xfrm6_tunnel.c revision 951dbc8ac714b04c36296b8b5c36c8e036ce433f
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 <net/protocol.h> 32#include <linux/ipv6.h> 33#include <linux/icmpv6.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 */ 60struct 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 75static DEFINE_RWLOCK(xfrm6_tunnel_spi_lock); 76 77static u32 xfrm6_tunnel_spi; 78 79#define XFRM6_TUNNEL_SPI_MIN 1 80#define XFRM6_TUNNEL_SPI_MAX 0xffffffff 81 82static 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 87static struct hlist_head xfrm6_tunnel_spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE]; 88static struct hlist_head xfrm6_tunnel_spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE]; 89 90#ifdef XFRM6_TUNNEL_SPI_MAGIC 91static 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 104static 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 114static 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 130static unsigned inline xfrm6_tunnel_spi_hash_byspi(u32 spi) 131{ 132 return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE; 133} 134 135 136static 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 161static 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; 178err: 179 X6TPRINTK1(KERN_ERR "%s(): table is not empty\n", __FUNCTION__); 180 return; 181} 182 183static 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 204u32 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 218EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup); 219 220static 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; 245try_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; 257try_next_2:; 258 } 259 spi = 0; 260 goto out; 261alloc_spi: 262 X6TPRINTK3(KERN_DEBUG "%s(): allocate new spi for " 263 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n", 264 __FUNCTION__, 265 NIP6(*(struct in6_addr *)saddr)); 266 x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, SLAB_ATOMIC); 267 if (!x6spi) { 268 X6TPRINTK1(KERN_ERR "%s(): kmem_cache_alloc() failed\n", 269 __FUNCTION__); 270 goto out; 271 } 272#ifdef XFRM6_TUNNEL_SPI_MAGIC 273 x6spi->magic = XFRM6_TUNNEL_SPI_MAGIC; 274#endif 275 memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr)); 276 x6spi->spi = spi; 277 atomic_set(&x6spi->refcnt, 1); 278 279 hlist_add_head(&x6spi->list_byspi, &xfrm6_tunnel_spi_byspi[index]); 280 281 index = xfrm6_tunnel_spi_hash_byaddr(saddr); 282 hlist_add_head(&x6spi->list_byaddr, &xfrm6_tunnel_spi_byaddr[index]); 283 X6SPI_CHECK_MAGIC(x6spi); 284out: 285 X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, spi); 286 return spi; 287} 288 289u32 xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr) 290{ 291 struct xfrm6_tunnel_spi *x6spi; 292 u32 spi; 293 294 X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr); 295 296 write_lock_bh(&xfrm6_tunnel_spi_lock); 297 x6spi = __xfrm6_tunnel_spi_lookup(saddr); 298 if (x6spi) { 299 atomic_inc(&x6spi->refcnt); 300 spi = x6spi->spi; 301 } else 302 spi = __xfrm6_tunnel_alloc_spi(saddr); 303 write_unlock_bh(&xfrm6_tunnel_spi_lock); 304 305 X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, spi); 306 307 return spi; 308} 309 310EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi); 311 312void xfrm6_tunnel_free_spi(xfrm_address_t *saddr) 313{ 314 struct xfrm6_tunnel_spi *x6spi; 315 struct hlist_node *pos, *n; 316 317 X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr); 318 319 write_lock_bh(&xfrm6_tunnel_spi_lock); 320 321 hlist_for_each_entry_safe(x6spi, pos, n, 322 &xfrm6_tunnel_spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)], 323 list_byaddr) 324 { 325 if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) { 326 X6TPRINTK3(KERN_DEBUG "%s(): x6spi object " 327 "for %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x " 328 "found at %p\n", 329 __FUNCTION__, 330 NIP6(*(struct in6_addr *)saddr), 331 x6spi); 332 X6SPI_CHECK_MAGIC(x6spi); 333 if (atomic_dec_and_test(&x6spi->refcnt)) { 334 hlist_del(&x6spi->list_byaddr); 335 hlist_del(&x6spi->list_byspi); 336 kmem_cache_free(xfrm6_tunnel_spi_kmem, x6spi); 337 break; 338 } 339 } 340 } 341 write_unlock_bh(&xfrm6_tunnel_spi_lock); 342} 343 344EXPORT_SYMBOL(xfrm6_tunnel_free_spi); 345 346static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) 347{ 348 struct ipv6hdr *top_iph; 349 350 top_iph = (struct ipv6hdr *)skb->data; 351 top_iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 352 353 return 0; 354} 355 356static int xfrm6_tunnel_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb) 357{ 358 return 0; 359} 360 361static struct xfrm6_tunnel *xfrm6_tunnel_handler; 362static