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>
35 #ifdef CONFIG_IP_NF_TARGET_CONE
36 #include <linux/netfilter_ipv4/ipt_cone.h>
37 #endif /* CONFIG_IP_NF_TARGET_CONE */
40 #include <linux/if_vlan.h>
43 #include <ctf/hndctf.h>
45 #define NFC_CTF_ENABLED (1 << 31)
48 static DEFINE_SPINLOCK(nf_nat_lock
);
50 static struct nf_conntrack_l3proto
*l3proto __read_mostly
;
52 #define MAX_IP_NAT_PROTO 256
53 static const struct nf_nat_protocol
*nf_nat_protos
[MAX_IP_NAT_PROTO
]
56 static inline const struct nf_nat_protocol
*
57 __nf_nat_proto_find(u_int8_t protonum
)
59 return rcu_dereference(nf_nat_protos
[protonum
]);
62 const struct nf_nat_protocol
*
63 nf_nat_proto_find_get(u_int8_t protonum
)
65 const struct nf_nat_protocol
*p
;
68 p
= __nf_nat_proto_find(protonum
);
69 if (!try_module_get(p
->me
))
70 p
= &nf_nat_unknown_protocol
;
75 EXPORT_SYMBOL_GPL(nf_nat_proto_find_get
);
78 nf_nat_proto_put(const struct nf_nat_protocol
*p
)
82 EXPORT_SYMBOL_GPL(nf_nat_proto_put
);
84 /* We keep an extra hash for each conntrack, for fast searching. */
85 static inline unsigned int
86 hash_by_src(const struct net
*net
, u16 zone
,
87 const struct nf_conntrack_tuple
*tuple
)
91 /* Original src, to ensure we map it consistently if poss. */
92 hash
= jhash_3words((__force u32
)tuple
->src
.u3
.ip
,
93 (__force u32
)tuple
->src
.u
.all
^ zone
,
94 tuple
->dst
.protonum
, 0);
95 return ((u64
)hash
* net
->ipv4
.nat_htable_size
) >> 32;
99 extern void ip_conntrack_ipct_add(struct sk_buff
*skb
, u_int32_t hooknum
,
100 struct nf_conn
*ct
, enum ip_conntrack_info ci
,
101 struct nf_conntrack_tuple
*manip
);
104 /* Is this tuple already taken? (not by us) */
106 nf_nat_used_tuple(const struct nf_conntrack_tuple
*tuple
,
107 const struct nf_conn
*ignored_conntrack
)
109 /* Conntrack tracking doesn't keep track of outgoing tuples; only
110 incoming ones. NAT means they don't have a fixed mapping,
111 so we invert the tuple and look for the incoming reply.
113 We could keep a separate hash if this proves too slow. */
114 struct nf_conntrack_tuple reply
;
116 nf_ct_invert_tuplepr(&reply
, tuple
);
117 return nf_conntrack_tuple_taken(&reply
, ignored_conntrack
);
119 EXPORT_SYMBOL(nf_nat_used_tuple
);
121 /* If we source map this tuple so reply looks like reply_tuple, will
122 * that meet the constraints of range. */
124 in_range(const struct nf_conntrack_tuple
*tuple
,
125 const struct nf_nat_range
*range
)
127 const struct nf_nat_protocol
*proto
;
130 /* If we are supposed to map IPs, then we must be in the
131 range specified, otherwise let this drag us onto a new src IP. */
132 if (range
->flags
& IP_NAT_RANGE_MAP_IPS
) {
133 if (ntohl(tuple
->src
.u3
.ip
) < ntohl(range
->min_ip
) ||
134 ntohl(tuple
->src
.u3
.ip
) > ntohl(range
->max_ip
))
139 proto
= __nf_nat_proto_find(tuple
->dst
.protonum
);
140 if (!(range
->flags
& IP_NAT_RANGE_PROTO_SPECIFIED
) ||
141 proto
->in_range(tuple
, IP_NAT_MANIP_SRC
,
142 &range
->min
, &range
->max
))
150 same_src(const struct nf_conn
*ct
,
151 const struct nf_conntrack_tuple
*tuple
)
153 const struct nf_conntrack_tuple
*t
;
155 t
