2 * (C) 1999-2001 Paul `Rusty' Russell
3 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
4 * (C) 2011 Patrick McHardy <kaber@trash.net>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include <linux/timer.h>
14 #include <linux/skbuff.h>
15 #include <linux/gfp.h>
17 #include <linux/jhash.h>
18 #include <linux/rtnetlink.h>
20 #include <net/netfilter/nf_conntrack.h>
21 #include <net/netfilter/nf_conntrack_core.h>
22 #include <net/netfilter/nf_nat.h>
23 #include <net/netfilter/nf_nat_l3proto.h>
24 #include <net/netfilter/nf_nat_l4proto.h>
25 #include <net/netfilter/nf_nat_core.h>
26 #include <net/netfilter/nf_nat_helper.h>
27 #include <net/netfilter/nf_conntrack_helper.h>
28 #include <net/netfilter/nf_conntrack_seqadj.h>
29 #include <net/netfilter/nf_conntrack_l3proto.h>
30 #include <net/netfilter/nf_conntrack_zones.h>
31 #include <linux/netfilter/nf_nat.h>
33 static DEFINE_SPINLOCK(nf_nat_lock);
35 static DEFINE_MUTEX(nf_nat_proto_mutex);
36 static const struct nf_nat_l3proto __rcu *nf_nat_l3protos[NFPROTO_NUMPROTO]
38 static const struct nf_nat_l4proto __rcu **nf_nat_l4protos[NFPROTO_NUMPROTO]
42 inline const struct nf_nat_l3proto *
43 __nf_nat_l3proto_find(u8 family)
45 return rcu_dereference(nf_nat_l3protos[family]);
48 inline const struct nf_nat_l4proto *
49 __nf_nat_l4proto_find(u8 family, u8 protonum)
51 return rcu_dereference(nf_nat_l4protos[family][protonum]);
53 EXPORT_SYMBOL_GPL(__nf_nat_l4proto_find);
56 static void __nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl)
58 const struct nf_nat_l3proto *l3proto;
59 const struct nf_conn *ct;
60 enum ip_conntrack_info ctinfo;
61 enum ip_conntrack_dir dir;
62 unsigned long statusbit;
65 ct = nf_ct_get(skb, &ctinfo);
69 family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
71 l3proto = __nf_nat_l3proto_find(family);
75 dir = CTINFO2DIR(ctinfo);
76 if (dir == IP_CT_DIR_ORIGINAL)
77 statusbit = IPS_DST_NAT;
79 statusbit = IPS_SRC_NAT;
81 l3proto->decode_session(skb, ct, dir, statusbit, fl);
86 int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family)
90 struct dst_entry *dst;
93 err = xfrm_decode_session(skb, &fl, family);
99 dst = ((struct xfrm_dst *)dst)->route;
102 dst = xfrm_lookup(net, dst, &fl, skb->sk, 0);
107 skb_dst_set(skb, dst);
109 /* Change in oif may mean change in hh_len. */
110 hh_len = skb_dst(skb)->dev->hard_header_len;
111 if (skb_headroom(skb) < hh_len &&
112 pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
116 EXPORT_SYMBOL(nf_xfrm_me_harder);
117 #endif /* CONFIG_XFRM */
119 /* We keep an extra hash for each conntrack, for fast searching. */
120 static inline unsigned int
121 hash_by_src(const struct net *net, const struct nf_conntrack_tuple *tuple)
125 /* Original src, to ensure we map it consistently if poss. */
126 hash = jhash2((u32 *)&tuple->src, sizeof(tuple->src) / sizeof(u32),
127 tuple->dst.protonum ^ nf_conntrack_hash_rnd);
129 return reciprocal_scale(hash, net->ct.nat_htable_size);
132 /* Is this tuple already taken? (not by us) */
134 nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
135 const struct nf_conn *ignored_conntrack)
137 /* Conntrack tracking doesn't keep track of outgoing tuples; only
138 * incoming ones. NAT means they don't have a fixed mapping,
139 * so we invert the tuple and look for the incoming reply.
