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/kernel.h>
13 #include <linux/skbuff.h>
14 #include <linux/netdevice.h>
15 #include <linux/capability.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>
22 #include <linux/mutex.h>
23 #include <linux/err.h>
24 #include <net/compat.h>
26 #include <asm/uaccess.h>
28 #include <linux/netfilter/x_tables.h>
29 #include <linux/netfilter_arp/arp_tables.h>
31 MODULE_LICENSE("GPL");
32 MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
33 MODULE_DESCRIPTION("arptables core");
35 /*#define DEBUG_ARP_TABLES*/
36 /*#define DEBUG_ARP_TABLES_USER*/
38 #ifdef DEBUG_ARP_TABLES
39 #define dprintf(format, args...) printk(format , ## args)
41 #define dprintf(format, args...)
44 #ifdef DEBUG_ARP_TABLES_USER
45 #define duprintf(format, args...) printk(format , ## args)
47 #define duprintf(format, args...)
50 #ifdef CONFIG_NETFILTER_DEBUG
51 #define ARP_NF_ASSERT(x) \
54 printk("ARP_NF_ASSERT: %s:%s:%u\n", \
55 __func__, __FILE__, __LINE__); \
58 #define ARP_NF_ASSERT(x)
61 static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
62 const char *hdr_addr, int len)
66 if (len > ARPT_DEV_ADDR_LEN_MAX)
67 len = ARPT_DEV_ADDR_LEN_MAX;
70 for (i = 0; i < len; i++)
71 ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
76 /* Returns whether packet matches rule or not. */
77 static inline int arp_packet_match(const struct arphdr *arphdr,
78 struct net_device *dev,
81 const struct arpt_arp *arpinfo)
83 const char *arpptr = (char *)(arphdr + 1);
84 const char *src_devaddr, *tgt_devaddr;
85 __be32 src_ipaddr, tgt_ipaddr;
88 #define FWINV(bool, invflg) ((bool) ^ !!(arpinfo->invflags & (invflg)))
90 if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
92 dprintf("ARP operation field mismatch.\n");
93 dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
94 arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
98 if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
100 dprintf("ARP hardware address format mismatch.\n");
101 dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
102 arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
106 if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
108 dprintf("ARP protocol address format mismatch.\n");
109 dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
110 arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
114 if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
116 dprintf("ARP hardware address length mismatch.\n");
117 dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
118 arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
122 src_devaddr = arpptr;
123 arpptr += dev->addr_len;
124 memcpy(&src_ipaddr, arpptr, sizeof(u32));
125 arpptr += sizeof(u32);
126 tgt_devaddr = arpptr;
127 arpptr += dev->addr_len;
128 memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
130 if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
131 ARPT_INV_SRCDEVADDR) ||
132 FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
133 ARPT_INV_TGTDEVADDR)) {
134 dprintf("Source or target device address mismatch.\n");
139 if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
141 FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
143 dprintf("Source or target IP address mismatch.\n");
145 dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
147 NIPQUAD(arpinfo->smsk.s_addr),
148 NIPQUAD(arpinfo->src.s_addr),
149 arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
150 dprintf("TGT: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
152 NIPQUAD(arpinfo->tmsk.s_addr),
153 NIPQUAD(arpinfo->tgt.s_addr),
154 arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
158 /* Look for ifname matches. */
159 for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
160 ret |= (indev[i] ^ arpinfo->iniface[i])
161 & arpinfo->iniface_mask[i];
164 if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
165 dprintf("VIA in mismatch (%s vs %s).%s\n",
166 indev, arpinfo->iniface,
167 arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
171 for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
172 ret |= (outdev[i] ^ arpinfo->outiface[i])
173 & arpinfo->outiface_mask[i];
176 if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
177 dprintf("VIA out mismatch (%s vs %s).%s\n",
178 outdev, arpinfo->outiface,
179 arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
187 static inline int arp_checkentry(const struct arpt_arp *arp)
189 if (arp->flags & ~ARPT_F_MASK) {
190 duprintf("Unknown flag bits set: %08X\n",
191 arp->flags & ~ARPT_F_MASK);
194 if (arp->invflags & ~ARPT_INV_MASK) {
195 duprintf("Unknown invflag bits set: %08X\n",
196 arp->invflags & ~ARPT_INV_MASK);
204 arpt_error(struct sk_buff *skb, const struct xt_target_param *par)
207 printk("arp_tables: error: '%s'\n",
208 (const char *)par->targinfo);
213 static inline struct arpt_entry *get_entry(void *base, unsigned int offset)
215 return (struct arpt_entry *)(base + offset);
218 unsigned int arpt_do_table(struct sk_buff *skb,
220 const struct net_device *in,
221 const struct net_device *out,
222 struct xt_table *table)
224 static const char nulldevname[IFNAMSIZ];
225 unsigned int verdict = NF_DROP;
226 const struct arphdr *arp;
227 bool hotdrop = false;
228 struct arpt_entry *e, *back;
229 const char *indev, *outdev;
231 const struct xt_table_info *private;
232 struct xt_target_param tgpar;
234 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
237 indev = in ? in->name : nulldevname;
238 outdev = out ? out->name : nulldevname;
240 read_lock_bh(&table->lock);
241 private = table->private;
242 table_base = (void *)private->entries[smp_processor_id()];
243 e = get_entry(table_base, private->hook_entry[hook]);
244 back = get_entry(table_base, private->underflow[hook]);
248 tgpar.hooknum = hook;
252 if (arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
253 struct arpt_entry_target *t;
256 hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
257 (2 * skb->dev->addr_len);
258 ADD_COUNTER(e->counters, hdr_len, 1);
260 t = arpt_get_target(e);
262 /* Standard target? */
263 if (!t->u.kernel.target->target) {
266 v = ((struct arpt_standard_target *)t)->verdict;
268 /* Pop from stack? */
269 if (v != ARPT_RETURN) {
270 verdict = (unsigned)(-v) - 1;
274 back = get_entry(table_base,
279 != (void *)e + e->next_offset) {
280 /* Save old back ptr in next entry */
281 struct arpt_entry *next
282 = (void *)e + e->next_offset;
284 (void *)back - table_base;
286 /* set back pointer to next entry */
290 e = get_entry(table_base, v);
292 /* Targets which reenter must return
295 tgpar.target = t->u.kernel.target;
296 tgpar.targinfo = t->data;
297 verdict = t->u.kernel.target->target(skb,
300 /* Target might have changed stuff. */
303 if (verdict == ARPT_CONTINUE)
304 e = (void *)e + e->next_offset;
310 e = (void *)e + e->next_offset;
313 read_unlock_bh(&table->lock);
321 /* All zeroes == unconditional rule. */
322 static inline int unconditional(const struct arpt_arp *arp)
326 for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
327 if (((__u32 *)arp)[i])
333 /* Figures out from what hook each rule can be called: returns 0 if
334 * there are loops. Puts hook bitmask in comefrom.
336 static int mark_source_chains(struct xt_table_info *newinfo,
337 unsigned int valid_hooks, void *entry0)
341 /* No recursion; use packet counter to save back ptrs (reset
342 * to 0 as we leave), and comefrom to save source hook bitmask.
344 for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
345 unsigned int pos = newinfo->hook_entry[hook];
347 = (struct arpt_entry *)(entry0 + pos);
349 if (!(valid_hooks & (1 << hook)))
352 /* Set initial back pointer. */
353 e->counters.pcnt = pos;
356 const struct arpt_standard_target *t
357 = (void *)arpt_get_target(e);
358 int visited = e->comefrom & (1 << hook);
360 if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
361 printk("arptables: loop hook %u pos %u %08X.\n",
362 hook, pos, e->comefrom);
366 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
368 /* Unconditional return/END. */
369 if ((e->target_offset == sizeof(struct arpt_entry)
370 && (strcmp(t->target.u.user.name,
371 ARPT_STANDARD_TARGET) == 0)
373 && unconditional(&e->arp)) || visited) {
374 unsigned int oldpos, size;
376 if (t->verdict < -NF_MAX_VERDICT - 1) {
377 duprintf("mark_source_chains: bad "
378 "negative verdict (%i)\n",
383 /* Return: backtrack through the last
387 e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
389 pos = e->counters.pcnt;
390 e->counters.pcnt = 0;
392 /* We're at the start. */
396 e = (struct arpt_entry *)
398 } while (oldpos == pos + e->next_offset);
401 size = e->next_offset;
402 e = (struct arpt_entry *)
403 (entry0 + pos + size);
404 e->counters.pcnt = pos;
407 int newpos = t->verdict;
409 if (strcmp(t->target.u.user.name,
410 ARPT_STANDARD_TARGET) == 0
412 if (newpos > newinfo->size -
413 sizeof(struct arpt_entry)) {
414 duprintf("mark_source_chains: "
415 "bad verdict (%i)\n",
420 /* This a jump; chase it. */
421 duprintf("Jump rule %u -> %u\n",
424 /* ... this is a fallthru */
425 newpos = pos + e->next_offset;
427 e = (struct arpt_entry *)
429 e->counters.pcnt = pos;
434 duprintf("Finished chain %u\n", hook);
439 static inline int check_entry(struct arpt_entry *e, const char *name)
441 const struct arpt_entry_target *t;
443 if (!arp_checkentry(&e->arp)) {