= &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
;
156 return (t
->dst
.protonum
== tuple
->dst
.protonum
&&
157 t
->src
.u3
.ip
== tuple
->src
.u3
.ip
&&
158 t
->src
.u
.all
== tuple
->src
.u
.all
);
161 /* Only called for SRC manip */
163 find_appropriate_src(struct net
*net
, u16 zone
,
164 const struct nf_conntrack_tuple
*tuple
,
165 struct nf_conntrack_tuple
*result
,
166 const struct nf_nat_range
*range
)
168 unsigned int h
= hash_by_src(net
, zone
, tuple
);
169 const struct nf_conn_nat
*nat
;
170 const struct nf_conn
*ct
;
171 const struct hlist_node
*n
;
174 hlist_for_each_entry_rcu(nat
, n
, &net
->ipv4
.nat_bysource
[h
], bysource
) {
176 if (same_src(ct
, tuple
) && nf_ct_zone(ct
) == zone
) {
177 /* Copy source part from reply tuple. */
178 nf_ct_invert_tuplepr(result
,
179 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
180 result
->dst
= tuple
->dst
;
182 if (in_range(result
, range
)) {
192 /* For [FUTURE] fragmentation handling, we want the least-used
193 src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus
194 if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
195 1-65535, we don't do pro-rata allocation based on ports; we choose
196 the ip with the lowest src-ip/dst-ip/proto usage.
199 find_best_ips_proto(u16 zone
, struct nf_conntrack_tuple
*tuple
,
200 const struct nf_nat_range
*range
,
201 const struct nf_conn
*ct
,
202 enum nf_nat_manip_type maniptype
)
206 u_int32_t minip
, maxip
, j
;
208 /* No IP mapping? Do nothing. */
209 if (!(range
->flags
& IP_NAT_RANGE_MAP_IPS
))
212 if (maniptype
== IP_NAT_MANIP_SRC
)
213 var_ipp
= &tuple
->src
.u3
.ip
;
215 var_ipp
= &tuple
->dst
.u3
.ip
;
217 /* Fast path: only one choice. */
218 if (range
->min_ip
== range
->max_ip
) {
219 *var_ipp
= range
->min_ip
;
223 /* Hashing source and destination IPs gives a fairly even
224 * spread in practice (if there are a small number of IPs
225 * involved, there usually aren't that many connections
226 * anyway). The consistency means that servers see the same
227 * client coming from the same IP (some Internet Banking sites
228 * like this), even across reboots. */
229 minip
= ntohl(range
->min_ip
);
230 maxip
= ntohl(range
->max_ip
);
231 j
= jhash_2words((__force u32
)tuple
->src
.u3
.ip
,
232 range
->flags
& IP_NAT_RANGE_PERSISTENT
?
233 0 : (__force u32
)tuple
->dst
.u3
.ip
^ zone
, 0);
234 j
= ((u64
)j
* (maxip
- minip
+ 1)) >> 32;
235 *var_ipp
= htonl(minip
+ j
);
238 /* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
239 * we change the source to map into the range. For NF_INET_PRE_ROUTING
240 * and NF_INET_LOCAL_OUT, we change the destination to map into the
241 * range. It might not be possible to get a unique tuple, but we try.
242 * At worst (or if we race), we will end up with a final duplicate in
243 * __ip_conntrack_confirm and drop the packet. */
245 get_unique_tuple(struct nf_conntrack_tuple
*tuple
,
246 const struct nf_conntrack_tuple
*orig_tuple
,
247 const struct nf_nat_range
*range
,
249 enum nf_nat_manip_type maniptype
)
251 struct net
*net
= nf_ct_net(ct
);
252 const struct nf_nat_protocol
*proto
;
253 u16 zone
= nf_ct_zone(ct
);
