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 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(dev_net(dst->dev), 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, u16 zone,
122 const struct nf_conntrack_tuple *tuple)
126 /* Original src, to ensure we map it consistently if poss. */
127 hash = jhash2((u32 *)&tuple->src, sizeof(tuple->src) / sizeof(u32),
128 tuple->dst.protonum ^ zone ^ nf_conntrack_hash_rnd);
130 return reciprocal_scale(hash, net->ct.nat_htable_size);
133 /* Is this tuple already taken? (not by us) */
135 nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
136 const struct nf_conn *ignored_conntrack)
138 /* Conntrack tracking doesn't keep track of outgoing tuples; only
139 * incoming ones. NAT means they don't have a fixed mapping,
140 * so we invert the tuple and look for the incoming reply.
142 * We could keep a separate hash if this proves too slow.
144 struct nf_conntrack_tuple reply;
146 nf_ct_invert_tuplepr(&reply, tuple);
147 return nf_conntrack_tuple_taken(&reply, ignored_conntrack);
149 EXPORT_SYMBOL(nf_nat_used_tuple);
151 /* If we source map this tuple so reply looks like reply_tuple, will
152 * that meet the constraints of range.
154 static int in_range(const struct nf_nat_l3proto *l3proto,
155 const struct nf_nat_l4proto *l4proto,
156 const struct nf_conntrack_tuple *tuple,
157 const struct nf_nat_range *range)
159 /* If we are supposed to map IPs, then we must be in the
160 * range specified, otherwise let this drag us onto a new src IP.
162 if (range->flags & NF_NAT_RANGE_MAP_IPS &&
163 !l3proto->in_range(tuple, range))
166 if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) ||
167 l4proto->in_range(tuple, NF_NAT_MANIP_SRC,
168 &range->min_proto, &range->max_proto))
175 same_src(const struct nf_conn *ct,
176 const struct nf_conntrack_tuple *tuple)
178 const struct nf_conntrack_tuple *t;
180 t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
181 return (t->dst.protonum == tuple->dst.protonum &&
182 nf_inet_addr_cmp(&t->src.u3, &tuple->src.u3) &&
183 t->src.u.all == tuple->src.u.all);
186 /* Only called for SRC manip */
188 find_appropriate_src(struct net *net, u16 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, zone, 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) && nf_ct_zone(ct) == zone) {
202 /* Copy source part from reply tuple. */
203 nf_ct_invert_tuplepr(result,
204 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
205 result->dst = tuple->dst;
207 if (in_range(l3proto, l4proto, result, range))
214 /* For [FUTURE] fragmentation handling, we want the least-used
215 * src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus
216 * if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
217 * 1-65535, we don't do pro-rata allocation based on ports; we choose
218 * the ip with the lowest src-ip/dst-ip/proto usage.
221 find_best_ips_proto(u16 zone, struct nf_conntrack_tuple *tuple,
222 const struct nf_nat_range *range,
223 const struct nf_conn *ct,
224 enum nf_nat_manip_type maniptype)
226 union nf_inet_addr *var_ipp;
229 u32 minip, maxip, j, dist;
232 /* No IP mapping? Do nothing. */
233 if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
236 if (maniptype == NF_NAT_MANIP_SRC)
237 var_ipp = &tuple->src.u3;
239 var_ipp = &tuple->dst.u3;
241 /* Fast path: only one choice. */
242 if (nf_inet_addr_cmp(&range->min_addr, &range->max_addr)) {
243 *var_ipp = range->min_addr;
247 if (nf_ct_l3num(ct) == NFPROTO_IPV4)
248 max = sizeof(var_ipp->ip) / sizeof(u32) - 1;
250 max = sizeof(var_ipp->ip6) / sizeof(u32) - 1;
252 /* Hashing source and destination IPs gives a fairly even
253 * spread in practice (if there are a small number of IPs
254 * involved, there usually aren't that many connections
255 * anyway). The consistency means that servers see the same
256 * client coming from the same IP (some Internet Banking sites
257 * like this), even across reboots.
