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
;
144 struct nf_conn_help
*help
;
146 /* This is where we call the helper: as the packet goes out. */
147 ct
= nf_ct_get(*pskb
, &ctinfo
);
151 help
= nfct_help(ct
);
152 if (!help
|| !help
->helper
)
155 return help
->helper
->help(pskb
,
156 (*pskb
)->nh
.raw
- (*pskb
)->data
157 + (*pskb
)->nh
.iph
->ihl
*4,
161 static unsigned int ipv4_conntrack_defrag(unsigned int hooknum
,
162 struct sk_buff
**pskb
,
163 const struct net_device
*in
,
164 const struct net_device
*out
,
165 int (*okfn
)(struct sk_buff
*))
167 #if !defined(CONFIG_IP_NF_NAT) && !defined(CONFIG_IP_NF_NAT_MODULE)
168 /* Previously seen (loopback)? Ignore. Do this before
174 /* Gather fragments. */
175 if ((*pskb
)->nh
.iph
->frag_off
& htons(IP_MF
|IP_OFFSET
)) {
176 *pskb
= nf_ct_ipv4_gather_frags(*pskb
,
177 hooknum
== NF_IP_PRE_ROUTING
?
178 IP_DEFRAG_CONNTRACK_IN
:
179 IP_DEFRAG_CONNTRACK_OUT
);
186 static unsigned int ipv4_conntrack_in(unsigned int hooknum
,
187 struct sk_buff
**pskb
,
188 const struct net_device
*in
,
189 const struct net_device
*out
,
190 int (*okfn
)(struct sk_buff
*))
192 return nf_conntrack_in(PF_INET
, hooknum
, pskb
);
195 static unsigned int ipv4_conntrack_local(unsigned int hooknum
,
196 struct sk_buff
**pskb
,
197 const struct net_device
*in
,
198 const struct net_device
*out
,
199 int (*okfn
)(struct sk_buff
*))
201 /* root is playing with raw sockets. */
202 if ((*pskb
)->len
< sizeof(struct iphdr
)
203 || (*pskb
)->nh
.iph
->ihl
* 4 < sizeof(struct iphdr
)) {
205 printk("ipt_hook: happy cracking.\n");
208 return nf_conntrack_in(PF_INET
, hooknum
, pskb
);
211 /* Connection tracking may drop packets, but never alters them, so
212 make it the first hook. */
213 static struct nf_hook_ops ipv4_conntrack_defrag_ops
= {
214 .hook
= ipv4_conntrack_defrag
,
215 .owner
= THIS_MODULE
,
217 .hooknum
= NF_IP_PRE_ROUTING
,
218 .priority
= NF_IP_PRI_CONNTRACK_DEFRAG
,
221 static struct nf_hook_ops ipv4_conntrack_in_ops
= {
222 .hook
= ipv4_conntrack_in
,
223 .owner
= THIS_MODULE
,
225 .hooknum
= NF_IP_PRE_ROUTING
,
226 .priority
= NF_IP_PRI_CONNTRACK
,
229 static struct nf_hook_ops ipv4_conntrack_defrag_local_out_ops
= {
230 .hook
= ipv4_conntrack_defrag
,
231 .owner
= THIS_MODULE
,
233 .hooknum
= NF_IP_LOCAL_OUT
,
234 .priority
= NF_IP_PRI_CONNTRACK_DEFRAG
,
237 static struct nf_hook_ops ipv4_conntrack_local_out_ops
= {
238 .hook
= ipv4_conntrack_local
,
239 .owner
= THIS_MODULE
,
241 .hooknum
= NF_IP_LOCAL_OUT
,
242 .priority
= NF_IP_PRI_CONNTRACK
,
246 static struct nf_hook_ops ipv4_conntrack_helper_out_ops
= {
247 .hook
= ipv4_conntrack_help
,
248 .owner
= THIS_MODULE
