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ppp: allow disabling multilink protocol ID compression
[linux-2.6/x86.git] / net / ipv4 / fib_hash.c
blobb3acb0417b21f69b754003f76168f30f78b85700
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
47 static struct kmem_cache *fn_hash_kmem __read_mostly;
48 static struct kmem_cache *fn_alias_kmem __read_mostly;
49
50 struct 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
57 #define EMBEDDED_HASH_SIZE (L1_CACHE_BYTES / sizeof(struct hlist_head))
58
59 struct fn_zone {
60 struct fn_zone __rcu *fz_next; /* Next not empty zone */
61 struct hlist_head __rcu *fz_hash; /* Hash table pointer */
62 seqlock_t fz_lock;
63 u32 fz_hashmask; /* (fz_divisor - 1) */
64
65 u8 fz_order; /* Zone order (0..32) */
66 u8 fz_revorder; /* 32 - fz_order */
67 __be32 fz_mask; /* inet_make_mask(order) */
68 #define FZ_MASK(fz) ((fz)->fz_mask)
69
70 struct hlist_head fz_embedded_hash[EMBEDDED_HASH_SIZE];
71
72 int fz_nent; /* Number of entries */
73 int fz_divisor; /* Hash size (mask+1) */
74 };
75
76 struct fn_hash {
77 struct fn_zone *fn_zones[33];
78 struct fn_zone __rcu *fn_zone_list;
79 };
80
81 static inline u32 fn_hash(__be32 key, struct fn_zone *fz)
82 {
83 u32 h = ntohl(key) >> fz->fz_revorder;
84 h ^= (h>>20);
85 h ^= (h>>10);
86 h ^= (h>>5);
87 h &= fz->fz_hashmask;
88 return h;
89 }
90
91 static inline __be32 fz_key(__be32 dst, struct fn_zone *fz)
92 {
93 return dst & FZ_MASK(fz);
94 }
95
96 static unsigned int fib_hash_genid;
97
98 #define FZ_MAX_DIVISOR ((PAGE_SIZE<<MAX_ORDER) / sizeof(struct hlist_head))
99
100 static 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
107 return (struct hlist_head *)
108 __get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(size));
109 }
110
111 /* The fib hash lock must be held when this is called. */
112 static inline void fn_rebuild_zone(struct fn_zone *fz,
113 struct hlist_head *old_ht,
114 int old_divisor)
115 {
116 int i;
117
118 for (i = 0; i < old_divisor; i++) {
119 struct hlist_node *node, *n;
120 struct fib_node *f;
121
122 hlist_for_each_entry_safe(f, node, n, &old_ht[i], fn_hash) {
123 struct hlist_head *new_head;
124
125 hlist_del_rcu(&f->fn_hash);
126
127 new_head = rcu_dereference_protected(fz->fz_hash, 1) +
128 fn_hash(f->fn_key, fz);
129 hlist_add_head_rcu(&f->fn_hash, new_head);
130 }
131 }
132 }
133
134 static 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
144 static 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 new_divisor = old_divisor = fz->fz_divisor;
151
152 switch (old_divisor) {
153 case EMBEDDED_HASH_SIZE:
154 new_divisor *= EMBEDDED_HASH_SIZE;
155 break;
156 case EMBEDDED_HASH_SIZE*EMBEDDED_HASH_SIZE:
157 new_divisor *= (EMBEDDED_HASH_SIZE/2);
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 struct fn_zone nfz;
179
180 memcpy(&nfz, fz, sizeof(nfz));
181
182 write_seqlock_bh(&fz->fz_lock);
183 old_ht = rcu_dereference_protected(fz->fz_hash, 1);
184 RCU_INIT_POINTER(nfz.fz_hash, ht);
185 nfz.fz_hashmask = new_hashmask;
186 nfz.fz_divisor = new_divisor;
187 fn_rebuild_zone(&nfz, old_ht, old_divisor);
188 fib_hash_genid++;
189 rcu_assign_pointer(fz->fz_hash, ht);
190 fz->fz_hashmask = new_hashmask;
191 fz->fz_divisor = new_divisor;
192 write_sequnlock_bh(&fz->fz_lock);
193
194 if (old_ht != fz->fz_embedded_hash) {
195 synchronize_rcu();
