2 * IP Payload Compression Protocol (IPComp) - RFC3173.
4 * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
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
8 * Software Foundation; either version 2 of the License, or (at your option)
12 * - Tunable compression parameters.
13 * - Compression stats.
14 * - Adaptive compression.
16 #include <linux/module.h>
17 #include <linux/err.h>
18 #include <linux/rtnetlink.h>
22 #include <net/ipcomp.h>
23 #include <net/protocol.h>
26 static void ipcomp4_err(struct sk_buff *skb, u32 info)
28 struct net *net = dev_net(skb->dev);
30 struct iphdr *iph = (struct iphdr *)skb->data;
31 struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
34 if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
35 icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
38 spi = htonl(ntohs(ipch->cpi));
39 x = xfrm_state_lookup(net, (xfrm_address_t *)&iph->daddr,
40 spi, IPPROTO_COMP, AF_INET);
43 NETDEBUG(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/%pI4\n",
48 /* We always hold one tunnel user reference to indicate a tunnel */
49 static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x)
51 struct net *net = xs_net(x);
54 t = xfrm_state_alloc(net);
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;
63 t->props.mode = x->props.mode;
64 t->props.saddr.a4 = x->props.saddr.a4;
65 t->props.flags = x->props.flags;
67 if (xfrm_init_state(t))
70 atomic_set(&t->tunnel_users, 1);
75 t->km.state = XFRM_STATE_DEAD;
82 * Must be protected by xfrm_cfg_mutex. State and tunnel user references are
83 * always incremented on success.
85 static int ipcomp_tunnel_attach(struct xfrm_state *x)
87 struct net *net = xs_net(x);
91 t = xfrm_state_lookup(net, (xfrm_address_t *)&x->id.daddr.a4,
92 x->props.saddr.a4, IPPROTO_IPIP, AF_INET);
94 t = ipcomp_tunnel_create(x);
103 atomic_inc(&t->tunnel_users);
108 static int ipcomp4_init_state(struct xfrm_state *x)
112 x->props.header_len = 0;
113 switch (x->props.mode) {
114 case XFRM_MODE_TRANSPORT:
116 case XFRM_MODE_TUNNEL:
117 x->props.header_len += sizeof(struct iphdr);
123 err = ipcomp_init_state(x);
127 if (x->props.mode == XFRM_MODE_TUNNEL) {
128 err = ipcomp_tunnel_attach(x);
142 static const struct xfrm_type ipcomp_type = {
143 .description = "IPCOMP4",
144 .owner = THIS_MODULE,
145 .proto = IPPROTO_COMP,
146 .init_state = ipcomp4_init_state,
147 .destructor = ipcomp_destroy,
148 .input = ipcomp_input,
149 .output = ipcomp_output
152 static const struct net_protocol ipcomp4_protocol = {
153 .handler = xfrm4_rcv,
154 .err_handler = ipcomp4_err,
158 static int __init ipcomp4_init(void)
160 if (xfrm_register_type(&ipcomp_type, AF_INET) < 0) {
161 printk(KERN_INFO "ipcomp init: can't add xfrm type\n");
164 if (inet_add_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0) {
165 printk(KERN_INFO "ipcomp init: can't add protocol\n");
166 xfrm_unregister_type(&ipcomp_type, AF_INET);
172 static void __exit ipcomp4_fini(void)
174 if (inet_del_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0)
175 printk(KERN_INFO "ip ipcomp close: can't remove protocol\n");
176 if (xfrm_unregister_type(&ipcomp_type, AF_INET) < 0)
177 printk(KERN_INFO "ip ipcomp close: can't remove xfrm type\n");
180 module_init(ipcomp4_init);
181 module_exit(ipcomp4_fini);
183 MODULE_LICENSE("GPL");
184 MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp/IPv4) - RFC3173");
185 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
187 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP);