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
);
129 return ((u64
)hash
* net
->ct
.nat_htable_size
) >> 32;
132 /* Is this tuple already taken? (not by us) */
134 nf_nat_used_tuple(const struct nf_conntrack_tuple
*tuple
,
135 const struct nf_conn
*ignored_conntrack
)
137 /* Conntrack tracking doesn't keep track of outgoing tuples; only
138 * incoming ones. NAT means they don't have a fixed mapping,
139 * so we invert the tuple and look for the incoming reply.
141 * We could keep a separate hash if this proves too slow.
143 struct nf_conntrack_tuple reply
;
145 nf_ct_invert_tuplepr(&reply
, tuple
);
146 return nf_conntrack_tuple_taken(&reply
, ignored_conntrack
);
148 EXPORT_SYMBOL(nf_nat_used_tuple
);
150 /* If we source map this tuple so reply looks like reply_tuple, will
151 * that meet the constraints of range.
153 static int in_range(const struct nf_nat_l3proto
*l3proto
,
154 const struct nf_nat_l4proto
*l4proto
,
155 const struct nf_conntrack_tuple
*tuple
,
156 const struct nf_nat_range
*range
)
158 /* If we are supposed to map IPs, then we must be in the
159 * range specified, otherwise let this drag us onto a new src IP.
161 if (range
->flags
& NF_NAT_RANGE_MAP_IPS
&&
162 !l3proto
->in_range(tuple
, range
))
165 if (!(range
->flags
& NF_NAT_RANGE_PROTO_SPECIFIED
) ||
166 l4proto
->in_range(tuple
, NF_NAT_MANIP_SRC
,
167 &range
->min_proto
, &range
->max_proto
))
174 same_src(const struct nf_conn
*ct
,
175 const struct nf_conntrack_tuple
*tuple
)
177 const struct nf_conntrack_tuple
*t
;
179 t
= &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
;
180 return (t
->dst
.protonum
== tuple
->dst
.protonum
&&
181 nf_inet_addr_cmp(&t
->src
.u3
, &tuple
->src
.u3
) &&
182 t
->src
.u
.all
== tuple
->src
.u
.all
);
185 /* Only called for SRC manip */
187 find_appropriate_src(struct net
*net
, u16 zone
,
188 const struct nf_nat_l3proto
*l3proto
,
189 const struct nf_nat_l4proto
*l4proto
,
190 const struct nf_conntrack_tuple
*tuple
,
191 struct nf_conntrack_tuple
*result
,
192 const struct nf_nat_range
*range
)
194 unsigned int h
= hash_by_src(net
, zone
, tuple
);
195 const struct nf_conn_nat
*nat
;
196 const struct nf_conn
*ct
;
198 hlist_for_each_entry_rcu(nat
, &net
->ct
.nat_bysource
[h
], bysource
) {
200 if (same_src(ct
, tuple
) && nf_ct_zone(ct
) == zone
) {
201 /* Copy source part from reply tuple. */
202 nf_ct_invert_tuplepr(result
,
203 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
204 result
->dst
= tuple
->dst
;
206 if (in_range(l3proto
, l4proto
, result
, range
))
213 /* For [FUTURE] fragmentation handling, we want the least-used
214 * src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus
215 * if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
216 * 1-65535, we don't do pro-rata allocation based on ports; we choose
217 * the ip with the lowest src-ip/dst-ip/proto usage.
220 find_best_ips_proto(u16 zone
, struct nf_conntrack_tuple
*tuple
,
221 const struct nf_nat_range
*range
,
222 const struct nf_conn
*ct
,
223 enum nf_nat_manip_type maniptype
)
225 union nf_inet_addr
*var_ipp
;
228 u32 minip
, maxip
, j
, dist
;
231 /* No IP mapping? Do nothing. */
232 if (!(range
->flags
& NF_NAT_RANGE_MAP_IPS
))
235 if (maniptype
== NF_NAT_MANIP_SRC
)
236 var_ipp
= &tuple
->src
.u3
;
238 var_ipp
= &tuple
->dst
.u3
;
240 /* Fast path: only one choice. */
241 if (nf_inet_addr_cmp(&range
->min_addr
, &range
->max_addr
)) {
242 *var_ipp
= range
->min_addr
;
246 if (nf_ct_l3num(ct
) == NFPROTO_IPV4
)
247 max
= sizeof(var_ipp
->ip
) / sizeof(u32
) - 1;
249 max
= sizeof(var_ipp
->ip6
) / sizeof(u32
) - 1;
251 /* Hashing source and destination IPs gives a fairly even
252 * spread in practice (if there are a small number of IPs
253 * involved, there usually aren't that many connections
254 * anyway). The consistency means that servers see the same
255 * client coming from the same IP (some Internet Banking sites
256 * like this), even across reboots.