196 fz_hash_free(old_ht, old_divisor);
197 }
198 }
199 }
200
201 static void fn_free_node_rcu(struct rcu_head *head)
202 {
203 struct fib_node *f = container_of(head, struct fib_node, fn_embedded_alias.rcu);
204
205 kmem_cache_free(fn_hash_kmem, f);
206 }
207
208 static inline void fn_free_node(struct fib_node *f)
209 {
210 call_rcu(&f->fn_embedded_alias.rcu, fn_free_node_rcu);
211 }
212
213 static void fn_free_alias_rcu(struct rcu_head *head)
214 {
215 struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
216
217 kmem_cache_free(fn_alias_kmem, fa);
218 }
219
220 static inline void fn_free_alias(struct fib_alias *fa, struct fib_node *f)
221 {
222 fib_release_info(fa->fa_info);
223 if (fa == &f->fn_embedded_alias)
224 fa->fa_info = NULL;
225 else
226 call_rcu(&fa->rcu, fn_free_alias_rcu);
227 }
228
229 static struct fn_zone *
230 fn_new_zone(struct fn_hash *table, int z)
231 {
232 int i;
233 struct fn_zone *fz = kzalloc(sizeof(struct fn_zone), GFP_KERNEL);
234 if (!fz)
235 return NULL;
236
237 seqlock_init(&fz->fz_lock);
238 fz->fz_divisor = z ? EMBEDDED_HASH_SIZE : 1;
239 fz->fz_hashmask = fz->fz_divisor - 1;
240 RCU_INIT_POINTER(fz->fz_hash, fz->fz_embedded_hash);
241 fz->fz_order = z;
242 fz->fz_revorder = 32 - z;
243 fz->fz_mask = inet_make_mask(z);
244
245 /* Find the first not empty zone with more specific mask */
246 for (i = z + 1; i <= 32; i++)
247 if (table->fn_zones[i])
248 break;
249 if (i > 32) {
250 /* No more specific masks, we are the first. */
251 rcu_assign_pointer(fz->fz_next,
252 rtnl_dereference(table->fn_zone_list));
253 rcu_assign_pointer(table->fn_zone_list, fz);
254 } else {
255 rcu_assign_pointer(fz->fz_next,
256 rtnl_dereference(table->fn_zones[i]->fz_next));
257 rcu_assign_pointer(table->fn_zones[i]->fz_next, fz);
258 }
259 table->fn_zones[z] = fz;
260 fib_hash_genid++;
261 return fz;
262 }
263
264 int fib_table_lookup(struct fib_table *tb,
265 const struct flowi *flp, struct fib_result *res,
266 int fib_flags)
267 {
268 int err;
269 struct fn_zone *fz;
270 struct fn_hash *t = (struct fn_hash *)tb->tb_data;
271
272 rcu_read_lock();
273 for (fz = rcu_dereference(t->fn_zone_list);
274 fz != NULL;
275 fz = rcu_dereference(fz->fz_next)) {
276 struct hlist_head *head;
277 struct hlist_node *node;
278 struct fib_node *f;
279 __be32 k;
280 unsigned int seq;
281
282 do {
283 seq = read_seqbegin(&fz->fz_lock);
284 k = fz_key(flp->fl4_dst, fz);
285
286 head = rcu_dereference(fz->fz_hash) + fn_hash(k, fz);
287 hlist_for_each_entry_rcu(f, node, head, fn_hash) {
288 if (f->fn_key != k)
289 continue;
290
291 err = fib_semantic_match(&f->fn_alias,
292 flp, res,
293 fz->fz_order, fib_flags);
294 if (err <= 0)
295 goto out;
296 }
297 } while (read_seqretry(&fz->fz_lock, seq));
298 }
299 err = 1;
300 out:
301 rcu_read_unlock();
302 return err;
303 }
304
305 void fib_table_select_default(struct fib_table *tb,
306 const struct flowi *flp, struct fib_result *res)
307 {
308 int order, last_idx;
309 struct hlist_node *node;
310 struct fib_node *f;
311 struct fib_info *fi = NULL;
312 struct fib_info *last_resort;
313 struct fn_hash *t = (struct fn_hash *)tb->tb_data;
314 struct fn_zone *fz = t->fn_zones[0];
315 struct hlist_head *head;
316
317 if (fz == NULL)
318 return;
319
320 last_idx = -1;
321 last_resort = NULL;
322 order = -1;
323
324 rcu_read_lock();
325 head = rcu_dereference(fz->fz_hash);
