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Linux 4.19-rc7
[linux-2.6/btrfs-unstable.git] / net / ipv6 / ip6_fib.c
blob5516f55e214bd85ff7a07cf8c24648db327902c2
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 #include <net/lwtunnel.h>
36 #include <net/fib_notifier.h>
37
38 #include <net/ip6_fib.h>
39 #include <net/ip6_route.h>
40
41 static struct kmem_cache *fib6_node_kmem __read_mostly;
42
43 struct fib6_cleaner {
44 struct fib6_walker w;
45 struct net *net;
46 int (*func)(struct fib6_info *, void *arg);
47 int sernum;
48 void *arg;
49 };
50
51 #ifdef CONFIG_IPV6_SUBTREES
52 #define FWS_INIT FWS_S
53 #else
54 #define FWS_INIT FWS_L
55 #endif
56
57 static struct fib6_info *fib6_find_prefix(struct net *net,
58 struct fib6_table *table,
59 struct fib6_node *fn);
60 static struct fib6_node *fib6_repair_tree(struct net *net,
61 struct fib6_table *table,
62 struct fib6_node *fn);
63 static int fib6_walk(struct net *net, struct fib6_walker *w);
64 static int fib6_walk_continue(struct fib6_walker *w);
65
66 /*
67 * A routing update causes an increase of the serial number on the
68 * affected subtree. This allows for cached routes to be asynchronously
69 * tested when modifications are made to the destination cache as a
70 * result of redirects, path MTU changes, etc.
71 */
72
73 static void fib6_gc_timer_cb(struct timer_list *t);
74
75 #define FOR_WALKERS(net, w) \
76 list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh)
77
78 static void fib6_walker_link(struct net *net, struct fib6_walker *w)
79 {
80 write_lock_bh(&net->ipv6.fib6_walker_lock);
81 list_add(&w->lh, &net->ipv6.fib6_walkers);
82 write_unlock_bh(&net->ipv6.fib6_walker_lock);
83 }
84
85 static void fib6_walker_unlink(struct net *net, struct fib6_walker *w)
86 {
87 write_lock_bh(&net->ipv6.fib6_walker_lock);
88 list_del(&w->lh);
89 write_unlock_bh(&net->ipv6.fib6_walker_lock);
90 }
91
92 static int fib6_new_sernum(struct net *net)
93 {
94 int new, old;
95
96 do {
97 old = atomic_read(&net->ipv6.fib6_sernum);
98 new = old < INT_MAX ? old + 1 : 1;
99 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum,
100 old, new) != old);
101 return new;
102 }
103
104 enum {
105 FIB6_NO_SERNUM_CHANGE = 0,
106 };
107
108 void fib6_update_sernum(struct net *net, struct fib6_info *f6i)
109 {
110 struct fib6_node *fn;
111
112 fn = rcu_dereference_protected(f6i->fib6_node,
113 lockdep_is_held(&f6i->fib6_table->tb6_lock));
114 if (fn)
115 fn->fn_sernum = fib6_new_sernum(net);
116 }
117
118 /*
119 * Auxiliary address test functions for the radix tree.
120 *
121 * These assume a 32bit processor (although it will work on
122 * 64bit processors)
123 */
124
125 /*
126 * test bit
127 */
128 #if defined(__LITTLE_ENDIAN)
129 # define BITOP_BE32_SWIZZLE (0x1F & ~7)
130 #else
131 # define BITOP_BE32_SWIZZLE 0
132 #endif
133
134 static __be32 addr_bit_set(const void *token, int fn_bit)
135 {
136 const __be32 *addr = token;
137 /*
138 * Here,
139 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
140 * is optimized version of
141 * htonl(1 << ((~fn_bit)&0x1F))
142 * See include/asm-generic/bitops/le.h.
143 */
144 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
145 addr[fn_bit >> 5];
146 }
147
148 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags)
149 {
150 struct fib6_info *f6i;
151
152 f6i = kzalloc(sizeof(*f6i), gfp_flags);
153 if (!f6i)
154 return NULL;
155
156 f6i->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
157 if (!f6i->rt6i_pcpu) {
158 kfree(f6i);
159 return NULL;
160 }
161
162 INIT_LIST_HEAD(&f6i->fib6_siblings);
163 f6i->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
164
165 atomic_inc(&f6i->fib6_ref);
166
167 return f6i;
168 }
169
170 void fib6_info_destroy_rcu(struct rcu_head *head)
171 {
172 struct fib6_info *f6i = container_of(head, struct fib6_info, rcu);
173 struct rt6_exception_bucket *bucket;
174 struct dst_metrics *m;
175
176 WARN_ON(f6i->fib6_node);
177
178 bucket = rcu_dereference_protected(f6i->rt6i_exception_bucket, 1);
179 if (bucket) {
180 f6i->rt6i_exception_bucket = NULL;
181 kfree(bucket);
182 }
183
184 if (f6i->rt6i_pcpu) {
185 int cpu;
186
187 for_each_possible_cpu(cpu) {
188 struct rt6_info **ppcpu_rt;
189 struct rt6_info *pcpu_rt;
190
191 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu);
192 pcpu_rt = *ppcpu_rt;
193 if (pcpu_rt) {
194 dst_dev_put(&pcpu_rt->dst);
195 dst_release(&pcpu_rt->dst);
196 *ppcpu_rt = NULL;
197 }
198 }
199 }
200
201 lwtstate_put(f6i->fib6_nh.nh_lwtstate);
202
203 if (f6i->fib6_nh.nh_dev)
204 dev_put(f6i->fib6_nh.nh_dev);
205
206 m = f6i->fib6_metrics;
207 if (m != &dst_default_metrics && refcount_dec_and_test(&m->refcnt))
208 kfree(m);
209
210 kfree(f6i);
211 }
212 EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu);
213
214 static struct fib6_node *node_alloc(struct net *net)
215 {
216 struct fib6_node *fn;
217
218 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
219 if (fn)
220 net->ipv6.rt6_stats->fib_nodes++;
221
222 return fn;
223 }
224
225 static void node_free_immediate(struct net *net, struct fib6_node *fn)
226 {
227 kmem_cache_free(fib6_node_kmem, fn);
228 net->ipv6.rt6_stats->fib_nodes--;
229 }
230
231 static void node_free_rcu(struct rcu_head *head)
232 {
233 struct fib6_node *fn = container_of(head, struct fib6_node, rcu);
234
235 kmem_cache_free(fib6_node_kmem, fn);
236 }
237
238 static void node_free(struct net *net, struct fib6_node *fn)
239 {
240 call_rcu(&fn->rcu, node_free_rcu);
241 net->ipv6.rt6_stats->fib_nodes--;
242 }
243
244 static void fib6_free_table(struct fib6_table *table)
245 {
246 inetpeer_invalidate_tree(&table->tb6_peers);
247 kfree(table);
248 }
249
250 static void fib6_link_table(struct net *net, struct fib6_table *tb)
251 {
252 unsigned int h;
253
254 /*
255 * Initialize table lock at a single place to give lockdep a key,
256 * tables aren't visible prior to being linked to the list.
257 */
258 spin_lock_init(&tb->tb6_lock);
259 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
260
261 /*
262 * No protection necessary, this is the only list mutatation
263 * operation, tables never disappear once they exist.