258 j
= jhash2((u32
*)&tuple
->src
.u3
, sizeof(tuple
->src
.u3
) / sizeof(u32
),
259 range
->flags
& NF_NAT_RANGE_PERSISTENT
?
260 0 : (__force u32
)tuple
->dst
.u3
.all
[max
] ^ zone
);
263 for (i
= 0; i
<= max
; i
++) {
264 /* If first bytes of the address are at the maximum, use the
265 * distance. Otherwise use the full range.
268 minip
= ntohl((__force __be32
)range
->min_addr
.all
[i
]);
269 maxip
= ntohl((__force __be32
)range
->max_addr
.all
[i
]);
270 dist
= maxip
- minip
+ 1;
276 var_ipp
->all
[i
] = (__force __u32
)
277 htonl(minip
+ (((u64
)j
* dist
) >> 32));
278 if (var_ipp
->all
[i
] != range
->max_addr
.all
[i
])
281 if (!(range
->flags
& NF_NAT_RANGE_PERSISTENT
))
282 j
^= (__force u32
)tuple
->dst
.u3
.all
[i
];
286 /* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
287 * we change the source to map into the range. For NF_INET_PRE_ROUTING
288 * and NF_INET_LOCAL_OUT, we change the destination to map into the
289 * range. It might not be possible to get a unique tuple, but we try.
290 * At worst (or if we race), we will end up with a final duplicate in
291 * __ip_conntrack_confirm and drop the packet. */
293 get_unique_tuple(struct nf_conntrack_tuple
*tuple
,
294 const struct nf_conntrack_tuple
*orig_tuple
,
295 const struct nf_nat_range
*range
,
297 enum nf_nat_manip_type maniptype
)
299 const struct nf_nat_l3proto
*l3proto
;
300 const struct nf_nat_l4proto
*l4proto
;
301 struct net
*net
= nf_ct_net(ct
);
302 u16 zone
= nf_ct_zone(ct
);
305 l3proto
= __nf_nat_l3proto_find(orig_tuple
->src
.l3num
);
306 l4proto
= __nf_nat_l4proto_find(orig_tuple
->src
.l3num
,
307 orig_tuple
->dst
.protonum
);
309 /* 1) If this srcip/proto/src-proto-part is currently mapped,
310 * and that same mapping gives a unique tuple within the given
313 * This is only required for source (ie. NAT/masq) mappings.
314 * So far, we don't do local source mappings, so multiple
315 * manips not an issue.
317 if (maniptype
== NF_NAT_MANIP_SRC
&&
318 !(range
->flags
& NF_NAT_RANGE_PROTO_RANDOM_ALL
)) {
319 /* try the original tuple first */
320 if (in_range(l3proto
, l4proto
, orig_tuple
, range
)) {
321 if (!nf_nat_used_tuple(orig_tuple
, ct
)) {
322 *tuple
= *orig_tuple
;
325 } else if (find_appropriate_src(net
, zone
, l3proto
, l4proto
,
326 orig_tuple
, tuple
, range
)) {
327 pr_debug("get_unique_tuple: Found current src map\n");
328 if (!nf_nat_used_tuple(tuple
, ct
))
333 /* 2) Select the least-used IP/proto combination in the given range */
334 *tuple
= *orig_tuple
;
335 find_best_ips_proto(zone
, tuple
, range
, ct
, maniptype
);
337 /* 3) The per-protocol part of the manip is made to map into
338 * the range to make a unique tuple.
