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 int conntrack6_net_id;
38 static DEFINE_MUTEX(register_ipv6_hooks);
40 struct conntrack6_net {
44 static bool ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
45 struct nf_conntrack_tuple *tuple)
50 ap = skb_header_pointer(skb, nhoff + offsetof(struct ipv6hdr, saddr),
51 sizeof(_addrs), _addrs);
55 memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6));
56 memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6));
61 static bool ipv6_invert_tuple(struct nf_conntrack_tuple *tuple,
62 const struct nf_conntrack_tuple *orig)
64 memcpy(tuple->src.u3.ip6, orig->dst.u3.ip6, sizeof(tuple->src.u3.ip6));
65 memcpy(tuple->dst.u3.ip6, orig->src.u3.ip6, sizeof(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(void *priv,
100 const struct nf_hook_state *state)
103 const struct nf_conn_help *help;
104 const struct nf_conntrack_helper *helper;
105 enum ip_conntrack_info ctinfo;
110 /* This is where we call the helper: as the packet goes out. */
111 ct = nf_ct_get(skb, &ctinfo);
112 if (!ct || ctinfo == IP_CT_RELATED_REPLY)
115 help = nfct_help(ct);
118 /* rcu_read_lock()ed by nf_hook_thresh */
119 helper = rcu_dereference(help->helper);
123 nexthdr = ipv6_hdr(skb)->nexthdr;
124 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
126 if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
127 pr_debug("proto header not found\n");
131 return helper->help(skb, protoff, ct, ctinfo);
134 static unsigned int ipv6_confirm(void *priv,
136 const struct nf_hook_state *state)
139 enum ip_conntrack_info ctinfo;
140 unsigned char pnum = ipv6_hdr(skb)->nexthdr;
144 ct = nf_ct_get(skb, &ctinfo);
145 if (!ct || ctinfo == IP_CT_RELATED_REPLY)
148 protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum,
150 if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
151 pr_debug("proto header not found\n");
155 /* adjust seqs for loopback traffic only in outgoing direction */
156 if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
157 !nf_is_loopback_packet(skb)) {
158 if (!nf_ct_seq_adjust(skb, ct, ctinfo, protoff)) {
159 NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
164 /* We've seen it coming out the other side: confirm it */
165 return nf_conntrack_confirm(skb);
168 static unsigned int ipv6_conntrack_in(void *priv,
170 const struct nf_hook_state *state)
172 return nf_conntrack_in(state->net, PF_INET6, state->hook, skb);
175 static unsigned int ipv6_conntrack_local(void *priv,
177 const struct nf_hook_state *state)
179 /* root is playing with raw sockets. */
180 if (skb->len < sizeof(struct ipv6hdr)) {
181 net_notice_ratelimited("ipv6_conntrack_local: packet too short\n");
184 return nf_conntrack_in(state->net, PF_INET6, state->hook, skb);
187 static const struct nf_hook_ops ipv6_conntrack_ops[] = {
189 .hook = ipv6_conntrack_in,
191 .hooknum = NF_INET_PRE_ROUTING,
192 .priority = NF_IP6_PRI_CONNTRACK,
195 .hook = ipv6_conntrack_local,
197 .hooknum = NF_INET_LOCAL_OUT,
198 .priority = NF_IP6_PRI_CONNTRACK,
203 .hooknum = NF_INET_POST_ROUTING,
204 .priority = NF_IP6_PRI_CONNTRACK_HELPER,
