1 /* NAT for netfilter; shared with compatibility layer. */
3 /* (C) 1999-2001 Paul `Rusty' Russell
4 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
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>
16 #include <net/checksum.h>
19 #include <net/tcp.h> /* For tcp_prot in getorigdst */
20 #include <linux/icmp.h>
21 #include <linux/udp.h>
22 #include <linux/jhash.h>
24 #include <linux/netfilter_ipv4.h>
25 #include <net/netfilter/nf_conntrack.h>
26 #include <net/netfilter/nf_conntrack_core.h>
27 #include <net/netfilter/nf_nat.h>
28 #include <net/netfilter/nf_nat_protocol.h>
29 #include <net/netfilter/nf_nat_core.h>
30 #include <net/netfilter/nf_nat_helper.h>
31 #include <net/netfilter/nf_conntrack_helper.h>
32 #include <net/netfilter/nf_conntrack_l3proto.h>
33 #include <net/netfilter/nf_conntrack_l4proto.h>
34 #include <net/netfilter/nf_conntrack_zones.h>
36 static DEFINE_SPINLOCK(nf_nat_lock
);
38 static struct nf_conntrack_l3proto
*l3proto __read_mostly
;
40 #define MAX_IP_NAT_PROTO 256
41 static const struct nf_nat_protocol __rcu
*nf_nat_protos
[MAX_IP_NAT_PROTO
]
44 static inline const struct nf_nat_protocol
*
45 __nf_nat_proto_find(u_int8_t protonum
)
47 return rcu_dereference(nf_nat_protos
[protonum
]);
50 /* We keep an extra hash for each conntrack, for fast searching. */
51 static inline unsigned int
52 hash_by_src(const struct net
*net
, u16 zone
,
53 const struct nf_conntrack_tuple
*tuple
)
57 /* Original src, to ensure we map it consistently if poss. */
58 hash
= jhash_3words((__force u32
)tuple
->src
.u3
.ip
,
59 (__force u32
)tuple
->src
.u
.all
^ zone
,
60 tuple
->dst
.protonum
, 0);
61 return ((u64
)hash
* net
->ipv4
.nat_htable_size
) >> 32;
64 /* Is this tuple already taken? (not by us) */
66 nf_nat_used_tuple(const struct nf_conntrack_tuple
*tuple
,
67 const struct nf_conn
*ignored_conntrack
)
69 /* Conntrack tracking doesn't keep track of outgoing tuples; only
70 incoming ones. NAT means they don't have a fixed mapping,
71 so we invert the tuple and look for the incoming reply.
73 We could keep a separate hash if this proves too slow. */
74 struct nf_conntrack_tuple reply
;
76 nf_ct_invert_tuplepr(&reply
, tuple
);
77 return nf_conntrack_tuple_taken(&reply
, ignored_conntrack
);
79 EXPORT_SYMBOL(nf_nat_used_tuple
);
81 /* If we source map this tuple so reply looks like reply_tuple, will
82 * that meet the constraints of range. */
84 in_range(const struct nf_conntrack_tuple
*tuple
,
85 const struct nf_nat_range
*range
)
87 const struct nf_nat_protocol
*proto
;
90 /* If we are supposed to map IPs, then we must be in the
91 range specified, otherwise let this drag us onto a new src IP. */
92 if (range
->flags
& IP_NAT_RANGE_MAP_IPS
) {
93 if (ntohl(tuple
->src
.u3
.ip
) < ntohl(range
->min_ip
) ||
94 ntohl(tuple
->src
.u3
.ip
) > ntohl(range
->max_ip
))
99 proto
= __nf_nat_proto_find(tuple
->dst
.protonum
);
100 if (!(range
->flags
& IP_NAT_RANGE_PROTO_SPECIFIED
) ||
101 proto
->in_range(tuple
, IP_NAT_MANIP_SRC
,
102 &range
->min
, &range
->max
))
110 same_src(const struct nf_conn
*ct
,
111 const struct nf_conntrack_tuple
*tuple
)
113 const struct nf_conntrack_tuple
