[IPSEC]: Do not let packets pass when ICMP flag is off
[linux-2.6] / net / ipv4 / fib_hash.c
1 /*
2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
3  *              operating system.  INET is implemented using the  BSD Socket
4  *              interface as the means of communication with the user level.
5  *
6  *              IPv4 FIB: lookup engine and maintenance routines.
7  *
8  * Version:     $Id: fib_hash.c,v 1.13 2001/10/31 21:55:54 davem Exp $
9  *
10  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
11  *
12  *              This program is free software; you can redistribute it and/or
13  *              modify it under the terms of the GNU General Public License
14  *              as published by the Free Software Foundation; either version
15  *              2 of the License, or (at your option) any later version.
16  */
17
18 #include <asm/uaccess.h>
19 #include <asm/system.h>
20 #include <linux/bitops.h>
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/mm.h>
24 #include <linux/string.h>
25 #include <linux/socket.h>
26 #include <linux/sockios.h>
27 #include <linux/errno.h>
28 #include <linux/in.h>
29 #include <linux/inet.h>
30 #include <linux/inetdevice.h>
31 #include <linux/netdevice.h>
32 #include <linux/if_arp.h>
33 #include <linux/proc_fs.h>
34 #include <linux/skbuff.h>
35 #include <linux/netlink.h>
36 #include <linux/init.h>
37
38 #include <net/net_namespace.h>
39 #include <net/ip.h>
40 #include <net/protocol.h>
41 #include <net/route.h>
42 #include <net/tcp.h>
43 #include <net/sock.h>
44 #include <net/ip_fib.h>
45
46 #include "fib_lookup.h"
47
48 static struct kmem_cache *fn_hash_kmem __read_mostly;
49 static struct kmem_cache *fn_alias_kmem __read_mostly;
50
51 struct fib_node {
52         struct hlist_node       fn_hash;
53         struct list_head        fn_alias;
54         __be32                  fn_key;
55 };
56
57 struct fn_zone {
58         struct fn_zone          *fz_next;       /* Next not empty zone  */
59         struct hlist_head       *fz_hash;       /* Hash table pointer   */
60         int                     fz_nent;        /* Number of entries    */
61
62         int                     fz_divisor;     /* Hash divisor         */
63         u32                     fz_hashmask;    /* (fz_divisor - 1)     */
64 #define FZ_HASHMASK(fz)         ((fz)->fz_hashmask)
65
66         int                     fz_order;       /* Zone order           */
67         __be32                  fz_mask;
68 #define FZ_MASK(fz)             ((fz)->fz_mask)
69 };
70
71 /* NOTE. On fast computers evaluation of fz_hashmask and fz_mask
72  * can be cheaper than memory lookup, so that FZ_* macros are used.
73  */
74
75 struct fn_hash {
76         struct fn_zone  *fn_zones[33];
77         struct fn_zone  *fn_zone_list;
78 };
79
80 static inline u32 fn_hash(__be32 key, struct fn_zone *fz)
81 {
82         u32 h = ntohl(key)>>(32 - fz->fz_order);
83         h ^= (h>>20);
84         h ^= (h>>10);
85         h ^= (h>>5);
86         h &= FZ_HASHMASK(fz);
87         return h;
88 }
89
90 static inline __be32 fz_key(__be32 dst, struct fn_zone *fz)
91 {
92         return dst & FZ_MASK(fz);
93 }
94
95 static DEFINE_RWLOCK(fib_hash_lock);
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         } else {
107                 return (struct hlist_head *)
108                         __get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(size));
109         }
110 }
111
112 /* The fib hash lock must be held when this is called. */
113 static inline void fn_rebuild_zone(struct fn_zone *fz,
114                                    struct hlist_head *old_ht,
115                                    int old_divisor)
116 {
117         int i;
118
119         for (i = 0; i < old_divisor; i++) {
120                 struct hlist_node *node, *n;
121                 struct fib_node *f;
122
123                 hlist_for_each_entry_safe(f, node, n, &old_ht[i], fn_hash) {
124                         struct hlist_head *new_head;
125
126                         hlist_del(&f->fn_hash);
127
128                         new_head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
129                         hlist_add_head(&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         old_divisor = fz->fz_divisor;
151
152         switch (old_divisor) {
153         case 16:
154                 new_divisor = 256;
155                 break;
156         case 256:
157                 new_divisor = 1024;
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("fn_rehash_zone: hash for zone %d grows from %d\n", 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)
196 {
197         fib_release_info(fa->fa_info);
198         kmem_cache_free(fn_alias_kmem, fa);
199 }
200
201 static struct fn_zone *
202 fn_new_zone(struct fn_hash *table, int z)
203 {
204         int i;
205         struct fn_zone *fz = kzalloc(sizeof(struct fn_zone), GFP_KERNEL);
206         if (!fz)
207                 return NULL;
208
209         if (z) {
210                 fz->fz_divisor = 16;
211         } else {
212                 fz->fz_divisor = 1;
213         }
214         fz->fz_hashmask = (fz->fz_divisor - 1);
215         fz->fz_hash = fz_hash_alloc(fz->fz_divisor);
216         if (!fz->fz_hash) {
217                 kfree(fz);
218                 return NULL;
219         }
220         fz->fz_order = z;
221         fz->fz_mask = inet_make_mask(z);
222
223         /* Find the first not empty zone with more specific mask */
224         for (i=z+1; i<=32; i++)
225                 if (table->fn_zones[i])
226                         break;
227         write_lock_bh(&fib_hash_lock);
228         if (i>32) {
229                 /* No more specific masks, we are the first. */
230                 fz->fz_next = table->fn_zone_list;
231                 table->fn_zone_list = fz;
232         } else {
233                 fz->fz_next = table->fn_zones[i]->fz_next;
234                 table->fn_zones[i]->fz_next = fz;
235         }
236         table->fn_zones[z] = fz;
237         fib_hash_genid++;
238         write_unlock_bh(&fib_hash_lock);
239         return fz;
240 }
241
242 static int
243 fn_hash_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
244 {
245         int err;
246         struct fn_zone *fz;
247         struct fn_hash *t = (struct fn_hash*)tb->tb_data;
248
249         read_lock(&fib_hash_lock);
250         for (fz = t->fn_zone_list; fz; fz = fz->fz_next) {
251                 struct hlist_head *head;
252                 struct hlist_node *node;
253                 struct fib_node *f;
254                 __be32 k = fz_key(flp->fl4_dst, fz);
255
256                 head = &fz->fz_hash[fn_hash(k, fz)];
257                 hlist_for_each_entry(f, node, head, fn_hash) {
258                         if (f->fn_key != k)
259                                 continue;
260
261                         err = fib_semantic_match(&f->fn_alias,
262                                                  flp, res,
263                                                  f->fn_key, fz->fz_mask,
264                                                  fz->fz_order);
265                         if (err <= 0)
266                                 goto out;
267                 }
268         }
269         err = 1;
270 out:
271         read_unlock(&fib_hash_lock);
272         return err;
273 }
274
275 static void
276 fn_hash_select_default(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
277 {
278         int order, last_idx;
279         struct hlist_node *node;
280         struct fib_node *f;
281         struct fib_info *fi = NULL;
282         struct fib_info *last_resort;
283         struct fn_hash *t = (struct fn_hash*)tb->tb_data;
284         struct fn_zone *fz = t->fn_zones[0];
285
286         if (fz == NULL)
287                 return;
288
289         last_idx = -1;
290         last_resort = NULL;
291         order = -1;
292
293         read_lock(&fib_hash_lock);
294         hlist_for_each_entry(f, node, &fz->fz_hash[0], fn_hash) {
295                 struct fib_alias *fa;
296
297                 list_for_each_entry(fa, &f->fn_alias, fa_list) {
298                         struct fib_info *next_fi = fa->fa_info;
299
300                         if (fa->fa_scope != res->scope ||
301                             fa->fa_type != RTN_UNICAST)
302                                 continue;
303
