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[UDP]: Make full use of proto.h.udp_hash innovation.
[deliverable/linux.git] / net / ipv4 / fib_hash.c
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 * Version: $Id: fib_hash.c,v 1.13 2001/10/31 21:55:54 davem Exp $
9 *
10 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17
18 #include <asm/uaccess.h>
19 #include <asm/system.h>
20 #include <linux/bitops.h>
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/mm.h>
24 #include <linux/string.h>
25 #include <linux/socket.h>
26 #include <linux/sockios.h>
27 #include <linux/errno.h>
28 #include <linux/in.h>
29 #include <linux/inet.h>
30 #include <linux/inetdevice.h>
31 #include <linux/netdevice.h>
32 #include <linux/if_arp.h>
33 #include <linux/proc_fs.h>
34 #include <linux/skbuff.h>
35 #include <linux/netlink.h>
36 #include <linux/init.h>
37
38 #include <net/net_namespace.h>
39 #include <net/ip.h>
40 #include <net/protocol.h>
41 #include <net/route.h>
42 #include <net/tcp.h>
43 #include <net/sock.h>
44 #include <net/ip_fib.h>
45
46 #include "fib_lookup.h"
47
48 static struct kmem_cache *fn_hash_kmem __read_mostly;
49 static struct kmem_cache *fn_alias_kmem __read_mostly;
50
51 struct fib_node {
52 struct hlist_node fn_hash;
53 struct list_head fn_alias;
54 __be32 fn_key;
55 struct fib_alias fn_embedded_alias;
56 };
57
58 struct fn_zone {
59 struct fn_zone *fz_next; /* Next not empty zone */
60 struct hlist_head *fz_hash; /* Hash table pointer */
61 int fz_nent; /* Number of entries */
62
63 int fz_divisor; /* Hash divisor */
64 u32 fz_hashmask; /* (fz_divisor - 1) */
65 #define FZ_HASHMASK(fz) ((fz)->fz_hashmask)
66
67 int fz_order; /* Zone order */
68 __be32 fz_mask;
69 #define FZ_MASK(fz) ((fz)->fz_mask)
70 };
71
72 /* NOTE. On fast computers evaluation of fz_hashmask and fz_mask
73 * can be cheaper than memory lookup, so that FZ_* macros are used.
74 */
75
76 struct fn_hash {
77 struct fn_zone *fn_zones[33];
78 struct fn_zone *fn_zone_list;
79 };
80
81 static inline u32 fn_hash(__be32 key, struct fn_zone *fz)
82 {
83 u32 h = ntohl(key)>>(32 - fz->fz_order);
84 h ^= (h>>20);
85 h ^= (h>>10);
86 h ^= (h>>5);
87 h &= FZ_HASHMASK(fz);
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 DEFINE_RWLOCK(fib_hash_lock);
97 static unsigned int fib_hash_genid;
98
99 #define FZ_MAX_DIVISOR ((PAGE_SIZE<<MAX_ORDER) / sizeof(struct hlist_head))
100
101 static struct hlist_head *fz_hash_alloc(int divisor)
102 {
103 unsigned long size = divisor * sizeof(struct hlist_head);
104
105 if (size <= PAGE_SIZE) {
106 return kzalloc(size, GFP_KERNEL);
107 } else {
108 return (struct hlist_head *)
109 __get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(size));
110 }
111 }
112
113 /* The fib hash lock must be held when this is called. */
114 static inline void fn_rebuild_zone(struct fn_zone *fz,
115 struct hlist_head *old_ht,
116 int old_divisor)
117 {
118 int i;
119
120 for (i = 0; i < old_divisor; i++) {
121 struct hlist_node *node, *n;
122 struct fib_node *f;
123
124 hlist_for_each_entry_safe(f, node, n, &old_ht[i], fn_hash) {
125 struct hlist_head *new_head;
126
127 hlist_del(&f->fn_hash);
128
129 new_head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
130 hlist_add_head(&f->fn_hash, new_head);
131 }
132 }
133 }
134
135 static void fz_hash_free(struct hlist_head *hash, int divisor)
136 {
137 unsigned long size = divisor * sizeof(struct hlist_head);
138
