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ipip, sit: fix ipv4_{update_pmtu,redirect} calls
[deliverable/linux.git] / net / ipv6 / ip6_fib.c
1 /*
2 * Linux INET6 implementation
3 * Forwarding Information Database
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 *
13 * Changes:
14 * Yuji SEKIYA @USAGI: Support default route on router node;
15 * remove ip6_null_entry from the top of
16 * routing table.
17 * Ville Nuorvala: Fixed routing subtrees.
18 */
19
20 #define pr_fmt(fmt) "IPv6: " fmt
21
22 #include <linux/errno.h>
23 #include <linux/types.h>
24 #include <linux/net.h>
25 #include <linux/route.h>
26 #include <linux/netdevice.h>
27 #include <linux/in6.h>
28 #include <linux/init.h>
29 #include <linux/list.h>
30 #include <linux/slab.h>
31
32 #include <net/ipv6.h>
33 #include <net/ndisc.h>
34 #include <net/addrconf.h>
35
36 #include <net/ip6_fib.h>
37 #include <net/ip6_route.h>
38
39 #define RT6_DEBUG 2
40
41 #if RT6_DEBUG >= 3
42 #define RT6_TRACE(x...) pr_debug(x)
43 #else
44 #define RT6_TRACE(x...) do { ; } while (0)
45 #endif
46
47 static struct kmem_cache *fib6_node_kmem __read_mostly;
48
49 enum fib_walk_state_t {
50 #ifdef CONFIG_IPV6_SUBTREES
51 FWS_S,
52 #endif
53 FWS_L,
54 FWS_R,
55 FWS_C,
56 FWS_U
57 };
58
59 struct fib6_cleaner_t {
60 struct fib6_walker_t w;
61 struct net *net;
62 int (*func)(struct rt6_info *, void *arg);
63 void *arg;
64 };
65
66 static DEFINE_RWLOCK(fib6_walker_lock);
67
68 #ifdef CONFIG_IPV6_SUBTREES
69 #define FWS_INIT FWS_S
70 #else
71 #define FWS_INIT FWS_L
72 #endif
73
74 static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
75 struct rt6_info *rt);
76 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn);
77 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn);
78 static int fib6_walk(struct fib6_walker_t *w);
79 static int fib6_walk_continue(struct fib6_walker_t *w);
80
81 /*
82 * A routing update causes an increase of the serial number on the
83 * affected subtree. This allows for cached routes to be asynchronously
84 * tested when modifications are made to the destination cache as a
85 * result of redirects, path MTU changes, etc.
86 */
87
88 static __u32 rt_sernum;
89
90 static void fib6_gc_timer_cb(unsigned long arg);
91
92 static LIST_HEAD(fib6_walkers);
93 #define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh)
94
95 static inline void fib6_walker_link(struct fib6_walker_t *w)
96 {
97 write_lock_bh(&fib6_walker_lock);
98 list_add(&w->lh, &fib6_walkers);
99 write_unlock_bh(&fib6_walker_lock);
100 }
101
102 static inline void fib6_walker_unlink(struct fib6_walker_t *w)
103 {
104 write_lock_bh(&fib6_walker_lock);
105 list_del(&w->lh);
106 write_unlock_bh(&fib6_walker_lock);
107 }
108 static __inline__ u32 fib6_new_sernum(void)
109 {
110 u32 n = ++rt_sernum;
111 if ((__s32)n <= 0)
112 rt_sernum = n = 1;
113 return n;
114 }
115
116 /*
117 * Auxiliary address test functions for the radix tree.
118 *
119 * These assume a 32bit processor (although it will work on
120 * 64bit processors)
121 */
122
123 /*
124 * test bit
125 */
126 #if defined(__LITTLE_ENDIAN)
127 # define BITOP_BE32_SWIZZLE (0x1F & ~7)
128 #else
129 # define BITOP_BE32_SWIZZLE 0
130 #endif
131
132 static __inline__ __be32 addr_bit_set(const void *token, int fn_bit)
133 {
134 const __be32 *addr = token;
135 /*
136 * Here,
137 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
138 * is optimized version of
139 * htonl(1 << ((~fn_bit)&0x1F))
140 * See include/asm-generic/bitops/le.h.
141 */
142 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
143 addr[fn_bit >> 5];
144 }
145
146 static __inline__ struct fib6_node *node_alloc(void)
147 {
148 struct fib6_node *fn;
149
150 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
151
152 return fn;
153 }
154
155 static __inline__ void node_free(struct fib6_node *fn)
156 {
157 kmem_cache_free(fib6_node_kmem, fn);
158 }
159
160 static __inline__ void rt6_release(struct rt6_info *rt)
161 {
162 if (atomic_dec_and_test(&rt->rt6i_ref))
163 dst_free(&rt->dst);
164 }
165
166 static void fib6_link_table(struct net *net, struct fib6_table *tb)
167 {
168 unsigned int h;
169
170 /*
171 * Initialize table lock at a single place to give lockdep a key,
172 * tables aren't visible prior to being linked to the list.
173 */
174 rwlock_init(&tb->tb6_lock);
175
176 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
177
178 /*
179 * No protection necessary, this is the only list mutatation
180 * operation, tables never disappear once they exist.
