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1/*
2 * Linux INET6 implementation
3 * Forwarding Information Database
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 *
13 * Changes:
14 * Yuji SEKIYA @USAGI: Support default route on router node;
15 * remove ip6_null_entry from the top of
16 * routing table.
17 * Ville Nuorvala: Fixed routing subtrees.
18 */
19
20#define pr_fmt(fmt) "IPv6: " fmt
21
22#include <linux/errno.h>
23#include <linux/types.h>
24#include <linux/net.h>
25#include <linux/route.h>
26#include <linux/netdevice.h>
27#include <linux/in6.h>
28#include <linux/init.h>
29#include <linux/list.h>
30#include <linux/slab.h>
31
32#include <net/ipv6.h>
33#include <net/ndisc.h>
34#include <net/addrconf.h>
35
36#include <net/ip6_fib.h>
37#include <net/ip6_route.h>
38
39#define RT6_DEBUG 2
40
41#if RT6_DEBUG >= 3
42#define RT6_TRACE(x...) pr_debug(x)
43#else
44#define RT6_TRACE(x...) do { ; } while (0)
45#endif
46
47static struct kmem_cache *fib6_node_kmem __read_mostly;
48
49enum fib_walk_state_t {
50#ifdef CONFIG_IPV6_SUBTREES
51 FWS_S,
52#endif
53 FWS_L,
54 FWS_R,
55 FWS_C,
56 FWS_U
57};
58
59struct fib6_cleaner_t {
60 struct fib6_walker_t w;
61 struct net *net;
62 int (*func)(struct rt6_info *, void *arg);
63 void *arg;
64};
65
66static DEFINE_RWLOCK(fib6_walker_lock);
67
68#ifdef CONFIG_IPV6_SUBTREES
69#define FWS_INIT FWS_S
70#else
71#define FWS_INIT FWS_L
72#endif
73
74static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
75 struct rt6_info *rt);
76static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn);
77static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn);
78static int fib6_walk(struct fib6_walker_t *w);
79static int fib6_walk_continue(struct fib6_walker_t *w);
80
81/*
82 * A routing update causes an increase of the serial number on the
83 * affected subtree. This allows for cached routes to be asynchronously
84 * tested when modifications are made to the destination cache as a
85 * result of redirects, path MTU changes, etc.
86 */
87
88static __u32 rt_sernum;
89
90static void fib6_gc_timer_cb(unsigned long arg);
91
92static LIST_HEAD(fib6_walkers);
93#define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh)
94
95static inline void fib6_walker_link(struct fib6_walker_t *w)
96{
97 write_lock_bh(&fib6_walker_lock);
98 list_add(&w->lh, &fib6_walkers);
99 write_unlock_bh(&fib6_walker_lock);
100}
101
102static inline void fib6_walker_unlink(struct fib6_walker_t *w)
103{
104 write_lock_bh(&fib6_walker_lock);
105 list_del(&w->lh);
106 write_unlock_bh(&fib6_walker_lock);
107}
108static __inline__ u32 fib6_new_sernum(void)
109{
110 u32 n = ++rt_sernum;
111 if ((__s32)n <= 0)
112 rt_sernum = n = 1;
113 return n;
114}
115
116/*
117 * Auxiliary address test functions for the radix tree.
118 *
119 * These assume a 32bit processor (although it will work on
120 * 64bit processors)
121 */
122
123/*
124 * test bit
125 */
126#if defined(__LITTLE_ENDIAN)
127# define BITOP_BE32_SWIZZLE (0x1F & ~7)
128#else
129# define BITOP_BE32_SWIZZLE 0
130#endif
131
132static __inline__ __be32 addr_bit_set(const void *token, int fn_bit)
133{
134 const __be32 *addr = token;
135 /*
136 * Here,
137 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
138 * is optimized version of
139 * htonl(1 << ((~fn_bit)&0x1F))
140 * See include/asm-generic/bitops/le.h.
141 */
142 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
143 addr[fn_bit >> 5];
144}
145
146static __inline__ struct fib6_node *node_alloc(void)
147{
148 struct fib6_node *fn;
149
150 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
151
152 return fn;
153}
154
155static __inline__ void node_free(struct fib6_node *fn)
156{
157 kmem_cache_free(fib6_node_kmem, fn);
158}
159
160static __inline__ void rt6_release(struct rt6_info *rt)
161{
162 if (atomic_dec_and_test(&rt->rt6i_ref))
163 dst_free(&rt->dst);
164}
165
166static void fib6_link_table(struct net *net, struct fib6_table *tb)
167{
168 unsigned int h;
169
170 /*
171 * Initialize table lock at a single place to give lockdep a key,
172 * tables aren't visible prior to being linked to the list.
173 */
174 rwlock_init(&tb->tb6_lock);
175
176 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
177
178 /*
179 * No protection necessary, this is the only list mutatation
180 * operation, tables never disappear once they exist.
181 */
182 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
183}
184
185#ifdef CONFIG_IPV6_MULTIPLE_TABLES
186
187static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
188{
189 struct fib6_table *table;
190
191 table = kzalloc(sizeof(*table), GFP_ATOMIC);
192 if (table) {
193 table->tb6_id = id;
194 table->tb6_root.leaf = net->ipv6.ip6_null_entry;
195 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
196 inet_peer_base_init(&table->tb6_peers);
197 }
198
199 return table;
200}
201
202struct fib6_table *fib6_new_table(struct net *net, u32 id)
203{
204 struct fib6_table *tb;
205
206 if (id == 0)
207 id = RT6_TABLE_MAIN;
208 tb = fib6_get_table(net, id);
209 if (tb)
210 return tb;
211
212 tb = fib6_alloc_table(net, id);
213 if (tb)
214 fib6_link_table(net, tb);
215
216 return tb;
217}
218
219struct fib6_table *fib6_get_table(struct net *net, u32 id)
220{
221 struct fib6_table *tb;
222 struct hlist_head *head;
223 unsigned int h;
224
225 if (id == 0)
226 id = RT6_TABLE_MAIN;
227 h = id & (FIB6_TABLE_HASHSZ - 1);
228 rcu_read_lock();
229 head = &net->ipv6.fib_table_hash[h];
230 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
231 if (tb->tb6_id == id) {
232 rcu_read_unlock();
233 return tb;
234 }
235 }
236 rcu_read_unlock();
237
238 return NULL;
239}
240
241static void __net_init fib6_tables_init(struct net *net)
242{
243 fib6_link_table(net, net->ipv6.fib6_main_tbl);
244 fib6_link_table(net, net->ipv6.fib6_local_tbl);
245}
246#else
247
248struct fib6_table *fib6_new_table(struct net *net, u32 id)
249{
250 return fib6_get_table(net, id);
251}
252
253struct fib6_table *fib6_get_table(struct net *net, u32 id)
254{
255 return net->ipv6.fib6_main_tbl;
256}
257
258struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
259 int flags, pol_lookup_t lookup)
260{
261 return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl6, flags);
262}
263
264static void __net_init fib6_tables_init(struct net *net)
265{
266 fib6_link_table(net, net->ipv6.fib6_main_tbl);
267}
268
269#endif
270
271static int fib6_dump_node(struct fib6_walker_t *w)
272{
273 int res;
274 struct rt6_info *rt;
275
276 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
277 res = rt6_dump_route(rt, w->args);
278 if (res < 0) {
279 /* Frame is full, suspend walking */
280 w->leaf = rt;
281 return 1;
282 }
283 WARN_ON(res == 0);
284 }
285 w->leaf = NULL;
286 return 0;
287}
288
289static void fib6_dump_end(struct netlink_callback *cb)
290{
291 struct fib6_walker_t *w = (void *)cb->args[2];
292
293 if (w) {
294 if (cb->args[4]) {
295 cb->args[4] = 0;
296 fib6_walker_unlink(w);
297 }
298 cb->args[2] = 0;
299 kfree(w);
300 }
301 cb->done = (void *)cb->args[3];
302 cb->args[1] = 3;
303}
304
305static int fib6_dump_done(struct netlink_callback *cb)
306{
307 fib6_dump_end(cb);
308 return cb->done ? cb->done(cb) : 0;
309}
310
311static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
312 struct netlink_callback *cb)
313{
314 struct fib6_walker_t *w;
315 int res;
316
317 w = (void *)cb->args[2];
318 w->root = &table->tb6_root;
319
320 if (cb->args[4] == 0) {
321 w->count = 0;
322 w->skip = 0;
323
324 read_lock_bh(&table->tb6_lock);
325 res = fib6_walk(w);
326 read_unlock_bh(&table->tb6_lock);
327 if (res > 0) {
328 cb->args[4] = 1;
329 cb->args[5] = w->root->fn_sernum;
330 }
331 } else {
332 if (cb->args[5] != w->root->fn_sernum) {
333 /* Begin at the root if the tree changed */
334 cb->args[5] = w->root->fn_sernum;
335 w->state = FWS_INIT;
336 w->node = w->root;
337 w->skip = w->count;
338 } else
339 w->skip = 0;
340
341 read_lock_bh(&table->tb6_lock);
342 res = fib6_walk_continue(w);
343 read_unlock_bh(&table->tb6_lock);
344 if (res <= 0) {
345 fib6_walker_unlink(w);
346 cb->args[4] = 0;
347 }
348 }
349
350 return res;
351}
352
353static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
354{
355 struct net *net = sock_net(skb->sk);
356 unsigned int h, s_h;
357 unsigned int e = 0, s_e;
358 struct rt6_rtnl_dump_arg arg;
359 struct fib6_walker_t *w;
360 struct fib6_table *tb;
361 struct hlist_head *head;
362 int res = 0;
363
364 s_h = cb->args[0];
365 s_e = cb->args[1];
366
367 w = (void *)cb->args[2];
368 if (!w) {
369 /* New dump:
370 *
371 * 1. hook callback destructor.
372 */
373 cb->args[3] = (long)cb->done;
374 cb->done = fib6_dump_done;
375
376 /*
377 * 2. allocate and initialize walker.
378 */
379 w = kzalloc(sizeof(*w), GFP_ATOMIC);
380 if (!w)
381 return -ENOMEM;
382 w->func = fib6_dump_node;
383 cb->args[2] = (long)w;
384 }
385
386 arg.skb = skb;
387 arg.cb = cb;
388 arg.net = net;
389 w->args = &arg;
390
391 rcu_read_lock();
392 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
393 e = 0;
394 head = &net->ipv6.fib_table_hash[h];
395 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
396 if (e < s_e)
397 goto next;
398 res = fib6_dump_table(tb, skb, cb);
399 if (res != 0)
400 goto out;
401next:
402 e++;
403 }
404 }
405out:
406 rcu_read_unlock();
407 cb->args[1] = e;
408 cb->args[0] = h;
409
410 res = res < 0 ? res : skb->len;
411 if (res <= 0)
412 fib6_dump_end(cb);
413 return res;
414}
415
416/*
417 * Routing Table
418 *
419 * return the appropriate node for a routing tree "add" operation
420 * by either creating and inserting or by returning an existing
421 * node.
422 */
423
424static struct fib6_node *fib6_add_1(struct fib6_node *root,
425 struct in6_addr *addr, int plen,
426 int offset, int allow_create,
427 int replace_required)
428{
429 struct fib6_node *fn, *in, *ln;
430 struct fib6_node *pn = NULL;
431 struct rt6key *key;
432 int bit;
433 __be32 dir = 0;
434 __u32 sernum = fib6_new_sernum();
435
436 RT6_TRACE("fib6_add_1\n");
437
438 /* insert node in tree */
439
440 fn = root;
441
442 do {
443 key = (struct rt6key *)((u8 *)fn->leaf + offset);
444
445 /*
446 * Prefix match
447 */
448 if (plen < fn->fn_bit ||
449 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
450 if (!allow_create) {
451 if (replace_required) {
452 pr_warn("Can't replace route, no match found\n");
453 return ERR_PTR(-ENOENT);
454 }
455 pr_warn("NLM_F_CREATE should be set when creating new route\n");
456 }
457 goto insert_above;
458 }
459
460 /*
461 * Exact match ?
462 */
463
464 if (plen == fn->fn_bit) {
465 /* clean up an intermediate node */
466 if (!(fn->fn_flags & RTN_RTINFO)) {
467 rt6_release(fn->leaf);
468 fn->leaf = NULL;
469 }
470
471 fn->fn_sernum = sernum;
472
473 return fn;
474 }
475
476 /*
477 * We have more bits to go
478 */
479
480 /* Try to walk down on tree. */
481 fn->fn_sernum = sernum;
482 dir = addr_bit_set(addr, fn->fn_bit);
483 pn = fn;
484 fn = dir ? fn->right : fn->left;
485 } while (fn);
486
487 if (!allow_create) {
488 /* We should not create new node because
489 * NLM_F_REPLACE was specified without NLM_F_CREATE
490 * I assume it is safe to require NLM_F_CREATE when
491 * REPLACE flag is used! Later we may want to remove the
492 * check for replace_required, because according
493 * to netlink specification, NLM_F_CREATE
494 * MUST be specified if new route is created.
495 * That would keep IPv6 consistent with IPv4
496 */
497 if (replace_required) {
498 pr_warn("Can't replace route, no match found\n");
499 return ERR_PTR(-ENOENT);
500 }
501 pr_warn("NLM_F_CREATE should be set when creating new route\n");
502 }
503 /*
504 * We walked to the bottom of tree.
505 * Create new leaf node without children.
506 */
507
508 ln = node_alloc();
509
510 if (!ln)
511 return ERR_PTR(-ENOMEM);
512 ln->fn_bit = plen;
513
514 ln->parent = pn;
515 ln->fn_sernum = sernum;
516
517 if (dir)
518 pn->right = ln;
519 else
520 pn->left = ln;
521
522 return ln;
523
524
525insert_above:
526 /*
527 * split since we don't have a common prefix anymore or
528 * we have a less significant route.
529 * we've to insert an intermediate node on the list
530 * this new node will point to the one we need to create
531 * and the current
532 */
533
534 pn = fn->parent;
535
536 /* find 1st bit in difference between the 2 addrs.
537
538 See comment in __ipv6_addr_diff: bit may be an invalid value,
539 but if it is >= plen, the value is ignored in any case.
540 */
541
542 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr));
543
544 /*
545 * (intermediate)[in]
546 * / \
547 * (new leaf node)[ln] (old node)[fn]
548 */
549 if (plen > bit) {
550 in = node_alloc();
551 ln = node_alloc();
552
553 if (!in || !ln) {
554 if (in)
555 node_free(in);
556 if (ln)
557 node_free(ln);
558 return ERR_PTR(-ENOMEM);
559 }
560
561 /*
562 * new intermediate node.
563 * RTN_RTINFO will
564 * be off since that an address that chooses one of
565 * the branches would not match less specific routes
566 * in the other branch
567 */
568
569 in->fn_bit = bit;
570
571 in->parent = pn;
572 in->leaf = fn->leaf;
573 atomic_inc(&in->leaf->rt6i_ref);
574
575 in->fn_sernum = sernum;
576
577 /* update parent pointer */
578 if (dir)
579 pn->right = in;
580 else
581 pn->left = in;
582
583 ln->fn_bit = plen;
584
585 ln->parent = in;
586 fn->parent = in;
587
588 ln->fn_sernum = sernum;
589
590 if (addr_bit_set(addr, bit)) {
591 in->right = ln;
592 in->left = fn;
593 } else {
594 in->left = ln;
595 in->right = fn;
596 }
597 } else { /* plen <= bit */
598
599 /*
600 * (new leaf node)[ln]
601 * / \
602 * (old node)[fn] NULL
603 */
604
605 ln = node_alloc();
606
607 if (!ln)
608 return ERR_PTR(-ENOMEM);
609
610 ln->fn_bit = plen;
611
612 ln->parent = pn;
613
614 ln->fn_sernum = sernum;
615
616 if (dir)
617 pn->right = ln;
618 else
619 pn->left = ln;
620
621 if (addr_bit_set(&key->addr, plen))
622 ln->right = fn;
623 else
624 ln->left = fn;
625
626 fn->parent = ln;
627 }
628 return ln;
629}
630
631static inline bool rt6_qualify_for_ecmp(struct rt6_info *rt)
632{
633 return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) ==
634 RTF_GATEWAY;
635}
636
637static int fib6_commit_metrics(struct dst_entry *dst,
638 struct nlattr *mx, int mx_len)
639{
640 struct nlattr *nla;
641 int remaining;
642 u32 *mp;
643
644 if (dst->flags & DST_HOST) {
645 mp = dst_metrics_write_ptr(dst);
646 } else {
647 mp = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL);
648 if (!mp)
649 return -ENOMEM;
650 dst_init_metrics(dst, mp, 0);
651 }
652
653 nla_for_each_attr(nla, mx, mx_len, remaining) {
654 int type = nla_type(nla);
655
656 if (type) {
657 if (type > RTAX_MAX)
658 return -EINVAL;
659
660 mp[type - 1] = nla_get_u32(nla);
661 }
662 }
663 return 0;
664}
665
666/*
667 * Insert routing information in a node.
668 */
669
670static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
671 struct nl_info *info, struct nlattr *mx, int mx_len)
672{
673 struct rt6_info *iter = NULL;
674 struct rt6_info **ins;
675 int replace = (info->nlh &&
676 (info->nlh->nlmsg_flags & NLM_F_REPLACE));
677 int add = (!info->nlh ||
678 (info->nlh->nlmsg_flags & NLM_F_CREATE));
679 int found = 0;
680 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
681 int err;
682
683 ins = &fn->leaf;
684
685 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) {
686 /*
687 * Search for duplicates
688 */
689
690 if (iter->rt6i_metric == rt->rt6i_metric) {
691 /*
692 * Same priority level
693 */
694 if (info->nlh &&
695 (info->nlh->nlmsg_flags & NLM_F_EXCL))
696 return -EEXIST;
697 if (replace) {
698 found++;
699 break;
700 }
701
702 if (iter->dst.dev == rt->dst.dev &&
703 iter->rt6i_idev == rt->rt6i_idev &&
704 ipv6_addr_equal(&iter->rt6i_gateway,
705 &rt->rt6i_gateway)) {
706 if (rt->rt6i_nsiblings)
707 rt->rt6i_nsiblings = 0;
708 if (!(iter->rt6i_flags & RTF_EXPIRES))
709 return -EEXIST;
710 if (!(rt->rt6i_flags & RTF_EXPIRES))
711 rt6_clean_expires(iter);
712 else
713 rt6_set_expires(iter, rt->dst.expires);
714 return -EEXIST;
715 }
716 /* If we have the same destination and the same metric,
717 * but not the same gateway, then the route we try to
718 * add is sibling to this route, increment our counter
719 * of siblings, and later we will add our route to the
720 * list.
721 * Only static routes (which don't have flag
722 * RTF_EXPIRES) are used for ECMPv6.
723 *
724 * To avoid long list, we only had siblings if the
725 * route have a gateway.
726 */
727 if (rt_can_ecmp &&
728 rt6_qualify_for_ecmp(iter))
729 rt->rt6i_nsiblings++;
730 }
731
732 if (iter->rt6i_metric > rt->rt6i_metric)
733 break;
734
735 ins = &iter->dst.rt6_next;
736 }
737
738 /* Reset round-robin state, if necessary */
739 if (ins == &fn->leaf)
740 fn->rr_ptr = NULL;
741
742 /* Link this route to others same route. */
743 if (rt->rt6i_nsiblings) {
744 unsigned int rt6i_nsiblings;
745 struct rt6_info *sibling, *temp_sibling;
746
747 /* Find the first route that have the same metric */
748 sibling = fn->leaf;
749 while (sibling) {
750 if (sibling->rt6i_metric == rt->rt6i_metric &&
751 rt6_qualify_for_ecmp(sibling)) {
752 list_add_tail(&rt->rt6i_siblings,
753 &sibling->rt6i_siblings);
754 break;
755 }
756 sibling = sibling->dst.rt6_next;
757 }
758 /* For each sibling in the list, increment the counter of
759 * siblings. BUG() if counters does not match, list of siblings
760 * is broken!
761 */
762 rt6i_nsiblings = 0;
763 list_for_each_entry_safe(sibling, temp_sibling,
764 &rt->rt6i_siblings, rt6i_siblings) {
765 sibling->rt6i_nsiblings++;
766 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings);
767 rt6i_nsiblings++;
768 }
769 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings);
770 }
771
772 /*
773 * insert node
774 */
775 if (!replace) {
776 if (!add)
777 pr_warn("NLM_F_CREATE should be set when creating new route\n");
778
779add:
780 if (mx) {
781 err = fib6_commit_metrics(&rt->dst, mx, mx_len);
782 if (err)
783 return err;
784 }
785 rt->dst.rt6_next = iter;
786 *ins = rt;
787 rt->rt6i_node = fn;
788 atomic_inc(&rt->rt6i_ref);
789 inet6_rt_notify(RTM_NEWROUTE, rt, info);
790 info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
791
792 if (!(fn->fn_flags & RTN_RTINFO)) {
793 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
794 fn->fn_flags |= RTN_RTINFO;
795 }
796
797 } else {
798 if (!found) {
799 if (add)
800 goto add;
801 pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
802 return -ENOENT;
803 }
804 if (mx) {
805 err = fib6_commit_metrics(&rt->dst, mx, mx_len);
806 if (err)
807 return err;
808 }
809 *ins = rt;
810 rt->rt6i_node = fn;
811 rt->dst.rt6_next = iter->dst.rt6_next;
812 atomic_inc(&rt->rt6i_ref);
813 inet6_rt_notify(RTM_NEWROUTE, rt, info);
814 rt6_release(iter);
815 if (!(fn->fn_flags & RTN_RTINFO)) {
816 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
817 fn->fn_flags |= RTN_RTINFO;
818 }
819 }
820
821 return 0;
822}
823
824static __inline__ void fib6_start_gc(struct net *net, struct rt6_info *rt)
825{
826 if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
827 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE)))
828 mod_timer(&net->ipv6.ip6_fib_timer,
829 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
830}
831
832void fib6_force_start_gc(struct net *net)
833{
834 if (!timer_pending(&net->ipv6.ip6_fib_timer))
835 mod_timer(&net->ipv6.ip6_fib_timer,
836 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
837}
838
839/*
840 * Add routing information to the routing tree.
841 * <destination addr>/<source addr>
842 * with source addr info in sub-trees
843 */
844
845int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info,
846 struct nlattr *mx, int mx_len)
847{
848 struct fib6_node *fn, *pn = NULL;
849 int err = -ENOMEM;
850 int allow_create = 1;
851 int replace_required = 0;
852
853 if (info->nlh) {
854 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
855 allow_create = 0;
856 if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
857 replace_required = 1;
858 }
859 if (!allow_create && !replace_required)
860 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
861
862 fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
863 offsetof(struct rt6_info, rt6i_dst), allow_create,
864 replace_required);
865 if (IS_ERR(fn)) {
866 err = PTR_ERR(fn);
867 fn = NULL;
868 goto out;
869 }
870
871 pn = fn;
872
873#ifdef CONFIG_IPV6_SUBTREES
874 if (rt->rt6i_src.plen) {
875 struct fib6_node *sn;
876
877 if (!fn->subtree) {
878 struct fib6_node *sfn;
879
880 /*
881 * Create subtree.
882 *
883 * fn[main tree]
884 * |
885 * sfn[subtree root]
886 * \
887 * sn[new leaf node]
888 */
889
890 /* Create subtree root node */
891 sfn = node_alloc();
892 if (!sfn)
893 goto st_failure;
894
895 sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
896 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
897 sfn->fn_flags = RTN_ROOT;
898 sfn->fn_sernum = fib6_new_sernum();
899
900 /* Now add the first leaf node to new subtree */
901
902 sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
903 rt->rt6i_src.plen,
904 offsetof(struct rt6_info, rt6i_src),
905 allow_create, replace_required);
906
907 if (IS_ERR(sn)) {
908 /* If it is failed, discard just allocated
909 root, and then (in st_failure) stale node
910 in main tree.
911 */
912 node_free(sfn);
913 err = PTR_ERR(sn);
914 goto st_failure;
915 }
916
917 /* Now link new subtree to main tree */
918 sfn->parent = fn;
919 fn->subtree = sfn;
920 } else {
921 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
922 rt->rt6i_src.plen,
923 offsetof(struct rt6_info, rt6i_src),
924 allow_create, replace_required);
925
926 if (IS_ERR(sn)) {
927 err = PTR_ERR(sn);
928 goto st_failure;
929 }
930 }
931
932 if (!fn->leaf) {
933 fn->leaf = rt;
934 atomic_inc(&rt->rt6i_ref);
935 }
936 fn = sn;
937 }
938#endif
939
940 err = fib6_add_rt2node(fn, rt, info, mx, mx_len);
941 if (!err) {
942 fib6_start_gc(info->nl_net, rt);
943 if (!(rt->rt6i_flags & RTF_CACHE))
944 fib6_prune_clones(info->nl_net, pn, rt);
945 }
946
947out:
948 if (err) {
949#ifdef CONFIG_IPV6_SUBTREES
950 /*
951 * If fib6_add_1 has cleared the old leaf pointer in the
952 * super-tree leaf node we have to find a new one for it.
953 */
954 if (pn != fn && pn->leaf == rt) {
955 pn->leaf = NULL;
956 atomic_dec(&rt->rt6i_ref);
957 }
958 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
959 pn->leaf = fib6_find_prefix(info->nl_net, pn);
960#if RT6_DEBUG >= 2
961 if (!pn->leaf) {
962 WARN_ON(pn->leaf == NULL);
963 pn->leaf = info->nl_net->ipv6.ip6_null_entry;
964 }
965#endif
966 atomic_inc(&pn->leaf->rt6i_ref);
967 }
968#endif
969 dst_free(&rt->dst);
970 }
971 return err;
972
973#ifdef CONFIG_IPV6_SUBTREES
974 /* Subtree creation failed, probably main tree node
975 is orphan. If it is, shoot it.
976 */
977st_failure:
978 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
979 fib6_repair_tree(info->nl_net, fn);
980 dst_free(&rt->dst);
981 return err;
982#endif
983}
984
985/*
986 * Routing tree lookup
987 *
988 */
989
990struct lookup_args {
991 int offset; /* key offset on rt6_info */
992 const struct in6_addr *addr; /* search key */
993};
994
995static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
996 struct lookup_args *args)
997{
998 struct fib6_node *fn;
999 __be32 dir;
1000
1001 if (unlikely(args->offset == 0))
1002 return NULL;
1003
1004 /*
1005 * Descend on a tree
1006 */
1007
1008 fn = root;
1009
1010 for (;;) {
1011 struct fib6_node *next;
1012
1013 dir = addr_bit_set(args->addr, fn->fn_bit);
1014
1015 next = dir ? fn->right : fn->left;
1016
1017 if (next) {
1018 fn = next;
1019 continue;
1020 }
1021 break;
1022 }
1023
1024 while (fn) {
1025 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
1026 struct rt6key *key;
1027
1028 key = (struct rt6key *) ((u8 *) fn->leaf +
1029 args->offset);
1030
1031 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
1032#ifdef CONFIG_IPV6_SUBTREES
1033 if (fn->subtree) {
1034 struct fib6_node *sfn;
1035 sfn = fib6_lookup_1(fn->subtree,
1036 args + 1);
1037 if (!sfn)
1038 goto backtrack;
1039 fn = sfn;
1040 }
1041#endif
1042 if (fn->fn_flags & RTN_RTINFO)
1043 return fn;
1044 }
1045 }
1046#ifdef CONFIG_IPV6_SUBTREES
1047backtrack:
1048#endif
1049 if (fn->fn_flags & RTN_ROOT)
1050 break;
1051
1052 fn = fn->parent;
1053 }
1054
1055 return NULL;
1056}
1057
1058struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr,
1059 const struct in6_addr *saddr)
1060{
1061 struct fib6_node *fn;
1062 struct lookup_args args[] = {
1063 {
1064 .offset = offsetof(struct rt6_info, rt6i_dst),
1065 .addr = daddr,
1066 },
1067#ifdef CONFIG_IPV6_SUBTREES
1068 {
1069 .offset = offsetof(struct rt6_info, rt6i_src),
1070 .addr = saddr,
1071 },
1072#endif
1073 {
1074 .offset = 0, /* sentinel */
1075 }
1076 };
1077
1078 fn = fib6_lookup_1(root, daddr ? args : args + 1);
1079 if (!fn || fn->fn_flags & RTN_TL_ROOT)
1080 fn = root;
1081
1082 return fn;
1083}
1084
1085/*
1086 * Get node with specified destination prefix (and source prefix,
1087 * if subtrees are used)
1088 */
1089
1090
1091static struct fib6_node *fib6_locate_1(struct fib6_node *root,
1092 const struct in6_addr *addr,
1093 int plen, int offset)
1094{
1095 struct fib6_node *fn;
1096
1097 for (fn = root; fn ; ) {
1098 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
1099
1100 /*
1101 * Prefix match
1102 */
1103 if (plen < fn->fn_bit ||
1104 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
1105 return NULL;
1106
1107 if (plen == fn->fn_bit)
1108 return fn;
1109
1110 /*
1111 * We have more bits to go
1112 */
1113 if (addr_bit_set(addr, fn->fn_bit))
1114 fn = fn->right;
1115 else
1116 fn = fn->left;
1117 }
1118 return NULL;
1119}
1120
1121struct fib6_node *fib6_locate(struct fib6_node *root,
1122 const struct in6_addr *daddr, int dst_len,
1123 const struct in6_addr *saddr, int src_len)
1124{
1125 struct fib6_node *fn;
1126
1127 fn = fib6_locate_1(root, daddr, dst_len,
1128 offsetof(struct rt6_info, rt6i_dst));
1129
1130#ifdef CONFIG_IPV6_SUBTREES
1131 if (src_len) {
1132 WARN_ON(saddr == NULL);
1133 if (fn && fn->subtree)
1134 fn = fib6_locate_1(fn->subtree, saddr, src_len,
1135 offsetof(struct rt6_info, rt6i_src));
1136 }
1137#endif
1138
1139 if (fn && fn->fn_flags & RTN_RTINFO)
1140 return fn;
1141
1142 return NULL;
1143}
1144
1145
1146/*
1147 * Deletion
1148 *
1149 */
1150
1151static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
1152{
1153 if (fn->fn_flags & RTN_ROOT)
1154 return net->ipv6.ip6_null_entry;
1155
1156 while (fn) {
1157 if (fn->left)
1158 return fn->left->leaf;
1159 if (fn->right)
1160 return fn->right->leaf;
1161
1162 fn = FIB6_SUBTREE(fn);
1163 }
1164 return NULL;
1165}
1166
1167/*
1168 * Called to trim the tree of intermediate nodes when possible. "fn"
1169 * is the node we want to try and remove.
