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 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 atomic_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 } 113 114 EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup); 115 116 static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi) 117 { 118 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 119 struct xfrm6_tunnel_spi *x6spi; 120 int index = xfrm6_tunnel_spi_hash_byspi(spi); 121 122 hlist_for_each_entry(x6spi, 123 &xfrm6_tn->spi_byspi[index], 124 list_byspi) { 125 if (x6spi->spi == spi) 126 return -1; 127 } 128 return index; 129 } 130 131 static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr) 132 { 133 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 134 u32 spi; 135 struct xfrm6_tunnel_spi *x6spi; 136 int index; 137 138 if (xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN || 139 xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX) 140 xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN; 141 else 142 xfrm6_tn->spi++; 143 144 for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) { 145 index = __xfrm6_tunnel_spi_check(net, spi); 146 if (index >= 0) 147 goto alloc_spi; 148 } 149 for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) { 150 index = __xfrm6_tunnel_spi_check(net, spi); 151 if (index >= 0) 152 goto alloc_spi; 153 } 154 spi = 0; 155 goto out; 156 alloc_spi: 157 xfrm6_tn->spi = spi; 158 x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC); 159 if (!x6spi) 160 goto out; 161 162 memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr)); 163 x6spi->spi = spi; 164 atomic_set(&x6spi->refcnt, 1); 165 166 hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]); 167 168 index = xfrm6_tunnel_spi_hash_byaddr(saddr); 169 hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]); 170 out: 171 return spi; 172 } 173 174 __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr) 175 { 176 struct xfrm6_tunnel_spi *x6spi; 177 u32 spi; 178 179 spin_lock_bh(&xfrm6_tunnel_spi_lock); 180 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr); 181 if (x6spi) { 182 atomic_inc(&x6spi->refcnt); 183 spi = x6spi->spi; 184 } else 185 spi = __xfrm6_tunnel_alloc_spi(net, saddr); 186 spin_unlock_bh(&xfrm6_tunnel_spi_lock); 187 188 return htonl(spi); 189 } 190 191 EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi); 192 193 static void x6spi_destroy_rcu(struct rcu_head *head) 194 { 195 kmem_cache_free(xfrm6_tunnel_spi_kmem, 196 container_of(head, struct xfrm6_tunnel_spi, rcu_head)); 197 } 198 199 static void xfrm6_tunnel_free_spi(struct net *net, xfrm_address_t *saddr) 200 { 201 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 202 struct xfrm6_tunnel_spi *x6spi; 203 struct hlist_node *n; 204 205 spin_lock_bh(&xfrm6_tunnel_spi_lock); 206 207 hlist_for_each_entry_safe(x6spi, n, 208 &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)], 209 list_byaddr) 210 { 211 if (xfrm6_addr_equal(&x6spi->addr, saddr)) { 212 if (atomic_dec_and_test(&x6spi->refcnt)) { 213 hlist_del_rcu(&x6spi->list_byaddr); 214 hlist_del_rcu(&x6spi->list_byspi); 215 call_rcu(&x6spi->rcu_head, x6spi_destroy_rcu); 216 break; 217 } 218 } 219 } 220 spin_unlock_bh(&xfrm6_tunnel_spi_lock); 221 } 222 223 static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) 224 { 225 skb_push(skb, -skb_network_offset(skb)); 226 return 0; 227 } 228 229 static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) 230 { 231 return skb_network_header(skb)[IP6CB(skb)->nhoff]; 232 } 233 234 static int xfrm6_tunnel_rcv(struct sk_buff *skb) 235 { 236 struct net *net = dev_net(skb->dev); 237 const struct ipv6hdr *iph = ipv6_hdr(skb); 238 __be32 spi; 239 240 spi = xfrm6_tunnel_spi_lookup(net, (const xfrm_address_t *)&iph->saddr); 241 return xfrm6_rcv_spi(skb, IPPROTO_IPV6, spi); 242 } 243 244 static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 245 u8 type, u8 code, int offset, __be32 info) 246 { 247 /* xfrm6_tunnel native err handling */ 248 switch (type) { 249 case ICMPV6_DEST_UNREACH: 250 switch (code) { 251 case ICMPV6_NOROUTE: 252 case ICMPV6_ADM_PROHIBITED: 253 case ICMPV6_NOT_NEIGHBOUR: 254 case ICMPV6_ADDR_UNREACH: 255 case ICMPV6_PORT_UNREACH: 256 default: 257 break; 258 } 259 break; 260 case ICMPV6_PKT_TOOBIG: 261 break; 262 case ICMPV6_TIME_EXCEED: 263 switch (code) { 264 case ICMPV6_EXC_HOPLIMIT: 265 break; 266 case ICMPV6_EXC_FRAGTIME: 267 default: 268 break; 269 } 270 break; 271 case ICMPV6_PARAMPROB: 272 switch (code) { 273 case ICMPV6_HDR_FIELD: break; 274 case ICMPV6_UNK_NEXTHDR: break; 275 case ICMPV6_UNK_OPTION: break; 276 } 277 break; 278 default: 279 break; 280 } 281 282 return 0; 283 } 284 285 static int xfrm6_tunnel_init_state(struct xfrm_state *x) 286 { 287 if (x->props.mode != XFRM_MODE_TUNNEL) 288 return -EINVAL; 289 290 if (x->encap) 291 return -EINVAL; 292 293 x->props.header_len = sizeof(struct ipv6hdr); 294 295 return 0; 296 } 297 298 static void xfrm6_tunnel_destroy(struct xfrm_state *x) 299 { 300 struct net *net = xs_net(x); 301 302 xfrm6_tunnel_free_spi(net, (xfrm_address_t *)&x->props.saddr); 303 } 304 305 static const struct xfrm_type xfrm6_tunnel_type = { 306 .description = "IP6IP6", 307 .owner = THIS_MODULE, 308 .proto = IPPROTO_IPV6, 309 .init_state = xfrm6_tunnel_init_state, 310 .destructor = xfrm6_tunnel_destroy, 311 .input = xfrm6_tunnel_input, 312 .output = xfrm6_tunnel_output, 313 }; 314 315 static struct xfrm6_tunnel xfrm6_tunnel_handler __read_mostly = { 316 .handler = xfrm6_tunnel_rcv, 317 .err_handler = xfrm6_tunnel_err, 318 .priority = 2, 319 }; 320 321 static struct xfrm6_tunnel xfrm46_tunnel_handler __read_mostly = { 322 .handler = xfrm6_tunnel_rcv, 323 .err_handler = xfrm6_tunnel_err, 324 .priority = 2, 325 }; 326 327 static int __net_init xfrm6_tunnel_net_init(struct net *net) 328 { 329 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 330 unsigned int i; 331 332 for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) 333 INIT_HLIST_HEAD(&xfrm6_tn->spi_byaddr[i]); 334 for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) 335 INIT_HLIST_HEAD(&xfrm6_tn->spi_byspi[i]); 336 xfrm6_tn->spi = 0; 337 338 return 0; 339 } 340 341 static void __net_exit xfrm6_tunnel_net_exit(struct net *net) 342 { 343 } 344 345 static struct pernet_operations xfrm6_tunnel_net_ops = { 346 .init = xfrm6_tunnel_net_init, 347 .exit = xfrm6_tunnel_net_exit, 348 .id = &xfrm6_tunnel_net_id, 349 .size = sizeof(struct xfrm6_tunnel_net), 350 }; 351 352 static int __init xfrm6_tunnel_init(void) 353 { 354 int rv; 355 356 xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi", 357 sizeof(struct xfrm6_tunnel_spi), 358 0, SLAB_HWCACHE_ALIGN, 359 NULL); 360 if (!xfrm6_tunnel_spi_kmem) 361 return -ENOMEM; 362 rv = register_pernet_subsys(&xfrm6_tunnel_net_ops); 363 if (rv < 0) 364 goto out_pernet; 365 rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6); 366 if (rv < 0) 367 goto out_type; 368 rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6); 369 if (rv < 0) 370 goto out_xfrm6; 371 rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET); 372 if (rv < 0) 373 goto out_xfrm46; 374 return 0; 375 376 out_xfrm46: 377 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6); 378 out_xfrm6: 379 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 380 out_type: 381 unregister_pernet_subsys(&xfrm6_tunnel_net_ops); 382 out_pernet: 383 kmem_cache_destroy(xfrm6_tunnel_spi_kmem); 384 return rv; 385 } 386 387 static void __exit xfrm6_tunnel_fini(void) 388 { 389 xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET); 390 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6); 391 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 392 unregister_pernet_subsys(&xfrm6_tunnel_net_ops); 393 kmem_cache_destroy(xfrm6_tunnel_spi_kmem); 394 } 395 396 module_init(xfrm6_tunnel_init); 397 module_exit(xfrm6_tunnel_fini); 398 MODULE_LICENSE("GPL"); 399 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6); 400