1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Linux INET6 implementation
4 * Forwarding Information Database
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Changes:
10 * Yuji SEKIYA @USAGI: Support default route on router node;
11 * remove ip6_null_entry from the top of
12 * routing table.
13 * Ville Nuorvala: Fixed routing subtrees.
14 */
15
16 #define pr_fmt(fmt) "IPv6: " fmt
17
18 #include <linux/errno.h>
19 #include <linux/types.h>
20 #include <linux/net.h>
21 #include <linux/route.h>
22 #include <linux/netdevice.h>
23 #include <linux/in6.h>
24 #include <linux/init.h>
25 #include <linux/list.h>
26 #include <linux/slab.h>
27
28 #include <net/ip.h>
29 #include <net/ipv6.h>
30 #include <net/ndisc.h>
31 #include <net/addrconf.h>
32 #include <net/lwtunnel.h>
33 #include <net/fib_notifier.h>
34
35 #include <net/ip6_fib.h>
36 #include <net/ip6_route.h>
37
38 static struct kmem_cache *fib6_node_kmem __read_mostly;
39
40 struct fib6_cleaner {
41 struct fib6_walker w;
42 struct net *net;
43 int (*func)(struct fib6_info *, void *arg);
44 int sernum;
45 void *arg;
46 bool skip_notify;
47 };
48
49 #ifdef CONFIG_IPV6_SUBTREES
50 #define FWS_INIT FWS_S
51 #else
52 #define FWS_INIT FWS_L
53 #endif
54
55 static struct fib6_info *fib6_find_prefix(struct net *net,
56 struct fib6_table *table,
57 struct fib6_node *fn);
58 static struct fib6_node *fib6_repair_tree(struct net *net,
59 struct fib6_table *table,
60 struct fib6_node *fn);
61 static int fib6_walk(struct net *net, struct fib6_walker *w);
62 static int fib6_walk_continue(struct fib6_walker *w);
63
64 /*
65 * A routing update causes an increase of the serial number on the
66 * affected subtree. This allows for cached routes to be asynchronously
67 * tested when modifications are made to the destination cache as a
68 * result of redirects, path MTU changes, etc.
69 */
70
71 static void fib6_gc_timer_cb(struct timer_list *t);
72
73 #define FOR_WALKERS(net, w) \
74 list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh)
75
fib6_walker_link(struct net * net,struct fib6_walker * w)76 static void fib6_walker_link(struct net *net, struct fib6_walker *w)
77 {
78 write_lock_bh(&net->ipv6.fib6_walker_lock);
79 list_add(&w->lh, &net->ipv6.fib6_walkers);
80 write_unlock_bh(&net->ipv6.fib6_walker_lock);
81 }
82
fib6_walker_unlink(struct net * net,struct fib6_walker * w)83 static void fib6_walker_unlink(struct net *net, struct fib6_walker *w)
84 {
85 write_lock_bh(&net->ipv6.fib6_walker_lock);
86 list_del(&w->lh);
87 write_unlock_bh(&net->ipv6.fib6_walker_lock);
88 }
89
fib6_new_sernum(struct net * net)90 static int fib6_new_sernum(struct net *net)
91 {
92 int new, old;
93
94 do {
95 old = atomic_read(&net->ipv6.fib6_sernum);
96 new = old < INT_MAX ? old + 1 : 1;
97 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum,
98 old, new) != old);
99 return new;
100 }
101
102 enum {
103 FIB6_NO_SERNUM_CHANGE = 0,
104 };
105
fib6_update_sernum(struct net * net,struct fib6_info * f6i)106 void fib6_update_sernum(struct net *net, struct fib6_info *f6i)
107 {
108 struct fib6_node *fn;
109
110 fn = rcu_dereference_protected(f6i->fib6_node,
111 lockdep_is_held(&f6i->fib6_table->tb6_lock));
112 if (fn)
113 fn->fn_sernum = fib6_new_sernum(net);
114 }
115
116 /*
117 * Auxiliary address test functions for the radix tree.
118 *
119 * These assume a 32bit processor (although it will work on
120 * 64bit processors)
121 */
122
123 /*
124 * test bit
125 */
126 #if defined(__LITTLE_ENDIAN)
127 # define BITOP_BE32_SWIZZLE (0x1F & ~7)
128 #else
129 # define BITOP_BE32_SWIZZLE 0
130 #endif
131
addr_bit_set(const void * token,int fn_bit)132 static __be32 addr_bit_set(const void *token, int fn_bit)
133 {
134 const __be32 *addr = token;
135 /*
136 * Here,
137 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
138 * is optimized version of
139 * htonl(1 << ((~fn_bit)&0x1F))
140 * See include/asm-generic/bitops/le.h.
141 */
142 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
143 addr[fn_bit >> 5];
144 }
145
fib6_info_alloc(gfp_t gfp_flags,bool with_fib6_nh)146 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh)
147 {
148 struct fib6_info *f6i;
149 size_t sz = sizeof(*f6i);
150
151 if (with_fib6_nh)
152 sz += sizeof(struct fib6_nh);
153
154 f6i = kzalloc(sz, gfp_flags);
155 if (!f6i)
156 return NULL;
157
158 /* fib6_siblings is a union with nh_list, so this initializes both */
159 INIT_LIST_HEAD(&f6i->fib6_siblings);
160 refcount_set(&f6i->fib6_ref, 1);
161
162 return f6i;
163 }
164
fib6_info_destroy_rcu(struct rcu_head * head)165 void fib6_info_destroy_rcu(struct rcu_head *head)
166 {
167 struct fib6_info *f6i = container_of(head, struct fib6_info, rcu);
168
169 WARN_ON(f6i->fib6_node);
170
171 if (f6i->nh)
172 nexthop_put(f6i->nh);
173 else
174 fib6_nh_release(f6i->fib6_nh);
175
176 ip_fib_metrics_put(f6i->fib6_metrics);
177 kfree(f6i);
178 }
179 EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu);
180
node_alloc(struct net * net)181 static struct fib6_node *node_alloc(struct net *net)
182 {
183 struct fib6_node *fn;
184
185 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
186 if (fn)
187 net->ipv6.rt6_stats->fib_nodes++;
188
189 return fn;
190 }
191
node_free_immediate(struct net * net,struct fib6_node * fn)192 static void node_free_immediate(struct net *net, struct fib6_node *fn)
193 {
194 kmem_cache_free(fib6_node_kmem, fn);
195 net->ipv6.rt6_stats->fib_nodes--;
196 }
197
node_free_rcu(struct rcu_head * head)198 static void node_free_rcu(struct rcu_head *head)
199 {
200 struct fib6_node *fn = container_of(head, struct fib6_node, rcu);
201
202 kmem_cache_free(fib6_node_kmem, fn);
203 }
204
node_free(struct net * net,struct fib6_node * fn)205 static void node_free(struct net *net, struct fib6_node *fn)
206 {
207 call_rcu(&fn->rcu, node_free_rcu);
208 net->ipv6.rt6_stats->fib_nodes--;
209 }
210
fib6_free_table(struct fib6_table * table)211 static void fib6_free_table(struct fib6_table *table)
212 {
213 inetpeer_invalidate_tree(&table->tb6_peers);
214 kfree(table);
215 }
216
fib6_link_table(struct net * net,struct fib6_table * tb)217 static void fib6_link_table(struct net *net, struct fib6_table *tb)
218 {
219 unsigned int h;
220
221 /*
222 * Initialize table lock at a single place to give lockdep a key,
223 * tables aren't visible prior to being linked to the list.
224 */
225 spin_lock_init(&tb->tb6_lock);
226 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
227
228 /*
229 * No protection necessary, this is the only list mutatation
230 * operation, tables never disappear once they exist.
231 */
232 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
233 }
234
235 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
236
fib6_alloc_table(struct net * net,u32 id)237 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
238 {
239 struct fib6_table *table;
240
241 table = kzalloc(sizeof(*table), GFP_ATOMIC);
242 if (table) {
243 table->tb6_id = id;
244 rcu_assign_pointer(table->tb6_root.leaf,
245 net->ipv6.fib6_null_entry);
246 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
247 inet_peer_base_init(&table->tb6_peers);
248 }
249
250 return table;
251 }
252
fib6_new_table(struct net * net,u32 id)253 struct fib6_table *fib6_new_table(struct net *net, u32 id)
254 {
255 struct fib6_table *tb;
256
257 if (id == 0)
258 id = RT6_TABLE_MAIN;
259 tb = fib6_get_table(net, id);
260 if (tb)
261 return tb;
262
263 tb = fib6_alloc_table(net, id);
264 if (tb)
265 fib6_link_table(net, tb);
266
267 return tb;
268 }
269 EXPORT_SYMBOL_GPL(fib6_new_table);
270
fib6_get_table(struct net * net,u32 id)271 struct fib6_table *fib6_get_table(struct net *net, u32 id)
272 {
273 struct fib6_table *tb;
274 struct hlist_head *head;
275 unsigned int h;
276
277 if (id == 0)
278 id = RT6_TABLE_MAIN;
279 h = id & (FIB6_TABLE_HASHSZ - 1);
280 rcu_read_lock();
281 head = &net->ipv6.fib_table_hash[h];
282 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
283 if (tb->tb6_id == id) {
284 rcu_read_unlock();
285 return tb;
286 }
287 }
288 rcu_read_unlock();
289
290 return NULL;
291 }
292 EXPORT_SYMBOL_GPL(fib6_get_table);
293
fib6_tables_init(struct net * net)294 static void __net_init fib6_tables_init(struct net *net)
295 {
296 fib6_link_table(net, net->ipv6.fib6_main_tbl);
297 fib6_link_table(net, net->ipv6.fib6_local_tbl);
298 }
299 #else
300
fib6_new_table(struct net * net,u32 id)301 struct fib6_table *fib6_new_table(struct net *net, u32 id)
302 {
303 return fib6_get_table(net, id);
304 }
305
fib6_get_table(struct net * net,u32 id)306 struct fib6_table *fib6_get_table(struct net *net, u32 id)
307 {
308 return net->ipv6.fib6_main_tbl;
309 }
310
fib6_rule_lookup(struct net * net,struct flowi6 * fl6,const struct sk_buff * skb,int flags,pol_lookup_t lookup)311 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
312 const struct sk_buff *skb,
313 int flags, pol_lookup_t lookup)
314 {
315 struct rt6_info *rt;
316
317 rt = pol_lookup_func(lookup,
318 net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
319 if (rt->dst.error == -EAGAIN) {
320 ip6_rt_put_flags(rt, flags);
321 rt = net->ipv6.ip6_null_entry;
322 if (!(flags & RT6_LOOKUP_F_DST_NOREF))
323 dst_hold(&rt->dst);
324 }
325
326 return &rt->dst;
327 }
328
329 /* called with rcu lock held; no reference taken on fib6_info */
fib6_lookup(struct net * net,int oif,struct flowi6 * fl6,struct fib6_result * res,int flags)330 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
331 struct fib6_result *res, int flags)
332 {
333 return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6,
334 res, flags);
335 }
336
fib6_tables_init(struct net * net)337 static void __net_init fib6_tables_init(struct net *net)
338 {
339 fib6_link_table(net, net->ipv6.fib6_main_tbl);
340 }
341
342 #endif
343
fib6_tables_seq_read(struct net * net)344 unsigned int fib6_tables_seq_read(struct net *net)
345 {
346 unsigned int h, fib_seq = 0;
347
348 rcu_read_lock();
349 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
350 struct hlist_head *head = &net->ipv6.fib_table_hash[h];
351 struct fib6_table *tb;
352
353 hlist_for_each_entry_rcu(tb, head, tb6_hlist)
354 fib_seq += tb->fib_seq;
355 }
356 rcu_read_unlock();
357
358 return fib_seq;
359 }
360
call_fib6_entry_notifier(struct notifier_block * nb,enum fib_event_type event_type,struct fib6_info * rt,struct netlink_ext_ack * extack)361 static int call_fib6_entry_notifier(struct notifier_block *nb,
362 enum fib_event_type event_type,
363 struct fib6_info *rt,
364 struct netlink_ext_ack *extack)
365 {
366 struct fib6_entry_notifier_info info = {
367 .info.extack = extack,
368 .rt = rt,
369 };
370
371 return call_fib6_notifier(nb, event_type, &info.info);
372 }
373
call_fib6_multipath_entry_notifier(struct notifier_block * nb,enum fib_event_type event_type,struct fib6_info * rt,unsigned int nsiblings,struct netlink_ext_ack * extack)374 static int call_fib6_multipath_entry_notifier(struct notifier_block *nb,
375 enum fib_event_type event_type,
376 struct fib6_info *rt,
377 unsigned int nsiblings,
378 struct netlink_ext_ack *extack)
379 {
380 struct fib6_entry_notifier_info info = {
381 .info.extack = extack,
382 .rt = rt,
383 .nsiblings = nsiblings,
384 };
385
386 return call_fib6_notifier(nb, event_type, &info.info);
387 }
388
call_fib6_entry_notifiers(struct net * net,enum fib_event_type event_type,struct fib6_info * rt,struct netlink_ext_ack * extack)389 int call_fib6_entry_notifiers(struct net *net,
390 enum fib_event_type event_type,
391 struct fib6_info *rt,
392 struct netlink_ext_ack *extack)
393 {
394 struct fib6_entry_notifier_info info = {
395 .info.extack = extack,
396 .rt = rt,
397 };
398
399 rt->fib6_table->fib_seq++;
400 return call_fib6_notifiers(net, event_type, &info.info);
401 }
402
call_fib6_multipath_entry_notifiers(struct net * net,enum fib_event_type event_type,struct fib6_info * rt,unsigned int nsiblings,struct netlink_ext_ack * extack)403 int call_fib6_multipath_entry_notifiers(struct net *net,
404 enum fib_event_type event_type,
405 struct fib6_info *rt,
406 unsigned int nsiblings,
407 struct netlink_ext_ack *extack)
408 {
409 struct fib6_entry_notifier_info info = {
410 .info.extack = extack,
411 .rt = rt,
412 .nsiblings = nsiblings,
413 };
414
415 rt->fib6_table->fib_seq++;
416 return call_fib6_notifiers(net, event_type, &info.info);
417 }
418
call_fib6_entry_notifiers_replace(struct net * net,struct fib6_info * rt)419 int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt)
420 {
421 struct fib6_entry_notifier_info info = {
422 .rt = rt,
423 .nsiblings = rt->fib6_nsiblings,
424 };
425
426 rt->fib6_table->fib_seq++;
427 return call_fib6_notifiers(net, FIB_EVENT_ENTRY_REPLACE, &info.info);
428 }
429
430 struct fib6_dump_arg {
431 struct net *net;
432 struct notifier_block *nb;
433 struct netlink_ext_ack *extack;
434 };
435
fib6_rt_dump(struct fib6_info * rt,struct fib6_dump_arg * arg)436 static int fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg)
437 {
438 enum fib_event_type fib_event = FIB_EVENT_ENTRY_REPLACE;
439 int err;
440
441 if (!rt || rt == arg->net->ipv6.fib6_null_entry)
442 return 0;
443
444 if (rt->fib6_nsiblings)
445 err = call_fib6_multipath_entry_notifier(arg->nb, fib_event,
446 rt,
447 rt->fib6_nsiblings,
448 arg->extack);
449 else
450 err = call_fib6_entry_notifier(arg->nb, fib_event, rt,
451 arg->extack);
452
453 return err;
454 }
455
fib6_node_dump(struct fib6_walker * w)456 static int fib6_node_dump(struct fib6_walker *w)
457 {
458 int err;
459
460 err = fib6_rt_dump(w->leaf, w->args);
461 w->leaf = NULL;
462 return err;
463 }
464
fib6_table_dump(struct net * net,struct fib6_table * tb,struct fib6_walker * w)465 static int fib6_table_dump(struct net *net, struct fib6_table *tb,
466 struct fib6_walker *w)
467 {
468 int err;
469
470 w->root = &tb->tb6_root;
471 spin_lock_bh(&tb->tb6_lock);
472 err = fib6_walk(net, w);
473 spin_unlock_bh(&tb->tb6_lock);
474 return err;
475 }
476
477 /* Called with rcu_read_lock() */
fib6_tables_dump(struct net * net,struct notifier_block * nb,struct netlink_ext_ack * extack)478 int fib6_tables_dump(struct net *net, struct notifier_block *nb,
479 struct netlink_ext_ack *extack)
480 {
481 struct fib6_dump_arg arg;
482 struct fib6_walker *w;
483 unsigned int h;
484 int err = 0;
485
486 w = kzalloc(sizeof(*w), GFP_ATOMIC);
487 if (!w)
488 return -ENOMEM;
489
490 w->func = fib6_node_dump;
491 arg.net = net;
492 arg.nb = nb;
493 arg.extack = extack;
494 w->args = &arg;
495
496 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
497 struct hlist_head *head = &net->ipv6.fib_table_hash[h];
498 struct fib6_table *tb;
499
500 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
501 err = fib6_table_dump(net, tb, w);
502 if (err)
503 goto out;
504 }
505 }
506
507 out:
508 kfree(w);
509
510 /* The tree traversal function should never return a positive value. */
511 return err > 0 ? -EINVAL : err;
512 }
513
fib6_dump_node(struct fib6_walker * w)514 static int fib6_dump_node(struct fib6_walker *w)
515 {
516 int res;
517 struct fib6_info *rt;
518
519 for_each_fib6_walker_rt(w) {
520 res = rt6_dump_route(rt, w->args, w->skip_in_node);
521 if (res >= 0) {
522 /* Frame is full, suspend walking */
523 w->leaf = rt;
524
525 /* We'll restart from this node, so if some routes were
526 * already dumped, skip them next time.
527 */
528 w->skip_in_node += res;
529
530 return 1;
531 }
532 w->skip_in_node = 0;
533
534 /* Multipath routes are dumped in one route with the
535 * RTA_MULTIPATH attribute. Jump 'rt' to point to the
536 * last sibling of this route (no need to dump the
537 * sibling routes again)
538 */
539 if (rt->fib6_nsiblings)
540 rt = list_last_entry(&rt->fib6_siblings,
541 struct fib6_info,
542 fib6_siblings);
543 }
544 w->leaf = NULL;
545 return 0;
546 }
547
fib6_dump_end(struct netlink_callback * cb)548 static void fib6_dump_end(struct netlink_callback *cb)
549 {
550 struct net *net = sock_net(cb->skb->sk);
551 struct fib6_walker *w = (void *)cb->args[2];
552
553 if (w) {
554 if (cb->args[4]) {
555 cb->args[4] = 0;
556 fib6_walker_unlink(net, w);
557 }
558 cb->args[2] = 0;
559 kfree(w);
560 }
561 cb->done = (void *)cb->args[3];
562 cb->args[1] = 3;
563 }
564
fib6_dump_done(struct netlink_callback * cb)565 static int fib6_dump_done(struct netlink_callback *cb)
566 {
567 fib6_dump_end(cb);
568 return cb->done ? cb->done(cb) : 0;
569 }
570
fib6_dump_table(struct fib6_table * table,struct sk_buff * skb,struct netlink_callback * cb)571 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
572 struct netlink_callback *cb)
573 {
574 struct net *net = sock_net(skb->sk);
575 struct fib6_walker *w;
576 int res;
577
578 w = (void *)cb->args[2];
579 w->root = &table->tb6_root;
580
581 if (cb->args[4] == 0) {
582 w->count = 0;
583 w->skip = 0;
584 w->skip_in_node = 0;
585
586 spin_lock_bh(&table->tb6_lock);
587 res = fib6_walk(net, w);
588 spin_unlock_bh(&table->tb6_lock);
589 if (res > 0) {
590 cb->args[4] = 1;
591 cb->args[5] = w->root->fn_sernum;
592 }
593 } else {
594 if (cb->args[5] != w->root->fn_sernum) {
595 /* Begin at the root if the tree changed */
596 cb->args[5] = w->root->fn_sernum;
597 w->state = FWS_INIT;
598 w->node = w->root;
599 w->skip = w->count;
600 w->skip_in_node = 0;
601 } else
602 w->skip = 0;
603
604 spin_lock_bh(&table->tb6_lock);
605 res = fib6_walk_continue(w);
606 spin_unlock_bh(&table->tb6_lock);
607 if (res <= 0) {
608 fib6_walker_unlink(net, w);
609 cb->args[4] = 0;
610 }
611 }
612
613 return res;
614 }
615
inet6_dump_fib(struct sk_buff * skb,struct netlink_callback * cb)616 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
617 {
618 struct rt6_rtnl_dump_arg arg = { .filter.dump_exceptions = true,
619 .filter.dump_routes = true };
620 const struct nlmsghdr *nlh = cb->nlh;
621 struct net *net = sock_net(skb->sk);
622 unsigned int h, s_h;
623 unsigned int e = 0, s_e;
624 struct fib6_walker *w;
625 struct fib6_table *tb;
626 struct hlist_head *head;
627 int res = 0;
628
629 if (cb->strict_check) {
630 int err;
631
632 err = ip_valid_fib_dump_req(net, nlh, &arg.filter, cb);
633 if (err < 0)
634 return err;
635 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
636 struct rtmsg *rtm = nlmsg_data(nlh);
637
638 if (rtm->rtm_flags & RTM_F_PREFIX)
639 arg.filter.flags = RTM_F_PREFIX;
640 }
641
642 w = (void *)cb->args[2];
643 if (!w) {
644 /* New dump:
645 *
646 * 1. hook callback destructor.
647 */
648 cb->args[3] = (long)cb->done;
649 cb->done = fib6_dump_done;
650
651 /*
652 * 2. allocate and initialize walker.
653 */
654 w = kzalloc(sizeof(*w), GFP_ATOMIC);
655 if (!w)
656 return -ENOMEM;
657 w->func = fib6_dump_node;
658 cb->args[2] = (long)w;
659 }
660
661 arg.skb = skb;
662 arg.cb = cb;
663 arg.net = net;
664 w->args = &arg;
665
666 if (arg.filter.table_id) {
667 tb = fib6_get_table(net, arg.filter.table_id);
668 if (!tb) {
669 if (rtnl_msg_family(cb->nlh) != PF_INET6)
670 goto out;
671
672 NL_SET_ERR_MSG_MOD(cb->extack, "FIB table does not exist");
673 return -ENOENT;
674 }
675
676 if (!cb->args[0]) {
677 res = fib6_dump_table(tb, skb, cb);
678 if (!res)
679 cb->args[0] = 1;
680 }
681 goto out;
682 }
683
684 s_h = cb->args[0];
685 s_e = cb->args[1];
686
687 rcu_read_lock();
688 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
689 e = 0;
690 head = &net->ipv6.fib_table_hash[h];
691 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
692 if (e < s_e)
693 goto next;
694 res = fib6_dump_table(tb, skb, cb);
695 if (res != 0)
696 goto out_unlock;
697 next:
698 e++;
699 }
700 }
701 out_unlock:
702 rcu_read_unlock();
703 cb->args[1] = e;
704 cb->args[0] = h;
705 out:
706 res = res < 0 ? res : skb->len;
707 if (res <= 0)
708 fib6_dump_end(cb);
709 return res;
710 }
711
fib6_metric_set(struct fib6_info * f6i,int metric,u32 val)712 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val)
713 {
714 if (!f6i)
715 return;
716
717 if (f6i->fib6_metrics == &dst_default_metrics) {
718 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC);
719
720 if (!p)
721 return;
722
723 refcount_set(&p->refcnt, 1);
724 f6i->fib6_metrics = p;
725 }
726
727 f6i->fib6_metrics->metrics[metric - 1] = val;
728 }
729
730 /*
731 * Routing Table
732 *
733 * return the appropriate node for a routing tree "add" operation
734 * by either creating and inserting or by returning an existing
735 * node.
