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]
41 static struct hlist_head *nf_nat_bysource __read_mostly;
42 static unsigned int nf_nat_htable_size __read_mostly;
43 static unsigned int nf_nat_hash_rnd __read_mostly;
45 inline const struct nf_nat_l3proto *
46 __nf_nat_l3proto_find(u8 family)
48 return rcu_dereference(nf_nat_l3protos[family]);
51 inline const struct nf_nat_l4proto *
52 __nf_nat_l4proto_find(u8 family, u8 protonum)
54 return rcu_dereference(nf_nat_l4protos[family][protonum]);
56 EXPORT_SYMBOL_GPL(__nf_nat_l4proto_find);
59 static void __nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl)
61 const struct nf_nat_l3proto *l3proto;
62 const struct nf_conn *ct;
63 enum ip_conntrack_info ctinfo;
64 enum ip_conntrack_dir dir;
65 unsigned long statusbit;
68 ct = nf_ct_get(skb, &ctinfo);
72 family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
74 l3proto = __nf_nat_l3proto_find(family);
78 dir = CTINFO2DIR(ctinfo);
79 if (dir == IP_CT_DIR_ORIGINAL)
80 statusbit = IPS_DST_NAT;
82 statusbit = IPS_SRC_NAT;
84 l3proto->decode_session(skb, ct, dir, statusbit, fl);
89 int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family)
93 struct dst_entry *dst;
96 err = xfrm_decode_session(skb, &fl, family);
102 dst = ((struct xfrm_dst *)dst)->route;
105 dst = xfrm_lookup(net, dst, &fl, skb->sk, 0);
110 skb_dst_set(skb, dst);
112 /* Change in oif may mean change in hh_len. */
113 hh_len = skb_dst(skb)->dev->hard_header_len;
114 if (skb_headroom(skb) < hh_len &&
115 pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
119 EXPORT_SYMBOL(nf_xfrm_me_harder);
120 #endif /* CONFIG_XFRM */
122 /* We keep an extra hash for each conntrack, for fast searching. */
123 static inline unsigned int
124 hash_by_src(const struct net *n, const struct nf_conntrack_tuple *tuple)
128 get_random_once(&nf_nat_hash_rnd, sizeof(nf_nat_hash_rnd));
130 /* Original src, to ensure we map it consistently if poss. */
131 hash = jhash2((u32 *)&tuple->src, sizeof(tuple->src) / sizeof(u32),
132 tuple->dst.protonum ^ nf_nat_hash_rnd ^ net_hash_mix(n));
134 return reciprocal_scale(hash, nf_nat_htable_size);
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 /* Only called for SRC manip */
192 find_appropriate_src(struct net *net,
193 const struct nf_conntrack_zone *zone,
194 const struct nf_nat_l3proto *l3proto,
195 const struct nf_nat_l4proto *l4proto,
196 const struct nf_conntrack_tuple *tuple,
197 struct nf_conntrack_tuple *result,
198 const struct nf_nat_range *range)
200 unsigned int h = hash_by_src(net, tuple);
201 const struct nf_conn *ct;
203 hlist_for_each_entry_rcu(ct, &nf_nat_bysource[h], nat_bysource) {
204 if (same_src(ct, tuple) &&
205 net_eq(net, nf_ct_net(ct)) &&
206 nf_ct_zone_equal(ct, zone, IP_CT_DIR_ORIGINAL)) {
207 /* Copy source part from reply tuple. */
208 nf_ct_invert_tuplepr(result,
209 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
210 result->dst = tuple->dst;
212 if (in_range(l3proto, l4proto, result, range))
219 /* For [FUTURE] fragmentation handling, we want the least-used
220 * src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus
221 * if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
222 * 1-65535, we don't do pro-rata allocation based on ports; we choose
223 * the ip with the lowest src-ip/dst-ip/proto usage.
226 find_best_ips_proto(const struct nf_conntrack_zone *zone,
227 struct nf_conntrack_tuple *tuple,
228 const struct nf_nat_range *range,
229 const struct nf_conn *ct,
230 enum nf_nat_manip_type maniptype)
232 union nf_inet_addr *var_ipp;
235 u32 minip, maxip, j, dist;
238 /* No IP mapping? Do nothing. */
239 if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
242 if (maniptype == NF_NAT_MANIP_SRC)
243 var_ipp = &tuple->src.u3;
245 var_ipp = &tuple->dst.u3;
247 /* Fast path: only one choice. */
248 if (nf_inet_addr_cmp(&range->min_addr, &range->max_addr)) {
249 *var_ipp = range->min_addr;
253 if (nf_ct_l3num(ct) == NFPROTO_IPV4)
254 max = sizeof(var_ipp->ip) / sizeof(u32) - 1;
256 max = sizeof(var_ipp->ip6) / sizeof(u32) - 1;
258 /* Hashing source and destination IPs gives a fairly even
259 * spread in practice (if there are a small number of IPs
260 * involved, there usually aren't that many connections
261 * anyway). The consistency means that servers see the same
262 * client coming from the same IP (some Internet Banking sites
263 * like this), even across reboots.
265 j = jhash2((u32 *)&tuple->src.u3, sizeof(tuple->src.u3) / sizeof(u32),
266 range->flags & NF_NAT_RANGE_PERSISTENT ?
267 0 : (__force u32)tuple->dst.u3.all[max] ^ zone->id);
270 for (i = 0; i <= max; i++) {
271 /* If first bytes of the address are at the maximum, use the
272 * distance. Otherwise use the full range.
275 minip = ntohl((__force __be32)range->min_addr.all[i]);
276 maxip = ntohl((__force __be32)range->max_addr.all[i]);
277 dist = maxip - minip + 1;
283 var_ipp->all[i] = (__force __u32)
284 htonl(minip + reciprocal_scale(j, dist));
285 if (var_ipp->all[i] != range->max_addr.all[i])
288 if (!(range->flags & NF_NAT_RANGE_PERSISTENT))
289 j ^= (__force u32)tuple->dst.u3.all[i];
293 /* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
294 * we change the source to map into the range. For NF_INET_PRE_ROUTING
295 * and NF_INET_LOCAL_OUT, we change the destination to map into the
296 * range. It might not be possible to get a unique tuple, but we try.
297 * At worst (or if we race), we will end up with a final duplicate in
298 * __ip_conntrack_confirm and drop the packet. */
300 get_unique_tuple(struct nf_conntrack_tuple *tuple,
301 const struct nf_conntrack_tuple *orig_tuple,
302 const struct nf_nat_range *range,
304 enum nf_nat_manip_type maniptype)
306 const struct nf_conntrack_zone *zone;
307 const struct nf_nat_l3proto *l3proto;
308 const struct nf_nat_l4proto *l4proto;
309 struct net *net = nf_ct_net(ct);
311 zone = nf_ct_zone(ct);
314 l3proto = __nf_nat_l3proto_find(orig_tuple->src.l3num);
315 l4proto = __nf_nat_l4proto_find(orig_tuple->src.l3num,
316 orig_tuple->dst.protonum);
318 /* 1) If this srcip/proto/src-proto-part is currently mapped,
319 * and that same mapping gives a unique tuple within the given
322 * This is only required for source (ie. NAT/masq) mappings.
323 * So far, we don't do local source mappings, so multiple
324 * manips not an issue.
326 if (maniptype == NF_NAT_MANIP_SRC &&
327 !(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
328 /* try the original tuple first */
329 if (in_range(l3proto, l4proto, orig_tuple, range)) {
330 if (!nf_nat_used_tuple(orig_tuple, ct)) {
331 *tuple = *orig_tuple;
334 } else if (find_appropriate_src(net, zone, l3proto, l4proto,
335 orig_tuple, tuple, range)) {
336 pr_debug("get_unique_tuple: Found current src map\n");
337 if (!nf_nat_used_tuple(tuple, ct))
342 /* 2) Select the least-used IP/proto combination in the given range */
343 *tuple = *orig_tuple;
344 find_best_ips_proto(zone, tuple, range, ct, maniptype);
346 /* 3) The per-protocol part of the manip is made to map into
347 * the range to make a unique tuple.
350 /* Only bother mapping if it's not already in range and unique */
351 if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
352 if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
353 if (l4proto->in_range(tuple, maniptype,
355 &range->max_proto) &&
356 (range->min_proto.all == range->max_proto.all ||
357 !nf_nat_used_tuple(tuple, ct)))
359 } else if (!nf_nat_used_tuple(tuple, ct)) {
364 /* Last change: get protocol to try to obtain unique tuple. */
365 l4proto->unique_tuple(l3proto, tuple, range, maniptype, ct);
370 struct nf_conn_nat *nf_ct_nat_ext_add(struct nf_conn *ct)
372 struct nf_conn_nat *nat = nfct_nat(ct);
376 if (!nf_ct_is_confirmed(ct))
377 nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
381 EXPORT_SYMBOL_GPL(nf_ct_nat_ext_add);
384 nf_nat_setup_info(struct nf_conn *ct,
385 const struct nf_nat_range *range,
386 enum nf_nat_manip_type maniptype)
388 struct net *net = nf_ct_net(ct);
389 struct nf_conntrack_tuple curr_tuple, new_tuple;
390 struct nf_conn_nat *nat;
392 /* nat helper or nfctnetlink also setup binding */
393 nat = nf_ct_nat_ext_add(ct);
397 NF_CT_ASSERT(maniptype == NF_NAT_MANIP_SRC ||
398 maniptype == NF_NAT_MANIP_DST);
399 BUG_ON(nf_nat_initialized(ct, maniptype));
401 /* What we've got will look like inverse of reply. Normally
402 * this is what is in the conntrack, except for prior
403 * manipulations (future optimization: if num_manips == 0,
404 * orig_tp = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple)
406 nf_ct_invert_tuplepr(&curr_tuple,
407 &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
409 get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype);
411 if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) {
412 struct nf_conntrack_tuple reply;
414 /* Alter conntrack table so will recognize replies. */
415 nf_ct_invert_tuplepr(&reply, &new_tuple);
416 nf_conntrack_alter_reply(ct, &reply);
418 /* Non-atomic: we own this at the moment. */
419 if (maniptype == NF_NAT_MANIP_SRC)
420 ct->status |= IPS_SRC_NAT;
422 ct->status |= IPS_DST_NAT;
424 if (nfct_help(ct) && !nfct_seqadj(ct))
425 if (!nfct_seqadj_ext_add(ct))
429 if (maniptype == NF_NAT_MANIP_SRC) {
430 unsigned int srchash;
432 srchash = hash_by_src(net,
433 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
434 spin_lock_bh(&nf_nat_lock);
435 /* nf_conntrack_alter_reply might re-allocate extension aera */
437 hlist_add_head_rcu(&ct->nat_bysource,
438 &nf_nat_bysource[srchash]);
439 spin_unlock_bh(&nf_nat_lock);
443 if (maniptype == NF_NAT_MANIP_DST)
444 ct->status |= IPS_DST_NAT_DONE;
446 ct->status |= IPS_SRC_NAT_DONE;
450 EXPORT_SYMBOL(nf_nat_setup_info);
453 __nf_nat_alloc_null_binding(struct nf_conn *ct, enum nf_nat_manip_type manip)
455 /* Force range to this IP; let proto decide mapping for
456 * per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
457 * Use reply in case it's already been mangled (eg local packet).
459 union nf_inet_addr ip =
460 (manip == NF_NAT_MANIP_SRC ?