1170 */
1171
1172static struct fib6_node *fib6_repair_tree(struct net *net,
1173 struct fib6_node *fn)
1174{
1175 int children;
1176 int nstate;
1177 struct fib6_node *child, *pn;
1178 struct fib6_walker_t *w;
1179 int iter = 0;
1180
1181 for (;;) {
1182 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1183 iter++;
1184
1185 WARN_ON(fn->fn_flags & RTN_RTINFO);
1186 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1187 WARN_ON(fn->leaf != NULL);
1188
1189 children = 0;
1190 child = NULL;
1191 if (fn->right)
1192 child = fn->right, children |= 1;
1193 if (fn->left)
1194 child = fn->left, children |= 2;
1195
1196 if (children == 3 || FIB6_SUBTREE(fn)
1197#ifdef CONFIG_IPV6_SUBTREES
1198 /* Subtree root (i.e. fn) may have one child */
1199 || (children && fn->fn_flags & RTN_ROOT)
1200#endif
1201 ) {
1202 fn->leaf = fib6_find_prefix(net, fn);
1203#if RT6_DEBUG >= 2
1204 if (!fn->leaf) {
1205 WARN_ON(!fn->leaf);
1206 fn->leaf = net->ipv6.ip6_null_entry;
1207 }
1208#endif
1209 atomic_inc(&fn->leaf->rt6i_ref);
1210 return fn->parent;
1211 }
1212
1213 pn = fn->parent;
1214#ifdef CONFIG_IPV6_SUBTREES
1215 if (FIB6_SUBTREE(pn) == fn) {
1216 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1217 FIB6_SUBTREE(pn) = NULL;
1218 nstate = FWS_L;
1219 } else {
1220 WARN_ON(fn->fn_flags & RTN_ROOT);
1221#endif
1222 if (pn->right == fn)
1223 pn->right = child;
1224 else if (pn->left == fn)
1225 pn->left = child;
1226#if RT6_DEBUG >= 2
1227 else
1228 WARN_ON(1);
1229#endif
1230 if (child)
1231 child->parent = pn;
1232 nstate = FWS_R;
1233#ifdef CONFIG_IPV6_SUBTREES
1234 }
1235#endif
1236
1237 read_lock(&fib6_walker_lock);
1238 FOR_WALKERS(w) {
1239 if (!child) {
1240 if (w->root == fn) {
1241 w->root = w->node = NULL;
1242 RT6_TRACE("W %p adjusted by delroot 1\n", w);
1243 } else if (w->node == fn) {
1244 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1245 w->node = pn;
1246 w->state = nstate;
1247 }
1248 } else {
1249 if (w->root == fn) {
1250 w->root = child;
1251 RT6_TRACE("W %p adjusted by delroot 2\n", w);
1252 }
1253 if (w->node == fn) {
1254 w->node = child;
1255 if (children&2) {
1256 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1257 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT;
1258 } else {
1259 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1260 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT;
1261 }
1262 }
1263 }
1264 }
1265 read_unlock(&fib6_walker_lock);
1266
1267 node_free(fn);
1268 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
1269 return pn;
1270
1271 rt6_release(pn->leaf);
1272 pn->leaf = NULL;
1273 fn = pn;
1274 }
1275}
1276
1277static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
1278 struct nl_info *info)
1279{
1280 struct fib6_walker_t *w;
1281 struct rt6_info *rt = *rtp;
1282 struct net *net = info->nl_net;
1283
1284 RT6_TRACE("fib6_del_route\n");
1285
1286 /* Unlink it */
1287 *rtp = rt->dst.rt6_next;
1288 rt->rt6i_node = NULL;
1289 net->ipv6.rt6_stats->fib_rt_entries--;
1290 net->ipv6.rt6_stats->fib_discarded_routes++;
1291
1292 /* Reset round-robin state, if necessary */
1293 if (fn->rr_ptr == rt)
1294 fn->rr_ptr = NULL;
1295
1296 /* Remove this entry from other siblings */
1297 if (rt->rt6i_nsiblings) {
1298 struct rt6_info *sibling, *next_sibling;
1299
1300 list_for_each_entry_safe(sibling, next_sibling,
1301 &rt->rt6i_siblings, rt6i_siblings)
1302 sibling->rt6i_nsiblings--;
1303 rt->rt6i_nsiblings = 0;
1304 list_del_init(&rt->rt6i_siblings);
1305 }
1306
1307 /* Adjust walkers */
1308 read_lock(&fib6_walker_lock);
1309 FOR_WALKERS(w) {
1310 if (w->state == FWS_C && w->leaf == rt) {
1311 RT6_TRACE("walker %p adjusted by delroute\n", w);
1312 w->leaf = rt->dst.rt6_next;
1313 if (!w->leaf)
1314 w->state = FWS_U;
1315 }
1316 }
1317 read_unlock(&fib6_walker_lock);
1318
1319 rt->dst.rt6_next = NULL;
1320
1321 /* If it was last route, expunge its radix tree node */
1322 if (!fn->leaf) {
1323 fn->fn_flags &= ~RTN_RTINFO;
1324 net->ipv6.rt6_stats->fib_route_nodes--;
1325 fn = fib6_repair_tree(net, fn);
1326 }
1327
1328 if (atomic_read(&rt->rt6i_ref) != 1) {
1329 /* This route is used as dummy address holder in some split
1330 * nodes. It is not leaked, but it still holds other resources,
1331 * which must be released in time. So, scan ascendant nodes
1332 * and replace dummy references to this route with references
1333 * to still alive ones.
1334 */
1335 while (fn) {
1336 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) {
1337 fn->leaf = fib6_find_prefix(net, fn);
1338 atomic_inc(&fn->leaf->rt6i_ref);
1339 rt6_release(rt);
1340 }
1341 fn = fn->parent;
1342 }
1343 /* No more references are possible at this point. */
1344 BUG_ON(atomic_read(&rt->rt6i_ref) != 1);
1345 }
1346
1347 inet6_rt_notify(RTM_DELROUTE, rt, info);
1348 rt6_release(rt);
1349}
1350
1351int fib6_del(struct rt6_info *rt, struct nl_info *info)
1352{
1353 struct net *net = info->nl_net;
1354 struct fib6_node *fn = rt->rt6i_node;
1355 struct rt6_info **rtp;
1356
1357#if RT6_DEBUG >= 2
1358 if (rt->dst.obsolete > 0) {
1359 WARN_ON(fn != NULL);
1360 return -ENOENT;
1361 }
1362#endif
1363 if (!fn || rt == net->ipv6.ip6_null_entry)
1364 return -ENOENT;
1365
1366 WARN_ON(!(fn->fn_flags & RTN_RTINFO));
1367
1368 if (!(rt->rt6i_flags & RTF_CACHE)) {
1369 struct fib6_node *pn = fn;
1370#ifdef CONFIG_IPV6_SUBTREES
1371 /* clones of this route might be in another subtree */
1372 if (rt->rt6i_src.plen) {
1373 while (!(pn->fn_flags & RTN_ROOT))
1374 pn = pn->parent;
1375 pn = pn->parent;
1376 }
1377#endif
1378 fib6_prune_clones(info->nl_net, pn, rt);
1379 }
1380
1381 /*
1382 * Walk the leaf entries looking for ourself
1383 */
1384
1385 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) {
1386 if (*rtp == rt) {
1387 fib6_del_route(fn, rtp, info);
1388 return 0;
1389 }
1390 }
1391 return -ENOENT;
1392}
1393
1394/*
1395 * Tree traversal function.
1396 *
1397 * Certainly, it is not interrupt safe.
1398 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1399 * It means, that we can modify tree during walking
1400 * and use this function for garbage collection, clone pruning,
1401 * cleaning tree when a device goes down etc. etc.
1402 *
1403 * It guarantees that every node will be traversed,
1404 * and that it will be traversed only once.
1405 *
1406 * Callback function w->func may return:
1407 * 0 -> continue walking.
1408 * positive value -> walking is suspended (used by tree dumps,
1409 * and probably by gc, if it will be split to several slices)
1410 * negative value -> terminate walking.
1411 *
1412 * The function itself returns:
1413 * 0 -> walk is complete.
1414 * >0 -> walk is incomplete (i.e. suspended)
1415 * <0 -> walk is terminated by an error.
1416 */
1417
1418static int fib6_walk_continue(struct fib6_walker_t *w)
1419{
1420 struct fib6_node *fn, *pn;
1421
1422 for (;;) {
1423 fn = w->node;
1424 if (!fn)
1425 return 0;
1426
1427 if (w->prune && fn != w->root &&
1428 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) {
1429 w->state = FWS_C;
1430 w->leaf = fn->leaf;
1431 }
1432 switch (w->state) {
1433#ifdef CONFIG_IPV6_SUBTREES
1434 case FWS_S:
1435 if (FIB6_SUBTREE(fn)) {
1436 w->node = FIB6_SUBTREE(fn);
1437 continue;
1438 }
1439 w->state = FWS_L;
1440#endif
1441 case FWS_L:
1442 if (fn->left) {
1443 w->node = fn->left;
1444 w->state = FWS_INIT;
1445 continue;
1446 }
1447 w->state = FWS_R;
1448 case FWS_R:
1449 if (fn->right) {
1450 w->node = fn->right;
1451 w->state = FWS_INIT;
1452 continue;
1453 }
1454 w->state = FWS_C;
1455 w->leaf = fn->leaf;
1456 case FWS_C:
1457 if (w->leaf && fn->fn_flags & RTN_RTINFO) {
1458 int err;
1459
1460 if (w->skip) {
1461 w->skip--;
1462 goto skip;
1463 }
1464
1465 err = w->func(w);
1466 if (err)
1467 return err;
1468
1469 w->count++;
1470 continue;
1471 }
1472skip:
1473 w->state = FWS_U;
1474 case FWS_U:
1475 if (fn == w->root)
1476 return 0;
1477 pn = fn->parent;
1478 w->node = pn;
1479#ifdef CONFIG_IPV6_SUBTREES
1480 if (FIB6_SUBTREE(pn) == fn) {
1481 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1482 w->state = FWS_L;
1483 continue;
1484 }
1485#endif
1486 if (pn->left == fn) {
1487 w->state = FWS_R;
1488 continue;
1489 }
1490 if (pn->right == fn) {
1491 w->state = FWS_C;
1492 w->leaf = w->node->leaf;
1493 continue;
1494 }
1495#if RT6_DEBUG >= 2
1496 WARN_ON(1);
1497#endif
1498 }
1499 }
1500}
1501
1502static int fib6_walk(struct fib6_walker_t *w)
1503{
1504 int res;
1505
1506 w->state = FWS_INIT;
1507 w->node = w->root;
1508
1509 fib6_walker_link(w);
1510 res = fib6_walk_continue(w);
1511 if (res <= 0)
1512 fib6_walker_unlink(w);
1513 return res;
1514}
1515
1516static int fib6_clean_node(struct fib6_walker_t *w)
1517{
1518 int res;
1519 struct rt6_info *rt;
1520 struct fib6_cleaner_t *c = container_of(w, struct fib6_cleaner_t, w);
1521 struct nl_info info = {
1522 .nl_net = c->net,
1523 };
1524
1525 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
1526 res = c->func(rt, c->arg);
1527 if (res < 0) {
1528 w->leaf = rt;
1529 res = fib6_del(rt, &info);
1530 if (res) {
1531#if RT6_DEBUG >= 2
1532 pr_debug("%s: del failed: rt=%p@%p err=%d\n",
1533 __func__, rt, rt->rt6i_node, res);
1534#endif
1535 continue;
1536 }
1537 return 0;
1538 }
1539 WARN_ON(res != 0);
1540 }
1541 w->leaf = rt;
1542 return 0;
1543}
1544
1545/*
1546 * Convenient frontend to tree walker.
1547 *
1548 * func is called on each route.
1549 * It may return -1 -> delete this route.
1550 * 0 -> continue walking
1551 *
1552 * prune==1 -> only immediate children of node (certainly,
1553 * ignoring pure split nodes) will be scanned.
1554 */
1555
1556static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1557 int (*func)(struct rt6_info *, void *arg),
1558 int prune, void *arg)
1559{
1560 struct fib6_cleaner_t c;
1561
1562 c.w.root = root;
1563 c.w.func = fib6_clean_node;
1564 c.w.prune = prune;
1565 c.w.count = 0;
1566 c.w.skip = 0;
1567 c.func = func;
1568 c.arg = arg;
1569 c.net = net;
1570
1571 fib6_walk(&c.w);
1572}
1573
1574void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
1575 void *arg)
1576{
1577 struct fib6_table *table;
1578 struct hlist_head *head;
1579 unsigned int h;
1580
1581 rcu_read_lock();
1582 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
1583 head = &net->ipv6.fib_table_hash[h];
1584 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
1585 write_lock_bh(&table->tb6_lock);
1586 fib6_clean_tree(net, &table->tb6_root,
1587 func, 0, arg);
1588 write_unlock_bh(&table->tb6_lock);
1589 }
1590 }
1591 rcu_read_unlock();
1592}
1593
1594static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1595{
1596 if (rt->rt6i_flags & RTF_CACHE) {
1597 RT6_TRACE("pruning clone %p\n", rt);
1598 return -1;
1599 }
1600
1601 return 0;
1602}
1603
1604static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
1605 struct rt6_info *rt)
1606{
1607 fib6_clean_tree(net, fn, fib6_prune_clone, 1, rt);
1608}
1609
1610/*
1611 * Garbage collection
1612 */
1613
1614static struct fib6_gc_args
1615{
1616 int timeout;
1617 int more;
1618} gc_args;
1619
1620static int fib6_age(struct rt6_info *rt, void *arg)
1621{
1622 unsigned long now = jiffies;
1623
1624 /*
1625 * check addrconf expiration here.
1626 * Routes are expired even if they are in use.
1627 *
1628 * Also age clones. Note, that clones are aged out
1629 * only if they are not in use now.
