2 * x_tables core - Backend for {ip,ip6,arp}_tables
4 * Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
6 * Based on existing ip_tables code which is
7 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
8 * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
16 #include <linux/kernel.h>
17 #include <linux/socket.h>
18 #include <linux/net.h>
19 #include <linux/proc_fs.h>
20 #include <linux/seq_file.h>
21 #include <linux/string.h>
22 #include <linux/vmalloc.h>
23 #include <linux/mutex.h>
25 #include <net/net_namespace.h>
27 #include <linux/netfilter/x_tables.h>
28 #include <linux/netfilter_arp.h>
31 MODULE_LICENSE("GPL");
32 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
33 MODULE_DESCRIPTION("[ip,ip6,arp]_tables backend module");
35 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
39 struct list_head match;
40 struct list_head target;
41 struct list_head tables;
42 struct mutex compat_mutex;
45 static struct xt_af *xt;
47 #ifdef DEBUG_IP_FIREWALL_USER
48 #define duprintf(format, args...) printk(format , ## args)
50 #define duprintf(format, args...)
59 static const char *xt_prefix[NPROTO] = {
65 /* Registration hooks for targets. */
67 xt_register_target(struct xt_target *target)
69 int ret, af = target->family;
71 ret = mutex_lock_interruptible(&xt[af].mutex);
74 list_add(&target->list, &xt[af].target);
75 mutex_unlock(&xt[af].mutex);
78 EXPORT_SYMBOL(xt_register_target);
81 xt_unregister_target(struct xt_target *target)
83 int af = target->family;
85 mutex_lock(&xt[af].mutex);
86 list_del(&target->list);
87 mutex_unlock(&xt[af].mutex);
89 EXPORT_SYMBOL(xt_unregister_target);
92 xt_register_targets(struct xt_target *target, unsigned int n)
97 for (i = 0; i < n; i++) {
98 err = xt_register_target(&target[i]);
106 xt_unregister_targets(target, i);
109 EXPORT_SYMBOL(xt_register_targets);
112 xt_unregister_targets(struct xt_target *target, unsigned int n)
116 for (i = 0; i < n; i++)
117 xt_unregister_target(&target[i]);
119 EXPORT_SYMBOL(xt_unregister_targets);
122 xt_register_match(struct xt_match *match)
124 int ret, af = match->family;
126 ret = mutex_lock_interruptible(&xt[af].mutex);
130 list_add(&match->list, &xt[af].match);
131 mutex_unlock(&xt[af].mutex);
135 EXPORT_SYMBOL(xt_register_match);
138 xt_unregister_match(struct xt_match *match)
140 int af = match->family;
142 mutex_lock(&xt[af].mutex);
143 list_del(&match->list);
144 mutex_unlock(&xt[af].mutex);
146 EXPORT_SYMBOL(xt_unregister_match);
149 xt_register_matches(struct xt_match *match, unsigned int n)
154 for (i = 0; i < n; i++) {
155 err = xt_register_match(&match[i]);
163 xt_unregister_matches(match, i);
166 EXPORT_SYMBOL(xt_register_matches);
169 xt_unregister_matches(struct xt_match *match, unsigned int n)
173 for (i = 0; i < n; i++)
174 xt_unregister_match(&match[i]);
176 EXPORT_SYMBOL(xt_unregister_matches);
180 * These are weird, but module loading must not be done with mutex
181 * held (since they will register), and we have to have a single
182 * function to use try_then_request_module().
