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
, nf_conntrack_hash_rnd
);
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_ipv4_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
& NF_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
& NF_NAT_RANGE_PROTO_SPECIFIED
) ||
101 proto
->in_range(tuple
, NF_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_ipv4_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_ipv4_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
& NF_NAT_RANGE_MAP_IPS
))
172 if (maniptype
== NF_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
& NF_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_ipv4_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
== NF_NAT_MANIP_SRC
&&
223 !(range
->flags
& NF_NAT_RANGE_PROTO_RANDOM
)) {
224 /* try the original tuple first */
225 if (in_range(orig_tuple
, range
)) {
226 if (!nf_nat_used_tuple(orig_tuple
, ct
)) {
227 *tuple
= *orig_tuple
;
230 } else if (find_appropriate_src(net
, zone
, orig_tuple
, tuple
,
232 pr_debug("get_unique_tuple: Found current src map\n");
233 if (!nf_nat_used_tuple(tuple
, ct
))
238 /* 2) Select the least-used IP/proto combination in the given
240 *tuple
= *orig_tuple
;
241 find_best_ips_proto(zone
, tuple
, range
, ct
, maniptype
);
243 /* 3) The per-protocol part of the manip is made to map into
244 the range to make a unique tuple. */
247 proto
= __nf_nat_proto_find(orig_tuple
->dst
.protonum
);
249 /* Only bother mapping if it's not already in range and unique */
250 if (!(range
->flags
& NF_NAT_RANGE_PROTO_RANDOM
)) {
251 if (range
->flags
& NF_NAT_RANGE_PROTO_SPECIFIED
) {
252 if (proto
->in_range(tuple
, maniptype
, &range
->min
,
254 (range
->min
.all
== range
->max
.all
||
255 !nf_nat_used_tuple(tuple
, ct
)))
257 } else if (!nf_nat_used_tuple(tuple
, ct
)) {
262 /* Last change: get protocol to try to obtain unique tuple. */
263 proto
->unique_tuple(tuple
, range
, maniptype
, ct
);
269 nf_nat_setup_info(struct nf_conn
*ct
,
270 const struct nf_nat_ipv4_range
*range
,
271 enum nf_nat_manip_type maniptype
)
273 struct net
*net
= nf_ct_net(ct
);
274 struct nf_conntrack_tuple curr_tuple
, new_tuple
;
275 struct nf_conn_nat
*nat
;
277 /* nat helper or nfctnetlink also setup binding */
280 nat
= nf_ct_ext_add(ct
, NF_CT_EXT_NAT
, GFP_ATOMIC
);
282 pr_debug("failed to add NAT extension\n");
287 NF_CT_ASSERT(maniptype
== NF_NAT_MANIP_SRC
||
288 maniptype
== NF_NAT_MANIP_DST
);
289 BUG_ON(nf_nat_initialized(ct
, maniptype
));
291 /* What we've got will look like inverse of reply. Normally
292 this is what is in the conntrack, except for prior
293 manipulations (future optimization: if num_manips == 0,
295 conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple) */
296 nf_ct_invert_tuplepr(&curr_tuple
,
297 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
299 get_unique_tuple(&new_tuple
, &curr_tuple
, range
, ct
, maniptype
);
301 if (!nf_ct_tuple_equal(&new_tuple
, &curr_tuple
)) {
302 struct nf_conntrack_tuple reply
;
304 /* Alter conntrack table so will recognize replies. */
305 nf_ct_invert_tuplepr(&reply
, &new_tuple
);
306 nf_conntrack_alter_reply(ct
, &reply
);
308 /* Non-atomic: we own this at the moment. */
309 if (maniptype
== NF_NAT_MANIP_SRC
)
310 ct
->status
|= IPS_SRC_NAT
;
312 ct
->status
|= IPS_DST_NAT
;
315 if (maniptype
== NF_NAT_MANIP_SRC
) {
316 unsigned int srchash
;
318 srchash
= hash_by_src(net
, nf_ct_zone(ct
),
319 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
320 spin_lock_bh(&nf_nat_lock
);
321 /* nf_conntrack_alter_reply might re-allocate exntension aera */
324 hlist_add_head_rcu(&nat
->bysource
,
325 &net
->ipv4
.nat_bysource
[srchash
]);
326 spin_unlock_bh(&nf_nat_lock
);
330 if (maniptype
== NF_NAT_MANIP_DST
)
331 ct
->status
|= IPS_DST_NAT_DONE
;
333 ct
->status
|= IPS_SRC_NAT_DONE
;
337 EXPORT_SYMBOL(nf_nat_setup_info
);
339 /* Returns true if succeeded. */
341 manip_pkt(u_int16_t proto
,
343 unsigned int iphdroff
,
344 const struct nf_conntrack_tuple
*target
,
345 enum nf_nat_manip_type maniptype
)
348 const struct nf_nat_protocol
*p
;
350 if (!skb_make_writable(skb
, iphdroff
+ sizeof(*iph
)))
353 iph
= (void *)skb
->data
+ iphdroff
;
355 /* Manipulate protcol part. */
357 /* rcu_read_lock()ed by nf_hook_slow */
358 p
= __nf_nat_proto_find(proto
);
359 if (!p
->manip_pkt(skb
, iphdroff
, target
, maniptype
))
362 iph
= (void *)skb
->data
+ iphdroff
;
364 if (maniptype
== NF_NAT_MANIP_SRC
) {
365 csum_replace4(&iph
->check
, iph
->saddr
, target
->src
.u3
.ip
);
366 iph
->saddr
= target
->src
.u3
.ip
;
368 csum_replace4(&iph
->check
, iph
->daddr
, target
->dst
.u3
.ip
);
369 iph
->daddr
= target
->dst
.u3
.ip
;
374 /* Do packet manipulations according to nf_nat_setup_info. */
375 unsigned int nf_nat_packet(struct nf_conn
*ct
,
376 enum ip_conntrack_info ctinfo
,
377 unsigned int hooknum
,
380 enum ip_conntrack_dir dir
= CTINFO2DIR(ctinfo
);
381 unsigned long statusbit
;
382 enum nf_nat_manip_type mtype
= HOOK2MANIP(hooknum
);
384 if (mtype
== NF_NAT_MANIP_SRC
)
385 statusbit
= IPS_SRC_NAT
;
387 statusbit
= IPS_DST_NAT
;
389 /* Invert if this is reply dir. */
390 if (dir
== IP_CT_DIR_REPLY
)
391 statusbit
^= IPS_NAT_MASK
;
393 /* Non-atomic: these bits don't change. */
394 if (ct
->status
& statusbit
) {
395 struct nf_conntrack_tuple target
;
397 /* We are aiming to look like inverse of other direction. */
398 nf_ct_invert_tuplepr(&target
, &ct
->tuplehash
[!dir
].tuple
);
400 if (!manip_pkt(target
.dst
.protonum
, skb
, 0, &target
, mtype
))
405 EXPORT_SYMBOL_GPL(nf_nat_packet
);
407 /* Dir is direction ICMP is coming from (opposite to packet it contains) */
408 int nf_nat_icmp_reply_translation(struct nf_conn
*ct
,
409 enum ip_conntrack_info ctinfo
,
410 unsigned int hooknum
,
417 const struct nf_conntrack_l4proto
*l4proto
;
418 struct nf_conntrack_tuple inner
, target
;
419 int hdrlen
= ip_hdrlen(skb
);
420 enum ip_conntrack_dir dir
= CTINFO2DIR(ctinfo
);
421 unsigned long statusbit
;
422 enum nf_nat_manip_type manip
= HOOK2MANIP(hooknum
);
424 if (!skb_make_writable(skb
, hdrlen
+ sizeof(*inside
