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 int xfrm6_tunnel_spi_hash_byaddr(const xfrm_address_t *addr) 72 { 73 unsigned int h; 74 75 h = ipv6_addr_hash((const struct in6_addr *)addr); 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 int 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, const xfrm_address_t *saddr) 89 { 90 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 91 struct xfrm6_tunnel_spi *x6spi; 92 93 hlist_for_each_entry_rcu(x6spi, 94 &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)], 95 list_byaddr) { 96 if (xfrm6_addr_equal(&x6spi->addr, saddr)) 97 return x6spi; 98 } 99 100 return NULL; 101 } 102 103 __be32 xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr) 104 { 105 struct xfrm6_tunnel_spi *x6spi; 106 u32 spi; 107 108 rcu_read_lock_bh(); 109 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr); 110 spi = x6spi ? x6spi->spi : 0; 111 rcu_read_unlock_bh(); 112 return htonl(spi); 113 } 114 115 EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup); 116 117 static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi) 118 { 119 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 120 struct xfrm6_tunnel_spi *x6spi; 121 int index = xfrm6_tunnel_spi_hash_byspi(spi); 122 123 hlist_for_each_entry(x6spi, 124 &xfrm6_tn->spi_byspi[index], 125 list_byspi) { 126 if (x6spi->spi == spi) 127 return -1; 128 } 129 return index; 130 } 131 132 static u32 __xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr) 133 { 134 struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net); 135 u32 spi; 136 struct xfrm6_tunnel_spi *x6spi; 137 int index; 138 139 if (xfrm6_tn->spi < XFRM6_TUNNEL_SPI_MIN || 140 xfrm6_tn->spi >= XFRM6_TUNNEL_SPI_MAX) 141 xfrm6_tn->spi = XFRM6_TUNNEL_SPI_MIN; 142 else 143 xfrm6_tn->spi++; 144 145 for (spi = xfrm6_tn->spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) { 146 index = __xfrm6_tunnel_spi_check(net, spi); 147 if (index >= 0) 148 goto alloc_spi; 149 } 150 for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tn->spi; spi++) { 151 index = __xfrm6_tunnel_spi_check(net, spi); 152 if (index >= 0) 153 goto alloc_spi; 154 } 155 spi = 0; 156 goto out; 157 alloc_spi: 158 xfrm6_tn->spi = spi; 159 x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, GFP_ATOMIC); 160 if (!x6spi) 161 goto out; 162 163 memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr)); 164 x6spi->spi = spi; 165 atomic_set(&x6spi->refcnt, 1); 166 167 hlist_add_head_rcu(&x6spi->list_byspi, &xfrm6_tn->spi_byspi[index]); 168 169 index = xfrm6_tunnel_spi_hash_byaddr(saddr); 170 hlist_add_head_rcu(&x6spi->list_byaddr, &xfrm6_tn->spi_byaddr[index]); 171 out: 172 return spi; 173 } 174 175 __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr) 176 { 177 struct xfrm6_tunnel_spi *x6spi; 178 u32 spi; 179 180 spin_lock_bh(&xfrm6_tunnel_spi_lock); 181 x6spi = __xfrm6_tunnel_spi_lookup(net, saddr); 182 if (x6spi) { 183 atomic_inc(&x6spi->refcnt); 184 spi = x6spi->spi; 185 } else 186 spi = __xfrm6_tunnel_alloc_spi(net, saddr); 187 spin_unlock_bh(&xfrm6_tunnel_spi_lock); 188 189 return htonl(spi); 190 } 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 (atomic_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); 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 } 345 346 static struct pernet_operations xfrm6_tunnel_net_ops = { 347 .init = xfrm6_tunnel_net_init, 348 .exit = xfrm6_tunnel_net_exit, 349 .id = &xfrm6_tunnel_net_id, 350 .size = sizeof(struct xfrm6_tunnel_net), 351 }; 352 353 static int __init xfrm6_tunnel_init(void) 354 { 355 int rv; 356 357 xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi", 358 sizeof(struct xfrm6_tunnel_spi), 359 0, SLAB_HWCACHE_ALIGN, 360 NULL); 361 if (!xfrm6_tunnel_spi_kmem) 362 return -ENOMEM; 363 rv = register_pernet_subsys(&xfrm6_tunnel_net_ops); 364 if (rv < 0) 365 goto out_pernet; 366 rv = xfrm_register_type(&xfrm6_tunnel_type, AF_INET6); 367 if (rv < 0) 368 goto out_type; 369 rv = xfrm6_tunnel_register(&xfrm6_tunnel_handler, AF_INET6); 370 if (rv < 0) 371 goto out_xfrm6; 372 rv = xfrm6_tunnel_register(&xfrm46_tunnel_handler, AF_INET); 373 if (rv < 0) 374 goto out_xfrm46; 375 return 0; 376 377 out_xfrm46: 378 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6); 379 out_xfrm6: 380 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 381 out_type: 382 unregister_pernet_subsys(&xfrm6_tunnel_net_ops); 383 out_pernet: 384 kmem_cache_destroy(xfrm6_tunnel_spi_kmem); 385 return rv; 386 } 387 388 static void __exit xfrm6_tunnel_fini(void) 389 { 390 xfrm6_tunnel_deregister(&xfrm46_tunnel_handler, AF_INET); 391 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler, AF_INET6); 392 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 393 unregister_pernet_subsys(&xfrm6_tunnel_net_ops); 394 kmem_cache_destroy(xfrm6_tunnel_spi_kmem); 395 } 396 397 module_init(xfrm6_tunnel_init); 398 module_exit(xfrm6_tunnel_fini); 399 MODULE_LICENSE("GPL"); 400 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_IPV6); 401