Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
[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  * 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
36 #include <net/net_namespace.h>
37 #include <net/ip.h>
38 #include <net/protocol.h>
39 #include <net/route.h>
40 #include <net/tcp.h>
41 #include <net/sock.h>
42 #include <net/ip_fib.h>
43
44 #include "fib_lookup.h"
45
46 static struct kmem_cache *fn_hash_kmem __read_mostly;
47 static struct kmem_cache *fn_alias_kmem __read_mostly;
48
49 struct fib_node {
50         struct hlist_node       fn_hash;
51         struct list_head        fn_alias;
52         __be32                  fn_key;
53         struct fib_alias        fn_embedded_alias;
54 };
55
56 struct fn_zone {
57         struct fn_zone          *fz_next;       /* Next not empty zone  */
58         struct hlist_head       *fz_hash;       /* Hash table pointer   */
59         int                     fz_nent;        /* Number of entries    */
60
61         int                     fz_divisor;     /* Hash divisor         */
62         u32                     fz_hashmask;    /* (fz_divisor - 1)     */
63 #define FZ_HASHMASK(fz)         ((fz)->fz_hashmask)
64
65         int                     fz_order;       /* Zone order           */
66         __be32                  fz_mask;
67 #define FZ_MASK(fz)             ((fz)->fz_mask)
68 };
69
70 /* NOTE. On fast computers evaluation of fz_hashmask and fz_mask
71  * can be cheaper than memory lookup, so that FZ_* macros are used.
72  */
73
74 struct fn_hash {
75         struct fn_zone  *fn_zones[33];
76         struct fn_zone  *fn_zone_list;
77 };
78
79 static inline u32 fn_hash(__be32 key, struct fn_zone *fz)
80 {
81         u32 h = ntohl(key)>>(32 - fz->fz_order);
82         h ^= (h>>20);
83         h ^= (h>>10);
84         h ^= (h>>5);
85         h &= FZ_HASHMASK(fz);
86         return h;
87 }
88
89 static inline __be32 fz_key(__be32 dst, struct fn_zone *fz)
90 {
91         return dst & FZ_MASK(fz);
92 }
93
94 static DEFINE_RWLOCK(fib_hash_lock);
95 static unsigned int fib_hash_genid;
96
97 #define FZ_MAX_DIVISOR ((PAGE_SIZE<<MAX_ORDER) / sizeof(struct hlist_head))
98
99 static struct hlist_head *fz_hash_alloc(int divisor)
100 {
101         unsigned long size = divisor * sizeof(struct hlist_head);
102
103         if (size <= PAGE_SIZE) {
104                 return kzalloc(size, GFP_KERNEL);
105         } else {
106                 return (struct hlist_head *)
107                         __get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(size));
108         }
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(&f->fn_hash);
126
127                         new_head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
128                         hlist_add_head(&f->fn_hash, new_head);
129                 }
130         }
131 }
132
133 static void fz_hash_free(struct hlist_head *hash, int divisor)
134 {
135         unsigned long size = divisor * sizeof(struct hlist_head);
136
137         if (size <= PAGE_SIZE)
138                 kfree(hash);
139         else
140                 free_pages((unsigned long)hash, get_order(size));
141 }
142
143 static void fn_rehash_zone(struct fn_zone *fz)
144 {
145         struct hlist_head *ht, *old_ht;
146         int old_divisor, new_divisor;
147         u32 new_hashmask;
148
149         old_divisor = fz->fz_divisor;
150
151         switch (old_divisor) {
152         case 16:
153                 new_divisor = 256;
154                 break;
155         case 256:
156                 new_divisor = 1024;
157                 break;
158         default:
159                 if ((old_divisor << 1) > FZ_MAX_DIVISOR) {
160                         printk(KERN_CRIT "route.c: bad divisor %d!\n", old_divisor);
161                         return;
162                 }
163                 new_divisor = (old_divisor << 1);
164                 break;
165         }
166
167         new_hashmask = (new_divisor - 1);
168
169 #if RT_CACHE_DEBUG >= 2
170         printk(KERN_DEBUG "fn_rehash_zone: hash for zone %d grows from %d\n",
171                fz->fz_order, old_divisor);
172 #endif
173
174         ht = fz_hash_alloc(new_divisor);
175
176         if (ht) {
177                 write_lock_bh(&fib_hash_lock);
178                 old_ht = fz->fz_hash;
179                 fz->fz_hash = ht;
180                 fz->fz_hashmask = new_hashmask;
181                 fz->fz_divisor = new_divisor;
182                 fn_rebuild_zone(fz, old_ht, old_divisor);
183                 fib_hash_genid++;
184                 write_unlock_bh(&fib_hash_lock);
185
186                 fz_hash_free(old_ht, old_divisor);
187         }
188 }
189
190 static inline void fn_free_node(struct fib_node * f)
191 {
