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 rhashtable 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 = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
76 l3proto = __nf_nat_l3proto_find(family);
80 dir = CTINFO2DIR(ctinfo);
81 if (dir == IP_CT_DIR_ORIGINAL)
82 statusbit = IPS_DST_NAT;
84 statusbit = IPS_SRC_NAT;
86 l3proto->decode_session(skb, ct, dir, statusbit, fl);
91 int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family)
95 struct dst_entry *dst;
98 err = xfrm_decode_session(skb, &fl, family);
104 dst = ((struct xfrm_dst *)dst)->route;
107 dst = xfrm_lookup(net, dst, &fl, skb->sk, 0);
112 skb_dst_set(skb, dst);
114 /* Change in oif may mean change in hh_len. */
115 hh_len = skb_dst(skb)->dev->hard_header_len;
116 if (skb_headroom(skb) < hh_len &&
117 pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
121 EXPORT_SYMBOL(nf_xfrm_me_harder);
122 #endif /* CONFIG_XFRM */
124 static u32 nf_nat_bysource_hash(const void *data, u32 len, u32 seed)
126 const struct nf_conntrack_tuple *t;
127 const struct nf_conn *ct = data;
129 t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
130 /* Original src, to ensure we map it consistently if poss. */
132 seed ^= net_hash_mix(nf_ct_net(ct));
133 return jhash2((const u32 *)&t->src, sizeof(t->src) / sizeof(u32),
134 t->dst.protonum ^ seed);
137 /* Is this tuple already taken? (not by us) */
139 nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
140 const struct nf_conn *ignored_conntrack)
142 /* Conntrack tracking doesn't keep track of outgoing tuples; only
143 * incoming ones. NAT means they don't have a fixed mapping,
144 * so we invert the tuple and look for the incoming reply.
146 * We could keep a separate hash if this proves too slow.
148 struct nf_conntrack_tuple reply;
150 nf_ct_invert_tuplepr(&reply, tuple);
151 return nf_conntrack_tuple_taken(&reply, ignored_conntrack);
153 EXPORT_SYMBOL(nf_nat_used_tuple);
155 /* If we source map this tuple so reply looks like reply_tuple, will
156 * that meet the constraints of range.
158 static int in_range(const struct nf_nat_l3proto *l3proto,
159 const struct nf_nat_l4proto *l4proto,
160 const struct nf_conntrack_tuple *tuple,
161 const struct nf_nat_range *range)
163 /* If we are supposed to map IPs, then we must be in the
164 * range specified, otherwise let this drag us onto a new src IP.
166 if (range->flags & NF_NAT_RANGE_MAP_IPS &&
167 !l3proto->in_range(tuple, range))
170 if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) ||
171 l4proto->in_range(tuple, NF_NAT_MANIP_SRC,
172 &range->min_proto, &range->max_proto))
179 same_src(const struct nf_conn *ct,
180 const struct nf_conntrack_tuple *tuple)
182 const struct nf_conntrack_tuple *t;
184 t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
185 return (t->dst.protonum == tuple->dst.protonum &&
186 nf_inet_addr_cmp(&t->src.u3, &tuple->src.u3) &&
187 t->src.u.all == tuple->src.u.all);
190 static int nf_nat_bysource_cmp(struct rhashtable_compare_arg *arg,
193 const struct nf_nat_conn_key *key = arg->key;
194 const struct nf_conn *ct = obj;
196 return same_src(ct, key->tuple) &&
197 net_eq(nf_ct_net(ct), key->net) &&
198 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,
207 .nulls_base = (1U << RHT_BASE_SHIFT),
210 /* Only called for SRC manip */
212 find_appropriate_src(struct net *net,
213 const struct nf_conntrack_zone *zone,
214 const struct nf_nat_l3proto *l3proto,
215 const struct nf_nat_l4proto *l4proto,
216 const struct nf_conntrack_tuple *tuple,
217 struct nf_conntrack_tuple *result,
218 const struct nf_nat_range *range)
220 const struct nf_conn *ct;
221 struct nf_nat_conn_key key = {
227 ct = rhashtable_lookup_fast(&nf_nat_bysource_table, &key,
228 nf_nat_bysource_params);
232 nf_ct_invert_tuplepr(result,
233 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
234 result->dst = tuple->dst;
236 return in_range(l3proto, l4proto, result, range);
239 /* For [FUTURE] fragmentation handling, we want the least-used
240 * src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus
241 * if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
242 * 1-65535, we don't do pro-rata allocation based on ports; we choose
243 * the ip with the lowest src-ip/dst-ip/proto usage.
