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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09008 * Software Foundation; either version 2 of the License, or (at your option)
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 * any later version.
10 *
11 * Todo:
12 * - Tunable compression parameters.
13 * - Compression stats.
14 * - Adaptive compression.
15 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/module.h>
Herbert Xu4999f362007-11-07 02:21:47 -080017#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/rtnetlink.h>
19#include <net/ip.h>
20#include <net/xfrm.h>
21#include <net/icmp.h>
22#include <net/ipcomp.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020023#include <net/protocol.h>
Herbert Xu6fccab62008-07-25 02:54:40 -070024#include <net/sock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
Steffen Klassertd0991602014-02-21 08:41:09 +010026static int ipcomp4_err(struct sk_buff *skb, u32 info)
Linus Torvalds1da177e2005-04-16 15:20:36 -070027{
Alexey Dobriyana92df252010-01-25 10:38:34 +000028 struct net *net = dev_net(skb->dev);
Al Viroa94cfd12006-09-27 18:47:24 -070029 __be32 spi;
Eric Dumazetb71d1d42011-04-22 04:53:02 +000030 const struct iphdr *iph = (const struct iphdr *)skb->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
32 struct xfrm_state *x;
33
David S. Miller55be7a92012-07-11 21:27:49 -070034 switch (icmp_hdr(skb)->type) {
35 case ICMP_DEST_UNREACH:
36 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
Steffen Klassertd0991602014-02-21 08:41:09 +010037 return 0;
David S. Miller55be7a92012-07-11 21:27:49 -070038 case ICMP_REDIRECT:
39 break;
40 default:
Steffen Klassertd0991602014-02-21 08:41:09 +010041 return 0;
David S. Miller55be7a92012-07-11 21:27:49 -070042 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070043
Alexey Dobriyan4195f812006-05-22 16:53:22 -070044 spi = htonl(ntohs(ipch->cpi));
Eric Dumazetb71d1d42011-04-22 04:53:02 +000045 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090046 spi, IPPROTO_COMP, AF_INET);
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 if (!x)
Steffen Klassertd0991602014-02-21 08:41:09 +010048 return 0;
David S. Miller55be7a92012-07-11 21:27:49 -070049
Timo Teräs387aa652013-05-27 20:46:31 +000050 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
David S. Miller55be7a92012-07-11 21:27:49 -070051 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_COMP, 0);
Timo Teräs387aa652013-05-27 20:46:31 +000052 else
David S. Miller55be7a92012-07-11 21:27:49 -070053 ipv4_redirect(skb, net, 0, 0, IPPROTO_COMP, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 xfrm_state_put(x);
Steffen Klassertd0991602014-02-21 08:41:09 +010055
56 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057}
58
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090059/* We always hold one tunnel user reference to indicate a tunnel */
Linus Torvalds1da177e2005-04-16 15:20:36 -070060static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x)
61{
Alexey Dobriyana92df252010-01-25 10:38:34 +000062 struct net *net = xs_net(x);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 struct xfrm_state *t;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090064
Alexey Dobriyana92df252010-01-25 10:38:34 +000065 t = xfrm_state_alloc(net);
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 if (t == NULL)
67 goto out;
68
69 t->id.proto = IPPROTO_IPIP;
70 t->id.spi = x->props.saddr.a4;
71 t->id.daddr.a4 = x->id.daddr.a4;
72 memcpy(&t->sel, &x->sel, sizeof(t->sel));
73 t->props.family = AF_INET;
Herbert Xue40b3282007-11-13 21:39:08 -080074 t->props.mode = x->props.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 t->props.saddr.a4 = x->props.saddr.a4;
76 t->props.flags = x->props.flags;
Nicolas Dichtela947b0a2013-02-22 10:54:54 +010077 t->props.extra_flags = x->props.extra_flags;
Jamal Hadi Salimbd557752010-02-22 16:20:22 -080078 memcpy(&t->mark, &x->mark, sizeof(t->mark));
Herbert Xu72cb6962005-06-20 13:18:08 -070079
80 if (xfrm_init_state(t))
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 goto error;
82
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 atomic_set(&t->tunnel_users, 1);
84out:
85 return t;
86
87error:
88 t->km.state = XFRM_STATE_DEAD;
89 xfrm_state_put(t);
90 t = NULL;
91 goto out;
92}
93
94/*
Arjan van de Ven4a3e2f72006-03-20 22:33:17 -080095 * Must be protected by xfrm_cfg_mutex. State and tunnel user references are
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 * always incremented on success.
