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_nat
*nat
;
202 const struct nf_conn
*ct
;
204 hlist_for_each_entry_rcu(nat
, &nf_nat_bysource
[h
], bysource
) {
206 if (same_src(ct
, tuple
) &&
207 net_eq(net
, nf_ct_net(ct
)) &&
208 nf_ct_zone_equal(ct
, zone
, IP_CT_DIR_ORIGINAL
)) {
209 /* Copy source part from reply tuple. */
210 nf_ct_invert_tuplepr(result
,
211 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
212 result
->dst
= tuple
->dst
;
214 if (in_range(l3proto
, l4proto
, result
, range
))
221 /* For [FUTURE] fragmentation handling, we want the least-used
222 * src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus
223 * if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
224 * 1-65535, we don't do pro-rata allocation based on ports; we choose
225 * the ip with the lowest src-ip/dst-ip/proto usage.
228 find_best_ips_proto(const struct nf_conntrack_zone
*zone
,
229 struct nf_conntrack_tuple
*tuple
,
230 const struct nf_nat_range
*range
,
231 const struct nf_conn
*ct
,
232 enum nf_nat_manip_type maniptype
)
234 union nf_inet_addr
*var_ipp
;
237 u32 minip
, maxip
, j
, dist
;
240 /* No IP mapping? Do nothing. */
241 if (!(range
->flags
& NF_NAT_RANGE_MAP_IPS
))
244 if (maniptype
== NF_NAT_MANIP_SRC
)
245 var_ipp
= &tuple
->src
.u3
;
247 var_ipp
= &tuple
->dst
.u3
;
249 /* Fast path: only one choice. */
250 if (nf_inet_addr_cmp(&range
->min_addr
, &range
->max_addr
)) {
251 *var_ipp
= range
->min_addr
;
255 if (nf_ct_l3num(ct
) == NFPROTO_IPV4
)
256 max
= sizeof(var_ipp
->ip
) / sizeof(u32
) - 1;
258 max
= sizeof(var_ipp
->ip6
) / sizeof(u32
) - 1;
260 /* Hashing source and destination IPs gives a fairly even
261 * spread in practice (if there are a small number of IPs
262 * involved, there usually aren't that many connections
263 * anyway). The consistency means that servers see the same
264 * client coming from the same IP (some Internet Banking sites
265 * like this), even across reboots.
267 j
= jhash2((u32
*)&tuple
->src
.u3
, sizeof(tuple
->src
.u3
) / sizeof(u32
),
268 range
->flags
& NF_NAT_RANGE_PERSISTENT
?
269 0 : (__force u32
)tuple
->dst
.u3
.all
[max
] ^ zone
->id
);
272 for (i
= 0; i
<= max
; i
++) {
273 /* If first bytes of the address are at the maximum, use the
274 * distance. Otherwise use the full range.
277 minip
= ntohl((__force __be32
)range
->min_addr
.all
[i
]);
278 maxip
= ntohl((__force __be32
)range
->max_addr
.all
[i
]);
279 dist
= maxip
- minip
+ 1;
285 var_ipp
->all
[i
] = (__force __u32
)
286 htonl(minip
+ reciprocal_scale(j
, dist
));
287 if (var_ipp
->all
[i
] != range
->max_addr
.all
[i
])
290 if (!(range
->flags
& NF_NAT_RANGE_PERSISTENT
))
291 j
^= (__force u32
)tuple
->dst
.u3
.all
[i
];
295 /* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
296 * we change the source to map into the range. For NF_INET_PRE_ROUTING
297 * and NF_INET_LOCAL_OUT, we change the destination to map into the
298 * range. It might not be possible to get a unique tuple, but we try.
