Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 8 | * Software Foundation; either version 2 of the License, or (at your option) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | * any later version. |
| 10 | * |
| 11 | * Todo: |
| 12 | * - Tunable compression parameters. |
| 13 | * - Compression stats. |
| 14 | * - Adaptive compression. |
| 15 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/module.h> |
Herbert Xu | 4999f36 | 2007-11-07 02:21:47 -0800 | [diff] [blame] | 17 | #include <linux/err.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Arnaldo Carvalho de Melo | 14c8502 | 2005-12-27 02:43:12 -0200 | [diff] [blame] | 23 | #include <net/protocol.h> |
Herbert Xu | 6fccab6 | 2008-07-25 02:54:40 -0700 | [diff] [blame] | 24 | #include <net/sock.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | |
| 26 | static void ipcomp4_err(struct sk_buff *skb, u32 info) |
| 27 | { |
Al Viro | a94cfd1 | 2006-09-27 18:47:24 -0700 | [diff] [blame] | 28 | __be32 spi; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | struct iphdr *iph = (struct iphdr *)skb->data; |
| 30 | struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2)); |
| 31 | struct xfrm_state *x; |
| 32 | |
Arnaldo Carvalho de Melo | 88c7664 | 2007-03-13 14:43:18 -0300 | [diff] [blame] | 33 | if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH || |
| 34 | icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | return; |
| 36 | |
Alexey Dobriyan | 4195f81 | 2006-05-22 16:53:22 -0700 | [diff] [blame] | 37 | spi = htonl(ntohs(ipch->cpi)); |
Alexey Dobriyan | 221df1e | 2008-11-25 17:30:50 -0800 | [diff] [blame] | 38 | x = xfrm_state_lookup(&init_net, (xfrm_address_t *)&iph->daddr, |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 39 | spi, IPPROTO_COMP, AF_INET); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | if (!x) |
| 41 | return; |
Harvey Harrison | 673d57e | 2008-10-31 00:53:57 -0700 | [diff] [blame] | 42 | NETDEBUG(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/%pI4\n", |
| 43 | spi, &iph->daddr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | xfrm_state_put(x); |
| 45 | } |
| 46 | |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 47 | /* We always hold one tunnel user reference to indicate a tunnel */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x) |
| 49 | { |
| 50 | struct xfrm_state *t; |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 51 | |
Alexey Dobriyan | 673c09b | 2008-11-25 17:15:16 -0800 | [diff] [blame] | 52 | t = xfrm_state_alloc(&init_net); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | if (t == NULL) |
| 54 | goto out; |
| 55 | |
| 56 | t->id.proto = IPPROTO_IPIP; |
| 57 | t->id.spi = x->props.saddr.a4; |
| 58 | t->id.daddr.a4 = x->id.daddr.a4; |
| 59 | memcpy(&t->sel, &x->sel, sizeof(t->sel)); |
| 60 | t->props.family = AF_INET; |
Herbert Xu | e40b328 | 2007-11-13 21:39:08 -0800 | [diff] [blame] | 61 | t->props.mode = x->props.mode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | t->props.saddr.a4 = x->props.saddr.a4; |
| 63 | t->props.flags = x->props.flags; |
Herbert Xu | 72cb696 | 2005-06-20 13:18:08 -0700 | [diff] [blame] | 64 | |
| 65 | if (xfrm_init_state(t)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | goto error; |
| 67 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | atomic_set(&t->tunnel_users, 1); |
| 69 | out: |
| 70 | return t; |
| 71 | |
| 72 | error: |
| 73 | t->km.state = XFRM_STATE_DEAD; |
| 74 | xfrm_state_put(t); |
| 75 | t = NULL; |
| 76 | goto out; |
| 77 | } |
| 78 | |
| 79 | /* |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 80 | * Must be protected by xfrm_cfg_mutex. State and tunnel user references are |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | * always incremented on success. |
| 82 | */ |
| 83 | static int ipcomp_tunnel_attach(struct xfrm_state *x) |
| 84 | { |
| 85 | int err = 0; |
| 86 | struct xfrm_state *t; |
| 87 | |
