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
fn_hash(__be32 key,struct fn_zone * fz)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
fz_key(__be32 dst,struct fn_zone * fz)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
fz_hash_alloc(int divisor)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. */
fn_rebuild_zone(struct fn_zone * fz,struct hlist_head * old_ht,int old_divisor)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
fz_hash_free(struct hlist_head * hash,int divisor)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
fn_rehash_zone(struct fn_zone * fz)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
fn_free_node(struct fib_node * f)190 static inline void fn_free_node(struct fib_node * f)
191 {
192 kmem_cache_free(fn_hash_kmem, f);
193 }
194
fn_free_alias(struct fib_alias * fa,struct fib_node * f)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 *
fn_new_zone(struct fn_hash * table,int z)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
fn_hash_lookup(struct fib_table * tb,const struct flowi * flp,struct fib_result * res)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
fn_hash_select_default(struct fib_table * tb,const struct flowi * flp,struct fib_result * res)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. */
fib_insert_node(struct fn_zone * fz,struct fib_node * f)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. */
fib_find_node(struct fn_zone * fz,__be32 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
fn_hash_insert(struct fib_table * tb,struct fib_config * cfg)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
fn_hash_delete(struct fib_table * tb,struct fib_config * cfg)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
fn_flush_list(struct fn_zone * fz,int idx)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
fn_hash_flush(struct fib_table * tb)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
fn_hash_dump_bucket(struct sk_buff * skb,struct netlink_callback * cb,struct fib_table * tb,struct fn_zone * fz,struct hlist_head * head)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
fn_hash_dump_zone(struct sk_buff * skb,struct netlink_callback * cb,struct fib_table * tb,struct fn_zone * fz)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
fn_hash_dump(struct fib_table * tb,struct sk_buff * skb,struct netlink_callback * cb)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
fib_hash_init(void)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
fib_hash_table(u32 id)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
fib_get_first(struct seq_file * seq)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
fib_get_next(struct seq_file * seq)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
fib_get_idx(struct seq_file * seq,loff_t pos)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
fib_seq_start(struct seq_file * seq,loff_t * pos)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
fib_seq_next(struct seq_file * seq,void * v,loff_t * pos)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
fib_seq_stop(struct seq_file * seq,void * v)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
fib_flag_trans(int type,__be32 mask,struct fib_info * fi)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 */
fib_seq_show(struct seq_file * seq,void * v)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
fib_seq_open(struct inode * inode,struct file * file)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
fib_proc_init(struct net * net)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
fib_proc_exit(struct net * net)1071 void __net_exit fib_proc_exit(struct net *net)
1072 {
1073 proc_net_remove(net, "route");
1074 }
1075 #endif /* CONFIG_PROC_FS */
1076