,
250 .hooknum
= NF_IP_POST_ROUTING
,
251 .priority
= NF_IP_PRI_CONNTRACK_HELPER
,
254 static struct nf_hook_ops ipv4_conntrack_helper_in_ops
= {
255 .hook
= ipv4_conntrack_help
,
256 .owner
= THIS_MODULE
,
258 .hooknum
= NF_IP_LOCAL_IN
,
259 .priority
= NF_IP_PRI_CONNTRACK_HELPER
,
263 /* Refragmenter; last chance. */
264 static struct nf_hook_ops ipv4_conntrack_out_ops
= {
265 .hook
= ipv4_confirm
,
266 .owner
= THIS_MODULE
,
268 .hooknum
= NF_IP_POST_ROUTING
,
269 .priority
= NF_IP_PRI_CONNTRACK_CONFIRM
,
272 static struct nf_hook_ops ipv4_conntrack_local_in_ops
= {
273 .hook
= ipv4_confirm
,
274 .owner
= THIS_MODULE
,
276 .hooknum
= NF_IP_LOCAL_IN
,
277 .priority
= NF_IP_PRI_CONNTRACK_CONFIRM
,
281 /* From nf_conntrack_proto_icmp.c */
282 extern unsigned int nf_ct_icmp_timeout
;
283 static struct ctl_table_header
*nf_ct_ipv4_sysctl_header
;
285 static ctl_table nf_ct_sysctl_table
[] = {
287 .ctl_name
= NET_NF_CONNTRACK_ICMP_TIMEOUT
,
288 .procname
= "nf_conntrack_icmp_timeout",
289 .data
= &nf_ct_icmp_timeout
,
290 .maxlen
= sizeof(unsigned int),
292 .proc_handler
= &proc_dointvec_jiffies
,
297 static ctl_table nf_ct_netfilter_table
[] = {
299 .ctl_name
= NET_NETFILTER
,
300 .procname
= "netfilter",
302 .child
= nf_ct_sysctl_table
,
307 static ctl_table nf_ct_net_table
[] = {
312 .child
= nf_ct_netfilter_table
,
318 /* Fast function for those who don't want to parse /proc (and I don't
320 /* Reversing the socket's dst/src point of view gives us the reply
323 getorigdst(struct sock
*sk
, int optval
, void __user
*user
, int *len
)
325 struct inet_sock
*inet
= inet_sk(sk
);
326 struct nf_conntrack_tuple_hash
*h
;
327 struct nf_conntrack_tuple tuple
;
329 NF_CT_TUPLE_U_BLANK(&tuple
);
330 tuple
.src
.u3
.ip
= inet
->rcv_saddr
;
331 tuple
.src
.u
.tcp
.port
= inet
->sport
;
332 tuple
.dst
.u3
.ip
= inet
->daddr
;
333 tuple
.dst
.u
.tcp
.port
= inet
->dport
;
334 tuple
.src
.l3num
= PF_INET
;
335 tuple
.dst
.protonum
= IPPROTO_TCP
;
337 /* We only do TCP at the moment: is there a better way? */
338 if (strcmp(sk
->sk_prot
->name
, "TCP")) {
339 DEBUGP("SO_ORIGINAL_DST: Not a TCP socket\n");
343 if ((unsigned int) *len
< sizeof(struct sockaddr_in
)) {
344 DEBUGP("SO_ORIGINAL_DST: len %u not %u\n",
345 *len
, sizeof(struct sockaddr_in
));
349 h
= nf_conntrack_find_get(&tuple
, NULL
);
351 struct sockaddr_in sin
;
352 struct nf_conn
*ct
= nf_ct_tuplehash_to_ctrack(h
);
354 sin
.sin_family
= AF_INET
;
355 sin
.sin_port
= ct
->tuplehash
[IP_CT_DIR_ORIGINAL
]
356 .tuple
.dst
.u
.tcp
.port
;
357 sin
.sin_addr
.s_addr
= ct
->tuplehash
[IP_CT_DIR_ORIGINAL
]
360 DEBUGP("SO_ORIGINAL_DST: %u.%u.%u.%u %u\n",
361 NIPQUAD(sin
