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_MUTEX(nf_nat_proto_mutex);
34 static const struct nf_nat_l3proto __rcu *nf_nat_l3protos[NFPROTO_NUMPROTO]
36 static const struct nf_nat_l4proto __rcu **nf_nat_l4protos[NFPROTO_NUMPROTO]
39 struct nf_nat_conn_key {
40 const struct net *net;
41 const struct nf_conntrack_tuple *tuple;
42 const struct nf_conntrack_zone *zone;
45 static struct rhltable nf_nat_bysource_table;
47 inline const struct nf_nat_l3proto *
48 __nf_nat_l3proto_find(u8 family)
50 return rcu_dereference(nf_nat_l3protos[family]);
53 inline const struct nf_nat_l4proto *
54 __nf_nat_l4proto_find(u8 family, u8 protonum)
56 return rcu_dereference(nf_nat_l4protos[family][protonum]);
58 EXPORT_SYMBOL_GPL(__nf_nat_l4proto_find);
61 static void __nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl)
63 const struct nf_nat_l3proto *l3proto;
64 const struct nf_conn *ct;
65 enum ip_conntrack_info ctinfo;
66 enum ip_conntrack_dir dir;
67 unsigned long statusbit;
70 ct = nf_ct_get(skb, &ctinfo);
74 family = nf_ct_l3num(ct);
75 l3proto = __nf_nat_l3proto_find(family);
79 dir = CTINFO2DIR(ctinfo);
80 if (dir == IP_CT_DIR_ORIGINAL)
81 statusbit = IPS_DST_NAT;
83 statusbit = IPS_SRC_NAT;
85 l3proto->decode_session(skb, ct, dir, statusbit, fl);
88 int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family)
92 struct dst_entry *dst;
95 err = xfrm_decode_session(skb, &fl, family);
101 dst = ((struct xfrm_dst *)dst)->route;
104 dst = xfrm_lookup(net, dst, &fl, skb->sk, 0);
109 skb_dst_set(skb, dst);
111 /* Change in oif may mean change in hh_len. */
112 hh_len = skb_dst(skb)->dev->hard_header_len;
113 if (skb_headroom(skb) < hh_len &&
114 pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
118 EXPORT_SYMBOL(nf_xfrm_me_harder);
119 #endif /* CONFIG_XFRM */
121 static u32 nf_nat_bysource_hash(const void *data, u32 len, u32 seed)
123 const struct nf_conntrack_tuple *t;
124 const struct nf_conn *ct = data;
126 t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
127 /* Original src, to ensure we map it consistently if poss. */
129 seed ^= net_hash_mix(nf_ct_net(ct));
130 return jhash2((const u32 *)&t->src, sizeof(t->src) / sizeof(u32),
131 t->dst.protonum ^ seed);
134 /* Is this tuple already taken? (not by us) */
136 nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
137 const struct nf_conn *ignored_conntrack)
139 /* Conntrack tracking doesn't keep track of outgoing tuples; only
140 * incoming ones. NAT means they don't have a fixed mapping,
141 * so we invert the tuple and look for the incoming reply.
143 * We could keep a separate hash if this proves too slow.
145 struct nf_conntrack_tuple reply;
147 nf_ct_invert_tuplepr(&reply, tuple);
148 return nf_conntrack_tuple_taken(&reply, ignored_conntrack);
150 EXPORT_SYMBOL(nf_nat_used_tuple);
152 /* If we source map this tuple so reply looks like reply_tuple, will
153 * that meet the constraints of range.
155 static int in_range(const struct nf_nat_l3proto *l3proto,
156 const struct nf_nat_l4proto *l4proto,
157 const struct nf_conntrack_tuple *tuple,
158 const struct nf_nat_range *range)
160 /* If we are supposed to map IPs, then we must be in the
161 * range specified, otherwise let this drag us onto a new src IP.
