Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1ab1457c | 2 | * Linux INET6 implementation |
1da177e4 LT |
3 | * Forwarding Information Database |
4 | * | |
5 | * Authors: | |
1ab1457c | 6 | * Pedro Roque <roque@di.fc.ul.pt> |
1da177e4 LT |
7 | * |
8 | * $Id: ip6_fib.c,v 1.25 2001/10/31 21:55:55 davem Exp $ | |
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 | /* | |
17 | * Changes: | |
18 | * Yuji SEKIYA @USAGI: Support default route on router node; | |
19 | * remove ip6_null_entry from the top of | |
20 | * routing table. | |
c0bece9f | 21 | * Ville Nuorvala: Fixed routing subtrees. |
1da177e4 | 22 | */ |
1da177e4 LT |
23 | #include <linux/errno.h> |
24 | #include <linux/types.h> | |
25 | #include <linux/net.h> | |
26 | #include <linux/route.h> | |
27 | #include <linux/netdevice.h> | |
28 | #include <linux/in6.h> | |
29 | #include <linux/init.h> | |
c71099ac | 30 | #include <linux/list.h> |
1da177e4 LT |
31 | |
32 | #ifdef CONFIG_PROC_FS | |
33 | #include <linux/proc_fs.h> | |
34 | #endif | |
35 | ||
36 | #include <net/ipv6.h> | |
37 | #include <net/ndisc.h> | |
38 | #include <net/addrconf.h> | |
39 | ||
40 | #include <net/ip6_fib.h> | |
41 | #include <net/ip6_route.h> | |
42 | ||
43 | #define RT6_DEBUG 2 | |
44 | ||
45 | #if RT6_DEBUG >= 3 | |
46 | #define RT6_TRACE(x...) printk(KERN_DEBUG x) | |
47 | #else | |
48 | #define RT6_TRACE(x...) do { ; } while (0) | |
49 | #endif | |
50 | ||
51 | struct rt6_statistics rt6_stats; | |
52 | ||
e18b890b | 53 | static struct kmem_cache * fib6_node_kmem __read_mostly; |
1da177e4 LT |
54 | |
55 | enum fib_walk_state_t | |
56 | { | |
57 | #ifdef CONFIG_IPV6_SUBTREES | |
58 | FWS_S, | |
59 | #endif | |
60 | FWS_L, | |
61 | FWS_R, | |
62 | FWS_C, | |
63 | FWS_U | |
64 | }; | |
65 | ||
66 | struct fib6_cleaner_t | |
67 | { | |
68 | struct fib6_walker_t w; | |
69 | int (*func)(struct rt6_info *, void *arg); | |
70 | void *arg; | |
71 | }; | |
72 | ||
90d41122 | 73 | static DEFINE_RWLOCK(fib6_walker_lock); |
1da177e4 LT |
74 | |
75 | #ifdef CONFIG_IPV6_SUBTREES | |
76 | #define FWS_INIT FWS_S | |
1da177e4 LT |
77 | #else |
78 | #define FWS_INIT FWS_L | |
1da177e4 LT |
79 | #endif |
80 | ||
81 | static void fib6_prune_clones(struct fib6_node *fn, struct rt6_info *rt); | |
66729e18 | 82 | static struct rt6_info * fib6_find_prefix(struct fib6_node *fn); |
1da177e4 | 83 | static struct fib6_node * fib6_repair_tree(struct fib6_node *fn); |
90d41122 AB |
84 | static int fib6_walk(struct fib6_walker_t *w); |
85 | static int fib6_walk_continue(struct fib6_walker_t *w); | |
1da177e4 LT |
86 | |
87 | /* | |
88 | * A routing update causes an increase of the serial number on the | |
89 | * affected subtree. This allows for cached routes to be asynchronously | |
90 | * tested when modifications are made to the destination cache as a | |
91 | * result of redirects, path MTU changes, etc. | |
92 | */ | |
93 | ||
94 | static __u32 rt_sernum; | |
95 | ||
8d06afab | 96 | static DEFINE_TIMER(ip6_fib_timer, fib6_run_gc, 0, 0); |
1da177e4 | 97 | |
90d41122 | 98 | static struct fib6_walker_t fib6_walker_list = { |
1da177e4 | 99 | .prev = &fib6_walker_list, |
1ab1457c | 100 | .next = &fib6_walker_list, |
1da177e4 LT |
101 | }; |
102 | ||
103 | #define FOR_WALKERS(w) for ((w)=fib6_walker_list.next; (w) != &fib6_walker_list; (w)=(w)->next) | |
104 | ||
90d41122 AB |
105 | static inline void fib6_walker_link(struct fib6_walker_t *w) |
106 | { | |
107 | write_lock_bh(&fib6_walker_lock); | |
108 | w->next = fib6_walker_list.next; | |
109 | w->prev = &fib6_walker_list; | |
110 | w->next->prev = w; | |
111 | w->prev->next = w; | |
112 | write_unlock_bh(&fib6_walker_lock); | |
113 | } | |
114 | ||
115 | static inline void fib6_walker_unlink(struct fib6_walker_t *w) | |
116 | { | |
117 | write_lock_bh(&fib6_walker_lock); | |
118 | w->next->prev = w->prev; | |
119 | w->prev->next = w->next; | |
120 | w->prev = w->next = w; | |
121 | write_unlock_bh(&fib6_walker_lock); | |
122 | } | |
1da177e4 LT |
123 | static __inline__ u32 fib6_new_sernum(void) |
124 | { | |
125 | u32 n = ++rt_sernum; | |
126 | if ((__s32)n <= 0) | |
127 | rt_sernum = n = 1; | |
128 | return n; | |
129 | } | |
130 | ||
131 | /* | |
132 | * Auxiliary address test functions for the radix tree. | |
133 | * | |
1ab1457c | 134 | * These assume a 32bit processor (although it will work on |
1da177e4 LT |
135 | * 64bit processors) |
136 | */ | |
137 | ||
138 | /* | |
139 | * test bit | |
140 | */ | |
141 | ||
e69a4adc | 142 | static __inline__ __be32 addr_bit_set(void *token, int fn_bit) |
1da177e4 | 143 | { |
e69a4adc | 144 | __be32 *addr = token; |
1da177e4 LT |
145 | |
146 | return htonl(1 << ((~fn_bit)&0x1F)) & addr[fn_bit>>5]; | |
147 | } | |
148 | ||
1da177e4 LT |
149 | static __inline__ struct fib6_node * node_alloc(void) |
150 | { | |
151 | struct fib6_node *fn; | |
152 | ||
c3762229 | 153 | fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); |
1da177e4 LT |
154 | |
155 | return fn; | |
156 | } | |
157 | ||
158 | static __inline__ void node_free(struct fib6_node * fn) | |
159 | { | |
160 | kmem_cache_free(fib6_node_kmem, fn); | |
161 | } | |
162 | ||
163 | static __inline__ void rt6_release(struct rt6_info *rt) | |
164 | { | |
165 | if (atomic_dec_and_test(&rt->rt6i_ref)) | |
166 | dst_free(&rt->u.dst); | |
167 | } | |
168 | ||
c71099ac TG |
169 | static struct fib6_table fib6_main_tbl = { |
170 | .tb6_id = RT6_TABLE_MAIN, | |
c71099ac TG |
171 | .tb6_root = { |
172 | .leaf = &ip6_null_entry, | |
173 | .fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO, | |
174 | }, | |
175 | }; | |
176 | ||
177 | #ifdef CONFIG_IPV6_MULTIPLE_TABLES | |
1b43af54 PM |
178 | #define FIB_TABLE_HASHSZ 256 |
179 | #else | |
180 | #define FIB_TABLE_HASHSZ 1 | |
181 | #endif | |
182 | static struct hlist_head fib_table_hash[FIB_TABLE_HASHSZ]; | |
183 | ||
184 | static void fib6_link_table(struct fib6_table *tb) | |
185 | { | |
186 | unsigned int h; | |
187 | ||
375216ad TG |
188 | /* |
189 | * Initialize table lock at a single place to give lockdep a key, | |
190 | * tables aren't visible prior to being linked to the list. | |
191 | */ | |
192 | rwlock_init(&tb->tb6_lock); | |
193 | ||
1b43af54 PM |
194 | h = tb->tb6_id & (FIB_TABLE_HASHSZ - 1); |
195 | ||
196 | /* | |
197 | * No protection necessary, this is the only list mutatation | |
198 | * operation, tables never disappear once they exist. | |
199 | */ | |
200 | hlist_add_head_rcu(&tb->tb6_hlist, &fib_table_hash[h]); | |
201 | } | |
c71099ac | 202 | |
1b43af54 | 203 | #ifdef CONFIG_IPV6_MULTIPLE_TABLES |
101367c2 TG |
204 | static struct fib6_table fib6_local_tbl = { |
205 | .tb6_id = RT6_TABLE_LOCAL, | |
101367c2 TG |
206 | .tb6_root = { |
207 | .leaf = &ip6_null_entry, | |
208 | .fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO, | |
209 | }, | |
210 | }; | |
211 | ||
c71099ac TG |
212 | static struct fib6_table *fib6_alloc_table(u32 id) |
213 | { | |
214 | struct fib6_table *table; | |
215 | ||
216 | table = kzalloc(sizeof(*table), GFP_ATOMIC); | |
217 | if (table != NULL) { | |
218 | table->tb6_id = id; | |
c71099ac TG |
219 | table->tb6_root.leaf = &ip6_null_entry; |
220 | table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; | |
221 | } | |
222 | ||
223 | return table; | |
224 | } | |
225 | ||
c71099ac TG |
226 | struct fib6_table *fib6_new_table(u32 id) |
227 | { | |
228 | struct fib6_table *tb; | |
229 | ||
230 | if (id == 0) | |
231 | id = RT6_TABLE_MAIN; | |
232 | tb = fib6_get_table(id); | |
233 | if (tb) | |
234 | return tb; | |
235 | ||
236 | tb = fib6_alloc_table(id); | |
237 | if (tb != NULL) | |
238 | fib6_link_table(tb); | |
239 | ||
240 | return tb; | |
241 | } | |
242 | ||
243 | struct fib6_table *fib6_get_table(u32 id) | |
244 | { | |
245 | struct fib6_table *tb; | |
246 | struct hlist_node *node; | |
247 | unsigned int h; | |
248 | ||
249 | if (id == 0) | |
250 | id = RT6_TABLE_MAIN; | |
251 | h = id & (FIB_TABLE_HASHSZ - 1); | |
252 | rcu_read_lock(); | |
253 | hlist_for_each_entry_rcu(tb, node, &fib_table_hash[h], tb6_hlist) { | |
254 | if (tb->tb6_id == id) { | |
255 | rcu_read_unlock(); | |
256 | return tb; | |
257 | } | |
258 | } | |
259 | rcu_read_unlock(); | |
260 | ||
261 | return NULL; | |
262 | } | |
263 | ||
c71099ac TG |
264 | static void __init fib6_tables_init(void) |
265 | { | |
266 | fib6_link_table(&fib6_main_tbl); | |
101367c2 | 267 | fib6_link_table(&fib6_local_tbl); |
c71099ac TG |
268 | } |
269 | ||
270 | #else | |
271 | ||
272 | struct fib6_table *fib6_new_table(u32 id) | |
273 | { | |
274 | return fib6_get_table(id); | |
275 | } | |
276 | ||
277 | struct fib6_table *fib6_get_table(u32 id) | |
278 | { | |
279 | return &fib6_main_tbl; | |
280 | } | |
281 | ||
282 | struct dst_entry *fib6_rule_lookup(struct flowi *fl, int flags, | |
283 | pol_lookup_t lookup) | |
284 | { | |
285 | return (struct dst_entry *) lookup(&fib6_main_tbl, fl, flags); | |
286 | } | |
287 | ||
288 | static void __init fib6_tables_init(void) | |
289 | { | |
1b43af54 | 290 | fib6_link_table(&fib6_main_tbl); |
c71099ac TG |
291 | } |
292 | ||
293 | #endif | |
294 | ||
1b43af54 PM |
295 | static int fib6_dump_node(struct fib6_walker_t *w) |
296 | { | |
297 | int res; | |
298 | struct rt6_info *rt; | |
299 | ||
7cc48263 | 300 | for (rt = w->leaf; rt; rt = rt->u.dst.rt6_next) { |
1b43af54 PM |
301 | res = rt6_dump_route(rt, w->args); |
302 | if (res < 0) { | |
303 | /* Frame is full, suspend walking */ | |
304 | w->leaf = rt; | |
305 | return 1; | |
306 | } | |
307 | BUG_TRAP(res!=0); | |
308 | } | |
309 | w->leaf = NULL; | |
310 | return 0; | |
311 | } | |
312 | ||
313 | static void fib6_dump_end(struct netlink_callback *cb) | |
314 | { | |
315 | struct fib6_walker_t *w = (void*)cb->args[2]; | |
316 | ||
317 | if (w) { | |
318 | cb->args[2] = 0; | |
319 | kfree(w); | |
320 | } | |
321 | cb->done = (void*)cb->args[3]; | |
322 | cb->args[1] = 3; | |
323 | } | |
324 | ||
325 | static int fib6_dump_done(struct netlink_callback *cb) | |
326 | { | |
327 | fib6_dump_end(cb); | |
328 | return cb->done ? cb->done(cb) : 0; | |
329 | } | |
330 | ||
331 | static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, | |
332 | struct netlink_callback *cb) | |
333 | { | |
334 | struct fib6_walker_t *w; | |
335 | int res; | |
336 | ||
337 | w = (void *)cb->args[2]; | |
338 | w->root = &table->tb6_root; | |
339 | ||
340 | if (cb->args[4] == 0) { | |
341 | read_lock_bh(&table->tb6_lock); | |
342 | res = fib6_walk(w); | |
343 | read_unlock_bh(&table->tb6_lock); | |
344 | if (res > 0) | |
345 | cb->args[4] = 1; | |
346 | } else { | |
347 | read_lock_bh(&table->tb6_lock); | |
348 | res = fib6_walk_continue(w); | |
349 | read_unlock_bh(&table->tb6_lock); | |
350 | if (res != 0) { | |
351 | if (res < 0) | |
352 | fib6_walker_unlink(w); | |
353 | goto end; | |
354 | } | |
355 | fib6_walker_unlink(w); | |
356 | cb->args[4] = 0; | |
357 | } | |
358 | end: | |
359 | return res; | |
360 | } | |
361 | ||
362 | int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) | |
363 | { | |
364 | unsigned int h, s_h; | |
365 | unsigned int e = 0, s_e; | |
366 | struct rt6_rtnl_dump_arg arg; | |
367 | struct fib6_walker_t *w; | |
368 | struct fib6_table *tb; | |
369 | struct hlist_node *node; | |