299 * At worst (or if we race), we will end up with a final duplicate in
300 * __ip_conntrack_confirm and drop the packet. */
302 get_unique_tuple(struct nf_conntrack_tuple
*tuple
,
303 const struct nf_conntrack_tuple
*orig_tuple
,
304 const struct nf_nat_range
*range
,
306 enum nf_nat_manip_type maniptype
)
308 const struct nf_conntrack_zone
*zone
;
309 const struct nf_nat_l3proto
*l3proto
;
310 const struct nf_nat_l4proto
*l4proto
;
311 struct net
*net
= nf_ct_net(ct
);
313 zone
= nf_ct_zone(ct
);
316 l3proto
= __nf_nat_l3proto_find(orig_tuple
->src
.l3num
);
317 l4proto
= __nf_nat_l4proto_find(orig_tuple
->src
.l3num
,
318 orig_tuple
->dst
.protonum
);
320 /* 1) If this srcip/proto/src-proto-part is currently mapped,
321 * and that same mapping gives a unique tuple within the given
324 * This is only required for source (ie. NAT/masq) mappings.
325 * So far, we don't do local source mappings, so multiple
326 * manips not an issue.
328 if (maniptype
== NF_NAT_MANIP_SRC
&&
329 !(range
->flags
& NF_NAT_RANGE_PROTO_RANDOM_ALL
)) {
330 /* try the original tuple first */
331 if (in_range(l3proto
, l4proto
, orig_tuple
, range
)) {
332 if (!nf_nat_used_tuple(orig_tuple
, ct
)) {
333 *tuple
= *orig_tuple
;
336 } else if (find_appropriate_src(net
, zone
, l3proto
, l4proto
,
337 orig_tuple
, tuple
, range
)) {
338 pr_debug("get_unique_tuple: Found current src map\n");
339 if (!nf_nat_used_tuple(tuple
, ct
))
344 /* 2) Select the least-used IP/proto combination in the given range */
345 *tuple
= *orig_tuple
;
346 find_best_ips_proto(zone
, tuple
, range
, ct
, maniptype
);
348 /* 3) The per-protocol part of the manip is made to map into
349 * the range to make a unique tuple.
352 /* Only bother mapping if it's not already in range and unique */
353 if (!(range
->flags
& NF_NAT_RANGE_PROTO_RANDOM_ALL
)) {
354 if (range
->flags
& NF_NAT_RANGE_PROTO_SPECIFIED
) {
355 if (l4proto
->in_range(tuple
, maniptype
,
357 &range
->max_proto
) &&
358 (range
->min_proto
.all
== range
->max_proto
.all
||
359 !nf_nat_used_tuple(tuple
, ct
)))
361 } else if (!nf_nat_used_tuple(tuple
, ct
)) {
366 /* Last change: get protocol to try to obtain unique tuple. */
367 l4proto
->unique_tuple(l3proto
, tuple
, range
, maniptype
, ct
);
372 struct nf_conn_nat
*nf_ct_nat_ext_add(struct nf_conn
*ct
)
374 struct nf_conn_nat
*nat
= nfct_nat(ct
);
378 if (!nf_ct_is_confirmed(ct
))
379 nat
= nf_ct_ext_add(ct
, NF_CT_EXT_NAT
, GFP_ATOMIC
);
383 EXPORT_SYMBOL_GPL(nf_ct_nat_ext_add
);
386 nf_nat_setup_info(struct nf_conn
*ct
,
387 const struct nf_nat_range
*range
,
388 enum nf_nat_manip_type maniptype
)
390 struct net
*net
= nf_ct_net(ct
);
391 struct nf_conntrack_tuple curr_tuple
, new_tuple
;
392 struct nf_conn_nat
*nat
;
394 /* nat helper or nfctnetlink also setup binding */
395 nat
= nf_ct_nat_ext_add(ct
);
399 NF_CT_ASSERT(maniptype
== NF_NAT_MANIP_SRC
||
400 maniptype
== NF_NAT_MANIP_DST
);
401 BUG_ON(nf_nat_initialized(ct
, maniptype
));
403 /* What we've got will look like inverse of reply. Normally
404 * this is what is in the conntrack, except for prior
405 * manipulations (future optimization: if num_manips == 0,
406 * orig_tp = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple)
408 nf_ct_invert_tuplepr(&curr_tuple
,
409 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
411 get_unique_tuple(&new_tuple
, &curr_tuple
, range
, ct
, maniptype
);
413 if (!nf_ct_tuple_equal(&new_tuple
, &curr_tuple
)) {
414 struct nf_conntrack_tuple reply
