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 src_ipaddr = (u32 *) arpptr;
149 arpptr += sizeof(u32);
150 tgt_devaddr = arpptr;
151 arpptr += dev->addr_len;
152 tgt_ipaddr = (u32 *) arpptr;
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",
170 NIPQUAD(*src_ipaddr),
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",
175 NIPQUAD(*tgt_ipaddr),
176 NIPQUAD(arpinfo->tmsk.s_addr),
177 NIPQUAD(arpinfo->tgt.s_addr),
178 arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
182 /* Look for ifname matches; this should unroll nicely. */
183 for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
184 ret |= (((const unsigned long *)indev)[i]
185 ^ ((const unsigned long *)arpinfo->iniface)[i])
186 & ((const unsigned long *)arpinfo->iniface_mask)[i];
189 if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
190 dprintf("VIA in mismatch (%s vs %s).%s\n",
191 indev, arpinfo->iniface,
192 arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
196 for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
197 ret |= (((const unsigned long *)outdev)[i]
198 ^ ((const unsigned long *)arpinfo->outiface)[i])
199 & ((const unsigned long *)arpinfo->outiface_mask)[i];
202 if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
203 dprintf("VIA out mismatch (%s vs %s).%s\n",
204 outdev, arpinfo->outiface,
205 arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
212 static inline int arp_checkentry(const struct arpt_arp *arp)
214 if (arp->flags & ~ARPT_F_MASK) {
215 duprintf("Unknown flag bits set: %08X\n",
216 arp->flags & ~ARPT_F_MASK);
219 if (arp->invflags & ~ARPT_INV_MASK) {
220 duprintf("Unknown invflag bits set: %08X\n",
221 arp->invflags & ~ARPT_INV_MASK);
228 static unsigned int arpt_error(struct sk_buff **pskb,
229 unsigned int hooknum,
230 const struct net_device *in,
231 const struct net_device *out,
232 const void *targinfo,
236 printk("arp_tables: error: '%s'\n", (char *)targinfo);
241 static inline struct arpt_entry *get_entry(void *base, unsigned int offset)
243 return (struct arpt_entry *)(base + offset);
246 unsigned int arpt_do_table(struct sk_buff **pskb,
248 const struct net_device *in,
249 const struct net_device *out,
250 struct arpt_table *table,
253 static const char nulldevname[IFNAMSIZ];
254 unsigned int verdict = NF_DROP;
257 struct arpt_entry *e, *back;
258 const char *indev, *outdev;
261 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
262 if (!pskb_may_pull((*pskb), (sizeof(struct arphdr) +
263 (2 * (*pskb)->dev->addr_len) +
267 indev = in ? in->name : nulldevname;
268 outdev = out ? out->name : nulldevname;
270 read_lock_bh(&table->lock);
271 table_base = (void *)table->private->entries
272 + TABLE_OFFSET(table->private,
274 e = get_entry(table_base, table->private->hook_entry[hook]);
275 back = get_entry(table_base, table->private->underflow[hook]);
277 arp = (*pskb)->nh.arph;
279 if (arp_packet_match(arp, (*pskb)->dev, indev, outdev, &e->arp)) {
280 struct arpt_entry_target *t;
283 hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
284 (2 * (*pskb)->dev->addr_len);
285 ADD_COUNTER(e->counters, hdr_len, 1);
287 t = arpt_get_target(e);
289 /* Standard target? */
290 if (!t->u.kernel.target->target) {
293 v = ((struct arpt_standard_target *)t)->verdict;
295 /* Pop from stack? */
296 if (v != ARPT_RETURN) {
297 verdict = (unsigned)(-v) - 1;
301 back = get_entry(table_base,
306 != (void *)e + e->next_offset) {
307 /* Save old back ptr in next entry */
308 struct arpt_entry *next
309 = (void *)e + e->next_offset;
311 (void *)back - table_base;
313 /* set back pointer to next entry */
317 e = get_entry(table_base, v);
319 /* Targets which reenter must return
322 verdict = t->u.kernel.target->target(pskb,
328 /* Target might have changed stuff. */
329 arp = (*pskb)->nh.arph;
331 if (verdict == ARPT_CONTINUE)
332 e = (void *)e + e->next_offset;
338 e = (void *)e + e->next_offset;
341 read_unlock_bh(&table->lock);
349 static inline void *find_inlist_lock_noload(struct list_head *head,
352 struct semaphore *mutex)
356 *error = down_interruptible(mutex);
360 ret = list_named_find(head, name);
369 #define find_inlist_lock(h,n,p,e,m) find_inlist_lock_noload((h),(n),(e),(m))