370 | int res = 0; | |
371 | ||
372 | s_h = cb->args[0]; | |
373 | s_e = cb->args[1]; | |
374 | ||
375 | w = (void *)cb->args[2]; | |
376 | if (w == NULL) { | |
377 | /* New dump: | |
378 | * | |
379 | * 1. hook callback destructor. | |
380 | */ | |
381 | cb->args[3] = (long)cb->done; | |
382 | cb->done = fib6_dump_done; | |
383 | ||
384 | /* | |
385 | * 2. allocate and initialize walker. | |
386 | */ | |
387 | w = kzalloc(sizeof(*w), GFP_ATOMIC); | |
388 | if (w == NULL) | |
389 | return -ENOMEM; | |
390 | w->func = fib6_dump_node; | |
391 | cb->args[2] = (long)w; | |
392 | } | |
393 | ||
394 | arg.skb = skb; | |
395 | arg.cb = cb; | |
396 | w->args = &arg; | |
397 | ||
398 | for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { | |
399 | e = 0; | |
400 | hlist_for_each_entry(tb, node, &fib_table_hash[h], tb6_hlist) { | |
401 | if (e < s_e) | |
402 | goto next; | |
403 | res = fib6_dump_table(tb, skb, cb); | |
404 | if (res != 0) | |
405 | goto out; | |
406 | next: | |
407 | e++; | |
408 | } | |
409 | } | |
410 | out: | |
411 | cb->args[1] = e; | |
412 | cb->args[0] = h; | |
413 | ||
414 | res = res < 0 ? res : skb->len; | |
415 | if (res <= 0) | |
416 | fib6_dump_end(cb); | |
417 | return res; | |
418 | } | |
1da177e4 LT |
419 | |
420 | /* | |
421 | * Routing Table | |
422 | * | |
423 | * return the appropriate node for a routing tree "add" operation | |
424 | * by either creating and inserting or by returning an existing | |
425 | * node. | |
426 | */ | |
427 | ||
428 | static struct fib6_node * fib6_add_1(struct fib6_node *root, void *addr, | |
429 | int addrlen, int plen, | |
430 | int offset) | |
431 | { | |
432 | struct fib6_node *fn, *in, *ln; | |
433 | struct fib6_node *pn = NULL; | |
434 | struct rt6key *key; | |
435 | int bit; | |
1ab1457c | 436 | __be32 dir = 0; |
1da177e4 LT |
437 | __u32 sernum = fib6_new_sernum(); |
438 | ||
439 | RT6_TRACE("fib6_add_1\n"); | |
440 | ||
441 | /* insert node in tree */ | |
442 | ||
443 | fn = root; | |
444 | ||
445 | do { | |
446 | key = (struct rt6key *)((u8 *)fn->leaf + offset); | |
447 | ||
448 | /* | |
449 | * Prefix match | |
450 | */ | |
451 | if (plen < fn->fn_bit || | |
452 | !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) | |
453 | goto insert_above; | |
1ab1457c | 454 | |
1da177e4 LT |
455 | /* |
456 | * Exact match ? | |
457 | */ | |
1ab1457c | 458 | |
1da177e4 LT |
459 | if (plen == fn->fn_bit) { |
460 | /* clean up an intermediate node */ | |
461 | if ((fn->fn_flags & RTN_RTINFO) == 0) { | |
462 | rt6_release(fn->leaf); | |
463 | fn->leaf = NULL; | |
464 | } | |
1ab1457c | 465 | |
1da177e4 | 466 | fn->fn_sernum = sernum; |
1ab1457c | 467 | |
1da177e4 LT |
468 | return fn; |
469 | } | |
470 | ||
471 | /* | |
472 | * We have more bits to go | |
473 | */ | |
1ab1457c | 474 | |
1da177e4 LT |
475 | /* Try to walk down on tree. */ |
476 | fn->fn_sernum = sernum; | |
477 | dir = addr_bit_set(addr, fn->fn_bit); | |
478 | pn = fn; | |
479 | fn = dir ? fn->right: fn->left; | |
480 | } while (fn); | |
481 | ||
482 | /* | |
483 | * We walked to the bottom of tree. | |
484 | * Create new leaf node without children. | |
485 | */ | |
486 | ||
487 | ln = node_alloc(); | |
488 | ||
489 | if (ln == NULL) | |
490 | return NULL; | |
491 | ln->fn_bit = plen; | |
1ab1457c | 492 | |
1da177e4 LT |
493 | ln->parent = pn; |
494 | ln->fn_sernum = sernum; | |
495 | ||
496 | if (dir) | |
497 | pn->right = ln; | |
498 | else | |
499 | pn->left = ln; | |
500 | ||
501 | return ln; | |
502 | ||
503 | ||
504 | insert_above: | |
505 | /* | |
1ab1457c | 506 | * split since we don't have a common prefix anymore or |
1da177e4 LT |
507 | * we have a less significant route. |
508 | * we've to insert an intermediate node on the list | |
509 | * this new node will point to the one we need to create | |
510 | * and the current | |
511 | */ | |
512 | ||
513 | pn = fn->parent; | |
514 | ||
515 | /* find 1st bit in difference between the 2 addrs. | |
516 | ||
971f359d | 517 | See comment in __ipv6_addr_diff: bit may be an invalid value, |
1da177e4 LT |
518 | but if it is >= plen, the value is ignored in any case. |
519 | */ | |
1ab1457c | 520 | |
971f359d | 521 | bit = __ipv6_addr_diff(addr, &key->addr, addrlen); |
1da177e4 | 522 | |
1ab1457c YH |
523 | /* |
524 | * (intermediate)[in] | |
1da177e4 LT |
525 | * / \ |
526 | * (new leaf node)[ln] (old node)[fn] | |
527 | */ | |
528 | if (plen > bit) { | |
529 | in = node_alloc(); | |
530 | ln = node_alloc(); | |
1ab1457c | 531 | |
1da177e4 LT |
532 | if (in == NULL || ln == NULL) { |
533 | if (in) | |
534 | node_free(in); | |
535 | if (ln) | |
536 | node_free(ln); | |
537 | return NULL; | |
538 | } | |
539 | ||
1ab1457c YH |
540 | /* |
541 | * new intermediate node. | |
1da177e4 LT |
542 | * RTN_RTINFO will |
543 | * be off since that an address that chooses one of | |
544 | * the branches would not match less specific routes | |
545 | * in the other branch | |
546 | */ | |
547 | ||
548 | in->fn_bit = bit; | |
549 | ||
550 | in->parent = pn; | |
551 | in->leaf = fn->leaf; | |
552 | atomic_inc(&in->leaf->rt6i_ref); | |
553 | ||
554 | in->fn_sernum = sernum; | |
555 | ||
556 | /* update parent pointer */ | |
557 | if (dir) | |
558 | pn->right = in; | |
559 | else | |
560 | pn->left = in; | |
561 | ||
562 | ln->fn_bit = plen; | |
563 | ||
564 | ln->parent = in; | |
565 | fn->parent = in; | |
566 | ||
567 | ln->fn_sernum = sernum; | |
568 | ||
569 | if (addr_bit_set(addr, bit)) { | |
570 | in->right = ln; | |
571 | in->left = fn; | |
572 | } else { | |
573 | in->left = ln; | |
574 | in->right = fn; | |
575 | } | |
