1/* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * IPv4 FIB: lookup engine and maintenance routines. 7 * 8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16#include <asm/uaccess.h> 17#include <asm/system.h> 18#include <linux/bitops.h> 19#include <linux/types.h> 20#include <linux/kernel.h> 21#include <linux/mm.h> 22#include <linux/string.h> 23#include <linux/socket.h> 24#include <linux/sockios.h> 25#include <linux/errno.h> 26#include <linux/in.h> 27#include <linux/inet.h> 28#include <linux/inetdevice.h> 29#include <linux/netdevice.h> 30#include <linux/if_arp.h> 31#include <linux/proc_fs.h> 32#include <linux/skbuff.h> 33#include <linux/netlink.h> 34#include <linux/init.h> 35#include <linux/slab.h> 36 37#include <net/net_namespace.h> 38#include <net/ip.h> 39#include <net/protocol.h> 40#include <net/route.h> 41#include <net/tcp.h> 42#include <net/sock.h> 43#include <net/ip_fib.h> 44 45#include "fib_lookup.h" 46 47static struct kmem_cache *fn_hash_kmem __read_mostly; 48static struct kmem_cache *fn_alias_kmem __read_mostly; 49 50struct fib_node { 51 struct hlist_node fn_hash; 52 struct list_head fn_alias; 53 __be32 fn_key; 54 struct fib_alias fn_embedded_alias; 55}; 56 57struct fn_zone { 58 struct fn_zone *fz_next; /* Next not empty zone */ 59 struct hlist_head *fz_hash; /* Hash table pointer */ 60 int fz_nent; /* Number of entries */ 61 62 int fz_divisor; /* Hash divisor */ 63 u32 fz_hashmask; /* (fz_divisor - 1) */ 64#define FZ_HASHMASK(fz) ((fz)->fz_hashmask) 65 66 int fz_order; /* Zone order */ 67 __be32 fz_mask; 68#define FZ_MASK(fz) ((fz)->fz_mask) 69}; 70 71/* NOTE. On fast computers evaluation of fz_hashmask and fz_mask 72 * can be cheaper than memory lookup, so that FZ_* macros are used. 73 */ 74 75struct fn_hash { 76 struct fn_zone *fn_zones[33]; 77 struct fn_zone *fn_zone_list; 78}; 79 80static inline u32 fn_hash(__be32 key, struct fn_zone *fz) 81{ 82 u32 h = ntohl(key)>>(32 - fz->fz_order); 83 h ^= (h>>20); 84 h ^= (h>>10); 85 h ^= (h>>5); 86 h &= FZ_HASHMASK(fz); 87 return h; 88} 89 90static inline __be32 fz_key(__be32 dst, struct fn_zone *fz) 91{ 92 return dst & FZ_MASK(fz); 93} 94 95static DEFINE_RWLOCK(fib_hash_lock); 96static unsigned int fib_hash_genid; 97 98#define FZ_MAX_DIVISOR ((PAGE_SIZE<<MAX_ORDER) / sizeof(struct hlist_head)) 99 100static struct hlist_head *fz_hash_alloc(int divisor) 101{ 102 unsigned long size = divisor * sizeof(struct hlist_head); 103 104 if (size <= PAGE_SIZE) { 105 return kzalloc(size, GFP_KERNEL); 106 } else { 107 return (struct hlist_head *) 108 __get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(size)); 109 } 110} 111 112/* The fib hash lock must be held when this is called. */ 113static inline void fn_rebuild_zone(struct fn_zone *fz, 114 struct hlist_head *old_ht, 115 int old_divisor) 116{ 117 int i; 118 119 for (i = 0; i < old_divisor; i++) { 120 struct hlist_node *node, *n; 121 struct fib_node *f; 122 123 hlist_for_each_entry_safe(f, node, n, &old_ht[i], fn_hash) { 124 struct hlist_head *new_head; 125 126 hlist_del(&f->fn_hash); 127 128 new_head = &fz->fz_hash[fn_hash(f->fn_key, fz)]; 129 hlist_add_head(&f->fn_hash, new_head); 130 } 131 } 132} 133 134static void fz_hash_free(struct