185 /* Find match, grabs ref. Returns ERR_PTR() on error. */
186 struct xt_match *xt_find_match(int af, const char *name, u8 revision)
191 if (mutex_lock_interruptible(&xt[af].mutex) != 0)
192 return ERR_PTR(-EINTR);
194 list_for_each_entry(m, &xt[af].match, list) {
195 if (strcmp(m->name, name) == 0) {
196 if (m->revision == revision) {
197 if (try_module_get(m->me)) {
198 mutex_unlock(&xt[af].mutex);
202 err = -EPROTOTYPE; /* Found something. */
205 mutex_unlock(&xt[af].mutex);
208 EXPORT_SYMBOL(xt_find_match);
210 /* Find target, grabs ref. Returns ERR_PTR() on error. */
211 struct xt_target *xt_find_target(int af, const char *name, u8 revision)
216 if (mutex_lock_interruptible(&xt[af].mutex) != 0)
217 return ERR_PTR(-EINTR);
219 list_for_each_entry(t, &xt[af].target, list) {
220 if (strcmp(t->name, name) == 0) {
221 if (t->revision == revision) {
222 if (try_module_get(t->me)) {
223 mutex_unlock(&xt[af].mutex);
227 err = -EPROTOTYPE; /* Found something. */
230 mutex_unlock(&xt[af].mutex);
233 EXPORT_SYMBOL(xt_find_target);
235 struct xt_target *xt_request_find_target(int af, const char *name, u8 revision)
237 struct xt_target *target;
239 target = try_then_request_module(xt_find_target(af, name, revision),
240 "%st_%s", xt_prefix[af], name);
241 if (IS_ERR(target) || !target)
245 EXPORT_SYMBOL_GPL(xt_request_find_target);
247 static int match_revfn(int af, const char *name, u8 revision, int *bestp)
252 list_for_each_entry(m, &xt[af].match, list) {
253 if (strcmp(m->name, name) == 0) {
254 if (m->revision > *bestp)
255 *bestp = m->revision;
256 if (m->revision == revision)
263 static int target_revfn(int af, const char *name, u8 revision, int *bestp)
268 list_for_each_entry(t, &xt[af].target, list) {
269 if (strcmp(t->name, name) == 0) {
270 if (t->revision > *bestp)
271 *bestp = t->revision;
272 if (t->revision == revision)
279 /* Returns true or false (if no such extension at all) */
280 int xt_find_revision(int af, const char *name, u8 revision, int target,
283 int have_rev, best = -1;
285 if (mutex_lock_interruptible(&xt[af].mutex) != 0) {
290 have_rev = target_revfn(af, name, revision, &best);
292 have_rev = match_revfn(af, name, revision, &best);
293 mutex_unlock(&xt[af].mutex);
295 /* Nothing at all? Return 0 to try loading module. */
303 *err = -EPROTONOSUPPORT;
306 EXPORT_SYMBOL_GPL(xt_find_revision);
308 int xt_check_match(const struct xt_match *match, unsigned short family,
309 unsigned int size, const char *table, unsigned int hook_mask,
310 unsigned short proto, int inv_proto)
312 if (XT_ALIGN(match->matchsize) != size) {
313 printk("%s_tables: %s match: invalid size %Zu != %u\n",
314 xt_prefix[family], match->name,
315 XT_ALIGN(match->matchsize), size);
318 if (match->table && strcmp(match->table, table)) {
319 printk("%s_tables: %s match: only valid in %s table, not %s\n",
320 xt_prefix[family], match->name, match->table, table);
323 if (match->hooks && (hook_mask & ~match->hooks) != 0) {
324 printk("%s_tables: %s match: bad hook_mask %u/%u\n",
325 xt_prefix[family], match->name, hook_mask, match->hooks);
328 if (match->proto && (match->proto != proto || inv_proto)) {
329 printk("%s_tables: %s match: only valid for protocol %u\n",
330 xt_prefix[family], match->name, match->proto);
335 EXPORT_SYMBOL_GPL(xt_check_match);
338 int xt_compat_match_offset(struct xt_match *match)
340 u_int16_t csize = match->compatsize ? : match->matchsize;
341 return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
343 EXPORT_SYMBOL_GPL(xt_compat_match_offset);
345 int xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
348 struct xt_match *match = m->u.kernel.match;
349 struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
350 int pad, off = xt_compat_match_offset(match);
351 u_int16_t msize = cm->u.user.match_size;