181 */
182 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
183 }
184
185 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
186
187 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
188 {
189 struct fib6_table *table;
190
191 table = kzalloc(sizeof(*table), GFP_ATOMIC);
192 if (table) {
193 table->tb6_id = id;
194 table->tb6_root.leaf = net->ipv6.ip6_null_entry;
195 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
196 inet_peer_base_init(&table->tb6_peers);
197 }
198
199 return table;
200 }
201
202 struct fib6_table *fib6_new_table(struct net *net, u32 id)
203 {
204 struct fib6_table *tb;
205
206 if (id == 0)
207 id = RT6_TABLE_MAIN;
208 tb = fib6_get_table(net, id);
209 if (tb)
210 return tb;
211
212 tb = fib6_alloc_table(net, id);
213 if (tb)
214 fib6_link_table(net, tb);
215
216 return tb;
217 }
218
219 struct fib6_table *fib6_get_table(struct net *net, u32 id)
220 {
221 struct fib6_table *tb;
222 struct hlist_head *head;
223 unsigned int h;
224
225 if (id == 0)
226 id = RT6_TABLE_MAIN;
227 h = id & (FIB6_TABLE_HASHSZ - 1);
228 rcu_read_lock();
229 head = &net->ipv6.fib_table_hash[h];
230 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
231 if (tb->tb6_id == id) {
232 rcu_read_unlock();
233 return tb;
234 }
235 }
236 rcu_read_unlock();
237
238 return NULL;
239 }
240
241 static void __net_init fib6_tables_init(struct net *net)
242 {
243 fib6_link_table(net, net->ipv6.fib6_main_tbl);
244 fib6_link_table(net, net->ipv6.fib6_local_tbl);
245 }
246 #else
247
248 struct fib6_table *fib6_new_table(struct net *net, u32 id)
249 {
250 return fib6_get_table(net, id);
251 }
252
253 struct fib6_table *fib6_get_table(struct net *net, u32 id)
254 {
255 return net->ipv6.fib6_main_tbl;
256 }
257
258 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
259 int flags, pol_lookup_t lookup)
260 {
261 return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl6, flags);
262 }
263
264 static void __net_init fib6_tables_init(struct net *net)
265 {
266 fib6_link_table(net, net->ipv6.fib6_main_tbl);
267 }
268
269 #endif
270
271 static int fib6_dump_node(struct fib6_walker_t *w)
272 {
273 int res;
274 struct rt6_info *rt;
275
276 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
277 res = rt6_dump_route(rt, w->args);
278 if (res < 0) {
279 /* Frame is full, suspend walking */
280 w->leaf = rt;
281 return 1;
282 }
283 WARN_ON(res == 0);
284 }
285 w->leaf = NULL;
286 return 0;
287 }
288
289 static void fib6_dump_end(struct netlink_callback *cb)
290 {
291 struct fib6_walker_t *w = (void *)cb->args[2];
292
293 if (w) {
294 if (cb->args[4]) {
295 cb->args[4] = 0;
296 fib6_walker_unlink(w);
297 }
298 cb->args[2] = 0;
299 kfree(w);
300 }
301 cb->done = (void *)cb->args[3];
302 cb->args[1] = 3;
303 }
304
305 static int fib6_dump_done(struct netlink_callback *cb)
306 {
307 fib6_dump_end(cb);
308 return cb->done ? cb->done(cb) : 0;
309 }
310
311 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
312 struct netlink_callback *cb)
313 {
314 struct fib6_walker_t *w;
315 int res;
316
317 w = (void *)cb->args[2];
318 w->root = &table->tb6_root;
319
320 if (cb->args[4] == 0) {
321 w->count = 0;
322 w->skip = 0;
323
324 read_lock_bh(&table->tb6_lock);
325 res = fib6_walk(w);
326 read_unlock_bh(&table->tb6_lock);
327 if (res > 0) {
328 cb->args[4] = 1;
329 cb->args[5] = w->root->fn_sernum;
330 }
331 } else {
332 if (cb->args[5] != w->root->fn_sernum) {
333 /* Begin at the root if the tree changed */
334 cb->args[5] = w->root->fn_sernum;
335 w->state = FWS_INIT;
336 w->node = w->root;
337 w->skip = w->count;
338 } else
339 w->skip = 0;
340
341 read_lock_bh(&table->tb6_lock);
342 res = fib6_walk_continue(w);
343 read_unlock_bh(&table->tb6_lock);
344 if (res <= 0) {
345 fib6_walker_unlink(w);
346 cb->args[4] = 0;
347 }
348 }
349
350 return res;
351 }
352
353 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
354 {
355 struct net *net = sock_net(skb->sk);
356 unsigned int h, s_h;
357 unsigned int e = 0, s_e;
358 struct rt6_rtnl_dump_arg arg;
359 struct fib6_walker_t *w;
360 struct fib6_table *tb;
361 struct hlist_head *head;
362 int res = 0;
363
364 s_h = cb->args[0];
365 s_e = cb->args[1];
366
367 w = (void *)cb->args[2];
368 if (!w) {
369 /* New dump:
370 *
371 * 1. hook callback destructor.
372 */
373 cb->args[3] = (long)cb->done;
374 cb->done = fib6_dump_done;
375
376 /*
377 * 2. allocate and initialize walker.
378 */
379 w = kzalloc(sizeof(*w), GFP_ATOMIC);
380 if (!w)
381 return -ENOMEM;
382 w->func = fib6_dump_node;
383 cb->args[2] = (long)w;
384 }
385
386 arg.skb = skb;
387 arg.cb = cb;
388 arg.net = net;
389 w->args = &arg;
390
391 rcu_read_lock();
392 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
393 e = 0;
394 head = &net->ipv6.fib_table_hash[h];
395 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
396 if (e < s_e)
397 goto next;
398 res = fib6_dump_table(tb, skb, cb);
399 if (res != 0)
400 goto out;
401 next:
402 e++;
403 }
404 }
405 out:
406 rcu_read_unlock();
407 cb->args[1] = e;
408 cb->args[0] = h;
409
410 res = res < 0 ? res : skb->len;
411 if (res <= 0)
412 fib6_dump_end(cb);
413 return res;
414 }
415
416 /*
417 * Routing Table
418 *
419 * return the appropriate node for a routing tree "add" operation
420 * by either creating and inserting or by returning an existing
421 * node.
422 */
423
424 static struct fib6_node *fib6_add_1(struct fib6_node *root,
425 struct in6_addr *addr, int plen,
426 int offset, int allow_create,
427 int replace_required)
428 {
429 struct fib6_node *fn, *in, *ln;
430 struct fib6_node *pn = NULL;
431 struct rt6key *key;
432 int bit;
433 __be32 dir = 0;
434 __u32 sernum = fib6_new_sernum();
435
436 RT6_TRACE("fib6_add_1\n");
437
438 /* insert node in tree */
439
440 fn = root;
441
442 do {
443 key = (struct rt6key *)((u8 *)fn->leaf + offset);
444
445 /*
446 * Prefix match
447 */
448 if (plen < fn->fn_bit ||
449 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
450 if (!allow_create) {
451 if (replace_required) {
452 pr_warn("Can't replace route, no match found\n");
453 return ERR_PTR(-ENOENT);
454 }
455 pr_warn("NLM_F_CREATE should be set when creating new route\n");
456 }
457 goto insert_above;
458 }
459
460 /*
461 * Exact match ?
462 */
463
464 if (plen == fn->fn_bit) {
465 /* clean up an intermediate node */
466 if (!(fn->fn_flags & RTN_RTINFO)) {
467 rt6_release(fn->leaf);
468 fn->leaf = NULL;
469 }
470
471 fn->fn_sernum = sernum;
472
473 return fn;
474 }
475
476 /*
477 * We have more bits to go
478 */
479
480 /* Try to walk down on tree. */
481 fn->fn_sernum = sernum;
482 dir = addr_bit_set(addr, fn->fn_bit);
483 pn = fn;
484 fn = dir ? fn->right : fn->left;
485 } while (fn);
486
487 if (!allow_create) {
488 /* We should not create new node because
489 * NLM_F_REPLACE was specified without NLM_F_CREATE
490 * I assume it is safe to require NLM_F_CREATE when
491 * REPLACE flag is used! Later we may want to remove the
492 * check for replace_required, because according
493 * to netlink specification, NLM_F_CREATE
494 * MUST be specified if new route is created.
495 * That would keep IPv6 consistent with IPv4
496 */
497 if (replace_required) {
498 pr_warn("Can't replace route, no match found\n");
499 return ERR_PTR(-ENOENT);
500 }
501 pr_warn("NLM_F_CREATE should be set when creating new route\n");
502 }
503 /*
504 * We walked to the bottom of tree.
505 * Create new leaf node without children.
506 */
507
508 ln = node_alloc();
509
510 if (!ln)
511 return ERR_PTR(-ENOMEM);
512 ln->fn_bit = plen;
513
514 ln->parent = pn;
515 ln->fn_sernum = sernum;
516
517 if (dir)
518 pn->right = ln;
519 else
520 pn->left = ln;
521
522 return ln;
523
524
525 insert_above:
526 /*
527 * split since we don't have a common prefix anymore or
528 * we have a less significant route.