DECLARE_MUTEX(xfrm6_tunnel_sem); 363 364int xfrm6_tunnel_register(struct xfrm6_tunnel *handler) 365{ 366 int ret; 367 368 down(&xfrm6_tunnel_sem); 369 ret = 0; 370 if (xfrm6_tunnel_handler != NULL) 371 ret = -EINVAL; 372 if (!ret) 373 xfrm6_tunnel_handler = handler; 374 up(&xfrm6_tunnel_sem); 375 376 return ret; 377} 378 379EXPORT_SYMBOL(xfrm6_tunnel_register); 380 381int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler) 382{ 383 int ret; 384 385 down(&xfrm6_tunnel_sem); 386 ret = 0; 387 if (xfrm6_tunnel_handler != handler) 388 ret = -EINVAL; 389 if (!ret) 390 xfrm6_tunnel_handler = NULL; 391 up(&xfrm6_tunnel_sem); 392 393 synchronize_net(); 394 395 return ret; 396} 397 398EXPORT_SYMBOL(xfrm6_tunnel_deregister); 399 400static int xfrm6_tunnel_rcv(struct sk_buff **pskb) 401{ 402 struct sk_buff *skb = *pskb; 403 struct xfrm6_tunnel *handler = xfrm6_tunnel_handler; 404 struct ipv6hdr *iph = skb->nh.ipv6h; 405 u32 spi; 406 407 /* device-like_ip6ip6_handler() */ 408 if (handler && handler->handler(pskb) == 0) 409 return 0; 410 411 spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&iph->saddr); 412 return xfrm6_rcv_spi(pskb, spi); 413} 414 415static void xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 416 int type, int code, int offset, __u32 info) 417{ 418 struct xfrm6_tunnel *handler = xfrm6_tunnel_handler; 419 420 /* call here first for device-like ip6ip6 err handling */ 421 if (handler) { 422 handler->err_handler(skb, opt, type, code, offset, info); 423 return; 424 } 425 426 /* xfrm6_tunnel native err handling */ 427 switch (type) { 428 case ICMPV6_DEST_UNREACH: 429 switch (code) { 430 case ICMPV6_NOROUTE: 431 case ICMPV6_ADM_PROHIBITED: 432 case ICMPV6_NOT_NEIGHBOUR: 433 case ICMPV6_ADDR_UNREACH: 434 case ICMPV6_PORT_UNREACH: 435 default: 436 X6TPRINTK3(KERN_DEBUG 437 "xfrm6_tunnel: Destination Unreach.\n"); 438 break; 439 } 440 break; 441 case ICMPV6_PKT_TOOBIG: 442 X6TPRINTK3(KERN_DEBUG 443 "xfrm6_tunnel: Packet Too Big.\n"); 444 break; 445 case ICMPV6_TIME_EXCEED: 446 switch (code) { 447 case ICMPV6_EXC_HOPLIMIT: 448 X6TPRINTK3(KERN_DEBUG 449 "xfrm6_tunnel: Too small Hoplimit.\n"); 450 break; 451 case ICMPV6_EXC_FRAGTIME: 452 default: 453 break; 454 } 455 break; 456 case ICMPV6_PARAMPROB: 457 switch (code) { 458 case ICMPV6_HDR_FIELD: break; 459 case ICMPV6_UNK_NEXTHDR: break; 460 case ICMPV6_UNK_OPTION: break; 461 } 462 break; 463 default: 464 break; 465 } 466 return; 467} 468 469static int xfrm6_tunnel_init_state(struct xfrm_state *x) 470{ 471 if (!x->props.mode) 472 return -EINVAL; 473 474 if (x->encap) 475 return -EINVAL; 476 477 x->props.header_len = sizeof(struct ipv6hdr); 478 479 return 0; 480} 481 482static void xfrm6_tunnel_destroy(struct xfrm_state *x) 483{ 484 xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr); 485} 486 487static struct xfrm_type xfrm6_tunnel_type = { 488 .description = "IP6IP6", 489 .owner = THIS_MODULE, 490 .proto = IPPROTO_IPV6, 491 .init_state = xfrm6_tunnel_init_state, 492 .destructor = xfrm6_tunnel_destroy, 493 .input = xfrm6_tunnel_input, 494 .output = xfrm6_tunnel_output, 495}; 496 497static struct inet6_protocol xfrm6_tunnel_protocol = { 498 .handler = xfrm6_tunnel_rcv, 499 .err_handler = xfrm6_tunnel_err, 500 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 501}; 502 503static int __init xfrm6_tunnel_init(void) 504{ 505 X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__); 506 507 if (xfrm_register_type(&xfrm6_tunnel_type, AF_INET6) < 0) { 508 X6TPRINTK1(KERN_ERR 509 "xfrm6_tunnel init: can't add xfrm type\n"); 510 return -EAGAIN; 511 } 512 if (inet6_add_protocol(&xfrm6_tunnel_protocol, IPPROTO_IPV6) < 0) { 513 X6TPRINTK1(KERN_ERR 514 "xfrm6_tunnel init(): can't add protocol\n"); 515 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 516 return -EAGAIN; 517 } 518 if (xfrm6_tunnel_spi_init() < 0) { 519 X6TPRINTK1(KERN_ERR 520 "xfrm6_tunnel init: failed to initialize spi\n"); 521 inet6_del_protocol(&xfrm6_tunnel_protocol, IPPROTO_IPV6); 522 xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6); 523 return -EAGAIN; 524 } 525 return 0; 526} 527 528static void __exit xfrm6_tunnel_fini(void) 529{ 530 X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__); 531 532 xfrm6_tunnel_spi_fini(); 533 if (inet6_del_protocol(&xfrm6_tunnel_protocol, IPPROTO_IPV6) < 0) 534 X6TPRINTK1(KERN_ERR 535 "xfrm6_tunnel close: can't remove protocol\n"); 536 if (xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6) < 0) 537 X6TPRINTK1(KERN_ERR 538 "xfrm6_tunnel close: can't remove xfrm type\n"); 539} 540 541module_init(xfrm6_tunnel_init); 542module_exit(xfrm6_tunnel_fini); 543MODULE_LICENSE("GPL"); 544