576 | } else { /* plen <= bit */ | |
577 | ||
1ab1457c | 578 | /* |
1da177e4 LT |
579 | * (new leaf node)[ln] |
580 | * / \ | |
581 | * (old node)[fn] NULL | |
582 | */ | |
583 | ||
584 | ln = node_alloc(); | |
585 | ||
586 | if (ln == NULL) | |
587 | return NULL; | |
588 | ||
589 | ln->fn_bit = plen; | |
590 | ||
591 | ln->parent = pn; | |
592 | ||
593 | ln->fn_sernum = sernum; | |
1ab1457c | 594 | |
1da177e4 LT |
595 | if (dir) |
596 | pn->right = ln; | |
597 | else | |
598 | pn->left = ln; | |
599 | ||
600 | if (addr_bit_set(&key->addr, plen)) | |
601 | ln->right = fn; | |
602 | else | |
603 | ln->left = fn; | |
604 | ||
605 | fn->parent = ln; | |
606 | } | |
607 | return ln; | |
608 | } | |
609 | ||
610 | /* | |
611 | * Insert routing information in a node. | |
612 | */ | |
613 | ||
614 | static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, | |
86872cb5 | 615 | struct nl_info *info) |
1da177e4 LT |
616 | { |
617 | struct rt6_info *iter = NULL; | |
618 | struct rt6_info **ins; | |
619 | ||
620 | ins = &fn->leaf; | |
621 | ||
622 | if (fn->fn_flags&RTN_TL_ROOT && | |
623 | fn->leaf == &ip6_null_entry && | |
624 | !(rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) ){ | |
625 | fn->leaf = rt; | |
7cc48263 | 626 | rt->u.dst.rt6_next = NULL; |
1da177e4 LT |
627 | goto out; |
628 | } | |
629 | ||
7cc48263 | 630 | for (iter = fn->leaf; iter; iter=iter->u.dst.rt6_next) { |
1da177e4 LT |
631 | /* |
632 | * Search for duplicates | |
633 | */ | |
634 | ||
635 | if (iter->rt6i_metric == rt->rt6i_metric) { | |
636 | /* | |
637 | * Same priority level | |
638 | */ | |
639 | ||
640 | if (iter->rt6i_dev == rt->rt6i_dev && | |
641 | iter->rt6i_idev == rt->rt6i_idev && | |
642 | ipv6_addr_equal(&iter->rt6i_gateway, | |
643 | &rt->rt6i_gateway)) { | |
644 | if (!(iter->rt6i_flags&RTF_EXPIRES)) | |
645 | return -EEXIST; | |
646 | iter->rt6i_expires = rt->rt6i_expires; | |
647 | if (!(rt->rt6i_flags&RTF_EXPIRES)) { | |
648 | iter->rt6i_flags &= ~RTF_EXPIRES; | |
649 | iter->rt6i_expires = 0; | |
650 | } | |
651 | return -EEXIST; | |
652 | } | |
653 | } | |
654 | ||
655 | if (iter->rt6i_metric > rt->rt6i_metric) | |
656 | break; | |
657 | ||
7cc48263 | 658 | ins = &iter->u.dst.rt6_next; |
1da177e4 LT |
659 | } |
660 | ||
f11e6659 DM |
661 | /* Reset round-robin state, if necessary */ |
662 | if (ins == &fn->leaf) | |
663 | fn->rr_ptr = NULL; | |
664 | ||
1da177e4 LT |
665 | /* |
666 | * insert node | |
667 | */ | |
668 | ||
669 | out: | |
7cc48263 | 670 | rt->u.dst.rt6_next = iter; |
1da177e4 LT |
671 | *ins = rt; |
672 | rt->rt6i_node = fn; | |
673 | atomic_inc(&rt->rt6i_ref); | |
86872cb5 | 674 | inet6_rt_notify(RTM_NEWROUTE, rt, info); |
1da177e4 LT |
675 | rt6_stats.fib_rt_entries++; |
676 | ||
677 | if ((fn->fn_flags & RTN_RTINFO) == 0) { | |
678 | rt6_stats.fib_route_nodes++; | |
679 | fn->fn_flags |= RTN_RTINFO; | |
680 | } | |
681 | ||
682 | return 0; | |
683 | } | |
684 | ||
685 | static __inline__ void fib6_start_gc(struct rt6_info *rt) | |
686 | { | |
687 | if (ip6_fib_timer.expires == 0 && | |
688 | (rt->rt6i_flags & (RTF_EXPIRES|RTF_CACHE))) | |
689 | mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval); | |
690 | } | |
691 | ||
692 | void fib6_force_start_gc(void) | |
693 | { | |
694 | if (ip6_fib_timer.expires == 0) | |
695 | mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval); | |
696 | } | |
697 | ||
698 | /* | |
699 | * Add routing information to the routing tree. | |
700 | * <destination addr>/<source addr> | |
701 | * with source addr info in sub-trees | |
702 | */ | |
703 | ||
86872cb5 | 704 | int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info) |
1da177e4 | 705 | { |
66729e18 | 706 | struct fib6_node *fn, *pn = NULL; |
1da177e4 LT |
707 | int err = -ENOMEM; |
708 | ||
709 | fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr), | |
710 | rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst)); | |
711 | ||
712 | if (fn == NULL) | |
713 | goto out; | |
714 | ||
66729e18 YH |
715 | pn = fn; |
716 | ||
1da177e4 LT |
717 | #ifdef CONFIG_IPV6_SUBTREES |
718 | if (rt->rt6i_src.plen) { | |
719 | struct fib6_node *sn; | |
720 | ||
721 | if (fn->subtree == NULL) { | |
722 | struct fib6_node *sfn; | |
723 | ||
724 | /* | |
725 | * Create subtree. | |
726 | * | |
727 | * fn[main tree] | |
728 | * | | |
729 | * sfn[subtree root] | |
730 | * \ | |
731 | * sn[new leaf node] | |
732 | */ | |
733 | ||
734 | /* Create subtree root node */ | |
735 | sfn = node_alloc(); | |
736 | if (sfn == NULL) | |
737 | goto st_failure; | |
738 | ||
739 | sfn->leaf = &ip6_null_entry; | |
740 | atomic_inc(&ip6_null_entry.rt6i_ref); | |
741 | sfn->fn_flags = RTN_ROOT; | |
742 | sfn->fn_sernum = fib6_new_sernum(); | |
743 | ||
744 | /* Now add the first leaf node to new subtree */ | |
745 | ||
746 | sn = fib6_add_1(sfn, &rt->rt6i_src.addr, | |
747 | sizeof(struct in6_addr), rt->rt6i_src.plen, | |
748 | offsetof(struct rt6_info, rt6i_src)); | |
749 | ||
750 | if (sn == NULL) { | |
751 | /* If it is failed, discard just allocated | |
752 | root, and then (in st_failure) stale node | |
753 | in main tree. | |
754 | */ | |
755 | node_free(sfn); | |
756 | goto st_failure; | |
757 | } | |
758 | ||
759 | /* Now link new subtree to main tree */ | |
760 | sfn->parent = fn; | |
761 | fn->subtree = sfn; | |
1da177e4 LT |
762 | } else { |
763 | sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr, | |
764 | sizeof(struct in6_addr), rt->rt6i_src.plen, | |
765 | offsetof(struct rt6_info, rt6i_src)); | |
766 | ||
767 | if (sn == NULL) | |
768 | goto st_failure; | |
769 | } | |
770 | ||
66729e18 YH |
