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modpost: drop unused command line switches
[linux/fpc-iii.git] / net / ipv6 / ip6_fib.c
blobae3786132c236b2bcde4f8f3008fceb2d6bc1cdd
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/ip.h>
33 #include <net/ipv6.h>
34 #include <net/ndisc.h>
35 #include <net/addrconf.h>
36 #include <net/lwtunnel.h>
37 #include <net/fib_notifier.h>
38
39 #include <net/ip6_fib.h>
40 #include <net/ip6_route.h>
41
42 static struct kmem_cache *fib6_node_kmem __read_mostly;
43
44 struct fib6_cleaner {
45 struct fib6_walker w;
46 struct net *net;
47 int (*func)(struct fib6_info *, void *arg);
48 int sernum;
49 void *arg;
50 bool skip_notify;
51 };
52
53 #ifdef CONFIG_IPV6_SUBTREES
54 #define FWS_INIT FWS_S
55 #else
56 #define FWS_INIT FWS_L
57 #endif
58
59 static struct fib6_info *fib6_find_prefix(struct net *net,
60 struct fib6_table *table,
61 struct fib6_node *fn);
62 static struct fib6_node *fib6_repair_tree(struct net *net,
63 struct fib6_table *table,
64 struct fib6_node *fn);
65 static int fib6_walk(struct net *net, struct fib6_walker *w);
66 static int fib6_walk_continue(struct fib6_walker *w);
67
68 /*
69 * A routing update causes an increase of the serial number on the
70 * affected subtree. This allows for cached routes to be asynchronously
71 * tested when modifications are made to the destination cache as a
72 * result of redirects, path MTU changes, etc.
73 */
74
75 static void fib6_gc_timer_cb(struct timer_list *t);
76
77 #define FOR_WALKERS(net, w) \
78 list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh)
79
80 static void fib6_walker_link(struct net *net, struct fib6_walker *w)
81 {
82 write_lock_bh(&net->ipv6.fib6_walker_lock);
83 list_add(&w->lh, &net->ipv6.fib6_walkers);
84 write_unlock_bh(&net->ipv6.fib6_walker_lock);
85 }
86
87 static void fib6_walker_unlink(struct net *net, struct fib6_walker *w)
88 {
89 write_lock_bh(&net->ipv6.fib6_walker_lock);
90 list_del(&w->lh);
91 write_unlock_bh(&net->ipv6.fib6_walker_lock);
92 }
93
94 static int fib6_new_sernum(struct net *net)
95 {
96 int new, old;
97
98 do {
99 old = atomic_read(&net->ipv6.fib6_sernum);
100 new = old < INT_MAX ? old + 1 : 1;
101 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum,
102 old, new) != old);
103 return new;
104 }
105
106 enum {
107 FIB6_NO_SERNUM_CHANGE = 0,
108 };
109
110 void fib6_update_sernum(struct net *net, struct fib6_info *f6i)
111 {
112 struct fib6_node *fn;
113
114 fn = rcu_dereference_protected(f6i->fib6_node,
115 lockdep_is_held(&f6i->fib6_table->tb6_lock));
116 if (fn)
117 fn->fn_sernum = fib6_new_sernum(net);
118 }
119
120 /*
121 * Auxiliary address test functions for the radix tree.
122 *
123 * These assume a 32bit processor (although it will work on
124 * 64bit processors)
125 */
126
127 /*
128 * test bit
129 */
130 #if defined(__LITTLE_ENDIAN)
131 # define BITOP_BE32_SWIZZLE (0x1F & ~7)
132 #else
133 # define BITOP_BE32_SWIZZLE 0
134 #endif
135
136 static __be32 addr_bit_set(const void *token, int fn_bit)
137 {
138 const __be32 *addr = token;
139 /*
140 * Here,
141 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
142 * is optimized version of
143 * htonl(1 << ((~fn_bit)&0x1F))
144 * See include/asm-generic/bitops/le.h.
145 */
146 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
147 addr[fn_bit >> 5];
148 }
149
150 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags)
151 {
152 struct fib6_info *f6i;
153
154 f6i = kzalloc(sizeof(*f6i), gfp_flags);
155 if (!f6i)
156 return NULL;
157
158 f6i->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
159 if (!f6i->rt6i_pcpu) {
160 kfree(f6i);
161 return NULL;
162 }
163
164 INIT_LIST_HEAD(&f6i->fib6_siblings);
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
175 WARN_ON(f6i->fib6_node);
176
177 bucket = rcu_dereference_protected(f6i->rt6i_exception_bucket, 1);
178 if (bucket) {
179 f6i->rt6i_exception_bucket = NULL;
180 kfree(bucket);
181 }
182
183 if (f6i->rt6i_pcpu) {
184 int cpu;
185
186 for_each_possible_cpu(cpu) {
187 struct rt6_info **ppcpu_rt;
188 struct rt6_info *pcpu_rt;
189
190 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu);
191 pcpu_rt = *ppcpu_rt;
192 if (pcpu_rt) {
193 dst_dev_put(&pcpu_rt->dst);
194 dst_release(&pcpu_rt->dst);
195 *ppcpu_rt = NULL;
196 }
197 }
198
199 free_percpu(f6i->rt6i_pcpu);
200 }
201
202 lwtstate_put(f6i->fib6_nh.nh_lwtstate);
203
204 if (f6i->fib6_nh.nh_dev)
205 dev_put(f6i->fib6_nh.nh_dev);
206
207 ip_fib_metrics_put(f6i->fib6_metrics);
208
209 kfree(f6i);
210 }
211 EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu);
212
213 static struct fib6_node *node_alloc(struct net *net)
214 {
215 struct fib6_node *fn;
216
217 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
218 if (fn)
219 net->ipv6.rt6_stats->fib_nodes++;
220
221 return fn;
222 }
223
224 static void node_free_immediate(struct net *net, struct fib6_node *fn)
225 {
226 kmem_cache_free(fib6_node_kmem, fn);
227 net->ipv6.rt6_stats->fib_nodes--;
228 }
229
230 static void node_free_rcu(struct rcu_head *head)
231 {
232 struct fib6_node *fn = container_of(head, struct fib6_node, rcu);
233
234 kmem_cache_free(fib6_node_kmem, fn);
235 }
236
237 static void node_free(struct net *net, struct fib6_node *fn)
238 {
239 call_rcu(&fn->rcu, node_free_rcu);
240 net->ipv6.rt6_stats->fib_nodes--;
241 }
242
243 static void fib6_free_table(struct fib6_table *table)
244 {
245 inetpeer_invalidate_tree(&table->tb6_peers);
246 kfree(table);
247 }
248
249 static void fib6_link_table(struct net *net, struct fib6_table *tb)
250 {
251 unsigned int h;
252
253 /*
254 * Initialize table lock at a single place to give lockdep a key,
255 * tables aren't visible prior to being linked to the list.
256 */
257 spin_lock_init(&tb->tb6_lock);
258 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
259
260 /*
261 * No protection necessary, this is the only list mutatation
262 * operation, tables never disappear once they exist.
263 */
264 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
265 }
266
267 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
268
269 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
270 {
271 struct fib6_table *table;
272
273 table = kzalloc(sizeof(*table), GFP_ATOMIC);
274 if (table) {
275 table->tb6_id = id;
276 rcu_assign_pointer(table->tb6_root.leaf,
277 net->ipv6.fib6_null_entry);
278 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
279 inet_peer_base_init(&table->tb6_peers);
280 }
281
282 return table;
283 }
284
285 struct fib6_table *fib6_new_table(struct net *net, u32 id)
286 {
287 struct fib6_table *tb;
288
289 if (id == 0)
290 id = RT6_TABLE_MAIN;
291 tb = fib6_get_table(net, id);
292 if (tb)
293 return tb;
294
295 tb = fib6_alloc_table(net, id);
296 if (tb)
297 fib6_link_table(net, tb);
298
299 return tb;
300 }
301 EXPORT_SYMBOL_GPL(fib6_new_table);
302
303 struct fib6_table *fib6_get_table(struct net *net, u32 id)
304 {
305 struct fib6_table *tb;
306 struct hlist_head *head;
307 unsigned int h;
308
309 if (id == 0)
310 id = RT6_TABLE_MAIN;
311 h = id & (FIB6_TABLE_HASHSZ - 1);
312 rcu_read_lock();
313 head = &net->ipv6.fib_table_hash[h];
314 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
315 if (tb->tb6_id == id) {
316 rcu_read_unlock();
317 return tb;
318 }
319 }
320 rcu_read_unlock();
321
322 return NULL;
323 }
324 EXPORT_SYMBOL_GPL(fib6_get_table);
325
326 static void __net_init fib6_tables_init(struct net *net)
327 {
328 fib6_link_table(net, net->ipv6.fib6_main_tbl);
329 fib6_link_table(net, net->ipv6.fib6_local_tbl);
330 }
331 #else
332
333 struct fib6_table *fib6_new_table(struct net *net, u32 id)
334 {
335 return fib6_get_table(net, id);
336 }
337
338 struct fib6_table *fib6_get_table(struct net *net, u32 id)
339 {
340 return net->ipv6.fib6_main_tbl;
341 }
342
343 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
344 const struct sk_buff *skb,
345 int flags, pol_lookup_t lookup)
346 {
347 struct rt6_info *rt;
348
349 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
350 if (rt->dst.error == -EAGAIN) {
351 ip6_rt_put(rt);
352 rt = net->ipv6.ip6_null_entry;
353 dst_hold(&rt->dst);
354 }
355
356 return &rt->dst;
357 }
358
359 /* called with rcu lock held; no reference taken on fib6_info */
360 struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
361 int flags)
362 {
363 return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6, flags);
364 }
365
366 static void __net_init fib6_tables_init(struct net *net)
367 {
368 fib6_link_table(net, net->ipv6.fib6_main_tbl);
369 }
370
371 #endif
372
373 unsigned int fib6_tables_seq_read(struct net *net)
374 {
375 unsigned int h, fib_seq = 0;
376
377 rcu_read_lock();
378 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
379 struct hlist_head *head = &net->ipv6.fib_table_hash[h];
380 struct fib6_table *tb;
381
382 hlist_for_each_entry_rcu(tb, head, tb6_hlist)
383 fib_seq += tb->fib_seq;
384 }
385 rcu_read_unlock();
386
387 return fib_seq;
388 }
389
390 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net,
391 enum fib_event_type event_type,
392 struct fib6_info *rt)
393 {
394 struct fib6_entry_notifier_info info = {
395 .rt = rt,
396 };
397
398 return call_fib6_notifier(nb, net, event_type, &info.info);
399 }
400
401 static int call_fib6_entry_notifiers(struct net *net,
402 enum fib_event_type event_type,
403 struct fib6_info *rt,
404 struct netlink_ext_ack *extack)
405 {
406 struct fib6_entry_notifier_info info = {
407 .info.extack = extack,
408 .rt = rt,
409 };
410
411 rt->fib6_table->fib_seq++;
412 return call_fib6_notifiers(net, event_type, &info.info);
413 }
414
415 struct fib6_dump_arg {
416 struct net *net;
417 struct notifier_block *nb;
418 };
419
420 static void fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg)
421 {
422 if (rt == arg->net->ipv6.fib6_null_entry)
423 return;
424 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt);
425 }
426
427 static int fib6_node_dump(struct fib6_walker *w)
428 {
429 struct fib6_info *rt;
430
431 for_each_fib6_walker_rt(w)
432 fib6_rt_dump(rt, w->args);
433 w->leaf = NULL;
434 return 0;
435 }
436
437 static void fib6_table_dump(struct net *net, struct fib6_table *tb,
438 struct fib6_walker *w)
439 {
440 w->root = &tb->tb6_root;
441 spin_lock_bh(&tb->tb6_lock);
442 fib6_walk(net, w);
443 spin_unlock_bh(&tb->tb6_lock);
444 }
445
446 /* Called with rcu_read_lock() */
447 int fib6_tables_dump(struct net *net, struct notifier_block *nb)
448 {
449 struct fib6_dump_arg arg;
450 struct fib6_walker *w;
451 unsigned int h;
452
453 w = kzalloc(sizeof(*w), GFP_ATOMIC);
454 if (!w)
455 return -ENOMEM;
456
457 w->func = fib6_node_dump;
458 arg.net = net;
459 arg.nb = nb;
460 w->args = &arg;
461
462 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
463 struct hlist_head *head = &net->ipv6.fib_table_hash[h];
464 struct fib6_table *tb;
465
466 hlist_for_each_entry_rcu(tb, head, tb6_hlist)
467 fib6_table_dump(net, tb, w);
468 }
469
470 kfree(w);
471
472 return 0;
473 }
474
475 static int fib6_dump_node(struct fib6_walker *w)
476 {
477 int res;
478 struct fib6_info *rt;
479
480 for_each_fib6_walker_rt(w) {
481 res = rt6_dump_route(rt, w->args);
482 if (res < 0) {
483 /* Frame is full, suspend walking */
484 w->leaf = rt;
485 return 1;
486 }
487
488 /* Multipath routes are dumped in one route with the
489 * RTA_MULTIPATH attribute. Jump 'rt' to point to the
490 * last sibling of this route (no need to dump the
491 * sibling routes again)
492 */
493 if (rt->fib6_nsiblings)
494 rt = list_last_entry(&rt->fib6_siblings,
495 struct fib6_info,
496 fib6_siblings);
497 }
498 w->leaf = NULL;
499 return 0;
500 }
501
502 static void fib6_dump_end(struct netlink_callback *cb)
503 {
504 struct net *net = sock_net(cb->skb->sk);
505 struct fib6_walker *w = (void *)cb->args[2];
506
507 if (w) {
508 if (cb->args[4]) {
509 cb->args[4] = 0;
510 fib6_walker_unlink(net, w);
511 }
512 cb->args[2] = 0;
513 kfree(w);
514 }
515 cb->done = (void *)cb->args[3];
516 cb->args[1] = 3;
517 }
518
519 static int fib6_dump_done(struct netlink_callback *cb)
520 {
521 fib6_dump_end(cb);
522 return cb->done ? cb->done(cb) : 0;
523 }
524
525 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
526 struct netlink_callback *cb)
527 {
528 struct net *net = sock_net(skb->sk);
529 struct fib6_walker *w;
530 int res;
531
532 w = (void *)cb->args[2];
533 w->root = &table->tb6_root;
534
535 if (cb->args[4] == 0) {
536 w->count = 0;
537 w->skip = 0;
538
539 spin_lock_bh(&table->tb6_lock);
540 res = fib6_walk(net, w);
541 spin_unlock_bh(&table->tb6_lock);
542 if (res > 0) {
543 cb->args[4] = 1;
544 cb->args[5] = w->root->fn_sernum;
545 }
546 } else {
547 if (cb->args[5] != w->root->fn_sernum) {
548 /* Begin at the root if the tree changed */
549 cb->args[5] = w->root->fn_sernum;
550 w->state = FWS_INIT;
551 w->node = w->root;
552 w->skip = w->count;
553 } else
554 w->skip = 0;
555
556 spin_lock_bh(&table->tb6_lock);
557 res = fib6_walk_continue(w);
558 spin_unlock_bh(&table->tb6_lock);
559 if (res <= 0) {
560 fib6_walker_unlink(net, w);
561 cb->args[4] = 0;
562 }
563 }
564
565 return res;
566 }
567
568 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
569 {
570 const struct nlmsghdr *nlh = cb->nlh;
571 struct net *net = sock_net(skb->sk);
572 struct rt6_rtnl_dump_arg arg = {};
573 unsigned int h, s_h;
574 unsigned int e = 0, s_e;
575 struct fib6_walker *w;
576 struct fib6_table *tb;
577 struct hlist_head *head;
578 int res = 0;
579
580 if (cb->strict_check) {
581 int err;
582
583 err = ip_valid_fib_dump_req(net, nlh, &arg.filter, cb);
584 if (err < 0)
585 return err;
586 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
587 struct rtmsg *rtm = nlmsg_data(nlh);
588
589 arg.filter.flags = rtm->rtm_flags & (RTM_F_PREFIX|RTM_F_CLONED);
590 }
591
592 /* fib entries are never clones */
593 if (arg.filter.flags & RTM_F_CLONED)
594 goto out;
595
596 w = (void *)cb->args[2];
597 if (!w) {
598 /* New dump:
599 *
600 * 1. hook callback destructor.
601 */
602 cb->args[3] = (long)cb->done;
603 cb->done = fib6_dump_done;
604
605 /*
606 * 2. allocate and initialize walker.
607 */
608 w = kzalloc(sizeof(*w), GFP_ATOMIC);
609 if (!w)
610 return -ENOMEM;
611 w->func = fib6_dump_node;
612 cb->args[2] = (long)w;
613 }
614
615 arg.skb = skb;
616 arg.cb = cb;
617 arg.net = net;
618 w->args = &arg;
619
620 if (arg.filter.table_id) {
621 tb = fib6_get_table(net, arg.filter.table_id);
622 if (!tb) {
623 if (arg.filter.dump_all_families)
624 goto out;
625
626 NL_SET_ERR_MSG_MOD(cb->extack, "FIB table does not exist");
627 return -ENOENT;
628 }
629
630 res = fib6_dump_table(tb, skb, cb);
631 goto out;
632 }
633
634 s_h = cb->args[0];
635 s_e = cb->args[1];
636
637 rcu_read_lock();
638 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
639 e = 0;
640 head = &net->ipv6.fib_table_hash[h];
641 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
642 if (e < s_e)
643 goto next;
644 res = fib6_dump_table(tb, skb, cb);
645 if (res != 0)
646 goto out_unlock;
647 next:
648 e++;
649 }
650 }
651 out_unlock:
652 rcu_read_unlock();
653 cb->args[1] = e;
654 cb->args[0] = h;
655 out:
656 res = res < 0 ? res : skb->len;
657 if (res <= 0)
658 fib6_dump_end(cb);
659 return res;
660 }
661
662 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val)
663 {
664 if (!f6i)
665 return;
666
667 if (f6i->fib6_metrics == &dst_default_metrics) {
668 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC);
669
670 if (!p)
671 return;
672
673 refcount_set(&p->refcnt, 1);
674 f6i->fib6_metrics = p;
675 }
676
677 f6i->fib6_metrics->metrics[metric - 1] = val;
678 }
679
680 /*
681 * Routing Table
682 *
683 * return the appropriate node for a routing tree "add" operation
684 * by either creating and inserting or by returning an existing
685 * node.
