2 * Packet matching code for ARP packets.
4 * Based heavily, if not almost entirely, upon ip_tables.c framework.
6 * Some ARP specific bits are:
8 * Copyright (C) 2002 David S. Miller (davem@redhat.com)
12 #include <linux/config.h>
13 #include <linux/kernel.h>
14 #include <linux/skbuff.h>
15 #include <linux/netdevice.h>
16 #include <linux/if_arp.h>
17 #include <linux/kmod.h>
18 #include <linux/vmalloc.h>
19 #include <linux/proc_fs.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
23 #include <asm/uaccess.h>
24 #include <asm/semaphore.h>
26 #include <linux/netfilter_arp/arp_tables.h>
28 MODULE_LICENSE("GPL");
29 MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
30 MODULE_DESCRIPTION("arptables core");
32 /*#define DEBUG_ARP_TABLES*/
33 /*#define DEBUG_ARP_TABLES_USER*/
35 #ifdef DEBUG_ARP_TABLES
36 #define dprintf(format, args...) printk(format , ## args)
38 #define dprintf(format, args...)
41 #ifdef DEBUG_ARP_TABLES_USER
42 #define duprintf(format, args...) printk(format , ## args)
44 #define duprintf(format, args...)
47 #ifdef CONFIG_NETFILTER_DEBUG
48 #define ARP_NF_ASSERT(x) \
51 printk("ARP_NF_ASSERT: %s:%s:%u\n", \
52 __FUNCTION__, __FILE__, __LINE__); \
55 #define ARP_NF_ASSERT(x)
57 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
59 static DECLARE_MUTEX(arpt_mutex);
61 #define ASSERT_READ_LOCK(x) ARP_NF_ASSERT(down_trylock(&arpt_mutex) != 0)
62 #define ASSERT_WRITE_LOCK(x) ARP_NF_ASSERT(down_trylock(&arpt_mutex) != 0)
63 #include <linux/netfilter_ipv4/lockhelp.h>
64 #include <linux/netfilter_ipv4/listhelp.h>
66 struct arpt_table_info {
69 unsigned int initial_entries;
70 unsigned int hook_entry[NF_ARP_NUMHOOKS];
71 unsigned int underflow[NF_ARP_NUMHOOKS];
72 char entries[0] __attribute__((aligned(SMP_CACHE_BYTES)));
75 static LIST_HEAD(arpt_target);
76 static LIST_HEAD(arpt_tables);
77 #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
80 #define TABLE_OFFSET(t,p) (SMP_ALIGN((t)->size)*(p))
82 #define TABLE_OFFSET(t,p) 0
85 static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
86 char *hdr_addr, int len)
90 if (len > ARPT_DEV_ADDR_LEN_MAX)
91 len = ARPT_DEV_ADDR_LEN_MAX;
94 for (i = 0; i < len; i++)
95 ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
100 /* Returns whether packet matches rule or not. */
101 static inline int arp_packet_match(const struct arphdr *arphdr,
102 struct net_device *dev,
105 const struct arpt_arp *arpinfo)
107 char *arpptr = (char *)(arphdr + 1);
108 char *src_devaddr, *tgt_devaddr;
109 u32 src_ipaddr, tgt_ipaddr;
112 #define FWINV(bool,invflg) ((bool) ^ !!(arpinfo->invflags & invflg))
114 if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
116 dprintf("ARP operation field mismatch.\n");
117 dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
118 arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
122 if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
124 dprintf("ARP hardware address format mismatch.\n");
125 dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
126 arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
130 if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
132 dprintf("ARP protocol address format mismatch.\n");
133 dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
134 arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
138 if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
140 dprintf("ARP hardware address length mismatch.\n");
141 dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
142 arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
146 src_devaddr = arpptr;
147 arpptr += dev->addr_len;
148 memcpy(&src_ipaddr, arpptr, sizeof(u32));
149 arpptr += sizeof(u32);
150 tgt_devaddr = arpptr;
151 arpptr += dev->addr_len;
152 memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
154 if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
155 ARPT_INV_SRCDEVADDR) ||
156 FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
157 ARPT_INV_TGTDEVADDR)) {
158 dprintf("Source or target device address mismatch.\n");
163 if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
165 FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
167 dprintf("Source or target IP address mismatch.\n");
169 dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
171 NIPQUAD(arpinfo->smsk.s_addr),
172 NIPQUAD(arpinfo->src.s_addr),
173 arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
174 dprintf("TGT: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
176 NIPQUAD(arpinfo->tmsk.s_addr),
177 NIPQUAD(arpinfo->tgt.s_addr),
178 arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
182 /* Look for ifname matches. */
183 for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
184 ret |= (indev[i] ^ arpinfo->iniface[i])
185 & arpinfo->iniface_mask[i];
188 if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
189 dprintf("VIA in mismatch (%s vs %s).%s\n",
190 indev, arpinfo->iniface,
191 arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
195 for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
197 memcpy(&odev, outdev + i*sizeof(unsigned long),
198 sizeof(unsigned long));
200 ^ ((const unsigned long *)arpinfo->outiface)[i])
201 & ((const unsigned long *)arpinfo->outiface_mask)[i];
204 if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
205 dprintf("VIA out mismatch (%s vs %s).%s\n",
206 outdev, arpinfo->outiface,
207 arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
214 static inline int arp_checkentry(const struct arpt_arp *arp)
216 if (arp->flags & ~ARPT_F_MASK) {
217 duprintf("Unknown flag bits set: %08X\n",
218 arp->flags & ~ARPT_F_MASK);
221 if (arp->invflags & ~ARPT_INV_MASK) {
222 duprintf("Unknown invflag bits set: %08X\n",
223 arp->invflags & ~ARPT_INV_MASK);
230 static unsigned int arpt_error(struct sk_buff **pskb,
231 unsigned int hooknum,
232 const struct net_device *in,
233 const struct net_device *out,
234 const void *targinfo,
238 printk("arp_tables: error: '%s'\n", (char *)targinfo);
243 static inline struct arpt_entry *get_entry(void *base, unsigned int offset)
245 return (struct arpt_entry *)(base + offset);
248 unsigned int arpt_do_table(struct sk_buff **pskb,
250 const struct net_device *in,
251 const struct net_device *out,
252 struct arpt_table *table,
255 static const char nulldevname[IFNAMSIZ];
256 unsigned int verdict = NF_DROP;
259 struct arpt_entry *e, *back;
260 const char *indev, *outdev;
263 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
264 if (!pskb_may_pull((*pskb), (sizeof(struct arphdr) +
265 (2 * (*pskb)->dev->addr_len) +
269 indev = in ? in->name : nulldevname;
270 outdev = out ? out->name : nulldevname;
272 read_lock_bh(&table->lock);
273 table_base = (void *)table->private->entries
274 + TABLE_OFFSET(table->private,
276 e = get_entry(table_base, table->private->hook_entry[hook]);
277 back = get_entry(table_base, table->private->underflow[hook]);
279 arp = (*pskb)->nh.arph;
281 if (arp_packet_match(arp, (*pskb)->dev, indev, outdev, &e->arp)) {
282 struct arpt_entry_target *t;
285 hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
286 (2 * (*pskb)->dev->addr_len);
287 ADD_COUNTER(e->counters, hdr_len, 1);
289 t = arpt_get_target(e);
291 /* Standard target? */
292 if (!t->u.kernel.target->target) {
295 v = ((struct arpt_standard_target *)t)->verdict;
297 /* Pop from stack? */
298 if (v != ARPT_RETURN) {
299 verdict = (unsigned)(-v) - 1;
303 back = get_entry(table_base,
308 != (void *)e + e->next_offset) {
309 /* Save old back ptr in next entry */
310 struct arpt_entry *next
311 = (void *)e + e->next_offset;
313 (void *)back - table_base;
315 /* set back pointer to next entry */
319 e = get_entry(table_base, v);
321 /* Targets which reenter must return
324 verdict = t->u.kernel.target->target(pskb,
330 /* Target might have changed stuff. */
331 arp = (*pskb)->nh.arph;
333 if (verdict == ARPT_CONTINUE)
334 e = (void *)e + e->next_offset;
340 e = (void *)e + e->next_offset;
343 read_unlock_bh(&table->lock);
351 static inline void *find_inlist_lock_noload(struct list_head *head,
354 struct semaphore *mutex)
358 *error = down_interruptible(mutex);
362 ret = list_named_find(head, name);
371 #define find_inlist_lock(h,n,p,e,m) find_inlist_lock_noload((h),(n),(e),(m))
374 find_inlist_lock(struct list_head *head,
378 struct semaphore *mutex)
382 ret = find_inlist_lock_noload(head, name, error, mutex);
384 duprintf("find_inlist: loading `%s%s'.\n", prefix, name);
385 request_module("%s%s", prefix, name);
386 ret = find_inlist_lock_noload(head, name, error, mutex);
393 static inline struct arpt_table *arpt_find_table_lock(const char *name, int *error, struct semaphore *mutex)
395 return find_inlist_lock(&arpt_tables, name, "arptable_", error, mutex);
398 struct arpt_target *arpt_find_target_lock(const char *name, int *error, struct semaphore *mutex)
400 return find_inlist_lock(&arpt_target, name, "arpt_", error, mutex);
403 /* All zeroes == unconditional rule. */
404 static inline int unconditional(const struct arpt_arp *arp)
408 for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
409 if (((__u32 *)arp)[i])
415 /* Figures out from what hook each rule can be called: returns 0 if
416 * there are loops. Puts hook bitmask in comefrom.
418 static int mark_source_chains(struct arpt_table_info *newinfo, unsigned int valid_hooks)
422 /* No recursion; use packet counter to save back ptrs (reset
423 * to 0 as we leave), and comefrom to save source hook bitmask.
425 for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
426 unsigned int pos = newinfo->hook_entry[hook];
428 = (struct arpt_entry *)(newinfo->entries + pos);
430 if (!(valid_hooks & (1 << hook)))
433 /* Set initial back pointer. */
434 e->counters.pcnt = pos;
437 struct arpt_standard_target *t
438 = (void *)arpt_get_target(e);
440 if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
441 printk("arptables: loop hook %u pos %u %08X.\n",
442 hook, pos, e->comefrom);
446 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
448 /* Unconditional return/END. */
449 if (e->target_offset == sizeof(struct arpt_entry)
450 && (strcmp(t->target.u.user.name,
451 ARPT_STANDARD_TARGET) == 0)
453 && unconditional(&e->arp)) {
454 unsigned int oldpos, size;
456 /* Return: backtrack through the last
460 e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
462 pos = e->counters.pcnt;
463 e->counters.pcnt = 0;
465 /* We're at the start. */
469 e = (struct arpt_entry *)
470 (newinfo->entries + pos);
471 } while (oldpos == pos + e->next_offset);
474 size = e->next_offset;
475 e = (struct arpt_entry *)
476 (newinfo->entries + pos + size);
477 e->counters.pcnt = pos;
480 int newpos = t->verdict;
482 if (strcmp(t->target.u.user.name,
483 ARPT_STANDARD_TARGET) == 0
485 /* This a jump; chase it. */
486 duprintf("Jump rule %u -> %u\n",
489 /* ... this is a fallthru */
490 newpos = pos + e->next_offset;
492 e = (struct arpt_entry *)
493 (newinfo->entries + newpos);
494 e->counters.pcnt = pos;
499 duprintf("Finished chain %u\n", hook);
504 static inline int standard_check(const struct arpt_entry_target *t,
505 unsigned int max_offset)
507 struct arpt_standard_target *targ = (void *)t;
509 /* Check standard info. */
511 != ARPT_ALIGN(sizeof(struct arpt_standard_target))) {
512 duprintf("arpt_standard_check: target size %u != %Zu\n",
514 ARPT_ALIGN(sizeof(struct arpt_standard_target)));
518 if (targ->verdict >= 0
519 && targ->verdict > max_offset - sizeof(struct arpt_entry)) {
520 duprintf("arpt_standard_check: bad verdict (%i)\n",
525 if (targ->verdict < -NF_MAX_VERDICT - 1) {
526 duprintf("arpt_standard_check: bad negative verdict (%i)\n",
533 static struct arpt_target arpt_standard_target;
535 static inline int check_entry(struct arpt_entry *e, const char *name, unsigned int size,
538 struct arpt_entry_target *t;
539 struct arpt_target *target;
542 if (!arp_checkentry(&e->arp)) {
543 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
547 t = arpt_get_target(e);
548 target = arpt_find_target_lock(t->u.user.name, &ret, &arpt_mutex);
550 duprintf("check_entry: `%s' not found\n", t->u.user.name);
553 if (!try_module_get((target->me))) {
557 t->u.kernel.target = target;
560 if (t->u.kernel.target == &arpt_standard_target) {
561 if (!standard_check(t, size)) {
565 } else if (t->u.kernel.target->checkentry
566 && !t->u.kernel.target->checkentry(name, e, t->data,
570 module_put(t->u.kernel.target->me);
571 duprintf("arp_tables: check failed for `%s'.\n",
572 t->u.kernel.target->name);
586 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
587 struct arpt_table_info *newinfo,
589 unsigned char *limit,
590 const unsigned int *hook_entries,
591 const unsigned int *underflows,
596 if ((unsigned long)e % __alignof__(struct arpt_entry) != 0
597 || (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
598 duprintf("Bad offset %p\n", e);
603 < sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) {
604 duprintf("checking: element %p size %u\n",
609 /* Check hooks & underflows */
610 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
611 if ((unsigned char *)e - base == hook_entries[h])