354 memcpy(m, cm, sizeof(*cm));
355 if (match->compat_from_user)
356 match->compat_from_user(m->data, cm->data);
358 memcpy(m->data, cm->data, msize - sizeof(*cm));
359 pad = XT_ALIGN(match->matchsize) - match->matchsize;
361 memset(m->data + match->matchsize, 0, pad);
364 m->u.user.match_size = msize;
370 EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
372 int xt_compat_match_to_user(struct xt_entry_match *m, void __user **dstptr,
375 struct xt_match *match = m->u.kernel.match;
376 struct compat_xt_entry_match __user *cm = *dstptr;
377 int off = xt_compat_match_offset(match);
378 u_int16_t msize = m->u.user.match_size - off;
380 if (copy_to_user(cm, m, sizeof(*cm)) ||
381 put_user(msize, &cm->u.user.match_size) ||
382 copy_to_user(cm->u.user.name, m->u.kernel.match->name,
383 strlen(m->u.kernel.match->name) + 1))
386 if (match->compat_to_user) {
387 if (match->compat_to_user((void __user *)cm->data, m->data))
390 if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
398 EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
399 #endif /* CONFIG_COMPAT */
401 int xt_check_target(const struct xt_target *target, unsigned short family,
402 unsigned int size, const char *table, unsigned int hook_mask,
403 unsigned short proto, int inv_proto)
405 if (XT_ALIGN(target->targetsize) != size) {
406 printk("%s_tables: %s target: invalid size %Zu != %u\n",
407 xt_prefix[family], target->name,
408 XT_ALIGN(target->targetsize), size);
411 if (target->table && strcmp(target->table, table)) {
412 printk("%s_tables: %s target: only valid in %s table, not %s\n",
413 xt_prefix[family], target->name, target->table, table);
416 if (target->hooks && (hook_mask & ~target->hooks) != 0) {
417 printk("%s_tables: %s target: bad hook_mask %u/%u\n",
418 xt_prefix[family], target->name, hook_mask,
422 if (target->proto && (target->proto != proto || inv_proto)) {
423 printk("%s_tables: %s target: only valid for protocol %u\n",
424 xt_prefix[family], target->name, target->proto);
429 EXPORT_SYMBOL_GPL(xt_check_target);
432 int xt_compat_target_offset(struct xt_target *target)
434 u_int16_t csize = target->compatsize ? : target->targetsize;
435 return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
437 EXPORT_SYMBOL_GPL(xt_compat_target_offset);
439 void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
442 struct xt_target *target = t->u.kernel.target;
443 struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
444 int pad, off = xt_compat_target_offset(target);
445 u_int16_t tsize = ct->u.user.target_size;
448 memcpy(t, ct, sizeof(*ct));
449 if (target->compat_from_user)
450 target->compat_from_user(t->data, ct->data);
452 memcpy(t->data, ct->data, tsize - sizeof(*ct));
453 pad = XT_ALIGN(target->targetsize) - target->targetsize;
455 memset(t->data + target->targetsize, 0, pad);
458 t->u.user.target_size = tsize;
463 EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
465 int xt_compat_target_to_user(struct xt_entry_target *t, void __user **dstptr,
468 struct xt_target *target = t->u.kernel.target;
469 struct compat_xt_entry_target __user *ct = *dstptr;
470 int off = xt_compat_target_offset(target);
471 u_int16_t tsize = t->u.user.target_size - off;
473 if (copy_to_user(ct, t, sizeof(*ct)) ||
474 put_user(tsize, &ct->u.user.target_size) ||
475 copy_to_user(ct->u.user.name, t->u.kernel.target->name,
476 strlen(t->u.kernel.target->name) + 1))
479 if (target->compat_to_user) {
480 if (target->compat_to_user((void __user *)ct->data, t->data))
483 if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
491 EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
494 struct xt_table_info *xt_alloc_table_info(unsigned int size)
496 struct xt_table_info *newinfo;
499 /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
