[NET] NETNS: Omit seq_net_private->net without CONFIG_NET_NS.
[linux-2.6.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(seq_file_net(seq), 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         void *v = NULL;
963
964         read_lock(&fib_hash_lock);
965         if (fib_get_table(seq_file_net(seq), RT_TABLE_MAIN))
966                 v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
967         return v;
968 }
969
970 static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
971 {
972         ++*pos;
973         return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
974 }
975
976 static void fib_seq_stop(struct seq_file *seq, void *v)
977         __releases(fib_hash_lock)
978 {
979         read_unlock(&fib_hash_lock);
980 }
981
982 static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
983 {
984         static const unsigned type2flags[RTN_MAX + 1] = {
985                 [7] = RTF_REJECT, [8] = RTF_REJECT,
986         };
987         unsigned flags = type2flags[type];
988
989         if (fi && fi->fib_nh->nh_gw)
990                 flags |= RTF_GATEWAY;
991         if (mask == htonl(0xFFFFFFFF))
992                 flags |= RTF_HOST;
993         flags |= RTF_UP;
994         return flags;
995 }
996
997 /*
998  *      This outputs /proc/net/route.
999  *
1000  *      It always works in backward compatibility mode.
1001  *      The format of the file is not supposed to be changed.
1002  */
1003 static int fib_seq_show(struct seq_file *seq, void *v)
1004 {
1005         struct fib_iter_state *iter;
1006         char bf[128];
1007         __be32 prefix, mask;
1008         unsigned flags;
1009         struct fib_node *f;
1010         struct fib_alias *fa;
1011         struct fib_info *fi;
1012
1013         if (v == SEQ_START_TOKEN) {
1014                 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
1015                            "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
1016                            "\tWindow\tIRTT");
1017                 goto out;
1018         }
1019
1020         iter    = seq->private;
1021         f       = iter->fn;
1022         fa      = iter->fa;
1023         fi      = fa->fa_info;
1024         prefix  = f->fn_key;
1025         mask    = FZ_MASK(iter->zone);
1026         flags   = fib_flag_trans(fa->fa_type, mask, fi);
1027         if (fi)
1028                 snprintf(bf, sizeof(bf),
1029                          "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
1030                          fi->fib_dev ? fi->fib_dev->name : "*", prefix,
1031                          fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
1032                          mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
1033                          fi->fib_window,
1034                          fi->fib_rtt >> 3);
1035         else
1036                 snprintf(bf, sizeof(bf),
1037                          "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
1038                          prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0);
1039         seq_printf(seq, "%-127s\n", bf);
1040 out:
1041         return 0;
1042 }
1043
1044 static const struct seq_operations fib_seq_ops = {
1045         .start  = fib_seq_start,
1046         .next   = fib_seq_next,
1047         .stop   = fib_seq_stop,
1048         .show   = fib_seq_show,
1049 };
1050
1051 static int fib_seq_open(struct inode *inode, struct file *file)
1052 {
1053         return seq_open_net(inode, file, &fib_seq_ops,
1054                             sizeof(struct fib_iter_state));
1055 }
1056
1057 static const struct file_operations fib_seq_fops = {
1058         .owner          = THIS_MODULE,
1059         .open           = fib_seq_open,
1060         .read           = seq_read,
1061         .llseek         = seq_lseek,
1062         .release        = seq_release_net,
1063 };
1064
1065 int __net_init fib_proc_init(struct net *net)
1066 {
1067         if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_seq_fops))
1068                 return -ENOMEM;
1069         return 0;
1070 }
1071
1072 void __net_exit fib_proc_exit(struct net *net)
1073 {
1074         proc_net_remove(net, "route");
1075 }
1076 #endif /* CONFIG_PROC_FS */