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io_uring: don't count rqs failed after current one
[linux/fpc-iii.git] / net / ipv6 / ip6_fib.c
blob46ed567194761d32ea533c688955a052d1e58de4
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Linux INET6 implementation
4 * Forwarding Information Database
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Changes:
10 * Yuji SEKIYA @USAGI: Support default route on router node;
11 * remove ip6_null_entry from the top of
12 * routing table.
13 * Ville Nuorvala: Fixed routing subtrees.
14 */
15
16 #define pr_fmt(fmt) "IPv6: " fmt
17
18 #include <linux/errno.h>
19 #include <linux/types.h>
20 #include <linux/net.h>
21 #include <linux/route.h>
22 #include <linux/netdevice.h>
23 #include <linux/in6.h>
24 #include <linux/init.h>
25 #include <linux/list.h>
26 #include <linux/slab.h>
27
28 #include <net/ip.h>
29 #include <net/ipv6.h>
30 #include <net/ndisc.h>
31 #include <net/addrconf.h>
32 #include <net/lwtunnel.h>
33 #include <net/fib_notifier.h>
34
35 #include <net/ip6_fib.h>
36 #include <net/ip6_route.h>
37
38 static struct kmem_cache *fib6_node_kmem __read_mostly;
39
40 struct fib6_cleaner {
41 struct fib6_walker w;
42 struct net *net;
43 int (*func)(struct fib6_info *, void *arg);
44 int sernum;
45 void *arg;
46 bool skip_notify;
47 };
48
49 #ifdef CONFIG_IPV6_SUBTREES
50 #define FWS_INIT FWS_S
51 #else
52 #define FWS_INIT FWS_L
53 #endif
54
55 static struct fib6_info *fib6_find_prefix(struct net *net,
56 struct fib6_table *table,
57 struct fib6_node *fn);
58 static struct fib6_node *fib6_repair_tree(struct net *net,
59 struct fib6_table *table,
60 struct fib6_node *fn);
61 static int fib6_walk(struct net *net, struct fib6_walker *w);
62 static int fib6_walk_continue(struct fib6_walker *w);
63
64 /*
65 * A routing update causes an increase of the serial number on the
66 * affected subtree. This allows for cached routes to be asynchronously
67 * tested when modifications are made to the destination cache as a
68 * result of redirects, path MTU changes, etc.
69 */
70
71 static void fib6_gc_timer_cb(struct timer_list *t);
72
73 #define FOR_WALKERS(net, w) \
74 list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh)
75
76 static void fib6_walker_link(struct net *net, struct fib6_walker *w)
77 {
78 write_lock_bh(&net->ipv6.fib6_walker_lock);
79 list_add(&w->lh, &net->ipv6.fib6_walkers);
80 write_unlock_bh(&net->ipv6.fib6_walker_lock);
81 }
82
83 static void fib6_walker_unlink(struct net *net, struct fib6_walker *w)
84 {
85 write_lock_bh(&net->ipv6.fib6_walker_lock);
86 list_del(&w->lh);
87 write_unlock_bh(&net->ipv6.fib6_walker_lock);
88 }
89
90 static int fib6_new_sernum(struct net *net)
91 {
92 int new, old;
93
94 do {
95 old = atomic_read(&net->ipv6.fib6_sernum);
96 new = old < INT_MAX ? old + 1 : 1;
97 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum,
98 old, new) != old);
99 return new;
100 }
101
102 enum {
103 FIB6_NO_SERNUM_CHANGE = 0,
104 };
105
106 void fib6_update_sernum(struct net *net, struct fib6_info *f6i)
107 {
108 struct fib6_node *fn;
109
110 fn = rcu_dereference_protected(f6i->fib6_node,
111 lockdep_is_held(&f6i->fib6_table->tb6_lock));
112 if (fn)
113 fn->fn_sernum = fib6_new_sernum(net);
114 }
115
116 /*
117 * Auxiliary address test functions for the radix tree.
118 *
119 * These assume a 32bit processor (although it will work on
120 * 64bit processors)
121 */
122
123 /*
124 * test bit
125 */
126 #if defined(__LITTLE_ENDIAN)
127 # define BITOP_BE32_SWIZZLE (0x1F & ~7)
128 #else
129 # define BITOP_BE32_SWIZZLE 0
130 #endif
131
132 static __be32 addr_bit_set(const void *token, int fn_bit)
133 {
134 const __be32 *addr = token;
135 /*
136 * Here,
137 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
138 * is optimized version of
139 * htonl(1 << ((~fn_bit)&0x1F))
140 * See include/asm-generic/bitops/le.h.
141 */
142 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
143 addr[fn_bit >> 5];
144 }
145
146 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh)
147 {
148 struct fib6_info *f6i;
149 size_t sz = sizeof(*f6i);
150
151 if (with_fib6_nh)
152 sz += sizeof(struct fib6_nh);
153
154 f6i = kzalloc(sz, gfp_flags);
155 if (!f6i)
156 return NULL;
157
158 /* fib6_siblings is a union with nh_list, so this initializes both */
159 INIT_LIST_HEAD(&f6i->fib6_siblings);
160 refcount_set(&f6i->fib6_ref, 1);
161
162 return f6i;
163 }
164
165 void fib6_info_destroy_rcu(struct rcu_head *head)
166 {
167 struct fib6_info *f6i = container_of(head, struct fib6_info, rcu);
168
169 WARN_ON(f6i->fib6_node);
170
171 if (f6i->nh)
172 nexthop_put(f6i->nh);
173 else
174 fib6_nh_release(f6i->fib6_nh);
175
176 ip_fib_metrics_put(f6i->fib6_metrics);
177 kfree(f6i);
178 }
179 EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu);
180
181 static struct fib6_node *node_alloc(struct net *net)
182 {
183 struct fib6_node *fn;
184
185 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
186 if (fn)
187 net->ipv6.rt6_stats->fib_nodes++;
188
189 return fn;
190 }
191
192 static void node_free_immediate(struct net *net, struct fib6_node *fn)
193 {
194 kmem_cache_free(fib6_node_kmem, fn);
195 net->ipv6.rt6_stats->fib_nodes--;
196 }
197
198 static void node_free_rcu(struct rcu_head *head)
199 {
200 struct fib6_node *fn = container_of(head, struct fib6_node, rcu);
201
202 kmem_cache_free(fib6_node_kmem, fn);
203 }
204
205 static void node_free(struct net *net, struct fib6_node *fn)
206 {
207 call_rcu(&fn->rcu, node_free_rcu);
208 net->ipv6.rt6_stats->fib_nodes--;
209 }
210
211 static void fib6_free_table(struct fib6_table *table)
212 {
213 inetpeer_invalidate_tree(&table->tb6_peers);
214 kfree(table);
215 }
216
217 static void fib6_link_table(struct net *net, struct fib6_table *tb)
218 {
219 unsigned int h;
220
221 /*
222 * Initialize table lock at a single place to give lockdep a key,
223 * tables aren't visible prior to being linked to the list.
224 */
225 spin_lock_init(&tb->tb6_lock);
226 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
227
228 /*
229 * No protection necessary, this is the only list mutatation
230 * operation, tables never disappear once they exist.
231 */
232 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
233 }
234
235 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
236
237 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
238 {
239 struct fib6_table *table;
240
241 table = kzalloc(sizeof(*table), GFP_ATOMIC);
242 if (table) {
243 table->tb6_id = id;
244 rcu_assign_pointer(table->tb6_root.leaf,
245 net->ipv6.fib6_null_entry);
246 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
247 inet_peer_base_init(&table->tb6_peers);
248 }
249
250 return table;
251 }
252
253 struct fib6_table *fib6_new_table(struct net *net, u32 id)
254 {
255 struct fib6_table *tb;
256
257 if (id == 0)
258 id = RT6_TABLE_MAIN;
259 tb = fib6_get_table(net, id);
260 if (tb)
261 return tb;
262
263 tb = fib6_alloc_table(net, id);
264 if (tb)
265 fib6_link_table(net, tb);
266
267 return tb;
268 }
269 EXPORT_SYMBOL_GPL(fib6_new_table);
270
271 struct fib6_table *fib6_get_table(struct net *net, u32 id)
272 {
273 struct fib6_table *tb;
274 struct hlist_head *head;
275 unsigned int h;
276
277 if (id == 0)
278 id = RT6_TABLE_MAIN;
279 h = id & (FIB6_TABLE_HASHSZ - 1);
280 rcu_read_lock();
281 head = &net->ipv6.fib_table_hash[h];
282 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
283 if (tb->tb6_id == id) {
284 rcu_read_unlock();
285 return tb;
286 }
287 }
288 rcu_read_unlock();
289
290 return NULL;
291 }
292 EXPORT_SYMBOL_GPL(fib6_get_table);
293
294 static void __net_init fib6_tables_init(struct net *net)
295 {
296 fib6_link_table(net, net->ipv6.fib6_main_tbl);
297 fib6_link_table(net, net->ipv6.fib6_local_tbl);
298 }
299 #else
300
301 struct fib6_table *fib6_new_table(struct net *net, u32 id)
302 {
303 return fib6_get_table(net, id);
304 }
305
306 struct fib6_table *fib6_get_table(struct net *net, u32 id)
307 {
308 return net->ipv6.fib6_main_tbl;
309 }
310
311 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
312 const struct sk_buff *skb,
313 int flags, pol_lookup_t lookup)
314 {
315 struct rt6_info *rt;
316
317 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
318 if (rt->dst.error == -EAGAIN) {
319 ip6_rt_put_flags(rt, flags);
320 rt = net->ipv6.ip6_null_entry;
321 if (!(flags & RT6_LOOKUP_F_DST_NOREF))
322 dst_hold(&rt->dst);
323 }
324
325 return &rt->dst;
326 }
327
328 /* called with rcu lock held; no reference taken on fib6_info */
329 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
330 struct fib6_result *res, int flags)
331 {
332 return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6,
333 res, flags);
334 }
335
336 static void __net_init fib6_tables_init(struct net *net)
337 {
338 fib6_link_table(net, net->ipv6.fib6_main_tbl);
339 }
340
341 #endif
342
343 unsigned int fib6_tables_seq_read(struct net *net)
344 {
345 unsigned int h, fib_seq = 0;
346
347 rcu_read_lock();
