netfilter: x_tables: use NFPROTO_* in extensions
[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                                                  f->fn_key, fz->fz_mask,
267                                                  fz->fz_order);
268                         if (err <= 0)
269                                 goto out;
270                 }
271         }
272         err = 1;
273 out:
274         read_unlock(&fib_hash_lock);
275         return err;
276 }
277
278 static void
279 fn_hash_select_default(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
280 {
281         int order, last_idx;
282         struct hlist_node *node;
283         struct fib_node *f;
284         struct fib_info *fi = NULL;
285         struct fib_info *last_resort;
286         struct fn_hash *t = (struct fn_hash*)tb->tb_data;
287         struct fn_zone *fz = t->fn_zones[0];
288
289         if (fz == NULL)
290                 return;
291
292         last_idx = -1;
293         last_resort = NULL;
294         order = -1;
295
296         read_lock(&fib_hash_lock);
297         hlist_for_each_entry(f, node, &fz->fz_hash[0], fn_hash) {
298                 struct fib_alias *fa;
299
300                 list_for_each_entry(fa, &f->fn_alias, fa_list) {
301                         struct fib_info *next_fi = fa->fa_info;
302
303                         if (fa->fa_scope != res->scope ||
304                             fa->fa_type != RTN_UNICAST)
305                                 continue;
306
307                         if (next_fi->fib_priority > res->fi->fib_priority)
308                                 break;
309                         if (!next_fi->fib_nh[0].nh_gw ||
310                             next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
311                                 continue;
312                         fa->fa_state |= FA_S_ACCESSED;
313
314                         if (fi == NULL) {
315                                 if (next_fi != res->fi)
316                                         break;
317                         } else if (!fib_detect_death(fi, order, &last_resort,
318                                                 &last_idx, tb->tb_default)) {
319                                 fib_result_assign(res, fi);
320                                 tb->tb_default = order;
321                                 goto out;
322                         }
323                         fi = next_fi;
324                         order++;
325                 }
326         }
327
328         if (order <= 0 || fi == NULL) {
329                 tb->tb_default = -1;
330                 goto out;
331         }
332
333         if (!fib_detect_death(fi, order, &last_resort, &last_idx,
334                                 tb->tb_default)) {
335                 fib_result_assign(res, fi);
336                 tb->tb_default = order;
337                 goto out;
338         }
339
340         if (last_idx >= 0)
341                 fib_result_assign(res, last_resort);
342         tb->tb_default = last_idx;
343 out:
344         read_unlock(&fib_hash_lock);
345 }
346
347 /* Insert node F to FZ. */
348 static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
349 {
350         struct hlist_head *head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
351
352         hlist_add_head(&f->fn_hash, head);
353 }
354
355 /* Return the node in FZ matching KEY. */
356 static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key)
357 {
358         struct hlist_head *head = &fz->fz_hash[fn_hash(key, fz)];
359         struct hlist_node *node;
360         struct fib_node *f;
361
362         hlist_for_each_entry(f, node, head, fn_hash) {
363                 if (f->fn_key == key)
364                         return f;
365         }
366
367         return NULL;
368 }
369
370 static int fn_hash_insert(struct fib_table *tb, struct fib_config *cfg)
371 {
372         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
373         struct fib_node *new_f = NULL;
374         struct fib_node *f;
375         struct fib_alias *fa, *new_fa;
376         struct fn_zone *fz;
377         struct fib_info *fi;
378         u8 tos = cfg->fc_tos;
379         __be32 key;
380         int err;
381
382         if (cfg->fc_dst_len > 32)
383                 return -EINVAL;
384
385         fz = table->fn_zones[cfg->fc_dst_len];
386         if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len)))
387                 return -ENOBUFS;
388
389         key = 0;
390         if (cfg->fc_dst) {
391                 if (cfg->fc_dst & ~FZ_MASK(fz))
392                         return -EINVAL;
393                 key = fz_key(cfg->fc_dst, fz);
394         }
395
396         fi = fib_create_info(cfg);
397         if (IS_ERR(fi))
398                 return PTR_ERR(fi);
399
400         if (fz->fz_nent > (fz->fz_divisor<<1) &&
401             fz->fz_divisor < FZ_MAX_DIVISOR &&
402             (cfg->fc_dst_len == 32 ||
403              (1 << cfg->fc_dst_len) > fz->fz_divisor))
404                 fn_rehash_zone(fz);
405
406         f = fib_find_node(fz, key);
407
408         if (!f)
409                 fa = NULL;
410         else
411                 fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority);
412
413         /* Now fa, if non-NULL, points to the first fib alias
414          * with the same keys [prefix,tos,priority], if such key already
415          * exists or to the node before which we will insert new one.