461 ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3 :
462 ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3);
463 struct nf_nat_range range = {
464 .flags = NF_NAT_RANGE_MAP_IPS,
468 return nf_nat_setup_info(ct, &range, manip);
472 nf_nat_alloc_null_binding(struct nf_conn *ct, unsigned int hooknum)
474 return __nf_nat_alloc_null_binding(ct, HOOK2MANIP(hooknum));
476 EXPORT_SYMBOL_GPL(nf_nat_alloc_null_binding);
478 /* Do packet manipulations according to nf_nat_setup_info. */
479 unsigned int nf_nat_packet(struct nf_conn *ct,
480 enum ip_conntrack_info ctinfo,
481 unsigned int hooknum,
484 const struct nf_nat_l3proto *l3proto;
485 const struct nf_nat_l4proto *l4proto;
486 enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
487 unsigned long statusbit;
488 enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum);
490 if (mtype == NF_NAT_MANIP_SRC)
491 statusbit = IPS_SRC_NAT;
493 statusbit = IPS_DST_NAT;
495 /* Invert if this is reply dir. */
496 if (dir == IP_CT_DIR_REPLY)
497 statusbit ^= IPS_NAT_MASK;
499 /* Non-atomic: these bits don't change. */
500 if (ct->status & statusbit) {
501 struct nf_conntrack_tuple target;
503 /* We are aiming to look like inverse of other direction. */
504 nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
506 l3proto = __nf_nat_l3proto_find(target.src.l3num);
507 l4proto = __nf_nat_l4proto_find(target.src.l3num,
508 target.dst.protonum);
509 if (!l3proto->manip_pkt(skb, 0, l4proto, &target, mtype))
514 EXPORT_SYMBOL_GPL(nf_nat_packet);
516 struct nf_nat_proto_clean {
521 /* kill conntracks with affected NAT section */
522 static int nf_nat_proto_remove(struct nf_conn *i, void *data)
524 const struct nf_nat_proto_clean *clean = data;
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 if (nf_nat_proto_remove(ct, data))
538 if ((ct->status & IPS_SRC_NAT_DONE) == 0)
541 /* This netns is being destroyed, and conntrack has nat null binding.
542 * Remove it from bysource hash, as the table will be freed soon.
544 * Else, when the conntrack is destoyed, nf_nat_cleanup_conntrack()
545 * will delete entry from already-freed table.
547 spin_lock_bh(&nf_nat_lock);
548 hlist_del_rcu(&ct->nat_bysource);
549 ct->status &= ~IPS_NAT_DONE_MASK;
550 spin_unlock_bh(&nf_nat_lock);
552 /* don't delete conntrack. Although that would make things a lot
553 * simpler, we'd end up flushing all conntracks on nat rmmod.
558 static void nf_nat_l4proto_clean(u8 l3proto, u8 l4proto)
560 struct nf_nat_proto_clean clean = {
568 nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean, 0, 0);
572 static void nf_nat_l3proto_clean(u8 l3proto)
574 struct nf_nat_proto_clean clean = {
582 nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean, 0, 0);
586 /* Protocol registration. */
587 int nf_nat_l4proto_register(u8 l3proto, const struct nf_nat_l4proto *l4proto)
589 const struct nf_nat_l4proto **l4protos;
593 mutex_lock(&nf_nat_proto_mutex);
594 if (nf_nat_l4protos[l3proto] == NULL) {
595 l4protos = kmalloc(IPPROTO_MAX * sizeof(struct nf_nat_l4proto *),
597 if (l4protos == NULL) {
602 for (i = 0; i < IPPROTO_MAX; i++)
603 RCU_INIT_POINTER(l4protos[i], &nf_nat_l4proto_unknown);
605 /* Before making proto_array visible to lockless readers,
606 * we must make sure its content is committed to memory.