192         kmem_cache_free(fn_hash_kmem, f);
193 }
194
195 static inline void fn_free_alias(struct fib_alias *fa, struct fib_node *f)
196 {
197         fib_release_info(fa->fa_info);
198         if (fa == &f->fn_embedded_alias)
199                 fa->fa_info = NULL;
200         else
201                 kmem_cache_free(fn_alias_kmem, fa);
202 }
203
204 static struct fn_zone *
205 fn_new_zone(struct fn_hash *table, int z)
206 {
207         int i;
208         struct fn_zone *fz = kzalloc(sizeof(struct fn_zone), GFP_KERNEL);
209         if (!fz)
210                 return NULL;
211
212         if (z) {
213                 fz->fz_divisor = 16;
214         } else {
215                 fz->fz_divisor = 1;
216         }
217         fz->fz_hashmask = (fz->fz_divisor - 1);
218         fz->fz_hash = fz_hash_alloc(fz->fz_divisor);
219         if (!fz->fz_hash) {
220                 kfree(fz);
221                 return NULL;
222         }
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 int fib_table_lookup(struct fib_table *tb,
246                      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                                                  fz->fz_order);
267                         if (err <= 0)
268                                 goto out;
269                 }
270         }
271         err = 1;
272 out:
273         read_unlock(&fib_hash_lock);
274         return err;
275 }
276
277 void fib_table_select_default(struct fib_table *tb,
278                               const struct flowi *flp, struct fib_result *res)
279 {
280         int order, last_idx;
281         struct hlist_node *node;
282         struct fib_node *f;
283         struct fib_info *fi = NULL;
284         struct fib_info *last_resort;
285         struct fn_hash *t = (struct fn_hash *)tb->tb_data;
286         struct fn_zone *fz = t->fn_zones[0];
287
288         if (fz == NULL)
289                 return;
290
291         last_idx = -1;
292         last_resort = NULL;
293         order = -1;
294
295         read_lock(&fib_hash_lock);
296         hlist_for_each_entry(f, node, &fz->fz_hash[0], fn_hash) {
297                 struct fib_alias *fa;
298
299                 list_for_each_entry(fa, &f->fn_alias, fa_list) {
300                         struct fib_info *next_fi = fa->fa_info;
301
302                         if (fa->fa_scope != res->scope ||
303                             fa->fa_type != RTN_UNICAST)
304                                 continue;
305
306                         if (next_fi->fib_priority > res->fi->fib_priority)
307                                 break;
308                         if (!next_fi->fib_nh[0].nh_gw ||
309                             next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
310                                 continue;
311                         fa->fa_state |= FA_S_ACCESSED;
312
313                         if (fi == NULL) {
314                                 if (next_fi != res->fi)
315                                         break;
316                         } else if (!fib_detect_death(fi, order, &last_resort,
317                                                 &last_idx, tb->tb_default)) {
318                                 fib_result_assign(res, fi);
319                                 tb->tb_default = order;
320                                 goto out;
321                         }
322                         fi = next_fi;
323                         order++;
324                 }
325         }
326
327         if (order <= 0 || fi == NULL) {
328                 tb->tb_default = -1;
329                 goto out;
330         }
331
332         if (!fib_detect_death(fi, order, &last_resort, &last_idx,
333                                 tb->tb_default)) {
334                 fib_result_assign(res, fi);
335                 tb->tb_default = order;
336                 goto out;
337         }
338
339         if (last_idx >= 0)
340                 fib_result_assign(res, last_resort);
341         tb->tb_default = last_idx;
342 out:
343         read_unlock(&fib_hash_lock);
344 }
345
346 /* Insert node F to FZ. */
347 static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
348 {
349         struct hlist_head *head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
350
351         hlist_add_head(&f->fn_hash, head);
352 }
353
354 /* Return the node in FZ matching KEY. */
355 static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key)
356 {
357         struct hlist_head *head = &fz->fz_hash[fn_hash(key, fz)];
358         struct hlist_node *node;
359         struct fib_node *f;
360
361         hlist_for_each_entry(f, node, head, fn_hash) {
362                 if (f->fn_key == key)
363                         return f;
364         }
365
366         return NULL;
367 }