255 /* 1) If this srcip/proto/src-proto-part is currently mapped,
256 and that same mapping gives a unique tuple within the given
259 This is only required for source (ie. NAT/masq) mappings.
260 So far, we don't do local source mappings, so multiple
261 manips not an issue. */
262 if (maniptype
== IP_NAT_MANIP_SRC
&&
263 !(range
->flags
& IP_NAT_RANGE_PROTO_RANDOM
)) {
264 if (find_appropriate_src(net
, zone
, orig_tuple
, tuple
, range
)) {
265 pr_debug("get_unique_tuple: Found current src map\n");
266 if (!nf_nat_used_tuple(tuple
, ct
))
271 /* 2) Select the least-used IP/proto combination in the given
273 *tuple
= *orig_tuple
;
274 find_best_ips_proto(zone
, tuple
, range
, ct
, maniptype
);
276 /* 3) The per-protocol part of the manip is made to map into
277 the range to make a unique tuple. */
280 proto
= __nf_nat_proto_find(orig_tuple
->dst
.protonum
);
282 /* Only bother mapping if it's not already in range and unique */
283 if (!(range
->flags
& IP_NAT_RANGE_PROTO_RANDOM
) &&
284 (!(range
->flags
& IP_NAT_RANGE_PROTO_SPECIFIED
) ||
285 proto
->in_range(tuple
, maniptype
, &range
->min
, &range
->max
)) &&
286 !nf_nat_used_tuple(tuple
, ct
))
289 /* Last change: get protocol to try to obtain unique tuple. */
290 proto
->unique_tuple(tuple
, range
, maniptype
, ct
);
296 nf_nat_setup_info(struct nf_conn
*ct
,
297 const struct nf_nat_range
*range
,
298 enum nf_nat_manip_type maniptype
)
300 struct net
*net
= nf_ct_net(ct
);
301 struct nf_conntrack_tuple curr_tuple
, new_tuple
;
302 struct nf_conn_nat
*nat
;
303 int have_to_hash
= !(ct
->status
& IPS_NAT_DONE_MASK
);
305 /* nat helper or nfctnetlink also setup binding */
308 nat
= nf_ct_ext_add(ct
, NF_CT_EXT_NAT
, GFP_ATOMIC
);
310 pr_debug("failed to add NAT extension\n");
315 NF_CT_ASSERT(maniptype
== IP_NAT_MANIP_SRC
||
316 maniptype
== IP_NAT_MANIP_DST
);
317 BUG_ON(nf_nat_initialized(ct
, maniptype
));
319 /* What we've got will look like inverse of reply. Normally
320 this is what is in the conntrack, except for prior
321 manipulations (future optimization: if num_manips == 0,
323 conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple) */
324 nf_ct_invert_tuplepr(&curr_tuple
,
325 &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
327 get_unique_tuple(&new_tuple
, &curr_tuple
, range
, ct
, maniptype
);
329 if (!nf_ct_tuple_equal(&new_tuple
, &curr_tuple
)) {
330 struct nf_conntrack_tuple reply
;
332 /* Alter conntrack table so will recognize replies. */
333 nf_ct_invert_tuplepr(&reply
, &new_tuple
);
334 nf_conntrack_alter_reply(ct
, &reply
);
336 /* Non-atomic: we own this at the moment. */
337 if (maniptype
== IP_NAT_MANIP_SRC
)
338 ct
->status
|= IPS_SRC_NAT
;
340 ct
->status
|= IPS_DST_NAT
;
343 /* Place in source hash if this is the first time. */
345 unsigned int srchash
;
347 srchash
= hash_by_src(net
, nf_ct_zone(ct
),
348 &ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