610 nf_nat_l4protos[l3proto] = l4protos;
613 if (rcu_dereference_protected(
614 nf_nat_l4protos[l3proto][l4proto->l4proto],
615 lockdep_is_held(&nf_nat_proto_mutex)
616 ) != &nf_nat_l4proto_unknown) {
620 RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto], l4proto);
622 mutex_unlock(&nf_nat_proto_mutex);
625 EXPORT_SYMBOL_GPL(nf_nat_l4proto_register);
627 /* No one stores the protocol anywhere; simply delete it. */
628 void nf_nat_l4proto_unregister(u8 l3proto, const struct nf_nat_l4proto *l4proto)
630 mutex_lock(&nf_nat_proto_mutex);
631 RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto],
632 &nf_nat_l4proto_unknown);
633 mutex_unlock(&nf_nat_proto_mutex);
636 nf_nat_l4proto_clean(l3proto, l4proto->l4proto);
638 EXPORT_SYMBOL_GPL(nf_nat_l4proto_unregister);
640 int nf_nat_l3proto_register(const struct nf_nat_l3proto *l3proto)
644 err = nf_ct_l3proto_try_module_get(l3proto->l3proto);
648 mutex_lock(&nf_nat_proto_mutex);
649 RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_TCP],
650 &nf_nat_l4proto_tcp);
651 RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_UDP],
652 &nf_nat_l4proto_udp);
653 mutex_unlock(&nf_nat_proto_mutex);
655 RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], l3proto);
658 EXPORT_SYMBOL_GPL(nf_nat_l3proto_register);
660 void nf_nat_l3proto_unregister(const struct nf_nat_l3proto *l3proto)
662 mutex_lock(&nf_nat_proto_mutex);
663 RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], NULL);
664 mutex_unlock(&nf_nat_proto_mutex);
667 nf_nat_l3proto_clean(l3proto->l3proto);
668 nf_ct_l3proto_module_put(l3proto->l3proto);
670 EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister);
672 /* No one using conntrack by the time this called. */
673 static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
675 if (ct->status & IPS_SRC_NAT_DONE) {
676 spin_lock_bh(&nf_nat_lock);
677 hlist_del_rcu(&ct->nat_bysource);
678 spin_unlock_bh(&nf_nat_lock);
682 static struct nf_ct_ext_type nat_extend __read_mostly = {
683 .len = sizeof(struct nf_conn_nat),
684 .align = __alignof__(struct nf_conn_nat),
685 .destroy = nf_nat_cleanup_conntrack,
687 .flags = NF_CT_EXT_F_PREALLOC,
690 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
692 #include <linux/netfilter/nfnetlink.h>
693 #include <linux/netfilter/nfnetlink_conntrack.h>
695 static const struct nla_policy protonat_nla_policy[CTA_PROTONAT_MAX+1] = {
696 [CTA_PROTONAT_PORT_MIN] = { .type = NLA_U16 },
697 [CTA_PROTONAT_PORT_MAX] = { .type = NLA_U16 },
700 static int nfnetlink_parse_nat_proto(struct nlattr *attr,
701 const struct nf_conn *ct,
702 struct nf_nat_range *range)
704 struct nlattr *tb[CTA_PROTONAT_MAX+1];
705 const struct nf_nat_l4proto *l4proto;
708 err = nla_parse_nested(tb, CTA_PROTONAT_MAX, attr, protonat_nla_policy);
712 l4proto = __nf_nat_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
713 if (l4proto->nlattr_to_range)
714 err = l4proto->nlattr_to_range(tb, range);
719 static const struct nla_policy nat_nla_policy[CTA_NAT_MAX+1] = {
720 [CTA_NAT_V4_MINIP] = { .type = NLA_U32 },
721 [CTA_NAT_V4_MAXIP] = { .type = NLA_U32 },
722 [CTA_NAT_V6_MINIP] = { .len = sizeof(struct in6_addr) },
723 [CTA_NAT_V6_MAXIP] = { .len = sizeof(struct in6_addr) },
724 [CTA_NAT_PROTO] = { .type = NLA_NESTED },
728 nfnetlink_parse_nat(const struct nlattr *nat,
729 const struct nf_conn *ct, struct nf_nat_range *range,
730 const struct nf_nat_l3proto *l3proto)
732 struct nlattr *tb[CTA_NAT_MAX+1];
735 memset(range, 0, sizeof(*range));
737 err = nla_parse_nested(tb, CTA_NAT_MAX, nat, nat_nla_policy);
741 err = l3proto->nlattr_to_range(tb, range);
745 if (!tb[CTA_NAT_PROTO])
748 return nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO], ct, range);
751 /* This function is called under rcu_read_lock() */
753 nfnetlink_parse_nat_setup(struct nf_conn *ct,
754 enum nf_nat_manip_type manip,
755 const struct nlattr *attr)
757 struct nf_nat_range range;
758 const struct nf_nat_l3proto *l3proto;
761 /* Should not happen, restricted to creating new conntracks
764 if (WARN_ON_ONCE(nf_nat_initialized(ct, manip)))
767 /* Make sure that L3 NAT is there by when we call nf_nat_setup_info to
768 * attach the null binding, otherwise this may oops.