;
416 /* Alter conntrack table so will recognize replies. */
417 nf_ct_invert_tuplepr(&reply
, &new_tuple
);
418 nf_conntrack_alter_reply(ct
, &reply
);
420 /* Non-atomic: we own this at the moment. */
421 if (maniptype
== NF_NAT_MANIP_SRC
)
422 ct
->status
|= IPS_SRC_NAT
;
424 ct
->status
|= IPS_DST_NAT
;
427 nfct_seqadj_ext_add(ct
);
430 if (maniptype
== NF_NAT_MANIP_SRC
) {
431 unsigned int srchash
;
433 srchash
= hash_by_src(net
,
434 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
435 spin_lock_bh(&nf_nat_lock
);
436 /* nf_conntrack_alter_reply might re-allocate extension aera */
439 hlist_add_head_rcu(&nat
->bysource
,
440 &nf_nat_bysource
[srchash
]);
441 spin_unlock_bh(&nf_nat_lock
);
445 if (maniptype
== NF_NAT_MANIP_DST
)
446 ct
->status
|= IPS_DST_NAT_DONE
;
448 ct
->status
|= IPS_SRC_NAT_DONE
;
452 EXPORT_SYMBOL(nf_nat_setup_info
);
455 __nf_nat_alloc_null_binding(struct nf_conn
*ct
, enum nf_nat_manip_type manip
)
457 /* Force range to this IP; let proto decide mapping for
458 * per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
459 * Use reply in case it's already been mangled (eg local packet).
461 union nf_inet_addr ip
=
462 (manip
== NF_NAT_MANIP_SRC
?
463 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
.dst
.u3
:
464 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
.src
.u3
);
465 struct nf_nat_range range
= {
466 .flags
= NF_NAT_RANGE_MAP_IPS
,
470 return nf_nat_setup_info(ct
, &range
, manip
);
474 nf_nat_alloc_null_binding(struct nf_conn
*ct
, unsigned int hooknum
)
476 return __nf_nat_alloc_null_binding(ct
, HOOK2MANIP(hooknum
));
478 EXPORT_SYMBOL_GPL(nf_nat_alloc_null_binding
);
480 /* Do packet manipulations according to nf_nat_setup_info. */
481 unsigned int nf_nat_packet(struct nf_conn
*ct
,
482 enum ip_conntrack_info ctinfo
,
483 unsigned int hooknum
,
486 const struct nf_nat_l3proto
*l3proto
;
487 const struct nf_nat_l4proto
*l4proto
;
488 enum ip_conntrack_dir dir
= CTINFO2DIR(ctinfo
);
489 unsigned long statusbit
;
490 enum nf_nat_manip_type mtype
= HOOK2MANIP(hooknum
);
492 if (mtype
== NF_NAT_MANIP_SRC
)
493 statusbit
= IPS_SRC_NAT
;
495 statusbit
= IPS_DST_NAT
;
497 /* Invert if this is reply dir. */
498 if (dir
== IP_CT_DIR_REPLY
)
499 statusbit
^= IPS_NAT_MASK
;
501 /* Non-atomic: these bits don't change. */
502 if (ct
->status
& statusbit
) {
503 struct nf_conntrack_tuple target
;
505 /* We are aiming to look like inverse of other direction. */
506 nf_ct_invert_tuplepr(&target
, &ct
->tuplehash
[!dir
].tuple
);
508 l3proto
= __nf_nat_l3proto_find(target
.src
.l3num
);
509 l4proto
= __nf_nat_l4proto_find(target
.src
.l3num
,
510 target
.dst
.protonum
);
511 if (!l3proto
->manip_pkt(skb
, 0, l4proto
, &target
, mtype
))
516 EXPORT_SYMBOL_GPL(nf_nat_packet
);
518 struct nf_nat_proto_clean
{
523 /* kill conntracks with affected NAT section */
524 static int nf_nat_proto_remove(struct nf_conn
*i
, void *data
)
526 const struct nf_nat_proto_clean
*clean
= data
;
527 struct nf_conn_nat
*nat
= nfct_nat(i
);
532 if ((clean
->l3proto
&& nf_ct_l3num(i
) != clean
->l3proto
) ||
533 (clean
->l4proto
&& nf_ct_protonum(i
) != clean
->l4proto
))
536 return i
->status
& IPS_NAT_MASK
? 1 : 0;
539 static int nf_nat_proto_clean(struct nf_conn
*ct
, void *data
)
541 struct nf_conn_nat
*nat
= nfct_nat(ct
);
543 if (nf_nat_proto_remove(ct
, data
))
546 if (!nat
|| !nat
->ct
)
549 /* This netns is being destroyed, and conntrack has nat null binding.