348 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
349 struct hlist_head *head = &net->ipv6.fib_table_hash[h];
350 struct fib6_table *tb;
351
352 hlist_for_each_entry_rcu(tb, head, tb6_hlist)
353 fib_seq += tb->fib_seq;
354 }
355 rcu_read_unlock();
356
357 return fib_seq;
358 }
359
360 static int call_fib6_entry_notifier(struct notifier_block *nb,
361 enum fib_event_type event_type,
362 struct fib6_info *rt,
363 struct netlink_ext_ack *extack)
364 {
365 struct fib6_entry_notifier_info info = {
366 .info.extack = extack,
367 .rt = rt,
368 };
369
370 return call_fib6_notifier(nb, event_type, &info.info);
371 }
372
373 static int call_fib6_multipath_entry_notifier(struct notifier_block *nb,
374 enum fib_event_type event_type,
375 struct fib6_info *rt,
376 unsigned int nsiblings,
377 struct netlink_ext_ack *extack)
378 {
379 struct fib6_entry_notifier_info info = {
380 .info.extack = extack,
381 .rt = rt,
382 .nsiblings = nsiblings,
383 };
384
385 return call_fib6_notifier(nb, event_type, &info.info);
386 }
387
388 int call_fib6_entry_notifiers(struct net *net,
389 enum fib_event_type event_type,
390 struct fib6_info *rt,
391 struct netlink_ext_ack *extack)
392 {
393 struct fib6_entry_notifier_info info = {
394 .info.extack = extack,
395 .rt = rt,
396 };
397
398 rt->fib6_table->fib_seq++;
399 return call_fib6_notifiers(net, event_type, &info.info);
400 }
401
402 int call_fib6_multipath_entry_notifiers(struct net *net,
403 enum fib_event_type event_type,
404 struct fib6_info *rt,
405 unsigned int nsiblings,
406 struct netlink_ext_ack *extack)
407 {
408 struct fib6_entry_notifier_info info = {
409 .info.extack = extack,
410 .rt = rt,
411 .nsiblings = nsiblings,
412 };
413
414 rt->fib6_table->fib_seq++;
415 return call_fib6_notifiers(net, event_type, &info.info);
416 }
417
418 int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt)
419 {
420 struct fib6_entry_notifier_info info = {
421 .rt = rt,
422 .nsiblings = rt->fib6_nsiblings,
423 };
424
425 rt->fib6_table->fib_seq++;
426 return call_fib6_notifiers(net, FIB_EVENT_ENTRY_REPLACE, &info.info);
427 }
428
429 struct fib6_dump_arg {
430 struct net *net;
431 struct notifier_block *nb;
432 struct netlink_ext_ack *extack;
433 };
434
435 static int fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg)
436 {
437 enum fib_event_type fib_event = FIB_EVENT_ENTRY_REPLACE;
438 int err;
439
440 if (!rt || rt == arg->net->ipv6.fib6_null_entry)
441 return 0;
442
443 if (rt->fib6_nsiblings)
444 err = call_fib6_multipath_entry_notifier(arg->nb, fib_event,
445 rt,
446 rt->fib6_nsiblings,
447 arg->extack);
448 else
449 err = call_fib6_entry_notifier(arg->nb, fib_event, rt,
450 arg->extack);
451
452 return err;
453 }
454
455 static int fib6_node_dump(struct fib6_walker *w)
456 {
457 int err;
458
459 err = fib6_rt_dump(w->leaf, w->args);
460 w->leaf = NULL;
461 return err;
462 }
463
464 static int fib6_table_dump(struct net *net, struct fib6_table *tb,
465 struct fib6_walker *w)
466 {
467 int err;
468
469 w->root = &tb->tb6_root;
470 spin_lock_bh(&tb->tb6_lock);
471 err = fib6_walk(net, w);
472 spin_unlock_bh(&tb->tb6_lock);
473 return err;
474 }
475
476 /* Called with rcu_read_lock() */
477 int fib6_tables_dump(struct net *net, struct notifier_block *nb,
478 struct netlink_ext_ack *extack)
479 {
480 struct fib6_dump_arg arg;
481 struct fib6_walker *w;
482 unsigned int h;
483 int err = 0;
484
485 w = kzalloc(sizeof(*w), GFP_ATOMIC);
486 if (!w)
487 return -ENOMEM;
488
489 w->func = fib6_node_dump;
490 arg.net = net;
491 arg.nb = nb;
492 arg.extack = extack;
493 w->args = &arg;
494
495 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
496 struct hlist_head *head = &net->ipv6.fib_table_hash[h];
497 struct fib6_table *tb;
498
499 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
500 err = fib6_table_dump(net, tb, w);
501 if (err < 0)
502 goto out;
503 }
504 }
505
506 out:
507 kfree(w);
508
509 return err;
510 }
511
512 static int fib6_dump_node(struct fib6_walker *w)
513 {
514 int res;
515 struct fib6_info *rt;
516
517 for_each_fib6_walker_rt(w) {
518 res = rt6_dump_route(rt, w->args, w->skip_in_node);
519 if (res >= 0) {
520 /* Frame is full, suspend walking */
521 w->leaf = rt;
522
523 /* We'll restart from this node, so if some routes were
524 * already dumped, skip them next time.
525 */
526 w->skip_in_node += res;
527
528 return 1;
529 }
530 w->skip_in_node = 0;
531
532 /* Multipath routes are dumped in one route with the
533 * RTA_MULTIPATH attribute. Jump 'rt' to point to the
534 * last sibling of this route (no need to dump the
535 * sibling routes again)
536 */
537 if (rt->fib6_nsiblings)
538 rt = list_last_entry(&rt->fib6_siblings,
539 struct fib6_info,
540 fib6_siblings);
541 }
542 w->leaf = NULL;
543 return 0;
544 }
545
546 static void fib6_dump_end(struct netlink_callback *cb)
547 {
548 struct net *net = sock_net(cb->skb->sk);
549 struct fib6_walker *w = (void *)cb->args[2];
550
551 if (w) {
552 if (cb->args[4]) {
553 cb->args[4] = 0;
554 fib6_walker_unlink(net, w);
555 }
556 cb->args[2] = 0;
557 kfree(w);
558 }
559 cb->done = (void *)cb->args[3];
560 cb->args[1] = 3;
561 }
562
563 static int fib6_dump_done(struct netlink_callback *cb)
564 {
565 fib6_dump_end(cb);
566 return cb->done ? cb->done(cb) : 0;
567 }
568
569 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
570 struct netlink_callback *cb)
571 {
572 struct net *net = sock_net(skb->sk);
573 struct fib6_walker *w;
574 int res;
575
576 w = (void *)cb->args[2];
577 w->root = &table->tb6_root;
578
579 if (cb->args[4] == 0) {
580 w->count = 0;
581 w->skip = 0;
582 w->skip_in_node = 0;
583
584 spin_lock_bh(&table->tb6_lock);
585 res = fib6_walk(net, w);
586 spin_unlock_bh(&table->tb6_lock);
587 if (res > 0) {
588 cb->args[4] = 1;
589 cb->args[5] = w->root->fn_sernum;
590 }
591 } else {
592 if (cb->args[5] != w->root->fn_sernum) {
593 /* Begin at the root if the tree changed */
594 cb->args[5] = w->root->fn_sernum;
595 w->state = FWS_INIT;
596 w->node = w->root;
597 w->skip = w->count;
598 w->skip_in_node = 0;
599 } else
600 w->skip = 0;
601
602 spin_lock_bh(&table->tb6_lock);
603 res = fib6_walk_continue(w);
604 spin_unlock_bh(&table->tb6_lock);
605 if (res <= 0) {
606 fib6_walker_unlink(net, w);
607 cb->args[4] = 0;
608 }
609 }
610
611 return res;
612 }
613
614 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
615 {
616 struct rt6_rtnl_dump_arg arg = { .filter.dump_exceptions = true,
617 .filter.dump_routes = true };
618 const struct nlmsghdr *nlh = cb->nlh;
619 struct net *net = sock_net(skb->sk);
620 unsigned int h, s_h;
621 unsigned int e = 0, s_e;
622 struct fib6_walker *w;
623 struct fib6_table *tb;
624 struct hlist_head *head;
625 int res = 0;
626
627 if (cb->strict_check) {
628 int err;
629
630 err = ip_valid_fib_dump_req(net, nlh, &arg.filter, cb);
631 if (err < 0)
632 return err;
633 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
634 struct rtmsg *rtm = nlmsg_data(nlh);
635
636 if (rtm->rtm_flags & RTM_F_PREFIX)
637 arg.filter.flags = RTM_F_PREFIX;
638 }
639
640 w = (void *)cb->args[2];
641 if (!w) {
642 /* New dump:
643 *
644 * 1. hook callback destructor.
645 */
646 cb->args[3] = (long)cb->done;
647 cb->done = fib6_dump_done;
648
649 /*
650 * 2. allocate and initialize walker.
651 */
652 w = kzalloc(sizeof(*w), GFP_ATOMIC);
653 if (!w)
654 return -ENOMEM;
655 w->func = fib6_dump_node;
656 cb->args[2] = (long)w;
657 }
658
659 arg.skb = skb;
660 arg.cb = cb;
661 arg.net = net;
662 w->args = &arg;
663
664 if (arg.filter.table_id) {
665 tb = fib6_get_table(net, arg.filter.table_id);
666 if (!tb) {
667 if (arg.filter.dump_all_families)
668 goto out;
669
670 NL_SET_ERR_MSG_MOD(cb->extack, "FIB table does not exist");
671 return -ENOENT;
672 }
673
674 if (!cb->args[0]) {
675 res = fib6_dump_table(tb, skb, cb);
676 if (!res)
677 cb->args[0] = 1;
678 }
679 goto out;
680 }
681
682 s_h = cb->args[0];
683 s_e = cb->args[1];
684
685 rcu_read_lock();
686 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
687 e = 0;
688 head = &net->ipv6.fib_table_hash[h];
689 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
690 if (e < s_e)
691 goto next;
692 res = fib6_dump_table(tb, skb, cb);
693 if (res != 0)
694 goto out_unlock;
695 next:
696 e++;
697 }
698 }
699 out_unlock:
700 rcu_read_unlock();
701 cb->args[1] = e;
702 cb->args[0] = h;
703 out:
704 res = res < 0 ? res : skb->len;
705 if (res <= 0)
706 fib6_dump_end(cb);
707 return res;
708 }
709
710 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val)
711 {
712 if (!f6i)
713 return;
714
715 if (f6i->fib6_metrics == &dst_default_metrics) {
716 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC);
717
718 if (!p)
719 return;
720
721 refcount_set(&p->refcnt, 1);
722 f6i->fib6_metrics = p;
723 }
724
725 f6i->fib6_metrics->metrics[metric - 1] = val;
726 }
727
728 /*
729 * Routing Table
730 *
731 * return the appropriate node for a routing tree "add" operation
732 * by either creating and inserting or by returning an existing
733 * node.