372 find_inlist_lock(struct list_head *head,
376 struct semaphore *mutex)
380 ret = find_inlist_lock_noload(head, name, error, mutex);
382 duprintf("find_inlist: loading `%s%s'.\n", prefix, name);
383 request_module("%s%s", prefix, name);
384 ret = find_inlist_lock_noload(head, name, error, mutex);
391 static inline struct arpt_table *find_table_lock(const char *name, int *error, struct semaphore *mutex)
393 return find_inlist_lock(&arpt_tables, name, "arptable_", error, mutex);
396 static inline struct arpt_target *find_target_lock(const char *name, int *error, struct semaphore *mutex)
398 return find_inlist_lock(&arpt_target, name, "arpt_", error, mutex);
401 /* All zeroes == unconditional rule. */
402 static inline int unconditional(const struct arpt_arp *arp)
406 for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
407 if (((__u32 *)arp)[i])
413 /* Figures out from what hook each rule can be called: returns 0 if
414 * there are loops. Puts hook bitmask in comefrom.
416 static int mark_source_chains(struct arpt_table_info *newinfo, unsigned int valid_hooks)
420 /* No recursion; use packet counter to save back ptrs (reset
421 * to 0 as we leave), and comefrom to save source hook bitmask.
423 for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
424 unsigned int pos = newinfo->hook_entry[hook];
426 = (struct arpt_entry *)(newinfo->entries + pos);
428 if (!(valid_hooks & (1 << hook)))
431 /* Set initial back pointer. */
432 e->counters.pcnt = pos;
435 struct arpt_standard_target *t
436 = (void *)arpt_get_target(e);
438 if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
439 printk("arptables: loop hook %u pos %u %08X.\n",
440 hook, pos, e->comefrom);
444 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
446 /* Unconditional return/END. */
447 if (e->target_offset == sizeof(struct arpt_entry)
448 && (strcmp(t->target.u.user.name,
449 ARPT_STANDARD_TARGET) == 0)
451 && unconditional(&e->arp)) {
452 unsigned int oldpos, size;
454 /* Return: backtrack through the last
458 e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
460 pos = e->counters.pcnt;
461 e->counters.pcnt = 0;
463 /* We're at the start. */
467 e = (struct arpt_entry *)
468 (newinfo->entries + pos);
469 } while (oldpos == pos + e->next_offset);
472 size = e->next_offset;
473 e = (struct arpt_entry *)
474 (newinfo->entries + pos + size);
475 e->counters.pcnt = pos;
478 int newpos = t->verdict;
480 if (strcmp(t->target.u.user.name,
481 ARPT_STANDARD_TARGET) == 0
483 /* This a jump; chase it. */
484 duprintf("Jump rule %u -> %u\n",
487 /* ... this is a fallthru */
488 newpos = pos + e->next_offset;
490 e = (struct arpt_entry *)
491 (newinfo->entries + newpos);
492 e->counters.pcnt = pos;
497 duprintf("Finished chain %u\n", hook);
502 static inline int standard_check(const struct arpt_entry_target *t,
503 unsigned int max_offset)
505 struct arpt_standard_target *targ = (void *)t;
507 /* Check standard info. */
509 != ARPT_ALIGN(sizeof(struct arpt_standard_target))) {
510 duprintf("arpt_standard_check: target size %u != %Zu\n",
512 ARPT_ALIGN(sizeof(struct arpt_standard_target)));
516 if (targ->verdict >= 0
517 && targ->verdict > max_offset - sizeof(struct arpt_entry)) {
518 duprintf("arpt_standard_check: bad verdict (%i)\n",
523 if (targ->verdict < -NF_MAX_VERDICT - 1) {
524 duprintf("arpt_standard_check: bad negative verdict (%i)\n",
531 static struct arpt_target arpt_standard_target;
533 static inline int check_entry(struct arpt_entry *e, const char *name, unsigned int size,
536 struct arpt_entry_target *t;
537 struct arpt_target *target;
540 if (!arp_checkentry(&e->arp)) {
541 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
545 t = arpt_get_target(e);
546 target = find_target_lock(t->u.user.name, &ret, &arpt_mutex);
548 duprintf("check_entry: `%s' not found\n", t->u.user.name);
551 if (!try_module_get((target->me))) {
555 t->u.kernel.target = target;
558 if (t->u.kernel.target == &arpt_standard_target) {
559 if (!standard_check(t, size)) {
563 } else if (t->u.kernel.target->checkentry
564 && !t->u.kernel.target->checkentry(name, e, t->data,
568 module_put(t->u.kernel.target->me);