1630 */
1631
1632 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) {
1633 if (time_after(now, rt->dst.expires)) {
1634 RT6_TRACE("expiring %p\n", rt);
1635 return -1;
1636 }
1637 gc_args.more++;
1638 } else if (rt->rt6i_flags & RTF_CACHE) {
1639 if (atomic_read(&rt->dst.__refcnt) == 0 &&
1640 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) {
1641 RT6_TRACE("aging clone %p\n", rt);
1642 return -1;
1643 } else if (rt->rt6i_flags & RTF_GATEWAY) {
1644 struct neighbour *neigh;
1645 __u8 neigh_flags = 0;
1646
1647 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway);
1648 if (neigh) {
1649 neigh_flags = neigh->flags;
1650 neigh_release(neigh);
1651 }
1652 if (!(neigh_flags & NTF_ROUTER)) {
1653 RT6_TRACE("purging route %p via non-router but gateway\n",
1654 rt);
1655 return -1;
1656 }
1657 }
1658 gc_args.more++;
1659 }
1660
1661 return 0;
1662}
1663
1664static DEFINE_SPINLOCK(fib6_gc_lock);
1665
1666void fib6_run_gc(unsigned long expires, struct net *net, bool force)
1667{
1668 unsigned long now;
1669
1670 if (force) {
1671 spin_lock_bh(&fib6_gc_lock);
1672 } else if (!spin_trylock_bh(&fib6_gc_lock)) {
1673 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
1674 return;
1675 }
1676 gc_args.timeout = expires ? (int)expires :
1677 net->ipv6.sysctl.ip6_rt_gc_interval;
1678
1679 gc_args.more = icmp6_dst_gc();
1680
1681 fib6_clean_all(net, fib6_age, NULL);
1682 now = jiffies;
1683 net->ipv6.ip6_rt_last_gc = now;
1684
1685 if (gc_args.more)
1686 mod_timer(&net->ipv6.ip6_fib_timer,
1687 round_jiffies(now
1688 + net->ipv6.sysctl.ip6_rt_gc_interval));
1689 else
1690 del_timer(&net->ipv6.ip6_fib_timer);
1691 spin_unlock_bh(&fib6_gc_lock);
1692}
1693
1694static void fib6_gc_timer_cb(unsigned long arg)
1695{
1696 fib6_run_gc(0, (struct net *)arg, true);
1697}
1698
1699static int __net_init fib6_net_init(struct net *net)
1700{
1701 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
1702
1703 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
1704
1705 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
1706 if (!net->ipv6.rt6_stats)
1707 goto out_timer;
1708
1709 /* Avoid false sharing : Use at least a full cache line */
1710 size = max_t(size_t, size, L1_CACHE_BYTES);
1711
1712 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
1713 if (!net->ipv6.fib_table_hash)
1714 goto out_rt6_stats;
1715
1716 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
1717 GFP_KERNEL);
1718 if (!net->ipv6.fib6_main_tbl)
1719 goto out_fib_table_hash;
1720
1721 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
1722 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1723 net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
1724 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1725 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
1726
1727#ifdef CONFIG_IPV6_MULTIPLE_TABLES
1728 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
1729 GFP_KERNEL);
1730 if (!net->ipv6.fib6_local_tbl)
1731 goto out_fib6_main_tbl;
1732 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
1733 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1734 net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
1735 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1736 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
1737#endif
1738 fib6_tables_init(net);
1739
1740 return 0;
1741
1742#ifdef CONFIG_IPV6_MULTIPLE_TABLES
1743out_fib6_main_tbl:
1744 kfree(net->ipv6.fib6_main_tbl);
1745#endif
1746out_fib_table_hash:
1747 kfree(net->ipv6.fib_table_hash);
1748out_rt6_stats:
1749 kfree(net->ipv6.rt6_stats);
1750out_timer:
1751 return -ENOMEM;
1752}
1753
1754static void fib6_net_exit(struct net *net)
1755{
1756 rt6_ifdown(net, NULL);
1757 del_timer_sync(&net->ipv6.ip6_fib_timer);
1758
1759#ifdef CONFIG_IPV6_MULTIPLE_TABLES
1760 inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers);
1761 kfree(net->ipv6.fib6_local_tbl);
1762#endif
1763 inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers);
1764 kfree(net->ipv6.fib6_main_tbl);
1765 kfree(net->ipv6.fib_table_hash);
1766 kfree(net->ipv6.rt6_stats);
1767}
1768
1769static struct pernet_operations fib6_net_ops = {
1770 .init = fib6_net_init,
1771 .exit = fib6_net_exit,
1772};
1773
1774int __init fib6_init(void)
1775{
1776 int ret = -ENOMEM;
1777
1778 fib6_node_kmem = kmem_cache_create("fib6_nodes",
1779 sizeof(struct fib6_node),
1780 0, SLAB_HWCACHE_ALIGN,
1781 NULL);
1782 if (!fib6_node_kmem)
1783 goto out;
1784
1785 ret = register_pernet_subsys(&fib6_net_ops);
1786 if (ret)
1787 goto out_kmem_cache_create;
1788
1789 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib,
1790 NULL);
1791 if (ret)
1792 goto out_unregister_subsys;
1793out:
1794 return ret;
1795
1796out_unregister_subsys:
1797 unregister_pernet_subsys(&fib6_net_ops);
1798out_kmem_cache_create:
1799 kmem_cache_destroy(fib6_node_kmem);
1800 goto out;
1801}
1802
1803void fib6_gc_cleanup(void)
1804{
1805 unregister_pernet_subsys(&fib6_net_ops);
1806 kmem_cache_destroy(fib6_node_kmem);
1807}
1808
1809#ifdef CONFIG_PROC_FS
1810
1811struct ipv6_route_iter {
1812 struct seq_net_private p;
1813 struct fib6_walker_t w;
1814 loff_t skip;
1815 struct fib6_table *tbl;
1816 __u32 sernum;
1817};
1818
1819static int ipv6_route_seq_show(struct seq_file *seq, void *v)
1820{
1821 struct rt6_info *rt = v;
1822 struct ipv6_route_iter *iter = seq->private;
1823
1824 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen);
1825
1826#ifdef CONFIG_IPV6_SUBTREES
1827 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen);
1828#else
1829 seq_puts(seq, "00000000000000000000000000000000 00 ");
1830#endif
1831 if (rt->rt6i_flags & RTF_GATEWAY)
1832 seq_printf(seq, "%pi6", &rt->rt6i_gateway);
1833 else
1834 seq_puts(seq, "00000000000000000000000000000000");
1835
1836 seq_printf(seq, " %08x %08x %08x %08x %8s\n",
1837 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt),
1838 rt->dst.__use, rt->rt6i_flags,
1839 rt->dst.dev ? rt->dst.dev->name : "");
1840 iter->w.leaf = NULL;
1841 return 0;
1842}
1843
1844static int ipv6_route_yield(struct fib6_walker_t *w)
1845{
1846 struct ipv6_route_iter *iter = w->args;
1847
1848 if (!iter->skip)
1849 return 1;
1850
1851 do {
1852 iter->w.leaf = iter->w.leaf->dst.rt6_next;
1853 iter->skip--;
1854 if (!iter->skip && iter->w.leaf)
1855 return 1;
1856 } while (iter->w.leaf);
1857
1858 return 0;
1859}
1860
1861static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter)
1862{
1863 memset(&iter->w, 0, sizeof(iter->w));
1864 iter->w.func = ipv6_route_yield;
1865 iter->w.root = &iter->tbl->tb6_root;
1866 iter->w.state = FWS_INIT;
1867 iter->w.node = iter->w.root;
1868 iter->w.args = iter;
1869 iter->sernum = iter->w.root->fn_sernum;
1870 INIT_LIST_HEAD(&iter->w.lh);
1871 fib6_walker_link(&iter->w);
1872}
1873
1874static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
1875 struct net *net)
1876{
1877 unsigned int h;
1878 struct hlist_node *node;
1879
1880 if (tbl) {
1881 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1;
1882 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist));
1883 } else {
1884 h = 0;
1885 node = NULL;
1886 }
1887
1888 while (!node && h < FIB6_TABLE_HASHSZ) {
1889 node = rcu_dereference_bh(
1890 hlist_first_rcu(&net->ipv6.fib_table_hash[h++]));
1891 }
1892 return hlist_entry_safe(node, struct fib6_table, tb6_hlist);
1893}
1894
1895static void ipv6_route_check_sernum(struct ipv6_route_iter *iter)
1896{
1897 if (iter->sernum != iter->w.root->fn_sernum) {
1898 iter->sernum = iter->w.root->fn_sernum;
1899 iter->w.state = FWS_INIT;
1900 iter->w.node = iter->w.root;
1901 WARN_ON(iter->w.skip);
1902 iter->w.skip = iter->w.count;
1903 }
1904}
1905
1906static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1907{
1908 int r;
1909 struct rt6_info *n;
1910 struct net *net = seq_file_net(seq);
1911 struct ipv6_route_iter *iter = seq->private;
1912
1913 if (!v)
1914 goto iter_table;
1915
1916 n = ((struct rt6_info *)v)->dst.rt6_next;
1917 if (n) {
1918 ++*pos;
1919 return n;
1920 }
1921
1922iter_table:
1923 ipv6_route_check_sernum(iter);
1924 read_lock(&iter->tbl->tb6_lock);
1925 r = fib6_walk_continue(&iter->w);
1926 read_unlock(&iter->tbl->tb6_lock);
1927 if (r > 0) {
1928 if (v)
1929 ++*pos;
1930 return iter->w.leaf;
1931 } else if (r < 0) {
1932 fib6_walker_unlink(&iter->w);
1933 return NULL;
1934 }
1935 fib6_walker_unlink(&iter->w);
1936
1937 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
1938 if (!iter->tbl)
1939 return NULL;
1940
1941 ipv6_route_seq_setup_walk(iter);
1942 goto iter_table;
1943}
1944
1945static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
1946 __acquires(RCU_BH)
1947{
1948 struct net *net = seq_file_net(seq);
1949 struct ipv6_route_iter *iter = seq->private;
1950
1951 rcu_read_lock_bh();
1952 iter->tbl = ipv6_route_seq_next_table(NULL, net);
1953 iter->skip = *pos;
1954
1955 if (iter->tbl) {
1956 ipv6_route_seq_setup_walk(iter);
1957 return ipv6_route_seq_next(seq, NULL, pos);
1958 } else {
1959 return NULL;
1960 }
1961}
1962
1963static bool ipv6_route_iter_active(struct ipv6_route_iter *iter)
1964{
1965 struct fib6_walker_t *w = &iter->w;
1966 return w->node && !(w->state == FWS_U && w->node == w->root);
1967}
1968
1969static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
1970 __releases(RCU_BH)
1971{
1972 struct ipv6_route_iter *iter = seq->private;
1973
1974 if (ipv6_route_iter_active(iter))
1975 fib6_walker_unlink(&iter->w);
1976
1977 rcu_read_unlock_bh();
1978}
1979
1980static const struct seq_operations ipv6_route_seq_ops = {
1981 .start = ipv6_route_seq_start,
1982 .next = ipv6_route_seq_next,
1983 .stop = ipv6_route_seq_stop,
1984 .show = ipv6_route_seq_show
1985};
1986
1987int ipv6_route_open(struct inode *inode, struct file *file)
1988{
1989 return seq_open_net(inode, file, &ipv6_route_seq_ops,
1990 sizeof(struct ipv6_route_iter));
1991}
1992
1993#endif /* CONFIG_PROC_FS */
1/*
2 * Linux INET6 implementation
3 * Forwarding Information Database
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 *
13 * Changes:
14 * Yuji SEKIYA @USAGI: Support default route on router node;
15 * remove ip6_null_entry from the top of
16 * routing table.
17 * Ville Nuorvala: Fixed routing subtrees.
18 */
19
20#define pr_fmt(fmt) "IPv6: " fmt
21
22#include <linux/errno.h>
23#include <linux/types.h>
24#include <linux/net.h>
25#include <linux/route.h>
26#include <linux/netdevice.h>
27#include <linux/in6.h>
28#include <linux/init.h>
29#include <linux/list.h>
30#include <linux/slab.h>
31
32#include <net/ipv6.h>
33#include <net/ndisc.h>
34#include <net/addrconf.h>
35#include <net/lwtunnel.h>
36#include <net/fib_notifier.h>
37
38#include <net/ip6_fib.h>
39#include <net/ip6_route.h>
40
41static struct kmem_cache *fib6_node_kmem __read_mostly;
42
43struct fib6_cleaner {
44 struct fib6_walker w;
45 struct net *net;
46 int (*func)(struct rt6_info *, void *arg);
47 int sernum;
48 void *arg;
49};
50
51#ifdef CONFIG_IPV6_SUBTREES
52#define FWS_INIT FWS_S
53#else
54#define FWS_INIT FWS_L
55#endif
56
57static struct rt6_info *fib6_find_prefix(struct net *net,
58 struct fib6_table *table,
59 struct fib6_node *fn);
60static struct fib6_node *fib6_repair_tree(struct net *net,
61 struct fib6_table *table,
62 struct fib6_node *fn);
63static int fib6_walk(struct net *net, struct fib6_walker *w);
64static int fib6_walk_continue(struct fib6_walker *w);
65
66/*
67 * A routing update causes an increase of the serial number on the
68 * affected subtree. This allows for cached routes to be asynchronously
69 * tested when modifications are made to the destination cache as a
70 * result of redirects, path MTU changes, etc.
71 */
72
73static void fib6_gc_timer_cb(struct timer_list *t);
74
75#define FOR_WALKERS(net, w) \
76 list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh)
77
78static void fib6_walker_link(struct net *net, struct fib6_walker *w)
79{
80 write_lock_bh(&net->ipv6.fib6_walker_lock);
81 list_add(&w->lh, &net->ipv6.fib6_walkers);
82 write_unlock_bh(&net->ipv6.fib6_walker_lock);
83}
84
85static void fib6_walker_unlink(struct net *net, struct fib6_walker *w)
86{
87 write_lock_bh(&net->ipv6.fib6_walker_lock);
88 list_del(&w->lh);
89 write_unlock_bh(&net->ipv6.fib6_walker_lock);
90}
91
92static int fib6_new_sernum(struct net *net)
93{
94 int new, old;
95
96 do {
97 old = atomic_read(&net->ipv6.fib6_sernum);
98 new = old < INT_MAX ? old + 1 : 1;
99 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum,
100 old, new) != old);
101 return new;
102}
103
104enum {
105 FIB6_NO_SERNUM_CHANGE = 0,
106};
107
108void fib6_update_sernum(struct rt6_info *rt)
109{
110 struct net *net = dev_net(rt->dst.dev);
111 struct fib6_node *fn;
112
113 fn = rcu_dereference_protected(rt->rt6i_node,
114 lockdep_is_held(&rt->rt6i_table->tb6_lock));
115 if (fn)
116 fn->fn_sernum = fib6_new_sernum(net);
117}
118
119/*
120 * Auxiliary address test functions for the radix tree.
121 *
122 * These assume a 32bit processor (although it will work on
123 * 64bit processors)
124 */
125
126/*
127 * test bit
128 */
129#if defined(__LITTLE_ENDIAN)
130# define BITOP_BE32_SWIZZLE (0x1F & ~7)
131#else
132# define BITOP_BE32_SWIZZLE 0
133#endif
134
135static __be32 addr_bit_set(const void *token, int fn_bit)
136{
137 const __be32 *addr = token;
138 /*
139 * Here,
140 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
141 * is optimized version of
142 * htonl(1 << ((~fn_bit)&0x1F))
143 * See include/asm-generic/bitops/le.h.
144 */
145 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
146 addr[fn_bit >> 5];
147}
148
149static struct fib6_node *node_alloc(struct net *net)
150{
151 struct fib6_node *fn;
152
153 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
154 if (fn)
155 net->ipv6.rt6_stats->fib_nodes++;
156
157 return fn;
158}
159
160static void node_free_immediate(struct net *net, struct fib6_node *fn)
161{
162 kmem_cache_free(fib6_node_kmem, fn);
163 net->ipv6.rt6_stats->fib_nodes--;
164}
165
166static void node_free_rcu(struct rcu_head *head)
167{
168 struct fib6_node *fn = container_of(head, struct fib6_node, rcu);
169
170 kmem_cache_free(fib6_node_kmem, fn);
171}
172
173static void node_free(struct net *net, struct fib6_node *fn)
174{
175 call_rcu(&fn->rcu, node_free_rcu);
176 net->ipv6.rt6_stats->fib_nodes--;
177}
178
179void rt6_free_pcpu(struct rt6_info *non_pcpu_rt)
180{
181 int cpu;
182
183 if (!non_pcpu_rt->rt6i_pcpu)
184 return;
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(non_pcpu_rt->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}
199EXPORT_SYMBOL_GPL(rt6_free_pcpu);
200
201static void fib6_free_table(struct fib6_table *table)
202{
203 inetpeer_invalidate_tree(&table->tb6_peers);
204 kfree(table);
205}
206
207static void fib6_link_table(struct net *net, struct fib6_table *tb)
208{
209 unsigned int h;
210
211 /*
212 * Initialize table lock at a single place to give lockdep a key,
213 * tables aren't visible prior to being linked to the list.
214 */
215 spin_lock_init(&tb->tb6_lock);
216 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
217
218 /*
219 * No protection necessary, this is the only list mutatation
220 * operation, tables never disappear once they exist.