444 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
448 if (e->target_offset + sizeof(struct arpt_entry_target) > e->next_offset)
451 t = arpt_get_target(e);
452 if (e->target_offset + t->u.target_size > e->next_offset)
458 static inline int check_target(struct arpt_entry *e, const char *name)
460 struct arpt_entry_target *t = arpt_get_target(e);
462 struct xt_tgchk_param par = {
465 .target = t->u.kernel.target,
467 .hook_mask = e->comefrom,
470 ret = xt_check_target(&par, NFPROTO_ARP,
471 t->u.target_size - sizeof(*t), 0, false);
473 duprintf("arp_tables: check failed for `%s'.\n",
474 t->u.kernel.target->name);
481 find_check_entry(struct arpt_entry *e, const char *name, unsigned int size,
484 struct arpt_entry_target *t;
485 struct xt_target *target;
488 ret = check_entry(e, name);
492 t = arpt_get_target(e);
493 target = try_then_request_module(xt_find_target(NFPROTO_ARP,
496 "arpt_%s", t->u.user.name);
497 if (IS_ERR(target) || !target) {
498 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
499 ret = target ? PTR_ERR(target) : -ENOENT;
502 t->u.kernel.target = target;
504 ret = check_target(e, name);
511 module_put(t->u.kernel.target->me);
516 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
517 struct xt_table_info *newinfo,
519 unsigned char *limit,
520 const unsigned int *hook_entries,
521 const unsigned int *underflows,
526 if ((unsigned long)e % __alignof__(struct arpt_entry) != 0
527 || (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
528 duprintf("Bad offset %p\n", e);
533 < sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) {
534 duprintf("checking: element %p size %u\n",
539 /* Check hooks & underflows */
540 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
541 if ((unsigned char *)e - base == hook_entries[h])
542 newinfo->hook_entry[h] = hook_entries[h];
543 if ((unsigned char *)e - base == underflows[h])
544 newinfo->underflow[h] = underflows[h];
547 /* FIXME: underflows must be unconditional, standard verdicts
548 < 0 (not ARPT_RETURN). --RR */
550 /* Clear counters and comefrom */
551 e->counters = ((struct xt_counters) { 0, 0 });
558 static inline int cleanup_entry(struct arpt_entry *e, unsigned int *i)
560 struct arpt_entry_target *t;
562 if (i && (*i)-- == 0)
565 t = arpt_get_target(e);
566 if (t->u.kernel.target->destroy)
567 t->u.kernel.target->destroy(t->u.kernel.target, t->data);
568 module_put(t->u.kernel.target->me);
572 /* Checks and translates the user-supplied table segment (held in
575 static int translate_table(const char *name,
576 unsigned int valid_hooks,
577 struct xt_table_info *newinfo,
581 const unsigned int *hook_entries,
582 const unsigned int *underflows)
587 newinfo->size = size;
588 newinfo->number = number;
590 /* Init all hooks to impossible value. */
591 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
592 newinfo->hook_entry[i] = 0xFFFFFFFF;
593 newinfo->underflow[i] = 0xFFFFFFFF;
596 duprintf("translate_table: size %u\n", newinfo->size);
599 /* Walk through entries, checking offsets. */
600 ret = ARPT_ENTRY_ITERATE(entry0, newinfo->size,
601 check_entry_size_and_hooks,
605 hook_entries, underflows, &i);
606 duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
611 duprintf("translate_table: %u not %u entries\n",
616 /* Check hooks all assigned */
617 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
618 /* Only hooks which are valid */
619 if (!(valid_hooks & (1 << i)))
621 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
622 duprintf("Invalid hook entry %u %u\n",
626 if (newinfo->underflow[i] == 0xFFFFFFFF) {
627 duprintf("Invalid underflow %u %u\n",
633 if (!mark_source_chains(newinfo, valid_hooks, entry0)) {
634 duprintf("Looping hook\n");
638 /* Finally, each sanity check must pass */
640 ret = ARPT_ENTRY_ITERATE(entry0, newinfo->size,
641 find_check_entry, name, size, &i);
644 ARPT_ENTRY_ITERATE(entry0, newinfo->size,
649 /* And one copy for every other CPU */
650 for_each_possible_cpu(i) {
651 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
652 memcpy(newinfo->entries[i], entry0, newinfo->size);
659 static inline int add_entry_to_counter(const struct arpt_entry *e,
660 struct xt_counters total[],
663 ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
669 static inline int set_entry_to_counter(const struct arpt_entry *e,
670 struct xt_counters total[],
673 SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
679 static void get_counters(const struct xt_table_info *t,
680 struct xt_counters counters[])
686 /* Instead of clearing (by a previous call to memset())
687 * the counters and using adds, we set the counters
688 * with data used by 'current' CPU
689 * We dont care about preemption here.
