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.
9 #include <linux/types.h>
11 #include <linux/netfilter.h>
12 #include <linux/module.h>
13 #include <linux/skbuff.h>
14 #include <linux/icmp.h>
15 #include <linux/sysctl.h>
16 #include <net/route.h>
19 #include <linux/netfilter_ipv4.h>
20 #include <net/netfilter/nf_conntrack.h>
21 #include <net/netfilter/nf_conntrack_helper.h>
22 #include <net/netfilter/nf_conntrack_l4proto.h>
23 #include <net/netfilter/nf_conntrack_l3proto.h>
24 #include <net/netfilter/nf_conntrack_core.h>
25 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
30 #define DEBUGP(format, args...)
33 #if defined(CONFIG_BCM_NAT) || defined(CONFIG_BCM_NAT_MODULE) || defined(HNDCTF)
34 int ipv4_conntrack_fastnat
= 0;
35 EXPORT_SYMBOL_GPL(ipv4_conntrack_fastnat
);
38 static int ipv4_pkt_to_tuple(const struct sk_buff
*skb
, unsigned int nhoff
,
39 struct nf_conntrack_tuple
*tuple
)
41 __be32 _addrs
[2], *ap
;
42 ap
= skb_header_pointer(skb
, nhoff
+ offsetof(struct iphdr
, saddr
),
43 sizeof(u_int32_t
) * 2, _addrs
);
47 tuple
->src
.u3
.ip
= ap
[0];
48 tuple
->dst
.u3
.ip
= ap
[1];
53 static int ipv4_invert_tuple(struct nf_conntrack_tuple
*tuple
,
54 const struct nf_conntrack_tuple
*orig
)
56 tuple
->src
.u3
.ip
= orig
->dst
.u3
.ip
;
57 tuple
->dst
.u3
.ip
= orig
->src
.u3
.ip
;
62 static int ipv4_print_tuple(struct seq_file
*s
,
63 const struct nf_conntrack_tuple
*tuple
)
65 return seq_printf(s
, "src=%u.%u.%u.%u dst=%u.%u.%u.%u ",
66 NIPQUAD(tuple
->src
.u3
.ip
),
67 NIPQUAD(tuple
->dst
.u3
.ip
));
70 /* Returns new sk_buff, or NULL */
71 #if !defined(CONFIG_BCM_NAT) && !defined(CONFIG_BCM_NAT_MODULE)
74 int nf_ct_ipv4_gather_frags(struct sk_buff
*skb
, u_int32_t user
)
81 err
= ip_defrag(skb
, user
);
85 ip_send_check(ip_hdr(skb
));
91 ipv4_prepare(struct sk_buff
*skb
, unsigned int hooknum
, unsigned int *dataoff
,
95 if (ip_hdr(skb
)->frag_off
& htons(IP_OFFSET
)) {
96 if (net_ratelimit()) {
97 printk(KERN_ERR
"ipv4_prepare: Frag of proto %u (hook=%u)\n",
98 ip_hdr(skb
)->protocol
, hooknum
);
103 *dataoff
= skb_network_offset(skb
) + ip_hdrlen(skb
);
104 *protonum
= ip_hdr(skb
)->protocol
;
109 int nf_nat_module_is_loaded
= 0;
110 EXPORT_SYMBOL_GPL(nf_nat_module_is_loaded
);
112 static u_int32_t
ipv4_get_features(const struct nf_conntrack_tuple
*tuple
)
114 if (nf_nat_module_is_loaded
)
117 return NF_CT_F_BASIC
;
120 static unsigned int ipv4_confirm(unsigned int hooknum
,
122 const struct net_device
*in
,
123 const struct net_device
*out
,
124 int (*okfn
)(struct sk_buff
*))
126 /* We've seen it coming out the other side: confirm it */
127 return nf_conntrack_confirm(skb
);
130 static unsigned int ipv4_conntrack_help(unsigned int hooknum
,
132 const struct net_device
*in
,
133 const struct net_device
*out
,
134 int (*okfn
)(struct sk_buff
*))
137 enum ip_conntrack_info ctinfo
;
138 struct nf_conn_help
*help
;
139 struct nf_conntrack_helper
*helper
;
141 /* This is where we call the helper: as the packet goes out. */
142 ct
= nf_ct_get(skb
, &ctinfo
);
143 if (!ct
|| ctinfo
== IP_CT_RELATED
+ IP_CT_IS_REPLY
)
146 help
= nfct_help(ct
);
149 /* rcu_read_lock()ed by nf_hook_slow */
150 helper
= rcu_dereference(help
->helper
);
153 return helper
->help(skb
, skb_network_offset(skb
) + ip_hdrlen(skb
),
157 static unsigned int ipv4_conntrack_defrag(unsigned int hooknum
,
159 const struct net_device
*in
,
160 const struct net_device
*out
,
161 int (*okfn
)(struct sk_buff
*))
163 /* Previously seen (loopback)? Ignore. Do this before
168 /* Gather fragments. */
169 if (ip_hdr(skb
)->frag_off
& htons(IP_MF
| IP_OFFSET
)) {
170 if (nf_ct_ipv4_gather_frags(skb
,
171 hooknum
== NF_IP_PRE_ROUTING
?
172 IP_DEFRAG_CONNTRACK_IN
:
173 IP_DEFRAG_CONNTRACK_OUT
))
179 static unsigned int ipv4_conntrack_in(unsigned int hooknum
,
181 const struct net_device
*in
,
182 const struct net_device
*out
,
183 int (*okfn
)(struct sk_buff
*))
185 return nf_conntrack_in(PF_INET
, hooknum
, skb
);
188 static unsigned int ipv4_conntrack_local(unsigned int hooknum
,
190 const struct net_device
*in
,
191 const struct net_device
*out
,
192 int (*okfn
)(struct sk_buff
*))
194 /* root is playing with raw sockets. */
195 if (skb
->len
< sizeof(struct iphdr
) ||
196 ip_hdrlen(skb
) < sizeof(struct iphdr
)) {
198 printk("ipt_hook: happy cracking.\n");
201 return nf_conntrack_in(PF_INET
, hooknum
, skb
);
204 /* Connection tracking may drop packets, but never alters them, so
205 make it the first hook. */
206 static struct nf_hook_ops ipv4_conntrack_ops
[] = {
208 .hook
= ipv4_conntrack_defrag
,
209 .owner
= THIS_MODULE
,
211 .hooknum
= NF_IP_PRE_ROUTING
,
212 .priority
= NF_IP_PRI_CONNTRACK_DEFRAG
,
215 .hook
= ipv4_conntrack_in
,
216 .owner
= THIS_MODULE
,
218 .hooknum
= NF_IP_PRE_ROUTING
,
219 .priority
= NF_IP_PRI_CONNTRACK
,
222 .hook
= ipv4_conntrack_defrag
,
223 .owner
= THIS_MODULE
,
225 .hooknum
= NF_IP_LOCAL_OUT
,
226 .priority
= NF_IP_PRI_CONNTRACK_DEFRAG
,
229 .hook
= ipv4_conntrack_local
,
230 .owner
= THIS_MODULE
,
232 .hooknum
= NF_IP_LOCAL_OUT
,
233 .priority
= NF_IP_PRI_CONNTRACK
,
236 .hook
= ipv4_conntrack_help
,
237 .owner
= THIS_MODULE
,
239 .hooknum
= NF_IP_POST_ROUTING
,
240 .priority
= NF_IP_PRI_CONNTRACK_HELPER
,
243 .hook
= ipv4_conntrack_help
,
244 .owner
= THIS_MODULE
,
246 .hooknum
= NF_IP_LOCAL_IN
,
247 .priority
= NF_IP_PRI_CONNTRACK_HELPER
,
250 .hook
= ipv4_confirm
,
251 .owner
= THIS_MODULE
,
253 .hooknum
= NF_IP_POST_ROUTING
,
254 .priority
= NF_IP_PRI_CONNTRACK_CONFIRM
,
257 .hook
= ipv4_confirm
,
258 .owner
= THIS_MODULE
,
260 .hooknum
= NF_IP_LOCAL_IN
,
261 .priority
= NF_IP_PRI_CONNTRACK_CONFIRM
,
265 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
266 static int log_invalid_proto_min
= 0;
267 static int log_invalid_proto_max
= 255;
269 static ctl_table ip_ct_sysctl_table
[] = {
271 .ctl_name
= NET_IPV4_NF_CONNTRACK_MAX
,
272 .procname
= "ip_conntrack_max",
273 .data
= &nf_conntrack_max
,
274 .maxlen
= sizeof(int),
276 .proc_handler
= &proc_dointvec
,
279 .ctl_name
= NET_IPV4_NF_CONNTRACK_COUNT
,
280 .procname
= "ip_conntrack_count",
281 .data
= &nf_conntrack_count
,
282 .maxlen
= sizeof(int),
284 .proc_handler
= &proc_dointvec
,
287 .ctl_name
= NET_IPV4_NF_CONNTRACK_BUCKETS
,
288 .procname
= "ip_conntrack_buckets",
289 .data
= &nf_conntrack_htable_size
,
290 .maxlen
= sizeof(unsigned int),
292 .proc_handler
= &proc_dointvec
,
295 .ctl_name
= NET_IPV4_NF_CONNTRACK_CHECKSUM
,
296 .procname
= "ip_conntrack_checksum",
297 .data
= &nf_conntrack_checksum
,
298 .maxlen
= sizeof(int),
300 .proc_handler
= &proc_dointvec
,
303 .ctl_name
= NET_IPV4_NF_CONNTRACK_LOG_INVALID
,
304 .procname
= "ip_conntrack_log_invalid",
305 .data
= &nf_ct_log_invalid
,
306 .maxlen
= sizeof(unsigned int),
308 .proc_handler
= &proc_dointvec_minmax
,
309 .strategy
= &sysctl_intvec
,
310 .extra1
= &log_invalid_proto_min
,
311 .extra2
= &log_invalid_proto_max
,
313 #if defined(CONFIG_BCM_NAT) || defined(CONFIG_BCM_NAT_MODULE) || defined(HNDCTF)
315 .ctl_name
= NET_IPV4_CONNTRACK_FASTNAT
,
316 .procname
= "ip_conntrack_fastnat",
317 .data
= &ipv4_conntrack_fastnat
,
318 .maxlen
= sizeof(int),
320 .proc_handler
= &proc_dointvec
,
327 #endif /* CONFIG_SYSCTL && CONFIG_NF_CONNTRACK_PROC_COMPAT */
329 /* Fast function for those who don't want to parse /proc (and I don't
331 /* Reversing the socket's dst/src point of view gives us the reply
334 getorigdst(struct sock
*sk
, int optval
, void __user
*user
, int *len
)
336 struct inet_sock
*inet
= inet_sk(sk
);
337 struct nf_conntrack_tuple_hash
*h
;
338 struct nf_conntrack_tuple tuple
;
340 memset(&tuple
, 0, sizeof(tuple
));
341 tuple
.src
.u3
.ip
= inet
->rcv_saddr
;
342 tuple
.src
.u
.tcp
.port
= inet
->sport
;
343 tuple
.dst
.u3
.ip
= inet
->daddr
;
344 tuple
.dst
.u
.tcp
.port
= inet
->dport
;
345 tuple
.src
.l3num
= PF_INET
;
346 tuple
.dst
.protonum
= IPPROTO_TCP
;
348 /* We only do TCP at the moment: is there a better way? */
349 if (strcmp(sk
->sk_prot
->name
, "TCP")) {
350 DEBUGP("SO_ORIGINAL_DST: Not a TCP socket\n");
354 if ((unsigned int) *len
< sizeof(struct sockaddr_in
)) {
355 DEBUGP("SO_ORIGINAL_DST: len %u not %u\n",
356 *len
, sizeof(struct sockaddr_in
));
360 h
= nf_conntrack_find_get(&tuple
, NULL
);
362 struct sockaddr_in sin
;
363 struct nf_conn
*ct
= nf_ct_tuplehash_to_ctrack(h
);
365 sin
.sin_family
= AF_INET
;
366 sin
.sin_port
= ct
->tuplehash
[IP_CT_DIR_ORIGINAL
]
367 .tuple
.dst
.u
.tcp
.port
;
368 sin
.sin_addr
.s_addr
= ct
->tuplehash
[IP_CT_DIR_ORIGINAL
]
370 memset(sin
.sin_zero
, 0, sizeof(sin
.sin_zero
));
372 DEBUGP("SO_ORIGINAL_DST: %u.%u.%u.%u %u\n",
373 NIPQUAD(sin
.sin_addr
.s_addr
), ntohs(sin
.sin_port
));
375 if (copy_to_user(user
, &sin
, sizeof(sin
)) != 0)
380 DEBUGP("SO_ORIGINAL_DST: Can't find %u.%u.%u.%u/%u-%u.%u.%u.%u/%u.\n",
381 NIPQUAD(tuple
.src
.u3
.ip
), ntohs(tuple
.src
.u
.tcp
.port
),
382 NIPQUAD(tuple
.dst
.u3
.ip
), ntohs(tuple
.dst
.u
.tcp
.port
));
386 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
388 #include <linux/netfilter/nfnetlink.h>
389 #include <linux/netfilter/nfnetlink_conntrack.h>
391 static int ipv4_tuple_to_nfattr(struct sk_buff
*skb
,
392 const struct nf_conntrack_tuple
*tuple
)
394 NFA_PUT(skb
, CTA_IP_V4_SRC
, sizeof(u_int32_t
),
396 NFA_PUT(skb
, CTA_IP_V4_DST
, sizeof(u_int32_t
),
404 static const size_t cta_min_ip
[CTA_IP_MAX
] = {
405 [CTA_IP_V4_SRC
-1] = sizeof(u_int32_t
),
406 [CTA_IP_V4_DST
-1] = sizeof(u_int32_t
),
409 static int ipv4_nfattr_to_tuple(struct nfattr
*tb
[],
410 struct nf_conntrack_tuple
*t
)
412 if (!tb
[CTA_IP_V4_SRC
-1] || !tb
[CTA_IP_V4_DST
-1])
415 if (nfattr_bad_size(tb
, CTA_IP_MAX
