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/nf_conntrack_seqadj.h>
32 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
33 #include <net/netfilter/nf_nat_helper.h>
34 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
35 #include <net/netfilter/nf_log.h>
37 static bool ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
38 struct nf_conntrack_tuple *tuple)
43 ap = skb_header_pointer(skb, nhoff + offsetof(struct ipv6hdr, saddr),
44 sizeof(_addrs), _addrs);
48 memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6));
49 memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6));
54 static bool ipv6_invert_tuple(struct nf_conntrack_tuple *tuple,
55 const struct nf_conntrack_tuple *orig)
57 memcpy(tuple->src.u3.ip6, orig->dst.u3.ip6, sizeof(tuple->src.u3.ip6));
58 memcpy(tuple->dst.u3.ip6, orig->src.u3.ip6, sizeof(tuple->dst.u3.ip6));
63 static int ipv6_print_tuple(struct seq_file *s,
64 const struct nf_conntrack_tuple *tuple)
66 return seq_printf(s, "src=%pI6 dst=%pI6 ",
67 tuple->src.u3.ip6, tuple->dst.u3.ip6);
70 static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
71 unsigned int *dataoff, u_int8_t *protonum)
73 unsigned int extoff = nhoff + sizeof(struct ipv6hdr);
78 if (skb_copy_bits(skb, nhoff + offsetof(struct ipv6hdr, nexthdr),
79 &nexthdr, sizeof(nexthdr)) != 0) {
80 pr_debug("ip6_conntrack_core: can't get nexthdr\n");
83 protoff = ipv6_skip_exthdr(skb, extoff, &nexthdr, &frag_off);
85 * (protoff == skb->len) means the packet has not data, just
86 * IPv6 and possibly extensions headers, but it is tracked anyway
88 if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
89 pr_debug("ip6_conntrack_core: can't find proto in pkt\n");
98 static unsigned int ipv6_helper(const struct nf_hook_ops *ops,
100 const struct net_device *in,
101 const struct net_device *out,
102 int (*okfn)(struct sk_buff *))
105 const struct nf_conn_help *help;
106 const struct nf_conntrack_helper *helper;
107 enum ip_conntrack_info ctinfo;
112 /* This is where we call the helper: as the packet goes out. */
113 ct = nf_ct_get(skb, &ctinfo);
114 if (!ct || ctinfo == IP_CT_RELATED_REPLY)
117 help = nfct_help(ct);
120 /* rcu_read_lock()ed by nf_hook_slow */
121 helper = rcu_dereference(help->helper);
125 nexthdr = ipv6_hdr(skb)->nexthdr;
126 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
128 if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
129 pr_debug("proto header not found\n");
133 return helper->help(skb, protoff, ct, ctinfo);
136 static unsigned int ipv6_confirm(const struct nf_hook_ops *ops,
138 const struct net_device *in,
139 const struct net_device *out,
140 int (*okfn)(struct sk_buff *))
143 enum ip_conntrack_info ctinfo;
144 unsigned char pnum = ipv6_hdr(skb)->nexthdr;
148 ct = nf_ct_get(skb, &ctinfo);
149 if (!ct || ctinfo == IP_CT_RELATED_REPLY)
152 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum,
154 if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
155 pr_debug("proto header not found\n");
159 /* adjust seqs for loopback traffic only in outgoing direction */
160 if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
161 !nf_is_loopback_packet(skb)) {
162 if (!nf_ct_seq_adjust(skb, ct, ctinfo, protoff)) {
163 NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
168 /* We've seen it coming out the other side: confirm it */
169 return nf_conntrack_confirm(skb);
172 static unsigned int __ipv6_conntrack_in(struct net *net,
173 unsigned int hooknum,
175 const struct net_device *in,
176 const struct net_device *out,
177 int (*okfn)(struct sk_buff *))
179 struct sk_buff *reasm = skb->nfct_reasm;
180 const struct nf_conn_help *help;
182 enum ip_conntrack_info ctinfo;
184 /* This packet is fragmented and has reassembled packet. */
186 /* Reassembled packet isn't parsed yet ? */
190 ret = nf_conntrack_in(net, PF_INET6, hooknum, reasm);
191 if (ret != NF_ACCEPT)
195 /* Conntrack helpers need the entire reassembled packet in the
196 * POST_ROUTING hook. In case of unconfirmed connections NAT
197 * might reassign a helper, so the entire packet is also
200 ct = nf_ct_get(reasm, &ctinfo);