*t
;
115 t
= &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
;
116 return (t
->dst
.protonum
== tuple
->dst
.protonum
&&
117 t
->src
.u3
.ip
== tuple
->src
.u3
.ip
&&
118 t
->src
.u
.all
== tuple
->src
.u
.all
);
121 /* Only called for SRC manip */
123 find_appropriate_src(struct net
*net
, u16 zone
,
124 const struct nf_conntrack_tuple
*tuple
,
125 struct nf_conntrack_tuple
*result
,
126 const struct nf_nat_range
*range
)
128 unsigned int h
= hash_by_src(net
, zone
, tuple
);
129 const struct nf_conn_nat
*nat
;
130 const struct nf_conn
*ct
;
131 const struct hlist_node
*n
;
134 hlist_for_each_entry_rcu(nat
, n
, &net
->ipv4
.nat_bysource
[h
], bysource
) {
136 if (same_src(ct
, tuple
) && nf_ct_zone(ct
) == zone
) {
137 /* Copy source part from reply tuple. */
138 nf_ct_invert_tuplepr(result
,
139 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
140 result
->dst
= tuple
->dst
;
142 if (in_range(result
, range
)) {
152 /* For [FUTURE] fragmentation handling, we want the least-used
153 src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus
154 if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
155 1-65535, we don't do pro-rata allocation based on ports; we choose
156 the ip with the lowest src-ip/dst-ip/proto usage.
159 find_best_ips_proto(u16 zone
, struct nf_conntrack_tuple
*tuple
,
160 const struct nf_nat_range
*range
,
161 const struct nf_conn
*ct
,
162 enum nf_nat_manip_type maniptype
)
166 u_int32_t minip
, maxip
, j
;
168 /* No IP mapping? Do nothing. */
169 if (!(range
->flags
& IP_NAT_RANGE_MAP_IPS
))
172 if (maniptype
== IP_NAT_MANIP_SRC
)
173 var_ipp
= &tuple
->src
.u3
.ip
;
175 var_ipp
= &tuple
->dst
.u3
.ip
;
177 /* Fast path: only one choice. */
178 if (range
->min_ip
== range
->max_ip
) {
179 *var_ipp
= range
->min_ip
;
183 /* Hashing source and destination IPs gives a fairly even
184 * spread in practice (if there are a small number of IPs
185 * involved, there usually aren't that many connections
186 * anyway). The consistency means that servers see the same
187 * client coming from the same IP (some Internet Banking sites
188 * like this), even across reboots. */
189 minip
= ntohl(range
->min_ip
);
190 maxip
= ntohl(range
->max_ip
);
191 j
= jhash_2words((__force u32
)tuple
->src
.u3
.ip
,
192 range
->flags
& IP_NAT_RANGE_PERSISTENT
?
193 0 : (__force u32
)tuple
->dst
.u3
.ip
^ zone
, 0);
194 j
= ((u64
)j
* (maxip
- minip
+ 1)) >> 32;
195 *var_ipp
= htonl(minip
+ j
);
198 /* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
199 * we change the source to map into the range. For NF_INET_PRE_ROUTING
200 * and NF_INET_LOCAL_OUT, we change the destination to map into the
201 * range. It might not be possible to get a unique tuple, but we try.
202 * At worst (or if we race), we will end up with a final duplicate in
203 * __ip_conntrack_confirm and drop the packet. */
205 get_unique_tuple(struct nf_conntrack_tuple
*tuple
,
206 const struct nf_conntrack_tuple
*orig_tuple
,
207 const struct nf_nat_range
*range
,
209 enum nf_nat_manip_type maniptype
)
211 struct net
*net
= nf_ct_net(ct
);
212 const struct nf_nat_protocol
*proto
;
213 u16 zone
= nf_ct_zone(ct
);
