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55d19861ab20f4a91b6b289be7ca3b0250df4531
[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 struct fib6_cleaner {
50 struct fib6_walker w;
51 struct net *net;
52 int (*func)(struct rt6_info *, void *arg);
53 int sernum;
54 void *arg;
55 };
56
57 static DEFINE_RWLOCK(fib6_walker_lock);
58
59 #ifdef CONFIG_IPV6_SUBTREES
60 #define FWS_INIT FWS_S
61 #else
62 #define FWS_INIT FWS_L
63 #endif
64
65 static void fib6_prune_clones(struct net *net, struct fib6_node *fn);
66 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn);
67 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn);
68 static int fib6_walk(struct fib6_walker *w);
69 static int fib6_walk_continue(struct fib6_walker *w);
70
71 /*
72 * A routing update causes an increase of the serial number on the
73 * affected subtree. This allows for cached routes to be asynchronously
74 * tested when modifications are made to the destination cache as a
75 * result of redirects, path MTU changes, etc.
76 */
77
78 static void fib6_gc_timer_cb(unsigned long arg);
79
80 static LIST_HEAD(fib6_walkers);
81 #define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh)
82
83 static void fib6_walker_link(struct fib6_walker *w)
84 {
85 write_lock_bh(&fib6_walker_lock);
86 list_add(&w->lh, &fib6_walkers);
87 write_unlock_bh(&fib6_walker_lock);
88 }
89
90 static void fib6_walker_unlink(struct fib6_walker *w)
91 {
92 write_lock_bh(&fib6_walker_lock);
93 list_del(&w->lh);
94 write_unlock_bh(&fib6_walker_lock);
95 }
96
97 static int fib6_new_sernum(struct net *net)
98 {
99 int new, old;
100
101 do {
102 old = atomic_read(&net->ipv6.fib6_sernum);
103 new = old < INT_MAX ? old + 1 : 1;
104 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum,
105 old, new) != old);
106 return new;
107 }
108
109 enum {
110 FIB6_NO_SERNUM_CHANGE = 0,
111 };
112
113 /*
114 * Auxiliary address test functions for the radix tree.
115 *
116 * These assume a 32bit processor (although it will work on
117 * 64bit processors)
118 */
119
120 /*
121 * test bit
122 */
123 #if defined(__LITTLE_ENDIAN)
124 # define BITOP_BE32_SWIZZLE (0x1F & ~7)
125 #else
126 # define BITOP_BE32_SWIZZLE 0
127 #endif
128
129 static __be32 addr_bit_set(const void *token, int fn_bit)
130 {
131 const __be32 *addr = token;
132 /*
133 * Here,
134 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
135 * is optimized version of
136 * htonl(1 << ((~fn_bit)&0x1F))
137 * See include/asm-generic/bitops/le.h.
138 */
139 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
140 addr[fn_bit >> 5];
141 }
142
143 static struct fib6_node *node_alloc(void)
144 {
145 struct fib6_node *fn;
146
147 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
148
149 return fn;
150 }
151
152 static void node_free(struct fib6_node *fn)
153 {
154 kmem_cache_free(fib6_node_kmem, fn);
155 }
156
157 static void rt6_free_pcpu(struct rt6_info *non_pcpu_rt)
158 {
159 int cpu;
160
161 if (!non_pcpu_rt->rt6i_pcpu)
162 return;
163
164 for_each_possible_cpu(cpu) {
165 struct rt6_info **ppcpu_rt;
166 struct rt6_info *pcpu_rt;
167
168 ppcpu_rt = per_cpu_ptr(non_pcpu_rt->rt6i_pcpu, cpu);
169 pcpu_rt = *ppcpu_rt;
170 if (pcpu_rt) {
171 dst_free(&pcpu_rt->dst);
172 *ppcpu_rt = NULL;
173 }
174 }
175 }
176
177 static void rt6_release(struct rt6_info *rt)
178 {
179 if (atomic_dec_and_test(&rt->rt6i_ref)) {
180 rt6_free_pcpu(rt);
181 dst_free(&rt->dst);
182 }
183 }
184
185 static void fib6_link_table(struct net *net, struct fib6_table *tb)
186 {
187 unsigned int h;
188
189 /*
190 * Initialize table lock at a single place to give lockdep a key,
191 * tables aren't visible prior to being linked to the list.
192 */
193 rwlock_init(&tb->tb6_lock);
194
195 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
196
197 /*
198 * No protection necessary, this is the only list mutatation
199 * operation, tables never disappear once they exist.
200 */
201 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
202 }
203
204 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
205
206 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
207 {
208 struct fib6_table *table;
209
210 table = kzalloc(sizeof(*table), GFP_ATOMIC);
211 if (table) {
212 table->tb6_id = id;
213 table->tb6_root.leaf = net->ipv6.ip6_null_entry;
214 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
215 inet_peer_base_init(&table->tb6_peers);
216 }
217
218 return table;
219 }
220
221 struct fib6_table *fib6_new_table(struct net *net, u32 id)
222 {
223 struct fib6_table *tb;
224
225 if (id == 0)
226 id = RT6_TABLE_MAIN;
227 tb = fib6_get_table(net, id);
228 if (tb)
229 return tb;
230
231 tb = fib6_alloc_table(net, id);
232 if (tb)
233 fib6_link_table(net, tb);
234
235 return tb;
236 }
237
238 struct fib6_table *fib6_get_table(struct net *net, u32 id)
239 {
240 struct fib6_table *tb;
241 struct hlist_head *head;
242 unsigned int h;
243
244 if (id == 0)
245 id = RT6_TABLE_MAIN;
246 h = id & (FIB6_TABLE_HASHSZ - 1);
247 rcu_read_lock();
248 head = &net->ipv6.fib_table_hash[h];
249 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
250 if (tb->tb6_id == id) {
251 rcu_read_unlock();
252 return tb;
253 }
254 }
255 rcu_read_unlock();
256
257 return NULL;
258 }
259
260 static void __net_init fib6_tables_init(struct net *net)
261 {
262 fib6_link_table(net, net->ipv6.fib6_main_tbl);
263 fib6_link_table(net, net->ipv6.fib6_local_tbl);
264 }
265 #else
266
267 struct fib6_table *fib6_new_table(struct net *net, u32 id)
268 {
269 return fib6_get_table(net, id);
270 }
271
272 struct fib6_table *fib6_get_table(struct net *net, u32 id)
273 {
274 return net->ipv6.fib6_main_tbl;
275 }
276
277 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
278 int flags, pol_lookup_t lookup)
279 {
280 return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl6, flags);
281 }
282
283 static void __net_init fib6_tables_init(struct net *net)
284 {
285 fib6_link_table(net, net->ipv6.fib6_main_tbl);
286 }
287
288 #endif
289
290 static int fib6_dump_node(struct fib6_walker *w)
291 {
292 int res;
293 struct rt6_info *rt;
294
295 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
296 res = rt6_dump_route(rt, w->args);
297 if (res < 0) {
298 /* Frame is full, suspend walking */
299 w->leaf = rt;
300 return 1;
301 }
302 }
303 w->leaf = NULL;
304 return 0;
305 }
306
307 static void fib6_dump_end(struct netlink_callback *cb)
308 {
309 struct fib6_walker *w = (void *)cb->args[2];
310
311 if (w) {
312 if (cb->args[4]) {
313 cb->args[4] = 0;
314 fib6_walker_unlink(w);
315 }
316 cb->args[2] = 0;
317 kfree(w);
318 }
319 cb->done = (void *)cb->args[3];
320 cb->args[1] = 3;
321 }
322
323 static int fib6_dump_done(struct netlink_callback *cb)
324 {
325 fib6_dump_end(cb);
326 return cb->done ? cb->done(cb) : 0;
327 }
328
329 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
330 struct netlink_callback *cb)
331 {
332 struct fib6_walker *w;
333 int res;
334
335 w = (void *)cb->args[2];
336 w->root = &table->tb6_root;
337
338 if (cb->args[4] == 0) {
339 w->count = 0;
340 w->skip = 0;
341
342 read_lock_bh(&table->tb6_lock);
343 res = fib6_walk(w);
344 read_unlock_bh(&table->tb6_lock);
345 if (res > 0) {
346 cb->args[4] = 1;
347 cb->args[5] = w->root->fn_sernum;
348 }
349 } else {
350 if (cb->args[5] != w->root->fn_sernum) {
351 /* Begin at the root if the tree changed */
352 cb->args[5] = w->root->fn_sernum;
353 w->state = FWS_INIT;
354 w->node = w->root;
355 w->skip = w->count;
356 } else
357 w->skip = 0;
358
359 read_lock_bh(&table->tb6_lock);
360 res = fib6_walk_continue(w);
361 read_unlock_bh(&table->tb6_lock);
362 if (res <= 0) {
363 fib6_walker_unlink(w);
364 cb->args[4] = 0;
365 }
366 }
367
368 return res;
369 }
370
371 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
372 {
373 struct net *net = sock_net(skb->sk);
374 unsigned int h, s_h;
375 unsigned int e = 0, s_e;
376 struct rt6_rtnl_dump_arg arg;
377 struct fib6_walker *w;
378 struct fib6_table *tb;
379 struct hlist_head *head;
380 int res = 0;
381
382 s_h = cb->args[0];
383 s_e = cb->args[1];
384
385 w = (void *)cb->args[2];
386 if (!w) {
387 /* New dump:
388 *
389 * 1. hook callback destructor.