734 */
735
736 static struct fib6_node *fib6_add_1(struct net *net,
737 struct fib6_table *table,
738 struct fib6_node *root,
739 struct in6_addr *addr, int plen,
740 int offset, int allow_create,
741 int replace_required,
742 struct netlink_ext_ack *extack)
743 {
744 struct fib6_node *fn, *in, *ln;
745 struct fib6_node *pn = NULL;
746 struct rt6key *key;
747 int bit;
748 __be32 dir = 0;
749
750 RT6_TRACE("fib6_add_1\n");
751
752 /* insert node in tree */
753
754 fn = root;
755
756 do {
757 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
758 lockdep_is_held(&table->tb6_lock));
759 key = (struct rt6key *)((u8 *)leaf + offset);
760
761 /*
762 * Prefix match
763 */
764 if (plen < fn->fn_bit ||
765 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
766 if (!allow_create) {
767 if (replace_required) {
768 NL_SET_ERR_MSG(extack,
769 "Can not replace route - no match found");
770 pr_warn("Can't replace route, no match found\n");
771 return ERR_PTR(-ENOENT);
772 }
773 pr_warn("NLM_F_CREATE should be set when creating new route\n");
774 }
775 goto insert_above;
776 }
777
778 /*
779 * Exact match ?
780 */
781
782 if (plen == fn->fn_bit) {
783 /* clean up an intermediate node */
784 if (!(fn->fn_flags & RTN_RTINFO)) {
785 RCU_INIT_POINTER(fn->leaf, NULL);
786 fib6_info_release(leaf);
787 /* remove null_entry in the root node */
788 } else if (fn->fn_flags & RTN_TL_ROOT &&
789 rcu_access_pointer(fn->leaf) ==
790 net->ipv6.fib6_null_entry) {
791 RCU_INIT_POINTER(fn->leaf, NULL);
792 }
793
794 return fn;
795 }
796
797 /*
798 * We have more bits to go
799 */
800
801 /* Try to walk down on tree. */
802 dir = addr_bit_set(addr, fn->fn_bit);
803 pn = fn;
804 fn = dir ?
805 rcu_dereference_protected(fn->right,
806 lockdep_is_held(&table->tb6_lock)) :
807 rcu_dereference_protected(fn->left,
808 lockdep_is_held(&table->tb6_lock));
809 } while (fn);
810
811 if (!allow_create) {
812 /* We should not create new node because
813 * NLM_F_REPLACE was specified without NLM_F_CREATE
814 * I assume it is safe to require NLM_F_CREATE when
815 * REPLACE flag is used! Later we may want to remove the
816 * check for replace_required, because according
817 * to netlink specification, NLM_F_CREATE
818 * MUST be specified if new route is created.
819 * That would keep IPv6 consistent with IPv4
820 */
821 if (replace_required) {
822 NL_SET_ERR_MSG(extack,
823 "Can not replace route - no match found");
824 pr_warn("Can't replace route, no match found\n");
825 return ERR_PTR(-ENOENT);
826 }
827 pr_warn("NLM_F_CREATE should be set when creating new route\n");
828 }
829 /*
830 * We walked to the bottom of tree.
831 * Create new leaf node without children.
832 */
833
834 ln = node_alloc(net);
835
836 if (!ln)
837 return ERR_PTR(-ENOMEM);
838 ln->fn_bit = plen;
839 RCU_INIT_POINTER(ln->parent, pn);
840
841 if (dir)
842 rcu_assign_pointer(pn->right, ln);
843 else
844 rcu_assign_pointer(pn->left, ln);
845
846 return ln;
847
848
849 insert_above:
850 /*
851 * split since we don't have a common prefix anymore or
852 * we have a less significant route.
853 * we've to insert an intermediate node on the list
854 * this new node will point to the one we need to create
855 * and the current
856 */
857
858 pn = rcu_dereference_protected(fn->parent,
859 lockdep_is_held(&table->tb6_lock));
860
861 /* find 1st bit in difference between the 2 addrs.
862
863 See comment in __ipv6_addr_diff: bit may be an invalid value,
864 but if it is >= plen, the value is ignored in any case.
865 */
866
867 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr));
868
869 /*
870 * (intermediate)[in]
871 * / \
872 * (new leaf node)[ln] (old node)[fn]
873 */
874 if (plen > bit) {
875 in = node_alloc(net);
876 ln = node_alloc(net);
877
878 if (!in || !ln) {
879 if (in)
880 node_free_immediate(net, in);
881 if (ln)
882 node_free_immediate(net, ln);
883 return ERR_PTR(-ENOMEM);
884 }
885
886 /*
887 * new intermediate node.
888 * RTN_RTINFO will
889 * be off since that an address that chooses one of
890 * the branches would not match less specific routes
891 * in the other branch
892 */
893
894 in->fn_bit = bit;
895
896 RCU_INIT_POINTER(in->parent, pn);
897 in->leaf = fn->leaf;
898 fib6_info_hold(rcu_dereference_protected(in->leaf,
899 lockdep_is_held(&table->tb6_lock)));
900
901 /* update parent pointer */
902 if (dir)
903 rcu_assign_pointer(pn->right, in);
904 else
905 rcu_assign_pointer(pn->left, in);
906
907 ln->fn_bit = plen;
908
909 RCU_INIT_POINTER(ln->parent, in);
910 rcu_assign_pointer(fn->parent, in);
911
912 if (addr_bit_set(addr, bit)) {
913 rcu_assign_pointer(in->right, ln);
914 rcu_assign_pointer(in->left, fn);
915 } else {
916 rcu_assign_pointer(in->left, ln);
917 rcu_assign_pointer(in->right, fn);
918 }
919 } else { /* plen <= bit */
920
921 /*
922 * (new leaf node)[ln]
923 * / \
924 * (old node)[fn] NULL
925 */
926
927 ln = node_alloc(net);
928
929 if (!ln)
930 return ERR_PTR(-ENOMEM);
931
932 ln->fn_bit = plen;
933
934 RCU_INIT_POINTER(ln->parent, pn);
935
936 if (addr_bit_set(&key->addr, plen))
937 RCU_INIT_POINTER(ln->right, fn);
938 else
939 RCU_INIT_POINTER(ln->left, fn);
940
941 rcu_assign_pointer(fn->parent, ln);
942
943 if (dir)
944 rcu_assign_pointer(pn->right, ln);
945 else
946 rcu_assign_pointer(pn->left, ln);
947 }
948 return ln;
949 }
950
951 static void __fib6_drop_pcpu_from(struct fib6_nh *fib6_nh,
952 const struct fib6_info *match,
953 const struct fib6_table *table)
954 {
955 int cpu;
956
957 if (!fib6_nh->rt6i_pcpu)
958 return;
959
960 /* release the reference to this fib entry from
961 * all of its cached pcpu routes
962 */
963 for_each_possible_cpu(cpu) {
964 struct rt6_info **ppcpu_rt;
965 struct rt6_info *pcpu_rt;
966
967 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
968 pcpu_rt = *ppcpu_rt;
969
970 /* only dropping the 'from' reference if the cached route
971 * is using 'match'. The cached pcpu_rt->from only changes
972 * from a fib6_info to NULL (ip6_dst_destroy); it can never
973 * change from one fib6_info reference to another
974 */
975 if (pcpu_rt && rcu_access_pointer(pcpu_rt->from) == match) {
976 struct fib6_info *from;
977
978 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
979 fib6_info_release(from);
980 }
981 }
982 }
983
984 struct fib6_nh_pcpu_arg {
985 struct fib6_info *from;
986 const struct fib6_table *table;
987 };
988
989 static int fib6_nh_drop_pcpu_from(struct fib6_nh *nh, void *_arg)
990 {
991 struct fib6_nh_pcpu_arg *arg = _arg;
992
993 __fib6_drop_pcpu_from(nh, arg->from, arg->table);
994 return 0;
995 }
996
997 static void fib6_drop_pcpu_from(struct fib6_info *f6i,
998 const struct fib6_table *table)
999 {
1000 /* Make sure rt6_make_pcpu_route() wont add other percpu routes
1001 * while we are cleaning them here.
1002 */
1003 f6i->fib6_destroying = 1;
1004 mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */
1005
1006 if (f6i->nh) {
1007 struct fib6_nh_pcpu_arg arg = {
1008 .from = f6i,
1009 .table = table
1010 };
1011
1012 nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_drop_pcpu_from,
1013 &arg);
1014 } else {
1015 struct fib6_nh *fib6_nh;
1016
1017 fib6_nh = f6i->fib6_nh;
1018 __fib6_drop_pcpu_from(fib6_nh, f6i, table);
1019 }
1020 }
1021
1022 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,
1023 struct net *net)
1024 {
1025 struct fib6_table *table = rt->fib6_table;
1026
1027 fib6_drop_pcpu_from(rt, table);
1028
1029 if (rt->nh && !list_empty(&rt->nh_list))
1030 list_del_init(&rt->nh_list);
1031
1032 if (refcount_read(&rt->fib6_ref) != 1) {
1033 /* This route is used as dummy address holder in some split
1034 * nodes. It is not leaked, but it still holds other resources,
1035 * which must be released in time. So, scan ascendant nodes
1036 * and replace dummy references to this route with references
1037 * to still alive ones.
1038 */
1039 while (fn) {
1040 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
1041 lockdep_is_held(&table->tb6_lock));
1042 struct fib6_info *new_leaf;
1043 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) {
1044 new_leaf = fib6_find_prefix(net, table, fn);
1045 fib6_info_hold(new_leaf);
1046
1047 rcu_assign_pointer(fn->leaf, new_leaf);
1048 fib6_info_release(rt);
1049 }
1050 fn = rcu_dereference_protected(fn->parent,
1051 lockdep_is_held(&table->tb6_lock));
1052 }
1053 }
1054 }
1055
1056 /*
1057 * Insert routing information in a node.
1058 */
1059
1060 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
1061 struct nl_info *info,
1062 struct netlink_ext_ack *extack)
1063 {
1064 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
1065 lockdep_is_held(&rt->fib6_table->tb6_lock));
1066 struct fib6_info *iter = NULL;
1067 struct fib6_info __rcu **ins;
1068 struct fib6_info __rcu **fallback_ins = NULL;
1069 int replace = (info->nlh &&
1070 (info->nlh->nlmsg_flags & NLM_F_REPLACE));
1071 int add = (!info->nlh ||
1072 (info->nlh->nlmsg_flags & NLM_F_CREATE));
1073 int found = 0;
1074 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
1075 bool notify_sibling_rt = false;
1076 u16 nlflags = NLM_F_EXCL;
1077 int err;
1078
1079 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND))
1080 nlflags |= NLM_F_APPEND;
1081
1082 ins = &fn->leaf;
1083
1084 for (iter = leaf; iter;
1085 iter = rcu_dereference_protected(iter->fib6_next,
1086 lockdep_is_held(&rt->fib6_table->tb6_lock))) {
1087 /*
1088 * Search for duplicates
1089 */
1090
1091 if (iter->fib6_metric == rt->fib6_metric) {
1092 /*
1093 * Same priority level
1094 */
1095 if (info->nlh &&
1096 (info->nlh->nlmsg_flags & NLM_F_EXCL))
1097 return -EEXIST;
1098
1099 nlflags &= ~NLM_F_EXCL;
1100 if (replace) {
1101 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) {
1102 found++;
1103 break;
1104 }
1105 fallback_ins = fallback_ins ?: ins;
1106 goto next_iter;
1107 }
1108
1109 if (rt6_duplicate_nexthop(iter, rt)) {
1110 if (rt->fib6_nsiblings)
1111 rt->fib6_nsiblings = 0;
1112 if (!(iter->fib6_flags & RTF_EXPIRES))
1113 return -EEXIST;
1114 if (!(rt->fib6_flags & RTF_EXPIRES))
1115 fib6_clean_expires(iter);
1116 else
1117 fib6_set_expires(iter, rt->expires);
1118
1119 if (rt->fib6_pmtu)
1120 fib6_metric_set(iter, RTAX_MTU,
1121 rt->fib6_pmtu);
1122 return -EEXIST;
1123 }
1124 /* If we have the same destination and the same metric,
1125 * but not the same gateway, then the route we try to
1126 * add is sibling to this route, increment our counter
1127 * of siblings, and later we will add our route to the
1128 * list.
1129 * Only static routes (which don't have flag
1130 * RTF_EXPIRES) are used for ECMPv6.
1131 *
1132 * To avoid long list, we only had siblings if the
1133 * route have a gateway.
1134 */
1135 if (rt_can_ecmp &&
1136 rt6_qualify_for_ecmp(iter))
1137 rt->fib6_nsiblings++;
1138 }
1139
1140 if (iter->fib6_metric > rt->fib6_metric)
1141 break;
1142
1143 next_iter:
1144 ins = &iter->fib6_next;
1145 }
1146
1147 if (fallback_ins && !found) {
1148 /* No matching route with same ecmp-able-ness found, replace
1149 * first matching route
1150 */
1151 ins = fallback_ins;
1152 iter = rcu_dereference_protected(*ins,
1153 lockdep_is_held(&rt->fib6_table->tb6_lock));
1154 found++;
1155 }
1156
1157 /* Reset round-robin state, if necessary */
1158 if (ins == &fn->leaf)
1159 fn->rr_ptr = NULL;
1160
1161 /* Link this route to others same route. */
1162 if (rt->fib6_nsiblings) {
1163 unsigned int fib6_nsiblings;
1164 struct fib6_info *sibling, *temp_sibling;
1165
1166 /* Find the first route that have the same metric */
1167 sibling = leaf;
1168 notify_sibling_rt = true;
1169 while (sibling) {
1170 if (sibling->fib6_metric == rt->fib6_metric &&
1171 rt6_qualify_for_ecmp(sibling)) {
1172 list_add_tail(&rt->fib6_siblings,
1173 &sibling->fib6_siblings);
1174 break;
1175 }
1176 sibling = rcu_dereference_protected(sibling->fib6_next,
1177 lockdep_is_held(&rt->fib6_table->tb6_lock));
1178 notify_sibling_rt = false;
1179 }
1180 /* For each sibling in the list, increment the counter of
1181 * siblings. BUG() if counters does not match, list of siblings
1182 * is broken!
1183 */
1184 fib6_nsiblings = 0;
1185 list_for_each_entry_safe(sibling, temp_sibling,
1186 &rt->fib6_siblings, fib6_siblings) {
1187 sibling->fib6_nsiblings++;
1188 BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings);
1189 fib6_nsiblings++;
1190 }
1191 BUG_ON(fib6_nsiblings != rt->fib6_nsiblings);
1192 rt6_multipath_rebalance(temp_sibling);
1193 }
1194
1195 /*
1196 * insert node
1197 */
1198 if (!replace) {
1199 if (!add)
1200 pr_warn("NLM_F_CREATE should be set when creating new route\n");
1201
1202 add:
1203 nlflags |= NLM_F_CREATE;
1204
1205 /* The route should only be notified if it is the first
1206 * route in the node or if it is added as a sibling
1207 * route to the first route in the node.
1208 */
1209 if (!info->skip_notify_kernel &&
1210 (notify_sibling_rt || ins == &fn->leaf)) {
1211 enum fib_event_type fib_event;
1212
1213 if (notify_sibling_rt)
1214 fib_event = FIB_EVENT_ENTRY_APPEND;
1215 else
1216 fib_event = FIB_EVENT_ENTRY_REPLACE;
1217 err = call_fib6_entry_notifiers(info->nl_net,
1218 fib_event, rt,
1219 extack);
1220 if (err) {
1221 struct fib6_info *sibling, *next_sibling;
1222
1223 /* If the route has siblings, then it first
1224 * needs to be unlinked from them.
1225 */
1226 if (!rt->fib6_nsiblings)
1227 return err;
1228
1229 list_for_each_entry_safe(sibling, next_sibling,
1230 &rt->fib6_siblings,
1231 fib6_siblings)
1232 sibling->fib6_nsiblings--;
1233 rt->fib6_nsiblings = 0;
1234 list_del_init(&rt->fib6_siblings);
1235 rt6_multipath_rebalance(next_sibling);
1236 return err;
1237 }
1238 }
1239
1240 rcu_assign_pointer(rt->fib6_next, iter);
1241 fib6_info_hold(rt);
1242 rcu_assign_pointer(rt->fib6_node, fn);
1243 rcu_assign_pointer(*ins, rt);
1244 if (!info->skip_notify)
1245 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
1246 info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
1247
1248 if (!(fn->fn_flags & RTN_RTINFO)) {
1249 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
1250 fn->fn_flags |= RTN_RTINFO;
1251 }
1252
1253 } else {
1254 int nsiblings;
1255
1256 if (!found) {
1257 if (add)
1258 goto add;
1259 pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
1260 return -ENOENT;
1261 }
1262
1263 if (!info->skip_notify_kernel && ins == &fn->leaf) {
1264 err = call_fib6_entry_notifiers(info->nl_net,
1265 FIB_EVENT_ENTRY_REPLACE,
1266 rt, extack);
1267 if (err)
1268 return err;
1269 }
1270
1271 fib6_info_hold(rt);
1272 rcu_assign_pointer(rt->fib6_node, fn);
1273 rt->fib6_next = iter->fib6_next;
1274 rcu_assign_pointer(*ins, rt);
1275 if (!info->skip_notify)
1276 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE);
1277 if (!(fn->fn_flags & RTN_RTINFO)) {
1278 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
1279 fn->fn_flags |= RTN_RTINFO;
1280 }
1281 nsiblings = iter->fib6_nsiblings;
1282 iter->fib6_node = NULL;
1283 fib6_purge_rt(iter, fn, info->nl_net);
1284 if (rcu_access_pointer(fn->rr_ptr) == iter)
1285 fn->rr_ptr = NULL;
1286 fib6_info_release(iter);
1287
1288 if (nsiblings) {
1289 /* Replacing an ECMP route, remove all siblings */
1290 ins = &rt->fib6_next;
1291 iter = rcu_dereference_protected(*ins,
1292 lockdep_is_held(&rt->fib6_table->tb6_lock));
1293 while (iter) {
1294 if (iter->fib6_metric > rt->fib6_metric)
1295 break;
1296 if (rt6_qualify_for_ecmp(iter)) {
1297 *ins = iter->fib6_next;
1298 iter->fib6_node = NULL;
1299 fib6_purge_rt(iter, fn, info->nl_net);
1300 if (rcu_access_pointer(fn->rr_ptr) == iter)
1301 fn->rr_ptr = NULL;
1302 fib6_info_release(iter);
1303 nsiblings--;
1304 info->nl_net->ipv6.rt6_stats->fib_rt_entries--;
1305 } else {
1306 ins = &iter->fib6_next;
1307 }
1308 iter = rcu_dereference_protected(*ins,
1309 lockdep_is_held(&rt->fib6_table->tb6_lock));
1310 }
1311 WARN_ON(nsiblings != 0);
1312 }
1313 }
1314
1315 return 0;
1316 }
1317
1318 static void fib6_start_gc(struct net *net, struct fib6_info *rt)
1319 {
1320 if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
1321 (rt->fib6_flags & RTF_EXPIRES))
1322 mod_timer(&net->ipv6.ip6_fib_timer,
1323 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
1324 }
1325
1326 void fib6_force_start_gc(struct net *net)
1327 {
1328 if (!timer_pending(&net->ipv6.ip6_fib_timer))
1329 mod_timer(&net->ipv6.ip6_fib_timer,
1330 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
1331 }
1332
1333 static void __fib6_update_sernum_upto_root(struct fib6_info *rt,
1334 int sernum)
1335 {
1336 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node,
1337 lockdep_is_held(&rt->fib6_table->tb6_lock));
1338
1339 /* paired with smp_rmb() in rt6_get_cookie_safe() */
1340 smp_wmb();
1341 while (fn) {
1342 fn->fn_sernum = sernum;
1343 fn = rcu_dereference_protected(fn->parent,
1344 lockdep_is_held(&rt->fib6_table->tb6_lock));
1345 }
1346 }
1347
1348 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt)
1349 {
1350 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net));
1351 }
1352
1353 /* allow ipv4 to update sernum via ipv6_stub */
1354 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i)
1355 {
1356 spin_lock_bh(&f6i->fib6_table->tb6_lock);
1357 fib6_update_sernum_upto_root(net, f6i);
1358 spin_unlock_bh(&f6i->fib6_table->tb6_lock);
1359 }
1360
1361 /*
1362 * Add routing information to the routing tree.