hlist_head *hash, int divisor) 135{ 136 unsigned long size = divisor * sizeof(struct hlist_head); 137 138 if (size <= PAGE_SIZE) 139 kfree(hash); 140 else 141 free_pages((unsigned long)hash, get_order(size)); 142} 143 144static void fn_rehash_zone(struct fn_zone *fz) 145{ 146 struct hlist_head *ht, *old_ht; 147 int old_divisor, new_divisor; 148 u32 new_hashmask; 149 150 old_divisor = fz->fz_divisor; 151 152 switch (old_divisor) { 153 case 16: 154 new_divisor = 256; 155 break; 156 case 256: 157 new_divisor = 1024; 158 break; 159 default: 160 if ((old_divisor << 1) > FZ_MAX_DIVISOR) { 161 printk(KERN_CRIT "route.c: bad divisor %d!\n", old_divisor); 162 return; 163 } 164 new_divisor = (old_divisor << 1); 165 break; 166 } 167 168 new_hashmask = (new_divisor - 1); 169 170#if RT_CACHE_DEBUG >= 2 171 printk(KERN_DEBUG "fn_rehash_zone: hash for zone %d grows from %d\n", 172 fz->fz_order, old_divisor); 173#endif 174 175 ht = fz_hash_alloc(new_divisor); 176 177 if (ht) { 178 write_lock_bh(&fib_hash_lock); 179 old_ht = fz->fz_hash; 180 fz->fz_hash = ht; 181 fz->fz_hashmask = new_hashmask; 182 fz->fz_divisor = new_divisor; 183 fn_rebuild_zone(fz, old_ht, old_divisor); 184 fib_hash_genid++; 185 write_unlock_bh(&fib_hash_lock); 186 187 fz_hash_free(old_ht, old_divisor); 188 } 189} 190 191static inline void fn_free_node(struct fib_node * f) 192{ 193 kmem_cache_free(fn_hash_kmem, f); 194} 195 196static inline void fn_free_alias(struct fib_alias *fa, struct fib_node *f) 197{ 198 fib_release_info(fa->fa_info); 199 if (fa == &f->fn_embedded_alias) 200 fa->fa_info = NULL; 201 else 202 kmem_cache_free(fn_alias_kmem, fa); 203} 204 205static struct fn_zone * 206fn_new_zone(struct fn_hash *table, int z) 207{ 208 int i; 209 struct fn_zone *fz = kzalloc(sizeof(struct fn_zone), GFP_KERNEL); 210 if (!fz) 211 return NULL; 212 213 if (z) { 214 fz->fz_divisor = 16; 215 } else { 216 fz->fz_divisor = 1; 217 } 218 fz->fz_hashmask = (fz->fz_divisor - 1); 219 fz->fz_hash = fz_hash_alloc(fz->fz_divisor); 220 if (!fz->fz_hash) { 221 kfree(fz); 222 return NULL; 223 } 224 fz->fz_order = z; 225 fz->fz_mask = inet_make_mask(z); 226 227 /* Find the first not empty zone with more specific mask */ 228 for (i=z+1; i<=32; i++) 229 if (table->fn_zones[i]) 230 break; 231 write_lock_bh(&fib_hash_lock); 232 if (i>32) { 233 /* No more specific masks, we are the first. */ 234 fz->fz_next = table->fn_zone_list; 235 table->fn_zone_list = fz; 236 } else { 237 fz->fz_next = table->fn_zones[i]->fz_next; 238 table->fn_zones[i]->fz_next = fz; 239 } 240 table->fn_zones[z] = fz; 241 fib_hash_genid++; 242 write_unlock_bh(&fib_hash_lock); 243 return fz; 244} 245 246int fib_table_lookup(struct fib_table *tb, 247 const struct flowi *flp, struct fib_result *res) 248{ 249 int err; 250 struct fn_zone *fz; 251 struct fn_hash *t = (struct fn_hash *)tb->tb_data; 252 253 read_lock(&fib_hash_lock); 254 for (fz = t->fn_zone_list; fz; fz = fz->fz_next) { 255 struct hlist_head *head; 256 struct hlist_node *node; 257 struct fib_node *f; 258 __be32 k = fz_key(flp->fl4_dst, fz); 259 260 head = &fz->fz_hash[fn_hash(k, fz)]; 261 hlist_for_each_entry(f, node, head, fn_hash) { 262 if (f->fn_key != k) 263 continue; 264 265 err = fib_semantic_match(&f->fn_alias, 266 flp, res, 267 fz->fz_order); 268 if (err <= 0) 269 goto out; 270 } 271 } 272 err = 1; 273out: 274 read_unlock(&fib_hash_lock); 275 return err; 276} 277 278void fib_table_select_default(struct fib_table *tb, 279 const struct flowi *flp, struct fib_result *res) 280{ 281 int order, last_idx; 282 struct hlist_node *node; 283 struct fib_node *f; 284 struct fib_info *fi = NULL; 285 struct fib_info *last_resort; 286 struct fn_hash *t = (struct fn_hash *)tb->tb_data; 287 struct fn_zone *fz = t->fn_zones[0]; 288 289 if (fz == NULL) 290 return; 291 292 last_idx = -1; 293 last_resort = NULL; 294 order = -1; 295 296 read_lock(&fib_hash_lock); 297 hlist_for_each_entry(f, node, &fz->fz_hash[0], fn_hash) { 298 struct fib_alias *fa; 299 300 list_for_each_entry(fa, &f->fn_alias, fa_list) { 301 struct fib_info *next_fi = fa->fa_info; 302 303 if (fa->fa_scope != res->scope || 304 fa->fa_type != RTN_UNICAST) 305 continue; 306 307 if (next_fi->fib_priority > res->fi->fib_priority) 308 break; 309 if (!next_fi->fib_nh[0].nh_gw || 310 next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK) 311 continue; 312 fa->fa_state |= FA_S_ACCESSED; 313 314 if (fi == NULL) { 315 if (next_fi != res->fi) 316 break; 317 } else if (!fib_detect_death(fi, order, &last_resort, 318 &last_idx, tb->tb_default)) { 319 fib_result_assign(res, fi); 320 tb->tb_default = order; 321 goto out; 322 } 323 fi = next_fi; 324 order++; 325 } 326 } 327 328 if (order <= 0 || fi == NULL) { 329 tb->tb_default = -1; 330 goto out; 331 } 332 333 if (!fib_detect_death(fi, order, &last_resort, &last_idx, 334 tb->tb_default)) { 335 fib_result_assign(res, fi); 336 tb->tb_default = order; 337 goto out; 338 } 339 340 if (last_idx >= 0) 341 fib_result_assign(res, last_resort); 342 tb->tb_default = last_idx; 343out: 344 read_unlock(&fib_hash_lock); 345} 346 347/* Insert node F to FZ. */ 348static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f) 349{ 350 struct hlist_head *head = &fz->fz_hash[fn_hash(f->fn_key, fz)]; 351 352 hlist_add_head(&f->fn_hash, head); 353} 354 355/* Return the node in FZ matching KEY. */ 356static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key) 357{ 358 struct hlist_head *head = &fz->fz_hash[fn_hash(key, fz)]; 359 struct hlist_node *node; 360 struct fib_node *f; 361 362 hlist_for_each_entry(f, node, head, fn_hash) { 363 if (f->fn_key == key) 364 return f; 365 } 366 367 return NULL; 368} 369 370int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) 371{ 372 struct fn_hash *table = (struct fn_hash *) tb->tb_data; 373 struct fib_node *new_f = NULL; 374 struct fib_node *f; 375 struct fib_alias *fa, *new_fa; 376 struct fn_zone *fz; 377 struct fib_info *fi; 378 u8 tos = cfg->fc_tos; 379 __be32 key; 380 int err; 381 382 if (cfg->fc_dst_len > 32) 383 return -EINVAL; 384 385 fz = table->fn_zones[cfg->fc_dst_len]; 386 if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len))) 387 return -ENOBUFS; 388 389 key = 0; 390 if (cfg->fc_dst) { 391 if (cfg->fc_dst & ~FZ_MASK(fz)) 392 return -EINVAL; 393 key = fz_key(cfg->fc_dst, fz); 394 } 395 396 fi = fib_create_info(cfg); 397 if (IS_ERR(fi)) 398 return PTR_ERR(fi); 399 400 if (fz->fz_nent > (fz->fz_divisor<<1) && 401 fz->fz_divisor < FZ_MAX_DIVISOR && 402 (cfg->fc_dst_len == 32 || 403 (1 << cfg->fc_dst_len) > fz->fz_divisor)) 404 fn_rehash_zone(fz); 405 406 f = fib_find_node(fz, key); 407 408 if (!f) 409 fa = NULL; 410 else 411 fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority); 412 413 /* Now fa, if non-NULL, points to the first fib alias 414 * with the same keys [prefix,tos,priority], if such key already 415 * exists or to the node before which we will insert new one. 416 * 417 * If fa is NULL, we will need to allocate a new one and 418 * insert to the head of f. 419 * 420 * If f is NULL, no fib node matched the destination key 421 * and we need to allocate a new one of those as well. 422 */ 423 424 if (fa && fa->fa_tos == tos && 425 fa->fa_info->fib_priority == fi->fib_priority) { 426 struct fib_alias *fa_first, *fa_match; 427 428 err = -EEXIST; 429 if (cfg->fc_nlflags & NLM_F_EXCL) 430 goto out; 431 432 /* We have 2 goals: 433 * 1. Find exact match for type, scope, fib_info to avoid 434 * duplicate routes 435 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it 436 */ 437 fa_match = NULL; 438 fa_first = fa; 439 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list); 440 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) { 441 if (fa->fa_tos != tos) 442 break; 443 if (fa->fa_info->fib_priority != fi->fib_priority) 444 break; 445 if (fa->fa_type == cfg->fc_type && 446 fa->fa_scope == cfg->fc_scope && 447 fa->fa_info == fi) { 448 fa_match = fa; 449 break; 450 } 451 } 452 453 if (cfg->fc_nlflags & NLM_F_REPLACE) { 454 struct fib_info *fi_drop; 455 u8 state; 456 457 fa = fa_first; 458 if (fa_match) { 459 if (fa == fa_match) 460 err = 0; 461 goto out; 462 } 463 write_lock_bh(&fib_hash_lock); 464 fi_drop = fa->fa_info; 465 fa->fa_info = fi; 466 fa->fa_type = cfg->fc_type; 467 fa->fa_scope = cfg->fc_scope; 468 state = fa->fa_state; 469 fa->fa_state &= ~FA_S_ACCESSED; 470 fib_hash_genid++; 471 write_unlock_bh(&fib_hash_lock); 472 473 fib_release_info(fi_drop); 474 if (state & FA_S_ACCESSED) 475 rt_cache_flush(cfg->fc_nlinfo.nl_net, -1); 476 rtmsg_fib(RTM_NEWROUTE, key, fa, cfg->fc_dst_len, tb->tb_id, 477 &cfg->fc_nlinfo, NLM_F_REPLACE); 478 return 0; 479 } 480 481 /* Error if we find a perfect match which 482 * uses the same scope, type, and nexthop 483 * information. 484 */ 485 if (fa_match) 486 goto out; 487 488 if (!(cfg->fc_nlflags & NLM_F_APPEND)) 489 fa = fa_first; 490 } 491 492 err = -ENOENT; 493 if (!(cfg->fc_nlflags & NLM_F_CREATE)) 494 goto out; 495 496 err = -ENOBUFS; 497 498 if (!f) { 499 new_f = kmem_cache_zalloc(fn_hash_kmem, GFP_KERNEL); 500 if (new_f == NULL) 501 goto out; 502 503 INIT_HLIST_NODE(&new_f->fn_hash); 504 INIT_LIST_HEAD(&new_f->fn_alias); 505 new_f->fn_key = key; 506 f = new_f; 507 } 508 509 new_fa = &f->fn_embedded_alias; 510 if (new_fa->fa_info != NULL) { 511 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 512 if (new_fa == NULL) 513 goto out; 514 } 515 new_fa->fa_info = fi; 516 new_fa->fa_tos = tos; 517 new_fa->fa_type = cfg->fc_type; 518 new_fa->fa_scope = cfg->fc_scope; 519 new_fa->fa_state = 0; 520 521 /* 522 * Insert new entry to the list. 523 */ 524 525 write_lock_bh(&fib_hash_lock); 526 