529 * we've to insert an intermediate node on the list
530 * this new node will point to the one we need to create
531 * and the current
532 */
533
534 pn = fn->parent;
535
536 /* find 1st bit in difference between the 2 addrs.
537
538 See comment in __ipv6_addr_diff: bit may be an invalid value,
539 but if it is >= plen, the value is ignored in any case.
540 */
541
542 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr));
543
544 /*
545 * (intermediate)[in]
546 * / \
547 * (new leaf node)[ln] (old node)[fn]
548 */
549 if (plen > bit) {
550 in = node_alloc();
551 ln = node_alloc();
552
553 if (!in || !ln) {
554 if (in)
555 node_free(in);
556 if (ln)
557 node_free(ln);
558 return ERR_PTR(-ENOMEM);
559 }
560
561 /*
562 * new intermediate node.
563 * RTN_RTINFO will
564 * be off since that an address that chooses one of
565 * the branches would not match less specific routes
566 * in the other branch
567 */
568
569 in->fn_bit = bit;
570
571 in->parent = pn;
572 in->leaf = fn->leaf;
573 atomic_inc(&in->leaf->rt6i_ref);
574
575 in->fn_sernum = sernum;
576
577 /* update parent pointer */
578 if (dir)
579 pn->right = in;
580 else
581 pn->left = in;
582
583 ln->fn_bit = plen;
584
585 ln->parent = in;
586 fn->parent = in;
587
588 ln->fn_sernum = sernum;
589
590 if (addr_bit_set(addr, bit)) {
591 in->right = ln;
592 in->left = fn;
593 } else {
594 in->left = ln;
595 in->right = fn;
596 }
597 } else { /* plen <= bit */
598
599 /*
600 * (new leaf node)[ln]
601 * / \
602 * (old node)[fn] NULL
603 */
604
605 ln = node_alloc();
606
607 if (!ln)
608 return ERR_PTR(-ENOMEM);
609
610 ln->fn_bit = plen;
611
612 ln->parent = pn;
613
614 ln->fn_sernum = sernum;
615
616 if (dir)
617 pn->right = ln;
618 else
619 pn->left = ln;
620
621 if (addr_bit_set(&key->addr, plen))
622 ln->right = fn;
623 else
624 ln->left = fn;
625
626 fn->parent = ln;
627 }
628 return ln;
629 }
630
631 static inline bool rt6_qualify_for_ecmp(struct rt6_info *rt)
632 {
633 return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) ==
634 RTF_GATEWAY;
635 }
636
637 static int fib6_commit_metrics(struct dst_entry *dst,
638 struct nlattr *mx, int mx_len)
639 {
640 struct nlattr *nla;
641 int remaining;
642 u32 *mp;
643
644 if (dst->flags & DST_HOST) {
645 mp = dst_metrics_write_ptr(dst);
646 } else {
647 mp = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL);
648 if (!mp)
649 return -ENOMEM;
650 dst_init_metrics(dst, mp, 0);
651 }
652
653 nla_for_each_attr(nla, mx, mx_len, remaining) {
654 int type = nla_type(nla);
655
656 if (type) {
657 if (type > RTAX_MAX)
658 return -EINVAL;
659
660 mp[type - 1] = nla_get_u32(nla);
661 }
662 }
663 return 0;
664 }
665
666 /*
667 * Insert routing information in a node.
668 */
669
670 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
671 struct nl_info *info, struct nlattr *mx, int mx_len)
672 {
673 struct rt6_info *iter = NULL;
674 struct rt6_info **ins;
675 int replace = (info->nlh &&
676 (info->nlh->nlmsg_flags & NLM_F_REPLACE));
677 int add = (!info->nlh ||
678 (info->nlh->nlmsg_flags & NLM_F_CREATE));
679 int found = 0;
680 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
681 int err;
682
683 ins = &fn->leaf;
684
685 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) {
686 /*
687 * Search for duplicates
688 */
689
690 if (iter->rt6i_metric == rt->rt6i_metric) {
691 /*
692 * Same priority level
693 */
694 if (info->nlh &&
695 (info->nlh->nlmsg_flags & NLM_F_EXCL))
696 return -EEXIST;
697 if (replace) {
698 found++;
699 break;
700 }
701
702 if (iter->dst.dev == rt->dst.dev &&
703 iter->rt6i_idev == rt->rt6i_idev &&
704 ipv6_addr_equal(&iter->rt6i_gateway,
705 &rt->rt6i_gateway)) {
706 if (rt->rt6i_nsiblings)
707 rt->rt6i_nsiblings = 0;
708 if (!(iter->rt6i_flags & RTF_EXPIRES))
709 return -EEXIST;
710 if (!(rt->rt6i_flags & RTF_EXPIRES))
711 rt6_clean_expires(iter);
712 else
713 rt6_set_expires(iter, rt->dst.expires);
714 return -EEXIST;
715 }
716 /* If we have the same destination and the same metric,
717 * but not the same gateway, then the route we try to
718 * add is sibling to this route, increment our counter
719 * of siblings, and later we will add our route to the
720 * list.
721 * Only static routes (which don't have flag
722 * RTF_EXPIRES) are used for ECMPv6.
723 *
724 * To avoid long list, we only had siblings if the
725 * route have a gateway.
726 */
727 if (rt_can_ecmp &&
728 rt6_qualify_for_ecmp(iter))
729 rt->rt6i_nsiblings++;
730 }
731
732 if (iter->rt6i_metric > rt->rt6i_metric)
733 break;
734
735 ins = &iter->dst.rt6_next;
736 }
737
738 /* Reset round-robin state, if necessary */
739 if (ins == &fn->leaf)
740 fn->rr_ptr = NULL;
741
742 /* Link this route to others same route. */
743 if (rt->rt6i_nsiblings) {
744 unsigned int rt6i_nsiblings;
745 struct rt6_info *sibling, *temp_sibling;
746
747 /* Find the first route that have the same metric */
748 sibling = fn->leaf;
749 while (sibling) {
750 if (sibling->rt6i_metric == rt->rt6i_metric &&
751 rt6_qualify_for_ecmp(sibling)) {
752 list_add_tail(&rt->rt6i_siblings,
753 &sibling->rt6i_siblings);
754 break;
755 }
756 sibling = sibling->dst.rt6_next;
757 }
758 /* For each sibling in the list, increment the counter of
759 * siblings. BUG() if counters does not match, list of siblings
760 * is broken!
