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/config.h> 25 #include <linux/module.h> 26 #include <linux/xfrm.h> 27 #include <linux/list.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 35 #ifdef CONFIG_IPV6_XFRM6_TUNNEL_DEBUG 36 # define X6TDEBUG 3 37 #else 38 # define X6TDEBUG 1 39 #endif 40 41 #define X6TPRINTK(fmt, args...) printk(fmt, ## args) 42 #define X6TNOPRINTK(fmt, args...) do { ; } while(0) 43 44 #if X6TDEBUG >= 1 45 # define X6TPRINTK1 X6TPRINTK 46 #else 47 # define X6TPRINTK1 X6TNOPRINTK 48 #endif 49 50 #if X6TDEBUG >= 3 51 # define X6TPRINTK3 X6TPRINTK 52 #else 53 # define X6TPRINTK3 X6TNOPRINTK 54 #endif 55 56 /* 57 * xfrm_tunnel_spi things are for allocating unique id ("spi") 58 * per xfrm_address_t. 59 */ 60 struct xfrm6_tunnel_spi { 61 struct hlist_node list_byaddr; 62 struct hlist_node list_byspi; 63 xfrm_address_t addr; 64 u32 spi; 65 atomic_t refcnt; 66 #ifdef XFRM6_TUNNEL_SPI_MAGIC 67 u32 magic; 68 #endif 69 }; 70 71 #ifdef CONFIG_IPV6_XFRM6_TUNNEL_DEBUG 72 # define XFRM6_TUNNEL_SPI_MAGIC 0xdeadbeef 73 #endif 74 75 static DEFINE_RWLOCK(xfrm6_tunnel_spi_lock); 76 77 static u32 xfrm6_tunnel_spi; 78 79 #define XFRM6_TUNNEL_SPI_MIN 1 80 #define XFRM6_TUNNEL_SPI_MAX 0xffffffff 81 82 static kmem_cache_t *xfrm6_tunnel_spi_kmem __read_mostly; 83 84 #define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256 85 #define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256 86 87 static struct hlist_head xfrm6_tunnel_spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE]; 88 static struct hlist_head xfrm6_tunnel_spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE]; 89 90 #ifdef XFRM6_TUNNEL_SPI_MAGIC 91 static int x6spi_check_magic(const struct xfrm6_tunnel_spi *x6spi, 92 const char *name) 93 { 94 if (unlikely(x6spi->magic != XFRM6_TUNNEL_SPI_MAGIC)) { 95 X6TPRINTK3(KERN_DEBUG "%s(): x6spi object " 96 "at %p has corrupted magic %08x " 97 "(should be %08x)\n", 98 name, x6spi, x6spi->magic, XFRM6_TUNNEL_SPI_MAGIC); 99 return -1; 100 } 101 return 0; 102 } 103 #else 104 static int inline x6spi_check_magic(const struct xfrm6_tunnel_spi *x6spi, 105 const char *name) 106 { 107 return 0; 108 } 109 #endif 110 111 #define X6SPI_CHECK_MAGIC(x6spi) x6spi_check_magic((x6spi), __FUNCTION__) 112 113 114 static unsigned inline xfrm6_tunnel_spi_hash_byaddr(xfrm_address_t *addr) 115 { 116 unsigned h; 117 118 X6TPRINTK3(KERN_DEBUG "%s(addr=%p)\n", __FUNCTION__, addr); 119 120 h = addr->a6[0] ^ addr->a6[1] ^ addr->a6[2] ^ addr->a6[3]; 121 h ^= h >> 16; 122 h ^= h >> 8; 123 h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1; 124 125 X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, h); 126 127 return h; 128 } 129 130 static unsigned inline xfrm6_tunnel_spi_hash_byspi(u32 spi) 131 { 132 return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE; 133 } 134 135 136 static int xfrm6_tunnel_spi_init(void) 137 { 138 int i; 139 140 X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__); 141 142 xfrm6_tunnel_spi = 0; 143 xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi", 144 sizeof(struct xfrm6_tunnel_spi), 145 0, SLAB_HWCACHE_ALIGN, 146 NULL, NULL); 