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>
22 #include <linux/netfilter_ipv6.h>
23 #include <net/netfilter/nf_conntrack.h>
24 #include <net/netfilter/nf_conntrack_helper.h>
25 #include <net/netfilter/nf_conntrack_l4proto.h>
26 #include <net/netfilter/nf_conntrack_l3proto.h>
27 #include <net/netfilter/nf_conntrack_core.h>
29 static int ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
30 struct nf_conntrack_tuple *tuple)
32 u_int32_t _addrs[8], *ap;
34 ap = skb_header_pointer(skb, nhoff + offsetof(struct ipv6hdr, saddr),
35 sizeof(_addrs), _addrs);
39 memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6));
40 memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6));
45 static int ipv6_invert_tuple(struct nf_conntrack_tuple *tuple,
46 const struct nf_conntrack_tuple *orig)
48 memcpy(tuple->src.u3.ip6, orig->dst.u3.ip6, sizeof(tuple->src.u3.ip6));
49 memcpy(tuple->dst.u3.ip6, orig->src.u3.ip6, sizeof(tuple->dst.u3.ip6));
54 static int ipv6_print_tuple(struct seq_file *s,
55 const struct nf_conntrack_tuple *tuple)
57 return seq_printf(s, "src=" NIP6_FMT " dst=" NIP6_FMT " ",
58 NIP6(*((struct in6_addr *)tuple->src.u3.ip6)),
59 NIP6(*((struct in6_addr *)tuple->dst.u3.ip6)));
62 static int ipv6_print_conntrack(struct seq_file *s,
63 const struct nf_conn *conntrack)
69 * Based on ipv6_skip_exthdr() in net/ipv6/exthdr.c
71 * This function parses (probably truncated) exthdr set "hdr"
72 * of length "len". "nexthdrp" initially points to some place,
73 * where type of the first header can be found.
75 * It skips all well-known exthdrs, and returns pointer to the start
76 * of unparsable area i.e. the first header with unknown type.
77 * if success, *nexthdr is updated by type/protocol of this header.
79 * NOTES: - it may return pointer pointing beyond end of packet,
80 * if the last recognized header is truncated in the middle.
81 * - if packet is truncated, so that all parsed headers are skipped,
83 * - if packet is fragmented, return pointer of the fragment header.
84 * - ESP is unparsable for now and considered like
85 * normal payload protocol.
86 * - Note also special handling of AUTH header. Thanks to IPsec wizards.
89 static int nf_ct_ipv6_skip_exthdr(const struct sk_buff *skb, int start,
90 u8 *nexthdrp, int len)
92 u8 nexthdr = *nexthdrp;
94 while (ipv6_ext_hdr(nexthdr)) {
95 struct ipv6_opt_hdr hdr;
98 if (len < (int)sizeof(struct ipv6_opt_hdr))
100 if (nexthdr == NEXTHDR_NONE)
102 if (nexthdr == NEXTHDR_FRAGMENT)
104 if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
106 if (nexthdr == NEXTHDR_AUTH)
107 hdrlen = (hdr.hdrlen+2)<<2;
109 hdrlen = ipv6_optlen(&hdr);
111 nexthdr = hdr.nexthdr;
120 static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
121 unsigned int *dataoff, u_int8_t *protonum)
123 unsigned int extoff = nhoff + sizeof(struct ipv6hdr);
127 if (skb_copy_bits(skb, nhoff + offsetof(struct ipv6hdr, nexthdr),
128 &pnum, sizeof(pnum)) != 0) {
129 pr_debug("ip6_conntrack_core: can't get nexthdr\n");
132 protoff = nf_ct_ipv6_skip_exthdr(skb, extoff, &pnum, skb->len - extoff);
134 * (protoff == skb->len) mean that the packet doesn't have no data
135 * except of IPv6 & ext headers. but it's tracked anyway. - YK
137 if ((protoff < 0) || (protoff > skb->len)) {
138 pr_debug("ip6_conntrack_core: can't find proto in pkt\n");
147 static unsigned int ipv6_confirm(unsigned int hooknum,
148 struct sk_buff **pskb,
149 const struct net_device *in,
150 const struct net_device *out,
