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/bpf.h> |
19 | #include <linux/errno.h> |
20 | #include <linux/types.h> |
21 | #include <linux/net.h> |
22 | #include <linux/route.h> |
23 | #include <linux/netdevice.h> |
24 | #include <linux/in6.h> |
25 | #include <linux/init.h> |
26 | #include <linux/list.h> |
27 | #include <linux/slab.h> |
28 | |
29 | #include <net/ip.h> |
30 | #include <net/ipv6.h> |
31 | #include <net/ndisc.h> |
32 | #include <net/addrconf.h> |
33 | #include <net/lwtunnel.h> |
34 | #include <net/fib_notifier.h> |
35 | |
36 | #include <net/ip_fib.h> |
37 | #include <net/ip6_fib.h> |
38 | #include <net/ip6_route.h> |
39 | |
40 | static struct kmem_cache *fib6_node_kmem __read_mostly; |
41 | |
42 | struct fib6_cleaner { |
43 | struct fib6_walker w; |
44 | struct net *net; |
45 | int (*func)(struct fib6_info *, void *arg); |
46 | int sernum; |
47 | void *arg; |
48 | bool skip_notify; |
49 | }; |
50 | |
51 | #ifdef CONFIG_IPV6_SUBTREES |
52 | #define FWS_INIT FWS_S |
53 | #else |
54 | #define FWS_INIT FWS_L |
55 | #endif |
56 | |
57 | static struct fib6_info *fib6_find_prefix(struct net *net, |
58 | struct fib6_table *table, |
59 | struct fib6_node *fn); |
60 | static struct fib6_node *fib6_repair_tree(struct net *net, |
61 | struct fib6_table *table, |
62 | struct fib6_node *fn); |
63 | static int fib6_walk(struct net *net, struct fib6_walker *w); |
64 | static int fib6_walk_continue(struct fib6_walker *w); |
65 | |
66 | /* |
67 | * A routing update causes an increase of the serial number on the |
68 | * affected subtree. This allows for cached routes to be asynchronously |
69 | * tested when modifications are made to the destination cache as a |
70 | * result of redirects, path MTU changes, etc. |
71 | */ |
72 | |
73 | static void fib6_gc_timer_cb(struct timer_list *t); |
74 | |
75 | #define FOR_WALKERS(net, w) \ |
76 | list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh) |
77 | |
78 | static void fib6_walker_link(struct net *net, struct fib6_walker *w) |
79 | { |
80 | write_lock_bh(&net->ipv6.fib6_walker_lock); |
81 | list_add(new: &w->lh, head: &net->ipv6.fib6_walkers); |
82 | write_unlock_bh(&net->ipv6.fib6_walker_lock); |
83 | } |
84 | |
85 | static void fib6_walker_unlink(struct net *net, struct fib6_walker *w) |
86 | { |
87 | write_lock_bh(&net->ipv6.fib6_walker_lock); |
88 | list_del(entry: &w->lh); |
89 | write_unlock_bh(&net->ipv6.fib6_walker_lock); |
90 | } |
91 | |
92 | static int fib6_new_sernum(struct net *net) |
93 | { |
94 | int new, old = atomic_read(v: &net->ipv6.fib6_sernum); |
95 | |
96 | do { |
97 | new = old < INT_MAX ? old + 1 : 1; |
98 | } while (!atomic_try_cmpxchg(v: &net->ipv6.fib6_sernum, old: &old, new)); |
99 | |
100 | return new; |
101 | } |
102 | |
103 | enum { |
104 | FIB6_NO_SERNUM_CHANGE = 0, |
105 | }; |
106 | |
107 | void fib6_update_sernum(struct net *net, struct fib6_info *f6i) |
108 | { |
109 | struct fib6_node *fn; |
110 | |
111 | fn = rcu_dereference_protected(f6i->fib6_node, |
112 | lockdep_is_held(&f6i->fib6_table->tb6_lock)); |
113 | if (fn) |
114 | WRITE_ONCE(fn->fn_sernum, fib6_new_sernum(net)); |
115 | } |
116 | |
117 | /* |
118 | * Auxiliary address test functions for the radix tree. |
119 | * |
120 | * These assume a 32bit processor (although it will work on |
121 | * 64bit processors) |
122 | */ |
123 | |
124 | /* |
125 | * test bit |
126 | */ |
127 | #if defined(__LITTLE_ENDIAN) |
128 | # define BITOP_BE32_SWIZZLE (0x1F & ~7) |
129 | #else |
130 | # define BITOP_BE32_SWIZZLE 0 |
131 | #endif |
132 | |
133 | static __be32 addr_bit_set(const void *token, int fn_bit) |
134 | { |
135 | const __be32 *addr = token; |
136 | /* |
137 | * Here, |
138 | * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) |
139 | * is optimized version of |
140 | * htonl(1 << ((~fn_bit)&0x1F)) |
141 | * See include/asm-generic/bitops/le.h. |
142 | */ |
143 | return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & |
144 | addr[fn_bit >> 5]; |
145 | } |
146 | |
147 | struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh) |
148 | { |
149 | struct fib6_info *f6i; |
150 | size_t sz = sizeof(*f6i); |
151 | |
152 | if (with_fib6_nh) |
153 | sz += sizeof(struct fib6_nh); |
154 | |
155 | f6i = kzalloc(size: sz, flags: gfp_flags); |
156 | if (!f6i) |
157 | return NULL; |
158 | |
159 | /* fib6_siblings is a union with nh_list, so this initializes both */ |
160 | INIT_LIST_HEAD(list: &f6i->fib6_siblings); |
161 | refcount_set(r: &f6i->fib6_ref, n: 1); |
162 | |
163 | INIT_HLIST_NODE(h: &f6i->gc_link); |
164 | |
165 | return f6i; |
166 | } |
167 | |
168 | void fib6_info_destroy_rcu(struct rcu_head *head) |
169 | { |
170 | struct fib6_info *f6i = container_of(head, struct fib6_info, rcu); |
171 | |
172 | WARN_ON(f6i->fib6_node); |
173 | |
174 | if (f6i->nh) |
175 | nexthop_put(nh: f6i->nh); |
176 | else |
177 | fib6_nh_release(fib6_nh: f6i->fib6_nh); |
178 | |
179 | ip_fib_metrics_put(fib_metrics: f6i->fib6_metrics); |
180 | kfree(objp: f6i); |
181 | } |
182 | EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu); |
183 | |
184 | static struct fib6_node *node_alloc(struct net *net) |
185 | { |
186 | struct fib6_node *fn; |
187 | |
188 | fn = kmem_cache_zalloc(k: fib6_node_kmem, GFP_ATOMIC); |
189 | if (fn) |
190 | net->ipv6.rt6_stats->fib_nodes++; |
191 | |
192 | return fn; |
193 | } |
194 | |
195 | static void node_free_immediate(struct net *net, struct fib6_node *fn) |
196 | { |
197 | kmem_cache_free(s: fib6_node_kmem, objp: fn); |
198 | net->ipv6.rt6_stats->fib_nodes--; |
199 | } |
200 | |
201 | static void node_free_rcu(struct rcu_head *head) |
202 | { |
203 | struct fib6_node *fn = container_of(head, struct fib6_node, rcu); |
204 | |
205 | kmem_cache_free(s: fib6_node_kmem, objp: fn); |
206 | } |
207 | |
208 | static void node_free(struct net *net, struct fib6_node *fn) |
209 | { |
210 | call_rcu(head: &fn->rcu, func: node_free_rcu); |
211 | net->ipv6.rt6_stats->fib_nodes--; |
212 | } |
213 | |
214 | static void fib6_free_table(struct fib6_table *table) |
215 | { |
216 | inetpeer_invalidate_tree(&table->tb6_peers); |
217 | kfree(objp: table); |
218 | } |
219 | |
220 | static void fib6_link_table(struct net *net, struct fib6_table *tb) |
221 | { |
222 | unsigned int h; |
223 | |
224 | /* |
225 | * Initialize table lock at a single place to give lockdep a key, |
226 | * tables aren't visible prior to being linked to the list. |
227 | */ |
228 | spin_lock_init(&tb->tb6_lock); |
229 | h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); |
230 | |
231 | /* |
232 | * No protection necessary, this is the only list mutatation |
233 | * operation, tables never disappear once they exist. |
234 | */ |
235 | hlist_add_head_rcu(n: &tb->tb6_hlist, h: &net->ipv6.fib_table_hash[h]); |
236 | } |
237 | |
238 | #ifdef CONFIG_IPV6_MULTIPLE_TABLES |
239 | |
240 | static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) |
241 | { |
242 | struct fib6_table *table; |
243 | |
244 | table = kzalloc(size: sizeof(*table), GFP_ATOMIC); |
245 | if (table) { |
246 | table->tb6_id = id; |
247 | rcu_assign_pointer(table->tb6_root.leaf, |
248 | net->ipv6.fib6_null_entry); |
249 | table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; |
250 | inet_peer_base_init(&table->tb6_peers); |
251 | INIT_HLIST_HEAD(&table->tb6_gc_hlist); |
252 | } |
253 | |
254 | return table; |
255 | } |
256 | |
257 | struct fib6_table *fib6_new_table(struct net *net, u32 id) |
258 | { |
259 | struct fib6_table *tb; |
260 | |
261 | if (id == 0) |
262 | id = RT6_TABLE_MAIN; |
263 | tb = fib6_get_table(net, id); |
264 | if (tb) |
265 | return tb; |
266 | |
267 | tb = fib6_alloc_table(net, id); |
268 | if (tb) |
269 | fib6_link_table(net, tb); |
270 | |
271 | return tb; |
272 | } |
273 | EXPORT_SYMBOL_GPL(fib6_new_table); |
274 | |
275 | struct fib6_table *fib6_get_table(struct net *net, u32 id) |
276 | { |
277 | struct fib6_table *tb; |
278 | struct hlist_head *head; |
279 | unsigned int h; |
280 | |
281 | if (id == 0) |
282 | id = RT6_TABLE_MAIN; |
283 | h = id & (FIB6_TABLE_HASHSZ - 1); |
284 | rcu_read_lock(); |
285 | head = &net->ipv6.fib_table_hash[h]; |
286 | hlist_for_each_entry_rcu(tb, head, tb6_hlist) { |
287 | if (tb->tb6_id == id) { |
288 | rcu_read_unlock(); |
289 | return tb; |
290 | } |
291 | } |
292 | rcu_read_unlock(); |
293 | |
294 | return NULL; |
295 | } |
296 | EXPORT_SYMBOL_GPL(fib6_get_table); |
297 | |
298 | static void __net_init fib6_tables_init(struct net *net) |
299 | { |
300 | fib6_link_table(net, tb: net->ipv6.fib6_main_tbl); |
301 | fib6_link_table(net, tb: net->ipv6.fib6_local_tbl); |
302 | } |
303 | #else |
304 | |
305 | struct fib6_table *fib6_new_table(struct net *net, u32 id) |
306 | { |
307 | return fib6_get_table(net, id); |
308 | } |
309 | |
310 | struct fib6_table *fib6_get_table(struct net *net, u32 id) |
311 | { |
312 | return net->ipv6.fib6_main_tbl; |
313 | } |
314 | |
315 | struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, |
316 | const struct sk_buff *skb, |
317 | int flags, pol_lookup_t lookup) |
318 | { |
319 | struct rt6_info *rt; |
320 | |
321 | rt = pol_lookup_func(lookup, |
322 | net, net->ipv6.fib6_main_tbl, fl6, skb, flags); |
323 | if (rt->dst.error == -EAGAIN) { |
324 | ip6_rt_put_flags(rt, flags); |
325 | rt = net->ipv6.ip6_null_entry; |
326 | if (!(flags & RT6_LOOKUP_F_DST_NOREF)) |
327 | dst_hold(&rt->dst); |
328 | } |
329 | |
330 | return &rt->dst; |
331 | } |
332 | |
333 | /* called with rcu lock held; no reference taken on fib6_info */ |
334 | int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, |
335 | struct fib6_result *res, int flags) |
336 | { |
337 | return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6, |
338 | res, flags); |
339 | } |
340 | |
341 | static void __net_init fib6_tables_init(struct net *net) |
342 | { |
343 | fib6_link_table(net, net->ipv6.fib6_main_tbl); |
344 | } |
345 | |
346 | #endif |
347 | |
348 | unsigned int fib6_tables_seq_read(struct net *net) |
349 | { |
350 | unsigned int h, fib_seq = 0; |
351 | |
352 | rcu_read_lock(); |
353 | for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { |
354 | struct hlist_head *head = &net->ipv6.fib_table_hash[h]; |
355 | struct fib6_table *tb; |
356 | |
357 | hlist_for_each_entry_rcu(tb, head, tb6_hlist) |
358 | fib_seq += tb->fib_seq; |
359 | } |
360 | rcu_read_unlock(); |
361 | |
362 | return fib_seq; |
363 | } |
364 | |
365 | static int call_fib6_entry_notifier(struct notifier_block *nb, |
366 | enum fib_event_type event_type, |
367 | struct fib6_info *rt, |
