Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Linux INET6 implementation | |
3 | * Forwarding Information Database | |
4 | * | |
5 | * Authors: | |
6 | * Pedro Roque <roque@di.fc.ul.pt> | |
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. | |
21 | */ | |
22 | #include <linux/config.h> | |
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> | |
30 | ||
31 | #ifdef CONFIG_PROC_FS | |
32 | #include <linux/proc_fs.h> | |
33 | #endif | |
34 | ||
35 | #include <net/ipv6.h> | |
36 | #include <net/ndisc.h> | |
37 | #include <net/addrconf.h> | |
38 | ||
39 | #include <net/ip6_fib.h> | |
40 | #include <net/ip6_route.h> | |
41 | ||
42 | #define RT6_DEBUG 2 | |
43 | ||
44 | #if RT6_DEBUG >= 3 | |
45 | #define RT6_TRACE(x...) printk(KERN_DEBUG x) | |
46 | #else | |
47 | #define RT6_TRACE(x...) do { ; } while (0) | |
48 | #endif | |
49 | ||
50 | struct rt6_statistics rt6_stats; | |
51 | ||
ba89966c | 52 | static kmem_cache_t * fib6_node_kmem __read_mostly; |
1da177e4 LT |
53 | |
54 | enum fib_walk_state_t | |
55 | { | |
56 | #ifdef CONFIG_IPV6_SUBTREES | |
57 | FWS_S, | |
58 | #endif | |
59 | FWS_L, | |
60 | FWS_R, | |
61 | FWS_C, | |
62 | FWS_U | |
63 | }; | |
64 | ||
65 | struct fib6_cleaner_t | |
66 | { | |
67 | struct fib6_walker_t w; | |
68 | int (*func)(struct rt6_info *, void *arg); | |
69 | void *arg; | |
70 | }; | |
71 | ||
72 | DEFINE_RWLOCK(fib6_walker_lock); | |
73 | ||
74 | ||
75 | #ifdef CONFIG_IPV6_SUBTREES | |
76 | #define FWS_INIT FWS_S | |
77 | #define SUBTREE(fn) ((fn)->subtree) | |
78 | #else | |
79 | #define FWS_INIT FWS_L | |
80 | #define SUBTREE(fn) NULL | |
81 | #endif | |
82 | ||
83 | static void fib6_prune_clones(struct fib6_node *fn, struct rt6_info *rt); | |
84 | static struct fib6_node * fib6_repair_tree(struct fib6_node *fn); | |
85 | ||
86 | /* | |
87 | * A routing update causes an increase of the serial number on the | |
88 | * affected subtree. This allows for cached routes to be asynchronously | |
89 | * tested when modifications are made to the destination cache as a | |
90 | * result of redirects, path MTU changes, etc. | |
91 | */ | |
92 | ||
93 | static __u32 rt_sernum; | |
94 | ||
8d06afab | 95 | static DEFINE_TIMER(ip6_fib_timer, fib6_run_gc, 0, 0); |
1da177e4 LT |
96 | |
97 | struct fib6_walker_t fib6_walker_list = { | |
98 | .prev = &fib6_walker_list, | |
99 | .next = &fib6_walker_list, | |
100 | }; | |
101 | ||
102 | #define FOR_WALKERS(w) for ((w)=fib6_walker_list.next; (w) != &fib6_walker_list; (w)=(w)->next) | |
103 | ||
104 | static __inline__ u32 fib6_new_sernum(void) | |
105 | { | |
106 | u32 n = ++rt_sernum; | |
107 | if ((__s32)n <= 0) | |
108 | rt_sernum = n = 1; | |
109 | return n; | |
110 | } | |
111 | ||
112 | /* | |
113 | * Auxiliary address test functions for the radix tree. | |
114 | * | |
115 | * These assume a 32bit processor (although it will work on | |
116 | * 64bit processors) | |
117 | */ | |
118 | ||
119 | /* | |
120 | * test bit | |
121 | */ | |
122 | ||
123 | static __inline__ int addr_bit_set(void *token, int fn_bit) | |
124 | { | |
125 | __u32 *addr = token; | |
126 | ||
127 | return htonl(1 << ((~fn_bit)&0x1F)) & addr[fn_bit>>5]; | |
128 | } | |
129 | ||
1da177e4 LT |
130 | static __inline__ struct fib6_node * node_alloc(void) |
131 | { | |
132 | struct fib6_node *fn; | |
133 | ||
134 | if ((fn = kmem_cache_alloc(fib6_node_kmem, SLAB_ATOMIC)) != NULL) | |
135 | memset(fn, 0, sizeof(struct fib6_node)); | |
136 | ||
137 | return fn; | |
138 | } | |
139 | ||
140 | static __inline__ void node_free(struct fib6_node * fn) | |
141 | { | |
142 | kmem_cache_free(fib6_node_kmem, fn); | |
143 | } | |
144 | ||
145 | static __inline__ void rt6_release(struct rt6_info *rt) | |
146 | { | |
147 | if (atomic_dec_and_test(&rt->rt6i_ref)) | |
148 | dst_free(&rt->u.dst); | |
149 | } | |
150 | ||
151 | ||
152 | /* | |
153 | * Routing Table | |
154 | * | |
155 | * return the appropriate node for a routing tree "add" operation | |
156 | * by either creating and inserting or by returning an existing | |
157 | * node. | |
158 | */ | |
159 | ||
160 | static struct fib6_node * fib6_add_1(struct fib6_node *root, void *addr, | |