500 if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > num_physpages)
503 newinfo = kzalloc(XT_TABLE_INFO_SZ, GFP_KERNEL);
507 newinfo->size = size;
509 for_each_possible_cpu(cpu) {
510 if (size <= PAGE_SIZE)
511 newinfo->entries[cpu] = kmalloc_node(size,
515 newinfo->entries[cpu] = vmalloc_node(size,
518 if (newinfo->entries[cpu] == NULL) {
519 xt_free_table_info(newinfo);
526 EXPORT_SYMBOL(xt_alloc_table_info);
528 void xt_free_table_info(struct xt_table_info *info)
532 for_each_possible_cpu(cpu) {
533 if (info->size <= PAGE_SIZE)
534 kfree(info->entries[cpu]);
536 vfree(info->entries[cpu]);
540 EXPORT_SYMBOL(xt_free_table_info);
542 /* Find table by name, grabs mutex & ref. Returns ERR_PTR() on error. */
543 struct xt_table *xt_find_table_lock(int af, const char *name)
547 if (mutex_lock_interruptible(&xt[af].mutex) != 0)
548 return ERR_PTR(-EINTR);
550 list_for_each_entry(t, &xt[af].tables, list)
551 if (strcmp(t->name, name) == 0 && try_module_get(t->me))
553 mutex_unlock(&xt[af].mutex);
556 EXPORT_SYMBOL_GPL(xt_find_table_lock);
558 void xt_table_unlock(struct xt_table *table)
560 mutex_unlock(&xt[table->af].mutex);
562 EXPORT_SYMBOL_GPL(xt_table_unlock);
565 void xt_compat_lock(int af)
567 mutex_lock(&xt[af].compat_mutex);
569 EXPORT_SYMBOL_GPL(xt_compat_lock);
571 void xt_compat_unlock(int af)
573 mutex_unlock(&xt[af].compat_mutex);
575 EXPORT_SYMBOL_GPL(xt_compat_unlock);
578 struct xt_table_info *
579 xt_replace_table(struct xt_table *table,
580 unsigned int num_counters,
581 struct xt_table_info *newinfo,
584 struct xt_table_info *oldinfo, *private;
586 /* Do the substitution. */
587 write_lock_bh(&table->lock);
588 private = table->private;
589 /* Check inside lock: is the old number correct? */
590 if (num_counters != private->number) {
591 duprintf("num_counters != table->private->number (%u/%u)\n",
592 num_counters, private->number);
593 write_unlock_bh(&table->lock);
598 table->private = newinfo;
599 newinfo->initial_entries = oldinfo->initial_entries;
600 write_unlock_bh(&table->lock);
604 EXPORT_SYMBOL_GPL(xt_replace_table);
606 int xt_register_table(struct xt_table *table,
607 struct xt_table_info *bootstrap,
608 struct xt_table_info *newinfo)
611 struct xt_table_info *private;
614 ret = mutex_lock_interruptible(&xt[table->af].mutex);
618 /* Don't autoload: we'd eat our tail... */
619 list_for_each_entry(t, &xt[table->af].tables, list) {
620 if (strcmp(t->name, table->name) == 0) {
626 /* Simplifies replace_table code. */
627 table->private = bootstrap;
628 rwlock_init(&table->lock);
629 if (!xt_replace_table(table, 0, newinfo, &ret))
632 private = table->private;
633 duprintf("table->private->number = %u\n", private->number);
635 /* save number of initial entries */
636 private->initial_entries = private->number;
638 list_add(&table->list, &xt[table->af].tables);
642 mutex_unlock(&xt[table->af].mutex);
645 EXPORT_SYMBOL_GPL(xt_register_table);
647 void *xt_unregister_table(struct xt_table *table)
649 struct xt_table_info *private;
651 mutex_lock(&xt[table->af].mutex);
652 private = table->private;
653 list_del(&table->list);
654 mutex_unlock(&xt[table->af].mutex);
658 EXPORT_SYMBOL_GPL(xt_unregister_table);
660 #ifdef CONFIG_PROC_FS
661 static struct list_head *xt_get_idx(struct list_head *list, struct seq_file *seq, loff_t pos)
663 struct list_head *head = list->next;
665 if (!head || list_empty(list))
668 while (pos && (head = head->next)) {
673 return pos ? NULL : head;
676 static struct list_head *type2list(u_int16_t af, u_int16_t type)
678 struct list_head *list;
682 list = &xt[af].target;
685 list = &xt[af].match;
688 list = &xt[af].tables;
698 static void *xt_tgt_seq_start(struct seq_file *seq, loff_t *pos)
700 struct proc_dir_entry *pde = (struct proc_dir_entry *) seq->private;