215 /* 1) If this srcip/proto/src-proto-part is currently mapped,
216 and that same mapping gives a unique tuple within the given
219 This is only required for source (ie. NAT/masq) mappings.
220 So far, we don't do local source mappings, so multiple
221 manips not an issue. */
222 if (maniptype
== IP_NAT_MANIP_SRC
&&
223 !(range
->flags
& IP_NAT_RANGE_PROTO_RANDOM
)) {
224 if (find_appropriate_src(net
, zone
, orig_tuple
, tuple
, range
)) {
225 pr_debug("get_unique_tuple: Found current src map\n");
226 if (!nf_nat_used_tuple(tuple
, ct
))
231 /* 2) Select the least-used IP/proto combination in the given
233 *tuple
= *orig_tuple
;
234 find_best_ips_proto(zone
, tuple
, range
, ct
, maniptype
);
236 /* 3) The per-protocol part of the manip is made to map into
237 the range to make a unique tuple. */
240 proto
= __nf_nat_proto_find(orig_tuple
->dst
.protonum
);
242 /* Only bother mapping if it's not already in range and unique */
243 if (!(range
->flags
& IP_NAT_RANGE_PROTO_RANDOM
)) {
244 if (range
->flags
& IP_NAT_RANGE_PROTO_SPECIFIED
) {
245 if (proto
->in_range(tuple
, maniptype
, &range
->min
,
247 (range
->min
.all
== range
->max
.all
||
248 !nf_nat_used_tuple(tuple
, ct
)))
250 } else if (!nf_nat_used_tuple(tuple
, ct
)) {
255 /* Last change: get protocol to try to obtain unique tuple. */
256 proto
->unique_tuple(tuple
, range
, maniptype
, ct
);
262 nf_nat_setup_info(struct nf_conn
*ct
,
263 const struct nf_nat_range
*range
,
264 enum nf_nat_manip_type maniptype
)
266 struct net
*net
= nf_ct_net(ct
);
267 struct nf_conntrack_tuple curr_tuple
, new_tuple
;
268 struct nf_conn_nat
*nat
;
269 int have_to_hash
= !(ct
->status
& IPS_NAT_DONE_MASK
);
271 /* nat helper or nfctnetlink also setup binding */
274 nat
= nf_ct_ext_add(ct
, NF_CT_EXT_NAT
, GFP_ATOMIC
);
276 pr_debug("failed to add NAT extension\n");
281 NF_CT_ASSERT(maniptype
== IP_NAT_MANIP_SRC
||
282 maniptype
== IP_NAT_MANIP_DST
);
283 BUG_ON(nf_nat_initialized(ct
, maniptype
));
285 /* What we've got will look like inverse of reply. Normally
286 this is what is in the conntrack, except for prior
287 manipulations (future optimization: if num_manips == 0,
289 conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple) */
290 nf_ct_invert_tuplepr(&curr_tuple
,
291 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
293 get_unique_tuple(&new_tuple
, &curr_tuple
, range
, ct
, maniptype
);
295 if (!nf_ct_tuple_equal(&new_tuple
, &curr_tuple
)) {
296 struct nf_conntrack_tuple reply
;
298 /* Alter conntrack table so will recognize replies. */
299 nf_ct_invert_tuplepr(&reply
, &new_tuple
);
300 nf_conntrack_alter_reply(ct
, &reply
);
302 /* Non-atomic: we own this at the moment. */
303 if (maniptype
== IP_NAT_MANIP_SRC
)
304 ct
->status
|= IPS_SRC_NAT
;
306 ct
->status
|= IPS_DST_NAT
;
309 /* Place in source hash if this is the first time. */
311 unsigned int srchash
;
313 srchash
= hash_by_src(net
, nf_ct_zone(ct
),
314 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
315 spin_lock_bh(&nf_nat_lock
);
316 /* nf_conntrack_alter_reply might re-allocate exntension aera */
319 hlist_add_head_rcu(&nat
->bysource
,
320 &net
->ipv4
.nat_bysource
[srchash
]);
321 spin_unlock_bh(&nf_nat_lock
);
325 if (maniptype
== IP_NAT_MANIP_DST
)
326 set_bit(IPS_DST_NAT_DONE_BIT
, &ct
->status
);
328 set_bit(IPS_SRC_NAT_DONE_BIT
, &ct
->status
);
332 EXPORT_SYMBOL(nf_nat_setup_info
);
334 /* Returns true if succeeded. */
336 manip_pkt(u_int16_t proto
,
338 unsigned int iphdroff
,
339 const struct nf_conntrack_tuple
*target
,
340 enum nf_nat_manip_type maniptype
)
343 const struct nf_nat_protocol
*p
;
345 if (!skb_make_writable(skb
, iphdroff
+ sizeof(*iph
)))
348 iph
= (void *)skb
->data
+ iphdroff
;
350 /* Manipulate protcol part. */
352 /* rcu_read_lock()ed by nf_hook_slow */
353 p
= __nf_nat_proto_find(proto
);
354 if (!p
->manip_pkt(skb
, iphdroff
, target
, maniptype
))
357 iph
= (void *)skb
->data
+ iphdroff
;
359 if (maniptype
== IP_NAT_MANIP_SRC
) {
360 csum_replace4(&iph
->check
, iph
->saddr
, target
->src
.u3
.ip
);
361 iph
->saddr
= target
->src
.u3
.ip
;
363 csum_replace4(&iph
->check
, iph
->daddr
, target
->dst
.u3
.ip
);
364 iph
->daddr
= target
->dst
.u3
.ip
;
369 /* Do packet manipulations according to nf_nat_setup_info. */
370 unsigned int nf_nat_packet(struct nf_conn
*ct
,
371 enum ip_conntrack_info ctinfo
,
372 unsigned int hooknum
,
375 enum ip_conntrack_dir dir
= CTINFO2DIR(ctinfo
);
376 unsigned long statusbit
;
377 enum nf_nat_manip_type mtype
= HOOK2MANIP(hooknum
);
379 if (mtype
== IP_NAT_MANIP_SRC
)
380 statusbit
= IPS_SRC_NAT
;
382 statusbit
= IPS_DST_NAT
;
384 /* Invert if this is reply dir. */
385 if (dir
== IP_CT_DIR_REPLY
)
386 statusbit
^= IPS_NAT_MASK
;
388 /* Non-atomic: these bits don't change. */
389 if (ct
->status
& statusbit
) {
390 struct nf_conntrack_tuple target
;
392 /* We are aiming to look like inverse of other direction. */
393 nf_ct_invert_tuplepr(&target
, &ct
->tuplehash
[!dir
].tuple
);
395 if (!manip_pkt(target
.dst
.protonum
, skb
, 0, &target
, mtype
))
400 EXPORT_SYMBOL_GPL(nf_nat_packet
);
402 /* Dir is direction ICMP is coming from (opposite to packet it contains) */
403 int nf_nat_icmp_reply_translation(struct nf_conn
*ct
,
404 enum ip_conntrack_info ctinfo
,
405 unsigned int hooknum
,
412 const struct nf_conntrack_l4proto
*l4proto
;
413 struct nf_conntrack_tuple inner
, target
;
414 int hdrlen
= ip_hdrlen(skb
);
415 enum ip_conntrack_dir dir
= CTINFO2DIR(ctinfo
);
416 unsigned long statusbit
;
417 enum nf_nat_manip_type manip
= HOOK2MANIP(hooknum
);
419 if (!skb_make_writable(skb
, hdrlen
+ sizeof(*inside
)))
422 inside
= (void *)skb
->data
+ hdrlen
;
424 /* We're actually going to mangle it beyond trivial checksum
425 adjustment, so make sure the current checksum is correct. */
426 if (nf_ip_checksum(skb
, hooknum
, hdrlen
, 0))
429 /* Must be RELATED */
430 NF_CT_ASSERT(skb