151 int (*okfn)(struct sk_buff *))
154 struct nf_conn_help *help;
155 struct nf_conntrack_helper *helper;
156 enum ip_conntrack_info ctinfo;
157 unsigned int ret, protoff;
158 unsigned int extoff = (u8 *)(ipv6_hdr(*pskb) + 1) - (*pskb)->data;
159 unsigned char pnum = ipv6_hdr(*pskb)->nexthdr;
162 /* This is where we call the helper: as the packet goes out. */
163 ct = nf_ct_get(*pskb, &ctinfo);
164 if (!ct || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY)
167 help = nfct_help(ct);
170 /* rcu_read_lock()ed by nf_hook_slow */
171 helper = rcu_dereference(help->helper);
175 protoff = nf_ct_ipv6_skip_exthdr(*pskb, extoff, &pnum,
176 (*pskb)->len - extoff);
177 if (protoff > (*pskb)->len || pnum == NEXTHDR_FRAGMENT) {
178 pr_debug("proto header not found\n");
182 ret = helper->help(pskb, protoff, ct, ctinfo);
183 if (ret != NF_ACCEPT)
186 /* We've seen it coming out the other side: confirm it */
187 return nf_conntrack_confirm(pskb);
190 static unsigned int ipv6_defrag(unsigned int hooknum,
191 struct sk_buff **pskb,
192 const struct net_device *in,
193 const struct net_device *out,
194 int (*okfn)(struct sk_buff *))
196 struct sk_buff *reasm;
198 /* Previously seen (loopback)? */
202 reasm = nf_ct_frag6_gather(*pskb);
208 /* error occured or not fragmented */
212 nf_ct_frag6_output(hooknum, reasm, (struct net_device *)in,
213 (struct net_device *)out, okfn);
218 static unsigned int ipv6_conntrack_in(unsigned int hooknum,
219 struct sk_buff **pskb,
220 const struct net_device *in,
221 const struct net_device *out,
222 int (*okfn)(struct sk_buff *))
224 struct sk_buff *reasm = (*pskb)->nfct_reasm;
226 /* This packet is fragmented and has reassembled packet. */
228 /* Reassembled packet isn't parsed yet ? */
232 ret = nf_conntrack_in(PF_INET6, hooknum, &reasm);
233 if (ret != NF_ACCEPT)
236 nf_conntrack_get(reasm->nfct);
237 (*pskb)->nfct = reasm->nfct;
238 (*pskb)->nfctinfo = reasm->nfctinfo;
242 return nf_conntrack_in(PF_INET6, hooknum, pskb);
245 static unsigned int ipv6_conntrack_local(unsigned int hooknum,
246 struct sk_buff **pskb,
247 const struct net_device *in,
248 const struct net_device *out,
249 int (*okfn)(struct sk_buff *))
251 /* root is playing with raw sockets. */
252 if ((*pskb)->len < sizeof(struct ipv6hdr)) {
254 printk("ipv6_conntrack_local: packet too short\n");
257 return ipv6_conntrack_in(hooknum, pskb, in, out, okfn);
260 static struct nf_hook_ops ipv6_conntrack_ops[] = {
263 .owner = THIS_MODULE,
265 .hooknum = NF_IP6_PRE_ROUTING,
266 .priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
269 .hook = ipv6_conntrack_in,
270 .owner = THIS_MODULE,
272 .hooknum = NF_IP6_PRE_ROUTING,
273 .priority = NF_IP6_PRI_CONNTRACK,
276 .hook = ipv6_conntrack_local,
277 .owner = THIS_MODULE,
279 .hooknum = NF_IP6_LOCAL_OUT,
280 .priority = NF_IP6_PRI_CONNTRACK,
284 .owner = THIS_MODULE,
286 .hooknum = NF_IP6_LOCAL_OUT,
287 .priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
290 .hook = ipv6_confirm,
291 .owner = THIS_MODULE,
293 .hooknum = NF_IP6_POST_ROUTING,
294 .priority = NF_IP6_PRI_LAST,
297 .hook = ipv6_confirm,
298 .owner = THIS_MODULE,
300 .hooknum = NF_IP6_LOCAL_IN,
301 .priority = NF_IP6_PRI_LAST-1,
306 static ctl_table nf_ct_ipv6_sysctl_table[] = {
308 .ctl_name = NET_NF_CONNTRACK_FRAG6_TIMEOUT,
309 .procname = "nf_conntrack_frag6_timeout",
310 .data = &nf_ct_frag6_timeout,
311 .maxlen = sizeof(unsigned int),
313 .proc_handler = &proc_dointvec_jiffies,
