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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173
3 *
4 * Copyright (C)2003 USAGI/WIDE Project
5 *
6 * Author Mitsuru KANDA <mk@linux-ipv6.org>
7 *
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.
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090012 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * 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.
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090017 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 * 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
21 */
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090022/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070023 * [Memo]
24 *
25 * Outbound:
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090026 * The compression of IP datagram MUST be done before AH/ESP processing,
27 * fragmentation, and the addition of Hop-by-Hop/Routing header.
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 *
29 * Inbound:
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090030 * The decompression of IP datagram MUST be done after the reassembly,
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 * AH/ESP processing.
32 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/module.h>
34#include <net/ip.h>
35#include <net/xfrm.h>
36#include <net/ipcomp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <linux/crypto.h>
Herbert Xu4999f362007-11-07 02:21:47 -080038#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#include <linux/pfkeyv2.h>
40#include <linux/random.h>
41#include <linux/percpu.h>
42#include <linux/smp.h>
43#include <linux/list.h>
44#include <linux/vmalloc.h>
45#include <linux/rtnetlink.h>
46#include <net/icmp.h>
47#include <net/ipv6.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020048#include <net/protocol.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#include <linux/ipv6.h>
50#include <linux/icmpv6.h>
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -080051#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
Linus Torvalds1da177e2005-04-16 15:20:36 -070053static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090054 int type, int code, int offset, __be32 info)
Linus Torvalds1da177e2005-04-16 15:20:36 -070055{
Al Viroa94cfd12006-09-27 18:47:24 -070056 __be32 spi;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
Herbert Xu87bdc482007-10-10 15:45:25 -070058 struct ip_comp_hdr *ipcomph =
59 (struct ip_comp_hdr *)(skb->data + offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 struct xfrm_state *x;
61
62 if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
63 return;
64
Alexey Dobriyan4195f812006-05-22 16:53:22 -070065 spi = htonl(ntohs(ipcomph->cpi));
Alexey Dobriyan221df1e2008-11-25 17:30:50 -080066 x = xfrm_state_lookup(&init_net, (xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6);
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 if (!x)
68 return;
69
Harvey Harrison5b095d9892008-10-29 12:52:50 -070070 printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/%pI6\n",
Harvey Harrison0c6ce782008-10-28 16:09:23 -070071 spi, &iph->daddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 xfrm_state_put(x);
73}
74
75static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x)
76{
77 struct xfrm_state *t = NULL;
78
Alexey Dobriyan673c09b2008-11-25 17:15:16 -080079 t = xfrm_state_alloc(&init_net);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 if (!t)
81 goto out;
82
83 t->id.proto = IPPROTO_IPV6;
84 t->id.spi = xfrm6_tunnel_alloc_spi((xfrm_address_t *)&x->props.saddr);
Herbert Xu6abaaaa2006-03-26 17:37:54 -080085 if (!t->id.spi)
86 goto error;
87
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
89 memcpy(&t->sel, &x->sel, sizeof(t->sel));
90 t->props.family = AF_INET6;
Herbert Xue40b3282007-11-13 21:39:08 -080091 t->props.mode = x->props.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
93
Herbert Xu72cb6962005-06-20 13:18:08 -070094 if (xfrm_init_state(t))
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 goto error;
96
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 atomic_set(&t->tunnel_users, 1);
98
99out:
100 return t;
101
102error:
Herbert Xu6abaaaa2006-03-26 17:37:54 -0800103 t->km.state = XFRM_STATE_DEAD;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 xfrm_state_put(t);
Herbert Xu6abaaaa2006-03-26 17:37:54 -0800105 t = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 goto out;
107}
108
109static int ipcomp6_tunnel_attach(struct xfrm_state *x)
110{
111 int err = 0;
112 struct xfrm_state *t = NULL;
Al Viroa94cfd12006-09-27 18:47:24 -0700113 __be32 spi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
115 spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr);
116 if (spi)
Alexey Dobriyan221df1e2008-11-25 17:30:50 -0800117 t = xfrm_state_lookup(&init_net, (xfrm_address_t *)&x->id.daddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 spi, IPPROTO_IPV6, AF_INET6);
119 if (!t) {
120 t = ipcomp6_tunnel_create(x);
121 if (!t) {
122 err = -EINVAL;
123 goto out;
124 }
125 xfrm_state_insert(t);
126 xfrm_state_hold(t);
127 }
128 x->tunnel = t;
129 atomic_inc(&t->tunnel_users);
130
131out:
132 return err;
133}
134
Herbert Xu72cb6962005-06-20 13:18:08 -0700135static int ipcomp6_init_state(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136{
David S. Miller2c3abab2008-07-27 03:59:24 -0700137 int err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 x->props.header_len = 0;
Herbert Xuca681452007-10-17 21:35:15 -0700140 switch (x->props.mode) {
Herbert Xuca681452007-10-17 21:35:15 -0700141 case XFRM_MODE_TRANSPORT:
142 break;
143 case XFRM_MODE_TUNNEL:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 x->props.header_len += sizeof(struct ipv6hdr);
Herbert Xue40b3282007-11-13 21:39:08 -0800145 break;
Herbert Xuca681452007-10-17 21:35:15 -0700146 default:
Herbert Xue40b3282007-11-13 21:39:08 -0800147 goto out;
Herbert Xuca681452007-10-17 21:35:15 -0700148 }
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900149
Herbert Xu6fccab62008-07-25 02:54:40 -0700150 err = ipcomp_init_state(x);
151 if (err)
Herbert Xue40b3282007-11-13 21:39:08 -0800152 goto out;
153
Masahide NAKAMURA7e49e6d2006-09-22 15:05:15 -0700154 if (x->props.mode == XFRM_MODE_TUNNEL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 err = ipcomp6_tunnel_attach(x);
156 if (err)
157 goto error_tunnel;
158 }
159
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 err = 0;
161out:
162 return err;
163error_tunnel:
Herbert Xu6fccab62008-07-25 02:54:40 -0700164 ipcomp_destroy(x);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
166 goto out;
167}
168
Eric Dumazet533cb5b2008-01-30 19:11:50 -0800169static const struct xfrm_type ipcomp6_type =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170{
171 .description = "IPCOMP6",
172 .owner = THIS_MODULE,
173 .proto = IPPROTO_COMP,
174 .init_state = ipcomp6_init_state,
Herbert Xu6fccab62008-07-25 02:54:40 -0700175 .destructor = ipcomp_destroy,
176 .input = ipcomp_input,
177 .output = ipcomp_output,
Masahide NAKAMURAaee5adb2006-08-23 17:57:28 -0700178 .hdr_offset = xfrm6_find_1stfragopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179};
180
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900181static struct inet6_protocol ipcomp6_protocol =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182{
183 .handler = xfrm6_rcv,
184 .err_handler = ipcomp6_err,
185 .flags = INET6_PROTO_NOPOLICY,
186};
187
188static int __init ipcomp6_init(void)
189{
190 if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
191 printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n");
192 return -EAGAIN;
193 }
194 if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
195 printk(KERN_INFO "ipcomp6 init: can't add protocol\n");
196 xfrm_unregister_type(&ipcomp6_type, AF_INET6);
197 return -EAGAIN;
198 }
199 return 0;
200}
201
202static void __exit ipcomp6_fini(void)
203{
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900204 if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n");
206 if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
207 printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n");
208}
209
210module_init(ipcomp6_init);
211module_exit(ipcomp6_fini);
212MODULE_LICENSE("GPL");
213MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
214MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
215
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700216MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);