246 find_best_ips_proto(const struct nf_conntrack_zone *zone,
247 struct nf_conntrack_tuple *tuple,
248 const struct nf_nat_range *range,
249 const struct nf_conn *ct,
250 enum nf_nat_manip_type maniptype)
252 union nf_inet_addr *var_ipp;
255 u32 minip, maxip, j, dist;
258 /* No IP mapping? Do nothing. */
259 if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
262 if (maniptype == NF_NAT_MANIP_SRC)
263 var_ipp = &tuple->src.u3;
265 var_ipp = &tuple->dst.u3;
267 /* Fast path: only one choice. */
268 if (nf_inet_addr_cmp(&range->min_addr, &range->max_addr)) {
269 *var_ipp = range->min_addr;
273 if (nf_ct_l3num(ct) == NFPROTO_IPV4)
274 max = sizeof(var_ipp->ip) / sizeof(u32) - 1;
276 max = sizeof(var_ipp->ip6) / sizeof(u32) - 1;
278 /* Hashing source and destination IPs gives a fairly even
279 * spread in practice (if there are a small number of IPs
280 * involved, there usually aren't that many connections
281 * anyway). The consistency means that servers see the same
282 * client coming from the same IP (some Internet Banking sites
283 * like this), even across reboots.
285 j = jhash2((u32 *)&tuple->src.u3, sizeof(tuple->src.u3) / sizeof(u32),
286 range->flags & NF_NAT_RANGE_PERSISTENT ?
287 0 : (__force u32)tuple->dst.u3.all[max] ^ zone->id);
290 for (i = 0; i <= max; i++) {
291 /* If first bytes of the address are at the maximum, use the
292 * distance. Otherwise use the full range.
295 minip = ntohl((__force __be32)range->min_addr.all[i]);
296 maxip = ntohl((__force __be32)range->max_addr.all[i]);
297 dist = maxip - minip + 1;
303 var_ipp->all[i] = (__force __u32)
304 htonl(minip + reciprocal_scale(j, dist));
305 if (var_ipp->all[i] != range->max_addr.all[i])
308 if (!(range->flags & NF_NAT_RANGE_PERSISTENT))
309 j ^= (__force u32)tuple->dst.u3.all[i];
313 /* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
314 * we change the source to map into the range. For NF_INET_PRE_ROUTING
315 * and NF_INET_LOCAL_OUT, we change the destination to map into the
316 * range. It might not be possible to get a unique tuple, but we try.
317 * At worst (or if we race), we will end up with a final duplicate in
318 * __ip_conntrack_confirm and drop the packet. */
320 get_unique_tuple(struct nf_conntrack_tuple *tuple,
321 const struct nf_conntrack_tuple *orig_tuple,
322 const struct nf_nat_range *range,
324 enum nf_nat_manip_type maniptype)
326 const struct nf_conntrack_zone *zone;
327 const struct nf_nat_l3proto *l3proto;
328 const struct nf_nat_l4proto *l4proto;
329 struct net *net = nf_ct_net(ct);
331 zone = nf_ct_zone(ct);
334 l3proto = __nf_nat_l3proto_find(orig_tuple->src.l3num);
335 l4proto = __nf_nat_l4proto_find(orig_tuple->src.l3num,
336 orig_tuple->dst.protonum);
338 /* 1) If this srcip/proto/src-proto-part is currently mapped,
339 * and that same mapping gives a unique tuple within the given
342 * This is only required for source (ie. NAT/masq) mappings.
343 * So far, we don't do local source mappings, so multiple
344 * manips not an issue.