316 .ctl_name = NET_NF_CONNTRACK_FRAG6_LOW_THRESH,
317 .procname = "nf_conntrack_frag6_low_thresh",
318 .data = &nf_ct_frag6_low_thresh,
319 .maxlen = sizeof(unsigned int),
321 .proc_handler = &proc_dointvec,
324 .ctl_name = NET_NF_CONNTRACK_FRAG6_HIGH_THRESH,
325 .procname = "nf_conntrack_frag6_high_thresh",
326 .data = &nf_ct_frag6_high_thresh,
327 .maxlen = sizeof(unsigned int),
329 .proc_handler = &proc_dointvec,
335 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
337 #include <linux/netfilter/nfnetlink.h>
338 #include <linux/netfilter/nfnetlink_conntrack.h>
340 static int ipv6_tuple_to_nfattr(struct sk_buff *skb,
341 const struct nf_conntrack_tuple *tuple)
343 NFA_PUT(skb, CTA_IP_V6_SRC, sizeof(u_int32_t) * 4,
345 NFA_PUT(skb, CTA_IP_V6_DST, sizeof(u_int32_t) * 4,
353 static const size_t cta_min_ip[CTA_IP_MAX] = {
354 [CTA_IP_V6_SRC-1] = sizeof(u_int32_t)*4,
355 [CTA_IP_V6_DST-1] = sizeof(u_int32_t)*4,
358 static int ipv6_nfattr_to_tuple(struct nfattr *tb[],
359 struct nf_conntrack_tuple *t)
361 if (!tb[CTA_IP_V6_SRC-1] || !tb[CTA_IP_V6_DST-1])
364 if (nfattr_bad_size(tb, CTA_IP_MAX, cta_min_ip))
367 memcpy(&t->src.u3.ip6, NFA_DATA(tb[CTA_IP_V6_SRC-1]),
368 sizeof(u_int32_t) * 4);
369 memcpy(&t->dst.u3.ip6, NFA_DATA(tb[CTA_IP_V6_DST-1]),
370 sizeof(u_int32_t) * 4);
376 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 __read_mostly = {
379 .pkt_to_tuple = ipv6_pkt_to_tuple,
380 .invert_tuple = ipv6_invert_tuple,
381 .print_tuple = ipv6_print_tuple,
382 .print_conntrack = ipv6_print_conntrack,
383 .get_l4proto = ipv6_get_l4proto,
384 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
385 .tuple_to_nfattr = ipv6_tuple_to_nfattr,
386 .nfattr_to_tuple = ipv6_nfattr_to_tuple,
389 .ctl_table_path = nf_net_netfilter_sysctl_path,
390 .ctl_table = nf_ct_ipv6_sysctl_table,
395 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6));
396 MODULE_LICENSE("GPL");
397 MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>");
399 static int __init nf_conntrack_l3proto_ipv6_init(void)
405 ret = nf_ct_frag6_init();
407 printk("nf_conntrack_ipv6: can't initialize frag6.\n");
410 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp6);
412 printk("nf_conntrack_ipv6: can't register tcp.\n");
416 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp6);
418 printk("nf_conntrack_ipv6: can't register udp.\n");
422 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmpv6);
424 printk("nf_conntrack_ipv6: can't register icmpv6.\n");
428 ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv6);
430 printk("nf_conntrack_ipv6: can't register ipv6\n");
434 ret = nf_register_hooks(ipv6_conntrack_ops,
435 ARRAY_SIZE(ipv6_conntrack_ops));
437 printk("nf_conntrack_ipv6: can't register pre-routing defrag "
444 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
446 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
448 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6);
450 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
452 nf_ct_frag6_cleanup();
456 static void __exit nf_conntrack_l3proto_ipv6_fini(void)
459 nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops));
460 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
461 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
462 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6);
463 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
464 nf_ct_frag6_cleanup();
467 module_init(nf_conntrack_l3proto_ipv6_init);
468 module_exit(nf_conntrack_l3proto_ipv6_fini);