691 curcpu = raw_smp_processor_id();
694 ARPT_ENTRY_ITERATE(t->entries[curcpu],
696 set_entry_to_counter,
700 for_each_possible_cpu(cpu) {
704 ARPT_ENTRY_ITERATE(t->entries[cpu],
706 add_entry_to_counter,
712 static inline struct xt_counters *alloc_counters(struct xt_table *table)
714 unsigned int countersize;
715 struct xt_counters *counters;
716 const struct xt_table_info *private = table->private;
718 /* We need atomic snapshot of counters: rest doesn't change
719 * (other than comefrom, which userspace doesn't care
722 countersize = sizeof(struct xt_counters) * private->number;
723 counters = vmalloc_node(countersize, numa_node_id());
725 if (counters == NULL)
726 return ERR_PTR(-ENOMEM);
728 /* First, sum counters... */
729 write_lock_bh(&table->lock);
730 get_counters(private, counters);
731 write_unlock_bh(&table->lock);
736 static int copy_entries_to_user(unsigned int total_size,
737 struct xt_table *table,
738 void __user *userptr)
740 unsigned int off, num;
741 struct arpt_entry *e;
742 struct xt_counters *counters;
743 struct xt_table_info *private = table->private;
747 counters = alloc_counters(table);
748 if (IS_ERR(counters))
749 return PTR_ERR(counters);
751 loc_cpu_entry = private->entries[raw_smp_processor_id()];
752 /* ... then copy entire thing ... */
753 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
758 /* FIXME: use iterator macros --RR */
759 /* ... then go back and fix counters and names */
760 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
761 struct arpt_entry_target *t;
763 e = (struct arpt_entry *)(loc_cpu_entry + off);
764 if (copy_to_user(userptr + off
765 + offsetof(struct arpt_entry, counters),
767 sizeof(counters[num])) != 0) {
772 t = arpt_get_target(e);
773 if (copy_to_user(userptr + off + e->target_offset
774 + offsetof(struct arpt_entry_target,
776 t->u.kernel.target->name,
777 strlen(t->u.kernel.target->name)+1) != 0) {
789 static void compat_standard_from_user(void *dst, void *src)
791 int v = *(compat_int_t *)src;
794 v += xt_compat_calc_jump(NFPROTO_ARP, v);
795 memcpy(dst, &v, sizeof(v));
798 static int compat_standard_to_user(void __user *dst, void *src)
800 compat_int_t cv = *(int *)src;
803 cv -= xt_compat_calc_jump(NFPROTO_ARP, cv);
804 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
807 static int compat_calc_entry(struct arpt_entry *e,
808 const struct xt_table_info *info,
809 void *base, struct xt_table_info *newinfo)
811 struct arpt_entry_target *t;
812 unsigned int entry_offset;
815 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
816 entry_offset = (void *)e - base;
818 t = arpt_get_target(e);
819 off += xt_compat_target_offset(t->u.kernel.target);
820 newinfo->size -= off;
821 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
825 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
826 if (info->hook_entry[i] &&
827 (e < (struct arpt_entry *)(base + info->hook_entry[i])))
828 newinfo->hook_entry[i] -= off;
829 if (info->underflow[i] &&
830 (e < (struct arpt_entry *)(base + info->underflow[i])))
831 newinfo->underflow[i] -= off;
836 static int compat_table_info(const struct xt_table_info *info,
837 struct xt_table_info *newinfo)
841 if (!newinfo || !info)
844 /* we dont care about newinfo->entries[] */
845 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
846 newinfo->initial_entries = 0;
847 loc_cpu_entry = info->entries[raw_smp_processor_id()];
848 return ARPT_ENTRY_ITERATE(loc_cpu_entry, info->size,
849 compat_calc_entry, info, loc_cpu_entry,
854 static int get_info(struct net *net, void __user *user, int *len, int compat)
856 char name[ARPT_TABLE_MAXNAMELEN];
860 if (*len != sizeof(struct arpt_getinfo)) {
861 duprintf("length %u != %Zu\n", *len,
862 sizeof(struct arpt_getinfo));
866 if (copy_from_user(name, user, sizeof(name)) != 0)
869 name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
872 xt_compat_lock(NFPROTO_ARP);
874 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
875 "arptable_%s", name);
876 if (t && !IS_ERR(t)) {
877 struct arpt_getinfo info;
878 const struct xt_table_info *private = t->private;
882 struct xt_table_info tmp;
883 ret = compat_table_info(private, &tmp);
884 xt_compat_flush_offsets(NFPROTO_ARP);
888 info.valid_hooks = t->valid_hooks;
889 memcpy(info.hook_entry, private->hook_entry,
890 sizeof(info.hook_entry));
891 memcpy(info.underflow, private->underflow,
892 sizeof(info.underflow));
893 info.num_entries = private->number;
894 info.size = private->size;
895 strcpy(info.name, name);
897 if (copy_to_user(user, &info, *len) != 0)
904 ret = t ? PTR_ERR(t) : -ENOENT;
907 xt_compat_unlock(NFPROTO_ARP);
912 static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
916 struct arpt_get_entries get;
919 if (*len < sizeof(get)) {
920 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
923 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
925 if (*len != sizeof(struct arpt_get_entries) + get.size) {