1363 * <destination addr>/<source addr>
1364 * with source addr info in sub-trees
1365 * Need to own table->tb6_lock
1366 */
1367
1368 int fib6_add(struct fib6_node *root, struct fib6_info *rt,
1369 struct nl_info *info, struct netlink_ext_ack *extack)
1370 {
1371 struct fib6_table *table = rt->fib6_table;
1372 struct fib6_node *fn, *pn = NULL;
1373 int err = -ENOMEM;
1374 int allow_create = 1;
1375 int replace_required = 0;
1376 int sernum = fib6_new_sernum(info->nl_net);
1377
1378 if (info->nlh) {
1379 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
1380 allow_create = 0;
1381 if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
1382 replace_required = 1;
1383 }
1384 if (!allow_create && !replace_required)
1385 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
1386
1387 fn = fib6_add_1(info->nl_net, table, root,
1388 &rt->fib6_dst.addr, rt->fib6_dst.plen,
1389 offsetof(struct fib6_info, fib6_dst), allow_create,
1390 replace_required, extack);
1391 if (IS_ERR(fn)) {
1392 err = PTR_ERR(fn);
1393 fn = NULL;
1394 goto out;
1395 }
1396
1397 pn = fn;
1398
1399 #ifdef CONFIG_IPV6_SUBTREES
1400 if (rt->fib6_src.plen) {
1401 struct fib6_node *sn;
1402
1403 if (!rcu_access_pointer(fn->subtree)) {
1404 struct fib6_node *sfn;
1405
1406 /*
1407 * Create subtree.
1408 *
1409 * fn[main tree]
1410 * |
1411 * sfn[subtree root]
1412 * \
1413 * sn[new leaf node]
1414 */
1415
1416 /* Create subtree root node */
1417 sfn = node_alloc(info->nl_net);
1418 if (!sfn)
1419 goto failure;
1420
1421 fib6_info_hold(info->nl_net->ipv6.fib6_null_entry);
1422 rcu_assign_pointer(sfn->leaf,
1423 info->nl_net->ipv6.fib6_null_entry);
1424 sfn->fn_flags = RTN_ROOT;
1425
1426 /* Now add the first leaf node to new subtree */
1427
1428 sn = fib6_add_1(info->nl_net, table, sfn,
1429 &rt->fib6_src.addr, rt->fib6_src.plen,
1430 offsetof(struct fib6_info, fib6_src),
1431 allow_create, replace_required, extack);
1432
1433 if (IS_ERR(sn)) {
1434 /* If it is failed, discard just allocated
1435 root, and then (in failure) stale node
1436 in main tree.
1437 */
1438 node_free_immediate(info->nl_net, sfn);
1439 err = PTR_ERR(sn);
1440 goto failure;
1441 }
1442
1443 /* Now link new subtree to main tree */
1444 rcu_assign_pointer(sfn->parent, fn);
1445 rcu_assign_pointer(fn->subtree, sfn);
1446 } else {
1447 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn),
1448 &rt->fib6_src.addr, rt->fib6_src.plen,
1449 offsetof(struct fib6_info, fib6_src),
1450 allow_create, replace_required, extack);
1451
1452 if (IS_ERR(sn)) {
1453 err = PTR_ERR(sn);
1454 goto failure;
1455 }
1456 }
1457
1458 if (!rcu_access_pointer(fn->leaf)) {
1459 if (fn->fn_flags & RTN_TL_ROOT) {
1460 /* put back null_entry for root node */
1461 rcu_assign_pointer(fn->leaf,
1462 info->nl_net->ipv6.fib6_null_entry);
1463 } else {
1464 fib6_info_hold(rt);
1465 rcu_assign_pointer(fn->leaf, rt);
1466 }
1467 }
1468 fn = sn;
1469 }
1470 #endif
1471
1472 err = fib6_add_rt2node(fn, rt, info, extack);
1473 if (!err) {
1474 if (rt->nh)
1475 list_add(&rt->nh_list, &rt->nh->f6i_list);
1476 __fib6_update_sernum_upto_root(rt, sernum);
1477 fib6_start_gc(info->nl_net, rt);
1478 }
1479
1480 out:
1481 if (err) {
1482 #ifdef CONFIG_IPV6_SUBTREES
1483 /*
1484 * If fib6_add_1 has cleared the old leaf pointer in the
1485 * super-tree leaf node we have to find a new one for it.
1486 */
1487 if (pn != fn) {
1488 struct fib6_info *pn_leaf =
1489 rcu_dereference_protected(pn->leaf,
1490 lockdep_is_held(&table->tb6_lock));
1491 if (pn_leaf == rt) {
1492 pn_leaf = NULL;
1493 RCU_INIT_POINTER(pn->leaf, NULL);
1494 fib6_info_release(rt);
1495 }
1496 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) {
1497 pn_leaf = fib6_find_prefix(info->nl_net, table,
1498 pn);
1499 #if RT6_DEBUG >= 2
1500 if (!pn_leaf) {
1501 WARN_ON(!pn_leaf);
1502 pn_leaf =
1503 info->nl_net->ipv6.fib6_null_entry;
1504 }
1505 #endif
1506 fib6_info_hold(pn_leaf);
1507 rcu_assign_pointer(pn->leaf, pn_leaf);
1508 }
1509 }
1510 #endif
1511 goto failure;
1512 } else if (fib6_requires_src(rt)) {
1513 fib6_routes_require_src_inc(info->nl_net);
1514 }
1515 return err;
1516
1517 failure:
1518 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if:
1519 * 1. fn is an intermediate node and we failed to add the new
1520 * route to it in both subtree creation failure and fib6_add_rt2node()
1521 * failure case.
1522 * 2. fn is the root node in the table and we fail to add the first
1523 * default route to it.
1524 */
1525 if (fn &&
1526 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) ||
1527 (fn->fn_flags & RTN_TL_ROOT &&
1528 !rcu_access_pointer(fn->leaf))))
1529 fib6_repair_tree(info->nl_net, table, fn);
1530 return err;
1531 }
1532
1533 /*
1534 * Routing tree lookup
1535 *
1536 */
1537
1538 struct lookup_args {
1539 int offset; /* key offset on fib6_info */
1540 const struct in6_addr *addr; /* search key */
1541 };
1542
1543 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root,
1544 struct lookup_args *args)
1545 {
1546 struct fib6_node *fn;
1547 __be32 dir;
1548
1549 if (unlikely(args->offset == 0))
1550 return NULL;
1551
1552 /*
1553 * Descend on a tree
1554 */
1555
1556 fn = root;
1557
1558 for (;;) {
1559 struct fib6_node *next;
1560
1561 dir = addr_bit_set(args->addr, fn->fn_bit);
1562
1563 next = dir ? rcu_dereference(fn->right) :
1564 rcu_dereference(fn->left);
1565
1566 if (next) {
1567 fn = next;
1568 continue;
1569 }
1570 break;
1571 }
1572
1573 while (fn) {
1574 struct fib6_node *subtree = FIB6_SUBTREE(fn);
1575
1576 if (subtree || fn->fn_flags & RTN_RTINFO) {
1577 struct fib6_info *leaf = rcu_dereference(fn->leaf);
1578 struct rt6key *key;
1579
1580 if (!leaf)
1581 goto backtrack;
1582
1583 key = (struct rt6key *) ((u8 *)leaf + args->offset);
1584
1585 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
1586 #ifdef CONFIG_IPV6_SUBTREES
1587 if (subtree) {
1588 struct fib6_node *sfn;
1589 sfn = fib6_node_lookup_1(subtree,
1590 args + 1);
1591 if (!sfn)
1592 goto backtrack;
1593 fn = sfn;
1594 }
1595 #endif
1596 if (fn->fn_flags & RTN_RTINFO)
1597 return fn;
1598 }
1599 }
1600 backtrack:
1601 if (fn->fn_flags & RTN_ROOT)
1602 break;
1603
1604 fn = rcu_dereference(fn->parent);
1605 }
1606
1607 return NULL;
1608 }
1609
1610 /* called with rcu_read_lock() held
1611 */
1612 struct fib6_node *fib6_node_lookup(struct fib6_node *root,
1613 const struct in6_addr *daddr,
1614 const struct in6_addr *saddr)
1615 {
1616 struct fib6_node *fn;
1617 struct lookup_args args[] = {
1618 {
1619 .offset = offsetof(struct fib6_info, fib6_dst),
1620 .addr = daddr,
1621 },
1622 #ifdef CONFIG_IPV6_SUBTREES
1623 {
1624 .offset = offsetof(struct fib6_info, fib6_src),
1625 .addr = saddr,
1626 },
1627 #endif
1628 {
1629 .offset = 0, /* sentinel */
1630 }
1631 };
1632
1633 fn = fib6_node_lookup_1(root, daddr ? args : args + 1);
1634 if (!fn || fn->fn_flags & RTN_TL_ROOT)
1635 fn = root;
1636
1637 return fn;
1638 }
1639
1640 /*
1641 * Get node with specified destination prefix (and source prefix,
1642 * if subtrees are used)
1643 * exact_match == true means we try to find fn with exact match of
1644 * the passed in prefix addr
1645 * exact_match == false means we try to find fn with longest prefix
1646 * match of the passed in prefix addr. This is useful for finding fn
1647 * for cached route as it will be stored in the exception table under
1648 * the node with longest prefix length.
1649 */
1650
1651
1652 static struct fib6_node *fib6_locate_1(struct fib6_node *root,
1653 const struct in6_addr *addr,
1654 int plen, int offset,
1655 bool exact_match)
1656 {
1657 struct fib6_node *fn, *prev = NULL;
1658
1659 for (fn = root; fn ; ) {
1660 struct fib6_info *leaf = rcu_dereference(fn->leaf);
1661 struct rt6key *key;
1662
1663 /* This node is being deleted */
1664 if (!leaf) {
1665 if (plen <= fn->fn_bit)
1666 goto out;
1667 else
1668 goto next;
1669 }
1670
1671 key = (struct rt6key *)((u8 *)leaf + offset);
1672
1673 /*
1674 * Prefix match
1675 */
1676 if (plen < fn->fn_bit ||
1677 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
1678 goto out;
1679
1680 if (plen == fn->fn_bit)
1681 return fn;
1682
1683 if (fn->fn_flags & RTN_RTINFO)
1684 prev = fn;
1685
1686 next:
1687 /*
1688 * We have more bits to go
1689 */
1690 if (addr_bit_set(addr, fn->fn_bit))
1691 fn = rcu_dereference(fn->right);
1692 else
1693 fn = rcu_dereference(fn->left);
1694 }
1695 out:
1696 if (exact_match)
1697 return NULL;
1698 else
1699 return prev;
1700 }
1701
1702 struct fib6_node *fib6_locate(struct fib6_node *root,
1703 const struct in6_addr *daddr, int dst_len,
1704 const struct in6_addr *saddr, int src_len,
1705 bool exact_match)
1706 {
1707 struct fib6_node *fn;
1708
1709 fn = fib6_locate_1(root, daddr, dst_len,
1710 offsetof(struct fib6_info, fib6_dst),
1711 exact_match);
1712
1713 #ifdef CONFIG_IPV6_SUBTREES
1714 if (src_len) {
1715 WARN_ON(saddr == NULL);
1716 if (fn) {
1717 struct fib6_node *subtree = FIB6_SUBTREE(fn);
1718
1719 if (subtree) {
1720 fn = fib6_locate_1(subtree, saddr, src_len,
1721 offsetof(struct fib6_info, fib6_src),
1722 exact_match);
1723 }
1724 }
1725 }
1726 #endif
1727
1728 if (fn && fn->fn_flags & RTN_RTINFO)
1729 return fn;
1730
1731 return NULL;
1732 }
1733
1734
1735 /*
1736 * Deletion
1737 *
1738 */
1739
1740 static struct fib6_info *fib6_find_prefix(struct net *net,
1741 struct fib6_table *table,
1742 struct fib6_node *fn)
1743 {
1744 struct fib6_node *child_left, *child_right;
1745
1746 if (fn->fn_flags & RTN_ROOT)
1747 return net->ipv6.fib6_null_entry;
1748
1749 while (fn) {
1750 child_left = rcu_dereference_protected(fn->left,
1751 lockdep_is_held(&table->tb6_lock));
1752 child_right = rcu_dereference_protected(fn->right,
1753 lockdep_is_held(&table->tb6_lock));
1754 if (child_left)
1755 return rcu_dereference_protected(child_left->leaf,
1756 lockdep_is_held(&table->tb6_lock));
1757 if (child_right)
1758 return rcu_dereference_protected(child_right->leaf,
1759 lockdep_is_held(&table->tb6_lock));
1760
1761 fn = FIB6_SUBTREE(fn);
1762 }
1763 return NULL;
1764 }
1765
1766 /*
1767 * Called to trim the tree of intermediate nodes when possible. "fn"
1768 * is the node we want to try and remove.
1769 * Need to own table->tb6_lock
1770 */
1771
1772 static struct fib6_node *fib6_repair_tree(struct net *net,
1773 struct fib6_table *table,
1774 struct fib6_node *fn)
1775 {
1776 int children;
1777 int nstate;
1778 struct fib6_node *child;
1779 struct fib6_walker *w;
1780 int iter = 0;
1781
1782 /* Set fn->leaf to null_entry for root node. */
1783 if (fn->fn_flags & RTN_TL_ROOT) {
1784 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry);
1785 return fn;
1786 }
1787
1788 for (;;) {
1789 struct fib6_node *fn_r = rcu_dereference_protected(fn->right,
1790 lockdep_is_held(&table->tb6_lock));
1791 struct fib6_node *fn_l = rcu_dereference_protected(fn->left,
1792 lockdep_is_held(&table->tb6_lock));
1793 struct fib6_node *pn = rcu_dereference_protected(fn->parent,
1794 lockdep_is_held(&table->tb6_lock));
1795 struct fib6_node *pn_r = rcu_dereference_protected(pn->right,
1796 lockdep_is_held(&table->tb6_lock));
1797 struct fib6_node *pn_l = rcu_dereference_protected(pn->left,
1798 lockdep_is_held(&table->tb6_lock));
1799 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf,
1800 lockdep_is_held(&table->tb6_lock));
1801 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf,
1802 lockdep_is_held(&table->tb6_lock));
1803 struct fib6_info *new_fn_leaf;
1804
1805 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1806 iter++;
1807
1808 WARN_ON(fn->fn_flags & RTN_RTINFO);
1809 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1810 WARN_ON(fn_leaf);
1811
1812 children = 0;
1813 child = NULL;
1814 if (fn_r)
1815 child = fn_r, children |= 1;
1816 if (fn_l)
1817 child = fn_l, children |= 2;
1818
1819 if (children == 3 || FIB6_SUBTREE(fn)
1820 #ifdef CONFIG_IPV6_SUBTREES
1821 /* Subtree root (i.e. fn) may have one child */
1822 || (children && fn->fn_flags & RTN_ROOT)
1823 #endif
1824 ) {
1825 new_fn_leaf = fib6_find_prefix(net, table, fn);
1826 #if RT6_DEBUG >= 2
1827 if (!new_fn_leaf) {
1828 WARN_ON(!new_fn_leaf);
1829 new_fn_leaf = net->ipv6.fib6_null_entry;
1830 }
1831 #endif
1832 fib6_info_hold(new_fn_leaf);
1833 rcu_assign_pointer(fn->leaf, new_fn_leaf);
1834 return pn;
1835 }
1836
1837 #ifdef CONFIG_IPV6_SUBTREES
1838 if (FIB6_SUBTREE(pn) == fn) {
1839 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1840 RCU_INIT_POINTER(pn->subtree, NULL);
1841 nstate = FWS_L;
1842 } else {
1843 WARN_ON(fn->fn_flags & RTN_ROOT);
1844 #endif
1845 if (pn_r == fn)
1846 rcu_assign_pointer(pn->right, child);
1847 else if (pn_l == fn)
1848 rcu_assign_pointer(pn->left, child);
1849 #if RT6_DEBUG >= 2
1850 else
1851 WARN_ON(1);
1852 #endif
1853 if (child)
1854 rcu_assign_pointer(child->parent, pn);
1855 nstate = FWS_R;
1856 #ifdef CONFIG_IPV6_SUBTREES
1857 }
1858 #endif
1859
1860 read_lock(&net->ipv6.fib6_walker_lock);
1861 FOR_WALKERS(net, w) {
1862 if (!child) {
1863 if (w->node == fn) {
1864 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1865 w->node = pn;
1866 w->state = nstate;
1867 }
1868 } else {
1869 if (w->node == fn) {
1870 w->node = child;
1871 if (children&2) {
1872 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1873 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT;
1874 } else {
1875 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1876 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT;
1877 }
1878 }
1879 }
1880 }
1881 read_unlock(&net->ipv6.fib6_walker_lock);
1882
1883 node_free(net, fn);
1884 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
1885 return pn;
1886
1887 RCU_INIT_POINTER(pn->leaf, NULL);
1888 fib6_info_release(pn_leaf);
1889 fn = pn;
1890 }
1891 }
1892
1893 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
1894 struct fib6_info __rcu **rtp, struct nl_info *info)
1895 {
1896 struct fib6_info *leaf, *replace_rt = NULL;
1897 struct fib6_walker *w;
1898 struct fib6_info *rt = rcu_dereference_protected(*rtp,
1899 lockdep_is_held(&table->tb6_lock));
1900 struct net *net = info->nl_net;
1901 bool notify_del = false;
1902
1903 RT6_TRACE("fib6_del_route\n");
1904
1905 /* If the deleted route is the first in the node and it is not part of
1906 * a multipath route, then we need to replace it with the next route
1907 * in the node, if exists.
1908 */
1909 leaf = rcu_dereference_protected(fn->leaf,
1910 lockdep_is_held(&table->tb6_lock));
1911 if (leaf == rt && !rt->fib6_nsiblings) {
1912 if (rcu_access_pointer(rt->fib6_next))
1913 replace_rt = rcu_dereference_protected(rt->fib6_next,
1914 lockdep_is_held(&table->tb6_lock));
1915 else
1916 notify_del = true;
1917 }
1918
1919 /* Unlink it */
1920 *rtp = rt->fib6_next;
1921 rt->fib6_node = NULL;
1922 net->ipv6.rt6_stats->fib_rt_entries--;
1923 net->ipv6.rt6_stats->fib_discarded_routes++;
1924
1925 /* Flush all cached dst in exception table */
1926 rt6_flush_exceptions(rt);
1927
1928 /* Reset round-robin state, if necessary */
1929 if (rcu_access_pointer(fn->rr_ptr) == rt)
1930 fn->rr_ptr = NULL;
1931
1932 /* Remove this entry from other siblings */
1933 if (rt->fib6_nsiblings) {
1934 struct fib6_info *sibling, *next_sibling;
1935
1936 /* The route is deleted from a multipath route. If this
1937 * multipath route is the first route in the node, then we need
1938 * to emit a delete notification. Otherwise, we need to skip
1939 * the notification.
1940 */
1941 if (rt->fib6_metric == leaf->fib6_metric &&
1942 rt6_qualify_for_ecmp(leaf))
1943 notify_del = true;
1944 list_for_each_entry_safe(sibling, next_sibling,
1945 &rt->fib6_siblings, fib6_siblings)
1946 sibling->fib6_nsiblings--;
1947 rt->fib6_nsiblings = 0;
1948 list_del_init(&rt->fib6_siblings);
1949 rt6_multipath_rebalance(next_sibling);
1950 }
1951
1952 /* Adjust walkers */
1953 read_lock(&net->ipv6.fib6_walker_lock);
1954 FOR_WALKERS(net, w) {
1955 if (w->state == FWS_C && w->leaf == rt) {
1956 RT6_TRACE("walker %p adjusted by delroute\n", w);
1957 w->leaf = rcu_dereference_protected(rt->fib6_next,
1958 lockdep_is_held(&table->tb6_lock));
1959 if (!w->leaf)
1960 w->state = FWS_U;
1961 }
1962 }
1963 read_unlock(&net->ipv6.fib6_walker_lock);
1964
1965 /* If it was last route, call fib6_repair_tree() to:
1966 * 1. For root node, put back null_entry as how the table was created.
1967 * 2. For other nodes, expunge its radix tree node.