390 */
391 cb->args[3] = (long)cb->done;
392 cb->done = fib6_dump_done;
393
394 /*
395 * 2. allocate and initialize walker.
396 */
397 w = kzalloc(sizeof(*w), GFP_ATOMIC);
398 if (!w)
399 return -ENOMEM;
400 w->func = fib6_dump_node;
401 cb->args[2] = (long)w;
402 }
403
404 arg.skb = skb;
405 arg.cb = cb;
406 arg.net = net;
407 w->args = &arg;
408
409 rcu_read_lock();
410 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
411 e = 0;
412 head = &net->ipv6.fib_table_hash[h];
413 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
414 if (e < s_e)
415 goto next;
416 res = fib6_dump_table(tb, skb, cb);
417 if (res != 0)
418 goto out;
419 next:
420 e++;
421 }
422 }
423 out:
424 rcu_read_unlock();
425 cb->args[1] = e;
426 cb->args[0] = h;
427
428 res = res < 0 ? res : skb->len;
429 if (res <= 0)
430 fib6_dump_end(cb);
431 return res;
432 }
433
434 /*
435 * Routing Table
436 *
437 * return the appropriate node for a routing tree "add" operation
438 * by either creating and inserting or by returning an existing
439 * node.
440 */
441
442 static struct fib6_node *fib6_add_1(struct fib6_node *root,
443 struct in6_addr *addr, int plen,
444 int offset, int allow_create,
445 int replace_required, int sernum)
446 {
447 struct fib6_node *fn, *in, *ln;
448 struct fib6_node *pn = NULL;
449 struct rt6key *key;
450 int bit;
451 __be32 dir = 0;
452
453 RT6_TRACE("fib6_add_1\n");
454
455 /* insert node in tree */
456
457 fn = root;
458
459 do {
460 key = (struct rt6key *)((u8 *)fn->leaf + offset);
461
462 /*
463 * Prefix match
464 */
465 if (plen < fn->fn_bit ||
466 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
467 if (!allow_create) {
468 if (replace_required) {
469 pr_warn("Can't replace route, no match found\n");
470 return ERR_PTR(-ENOENT);
471 }
472 pr_warn("NLM_F_CREATE should be set when creating new route\n");
473 }
474 goto insert_above;
475 }
476
477 /*
478 * Exact match ?
479 */
480
481 if (plen == fn->fn_bit) {
482 /* clean up an intermediate node */
483 if (!(fn->fn_flags & RTN_RTINFO)) {
484 rt6_release(fn->leaf);
485 fn->leaf = NULL;
486 }
487
488 fn->fn_sernum = sernum;
489
490 return fn;
491 }
492
493 /*
494 * We have more bits to go
495 */
496
497 /* Try to walk down on tree. */
498 fn->fn_sernum = sernum;
499 dir = addr_bit_set(addr, fn->fn_bit);
500 pn = fn;
501 fn = dir ? fn->right : fn->left;
502 } while (fn);
503
504 if (!allow_create) {
505 /* We should not create new node because
506 * NLM_F_REPLACE was specified without NLM_F_CREATE
507 * I assume it is safe to require NLM_F_CREATE when
508 * REPLACE flag is used! Later we may want to remove the
509 * check for replace_required, because according
510 * to netlink specification, NLM_F_CREATE
511 * MUST be specified if new route is created.
512 * That would keep IPv6 consistent with IPv4
513 */
514 if (replace_required) {
515 pr_warn("Can't replace route, no match found\n");
516 return ERR_PTR(-ENOENT);
517 }
518 pr_warn("NLM_F_CREATE should be set when creating new route\n");
519 }
520 /*
521 * We walked to the bottom of tree.
522 * Create new leaf node without children.
523 */
524
525 ln = node_alloc();
526
527 if (!ln)
528 return ERR_PTR(-ENOMEM);
529 ln->fn_bit = plen;
530
531 ln->parent = pn;
532 ln->fn_sernum = sernum;
533
534 if (dir)
535 pn->right = ln;
536 else
537 pn->left = ln;
538
539 return ln;
540
541
542 insert_above:
543 /*
544 * split since we don't have a common prefix anymore or
545 * we have a less significant route.
546 * we've to insert an intermediate node on the list
547 * this new node will point to the one we need to create
548 * and the current
549 */
550
551 pn = fn->parent;
552
553 /* find 1st bit in difference between the 2 addrs.
554
555 See comment in __ipv6_addr_diff: bit may be an invalid value,
556 but if it is >= plen, the value is ignored in any case.
557 */
558
559 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr));
560
561 /*
562 * (intermediate)[in]
563 * / \
564 * (new leaf node)[ln] (old node)[fn]
565 */
566 if (plen > bit) {
567 in = node_alloc();
568 ln = node_alloc();
569
570 if (!in || !ln) {
571 if (in)
572 node_free(in);
573 if (ln)
574 node_free(ln);
575 return ERR_PTR(-ENOMEM);
576 }
577
578 /*
579 * new intermediate node.