736 */
737
fib6_add_1(struct net * net,struct fib6_table * table,struct fib6_node * root,struct in6_addr * addr,int plen,int offset,int allow_create,int replace_required,struct netlink_ext_ack * extack)738 static struct fib6_node *fib6_add_1(struct net *net,
739 struct fib6_table *table,
740 struct fib6_node *root,
741 struct in6_addr *addr, int plen,
742 int offset, int allow_create,
743 int replace_required,
744 struct netlink_ext_ack *extack)
745 {
746 struct fib6_node *fn, *in, *ln;
747 struct fib6_node *pn = NULL;
748 struct rt6key *key;
749 int bit;
750 __be32 dir = 0;
751
752 RT6_TRACE("fib6_add_1\n");
753
754 /* insert node in tree */
755
756 fn = root;
757
758 do {
759 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
760 lockdep_is_held(&table->tb6_lock));
761 key = (struct rt6key *)((u8 *)leaf + offset);
762
763 /*
764 * Prefix match
765 */
766 if (plen < fn->fn_bit ||
767 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
768 if (!allow_create) {
769 if (replace_required) {
770 NL_SET_ERR_MSG(extack,
771 "Can not replace route - no match found");
772 pr_warn("Can't replace route, no match found\n");
773 return ERR_PTR(-ENOENT);
774 }
775 pr_warn("NLM_F_CREATE should be set when creating new route\n");
776 }
777 goto insert_above;
778 }
779
780 /*
781 * Exact match ?
782 */
783
784 if (plen == fn->fn_bit) {
785 /* clean up an intermediate node */
786 if (!(fn->fn_flags & RTN_RTINFO)) {
787 RCU_INIT_POINTER(fn->leaf, NULL);
788 fib6_info_release(leaf);
789 /* remove null_entry in the root node */
790 } else if (fn->fn_flags & RTN_TL_ROOT &&
791 rcu_access_pointer(fn->leaf) ==
792 net->ipv6.fib6_null_entry) {
793 RCU_INIT_POINTER(fn->leaf, NULL);
794 }
795
796 return fn;
797 }
798
799 /*
800 * We have more bits to go
801 */
802
803 /* Try to walk down on tree. */
804 dir = addr_bit_set(addr, fn->fn_bit);
805 pn = fn;
806 fn = dir ?
807 rcu_dereference_protected(fn->right,
808 lockdep_is_held(&table->tb6_lock)) :
809 rcu_dereference_protected(fn->left,
810 lockdep_is_held(&table->tb6_lock));
811 } while (fn);
812
813 if (!allow_create) {
814 /* We should not create new node because
815 * NLM_F_REPLACE was specified without NLM_F_CREATE
816 * I assume it is safe to require NLM_F_CREATE when
817 * REPLACE flag is used! Later we may want to remove the
818 * check for replace_required, because according
819 * to netlink specification, NLM_F_CREATE
820 * MUST be specified if new route is created.
821 * That would keep IPv6 consistent with IPv4
822 */
823 if (replace_required) {
824 NL_SET_ERR_MSG(extack,
825 "Can not replace route - no match found");
826 pr_warn("Can't replace route, no match found\n");
827 return ERR_PTR(-ENOENT);
828 }
829 pr_warn("NLM_F_CREATE should be set when creating new route\n");
830 }
831 /*
832 * We walked to the bottom of tree.
833 * Create new leaf node without children.
834 */
835
836 ln = node_alloc(net);
837
838 if (!ln)
839 return ERR_PTR(-ENOMEM);
840 ln->fn_bit = plen;
841 RCU_INIT_POINTER(ln->parent, pn);
842
843 if (dir)
844 rcu_assign_pointer(pn->right, ln);
845 else
846 rcu_assign_pointer(pn->left, ln);
847
848 return ln;
849
850
851 insert_above:
852 /*
853 * split since we don't have a common prefix anymore or
854 * we have a less significant route.
855 * we've to insert an intermediate node on the list
856 * this new node will point to the one we need to create
857 * and the current
858 */
859
860 pn = rcu_dereference_protected(fn->parent,
861 lockdep_is_held(&table->tb6_lock));
862
863 /* find 1st bit in difference between the 2 addrs.
864
865 See comment in __ipv6_addr_diff: bit may be an invalid value,
866 but if it is >= plen, the value is ignored in any case.
867 */
868
869 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr));
870
871 /*
872 * (intermediate)[in]
873 * / \
874 * (new leaf node)[ln] (old node)[fn]
875 */
876 if (plen > bit) {
877 in = node_alloc(net);
878 ln = node_alloc(net);
879
880 if (!in || !ln) {
881 if (in)
882 node_free_immediate(net, in);
883 if (ln)
884 node_free_immediate(net, ln);
885 return ERR_PTR(-ENOMEM);
886 }
887
888 /*
889 * new intermediate node.
890 * RTN_RTINFO will
891 * be off since that an address that chooses one of
892 * the branches would not match less specific routes
893 * in the other branch
894 */
895
896 in->fn_bit = bit;
897
898 RCU_INIT_POINTER(in->parent, pn);
899 in->leaf = fn->leaf;
900 fib6_info_hold(rcu_dereference_protected(in->leaf,
901 lockdep_is_held(&table->tb6_lock)));
902
903 /* update parent pointer */
904 if (dir)
905 rcu_assign_pointer(pn->right, in);
906 else
907 rcu_assign_pointer(pn->left, in);
908
909 ln->fn_bit = plen;
910
911 RCU_INIT_POINTER(ln->parent, in);
912 rcu_assign_pointer(fn->parent, in);
913
914 if (addr_bit_set(addr, bit)) {
915 rcu_assign_pointer(in->right, ln);
916 rcu_assign_pointer(in->left, fn);
917 } else {
918 rcu_assign_pointer(in->left, ln);
919 rcu_assign_pointer(in->right, fn);
920 }
921 } else { /* plen <= bit */
922
923 /*
924 * (new leaf node)[ln]
925 * / \
926 * (old node)[fn] NULL
927 */
928
929 ln = node_alloc(net);
930
931 if (!ln)
932 return ERR_PTR(-ENOMEM);
933
934 ln->fn_bit = plen;
935
936 RCU_INIT_POINTER(ln->parent, pn);
937
938 if (addr_bit_set(&key->addr, plen))
939 RCU_INIT_POINTER(ln->right, fn);
940 else
941 RCU_INIT_POINTER(ln->left, fn);
942
943 rcu_assign_pointer(fn->parent, ln);
944
945 if (dir)
946 rcu_assign_pointer(pn->right, ln);
947 else
948 rcu_assign_pointer(pn->left, ln);
949 }
950 return ln;
951 }
952
__fib6_drop_pcpu_from(struct fib6_nh * fib6_nh,const struct fib6_info * match,const struct fib6_table * table)953 static void __fib6_drop_pcpu_from(struct fib6_nh *fib6_nh,
954 const struct fib6_info *match,
955 const struct fib6_table *table)
956 {
957 int cpu;
958
959 if (!fib6_nh->rt6i_pcpu)
960 return;
961
962 /* release the reference to this fib entry from
963 * all of its cached pcpu routes
964 */
965 for_each_possible_cpu(cpu) {
966 struct rt6_info **ppcpu_rt;
967 struct rt6_info *pcpu_rt;
968
969 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
970 pcpu_rt = *ppcpu_rt;
971
972 /* only dropping the 'from' reference if the cached route
973 * is using 'match'. The cached pcpu_rt->from only changes
974 * from a fib6_info to NULL (ip6_dst_destroy); it can never
975 * change from one fib6_info reference to another
976 */
977 if (pcpu_rt && rcu_access_pointer(pcpu_rt->from) == match) {
978 struct fib6_info *from;
979
980 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
981 fib6_info_release(from);
982 }
983 }
984 }
985
986 struct fib6_nh_pcpu_arg {
987 struct fib6_info *from;
988 const struct fib6_table *table;
989 };
990
fib6_nh_drop_pcpu_from(struct fib6_nh * nh,void * _arg)991 static int fib6_nh_drop_pcpu_from(struct fib6_nh *nh, void *_arg)
992 {
993 struct fib6_nh_pcpu_arg *arg = _arg;
994
995 __fib6_drop_pcpu_from(nh, arg->from, arg->table);
996 return 0;
997 }
998
fib6_drop_pcpu_from(struct fib6_info * f6i,const struct fib6_table * table)999 static void fib6_drop_pcpu_from(struct fib6_info *f6i,
1000 const struct fib6_table *table)
1001 {
1002 /* Make sure rt6_make_pcpu_route() wont add other percpu routes
1003 * while we are cleaning them here.
1004 */
1005 f6i->fib6_destroying = 1;
1006 mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */
1007
1008 if (f6i->nh) {
1009 struct fib6_nh_pcpu_arg arg = {
1010 .from = f6i,
1011 .table = table
1012 };
1013
1014 nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_drop_pcpu_from,
1015 &arg);
1016 } else {
1017 struct fib6_nh *fib6_nh;
1018
1019 fib6_nh = f6i->fib6_nh;
1020 __fib6_drop_pcpu_from(fib6_nh, f6i, table);
1021 }
1022 }
1023
fib6_purge_rt(struct fib6_info * rt,struct fib6_node * fn,struct net * net)1024 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,
1025 struct net *net)
1026 {
1027 struct fib6_table *table = rt->fib6_table;
1028
1029 /* Flush all cached dst in exception table */
1030 rt6_flush_exceptions(rt);
1031 fib6_drop_pcpu_from(rt, table);
1032
1033 if (rt->nh && !list_empty(&rt->nh_list))
1034 list_del_init(&rt->nh_list);
1035
1036 if (refcount_read(&rt->fib6_ref) != 1) {
1037 /* This route is used as dummy address holder in some split
1038 * nodes. It is not leaked, but it still holds other resources,
1039 * which must be released in time. So, scan ascendant nodes
1040 * and replace dummy references to this route with references
1041 * to still alive ones.
1042 */
1043 while (fn) {
1044 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
1045 lockdep_is_held(&table->tb6_lock));
1046 struct fib6_info *new_leaf;
1047 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) {
1048 new_leaf = fib6_find_prefix(net, table, fn);
1049 fib6_info_hold(new_leaf);
1050
1051 rcu_assign_pointer(fn->leaf, new_leaf);
1052 fib6_info_release(rt);
1053 }
1054 fn = rcu_dereference_protected(fn->parent,
1055 lockdep_is_held(&table->tb6_lock));
1056 }
1057 }
1058 }
1059
1060 /*
1061 * Insert routing information in a node.
