt_table, list);
944 seq_printf(seq, "%s\n", table->name);
948 static const struct seq_operations xt_table_seq_ops = {
949 .start = xt_table_seq_start,
950 .next = xt_table_seq_next,
951 .stop = xt_table_seq_stop,
952 .show = xt_table_seq_show,
955 static int xt_table_open(struct inode *inode, struct file *file)
958 struct xt_names_priv *priv;
960 ret = seq_open_net(inode, file, &xt_table_seq_ops,
961 sizeof(struct xt_names_priv));
963 priv = ((struct seq_file *)file->private_data)->private;
964 priv->af = (unsigned long)PDE_DATA(inode);
969 static const struct file_operations xt_table_ops = {
970 .owner = THIS_MODULE,
971 .open = xt_table_open,
974 .release = seq_release_net,
978 * Traverse state for ip{,6}_{tables,matches} for helping crossing
979 * the multi-AF mutexes.
981 struct nf_mttg_trav {
982 struct list_head *head, *curr;
983 uint8_t class, nfproto;
988 MTTG_TRAV_NFP_UNSPEC,
993 static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos,
996 static const uint8_t next_class[] = {
997 [MTTG_TRAV_NFP_UNSPEC] = MTTG_TRAV_NFP_SPEC,
998 [MTTG_TRAV_NFP_SPEC] = MTTG_TRAV_DONE,
1000 struct nf_mttg_trav *trav = seq->private;
1002 switch (trav->class) {
1003 case MTTG_TRAV_INIT:
1004 trav->class = MTTG_TRAV_NFP_UNSPEC;
1005 mutex_lock(&xt[NFPROTO_UNSPEC].mutex);
1006 trav->head = trav->curr = is_target ?
1007 &xt[NFPROTO_UNSPEC].target : &xt[NFPROTO_UNSPEC].match;
1009 case MTTG_TRAV_NFP_UNSPEC:
1010 trav->curr = trav->curr->next;
1011 if (trav->curr != trav->head)
1013 mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
1014 mutex_lock(&xt[trav->nfproto].mutex);
1015 trav->head = trav->curr = is_target ?
1016 &xt[trav->nfproto].target : &xt[trav->nfproto].match;
1017 trav->class = next_class[trav->class];
1019 case MTTG_TRAV_NFP_SPEC:
1020 trav->curr = trav->curr->next;
1021 if (trav->curr != trav->head)
1023 /* fallthru, _stop will unlock */
1033 static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
1036 struct nf_mttg_trav *trav = seq->private;
1039 trav->class = MTTG_TRAV_INIT;
1040 for (j = 0; j < *pos; ++j)
1041 if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
1046 static void xt_mttg_seq_stop(struct seq_file *seq, void *v)
1048 struct nf_mttg_trav *trav = seq->private;
1050 switch (trav->class) {
1051 case MTTG_TRAV_NFP_UNSPEC:
1052 mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
1054 case MTTG_TRAV_NFP_SPEC:
1055 mutex_unlock(&xt[trav->nfproto].mutex);
1060 static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
1062 return xt_mttg_seq_start(seq, pos, false);
1065 static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
1067 return xt_mttg_seq_next(seq, v, ppos, false);
1070 static int xt_match_seq_show(struct seq_file *seq, void *v)
1072 const struct nf_mttg_trav *trav = seq->private;
1073 const struct xt_match *match;
1075 switch (trav->class) {
1076 case MTTG_TRAV_NFP_UNSPEC:
1077 case MTTG_TRAV_NFP_SPEC:
1078 if (trav->curr == trav->head)
1080 match = list_entry(trav->curr, struct xt_match, list);
1082 seq_printf(seq, "%s\n", match->name);
1087 static const struct seq_operations xt_match_seq_ops = {
1088 .start = xt_match_seq_start,
1089 .next = xt_match_seq_next,
1090 .stop = xt_mttg_seq_stop,
1091 .show = xt_match_seq_show,
1094 static int xt_match_open(struct inode *inode, struct file *file)
1096 struct nf_mttg_trav *trav;
1097 trav = __seq_open_private(file, &xt_match_seq_ops, sizeof(*trav));
1101 trav->nfproto = (unsigned long)PDE_DATA(inode);
1105 static const struct file_operations xt_match_ops = {
1106 .owner = THIS_MODULE,
1107 .open = xt_match_open,
1109 .llseek = seq_lseek,
1110 .release = seq_release_private,
1113 static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)
1115 return xt_mttg_seq_start(seq, pos, true);
1118 static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
1120 return xt_mttg_seq_next(seq, v, ppos, true);
1123 static int xt_target_seq_show(struct seq_file *seq, void *v)
1125 const struct nf_mttg_trav *trav = seq->private;
1126 const struct xt_target *target;
1128 switch (trav->class) {
1129 case MTTG_TRAV_NFP_UNSPEC:
1130 case MTTG_TRAV_NFP_SPEC:
1131 if (trav->curr == trav->head)
1133 target = list_entry(trav->curr, struct xt_target, list);
1135 seq_printf(seq, "%s\n", target->name);
1140 static const struct seq_operations xt_target_seq_ops = {
1141 .start = xt_target_seq_start,
1142 .next = xt_target_seq_next,
1143 .stop = xt_mttg_seq_stop,
1144 .show = xt_target_seq_show,
1147 static int xt_target_open(struct inode *inode, struct file *file)
1149 struct nf_mttg_trav *trav;
1150 trav = __seq_open_private(file, &xt_target_seq_ops, sizeof(*trav));
1154 trav->nfproto = (unsigned long)PDE_DATA(inode);
1158 static const struct file_operations xt_target_ops = {
1159 .owner = THIS_MODULE,
1160 .open = xt_target_open,
1162 .llseek = seq_lseek,
1163 .release = seq_release_private,
1166 #define FORMAT_TABLES "_tables_names"
1167 #define FORMAT_MATCHES "_tables_matches"
1168 #define FORMAT_TARGETS "_tables_targets"
1170 #endif /* CONFIG_PROC_FS */
1173 * xt_hook_link - set up hooks for a new table
1174 * @table: table with metadata needed to set up hooks
1175 * @fn: Hook function
1177 * This function will take care of creating and registering the necessary
1178 * Netfilter hooks for XT tables.
1180 struct nf_hook_ops *xt_hook_link(const struct xt_table *table, nf_hookfn *fn)
1182 unsigned int hook_mask = table->valid_hooks;
1183 uint8_t i, num_hooks = hweight32(hook_mask);
1185 struct nf_hook_ops *ops;
1188 ops = kmalloc(sizeof(*ops) * num_hooks, GFP_KERNEL);
1190 return ERR_PTR(-ENOMEM);
1192 for (i = 0, hooknum = 0; i < num_hooks && hook_mask != 0;
1193 hook_mask >>= 1, ++hooknum) {
1194 if (!(hook_mask & 1))
1197 ops[i].owner = table->me;
1198 ops[i].pf = table->af;
1199 ops[i].hooknum = hooknum;
1200 ops[i].priority = table->priority;
1204 ret = nf_register_hooks(ops, num_hooks);
1207 return ERR_PTR(ret);
1212 EXPORT_SYMBOL_GPL(xt_hook_link);
1215 * xt_hook_unlink - remove hooks for a table
