]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * IP Payload Compression Protocol (IPComp) - RFC3173. | |
3 | * | |
4 | * Copyright (c) 2003 James Morris <jmorris@intercode.com.au> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the Free | |
e905a9ed | 8 | * Software Foundation; either version 2 of the License, or (at your option) |
1da177e4 LT |
9 | * any later version. |
10 | * | |
11 | * Todo: | |
12 | * - Tunable compression parameters. | |
13 | * - Compression stats. | |
14 | * - Adaptive compression. | |
15 | */ | |
1da177e4 | 16 | #include <linux/module.h> |
4999f362 | 17 | #include <linux/err.h> |
1da177e4 LT |
18 | #include <linux/rtnetlink.h> |
19 | #include <net/ip.h> | |
20 | #include <net/xfrm.h> | |
21 | #include <net/icmp.h> | |
22 | #include <net/ipcomp.h> | |
14c85021 | 23 | #include <net/protocol.h> |
6fccab67 | 24 | #include <net/sock.h> |
1da177e4 LT |
25 | |
26 | static void ipcomp4_err(struct sk_buff *skb, u32 info) | |
27 | { | |
a92df254 | 28 | struct net *net = dev_net(skb->dev); |
a94cfd19 | 29 | __be32 spi; |
1da177e4 LT |
30 | struct iphdr *iph = (struct iphdr *)skb->data; |
31 | struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2)); | |
32 | struct xfrm_state *x; | |
33 | ||
88c7664f ACM |
34 | if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH || |
35 | icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) | |
1da177e4 LT |
36 | return; |
37 | ||
4195f814 | 38 | spi = htonl(ntohs(ipch->cpi)); |
bd55775c | 39 | x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, |
e905a9ed | 40 | spi, IPPROTO_COMP, AF_INET); |
1da177e4 LT |
41 | if (!x) |
42 | return; | |
673d57e7 HH |
43 | NETDEBUG(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/%pI4\n", |
44 | spi, &iph->daddr); | |
1da177e4 LT |
45 | xfrm_state_put(x); |
46 | } | |
47 | ||
e905a9ed | 48 | /* We always hold one tunnel user reference to indicate a tunnel */ |
1da177e4 LT |
49 | static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x) |
50 | { | |
a92df254 | 51 | struct net *net = xs_net(x); |
1da177e4 | 52 | struct xfrm_state *t; |
e905a9ed | 53 | |
a92df254 | 54 | t = xfrm_state_alloc(net); |
1da177e4 LT |
55 | if (t == NULL) |
56 | goto out; | |
57 | ||
58 | t->id.proto = IPPROTO_IPIP; | |
59 | t->id.spi = x->props.saddr.a4; | |
60 | t->id.daddr.a4 = x->id.daddr.a4; | |
61 | memcpy(&t->sel, &x->sel, sizeof(t->sel)); | |
62 | t->props.family = AF_INET; | |
e40b3286 | 63 | t->props.mode = x->props.mode; |
1da177e4 LT |
64 | t->props.saddr.a4 = x->props.saddr.a4; |
65 | t->props.flags = x->props.flags; | |
bd55775c | 66 | memcpy(&t->mark, &x->mark, sizeof(t->mark)); |
72cb6962 HX |
67 | |
68 | if (xfrm_init_state(t)) | |
1da177e4 LT |
69 | goto error; |
70 | ||
1da177e4 LT |
71 | atomic_set(&t->tunnel_users, 1); |
72 | out: | |
73 | return t; | |
74 | ||
75 | error: | |
76 | t->km.state = XFRM_STATE_DEAD; | |
77 | xfrm_state_put(t); | |
78 | t = NULL; | |
79 | goto out; | |
80 | } | |
81 | ||
82 | /* | |
4a3e2f71 | 83 | * Must be protected by xfrm_cfg_mutex. State and tunnel user references are |
1da177e4 LT |
84 | * always incremented on success. |
85 | */ | |
86 | static int ipcomp_tunnel_attach(struct xfrm_state *x) | |
87 | { | |
a92df254 | 88 | struct net *net = xs_net(x); |
1da177e4 LT |
