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[linux/fpc-iii.git] / net / ipv6 / ipcomp6.c
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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, see <http://www.gnu.org/licenses/>.
22 * [Memo]
24 * Outbound:
25 * The compression of IP datagram MUST be done before AH/ESP processing,
26 * fragmentation, and the addition of Hop-by-Hop/Routing header.
28 * Inbound:
29 * The decompression of IP datagram MUST be done after the reassembly,
30 * AH/ESP processing.
33 #define pr_fmt(fmt) "IPv6: " fmt
35 #include <linux/module.h>
36 #include <net/ip.h>
37 #include <net/xfrm.h>
38 #include <net/ipcomp.h>
39 #include <linux/crypto.h>
40 #include <linux/err.h>
41 #include <linux/pfkeyv2.h>
42 #include <linux/random.h>
43 #include <linux/percpu.h>
44 #include <linux/smp.h>
45 #include <linux/list.h>
46 #include <linux/vmalloc.h>
47 #include <linux/rtnetlink.h>
48 #include <net/ip6_route.h>
49 #include <net/icmp.h>
50 #include <net/ipv6.h>
51 #include <net/protocol.h>
52 #include <linux/ipv6.h>
53 #include <linux/icmpv6.h>
54 #include <linux/mutex.h>
56 static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
57 u8 type, u8 code, int offset, __be32 info)
59 struct net *net = dev_net(skb->dev);
60 __be32 spi;
61 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
62 struct ip_comp_hdr *ipcomph =
63 (struct ip_comp_hdr *)(skb->data + offset);
64 struct xfrm_state *x;
66 if (type != ICMPV6_PKT_TOOBIG &&
67 type != NDISC_REDIRECT)
68 return;
70 spi = htonl(ntohs(ipcomph->cpi));
71 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
72 spi, IPPROTO_COMP, AF_INET6);
73 if (!x)
74 return;
76 if (type == NDISC_REDIRECT)
77 ip6_redirect(skb, net, skb->dev->ifindex, 0);
78 else
79 ip6_update_pmtu(skb, net, info, 0, 0);
80 xfrm_state_put(x);
83 static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x)
85 struct net *net = xs_net(x);
86 struct xfrm_state *t = NULL;
88 t = xfrm_state_alloc(net);
89 if (!t)
90 goto out;
92 t->id.proto = IPPROTO_IPV6;
93 t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr);
94 if (!t->id.spi)
95 goto error;
97 memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
98 memcpy(&t->sel, &x->sel, sizeof(t->sel));
99 t->props.family = AF_INET6;
100 t->props.mode = x->props.mode;
101 memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
102 memcpy(&t->mark, &x->mark, sizeof(t->mark));
104 if (xfrm_init_state(t))
105 goto error;
107 atomic_set(&t->tunnel_users, 1);
109 out:
110 return t;
112 error:
113 t->km.state = XFRM_STATE_DEAD;
114 xfrm_state_put(t);
115 t = NULL;
116 goto out;
119 static int ipcomp6_tunnel_attach(struct xfrm_state *x)
121 struct net *net = xs_net(x);
122 int err = 0;
123 struct xfrm_state *t = NULL;
124 __be32 spi;
125 u32 mark = x->mark.m & x->mark.v;
127 spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr);
128 if (spi)
129 t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr,
130 spi, IPPROTO_IPV6, AF_INET6);
131 if (!t) {
132 t = ipcomp6_tunnel_create(x);
133 if (!t) {
134 err = -EINVAL;
135 goto out;
137 xfrm_state_insert(t);
138 xfrm_state_hold(t);
140 x->tunnel = t;
141 atomic_inc(&t->tunnel_users);
143 out:
144 return err;
147 static int ipcomp6_init_state(struct xfrm_state *x)
149 int err = -EINVAL;
151 x->props.header_len = 0;
152 switch (x->props.mode) {
153 case XFRM_MODE_TRANSPORT:
154 break;
155 case XFRM_MODE_TUNNEL:
156 x->props.header_len += sizeof(struct ipv6hdr);
157 break;
158 default:
159 goto out;
162 err = ipcomp_init_state(x);
163 if (err)
164 goto out;
166 if (x->props.mode == XFRM_MODE_TUNNEL) {
167 err = ipcomp6_tunnel_attach(x);
168 if (err)
169 goto out;
172 err = 0;
173 out:
174 return err;
177 static const struct xfrm_type ipcomp6_type =
179 .description = "IPCOMP6",
180 .owner = THIS_MODULE,
181 .proto = IPPROTO_COMP,
182 .init_state = ipcomp6_init_state,
183 .destructor = ipcomp_destroy,
184 .input = ipcomp_input,
185 .output = ipcomp_output,
186 .hdr_offset = xfrm6_find_1stfragopt,
189 static const struct inet6_protocol ipcomp6_protocol =
191 .handler = xfrm6_rcv,
192 .err_handler = ipcomp6_err,
193 .flags = INET6_PROTO_NOPOLICY,
196 static int __init ipcomp6_init(void)
198 if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
199 pr_info("%s: can't add xfrm type\n", __func__);
200 return -EAGAIN;
202 if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
203 pr_info("%s: can't add protocol\n", __func__);
204 xfrm_unregister_type(&ipcomp6_type, AF_INET6);
205 return -EAGAIN;
207 return 0;
210 static void __exit ipcomp6_fini(void)
212 if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
213 pr_info("%s: can't remove protocol\n", __func__);
214 if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
215 pr_info("%s: can't remove xfrm type\n", __func__);
218 module_init(ipcomp6_init);
219 module_exit(ipcomp6_fini);
220 MODULE_LICENSE("GPL");
221 MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
222 MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
224 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);