if (new_f) 527 fib_insert_node(fz, new_f); 528 list_add_tail(&new_fa->fa_list, 529 (fa ? &fa->fa_list : &f->fn_alias)); 530 fib_hash_genid++; 531 write_unlock_bh(&fib_hash_lock); 532 533 if (new_f) 534 fz->fz_nent++; 535 rt_cache_flush(cfg->fc_nlinfo.nl_net, -1); 536 537 rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id, 538 &cfg->fc_nlinfo, 0); 539 return 0; 540 541out: 542 if (new_f) 543 kmem_cache_free(fn_hash_kmem, new_f); 544 fib_release_info(fi); 545 return err; 546} 547 548int fib_table_delete(struct fib_table *tb, struct fib_config *cfg) 549{ 550 struct fn_hash *table = (struct fn_hash *)tb->tb_data; 551 struct fib_node *f; 552 struct fib_alias *fa, *fa_to_delete; 553 struct fn_zone *fz; 554 __be32 key; 555 556 if (cfg->fc_dst_len > 32) 557 return -EINVAL; 558 559 if ((fz = table->fn_zones[cfg->fc_dst_len]) == NULL) 560 return -ESRCH; 561 562 key = 0; 563 if (cfg->fc_dst) { 564 if (cfg->fc_dst & ~FZ_MASK(fz)) 565 return -EINVAL; 566 key = fz_key(cfg->fc_dst, fz); 567 } 568 569 f = fib_find_node(fz, key); 570 571 if (!f) 572 fa = NULL; 573 else 574 fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0); 575 if (!fa) 576 return -ESRCH; 577 578 fa_to_delete = NULL; 579 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list); 580 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) { 581 struct fib_info *fi = fa->fa_info; 582 583 if (fa->fa_tos != cfg->fc_tos) 584 break; 585 586 if ((!cfg->fc_type || 587 fa->fa_type == cfg->fc_type) && 588 (cfg->fc_scope == RT_SCOPE_NOWHERE || 589 fa->fa_scope == cfg->fc_scope) && 590 (!cfg->fc_protocol || 591 fi->fib_protocol == cfg->fc_protocol) && 592 fib_nh_match(cfg, fi) == 0) { 593 fa_to_delete = fa; 594 break; 595 } 596 } 597 598 if (fa_to_delete) { 599 int kill_fn; 600 601 fa = fa_to_delete; 602 rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len, 603 tb->tb_id, &cfg->fc_nlinfo, 0); 604 605 kill_fn = 0; 606 write_lock_bh(&fib_hash_lock); 607 list_del(&fa->fa_list); 608 if (list_empty(&f->fn_alias)) { 609 hlist_del(&f->fn_hash); 610 kill_fn = 1; 611 } 612 fib_hash_genid++; 613 write_unlock_bh(&fib_hash_lock); 614 615 if (fa->fa_state & FA_S_ACCESSED) 616 rt_cache_flush(cfg->fc_nlinfo.nl_net, -1); 617 fn_free_alias(fa, f); 618 if (kill_fn) { 619 fn_free_node(f); 620 fz->fz_nent--; 621 } 622 623 return 0; 624 } 625 return -ESRCH; 626} 627 628static int fn_flush_list(struct fn_zone *fz, int idx) 629{ 630 struct hlist_head *head = &fz->fz_hash[idx]; 631 struct hlist_node *node, *n; 632 struct fib_node *f; 633 int found = 0; 634 635 hlist_for_each_entry_safe(f, node, n, head, fn_hash) { 636 struct fib_alias *fa, *fa_node; 637 int kill_f; 638 639 kill_f = 0; 640 list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) { 641 struct fib_info *fi = fa->fa_info; 642 643 if (fi && (fi->fib_flags&RTNH_F_DEAD)) { 644 write_lock_bh(&fib_hash_lock); 645 list_del(&fa->fa_list); 646 if (list_empty(&f->fn_alias)) { 647 hlist_del(&f->fn_hash); 648 kill_f = 1; 649 } 650 fib_hash_genid++; 651 write_unlock_bh(&fib_hash_lock); 652 653 fn_free_alias(fa, f); 654 found++; 655 } 656 } 657 if (kill_f) { 658 fn_free_node(f); 659 fz->fz_nent--; 660 } 661 } 662 return found; 663} 664 665int fib_table_flush(struct