141 * We could keep a separate hash if this proves too slow.
143 struct nf_conntrack_tuple reply;
145 nf_ct_invert_tuplepr(&reply, tuple);
146 return nf_conntrack_tuple_taken(&reply, ignored_conntrack);
148 EXPORT_SYMBOL(nf_nat_used_tuple);
150 /* If we source map this tuple so reply looks like reply_tuple, will
151 * that meet the constraints of range.
153 static int in_range(const struct nf_nat_l3proto *l3proto,
154 const struct nf_nat_l4proto *l4proto,
155 const struct nf_conntrack_tuple *tuple,
156 const struct nf_nat_range *range)
158 /* If we are supposed to map IPs, then we must be in the
159 * range specified, otherwise let this drag us onto a new src IP.
161 if (range->flags & NF_NAT_RANGE_MAP_IPS &&
162 !l3proto->in_range(tuple, range))
165 if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) ||
166 l4proto->in_range(tuple, NF_NAT_MANIP_SRC,
167 &range->min_proto, &range->max_proto))
174 same_src(const struct nf_conn *ct,
175 const struct nf_conntrack_tuple *tuple)
177 const struct nf_conntrack_tuple *t;
179 t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
180 return (t->dst.protonum == tuple->dst.protonum &&
181 nf_inet_addr_cmp(&t->src.u3, &tuple->src.u3) &&
182 t->src.u.all == tuple->src.u.all);
185 /* Only called for SRC manip */
187 find_appropriate_src(struct net *net,
188 const struct nf_conntrack_zone *zone,
189 const struct nf_nat_l3proto *l3proto,
190 const struct nf_nat_l4proto *l4proto,
191 const struct nf_conntrack_tuple *tuple,
192 struct nf_conntrack_tuple *result,
193 const struct nf_nat_range *range)
195 unsigned int h = hash_by_src(net, tuple);
196 const struct nf_conn_nat *nat;
197 const struct nf_conn *ct;
199 hlist_for_each_entry_rcu(nat, &net->ct.nat_bysource[h], bysource) {
201 if (same_src(ct, tuple) &&
202 nf_ct_zone_equal(ct, zone, IP_CT_DIR_ORIGINAL)) {
203 /* Copy source part from reply tuple. */
204 nf_ct_invert_tuplepr(result,
205 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
206 result->dst = tuple->dst;
208 if (in_range(l3proto, l4proto, result, range))
215 /* For [FUTURE] fragmentation handling, we want the least-used
216 * src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus
217 * if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
218 * 1-65535, we don't do pro-rata allocation based on ports; we choose
219 * the ip with the lowest src-ip/dst-ip/proto usage.
222 find_best_ips_proto(const struct nf_conntrack_zone *zone,
223 struct nf_conntrack_tuple *tuple,
224 const struct nf_nat_range *range,
225 const struct nf_conn *ct,
226 enum nf_nat_manip_type maniptype)
228 union nf_inet_addr *var_ipp;
231 u32 minip, maxip, j, dist;
234 /* No IP mapping? Do nothing. */
235 if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
238 if (maniptype == NF_NAT_MANIP_SRC)
239 var_ipp = &tuple->src.u3;
241 var_ipp = &tuple->dst.u3;
243 /* Fast path: only one choice. */
244 if (nf_inet_addr_cmp(&range->min_addr, &range->max_addr)) {
245 *var_ipp = range->min_addr;
249 if (nf_ct_l3num(ct) == NFPROTO_IPV4)
250 max = sizeof(var_ipp->ip) / sizeof(u32) - 1;
252 max = sizeof(var_ipp->ip6) / sizeof(u32) - 1;
254 /* Hashing source and destination IPs gives a fairly even
255 * spread in practice (if there are a small number of IPs
256 * involved, there usually aren't that many connections
257 * anyway). The consistency means that servers see the same
258 * client coming from the same IP (some Internet Banking sites
259 * like this), even across reboots.