1062 */
1063
fib6_add_rt2node(struct fib6_node * fn,struct fib6_info * rt,struct nl_info * info,struct netlink_ext_ack * extack)1064 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
1065 struct nl_info *info,
1066 struct netlink_ext_ack *extack)
1067 {
1068 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
1069 lockdep_is_held(&rt->fib6_table->tb6_lock));
1070 struct fib6_info *iter = NULL;
1071 struct fib6_info __rcu **ins;
1072 struct fib6_info __rcu **fallback_ins = NULL;
1073 int replace = (info->nlh &&
1074 (info->nlh->nlmsg_flags & NLM_F_REPLACE));
1075 int add = (!info->nlh ||
1076 (info->nlh->nlmsg_flags & NLM_F_CREATE));
1077 int found = 0;
1078 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
1079 bool notify_sibling_rt = false;
1080 u16 nlflags = NLM_F_EXCL;
1081 int err;
1082
1083 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND))
1084 nlflags |= NLM_F_APPEND;
1085
1086 ins = &fn->leaf;
1087
1088 for (iter = leaf; iter;
1089 iter = rcu_dereference_protected(iter->fib6_next,
1090 lockdep_is_held(&rt->fib6_table->tb6_lock))) {
1091 /*
1092 * Search for duplicates
1093 */
1094
1095 if (iter->fib6_metric == rt->fib6_metric) {
1096 /*
1097 * Same priority level
1098 */
1099 if (info->nlh &&
1100 (info->nlh->nlmsg_flags & NLM_F_EXCL))
1101 return -EEXIST;
1102
1103 nlflags &= ~NLM_F_EXCL;
1104 if (replace) {
1105 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) {
1106 found++;
1107 break;
1108 }
1109 fallback_ins = fallback_ins ?: ins;
1110 goto next_iter;
1111 }
1112
1113 if (rt6_duplicate_nexthop(iter, rt)) {
1114 if (rt->fib6_nsiblings)
1115 rt->fib6_nsiblings = 0;
1116 if (!(iter->fib6_flags & RTF_EXPIRES))
1117 return -EEXIST;
1118 if (!(rt->fib6_flags & RTF_EXPIRES))
1119 fib6_clean_expires(iter);
1120 else
1121 fib6_set_expires(iter, rt->expires);
1122
1123 if (rt->fib6_pmtu)
1124 fib6_metric_set(iter, RTAX_MTU,
1125 rt->fib6_pmtu);
1126 return -EEXIST;
1127 }
1128 /* If we have the same destination and the same metric,
1129 * but not the same gateway, then the route we try to
1130 * add is sibling to this route, increment our counter
1131 * of siblings, and later we will add our route to the
1132 * list.
1133 * Only static routes (which don't have flag
1134 * RTF_EXPIRES) are used for ECMPv6.
1135 *
1136 * To avoid long list, we only had siblings if the
1137 * route have a gateway.
1138 */
1139 if (rt_can_ecmp &&
1140 rt6_qualify_for_ecmp(iter))
1141 rt->fib6_nsiblings++;
1142 }
1143
1144 if (iter->fib6_metric > rt->fib6_metric)
1145 break;
1146
1147 next_iter:
1148 ins = &iter->fib6_next;
1149 }
1150
1151 if (fallback_ins && !found) {
1152 /* No matching route with same ecmp-able-ness found, replace
1153 * first matching route
1154 */
1155 ins = fallback_ins;
1156 iter = rcu_dereference_protected(*ins,
1157 lockdep_is_held(&rt->fib6_table->tb6_lock));
1158 found++;
1159 }
1160
1161 /* Reset round-robin state, if necessary */
1162 if (ins == &fn->leaf)
1163 fn->rr_ptr = NULL;
1164
1165 /* Link this route to others same route. */
1166 if (rt->fib6_nsiblings) {
1167 unsigned int fib6_nsiblings;
1168 struct fib6_info *sibling, *temp_sibling;
1169
1170 /* Find the first route that have the same metric */
1171 sibling = leaf;
1172 notify_sibling_rt = true;
1173 while (sibling) {
1174 if (sibling->fib6_metric == rt->fib6_metric &&
1175 rt6_qualify_for_ecmp(sibling)) {
1176 list_add_tail(&rt->fib6_siblings,
1177 &sibling->fib6_siblings);
1178 break;
1179 }
1180 sibling = rcu_dereference_protected(sibling->fib6_next,
1181 lockdep_is_held(&rt->fib6_table->tb6_lock));
1182 notify_sibling_rt = false;
1183 }
1184 /* For each sibling in the list, increment the counter of
1185 * siblings. BUG() if counters does not match, list of siblings
1186 * is broken!
1187 */
1188 fib6_nsiblings = 0;
1189 list_for_each_entry_safe(sibling, temp_sibling,
1190 &rt->fib6_siblings, fib6_siblings) {
1191 sibling->fib6_nsiblings++;
1192 BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings);
1193 fib6_nsiblings++;
1194 }
1195 BUG_ON(fib6_nsiblings != rt->fib6_nsiblings);
1196 rt6_multipath_rebalance(temp_sibling);
1197 }
1198
1199 /*
1200 * insert node
1201 */
1202 if (!replace) {
1203 if (!add)
1204 pr_warn("NLM_F_CREATE should be set when creating new route\n");
1205
1206 add:
1207 nlflags |= NLM_F_CREATE;
1208
1209 /* The route should only be notified if it is the first
1210 * route in the node or if it is added as a sibling
1211 * route to the first route in the node.
1212 */
1213 if (!info->skip_notify_kernel &&
1214 (notify_sibling_rt || ins == &fn->leaf)) {
1215 enum fib_event_type fib_event;
1216
1217 if (notify_sibling_rt)
1218 fib_event = FIB_EVENT_ENTRY_APPEND;
1219 else
1220 fib_event = FIB_EVENT_ENTRY_REPLACE;
1221 err = call_fib6_entry_notifiers(info->nl_net,
1222 fib_event, rt,
1223 extack);
1224 if (err) {
1225 struct fib6_info *sibling, *next_sibling;
1226
1227 /* If the route has siblings, then it first
1228 * needs to be unlinked from them.
1229 */
1230 if (!rt->fib6_nsiblings)
1231 return err;
1232
1233 list_for_each_entry_safe(sibling, next_sibling,
1234 &rt->fib6_siblings,
1235 fib6_siblings)
1236 sibling->fib6_nsiblings--;
1237 rt->fib6_nsiblings = 0;
1238 list_del_init(&rt->fib6_siblings);
1239 rt6_multipath_rebalance(next_sibling);
1240 return err;
1241 }
1242 }
1243
1244 rcu_assign_pointer(rt->fib6_next, iter);
1245 fib6_info_hold(rt);
1246 rcu_assign_pointer(rt->fib6_node, fn);
1247 rcu_assign_pointer(*ins, rt);
1248 if (!info->skip_notify)
1249 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
1250 info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
1251
1252 if (!(fn->fn_flags & RTN_RTINFO)) {
1253 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
1254 fn->fn_flags |= RTN_RTINFO;
1255 }
1256
1257 } else {
1258 int nsiblings;
1259
1260 if (!found) {
1261 if (add)
1262 goto add;
1263 pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
1264 return -ENOENT;
1265 }
1266
1267 if (!info->skip_notify_kernel && ins == &fn->leaf) {
1268 err = call_fib6_entry_notifiers(info->nl_net,
1269 FIB_EVENT_ENTRY_REPLACE,
1270 rt, extack);
1271 if (err)
1272 return err;
1273 }
1274
1275 fib6_info_hold(rt);
1276 rcu_assign_pointer(rt->fib6_node, fn);
1277 rt->fib6_next = iter->fib6_next;
1278 rcu_assign_pointer(*ins, rt);
1279 if (!info->skip_notify)
1280 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE);
1281 if (!(fn->fn_flags & RTN_RTINFO)) {
1282 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
1283 fn->fn_flags |= RTN_RTINFO;
1284 }
1285 nsiblings = iter->fib6_nsiblings;
1286 iter->fib6_node = NULL;
1287 fib6_purge_rt(iter, fn, info->nl_net);
1288 if (rcu_access_pointer(fn->rr_ptr) == iter)
1289 fn->rr_ptr = NULL;
1290 fib6_info_release(iter);
1291
1292 if (nsiblings) {
1293 /* Replacing an ECMP route, remove all siblings */
1294 ins = &rt->fib6_next;
1295 iter = rcu_dereference_protected(*ins,
1296 lockdep_is_held(&rt->fib6_table->tb6_lock));
1297 while (iter) {
1298 if (iter->fib6_metric > rt->fib6_metric)
1299 break;
1300 if (rt6_qualify_for_ecmp(iter)) {
1301 *ins = iter->fib6_next;
1302 iter->fib6_node = NULL;
1303 fib6_purge_rt(iter, fn, info->nl_net);
1304 if (rcu_access_pointer(fn->rr_ptr) == iter)
1305 fn->rr_ptr = NULL;
1306 fib6_info_release(iter);
1307 nsiblings--;
1308 info->nl_net->ipv6.rt6_stats->fib_rt_entries--;
1309 } else {
1310 ins = &iter->fib6_next;
1311 }
1312 iter = rcu_dereference_protected(*ins,
1313 lockdep_is_held(&rt->fib6_table->tb6_lock));
1314 }
1315 WARN_ON(nsiblings != 0);
1316 }
1317 }
1318
1319 return 0;
1320 }
1321
fib6_start_gc(struct net * net,struct fib6_info * rt)1322 static void fib6_start_gc(struct net *net, struct fib6_info *rt)
1323 {
1324 if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
1325 (rt->fib6_flags & RTF_EXPIRES))
1326 mod_timer(&net->ipv6.ip6_fib_timer,
1327 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
1328 }
1329
fib6_force_start_gc(struct net * net)1330 void fib6_force_start_gc(struct net *net)
1331 {
1332 if (!timer_pending(&net->ipv6.ip6_fib_timer))
1333 mod_timer(&net->ipv6.ip6_fib_timer,
1334 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
1335 }
1336
__fib6_update_sernum_upto_root(struct fib6_info * rt,int sernum)1337 static void __fib6_update_sernum_upto_root(struct fib6_info *rt,
1338 int sernum)
1339 {
1340 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node,
1341 lockdep_is_held(&rt->fib6_table->tb6_lock));
1342
1343 /* paired with smp_rmb() in rt6_get_cookie_safe() */
1344 smp_wmb();
1345 while (fn) {
1346 fn->fn_sernum = sernum;
1347 fn = rcu_dereference_protected(fn->parent,
1348 lockdep_is_held(&rt->fib6_table->tb6_lock));
1349 }
1350 }
1351
fib6_update_sernum_upto_root(struct net * net,struct fib6_info * rt)1352 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt)
1353 {
1354 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net));
1355 }
1356
1357 /* allow ipv4 to update sernum via ipv6_stub */
fib6_update_sernum_stub(struct net * net,struct fib6_info * f6i)1358 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i)
1359 {
1360 spin_lock_bh(&f6i->fib6_table->tb6_lock);
1361 fib6_update_sernum_upto_root(net, f6i);
1362 spin_unlock_bh(&f6i->fib6_table->tb6_lock);
1363 }
1364
1365 /*
1366 * Add routing information to the routing tree.
1367 * <destination addr>/<source addr>
1368 * with source addr info in sub-trees
1369 * Need to own table->tb6_lock
1370 */
1371
fib6_add(struct fib6_node * root,struct fib6_info * rt,struct nl_info * info,struct netlink_ext_ack * extack)1372 int fib6_add(struct fib6_node *root, struct fib6_info *rt,
1373 struct nl_info *info, struct netlink_ext_ack *extack)
1374 {
1375 struct fib6_table *table = rt->fib6_table;
1376 struct fib6_node *fn, *pn = NULL;
1377 int err = -ENOMEM;
1378 int allow_create = 1;
1379 int replace_required = 0;
1380 int sernum = fib6_new_sernum(info->nl_net);
1381
1382 if (info->nlh) {
1383 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
1384 allow_create = 0;
1385 if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
1386 replace_required = 1;
1387 }
1388 if (!allow_create && !replace_required)
1389 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
1390
1391 fn = fib6_add_1(info->nl_net, table, root,
1392 &rt->fib6_dst.addr, rt->fib6_dst.plen,
1393 offsetof(struct fib6_info, fib6_dst), allow_create,
1394 replace_required, extack);
1395 if (IS_ERR(fn)) {
1396 err = PTR_ERR(fn);
1397 fn = NULL;
1398 goto out;
1399 }
1400
1401 pn = fn;
1402
1403 #ifdef CONFIG_IPV6_SUBTREES
1404 if (rt->fib6_src.plen) {
1405 struct fib6_node *sn;
1406
1407 if (!rcu_access_pointer(fn->subtree)) {
1408 struct fib6_node *sfn;
1409
1410 /*
1411 * Create subtree.
1412 *
1413 * fn[main tree]
1414 * |
1415 * sfn[subtree root]
1416 * \
1417 * sn[new leaf node]
1418 */
1419
1420 /* Create subtree root node */
1421 sfn = node_alloc(info->nl_net);
1422 if (!sfn)
1423 goto failure;
1424
1425 fib6_info_hold(info->nl_net->ipv6.fib6_null_entry);
1426 rcu_assign_pointer(sfn->leaf,
1427 info->nl_net->ipv6.fib6_null_entry);
1428 sfn->fn_flags = RTN_ROOT;
1429
1430 /* Now add the first leaf node to new subtree */
1431
1432 sn = fib6_add_1(info->nl_net, table, sfn,
1433 &rt->fib6_src.addr, rt->fib6_src.plen,
1434 offsetof(struct fib6_info, fib6_src),
1435 allow_create, replace_required, extack);
1436
1437 if (IS_ERR(sn)) {
1438 /* If it is failed, discard just allocated
1439 root, and then (in failure) stale node
1440 in main tree.
1441 */
1442 node_free_immediate(info->nl_net, sfn);
1443 err = PTR_ERR(sn);
1444 goto failure;
1445 }
1446
1447 /* Now link new subtree to main tree */
1448 rcu_assign_pointer(sfn->parent, fn);
1449 rcu_assign_pointer(fn->subtree, sfn);
1450 } else {
1451 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn),
1452 &rt->fib6_src.addr, rt->fib6_src.plen,
1453 offsetof(struct fib6_info, fib6_src),
1454 allow_create, replace_required, extack);
1455
1456 if (IS_ERR(sn)) {
1457 err = PTR_ERR(sn);
1458 goto failure;
1459 }
1460 }
1461
1462 if (!rcu_access_pointer(fn->leaf)) {
1463 if (fn->fn_flags & RTN_TL_ROOT) {
1464 /* put back null_entry for root node */
1465 rcu_assign_pointer(fn->leaf,
1466 info->nl_net->ipv6.fib6_null_entry);
1467 } else {
1468 fib6_info_hold(rt);
1469 rcu_assign_pointer(fn->leaf, rt);
1470 }
1471 }
1472 fn = sn;
1473 }
1474 #endif
1475
1476 err = fib6_add_rt2node(fn, rt, info, extack);
1477 if (!err) {
1478 if (rt->nh)
1479 list_add(&rt->nh_list, &rt->nh->f6i_list);
1480 __fib6_update_sernum_upto_root(rt, sernum);
1481 fib6_start_gc(info->nl_net, rt);
1482 }
1483
1484 out:
1485 if (err) {
1486 #ifdef CONFIG_IPV6_SUBTREES
1487 /*
1488 * If fib6_add_1 has cleared the old leaf pointer in the
1489 * super-tree leaf node we have to find a new one for it.
1490 */
1491 if (pn != fn) {
1492 struct fib6_info *pn_leaf =
1493 rcu_dereference_protected(pn->leaf,
1494 lockdep_is_held(&table->tb6_lock));
1495 if (pn_leaf == rt) {
1496 pn_leaf = NULL;
1497 RCU_INIT_POINTER(pn->leaf, NULL);
1498 fib6_info_release(rt);
1499 }
1500 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) {
1501 pn_leaf = fib6_find_prefix(info->nl_net, table,
1502 pn);
1503 #if RT6_DEBUG >= 2
1504 if (!pn_leaf) {
1505 WARN_ON(!pn_leaf);
1506 pn_leaf =
1507 info->nl_net->ipv6.fib6_null_entry;
1508 }
1509 #endif
1510 fib6_info_hold(pn_leaf);
1511 rcu_assign_pointer(pn->leaf, pn_leaf);
1512 }
1513 }
1514 #endif
1515 goto failure;
1516 } else if (fib6_requires_src(rt)) {
1517 fib6_routes_require_src_inc(info->nl_net);
1518 }
1519 return err;
1520
1521 failure:
1522 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if:
1523 * 1. fn is an intermediate node and we failed to add the new
1524 * route to it in both subtree creation failure and fib6_add_rt2node()
1525 * failure case.
1526 * 2. fn is the root node in the table and we fail to add the first
1527 * default route to it.
1528 */
1529 if (fn &&
1530 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) ||
1531 (fn->fn_flags & RTN_TL_ROOT &&
1532 !rcu_access_pointer(fn->leaf))))
1533 fib6_repair_tree(info->nl_net, table, fn);
1534 return err;
1535 }
1536
1537 /*
1538 * Routing tree lookup
1539 *
1540 */
1541
1542 struct lookup_args {
1543 int offset; /* key offset on fib6_info */
1544 const struct in6_addr *addr; /* search key */
1545 };
1546
fib6_node_lookup_1(struct fib6_node * root,struct lookup_args * args)1547 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root,
1548 struct lookup_args *args)
1549 {
1550 struct fib6_node *fn;
1551 __be32 dir;
1552
1553 if (unlikely(args->offset == 0))
1554 return NULL;
1555
1556 /*
1557 * Descend on a tree
1558 */
1559
1560 fn = root;
1561
1562 for (;;) {
1563 struct fib6_node *next;
1564
1565 dir = addr_bit_set(args->addr, fn->fn_bit);
1566
1567 next = dir ? rcu_dereference(fn->right) :
1568 rcu_dereference(fn->left);
1569
1570 if (next) {
1571 fn = next;
1572 continue;
1573 }
1574 break;
1575 }
1576
1577 while (fn) {
1578 struct fib6_node *subtree = FIB6_SUBTREE(fn);
1579
1580 if (subtree || fn->fn_flags & RTN_RTINFO) {
1581 struct fib6_info *leaf = rcu_dereference(fn->leaf);
1582 struct rt6key *key;
1583
1584 if (!leaf)
1585 goto backtrack;
1586
1587 key = (struct rt6key *) ((u8 *)leaf + args->offset);
1588
1589 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
1590 #ifdef CONFIG_IPV6_SUBTREES
1591 if (subtree) {
1592 struct fib6_node *sfn;
1593 sfn = fib6_node_lookup_1(subtree,
1594 args + 1);
1595 if (!sfn)
1596 goto backtrack;
1597 fn = sfn;
1598 }
1599 #endif
1600 if (fn->fn_flags & RTN_RTINFO)
1601 return fn;
1602 }
1603 }
1604 backtrack:
1605 if (fn->fn_flags & RTN_ROOT)
1606 break;
1607
1608 fn = rcu_dereference(fn->parent);
1609 }
1610
1611 return NULL;
1612 }
1613
1614 /* called with rcu_read_lock() held
1615 */
fib6_node_lookup(struct fib6_node * root,const struct in6_addr * daddr,const struct in6_addr * saddr)1616 struct fib6_node *fib6_node_lookup(struct fib6_node *root,
1617 const struct in6_addr *daddr,
1618 const struct in6_addr *saddr)
1619 {
1620 struct fib6_node *fn;
1621 struct lookup_args args[] = {
1622 {
1623 .offset = offsetof(struct fib6_info, fib6_dst),
1624 .addr = daddr,
1625 },
1626 #ifdef CONFIG_IPV6_SUBTREES
1627 {
1628 .offset = offsetof(struct fib6_info, fib6_src),
1629 .addr = saddr,
1630 },
1631 #endif
1632 {
1633 .offset = 0, /* sentinel */
1634 }
1635 };
1636
1637 fn = fib6_node_lookup_1(root, daddr ? args : args + 1);
1638 if (!fn || fn->fn_flags & RTN_TL_ROOT)
1639 fn = root;
1640
1641 return fn;
1642 }
1643
1644 /*
1645 * Get node with specified destination prefix (and source prefix,
1646 * if subtrees are used)
1647 * exact_match == true means we try to find fn with exact match of
1648 * the passed in prefix addr
1649 * exact_match == false means we try to find fn with longest prefix
1650 * match of the passed in prefix addr. This is useful for finding fn
1651 * for cached route as it will be stored in the exception table under
1652 * the node with longest prefix length.
1653 */
1654
1655
fib6_locate_1(struct fib6_node * root,const struct in6_addr * addr,int plen,int offset,bool exact_match)1656 static struct fib6_node *fib6_locate_1(struct fib6_node *root,
1657 const struct in6_addr *addr,
1658 int plen, int offset,
1659 bool exact_match)
1660 {
1661 struct fib6_node *fn, *prev = NULL;
1662
1663 for (fn = root; fn ; ) {
1664 struct fib6_info *leaf = rcu_dereference(fn->leaf);
1665 struct rt6key *key;
1666
1667 /* This node is being deleted */
1668 if (!leaf) {
1669 if (plen <= fn->fn_bit)
1670 goto out;
1671 else
1672 goto next;
1673 }
1674
1675 key = (struct rt6key *)((u8 *)leaf + offset);
1676
1677 /*
1678 * Prefix match
1679 */
1680 if (plen < fn->fn_bit ||
1681 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
1682 goto out;
1683
1684 if (plen == fn->fn_bit)
1685 return fn;
1686
1687 if (fn->fn_flags & RTN_RTINFO)
1688 prev = fn;
1689
1690 next:
1691 /*
1692 * We have more bits to go
1693 */
1694 if (addr_bit_set(addr, fn->fn_bit))
1695 fn = rcu_dereference(fn->right);
1696 else
1697 fn = rcu_dereference(fn->left);
1698 }
1699 out:
1700 if (exact_match)
1701 return NULL;
1702 else
1703 return prev;
1704 }
1705
fib6_locate(struct fib6_node * root,const struct in6_addr * daddr,int dst_len,const struct in6_addr * saddr,int src_len,bool exact_match)1706 struct fib6_node *fib6_locate(struct fib6_node *root,
1707 const struct in6_addr *daddr, int dst_len,
1708 const struct in6_addr *saddr, int src_len,
1709 bool exact_match)
1710 {
1711 struct fib6_node *fn;
1712
1713 fn = fib6_locate_1(root, daddr, dst_len,
1714 offsetof(struct fib6_info, fib6_dst),
1715 exact_match);
1716
1717 #ifdef CONFIG_IPV6_SUBTREES
1718 if (src_len) {
1719 WARN_ON(saddr == NULL);
1720 if (fn) {
1721 struct fib6_node *subtree = FIB6_SUBTREE(fn);
1722
1723 if (subtree) {
1724 fn = fib6_locate_1(subtree, saddr, src_len,
1725 offsetof(struct fib6_info, fib6_src),
1726 exact_match);
1727 }
1728 }
1729 }
1730 #endif
1731
1732 if (fn && fn->fn_flags & RTN_RTINFO)
1733 return fn;
1734
1735 return NULL;
1736 }
1737
1738
1739 /*
1740 * Deletion
1741 *
1742 */
1743
fib6_find_prefix(struct net * net,struct fib6_table * table,struct fib6_node * fn)1744 static struct fib6_info *fib6_find_prefix(struct net *net,
1745 struct fib6_table *table,
1746 struct fib6_node *fn)
1747 {
1748 struct fib6_node *child_left, *child_right;
1749
1750 if (fn->fn_flags & RTN_ROOT)
1751 return net->ipv6.fib6_null_entry;
1752
1753 while (fn) {
1754 child_left = rcu_dereference_protected(fn->left,
1755 lockdep_is_held(&table->tb6_lock));
1756 child_right = rcu_dereference_protected(fn->right,
1757 lockdep_is_held(&table->tb6_lock));
1758 if (child_left)
1759 return rcu_dereference_protected(child_left->leaf,
1760 lockdep_is_held(&table->tb6_lock));
1761 if (child_right)
1762 return rcu_dereference_protected(child_right->leaf,
1763 lockdep_is_held(&table->tb6_lock));
1764
1765 fn = FIB6_SUBTREE(fn);
1766 }
1767 return NULL;
1768 }
1769
1770 /*
1771 * Called to trim the tree of intermediate nodes when possible. "fn"
1772 * is the node we want to try and remove.
1773 * Need to own table->tb6_lock
1774 */
1775
fib6_repair_tree(struct net * net,struct fib6_table * table,struct fib6_node * fn)1776 static struct fib6_node *fib6_repair_tree(struct net *net,
1777 struct fib6_table *table,
1778 struct fib6_node *fn)
1779 {
1780 int children;
1781 int nstate;
1782 struct fib6_node *child;
1783 struct fib6_walker *w;
1784 int iter = 0;
1785
1786 /* Set fn->leaf to null_entry for root node. */
1787 if (fn->fn_flags & RTN_TL_ROOT) {
1788 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry);
1789 return fn;
1790 }
1791
1792 for (;;) {
1793 struct fib6_node *fn_r = rcu_dereference_protected(fn->right,
1794 lockdep_is_held(&table->tb6_lock));
1795 struct fib6_node *fn_l = rcu_dereference_protected(fn->left,
1796 lockdep_is_held(&table->tb6_lock));
1797 struct fib6_node *pn = rcu_dereference_protected(fn->parent,
1798 lockdep_is_held(&table->tb6_lock));
1799 struct fib6_node *pn_r = rcu_dereference_protected(pn->right,
1800 lockdep_is_held(&table->tb6_lock));
1801 struct fib6_node *pn_l = rcu_dereference_protected(pn->left,
1802 lockdep_is_held(&table->tb6_lock));
1803 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf,
1804 lockdep_is_held(&table->tb6_lock));
1805 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf,
1806 lockdep_is_held(&table->tb6_lock));
1807 struct fib6_info *new_fn_leaf;
1808
1809 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1810 iter++;
1811
1812 WARN_ON(fn->fn_flags & RTN_RTINFO);
1813 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1814 WARN_ON(fn_leaf);
1815
1816 children = 0;
1817 child = NULL;
1818 if (fn_r) {
1819 child = fn_r;
1820 children |= 1;
1821 }
1822 if (fn_l) {
1823 child = fn_l;
1824 children |= 2;
1825 }
1826
1827 if (children == 3 || FIB6_SUBTREE(fn)
1828 #ifdef CONFIG_IPV6_SUBTREES
1829 /* Subtree root (i.e. fn) may have one child */
1830 || (children && fn->fn_flags & RTN_ROOT)
1831 #endif
1832 ) {
1833 new_fn_leaf = fib6_find_prefix(net, table, fn);
1834 #if RT6_DEBUG >= 2
1835 if (!new_fn_leaf) {
1836 WARN_ON(!new_fn_leaf);
1837 new_fn_leaf = net->ipv6.fib6_null_entry;
1838 }
1839 #endif
1840 fib6_info_hold(new_fn_leaf);
1841 rcu_assign_pointer(fn->leaf, new_fn_leaf);
1842 return pn;
1843 }
1844
1845 #ifdef CONFIG_IPV6_SUBTREES
1846 if (FIB6_SUBTREE(pn) == fn) {
1847 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1848 RCU_INIT_POINTER(pn->subtree, NULL);
1849 nstate = FWS_L;
1850 } else {
1851 WARN_ON(fn->fn_flags & RTN_ROOT);
1852 #endif
1853 if (pn_r == fn)
1854 rcu_assign_pointer(pn->right, child);
1855 else if (pn_l == fn)
1856 rcu_assign_pointer(pn->left, child);
1857 #if RT6_DEBUG >= 2
1858 else
1859 WARN_ON(1);
1860 #endif
1861 if (child)
1862 rcu_assign_pointer(child->parent, pn);
1863 nstate = FWS_R;
1864 #ifdef CONFIG_IPV6_SUBTREES
1865 }
1866 #endif
1867
1868 read_lock(&net->ipv6.fib6_walker_lock);
1869 FOR_WALKERS(net, w) {
1870 if (!child) {
1871 if (w->node == fn) {
1872 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1873 w->node = pn;
1874 w->state = nstate;
1875 }
1876 } else {
1877 if (w->node == fn) {
1878 w->node = child;
1879 if (children&2) {
1880 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1881 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT;
1882 } else {
1883 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1884 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT;
1885 }
1886 }
1887 }
1888 }
1889 read_unlock(&net->ipv6.fib6_walker_lock);
1890
1891 node_free(net, fn);
1892 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
1893 return pn;
1894
1895 RCU_INIT_POINTER(pn->leaf, NULL);
1896 fib6_info_release(pn_leaf);
1897 fn = pn;
1898 }
1899 }
1900
fib6_del_route(struct fib6_table * table,struct fib6_node * fn,struct fib6_info __rcu ** rtp,struct nl_info * info)1901 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
1902 struct fib6_info __rcu **rtp, struct nl_info *info)
1903 {
1904 struct fib6_info *leaf, *replace_rt = NULL;
1905 struct fib6_walker *w;
1906 struct fib6_info *rt = rcu_dereference_protected(*rtp,
1907 lockdep_is_held(&table->tb6_lock));
1908 struct net *net = info->nl_net;
1909 bool notify_del = false;
1910
1911 RT6_TRACE("fib6_del_route\n");
1912
1913 /* If the deleted route is the first in the node and it is not part of
1914 * a multipath route, then we need to replace it with the next route
1915 * in the node, if exists.
1916 */
1917 leaf = rcu_dereference_protected(fn->leaf,
1918 lockdep_is_held(&table->tb6_lock));
1919 if (leaf == rt && !rt->fib6_nsiblings) {
1920 if (rcu_access_pointer(rt->fib6_next))
1921 replace_rt = rcu_dereference_protected(rt->fib6_next,
1922 lockdep_is_held(&table->tb6_lock));
1923 else
1924 notify_del = true;
1925 }
1926
1927 /* Unlink it */
1928 *rtp = rt->fib6_next;
1929 rt->fib6_node = NULL;
1930 net->ipv6.rt6_stats->fib_rt_entries--;
1931 net->ipv6.rt6_stats->fib_discarded_routes++;
1932
1933 /* Reset round-robin state, if necessary */
1934 if (rcu_access_pointer(fn->rr_ptr) == rt)
1935 fn->rr_ptr = NULL;
1936
1937 /* Remove this entry from other siblings */
1938 if (rt->fib6_nsiblings) {
1939 struct fib6_info *sibling, *next_sibling;
1940
1941 /* The route is deleted from a multipath route. If this
1942 * multipath route is the first route in the node, then we need
1943 * to emit a delete notification. Otherwise, we need to skip
1944 * the notification.
1945 */
1946 if (rt->fib6_metric == leaf->fib6_metric &&
1947 rt6_qualify_for_ecmp(leaf))
1948 notify_del = true;
1949 list_for_each_entry_safe(sibling, next_sibling,
1950 &rt->fib6_siblings, fib6_siblings)
1951 sibling->fib6_nsiblings--;
1952 rt->fib6_nsiblings = 0;
1953 list_del_init(&rt->fib6_siblings);
1954 rt6_multipath_rebalance(next_sibling);
1955 }
1956
1957 /* Adjust walkers */
1958 read_lock(&net->ipv6.fib6_walker_lock);
1959 FOR_WALKERS(net, w) {
1960 if (w->state == FWS_C && w->leaf == rt) {
1961 RT6_TRACE("walker %p adjusted by delroute\n", w);
1962 w->leaf = rcu_dereference_protected(rt->fib6_next,
1963 lockdep_is_held(&table->tb6_lock));
1964 if (!w->leaf)
1965 w->state = FWS_U;
1966 }
1967 }
1968 read_unlock(&net->ipv6.fib6_walker_lock);
1969
1970 /* If it was last route, call fib6_repair_tree() to:
1971 * 1. For root node, put back null_entry as how the table was created.
1972 * 2. For other nodes, expunge its radix tree node.
1973 */
1974 if (!rcu_access_pointer(fn->leaf)) {
1975 if (!(fn->fn_flags & RTN_TL_ROOT)) {
1976 fn->fn_flags &= ~RTN_RTINFO;
1977 net->ipv6.rt6_stats->fib_route_nodes--;
1978 }
1979 fn = fib6_repair_tree(net, table, fn);
1980 }
1981
1982 fib6_purge_rt(rt, fn, net);
1983
1984 if (!info->skip_notify_kernel) {
1985 if (notify_del)
1986 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL,
1987 rt, NULL);
1988 else if (replace_rt)
1989 call_fib6_entry_notifiers_replace(net, replace_rt);
1990 }
1991 if (!info->skip_notify)
1992 inet6_rt_notify(RTM_DELROUTE, rt, info, 0);
1993
1994 fib6_info_release(rt);
1995 }
1996
1997 /* Need to own table->tb6_lock */
fib6_del(struct fib6_info * rt,struct nl_info * info)1998 int fib6_del(struct fib6_info *rt, struct nl_info *info)
1999 {
2000 struct net *net = info->nl_net;
2001 struct fib6_info __rcu **rtp;
2002 struct fib6_info __rcu **rtp_next;
2003 struct fib6_table *table;
2004 struct fib6_node *fn;
2005
2006 if (rt == net->ipv6.fib6_null_entry)
2007 return -ENOENT;
2008
2009 table = rt->fib6_table;
2010 fn = rcu_dereference_protected(rt->fib6_node,
2011 lockdep_is_held(&table->tb6_lock));
2012 if (!fn)
2013 return -ENOENT;
2014
2015 WARN_ON(!(fn->fn_flags & RTN_RTINFO));
2016
2017 /*
2018 * Walk the leaf entries looking for ourself
2019 */
2020
2021 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) {
2022 struct fib6_info *cur = rcu_dereference_protected(*rtp,
2023 lockdep_is_held(&table->tb6_lock));
2024 if (rt == cur) {
2025 if (fib6_requires_src(cur))
2026 fib6_routes_require_src_dec(info->nl_net);
2027 fib6_del_route(table, fn, rtp, info);
2028 return 0;
2029 }
2030 rtp_next = &cur->fib6_next;
2031 }
2032 return -ENOENT;
2033 }
2034
2035 /*
2036 * Tree traversal function.