.sin_addr
.s_addr
), ntohs(sin
.sin_port
));
363 if (copy_to_user(user
, &sin
, sizeof(sin
)) != 0)
368 DEBUGP("SO_ORIGINAL_DST: Can't find %u.%u.%u.%u/%u-%u.%u.%u.%u/%u.\n",
369 NIPQUAD(tuple
.src
.u3
.ip
), ntohs(tuple
.src
.u
.tcp
.port
),
370 NIPQUAD(tuple
.dst
.u3
.ip
), ntohs(tuple
.dst
.u
.tcp
.port
));
374 #if defined(CONFIG_NF_CT_NETLINK) || \
375 defined(CONFIG_NF_CT_NETLINK_MODULE)
377 #include <linux/netfilter/nfnetlink.h>
378 #include <linux/netfilter/nfnetlink_conntrack.h>
380 static int ipv4_tuple_to_nfattr(struct sk_buff
*skb
,
381 const struct nf_conntrack_tuple
*tuple
)
383 NFA_PUT(skb
, CTA_IP_V4_SRC
, sizeof(u_int32_t
),
385 NFA_PUT(skb
, CTA_IP_V4_DST
, sizeof(u_int32_t
),
393 static const size_t cta_min_ip
[CTA_IP_MAX
] = {
394 [CTA_IP_V4_SRC
-1] = sizeof(u_int32_t
),
395 [CTA_IP_V4_DST
-1] = sizeof(u_int32_t
),
398 static int ipv4_nfattr_to_tuple(struct nfattr
*tb
[],
399 struct nf_conntrack_tuple
*t
)
401 if (!tb
[CTA_IP_V4_SRC
-1] || !tb
[CTA_IP_V4_DST
-1])
404 if (nfattr_bad_size(tb
, CTA_IP_MAX
, cta_min_ip
))
408 *(u_int32_t
*)NFA_DATA(tb
[CTA_IP_V4_SRC
-1]);
410 *(u_int32_t
*)NFA_DATA(tb
[CTA_IP_V4_DST
-1]);
416 static struct nf_sockopt_ops so_getorigdst
= {
418 .get_optmin
= SO_ORIGINAL_DST
,
419 .get_optmax
= SO_ORIGINAL_DST
+1,
423 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4
= {
426 .pkt_to_tuple
= ipv4_pkt_to_tuple
,
427 .invert_tuple
= ipv4_invert_tuple
,
428 .print_tuple
= ipv4_print_tuple
,
429 .print_conntrack
= ipv4_print_conntrack
,
430 .prepare
= ipv4_prepare
,
431 .get_features
= ipv4_get_features
,
432 #if defined(CONFIG_NF_CT_NETLINK) || \
433 defined(CONFIG_NF_CT_NETLINK_MODULE)
434 .tuple_to_nfattr
= ipv4_tuple_to_nfattr
,
435 .nfattr_to_tuple
= ipv4_nfattr_to_tuple
,
440 extern struct nf_conntrack_protocol nf_conntrack_protocol_tcp4
;
441 extern struct nf_conntrack_protocol nf_conntrack_protocol_udp4
;
442 extern struct nf_conntrack_protocol nf_conntrack_protocol_icmp
;
443 static int init_or_cleanup(int init
)
447 if (!init
) goto cleanup
;
449 ret
= nf_register_sockopt(&so_getorigdst
);
451 printk(KERN_ERR
"Unable to register netfilter socket option\n");
452 goto cleanup_nothing
;
455 ret
= nf_conntrack_protocol_register(&nf_conntrack_protocol_tcp4
);
457 printk("nf_conntrack_ipv4: can't register tcp.\n");
458 goto cleanup_sockopt
;
461 ret
= nf_conntrack_protocol_register(&nf_conntrack_protocol_udp4
);
463 printk("nf_conntrack_ipv4: can't register udp.\n");
467 ret
= nf_conntrack_protocol_register(&nf_conntrack_protocol_icmp
);
469 printk("nf_conntrack_ipv4: can't register icmp.\n");
473 ret
= nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv4