612 newinfo->hook_entry[h] = hook_entries[h];
613 if ((unsigned char *)e - base == underflows[h])
614 newinfo->underflow[h] = underflows[h];
617 /* FIXME: underflows must be unconditional, standard verdicts
618 < 0 (not ARPT_RETURN). --RR */
620 /* Clear counters and comefrom */
621 e->counters = ((struct arpt_counters) { 0, 0 });
628 static inline int cleanup_entry(struct arpt_entry *e, unsigned int *i)
630 struct arpt_entry_target *t;
632 if (i && (*i)-- == 0)
635 t = arpt_get_target(e);
636 if (t->u.kernel.target->destroy)
637 t->u.kernel.target->destroy(t->data,
638 t->u.target_size - sizeof(*t));
639 module_put(t->u.kernel.target->me);
643 /* Checks and translates the user-supplied table segment (held in
646 static int translate_table(const char *name,
647 unsigned int valid_hooks,
648 struct arpt_table_info *newinfo,
651 const unsigned int *hook_entries,
652 const unsigned int *underflows)
657 newinfo->size = size;
658 newinfo->number = number;
660 /* Init all hooks to impossible value. */
661 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
662 newinfo->hook_entry[i] = 0xFFFFFFFF;
663 newinfo->underflow[i] = 0xFFFFFFFF;
666 duprintf("translate_table: size %u\n", newinfo->size);
669 /* Walk through entries, checking offsets. */
670 ret = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
671 check_entry_size_and_hooks,
674 newinfo->entries + size,
675 hook_entries, underflows, &i);
676 duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
681 duprintf("translate_table: %u not %u entries\n",
686 /* Check hooks all assigned */
687 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
688 /* Only hooks which are valid */
689 if (!(valid_hooks & (1 << i)))
691 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
692 duprintf("Invalid hook entry %u %u\n",
696 if (newinfo->underflow[i] == 0xFFFFFFFF) {
697 duprintf("Invalid underflow %u %u\n",
703 if (!mark_source_chains(newinfo, valid_hooks)) {
704 duprintf("Looping hook\n");
708 /* Finally, each sanity check must pass */
710 ret = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
711 check_entry, name, size, &i);
714 ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
719 /* And one copy for every other CPU */
720 for (i = 1; i < NR_CPUS; i++) {
721 memcpy(newinfo->entries + SMP_ALIGN(newinfo->size)*i,
723 SMP_ALIGN(newinfo->size));
729 static struct arpt_table_info *replace_table(struct arpt_table *table,
730 unsigned int num_counters,
731 struct arpt_table_info *newinfo,
734 struct arpt_table_info *oldinfo;
736 /* Do the substitution. */
737 write_lock_bh(&table->lock);
738 /* Check inside lock: is the old number correct? */
739 if (num_counters != table->private->number) {
740 duprintf("num_counters != table->private->number (%u/%u)\n",
741 num_counters, table->private->number);
742 write_unlock_bh(&table->lock);
746 oldinfo = table->private;
747 table->private = newinfo;
748 newinfo->initial_entries = oldinfo->initial_entries;
749 write_unlock_bh(&table->lock);
755 static inline int add_entry_to_counter(const struct arpt_entry *e,
756 struct arpt_counters total[],
759 ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
765 static void get_counters(const struct arpt_table_info *t,
766 struct arpt_counters counters[])
771 for (cpu = 0; cpu < NR_CPUS; cpu++) {
773 ARPT_ENTRY_ITERATE(t->entries + TABLE_OFFSET(t, cpu),
775 add_entry_to_counter,
781 static int copy_entries_to_user(unsigned int total_size,
782 struct arpt_table *table,
783 void __user *userptr)
785 unsigned int off, num, countersize;
786 struct arpt_entry *e;
787 struct arpt_counters *counters;
790 /* We need atomic snapshot of counters: rest doesn't change
791 * (other than comefrom, which userspace doesn't care
794 countersize = sizeof(struct arpt_counters) * table->private->number;
795 counters = vmalloc(countersize);