580 * RTN_RTINFO will
581 * be off since that an address that chooses one of
582 * the branches would not match less specific routes
583 * in the other branch
584 */
585
586 in->fn_bit = bit;
587
588 in->parent = pn;
589 in->leaf = fn->leaf;
590 atomic_inc(&in->leaf->rt6i_ref);
591
592 in->fn_sernum = sernum;
593
594 /* update parent pointer */
595 if (dir)
596 pn->right = in;
597 else
598 pn->left = in;
599
600 ln->fn_bit = plen;
601
602 ln->parent = in;
603 fn->parent = in;
604
605 ln->fn_sernum = sernum;
606
607 if (addr_bit_set(addr, bit)) {
608 in->right = ln;
609 in->left = fn;
610 } else {
611 in->left = ln;
612 in->right = fn;
613 }
614 } else { /* plen <= bit */
615
616 /*
617 * (new leaf node)[ln]
618 * / \
619 * (old node)[fn] NULL
620 */
621
622 ln = node_alloc();
623
624 if (!ln)
625 return ERR_PTR(-ENOMEM);
626
627 ln->fn_bit = plen;
628
629 ln->parent = pn;
630
631 ln->fn_sernum = sernum;
632
633 if (dir)
634 pn->right = ln;
635 else
636 pn->left = ln;
637
638 if (addr_bit_set(&key->addr, plen))
639 ln->right = fn;
640 else
641 ln->left = fn;
642
643 fn->parent = ln;
644 }
645 return ln;
646 }
647
648 static bool rt6_qualify_for_ecmp(struct rt6_info *rt)
649 {
650 return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) ==
651 RTF_GATEWAY;
652 }
653
654 static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc)
655 {
656 int i;
657
658 for (i = 0; i < RTAX_MAX; i++) {
659 if (test_bit(i, mxc->mx_valid))
660 mp[i] = mxc->mx[i];
661 }
662 }
663
664 static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc)
665 {
666 if (!mxc->mx)
667 return 0;
668
669 if (dst->flags & DST_HOST) {
670 u32 *mp = dst_metrics_write_ptr(dst);
671
672 if (unlikely(!mp))
673 return -ENOMEM;
674
675 fib6_copy_metrics(mp, mxc);
676 } else {
677 dst_init_metrics(dst, mxc->mx, false);
678
679 /* We've stolen mx now. */
680 mxc->mx = NULL;
681 }
682
683 return 0;
684 }
685
686 static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn,
687 struct net *net)
688 {
689 if (atomic_read(&rt->rt6i_ref) != 1) {
690 /* This route is used as dummy address holder in some split
691 * nodes. It is not leaked, but it still holds other resources,
692 * which must be released in time. So, scan ascendant nodes
693 * and replace dummy references to this route with references
694 * to still alive ones.
695 */
696 while (fn) {
697 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) {
698 fn->leaf = fib6_find_prefix(net, fn);
699 atomic_inc(&fn->leaf->rt6i_ref);
700 rt6_release(rt);
701 }
702 fn = fn->parent;
703 }
704 /* No more references are possible at this point. */
705 BUG_ON(atomic_read(&rt->rt6i_ref) != 1);
706 }
707 }
708
709 /*
710 * Insert routing information in a node.
711 */
712
713 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
714 struct nl_info *info, struct mx6_config *mxc)
715 {
716 struct rt6_info *iter = NULL;
717 struct rt6_info **ins;
718 struct rt6_info **fallback_ins = NULL;
719 int replace = (info->nlh &&
720 (info->nlh->nlmsg_flags & NLM_F_REPLACE));
721 int add = (!info->nlh ||
722 (info->nlh->nlmsg_flags & NLM_F_CREATE));
723 int found = 0;
724 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
725 int err;
726
727 ins = &fn->leaf;
728
729 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) {
730 /*
731 * Search for duplicates
732 */
733
734 if (iter->rt6i_metric == rt->rt6i_metric) {
735 /*
736 * Same priority level
737 */
738 if (info->nlh &&
739 (info->nlh->nlmsg_flags & NLM_F_EXCL))
740 return -EEXIST;
741 if (replace) {
742 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) {
743 found++;
744 break;
745 }
746 if (rt_can_ecmp)
747 fallback_ins = fallback_ins ?: ins;
748 goto next_iter;
749 }
750
751 if (iter->dst.dev == rt->dst.dev &&
752 iter->rt6i_idev == rt->rt6i_idev &&
753 ipv6_addr_equal(&iter->rt6i_gateway,
754 &rt->rt6i_gateway)) {
755 if (rt->rt6i_nsiblings)
756 rt->rt6i_nsiblings = 0;
757 if (!(iter->rt6i_flags & RTF_EXPIRES))
758 return -EEXIST;
759 if (!(rt->rt6i_flags & RTF_EXPIRES))
760 rt6_clean_expires(iter);
761 else
762 rt6_set_expires(iter, rt->dst.expires);
763 iter->rt6i_pmtu = rt->rt6i_pmtu;
764 return -EEXIST;
765 }
766 /* If we have the same destination and the same metric,
767 * but not the same gateway, then the route we try to
768 * add is sibling to this route, increment our counter
769 * of siblings, and later we will add our route to the
770 * list.
771 * Only static routes (which don't have flag
772 * RTF_EXPIRES) are used for ECMPv6.
773 *
774 * To avoid long list, we only had siblings if the
775 * route have a gateway.
776 */
777 if (rt_can_ecmp &&
778 rt6_qualify_for_ecmp(iter))
779 rt->rt6i_nsiblings++;
780 }
781
782 if (iter->rt6i_metric > rt->rt6i_metric)
783 break;
784
785 next_iter:
786 ins = &iter->dst.rt6_next;
787 }
788
789 if (fallback_ins && !found) {
790 /* No ECMP-able route found, replace first non-ECMP one */
791 ins = fallback_ins;
792 iter = *ins;
793 found++;
794 }
795
796 /* Reset round-robin state, if necessary */
797 if (ins == &fn->leaf)
798 fn->rr_ptr = NULL;
799
800 /* Link this route to others same route. */
801 if (rt->rt6i_nsiblings) {
802 unsigned int rt6i_nsiblings;
803 struct rt6_info *sibling, *temp_sibling;
804
805 /* Find the first route that have the same metric */
806 sibling = fn->leaf;
807 while (sibling) {
808 if (sibling->rt6i_metric == rt->rt6i_metric &&
809 rt6_qualify_for_ecmp(sibling)) {
810 list_add_tail(&rt->rt6i_siblings,
811 &sibling->rt6i_siblings);
812 break;
813 }
814 sibling = sibling->dst.rt6_next;
815 }
816 /* For each sibling in the list, increment the counter of
817 * siblings. BUG() if counters does not match, list of siblings
818 * is broken!
