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/types.h>
19 #include <linux/netfilter.h>
20 #include <linux/module.h>
21 #include <linux/skbuff.h>
22 #include <linux/icmp.h>
23 #include <linux/sysctl.h>
24 #include <net/route.h>
27 #include <linux/netfilter_ipv4.h>
28 #include <net/netfilter/nf_conntrack.h>
29 #include <net/netfilter/nf_conntrack_helper.h>
30 #include <net/netfilter/nf_conntrack_l4proto.h>
31 #include <net/netfilter/nf_conntrack_l3proto.h>
32 #include <net/netfilter/nf_conntrack_core.h>
33 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
38 #define DEBUGP(format, args...)
41 static int ipv4_pkt_to_tuple(const struct sk_buff
*skb
, unsigned int nhoff
,
42 struct nf_conntrack_tuple
*tuple
)
44 __be32 _addrs
[2], *ap
;
45 ap
= skb_header_pointer(skb
, nhoff
+ offsetof(struct iphdr
, saddr
),
46 sizeof(u_int32_t
) * 2, _addrs
);
50 tuple
->src
.u3
.ip
= ap
[0];
51 tuple
->dst
.u3
.ip
= ap
[1];
56 static int ipv4_invert_tuple(struct nf_conntrack_tuple
*tuple
,
57 const struct nf_conntrack_tuple
*orig
)
59 tuple
->src
.u3
.ip
= orig
->dst
.u3
.ip
;
60 tuple
->dst
.u3
.ip
= orig
->src
.u3
.ip
;
65 static int ipv4_print_tuple(struct seq_file
*s
,
66 const struct nf_conntrack_tuple
*tuple
)
68 return seq_printf(s
, "src=%u.%u.%u.%u dst=%u.%u.%u.%u ",
69 NIPQUAD(tuple
->src
.u3
.ip
),
70 NIPQUAD(tuple
->dst
.u3
.ip
));
73 static int ipv4_print_conntrack(struct seq_file
*s
,
74 const struct nf_conn
*conntrack
)
79 /* Returns new sk_buff, or NULL */
80 static struct sk_buff
*
81 nf_ct_ipv4_gather_frags(struct sk_buff
*skb
, u_int32_t user
)
86 skb
= ip_defrag(skb
, user
);
90 ip_send_check(skb
->nh
.iph
);
96 ipv4_prepare(struct sk_buff
**pskb
, unsigned int hooknum
, unsigned int *dataoff
,
100 if ((*pskb
)->nh
.iph
->frag_off
& htons(IP_OFFSET
)) {
101 if (net_ratelimit()) {
102 printk(KERN_ERR
"ipv4_prepare: Frag of proto %u (hook=%u)\n",
103 (*pskb
)->nh
.iph
->protocol
, hooknum
);
108 *dataoff
= skb_network_offset(*pskb
) + ip_hdrlen(*pskb
);
109 *protonum
= (*pskb
)->nh
.iph
->protocol
;
114 int nf_nat_module_is_loaded
= 0;
115 EXPORT_SYMBOL_GPL(nf_nat_module_is_loaded
);
117 static u_int32_t
ipv4_get_features(const struct nf_conntrack_tuple
*tuple
)
119 if (nf_nat_module_is_loaded
)
122 return NF_CT_F_BASIC
;
125 static unsigned int ipv4_confirm(unsigned int hooknum
,
126 struct sk_buff
**pskb
,
127 const struct net_device
*in
,
128 const struct net_device
*out
,
129 int (*okfn
)(struct sk_buff
*))
131 /* We've seen it coming out the other side: confirm it */
132 return nf_conntrack_confirm(pskb
);
135 static unsigned int ipv4_conntrack_help(unsigned int hooknum
,
136 struct sk_buff
**pskb
,
137 const struct net_device
*in
,
138 const struct net_device
*out
,
139 int (*okfn
)(struct sk_buff
*))
142 enum ip_conntrack_info ctinfo
;
143 struct nf_conn_help
*help
;
145 /* This is where we call the helper: as the packet goes out. */
146 ct
= nf_ct_get(*pskb
, &ctinfo
);
147 if (!ct
|| ctinfo
== IP_CT_RELATED
+ IP_CT_IS_REPLY
)
150 help
= nfct_help(ct
);
151 if (!help
|| !help
->helper
)
154 return help
->helper
->help(pskb
,
155 skb_network_offset(*pskb
) + ip_hdrlen(*pskb
),
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 || ip_hdrlen(*pskb
) < 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_ops
[] = {
213 .hook
= ipv4_conntrack_defrag
,
214 .owner
= THIS_MODULE
,
216 .hooknum
= NF_IP_PRE_ROUTING
,
217 .priority
= NF_IP_PRI_CONNTRACK_DEFRAG
,
220 .hook
= ipv4_conntrack_in
,
221 .owner
= THIS_MODULE
,
223 .hooknum
= NF_IP_PRE_ROUTING
,
224 .priority
= NF_IP_PRI_CONNTRACK
,
227 .hook
= ipv4_conntrack_defrag
,
228 .owner
= THIS_MODULE
,
230 .hooknum
= NF_IP_LOCAL_OUT
,
231 .priority
= NF_IP_PRI_CONNTRACK_DEFRAG