416          *
417          * If fa is NULL, we will need to allocate a new one and
418          * insert to the head of f.
419          *
420          * If f is NULL, no fib node matched the destination key
421          * and we need to allocate a new one of those as well.
422          */
423
424         if (fa && fa->fa_tos == tos &&
425             fa->fa_info->fib_priority == fi->fib_priority) {
426                 struct fib_alias *fa_first, *fa_match;
427
428                 err = -EEXIST;
429                 if (cfg->fc_nlflags & NLM_F_EXCL)
430                         goto out;
431
432                 /* We have 2 goals:
433                  * 1. Find exact match for type, scope, fib_info to avoid
434                  * duplicate routes
435                  * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
436                  */
437                 fa_match = NULL;
438                 fa_first = fa;
439                 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
440                 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
441                         if (fa->fa_tos != tos)
442                                 break;
443                         if (fa->fa_info->fib_priority != fi->fib_priority)
444                                 break;
445                         if (fa->fa_type == cfg->fc_type &&
446                             fa->fa_scope == cfg->fc_scope &&
447                             fa->fa_info == fi) {
448                                 fa_match = fa;
449                                 break;
450                         }
451                 }
452
453                 if (cfg->fc_nlflags & NLM_F_REPLACE) {
454                         struct fib_info *fi_drop;
455                         u8 state;
456
457                         fa = fa_first;
458                         if (fa_match) {
459                                 if (fa == fa_match)
460                                         err = 0;
461                                 goto out;
462                         }
463                         write_lock_bh(&fib_hash_lock);
464                         fi_drop = fa->fa_info;
465                         fa->fa_info = fi;
466                         fa->fa_type = cfg->fc_type;
467                         fa->fa_scope = cfg->fc_scope;
468                         state = fa->fa_state;
469                         fa->fa_state &= ~FA_S_ACCESSED;
470                         fib_hash_genid++;
471                         write_unlock_bh(&fib_hash_lock);
472
473                         fib_release_info(fi_drop);
474                         if (state & FA_S_ACCESSED)
475                                 rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
476                         rtmsg_fib(RTM_NEWROUTE, key, fa, cfg->fc_dst_len, tb->tb_id,
477                                   &cfg->fc_nlinfo, NLM_F_REPLACE);
478                         return 0;
479                 }
480
481                 /* Error if we find a perfect match which
482                  * uses the same scope, type, and nexthop
483                  * information.
484                  */
485                 if (fa_match)
486                         goto out;
487
488                 if (!(cfg->fc_nlflags & NLM_F_APPEND))
489                         fa = fa_first;
490         }
491
492         err = -ENOENT;
493         if (!(cfg->fc_nlflags & NLM_F_CREATE))
494                 goto out;
495
496         err = -ENOBUFS;
497
498         if (!f) {
499                 new_f = kmem_cache_zalloc(fn_hash_kmem, GFP_KERNEL);
500                 if (new_f == NULL)
501                         goto out;
502
503                 INIT_HLIST_NODE(&new_f->fn_hash);
504                 INIT_LIST_HEAD(&new_f->fn_alias);
505                 new_f->fn_key = key;
506                 f = new_f;
507         }
508
509         new_fa = &f->fn_embedded_alias;
510         if (new_fa->fa_info != NULL) {
511                 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
512                 if (new_fa == NULL)
513                         goto out;
514         }
515         new_fa->fa_info = fi;
516         new_fa->fa_tos = tos;
517         new_fa->fa_type = cfg->fc_type;
518         new_fa->fa_scope = cfg->fc_scope;
519         new_fa->fa_state = 0;
520
521         /*
522          * Insert new entry to the list.
523          */
524
525         write_lock_bh(&fib_hash_lock);
526         if (new_f)
527                 fib_insert_node(fz, new_f);
528         list_add_tail(&new_fa->fa_list,
529                  (fa ? &fa->fa_list : &f->fn_alias));
530         fib_hash_genid++;
531         write_unlock_bh(&fib_hash_lock);
532
533         if (new_f)
534                 fz->fz_nent++;
535         rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
536
537         rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id,
538                   &cfg->fc_nlinfo, 0);
539         return 0;
540
541 out:
542         if (new_f)
543                 kmem_cache_free(fn_hash_kmem, new_f);
544         fib_release_info(fi);
545         return err;
546 }
547
548
549 static int fn_hash_delete(struct fib_table *tb, struct fib_config *cfg)
550 {
551         struct fn_hash *table = (struct fn_hash*)tb->tb_data;
552         struct fib_node *f;
553         struct fib_alias *fa, *fa_to_delete;
554         struct fn_zone *fz;
555         __be32 key;
556
557         if (cfg->fc_dst_len > 32)
558                 return -EINVAL;
559
560         if ((fz  = table->fn_zones[cfg->fc_dst_len]) == NULL)
561                 return -ESRCH;
562
563         key = 0;
564         if (cfg->fc_dst) {
565                 if (cfg->fc_dst & ~FZ_MASK(fz))
566                         return -EINVAL;
567                 key = fz_key(cfg->fc_dst, fz);
568         }
569
570         f = fib_find_node(fz, key);
571
572         if (!f)
573                 fa = NULL;
574         else
575                 fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0);
576         if (!fa)
577                 return -ESRCH;
578
579         fa_to_delete = NULL;
580         fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
581         list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
582                 struct fib_info *fi = fa->fa_info;
583
584                 if (fa->fa_tos != cfg->fc_tos)
585                         break;
586
587                 if ((!cfg->fc_type ||
588                      fa->fa_type == cfg->fc_type) &&
589                     (cfg->fc_scope == RT_SCOPE_NOWHERE ||
590                      fa->fa_scope == cfg->fc_scope) &&
591                     (!cfg->fc_protocol ||
592                      fi->fib_protocol == cfg->fc_protocol) &&
593                     fib_nh_match(cfg, fi) == 0) {
594                         fa_to_delete = fa;
595                         break;
596                 }
597         }
598
599         if (fa_to_delete) {
600                 int kill_fn;
601
602                 fa = fa_to_delete;
603                 rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len,
604                           tb->tb_id, &cfg->fc_nlinfo, 0);
605
606                 kill_fn = 0;
607                 write_lock_bh(&fib_hash_lock);
608                 list_del(&fa->fa_list);
609                 if (list_empty(&f->fn_alias)) {
610                         hlist_del(&f->fn_hash);
611                         kill_fn = 1;
612                 }
613                 fib_hash_genid++;
614                 write_unlock_bh(&fib_hash_lock);
615
616                 if (fa->fa_state & FA_S_ACCESSED)
617                         rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
618                 fn_free_alias(fa, f);
619                 if (kill_fn) {
620                         fn_free_node(f);
621                         fz->fz_nent--;
622                 }
623
624                 return 0;
625         }
626         return -ESRCH;
627 }
628
629 static int fn_flush_list(struct fn_zone *fz, int idx)
630 {
631         struct hlist_head *head = &fz->fz_hash[idx];
632         struct hlist_node *node, *n;
633         struct fib_node *f;
634         int found = 0;
635
636         hlist_for_each_entry_safe(f, node, n, head, fn_hash) {
637                 struct fib_alias *fa, *fa_node;
638                 int kill_f;
639
640                 kill_f = 0;
641                 list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) {
642                         struct fib_info *fi = fa->fa_info;
643
644                         if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
645                                 write_lock_bh(&fib_hash_lock);
646                                 list_del(&fa->fa_list);
647                                 if (list_empty(&f->fn_alias)) {
648                                         hlist_del(&f->fn_hash);
649                                         kill_f = 1;
650                                 }
651                                 fib_hash_genid++;
652                                 write_unlock_bh(&fib_hash_lock);
653
654                                 fn_free_alias(fa, f);
655                                 found++;
656                         }
657                 }