341 /* Only bother mapping if it's not already in range and unique */
342 if (!(range
->flags
& NF_NAT_RANGE_PROTO_RANDOM_ALL
)) {
343 if (range
->flags
& NF_NAT_RANGE_PROTO_SPECIFIED
) {
344 if (l4proto
->in_range(tuple
, maniptype
,
346 &range
->max_proto
) &&
347 (range
->min_proto
.all
== range
->max_proto
.all
||
348 !nf_nat_used_tuple(tuple
, ct
)))
350 } else if (!nf_nat_used_tuple(tuple
, ct
)) {
355 /* Last change: get protocol to try to obtain unique tuple. */
356 l4proto
->unique_tuple(l3proto
, tuple
, range
, maniptype
, ct
);
362 nf_nat_setup_info(struct nf_conn
*ct
,
363 const struct nf_nat_range
*range
,
364 enum nf_nat_manip_type maniptype
)
366 struct net
*net
= nf_ct_net(ct
);
367 struct nf_conntrack_tuple curr_tuple
, new_tuple
;
368 struct nf_conn_nat
*nat
;
370 /* nat helper or nfctnetlink also setup binding */
373 nat
= nf_ct_ext_add(ct
, NF_CT_EXT_NAT
, GFP_ATOMIC
);
375 pr_debug("failed to add NAT extension\n");
380 NF_CT_ASSERT(maniptype
== NF_NAT_MANIP_SRC
||
381 maniptype
== NF_NAT_MANIP_DST
);
382 BUG_ON(nf_nat_initialized(ct
, maniptype
));
384 /* What we've got will look like inverse of reply. Normally
385 * this is what is in the conntrack, except for prior
386 * manipulations (future optimization: if num_manips == 0,
387 * orig_tp = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple)
389 nf_ct_invert_tuplepr(&curr_tuple
,
390 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
392 get_unique_tuple(&new_tuple
, &curr_tuple
, range
, ct
, maniptype
);
394 if (!nf_ct_tuple_equal(&new_tuple
, &curr_tuple
)) {
395 struct nf_conntrack_tuple reply
;
397 /* Alter conntrack table so will recognize replies. */
398 nf_ct_invert_tuplepr(&reply
, &new_tuple
);
399 nf_conntrack_alter_reply(ct
, &reply
);
401 /* Non-atomic: we own this at the moment. */
402 if (maniptype
== NF_NAT_MANIP_SRC
)
403 ct
->status
|= IPS_SRC_NAT
;
405 ct
->status
|= IPS_DST_NAT
;
408 nfct_seqadj_ext_add(ct
);
411 if (maniptype
== NF_NAT_MANIP_SRC
) {
412 unsigned int srchash
;
414 srchash
= hash_by_src(net
, nf_ct_zone(ct
),
415 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
416 spin_lock_bh(&nf_nat_lock
);
417 /* nf_conntrack_alter_reply might re-allocate extension aera */
420 hlist_add_head_rcu(&nat
->bysource
,
421 &net
->ct
.nat_bysource
[srchash
]);
422 spin_unlock_bh(&nf_nat_lock
);
426 if (maniptype
== NF_NAT_MANIP_DST
)
427 ct
->status
|= IPS_DST_NAT_DONE
;
429 ct
->status
|= IPS_SRC_NAT_DONE
;
433 EXPORT_SYMBOL(nf_nat_setup_info
);
436 __nf_nat_alloc_null_binding(struct nf_conn
*ct
, enum nf_nat_manip_type manip
)
438 /* Force range to this IP; let proto decide mapping for
439 * per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
440 * Use reply in case it's already been mangled (eg local packet).
442 union nf_inet_addr ip
=
443 (manip
== NF_NAT_MANIP_SRC
?
