tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
5 *
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.
10 */
11
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>
22
23int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
24 u8 **prevhdr)
25{
26 return ip6_find_1stfragopt(skb, prevhdr);
27}
28
29EXPORT_SYMBOL(xfrm6_find_1stfragopt);
30
31static int xfrm6_local_dontfrag(struct sk_buff *skb)
32{
33 int proto;
34 struct sock *sk = skb->sk;
35
36 if (sk) {
37 if (sk->sk_family != AF_INET6)
38 return 0;
39
40 proto = sk->sk_protocol;
41 if (proto == IPPROTO_UDP || proto == IPPROTO_RAW)
42 return inet6_sk(sk)->dontfrag;
43 }
44
45 return 0;
46}
47
48static void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
49{
50 struct flowi6 fl6;
51 struct sock *sk = skb->sk;
52
53 fl6.flowi6_oif = sk->sk_bound_dev_if;
54 fl6.daddr = ipv6_hdr(skb)->daddr;
55
56 ipv6_local_rxpmtu(sk, &fl6, mtu);
57}
58
59void xfrm6_local_error(struct sk_buff *skb, u32 mtu)
60{
61 struct flowi6 fl6;
62 const struct ipv6hdr *hdr;
63 struct sock *sk = skb->sk;
64
65 hdr = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);
66 fl6.fl6_dport = inet_sk(sk)->inet_dport;
67 fl6.daddr = hdr->daddr;
68
69 ipv6_local_error(sk, EMSGSIZE, &fl6, mtu);
70}
71
72static int xfrm6_tunnel_check_size(struct sk_buff *skb)
73{
74 int mtu, ret = 0;
75 struct dst_entry *dst = skb_dst(skb);
76
77 mtu = dst_mtu(dst);
78 if (mtu < IPV6_MIN_MTU)
79 mtu = IPV6_MIN_MTU;
80
81 if (!skb->local_df && skb->len > mtu) {
82 skb->dev = dst->dev;
83
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;
91 }
92
93 return ret;
94}
95
96int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
97{
98 int err;
99
100 err = xfrm6_tunnel_check_size(skb);
101 if (err)
102 return err;
103
104 XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;
105
106 return xfrm6_extract_header(skb);
107}
108
109int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
110{
111 int err;
112
113 err = xfrm_inner_extract_output(x, skb);
114 if (err)
115 return err;
116
117 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
118#ifdef CONFIG_NETFILTER
119 IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
120#endif
121
122 skb->protocol = htons(ETH_P_IPV6);
123 skb->local_df = 1;
124
125 return x->outer_mode->output2(x, skb);
126}
127EXPORT_SYMBOL(xfrm6_prepare_output);
128
129int xfrm6_output_finish(struct sk_buff *skb)
130{
131#ifdef CONFIG_NETFILTER
132 IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
133#endif
134
135 skb->protocol = htons(ETH_P_IPV6);
136 return xfrm_output(skb);
137}
138
139static int __xfrm6_output(struct sk_buff *skb)
140{
141 struct dst_entry *dst = skb_dst(skb);
142 struct xfrm_state *x = dst->xfrm;
143 int mtu;
144
145 if (skb->protocol == htons(ETH_P_IPV6))
146 mtu = ip6_skb_dst_mtu(skb);
147 else
148 mtu = dst_mtu(skb_dst(skb));
149
150 if (skb->len > mtu && xfrm6_local_dontfrag(skb)) {
151 xfrm6_local_rxpmtu(skb, mtu);
152 return -EMSGSIZE;
153 } else if (!skb->local_df && skb->len > mtu && skb->sk) {
154 xfrm_local_error(skb, mtu);
155 return -EMSGSIZE;
156 }
157
158 if (x->props.mode == XFRM_MODE_TUNNEL &&
159 ((skb->len > mtu && !skb_is_gso(skb)) ||
160 dst_allfrag(skb_dst(skb)))) {
161 return ip6_fragment(skb, x->outer_mode->afinfo->output_finish);
162 }
163 return x->outer_mode->afinfo->output_finish(skb);
164}
165
166int xfrm6_output(struct sk_buff *skb)
167{
168 return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL,
169 skb_dst(skb)->dev, __xfrm6_output);
170}