261 j = jhash2((u32 *)&tuple->src.u3, sizeof(tuple->src.u3) / sizeof(u32),
262 range->flags & NF_NAT_RANGE_PERSISTENT ?
263 0 : (__force u32)tuple->dst.u3.all[max] ^ zone->id);
266 for (i = 0; i <= max; i++) {
267 /* If first bytes of the address are at the maximum, use the
268 * distance. Otherwise use the full range.
271 minip = ntohl((__force __be32)range->min_addr.all[i]);
272 maxip = ntohl((__force __be32)range->max_addr.all[i]);
273 dist = maxip - minip + 1;
279 var_ipp->all[i] = (__force __u32)
280 htonl(minip + reciprocal_scale(j, dist));
281 if (var_ipp->all[i] != range->max_addr.all[i])
284 if (!(range->flags & NF_NAT_RANGE_PERSISTENT))
285 j ^= (__force u32)tuple->dst.u3.all[i];
289 /* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
290 * we change the source to map into the range. For NF_INET_PRE_ROUTING
291 * and NF_INET_LOCAL_OUT, we change the destination to map into the
292 * range. It might not be possible to get a unique tuple, but we try.
293 * At worst (or if we race), we will end up with a final duplicate in
294 * __ip_conntrack_confirm and drop the packet. */
296 get_unique_tuple(struct nf_conntrack_tuple *tuple,
297 const struct nf_conntrack_tuple *orig_tuple,
298 const struct nf_nat_range *range,
300 enum nf_nat_manip_type maniptype)
302 const struct nf_conntrack_zone *zone;
303 const struct nf_nat_l3proto *l3proto;
304 const struct nf_nat_l4proto *l4proto;
305 struct net *net = nf_ct_net(ct);
307 zone = nf_ct_zone(ct);
310 l3proto = __nf_nat_l3proto_find(orig_tuple->src.l3num);
311 l4proto = __nf_nat_l4proto_find(orig_tuple->src.l3num,
312 orig_tuple->dst.protonum);
314 /* 1) If this srcip/proto/src-proto-part is currently mapped,
315 * and that same mapping gives a unique tuple within the given
318 * This is only required for source (ie. NAT/masq) mappings.
319 * So far, we don't do local source mappings, so multiple
320 * manips not an issue.
322 if (maniptype == NF_NAT_MANIP_SRC &&
323 !(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
324 /* try the original tuple first */
325 if (in_range(l3proto, l4proto, orig_tuple, range)) {
326 if (!nf_nat_used_tuple(orig_tuple, ct)) {
327 *tuple = *orig_tuple;
330 } else if (find_appropriate_src(net, zone, l3proto, l4proto,
331 orig_tuple, tuple, range)) {
332 pr_debug("get_unique_tuple: Found current src map\n");
333 if (!nf_nat_used_tuple(tuple, ct))
338 /* 2) Select the least-used IP/proto combination in the given range */
339 *tuple = *orig_tuple;
340 find_best_ips_proto(zone, tuple, range, ct, maniptype);
342 /* 3) The per-protocol part of the manip is made to map into
343 * the range to make a unique tuple.