304                         if (next_fi->fib_priority > res->fi->fib_priority)
305                                 break;
306                         if (!next_fi->fib_nh[0].nh_gw ||
307                             next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
308                                 continue;
309                         fa->fa_state |= FA_S_ACCESSED;
310
311                         if (fi == NULL) {
312                                 if (next_fi != res->fi)
313                                         break;
314                         } else if (!fib_detect_death(fi, order, &last_resort,
315                                                 &last_idx, tb->tb_default)) {
316                                 fib_result_assign(res, fi);
317                                 tb->tb_default = order;
318                                 goto out;
319                         }
320                         fi = next_fi;
321                         order++;
322                 }
323         }
324
325         if (order <= 0 || fi == NULL) {
326                 tb->tb_default = -1;
327                 goto out;
328         }
329
330         if (!fib_detect_death(fi, order, &last_resort, &last_idx,
331                                 tb->tb_default)) {
332                 fib_result_assign(res, fi);
333                 tb->tb_default = order;
334                 goto out;
335         }
336
337         if (last_idx >= 0)
338                 fib_result_assign(res, last_resort);
339         tb->tb_default = last_idx;
340 out:
341         read_unlock(&fib_hash_lock);
342 }
343
344 /* Insert node F to FZ. */
345 static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
346 {
347         struct hlist_head *head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
348
349         hlist_add_head(&f->fn_hash, head);
350 }
351
352 /* Return the node in FZ matching KEY. */
353 static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key)
354 {
355         struct hlist_head *head = &fz->fz_hash[fn_hash(key, fz)];
356         struct hlist_node *node;
357         struct fib_node *f;
358
359         hlist_for_each_entry(f, node, head, fn_hash) {
360                 if (f->fn_key == key)
361                         return f;
362         }
363
364         return NULL;
365 }
366
367 static int fn_hash_insert(struct fib_table *tb, struct fib_config *cfg)
368 {
369         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
370         struct fib_node *new_f, *f;
371         struct fib_alias *fa, *new_fa;
372         struct fn_zone *fz;
373         struct fib_info *fi;
374         u8 tos = cfg->fc_tos;
375         __be32 key;
376         int err;
377
378         if (cfg->fc_dst_len > 32)
379                 return -EINVAL;
380
381         fz = table->fn_zones[cfg->fc_dst_len];
382         if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len)))
383                 return -ENOBUFS;
384
385         key = 0;
386         if (cfg->fc_dst) {
387                 if (cfg->fc_dst & ~FZ_MASK(fz))
388                         return -EINVAL;
389                 key = fz_key(cfg->fc_dst, fz);
390         }
391
392         fi = fib_create_info(cfg);
393         if (IS_ERR(fi))
394                 return PTR_ERR(fi);
395
396         if (fz->fz_nent > (fz->fz_divisor<<1) &&
397             fz->fz_divisor < FZ_MAX_DIVISOR &&
398             (cfg->fc_dst_len == 32 ||
399              (1 << cfg->fc_dst_len) > fz->fz_divisor))
400                 fn_rehash_zone(fz);
401
402         f = fib_find_node(fz, key);
403
404         if (!f)
405                 fa = NULL;
406         else
407                 fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority);
408
409         /* Now fa, if non-NULL, points to the first fib alias
410          * with the same keys [prefix,tos,priority], if such key already
411          * exists or to the node before which we will insert new one.
412          *
413          * If fa is NULL, we will need to allocate a new one and
414          * insert to the head of f.
415          *
416          * If f is NULL, no fib node matched the destination key
417          * and we need to allocate a new one of those as well.
418          */
419
420         if (fa && fa->fa_tos == tos &&
421             fa->fa_info->fib_priority == fi->fib_priority) {
422                 struct fib_alias *fa_orig;
423
424                 err = -EEXIST;
425                 if (cfg->fc_nlflags & NLM_F_EXCL)
426                         goto out;
427
428                 if (cfg->fc_nlflags & NLM_F_REPLACE) {
429                         struct fib_info *fi_drop;
430                         u8 state;
431
432                         if (fi->fib_treeref > 1)
433                                 goto out;
434
435                         write_lock_bh(&fib_hash_lock);
436                         fi_drop = fa->fa_info;
437                         fa->fa_info = fi;
438                         fa->fa_type = cfg->fc_type;
439                         fa->fa_scope = cfg->fc_scope;
440                         state = fa->fa_state;
441                         fa->fa_state &= ~FA_S_ACCESSED;
442                         fib_hash_genid++;
443                         write_unlock_bh(&fib_hash_lock);
444
445                         fib_release_info(fi_drop);
446                         if (state & FA_S_ACCESSED)
447                                 rt_cache_flush(-1);
448                         rtmsg_fib(RTM_NEWROUTE, key, fa, cfg->fc_dst_len, tb->tb_id,
449                                   &cfg->fc_nlinfo, NLM_F_REPLACE);
450                         return 0;
451                 }
452
453                 /* Error if we find a perfect match which
454                  * uses the same scope, type, and nexthop
455                  * information.
456                  */
457                 fa_orig = fa;
458                 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
459                 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
460                         if (fa->fa_tos != tos)
461                                 break;
462                         if (fa->fa_info->fib_priority != fi->fib_priority)
463                                 break;
464                         if (fa->fa_type == cfg->fc_type &&
465                             fa->fa_scope == cfg->fc_scope &&
466                             fa->fa_info == fi)
467                                 goto out;
468                 }
469                 if (!(cfg->fc_nlflags & NLM_F_APPEND))
470                         fa = fa_orig;
471         }
472
473         err = -ENOENT;
474         if (!(cfg->fc_nlflags & NLM_F_CREATE))
475                 goto out;
476
477         err = -ENOBUFS;
478         new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
479         if (new_fa == NULL)
480                 goto out;
481
482         new_f = NULL;
483         if (!f) {
484                 new_f = kmem_cache_alloc(fn_hash_kmem, GFP_KERNEL);
485                 if (new_f == NULL)
486                         goto out_free_new_fa;
487
488                 INIT_HLIST_NODE(&new_f->fn_hash);
489                 INIT_LIST_HEAD(&new_f->fn_alias);
490                 new_f->fn_key = key;
491                 f = new_f;
492         }
493
494         new_fa->fa_info = fi;
495         new_fa->fa_tos = tos;
496         new_fa->fa_type = cfg->fc_type;
497         new_fa->fa_scope = cfg->fc_scope;
498         new_fa->fa_state = 0;
499
500         /*
501          * Insert new entry to the list.
502          */
503
504         write_lock_bh(&fib_hash_lock);
505         if (new_f)
506                 fib_insert_node(fz, new_f);
507         list_add_tail(&new_fa->fa_list,
508                  (fa ? &fa->fa_list : &f->fn_alias));
509         fib_hash_genid++;
510         write_unlock_bh(&fib_hash_lock);
511
512         if (new_f)
513                 fz->fz_nent++;
514         rt_cache_flush(-1);
515
516         rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id,
517                   &cfg->fc_nlinfo, 0);
518         return 0;
519
520 out_free_new_fa:
521         kmem_cache_free(fn_alias_kmem, new_fa);
522 out:
523         fib_release_info(fi);
524         return err;
525 }
526
527
528 static int fn_hash_delete(struct fib_table *tb, struct fib_config *cfg)
529 {
530         struct fn_hash *table = (struct fn_hash*)tb->tb_data;
531         struct fib_node *f;
532         struct fib_alias *fa, *fa_to_delete;
533         struct fn_zone *fz;
534         __be32 key;
535
536         if (cfg->fc_dst_len > 32)
537                 return -EINVAL;
538
539         if ((fz  = table->fn_zones[cfg->fc_dst_len]) == NULL)
540                 return -ESRCH;
541
542         key = 0;
543         if (cfg->fc_dst) {
544                 if (cfg->fc_dst & ~FZ_MASK(fz))
545                         return -EINVAL;
546                 key = fz_key(cfg->fc_dst, fz);
547         }
548
549         f = fib_find_node(fz, key);
550
551         if (!f)
552                 fa = NULL;
553         else
554                 fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0);
555         if (!fa)
556                 return -ESRCH;
557
558         fa_to_delete = NULL;
559         fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
560         list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
561                 struct fib_info *fi = fa->fa_info;
562
563                 if (fa->fa_tos != cfg->fc_tos)
564                         break;
565
566                 if ((!cfg->fc_type ||
567                      fa->fa_type == cfg->fc_type) &&
568                     (cfg->fc_scope == RT_SCOPE_NOWHERE ||
569                      fa->fa_scope == cfg->fc_scope) &&
570                     (!cfg->fc_protocol ||
571                      fi->fib_protocol == cfg->fc_protocol) &&
572                     fib_nh_match(cfg, fi) == 0) {
573                         fa_to_delete = fa;
574                         break;
575                 }
576         }
577
578         if (fa_to_delete) {
579                 int kill_fn;
580
581                 fa = fa_to_delete;
582                 rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len,
583                           tb->tb_id, &cfg->fc_nlinfo, 0);
584
585                 kill_fn = 0;
586                 write_lock_bh(&fib_hash_lock);
587                 list_del(&fa->fa_list);
588                 if (list_empty(&f->fn_alias)) {
589                         hlist_del(&f->fn_hash);
590                         kill_fn = 1;
591                 }
592                 fib_hash_genid++;
593                 write_unlock_bh(&fib_hash_lock);
594
595                 if (fa->fa_state & FA_S_ACCESSED)
596                         rt_cache_flush(-1);
597                 fn_free_alias(fa);
598                 if (kill_fn) {
599                         fn_free_node(f);
600                         fz->fz_nent--;
601                 }
602
603                 return 0;
604         }
605         return -ESRCH;
606 }
607
608 static int fn_flush_list(struct fn_zone *fz, int idx)
609 {
610         struct hlist_head *head = &fz->fz_hash[idx];
611         struct hlist_node *node, *n;
612         struct fib_node *f;
613         int found = 0;
614
615         hlist_for_each_entry_safe(f, node, n, head, fn_hash) {
616                 struct fib_alias *fa, *fa_node;
617                 int kill_f;
618
619                 kill_f = 0;
620                 list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) {
621                         struct fib_info *fi = fa->fa_info;
622
623                         if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
624                                 write_lock_bh(&fib_hash_lock);
625                                 list_del(&fa->fa_list);
626                                 if (list_empty(&f->fn_alias)) {
627                                         hlist_del(&f->fn_hash);
628                                         kill_f = 1;
629                                 }
630                                 fib_hash_genid++;
631                                 write_unlock_bh(&fib_hash_lock);
632
633                                 fn_free_alias(fa);
634                                 found++;
635                         }
636                 }
637                 if (kill_f) {
638                         fn_free_node(f);
