1 /* 2 * Copyright (C)2003,2004 USAGI/WIDE Project 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 * 18 * Authors Mitsuru KANDA <mk@linux-ipv6.org> 19 * YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> 20 * 21 * Based on net/ipv4/xfrm4_tunnel.c 22 * 23 */ 24 #include <linux/module.h> 25 #include <linux/xfrm.h> 26 #include <linux/slab.h> 27 #include <linux/rculist.h> 28 #include <net/ip.h> 29 #include <net/xfrm.h> 30 #include <net/ipv6.h> 31 #include <linux/ipv6.h> 32 #include <linux/icmpv6.h> 33 #include <linux/mutex.h> 34 #include <net/netns/generic.h> 35 36 #define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256 37 #define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256 38 39 #define XFRM6_TUNNEL_SPI_MIN 1 40 #define XFRM6_TUNNEL_SPI_MAX 0xffffffff 41 42 struct xfrm6_tunnel_net { 43 struct hlist_head spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE]; 44 struct hlist_head spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE]; 45 u32 spi; 46 }; 47 48 static int xfrm6_tunnel_net_id __read_mostly; 49 static inline struct xfrm6_tunnel_net *xfrm6_tunnel_pernet(struct net *net) 50 { 51 return net_generic(net, xfrm6_tunnel_net_id); 52 } 53 54 /* 55 * xfrm_tunnel_spi things are for allocating unique id ("spi") 56 * per xfrm_address_t. 57 */ 58 struct xfrm6_tunnel_spi { 59 struct hlist_node list_byaddr; 60 struct hlist_node list_byspi; 61 xfrm_address_t addr; 62 u32 spi; 63 atomic_t refcnt; 64 struct rcu_head rcu_head; 65 }; 66 67 static DEFINE_SPINLOCK(xfrm6_tunnel_spi_lock); 68 69 static struct kmem_cache *xfrm6_tunnel_spi_kmem __read_mostly; 70 71 static inline unsigned xfrm6_tunnel_spi_hash_byaddr(xfrm_address_t *addr) 72 { 73 unsigned h; 74 75 h = (__force u32)(addr->a6[0] ^ addr->a6[1] ^ addr->a6[2] ^ addr->a6[3]); 76 h ^= h >> 16; 77 h ^= h >> 8; 78 h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1; 79 80 return h; 81 } 82 83 static inline unsigned xfrm6_tunnel_spi_hash_byspi(u32 spi) 84 { 85 return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE; 86 } 87 88 static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(struct net *net, xfrm_address_t *saddr) 89 { 90 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 91 struct xfrm6_tunnel_spi *x6spi; 92 struct hlist_node *pos; 93 94 hlist_for_each_entry_rcu(x6spi, pos, 95 &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)], 96 list_byaddr) { 97 if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) 98 return x6spi; 99 } 100 101 return NULL; 102 } 103 104 __be32 xfrm6_tunnel_spi_lookup(struct net *net, xfrm_address_t *saddr) 105 { 106 struct xfrm6_tunnel_spi *x6spi; 107 u32 spi; 108 109 rcu_read_lock_bh(); 110 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr); 111 spi = x6spi ? x6spi->spi : 0; 112 rcu_read_unlock_bh(); 113 return htonl(spi); 114 } 115 116 EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup); 117 118 static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi) 119 { 120 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 121 struct xfrm6_tunnel_spi *x6spi; 122 int index = xfrm6_tunnel_spi_hash_byspi(spi); 123 struct hlist_node *pos; 124 125 hlist_for_each_entry(x6spi, pos, 126 &xfrm6_tn->spi_byspi[index], 127 list_byspi) { 128 if (x6spi->spi == spi) 129 return -1; 130 } 131 return index; 132 } 133 134 static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr) 135 { 136 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 137 u32 spi; 138 struct xfrm6_tunnel_spi *x6spi; 139 int index; 140 141 if (xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN || 142 xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX) 143 xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN; 144 else 145 xfrm6_tn->spi++; 146 147 for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) { 148 index = __xfrm6_tunnel_spi_check(net, spi); 149 if (index >= 0) 150 goto alloc_spi; 151 } 152 for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) { 153 index = __xfrm6_tunnel_spi_check(net, spi); 154 if (index >= 0) 155 goto alloc_spi; 156 } 157 spi = 0; 158 goto out; 159 alloc_spi: 160 xfrm6_tn->spi = spi; 161 x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC); 162 if (!x6spi) 163 goto out; 164 165 memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr)); 166 x6spi->spi = spi; 167 atomic_set(&x6spi->refcnt, 1); 168 169 hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]); 170 171 index = xfrm6_tunnel_spi_hash_byaddr(saddr); 172 hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]); 173 out: 174 return spi; 175 } 176 177 __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr) 178 { 179 struct xfrm6_tunnel_spi *x6spi; 180 u32 spi; 181 182 spin_lock_bh(&xfrm6_tunnel_spi_lock); 183 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr); 184 if (x6spi) { 185 atomic_inc(&x6spi->refcnt); 186 spi = x6spi->spi; 187 } else 188 spi = __xfrm6_tunnel_alloc_spi(net, saddr); 189 spin_unlock_bh(&xfrm6_tunnel_spi_lock); 190 191 return htonl(spi); 192 } 193 194 EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi); 195 196 static void x6spi_destroy_rcu(struct rcu_head *head) 197 { 198 kmem_cache_free(xfrm6_tunnel_spi_kmem, 199 container_of(head, struct xfrm6_tunnel_spi, rcu_head)); 200 } 201 202 void xfrm6_tunnel_free_spi(struct net *net, xfrm_address_t *saddr) 203 { 204 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 205 struct xfrm6_tunnel_spi *x6spi; 206 struct hlist_node *pos, *n; 207 208 spin_lock_bh(&xfrm6_tunnel_spi_lock); 209 210 hlist_for_each_entry_safe(x6spi, pos, n, 211 &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)], 212 list_byaddr) 213 { 214 if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) { 215 if (atomic_dec_and_test(&x6spi->refcnt)) { 216 hlist_del_rcu(&x6spi->list_byaddr); 217 hlist_del_rcu(&x6spi->list_byspi); 218 call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu); 219 break; 220 } 221 } 222 } 223 spin_unlock_bh(&xfrm6_tunnel_spi_lock); 224 } 225 226 EXPORT_SYMBOL(xfrm6_tunnel_free_spi); 227 228 static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) 229 { 230 skb_push(skb, -skb_network_offset(skb)); 231 return 0; 232 } 233 234 static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) 235 { 236 return skb_network_header(skb)[IP6CB(skb)->nhoff]; 237 } 238 239 static int xfrm6_tunnel_rcv(struct sk_buff *skb) 240 { 241 struct net *net = dev_net(skb->dev); 242 struct ipv6hdr *iph = ipv6_hdr(skb); 243 __be32 spi; 244 245 spi = xfrm6_tunnel_spi_lookup(net, (xfrm_address_t *)&iph->saddr); 246 return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi) > 0 ? : 0; 247 } 248 249 static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 250 u8 type, u8 code, int offset, __be32 info) 251 { 252 /* xfrm6_tunnel native err handling */ 253 switch (type) { 254 case ICMPV6_DEST_UNREACH: 255 switch (code) { 256 case ICMPV6_NOROUTE: 257 case ICMPV6_ADM_PROHIBITED: 258 case ICMPV6_NOT_NEIGHBOUR: 259 case ICMPV6_ADDR_UNREACH: 260 case ICMPV6_PORT_UNREACH: 261 default: 262 break; 263 } 264 break; 265 case ICMPV6_PKT_TOOBIG: 266 break; 267 case ICMPV6_TIME_EXCEED: 268 switch (code) { 269 case ICMPV6_EXC_HOPLIMIT: 