139 if (size <= PAGE_SIZE)
140 kfree(hash);
141 else
142 free_pages((unsigned long)hash, get_order(size));
143 }
144
145 static void fn_rehash_zone(struct fn_zone *fz)
146 {
147 struct hlist_head *ht, *old_ht;
148 int old_divisor, new_divisor;
149 u32 new_hashmask;
150
151 old_divisor = fz->fz_divisor;
152
153 switch (old_divisor) {
154 case 16:
155 new_divisor = 256;
156 break;
157 case 256:
158 new_divisor = 1024;
159 break;
160 default:
161 if ((old_divisor << 1) > FZ_MAX_DIVISOR) {
162 printk(KERN_CRIT "route.c: bad divisor %d!\n", old_divisor);
163 return;
164 }
165 new_divisor = (old_divisor << 1);
166 break;
167 }
168
169 new_hashmask = (new_divisor - 1);
170
171 #if RT_CACHE_DEBUG >= 2
172 printk(KERN_DEBUG "fn_rehash_zone: hash for zone %d grows from %d\n",
173 fz->fz_order, old_divisor);
174 #endif
175
176 ht = fz_hash_alloc(new_divisor);
177
178 if (ht) {
179 write_lock_bh(&fib_hash_lock);
180 old_ht = fz->fz_hash;
181 fz->fz_hash = ht;
182 fz->fz_hashmask = new_hashmask;
183 fz->fz_divisor = new_divisor;
184 fn_rebuild_zone(fz, old_ht, old_divisor);
185 fib_hash_genid++;
186 write_unlock_bh(&fib_hash_lock);
187
188 fz_hash_free(old_ht, old_divisor);
189 }
190 }
191
192 static inline void fn_free_node(struct fib_node * f)
193 {
194 kmem_cache_free(fn_hash_kmem, f);
195 }
196
197 static inline void fn_free_alias(struct fib_alias *fa, struct fib_node *f)
198 {
199 fib_release_info(fa->fa_info);
200 if (fa == &f->fn_embedded_alias)
201 fa->fa_info = NULL;
202 else
203 kmem_cache_free(fn_alias_kmem, fa);
204 }
205
206 static struct fn_zone *
207 fn_new_zone(struct fn_hash *table, int z)
208 {
209 int i;
210 struct fn_zone *fz = kzalloc(sizeof(struct fn_zone), GFP_KERNEL);
211 if (!fz)
212 return NULL;
213
214 if (z) {
215 fz->fz_divisor = 16;
216 } else {
217 fz->fz_divisor = 1;
218 }
219 fz->fz_hashmask = (fz->fz_divisor - 1);
220 fz->fz_hash = fz_hash_alloc(fz->fz_divisor);
221 if (!fz->fz_hash) {
222 kfree(fz);
223 return NULL;
224 }
225 fz->fz_order = z;
226 fz->fz_mask = inet_make_mask(z);
227
228 /* Find the first not empty zone with more specific mask */
229 for (i=z+1; i<=32; i++)
230 if (table->fn_zones[i])
231 break;
232 write_lock_bh(&fib_hash_lock);
233 if (i>32) {
234 /* No more specific masks, we are the first. */
235 fz->fz_next = table->fn_zone_list;
236 table->fn_zone_list = fz;
237 } else {
238 fz->fz_next = table->fn_zones[i]->fz_next;
239 table->fn_zones[i]->fz_next = fz;
240 }
241 table->fn_zones[z] = fz;
242 fib_hash_genid++;
243 write_unlock_bh(&fib_hash_lock);
244 return fz;
245 }
246
247 static int
248 fn_hash_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
249 {
250 int err;
251 struct fn_zone *fz;
252 struct fn_hash *t = (struct fn_hash*)tb->tb_data;
253
254 read_lock(&fib_hash_lock);
255 for (fz = t->fn_zone_list; fz; fz = fz->fz_next) {
256 struct hlist_head *head;
257 struct hlist_node *node;
258 struct fib_node *f;
259 __be32 k = fz_key(flp->fl4_dst, fz);
260
261 head = &fz->fz_hash[fn_hash(k, fz)];
262 hlist_for_each_entry(f, node, head, fn_hash) {
263 if (f->fn_key != k)
264 continue;
265
266 err = fib_semantic_match(&f->fn_alias,
267 flp, res,
268 f->fn_key, fz->fz_mask,
269 fz->fz_order);
270 if (err <= 0)
271 goto out;
272 }
273 }
274 err = 1;
275 out:
276 read_unlock(&fib_hash_lock);
277 return err;
278 }
279
280 static void
281 fn_hash_select_default(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
282 {