819 */
820 rt6i_nsiblings = 0;
821 list_for_each_entry_safe(sibling, temp_sibling,
822 &rt->rt6i_siblings, rt6i_siblings) {
823 sibling->rt6i_nsiblings++;
824 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings);
825 rt6i_nsiblings++;
826 }
827 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings);
828 }
829
830 /*
831 * insert node
832 */
833 if (!replace) {
834 if (!add)
835 pr_warn("NLM_F_CREATE should be set when creating new route\n");
836
837 add:
838 err = fib6_commit_metrics(&rt->dst, mxc);
839 if (err)
840 return err;
841
842 rt->dst.rt6_next = iter;
843 *ins = rt;
844 rt->rt6i_node = fn;
845 atomic_inc(&rt->rt6i_ref);
846 inet6_rt_notify(RTM_NEWROUTE, rt, info);
847 info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
848
849 if (!(fn->fn_flags & RTN_RTINFO)) {
850 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
851 fn->fn_flags |= RTN_RTINFO;
852 }
853
854 } else {
855 int nsiblings;
856
857 if (!found) {
858 if (add)
859 goto add;
860 pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
861 return -ENOENT;
862 }
863
864 err = fib6_commit_metrics(&rt->dst, mxc);
865 if (err)
866 return err;
867
868 *ins = rt;
869 rt->rt6i_node = fn;
870 rt->dst.rt6_next = iter->dst.rt6_next;
871 atomic_inc(&rt->rt6i_ref);
872 inet6_rt_notify(RTM_NEWROUTE, rt, info);
873 if (!(fn->fn_flags & RTN_RTINFO)) {
874 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
875 fn->fn_flags |= RTN_RTINFO;
876 }
877 nsiblings = iter->rt6i_nsiblings;
878 fib6_purge_rt(iter, fn, info->nl_net);
879 rt6_release(iter);
880
881 if (nsiblings) {
882 /* Replacing an ECMP route, remove all siblings */
883 ins = &rt->dst.rt6_next;
884 iter = *ins;
885 while (iter) {
886 if (rt6_qualify_for_ecmp(iter)) {
887 *ins = iter->dst.rt6_next;
888 fib6_purge_rt(iter, fn, info->nl_net);
889 rt6_release(iter);
890 nsiblings--;
891 } else {
892 ins = &iter->dst.rt6_next;
893 }
894 iter = *ins;
895 }
896 WARN_ON(nsiblings != 0);
897 }
898 }
899
900 return 0;
901 }
902
903 static void fib6_start_gc(struct net *net, struct rt6_info *rt)
904 {
905 if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
906 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE)))
907 mod_timer(&net->ipv6.ip6_fib_timer,
908 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
909 }
910
911 void fib6_force_start_gc(struct net *net)
912 {
913 if (!timer_pending(&net->ipv6.ip6_fib_timer))
914 mod_timer(&net->ipv6.ip6_fib_timer,
915 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
916 }
917
918 /*
919 * Add routing information to the routing tree.
920 * <destination addr>/<source addr>
921 * with source addr info in sub-trees
922 */
923
924 int fib6_add(struct fib6_node *root, struct rt6_info *rt,
925 struct nl_info *info, struct mx6_config *mxc)
926 {
927 struct fib6_node *fn, *pn = NULL;
928 int err = -ENOMEM;
929 int allow_create = 1;
930 int replace_required = 0;
931 int sernum = fib6_new_sernum(info->nl_net);
932
933 if (info->nlh) {
934 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
935 allow_create = 0;
936 if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
937 replace_required = 1;
938 }
939 if (!allow_create && !replace_required)
940 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
941
942 fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
943 offsetof(struct rt6_info, rt6i_dst), allow_create,
944 replace_required, sernum);
945 if (IS_ERR(fn)) {
946 err = PTR_ERR(fn);
947 fn = NULL;
948 goto out;
949 }
950
951 pn = fn;
952
953 #ifdef CONFIG_IPV6_SUBTREES
954 if (rt->rt6i_src.plen) {
955 struct fib6_node *sn;
956
957 if (!fn->subtree) {
958 struct fib6_node *sfn;
959
960 /*
961 * Create subtree.
962 *
963 * fn[main tree]
964 * |
965 * sfn[subtree root]
966 * \
967 * sn[new leaf node]
968 */
969
970 /* Create subtree root node */
971 sfn = node_alloc();
972 if (!sfn)
973 goto st_failure;
974
975 sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
976 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
977 sfn->fn_flags = RTN_ROOT;
978 sfn->fn_sernum = sernum;
979
980 /* Now add the first leaf node to new subtree */
981
982 sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
983 rt->rt6i_src.plen,
984 offsetof(struct rt6_info, rt6i_src),
985 allow_create, replace_required, sernum);
986
987 if (IS_ERR(sn)) {
988 /* If it is failed, discard just allocated
989 root, and then (in st_failure) stale node
990 in main tree.
991 */
992 node_free(sfn);
993 err = PTR_ERR(sn);
994 goto st_failure;
995 }
996
997 /* Now link new subtree to main tree */
998 sfn->parent = fn;
999 fn->subtree = sfn;
1000 } else {
1001 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
1002 rt->rt6i_src.plen,
1003 offsetof(struct rt6_info, rt6i_src),
1004 allow_create, replace_required, sernum);
1005
1006 if (IS_ERR(sn)) {
1007 err = PTR_ERR(sn);
1008 goto st_failure;
1009 }
1010 }
1011
1012 if (!fn->leaf) {
1013 fn->leaf = rt;
1014 atomic_inc(&rt->rt6i_ref);
1015 }
1016 fn = sn;
1017 }
1018 #endif
1019
1020 err = fib6_add_rt2node(fn, rt, info, mxc);
1021 if (!err) {
1022 fib6_start_gc(info->nl_net, rt);
1023 if (!(rt->rt6i_flags & RTF_CACHE))
1024 fib6_prune_clones(info->nl_net, pn);
1025 }
1026
1027 out:
1028 if (err) {
1029 #ifdef CONFIG_IPV6_SUBTREES
1030 /*
1031 * If fib6_add_1 has cleared the old leaf pointer in the
1032 * super-tree leaf node we have to find a new one for it.
1033 */
1034 if (pn != fn && pn->leaf == rt) {
1035 pn->leaf = NULL;
1036 atomic_dec(&rt->rt6i_ref);
1037 }
1038 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
1039 pn->leaf = fib6_find_prefix(info->nl_net, pn);
1040 #if RT6_DEBUG >= 2
1041 if (!pn->leaf) {
1042 WARN_ON(pn->leaf == NULL);
1043 pn->leaf = info->nl_net->ipv6.ip6_null_entry;
1044 }
1045 #endif
1046 atomic_inc(&pn->leaf->rt6i_ref);
1047 }
1048 #endif
1049 dst_free(&rt->dst);
1050 }
1051 return err;
1052
1053 #ifdef CONFIG_IPV6_SUBTREES
1054 /* Subtree creation failed, probably main tree node
1055 is orphan. If it is, shoot it.