761 */
762 rt6i_nsiblings = 0;
763 list_for_each_entry_safe(sibling, temp_sibling,
764 &rt->rt6i_siblings, rt6i_siblings) {
765 sibling->rt6i_nsiblings++;
766 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings);
767 rt6i_nsiblings++;
768 }
769 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings);
770 }
771
772 /*
773 * insert node
774 */
775 if (!replace) {
776 if (!add)
777 pr_warn("NLM_F_CREATE should be set when creating new route\n");
778
779 add:
780 if (mx) {
781 err = fib6_commit_metrics(&rt->dst, mx, mx_len);
782 if (err)
783 return err;
784 }
785 rt->dst.rt6_next = iter;
786 *ins = rt;
787 rt->rt6i_node = fn;
788 atomic_inc(&rt->rt6i_ref);
789 inet6_rt_notify(RTM_NEWROUTE, rt, info);
790 info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
791
792 if (!(fn->fn_flags & RTN_RTINFO)) {
793 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
794 fn->fn_flags |= RTN_RTINFO;
795 }
796
797 } else {
798 if (!found) {
799 if (add)
800 goto add;
801 pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
802 return -ENOENT;
803 }
804 if (mx) {
805 err = fib6_commit_metrics(&rt->dst, mx, mx_len);
806 if (err)
807 return err;
808 }
809 *ins = rt;
810 rt->rt6i_node = fn;
811 rt->dst.rt6_next = iter->dst.rt6_next;
812 atomic_inc(&rt->rt6i_ref);
813 inet6_rt_notify(RTM_NEWROUTE, rt, info);
814 rt6_release(iter);
815 if (!(fn->fn_flags & RTN_RTINFO)) {
816 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
817 fn->fn_flags |= RTN_RTINFO;
818 }
819 }
820
821 return 0;
822 }
823
824 static __inline__ void fib6_start_gc(struct net *net, struct rt6_info *rt)
825 {
826 if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
827 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE)))
828 mod_timer(&net->ipv6.ip6_fib_timer,
829 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
830 }
831
832 void fib6_force_start_gc(struct net *net)
833 {
834 if (!timer_pending(&net->ipv6.ip6_fib_timer))
835 mod_timer(&net->ipv6.ip6_fib_timer,
836 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
837 }
838
839 /*
840 * Add routing information to the routing tree.
841 * <destination addr>/<source addr>
842 * with source addr info in sub-trees
843 */
844
845 int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info,
846 struct nlattr *mx, int mx_len)
847 {
848 struct fib6_node *fn, *pn = NULL;
849 int err = -ENOMEM;
850 int allow_create = 1;
851 int replace_required = 0;
852
853 if (info->nlh) {
854 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
855 allow_create = 0;
856 if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
857 replace_required = 1;
858 }
859 if (!allow_create && !replace_required)
860 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
861
862 fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
863 offsetof(struct rt6_info, rt6i_dst), allow_create,
864 replace_required);
865 if (IS_ERR(fn)) {
866 err = PTR_ERR(fn);
867 fn = NULL;
868 goto out;
869 }
870
871 pn = fn;
872
873 #ifdef CONFIG_IPV6_SUBTREES
874 if (rt->rt6i_src.plen) {
875 struct fib6_node *sn;
876
877 if (!fn->subtree) {
878 struct fib6_node *sfn;
879
880 /*
881 * Create subtree.
882 *
883 * fn[main tree]
884 * |
885 * sfn[subtree root]
886 * \
887 * sn[new leaf node]
888 */
889
890 /* Create subtree root node */
891 sfn = node_alloc();
892 if (!sfn)
893 goto st_failure;
894
895 sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
896 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
897 sfn->fn_flags = RTN_ROOT;
898 sfn->fn_sernum = fib6_new_sernum();
899
900 /* Now add the first leaf node to new subtree */
901
902 sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
903 rt->rt6i_src.plen,
904 offsetof(struct rt6_info, rt6i_src),
905 allow_create, replace_required);
906
907 if (IS_ERR(sn)) {
908 /* If it is failed, discard just allocated
909 root, and then (in st_failure) stale node
910 in main tree.
911 */
912 node_free(sfn);
913 err = PTR_ERR(sn);
914 goto st_failure;
915 }
916
917 /* Now link new subtree to main tree */
918 sfn->parent = fn;
919 fn->subtree = sfn;
920 } else {
921 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
922 rt->rt6i_src.plen,
923 offsetof(struct rt6_info, rt6i_src),
924 allow_create, replace_required);
925
926 if (IS_ERR(sn)) {
927 err = PTR_ERR(sn);
928 goto st_failure;
929 }
930 }
931
932 if (!fn->leaf) {
933 fn->leaf = rt;
934 atomic_inc(&rt->rt6i_ref);
935 }
936 fn = sn;
937 }
938 #endif
939
940 err = fib6_add_rt2node(fn, rt, info, mx, mx_len);
941 if (!err) {
942 fib6_start_gc(info->nl_net, rt);
943 if (!(rt->rt6i_flags & RTF_CACHE))
944 fib6_prune_clones(info->nl_net, pn, rt);
945 }
946
947 out:
948 if (err) {
949 #ifdef CONFIG_IPV6_SUBTREES
950 /*
951 * If fib6_add_1 has cleared the old leaf pointer in the
952 * super-tree leaf node we have to find a new one for it.
953 */
954 if (pn != fn && pn->leaf == rt) {
955 pn->leaf = NULL;
956 atomic_dec(&rt->rt6i_ref);
957 }
958 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
959 pn->leaf = fib6_find_prefix(info->nl_net, pn);
960 #if RT6_DEBUG >= 2
961 if (!pn->leaf) {
962 WARN_ON(pn->leaf == NULL);
963 pn->leaf = info->nl_net->ipv6.ip6_null_entry;
964 }
965 #endif
966 atomic_inc(&pn->leaf->rt6i_ref);
967 }
968 #endif
969 dst_free(&rt->dst);
970 }
971 return err;
972
973 #ifdef CONFIG_IPV6_SUBTREES
974 /* Subtree creation failed, probably main tree node
975 is orphan. If it is, shoot it.