1216 * @ops: nf_hook_ops array as returned by nf_hook_link
1217 * @hook_mask: the very same mask that was passed to nf_hook_link
1219 void xt_hook_unlink(const struct xt_table *table, struct nf_hook_ops *ops)
1221 nf_unregister_hooks(ops, hweight32(table->valid_hooks));
1224 EXPORT_SYMBOL_GPL(xt_hook_unlink);
1226 int xt_proto_init(struct net *net, u_int8_t af)
1228 #ifdef CONFIG_PROC_FS
1229 char buf[XT_FUNCTION_MAXNAMELEN];
1230 struct proc_dir_entry *proc;
1233 if (af >= ARRAY_SIZE(xt_prefix))
1237 #ifdef CONFIG_PROC_FS
1238 strlcpy(buf, xt_prefix[af], sizeof(buf));
1239 strlcat(buf, FORMAT_TABLES, sizeof(buf));
1240 proc = proc_create_data(buf, 0440, net->proc_net, &xt_table_ops,
1241 (void *)(unsigned long)af);
1245 strlcpy(buf, xt_prefix[af], sizeof(buf));
1246 strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1247 proc = proc_create_data(buf, 0440, net->proc_net, &xt_match_ops,
1248 (void *)(unsigned long)af);
1250 goto out_remove_tables;
1252 strlcpy(buf, xt_prefix[af], sizeof(buf));
1253 strlcat(buf, FORMAT_TARGETS, sizeof(buf));
1254 proc = proc_create_data(buf, 0440, net->proc_net, &xt_target_ops,
1255 (void *)(unsigned long)af);
1257 goto out_remove_matches;
1262 #ifdef CONFIG_PROC_FS
1264 strlcpy(buf, xt_prefix[af], sizeof(buf));
1265 strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1266 remove_proc_entry(buf, net->proc_net);
1269 strlcpy(buf, xt_prefix[af], sizeof(buf));
1270 strlcat(buf, FORMAT_TABLES, sizeof(buf));
1271 remove_proc_entry(buf, net->proc_net);
1276 EXPORT_SYMBOL_GPL(xt_proto_init);
1278 void xt_proto_fini(struct net *net, u_int8_t af)
1280 #ifdef CONFIG_PROC_FS
1281 char buf[XT_FUNCTION_MAXNAMELEN];
1283 strlcpy(buf, xt_prefix[af], sizeof(buf));
1284 strlcat(buf, FORMAT_TABLES, sizeof(buf));
1285 remove_proc_entry(buf, net->proc_net);
1287 strlcpy(buf, xt_prefix[af], sizeof(buf));
1288 strlcat(buf, FORMAT_TARGETS, sizeof(buf));
1289 remove_proc_entry(buf, net->proc_net);
1291 strlcpy(buf, xt_prefix[af], sizeof(buf));
1292 strlcat(buf, FORMAT_MATCHES, sizeof(buf));
1293 remove_proc_entry(buf, net->proc_net);
1294 #endif /*CONFIG_PROC_FS*/
1296 EXPORT_SYMBOL_GPL(xt_proto_fini);
1298 static int __net_init xt_net_init(struct net *net)
1302 for (i = 0; i < NFPROTO_NUMPROTO; i++)
1303 INIT_LIST_HEAD(&net->xt.tables[i]);
1307 static struct pernet_operations xt_net_ops = {
1308 .init = xt_net_init,
1311 static int __init xt_init(void)
1316 for_each_possible_cpu(i) {
1317 seqcount_init(&per_cpu(xt_recseq, i));
1320 xt = kmalloc(sizeof(struct xt_af) * NFPROTO_NUMPROTO, GFP_KERNEL);
1324 for (i = 0; i < NFPROTO_NUMPROTO; i++) {
1325 mutex_init(&xt[i].mutex);
1326 #ifdef CONFIG_COMPAT
1327 mutex_init(&xt[i].compat_mutex);
1328 xt[i].compat_tab = NULL;
1330 INIT_LIST_HEAD(&xt[i].target);
1331 INIT_LIST_HEAD(&xt[i].match);
1333 rv = register_pernet_subsys(&xt_net_ops);
1339 static void __exit xt_fini(void)
1341 unregister_pernet_subsys(&xt_net_ops);
1345 module_init(xt_init);
1346 module_exit(xt_fini);