2 * Copyright (C)2004 USAGI/WIDE Project
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 * Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
12 #include <linux/types.h>
13 #include <linux/ipv6.h>
14 #include <linux/in6.h>
15 #include <linux/netfilter.h>
16 #include <linux/module.h>
17 #include <linux/skbuff.h>
18 #include <linux/icmp.h>
19 #include <linux/sysctl.h>
21 #include <net/inet_frag.h>
23 #include <linux/netfilter_ipv6.h>
24 #include <net/netfilter/nf_conntrack.h>
25 #include <net/netfilter/nf_conntrack_helper.h>
26 #include <net/netfilter/nf_conntrack_l4proto.h>
27 #include <net/netfilter/nf_conntrack_l3proto.h>
28 #include <net/netfilter/nf_conntrack_core.h>
30 static bool ipv6_pkt_to_tuple(const struct sk_buff
*skb
, unsigned int nhoff
,
31 struct nf_conntrack_tuple
*tuple
)
36 ap
= skb_header_pointer(skb
, nhoff
+ offsetof(struct ipv6hdr
, saddr
),
37 sizeof(_addrs
), _addrs
);
41 memcpy(tuple
->src
.u3
.ip6
, ap
, sizeof(tuple
->src
.u3
.ip6
));
42 memcpy(tuple
->dst
.u3
.ip6
, ap
+ 4, sizeof(tuple
->dst
.u3
.ip6
));
47 static bool ipv6_invert_tuple(struct nf_conntrack_tuple
*tuple
,
48 const struct nf_conntrack_tuple
*orig
)
50 memcpy(tuple
->src
.u3
.ip6
, orig
->dst
.u3
.ip6
, sizeof(tuple
->src
.u3
.ip6
));
51 memcpy(tuple
->dst
.u3
.ip6
, orig
->src
.u3
.ip6
, sizeof(tuple
->dst
.u3
.ip6
));
56 static int ipv6_print_tuple(struct seq_file
*s
,
57 const struct nf_conntrack_tuple
*tuple
)
59 return seq_printf(s
, "src=" NIP6_FMT
" dst=" NIP6_FMT
" ",
60 NIP6(*((struct in6_addr
*)tuple
->src
.u3
.ip6
)),
61 NIP6(*((struct in6_addr
*)tuple
->dst
.u3
.ip6
)));
65 * Based on ipv6_skip_exthdr() in net/ipv6/exthdr.c
67 * This function parses (probably truncated) exthdr set "hdr"
68 * of length "len". "nexthdrp" initially points to some place,
69 * where type of the first header can be found.
71 * It skips all well-known exthdrs, and returns pointer to the start
72 * of unparsable area i.e. the first header with unknown type.
73 * if success, *nexthdr is updated by type/protocol of this header.
75 * NOTES: - it may return pointer pointing beyond end of packet,
76 * if the last recognized header is truncated in the middle.
77 * - if packet is truncated, so that all parsed headers are skipped,
79 * - if packet is fragmented, return pointer of the fragment header.
80 * - ESP is unparsable for now and considered like
81 * normal payload protocol.
82 * - Note also special handling of AUTH header. Thanks to IPsec wizards.
85 static int nf_ct_ipv6_skip_exthdr(const struct sk_buff
*skb
, int start
,
86 u8
*nexthdrp
, int len
)
88 u8 nexthdr
= *nexthdrp
;
90 while (ipv6_ext_hdr(nexthdr
)) {
91 struct ipv6_opt_hdr hdr
;
94 if (len
< (int)sizeof(struct ipv6_opt_hdr
))
96 if (nexthdr
== NEXTHDR_NONE
)
98 if (nexthdr
== NEXTHDR_FRAGMENT
)
100 if (skb_copy_bits(skb
, start
, &hdr
, sizeof(hdr
)))
102 if (nexthdr
== NEXTHDR_AUTH
)
103 hdrlen
= (hdr
.hdrlen
+2)<<2;
105 hdrlen
= ipv6_optlen(&hdr
);
107 nexthdr
= hdr
.nexthdr
;
116 static int ipv6_get_l4proto(const struct sk_buff
*skb
, unsigned int nhoff
,
117 unsigned int *dataoff
, u_int8_t
*protonum
)
119 unsigned int extoff
= nhoff
+ sizeof(struct ipv6hdr
);
123 if (skb_copy_bits(skb
, nhoff
+ offsetof(struct ipv6hdr
, nexthdr
),
124 &pnum
, sizeof(pnum
)) != 0) {
125 pr_debug("ip6_conntrack_core: can't get nexthdr\n");
128 protoff
= nf_ct_ipv6_skip_exthdr(skb
, extoff
, &pnum
, skb
->len
- extoff
);