368 | struct netlink_ext_ack *extack) |
369 | { |
370 | struct fib6_entry_notifier_info info = { |
371 | .info.extack = extack, |
372 | .rt = rt, |
373 | }; |
374 | |
375 | return call_fib6_notifier(nb, event_type, info: &info.info); |
376 | } |
377 | |
378 | static int call_fib6_multipath_entry_notifier(struct notifier_block *nb, |
379 | enum fib_event_type event_type, |
380 | struct fib6_info *rt, |
381 | unsigned int nsiblings, |
382 | struct netlink_ext_ack *extack) |
383 | { |
384 | struct fib6_entry_notifier_info info = { |
385 | .info.extack = extack, |
386 | .rt = rt, |
387 | .nsiblings = nsiblings, |
388 | }; |
389 | |
390 | return call_fib6_notifier(nb, event_type, info: &info.info); |
391 | } |
392 | |
393 | int call_fib6_entry_notifiers(struct net *net, |
394 | enum fib_event_type event_type, |
395 | struct fib6_info *rt, |
396 | struct netlink_ext_ack *extack) |
397 | { |
398 | struct fib6_entry_notifier_info info = { |
399 | .info.extack = extack, |
400 | .rt = rt, |
401 | }; |
402 | |
403 | rt->fib6_table->fib_seq++; |
404 | return call_fib6_notifiers(net, event_type, info: &info.info); |
405 | } |
406 | |
407 | int call_fib6_multipath_entry_notifiers(struct net *net, |
408 | enum fib_event_type event_type, |
409 | struct fib6_info *rt, |
410 | unsigned int nsiblings, |
411 | struct netlink_ext_ack *extack) |
412 | { |
413 | struct fib6_entry_notifier_info info = { |
414 | .info.extack = extack, |
415 | .rt = rt, |
416 | .nsiblings = nsiblings, |
417 | }; |
418 | |
419 | rt->fib6_table->fib_seq++; |
420 | return call_fib6_notifiers(net, event_type, info: &info.info); |
421 | } |
422 | |
423 | int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt) |
424 | { |
425 | struct fib6_entry_notifier_info info = { |
426 | .rt = rt, |
427 | .nsiblings = rt->fib6_nsiblings, |
428 | }; |
429 | |
430 | rt->fib6_table->fib_seq++; |
431 | return call_fib6_notifiers(net, event_type: FIB_EVENT_ENTRY_REPLACE, info: &info.info); |
432 | } |
433 | |
434 | struct fib6_dump_arg { |
435 | struct net *net; |
436 | struct notifier_block *nb; |
437 | struct netlink_ext_ack *extack; |
438 | }; |
439 | |
440 | static int fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg) |
441 | { |
442 | enum fib_event_type fib_event = FIB_EVENT_ENTRY_REPLACE; |
443 | int err; |
444 | |
445 | if (!rt || rt == arg->net->ipv6.fib6_null_entry) |
446 | return 0; |
447 | |
448 | if (rt->fib6_nsiblings) |
449 | err = call_fib6_multipath_entry_notifier(nb: arg->nb, event_type: fib_event, |
450 | rt, |
451 | nsiblings: rt->fib6_nsiblings, |
452 | extack: arg->extack); |
453 | else |
454 | err = call_fib6_entry_notifier(nb: arg->nb, event_type: fib_event, rt, |
455 | extack: arg->extack); |
456 | |
457 | return err; |
458 | } |
459 | |
460 | static int fib6_node_dump(struct fib6_walker *w) |
461 | { |
462 | int err; |
463 | |
464 | err = fib6_rt_dump(rt: w->leaf, arg: w->args); |
465 | w->leaf = NULL; |
466 | return err; |
467 | } |
468 | |
469 | static int fib6_table_dump(struct net *net, struct fib6_table *tb, |
470 | struct fib6_walker *w) |
471 | { |
472 | int err; |
473 | |
474 | w->root = &tb->tb6_root; |
475 | spin_lock_bh(lock: &tb->tb6_lock); |
476 | err = fib6_walk(net, w); |
477 | spin_unlock_bh(lock: &tb->tb6_lock); |
478 | return err; |
479 | } |
480 | |
481 | /* Called with rcu_read_lock() */ |
482 | int fib6_tables_dump(struct net *net, struct notifier_block *nb, |
483 | struct netlink_ext_ack *extack) |
484 | { |
485 | struct fib6_dump_arg arg; |
486 | struct fib6_walker *w; |
487 | unsigned int h; |
488 | int err = 0; |
489 | |
490 | w = kzalloc(size: sizeof(*w), GFP_ATOMIC); |
491 | if (!w) |
492 | return -ENOMEM; |
493 | |
494 | w->func = fib6_node_dump; |
495 | arg.net = net; |
496 | arg.nb = nb; |
497 | arg.extack = extack; |
498 | w->args = &arg; |
499 | |
500 | for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { |
501 | struct hlist_head *head = &net->ipv6.fib_table_hash[h]; |
502 | struct fib6_table *tb; |
503 | |
504 | hlist_for_each_entry_rcu(tb, head, tb6_hlist) { |
505 | err = fib6_table_dump(net, tb, w); |
506 | if (err) |
507 | goto out; |
508 | } |
509 | } |
510 | |
511 | out: |
512 | kfree(objp: w); |
513 | |
514 | /* The tree traversal function should never return a positive value. */ |
515 | return err > 0 ? -EINVAL : err; |
516 | } |
517 | |
518 | static int fib6_dump_node(struct fib6_walker *w) |
519 | { |
520 | int res; |
521 | struct fib6_info *rt; |
522 | |
523 | for_each_fib6_walker_rt(w) { |
524 | res = rt6_dump_route(f6i: rt, p_arg: w->args, skip: w->skip_in_node); |
525 | if (res >= 0) { |
526 | /* Frame is full, suspend walking */ |
527 | w->leaf = rt; |
528 | |
529 | /* We'll restart from this node, so if some routes were |
530 | * already dumped, skip them next time. |
531 | */ |
532 | w->skip_in_node += res; |
533 | |
534 | return 1; |
535 | } |
536 | w->skip_in_node = 0; |
537 | |
538 | /* Multipath routes are dumped in one route with the |
539 | * RTA_MULTIPATH attribute. Jump 'rt' to point to the |
540 | * last sibling of this route (no need to dump the |
541 | * sibling routes again) |
542 | */ |
543 | if (rt->fib6_nsiblings) |
544 | rt = list_last_entry(&rt->fib6_siblings, |
545 | struct fib6_info, |
546 | fib6_siblings); |
547 | } |
548 | w->leaf = NULL; |
549 | return 0; |
550 | } |
551 | |
552 | static void fib6_dump_end(struct netlink_callback *cb) |
553 | { |
554 | struct net *net = sock_net(sk: cb->skb->sk); |
555 | struct fib6_walker *w = (void *)cb->args[2]; |
556 | |
557 | if (w) { |
558 | if (cb->args[4]) { |
559 | cb->args[4] = 0; |
560 | fib6_walker_unlink(net, w); |
561 | } |
562 | cb->args[2] = 0; |
563 | kfree(objp: w); |
564 | } |
565 | cb->done = (void *)cb->args[3]; |
566 | cb->args[1] = 3; |
567 | } |
568 | |
569 | static int fib6_dump_done(struct netlink_callback *cb) |
570 | { |
571 | fib6_dump_end(cb); |
572 | return cb->done ? cb->done(cb) : 0; |
573 | } |
574 | |
575 | static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, |
576 | struct netlink_callback *cb) |
577 | { |
578 | struct net *net = sock_net(sk: skb->sk); |
579 | struct fib6_walker *w; |
580 | int res; |
581 | |
582 | w = (void *)cb->args[2]; |
583 | w->root = &table->tb6_root; |
584 | |
585 | if (cb->args[4] == 0) { |
586 | w->count = 0; |
587 | w->skip = 0; |
588 | w->skip_in_node = 0; |
589 | |
590 | spin_lock_bh(lock: &table->tb6_lock); |
591 | res = fib6_walk(net, w); |
592 | spin_unlock_bh(lock: &table->tb6_lock); |
593 | if (res > 0) { |
594 | cb->args[4] = 1; |
595 | cb->args[5] = READ_ONCE(w->root->fn_sernum); |
596 | } |
597 | } else { |
598 | int sernum = READ_ONCE(w->root->fn_sernum); |
599 | if (cb->args[5] != sernum) { |
600 | /* Begin at the root if the tree changed */ |
601 | cb->args[5] = sernum; |
602 | w->state = FWS_INIT; |
603 | w->node = w->root; |
604 | w->skip = w->count; |
605 | w->skip_in_node = 0; |
606 | } else |
607 | w->skip = 0; |
608 | |
609 | spin_lock_bh(lock: &table->tb6_lock); |
610 | res = fib6_walk_continue(w); |
611 | spin_unlock_bh(lock: &table->tb6_lock); |
612 | if (res <= 0) { |
613 | fib6_walker_unlink(net, w); |
614 | cb->args[4] = 0; |
615 | } |
616 | } |
617 | |
618 | return res; |
619 | } |
620 | |
621 | static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) |
622 | { |
623 | struct rt6_rtnl_dump_arg arg = { .filter.dump_exceptions = true, |
624 | .filter.dump_routes = true }; |
625 | const struct nlmsghdr *nlh = cb->nlh; |
626 | struct net *net = sock_net(sk: skb->sk); |
627 | unsigned int h, s_h; |
628 | unsigned int e = 0, s_e; |
629 | struct fib6_walker *w; |
630 | struct fib6_table *tb; |
631 | struct hlist_head *head; |
632 | int res = 0; |
633 | |
634 | if (cb->strict_check) { |
635 | int err; |
636 | |
637 | err = ip_valid_fib_dump_req(net, nlh, filter: &arg.filter, cb); |
638 | if (err < 0) |
639 | return err; |
640 | } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { |
641 | struct rtmsg *rtm = nlmsg_data(nlh); |
642 | |
643 | if (rtm->rtm_flags & RTM_F_PREFIX) |
644 | arg.filter.flags = RTM_F_PREFIX; |
645 | } |
646 | |
647 | w = (void *)cb->args[2]; |
648 | if (!w) { |
649 | /* New dump: |
650 | * |
651 | * 1. hook callback destructor. |
652 | */ |
653 | cb->args[3] = (long)cb->done; |
654 | cb->done = fib6_dump_done; |
655 | |
656 | /* |
657 | * 2. allocate and initialize walker. |
658 | */ |
659 | w = kzalloc(size: sizeof(*w), GFP_ATOMIC); |
660 | if (!w) |
661 | return -ENOMEM; |
662 | w->func = fib6_dump_node; |
663 | cb->args[2] = (long)w; |
664 | } |
665 | |
666 | arg.skb = skb; |
667 | arg.cb = cb; |
668 | arg.net = net; |
669 | w->args = &arg; |
670 | |
671 | if (arg.filter.table_id) { |
672 | tb = fib6_get_table(net, arg.filter.table_id); |
673 | if (!tb) { |
674 | if (rtnl_msg_family(nlh: cb->nlh) != PF_INET6) |
675 | goto out; |
676 | |
677 | NL_SET_ERR_MSG_MOD(cb->extack, "FIB table does not exist" ); |
678 | return -ENOENT; |
679 | } |
680 | |
681 | if (!cb->args[0]) { |
682 | res = fib6_dump_table(table: tb, skb, cb); |
683 | if (!res) |
684 | cb->args[0] = 1; |
685 | } |
686 | goto out; |
687 | } |
688 | |
689 | s_h = cb->args[0]; |
690 | s_e = cb->args[1]; |
691 | |
692 | rcu_read_lock(); |
693 | for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { |
694 | e = 0; |
695 | head = &net->ipv6.fib_table_hash[h]; |
696 | hlist_for_each_entry_rcu(tb, head, tb6_hlist) { |
697 | if (e < s_e) |
698 | goto next; |
699 | res = fib6_dump_table(table: tb, skb, cb); |
700 | if (res != 0) |
701 | goto out_unlock; |
702 | next: |
703 | e++; |
704 | } |
705 | } |
706 | out_unlock: |
707 | rcu_read_unlock(); |
708 | cb->args[1] = e; |
709 | cb->args[0] = h; |
710 | out: |
711 | res = res < 0 ? res : skb->len; |
712 | if (res <= 0) |
713 | fib6_dump_end(cb); |
714 | return res; |
715 | } |
716 | |
717 | void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val) |
718 | { |
719 | if (!f6i) |
720 | return; |
721 | |
722 | if (f6i->fib6_metrics == &dst_default_metrics) { |
723 | struct dst_metrics *p = kzalloc(size: sizeof(*p), GFP_ATOMIC); |
724 | |
725 | if (!p) |
726 | return; |
727 | |
728 | refcount_set(r: &p->refcnt, n: 1); |
729 | f6i->fib6_metrics = p; |
730 | } |
731 | |
732 | f6i->fib6_metrics->metrics[metric - 1] = val; |
733 | } |
734 | |
735 | /* |
736 | * Routing Table |
737 | * |
738 | * return the appropriate node for a routing tree "add" operation |
739 | * by either creating and inserting or by returning an existing |
740 | * node. |
741 | */ |
742 | |
743 | static struct fib6_node *fib6_add_1(struct net *net, |
