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>
20 #include <net/inet_frag.h>
22 #include <linux/netfilter_bridge.h>
23 #include <linux/netfilter_ipv6.h>
24 #include <linux/netfilter_ipv6/ip6_tables.h>
25 #include <net/netfilter/nf_conntrack.h>
26 #include <net/netfilter/nf_conntrack_helper.h>
27 #include <net/netfilter/nf_conntrack_l4proto.h>
28 #include <net/netfilter/nf_conntrack_l3proto.h>
29 #include <net/netfilter/nf_conntrack_core.h>
30 #include <net/netfilter/nf_conntrack_zones.h>
31 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
32 #include <net/netfilter/nf_nat_helper.h>
33 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
34 #include <net/netfilter/nf_log.h>
36 static bool ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
37 struct nf_conntrack_tuple *tuple)
42 ap = skb_header_pointer(skb, nhoff + offsetof(struct ipv6hdr, saddr),
43 sizeof(_addrs), _addrs);
47 memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6));
48 memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6));
53 static bool ipv6_invert_tuple(struct nf_conntrack_tuple *tuple,
54 const struct nf_conntrack_tuple *orig)
56 memcpy(tuple->src.u3.ip6, orig->dst.u3.ip6, sizeof(tuple->src.u3.ip6));
57 memcpy(tuple->dst.u3.ip6, orig->src.u3.ip6, sizeof(tuple->dst.u3.ip6));
62 static int ipv6_print_tuple(struct seq_file *s,
63 const struct nf_conntrack_tuple *tuple)
65 return seq_printf(s, "src=%pI6 dst=%pI6 ",
66 tuple->src.u3.ip6, tuple->dst.u3.ip6);
69 static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
70 unsigned int *dataoff, u_int8_t *protonum)
72 unsigned int extoff = nhoff + sizeof(struct ipv6hdr);
77 if (skb_copy_bits(skb, nhoff + offsetof(struct ipv6hdr, nexthdr),
78 &nexthdr, sizeof(nexthdr)) != 0) {
79 pr_debug("ip6_conntrack_core: can't get nexthdr\n");
82 protoff = ipv6_skip_exthdr(skb, extoff, &nexthdr, &frag_off);
84 * (protoff == skb->len) means the packet has not data, just
85 * IPv6 and possibly extensions headers, but it is tracked anyway
87 if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
88 pr_debug("ip6_conntrack_core: can't find proto in pkt\n");
97 static unsigned int ipv6_helper(unsigned int hooknum,
99 const struct net_device *in,
100 const struct net_device *out,
101 int (*okfn)(struct sk_buff *))
104 const struct nf_conn_help *help;
105 const struct nf_conntrack_helper *helper;
106 enum ip_conntrack_info ctinfo;
111 /* This is where we call the helper: as the packet goes out. */
112 ct = nf_ct_get(skb, &ctinfo);
113 if (!ct || ctinfo == IP_CT_RELATED_REPLY)
116 help = nfct_help(ct);
119 /* rcu_read_lock()ed by nf_hook_slow */
120 helper = rcu_dereference(help->helper);
124 nexthdr = ipv6_hdr(skb)->nexthdr;
125 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
127 if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
128 pr_debug("proto header not found\n");
132 return helper->help(skb, protoff, ct, ctinfo);
135 static unsigned int ipv6_confirm(unsigned int hooknum,
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 unsigned char pnum = ipv6_hdr(skb)->nexthdr;
147 ct = nf_ct_get(skb, &ctinfo);
148 if (!ct || ctinfo == IP_CT_RELATED_REPLY)
151 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum,
153 if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
154 pr_debug("proto header not found\n");
158 /* adjust seqs for loopback traffic only in outgoing direction */
159 if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
160 !nf_is_loopback_packet(skb)) {
161 typeof(nf_nat_seq_adjust_hook) seq_adjust;
163 seq_adjust = rcu_dereference(nf_nat_seq_adjust_hook);
165 !seq_adjust(skb, ct, ctinfo, protoff)) {
166 NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
171 /* We've seen it coming out the other side: confirm it */
172 return nf_conntrack_confirm(skb);
175 static unsigned int __ipv6_conntrack_in(struct net *net,
176 unsigned int hooknum,
178 const struct net_device *in,
179 const struct net_device *out,
180 int (*okfn)(struct sk_buff *))
182 struct sk_buff *reasm = skb->nfct_reasm;
183 const struct nf_conn_help *help;
185 enum ip_conntrack_info ctinfo;
187 /* This packet is fragmented and has reassembled packet. */
189 /* Reassembled packet isn't parsed yet ? */
193 ret = nf_conntrack_in(net, PF_INET6, hooknum, reasm);