797 if (counters == NULL)
800 /* First, sum counters... */
801 memset(counters, 0, countersize);
802 write_lock_bh(&table->lock);
803 get_counters(table->private, counters);
804 write_unlock_bh(&table->lock);
806 /* ... then copy entire thing from CPU 0... */
807 if (copy_to_user(userptr, table->private->entries, total_size) != 0) {
812 /* FIXME: use iterator macros --RR */
813 /* ... then go back and fix counters and names */
814 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
815 struct arpt_entry_target *t;
817 e = (struct arpt_entry *)(table->private->entries + off);
818 if (copy_to_user(userptr + off
819 + offsetof(struct arpt_entry, counters),
821 sizeof(counters[num])) != 0) {
826 t = arpt_get_target(e);
827 if (copy_to_user(userptr + off + e->target_offset
828 + offsetof(struct arpt_entry_target,
830 t->u.kernel.target->name,
831 strlen(t->u.kernel.target->name)+1) != 0) {
842 static int get_entries(const struct arpt_get_entries *entries,
843 struct arpt_get_entries __user *uptr)
846 struct arpt_table *t;
848 t = arpt_find_table_lock(entries->name, &ret, &arpt_mutex);
850 duprintf("t->private->number = %u\n",
852 if (entries->size == t->private->size)
853 ret = copy_entries_to_user(t->private->size,
854 t, uptr->entrytable);
856 duprintf("get_entries: I've got %u not %u!\n",
863 duprintf("get_entries: Can't find %s!\n",
869 static int do_replace(void __user *user, unsigned int len)
872 struct arpt_replace tmp;
873 struct arpt_table *t;
874 struct arpt_table_info *newinfo, *oldinfo;
875 struct arpt_counters *counters;
877 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
880 /* Hack: Causes ipchains to give correct error msg --RR */
881 if (len != sizeof(tmp) + tmp.size)
884 /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
885 if ((SMP_ALIGN(tmp.size) >> PAGE_SHIFT) + 2 > num_physpages)
888 newinfo = vmalloc(sizeof(struct arpt_table_info)
889 + SMP_ALIGN(tmp.size) * NR_CPUS);
893 if (copy_from_user(newinfo->entries, user + sizeof(tmp),
899 counters = vmalloc(tmp.num_counters * sizeof(struct arpt_counters));
904 memset(counters, 0, tmp.num_counters * sizeof(struct arpt_counters));
906 ret = translate_table(tmp.name, tmp.valid_hooks,
907 newinfo, tmp.size, tmp.num_entries,
908 tmp.hook_entry, tmp.underflow);
910 goto free_newinfo_counters;
912 duprintf("arp_tables: Translated table\n");
914 t = arpt_find_table_lock(tmp.name, &ret, &arpt_mutex);
916 goto free_newinfo_counters_untrans;
919 if (tmp.valid_hooks != t->valid_hooks) {
920 duprintf("Valid hook crap: %08X vs %08X\n",
921 tmp.valid_hooks, t->valid_hooks);
923 goto free_newinfo_counters_untrans_unlock;
926 /* Get a reference in advance, we're not allowed fail later */
927 if (!try_module_get(t->me)) {
929 goto free_newinfo_counters_untrans_unlock;
932 oldinfo = replace_table(t, tmp.num_counters, newinfo, &ret);
936 /* Update module usage count based on number of rules */
937 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
938 oldinfo->number, oldinfo->initial_entries, newinfo->number);
939 if ((oldinfo->number > oldinfo->initial_entries) ||
940 (newinfo->number <= oldinfo->initial_entries))
942 if ((oldinfo->number > oldinfo->initial_entries) &&
943 (newinfo->number <= oldinfo->initial_entries))
946 /* Get the old counters. */
947 get_counters(oldinfo, counters);
948 /* Decrease module usage counts and free resource */
949 ARPT_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL);
951 /* Silent error: too late now. */
952 copy_to_user(tmp.counters, counters,
953 sizeof(struct arpt_counters) * tmp.num_counters);
960 free_newinfo_counters_untrans_unlock:
962 free_newinfo_counters_untrans:
963 ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, cleanup_entry, NULL);
964 free_newinfo_counters:
971 /* We're lazy, and add to the first CPU; overflow works its fey magic
972 * and everything is OK.