444 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
.dst
.u3
:
445 ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
.src
.u3
);
446 struct nf_nat_range range
= {
447 .flags
= NF_NAT_RANGE_MAP_IPS
,
451 return nf_nat_setup_info(ct
, &range
, manip
);
455 nf_nat_alloc_null_binding(struct nf_conn
*ct
, unsigned int hooknum
)
457 return __nf_nat_alloc_null_binding(ct
, HOOK2MANIP(hooknum
));
459 EXPORT_SYMBOL_GPL(nf_nat_alloc_null_binding
);
461 /* Do packet manipulations according to nf_nat_setup_info. */
462 unsigned int nf_nat_packet(struct nf_conn
*ct
,
463 enum ip_conntrack_info ctinfo
,
464 unsigned int hooknum
,
467 const struct nf_nat_l3proto
*l3proto
;
468 const struct nf_nat_l4proto
*l4proto
;
469 enum ip_conntrack_dir dir
= CTINFO2DIR(ctinfo
);
470 unsigned long statusbit
;
471 enum nf_nat_manip_type mtype
= HOOK2MANIP(hooknum
);
473 if (mtype
== NF_NAT_MANIP_SRC
)
474 statusbit
= IPS_SRC_NAT
;
476 statusbit
= IPS_DST_NAT
;
478 /* Invert if this is reply dir. */
479 if (dir
== IP_CT_DIR_REPLY
)
480 statusbit
^= IPS_NAT_MASK
;
482 /* Non-atomic: these bits don't change. */
483 if (ct
->status
& statusbit
) {
484 struct nf_conntrack_tuple target
;
486 /* We are aiming to look like inverse of other direction. */
487 nf_ct_invert_tuplepr(&target
, &ct
->tuplehash
[!dir
].tuple
);
489 l3proto
= __nf_nat_l3proto_find(target
.src
.l3num
);
490 l4proto
= __nf_nat_l4proto_find(target
.src
.l3num
,
491 target
.dst
.protonum
);
492 if (!l3proto
->manip_pkt(skb
, 0, l4proto
, &target
, mtype
))
497 EXPORT_SYMBOL_GPL(nf_nat_packet
);
499 struct nf_nat_proto_clean
{
504 /* kill conntracks with affected NAT section */
505 static int nf_nat_proto_remove(struct nf_conn
*i
, void *data
)
507 const struct nf_nat_proto_clean
*clean
= data
;
508 struct nf_conn_nat
*nat
= nfct_nat(i
);
513 if ((clean
->l3proto
&& nf_ct_l3num(i
) != clean
->l3proto
) ||
514 (clean
->l4proto
&& nf_ct_protonum(i
) != clean
->l4proto
))
517 return i
->status
& IPS_NAT_MASK
? 1 : 0;
520 static void nf_nat_l4proto_clean(u8 l3proto
, u8 l4proto
)
522 struct nf_nat_proto_clean clean
= {
530 nf_ct_iterate_cleanup(net
, nf_nat_proto_remove
, &clean
, 0, 0);
534 static void nf_nat_l3proto_clean(u8 l3proto
)
536 struct nf_nat_proto_clean clean
= {
544 nf_ct_iterate_cleanup(net
, nf_nat_proto_remove
, &clean
, 0, 0);
548 /* Protocol registration. */
549 int nf_nat_l4proto_register(u8 l3proto
, const struct nf_nat_l4proto
*l4proto
)
551 const struct nf_nat_l4proto
**l4protos
;
555 mutex_lock(&nf_nat_proto_mutex
);
556 if (nf_nat_l4protos
[l3proto
] == NULL
) {
557 l4protos
= kmalloc(IPPROTO_MAX
* sizeof(struct nf_nat_l4proto
*),
559 if (l4protos
== NULL
) {
564 for (i
= 0; i
< IPPROTO_MAX
; i
++)
565 RCU_INIT_POINTER(l4protos
[i
], &nf_nat_l4proto_unknown
);
567 /* Before making proto_array visible to lockless readers,
568 * we must make sure its content is committed to memory.
572 nf_nat_l4protos
[l3proto
] = l4protos
;
575 if (rcu_dereference_protected(
576 nf_nat_l4protos
[l3proto
][l4proto
->l4proto
],
577 lockdep_is_held(&nf_nat_proto_mutex
)
578 ) != &nf_nat_l4proto_unknown
) {
582 RCU_INIT_POINTER(nf_nat_l4protos
[l3proto
][l4proto
->l4proto
], l4proto
);
584 mutex_unlock(&nf_nat_proto_mutex
);
587 EXPORT_SYMBOL_GPL(nf_nat_l4proto_register
);
589 /* No one stores the protocol anywhere; simply delete it. */
590 void nf_nat_l4proto_unregister(u8 l3proto
, const struct nf_nat_l4proto
*l4proto
)
592 mutex_lock(&nf_nat_proto_mutex
);
593 RCU_INIT_POINTER(nf_nat_l4protos
[l3proto
][l4proto
->l4proto
],
594 &nf_nat_l4proto_unknown
);
595 mutex_unlock(&nf_nat_proto_mutex
);
598 nf_nat_l4proto_clean(l3proto
, l4proto
->l4proto
);
600 EXPORT_SYMBOL_GPL(nf_nat_l4proto_unregister
);
602 int nf_nat_l3proto_register(const struct nf_nat_l3proto
*l3proto
)
606 err
= nf_ct_l3proto_try_module_get(l3proto
->l3proto
);
610 mutex_lock(&nf_nat_proto_mutex