fib_table *tb) 666{ 667 struct fn_hash *table = (struct fn_hash *) tb->tb_data; 668 struct fn_zone *fz; 669 int found = 0; 670 671 for (fz = table->fn_zone_list; fz; fz = fz->fz_next) { 672 int i; 673 674 for (i = fz->fz_divisor - 1; i >= 0; i--) 675 found += fn_flush_list(fz, i); 676 } 677 return found; 678} 679 680 681static inline int 682fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb, 683 struct fib_table *tb, 684 struct fn_zone *fz, 685 struct hlist_head *head) 686{ 687 struct hlist_node *node; 688 struct fib_node *f; 689 int i, s_i; 690 691 s_i = cb->args[4]; 692 i = 0; 693 hlist_for_each_entry(f, node, head, fn_hash) { 694 struct fib_alias *fa; 695 696 list_for_each_entry(fa, &f->fn_alias, fa_list) { 697 if (i < s_i) 698 goto next; 699 700 if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid, 701 cb->nlh->nlmsg_seq, 702 RTM_NEWROUTE, 703 tb->tb_id, 704 fa->fa_type, 705 fa->fa_scope, 706 f->fn_key, 707 fz->fz_order, 708 fa->fa_tos, 709 fa->fa_info, 710 NLM_F_MULTI) < 0) { 711 cb->args[4] = i; 712 return -1; 713 } 714 next: 715 i++; 716 } 717 } 718 cb->args[4] = i; 719 return skb->len; 720} 721 722static inline int 723fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb, 724 struct fib_table *tb, 725 struct fn_zone *fz) 726{ 727 int h, s_h; 728 729 if (fz->fz_hash == NULL) 730 return skb->len; 731 s_h = cb->args[3]; 732 for (h = s_h; h < fz->fz_divisor; h++) { 733 if (hlist_empty(&fz->fz_hash[h])) 734 continue; 735 if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h]) < 0) { 736 cb->args[3] = h; 737 return -1; 738 } 739 memset(&cb->args[4], 0, 740 sizeof(cb->args) - 4*sizeof(cb->args[0])); 741 } 742 cb->args[3] = h; 743 return skb->len; 744} 745 746int fib_table_dump(struct fib_table *tb, struct sk_buff *skb, 747 struct netlink_callback *cb) 748{ 749 int m, s_m; 750 struct fn_zone *fz; 751 struct fn_hash *table = (struct fn_hash *)tb->tb_data; 752 753 s_m = cb->args[2]; 754 read_lock(&fib_hash_lock); 755 for (fz = table->fn_zone_list, m=0; fz; fz = fz->fz_next, m++) { 756 if (m < s_m) continue; 757 if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) { 758 cb->args[2] = m; 759 read_unlock(&fib_hash_lock); 760 return -1; 761 } 762 memset(&cb->args[3], 0, 763 sizeof(cb->args) - 3*sizeof(cb->args[0])); 764 } 765 read_unlock(&fib_hash_lock); 766 cb->args[2] = m; 767 return skb->len; 768} 769 770void __init fib_hash_init(void) 771{ 772 fn_hash_kmem = kmem_cache_create("ip_fib_hash", sizeof(struct fib_node), 773 0, SLAB_PANIC, NULL); 774 775 fn_alias_kmem = kmem_cache_create("ip_fib_alias", sizeof(struct fib_alias), 776 0, SLAB_PANIC, NULL); 777 778} 779 780struct fib_table *fib_hash_table(u32 id) 781{ 782 struct fib_table *tb; 783 784 tb = kmalloc(sizeof(struct fib_table) + sizeof(struct fn_hash), 785 GFP_KERNEL); 786 if (tb == NULL) 787 return NULL; 788 789 tb->tb_id = id; 790 tb->tb_default = -1; 791 792 memset(tb->tb_data, 0, sizeof(struct fn_hash)); 793 return tb; 794} 795 796/* ------------------------------------------------------------------------ */ 797#ifdef CONFIG_PROC_FS 798 799struct fib_iter_state { 800 struct seq_net_private p; 801 struct fn_zone *zone; 802 int bucket; 803 struct hlist_head *hash_head; 804 struct fib_node *fn; 805 struct fib_alias *fa; 806 loff_t pos; 807 unsigned int genid; 808 int valid; 809}; 810 811static struct fib_alias *fib_get_first(struct seq_file *seq) 812{ 813 struct fib_iter_state *iter = seq->private; 814 struct fib_table *main_table; 815 struct fn_hash *table; 816 817 main_table = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN); 818 table = (struct fn_hash *)main_table->tb_data; 819 820 iter->bucket = 0; 821 iter->hash_head = NULL; 822 iter->fn = NULL; 823 iter->fa = NULL; 824 iter->pos = 0; 825 iter->genid = fib_hash_genid; 826 iter->valid = 1; 827 828 for (iter->zone = table->fn_zone_list; iter->zone; 829 iter->zone = iter->zone->fz_next) { 830 int maxslot; 831 832 if (!iter->zone->fz_nent) 833 continue; 834 835 iter->hash_head = iter->zone->fz_hash; 836 maxslot = iter->zone->fz_divisor; 837 838 for (iter->bucket = 0; iter->bucket < maxslot; 839 ++iter->bucket, ++iter->hash_head) { 840 struct hlist_node *node; 841 struct fib_node *fn; 842 843 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) { 844 struct fib_alias *fa; 845 846 list_for_each_entry(fa, &fn->fn_alias, fa_list) { 847 iter->fn = fn; 848 iter->fa = fa; 849 goto out; 850 } 851 } 852 } 853 } 854out: 855 return iter->fa; 856} 857 858static struct fib_alias *fib_get_next(struct seq_file *seq) 859{ 860 struct fib_iter_state *iter = seq->private; 861 struct fib_node *fn; 862 struct fib_alias *fa; 863 864 /* Advance FA, if any. */ 865 fn = iter->fn; 866 fa = iter->fa; 867 if (fa) { 868 BUG_ON(!fn); 869 list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) { 870 iter->fa = fa; 871 goto out; 872 } 873 } 874 875 fa = iter->fa = NULL; 876 877 /* Advance FN. */ 878 if (fn) { 879 struct hlist_node *node = &fn->fn_hash; 880 hlist_for_each_entry_continue(fn, node, fn_hash) { 881 iter->fn = fn; 882 883 list_for_each_entry(fa, &fn->fn_alias, fa_list) { 884 iter->fa = fa; 885 goto out; 886 } 887 } 888 } 889 890 fn = iter->fn = NULL; 891 892 /* Advance hash chain. */ 893 if (!iter->zone) 894 goto out; 895 896 for (;;) { 897 struct hlist_node *node; 898 int maxslot; 899 900 maxslot = iter->zone->fz_divisor; 901 902 while (++iter->bucket < maxslot) { 903 iter->hash_head++; 904 905 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) { 906 list_for_each_entry(fa, &fn->fn_alias, fa_list) { 907 iter->fn = fn; 908 iter->fa = fa; 909 goto out; 910 } 911 } 912 } 913 914 iter->zone = iter->zone->fz_next; 915 916 if (!iter->zone) 917 goto out; 918 919 iter->bucket = 0; 920 iter->hash_head = iter->zone->fz_hash; 921 922 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) { 923 list_for_each_entry(fa, &fn->fn_alias, fa_list) { 924 iter->fn = fn; 925 iter->fa = fa; 926 goto out; 927 } 928 } 929 } 930out: 931 iter->pos++; 932 return fa; 933} 934 935static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos) 936{ 937 struct fib_iter_state *iter = seq->private; 938 struct fib_alias *fa; 939 940 if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) { 941 fa = iter->fa; 942 pos -= iter->pos; 943 } else 944 fa = fib_get_first(seq); 945 946 if (fa) 947 while (pos && (fa = fib_get_next(seq))) 948 --pos; 949 return pos ? NULL : fa; 950} 951 952static void *fib_seq_start(struct seq_file *seq, loff_t *pos) 953 __acquires(fib_hash_lock) 954{ 955 void *v = NULL; 956 957 read_lock(&fib_hash_lock); 958 if (fib_get_table(seq_file_net(seq), RT_TABLE_MAIN)) 959 v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; 960 return v; 961} 962 963static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos) 964{ 965 ++*pos; 966 return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq); 967} 968 969static void fib_seq_stop(struct seq_file *seq, void *v) 970 __releases(fib_hash_lock) 971{ 972 read_unlock(&fib_hash_lock); 973} 974 975static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi) 976{ 977 static const unsigned type2flags[RTN_MAX + 1] = { 978 [7] = RTF_REJECT, [8] = RTF_REJECT, 979 }; 980 unsigned flags = type2flags[type]; 981 982 if (fi && fi->fib_nh->nh_gw) 983 flags |= RTF_GATEWAY; 984 if (mask == htonl(0xFFFFFFFF)) 985 flags |= RTF_HOST; 986 flags |= RTF_UP; 987 return flags; 988} 989 990/* 991 * This outputs /proc/net/route. 992 * 993 * It always works in backward compatibility mode. 994 * The format of the file is not supposed to be changed. 995 */ 996static int fib_seq_show(struct seq_file *seq, void *v) 997{ 998 struct fib_iter_state *iter; 999 int len; 1000 __be32 prefix, mask; 1001 unsigned flags; 1002 struct fib_node *f; 1003 struct fib_alias *fa; 1004 struct fib_info *fi; 1005 1006 if (v == SEQ_START_TOKEN) { 1007 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway " 1008 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU" 1009 "\tWindow\tIRTT"); 1010 goto out; 1011 } 1012 1013 iter = seq->private; 1014 f = iter->fn; 1015 fa = iter->fa; 1016 fi = fa->fa_info; 1017 prefix = f->fn_key; 1018 mask = FZ_MASK(iter->zone); 1019 flags = fib_flag_trans(fa->fa_type, mask, fi); 1020 if (fi) 1021 seq_printf(seq, 1022 "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n", 1023 fi->fib_dev ? fi->fib_dev->name : "*", prefix, 1024 fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority, 1025 mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0), 1026 fi->fib_window, 1027 fi->fib_rtt >> 3, &len); 1028 else 1029 seq_printf(seq, 1030 "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n", 1031 prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0, &len); 1032 1033 seq_printf(seq, "%*s\n", 127 - len, ""); 1034out: 1035 return 0; 1036} 1037 1038static const struct seq_operations fib_seq_ops = { 1039 .start = fib_seq_start, 1040 .next = fib_seq_next, 1041 .stop = fib_seq_stop, 1042 .show = fib_seq_show, 1043}; 1044 1045static int fib_seq_open(struct inode *inode, struct file *file) 1046{ 1047 return seq_open_net(inode, file, &fib_seq_ops, 1048 sizeof(struct fib_iter_state)); 1049} 1050 1051static const struct file_operations fib_seq_fops = { 1052 .owner = THIS_MODULE, 1053 .open = fib_seq_open, 1054 .read = seq_read, 1055 .llseek = seq_lseek, 1056 .release = seq_release_net, 1057}; 1058 1059int __net_init fib_proc_init(struct net *net) 1060{ 1061 if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_seq_fops)) 1062 return -ENOMEM; 1063 return 0; 1064} 1065 1066void __net_exit fib_proc_exit(struct net *net) 1067{ 1068 proc_net_remove(net, "route"); 1069} 1070#endif /* CONFIG_PROC_FS */ 1071