221 */
222 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
223}
224
225#ifdef CONFIG_IPV6_MULTIPLE_TABLES
226
227static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
228{
229 struct fib6_table *table;
230
231 table = kzalloc(sizeof(*table), GFP_ATOMIC);
232 if (table) {
233 table->tb6_id = id;
234 rcu_assign_pointer(table->tb6_root.leaf,
235 net->ipv6.ip6_null_entry);
236 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
237 inet_peer_base_init(&table->tb6_peers);
238 }
239
240 return table;
241}
242
243struct fib6_table *fib6_new_table(struct net *net, u32 id)
244{
245 struct fib6_table *tb;
246
247 if (id == 0)
248 id = RT6_TABLE_MAIN;
249 tb = fib6_get_table(net, id);
250 if (tb)
251 return tb;
252
253 tb = fib6_alloc_table(net, id);
254 if (tb)
255 fib6_link_table(net, tb);
256
257 return tb;
258}
259EXPORT_SYMBOL_GPL(fib6_new_table);
260
261struct fib6_table *fib6_get_table(struct net *net, u32 id)
262{
263 struct fib6_table *tb;
264 struct hlist_head *head;
265 unsigned int h;
266
267 if (id == 0)
268 id = RT6_TABLE_MAIN;
269 h = id & (FIB6_TABLE_HASHSZ - 1);
270 rcu_read_lock();
271 head = &net->ipv6.fib_table_hash[h];
272 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
273 if (tb->tb6_id == id) {
274 rcu_read_unlock();
275 return tb;
276 }
277 }
278 rcu_read_unlock();
279
280 return NULL;
281}
282EXPORT_SYMBOL_GPL(fib6_get_table);
283
284static void __net_init fib6_tables_init(struct net *net)
285{
286 fib6_link_table(net, net->ipv6.fib6_main_tbl);
287 fib6_link_table(net, net->ipv6.fib6_local_tbl);
288}
289#else
290
291struct fib6_table *fib6_new_table(struct net *net, u32 id)
292{
293 return fib6_get_table(net, id);
294}
295
296struct fib6_table *fib6_get_table(struct net *net, u32 id)
297{
298 return net->ipv6.fib6_main_tbl;
299}
300
301struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
302 const struct sk_buff *skb,
303 int flags, pol_lookup_t lookup)
304{
305 struct rt6_info *rt;
306
307 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
308 if (rt->dst.error == -EAGAIN) {
309 ip6_rt_put(rt);
310 rt = net->ipv6.ip6_null_entry;
311 dst_hold(&rt->dst);
312 }
313
314 return &rt->dst;
315}
316
317static void __net_init fib6_tables_init(struct net *net)
318{
319 fib6_link_table(net, net->ipv6.fib6_main_tbl);
320}
321
322#endif
323
324unsigned int fib6_tables_seq_read(struct net *net)
325{
326 unsigned int h, fib_seq = 0;
327
328 rcu_read_lock();
329 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
330 struct hlist_head *head = &net->ipv6.fib_table_hash[h];
331 struct fib6_table *tb;
332
333 hlist_for_each_entry_rcu(tb, head, tb6_hlist)
334 fib_seq += tb->fib_seq;
335 }
336 rcu_read_unlock();
337
338 return fib_seq;
339}
340
341static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net,
342 enum fib_event_type event_type,
343 struct rt6_info *rt)
344{
345 struct fib6_entry_notifier_info info = {
346 .rt = rt,
347 };
348
349 return call_fib6_notifier(nb, net, event_type, &info.info);
350}
351
352static int call_fib6_entry_notifiers(struct net *net,
353 enum fib_event_type event_type,
354 struct rt6_info *rt,
355 struct netlink_ext_ack *extack)
356{
357 struct fib6_entry_notifier_info info = {
358 .info.extack = extack,
359 .rt = rt,
360 };
361
362 rt->rt6i_table->fib_seq++;
363 return call_fib6_notifiers(net, event_type, &info.info);
364}
365
366struct fib6_dump_arg {
367 struct net *net;
368 struct notifier_block *nb;
369};
370
371static void fib6_rt_dump(struct rt6_info *rt, struct fib6_dump_arg *arg)
372{
373 if (rt == arg->net->ipv6.ip6_null_entry)
374 return;
375 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt);
376}
377
378static int fib6_node_dump(struct fib6_walker *w)
379{
380 struct rt6_info *rt;
381
382 for_each_fib6_walker_rt(w)
383 fib6_rt_dump(rt, w->args);
384 w->leaf = NULL;
385 return 0;
386}
387
388static void fib6_table_dump(struct net *net, struct fib6_table *tb,
389 struct fib6_walker *w)
390{
391 w->root = &tb->tb6_root;
392 spin_lock_bh(&tb->tb6_lock);
393 fib6_walk(net, w);
394 spin_unlock_bh(&tb->tb6_lock);
395}
396
397/* Called with rcu_read_lock() */
398int fib6_tables_dump(struct net *net, struct notifier_block *nb)
399{
400 struct fib6_dump_arg arg;
401 struct fib6_walker *w;
402 unsigned int h;
403
404 w = kzalloc(sizeof(*w), GFP_ATOMIC);
405 if (!w)
406 return -ENOMEM;
407
408 w->func = fib6_node_dump;
409 arg.net = net;
410 arg.nb = nb;
411 w->args = &arg;
412
413 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
414 struct hlist_head *head = &net->ipv6.fib_table_hash[h];
415 struct fib6_table *tb;
416
417 hlist_for_each_entry_rcu(tb, head, tb6_hlist)
418 fib6_table_dump(net, tb, w);
419 }
420
421 kfree(w);
422
423 return 0;
424}
425
426static int fib6_dump_node(struct fib6_walker *w)
427{
428 int res;
429 struct rt6_info *rt;
430
431 for_each_fib6_walker_rt(w) {
432 res = rt6_dump_route(rt, w->args);
433 if (res < 0) {
434 /* Frame is full, suspend walking */
435 w->leaf = rt;
436 return 1;
437 }
438
439 /* Multipath routes are dumped in one route with the
440 * RTA_MULTIPATH attribute. Jump 'rt' to point to the
441 * last sibling of this route (no need to dump the
442 * sibling routes again)
443 */
444 if (rt->rt6i_nsiblings)
445 rt = list_last_entry(&rt->rt6i_siblings,
446 struct rt6_info,
447 rt6i_siblings);
448 }
449 w->leaf = NULL;
450 return 0;
451}
452
453static void fib6_dump_end(struct netlink_callback *cb)
454{
455 struct net *net = sock_net(cb->skb->sk);
456 struct fib6_walker *w = (void *)cb->args[2];
457
458 if (w) {
459 if (cb->args[4]) {
460 cb->args[4] = 0;
461 fib6_walker_unlink(net, w);
462 }
463 cb->args[2] = 0;
464 kfree(w);
465 }
466 cb->done = (void *)cb->args[3];
467 cb->args[1] = 3;
468}
469
470static int fib6_dump_done(struct netlink_callback *cb)
471{
472 fib6_dump_end(cb);
473 return cb->done ? cb->done(cb) : 0;
474}
475
476static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
477 struct netlink_callback *cb)
478{
479 struct net *net = sock_net(skb->sk);
480 struct fib6_walker *w;
481 int res;
482
483 w = (void *)cb->args[2];
484 w->root = &table->tb6_root;
485
486 if (cb->args[4] == 0) {
487 w->count = 0;
488 w->skip = 0;
489
490 spin_lock_bh(&table->tb6_lock);
491 res = fib6_walk(net, w);
492 spin_unlock_bh(&table->tb6_lock);
493 if (res > 0) {
494 cb->args[4] = 1;
495 cb->args[5] = w->root->fn_sernum;
496 }
497 } else {
498 if (cb->args[5] != w->root->fn_sernum) {
499 /* Begin at the root if the tree changed */
500 cb->args[5] = w->root->fn_sernum;
501 w->state = FWS_INIT;
502 w->node = w->root;
503 w->skip = w->count;
504 } else
505 w->skip = 0;
506
507 spin_lock_bh(&table->tb6_lock);
508 res = fib6_walk_continue(w);
509 spin_unlock_bh(&table->tb6_lock);
510 if (res <= 0) {
511 fib6_walker_unlink(net, w);
512 cb->args[4] = 0;
513 }
514 }
515
516 return res;
517}
518
519static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
520{
521 struct net *net = sock_net(skb->sk);
522 unsigned int h, s_h;
523 unsigned int e = 0, s_e;
524 struct rt6_rtnl_dump_arg arg;
525 struct fib6_walker *w;
526 struct fib6_table *tb;
527 struct hlist_head *head;
528 int res = 0;
529
530 s_h = cb->args[0];
531 s_e = cb->args[1];
532
533 w = (void *)cb->args[2];
534 if (!w) {
535 /* New dump:
536 *
537 * 1. hook callback destructor.
538 */
539 cb->args[3] = (long)cb->done;
540 cb->done = fib6_dump_done;
541
542 /*
543 * 2. allocate and initialize walker.
544 */
545 w = kzalloc(sizeof(*w), GFP_ATOMIC);
546 if (!w)
547 return -ENOMEM;
548 w->func = fib6_dump_node;
549 cb->args[2] = (long)w;
550 }
551
552 arg.skb = skb;
553 arg.cb = cb;
554 arg.net = net;
555 w->args = &arg;
556
557 rcu_read_lock();
558 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
559 e = 0;
560 head = &net->ipv6.fib_table_hash[h];
561 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
562 if (e < s_e)
563 goto next;
564 res = fib6_dump_table(tb, skb, cb);
565 if (res != 0)
566 goto out;
567next:
568 e++;
569 }
570 }
571out:
572 rcu_read_unlock();
573 cb->args[1] = e;
574 cb->args[0] = h;
575
576 res = res < 0 ? res : skb->len;
577 if (res <= 0)
578 fib6_dump_end(cb);
579 return res;
580}
581
582/*
583 * Routing Table
584 *
585 * return the appropriate node for a routing tree "add" operation
586 * by either creating and inserting or by returning an existing
587 * node.
588 */
589
590static struct fib6_node *fib6_add_1(struct net *net,
591 struct fib6_table *table,
592 struct fib6_node *root,
593 struct in6_addr *addr, int plen,
594 int offset, int allow_create,
595 int replace_required,
596 struct netlink_ext_ack *extack)
597{
598 struct fib6_node *fn, *in, *ln;
599 struct fib6_node *pn = NULL;
600 struct rt6key *key;
601 int bit;
602 __be32 dir = 0;
603
604 RT6_TRACE("fib6_add_1\n");
605
606 /* insert node in tree */
607
608 fn = root;
609
610 do {
611 struct rt6_info *leaf = rcu_dereference_protected(fn->leaf,
612 lockdep_is_held(&table->tb6_lock));
613 key = (struct rt6key *)((u8 *)leaf + offset);
614
615 /*
616 * Prefix match
617 */
618 if (plen < fn->fn_bit ||
619 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
620 if (!allow_create) {
621 if (replace_required) {
622 NL_SET_ERR_MSG(extack,
623 "Can not replace route - no match found");
624 pr_warn("Can't replace route, no match found\n");
625 return ERR_PTR(-ENOENT);
626 }
627 pr_warn("NLM_F_CREATE should be set when creating new route\n");
628 }
629 goto insert_above;
630 }
631
632 /*
633 * Exact match ?
634 */
635
636 if (plen == fn->fn_bit) {
637 /* clean up an intermediate node */
638 if (!(fn->fn_flags & RTN_RTINFO)) {
639 RCU_INIT_POINTER(fn->leaf, NULL);
640 rt6_release(leaf);
641 /* remove null_entry in the root node */
642 } else if (fn->fn_flags & RTN_TL_ROOT &&
643 rcu_access_pointer(fn->leaf) ==
644 net->ipv6.ip6_null_entry) {
645 RCU_INIT_POINTER(fn->leaf, NULL);
646 }
647
648 return fn;
649 }
650
651 /*
652 * We have more bits to go
653 */
654
655 /* Try to walk down on tree. */
656 dir = addr_bit_set(addr, fn->fn_bit);
657 pn = fn;
658 fn = dir ?
659 rcu_dereference_protected(fn->right,
660 lockdep_is_held(&table->tb6_lock)) :
661 rcu_dereference_protected(fn->left,
662 lockdep_is_held(&table->tb6_lock));
663 } while (fn);
664
665 if (!allow_create) {
666 /* We should not create new node because
667 * NLM_F_REPLACE was specified without NLM_F_CREATE
668 * I assume it is safe to require NLM_F_CREATE when
669 * REPLACE flag is used! Later we may want to remove the
670 * check for replace_required, because according
671 * to netlink specification, NLM_F_CREATE
672 * MUST be specified if new route is created.
673 * That would keep IPv6 consistent with IPv4
674 */
675 if (replace_required) {
676 NL_SET_ERR_MSG(extack,
677 "Can not replace route - no match found");
678 pr_warn("Can't replace route, no match found\n");
679 return ERR_PTR(-ENOENT);
680 }
681 pr_warn("NLM_F_CREATE should be set when creating new route\n");
682 }
683 /*
684 * We walked to the bottom of tree.
685 * Create new leaf node without children.
686 */
687
688 ln = node_alloc(net);
689
690 if (!ln)
691 return ERR_PTR(-ENOMEM);
692 ln->fn_bit = plen;
693 RCU_INIT_POINTER(ln->parent, pn);
694
695 if (dir)
696 rcu_assign_pointer(pn->right, ln);
697 else
698 rcu_assign_pointer(pn->left, ln);
699
700 return ln;
701
702
703insert_above:
704 /*
705 * split since we don't have a common prefix anymore or
706 * we have a less significant route.
707 * we've to insert an intermediate node on the list
708 * this new node will point to the one we need to create
709 * and the current
710 */
711
712 pn = rcu_dereference_protected(fn->parent,
713 lockdep_is_held(&table->tb6_lock));
714
715 /* find 1st bit in difference between the 2 addrs.
716
717 See comment in __ipv6_addr_diff: bit may be an invalid value,
718 but if it is >= plen, the value is ignored in any case.
719 */
720
721 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr));
722
723 /*
724 * (intermediate)[in]
725 * / \
726 * (new leaf node)[ln] (old node)[fn]
727 */
728 if (plen > bit) {
729 in = node_alloc(net);
730 ln = node_alloc(net);
731
732 if (!in || !ln) {
733 if (in)
734 node_free_immediate(net, in);
735 if (ln)
736 node_free_immediate(net, ln);
737 return ERR_PTR(-ENOMEM);
738 }
739
740 /*
741 * new intermediate node.
742 * RTN_RTINFO will
743 * be off since that an address that chooses one of
744 * the branches would not match less specific routes
745 * in the other branch
746 */
747
748 in->fn_bit = bit;
749
750 RCU_INIT_POINTER(in->parent, pn);
751 in->leaf = fn->leaf;
752 atomic_inc(&rcu_dereference_protected(in->leaf,
753 lockdep_is_held(&table->tb6_lock))->rt6i_ref);
754
755 /* update parent pointer */
756 if (dir)
757 rcu_assign_pointer(pn->right, in);
758 else
759 rcu_assign_pointer(pn->left, in);
760
761 ln->fn_bit = plen;
762
763 RCU_INIT_POINTER(ln->parent, in);
764 rcu_assign_pointer(fn->parent, in);
765
766 if (addr_bit_set(addr, bit)) {
767 rcu_assign_pointer(in->right, ln);
768 rcu_assign_pointer(in->left, fn);
769 } else {
770 rcu_assign_pointer(in->left, ln);
771 rcu_assign_pointer(in->right, fn);
772 }
773 } else { /* plen <= bit */
774
775 /*
776 * (new leaf node)[ln]
777 * / \
778 * (old node)[fn] NULL
779 */
780
781 ln = node_alloc(net);
782
783 if (!ln)
784 return ERR_PTR(-ENOMEM);
785
786 ln->fn_bit = plen;
787
788 RCU_INIT_POINTER(ln->parent, pn);
789
790 if (addr_bit_set(&key->addr, plen))
791 RCU_INIT_POINTER(ln->right, fn);
792 else
793 RCU_INIT_POINTER(ln->left, fn);
794
795 rcu_assign_pointer(fn->parent, ln);
796
797 if (dir)
798 rcu_assign_pointer(pn->right, ln);
799 else
800 rcu_assign_pointer(pn->left, ln);
801 }
802 return ln;
803}
804
805static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc)
806{
807 int i;
808
809 for (i = 0; i < RTAX_MAX; i++) {
810 if (test_bit(i, mxc->mx_valid))
811 mp[i] = mxc->mx[i];
812 }
813}
814
815static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc)
816{
817 if (!mxc->mx)
818 return 0;
819
820 if (dst->flags & DST_HOST) {
821 u32 *mp = dst_metrics_write_ptr(dst);
822
823 if (unlikely(!mp))
824 return -ENOMEM;
825
826 fib6_copy_metrics(mp, mxc);
827 } else {
828 dst_init_metrics(dst, mxc->mx, false);
829
830 /* We've stolen mx now. */
831 mxc->mx = NULL;
832 }
833
834 return 0;
835}
836
837static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn,
838 struct net *net)
839{
840 struct fib6_table *table = rt->rt6i_table;
841
842 if (atomic_read(&rt->rt6i_ref) != 1) {
843 /* This route is used as dummy address holder in some split
844 * nodes. It is not leaked, but it still holds other resources,
845 * which must be released in time. So, scan ascendant nodes
846 * and replace dummy references to this route with references
847 * to still alive ones.
848 */
849 while (fn) {
850 struct rt6_info *leaf = rcu_dereference_protected(fn->leaf,
851 lockdep_is_held(&table->tb6_lock));
852 struct rt6_info *new_leaf;
853 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) {
854 new_leaf = fib6_find_prefix(net, table, fn);
855 atomic_inc(&new_leaf->rt6i_ref);
856 rcu_assign_pointer(fn->leaf, new_leaf);
857 rt6_release(rt);
858 }
859 fn = rcu_dereference_protected(fn->parent,
860 lockdep_is_held(&table->tb6_lock));
861 }
862 }
863}
864
865/*
866 * Insert routing information in a node.