349 spin_lock_bh(&nf_nat_lock
);
350 /* nf_conntrack_alter_reply might re-allocate exntension aera */
353 hlist_add_head_rcu(&nat
->bysource
,
354 &net
->ipv4
.nat_bysource
[srchash
]);
355 spin_unlock_bh(&nf_nat_lock
);
359 if (maniptype
== IP_NAT_MANIP_DST
)
360 set_bit(IPS_DST_NAT_DONE_BIT
, &ct
->status
);
362 set_bit(IPS_SRC_NAT_DONE_BIT
, &ct
->status
);
366 EXPORT_SYMBOL(nf_nat_setup_info
);
368 /* Returns true if succeeded. */
370 manip_pkt(u_int16_t proto
,
372 unsigned int iphdroff
,
373 const struct nf_conntrack_tuple
*target
,
374 enum nf_nat_manip_type maniptype
)
377 const struct nf_nat_protocol
*p
;
379 if (!skb_make_writable(skb
, iphdroff
+ sizeof(*iph
)))
382 iph
= (void *)skb
->data
+ iphdroff
;
384 /* Manipulate protcol part. */
386 /* rcu_read_lock()ed by nf_hook_slow */
387 p
= __nf_nat_proto_find(proto
);
388 if (!p
->manip_pkt(skb
, iphdroff
, target
, maniptype
))
391 iph
= (void *)skb
->data
+ iphdroff
;
393 if (maniptype
== IP_NAT_MANIP_SRC
) {
394 csum_replace4(&iph
->check
, iph
->saddr
, target
->src
.u3
.ip
);
395 iph
->saddr
= target
->src
.u3
.ip
;
397 csum_replace4(&iph
->check
, iph
->daddr
, target
->dst
.u3
.ip
);
398 iph
->daddr
= target
->dst
.u3
.ip
;
403 /* Do packet manipulations according to nf_nat_setup_info. */
404 unsigned int nf_nat_packet(struct nf_conn
*ct
,
405 enum ip_conntrack_info ctinfo
,
406 unsigned int hooknum
,
409 enum ip_conntrack_dir dir
= CTINFO2DIR(ctinfo
);
410 unsigned long statusbit
;
411 enum nf_nat_manip_type mtype
= HOOK2MANIP(hooknum
);
413 if (mtype
== IP_NAT_MANIP_SRC
)
414 statusbit
= IPS_SRC_NAT
;
416 statusbit
= IPS_DST_NAT
;
418 /* Invert if this is reply dir. */
419 if (dir
== IP_CT_DIR_REPLY
)
420 statusbit
^= IPS_NAT_MASK
;
422 /* Non-atomic: these bits don't change. */
423 if (ct
->status
& statusbit
) {
424 struct nf_conntrack_tuple target
;
426 /* We are aiming to look like inverse of other direction. */
427 nf_ct_invert_tuplepr(&target
, &ct
->tuplehash
[!dir
].tuple
);
429 ip_conntrack_ipct_add(skb
, hooknum
, ct
, ctinfo
, &target
);
431 if (!manip_pkt(target
.dst
.protonum
, skb
, 0, &target
, mtype
))
440 EXPORT_SYMBOL_GPL(nf_nat_packet
);
442 /* Dir is direction ICMP is coming from (opposite to packet it contains) */
443 int nf_nat_icmp_reply_translation(struct nf_conn
*ct
,
444 enum ip_conntrack_info ctinfo
,
445 unsigned int hooknum
,
452 const struct nf_conntrack_l4proto
*l4proto
;
453 struct nf_conntrack_tuple inner
, target
;
454 int hdrlen
= ip_hdrlen(skb
);
455 enum ip_conntrack_dir dir
= CTINFO2DIR(ctinfo
);
456 unsigned long statusbit
;
457 enum nf_nat_manip_type manip
= HOOK2MANIP(hooknum
);
459 if (!skb_make_writable(skb
, hdrlen
+ sizeof(*inside
)))
462 inside
= (void *)skb
->data
+ hdrlen
;
464 /* We're actually going to mangle it beyond trivial checksum
465 adjustment, so make sure the current checksum is correct. */
466 if (nf_ip_checksum(skb
, hooknum
, hdrlen