Alexey Dobriyan | 221df1e | 2008-11-25 17:30:50 -0800 | [diff] [blame] | 88 | t = xfrm_state_lookup(&init_net, (xfrm_address_t *)&x->id.daddr.a4, |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 89 | x->props.saddr.a4, IPPROTO_IPIP, AF_INET); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | if (!t) { |
| 91 | t = ipcomp_tunnel_create(x); |
| 92 | if (!t) { |
| 93 | err = -EINVAL; |
| 94 | goto out; |
| 95 | } |
| 96 | xfrm_state_insert(t); |
| 97 | xfrm_state_hold(t); |
| 98 | } |
| 99 | x->tunnel = t; |
| 100 | atomic_inc(&t->tunnel_users); |
| 101 | out: |
| 102 | return err; |
| 103 | } |
| 104 | |
Herbert Xu | 6fccab6 | 2008-07-25 02:54:40 -0700 | [diff] [blame] | 105 | static int ipcomp4_init_state(struct xfrm_state *x) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | { |
David S. Miller | 2c3abab | 2008-07-27 03:59:24 -0700 | [diff] [blame] | 107 | int err = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | |
Herbert Xu | e40b328 | 2007-11-13 21:39:08 -0800 | [diff] [blame] | 109 | x->props.header_len = 0; |
| 110 | switch (x->props.mode) { |
| 111 | case XFRM_MODE_TRANSPORT: |
| 112 | break; |
| 113 | case XFRM_MODE_TUNNEL: |
| 114 | x->props.header_len += sizeof(struct iphdr); |
| 115 | break; |
| 116 | default: |
| 117 | goto out; |
| 118 | } |
| 119 | |
Herbert Xu | 6fccab6 | 2008-07-25 02:54:40 -0700 | [diff] [blame] | 120 | err = ipcomp_init_state(x); |
| 121 | if (err) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | goto out; |
| 123 | |
Masahide NAKAMURA | 7e49e6d | 2006-09-22 15:05:15 -0700 | [diff] [blame] | 124 | if (x->props.mode == XFRM_MODE_TUNNEL) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | err = ipcomp_tunnel_attach(x); |
| 126 | if (err) |
Herbert Xu | 10e7454 | 2010-02-15 19:24:30 +0000 | [diff] [blame] | 127 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | } |
| 129 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | err = 0; |
| 131 | out: |
| 132 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | } |
| 134 | |
Eric Dumazet | 533cb5b | 2008-01-30 19:11:50 -0800 | [diff] [blame] | 135 | static const struct xfrm_type ipcomp_type = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | .description = "IPCOMP4", |
| 137 | .owner = THIS_MODULE, |
| 138 | .proto = IPPROTO_COMP, |
Herbert Xu | 6fccab6 | 2008-07-25 02:54:40 -0700 | [diff] [blame] | 139 | .init_state = ipcomp4_init_state, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | .destructor = ipcomp_destroy, |
| 141 | .input = ipcomp_input, |
| 142 | .output = ipcomp_output |
| 143 | }; |
| 144 | |
Alexey Dobriyan | 3261309 | 2009-09-14 12:21:47 +0000 | [diff] [blame] | 145 | static const struct net_protocol ipcomp4_protocol = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | .handler = xfrm4_rcv, |
| 147 | .err_handler = ipcomp4_err, |
| 148 | .no_policy = 1, |
| 149 | }; |
| 150 | |
| 151 | static int __init ipcomp4_init(void) |
| 152 | { |
| 153 | if (xfrm_register_type(&ipcomp_type, AF_INET) < 0) { |
| 154 | printk(KERN_INFO "ipcomp init: can't add xfrm type\n"); |
| 155 | return -EAGAIN; |
| 156 | } |
| 157 | if (inet_add_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0) { |
| 158 | printk(KERN_INFO "ipcomp init: can't add protocol\n"); |
| 159 | xfrm_unregister_type(&ipcomp_type, AF_INET); |
| 160 | return -EAGAIN; |
| 161 | } |
| 162 | return 0; |
| 163 | } |
| 164 | |
| 165 | static void __exit ipcomp4_fini(void) |
| 166 | { |
| 167 | if (inet_del_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0) |
| 168 | printk(KERN_INFO "ip ipcomp close: can't remove protocol\n"); |
| 169 | if (xfrm_unregister_type(&ipcomp_type, AF_INET) < 0) |
| 170 | printk(KERN_INFO "ip ipcomp close: can't remove xfrm type\n"); |
| 171 | } |
| 172 | |
| 173 | module_init(ipcomp4_init); |
| 174 | module_exit(ipcomp4_fini); |
| 175 | |
| 176 | MODULE_LICENSE("GPL"); |
Herbert Xu | 6fccab6 | 2008-07-25 02:54:40 -0700 | [diff] [blame] | 177 | MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp/IPv4) - RFC3173"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>"); |
| 179 | |
Masahide NAKAMURA | d3d6dd3 | 2007-06-26 23:57:49 -0700 | [diff] [blame] | 180 | MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP); |