->nfctinfo
== IP_CT_RELATED
||
431 skb
->nfctinfo
== IP_CT_RELATED
+IP_CT_IS_REPLY
);
433 /* Redirects on non-null nats must be dropped, else they'll
434 start talking to each other without our translation, and be
436 if (inside
->icmp
.type
== ICMP_REDIRECT
) {
437 /* If NAT isn't finished, assume it and drop. */
438 if ((ct
->status
& IPS_NAT_DONE_MASK
) != IPS_NAT_DONE_MASK
)
441 if (ct
->status
& IPS_NAT_MASK
)
445 if (manip
== IP_NAT_MANIP_SRC
)
446 statusbit
= IPS_SRC_NAT
;
448 statusbit
= IPS_DST_NAT
;
450 /* Invert if this is reply dir. */
451 if (dir
== IP_CT_DIR_REPLY
)
452 statusbit
^= IPS_NAT_MASK
;
454 if (!(ct
->status
& statusbit
))
457 pr_debug("icmp_reply_translation: translating error %p manip %u "
458 "dir %s\n", skb
, manip
,
459 dir
== IP_CT_DIR_ORIGINAL
? "ORIG" : "REPLY");
461 /* rcu_read_lock()ed by nf_hook_slow */
462 l4proto
= __nf_ct_l4proto_find(PF_INET
, inside
->ip
.protocol
);
464 if (!nf_ct_get_tuple(skb
, hdrlen
+ sizeof(struct icmphdr
),
466 sizeof(struct icmphdr
) + inside
->ip
.ihl
* 4),
467 (u_int16_t
)AF_INET
, inside
->ip
.protocol
,
468 &inner
, l3proto
, l4proto
))
471 /* Change inner back to look like incoming packet. We do the
472 opposite manip on this hook to normal, because it might not
473 pass all hooks (locally-generated ICMP). Consider incoming
474 packet: PREROUTING (DST manip), routing produces ICMP, goes
475 through POSTROUTING (which must correct the DST manip). */
476 if (!manip_pkt(inside
->ip
.protocol
, skb
, hdrlen
+ sizeof(inside
->icmp
),
477 &ct
->tuplehash
[!dir
].tuple
, !manip
))
480 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
) {
481 /* Reloading "inside" here since manip_pkt inner. */
482 inside
= (void *)skb
->data
+ hdrlen
;
483 inside
->icmp
.checksum
= 0;
484 inside
->icmp
.checksum
=
485 csum_fold(skb_checksum(skb
, hdrlen
,
486 skb
->len
- hdrlen
, 0));
489 /* Change outer to look the reply to an incoming packet
490 * (proto 0 means don't invert per-proto part). */
491 nf_ct_invert_tuplepr(&target
, &ct
->tuplehash
[!dir
].tuple
);
492 if (!manip_pkt(0, skb
, 0, &target
, manip
))
497 EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation
);
499 /* Protocol registration. */
500 int nf_nat_protocol_register(const struct nf_nat_protocol
*proto
)
504 spin_lock_bh(&nf_nat_lock
);
505 if (nf_nat_protos
[proto
->protonum
] != &nf_nat_unknown_protocol
) {
509 rcu_assign_pointer(nf_nat_protos
[proto
->protonum
], proto
);
511 spin_unlock_bh(&nf_nat_lock
);
514 EXPORT_SYMBOL(nf_nat_protocol_register
);
516 /* Noone stores the protocol anywhere; simply delete it. */
517 void nf_nat_protocol_unregister(const struct nf_nat_protocol
*proto
)
519 spin_lock_bh(&nf_nat_lock
);
520 rcu_assign_pointer(nf_nat_protos
[proto
->protonum
],
521 &nf_nat_unknown_protocol
);
522 spin_unlock_bh(&nf_nat_lock
);
525 EXPORT_SYMBOL(nf_nat_protocol_unregister
);
527 /* Noone using conntrack by the time this called. */