161 | int addrlen, int plen, | |
162 | int offset) | |
163 | { | |
164 | struct fib6_node *fn, *in, *ln; | |
165 | struct fib6_node *pn = NULL; | |
166 | struct rt6key *key; | |
167 | int bit; | |
168 | int dir = 0; | |
169 | __u32 sernum = fib6_new_sernum(); | |
170 | ||
171 | RT6_TRACE("fib6_add_1\n"); | |
172 | ||
173 | /* insert node in tree */ | |
174 | ||
175 | fn = root; | |
176 | ||
177 | do { | |
178 | key = (struct rt6key *)((u8 *)fn->leaf + offset); | |
179 | ||
180 | /* | |
181 | * Prefix match | |
182 | */ | |
183 | if (plen < fn->fn_bit || | |
184 | !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) | |
185 | goto insert_above; | |
186 | ||
187 | /* | |
188 | * Exact match ? | |
189 | */ | |
190 | ||
191 | if (plen == fn->fn_bit) { | |
192 | /* clean up an intermediate node */ | |
193 | if ((fn->fn_flags & RTN_RTINFO) == 0) { | |
194 | rt6_release(fn->leaf); | |
195 | fn->leaf = NULL; | |
196 | } | |
197 | ||
198 | fn->fn_sernum = sernum; | |
199 | ||
200 | return fn; | |
201 | } | |
202 | ||
203 | /* | |
204 | * We have more bits to go | |
205 | */ | |
206 | ||
207 | /* Try to walk down on tree. */ | |
208 | fn->fn_sernum = sernum; | |
209 | dir = addr_bit_set(addr, fn->fn_bit); | |
210 | pn = fn; | |
211 | fn = dir ? fn->right: fn->left; | |
212 | } while (fn); | |
213 | ||
214 | /* | |
215 | * We walked to the bottom of tree. | |
216 | * Create new leaf node without children. | |
217 | */ | |
218 | ||
219 | ln = node_alloc(); | |
220 | ||
221 | if (ln == NULL) | |
222 | return NULL; | |
223 | ln->fn_bit = plen; | |
224 | ||
225 | ln->parent = pn; | |
226 | ln->fn_sernum = sernum; | |
227 | ||
228 | if (dir) | |
229 | pn->right = ln; | |
230 | else | |
231 | pn->left = ln; | |
232 | ||
233 | return ln; | |
234 | ||
235 | ||
236 | insert_above: | |
237 | /* | |
238 | * split since we don't have a common prefix anymore or | |
239 | * we have a less significant route. | |
240 | * we've to insert an intermediate node on the list | |
241 | * this new node will point to the one we need to create | |
242 | * and the current | |
243 | */ | |
244 | ||
245 | pn = fn->parent; | |
246 | ||
247 | /* find 1st bit in difference between the 2 addrs. | |
248 | ||
971f359d | 249 | See comment in __ipv6_addr_diff: bit may be an invalid value, |
1da177e4 LT |
250 | but if it is >= plen, the value is ignored in any case. |
251 | */ | |
252 | ||
971f359d | 253 | bit = __ipv6_addr_diff(addr, &key->addr, addrlen); |
1da177e4 LT |
254 | |
255 | /* | |
256 | * (intermediate)[in] | |
257 | * / \ | |
258 | * (new leaf node)[ln] (old node)[fn] | |
259 | */ | |
260 | if (plen > bit) { | |
261 | in = node_alloc(); | |
262 | ln = node_alloc(); | |
263 | ||
264 | if (in == NULL || ln == NULL) { | |
265 | if (in) | |
266 | node_free(in); | |
267 | if (ln) | |
268 | node_free(ln); | |
269 | return NULL; | |
270 | } | |
271 | ||
272 | /* | |
273 | * new intermediate node. | |
274 | * RTN_RTINFO will | |
275 | * be off since that an address that chooses one of | |
276 | * the branches would not match less specific routes | |
277 | * in the other branch | |
278 | */ | |
279 | ||
280 | in->fn_bit = bit; | |
281 | ||
282 | in->parent = pn; | |
283 | in->leaf = fn->leaf; | |
284 | atomic_inc(&in->leaf->rt6i_ref); | |
285 | ||
286 | in->fn_sernum = sernum; | |
287 | ||
288 | /* update parent pointer */ | |
289 | if (dir) | |
290 | pn->right = in; | |
291 | else | |
292 | pn->left = in; | |
293 | ||
294 | ln->fn_bit = plen; | |
295 | ||
296 | ln->parent = in; | |
297 | fn->parent = in; | |
298 | ||
299 | ln->fn_sernum = sernum; | |
300 | ||
301 | if (addr_bit_set(addr, bit)) { | |
302 | in->right = ln; | |
303 | in->left = fn; | |
304 | } else { | |
305 | in->left = ln; | |
306 | in->right = fn; | |
307 | } | |
308 | } else { /* plen <= bit */ | |
309 | ||
310 | /* | |
311 | * (new leaf node)[ln] | |
312 | * / \ | |
313 | * (old node)[fn] NULL | |
314 | */ | |
315 | ||
316 | ln = node_alloc(); | |
317 | ||
318 | if (ln == NULL) | |
319 | return NULL; | |
320 | ||
321 | ln->fn_bit = plen; | |
322 | ||
323 | ln->parent = pn; | |
324 | ||
325 | ln->fn_sernum = sernum; | |
326 | ||
327 | if (dir) | |
328 | pn->right = ln; | |
329 | else | |
330 | pn->left = ln; | |
331 | ||
332 | if (addr_bit_set(&key->addr, plen)) | |
333 | ln->right = fn; | |
334 | else | |
335 | ln->left = fn; | |
336 | ||
337 | fn->parent = ln; | |
338 | } | |
339 | return ln; | |
340 | } | |
341 | ||
342 | /* | |
343 | * Insert routing information in a node. | |
344 | */ | |
345 | ||
346 | static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, | |
0d51aa80 | 347 | struct nlmsghdr *nlh, struct netlink_skb_parms *req) |
1da177e4 LT |
348 | { |
349 | struct rt6_info *iter = NULL; | |
350 | struct rt6_info **ins; | |
351 | ||
352 | ins = &fn->leaf; | |
353 | ||
354 | if (fn->fn_flags&RTN_TL_ROOT && | |
355 | fn->leaf == &ip6_null_entry && | |
356 | !(rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) ){ | |
357 | fn->leaf = rt; | |
358 | rt->u.next = NULL; | |
359 | goto out; | |
360 | } | |
361 | ||
362 | for (iter = fn->leaf; iter; iter=iter->u.next) { | |
363 | /* | |
364 | * Search for duplicates | |
365 | */ | |
366 | ||
367 | if (iter->rt6i_metric == rt->rt6i_metric) { | |
368 | /* | |
369 | * Same priority level | |
370 | */ | |
371 | ||
372 | if (iter->rt6i_dev == rt->rt6i_dev && | |
373 | iter->rt6i_idev == rt->rt6i_idev && | |
374 | ipv6_addr_equal(&iter->rt6i_gateway, | |
375 | &rt->rt6i_gateway)) { | |
376 | if (!(iter->rt6i_flags&RTF_EXPIRES)) | |
377 | return -EEXIST; | |
378 | iter->rt6i_expires = rt->rt6i_expires; | |
379 | if (!(rt->rt6i_flags&RTF_EXPIRES)) { | |
380 | iter->rt6i_flags &= ~RTF_EXPIRES; | |
381 | iter->rt6i_expires = 0; | |
382 | } | |
383 | return -EEXIST; | |
384 | } | |
385 | } | |
386 | ||
387 | if (iter->rt6i_metric > rt->rt6i_metric) | |
388 | break; | |
389 | ||
390 | ins = &iter->u.next; | |
391 | } | |
392 | ||
393 | /* | |
394 | * insert node | |
395 | */ | |
396 | ||
397 | out: | |
398 | rt->u.next = iter; | |
399 | *ins = rt; | |
400 | rt->rt6i_node = fn; | |
401 | atomic_inc(&rt->rt6i_ref); | |
0d51aa80 | 402 | inet6_rt_notify(RTM_NEWROUTE, rt, nlh, req); |
1da177e4 LT |
403 | rt6_stats.fib_rt_entries++; |
404 | ||
405 | if ((fn->fn_flags & RTN_RTINFO) == 0) { | |
406 | rt6_stats.fib_route_nodes++; | |
407 | fn->fn_flags |= RTN_RTINFO; | |
408 | } | |
409 | ||
410 | return 0; | |
411 | } | |
412 | ||
413 | static __inline__ void fib6_start_gc(struct rt6_info *rt) | |
414 | { | |
415 | if (ip6_fib_timer.expires == 0 && | |
416 | (rt->rt6i_flags & (RTF_EXPIRES|RTF_CACHE))) | |
417 | mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval); | |
418 | } | |
419 | ||
420 | void fib6_force_start_gc(void) | |
421 | { | |
422 | if (ip6_fib_timer.expires == 0) | |
423 | mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval); | |
424 | } | |
425 | ||
426 | /* | |
427 | * Add routing information to the routing tree. | |
428 | * <destination addr>/<source addr> | |
429 | * with source addr info in sub-trees | |
430 | */ | |
431 | ||
0d51aa80 JHS |
432 | int fib6_add(struct fib6_node *root, struct rt6_info *rt, |
433 | struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req) | |
1da177e4 LT |
434 | { |
435 | struct fib6_node *fn; | |
436 | int err = -ENOMEM; | |
437 | ||
438 | fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr), | |
439 | rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst)); | |
440 | ||
441 | if (fn == NULL) | |
442 | goto out; | |
443 | ||
444 | #ifdef CONFIG_IPV6_SUBTREES | |
445 | if (rt->rt6i_src.plen) { | |
446 | struct fib6_node *sn; | |
447 | ||
448 | if (fn->subtree == NULL) { | |
449 | struct fib6_node *sfn; | |
450 | ||
451 | /* | |
452 | * Create subtree. | |
453 | * | |
454 | * fn[main tree] | |
455 | * | | |
456 | * sfn[subtree root] | |
457 | * \ | |
458 | * sn[new leaf node] | |
459 | */ | |
460 | ||
461 | /* Create subtree root node */ | |
462 | sfn = node_alloc(); | |
463 | if (sfn == NULL) | |
464 | goto st_failure; | |
465 | ||
466 | sfn->leaf = &ip6_null_entry; | |
467 | atomic_inc(&ip6_null_entry.rt6i_ref); | |
468 | sfn->fn_flags = RTN_ROOT; | |
469 | sfn->fn_sernum = fib6_new_sernum(); | |