1056 */
1057 st_failure:
1058 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
1059 fib6_repair_tree(info->nl_net, fn);
1060 dst_free(&rt->dst);
1061 return err;
1062 #endif
1063 }
1064
1065 /*
1066 * Routing tree lookup
1067 *
1068 */
1069
1070 struct lookup_args {
1071 int offset; /* key offset on rt6_info */
1072 const struct in6_addr *addr; /* search key */
1073 };
1074
1075 static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
1076 struct lookup_args *args)
1077 {
1078 struct fib6_node *fn;
1079 __be32 dir;
1080
1081 if (unlikely(args->offset == 0))
1082 return NULL;
1083
1084 /*
1085 * Descend on a tree
1086 */
1087
1088 fn = root;
1089
1090 for (;;) {
1091 struct fib6_node *next;
1092
1093 dir = addr_bit_set(args->addr, fn->fn_bit);
1094
1095 next = dir ? fn->right : fn->left;
1096
1097 if (next) {
1098 fn = next;
1099 continue;
1100 }
1101 break;
1102 }
1103
1104 while (fn) {
1105 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
1106 struct rt6key *key;
1107
1108 key = (struct rt6key *) ((u8 *) fn->leaf +
1109 args->offset);
1110
1111 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
1112 #ifdef CONFIG_IPV6_SUBTREES
1113 if (fn->subtree) {
1114 struct fib6_node *sfn;
1115 sfn = fib6_lookup_1(fn->subtree,
1116 args + 1);
1117 if (!sfn)
1118 goto backtrack;
1119 fn = sfn;
1120 }
1121 #endif
1122 if (fn->fn_flags & RTN_RTINFO)
1123 return fn;
1124 }
1125 }
1126 #ifdef CONFIG_IPV6_SUBTREES
1127 backtrack:
1128 #endif
1129 if (fn->fn_flags & RTN_ROOT)
1130 break;
1131
1132 fn = fn->parent;
1133 }
1134
1135 return NULL;
1136 }
1137
1138 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr,
1139 const struct in6_addr *saddr)
1140 {
1141 struct fib6_node *fn;
1142 struct lookup_args args[] = {
1143 {
1144 .offset = offsetof(struct rt6_info, rt6i_dst),
1145 .addr = daddr,
1146 },
1147 #ifdef CONFIG_IPV6_SUBTREES
1148 {
1149 .offset = offsetof(struct rt6_info, rt6i_src),
1150 .addr = saddr,
1151 },
1152 #endif
1153 {
1154 .offset = 0, /* sentinel */
1155 }
1156 };
1157
1158 fn = fib6_lookup_1(root, daddr ? args : args + 1);
1159 if (!fn || fn->fn_flags & RTN_TL_ROOT)
1160 fn = root;
1161
1162 return fn;
1163 }
1164
1165 /*
1166 * Get node with specified destination prefix (and source prefix,
1167 * if subtrees are used)
1168 */
1169
1170
1171 static struct fib6_node *fib6_locate_1(struct fib6_node *root,
1172 const struct in6_addr *addr,
1173 int plen, int offset)
1174 {
1175 struct fib6_node *fn;
1176
1177 for (fn = root; fn ; ) {
1178 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
1179
1180 /*
1181 * Prefix match
1182 */
1183 if (plen < fn->fn_bit ||
1184 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
1185 return NULL;
1186
1187 if (plen == fn->fn_bit)
1188 return fn;
1189
1190 /*
1191 * We have more bits to go
1192 */
1193 if (addr_bit_set(addr, fn->fn_bit))
1194 fn = fn->right;
1195 else
1196 fn = fn->left;
1197 }
1198 return NULL;
1199 }
1200
1201 struct fib6_node *fib6_locate(struct fib6_node *root,
1202 const struct in6_addr *daddr, int dst_len,
1203 const struct in6_addr *saddr, int src_len)
1204 {
1205 struct fib6_node *fn;
1206
1207 fn = fib6_locate_1(root, daddr, dst_len,
1208 offsetof(struct rt6_info, rt6i_dst));
1209
1210 #ifdef CONFIG_IPV6_SUBTREES
1211 if (src_len) {
1212 WARN_ON(saddr == NULL);
1213 if (fn && fn->subtree)
1214 fn = fib6_locate_1(fn->subtree, saddr, src_len,
1215 offsetof(struct rt6_info, rt6i_src));
1216 }
1217 #endif
1218
1219 if (fn && fn->fn_flags & RTN_RTINFO)
1220 return fn;
1221
1222 return NULL;
1223 }
1224
1225
1226 /*
1227 * Deletion
1228 *
1229 */
1230
1231 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
1232 {
1233 if (fn->fn_flags & RTN_ROOT)
1234 return net->ipv6.ip6_null_entry;
1235
1236 while (fn) {
1237 if (fn->left)
1238 return fn->left->leaf;
1239 if (fn->right)
1240 return fn->right->leaf;
1241
1242 fn = FIB6_SUBTREE(fn);
1243 }
1244 return NULL;
1245 }
1246
1247 /*
1248 * Called to trim the tree of intermediate nodes when possible. "fn"
1249 * is the node we want to try and remove.
1250 */
1251
1252 static struct fib6_node *fib6_repair_tree(struct net *net,
1253 struct fib6_node *fn)
1254 {
1255 int children;
1256 int nstate;
1257 struct fib6_node *child, *pn;
1258 struct fib6_walker *w;
1259 int iter = 0;
1260
1261 for (;;) {
1262 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1263 iter++;
1264
1265 WARN_ON(fn->fn_flags & RTN_RTINFO);
1266 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1267 WARN_ON(fn->leaf);
1268
1269 children = 0;
1270 child = NULL;
1271 if (fn->right)
1272 child = fn->right, children |= 1;
1273 if (fn->left)
1274 child = fn->left, children |= 2;
1275
1276 if (children == 3 || FIB6_SUBTREE(fn)
1277 #ifdef CONFIG_IPV6_SUBTREES
1278 /* Subtree root (i.e. fn) may have one child */
1279 || (children && fn->fn_flags & RTN_ROOT)
1280 #endif
1281 ) {
1282 fn->leaf = fib6_find_prefix(net, fn);
1283 #if RT6_DEBUG >= 2
1284 if (!fn->leaf) {
1285 WARN_ON(!fn->leaf);
1286 fn->leaf = net->ipv6.ip6_null_entry;
1287 }
1288 #endif
1289 atomic_inc(&fn->leaf->rt6i_ref);
1290 return fn->parent;
1291 }
1292
1293 pn = fn->parent;
1294 #ifdef CONFIG_IPV6_SUBTREES
1295 if (FIB6_SUBTREE(pn) == fn) {
1296 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1297 FIB6_SUBTREE(pn) = NULL;
1298 nstate = FWS_L;
1299 } else {
1300 WARN_ON(fn->fn_flags & RTN_ROOT);
1301 #endif
1302 if (pn->right == fn)
1303 pn->right = child;
1304 else if (pn->left == fn)
1305 pn->left = child;
1306 #if RT6_DEBUG >= 2
1307 else
1308 WARN_ON(1);
1309 #endif
1310 if (child)
1311 child->parent = pn;
1312 nstate = FWS_R;
1313 #ifdef CONFIG_IPV6_SUBTREES
1314 }
1315 #endif
1316
1317 read_lock(&fib6_walker_lock);
1318 FOR_WALKERS(w) {
1319 if (!child) {
1320 if (w->root == fn) {
1321 w->root = w->node = NULL;
1322 RT6_TRACE("W %p adjusted by delroot 1\n", w);
1323 } else if (w->node == fn) {
1324 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1325 w->node = pn;
1326 w->state = nstate;
1327 }
1328 } else {
1329 if (w->root == fn) {
1330 w->root = child;
1331 RT6_TRACE("W %p adjusted by delroot 2\n", w);
1332 }
1333 if (w->node == fn) {
1334 w->node = child;
1335 if (children&2) {
1336 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1337 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT;
1338 } else {
1339 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1340 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT;
1341 }
1342 }
1343 }
1344 }
1345 read_unlock(&fib6_walker_lock);
1346
1347 node_free(fn);
1348 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
1349 return pn;
1350
1351 rt6_release(pn->leaf);
1352 pn->leaf = NULL;
1353 fn = pn;
1354 }
1355 }
1356
1357 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
1358 struct nl_info *info)
1359 {
1360 struct fib6_walker *w;
1361 struct rt6_info *rt = *rtp;
1362 struct net *net = info->nl_net;
1363
1364 RT6_TRACE("fib6_del_route\n");
1365
1366 /* Unlink it */
1367 *rtp = rt->dst.rt6_next;
1368 rt->rt6i_node = NULL;
1369 net->ipv6.rt6_stats->fib_rt_entries--;
1370 net->ipv6.rt6_stats->fib_discarded_routes++;
1371
1372 /* Reset round-robin state, if necessary */
1373 if (fn->rr_ptr == rt)
1374 fn->rr_ptr = NULL;
1375
1376 /* Remove this entry from other siblings */
1377 if (rt->rt6i_nsiblings) {
1378 struct rt6_info *sibling, *next_sibling;
1379
1380 list_for_each_entry_safe(sibling, next_sibling,
1381 &rt->rt6i_siblings, rt6i_siblings)
1382 sibling->rt6i_nsiblings--;
1383 rt->rt6i_nsiblings = 0;
1384 list_del_init(&rt->rt6i_siblings);
1385 }
1386
1387 /* Adjust walkers */
1388 read_lock(&fib6_walker_lock);
1389 FOR_WALKERS(w) {
1390 if (w->state == FWS_C && w->leaf == rt) {
1391 RT6_TRACE("walker %p adjusted by delroute\n", w);
1392 w->leaf = rt->dst.rt6_next;
1393 if (!w->leaf)
1394 w->state = FWS_U;
1395 }
1396 }
1397 read_unlock(&fib6_walker_lock);
1398
1399 rt->dst.rt6_next = NULL;
1400
1401 /* If it was last route, expunge its radix tree node */
1402 if (!fn->leaf) {
1403 fn->fn_flags &= ~RTN_RTINFO;
1404 net->ipv6.rt6_stats->fib_route_nodes--;
1405 fn = fib6_repair_tree(net, fn);
1406 }
1407
1408 fib6_purge_rt(rt, fn, net);
1409
1410 inet6_rt_notify(RTM_DELROUTE, rt, info);
1411 rt6_release(rt);
1412 }
1413
1414 int fib6_del(struct rt6_info *rt, struct nl_info *info)
1415 {
1416 struct net *net = info->nl_net;
1417 struct fib6_node *fn = rt->rt6i_node;
1418 struct rt6_info **rtp;
1419
1420 #if RT6_DEBUG >= 2
1421 if (rt->dst.obsolete > 0) {
1422 WARN_ON(fn);
1423 return -ENOENT;
1424 }
1425 #endif
1426 if (!fn || rt == net->ipv6.ip6_null_entry)
1427 return -ENOENT;
1428
1429 WARN_ON(!(fn->fn_flags & RTN_RTINFO));
1430
1431 if (!(rt->rt6i_flags & RTF_CACHE)) {
1432 struct fib6_node *pn = fn;
1433 #ifdef CONFIG_IPV6_SUBTREES
1434 /* clones of this route might be in another subtree */
1435 if (rt->rt6i_src.plen) {
1436 while (!(pn->fn_flags & RTN_ROOT))
1437 pn = pn->parent;
1438 pn = pn->parent;
1439 }
1440 #endif
1441 fib6_prune_clones(info->nl_net, pn);
1442 }
1443
1444 /*
1445 * Walk the leaf entries looking for ourself
1446 */
1447
1448 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) {
1449 if (*rtp == rt) {
1450 fib6_del_route(fn, rtp, info);
1451 return 0;
1452 }
1453 }
1454 return -ENOENT;
1455 }
1456
1457 /*
1458 * Tree traversal function.
1459 *
1460 * Certainly, it is not interrupt safe.
1461 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1462 * It means, that we can modify tree during walking
1463 * and use this function for garbage collection, clone pruning,
1464 * cleaning tree when a device goes down etc. etc.
1465 *
1466 * It guarantees that every node will be traversed,
1467 * and that it will be traversed only once.
1468 *
1469 * Callback function w->func may return:
1470 * 0 -> continue walking.
1471 * positive value -> walking is suspended (used by tree dumps,
1472 * and probably by gc, if it will be split to several slices)
1473 * negative value -> terminate walking.
1474 *
1475 * The function itself returns:
1476 * 0 -> walk is complete.
1477 * >0 -> walk is incomplete (i.e. suspended)
1478 * <0 -> walk is terminated by an error.
1479 */
1480
1481 static int fib6_walk_continue(struct fib6_walker *w)
1482 {
1483 struct fib6_node *fn, *pn;
1484
1485 for (;;) {
1486 fn = w->node;
1487 if (!fn)
1488 return 0;
1489
1490 if (w->prune && fn != w->root &&
1491 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) {
1492 w->state = FWS_C;
1493 w->leaf = fn->leaf;
1494 }
1495 switch (w->state) {
1496 #ifdef CONFIG_IPV6_SUBTREES
1497 case FWS_S:
1498 if (FIB6_SUBTREE(fn)) {
1499 w->node = FIB6_SUBTREE(fn);
1500 continue;
1501 }
1502 w->state = FWS_L;
1503 #endif
1504 case FWS_L:
1505 if (fn->left) {
1506 w->node = fn->left;
1507 w->state = FWS_INIT;
1508 continue;
1509 }
1510 w->state = FWS_R;
1511 case FWS_R:
1512 if (fn->right) {
1513 w->node = fn->right;
1514 w->state = FWS_INIT;
1515 continue;
1516 }
1517 w->state = FWS_C;
1518 w->leaf = fn->leaf;
1519 case FWS_C:
1520 if (w->leaf && fn->fn_flags & RTN_RTINFO) {
1521 int err;
1522
1523 if (w->skip) {
1524 w->skip--;
1525 goto skip;
1526 }
1527
1528 err = w->func(w);
1529 if (err)
1530 return err;
1531
1532 w->count++;
1533 continue;
1534 }
1535 skip:
1536 w->state = FWS_U;
1537 case FWS_U:
1538 if (fn == w->root)
1539 return 0;
1540 pn = fn->parent;
1541 w->node = pn;
1542 #ifdef CONFIG_IPV6_SUBTREES
1543 if (FIB6_SUBTREE(pn) == fn) {
1544 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1545 w->state = FWS_L;
1546 continue;
1547 }
1548 #endif
1549 if (pn->left == fn) {
1550 w->state = FWS_R;
1551 continue;
1552 }
1553 if (pn->right == fn) {
1554 w->state = FWS_C;
1555 w->leaf = w->node->leaf;
1556 continue;
1557 }
1558 #if RT6_DEBUG >= 2
1559 WARN_ON(1);
1560 #endif
1561 }
1562 }
1563 }
1564
1565 static int fib6_walk(struct fib6_walker *w)
1566 {
1567 int res;
1568
1569 w->state = FWS_INIT;
1570 w->node = w->root;
1571
1572 fib6_walker_link(w);
1573 res = fib6_walk_continue(w);
1574 if (res <= 0)
1575 fib6_walker_unlink(w);
1576 return res;
1577 }
1578
1579 static int fib6_clean_node(struct fib6_walker *w)
1580 {
1581 int res;
1582 struct rt6_info *rt;
1583 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w);
1584 struct nl_info info = {
1585 .nl_net = c->net,
1586 };
1587
1588 if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
1589 w->node->fn_sernum != c->sernum)
1590 w->node->fn_sernum = c->sernum;
1591
1592 if (!c->func) {
1593 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE);
1594 w->leaf = NULL;
1595 return 0;
1596 }
1597
1598 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
1599 res = c->func(rt, c->arg);
1600 if (res < 0) {
1601 w->leaf = rt;
1602 res = fib6_del(rt, &info);
1603 if (res) {
1604 #if RT6_DEBUG >= 2
1605 pr_debug("%s: del failed: rt=%p@%p err=%d\n",
1606 __func__, rt, rt->rt6i_node, res);
1607 #endif
1608 continue;
1609 }
1610 return 0;
1611 }
1612 WARN_ON(res != 0);
1613 }
1614 w->leaf = rt;
1615 return 0;
1616 }
1617
1618 /*
1619 * Convenient frontend to tree walker.