658                 if (kill_f) {
659                         fn_free_node(f);
660                         fz->fz_nent--;
661                 }
662         }
663         return found;
664 }
665
666 static int fn_hash_flush(struct fib_table *tb)
667 {
668         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
669         struct fn_zone *fz;
670         int found = 0;
671
672         for (fz = table->fn_zone_list; fz; fz = fz->fz_next) {
673                 int i;
674
675                 for (i = fz->fz_divisor - 1; i >= 0; i--)
676                         found += fn_flush_list(fz, i);
677         }
678         return found;
679 }
680
681
682 static inline int
683 fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
684                      struct fib_table *tb,
685                      struct fn_zone *fz,
686                      struct hlist_head *head)
687 {
688         struct hlist_node *node;
689         struct fib_node *f;
690         int i, s_i;
691
692         s_i = cb->args[4];
693         i = 0;
694         hlist_for_each_entry(f, node, head, fn_hash) {
695                 struct fib_alias *fa;
696
697                 list_for_each_entry(fa, &f->fn_alias, fa_list) {
698                         if (i < s_i)
699                                 goto next;
700
701                         if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
702                                           cb->nlh->nlmsg_seq,
703                                           RTM_NEWROUTE,
704                                           tb->tb_id,
705                                           fa->fa_type,
706                                           fa->fa_scope,
707                                           f->fn_key,
708                                           fz->fz_order,
709                                           fa->fa_tos,
710                                           fa->fa_info,
711                                           NLM_F_MULTI) < 0) {
712                                 cb->args[4] = i;
713                                 return -1;
714                         }
715                 next:
716                         i++;
717                 }
718         }
719         cb->args[4] = i;
720         return skb->len;
721 }
722
723 static inline int
724 fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
725                    struct fib_table *tb,
726                    struct fn_zone *fz)
727 {
728         int h, s_h;
729
730         if (fz->fz_hash == NULL)
731                 return skb->len;
732         s_h = cb->args[3];
733         for (h = s_h; h < fz->fz_divisor; h++) {
734                 if (hlist_empty(&fz->fz_hash[h]))
735                         continue;
736                 if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h]) < 0) {
737                         cb->args[3] = h;
738                         return -1;
739                 }
740                 memset(&cb->args[4], 0,
741                        sizeof(cb->args) - 4*sizeof(cb->args[0]));
742         }
743         cb->args[3] = h;
744         return skb->len;
745 }
746
747 static int fn_hash_dump(struct fib_table *tb, struct sk_buff *skb, struct netlink_callback *cb)
748 {
749         int m, s_m;
750         struct fn_zone *fz;
751         struct fn_hash *table = (struct fn_hash*)tb->tb_data;
752
753         s_m = cb->args[2];
754         read_lock(&fib_hash_lock);
755         for (fz = table->fn_zone_list, m=0; fz; fz = fz->fz_next, m++) {
756                 if (m < s_m) continue;
757                 if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
758                         cb->args[2] = m;
759                         read_unlock(&fib_hash_lock);
760                         return -1;
761                 }
762                 memset(&cb->args[3], 0,
763                        sizeof(cb->args) - 3*sizeof(cb->args[0]));
764         }
765         read_unlock(&fib_hash_lock);
766         cb->args[2] = m;
767         return skb->len;
768 }
769
770 void __init fib_hash_init(void)
771 {
772         fn_hash_kmem = kmem_cache_create("ip_fib_hash", sizeof(struct fib_node),
773                                          0, SLAB_PANIC, NULL);
774
775         fn_alias_kmem = kmem_cache_create("ip_fib_alias", sizeof(struct fib_alias),
776                                           0, SLAB_PANIC, NULL);
777
778 }
779
780 struct fib_table *fib_hash_table(u32 id)
781 {
782         struct fib_table *tb;
783
784         tb = kmalloc(sizeof(struct fib_table) + sizeof(struct fn_hash),
785                      GFP_KERNEL);
786         if (tb == NULL)
787                 return NULL;
788
789         tb->tb_id = id;
790         tb->tb_default = -1;
791         tb->tb_lookup = fn_hash_lookup;
792         tb->tb_insert = fn_hash_insert;
793         tb->tb_delete = fn_hash_delete;