470 | ||
471 | /* Now add the first leaf node to new subtree */ | |
472 | ||
473 | sn = fib6_add_1(sfn, &rt->rt6i_src.addr, | |
474 | sizeof(struct in6_addr), rt->rt6i_src.plen, | |
475 | offsetof(struct rt6_info, rt6i_src)); | |
476 | ||
477 | if (sn == NULL) { | |
478 | /* If it is failed, discard just allocated | |
479 | root, and then (in st_failure) stale node | |
480 | in main tree. | |
481 | */ | |
482 | node_free(sfn); | |
483 | goto st_failure; | |
484 | } | |
485 | ||
486 | /* Now link new subtree to main tree */ | |
487 | sfn->parent = fn; | |
488 | fn->subtree = sfn; | |
489 | if (fn->leaf == NULL) { | |
490 | fn->leaf = rt; | |
491 | atomic_inc(&rt->rt6i_ref); | |
492 | } | |
493 | } else { | |
494 | sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr, | |
495 | sizeof(struct in6_addr), rt->rt6i_src.plen, | |
496 | offsetof(struct rt6_info, rt6i_src)); | |
497 | ||
498 | if (sn == NULL) | |
499 | goto st_failure; | |
500 | } | |
501 | ||
502 | fn = sn; | |
503 | } | |
504 | #endif | |
505 | ||
0d51aa80 | 506 | err = fib6_add_rt2node(fn, rt, nlh, req); |
1da177e4 LT |
507 | |
508 | if (err == 0) { | |
509 | fib6_start_gc(rt); | |
510 | if (!(rt->rt6i_flags&RTF_CACHE)) | |
511 | fib6_prune_clones(fn, rt); | |
512 | } | |
513 | ||
514 | out: | |
515 | if (err) | |
516 | dst_free(&rt->u.dst); | |
517 | return err; | |
518 | ||
519 | #ifdef CONFIG_IPV6_SUBTREES | |
520 | /* Subtree creation failed, probably main tree node | |
521 | is orphan. If it is, shoot it. | |
522 | */ | |
523 | st_failure: | |
524 | if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) | |
525 | fib6_repair_tree(fn); | |
526 | dst_free(&rt->u.dst); | |
527 | return err; | |
528 | #endif | |
529 | } | |
530 | ||
531 | /* | |
532 | * Routing tree lookup | |
533 | * | |
534 | */ | |
535 | ||
536 | struct lookup_args { | |
537 | int offset; /* key offset on rt6_info */ | |
538 | struct in6_addr *addr; /* search key */ | |
539 | }; | |
540 | ||
541 | static struct fib6_node * fib6_lookup_1(struct fib6_node *root, | |
542 | struct lookup_args *args) | |
543 | { | |
544 | struct fib6_node *fn; | |
545 | int dir; | |
546 | ||
547 | /* | |
548 | * Descend on a tree | |
549 | */ | |
550 | ||
551 | fn = root; | |
552 | ||
553 | for (;;) { | |
554 | struct fib6_node *next; | |
555 | ||
556 | dir = addr_bit_set(args->addr, fn->fn_bit); | |
557 | ||
558 | next = dir ? fn->right : fn->left; | |
559 | ||
560 | if (next) { | |
561 | fn = next; | |
562 | continue; | |
563 | } | |
564 | ||
565 | break; | |
566 | } | |
567 | ||
568 | while ((fn->fn_flags & RTN_ROOT) == 0) { | |
569 | #ifdef CONFIG_IPV6_SUBTREES | |
570 | if (fn->subtree) { | |
571 | struct fib6_node *st; | |
572 | struct lookup_args *narg; | |
573 | ||
574 | narg = args + 1; | |
575 | ||
576 | if (narg->addr) { | |
577 | st = fib6_lookup_1(fn->subtree, narg); | |
578 | ||
579 | if (st && !(st->fn_flags & RTN_ROOT)) | |
580 | return st; | |
581 | } | |
582 | } | |
583 | #endif | |
584 | ||
585 | if (fn->fn_flags & RTN_RTINFO) { | |
586 | struct rt6key *key; | |
587 | ||
588 | key = (struct rt6key *) ((u8 *) fn->leaf + | |
589 | args->offset); | |
590 | ||
591 | if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) | |
592 | return fn; | |
593 | } | |
594 | ||
595 | fn = fn->parent; | |
596 | } | |
597 | ||
598 | return NULL; | |
599 | } | |
600 | ||
601 | struct fib6_node * fib6_lookup(struct fib6_node *root, struct in6_addr *daddr, | |
602 | struct in6_addr *saddr) | |
603 | { | |
604 | struct lookup_args args[2]; | |
605 | struct fib6_node *fn; | |
606 | ||
607 | args[0].offset = offsetof(struct rt6_info, rt6i_dst); | |
608 | args[0].addr = daddr; | |
609 | ||
610 | #ifdef CONFIG_IPV6_SUBTREES | |
611 | args[1].offset = offsetof(struct rt6_info, rt6i_src); | |
612 | args[1].addr = saddr; | |
613 | #endif | |
614 | ||
615 | fn = fib6_lookup_1(root, args); | |
616 | ||
617 | if (fn == NULL || fn->fn_flags & RTN_TL_ROOT) | |
618 | fn = root; | |
619 | ||
620 | return fn; | |
621 | } | |
622 | ||
623 | /* | |
624 | * Get node with specified destination prefix (and source prefix, | |