686 */
687
688 static struct fib6_node *fib6_add_1(struct net *net,
689 struct fib6_table *table,
690 struct fib6_node *root,
691 struct in6_addr *addr, int plen,
692 int offset, int allow_create,
693 int replace_required,
694 struct netlink_ext_ack *extack)
695 {
696 struct fib6_node *fn, *in, *ln;
697 struct fib6_node *pn = NULL;
698 struct rt6key *key;
699 int bit;
700 __be32 dir = 0;
701
702 RT6_TRACE("fib6_add_1\n");
703
704 /* insert node in tree */
705
706 fn = root;
707
708 do {
709 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
710 lockdep_is_held(&table->tb6_lock));
711 key = (struct rt6key *)((u8 *)leaf + offset);
712
713 /*
714 * Prefix match
715 */
716 if (plen < fn->fn_bit ||
717 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
718 if (!allow_create) {
719 if (replace_required) {
720 NL_SET_ERR_MSG(extack,
721 "Can not replace route - no match found");
722 pr_warn("Can't replace route, no match found\n");
723 return ERR_PTR(-ENOENT);
724 }
725 pr_warn("NLM_F_CREATE should be set when creating new route\n");
726 }
727 goto insert_above;
728 }
729
730 /*
731 * Exact match ?
732 */
733
734 if (plen == fn->fn_bit) {
735 /* clean up an intermediate node */
736 if (!(fn->fn_flags & RTN_RTINFO)) {
737 RCU_INIT_POINTER(fn->leaf, NULL);
738 fib6_info_release(leaf);
739 /* remove null_entry in the root node */
740 } else if (fn->fn_flags & RTN_TL_ROOT &&
741 rcu_access_pointer(fn->leaf) ==
742 net->ipv6.fib6_null_entry) {
743 RCU_INIT_POINTER(fn->leaf, NULL);
744 }
745
746 return fn;
747 }
748
749 /*
750 * We have more bits to go
751 */
752
753 /* Try to walk down on tree. */
754 dir = addr_bit_set(addr, fn->fn_bit);
755 pn = fn;
756 fn = dir ?
757 rcu_dereference_protected(fn->right,
758 lockdep_is_held(&table->tb6_lock)) :
759 rcu_dereference_protected(fn->left,
760 lockdep_is_held(&table->tb6_lock));
761 } while (fn);
762
763 if (!allow_create) {
764 /* We should not create new node because
765 * NLM_F_REPLACE was specified without NLM_F_CREATE
766 * I assume it is safe to require NLM_F_CREATE when
767 * REPLACE flag is used! Later we may want to remove the
768 * check for replace_required, because according
769 * to netlink specification, NLM_F_CREATE
770 * MUST be specified if new route is created.
771 * That would keep IPv6 consistent with IPv4
772 */
773 if (replace_required) {
774 NL_SET_ERR_MSG(extack,
775 "Can not replace route - no match found");
776 pr_warn("Can't replace route, no match found\n");
777 return ERR_PTR(-ENOENT);
778 }
779 pr_warn("NLM_F_CREATE should be set when creating new route\n");
780 }
781 /*
782 * We walked to the bottom of tree.
783 * Create new leaf node without children.
784 */
785
786 ln = node_alloc(net);
787
788 if (!ln)
789 return ERR_PTR(-ENOMEM);
790 ln->fn_bit = plen;
791 RCU_INIT_POINTER(ln->parent, pn);
792
793 if (dir)
794 rcu_assign_pointer(pn->right, ln);
795 else
796 rcu_assign_pointer(pn->left, ln);
797
798 return ln;
799
800
801 insert_above:
802 /*
803 * split since we don't have a common prefix anymore or
804 * we have a less significant route.
805 * we've to insert an intermediate node on the list
806 * this new node will point to the one we need to create
807 * and the current
808 */
809
810 pn = rcu_dereference_protected(fn->parent,
811 lockdep_is_held(&table->tb6_lock));
812
813 /* find 1st bit in difference between the 2 addrs.
814
815 See comment in __ipv6_addr_diff: bit may be an invalid value,
816 but if it is >= plen, the value is ignored in any case.
817 */
818
819 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr));
820
821 /*
822 * (intermediate)[in]
823 * / \
824 * (new leaf node)[ln] (old node)[fn]
825 */
826 if (plen > bit) {
827 in = node_alloc(net);
828 ln = node_alloc(net);
829
830 if (!in || !ln) {
831 if (in)
832 node_free_immediate(net, in);
833 if (ln)
834 node_free_immediate(net, ln);
835 return ERR_PTR(-ENOMEM);
836 }
837
838 /*
839 * new intermediate node.
840 * RTN_RTINFO will
841 * be off since that an address that chooses one of
842 * the branches would not match less specific routes
843 * in the other branch
844 */
845
846 in->fn_bit = bit;
847
848 RCU_INIT_POINTER(in->parent, pn);
849 in->leaf = fn->leaf;
850 atomic_inc(&rcu_dereference_protected(in->leaf,
851 lockdep_is_held(&table->tb6_lock))->fib6_ref);
852
853 /* update parent pointer */
854 if (dir)
855 rcu_assign_pointer(pn->right, in);
856 else
857 rcu_assign_pointer(pn->left, in);
858
859 ln->fn_bit = plen;
860
861 RCU_INIT_POINTER(ln->parent, in);
862 rcu_assign_pointer(fn->parent, in);
863
864 if (addr_bit_set(addr, bit)) {
865 rcu_assign_pointer(in->right, ln);
866 rcu_assign_pointer(in->left, fn);
867 } else {
868 rcu_assign_pointer(in->left, ln);
869 rcu_assign_pointer(in->right, fn);
870 }
871 } else { /* plen <= bit */
872
873 /*
874 * (new leaf node)[ln]
875 * / \
876 * (old node)[fn] NULL
877 */
878
879 ln = node_alloc(net);
880
881 if (!ln)
882 return ERR_PTR(-ENOMEM);
883
884 ln->fn_bit = plen;
885
886 RCU_INIT_POINTER(ln->parent, pn);
887
888 if (addr_bit_set(&key->addr, plen))
889 RCU_INIT_POINTER(ln->right, fn);
890 else
891 RCU_INIT_POINTER(ln->left, fn);
892
893 rcu_assign_pointer(fn->parent, ln);
894
895 if (dir)
896 rcu_assign_pointer(pn->right, ln);
897 else
898 rcu_assign_pointer(pn->left, ln);
899 }
900 return ln;
901 }
902
903 static void fib6_drop_pcpu_from(struct fib6_info *f6i,
904 const struct fib6_table *table)
905 {
906 int cpu;
907
908 /* release the reference to this fib entry from
909 * all of its cached pcpu routes
910 */
911 for_each_possible_cpu(cpu) {
912 struct rt6_info **ppcpu_rt;
913 struct rt6_info *pcpu_rt;
914
915 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu);
916 pcpu_rt = *ppcpu_rt;
917 if (pcpu_rt) {
918 struct fib6_info *from;
919
920 from = rcu_dereference_protected(pcpu_rt->from,
921 lockdep_is_held(&table->tb6_lock));
922 rcu_assign_pointer(pcpu_rt->from, NULL);
923 fib6_info_release(from);
924 }
925 }
926 }
927
928 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,
929 struct net *net)
930 {
931 struct fib6_table *table = rt->fib6_table;
932
933 if (atomic_read(&rt->fib6_ref) != 1) {
934 /* This route is used as dummy address holder in some split
935 * nodes. It is not leaked, but it still holds other resources,
936 * which must be released in time. So, scan ascendant nodes
937 * and replace dummy references to this route with references
938 * to still alive ones.
939 */
940 while (fn) {
941 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
942 lockdep_is_held(&table->tb6_lock));
943 struct fib6_info *new_leaf;
944 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) {
945 new_leaf = fib6_find_prefix(net, table, fn);
946 atomic_inc(&new_leaf->fib6_ref);
947
948 rcu_assign_pointer(fn->leaf, new_leaf);
949 fib6_info_release(rt);
950 }
951 fn = rcu_dereference_protected(fn->parent,
952 lockdep_is_held(&table->tb6_lock));
953 }
954
955 if (rt->rt6i_pcpu)
956 fib6_drop_pcpu_from(rt, table);
957 }
958 }
959
960 /*
961 * Insert routing information in a node.
962 */
963
964 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
965 struct nl_info *info,
966 struct netlink_ext_ack *extack)
967 {
968 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
969 lockdep_is_held(&rt->fib6_table->tb6_lock));
970 struct fib6_info *iter = NULL;
971 struct fib6_info __rcu **ins;
972 struct fib6_info __rcu **fallback_ins = NULL;
973 int replace = (info->nlh &&
974 (info->nlh->nlmsg_flags & NLM_F_REPLACE));
975 int add = (!info->nlh ||
976 (info->nlh->nlmsg_flags & NLM_F_CREATE));
977 int found = 0;
978 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
979 u16 nlflags = NLM_F_EXCL;
980 int err;
981
982 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND))
983 nlflags |= NLM_F_APPEND;
984
985 ins = &fn->leaf;
986
987 for (iter = leaf; iter;
988 iter = rcu_dereference_protected(iter->fib6_next,
989 lockdep_is_held(&rt->fib6_table->tb6_lock))) {
990 /*
991 * Search for duplicates
992 */
993
994 if (iter->fib6_metric == rt->fib6_metric) {
995 /*
996 * Same priority level
997 */
998 if (info->nlh &&
999 (info->nlh->nlmsg_flags & NLM_F_EXCL))
1000 return -EEXIST;
1001
1002 nlflags &= ~NLM_F_EXCL;
1003 if (replace) {
1004 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) {
1005 found++;
1006 break;
1007 }
1008 if (rt_can_ecmp)
1009 fallback_ins = fallback_ins ?: ins;
1010 goto next_iter;
1011 }
1012
1013 if (rt6_duplicate_nexthop(iter, rt)) {
1014 if (rt->fib6_nsiblings)
1015 rt->fib6_nsiblings = 0;
1016 if (!(iter->fib6_flags & RTF_EXPIRES))
1017 return -EEXIST;
1018 if (!(rt->fib6_flags & RTF_EXPIRES))
1019 fib6_clean_expires(iter);
1020 else
1021 fib6_set_expires(iter, rt->expires);
1022
1023 if (rt->fib6_pmtu)
1024 fib6_metric_set(iter, RTAX_MTU,
1025 rt->fib6_pmtu);
1026 return -EEXIST;
1027 }
1028 /* If we have the same destination and the same metric,
1029 * but not the same gateway, then the route we try to
1030 * add is sibling to this route, increment our counter
1031 * of siblings, and later we will add our route to the
1032 * list.