163 if (range->flags & NF_NAT_RANGE_MAP_IPS &&
164 !l3proto->in_range(tuple, range))
167 if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) ||
168 l4proto->in_range(tuple, NF_NAT_MANIP_SRC,
169 &range->min_proto, &range->max_proto))
176 same_src(const struct nf_conn *ct,
177 const struct nf_conntrack_tuple *tuple)
179 const struct nf_conntrack_tuple *t;
181 t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
182 return (t->dst.protonum == tuple->dst.protonum &&
183 nf_inet_addr_cmp(&t->src.u3, &tuple->src.u3) &&
184 t->src.u.all == tuple->src.u.all);
187 static int nf_nat_bysource_cmp(struct rhashtable_compare_arg *arg,
190 const struct nf_nat_conn_key *key = arg->key;
191 const struct nf_conn *ct = obj;
193 if (!same_src(ct, key->tuple) ||
194 !net_eq(nf_ct_net(ct), key->net) ||
195 !nf_ct_zone_equal(ct, key->zone, IP_CT_DIR_ORIGINAL))
201 static struct rhashtable_params nf_nat_bysource_params = {
202 .head_offset = offsetof(struct nf_conn, nat_bysource),
203 .obj_hashfn = nf_nat_bysource_hash,
204 .obj_cmpfn = nf_nat_bysource_cmp,
209 /* Only called for SRC manip */
211 find_appropriate_src(struct net *net,
212 const struct nf_conntrack_zone *zone,
213 const struct nf_nat_l3proto *l3proto,
214 const struct nf_nat_l4proto *l4proto,
215 const struct nf_conntrack_tuple *tuple,
216 struct nf_conntrack_tuple *result,
217 const struct nf_nat_range *range)
219 const struct nf_conn *ct;
220 struct nf_nat_conn_key key = {
225 struct rhlist_head *hl;
227 hl = rhltable_lookup(&nf_nat_bysource_table, &key,
228 nf_nat_bysource_params);
232 ct = container_of(hl, typeof(*ct), nat_bysource);
234 nf_ct_invert_tuplepr(result,
235 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
236 result->dst = tuple->dst;
238 return in_range(l3proto, l4proto, result, range);
241 /* For [FUTURE] fragmentation handling, we want the least-used
242 * src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus
243 * if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
244 * 1-65535, we don't do pro-rata allocation based on ports; we choose
245 * the ip with the lowest src-ip/dst-ip/proto usage.
248 find_best_ips_proto(const struct nf_conntrack_zone *zone,
249 struct nf_conntrack_tuple *tuple,
250 const struct nf_nat_range *range,
251 const struct nf_conn *ct,
252 enum nf_nat_manip_type maniptype)
254 union nf_inet_addr *var_ipp;
257 u32 minip, maxip, j, dist;
260 /* No IP mapping? Do nothing. */
261 if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
264 if (maniptype == NF_NAT_MANIP_SRC)
265 var_ipp = &tuple->src.u3;
267 var_ipp = &tuple->dst.u3;
269 /* Fast path: only one choice. */
270 if (nf_inet_addr_cmp(&range->min_addr, &range->max_addr)) {
271 *var_ipp = range->min_addr;
275 if (nf_ct_l3num(ct) == NFPROTO_IPV4)
276 max = sizeof(var_ipp->ip) / sizeof(u32) - 1;
278 max = sizeof(var_ipp->ip6) / sizeof(u32) - 1;
280 /* Hashing source and destination IPs gives a fairly even
281 * spread in practice (if there are a small number of IPs
282 * involved, there usually aren't that many connections
283 * anyway). The consistency means that servers see the same
284 * client coming from the same IP (some Internet Banking sites
285 * like this), even across reboots.
287 j = jhash2((u32 *)&tuple->src.u3, sizeof(tuple->src.u3) / sizeof(u32),
288 range->flags & NF_NAT_RANGE_PERSISTENT ?
289 0 : (__force u32)tuple->dst.u3.all[max] ^ zone->id);
292 for (i = 0; i <= max; i++) {
293 /* If first bytes of the address are at the maximum, use the
294 * distance. Otherwise use the full range.
297 minip = ntohl((__force __be32)range->min_addr.all[i]);
298 maxip = ntohl((__force __be32)range->max_addr.all[i]);
299 dist = maxip - minip + 1;
305 var_ipp->all[i] = (__force __u32)
306 htonl(minip + reciprocal_scale(j, dist));
307 if (var_ipp->all[i] != range->max_addr.all[i])
310 if (!(range->flags & NF_NAT_RANGE_PERSISTENT))
311 j ^= (__force u32)tuple->dst.u3.all[i];
315 /* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
316 * we change the source to map into the range. For NF_INET_PRE_ROUTING
317 * and NF_INET_LOCAL_OUT, we change the destination to map into the
318 * range. It might not be possible to get a unique tuple, but we try.