625 | * if subtrees are used) | |
626 | */ | |
627 | ||
628 | ||
629 | static struct fib6_node * fib6_locate_1(struct fib6_node *root, | |
630 | struct in6_addr *addr, | |
631 | int plen, int offset) | |
632 | { | |
633 | struct fib6_node *fn; | |
634 | ||
635 | for (fn = root; fn ; ) { | |
636 | struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset); | |
637 | ||
638 | /* | |
639 | * Prefix match | |
640 | */ | |
641 | if (plen < fn->fn_bit || | |
642 | !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) | |
643 | return NULL; | |
644 | ||
645 | if (plen == fn->fn_bit) | |
646 | return fn; | |
647 | ||
648 | /* | |
649 | * We have more bits to go | |
650 | */ | |
651 | if (addr_bit_set(addr, fn->fn_bit)) | |
652 | fn = fn->right; | |
653 | else | |
654 | fn = fn->left; | |
655 | } | |
656 | return NULL; | |
657 | } | |
658 | ||
659 | struct fib6_node * fib6_locate(struct fib6_node *root, | |
660 | struct in6_addr *daddr, int dst_len, | |
661 | struct in6_addr *saddr, int src_len) | |
662 | { | |
663 | struct fib6_node *fn; | |
664 | ||
665 | fn = fib6_locate_1(root, daddr, dst_len, | |
666 | offsetof(struct rt6_info, rt6i_dst)); | |
667 | ||
668 | #ifdef CONFIG_IPV6_SUBTREES | |
669 | if (src_len) { | |
670 | BUG_TRAP(saddr!=NULL); | |
671 | if (fn == NULL) | |
672 | fn = fn->subtree; | |
673 | if (fn) | |
674 | fn = fib6_locate_1(fn, saddr, src_len, | |
675 | offsetof(struct rt6_info, rt6i_src)); | |
676 | } | |
677 | #endif | |
678 | ||
679 | if (fn && fn->fn_flags&RTN_RTINFO) | |
680 | return fn; | |
681 | ||
682 | return NULL; | |
683 | } | |
684 | ||
685 | ||
686 | /* | |
687 | * Deletion | |
688 | * | |
689 | */ | |
690 | ||
691 | static struct rt6_info * fib6_find_prefix(struct fib6_node *fn) | |
692 | { | |
693 | if (fn->fn_flags&RTN_ROOT) | |
694 | return &ip6_null_entry; | |
695 | ||
696 | while(fn) { | |
697 | if(fn->left) | |
698 | return fn->left->leaf; | |
699 | ||
700 | if(fn->right) | |
701 | return fn->right->leaf; | |
702 | ||
703 | fn = SUBTREE(fn); | |
704 | } | |
705 | return NULL; | |
706 | } | |
707 | ||
708 | /* | |
709 | * Called to trim the tree of intermediate nodes when possible. "fn" | |
710 | * is the node we want to try and remove. | |
711 | */ | |
712 | ||
713 | static struct fib6_node * fib6_repair_tree(struct fib6_node *fn) | |
714 | { | |
715 | int children; | |
716 | int nstate; | |
717 | struct fib6_node *child, *pn; | |
718 | struct fib6_walker_t *w; | |
719 | int iter = 0; | |
720 | ||
721 | for (;;) { | |
722 | RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); | |
723 | iter++; | |
724 | ||
725 | BUG_TRAP(!(fn->fn_flags&RTN_RTINFO)); | |
726 | BUG_TRAP(!(fn->fn_flags&RTN_TL_ROOT)); | |
727 | BUG_TRAP(fn->leaf==NULL); | |
728 | ||
729 | children = 0; | |
730 | child = NULL; | |
731 | if (fn->right) child = fn->right, children |= 1; | |
732 | if (fn->left) child = fn->left, children |= 2; | |
733 | ||
734 | if (children == 3 || SUBTREE(fn) | |
735 | #ifdef CONFIG_IPV6_SUBTREES | |
736 | /* Subtree root (i.e. fn) may have one child */ | |
737 | || (children && fn->fn_flags&RTN_ROOT) | |
738 | #endif | |
739 | ) { | |
740 | fn->leaf = fib6_find_prefix(fn); | |
741 | #if RT6_DEBUG >= 2 | |
742 | if (fn->leaf==NULL) { | |
743 | BUG_TRAP(fn->leaf); | |
744 | fn->leaf = &ip6_null_entry; | |
745 | } | |
746 | #endif | |
747 | atomic_inc(&fn->leaf->rt6i_ref); | |
748 | return fn->parent; | |
749 | } | |
750 | ||
751 | pn = fn->parent; | |
752 | #ifdef CONFIG_IPV6_SUBTREES | |
753 | if (SUBTREE(pn) == fn) { | |
754 | BUG_TRAP(fn->fn_flags&RTN_ROOT); | |
755 | SUBTREE(pn) = NULL; | |
756 | nstate = FWS_L; | |
757 | } else { | |
758 | BUG_TRAP(!(fn->fn_flags&RTN_ROOT)); | |
759 | #endif | |
760 | if (pn->right == fn) pn->right = child; | |
761 | else if (pn->left == fn) pn->left = child; | |
762 | #if RT6_DEBUG >= 2 | |
763 | else BUG_TRAP(0); | |
764 | #endif | |
765 | if (child) | |
766 | child->parent = pn; | |
767 | nstate = FWS_R; | |
768 | #ifdef CONFIG_IPV6_SUBTREES | |
769 | } | |
770 | #endif | |
771 | ||
772 | read_lock(&fib6_walker_lock); | |
773 | FOR_WALKERS(w) { | |