701 u_int16_t af = (unsigned long)pde->data & 0xffff;
702 u_int16_t type = (unsigned long)pde->data >> 16;
703 struct list_head *list;
708 list = type2list(af, type);
712 if (mutex_lock_interruptible(&xt[af].mutex) != 0)
715 return xt_get_idx(list, seq, *pos);
718 static void *xt_tgt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
720 struct proc_dir_entry *pde = seq->private;
721 u_int16_t af = (unsigned long)pde->data & 0xffff;
722 u_int16_t type = (unsigned long)pde->data >> 16;
723 struct list_head *list;
728 list = type2list(af, type);
733 return xt_get_idx(list, seq, *pos);
736 static void xt_tgt_seq_stop(struct seq_file *seq, void *v)
738 struct proc_dir_entry *pde = seq->private;
739 u_int16_t af = (unsigned long)pde->data & 0xffff;
741 mutex_unlock(&xt[af].mutex);
744 static int xt_name_seq_show(struct seq_file *seq, void *v)
746 char *name = (char *)v + sizeof(struct list_head);
749 return seq_printf(seq, "%s\n", name);
754 static const struct seq_operations xt_tgt_seq_ops = {
755 .start = xt_tgt_seq_start,
756 .next = xt_tgt_seq_next,
757 .stop = xt_tgt_seq_stop,
758 .show = xt_name_seq_show,
761 static int xt_tgt_open(struct inode *inode, struct file *file)
765 ret = seq_open(file, &xt_tgt_seq_ops);
767 struct seq_file *seq = file->private_data;
768 struct proc_dir_entry *pde = PDE(inode);
776 static const struct file_operations xt_file_ops = {
777 .owner = THIS_MODULE,
781 .release = seq_release,
784 #define FORMAT_TABLES "_tables_names"
785 #define FORMAT_MATCHES "_tables_matches"
786 #define FORMAT_TARGETS "_tables_targets"
788 #endif /* CONFIG_PROC_FS */
790 int xt_proto_init(int af)
792 #ifdef CONFIG_PROC_FS
793 char buf[XT_FUNCTION_MAXNAMELEN];
794 struct proc_dir_entry *proc;
801 #ifdef CONFIG_PROC_FS
802 strlcpy(buf, xt_prefix[af], sizeof(buf));
803 strlcat(buf, FORMAT_TABLES, sizeof(buf));
804 proc = proc_net_fops_create(&init_net, buf, 0440, &xt_file_ops);
807 proc->data = (void *) ((unsigned long) af | (TABLE << 16));
810 strlcpy(buf, xt_prefix[af], sizeof(buf));
811 strlcat(buf, FORMAT_MATCHES, sizeof(buf));
812 proc = proc_net_fops_create(&init_net, buf, 0440, &xt_file_ops);
814 goto out_remove_tables;
815 proc->data = (void *) ((unsigned long) af | (MATCH << 16));
817 strlcpy(buf, xt_prefix[af], sizeof(buf));
818 strlcat(buf, FORMAT_TARGETS, sizeof(buf));
819 proc = proc_net_fops_create(&init_net, buf, 0440, &xt_file_ops);
821 goto out_remove_matches;
822 proc->data = (void *) ((unsigned long) af | (TARGET << 16));
827 #ifdef CONFIG_PROC_FS
829 strlcpy(buf, xt_prefix[af], sizeof(buf));
830 strlcat(buf, FORMAT_MATCHES, sizeof(buf));
831 proc_net_remove(&init_net, buf);
834 strlcpy(buf, xt_prefix[af], sizeof(buf));
835 strlcat(buf, FORMAT_TABLES, sizeof(buf));
836 proc_net_remove(&init_net, buf);
841 EXPORT_SYMBOL_GPL(xt_proto_init);
843 void xt_proto_fini(int af)
845 #ifdef CONFIG_PROC_FS
846 char buf[XT_FUNCTION_MAXNAMELEN];
848 strlcpy(buf, xt_prefix[af], sizeof(buf));
849 strlcat(buf, FORMAT_TABLES, sizeof(buf));
850 proc_net_remove(&init_net, buf);
852 strlcpy(buf, xt_prefix[af], sizeof(buf));
853 strlcat(buf, FORMAT_TARGETS, sizeof(buf));
854 proc_net_remove(&init_net, buf);
856 strlcpy(buf, xt_prefix[af], sizeof(buf));
857 strlcat(buf, FORMAT_MATCHES, sizeof(buf));
858 proc_net_remove(&init_net, buf);
859 #endif /*CONFIG_PROC_FS*/
861 EXPORT_SYMBOL_GPL(xt_proto_fini);
864 static int __init xt_init(void)
868 xt = kmalloc(sizeof(struct xt_af) * NPROTO, GFP_KERNEL);
872 for (i = 0; i < NPROTO; i++) {
873 mutex_init(&xt[i].mutex);
875 mutex_init(&xt[i].compat_mutex);
877 INIT_LIST_HEAD(&xt[i].target);
878 INIT_LIST_HEAD(&xt[i].match);
879 INIT_LIST_HEAD(&xt[i].tables);
884 static void __exit xt_fini(void)
889 module_init(xt_init);
890 module_exit(xt_fini);