569 duprintf("arp_tables: check failed for `%s'.\n",
570 t->u.kernel.target->name);
584 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
585 struct arpt_table_info *newinfo,
587 unsigned char *limit,
588 const unsigned int *hook_entries,
589 const unsigned int *underflows,
594 if ((unsigned long)e % __alignof__(struct arpt_entry) != 0
595 || (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
596 duprintf("Bad offset %p\n", e);
601 < sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) {
602 duprintf("checking: element %p size %u\n",
607 /* Check hooks & underflows */
608 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
609 if ((unsigned char *)e - base == hook_entries[h])
610 newinfo->hook_entry[h] = hook_entries[h];
611 if ((unsigned char *)e - base == underflows[h])
612 newinfo->underflow[h] = underflows[h];
615 /* FIXME: underflows must be unconditional, standard verdicts
616 < 0 (not ARPT_RETURN). --RR */
618 /* Clear counters and comefrom */
619 e->counters = ((struct arpt_counters) { 0, 0 });
626 static inline int cleanup_entry(struct arpt_entry *e, unsigned int *i)
628 struct arpt_entry_target *t;
630 if (i && (*i)-- == 0)
633 t = arpt_get_target(e);
634 if (t->u.kernel.target->destroy)
635 t->u.kernel.target->destroy(t->data,
636 t->u.target_size - sizeof(*t));
637 module_put(t->u.kernel.target->me);
641 /* Checks and translates the user-supplied table segment (held in
644 static int translate_table(const char *name,
645 unsigned int valid_hooks,
646 struct arpt_table_info *newinfo,
649 const unsigned int *hook_entries,
650 const unsigned int *underflows)
655 newinfo->size = size;
656 newinfo->number = number;
658 /* Init all hooks to impossible value. */
659 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
660 newinfo->hook_entry[i] = 0xFFFFFFFF;
661 newinfo->underflow[i] = 0xFFFFFFFF;
664 duprintf("translate_table: size %u\n", newinfo->size);
667 /* Walk through entries, checking offsets. */
668 ret = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
669 check_entry_size_and_hooks,
672 newinfo->entries + size,
673 hook_entries, underflows, &i);
674 duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
679 duprintf("translate_table: %u not %u entries\n",
684 /* Check hooks all assigned */
685 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
686 /* Only hooks which are valid */
687 if (!(valid_hooks & (1 << i)))
689 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
690 duprintf("Invalid hook entry %u %u\n",
694 if (newinfo->underflow[i] == 0xFFFFFFFF) {
695 duprintf("Invalid underflow %u %u\n",
701 if (!mark_source_chains(newinfo, valid_hooks)) {
702 duprintf("Looping hook\n");
706 /* Finally, each sanity check must pass */
708 ret = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
709 check_entry, name, size, &i);
712 ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
717 /* And one copy for every other CPU */
718 for (i = 1; i < NR_CPUS; i++) {
719 memcpy(newinfo->entries + SMP_ALIGN(newinfo->size)*i,
721 SMP_ALIGN(newinfo->size));
727 static struct arpt_table_info *replace_table(struct arpt_table *table,
728 unsigned int num_counters,
729 struct arpt_table_info *newinfo,
732 struct arpt_table_info *oldinfo;
734 /* Do the substitution. */
735 write_lock_bh(&table->lock);
736 /* Check inside lock: is the old number correct? */
737 if (num_counters != table->private->number) {
738 duprintf("num_counters != table->private->number (%u/%u)\n",
739 num_counters, table->private->number);
740 write_unlock_bh(&table->lock);
744 oldinfo = table->private;
745 table->private = newinfo;
746 newinfo->initial_entries = oldinfo->initial_entries;
747 write_unlock_bh(&table->lock);
753 static inline int add_entry_to_counter(const struct arpt_entry *e,
754 struct arpt_counters total[],
757 ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
763 static void get_counters(const struct arpt_table_info *t,
764 struct arpt_counters counters[])
769 for (cpu = 0; cpu < NR_CPUS; cpu++) {
771 ARPT_ENTRY_ITERATE(t->entries + TABLE_OFFSET(t, cpu),
773 add_entry_to_counter,
779 static int copy_entries_to_user(unsigned int total_size,
780 struct arpt_table *table,
781 void __user *userptr)