201 if (ct != NULL && !nf_ct_is_untracked(ct)) {
202 help = nfct_help(ct);
203 if ((help && help->helper) || !nf_ct_is_confirmed(ct)) {
204 nf_conntrack_get_reasm(reasm);
205 NF_HOOK_THRESH(NFPROTO_IPV6, hooknum, reasm,
206 (struct net_device *)in,
207 (struct net_device *)out,
208 okfn, NF_IP6_PRI_CONNTRACK + 1);
209 return NF_DROP_ERR(-ECANCELED);
213 nf_conntrack_get(reasm->nfct);
214 skb->nfct = reasm->nfct;
215 skb->nfctinfo = reasm->nfctinfo;
219 return nf_conntrack_in(net, PF_INET6, hooknum, skb);
222 static unsigned int ipv6_conntrack_in(const struct nf_hook_ops *ops,
224 const struct net_device *in,
225 const struct net_device *out,
226 int (*okfn)(struct sk_buff *))
228 return __ipv6_conntrack_in(dev_net(in), ops->hooknum, skb, in, out,
232 static unsigned int ipv6_conntrack_local(const struct nf_hook_ops *ops,
234 const struct net_device *in,
235 const struct net_device *out,
236 int (*okfn)(struct sk_buff *))
238 /* root is playing with raw sockets. */
239 if (skb->len < sizeof(struct ipv6hdr)) {
240 net_notice_ratelimited("ipv6_conntrack_local: packet too short\n");
243 return __ipv6_conntrack_in(dev_net(out), ops->hooknum, skb, in, out,
247 static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
249 .hook = ipv6_conntrack_in,
250 .owner = THIS_MODULE,
252 .hooknum = NF_INET_PRE_ROUTING,
253 .priority = NF_IP6_PRI_CONNTRACK,
256 .hook = ipv6_conntrack_local,
257 .owner = THIS_MODULE,
259 .hooknum = NF_INET_LOCAL_OUT,
260 .priority = NF_IP6_PRI_CONNTRACK,
264 .owner = THIS_MODULE,
266 .hooknum = NF_INET_POST_ROUTING,
267 .priority = NF_IP6_PRI_CONNTRACK_HELPER,
270 .hook = ipv6_confirm,
271 .owner = THIS_MODULE,
273 .hooknum = NF_INET_POST_ROUTING,
274 .priority = NF_IP6_PRI_LAST,
278 .owner = THIS_MODULE,
280 .hooknum = NF_INET_LOCAL_IN,
281 .priority = NF_IP6_PRI_CONNTRACK_HELPER,
284 .hook = ipv6_confirm,
285 .owner = THIS_MODULE,
287 .hooknum = NF_INET_LOCAL_IN,
288 .priority = NF_IP6_PRI_LAST-1,
293 ipv6_getorigdst(struct sock *sk, int optval, void __user *user, int *len)
295 const struct inet_sock *inet = inet_sk(sk);
296 const struct ipv6_pinfo *inet6 = inet6_sk(sk);
297 const struct nf_conntrack_tuple_hash *h;
298 struct sockaddr_in6 sin6;
299 struct nf_conntrack_tuple tuple = { .src.l3num = NFPROTO_IPV6 };
302 tuple.src.u3.in6 = sk->sk_v6_rcv_saddr;
303 tuple.src.u.tcp.port = inet->inet_sport;
304 tuple.dst.u3.in6 = sk->sk_v6_daddr;
305 tuple.dst.u.tcp.port = inet->inet_dport;
306 tuple.dst.protonum = sk->sk_protocol;
308 if (sk->sk_protocol != IPPROTO_TCP && sk->sk_protocol != IPPROTO_SCTP)
311 if (*len < 0 || (unsigned int) *len < sizeof(sin6))
314 h = nf_conntrack_find_get(sock_net(sk), NF_CT_DEFAULT_ZONE, &tuple);
316 pr_debug("IP6T_SO_ORIGINAL_DST: Can't find %pI6c/%u-%pI6c/%u.\n",
317 &tuple.src.u3.ip6, ntohs(tuple.src.u.tcp.port),
318 &tuple.dst.u3.ip6, ntohs(tuple.dst.u.tcp.port));
322 ct = nf_ct_tuplehash_to_ctrack(h);
324 sin6.sin6_family = AF_INET6;
325 sin6.sin6_port = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.tcp.port;
326 sin6.sin6_flowinfo = inet6->flow_label & IPV6_FLOWINFO_MASK;
327 memcpy(&sin6.sin6_addr,
328 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in6,
329 sizeof(sin6.sin6_addr));
332 sin6.sin6_scope_id = ipv6_iface_scope_id(&sin6.sin6_addr,
333 sk->sk_bound_dev_if);
334 return copy_to_user(user, &sin6, sizeof(sin6)) ? -EFAULT : 0;
337 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
339 #include <linux/netfilter/nfnetlink.h>
340 #include <linux/netfilter/nfnetlink_conntrack.h>
342 static int ipv6_tuple_to_nlattr(struct sk_buff *skb,
343 const struct nf_conntrack_tuple *tuple)
345 if (nla_put(skb, CTA_IP_V6_SRC, sizeof(u_int32_t) * 4,
346 &tuple->src.u3.ip6) ||
347 nla_put(skb, CTA_IP_V6_DST, sizeof(u_int32_t) * 4,
349 goto nla_put_failure;
356 static const struct nla_policy ipv6_nla_policy[CTA_IP_MAX+1] = {
357 [CTA_IP_V6_SRC] = { .len = sizeof(u_int32_t)*4 },
358 [CTA_IP_V6_DST] = { .len = sizeof(u_int32_t)*4 },
361 static int ipv6_nlattr_to_tuple(struct nlattr *tb[],
362 struct nf_conntrack_tuple *t)
364 if (!tb[CTA_IP_V6_SRC] || !tb[CTA_IP_V6_DST])