1033 * Only static routes (which don't have flag
1034 * RTF_EXPIRES) are used for ECMPv6.
1035 *
1036 * To avoid long list, we only had siblings if the
1037 * route have a gateway.
1038 */
1039 if (rt_can_ecmp &&
1040 rt6_qualify_for_ecmp(iter))
1041 rt->fib6_nsiblings++;
1042 }
1043
1044 if (iter->fib6_metric > rt->fib6_metric)
1045 break;
1046
1047 next_iter:
1048 ins = &iter->fib6_next;
1049 }
1050
1051 if (fallback_ins && !found) {
1052 /* No ECMP-able route found, replace first non-ECMP one */
1053 ins = fallback_ins;
1054 iter = rcu_dereference_protected(*ins,
1055 lockdep_is_held(&rt->fib6_table->tb6_lock));
1056 found++;
1057 }
1058
1059 /* Reset round-robin state, if necessary */
1060 if (ins == &fn->leaf)
1061 fn->rr_ptr = NULL;
1062
1063 /* Link this route to others same route. */
1064 if (rt->fib6_nsiblings) {
1065 unsigned int fib6_nsiblings;
1066 struct fib6_info *sibling, *temp_sibling;
1067
1068 /* Find the first route that have the same metric */
1069 sibling = leaf;
1070 while (sibling) {
1071 if (sibling->fib6_metric == rt->fib6_metric &&
1072 rt6_qualify_for_ecmp(sibling)) {
1073 list_add_tail(&rt->fib6_siblings,
1074 &sibling->fib6_siblings);
1075 break;
1076 }
1077 sibling = rcu_dereference_protected(sibling->fib6_next,
1078 lockdep_is_held(&rt->fib6_table->tb6_lock));
1079 }
1080 /* For each sibling in the list, increment the counter of
1081 * siblings. BUG() if counters does not match, list of siblings
1082 * is broken!
1083 */
1084 fib6_nsiblings = 0;
1085 list_for_each_entry_safe(sibling, temp_sibling,
1086 &rt->fib6_siblings, fib6_siblings) {
1087 sibling->fib6_nsiblings++;
1088 BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings);
1089 fib6_nsiblings++;
1090 }
1091 BUG_ON(fib6_nsiblings != rt->fib6_nsiblings);
1092 rt6_multipath_rebalance(temp_sibling);
1093 }
1094
1095 /*
1096 * insert node
1097 */
1098 if (!replace) {
1099 if (!add)
1100 pr_warn("NLM_F_CREATE should be set when creating new route\n");
1101
1102 add:
1103 nlflags |= NLM_F_CREATE;
1104
1105 err = call_fib6_entry_notifiers(info->nl_net,
1106 FIB_EVENT_ENTRY_ADD,
1107 rt, extack);
1108 if (err)
1109 return err;
1110
1111 rcu_assign_pointer(rt->fib6_next, iter);
1112 atomic_inc(&rt->fib6_ref);
1113 rcu_assign_pointer(rt->fib6_node, fn);
1114 rcu_assign_pointer(*ins, rt);
1115 if (!info->skip_notify)
1116 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
1117 info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
1118
1119 if (!(fn->fn_flags & RTN_RTINFO)) {
1120 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
1121 fn->fn_flags |= RTN_RTINFO;
1122 }
1123
1124 } else {
1125 int nsiblings;
1126
1127 if (!found) {
1128 if (add)
1129 goto add;
1130 pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
1131 return -ENOENT;
1132 }
1133
1134 err = call_fib6_entry_notifiers(info->nl_net,
1135 FIB_EVENT_ENTRY_REPLACE,
1136 rt, extack);
1137 if (err)
1138 return err;
1139
1140 atomic_inc(&rt->fib6_ref);
1141 rcu_assign_pointer(rt->fib6_node, fn);
1142 rt->fib6_next = iter->fib6_next;
1143 rcu_assign_pointer(*ins, rt);
1144 if (!info->skip_notify)
1145 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE);
1146 if (!(fn->fn_flags & RTN_RTINFO)) {
1147 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
1148 fn->fn_flags |= RTN_RTINFO;
1149 }
1150 nsiblings = iter->fib6_nsiblings;
1151 iter->fib6_node = NULL;
1152 fib6_purge_rt(iter, fn, info->nl_net);
1153 if (rcu_access_pointer(fn->rr_ptr) == iter)
1154 fn->rr_ptr = NULL;
1155 fib6_info_release(iter);
1156
1157 if (nsiblings) {
1158 /* Replacing an ECMP route, remove all siblings */
1159 ins = &rt->fib6_next;
1160 iter = rcu_dereference_protected(*ins,
1161 lockdep_is_held(&rt->fib6_table->tb6_lock));
1162 while (iter) {
1163 if (iter->fib6_metric > rt->fib6_metric)
1164 break;
1165 if (rt6_qualify_for_ecmp(iter)) {
1166 *ins = iter->fib6_next;
1167 iter->fib6_node = NULL;
1168 fib6_purge_rt(iter, fn, info->nl_net);
1169 if (rcu_access_pointer(fn->rr_ptr) == iter)
1170 fn->rr_ptr = NULL;
1171 fib6_info_release(iter);
1172 nsiblings--;
1173 info->nl_net->ipv6.rt6_stats->fib_rt_entries--;
1174 } else {
1175 ins = &iter->fib6_next;
1176 }
1177 iter = rcu_dereference_protected(*ins,
1178 lockdep_is_held(&rt->fib6_table->tb6_lock));
1179 }
1180 WARN_ON(nsiblings != 0);
1181 }
1182 }
1183
1184 return 0;
1185 }
1186
1187 static void fib6_start_gc(struct net *net, struct fib6_info *rt)
1188 {
1189 if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
1190 (rt->fib6_flags & RTF_EXPIRES))
1191 mod_timer(&net->ipv6.ip6_fib_timer,
1192 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
1193 }
1194
1195 void fib6_force_start_gc(struct net *net)
1196 {
1197 if (!timer_pending(&net->ipv6.ip6_fib_timer))
1198 mod_timer(&net->ipv6.ip6_fib_timer,
1199 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
1200 }
1201
1202 static void __fib6_update_sernum_upto_root(struct fib6_info *rt,
1203 int sernum)
1204 {
1205 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node,
1206 lockdep_is_held(&rt->fib6_table->tb6_lock));
1207
1208 /* paired with smp_rmb() in rt6_get_cookie_safe() */
1209 smp_wmb();
1210 while (fn) {
1211 fn->fn_sernum = sernum;
1212 fn = rcu_dereference_protected(fn->parent,
1213 lockdep_is_held(&rt->fib6_table->tb6_lock));
1214 }
1215 }
1216
1217 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt)
1218 {
1219 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net));
1220 }
1221
1222 /*
1223 * Add routing information to the routing tree.
1224 * <destination addr>/<source addr>
1225 * with source addr info in sub-trees
1226 * Need to own table->tb6_lock
1227 */
1228
1229 int fib6_add(struct fib6_node *root, struct fib6_info *rt,
1230 struct nl_info *info, struct netlink_ext_ack *extack)
1231 {
1232 struct fib6_table *table = rt->fib6_table;
1233 struct fib6_node *fn, *pn = NULL;
1234 int err = -ENOMEM;
1235 int allow_create = 1;
1236 int replace_required = 0;
1237 int sernum = fib6_new_sernum(info->nl_net);
1238
1239 if (info->nlh) {
1240 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
1241 allow_create = 0;
1242 if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
1243 replace_required = 1;
1244 }
1245 if (!allow_create && !replace_required)
1246 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
1247
1248 fn = fib6_add_1(info->nl_net, table, root,
1249 &rt->fib6_dst.addr, rt->fib6_dst.plen,
1250 offsetof(struct fib6_info, fib6_dst), allow_create,
1251 replace_required, extack);
1252 if (IS_ERR(fn)) {
1253 err = PTR_ERR(fn);
1254 fn = NULL;
1255 goto out;
1256 }
1257
1258 pn = fn;
1259
1260 #ifdef CONFIG_IPV6_SUBTREES
1261 if (rt->fib6_src.plen) {
1262 struct fib6_node *sn;
1263
1264 if (!rcu_access_pointer(fn->subtree)) {
1265 struct fib6_node *sfn;
1266
1267 /*
1268 * Create subtree.