346 if (maniptype == NF_NAT_MANIP_SRC &&
347 !(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
348 /* try the original tuple first */
349 if (in_range(l3proto, l4proto, orig_tuple, range)) {
350 if (!nf_nat_used_tuple(orig_tuple, ct)) {
351 *tuple = *orig_tuple;
354 } else if (find_appropriate_src(net, zone, l3proto, l4proto,
355 orig_tuple, tuple, range)) {
356 pr_debug("get_unique_tuple: Found current src map\n");
357 if (!nf_nat_used_tuple(tuple, ct))
362 /* 2) Select the least-used IP/proto combination in the given range */
363 *tuple = *orig_tuple;
364 find_best_ips_proto(zone, tuple, range, ct, maniptype);
366 /* 3) The per-protocol part of the manip is made to map into
367 * the range to make a unique tuple.
370 /* Only bother mapping if it's not already in range and unique */
371 if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
372 if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
373 if (l4proto->in_range(tuple, maniptype,
375 &range->max_proto) &&
376 (range->min_proto.all == range->max_proto.all ||
377 !nf_nat_used_tuple(tuple, ct)))
379 } else if (!nf_nat_used_tuple(tuple, ct)) {
384 /* Last change: get protocol to try to obtain unique tuple. */
385 l4proto->unique_tuple(l3proto, tuple, range, maniptype, ct);
390 struct nf_conn_nat *nf_ct_nat_ext_add(struct nf_conn *ct)
392 struct nf_conn_nat *nat = nfct_nat(ct);
396 if (!nf_ct_is_confirmed(ct))
397 nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
401 EXPORT_SYMBOL_GPL(nf_ct_nat_ext_add);
404 nf_nat_setup_info(struct nf_conn *ct,
405 const struct nf_nat_range *range,
406 enum nf_nat_manip_type maniptype)
408 struct nf_conntrack_tuple curr_tuple, new_tuple;
409 struct nf_conn_nat *nat;
411 /* nat helper or nfctnetlink also setup binding */
412 nat = nf_ct_nat_ext_add(ct);
416 NF_CT_ASSERT(maniptype == NF_NAT_MANIP_SRC ||
417 maniptype == NF_NAT_MANIP_DST);
418 BUG_ON(nf_nat_initialized(ct, maniptype));
420 /* What we've got will look like inverse of reply. Normally
421 * this is what is in the conntrack, except for prior
422 * manipulations (future optimization: if num_manips == 0,
423 * orig_tp = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple)
425 nf_ct_invert_tuplepr(&curr_tuple,
426 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
428 get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype);
430 if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) {
431 struct nf_conntrack_tuple reply;
433 /* Alter conntrack table so will recognize replies. */
434 nf_ct_invert_tuplepr(&reply, &new_tuple);
435 nf_conntrack_alter_reply(ct, &reply);
437 /* Non-atomic: we own this at the moment. */
438 if (maniptype == NF_NAT_MANIP_SRC)
439 ct->status |= IPS_SRC_NAT;
441 ct->status |= IPS_DST_NAT;
444 nfct_seqadj_ext_add(ct);
447 if (maniptype == NF_NAT_MANIP_SRC) {
450 err = rhashtable_insert_fast(&nf_nat_bysource_table,
452 nf_nat_bysource_params);
458 if (maniptype == NF_NAT_MANIP_DST)
459 ct->status |= IPS_DST_NAT_DONE;
461 ct->status |= IPS_SRC_NAT_DONE;
465 EXPORT_SYMBOL(nf_nat_setup_info);
468 __nf_nat_alloc_null_binding(struct nf_conn *ct, enum nf_nat_manip_type manip)
470 /* Force range to this IP; let proto decide mapping for
471 * per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
472 * Use reply in case it's already been mangled (eg local packet).
474 union nf_inet_addr ip =
475 (manip == NF_NAT_MANIP_SRC ?