259 j = jhash2((u32 *)&tuple->src.u3, sizeof(tuple->src.u3) / sizeof(u32),
260 range->flags & NF_NAT_RANGE_PERSISTENT ?
261 0 : (__force u32)tuple->dst.u3.all[max] ^ zone);
264 for (i = 0; i <= max; i++) {
265 /* If first bytes of the address are at the maximum, use the
266 * distance. Otherwise use the full range.
269 minip = ntohl((__force __be32)range->min_addr.all[i]);
270 maxip = ntohl((__force __be32)range->max_addr.all[i]);
271 dist = maxip - minip + 1;
277 var_ipp->all[i] = (__force __u32)
278 htonl(minip + reciprocal_scale(j, dist));
279 if (var_ipp->all[i] != range->max_addr.all[i])
282 if (!(range->flags & NF_NAT_RANGE_PERSISTENT))
283 j ^= (__force u32)tuple->dst.u3.all[i];
287 /* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
288 * we change the source to map into the range. For NF_INET_PRE_ROUTING
289 * and NF_INET_LOCAL_OUT, we change the destination to map into the
290 * range. It might not be possible to get a unique tuple, but we try.
291 * At worst (or if we race), we will end up with a final duplicate in
292 * __ip_conntrack_confirm and drop the packet. */
294 get_unique_tuple(struct nf_conntrack_tuple *tuple,
295 const struct nf_conntrack_tuple *orig_tuple,
296 const struct nf_nat_range *range,
298 enum nf_nat_manip_type maniptype)
300 const struct nf_nat_l3proto *l3proto;
301 const struct nf_nat_l4proto *l4proto;
302 struct net *net = nf_ct_net(ct);
303 u16 zone = nf_ct_zone(ct);
306 l3proto = __nf_nat_l3proto_find(orig_tuple->src.l3num);
307 l4proto = __nf_nat_l4proto_find(orig_tuple->src.l3num,
308 orig_tuple->dst.protonum);
310 /* 1) If this srcip/proto/src-proto-part is currently mapped,
311 * and that same mapping gives a unique tuple within the given
314 * This is only required for source (ie. NAT/masq) mappings.
315 * So far, we don't do local source mappings, so multiple
316 * manips not an issue.
318 if (maniptype == NF_NAT_MANIP_SRC &&
319 !(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
320 /* try the original tuple first */
321 if (in_range(l3proto, l4proto, orig_tuple, range)) {
322 if (!nf_nat_used_tuple(orig_tuple, ct)) {
323 *tuple = *orig_tuple;
326 } else if (find_appropriate_src(net, zone, l3proto, l4proto,
327 orig_tuple, tuple, range)) {
328 pr_debug("get_unique_tuple: Found current src map\n");
329 if (!nf_nat_used_tuple(tuple, ct))
334 /* 2) Select the least-used IP/proto combination in the given range */
335 *tuple = *orig_tuple;
336 find_best_ips_proto(zone, tuple, range, ct, maniptype);
338 /* 3) The per-protocol part of the manip is made to map into
339 * the range to make a unique tuple.