346 /* Only bother mapping if it's not already in range and unique */
347 if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
348 if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
349 if (l4proto->in_range(tuple, maniptype,
351 &range->max_proto) &&
352 (range->min_proto.all == range->max_proto.all ||
353 !nf_nat_used_tuple(tuple, ct)))
355 } else if (!nf_nat_used_tuple(tuple, ct)) {
360 /* Last change: get protocol to try to obtain unique tuple. */
361 l4proto->unique_tuple(l3proto, tuple, range, maniptype, ct);
366 struct nf_conn_nat *nf_ct_nat_ext_add(struct nf_conn *ct)
368 struct nf_conn_nat *nat = nfct_nat(ct);
372 if (!nf_ct_is_confirmed(ct))
373 nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
377 EXPORT_SYMBOL_GPL(nf_ct_nat_ext_add);
380 nf_nat_setup_info(struct nf_conn *ct,
381 const struct nf_nat_range *range,
382 enum nf_nat_manip_type maniptype)
384 struct net *net = nf_ct_net(ct);
385 struct nf_conntrack_tuple curr_tuple, new_tuple;
386 struct nf_conn_nat *nat;
388 /* nat helper or nfctnetlink also setup binding */
389 nat = nf_ct_nat_ext_add(ct);
393 NF_CT_ASSERT(maniptype == NF_NAT_MANIP_SRC ||
394 maniptype == NF_NAT_MANIP_DST);
395 BUG_ON(nf_nat_initialized(ct, maniptype));
397 /* What we've got will look like inverse of reply. Normally
398 * this is what is in the conntrack, except for prior
399 * manipulations (future optimization: if num_manips == 0,
400 * orig_tp = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple)
402 nf_ct_invert_tuplepr(&curr_tuple,
403 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
405 get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype);
407 if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) {
408 struct nf_conntrack_tuple reply;
410 /* Alter conntrack table so will recognize replies. */
411 nf_ct_invert_tuplepr(&reply, &new_tuple);
412 nf_conntrack_alter_reply(ct, &reply);
414 /* Non-atomic: we own this at the moment. */
415 if (maniptype == NF_NAT_MANIP_SRC)
416 ct->status |= IPS_SRC_NAT;
418 ct->status |= IPS_DST_NAT;
421 nfct_seqadj_ext_add(ct);
424 if (maniptype == NF_NAT_MANIP_SRC) {
425 unsigned int srchash;
427 srchash = hash_by_src(net,
428 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
429 spin_lock_bh(&nf_nat_lock);
430 /* nf_conntrack_alter_reply might re-allocate extension aera */
433 hlist_add_head_rcu(&nat->bysource,
434 &net->ct.nat_bysource[srchash]);
435 spin_unlock_bh(&nf_nat_lock);
439 if (maniptype == NF_NAT_MANIP_DST)
440 ct->status |= IPS_DST_NAT_DONE;
442 ct->status |= IPS_SRC_NAT_DONE;
446 EXPORT_SYMBOL(nf_nat_setup_info);
449 __nf_nat_alloc_null_binding(struct nf_conn *ct, enum nf_nat_manip_type manip)
451 /* Force range to this IP; let proto decide mapping for
452 * per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
453 * Use reply in case it's already been mangled (eg local packet).
455 union nf_inet_addr ip =
456 (manip == NF_NAT_MANIP_SRC ?
457 ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3 :
458 ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3);
459 struct nf_nat_range range = {
460 .flags = NF_NAT_RANGE_MAP_IPS,
464 return nf_nat_setup_info(ct, &range, manip);
468 nf_nat_alloc_null_binding(struct nf_conn *ct, unsigned int hooknum)
470 return __nf_nat_alloc_null_binding(ct, HOOK2MANIP(hooknum));
472 EXPORT_SYMBOL_GPL(nf_nat_alloc_null_binding);
474 /* Do packet manipulations according to nf_nat_setup_info. */
475 unsigned int nf_nat_packet(struct nf_conn *ct,
476 enum ip_conntrack_info ctinfo,
477 unsigned int hooknum,
480 const struct nf_nat_l3proto *l3proto;
481 const struct nf_nat_l4proto *l4proto;
482 enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
483 unsigned long statusbit;
484 enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum);
486 if (mtype == NF_NAT_MANIP_SRC)
487 statusbit = IPS_SRC_NAT;
489 statusbit = IPS_DST_NAT;
491 /* Invert if this is reply dir. */
492 if (dir == IP_CT_DIR_REPLY)
493 statusbit ^= IPS_NAT_MASK;
495 /* Non-atomic: these bits don't change. */
496 if (ct->status & statusbit) {
497 struct nf_conntrack_tuple target;
499 /* We are aiming to look like inverse of other direction. */
500 nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
502 l3proto = __nf_nat_l3proto_find(target.src.l3num);
503 l4proto = __nf_nat_l4proto_find(target.src.l3num,
504 target.dst.protonum);
505 if (!l3proto->manip_pkt(skb, 0, l4proto, &target, mtype))
510 EXPORT_SYMBOL_GPL(nf_nat_packet);
512 struct nf_nat_proto_clean {
517 /* kill conntracks with affected NAT section */
518 static int nf_nat_proto_remove(struct nf_conn *i, void *data)
520 const struct nf_nat_proto_clean *clean = data;
521 struct nf_conn_nat *nat = nfct_nat(i);
526 if ((clean->l3proto && nf_ct_l3num(i) != clean->l3proto) ||
527 (clean->l4proto && nf_ct_protonum(i) != clean->l4proto))
530 return i->status & IPS_NAT_MASK ? 1 : 0;
533 static int nf_nat_proto_clean(struct nf_conn *ct, void *data)
535 struct nf_conn_nat *nat = nfct_nat(ct);
537 if (nf_nat_proto_remove(ct, data))
540 if (!nat || !nat->ct)
543 /* This netns is being destroyed, and conntrack has nat null binding.
544 * Remove it from bysource hash, as the table will be freed soon.
546 * Else, when the conntrack is destoyed, nf_nat_cleanup_conntrack()
547 * will delete entry from already-freed table.
549 if (!del_timer(&ct->timeout))
552 spin_lock_bh(&nf_nat_lock);
553 hlist_del_rcu(&nat->bysource);
554 ct->status &= ~IPS_NAT_DONE_MASK;
556 spin_unlock_bh(&nf_nat_lock);
558 add_timer(&ct->timeout);
560 /* don't delete conntrack. Although that would make things a lot
561 * simpler, we'd end up flushing all conntracks on nat rmmod.
566 static void nf_nat_l4proto_clean(u8 l3proto, u8 l4proto)
568 struct nf_nat_proto_clean clean = {
576 nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean, 0, 0);
580 static void nf_nat_l3proto_clean(u8 l3proto)
582 struct nf_nat_proto_clean clean = {
590 nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean, 0, 0);
594 /* Protocol registration. */
595 int nf_nat_l4proto_register(u8 l3proto, const struct nf_nat_l4proto *l4proto)
597 const struct nf_nat_l4proto **l4protos;
601 mutex_lock(&nf_nat_proto_mutex);
602 if (nf_nat_l4protos[l3proto] == NULL) {
603 l4protos = kmalloc(IPPROTO_MAX * sizeof(struct nf_nat_l4proto *),
605 if (l4protos == NULL) {
610 for (i = 0; i < IPPROTO_MAX; i++)
611 RCU_INIT_POINTER(l4protos[i], &nf_nat_l4proto_unknown);
613 /* Before making proto_array visible to lockless readers,
614 * we must make sure its content is committed to memory.