974 static inline int add_counter_to_entry(struct arpt_entry *e,
975 const struct arpt_counters addme[],
979 ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
985 static int do_add_counters(void __user *user, unsigned int len)
988 struct arpt_counters_info tmp, *paddc;
989 struct arpt_table *t;
992 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
995 if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct arpt_counters))
998 paddc = vmalloc(len);
1002 if (copy_from_user(paddc, user, len) != 0) {
1007 t = arpt_find_table_lock(tmp.name, &ret, &arpt_mutex);
1011 write_lock_bh(&t->lock);
1012 if (t->private->number != paddc->num_counters) {
1014 goto unlock_up_free;
1018 ARPT_ENTRY_ITERATE(t->private->entries,
1020 add_counter_to_entry,
1024 write_unlock_bh(&t->lock);
1032 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1036 if (!capable(CAP_NET_ADMIN))
1040 case ARPT_SO_SET_REPLACE:
1041 ret = do_replace(user, len);
1044 case ARPT_SO_SET_ADD_COUNTERS:
1045 ret = do_add_counters(user, len);
1049 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1056 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1060 if (!capable(CAP_NET_ADMIN))
1064 case ARPT_SO_GET_INFO: {
1065 char name[ARPT_TABLE_MAXNAMELEN];
1066 struct arpt_table *t;
1068 if (*len != sizeof(struct arpt_getinfo)) {
1069 duprintf("length %u != %Zu\n", *len,
1070 sizeof(struct arpt_getinfo));
1075 if (copy_from_user(name, user, sizeof(name)) != 0) {
1079 name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
1080 t = arpt_find_table_lock(name, &ret, &arpt_mutex);
1082 struct arpt_getinfo info;
1084 info.valid_hooks = t->valid_hooks;
1085 memcpy(info.hook_entry, t->private->hook_entry,
1086 sizeof(info.hook_entry));
1087 memcpy(info.underflow, t->private->underflow,
1088 sizeof(info.underflow));
1089 info.num_entries = t->private->number;
1090 info.size = t->private->size;
1091 strcpy(info.name, name);
1093 if (copy_to_user(user, &info, *len) != 0)
1103 case ARPT_SO_GET_ENTRIES: {
1104 struct arpt_get_entries get;
1106 if (*len < sizeof(get)) {
1107 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
1109 } else if (copy_from_user(&get, user, sizeof(get)) != 0) {
1111 } else if (*len != sizeof(struct arpt_get_entries) + get.size) {
1112 duprintf("get_entries: %u != %Zu\n", *len,
1113 sizeof(struct arpt_get_entries) + get.size);
1116 ret = get_entries(&get, user);
1121 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1128 /* Registration hooks for targets. */
1129 int arpt_register_target(struct arpt_target *target)
1133 ret = down_interruptible(&arpt_mutex);
1137 if (!list_named_insert(&arpt_target, target)) {
1138 duprintf("arpt_register_target: `%s' already in list!\n",
1146 void arpt_unregister_target(struct arpt_target *target)
1149 LIST_DELETE(&arpt_target, target);
1153 int arpt_register_table(struct arpt_table *table)
1156 struct arpt_table_info *newinfo;
1157 static struct arpt_table_info bootstrap
1158 = { 0, 0, 0, { 0 }, { 0 }, { } };
1160 newinfo = vmalloc(sizeof(struct arpt_table_info)
1161 + SMP_ALIGN(table->table->size) * NR_CPUS);
1166 memcpy(newinfo->entries, table->table->entries, table->table->size);
1168 ret = translate_table(table->name, table->valid_hooks,
1169 newinfo, table->table->size,
