1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
9 * - move L3 protocol dependent part to this file.
10 * 23 Mar 2004: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
11 * - add get_features() to support various size of conntrack
14 * Derived from net/ipv4/netfilter/ip_conntrack_standalone.c
17 #include <linux/config.h>
18 #include <linux/types.h>
20 #include <linux/netfilter.h>
21 #include <linux/module.h>
22 #include <linux/skbuff.h>
23 #include <linux/icmp.h>
24 #include <linux/sysctl.h>
25 #include <net/route.h>
28 #include <linux/netfilter_ipv4.h>
29 #include <net/netfilter/nf_conntrack.h>
30 #include <net/netfilter/nf_conntrack_helper.h>
31 #include <net/netfilter/nf_conntrack_protocol.h>
32 #include <net/netfilter/nf_conntrack_l3proto.h>
33 #include <net/netfilter/nf_conntrack_core.h>
34 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
39 #define DEBUGP(format, args...)
42 DECLARE_PER_CPU(struct nf_conntrack_stat
, nf_conntrack_stat
);
44 static int ipv4_pkt_to_tuple(const struct sk_buff
*skb
, unsigned int nhoff
,
45 struct nf_conntrack_tuple
*tuple
)
47 u_int32_t _addrs
[2], *ap
;
48 ap
= skb_header_pointer(skb
, nhoff
+ offsetof(struct iphdr
, saddr
),
49 sizeof(u_int32_t
) * 2, _addrs
);
53 tuple
->src
.u3
.ip
= ap
[0];
54 tuple
->dst
.u3
.ip
= ap
[1];
59 static int ipv4_invert_tuple(struct nf_conntrack_tuple
*tuple
,
60 const struct nf_conntrack_tuple
*orig
)
62 tuple
->src
.u3
.ip
= orig
->dst
.u3
.ip
;
63 tuple
->dst
.u3
.ip
= orig
->src
.u3
.ip
;
68 static int ipv4_print_tuple(struct seq_file
*s
,
69 const struct nf_conntrack_tuple
*tuple
)
71 return seq_printf(s
, "src=%u.%u.%u.%u dst=%u.%u.%u.%u ",
72 NIPQUAD(tuple
->src
.u3
.ip
),
73 NIPQUAD(tuple
->dst
.u3
.ip
));
76 static int ipv4_print_conntrack(struct seq_file
*s
,
77 const struct nf_conn
*conntrack
)
82 /* Returns new sk_buff, or NULL */
83 static struct sk_buff
*
84 nf_ct_ipv4_gather_frags(struct sk_buff
*skb
, u_int32_t user
)
89 skb
= ip_defrag(skb
, user
);
93 ip_send_check(skb
->nh
.iph
);
99 ipv4_prepare(struct sk_buff
**pskb
, unsigned int hooknum
, unsigned int *dataoff
,
103 if ((*pskb
)->nh
.iph
->frag_off
& htons(IP_OFFSET
)) {
104 if (net_ratelimit()) {
105 printk(KERN_ERR
"ipv4_prepare: Frag of proto %u (hook=%u)\n",
106 (*pskb
)->nh
.iph
->protocol
, hooknum
);
111 *dataoff
= (*pskb
)->nh
.raw
- (*pskb
)->data
+ (*pskb
)->nh
.iph
->ihl
*4;
112 *protonum
= (*pskb
)->nh
.iph
->protocol
;
117 int nat_module_is_loaded
= 0;
118 static u_int32_t
ipv4_get_features(const struct nf_conntrack_tuple
*tuple
)
120 if (nat_module_is_loaded
)
123 return NF_CT_F_BASIC
;
126 static unsigned int ipv4_confirm(unsigned int hooknum
,
127 struct sk_buff
**pskb
,
128 const struct net_device
*in
,
129 const struct net_device
*out
,
130 int (*okfn
)(struct sk_buff
*))
132 /* We've seen it coming out the other side: confirm it */
133 return nf_conntrack_confirm(pskb
);
136 static unsigned int ipv4_conntrack_help(unsigned int hooknum
,
137 struct sk_buff
**pskb
,
138 const struct net_device
*in
,
139 const struct net_device
*out
,
140 int (*okfn
)(struct sk_buff
*))
143 enum ip_conntrack_info ctinfo
;
145 /* This is where we call the helper: as the packet goes out. */
146 ct
= nf_ct_get(*pskb
, &ctinfo
);
147 if (ct
&& ct
->helper
) {
149 ret
= ct
->helper
->help(pskb
,
150 (*pskb
)->nh
.raw
- (*pskb
)->data
151 + (*pskb
)->nh
.iph
->ihl
*4,
153 if (ret
!= NF_ACCEPT
)
159 static unsigned int ipv4_conntrack_defrag(unsigned int hooknum
,
160 struct sk_buff
**pskb
,
161 const struct net_device
*in
,
162 const struct net_device
*out
,
163 int (*okfn
)(struct sk_buff
*))
165 #if !defined(CONFIG_IP_NF_NAT) && !defined(CONFIG_IP_NF_NAT_MODULE)
166 /* Previously seen (loopback)? Ignore. Do this before
172 /* Gather fragments. */
173 if ((*pskb
)->nh
.iph
->frag_off
& htons(IP_MF
|IP_OFFSET
)) {
174 *pskb
= nf_ct_ipv4_gather_frags(*pskb
,
175 hooknum
== NF_IP_PRE_ROUTING
?
176 IP_DEFRAG_CONNTRACK_IN
:
177 IP_DEFRAG_CONNTRACK_OUT
);
184 static unsigned int ipv4_conntrack_in(unsigned int hooknum
,
185 struct sk_buff
**pskb
,
186 const struct net_device
*in
,
187 const struct net_device
*out
,
188 int (*okfn
)(struct sk_buff
*))
190 return nf_conntrack_in(PF_INET
, hooknum
, pskb
);
193 static unsigned int ipv4_conntrack_local(unsigned int hooknum
,
194 struct sk_buff
**pskb
,
195 const struct net_device
*in
,
196 const struct net_device
*out
,
197 int (*okfn
)(struct sk_buff
*))
199 /* root is playing with raw sockets. */
200 if ((*pskb
)->len
< sizeof(struct iphdr
)
201 || (*pskb
)->nh
.iph
->ihl
* 4 < sizeof(struct iphdr
)) {
203 printk("ipt_hook: happy cracking.\n");
206 return nf_conntrack_in(PF_INET
, hooknum
, pskb
);
209 /* Connection tracking may drop packets, but never alters them, so
210 make it the first hook. */
211 static struct nf_hook_ops ipv4_conntrack_defrag_ops
= {
212 .hook
= ipv4_conntrack_defrag
,
213 .owner
= THIS_MODULE
,
215 .hooknum
= NF_IP_PRE_ROUTING
,
216 .priority
= NF_IP_PRI_CONNTRACK_DEFRAG
,
219 static struct nf_hook_ops ipv4_conntrack_in_ops
= {
220 .hook
= ipv4_conntrack_in
,
221 .owner
= THIS_MODULE
,
223 .hooknum
= NF_IP_PRE_ROUTING
,
224 .priority
= NF_IP_PRI_CONNTRACK
,
227 static struct nf_hook_ops ipv4_conntrack_defrag_local_out_ops
= {
228 .hook
= ipv4_conntrack_defrag
,
229 .owner
= THIS_MODULE
,
231 .hooknum
= NF_IP_LOCAL_OUT
,
232 .priority
= NF_IP_PRI_CONNTRACK_DEFRAG
,
235 static struct nf_hook_ops ipv4_conntrack_local_out_ops