618 nf_nat_l4protos[l3proto] = l4protos;
621 if (rcu_dereference_protected(
622 nf_nat_l4protos[l3proto][l4proto->l4proto],
623 lockdep_is_held(&nf_nat_proto_mutex)
624 ) != &nf_nat_l4proto_unknown) {
628 RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto], l4proto);
630 mutex_unlock(&nf_nat_proto_mutex);
633 EXPORT_SYMBOL_GPL(nf_nat_l4proto_register);
635 /* No one stores the protocol anywhere; simply delete it. */
636 void nf_nat_l4proto_unregister(u8 l3proto, const struct nf_nat_l4proto *l4proto)
638 mutex_lock(&nf_nat_proto_mutex);
639 RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto],
640 &nf_nat_l4proto_unknown);
641 mutex_unlock(&nf_nat_proto_mutex);
644 nf_nat_l4proto_clean(l3proto, l4proto->l4proto);
646 EXPORT_SYMBOL_GPL(nf_nat_l4proto_unregister);
648 int nf_nat_l3proto_register(const struct nf_nat_l3proto *l3proto)
652 err = nf_ct_l3proto_try_module_get(l3proto->l3proto);
656 mutex_lock(&nf_nat_proto_mutex);
657 RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_TCP],
658 &nf_nat_l4proto_tcp);
659 RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_UDP],
660 &nf_nat_l4proto_udp);
661 mutex_unlock(&nf_nat_proto_mutex);
663 RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], l3proto);
666 EXPORT_SYMBOL_GPL(nf_nat_l3proto_register);
668 void nf_nat_l3proto_unregister(const struct nf_nat_l3proto *l3proto)
670 mutex_lock(&nf_nat_proto_mutex);
671 RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], NULL);
672 mutex_unlock(&nf_nat_proto_mutex);
675 nf_nat_l3proto_clean(l3proto->l3proto);
676 nf_ct_l3proto_module_put(l3proto->l3proto);
678 EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister);
680 /* No one using conntrack by the time this called. */
681 static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
683 struct nf_conn_nat *nat = nf_ct_ext_find(ct, NF_CT_EXT_NAT);
685 if (nat == NULL || nat->ct == NULL)
688 NF_CT_ASSERT(nat->ct->status & IPS_SRC_NAT_DONE);
690 spin_lock_bh(&nf_nat_lock);
691 hlist_del_rcu(&nat->bysource);
692 spin_unlock_bh(&nf_nat_lock);
695 static void nf_nat_move_storage(void *new, void *old)
697 struct nf_conn_nat *new_nat = new;
698 struct nf_conn_nat *old_nat = old;
699 struct nf_conn *ct = old_nat->ct;
701 if (!ct || !(ct->status & IPS_SRC_NAT_DONE))
704 spin_lock_bh(&nf_nat_lock);
705 hlist_replace_rcu(&old_nat->bysource, &new_nat->bysource);
706 spin_unlock_bh(&nf_nat_lock);
709 static struct nf_ct_ext_type nat_extend __read_mostly = {
710 .len = sizeof(struct nf_conn_nat),
711 .align = __alignof__(struct nf_conn_nat),
712 .destroy = nf_nat_cleanup_conntrack,
713 .move = nf_nat_move_storage,
715 .flags = NF_CT_EXT_F_PREALLOC,
718 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
720 #include <linux/netfilter/nfnetlink.h>
721 #include <linux/netfilter/nfnetlink_conntrack.h>
723 static const struct nla_policy protonat_nla_policy[CTA_PROTONAT_MAX+1] = {
724 [CTA_PROTONAT_PORT_MIN] = { .type = NLA_U16 },
725 [CTA_PROTONAT_PORT_MAX] = { .type = NLA_U16 },
728 static int nfnetlink_parse_nat_proto(struct nlattr *attr,
729 const struct nf_conn *ct,
730 struct nf_nat_range *range)
732 struct nlattr *tb[CTA_PROTONAT_MAX+1];
733 const struct nf_nat_l4proto *l4proto;
736 err = nla_parse_nested(tb, CTA_PROTONAT_MAX, attr, protonat_nla_policy);
740 l4proto = __nf_nat_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
741 if (l4proto->nlattr_to_range)
742 err = l4proto->nlattr_to_range(tb, range);
747 static const struct nla_policy nat_nla_policy[CTA_NAT_MAX+1] = {
748 [CTA_NAT_V4_MINIP] = { .type = NLA_U32 },
749 [CTA_NAT_V4_MAXIP] = { .type = NLA_U32 },
750 [CTA_NAT_V6_MINIP] = { .len = sizeof(struct in6_addr) },
751 [CTA_NAT_V6_MAXIP] = { .len = sizeof(struct in6_addr) },
752 [CTA_NAT_PROTO] = { .type = NLA_NESTED },
756 nfnetlink_parse_nat(const struct nlattr *nat,
757 const struct nf_conn *ct, struct nf_nat_range *range,
758 const struct nf_nat_l3proto *l3proto)
760 struct nlattr *tb[CTA_NAT_MAX+1];
763 memset(range, 0, sizeof(*range));
765 err = nla_parse_nested(tb, CTA_NAT_MAX, nat, nat_nla_policy);
769 err = l3proto->nlattr_to_range(tb, range);
773 if (!tb[CTA_NAT_PROTO])
776 return nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO], ct, range);
779 /* This function is called under rcu_read_lock() */
781 nfnetlink_parse_nat_setup(struct nf_conn *ct,
782 enum nf_nat_manip_type manip,
783 const struct nlattr *attr)
785 struct nf_nat_range range;
786 const struct nf_nat_l3proto *l3proto;
789 /* Should not happen, restricted to creating new conntracks
792 if (WARN_ON_ONCE(nf_nat_initialized(ct, manip)))
795 /* Make sure that L3 NAT is there by when we call nf_nat_setup_info to
796 * attach the null binding, otherwise this may oops.
