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, see <http://www.gnu.org/licenses/>. 16 * 17 * Authors Mitsuru KANDA <mk@linux-ipv6.org> 18 * YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> 19 * 20 * Based on net/ipv4/xfrm4_tunnel.c 21 * 22 */ 23 #include <linux/module.h> 24 #include <linux/xfrm.h> 25 #include <linux/slab.h> 26 #include <linux/rculist.h> 27 #include <net/ip.h> 28 #include <net/xfrm.h> 29 #include <net/ipv6.h> 30 #include <linux/ipv6.h> 31 #include <linux/icmpv6.h> 32 #include <linux/mutex.h> 33 #include <net/netns/generic.h> 34 35 #define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256 36 #define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256 37 38 #define XFRM6_TUNNEL_SPI_MIN 1 39 #define XFRM6_TUNNEL_SPI_MAX 0xffffffff 40 41 struct xfrm6_tunnel_net { 42 struct hlist_head spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE]; 43 struct hlist_head spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE]; 44 u32 spi; 45 }; 46 47 static unsigned int xfrm6_tunnel_net_id __read_mostly; 48 static inline struct xfrm6_tunnel_net *xfrm6_tunnel_pernet(struct net *net) 49 { 50 return net_generic(net, xfrm6_tunnel_net_id); 51 } 52 53 /* 54 * xfrm_tunnel_spi things are for allocating unique id ("spi") 55 * per xfrm_address_t. 56 */ 57 struct xfrm6_tunnel_spi { 58 struct hlist_node list_byaddr; 59 struct hlist_node list_byspi; 60 xfrm_address_t addr; 61 u32 spi; 62 refcount_t refcnt; 63 struct rcu_head rcu_head; 64 }; 65 66 static DEFINE_SPINLOCK(xfrm6_tunnel_spi_lock); 67 68 static struct kmem_cache *xfrm6_tunnel_spi_kmem __read_mostly; 69 70 static inline unsigned int xfrm6_tunnel_spi_hash_byaddr(const xfrm_address_t *addr) 71 { 72 unsigned int h; 73 74 h = ipv6_addr_hash((const struct in6_addr *)addr); 75 h ^= h >> 16; 76 h ^= h >> 8; 77 h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1; 78 79 return h; 80 } 81 82 static inline unsigned int xfrm6_tunnel_spi_hash_byspi(u32 spi) 83 { 84 return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE; 85 } 86 87 static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr) 88 { 89 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 90 struct xfrm6_tunnel_spi *x6spi; 91 92 hlist_for_each_entry_rcu(x6spi, 93 &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)], 94 list_byaddr) { 95 if (xfrm6_addr_equal(&x6spi->addr, saddr)) 96 return x6spi; 97 } 98 99 return NULL; 100 } 101 102 __be32 xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr) 103 { 104 struct xfrm6_tunnel_spi *x6spi; 105 u32 spi; 106 107 rcu_read_lock_bh(); 108 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr); 109 spi = x6spi ? x6spi->spi : 0; 110 rcu_read_unlock_bh(); 111 return htonl(spi); 112 } 113 EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup); 114 115 static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi) 116 { 117 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 118 struct xfrm6_tunnel_spi *x6spi; 119 int index = xfrm6_tunnel_spi_hash_byspi(spi); 120 121 hlist_for_each_entry(x6spi, 122 &xfrm6_tn->spi_byspi[index], 123 list_byspi) { 124 if (x6spi->spi == spi) 125 return -1; 126 } 127 return index; 128 } 129 130 static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr) 131 { 132 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 133 u32 spi; 134 struct xfrm6_tunnel_spi *x6spi; 135 int index; 136 137 if (xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN || 138 xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX) 139 xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN; 140 else 141 xfrm6_tn->spi++; 142 143 for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) { 144 index = __xfrm6_tunnel_spi_check(net, spi); 145 if (index >= 0) 146 goto alloc_spi; 147 } 148 for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) { 149 index = __xfrm6_tunnel_spi_check(net, spi); 150 if (index >= 0) 151 goto alloc_spi; 152 } 153 spi = 0; 154 goto out; 155 alloc_spi: 156 xfrm6_tn->spi = spi; 157 x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC); 158 if (!x6spi) 159 goto out; 160 161 memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr)); 162 x6spi->spi = spi; 163 refcount_set(&x6spi->refcnt, 1); 164 165 hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]); 166 167 index = xfrm6_tunnel_spi_hash_byaddr(saddr); 168 hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]); 169 out: 170 return spi; 171 } 172 173 __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr) 174 { 175 struct xfrm6_tunnel_spi *x6spi; 176 u32 spi; 177 178 spin_lock_bh(&xfrm6_tunnel_spi_lock); 179 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr); 180 if (x6spi) { 181 refcount_inc(&x6spi->refcnt); 182 spi = x6spi->spi; 183 } else 184 spi = __xfrm6_tunnel_alloc_spi(net, saddr); 185 spin_unlock_bh(&xfrm6_tunnel_spi_lock); 186 187 return htonl(spi); 188 } 189 EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi); 190 191 static void x6spi_destroy_rcu(struct rcu_head *head) 192 { 193 kmem_cache_free(xfrm6_tunnel_spi_kmem, 194 container_of(head, struct xfrm6_tunnel_spi, rcu_head)); 195 } 196 197 static void xfrm6_tunnel_free_spi(struct net *net, xfrm_address_t *saddr) 198 { 199 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 200 struct xfrm6_tunnel_spi *x6spi; 201 struct hlist_node *n; 202 203 spin_lock_bh(&xfrm6_tunnel_spi_lock); 204 205 hlist_for_each_entry_safe(x6spi, n, 206 &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)], 207 list_byaddr) 208 { 209 if (xfrm6_addr_equal(&x6spi->addr, saddr)) { 210 if (refcount_dec_and_test(&x6spi->refcnt)) { 211 hlist_del_rcu(&x6spi->list_byaddr); 212 hlist_del_rcu(&x6spi->list_byspi); 213 call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu); 214 break; 215 } 216 } 217 } 218 spin_unlock_bh(&xfrm6_tunnel_spi_lock); 219 } 220 221 static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) 222 { 223 skb_push(skb, -skb_network_offset(skb)); 224 return 0; 225 } 226 227 static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) 228 { 229 return skb_network_header(skb)[IP6CB(skb)->nhoff]; 230 } 231 232 static int xfrm6_tunnel_rcv(struct sk_buff *skb) 233 { 234 struct net *net = dev_net(skb->dev); 235 const struct ipv6hdr *iph = ipv6_hdr(skb); 236 __be32 spi; 237 238 spi = xfrm6_tunnel_spi_lookup(net, (const xfrm_address_t *)&iph->saddr); 239 return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi, NULL); 240 } 241 242 static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 243 u8 type, u8 code, int offset, __be32 info) 244 { 245 /* xfrm6_tunnel native err handling */ 246 switch (type) { 247 case ICMPV6_DEST_UNREACH: 248 switch (code) { 249 case ICMPV6_NOROUTE: 250 case ICMPV6_ADM_PROHIBITED: 251 case ICMPV6_NOT_NEIGHBOUR: 252 case ICMPV6_ADDR_UNREACH: 253 case ICMPV6_PORT_UNREACH: 254 default: 255 break; 256 } 257 break; 258 case ICMPV6_PKT_TOOBIG: 259 break; 260 case ICMPV6_TIME_EXCEED: 261 switch (code) { 262 case ICMPV6_EXC_HOPLIMIT: 263 break; 264 case ICMPV6_EXC_FRAGTIME: 265 default: 266 break; 267 } 268 break; 