);
475 printk("nf_conntrack_ipv4: can't register ipv4\n");
479 ret
= nf_register_hook(&ipv4_conntrack_defrag_ops
);
481 printk("nf_conntrack_ipv4: can't register pre-routing defrag hook.\n");
484 ret
= nf_register_hook(&ipv4_conntrack_defrag_local_out_ops
);
486 printk("nf_conntrack_ipv4: can't register local_out defrag hook.\n");
487 goto cleanup_defragops
;
490 ret
= nf_register_hook(&ipv4_conntrack_in_ops
);
492 printk("nf_conntrack_ipv4: can't register pre-routing hook.\n");
493 goto cleanup_defraglocalops
;
496 ret
= nf_register_hook(&ipv4_conntrack_local_out_ops
);
498 printk("nf_conntrack_ipv4: can't register local out hook.\n");
502 ret
= nf_register_hook(&ipv4_conntrack_helper_in_ops
);
504 printk("nf_conntrack_ipv4: can't register local helper hook.\n");
505 goto cleanup_inandlocalops
;
508 ret
= nf_register_hook(&ipv4_conntrack_helper_out_ops
);
510 printk("nf_conntrack_ipv4: can't register postrouting helper hook.\n");
511 goto cleanup_helperinops
;
514 ret
= nf_register_hook(&ipv4_conntrack_out_ops
);
516 printk("nf_conntrack_ipv4: can't register post-routing hook.\n");
517 goto cleanup_helperoutops
;
520 ret
= nf_register_hook(&ipv4_conntrack_local_in_ops
);
522 printk("nf_conntrack_ipv4: can't register local in hook.\n");
523 goto cleanup_inoutandlocalops
;
527 nf_ct_ipv4_sysctl_header
= register_sysctl_table(nf_ct_net_table
, 0);
528 if (nf_ct_ipv4_sysctl_header
== NULL
) {
529 printk("nf_conntrack: can't register to sysctl.\n");
531 goto cleanup_localinops
;
539 unregister_sysctl_table(nf_ct_ipv4_sysctl_header
);
542 nf_unregister_hook(&ipv4_conntrack_local_in_ops
);
543 cleanup_inoutandlocalops
:
544 nf_unregister_hook(&ipv4_conntrack_out_ops
);
545 cleanup_helperoutops
:
546 nf_unregister_hook(&ipv4_conntrack_helper_out_ops
);
548 nf_unregister_hook(&ipv4_conntrack_helper_in_ops
);
549 cleanup_inandlocalops
:
550 nf_unregister_hook(&ipv4_conntrack_local_out_ops
);
552 nf_unregister_hook(&ipv4_conntrack_in_ops
);
553 cleanup_defraglocalops
:
554 nf_unregister_hook(&ipv4_conntrack_defrag_local_out_ops
);
556 nf_unregister_hook(&ipv4_conntrack_defrag_ops
);
558 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4
);
560 nf_conntrack_protocol_unregister(&nf_conntrack_protocol_icmp
);
562 nf_conntrack_protocol_unregister(&nf_conntrack_protocol_udp4
);
564 nf_conntrack_protocol_unregister(&nf_conntrack_protocol_tcp4
);
566 nf_unregister_sockopt(&so_getorigdst
);
571 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET
));
572 MODULE_LICENSE("GPL");
574 static int __init
init(void)
577 return init_or_cleanup(1);
580 static void __exit
fini(void)
588 EXPORT_SYMBOL(nf_ct_ipv4_gather_frags
);