, cta_min_ip
))
418 t
->src
.u3
.ip
= *(__be32
*)NFA_DATA(tb
[CTA_IP_V4_SRC
-1]);
419 t
->dst
.u3
.ip
= *(__be32
*)NFA_DATA(tb
[CTA_IP_V4_DST
-1]);
425 static struct nf_sockopt_ops so_getorigdst
= {
427 .get_optmin
= SO_ORIGINAL_DST
,
428 .get_optmax
= SO_ORIGINAL_DST
+1,
432 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4
= {
435 .pkt_to_tuple
= ipv4_pkt_to_tuple
,
436 .invert_tuple
= ipv4_invert_tuple
,
437 .print_tuple
= ipv4_print_tuple
,
438 .prepare
= ipv4_prepare
,
439 .get_features
= ipv4_get_features
,
440 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
441 .tuple_to_nfattr
= ipv4_tuple_to_nfattr
,
442 .nfattr_to_tuple
= ipv4_nfattr_to_tuple
,
444 #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
445 .ctl_table_path
= nf_net_ipv4_netfilter_sysctl_path
,
446 .ctl_table
= ip_ct_sysctl_table
,
451 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET
));
452 MODULE_ALIAS("ip_conntrack");
453 MODULE_LICENSE("GPL");
455 static int __init
nf_conntrack_l3proto_ipv4_init(void)
461 ret
= nf_register_sockopt(&so_getorigdst
);
463 printk(KERN_ERR
"Unable to register netfilter socket option\n");
467 ret
= nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp4
);
469 printk("nf_conntrack_ipv4: can't register tcp.\n");
470 goto cleanup_sockopt
;
473 ret
= nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp4
);
475 printk("nf_conntrack_ipv4: can't register udp.\n");
479 ret
= nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmp
);
481 printk("nf_conntrack_ipv4: can't register icmp.\n");
485 ret
= nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv4
);
487 printk("nf_conntrack_ipv4: can't register ipv4\n");
491 ret
= nf_register_hooks(ipv4_conntrack_ops
,
492 ARRAY_SIZE(ipv4_conntrack_ops
));
494 printk("nf_conntrack_ipv4: can't register hooks.\n");
497 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
498 ret
= nf_conntrack_ipv4_compat_init();
503 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
505 nf_unregister_hooks(ipv4_conntrack_ops
, ARRAY_SIZE(ipv4_conntrack_ops
));
508 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4
);
510 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp
);
512 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4
);
514 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4
);
516 nf_unregister_sockopt(&so_getorigdst
);
520 static void __exit
nf_conntrack_l3proto_ipv4_fini(void)
523 #if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
524 nf_conntrack_ipv4_compat_fini();
526 nf_unregister_hooks(ipv4_conntrack_ops
, ARRAY_SIZE(ipv4_conntrack_ops
));
527 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4
);
528 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp
);
529 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4
);
530 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4
);
531 nf_unregister_sockopt(&so_getorigdst
);
534 module_init(nf_conntrack_l3proto_ipv4_init
);
535 module_exit(nf_conntrack_l3proto_ipv4_fini
);