Linux 3.8-rc7
[cris-mirror.git] / net / ipv6 / ipcomp6.c
blob7af5aee75d982327e7b258f72091780e83a01cc4
1 /*
2 * IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173
4 * Copyright (C)2003 USAGI/WIDE Project
6 * Author Mitsuru KANDA <mk@linux-ipv6.org>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 * [Memo]
25 * Outbound:
26 * The compression of IP datagram MUST be done before AH/ESP processing,
27 * fragmentation, and the addition of Hop-by-Hop/Routing header.
29 * Inbound:
30 * The decompression of IP datagram MUST be done after the reassembly,
31 * AH/ESP processing.
34 #define pr_fmt(fmt) "IPv6: " fmt
36 #include <linux/module.h>
37 #include <net/ip.h>
38 #include <net/xfrm.h>
39 #include <net/ipcomp.h>
40 #include <linux/crypto.h>
41 #include <linux/err.h>
42 #include <linux/pfkeyv2.h>
43 #include <linux/random.h>
44 #include <linux/percpu.h>
45 #include <linux/smp.h>
46 #include <linux/list.h>
47 #include <linux/vmalloc.h>
48 #include <linux/rtnetlink.h>
49 #include <net/ip6_route.h>
50 #include <net/icmp.h>
51 #include <net/ipv6.h>
52 #include <net/protocol.h>
53 #include <linux/ipv6.h>
54 #include <linux/icmpv6.h>
55 #include <linux/mutex.h>
57 static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
58 u8 type, u8 code, int offset, __be32 info)
60 struct net *net = dev_net(skb->dev);
61 __be32 spi;
62 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
63 struct ip_comp_hdr *ipcomph =
64 (struct ip_comp_hdr *)(skb->data + offset);
65 struct xfrm_state *x;
67 if (type != ICMPV6_DEST_UNREACH &&
68 type != ICMPV6_PKT_TOOBIG &&
69 type != NDISC_REDIRECT)
70 return;
72 spi = htonl(ntohs(ipcomph->cpi));
73 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
74 spi, IPPROTO_COMP, AF_INET6);
75 if (!x)
76 return;
78 if (type == NDISC_REDIRECT)
79 ip6_redirect(skb, net, 0, 0);
80 else
81 ip6_update_pmtu(skb, net, info, 0, 0);
82 xfrm_state_put(x);
85 static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x)
87 struct net *net = xs_net(x);
88 struct xfrm_state *t = NULL;
90 t = xfrm_state_alloc(net);
91 if (!t)
92 goto out;
94 t->id.proto = IPPROTO_IPV6;
95 t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr);
96 if (!t->id.spi)
97 goto error;
99 memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
100 memcpy(&t->sel, &x->sel, sizeof(t->sel));
101 t->props.family = AF_INET6;
102 t->props.mode = x->props.mode;
103 memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
104 memcpy(&t->mark, &x->mark, sizeof(t->mark));
106 if (xfrm_init_state(t))
107 goto error;
109 atomic_set(&t->tunnel_users, 1);
111 out:
112 return t;
114 error:
115 t->km.state = XFRM_STATE_DEAD;
116 xfrm_state_put(t);
117 t = NULL;
118 goto out;
121 static int ipcomp6_tunnel_attach(struct xfrm_state *x)
123 struct net *net = xs_net(x);
124 int err = 0;
125 struct xfrm_state *t = NULL;
126 __be32 spi;
127 u32 mark = x->mark.m & x->mark.v;
129 spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr);
130 if (spi)
131 t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr,
132 spi, IPPROTO_IPV6, AF_INET6);
133 if (!t) {
134 t = ipcomp6_tunnel_create(x);
135 if (!t) {
136 err = -EINVAL;
137 goto out;
139 xfrm_state_insert(t);
140 xfrm_state_hold(t);
142 x->tunnel = t;
143 atomic_inc(&t->tunnel_users);
145 out:
146 return err;
149 static int ipcomp6_init_state(struct xfrm_state *x)
151 int err = -EINVAL;
153 x->props.header_len = 0;
154 switch (x->props.mode) {
155 case XFRM_MODE_TRANSPORT:
156 break;
157 case XFRM_MODE_TUNNEL:
158 x->props.header_len += sizeof(struct ipv6hdr);
159 break;
160 default:
161 goto out;
164 err = ipcomp_init_state(x);
165 if (err)
166 goto out;
168 if (x->props.mode == XFRM_MODE_TUNNEL) {
169 err = ipcomp6_tunnel_attach(x);
170 if (err)
171 goto out;
174 err = 0;
175 out:
176 return err;
179 static const struct xfrm_type ipcomp6_type =
181 .description = "IPCOMP6",
182 .owner = THIS_MODULE,
183 .proto = IPPROTO_COMP,
184 .init_state = ipcomp6_init_state,
185 .destructor = ipcomp_destroy,
186 .input = ipcomp_input,
187 .output = ipcomp_output,
188 .hdr_offset = xfrm6_find_1stfragopt,
191 static const struct inet6_protocol ipcomp6_protocol =
193 .handler = xfrm6_rcv,
194 .err_handler = ipcomp6_err,
195 .flags = INET6_PROTO_NOPOLICY,
198 static int __init ipcomp6_init(void)
200 if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
201 pr_info("%s: can't add xfrm type\n", __func__);
202 return -EAGAIN;
204 if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
205 pr_info("%s: can't add protocol\n", __func__);
206 xfrm_unregister_type(&ipcomp6_type, AF_INET6);
207 return -EAGAIN;
209 return 0;
212 static void __exit ipcomp6_fini(void)
214 if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
215 pr_info("%s: can't remove protocol\n", __func__);
216 if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
217 pr_info("%s: can't remove xfrm type\n", __func__);
220 module_init(ipcomp6_init);
221 module_exit(ipcomp6_fini);
222 MODULE_LICENSE("GPL");
223 MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
224 MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
226 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);