926 duprintf("get_entries: %u != %Zu\n", *len,
927 sizeof(struct arpt_get_entries) + get.size);
931 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
932 if (t && !IS_ERR(t)) {
933 const struct xt_table_info *private = t->private;
935 duprintf("t->private->number = %u\n",
937 if (get.size == private->size)
938 ret = copy_entries_to_user(private->size,
939 t, uptr->entrytable);
941 duprintf("get_entries: I've got %u not %u!\n",
942 private->size, get.size);
948 ret = t ? PTR_ERR(t) : -ENOENT;
953 static int __do_replace(struct net *net, const char *name,
954 unsigned int valid_hooks,
955 struct xt_table_info *newinfo,
956 unsigned int num_counters,
957 void __user *counters_ptr)
961 struct xt_table_info *oldinfo;
962 struct xt_counters *counters;
963 void *loc_cpu_old_entry;
966 counters = vmalloc_node(num_counters * sizeof(struct xt_counters),
973 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
974 "arptable_%s", name);
975 if (!t || IS_ERR(t)) {
976 ret = t ? PTR_ERR(t) : -ENOENT;
977 goto free_newinfo_counters_untrans;
981 if (valid_hooks != t->valid_hooks) {
982 duprintf("Valid hook crap: %08X vs %08X\n",
983 valid_hooks, t->valid_hooks);
988 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
992 /* Update module usage count based on number of rules */
993 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
994 oldinfo->number, oldinfo->initial_entries, newinfo->number);
995 if ((oldinfo->number > oldinfo->initial_entries) ||
996 (newinfo->number <= oldinfo->initial_entries))
998 if ((oldinfo->number > oldinfo->initial_entries) &&
999 (newinfo->number <= oldinfo->initial_entries))
1002 /* Get the old counters. */
1003 get_counters(oldinfo, counters);
1004 /* Decrease module usage counts and free resource */
1005 loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1006 ARPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,
1009 xt_free_table_info(oldinfo);
1010 if (copy_to_user(counters_ptr, counters,
1011 sizeof(struct xt_counters) * num_counters) != 0)
1020 free_newinfo_counters_untrans:
1026 static int do_replace(struct net *net, void __user *user, unsigned int len)
1029 struct arpt_replace tmp;
1030 struct xt_table_info *newinfo;
1031 void *loc_cpu_entry;
1033 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1036 /* overflow check */
1037 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1040 newinfo = xt_alloc_table_info(tmp.size);
1044 /* choose the copy that is on our node/cpu */
1045 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1046 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1052 ret = translate_table(tmp.name, tmp.valid_hooks,
1053 newinfo, loc_cpu_entry, tmp.size, tmp.num_entries,
1054 tmp.hook_entry, tmp.underflow);
1058 duprintf("arp_tables: Translated table\n");
1060 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1061 tmp.num_counters, tmp.counters);
1063 goto free_newinfo_untrans;
1066 free_newinfo_untrans:
1067 ARPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
1069 xt_free_table_info(newinfo);
1073 /* We're lazy, and add to the first CPU; overflow works its fey magic
1074 * and everything is OK.
1076 static inline int add_counter_to_entry(struct arpt_entry *e,
1077 const struct xt_counters addme[],
1081 ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
1087 static int do_add_counters(struct net *net, void __user *user, unsigned int len,
1091 struct xt_counters_info tmp;
1092 struct xt_counters *paddc;
1093 unsigned int num_counters;
1098 const struct xt_table_info *private;
1100 void *loc_cpu_entry;
1101 #ifdef CONFIG_COMPAT
1102 struct compat_xt_counters_info compat_tmp;
1106 size = sizeof(struct compat_xt_counters_info);
1111 size = sizeof(struct xt_counters_info);
1114 if (copy_from_user(ptmp, user, size) != 0)
1117 #ifdef CONFIG_COMPAT
1119 num_counters = compat_tmp.num_counters;
1120 name = compat_tmp.name;
1124 num_counters = tmp.num_counters;
1128 if (len != size + num_counters * sizeof(struct xt_counters))
1131 paddc = vmalloc_node(len - size, numa_node_id());
1135 if (copy_from_user(paddc, user + size, len - size) != 0) {
1140 t = xt_find_table_lock(net, NFPROTO_ARP, name);
1141 if (!t || IS_ERR(t)) {
1142 ret = t ? PTR_ERR(t) : -ENOENT;
1146 write_lock_bh(&t->lock);
1147 private = t->private;
1148 if (private->number != num_counters) {
1150 goto unlock_up_free;
1154 /* Choose the copy that is on our node */
1155 loc_cpu_entry = private->entries[smp_processor_id()];
1156 ARPT_ENTRY_ITERATE(loc_cpu_entry,
1158 add_counter_to_entry,
1162 write_unlock_bh(&t->lock);
1171 #ifdef CONFIG_COMPAT
1173 compat_release_entry(struct compat_arpt_entry *e, unsigned int *i)
1175 struct arpt_entry_target *t;
1177 if (i && (*i)-- == 0)
1180 t = compat_arpt_get_target(e);
1181 module_put(t->u.kernel.target->me);
1186 check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
1187 struct xt_table_info *newinfo,
1189 unsigned char *base,