,
234 .hook
= ipv4_conntrack_local
,
235 .owner
= THIS_MODULE
,
237 .hooknum
= NF_IP_LOCAL_OUT
,
238 .priority
= NF_IP_PRI_CONNTRACK
,
241 .hook
= ipv4_conntrack_help
,
242 .owner
= THIS_MODULE
,
244 .hooknum
= NF_IP_POST_ROUTING
,
245 .priority
= NF_IP_PRI_CONNTRACK_HELPER
,
248 .hook
= ipv4_conntrack_help
,
249 .owner
= THIS_MODULE
,
251 .hooknum
= NF_IP_LOCAL_IN
,
252 .priority
= NF_IP_PRI_CONNTRACK_HELPER
,
255 .hook
= ipv4_confirm
,
256 .owner
= THIS_MODULE
,
258 .hooknum
= NF_IP_POST_ROUTING
,
259 .priority
= NF_IP_PRI_CONNTRACK_CONFIRM
,
262 .hook
= ipv4_confirm
,
263 .owner
= THIS_MODULE
,
265 .hooknum
= NF_IP_LOCAL_IN
,
266 .priority
= NF_IP_PRI_CONNTRACK_CONFIRM
,
270 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
271 static int log_invalid_proto_min
= 0;
272 static int log_invalid_proto_max
= 255;
274 static ctl_table ip_ct_sysctl_table
[] = {
276 .ctl_name
= NET_IPV4_NF_CONNTRACK_MAX
,
277 .procname
= "ip_conntrack_max",
278 .data
= &nf_conntrack_max
,
279 .maxlen
= sizeof(int),
281 .proc_handler
= &proc_dointvec
,
284 .ctl_name
= NET_IPV4_NF_CONNTRACK_COUNT
,
285 .procname
= "ip_conntrack_count",
286 .data
= &nf_conntrack_count
,
287 .maxlen
= sizeof(int),
289 .proc_handler
= &proc_dointvec
,
292 .ctl_name
= NET_IPV4_NF_CONNTRACK_BUCKETS
,
293 .procname
= "ip_conntrack_buckets",
294 .data
= &nf_conntrack_htable_size
,
295 .maxlen
= sizeof(unsigned int),
297 .proc_handler
= &proc_dointvec
,
300 .ctl_name
= NET_IPV4_NF_CONNTRACK_CHECKSUM
,
301 .procname
= "ip_conntrack_checksum",
302 .data
= &nf_conntrack_checksum
,
303 .maxlen
= sizeof(int),
305 .proc_handler
= &proc_dointvec
,
308 .ctl_name
= NET_IPV4_NF_CONNTRACK_LOG_INVALID
,
309 .procname
= "ip_conntrack_log_invalid",
310 .data
= &nf_ct_log_invalid
,
311 .maxlen
= sizeof(unsigned int),
313 .proc_handler
= &proc_dointvec_minmax
,
314 .strategy
= &sysctl_intvec
,
315 .extra1
= &log_invalid_proto_min
,
316 .extra2
= &log_invalid_proto_max
,
322 #endif /* CONFIG_SYSCTL && CONFIG_NF_CONNTRACK_PROC_COMPAT */
324 /* Fast function for those who don't want to parse /proc (and I don't
326 /* Reversing the socket's dst/src point of view gives us the reply
329 getorigdst(struct sock
*sk
, int optval
, void __user
*user
, int *len
)
331 struct inet_sock
*inet
= inet_sk(sk
);
332 struct nf_conntrack_tuple_hash
*h
;
333 struct nf_conntrack_tuple tuple
;
335 NF_CT_TUPLE_U_BLANK(&tuple
);
336 tuple
.src
.u3
.ip
= inet
->rcv_saddr
;
337 tuple
.src
.u
.tcp
.port
= inet
->sport
;
338 tuple
.dst
.u3
.ip
= inet
->daddr
;
339 tuple
.dst
.u
.tcp
.port
= inet
->dport
;
340 tuple
.src
.l3num
= PF_INET
;
341 tuple
.dst
.protonum
= IPPROTO_TCP
;
343 /* We only do TCP at the moment: is there a better way? */
344 if (strcmp(sk
->sk_prot
->name
, "TCP")) {
345 DEBUGP("SO_ORIGINAL_DST: Not a TCP socket\n");
349 if ((unsigned int) *len
< sizeof(struct sockaddr_in
)) {
350 DEBUGP("SO_ORIGINAL_DST: len %u not %u\n",
351 *len
, sizeof(struct sockaddr_in
));
355 h
= nf_conntrack_find_get(&tuple
, NULL
);
357 struct sockaddr_in sin
;
358 struct nf_conn
*ct
= nf_ct_tuplehash_to_ctrack(h
);
360 sin
.sin_family
= AF_INET
;
361 sin
.sin_port
= ct
->tuplehash
[IP_CT_DIR_ORIGINAL
]
362 .tuple
.dst
.u
.tcp
.port
;
363 sin
.sin_addr
.s_addr
= ct
->tuplehash
[IP_CT_DIR_ORIGINAL
]
365 memset(sin
.sin_zero
, 0, sizeof(sin
.sin_zero
));
367 DEBUGP("SO_ORIGINAL_DST: %u.%u.%u.%u %u\n",
368 NIPQUAD(sin
.sin_addr
.s_addr
), ntohs(sin
.sin_port
));
370 if (copy_to_user(user
, &sin
, sizeof(sin
)) != 0)
375 DEBUGP("SO_ORIGINAL_DST: Can't find %u.%u.%u.%u/%u-%u.%u.%u.%u/%u.\n",
376 NIPQUAD(tuple
.src
.u3
.ip
), ntohs(tuple
.src
.u
.tcp
.port
),
377 NIPQUAD(tuple
.dst
.u3
.ip
), ntohs(tuple
.dst
.u
.tcp
.port
));