194 if (ret != NF_ACCEPT)
198 /* Conntrack helpers need the entire reassembled packet in the
199 * POST_ROUTING hook. In case of unconfirmed connections NAT
200 * might reassign a helper, so the entire packet is also
203 ct = nf_ct_get(reasm, &ctinfo);
204 if (ct != NULL && !nf_ct_is_untracked(ct)) {
205 help = nfct_help(ct);
206 if ((help && help->helper) || !nf_ct_is_confirmed(ct)) {
207 nf_conntrack_get_reasm(skb);
208 NF_HOOK_THRESH(NFPROTO_IPV6, hooknum, reasm,
209 (struct net_device *)in,
210 (struct net_device *)out,
211 okfn, NF_IP6_PRI_CONNTRACK + 1);
212 return NF_DROP_ERR(-ECANCELED);
216 nf_conntrack_get(reasm->nfct);
217 skb->nfct = reasm->nfct;
218 skb->nfctinfo = reasm->nfctinfo;
222 return nf_conntrack_in(net, PF_INET6, hooknum, skb);
225 static unsigned int ipv6_conntrack_in(unsigned int hooknum,
227 const struct net_device *in,
228 const struct net_device *out,
229 int (*okfn)(struct sk_buff *))
231 return __ipv6_conntrack_in(dev_net(in), hooknum, skb, in, out, okfn);
234 static unsigned int ipv6_conntrack_local(unsigned int hooknum,
236 const struct net_device *in,
237 const struct net_device *out,
238 int (*okfn)(struct sk_buff *))
240 /* root is playing with raw sockets. */
241 if (skb->len < sizeof(struct ipv6hdr)) {
242 net_notice_ratelimited("ipv6_conntrack_local: packet too short\n");
245 return __ipv6_conntrack_in(dev_net(out), hooknum, skb, in, out, okfn);
248 static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
250 .hook = ipv6_conntrack_in,
251 .owner = THIS_MODULE,
253 .hooknum = NF_INET_PRE_ROUTING,
254 .priority = NF_IP6_PRI_CONNTRACK,
257 .hook = ipv6_conntrack_local,
258 .owner = THIS_MODULE,
260 .hooknum = NF_INET_LOCAL_OUT,
261 .priority = NF_IP6_PRI_CONNTRACK,
265 .owner = THIS_MODULE,
267 .hooknum = NF_INET_POST_ROUTING,
268 .priority = NF_IP6_PRI_CONNTRACK_HELPER,
271 .hook = ipv6_confirm,
272 .owner = THIS_MODULE,
274 .hooknum = NF_INET_POST_ROUTING,
275 .priority = NF_IP6_PRI_LAST,
279 .owner = THIS_MODULE,
281 .hooknum = NF_INET_LOCAL_IN,
282 .priority = NF_IP6_PRI_CONNTRACK_HELPER,
285 .hook = ipv6_confirm,
286 .owner = THIS_MODULE,
288 .hooknum = NF_INET_LOCAL_IN,
289 .priority = NF_IP6_PRI_LAST-1,
294 ipv6_getorigdst(struct sock *sk, int optval, void __user *user, int *len)
296 const struct inet_sock *inet = inet_sk(sk);
297 const struct ipv6_pinfo *inet6 = inet6_sk(sk);
298 const struct nf_conntrack_tuple_hash *h;
299 struct sockaddr_in6 sin6;
300 struct nf_conntrack_tuple tuple = { .src.l3num = NFPROTO_IPV6 };
303 tuple.src.u3.in6 = inet6->rcv_saddr;
304 tuple.src.u.tcp.port = inet->inet_sport;
305 tuple.dst.u3.in6 = inet6->daddr;
306 tuple.dst.u.tcp.port = inet->inet_dport;
307 tuple.dst.protonum = sk->sk_protocol;
309 if (sk->sk_protocol != IPPROTO_TCP && sk->sk_protocol != IPPROTO_SCTP)
312 if (*len < 0 || (unsigned int) *len < sizeof(sin6))
315 h = nf_conntrack_find_get(sock_net(sk), NF_CT_DEFAULT_ZONE, &tuple);
317 pr_debug("IP6T_SO_ORIGINAL_DST: Can't find %pI6c/%u-%pI6c/%u.\n",
318 &tuple.src.u3.ip6, ntohs(tuple.src.u.tcp.port),
319 &tuple.dst.u3.ip6, ntohs(tuple.dst.u.tcp.port));
323 ct = nf_ct_tuplehash_to_ctrack(h);
325 sin6.sin6_family = AF_INET6;
326 sin6.sin6_port = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.tcp.port;
327 sin6.sin6_flowinfo = inet6->flow_label & IPV6_FLOWINFO_MASK;
328 memcpy(&sin6.sin6_addr,
329 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in6,
330 sizeof(sin6.sin6_addr));
334 if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
335 sin6.sin6_scope_id = sk->sk_bound_dev_if;
337 sin6.sin6_scope_id = 0;
339 return copy_to_user(user, &sin6, sizeof(sin6)) ? -EFAULT : 0;
342 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
344 #include <linux/netfilter/nfnetlink.h>
345 #include <linux/netfilter/nfnetlink_conntrack.h>
347 static int ipv6_tuple_to_nlattr(struct sk_buff *skb,
348 const struct nf_conntrack_tuple *tuple)
350 if (nla_put(skb, CTA_IP_V6_SRC, sizeof(u_int32_t) * 4,
351 &tuple->src.u3.ip6) ||
352 nla_put(skb, CTA_IP_V6_DST, sizeof(u_int32_t) * 4,
354 goto nla_put_failure;
361 static const struct nla_policy ipv6_nla_policy[CTA_IP_MAX+1] = {
362 [CTA_IP_V6_SRC] = { .len = sizeof(u_int32_t)*4 },
363 [CTA_IP_V6_DST] = { .len = sizeof(u_int32_t)*4 },
