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
);