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USB: open disconnect race in usblcd
[linux-2.6/mini2440.git] / net / ipv4 / fib_hash.c
blob527a6e0af5b60eb48b9e15459e8877db10c29db8
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 };
56
57 struct 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
75 struct fn_hash {
76 struct fn_zone *fn_zones[33];
77 struct fn_zone *fn_zone_list;
78 };
79
80 static 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
90 static inline __be32 fz_key(__be32 dst, struct fn_zone *fz)
91 {
92 return dst & FZ_MASK(fz);
93 }
94
95 static DEFINE_RWLOCK(fib_hash_lock);
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 kmalloc(size, GFP_KERNEL);
106 } else {
107 return (struct hlist_head *)
108 __get_free_pages(GFP_KERNEL, get_order(size));
109 }
110 }
111
112 /* The fib hash lock must be held when this is called. */
113 static 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
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 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("fn_rehash_zone: hash for zone %d grows from %d\n", fz->fz_order, old_divisor);
172 #endif
173
174 ht = fz_hash_alloc(new_divisor);
175
176 if (ht) {
177 memset(ht, 0, new_divisor * sizeof(struct hlist_head));
178
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)
198 {
199 fib_release_info(fa->fa_info);
200 kmem_cache_free(fn_alias_kmem, fa);
201 }
202
203 static struct fn_zone *
204 fn_new_zone(struct fn_hash *table, int z)
205 {
206 int i;
207 struct fn_zone *fz = kzalloc(sizeof(struct fn_zone), GFP_KERNEL);
208 if (!fz)
209 return NULL;
210
211 if (z) {
212 fz->fz_divisor = 16;
213 } else {
214 fz->fz_divisor = 1;
215 }
216 fz->fz_hashmask = (fz->fz_divisor - 1);
217 fz->fz_hash = fz_hash_alloc(fz->fz_divisor);
218 if (!fz->fz_hash) {
219 kfree(fz);
220 return NULL;
221 }
222 memset(fz->fz_hash, 0, fz->fz_divisor * sizeof(struct hlist_head *));
223 fz->fz_order = z;
224 fz->fz_mask = inet_make_mask(z);
225
226 /* Find the first not empty zone with more specific mask */
227 for (i=z+1; i<=32; i++)
228 if (table->fn_zones[i])
229 break;
230 write_lock_bh(&fib_hash_lock);
231 if (i>32) {
232 /* No more specific masks, we are the first. */
233 fz->fz_next = table->fn_zone_list;
234 table->fn_zone_list = fz;
235 } else {
236 fz->fz_next = table->fn_zones[i]->fz_next;
237 table->fn_zones[i]->fz_next = fz;
238 }
239 table->fn_zones[z] = fz;
240 fib_hash_genid++;
241 write_unlock_bh(&fib_hash_lock);
242 return fz;
243 }
244
245 static int
246 fn_hash_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
247 {
248 int err;
249 struct fn_zone *fz;
250 struct fn_hash *t = (struct fn_hash*)tb->tb_data;
251
252 read_lock(&fib_hash_lock);
253 for (fz = t->fn_zone_list; fz; fz = fz->fz_next) {
254 struct hlist_head *head;
255 struct hlist_node *node;
256 struct fib_node *f;
257 __be32 k = fz_key(flp->fl4_dst, fz);
258
259 head = &fz->fz_hash[fn_hash(k, fz)];
260 hlist_for_each_entry(f, node, head, fn_hash) {
261 if (f->fn_key != k)
262 continue;
263
264 err = fib_semantic_match(&f->fn_alias,
265 flp, res,
266 f->fn_key, fz->fz_mask,
267 fz->fz_order);
268 if (err <= 0)
269 goto out;
270 }
271 }
272 err = 1;
273 out:
274 read_unlock(&fib_hash_lock);
275 return err;
276 }
277
278 static int fn_hash_last_dflt=-1;
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, &fn_hash_last_dflt)) {
321 if (res->fi)
322 fib_info_put(res->fi);
323 res->fi = fi;
324 atomic_inc(&fi->fib_clntref);
325 fn_hash_last_dflt = order;
326 goto out;
327 }
328 fi = next_fi;
329 order++;
330 }
331 }
332
333 if (order <= 0 || fi == NULL) {
334 fn_hash_last_dflt = -1;
335 goto out;
336 }
337
338 if (!fib_detect_death(fi, order, &last_resort, &last_idx, &fn_hash_last_dflt)) {
339 if (res->fi)
340 fib_info_put(res->fi);
341 res->fi = fi;
342 atomic_inc(&fi->fib_clntref);
343 fn_hash_last_dflt = order;
344 goto out;
345 }
346
347 if (last_idx >= 0) {
348 if (res->fi)
349 fib_info_put(res->fi);
350 res->fi = last_resort;
351 if (last_resort)
352 atomic_inc(&last_resort->fib_clntref);
353 }
354 fn_hash_last_dflt = last_idx;
355 out:
356 read_unlock(&fib_hash_lock);
357 }
358
359 /* Insert node F to FZ. */
360 static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
361 {
362 struct hlist_head *head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
363
364 hlist_add_head(&f->fn_hash, head);
365 }
366
367 /* Return the node in FZ matching KEY. */
368 static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key)
369 {
370 struct hlist_head *head = &fz->fz_hash[fn_hash(key, fz)];
371 struct hlist_node *node;
372 struct fib_node *f;
373
374 hlist_for_each_entry(f, node, head, fn_hash) {
375 if (f->fn_key == key)
376 return f;
377 }
378
379 return NULL;
380 }
381
382 static int fn_hash_insert(struct fib_table *tb, struct fib_config *cfg)
383 {
384 struct fn_hash *table = (struct fn_hash *) tb->tb_data;
385 struct fib_node *new_f, *f;
386 struct fib_alias *fa, *new_fa;
387 struct fn_zone *fz;
388 struct fib_info *fi;
389 u8 tos = cfg->fc_tos;
390 __be32 key;
391 int err;
392
393 if (cfg->fc_dst_len > 32)
394 return -EINVAL;
395
396 fz = table->fn_zones[cfg->fc_dst_len];
397 if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len)))
398 return -ENOBUFS;
399
400 key = 0;
401 if (cfg->fc_dst) {
402 if (cfg->fc_dst & ~FZ_MASK(fz))
403 return -EINVAL;
404 key = fz_key(cfg->fc_dst, fz);
405 }
406
407 fi = fib_create_info(cfg);
408 if (IS_ERR(fi))
409 return PTR_ERR(fi);
410
411 if (fz->fz_nent > (fz->fz_divisor<<1) &&
412 fz->fz_divisor < FZ_MAX_DIVISOR &&
413 (cfg->fc_dst_len == 32 ||
414 (1 << cfg->fc_dst_len) > fz->fz_divisor))
415 fn_rehash_zone(fz);
416
417 f = fib_find_node(fz, key);
418
419 if (!f)
420 fa = NULL;
421 else
422 fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority);
423
424 /* Now fa, if non-NULL, points to the first fib alias
425 * with the same keys [prefix,tos,priority], if such key already
426 * exists or to the node before which we will insert new one.
427 *
428 * If fa is NULL, we will need to allocate a new one and
429 * insert to the head of f.
430 *
431 * If f is NULL, no fib node matched the destination key
432 * and we need to allocate a new one of those as well.
433 */
434
435 if (fa && fa->fa_tos == tos &&
436 fa->fa_info->fib_priority == fi->fib_priority) {
437 struct fib_alias *fa_orig;
438
439 err = -EEXIST;
440 if (cfg->fc_nlflags & NLM_F_EXCL)
441 goto out;
442
443 if (cfg->fc_nlflags & NLM_F_REPLACE) {
444 struct fib_info *fi_drop;
445 u8 state;
446
447 write_lock_bh(&fib_hash_lock);
448 fi_drop = fa->fa_info;
449 fa->fa_info = fi;
450 fa->fa_type = cfg->fc_type;
451 fa->fa_scope = cfg->fc_scope;
452 state = fa->fa_state;
453 fa->fa_state &= ~FA_S_ACCESSED;
454 fib_hash_genid++;
455 write_unlock_bh(&fib_hash_lock);
456
457 fib_release_info(fi_drop);
458 if (state & FA_S_ACCESSED)
459 rt_cache_flush(-1);
460 rtmsg_fib(RTM_NEWROUTE, key, fa, cfg->fc_dst_len, tb->tb_id,
461 &cfg->fc_nlinfo, NLM_F_REPLACE);
462 return 0;
463 }
464
465 /* Error if we find a perfect match which
466 * uses the same scope, type, and nexthop
467 * information.
468 */
469 fa_orig = fa;
470 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
471 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
472 if (fa->fa_tos != tos)
473 break;
474 if (fa->fa_info->fib_priority != fi->fib_priority)
475 break;
476 if (fa->fa_type == cfg->fc_type &&
477 fa->fa_scope == cfg->fc_scope &&
478 fa->fa_info == fi)
479 goto out;
480 }
481 if (!(cfg->fc_nlflags & NLM_F_APPEND))
482 fa = fa_orig;
483 }
484
485 err = -ENOENT;
486 if (!(cfg->fc_nlflags & NLM_F_CREATE))
487 goto out;
488
489 err = -ENOBUFS;
490 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
491 if (new_fa == NULL)
492 goto out;
493
494 new_f = NULL;
495 if (!f) {
496 new_f = kmem_cache_alloc(fn_hash_kmem, GFP_KERNEL);
497 if (new_f == NULL)
498 goto out_free_new_fa;
499
500 INIT_HLIST_NODE(&new_f->fn_hash);
501 INIT_LIST_HEAD(&new_f->fn_alias);
502 new_f->fn_key = key;
503 f = new_f;
504 }
505
506 new_fa->fa_info = fi;
507 new_fa->fa_tos = tos;
508 new_fa->fa_type = cfg->fc_type;
509 new_fa->fa_scope = cfg->fc_scope;
510 new_fa->fa_state = 0;
511
512 /*
513 * Insert new entry to the list.
514 */
515
516 write_lock_bh(&fib_hash_lock);
517 if (new_f)
518 fib_insert_node(fz, new_f);
519 list_add_tail(&new_fa->fa_list,
520 (fa ? &fa->fa_list : &f->fn_alias));
521 fib_hash_genid++;
522 write_unlock_bh(&fib_hash_lock);
523
524 if (new_f)
525 fz->fz_nent++;
526 rt_cache_flush(-1);
527
528 rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id,
529 &cfg->fc_nlinfo, 0);
530 return 0;
531
532 out_free_new_fa:
533 kmem_cache_free(fn_alias_kmem, new_fa);
534 out:
535 fib_release_info(fi);
536 return err;
537 }
538
539
540 static int fn_hash_delete(struct fib_table *tb, struct fib_config *cfg)
541 {
542 struct fn_hash *table = (struct fn_hash*)tb->tb_data;
543 struct fib_node *f;
544 struct fib_alias *fa, *fa_to_delete;
545 struct fn_zone *fz;
546 __be32 key;
547
548 if (cfg->fc_dst_len > 32)
549 return -EINVAL;
550
551 if ((fz = table->fn_zones[cfg->fc_dst_len]) == NULL)
552 return -ESRCH;
553
554 key = 0;
555 if (cfg->fc_dst) {
556 if (cfg->fc_dst & ~FZ_MASK(fz))
557 return -EINVAL;
558 key = fz_key(cfg->fc_dst, fz);
559 }
560
561 f = fib_find_node(fz, key);
562
563 if (!f)
564 fa = NULL;
565 else
566 fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0);
567 if (!fa)
568 return -ESRCH;
569
570 fa_to_delete = NULL;
571 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
572 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
573 struct fib_info *fi = fa->fa_info;
574
575 if (fa->fa_tos != cfg->fc_tos)
576 break;
577
578 if ((!cfg->fc_type ||
579 fa->fa_type == cfg->fc_type) &&
580 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
581 fa->fa_scope == cfg->fc_scope) &&
582 (!cfg->fc_protocol ||
583 fi->fib_protocol == cfg->fc_protocol) &&
584 fib_nh_match(cfg, fi) == 0) {
585 fa_to_delete = fa;
586 break;
587 }
588 }
589
590 if (fa_to_delete) {
591 int kill_fn;
592
593 fa = fa_to_delete;
594 rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len,
595 tb->tb_id, &cfg->fc_nlinfo, 0);
596
597 kill_fn = 0;
598 write_lock_bh(&fib_hash_lock);
599 list_del(&fa->fa_list);
600 if (list_empty(&f->fn_alias)) {
601 hlist_del(&f->fn_hash);
602 kill_fn = 1;
603 }
604 fib_hash_genid++;
605 write_unlock_bh(&fib_hash_lock);
606
607 if (fa->fa_state & FA_S_ACCESSED)
608 rt_cache_flush(-1);
609 fn_free_alias(fa);
610 if (kill_fn) {
611 fn_free_node(f);
612 fz->fz_nent--;
613 }
614
615 return 0;
616 }
617 return -ESRCH;
618 }
619
620 static int fn_flush_list(struct fn_zone *fz, int idx)
621 {
622 struct hlist_head *head = &fz->fz_hash[idx];
623 struct hlist_node *node, *n;
624 struct fib_node *f;
625 int found = 0;
626
627 hlist_for_each_entry_safe(f, node, n, head, fn_hash) {
628 struct fib_alias *fa, *fa_node;
629 int kill_f;
630
631 kill_f = 0;
632 list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) {
633 struct fib_info *fi = fa->fa_info;
634
635 if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
636 write_lock_bh(&fib_hash_lock);
637 list_del(&fa->fa_list);
638 if (list_empty(&f->fn_alias)) {
639 hlist_del(&f->fn_hash);
640 kill_f = 1;
641 }
642 fib_hash_genid++;
643 write_unlock_bh(&fib_hash_lock);
644
645 fn_free_alias(fa);
646 found++;
647 }
648 }
649 if (kill_f) {
650 fn_free_node(f);
651 fz->fz_nent--;
652 }
653 }
654 return found;
655 }
656
657 static int fn_hash_flush(struct fib_table *tb)
658 {
659 struct fn_hash *table = (struct fn_hash *) tb->tb_data;
660 struct fn_zone *fz;
661 int found = 0;
662
663 for (fz = table->fn_zone_list; fz; fz = fz->fz_next) {
664 int i;
665
666 for (i = fz->fz_divisor - 1; i >= 0; i--)
667 found += fn_flush_list(fz, i);
668 }
669 return found;
670 }
671
672
673 static inline int
674 fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
675 struct fib_table *tb,
676 struct fn_zone *fz,
677 struct hlist_head *head)
678 {
679 struct hlist_node *node;
680 struct fib_node *f;
681 int i, s_i;
682
683 s_i = cb->args[4];
684 i = 0;
685 hlist_for_each_entry(f, node, head, fn_hash) {
686 struct fib_alias *fa;
687
688 list_for_each_entry(fa, &f->fn_alias, fa_list) {
689 if (i < s_i)
690 goto next;
691
692 if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
693 cb->nlh->nlmsg_seq,
694 RTM_NEWROUTE,
695 tb->tb_id,
696 fa->fa_type,
697 fa->fa_scope,
698 f->fn_key,
699 fz->fz_order,
700 fa->fa_tos,
701 fa->fa_info,
702 NLM_F_MULTI) < 0) {
703 cb->args[4] = i;
704 return -1;
705 }
706 next:
707 i++;
708 }
709 }
710 cb->args[4] = i;
711 return skb->len;
712 }
713
714 static inline int
715 fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
716 struct fib_table *tb,
717 struct fn_zone *fz)
718 {
719 int h, s_h;
720
721 s_h = cb->args[3];
722 for (h=0; h < fz->fz_divisor; h++) {
723 if (h < s_h) continue;
724 if (h > s_h)
725 memset(&cb->args[4], 0,
726 sizeof(cb->args) - 4*sizeof(cb->args[0]));
727 if (fz->fz_hash == NULL ||
728 hlist_empty(&fz->fz_hash[h]))
729 continue;
730 if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h])<0) {
731 cb->args[3] = h;
732 return -1;
733 }
734 }
735 cb->args[3] = h;
736 return skb->len;
737 }
738
739 static int fn_hash_dump(struct fib_table *tb, struct sk_buff *skb, struct netlink_callback *cb)
740 {
741 int m, s_m;
742 struct fn_zone *fz;
743 struct fn_hash *table = (struct fn_hash*)tb->tb_data;
744
745 s_m = cb->args[2];
746 read_lock(&fib_hash_lock);
747 for (fz = table->fn_zone_list, m=0; fz; fz = fz->fz_next, m++) {
748 if (m < s_m) continue;
749 if (m > s_m)
750 memset(&cb->args[3], 0,
751 sizeof(cb->args) - 3*sizeof(cb->args[0]));
752 if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
753 cb->args[2] = m;
754 read_unlock(&fib_hash_lock);
755 return -1;
756 }
757 }
758 read_unlock(&fib_hash_lock);
759 cb->args[2] = m;
760 return skb->len;
761 }
762
763 #ifdef CONFIG_IP_MULTIPLE_TABLES
764 struct fib_table * fib_hash_init(u32 id)
765 #else
766 struct fib_table * __init fib_hash_init(u32 id)
767 #endif
768 {
769 struct fib_table *tb;
770
771 if (fn_hash_kmem == NULL)
772 fn_hash_kmem = kmem_cache_create("ip_fib_hash",
773 sizeof(struct fib_node),
774 0, SLAB_HWCACHE_ALIGN,