774 | if (child == NULL) { | |
775 | if (w->root == fn) { | |
776 | w->root = w->node = NULL; | |
777 | RT6_TRACE("W %p adjusted by delroot 1\n", w); | |
778 | } else if (w->node == fn) { | |
779 | RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); | |
780 | w->node = pn; | |
781 | w->state = nstate; | |
782 | } | |
783 | } else { | |
784 | if (w->root == fn) { | |
785 | w->root = child; | |
786 | RT6_TRACE("W %p adjusted by delroot 2\n", w); | |
787 | } | |
788 | if (w->node == fn) { | |
789 | w->node = child; | |
790 | if (children&2) { | |
791 | RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); | |
792 | w->state = w->state>=FWS_R ? FWS_U : FWS_INIT; | |
793 | } else { | |
794 | RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); | |
795 | w->state = w->state>=FWS_C ? FWS_U : FWS_INIT; | |
796 | } | |
797 | } | |
798 | } | |
799 | } | |
800 | read_unlock(&fib6_walker_lock); | |
801 | ||
802 | node_free(fn); | |
803 | if (pn->fn_flags&RTN_RTINFO || SUBTREE(pn)) | |
804 | return pn; | |
805 | ||
806 | rt6_release(pn->leaf); | |
807 | pn->leaf = NULL; | |
808 | fn = pn; | |
809 | } | |
810 | } | |
811 | ||
812 | static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, | |
0d51aa80 | 813 | struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req) |
1da177e4 LT |
814 | { |
815 | struct fib6_walker_t *w; | |
816 | struct rt6_info *rt = *rtp; | |
817 | ||
818 | RT6_TRACE("fib6_del_route\n"); | |
819 | ||
820 | /* Unlink it */ | |
821 | *rtp = rt->u.next; | |
822 | rt->rt6i_node = NULL; | |
823 | rt6_stats.fib_rt_entries--; | |
824 | rt6_stats.fib_discarded_routes++; | |
825 | ||
826 | /* Adjust walkers */ | |
827 | read_lock(&fib6_walker_lock); | |
828 | FOR_WALKERS(w) { | |
829 | if (w->state == FWS_C && w->leaf == rt) { | |
830 | RT6_TRACE("walker %p adjusted by delroute\n", w); | |
831 | w->leaf = rt->u.next; | |
832 | if (w->leaf == NULL) | |
833 | w->state = FWS_U; | |
834 | } | |
835 | } | |
836 | read_unlock(&fib6_walker_lock); | |
837 | ||
838 | rt->u.next = NULL; | |
839 | ||
840 | if (fn->leaf == NULL && fn->fn_flags&RTN_TL_ROOT) | |
841 | fn->leaf = &ip6_null_entry; | |
842 | ||
843 | /* If it was last route, expunge its radix tree node */ | |
844 | if (fn->leaf == NULL) { | |
845 | fn->fn_flags &= ~RTN_RTINFO; | |
846 | rt6_stats.fib_route_nodes--; | |
847 | fn = fib6_repair_tree(fn); | |
848 | } | |
849 | ||
850 | if (atomic_read(&rt->rt6i_ref) != 1) { | |
851 | /* This route is used as dummy address holder in some split | |
852 | * nodes. It is not leaked, but it still holds other resources, | |
853 | * which must be released in time. So, scan ascendant nodes | |
854 | * and replace dummy references to this route with references | |
855 | * to still alive ones. | |
856 | */ | |
857 | while (fn) { | |
858 | if (!(fn->fn_flags&RTN_RTINFO) && fn->leaf == rt) { | |
859 | fn->leaf = fib6_find_prefix(fn); | |
860 | atomic_inc(&fn->leaf->rt6i_ref); | |
861 | rt6_release(rt); | |
862 | } | |
863 | fn = fn->parent; | |
864 | } | |
865 | /* No more references are possible at this point. */ | |
866 | if (atomic_read(&rt->rt6i_ref) != 1) BUG(); | |
867 | } | |
868 | ||
0d51aa80 | 869 | inet6_rt_notify(RTM_DELROUTE, rt, nlh, req); |
1da177e4 LT |
870 | rt6_release(rt); |
871 | } | |
872 | ||
0d51aa80 | 873 | int fib6_del(struct rt6_info *rt, struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req) |
1da177e4 LT |
874 | { |
875 | struct fib6_node *fn = rt->rt6i_node; | |
876 | struct rt6_info **rtp; | |
877 | ||
878 | #if RT6_DEBUG >= 2 | |
879 | if (rt->u.dst.obsolete>0) { | |
880 | BUG_TRAP(fn==NULL); | |
881 | return -ENOENT; | |
882 | } | |
883 | #endif | |
884 | if (fn == NULL || rt == &ip6_null_entry) | |
885 | return -ENOENT; | |
886 | ||
887 | BUG_TRAP(fn->fn_flags&RTN_RTINFO); | |
888 | ||
889 | if (!(rt->rt6i_flags&RTF_CACHE)) | |
890 | fib6_prune_clones(fn, rt); | |
891 | ||
892 | /* | |
893 | * Walk the leaf entries looking for ourself | |
894 | */ | |
895 | ||
896 | for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->u.next) { | |
897 | if (*rtp == rt) { | |
0d51aa80 | 898 | fib6_del_route(fn, rtp, nlh, _rtattr, req); |