= {
236 .hook
= ipv4_conntrack_local
,
237 .owner
= THIS_MODULE
,
239 .hooknum
= NF_IP_LOCAL_OUT
,
240 .priority
= NF_IP_PRI_CONNTRACK
,
244 static struct nf_hook_ops ipv4_conntrack_helper_out_ops
= {
245 .hook
= ipv4_conntrack_help
,
246 .owner
= THIS_MODULE
,
248 .hooknum
= NF_IP_POST_ROUTING
,
249 .priority
= NF_IP_PRI_CONNTRACK_HELPER
,
252 static struct nf_hook_ops ipv4_conntrack_helper_in_ops
= {
253 .hook
= ipv4_conntrack_help
,
254 .owner
= THIS_MODULE
,
256 .hooknum
= NF_IP_LOCAL_IN
,
257 .priority
= NF_IP_PRI_CONNTRACK_HELPER
,
261 /* Refragmenter; last chance. */
262 static struct nf_hook_ops ipv4_conntrack_out_ops
= {
263 .hook
= ipv4_confirm
,
264 .owner
= THIS_MODULE
,
266 .hooknum
= NF_IP_POST_ROUTING
,
267 .priority
= NF_IP_PRI_CONNTRACK_CONFIRM
,
270 static struct nf_hook_ops ipv4_conntrack_local_in_ops
= {
271 .hook
= ipv4_confirm
,
272 .owner
= THIS_MODULE
,
274 .hooknum
= NF_IP_LOCAL_IN
,
275 .priority
= NF_IP_PRI_CONNTRACK_CONFIRM
,
279 /* From nf_conntrack_proto_icmp.c */
280 extern unsigned int nf_ct_icmp_timeout
;
281 static struct ctl_table_header
*nf_ct_ipv4_sysctl_header
;
283 static ctl_table nf_ct_sysctl_table
[] = {
285 .ctl_name
= NET_NF_CONNTRACK_ICMP_TIMEOUT
,
286 .procname
= "nf_conntrack_icmp_timeout",
287 .data
= &nf_ct_icmp_timeout
,
288 .maxlen
= sizeof(unsigned int),
290 .proc_handler
= &proc_dointvec_jiffies
,
295 static ctl_table nf_ct_netfilter_table
[] = {
297 .ctl_name
= NET_NETFILTER
,
298 .procname
= "netfilter",
300 .child
= nf_ct_sysctl_table
,
305 static ctl_table nf_ct_net_table
[] = {
310 .child
= nf_ct_netfilter_table
,
316 /* Fast function for those who don't want to parse /proc (and I don't
318 /* Reversing the socket's dst/src point of view gives us the reply
321 getorigdst(struct sock
*sk
, int optval
, void __user
*user
, int *len
)
323 struct inet_sock
*inet
= inet_sk(sk
);
324 struct nf_conntrack_tuple_hash
*h
;
325 struct nf_conntrack_tuple tuple
;
327 NF_CT_TUPLE_U_BLANK(&tuple
);
328 tuple
.src
.u3
.ip
= inet
->rcv_saddr
;
329 tuple
.src
.u
.tcp
.port
= inet
->sport
;
330 tuple
.dst
.u3
.ip
= inet
->daddr
;
331 tuple
.dst
.u
.tcp
.port
= inet
->dport
;
332 tuple
.src
.l3num
= PF_INET
;
333 tuple
.dst
.protonum
= IPPROTO_TCP
;
335 /* We only do TCP at the moment: is there a better way? */
336 if (strcmp(sk
->sk_prot
->name
, "TCP")) {
337 DEBUGP("SO_ORIGINAL_DST: Not a TCP socket\n");
341 if ((unsigned int) *len
< sizeof(struct sockaddr_in
)) {
342 DEBUGP("SO_ORIGINAL_DST: len %u not %u\n",
343 *len
, sizeof(struct sockaddr_in
));
347 h
= nf_conntrack_find_get(&tuple
, NULL
);
349 struct sockaddr_in sin
;
350 struct nf_conn
*ct
= nf_ct_tuplehash_to_ctrack(h
);
352 sin
.sin_family
= AF_INET
;
353 sin
.sin_port
= ct
->tuplehash
[IP_CT_DIR_ORIGINAL
]
354 .tuple
.dst
.u
.tcp
.port
;
355 sin
.sin_addr
.s_addr
= ct
->tuplehash
[IP_CT_DIR_ORIGINAL
]
358 DEBUGP("SO_ORIGINAL_DST: %u.%u.%u.%u %u\n",
359 NIPQUAD(sin
.sin_addr
.s_addr
), ntohs(sin
.sin_port
));
361 if (copy_to_user(user
, &sin
, sizeof(sin
)) != 0)
366 DEBUGP("SO_ORIGINAL_DST: Can't find %u.%u.%u.%u/%u-%u.%u.%u.%u/%u.\n",
367 NIPQUAD(tuple
.src
.u3
.ip
), ntohs(tuple
.src
.u
.tcp
.port
),
368 NIPQUAD(tuple
.dst
.u3
.ip
), ntohs(tuple
.dst
.u
.tcp
.port
));
372 #if defined(CONFIG_NF_CT_NETLINK) || \
373 defined(CONFIG_NF_CT_NETLINK_MODULE)
375 #include <linux/netfilter/nfnetlink.h>
376 #include <linux/netfilter/nfnetlink_conntrack.h>
378 static int ipv4_tuple_to_nfattr(struct sk_buff
*skb
,
379 const struct nf_conntrack_tuple
*tuple
)
381 NFA_PUT(skb
, CTA_IP_V4_SRC
, sizeof(u_int32_t
),
383 NFA_PUT(skb
, CTA_IP_V4_DST
, sizeof(u_int32_t
),
391 static const size_t cta_min_ip
[CTA_IP_MAX
] = {
392 [CTA_IP_V4_SRC
-1] = sizeof(u_int32_t
),
393 [CTA_IP_V4_DST
-1] = sizeof(u_int32_t
),
396 static int ipv4_nfattr_to_tuple(struct nfattr
*tb
[],
397 struct nf_conntrack_tuple
*t
)
399 if (!tb
[CTA_IP_V4_SRC
-1] || !tb
[CTA_IP_V4_DST
-1])
402 if (nfattr_bad_size(tb
, CTA_IP_MAX
, cta_min_ip
))
406 *(u_int32_t
*)NFA_DATA(tb
[CTA_IP_V4_SRC
-1]);
408 *(u_int32_t
*)NFA_DATA(tb
[CTA_IP_V4_DST
-1]);
414 static struct nf_sockopt_ops so_getorigdst
= {
416 .get_optmin
= SO_ORIGINAL_DST
,
417 .get_optmax
= SO_ORIGINAL_DST
+1,
421 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4
= {
424 .pkt_to_tuple
= ipv4_pkt_to_tuple
,
425 .invert_tuple
= ipv4_invert_tuple
,
426 .print_tuple
= ipv4_print_tuple
,
427 .print_conntrack
= ipv4_print_conntrack
,
428 .prepare
= ipv4_prepare
,
429 .get_features
= ipv4_get_features
,
430 #if defined(CONFIG_NF_CT_NETLINK) || \
431 defined(CONFIG_NF_CT_NETLINK_MODULE)
432 .tuple_to_nfattr
= ipv4_tuple_to_nfattr
,
433 .nfattr_to_tuple
= ipv4_nfattr_to_tuple
,
438 extern struct nf_conntrack_protocol nf_conntrack_protocol_tcp4
;
439 extern struct nf_conntrack_protocol nf_conntrack_protocol_udp4
;
440 extern struct nf_conntrack_protocol nf_conntrack_protocol_icmp
;
441 static int init_or_cleanup(int init
)
445 if (!init
) goto cleanup
;
447 ret
= nf_register_sockopt(&so_getorigdst
);
449 printk(KERN_ERR
"Unable to register netfilter socket option\n");
450 goto cleanup_nothing
;
453 ret
= nf_conntrack_protocol_register(&nf_conntrack_protocol_tcp4
);
455 printk("nf_conntrack_ipv4: can't register tcp.\n");
456 goto cleanup_sockopt
;
459 ret
= nf_conntrack_protocol_register(&nf_conntrack_protocol_udp4
);
461 printk("nf_conntrack_ipv4: can't register udp.\n");
465 ret
= nf_conntrack_protocol_register(&nf_conntrack_protocol_icmp