794         tb->tb_flush = fn_hash_flush;
795         tb->tb_select_default = fn_hash_select_default;
796         tb->tb_dump = fn_hash_dump;
797         memset(tb->tb_data, 0, sizeof(struct fn_hash));
798         return tb;
799 }
800
801 /* ------------------------------------------------------------------------ */
802 #ifdef CONFIG_PROC_FS
803
804 struct fib_iter_state {
805         struct seq_net_private p;
806         struct fn_zone  *zone;
807         int             bucket;
808         struct hlist_head *hash_head;
809         struct fib_node *fn;
810         struct fib_alias *fa;
811         loff_t pos;
812         unsigned int genid;
813         int valid;
814 };
815
816 static struct fib_alias *fib_get_first(struct seq_file *seq)
817 {
818         struct fib_iter_state *iter = seq->private;
819         struct fib_table *main_table;
820         struct fn_hash *table;
821
822         main_table = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
823         table = (struct fn_hash *)main_table->tb_data;
824
825         iter->bucket    = 0;
826         iter->hash_head = NULL;
827         iter->fn        = NULL;
828         iter->fa        = NULL;
829         iter->pos       = 0;
830         iter->genid     = fib_hash_genid;
831         iter->valid     = 1;
832
833         for (iter->zone = table->fn_zone_list; iter->zone;
834              iter->zone = iter->zone->fz_next) {
835                 int maxslot;
836
837                 if (!iter->zone->fz_nent)
838                         continue;
839
840                 iter->hash_head = iter->zone->fz_hash;
841                 maxslot = iter->zone->fz_divisor;
842
843                 for (iter->bucket = 0; iter->bucket < maxslot;
844                      ++iter->bucket, ++iter->hash_head) {
845                         struct hlist_node *node;
846                         struct fib_node *fn;
847
848                         hlist_for_each_entry(fn,node,iter->hash_head,fn_hash) {
849                                 struct fib_alias *fa;
850
851                                 list_for_each_entry(fa,&fn->fn_alias,fa_list) {
852                                         iter->fn = fn;
853                                         iter->fa = fa;
854                                         goto out;
855                                 }
856                         }
857                 }
858         }
859 out:
860         return iter->fa;
861 }
862
863 static struct fib_alias *fib_get_next(struct seq_file *seq)
864 {
865         struct fib_iter_state *iter = seq->private;
866         struct fib_node *fn;
867         struct fib_alias *fa;
868
869         /* Advance FA, if any. */
870         fn = iter->fn;
871         fa = iter->fa;
872         if (fa) {
873                 BUG_ON(!fn);
874                 list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) {
875                         iter->fa = fa;
876                         goto out;
877                 }
878         }
879
880         fa = iter->fa = NULL;
881
882         /* Advance FN. */
883         if (fn) {
884                 struct hlist_node *node = &fn->fn_hash;
885                 hlist_for_each_entry_continue(fn, node, fn_hash) {
886                         iter->fn = fn;
887
888                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
889                                 iter->fa = fa;
890                                 goto out;
891                         }
892                 }
893         }
894
895         fn = iter->fn = NULL;
896
897         /* Advance hash chain. */
898         if (!iter->zone)
899                 goto out;
900
901         for (;;) {
902                 struct hlist_node *node;
903                 int maxslot;
904
905                 maxslot = iter->zone->fz_divisor;
906
907                 while (++iter->bucket < maxslot) {
908                         iter->hash_head++;
909
910                         hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
911                                 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
912                                         iter->fn = fn;
913                                         iter->fa = fa;
914                                         goto out;
915                                 }
916                         }
917                 }
918
919                 iter->zone = iter->zone->fz_next;
920
921                 if (!iter->zone)
922                         goto out;
923
924                 iter->bucket = 0;
925                 iter->hash_head = iter->zone->fz_hash;
926
927                 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
928                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
929                                 iter->fn = fn;
930                                 iter->fa = fa;