744 | struct fib6_table *table, |
745 | struct fib6_node *root, |
746 | struct in6_addr *addr, int plen, |
747 | int offset, int allow_create, |
748 | int replace_required, |
749 | struct netlink_ext_ack *extack) |
750 | { |
751 | struct fib6_node *fn, *in, *ln; |
752 | struct fib6_node *pn = NULL; |
753 | struct rt6key *key; |
754 | int bit; |
755 | __be32 dir = 0; |
756 | |
757 | RT6_TRACE("fib6_add_1\n" ); |
758 | |
759 | /* insert node in tree */ |
760 | |
761 | fn = root; |
762 | |
763 | do { |
764 | struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, |
765 | lockdep_is_held(&table->tb6_lock)); |
766 | key = (struct rt6key *)((u8 *)leaf + offset); |
767 | |
768 | /* |
769 | * Prefix match |
770 | */ |
771 | if (plen < fn->fn_bit || |
772 | !ipv6_prefix_equal(addr1: &key->addr, addr2: addr, prefixlen: fn->fn_bit)) { |
773 | if (!allow_create) { |
774 | if (replace_required) { |
775 | NL_SET_ERR_MSG(extack, |
776 | "Can not replace route - no match found" ); |
777 | pr_warn("Can't replace route, no match found\n" ); |
778 | return ERR_PTR(error: -ENOENT); |
779 | } |
780 | pr_warn("NLM_F_CREATE should be set when creating new route\n" ); |
781 | } |
782 | goto insert_above; |
783 | } |
784 | |
785 | /* |
786 | * Exact match ? |
787 | */ |
788 | |
789 | if (plen == fn->fn_bit) { |
790 | /* clean up an intermediate node */ |
791 | if (!(fn->fn_flags & RTN_RTINFO)) { |
792 | RCU_INIT_POINTER(fn->leaf, NULL); |
793 | fib6_info_release(f6i: leaf); |
794 | /* remove null_entry in the root node */ |
795 | } else if (fn->fn_flags & RTN_TL_ROOT && |
796 | rcu_access_pointer(fn->leaf) == |
797 | net->ipv6.fib6_null_entry) { |
798 | RCU_INIT_POINTER(fn->leaf, NULL); |
799 | } |
800 | |
801 | return fn; |
802 | } |
803 | |
804 | /* |
805 | * We have more bits to go |
806 | */ |
807 | |
808 | /* Try to walk down on tree. */ |
809 | dir = addr_bit_set(token: addr, fn_bit: fn->fn_bit); |
810 | pn = fn; |
811 | fn = dir ? |
812 | rcu_dereference_protected(fn->right, |
813 | lockdep_is_held(&table->tb6_lock)) : |
814 | rcu_dereference_protected(fn->left, |
815 | lockdep_is_held(&table->tb6_lock)); |
816 | } while (fn); |
817 | |
818 | if (!allow_create) { |
819 | /* We should not create new node because |
820 | * NLM_F_REPLACE was specified without NLM_F_CREATE |
821 | * I assume it is safe to require NLM_F_CREATE when |
822 | * REPLACE flag is used! Later we may want to remove the |
823 | * check for replace_required, because according |
824 | * to netlink specification, NLM_F_CREATE |
825 | * MUST be specified if new route is created. |
826 | * That would keep IPv6 consistent with IPv4 |
827 | */ |
828 | if (replace_required) { |
829 | NL_SET_ERR_MSG(extack, |
830 | "Can not replace route - no match found" ); |
831 | pr_warn("Can't replace route, no match found\n" ); |
832 | return ERR_PTR(error: -ENOENT); |
833 | } |
834 | pr_warn("NLM_F_CREATE should be set when creating new route\n" ); |
835 | } |
836 | /* |
837 | * We walked to the bottom of tree. |
838 | * Create new leaf node without children. |
839 | */ |
840 | |
841 | ln = node_alloc(net); |
842 | |
843 | if (!ln) |
844 | return ERR_PTR(error: -ENOMEM); |
845 | ln->fn_bit = plen; |
846 | RCU_INIT_POINTER(ln->parent, pn); |
847 | |
848 | if (dir) |
849 | rcu_assign_pointer(pn->right, ln); |
850 | else |
851 | rcu_assign_pointer(pn->left, ln); |
852 | |
853 | return ln; |
854 | |
855 | |
856 | insert_above: |
857 | /* |
858 | * split since we don't have a common prefix anymore or |
859 | * we have a less significant route. |
860 | * we've to insert an intermediate node on the list |
861 | * this new node will point to the one we need to create |
862 | * and the current |
863 | */ |
864 | |
865 | pn = rcu_dereference_protected(fn->parent, |
866 | lockdep_is_held(&table->tb6_lock)); |
867 | |
868 | /* find 1st bit in difference between the 2 addrs. |
869 | |
870 | See comment in __ipv6_addr_diff: bit may be an invalid value, |
871 | but if it is >= plen, the value is ignored in any case. |
872 | */ |
873 | |
874 | bit = __ipv6_addr_diff(token1: addr, token2: &key->addr, addrlen: sizeof(*addr)); |
875 | |
876 | /* |
877 | * (intermediate)[in] |
878 | * / \ |
879 | * (new leaf node)[ln] (old node)[fn] |
880 | */ |
881 | if (plen > bit) { |
882 | in = node_alloc(net); |
883 | ln = node_alloc(net); |
884 | |
885 | if (!in || !ln) { |
886 | if (in) |
887 | node_free_immediate(net, fn: in); |
888 | if (ln) |
889 | node_free_immediate(net, fn: ln); |
890 | return ERR_PTR(error: -ENOMEM); |
891 | } |
892 | |
893 | /* |
894 | * new intermediate node. |
895 | * RTN_RTINFO will |
896 | * be off since that an address that chooses one of |
897 | * the branches would not match less specific routes |
898 | * in the other branch |
899 | */ |
900 | |
901 | in->fn_bit = bit; |
902 | |
903 | RCU_INIT_POINTER(in->parent, pn); |
904 | in->leaf = fn->leaf; |
905 | fib6_info_hold(rcu_dereference_protected(in->leaf, |
906 | lockdep_is_held(&table->tb6_lock))); |
907 | |
908 | /* update parent pointer */ |
909 | if (dir) |
910 | rcu_assign_pointer(pn->right, in); |
911 | else |
912 | rcu_assign_pointer(pn->left, in); |
913 | |
914 | ln->fn_bit = plen; |
915 | |
916 | RCU_INIT_POINTER(ln->parent, in); |
917 | rcu_assign_pointer(fn->parent, in); |
918 | |
919 | if (addr_bit_set(token: addr, fn_bit: bit)) { |
920 | rcu_assign_pointer(in->right, ln); |
921 | rcu_assign_pointer(in->left, fn); |
922 | } else { |
923 | rcu_assign_pointer(in->left, ln); |
924 | rcu_assign_pointer(in->right, fn); |
925 | } |
926 | } else { /* plen <= bit */ |
927 | |
928 | /* |
929 | * (new leaf node)[ln] |
930 | * / \ |
931 | * (old node)[fn] NULL |
932 | */ |
933 | |
934 | ln = node_alloc(net); |
935 | |
936 | if (!ln) |
937 | return ERR_PTR(error: -ENOMEM); |
938 | |
939 | ln->fn_bit = plen; |
940 | |
941 | RCU_INIT_POINTER(ln->parent, pn); |
942 | |
943 | if (addr_bit_set(token: &key->addr, fn_bit: plen)) |
944 | RCU_INIT_POINTER(ln->right, fn); |
945 | else |
946 | RCU_INIT_POINTER(ln->left, fn); |
947 | |
948 | rcu_assign_pointer(fn->parent, ln); |
949 | |
950 | if (dir) |
951 | rcu_assign_pointer(pn->right, ln); |
952 | else |
953 | rcu_assign_pointer(pn->left, ln); |
954 | } |
955 | return ln; |
956 | } |
957 | |
958 | static void __fib6_drop_pcpu_from(struct fib6_nh *fib6_nh, |
959 | const struct fib6_info *match, |
960 | const struct fib6_table *table) |
961 | { |
962 | int cpu; |
963 | |
964 | if (!fib6_nh->rt6i_pcpu) |
965 | return; |
966 | |
967 | /* release the reference to this fib entry from |
968 | * all of its cached pcpu routes |
969 | */ |
970 | for_each_possible_cpu(cpu) { |
971 | struct rt6_info **ppcpu_rt; |
972 | struct rt6_info *pcpu_rt; |
973 | |
974 | ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu); |
975 | pcpu_rt = *ppcpu_rt; |
976 | |
977 | /* only dropping the 'from' reference if the cached route |
978 | * is using 'match'. The cached pcpu_rt->from only changes |
979 | * from a fib6_info to NULL (ip6_dst_destroy); it can never |
980 | * change from one fib6_info reference to another |
981 | */ |
982 | if (pcpu_rt && rcu_access_pointer(pcpu_rt->from) == match) { |
983 | struct fib6_info *from; |
984 | |
985 | from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL); |
986 | fib6_info_release(f6i: from); |
987 | } |
988 | } |
989 | } |
990 | |
991 | struct fib6_nh_pcpu_arg { |
992 | struct fib6_info *from; |
993 | const struct fib6_table *table; |
994 | }; |
995 | |
996 | static int fib6_nh_drop_pcpu_from(struct fib6_nh *nh, void *_arg) |
997 | { |
998 | struct fib6_nh_pcpu_arg *arg = _arg; |
999 | |
1000 | __fib6_drop_pcpu_from(fib6_nh: nh, match: arg->from, table: arg->table); |
1001 | return 0; |
1002 | } |
1003 | |
1004 | static void fib6_drop_pcpu_from(struct fib6_info *f6i, |
1005 | const struct fib6_table *table) |
1006 | { |
1007 | /* Make sure rt6_make_pcpu_route() wont add other percpu routes |
1008 | * while we are cleaning them here. |
1009 | */ |
1010 | f6i->fib6_destroying = 1; |
1011 | mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */ |
1012 | |
1013 | if (f6i->nh) { |
1014 | struct fib6_nh_pcpu_arg arg = { |
1015 | .from = f6i, |
1016 | .table = table |
1017 | }; |
1018 | |
1019 | nexthop_for_each_fib6_nh(nh: f6i->nh, cb: fib6_nh_drop_pcpu_from, |
1020 | arg: &arg); |
1021 | } else { |
1022 | struct fib6_nh *fib6_nh; |
1023 | |
1024 | fib6_nh = f6i->fib6_nh; |
1025 | __fib6_drop_pcpu_from(fib6_nh, match: f6i, table); |
1026 | } |
1027 | } |
1028 | |
1029 | static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn, |
1030 | struct net *net) |
1031 | { |
1032 | struct fib6_table *table = rt->fib6_table; |
1033 | |
1034 | /* Flush all cached dst in exception table */ |
1035 | rt6_flush_exceptions(f6i: rt); |
1036 | fib6_drop_pcpu_from(f6i: rt, table); |
1037 | |
1038 | if (rt->nh && !list_empty(head: &rt->nh_list)) |
1039 | list_del_init(entry: &rt->nh_list); |
1040 | |
1041 | if (refcount_read(r: &rt->fib6_ref) != 1) { |
1042 | /* This route is used as dummy address holder in some split |
1043 | * nodes. It is not leaked, but it still holds other resources, |
1044 | * which must be released in time. So, scan ascendant nodes |
1045 | * and replace dummy references to this route with references |
1046 | * to still alive ones. |
1047 | */ |
1048 | while (fn) { |
1049 | struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, |
1050 | lockdep_is_held(&table->tb6_lock)); |
1051 | struct fib6_info *new_leaf; |
1052 | if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) { |
1053 | new_leaf = fib6_find_prefix(net, table, fn); |
1054 | fib6_info_hold(f6i: new_leaf); |
1055 | |
1056 | rcu_assign_pointer(fn->leaf, new_leaf); |
1057 | fib6_info_release(f6i: rt); |
1058 | } |
1059 | fn = rcu_dereference_protected(fn->parent, |
1060 | lockdep_is_held(&table->tb6_lock)); |
1061 | } |
1062 | } |
1063 | |
1064 | fib6_clean_expires_locked(f6i: rt); |
1065 | } |
1066 | |
1067 | /* |
1068 | * Insert routing information in a node. |
1069 | */ |
1070 | |
1071 | static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, |
1072 | struct nl_info *info, |
1073 | struct netlink_ext_ack *extack) |
1074 | { |
1075 | struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, |
1076 | lockdep_is_held(&rt->fib6_table->tb6_lock)); |
1077 | struct fib6_info *iter = NULL; |
1078 | struct fib6_info __rcu **ins; |
1079 | struct fib6_info __rcu **fallback_ins = NULL; |
1080 | int replace = (info->nlh && |
1081 | (info->nlh->nlmsg_flags & NLM_F_REPLACE)); |
1082 | int add = (!info->nlh || |
1083 | (info->nlh->nlmsg_flags & NLM_F_CREATE)); |
1084 | int found = 0; |
1085 | bool rt_can_ecmp = rt6_qualify_for_ecmp(f6i: rt); |
1086 | bool notify_sibling_rt = false; |
1087 | u16 nlflags = NLM_F_EXCL; |
1088 | int err; |
1089 | |
1090 | if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) |
1091 | nlflags |= NLM_F_APPEND; |
1092 | |
1093 | ins = &fn->leaf; |
1094 | |
1095 | for (iter = leaf; iter; |
1096 | iter = rcu_dereference_protected(iter->fib6_next, |
1097 | lockdep_is_held(&rt->fib6_table->tb6_lock))) { |
1098 | /* |
1099 | * Search for duplicates |
1100 | */ |
1101 | |
1102 | if (iter->fib6_metric == rt->fib6_metric) { |
1103 | /* |
1104 | * Same priority level |
1105 | */ |
1106 | if (info->nlh && |
1107 | (info->nlh->nlmsg_flags & NLM_F_EXCL)) |
1108 | return -EEXIST; |
1109 | |
1110 | nlflags &= ~NLM_F_EXCL; |
1111 | if (replace) { |
1112 | if (rt_can_ecmp == rt6_qualify_for_ecmp(f6i: iter)) { |
1113 | found++; |
1114 | break; |
1115 | } |
1116 | fallback_ins = fallback_ins ?: ins; |
1117 | goto next_iter; |
1118 | } |
1119 | |
1120 | if (rt6_duplicate_nexthop(a: iter, b: rt)) { |
1121 | if (rt->fib6_nsiblings) |
1122 | rt->fib6_nsiblings = 0; |
1123 | if (!(iter->fib6_flags & RTF_EXPIRES)) |
1124 | return -EEXIST; |
1125 | if (!(rt->fib6_flags & RTF_EXPIRES)) |
1126 | fib6_clean_expires_locked(f6i: iter); |
1127 | else |
1128 | fib6_set_expires_locked(f6i: iter, |
1129 | expires: rt->expires); |
1130 | |
1131 | if (rt->fib6_pmtu) |
1132 | fib6_metric_set(f6i: iter, RTAX_MTU, |
1133 | val: rt->fib6_pmtu); |
1134 | return -EEXIST; |
1135 | } |
1136 | /* If we have the same destination and the same metric, |
1137 | * but not the same gateway, then the route we try to |
1138 | * add is sibling to this route, increment our counter |
1139 | * of siblings, and later we will add our route to the |
1140 | * list. |
1141 | * Only static routes (which don't have flag |
1142 | * RTF_EXPIRES) are used for ECMPv6. |
1143 | * |
1144 | * To avoid long list, we only had siblings if the |
1145 | * route have a gateway. |
1146 | */ |
1147 | if (rt_can_ecmp && |
1148 | rt6_qualify_for_ecmp(f6i: iter)) |
1149 | rt->fib6_nsiblings++; |
1150 | } |
1151 | |
1152 | if (iter->fib6_metric > rt->fib6_metric) |
1153 | break; |
1154 | |
1155 | next_iter: |
1156 | ins = &iter->fib6_next; |
1157 | } |
1158 | |
1159 | if (fallback_ins && !found) { |
1160 | /* No matching route with same ecmp-able-ness found, replace |
1161 | * first matching route |
1162 | */ |
1163 | ins = fallback_ins; |
1164 | iter = rcu_dereference_protected(*ins, |
1165 | lockdep_is_held(&rt->fib6_table->tb6_lock)); |
1166 | found++; |
1167 | } |
1168 | |
1169 | /* Reset round-robin state, if necessary */ |
1170 | if (ins == &fn->leaf) |
1171 | fn->rr_ptr = NULL; |
1172 | |
1173 | /* Link this route to others same route. */ |
1174 | if (rt->fib6_nsiblings) { |
1175 | unsigned int fib6_nsiblings; |
1176 | struct fib6_info *sibling, *temp_sibling; |
1177 | |
1178 | /* Find the first route that have the same metric */ |
1179 | sibling = leaf; |
1180 | notify_sibling_rt = true; |
1181 | while (sibling) { |
1182 | if (sibling->fib6_metric == rt->fib6_metric && |
1183 | rt6_qualify_for_ecmp(f6i: sibling)) { |
1184 | list_add_tail(new: &rt->fib6_siblings, |
1185 | head: &sibling->fib6_siblings); |
1186 | break; |
1187 | } |
1188 | sibling = rcu_dereference_protected(sibling->fib6_next, |
1189 | lockdep_is_held(&rt->fib6_table->tb6_lock)); |
1190 | notify_sibling_rt = false; |
1191 | } |
1192 | /* For each sibling in the list, increment the counter of |
1193 | * siblings. BUG() if counters does not match, list of siblings |
1194 | * is broken! |
1195 | */ |
1196 | fib6_nsiblings = 0; |
1197 | list_for_each_entry_safe(sibling, temp_sibling, |
1198 | &rt->fib6_siblings, fib6_siblings) { |
1199 | sibling->fib6_nsiblings++; |
1200 | BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings); |
1201 | fib6_nsiblings++; |
1202 | } |
1203 | BUG_ON(fib6_nsiblings != rt->fib6_nsiblings); |
1204 | rt6_multipath_rebalance(f6i: temp_sibling); |
1205 | } |
1206 | |
1207 | /* |
1208 | * insert node |
1209 | */ |
1210 | if (!replace) { |
1211 | if (!add) |
1212 | pr_warn("NLM_F_CREATE should be set when creating new route\n" ); |
1213 | |
1214 | add: |
1215 | nlflags |= NLM_F_CREATE; |
1216 | |
1217 | /* The route should only be notified if it is the first |
1218 | * route in the node or if it is added as a sibling |
1219 | * route to the first route in the node. |
1220 | */ |
1221 | if (!info->skip_notify_kernel && |
1222 | (notify_sibling_rt || ins == &fn->leaf)) { |
1223 | enum fib_event_type fib_event; |
1224 | |
1225 | if (notify_sibling_rt) |
1226 | fib_event = FIB_EVENT_ENTRY_APPEND; |
1227 | else |
1228 | fib_event = FIB_EVENT_ENTRY_REPLACE; |
1229 | err = call_fib6_entry_notifiers(net: info->nl_net, |
1230 | event_type: fib_event, rt, |
1231 | extack); |
1232 | if (err) { |
1233 | struct fib6_info *sibling, *next_sibling; |
1234 | |
1235 | /* If the route has siblings, then it first |
1236 | * needs to be unlinked from them. |
1237 | */ |
1238 | if (!rt->fib6_nsiblings) |
1239 | return err; |
1240 | |
1241 | list_for_each_entry_safe(sibling, next_sibling, |
1242 | &rt->fib6_siblings, |
1243 | fib6_siblings) |
1244 | sibling->fib6_nsiblings--; |
1245 | rt->fib6_nsiblings = 0; |
1246 | list_del_init(entry: &rt->fib6_siblings); |
1247 | rt6_multipath_rebalance(f6i: next_sibling); |
1248 | return err; |
1249 | } |
1250 | } |
1251 | |
1252 | rcu_assign_pointer(rt->fib6_next, iter); |
1253 | fib6_info_hold(f6i: rt); |
1254 | rcu_assign_pointer(rt->fib6_node, fn); |
1255 | rcu_assign_pointer(*ins, rt); |
1256 | if (!info->skip_notify) |
1257 | inet6_rt_notify(RTM_NEWROUTE, rt, info, flags: nlflags); |
1258 | info->nl_net->ipv6.rt6_stats->fib_rt_entries++; |
1259 | |
1260 | if (!(fn->fn_flags & RTN_RTINFO)) { |
1261 | info->nl_net->ipv6.rt6_stats->fib_route_nodes++; |
1262 | fn->fn_flags |= RTN_RTINFO; |
1263 | } |
1264 | |
1265 | } else { |
1266 | int nsiblings; |
1267 | |
1268 | if (!found) { |
1269 | if (add) |
1270 | goto add; |
1271 | pr_warn("NLM_F_REPLACE set, but no existing node found!\n" ); |
1272 | return -ENOENT; |
1273 | } |
1274 | |
1275 | if (!info->skip_notify_kernel && ins == &fn->leaf) { |
1276 | err = call_fib6_entry_notifiers(net: info->nl_net, |
1277 | event_type: FIB_EVENT_ENTRY_REPLACE, |
1278 | rt, extack); |
1279 | if (err) |
1280 | return err; |
1281 | } |
1282 | |
1283 | fib6_info_hold(f6i: rt); |
1284 | rcu_assign_pointer(rt->fib6_node, fn); |
1285 | rt->fib6_next = iter->fib6_next; |
1286 | rcu_assign_pointer(*ins, rt); |
1287 | if (!info->skip_notify) |
1288 | inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); |
1289 | if (!(fn->fn_flags & RTN_RTINFO)) { |
1290 | info->nl_net->ipv6.rt6_stats->fib_route_nodes++; |
1291 | fn->fn_flags |= RTN_RTINFO; |
1292 | } |
1293 | nsiblings = iter->fib6_nsiblings; |
1294 | iter->fib6_node = NULL; |
1295 | fib6_purge_rt(rt: iter, fn, net: info->nl_net); |
1296 | if (rcu_access_pointer(fn->rr_ptr) == iter) |
1297 | fn->rr_ptr = NULL; |
1298 | fib6_info_release(f6i: iter); |
1299 | |
1300 | if (nsiblings) { |
1301 | /* Replacing an ECMP route, remove all siblings */ |
1302 | ins = &rt->fib6_next; |
1303 | iter = rcu_dereference_protected(*ins, |
1304 | lockdep_is_held(&rt->fib6_table->tb6_lock)); |
1305 | while (iter) { |
1306 | if (iter->fib6_metric > rt->fib6_metric) |
1307 | break; |
1308 | if (rt6_qualify_for_ecmp(f6i: iter)) { |
1309 | *ins = iter->fib6_next; |
1310 | iter->fib6_node = NULL; |
1311 | fib6_purge_rt(rt: iter, fn, net: info->nl_net); |
1312 | if (rcu_access_pointer(fn->rr_ptr) == iter) |
1313 | fn->rr_ptr = NULL; |
1314 | fib6_info_release(f6i: iter); |
1315 | nsiblings--; |
1316 | info->nl_net->ipv6.rt6_stats->fib_rt_entries--; |
1317 | } else { |
1318 | ins = &iter->fib6_next; |
1319 | } |
1320 | iter = rcu_dereference_protected(*ins, |
1321 | lockdep_is_held(&rt->fib6_table->tb6_lock)); |
1322 | } |
1323 | WARN_ON(nsiblings != 0); |
1324 | } |
1325 | } |
1326 | |
1327 | return 0; |
1328 | } |
1329 | |
1330 | static void fib6_start_gc(struct net *net, struct fib6_info *rt) |
1331 | { |
1332 | if (!timer_pending(timer: &net->ipv6.ip6_fib_timer) && |
1333 | (rt->fib6_flags & RTF_EXPIRES)) |
1334 | mod_timer(timer: &net->ipv6.ip6_fib_timer, |
1335 | expires: jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); |
1336 | } |
1337 | |
1338 | void fib6_force_start_gc(struct net *net) |
1339 | { |
1340 | if (!timer_pending(timer: &net->ipv6.ip6_fib_timer)) |
1341 | mod_timer(timer: &net->ipv6.ip6_fib_timer, |
1342 | expires: jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); |
1343 | } |
1344 | |
1345 | static void __fib6_update_sernum_upto_root(struct fib6_info *rt, |
1346 | int sernum) |
1347 | { |
1348 | struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, |
1349 | lockdep_is_held(&rt->fib6_table->tb6_lock)); |
1350 | |
1351 | /* paired with smp_rmb() in fib6_get_cookie_safe() */ |
1352 | smp_wmb(); |
1353 | while (fn) { |
1354 | WRITE_ONCE(fn->fn_sernum, sernum); |
1355 | fn = rcu_dereference_protected(fn->parent, |
1356 | lockdep_is_held(&rt->fib6_table->tb6_lock)); |
1357 | } |
1358 | } |
1359 | |
1360 | void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt) |
1361 | { |
1362 | __fib6_update_sernum_upto_root(rt, sernum: fib6_new_sernum(net)); |
1363 | } |
1364 | |
1365 | /* allow ipv4 to update sernum via ipv6_stub */ |
1366 | void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i) |
1367 | { |
1368 | spin_lock_bh(lock: &f6i->fib6_table->tb6_lock); |
1369 | fib6_update_sernum_upto_root(net, rt: f6i); |
1370 | spin_unlock_bh(lock: &f6i->fib6_table->tb6_lock); |
1371 | } |
1372 | |
1373 | /* |
1374 | * Add routing information to the routing tree. |
1375 | * <destination addr>/<source addr> |
1376 | * with source addr info in sub-trees |
1377 | * Need to own table->tb6_lock |
1378 | */ |
1379 | |
1380 | int fib6_add(struct fib6_node *root, struct fib6_info *rt, |
1381 | struct nl_info *info, struct netlink_ext_ack *extack) |
1382 | { |
1383 | struct fib6_table *table = rt->fib6_table; |
1384 | struct fib6_node *fn, *pn = NULL; |
1385 | int err = -ENOMEM; |
1386 | int allow_create = 1; |
1387 | int replace_required = 0; |
1388 | |
1389 | if (info->nlh) { |
1390 | if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) |
1391 | allow_create = 0; |
1392 | if (info->nlh->nlmsg_flags & NLM_F_REPLACE) |
1393 | replace_required = 1; |
1394 | } |