326 hlist_for_each_entry_rcu(f, node, head, fn_hash) {
327 struct fib_alias *fa;
328
329 list_for_each_entry_rcu(fa, &f->fn_alias, fa_list) {
330 struct fib_info *next_fi = fa->fa_info;
331
332 if (fa->fa_scope != res->scope ||
333 fa->fa_type != RTN_UNICAST)
334 continue;
335
336 if (next_fi->fib_priority > res->fi->fib_priority)
337 break;
338 if (!next_fi->fib_nh[0].nh_gw ||
339 next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
340 continue;
341
342 fib_alias_accessed(fa);
343
344 if (fi == NULL) {
345 if (next_fi != res->fi)
346 break;
347 } else if (!fib_detect_death(fi, order, &last_resort,
348 &last_idx, tb->tb_default)) {
349 fib_result_assign(res, fi);
350 tb->tb_default = order;
351 goto out;
352 }
353 fi = next_fi;
354 order++;
355 }
356 }
357
358 if (order <= 0 || fi == NULL) {
359 tb->tb_default = -1;
360 goto out;
361 }
362
363 if (!fib_detect_death(fi, order, &last_resort, &last_idx,
364 tb->tb_default)) {
365 fib_result_assign(res, fi);
366 tb->tb_default = order;
367 goto out;
368 }
369
370 if (last_idx >= 0)
371 fib_result_assign(res, last_resort);
372 tb->tb_default = last_idx;
373 out:
374 rcu_read_unlock();
375 }
376
377 /* Insert node F to FZ. */
378 static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
379 {
380 struct hlist_head *head = rtnl_dereference(fz->fz_hash) + fn_hash(f->fn_key, fz);
381
382 hlist_add_head_rcu(&f->fn_hash, head);
383 }
384
385 /* Return the node in FZ matching KEY. */
386 static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key)
387 {
388 struct hlist_head *head = rtnl_dereference(fz->fz_hash) + fn_hash(key, fz);
389 struct hlist_node *node;
390 struct fib_node *f;
391
392 hlist_for_each_entry_rcu(f, node, head, fn_hash) {
393 if (f->fn_key == key)
394 return f;
395 }
396
397 return NULL;
398 }
399
400
401 static struct fib_alias *fib_fast_alloc(struct fib_node *f)
402 {
403 struct fib_alias *fa = &f->fn_embedded_alias;
404
405 if (fa->fa_info != NULL)
406 fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
407 return fa;
408 }
409
410 /* Caller must hold RTNL. */
411 int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
412 {
413 struct fn_hash *table = (struct fn_hash *) tb->tb_data;
414 struct fib_node *new_f = NULL;
415 struct fib_node *f;
416 struct fib_alias *fa, *new_fa;
417 struct fn_zone *fz;
418 struct fib_info *fi;
419 u8 tos = cfg->fc_tos;
420 __be32 key;
421 int err;
422
423 if (cfg->fc_dst_len > 32)
424 return -EINVAL;
425
426 fz = table->fn_zones[cfg->fc_dst_len];
427 if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len)))
428 return -ENOBUFS;
429
430 key = 0;
431 if (cfg->fc_dst) {
432 if (cfg->fc_dst & ~FZ_MASK(fz))
433 return -EINVAL;
434 key = fz_key(cfg->fc_dst, fz);
435 }
436
437 fi = fib_create_info(cfg);
438 if (IS_ERR(fi))
439 return PTR_ERR(fi);
440
441 if (fz->fz_nent > (fz->fz_divisor<<1) &&
442 fz->fz_divisor < FZ_MAX_DIVISOR &&
443 (cfg->fc_dst_len == 32 ||
444 (1 << cfg->fc_dst_len) > fz->fz_divisor))
445 fn_rehash_zone(fz);
446
447 f = fib_find_node(fz, key);
448
449 if (!f)
450 fa = NULL;
451 else
452 fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority);
453
454 /* Now fa, if non-NULL, points to the first fib alias
455 * with the same keys [prefix,tos,priority], if such key already
456 * exists or to the node before which we will insert new one.
457 *
458 * If fa is NULL, we will need to allocate a new one and
459 * insert to the head of f.
460 *
461 * If f is NULL, no fib node matched the destination key
462 * and we need to allocate a new one of those as well.
463 */
464
465 if (fa && fa->fa_tos == tos &&
466 fa->fa_info->fib_priority == fi->fib_priority) {
467 struct fib_alias *fa_first, *fa_match;
468
469 err = -EEXIST;
470 if (cfg->fc_nlflags & NLM_F_EXCL)
471 goto out;
472
473 /* We have 2 goals:
474 * 1. Find exact match for type, scope, fib_info to avoid
475 * duplicate routes
476 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
477 */
478 fa_match = NULL;
479 fa_first = fa;
480 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
481 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
482 if (fa->fa_tos != tos)
483 break;
484 if (fa->fa_info->fib_priority != fi->fib_priority)
485 break;
486 if (fa->fa_type == cfg->fc_type &&
487 fa->fa_scope == cfg->fc_scope &&
488 fa->fa_info == fi) {
489 fa_match = fa;
490 break;
491 }
492 }
493
494 if (cfg->fc_nlflags & NLM_F_REPLACE) {
495 u8 state;
496
497 fa = fa_first;
498 if (fa_match) {
499 if (fa == fa_match)
500 err = 0;
501 goto out;
502 }
503 err = -ENOBUFS;
504 new_fa = fib_fast_alloc(f);
505 if (new_fa == NULL)
506 goto out;
507
508 new_fa->fa_tos = fa->fa_tos;
509 new_fa->fa_info = fi;
510 new_fa->fa_type = cfg->fc_type;
511 new_fa->fa_scope = cfg->fc_scope;
512 state = fa->fa_state;
513 new_fa->fa_state = state & ~FA_S_ACCESSED;
514 fib_hash_genid++;
515 list_replace_rcu(&fa->fa_list, &new_fa->fa_list);
516
517 fn_free_alias(fa, f);
518 if (state & FA_S_ACCESSED)
519 rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
520 rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len,
521 tb->tb_id, &cfg->fc_nlinfo, NLM_F_REPLACE);
522 return 0;
523 }
524
525 /* Error if we find a perfect match which
526 * uses the same scope, type, and nexthop
527 * information.
528 */
529 if (fa_match)
530 goto out;
531
532 if (!(cfg->fc_nlflags & NLM_F_APPEND))
533 fa = fa_first;
534 }
535
536 err = -ENOENT;
537 if (!(cfg->fc_nlflags & NLM_F_CREATE))
538 goto out;
539
540 err = -ENOBUFS;
541
542 if (!f) {
543 new_f = kmem_cache_zalloc(fn_hash_kmem, GFP_KERNEL);
544 if (new_f == NULL)
545 goto out;
546
547 INIT_HLIST_NODE(&new_f->fn_hash);
548 INIT_LIST_HEAD(&new_f->fn_alias);
549 new_f->fn_key = key;
550 f = new_f;
551 }
552
553 new_fa = fib_fast_alloc(f);
554 if (new_fa == NULL)
555 goto out;
556
557 new_fa->fa_info = fi;
558 new_fa->fa_tos = tos;
559 new_fa->fa_type = cfg->fc_type;
560 new_fa->fa_scope = cfg->fc_scope;
561 new_fa->fa_state = 0;
562
563 /*
564 * Insert new entry to the list.
565 */
566
567 if (new_f)
568 fib_insert_node(fz, new_f);
569 list_add_tail_rcu(&new_fa->fa_list,
570 (fa ? &fa->fa_list : &f->fn_alias));
571 fib_hash_genid++;
572
573 if (new_f)
574 fz->fz_nent++;
575 rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
576
577 rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id,
578 &cfg->fc_nlinfo, 0);
579 return 0;
580
581 out:
582 if (new_f)
583 kmem_cache_free(fn_hash_kmem, new_f);
584 fib_release_info(fi);
585 return err;
586 }
587
588 int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
589 {
590 struct fn_hash *table = (struct fn_hash *)tb->tb_data;
591 struct fib_node *f;
592 struct fib_alias *fa, *fa_to_delete;
593 struct fn_zone *fz;
594 __be32 key;
595
596 if (cfg->fc_dst_len > 32)
597 return -EINVAL;
598
599 if ((fz = table->fn_zones[cfg->fc_dst_len]) == NULL)
600 return -ESRCH;
601
602 key = 0;
603 if (cfg->fc_dst) {
604 if (cfg->fc_dst & ~FZ_MASK(fz))
605 return -EINVAL;
606 key = fz_key(cfg->fc_dst, fz);
607 }
608
609 f = fib_find_node(fz, key);
610
611 if (!f)
612 fa = NULL;
613 else
614 fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0);
615 if (!fa)
616 return -ESRCH;
617
618 fa_to_delete = NULL;
619 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
620 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
621 struct fib_info *fi = fa->fa_info;
622
623 if (fa->fa_tos != cfg->fc_tos)
624 break;
625
626 if ((!cfg->fc_type ||
627 fa->fa_type == cfg->fc_type) &&
628 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
629 fa->fa_scope == cfg->fc_scope) &&
630 (!cfg->fc_protocol ||
631 fi->fib_protocol == cfg->fc_protocol) &&
632 fib_nh_match(cfg, fi) == 0) {
633 fa_to_delete = fa;
634 break;
635 }
636 }
637
638 if (fa_to_delete) {
639 int kill_fn;
640
641 fa = fa_to_delete;
642 rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len,
643 tb->tb_id, &cfg->fc_nlinfo, 0);
644
645 kill_fn = 0;
646 list_del_rcu(&fa->fa_list);
647 if (list_empty(&f->fn_alias)) {
648 hlist_del_rcu(&f->fn_hash);
649 kill_fn = 1;
650 }
651 fib_hash_genid++;
652
653 if (fa->fa_state & FA_S_ACCESSED)
654 rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
655 fn_free_alias(fa, f);
656 if (kill_fn) {
657 fn_free_node(f);
658 fz->fz_nent--;
659 }
660
661 return 0;
662 }
663 return -ESRCH;
664 }
665
666 static int fn_flush_list(struct fn_zone *fz, int idx)
667 {
668 struct hlist_head *head = rtnl_dereference(fz->fz_hash) + idx;
669 struct hlist_node *node, *n;
670 struct fib_node *f;
671 int found = 0;
672
673 hlist_for_each_entry_safe(f, node, n, head, fn_hash) {
674 struct fib_alias *fa, *fa_node;
675 int kill_f;
676
677 kill_f = 0;
678 list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) {
679 struct fib_info *fi = fa->fa_info;
680
681 if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
682 list_del_rcu(&fa->fa_list);
683 if (list_empty(&f->fn_alias)) {
684 hlist_del_rcu(&f->fn_hash);
685 kill_f = 1;
686 }
687 fib_hash_genid++;
688
689 fn_free_alias(fa, f);
690 found++;
691 }
692 }
693 if (kill_f) {
694 fn_free_node(f);
695 fz->fz_nent--;
696 }
697 }
698 return found;
699 }
700
701 /* caller must hold RTNL. */
702 int fib_table_flush(struct fib_table *tb)
703 {
704 struct fn_hash *table = (struct fn_hash *) tb->tb_data;
705 struct fn_zone *fz;
706 int found = 0;
707
708 for (fz = rtnl_dereference(table->fn_zone_list);
709 fz != NULL;
710 fz = rtnl_dereference(fz->fz_next)) {
711 int i;
712
713 for (i = fz->fz_divisor - 1; i >= 0; i--)
714 found += fn_flush_list(fz, i);
715 }
716 return found;
717 }
718
719 void fib_free_table(struct fib_table *tb)
720 {
721 struct fn_hash *table = (struct fn_hash *) tb->tb_data;
722 struct fn_zone *fz, *next;
723
724 next = table->fn_zone_list;
725 while (next != NULL) {
726 fz = next;
727 next = fz->fz_next;
728
729 if (fz->fz_hash != fz->fz_embedded_hash)
730 fz_hash_free(fz->fz_hash, fz->fz_divisor);
731
732 kfree(fz);
733 }
734
735 kfree(tb);
736 }
737
738 static inline int
739 fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
740 struct fib_table *tb,
741 struct fn_zone *fz,
742 struct hlist_head *head)
743 {
744 struct hlist_node *node;
745 struct fib_node *f;
746 int i, s_i;
747
748 s_i = cb->args[4];
749 i = 0;
750 hlist_for_each_entry_rcu(f, node, head, fn_hash) {
751 struct fib_alias *fa;
752
753 list_for_each_entry_rcu(fa, &f->fn_alias, fa_list) {
754 if (i < s_i)
755 goto next;
756
757 if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
758 cb->nlh->nlmsg_seq,
759 RTM_NEWROUTE,
760 tb->tb_id,
761 fa->fa_type,
762 fa->fa_scope,
763 f->fn_key,
764 fz->fz_order,
765 fa->fa_tos,
766 fa->fa_info,
767 NLM_F_MULTI) < 0) {
768 cb->args[4] = i;
769 return -1;
770 }
771 next:
772 i++;
773 }
774 }
775 cb->args[4] = i;
776 return skb->len;
777 }
778
779 static inline int
780 fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
781 struct fib_table *tb,
782 struct fn_zone *fz)
783 {
784 int h, s_h;
785 struct hlist_head *head = rcu_dereference(fz->fz_hash);
786
787 if (head == NULL)
788 return skb->len;
789 s_h = cb->args[3];
790 for (h = s_h; h < fz->fz_divisor; h++) {
791 if (hlist_empty(head + h))
792 continue;
793 if (fn_hash_dump_bucket(skb, cb, tb, fz, head + h) < 0) {
794 cb->args[3] = h;
795 return -1;
796 }
797 memset(&cb->args[4], 0,
798 sizeof(cb->args) - 4*sizeof(cb->args[0]));
799 }
800 cb->args[3] = h;
801 return skb->len;
802 }
803
804 int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
805 struct netlink_callback *cb)
806 {
807 int m = 0, s_m;
808 struct fn_zone *fz;
809 struct fn_hash *table = (struct fn_hash *)tb->tb_data;
810
811 s_m = cb->args[2];
812 rcu_read_lock();
813 for (fz = rcu_dereference(table->fn_zone_list);
814 fz != NULL;
815 fz = rcu_dereference(fz->fz_next), m++) {
816 if (m < s_m)
817 continue;
818 if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
819 cb->args[2] = m;
820 rcu_read_unlock();
821 return -1;
822 }
823 memset(&cb->args[3], 0,
824 sizeof(cb->args) - 3*sizeof(cb->args[0]));
825 }
826 rcu_read_unlock();
827 cb->args[2] = m;
828 return skb->len;
829 }
830
831 void __init fib_hash_init(void)
832 {
833 fn_hash_kmem = kmem_cache_create("ip_fib_hash", sizeof(struct fib_node),
834 0, SLAB_PANIC, NULL);
835
836 fn_alias_kmem = kmem_cache_create("ip_fib_alias", sizeof(struct fib_alias),
837 0, SLAB_PANIC, NULL);
838
839 }
840
841 struct fib_table *fib_hash_table(u32 id)
842 {
843 struct fib_table *tb;
844
845 tb = kmalloc(sizeof(struct fib_table) + sizeof(struct fn_hash),
846 GFP_KERNEL);
847 if (tb == NULL)
848 return NULL;
849
850 tb->tb_id = id;
851 tb->tb_default = -1;
852
853 memset(tb->tb_data, 0, sizeof(struct fn_hash));
854 return tb;
855 }
856
857 /* ------------------------------------------------------------------------ */
858 #ifdef CONFIG_PROC_FS
859
860 struct fib_iter_state {
861 struct seq_net_private p;
862 struct fn_zone *zone;
863 int bucket;
864 struct hlist_head *hash_head;
865 struct fib_node *fn;
866 struct fib_alias *fa;
867 loff_t pos;
868 unsigned int genid;
869 int valid;
870 };
871
872 static struct fib_alias *fib_get_first(struct seq_file *seq)
873 {
874 struct fib_iter_state *iter = seq->private;
875 struct fib_table *main_table;
876 struct fn_hash *table;
877
878 main_table = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
879 table = (struct fn_hash *)main_table->tb_data;
880
881 iter->bucket = 0;
882 iter->hash_head = NULL;
883 iter->fn = NULL;
884 iter->fa = NULL;
885 iter->pos = 0;
886 iter->genid = fib_hash_genid;
887 iter->valid = 1;
888
889 for (iter->zone = rcu_dereference(table->fn_zone_list);
890 iter->zone != NULL;
891 iter->zone = rcu_dereference(iter->zone->fz_next)) {
892 int maxslot;
893
894 if (!iter->zone->fz_nent)
895 continue;
896
897 iter->hash_head = rcu_dereference(iter->zone->fz_hash);
898 maxslot = iter->zone->fz_divisor;
899
900 for (iter->bucket = 0; iter->bucket < maxslot;
901 ++iter->bucket, ++iter->hash_head) {
902 struct hlist_node *node;
903 struct fib_node *fn;
904
905 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
906 struct fib_alias *fa;
907
908 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
909 iter->fn = fn;
910 iter->fa = fa;
911 goto out;
912 }
913 }
914 }
915 }
916 out:
917 return iter->fa;
918 }
919
920 static struct fib_alias *fib_get_next(struct seq_file *seq)
921 {
922 struct fib_iter_state *iter = seq->private;
923 struct fib_node *fn;
924 struct fib_alias *fa;
925
926 /* Advance FA, if any. */
927 fn = iter->fn;
928 fa = iter->fa;
929 if (fa) {
930 BUG_ON(!fn);
931 list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) {
932 iter->fa = fa;
933 goto out;
934 }
935 }
936
937 fa = iter->fa = NULL;
938
939 /* Advance FN. */
940 if (fn) {
941 struct hlist_node *node = &fn->fn_hash;
942 hlist_for_each_entry_continue(fn, node, fn_hash) {
943 iter->fn = fn;
944
945 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
946 iter->fa = fa;
947 goto out;
948 }
949 }
950 }
951
952 fn = iter->fn = NULL;
953
954 /* Advance hash chain. */
955 if (!iter->zone)
956 goto out;
957
958 for (;;) {
959 struct hlist_node *node;
960 int maxslot;
961
962 maxslot = iter->zone->fz_divisor;
963
964 while (++iter->bucket < maxslot) {
965 iter->hash_head++;
966
967 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
968 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
969 iter->fn = fn;
970 iter->fa = fa;
971 goto out;
972 }
973 }
974 }
975
976 iter->zone = rcu_dereference(iter->zone->fz_next);
977
978 if (!iter->zone)
979 goto out;
980
981 iter->bucket = 0;
982 iter->hash_head = rcu_dereference(iter->zone->fz_hash);
983
984 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
985 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
986 iter->fn = fn;
987 iter->fa = fa;
988 goto out;
989 }
990 }
991 }
992 out:
993 iter->pos++;
994 return fa;
995 }
996
997 static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos)
998 {
999 struct fib_iter_state *iter = seq->private;
1000 struct fib_alias *fa;
1001
1002 if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) {
1003 fa = iter->fa;
1004 pos -= iter->pos;
1005 } else
1006 fa = fib_get_first(seq);
1007
1008 if (fa)
1009 while (pos && (fa = fib_get_next(seq)))
1010 --pos;
1011 return pos ? NULL : fa;
1012 }
1013
1014 static void *fib_seq_start(struct seq_file *seq, loff_t *pos)
1015 __acquires(RCU)
1016 {
1017 void *v = NULL;
1018
1019 rcu_read_lock();
1020 if (fib_get_table(seq_file_net(seq), RT_TABLE_MAIN))
1021 v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
1022 return v;
1023 }
1024
1025 static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1026 {
1027 ++*pos;
1028 return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
1029 }
1030
1031 static void fib_seq_stop(struct seq_file *seq, void *v)
1032 __releases(RCU)
1033 {
1034 rcu_read_unlock();
1035 }
1036
1037 static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
1038 {
1039 static const unsigned type2flags[RTN_MAX + 1] = {
1040 [7] = RTF_REJECT,
1041 [8] = RTF_REJECT,
1042 };
1043 unsigned flags = type2flags[type];
1044
1045 if (fi && fi->fib_nh->nh_gw)
1046 flags |= RTF_GATEWAY;
1047 if (mask == htonl(0xFFFFFFFF))
1048 flags |= RTF_HOST;
1049 flags |= RTF_UP;
1050 return flags;
1051 }
1052
1053 /*
1054 * This outputs /proc/net/route.
1055 *
1056 * It always works in backward compatibility mode.
1057 * The format of the file is not supposed to be changed.
1058 */
1059 static int fib_seq_show(struct seq_file *seq, void *v)
1060 {
1061 struct fib_iter_state *iter;
1062 int len;
1063 __be32 prefix, mask;
1064 unsigned flags;
1065 struct fib_node *f;
1066 struct fib_alias *fa;
1067 struct fib_info *fi;
1068
1069 if (v == SEQ_START_TOKEN) {
1070 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
1071 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
1072 "\tWindow\tIRTT");
1073 goto out;
1074 }
1075
1076 iter = seq->private;
1077 f = iter->fn;
1078 fa = iter->fa;
1079 fi = fa->fa_info;
1080 prefix = f->fn_key;
1081 mask = FZ_MASK(iter->zone);
1082 flags = fib_flag_trans(fa->fa_type, mask, fi);
1083 if (fi)
1084 seq_printf(seq,
1085 "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
1086 fi->fib_dev ? fi->fib_dev->name : "*", prefix,
1087 fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
1088 mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
1089 fi->fib_window,
1090 fi->fib_rtt >> 3, &len);
1091 else
1092 seq_printf(seq,
1093 "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
1094 prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0, &len);
1095
1096 seq_printf(seq, "%*s\n", 127 - len, "");
1097 out:
1098 return 0;
1099 }
1100
1101 static const struct seq_operations fib_seq_ops = {
1102 .start = fib_seq_start,
1103 .next = fib_seq_next,
1104 .stop = fib_seq_stop,
1105 .show = fib_seq_show,
1106 };
1107
1108 static int fib_seq_open(struct inode *inode, struct file *file)
1109 {
1110 return seq_open_net(inode, file, &fib_seq_ops,
1111 sizeof(struct fib_iter_state));
1112 }
1113
1114 static const struct file_operations fib_seq_fops = {
1115 .owner = THIS_MODULE,
1116 .open = fib_seq_open,
1117 .read = seq_read,
1118 .llseek = seq_lseek,
1119 .release = seq_release_net,
1120 };
1121
1122 int __net_init fib_proc_init(struct net *net)
1123 {
1124 if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_seq_fops))
1125 return -ENOMEM;
1126 return 0;
1127 }
1128
1129 void __net_exit fib_proc_exit(struct net *net)
1130 {
1131 proc_net_remove(net, "route");
1132 }
1133 #endif /* CONFIG_PROC_FS */
x86 "subsystem" repository