264 */
265 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
266 }
267
268 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
269
270 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
271 {
272 struct fib6_table *table;
273
274 table = kzalloc(sizeof(*table), GFP_ATOMIC);
275 if (table) {
276 table->tb6_id = id;
277 rcu_assign_pointer(table->tb6_root.leaf,
278 net->ipv6.fib6_null_entry);
279 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
280 inet_peer_base_init(&table->tb6_peers);
281 }
282
283 return table;
284 }
285
286 struct fib6_table *fib6_new_table(struct net *net, u32 id)
287 {
288 struct fib6_table *tb;
289
290 if (id == 0)
291 id = RT6_TABLE_MAIN;
292 tb = fib6_get_table(net, id);
293 if (tb)
294 return tb;
295
296 tb = fib6_alloc_table(net, id);
297 if (tb)
298 fib6_link_table(net, tb);
299
300 return tb;
301 }
302 EXPORT_SYMBOL_GPL(fib6_new_table);
303
304 struct fib6_table *fib6_get_table(struct net *net, u32 id)
305 {
306 struct fib6_table *tb;
307 struct hlist_head *head;
308 unsigned int h;
309
310 if (id == 0)
311 id = RT6_TABLE_MAIN;
312 h = id & (FIB6_TABLE_HASHSZ - 1);
313 rcu_read_lock();
314 head = &net->ipv6.fib_table_hash[h];
315 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
316 if (tb->tb6_id == id) {
317 rcu_read_unlock();
318 return tb;
319 }
320 }
321 rcu_read_unlock();
322
323 return NULL;
324 }
325 EXPORT_SYMBOL_GPL(fib6_get_table);
326
327 static void __net_init fib6_tables_init(struct net *net)
328 {
329 fib6_link_table(net, net->ipv6.fib6_main_tbl);
330 fib6_link_table(net, net->ipv6.fib6_local_tbl);
331 }
332 #else
333
334 struct fib6_table *fib6_new_table(struct net *net, u32 id)
335 {
336 return fib6_get_table(net, id);
337 }
338
339 struct fib6_table *fib6_get_table(struct net *net, u32 id)
340 {
341 return net->ipv6.fib6_main_tbl;
342 }
343
344 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
345 const struct sk_buff *skb,
346 int flags, pol_lookup_t lookup)
347 {
348 struct rt6_info *rt;
349
350 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
351 if (rt->dst.error == -EAGAIN) {
352 ip6_rt_put(rt);
353 rt = net->ipv6.ip6_null_entry;
354 dst_hold(&rt->dst);
355 }
356
357 return &rt->dst;
358 }
359
360 /* called with rcu lock held; no reference taken on fib6_info */
361 struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
362 int flags)
363 {
364 return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6, flags);
365 }
366
367 static void __net_init fib6_tables_init(struct net *net)
368 {
369 fib6_link_table(net, net->ipv6.fib6_main_tbl);
370 }
371
372 #endif
373
374 unsigned int fib6_tables_seq_read(struct net *net)
375 {
376 unsigned int h, fib_seq = 0;
377
378 rcu_read_lock();
379 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
380 struct hlist_head *head = &net->ipv6.fib_table_hash[h];
381 struct fib6_table *tb;
382
383 hlist_for_each_entry_rcu(tb, head, tb6_hlist)
384 fib_seq += tb->fib_seq;
385 }
386 rcu_read_unlock();
387
388 return fib_seq;
389 }
390
391 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net,
392 enum fib_event_type event_type,
393 struct fib6_info *rt)
394 {
395 struct fib6_entry_notifier_info info = {
396 .rt = rt,
397 };
398
399 return call_fib6_notifier(nb, net, event_type, &info.info);
400 }
401
402 static int call_fib6_entry_notifiers(struct net *net,
403 enum fib_event_type event_type,
404 struct fib6_info *rt,
405 struct netlink_ext_ack *extack)
406 {
407 struct fib6_entry_notifier_info info = {
408 .info.extack = extack,
409 .rt = rt,
410 };
411
412 rt->fib6_table->fib_seq++;
413 return call_fib6_notifiers(net, event_type, &info.info);
414 }
415
416 struct fib6_dump_arg {
417 struct net *net;
418 struct notifier_block *nb;
419 };
420
421 static void fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg)
422 {
423 if (rt == arg->net->ipv6.fib6_null_entry)
424 return;
425 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt);
426 }
427
428 static int fib6_node_dump(struct fib6_walker *w)
429 {
430 struct fib6_info *rt;
431
432 for_each_fib6_walker_rt(w)
433 fib6_rt_dump(rt, w->args);
434 w->leaf = NULL;
435 return 0;
436 }
437
438 static void fib6_table_dump(struct net *net, struct fib6_table *tb,
439 struct fib6_walker *w)
440 {
441 w->root = &tb->tb6_root;
442 spin_lock_bh(&tb->tb6_lock);
443 fib6_walk(net, w);
444 spin_unlock_bh(&tb->tb6_lock);
445 }
446
447 /* Called with rcu_read_lock() */
448 int fib6_tables_dump(struct net *net, struct notifier_block *nb)
449 {
450 struct fib6_dump_arg arg;
451 struct fib6_walker *w;
452 unsigned int h;
453
454 w = kzalloc(sizeof(*w), GFP_ATOMIC);
455 if (!w)
456 return -ENOMEM;
457
458 w->func = fib6_node_dump;
459 arg.net = net;
460 arg.nb = nb;
461 w->args = &arg;
462
463 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
464 struct hlist_head *head = &net->ipv6.fib_table_hash[h];
465 struct fib6_table *tb;
466
467 hlist_for_each_entry_rcu(tb, head, tb6_hlist)
468 fib6_table_dump(net, tb, w);
469 }
470
471 kfree(w);
472
473 return 0;
474 }
475
476 static int fib6_dump_node(struct fib6_walker *w)
477 {
478 int res;
479 struct fib6_info *rt;
480
481 for_each_fib6_walker_rt(w) {
482 res = rt6_dump_route(rt, w->args);
483 if (res < 0) {
484 /* Frame is full, suspend walking */
485 w->leaf = rt;
486 return 1;
487 }
488
489 /* Multipath routes are dumped in one route with the
490 * RTA_MULTIPATH attribute. Jump 'rt' to point to the
491 * last sibling of this route (no need to dump the
492 * sibling routes again)
493 */
494 if (rt->fib6_nsiblings)
495 rt = list_last_entry(&rt->fib6_siblings,
496 struct fib6_info,
497 fib6_siblings);
498 }
499 w->leaf = NULL;
500 return 0;
501 }
502
503 static void fib6_dump_end(struct netlink_callback *cb)
504 {
505 struct net *net = sock_net(cb->skb->sk);
506 struct fib6_walker *w = (void *)cb->args[2];
507
508 if (w) {
509 if (cb->args[4]) {
510 cb->args[4] = 0;
511 fib6_walker_unlink(net, w);
512 }
513 cb->args[2] = 0;
514 kfree(w);
515 }
516 cb->done = (void *)cb->args[3];
517 cb->args[1] = 3;
518 }
519
520 static int fib6_dump_done(struct netlink_callback *cb)
521 {
522 fib6_dump_end(cb);
523 return cb->done ? cb->done(cb) : 0;
524 }
525
526 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
527 struct netlink_callback *cb)
528 {
529 struct net *net = sock_net(skb->sk);
530 struct fib6_walker *w;
531 int res;
532
533 w = (void *)cb->args[2];
534 w->root = &table->tb6_root;
535
536 if (cb->args[4] == 0) {
537 w->count = 0;
538 w->skip = 0;
539
540 spin_lock_bh(&table->tb6_lock);
541 res = fib6_walk(net, w);
542 spin_unlock_bh(&table->tb6_lock);
543 if (res > 0) {
544 cb->args[4] = 1;
545 cb->args[5] = w->root->fn_sernum;
546 }
547 } else {
548 if (cb->args[5] != w->root->fn_sernum) {
549 /* Begin at the root if the tree changed */
550 cb->args[5] = w->root->fn_sernum;
551 w->state = FWS_INIT;
552 w->node = w->root;
553 w->skip = w->count;
554 } else
555 w->skip = 0;
556
557 spin_lock_bh(&table->tb6_lock);
558 res = fib6_walk_continue(w);
559 spin_unlock_bh(&table->tb6_lock);
560 if (res <= 0) {
561 fib6_walker_unlink(net, w);
562 cb->args[4] = 0;
563 }
564 }
565
566 return res;
567 }
568
569 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
570 {
571 struct net *net = sock_net(skb->sk);
572 unsigned int h, s_h;
573 unsigned int e = 0, s_e;
574 struct rt6_rtnl_dump_arg arg;
575 struct fib6_walker *w;
576 struct fib6_table *tb;
577 struct hlist_head *head;
578 int res = 0;
579
580 s_h = cb->args[0];
581 s_e = cb->args[1];
582
583 w = (void *)cb->args[2];
584 if (!w) {
585 /* New dump:
586 *
587 * 1. hook callback destructor.
588 */
589 cb->args[3] = (long)cb->done;
590 cb->done = fib6_dump_done;
591
592 /*
593 * 2. allocate and initialize walker.
594 */
595 w = kzalloc(sizeof(*w), GFP_ATOMIC);
596 if (!w)
597 return -ENOMEM;
598 w->func = fib6_dump_node;
599 cb->args[2] = (long)w;
600 }
601
602 arg.skb = skb;
603 arg.cb = cb;
604 arg.net = net;
605 w->args = &arg;
606
607 rcu_read_lock();
608 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
609 e = 0;
610 head = &net->ipv6.fib_table_hash[h];
611 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
612 if (e < s_e)
613 goto next;
614 res = fib6_dump_table(tb, skb, cb);
615 if (res != 0)
616 goto out;
617 next:
618 e++;
619 }
620 }
621 out:
622 rcu_read_unlock();
623 cb->args[1] = e;
624 cb->args[0] = h;
625
626 res = res < 0 ? res : skb->len;
627 if (res <= 0)
628 fib6_dump_end(cb);
629 return res;
630 }
631
632 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val)
633 {
634 if (!f6i)
635 return;
636
637 if (f6i->fib6_metrics == &dst_default_metrics) {
638 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC);
639
640 if (!p)
641 return;
642
643 refcount_set(&p->refcnt, 1);
644 f6i->fib6_metrics = p;
645 }
646
647 f6i->fib6_metrics->metrics[metric - 1] = val;
648 }
649
650 /*
651 * Routing Table
652 *
653 * return the appropriate node for a routing tree "add" operation
654 * by either creating and inserting or by returning an existing
655 * node.
656 */
657
658 static struct fib6_node *fib6_add_1(struct net *net,
659 struct fib6_table *table,
660 struct fib6_node *root,
661 struct in6_addr *addr, int plen,
662 int offset, int allow_create,
663 int replace_required,
664 struct netlink_ext_ack *extack)
665 {
666 struct fib6_node *fn, *in, *ln;
667 struct fib6_node *pn = NULL;
668 struct rt6key *key;
669 int bit;
670 __be32 dir = 0;
671
672 RT6_TRACE("fib6_add_1\n");
673
674 /* insert node in tree */
675
676 fn = root;
677
678 do {
679 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
680 lockdep_is_held(&table->tb6_lock));
681 key = (struct rt6key *)((u8 *)leaf + offset);
682
683 /*
684 * Prefix match
685 */
686 if (plen < fn->fn_bit ||
687 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
688 if (!allow_create) {
689 if (replace_required) {
690 NL_SET_ERR_MSG(extack,
691 "Can not replace route - no match found");
692 pr_warn("Can't replace route, no match found\n");
693 return ERR_PTR(-ENOENT);
694 }
695 pr_warn("NLM_F_CREATE should be set when creating new route\n");
696 }
697 goto insert_above;
698 }
699
700 /*
701 * Exact match ?