319 * At worst (or if we race), we will end up with a final duplicate in
320 * __ip_conntrack_confirm and drop the packet. */
322 get_unique_tuple(struct nf_conntrack_tuple *tuple,
323 const struct nf_conntrack_tuple *orig_tuple,
324 const struct nf_nat_range *range,
326 enum nf_nat_manip_type maniptype)
328 const struct nf_conntrack_zone *zone;
329 const struct nf_nat_l3proto *l3proto;
330 const struct nf_nat_l4proto *l4proto;
331 struct net *net = nf_ct_net(ct);
333 zone = nf_ct_zone(ct);
336 l3proto = __nf_nat_l3proto_find(orig_tuple->src.l3num);
337 l4proto = __nf_nat_l4proto_find(orig_tuple->src.l3num,
338 orig_tuple->dst.protonum);
340 /* 1) If this srcip/proto/src-proto-part is currently mapped,
341 * and that same mapping gives a unique tuple within the given
344 * This is only required for source (ie. NAT/masq) mappings.
345 * So far, we don't do local source mappings, so multiple
346 * manips not an issue.
348 if (maniptype == NF_NAT_MANIP_SRC &&
349 !(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
350 /* try the original tuple first */
351 if (in_range(l3proto, l4proto, orig_tuple, range)) {
352 if (!nf_nat_used_tuple(orig_tuple, ct)) {
353 *tuple = *orig_tuple;
356 } else if (find_appropriate_src(net, zone, l3proto, l4proto,
357 orig_tuple, tuple, range)) {
358 pr_debug("get_unique_tuple: Found current src map\n");
359 if (!nf_nat_used_tuple(tuple, ct))
364 /* 2) Select the least-used IP/proto combination in the given range */
365 *tuple = *orig_tuple;
366 find_best_ips_proto(zone, tuple, range, ct, maniptype);
368 /* 3) The per-protocol part of the manip is made to map into
369 * the range to make a unique tuple.
372 /* Only bother mapping if it's not already in range and unique */
373 if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
374 if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
375 if (l4proto->in_range(tuple, maniptype,
377 &range->max_proto) &&
378 (range->min_proto.all == range->max_proto.all ||
379 !nf_nat_used_tuple(tuple, ct)))
381 } else if (!nf_nat_used_tuple(tuple, ct)) {
386 /* Last change: get protocol to try to obtain unique tuple. */
387 l4proto->unique_tuple(l3proto, tuple, range, maniptype, ct);
392 struct nf_conn_nat *nf_ct_nat_ext_add(struct nf_conn *ct)
394 struct nf_conn_nat *nat = nfct_nat(ct);
398 if (!nf_ct_is_confirmed(ct))
399 nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
403 EXPORT_SYMBOL_GPL(nf_ct_nat_ext_add);
406 nf_nat_setup_info(struct nf_conn *ct,
407 const struct nf_nat_range *range,
408 enum nf_nat_manip_type maniptype)
410 struct nf_conntrack_tuple curr_tuple, new_tuple;
412 NF_CT_ASSERT(maniptype == NF_NAT_MANIP_SRC ||
413 maniptype == NF_NAT_MANIP_DST);
414 BUG_ON(nf_nat_initialized(ct, maniptype));
416 /* What we've got will look like inverse of reply. Normally
417 * this is what is in the conntrack, except for prior
418 * manipulations (future optimization: if num_manips == 0,
419 * orig_tp = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple)
421 nf_ct_invert_tuplepr(&curr_tuple,
422 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
424 get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype);
426 if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) {
427 struct nf_conntrack_tuple reply;
429 /* Alter conntrack table so will recognize replies. */
430 nf_ct_invert_tuplepr(&reply, &new_tuple);
431 nf_conntrack_alter_reply(ct, &reply);
433 /* Non-atomic: we own this at the moment. */
434 if (maniptype == NF_NAT_MANIP_SRC)
435 ct->status |= IPS_SRC_NAT;
437 ct->status |= IPS_DST_NAT;
440 if (!nfct_seqadj_ext_add(ct))
444 if (maniptype == NF_NAT_MANIP_SRC) {
445 struct nf_nat_conn_key key = {
446 .net = nf_ct_net(ct),
447 .tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
448 .zone = nf_ct_zone(ct),
452 err = rhltable_insert_key(&nf_nat_bysource_table,
455 nf_nat_bysource_params);
461 if (maniptype == NF_NAT_MANIP_DST)
462 ct->status |= IPS_DST_NAT_DONE;
464 ct->status |= IPS_SRC_NAT_DONE;
468 EXPORT_SYMBOL(nf_nat_setup_info);
471 __nf_nat_alloc_null_binding(struct nf_conn *ct, enum nf_nat_manip_type manip)
473 /* Force range to this IP; let proto decide mapping for
474 * per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
475 * Use reply in case it's already been mangled (eg local packet).