2037 *
2038 * Certainly, it is not interrupt safe.
2039 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
2040 * It means, that we can modify tree during walking
2041 * and use this function for garbage collection, clone pruning,
2042 * cleaning tree when a device goes down etc. etc.
2043 *
2044 * It guarantees that every node will be traversed,
2045 * and that it will be traversed only once.
2046 *
2047 * Callback function w->func may return:
2048 * 0 -> continue walking.
2049 * positive value -> walking is suspended (used by tree dumps,
2050 * and probably by gc, if it will be split to several slices)
2051 * negative value -> terminate walking.
2052 *
2053 * The function itself returns:
2054 * 0 -> walk is complete.
2055 * >0 -> walk is incomplete (i.e. suspended)
2056 * <0 -> walk is terminated by an error.
2057 *
2058 * This function is called with tb6_lock held.
2059 */
2060
fib6_walk_continue(struct fib6_walker * w)2061 static int fib6_walk_continue(struct fib6_walker *w)
2062 {
2063 struct fib6_node *fn, *pn, *left, *right;
2064
2065 /* w->root should always be table->tb6_root */
2066 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT));
2067
2068 for (;;) {
2069 fn = w->node;
2070 if (!fn)
2071 return 0;
2072
2073 switch (w->state) {
2074 #ifdef CONFIG_IPV6_SUBTREES
2075 case FWS_S:
2076 if (FIB6_SUBTREE(fn)) {
2077 w->node = FIB6_SUBTREE(fn);
2078 continue;
2079 }
2080 w->state = FWS_L;
2081 fallthrough;
2082 #endif
2083 case FWS_L:
2084 left = rcu_dereference_protected(fn->left, 1);
2085 if (left) {
2086 w->node = left;
2087 w->state = FWS_INIT;
2088 continue;
2089 }
2090 w->state = FWS_R;
2091 fallthrough;
2092 case FWS_R:
2093 right = rcu_dereference_protected(fn->right, 1);
2094 if (right) {
2095 w->node = right;
2096 w->state = FWS_INIT;
2097 continue;
2098 }
2099 w->state = FWS_C;
2100 w->leaf = rcu_dereference_protected(fn->leaf, 1);
2101 fallthrough;
2102 case FWS_C:
2103 if (w->leaf && fn->fn_flags & RTN_RTINFO) {
2104 int err;
2105
2106 if (w->skip) {
2107 w->skip--;
2108 goto skip;
2109 }
2110
2111 err = w->func(w);
2112 if (err)
2113 return err;
2114
2115 w->count++;
2116 continue;
2117 }
2118 skip:
2119 w->state = FWS_U;
2120 fallthrough;
2121 case FWS_U:
2122 if (fn == w->root)
2123 return 0;
2124 pn = rcu_dereference_protected(fn->parent, 1);
2125 left = rcu_dereference_protected(pn->left, 1);
2126 right = rcu_dereference_protected(pn->right, 1);
2127 w->node = pn;
2128 #ifdef CONFIG_IPV6_SUBTREES
2129 if (FIB6_SUBTREE(pn) == fn) {
2130 WARN_ON(!(fn->fn_flags & RTN_ROOT));
2131 w->state = FWS_L;
2132 continue;
2133 }
2134 #endif
2135 if (left == fn) {
2136 w->state = FWS_R;
2137 continue;
2138 }
2139 if (right == fn) {
2140 w->state = FWS_C;
2141 w->leaf = rcu_dereference_protected(w->node->leaf, 1);
2142 continue;
2143 }
2144 #if RT6_DEBUG >= 2
2145 WARN_ON(1);
2146 #endif
2147 }
2148 }
2149 }
2150
fib6_walk(struct net * net,struct fib6_walker * w)2151 static int fib6_walk(struct net *net, struct fib6_walker *w)
2152 {
2153 int res;
2154
2155 w->state = FWS_INIT;
2156 w->node = w->root;
2157
2158 fib6_walker_link(net, w);
2159 res = fib6_walk_continue(w);
2160 if (res <= 0)
2161 fib6_walker_unlink(net, w);
2162 return res;
2163 }
2164
fib6_clean_node(struct fib6_walker * w)2165 static int fib6_clean_node(struct fib6_walker *w)
2166 {
2167 int res;
2168 struct fib6_info *rt;
2169 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w);
2170 struct nl_info info = {
2171 .nl_net = c->net,
2172 .skip_notify = c->skip_notify,
2173 };
2174
2175 if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
2176 w->node->fn_sernum != c->sernum)
2177 w->node->fn_sernum = c->sernum;
2178
2179 if (!c->func) {
2180 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE);
2181 w->leaf = NULL;
2182 return 0;
2183 }
2184
2185 for_each_fib6_walker_rt(w) {
2186 res = c->func(rt, c->arg);
2187 if (res == -1) {
2188 w->leaf = rt;
2189 res = fib6_del(rt, &info);
2190 if (res) {
2191 #if RT6_DEBUG >= 2
2192 pr_debug("%s: del failed: rt=%p@%p err=%d\n",
2193 __func__, rt,
2194 rcu_access_pointer(rt->fib6_node),
2195 res);
2196 #endif
2197 continue;
2198 }
2199 return 0;
2200 } else if (res == -2) {
2201 if (WARN_ON(!rt->fib6_nsiblings))
2202 continue;
2203 rt = list_last_entry(&rt->fib6_siblings,
2204 struct fib6_info, fib6_siblings);
2205 continue;
2206 }
2207 WARN_ON(res != 0);
2208 }
2209 w->leaf = rt;
2210 return 0;
2211 }
2212
2213 /*
2214 * Convenient frontend to tree walker.
2215 *
2216 * func is called on each route.
2217 * It may return -2 -> skip multipath route.
2218 * -1 -> delete this route.
2219 * 0 -> continue walking
2220 */
2221
fib6_clean_tree(struct net * net,struct fib6_node * root,int (* func)(struct fib6_info *,void * arg),int sernum,void * arg,bool skip_notify)2222 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
2223 int (*func)(struct fib6_info *, void *arg),
2224 int sernum, void *arg, bool skip_notify)
2225 {
2226 struct fib6_cleaner c;
2227
2228 c.w.root = root;
2229 c.w.func = fib6_clean_node;
2230 c.w.count = 0;
2231 c.w.skip = 0;
2232 c.w.skip_in_node = 0;
2233 c.func = func;
2234 c.sernum = sernum;
2235 c.arg = arg;
2236 c.net = net;
2237 c.skip_notify = skip_notify;
2238
2239 fib6_walk(net, &c.w);
2240 }
2241
__fib6_clean_all(struct net * net,int (* func)(struct fib6_info *,void *),int sernum,void * arg,bool skip_notify)2242 static void __fib6_clean_all(struct net *net,
2243 int (*func)(struct fib6_info *, void *),
2244 int sernum, void *arg, bool skip_notify)
2245 {
2246 struct fib6_table *table;
2247 struct hlist_head *head;
2248 unsigned int h;
2249
2250 rcu_read_lock();
2251 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
2252 head = &net->ipv6.fib_table_hash[h];
2253 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
2254 spin_lock_bh(&table->tb6_lock);
2255 fib6_clean_tree(net, &table->tb6_root,
2256 func, sernum, arg, skip_notify);
2257 spin_unlock_bh(&table->tb6_lock);
2258 }
2259 }
2260 rcu_read_unlock();
2261 }
2262
fib6_clean_all(struct net * net,int (* func)(struct fib6_info *,void *),void * arg)2263 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *),
2264 void *arg)
2265 {
2266 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, false);
2267 }
2268
fib6_clean_all_skip_notify(struct net * net,int (* func)(struct fib6_info *,void *),void * arg)2269 void fib6_clean_all_skip_notify(struct net *net,
2270 int (*func)(struct fib6_info *, void *),
2271 void *arg)
2272 {
2273 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, true);
2274 }
2275
fib6_flush_trees(struct net * net)2276 static void fib6_flush_trees(struct net *net)
2277 {
2278 int new_sernum = fib6_new_sernum(net);
2279
2280 __fib6_clean_all(net, NULL, new_sernum, NULL, false);
2281 }
2282
2283 /*
2284 * Garbage collection
2285 */
2286
fib6_age(struct fib6_info * rt,void * arg)2287 static int fib6_age(struct fib6_info *rt, void *arg)
2288 {
2289 struct fib6_gc_args *gc_args = arg;
2290 unsigned long now = jiffies;
2291
2292 /*
2293 * check addrconf expiration here.
2294 * Routes are expired even if they are in use.
2295 */
2296
2297 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) {
2298 if (time_after(now, rt->expires)) {
2299 RT6_TRACE("expiring %p\n", rt);
2300 return -1;
2301 }
2302 gc_args->more++;
2303 }
2304
2305 /* Also age clones in the exception table.
2306 * Note, that clones are aged out
2307 * only if they are not in use now.