1620 *
1621 * func is called on each route.
1622 * It may return -1 -> delete this route.
1623 * 0 -> continue walking
1624 *
1625 * prune==1 -> only immediate children of node (certainly,
1626 * ignoring pure split nodes) will be scanned.
1627 */
1628
1629 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1630 int (*func)(struct rt6_info *, void *arg),
1631 bool prune, int sernum, void *arg)
1632 {
1633 struct fib6_cleaner c;
1634
1635 c.w.root = root;
1636 c.w.func = fib6_clean_node;
1637 c.w.prune = prune;
1638 c.w.count = 0;
1639 c.w.skip = 0;
1640 c.func = func;
1641 c.sernum = sernum;
1642 c.arg = arg;
1643 c.net = net;
1644
1645 fib6_walk(&c.w);
1646 }
1647
1648 static void __fib6_clean_all(struct net *net,
1649 int (*func)(struct rt6_info *, void *),
1650 int sernum, void *arg)
1651 {
1652 struct fib6_table *table;
1653 struct hlist_head *head;
1654 unsigned int h;
1655
1656 rcu_read_lock();
1657 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
1658 head = &net->ipv6.fib_table_hash[h];
1659 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
1660 write_lock_bh(&table->tb6_lock);
1661 fib6_clean_tree(net, &table->tb6_root,
1662 func, false, sernum, arg);
1663 write_unlock_bh(&table->tb6_lock);
1664 }
1665 }
1666 rcu_read_unlock();
1667 }
1668
1669 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *),
1670 void *arg)
1671 {
1672 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg);
1673 }
1674
1675 static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1676 {
1677 if (rt->rt6i_flags & RTF_CACHE) {
1678 RT6_TRACE("pruning clone %p\n", rt);
1679 return -1;
1680 }
1681
1682 return 0;
1683 }
1684
1685 static void fib6_prune_clones(struct net *net, struct fib6_node *fn)
1686 {
1687 fib6_clean_tree(net, fn, fib6_prune_clone, true,
1688 FIB6_NO_SERNUM_CHANGE, NULL);
1689 }
1690
1691 static void fib6_flush_trees(struct net *net)
1692 {
1693 int new_sernum = fib6_new_sernum(net);
1694
1695 __fib6_clean_all(net, NULL, new_sernum, NULL);
1696 }
1697
1698 /*
1699 * Garbage collection
1700 */
1701
1702 static struct fib6_gc_args
1703 {
1704 int timeout;
1705 int more;
1706 } gc_args;
1707
1708 static int fib6_age(struct rt6_info *rt, void *arg)
1709 {
1710 unsigned long now = jiffies;
1711
1712 /*
1713 * check addrconf expiration here.
1714 * Routes are expired even if they are in use.
1715 *
1716 * Also age clones. Note, that clones are aged out
1717 * only if they are not in use now.
1718 */
1719
1720 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) {
1721 if (time_after(now, rt->dst.expires)) {
1722 RT6_TRACE("expiring %p\n", rt);
1723 return -1;
1724 }
1725 gc_args.more++;
1726 } else if (rt->rt6i_flags & RTF_CACHE) {
1727 if (atomic_read(&rt->dst.__refcnt) == 0 &&
1728 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) {
1729 RT6_TRACE("aging clone %p\n", rt);
1730 return -1;
1731 } else if (rt->rt6i_flags & RTF_GATEWAY) {
1732 struct neighbour *neigh;
1733 __u8 neigh_flags = 0;
1734
1735 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway);
1736 if (neigh) {
1737 neigh_flags = neigh->flags;
1738 neigh_release(neigh);
1739 }
1740 if (!(neigh_flags & NTF_ROUTER)) {
1741 RT6_TRACE("purging route %p via non-router but gateway\n",
1742 rt);
1743 return -1;
1744 }
1745 }
1746 gc_args.more++;
1747 }
1748
1749 return 0;
1750 }
1751
1752 static DEFINE_SPINLOCK(fib6_gc_lock);
1753
1754 void fib6_run_gc(unsigned long expires, struct net *net, bool force)
1755 {
1756 unsigned long now;
1757
1758 if (force) {
1759 spin_lock_bh(&fib6_gc_lock);
1760 } else if (!spin_trylock_bh(&fib6_gc_lock)) {
1761 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
1762 return;
1763 }
1764 gc_args.timeout = expires ? (int)expires :
1765 net->ipv6.sysctl.ip6_rt_gc_interval;
1766
1767 gc_args.more = icmp6_dst_gc();
1768
1769 fib6_clean_all(net, fib6_age, NULL);
1770 now = jiffies;
1771 net->ipv6.ip6_rt_last_gc = now;
1772
1773 if (gc_args.more)
1774 mod_timer(&net->ipv6.ip6_fib_timer,
1775 round_jiffies(now
1776 + net->ipv6.sysctl.ip6_rt_gc_interval));
1777 else
1778 del_timer(&net->ipv6.ip6_fib_timer);
1779 spin_unlock_bh(&fib6_gc_lock);
1780 }
1781
1782 static void fib6_gc_timer_cb(unsigned long arg)
1783 {
1784 fib6_run_gc(0, (struct net *)arg, true);
1785 }
1786
1787 static int __net_init fib6_net_init(struct net *net)
1788 {
1789 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
1790
1791 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
1792
1793 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
1794 if (!net->ipv6.rt6_stats)
1795 goto out_timer;
1796
1797 /* Avoid false sharing : Use at least a full cache line */
1798 size = max_t(size_t, size, L1_CACHE_BYTES);
1799
1800 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
1801 if (!net->ipv6.fib_table_hash)
1802 goto out_rt6_stats;
1803
1804 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
1805 GFP_KERNEL);
1806 if (!net->ipv6.fib6_main_tbl)
1807 goto out_fib_table_hash;
1808
1809 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
1810 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1811 net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
1812 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1813 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
1814
1815 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1816 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
1817 GFP_KERNEL);
1818 if (!net->ipv6.fib6_local_tbl)
1819 goto out_fib6_main_tbl;
1820 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
1821 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1822 net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
1823 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1824 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
1825 #endif
1826 fib6_tables_init(net);
1827
1828 return 0;
1829
1830 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1831 out_fib6_main_tbl:
1832 kfree(net->ipv6.fib6_main_tbl);
1833 #endif
1834 out_fib_table_hash:
1835 kfree(net->ipv6.fib_table_hash);
1836 out_rt6_stats:
1837 kfree(net->ipv6.rt6_stats);
1838 out_timer:
1839 return -ENOMEM;
1840 }
1841
1842 static void fib6_net_exit(struct net *net)
1843 {
1844 rt6_ifdown(net, NULL);
1845 del_timer_sync(&net->ipv6.ip6_fib_timer);
1846