342 /* Only bother mapping if it's not already in range and unique */
343 if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
344 if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
345 if (l4proto->in_range(tuple, maniptype,
347 &range->max_proto) &&
348 (range->min_proto.all == range->max_proto.all ||
349 !nf_nat_used_tuple(tuple, ct)))
351 } else if (!nf_nat_used_tuple(tuple, ct)) {
356 /* Last change: get protocol to try to obtain unique tuple. */
357 l4proto->unique_tuple(l3proto, tuple, range, maniptype, ct);
362 struct nf_conn_nat *nf_ct_nat_ext_add(struct nf_conn *ct)
364 struct nf_conn_nat *nat = nfct_nat(ct);
368 if (!nf_ct_is_confirmed(ct))
369 nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
373 EXPORT_SYMBOL_GPL(nf_ct_nat_ext_add);
376 nf_nat_setup_info(struct nf_conn *ct,
377 const struct nf_nat_range *range,
378 enum nf_nat_manip_type maniptype)
380 struct net *net = nf_ct_net(ct);
381 struct nf_conntrack_tuple curr_tuple, new_tuple;
382 struct nf_conn_nat *nat;
384 /* nat helper or nfctnetlink also setup binding */
385 nat = nf_ct_nat_ext_add(ct);
389 NF_CT_ASSERT(maniptype == NF_NAT_MANIP_SRC ||
390 maniptype == NF_NAT_MANIP_DST);
391 BUG_ON(nf_nat_initialized(ct, maniptype));
393 /* What we've got will look like inverse of reply. Normally
394 * this is what is in the conntrack, except for prior
395 * manipulations (future optimization: if num_manips == 0,
396 * orig_tp = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple)
398 nf_ct_invert_tuplepr(&curr_tuple,
399 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
401 get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype);
403 if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) {
404 struct nf_conntrack_tuple reply;
406 /* Alter conntrack table so will recognize replies. */
407 nf_ct_invert_tuplepr(&reply, &new_tuple);
408 nf_conntrack_alter_reply(ct, &reply);
410 /* Non-atomic: we own this at the moment. */
411 if (maniptype == NF_NAT_MANIP_SRC)
412 ct->status |= IPS_SRC_NAT;
414 ct->status |= IPS_DST_NAT;
417 nfct_seqadj_ext_add(ct);
420 if (maniptype == NF_NAT_MANIP_SRC) {
421 unsigned int srchash;
423 srchash = hash_by_src(net, nf_ct_zone(ct),
424 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
425 spin_lock_bh(&nf_nat_lock);
426 /* nf_conntrack_alter_reply might re-allocate extension aera */
429 hlist_add_head_rcu(&nat->bysource,
430 &net->ct.nat_bysource[srchash]);
431 spin_unlock_bh(&nf_nat_lock);
435 if (maniptype == NF_NAT_MANIP_DST)
436 ct->status |= IPS_DST_NAT_DONE;
438 ct->status |= IPS_SRC_NAT_DONE;
442 EXPORT_SYMBOL(nf_nat_setup_info);
445 __nf_nat_alloc_null_binding(struct nf_conn *ct, enum nf_nat_manip_type manip)
447 /* Force range to this IP; let proto decide mapping for
448 * per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
449 * Use reply in case it's already been mangled (eg local packet).
451 union nf_inet_addr ip =
452 (manip == NF_NAT_MANIP_SRC ?
453 ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3 :
454 ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3);
455 struct nf_nat_range range = {
456 .flags = NF_NAT_RANGE_MAP_IPS,
460 return nf_nat_setup_info(ct, &range, manip);
464 nf_nat_alloc_null_binding(struct nf_conn *ct, unsigned int hooknum)