147 if (!xfrm6_tunnel_spi_kmem) { 148 X6TPRINTK1(KERN_ERR 149 "%s(): failed to allocate xfrm6_tunnel_spi_kmem\n", 150 __FUNCTION__); 151 return -ENOMEM; 152 } 153 154 for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) 155 INIT_HLIST_HEAD(&xfrm6_tunnel_spi_byaddr[i]); 156 for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) 157 INIT_HLIST_HEAD(&xfrm6_tunnel_spi_byspi[i]); 158 return 0; 159 } 160 161 static void xfrm6_tunnel_spi_fini(void) 162 { 163 int i; 164 165 X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__); 166 167 for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) { 168 if (!hlist_empty(&xfrm6_tunnel_spi_byaddr[i])) 169 goto err; 170 } 171 for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) { 172 if (!hlist_empty(&xfrm6_tunnel_spi_byspi[i])) 173 goto err; 174 } 175 kmem_cache_destroy(xfrm6_tunnel_spi_kmem); 176 xfrm6_tunnel_spi_kmem = NULL; 177 return; 178 err: 179 X6TPRINTK1(KERN_ERR "%s(): table is not empty\n", __FUNCTION__); 180 return; 181 } 182 183 static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr) 184 { 185 struct xfrm6_tunnel_spi *x6spi; 186 struct hlist_node *pos; 187 188 X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr); 189 190 hlist_for_each_entry(x6spi, pos, 191 &xfrm6_tunnel_spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)], 192 list_byaddr) { 193 if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) { 194 X6SPI_CHECK_MAGIC(x6spi); 195 X6TPRINTK3(KERN_DEBUG "%s() = %p(%u)\n", __FUNCTION__, x6spi, x6spi->spi); 196 return x6spi; 197 } 198 } 199 200 X6TPRINTK3(KERN_DEBUG "%s() = NULL(0)\n", __FUNCTION__); 201 return NULL; 202 } 203 204 u32 xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr) 205 { 206 struct xfrm6_tunnel_spi *x6spi; 207 u32 spi; 208 209 X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr); 210 211 read_lock_bh(&xfrm6_tunnel_spi_lock); 212 x6spi = __xfrm6_tunnel_spi_lookup(saddr); 213 spi = x6spi ? x6spi->spi : 0; 214 read_unlock_bh(&xfrm6_tunnel_spi_lock); 215 return spi; 216 } 217 218 EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup); 219 220 static u32 __xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr) 221 { 222 u32 spi; 223 struct xfrm6_tunnel_spi *x6spi; 224 struct hlist_node *pos; 225 unsigned index; 226 227 X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr); 228 229 if (xfrm6_tunnel_spi < XFRM6_TUNNEL_SPI_MIN || 230 xfrm6_tunnel_spi >= XFRM6_TUNNEL_SPI_MAX) 231 xfrm6_tunnel_spi = XFRM6_TUNNEL_SPI_MIN; 232 else 233 xfrm6_tunnel_spi++; 234 235 for (spi = xfrm6_tunnel_spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) { 236 index = xfrm6_tunnel_spi_hash_byspi(spi); 237 hlist_for_each_entry(x6spi, pos, 238 &xfrm6_tunnel_spi_byspi[index], 239 list_byspi) { 240 if (x6spi->spi == spi) 241 goto try_next_1; 242 } 243 xfrm6_tunnel_spi = spi; 244 goto alloc_spi; 245 try_next_1:; 246 } 247 for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tunnel_spi; spi++) { 248 index = xfrm6_tunnel_spi_hash_byspi(spi); 249 hlist_for_each_entry(x6spi, pos, 250 &xfrm6_tunnel_spi_byspi[index], 251 list_byspi) { 252 if (x6spi->spi == spi) 253 goto try_next_2; 254 } 255 