283 int order, last_idx;
284 struct hlist_node *node;
285 struct fib_node *f;
286 struct fib_info *fi = NULL;
287 struct fib_info *last_resort;
288 struct fn_hash *t = (struct fn_hash*)tb->tb_data;
289 struct fn_zone *fz = t->fn_zones[0];
290
291 if (fz == NULL)
292 return;
293
294 last_idx = -1;
295 last_resort = NULL;
296 order = -1;
297
298 read_lock(&fib_hash_lock);
299 hlist_for_each_entry(f, node, &fz->fz_hash[0], fn_hash) {
300 struct fib_alias *fa;
301
302 list_for_each_entry(fa, &f->fn_alias, fa_list) {
303 struct fib_info *next_fi = fa->fa_info;
304
305 if (fa->fa_scope != res->scope ||
306 fa->fa_type != RTN_UNICAST)
307 continue;
308
309 if (next_fi->fib_priority > res->fi->fib_priority)
310 break;
311 if (!next_fi->fib_nh[0].nh_gw ||
312 next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
313 continue;
314 fa->fa_state |= FA_S_ACCESSED;
315
316 if (fi == NULL) {
317 if (next_fi != res->fi)
318 break;
319 } else if (!fib_detect_death(fi, order, &last_resort,
320 &last_idx, tb->tb_default)) {
321 fib_result_assign(res, fi);
322 tb->tb_default = order;
323 goto out;
324 }
325 fi = next_fi;
326 order++;
327 }
328 }
329
330 if (order <= 0 || fi == NULL) {
331 tb->tb_default = -1;
332 goto out;
333 }
334
335 if (!fib_detect_death(fi, order, &last_resort, &last_idx,
336 tb->tb_default)) {
337 fib_result_assign(res, fi);
338 tb->tb_default = order;
339 goto out;
340 }
341
342 if (last_idx >= 0)
343 fib_result_assign(res, last_resort);
344 tb->tb_default = last_idx;
345 out:
346 read_unlock(&fib_hash_lock);
347 }
348
349 /* Insert node F to FZ. */
350 static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
351 {
352 struct hlist_head *head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
353
354 hlist_add_head(&f->fn_hash, head);
355 }
356
357 /* Return the node in FZ matching KEY. */
358 static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key)
359 {
360 struct hlist_head *head = &fz->fz_hash[fn_hash(key, fz)];
361 struct hlist_node *node;
362 struct fib_node *f;
363
364 hlist_for_each_entry(f, node, head, fn_hash) {
365 if (f->fn_key == key)
366 return f;
367 }
368
369 return NULL;
370 }
371
372 static int fn_hash_insert(struct fib_table *tb, struct fib_config *cfg)
373 {
374 struct fn_hash *table = (struct fn_hash *) tb->tb_data;
375 struct fib_node *new_f = NULL;
376 struct fib_node *f;
377 struct fib_alias *fa, *new_fa;
378 struct fn_zone *fz;
379 struct fib_info *fi;
380 u8 tos = cfg->fc_tos;
381 __be32 key;
382 int err;
383
384 if (cfg->fc_dst_len > 32)
385 return -EINVAL;
386
387 fz = table->fn_zones[cfg->fc_dst_len];
388 if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len)))
389 return -ENOBUFS;
390
391 key = 0;
392 if (cfg->fc_dst) {
393 if (cfg->fc_dst & ~FZ_MASK(fz))
394 return -EINVAL;
395 key = fz_key(cfg->fc_dst, fz);
396 }
397
398 fi = fib_create_info(cfg);
399 if (IS_ERR(fi))
400 return PTR_ERR(fi);
401
402 if (fz->fz_nent > (fz->fz_divisor<<1) &&
403 fz->fz_divisor < FZ_MAX_DIVISOR &&
404 (cfg->fc_dst_len == 32 ||
405 (1 << cfg->fc_dst_len) > fz->fz_divisor))
406 fn_rehash_zone(fz);
407
408 f = fib_find_node(fz, key);
409
410 if (!f)
411 fa = NULL;
412 else
413 fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority);
414
415 /* Now fa, if non-NULL, points to the first fib alias
416 * with the same keys [prefix,tos,priority], if such key already
417 * exists or to the node before which we will insert new one.