1395 | if (!allow_create && !replace_required) |
1396 | pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n" ); |
1397 | |
1398 | fn = fib6_add_1(net: info->nl_net, table, root, |
1399 | addr: &rt->fib6_dst.addr, plen: rt->fib6_dst.plen, |
1400 | offsetof(struct fib6_info, fib6_dst), allow_create, |
1401 | replace_required, extack); |
1402 | if (IS_ERR(ptr: fn)) { |
1403 | err = PTR_ERR(ptr: fn); |
1404 | fn = NULL; |
1405 | goto out; |
1406 | } |
1407 | |
1408 | pn = fn; |
1409 | |
1410 | #ifdef CONFIG_IPV6_SUBTREES |
1411 | if (rt->fib6_src.plen) { |
1412 | struct fib6_node *sn; |
1413 | |
1414 | if (!rcu_access_pointer(fn->subtree)) { |
1415 | struct fib6_node *sfn; |
1416 | |
1417 | /* |
1418 | * Create subtree. |
1419 | * |
1420 | * fn[main tree] |
1421 | * | |
1422 | * sfn[subtree root] |
1423 | * \ |
1424 | * sn[new leaf node] |
1425 | */ |
1426 | |
1427 | /* Create subtree root node */ |
1428 | sfn = node_alloc(net: info->nl_net); |
1429 | if (!sfn) |
1430 | goto failure; |
1431 | |
1432 | fib6_info_hold(f6i: info->nl_net->ipv6.fib6_null_entry); |
1433 | rcu_assign_pointer(sfn->leaf, |
1434 | info->nl_net->ipv6.fib6_null_entry); |
1435 | sfn->fn_flags = RTN_ROOT; |
1436 | |
1437 | /* Now add the first leaf node to new subtree */ |
1438 | |
1439 | sn = fib6_add_1(net: info->nl_net, table, root: sfn, |
1440 | addr: &rt->fib6_src.addr, plen: rt->fib6_src.plen, |
1441 | offsetof(struct fib6_info, fib6_src), |
1442 | allow_create, replace_required, extack); |
1443 | |
1444 | if (IS_ERR(ptr: sn)) { |
1445 | /* If it is failed, discard just allocated |
1446 | root, and then (in failure) stale node |
1447 | in main tree. |
1448 | */ |
1449 | node_free_immediate(net: info->nl_net, fn: sfn); |
1450 | err = PTR_ERR(ptr: sn); |
1451 | goto failure; |
1452 | } |
1453 | |
1454 | /* Now link new subtree to main tree */ |
1455 | rcu_assign_pointer(sfn->parent, fn); |
1456 | rcu_assign_pointer(fn->subtree, sfn); |
1457 | } else { |
1458 | sn = fib6_add_1(net: info->nl_net, table, FIB6_SUBTREE(fn), |
1459 | addr: &rt->fib6_src.addr, plen: rt->fib6_src.plen, |
1460 | offsetof(struct fib6_info, fib6_src), |
1461 | allow_create, replace_required, extack); |
1462 | |
1463 | if (IS_ERR(ptr: sn)) { |
1464 | err = PTR_ERR(ptr: sn); |
1465 | goto failure; |
1466 | } |
1467 | } |
1468 | |
1469 | if (!rcu_access_pointer(fn->leaf)) { |
1470 | if (fn->fn_flags & RTN_TL_ROOT) { |
1471 | /* put back null_entry for root node */ |
1472 | rcu_assign_pointer(fn->leaf, |
1473 | info->nl_net->ipv6.fib6_null_entry); |
1474 | } else { |
1475 | fib6_info_hold(f6i: rt); |
1476 | rcu_assign_pointer(fn->leaf, rt); |
1477 | } |
1478 | } |
1479 | fn = sn; |
1480 | } |
1481 | #endif |
1482 | |
1483 | err = fib6_add_rt2node(fn, rt, info, extack); |
1484 | if (!err) { |
1485 | if (rt->nh) |
1486 | list_add(new: &rt->nh_list, head: &rt->nh->f6i_list); |
1487 | __fib6_update_sernum_upto_root(rt, sernum: fib6_new_sernum(net: info->nl_net)); |
1488 | |
1489 | if (fib6_has_expires(f6i: rt)) |
1490 | hlist_add_head(n: &rt->gc_link, h: &table->tb6_gc_hlist); |
1491 | |
1492 | fib6_start_gc(net: info->nl_net, rt); |
1493 | } |
1494 | |
1495 | out: |
1496 | if (err) { |
1497 | #ifdef CONFIG_IPV6_SUBTREES |
1498 | /* |
1499 | * If fib6_add_1 has cleared the old leaf pointer in the |
1500 | * super-tree leaf node we have to find a new one for it. |
1501 | */ |
1502 | if (pn != fn) { |
1503 | struct fib6_info *pn_leaf = |
1504 | rcu_dereference_protected(pn->leaf, |
1505 | lockdep_is_held(&table->tb6_lock)); |
1506 | if (pn_leaf == rt) { |
1507 | pn_leaf = NULL; |
1508 | RCU_INIT_POINTER(pn->leaf, NULL); |
1509 | fib6_info_release(f6i: rt); |
1510 | } |
1511 | if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { |
1512 | pn_leaf = fib6_find_prefix(net: info->nl_net, table, |
1513 | fn: pn); |
1514 | #if RT6_DEBUG >= 2 |
1515 | if (!pn_leaf) { |
1516 | WARN_ON(!pn_leaf); |
1517 | pn_leaf = |
1518 | info->nl_net->ipv6.fib6_null_entry; |
1519 | } |
1520 | #endif |
1521 | fib6_info_hold(f6i: pn_leaf); |
1522 | rcu_assign_pointer(pn->leaf, pn_leaf); |
1523 | } |
1524 | } |
1525 | #endif |
1526 | goto failure; |
1527 | } else if (fib6_requires_src(rt)) { |
1528 | fib6_routes_require_src_inc(net: info->nl_net); |
1529 | } |
1530 | return err; |
1531 | |
1532 | failure: |
1533 | /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: |
1534 | * 1. fn is an intermediate node and we failed to add the new |
1535 | * route to it in both subtree creation failure and fib6_add_rt2node() |
1536 | * failure case. |
1537 | * 2. fn is the root node in the table and we fail to add the first |
1538 | * default route to it. |
1539 | */ |
1540 | if (fn && |
1541 | (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || |
1542 | (fn->fn_flags & RTN_TL_ROOT && |
1543 | !rcu_access_pointer(fn->leaf)))) |
1544 | fib6_repair_tree(net: info->nl_net, table, fn); |
1545 | return err; |
1546 | } |
1547 | |
1548 | /* |
1549 | * Routing tree lookup |
1550 | * |
1551 | */ |
1552 | |
1553 | struct lookup_args { |
1554 | int offset; /* key offset on fib6_info */ |
1555 | const struct in6_addr *addr; /* search key */ |
1556 | }; |
1557 | |
1558 | static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root, |
1559 | struct lookup_args *args) |
1560 | { |
1561 | struct fib6_node *fn; |
1562 | __be32 dir; |
1563 | |
1564 | if (unlikely(args->offset == 0)) |
1565 | return NULL; |
1566 | |
1567 | /* |
1568 | * Descend on a tree |
1569 | */ |
1570 | |
1571 | fn = root; |
1572 | |
1573 | for (;;) { |
1574 | struct fib6_node *next; |
1575 | |
1576 | dir = addr_bit_set(token: args->addr, fn_bit: fn->fn_bit); |
1577 | |
1578 | next = dir ? rcu_dereference(fn->right) : |
1579 | rcu_dereference(fn->left); |
1580 | |
1581 | if (next) { |
1582 | fn = next; |
1583 | continue; |
1584 | } |
1585 | break; |
1586 | } |
1587 | |
1588 | while (fn) { |
1589 | struct fib6_node *subtree = FIB6_SUBTREE(fn); |
1590 | |
1591 | if (subtree || fn->fn_flags & RTN_RTINFO) { |
1592 | struct fib6_info *leaf = rcu_dereference(fn->leaf); |
1593 | struct rt6key *key; |
1594 | |
1595 | if (!leaf) |
1596 | goto backtrack; |
1597 | |
1598 | key = (struct rt6key *) ((u8 *)leaf + args->offset); |
1599 | |
1600 | if (ipv6_prefix_equal(addr1: &key->addr, addr2: args->addr, prefixlen: key->plen)) { |
1601 | #ifdef CONFIG_IPV6_SUBTREES |
1602 | if (subtree) { |
1603 | struct fib6_node *sfn; |
1604 | sfn = fib6_node_lookup_1(root: subtree, |
1605 | args: args + 1); |
1606 | if (!sfn) |
1607 | goto backtrack; |
1608 | fn = sfn; |
1609 | } |
1610 | #endif |
1611 | if (fn->fn_flags & RTN_RTINFO) |
1612 | return fn; |
1613 | } |
1614 | } |
1615 | backtrack: |
1616 | if (fn->fn_flags & RTN_ROOT) |
1617 | break; |
1618 | |
1619 | fn = rcu_dereference(fn->parent); |
1620 | } |
1621 | |
1622 | return NULL; |
1623 | } |
1624 | |
1625 | /* called with rcu_read_lock() held |
1626 | */ |
1627 | struct fib6_node *fib6_node_lookup(struct fib6_node *root, |
1628 | const struct in6_addr *daddr, |
1629 | const struct in6_addr *saddr) |
1630 | { |
1631 | struct fib6_node *fn; |
1632 | struct lookup_args args[] = { |
1633 | { |
1634 | .offset = offsetof(struct fib6_info, fib6_dst), |
1635 | .addr = daddr, |
1636 | }, |
1637 | #ifdef CONFIG_IPV6_SUBTREES |
1638 | { |
1639 | .offset = offsetof(struct fib6_info, fib6_src), |
1640 | .addr = saddr, |
1641 | }, |
1642 | #endif |
1643 | { |
1644 | .offset = 0, /* sentinel */ |
1645 | } |
1646 | }; |
1647 | |
1648 | fn = fib6_node_lookup_1(root, args: daddr ? args : args + 1); |
1649 | if (!fn || fn->fn_flags & RTN_TL_ROOT) |
1650 | fn = root; |
1651 | |
1652 | return fn; |
1653 | } |
1654 | |
1655 | /* |
1656 | * Get node with specified destination prefix (and source prefix, |
1657 | * if subtrees are used) |
1658 | * exact_match == true means we try to find fn with exact match of |
1659 | * the passed in prefix addr |
1660 | * exact_match == false means we try to find fn with longest prefix |
1661 | * match of the passed in prefix addr. This is useful for finding fn |
1662 | * for cached route as it will be stored in the exception table under |
1663 | * the node with longest prefix length. |
1664 | */ |
1665 | |
1666 | |
1667 | static struct fib6_node *fib6_locate_1(struct fib6_node *root, |
1668 | const struct in6_addr *addr, |
1669 | int plen, int offset, |
1670 | bool exact_match) |
1671 | { |
1672 | struct fib6_node *fn, *prev = NULL; |
1673 | |
1674 | for (fn = root; fn ; ) { |
1675 | struct fib6_info *leaf = rcu_dereference(fn->leaf); |
1676 | struct rt6key *key; |
1677 | |
1678 | /* This node is being deleted */ |
1679 | if (!leaf) { |
1680 | if (plen <= fn->fn_bit) |
1681 | goto out; |
1682 | else |
1683 | goto next; |
1684 | } |
1685 | |
1686 | key = (struct rt6key *)((u8 *)leaf + offset); |
1687 | |
1688 | /* |
1689 | * Prefix match |
1690 | */ |
1691 | if (plen < fn->fn_bit || |
1692 | !ipv6_prefix_equal(addr1: &key->addr, addr2: addr, prefixlen: fn->fn_bit)) |
1693 | goto out; |
1694 | |
1695 | if (plen == fn->fn_bit) |
1696 | return fn; |
1697 | |
1698 | if (fn->fn_flags & RTN_RTINFO) |
1699 | prev = fn; |
1700 | |
1701 | next: |
1702 | /* |
1703 | * We have more bits to go |
1704 | */ |
1705 | if (addr_bit_set(token: addr, fn_bit: fn->fn_bit)) |
1706 | fn = rcu_dereference(fn->right); |
1707 | else |
1708 | fn = rcu_dereference(fn->left); |
1709 | } |
1710 | out: |
1711 | if (exact_match) |
1712 | return NULL; |
1713 | else |
1714 | return prev; |
1715 | } |
1716 | |
1717 | struct fib6_node *fib6_locate(struct fib6_node *root, |
1718 | const struct in6_addr *daddr, int dst_len, |
1719 | const struct in6_addr *saddr, int src_len, |
1720 | bool exact_match) |
1721 | { |
1722 | struct fib6_node *fn; |
1723 | |
1724 | fn = fib6_locate_1(root, addr: daddr, plen: dst_len, |
1725 | offsetof(struct fib6_info, fib6_dst), |
1726 | exact_match); |
1727 | |
1728 | #ifdef CONFIG_IPV6_SUBTREES |
1729 | if (src_len) { |
1730 | WARN_ON(saddr == NULL); |
1731 | if (fn) { |
1732 | struct fib6_node *subtree = FIB6_SUBTREE(fn); |
1733 | |
1734 | if (subtree) { |
1735 | fn = fib6_locate_1(root: subtree, addr: saddr, plen: src_len, |
1736 | offsetof(struct fib6_info, fib6_src), |
1737 | exact_match); |
1738 | } |
1739 | } |
1740 | } |
1741 | #endif |
1742 | |
1743 | if (fn && fn->fn_flags & RTN_RTINFO) |
1744 | return fn; |
1745 | |
1746 | return NULL; |
1747 | } |
1748 | |
1749 | |
1750 | /* |
1751 | * Deletion |
1752 | * |
1753 | */ |
1754 | |
1755 | static struct fib6_info *fib6_find_prefix(struct net *net, |
1756 | struct fib6_table *table, |