1847 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1848 inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers);
1849 kfree(net->ipv6.fib6_local_tbl);
1850 #endif
1851 inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers);
1852 kfree(net->ipv6.fib6_main_tbl);
1853 kfree(net->ipv6.fib_table_hash);
1854 kfree(net->ipv6.rt6_stats);
1855 }
1856
1857 static struct pernet_operations fib6_net_ops = {
1858 .init = fib6_net_init,
1859 .exit = fib6_net_exit,
1860 };
1861
1862 int __init fib6_init(void)
1863 {
1864 int ret = -ENOMEM;
1865
1866 fib6_node_kmem = kmem_cache_create("fib6_nodes",
1867 sizeof(struct fib6_node),
1868 0, SLAB_HWCACHE_ALIGN,
1869 NULL);
1870 if (!fib6_node_kmem)
1871 goto out;
1872
1873 ret = register_pernet_subsys(&fib6_net_ops);
1874 if (ret)
1875 goto out_kmem_cache_create;
1876
1877 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib,
1878 NULL);
1879 if (ret)
1880 goto out_unregister_subsys;
1881
1882 __fib6_flush_trees = fib6_flush_trees;
1883 out:
1884 return ret;
1885
1886 out_unregister_subsys:
1887 unregister_pernet_subsys(&fib6_net_ops);
1888 out_kmem_cache_create:
1889 kmem_cache_destroy(fib6_node_kmem);
1890 goto out;
1891 }
1892
1893 void fib6_gc_cleanup(void)
1894 {
1895 unregister_pernet_subsys(&fib6_net_ops);
1896 kmem_cache_destroy(fib6_node_kmem);
1897 }
1898
1899 #ifdef CONFIG_PROC_FS
1900
1901 struct ipv6_route_iter {
1902 struct seq_net_private p;
1903 struct fib6_walker w;
1904 loff_t skip;
1905 struct fib6_table *tbl;
1906 int sernum;
1907 };
1908
1909 static int ipv6_route_seq_show(struct seq_file *seq, void *v)
1910 {
1911 struct rt6_info *rt = v;
1912 struct ipv6_route_iter *iter = seq->private;
1913
1914 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen);
1915
1916 #ifdef CONFIG_IPV6_SUBTREES
1917 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen);
1918 #else
1919 seq_puts(seq, "00000000000000000000000000000000 00 ");
1920 #endif
1921 if (rt->rt6i_flags & RTF_GATEWAY)
1922 seq_printf(seq, "%pi6", &rt->rt6i_gateway);
1923 else
1924 seq_puts(seq, "00000000000000000000000000000000");
1925
1926 seq_printf(seq, " %08x %08x %08x %08x %8s\n",
1927 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt),
1928 rt->dst.__use, rt->rt6i_flags,
1929 rt->dst.dev ? rt->dst.dev->name : "");
1930 iter->w.leaf = NULL;
1931 return 0;
1932 }
1933
1934 static int ipv6_route_yield(struct fib6_walker *w)
1935 {
1936 struct ipv6_route_iter *iter = w->args;
1937
1938 if (!iter->skip)
1939 return 1;
1940
1941 do {
1942 iter->w.leaf = iter->w.leaf->dst.rt6_next;
1943 iter->skip--;
1944 if (!iter->skip && iter->w.leaf)
1945 return 1;
1946 } while (iter->w.leaf);
1947
1948 return 0;
1949 }
1950
1951 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter)
1952 {
1953 memset(&iter->w, 0, sizeof(iter->w));
1954 iter->w.func = ipv6_route_yield;
1955 iter->w.root = &iter->tbl->tb6_root;
1956 iter->w.state = FWS_INIT;
1957 iter->w.node = iter->w.root;
1958 iter->w.args = iter;
1959 iter->sernum = iter->w.root->fn_sernum;
1960 INIT_LIST_HEAD(&iter->w.lh);
1961 fib6_walker_link(&iter->w);
1962 }
1963
1964 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
1965 struct net *net)
1966 {
1967 unsigned int h;
1968 struct hlist_node *node;
1969
1970 if (tbl) {
1971 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1;
1972 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist));
1973 } else {
1974 h = 0;
1975 node = NULL;
1976 }
1977
1978 while (!node && h < FIB6_TABLE_HASHSZ) {
1979 node = rcu_dereference_bh(
1980 hlist_first_rcu(&net->ipv6.fib_table_hash[h++]));
1981 }
1982 return hlist_entry_safe(node, struct fib6_table, tb6_hlist);
1983 }
1984
1985 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter)
1986 {
1987 if (iter->sernum != iter->w.root->fn_sernum) {
1988 iter->sernum = iter->w.root->fn_sernum;
1989 iter->w.state = FWS_INIT;
1990 iter->w.node = iter->w.root;
1991 WARN_ON(iter->w.skip);
1992 iter->w.skip = iter->w.count;
1993 }
1994 }
1995
1996 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1997 {
1998 int r;
1999 struct rt6_info *n;
2000 struct net *net = seq_file_net(seq);
2001 struct ipv6_route_iter *iter = seq->private;
2002
2003 if (!v)
2004 goto iter_table;
2005
2006 n = ((struct rt6_info *)v)->dst.rt6_next;
2007 if (n) {
2008 ++*pos;
2009 return n;
2010 }
2011
2012 iter_table:
2013 ipv6_route_check_sernum(iter);
2014 read_lock(&iter->tbl->tb6_lock);
2015 r = fib6_walk_continue(&iter->w);
2016 read_unlock(&iter->tbl->tb6_lock);
2017 if (r > 0) {
2018 if (v)
2019 ++*pos;
2020 return iter->w.leaf;
2021 } else if (r < 0) {
2022 fib6_walker_unlink(&iter->w);
2023 return NULL;
2024 }
2025 fib6_walker_unlink(&iter->w);
2026
2027 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
2028 if (!iter->tbl)
2029 return NULL;
2030
2031 ipv6_route_seq_setup_walk(iter);
2032 goto iter_table;
2033 }
2034
2035 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
2036 __acquires(RCU_BH)
2037 {
2038 struct net *net = seq_file_net(seq);
2039 struct ipv6_route_iter *iter = seq->private;
2040
2041 rcu_read_lock_bh();
2042 iter->tbl = ipv6_route_seq_next_table(NULL, net);
2043 iter->skip = *pos;
2044
2045 if (iter->tbl) {
2046 ipv6_route_seq_setup_walk(iter);
2047 return ipv6_route_seq_next(seq, NULL, pos);
2048 } else {
2049 return NULL;
2050 }
2051 }
2052
2053 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter)
2054 {
2055 struct fib6_walker *w = &iter->w;
2056 return w->node && !(w->state == FWS_U && w->node == w->root);
2057 }
2058
2059 static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
2060 __releases(RCU_BH)
2061 {
2062 struct ipv6_route_iter *iter = seq->private;
2063
2064 if (ipv6_route_iter_active(iter))
2065 fib6_walker_unlink(&iter->w);
2066
2067 rcu_read_unlock_bh();
2068 }
2069
2070 static const struct seq_operations ipv6_route_seq_ops = {
2071 .start = ipv6_route_seq_start,
2072 .next = ipv6_route_seq_next,
2073 .stop = ipv6_route_seq_stop,
2074 .show = ipv6_route_seq_show
2075 };
2076
2077 int ipv6_route_open(struct inode *inode, struct file *file)
2078 {
2079 return seq_open_net(inode, file, &ipv6_route_seq_ops,
2080 sizeof(struct ipv6_route_iter));
2081 }
2082
2083 #endif /* CONFIG_PROC_FS */
Linux kernel - Deliverables
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