1190 unsigned char *limit,
1191 unsigned int *hook_entries,
1192 unsigned int *underflows,
1196 struct arpt_entry_target *t;
1197 struct xt_target *target;
1198 unsigned int entry_offset;
1201 duprintf("check_compat_entry_size_and_hooks %p\n", e);
1202 if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0
1203 || (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
1204 duprintf("Bad offset %p, limit = %p\n", e, limit);
1208 if (e->next_offset < sizeof(struct compat_arpt_entry) +
1209 sizeof(struct compat_xt_entry_target)) {
1210 duprintf("checking: element %p size %u\n",
1215 /* For purposes of check_entry casting the compat entry is fine */
1216 ret = check_entry((struct arpt_entry *)e, name);
1220 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1221 entry_offset = (void *)e - (void *)base;
1223 t = compat_arpt_get_target(e);
1224 target = try_then_request_module(xt_find_target(NFPROTO_ARP,
1226 t->u.user.revision),
1227 "arpt_%s", t->u.user.name);
1228 if (IS_ERR(target) || !target) {
1229 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1231 ret = target ? PTR_ERR(target) : -ENOENT;
1234 t->u.kernel.target = target;
1236 off += xt_compat_target_offset(target);
1238 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
1240 goto release_target;
1242 /* Check hooks & underflows */
1243 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1244 if ((unsigned char *)e - base == hook_entries[h])
1245 newinfo->hook_entry[h] = hook_entries[h];
1246 if ((unsigned char *)e - base == underflows[h])
1247 newinfo->underflow[h] = underflows[h];
1250 /* Clear counters and comefrom */
1251 memset(&e->counters, 0, sizeof(e->counters));
1258 module_put(t->u.kernel.target->me);
1264 compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
1265 unsigned int *size, const char *name,
1266 struct xt_table_info *newinfo, unsigned char *base)
1268 struct arpt_entry_target *t;
1269 struct xt_target *target;
1270 struct arpt_entry *de;
1271 unsigned int origsize;
1276 de = (struct arpt_entry *)*dstptr;
1277 memcpy(de, e, sizeof(struct arpt_entry));
1278 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1280 *dstptr += sizeof(struct arpt_entry);
1281 *size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1283 de->target_offset = e->target_offset - (origsize - *size);
1284 t = compat_arpt_get_target(e);
1285 target = t->u.kernel.target;
1286 xt_compat_target_from_user(t, dstptr, size);
1288 de->next_offset = e->next_offset - (origsize - *size);
1289 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1290 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1291 newinfo->hook_entry[h] -= origsize - *size;
1292 if ((unsigned char *)de - base < newinfo->underflow[h])
1293 newinfo->underflow[h] -= origsize - *size;
1298 static inline int compat_check_entry(struct arpt_entry *e, const char *name,
1303 ret = check_target(e, name);
1311 static int translate_compat_table(const char *name,
1312 unsigned int valid_hooks,
1313 struct xt_table_info **pinfo,
1315 unsigned int total_size,
1316 unsigned int number,
1317 unsigned int *hook_entries,
1318 unsigned int *underflows)
1321 struct xt_table_info *newinfo, *info;
1322 void *pos, *entry0, *entry1;
1329 info->number = number;
1331 /* Init all hooks to impossible value. */
1332 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1333 info->hook_entry[i] = 0xFFFFFFFF;
1334 info->underflow[i] = 0xFFFFFFFF;
1337 duprintf("translate_compat_table: size %u\n", info->size);
1339 xt_compat_lock(NFPROTO_ARP);
1340 /* Walk through entries, checking offsets. */
1341 ret = COMPAT_ARPT_ENTRY_ITERATE(entry0, total_size,
1342 check_compat_entry_size_and_hooks,
1343 info, &size, entry0,
1344 entry0 + total_size,
1345 hook_entries, underflows, &j, name);
1351 duprintf("translate_compat_table: %u not %u entries\n",
1356 /* Check hooks all assigned */
1357 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1358 /* Only hooks which are valid */
1359 if (!(valid_hooks & (1 << i)))
1361 if (info->hook_entry[i] == 0xFFFFFFFF) {
1362 duprintf("Invalid hook entry %u %u\n",
1363 i, hook_entries[i]);
1366 if (info->underflow[i] == 0xFFFFFFFF) {
1367 duprintf("Invalid underflow %u %u\n",
1374 newinfo = xt_alloc_table_info(size);
1378 newinfo->number = number;
1379 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1380 newinfo->hook_entry[i] = info->hook_entry[i];
1381 newinfo->underflow[i] = info->underflow[i];
1383 entry1 = newinfo->entries[raw_smp_processor_id()];
1386 ret = COMPAT_ARPT_ENTRY_ITERATE(entry0, total_size,
1387 compat_copy_entry_from_user,
1388 &pos, &size, name, newinfo, entry1);
1389 xt_compat_flush_offsets(NFPROTO_ARP);
1390 xt_compat_unlock(NFPROTO_ARP);
1395 if (!mark_source_chains(newinfo, valid_hooks, entry1))
1399 ret = ARPT_ENTRY_ITERATE(entry1, newinfo->size, compat_check_entry,
1403 COMPAT_ARPT_ENTRY_ITERATE_CONTINUE(entry0, newinfo->size, i,
1404 compat_release_entry, &j);