130 * (protoff == skb->len) mean that the packet doesn't have no data
131 * except of IPv6 & ext headers. but it's tracked anyway. - YK
133 if ((protoff
< 0) || (protoff
> skb
->len
)) {
134 pr_debug("ip6_conntrack_core: can't find proto in pkt\n");
143 static unsigned int ipv6_confirm(unsigned int hooknum
,
145 const struct net_device
*in
,
146 const struct net_device
*out
,
147 int (*okfn
)(struct sk_buff
*))
150 const struct nf_conn_help
*help
;
151 const struct nf_conntrack_helper
*helper
;
152 enum ip_conntrack_info ctinfo
;
153 unsigned int ret
, protoff
;
154 unsigned int extoff
= (u8
*)(ipv6_hdr(skb
) + 1) - skb
->data
;
155 unsigned char pnum
= ipv6_hdr(skb
)->nexthdr
;
158 /* This is where we call the helper: as the packet goes out. */
159 ct
= nf_ct_get(skb
, &ctinfo
);
160 if (!ct
|| ctinfo
== IP_CT_RELATED
+ IP_CT_IS_REPLY
)
163 help
= nfct_help(ct
);
166 /* rcu_read_lock()ed by nf_hook_slow */
167 helper
= rcu_dereference(help
->helper
);
171 protoff
= nf_ct_ipv6_skip_exthdr(skb
, extoff
, &pnum
,
173 if (protoff
> skb
->len
|| pnum
== NEXTHDR_FRAGMENT
) {
174 pr_debug("proto header not found\n");
178 ret
= helper
->help(skb
, protoff
, ct
, ctinfo
);
179 if (ret
!= NF_ACCEPT
)
182 /* We've seen it coming out the other side: confirm it */
183 return nf_conntrack_confirm(skb
);
186 static enum ip6_defrag_users
nf_ct6_defrag_user(unsigned int hooknum
,
189 if (hooknum
== NF_INET_PRE_ROUTING
)
190 return IP6_DEFRAG_CONNTRACK_IN
;
192 return IP6_DEFRAG_CONNTRACK_OUT
;
196 static unsigned int ipv6_defrag(unsigned int hooknum
,
198 const struct net_device
*in
,
199 const struct net_device
*out
,
200 int (*okfn
)(struct sk_buff
*))
202 struct sk_buff
*reasm
;
204 /* Previously seen (loopback)? */
208 reasm
= nf_ct_frag6_gather(skb
, nf_ct6_defrag_user(hooknum
, skb
));
213 /* error occured or not fragmented */
217 nf_ct_frag6_output(hooknum
, reasm
, (struct net_device
*)in
,
218 (struct net_device
*)out
, okfn
);
223 static unsigned int ipv6_conntrack_in(unsigned int hooknum
,
225 const struct net_device
*in
,
226 const struct net_device
*out
,
227 int (*okfn
)(struct sk_buff
*))
229 struct sk_buff
*reasm
= skb
->nfct_reasm
;
231 /* This packet is fragmented and has reassembled packet. */
233 /* Reassembled packet isn't parsed yet ? */
237 ret
= nf_conntrack_in(PF_INET6
, hooknum
, reasm
);
238 if (ret
!= NF_ACCEPT
)
241 nf_conntrack_get(reasm
->nfct
);
242 skb
->nfct
= reasm
->nfct
;
243 skb
->nfctinfo
= reasm
->nfctinfo
;
247 return nf_conntrack_in(PF_INET6
, hooknum
, skb
);
250 static unsigned int ipv6_conntrack_local(unsigned int hooknum
,
252 const struct net_device
*in
,
253 const struct net_device
*out
,
254 int (*okfn
)(struct sk_buff
*))
256 /* root is playing with raw sockets. */
257 if (skb
->len
< sizeof(struct ipv6hdr
)) {
259 printk("ipv6_conntrack_local: packet too short\n");
262 return ipv6_conntrack_in(hooknum
, skb
, in
, out
, okfn
);
265 static struct nf_hook_ops ipv6_conntrack_ops
[] __read_mostly
= {
268 .owner
= THIS_MODULE
,
270 .hooknum
= NF_INET_PRE_ROUTING
,
271 .priority
= NF_IP6_PRI_CONNTRACK_DEFRAG
,
274 .hook
= ipv6_conntrack_in
,
275 .owner
= THIS_MODULE
,
277 .hooknum
= NF_INET_PRE_ROUTING
,
278 .priority
= NF_IP6_PRI_CONNTRACK
,
281 .hook
= ipv6_conntrack_local
,
282 .owner
= THIS_MODULE
,
284 .hooknum
= NF_INET_LOCAL_OUT
,
285 .priority
= NF_IP6_PRI_CONNTRACK
,
289 .owner
= THIS_MODULE
,
291 .hooknum
= NF_INET_LOCAL_OUT
,
292 .priority