639                         fz->fz_nent--;
640                 }
641         }
642         return found;
643 }
644
645 static int fn_hash_flush(struct fib_table *tb)
646 {
647         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
648         struct fn_zone *fz;
649         int found = 0;
650
651         for (fz = table->fn_zone_list; fz; fz = fz->fz_next) {
652                 int i;
653
654                 for (i = fz->fz_divisor - 1; i >= 0; i--)
655                         found += fn_flush_list(fz, i);
656         }
657         return found;
658 }
659
660
661 static inline int
662 fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
663                      struct fib_table *tb,
664                      struct fn_zone *fz,
665                      struct hlist_head *head)
666 {
667         struct hlist_node *node;
668         struct fib_node *f;
669         int i, s_i;
670
671         s_i = cb->args[4];
672         i = 0;
673         hlist_for_each_entry(f, node, head, fn_hash) {
674                 struct fib_alias *fa;
675
676                 list_for_each_entry(fa, &f->fn_alias, fa_list) {
677                         if (i < s_i)
678                                 goto next;
679
680                         if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
681                                           cb->nlh->nlmsg_seq,
682                                           RTM_NEWROUTE,
683                                           tb->tb_id,
684                                           fa->fa_type,
685                                           fa->fa_scope,
686                                           f->fn_key,
687                                           fz->fz_order,
688                                           fa->fa_tos,
689                                           fa->fa_info,
690                                           NLM_F_MULTI) < 0) {
691                                 cb->args[4] = i;
692                                 return -1;
693                         }
694                 next:
695                         i++;
696                 }
697         }
698         cb->args[4] = i;
699         return skb->len;
700 }
701
702 static inline int
703 fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
704                    struct fib_table *tb,
705                    struct fn_zone *fz)
706 {
707         int h, s_h;
708
709         if (fz->fz_hash == NULL)
710                 return skb->len;
711         s_h = cb->args[3];
712         for (h = s_h; h < fz->fz_divisor; h++) {
713                 if (hlist_empty(&fz->fz_hash[h]))
714                         continue;
715                 if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h]) < 0) {
716                         cb->args[3] = h;
717                         return -1;
718                 }
719                 memset(&cb->args[4], 0,
720                        sizeof(cb->args) - 4*sizeof(cb->args[0]));
721         }
722         cb->args[3] = h;
723         return skb->len;
724 }
725
726 static int fn_hash_dump(struct fib_table *tb, struct sk_buff *skb, struct netlink_callback *cb)
727 {
728         int m, s_m;
729         struct fn_zone *fz;
730         struct fn_hash *table = (struct fn_hash*)tb->tb_data;
731
732         s_m = cb->args[2];
733         read_lock(&fib_hash_lock);
734         for (fz = table->fn_zone_list, m=0; fz; fz = fz->fz_next, m++) {
735                 if (m < s_m) continue;
736                 if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
737                         cb->args[2] = m;
738                         read_unlock(&fib_hash_lock);
739                         return -1;
740                 }
741                 memset(&cb->args[3], 0,
742                        sizeof(cb->args) - 3*sizeof(cb->args[0]));
743         }
744         read_unlock(&fib_hash_lock);
745         cb->args[2] = m;
746         return skb->len;
747 }
748
749 #ifdef CONFIG_IP_MULTIPLE_TABLES
750 struct fib_table * fib_hash_init(u32 id)
751 #else
752 struct fib_table * __init fib_hash_init(u32 id)
753 #endif
754 {
755         struct fib_table *tb;
756
757         if (fn_hash_kmem == NULL)
758                 fn_hash_kmem = kmem_cache_create("ip_fib_hash",
759                                                  sizeof(struct fib_node),
760                                                  0, SLAB_HWCACHE_ALIGN,
761                                                  NULL);
762
763         if (fn_alias_kmem == NULL)
764                 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
765                                                   sizeof(struct fib_alias),
766                                                   0, SLAB_HWCACHE_ALIGN,
767                                                   NULL);
768
769         tb = kmalloc(sizeof(struct fib_table) + sizeof(struct fn_hash),