477 union nf_inet_addr ip =
478 (manip == NF_NAT_MANIP_SRC ?
479 ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3 :
480 ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3);
481 struct nf_nat_range range = {
482 .flags = NF_NAT_RANGE_MAP_IPS,
486 return nf_nat_setup_info(ct, &range, manip);
490 nf_nat_alloc_null_binding(struct nf_conn *ct, unsigned int hooknum)
492 return __nf_nat_alloc_null_binding(ct, HOOK2MANIP(hooknum));
494 EXPORT_SYMBOL_GPL(nf_nat_alloc_null_binding);
496 /* Do packet manipulations according to nf_nat_setup_info. */
497 unsigned int nf_nat_packet(struct nf_conn *ct,
498 enum ip_conntrack_info ctinfo,
499 unsigned int hooknum,
502 const struct nf_nat_l3proto *l3proto;
503 const struct nf_nat_l4proto *l4proto;
504 enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
505 unsigned long statusbit;
506 enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum);
508 if (mtype == NF_NAT_MANIP_SRC)
509 statusbit = IPS_SRC_NAT;
511 statusbit = IPS_DST_NAT;
513 /* Invert if this is reply dir. */
514 if (dir == IP_CT_DIR_REPLY)
515 statusbit ^= IPS_NAT_MASK;
517 /* Non-atomic: these bits don't change. */
518 if (ct->status & statusbit) {
519 struct nf_conntrack_tuple target;
521 /* We are aiming to look like inverse of other direction. */
522 nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
524 l3proto = __nf_nat_l3proto_find(target.src.l3num);
525 l4proto = __nf_nat_l4proto_find(target.src.l3num,
526 target.dst.protonum);
527 if (!l3proto->manip_pkt(skb, 0, l4proto, &target, mtype))
532 EXPORT_SYMBOL_GPL(nf_nat_packet);
534 struct nf_nat_proto_clean {
539 /* kill conntracks with affected NAT section */
540 static int nf_nat_proto_remove(struct nf_conn *i, void *data)
542 const struct nf_nat_proto_clean *clean = data;
544 if ((clean->l3proto && nf_ct_l3num(i) != clean->l3proto) ||
545 (clean->l4proto && nf_ct_protonum(i) != clean->l4proto))
548 return i->status & IPS_NAT_MASK ? 1 : 0;
551 static int nf_nat_proto_clean(struct nf_conn *ct, void *data)
553 if (nf_nat_proto_remove(ct, data))
556 if ((ct->status & IPS_SRC_NAT_DONE) == 0)
559 /* This netns is being destroyed, and conntrack has nat null binding.
560 * Remove it from bysource hash, as the table will be freed soon.
562 * Else, when the conntrack is destoyed, nf_nat_cleanup_conntrack()
563 * will delete entry from already-freed table.
565 ct->status &= ~IPS_NAT_DONE_MASK;
566 rhltable_remove(&nf_nat_bysource_table, &ct->nat_bysource,
567 nf_nat_bysource_params);
569 /* don't delete conntrack. Although that would make things a lot
570 * simpler, we'd end up flushing all conntracks on nat rmmod.