);
611 RCU_INIT_POINTER(nf_nat_l4protos
[l3proto
->l3proto
][IPPROTO_TCP
],
612 &nf_nat_l4proto_tcp
);
613 RCU_INIT_POINTER(nf_nat_l4protos
[l3proto
->l3proto
][IPPROTO_UDP
],
614 &nf_nat_l4proto_udp
);
615 mutex_unlock(&nf_nat_proto_mutex
);
617 RCU_INIT_POINTER(nf_nat_l3protos
[l3proto
->l3proto
], l3proto
);
620 EXPORT_SYMBOL_GPL(nf_nat_l3proto_register
);
622 void nf_nat_l3proto_unregister(const struct nf_nat_l3proto
*l3proto
)
624 mutex_lock(&nf_nat_proto_mutex
);
625 RCU_INIT_POINTER(nf_nat_l3protos
[l3proto
->l3proto
], NULL
);
626 mutex_unlock(&nf_nat_proto_mutex
);
629 nf_nat_l3proto_clean(l3proto
->l3proto
);
630 nf_ct_l3proto_module_put(l3proto
->l3proto
);
632 EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister
);
634 /* No one using conntrack by the time this called. */
635 static void nf_nat_cleanup_conntrack(struct nf_conn
*ct
)
637 struct nf_conn_nat
*nat
= nf_ct_ext_find(ct
, NF_CT_EXT_NAT
);
639 if (nat
== NULL
|| nat
->ct
== NULL
)
642 NF_CT_ASSERT(nat
->ct
->status
& IPS_SRC_NAT_DONE
);
644 spin_lock_bh(&nf_nat_lock
);
645 hlist_del_rcu(&nat
->bysource
);
646 spin_unlock_bh(&nf_nat_lock
);
649 static void nf_nat_move_storage(void *new, void *old
)
651 struct nf_conn_nat
*new_nat
= new;
652 struct nf_conn_nat
*old_nat
= old
;
653 struct nf_conn
*ct
= old_nat
->ct
;
655 if (!ct
|| !(ct
->status
& IPS_SRC_NAT_DONE
))
658 spin_lock_bh(&nf_nat_lock
);
659 hlist_replace_rcu(&old_nat
->bysource
, &new_nat
->bysource
);
660 spin_unlock_bh(&nf_nat_lock
);
663 static struct nf_ct_ext_type nat_extend __read_mostly
= {
664 .len
= sizeof(struct nf_conn_nat
),
665 .align
= __alignof__(struct nf_conn_nat
),
666 .destroy
= nf_nat_cleanup_conntrack
,
667 .move
= nf_nat_move_storage
,
669 .flags
= NF_CT_EXT_F_PREALLOC
,
672 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
674 #include <linux/netfilter/nfnetlink.h>
675 #include <linux/netfilter/nfnetlink_conntrack.h>
677 static const struct nla_policy protonat_nla_policy
[CTA_PROTONAT_MAX
+1] = {
678 [CTA_PROTONAT_PORT_MIN
] = { .type
= NLA_U16
},
679 [CTA_PROTONAT_PORT_MAX
] = { .type
= NLA_U16
},
682 static int nfnetlink_parse_nat_proto(struct nlattr
*attr
,
683 const struct nf_conn
*ct
,
684 struct nf_nat_range
*range
)
686 struct nlattr
*tb
[CTA_PROTONAT_MAX
+1];
687 const struct nf_nat_l4proto
*l4proto
;
690 err
= nla_parse_nested(tb
, CTA_PROTONAT_MAX
, attr
, protonat_nla_policy
);
694 l4proto
= __nf_nat_l4proto_find(nf_ct_l3num(ct
), nf_ct_protonum(ct
));
695 if (l4proto
->nlattr_to_range
)
696 err
= l4proto
->nlattr_to_range(tb
, range
);
701 static const struct nla_policy nat_nla_policy
[CTA_NAT_MAX
+1] = {
702 [CTA_NAT_V4_MINIP
] = { .type
= NLA_U32
},
703 [CTA_NAT_V4_MAXIP
] = { .type
= NLA_U32
},
704 [CTA_NAT_V6_MINIP
] = { .len
= sizeof(struct in6_addr
) },
705 [CTA_NAT_V6_MAXIP
] = { .len
= sizeof(struct in6_addr
) },
706 [CTA_NAT_PROTO
] = { .type
= NLA_NESTED
},
710 nfnetlink_parse_nat(const struct nlattr
*nat
,
711 const struct nf_conn
*ct
, struct nf_nat_range
*range
,
712 const struct nf_nat_l3proto
*l3proto
)
714 struct nlattr
*tb
[CTA_NAT_MAX
+1];
717 memset(range
, 0, sizeof(*range
));
719 err
= nla_parse_nested(tb
, CTA_NAT_MAX
, nat
, nat_nla_policy
);
723 err
= l3proto
->nlattr_to_range(tb
, range
);
727 if (!tb
[CTA_NAT_PROTO
])
730 return nfnetlink_parse_nat_proto(tb
[CTA_NAT_PROTO
], ct
, range
);
733 /* This function is called under rcu_read_lock() */
735 nfnetlink_parse_nat_setup(struct nf_conn
*ct
,
736 enum nf_nat_manip_type manip
,
737 const struct nlattr
*attr
)
739 struct nf_nat_range range
;
740 const struct nf_nat_l3proto
*l3proto
;
743 /* Should not happen, restricted to creating new conntracks
746 if (WARN_ON_ONCE(nf_nat_initialized(ct
, manip
)))
749 /* Make sure that L3 NAT is there by when we call nf_nat_setup_info to
750 * attach the null binding, otherwise this may oops.