xfrm6_tunnel_spi = spi; 256 goto alloc_spi; 257 try_next_2:; 258 } 259 spi = 0; 260 goto out; 261 alloc_spi: 262 X6TPRINTK3(KERN_DEBUG "%s(): allocate new spi for " NIP6_FMT "\n", 263 __FUNCTION__, 264 NIP6(*(struct in6_addr *)saddr)); 265 x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, SLAB_ATOMIC); 266 if (!x6spi) { 267 X6TPRINTK1(KERN_ERR "%s(): kmem_cache_alloc() failed\n", 268 __FUNCTION__); 269 goto out; 270 } 271 #ifdef XFRM6_TUNNEL_SPI_MAGIC 272 x6spi->magic = XFRM6_TUNNEL_SPI_MAGIC; 273 #endif 274 memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr)); 275 x6spi->spi = spi; 276 atomic_set(&x6spi->refcnt, 1); 277 278 hlist_add_head(&x6spi->list_byspi, &xfrm6_tunnel_spi_byspi[index]); 279 280 index = xfrm6_tunnel_spi_hash_byaddr(saddr); 281 hlist_add_head(&x6spi->list_byaddr, &xfrm6_tunnel_spi_byaddr[index]); 282 X6SPI_CHECK_MAGIC(x6spi); 283 out: 284 X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, spi); 285 return spi; 286 } 287 288 u32 xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr) 289 { 290 struct xfrm6_tunnel_spi *x6spi; 291 u32 spi; 292 293 X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr); 294 295 write_lock_bh(&xfrm6_tunnel_spi_lock); 296 x6spi = __xfrm6_tunnel_spi_lookup(saddr); 297 if (x6spi) { 298 atomic_inc(&x6spi->refcnt); 299 spi = x6spi->spi; 300 } else 301 spi = __xfrm6_tunnel_alloc_spi(saddr); 302 write_unlock_bh(&xfrm6_tunnel_spi_lock); 303 304 X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, spi); 305 306 return spi; 307 } 308 309 EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi); 310 311 void xfrm6_tunnel_free_spi(xfrm_address_t *saddr) 312 { 313 struct xfrm6_tunnel_spi *x6spi; 314 struct hlist_node *pos, *n; 315 316 X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr); 317 318 write_lock_bh(&xfrm6_tunnel_spi_lock); 319 320 hlist_for_each_entry_safe(x6spi, pos, n, 321 &xfrm6_tunnel_spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)], 322 list_byaddr) 323 { 324 if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) { 325 X6TPRINTK3(KERN_DEBUG "%s(): x6spi object for " NIP6_FMT 326 " found at %p\n", 327 __FUNCTION__, 328 NIP6(*(struct in6_addr *)saddr), 329 x6spi); 330 X6SPI_CHECK_MAGIC(x6spi); 331 if (atomic_dec_and_test(&x6spi->refcnt)) { 332 hlist_del(&x6spi->list_byaddr); 333 hlist_del(&x6spi->list_byspi); 334 kmem_cache_free(xfrm6_tunnel_spi_kmem, x6spi); 335 break; 336 } 337 } 338 } 339 write_unlock_bh(&xfrm6_tunnel_spi_lock); 340 } 341 342 EXPORT_SYMBOL(xfrm6_tunnel_free_spi); 343 344 static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) 345 { 346 struct ipv6hdr *top_iph; 347 348 top_iph = (struct ipv6hdr *)skb->data; 349 top_iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 350 351 return 0; 352 } 353 354 static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) 355 { 356 return 0; 357 } 358 359 static int xfrm6_tunnel_rcv(struct sk_buff *skb) 360 { 361 struct ipv6hdr *iph = skb->nh.ipv6h; 362 u32 spi; 363 364 spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&iph->saddr); 365 return xfrm6_rcv_spi(skb, spi); 366 } 367 368 static int xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 369 int type, int code, int offset, __u32 info) 370 { 371 /* xfrm6_tunnel native err handling */ 372 switch (type) { 373 case ICMPV6_DEST_UNREACH: 374 switch (code) { 375 case ICMPV6_NOROUTE: 376 case ICMPV6_ADM_PROHIBITED: 377 case ICMPV6_NOT_NEIGHBOUR: 378 case ICMPV6_ADDR_UNREACH: 379 case ICMPV6_PORT_UNREACH: 380 default: 381 X6TPRINTK3(KERN_DEBUG 382 "xfrm6_tunnel: Destination Unreach.