= NF_IP6_PRI_CONNTRACK_DEFRAG
,
295 .hook
= ipv6_confirm
,
296 .owner
= THIS_MODULE
,
298 .hooknum
= NF_INET_POST_ROUTING
,
299 .priority
= NF_IP6_PRI_LAST
,
302 .hook
= ipv6_confirm
,
303 .owner
= THIS_MODULE
,
305 .hooknum
= NF_INET_LOCAL_IN
,
306 .priority
= NF_IP6_PRI_LAST
-1,
310 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
312 #include <linux/netfilter/nfnetlink.h>
313 #include <linux/netfilter/nfnetlink_conntrack.h>
315 static int ipv6_tuple_to_nlattr(struct sk_buff
*skb
,
316 const struct nf_conntrack_tuple
*tuple
)
318 NLA_PUT(skb
, CTA_IP_V6_SRC
, sizeof(u_int32_t
) * 4,
320 NLA_PUT(skb
, CTA_IP_V6_DST
, sizeof(u_int32_t
) * 4,
328 static const struct nla_policy ipv6_nla_policy
[CTA_IP_MAX
+1] = {
329 [CTA_IP_V6_SRC
] = { .len
= sizeof(u_int32_t
)*4 },
330 [CTA_IP_V6_DST
] = { .len
= sizeof(u_int32_t
)*4 },
333 static int ipv6_nlattr_to_tuple(struct nlattr
*tb
[],
334 struct nf_conntrack_tuple
*t
)
336 if (!tb
[CTA_IP_V6_SRC
] || !tb
[CTA_IP_V6_DST
])
339 memcpy(&t
->src
.u3
.ip6
, nla_data(tb
[CTA_IP_V6_SRC
]),
340 sizeof(u_int32_t
) * 4);
341 memcpy(&t
->dst
.u3
.ip6
, nla_data(tb
[CTA_IP_V6_DST
]),
342 sizeof(u_int32_t
) * 4);
348 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 __read_mostly
= {
351 .pkt_to_tuple
= ipv6_pkt_to_tuple
,
352 .invert_tuple
= ipv6_invert_tuple
,
353 .print_tuple
= ipv6_print_tuple
,
354 .get_l4proto
= ipv6_get_l4proto
,
355 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
356 .tuple_to_nlattr
= ipv6_tuple_to_nlattr
,
357 .nlattr_to_tuple
= ipv6_nlattr_to_tuple
,
358 .nla_policy
= ipv6_nla_policy
,
361 .ctl_table_path
= nf_net_netfilter_sysctl_path
,
362 .ctl_table
= nf_ct_ipv6_sysctl_table
,
367 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6
));
368 MODULE_LICENSE("GPL");
369 MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>");
371 static int __init
nf_conntrack_l3proto_ipv6_init(void)
377 ret
= nf_ct_frag6_init();
379 printk("nf_conntrack_ipv6: can't initialize frag6.\n");
382 ret
= nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp6
);
384 printk("nf_conntrack_ipv6: can't register tcp.\n");
388 ret
= nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp6
);
390 printk("nf_conntrack_ipv6: can't register udp.\n");
394 ret
= nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmpv6
);
396 printk("nf_conntrack_ipv6: can't register icmpv6.\n");
400 ret
= nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv6
);
402 printk("nf_conntrack_ipv6: can't register ipv6\n");
406 ret
= nf_register_hooks(ipv6_conntrack_ops
,
407 ARRAY_SIZE(ipv6_conntrack_ops
));
409 printk("nf_conntrack_ipv6: can't register pre-routing defrag "
416 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6
);
418 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6
);
420 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6
);
422 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6
);
424 nf_ct_frag6_cleanup();
428 static void __exit
nf_conntrack_l3proto_ipv6_fini(void)
431 nf_unregister_hooks(ipv6_conntrack_ops
, ARRAY_SIZE(ipv6_conntrack_ops
));
432 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6
);
433 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6
);
434 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6
);
435 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6
);
436 nf_ct_frag6_cleanup();
439 module_init(nf_conntrack_l3proto_ipv6_init
);
440 module_exit(nf_conntrack_l3proto_ipv6_fini
);