976 */
977 st_failure:
978 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
979 fib6_repair_tree(info->nl_net, fn);
980 dst_free(&rt->dst);
981 return err;
982 #endif
983 }
984
985 /*
986 * Routing tree lookup
987 *
988 */
989
990 struct lookup_args {
991 int offset; /* key offset on rt6_info */
992 const struct in6_addr *addr; /* search key */
993 };
994
995 static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
996 struct lookup_args *args)
997 {
998 struct fib6_node *fn;
999 __be32 dir;
1000
1001 if (unlikely(args->offset == 0))
1002 return NULL;
1003
1004 /*
1005 * Descend on a tree
1006 */
1007
1008 fn = root;
1009
1010 for (;;) {
1011 struct fib6_node *next;
1012
1013 dir = addr_bit_set(args->addr, fn->fn_bit);
1014
1015 next = dir ? fn->right : fn->left;
1016
1017 if (next) {
1018 fn = next;
1019 continue;
1020 }
1021 break;
1022 }
1023
1024 while (fn) {
1025 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
1026 struct rt6key *key;
1027
1028 key = (struct rt6key *) ((u8 *) fn->leaf +
1029 args->offset);
1030
1031 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
1032 #ifdef CONFIG_IPV6_SUBTREES
1033 if (fn->subtree) {
1034 struct fib6_node *sfn;
1035 sfn = fib6_lookup_1(fn->subtree,
1036 args + 1);
1037 if (!sfn)
1038 goto backtrack;
1039 fn = sfn;
1040 }
1041 #endif
1042 if (fn->fn_flags & RTN_RTINFO)
1043 return fn;
1044 }
1045 }
1046 #ifdef CONFIG_IPV6_SUBTREES
1047 backtrack:
1048 #endif
1049 if (fn->fn_flags & RTN_ROOT)
1050 break;
1051
1052 fn = fn->parent;
1053 }
1054
1055 return NULL;
1056 }
1057
1058 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr,
1059 const struct in6_addr *saddr)
1060 {
1061 struct fib6_node *fn;
1062 struct lookup_args args[] = {
1063 {
1064 .offset = offsetof(struct rt6_info, rt6i_dst),
1065 .addr = daddr,
1066 },
1067 #ifdef CONFIG_IPV6_SUBTREES
1068 {
1069 .offset = offsetof(struct rt6_info, rt6i_src),
1070 .addr = saddr,
1071 },
1072 #endif
1073 {
1074 .offset = 0, /* sentinel */
1075 }
1076 };
1077
1078 fn = fib6_lookup_1(root, daddr ? args : args + 1);
1079 if (!fn || fn->fn_flags & RTN_TL_ROOT)
1080 fn = root;
1081
1082 return fn;
1083 }
1084
1085 /*
1086 * Get node with specified destination prefix (and source prefix,
1087 * if subtrees are used)
1088 */
1089
1090
1091 static struct fib6_node *fib6_locate_1(struct fib6_node *root,
1092 const struct in6_addr *addr,
1093 int plen, int offset)
1094 {
1095 struct fib6_node *fn;
1096
1097 for (fn = root; fn ; ) {
1098 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
1099
1100 /*
1101 * Prefix match
1102 */
1103 if (plen < fn->fn_bit ||
1104 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
1105 return NULL;
1106
1107 if (plen == fn->fn_bit)
1108 return fn;
1109
1110 /*
1111 * We have more bits to go
1112 */
1113 if (addr_bit_set(addr, fn->fn_bit))
1114 fn = fn->right;
1115 else
1116 fn = fn->left;
1117 }
1118 return NULL;
1119 }
1120
1121 struct fib6_node *fib6_locate(struct fib6_node *root,
1122 const struct in6_addr *daddr, int dst_len,
1123 const struct in6_addr *saddr, int src_len)
1124 {
1125 struct fib6_node *fn;
1126
1127 fn = fib6_locate_1(root, daddr, dst_len,
1128 offsetof(struct rt6_info, rt6i_dst));
1129
1130 #ifdef CONFIG_IPV6_SUBTREES
1131 if (src_len) {
1132 WARN_ON(saddr == NULL);
1133 if (fn && fn->subtree)
1134 fn = fib6_locate_1(fn->subtree, saddr, src_len,
1135 offsetof(struct rt6_info, rt6i_src));
1136 }
1137 #endif
1138
1139 if (fn && fn->fn_flags & RTN_RTINFO)
1140 return fn;
1141
1142 return NULL;
1143 }
1144
1145
1146 /*
1147 * Deletion
1148 *
1149 */
1150
1151 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
1152 {
1153 if (fn->fn_flags & RTN_ROOT)
1154 return net->ipv6.ip6_null_entry;
1155
1156 while (fn) {
1157 if (fn->left)
1158 return fn->left->leaf;
1159 if (fn->right)
1160 return fn->right->leaf;
1161
1162 fn = FIB6_SUBTREE(fn);
1163 }
1164 return NULL;
1165 }
1166
1167 /*
1168 * Called to trim the tree of intermediate nodes when possible. "fn"
1169 * is the node we want to try and remove.
1170 */
1171
1172 static struct fib6_node *fib6_repair_tree(struct net *net,
1173 struct fib6_node *fn)
1174 {
1175 int children;
1176 int nstate;
1177 struct fib6_node *child, *pn;
1178 struct fib6_walker_t *w;
1179 int iter = 0;
1180
1181 for (;;) {
1182 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1183 iter++;
1184
1185 WARN_ON(fn->fn_flags & RTN_RTINFO);
1186 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1187 WARN_ON(fn->leaf != NULL);
1188
1189 children = 0;
1190 child = NULL;
1191 if (fn->right)
1192 child = fn->right, children |= 1;
1193 if (fn->left)
1194 child = fn->left, children |= 2;
1195
1196 if (children == 3 || FIB6_SUBTREE(fn)
1197 #ifdef CONFIG_IPV6_SUBTREES
1198 /* Subtree root (i.e. fn) may have one child */
1199 || (children && fn->fn_flags & RTN_ROOT)
1200 #endif
1201 ) {
1202 fn->leaf = fib6_find_prefix(net, fn);
1203 #if RT6_DEBUG >= 2
1204 if (!fn->leaf) {
1205 WARN_ON(!fn->leaf);
1206 fn->leaf = net->ipv6.ip6_null_entry;
1207 }
1208 #endif
1209 atomic_inc(&fn->leaf->rt6i_ref);
1210 return fn->parent;
1211 }
1212
1213 pn = fn->parent;
1214 #ifdef CONFIG_IPV6_SUBTREES
1215 if (FIB6_SUBTREE(pn) == fn) {
1216 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1217 FIB6_SUBTREE(pn) = NULL;
1218 nstate = FWS_L;
1219 } else {
1220 WARN_ON(fn->fn_flags & RTN_ROOT);
1221 #endif
1222 if (pn->right == fn)
1223 pn->right = child;
1224 else if (pn->left == fn)
1225 pn->left = child;
1226 #if RT6_DEBUG >= 2
1227 else
1228 WARN_ON(1);
1229 #endif
1230 if (child)
1231 child->parent = pn;
1232 nstate = FWS_R;
1233 #ifdef CONFIG_IPV6_SUBTREES
1234 }
1235 #endif
1236
1237 read_lock(&fib6_walker_lock);
1238 FOR_WALKERS(w) {
1239 if (!child) {
1240 if (w->root == fn) {
1241 w->root = w->node = NULL;
1242 RT6_TRACE("W %p adjusted by delroot 1\n", w);
1243 } else if (w->node == fn) {
1244 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1245 w->node = pn;
1246 w->state = nstate;
1247 }
1248 } else {
1249 if (w->root == fn) {
1250 w->root = child;
1251 RT6_TRACE("W %p adjusted by delroot 2\n", w);
1252 }
1253 if (w->node == fn) {
1254 w->node = child;
1255 if (children&2) {
1256 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1257 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT;
1258 } else {
1259 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1260 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT;
1261 }
1262 }
1263 }
1264 }
1265 read_unlock(&fib6_walker_lock);
1266
1267 node_free(fn);
1268 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
1269 return pn;
1270
1271 rt6_release(pn->leaf);
1272 pn->leaf = NULL;
1273 fn = pn;
1274 }
1275 }
1276
1277 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
1278 struct nl_info *info)
1279 {
1280 struct fib6_walker_t *w;
1281 struct rt6_info *rt = *rtp;
1282 struct net *net = info->nl_net;
1283
1284 RT6_TRACE("fib6_del_route\n");
1285
1286 /* Unlink it */
1287 *rtp = rt->dst.rt6_next;
1288 rt->rt6i_node = NULL;
1289 net->ipv6.rt6_stats->fib_rt_entries--;
1290 net->ipv6.rt6_stats->fib_discarded_routes++;
1291
1292 /* Reset round-robin state, if necessary */
1293 if (fn->rr_ptr == rt)
1294 fn->rr_ptr = NULL;
1295
1296 /* Remove this entry from other siblings */
1297 if (rt->rt6i_nsiblings) {
1298 struct rt6_info *sibling, *next_sibling;
1299
1300 list_for_each_entry_safe(sibling, next_sibling,
1301 &rt->rt6i_siblings, rt6i_siblings)
1302 sibling->rt6i_nsiblings--;
1303 rt->rt6i_nsiblings = 0;
1304 list_del_init(&rt->rt6i_siblings);
1305 }
1306
1307 /* Adjust walkers */
1308 read_lock(&fib6_walker_lock);
1309 FOR_WALKERS(w) {
1310 if (w->state == FWS_C && w->leaf == rt) {
1311 RT6_TRACE("walker %p adjusted by delroute\n", w);
1312 w->leaf = rt->dst.rt6_next;
1313 if (!w->leaf)
1314 w->state = FWS_U;
1315 }
1316 }
1317 read_unlock(&fib6_walker_lock);
1318
1319 rt->dst.rt6_next = NULL;
1320
1321 /* If it was last route, expunge its radix tree node */
1322 if (!fn->leaf) {
1323 fn->fn_flags &= ~RTN_RTINFO;
1324 net->ipv6.rt6_stats->fib_route_nodes--;
1325 fn = fib6_repair_tree(net, fn);
1326 }
1327
1328 if (atomic_read(&rt->rt6i_ref) != 1) {
1329 /* This route is used as dummy address holder in some split
1330 * nodes. It is not leaked, but it still holds other resources,
1331 * which must be released in time. So, scan ascendant nodes
1332 * and replace dummy references to this route with references
1333 * to still alive ones.