752 l3proto
= __nf_nat_l3proto_find(nf_ct_l3num(ct
));
756 /* No NAT information has been passed, allocate the null-binding */
758 return __nf_nat_alloc_null_binding(ct
, manip
);
760 err
= nfnetlink_parse_nat(attr
, ct
, &range
, l3proto
);
764 return nf_nat_setup_info(ct
, &range
, manip
);
768 nfnetlink_parse_nat_setup(struct nf_conn
*ct
,
769 enum nf_nat_manip_type manip
,
770 const struct nlattr
*attr
)
776 static int __net_init
nf_nat_net_init(struct net
*net
)
778 /* Leave them the same for the moment. */
779 net
->ct
.nat_htable_size
= net
->ct
.htable_size
;
780 net
->ct
.nat_bysource
= nf_ct_alloc_hashtable(&net
->ct
.nat_htable_size
, 0);
781 if (!net
->ct
.nat_bysource
)
786 static void __net_exit
nf_nat_net_exit(struct net
*net
)
788 struct nf_nat_proto_clean clean
= {};
790 nf_ct_iterate_cleanup(net
, &nf_nat_proto_remove
, &clean
, 0, 0);
792 nf_ct_free_hashtable(net
->ct
.nat_bysource
, net
->ct
.nat_htable_size
);
795 static struct pernet_operations nf_nat_net_ops
= {
796 .init
= nf_nat_net_init
,
797 .exit
= nf_nat_net_exit
,
800 static struct nf_ct_helper_expectfn follow_master_nat
= {
801 .name
= "nat-follow-master",
802 .expectfn
= nf_nat_follow_master
,
805 static int __init
nf_nat_init(void)
809 ret
= nf_ct_extend_register(&nat_extend
);
811 printk(KERN_ERR
"nf_nat_core: Unable to register extension\n");
815 ret
= register_pernet_subsys(&nf_nat_net_ops
);
819 nf_ct_helper_expectfn_register(&follow_master_nat
);
821 /* Initialize fake conntrack so that NAT will skip it */
822 nf_ct_untracked_status_or(IPS_NAT_DONE_MASK
);
824 BUG_ON(nfnetlink_parse_nat_setup_hook
!= NULL
);
825 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook
,
826 nfnetlink_parse_nat_setup
);
828 BUG_ON(nf_nat_decode_session_hook
!= NULL
);
829 RCU_INIT_POINTER(nf_nat_decode_session_hook
, __nf_nat_decode_session
);
834 nf_ct_extend_unregister(&nat_extend
);
838 static void __exit
nf_nat_cleanup(void)
842 unregister_pernet_subsys(&nf_nat_net_ops
);
843 nf_ct_extend_unregister(&nat_extend
);
844 nf_ct_helper_expectfn_unregister(&follow_master_nat
);
845 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook
, NULL
);
847 RCU_INIT_POINTER(nf_nat_decode_session_hook
, NULL
);
849 for (i
= 0; i
< NFPROTO_NUMPROTO
; i
++)
850 kfree(nf_nat_l4protos
[i
]);
854 MODULE_LICENSE("GPL");
856 module_init(nf_nat_init
);
857 module_exit(nf_nat_cleanup
);