366 static int ipv6_nlattr_to_tuple(struct nlattr *tb[],
367 struct nf_conntrack_tuple *t)
369 if (!tb[CTA_IP_V6_SRC] || !tb[CTA_IP_V6_DST])
372 memcpy(&t->src.u3.ip6, nla_data(tb[CTA_IP_V6_SRC]),
373 sizeof(u_int32_t) * 4);
374 memcpy(&t->dst.u3.ip6, nla_data(tb[CTA_IP_V6_DST]),
375 sizeof(u_int32_t) * 4);
380 static int ipv6_nlattr_tuple_size(void)
382 return nla_policy_len(ipv6_nla_policy, CTA_IP_MAX + 1);
386 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 __read_mostly = {
389 .pkt_to_tuple = ipv6_pkt_to_tuple,
390 .invert_tuple = ipv6_invert_tuple,
391 .print_tuple = ipv6_print_tuple,
392 .get_l4proto = ipv6_get_l4proto,
393 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
394 .tuple_to_nlattr = ipv6_tuple_to_nlattr,
395 .nlattr_tuple_size = ipv6_nlattr_tuple_size,
396 .nlattr_to_tuple = ipv6_nlattr_to_tuple,
397 .nla_policy = ipv6_nla_policy,
402 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6));
403 MODULE_LICENSE("GPL");
404 MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>");
406 static struct nf_sockopt_ops so_getorigdst6 = {
408 .get_optmin = IP6T_SO_ORIGINAL_DST,
409 .get_optmax = IP6T_SO_ORIGINAL_DST + 1,
410 .get = ipv6_getorigdst,
411 .owner = THIS_MODULE,
414 static int ipv6_net_init(struct net *net)
418 ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_tcp6);
420 pr_err("nf_conntrack_tcp6: pernet registration failed\n");
423 ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_udp6);
425 pr_err("nf_conntrack_udp6: pernet registration failed\n");
428 ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_icmpv6);
430 pr_err("nf_conntrack_icmp6: pernet registration failed\n");
433 ret = nf_ct_l3proto_pernet_register(net, &nf_conntrack_l3proto_ipv6);
435 pr_err("nf_conntrack_ipv6: pernet registration failed.\n");
440 nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_icmpv6);
442 nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_udp6);
444 nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_tcp6);
449 static void ipv6_net_exit(struct net *net)
451 nf_ct_l3proto_pernet_unregister(net, &nf_conntrack_l3proto_ipv6);
452 nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_icmpv6);
453 nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_udp6);
454 nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_tcp6);
457 static struct pernet_operations ipv6_net_ops = {
458 .init = ipv6_net_init,
459 .exit = ipv6_net_exit,
462 static int __init nf_conntrack_l3proto_ipv6_init(void)
467 nf_defrag_ipv6_enable();
469 ret = nf_register_sockopt(&so_getorigdst6);
471 pr_err("Unable to register netfilter socket option\n");
475 ret = register_pernet_subsys(&ipv6_net_ops);
477 goto cleanup_sockopt;
479 ret = nf_register_hooks(ipv6_conntrack_ops,
480 ARRAY_SIZE(ipv6_conntrack_ops));
482 pr_err("nf_conntrack_ipv6: can't register pre-routing defrag "
487 ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_tcp6);
489 pr_err("nf_conntrack_ipv6: can't register tcp6 proto.\n");
493 ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_udp6);
495 pr_err("nf_conntrack_ipv6: can't register udp6 proto.\n");
499 ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_icmpv6);
501 pr_err("nf_conntrack_ipv6: can't register icmpv6 proto.\n");
505 ret = nf_ct_l3proto_register(&nf_conntrack_l3proto_ipv6);
507 pr_err("nf_conntrack_ipv6: can't register ipv6 proto.\n");
513 nf_ct_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
515 nf_ct_l4proto_unregister(&nf_conntrack_l4proto_udp6);
517 nf_ct_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
519 nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops));
521 unregister_pernet_subsys(&ipv6_net_ops);
523 nf_unregister_sockopt(&so_getorigdst6);
527 static void __exit nf_conntrack_l3proto_ipv6_fini(void)
530 nf_ct_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
531 nf_ct_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
532 nf_ct_l4proto_unregister(&nf_conntrack_l4proto_udp6);
533 nf_ct_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
534 nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops));
535 unregister_pernet_subsys(&ipv6_net_ops);
536 nf_unregister_sockopt(&so_getorigdst6);
539 module_init(nf_conntrack_l3proto_ipv6_init);
540 module_exit(nf_conntrack_l3proto_ipv6_fini);