97 */
98static int ipcomp_tunnel_attach(struct xfrm_state *x)
99{
Alexey Dobriyana92df252010-01-25 10:38:34 +0000100 struct net *net = xs_net(x);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 int err = 0;
102 struct xfrm_state *t;
Jamal Hadi Salimbd557752010-02-22 16:20:22 -0800103 u32 mark = x->mark.v & x->mark.m;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
Jamal Hadi Salimbd557752010-02-22 16:20:22 -0800105 t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr.a4,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900106 x->props.saddr.a4, IPPROTO_IPIP, AF_INET);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 if (!t) {
108 t = ipcomp_tunnel_create(x);
109 if (!t) {
110 err = -EINVAL;
111 goto out;
112 }
113 xfrm_state_insert(t);
114 xfrm_state_hold(t);
115 }
116 x->tunnel = t;
117 atomic_inc(&t->tunnel_users);
118out:
119 return err;
120}
121
Herbert Xu6fccab62008-07-25 02:54:40 -0700122static int ipcomp4_init_state(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123{
David S. Miller2c3abab2008-07-27 03:59:24 -0700124 int err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
Herbert Xue40b3282007-11-13 21:39:08 -0800126 x->props.header_len = 0;
127 switch (x->props.mode) {
128 case XFRM_MODE_TRANSPORT:
129 break;
130 case XFRM_MODE_TUNNEL:
131 x->props.header_len += sizeof(struct iphdr);
132 break;
133 default:
134 goto out;
135 }
136
Herbert Xu6fccab62008-07-25 02:54:40 -0700137 err = ipcomp_init_state(x);
138 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 goto out;
140
Masahide NAKAMURA7e49e6d2006-09-22 15:05:15 -0700141 if (x->props.mode == XFRM_MODE_TUNNEL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 err = ipcomp_tunnel_attach(x);
143 if (err)
Herbert Xu10e74542010-02-15 19:24:30 +0000144 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 }
146
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 err = 0;
148out:
149 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150}
151
Steffen Klassertd0991602014-02-21 08:41:09 +0100152static int ipcomp4_rcv_cb(struct sk_buff *skb, int err)
153{
154 return 0;
155}
156
Eric Dumazet533cb5b2008-01-30 19:11:50 -0800157static const struct xfrm_type ipcomp_type = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 .description = "IPCOMP4",
159 .owner = THIS_MODULE,
160 .proto = IPPROTO_COMP,
Herbert Xu6fccab62008-07-25 02:54:40 -0700161 .init_state = ipcomp4_init_state,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 .destructor = ipcomp_destroy,
163 .input = ipcomp_input,
164 .output = ipcomp_output
165};
166
Steffen Klassertd0991602014-02-21 08:41:09 +0100167static struct xfrm4_protocol ipcomp4_protocol = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 .handler = xfrm4_rcv,
Steffen Klassertd0991602014-02-21 08:41:09 +0100169 .input_handler = xfrm_input,
170 .cb_handler = ipcomp4_rcv_cb,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 .err_handler = ipcomp4_err,
Steffen Klassertd0991602014-02-21 08:41:09 +0100172 .priority = 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173};
174
175static int __init ipcomp4_init(void)
176{
177 if (xfrm_register_type(&ipcomp_type, AF_INET) < 0) {
Joe Perches058bd4d2012-03-11 18:36:11 +0000178 pr_info("%s: can't add xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 return -EAGAIN;
180 }
Steffen Klassertd0991602014-02-21 08:41:09 +0100181 if (xfrm4_protocol_register(&ipcomp4_protocol, IPPROTO_COMP) < 0) {
Joe Perches058bd4d2012-03-11 18:36:11 +0000182 pr_info("%s: can't add protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 xfrm_unregister_type(&ipcomp_type, AF_INET);
184 return -EAGAIN;
185 }
186 return 0;
187}
188
189static void __exit ipcomp4_fini(void)
190{
Steffen Klassertd0991602014-02-21 08:41:09 +0100191 if (xfrm4_protocol_deregister(&ipcomp4_protocol, IPPROTO_COMP) < 0)
Joe Perches058bd4d2012-03-11 18:36:11 +0000192 pr_info("%s: can't remove protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 if (xfrm_unregister_type(&ipcomp_type, AF_INET) < 0)
Joe Perches058bd4d2012-03-11 18:36:11 +0000194 pr_info("%s: can't remove xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195}
196
197module_init(ipcomp4_init);
198module_exit(ipcomp4_fini);
199
200MODULE_LICENSE("GPL");
Herbert Xu6fccab62008-07-25 02:54:40 -0700201MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp/IPv4) - RFC3173");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
203
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700204MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP);