2 * xfrm6_output.c - Common IPsec encapsulation code for IPv6.
3 * Copyright (C) 2002 USAGI/WIDE Project
4 * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/if_ether.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/skbuff.h>
16 #include <linux/icmpv6.h>
17 #include <linux/netfilter_ipv6.h>
20 #include <net/ip6_route.h>
23 int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
26 return ip6_find_1stfragopt(skb, prevhdr);
28 EXPORT_SYMBOL(xfrm6_find_1stfragopt);
30 static int xfrm6_local_dontfrag(struct sk_buff *skb)
33 struct sock *sk = skb->sk;
36 if (sk->sk_family != AF_INET6)
39 proto = sk->sk_protocol;
40 if (proto == IPPROTO_UDP || proto == IPPROTO_RAW)
41 return inet6_sk(sk)->dontfrag;
47 static void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
50 struct sock *sk = skb->sk;
52 fl6.flowi6_oif = sk->sk_bound_dev_if;
53 fl6.daddr = ipv6_hdr(skb)->daddr;
55 ipv6_local_rxpmtu(sk, &fl6, mtu);
58 void xfrm6_local_error(struct sk_buff *skb, u32 mtu)
61 const struct ipv6hdr *hdr;
62 struct sock *sk = skb->sk;
64 hdr = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);
65 fl6.fl6_dport = inet_sk(sk)->inet_dport;
66 fl6.daddr = hdr->daddr;
68 ipv6_local_error(sk, EMSGSIZE, &fl6, mtu);
71 static int xfrm6_tunnel_check_size(struct sk_buff *skb)
74 struct dst_entry *dst = skb_dst(skb);
80 if (mtu < IPV6_MIN_MTU)
83 if ((!skb_is_gso(skb) && skb->len > mtu) ||
85 !skb_gso_validate_network_len(skb, ip6_skb_dst_mtu(skb)))) {
87 skb->protocol = htons(ETH_P_IPV6);
89 if (xfrm6_local_dontfrag(skb))
90 xfrm6_local_rxpmtu(skb, mtu);
92 xfrm_local_error(skb, mtu);
94 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
101 int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
105 err = xfrm6_tunnel_check_size(skb);
109 XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;
111 return xfrm6_extract_header(skb);
114 int xfrm6_output_finish(struct sock *sk, struct sk_buff *skb)
116 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
118 #ifdef CONFIG_NETFILTER
119 IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
122 return xfrm_output(sk, skb);
125 static int __xfrm6_output_state_finish(struct xfrm_state *x, struct sock *sk,
128 const struct xfrm_state_afinfo *afinfo;
129 int ret = -EAFNOSUPPORT;
132 afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family);
134 ret = afinfo->output_finish(sk, skb);
142 static int __xfrm6_output_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
144 struct xfrm_state *x = skb_dst(skb)->xfrm;
146 return __xfrm6_output_state_finish(x, sk, skb);
149 static int __xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
151 struct dst_entry *dst = skb_dst(skb);
152 struct xfrm_state *x = dst->xfrm;
156 #ifdef CONFIG_NETFILTER
158 IP6CB(skb)->flags |= IP6SKB_REROUTED;
159 return dst_output(net, sk, skb);
163 if (x->props.mode != XFRM_MODE_TUNNEL)
166 if (skb->protocol == htons(ETH_P_IPV6))
167 mtu = ip6_skb_dst_mtu(skb);
169 mtu = dst_mtu(skb_dst(skb));
171 toobig = skb->len > mtu && !skb_is_gso(skb);
173 if (toobig && xfrm6_local_dontfrag(skb)) {
174 xfrm6_local_rxpmtu(skb, mtu);
177 } else if (!skb->ignore_df && toobig && skb->sk) {
178 xfrm_local_error(skb, mtu);
183 if (toobig || dst_allfrag(skb_dst(skb)))
184 return ip6_fragment(net, sk, skb,
185 __xfrm6_output_finish);
188 return __xfrm6_output_state_finish(x, sk, skb);
191 int xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
193 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
194 net, sk, skb, NULL, skb_dst(skb)->dev,
196 !(IP6CB(skb)->flags & IP6SKB_REROUTED));