368
369 int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
370 {
371         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
372         struct fib_node *new_f = NULL;
373         struct fib_node *f;
374         struct fib_alias *fa, *new_fa;
375         struct fn_zone *fz;
376         struct fib_info *fi;
377         u8 tos = cfg->fc_tos;
378         __be32 key;
379         int err;
380
381         if (cfg->fc_dst_len > 32)
382                 return -EINVAL;
383
384         fz = table->fn_zones[cfg->fc_dst_len];
385         if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len)))
386                 return -ENOBUFS;
387
388         key = 0;
389         if (cfg->fc_dst) {
390                 if (cfg->fc_dst & ~FZ_MASK(fz))
391                         return -EINVAL;
392                 key = fz_key(cfg->fc_dst, fz);
393         }
394
395         fi = fib_create_info(cfg);
396         if (IS_ERR(fi))
397                 return PTR_ERR(fi);
398
399         if (fz->fz_nent > (fz->fz_divisor<<1) &&
400             fz->fz_divisor < FZ_MAX_DIVISOR &&
401             (cfg->fc_dst_len == 32 ||
402              (1 << cfg->fc_dst_len) > fz->fz_divisor))
403                 fn_rehash_zone(fz);
404
405         f = fib_find_node(fz, key);
406
407         if (!f)
408                 fa = NULL;
409         else
410                 fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority);
411
412         /* Now fa, if non-NULL, points to the first fib alias
413          * with the same keys [prefix,tos,priority], if such key already
414          * exists or to the node before which we will insert new one.
415          *
416          * If fa is NULL, we will need to allocate a new one and
417          * insert to the head of f.
418          *
419          * If f is NULL, no fib node matched the destination key
420          * and we need to allocate a new one of those as well.
421          */
422
423         if (fa && fa->fa_tos == tos &&
424             fa->fa_info->fib_priority == fi->fib_priority) {
425                 struct fib_alias *fa_first, *fa_match;
426
427                 err = -EEXIST;
428                 if (cfg->fc_nlflags & NLM_F_EXCL)
429                         goto out;
430
431                 /* We have 2 goals:
432                  * 1. Find exact match for type, scope, fib_info to avoid
433                  * duplicate routes
434                  * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
435                  */
436                 fa_match = NULL;
437                 fa_first = fa;
438                 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
439                 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
440                         if (fa->fa_tos != tos)
441                                 break;
442                         if (fa->fa_info->fib_priority != fi->fib_priority)
443                                 break;
444                         if (fa->fa_type == cfg->fc_type &&
445                             fa->fa_scope == cfg->fc_scope &&
446                             fa->fa_info == fi) {
447                                 fa_match = fa;
448                                 break;
449                         }
450                 }
451
452                 if (cfg->fc_nlflags & NLM_F_REPLACE) {
453                         struct fib_info *fi_drop;
454                         u8 state;
455
456                         fa = fa_first;
457                         if (fa_match) {
458                                 if (fa == fa_match)
459                                         err = 0;
460                                 goto out;
461                         }
462                         write_lock_bh(&fib_hash_lock);
463                         fi_drop = fa->fa_info;
464                         fa->fa_info = fi;
465                         fa->fa_type = cfg->fc_type;
466                         fa->fa_scope = cfg->fc_scope;
467                         state = fa->fa_state;
468                         fa->fa_state &= ~FA_S_ACCESSED;
469                         fib_hash_genid++;
470                         write_unlock_bh(&fib_hash_lock);
471
472                         fib_release_info(fi_drop);
473                         if (state & FA_S_ACCESSED)
474                                 rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
475                         rtmsg_fib(RTM_NEWROUTE, key, fa, cfg->fc_dst_len, tb->tb_id,
476                                   &cfg->fc_nlinfo, NLM_F_REPLACE);
477                         return 0;
478                 }
479
480                 /* Error if we find a perfect match which
481                  * uses the same scope, type, and nexthop
482                  * information.