798 l3proto = __nf_nat_l3proto_find(nf_ct_l3num(ct));
802 /* No NAT information has been passed, allocate the null-binding */
804 return __nf_nat_alloc_null_binding(ct, manip);
806 err = nfnetlink_parse_nat(attr, ct, &range, l3proto);
810 return nf_nat_setup_info(ct, &range, manip);
814 nfnetlink_parse_nat_setup(struct nf_conn *ct,
815 enum nf_nat_manip_type manip,
816 const struct nlattr *attr)
822 static int __net_init nf_nat_net_init(struct net *net)
824 /* Leave them the same for the moment. */
825 net->ct.nat_htable_size = net->ct.htable_size;
826 net->ct.nat_bysource = nf_ct_alloc_hashtable(&net->ct.nat_htable_size, 0);
827 if (!net->ct.nat_bysource)
832 static void __net_exit nf_nat_net_exit(struct net *net)
834 struct nf_nat_proto_clean clean = {};
836 nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean, 0, 0);
838 nf_ct_free_hashtable(net->ct.nat_bysource, net->ct.nat_htable_size);
841 static struct pernet_operations nf_nat_net_ops = {
842 .init = nf_nat_net_init,
843 .exit = nf_nat_net_exit,
846 static struct nf_ct_helper_expectfn follow_master_nat = {
847 .name = "nat-follow-master",
848 .expectfn = nf_nat_follow_master,
851 static int __init nf_nat_init(void)
855 ret = nf_ct_extend_register(&nat_extend);
857 printk(KERN_ERR "nf_nat_core: Unable to register extension\n");
861 ret = register_pernet_subsys(&nf_nat_net_ops);
865 nf_ct_helper_expectfn_register(&follow_master_nat);
867 /* Initialize fake conntrack so that NAT will skip it */
868 nf_ct_untracked_status_or(IPS_NAT_DONE_MASK);
870 BUG_ON(nfnetlink_parse_nat_setup_hook != NULL);
871 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook,
872 nfnetlink_parse_nat_setup);
874 BUG_ON(nf_nat_decode_session_hook != NULL);
875 RCU_INIT_POINTER(nf_nat_decode_session_hook, __nf_nat_decode_session);
880 nf_ct_extend_unregister(&nat_extend);
884 static void __exit nf_nat_cleanup(void)
888 unregister_pernet_subsys(&nf_nat_net_ops);
889 nf_ct_extend_unregister(&nat_extend);
890 nf_ct_helper_expectfn_unregister(&follow_master_nat);
891 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook, NULL);
893 RCU_INIT_POINTER(nf_nat_decode_session_hook, NULL);
895 for (i = 0; i < NFPROTO_NUMPROTO; i++)
896 kfree(nf_nat_l4protos[i]);
900 MODULE_LICENSE("GPL");
902 module_init(nf_nat_init);
903 module_exit(nf_nat_cleanup);