418 *
419 * If fa is NULL, we will need to allocate a new one and
420 * insert to the head of f.
421 *
422 * If f is NULL, no fib node matched the destination key
423 * and we need to allocate a new one of those as well.
424 */
425
426 if (fa && fa->fa_tos == tos &&
427 fa->fa_info->fib_priority == fi->fib_priority) {
428 struct fib_alias *fa_first, *fa_match;
429
430 err = -EEXIST;
431 if (cfg->fc_nlflags & NLM_F_EXCL)
432 goto out;
433
434 /* We have 2 goals:
435 * 1. Find exact match for type, scope, fib_info to avoid
436 * duplicate routes
437 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
438 */
439 fa_match = NULL;
440 fa_first = fa;
441 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
442 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
443 if (fa->fa_tos != tos)
444 break;
445 if (fa->fa_info->fib_priority != fi->fib_priority)
446 break;
447 if (fa->fa_type == cfg->fc_type &&
448 fa->fa_scope == cfg->fc_scope &&
449 fa->fa_info == fi) {
450 fa_match = fa;
451 break;
452 }
453 }
454
455 if (cfg->fc_nlflags & NLM_F_REPLACE) {
456 struct fib_info *fi_drop;
457 u8 state;
458
459 fa = fa_first;
460 if (fa_match) {
461 if (fa == fa_match)
462 err = 0;
463 goto out;
464 }
465 write_lock_bh(&fib_hash_lock);
466 fi_drop = fa->fa_info;
467 fa->fa_info = fi;
468 fa->fa_type = cfg->fc_type;
469 fa->fa_scope = cfg->fc_scope;
470 state = fa->fa_state;
471 fa->fa_state &= ~FA_S_ACCESSED;
472 fib_hash_genid++;
473 write_unlock_bh(&fib_hash_lock);
474
475 fib_release_info(fi_drop);
476 if (state & FA_S_ACCESSED)
477 rt_cache_flush(-1);
478 rtmsg_fib(RTM_NEWROUTE, key, fa, cfg->fc_dst_len, tb->tb_id,
479 &cfg->fc_nlinfo, NLM_F_REPLACE);
480 return 0;
481 }
482
483 /* Error if we find a perfect match which
484 * uses the same scope, type, and nexthop
485 * information.
486 */
487 if (fa_match)
488 goto out;
489
490 if (!(cfg->fc_nlflags & NLM_F_APPEND))
491 fa = fa_first;
492 }
493
494 err = -ENOENT;
495 if (!(cfg->fc_nlflags & NLM_F_CREATE))
496 goto out;
497
498 err = -ENOBUFS;
499
500 if (!f) {
501 new_f = kmem_cache_zalloc(fn_hash_kmem, GFP_KERNEL);
502 if (new_f == NULL)
503 goto out;
504
505 INIT_HLIST_NODE(&new_f->fn_hash);
506 INIT_LIST_HEAD(&new_f->fn_alias);
507 new_f->fn_key = key;
508 f = new_f;
509 }
510
511 new_fa = &f->fn_embedded_alias;
512 if (new_fa->fa_info != NULL) {
513 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
514 if (new_fa == NULL)
515 goto out;
516 }
517 new_fa->fa_info = fi;
518 new_fa->fa_tos = tos;
519 new_fa->fa_type = cfg->fc_type;
520 new_fa->fa_scope = cfg->fc_scope;
521 new_fa->fa_state = 0;
522
523 /*
524 * Insert new entry to the list.