1da177e4 LT |
899 | return 0; |
900 | } | |
901 | } | |
902 | return -ENOENT; | |
903 | } | |
904 | ||
905 | /* | |
906 | * Tree traversal function. | |
907 | * | |
908 | * Certainly, it is not interrupt safe. | |
909 | * However, it is internally reenterable wrt itself and fib6_add/fib6_del. | |
910 | * It means, that we can modify tree during walking | |
911 | * and use this function for garbage collection, clone pruning, | |
912 | * cleaning tree when a device goes down etc. etc. | |
913 | * | |
914 | * It guarantees that every node will be traversed, | |
915 | * and that it will be traversed only once. | |
916 | * | |
917 | * Callback function w->func may return: | |
918 | * 0 -> continue walking. | |
919 | * positive value -> walking is suspended (used by tree dumps, | |
920 | * and probably by gc, if it will be split to several slices) | |
921 | * negative value -> terminate walking. | |
922 | * | |
923 | * The function itself returns: | |
924 | * 0 -> walk is complete. | |
925 | * >0 -> walk is incomplete (i.e. suspended) | |
926 | * <0 -> walk is terminated by an error. | |
927 | */ | |
928 | ||
929 | int fib6_walk_continue(struct fib6_walker_t *w) | |
930 | { | |
931 | struct fib6_node *fn, *pn; | |
932 | ||
933 | for (;;) { | |
934 | fn = w->node; | |
935 | if (fn == NULL) | |
936 | return 0; | |
937 | ||
938 | if (w->prune && fn != w->root && | |
939 | fn->fn_flags&RTN_RTINFO && w->state < FWS_C) { | |
940 | w->state = FWS_C; | |
941 | w->leaf = fn->leaf; | |
942 | } | |
943 | switch (w->state) { | |
944 | #ifdef CONFIG_IPV6_SUBTREES | |
945 | case FWS_S: | |
946 | if (SUBTREE(fn)) { | |
947 | w->node = SUBTREE(fn); | |
948 | continue; | |
949 | } | |
950 | w->state = FWS_L; | |
951 | #endif | |
952 | case FWS_L: | |
953 | if (fn->left) { | |
954 | w->node = fn->left; | |
955 | w->state = FWS_INIT; | |
956 | continue; | |
957 | } | |
958 | w->state = FWS_R; | |
959 | case FWS_R: | |
960 | if (fn->right) { | |
961 | w->node = fn->right; | |
962 | w->state = FWS_INIT; | |
963 | continue; | |
964 | } | |
965 | w->state = FWS_C; | |
966 | w->leaf = fn->leaf; | |
967 | case FWS_C: | |
968 | if (w->leaf && fn->fn_flags&RTN_RTINFO) { | |
969 | int err = w->func(w); | |
970 | if (err) | |
971 | return err; | |
972 | continue; | |
973 | } | |
974 | w->state = FWS_U; | |
975 | case FWS_U: | |
976 | if (fn == w->root) | |
977 | return 0; | |
978 | pn = fn->parent; | |
979 | w->node = pn; | |
980 | #ifdef CONFIG_IPV6_SUBTREES | |
981 | if (SUBTREE(pn) == fn) { | |
982 | BUG_TRAP(fn->fn_flags&RTN_ROOT); | |
983 | w->state = FWS_L; | |
984 | continue; | |
985 | } | |
986 | #endif | |
987 | if (pn->left == fn) { | |
988 | w->state = FWS_R; | |
989 | continue; | |
990 | } | |
991 | if (pn->right == fn) { | |
992 | w->state = FWS_C; | |
993 | w->leaf = w->node->leaf; | |
994 | continue; | |
995 | } | |
996 | #if RT6_DEBUG >= 2 | |
997 | BUG_TRAP(0); | |
998 | #endif | |
999 | } | |
1000 | } | |
1001 | } | |
1002 | ||
1003 | int fib6_walk(struct fib6_walker_t *w) | |
1004 | { | |
1005 | int res; | |
1006 | ||
1007 | w->state = FWS_INIT; | |
1008 | w->node = w->root; | |
1009 | ||
1010 | fib6_walker_link(w); | |
1011 | res = fib6_walk_continue(w); | |
1012 | if (res <= 0) | |
1013 | fib6_walker_unlink(w); | |
1014 | return res; | |
1015 | } | |
1016 | ||
1017 | static int fib6_clean_node(struct fib6_walker_t *w) | |
1018 | { | |
1019 | int res; | |
1020 | struct rt6_info *rt; | |
1021 | struct fib6_cleaner_t *c = (struct fib6_cleaner_t*)w; | |
1022 | ||
1023 | for (rt = w->leaf; rt; rt = rt->u.next) { | |
1024 | res = c->func(rt, c->arg); | |
1025 | if (res < 0) { | |
1026 | w->leaf = rt; | |
0d51aa80 | 1027 | res = fib6_del(rt, NULL, NULL, NULL); |
1da177e4 LT |
1028 | if (res) { |
1029 | #if RT6_DEBUG >= 2 | |
1030 | printk(KERN_DEBUG "fib6_clean_node: del failed: rt=%p@%p err=%d\n", rt, rt->rt6i_node, res); | |
1031 | #endif | |
1032 | continue; | |
1033 | } | |
1034 | return 0; | |
1035 | } | |
1036 | BUG_TRAP(res==0); | |
1037 | } | |
1038 | w->leaf = rt; | |
1039 | return 0; | |
1040 | } | |
1041 | ||
1042 | /* | |