381 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
383 #include <linux/netfilter/nfnetlink.h>
384 #include <linux/netfilter/nfnetlink_conntrack.h>
386 static int ipv4_tuple_to_nfattr(struct sk_buff
*skb
,
387 const struct nf_conntrack_tuple
*tuple
)
389 NFA_PUT(skb
, CTA_IP_V4_SRC
, sizeof(u_int32_t
),
391 NFA_PUT(skb
, CTA_IP_V4_DST
, sizeof(u_int32_t
),
399 static const size_t cta_min_ip
[CTA_IP_MAX
] = {
400 [CTA_IP_V4_SRC
-1] = sizeof(u_int32_t
),
401 [CTA_IP_V4_DST
-1] = sizeof(u_int32_t
),
404 static int ipv4_nfattr_to_tuple(struct nfattr
*tb
[],
405 struct nf_conntrack_tuple
*t
)
407 if (!tb
[CTA_IP_V4_SRC
-1] || !tb
[CTA_IP_V4_DST
-1])
410 if (nfattr_bad_size(tb
, CTA_IP_MAX
, cta_min_ip
))
413 t
->src
.u3
.ip
= *(__be32
*)NFA_DATA(tb
[CTA_IP_V4_SRC
-1]);
414 t
->dst
.u3
.ip
= *(__be32
*)NFA_DATA(tb
[CTA_IP_V4_DST
-1]);
420 static struct nf_sockopt_ops so_getorigdst
= {
422 .get_optmin
= SO_ORIGINAL_DST
,
423 .get_optmax
= SO_ORIGINAL_DST
+1,
427 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4
= {
430 .pkt_to_tuple
= ipv4_pkt_to_tuple
,
431 .invert_tuple
= ipv4_invert_tuple
,
432 .print_tuple
= ipv4_print_tuple
,
433 .print_conntrack
= ipv4_print_conntrack
,
434 .prepare
= ipv4_prepare
,
435 .get_features
= ipv4_get_features
,
436 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
437 .tuple_to_nfattr
= ipv4_tuple_to_nfattr
,
438 .nfattr_to_tuple
= ipv4_nfattr_to_tuple
,
440 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
441 .ctl_table_path
= nf_net_ipv4_netfilter_sysctl_path
,
442 .ctl_table
= ip_ct_sysctl_table
,
447 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET
));
448 MODULE_ALIAS("ip_conntrack");
449 MODULE_LICENSE("GPL");
451 static int __init
nf_conntrack_l3proto_ipv4_init(void)
457 ret
= nf_register_sockopt(&so_getorigdst
);
459 printk(KERN_ERR
"Unable to register netfilter socket option\n");
463 ret
= nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp4
);
465 printk("nf_conntrack_ipv4: can't register tcp.\n");
466 goto cleanup_sockopt
;
469 ret
= nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp4
);
471 printk("nf_conntrack_ipv4: can't register udp.\n");
475 ret
= nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmp
);
477 printk("nf_conntrack_ipv4: can't register icmp.\n");
481 ret
= nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv4
);
483 printk("nf_conntrack_ipv4: can't register ipv4\n");
487 ret
= nf_register_hooks(ipv4_conntrack_ops
,
488 ARRAY_SIZE(ipv4_conntrack_ops
));
490 printk("nf_conntrack_ipv4: can't register hooks.\n");
493 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
494 ret
= nf_conntrack_ipv4_compat_init();
499 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
501 nf_unregister_hooks(ipv4_conntrack_ops
, ARRAY_SIZE(ipv4_conntrack_ops
));
504 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4
);
506 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp
);
508 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4
);
510 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4
);
512 nf_unregister_sockopt(&so_getorigdst
);
516 static void __exit
nf_conntrack_l3proto_ipv4_fini(void)
519 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
520 nf_conntrack_ipv4_compat_fini();
522 nf_unregister_hooks(ipv4_conntrack_ops
, ARRAY_SIZE(ipv4_conntrack_ops
));
523 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4
);
524 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp
);
525 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4
);
526 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4
);
527 nf_unregister_sockopt(&so_getorigdst
);
530 module_init(nf_conntrack_l3proto_ipv4_init
);
531 module_exit(nf_conntrack_l3proto_ipv4_fini
);