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[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 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                                                  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 static void
278 fn_hash_select_default(struct fib_table *tb, 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 static int fn_hash_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
548 static int fn_hash_delete(struct fib_table *tb, struct fib_config *cfg)
549 {
550         struct fn_hash *table = (struct fn_hash *)tb->tb_data;
551         struct fib_node *f;
552         struct fib_alias *fa, *fa_to_delete;
553         struct fn_zone *fz;
554         __be32 key;
555
556         if (cfg->fc_dst_len > 32)
557                 return -EINVAL;
558
559         if ((fz  = table->fn_zones[cfg->fc_dst_len]) == NULL)
560                 return -ESRCH;
561
562         key = 0;
563         if (cfg->fc_dst) {
564                 if (cfg->fc_dst & ~FZ_MASK(fz))
565                         return -EINVAL;
566                 key = fz_key(cfg->fc_dst, fz);
567         }
568
569         f = fib_find_node(fz, key);
570
571         if (!f)
572                 fa = NULL;
573         else
574                 fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0);
575         if (!fa)
576                 return -ESRCH;
577
578         fa_to_delete = NULL;
579         fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
580         list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
581                 struct fib_info *fi = fa->fa_info;
582
583                 if (fa->fa_tos != cfg->fc_tos)
584                         break;
585
586                 if ((!cfg->fc_type ||
587                      fa->fa_type == cfg->fc_type) &&
588                     (cfg->fc_scope == RT_SCOPE_NOWHERE ||
589                      fa->fa_scope == cfg->fc_scope) &&
590                     (!cfg->fc_protocol ||
591                      fi->fib_protocol == cfg->fc_protocol) &&
592                     fib_nh_match(cfg, fi) == 0) {
593                         fa_to_delete = fa;
594                         break;
595                 }
596         }
597
598         if (fa_to_delete) {
599                 int kill_fn;
600
601                 fa = fa_to_delete;
602                 rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len,
603                           tb->tb_id, &cfg->fc_nlinfo, 0);
604
605                 kill_fn = 0;
606                 write_lock_bh(&fib_hash_lock);
607                 list_del(&fa->fa_list);
608                 if (list_empty(&f->fn_alias)) {
609                         hlist_del(&f->fn_hash);
610                         kill_fn = 1;
611                 }
612                 fib_hash_genid++;
613                 write_unlock_bh(&fib_hash_lock);
614
615                 if (fa->fa_state & FA_S_ACCESSED)
616                         rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
617                 fn_free_alias(fa, f);
618                 if (kill_fn) {
619                         fn_free_node(f);
620                         fz->fz_nent--;
621                 }
622
623                 return 0;
624         }
625         return -ESRCH;
626 }
627
628 static int fn_flush_list(struct fn_zone *fz, int idx)
629 {
630         struct hlist_head *head = &fz->fz_hash[idx];
631         struct hlist_node *node, *n;
632         struct fib_node *f;
633         int found = 0;
634
635         hlist_for_each_entry_safe(f, node, n, head, fn_hash) {
636                 struct fib_alias *fa, *fa_node;
637                 int kill_f;
638
639                 kill_f = 0;
640                 list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) {
641                         struct fib_info *fi = fa->fa_info;
642
643                         if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
644                                 write_lock_bh(&fib_hash_lock);
645                                 list_del(&fa->fa_list);
646                                 if (list_empty(&f->fn_alias)) {
647                                         hlist_del(&f->fn_hash);
648                                         kill_f = 1;
649                                 }
650                                 fib_hash_genid++;
651                                 write_unlock_bh(&fib_hash_lock);
652
653                                 fn_free_alias(fa, f);
654                                 found++;
655                         }
656                 }
657                 if (kill_f) {
658                         fn_free_node(f);
659                         fz->fz_nent--;
660                 }
661         }
662         return found;
663 }
664
665 static int fn_hash_flush(struct fib_table *tb)
666 {
667         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
668         struct fn_zone *fz;
669         int found = 0;
670
671         for (fz = table->fn_zone_list; fz; fz = fz->fz_next) {
672                 int i;
673
674                 for (i = fz->fz_divisor - 1; i >= 0; i--)
675                         found += fn_flush_list(fz, i);
676         }
677         return found;
678 }
679
680
681 static inline int
682 fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
683                      struct fib_table *tb,
684                      struct fn_zone *fz,
685                      struct hlist_head *head)
686 {
687         struct hlist_node *node;
688         struct fib_node *f;
689         int i, s_i;
690
691         s_i = cb->args[4];
692         i = 0;
693         hlist_for_each_entry(f, node, head, fn_hash) {
694                 struct fib_alias *fa;
695
696                 list_for_each_entry(fa, &f->fn_alias, fa_list) {
697                         if (i < s_i)
698                                 goto next;
699
700                         if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
701                                           cb->nlh->nlmsg_seq,
702                                           RTM_NEWROUTE,
703                                           tb->tb_id,
704                                           fa->fa_type,
705                                           fa->fa_scope,
706                                           f->fn_key,
707                                           fz->fz_order,
708                                           fa->fa_tos,
709                                           fa->fa_info,
710                                           NLM_F_MULTI) < 0) {
711                                 cb->args[4] = i;
712                                 return -1;
713                         }
714                 next:
715                         i++;
716                 }
717         }
718         cb->args[4] = i;
719         return skb->len;
720 }
721
722 static inline int
723 fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
724                    struct fib_table *tb,
725                    struct fn_zone *fz)
726 {
727         int h, s_h;
728
729         if (fz->fz_hash == NULL)
730                 return skb->len;
731         s_h = cb->args[3];
732         for (h = s_h; h < fz->fz_divisor; h++) {
733                 if (hlist_empty(&fz->fz_hash[h]))
734                         continue;
735                 if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h]) < 0) {
736                         cb->args[3] = h;
737                         return -1;
738                 }
739                 memset(&cb->args[4], 0,
740                        sizeof(cb->args) - 4*sizeof(cb->args[0]));
741         }
742         cb->args[3] = h;
743         return skb->len;
744 }
745
746 static int fn_hash_dump(struct fib_table *tb, struct sk_buff *skb, 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         tb->tb_lookup = fn_hash_lookup;
791         tb->tb_insert = fn_hash_insert;
792         tb->tb_delete = fn_hash_delete;
793         tb->tb_flush = fn_hash_flush;
794         tb->tb_select_default = fn_hash_select_default;
795         tb->tb_dump = fn_hash_dump;
796         memset(tb->tb_data, 0, sizeof(struct fn_hash));
797         return tb;
798 }
799
800 /* ------------------------------------------------------------------------ */
801 #ifdef CONFIG_PROC_FS
802
803 struct fib_iter_state {
804         struct seq_net_private p;
805         struct fn_zone  *zone;
806         int             bucket;
807         struct hlist_head *hash_head;
808         struct fib_node *fn;
809         struct fib_alias *fa;
810         loff_t pos;
811         unsigned int genid;
812         int valid;
813 };
814
815 static struct fib_alias *fib_get_first(struct seq_file *seq)
816 {
817         struct fib_iter_state *iter = seq->private;
818         struct fib_table *main_table;
819         struct fn_hash *table;
820
821         main_table = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
822         table = (struct fn_hash *)main_table->tb_data;
823
824         iter->bucket    = 0;
825         iter->hash_head = NULL;
826         iter->fn        = NULL;
827         iter->fa        = NULL;
828         iter->pos       = 0;
829         iter->genid     = fib_hash_genid;
830         iter->valid     = 1;
831
832         for (iter->zone = table->fn_zone_list; iter->zone;
833              iter->zone = iter->zone->fz_next) {
834                 int maxslot;
835
836                 if (!iter->zone->fz_nent)
837                         continue;
838
839                 iter->hash_head = iter->zone->fz_hash;
840                 maxslot = iter->zone->fz_divisor;
841
842                 for (iter->bucket = 0; iter->bucket < maxslot;
843                      ++iter->bucket, ++iter->hash_head) {
844                         struct hlist_node *node;
845                         struct fib_node *fn;
846
847                         hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
848                                 struct fib_alias *fa;
849
850                                 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
851                                         iter->fn = fn;
852                                         iter->fa = fa;
853                                         goto out;
854                                 }
855                         }
856                 }
857         }
858 out:
859         return iter->fa;
860 }
861
862 static struct fib_alias *fib_get_next(struct seq_file *seq)
863 {
864         struct fib_iter_state *iter = seq->private;
865         struct fib_node *fn;
866         struct fib_alias *fa;
867
868         /* Advance FA, if any. */
869         fn = iter->fn;
870         fa = iter->fa;
871         if (fa) {
872                 BUG_ON(!fn);
873                 list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) {
874                         iter->fa = fa;
875                         goto out;
876                 }
877         }
878
879         fa = iter->fa = NULL;
880
881         /* Advance FN. */
882         if (fn) {
883                 struct hlist_node *node = &fn->fn_hash;
884                 hlist_for_each_entry_continue(fn, node, fn_hash) {
885                         iter->fn = fn;
886
887                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
888                                 iter->fa = fa;
889                                 goto out;
890                         }
891                 }
892         }
893
894         fn = iter->fn = NULL;
895
896         /* Advance hash chain. */
897         if (!iter->zone)
898                 goto out;
899
900         for (;;) {
901                 struct hlist_node *node;
902                 int maxslot;
903
904                 maxslot = iter->zone->fz_divisor;
905
906                 while (++iter->bucket < maxslot) {
907                         iter->hash_head++;
908
909                         hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
910                                 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
911                                         iter->fn = fn;
912                                         iter->fa = fa;
913                                         goto out;
914                                 }
915                         }
916                 }
917
918                 iter->zone = iter->zone->fz_next;
919
920                 if (!iter->zone)
921                         goto out;
922
923                 iter->bucket = 0;
924                 iter->hash_head = iter->zone->fz_hash;
925
926                 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
927                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
928                                 iter->fn = fn;
929                                 iter->fa = fa;
930                                 goto out;
931                         }
932                 }
933         }
934 out:
935         iter->pos++;
936         return fa;
937 }
938
939 static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos)
940 {
941         struct fib_iter_state *iter = seq->private;
942         struct fib_alias *fa;
943
944         if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) {
945                 fa   = iter->fa;
946                 pos -= iter->pos;
947         } else
948                 fa = fib_get_first(seq);
949
950         if (fa)
951                 while (pos && (fa = fib_get_next(seq)))
952                         --pos;
953         return pos ? NULL : fa;
954 }
955
956 static void *fib_seq_start(struct seq_file *seq, loff_t *pos)
957         __acquires(fib_hash_lock)
958 {
959         void *v = NULL;
960
961         read_lock(&fib_hash_lock);
962         if (fib_get_table(seq_file_net(seq), RT_TABLE_MAIN))
963                 v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
964         return v;
965 }
966
967 static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
968 {
969         ++*pos;
970         return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
971 }
972
973 static void fib_seq_stop(struct seq_file *seq, void *v)
974         __releases(fib_hash_lock)
975 {
976         read_unlock(&fib_hash_lock);
977 }
978
979 static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
980 {
981         static const unsigned type2flags[RTN_MAX + 1] = {
982                 [7] = RTF_REJECT, [8] = RTF_REJECT,
983         };
984         unsigned flags = type2flags[type];
985
986         if (fi && fi->fib_nh->nh_gw)
987                 flags |= RTF_GATEWAY;
988         if (mask == htonl(0xFFFFFFFF))
989                 flags |= RTF_HOST;
990         flags |= RTF_UP;
991         return flags;
992 }
993
994 /*
995  *      This outputs /proc/net/route.
996  *
997  *      It always works in backward compatibility mode.
998  *      The format of the file is not supposed to be changed.
999  */
1000 static int fib_seq_show(struct seq_file *seq, void *v)
1001 {
1002         struct fib_iter_state *iter;
1003         int len;
1004         __be32 prefix, mask;
1005         unsigned flags;
1006         struct fib_node *f;
1007         struct fib_alias *fa;
1008         struct fib_info *fi;
1009
1010         if (v == SEQ_START_TOKEN) {
1011                 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
1012                            "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
1013                            "\tWindow\tIRTT");
1014                 goto out;
1015         }
1016
1017         iter    = seq->private;
1018         f       = iter->fn;
1019         fa      = iter->fa;
1020         fi      = fa->fa_info;
1021         prefix  = f->fn_key;
1022         mask    = FZ_MASK(iter->zone);
1023         flags   = fib_flag_trans(fa->fa_type, mask, fi);
1024         if (fi)
1025                 seq_printf(seq,
1026                          "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
1027                          fi->fib_dev ? fi->fib_dev->name : "*", prefix,
1028                          fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
1029                          mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
1030                          fi->fib_window,
1031                          fi->fib_rtt >> 3, &len);
1032         else
1033                 seq_printf(seq,
1034                          "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
1035                          prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0, &len);
1036
1037         seq_printf(seq, "%*s\n", 127 - len, "");
1038 out:
1039         return 0;
1040 }
1041
1042 static const struct seq_operations fib_seq_ops = {
1043         .start  = fib_seq_start,
1044         .next   = fib_seq_next,
1045         .stop   = fib_seq_stop,
1046         .show   = fib_seq_show,
1047 };
1048
1049 static int fib_seq_open(struct inode *inode, struct file *file)
1050 {
1051         return seq_open_net(inode, file, &fib_seq_ops,
1052                             sizeof(struct fib_iter_state));
1053 }
1054
1055 static const struct file_operations fib_seq_fops = {
1056         .owner          = THIS_MODULE,
1057         .open           = fib_seq_open,
1058         .read           = seq_read,
1059         .llseek         = seq_lseek,
1060         .release        = seq_release_net,
1061 };
1062
1063 int __net_init fib_proc_init(struct net *net)
1064 {
1065         if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_seq_fops))
1066                 return -ENOMEM;
1067         return 0;
1068 }
1069
1070 void __net_exit fib_proc_exit(struct net *net)
1071 {
1072         proc_net_remove(net, "route");
1073 }
1074 #endif /* CONFIG_PROC_FS */