702 */
703
704 if (plen == fn->fn_bit) {
705 /* clean up an intermediate node */
706 if (!(fn->fn_flags & RTN_RTINFO)) {
707 RCU_INIT_POINTER(fn->leaf, NULL);
708 fib6_info_release(leaf);
709 /* remove null_entry in the root node */
710 } else if (fn->fn_flags & RTN_TL_ROOT &&
711 rcu_access_pointer(fn->leaf) ==
712 net->ipv6.fib6_null_entry) {
713 RCU_INIT_POINTER(fn->leaf, NULL);
714 }
715
716 return fn;
717 }
718
719 /*
720 * We have more bits to go
721 */
722
723 /* Try to walk down on tree. */
724 dir = addr_bit_set(addr, fn->fn_bit);
725 pn = fn;
726 fn = dir ?
727 rcu_dereference_protected(fn->right,
728 lockdep_is_held(&table->tb6_lock)) :
729 rcu_dereference_protected(fn->left,
730 lockdep_is_held(&table->tb6_lock));
731 } while (fn);
732
733 if (!allow_create) {
734 /* We should not create new node because
735 * NLM_F_REPLACE was specified without NLM_F_CREATE
736 * I assume it is safe to require NLM_F_CREATE when
737 * REPLACE flag is used! Later we may want to remove the
738 * check for replace_required, because according
739 * to netlink specification, NLM_F_CREATE
740 * MUST be specified if new route is created.
741 * That would keep IPv6 consistent with IPv4
742 */
743 if (replace_required) {
744 NL_SET_ERR_MSG(extack,
745 "Can not replace route - no match found");
746 pr_warn("Can't replace route, no match found\n");
747 return ERR_PTR(-ENOENT);
748 }
749 pr_warn("NLM_F_CREATE should be set when creating new route\n");
750 }
751 /*
752 * We walked to the bottom of tree.
753 * Create new leaf node without children.
754 */
755
756 ln = node_alloc(net);
757
758 if (!ln)
759 return ERR_PTR(-ENOMEM);
760 ln->fn_bit = plen;
761 RCU_INIT_POINTER(ln->parent, pn);
762
763 if (dir)
764 rcu_assign_pointer(pn->right, ln);
765 else
766 rcu_assign_pointer(pn->left, ln);
767
768 return ln;
769
770
771 insert_above:
772 /*
773 * split since we don't have a common prefix anymore or
774 * we have a less significant route.
775 * we've to insert an intermediate node on the list
776 * this new node will point to the one we need to create
777 * and the current
778 */
779
780 pn = rcu_dereference_protected(fn->parent,
781 lockdep_is_held(&table->tb6_lock));
782
783 /* find 1st bit in difference between the 2 addrs.
784
785 See comment in __ipv6_addr_diff: bit may be an invalid value,
786 but if it is >= plen, the value is ignored in any case.
787 */
788
789 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr));
790
791 /*
792 * (intermediate)[in]
793 * / \
794 * (new leaf node)[ln] (old node)[fn]
795 */
796 if (plen > bit) {
797 in = node_alloc(net);
798 ln = node_alloc(net);
799
800 if (!in || !ln) {
801 if (in)
802 node_free_immediate(net, in);
803 if (ln)
804 node_free_immediate(net, ln);
805 return ERR_PTR(-ENOMEM);
806 }
807
808 /*
809 * new intermediate node.
810 * RTN_RTINFO will
811 * be off since that an address that chooses one of
812 * the branches would not match less specific routes
813 * in the other branch
814 */
815
816 in->fn_bit = bit;
817
818 RCU_INIT_POINTER(in->parent, pn);
819 in->leaf = fn->leaf;
820 atomic_inc(&rcu_dereference_protected(in->leaf,
821 lockdep_is_held(&table->tb6_lock))->fib6_ref);
822
823 /* update parent pointer */
824 if (dir)
825 rcu_assign_pointer(pn->right, in);
826 else
827 rcu_assign_pointer(pn->left, in);
828
829 ln->fn_bit = plen;
830
831 RCU_INIT_POINTER(ln->parent, in);
832 rcu_assign_pointer(fn->parent, in);
833
834 if (addr_bit_set(addr, bit)) {
835 rcu_assign_pointer(in->right, ln);
836 rcu_assign_pointer(in->left, fn);
837 } else {
838 rcu_assign_pointer(in->left, ln);
839 rcu_assign_pointer(in->right, fn);
840 }
841 } else { /* plen <= bit */
842
843 /*
844 * (new leaf node)[ln]
845 * / \
846 * (old node)[fn] NULL
847 */
848
849 ln = node_alloc(net);
850
851 if (!ln)
852 return ERR_PTR(-ENOMEM);
853
854 ln->fn_bit = plen;
855
856 RCU_INIT_POINTER(ln->parent, pn);
857
858 if (addr_bit_set(&key->addr, plen))
859 RCU_INIT_POINTER(ln->right, fn);
860 else
861 RCU_INIT_POINTER(ln->left, fn);
862
863 rcu_assign_pointer(fn->parent, ln);
864
865 if (dir)
866 rcu_assign_pointer(pn->right, ln);
867 else
868 rcu_assign_pointer(pn->left, ln);
869 }
870 return ln;
871 }
872
873 static void fib6_drop_pcpu_from(struct fib6_info *f6i,
874 const struct fib6_table *table)
875 {
876 int cpu;
877
878 /* release the reference to this fib entry from
879 * all of its cached pcpu routes
880 */
881 for_each_possible_cpu(cpu) {
882 struct rt6_info **ppcpu_rt;
883 struct rt6_info *pcpu_rt;
884
885 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu);
886 pcpu_rt = *ppcpu_rt;
887 if (pcpu_rt) {
888 struct fib6_info *from;
889
890 from = rcu_dereference_protected(pcpu_rt->from,
891 lockdep_is_held(&table->tb6_lock));
892 rcu_assign_pointer(pcpu_rt->from, NULL);
893 fib6_info_release(from);
894 }
895 }
896 }
897
898 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,
899 struct net *net)
900 {
901 struct fib6_table *table = rt->fib6_table;
902
903 if (atomic_read(&rt->fib6_ref) != 1) {
904 /* This route is used as dummy address holder in some split
905 * nodes. It is not leaked, but it still holds other resources,
906 * which must be released in time. So, scan ascendant nodes
907 * and replace dummy references to this route with references
908 * to still alive ones.
909 */
910 while (fn) {
911 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
912 lockdep_is_held(&table->tb6_lock));
913 struct fib6_info *new_leaf;
914 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) {
915 new_leaf = fib6_find_prefix(net, table, fn);
916 atomic_inc(&new_leaf->fib6_ref);
917
918 rcu_assign_pointer(fn->leaf, new_leaf);
919 fib6_info_release(rt);
920 }
921 fn = rcu_dereference_protected(fn->parent,
922 lockdep_is_held(&table->tb6_lock));
923 }
924
925 if (rt->rt6i_pcpu)
926 fib6_drop_pcpu_from(rt, table);
927 }
928 }
929
930 /*
931 * Insert routing information in a node.
932 */
933
934 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
935 struct nl_info *info,
936 struct netlink_ext_ack *extack)
937 {
938 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
939 lockdep_is_held(&rt->fib6_table->tb6_lock));
940 struct fib6_info *iter = NULL;
941 struct fib6_info __rcu **ins;
942 struct fib6_info __rcu **fallback_ins = NULL;
943 int replace = (info->nlh &&
944 (info->nlh->nlmsg_flags & NLM_F_REPLACE));
945 int add = (!info->nlh ||
946 (info->nlh->nlmsg_flags & NLM_F_CREATE));
947 int found = 0;
948 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
949 u16 nlflags = NLM_F_EXCL;
950 int err;
951
952 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND))
953 nlflags |= NLM_F_APPEND;
954
955 ins = &fn->leaf;
956
957 for (iter = leaf; iter;
958 iter = rcu_dereference_protected(iter->fib6_next,
959 lockdep_is_held(&rt->fib6_table->tb6_lock))) {
960 /*
961 * Search for duplicates
962 */
963
964 if (iter->fib6_metric == rt->fib6_metric) {
965 /*
966 * Same priority level
967 */
968 if (info->nlh &&
969 (info->nlh->nlmsg_flags & NLM_F_EXCL))
970 return -EEXIST;
971
972 nlflags &= ~NLM_F_EXCL;
973 if (replace) {
974 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) {
975 found++;
976 break;
977 }
978 if (rt_can_ecmp)
979 fallback_ins = fallback_ins ?: ins;
980 goto next_iter;
981 }
982
983 if (rt6_duplicate_nexthop(iter, rt)) {
984 if (rt->fib6_nsiblings)
985 rt->fib6_nsiblings = 0;
986 if (!(iter->fib6_flags & RTF_EXPIRES))
987 return -EEXIST;
988 if (!(rt->fib6_flags & RTF_EXPIRES))
989 fib6_clean_expires(iter);
990 else
991 fib6_set_expires(iter, rt->expires);
992
993 if (rt->fib6_pmtu)
994 fib6_metric_set(iter, RTAX_MTU,
995 rt->fib6_pmtu);
996 return -EEXIST;
997 }
998 /* If we have the same destination and the same metric,
999 * but not the same gateway, then the route we try to
1000 * add is sibling to this route, increment our counter
1001 * of siblings, and later we will add our route to the
1002 * list.
1003 * Only static routes (which don't have flag
1004 * RTF_EXPIRES) are used for ECMPv6.
1005 *
1006 * To avoid long list, we only had siblings if the
1007 * route have a gateway.
1008 */
1009 if (rt_can_ecmp &&
1010 rt6_qualify_for_ecmp(iter))
1011 rt->fib6_nsiblings++;
1012 }
1013
1014 if (iter->fib6_metric > rt->fib6_metric)
1015 break;
1016
1017 next_iter:
1018 ins = &iter->fib6_next;
1019 }
1020
1021 if (fallback_ins && !found) {
1022 /* No ECMP-able route found, replace first non-ECMP one */
1023 ins = fallback_ins;
1024 iter = rcu_dereference_protected(*ins,
1025 lockdep_is_held(&rt->fib6_table->tb6_lock));
1026 found++;
1027 }
1028
1029 /* Reset round-robin state, if necessary */
1030 if (ins == &fn->leaf)
1031 fn->rr_ptr = NULL;
1032
1033 /* Link this route to others same route. */
1034 if (rt->fib6_nsiblings) {
1035 unsigned int fib6_nsiblings;
1036 struct fib6_info *sibling, *temp_sibling;
1037
1038 /* Find the first route that have the same metric */
1039 sibling = leaf;
1040 while (sibling) {
1041 if (sibling->fib6_metric == rt->fib6_metric &&
1042 rt6_qualify_for_ecmp(sibling)) {
1043 list_add_tail(&rt->fib6_siblings,
1044 &sibling->fib6_siblings);
1045 break;
1046 }
1047 sibling = rcu_dereference_protected(sibling->fib6_next,
1048 lockdep_is_held(&rt->fib6_table->tb6_lock));
1049 }
1050 /* For each sibling in the list, increment the counter of
1051 * siblings. BUG() if counters does not match, list of siblings
1052 * is broken!
1053 */
1054 fib6_nsiblings = 0;
1055 list_for_each_entry_safe(sibling, temp_sibling,
1056 &rt->fib6_siblings, fib6_siblings) {
1057 sibling->fib6_nsiblings++;
1058 BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings);
1059 fib6_nsiblings++;
1060 }
1061 BUG_ON(fib6_nsiblings != rt->fib6_nsiblings);
1062 rt6_multipath_rebalance(temp_sibling);
1063 }
1064
1065 /*
1066 * insert node
1067 */
1068 if (!replace) {
1069 if (!add)
1070 pr_warn("NLM_F_CREATE should be set when creating new route\n");
1071
1072 add:
1073 nlflags |= NLM_F_CREATE;
1074
1075 err = call_fib6_entry_notifiers(info->nl_net,
1076 FIB_EVENT_ENTRY_ADD,
1077 rt, extack);
1078 if (err)
1079 return err;
1080
1081 rcu_assign_pointer(rt->fib6_next, iter);
1082 atomic_inc(&rt->fib6_ref);
1083 rcu_assign_pointer(rt->fib6_node, fn);
1084 rcu_assign_pointer(*ins, rt);
1085 if (!info->skip_notify)
1086 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
1087 info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
1088
1089 if (!(fn->fn_flags & RTN_RTINFO)) {
1090 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
1091 fn->fn_flags |= RTN_RTINFO;
1092 }
1093
1094 } else {
1095 int nsiblings;
1096
1097 if (!found) {
1098 if (add)
1099 goto add;
1100 pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
1101 return -ENOENT;
1102 }
1103
1104 err = call_fib6_entry_notifiers(info->nl_net,
1105 FIB_EVENT_ENTRY_REPLACE,
1106 rt, extack);
1107 if (err)
1108 return err;
1109
1110 atomic_inc(&rt->fib6_ref);
1111 rcu_assign_pointer(rt->fib6_node, fn);
1112 rt->fib6_next = iter->fib6_next;
1113 rcu_assign_pointer(*ins, rt);
1114 if (!info->skip_notify)
1115 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE);
1116 if (!(fn->fn_flags & RTN_RTINFO)) {
1117 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
1118 fn->fn_flags |= RTN_RTINFO;
1119 }
1120 nsiblings = iter->fib6_nsiblings;
1121 iter->fib6_node = NULL;
1122 fib6_purge_rt(iter, fn, info->nl_net);
1123 if (rcu_access_pointer(fn->rr_ptr) == iter)
1124 fn->rr_ptr = NULL;
1125 fib6_info_release(iter);
1126
1127 if (nsiblings) {
1128 /* Replacing an ECMP route, remove all siblings */
1129 ins = &rt->fib6_next;
1130 iter = rcu_dereference_protected(*ins,
1131 lockdep_is_held(&rt->fib6_table->tb6_lock));
1132 while (iter) {
1133 if (iter->fib6_metric > rt->fib6_metric)
1134 break;
1135 if (rt6_qualify_for_ecmp(iter)) {
1136 *ins = iter->fib6_next;
1137 iter->fib6_node = NULL;
1138 fib6_purge_rt(iter, fn, info->nl_net);
1139 if (rcu_access_pointer(fn->rr_ptr) == iter)
1140 fn->rr_ptr = NULL;
1141 fib6_info_release(iter);
1142 nsiblings--;
1143 info->nl_net->ipv6.rt6_stats->fib_rt_entries--;
1144 } else {
1145 ins = &iter->fib6_next;
1146 }
1147 iter = rcu_dereference_protected(*ins,
1148 lockdep_is_held(&rt->fib6_table->tb6_lock));
1149 }
1150 WARN_ON(nsiblings != 0);
1151 }
1152 }
1153
1154 return 0;
1155 }
1156
1157 static void fib6_start_gc(struct net *net, struct fib6_info *rt)
1158 {
1159 if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
1160 (rt->fib6_flags & RTF_EXPIRES))
1161 mod_timer(&net->ipv6.ip6_fib_timer,
1162 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
1163 }
1164
1165 void fib6_force_start_gc(struct net *net)
1166 {
1167 if (!timer_pending(&net->ipv6.ip6_fib_timer))
1168 mod_timer(&net->ipv6.ip6_fib_timer,
1169 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
1170 }
1171
1172 static void __fib6_update_sernum_upto_root(struct fib6_info *rt,
1173 int sernum)
1174 {
1175 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node,
1176 lockdep_is_held(&rt->fib6_table->tb6_lock));
1177
1178 /* paired with smp_rmb() in rt6_get_cookie_safe() */
1179 smp_wmb();
1180 while (fn) {
1181 fn->fn_sernum = sernum;
1182 fn = rcu_dereference_protected(fn->parent,
1183 lockdep_is_held(&rt->fib6_table->tb6_lock));
1184 }
1185 }
1186
1187 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt)
1188 {
1189 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net));
1190 }
1191
1192 /*
1193 * Add routing information to the routing tree.
1194 * <destination addr>/<source addr>
1195 * with source addr info in sub-trees
1196 * Need to own table->tb6_lock
1197 */
1198
1199 int fib6_add(struct fib6_node *root, struct fib6_info *rt,
1200 struct nl_info *info, struct netlink_ext_ack *extack)
1201 {
1202 struct fib6_table *table = rt->fib6_table;
1203 struct fib6_node *fn, *pn = NULL;
1204 int err = -ENOMEM;
1205 int allow_create = 1;
1206 int replace_required = 0;
1207 int sernum = fib6_new_sernum(info->nl_net);
1208
1209 if (info->nlh) {
1210 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
1211 allow_create = 0;
1212 if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
1213 replace_required = 1;
1214 }
1215 if (!allow_create && !replace_required)
1216 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
1217
1218 fn = fib6_add_1(info->nl_net, table, root,
1219 &rt->fib6_dst.addr, rt->fib6_dst.plen,
1220 offsetof(struct fib6_info, fib6_dst), allow_create,
1221 replace_required, extack);
1222 if (IS_ERR(fn)) {
1223 err = PTR_ERR(fn);
1224 fn = NULL;
1225 goto out;
1226 }
1227
1228 pn = fn;
1229
1230 #ifdef CONFIG_IPV6_SUBTREES
1231 if (rt->fib6_src.plen) {
1232 struct fib6_node *sn;
1233
1234 if (!rcu_access_pointer(fn->subtree)) {
1235 struct fib6_node *sfn;
1236
1237 /*
1238 * Create subtree.
1239 *
1240 * fn[main tree]
1241 * |
1242 * sfn[subtree root]
1243 * \
1244 * sn[new leaf node]
1245 */
1246
1247 /* Create subtree root node */
1248 sfn = node_alloc(info->nl_net);
1249 if (!sfn)
1250 goto failure;
1251
1252 atomic_inc(&info->nl_net->ipv6.fib6_null_entry->fib6_ref);
1253 rcu_assign_pointer(sfn->leaf,
1254 info->nl_net->ipv6.fib6_null_entry);
1255 sfn->fn_flags = RTN_ROOT;
1256
1257 /* Now add the first leaf node to new subtree */
1258
1259 sn = fib6_add_1(info->nl_net, table, sfn,
1260 &rt->fib6_src.addr, rt->fib6_src.plen,
1261 offsetof(struct fib6_info, fib6_src),
1262 allow_create, replace_required, extack);
1263
1264 if (IS_ERR(sn)) {
1265 /* If it is failed, discard just allocated
1266 root, and then (in failure) stale node
1267 in main tree.
1268 */
1269 node_free_immediate(info->nl_net, sfn);
1270 err = PTR_ERR(sn);
1271 goto failure;
1272 }
1273
1274 /* Now link new subtree to main tree */
1275 rcu_assign_pointer(sfn->parent, fn);
1276 rcu_assign_pointer(fn->subtree, sfn);
1277 } else {
1278 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn),
1279 &rt->fib6_src.addr, rt->fib6_src.plen,
1280 offsetof(struct fib6_info, fib6_src),
1281 allow_create, replace_required, extack);
1282
1283 if (IS_ERR(sn)) {
1284 err = PTR_ERR(sn);
1285 goto failure;
1286 }
1287 }
1288
1289 if (!rcu_access_pointer(fn->leaf)) {
1290 if (fn->fn_flags & RTN_TL_ROOT) {
1291 /* put back null_entry for root node */
1292 rcu_assign_pointer(fn->leaf,
1293 info->nl_net->ipv6.fib6_null_entry);
1294 } else {
1295 atomic_inc(&rt->fib6_ref);
1296 rcu_assign_pointer(fn->leaf, rt);
1297 }
1298 }
1299 fn = sn;
1300 }
1301 #endif
1302
1303 err = fib6_add_rt2node(fn, rt, info, extack);
1304 if (!err) {
1305 __fib6_update_sernum_upto_root(rt, sernum);
1306 fib6_start_gc(info->nl_net, rt);
1307 }
1308
1309 out:
1310 if (err) {
1311 #ifdef CONFIG_IPV6_SUBTREES
1312 /*
1313 * If fib6_add_1 has cleared the old leaf pointer in the
1314 * super-tree leaf node we have to find a new one for it.
1315 */
1316 if (pn != fn) {
1317 struct fib6_info *pn_leaf =
1318 rcu_dereference_protected(pn->leaf,
1319 lockdep_is_held(&table->tb6_lock));
1320 if (pn_leaf == rt) {
1321 pn_leaf = NULL;
1322 RCU_INIT_POINTER(pn->leaf, NULL);
1323 fib6_info_release(rt);
1324 }
1325 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) {
1326 pn_leaf = fib6_find_prefix(info->nl_net, table,
1327 pn);
1328 #if RT6_DEBUG >= 2
1329 if (!pn_leaf) {
1330 WARN_ON(!pn_leaf);
1331 pn_leaf =
1332 info->nl_net->ipv6.fib6_null_entry;
1333 }
1334 #endif
1335 fib6_info_hold(pn_leaf);
1336 rcu_assign_pointer(pn->leaf, pn_leaf);
1337 }
1338 }
1339 #endif
1340 goto failure;
1341 }
1342 return err;
1343
1344 failure:
1345 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if:
1346 * 1. fn is an intermediate node and we failed to add the new
1347 * route to it in both subtree creation failure and fib6_add_rt2node()
1348 * failure case.
1349 * 2. fn is the root node in the table and we fail to add the first
1350 * default route to it.
1351 */
1352 if (fn &&
1353 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) ||
1354 (fn->fn_flags & RTN_TL_ROOT &&
1355 !rcu_access_pointer(fn->leaf))))
1356 fib6_repair_tree(info->nl_net, table, fn);
1357 return err;
1358 }
1359
1360 /*
1361 * Routing tree lookup
1362 *
1363 */
1364
1365 struct lookup_args {
1366 int offset; /* key offset on fib6_info */
1367 const struct in6_addr *addr; /* search key */
1368 };
1369
1370 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root,
1371 struct lookup_args *args)
1372 {
1373 struct fib6_node *fn;
1374 __be32 dir;
1375
1376 if (unlikely(args->offset == 0))
1377 return NULL;
1378
1379 /*
1380 * Descend on a tree
1381 */
1382
1383 fn = root;
1384
1385 for (;;) {
1386 struct fib6_node *next;
1387
1388 dir = addr_bit_set(args->addr, fn->fn_bit);
1389
1390 next = dir ? rcu_dereference(fn->right) :
1391 rcu_dereference(fn->left);
1392
1393 if (next) {
1394 fn = next;
1395 continue;
1396 }
1397 break;
1398 }
1399
1400 while (fn) {
1401 struct fib6_node *subtree = FIB6_SUBTREE(fn);
1402
1403 if (subtree || fn->fn_flags & RTN_RTINFO) {
1404 struct fib6_info *leaf = rcu_dereference(fn->leaf);
1405 struct rt6key *key;
1406
1407 if (!leaf)
1408 goto backtrack;
1409
1410 key = (struct rt6key *) ((u8 *)leaf + args->offset);
1411
1412 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
1413 #ifdef CONFIG_IPV6_SUBTREES
1414 if (subtree) {
1415 struct fib6_node *sfn;
1416 sfn = fib6_node_lookup_1(subtree,
1417 args + 1);
1418 if (!sfn)
1419 goto backtrack;
1420 fn = sfn;
1421 }
1422 #endif
1423 if (fn->fn_flags & RTN_RTINFO)
1424 return fn;
1425 }
1426 }
1427 backtrack:
1428 if (fn->fn_flags & RTN_ROOT)
1429 break;
1430
1431 fn = rcu_dereference(fn->parent);
1432 }
1433
1434 return NULL;
1435 }
1436
1437 /* called with rcu_read_lock() held
1438 */
1439 struct fib6_node *fib6_node_lookup(struct fib6_node *root,
1440 const struct in6_addr *daddr,
1441 const struct in6_addr *saddr)
1442 {
1443 struct fib6_node *fn;
1444 struct lookup_args args[] = {
1445 {
1446 .offset = offsetof(struct fib6_info, fib6_dst),
1447 .addr = daddr,
1448 },
1449 #ifdef CONFIG_IPV6_SUBTREES
1450 {
1451 .offset = offsetof(struct fib6_info, fib6_src),
1452 .addr = saddr,
1453 },
1454 #endif
1455 {
1456 .offset = 0, /* sentinel */
1457 }
1458 };
1459
1460 fn = fib6_node_lookup_1(root, daddr ? args : args + 1);
1461 if (!fn || fn->fn_flags & RTN_TL_ROOT)
1462 fn = root;
1463
1464 return fn;
1465 }
1466
1467 /*
1468 * Get node with specified destination prefix (and source prefix,
1469 * if subtrees are used)
1470 * exact_match == true means we try to find fn with exact match of
1471 * the passed in prefix addr
1472 * exact_match == false means we try to find fn with longest prefix
1473 * match of the passed in prefix addr. This is useful for finding fn
1474 * for cached route as it will be stored in the exception table under
1475 * the node with longest prefix length.
1476 */
1477
1478
1479 static struct fib6_node *fib6_locate_1(struct fib6_node *root,
1480 const struct in6_addr *addr,
1481 int plen, int offset,
1482 bool exact_match)
1483 {
1484 struct fib6_node *fn, *prev = NULL;
1485
1486 for (fn = root; fn ; ) {
1487 struct fib6_info *leaf = rcu_dereference(fn->leaf);
1488 struct rt6key *key;
1489
1490 /* This node is being deleted */
1491 if (!leaf) {
1492 if (plen <= fn->fn_bit)
1493 goto out;
1494 else
1495 goto next;
1496 }
1497
1498 key = (struct rt6key *)((u8 *)leaf + offset);
1499
1500 /*
1501 * Prefix match
1502 */
1503 if (plen < fn->fn_bit ||
1504 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
1505 goto out;
1506
1507 if (plen == fn->fn_bit)
1508 return fn;
1509
1510 prev = fn;
1511
1512 next:
1513 /*
1514 * We have more bits to go
1515 */
1516 if (addr_bit_set(addr, fn->fn_bit))
1517 fn = rcu_dereference(fn->right);
1518 else
1519 fn = rcu_dereference(fn->left);
1520 }
1521 out:
1522 if (exact_match)
1523 return NULL;
1524 else
1525 return prev;
1526 }
1527
1528 struct fib6_node *fib6_locate(struct fib6_node *root,
1529 const struct in6_addr *daddr, int dst_len,
1530 const struct in6_addr *saddr, int src_len,
1531 bool exact_match)
1532 {
1533 struct fib6_node *fn;
1534
1535 fn = fib6_locate_1(root, daddr, dst_len,
1536 offsetof(struct fib6_info, fib6_dst),
1537 exact_match);
1538
1539 #ifdef CONFIG_IPV6_SUBTREES
1540 if (src_len) {
1541 WARN_ON(saddr == NULL);
1542 if (fn) {
1543 struct fib6_node *subtree = FIB6_SUBTREE(fn);
1544
1545 if (subtree) {
1546 fn = fib6_locate_1(subtree, saddr, src_len,
1547 offsetof(struct fib6_info, fib6_src),
1548 exact_match);
1549 }
1550 }
1551 }
1552 #endif
1553
1554 if (fn && fn->fn_flags & RTN_RTINFO)
1555 return fn;
1556
1557 return NULL;
1558 }
1559
1560
1561 /*
1562 * Deletion
1563 *
1564 */
1565
1566 static struct fib6_info *fib6_find_prefix(struct net *net,
1567 struct fib6_table *table,
1568 struct fib6_node *fn)
1569 {
1570 struct fib6_node *child_left, *child_right;
1571
1572 if (fn->fn_flags & RTN_ROOT)
1573 return net->ipv6.fib6_null_entry;
1574
1575 while (fn) {
1576 child_left = rcu_dereference_protected(fn->left,
1577 lockdep_is_held(&table->tb6_lock));
1578 child_right = rcu_dereference_protected(fn->right,
1579 lockdep_is_held(&table->tb6_lock));
1580 if (child_left)
1581 return rcu_dereference_protected(child_left->leaf,
1582 lockdep_is_held(&table->tb6_lock));
1583 if (child_right)
1584 return rcu_dereference_protected(child_right->leaf,
1585 lockdep_is_held(&table->tb6_lock));
1586
1587 fn = FIB6_SUBTREE(fn);
1588 }
1589 return NULL;
1590 }
1591
1592 /*
1593 * Called to trim the tree of intermediate nodes when possible. "fn"
1594 * is the node we want to try and remove.
1595 * Need to own table->tb6_lock
1596 */
1597
1598 static struct fib6_node *fib6_repair_tree(struct net *net,
1599 struct fib6_table *table,
1600 struct fib6_node *fn)
1601 {
1602 int children;
1603 int nstate;
1604 struct fib6_node *child;
1605 struct fib6_walker *w;
1606 int iter = 0;
1607
1608 /* Set fn->leaf to null_entry for root node. */
1609 if (fn->fn_flags & RTN_TL_ROOT) {
1610 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry);
1611 return fn;
1612 }
1613
1614 for (;;) {
1615 struct fib6_node *fn_r = rcu_dereference_protected(fn->right,
1616 lockdep_is_held(&table->tb6_lock));
1617 struct fib6_node *fn_l = rcu_dereference_protected(fn->left,
1618 lockdep_is_held(&table->tb6_lock));
1619 struct fib6_node *pn = rcu_dereference_protected(fn->parent,
1620 lockdep_is_held(&table->tb6_lock));
1621 struct fib6_node *pn_r = rcu_dereference_protected(pn->right,
1622 lockdep_is_held(&table->tb6_lock));
1623 struct fib6_node *pn_l = rcu_dereference_protected(pn->left,
1624 lockdep_is_held(&table->tb6_lock));
1625 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf,
1626 lockdep_is_held(&table->tb6_lock));
1627 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf,
1628 lockdep_is_held(&table->tb6_lock));
1629 struct fib6_info *new_fn_leaf;
1630
1631 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1632 iter++;
1633
1634 WARN_ON(fn->fn_flags & RTN_RTINFO);
1635 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1636 WARN_ON(fn_leaf);
1637
1638 children = 0;
1639 child = NULL;
1640 if (fn_r)
1641 child = fn_r, children |= 1;
1642 if (fn_l)
1643 child = fn_l, children |= 2;
1644
1645 if (children == 3 || FIB6_SUBTREE(fn)
1646 #ifdef CONFIG_IPV6_SUBTREES
1647 /* Subtree root (i.e. fn) may have one child */
1648 || (children && fn->fn_flags & RTN_ROOT)
1649 #endif
1650 ) {
1651 new_fn_leaf = fib6_find_prefix(net, table, fn);
1652 #if RT6_DEBUG >= 2
1653 if (!new_fn_leaf) {
1654 WARN_ON(!new_fn_leaf);
1655 new_fn_leaf = net->ipv6.fib6_null_entry;
1656 }
1657 #endif
1658 fib6_info_hold(new_fn_leaf);
1659 rcu_assign_pointer(fn->leaf, new_fn_leaf);
1660 return pn;
1661 }
1662
1663 #ifdef CONFIG_IPV6_SUBTREES
1664 if (FIB6_SUBTREE(pn) == fn) {
1665 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1666 RCU_INIT_POINTER(pn->subtree, NULL);
1667 nstate = FWS_L;
1668 } else {
1669 WARN_ON(fn->fn_flags & RTN_ROOT);
1670 #endif
1671 if (pn_r == fn)
1672 rcu_assign_pointer(pn->right, child);
1673 else if (pn_l == fn)
1674 rcu_assign_pointer(pn->left, child);
1675 #if RT6_DEBUG >= 2
1676 else
1677 WARN_ON(1);
1678 #endif
1679 if (child)
1680 rcu_assign_pointer(child->parent, pn);
1681 nstate = FWS_R;
1682 #ifdef CONFIG_IPV6_SUBTREES
1683 }
1684 #endif
1685
1686 read_lock(&net->ipv6.fib6_walker_lock);
1687 FOR_WALKERS(net, w) {
1688 if (!child) {
1689 if (w->node == fn) {
1690 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1691 w->node = pn;
1692 w->state = nstate;
1693 }
1694 } else {
1695 if (w->node == fn) {
1696 w->node = child;
1697 if (children&2) {
1698 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1699 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT;
1700 } else {
1701 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1702 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT;
1703 }
1704 }
1705 }
1706 }
1707 read_unlock(&net->ipv6.fib6_walker_lock);
1708
1709 node_free(net, fn);
1710 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
1711 return pn;
1712
1713 RCU_INIT_POINTER(pn->leaf, NULL);
1714 fib6_info_release(pn_leaf);
1715 fn = pn;
1716 }
1717 }
1718
1719 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
1720 struct fib6_info __rcu **rtp, struct nl_info *info)
1721 {
1722 struct fib6_walker *w;
1723 struct fib6_info *rt = rcu_dereference_protected(*rtp,
1724 lockdep_is_held(&table->tb6_lock));
1725 struct net *net = info->nl_net;
1726
1727 RT6_TRACE("fib6_del_route\n");
1728
1729 /* Unlink it */
1730 *rtp = rt->fib6_next;
1731 rt->fib6_node = NULL;
1732 net->ipv6.rt6_stats->fib_rt_entries--;
1733 net->ipv6.rt6_stats->fib_discarded_routes++;
1734
1735 /* Flush all cached dst in exception table */
1736 rt6_flush_exceptions(rt);
1737
1738 /* Reset round-robin state, if necessary */
1739 if (rcu_access_pointer(fn->rr_ptr) == rt)
1740 fn->rr_ptr = NULL;
1741
1742 /* Remove this entry from other siblings */
1743 if (rt->fib6_nsiblings) {
1744 struct fib6_info *sibling, *next_sibling;
1745
1746 list_for_each_entry_safe(sibling, next_sibling,
1747 &rt->fib6_siblings, fib6_siblings)
1748 sibling->fib6_nsiblings--;
1749 rt->fib6_nsiblings = 0;
1750 list_del_init(&rt->fib6_siblings);
1751 rt6_multipath_rebalance(next_sibling);
1752 }
1753
1754 /* Adjust walkers */
1755 read_lock(&net->ipv6.fib6_walker_lock);
1756 FOR_WALKERS(net, w) {
1757 if (w->state == FWS_C && w->leaf == rt) {
1758 RT6_TRACE("walker %p adjusted by delroute\n", w);
1759 w->leaf = rcu_dereference_protected(rt->fib6_next,
1760 lockdep_is_held(&table->tb6_lock));
1761 if (!w->leaf)
1762 w->state = FWS_U;
1763 }
1764 }
1765 read_unlock(&net->ipv6.fib6_walker_lock);
1766
1767 /* If it was last route, call fib6_repair_tree() to:
1768 * 1. For root node, put back null_entry as how the table was created.
1769 * 2. For other nodes, expunge its radix tree node.
1770 */
1771 if (!rcu_access_pointer(fn->leaf)) {
1772 if (!(fn->fn_flags & RTN_TL_ROOT)) {
1773 fn->fn_flags &= ~RTN_RTINFO;
1774 net->ipv6.rt6_stats->fib_route_nodes--;
1775 }
1776 fn = fib6_repair_tree(net, table, fn);
1777 }
1778
1779 fib6_purge_rt(rt, fn, net);
1780
1781 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL);
1782 if (!info->skip_notify)
1783 inet6_rt_notify(RTM_DELROUTE, rt, info, 0);
1784 fib6_info_release(rt);
1785 }
1786
1787 /* Need to own table->tb6_lock */
1788 int fib6_del(struct fib6_info *rt, struct nl_info *info)
1789 {
1790 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node,
1791 lockdep_is_held(&rt->fib6_table->tb6_lock));
1792 struct fib6_table *table = rt->fib6_table;
1793 struct net *net = info->nl_net;
1794 struct fib6_info __rcu **rtp;
1795 struct fib6_info __rcu **rtp_next;
1796
1797 if (!fn || rt == net->ipv6.fib6_null_entry)
1798 return -ENOENT;
1799
1800 WARN_ON(!(fn->fn_flags & RTN_RTINFO));
1801
1802 /*
1803 * Walk the leaf entries looking for ourself
1804 */
1805
1806 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) {
1807 struct fib6_info *cur = rcu_dereference_protected(*rtp,
1808 lockdep_is_held(&table->tb6_lock));
1809 if (rt == cur) {
1810 fib6_del_route(table, fn, rtp, info);
1811 return 0;
1812 }
1813 rtp_next = &cur->fib6_next;
1814 }
1815 return -ENOENT;
1816 }
1817
1818 /*
1819 * Tree traversal function.
