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>
29 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
31 static bool ipv6_pkt_to_tuple(const struct sk_buff
*skb
, unsigned int nhoff
,
32 struct nf_conntrack_tuple
*tuple
)
37 ap
= skb_header_pointer(skb
, nhoff
+ offsetof(struct ipv6hdr
, saddr
),
38 sizeof(_addrs
), _addrs
);
42 memcpy(tuple
->src
.u3
.ip6
, ap
, sizeof(tuple
->src
.u3
.ip6
));
43 memcpy(tuple
->dst
.u3
.ip6
, ap
+ 4, sizeof(tuple
->dst
.u3
.ip6
));
48 static bool ipv6_invert_tuple(struct nf_conntrack_tuple
*tuple
,
49 const struct nf_conntrack_tuple
*orig
)
51 memcpy(tuple
->src
.u3
.ip6
, orig
->dst
.u3
.ip6
, sizeof(tuple
->src
.u3
.ip6
));
52 memcpy(tuple
->dst
.u3
.ip6
, orig
->src
.u3
.ip6
, sizeof(tuple
->dst
.u3
.ip6
));
57 static int ipv6_print_tuple(struct seq_file
*s
,
58 const struct nf_conntrack_tuple
*tuple
)
60 return seq_printf(s
, "src=%pI6 dst=%pI6 ",
61 tuple
->src
.u3
.ip6
, 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 unsigned int ipv6_defrag(unsigned int hooknum
,
188 const struct net_device
*in
,
189 const struct net_device
*out
,
190 int (*okfn
)(struct sk_buff
*))
192 struct sk_buff
*reasm
;
194 /* Previously seen (loopback)? */
198 reasm
= nf_ct_frag6_gather(skb
);
204 /* error occured or not fragmented */
208 nf_ct_frag6_output(hooknum
, reasm
, (struct net_device
*)in
,
209 (struct net_device
*)out
, okfn
);
214 static unsigned int __ipv6_conntrack_in(struct net
*net
,
215 unsigned int hooknum
,
217 int (*okfn
)(struct sk_buff
*))
219 struct sk_buff
*reasm
= skb
->nfct_reasm
;
221 /* This packet is fragmented and has reassembled packet. */
223 /* Reassembled packet isn't parsed yet ? */
227 ret
= nf_conntrack_in(net
, PF_INET6
, hooknum
, reasm
);
228 if (ret
!= NF_ACCEPT
)
231 nf_conntrack_get(reasm
->nfct
);
232 skb
->nfct
= reasm
->nfct
;
233 skb
->nfctinfo
= reasm
->nfctinfo
;
237 return nf_conntrack_in(net
, PF_INET6
, hooknum
, skb
);
240 static unsigned int ipv6_conntrack_in(unsigned int hooknum
,
242 const struct net_device
*in
,
243 const struct net_device
*out
,
244 int (*okfn
)(struct sk_buff
*))
246 return __ipv6_conntrack_in(dev_net(in
), hooknum
, skb
, okfn
);
249 static unsigned int ipv6_conntrack_local(unsigned int hooknum
,
251 const struct net_device
*in
,
252 const struct net_device
*out
,
253 int (*okfn
)(struct sk_buff
*))
255 /* root is playing with raw sockets. */
256 if (skb
->len
< sizeof(struct ipv6hdr
)) {
258 printk("ipv6_conntrack_local: packet too short\n");
261 return __ipv6_conntrack_in(dev_net(out
), hooknum
, skb
, okfn
);
264 static struct nf_hook_ops ipv6_conntrack_ops
[] __read_mostly
= {
267 .owner
= THIS_MODULE
,
269 .hooknum
= NF_INET_PRE_ROUTING
,
270 .priority
= NF_IP6_PRI_CONNTRACK_DEFRAG
,
273 .hook
= ipv6_conntrack_in
,
274 .owner
= THIS_MODULE
,
276 .hooknum
= NF_INET_PRE_ROUTING
,
277 .priority
= NF_IP6_PRI_CONNTRACK
,
280 .hook
= ipv6_conntrack_local
,
281 .owner
= THIS_MODULE
,
283 .hooknum
= NF_INET_LOCAL_OUT
,
284 .priority
= NF_IP6_PRI_CONNTRACK
,
288 .owner
= THIS_MODULE
,
290 .hooknum
= NF_INET_LOCAL_OUT
,
291 .priority
= NF_IP6_PRI_CONNTRACK_DEFRAG
,
294 .hook
= ipv6_confirm
,
295 .owner
= THIS_MODULE
,
297 .hooknum
= NF_INET_POST_ROUTING
,
298 .priority
= NF_IP6_PRI_LAST
,
301 .hook
= ipv6_confirm
,
302 .owner
= THIS_MODULE
,
304 .hooknum
= NF_INET_LOCAL_IN
,