1968 */
1969 if (!rcu_access_pointer(fn->leaf)) {
1970 if (!(fn->fn_flags & RTN_TL_ROOT)) {
1971 fn->fn_flags &= ~RTN_RTINFO;
1972 net->ipv6.rt6_stats->fib_route_nodes--;
1973 }
1974 fn = fib6_repair_tree(net, table, fn);
1975 }
1976
1977 fib6_purge_rt(rt, fn, net);
1978
1979 if (!info->skip_notify_kernel) {
1980 if (notify_del)
1981 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL,
1982 rt, NULL);
1983 else if (replace_rt)
1984 call_fib6_entry_notifiers_replace(net, replace_rt);
1985 }
1986 if (!info->skip_notify)
1987 inet6_rt_notify(RTM_DELROUTE, rt, info, 0);
1988
1989 fib6_info_release(rt);
1990 }
1991
1992 /* Need to own table->tb6_lock */
1993 int fib6_del(struct fib6_info *rt, struct nl_info *info)
1994 {
1995 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node,
1996 lockdep_is_held(&rt->fib6_table->tb6_lock));
1997 struct fib6_table *table = rt->fib6_table;
1998 struct net *net = info->nl_net;
1999 struct fib6_info __rcu **rtp;
2000 struct fib6_info __rcu **rtp_next;
2001
2002 if (!fn || rt == net->ipv6.fib6_null_entry)
2003 return -ENOENT;
2004
2005 WARN_ON(!(fn->fn_flags & RTN_RTINFO));
2006
2007 /*
2008 * Walk the leaf entries looking for ourself
2009 */
2010
2011 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) {
2012 struct fib6_info *cur = rcu_dereference_protected(*rtp,
2013 lockdep_is_held(&table->tb6_lock));
2014 if (rt == cur) {
2015 if (fib6_requires_src(cur))
2016 fib6_routes_require_src_dec(info->nl_net);
2017 fib6_del_route(table, fn, rtp, info);
2018 return 0;
2019 }
2020 rtp_next = &cur->fib6_next;
2021 }
2022 return -ENOENT;
2023 }
2024
2025 /*
2026 * Tree traversal function.
2027 *
2028 * Certainly, it is not interrupt safe.
2029 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
2030 * It means, that we can modify tree during walking
2031 * and use this function for garbage collection, clone pruning,
2032 * cleaning tree when a device goes down etc. etc.
2033 *
2034 * It guarantees that every node will be traversed,
2035 * and that it will be traversed only once.
2036 *
2037 * Callback function w->func may return:
2038 * 0 -> continue walking.
2039 * positive value -> walking is suspended (used by tree dumps,
2040 * and probably by gc, if it will be split to several slices)
2041 * negative value -> terminate walking.
2042 *
2043 * The function itself returns:
2044 * 0 -> walk is complete.
2045 * >0 -> walk is incomplete (i.e. suspended)
2046 * <0 -> walk is terminated by an error.
2047 *
2048 * This function is called with tb6_lock held.
2049 */
2050
2051 static int fib6_walk_continue(struct fib6_walker *w)
2052 {
2053 struct fib6_node *fn, *pn, *left, *right;
2054
2055 /* w->root should always be table->tb6_root */
2056 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT));
2057
2058 for (;;) {
2059 fn = w->node;
2060 if (!fn)
2061 return 0;
2062
2063 switch (w->state) {
2064 #ifdef CONFIG_IPV6_SUBTREES
2065 case FWS_S:
2066 if (FIB6_SUBTREE(fn)) {
2067 w->node = FIB6_SUBTREE(fn);
2068 continue;
2069 }
2070 w->state = FWS_L;
2071 fallthrough;
2072 #endif
2073 case FWS_L:
2074 left = rcu_dereference_protected(fn->left, 1);
2075 if (left) {
2076 w->node = left;
2077 w->state = FWS_INIT;
2078 continue;
2079 }
2080 w->state = FWS_R;
2081 fallthrough;
2082 case FWS_R:
2083 right = rcu_dereference_protected(fn->right, 1);
2084 if (right) {
2085 w->node = right;
2086 w->state = FWS_INIT;
2087 continue;
2088 }
2089 w->state = FWS_C;
2090 w->leaf = rcu_dereference_protected(fn->leaf, 1);
2091 fallthrough;
2092 case FWS_C:
2093 if (w->leaf && fn->fn_flags & RTN_RTINFO) {
2094 int err;
2095
2096 if (w->skip) {
2097 w->skip--;
2098 goto skip;
2099 }
2100
2101 err = w->func(w);
2102 if (err)
2103 return err;
2104
2105 w->count++;
2106 continue;
2107 }
2108 skip:
2109 w->state = FWS_U;
2110 fallthrough;
2111 case FWS_U:
2112 if (fn == w->root)
2113 return 0;
2114 pn = rcu_dereference_protected(fn->parent, 1);
2115 left = rcu_dereference_protected(pn->left, 1);
2116 right = rcu_dereference_protected(pn->right, 1);
2117 w->node = pn;
2118 #ifdef CONFIG_IPV6_SUBTREES
2119 if (FIB6_SUBTREE(pn) == fn) {
2120 WARN_ON(!(fn->fn_flags & RTN_ROOT));
2121 w->state = FWS_L;
2122 continue;
2123 }
2124 #endif
2125 if (left == fn) {
2126 w->state = FWS_R;
2127 continue;
2128 }
2129 if (right == fn) {
2130 w->state = FWS_C;
2131 w->leaf = rcu_dereference_protected(w->node->leaf, 1);
2132 continue;
2133 }
2134 #if RT6_DEBUG >= 2
2135 WARN_ON(1);
2136 #endif
2137 }
2138 }
2139 }
2140
2141 static int fib6_walk(struct net *net, struct fib6_walker *w)
2142 {
2143 int res;
2144
2145 w->state = FWS_INIT;
2146 w->node = w->root;
2147
2148 fib6_walker_link(net, w);
2149 res = fib6_walk_continue(w);
2150 if (res <= 0)
2151 fib6_walker_unlink(net, w);
2152 return res;
2153 }
2154
2155 static int fib6_clean_node(struct fib6_walker *w)
2156 {
2157 int res;
2158 struct fib6_info *rt;
2159 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w);
2160 struct nl_info info = {
2161 .nl_net = c->net,
2162 .skip_notify = c->skip_notify,
2163 };
2164
2165 if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
2166 w->node->fn_sernum != c->sernum)
2167 w->node->fn_sernum = c->sernum;
2168
2169 if (!c->func) {
2170 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE);
2171 w->leaf = NULL;
2172 return 0;
2173 }
2174
2175 for_each_fib6_walker_rt(w) {
2176 res = c->func(rt, c->arg);
2177 if (res == -1) {
2178 w->leaf = rt;
2179 res = fib6_del(rt, &info);
2180 if (res) {
2181 #if RT6_DEBUG >= 2
2182 pr_debug("%s: del failed: rt=%p@%p err=%d\n",
2183 __func__, rt,
2184 rcu_access_pointer(rt->fib6_node),
2185 res);
2186 #endif
2187 continue;
2188 }
2189 return 0;
2190 } else if (res == -2) {
2191 if (WARN_ON(!rt->fib6_nsiblings))
2192 continue;
2193 rt = list_last_entry(&rt->fib6_siblings,
2194 struct fib6_info, fib6_siblings);
2195 continue;
2196 }
2197 WARN_ON(res != 0);
2198 }
2199 w->leaf = rt;
2200 return 0;
2201 }
2202
2203 /*
2204 * Convenient frontend to tree walker.
2205 *
2206 * func is called on each route.
2207 * It may return -2 -> skip multipath route.
2208 * -1 -> delete this route.
2209 * 0 -> continue walking
2210 */
2211
2212 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
2213 int (*func)(struct fib6_info *, void *arg),
2214 int sernum, void *arg, bool skip_notify)
2215 {
2216 struct fib6_cleaner c;
2217
2218 c.w.root = root;
2219 c.w.func = fib6_clean_node;
2220 c.w.count = 0;
2221 c.w.skip = 0;
2222 c.w.skip_in_node = 0;
2223 c.func = func;
2224 c.sernum = sernum;
2225 c.arg = arg;
2226 c.net = net;
2227 c.skip_notify = skip_notify;
2228
2229 fib6_walk(net, &c.w);
2230 }
2231
2232 static void __fib6_clean_all(struct net *net,
2233 int (*func)(struct fib6_info *, void *),
2234 int sernum, void *arg, bool skip_notify)
2235 {
2236 struct fib6_table *table;
2237 struct hlist_head *head;
2238 unsigned int h;
2239
2240 rcu_read_lock();
2241 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
2242 head = &net->ipv6.fib_table_hash[h];
2243 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
2244 spin_lock_bh(&table->tb6_lock);
2245 fib6_clean_tree(net, &table->tb6_root,
2246 func, sernum, arg, skip_notify);
2247 spin_unlock_bh(&table->tb6_lock);
2248 }
2249 }
2250 rcu_read_unlock();
2251 }
2252
2253 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *),
2254 void *arg)
2255 {
2256 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, false);
2257 }
2258
2259 void fib6_clean_all_skip_notify(struct net *net,
2260 int (*func)(struct fib6_info *, void *),
2261 void *arg)
2262 {
2263 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, true);
2264 }
2265
2266 static void fib6_flush_trees(struct net *net)
2267 {
2268 int new_sernum = fib6_new_sernum(net);
2269
2270 __fib6_clean_all(net, NULL, new_sernum, NULL, false);
2271 }
2272
2273 /*
2274 * Garbage collection
2275 */
2276
2277 static int fib6_age(struct fib6_info *rt, void *arg)
2278 {
2279 struct fib6_gc_args *gc_args = arg;
2280 unsigned long now = jiffies;
2281
2282 /*
2283 * check addrconf expiration here.
2284 * Routes are expired even if they are in use.
2285 */
2286
2287 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) {
2288 if (time_after(now, rt->expires)) {
2289 RT6_TRACE("expiring %p\n", rt);
2290 return -1;
2291 }
2292 gc_args->more++;
2293 }
2294
2295 /* Also age clones in the exception table.
2296 * Note, that clones are aged out
2297 * only if they are not in use now.
