bonding: IGMP handling cleanup
[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 #include <linux/slab.h>
36
37 #include <net/net_namespace.h>
38 #include <net/ip.h>
39 #include <net/protocol.h>
40 #include <net/route.h>
41 #include <net/tcp.h>
42 #include <net/sock.h>
43 #include <net/ip_fib.h>
44
45 #include "fib_lookup.h"
46
47 static struct kmem_cache *fn_hash_kmem __read_mostly;
48 static struct kmem_cache *fn_alias_kmem __read_mostly;
49
50 struct fib_node {
51         struct hlist_node       fn_hash;
52         struct list_head        fn_alias;
53         __be32                  fn_key;
54         struct fib_alias        fn_embedded_alias;
55 };
56
57 #define EMBEDDED_HASH_SIZE (L1_CACHE_BYTES / sizeof(struct hlist_head))
58
59 struct fn_zone {
60         struct fn_zone __rcu    *fz_next;       /* Next not empty zone  */
61         struct hlist_head __rcu *fz_hash;       /* Hash table pointer   */
62         seqlock_t               fz_lock;
63         u32                     fz_hashmask;    /* (fz_divisor - 1)     */
64
65         u8                      fz_order;       /* Zone order (0..32)   */
66         u8                      fz_revorder;    /* 32 - fz_order        */
67         __be32                  fz_mask;        /* inet_make_mask(order) */
68 #define FZ_MASK(fz)             ((fz)->fz_mask)
69
70         struct hlist_head       fz_embedded_hash[EMBEDDED_HASH_SIZE];
71
72         int                     fz_nent;        /* Number of entries    */
73         int                     fz_divisor;     /* Hash size (mask+1)   */
74 };
75
76 struct fn_hash {
77         struct fn_zone          *fn_zones[33];
78         struct fn_zone __rcu    *fn_zone_list;
79 };
80
81 static inline u32 fn_hash(__be32 key, struct fn_zone *fz)
82 {
83         u32 h = ntohl(key) >> fz->fz_revorder;
84         h ^= (h>>20);
85         h ^= (h>>10);
86         h ^= (h>>5);
87         h &= fz->fz_hashmask;
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 unsigned int fib_hash_genid;
97
98 #define FZ_MAX_DIVISOR ((PAGE_SIZE<<MAX_ORDER) / sizeof(struct hlist_head))
99
100 static struct hlist_head *fz_hash_alloc(int divisor)
101 {
102         unsigned long size = divisor * sizeof(struct hlist_head);
103
104         if (size <= PAGE_SIZE)
105                 return kzalloc(size, GFP_KERNEL);
106
107         return (struct hlist_head *)
108                 __get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(size));
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_rcu(&f->fn_hash);
126
127                         new_head = rcu_dereference_protected(fz->fz_hash, 1) +
128                                    fn_hash(f->fn_key, fz);
129                         hlist_add_head_rcu(&f->fn_hash, new_head);
130                 }
131         }
132 }
133
134 static void fz_hash_free(struct hlist_head *hash, int divisor)
135 {
136         unsigned long size = divisor * sizeof(struct hlist_head);
137
138         if (size <= PAGE_SIZE)
139                 kfree(hash);
140         else
141                 free_pages((unsigned long)hash, get_order(size));
142 }
143
144 static void fn_rehash_zone(struct fn_zone *fz)
145 {
146         struct hlist_head *ht, *old_ht;
147         int old_divisor, new_divisor;
148         u32 new_hashmask;
149
150         new_divisor = old_divisor = fz->fz_divisor;
151
152         switch (old_divisor) {
153         case EMBEDDED_HASH_SIZE:
154                 new_divisor *= EMBEDDED_HASH_SIZE;
155                 break;
156         case EMBEDDED_HASH_SIZE*EMBEDDED_HASH_SIZE:
157                 new_divisor *= (EMBEDDED_HASH_SIZE/2);
158                 break;
159         default:
160                 if ((old_divisor << 1) > FZ_MAX_DIVISOR) {
161                         printk(KERN_CRIT "route.c: bad divisor %d!\n", old_divisor);
162                         return;
163                 }
164                 new_divisor = (old_divisor << 1);
165                 break;
166         }
167
168         new_hashmask = (new_divisor - 1);
169
170 #if RT_CACHE_DEBUG >= 2
171         printk(KERN_DEBUG "fn_rehash_zone: hash for zone %d grows from %d\n",
172                fz->fz_order, old_divisor);
173 #endif
174
175         ht = fz_hash_alloc(new_divisor);
176
177         if (ht) {
178                 struct fn_zone nfz;
179
180                 memcpy(&nfz, fz, sizeof(nfz));
181
182                 write_seqlock_bh(&fz->fz_lock);
183                 old_ht = rcu_dereference_protected(fz->fz_hash, 1);
184                 RCU_INIT_POINTER(nfz.fz_hash, ht);
185                 nfz.fz_hashmask = new_hashmask;
186                 nfz.fz_divisor = new_divisor;
187                 fn_rebuild_zone(&nfz, old_ht, old_divisor);
188                 fib_hash_genid++;
189                 rcu_assign_pointer(fz->fz_hash, ht);
190                 fz->fz_hashmask = new_hashmask;
191                 fz->fz_divisor = new_divisor;
192                 write_sequnlock_bh(&fz->fz_lock);
193
194                 if (old_ht != fz->fz_embedded_hash) {
195                         synchronize_rcu();
196                         fz_hash_free(old_ht, old_divisor);
197                 }
198         }
199 }
200
201 static void fn_free_node_rcu(struct rcu_head *head)
202 {
203         struct fib_node *f = container_of(head, struct fib_node, fn_embedded_alias.rcu);
204
205         kmem_cache_free(fn_hash_kmem, f);
206 }
207
208 static inline void fn_free_node(struct fib_node *f)
209 {
210         call_rcu(&f->fn_embedded_alias.rcu, fn_free_node_rcu);
211 }
212
213 static void fn_free_alias_rcu(struct rcu_head *head)
214 {
215         struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
216
217         kmem_cache_free(fn_alias_kmem, fa);
218 }
219
220 static inline void fn_free_alias(struct fib_alias *fa, struct fib_node *f)
221 {
222         fib_release_info(fa->fa_info);
223         if (fa == &f->fn_embedded_alias)
224                 fa->fa_info = NULL;
225         else
226                 call_rcu(&fa->rcu, fn_free_alias_rcu);
227 }
228
229 static struct fn_zone *
230 fn_new_zone(struct fn_hash *table, int z)
231 {
232         int i;
233         struct fn_zone *fz = kzalloc(sizeof(struct fn_zone), GFP_KERNEL);
234         if (!fz)
235                 return NULL;
236
237         seqlock_init(&fz->fz_lock);
238         fz->fz_divisor = z ? EMBEDDED_HASH_SIZE : 1;
239         fz->fz_hashmask = fz->fz_divisor - 1;
240         RCU_INIT_POINTER(fz->fz_hash, fz->fz_embedded_hash);
241         fz->fz_order = z;
242         fz->fz_revorder = 32 - z;
243         fz->fz_mask = inet_make_mask(z);
244
245         /* Find the first not empty zone with more specific mask */
246         for (i = z + 1; i <= 32; i++)
247                 if (table->fn_zones[i])
248                         break;
249         if (i > 32) {
250                 /* No more specific masks, we are the first. */
251                 rcu_assign_pointer(fz->fz_next,
252                                    rtnl_dereference(table->fn_zone_list));
253                 rcu_assign_pointer(table->fn_zone_list, fz);
254         } else {
255                 rcu_assign_pointer(fz->fz_next,
256                                    rtnl_dereference(table->fn_zones[i]->fz_next));
257                 rcu_assign_pointer(table->fn_zones[i]->fz_next, fz);
258         }
259         table->fn_zones[z] = fz;
260         fib_hash_genid++;
261         return fz;
262 }
263
264 int fib_table_lookup(struct fib_table *tb,
265                      const struct flowi *flp, struct fib_result *res,
266                      int fib_flags)
267 {
268         int err;
269         struct fn_zone *fz;
270         struct fn_hash *t = (struct fn_hash *)tb->tb_data;
271
272         rcu_read_lock();
273         for (fz = rcu_dereference(t->fn_zone_list);
274              fz != NULL;
275              fz = rcu_dereference(fz->fz_next)) {
276                 struct hlist_head *head;
277                 struct hlist_node *node;
278                 struct fib_node *f;
279                 __be32 k;
280                 unsigned int seq;
281
282                 do {
283                         seq = read_seqbegin(&fz->fz_lock);
284                         k = fz_key(flp->fl4_dst, fz);
285
286                         head = rcu_dereference(fz->fz_hash) + fn_hash(k, fz);
287                         hlist_for_each_entry_rcu(f, node, head, fn_hash) {
288                                 if (f->fn_key != k)
289                                         continue;
290
291                                 err = fib_semantic_match(&f->fn_alias,
292                                                  flp, res,
293                                                  fz->fz_order, fib_flags);
294                                 if (err <= 0)
295                                         goto out;
296                         }
297                 } while (read_seqretry(&fz->fz_lock, seq));
298         }
299         err = 1;
300 out:
301         rcu_read_unlock();
302         return err;
303 }
304
305 void fib_table_select_default(struct fib_table *tb,
306                               const struct flowi *flp, struct fib_result *res)
307 {
308         int order, last_idx;
309         struct hlist_node *node;
310         struct fib_node *f;
311         struct fib_info *fi = NULL;
312         struct fib_info *last_resort;
313         struct fn_hash *t = (struct fn_hash *)tb->tb_data;
314         struct fn_zone *fz = t->fn_zones[0];
315         struct hlist_head *head;
316
317         if (fz == NULL)
318                 return;
319
320         last_idx = -1;
321         last_resort = NULL;
322         order = -1;
323
324         rcu_read_lock();
325         head = rcu_dereference(fz->fz_hash);
326         hlist_for_each_entry_rcu(f, node, head, fn_hash) {
327                 struct fib_alias *fa;
328
329                 list_for_each_entry_rcu(fa, &f->fn_alias, fa_list) {
330                         struct fib_info *next_fi = fa->fa_info;
331
332                         if (fa->fa_scope != res->scope ||
333                             fa->fa_type != RTN_UNICAST)
334                                 continue;
335
336                         if (next_fi->fib_priority > res->fi->fib_priority)
337                                 break;
338                         if (!next_fi->fib_nh[0].nh_gw ||
339                             next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
340                                 continue;
341
342                         fib_alias_accessed(fa);
343
344                         if (fi == NULL) {
345                                 if (next_fi != res->fi)
346                                         break;
347                         } else if (!fib_detect_death(fi, order, &last_resort,
348                                                 &last_idx, tb->tb_default)) {
349                                 fib_result_assign(res, fi);
350                                 tb->tb_default = order;
351                                 goto out;
352                         }
353                         fi = next_fi;
354                         order++;
355                 }
356         }
357
358         if (order <= 0 || fi == NULL) {
359                 tb->tb_default = -1;
360                 goto out;
361         }
362
363         if (!fib_detect_death(fi, order, &last_resort, &last_idx,
364                                 tb->tb_default)) {
365                 fib_result_assign(res, fi);
366                 tb->tb_default = order;
367                 goto out;
368         }
369
370         if (last_idx >= 0)
371                 fib_result_assign(res, last_resort);
372         tb->tb_default = last_idx;
373 out:
374         rcu_read_unlock();
375 }
376
377 /* Insert node F to FZ. */
378 static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
379 {
380         struct hlist_head *head = rtnl_dereference(fz->fz_hash) + fn_hash(f->fn_key, fz);
381
382         hlist_add_head_rcu(&f->fn_hash, head);
383 }
384
385 /* Return the node in FZ matching KEY. */
386 static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key)
387 {
388         struct hlist_head *head = rtnl_dereference(fz->fz_hash) + fn_hash(key, fz);
389         struct hlist_node *node;
390         struct fib_node *f;
391
392         hlist_for_each_entry_rcu(f, node, head, fn_hash) {
393                 if (f->fn_key == key)
394                         return f;
395         }
396
397         return NULL;
398 }
399
400
401 static struct fib_alias *fib_fast_alloc(struct fib_node *f)
402 {
403         struct fib_alias *fa = &f->fn_embedded_alias;
404
405         if (fa->fa_info != NULL)
406                 fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
407         return fa;
408 }
409
410 /* Caller must hold RTNL. */
411 int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
412 {
413         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
414         struct fib_node *new_f = NULL;
415         struct fib_node *f;
416         struct fib_alias *fa, *new_fa;
417         struct fn_zone *fz;
418         struct fib_info *fi;
419         u8 tos = cfg->fc_tos;
420         __be32 key;
421         int err;
422
423         if (cfg->fc_dst_len > 32)
424                 return -EINVAL;
425
426         fz = table->fn_zones[cfg->fc_dst_len];
427         if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len)))
428                 return -ENOBUFS;
429
430         key = 0;
431         if (cfg->fc_dst) {
432                 if (cfg->fc_dst & ~FZ_MASK(fz))
433                         return -EINVAL;
434                 key = fz_key(cfg->fc_dst, fz);
435         }
436
437         fi = fib_create_info(cfg);
438         if (IS_ERR(fi))
439                 return PTR_ERR(fi);
440
441         if (fz->fz_nent > (fz->fz_divisor<<1) &&
442             fz->fz_divisor < FZ_MAX_DIVISOR &&
443             (cfg->fc_dst_len == 32 ||
444              (1 << cfg->fc_dst_len) > fz->fz_divisor))
445                 fn_rehash_zone(fz);
446
447         f = fib_find_node(fz, key);
448
449         if (!f)
450                 fa = NULL;
451         else
452                 fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority);
453
454         /* Now fa, if non-NULL, points to the first fib alias
455          * with the same keys [prefix,tos,priority], if such key already
456          * exists or to the node before which we will insert new one.
457          *
458          * If fa is NULL, we will need to allocate a new one and
459          * insert to the head of f.
460          *
461          * If f is NULL, no fib node matched the destination key
462          * and we need to allocate a new one of those as well.
463          */
464
465         if (fa && fa->fa_tos == tos &&
466             fa->fa_info->fib_priority == fi->fib_priority) {
467                 struct fib_alias *fa_first, *fa_match;
468
469                 err = -EEXIST;
470                 if (cfg->fc_nlflags & NLM_F_EXCL)
471                         goto out;
472
473                 /* We have 2 goals:
474                  * 1. Find exact match for type, scope, fib_info to avoid
475                  * duplicate routes
476                  * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
477                  */
478                 fa_match = NULL;
479                 fa_first = fa;
480                 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
481                 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
482                         if (fa->fa_tos != tos)
483                                 break;
484                         if (fa->fa_info->fib_priority != fi->fib_priority)
485                                 break;
486                         if (fa->fa_type == cfg->fc_type &&
487                             fa->fa_scope == cfg->fc_scope &&
488                             fa->fa_info == fi) {
489                                 fa_match = fa;
490                                 break;
491                         }
492                 }
493
494                 if (cfg->fc_nlflags & NLM_F_REPLACE) {
495                         u8 state;
496
497                         fa = fa_first;
498                         if (fa_match) {
499                                 if (fa == fa_match)
500                                         err = 0;
501                                 goto out;
502                         }
503                         err = -ENOBUFS;
504                         new_fa = fib_fast_alloc(f);
505                         if (new_fa == NULL)
506                                 goto out;
507
508                         new_fa->fa_tos = fa->fa_tos;
509                         new_fa->fa_info = fi;
510                         new_fa->fa_type = cfg->fc_type;
511                         new_fa->fa_scope = cfg->fc_scope;
512                         state = fa->fa_state;
513                         new_fa->fa_state = state & ~FA_S_ACCESSED;
514                         fib_hash_genid++;
515                         list_replace_rcu(&fa->fa_list, &new_fa->fa_list);
516
517                         fn_free_alias(fa, f);
518                         if (state & FA_S_ACCESSED)
519                                 rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
520                         rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len,
521                                   tb->tb_id, &cfg->fc_nlinfo, NLM_F_REPLACE);
522                         return 0;
523                 }
524
525                 /* Error if we find a perfect match which
526                  * uses the same scope, type, and nexthop
527                  * information.
528                  */
529                 if (fa_match)
530                         goto out;
531
532                 if (!(cfg->fc_nlflags & NLM_F_APPEND))
533                         fa = fa_first;
534         }
535
536         err = -ENOENT;
537         if (!(cfg->fc_nlflags & NLM_F_CREATE))
538                 goto out;
539
540         err = -ENOBUFS;
541
542         if (!f) {
543                 new_f = kmem_cache_zalloc(fn_hash_kmem, GFP_KERNEL);
544                 if (new_f == NULL)
545                         goto out;
546
547                 INIT_HLIST_NODE(&new_f->fn_hash);
548                 INIT_LIST_HEAD(&new_f->fn_alias);
549                 new_f->fn_key = key;
550                 f = new_f;
551         }
552
553         new_fa = fib_fast_alloc(f);
554         if (new_fa == NULL)
555                 goto out;
556
557         new_fa->fa_info = fi;
558         new_fa->fa_tos = tos;
559         new_fa->fa_type = cfg->fc_type;
560         new_fa->fa_scope = cfg->fc_scope;
561         new_fa->fa_state = 0;
562
563         /*
564          * Insert new entry to the list.
565          */
566
567         if (new_f)
568                 fib_insert_node(fz, new_f);
569         list_add_tail_rcu(&new_fa->fa_list,
570                  (fa ? &fa->fa_list : &f->fn_alias));
571         fib_hash_genid++;
572
573         if (new_f)
574                 fz->fz_nent++;
575         rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
576
577         rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id,
578                   &cfg->fc_nlinfo, 0);
579         return 0;
580
581 out:
582         if (new_f)
583                 kmem_cache_free(fn_hash_kmem, new_f);
584         fib_release_info(fi);
585         return err;
586 }
587
588 int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
589 {
590         struct fn_hash *table = (struct fn_hash *)tb->tb_data;
591         struct fib_node *f;
592         struct fib_alias *fa, *fa_to_delete;
593         struct fn_zone *fz;
594         __be32 key;
595
596         if (cfg->fc_dst_len > 32)
597                 return -EINVAL;
598
599         if ((fz  = table->fn_zones[cfg->fc_dst_len]) == NULL)
600                 return -ESRCH;
601
602         key = 0;
603         if (cfg->fc_dst) {
604                 if (cfg->fc_dst & ~FZ_MASK(fz))
605                         return -EINVAL;
606                 key = fz_key(cfg->fc_dst, fz);
607         }
608
609         f = fib_find_node(fz, key);
610
611         if (!f)
612                 fa = NULL;
613         else
614                 fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0);
615         if (!fa)
616                 return -ESRCH;
617
618         fa_to_delete = NULL;
619         fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
620         list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
621                 struct fib_info *fi = fa->fa_info;
622
623                 if (fa->fa_tos != cfg->fc_tos)
624                         break;
625
626                 if ((!cfg->fc_type ||
627                      fa->fa_type == cfg->fc_type) &&
628                     (cfg->fc_scope == RT_SCOPE_NOWHERE ||
629                      fa->fa_scope == cfg->fc_scope) &&
630                     (!cfg->fc_protocol ||
631                      fi->fib_protocol == cfg->fc_protocol) &&
632                     fib_nh_match(cfg, fi) == 0) {
633                         fa_to_delete = fa;
634                         break;
635                 }
636         }
637
638         if (fa_to_delete) {
639                 int kill_fn;
640
641                 fa = fa_to_delete;
642                 rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len,
643                           tb->tb_id, &cfg->fc_nlinfo, 0);
644
645                 kill_fn = 0;
646                 list_del_rcu(&fa->fa_list);
647                 if (list_empty(&f->fn_alias)) {
648                         hlist_del_rcu(&f->fn_hash);
649                         kill_fn = 1;
650                 }
651                 fib_hash_genid++;
652
653                 if (fa->fa_state & FA_S_ACCESSED)
654                         rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
655                 fn_free_alias(fa, f);
656                 if (kill_fn) {
657                         fn_free_node(f);
658                         fz->fz_nent--;
659                 }
660
661                 return 0;
662         }
663         return -ESRCH;
664 }
665
666 static int fn_flush_list(struct fn_zone *fz, int idx)
667 {
668         struct hlist_head *head = rtnl_dereference(fz->fz_hash) + idx;
669         struct hlist_node *node, *n;
670         struct fib_node *f;
671         int found = 0;
672
673         hlist_for_each_entry_safe(f, node, n, head, fn_hash) {
674                 struct fib_alias *fa, *fa_node;
675                 int kill_f;
676
677                 kill_f = 0;
678                 list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) {
679                         struct fib_info *fi = fa->fa_info;
680
681                         if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
682                                 list_del_rcu(&fa->fa_list);
683                                 if (list_empty(&f->fn_alias)) {
684                                         hlist_del_rcu(&f->fn_hash);
685                                         kill_f = 1;
686                                 }
687                                 fib_hash_genid++;
688
689                                 fn_free_alias(fa, f);
690                                 found++;
691                         }
692                 }
693                 if (kill_f) {
694                         fn_free_node(f);
695                         fz->fz_nent--;
696                 }
697         }
698         return found;
699 }
700
701 /* caller must hold RTNL. */
702 int fib_table_flush(struct fib_table *tb)
703 {
704         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
705         struct fn_zone *fz;
706         int found = 0;
707
708         for (fz = rtnl_dereference(table->fn_zone_list);
709              fz != NULL;
710              fz = rtnl_dereference(fz->fz_next)) {
711                 int i;
712
713                 for (i = fz->fz_divisor - 1; i >= 0; i--)
714                         found += fn_flush_list(fz, i);
715         }
716         return found;
717 }
718
719 void fib_free_table(struct fib_table *tb)
720 {
721         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
722         struct fn_zone *fz, *next;
723
724         next = table->fn_zone_list;
725         while (next != NULL) {
726                 fz = next;
727                 next = fz->fz_next;
728
729                 if (fz->fz_hash != fz->fz_embedded_hash)
730                         fz_hash_free(fz->fz_hash, fz->fz_divisor);
731
732                 kfree(fz);
733         }
734
735         kfree(tb);
736 }
737
738 static inline int
739 fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
740                      struct fib_table *tb,
741                      struct fn_zone *fz,
742                      struct hlist_head *head)
743 {
744         struct hlist_node *node;
745         struct fib_node *f;
746         int i, s_i;
747
748         s_i = cb->args[4];
749         i = 0;
750         hlist_for_each_entry_rcu(f, node, head, fn_hash) {
751                 struct fib_alias *fa;
752
753                 list_for_each_entry_rcu(fa, &f->fn_alias, fa_list) {
754                         if (i < s_i)
755                                 goto next;
756
757                         if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
758                                           cb->nlh->nlmsg_seq,
759                                           RTM_NEWROUTE,
760                                           tb->tb_id,
761                                           fa->fa_type,
762                                           fa->fa_scope,
763                                           f->fn_key,
764                                           fz->fz_order,
765                                           fa->fa_tos,
766                                           fa->fa_info,
767                                           NLM_F_MULTI) < 0) {
768                                 cb->args[4] = i;
769                                 return -1;
770                         }
771 next:
772                         i++;
773                 }
774         }
775         cb->args[4] = i;
776         return skb->len;
777 }
778
779 static inline int
780 fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
781                    struct fib_table *tb,
782                    struct fn_zone *fz)
783 {
784         int h, s_h;
785         struct hlist_head *head = rcu_dereference(fz->fz_hash);
786
787         if (head == NULL)
788                 return skb->len;
789         s_h = cb->args[3];
790         for (h = s_h; h < fz->fz_divisor; h++) {
791                 if (hlist_empty(head + h))
792                         continue;
793                 if (fn_hash_dump_bucket(skb, cb, tb, fz, head + h) < 0) {
794                         cb->args[3] = h;
795                         return -1;
796                 }
797                 memset(&cb->args[4], 0,
798                        sizeof(cb->args) - 4*sizeof(cb->args[0]));
799         }
800         cb->args[3] = h;
801         return skb->len;
802 }
803
804 int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
805                    struct netlink_callback *cb)
806 {
807         int m = 0, s_m;
808         struct fn_zone *fz;
809         struct fn_hash *table = (struct fn_hash *)tb->tb_data;
810
811         s_m = cb->args[2];
812         rcu_read_lock();
813         for (fz = rcu_dereference(table->fn_zone_list);
814              fz != NULL;
815              fz = rcu_dereference(fz->fz_next), m++) {
816                 if (m < s_m)
817                         continue;
818                 if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
819                         cb->args[2] = m;
820                         rcu_read_unlock();
821                         return -1;
822                 }
823                 memset(&cb->args[3], 0,
824                        sizeof(cb->args) - 3*sizeof(cb->args[0]));
825         }
826         rcu_read_unlock();
827         cb->args[2] = m;
828         return skb->len;
829 }
830
831 void __init fib_hash_init(void)
832 {
833         fn_hash_kmem = kmem_cache_create("ip_fib_hash", sizeof(struct fib_node),
834                                          0, SLAB_PANIC, NULL);
835
836         fn_alias_kmem = kmem_cache_create("ip_fib_alias", sizeof(struct fib_alias),
837                                           0, SLAB_PANIC, NULL);
838
839 }
840
841 struct fib_table *fib_hash_table(u32 id)
842 {
843         struct fib_table *tb;
844
845         tb = kmalloc(sizeof(struct fib_table) + sizeof(struct fn_hash),
846                      GFP_KERNEL);
847         if (tb == NULL)
848                 return NULL;
849
850         tb->tb_id = id;
851         tb->tb_default = -1;
852
853         memset(tb->tb_data, 0, sizeof(struct fn_hash));
854         return tb;
855 }
856
857 /* ------------------------------------------------------------------------ */
858 #ifdef CONFIG_PROC_FS
859
860 struct fib_iter_state {
861         struct seq_net_private p;
862         struct fn_zone  *zone;
863         int             bucket;
864         struct hlist_head *hash_head;
865         struct fib_node *fn;
866         struct fib_alias *fa;
867         loff_t pos;
868         unsigned int genid;
869         int valid;
870 };
871
872 static struct fib_alias *fib_get_first(struct seq_file *seq)
873 {
874         struct fib_iter_state *iter = seq->private;
875         struct fib_table *main_table;
876         struct fn_hash *table;
877
878         main_table = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
879         table = (struct fn_hash *)main_table->tb_data;
880
881         iter->bucket    = 0;
882         iter->hash_head = NULL;
883         iter->fn        = NULL;
884         iter->fa        = NULL;
885         iter->pos       = 0;
886         iter->genid     = fib_hash_genid;
887         iter->valid     = 1;
888
889         for (iter->zone = rcu_dereference(table->fn_zone_list);
890              iter->zone != NULL;
891              iter->zone = rcu_dereference(iter->zone->fz_next)) {
892                 int maxslot;
893
894                 if (!iter->zone->fz_nent)
895                         continue;
896
897                 iter->hash_head = rcu_dereference(iter->zone->fz_hash);
898                 maxslot = iter->zone->fz_divisor;
899
900                 for (iter->bucket = 0; iter->bucket < maxslot;
901                      ++iter->bucket, ++iter->hash_head) {
902                         struct hlist_node *node;
903                         struct fib_node *fn;
904
905                         hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
906                                 struct fib_alias *fa;
907
908                                 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
909                                         iter->fn = fn;
910                                         iter->fa = fa;
911                                         goto out;
912                                 }
913                         }
914                 }
915         }
916 out:
917         return iter->fa;
918 }
919
920 static struct fib_alias *fib_get_next(struct seq_file *seq)
921 {
922         struct fib_iter_state *iter = seq->private;
923         struct fib_node *fn;
924         struct fib_alias *fa;
925
926         /* Advance FA, if any. */
927         fn = iter->fn;
928         fa = iter->fa;
929         if (fa) {
930                 BUG_ON(!fn);
931                 list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) {
932                         iter->fa = fa;
933                         goto out;
934                 }
935         }
936
937         fa = iter->fa = NULL;
938
939         /* Advance FN. */
940         if (fn) {
941                 struct hlist_node *node = &fn->fn_hash;
942                 hlist_for_each_entry_continue(fn, node, fn_hash) {
943                         iter->fn = fn;
944
945                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
946                                 iter->fa = fa;
947                                 goto out;
948                         }
949                 }
950         }
951
952         fn = iter->fn = NULL;
953
954         /* Advance hash chain. */
955         if (!iter->zone)
956                 goto out;
957
958         for (;;) {
959                 struct hlist_node *node;
960                 int maxslot;
961
962                 maxslot = iter->zone->fz_divisor;
963
964                 while (++iter->bucket < maxslot) {
965                         iter->hash_head++;
966
967                         hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
968                                 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
969                                         iter->fn = fn;
970                                         iter->fa = fa;
971                                         goto out;
972                                 }
973                         }
974                 }
975
976                 iter->zone = rcu_dereference(iter->zone->fz_next);
977
978                 if (!iter->zone)
979                         goto out;
980
981                 iter->bucket = 0;
982                 iter->hash_head = rcu_dereference(iter->zone->fz_hash);
983
984                 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
985                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
986                                 iter->fn = fn;
987                                 iter->fa = fa;
