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 34 #define pr_fmt(fmt) "IPv6: " fmt 35 36 #include <linux/module.h> 37 #include <net/ip.h> 38 #include <net/xfrm.h> 39 #include <net/ipcomp.h> 40 #include <linux/crypto.h> 41 #include <linux/err.h> 42 #include <linux/pfkeyv2.h> 43 #include <linux/random.h> 44 #include <linux/percpu.h> 45 #include <linux/smp.h> 46 #include <linux/list.h> 47 #include <linux/vmalloc.h> 48 #include <linux/rtnetlink.h> 49 #include <net/ip6_route.h> 50 #include <net/icmp.h> 51 #include <net/ipv6.h> 52 #include <net/protocol.h> 53 #include <linux/ipv6.h> 54 #include <linux/icmpv6.h> 55 #include <linux/mutex.h> 56 57 static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 58 u8 type, u8 code, int offset, __be32 info) 59 { 60 struct net *net = dev_net(skb->dev); 61 __be32 spi; 62 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; 63 struct ip_comp_hdr *ipcomph = 64 (struct ip_comp_hdr *)(skb->data + offset); 65 struct xfrm_state *x; 66 67 if (type != ICMPV6_DEST_UNREACH && 68 type != ICMPV6_PKT_TOOBIG && 69 type != NDISC_REDIRECT) 70 return; 71 72 spi = htonl(ntohs(ipcomph->cpi)); 73 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, 74 spi, IPPROTO_COMP, AF_INET6); 75 if (!x) 76 return; 77 78 if (type == NDISC_REDIRECT) 79 ip6_redirect(skb, net, 0, 0); 80 else 81 ip6_update_pmtu(skb, net, info, 0, 0); 82 xfrm_state_put(x); 83 } 84 85 static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x) 86 { 87 struct net *net = xs_net(x); 88 struct xfrm_state *t = NULL; 89 90 t = xfrm_state_alloc(net); 91 if (!t) 92 goto out; 93 94 t->id.proto = IPPROTO_IPV6; 95 t->id.spi = xfrm6_tunnel_alloc_spi(net, (xfrm_address_t *)&x->props.saddr); 96 if (!t->id.spi) 97 goto error; 98 99 memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr)); 100 memcpy(&t->sel, &x->sel, sizeof(t->sel)); 101 t->props.family = AF_INET6; 102 t->props.mode = x->props.mode; 103 memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr)); 104 memcpy(&t->mark, &x->mark, sizeof(t->mark)); 105 106 if (xfrm_init_state(t)) 107 goto error; 108 109 atomic_set(&t->tunnel_users, 1); 110 111 out: 112 return t; 113 114 error: 115 t->km.state = XFRM_STATE_DEAD; 116 xfrm_state_put(t); 117 t = NULL; 118 goto out; 119 } 120 121 static int ipcomp6_tunnel_attach(struct xfrm_state *x) 122 { 123 struct net *net = xs_net(x); 124 int err = 0; 125 struct xfrm_state *t = NULL; 126 __be32 spi; 127 u32 mark = x->mark.m & x->mark.v; 128 129 spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&x->props.saddr); 130 if (spi) 131 t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr, 132 spi, IPPROTO_IPV6, AF_INET6); 133 if (!t) { 134 t = ipcomp6_tunnel_create(x); 135 if (!t) { 136 err = -EINVAL; 137 goto out; 138 } 139 xfrm_state_insert(t); 140 xfrm_state_hold(t); 141 } 142 x->tunnel = t; 143 atomic_inc(&t->tunnel_users); 144 145 out: 146 return err; 147 } 148 149 static int ipcomp6_init_state(struct xfrm_state *x) 150 { 151 int err = -EINVAL; 152 153 x->props.header_len = 0; 154 switch (x->props.mode) { 155 case XFRM_MODE_TRANSPORT: 156 break; 157 case XFRM_MODE_TUNNEL: 158 x->props.header_len += sizeof(struct ipv6hdr); 159 break; 160 default: 161 goto out; 162 } 163 164 err = ipcomp_init_state(x); 165 if (err) 166 goto out; 167 168 if (x->props.mode == XFRM_MODE_TUNNEL) { 169 err = ipcomp6_tunnel_attach(x); 170 if (err) 171 goto out; 172 } 173 174 err = 0; 175 out: 176 return err; 177 } 178 179 static const struct xfrm_type ipcomp6_type = 180 { 181 .description = "IPCOMP6", 182 .owner = THIS_MODULE, 183 .proto = IPPROTO_COMP, 184 .init_state = ipcomp6_init_state, 185 .destructor = ipcomp_destroy, 186 .input = ipcomp_input, 187 .output = ipcomp_output, 188 .hdr_offset = xfrm6_find_1stfragopt, 189 }; 190 191 static const struct inet6_protocol ipcomp6_protocol = 192 { 193 .handler = xfrm6_rcv, 194 .err_handler = ipcomp6_err, 195 .flags = INET6_PROTO_NOPOLICY, 196 }; 197 198 static int __init ipcomp6_init(void) 199 { 200 if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) { 201 pr_info("%s: can't add xfrm type\n", __func__); 202 return -EAGAIN; 203 } 204 if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) { 205 pr_info("%s: can't add protocol\n", __func__); 206 xfrm_unregister_type(&ipcomp6_type, AF_INET6); 207 return -EAGAIN; 208 } 209 return 0; 210 } 211 212 static void __exit ipcomp6_fini(void) 213 { 214 if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) 215 pr_info("%s: can't remove protocol\n", __func__); 216 if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0) 217 pr_info("%s: can't remove xfrm type\n", __func__); 218 } 219 220 module_init(ipcomp6_init); 221 module_exit(ipcomp6_fini); 222 MODULE_LICENSE("GPL"); 223 MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173"); 224 MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>"); 225 226 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP); 227