, 0))
469 /* Must be RELATED */
470 NF_CT_ASSERT(skb
->nfctinfo
== IP_CT_RELATED
||
471 skb
->nfctinfo
== IP_CT_RELATED
+IP_CT_IS_REPLY
);
473 /* Redirects on non-null nats must be dropped, else they'll
474 start talking to each other without our translation, and be
476 if (inside
->icmp
.type
== ICMP_REDIRECT
) {
477 /* If NAT isn't finished, assume it and drop. */
478 if ((ct
->status
& IPS_NAT_DONE_MASK
) != IPS_NAT_DONE_MASK
)
481 if (ct
->status
& IPS_NAT_MASK
)
485 pr_debug("icmp_reply_translation: translating error %p manip %u "
486 "dir %s\n", skb
, manip
,
487 dir
== IP_CT_DIR_ORIGINAL
? "ORIG" : "REPLY");
489 /* rcu_read_lock()ed by nf_hook_slow */
490 l4proto
= __nf_ct_l4proto_find(PF_INET
, inside
->ip
.protocol
);
492 if (!nf_ct_get_tuple(skb
, hdrlen
+ sizeof(struct icmphdr
),
494 sizeof(struct icmphdr
) + inside
->ip
.ihl
* 4),
495 (u_int16_t
)AF_INET
, inside
->ip
.protocol
,
496 &inner
, l3proto
, l4proto
))
499 /* Change inner back to look like incoming packet. We do the
500 opposite manip on this hook to normal, because it might not
501 pass all hooks (locally-generated ICMP). Consider incoming
502 packet: PREROUTING (DST manip), routing produces ICMP, goes
503 through POSTROUTING (which must correct the DST manip). */
504 if (!manip_pkt(inside
->ip
.protocol
, skb
, hdrlen
+ sizeof(inside
->icmp
),
505 &ct
->tuplehash
[!dir
].tuple
, !manip
))
508 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
) {
509 /* Reloading "inside" here since manip_pkt inner. */
510 inside
= (void *)skb
->data
+ hdrlen
;
511 inside
->icmp
.checksum
= 0;
512 inside
->icmp
.checksum
=
513 csum_fold(skb_checksum(skb
, hdrlen
,
514 skb
->len
- hdrlen
, 0));
517 /* Change outer to look the reply to an incoming packet
518 * (proto 0 means don't invert per-proto part). */
519 if (manip
== IP_NAT_MANIP_SRC
)
520 statusbit
= IPS_SRC_NAT
;
522 statusbit
= IPS_DST_NAT
;
524 /* Invert if this is reply dir. */
525 if (dir
== IP_CT_DIR_REPLY
)
526 statusbit
^= IPS_NAT_MASK
;
528 if (ct
->status
& statusbit
) {
529 nf_ct_invert_tuplepr(&target
, &ct
->tuplehash
[!dir
].tuple
);
530 if (!manip_pkt(0, skb
, 0, &target
, manip
))
536 EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation
);
538 /* Protocol registration. */
539 int nf_nat_protocol_register(const struct nf_nat_protocol
*proto
)
543 spin_lock_bh(&nf_nat_lock
);
544 if (nf_nat_protos
[proto
->protonum
] != &nf_nat_unknown_protocol
) {
548 rcu_assign_pointer(nf_nat_protos
[proto
->protonum
], proto
);
550 spin_unlock_bh(&nf_nat_lock
);
553 EXPORT_SYMBOL(nf_nat_protocol_register
);
555 /* Noone stores the protocol anywhere; simply delete it. */
556 void nf_nat_protocol_unregister(const struct nf_nat_protocol
*proto
)
558 spin_lock_bh(&nf_nat_lock
);
559 rcu_assign_pointer(nf_nat_protos
[proto
->protonum
],
560 &nf_nat_unknown_protocol
);
561 spin_unlock_bh(&nf_nat_lock
);
564 EXPORT_SYMBOL(nf_nat_protocol_unregister