1043 | * Convenient frontend to tree walker. | |
1044 | * | |
1045 | * func is called on each route. | |
1046 | * It may return -1 -> delete this route. | |
1047 | * 0 -> continue walking | |
1048 | * | |
1049 | * prune==1 -> only immediate children of node (certainly, | |
1050 | * ignoring pure split nodes) will be scanned. | |
1051 | */ | |
1052 | ||
1053 | void fib6_clean_tree(struct fib6_node *root, | |
1054 | int (*func)(struct rt6_info *, void *arg), | |
1055 | int prune, void *arg) | |
1056 | { | |
1057 | struct fib6_cleaner_t c; | |
1058 | ||
1059 | c.w.root = root; | |
1060 | c.w.func = fib6_clean_node; | |
1061 | c.w.prune = prune; | |
1062 | c.func = func; | |
1063 | c.arg = arg; | |
1064 | ||
1065 | fib6_walk(&c.w); | |
1066 | } | |
1067 | ||
1068 | static int fib6_prune_clone(struct rt6_info *rt, void *arg) | |
1069 | { | |
1070 | if (rt->rt6i_flags & RTF_CACHE) { | |
1071 | RT6_TRACE("pruning clone %p\n", rt); | |
1072 | return -1; | |
1073 | } | |
1074 | ||
1075 | return 0; | |
1076 | } | |
1077 | ||
1078 | static void fib6_prune_clones(struct fib6_node *fn, struct rt6_info *rt) | |
1079 | { | |
1080 | fib6_clean_tree(fn, fib6_prune_clone, 1, rt); | |
1081 | } | |
1082 | ||
1083 | /* | |
1084 | * Garbage collection | |
1085 | */ | |
1086 | ||
1087 | static struct fib6_gc_args | |
1088 | { | |
1089 | int timeout; | |
1090 | int more; | |
1091 | } gc_args; | |
1092 | ||
1093 | static int fib6_age(struct rt6_info *rt, void *arg) | |
1094 | { | |
1095 | unsigned long now = jiffies; | |
1096 | ||
1097 | /* | |
1098 | * check addrconf expiration here. | |
1099 | * Routes are expired even if they are in use. | |
1100 | * | |
1101 | * Also age clones. Note, that clones are aged out | |
1102 | * only if they are not in use now. | |
1103 | */ | |
1104 | ||
1105 | if (rt->rt6i_flags&RTF_EXPIRES && rt->rt6i_expires) { | |
1106 | if (time_after(now, rt->rt6i_expires)) { | |
1107 | RT6_TRACE("expiring %p\n", rt); | |
1da177e4 LT |
1108 | return -1; |
1109 | } | |
1110 | gc_args.more++; | |
1111 | } else if (rt->rt6i_flags & RTF_CACHE) { | |
1112 | if (atomic_read(&rt->u.dst.__refcnt) == 0 && | |
1113 | time_after_eq(now, rt->u.dst.lastuse + gc_args.timeout)) { | |
1114 | RT6_TRACE("aging clone %p\n", rt); | |
1115 | return -1; | |
1116 | } else if ((rt->rt6i_flags & RTF_GATEWAY) && | |
1117 | (!(rt->rt6i_nexthop->flags & NTF_ROUTER))) { | |
1118 | RT6_TRACE("purging route %p via non-router but gateway\n", | |
1119 | rt); | |
1120 | return -1; | |
1121 | } | |
1122 | gc_args.more++; | |
1123 | } | |
1124 | ||
1125 | return 0; | |
1126 | } | |
1127 | ||
1128 | static DEFINE_SPINLOCK(fib6_gc_lock); | |
1129 | ||
1130 | void fib6_run_gc(unsigned long dummy) | |
1131 | { | |
1132 | if (dummy != ~0UL) { | |
1133 | spin_lock_bh(&fib6_gc_lock); | |
1134 | gc_args.timeout = dummy ? (int)dummy : ip6_rt_gc_interval; | |
1135 | } else { | |
1136 | local_bh_disable(); | |
1137 | if (!spin_trylock(&fib6_gc_lock)) { | |
1138 | mod_timer(&ip6_fib_timer, jiffies + HZ); | |
1139 | local_bh_enable(); | |
1140 | return; | |
1141 | } | |
1142 | gc_args.timeout = ip6_rt_gc_interval; | |
1143 | } | |
1144 | gc_args.more = 0; | |
1145 | ||
1146 | ||
1147 | write_lock_bh(&rt6_lock); | |
1148 | ndisc_dst_gc(&gc_args.more); | |
1149 | fib6_clean_tree(&ip6_routing_table, fib6_age, 0, NULL); | |
1150 | write_unlock_bh(&rt6_lock); | |
1151 | ||
1152 | if (gc_args.more) | |
1153 | mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval); | |
1154 | else { | |
1155 | del_timer(&ip6_fib_timer); | |
1156 | ip6_fib_timer.expires = 0; | |
1157 | } | |
1158 | spin_unlock_bh(&fib6_gc_lock); | |
1159 | } | |
1160 | ||
1161 | void __init fib6_init(void) | |
1162 | { | |
1163 | fib6_node_kmem = kmem_cache_create("fib6_nodes", | |
1164 | sizeof(struct fib6_node), | |
1165 | 0, SLAB_HWCACHE_ALIGN, | |
1166 | NULL, NULL); | |
1167 | if (!fib6_node_kmem) | |
1168 | panic("cannot create fib6_nodes cache"); | |
1169 | } | |
1170 | ||
1171 | void fib6_gc_cleanup(void) | |
1172 | { | |
1173 | del_timer(&ip6_fib_timer); | |
1174 | kmem_cache_destroy(fib6_node_kmem); | |
1175 | } |