1269 *
1270 * fn[main tree]
1271 * |
1272 * sfn[subtree root]
1273 * \
1274 * sn[new leaf node]
1275 */
1276
1277 /* Create subtree root node */
1278 sfn = node_alloc(info->nl_net);
1279 if (!sfn)
1280 goto failure;
1281
1282 atomic_inc(&info->nl_net->ipv6.fib6_null_entry->fib6_ref);
1283 rcu_assign_pointer(sfn->leaf,
1284 info->nl_net->ipv6.fib6_null_entry);
1285 sfn->fn_flags = RTN_ROOT;
1286
1287 /* Now add the first leaf node to new subtree */
1288
1289 sn = fib6_add_1(info->nl_net, table, sfn,
1290 &rt->fib6_src.addr, rt->fib6_src.plen,
1291 offsetof(struct fib6_info, fib6_src),
1292 allow_create, replace_required, extack);
1293
1294 if (IS_ERR(sn)) {
1295 /* If it is failed, discard just allocated
1296 root, and then (in failure) stale node
1297 in main tree.
1298 */
1299 node_free_immediate(info->nl_net, sfn);
1300 err = PTR_ERR(sn);
1301 goto failure;
1302 }
1303
1304 /* Now link new subtree to main tree */
1305 rcu_assign_pointer(sfn->parent, fn);
1306 rcu_assign_pointer(fn->subtree, sfn);
1307 } else {
1308 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn),
1309 &rt->fib6_src.addr, rt->fib6_src.plen,
1310 offsetof(struct fib6_info, fib6_src),
1311 allow_create, replace_required, extack);
1312
1313 if (IS_ERR(sn)) {
1314 err = PTR_ERR(sn);
1315 goto failure;
1316 }
1317 }
1318
1319 if (!rcu_access_pointer(fn->leaf)) {
1320 if (fn->fn_flags & RTN_TL_ROOT) {
1321 /* put back null_entry for root node */
1322 rcu_assign_pointer(fn->leaf,
1323 info->nl_net->ipv6.fib6_null_entry);
1324 } else {
1325 atomic_inc(&rt->fib6_ref);
1326 rcu_assign_pointer(fn->leaf, rt);
1327 }
1328 }
1329 fn = sn;
1330 }
1331 #endif
1332
1333 err = fib6_add_rt2node(fn, rt, info, extack);
1334 if (!err) {
1335 __fib6_update_sernum_upto_root(rt, sernum);
1336 fib6_start_gc(info->nl_net, rt);
1337 }
1338
1339 out:
1340 if (err) {
1341 #ifdef CONFIG_IPV6_SUBTREES
1342 /*
1343 * If fib6_add_1 has cleared the old leaf pointer in the
1344 * super-tree leaf node we have to find a new one for it.
1345 */
1346 if (pn != fn) {
1347 struct fib6_info *pn_leaf =
1348 rcu_dereference_protected(pn->leaf,
1349 lockdep_is_held(&table->tb6_lock));
1350 if (pn_leaf == rt) {
1351 pn_leaf = NULL;
1352 RCU_INIT_POINTER(pn->leaf, NULL);
1353 fib6_info_release(rt);
1354 }
1355 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) {
1356 pn_leaf = fib6_find_prefix(info->nl_net, table,
1357 pn);
1358 #if RT6_DEBUG >= 2
1359 if (!pn_leaf) {
1360 WARN_ON(!pn_leaf);
1361 pn_leaf =
1362 info->nl_net->ipv6.fib6_null_entry;
1363 }
1364 #endif
1365 fib6_info_hold(pn_leaf);
1366 rcu_assign_pointer(pn->leaf, pn_leaf);
1367 }
1368 }
1369 #endif
1370 goto failure;
1371 }
1372 return err;
1373
1374 failure:
1375 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if:
1376 * 1. fn is an intermediate node and we failed to add the new
1377 * route to it in both subtree creation failure and fib6_add_rt2node()
1378 * failure case.
1379 * 2. fn is the root node in the table and we fail to add the first
1380 * default route to it.
1381 */
1382 if (fn &&
1383 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) ||
1384 (fn->fn_flags & RTN_TL_ROOT &&
1385 !rcu_access_pointer(fn->leaf))))
1386 fib6_repair_tree(info->nl_net, table, fn);
1387 return err;
1388 }
1389
1390 /*
1391 * Routing tree lookup
1392 *
1393 */
1394
1395 struct lookup_args {
1396 int offset; /* key offset on fib6_info */
1397 const struct in6_addr *addr; /* search key */
1398 };
1399
1400 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root,
1401 struct lookup_args *args)
1402 {
1403 struct fib6_node *fn;
1404 __be32 dir;
1405
1406 if (unlikely(args->offset == 0))
1407 return NULL;
1408
1409 /*
1410 * Descend on a tree
1411 */
1412
1413 fn = root;
1414
1415 for (;;) {
1416 struct fib6_node *next;
1417
1418 dir = addr_bit_set(args->addr, fn->fn_bit);
1419
1420 next = dir ? rcu_dereference(fn->right) :
1421 rcu_dereference(fn->left);
1422
1423 if (next) {
1424 fn = next;
1425 continue;
1426 }
1427 break;
1428 }
1429
1430 while (fn) {
1431 struct fib6_node *subtree = FIB6_SUBTREE(fn);
1432
1433 if (subtree || fn->fn_flags & RTN_RTINFO) {
1434 struct fib6_info *leaf = rcu_dereference(fn->leaf);
1435 struct rt6key *key;
1436
1437 if (!leaf)
1438 goto backtrack;
1439
1440 key = (struct rt6key *) ((u8 *)leaf + args->offset);
1441
1442 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
1443 #ifdef CONFIG_IPV6_SUBTREES
1444 if (subtree) {
1445 struct fib6_node *sfn;
1446 sfn = fib6_node_lookup_1(subtree,
1447 args + 1);
1448 if (!sfn)
1449 goto backtrack;
1450 fn = sfn;
1451 }
1452 #endif
1453 if (fn->fn_flags & RTN_RTINFO)
1454 return fn;
1455 }
1456 }
1457 backtrack:
1458 if (fn->fn_flags & RTN_ROOT)
1459 break;
1460
1461 fn = rcu_dereference(fn->parent);
1462 }
1463
1464 return NULL;
1465 }
1466
1467 /* called with rcu_read_lock() held
1468 */
1469 struct fib6_node *fib6_node_lookup(struct fib6_node *root,
1470 const struct in6_addr *daddr,
1471 const struct in6_addr *saddr)
1472 {
1473 struct fib6_node *fn;
1474 struct lookup_args args[] = {
1475 {
1476 .offset = offsetof(struct fib6_info, fib6_dst),
1477 .addr = daddr,
1478 },
1479 #ifdef CONFIG_IPV6_SUBTREES
1480 {
1481 .offset = offsetof(struct fib6_info, fib6_src),
1482 .addr = saddr,
1483 },
1484 #endif
1485 {
1486 .offset = 0, /* sentinel */
1487 }
1488 };
1489
1490 fn = fib6_node_lookup_1(root, daddr ? args : args + 1);
1491 if (!fn || fn->fn_flags & RTN_TL_ROOT)
1492 fn = root;
1493
1494 return fn;
1495 }
1496
1497 /*
1498 * Get node with specified destination prefix (and source prefix,
1499 * if subtrees are used)
1500 * exact_match == true means we try to find fn with exact match of
1501 * the passed in prefix addr
1502 * exact_match == false means we try to find fn with longest prefix
1503 * match of the passed in prefix addr. This is useful for finding fn
1504 * for cached route as it will be stored in the exception table under
1505 * the node with longest prefix length.
1506 */
1507
1508
1509 static struct fib6_node *fib6_locate_1(struct fib6_node *root,
1510 const struct in6_addr *addr,
1511 int plen, int offset,
1512 bool exact_match)
1513 {
1514 struct fib6_node *fn, *prev = NULL;
1515
1516 for (fn = root; fn ; ) {
1517 struct fib6_info *leaf = rcu_dereference(fn->leaf);
1518 struct rt6key *key;
1519
1520 /* This node is being deleted */
1521 if (!leaf) {
1522 if (plen <= fn->fn_bit)
1523 goto out;
1524 else
1525 goto next;
1526 }
1527
1528 key = (struct rt6key *)((u8 *)leaf + offset);
1529
1530 /*
1531 * Prefix match
1532 */
1533 if (plen < fn->fn_bit ||
1534 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
1535 goto out;
1536
1537 if (plen == fn->fn_bit)
1538 return fn;
1539
1540 prev = fn;
1541
1542 next:
1543 /*
1544 * We have more bits to go
1545 */
1546 if (addr_bit_set(addr, fn->fn_bit))
1547 fn = rcu_dereference(fn->right);
1548 else
1549 fn = rcu_dereference(fn->left);
1550 }
1551 out:
1552 if (exact_match)
1553 return NULL;
1554 else
1555 return prev;
1556 }
1557
1558 struct fib6_node *fib6_locate(struct fib6_node *root,
1559 const struct in6_addr *daddr, int dst_len,
1560 const struct in6_addr *saddr, int src_len,
1561 bool exact_match)
1562 {
1563 struct fib6_node *fn;
1564
1565 fn = fib6_locate_1(root, daddr, dst_len,
1566 offsetof(struct fib6_info, fib6_dst),
1567 exact_match);
1568
1569 #ifdef CONFIG_IPV6_SUBTREES
1570 if (src_len) {
1571 WARN_ON(saddr == NULL);
1572 if (fn) {
1573 struct fib6_node *subtree = FIB6_SUBTREE(fn);
1574
1575 if (subtree) {
1576 fn = fib6_locate_1(subtree, saddr, src_len,
1577 offsetof(struct fib6_info, fib6_src),
1578 exact_match);
1579 }
1580 }
1581 }
1582 #endif
1583
1584 if (fn && fn->fn_flags & RTN_RTINFO)
1585 return fn;
1586
1587 return NULL;
1588 }
1589
1590
1591 /*
1592 * Deletion
1593 *
1594 */
1595
1596 static struct fib6_info *fib6_find_prefix(struct net *net,
1597 struct fib6_table *table,
1598 struct fib6_node *fn)
1599 {
1600 struct fib6_node *child_left, *child_right;
1601
1602 if (fn->fn_flags & RTN_ROOT)
1603 return net->ipv6.fib6_null_entry;
1604
1605 while (fn) {
1606 child_left = rcu_dereference_protected(fn->left,
1607 lockdep_is_held(&table->tb6_lock));
1608 child_right = rcu_dereference_protected(fn->right,
1609 lockdep_is_held(&table->tb6_lock));
1610 if (child_left)
1611 return rcu_dereference_protected(child_left->leaf,
1612 lockdep_is_held(&table->tb6_lock));
1613 if (child_right)
1614 return rcu_dereference_protected(child_right->leaf,
1615 lockdep_is_held(&table->tb6_lock));
1616
1617 fn = FIB6_SUBTREE(fn);
1618 }
1619 return NULL;
1620 }
1621
1622 /*
1623 * Called to trim the tree of intermediate nodes when possible. "fn"
1624 * is the node we want to try and remove.