1405 ARPT_ENTRY_ITERATE(entry1, newinfo->size, cleanup_entry, &i);
1406 xt_free_table_info(newinfo);
1410 /* And one copy for every other CPU */
1411 for_each_possible_cpu(i)
1412 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1413 memcpy(newinfo->entries[i], entry1, newinfo->size);
1417 xt_free_table_info(info);
1421 xt_free_table_info(newinfo);
1423 COMPAT_ARPT_ENTRY_ITERATE(entry0, total_size, compat_release_entry, &j);
1426 xt_compat_flush_offsets(NFPROTO_ARP);
1427 xt_compat_unlock(NFPROTO_ARP);
1431 struct compat_arpt_replace {
1432 char name[ARPT_TABLE_MAXNAMELEN];
1436 u32 hook_entry[NF_ARP_NUMHOOKS];
1437 u32 underflow[NF_ARP_NUMHOOKS];
1439 compat_uptr_t counters;
1440 struct compat_arpt_entry entries[0];
1443 static int compat_do_replace(struct net *net, void __user *user,
1447 struct compat_arpt_replace tmp;
1448 struct xt_table_info *newinfo;
1449 void *loc_cpu_entry;
1451 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1454 /* overflow check */
1455 if (tmp.size >= INT_MAX / num_possible_cpus())
1457 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1460 newinfo = xt_alloc_table_info(tmp.size);
1464 /* choose the copy that is on our node/cpu */
1465 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1466 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) {
1471 ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1472 &newinfo, &loc_cpu_entry, tmp.size,
1473 tmp.num_entries, tmp.hook_entry,
1478 duprintf("compat_do_replace: Translated table\n");
1480 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1481 tmp.num_counters, compat_ptr(tmp.counters));
1483 goto free_newinfo_untrans;
1486 free_newinfo_untrans:
1487 ARPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
1489 xt_free_table_info(newinfo);
1493 static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user,
1498 if (!capable(CAP_NET_ADMIN))
1502 case ARPT_SO_SET_REPLACE:
1503 ret = compat_do_replace(sock_net(sk), user, len);
1506 case ARPT_SO_SET_ADD_COUNTERS:
1507 ret = do_add_counters(sock_net(sk), user, len, 1);
1511 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1518 static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr,
1519 compat_uint_t *size,
1520 struct xt_counters *counters,
1523 struct arpt_entry_target *t;
1524 struct compat_arpt_entry __user *ce;
1525 u_int16_t target_offset, next_offset;
1526 compat_uint_t origsize;
1531 ce = (struct compat_arpt_entry __user *)*dstptr;
1532 if (copy_to_user(ce, e, sizeof(struct arpt_entry)))
1535 if (copy_to_user(&ce->counters, &counters[*i], sizeof(counters[*i])))
1538 *dstptr += sizeof(struct compat_arpt_entry);
1539 *size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1541 target_offset = e->target_offset - (origsize - *size);
1543 t = arpt_get_target(e);
1544 ret = xt_compat_target_to_user(t, dstptr, size);
1548 next_offset = e->next_offset - (origsize - *size);
1549 if (put_user(target_offset, &ce->target_offset))
1551 if (put_user(next_offset, &ce->next_offset))
1560 static int compat_copy_entries_to_user(unsigned int total_size,
1561 struct xt_table *table,
1562 void __user *userptr)
1564 struct xt_counters *counters;
1565 const struct xt_table_info *private = table->private;
1569 void *loc_cpu_entry;
1572 counters = alloc_counters(table);
1573 if (IS_ERR(counters))
1574 return PTR_ERR(counters);
1576 /* choose the copy on our node/cpu */
1577 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1580 ret = ARPT_ENTRY_ITERATE(loc_cpu_entry, total_size,
1581 compat_copy_entry_to_user,
1582 &pos, &size, counters, &i);
1587 struct compat_arpt_get_entries {
1588 char name[ARPT_TABLE_MAXNAMELEN];
1590 struct compat_arpt_entry entrytable[0];
1593 static int compat_get_entries(struct net *net,
1594 struct compat_arpt_get_entries __user *uptr,
1598 struct compat_arpt_get_entries get;
1601 if (*len < sizeof(get)) {
1602 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1605 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1607 if (*len != sizeof(struct compat_arpt_get_entries) + get.size) {
1608 duprintf("compat_get_entries: %u != %zu\n",
1609 *len, sizeof(get) + get.size);
1613 xt_compat_lock(NFPROTO_ARP);
1614 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
1615 if (t && !IS_ERR(t)) {
1616 const struct xt_table_info *private = t->private;
1617 struct xt_table_info info;
1619 duprintf("t->private->number = %u\n", private->number);
1620 ret = compat_table_info(private, &info);
1621 if (!ret && get.size == info.size) {
1622 ret = compat_copy_entries_to_user(private->size,
1623 t, uptr->entrytable);
1625 duprintf("compat_get_entries: I've got %u not %u!\n",
1626 private->size, get.size);
1629 xt_compat_flush_offsets(NFPROTO_ARP);
1633 ret = t ? PTR_ERR(t) : -ENOENT;
1635 xt_compat_unlock(NFPROTO_ARP);
1639 static int do_arpt_get_ctl(struct sock *, int, void __user *, int *);
1641 static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user,
