1 /* 2 * IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173 3 * 4 * Copyright (C)2003 USAGI/WIDE Project 5 * 6 * Author Mitsuru KANDA <mk@linux-ipv6.org> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 */ 22 /* 23 * [Memo] 24 * 25 * Outbound: 26 * The compression of IP datagram MUST be done before AH/ESP processing, 27 * fragmentation, and the addition of Hop-by-Hop/Routing header. 28 * 29 * Inbound: 30 * The decompression of IP datagram MUST be done after the reassembly, 31 * AH/ESP processing. 32 */ 33 #include <linux/module.h> 34 #include <net/ip.h> 35 #include <net/xfrm.h> 36 #include <net/ipcomp.h> 37 #include <linux/crypto.h> 38 #include <linux/err.h> 39 #include <linux/pfkeyv2.h> 40 #include <linux/random.h> 41 #include <linux/percpu.h> 42 #include <linux/smp.h> 43 #include <linux/list.h> 44 #include <linux/vmalloc.h> 45 #include <linux/rtnetlink.h> 46 #include <net/icmp.h> 47 #include <net/ipv6.h> 48 #include <net/protocol.h> 49 #include <linux/ipv6.h> 50 #include <linux/icmpv6.h> 51 #include <linux/mutex.h> 52 53 static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 54 u8 type, u8 code, int offset, __be32 info) 55 { 56 struct net *net = dev_net(skb->dev); 57 __be32 spi; 58 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; 59 struct ip_comp_hdr *ipcomph = 60 (struct ip_comp_hdr *)(skb->data + offset); 61 struct xfrm_state *x; 62 63 if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG) 64 return; 65 66 spi = htonl(ntohs(ipcomph->cpi)); 67 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 68 spi, IPPROTO_COMP, AF_INET6); 69 if (!x) 70 return; 71 72 printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/%pI6\n", 73 spi, &iph->daddr); 74 xfrm_state_put(x); 75 } 76 77 static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x) 78 { 79 struct net *net = xs_net(x); 80 struct xfrm_state *t = NULL; 81 82 t = xfrm_state_alloc(net); 83 if (!t) 84 goto out; 85 86 t->id.proto = IPPROTO_IPV6; 87 t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr); 88 if (!t->id.spi) 89 goto error; 90 91 memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr)); 92 memcpy(&t->sel, &x->sel, sizeof(t->sel)); 93 t->props.family = AF_INET6; 94 t->props.mode = x->props.mode; 95 memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr)); 96 memcpy(&t->mark, &x->mark, sizeof(t->mark)); 97 98 if (xfrm_init_state(t)) 99 goto error; 100 101 atomic_set(&t->tunnel_users, 1); 102 103 out: 104 return t; 105 106 error: 107 t->km.state = XFRM_STATE_DEAD; 108 xfrm_state_put(t); 109 t = NULL; 110 goto out; 111 } 112 113 static int ipcomp6_tunnel_attach(struct xfrm_state *x) 114 { 115 struct net *net = xs_net(x); 116 int err = 0; 117 struct xfrm_state *t = NULL; 118 __be32 spi; 119 u32 mark = x->mark.m & x->mark.v; 120 121 spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr); 122 if (spi) 123 t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr, 124 spi, IPPROTO_IPV6, AF_INET6); 125 if (!t) { 126 t = ipcomp6_tunnel_create(x); 127 if (!t) { 128 err = -EINVAL; 129 goto out; 130 } 131 xfrm_state_insert(t); 132 xfrm_state_hold(t); 133 } 134 x->tunnel = t; 135 atomic_inc(&t->tunnel_users); 136 137 out: 138 return err; 139 } 140 141 static int ipcomp6_init_state(struct xfrm_state *x) 142 { 143 int err = -EINVAL; 144 145 x->props.header_len = 0; 146 switch (x->props.mode) { 147 case XFRM_MODE_TRANSPORT: 148 break; 149 case XFRM_MODE_TUNNEL: 150 x->props.header_len += sizeof(struct ipv6hdr); 151 break; 152 default: 153 goto out; 154 } 155 156 err = ipcomp_init_state(x); 157 if (err) 158 goto out; 159 160 if (x->props.mode == XFRM_MODE_TUNNEL) { 161 err = ipcomp6_tunnel_attach(x); 162 if (err) 163 goto out; 164 } 165 166 err = 0; 167 out: 168 return err; 169 } 170 171 static const struct xfrm_type ipcomp6_type = 172 { 173 .description = "IPCOMP6", 174 .owner = THIS_MODULE, 175 .proto = IPPROTO_COMP, 176 .init_state = ipcomp6_init_state, 177 .destructor = ipcomp_destroy, 178 .input = ipcomp_input, 179 .output = ipcomp_output, 180 .hdr_offset = xfrm6_find_1stfragopt, 181 }; 182 183 static const struct inet6_protocol ipcomp6_protocol = 184 { 185 .handler = xfrm6_rcv, 186 .err_handler = ipcomp6_err, 187 .flags = INET6_PROTO_NOPOLICY, 188 }; 189 190 static int __init ipcomp6_init(void) 191 { 192 if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) { 193 printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n"); 194 return -EAGAIN; 195 } 196 if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) { 197 printk(KERN_INFO "ipcomp6 init: can't add protocol\n"); 198 xfrm_unregister_type(&ipcomp6_type, AF_INET6); 199 return -EAGAIN; 200 } 201 return 0; 202 } 203 204 static void __exit ipcomp6_fini(void) 205 { 206 if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) 207 printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n"); 208 if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0) 209 printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n"); 210 } 211 212 module_init(ipcomp6_init); 213 module_exit(ipcomp6_fini); 214 MODULE_LICENSE("GPL"); 215 MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173"); 216 MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>"); 217 218 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP); 219