2298 */
2299 rt6_age_exceptions(rt, gc_args, now);
2300
2301 return 0;
2302 }
2303
2304 void fib6_run_gc(unsigned long expires, struct net *net, bool force)
2305 {
2306 struct fib6_gc_args gc_args;
2307 unsigned long now;
2308
2309 if (force) {
2310 spin_lock_bh(&net->ipv6.fib6_gc_lock);
2311 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) {
2312 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
2313 return;
2314 }
2315 gc_args.timeout = expires ? (int)expires :
2316 net->ipv6.sysctl.ip6_rt_gc_interval;
2317 gc_args.more = 0;
2318
2319 fib6_clean_all(net, fib6_age, &gc_args);
2320 now = jiffies;
2321 net->ipv6.ip6_rt_last_gc = now;
2322
2323 if (gc_args.more)
2324 mod_timer(&net->ipv6.ip6_fib_timer,
2325 round_jiffies(now
2326 + net->ipv6.sysctl.ip6_rt_gc_interval));
2327 else
2328 del_timer(&net->ipv6.ip6_fib_timer);
2329 spin_unlock_bh(&net->ipv6.fib6_gc_lock);
2330 }
2331
2332 static void fib6_gc_timer_cb(struct timer_list *t)
2333 {
2334 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer);
2335
2336 fib6_run_gc(0, arg, true);
2337 }
2338
2339 static int __net_init fib6_net_init(struct net *net)
2340 {
2341 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
2342 int err;
2343
2344 err = fib6_notifier_init(net);
2345 if (err)
2346 return err;
2347
2348 spin_lock_init(&net->ipv6.fib6_gc_lock);
2349 rwlock_init(&net->ipv6.fib6_walker_lock);
2350 INIT_LIST_HEAD(&net->ipv6.fib6_walkers);
2351 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0);
2352
2353 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
2354 if (!net->ipv6.rt6_stats)
2355 goto out_timer;
2356
2357 /* Avoid false sharing : Use at least a full cache line */
2358 size = max_t(size_t, size, L1_CACHE_BYTES);
2359
2360 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
2361 if (!net->ipv6.fib_table_hash)
2362 goto out_rt6_stats;
2363
2364 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
2365 GFP_KERNEL);
2366 if (!net->ipv6.fib6_main_tbl)
2367 goto out_fib_table_hash;
2368
2369 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
2370 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf,
2371 net->ipv6.fib6_null_entry);
2372 net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
2373 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
2374 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
2375
2376 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2377 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
2378 GFP_KERNEL);
2379 if (!net->ipv6.fib6_local_tbl)
2380 goto out_fib6_main_tbl;
2381 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
2382 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf,
2383 net->ipv6.fib6_null_entry);
2384 net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
2385 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
2386 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
2387 #endif
2388 fib6_tables_init(net);
2389
2390 return 0;
2391
2392 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2393 out_fib6_main_tbl:
2394 kfree(net->ipv6.fib6_main_tbl);
2395 #endif
2396 out_fib_table_hash:
2397 kfree(net->ipv6.fib_table_hash);
2398 out_rt6_stats:
2399 kfree(net->ipv6.rt6_stats);
2400 out_timer:
2401 fib6_notifier_exit(net);
2402 return -ENOMEM;
2403 }
2404
2405 static void fib6_net_exit(struct net *net)
2406 {
2407 unsigned int i;
2408
2409 del_timer_sync(&net->ipv6.ip6_fib_timer);
2410
2411 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) {
2412 struct hlist_head *head = &net->ipv6.fib_table_hash[i];
2413 struct hlist_node *tmp;
2414 struct fib6_table *tb;
2415
2416 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) {
2417 hlist_del(&tb->tb6_hlist);
2418 fib6_free_table(tb);
2419 }
2420 }
2421
2422 kfree(net->ipv6.fib_table_hash);
2423 kfree(net->ipv6.rt6_stats);
2424 fib6_notifier_exit(net);
2425 }
2426
2427 static struct pernet_operations fib6_net_ops = {
2428 .init = fib6_net_init,
2429 .exit = fib6_net_exit,
2430 };
2431
2432 int __init fib6_init(void)
2433 {
2434 int ret = -ENOMEM;
2435
2436 fib6_node_kmem = kmem_cache_create("fib6_nodes",
2437 sizeof(struct fib6_node),
2438 0, SLAB_HWCACHE_ALIGN,
2439 NULL);
2440 if (!fib6_node_kmem)
2441 goto out;
2442
2443 ret = register_pernet_subsys(&fib6_net_ops);
2444 if (ret)
2445 goto out_kmem_cache_create;
2446
2447 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL,
2448 inet6_dump_fib, 0);
2449 if (ret)
2450 goto out_unregister_subsys;
2451
2452 __fib6_flush_trees = fib6_flush_trees;
2453 out:
2454 return ret;
2455
2456 out_unregister_subsys:
2457 unregister_pernet_subsys(&fib6_net_ops);
2458 out_kmem_cache_create:
2459 kmem_cache_destroy(fib6_node_kmem);
2460 goto out;
2461 }
2462
2463 void fib6_gc_cleanup(void)
2464 {
2465 unregister_pernet_subsys(&fib6_net_ops);
2466 kmem_cache_destroy(fib6_node_kmem);
2467 }
2468
2469 #ifdef CONFIG_PROC_FS
2470 static int ipv6_route_seq_show(struct seq_file *seq, void *v)
2471 {
2472 struct fib6_info *rt = v;
2473 struct ipv6_route_iter *iter = seq->private;
2474 struct fib6_nh *fib6_nh = rt->fib6_nh;
2475 unsigned int flags = rt->fib6_flags;
2476 const struct net_device *dev;
2477
2478 if (rt->nh)
2479 fib6_nh = nexthop_fib6_nh(rt->nh);
2480
2481 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen);
2482
2483 #ifdef CONFIG_IPV6_SUBTREES
2484 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen);
2485 #else
2486 seq_puts(seq, "00000000000000000000000000000000 00 ");
2487 #endif
2488 if (fib6_nh->fib_nh_gw_family) {
2489 flags |= RTF_GATEWAY;
2490 seq_printf(seq, "%pi6", &fib6_nh->fib_nh_gw6);
2491 } else {
2492 seq_puts(seq, "00000000000000000000000000000000");
2493 }
2494
2495 dev = fib6_nh->fib_nh_dev;
2496 seq_printf(seq, " %08x %08x %08x %08x %8s\n",
2497 rt->fib6_metric, refcount_read(&rt->fib6_ref), 0,
2498 flags, dev ? dev->name : "");
2499 iter->w.leaf = NULL;
2500 return 0;
2501 }
2502
2503 static int ipv6_route_yield(struct fib6_walker *w)
2504 {
2505 struct ipv6_route_iter *iter = w->args;
2506
2507 if (!iter->skip)
2508 return 1;
2509
2510 do {
2511 iter->w.leaf = rcu_dereference_protected(
2512 iter->w.leaf->fib6_next,
2513 lockdep_is_held(&iter->tbl->tb6_lock));
2514 iter->skip--;
2515 if (!iter->skip && iter->w.leaf)
2516 return 1;
2517 } while (iter->w.leaf);
2518
2519 return 0;
2520 }
2521
2522 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter,
2523 struct net *net)
2524 {
2525 memset(&iter->w, 0, sizeof(iter->w));
2526 iter->w.func = ipv6_route_yield;
2527 iter->w.root = &iter->tbl->tb6_root;
2528 iter->w.state = FWS_INIT;
2529 iter->w.node = iter->w.root;
2530 iter->w.args = iter;
2531 iter->sernum = iter->w.root->fn_sernum;
2532 INIT_LIST_HEAD(&iter->w.lh);
2533 fib6_walker_link(net, &iter->w);
2534 }
2535
2536 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
2537 struct net *net)
2538 {
2539 unsigned int h;
2540 struct hlist_node *node;
2541
2542 if (tbl) {
2543 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1;
2544 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist));
2545 } else {
2546 h = 0;
2547 node = NULL;
2548 }
2549
2550 while (!node && h < FIB6_TABLE_HASHSZ) {
2551 node = rcu_dereference_bh(
2552 hlist_first_rcu(&net->ipv6.fib_table_hash[h++]));
2553 }
2554 return hlist_entry_safe(node, struct fib6_table, tb6_hlist);
2555 }
2556
2557 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter)
2558 {
2559 if (iter->sernum != iter->w.root->fn_sernum) {
2560 iter->sernum = iter->w.root->fn_sernum;
2561 iter->w.state = FWS_INIT;
2562 iter->w.node = iter->w.root;
2563 WARN_ON(iter->w.skip);
2564 iter->w.skip = iter->w.count;
2565 }
2566 }
2567
2568 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2569 {
2570 int r;
2571 struct fib6_info *n;
2572 struct net *net = seq_file_net(seq);
2573 struct ipv6_route_iter *iter = seq->private;
2574
2575 ++(*pos);
2576 if (!v)
2577 goto iter_table;
2578
2579 n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next);
2580 if (n)
2581 return n;
2582
2583 iter_table:
2584 ipv6_route_check_sernum(iter);
2585 spin_lock_bh(&iter->tbl->tb6_lock);
2586 r = fib6_walk_continue(&iter->w);
2587 spin_unlock_bh(&iter->tbl->tb6_lock);
2588 if (r > 0) {
2589 return iter->w.leaf;
2590 } else if (r < 0) {
2591 fib6_walker_unlink(net, &iter->w);
2592 return NULL;
2593 }
2594 fib6_walker_unlink(net, &iter->w);
2595
2596 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
2597 if (!iter->tbl)
2598 return NULL;
2599
2600 ipv6_route_seq_setup_walk(iter, net);
2601 goto iter_table;
2602 }
2603
2604 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
2605 __acquires(RCU_BH)
2606 {
2607 struct net *net = seq_file_net(seq);
2608 struct ipv6_route_iter *iter = seq->private;
2609
2610 rcu_read_lock_bh();
2611 iter->tbl = ipv6_route_seq_next_table(NULL, net);
2612 iter->skip = *pos;
2613
2614 if (iter->tbl) {
2615 ipv6_route_seq_setup_walk(iter, net);
2616 return ipv6_route_seq_next(seq, NULL, pos);
2617 } else {
2618 return NULL;
2619 }
2620 }
2621
2622 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter)
2623 {
2624 struct fib6_walker *w = &iter->w;
2625 return w->node && !(w->state == FWS_U && w->node == w->root);
2626 }
2627
2628 static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
2629 __releases(RCU_BH)
2630 {
2631 struct net *net = seq_file_net(seq);
2632 struct ipv6_route_iter *iter = seq->private;
2633
2634 if (ipv6_route_iter_active(iter))
2635 fib6_walker_unlink(net, &iter->w);
2636
2637 rcu_read_unlock_bh();
2638 }
2639
2640 const struct seq_operations ipv6_route_seq_ops = {
2641 .start = ipv6_route_seq_start,
2642 .next = ipv6_route_seq_next,
2643 .stop = ipv6_route_seq_stop,
2644 .show = ipv6_route_seq_show
2645 };
2646 #endif /* CONFIG_PROC_FS */
Linux with added FPC-III support