89 | int err = 0; |
90 | struct xfrm_state *t; | |
bd55775c | 91 | u32 mark = x->mark.v & x->mark.m; |
1da177e4 | 92 | |
bd55775c | 93 | t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr.a4, |
e905a9ed | 94 | x->props.saddr.a4, IPPROTO_IPIP, AF_INET); |
1da177e4 LT |
95 | if (!t) { |
96 | t = ipcomp_tunnel_create(x); | |
97 | if (!t) { | |
98 | err = -EINVAL; | |
99 | goto out; | |
100 | } | |
101 | xfrm_state_insert(t); | |
102 | xfrm_state_hold(t); | |
103 | } | |
104 | x->tunnel = t; | |
105 | atomic_inc(&t->tunnel_users); | |
106 | out: | |
107 | return err; | |
108 | } | |
109 | ||
6fccab67 | 110 | static int ipcomp4_init_state(struct xfrm_state *x) |
1da177e4 | 111 | { |
2c3abab7 | 112 | int err = -EINVAL; |
1da177e4 | 113 | |
e40b3286 HX |
114 | x->props.header_len = 0; |
115 | switch (x->props.mode) { | |
116 | case XFRM_MODE_TRANSPORT: | |
117 | break; | |
118 | case XFRM_MODE_TUNNEL: | |
119 | x->props.header_len += sizeof(struct iphdr); | |
120 | break; | |
121 | default: | |
122 | goto out; | |
123 | } | |
124 | ||
6fccab67 HX |
125 | err = ipcomp_init_state(x); |
126 | if (err) | |
1da177e4 LT |
127 | goto out; |
128 | ||
7e49e6de | 129 | if (x->props.mode == XFRM_MODE_TUNNEL) { |
1da177e4 LT |
130 | err = ipcomp_tunnel_attach(x); |
131 | if (err) | |
10e7454e | 132 | goto out; |
1da177e4 LT |
133 | } |
134 | ||
1da177e4 LT |
135 | err = 0; |
136 | out: | |
137 | return err; | |
1da177e4 LT |
138 | } |
139 | ||
533cb5b0 | 140 | static const struct xfrm_type ipcomp_type = { |
1da177e4 LT |
141 | .description = "IPCOMP4", |
142 | .owner = THIS_MODULE, | |
143 | .proto = IPPROTO_COMP, | |
6fccab67 | 144 | .init_state = ipcomp4_init_state, |
1da177e4 LT |
145 | .destructor = ipcomp_destroy, |
146 | .input = ipcomp_input, | |
147 | .output = ipcomp_output | |
148 | }; | |
149 | ||
32613090 | 150 | static const struct net_protocol ipcomp4_protocol = { |
1da177e4 LT |
151 | .handler = xfrm4_rcv, |
152 | .err_handler = ipcomp4_err, | |
153 | .no_policy = 1, | |
154 | }; | |
155 | ||
156 | static int __init ipcomp4_init(void) | |
157 | { | |
158 | if (xfrm_register_type(&ipcomp_type, AF_INET) < 0) { | |
159 | printk(KERN_INFO "ipcomp init: can't add xfrm type\n"); | |
160 | return -EAGAIN; | |
161 | } | |
162 | if (inet_add_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0) { | |
163 | printk(KERN_INFO "ipcomp init: can't add protocol\n"); | |
164 | xfrm_unregister_type(&ipcomp_type, AF_INET); | |
165 | return -EAGAIN; | |
166 | } | |
167 | return 0; | |
168 | } | |
169 | ||
170 | static void __exit ipcomp4_fini(void) | |
171 | { | |
172 | if (inet_del_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0) | |
173 | printk(KERN_INFO "ip ipcomp close: can't remove protocol\n"); | |
174 | if (xfrm_unregister_type(&ipcomp_type, AF_INET) < 0) | |
175 | printk(KERN_INFO "ip ipcomp close: can't remove xfrm type\n"); | |
176 | } | |
177 | ||
178 | module_init(ipcomp4_init); | |
179 | module_exit(ipcomp4_fini); | |
180 | ||
181 | MODULE_LICENSE("GPL"); | |
6fccab67 | 182 | MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp/IPv4) - RFC3173"); |
1da177e4 LT |
183 | MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>"); |
184 | ||
d3d6dd3a | 185 | MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP); |