1757 | struct fib6_node *fn) |
1758 | { |
1759 | struct fib6_node *child_left, *child_right; |
1760 | |
1761 | if (fn->fn_flags & RTN_ROOT) |
1762 | return net->ipv6.fib6_null_entry; |
1763 | |
1764 | while (fn) { |
1765 | child_left = rcu_dereference_protected(fn->left, |
1766 | lockdep_is_held(&table->tb6_lock)); |
1767 | child_right = rcu_dereference_protected(fn->right, |
1768 | lockdep_is_held(&table->tb6_lock)); |
1769 | if (child_left) |
1770 | return rcu_dereference_protected(child_left->leaf, |
1771 | lockdep_is_held(&table->tb6_lock)); |
1772 | if (child_right) |
1773 | return rcu_dereference_protected(child_right->leaf, |
1774 | lockdep_is_held(&table->tb6_lock)); |
1775 | |
1776 | fn = FIB6_SUBTREE(fn); |
1777 | } |
1778 | return NULL; |
1779 | } |
1780 | |
1781 | /* |
1782 | * Called to trim the tree of intermediate nodes when possible. "fn" |
1783 | * is the node we want to try and remove. |
1784 | * Need to own table->tb6_lock |
1785 | */ |
1786 | |
1787 | static struct fib6_node *fib6_repair_tree(struct net *net, |
1788 | struct fib6_table *table, |
1789 | struct fib6_node *fn) |
1790 | { |
1791 | int children; |
1792 | int nstate; |
1793 | struct fib6_node *child; |
1794 | struct fib6_walker *w; |
1795 | int iter = 0; |
1796 | |
1797 | /* Set fn->leaf to null_entry for root node. */ |
1798 | if (fn->fn_flags & RTN_TL_ROOT) { |
1799 | rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry); |
1800 | return fn; |
1801 | } |
1802 | |
1803 | for (;;) { |
1804 | struct fib6_node *fn_r = rcu_dereference_protected(fn->right, |
1805 | lockdep_is_held(&table->tb6_lock)); |
1806 | struct fib6_node *fn_l = rcu_dereference_protected(fn->left, |
1807 | lockdep_is_held(&table->tb6_lock)); |
1808 | struct fib6_node *pn = rcu_dereference_protected(fn->parent, |
1809 | lockdep_is_held(&table->tb6_lock)); |
1810 | struct fib6_node *pn_r = rcu_dereference_protected(pn->right, |
1811 | lockdep_is_held(&table->tb6_lock)); |
1812 | struct fib6_node *pn_l = rcu_dereference_protected(pn->left, |
1813 | lockdep_is_held(&table->tb6_lock)); |
1814 | struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf, |
1815 | lockdep_is_held(&table->tb6_lock)); |
1816 | struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf, |
1817 | lockdep_is_held(&table->tb6_lock)); |
1818 | struct fib6_info *new_fn_leaf; |
1819 | |
1820 | RT6_TRACE("fixing tree: plen=%d iter=%d\n" , fn->fn_bit, iter); |
1821 | iter++; |
1822 | |
1823 | WARN_ON(fn->fn_flags & RTN_RTINFO); |
1824 | WARN_ON(fn->fn_flags & RTN_TL_ROOT); |
1825 | WARN_ON(fn_leaf); |
1826 | |
1827 | children = 0; |
1828 | child = NULL; |
1829 | if (fn_r) { |
1830 | child = fn_r; |
1831 | children |= 1; |
1832 | } |
1833 | if (fn_l) { |
1834 | child = fn_l; |
1835 | children |= 2; |
1836 | } |
1837 | |
1838 | if (children == 3 || FIB6_SUBTREE(fn) |
1839 | #ifdef CONFIG_IPV6_SUBTREES |
1840 | /* Subtree root (i.e. fn) may have one child */ |
1841 | || (children && fn->fn_flags & RTN_ROOT) |
1842 | #endif |
1843 | ) { |
1844 | new_fn_leaf = fib6_find_prefix(net, table, fn); |
1845 | #if RT6_DEBUG >= 2 |
1846 | if (!new_fn_leaf) { |
1847 | WARN_ON(!new_fn_leaf); |
1848 | new_fn_leaf = net->ipv6.fib6_null_entry; |
1849 | } |
1850 | #endif |
1851 | fib6_info_hold(f6i: new_fn_leaf); |
1852 | rcu_assign_pointer(fn->leaf, new_fn_leaf); |
1853 | return pn; |
1854 | } |
1855 | |
1856 | #ifdef CONFIG_IPV6_SUBTREES |
1857 | if (FIB6_SUBTREE(pn) == fn) { |
1858 | WARN_ON(!(fn->fn_flags & RTN_ROOT)); |
1859 | RCU_INIT_POINTER(pn->subtree, NULL); |
1860 | nstate = FWS_L; |
1861 | } else { |
1862 | WARN_ON(fn->fn_flags & RTN_ROOT); |
1863 | #endif |
1864 | if (pn_r == fn) |
1865 | rcu_assign_pointer(pn->right, child); |
1866 | else if (pn_l == fn) |
1867 | rcu_assign_pointer(pn->left, child); |
1868 | #if RT6_DEBUG >= 2 |
1869 | else |
1870 | WARN_ON(1); |
1871 | #endif |
1872 | if (child) |
1873 | rcu_assign_pointer(child->parent, pn); |
1874 | nstate = FWS_R; |
1875 | #ifdef CONFIG_IPV6_SUBTREES |
1876 | } |
1877 | #endif |
1878 | |
1879 | read_lock(&net->ipv6.fib6_walker_lock); |
1880 | FOR_WALKERS(net, w) { |
1881 | if (!child) { |
1882 | if (w->node == fn) { |
1883 | RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n" , w, w->state, nstate); |
1884 | w->node = pn; |
1885 | w->state = nstate; |
1886 | } |
1887 | } else { |
1888 | if (w->node == fn) { |
1889 | w->node = child; |
1890 | if (children&2) { |
1891 | RT6_TRACE("W %p adjusted by delnode 2, s=%d\n" , w, w->state); |
1892 | w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; |
1893 | } else { |
1894 | RT6_TRACE("W %p adjusted by delnode 2, s=%d\n" , w, w->state); |
1895 | w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; |
1896 | } |
1897 | } |
1898 | } |
1899 | } |
1900 | read_unlock(&net->ipv6.fib6_walker_lock); |
1901 | |
1902 | node_free(net, fn); |
1903 | if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) |
1904 | return pn; |
1905 | |
1906 | RCU_INIT_POINTER(pn->leaf, NULL); |
1907 | fib6_info_release(f6i: pn_leaf); |
1908 | fn = pn; |
1909 | } |
1910 | } |
1911 | |
1912 | static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, |
1913 | struct fib6_info __rcu **rtp, struct nl_info *info) |
1914 | { |
1915 | struct fib6_info *leaf, *replace_rt = NULL; |
1916 | struct fib6_walker *w; |
1917 | struct fib6_info *rt = rcu_dereference_protected(*rtp, |
1918 | lockdep_is_held(&table->tb6_lock)); |
1919 | struct net *net = info->nl_net; |
1920 | bool notify_del = false; |
1921 | |
1922 | RT6_TRACE("fib6_del_route\n" ); |
1923 | |
1924 | /* If the deleted route is the first in the node and it is not part of |
1925 | * a multipath route, then we need to replace it with the next route |
1926 | * in the node, if exists. |
1927 | */ |
1928 | leaf = rcu_dereference_protected(fn->leaf, |
1929 | lockdep_is_held(&table->tb6_lock)); |
1930 | if (leaf == rt && !rt->fib6_nsiblings) { |
1931 | if (rcu_access_pointer(rt->fib6_next)) |
1932 | replace_rt = rcu_dereference_protected(rt->fib6_next, |
1933 | lockdep_is_held(&table->tb6_lock)); |
1934 | else |
1935 | notify_del = true; |
1936 | } |
1937 | |
1938 | /* Unlink it */ |
1939 | *rtp = rt->fib6_next; |
1940 | rt->fib6_node = NULL; |
1941 | net->ipv6.rt6_stats->fib_rt_entries--; |
1942 | net->ipv6.rt6_stats->fib_discarded_routes++; |
1943 | |
1944 | /* Reset round-robin state, if necessary */ |
1945 | if (rcu_access_pointer(fn->rr_ptr) == rt) |
1946 | fn->rr_ptr = NULL; |
1947 | |
1948 | /* Remove this entry from other siblings */ |
1949 | if (rt->fib6_nsiblings) { |
1950 | struct fib6_info *sibling, *next_sibling; |
1951 | |
1952 | /* The route is deleted from a multipath route. If this |
1953 | * multipath route is the first route in the node, then we need |
1954 | * to emit a delete notification. Otherwise, we need to skip |
1955 | * the notification. |
1956 | */ |
1957 | if (rt->fib6_metric == leaf->fib6_metric && |
1958 | rt6_qualify_for_ecmp(f6i: leaf)) |
1959 | notify_del = true; |
1960 | list_for_each_entry_safe(sibling, next_sibling, |
1961 | &rt->fib6_siblings, fib6_siblings) |
1962 | sibling->fib6_nsiblings--; |
1963 | rt->fib6_nsiblings = 0; |
1964 | list_del_init(entry: &rt->fib6_siblings); |
1965 | rt6_multipath_rebalance(f6i: next_sibling); |
1966 | } |
1967 | |
1968 | /* Adjust walkers */ |
1969 | read_lock(&net->ipv6.fib6_walker_lock); |
1970 | FOR_WALKERS(net, w) { |
1971 | if (w->state == FWS_C && w->leaf == rt) { |
1972 | RT6_TRACE("walker %p adjusted by delroute\n" , w); |
1973 | w->leaf = rcu_dereference_protected(rt->fib6_next, |
1974 | lockdep_is_held(&table->tb6_lock)); |
1975 | if (!w->leaf) |
1976 | w->state = FWS_U; |
1977 | } |
1978 | } |
1979 | read_unlock(&net->ipv6.fib6_walker_lock); |
1980 | |
1981 | /* If it was last route, call fib6_repair_tree() to: |
1982 | * 1. For root node, put back null_entry as how the table was created. |
1983 | * 2. For other nodes, expunge its radix tree node. |
1984 | */ |
1985 | if (!rcu_access_pointer(fn->leaf)) { |
1986 | if (!(fn->fn_flags & RTN_TL_ROOT)) { |
1987 | fn->fn_flags &= ~RTN_RTINFO; |
1988 | net->ipv6.rt6_stats->fib_route_nodes--; |
1989 | } |
1990 | fn = fib6_repair_tree(net, table, fn); |
1991 | } |
1992 | |
1993 | fib6_purge_rt(rt, fn, net); |
1994 | |
1995 | if (!info->skip_notify_kernel) { |
1996 | if (notify_del) |
1997 | call_fib6_entry_notifiers(net, event_type: FIB_EVENT_ENTRY_DEL, |
1998 | rt, NULL); |
1999 | else if (replace_rt) |
2000 | call_fib6_entry_notifiers_replace(net, rt: replace_rt); |
2001 | } |
2002 | if (!info->skip_notify) |
2003 | inet6_rt_notify(RTM_DELROUTE, rt, info, flags: 0); |
2004 | |
2005 | fib6_info_release(f6i: rt); |
2006 | } |
2007 | |
2008 | /* Need to own table->tb6_lock */ |
2009 | int fib6_del(struct fib6_info *rt, struct nl_info *info) |
2010 | { |
2011 | struct net *net = info->nl_net; |
2012 | struct fib6_info __rcu **rtp; |
2013 | struct fib6_info __rcu **rtp_next; |
2014 | struct fib6_table *table; |
2015 | struct fib6_node *fn; |
2016 | |
2017 | if (rt == net->ipv6.fib6_null_entry) |
2018 | return -ENOENT; |
2019 | |
2020 | table = rt->fib6_table; |
2021 | fn = rcu_dereference_protected(rt->fib6_node, |
2022 | lockdep_is_held(&table->tb6_lock)); |
2023 | if (!fn) |
2024 | return -ENOENT; |
2025 | |
2026 | WARN_ON(!(fn->fn_flags & RTN_RTINFO)); |
2027 | |
2028 | /* |
2029 | * Walk the leaf entries looking for ourself |
2030 | */ |
2031 | |
2032 | for (rtp = &fn->leaf; *rtp; rtp = rtp_next) { |
2033 | struct fib6_info *cur = rcu_dereference_protected(*rtp, |
2034 | lockdep_is_held(&table->tb6_lock)); |
2035 | if (rt == cur) { |
2036 | if (fib6_requires_src(rt: cur)) |
2037 | fib6_routes_require_src_dec(net: info->nl_net); |
2038 | fib6_del_route(table, fn, rtp, info); |
2039 | return 0; |
2040 | } |
2041 | rtp_next = &cur->fib6_next; |
2042 | } |
2043 | return -ENOENT; |
2044 | } |
2045 | |
2046 | /* |
2047 | * Tree traversal function. |
2048 | * |
2049 | * Certainly, it is not interrupt safe. |
2050 | * However, it is internally reenterable wrt itself and fib6_add/fib6_del. |
2051 | * It means, that we can modify tree during walking |
2052 | * and use this function for garbage collection, clone pruning, |
2053 | * cleaning tree when a device goes down etc. etc. |
2054 | * |
2055 | * It guarantees that every node will be traversed, |
2056 | * and that it will be traversed only once. |
2057 | * |
2058 | * Callback function w->func may return: |
2059 | * 0 -> continue walking. |
2060 | * positive value -> walking is suspended (used by tree dumps, |