770 l3proto = __nf_nat_l3proto_find(nf_ct_l3num(ct));
774 /* No NAT information has been passed, allocate the null-binding */
776 return __nf_nat_alloc_null_binding(ct, manip);
778 err = nfnetlink_parse_nat(attr, ct, &range, l3proto);
782 return nf_nat_setup_info(ct, &range, manip) == NF_DROP ? -ENOMEM : 0;
786 nfnetlink_parse_nat_setup(struct nf_conn *ct,
787 enum nf_nat_manip_type manip,
788 const struct nlattr *attr)
794 static void __net_exit nf_nat_net_exit(struct net *net)
796 struct nf_nat_proto_clean clean = {};
798 nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean, 0, 0);
801 static struct pernet_operations nf_nat_net_ops = {
802 .exit = nf_nat_net_exit,
805 static struct nf_ct_helper_expectfn follow_master_nat = {
806 .name = "nat-follow-master",
807 .expectfn = nf_nat_follow_master,
810 static int __init nf_nat_init(void)
814 /* Leave them the same for the moment. */
815 nf_nat_htable_size = nf_conntrack_htable_size;
817 nf_nat_bysource = nf_ct_alloc_hashtable(&nf_nat_htable_size, 0);
818 if (!nf_nat_bysource)
821 ret = nf_ct_extend_register(&nat_extend);
823 nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
824 printk(KERN_ERR "nf_nat_core: Unable to register extension\n");
828 ret = register_pernet_subsys(&nf_nat_net_ops);
832 nf_ct_helper_expectfn_register(&follow_master_nat);
834 /* Initialize fake conntrack so that NAT will skip it */
835 nf_ct_untracked_status_or(IPS_NAT_DONE_MASK);
837 BUG_ON(nfnetlink_parse_nat_setup_hook != NULL);
838 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook,
839 nfnetlink_parse_nat_setup);
841 BUG_ON(nf_nat_decode_session_hook != NULL);
842 RCU_INIT_POINTER(nf_nat_decode_session_hook, __nf_nat_decode_session);
847 nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
848 nf_ct_extend_unregister(&nat_extend);
852 static void __exit nf_nat_cleanup(void)
856 unregister_pernet_subsys(&nf_nat_net_ops);
857 nf_ct_extend_unregister(&nat_extend);
858 nf_ct_helper_expectfn_unregister(&follow_master_nat);
859 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook, NULL);
861 RCU_INIT_POINTER(nf_nat_decode_session_hook, NULL);
865 for (i = 0; i < NFPROTO_NUMPROTO; i++)
866 kfree(nf_nat_l4protos[i]);
868 nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
871 MODULE_LICENSE("GPL");
873 module_init(nf_nat_init);
874 module_exit(nf_nat_cleanup);