771 | if (fn->leaf == NULL) { |
772 | fn->leaf = rt; | |
773 | atomic_inc(&rt->rt6i_ref); | |
774 | } | |
1da177e4 LT |
775 | fn = sn; |
776 | } | |
777 | #endif | |
778 | ||
86872cb5 | 779 | err = fib6_add_rt2node(fn, rt, info); |
1da177e4 LT |
780 | |
781 | if (err == 0) { | |
782 | fib6_start_gc(rt); | |
783 | if (!(rt->rt6i_flags&RTF_CACHE)) | |
2285adc1 | 784 | fib6_prune_clones(pn, rt); |
1da177e4 LT |
785 | } |
786 | ||
787 | out: | |
66729e18 YH |
788 | if (err) { |
789 | #ifdef CONFIG_IPV6_SUBTREES | |
790 | /* | |
791 | * If fib6_add_1 has cleared the old leaf pointer in the | |
792 | * super-tree leaf node we have to find a new one for it. | |
793 | */ | |
794 | if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) { | |
795 | pn->leaf = fib6_find_prefix(pn); | |
796 | #if RT6_DEBUG >= 2 | |
797 | if (!pn->leaf) { | |
798 | BUG_TRAP(pn->leaf != NULL); | |
799 | pn->leaf = &ip6_null_entry; | |
800 | } | |
801 | #endif | |
802 | atomic_inc(&pn->leaf->rt6i_ref); | |
803 | } | |
804 | #endif | |
1da177e4 | 805 | dst_free(&rt->u.dst); |
66729e18 | 806 | } |
1da177e4 LT |
807 | return err; |
808 | ||
809 | #ifdef CONFIG_IPV6_SUBTREES | |
810 | /* Subtree creation failed, probably main tree node | |
811 | is orphan. If it is, shoot it. | |
812 | */ | |
813 | st_failure: | |
814 | if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) | |
815 | fib6_repair_tree(fn); | |
816 | dst_free(&rt->u.dst); | |
817 | return err; | |
818 | #endif | |
819 | } | |
820 | ||
821 | /* | |
822 | * Routing tree lookup | |
823 | * | |
824 | */ | |
825 | ||
826 | struct lookup_args { | |
827 | int offset; /* key offset on rt6_info */ | |
828 | struct in6_addr *addr; /* search key */ | |
829 | }; | |
830 | ||
831 | static struct fib6_node * fib6_lookup_1(struct fib6_node *root, | |
832 | struct lookup_args *args) | |
833 | { | |
834 | struct fib6_node *fn; | |
e69a4adc | 835 | __be32 dir; |
1da177e4 | 836 | |
825e288e YH |
837 | if (unlikely(args->offset == 0)) |
838 | return NULL; | |
839 | ||
1da177e4 LT |
840 | /* |
841 | * Descend on a tree | |
842 | */ | |
843 | ||
844 | fn = root; | |
845 | ||
846 | for (;;) { | |
847 | struct fib6_node *next; | |
848 | ||
849 | dir = addr_bit_set(args->addr, fn->fn_bit); | |
850 | ||
851 | next = dir ? fn->right : fn->left; | |
852 | ||
853 | if (next) { | |
854 | fn = next; | |
855 | continue; | |
856 | } | |
857 | ||
858 | break; | |
859 | } | |
860 | ||
3fc5e044 | 861 | while(fn) { |
7fc33165 | 862 | if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) { |
1da177e4 LT |
863 | struct rt6key *key; |
864 | ||
865 | key = (struct rt6key *) ((u8 *) fn->leaf + | |
866 | args->offset); | |
867 | ||
3fc5e044 YH |
868 | if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { |
869 | #ifdef CONFIG_IPV6_SUBTREES | |
870 | if (fn->subtree) | |
871 | fn = fib6_lookup_1(fn->subtree, args + 1); | |
872 | #endif | |
873 | if (!fn || fn->fn_flags & RTN_RTINFO) | |
874 | return fn; | |
875 | } | |
1da177e4 LT |
876 | } |
877 | ||
3fc5e044 YH |
878 | if (fn->fn_flags & RTN_ROOT) |
879 | break; | |
880 | ||
1da177e4 LT |
881 | fn = fn->parent; |
882 | } | |
883 | ||
884 | return NULL; | |
885 | } | |
886 | ||
887 | struct fib6_node * fib6_lookup(struct fib6_node *root, struct in6_addr *daddr, | |
888 | struct in6_addr *saddr) | |
889 | { | |
1da177e4 | 890 | struct fib6_node *fn; |
825e288e YH |
891 | struct lookup_args args[] = { |
892 | { | |
893 | .offset = offsetof(struct rt6_info, rt6i_dst), | |
894 | .addr = daddr, | |
895 | }, | |
1da177e4 | 896 | #ifdef CONFIG_IPV6_SUBTREES |
825e288e YH |
897 | { |
898 | .offset = offsetof(struct rt6_info, rt6i_src), | |
899 | .addr = saddr, | |
900 | }, | |
1da177e4 | 901 | #endif |
825e288e YH |
902 | { |
903 | .offset = 0, /* sentinel */ | |
904 | } | |
905 | }; | |
1da177e4 | 906 | |
fefc2a6c | 907 | fn = fib6_lookup_1(root, daddr ? args : args + 1); |
1da177e4 LT |
908 | |
909 | if (fn == NULL || fn->fn_flags & RTN_TL_ROOT) | |
910 | fn = root; | |
911 | ||
912 | return fn; | |
913 | } | |
914 | ||
915 | /* | |
916 | * Get node with specified destination prefix (and source prefix, | |
917 | * if subtrees are used) | |
918 | */ | |
919 | ||
920 | ||
921 | static struct fib6_node * fib6_locate_1(struct fib6_node *root, | |
922 | struct in6_addr *addr, | |
923 | int plen, int offset) | |
924 | { | |
925 | struct fib6_node *fn; | |
926 | ||
927 | for (fn = root; fn ; ) { | |
928 | struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset); | |
929 | ||
930 | /* | |
931 | * Prefix match | |
932 | */ | |
933 | if (plen < fn->fn_bit || | |
934 | !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) | |
935 | return NULL; | |
936 | ||
937 | if (plen == fn->fn_bit) | |
938 | return fn; | |
939 | ||
940 | /* | |
941 | * We have more bits to go | |
942 | */ | |
943 | if (addr_bit_set(addr, fn->fn_bit)) | |
944 | fn = fn->right; | |
945 | else | |
946 | fn = fn->left; | |
947 | } | |
948 | return NULL; | |
949 | } | |
950 | ||
951 | struct fib6_node * fib6_locate(struct fib6_node *root, | |
952 | struct in6_addr *daddr, int dst_len, | |
953 | struct in6_addr *saddr, int src_len) | |
954 | { | |
955 | struct fib6_node *fn; | |
956 | ||
957 | fn = fib6_locate_1(root, daddr, dst_len, | |
958 | offsetof(struct rt6_info, rt6i_dst)); | |
959 | ||
960 | #ifdef CONFIG_IPV6_SUBTREES | |
961 | if (src_len) { | |
962 | BUG_TRAP(saddr!=NULL); | |
3fc5e044 YH |
963 | if (fn && fn->subtree) |
964 | fn = fib6_locate_1(fn->subtree, saddr, src_len, | |
1da177e4 LT |
965 | offsetof(struct rt6_info, rt6i_src)); |
966 | } | |
967 | #endif | |
968 | ||
969 | if (fn && fn->fn_flags&RTN_RTINFO) | |
970 | return fn; | |
971 | ||
972 | return NULL; | |
973 | } | |
974 | ||
975 | ||
976 | /* | |
977 | * Deletion | |
978 | * | |
979 | */ | |
980 | ||
981 | static struct rt6_info * fib6_find_prefix(struct fib6_node *fn) | |
982 | { | |
983 | if (fn->fn_flags&RTN_ROOT) | |
984 | return &ip6_null_entry; | |
985 | ||
986 | while(fn) { | |
987 | if(fn->left) | |
988 | return fn->left->leaf; | |
989 | ||
990 | if(fn->right) | |
991 | return fn->right->leaf; | |
992 | ||
7fc33165 | 993 | fn = FIB6_SUBTREE(fn); |
1da177e4 LT |
994 | } |
995 | return NULL; | |
996 | } | |
997 | ||
998 | /* | |
999 | * Called to trim the tree of intermediate nodes when possible. "fn" | |
1000 | * is the node we want to try and remove. | |
1001 | */ | |
1002 | ||
1003 | static struct fib6_node * fib6_repair_tree(struct fib6_node *fn) | |
1004 | { | |
1005 | int children; | |
1006 | int nstate; | |
1007 | struct fib6_node *child, *pn; | |
1008 | struct fib6_walker_t *w; | |
1009 | int iter = 0; | |
1010 | ||
1011 | for (;;) { | |
1012 | RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); | |
1013 | iter++; | |
1014 | ||
1015 | BUG_TRAP(!(fn->fn_flags&RTN_RTINFO)); | |
1016 | BUG_TRAP(!(fn->fn_flags&RTN_TL_ROOT)); | |
1017 | BUG_TRAP(fn->leaf==NULL); | |
1018 | ||
1019 | children = 0; | |
1020 | child = NULL; | |
1021 | if (fn->right) child = fn->right, children |= 1; | |
1022 | if (fn->left) child = fn->left, children |= 2; | |
1023 | ||
7fc33165 | 1024 | if (children == 3 || FIB6_SUBTREE(fn) |
1da177e4 LT |
1025 | #ifdef CONFIG_IPV6_SUBTREES |
1026 | /* Subtree root (i.e. fn) may have one child */ | |
1027 | || (children && fn->fn_flags&RTN_ROOT) | |
1028 | #endif | |
1029 | ) { | |
1030 | fn->leaf = fib6_find_prefix(fn); | |
1031 | #if RT6_DEBUG >= 2 | |
1032 | if (fn->leaf==NULL) { | |
1033 | BUG_TRAP(fn->leaf); | |
1034 | fn->leaf = &ip6_null_entry; | |
1035 | } | |
1036 | #endif | |
1037 | atomic_inc(&fn->leaf->rt6i_ref); | |
1038 | return fn->parent; | |
1039 | } | |
1040 | ||
1041 | pn = fn->parent; | |
1042 | #ifdef CONFIG_IPV6_SUBTREES | |
7fc33165 | 1043 | if (FIB6_SUBTREE(pn) == fn) { |
1da177e4 | 1044 | BUG_TRAP(fn->fn_flags&RTN_ROOT); |
7fc33165 | 1045 | FIB6_SUBTREE(pn) = NULL; |
1da177e4 LT |
1046 | nstate = FWS_L; |
1047 | } else { | |
1048 | BUG_TRAP(!(fn->fn_flags&RTN_ROOT)); | |
1049 | #endif | |
1050 | if (pn->right == fn) pn->right = child; | |
1051 | else if (pn->left == fn) pn->left = child; | |
1052 | #if RT6_DEBUG >= 2 | |
1053 | else BUG_TRAP(0); | |
1054 | #endif | |
1055 | if (child) | |
1056 | child->parent = pn; | |
1057 | nstate = FWS_R; | |
1058 | #ifdef CONFIG_IPV6_SUBTREES | |
1059 | } | |
1060 | #endif | |
1061 | ||
1062 | read_lock(&fib6_walker_lock); | |
1063 | FOR_WALKERS(w) { | |
1064 | if (child == NULL) { | |
1065 | if (w->root == fn) { | |
1066 | w->root = w->node = NULL; | |
1067 | RT6_TRACE("W %p adjusted by delroot 1\n", w); | |
1068 | } else if (w->node == fn) { | |
1069 | RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); | |
1070 | w->node = pn; | |
1071 | w->state = nstate; | |
1072 | } | |
1073 | } else { | |
1074 | if (w->root == fn) { | |
1075 | w->root = child; | |
1076 | RT6_TRACE("W %p adjusted by delroot 2\n", w); | |
1077 | } | |
1078 | if (w->node == fn) { | |
1079 | w->node = child; | |
1080 | if (children&2) { | |
1081 | RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); | |
1082 | w->state = w->state>=FWS_R ? FWS_U : FWS_INIT; | |
1083 | } else { | |
1084 | RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); | |
1085 | w->state = w->state>=FWS_C ? FWS_U : FWS_INIT; | |
1086 | } | |
1087 | } | |
1088 | } | |
1089 | } | |
1090 | read_unlock(&fib6_walker_lock); | |
1091 | ||
1092 | node_free(fn); | |
7fc33165 | 1093 | if (pn->fn_flags&RTN_RTINFO || FIB6_SUBTREE(pn)) |
1da177e4 LT |
1094 | return pn; |
1095 | ||
1096 | rt6_release(pn->leaf); | |
1097 | pn->leaf = NULL; | |
1098 | fn = pn; | |
1099 | } | |
1100 | } | |
1101 | ||
1102 | static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, | |
86872cb5 | 1103 | struct nl_info *info) |
1da177e4 LT |
1104 | { |
1105 | struct fib6_walker_t *w; | |
1106 | struct rt6_info *rt = *rtp; | |
1107 | ||
1108 | RT6_TRACE("fib6_del_route\n"); | |
1109 | ||
1110 | /* Unlink it */ | |
7cc48263 | 1111 | *rtp = rt->u.dst.rt6_next; |
1da177e4 LT |
1112 | rt->rt6i_node = NULL; |
1113 | rt6_stats.fib_rt_entries--; | |
1114 | rt6_stats.fib_discarded_routes++; | |
1115 | ||
f11e6659 DM |
1116 | /* Reset round-robin state, if necessary */ |
1117 | if (fn->rr_ptr == rt) | |
1118 | fn->rr_ptr = NULL; | |
1119 | ||
1da177e4 LT |
1120 | /* Adjust walkers */ |
1121 | read_lock(&fib6_walker_lock); | |
1122 | FOR_WALKERS(w) { | |
1123 | if (w->state == FWS_C && w->leaf == rt) { | |
1124 | RT6_TRACE("walker %p adjusted by delroute\n", w); | |
7cc48263 | 1125 | w->leaf = rt->u.dst.rt6_next; |
1da177e4 LT |
1126 | if (w->leaf == NULL) |
1127 | w->state = FWS_U; | |
1128 | } | |
1129 | } | |
1130 | read_unlock(&fib6_walker_lock); | |
1131 | ||
7cc48263 | 1132 | rt->u.dst.rt6_next = NULL; |
1da177e4 LT |
1133 | |
1134 | if (fn->leaf == NULL && fn->fn_flags&RTN_TL_ROOT) | |
1135 | fn->leaf = &ip6_null_entry; | |
1136 | ||
1137 | /* If it was last route, expunge its radix tree node */ | |
1138 | if (fn->leaf == NULL) { | |
1139 | fn->fn_flags &= ~RTN_RTINFO; | |
1140 | rt6_stats.fib_route_nodes--; | |
1141 | fn = fib6_repair_tree(fn); | |
1142 | } | |
1143 | ||
1144 | if (atomic_read(&rt->rt6i_ref) != 1) { | |
1145 | /* This route is used as dummy address holder in some split | |