575 static void nf_nat_l4proto_clean(u8 l3proto, u8 l4proto)
577 struct nf_nat_proto_clean clean = {
585 nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean, 0, 0);
589 static void nf_nat_l3proto_clean(u8 l3proto)
591 struct nf_nat_proto_clean clean = {
599 nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean, 0, 0);
603 /* Protocol registration. */
604 int nf_nat_l4proto_register(u8 l3proto, const struct nf_nat_l4proto *l4proto)
606 const struct nf_nat_l4proto **l4protos;
610 mutex_lock(&nf_nat_proto_mutex);
611 if (nf_nat_l4protos[l3proto] == NULL) {
612 l4protos = kmalloc(IPPROTO_MAX * sizeof(struct nf_nat_l4proto *),
614 if (l4protos == NULL) {
619 for (i = 0; i < IPPROTO_MAX; i++)
620 RCU_INIT_POINTER(l4protos[i], &nf_nat_l4proto_unknown);
622 /* Before making proto_array visible to lockless readers,
623 * we must make sure its content is committed to memory.
627 nf_nat_l4protos[l3proto] = l4protos;
630 if (rcu_dereference_protected(
631 nf_nat_l4protos[l3proto][l4proto->l4proto],
632 lockdep_is_held(&nf_nat_proto_mutex)
633 ) != &nf_nat_l4proto_unknown) {
637 RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto], l4proto);
639 mutex_unlock(&nf_nat_proto_mutex);
642 EXPORT_SYMBOL_GPL(nf_nat_l4proto_register);
644 /* No one stores the protocol anywhere; simply delete it. */
645 void nf_nat_l4proto_unregister(u8 l3proto, const struct nf_nat_l4proto *l4proto)
647 mutex_lock(&nf_nat_proto_mutex);
648 RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto],
649 &nf_nat_l4proto_unknown);
650 mutex_unlock(&nf_nat_proto_mutex);
653 nf_nat_l4proto_clean(l3proto, l4proto->l4proto);
655 EXPORT_SYMBOL_GPL(nf_nat_l4proto_unregister);
657 int nf_nat_l3proto_register(const struct nf_nat_l3proto *l3proto)
661 err = nf_ct_l3proto_try_module_get(l3proto->l3proto);
665 mutex_lock(&nf_nat_proto_mutex);
666 RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_TCP],
667 &nf_nat_l4proto_tcp);
668 RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_UDP],
669 &nf_nat_l4proto_udp);
670 #ifdef CONFIG_NF_NAT_PROTO_DCCP
671 RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_DCCP],
672 &nf_nat_l4proto_dccp);
674 #ifdef CONFIG_NF_NAT_PROTO_SCTP
675 RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_SCTP],
676 &nf_nat_l4proto_sctp);
678 #ifdef CONFIG_NF_NAT_PROTO_UDPLITE
679 RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_UDPLITE],
680 &nf_nat_l4proto_udplite);
682 mutex_unlock(&nf_nat_proto_mutex);
684 RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], l3proto);
687 EXPORT_SYMBOL_GPL(nf_nat_l3proto_register);
689 void nf_nat_l3proto_unregister(const struct nf_nat_l3proto *l3proto)
691 mutex_lock(&nf_nat_proto_mutex);
692 RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], NULL);
693 mutex_unlock(&nf_nat_proto_mutex);
696 nf_nat_l3proto_clean(l3proto->l3proto);
697 nf_ct_l3proto_module_put(l3proto->l3proto);
699 EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister);
701 /* No one using conntrack by the time this called. */
702 static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
704 if (ct->status & IPS_SRC_NAT_DONE)
705 rhltable_remove(&nf_nat_bysource_table, &ct->nat_bysource,
706 nf_nat_bysource_params);
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,
716 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
718 #include <linux/netfilter/nfnetlink.h>
719 #include <linux/netfilter/nfnetlink_conntrack.h>
721 static const struct nla_policy protonat_nla_policy[CTA_PROTONAT_MAX+1] = {
722 [CTA_PROTONAT_PORT_MIN] = { .type = NLA_U16 },
723 [CTA_PROTONAT_PORT_MAX] = { .type = NLA_U16 },
726 static int nfnetlink_parse_nat_proto(struct nlattr *attr,
727 const struct nf_conn *ct,
728 struct nf_nat_range *range)