466 return __nf_nat_alloc_null_binding(ct, HOOK2MANIP(hooknum));
468 EXPORT_SYMBOL_GPL(nf_nat_alloc_null_binding);
470 /* Do packet manipulations according to nf_nat_setup_info. */
471 unsigned int nf_nat_packet(struct nf_conn *ct,
472 enum ip_conntrack_info ctinfo,
473 unsigned int hooknum,
476 const struct nf_nat_l3proto *l3proto;
477 const struct nf_nat_l4proto *l4proto;
478 enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
479 unsigned long statusbit;
480 enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum);
482 if (mtype == NF_NAT_MANIP_SRC)
483 statusbit = IPS_SRC_NAT;
485 statusbit = IPS_DST_NAT;
487 /* Invert if this is reply dir. */
488 if (dir == IP_CT_DIR_REPLY)
489 statusbit ^= IPS_NAT_MASK;
491 /* Non-atomic: these bits don't change. */
492 if (ct->status & statusbit) {
493 struct nf_conntrack_tuple target;
495 /* We are aiming to look like inverse of other direction. */
496 nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
498 l3proto = __nf_nat_l3proto_find(target.src.l3num);
499 l4proto = __nf_nat_l4proto_find(target.src.l3num,
500 target.dst.protonum);
501 if (!l3proto->manip_pkt(skb, 0, l4proto, &target, mtype))
506 EXPORT_SYMBOL_GPL(nf_nat_packet);
508 struct nf_nat_proto_clean {
513 /* kill conntracks with affected NAT section */
514 static int nf_nat_proto_remove(struct nf_conn *i, void *data)
516 const struct nf_nat_proto_clean *clean = data;
517 struct nf_conn_nat *nat = nfct_nat(i);
522 if ((clean->l3proto && nf_ct_l3num(i) != clean->l3proto) ||
523 (clean->l4proto && nf_ct_protonum(i) != clean->l4proto))
526 return i->status & IPS_NAT_MASK ? 1 : 0;
529 static int nf_nat_proto_clean(struct nf_conn *ct, void *data)
531 struct nf_conn_nat *nat = nfct_nat(ct);
533 if (nf_nat_proto_remove(ct, data))
536 if (!nat || !nat->ct)
539 /* This netns is being destroyed, and conntrack has nat null binding.
540 * Remove it from bysource hash, as the table will be freed soon.
542 * Else, when the conntrack is destoyed, nf_nat_cleanup_conntrack()
543 * will delete entry from already-freed table.
545 if (!del_timer(&ct->timeout))
548 spin_lock_bh(&nf_nat_lock);
549 hlist_del_rcu(&nat->bysource);
550 ct->status &= ~IPS_NAT_DONE_MASK;
552 spin_unlock_bh(&nf_nat_lock);
554 add_timer(&ct->timeout);
556 /* don't delete conntrack. Although that would make things a lot
557 * simpler, we'd end up flushing all conntracks on nat rmmod.
562 static void nf_nat_l4proto_clean(u8 l3proto, u8 l4proto)
564 struct nf_nat_proto_clean clean = {
572 nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean, 0, 0);
576 static void nf_nat_l3proto_clean(u8 l3proto)
578 struct nf_nat_proto_clean clean = {
586 nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean, 0, 0);
590 /* Protocol registration. */
591 int nf_nat_l4proto_register(u8 l3proto, const struct nf_nat_l4proto *l4proto)
593 const struct nf_nat_l4proto **l4protos;
597 mutex_lock(&nf_nat_proto_mutex);
598 if (nf_nat_l4protos[l3proto] == NULL) {
599 l4protos = kmalloc(IPPROTO_MAX * sizeof(struct nf_nat_l4proto *),
601 if (l4protos == NULL) {
606 for (i = 0; i < IPPROTO_MAX; i++)
607 RCU_INIT_POINTER(l4protos[i], &nf_nat_l4proto_unknown);
609 /* Before making proto_array visible to lockless readers,
610 * we must make sure its content is committed to memory.