2308 */
2309 rt6_age_exceptions(rt, gc_args, now);
2310
2311 return 0;
2312 }
2313
fib6_run_gc(unsigned long expires,struct net * net,bool force)2314 void fib6_run_gc(unsigned long expires, struct net *net, bool force)
2315 {
2316 struct fib6_gc_args gc_args;
2317 unsigned long now;
2318
2319 if (force) {
2320 spin_lock_bh(&net->ipv6.fib6_gc_lock);
2321 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) {
2322 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
2323 return;
2324 }
2325 gc_args.timeout = expires ? (int)expires :
2326 net->ipv6.sysctl.ip6_rt_gc_interval;
2327 gc_args.more = 0;
2328
2329 fib6_clean_all(net, fib6_age, &gc_args);
2330 now = jiffies;
2331 net->ipv6.ip6_rt_last_gc = now;
2332
2333 if (gc_args.more)
2334 mod_timer(&net->ipv6.ip6_fib_timer,
2335 round_jiffies(now
2336 + net->ipv6.sysctl.ip6_rt_gc_interval));
2337 else
2338 del_timer(&net->ipv6.ip6_fib_timer);
2339 spin_unlock_bh(&net->ipv6.fib6_gc_lock);
2340 }
2341
fib6_gc_timer_cb(struct timer_list * t)2342 static void fib6_gc_timer_cb(struct timer_list *t)
2343 {
2344 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer);
2345
2346 fib6_run_gc(0, arg, true);
2347 }
2348
fib6_net_init(struct net * net)2349 static int __net_init fib6_net_init(struct net *net)
2350 {
2351 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
2352 int err;
2353
2354 err = fib6_notifier_init(net);
2355 if (err)
2356 return err;
2357
2358 spin_lock_init(&net->ipv6.fib6_gc_lock);
2359 rwlock_init(&net->ipv6.fib6_walker_lock);
2360 INIT_LIST_HEAD(&net->ipv6.fib6_walkers);
2361 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0);
2362
2363 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
2364 if (!net->ipv6.rt6_stats)
2365 goto out_timer;
2366
2367 /* Avoid false sharing : Use at least a full cache line */
2368 size = max_t(size_t, size, L1_CACHE_BYTES);
2369
2370 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
2371 if (!net->ipv6.fib_table_hash)
2372 goto out_rt6_stats;
2373
2374 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
2375 GFP_KERNEL);
2376 if (!net->ipv6.fib6_main_tbl)
2377 goto out_fib_table_hash;
2378
2379 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
2380 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf,
2381 net->ipv6.fib6_null_entry);
2382 net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
2383 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
2384 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
2385
2386 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2387 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
2388 GFP_KERNEL);
2389 if (!net->ipv6.fib6_local_tbl)
2390 goto out_fib6_main_tbl;
2391 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
2392 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf,
2393 net->ipv6.fib6_null_entry);
2394 net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
2395 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
2396 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
2397 #endif
2398 fib6_tables_init(net);
2399
2400 return 0;
2401
2402 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2403 out_fib6_main_tbl:
2404 kfree(net->ipv6.fib6_main_tbl);
2405 #endif
2406 out_fib_table_hash:
2407 kfree(net->ipv6.fib_table_hash);
2408 out_rt6_stats:
2409 kfree(net->ipv6.rt6_stats);
2410 out_timer:
2411 fib6_notifier_exit(net);
2412 return -ENOMEM;
2413 }
2414
fib6_net_exit(struct net * net)2415 static void fib6_net_exit(struct net *net)
2416 {
2417 unsigned int i;
2418
2419 del_timer_sync(&net->ipv6.ip6_fib_timer);
2420
2421 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) {
2422 struct hlist_head *head = &net->ipv6.fib_table_hash[i];
2423 struct hlist_node *tmp;
2424 struct fib6_table *tb;
2425
2426 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) {
2427 hlist_del(&tb->tb6_hlist);
2428 fib6_free_table(tb);
2429 }
2430 }
2431
2432 kfree(net->ipv6.fib_table_hash);
2433 kfree(net->ipv6.rt6_stats);
2434 fib6_notifier_exit(net);
2435 }
2436
2437 static struct pernet_operations fib6_net_ops = {
2438 .init = fib6_net_init,
2439 .exit = fib6_net_exit,
2440 };
2441
fib6_init(void)2442 int __init fib6_init(void)
2443 {
2444 int ret = -ENOMEM;
2445
2446 fib6_node_kmem = kmem_cache_create("fib6_nodes",
2447 sizeof(struct fib6_node),
2448 0, SLAB_HWCACHE_ALIGN,
2449 NULL);
2450 if (!fib6_node_kmem)
2451 goto out;
2452
2453 ret = register_pernet_subsys(&fib6_net_ops);
2454 if (ret)
2455 goto out_kmem_cache_create;
2456
2457 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL,
2458 inet6_dump_fib, 0);
2459 if (ret)
2460 goto out_unregister_subsys;
2461
2462 __fib6_flush_trees = fib6_flush_trees;
2463 out:
2464 return ret;
2465
2466 out_unregister_subsys:
2467 unregister_pernet_subsys(&fib6_net_ops);
2468 out_kmem_cache_create:
2469 kmem_cache_destroy(fib6_node_kmem);
2470 goto out;
2471 }
2472
fib6_gc_cleanup(void)2473 void fib6_gc_cleanup(void)
2474 {
2475 unregister_pernet_subsys(&fib6_net_ops);
2476 kmem_cache_destroy(fib6_node_kmem);
2477 }
2478
2479 #ifdef CONFIG_PROC_FS
ipv6_route_native_seq_show(struct seq_file * seq,void * v)2480 static int ipv6_route_native_seq_show(struct seq_file *seq, void *v)
2481 {
2482 struct fib6_info *rt = v;
2483 struct ipv6_route_iter *iter = seq->private;
2484 struct fib6_nh *fib6_nh = rt->fib6_nh;
2485 unsigned int flags = rt->fib6_flags;
2486 const struct net_device *dev;
2487
2488 if (rt->nh)
2489 fib6_nh = nexthop_fib6_nh_bh(rt->nh);
2490
2491 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen);
2492
2493 #ifdef CONFIG_IPV6_SUBTREES
2494 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen);
2495 #else
2496 seq_puts(seq, "00000000000000000000000000000000 00 ");
2497 #endif
2498 if (fib6_nh->fib_nh_gw_family) {
2499 flags |= RTF_GATEWAY;
2500 seq_printf(seq, "%pi6", &fib6_nh->fib_nh_gw6);
2501 } else {
2502 seq_puts(seq, "00000000000000000000000000000000");
2503 }
2504
2505 dev = fib6_nh->fib_nh_dev;
2506 seq_printf(seq, " %08x %08x %08x %08x %8s\n",
2507 rt->fib6_metric, refcount_read(&rt->fib6_ref), 0,
2508 flags, dev ? dev->name : "");
2509 iter->w.leaf = NULL;
2510 return 0;
2511 }
2512
ipv6_route_yield(struct fib6_walker * w)2513 static int ipv6_route_yield(struct fib6_walker *w)
2514 {
2515 struct ipv6_route_iter *iter = w->args;
2516
2517 if (!iter->skip)
2518 return 1;
2519
2520 do {
2521 iter->w.leaf = rcu_dereference_protected(
2522 iter->w.leaf->fib6_next,
2523 lockdep_is_held(&iter->tbl->tb6_lock));
2524 iter->skip--;
2525 if (!iter->skip && iter->w.leaf)
2526 return 1;
2527 } while (iter->w.leaf);
2528
2529 return 0;
2530 }
2531
ipv6_route_seq_setup_walk(struct ipv6_route_iter * iter,struct net * net)2532 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter,
2533 struct net *net)
2534 {
2535 memset(&iter->w, 0, sizeof(iter->w));
2536 iter->w.func = ipv6_route_yield;
2537 iter->w.root = &iter->tbl->tb6_root;
2538 iter->w.state = FWS_INIT;
2539 iter->w.node = iter->w.root;
2540 iter->w.args = iter;
2541 iter->sernum = iter->w.root->fn_sernum;
2542 INIT_LIST_HEAD(&iter->w.lh);
2543 fib6_walker_link(net, &iter->w);
2544 }
2545
ipv6_route_seq_next_table(struct fib6_table * tbl,struct net * net)2546 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
2547 struct net *net)
2548 {
2549 unsigned int h;
2550 struct hlist_node *node;
2551
2552 if (tbl) {
2553 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1;
2554 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist));
2555 } else {
2556 h = 0;
2557 node = NULL;
2558 }
2559
2560 while (!node && h < FIB6_TABLE_HASHSZ) {
2561 node = rcu_dereference_bh(
2562 hlist_first_rcu(&net->ipv6.fib_table_hash[h++]));
2563 }
2564 return hlist_entry_safe(node, struct fib6_table, tb6_hlist);
2565 }
2566
ipv6_route_check_sernum(struct ipv6_route_iter * iter)2567 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter)
2568 {
2569 if (iter->sernum != iter->w.root->fn_sernum) {
2570 iter->sernum = iter->w.root->fn_sernum;
2571 iter->w.state = FWS_INIT;
2572 iter->w.node = iter->w.root;
2573 WARN_ON(iter->w.skip);
2574 iter->w.skip = iter->w.count;
2575 }
2576 }
2577
ipv6_route_seq_next(struct seq_file * seq,void * v,loff_t * pos)2578 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2579 {
2580 int r;
2581 struct fib6_info *n;
2582 struct net *net = seq_file_net(seq);
2583 struct ipv6_route_iter *iter = seq->private;
2584
2585 ++(*pos);
2586 if (!v)
2587 goto iter_table;
2588
2589 n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next);
2590 if (n)
2591 return n;
2592
2593 iter_table:
2594 ipv6_route_check_sernum(iter);
2595 spin_lock_bh(&iter->tbl->tb6_lock);
2596 r = fib6_walk_continue(&iter->w);
2597 spin_unlock_bh(&iter->tbl->tb6_lock);
2598 if (r > 0) {
2599 return iter->w.leaf;
2600 } else if (r < 0) {
2601 fib6_walker_unlink(net, &iter->w);
2602 return NULL;
2603 }
2604 fib6_walker_unlink(net, &iter->w);
2605
2606 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
2607 if (!iter->tbl)
2608 return NULL;
2609
2610 ipv6_route_seq_setup_walk(iter, net);
2611 goto iter_table;
2612 }
2613
ipv6_route_seq_start(struct seq_file * seq,loff_t * pos)2614 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
2615 __acquires(RCU_BH)
2616 {
2617 struct net *net = seq_file_net(seq);
2618 struct ipv6_route_iter *iter = seq->private;
2619
2620 rcu_read_lock_bh();
2621 iter->tbl = ipv6_route_seq_next_table(NULL, net);
2622 iter->skip = *pos;
2623
2624 if (iter->tbl) {
2625 loff_t p = 0;
2626
2627 ipv6_route_seq_setup_walk(iter, net);
2628 return ipv6_route_seq_next(seq, NULL, &p);
2629 } else {
2630 return NULL;
2631 }
2632 }
2633
ipv6_route_iter_active(struct ipv6_route_iter * iter)2634 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter)
2635 {
2636 struct fib6_walker *w = &iter->w;
2637 return w->node && !(w->state == FWS_U && w->node == w->root);
2638 }
2639
ipv6_route_native_seq_stop(struct seq_file * seq,void * v)2640 static void ipv6_route_native_seq_stop(struct seq_file *seq, void *v)
2641 __releases(RCU_BH)
2642 {
2643 struct net *net = seq_file_net(seq);
2644 struct ipv6_route_iter *iter = seq->private;
2645
2646 if (ipv6_route_iter_active(iter))
2647 fib6_walker_unlink(net, &iter->w);
2648
2649 rcu_read_unlock_bh();
2650 }
2651
2652 #if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL)
ipv6_route_prog_seq_show(struct bpf_prog * prog,struct bpf_iter_meta * meta,void * v)2653 static int ipv6_route_prog_seq_show(struct bpf_prog *prog,
2654 struct bpf_iter_meta *meta,
2655 void *v)
2656 {
2657 struct bpf_iter__ipv6_route ctx;
2658
2659 ctx.meta = meta;
2660 ctx.rt = v;
2661 return bpf_iter_run_prog(prog, &ctx);
2662 }
2663
ipv6_route_seq_show(struct seq_file * seq,void * v)2664 static int ipv6_route_seq_show(struct seq_file *seq, void *v)
2665 {
2666 struct ipv6_route_iter *iter = seq->private;
2667 struct bpf_iter_meta meta;
2668 struct bpf_prog *prog;
2669 int ret;
2670
2671 meta.seq = seq;
2672 prog = bpf_iter_get_info(&meta, false);
2673 if (!prog)
2674 return ipv6_route_native_seq_show(seq, v);
2675
2676 ret = ipv6_route_prog_seq_show(prog, &meta, v);
2677 iter->w.leaf = NULL;
2678
2679 return ret;
2680 }
2681
ipv6_route_seq_stop(struct seq_file * seq,void * v)2682 static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
2683 {
2684 struct bpf_iter_meta meta;
2685 struct bpf_prog *prog;
2686
2687 if (!v) {
2688 meta.seq = seq;
2689 prog = bpf_iter_get_info(&meta, true);
2690 if (prog)
2691 (void)ipv6_route_prog_seq_show(prog, &meta, v);
2692 }
2693
2694 ipv6_route_native_seq_stop(seq, v);
2695 }
2696 #else
ipv6_route_seq_show(struct seq_file * seq,void * v)2697 static int ipv6_route_seq_show(struct seq_file *seq, void *v)
2698 {
2699 return ipv6_route_native_seq_show(seq, v);
2700 }
2701
ipv6_route_seq_stop(struct seq_file * seq,void * v)2702 static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
2703 {
2704 ipv6_route_native_seq_stop(seq, v);
2705 }
2706 #endif
2707
2708 const struct seq_operations ipv6_route_seq_ops = {
2709 .start = ipv6_route_seq_start,
2710 .next = ipv6_route_seq_next,
2711 .stop = ipv6_route_seq_stop,
2712 .show = ipv6_route_seq_show
2713 };
2714 #endif /* CONFIG_PROC_FS */
2715