\n"); 383 break; 384 } 385 break; 386 case ICMPV6_PKT_TOOBIG: 387 X6TPRINTK3(KERN_DEBUG 388 "xfrm6_tunnel: Packet Too Big.\n"); 389 break; 390 case ICMPV6_TIME_EXCEED: 391 switch (code) { 392 case ICMPV6_EXC_HOPLIMIT: 393 X6TPRINTK3(KERN_DEBUG 394 "xfrm6_tunnel: Too small Hoplimit.\n"); 395 break; 396 case ICMPV6_EXC_FRAGTIME: 397 default: 398 break; 399 } 400 break; 401 case ICMPV6_PARAMPROB: 402 switch (code) { 403 case ICMPV6_HDR_FIELD: break; 404 case ICMPV6_UNK_NEXTHDR: break; 405 case ICMPV6_UNK_OPTION: break; 406 } 407 break; 408 default: 409 break; 410 } 411 412 return 0; 413 } 414 415 static int xfrm6_tunnel_init_state(struct xfrm_state *x) 416 { 417 if (!x->props.mode) 418 return -EINVAL; 419 420 if (x->encap) 421 return -EINVAL; 422 423 x->props.header_len = sizeof(struct ipv6hdr); 424 425 return 0; 426 } 427 428 static void xfrm6_tunnel_destroy(struct xfrm_state *x) 429 { 430 xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr); 431 } 432 433 static struct xfrm_type xfrm6_tunnel_type = { 434 .description = "IP6IP6", 435 .owner = THIS_MODULE, 436 .proto = IPPROTO_IPV6, 437 .init_state = xfrm6_tunnel_init_state, 438 .destructor = xfrm6_tunnel_destroy, 439 .input = xfrm6_tunnel_input, 440 .output = xfrm6_tunnel_output, 441 }; 442 443 static struct xfrm6_tunnel xfrm6_tunnel_handler = { 444 .handler = xfrm6_tunnel_rcv, 445 .err_handler = xfrm6_tunnel_err, 446 .priority = 2, 447 }; 448 449 static int __init xfrm6_tunnel_init(void) 450 { 451 X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__); 452 453 if (xfrm_register_type(&xfrm6_tunnel_type, AF_INET6) < 0) { 454 X6TPRINTK1(KERN_ERR 455 "xfrm6_tunnel init: can't add xfrm type\n"); 456 return -EAGAIN; 457 } 458 if (xfrm6_tunnel_register(&xfrm6_tunnel_handler)) { 459 X6TPRINTK1(KERN_ERR 460 "xfrm6_tunnel init(): can't add handler\n"); 461 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 462 return -EAGAIN; 463 } 464 if (xfrm6_tunnel_spi_init() < 0) { 465 X6TPRINTK1(KERN_ERR 466 "xfrm6_tunnel init: failed to initialize spi\n"); 467 xfrm6_tunnel_deregister(&xfrm6_tunnel_handler); 468 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 469 return -EAGAIN; 470 } 471 return 0; 472 } 473 474 static void __exit xfrm6_tunnel_fini(void) 475 { 476 X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__); 477 478 xfrm6_tunnel_spi_fini(); 479 if (xfrm6_tunnel_deregister(&xfrm6_tunnel_handler)) 480 X6TPRINTK1(KERN_ERR 481 "xfrm6_tunnel close: can't remove handler\n"); 482 if (xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6) < 0) 483 X6TPRINTK1(KERN_ERR 484 "xfrm6_tunnel close: can't remove xfrm type\n"); 485 } 486 487 module_init(xfrm6_tunnel_init); 488 module_exit(xfrm6_tunnel_fini); 489 MODULE_LICENSE("GPL"); 490