476 ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3 :
477 ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3);
478 struct nf_nat_range range = {
479 .flags = NF_NAT_RANGE_MAP_IPS,
483 return nf_nat_setup_info(ct, &range, manip);
487 nf_nat_alloc_null_binding(struct nf_conn *ct, unsigned int hooknum)
489 return __nf_nat_alloc_null_binding(ct, HOOK2MANIP(hooknum));
491 EXPORT_SYMBOL_GPL(nf_nat_alloc_null_binding);
493 /* Do packet manipulations according to nf_nat_setup_info. */
494 unsigned int nf_nat_packet(struct nf_conn *ct,
495 enum ip_conntrack_info ctinfo,
496 unsigned int hooknum,
499 const struct nf_nat_l3proto *l3proto;
500 const struct nf_nat_l4proto *l4proto;
501 enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
502 unsigned long statusbit;
503 enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum);
505 if (mtype == NF_NAT_MANIP_SRC)
506 statusbit = IPS_SRC_NAT;
508 statusbit = IPS_DST_NAT;
510 /* Invert if this is reply dir. */
511 if (dir == IP_CT_DIR_REPLY)
512 statusbit ^= IPS_NAT_MASK;
514 /* Non-atomic: these bits don't change. */
515 if (ct->status & statusbit) {
516 struct nf_conntrack_tuple target;
518 /* We are aiming to look like inverse of other direction. */
519 nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
521 l3proto = __nf_nat_l3proto_find(target.src.l3num);
522 l4proto = __nf_nat_l4proto_find(target.src.l3num,
523 target.dst.protonum);
524 if (!l3proto->manip_pkt(skb, 0, l4proto, &target, mtype))
529 EXPORT_SYMBOL_GPL(nf_nat_packet);
531 struct nf_nat_proto_clean {
536 /* kill conntracks with affected NAT section */
537 static int nf_nat_proto_remove(struct nf_conn *i, void *data)
539 const struct nf_nat_proto_clean *clean = data;
540 struct nf_conn_nat *nat = nfct_nat(i);
545 if ((clean->l3proto && nf_ct_l3num(i) != clean->l3proto) ||
546 (clean->l4proto && nf_ct_protonum(i) != clean->l4proto))
549 return i->status & IPS_NAT_MASK ? 1 : 0;
552 static int nf_nat_proto_clean(struct nf_conn *ct, void *data)
554 struct nf_conn_nat *nat = nfct_nat(ct);
556 if (nf_nat_proto_remove(ct, data))
562 /* This netns is being destroyed, and conntrack has nat null binding.
563 * Remove it from bysource hash, as the table will be freed soon.
565 * Else, when the conntrack is destoyed, nf_nat_cleanup_conntrack()
566 * will delete entry from already-freed table.
568 if (!del_timer(&ct->timeout))
571 ct->status &= ~IPS_NAT_DONE_MASK;
573 rhashtable_remove_fast(&nf_nat_bysource_table, &ct->nat_bysource,
574 nf_nat_bysource_params);
576 add_timer(&ct->timeout);
578 /* don't delete conntrack. Although that would make things a lot
579 * simpler, we'd end up flushing all conntracks on nat rmmod.
584 static void nf_nat_l4proto_clean(u8 l3proto, u8 l4proto)
586 struct nf_nat_proto_clean clean = {
594 nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean, 0, 0);
598 static void nf_nat_l3proto_clean(u8 l3proto)
600 struct nf_nat_proto_clean clean = {
608 nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean, 0, 0);
612 /* Protocol registration. */
613 int nf_nat_l4proto_register(u8 l3proto, const struct nf_nat_l4proto *l4proto)
615 const struct nf_nat_l4proto **l4protos;
619 mutex_lock(&nf_nat_proto_mutex);
620 if (nf_nat_l4protos[l3proto] == NULL) {
621 l4protos = kmalloc(IPPROTO_MAX * sizeof(struct nf_nat_l4proto *),
623 if (l4protos == NULL) {
628 for (i = 0; i < IPPROTO_MAX; i++)
629 RCU_INIT_POINTER(l4protos[i], &nf_nat_l4proto_unknown);
631 /* Before making proto_array visible to lockless readers,
632 * we must make sure its content is committed to memory.