305 .priority
= NF_IP6_PRI_LAST
-1,
309 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
311 #include <linux/netfilter/nfnetlink.h>
312 #include <linux/netfilter/nfnetlink_conntrack.h>
314 static int ipv6_tuple_to_nlattr(struct sk_buff
*skb
,
315 const struct nf_conntrack_tuple
*tuple
)
317 NLA_PUT(skb
, CTA_IP_V6_SRC
, sizeof(u_int32_t
) * 4,
319 NLA_PUT(skb
, CTA_IP_V6_DST
, sizeof(u_int32_t
) * 4,
327 static const struct nla_policy ipv6_nla_policy
[CTA_IP_MAX
+1] = {
328 [CTA_IP_V6_SRC
] = { .len
= sizeof(u_int32_t
)*4 },
329 [CTA_IP_V6_DST
] = { .len
= sizeof(u_int32_t
)*4 },
332 static int ipv6_nlattr_to_tuple(struct nlattr
*tb
[],
333 struct nf_conntrack_tuple
*t
)
335 if (!tb
[CTA_IP_V6_SRC
] || !tb
[CTA_IP_V6_DST
])
338 memcpy(&t
->src
.u3
.ip6
, nla_data(tb
[CTA_IP_V6_SRC
]),
339 sizeof(u_int32_t
) * 4);
340 memcpy(&t
->dst
.u3
.ip6
, nla_data(tb
[CTA_IP_V6_DST
]),
341 sizeof(u_int32_t
) * 4);
346 static int ipv6_nlattr_tuple_size(void)
348 return nla_policy_len(ipv6_nla_policy
, CTA_IP_MAX
+ 1);
352 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 __read_mostly
= {
355 .pkt_to_tuple
= ipv6_pkt_to_tuple
,
356 .invert_tuple
= ipv6_invert_tuple
,
357 .print_tuple
= ipv6_print_tuple
,
358 .get_l4proto
= ipv6_get_l4proto
,
359 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
360 .tuple_to_nlattr
= ipv6_tuple_to_nlattr
,
361 .nlattr_tuple_size
= ipv6_nlattr_tuple_size
,
362 .nlattr_to_tuple
= ipv6_nlattr_to_tuple
,
363 .nla_policy
= ipv6_nla_policy
,
366 .ctl_table_path
= nf_net_netfilter_sysctl_path
,
367 .ctl_table
= nf_ct_ipv6_sysctl_table
,
372 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6
));
373 MODULE_LICENSE("GPL");
374 MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>");
376 static int __init
nf_conntrack_l3proto_ipv6_init(void)
382 ret
= nf_ct_frag6_init();
384 printk("nf_conntrack_ipv6: can't initialize frag6.\n");
387 ret
= nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp6
);
389 printk("nf_conntrack_ipv6: can't register tcp.\n");
393 ret
= nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp6
);
395 printk("nf_conntrack_ipv6: can't register udp.\n");
399 ret
= nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmpv6
);
401 printk("nf_conntrack_ipv6: can't register icmpv6.\n");
405 ret
= nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv6
);
407 printk("nf_conntrack_ipv6: can't register ipv6\n");
411 ret
= nf_register_hooks(ipv6_conntrack_ops
,
412 ARRAY_SIZE(ipv6_conntrack_ops
));
414 printk("nf_conntrack_ipv6: can't register pre-routing defrag "
421 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6
);
423 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6
);
425 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6
);
427 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6
);
429 nf_ct_frag6_cleanup();
433 static void __exit
nf_conntrack_l3proto_ipv6_fini(void)
436 nf_unregister_hooks(ipv6_conntrack_ops
, ARRAY_SIZE(ipv6_conntrack_ops
));
437 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6
);
438 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6
);
439 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6
);
440 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6
);
441 nf_ct_frag6_cleanup();
444 module_init(nf_conntrack_l3proto_ipv6_init
);
445 module_exit(nf_conntrack_l3proto_ipv6_fini
);