1646 if (!capable(CAP_NET_ADMIN))
1650 case ARPT_SO_GET_INFO:
1651 ret = get_info(sock_net(sk), user, len, 1);
1653 case ARPT_SO_GET_ENTRIES:
1654 ret = compat_get_entries(sock_net(sk), user, len);
1657 ret = do_arpt_get_ctl(sk, cmd, user, len);
1663 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1667 if (!capable(CAP_NET_ADMIN))
1671 case ARPT_SO_SET_REPLACE:
1672 ret = do_replace(sock_net(sk), user, len);
1675 case ARPT_SO_SET_ADD_COUNTERS:
1676 ret = do_add_counters(sock_net(sk), user, len, 0);
1680 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1687 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1691 if (!capable(CAP_NET_ADMIN))
1695 case ARPT_SO_GET_INFO:
1696 ret = get_info(sock_net(sk), user, len, 0);
1699 case ARPT_SO_GET_ENTRIES:
1700 ret = get_entries(sock_net(sk), user, len);
1703 case ARPT_SO_GET_REVISION_TARGET: {
1704 struct xt_get_revision rev;
1706 if (*len != sizeof(rev)) {
1710 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1715 try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name,
1716 rev.revision, 1, &ret),
1717 "arpt_%s", rev.name);
1722 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1729 struct xt_table *arpt_register_table(struct net *net, struct xt_table *table,
1730 const struct arpt_replace *repl)
1733 struct xt_table_info *newinfo;
1734 struct xt_table_info bootstrap
1735 = { 0, 0, 0, { 0 }, { 0 }, { } };
1736 void *loc_cpu_entry;
1737 struct xt_table *new_table;
1739 newinfo = xt_alloc_table_info(repl->size);
1745 /* choose the copy on our node/cpu */
1746 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1747 memcpy(loc_cpu_entry, repl->entries, repl->size);
1749 ret = translate_table(table->name, table->valid_hooks,
1750 newinfo, loc_cpu_entry, repl->size,
1755 duprintf("arpt_register_table: translate table gives %d\n", ret);
1759 new_table = xt_register_table(net, table, &bootstrap, newinfo);
1760 if (IS_ERR(new_table)) {
1761 ret = PTR_ERR(new_table);
1767 xt_free_table_info(newinfo);
1769 return ERR_PTR(ret);
1772 void arpt_unregister_table(struct xt_table *table)
1774 struct xt_table_info *private;
1775 void *loc_cpu_entry;
1776 struct module *table_owner = table->me;
1778 private = xt_unregister_table(table);
1780 /* Decrease module usage counts and free resources */
1781 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1782 ARPT_ENTRY_ITERATE(loc_cpu_entry, private->size,
1783 cleanup_entry, NULL);
1784 if (private->number > private->initial_entries)
1785 module_put(table_owner);
1786 xt_free_table_info(private);
1789 /* The built-in targets: standard (NULL) and error. */
1790 static struct xt_target arpt_standard_target __read_mostly = {
1791 .name = ARPT_STANDARD_TARGET,
1792 .targetsize = sizeof(int),
1793 .family = NFPROTO_ARP,
1794 #ifdef CONFIG_COMPAT
1795 .compatsize = sizeof(compat_int_t),
1796 .compat_from_user = compat_standard_from_user,
1797 .compat_to_user = compat_standard_to_user,
1801 static struct xt_target arpt_error_target __read_mostly = {
1802 .name = ARPT_ERROR_TARGET,
1803 .target = arpt_error,
1804 .targetsize = ARPT_FUNCTION_MAXNAMELEN,
1805 .family = NFPROTO_ARP,
1808 static struct nf_sockopt_ops arpt_sockopts = {
1810 .set_optmin = ARPT_BASE_CTL,
1811 .set_optmax = ARPT_SO_SET_MAX+1,
1812 .set = do_arpt_set_ctl,
1813 #ifdef CONFIG_COMPAT
1814 .compat_set = compat_do_arpt_set_ctl,
1816 .get_optmin = ARPT_BASE_CTL,
1817 .get_optmax = ARPT_SO_GET_MAX+1,
1818 .get = do_arpt_get_ctl,
1819 #ifdef CONFIG_COMPAT
1820 .compat_get = compat_do_arpt_get_ctl,
1822 .owner = THIS_MODULE,
1825 static int __net_init arp_tables_net_init(struct net *net)
1827 return xt_proto_init(net, NFPROTO_ARP);
1830 static void __net_exit arp_tables_net_exit(struct net *net)
1832 xt_proto_fini(net, NFPROTO_ARP);
1835 static struct pernet_operations arp_tables_net_ops = {
1836 .init = arp_tables_net_init,
1837 .exit = arp_tables_net_exit,
1840 static int __init arp_tables_init(void)
1844 ret = register_pernet_subsys(&arp_tables_net_ops);
1848 /* Noone else will be downing sem now, so we won't sleep */
1849 ret = xt_register_target(&arpt_standard_target);
1852 ret = xt_register_target(&arpt_error_target);
1856 /* Register setsockopt */
1857 ret = nf_register_sockopt(&arpt_sockopts);
1861 printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n");
1865 xt_unregister_target(&arpt_error_target);
1867 xt_unregister_target(&arpt_standard_target);
1869 unregister_pernet_subsys(&arp_tables_net_ops);
1874 static void __exit arp_tables_fini(void)
1876 nf_unregister_sockopt(&arpt_sockopts);
1877 xt_unregister_target(&arpt_error_target);
1878 xt_unregister_target(&arpt_standard_target);
1879 unregister_pernet_subsys(&arp_tables_net_ops);
1882 EXPORT_SYMBOL(arpt_register_table);
1883 EXPORT_SYMBOL(arpt_unregister_table);
1884 EXPORT_SYMBOL(arpt_do_table);
1886 module_init(arp_tables_init);
1887 module_exit(arp_tables_fini);