)))
427 inside
= (void *)skb
->data
+ hdrlen
;
429 /* We're actually going to mangle it beyond trivial checksum
430 adjustment, so make sure the current checksum is correct. */
431 if (nf_ip_checksum(skb
, hooknum
, hdrlen
, 0))
434 /* Must be RELATED */
435 NF_CT_ASSERT(skb
->nfctinfo
== IP_CT_RELATED
||
436 skb
->nfctinfo
== IP_CT_RELATED_REPLY
);
438 /* Redirects on non-null nats must be dropped, else they'll
439 start talking to each other without our translation, and be
441 if (inside
->icmp
.type
== ICMP_REDIRECT
) {
442 /* If NAT isn't finished, assume it and drop. */
443 if ((ct
->status
& IPS_NAT_DONE_MASK
) != IPS_NAT_DONE_MASK
)
446 if (ct
->status
& IPS_NAT_MASK
)
450 if (manip
== NF_NAT_MANIP_SRC
)
451 statusbit
= IPS_SRC_NAT
;
453 statusbit
= IPS_DST_NAT
;
455 /* Invert if this is reply dir. */
456 if (dir
== IP_CT_DIR_REPLY
)
457 statusbit
^= IPS_NAT_MASK
;
459 if (!(ct
->status
& statusbit
))
462 pr_debug("icmp_reply_translation: translating error %p manip %u "
463 "dir %s\n", skb
, manip
,
464 dir
== IP_CT_DIR_ORIGINAL
? "ORIG" : "REPLY");
466 /* rcu_read_lock()ed by nf_hook_slow */
467 l4proto
= __nf_ct_l4proto_find(PF_INET
, inside
->ip
.protocol
);
469 if (!nf_ct_get_tuple(skb
, hdrlen
+ sizeof(struct icmphdr
),
471 sizeof(struct icmphdr
) + inside
->ip
.ihl
* 4),
472 (u_int16_t
)AF_INET
, inside
->ip
.protocol
,
473 &inner
, l3proto
, l4proto
))
476 /* Change inner back to look like incoming packet. We do the
477 opposite manip on this hook to normal, because it might not
478 pass all hooks (locally-generated ICMP). Consider incoming
479 packet: PREROUTING (DST manip), routing produces ICMP, goes
480 through POSTROUTING (which must correct the DST manip). */
481 if (!manip_pkt(inside
->ip
.protocol
, skb
, hdrlen
+ sizeof(inside
->icmp
),
482 &ct
->tuplehash
[!dir
].tuple
, !manip
))
485 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
) {
486 /* Reloading "inside" here since manip_pkt inner. */
487 inside
= (void *)skb
->data
+ hdrlen
;
488 inside
->icmp
.checksum
= 0;
489 inside
->icmp
.checksum
=
490 csum_fold(skb_checksum(skb
, hdrlen
,
491 skb
->len
- hdrlen
, 0));
494 /* Change outer to look the reply to an incoming packet
495 * (proto 0 means don't invert per-proto part). */
496 nf_ct_invert_tuplepr(&target
, &ct
->tuplehash
[!dir
].tuple
);
497 if (!manip_pkt(0, skb
, 0, &target
, manip
))
502 EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation
);
504 /* Protocol registration. */
505 int nf_nat_protocol_register(const struct nf_nat_protocol
*proto
)
509 spin_lock_bh(&nf_nat_lock
);
510 if (rcu_dereference_protected(
511 nf_nat_protos
[proto
->protonum
],
512 lockdep_is_held(&nf_nat_lock
)
513 ) != &nf_nat_unknown_protocol
) {
517 RCU_INIT_POINTER(nf_nat_protos
[proto
->protonum
], proto
);
519 spin_unlock_bh(&nf_nat_lock
);
522 EXPORT_SYMBOL(nf_nat_protocol_register
);
524 /* No one stores the protocol anywhere; simply delete it. */
525 void nf_nat_protocol_unregister(const struct nf_nat_protocol
*proto
)
527 spin_lock_bh(&nf_nat_lock
);
528 RCU_INIT_POINTER(nf_nat_protos
[proto
->protonum
],
529 &nf_nat_unknown_protocol
);
530 spin_unlock_bh(&nf_nat_lock
);
533 EXPORT_SYMBOL(nf_nat_protocol_unregister
);
535 /* No one using conntrack by the time this called. */
536 static void nf_nat_cleanup_conntrack(struct nf_conn
*ct
)
538 struct nf_conn_nat
*nat
= nf_ct_ext_find(ct
, NF_CT_EXT_NAT
);
540 if (nat
== NULL
|| nat
->ct
== NULL
)
543 NF_CT_ASSERT(nat
->ct
->status
& IPS_SRC_NAT_DONE
);
545 spin_lock_bh(&nf_nat_lock
);
546 hlist_del_rcu(&nat
->bysource
);
547 spin_unlock_bh(&nf_nat_lock
);
550 static void nf_nat_move_storage(void *new, void *old
)
552 struct nf_conn_nat
*new_nat
= new;
553 struct nf_conn_nat
*old_nat
= old
;
554 struct nf_conn
*ct
= old_nat
->ct
;
556 if (!ct
|| !(ct
->status
& IPS_SRC_NAT_DONE
))
559 spin_lock_bh(&nf_nat_lock
);
560 hlist_replace_rcu(&old_nat
->bysource
, &new_nat
->bysource
);
561 spin_unlock_bh(&nf_nat_lock
);
564 static struct nf_ct_ext_type nat_extend __read_mostly
= {
565 .len
= sizeof(struct nf_conn_nat
),
566 .align
= __alignof__(struct nf_conn_nat
),
567 .destroy
= nf_nat_cleanup_conntrack
,
568 .move
= nf_nat_move_storage
,
570 .flags
= NF_CT_EXT_F_PREALLOC
,
573 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
575 #include <linux/netfilter/nfnetlink.h>
576 #include <linux/netfilter/nfnetlink_conntrack.h>
578 static const struct nf_nat_protocol
*
579 nf_nat_proto_find_get(u_int8_t protonum
)
581 const struct nf_nat_protocol
*p
;
584 p
= __nf_nat_proto_find(protonum
);
585 if (!try_module_get(p
->me
))
586 p
= &nf_nat_unknown_protocol
;
593 nf_nat_proto_put(const struct nf_nat_protocol
*p
)
598 static const struct nla_policy protonat_nla_policy
[CTA_PROTONAT_MAX
+1] = {
599 [CTA_PROTONAT_PORT_MIN
] = { .type
= NLA_U16
},
600 [CTA_PROTONAT_PORT_MAX
] = { .type
= NLA_U16
},
603 static int nfnetlink_parse_nat_proto(struct nlattr
*attr
,
604 const struct nf_conn
*ct
,
605 struct nf_nat_ipv4_range
*range
)
607 struct nlattr
*tb
[CTA_PROTONAT_MAX
+1];
608 const struct nf_nat_protocol
*npt
;
611 err
= nla_parse_nested(tb
, CTA_PROTONAT_MAX
, attr
, protonat_nla_policy
);
615 npt
= nf_nat_proto_find_get(nf_ct_protonum(ct
));
616 if (npt
->nlattr_to_range
)
617 err
= npt
->nlattr_to_range(tb
, range
);
618 nf_nat_proto_put(npt
);
622 static const struct nla_policy nat_nla_policy
[CTA_NAT_MAX
+1] = {
623 [CTA_NAT_MINIP
] = { .type
= NLA_U32
},
624 [CTA_NAT_MAXIP
] = { .type
= NLA_U32
},
628 nfnetlink_parse_nat(const struct nlattr
*nat
,
629 const struct nf_conn
*ct
, struct nf_nat_ipv4_range
*range
)
631 struct nlattr
*tb
[CTA_NAT_MAX
+1];
634 memset(range
, 0, sizeof(*range
));
636 err
= nla_parse_nested(tb
, CTA_NAT_MAX
, nat
, nat_nla_policy
);
640 if (tb
[CTA_NAT_MINIP
])
641 range
->min_ip
= nla_get_be32(tb
[CTA_NAT_MINIP
]);
643 if (!tb
[CTA_NAT_MAXIP
])
644 range
->max_ip
= range
->min_ip
;
646 range
->max_ip
= nla_get_be32(tb
[CTA_NAT_MAXIP
]);
649 range
->flags
|= NF_NAT_RANGE_MAP_IPS
;
651 if (!tb
[CTA_NAT_PROTO
])
654 err
= nfnetlink_parse_nat_proto(tb
[CTA_NAT_PROTO
], ct