550 * Remove it from bysource hash, as the table will be freed soon.
552 * Else, when the conntrack is destoyed, nf_nat_cleanup_conntrack()
553 * will delete entry from already-freed table.
555 if (!del_timer(&ct
->timeout
))
558 spin_lock_bh(&nf_nat_lock
);
559 hlist_del_rcu(&nat
->bysource
);
560 ct
->status
&= ~IPS_NAT_DONE_MASK
;
562 spin_unlock_bh(&nf_nat_lock
);
564 add_timer(&ct
->timeout
);
566 /* don't delete conntrack. Although that would make things a lot
567 * simpler, we'd end up flushing all conntracks on nat rmmod.
572 static void nf_nat_l4proto_clean(u8 l3proto
, u8 l4proto
)
574 struct nf_nat_proto_clean clean
= {
582 nf_ct_iterate_cleanup(net
, nf_nat_proto_remove
, &clean
, 0, 0);
586 static void nf_nat_l3proto_clean(u8 l3proto
)
588 struct nf_nat_proto_clean clean
= {
596 nf_ct_iterate_cleanup(net
, nf_nat_proto_remove
, &clean
, 0, 0);
600 /* Protocol registration. */
601 int nf_nat_l4proto_register(u8 l3proto
, const struct nf_nat_l4proto
*l4proto
)
603 const struct nf_nat_l4proto
**l4protos
;
607 mutex_lock(&nf_nat_proto_mutex
);
608 if (nf_nat_l4protos
[l3proto
] == NULL
) {
609 l4protos
= kmalloc(IPPROTO_MAX
* sizeof(struct nf_nat_l4proto
*),
611 if (l4protos
== NULL
) {
616 for (i
= 0; i
< IPPROTO_MAX
; i
++)
617 RCU_INIT_POINTER(l4protos
[i
], &nf_nat_l4proto_unknown
);
619 /* Before making proto_array visible to lockless readers,
620 * we must make sure its content is committed to memory.
624 nf_nat_l4protos
[l3proto
] = l4protos
;
627 if (rcu_dereference_protected(
628 nf_nat_l4protos
[l3proto
][l4proto
->l4proto
],
629 lockdep_is_held(&nf_nat_proto_mutex
)
630 ) != &nf_nat_l4proto_unknown
) {
634 RCU_INIT_POINTER(nf_nat_l4protos
[l3proto
][l4proto
->l4proto
], l4proto
);
636 mutex_unlock(&nf_nat_proto_mutex
);
639 EXPORT_SYMBOL_GPL(nf_nat_l4proto_register
);
641 /* No one stores the protocol anywhere; simply delete it. */
642 void nf_nat_l4proto_unregister(u8 l3proto
, const struct nf_nat_l4proto
*l4proto
)
644 mutex_lock(&nf_nat_proto_mutex
);
645 RCU_INIT_POINTER(nf_nat_l4protos
[l3proto
][l4proto
->l4proto
],
646 &nf_nat_l4proto_unknown
);
647 mutex_unlock(&nf_nat_proto_mutex
);
650 nf_nat_l4proto_clean(l3proto
, l4proto
->l4proto
);
652 EXPORT_SYMBOL_GPL(nf_nat_l4proto_unregister
);
654 int nf_nat_l3proto_register(const struct nf_nat_l3proto
*l3proto
)
658 err
= nf_ct_l3proto_try_module_get(l3proto
->l3proto
);
662 mutex_lock(&nf_nat_proto_mutex
);
663 RCU_INIT_POINTER(nf_nat_l4protos
[l3proto
->l3proto
][IPPROTO_TCP
],
664 &nf_nat_l4proto_tcp
);
665 RCU_INIT_POINTER(nf_nat_l4protos
[l3proto
->l3proto
][IPPROTO_UDP
],
666 &nf_nat_l4proto_udp
);
667 mutex_unlock(&nf_nat_proto_mutex
);
669 RCU_INIT_POINTER(nf_nat_l3protos
[l3proto
->l3proto
], l3proto
);
672 EXPORT_SYMBOL_GPL(nf_nat_l3proto_register
);
674 void nf_nat_l3proto_unregister(const struct nf_nat_l3proto
*l3proto
)
676 mutex_lock(&nf_nat_proto_mutex
);
677 RCU_INIT_POINTER(nf_nat_l3protos
[l3proto
->l3proto
], NULL
);
678 mutex_unlock(&nf_nat_proto_mutex
);
681 nf_nat_l3proto_clean(l3proto
->l3proto
);
682 nf_ct_l3proto_module_put(l3proto
->l3proto
);
684 EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister
);
686 /* No one using conntrack by the time this called. */
687 static void nf_nat_cleanup_conntrack(struct nf_conn
*ct
)
689 struct nf_conn_nat
*nat
= nf_ct_ext_find(ct
, NF_CT_EXT_NAT
);
691 if (nat
== NULL
|| nat
->ct
== NULL
)
694 NF_CT_ASSERT(nat
->ct
->status
& IPS_SRC_NAT_DONE
);
696 spin_lock_bh(&nf_nat_lock
);
697 hlist_del_rcu(&nat
->bysource
);
698 spin_unlock_bh(&nf_nat_lock
);
701 static void nf_nat_move_storage(void *new, void *old
)
703 struct nf_conn_nat
*new_nat
= new;
704 struct nf_conn_nat
*old_nat
= old
;
705 struct nf_conn
*ct
= old_nat
->ct
;
707 if (!ct
|| !(ct
->status
& IPS_SRC_NAT_DONE
))
710 spin_lock_bh(&nf_nat_lock
);
711 hlist_replace_rcu(&old_nat
->bysource
, &new_nat
->bysource
);
712 spin_unlock_bh(&nf_nat_lock
);
715 static struct nf_ct_ext_type nat_extend __read_mostly
= {
716 .len
= sizeof(struct nf_conn_nat
),
717 .align
= __alignof__(struct nf_conn_nat
),
718 .destroy
= nf_nat_cleanup_conntrack
,
719 .move
= nf_nat_move_storage
,
721 .flags
= NF_CT_EXT_F_PREALLOC
,
724 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
726 #include <linux/netfilter/nfnetlink.h>
727 #include <linux/netfilter/nfnetlink_conntrack.h>
729 static const struct nla_policy protonat_nla_policy
[CTA_PROTONAT_MAX
+1] = {
730 [CTA_PROTONAT_PORT_MIN
] = { .type
= NLA_U16
},
731 [CTA_PROTONAT_PORT_MAX
] = { .type
= NLA_U16
},
734 static int nfnetlink_parse_nat_proto(struct nlattr
*attr
,
735 const struct nf_conn
*ct
,
736 struct nf_nat_range
*range
)
738 struct nlattr
*tb
[CTA_PROTONAT_MAX
+1];
739 const struct nf_nat_l4proto
*l4proto
;
742 err
= nla_parse_nested(tb
, CTA_PROTONAT_MAX
, attr
, protonat_nla_policy
);
746 l4proto
= __nf_nat_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
747 if (l4proto
->nlattr_to_range
)
748 err
= l4proto
->nlattr_to_range(tb
, range
);
753 static const struct nla_policy nat_nla_policy
[CTA_NAT_MAX
+1] = {
754 [CTA_NAT_V4_MINIP
] = { .type
= NLA_U32
},
755 [CTA_NAT_V4_MAXIP
] = { .type
= NLA_U32
},
756 [CTA_NAT_V6_MINIP
] = { .len
= sizeof(struct in6_addr
) },
757 [CTA_NAT_V6_MAXIP
] = { .len
= sizeof(struct in6_addr
) },
758 [CTA_NAT_PROTO
] = { .type
= NLA_NESTED
},
762 nfnetlink_parse_nat(const struct nlattr
*nat
,
763 const struct nf_conn
*ct
, struct nf_nat_range
*range
,
764 const struct nf_nat_l3proto
*l3proto
)
766 struct nlattr
*tb
[CTA_NAT_MAX
+1];
769 memset(range
, 0, sizeof(*range
));
771 err
= nla_parse_nested(tb
, CTA_NAT_MAX
, nat
, nat_nla_policy
);
775 err
= l3proto
->nlattr_to_range(tb
, range
);
779 if (!tb
[CTA_NAT_PROTO
])
782 return nfnetlink_parse_nat_proto(tb
[CTA_NAT_PROTO
], ct
, range
);
785 /* This function is called under rcu_read_lock() */
787 nfnetlink_parse_nat_setup(struct nf_conn
*ct
,
788 enum nf_nat_manip_type manip
,
789 const struct nlattr
*attr
)
791 struct nf_nat_range range
;
792 const struct nf_nat_l3proto
*l3proto
;
795 /* Should not happen, restricted to creating new conntracks
798 if (WARN_ON_ONCE(nf_nat_initialized(ct
, manip
)))
801 /* Make sure that L3 NAT is there by when we call nf_nat_setup_info to
802 * attach the null binding, otherwise this may oops.