783 unsigned int off, num, countersize;
784 struct arpt_entry *e;
785 struct arpt_counters *counters;
788 /* We need atomic snapshot of counters: rest doesn't change
789 * (other than comefrom, which userspace doesn't care
792 countersize = sizeof(struct arpt_counters) * table->private->number;
793 counters = vmalloc(countersize);
795 if (counters == NULL)
798 /* First, sum counters... */
799 memset(counters, 0, countersize);
800 write_lock_bh(&table->lock);
801 get_counters(table->private, counters);
802 write_unlock_bh(&table->lock);
804 /* ... then copy entire thing from CPU 0... */
805 if (copy_to_user(userptr, table->private->entries, total_size) != 0) {
810 /* FIXME: use iterator macros --RR */
811 /* ... then go back and fix counters and names */
812 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
813 struct arpt_entry_target *t;
815 e = (struct arpt_entry *)(table->private->entries + off);
816 if (copy_to_user(userptr + off
817 + offsetof(struct arpt_entry, counters),
819 sizeof(counters[num])) != 0) {
824 t = arpt_get_target(e);
825 if (copy_to_user(userptr + off + e->target_offset
826 + offsetof(struct arpt_entry_target,
828 t->u.kernel.target->name,
829 strlen(t->u.kernel.target->name)+1) != 0) {
840 static int get_entries(const struct arpt_get_entries *entries,
841 struct arpt_get_entries __user *uptr)
844 struct arpt_table *t;
846 t = find_table_lock(entries->name, &ret, &arpt_mutex);
848 duprintf("t->private->number = %u\n",
850 if (entries->size == t->private->size)
851 ret = copy_entries_to_user(t->private->size,
852 t, uptr->entrytable);
854 duprintf("get_entries: I've got %u not %u!\n",
861 duprintf("get_entries: Can't find %s!\n",
867 static int do_replace(void __user *user, unsigned int len)
870 struct arpt_replace tmp;
871 struct arpt_table *t;
872 struct arpt_table_info *newinfo, *oldinfo;
873 struct arpt_counters *counters;
875 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
878 /* Hack: Causes ipchains to give correct error msg --RR */
879 if (len != sizeof(tmp) + tmp.size)
882 /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
883 if ((SMP_ALIGN(tmp.size) >> PAGE_SHIFT) + 2 > num_physpages)
886 newinfo = vmalloc(sizeof(struct arpt_table_info)
887 + SMP_ALIGN(tmp.size) * NR_CPUS);
891 if (copy_from_user(newinfo->entries, user + sizeof(tmp),
897 counters = vmalloc(tmp.num_counters * sizeof(struct arpt_counters));
902 memset(counters, 0, tmp.num_counters * sizeof(struct arpt_counters));
904 ret = translate_table(tmp.name, tmp.valid_hooks,
905 newinfo, tmp.size, tmp.num_entries,
906 tmp.hook_entry, tmp.underflow);
908 goto free_newinfo_counters;
910 duprintf("arp_tables: Translated table\n");
912 t = find_table_lock(tmp.name, &ret, &arpt_mutex);
914 goto free_newinfo_counters_untrans;
917 if (tmp.valid_hooks != t->valid_hooks) {
918 duprintf("Valid hook crap: %08X vs %08X\n",
919 tmp.valid_hooks, t->valid_hooks);
921 goto free_newinfo_counters_untrans_unlock;
924 /* Get a reference in advance, we're not allowed fail later */
925 if (!try_module_get(t->me)) {
927 goto free_newinfo_counters_untrans_unlock;
930 oldinfo = replace_table(t, tmp.num_counters, newinfo, &ret);
934 /* Update module usage count based on number of rules */
935 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
936 oldinfo->number, oldinfo->initial_entries, newinfo->number);
937 if ((oldinfo->number > oldinfo->initial_entries) ||
938 (newinfo->number <= oldinfo->initial_entries))
940 if ((oldinfo->number > oldinfo->initial_entries) &&
941 (newinfo->number <= oldinfo->initial_entries))
944 /* Get the old counters. */
945 get_counters(oldinfo, counters);
946 /* Decrease module usage counts and free resource */
947 ARPT_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL);
949 /* Silent error: too late now. */
950 copy_to_user(tmp.counters, counters,
951 sizeof(struct arpt_counters) * tmp.num_counters);
958 free_newinfo_counters_untrans_unlock:
960 free_newinfo_counters_untrans:
961 ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, cleanup_entry, NULL);
962 free_newinfo_counters:
969 /* We're lazy, and add to the first CPU; overflow works its fey magic
970 * and everything is OK.