525 */
526
527 write_lock_bh(&fib_hash_lock);
528 if (new_f)
529 fib_insert_node(fz, new_f);
530 list_add_tail(&new_fa->fa_list,
531 (fa ? &fa->fa_list : &f->fn_alias));
532 fib_hash_genid++;
533 write_unlock_bh(&fib_hash_lock);
534
535 if (new_f)
536 fz->fz_nent++;
537 rt_cache_flush(-1);
538
539 rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id,
540 &cfg->fc_nlinfo, 0);
541 return 0;
542
543 out:
544 if (new_f)
545 kmem_cache_free(fn_hash_kmem, new_f);
546 fib_release_info(fi);
547 return err;
548 }
549
550
551 static int fn_hash_delete(struct fib_table *tb, struct fib_config *cfg)
552 {
553 struct fn_hash *table = (struct fn_hash*)tb->tb_data;
554 struct fib_node *f;
555 struct fib_alias *fa, *fa_to_delete;
556 struct fn_zone *fz;
557 __be32 key;
558
559 if (cfg->fc_dst_len > 32)
560 return -EINVAL;
561
562 if ((fz = table->fn_zones[cfg->fc_dst_len]) == NULL)
563 return -ESRCH;
564
565 key = 0;
566 if (cfg->fc_dst) {
567 if (cfg->fc_dst & ~FZ_MASK(fz))
568 return -EINVAL;
569 key = fz_key(cfg->fc_dst, fz);
570 }
571
572 f = fib_find_node(fz, key);
573
574 if (!f)
575 fa = NULL;
576 else
577 fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0);
578 if (!fa)
579 return -ESRCH;
580
581 fa_to_delete = NULL;
582 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
583 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
584 struct fib_info *fi = fa->fa_info;
585
586 if (fa->fa_tos != cfg->fc_tos)
587 break;
588
589 if ((!cfg->fc_type ||
590 fa->fa_type == cfg->fc_type) &&
591 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
592 fa->fa_scope == cfg->fc_scope) &&
593 (!cfg->fc_protocol ||
594 fi->fib_protocol == cfg->fc_protocol) &&
595 fib_nh_match(cfg, fi) == 0) {
596 fa_to_delete = fa;
597 break;
598 }
599 }
600
601 if (fa_to_delete) {
602 int kill_fn;
603
604 fa = fa_to_delete;
605 rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len,
606 tb->tb_id, &cfg->fc_nlinfo, 0);
607
608 kill_fn = 0;
609 write_lock_bh(&fib_hash_lock);
610 list_del(&fa->fa_list);
611 if (list_empty(&f->fn_alias)) {
612 hlist_del(&f->fn_hash);
613 kill_fn = 1;
614 }
615 fib_hash_genid++;
616 write_unlock_bh(&fib_hash_lock);
617
618 if (fa->fa_state & FA_S_ACCESSED)
619 rt_cache_flush(-1);
620 fn_free_alias(fa, f);
621 if (kill_fn) {
622 fn_free_node(f);
623 fz->fz_nent--;
624 }
625
626 return 0;
627 }
628 return -ESRCH;
629 }
630
631 static int fn_flush_list(struct fn_zone *fz, int idx)
632 {
633 struct hlist_head *head = &fz->fz_hash[idx];
634 struct hlist_node *node, *n;
635 struct fib_node *f;
636 int found = 0;
637
638 hlist_for_each_entry_safe(f, node, n, head, fn_hash) {
639 struct fib_alias *fa, *fa_node;
640 int kill_f;
641
642 kill_f = 0;
643 list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) {
644 struct fib_info *fi = fa->fa_info;
645
646 if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
647 write_lock_bh(&fib_hash_lock);
648 list_del(&fa->fa_list);
649 if (list_empty(&f->fn_alias)) {
650 hlist_del(&f->fn_hash);
651 kill_f = 1;
652 }
653 fib_hash_genid++;
654 write_unlock_bh(&fib_hash_lock);
655
656 fn_free_alias(fa, f);
657 found++;
658 }
659 }
660 if (kill_f) {
661 fn_free_node(f);
662 fz->fz_nent--;
663 }
664 }
665 return found;
666 }
667
668 static int fn_hash_flush(struct fib_table *tb)
669 {
670 struct fn_hash *table = (struct fn_hash *) tb->tb_data;