614 nf_nat_l4protos[l3proto] = l4protos;
617 if (rcu_dereference_protected(
618 nf_nat_l4protos[l3proto][l4proto->l4proto],
619 lockdep_is_held(&nf_nat_proto_mutex)
620 ) != &nf_nat_l4proto_unknown) {
624 RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto], l4proto);
626 mutex_unlock(&nf_nat_proto_mutex);
629 EXPORT_SYMBOL_GPL(nf_nat_l4proto_register);
631 /* No one stores the protocol anywhere; simply delete it. */
632 void nf_nat_l4proto_unregister(u8 l3proto, const struct nf_nat_l4proto *l4proto)
634 mutex_lock(&nf_nat_proto_mutex);
635 RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto],
636 &nf_nat_l4proto_unknown);
637 mutex_unlock(&nf_nat_proto_mutex);
640 nf_nat_l4proto_clean(l3proto, l4proto->l4proto);
642 EXPORT_SYMBOL_GPL(nf_nat_l4proto_unregister);
644 int nf_nat_l3proto_register(const struct nf_nat_l3proto *l3proto)
648 err = nf_ct_l3proto_try_module_get(l3proto->l3proto);
652 mutex_lock(&nf_nat_proto_mutex);
653 RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_TCP],
654 &nf_nat_l4proto_tcp);
655 RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_UDP],
656 &nf_nat_l4proto_udp);
657 mutex_unlock(&nf_nat_proto_mutex);
659 RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], l3proto);
662 EXPORT_SYMBOL_GPL(nf_nat_l3proto_register);
664 void nf_nat_l3proto_unregister(const struct nf_nat_l3proto *l3proto)
666 mutex_lock(&nf_nat_proto_mutex);
667 RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], NULL);
668 mutex_unlock(&nf_nat_proto_mutex);
671 nf_nat_l3proto_clean(l3proto->l3proto);
672 nf_ct_l3proto_module_put(l3proto->l3proto);
674 EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister);
676 /* No one using conntrack by the time this called. */
677 static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
679 struct nf_conn_nat *nat = nf_ct_ext_find(ct, NF_CT_EXT_NAT);
681 if (nat == NULL || nat->ct == NULL)
684 NF_CT_ASSERT(nat->ct->status & IPS_SRC_NAT_DONE);
686 spin_lock_bh(&nf_nat_lock);
687 hlist_del_rcu(&nat->bysource);
688 spin_unlock_bh(&nf_nat_lock);
691 static void nf_nat_move_storage(void *new, void *old)
693 struct nf_conn_nat *new_nat = new;
694 struct nf_conn_nat *old_nat = old;
695 struct nf_conn *ct = old_nat->ct;
697 if (!ct || !(ct->status & IPS_SRC_NAT_DONE))
700 spin_lock_bh(&nf_nat_lock);
701 hlist_replace_rcu(&old_nat->bysource, &new_nat->bysource);
702 spin_unlock_bh(&nf_nat_lock);
705 static struct nf_ct_ext_type nat_extend __read_mostly = {
706 .len = sizeof(struct nf_conn_nat),
707 .align = __alignof__(struct nf_conn_nat),
708 .destroy = nf_nat_cleanup_conntrack,
709 .move = nf_nat_move_storage,
711 .flags = NF_CT_EXT_F_PREALLOC,
714 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
716 #include <linux/netfilter/nfnetlink.h>
717 #include <linux/netfilter/nfnetlink_conntrack.h>
719 static const struct nla_policy protonat_nla_policy[CTA_PROTONAT_MAX+1] = {
720 [CTA_PROTONAT_PORT_MIN] = { .type = NLA_U16 },
721 [CTA_PROTONAT_PORT_MAX] = { .type = NLA_U16 },
724 static int nfnetlink_parse_nat_proto(struct nlattr *attr,
725 const struct nf_conn *ct,
726 struct nf_nat_range *range)
728 struct nlattr *tb[CTA_PROTONAT_MAX+1];
729 const struct nf_nat_l4proto *l4proto;
732 err = nla_parse_nested(tb, CTA_PROTONAT_MAX, attr, protonat_nla_policy);
736 l4proto = __nf_nat_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
737 if (l4proto->nlattr_to_range)
738 err = l4proto->nlattr_to_range(tb, range);
743 static const struct nla_policy nat_nla_policy[CTA_NAT_MAX+1] = {
744 [CTA_NAT_V4_MINIP] = { .type = NLA_U32 },
745 [CTA_NAT_V4_MAXIP] = { .type = NLA_U32 },
746 [CTA_NAT_V6_MINIP] = { .len = sizeof(struct in6_addr) },
747 [CTA_NAT_V6_MAXIP] = { .len = sizeof(struct in6_addr) },
748 [CTA_NAT_PROTO] = { .type = NLA_NESTED },
752 nfnetlink_parse_nat(const struct nlattr *nat,
753 const struct nf_conn *ct, struct nf_nat_range *range,
754 const struct nf_nat_l3proto *l3proto)
756 struct nlattr *tb[CTA_NAT_MAX+1];
759 memset(range, 0, sizeof(*range));
761 err = nla_parse_nested(tb, CTA_NAT_MAX, nat, nat_nla_policy);
765 err = l3proto->nlattr_to_range(tb, range);
769 if (!tb[CTA_NAT_PROTO])
772 return nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO], ct, range);
775 /* This function is called under rcu_read_lock() */
777 nfnetlink_parse_nat_setup(struct nf_conn *ct,
778 enum nf_nat_manip_type manip,
779 const struct nlattr *attr)
781 struct nf_nat_range range;
782 const struct nf_nat_l3proto *l3proto;
785 /* Should not happen, restricted to creating new conntracks
788 if (WARN_ON_ONCE(nf_nat_initialized(ct, manip)))
791 /* Make sure that L3 NAT is there by when we call nf_nat_setup_info to
792 * attach the null binding, otherwise this may oops.