1820 *
1821 * Certainly, it is not interrupt safe.
1822 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1823 * It means, that we can modify tree during walking
1824 * and use this function for garbage collection, clone pruning,
1825 * cleaning tree when a device goes down etc. etc.
1826 *
1827 * It guarantees that every node will be traversed,
1828 * and that it will be traversed only once.
1829 *
1830 * Callback function w->func may return:
1831 * 0 -> continue walking.
1832 * positive value -> walking is suspended (used by tree dumps,
1833 * and probably by gc, if it will be split to several slices)
1834 * negative value -> terminate walking.
1835 *
1836 * The function itself returns:
1837 * 0 -> walk is complete.
1838 * >0 -> walk is incomplete (i.e. suspended)
1839 * <0 -> walk is terminated by an error.
1840 *
1841 * This function is called with tb6_lock held.
1842 */
1843
1844 static int fib6_walk_continue(struct fib6_walker *w)
1845 {
1846 struct fib6_node *fn, *pn, *left, *right;
1847
1848 /* w->root should always be table->tb6_root */
1849 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT));
1850
1851 for (;;) {
1852 fn = w->node;
1853 if (!fn)
1854 return 0;
1855
1856 switch (w->state) {
1857 #ifdef CONFIG_IPV6_SUBTREES
1858 case FWS_S:
1859 if (FIB6_SUBTREE(fn)) {
1860 w->node = FIB6_SUBTREE(fn);
1861 continue;
1862 }
1863 w->state = FWS_L;
1864 #endif
1865 /* fall through */
1866 case FWS_L:
1867 left = rcu_dereference_protected(fn->left, 1);
1868 if (left) {
1869 w->node = left;
1870 w->state = FWS_INIT;
1871 continue;
1872 }
1873 w->state = FWS_R;
1874 /* fall through */
1875 case FWS_R:
1876 right = rcu_dereference_protected(fn->right, 1);
1877 if (right) {
1878 w->node = right;
1879 w->state = FWS_INIT;
1880 continue;
1881 }
1882 w->state = FWS_C;
1883 w->leaf = rcu_dereference_protected(fn->leaf, 1);
1884 /* fall through */
1885 case FWS_C:
1886 if (w->leaf && fn->fn_flags & RTN_RTINFO) {
1887 int err;
1888
1889 if (w->skip) {
1890 w->skip--;
1891 goto skip;
1892 }
1893
1894 err = w->func(w);
1895 if (err)
1896 return err;
1897
1898 w->count++;
1899 continue;
1900 }
1901 skip:
1902 w->state = FWS_U;
1903 /* fall through */
1904 case FWS_U:
1905 if (fn == w->root)
1906 return 0;
1907 pn = rcu_dereference_protected(fn->parent, 1);
1908 left = rcu_dereference_protected(pn->left, 1);
1909 right = rcu_dereference_protected(pn->right, 1);
1910 w->node = pn;
1911 #ifdef CONFIG_IPV6_SUBTREES
1912 if (FIB6_SUBTREE(pn) == fn) {
1913 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1914 w->state = FWS_L;
1915 continue;
1916 }
1917 #endif
1918 if (left == fn) {
1919 w->state = FWS_R;
1920 continue;
1921 }
1922 if (right == fn) {
1923 w->state = FWS_C;
1924 w->leaf = rcu_dereference_protected(w->node->leaf, 1);
1925 continue;
1926 }
1927 #if RT6_DEBUG >= 2
1928 WARN_ON(1);
1929 #endif
1930 }
1931 }
1932 }
1933
1934 static int fib6_walk(struct net *net, struct fib6_walker *w)
1935 {
1936 int res;
1937
1938 w->state = FWS_INIT;
1939 w->node = w->root;
1940
1941 fib6_walker_link(net, w);
1942 res = fib6_walk_continue(w);
1943 if (res <= 0)
1944 fib6_walker_unlink(net, w);
1945 return res;
1946 }
1947
1948 static int fib6_clean_node(struct fib6_walker *w)
1949 {
1950 int res;
1951 struct fib6_info *rt;
1952 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w);
1953 struct nl_info info = {
1954 .nl_net = c->net,
1955 };
1956
1957 if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
1958 w->node->fn_sernum != c->sernum)
1959 w->node->fn_sernum = c->sernum;
1960
1961 if (!c->func) {
1962 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE);
1963 w->leaf = NULL;
1964 return 0;
1965 }
1966
1967 for_each_fib6_walker_rt(w) {
1968 res = c->func(rt, c->arg);
1969 if (res == -1) {
1970 w->leaf = rt;
1971 res = fib6_del(rt, &info);
1972 if (res) {
1973 #if RT6_DEBUG >= 2
1974 pr_debug("%s: del failed: rt=%p@%p err=%d\n",
1975 __func__, rt,
1976 rcu_access_pointer(rt->fib6_node),
1977 res);
1978 #endif
1979 continue;
1980 }
1981 return 0;
1982 } else if (res == -2) {
1983 if (WARN_ON(!rt->fib6_nsiblings))
1984 continue;
1985 rt = list_last_entry(&rt->fib6_siblings,
1986 struct fib6_info, fib6_siblings);
1987 continue;
1988 }
1989 WARN_ON(res != 0);
1990 }
1991 w->leaf = rt;
1992 return 0;
1993 }
1994
1995 /*
1996 * Convenient frontend to tree walker.
1997 *
1998 * func is called on each route.
1999 * It may return -2 -> skip multipath route.
2000 * -1 -> delete this route.
2001 * 0 -> continue walking
2002 */
2003
2004 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
2005 int (*func)(struct fib6_info *, void *arg),
2006 int sernum, void *arg)
2007 {
2008 struct fib6_cleaner c;
2009
2010 c.w.root = root;
2011 c.w.func = fib6_clean_node;
2012 c.w.count = 0;
2013 c.w.skip = 0;
2014 c.func = func;
2015 c.sernum = sernum;
2016 c.arg = arg;
2017 c.net = net;
2018
2019 fib6_walk(net, &c.w);
2020 }
2021
2022 static void __fib6_clean_all(struct net *net,
2023 int (*func)(struct fib6_info *, void *),
2024 int sernum, void *arg)
2025 {
2026 struct fib6_table *table;
2027 struct hlist_head *head;
2028 unsigned int h;
2029
2030 rcu_read_lock();
2031 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
2032 head = &net->ipv6.fib_table_hash[h];
2033 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
2034 spin_lock_bh(&table->tb6_lock);
2035 fib6_clean_tree(net, &table->tb6_root,
2036 func, sernum, arg);
2037 spin_unlock_bh(&table->tb6_lock);
2038 }
2039 }
2040 rcu_read_unlock();
2041 }
2042
2043 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *),
2044 void *arg)
2045 {
2046 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg);
2047 }
2048
2049 static void fib6_flush_trees(struct net *net)
2050 {
2051 int new_sernum = fib6_new_sernum(net);
2052
2053 __fib6_clean_all(net, NULL, new_sernum, NULL);
2054 }
2055
2056 /*
2057 * Garbage collection
2058 */
2059
2060 static int fib6_age(struct fib6_info *rt, void *arg)
2061 {
2062 struct fib6_gc_args *gc_args = arg;
2063 unsigned long now = jiffies;
2064
2065 /*
2066 * check addrconf expiration here.
2067 * Routes are expired even if they are in use.
2068 */
2069
2070 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) {
2071 if (time_after(now, rt->expires)) {
2072 RT6_TRACE("expiring %p\n", rt);
2073 return -1;
2074 }
2075 gc_args->more++;
2076 }
2077
2078 /* Also age clones in the exception table.
2079 * Note, that clones are aged out
2080 * only if they are not in use now.