2061 | * and probably by gc, if it will be split to several slices) |
2062 | * negative value -> terminate walking. |
2063 | * |
2064 | * The function itself returns: |
2065 | * 0 -> walk is complete. |
2066 | * >0 -> walk is incomplete (i.e. suspended) |
2067 | * <0 -> walk is terminated by an error. |
2068 | * |
2069 | * This function is called with tb6_lock held. |
2070 | */ |
2071 | |
2072 | static int fib6_walk_continue(struct fib6_walker *w) |
2073 | { |
2074 | struct fib6_node *fn, *pn, *left, *right; |
2075 | |
2076 | /* w->root should always be table->tb6_root */ |
2077 | WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT)); |
2078 | |
2079 | for (;;) { |
2080 | fn = w->node; |
2081 | if (!fn) |
2082 | return 0; |
2083 | |
2084 | switch (w->state) { |
2085 | #ifdef CONFIG_IPV6_SUBTREES |
2086 | case FWS_S: |
2087 | if (FIB6_SUBTREE(fn)) { |
2088 | w->node = FIB6_SUBTREE(fn); |
2089 | continue; |
2090 | } |
2091 | w->state = FWS_L; |
2092 | fallthrough; |
2093 | #endif |
2094 | case FWS_L: |
2095 | left = rcu_dereference_protected(fn->left, 1); |
2096 | if (left) { |
2097 | w->node = left; |
2098 | w->state = FWS_INIT; |
2099 | continue; |
2100 | } |
2101 | w->state = FWS_R; |
2102 | fallthrough; |
2103 | case FWS_R: |
2104 | right = rcu_dereference_protected(fn->right, 1); |
2105 | if (right) { |
2106 | w->node = right; |
2107 | w->state = FWS_INIT; |
2108 | continue; |
2109 | } |
2110 | w->state = FWS_C; |
2111 | w->leaf = rcu_dereference_protected(fn->leaf, 1); |
2112 | fallthrough; |
2113 | case FWS_C: |
2114 | if (w->leaf && fn->fn_flags & RTN_RTINFO) { |
2115 | int err; |
2116 | |
2117 | if (w->skip) { |
2118 | w->skip--; |
2119 | goto skip; |
2120 | } |
2121 | |
2122 | err = w->func(w); |
2123 | if (err) |
2124 | return err; |
2125 | |
2126 | w->count++; |
2127 | continue; |
2128 | } |
2129 | skip: |
2130 | w->state = FWS_U; |
2131 | fallthrough; |
2132 | case FWS_U: |
2133 | if (fn == w->root) |
2134 | return 0; |
2135 | pn = rcu_dereference_protected(fn->parent, 1); |
2136 | left = rcu_dereference_protected(pn->left, 1); |
2137 | right = rcu_dereference_protected(pn->right, 1); |
2138 | w->node = pn; |
2139 | #ifdef CONFIG_IPV6_SUBTREES |
2140 | if (FIB6_SUBTREE(pn) == fn) { |
2141 | WARN_ON(!(fn->fn_flags & RTN_ROOT)); |
2142 | w->state = FWS_L; |
2143 | continue; |
2144 | } |
2145 | #endif |
2146 | if (left == fn) { |
2147 | w->state = FWS_R; |
2148 | continue; |
2149 | } |
2150 | if (right == fn) { |
2151 | w->state = FWS_C; |
2152 | w->leaf = rcu_dereference_protected(w->node->leaf, 1); |
2153 | continue; |
2154 | } |
2155 | #if RT6_DEBUG >= 2 |
2156 | WARN_ON(1); |
2157 | #endif |
2158 | } |
2159 | } |
2160 | } |
2161 | |
2162 | static int fib6_walk(struct net *net, struct fib6_walker *w) |
2163 | { |
2164 | int res; |
2165 | |
2166 | w->state = FWS_INIT; |
2167 | w->node = w->root; |
2168 | |
2169 | fib6_walker_link(net, w); |
2170 | res = fib6_walk_continue(w); |
2171 | if (res <= 0) |
2172 | fib6_walker_unlink(net, w); |
2173 | return res; |
2174 | } |
2175 | |
2176 | static int fib6_clean_node(struct fib6_walker *w) |
2177 | { |
2178 | int res; |
2179 | struct fib6_info *rt; |
2180 | struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); |
2181 | struct nl_info info = { |
2182 | .nl_net = c->net, |
2183 | .skip_notify = c->skip_notify, |
2184 | }; |
2185 | |
2186 | if (c->sernum != FIB6_NO_SERNUM_CHANGE && |
2187 | READ_ONCE(w->node->fn_sernum) != c->sernum) |
2188 | WRITE_ONCE(w->node->fn_sernum, c->sernum); |
2189 | |
2190 | if (!c->func) { |
2191 | WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); |
2192 | w->leaf = NULL; |
2193 | return 0; |
2194 | } |
2195 | |
2196 | for_each_fib6_walker_rt(w) { |
2197 | res = c->func(rt, c->arg); |
2198 | if (res == -1) { |
2199 | w->leaf = rt; |
2200 | res = fib6_del(rt, info: &info); |
2201 | if (res) { |
2202 | #if RT6_DEBUG >= 2 |
2203 | pr_debug("%s: del failed: rt=%p@%p err=%d\n" , |
2204 | __func__, rt, |
2205 | rcu_access_pointer(rt->fib6_node), |
2206 | res); |
2207 | #endif |
2208 | continue; |
2209 | } |
2210 | return 0; |
2211 | } else if (res == -2) { |
2212 | if (WARN_ON(!rt->fib6_nsiblings)) |
2213 | continue; |
2214 | rt = list_last_entry(&rt->fib6_siblings, |
2215 | struct fib6_info, fib6_siblings); |
2216 | continue; |
2217 | } |
2218 | WARN_ON(res != 0); |
2219 | } |
2220 | w->leaf = rt; |
2221 | return 0; |
2222 | } |
2223 | |
2224 | /* |
2225 | * Convenient frontend to tree walker. |
2226 | * |
2227 | * func is called on each route. |
2228 | * It may return -2 -> skip multipath route. |
2229 | * -1 -> delete this route. |
2230 | * 0 -> continue walking |
2231 | */ |
2232 | |
2233 | static void fib6_clean_tree(struct net *net, struct fib6_node *root, |
2234 | int (*func)(struct fib6_info *, void *arg), |
2235 | int sernum, void *arg, bool skip_notify) |
2236 | { |
2237 | struct fib6_cleaner c; |
2238 | |
2239 | c.w.root = root; |
2240 | c.w.func = fib6_clean_node; |
2241 | c.w.count = 0; |
2242 | c.w.skip = 0; |
2243 | c.w.skip_in_node = 0; |
2244 | c.func = func; |
2245 | c.sernum = sernum; |
2246 | c.arg = arg; |
2247 | c.net = net; |
2248 | c.skip_notify = skip_notify; |
2249 | |
2250 | fib6_walk(net, w: &c.w); |
2251 | } |
2252 | |
2253 | static void __fib6_clean_all(struct net *net, |
2254 | int (*func)(struct fib6_info *, void *), |
2255 | int sernum, void *arg, bool skip_notify) |
2256 | { |
2257 | struct fib6_table *table; |
2258 | struct hlist_head *head; |
2259 | unsigned int h; |
2260 | |
2261 | rcu_read_lock(); |
2262 | for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { |
2263 | head = &net->ipv6.fib_table_hash[h]; |
2264 | hlist_for_each_entry_rcu(table, head, tb6_hlist) { |
2265 | spin_lock_bh(lock: &table->tb6_lock); |
2266 | fib6_clean_tree(net, root: &table->tb6_root, |
2267 | func, sernum, arg, skip_notify); |
2268 | spin_unlock_bh(lock: &table->tb6_lock); |
2269 | } |
2270 | } |
2271 | rcu_read_unlock(); |
2272 | } |
2273 | |
2274 | void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *), |
2275 | void *arg) |
2276 | { |
2277 | __fib6_clean_all(net, func, sernum: FIB6_NO_SERNUM_CHANGE, arg, skip_notify: false); |
2278 | } |
2279 | |
2280 | void fib6_clean_all_skip_notify(struct net *net, |
2281 | int (*func)(struct fib6_info *, void *), |
2282 | void *arg) |
2283 | { |
2284 | __fib6_clean_all(net, func, sernum: FIB6_NO_SERNUM_CHANGE, arg, skip_notify: true); |
2285 | } |
2286 | |
2287 | static void fib6_flush_trees(struct net *net) |
2288 | { |
2289 | int new_sernum = fib6_new_sernum(net); |
2290 | |
2291 | __fib6_clean_all(net, NULL, sernum: new_sernum, NULL, skip_notify: false); |
2292 | } |
2293 | |
2294 | /* |
2295 | * Garbage collection |
2296 | */ |
2297 | |
2298 | static int fib6_age(struct fib6_info *rt, struct fib6_gc_args *gc_args) |
2299 | { |
2300 | unsigned long now = jiffies; |
2301 | |
2302 | /* |
2303 | * check addrconf expiration here. |
2304 | * Routes are expired even if they are in use. |
2305 | */ |
2306 | |
2307 | if (fib6_has_expires(f6i: rt) && rt->expires) { |
2308 | if (time_after(now, rt->expires)) { |
2309 | RT6_TRACE("expiring %p\n" , rt); |
2310 | return -1; |
2311 | } |
2312 | gc_args->more++; |
2313 | } |
2314 | |
2315 | /* Also age clones in the exception table. |
2316 | * Note, that clones are aged out |
2317 | * only if they are not in use now. |
2318 | */ |
2319 | rt6_age_exceptions(f6i: rt, gc_args, now); |
2320 | |
2321 | return 0; |
2322 | } |
2323 | |
2324 | static void fib6_gc_table(struct net *net, |
2325 | struct fib6_table *tb6, |
2326 | struct fib6_gc_args *gc_args) |
2327 | { |
2328 | struct fib6_info *rt; |
2329 | struct hlist_node *n; |
2330 | struct nl_info info = { |
2331 | .nl_net = net, |
2332 | .skip_notify = false, |
2333 | }; |
2334 | |
2335 | hlist_for_each_entry_safe(rt, n, &tb6->tb6_gc_hlist, gc_link) |
2336 | if (fib6_age(rt, gc_args) == -1) |
2337 | fib6_del(rt, info: &info); |
2338 | } |
2339 | |
2340 | static void fib6_gc_all(struct net *net, struct fib6_gc_args *gc_args) |
2341 | { |
2342 | struct fib6_table *table; |
2343 | struct hlist_head *head; |
2344 | unsigned int h; |
2345 | |
2346 | rcu_read_lock(); |
2347 | for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { |
2348 | head = &net->ipv6.fib_table_hash[h]; |
2349 | hlist_for_each_entry_rcu(table, head, tb6_hlist) { |
2350 | spin_lock_bh(lock: &table->tb6_lock); |
2351 | fib6_gc_table(net, tb6: table, gc_args); |
2352 | spin_unlock_bh(lock: &table->tb6_lock); |
2353 | } |
2354 | } |
2355 | rcu_read_unlock(); |
2356 | } |
2357 | |
2358 | void fib6_run_gc(unsigned long expires, struct net *net, bool force) |
2359 | { |
2360 | struct fib6_gc_args gc_args; |
2361 | unsigned long now; |
2362 | |
2363 | if (force) { |
2364 | spin_lock_bh(lock: &net->ipv6.fib6_gc_lock); |
2365 | } else if (!spin_trylock_bh(lock: &net->ipv6.fib6_gc_lock)) { |
2366 | mod_timer(timer: &net->ipv6.ip6_fib_timer, expires: jiffies + HZ); |
2367 | return; |
2368 | } |
2369 | gc_args.timeout = expires ? (int)expires : |
2370 | net->ipv6.sysctl.ip6_rt_gc_interval; |
2371 | gc_args.more = 0; |
2372 | |
2373 | fib6_gc_all(net, gc_args: &gc_args); |
2374 | now = jiffies; |
2375 | net->ipv6.ip6_rt_last_gc = now; |
2376 | |
2377 | if (gc_args.more) |
2378 | mod_timer(timer: &net->ipv6.ip6_fib_timer, |
2379 | expires: round_jiffies(j: now |
2380 | + net->ipv6.sysctl.ip6_rt_gc_interval)); |
2381 | else |
2382 | del_timer(timer: &net->ipv6.ip6_fib_timer); |
2383 | spin_unlock_bh(lock: &net->ipv6.fib6_gc_lock); |
2384 | } |
2385 | |
2386 | static void fib6_gc_timer_cb(struct timer_list *t) |
2387 | { |
2388 | struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer); |
2389 | |
2390 | fib6_run_gc(expires: 0, net: arg, force: true); |
2391 | } |
2392 | |
2393 | static int __net_init fib6_net_init(struct net *net) |
2394 | { |
2395 | size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; |
2396 | int err; |
2397 | |
2398 | err = fib6_notifier_init(net); |
2399 | if (err) |
2400 | return err; |
2401 | |
2402 | /* Default to 3-tuple */ |
2403 | net->ipv6.sysctl.multipath_hash_fields = |
2404 | FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK; |
2405 | |
2406 | spin_lock_init(&net->ipv6.fib6_gc_lock); |
2407 | rwlock_init(&net->ipv6.fib6_walker_lock); |
2408 | INIT_LIST_HEAD(list: &net->ipv6.fib6_walkers); |
2409 | timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0); |
2410 | |
2411 | net->ipv6.rt6_stats = kzalloc(size: sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); |