483                  */
484                 if (fa_match)
485                         goto out;
486
487                 if (!(cfg->fc_nlflags & NLM_F_APPEND))
488                         fa = fa_first;
489         }
490
491         err = -ENOENT;
492         if (!(cfg->fc_nlflags & NLM_F_CREATE))
493                 goto out;
494
495         err = -ENOBUFS;
496
497         if (!f) {
498                 new_f = kmem_cache_zalloc(fn_hash_kmem, GFP_KERNEL);
499                 if (new_f == NULL)
500                         goto out;
501
502                 INIT_HLIST_NODE(&new_f->fn_hash);
503                 INIT_LIST_HEAD(&new_f->fn_alias);
504                 new_f->fn_key = key;
505                 f = new_f;
506         }
507
508         new_fa = &f->fn_embedded_alias;
509         if (new_fa->fa_info != NULL) {
510                 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
511                 if (new_fa == NULL)
512                         goto out;
513         }
514         new_fa->fa_info = fi;
515         new_fa->fa_tos = tos;
516         new_fa->fa_type = cfg->fc_type;
517         new_fa->fa_scope = cfg->fc_scope;
518         new_fa->fa_state = 0;
519
520         /*
521          * Insert new entry to the list.
522          */
523
524         write_lock_bh(&fib_hash_lock);
525         if (new_f)
526                 fib_insert_node(fz, new_f);
527         list_add_tail(&new_fa->fa_list,
528                  (fa ? &fa->fa_list : &f->fn_alias));
529         fib_hash_genid++;
530         write_unlock_bh(&fib_hash_lock);
531
532         if (new_f)
533                 fz->fz_nent++;
534         rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
535
536         rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id,
537                   &cfg->fc_nlinfo, 0);
538         return 0;
539
540 out:
541         if (new_f)
542                 kmem_cache_free(fn_hash_kmem, new_f);
543         fib_release_info(fi);
544         return err;
545 }
546
547 int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
548 {
549         struct fn_hash *table = (struct fn_hash *)tb->tb_data;
550         struct fib_node *f;
551         struct fib_alias *fa, *fa_to_delete;
552         struct fn_zone *fz;
553         __be32 key;
554
555         if (cfg->fc_dst_len > 32)
556                 return -EINVAL;
557
558         if ((fz  = table->fn_zones[cfg->fc_dst_len]) == NULL)
559                 return -ESRCH;
560
561         key = 0;
562         if (cfg->fc_dst) {
563                 if (cfg->fc_dst & ~FZ_MASK(fz))
564                         return -EINVAL;
565                 key = fz_key(cfg->fc_dst, fz);
566         }
567
568         f = fib_find_node(fz, key);
569
570         if (!f)
571                 fa = NULL;
572         else
573                 fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0);
574         if (!fa)
575                 return -ESRCH;
576
577         fa_to_delete = NULL;
578         fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
579         list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
580                 struct fib_info *fi = fa->fa_info;
581
582                 if (fa->fa_tos != cfg->fc_tos)
583                         break;
584
585                 if ((!cfg->fc_type ||
586                      fa->fa_type == cfg->fc_type) &&
587                     (cfg->fc_scope == RT_SCOPE_NOWHERE ||
588                      fa->fa_scope == cfg->fc_scope) &&
589                     (!cfg->fc_protocol ||
590                      fi->fib_protocol == cfg->fc_protocol) &&
591                     fib_nh_match(cfg, fi) == 0) {
592                         fa_to_delete = fa;
593                         break;
594                 }
595         }
596
597         if (fa_to_delete) {
598                 int kill_fn;
599
600                 fa = fa_to_delete;
601                 rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len,
602                           tb->tb_id, &cfg->fc_nlinfo, 0);
603
604                 kill_fn = 0;
605                 write_lock_bh(&fib_hash_lock);
606                 list_del(&fa->fa_list);
607                 if (list_empty(&f->fn_alias)) {
608                         hlist_del(&f->fn_hash);
609                         kill_fn = 1;
610                 }
611                 fib_hash_genid++;
612                 write_unlock_bh(&fib_hash_lock);
613
614                 if (fa->fa_state & FA_S_ACCESSED)
615                         rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
616                 fn_free_alias(fa, f);
617                 if (kill_fn) {
618                         fn_free_node(f);
619                         fz->fz_nent--;
620                 }
621
622                 return 0;
623         }
624         return -ESRCH;
625 }
626
627 static int fn_flush_list(struct fn_zone *fz, int idx)
628 {
629         struct hlist_head *head = &fz->fz_hash[idx];
630         struct hlist_node *node, *n;
631         struct fib_node *f;
632         int found = 0;
633