207 .hook = ipv6_confirm,
209 .hooknum = NF_INET_POST_ROUTING,
210 .priority = NF_IP6_PRI_LAST,
215 .hooknum = NF_INET_LOCAL_IN,
216 .priority = NF_IP6_PRI_CONNTRACK_HELPER,
219 .hook = ipv6_confirm,
221 .hooknum = NF_INET_LOCAL_IN,
222 .priority = NF_IP6_PRI_LAST-1,
227 ipv6_getorigdst(struct sock *sk, int optval, void __user *user, int *len)
229 const struct inet_sock *inet = inet_sk(sk);
230 const struct ipv6_pinfo *inet6 = inet6_sk(sk);
231 const struct nf_conntrack_tuple_hash *h;
232 struct sockaddr_in6 sin6;
233 struct nf_conntrack_tuple tuple = { .src.l3num = NFPROTO_IPV6 };
236 tuple.src.u3.in6 = sk->sk_v6_rcv_saddr;
237 tuple.src.u.tcp.port = inet->inet_sport;
238 tuple.dst.u3.in6 = sk->sk_v6_daddr;
239 tuple.dst.u.tcp.port = inet->inet_dport;
240 tuple.dst.protonum = sk->sk_protocol;
242 if (sk->sk_protocol != IPPROTO_TCP && sk->sk_protocol != IPPROTO_SCTP)
245 if (*len < 0 || (unsigned int) *len < sizeof(sin6))
248 h = nf_conntrack_find_get(sock_net(sk), &nf_ct_zone_dflt, &tuple);
250 pr_debug("IP6T_SO_ORIGINAL_DST: Can't find %pI6c/%u-%pI6c/%u.\n",
251 &tuple.src.u3.ip6, ntohs(tuple.src.u.tcp.port),
252 &tuple.dst.u3.ip6, ntohs(tuple.dst.u.tcp.port));
256 ct = nf_ct_tuplehash_to_ctrack(h);
258 sin6.sin6_family = AF_INET6;
259 sin6.sin6_port = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.tcp.port;
260 sin6.sin6_flowinfo = inet6->flow_label & IPV6_FLOWINFO_MASK;
261 memcpy(&sin6.sin6_addr,
262 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in6,
263 sizeof(sin6.sin6_addr));
266 sin6.sin6_scope_id = ipv6_iface_scope_id(&sin6.sin6_addr,
267 sk->sk_bound_dev_if);
268 return copy_to_user(user, &sin6, sizeof(sin6)) ? -EFAULT : 0;
271 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
273 #include <linux/netfilter/nfnetlink.h>
274 #include <linux/netfilter/nfnetlink_conntrack.h>
276 static int ipv6_tuple_to_nlattr(struct sk_buff *skb,
277 const struct nf_conntrack_tuple *tuple)
279 if (nla_put_in6_addr(skb, CTA_IP_V6_SRC, &tuple->src.u3.in6) ||
280 nla_put_in6_addr(skb, CTA_IP_V6_DST, &tuple->dst.u3.in6))
281 goto nla_put_failure;
288 static const struct nla_policy ipv6_nla_policy[CTA_IP_MAX+1] = {
289 [CTA_IP_V6_SRC] = { .len = sizeof(u_int32_t)*4 },
290 [CTA_IP_V6_DST] = { .len = sizeof(u_int32_t)*4 },
293 static int ipv6_nlattr_to_tuple(struct nlattr *tb[],
294 struct nf_conntrack_tuple *t)
296 if (!tb[CTA_IP_V6_SRC] || !tb[CTA_IP_V6_DST])
299 t->src.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_SRC]);
300 t->dst.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_DST]);
306 static int ipv6_hooks_register(struct net *net)
308 struct conntrack6_net *cnet = net_generic(net, conntrack6_net_id);
311 mutex_lock(®ister_ipv6_hooks);
316 err = nf_defrag_ipv6_enable(net);
322 err = nf_register_net_hooks(net, ipv6_conntrack_ops,
323 ARRAY_SIZE(ipv6_conntrack_ops));
327 mutex_unlock(®ister_ipv6_hooks);
331 static void ipv6_hooks_unregister(struct net *net)
333 struct conntrack6_net *cnet = net_generic(net, conntrack6_net_id);
335 mutex_lock(®ister_ipv6_hooks);
336 if (cnet->users && (--cnet->users == 0))