636 nf_nat_l4protos[l3proto] = l4protos;
639 if (rcu_dereference_protected(
640 nf_nat_l4protos[l3proto][l4proto->l4proto],
641 lockdep_is_held(&nf_nat_proto_mutex)
642 ) != &nf_nat_l4proto_unknown) {
646 RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto], l4proto);
648 mutex_unlock(&nf_nat_proto_mutex);
651 EXPORT_SYMBOL_GPL(nf_nat_l4proto_register);
653 /* No one stores the protocol anywhere; simply delete it. */
654 void nf_nat_l4proto_unregister(u8 l3proto, const struct nf_nat_l4proto *l4proto)
656 mutex_lock(&nf_nat_proto_mutex);
657 RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto],
658 &nf_nat_l4proto_unknown);
659 mutex_unlock(&nf_nat_proto_mutex);
662 nf_nat_l4proto_clean(l3proto, l4proto->l4proto);
664 EXPORT_SYMBOL_GPL(nf_nat_l4proto_unregister);
666 int nf_nat_l3proto_register(const struct nf_nat_l3proto *l3proto)
670 err = nf_ct_l3proto_try_module_get(l3proto->l3proto);
674 mutex_lock(&nf_nat_proto_mutex);
675 RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_TCP],
676 &nf_nat_l4proto_tcp);
677 RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_UDP],
678 &nf_nat_l4proto_udp);
679 mutex_unlock(&nf_nat_proto_mutex);
681 RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], l3proto);
684 EXPORT_SYMBOL_GPL(nf_nat_l3proto_register);
686 void nf_nat_l3proto_unregister(const struct nf_nat_l3proto *l3proto)
688 mutex_lock(&nf_nat_proto_mutex);
689 RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], NULL);
690 mutex_unlock(&nf_nat_proto_mutex);
693 nf_nat_l3proto_clean(l3proto->l3proto);
694 nf_ct_l3proto_module_put(l3proto->l3proto);
696 EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister);
698 /* No one using conntrack by the time this called. */
699 static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
701 struct nf_conn_nat *nat = nf_ct_ext_find(ct, NF_CT_EXT_NAT);
706 rhashtable_remove_fast(&nf_nat_bysource_table, &ct->nat_bysource,
707 nf_nat_bysource_params);
710 static struct nf_ct_ext_type nat_extend __read_mostly = {
711 .len = sizeof(struct nf_conn_nat),
712 .align = __alignof__(struct nf_conn_nat),
713 .destroy = nf_nat_cleanup_conntrack,
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 void __net_exit nf_nat_net_exit(struct net *net)
824 struct nf_nat_proto_clean clean = {};
826 nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean, 0, 0);
829 static struct pernet_operations nf_nat_net_ops = {
830 .exit = nf_nat_net_exit,
833 static struct nf_ct_helper_expectfn follow_master_nat = {
834 .name = "nat-follow-master",
835 .expectfn = nf_nat_follow_master,
838 static int __init nf_nat_init(void)
842 ret = rhashtable_init(&nf_nat_bysource_table, &nf_nat_bysource_params);
846 ret = nf_ct_extend_register(&nat_extend);
848 rhashtable_destroy(&nf_nat_bysource_table);
849 printk(KERN_ERR "nf_nat_core: Unable to register extension\n");
853 ret = register_pernet_subsys(&nf_nat_net_ops);
857 nf_ct_helper_expectfn_register(&follow_master_nat);
859 /* Initialize fake conntrack so that NAT will skip it */
860 nf_ct_untracked_status_or(IPS_NAT_DONE_MASK);
862 BUG_ON(nfnetlink_parse_nat_setup_hook != NULL);
863 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook,
864 nfnetlink_parse_nat_setup);
866 BUG_ON(nf_nat_decode_session_hook != NULL);
867 RCU_INIT_POINTER(nf_nat_decode_session_hook, __nf_nat_decode_session);
872 rhashtable_destroy(&nf_nat_bysource_table);
873 nf_ct_extend_unregister(&nat_extend);
877 static void __exit nf_nat_cleanup(void)
881 unregister_pernet_subsys(&nf_nat_net_ops);
882 nf_ct_extend_unregister(&nat_extend);
883 nf_ct_helper_expectfn_unregister(&follow_master_nat);
884 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook, NULL);
886 RCU_INIT_POINTER(nf_nat_decode_session_hook, NULL);
888 for (i = 0; i < NFPROTO_NUMPROTO; i++)
889 kfree(nf_nat_l4protos[i]);
891 rhashtable_destroy(&nf_nat_bysource_table);
894 MODULE_LICENSE("GPL");
896 module_init(nf_nat_init);
897 module_exit(nf_nat_cleanup);