794 l3proto = __nf_nat_l3proto_find(nf_ct_l3num(ct));
798 /* No NAT information has been passed, allocate the null-binding */
800 return __nf_nat_alloc_null_binding(ct, manip);
802 err = nfnetlink_parse_nat(attr, ct, &range, l3proto);
806 return nf_nat_setup_info(ct, &range, manip);
810 nfnetlink_parse_nat_setup(struct nf_conn *ct,
811 enum nf_nat_manip_type manip,
812 const struct nlattr *attr)
818 static int __net_init nf_nat_net_init(struct net *net)
820 /* Leave them the same for the moment. */
821 net->ct.nat_htable_size = net->ct.htable_size;
822 net->ct.nat_bysource = nf_ct_alloc_hashtable(&net->ct.nat_htable_size, 0);
823 if (!net->ct.nat_bysource)
828 static void __net_exit nf_nat_net_exit(struct net *net)
830 struct nf_nat_proto_clean clean = {};
832 nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean, 0, 0);
834 nf_ct_free_hashtable(net->ct.nat_bysource, net->ct.nat_htable_size);
837 static struct pernet_operations nf_nat_net_ops = {
838 .init = nf_nat_net_init,
839 .exit = nf_nat_net_exit,
842 static struct nf_ct_helper_expectfn follow_master_nat = {
843 .name = "nat-follow-master",
844 .expectfn = nf_nat_follow_master,
847 static int __init nf_nat_init(void)
851 ret = nf_ct_extend_register(&nat_extend);
853 printk(KERN_ERR "nf_nat_core: Unable to register extension\n");
857 ret = register_pernet_subsys(&nf_nat_net_ops);
861 nf_ct_helper_expectfn_register(&follow_master_nat);
863 /* Initialize fake conntrack so that NAT will skip it */
864 nf_ct_untracked_status_or(IPS_NAT_DONE_MASK);
866 BUG_ON(nfnetlink_parse_nat_setup_hook != NULL);
867 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook,
868 nfnetlink_parse_nat_setup);
870 BUG_ON(nf_nat_decode_session_hook != NULL);
871 RCU_INIT_POINTER(nf_nat_decode_session_hook, __nf_nat_decode_session);
876 nf_ct_extend_unregister(&nat_extend);
880 static void __exit nf_nat_cleanup(void)
884 unregister_pernet_subsys(&nf_nat_net_ops);
885 nf_ct_extend_unregister(&nat_extend);
886 nf_ct_helper_expectfn_unregister(&follow_master_nat);
887 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook, NULL);
889 RCU_INIT_POINTER(nf_nat_decode_session_hook, NULL);
891 for (i = 0; i < NFPROTO_NUMPROTO; i++)
892 kfree(nf_nat_l4protos[i]);
896 MODULE_LICENSE("GPL");
898 module_init(nf_nat_init);
899 module_exit(nf_nat_cleanup);