867 */
868
869static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
870 struct nl_info *info, struct mx6_config *mxc,
871 struct netlink_ext_ack *extack)
872{
873 struct rt6_info *leaf = rcu_dereference_protected(fn->leaf,
874 lockdep_is_held(&rt->rt6i_table->tb6_lock));
875 struct rt6_info *iter = NULL;
876 struct rt6_info __rcu **ins;
877 struct rt6_info __rcu **fallback_ins = NULL;
878 int replace = (info->nlh &&
879 (info->nlh->nlmsg_flags & NLM_F_REPLACE));
880 int add = (!info->nlh ||
881 (info->nlh->nlmsg_flags & NLM_F_CREATE));
882 int found = 0;
883 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
884 u16 nlflags = NLM_F_EXCL;
885 int err;
886
887 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND))
888 nlflags |= NLM_F_APPEND;
889
890 ins = &fn->leaf;
891
892 for (iter = leaf; iter;
893 iter = rcu_dereference_protected(iter->rt6_next,
894 lockdep_is_held(&rt->rt6i_table->tb6_lock))) {
895 /*
896 * Search for duplicates
897 */
898
899 if (iter->rt6i_metric == rt->rt6i_metric) {
900 /*
901 * Same priority level
902 */
903 if (info->nlh &&
904 (info->nlh->nlmsg_flags & NLM_F_EXCL))
905 return -EEXIST;
906
907 nlflags &= ~NLM_F_EXCL;
908 if (replace) {
909 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) {
910 found++;
911 break;
912 }
913 if (rt_can_ecmp)
914 fallback_ins = fallback_ins ?: ins;
915 goto next_iter;
916 }
917
918 if (rt6_duplicate_nexthop(iter, rt)) {
919 if (rt->rt6i_nsiblings)
920 rt->rt6i_nsiblings = 0;
921 if (!(iter->rt6i_flags & RTF_EXPIRES))
922 return -EEXIST;
923 if (!(rt->rt6i_flags & RTF_EXPIRES))
924 rt6_clean_expires(iter);
925 else
926 rt6_set_expires(iter, rt->dst.expires);
927 iter->rt6i_pmtu = rt->rt6i_pmtu;
928 return -EEXIST;
929 }
930 /* If we have the same destination and the same metric,
931 * but not the same gateway, then the route we try to
932 * add is sibling to this route, increment our counter
933 * of siblings, and later we will add our route to the
934 * list.
935 * Only static routes (which don't have flag
936 * RTF_EXPIRES) are used for ECMPv6.
937 *
938 * To avoid long list, we only had siblings if the
939 * route have a gateway.
940 */
941 if (rt_can_ecmp &&
942 rt6_qualify_for_ecmp(iter))
943 rt->rt6i_nsiblings++;
944 }
945
946 if (iter->rt6i_metric > rt->rt6i_metric)
947 break;
948
949next_iter:
950 ins = &iter->rt6_next;
951 }
952
953 if (fallback_ins && !found) {
954 /* No ECMP-able route found, replace first non-ECMP one */
955 ins = fallback_ins;
956 iter = rcu_dereference_protected(*ins,
957 lockdep_is_held(&rt->rt6i_table->tb6_lock));
958 found++;
959 }
960
961 /* Reset round-robin state, if necessary */
962 if (ins == &fn->leaf)
963 fn->rr_ptr = NULL;
964
965 /* Link this route to others same route. */
966 if (rt->rt6i_nsiblings) {
967 unsigned int rt6i_nsiblings;
968 struct rt6_info *sibling, *temp_sibling;
969
970 /* Find the first route that have the same metric */
971 sibling = leaf;
972 while (sibling) {
973 if (sibling->rt6i_metric == rt->rt6i_metric &&
974 rt6_qualify_for_ecmp(sibling)) {
975 list_add_tail(&rt->rt6i_siblings,
976 &sibling->rt6i_siblings);
977 break;
978 }
979 sibling = rcu_dereference_protected(sibling->rt6_next,
980 lockdep_is_held(&rt->rt6i_table->tb6_lock));
981 }
982 /* For each sibling in the list, increment the counter of
983 * siblings. BUG() if counters does not match, list of siblings
984 * is broken!
985 */
986 rt6i_nsiblings = 0;
987 list_for_each_entry_safe(sibling, temp_sibling,
988 &rt->rt6i_siblings, rt6i_siblings) {
989 sibling->rt6i_nsiblings++;
990 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings);
991 rt6i_nsiblings++;
992 }
993 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings);
994 rt6_multipath_rebalance(temp_sibling);
995 }
996
997 /*
998 * insert node
999 */
1000 if (!replace) {
1001 if (!add)
1002 pr_warn("NLM_F_CREATE should be set when creating new route\n");
1003
1004add:
1005 nlflags |= NLM_F_CREATE;
1006 err = fib6_commit_metrics(&rt->dst, mxc);
1007 if (err)
1008 return err;
1009
1010 err = call_fib6_entry_notifiers(info->nl_net,
1011 FIB_EVENT_ENTRY_ADD,
1012 rt, extack);
1013 if (err)
1014 return err;
1015
1016 rcu_assign_pointer(rt->rt6_next, iter);
1017 atomic_inc(&rt->rt6i_ref);
1018 rcu_assign_pointer(rt->rt6i_node, fn);
1019 rcu_assign_pointer(*ins, rt);
1020 if (!info->skip_notify)
1021 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
1022 info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
1023
1024 if (!(fn->fn_flags & RTN_RTINFO)) {
1025 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
1026 fn->fn_flags |= RTN_RTINFO;
1027 }
1028
1029 } else {
1030 int nsiblings;
1031
1032 if (!found) {
1033 if (add)
1034 goto add;
1035 pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
1036 return -ENOENT;
1037 }
1038
1039 err = fib6_commit_metrics(&rt->dst, mxc);
1040 if (err)
1041 return err;
1042
1043 err = call_fib6_entry_notifiers(info->nl_net,
1044 FIB_EVENT_ENTRY_REPLACE,
1045 rt, extack);
1046 if (err)
1047 return err;
1048
1049 atomic_inc(&rt->rt6i_ref);
1050 rcu_assign_pointer(rt->rt6i_node, fn);
1051 rt->rt6_next = iter->rt6_next;
1052 rcu_assign_pointer(*ins, rt);
1053 if (!info->skip_notify)
1054 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE);
1055 if (!(fn->fn_flags & RTN_RTINFO)) {
1056 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
1057 fn->fn_flags |= RTN_RTINFO;
1058 }
1059 nsiblings = iter->rt6i_nsiblings;
1060 iter->rt6i_node = NULL;
1061 fib6_purge_rt(iter, fn, info->nl_net);
1062 if (rcu_access_pointer(fn->rr_ptr) == iter)
1063 fn->rr_ptr = NULL;
1064 rt6_release(iter);
1065
1066 if (nsiblings) {
1067 /* Replacing an ECMP route, remove all siblings */
1068 ins = &rt->rt6_next;
1069 iter = rcu_dereference_protected(*ins,
1070 lockdep_is_held(&rt->rt6i_table->tb6_lock));
1071 while (iter) {
1072 if (iter->rt6i_metric > rt->rt6i_metric)
1073 break;
1074 if (rt6_qualify_for_ecmp(iter)) {
1075 *ins = iter->rt6_next;
1076 iter->rt6i_node = NULL;
1077 fib6_purge_rt(iter, fn, info->nl_net);
1078 if (rcu_access_pointer(fn->rr_ptr) == iter)
1079 fn->rr_ptr = NULL;
1080 rt6_release(iter);
1081 nsiblings--;
1082 info->nl_net->ipv6.rt6_stats->fib_rt_entries--;
1083 } else {
1084 ins = &iter->rt6_next;
1085 }
1086 iter = rcu_dereference_protected(*ins,
1087 lockdep_is_held(&rt->rt6i_table->tb6_lock));
1088 }
1089 WARN_ON(nsiblings != 0);
1090 }
1091 }
1092
1093 return 0;
1094}
1095
1096static void fib6_start_gc(struct net *net, struct rt6_info *rt)
1097{
1098 if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
1099 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE)))
1100 mod_timer(&net->ipv6.ip6_fib_timer,
1101 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
1102}
1103
1104void fib6_force_start_gc(struct net *net)
1105{
1106 if (!timer_pending(&net->ipv6.ip6_fib_timer))
1107 mod_timer(&net->ipv6.ip6_fib_timer,
1108 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
1109}
1110
1111static void __fib6_update_sernum_upto_root(struct rt6_info *rt,
1112 int sernum)
1113{
1114 struct fib6_node *fn = rcu_dereference_protected(rt->rt6i_node,
1115 lockdep_is_held(&rt->rt6i_table->tb6_lock));
1116
1117 /* paired with smp_rmb() in rt6_get_cookie_safe() */
1118 smp_wmb();
1119 while (fn) {
1120 fn->fn_sernum = sernum;
1121 fn = rcu_dereference_protected(fn->parent,
1122 lockdep_is_held(&rt->rt6i_table->tb6_lock));
1123 }
1124}
1125
1126void fib6_update_sernum_upto_root(struct net *net, struct rt6_info *rt)
1127{
1128 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net));
1129}
1130
1131/*
1132 * Add routing information to the routing tree.
1133 * <destination addr>/<source addr>
1134 * with source addr info in sub-trees
1135 * Need to own table->tb6_lock
1136 */
1137
1138int fib6_add(struct fib6_node *root, struct rt6_info *rt,
1139 struct nl_info *info, struct mx6_config *mxc,
1140 struct netlink_ext_ack *extack)
1141{
1142 struct fib6_table *table = rt->rt6i_table;
1143 struct fib6_node *fn, *pn = NULL;
1144 int err = -ENOMEM;
1145 int allow_create = 1;
1146 int replace_required = 0;
1147 int sernum = fib6_new_sernum(info->nl_net);
1148
1149 if (WARN_ON_ONCE(!atomic_read(&rt->dst.__refcnt)))
1150 return -EINVAL;
1151 if (WARN_ON_ONCE(rt->rt6i_flags & RTF_CACHE))
1152 return -EINVAL;
1153
1154 if (info->nlh) {
1155 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
1156 allow_create = 0;
1157 if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
1158 replace_required = 1;
1159 }
1160 if (!allow_create && !replace_required)
1161 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
1162
1163 fn = fib6_add_1(info->nl_net, table, root,
1164 &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
1165 offsetof(struct rt6_info, rt6i_dst), allow_create,
1166 replace_required, extack);
1167 if (IS_ERR(fn)) {
1168 err = PTR_ERR(fn);
1169 fn = NULL;
1170 goto out;
1171 }
1172
1173 pn = fn;
1174
1175#ifdef CONFIG_IPV6_SUBTREES
1176 if (rt->rt6i_src.plen) {
1177 struct fib6_node *sn;
1178
1179 if (!rcu_access_pointer(fn->subtree)) {
1180 struct fib6_node *sfn;
1181
1182 /*
1183 * Create subtree.
1184 *
1185 * fn[main tree]
1186 * |
1187 * sfn[subtree root]
1188 * \
1189 * sn[new leaf node]
1190 */
1191
1192 /* Create subtree root node */
1193 sfn = node_alloc(info->nl_net);
1194 if (!sfn)
1195 goto failure;
1196
1197 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
1198 rcu_assign_pointer(sfn->leaf,
1199 info->nl_net->ipv6.ip6_null_entry);
1200 sfn->fn_flags = RTN_ROOT;
1201
1202 /* Now add the first leaf node to new subtree */
1203
1204 sn = fib6_add_1(info->nl_net, table, sfn,
1205 &rt->rt6i_src.addr, rt->rt6i_src.plen,
1206 offsetof(struct rt6_info, rt6i_src),
1207 allow_create, replace_required, extack);
1208
1209 if (IS_ERR(sn)) {
1210 /* If it is failed, discard just allocated
1211 root, and then (in failure) stale node
1212 in main tree.
1213 */
1214 node_free_immediate(info->nl_net, sfn);
1215 err = PTR_ERR(sn);
1216 goto failure;
1217 }
1218
1219 /* Now link new subtree to main tree */
1220 rcu_assign_pointer(sfn->parent, fn);
1221 rcu_assign_pointer(fn->subtree, sfn);
1222 } else {
1223 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn),
1224 &rt->rt6i_src.addr, rt->rt6i_src.plen,
1225 offsetof(struct rt6_info, rt6i_src),
1226 allow_create, replace_required, extack);
1227
1228 if (IS_ERR(sn)) {
1229 err = PTR_ERR(sn);
1230 goto failure;
1231 }
1232 }
1233
1234 if (!rcu_access_pointer(fn->leaf)) {
1235 if (fn->fn_flags & RTN_TL_ROOT) {
1236 /* put back null_entry for root node */
1237 rcu_assign_pointer(fn->leaf,
1238 info->nl_net->ipv6.ip6_null_entry);
1239 } else {
1240 atomic_inc(&rt->rt6i_ref);
1241 rcu_assign_pointer(fn->leaf, rt);
1242 }
1243 }
1244 fn = sn;
1245 }
1246#endif
1247
1248 err = fib6_add_rt2node(fn, rt, info, mxc, extack);
1249 if (!err) {
1250 __fib6_update_sernum_upto_root(rt, sernum);
1251 fib6_start_gc(info->nl_net, rt);
1252 }
1253
1254out:
1255 if (err) {
1256#ifdef CONFIG_IPV6_SUBTREES
1257 /*
1258 * If fib6_add_1 has cleared the old leaf pointer in the
1259 * super-tree leaf node we have to find a new one for it.
1260 */
1261 if (pn != fn) {
1262 struct rt6_info *pn_leaf =
1263 rcu_dereference_protected(pn->leaf,
1264 lockdep_is_held(&table->tb6_lock));
1265 if (pn_leaf == rt) {
1266 pn_leaf = NULL;
1267 RCU_INIT_POINTER(pn->leaf, NULL);
1268 atomic_dec(&rt->rt6i_ref);
1269 }
1270 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) {
1271 pn_leaf = fib6_find_prefix(info->nl_net, table,
1272 pn);
1273#if RT6_DEBUG >= 2
1274 if (!pn_leaf) {
1275 WARN_ON(!pn_leaf);
1276 pn_leaf =
1277 info->nl_net->ipv6.ip6_null_entry;
1278 }
1279#endif
1280 atomic_inc(&pn_leaf->rt6i_ref);
1281 rcu_assign_pointer(pn->leaf, pn_leaf);
1282 }
1283 }
1284#endif
1285 goto failure;
1286 }
1287 return err;
1288
1289failure:
1290 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if:
1291 * 1. fn is an intermediate node and we failed to add the new
1292 * route to it in both subtree creation failure and fib6_add_rt2node()
1293 * failure case.
1294 * 2. fn is the root node in the table and we fail to add the first
1295 * default route to it.
1296 */
1297 if (fn &&
1298 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) ||
1299 (fn->fn_flags & RTN_TL_ROOT &&
1300 !rcu_access_pointer(fn->leaf))))
1301 fib6_repair_tree(info->nl_net, table, fn);
1302 /* Always release dst as dst->__refcnt is guaranteed
1303 * to be taken before entering this function
1304 */
1305 dst_release_immediate(&rt->dst);
1306 return err;
1307}
1308
1309/*
1310 * Routing tree lookup
1311 *
1312 */
1313
1314struct lookup_args {
1315 int offset; /* key offset on rt6_info */
1316 const struct in6_addr *addr; /* search key */
1317};
1318
1319static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
1320 struct lookup_args *args)
1321{
1322 struct fib6_node *fn;
1323 __be32 dir;
1324
1325 if (unlikely(args->offset == 0))
1326 return NULL;
1327
1328 /*
1329 * Descend on a tree
1330 */
1331
1332 fn = root;
1333
1334 for (;;) {
1335 struct fib6_node *next;
1336
1337 dir = addr_bit_set(args->addr, fn->fn_bit);
1338
1339 next = dir ? rcu_dereference(fn->right) :
1340 rcu_dereference(fn->left);
1341
1342 if (next) {
1343 fn = next;
1344 continue;
1345 }
1346 break;
1347 }
1348
1349 while (fn) {
1350 struct fib6_node *subtree = FIB6_SUBTREE(fn);
1351
1352 if (subtree || fn->fn_flags & RTN_RTINFO) {
1353 struct rt6_info *leaf = rcu_dereference(fn->leaf);
1354 struct rt6key *key;
1355
1356 if (!leaf)
1357 goto backtrack;
1358
1359 key = (struct rt6key *) ((u8 *)leaf + args->offset);
1360
1361 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
1362#ifdef CONFIG_IPV6_SUBTREES
1363 if (subtree) {
1364 struct fib6_node *sfn;
1365 sfn = fib6_lookup_1(subtree, args + 1);
1366 if (!sfn)
1367 goto backtrack;
1368 fn = sfn;
1369 }
1370#endif
1371 if (fn->fn_flags & RTN_RTINFO)
1372 return fn;
1373 }
1374 }
1375backtrack:
1376 if (fn->fn_flags & RTN_ROOT)
1377 break;
1378
1379 fn = rcu_dereference(fn->parent);
1380 }
1381
1382 return NULL;
1383}
1384
1385/* called with rcu_read_lock() held
1386 */
1387struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr,
1388 const struct in6_addr *saddr)
1389{
1390 struct fib6_node *fn;
1391 struct lookup_args args[] = {
1392 {
1393 .offset = offsetof(struct rt6_info, rt6i_dst),
1394 .addr = daddr,
1395 },
1396#ifdef CONFIG_IPV6_SUBTREES
1397 {
1398 .offset = offsetof(struct rt6_info, rt6i_src),
1399 .addr = saddr,
1400 },
1401#endif
1402 {
1403 .offset = 0, /* sentinel */
1404 }
1405 };
1406
1407 fn = fib6_lookup_1(root, daddr ? args : args + 1);
1408 if (!fn || fn->fn_flags & RTN_TL_ROOT)
1409 fn = root;
1410
1411 return fn;
1412}
1413
1414/*
1415 * Get node with specified destination prefix (and source prefix,
1416 * if subtrees are used)
1417 * exact_match == true means we try to find fn with exact match of
1418 * the passed in prefix addr
1419 * exact_match == false means we try to find fn with longest prefix
1420 * match of the passed in prefix addr. This is useful for finding fn
1421 * for cached route as it will be stored in the exception table under
1422 * the node with longest prefix length.
1423 */
1424
1425
1426static struct fib6_node *fib6_locate_1(struct fib6_node *root,
1427 const struct in6_addr *addr,
1428 int plen, int offset,
1429 bool exact_match)
1430{
1431 struct fib6_node *fn, *prev = NULL;
1432
1433 for (fn = root; fn ; ) {
1434 struct rt6_info *leaf = rcu_dereference(fn->leaf);
1435 struct rt6key *key;
1436
1437 /* This node is being deleted */
1438 if (!leaf) {
1439 if (plen <= fn->fn_bit)
1440 goto out;
1441 else
1442 goto next;
1443 }
1444
1445 key = (struct rt6key *)((u8 *)leaf + offset);
1446
1447 /*
1448 * Prefix match
1449 */
1450 if (plen < fn->fn_bit ||
1451 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
1452 goto out;
1453
1454 if (plen == fn->fn_bit)
1455 return fn;
1456
1457 prev = fn;
1458
1459next:
1460 /*
1461 * We have more bits to go
1462 */
1463 if (addr_bit_set(addr, fn->fn_bit))
1464 fn = rcu_dereference(fn->right);
1465 else
1466 fn = rcu_dereference(fn->left);
1467 }
1468out:
1469 if (exact_match)
1470 return NULL;
1471 else
1472 return prev;
1473}
1474
1475struct fib6_node *fib6_locate(struct fib6_node *root,
1476 const struct in6_addr *daddr, int dst_len,
1477 const struct in6_addr *saddr, int src_len,
1478 bool exact_match)
1479{
1480 struct fib6_node *fn;
1481
1482 fn = fib6_locate_1(root, daddr, dst_len,
1483 offsetof(struct rt6_info, rt6i_dst),
1484 exact_match);
1485
1486#ifdef CONFIG_IPV6_SUBTREES
1487 if (src_len) {
1488 WARN_ON(saddr == NULL);
1489 if (fn) {
1490 struct fib6_node *subtree = FIB6_SUBTREE(fn);
1491
1492 if (subtree) {
1493 fn = fib6_locate_1(subtree, saddr, src_len,
1494 offsetof(struct rt6_info, rt6i_src),
1495 exact_match);
1496 }
1497 }
1498 }
1499#endif
1500
1501 if (fn && fn->fn_flags & RTN_RTINFO)
1502 return fn;
1503
1504 return NULL;
1505}
1506
1507
1508/*
1509 * Deletion
1510 *
1511 */
1512
1513static struct rt6_info *fib6_find_prefix(struct net *net,
1514 struct fib6_table *table,
1515 struct fib6_node *fn)
1516{
1517 struct fib6_node *child_left, *child_right;
1518
1519 if (fn->fn_flags & RTN_ROOT)
1520 return net->ipv6.ip6_null_entry;
1521
1522 while (fn) {
1523 child_left = rcu_dereference_protected(fn->left,
1524 lockdep_is_held(&table->tb6_lock));
1525 child_right = rcu_dereference_protected(fn->right,
1526 lockdep_is_held(&table->tb6_lock));
1527 if (child_left)
1528 return rcu_dereference_protected(child_left->leaf,
1529 lockdep_is_held(&table->tb6_lock));
1530 if (child_right)
1531 return rcu_dereference_protected(child_right->leaf,
1532 lockdep_is_held(&table->tb6_lock));
1533
1534 fn = FIB6_SUBTREE(fn);
1535 }
1536 return NULL;
1537}
1538
1539/*
1540 * Called to trim the tree of intermediate nodes when possible. "fn"
1541 * is the node we want to try and remove.
1542 * Need to own table->tb6_lock
1543 */
1544
1545static struct fib6_node *fib6_repair_tree(struct net *net,
1546 struct fib6_table *table,
1547 struct fib6_node *fn)
1548{
1549 int children;
1550 int nstate;
1551 struct fib6_node *child;
1552 struct fib6_walker *w;
1553 int iter = 0;
1554
1555 /* Set fn->leaf to null_entry for root node. */
1556 if (fn->fn_flags & RTN_TL_ROOT) {
1557 rcu_assign_pointer(fn->leaf, net->ipv6.ip6_null_entry);
1558 return fn;
1559 }
1560
1561 for (;;) {
1562 struct fib6_node *fn_r = rcu_dereference_protected(fn->right,
1563 lockdep_is_held(&table->tb6_lock));
1564 struct fib6_node *fn_l = rcu_dereference_protected(fn->left,
1565 lockdep_is_held(&table->tb6_lock));
1566 struct fib6_node *pn = rcu_dereference_protected(fn->parent,
1567 lockdep_is_held(&table->tb6_lock));
1568 struct fib6_node *pn_r = rcu_dereference_protected(pn->right,
1569 lockdep_is_held(&table->tb6_lock));
1570 struct fib6_node *pn_l = rcu_dereference_protected(pn->left,
1571 lockdep_is_held(&table->tb6_lock));
1572 struct rt6_info *fn_leaf = rcu_dereference_protected(fn->leaf,
1573 lockdep_is_held(&table->tb6_lock));
1574 struct rt6_info *pn_leaf = rcu_dereference_protected(pn->leaf,
1575 lockdep_is_held(&table->tb6_lock));
1576 struct rt6_info *new_fn_leaf;
1577
1578 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1579 iter++;
1580
1581 WARN_ON(fn->fn_flags & RTN_RTINFO);
1582 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1583 WARN_ON(fn_leaf);
1584
1585 children = 0;
1586 child = NULL;
1587 if (fn_r)
1588 child = fn_r, children |= 1;
1589 if (fn_l)
1590 child = fn_l, children |= 2;
1591
1592 if (children == 3 || FIB6_SUBTREE(fn)
1593#ifdef CONFIG_IPV6_SUBTREES
1594 /* Subtree root (i.e. fn) may have one child */
1595 || (children && fn->fn_flags & RTN_ROOT)
1596#endif
1597 ) {
1598 new_fn_leaf = fib6_find_prefix(net, table, fn);
1599#if RT6_DEBUG >= 2
1600 if (!new_fn_leaf) {
1601 WARN_ON(!new_fn_leaf);
1602 new_fn_leaf = net->ipv6.ip6_null_entry;
1603 }
1604#endif
1605 atomic_inc(&new_fn_leaf->rt6i_ref);
1606 rcu_assign_pointer(fn->leaf, new_fn_leaf);
1607 return pn;
1608 }
1609
1610#ifdef CONFIG_IPV6_SUBTREES
1611 if (FIB6_SUBTREE(pn) == fn) {
1612 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1613 RCU_INIT_POINTER(pn->subtree, NULL);
1614 nstate = FWS_L;
1615 } else {
1616 WARN_ON(fn->fn_flags & RTN_ROOT);
1617#endif
1618 if (pn_r == fn)
1619 rcu_assign_pointer(pn->right, child);
1620 else if (pn_l == fn)
1621 rcu_assign_pointer(pn->left, child);
1622#if RT6_DEBUG >= 2
1623 else
1624 WARN_ON(1);
1625#endif
1626 if (child)
1627 rcu_assign_pointer(child->parent, pn);
1628 nstate = FWS_R;
1629#ifdef CONFIG_IPV6_SUBTREES
1630 }
1631#endif
1632
1633 read_lock(&net->ipv6.fib6_walker_lock);
1634 FOR_WALKERS(net, w) {
1635 if (!child) {
1636 if (w->node == fn) {
1637 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1638 w->node = pn;
1639 w->state = nstate;
1640 }
1641 } else {
1642 if (w->node == fn) {
1643 w->node = child;
1644 if (children&2) {
1645 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1646 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT;
1647 } else {
1648 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1649 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT;
1650 }
1651 }
1652 }
1653 }
1654 read_unlock(&net->ipv6.fib6_walker_lock);
1655
1656 node_free(net, fn);
1657 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
1658 return pn;
1659
1660 RCU_INIT_POINTER(pn->leaf, NULL);
1661 rt6_release(pn_leaf);
1662 fn = pn;
1663 }
1664}
1665
1666static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
1667 struct rt6_info __rcu **rtp, struct nl_info *info)
1668{
1669 struct fib6_walker *w;
1670 struct rt6_info *rt = rcu_dereference_protected(*rtp,
1671 lockdep_is_held(&table->tb6_lock));
1672 struct net *net = info->nl_net;
1673
1674 RT6_TRACE("fib6_del_route\n");
1675
1676 WARN_ON_ONCE(rt->rt6i_flags & RTF_CACHE);
1677
1678 /* Unlink it */
1679 *rtp = rt->rt6_next;
1680 rt->rt6i_node = NULL;
1681 net->ipv6.rt6_stats->fib_rt_entries--;
1682 net->ipv6.rt6_stats->fib_discarded_routes++;
1683
1684 /* Flush all cached dst in exception table */
1685 rt6_flush_exceptions(rt);
1686
1687 /* Reset round-robin state, if necessary */
1688 if (rcu_access_pointer(fn->rr_ptr) == rt)
1689 fn->rr_ptr = NULL;
1690
1691 /* Remove this entry from other siblings */
1692 if (rt->rt6i_nsiblings) {
1693 struct rt6_info *sibling, *next_sibling;
1694
1695 list_for_each_entry_safe(sibling, next_sibling,
1696 &rt->rt6i_siblings, rt6i_siblings)
1697 sibling->rt6i_nsiblings--;
1698 rt->rt6i_nsiblings = 0;
1699 list_del_init(&rt->rt6i_siblings);
1700 rt6_multipath_rebalance(next_sibling);
1701 }
1702
1703 /* Adjust walkers */
1704 read_lock(&net->ipv6.fib6_walker_lock);
1705 FOR_WALKERS(net, w) {
1706 if (w->state == FWS_C && w->leaf == rt) {
1707 RT6_TRACE("walker %p adjusted by delroute\n", w);
1708 w->leaf = rcu_dereference_protected(rt->rt6_next,
1709 lockdep_is_held(&table->tb6_lock));
1710 if (!w->leaf)
1711 w->state = FWS_U;
1712 }
1713 }
1714 read_unlock(&net->ipv6.fib6_walker_lock);
1715
1716 /* If it was last route, call fib6_repair_tree() to:
1717 * 1. For root node, put back null_entry as how the table was created.
1718 * 2. For other nodes, expunge its radix tree node.
1719 */
1720 if (!rcu_access_pointer(fn->leaf)) {
1721 if (!(fn->fn_flags & RTN_TL_ROOT)) {
1722 fn->fn_flags &= ~RTN_RTINFO;
1723 net->ipv6.rt6_stats->fib_route_nodes--;
1724 }
1725 fn = fib6_repair_tree(net, table, fn);
1726 }
1727
1728 fib6_purge_rt(rt, fn, net);
1729
1730 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL);
1731 if (!info->skip_notify)
1732 inet6_rt_notify(RTM_DELROUTE, rt, info, 0);
1733 rt6_release(rt);
1734}
1735
1736/* Need to own table->tb6_lock */
1737int fib6_del(struct rt6_info *rt, struct nl_info *info)
1738{
1739 struct fib6_node *fn = rcu_dereference_protected(rt->rt6i_node,
1740 lockdep_is_held(&rt->rt6i_table->tb6_lock));
1741 struct fib6_table *table = rt->rt6i_table;
1742 struct net *net = info->nl_net;
1743 struct rt6_info __rcu **rtp;
1744 struct rt6_info __rcu **rtp_next;
1745
1746#if RT6_DEBUG >= 2
1747 if (rt->dst.obsolete > 0) {
1748 WARN_ON(fn);
1749 return -ENOENT;
1750 }
1751#endif
1752 if (!fn || rt == net->ipv6.ip6_null_entry)
1753 return -ENOENT;
1754
1755 WARN_ON(!(fn->fn_flags & RTN_RTINFO));
1756
1757 /* remove cached dst from exception table */
1758 if (rt->rt6i_flags & RTF_CACHE)
1759 return rt6_remove_exception_rt(rt);
1760
1761 /*
1762 * Walk the leaf entries looking for ourself
1763 */
1764
1765 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) {
1766 struct rt6_info *cur = rcu_dereference_protected(*rtp,
1767 lockdep_is_held(&table->tb6_lock));
1768 if (rt == cur) {
1769 fib6_del_route(table, fn, rtp, info);
1770 return 0;
1771 }
1772 rtp_next = &cur->rt6_next;
1773 }
1774 return -ENOENT;
1775}
1776
1777/*
1778 * Tree traversal function.
1779 *
1780 * Certainly, it is not interrupt safe.
1781 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1782 * It means, that we can modify tree during walking
1783 * and use this function for garbage collection, clone pruning,
1784 * cleaning tree when a device goes down etc. etc.
1785 *
1786 * It guarantees that every node will be traversed,
1787 * and that it will be traversed only once.
1788 *
1789 * Callback function w->func may return:
1790 * 0 -> continue walking.
1791 * positive value -> walking is suspended (used by tree dumps,
1792 * and probably by gc, if it will be split to several slices)
1793 * negative value -> terminate walking.
1794 *
1795 * The function itself returns:
1796 * 0 -> walk is complete.
1797 * >0 -> walk is incomplete (i.e. suspended)
1798 * <0 -> walk is terminated by an error.
1799 *
1800 * This function is called with tb6_lock held.