770                      GFP_KERNEL);
771         if (tb == NULL)
772                 return NULL;
773
774         tb->tb_id = id;
775         tb->tb_default = -1;
776         tb->tb_lookup = fn_hash_lookup;
777         tb->tb_insert = fn_hash_insert;
778         tb->tb_delete = fn_hash_delete;
779         tb->tb_flush = fn_hash_flush;
780         tb->tb_select_default = fn_hash_select_default;
781         tb->tb_dump = fn_hash_dump;
782         memset(tb->tb_data, 0, sizeof(struct fn_hash));
783         return tb;
784 }
785
786 /* ------------------------------------------------------------------------ */
787 #ifdef CONFIG_PROC_FS
788
789 struct fib_iter_state {
790         struct fn_zone  *zone;
791         int             bucket;
792         struct hlist_head *hash_head;
793         struct fib_node *fn;
794         struct fib_alias *fa;
795         loff_t pos;
796         unsigned int genid;
797         int valid;
798 };
799
800 static struct fib_alias *fib_get_first(struct seq_file *seq)
801 {
802         struct fib_iter_state *iter = seq->private;
803         struct fib_table *main_table = fib_get_table(RT_TABLE_MAIN);
804         struct fn_hash *table = (struct fn_hash *)main_table->tb_data;
805
806         iter->bucket    = 0;
807         iter->hash_head = NULL;
808         iter->fn        = NULL;
809         iter->fa        = NULL;
810         iter->pos       = 0;
811         iter->genid     = fib_hash_genid;
812         iter->valid     = 1;
813
814         for (iter->zone = table->fn_zone_list; iter->zone;
815              iter->zone = iter->zone->fz_next) {
816                 int maxslot;
817
818                 if (!iter->zone->fz_nent)
819                         continue;
820
821                 iter->hash_head = iter->zone->fz_hash;
822                 maxslot = iter->zone->fz_divisor;
823
824                 for (iter->bucket = 0; iter->bucket < maxslot;
825                      ++iter->bucket, ++iter->hash_head) {
826                         struct hlist_node *node;
827                         struct fib_node *fn;
828
829                         hlist_for_each_entry(fn,node,iter->hash_head,fn_hash) {
830                                 struct fib_alias *fa;
831
832                                 list_for_each_entry(fa,&fn->fn_alias,fa_list) {
833                                         iter->fn = fn;
834                                         iter->fa = fa;
835                                         goto out;
836                                 }
837                         }
838                 }
839         }
840 out:
841         return iter->fa;
842 }
843
844 static struct fib_alias *fib_get_next(struct seq_file *seq)
845 {
846         struct fib_iter_state *iter = seq->private;
847         struct fib_node *fn;
848         struct fib_alias *fa;
849
850         /* Advance FA, if any. */
851         fn = iter->fn;
852         fa = iter->fa;
853         if (fa) {
854                 BUG_ON(!fn);
855                 list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) {
856                         iter->fa = fa;
857                         goto out;
858                 }
859         }
860
861         fa = iter->fa = NULL;
862
863         /* Advance FN. */
864         if (fn) {
865                 struct hlist_node *node = &fn->fn_hash;
866                 hlist_for_each_entry_continue(fn, node, fn_hash) {
867                         iter->fn = fn;
868
869                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
870                                 iter->fa = fa;
871                                 goto out;
872                         }
873                 }
874         }
875
876         fn = iter->fn = NULL;
877
878         /* Advance hash chain. */
879         if (!iter->zone)
880                 goto out;
881
882         for (;;) {
883                 struct hlist_node *node;
884                 int maxslot;
885
886                 maxslot = iter->zone->fz_divisor;
887
888                 while (++iter->bucket < maxslot) {
889                         iter->hash_head++;
890
891                         hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
892                                 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
893                                         iter->fn = fn;
894                                         iter->fa = fa;
895                                         goto out;
896                                 }
897                         }
898                 }
899
900                 iter->zone = iter->zone->fz_next;
901
902                 if (!iter->zone)
903                         goto out;
904
905                 iter->bucket = 0;
906                 iter->hash_head = iter->zone->fz_hash;
907
908                 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
909                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