730 struct nlattr *tb[CTA_PROTONAT_MAX+1];
731 const struct nf_nat_l4proto *l4proto;
734 err = nla_parse_nested(tb, CTA_PROTONAT_MAX, attr,
735 protonat_nla_policy, NULL);
739 l4proto = __nf_nat_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
740 if (l4proto->nlattr_to_range)
741 err = l4proto->nlattr_to_range(tb, range);
746 static const struct nla_policy nat_nla_policy[CTA_NAT_MAX+1] = {
747 [CTA_NAT_V4_MINIP] = { .type = NLA_U32 },
748 [CTA_NAT_V4_MAXIP] = { .type = NLA_U32 },
749 [CTA_NAT_V6_MINIP] = { .len = sizeof(struct in6_addr) },
750 [CTA_NAT_V6_MAXIP] = { .len = sizeof(struct in6_addr) },
751 [CTA_NAT_PROTO] = { .type = NLA_NESTED },
755 nfnetlink_parse_nat(const struct nlattr *nat,
756 const struct nf_conn *ct, struct nf_nat_range *range,
757 const struct nf_nat_l3proto *l3proto)
759 struct nlattr *tb[CTA_NAT_MAX+1];
762 memset(range, 0, sizeof(*range));
764 err = nla_parse_nested(tb, CTA_NAT_MAX, nat, nat_nla_policy, NULL);
768 err = l3proto->nlattr_to_range(tb, range);
772 if (!tb[CTA_NAT_PROTO])
775 return nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO], ct, range);
778 /* This function is called under rcu_read_lock() */
780 nfnetlink_parse_nat_setup(struct nf_conn *ct,
781 enum nf_nat_manip_type manip,
782 const struct nlattr *attr)
784 struct nf_nat_range range;
785 const struct nf_nat_l3proto *l3proto;
788 /* Should not happen, restricted to creating new conntracks
791 if (WARN_ON_ONCE(nf_nat_initialized(ct, manip)))
794 /* Make sure that L3 NAT is there by when we call nf_nat_setup_info to
795 * attach the null binding, otherwise this may oops.
797 l3proto = __nf_nat_l3proto_find(nf_ct_l3num(ct));
801 /* No NAT information has been passed, allocate the null-binding */
803 return __nf_nat_alloc_null_binding(ct, manip) == NF_DROP ? -ENOMEM : 0;
805 err = nfnetlink_parse_nat(attr, ct, &range, l3proto);
809 return nf_nat_setup_info(ct, &range, manip) == NF_DROP ? -ENOMEM : 0;
813 nfnetlink_parse_nat_setup(struct nf_conn *ct,
814 enum nf_nat_manip_type manip,
815 const struct nlattr *attr)
821 static void __net_exit nf_nat_net_exit(struct net *net)
823 struct nf_nat_proto_clean clean = {};
825 nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean, 0, 0);
828 static struct pernet_operations nf_nat_net_ops = {
829 .exit = nf_nat_net_exit,
832 static struct nf_ct_helper_expectfn follow_master_nat = {
833 .name = "nat-follow-master",
834 .expectfn = nf_nat_follow_master,
837 static int __init nf_nat_init(void)
841 ret = rhltable_init(&nf_nat_bysource_table, &nf_nat_bysource_params);
845 ret = nf_ct_extend_register(&nat_extend);
847 rhltable_destroy(&nf_nat_bysource_table);
848 printk(KERN_ERR "nf_nat_core: Unable to register extension\n");
852 ret = register_pernet_subsys(&nf_nat_net_ops);
856 nf_ct_helper_expectfn_register(&follow_master_nat);
858 BUG_ON(nfnetlink_parse_nat_setup_hook != NULL);
859 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook,
860 nfnetlink_parse_nat_setup);
862 BUG_ON(nf_nat_decode_session_hook != NULL);
863 RCU_INIT_POINTER(nf_nat_decode_session_hook, __nf_nat_decode_session);
868 rhltable_destroy(&nf_nat_bysource_table);
869 nf_ct_extend_unregister(&nat_extend);
873 static void __exit nf_nat_cleanup(void)
877 unregister_pernet_subsys(&nf_nat_net_ops);
878 nf_ct_extend_unregister(&nat_extend);
879 nf_ct_helper_expectfn_unregister(&follow_master_nat);
880 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook, NULL);
882 RCU_INIT_POINTER(nf_nat_decode_session_hook, NULL);
886 for (i = 0; i < NFPROTO_NUMPROTO; i++)
887 kfree(nf_nat_l4protos[i]);
889 rhltable_destroy(&nf_nat_bysource_table);
892 MODULE_LICENSE("GPL");
894 module_init(nf_nat_init);
895 module_exit(nf_nat_cleanup);