804 l3proto
= __nf_nat_l3proto_find(nf_ct_l3num(ct
));
808 /* No NAT information has been passed, allocate the null-binding */
810 return __nf_nat_alloc_null_binding(ct
, manip
);
812 err
= nfnetlink_parse_nat(attr
, ct
, &range
, l3proto
);
816 return nf_nat_setup_info(ct
, &range
, manip
);
820 nfnetlink_parse_nat_setup(struct nf_conn
*ct
,
821 enum nf_nat_manip_type manip
,
822 const struct nlattr
*attr
)
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);
835 static struct pernet_operations nf_nat_net_ops
= {
836 .exit
= nf_nat_net_exit
,
839 static struct nf_ct_helper_expectfn follow_master_nat
= {
840 .name
= "nat-follow-master",
841 .expectfn
= nf_nat_follow_master
,
844 static int __init
nf_nat_init(void)
848 /* Leave them the same for the moment. */
849 nf_nat_htable_size
= nf_conntrack_htable_size
;
851 nf_nat_bysource
= nf_ct_alloc_hashtable(&nf_nat_htable_size
, 0);
852 if (!nf_nat_bysource
)
855 ret
= nf_ct_extend_register(&nat_extend
);
857 nf_ct_free_hashtable(nf_nat_bysource
, nf_nat_htable_size
);
858 printk(KERN_ERR
"nf_nat_core: Unable to register extension\n");
862 ret
= register_pernet_subsys(&nf_nat_net_ops
);
866 nf_ct_helper_expectfn_register(&follow_master_nat
);
868 /* Initialize fake conntrack so that NAT will skip it */
869 nf_ct_untracked_status_or(IPS_NAT_DONE_MASK
);
871 BUG_ON(nfnetlink_parse_nat_setup_hook
!= NULL
);
872 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook
,
873 nfnetlink_parse_nat_setup
);
875 BUG_ON(nf_nat_decode_session_hook
!= NULL
);
876 RCU_INIT_POINTER(nf_nat_decode_session_hook
, __nf_nat_decode_session
);
881 nf_ct_free_hashtable(nf_nat_bysource
, nf_nat_htable_size
);
882 nf_ct_extend_unregister(&nat_extend
);
886 static void __exit
nf_nat_cleanup(void)
890 unregister_pernet_subsys(&nf_nat_net_ops
);
891 nf_ct_extend_unregister(&nat_extend
);
892 nf_ct_helper_expectfn_unregister(&follow_master_nat
);
893 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook
, NULL
);
895 RCU_INIT_POINTER(nf_nat_decode_session_hook
, NULL
);
897 for (i
= 0; i
< NFPROTO_NUMPROTO
; i
++)
898 kfree(nf_nat_l4protos
[i
]);
900 nf_ct_free_hashtable(nf_nat_bysource
, nf_nat_htable_size
);
903 MODULE_LICENSE("GPL");
905 module_init(nf_nat_init
);
906 module_exit(nf_nat_cleanup
);