270 break; 271 case ICMPV6_EXC_FRAGTIME: 272 default: 273 break; 274 } 275 break; 276 case ICMPV6_PARAMPROB: 277 switch (code) { 278 case ICMPV6_HDR_FIELD: break; 279 case ICMPV6_UNK_NEXTHDR: break; 280 case ICMPV6_UNK_OPTION: break; 281 } 282 break; 283 default: 284 break; 285 } 286 287 return 0; 288 } 289 290 static int xfrm6_tunnel_init_state(struct xfrm_state *x) 291 { 292 if (x->props.mode != XFRM_MODE_TUNNEL) 293 return -EINVAL; 294 295 if (x->encap) 296 return -EINVAL; 297 298 x->props.header_len = sizeof(struct ipv6hdr); 299 300 return 0; 301 } 302 303 static void xfrm6_tunnel_destroy(struct xfrm_state *x) 304 { 305 struct net *net = xs_net(x); 306 307 xfrm6_tunnel_free_spi(net, (xfrm_address_t *)&x->props.saddr); 308 } 309 310 static const struct xfrm_type xfrm6_tunnel_type = { 311 .description = "IP6IP6", 312 .owner = THIS_MODULE, 313 .proto = IPPROTO_IPV6, 314 .init_state = xfrm6_tunnel_init_state, 315 .destructor = xfrm6_tunnel_destroy, 316 .input = xfrm6_tunnel_input, 317 .output = xfrm6_tunnel_output, 318 }; 319 320 static struct xfrm6_tunnel xfrm6_tunnel_handler = { 321 .handler = xfrm6_tunnel_rcv, 322 .err_handler = xfrm6_tunnel_err, 323 .priority = 2, 324 }; 325 326 static struct xfrm6_tunnel xfrm46_tunnel_handler = { 327 .handler = xfrm6_tunnel_rcv, 328 .err_handler = xfrm6_tunnel_err, 329 .priority = 2, 330 }; 331 332 static int __net_init xfrm6_tunnel_net_init(struct net *net) 333 { 334 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 335 unsigned int i; 336 337 for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) 338 INIT_HLIST_HEAD(&xfrm6_tn->spi_byaddr[i]); 339 for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) 340 INIT_HLIST_HEAD(&xfrm6_tn->spi_byspi[i]); 341 xfrm6_tn->spi = 0; 342 343 return 0; 344 } 345 346 static void __net_exit xfrm6_tunnel_net_exit(struct net *net) 347 { 348 } 349 350 static struct pernet_operations xfrm6_tunnel_net_ops = { 351 .init = xfrm6_tunnel_net_init, 352 .exit = xfrm6_tunnel_net_exit, 353 .id = &xfrm6_tunnel_net_id, 354 .size = sizeof(struct xfrm6_tunnel_net), 355 }; 356 357 static int __init xfrm6_tunnel_init(void) 358 { 359 int rv; 360 361 xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi", 362 sizeof(struct xfrm6_tunnel_spi), 363 0, SLAB_HWCACHE_ALIGN, 364 NULL); 365 if (!xfrm6_tunnel_spi_kmem) 366 return -ENOMEM; 367 rv = register_pernet_subsys(&xfrm6_tunnel_net_ops); 368 if (rv < 0) 369 goto out_pernet; 370 rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6); 371 if (rv < 0) 372 goto out_type; 373 rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6); 374 if (rv < 0) 375 goto out_xfrm6; 376 rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET); 377 if (rv < 0) 378 goto out_xfrm46; 379 return 0; 380 381 out_xfrm46: 382 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6); 383 out_xfrm6: 384 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 385 out_type: 386 unregister_pernet_subsys(&xfrm6_tunnel_net_ops); 387 out_pernet: 388 kmem_cache_destroy(xfrm6_tunnel_spi_kmem); 389 return rv; 390 } 391 392 static void __exit xfrm6_tunnel_fini(void) 393 { 394 xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET); 395 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6); 396 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 397 unregister_pernet_subsys(&xfrm6_tunnel_net_ops); 398 kmem_cache_destroy(xfrm6_tunnel_spi_kmem); 399 } 400 401 module_init(xfrm6_tunnel_init); 402 module_exit(xfrm6_tunnel_fini); 403 MODULE_LICENSE("GPL"); 404 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6); 405