988                                 goto out;
989                         }
990                 }
991         }
992 out:
993         iter->pos++;
994         return fa;
995 }
996
997 static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos)
998 {
999         struct fib_iter_state *iter = seq->private;
1000         struct fib_alias *fa;
1001
1002         if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) {
1003                 fa   = iter->fa;
1004                 pos -= iter->pos;
1005         } else
1006                 fa = fib_get_first(seq);
1007
1008         if (fa)
1009                 while (pos && (fa = fib_get_next(seq)))
1010                         --pos;
1011         return pos ? NULL : fa;
1012 }
1013
1014 static void *fib_seq_start(struct seq_file *seq, loff_t *pos)
1015         __acquires(RCU)
1016 {
1017         void *v = NULL;
1018
1019         rcu_read_lock();
1020         if (fib_get_table(seq_file_net(seq), RT_TABLE_MAIN))
1021                 v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
1022         return v;
1023 }
1024
1025 static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1026 {
1027         ++*pos;
1028         return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
1029 }
1030
1031 static void fib_seq_stop(struct seq_file *seq, void *v)
1032         __releases(RCU)
1033 {
1034         rcu_read_unlock();
1035 }
1036
1037 static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
1038 {
1039         static const unsigned type2flags[RTN_MAX + 1] = {
1040                 [7] = RTF_REJECT,
1041                 [8] = RTF_REJECT,
1042         };
1043         unsigned flags = type2flags[type];
1044
1045         if (fi && fi->fib_nh->nh_gw)
1046                 flags |= RTF_GATEWAY;
1047         if (mask == htonl(0xFFFFFFFF))
1048                 flags |= RTF_HOST;
1049         flags |= RTF_UP;
1050         return flags;
1051 }
1052
1053 /*
1054  *      This outputs /proc/net/route.
1055  *
1056  *      It always works in backward compatibility mode.
1057  *      The format of the file is not supposed to be changed.
1058  */
1059 static int fib_seq_show(struct seq_file *seq, void *v)
1060 {
1061         struct fib_iter_state *iter;
1062         int len;
1063         __be32 prefix, mask;
1064         unsigned flags;
1065         struct fib_node *f;
1066         struct fib_alias *fa;
1067         struct fib_info *fi;
1068
1069         if (v == SEQ_START_TOKEN) {
1070                 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
1071                            "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
1072                            "\tWindow\tIRTT");
1073                 goto out;
1074         }
1075
1076         iter    = seq->private;
1077         f       = iter->fn;
1078         fa      = iter->fa;
1079         fi      = fa->fa_info;
1080         prefix  = f->fn_key;
1081         mask    = FZ_MASK(iter->zone);
1082         flags   = fib_flag_trans(fa->fa_type, mask, fi);
1083         if (fi)
1084                 seq_printf(seq,
1085                          "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
1086                          fi->fib_dev ? fi->fib_dev->name : "*", prefix,
1087                          fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
1088                          mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
1089                          fi->fib_window,
1090                          fi->fib_rtt >> 3, &len);
1091         else
1092                 seq_printf(seq,
1093                          "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
1094                          prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0, &len);
1095
1096         seq_printf(seq, "%*s\n", 127 - len, "");
1097 out:
1098         return 0;
1099 }
1100
1101 static const struct seq_operations fib_seq_ops = {
1102         .start  = fib_seq_start,
1103         .next   = fib_seq_next,
1104         .stop   = fib_seq_stop,
1105         .show   = fib_seq_show,
1106 };
1107
1108 static int fib_seq_open(struct inode *inode, struct file *file)
1109 {
1110         return seq_open_net(inode, file, &fib_seq_ops,
1111                             sizeof(struct fib_iter_state));
1112 }
1113
1114 static const struct file_operations fib_seq_fops = {
1115         .owner          = THIS_MODULE,
1116         .open           = fib_seq_open,
1117         .read           = seq_read,
1118         .llseek         = seq_lseek,
1119         .release        = seq_release_net,
1120 };
1121
1122 int __net_init fib_proc_init(struct net *net)
1123 {
1124         if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_seq_fops))
1125                 return -ENOMEM;
1126         return 0;
1127 }
1128
1129 void __net_exit fib_proc_exit(struct net *net)
1130 {
1131         proc_net_remove(net, "route");
1132 }
1133 #endif /* CONFIG_PROC_FS */