972 static inline int add_counter_to_entry(struct arpt_entry *e,
973 const struct arpt_counters addme[],
977 ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
983 static int do_add_counters(void __user *user, unsigned int len)
986 struct arpt_counters_info tmp, *paddc;
987 struct arpt_table *t;
990 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
993 if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct arpt_counters))
996 paddc = vmalloc(len);
1000 if (copy_from_user(paddc, user, len) != 0) {
1005 t = find_table_lock(tmp.name, &ret, &arpt_mutex);
1009 write_lock_bh(&t->lock);
1010 if (t->private->number != paddc->num_counters) {
1012 goto unlock_up_free;
1016 ARPT_ENTRY_ITERATE(t->private->entries,
1018 add_counter_to_entry,
1022 write_unlock_bh(&t->lock);
1030 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1034 if (!capable(CAP_NET_ADMIN))
1038 case ARPT_SO_SET_REPLACE:
1039 ret = do_replace(user, len);
1042 case ARPT_SO_SET_ADD_COUNTERS:
1043 ret = do_add_counters(user, len);
1047 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1054 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1058 if (!capable(CAP_NET_ADMIN))
1062 case ARPT_SO_GET_INFO: {
1063 char name[ARPT_TABLE_MAXNAMELEN];
1064 struct arpt_table *t;
1066 if (*len != sizeof(struct arpt_getinfo)) {
1067 duprintf("length %u != %Zu\n", *len,
1068 sizeof(struct arpt_getinfo));
1073 if (copy_from_user(name, user, sizeof(name)) != 0) {
1077 name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
1078 t = find_table_lock(name, &ret, &arpt_mutex);
1080 struct arpt_getinfo info;
1082 info.valid_hooks = t->valid_hooks;
1083 memcpy(info.hook_entry, t->private->hook_entry,
1084 sizeof(info.hook_entry));
1085 memcpy(info.underflow, t->private->underflow,
1086 sizeof(info.underflow));
1087 info.num_entries = t->private->number;
1088 info.size = t->private->size;
1089 strcpy(info.name, name);
1091 if (copy_to_user(user, &info, *len) != 0)
1101 case ARPT_SO_GET_ENTRIES: {
1102 struct arpt_get_entries get;
1104 if (*len < sizeof(get)) {
1105 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
1107 } else if (copy_from_user(&get, user, sizeof(get)) != 0) {
1109 } else if (*len != sizeof(struct arpt_get_entries) + get.size) {
1110 duprintf("get_entries: %u != %Zu\n", *len,
1111 sizeof(struct arpt_get_entries) + get.size);
1114 ret = get_entries(&get, user);
1119 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1126 /* Registration hooks for targets. */
1127 int arpt_register_target(struct arpt_target *target)
1131 ret = down_interruptible(&arpt_mutex);
1135 if (!list_named_insert(&arpt_target, target)) {
1136 duprintf("arpt_register_target: `%s' already in list!\n",
1144 void arpt_unregister_target(struct arpt_target *target)
1147 LIST_DELETE(&arpt_target, target);
1151 int arpt_register_table(struct arpt_table *table)
1154 struct arpt_table_info *newinfo;
1155 static struct arpt_table_info bootstrap
1156 = { 0, 0, 0, { 0 }, { 0 }, { } };
1158 newinfo = vmalloc(sizeof(struct arpt_table_info)
1159 + SMP_ALIGN(table->table->size) * NR_CPUS);
1164 memcpy(newinfo->entries, table->table->entries, table->table->size);
1166 ret = translate_table(table->name, table->valid_hooks,
1167 newinfo, table->table->size,