1146 | * nodes. It is not leaked, but it still holds other resources, | |
1147 | * which must be released in time. So, scan ascendant nodes | |
1148 | * and replace dummy references to this route with references | |
1149 | * to still alive ones. | |
1150 | */ | |
1151 | while (fn) { | |
1152 | if (!(fn->fn_flags&RTN_RTINFO) && fn->leaf == rt) { | |
1153 | fn->leaf = fib6_find_prefix(fn); | |
1154 | atomic_inc(&fn->leaf->rt6i_ref); | |
1155 | rt6_release(rt); | |
1156 | } | |
1157 | fn = fn->parent; | |
1158 | } | |
1159 | /* No more references are possible at this point. */ | |
1160 | if (atomic_read(&rt->rt6i_ref) != 1) BUG(); | |
1161 | } | |
1162 | ||
86872cb5 | 1163 | inet6_rt_notify(RTM_DELROUTE, rt, info); |
1da177e4 LT |
1164 | rt6_release(rt); |
1165 | } | |
1166 | ||
86872cb5 | 1167 | int fib6_del(struct rt6_info *rt, struct nl_info *info) |
1da177e4 LT |
1168 | { |
1169 | struct fib6_node *fn = rt->rt6i_node; | |
1170 | struct rt6_info **rtp; | |
1171 | ||
1172 | #if RT6_DEBUG >= 2 | |
1173 | if (rt->u.dst.obsolete>0) { | |
1174 | BUG_TRAP(fn==NULL); | |
1175 | return -ENOENT; | |
1176 | } | |
1177 | #endif | |
1178 | if (fn == NULL || rt == &ip6_null_entry) | |
1179 | return -ENOENT; | |
1180 | ||
1181 | BUG_TRAP(fn->fn_flags&RTN_RTINFO); | |
1182 | ||
150730d5 YH |
1183 | if (!(rt->rt6i_flags&RTF_CACHE)) { |
1184 | struct fib6_node *pn = fn; | |
1185 | #ifdef CONFIG_IPV6_SUBTREES | |
1186 | /* clones of this route might be in another subtree */ | |
1187 | if (rt->rt6i_src.plen) { | |
1188 | while (!(pn->fn_flags&RTN_ROOT)) | |
1189 | pn = pn->parent; | |
1190 | pn = pn->parent; | |
1191 | } | |
1192 | #endif | |
1193 | fib6_prune_clones(pn, rt); | |
1194 | } | |
1da177e4 LT |
1195 | |
1196 | /* | |
1197 | * Walk the leaf entries looking for ourself | |
1198 | */ | |
1199 | ||
7cc48263 | 1200 | for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->u.dst.rt6_next) { |
1da177e4 | 1201 | if (*rtp == rt) { |
86872cb5 | 1202 | fib6_del_route(fn, rtp, info); |
1da177e4 LT |
1203 | return 0; |
1204 | } | |
1205 | } | |
1206 | return -ENOENT; | |
1207 | } | |
1208 | ||
1209 | /* | |
1210 | * Tree traversal function. | |
1211 | * | |
1212 | * Certainly, it is not interrupt safe. | |
1213 | * However, it is internally reenterable wrt itself and fib6_add/fib6_del. | |
1214 | * It means, that we can modify tree during walking | |
1215 | * and use this function for garbage collection, clone pruning, | |
1ab1457c | 1216 | * cleaning tree when a device goes down etc. etc. |
1da177e4 LT |
1217 | * |
1218 | * It guarantees that every node will be traversed, | |
1219 | * and that it will be traversed only once. | |
1220 | * | |
1221 | * Callback function w->func may return: | |
1222 | * 0 -> continue walking. | |
1223 | * positive value -> walking is suspended (used by tree dumps, | |
1224 | * and probably by gc, if it will be split to several slices) | |
1225 | * negative value -> terminate walking. | |
1226 | * | |
1227 | * The function itself returns: | |
1228 | * 0 -> walk is complete. | |
1229 | * >0 -> walk is incomplete (i.e. suspended) | |
1230 | * <0 -> walk is terminated by an error. | |
1231 | */ | |
1232 | ||
90d41122 | 1233 | static int fib6_walk_continue(struct fib6_walker_t *w) |
1da177e4 LT |
1234 | { |
1235 | struct fib6_node *fn, *pn; | |
1236 | ||
1237 | for (;;) { | |
1238 | fn = w->node; | |
1239 | if (fn == NULL) | |
1240 | return 0; | |
1241 | ||
1242 | if (w->prune && fn != w->root && | |
1243 | fn->fn_flags&RTN_RTINFO && w->state < FWS_C) { | |
1244 | w->state = FWS_C; | |
1245 | w->leaf = fn->leaf; | |
1246 | } | |
1247 | switch (w->state) { | |
1248 | #ifdef CONFIG_IPV6_SUBTREES | |
1249 | case FWS_S: | |
7fc33165 YH |
1250 | if (FIB6_SUBTREE(fn)) { |
1251 | w->node = FIB6_SUBTREE(fn); | |
1da177e4 LT |
1252 | continue; |
1253 | } | |
1254 | w->state = FWS_L; | |
1ab1457c | 1255 | #endif |
1da177e4 LT |
1256 | case FWS_L: |
1257 | if (fn->left) { | |
1258 | w->node = fn->left; | |
1259 | w->state = FWS_INIT; | |
1260 | continue; | |
1261 | } | |
1262 | w->state = FWS_R; | |
1263 | case FWS_R: | |
1264 | if (fn->right) { | |
1265 | w->node = fn->right; | |
1266 | w->state = FWS_INIT; | |
1267 | continue; | |
1268 | } | |
1269 | w->state = FWS_C; | |
1270 | w->leaf = fn->leaf; | |
1271 | case FWS_C: | |
1272 | if (w->leaf && fn->fn_flags&RTN_RTINFO) { | |
1273 | int err = w->func(w); | |
1274 | if (err) | |
1275 | return err; | |
1276 | continue; | |
1277 | } | |
1278 | w->state = FWS_U; | |
1279 | case FWS_U: | |
1280 | if (fn == w->root) | |
1281 | return 0; | |
1282 | pn = fn->parent; | |
1283 | w->node = pn; | |
1284 | #ifdef CONFIG_IPV6_SUBTREES | |
7fc33165 | 1285 | if (FIB6_SUBTREE(pn) == fn) { |
1da177e4 LT |
1286 | BUG_TRAP(fn->fn_flags&RTN_ROOT); |
1287 | w->state = FWS_L; | |
1288 | continue; | |
1289 | } | |
1290 | #endif | |
1291 | if (pn->left == fn) { | |
1292 | w->state = FWS_R; | |
1293 | continue; | |
1294 | } | |
1295 | if (pn->right == fn) { | |
1296 | w->state = FWS_C; | |
1297 | w->leaf = w->node->leaf; | |
1298 | continue; | |
1299 | } | |
1300 | #if RT6_DEBUG >= 2 | |
1301 | BUG_TRAP(0); | |
1302 | #endif | |
1303 | } | |
1304 | } | |
1305 | } | |
1306 | ||
90d41122 | 1307 | static int fib6_walk(struct fib6_walker_t *w) |
1da177e4 LT |
1308 | { |
1309 | int res; | |
1310 | ||
1311 | w->state = FWS_INIT; | |
1312 | w->node = w->root; | |
1313 | ||
1314 | fib6_walker_link(w); | |
1315 | res = fib6_walk_continue(w); | |
1316 | if (res <= 0) | |
1317 | fib6_walker_unlink(w); | |
1318 | return res; | |
1319 | } | |
1320 | ||
1321 | static int fib6_clean_node(struct fib6_walker_t *w) | |