, range
);
662 nfnetlink_parse_nat_setup(struct nf_conn
*ct
,
663 enum nf_nat_manip_type manip
,
664 const struct nlattr
*attr
)
666 struct nf_nat_ipv4_range range
;
668 if (nfnetlink_parse_nat(attr
, ct
, &range
) < 0)
670 if (nf_nat_initialized(ct
, manip
))
673 return nf_nat_setup_info(ct
, &range
, manip
);
677 nfnetlink_parse_nat_setup(struct nf_conn
*ct
,
678 enum nf_nat_manip_type manip
,
679 const struct nlattr
*attr
)
685 static int __net_init
nf_nat_net_init(struct net
*net
)
687 /* Leave them the same for the moment. */
688 net
->ipv4
.nat_htable_size
= net
->ct
.htable_size
;
689 net
->ipv4
.nat_bysource
= nf_ct_alloc_hashtable(&net
->ipv4
.nat_htable_size
, 0);
690 if (!net
->ipv4
.nat_bysource
)
695 /* Clear NAT section of all conntracks, in case we're loaded again. */
696 static int clean_nat(struct nf_conn
*i
, void *data
)
698 struct nf_conn_nat
*nat
= nfct_nat(i
);
702 memset(nat
, 0, sizeof(*nat
));
703 i
->status
&= ~(IPS_NAT_MASK
| IPS_NAT_DONE_MASK
| IPS_SEQ_ADJUST
);
707 static void __net_exit
nf_nat_net_exit(struct net
*net
)
709 nf_ct_iterate_cleanup(net
, &clean_nat
, NULL
);
711 nf_ct_free_hashtable(net
->ipv4
.nat_bysource
, net
->ipv4
.nat_htable_size
);
714 static struct pernet_operations nf_nat_net_ops
= {
715 .init
= nf_nat_net_init
,
716 .exit
= nf_nat_net_exit
,
719 static int __init
nf_nat_init(void)
724 need_ipv4_conntrack();
726 ret
= nf_ct_extend_register(&nat_extend
);
728 printk(KERN_ERR
"nf_nat_core: Unable to register extension\n");
732 ret
= register_pernet_subsys(&nf_nat_net_ops
);
736 /* Sew in builtin protocols. */
737 spin_lock_bh(&nf_nat_lock
);
738 for (i
= 0; i
< MAX_IP_NAT_PROTO
; i
++)
739 RCU_INIT_POINTER(nf_nat_protos
[i
], &nf_nat_unknown_protocol
);
740 RCU_INIT_POINTER(nf_nat_protos
[IPPROTO_TCP
], &nf_nat_protocol_tcp
);
741 RCU_INIT_POINTER(nf_nat_protos
[IPPROTO_UDP
], &nf_nat_protocol_udp
);
742 RCU_INIT_POINTER(nf_nat_protos
[IPPROTO_ICMP
], &nf_nat_protocol_icmp
);
743 spin_unlock_bh(&nf_nat_lock
);
745 /* Initialize fake conntrack so that NAT will skip it */
746 nf_ct_untracked_status_or(IPS_NAT_DONE_MASK
);
748 l3proto
= nf_ct_l3proto_find_get((u_int16_t
)AF_INET
);
750 BUG_ON(nf_nat_seq_adjust_hook
!= NULL
);
751 RCU_INIT_POINTER(nf_nat_seq_adjust_hook
, nf_nat_seq_adjust
);
752 BUG_ON(nfnetlink_parse_nat_setup_hook
!= NULL
);
753 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook
,
754 nfnetlink_parse_nat_setup
);
755 BUG_ON(nf_ct_nat_offset
!= NULL
);
756 RCU_INIT_POINTER(nf_ct_nat_offset
, nf_nat_get_offset
);
760 nf_ct_extend_unregister(&nat_extend
);
764 static void __exit
nf_nat_cleanup(void)
766 unregister_pernet_subsys(&nf_nat_net_ops
);
767 nf_ct_l3proto_put(l3proto
);
768 nf_ct_extend_unregister(&nat_extend
);
769 RCU_INIT_POINTER(nf_nat_seq_adjust_hook
, NULL
);
770 RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook
, NULL
);
771 RCU_INIT_POINTER(nf_ct_nat_offset
, NULL
);
775 MODULE_LICENSE("GPL");
776 MODULE_ALIAS("nf-nat-ipv4");
778 module_init(nf_nat_init
);
779 module_exit(nf_nat_cleanup
);