367 memcpy(&t->src.u3.ip6, nla_data(tb[CTA_IP_V6_SRC]),
368 sizeof(u_int32_t) * 4);
369 memcpy(&t->dst.u3.ip6, nla_data(tb[CTA_IP_V6_DST]),
370 sizeof(u_int32_t) * 4);
375 static int ipv6_nlattr_tuple_size(void)
377 return nla_policy_len(ipv6_nla_policy, CTA_IP_MAX + 1);
381 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 __read_mostly = {
384 .pkt_to_tuple = ipv6_pkt_to_tuple,
385 .invert_tuple = ipv6_invert_tuple,
386 .print_tuple = ipv6_print_tuple,
387 .get_l4proto = ipv6_get_l4proto,
388 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
389 .tuple_to_nlattr = ipv6_tuple_to_nlattr,
390 .nlattr_tuple_size = ipv6_nlattr_tuple_size,
391 .nlattr_to_tuple = ipv6_nlattr_to_tuple,
392 .nla_policy = ipv6_nla_policy,
397 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6));
398 MODULE_LICENSE("GPL");
399 MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>");
401 static struct nf_sockopt_ops so_getorigdst6 = {
403 .get_optmin = IP6T_SO_ORIGINAL_DST,
404 .get_optmax = IP6T_SO_ORIGINAL_DST + 1,
405 .get = ipv6_getorigdst,
406 .owner = THIS_MODULE,
409 static int ipv6_net_init(struct net *net)
413 ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_tcp6);
415 pr_err("nf_conntrack_tcp6: pernet registration failed\n");
418 ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_udp6);
420 pr_err("nf_conntrack_udp6: pernet registration failed\n");
423 ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_icmpv6);
425 pr_err("nf_conntrack_icmp6: pernet registration failed\n");
428 ret = nf_ct_l3proto_pernet_register(net, &nf_conntrack_l3proto_ipv6);
430 pr_err("nf_conntrack_ipv6: pernet registration failed.\n");
435 nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_icmpv6);
437 nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_udp6);
439 nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_tcp6);
444 static void ipv6_net_exit(struct net *net)
446 nf_ct_l3proto_pernet_unregister(net, &nf_conntrack_l3proto_ipv6);
447 nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_icmpv6);
448 nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_udp6);
449 nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_tcp6);
452 static struct pernet_operations ipv6_net_ops = {
453 .init = ipv6_net_init,
454 .exit = ipv6_net_exit,
457 static int __init nf_conntrack_l3proto_ipv6_init(void)
462 nf_defrag_ipv6_enable();
464 ret = nf_register_sockopt(&so_getorigdst6);
466 pr_err("Unable to register netfilter socket option\n");
470 ret = register_pernet_subsys(&ipv6_net_ops);
472 goto cleanup_sockopt;
474 ret = nf_register_hooks(ipv6_conntrack_ops,
475 ARRAY_SIZE(ipv6_conntrack_ops));
477 pr_err("nf_conntrack_ipv6: can't register pre-routing defrag "
482 ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_tcp6);
484 pr_err("nf_conntrack_ipv6: can't register tcp6 proto.\n");
488 ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_udp6);
490 pr_err("nf_conntrack_ipv6: can't register udp6 proto.\n");
494 ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_icmpv6);
496 pr_err("nf_conntrack_ipv6: can't register icmpv6 proto.\n");
500 ret = nf_ct_l3proto_register(&nf_conntrack_l3proto_ipv6);
502 pr_err("nf_conntrack_ipv6: can't register ipv6 proto.\n");
508 nf_ct_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
510 nf_ct_l4proto_unregister(&nf_conntrack_l4proto_udp6);
512 nf_ct_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
514 nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops));
516 unregister_pernet_subsys(&ipv6_net_ops);
518 nf_unregister_sockopt(&so_getorigdst6);
522 static void __exit nf_conntrack_l3proto_ipv6_fini(void)
525 nf_ct_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
526 nf_ct_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
527 nf_ct_l4proto_unregister(&nf_conntrack_l4proto_udp6);
528 nf_ct_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
529 nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops));
530 unregister_pernet_subsys(&ipv6_net_ops);
531 nf_unregister_sockopt(&so_getorigdst6);
534 module_init(nf_conntrack_l3proto_ipv6_init);
535 module_exit(nf_conntrack_l3proto_ipv6_fini);