671 struct fn_zone *fz;
672 int found = 0;
673
674 for (fz = table->fn_zone_list; fz; fz = fz->fz_next) {
675 int i;
676
677 for (i = fz->fz_divisor - 1; i >= 0; i--)
678 found += fn_flush_list(fz, i);
679 }
680 return found;
681 }
682
683
684 static inline int
685 fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
686 struct fib_table *tb,
687 struct fn_zone *fz,
688 struct hlist_head *head)
689 {
690 struct hlist_node *node;
691 struct fib_node *f;
692 int i, s_i;
693
694 s_i = cb->args[4];
695 i = 0;
696 hlist_for_each_entry(f, node, head, fn_hash) {
697 struct fib_alias *fa;
698
699 list_for_each_entry(fa, &f->fn_alias, fa_list) {
700 if (i < s_i)
701 goto next;
702
703 if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
704 cb->nlh->nlmsg_seq,
705 RTM_NEWROUTE,
706 tb->tb_id,
707 fa->fa_type,
708 fa->fa_scope,
709 f->fn_key,
710 fz->fz_order,
711 fa->fa_tos,
712 fa->fa_info,
713 NLM_F_MULTI) < 0) {
714 cb->args[4] = i;
715 return -1;
716 }
717 next:
718 i++;
719 }
720 }
721 cb->args[4] = i;
722 return skb->len;
723 }
724
725 static inline int
726 fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
727 struct fib_table *tb,
728 struct fn_zone *fz)
729 {
730 int h, s_h;
731
732 if (fz->fz_hash == NULL)
733 return skb->len;
734 s_h = cb->args[3];
735 for (h = s_h; h < fz->fz_divisor; h++) {
736 if (hlist_empty(&fz->fz_hash[h]))
737 continue;
738 if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h]) < 0) {
739 cb->args[3] = h;
740 return -1;
741 }
742 memset(&cb->args[4], 0,
743 sizeof(cb->args) - 4*sizeof(cb->args[0]));
744 }
745 cb->args[3] = h;
746 return skb->len;
747 }
748
749 static int fn_hash_dump(struct fib_table *tb, struct sk_buff *skb, struct netlink_callback *cb)
750 {
751 int m, s_m;
752 struct fn_zone *fz;
753 struct fn_hash *table = (struct fn_hash*)tb->tb_data;
754
755 s_m = cb->args[2];
756 read_lock(&fib_hash_lock);
757 for (fz = table->fn_zone_list, m=0; fz; fz = fz->fz_next, m++) {
758 if (m < s_m) continue;
759 if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
760 cb->args[2] = m;
761 read_unlock(&fib_hash_lock);
762 return -1;
763 }
764 memset(&cb->args[3], 0,
765 sizeof(cb->args) - 3*sizeof(cb->args[0]));
766 }
767 read_unlock(&fib_hash_lock);
768 cb->args[2] = m;
769 return skb->len;
770 }
771
772 void __init fib_hash_init(void)
773 {
774 fn_hash_kmem = kmem_cache_create("ip_fib_hash", sizeof(struct fib_node),
775 0, SLAB_PANIC, NULL);
776
777 fn_alias_kmem = kmem_cache_create("ip_fib_alias", sizeof(struct fib_alias),
778 0, SLAB_PANIC, NULL);
779
780 }
781
782 struct fib_table *fib_hash_table(u32 id)
783 {
784 struct fib_table *tb;
785
786 tb = kmalloc(sizeof(struct fib_table) + sizeof(struct fn_hash),
787 GFP_KERNEL);
788 if (tb == NULL)
789 return NULL;
790
791 tb->tb_id = id;
792 tb->tb_default = -1;
793 tb->tb_lookup = fn_hash_lookup;
794 tb->tb_insert = fn_hash_insert;
795 tb->tb_delete = fn_hash_delete;
796 tb->tb_flush = fn_hash_flush;
797 tb->tb_select_default = fn_hash_select_default;
798 tb->tb_dump = fn_hash_dump;
799 memset(tb->tb_data, 0, sizeof(struct fn_hash));
800 return tb;
801 }
802
803 /* ------------------------------------------------------------------------ */
804 #ifdef CONFIG_PROC_FS
805
806 struct fib_iter_state {
807 struct seq_net_private p;