634         hlist_for_each_entry_safe(f, node, n, head, fn_hash) {
635                 struct fib_alias *fa, *fa_node;
636                 int kill_f;
637
638                 kill_f = 0;
639                 list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) {
640                         struct fib_info *fi = fa->fa_info;
641
642                         if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
643                                 write_lock_bh(&fib_hash_lock);
644                                 list_del(&fa->fa_list);
645                                 if (list_empty(&f->fn_alias)) {
646                                         hlist_del(&f->fn_hash);
647                                         kill_f = 1;
648                                 }
649                                 fib_hash_genid++;
650                                 write_unlock_bh(&fib_hash_lock);
651
652                                 fn_free_alias(fa, f);
653                                 found++;
654                         }
655                 }
656                 if (kill_f) {
657                         fn_free_node(f);
658                         fz->fz_nent--;
659                 }
660         }
661         return found;
662 }
663
664 int fib_table_flush(struct fib_table *tb)
665 {
666         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
667         struct fn_zone *fz;
668         int found = 0;
669
670         for (fz = table->fn_zone_list; fz; fz = fz->fz_next) {
671                 int i;
672
673                 for (i = fz->fz_divisor - 1; i >= 0; i--)
674                         found += fn_flush_list(fz, i);
675         }
676         return found;
677 }
678
679
680 static inline int
681 fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
682                      struct fib_table *tb,
683                      struct fn_zone *fz,
684                      struct hlist_head *head)
685 {
686         struct hlist_node *node;
687         struct fib_node *f;
688         int i, s_i;
689
690         s_i = cb->args[4];
691         i = 0;
692         hlist_for_each_entry(f, node, head, fn_hash) {
693                 struct fib_alias *fa;
694
695                 list_for_each_entry(fa, &f->fn_alias, fa_list) {
696                         if (i < s_i)
697                                 goto next;
698
699                         if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
700                                           cb->nlh->nlmsg_seq,
701                                           RTM_NEWROUTE,
702                                           tb->tb_id,
703                                           fa->fa_type,
704                                           fa->fa_scope,
705                                           f->fn_key,
706                                           fz->fz_order,
707                                           fa->fa_tos,
708                                           fa->fa_info,
709                                           NLM_F_MULTI) < 0) {
710                                 cb->args[4] = i;
711                                 return -1;
712                         }
713                 next:
714                         i++;
715                 }
716         }
717         cb->args[4] = i;
718         return skb->len;
719 }
720
721 static inline int
722 fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
723                    struct fib_table *tb,
724                    struct fn_zone *fz)
725 {
726         int h, s_h;
727
728         if (fz->fz_hash == NULL)
729                 return skb->len;
730         s_h = cb->args[3];
731         for (h = s_h; h < fz->fz_divisor; h++) {
732                 if (hlist_empty(&fz->fz_hash[h]))
733                         continue;
734                 if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h]) < 0) {
735                         cb->args[3] = h;
736                         return -1;
737                 }
738                 memset(&cb->args[4], 0,
739                        sizeof(cb->args) - 4*sizeof(cb->args[0]));
740         }
741         cb->args[3] = h;
742         return skb->len;
743 }
744
745 int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
746                    struct netlink_callback *cb)
747 {
748         int m, s_m;
749         struct fn_zone *fz;
750         struct fn_hash *table = (struct fn_hash *)tb->tb_data;
751
752         s_m = cb->args[2];
753         read_lock(&fib_hash_lock);
754         for (fz = table->fn_zone_list, m=0; fz; fz = fz->fz_next, m++) {
755                 if (m < s_m) continue;
756                 if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
757                         cb->args[2] = m;
758                         read_unlock(&fib_hash_lock);
759                         return -1;
760                 }
761                 memset(&cb->args[3], 0,
762                        sizeof(cb->args) - 3*sizeof(cb->args[0]));
763         }
764         read_unlock(&fib_hash_lock);
765         cb->args[2] = m;
766         return skb->len;
767 }
768
769 void __init fib_hash_init(void)
770 {
771         fn_hash_kmem = kmem_cache_create("ip_fib_hash", sizeof(struct fib_node),
772                                          0, SLAB_PANIC, NULL);
773
774         fn_alias_kmem = kmem_cache_create("ip_fib_alias", sizeof(struct fib_alias),
775                                           0, SLAB_PANIC, NULL);
776
777 }
778
779 struct fib_table *fib_hash_table(u32 id)
780 {
781         struct fib_table *tb;
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_default = -1;
790
791         memset(tb->tb_data, 0, sizeof(struct fn_hash));
792         return tb;
793 }
794
795 /* ------------------------------------------------------------------------ */
796 #ifdef CONFIG_PROC_FS
797
798 struct fib_iter_state {
799         struct seq_net_private p;
800         struct fn_zone  *zone;
801         int             bucket;
802         struct hlist_head *hash_head;
803         struct fib_node *fn;
804         struct fib_alias *fa;
805         loff_t pos;
806         unsigned int genid;
807         int valid;
808 };
809
810 static struct fib_alias *fib_get_first(struct seq_file *seq)
811 {
812         struct fib_iter_state *iter = seq->private;
813         struct fib_table *main_table;
814         struct fn_hash *table;
815
816         main_table = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
817         table = (struct fn_hash *)main_table->tb_data;
818
819         iter->bucket    = 0;
820         iter->hash_head = NULL;
821         iter->fn        = NULL;
822         iter->fa        = NULL;
823         iter->pos       = 0;
824         iter->genid     = fib_hash_genid;
825         iter->valid     = 1;
826
827         for (iter->zone = table->fn_zone_list; iter->zone;
828              iter->zone = iter->zone->fz_next) {
829                 int maxslot;
830
831                 if (!iter->zone->fz_nent)
832                         continue;
833
834                 iter->hash_head = iter->zone->fz_hash;
835                 maxslot = iter->zone->fz_divisor;
836
837                 for (iter->bucket = 0; iter->bucket < maxslot;
838                      ++iter->bucket, ++iter->hash_head) {
839                         struct hlist_node *node;
840                         struct fib_node *fn;
841
842                         hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
843                                 struct fib_alias *fa;
844
845                                 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
846                                         iter->fn = fn;
847                                         iter->fa = fa;
848                                         goto out;
849                                 }
850                         }
851                 }
852         }
853 out:
854         return iter->fa;
855 }
856
857 static struct fib_alias *fib_get_next(struct seq_file *seq)
858 {
859         struct fib_iter_state *iter = seq->private;
860         struct fib_node *fn;
861         struct fib_alias *fa;
862
863         /* Advance FA, if any. */
864         fn = iter->fn;
865         fa = iter->fa;
866         if (fa) {
867                 BUG_ON(!fn);
868                 list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) {
869                         iter->fa = fa;
870                         goto out;
871                 }
872         }
873
874         fa = iter->fa = NULL;
875
876         /* Advance FN. */
877         if (fn) {
878                 struct hlist_node *node = &fn->fn_hash;
879                 hlist_for_each_entry_continue(fn, node, fn_hash) {
880                         iter->fn = fn;
881
882                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
883                                 iter->fa = fa;
884                                 goto out;
885                         }
886                 }
887         }
888
889         fn = iter->fn = NULL;
890
891         /* Advance hash chain. */
892         if (!iter->zone)
893                 goto out;
894
895         for (;;) {
896                 struct hlist_node *node;
897                 int maxslot;
898
899                 maxslot = iter->zone->fz_divisor;
900
901                 while (++iter->bucket < maxslot) {
902                         iter->hash_head++;
903
904                         hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
905                                 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
906                                         iter->fn = fn;
907                                         iter->fa = fa;
908                                         goto out;
909                                 }
910                         }
911                 }
912
913                 iter->zone = iter->zone->fz_next;
914
915                 if (!iter->zone)
916                         goto out;
917
918                 iter->bucket = 0;
919                 iter->hash_head = iter->zone->fz_hash;
920
921                 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
922                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
923                                 iter->fn = fn;
924                                 iter->fa = fa;
925                                 goto out;
926                         }
927                 }
928         }
929 out:
930         iter->pos++;
931         return fa;
932 }
933
934 static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos)
935 {
936         struct fib_iter_state *iter = seq->private;
937         struct fib_alias *fa;
938
939         if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) {
940                 fa   = iter->fa;
941                 pos -= iter->pos;
942         } else
943                 fa = fib_get_first(seq);
944
945         if (fa)
946                 while (pos && (fa = fib_get_next(seq)))
947                         --pos;
948         return pos ? NULL : fa;
949 }
950
951 static void *fib_seq_start(struct seq_file *seq, loff_t *pos)
952         __acquires(fib_hash_lock)
953 {
954         void *v = NULL;
955
956         read_lock(&fib_hash_lock);
957         if (fib_get_table(seq_file_net(seq), RT_TABLE_MAIN))
958                 v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
959         return v;
960 }
961
962 static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
963 {
964         ++*pos;
965         return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
966 }
967
968 static void fib_seq_stop(struct seq_file *seq, void *v)
969         __releases(fib_hash_lock)
970 {
971         read_unlock(&fib_hash_lock);
972 }
973
974 static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
975 {
976         static const unsigned type2flags[RTN_MAX + 1] = {
977                 [7] = RTF_REJECT, [8] = RTF_REJECT,
978         };
979         unsigned flags = type2flags[type];
980
981         if (fi && fi->fib_nh->nh_gw)
982                 flags |= RTF_GATEWAY;
983         if (mask == htonl(0xFFFFFFFF))
984                 flags |= RTF_HOST;
985         flags |= RTF_UP;
986         return flags;
987 }
988
989 /*
990  *      This outputs /proc/net/route.
991  *
992  *      It always works in backward compatibility mode.
993  *      The format of the file is not supposed to be changed.
994  */
995 static int fib_seq_show(struct seq_file *seq, void *v)
996 {
997         struct fib_iter_state *iter;
998         int len;
999         __be32 prefix, mask;
1000         unsigned flags;
1001         struct fib_node *f;
1002         struct fib_alias *fa;
1003         struct fib_info *fi;
1004
1005         if (v == SEQ_START_TOKEN) {
1006                 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
1007                            "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
1008                            "\tWindow\tIRTT");
1009                 goto out;
1010         }
1011
1012         iter    = seq->private;
1013         f       = iter->fn;
1014         fa      = iter->fa;
1015         fi      = fa->fa_info;
1016         prefix  = f->fn_key;
1017         mask    = FZ_MASK(iter->zone);
1018         flags   = fib_flag_trans(fa->fa_type, mask, fi);
1019         if (fi)
1020                 seq_printf(seq,
1021                          "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
1022                          fi->fib_dev ? fi->fib_dev->name : "*", prefix,
1023                          fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
1024                          mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
1025                          fi->fib_window,
1026                          fi->fib_rtt >> 3, &len);
1027         else
1028                 seq_printf(seq,
1029                          "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
1030                          prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0, &len);
1031
1032         seq_printf(seq, "%*s\n", 127 - len, "");
1033 out:
1034         return 0;
1035 }
1036
1037 static const struct seq_operations fib_seq_ops = {
1038         .start  = fib_seq_start,
1039         .next   = fib_seq_next,
1040         .stop   = fib_seq_stop,
1041         .show   = fib_seq_show,
1042 };
1043
1044 static int fib_seq_open(struct inode *inode, struct file *file)
1045 {
1046         return seq_open_net(inode, file, &fib_seq_ops,
1047                             sizeof(struct fib_iter_state));
1048 }
1049
1050 static const struct file_operations fib_seq_fops = {
1051         .owner          = THIS_MODULE,
1052         .open           = fib_seq_open,
1053         .read           = seq_read,
1054         .llseek         = seq_lseek,
1055         .release        = seq_release_net,
1056 };
1057
1058 int __net_init fib_proc_init(struct net *net)
1059 {
1060         if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_seq_fops))
1061                 return -ENOMEM;
1062         return 0;
1063 }
1064
1065 void __net_exit fib_proc_exit(struct net *net)
1066 {
1067         proc_net_remove(net, "route");
1068 }
1069 #endif /* CONFIG_PROC_FS */