1334 */
1335 while (fn) {
1336 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) {
1337 fn->leaf = fib6_find_prefix(net, fn);
1338 atomic_inc(&fn->leaf->rt6i_ref);
1339 rt6_release(rt);
1340 }
1341 fn = fn->parent;
1342 }
1343 /* No more references are possible at this point. */
1344 BUG_ON(atomic_read(&rt->rt6i_ref) != 1);
1345 }
1346
1347 inet6_rt_notify(RTM_DELROUTE, rt, info);
1348 rt6_release(rt);
1349 }
1350
1351 int fib6_del(struct rt6_info *rt, struct nl_info *info)
1352 {
1353 struct net *net = info->nl_net;
1354 struct fib6_node *fn = rt->rt6i_node;
1355 struct rt6_info **rtp;
1356
1357 #if RT6_DEBUG >= 2
1358 if (rt->dst.obsolete > 0) {
1359 WARN_ON(fn != NULL);
1360 return -ENOENT;
1361 }
1362 #endif
1363 if (!fn || rt == net->ipv6.ip6_null_entry)
1364 return -ENOENT;
1365
1366 WARN_ON(!(fn->fn_flags & RTN_RTINFO));
1367
1368 if (!(rt->rt6i_flags & RTF_CACHE)) {
1369 struct fib6_node *pn = fn;
1370 #ifdef CONFIG_IPV6_SUBTREES
1371 /* clones of this route might be in another subtree */
1372 if (rt->rt6i_src.plen) {
1373 while (!(pn->fn_flags & RTN_ROOT))
1374 pn = pn->parent;
1375 pn = pn->parent;
1376 }
1377 #endif
1378 fib6_prune_clones(info->nl_net, pn, rt);
1379 }
1380
1381 /*
1382 * Walk the leaf entries looking for ourself
1383 */
1384
1385 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) {
1386 if (*rtp == rt) {
1387 fib6_del_route(fn, rtp, info);
1388 return 0;
1389 }
1390 }
1391 return -ENOENT;
1392 }
1393
1394 /*
1395 * Tree traversal function.
1396 *
1397 * Certainly, it is not interrupt safe.
1398 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1399 * It means, that we can modify tree during walking
1400 * and use this function for garbage collection, clone pruning,
1401 * cleaning tree when a device goes down etc. etc.
1402 *
1403 * It guarantees that every node will be traversed,
1404 * and that it will be traversed only once.
1405 *
1406 * Callback function w->func may return:
1407 * 0 -> continue walking.
1408 * positive value -> walking is suspended (used by tree dumps,
1409 * and probably by gc, if it will be split to several slices)
1410 * negative value -> terminate walking.
1411 *
1412 * The function itself returns:
1413 * 0 -> walk is complete.
1414 * >0 -> walk is incomplete (i.e. suspended)
1415 * <0 -> walk is terminated by an error.
1416 */
1417
1418 static int fib6_walk_continue(struct fib6_walker_t *w)
1419 {
1420 struct fib6_node *fn, *pn;
1421
1422 for (;;) {
1423 fn = w->node;
1424 if (!fn)
1425 return 0;
1426
1427 if (w->prune && fn != w->root &&
1428 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) {
1429 w->state = FWS_C;
1430 w->leaf = fn->leaf;
1431 }
1432 switch (w->state) {
1433 #ifdef CONFIG_IPV6_SUBTREES
1434 case FWS_S:
1435 if (FIB6_SUBTREE(fn)) {
1436 w->node = FIB6_SUBTREE(fn);
1437 continue;
1438 }
1439 w->state = FWS_L;
1440 #endif
1441 case FWS_L:
1442 if (fn->left) {
1443 w->node = fn->left;
1444 w->state = FWS_INIT;
1445 continue;
1446 }
1447 w->state = FWS_R;
1448 case FWS_R:
1449 if (fn->right) {
1450 w->node = fn->right;
1451 w->state = FWS_INIT;
1452 continue;
1453 }
1454 w->state = FWS_C;
1455 w->leaf = fn->leaf;
1456 case FWS_C:
1457 if (w->leaf && fn->fn_flags & RTN_RTINFO) {
1458 int err;
1459
1460 if (w->skip) {
1461 w->skip--;
1462 goto skip;
1463 }
1464
1465 err = w->func(w);
1466 if (err)
1467 return err;
1468
1469 w->count++;
1470 continue;
1471 }
1472 skip:
1473 w->state = FWS_U;
1474 case FWS_U:
1475 if (fn == w->root)
1476 return 0;
1477 pn = fn->parent;
1478 w->node = pn;
1479 #ifdef CONFIG_IPV6_SUBTREES
1480 if (FIB6_SUBTREE(pn) == fn) {
1481 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1482 w->state = FWS_L;
1483 continue;
1484 }
1485 #endif
1486 if (pn->left == fn) {
1487 w->state = FWS_R;
1488 continue;
1489 }
1490 if (pn->right == fn) {
1491 w->state = FWS_C;
1492 w->leaf = w->node->leaf;
1493 continue;
1494 }
1495 #if RT6_DEBUG >= 2
1496 WARN_ON(1);
1497 #endif
1498 }
1499 }
1500 }
1501
1502 static int fib6_walk(struct fib6_walker_t *w)
1503 {
1504 int res;
1505
1506 w->state = FWS_INIT;
1507 w->node = w->root;
1508
1509 fib6_walker_link(w);
1510 res = fib6_walk_continue(w);
1511 if (res <= 0)
1512 fib6_walker_unlink(w);
1513 return res;
1514 }
1515
1516 static int fib6_clean_node(struct fib6_walker_t *w)
1517 {
1518 int res;
1519 struct rt6_info *rt;
1520 struct fib6_cleaner_t *c = container_of(w, struct fib6_cleaner_t, w);
1521 struct nl_info info = {
1522 .nl_net = c->net,
1523 };
1524
1525 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
1526 res = c->func(rt, c->arg);
1527 if (res < 0) {
1528 w->leaf = rt;
1529 res = fib6_del(rt, &info);
1530 if (res) {
1531 #if RT6_DEBUG >= 2
1532 pr_debug("%s: del failed: rt=%p@%p err=%d\n",
1533 __func__, rt, rt->rt6i_node, res);
1534 #endif
1535 continue;
1536 }
1537 return 0;
1538 }
1539 WARN_ON(res != 0);
1540 }
1541 w->leaf = rt;
1542 return 0;
1543 }
1544
1545 /*
1546 * Convenient frontend to tree walker.
1547 *
1548 * func is called on each route.
1549 * It may return -1 -> delete this route.
1550 * 0 -> continue walking
1551 *
1552 * prune==1 -> only immediate children of node (certainly,
1553 * ignoring pure split nodes) will be scanned.
1554 */
1555
1556 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1557 int (*func)(struct rt6_info *, void *arg),
1558 int prune, void *arg)
1559 {
1560 struct fib6_cleaner_t c;
1561
1562 c.w.root = root;
1563 c.w.func = fib6_clean_node;
1564 c.w.prune = prune;
1565 c.w.count = 0;
1566 c.w.skip = 0;
1567 c.func = func;
1568 c.arg = arg;
1569 c.net = net;
1570
1571 fib6_walk(&c.w);
1572 }
1573
1574 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
1575 void *arg)
1576 {
1577 struct fib6_table *table;
1578 struct hlist_head *head;
1579 unsigned int h;
1580
1581 rcu_read_lock();
1582 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
1583 head = &net->ipv6.fib_table_hash[h];
1584 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
1585 write_lock_bh(&table->tb6_lock);
1586 fib6_clean_tree(net, &table->tb6_root,
1587 func, 0, arg);
1588 write_unlock_bh(&table->tb6_lock);
1589 }
1590 }
1591 rcu_read_unlock();
1592 }
1593
1594 static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1595 {
1596 if (rt->rt6i_flags & RTF_CACHE) {
1597 RT6_TRACE("pruning clone %p\n", rt);
1598 return -1;
1599 }
1600
1601 return 0;
1602 }
1603
1604 static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
1605 struct rt6_info *rt)
1606 {
1607 fib6_clean_tree(net, fn, fib6_prune_clone, 1, rt);
1608 }
1609
1610 /*
1611 * Garbage collection
1612 */
1613
1614 static struct fib6_gc_args
1615 {
1616 int timeout;
1617 int more;
1618 } gc_args;
1619
1620 static int fib6_age(struct rt6_info *rt, void *arg)
1621 {
1622 unsigned long now = jiffies;
1623
1624 /*
1625 * check addrconf expiration here.
1626 * Routes are expired even if they are in use.
1627 *
1628 * Also age clones. Note, that clones are aged out
1629 * only if they are not in use now.
1630 */
1631
1632 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) {
1633 if (time_after(now, rt->dst.expires)) {
1634 RT6_TRACE("expiring %p\n", rt);
1635 return -1;
1636 }
1637 gc_args.more++;
1638 } else if (rt->rt6i_flags & RTF_CACHE) {
1639 if (atomic_read(&rt->dst.__refcnt) == 0 &&
1640 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) {
1641 RT6_TRACE("aging clone %p\n", rt);
1642 return -1;
1643 } else if (rt->rt6i_flags & RTF_GATEWAY) {
1644 struct neighbour *neigh;
1645 __u8 neigh_flags = 0;
1646
1647 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway);
1648 if (neigh) {
1649 neigh_flags = neigh->flags;
1650 neigh_release(neigh);
1651 }
1652 if (!(neigh_flags & NTF_ROUTER)) {
1653 RT6_TRACE("purging route %p via non-router but gateway\n",
1654 rt);
1655 return -1;
1656 }
1657 }
1658 gc_args.more++;
1659 }
1660
1661 return 0;
1662 }
1663
1664 static DEFINE_SPINLOCK(fib6_gc_lock);
1665
1666 void fib6_run_gc(unsigned long expires, struct net *net, bool force)
1667 {
1668 unsigned long now;
1669
1670 if (force) {
1671 spin_lock_bh(&fib6_gc_lock);
1672 } else if (!spin_trylock_bh(&fib6_gc_lock)) {
1673 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
1674 return;
1675 }
1676 gc_args.timeout = expires ? (int)expires :
1677 net->ipv6.sysctl.ip6_rt_gc_interval;
1678
1679 gc_args.more = icmp6_dst_gc();
1680
1681 fib6_clean_all(net, fib6_age, NULL);
1682 now = jiffies;
1683 net->ipv6.ip6_rt_last_gc = now;
1684
1685 if (gc_args.more)
1686 mod_timer(&net->ipv6.ip6_fib_timer,
1687 round_jiffies(now
1688 + net->ipv6.sysctl.ip6_rt_gc_interval));
1689 else
1690 del_timer(&net->ipv6.ip6_fib_timer);
1691 spin_unlock_bh(&fib6_gc_lock);
1692 }
1693
1694 static void fib6_gc_timer_cb(unsigned long arg)
1695 {
1696 fib6_run_gc(0, (struct net *)arg, true);
1697 }
1698
1699 static int __net_init fib6_net_init(struct net *net)
1700 {
1701 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
1702
1703 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
1704
1705 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
1706 if (!net->ipv6.rt6_stats)
1707 goto out_timer;
1708
1709 /* Avoid false sharing : Use at least a full cache line */
1710 size = max_t(size_t, size, L1_CACHE_BYTES);
1711
1712 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
1713 if (!net->ipv6.fib_table_hash)
1714 goto out_rt6_stats;
1715
1716 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
1717 GFP_KERNEL);
1718 if (!net->ipv6.fib6_main_tbl)
1719 goto out_fib_table_hash;
1720
1721 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
1722 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1723 net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
1724 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1725 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
1726
1727 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1728 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
1729 GFP_KERNEL);
1730 if (!net->ipv6.fib6_local_tbl)
1731 goto out_fib6_main_tbl;
1732 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
1733 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1734 net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
1735 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1736 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
1737 #endif
1738 fib6_tables_init(net);
1739
1740 return 0;
1741
1742 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1743 out_fib6_main_tbl:
1744 kfree(net->ipv6.fib6_main_tbl);
1745 #endif
1746 out_fib_table_hash:
1747 kfree(net->ipv6.fib_table_hash);
1748 out_rt6_stats:
1749 kfree(net->ipv6.rt6_stats);
1750 out_timer:
1751 return -ENOMEM;
1752 }
1753
1754 static void fib6_net_exit(struct net *net)
1755 {
1756 rt6_ifdown(net, NULL);
1757 del_timer_sync(&net->ipv6.ip6_fib_timer);
1758
1759 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1760 inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers);
1761 kfree(net->ipv6.fib6_local_tbl);
1762 #endif
1763 inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers);
1764 kfree(net->ipv6.fib6_main_tbl);
1765 kfree(net->ipv6.fib_table_hash);
1766 kfree(net->ipv6.rt6_stats);
1767 }
1768
1769 static struct pernet_operations fib6_net_ops = {
1770 .init = fib6_net_init,
1771 .exit = fib6_net_exit,
1772 };
1773
1774 int __init fib6_init(void)
1775 {
1776 int ret = -ENOMEM;
1777
1778 fib6_node_kmem = kmem_cache_create("fib6_nodes",
1779 sizeof(struct fib6_node),
1780 0, SLAB_HWCACHE_ALIGN,
1781 NULL);
1782 if (!fib6_node_kmem)
1783 goto out;
1784
1785 ret = register_pernet_subsys(&fib6_net_ops);
1786 if (ret)
1787 goto out_kmem_cache_create;
1788
1789 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib,
1790 NULL);
1791 if (ret)
1792 goto out_unregister_subsys;
1793 out:
1794 return ret;
1795
1796 out_unregister_subsys:
1797 unregister_pernet_subsys(&fib6_net_ops);
1798 out_kmem_cache_create:
1799 kmem_cache_destroy(fib6_node_kmem);
1800 goto out;
1801 }
1802
1803 void fib6_gc_cleanup(void)
1804 {
1805 unregister_pernet_subsys(&fib6_net_ops);
1806 kmem_cache_destroy(fib6_node_kmem);
1807 }
1808
1809 #ifdef CONFIG_PROC_FS
1810
1811 struct ipv6_route_iter {
1812 struct seq_net_private p;
1813 struct fib6_walker_t w;
1814 loff_t skip;
1815 struct fib6_table *tbl;
1816 __u32 sernum;
1817 };
1818
1819 static int ipv6_route_seq_show(struct seq_file *seq, void *v)
1820 {
1821 struct rt6_info *rt = v;
1822 struct ipv6_route_iter *iter = seq->private;
1823
1824 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen);
1825
1826 #ifdef CONFIG_IPV6_SUBTREES
1827 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen);
1828 #else
1829 seq_puts(seq, "00000000000000000000000000000000 00 ");
1830 #endif
1831 if (rt->rt6i_flags & RTF_GATEWAY)
1832 seq_printf(seq, "%pi6", &rt->rt6i_gateway);
1833 else
1834 seq_puts(seq, "00000000000000000000000000000000");
1835
1836 seq_printf(seq, " %08x %08x %08x %08x %8s\n",
1837 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt),
1838 rt->dst.__use, rt->rt6i_flags,
1839 rt->dst.dev ? rt->dst.dev->name : "");
1840 iter->w.leaf = NULL;
1841 return 0;
1842 }
1843
1844 static int ipv6_route_yield(struct fib6_walker_t *w)
1845 {
1846 struct ipv6_route_iter *iter = w->args;
1847
1848 if (!iter->skip)
1849 return 1;
1850
1851 do {
1852 iter->w.leaf = iter->w.leaf->dst.rt6_next;
1853 iter->skip--;
1854 if (!iter->skip && iter->w.leaf)
1855 return 1;
1856 } while (iter->w.leaf);
1857
1858 return 0;
1859 }
1860
1861 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter)
1862 {
1863 memset(&iter->w, 0, sizeof(iter->w));
1864 iter->w.func = ipv6_route_yield;
1865 iter->w.root = &iter->tbl->tb6_root;
1866 iter->w.state = FWS_INIT;
1867 iter->w.node = iter->w.root;
1868 iter->w.args = iter;
1869 iter->sernum = iter->w.root->fn_sernum;
1870 INIT_LIST_HEAD(&iter->w.lh);
1871 fib6_walker_link(&iter->w);
1872 }
1873
1874 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
1875 struct net *net)
1876 {
1877 unsigned int h;
1878 struct hlist_node *node;
1879
1880 if (tbl) {
1881 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1;
1882 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist));
1883 } else {
1884 h = 0;
1885 node = NULL;
1886 }
1887
1888 while (!node && h < FIB6_TABLE_HASHSZ) {
1889 node = rcu_dereference_bh(
1890 hlist_first_rcu(&net->ipv6.fib_table_hash[h++]));
1891 }
1892 return hlist_entry_safe(node, struct fib6_table, tb6_hlist);
1893 }
1894
1895 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter)
1896 {
1897 if (iter->sernum != iter->w.root->fn_sernum) {
1898 iter->sernum = iter->w.root->fn_sernum;
1899 iter->w.state = FWS_INIT;
1900 iter->w.node = iter->w.root;
1901 WARN_ON(iter->w.skip);
1902 iter->w.skip = iter->w.count;
1903 }
1904 }
1905
1906 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1907 {
1908 int r;
1909 struct rt6_info *n;
1910 struct net *net = seq_file_net(seq);
1911 struct ipv6_route_iter *iter = seq->private;
1912
1913 if (!v)
1914 goto iter_table;
1915
1916 n = ((struct rt6_info *)v)->dst.rt6_next;
1917 if (n) {
1918 ++*pos;
1919 return n;
1920 }
1921
1922 iter_table:
1923 ipv6_route_check_sernum(iter);
1924 read_lock(&iter->tbl->tb6_lock);
1925 r = fib6_walk_continue(&iter->w);
1926 read_unlock(&iter->tbl->tb6_lock);
1927 if (r > 0) {
1928 if (v)
1929 ++*pos;
1930 return iter->w.leaf;
1931 } else if (r < 0) {
1932 fib6_walker_unlink(&iter->w);
1933 return NULL;
1934 }
1935 fib6_walker_unlink(&iter->w);
1936
1937 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
1938 if (!iter->tbl)
1939 return NULL;
1940
1941 ipv6_route_seq_setup_walk(iter);
1942 goto iter_table;
1943 }
1944
1945 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
1946 __acquires(RCU_BH)
1947 {
1948 struct net *net = seq_file_net(seq);
1949 struct ipv6_route_iter *iter = seq->private;
1950
1951 rcu_read_lock_bh();
1952 iter->tbl = ipv6_route_seq_next_table(NULL, net);
1953 iter->skip = *pos;
1954
1955 if (iter->tbl) {
1956 ipv6_route_seq_setup_walk(iter);
1957 return ipv6_route_seq_next(seq, NULL, pos);
1958 } else {
1959 return NULL;
1960 }
1961 }
1962
1963 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter)
1964 {
1965 struct fib6_walker_t *w = &iter->w;
1966 return w->node && !(w->state == FWS_U && w->node == w->root);
1967 }
1968
1969 static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
1970 __releases(RCU_BH)
1971 {
1972 struct ipv6_route_iter *iter = seq->private;
1973
1974 if (ipv6_route_iter_active(iter))
1975 fib6_walker_unlink(&iter->w);
1976
1977 rcu_read_unlock_bh();
1978 }
1979
1980 static const struct seq_operations ipv6_route_seq_ops = {
1981 .start = ipv6_route_seq_start,
1982 .next = ipv6_route_seq_next,
1983 .stop = ipv6_route_seq_stop,
1984 .show = ipv6_route_seq_show
1985 };
1986
1987 int ipv6_route_open(struct inode *inode, struct file *file)
1988 {
1989 return seq_open_net(inode, file, &ipv6_route_seq_ops,
1990 sizeof(struct ipv6_route_iter));
1991 }
1992
1993 #endif /* CONFIG_PROC_FS */
Linux kernel - Deliverables
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