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 if (spi == XFRM6_TUNNEL_SPI_MAX) 149 break; 150 } 151 for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) { 152 index = __xfrm6_tunnel_spi_check(net, spi); 153 if (index >= 0) 154 goto alloc_spi; 155 } 156 spi = 0; 157 goto out; 158 alloc_spi: 159 xfrm6_tn->spi = spi; 160 x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC); 161 if (!x6spi) 162 goto out; 163 164 memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr)); 165 x6spi->spi = spi; 166 refcount_set(&x6spi->refcnt, 1); 167 168 hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]); 169 170 index = xfrm6_tunnel_spi_hash_byaddr(saddr); 171 hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]); 172 out: 173 return spi; 174 } 175 176 __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr) 177 { 178 struct xfrm6_tunnel_spi *x6spi; 179 u32 spi; 180 181 spin_lock_bh(&xfrm6_tunnel_spi_lock); 182 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr); 183 if (x6spi) { 184 refcount_inc(&x6spi->refcnt); 185 spi = x6spi->spi; 186 } else 187 spi = __xfrm6_tunnel_alloc_spi(net, saddr); 188 spin_unlock_bh(&xfrm6_tunnel_spi_lock); 189 190 return htonl(spi); 191 } 192 EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi); 193 194 static void x6spi_destroy_rcu(struct rcu_head *head) 195 { 196 kmem_cache_free(xfrm6_tunnel_spi_kmem, 197 container_of(head, struct xfrm6_tunnel_spi, rcu_head)); 198 } 199 200 static void xfrm6_tunnel_free_spi(struct net *net, xfrm_address_t *saddr) 201 { 202 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 203 struct xfrm6_tunnel_spi *x6spi; 204 struct hlist_node *n; 205 206 spin_lock_bh(&xfrm6_tunnel_spi_lock); 207 208 hlist_for_each_entry_safe(x6spi, n, 209 &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)], 210 list_byaddr) 211 { 212 if (xfrm6_addr_equal(&x6spi->addr, saddr)) { 213 if (refcount_dec_and_test(&x6spi->refcnt)) { 214 hlist_del_rcu(&x6spi->list_byaddr); 215 hlist_del_rcu(&x6spi->list_byspi); 216 call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu); 217 break; 218 } 219 } 220 } 221 spin_unlock_bh(&xfrm6_tunnel_spi_lock); 222 } 223 224 static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) 225 { 226 skb_push(skb, -skb_network_offset(skb)); 227 return 0; 228 } 229 230 static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) 231 { 232 return skb_network_header(skb)[IP6CB(skb)->nhoff]; 233 } 234 235 static int xfrm6_tunnel_rcv(struct sk_buff *skb) 236 { 237 struct net *net = dev_net(skb->dev); 238 const struct ipv6hdr *iph = ipv6_hdr(skb); 239 __be32 spi; 240 241 spi = xfrm6_tunnel_spi_lookup(net, (const xfrm_address_t *)&iph->saddr); 242 return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi, NULL); 243 } 244 245 static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 246 u8 type, u8 code, int offset, __be32 info) 247 { 248 /* xfrm6_tunnel native err handling */ 249 switch (type) { 250 case ICMPV6_DEST_UNREACH: 251 switch (code) { 252 case ICMPV6_NOROUTE: 253 case ICMPV6_ADM_PROHIBITED: 254 case ICMPV6_NOT_NEIGHBOUR: 255 case ICMPV6_ADDR_UNREACH: 256 case ICMPV6_PORT_UNREACH: 257 default: 258 break; 259 } 260 break; 261 case ICMPV6_PKT_TOOBIG: 262 break; 263 case ICMPV6_TIME_EXCEED: 264 switch (code) { 265 case ICMPV6_EXC_HOPLIMIT: 266 break; 267 case ICMPV6_EXC_FRAGTIME: 268 default: 269 break; 270 } 271 break; 272 case ICMPV6_PARAMPROB: 273 switch (code) { 274 case ICMPV6_HDR_FIELD: break; 275 case ICMPV6_UNK_NEXTHDR: break; 276 case ICMPV6_UNK_OPTION: break; 277 } 278 break; 279 default: 280 break; 281 } 282 283 return 0; 284 } 285 286 static int xfrm6_tunnel_init_state(struct xfrm_state *x) 287 { 288 if (x->props.mode != XFRM_MODE_TUNNEL) 289 return -EINVAL; 290 291 if (x->encap) 292 return -EINVAL; 293 294 x->props.header_len = sizeof(struct ipv6hdr); 295 296 return 0; 297 } 298 299 static void xfrm6_tunnel_destroy(struct xfrm_state *x) 300 { 301 struct net *net = xs_net(x); 302 303 xfrm6_tunnel_free_spi(net, (xfrm_address_t *)&x->props.saddr); 304 } 305 306 static const struct xfrm_type xfrm6_tunnel_type = { 307 .description = "IP6IP6", 308 .owner = THIS_MODULE, 309 .proto = IPPROTO_IPV6, 310 .init_state = xfrm6_tunnel_init_state, 311 .destructor = xfrm6_tunnel_destroy, 312 .input = xfrm6_tunnel_input, 313 .output = xfrm6_tunnel_output, 314 }; 315 316 static struct xfrm6_tunnel xfrm6_tunnel_handler __read_mostly = { 317 .handler = xfrm6_tunnel_rcv, 318 .err_handler = xfrm6_tunnel_err, 319 .priority = 2, 320 }; 321 322 static struct xfrm6_tunnel xfrm46_tunnel_handler __read_mostly = { 323 .handler = xfrm6_tunnel_rcv, 324 .err_handler = xfrm6_tunnel_err, 325 .priority = 2, 326 }; 327 328 static int __net_init xfrm6_tunnel_net_init(struct net *net) 329 { 330 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 331 unsigned int i; 332 333 for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) 334 INIT_HLIST_HEAD(&xfrm6_tn->spi_byaddr[i]); 335 for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) 336 INIT_HLIST_HEAD(&xfrm6_tn->spi_byspi[i]); 337 xfrm6_tn->spi = 0; 338 339 return 0; 340 } 341 342 static void __net_exit xfrm6_tunnel_net_exit(struct net *net) 343 { 344 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 345 unsigned int i; 346 347 xfrm_flush_gc(); 348 xfrm_state_flush(net, 0, false, true); 349 350 for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) 351 WARN_ON_ONCE(!hlist_empty(&xfrm6_tn->spi_byaddr[i])); 352 353 for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) 354 WARN_ON_ONCE(!hlist_empty(&xfrm6_tn->spi_byspi[i])); 355 } 356 357 static struct pernet_operations xfrm6_tunnel_net_ops = { 358 .init = xfrm6_tunnel_net_init, 359 .exit = xfrm6_tunnel_net_exit, 360 .id = &xfrm6_tunnel_net_id, 361 .size = sizeof(struct xfrm6_tunnel_net), 362 }; 363 364 static int __init xfrm6_tunnel_init(void) 365 { 366 int rv; 367 368 xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi", 369 sizeof(struct xfrm6_tunnel_spi), 370 0, SLAB_HWCACHE_ALIGN, 371 NULL); 372 if (!xfrm6_tunnel_spi_kmem) 373 return -ENOMEM; 374 rv = register_pernet_subsys(&xfrm6_tunnel_net_ops); 375 if (rv < 0) 376 goto out_pernet; 377 rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6); 378 if (rv < 0) 379 goto out_type; 380 rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6); 381 if (rv < 0) 382 goto out_xfrm6; 383 rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET); 384 if (rv < 0) 385 goto out_xfrm46; 386 return 0; 387 388 out_xfrm46: 389 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6); 390 out_xfrm6: 391 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 392 out_type: 393 unregister_pernet_subsys(&xfrm6_tunnel_net_ops); 394 out_pernet: 395 kmem_cache_destroy(xfrm6_tunnel_spi_kmem); 396 return rv; 397 } 398 399 static void __exit xfrm6_tunnel_fini(void) 400 { 401 xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET); 402 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6); 403 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 404 unregister_pernet_subsys(&xfrm6_tunnel_net_ops); 405 /* Someone maybe has gotten the xfrm6_tunnel_spi. 406 * So need to wait it. 407 */ 408 rcu_barrier(); 409 kmem_cache_destroy(xfrm6_tunnel_spi_kmem); 410 } 411 412 module_init(xfrm6_tunnel_init); 413 module_exit(xfrm6_tunnel_fini); 414 MODULE_LICENSE("GPL"); 415 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6); 416