1625 * Need to own table->tb6_lock
1626 */
1627
1628 static struct fib6_node *fib6_repair_tree(struct net *net,
1629 struct fib6_table *table,
1630 struct fib6_node *fn)
1631 {
1632 int children;
1633 int nstate;
1634 struct fib6_node *child;
1635 struct fib6_walker *w;
1636 int iter = 0;
1637
1638 /* Set fn->leaf to null_entry for root node. */
1639 if (fn->fn_flags & RTN_TL_ROOT) {
1640 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry);
1641 return fn;
1642 }
1643
1644 for (;;) {
1645 struct fib6_node *fn_r = rcu_dereference_protected(fn->right,
1646 lockdep_is_held(&table->tb6_lock));
1647 struct fib6_node *fn_l = rcu_dereference_protected(fn->left,
1648 lockdep_is_held(&table->tb6_lock));
1649 struct fib6_node *pn = rcu_dereference_protected(fn->parent,
1650 lockdep_is_held(&table->tb6_lock));
1651 struct fib6_node *pn_r = rcu_dereference_protected(pn->right,
1652 lockdep_is_held(&table->tb6_lock));
1653 struct fib6_node *pn_l = rcu_dereference_protected(pn->left,
1654 lockdep_is_held(&table->tb6_lock));
1655 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf,
1656 lockdep_is_held(&table->tb6_lock));
1657 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf,
1658 lockdep_is_held(&table->tb6_lock));
1659 struct fib6_info *new_fn_leaf;
1660
1661 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1662 iter++;
1663
1664 WARN_ON(fn->fn_flags & RTN_RTINFO);
1665 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1666 WARN_ON(fn_leaf);
1667
1668 children = 0;
1669 child = NULL;
1670 if (fn_r)
1671 child = fn_r, children |= 1;
1672 if (fn_l)
1673 child = fn_l, children |= 2;
1674
1675 if (children == 3 || FIB6_SUBTREE(fn)
1676 #ifdef CONFIG_IPV6_SUBTREES
1677 /* Subtree root (i.e. fn) may have one child */
1678 || (children && fn->fn_flags & RTN_ROOT)
1679 #endif
1680 ) {
1681 new_fn_leaf = fib6_find_prefix(net, table, fn);
1682 #if RT6_DEBUG >= 2
1683 if (!new_fn_leaf) {
1684 WARN_ON(!new_fn_leaf);
1685 new_fn_leaf = net->ipv6.fib6_null_entry;
1686 }
1687 #endif
1688 fib6_info_hold(new_fn_leaf);
1689 rcu_assign_pointer(fn->leaf, new_fn_leaf);
1690 return pn;
1691 }
1692
1693 #ifdef CONFIG_IPV6_SUBTREES
1694 if (FIB6_SUBTREE(pn) == fn) {
1695 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1696 RCU_INIT_POINTER(pn->subtree, NULL);
1697 nstate = FWS_L;
1698 } else {
1699 WARN_ON(fn->fn_flags & RTN_ROOT);
1700 #endif
1701 if (pn_r == fn)
1702 rcu_assign_pointer(pn->right, child);
1703 else if (pn_l == fn)
1704 rcu_assign_pointer(pn->left, child);
1705 #if RT6_DEBUG >= 2
1706 else
1707 WARN_ON(1);
1708 #endif
1709 if (child)
1710 rcu_assign_pointer(child->parent, pn);
1711 nstate = FWS_R;
1712 #ifdef CONFIG_IPV6_SUBTREES
1713 }
1714 #endif
1715
1716 read_lock(&net->ipv6.fib6_walker_lock);
1717 FOR_WALKERS(net, w) {
1718 if (!child) {
1719 if (w->node == fn) {
1720 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1721 w->node = pn;
1722 w->state = nstate;
1723 }
1724 } else {
1725 if (w->node == fn) {
1726 w->node = child;
1727 if (children&2) {
1728 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1729 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT;
1730 } else {
1731 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1732 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT;
1733 }
1734 }
1735 }
1736 }
1737 read_unlock(&net->ipv6.fib6_walker_lock);
1738
1739 node_free(net, fn);
1740 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
1741 return pn;
1742
1743 RCU_INIT_POINTER(pn->leaf, NULL);
1744 fib6_info_release(pn_leaf);
1745 fn = pn;
1746 }
1747 }
1748
1749 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
1750 struct fib6_info __rcu **rtp, struct nl_info *info)
1751 {
1752 struct fib6_walker *w;
1753 struct fib6_info *rt = rcu_dereference_protected(*rtp,
1754 lockdep_is_held(&table->tb6_lock));
1755 struct net *net = info->nl_net;
1756
1757 RT6_TRACE("fib6_del_route\n");
1758
1759 /* Unlink it */
1760 *rtp = rt->fib6_next;
1761 rt->fib6_node = NULL;
1762 net->ipv6.rt6_stats->fib_rt_entries--;
1763 net->ipv6.rt6_stats->fib_discarded_routes++;
1764
1765 /* Flush all cached dst in exception table */
1766 rt6_flush_exceptions(rt);
1767
1768 /* Reset round-robin state, if necessary */
1769 if (rcu_access_pointer(fn->rr_ptr) == rt)
1770 fn->rr_ptr = NULL;
1771
1772 /* Remove this entry from other siblings */
1773 if (rt->fib6_nsiblings) {
1774 struct fib6_info *sibling, *next_sibling;
1775
1776 list_for_each_entry_safe(sibling, next_sibling,
1777 &rt->fib6_siblings, fib6_siblings)
1778 sibling->fib6_nsiblings--;
1779 rt->fib6_nsiblings = 0;
1780 list_del_init(&rt->fib6_siblings);
1781 rt6_multipath_rebalance(next_sibling);
1782 }
1783
1784 /* Adjust walkers */
1785 read_lock(&net->ipv6.fib6_walker_lock);
1786 FOR_WALKERS(net, w) {
1787 if (w->state == FWS_C && w->leaf == rt) {
1788 RT6_TRACE("walker %p adjusted by delroute\n", w);
1789 w->leaf = rcu_dereference_protected(rt->fib6_next,
1790 lockdep_is_held(&table->tb6_lock));
1791 if (!w->leaf)
1792 w->state = FWS_U;
1793 }
1794 }
1795 read_unlock(&net->ipv6.fib6_walker_lock);
1796
1797 /* If it was last route, call fib6_repair_tree() to:
1798 * 1. For root node, put back null_entry as how the table was created.
1799 * 2. For other nodes, expunge its radix tree node.
1800 */
1801 if (!rcu_access_pointer(fn->leaf)) {
1802 if (!(fn->fn_flags & RTN_TL_ROOT)) {
1803 fn->fn_flags &= ~RTN_RTINFO;
1804 net->ipv6.rt6_stats->fib_route_nodes--;
1805 }
1806 fn = fib6_repair_tree(net, table, fn);
1807 }
1808
1809 fib6_purge_rt(rt, fn, net);
1810
1811 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL);
1812 if (!info->skip_notify)
1813 inet6_rt_notify(RTM_DELROUTE, rt, info, 0);
1814 fib6_info_release(rt);
1815 }
1816
1817 /* Need to own table->tb6_lock */
1818 int fib6_del(struct fib6_info *rt, struct nl_info *info)
1819 {
1820 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node,
1821 lockdep_is_held(&rt->fib6_table->tb6_lock));
1822 struct fib6_table *table = rt->fib6_table;
1823 struct net *net = info->nl_net;
1824 struct fib6_info __rcu **rtp;
1825 struct fib6_info __rcu **rtp_next;
1826
1827 if (!fn || rt == net->ipv6.fib6_null_entry)
1828 return -ENOENT;
1829
1830 WARN_ON(!(fn->fn_flags & RTN_RTINFO));
1831
1832 /*
1833 * Walk the leaf entries looking for ourself
1834 */
1835
1836 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) {
1837 struct fib6_info *cur = rcu_dereference_protected(*rtp,
1838 lockdep_is_held(&table->tb6_lock));
1839 if (rt == cur) {
1840 fib6_del_route(table, fn, rtp, info);
1841 return 0;
1842 }
1843 rtp_next = &cur->fib6_next;
1844 }
1845 return -ENOENT;
1846 }
1847
1848 /*
1849 * Tree traversal function.
1850 *
1851 * Certainly, it is not interrupt safe.
1852 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1853 * It means, that we can modify tree during walking
1854 * and use this function for garbage collection, clone pruning,
1855 * cleaning tree when a device goes down etc. etc.
1856 *
1857 * It guarantees that every node will be traversed,
1858 * and that it will be traversed only once.
1859 *
1860 * Callback function w->func may return:
1861 * 0 -> continue walking.
1862 * positive value -> walking is suspended (used by tree dumps,
1863 * and probably by gc, if it will be split to several slices)
1864 * negative value -> terminate walking.
1865 *
1866 * The function itself returns:
1867 * 0 -> walk is complete.
1868 * >0 -> walk is incomplete (i.e. suspended)
1869 * <0 -> walk is terminated by an error.
1870 *
1871 * This function is called with tb6_lock held.
1872 */
1873
1874 static int fib6_walk_continue(struct fib6_walker *w)
1875 {
1876 struct fib6_node *fn, *pn, *left, *right;
1877
1878 /* w->root should always be table->tb6_root */
1879 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT));
1880
1881 for (;;) {
1882 fn = w->node;
1883 if (!fn)
1884 return 0;
1885
1886 switch (w->state) {
1887 #ifdef CONFIG_IPV6_SUBTREES
1888 case FWS_S:
1889 if (FIB6_SUBTREE(fn)) {
1890 w->node = FIB6_SUBTREE(fn);
1891 continue;
1892 }
1893 w->state = FWS_L;
1894 #endif
1895 /* fall through */
1896 case FWS_L:
1897 left = rcu_dereference_protected(fn->left, 1);
1898 if (left) {
1899 w->node = left;
1900 w->state = FWS_INIT;
1901 continue;
1902 }
1903 w->state = FWS_R;
1904 /* fall through */
1905 case FWS_R:
1906 right = rcu_dereference_protected(fn->right, 1);
1907 if (right) {
1908 w->node = right;
1909 w->state = FWS_INIT;
1910 continue;
1911 }
1912 w->state = FWS_C;
1913 w->leaf = rcu_dereference_protected(fn->leaf, 1);
1914 /* fall through */
1915 case FWS_C:
1916 if (w->leaf && fn->fn_flags & RTN_RTINFO) {
1917 int err;
1918
1919 if (w->skip) {
1920 w->skip--;
1921 goto skip;
1922 }
1923
1924 err = w->func(w);
1925 if (err)
1926 return err;
1927
1928 w->count++;
1929 continue;
1930 }
1931 skip:
1932 w->state = FWS_U;
1933 /* fall through */
1934 case FWS_U:
1935 if (fn == w->root)
1936 return 0;
1937 pn = rcu_dereference_protected(fn->parent, 1);
1938 left = rcu_dereference_protected(pn->left, 1);
1939 right = rcu_dereference_protected(pn->right, 1);
1940 w->node = pn;
1941 #ifdef CONFIG_IPV6_SUBTREES
1942 if (FIB6_SUBTREE(pn) == fn) {
1943 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1944 w->state = FWS_L;
1945 continue;
1946 }
1947 #endif
1948 if (left == fn) {
1949 w->state = FWS_R;
1950 continue;
1951 }
1952 if (right == fn) {
1953 w->state = FWS_C;
1954 w->leaf = rcu_dereference_protected(w->node->leaf, 1);
1955 continue;
1956 }
1957 #if RT6_DEBUG >= 2
1958 WARN_ON(1);
1959 #endif
1960 }
1961 }
1962 }
1963
1964 static int fib6_walk(struct net *net, struct fib6_walker *w)
1965 {
1966 int res;
1967
1968 w->state = FWS_INIT;
1969 w->node = w->root;
1970
1971 fib6_walker_link(net, w);
1972 res = fib6_walk_continue(w);
1973 if (res <= 0)
1974 fib6_walker_unlink(net, w);
1975 return res;
1976 }
1977
1978 static int fib6_clean_node(struct fib6_walker *w)
1979 {
1980 int res;
1981 struct fib6_info *rt;
1982 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w);
1983 struct nl_info info = {
1984 .nl_net = c->net,
1985 .skip_notify = c->skip_notify,
1986 };
1987
1988 if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
1989 w->node->fn_sernum != c->sernum)
1990 w->node->fn_sernum = c->sernum;
1991
1992 if (!c->func) {
1993 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE);
1994 w->leaf = NULL;
1995 return 0;
1996 }
1997
1998 for_each_fib6_walker_rt(w) {
1999 res = c->func(rt, c->arg);
2000 if (res == -1) {
2001 w->leaf = rt;
2002 res = fib6_del(rt, &info);
2003 if (res) {
2004 #if RT6_DEBUG >= 2
2005 pr_debug("%s: del failed: rt=%p@%p err=%d\n",
2006 __func__, rt,
2007 rcu_access_pointer(rt->fib6_node),
2008 res);
2009 #endif
2010 continue;
2011 }
2012 return 0;
2013 } else if (res == -2) {
2014 if (WARN_ON(!rt->fib6_nsiblings))
2015 continue;
2016 rt = list_last_entry(&rt->fib6_siblings,
2017 struct fib6_info, fib6_siblings);
2018 continue;
2019 }
2020 WARN_ON(res != 0);
2021 }
2022 w->leaf = rt;
2023 return 0;
2024 }
2025
2026 /*
2027 * Convenient frontend to tree walker.
2028 *
2029 * func is called on each route.
2030 * It may return -2 -> skip multipath route.
2031 * -1 -> delete this route.
2032 * 0 -> continue walking
2033 */
2034
2035 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
2036 int (*func)(struct fib6_info *, void *arg),
2037 int sernum, void *arg, bool skip_notify)
2038 {
2039 struct fib6_cleaner c;
2040
2041 c.w.root = root;
2042 c.w.func = fib6_clean_node;
2043 c.w.count = 0;
2044 c.w.skip = 0;
2045 c.func = func;
2046 c.sernum = sernum;
2047 c.arg = arg;
2048 c.net = net;
2049 c.skip_notify = skip_notify;
2050
2051 fib6_walk(net, &c.w);
2052 }
2053
2054 static void __fib6_clean_all(struct net *net,
2055 int (*func)(struct fib6_info *, void *),
2056 int sernum, void *arg, bool skip_notify)
2057 {
2058 struct fib6_table *table;
2059 struct hlist_head *head;
2060 unsigned int h;
2061
2062 rcu_read_lock();
2063 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
2064 head = &net->ipv6.fib_table_hash[h];
2065 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
2066 spin_lock_bh(&table->tb6_lock);
2067 fib6_clean_tree(net, &table->tb6_root,
2068 func, sernum, arg, skip_notify);
2069 spin_unlock_bh(&table->tb6_lock);
2070 }
2071 }
2072 rcu_read_unlock();
2073 }
2074
2075 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *),
2076 void *arg)
2077 {
2078 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, false);
2079 }
2080
2081 void fib6_clean_all_skip_notify(struct net *net,
2082 int (*func)(struct fib6_info *, void *),
2083 void *arg)
2084 {
2085 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, true);
2086 }
2087
2088 static void fib6_flush_trees(struct net *net)
2089 {
2090 int new_sernum = fib6_new_sernum(net);
2091
2092 __fib6_clean_all(net, NULL, new_sernum, NULL, false);
2093 }
2094
2095 /*
2096 * Garbage collection
2097 */
2098
2099 static int fib6_age(struct fib6_info *rt, void *arg)
2100 {
2101 struct fib6_gc_args *gc_args = arg;
2102 unsigned long now = jiffies;
2103
2104 /*
2105 * check addrconf expiration here.
2106 * Routes are expired even if they are in use.
2107 */
2108
2109 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) {
2110 if (time_after(now, rt->expires)) {
2111 RT6_TRACE("expiring %p\n", rt);
2112 return -1;
2113 }
2114 gc_args->more++;
2115 }
2116
2117 /* Also age clones in the exception table.
2118 * Note, that clones are aged out
2119 * only if they are not in use now.
2120 */
2121 rt6_age_exceptions(rt, gc_args, now);
2122
2123 return 0;
2124 }
2125
2126 void fib6_run_gc(unsigned long expires, struct net *net, bool force)
2127 {
2128 struct fib6_gc_args gc_args;
2129 unsigned long now;
2130
2131 if (force) {
2132 spin_lock_bh(&net->ipv6.fib6_gc_lock);
2133 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) {
2134 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
2135 return;
2136 }
2137 gc_args.timeout = expires ? (int)expires :
2138 net->ipv6.sysctl.ip6_rt_gc_interval;
2139 gc_args.more = 0;
2140
2141 fib6_clean_all(net, fib6_age, &gc_args);
2142 now = jiffies;
2143 net->ipv6.ip6_rt_last_gc = now;
2144
2145 if (gc_args.more)
2146 mod_timer(&net->ipv6.ip6_fib_timer,
2147 round_jiffies(now
2148 + net->ipv6.sysctl.ip6_rt_gc_interval));
2149 else
2150 del_timer(&net->ipv6.ip6_fib_timer);
2151 spin_unlock_bh(&net->ipv6.fib6_gc_lock);
2152 }
2153
2154 static void fib6_gc_timer_cb(struct timer_list *t)
2155 {
2156 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer);
2157
2158 fib6_run_gc(0, arg, true);
2159 }
2160
2161 static int __net_init fib6_net_init(struct net *net)
2162 {
2163 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
2164 int err;
2165
2166 err = fib6_notifier_init(net);
2167 if (err)
2168 return err;
2169
2170 spin_lock_init(&net->ipv6.fib6_gc_lock);
2171 rwlock_init(&net->ipv6.fib6_walker_lock);
2172 INIT_LIST_HEAD(&net->ipv6.fib6_walkers);
2173 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0);
2174
2175 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
2176 if (!net->ipv6.rt6_stats)
2177 goto out_timer;
2178
2179 /* Avoid false sharing : Use at least a full cache line */
2180 size = max_t(size_t, size, L1_CACHE_BYTES);
2181
2182 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
2183 if (!net->ipv6.fib_table_hash)
2184 goto out_rt6_stats;
2185
2186 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
2187 GFP_KERNEL);
2188 if (!net->ipv6.fib6_main_tbl)
2189 goto out_fib_table_hash;
2190
2191 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
2192 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf,
2193 net->ipv6.fib6_null_entry);
2194 net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
2195 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
2196 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
2197
2198 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2199 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
2200 GFP_KERNEL);
2201 if (!net->ipv6.fib6_local_tbl)
2202 goto out_fib6_main_tbl;
2203 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
2204 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf,
2205 net->ipv6.fib6_null_entry);
2206 net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
2207 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
2208 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
2209 #endif
2210 fib6_tables_init(net);
2211
2212 return 0;
2213
2214 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2215 out_fib6_main_tbl:
2216 kfree(net->ipv6.fib6_main_tbl);
2217 #endif
2218 out_fib_table_hash:
2219 kfree(net->ipv6.fib_table_hash);
2220 out_rt6_stats:
2221 kfree(net->ipv6.rt6_stats);
2222 out_timer:
2223 fib6_notifier_exit(net);
2224 return -ENOMEM;
2225 }
2226
2227 static void fib6_net_exit(struct net *net)
2228 {
2229 unsigned int i;
2230
2231 del_timer_sync(&net->ipv6.ip6_fib_timer);
2232
2233 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) {
2234 struct hlist_head *head = &net->ipv6.fib_table_hash[i];
2235 struct hlist_node *tmp;
2236 struct fib6_table *tb;
2237
2238 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) {
2239 hlist_del(&tb->tb6_hlist);
2240 fib6_free_table(tb);
2241 }
2242 }
2243
2244 kfree(net->ipv6.fib_table_hash);
2245 kfree(net->ipv6.rt6_stats);
2246 fib6_notifier_exit(net);
2247 }
2248
2249 static struct pernet_operations fib6_net_ops = {
2250 .init = fib6_net_init,
2251 .exit = fib6_net_exit,
2252 };
2253
2254 int __init fib6_init(void)
2255 {
2256 int ret = -ENOMEM;
2257
2258 fib6_node_kmem = kmem_cache_create("fib6_nodes",
2259 sizeof(struct fib6_node),
2260 0, SLAB_HWCACHE_ALIGN,
2261 NULL);
2262 if (!fib6_node_kmem)
2263 goto out;
2264
2265 ret = register_pernet_subsys(&fib6_net_ops);
2266 if (ret)
2267 goto out_kmem_cache_create;
2268
2269 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL,
2270 inet6_dump_fib, 0);
2271 if (ret)
2272 goto out_unregister_subsys;
2273
2274 __fib6_flush_trees = fib6_flush_trees;
2275 out:
2276 return ret;
2277
2278 out_unregister_subsys:
2279 unregister_pernet_subsys(&fib6_net_ops);
2280 out_kmem_cache_create:
2281 kmem_cache_destroy(fib6_node_kmem);
2282 goto out;
2283 }
2284
2285 void fib6_gc_cleanup(void)
2286 {
2287 unregister_pernet_subsys(&fib6_net_ops);
2288 kmem_cache_destroy(fib6_node_kmem);
2289 }
2290
2291 #ifdef CONFIG_PROC_FS
2292 static int ipv6_route_seq_show(struct seq_file *seq, void *v)
2293 {
2294 struct fib6_info *rt = v;
2295 struct ipv6_route_iter *iter = seq->private;
2296 const struct net_device *dev;
2297
2298 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen);
2299
2300 #ifdef CONFIG_IPV6_SUBTREES
2301 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen);
2302 #else
2303 seq_puts(seq, "00000000000000000000000000000000 00 ");
2304 #endif
2305 if (rt->fib6_flags & RTF_GATEWAY)
2306 seq_printf(seq, "%pi6", &rt->fib6_nh.nh_gw);
2307 else
2308 seq_puts(seq, "00000000000000000000000000000000");
2309
2310 dev = rt->fib6_nh.nh_dev;
2311 seq_printf(seq, " %08x %08x %08x %08x %8s\n",
2312 rt->fib6_metric, atomic_read(&rt->fib6_ref), 0,
2313 rt->fib6_flags, dev ? dev->name : "");
2314 iter->w.leaf = NULL;
2315 return 0;
2316 }
2317
2318 static int ipv6_route_yield(struct fib6_walker *w)
2319 {
2320 struct ipv6_route_iter *iter = w->args;
2321
2322 if (!iter->skip)
2323 return 1;
2324
2325 do {
2326 iter->w.leaf = rcu_dereference_protected(
2327 iter->w.leaf->fib6_next,
2328 lockdep_is_held(&iter->tbl->tb6_lock));
2329 iter->skip--;
2330 if (!iter->skip && iter->w.leaf)
2331 return 1;
2332 } while (iter->w.leaf);
2333
2334 return 0;
2335 }
2336
2337 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter,
2338 struct net *net)
2339 {
2340 memset(&iter->w, 0, sizeof(iter->w));
2341 iter->w.func = ipv6_route_yield;
2342 iter->w.root = &iter->tbl->tb6_root;
2343 iter->w.state = FWS_INIT;
2344 iter->w.node = iter->w.root;
2345 iter->w.args = iter;
2346 iter->sernum = iter->w.root->fn_sernum;
2347 INIT_LIST_HEAD(&iter->w.lh);
2348 fib6_walker_link(net, &iter->w);
2349 }
2350
2351 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
2352 struct net *net)
2353 {
2354 unsigned int h;
2355 struct hlist_node *node;
2356
2357 if (tbl) {
2358 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1;
2359 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist));
2360 } else {
2361 h = 0;
2362 node = NULL;
2363 }
2364
2365 while (!node && h < FIB6_TABLE_HASHSZ) {
2366 node = rcu_dereference_bh(
2367 hlist_first_rcu(&net->ipv6.fib_table_hash[h++]));
2368 }
2369 return hlist_entry_safe(node, struct fib6_table, tb6_hlist);
2370 }
2371
2372 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter)
2373 {
2374 if (iter->sernum != iter->w.root->fn_sernum) {
2375 iter->sernum = iter->w.root->fn_sernum;
2376 iter->w.state = FWS_INIT;
2377 iter->w.node = iter->w.root;
2378 WARN_ON(iter->w.skip);
2379 iter->w.skip = iter->w.count;
2380 }
2381 }
2382
2383 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2384 {
2385 int r;
2386 struct fib6_info *n;
2387 struct net *net = seq_file_net(seq);
2388 struct ipv6_route_iter *iter = seq->private;
2389
2390 if (!v)
2391 goto iter_table;
2392
2393 n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next);
2394 if (n) {
2395 ++*pos;
2396 return n;
2397 }
2398
2399 iter_table:
2400 ipv6_route_check_sernum(iter);
2401 spin_lock_bh(&iter->tbl->tb6_lock);
2402 r = fib6_walk_continue(&iter->w);
2403 spin_unlock_bh(&iter->tbl->tb6_lock);
2404 if (r > 0) {
2405 if (v)
2406 ++*pos;
2407 return iter->w.leaf;
2408 } else if (r < 0) {
2409 fib6_walker_unlink(net, &iter->w);
2410 return NULL;
2411 }
2412 fib6_walker_unlink(net, &iter->w);
2413
2414 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
2415 if (!iter->tbl)
2416 return NULL;
2417
2418 ipv6_route_seq_setup_walk(iter, net);
2419 goto iter_table;
2420 }
2421
2422 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
2423 __acquires(RCU_BH)
2424 {
2425 struct net *net = seq_file_net(seq);
2426 struct ipv6_route_iter *iter = seq->private;
2427
2428 rcu_read_lock_bh();
2429 iter->tbl = ipv6_route_seq_next_table(NULL, net);
2430 iter->skip = *pos;
2431
2432 if (iter->tbl) {
2433 ipv6_route_seq_setup_walk(iter, net);
2434 return ipv6_route_seq_next(seq, NULL, pos);
2435 } else {
2436 return NULL;
2437 }
2438 }
2439
2440 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter)
2441 {
2442 struct fib6_walker *w = &iter->w;
2443 return w->node && !(w->state == FWS_U && w->node == w->root);
2444 }
2445
2446 static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
2447 __releases(RCU_BH)
2448 {
2449 struct net *net = seq_file_net(seq);
2450 struct ipv6_route_iter *iter = seq->private;
2451
2452 if (ipv6_route_iter_active(iter))
2453 fib6_walker_unlink(net, &iter->w);
2454
2455 rcu_read_unlock_bh();
2456 }
2457
2458 const struct seq_operations ipv6_route_seq_ops = {
2459 .start = ipv6_route_seq_start,
2460 .next = ipv6_route_seq_next,
2461 .stop = ipv6_route_seq_stop,
2462 .show = ipv6_route_seq_show
2463 };
2464 #endif /* CONFIG_PROC_FS */
Linux with added FPC-III support