1170 table->table->num_entries,
1171 table->table->hook_entry,
1172 table->table->underflow);
1173 duprintf("arpt_register_table: translate table gives %d\n", ret);
1179 ret = down_interruptible(&arpt_mutex);
1185 /* Don't autoload: we'd eat our tail... */
1186 if (list_named_find(&arpt_tables, table->name)) {
1191 /* Simplifies replace_table code. */
1192 table->private = &bootstrap;
1193 if (!replace_table(table, 0, newinfo, &ret))
1196 duprintf("table->private->number = %u\n",
1197 table->private->number);
1199 /* save number of initial entries */
1200 table->private->initial_entries = table->private->number;
1202 table->lock = RW_LOCK_UNLOCKED;
1203 list_prepend(&arpt_tables, table);
1214 void arpt_unregister_table(struct arpt_table *table)
1217 LIST_DELETE(&arpt_tables, table);
1220 /* Decrease module usage counts and free resources */
1221 ARPT_ENTRY_ITERATE(table->private->entries, table->private->size,
1222 cleanup_entry, NULL);
1223 vfree(table->private);
1226 /* The built-in targets: standard (NULL) and error. */
1227 static struct arpt_target arpt_standard_target = {
1228 .name = ARPT_STANDARD_TARGET,
1231 static struct arpt_target arpt_error_target = {
1232 .name = ARPT_ERROR_TARGET,
1233 .target = arpt_error,
1236 static struct nf_sockopt_ops arpt_sockopts = {
1238 .set_optmin = ARPT_BASE_CTL,
1239 .set_optmax = ARPT_SO_SET_MAX+1,
1240 .set = do_arpt_set_ctl,
1241 .get_optmin = ARPT_BASE_CTL,
1242 .get_optmax = ARPT_SO_GET_MAX+1,
1243 .get = do_arpt_get_ctl,
1246 #ifdef CONFIG_PROC_FS
1247 static inline int print_name(const struct arpt_table *t,
1248 off_t start_offset, char *buffer, int length,
1249 off_t *pos, unsigned int *count)
1251 if ((*count)++ >= start_offset) {
1252 unsigned int namelen;
1254 namelen = sprintf(buffer + *pos, "%s\n", t->name);
1255 if (*pos + namelen > length) {
1256 /* Stop iterating */
1264 static int arpt_get_tables(char *buffer, char **start, off_t offset, int length)
1267 unsigned int count = 0;
1269 if (down_interruptible(&arpt_mutex) != 0)
1272 LIST_FIND(&arpt_tables, print_name, struct arpt_table *,
1273 offset, buffer, length, &pos, &count);
1277 /* `start' hack - see fs/proc/generic.c line ~105 */
1278 *start=(char *)((unsigned long)count-offset);
1281 #endif /*CONFIG_PROC_FS*/
1283 static int __init init(void)
1287 /* Noone else will be downing sem now, so we won't sleep */
1289 list_append(&arpt_target, &arpt_standard_target);
1290 list_append(&arpt_target, &arpt_error_target);
1293 /* Register setsockopt */
1294 ret = nf_register_sockopt(&arpt_sockopts);
1296 duprintf("Unable to register sockopts.\n");
1300 #ifdef CONFIG_PROC_FS
1302 struct proc_dir_entry *proc;
1304 proc = proc_net_create("arp_tables_names", 0, arpt_get_tables);
1306 nf_unregister_sockopt(&arpt_sockopts);
1309 proc->owner = THIS_MODULE;
1313 printk("arp_tables: (C) 2002 David S. Miller\n");
1317 static void __exit fini(void)
1319 nf_unregister_sockopt(&arpt_sockopts);
1320 #ifdef CONFIG_PROC_FS
1321 proc_net_remove("arp_tables_names");
1325 EXPORT_SYMBOL(arpt_register_table);
1326 EXPORT_SYMBOL(arpt_unregister_table);
1327 EXPORT_SYMBOL(arpt_do_table);
1328 EXPORT_SYMBOL(arpt_find_target_lock);
1329 EXPORT_SYMBOL(arpt_register_target);
1330 EXPORT_SYMBOL(arpt_unregister_target);