528 static void nf_nat_cleanup_conntrack(struct nf_conn
*ct
)
530 struct nf_conn_nat
*nat
= nf_ct_ext_find(ct
, NF_CT_EXT_NAT
);
532 if (nat
== NULL
|| nat
->ct
== NULL
)
535 NF_CT_ASSERT(nat
->ct
->status
& IPS_NAT_DONE_MASK
);
537 spin_lock_bh(&nf_nat_lock
);
538 hlist_del_rcu(&nat
->bysource
);
539 spin_unlock_bh(&nf_nat_lock
);
542 static void nf_nat_move_storage(void *new, void *old
)
544 struct nf_conn_nat
*new_nat
= new;
545 struct nf_conn_nat
*old_nat
= old
;
546 struct nf_conn
*ct
= old_nat
->ct
;
548 if (!ct
|| !(ct
->status
& IPS_NAT_DONE_MASK
))
551 spin_lock_bh(&nf_nat_lock
);
553 hlist_replace_rcu(&old_nat
->bysource
, &new_nat
->bysource
);
554 spin_unlock_bh(&nf_nat_lock
);
557 static struct nf_ct_ext_type nat_extend __read_mostly
= {
558 .len
= sizeof(struct nf_conn_nat
),
559 .align
= __alignof__(struct nf_conn_nat
),
560 .destroy
= nf_nat_cleanup_conntrack
,
561 .move
= nf_nat_move_storage
,
563 .flags
= NF_CT_EXT_F_PREALLOC
,
566 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
568 #include <linux/netfilter/nfnetlink.h>
569 #include <linux/netfilter/nfnetlink_conntrack.h>
571 static const struct nf_nat_protocol
*
572 nf_nat_proto_find_get(u_int8_t protonum
)
574 const struct nf_nat_protocol
*p
;
577 p
= __nf_nat_proto_find(protonum
);
578 if (!try_module_get(p
->me
))
579 p
= &nf_nat_unknown_protocol
;
586 nf_nat_proto_put(const struct nf_nat_protocol
*p
)
591 static const struct nla_policy protonat_nla_policy
[CTA_PROTONAT_MAX
+1] = {
592 [CTA_PROTONAT_PORT_MIN
] = { .type
= NLA_U16
},
593 [CTA_PROTONAT_PORT_MAX
] = { .type
= NLA_U16
},
596 static int nfnetlink_parse_nat_proto(struct nlattr
*attr
,
597 const struct nf_conn
*ct
,
598 struct nf_nat_range
*range
)
600 struct nlattr
*tb
[CTA_PROTONAT_MAX
+1];
601 const struct nf_nat_protocol
*npt
;
604 err
= nla_parse_nested(tb
, CTA_PROTONAT_MAX
, attr
, protonat_nla_policy
);
608 npt
= nf_nat_proto_find_get(nf_ct_protonum(ct
));
609 if (npt
->nlattr_to_range
)
610 err
= npt
->nlattr_to_range(tb
, range
);
611 nf_nat_proto_put(npt
);
615 static const struct nla_policy nat_nla_policy
[CTA_NAT_MAX
+1] = {
616 [CTA_NAT_MINIP
] = { .type
= NLA_U32
},
617 [CTA_NAT_MAXIP
] = { .type
= NLA_U32
},
621 nfnetlink_parse_nat(const struct nlattr
*nat
,
622 const struct nf_conn
*ct
, struct nf_nat_range
*range
)
624 struct nlattr
*tb
[CTA_NAT_MAX
+1];
627 memset(range
, 0, sizeof(*range
));
629 err
= nla_parse_nested(tb
, CTA_NAT_MAX
, nat
, nat_nla_policy
);
633 if (tb
[CTA_NAT_MINIP
])
634 range
->min_ip
= nla_get_be32(tb
[CTA_NAT_MINIP
]);
636 if (!tb
[CTA_NAT_MAXIP
])
637 range
->max_ip
= range
->min_ip
;
639 range
->max_ip
= nla_get_be32(tb
[CTA_NAT_MAXIP
]);
642 range
->flags
|= IP_NAT_RANGE_MAP_IPS
;
644 if (!tb
[CTA_NAT_PROTO
])
647 err
= nfnetlink_parse_nat_proto(tb
[CTA_NAT_PROTO
], ct
, range
);
655 nfnetlink_parse_nat_setup(struct nf_conn
*ct
,
656 enum nf_nat_manip_type manip
,
657 const struct nlattr
*attr
)
659 struct nf_nat_range range