808 struct fn_zone *zone;
809 int bucket;
810 struct hlist_head *hash_head;
811 struct fib_node *fn;
812 struct fib_alias *fa;
813 loff_t pos;
814 unsigned int genid;
815 int valid;
816 };
817
818 static struct fib_alias *fib_get_first(struct seq_file *seq)
819 {
820 struct fib_iter_state *iter = seq->private;
821 struct fib_table *main_table;
822 struct fn_hash *table;
823
824 main_table = fib_get_table(iter->p.net, RT_TABLE_MAIN);
825 table = (struct fn_hash *)main_table->tb_data;
826
827 iter->bucket = 0;
828 iter->hash_head = NULL;
829 iter->fn = NULL;
830 iter->fa = NULL;
831 iter->pos = 0;
832 iter->genid = fib_hash_genid;
833 iter->valid = 1;
834
835 for (iter->zone = table->fn_zone_list; iter->zone;
836 iter->zone = iter->zone->fz_next) {
837 int maxslot;
838
839 if (!iter->zone->fz_nent)
840 continue;
841
842 iter->hash_head = iter->zone->fz_hash;
843 maxslot = iter->zone->fz_divisor;
844
845 for (iter->bucket = 0; iter->bucket < maxslot;
846 ++iter->bucket, ++iter->hash_head) {
847 struct hlist_node *node;
848 struct fib_node *fn;
849
850 hlist_for_each_entry(fn,node,iter->hash_head,fn_hash) {
851 struct fib_alias *fa;
852
853 list_for_each_entry(fa,&fn->fn_alias,fa_list) {
854 iter->fn = fn;
855 iter->fa = fa;
856 goto out;
857 }
858 }
859 }
860 }
861 out:
862 return iter->fa;
863 }
864
865 static struct fib_alias *fib_get_next(struct seq_file *seq)
866 {
867 struct fib_iter_state *iter = seq->private;
868 struct fib_node *fn;
869 struct fib_alias *fa;
870
871 /* Advance FA, if any. */
872 fn = iter->fn;
873 fa = iter->fa;
874 if (fa) {
875 BUG_ON(!fn);
876 list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) {
877 iter->fa = fa;
878 goto out;
879 }
880 }
881
882 fa = iter->fa = NULL;
883
884 /* Advance FN. */
885 if (fn) {
886 struct hlist_node *node = &fn->fn_hash;
887 hlist_for_each_entry_continue(fn, node, fn_hash) {
888 iter->fn = fn;
889
890 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
891 iter->fa = fa;
892 goto out;
893 }
894 }
895 }
896
897 fn = iter->fn = NULL;
898
899 /* Advance hash chain. */
900 if (!iter->zone)
901 goto out;
902
903 for (;;) {
904 struct hlist_node *node;
905 int maxslot;
906
907 maxslot = iter->zone->fz_divisor;
908
909 while (++iter->bucket < maxslot) {
910 iter->hash_head++;
911
912 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
913 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
914 iter->fn = fn;
915 iter->fa = fa;
916 goto out;
917 }
918 }
919 }
920
921 iter->zone = iter->zone->fz_next;
922
923 if (!iter->zone)
924 goto out;
925
926 iter->bucket = 0;
927 iter->hash_head = iter->zone->fz_hash;
928
929 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
930 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
931 iter->fn = fn;
932 iter->fa = fa;
933 goto out;
934 }
935 }
936 }
937 out:
938 iter->pos++;
939 return fa;
940 }
941
942 static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos)
943 {
944 struct fib_iter_state *iter = seq->private;
945 struct fib_alias *fa;
946
947 if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) {
948 fa = iter->fa;
949 pos -= iter->pos;
950 } else
951 fa = fib_get_first(seq);
952
953 if (fa)
954 while (pos && (fa = fib_get_next(seq)))
955 --pos;
956 return pos ? NULL : fa;
957 }
958
959 static void *fib_seq_start(struct seq_file *seq, loff_t *pos)