);
467 printk("nf_conntrack_ipv4: can't register icmp.\n");
471 ret
= nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv4
);
473 printk("nf_conntrack_ipv4: can't register ipv4\n");
477 ret
= nf_register_hook(&ipv4_conntrack_defrag_ops
);
479 printk("nf_conntrack_ipv4: can't register pre-routing defrag hook.\n");
482 ret
= nf_register_hook(&ipv4_conntrack_defrag_local_out_ops
);
484 printk("nf_conntrack_ipv4: can't register local_out defrag hook.\n");
485 goto cleanup_defragops
;
488 ret
= nf_register_hook(&ipv4_conntrack_in_ops
);
490 printk("nf_conntrack_ipv4: can't register pre-routing hook.\n");
491 goto cleanup_defraglocalops
;
494 ret
= nf_register_hook(&ipv4_conntrack_local_out_ops
);
496 printk("nf_conntrack_ipv4: can't register local out hook.\n");
500 ret
= nf_register_hook(&ipv4_conntrack_helper_in_ops
);
502 printk("nf_conntrack_ipv4: can't register local helper hook.\n");
503 goto cleanup_inandlocalops
;
506 ret
= nf_register_hook(&ipv4_conntrack_helper_out_ops
);
508 printk("nf_conntrack_ipv4: can't register postrouting helper hook.\n");
509 goto cleanup_helperinops
;
512 ret
= nf_register_hook(&ipv4_conntrack_out_ops
);
514 printk("nf_conntrack_ipv4: can't register post-routing hook.\n");
515 goto cleanup_helperoutops
;
518 ret
= nf_register_hook(&ipv4_conntrack_local_in_ops
);
520 printk("nf_conntrack_ipv4: can't register local in hook.\n");
521 goto cleanup_inoutandlocalops
;
525 nf_ct_ipv4_sysctl_header
= register_sysctl_table(nf_ct_net_table
, 0);
526 if (nf_ct_ipv4_sysctl_header
== NULL
) {
527 printk("nf_conntrack: can't register to sysctl.\n");
529 goto cleanup_localinops
;
537 unregister_sysctl_table(nf_ct_ipv4_sysctl_header
);
540 nf_unregister_hook(&ipv4_conntrack_local_in_ops
);
541 cleanup_inoutandlocalops
:
542 nf_unregister_hook(&ipv4_conntrack_out_ops
);
543 cleanup_helperoutops
:
544 nf_unregister_hook(&ipv4_conntrack_helper_out_ops
);
546 nf_unregister_hook(&ipv4_conntrack_helper_in_ops
);
547 cleanup_inandlocalops
:
548 nf_unregister_hook(&ipv4_conntrack_local_out_ops
);
550 nf_unregister_hook(&ipv4_conntrack_in_ops
);
551 cleanup_defraglocalops
:
552 nf_unregister_hook(&ipv4_conntrack_defrag_local_out_ops
);
554 nf_unregister_hook(&ipv4_conntrack_defrag_ops
);
556 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4
);
558 nf_conntrack_protocol_unregister(&nf_conntrack_protocol_icmp
);
560 nf_conntrack_protocol_unregister(&nf_conntrack_protocol_udp4
);
562 nf_conntrack_protocol_unregister(&nf_conntrack_protocol_tcp4
);
564 nf_unregister_sockopt(&so_getorigdst
);
569 MODULE_LICENSE("GPL");
571 static int __init
init(void)
574 return init_or_cleanup(1);
577 static void __exit
fini(void)
585 EXPORT_SYMBOL(nf_ct_ipv4_gather_frags
);