1322 | { | |
1323 | int res; | |
1324 | struct rt6_info *rt; | |
1325 | struct fib6_cleaner_t *c = (struct fib6_cleaner_t*)w; | |
1326 | ||
7cc48263 | 1327 | for (rt = w->leaf; rt; rt = rt->u.dst.rt6_next) { |
1da177e4 LT |
1328 | res = c->func(rt, c->arg); |
1329 | if (res < 0) { | |
1330 | w->leaf = rt; | |
86872cb5 | 1331 | res = fib6_del(rt, NULL); |
1da177e4 LT |
1332 | if (res) { |
1333 | #if RT6_DEBUG >= 2 | |
1334 | printk(KERN_DEBUG "fib6_clean_node: del failed: rt=%p@%p err=%d\n", rt, rt->rt6i_node, res); | |
1335 | #endif | |
1336 | continue; | |
1337 | } | |
1338 | return 0; | |
1339 | } | |
1340 | BUG_TRAP(res==0); | |
1341 | } | |
1342 | w->leaf = rt; | |
1343 | return 0; | |
1344 | } | |
1345 | ||
1346 | /* | |
1347 | * Convenient frontend to tree walker. | |
1ab1457c | 1348 | * |
1da177e4 LT |
1349 | * func is called on each route. |
1350 | * It may return -1 -> delete this route. | |
1351 | * 0 -> continue walking | |
1352 | * | |
1353 | * prune==1 -> only immediate children of node (certainly, | |
1354 | * ignoring pure split nodes) will be scanned. | |
1355 | */ | |
1356 | ||
8ce11e6a AB |
1357 | static void fib6_clean_tree(struct fib6_node *root, |
1358 | int (*func)(struct rt6_info *, void *arg), | |
1359 | int prune, void *arg) | |
1da177e4 LT |
1360 | { |
1361 | struct fib6_cleaner_t c; | |
1362 | ||
1363 | c.w.root = root; | |
1364 | c.w.func = fib6_clean_node; | |
1365 | c.w.prune = prune; | |
1366 | c.func = func; | |
1367 | c.arg = arg; | |
1368 | ||
1369 | fib6_walk(&c.w); | |
1370 | } | |
1371 | ||
c71099ac TG |
1372 | void fib6_clean_all(int (*func)(struct rt6_info *, void *arg), |
1373 | int prune, void *arg) | |
1374 | { | |
c71099ac | 1375 | struct fib6_table *table; |
1b43af54 PM |
1376 | struct hlist_node *node; |
1377 | unsigned int h; | |
c71099ac | 1378 | |
1b43af54 PM |
1379 | rcu_read_lock(); |
1380 | for (h = 0; h < FIB_TABLE_HASHSZ; h++) { | |
1381 | hlist_for_each_entry_rcu(table, node, &fib_table_hash[h], | |
1382 | tb6_hlist) { | |
c71099ac TG |
1383 | write_lock_bh(&table->tb6_lock); |
1384 | fib6_clean_tree(&table->tb6_root, func, prune, arg); | |
1385 | write_unlock_bh(&table->tb6_lock); | |
1386 | } | |
1387 | } | |
1b43af54 | 1388 | rcu_read_unlock(); |
c71099ac TG |
1389 | } |
1390 | ||
1da177e4 LT |
1391 | static int fib6_prune_clone(struct rt6_info *rt, void *arg) |
1392 | { | |
1393 | if (rt->rt6i_flags & RTF_CACHE) { | |
1394 | RT6_TRACE("pruning clone %p\n", rt); | |
1395 | return -1; | |
1396 | } | |
1397 | ||
1398 | return 0; | |
1399 | } | |
1400 | ||
1401 | static void fib6_prune_clones(struct fib6_node *fn, struct rt6_info *rt) | |
1402 | { | |
1403 | fib6_clean_tree(fn, fib6_prune_clone, 1, rt); | |
1404 | } | |
1405 | ||
1406 | /* | |
1407 | * Garbage collection | |
1408 | */ | |
1409 | ||
1410 | static struct fib6_gc_args | |
1411 | { | |
1412 | int timeout; | |
1413 | int more; | |
1414 | } gc_args; | |
1415 | ||
1416 | static int fib6_age(struct rt6_info *rt, void *arg) | |
1417 | { | |
1418 | unsigned long now = jiffies; | |
1419 | ||
1420 | /* | |
1421 | * check addrconf expiration here. | |
1422 | * Routes are expired even if they are in use. | |
1423 | * | |
1424 | * Also age clones. Note, that clones are aged out | |
1425 | * only if they are not in use now. | |
1426 | */ | |
1427 | ||
1428 | if (rt->rt6i_flags&RTF_EXPIRES && rt->rt6i_expires) { | |
1429 | if (time_after(now, rt->rt6i_expires)) { | |
1430 | RT6_TRACE("expiring %p\n", rt); | |
1da177e4 LT |
1431 | return -1; |
1432 | } | |
1433 | gc_args.more++; | |
1434 | } else if (rt->rt6i_flags & RTF_CACHE) { | |
1435 | if (atomic_read(&rt->u.dst.__refcnt) == 0 && | |
1436 | time_after_eq(now, rt->u.dst.lastuse + gc_args.timeout)) { | |
1437 | RT6_TRACE("aging clone %p\n", rt); | |
1438 | return -1; | |
1439 | } else if ((rt->rt6i_flags & RTF_GATEWAY) && | |
1440 | (!(rt->rt6i_nexthop->flags & NTF_ROUTER))) { | |
1441 | RT6_TRACE("purging route %p via non-router but gateway\n", | |
1442 | rt); | |
1443 | return -1; | |
1444 | } | |
1445 | gc_args.more++; | |
1446 | } | |
1447 | ||
1448 | return 0; | |
1449 | } | |
1450 | ||
1451 | static DEFINE_SPINLOCK(fib6_gc_lock); | |
1452 | ||
1453 | void fib6_run_gc(unsigned long dummy) | |
1454 | { | |
1455 | if (dummy != ~0UL) { | |
1456 | spin_lock_bh(&fib6_gc_lock); | |
1457 | gc_args.timeout = dummy ? (int)dummy : ip6_rt_gc_interval; | |
1458 | } else { | |
1459 | local_bh_disable(); | |
1460 | if (!spin_trylock(&fib6_gc_lock)) { | |
1461 | mod_timer(&ip6_fib_timer, jiffies + HZ); | |
1462 | local_bh_enable(); | |
1463 | return; | |
1464 | } | |
1465 | gc_args.timeout = ip6_rt_gc_interval; | |
1466 | } | |
1467 | gc_args.more = 0; | |
1468 | ||
1da177e4 | 1469 | ndisc_dst_gc(&gc_args.more); |
c71099ac | 1470 | fib6_clean_all(fib6_age, 0, NULL); |
1da177e4 LT |
1471 | |
1472 | if (gc_args.more) | |
1473 | mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval); | |
1474 | else { | |
1475 | del_timer(&ip6_fib_timer); | |
1476 | ip6_fib_timer.expires = 0; | |
1477 | } | |
1478 | spin_unlock_bh(&fib6_gc_lock); | |
1479 | } | |
1480 | ||
1481 | void __init fib6_init(void) | |
1482 | { | |
1483 | fib6_node_kmem = kmem_cache_create("fib6_nodes", | |
1484 | sizeof(struct fib6_node), | |
e5d679f3 | 1485 | 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, |
1da177e4 | 1486 | NULL, NULL); |
c71099ac TG |
1487 | |
1488 | fib6_tables_init(); | |
1da177e4 LT |
1489 | } |
1490 | ||
1491 | void fib6_gc_cleanup(void) | |
1492 | { | |
1493 | del_timer(&ip6_fib_timer); | |
1494 | kmem_cache_destroy(fib6_node_kmem); | |
1495 | } |