;
661 if (nfnetlink_parse_nat(attr
, ct
, &range
) < 0)
663 if (nf_nat_initialized(ct
, manip
))
666 return nf_nat_setup_info(ct
, &range
, manip
);
670 nfnetlink_parse_nat_setup(struct nf_conn
*ct
,
671 enum nf_nat_manip_type manip
,
672 const struct nlattr
*attr
)
678 static int __net_init
nf_nat_net_init(struct net
*net
)
680 /* Leave them the same for the moment. */
681 net
->ipv4
.nat_htable_size
= net
->ct
.htable_size
;
682 net
->ipv4
.nat_bysource
= nf_ct_alloc_hashtable(&net
->ipv4
.nat_htable_size
,
683 &net
->ipv4
.nat_vmalloced
, 0);
684 if (!net
->ipv4
.nat_bysource
)
689 /* Clear NAT section of all conntracks, in case we're loaded again. */
690 static int clean_nat(struct nf_conn
*i
, void *data
)
692 struct nf_conn_nat
*nat
= nfct_nat(i
);
696 memset(nat
, 0, sizeof(*nat
));
697 i
->status
&= ~(IPS_NAT_MASK
| IPS_NAT_DONE_MASK
| IPS_SEQ_ADJUST
);
701 static void __net_exit
nf_nat_net_exit(struct net
*net
)
703 nf_ct_iterate_cleanup(net
, &clean_nat
, NULL
);
705 nf_ct_free_hashtable(net
->ipv4
.nat_bysource
, net
->ipv4
.nat_vmalloced
,
706 net
->ipv4
.nat_htable_size
);
709 static struct pernet_operations nf_nat_net_ops
= {
710 .init
= nf_nat_net_init
,
711 .exit
= nf_nat_net_exit
,
714 static int __init
nf_nat_init(void)
719 need_ipv4_conntrack();
721 ret
= nf_ct_extend_register(&nat_extend
);
723 printk(KERN_ERR
"nf_nat_core: Unable to register extension\n");
727 ret
= register_pernet_subsys(&nf_nat_net_ops
);
731 /* Sew in builtin protocols. */
732 spin_lock_bh(&nf_nat_lock
);
733 for (i
= 0; i
< MAX_IP_NAT_PROTO
; i
++)
734 rcu_assign_pointer(nf_nat_protos
[i
], &nf_nat_unknown_protocol
);
735 rcu_assign_pointer(nf_nat_protos
[IPPROTO_TCP
], &nf_nat_protocol_tcp
);
736 rcu_assign_pointer(nf_nat_protos
[IPPROTO_UDP
], &nf_nat_protocol_udp
);
737 rcu_assign_pointer(nf_nat_protos
[IPPROTO_ICMP
], &nf_nat_protocol_icmp
);
738 spin_unlock_bh(&nf_nat_lock
);
740 /* Initialize fake conntrack so that NAT will skip it */
741 nf_ct_untracked_status_or(IPS_NAT_DONE_MASK
);
743 l3proto
= nf_ct_l3proto_find_get((u_int16_t
)AF_INET
);
745 BUG_ON(nf_nat_seq_adjust_hook
!= NULL
);
746 rcu_assign_pointer(nf_nat_seq_adjust_hook
, nf_nat_seq_adjust
);
747 BUG_ON(nfnetlink_parse_nat_setup_hook
!= NULL
);
748 rcu_assign_pointer(nfnetlink_parse_nat_setup_hook
,
749 nfnetlink_parse_nat_setup
);
750 BUG_ON(nf_ct_nat_offset
!= NULL
);
751 rcu_assign_pointer(nf_ct_nat_offset
, nf_nat_get_offset
);
755 nf_ct_extend_unregister(&nat_extend
);
759 static void __exit
nf_nat_cleanup(void)
761 unregister_pernet_subsys(&nf_nat_net_ops
);
762 nf_ct_l3proto_put(l3proto
);
763 nf_ct_extend_unregister(&nat_extend
);
764 rcu_assign_pointer(nf_nat_seq_adjust_hook
, NULL
);
765 rcu_assign_pointer(nfnetlink_parse_nat_setup_hook
, NULL
);
766 rcu_assign_pointer(nf_ct_nat_offset
, NULL
);
770 MODULE_LICENSE("GPL");
771 MODULE_ALIAS("nf-nat-ipv4");
773 module_init(nf_nat_init
);
774 module_exit(nf_nat_cleanup
);