775 NULL);
776
777 if (fn_alias_kmem == NULL)
778 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
779 sizeof(struct fib_alias),
780 0, SLAB_HWCACHE_ALIGN,
781 NULL);
782
783 tb = kmalloc(sizeof(struct fib_table) + sizeof(struct fn_hash),
784 GFP_KERNEL);
785 if (tb == NULL)
786 return NULL;
787
788 tb->tb_id = id;
789 tb->tb_lookup = fn_hash_lookup;
790 tb->tb_insert = fn_hash_insert;
791 tb->tb_delete = fn_hash_delete;
792 tb->tb_flush = fn_hash_flush;
793 tb->tb_select_default = fn_hash_select_default;
794 tb->tb_dump = fn_hash_dump;
795 memset(tb->tb_data, 0, sizeof(struct fn_hash));
796 return tb;
797 }
798
799 /* ------------------------------------------------------------------------ */
800 #ifdef CONFIG_PROC_FS
801
802 struct fib_iter_state {
803 struct fn_zone *zone;
804 int bucket;
805 struct hlist_head *hash_head;
806 struct fib_node *fn;
807 struct fib_alias *fa;
808 loff_t pos;
809 unsigned int genid;
810 int valid;
811 };
812
813 static struct fib_alias *fib_get_first(struct seq_file *seq)
814 {
815 struct fib_iter_state *iter = seq->private;
816 struct fn_hash *table = (struct fn_hash *) ip_fib_main_table->tb_data;
817
818 iter->bucket = 0;
819 iter->hash_head = NULL;
820 iter->fn = NULL;
821 iter->fa = NULL;
822 iter->pos = 0;
823 iter->genid = fib_hash_genid;
824 iter->valid = 1;
825
826 for (iter->zone = table->fn_zone_list; iter->zone;
827 iter->zone = iter->zone->fz_next) {
828 int maxslot;
829
830 if (!iter->zone->fz_nent)
831 continue;
832
833 iter->hash_head = iter->zone->fz_hash;
834 maxslot = iter->zone->fz_divisor;
835
836 for (iter->bucket = 0; iter->bucket < maxslot;
837 ++iter->bucket, ++iter->hash_head) {
838 struct hlist_node *node;
839 struct fib_node *fn;
840
841 hlist_for_each_entry(fn,node,iter->hash_head,fn_hash) {
842 struct fib_alias *fa;
843
844 list_for_each_entry(fa,&fn->fn_alias,fa_list) {
845 iter->fn = fn;
846 iter->fa = fa;
847 goto out;
848 }
849 }
850 }
851 }
852 out:
853 return iter->fa;
854 }
855
856 static struct fib_alias *fib_get_next(struct seq_file *seq)
857 {
858 struct fib_iter_state *iter = seq->private;
859 struct fib_node *fn;
860 struct fib_alias *fa;
861
862 /* Advance FA, if any. */
863 fn = iter->fn;
864 fa = iter->fa;
865 if (fa) {
866 BUG_ON(!fn);
867 list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) {
868 iter->fa = fa;
869 goto out;
870 }
871 }
872
873 fa = iter->fa = NULL;
874
875 /* Advance FN. */
876 if (fn) {
877 struct hlist_node *node = &fn->fn_hash;
878 hlist_for_each_entry_continue(fn, node, fn_hash) {
879 iter->fn = fn;
880
881 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
882 iter->fa = fa;
883 goto out;
884 }
885 }
886 }
887
888 fn = iter->fn = NULL;
889
890 /* Advance hash chain. */
891 if (!iter->zone)
892 goto out;
893
894 for (;;) {
895 struct hlist_node *node;
896 int maxslot;
897
898 maxslot = iter->zone->fz_divisor;
899
900 while (++iter->bucket < maxslot) {
901 iter->hash_head++;
902
903 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
904 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
905 iter->fn = fn;
906 iter->fa = fa;
907 goto out;
908 }
909 }
910 }
911
912 iter->zone = iter->zone->fz_next;
913
914 if (!iter->zone)
915 goto out;
916
917 iter->bucket = 0;
918 iter->hash_head = iter->zone->fz_hash;
919
920 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
921 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
922 iter->fn = fn;
923 iter->fa = fa;
924 goto out;
925 }
926 }
927 }
928 out:
929 iter->pos++;
930 return fa;
931 }
932
933 static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos)
934 {
935 struct fib_iter_state *iter = seq->private;
936 struct fib_alias *fa;
937
938 if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) {
939 fa = iter->fa;
940 pos -= iter->pos;
941 } else
942 fa = fib_get_first(seq);
943
944 if (fa)
945 while (pos && (fa = fib_get_next(seq)))
946 --pos;
947 return pos ? NULL : fa;
948 }
949
950 static void *fib_seq_start(struct seq_file *seq, loff_t *pos)
951 {
952 void *v = NULL;
953
954 read_lock(&fib_hash_lock);
955 if (ip_fib_main_table)
956 v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
957 return v;
958 }
959
960 static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
961 {
962 ++*pos;
963 return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
964 }
965
966 static void fib_seq_stop(struct seq_file *seq, void *v)
967 {
968 read_unlock(&fib_hash_lock);
969 }
970
971 static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
972 {
973 static const unsigned type2flags[RTN_MAX + 1] = {
974 [7] = RTF_REJECT, [8] = RTF_REJECT,
975 };
976 unsigned flags = type2flags[type];
977
978 if (fi && fi->fib_nh->nh_gw)
979 flags |= RTF_GATEWAY;
980 if (mask == htonl(0xFFFFFFFF))
981 flags |= RTF_HOST;
982 flags |= RTF_UP;
983 return flags;
984 }
985
986 /*
987 * This outputs /proc/net/route.
988 *
989 * It always works in backward compatibility mode.
990 * The format of the file is not supposed to be changed.
991 */
992 static int fib_seq_show(struct seq_file *seq, void *v)
993 {
994 struct fib_iter_state *iter;
995 char bf[128];
996 __be32 prefix, mask;
997 unsigned flags;
998 struct fib_node *f;
999 struct fib_alias *fa;
1000 struct fib_info *fi;
1001
1002 if (v == SEQ_START_TOKEN) {
1003 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
1004 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
1005 "\tWindow\tIRTT");
1006 goto out;
1007 }
1008
1009 iter = seq->private;
1010 f = iter->fn;
1011 fa = iter->fa;
1012 fi = fa->fa_info;
1013 prefix = f->fn_key;
1014 mask = FZ_MASK(iter->zone);
1015 flags = fib_flag_trans(fa->fa_type, mask, fi);
1016 if (fi)
1017 snprintf(bf, sizeof(bf),
1018 "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
1019 fi->fib_dev ? fi->fib_dev->name : "*", prefix,
1020 fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
1021 mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
1022 fi->fib_window,
1023 fi->fib_rtt >> 3);
1024 else
1025 snprintf(bf, sizeof(bf),
1026 "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
1027 prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0);
1028 seq_printf(seq, "%-127s\n", bf);
1029 out:
1030 return 0;
1031 }
1032
1033 static const struct seq_operations fib_seq_ops = {
1034 .start = fib_seq_start,
1035 .next = fib_seq_next,
1036 .stop = fib_seq_stop,
1037 .show = fib_seq_show,
1038 };
1039
1040 static int fib_seq_open(struct inode *inode, struct file *file)
1041 {
1042 return seq_open_private(file, &fib_seq_ops,
1043 sizeof(struct fib_iter_state));
1044 }
1045
1046 static const struct file_operations fib_seq_fops = {
1047 .owner = THIS_MODULE,
1048 .open = fib_seq_open,
1049 .read = seq_read,
1050 .llseek = seq_lseek,
1051 .release = seq_release_private,
1052 };
1053
1054 int __init fib_proc_init(void)
1055 {
1056 if (!proc_net_fops_create(&init_net, "route", S_IRUGO, &fib_seq_fops))
1057 return -ENOMEM;
1058 return 0;
1059 }
1060
1061 void __init fib_proc_exit(void)
1062 {
1063 proc_net_remove(&init_net, "route");
1064 }
1065 #endif /* CONFIG_PROC_FS */
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