);
566 /* Noone using conntrack by the time this called. */
567 static void nf_nat_cleanup_conntrack(struct nf_conn
*ct
)
569 struct nf_conn_nat
*nat
= nf_ct_ext_find(ct
, NF_CT_EXT_NAT
);
571 if (nat
== NULL
|| nat
->ct
== NULL
)
574 NF_CT_ASSERT(nat
->ct
->status
& IPS_NAT_DONE_MASK
);
576 spin_lock_bh(&nf_nat_lock
);
577 hlist_del_rcu(&nat
->bysource
);
578 spin_unlock_bh(&nf_nat_lock
);
579 #ifdef CONFIG_IP_NF_TARGET_CONE
580 /* Detach from cone list */
581 ipt_cone_cleanup_conntrack(nat
);
582 #endif /* CONFIG_IP_NF_TARGET_CONE */
585 static void nf_nat_move_storage(void *new, void *old
)
587 struct nf_conn_nat
*new_nat
= new;
588 struct nf_conn_nat
*old_nat
= old
;
589 struct nf_conn
*ct
= old_nat
->ct
;
591 if (!ct
|| !(ct
->status
& IPS_NAT_DONE_MASK
))
594 spin_lock_bh(&nf_nat_lock
);
596 hlist_replace_rcu(&old_nat
->bysource
, &new_nat
->bysource
);
597 spin_unlock_bh(&nf_nat_lock
);
600 static struct nf_ct_ext_type nat_extend __read_mostly
= {
601 .len
= sizeof(struct nf_conn_nat
),
602 .align
= __alignof__(struct nf_conn_nat
),
603 .destroy
= nf_nat_cleanup_conntrack
,
604 .move
= nf_nat_move_storage
,
606 .flags
= NF_CT_EXT_F_PREALLOC
,
609 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
611 #include <linux/netfilter/nfnetlink.h>
612 #include <linux/netfilter/nfnetlink_conntrack.h>
614 static const struct nla_policy protonat_nla_policy
[CTA_PROTONAT_MAX
+1] = {
615 [CTA_PROTONAT_PORT_MIN
] = { .type
= NLA_U16
},
616 [CTA_PROTONAT_PORT_MAX
] = { .type
= NLA_U16
},
619 static int nfnetlink_parse_nat_proto(struct nlattr
*attr
,
620 const struct nf_conn
*ct
,
621 struct nf_nat_range
*range
)
623 struct nlattr
*tb
[CTA_PROTONAT_MAX
+1];
624 const struct nf_nat_protocol
*npt
;
627 err
= nla_parse_nested(tb
, CTA_PROTONAT_MAX
, attr
, protonat_nla_policy
);
631 npt
= nf_nat_proto_find_get(nf_ct_protonum(ct
));
632 if (npt
->nlattr_to_range
)
633 err
= npt
->nlattr_to_range(tb
, range
);
634 nf_nat_proto_put(npt
);
638 static const struct nla_policy nat_nla_policy
[CTA_NAT_MAX
+1] = {
639 [CTA_NAT_MINIP
] = { .type
= NLA_U32
},
640 [CTA_NAT_MAXIP
] = { .type
= NLA_U32
},
644 nfnetlink_parse_nat(const struct nlattr
*nat
,
645 const struct nf_conn
*ct
, struct nf_nat_range
*range
)
647 struct nlattr
*tb
[CTA_NAT_MAX
+1];
650 memset(range
, 0, sizeof(*range
));
652 err
= nla_parse_nested(tb
, CTA_NAT_MAX
, nat
, nat_nla_policy
);
656 if (tb
[CTA_NAT_MINIP
])
657 range
->min_ip
= nla_get_be32(tb
[CTA_NAT_MINIP
]);
659 if (!tb
[CTA_NAT_MAXIP
])
660 range
->max_ip
= range
->min_ip
;
662 range
->max_ip
= nla_get_be32(tb
[CTA_NAT_MAXIP
]);
665 range
->flags
|= IP_NAT_RANGE_MAP_IPS
;
667 if (!tb
[CTA_NAT_PROTO
])
670 err
= nfnetlink_parse_nat_proto(tb
[CTA_NAT_PROTO
], ct
, range
);
678 nfnetlink_parse_nat_setup(struct nf_conn
*ct
,
679 enum nf_nat_manip_type manip
,
680 const struct nlattr
*attr
)
682 struct nf_nat_range range
;
684 if (nfnetlink_parse_nat(attr
, ct
, &range
) < 0)
686 if (nf_nat_initialized(ct
, manip
))
689 return nf_nat_setup_info(ct
, &range
, manip
);
693 nfnetlink_parse_nat_setup(struct nf_conn
*ct
,
694 enum nf_nat_manip_type manip
,
695 const struct nlattr
*attr
)
701 static int __net_init
nf_nat_net_init(struct net
*net
)
703 /* Leave them the same for the moment. */
704 net
->ipv4
.nat_htable_size
= net
->ct
.htable_size
;
705 net
->ipv4
.nat_bysource
= nf_ct_alloc_hashtable(&net
->ipv4
.nat_htable_size
,
706 &net
->ipv4
.nat_vmalloced
, 0);
707 if (!net
->ipv4
.nat_bysource
)
712 /* Clear NAT section of all conntracks, in case we're loaded again. */
713 static int clean_nat(struct nf_conn
*i
, void *data
)
715 struct nf_conn_nat
*nat
= nfct_nat(i
);
719 memset(nat
, 0, sizeof(*nat
));
720 i
->status
&= ~(IPS_NAT_MASK
| IPS_NAT_DONE_MASK
| IPS_SEQ_ADJUST
);
724 static void __net_exit
nf_nat_net_exit(struct net
*net
)
726 nf_ct_iterate_cleanup(net
, &clean_nat
, NULL
);
728 nf_ct_free_hashtable(net
->ipv4
.nat_bysource
, net
->ipv4
.nat_vmalloced
,
729 net
->ipv4
.nat_htable_size
);
732 static struct pernet_operations nf_nat_net_ops
= {
733 .init
= nf_nat_net_init
,
734 .exit
= nf_nat_net_exit
,
737 static int __init
nf_nat_init(void)
742 need_ipv4_conntrack();
744 ret
= nf_ct_extend_register(&nat_extend
);
746 printk(KERN_ERR
"nf_nat_core: Unable to register extension\n");
750 ret
= register_pernet_subsys(&nf_nat_net_ops
);
754 /* Sew in builtin protocols. */
755 spin_lock_bh(&nf_nat_lock
);
756 for (i
= 0; i
< MAX_IP_NAT_PROTO
; i
++)
757 rcu_assign_pointer(nf_nat_protos
[i
], &nf_nat_unknown_protocol
);
758 rcu_assign_pointer(nf_nat_protos
[IPPROTO_TCP
], &nf_nat_protocol_tcp
);
759 rcu_assign_pointer(nf_nat_protos
[IPPROTO_UDP
], &nf_nat_protocol_udp
);
760 rcu_assign_pointer(nf_nat_protos
[IPPROTO_ICMP
], &nf_nat_protocol_icmp
);
761 spin_unlock_bh(&nf_nat_lock
);
763 /* Initialize fake conntrack so that NAT will skip it */
764 nf_ct_untracked_status_or(IPS_NAT_DONE_MASK
);
766 l3proto
= nf_ct_l3proto_find_get((u_int16_t
)AF_INET
);
768 BUG_ON(nf_nat_seq_adjust_hook
!= NULL
);
769 rcu_assign_pointer(nf_nat_seq_adjust_hook
, nf_nat_seq_adjust
);
770 BUG_ON(nfnetlink_parse_nat_setup_hook
!= NULL
);
771 rcu_assign_pointer(nfnetlink_parse_nat_setup_hook
,
772 nfnetlink_parse_nat_setup
);
773 BUG_ON(nf_ct_nat_offset
!= NULL
);
774 rcu_assign_pointer(nf_ct_nat_offset
, nf_nat_get_offset
);
778 nf_ct_extend_unregister(&nat_extend
);
782 static void __exit
nf_nat_cleanup(void)
784 unregister_pernet_subsys(&nf_nat_net_ops
);
785 nf_ct_l3proto_put(l3proto
);
786 nf_ct_extend_unregister(&nat_extend
);
787 rcu_assign_pointer(nf_nat_seq_adjust_hook
, NULL
);
788 rcu_assign_pointer(nfnetlink_parse_nat_setup_hook
, NULL
);
789 rcu_assign_pointer(nf_ct_nat_offset
, NULL
);
793 MODULE_LICENSE("GPL");
794 MODULE_ALIAS("nf-nat-ipv4");
796 module_init(nf_nat_init
);
797 module_exit(nf_nat_cleanup
);