x86/setup: Fix low identity map for >= 2GB kernel range
[linux-2.6/btrfs-unstable.git] / net / ipv6 / xfrm6_output.c
blobe15feb7b413dd1a93a376f2ab6aabcbc3c3bb944
1 /*
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>
18 #include <net/dst.h>
19 #include <net/ipv6.h>
20 #include <net/ip6_route.h>
21 #include <net/xfrm.h>
23 int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
24 u8 **prevhdr)
26 return ip6_find_1stfragopt(skb, prevhdr);
28 EXPORT_SYMBOL(xfrm6_find_1stfragopt);
30 static int xfrm6_local_dontfrag(struct sk_buff *skb)
32 int proto;
33 struct sock *sk = skb->sk;
35 if (sk) {
36 if (sk->sk_family != AF_INET6)
37 return 0;
39 proto = sk->sk_protocol;
40 if (proto == IPPROTO_UDP || proto == IPPROTO_RAW)
41 return inet6_sk(sk)->dontfrag;
44 return 0;
47 static void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
49 struct flowi6 fl6;
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)
60 struct flowi6 fl6;
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)
73 int mtu, ret = 0;
74 struct dst_entry *dst = skb_dst(skb);
76 mtu = dst_mtu(dst);
77 if (mtu < IPV6_MIN_MTU)
78 mtu = IPV6_MIN_MTU;
80 if (!skb->ignore_df && skb->len > mtu) {
81 skb->dev = dst->dev;
82 skb->protocol = htons(ETH_P_IPV6);
84 if (xfrm6_local_dontfrag(skb))
85 xfrm6_local_rxpmtu(skb, mtu);
86 else if (skb->sk)
87 xfrm_local_error(skb, mtu);
88 else
89 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
90 ret = -EMSGSIZE;
93 return ret;
96 int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
98 int err;
100 err = xfrm6_tunnel_check_size(skb);
101 if (err)
102 return err;
104 XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;
106 return xfrm6_extract_header(skb);
109 int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
111 int err;
113 err = xfrm_inner_extract_output(x, skb);
114 if (err)
115 return err;
117 skb->ignore_df = 1;
118 skb->protocol = htons(ETH_P_IPV6);
120 return x->outer_mode->output2(x, skb);
122 EXPORT_SYMBOL(xfrm6_prepare_output);
124 int xfrm6_output_finish(struct sock *sk, struct sk_buff *skb)
126 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
128 #ifdef CONFIG_NETFILTER
129 IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
130 #endif
132 return xfrm_output(sk, skb);
135 static int __xfrm6_output(struct sock *sk, struct sk_buff *skb)
137 struct dst_entry *dst = skb_dst(skb);
138 struct xfrm_state *x = dst->xfrm;
139 int mtu;
140 bool toobig;
142 #ifdef CONFIG_NETFILTER
143 if (!x) {
144 IP6CB(skb)->flags |= IP6SKB_REROUTED;
145 return dst_output_sk(sk, skb);
147 #endif
149 if (x->props.mode != XFRM_MODE_TUNNEL)
150 goto skip_frag;
152 if (skb->protocol == htons(ETH_P_IPV6))
153 mtu = ip6_skb_dst_mtu(skb);
154 else
155 mtu = dst_mtu(skb_dst(skb));
157 toobig = skb->len > mtu && !skb_is_gso(skb);
159 if (toobig && xfrm6_local_dontfrag(skb)) {
160 xfrm6_local_rxpmtu(skb, mtu);
161 return -EMSGSIZE;
162 } else if (!skb->ignore_df && toobig && skb->sk) {
163 xfrm_local_error(skb, mtu);
164 return -EMSGSIZE;
167 if (toobig || dst_allfrag(skb_dst(skb)))
168 return ip6_fragment(sk, skb,
169 x->outer_mode->afinfo->output_finish);
171 skip_frag:
172 return x->outer_mode->afinfo->output_finish(sk, skb);
175 int xfrm6_output(struct sock *sk, struct sk_buff *skb)
177 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, sk, skb,
178 NULL, skb_dst(skb)->dev, __xfrm6_output,
179 !(IP6CB(skb)->flags & IP6SKB_REROUTED));