269 case ICMPV6_PARAMPROB: 270 switch (code) { 271 case ICMPV6_HDR_FIELD: break; 272 case ICMPV6_UNK_NEXTHDR: break; 273 case ICMPV6_UNK_OPTION: break; 274 } 275 break; 276 default: 277 break; 278 } 279 280 return 0; 281 } 282 283 static int xfrm6_tunnel_init_state(struct xfrm_state *x) 284 { 285 if (x->props.mode != XFRM_MODE_TUNNEL) 286 return -EINVAL; 287 288 if (x->encap) 289 return -EINVAL; 290 291 x->props.header_len = sizeof(struct ipv6hdr); 292 293 return 0; 294 } 295 296 static void xfrm6_tunnel_destroy(struct xfrm_state *x) 297 { 298 struct net *net = xs_net(x); 299 300 xfrm6_tunnel_free_spi(net, (xfrm_address_t *)&x->props.saddr); 301 } 302 303 static const struct xfrm_type xfrm6_tunnel_type = { 304 .description = "IP6IP6", 305 .owner = THIS_MODULE, 306 .proto = IPPROTO_IPV6, 307 .init_state = xfrm6_tunnel_init_state, 308 .destructor = xfrm6_tunnel_destroy, 309 .input = xfrm6_tunnel_input, 310 .output = xfrm6_tunnel_output, 311 }; 312 313 static struct xfrm6_tunnel xfrm6_tunnel_handler __read_mostly = { 314 .handler = xfrm6_tunnel_rcv, 315 .err_handler = xfrm6_tunnel_err, 316 .priority = 2, 317 }; 318 319 static struct xfrm6_tunnel xfrm46_tunnel_handler __read_mostly = { 320 .handler = xfrm6_tunnel_rcv, 321 .err_handler = xfrm6_tunnel_err, 322 .priority = 2, 323 }; 324 325 static int __net_init xfrm6_tunnel_net_init(struct net *net) 326 { 327 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 328 unsigned int i; 329 330 for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) 331 INIT_HLIST_HEAD(&xfrm6_tn->spi_byaddr[i]); 332 for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) 333 INIT_HLIST_HEAD(&xfrm6_tn->spi_byspi[i]); 334 xfrm6_tn->spi = 0; 335 336 return 0; 337 } 338 339 static void __net_exit xfrm6_tunnel_net_exit(struct net *net) 340 { 341 } 342 343 static struct pernet_operations xfrm6_tunnel_net_ops = { 344 .init = xfrm6_tunnel_net_init, 345 .exit = xfrm6_tunnel_net_exit, 346 .id = &xfrm6_tunnel_net_id, 347 .size = sizeof(struct xfrm6_tunnel_net), 348 }; 349 350 static int __init xfrm6_tunnel_init(void) 351 { 352 int rv; 353 354 xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi", 355 sizeof(struct xfrm6_tunnel_spi), 356 0, SLAB_HWCACHE_ALIGN, 357 NULL); 358 if (!xfrm6_tunnel_spi_kmem) 359 return -ENOMEM; 360 rv = register_pernet_subsys(&xfrm6_tunnel_net_ops); 361 if (rv < 0) 362 goto out_pernet; 363 rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6); 364 if (rv < 0) 365 goto out_type; 366 rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6); 367 if (rv < 0) 368 goto out_xfrm6; 369 rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET); 370 if (rv < 0) 371 goto out_xfrm46; 372 return 0; 373 374 out_xfrm46: 375 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6); 376 out_xfrm6: 377 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 378 out_type: 379 unregister_pernet_subsys(&xfrm6_tunnel_net_ops); 380 out_pernet: 381 kmem_cache_destroy(xfrm6_tunnel_spi_kmem); 382 return rv; 383 } 384 385 static void __exit xfrm6_tunnel_fini(void) 386 { 387 xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET); 388 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6); 389 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 390 unregister_pernet_subsys(&xfrm6_tunnel_net_ops); 391 kmem_cache_destroy(xfrm6_tunnel_spi_kmem); 392 } 393 394 module_init(xfrm6_tunnel_init); 395 module_exit(xfrm6_tunnel_fini); 396 MODULE_LICENSE("GPL"); 397 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6); 398