1801 */
1802
1803static int fib6_walk_continue(struct fib6_walker *w)
1804{
1805 struct fib6_node *fn, *pn, *left, *right;
1806
1807 /* w->root should always be table->tb6_root */
1808 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT));
1809
1810 for (;;) {
1811 fn = w->node;
1812 if (!fn)
1813 return 0;
1814
1815 switch (w->state) {
1816#ifdef CONFIG_IPV6_SUBTREES
1817 case FWS_S:
1818 if (FIB6_SUBTREE(fn)) {
1819 w->node = FIB6_SUBTREE(fn);
1820 continue;
1821 }
1822 w->state = FWS_L;
1823#endif
1824 /* fall through */
1825 case FWS_L:
1826 left = rcu_dereference_protected(fn->left, 1);
1827 if (left) {
1828 w->node = left;
1829 w->state = FWS_INIT;
1830 continue;
1831 }
1832 w->state = FWS_R;
1833 /* fall through */
1834 case FWS_R:
1835 right = rcu_dereference_protected(fn->right, 1);
1836 if (right) {
1837 w->node = right;
1838 w->state = FWS_INIT;
1839 continue;
1840 }
1841 w->state = FWS_C;
1842 w->leaf = rcu_dereference_protected(fn->leaf, 1);
1843 /* fall through */
1844 case FWS_C:
1845 if (w->leaf && fn->fn_flags & RTN_RTINFO) {
1846 int err;
1847
1848 if (w->skip) {
1849 w->skip--;
1850 goto skip;
1851 }
1852
1853 err = w->func(w);
1854 if (err)
1855 return err;
1856
1857 w->count++;
1858 continue;
1859 }
1860skip:
1861 w->state = FWS_U;
1862 /* fall through */
1863 case FWS_U:
1864 if (fn == w->root)
1865 return 0;
1866 pn = rcu_dereference_protected(fn->parent, 1);
1867 left = rcu_dereference_protected(pn->left, 1);
1868 right = rcu_dereference_protected(pn->right, 1);
1869 w->node = pn;
1870#ifdef CONFIG_IPV6_SUBTREES
1871 if (FIB6_SUBTREE(pn) == fn) {
1872 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1873 w->state = FWS_L;
1874 continue;
1875 }
1876#endif
1877 if (left == fn) {
1878 w->state = FWS_R;
1879 continue;
1880 }
1881 if (right == fn) {
1882 w->state = FWS_C;
1883 w->leaf = rcu_dereference_protected(w->node->leaf, 1);
1884 continue;
1885 }
1886#if RT6_DEBUG >= 2
1887 WARN_ON(1);
1888#endif
1889 }
1890 }
1891}
1892
1893static int fib6_walk(struct net *net, struct fib6_walker *w)
1894{
1895 int res;
1896
1897 w->state = FWS_INIT;
1898 w->node = w->root;
1899
1900 fib6_walker_link(net, w);
1901 res = fib6_walk_continue(w);
1902 if (res <= 0)
1903 fib6_walker_unlink(net, w);
1904 return res;
1905}
1906
1907static int fib6_clean_node(struct fib6_walker *w)
1908{
1909 int res;
1910 struct rt6_info *rt;
1911 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w);
1912 struct nl_info info = {
1913 .nl_net = c->net,
1914 };
1915
1916 if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
1917 w->node->fn_sernum != c->sernum)
1918 w->node->fn_sernum = c->sernum;
1919
1920 if (!c->func) {
1921 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE);
1922 w->leaf = NULL;
1923 return 0;
1924 }
1925
1926 for_each_fib6_walker_rt(w) {
1927 res = c->func(rt, c->arg);
1928 if (res == -1) {
1929 w->leaf = rt;
1930 res = fib6_del(rt, &info);
1931 if (res) {
1932#if RT6_DEBUG >= 2
1933 pr_debug("%s: del failed: rt=%p@%p err=%d\n",
1934 __func__, rt,
1935 rcu_access_pointer(rt->rt6i_node),
1936 res);
1937#endif
1938 continue;
1939 }
1940 return 0;
1941 } else if (res == -2) {
1942 if (WARN_ON(!rt->rt6i_nsiblings))
1943 continue;
1944 rt = list_last_entry(&rt->rt6i_siblings,
1945 struct rt6_info, rt6i_siblings);
1946 continue;
1947 }
1948 WARN_ON(res != 0);
1949 }
1950 w->leaf = rt;
1951 return 0;
1952}
1953
1954/*
1955 * Convenient frontend to tree walker.
1956 *
1957 * func is called on each route.
1958 * It may return -2 -> skip multipath route.
1959 * -1 -> delete this route.
1960 * 0 -> continue walking
1961 */
1962
1963static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1964 int (*func)(struct rt6_info *, void *arg),
1965 int sernum, void *arg)
1966{
1967 struct fib6_cleaner c;
1968
1969 c.w.root = root;
1970 c.w.func = fib6_clean_node;
1971 c.w.count = 0;
1972 c.w.skip = 0;
1973 c.func = func;
1974 c.sernum = sernum;
1975 c.arg = arg;
1976 c.net = net;
1977
1978 fib6_walk(net, &c.w);
1979}
1980
1981static void __fib6_clean_all(struct net *net,
1982 int (*func)(struct rt6_info *, void *),
1983 int sernum, void *arg)
1984{
1985 struct fib6_table *table;
1986 struct hlist_head *head;
1987 unsigned int h;
1988
1989 rcu_read_lock();
1990 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
1991 head = &net->ipv6.fib_table_hash[h];
1992 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
1993 spin_lock_bh(&table->tb6_lock);
1994 fib6_clean_tree(net, &table->tb6_root,
1995 func, sernum, arg);
1996 spin_unlock_bh(&table->tb6_lock);
1997 }
1998 }
1999 rcu_read_unlock();
2000}
2001
2002void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *),
2003 void *arg)
2004{
2005 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg);
2006}
2007
2008static void fib6_flush_trees(struct net *net)
2009{
2010 int new_sernum = fib6_new_sernum(net);
2011
2012 __fib6_clean_all(net, NULL, new_sernum, NULL);
2013}
2014
2015/*
2016 * Garbage collection
2017 */
2018
2019static int fib6_age(struct rt6_info *rt, void *arg)
2020{
2021 struct fib6_gc_args *gc_args = arg;
2022 unsigned long now = jiffies;
2023
2024 /*
2025 * check addrconf expiration here.
2026 * Routes are expired even if they are in use.
2027 */
2028
2029 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) {
2030 if (time_after(now, rt->dst.expires)) {
2031 RT6_TRACE("expiring %p\n", rt);
2032 return -1;
2033 }
2034 gc_args->more++;
2035 }
2036
2037 /* Also age clones in the exception table.
2038 * Note, that clones are aged out
2039 * only if they are not in use now.
2040 */
2041 rt6_age_exceptions(rt, gc_args, now);
2042
2043 return 0;
2044}
2045
2046void fib6_run_gc(unsigned long expires, struct net *net, bool force)
2047{
2048 struct fib6_gc_args gc_args;
2049 unsigned long now;
2050
2051 if (force) {
2052 spin_lock_bh(&net->ipv6.fib6_gc_lock);
2053 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) {
2054 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
2055 return;
2056 }
2057 gc_args.timeout = expires ? (int)expires :
2058 net->ipv6.sysctl.ip6_rt_gc_interval;
2059 gc_args.more = 0;
2060
2061 fib6_clean_all(net, fib6_age, &gc_args);
2062 now = jiffies;
2063 net->ipv6.ip6_rt_last_gc = now;
2064
2065 if (gc_args.more)
2066 mod_timer(&net->ipv6.ip6_fib_timer,
2067 round_jiffies(now
2068 + net->ipv6.sysctl.ip6_rt_gc_interval));
2069 else
2070 del_timer(&net->ipv6.ip6_fib_timer);
2071 spin_unlock_bh(&net->ipv6.fib6_gc_lock);
2072}
2073
2074static void fib6_gc_timer_cb(struct timer_list *t)
2075{
2076 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer);
2077
2078 fib6_run_gc(0, arg, true);
2079}
2080
2081static int __net_init fib6_net_init(struct net *net)
2082{
2083 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
2084 int err;
2085
2086 err = fib6_notifier_init(net);
2087 if (err)
2088 return err;
2089
2090 spin_lock_init(&net->ipv6.fib6_gc_lock);
2091 rwlock_init(&net->ipv6.fib6_walker_lock);
2092 INIT_LIST_HEAD(&net->ipv6.fib6_walkers);
2093 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0);
2094
2095 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
2096 if (!net->ipv6.rt6_stats)
2097 goto out_timer;
2098
2099 /* Avoid false sharing : Use at least a full cache line */
2100 size = max_t(size_t, size, L1_CACHE_BYTES);
2101
2102 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
2103 if (!net->ipv6.fib_table_hash)
2104 goto out_rt6_stats;
2105
2106 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
2107 GFP_KERNEL);
2108 if (!net->ipv6.fib6_main_tbl)
2109 goto out_fib_table_hash;
2110
2111 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
2112 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf,
2113 net->ipv6.ip6_null_entry);
2114 net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
2115 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
2116 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
2117
2118#ifdef CONFIG_IPV6_MULTIPLE_TABLES
2119 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
2120 GFP_KERNEL);
2121 if (!net->ipv6.fib6_local_tbl)
2122 goto out_fib6_main_tbl;
2123 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
2124 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf,
2125 net->ipv6.ip6_null_entry);
2126 net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
2127 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
2128 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
2129#endif
2130 fib6_tables_init(net);
2131
2132 return 0;
2133
2134#ifdef CONFIG_IPV6_MULTIPLE_TABLES
2135out_fib6_main_tbl:
2136 kfree(net->ipv6.fib6_main_tbl);
2137#endif
2138out_fib_table_hash:
2139 kfree(net->ipv6.fib_table_hash);
2140out_rt6_stats:
2141 kfree(net->ipv6.rt6_stats);
2142out_timer:
2143 fib6_notifier_exit(net);
2144 return -ENOMEM;
2145}
2146
2147static void fib6_net_exit(struct net *net)
2148{
2149 unsigned int i;
2150
2151 del_timer_sync(&net->ipv6.ip6_fib_timer);
2152
2153 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) {
2154 struct hlist_head *head = &net->ipv6.fib_table_hash[i];
2155 struct hlist_node *tmp;
2156 struct fib6_table *tb;
2157
2158 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) {
2159 hlist_del(&tb->tb6_hlist);
2160 fib6_free_table(tb);
2161 }
2162 }
2163
2164 kfree(net->ipv6.fib_table_hash);
2165 kfree(net->ipv6.rt6_stats);
2166 fib6_notifier_exit(net);
2167}
2168
2169static struct pernet_operations fib6_net_ops = {
2170 .init = fib6_net_init,
2171 .exit = fib6_net_exit,
2172};
2173
2174int __init fib6_init(void)
2175{
2176 int ret = -ENOMEM;
2177
2178 fib6_node_kmem = kmem_cache_create("fib6_nodes",
2179 sizeof(struct fib6_node),
2180 0, SLAB_HWCACHE_ALIGN,
2181 NULL);
2182 if (!fib6_node_kmem)
2183 goto out;
2184
2185 ret = register_pernet_subsys(&fib6_net_ops);
2186 if (ret)
2187 goto out_kmem_cache_create;
2188
2189 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL,
2190 inet6_dump_fib, 0);
2191 if (ret)
2192 goto out_unregister_subsys;
2193
2194 __fib6_flush_trees = fib6_flush_trees;
2195out:
2196 return ret;
2197
2198out_unregister_subsys:
2199 unregister_pernet_subsys(&fib6_net_ops);
2200out_kmem_cache_create:
2201 kmem_cache_destroy(fib6_node_kmem);
2202 goto out;
2203}
2204
2205void fib6_gc_cleanup(void)
2206{
2207 unregister_pernet_subsys(&fib6_net_ops);
2208 kmem_cache_destroy(fib6_node_kmem);
2209}
2210
2211#ifdef CONFIG_PROC_FS
2212
2213struct ipv6_route_iter {
2214 struct seq_net_private p;
2215 struct fib6_walker w;
2216 loff_t skip;
2217 struct fib6_table *tbl;
2218 int sernum;
2219};
2220
2221static int ipv6_route_seq_show(struct seq_file *seq, void *v)
2222{
2223 struct rt6_info *rt = v;
2224 struct ipv6_route_iter *iter = seq->private;
2225
2226 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen);
2227
2228#ifdef CONFIG_IPV6_SUBTREES
2229 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen);
2230#else
2231 seq_puts(seq, "00000000000000000000000000000000 00 ");
2232#endif
2233 if (rt->rt6i_flags & RTF_GATEWAY)
2234 seq_printf(seq, "%pi6", &rt->rt6i_gateway);
2235 else
2236 seq_puts(seq, "00000000000000000000000000000000");
2237
2238 seq_printf(seq, " %08x %08x %08x %08x %8s\n",
2239 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt),
2240 rt->dst.__use, rt->rt6i_flags,
2241 rt->dst.dev ? rt->dst.dev->name : "");
2242 iter->w.leaf = NULL;
2243 return 0;
2244}
2245
2246static int ipv6_route_yield(struct fib6_walker *w)
2247{
2248 struct ipv6_route_iter *iter = w->args;
2249
2250 if (!iter->skip)
2251 return 1;
2252
2253 do {
2254 iter->w.leaf = rcu_dereference_protected(
2255 iter->w.leaf->rt6_next,
2256 lockdep_is_held(&iter->tbl->tb6_lock));
2257 iter->skip--;
2258 if (!iter->skip && iter->w.leaf)
2259 return 1;
2260 } while (iter->w.leaf);
2261
2262 return 0;
2263}
2264
2265static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter,
2266 struct net *net)
2267{
2268 memset(&iter->w, 0, sizeof(iter->w));
2269 iter->w.func = ipv6_route_yield;
2270 iter->w.root = &iter->tbl->tb6_root;
2271 iter->w.state = FWS_INIT;
2272 iter->w.node = iter->w.root;
2273 iter->w.args = iter;
2274 iter->sernum = iter->w.root->fn_sernum;
2275 INIT_LIST_HEAD(&iter->w.lh);
2276 fib6_walker_link(net, &iter->w);
2277}
2278
2279static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
2280 struct net *net)
2281{
2282 unsigned int h;
2283 struct hlist_node *node;
2284
2285 if (tbl) {
2286 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1;
2287 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist));
2288 } else {
2289 h = 0;
2290 node = NULL;
2291 }
2292
2293 while (!node && h < FIB6_TABLE_HASHSZ) {
2294 node = rcu_dereference_bh(
2295 hlist_first_rcu(&net->ipv6.fib_table_hash[h++]));
2296 }
2297 return hlist_entry_safe(node, struct fib6_table, tb6_hlist);
2298}
2299
2300static void ipv6_route_check_sernum(struct ipv6_route_iter *iter)
2301{
2302 if (iter->sernum != iter->w.root->fn_sernum) {
2303 iter->sernum = iter->w.root->fn_sernum;
2304 iter->w.state = FWS_INIT;
2305 iter->w.node = iter->w.root;
2306 WARN_ON(iter->w.skip);
2307 iter->w.skip = iter->w.count;
2308 }
2309}
2310
2311static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2312{
2313 int r;
2314 struct rt6_info *n;
2315 struct net *net = seq_file_net(seq);
2316 struct ipv6_route_iter *iter = seq->private;
2317
2318 if (!v)
2319 goto iter_table;
2320
2321 n = rcu_dereference_bh(((struct rt6_info *)v)->rt6_next);
2322 if (n) {
2323 ++*pos;
2324 return n;
2325 }
2326
2327iter_table:
2328 ipv6_route_check_sernum(iter);
2329 spin_lock_bh(&iter->tbl->tb6_lock);
2330 r = fib6_walk_continue(&iter->w);
2331 spin_unlock_bh(&iter->tbl->tb6_lock);
2332 if (r > 0) {
2333 if (v)
2334 ++*pos;
2335 return iter->w.leaf;
2336 } else if (r < 0) {
2337 fib6_walker_unlink(net, &iter->w);
2338 return NULL;
2339 }
2340 fib6_walker_unlink(net, &iter->w);
2341
2342 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
2343 if (!iter->tbl)
2344 return NULL;
2345
2346 ipv6_route_seq_setup_walk(iter, net);
2347 goto iter_table;
2348}
2349
2350static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
2351 __acquires(RCU_BH)
2352{
2353 struct net *net = seq_file_net(seq);
2354 struct ipv6_route_iter *iter = seq->private;
2355
2356 rcu_read_lock_bh();
2357 iter->tbl = ipv6_route_seq_next_table(NULL, net);
2358 iter->skip = *pos;
2359
2360 if (iter->tbl) {
2361 ipv6_route_seq_setup_walk(iter, net);
2362 return ipv6_route_seq_next(seq, NULL, pos);
2363 } else {
2364 return NULL;
2365 }
2366}
2367
2368static bool ipv6_route_iter_active(struct ipv6_route_iter *iter)
2369{
2370 struct fib6_walker *w = &iter->w;
2371 return w->node && !(w->state == FWS_U && w->node == w->root);
2372}
2373
2374static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
2375 __releases(RCU_BH)
2376{
2377 struct net *net = seq_file_net(seq);
2378 struct ipv6_route_iter *iter = seq->private;
2379
2380 if (ipv6_route_iter_active(iter))
2381 fib6_walker_unlink(net, &iter->w);
2382
2383 rcu_read_unlock_bh();
2384}
2385
2386static const struct seq_operations ipv6_route_seq_ops = {
2387 .start = ipv6_route_seq_start,
2388 .next = ipv6_route_seq_next,
2389 .stop = ipv6_route_seq_stop,
2390 .show = ipv6_route_seq_show
2391};
2392
2393int ipv6_route_open(struct inode *inode, struct file *file)
2394{
2395 return seq_open_net(inode, file, &ipv6_route_seq_ops,
2396 sizeof(struct ipv6_route_iter));
2397}
2398
2399#endif /* CONFIG_PROC_FS */