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 struct ipv6hdr *iph = (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, (xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6); 68 if (!x) 69 return; 70 71 printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/%pI6\n", 72 spi, &iph->daddr); 73 xfrm_state_put(x); 74 } 75 76 static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x) 77 { 78 struct net *net = xs_net(x); 79 struct xfrm_state *t = NULL; 80 81 t = xfrm_state_alloc(net); 82 if (!t) 83 goto out; 84 85 t->id.proto = IPPROTO_IPV6; 86 t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr); 87 if (!t->id.spi) 88 goto error; 89 90 memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr)); 91 memcpy(&t->sel, &x->sel, sizeof(t->sel)); 92 t->props.family = AF_INET6; 93 t->props.mode = x->props.mode; 94 memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr)); 95 memcpy(&t->mark, &x->mark, sizeof(t->mark)); 96 97 if (xfrm_init_state(t)) 98 goto error; 99 100 atomic_set(&t->tunnel_users, 1); 101 102 out: 103 return t; 104 105 error: 106 t->km.state = XFRM_STATE_DEAD; 107 xfrm_state_put(t); 108 t = NULL; 109 goto out; 110 } 111 112 static int ipcomp6_tunnel_attach(struct xfrm_state *x) 113 { 114 struct net *net = xs_net(x); 115 int err = 0; 116 struct xfrm_state *t = NULL; 117 __be32 spi; 118 u32 mark = x->mark.m & x->mark.v; 119 120 spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr); 121 if (spi) 122 t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr, 123 spi, IPPROTO_IPV6, AF_INET6); 124 if (!t) { 125 t = ipcomp6_tunnel_create(x); 126 if (!t) { 127 err = -EINVAL; 128 goto out; 129 } 130 xfrm_state_insert(t); 131 xfrm_state_hold(t); 132 } 133 x->tunnel = t; 134 atomic_inc(&t->tunnel_users); 135 136 out: 137 return err; 138 } 139 140 static int ipcomp6_init_state(struct xfrm_state *x) 141 { 142 int err = -EINVAL; 143 144 x->props.header_len = 0; 145 switch (x->props.mode) { 146 case XFRM_MODE_TRANSPORT: 147 break; 148 case XFRM_MODE_TUNNEL: 149 x->props.header_len += sizeof(struct ipv6hdr); 150 break; 151 default: 152 goto out; 153 } 154 155 err = ipcomp_init_state(x); 156 if (err) 157 goto out; 158 159 if (x->props.mode == XFRM_MODE_TUNNEL) { 160 err = ipcomp6_tunnel_attach(x); 161 if (err) 162 goto out; 163 } 164 165 err = 0; 166 out: 167 return err; 168 } 169 170 static const struct xfrm_type ipcomp6_type = 171 { 172 .description = "IPCOMP6", 173 .owner = THIS_MODULE, 174 .proto = IPPROTO_COMP, 175 .init_state = ipcomp6_init_state, 176 .destructor = ipcomp_destroy, 177 .input = ipcomp_input, 178 .output = ipcomp_output, 179 .hdr_offset = xfrm6_find_1stfragopt, 180 }; 181 182 static const struct inet6_protocol ipcomp6_protocol = 183 { 184 .handler = xfrm6_rcv, 185 .err_handler = ipcomp6_err, 186 .flags = INET6_PROTO_NOPOLICY, 187 }; 188 189 static int __init ipcomp6_init(void) 190 { 191 if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) { 192 printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n"); 193 return -EAGAIN; 194 } 195 if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) { 196 printk(KERN_INFO "ipcomp6 init: can't add protocol\n"); 197 xfrm_unregister_type(&ipcomp6_type, AF_INET6); 198 return -EAGAIN; 199 } 200 return 0; 201 } 202 203 static void __exit ipcomp6_fini(void) 204 { 205 if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) 206 printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n"); 207 if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0) 208 printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n"); 209 } 210 211 module_init(ipcomp6_init); 212 module_exit(ipcomp6_fini); 213 MODULE_LICENSE("GPL"); 214 MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173"); 215 MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>"); 216 217 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP); 218