1168 table->table->num_entries,
1169 table->table->hook_entry,
1170 table->table->underflow);
1171 duprintf("arpt_register_table: translate table gives %d\n", ret);
1177 ret = down_interruptible(&arpt_mutex);
1183 /* Don't autoload: we'd eat our tail... */
1184 if (list_named_find(&arpt_tables, table->name)) {
1189 /* Simplifies replace_table code. */
1190 table->private = &bootstrap;
1191 if (!replace_table(table, 0, newinfo, &ret))
1194 duprintf("table->private->number = %u\n",
1195 table->private->number);
1197 /* save number of initial entries */
1198 table->private->initial_entries = table->private->number;
1200 table->lock = RW_LOCK_UNLOCKED;
1201 list_prepend(&arpt_tables, table);
1212 void arpt_unregister_table(struct arpt_table *table)
1215 LIST_DELETE(&arpt_tables, table);
1218 /* Decrease module usage counts and free resources */
1219 ARPT_ENTRY_ITERATE(table->private->entries, table->private->size,
1220 cleanup_entry, NULL);
1221 vfree(table->private);
1224 /* The built-in targets: standard (NULL) and error. */
1225 static struct arpt_target arpt_standard_target = {
1226 .name = ARPT_STANDARD_TARGET,
1229 static struct arpt_target arpt_error_target = {
1230 .name = ARPT_ERROR_TARGET,
1231 .target = arpt_error,
1234 static struct nf_sockopt_ops arpt_sockopts = {
1236 .set_optmin = ARPT_BASE_CTL,
1237 .set_optmax = ARPT_SO_SET_MAX+1,
1238 .set = do_arpt_set_ctl,
1239 .get_optmin = ARPT_BASE_CTL,
1240 .get_optmax = ARPT_SO_GET_MAX+1,
1241 .get = do_arpt_get_ctl,
1244 #ifdef CONFIG_PROC_FS
1245 static inline int print_name(const struct arpt_table *t,
1246 off_t start_offset, char *buffer, int length,
1247 off_t *pos, unsigned int *count)
1249 if ((*count)++ >= start_offset) {
1250 unsigned int namelen;
1252 namelen = sprintf(buffer + *pos, "%s\n", t->name);
1253 if (*pos + namelen > length) {
1254 /* Stop iterating */
1262 static int arpt_get_tables(char *buffer, char **start, off_t offset, int length)
1265 unsigned int count = 0;
1267 if (down_interruptible(&arpt_mutex) != 0)
1270 LIST_FIND(&arpt_tables, print_name, struct arpt_table *,
1271 offset, buffer, length, &pos, &count);
1275 /* `start' hack - see fs/proc/generic.c line ~105 */
1276 *start=(char *)((unsigned long)count-offset);
1279 #endif /*CONFIG_PROC_FS*/
1281 static int __init init(void)
1285 /* Noone else will be downing sem now, so we won't sleep */
1287 list_append(&arpt_target, &arpt_standard_target);
1288 list_append(&arpt_target, &arpt_error_target);
1291 /* Register setsockopt */
1292 ret = nf_register_sockopt(&arpt_sockopts);
1294 duprintf("Unable to register sockopts.\n");
1298 #ifdef CONFIG_PROC_FS
1300 struct proc_dir_entry *proc;
1302 proc = proc_net_create("arp_tables_names", 0, arpt_get_tables);
1304 nf_unregister_sockopt(&arpt_sockopts);
1307 proc->owner = THIS_MODULE;
1311 printk("arp_tables: (C) 2002 David S. Miller\n");
1315 static void __exit fini(void)
1317 nf_unregister_sockopt(&arpt_sockopts);
1318 #ifdef CONFIG_PROC_FS
1319 proc_net_remove("arp_tables_names");
1323 EXPORT_SYMBOL(arpt_register_table);
1324 EXPORT_SYMBOL(arpt_unregister_table);
1325 EXPORT_SYMBOL(arpt_do_table);
1326 EXPORT_SYMBOL(arpt_register_target);
1327 EXPORT_SYMBOL(arpt_unregister_target);