910                                 iter->fn = fn;
911                                 iter->fa = fa;
912                                 goto out;
913                         }
914                 }
915         }
916 out:
917         iter->pos++;
918         return fa;
919 }
920
921 static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos)
922 {
923         struct fib_iter_state *iter = seq->private;
924         struct fib_alias *fa;
925
926         if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) {
927                 fa   = iter->fa;
928                 pos -= iter->pos;
929         } else
930                 fa = fib_get_first(seq);
931
932         if (fa)
933                 while (pos && (fa = fib_get_next(seq)))
934                         --pos;
935         return pos ? NULL : fa;
936 }
937
938 static void *fib_seq_start(struct seq_file *seq, loff_t *pos)
939 {
940         void *v = NULL;
941
942         read_lock(&fib_hash_lock);
943         if (fib_get_table(RT_TABLE_MAIN))
944                 v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
945         return v;
946 }
947
948 static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
949 {
950         ++*pos;
951         return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
952 }
953
954 static void fib_seq_stop(struct seq_file *seq, void *v)
955 {
956         read_unlock(&fib_hash_lock);
957 }
958
959 static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
960 {
961         static const unsigned type2flags[RTN_MAX + 1] = {
962                 [7] = RTF_REJECT, [8] = RTF_REJECT,
963         };
964         unsigned flags = type2flags[type];
965
966         if (fi && fi->fib_nh->nh_gw)
967                 flags |= RTF_GATEWAY;
968         if (mask == htonl(0xFFFFFFFF))
969                 flags |= RTF_HOST;
970         flags |= RTF_UP;
971         return flags;
972 }
973
974 /*
975  *      This outputs /proc/net/route.
976  *
977  *      It always works in backward compatibility mode.
978  *      The format of the file is not supposed to be changed.
979  */
980 static int fib_seq_show(struct seq_file *seq, void *v)
981 {
982         struct fib_iter_state *iter;
983         char bf[128];
984         __be32 prefix, mask;
985         unsigned flags;
986         struct fib_node *f;
987         struct fib_alias *fa;
988         struct fib_info *fi;
989
990         if (v == SEQ_START_TOKEN) {
991                 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
992                            "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
993                            "\tWindow\tIRTT");
994                 goto out;
995         }
996
997         iter    = seq->private;
998         f       = iter->fn;
999         fa      = iter->fa;
1000         fi      = fa->fa_info;
1001         prefix  = f->fn_key;
1002         mask    = FZ_MASK(iter->zone);
1003         flags   = fib_flag_trans(fa->fa_type, mask, fi);
1004         if (fi)
1005                 snprintf(bf, sizeof(bf),
1006                          "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
1007                          fi->fib_dev ? fi->fib_dev->name : "*", prefix,
1008                          fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
1009                          mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
1010                          fi->fib_window,
1011                          fi->fib_rtt >> 3);
1012         else
1013                 snprintf(bf, sizeof(bf),
1014                          "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
1015                          prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0);
1016         seq_printf(seq, "%-127s\n", bf);
1017 out:
1018         return 0;
1019 }
1020
1021 static const struct seq_operations fib_seq_ops = {
1022         .start  = fib_seq_start,
1023         .next   = fib_seq_next,
1024         .stop   = fib_seq_stop,
1025         .show   = fib_seq_show,
1026 };
1027
1028 static int fib_seq_open(struct inode *inode, struct file *file)
1029 {
1030         return seq_open_private(file, &fib_seq_ops,
1031                         sizeof(struct fib_iter_state));
1032 }
1033
1034 static const struct file_operations fib_seq_fops = {
1035         .owner          = THIS_MODULE,
1036         .open           = fib_seq_open,
1037         .read           = seq_read,
1038         .llseek         = seq_lseek,
1039         .release        = seq_release_private,
1040 };
1041
1042 int __init fib_proc_init(void)
1043 {
1044         if (!proc_net_fops_create(&init_net, "route", S_IRUGO, &fib_seq_fops))
1045                 return -ENOMEM;
1046         return 0;
1047 }
1048
1049 void __init fib_proc_exit(void)
1050 {
1051         proc_net_remove(&init_net, "route");
1052 }
1053 #endif /* CONFIG_PROC_FS */