960 __acquires(fib_hash_lock)
961 {
962 struct fib_iter_state *iter = seq->private;
963 void *v = NULL;
964
965 read_lock(&fib_hash_lock);
966 if (fib_get_table(iter->p.net, RT_TABLE_MAIN))
967 v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
968 return v;
969 }
970
971 static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
972 {
973 ++*pos;
974 return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
975 }
976
977 static void fib_seq_stop(struct seq_file *seq, void *v)
978 __releases(fib_hash_lock)
979 {
980 read_unlock(&fib_hash_lock);
981 }
982
983 static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
984 {
985 static const unsigned type2flags[RTN_MAX + 1] = {
986 [7] = RTF_REJECT, [8] = RTF_REJECT,
987 };
988 unsigned flags = type2flags[type];
989
990 if (fi && fi->fib_nh->nh_gw)
991 flags |= RTF_GATEWAY;
992 if (mask == htonl(0xFFFFFFFF))
993 flags |= RTF_HOST;
994 flags |= RTF_UP;
995 return flags;
996 }
997
998 /*
999 * This outputs /proc/net/route.
1000 *
1001 * It always works in backward compatibility mode.
1002 * The format of the file is not supposed to be changed.
1003 */
1004 static int fib_seq_show(struct seq_file *seq, void *v)
1005 {
1006 struct fib_iter_state *iter;
1007 char bf[128];
1008 __be32 prefix, mask;
1009 unsigned flags;
1010 struct fib_node *f;
1011 struct fib_alias *fa;
1012 struct fib_info *fi;
1013
1014 if (v == SEQ_START_TOKEN) {
1015 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
1016 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
1017 "\tWindow\tIRTT");
1018 goto out;
1019 }
1020
1021 iter = seq->private;
1022 f = iter->fn;
1023 fa = iter->fa;
1024 fi = fa->fa_info;
1025 prefix = f->fn_key;
1026 mask = FZ_MASK(iter->zone);
1027 flags = fib_flag_trans(fa->fa_type, mask, fi);
1028 if (fi)
1029 snprintf(bf, sizeof(bf),
1030 "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
1031 fi->fib_dev ? fi->fib_dev->name : "*", prefix,
1032 fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
1033 mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
1034 fi->fib_window,
1035 fi->fib_rtt >> 3);
1036 else
1037 snprintf(bf, sizeof(bf),
1038 "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
1039 prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0);
1040 seq_printf(seq, "%-127s\n", bf);
1041 out:
1042 return 0;
1043 }
1044
1045 static const struct seq_operations fib_seq_ops = {
1046 .start = fib_seq_start,
1047 .next = fib_seq_next,
1048 .stop = fib_seq_stop,
1049 .show = fib_seq_show,
1050 };
1051
1052 static int fib_seq_open(struct inode *inode, struct file *file)
1053 {
1054 return seq_open_net(inode, file, &fib_seq_ops,
1055 sizeof(struct fib_iter_state));
1056 }
1057
1058 static const struct file_operations fib_seq_fops = {
1059 .owner = THIS_MODULE,
1060 .open = fib_seq_open,
1061 .read = seq_read,
1062 .llseek = seq_lseek,
1063 .release = seq_release_net,
1064 };
1065
1066 int __net_init fib_proc_init(struct net *net)
1067 {
1068 if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_seq_fops))
1069 return -ENOMEM;
1070 return 0;
1071 }
1072
1073 void __net_exit fib_proc_exit(struct net *net)
1074 {
1075 proc_net_remove(net, "route");
1076 }
1077 #endif /* CONFIG_PROC_FS */
Linux kernel - Deliverables
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