931                                 goto out;
932                         }
933                 }
934         }
935 out:
936         iter->pos++;
937         return fa;
938 }
939
940 static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos)
941 {
942         struct fib_iter_state *iter = seq->private;
943         struct fib_alias *fa;
944
945         if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) {
946                 fa   = iter->fa;
947                 pos -= iter->pos;
948         } else
949                 fa = fib_get_first(seq);
950
951         if (fa)
952                 while (pos && (fa = fib_get_next(seq)))
953                         --pos;
954         return pos ? NULL : fa;
955 }
956
957 static void *fib_seq_start(struct seq_file *seq, loff_t *pos)
958         __acquires(fib_hash_lock)
959 {
960         void *v = NULL;
961
962         read_lock(&fib_hash_lock);
963         if (fib_get_table(seq_file_net(seq), RT_TABLE_MAIN))
964                 v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
965         return v;
966 }
967
968 static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
969 {
970         ++*pos;
971         return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
972 }
973
974 static void fib_seq_stop(struct seq_file *seq, void *v)
975         __releases(fib_hash_lock)
976 {
977         read_unlock(&fib_hash_lock);
978 }
979
980 static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
981 {
982         static const unsigned type2flags[RTN_MAX + 1] = {
983                 [7] = RTF_REJECT, [8] = RTF_REJECT,
984         };
985         unsigned flags = type2flags[type];
986
987         if (fi && fi->fib_nh->nh_gw)
988                 flags |= RTF_GATEWAY;
989         if (mask == htonl(0xFFFFFFFF))
990                 flags |= RTF_HOST;
991         flags |= RTF_UP;
992         return flags;
993 }
994
995 /*
996  *      This outputs /proc/net/route.
997  *
998  *      It always works in backward compatibility mode.
999  *      The format of the file is not supposed to be changed.
1000  */
1001 static int fib_seq_show(struct seq_file *seq, void *v)
1002 {
1003         struct fib_iter_state *iter;
1004         int len;
1005         __be32 prefix, mask;
1006         unsigned flags;
1007         struct fib_node *f;
1008         struct fib_alias *fa;
1009         struct fib_info *fi;
1010
1011         if (v == SEQ_START_TOKEN) {
1012                 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
1013                            "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
1014                            "\tWindow\tIRTT");
1015                 goto out;
1016         }
1017
1018         iter    = seq->private;
1019         f       = iter->fn;
1020         fa      = iter->fa;
1021         fi      = fa->fa_info;
1022         prefix  = f->fn_key;
1023         mask    = FZ_MASK(iter->zone);
1024         flags   = fib_flag_trans(fa->fa_type, mask, fi);
1025         if (fi)
1026                 seq_printf(seq,
1027                          "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
1028                          fi->fib_dev ? fi->fib_dev->name : "*", prefix,
1029                          fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
1030                          mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
1031                          fi->fib_window,
1032                          fi->fib_rtt >> 3, &len);
1033         else
1034                 seq_printf(seq,
1035                          "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
1036                          prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0, &len);
1037
1038         seq_printf(seq, "%*s\n", 127 - len, "");
1039 out:
1040         return 0;
1041 }
1042
1043 static const struct seq_operations fib_seq_ops = {
1044         .start  = fib_seq_start,
1045         .next   = fib_seq_next,
1046         .stop   = fib_seq_stop,
1047         .show   = fib_seq_show,
1048 };
1049
1050 static int fib_seq_open(struct inode *inode, struct file *file)
1051 {
1052         return seq_open_net(inode, file, &fib_seq_ops,
1053                             sizeof(struct fib_iter_state));
1054 }
1055
1056 static const struct file_operations fib_seq_fops = {
1057         .owner          = THIS_MODULE,
1058         .open           = fib_seq_open,
1059         .read           = seq_read,
1060         .llseek         = seq_lseek,
1061         .release        = seq_release_net,
1062 };
1063
1064 int __net_init fib_proc_init(struct net *net)
1065 {
1066         if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_seq_fops))
1067                 return -ENOMEM;
1068         return 0;
1069 }
1070
1071 void __net_exit fib_proc_exit(struct net *net)
1072 {
1073         proc_net_remove(net, "route");
1074 }
1075 #endif /* CONFIG_PROC_FS */