337 nf_unregister_net_hooks(net, ipv6_conntrack_ops,
338 ARRAY_SIZE(ipv6_conntrack_ops));
339 mutex_unlock(®ister_ipv6_hooks);
342 const struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 = {
344 .pkt_to_tuple = ipv6_pkt_to_tuple,
345 .invert_tuple = ipv6_invert_tuple,
346 .get_l4proto = ipv6_get_l4proto,
347 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
348 .tuple_to_nlattr = ipv6_tuple_to_nlattr,
349 .nlattr_to_tuple = ipv6_nlattr_to_tuple,
350 .nla_policy = ipv6_nla_policy,
351 .nla_size = NLA_ALIGN(NLA_HDRLEN + sizeof(u32[4])) +
352 NLA_ALIGN(NLA_HDRLEN + sizeof(u32[4])),
354 .net_ns_get = ipv6_hooks_register,
355 .net_ns_put = ipv6_hooks_unregister,
359 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6));
360 MODULE_LICENSE("GPL");
361 MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>");
363 static struct nf_sockopt_ops so_getorigdst6 = {
365 .get_optmin = IP6T_SO_ORIGINAL_DST,
366 .get_optmax = IP6T_SO_ORIGINAL_DST + 1,
367 .get = ipv6_getorigdst,
368 .owner = THIS_MODULE,
371 static struct nf_conntrack_l4proto *builtin_l4proto6[] = {
372 &nf_conntrack_l4proto_tcp6,
373 &nf_conntrack_l4proto_udp6,
374 &nf_conntrack_l4proto_icmpv6,
375 #ifdef CONFIG_NF_CT_PROTO_DCCP
376 &nf_conntrack_l4proto_dccp6,
378 #ifdef CONFIG_NF_CT_PROTO_SCTP
379 &nf_conntrack_l4proto_sctp6,
381 #ifdef CONFIG_NF_CT_PROTO_UDPLITE
382 &nf_conntrack_l4proto_udplite6,
386 static int ipv6_net_init(struct net *net)
388 return nf_ct_l4proto_pernet_register(net, builtin_l4proto6,
389 ARRAY_SIZE(builtin_l4proto6));
392 static void ipv6_net_exit(struct net *net)
394 nf_ct_l4proto_pernet_unregister(net, builtin_l4proto6,
395 ARRAY_SIZE(builtin_l4proto6));
398 static struct pernet_operations ipv6_net_ops = {
399 .init = ipv6_net_init,
400 .exit = ipv6_net_exit,
401 .id = &conntrack6_net_id,
402 .size = sizeof(struct conntrack6_net),
405 static int __init nf_conntrack_l3proto_ipv6_init(void)
411 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
412 if (WARN_ON(nla_policy_len(ipv6_nla_policy, CTA_IP_MAX + 1) !=
413 nf_conntrack_l3proto_ipv6.nla_size))
417 ret = nf_register_sockopt(&so_getorigdst6);
419 pr_err("Unable to register netfilter socket option\n");
423 ret = register_pernet_subsys(&ipv6_net_ops);
425 goto cleanup_sockopt;
427 ret = nf_ct_l4proto_register(builtin_l4proto6,
428 ARRAY_SIZE(builtin_l4proto6));
432 ret = nf_ct_l3proto_register(&nf_conntrack_l3proto_ipv6);
434 pr_err("nf_conntrack_ipv6: can't register ipv6 proto.\n");
435 goto cleanup_l4proto;
439 nf_ct_l4proto_unregister(builtin_l4proto6,
440 ARRAY_SIZE(builtin_l4proto6));
442 unregister_pernet_subsys(&ipv6_net_ops);
444 nf_unregister_sockopt(&so_getorigdst6);
448 static void __exit nf_conntrack_l3proto_ipv6_fini(void)
451 nf_ct_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
452 nf_ct_l4proto_unregister(builtin_l4proto6,
453 ARRAY_SIZE(builtin_l4proto6));
454 unregister_pernet_subsys(&ipv6_net_ops);
455 nf_unregister_sockopt(&so_getorigdst6);
458 module_init(nf_conntrack_l3proto_ipv6_init);
459 module_exit(nf_conntrack_l3proto_ipv6_fini);