2081 */
2082 rt6_age_exceptions(rt, gc_args, now);
2083
2084 return 0;
2085 }
2086
2087 void fib6_run_gc(unsigned long expires, struct net *net, bool force)
2088 {
2089 struct fib6_gc_args gc_args;
2090 unsigned long now;
2091
2092 if (force) {
2093 spin_lock_bh(&net->ipv6.fib6_gc_lock);
2094 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) {
2095 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
2096 return;
2097 }
2098 gc_args.timeout = expires ? (int)expires :
2099 net->ipv6.sysctl.ip6_rt_gc_interval;
2100 gc_args.more = 0;
2101
2102 fib6_clean_all(net, fib6_age, &gc_args);
2103 now = jiffies;
2104 net->ipv6.ip6_rt_last_gc = now;
2105
2106 if (gc_args.more)
2107 mod_timer(&net->ipv6.ip6_fib_timer,
2108 round_jiffies(now
2109 + net->ipv6.sysctl.ip6_rt_gc_interval));
2110 else
2111 del_timer(&net->ipv6.ip6_fib_timer);
2112 spin_unlock_bh(&net->ipv6.fib6_gc_lock);
2113 }
2114
2115 static void fib6_gc_timer_cb(struct timer_list *t)
2116 {
2117 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer);
2118
2119 fib6_run_gc(0, arg, true);
2120 }
2121
2122 static int __net_init fib6_net_init(struct net *net)
2123 {
2124 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
2125 int err;
2126
2127 err = fib6_notifier_init(net);
2128 if (err)
2129 return err;
2130
2131 spin_lock_init(&net->ipv6.fib6_gc_lock);
2132 rwlock_init(&net->ipv6.fib6_walker_lock);
2133 INIT_LIST_HEAD(&net->ipv6.fib6_walkers);
2134 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0);
2135
2136 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
2137 if (!net->ipv6.rt6_stats)
2138 goto out_timer;
2139
2140 /* Avoid false sharing : Use at least a full cache line */
2141 size = max_t(size_t, size, L1_CACHE_BYTES);
2142
2143 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
2144 if (!net->ipv6.fib_table_hash)
2145 goto out_rt6_stats;
2146
2147 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
2148 GFP_KERNEL);
2149 if (!net->ipv6.fib6_main_tbl)
2150 goto out_fib_table_hash;
2151
2152 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
2153 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf,
2154 net->ipv6.fib6_null_entry);
2155 net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
2156 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
2157 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
2158
2159 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2160 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
2161 GFP_KERNEL);
2162 if (!net->ipv6.fib6_local_tbl)
2163 goto out_fib6_main_tbl;
2164 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
2165 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf,
2166 net->ipv6.fib6_null_entry);
2167 net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
2168 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
2169 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
2170 #endif
2171 fib6_tables_init(net);
2172
2173 return 0;
2174
2175 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2176 out_fib6_main_tbl:
2177 kfree(net->ipv6.fib6_main_tbl);
2178 #endif
2179 out_fib_table_hash:
2180 kfree(net->ipv6.fib_table_hash);
2181 out_rt6_stats:
2182 kfree(net->ipv6.rt6_stats);
2183 out_timer:
2184 fib6_notifier_exit(net);
2185 return -ENOMEM;
2186 }
2187
2188 static void fib6_net_exit(struct net *net)
2189 {
2190 unsigned int i;
2191
2192 del_timer_sync(&net->ipv6.ip6_fib_timer);
2193
2194 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) {
2195 struct hlist_head *head = &net->ipv6.fib_table_hash[i];
2196 struct hlist_node *tmp;
2197 struct fib6_table *tb;
2198
2199 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) {
2200 hlist_del(&tb->tb6_hlist);
2201 fib6_free_table(tb);
2202 }
2203 }
2204
2205 kfree(net->ipv6.fib_table_hash);
2206 kfree(net->ipv6.rt6_stats);
2207 fib6_notifier_exit(net);
2208 }
2209
2210 static struct pernet_operations fib6_net_ops = {
2211 .init = fib6_net_init,
2212 .exit = fib6_net_exit,
2213 };
2214
2215 int __init fib6_init(void)
2216 {
2217 int ret = -ENOMEM;
2218
2219 fib6_node_kmem = kmem_cache_create("fib6_nodes",
2220 sizeof(struct fib6_node),
2221 0, SLAB_HWCACHE_ALIGN,
2222 NULL);
2223 if (!fib6_node_kmem)
2224 goto out;
2225
2226 ret = register_pernet_subsys(&fib6_net_ops);
2227 if (ret)
2228 goto out_kmem_cache_create;
2229
2230 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL,
2231 inet6_dump_fib, 0);
2232 if (ret)
2233 goto out_unregister_subsys;
2234
2235 __fib6_flush_trees = fib6_flush_trees;
2236 out:
2237 return ret;
2238
2239 out_unregister_subsys:
2240 unregister_pernet_subsys(&fib6_net_ops);
2241 out_kmem_cache_create:
2242 kmem_cache_destroy(fib6_node_kmem);
2243 goto out;
2244 }
2245
2246 void fib6_gc_cleanup(void)
2247 {
2248 unregister_pernet_subsys(&fib6_net_ops);
2249 kmem_cache_destroy(fib6_node_kmem);
2250 }
2251
2252 #ifdef CONFIG_PROC_FS
2253 static int ipv6_route_seq_show(struct seq_file *seq, void *v)
2254 {
2255 struct fib6_info *rt = v;
2256 struct ipv6_route_iter *iter = seq->private;
2257 const struct net_device *dev;
2258
2259 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen);
2260
2261 #ifdef CONFIG_IPV6_SUBTREES
2262 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen);
2263 #else
2264 seq_puts(seq, "00000000000000000000000000000000 00 ");
2265 #endif
2266 if (rt->fib6_flags & RTF_GATEWAY)
2267 seq_printf(seq, "%pi6", &rt->fib6_nh.nh_gw);
2268 else
2269 seq_puts(seq, "00000000000000000000000000000000");
2270
2271 dev = rt->fib6_nh.nh_dev;
2272 seq_printf(seq, " %08x %08x %08x %08x %8s\n",
2273 rt->fib6_metric, atomic_read(&rt->fib6_ref), 0,
2274 rt->fib6_flags, dev ? dev->name : "");
2275 iter->w.leaf = NULL;
2276 return 0;
2277 }
2278
2279 static int ipv6_route_yield(struct fib6_walker *w)
2280 {
2281 struct ipv6_route_iter *iter = w->args;
2282
2283 if (!iter->skip)
2284 return 1;
2285
2286 do {
2287 iter->w.leaf = rcu_dereference_protected(
2288 iter->w.leaf->fib6_next,
2289 lockdep_is_held(&iter->tbl->tb6_lock));
2290 iter->skip--;
2291 if (!iter->skip && iter->w.leaf)
2292 return 1;
2293 } while (iter->w.leaf);
2294
2295 return 0;
2296 }
2297
2298 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter,
2299 struct net *net)
2300 {
2301 memset(&iter->w, 0, sizeof(iter->w));
2302 iter->w.func = ipv6_route_yield;
2303 iter->w.root = &iter->tbl->tb6_root;
2304 iter->w.state = FWS_INIT;
2305 iter->w.node = iter->w.root;
2306 iter->w.args = iter;
2307 iter->sernum = iter->w.root->fn_sernum;
2308 INIT_LIST_HEAD(&iter->w.lh);
2309 fib6_walker_link(net, &iter->w);
2310 }
2311
2312 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
2313 struct net *net)
2314 {
2315 unsigned int h;
2316 struct hlist_node *node;
2317
2318 if (tbl) {
2319 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1;
2320 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist));
2321 } else {
2322 h = 0;
2323 node = NULL;
2324 }
2325
2326 while (!node && h < FIB6_TABLE_HASHSZ) {
2327 node = rcu_dereference_bh(
2328 hlist_first_rcu(&net->ipv6.fib_table_hash[h++]));
2329 }
2330 return hlist_entry_safe(node, struct fib6_table, tb6_hlist);
2331 }
2332
2333 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter)
2334 {
2335 if (iter->sernum != iter->w.root->fn_sernum) {
2336 iter->sernum = iter->w.root->fn_sernum;
2337 iter->w.state = FWS_INIT;
2338 iter->w.node = iter->w.root;
2339 WARN_ON(iter->w.skip);
2340 iter->w.skip = iter->w.count;
2341 }
2342 }
2343
2344 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2345 {
2346 int r;
2347 struct fib6_info *n;
2348 struct net *net = seq_file_net(seq);
2349 struct ipv6_route_iter *iter = seq->private;
2350
2351 if (!v)
2352 goto iter_table;
2353
2354 n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next);
2355 if (n) {
2356 ++*pos;
2357 return n;
2358 }
2359
2360 iter_table:
2361 ipv6_route_check_sernum(iter);
2362 spin_lock_bh(&iter->tbl->tb6_lock);
2363 r = fib6_walk_continue(&iter->w);
2364 spin_unlock_bh(&iter->tbl->tb6_lock);
2365 if (r > 0) {
2366 if (v)
2367 ++*pos;
2368 return iter->w.leaf;
2369 } else if (r < 0) {
2370 fib6_walker_unlink(net, &iter->w);
2371 return NULL;
2372 }
2373 fib6_walker_unlink(net, &iter->w);
2374
2375 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
2376 if (!iter->tbl)
2377 return NULL;
2378
2379 ipv6_route_seq_setup_walk(iter, net);
2380 goto iter_table;
2381 }
2382
2383 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
2384 __acquires(RCU_BH)
2385 {
2386 struct net *net = seq_file_net(seq);
2387 struct ipv6_route_iter *iter = seq->private;
2388
2389 rcu_read_lock_bh();
2390 iter->tbl = ipv6_route_seq_next_table(NULL, net);
2391 iter->skip = *pos;
2392
2393 if (iter->tbl) {
2394 ipv6_route_seq_setup_walk(iter, net);
2395 return ipv6_route_seq_next(seq, NULL, pos);
2396 } else {
2397 return NULL;
2398 }
2399 }
2400
2401 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter)
2402 {
2403 struct fib6_walker *w = &iter->w;
2404 return w->node && !(w->state == FWS_U && w->node == w->root);
2405 }
2406
2407 static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
2408 __releases(RCU_BH)
2409 {
2410 struct net *net = seq_file_net(seq);
2411 struct ipv6_route_iter *iter = seq->private;
2412
2413 if (ipv6_route_iter_active(iter))
2414 fib6_walker_unlink(net, &iter->w);
2415
2416 rcu_read_unlock_bh();
2417 }
2418
2419 const struct seq_operations ipv6_route_seq_ops = {
2420 .start = ipv6_route_seq_start,
2421 .next = ipv6_route_seq_next,
2422 .stop = ipv6_route_seq_stop,
2423 .show = ipv6_route_seq_show
2424 };
2425 #endif /* CONFIG_PROC_FS */
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