2412 | if (!net->ipv6.rt6_stats) |
2413 | goto out_notifier; |
2414 | |
2415 | /* Avoid false sharing : Use at least a full cache line */ |
2416 | size = max_t(size_t, size, L1_CACHE_BYTES); |
2417 | |
2418 | net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); |
2419 | if (!net->ipv6.fib_table_hash) |
2420 | goto out_rt6_stats; |
2421 | |
2422 | net->ipv6.fib6_main_tbl = kzalloc(size: sizeof(*net->ipv6.fib6_main_tbl), |
2423 | GFP_KERNEL); |
2424 | if (!net->ipv6.fib6_main_tbl) |
2425 | goto out_fib_table_hash; |
2426 | |
2427 | net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; |
2428 | rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, |
2429 | net->ipv6.fib6_null_entry); |
2430 | net->ipv6.fib6_main_tbl->tb6_root.fn_flags = |
2431 | RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; |
2432 | inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); |
2433 | |
2434 | #ifdef CONFIG_IPV6_MULTIPLE_TABLES |
2435 | net->ipv6.fib6_local_tbl = kzalloc(size: sizeof(*net->ipv6.fib6_local_tbl), |
2436 | GFP_KERNEL); |
2437 | if (!net->ipv6.fib6_local_tbl) |
2438 | goto out_fib6_main_tbl; |
2439 | net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; |
2440 | rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, |
2441 | net->ipv6.fib6_null_entry); |
2442 | net->ipv6.fib6_local_tbl->tb6_root.fn_flags = |
2443 | RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; |
2444 | inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); |
2445 | #endif |
2446 | fib6_tables_init(net); |
2447 | |
2448 | return 0; |
2449 | |
2450 | #ifdef CONFIG_IPV6_MULTIPLE_TABLES |
2451 | out_fib6_main_tbl: |
2452 | kfree(objp: net->ipv6.fib6_main_tbl); |
2453 | #endif |
2454 | out_fib_table_hash: |
2455 | kfree(objp: net->ipv6.fib_table_hash); |
2456 | out_rt6_stats: |
2457 | kfree(objp: net->ipv6.rt6_stats); |
2458 | out_notifier: |
2459 | fib6_notifier_exit(net); |
2460 | return -ENOMEM; |
2461 | } |
2462 | |
2463 | static void fib6_net_exit(struct net *net) |
2464 | { |
2465 | unsigned int i; |
2466 | |
2467 | del_timer_sync(timer: &net->ipv6.ip6_fib_timer); |
2468 | |
2469 | for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { |
2470 | struct hlist_head *head = &net->ipv6.fib_table_hash[i]; |
2471 | struct hlist_node *tmp; |
2472 | struct fib6_table *tb; |
2473 | |
2474 | hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { |
2475 | hlist_del(n: &tb->tb6_hlist); |
2476 | fib6_free_table(table: tb); |
2477 | } |
2478 | } |
2479 | |
2480 | kfree(objp: net->ipv6.fib_table_hash); |
2481 | kfree(objp: net->ipv6.rt6_stats); |
2482 | fib6_notifier_exit(net); |
2483 | } |
2484 | |
2485 | static struct pernet_operations fib6_net_ops = { |
2486 | .init = fib6_net_init, |
2487 | .exit = fib6_net_exit, |
2488 | }; |
2489 | |
2490 | int __init fib6_init(void) |
2491 | { |
2492 | int ret = -ENOMEM; |
2493 | |
2494 | fib6_node_kmem = kmem_cache_create(name: "fib6_nodes" , |
2495 | size: sizeof(struct fib6_node), align: 0, |
2496 | SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, |
2497 | NULL); |
2498 | if (!fib6_node_kmem) |
2499 | goto out; |
2500 | |
2501 | ret = register_pernet_subsys(&fib6_net_ops); |
2502 | if (ret) |
2503 | goto out_kmem_cache_create; |
2504 | |
2505 | ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL, |
2506 | inet6_dump_fib, flags: 0); |
2507 | if (ret) |
2508 | goto out_unregister_subsys; |
2509 | |
2510 | __fib6_flush_trees = fib6_flush_trees; |
2511 | out: |
2512 | return ret; |
2513 | |
2514 | out_unregister_subsys: |
2515 | unregister_pernet_subsys(&fib6_net_ops); |
2516 | out_kmem_cache_create: |
2517 | kmem_cache_destroy(s: fib6_node_kmem); |
2518 | goto out; |
2519 | } |
2520 | |
2521 | void fib6_gc_cleanup(void) |
2522 | { |
2523 | unregister_pernet_subsys(&fib6_net_ops); |
2524 | kmem_cache_destroy(s: fib6_node_kmem); |
2525 | } |
2526 | |
2527 | #ifdef CONFIG_PROC_FS |
2528 | static int ipv6_route_native_seq_show(struct seq_file *seq, void *v) |
2529 | { |
2530 | struct fib6_info *rt = v; |
2531 | struct ipv6_route_iter *iter = seq->private; |
2532 | struct fib6_nh *fib6_nh = rt->fib6_nh; |
2533 | unsigned int flags = rt->fib6_flags; |
2534 | const struct net_device *dev; |
2535 | |
2536 | if (rt->nh) |
2537 | fib6_nh = nexthop_fib6_nh(nh: rt->nh); |
2538 | |
2539 | seq_printf(m: seq, fmt: "%pi6 %02x " , &rt->fib6_dst.addr, rt->fib6_dst.plen); |
2540 | |
2541 | #ifdef CONFIG_IPV6_SUBTREES |
2542 | seq_printf(m: seq, fmt: "%pi6 %02x " , &rt->fib6_src.addr, rt->fib6_src.plen); |
2543 | #else |
2544 | seq_puts(seq, "00000000000000000000000000000000 00 " ); |
2545 | #endif |
2546 | if (fib6_nh->fib_nh_gw_family) { |
2547 | flags |= RTF_GATEWAY; |
2548 | seq_printf(m: seq, fmt: "%pi6" , &fib6_nh->fib_nh_gw6); |
2549 | } else { |
2550 | seq_puts(m: seq, s: "00000000000000000000000000000000" ); |
2551 | } |
2552 | |
2553 | dev = fib6_nh->fib_nh_dev; |
2554 | seq_printf(m: seq, fmt: " %08x %08x %08x %08x %8s\n" , |
2555 | rt->fib6_metric, refcount_read(r: &rt->fib6_ref), 0, |
2556 | flags, dev ? dev->name : "" ); |
2557 | iter->w.leaf = NULL; |
2558 | return 0; |
2559 | } |
2560 | |
2561 | static int ipv6_route_yield(struct fib6_walker *w) |
2562 | { |
2563 | struct ipv6_route_iter *iter = w->args; |
2564 | |
2565 | if (!iter->skip) |
2566 | return 1; |
2567 | |
2568 | do { |
2569 | iter->w.leaf = rcu_dereference_protected( |
2570 | iter->w.leaf->fib6_next, |
2571 | lockdep_is_held(&iter->tbl->tb6_lock)); |
2572 | iter->skip--; |
2573 | if (!iter->skip && iter->w.leaf) |
2574 | return 1; |
2575 | } while (iter->w.leaf); |
2576 | |
2577 | return 0; |
2578 | } |
2579 | |
2580 | static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, |
2581 | struct net *net) |
2582 | { |
2583 | memset(&iter->w, 0, sizeof(iter->w)); |
2584 | iter->w.func = ipv6_route_yield; |
2585 | iter->w.root = &iter->tbl->tb6_root; |
2586 | iter->w.state = FWS_INIT; |
2587 | iter->w.node = iter->w.root; |
2588 | iter->w.args = iter; |
2589 | iter->sernum = READ_ONCE(iter->w.root->fn_sernum); |
2590 | INIT_LIST_HEAD(list: &iter->w.lh); |
2591 | fib6_walker_link(net, w: &iter->w); |
2592 | } |
2593 | |
2594 | static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, |
2595 | struct net *net) |
2596 | { |
2597 | unsigned int h; |
2598 | struct hlist_node *node; |
2599 | |
2600 | if (tbl) { |
2601 | h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; |
2602 | node = rcu_dereference(hlist_next_rcu(&tbl->tb6_hlist)); |
2603 | } else { |
2604 | h = 0; |
2605 | node = NULL; |
2606 | } |
2607 | |
2608 | while (!node && h < FIB6_TABLE_HASHSZ) { |
2609 | node = rcu_dereference( |
2610 | hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); |
2611 | } |
2612 | return hlist_entry_safe(node, struct fib6_table, tb6_hlist); |
2613 | } |
2614 | |
2615 | static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) |
2616 | { |
2617 | int sernum = READ_ONCE(iter->w.root->fn_sernum); |
2618 | |
2619 | if (iter->sernum != sernum) { |
2620 | iter->sernum = sernum; |
2621 | iter->w.state = FWS_INIT; |
2622 | iter->w.node = iter->w.root; |
2623 | WARN_ON(iter->w.skip); |
2624 | iter->w.skip = iter->w.count; |
2625 | } |
2626 | } |
2627 | |
2628 | static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
2629 | { |
2630 | int r; |
2631 | struct fib6_info *n; |
2632 | struct net *net = seq_file_net(seq); |
2633 | struct ipv6_route_iter *iter = seq->private; |
2634 | |
2635 | ++(*pos); |
2636 | if (!v) |
2637 | goto iter_table; |
2638 | |
2639 | n = rcu_dereference(((struct fib6_info *)v)->fib6_next); |
2640 | if (n) |
2641 | return n; |
2642 | |
2643 | iter_table: |
2644 | ipv6_route_check_sernum(iter); |
2645 | spin_lock_bh(lock: &iter->tbl->tb6_lock); |
2646 | r = fib6_walk_continue(w: &iter->w); |
2647 | spin_unlock_bh(lock: &iter->tbl->tb6_lock); |
2648 | if (r > 0) { |
2649 | return iter->w.leaf; |
2650 | } else if (r < 0) { |
2651 | fib6_walker_unlink(net, w: &iter->w); |
2652 | return NULL; |
2653 | } |
2654 | fib6_walker_unlink(net, w: &iter->w); |
2655 | |
2656 | iter->tbl = ipv6_route_seq_next_table(tbl: iter->tbl, net); |
2657 | if (!iter->tbl) |
2658 | return NULL; |
2659 | |
2660 | ipv6_route_seq_setup_walk(iter, net); |
2661 | goto iter_table; |
2662 | } |
2663 | |
2664 | static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) |
2665 | __acquires(RCU) |
2666 | { |
2667 | struct net *net = seq_file_net(seq); |
2668 | struct ipv6_route_iter *iter = seq->private; |
2669 | |
2670 | rcu_read_lock(); |
2671 | iter->tbl = ipv6_route_seq_next_table(NULL, net); |
2672 | iter->skip = *pos; |
2673 | |
2674 | if (iter->tbl) { |
2675 | loff_t p = 0; |
2676 | |
2677 | ipv6_route_seq_setup_walk(iter, net); |
2678 | return ipv6_route_seq_next(seq, NULL, pos: &p); |
2679 | } else { |
2680 | return NULL; |
2681 | } |
2682 | } |
2683 | |
2684 | static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) |
2685 | { |
2686 | struct fib6_walker *w = &iter->w; |
2687 | return w->node && !(w->state == FWS_U && w->node == w->root); |
2688 | } |
2689 | |
2690 | static void ipv6_route_native_seq_stop(struct seq_file *seq, void *v) |
2691 | __releases(RCU) |
2692 | { |
2693 | struct net *net = seq_file_net(seq); |
2694 | struct ipv6_route_iter *iter = seq->private; |
2695 | |
2696 | if (ipv6_route_iter_active(iter)) |
2697 | fib6_walker_unlink(net, w: &iter->w); |
2698 | |
2699 | rcu_read_unlock(); |
2700 | } |
2701 | |
2702 | #if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL) |
2703 | static int ipv6_route_prog_seq_show(struct bpf_prog *prog, |
2704 | struct bpf_iter_meta *meta, |
2705 | void *v) |
2706 | { |
2707 | struct bpf_iter__ipv6_route ctx; |
2708 | |
2709 | ctx.meta = meta; |
2710 | ctx.rt = v; |
2711 | return bpf_iter_run_prog(prog, ctx: &ctx); |
2712 | } |
2713 | |
2714 | static int ipv6_route_seq_show(struct seq_file *seq, void *v) |
2715 | { |
2716 | struct ipv6_route_iter *iter = seq->private; |
2717 | struct bpf_iter_meta meta; |
2718 | struct bpf_prog *prog; |
2719 | int ret; |
2720 | |
2721 | meta.seq = seq; |
2722 | prog = bpf_iter_get_info(meta: &meta, in_stop: false); |
2723 | if (!prog) |
2724 | return ipv6_route_native_seq_show(seq, v); |
2725 | |
2726 | ret = ipv6_route_prog_seq_show(prog, meta: &meta, v); |
2727 | iter->w.leaf = NULL; |
2728 | |
2729 | return ret; |
2730 | } |
2731 | |
2732 | static void ipv6_route_seq_stop(struct seq_file *seq, void *v) |
2733 | { |
2734 | struct bpf_iter_meta meta; |
2735 | struct bpf_prog *prog; |
2736 | |
2737 | if (!v) { |
2738 | meta.seq = seq; |
2739 | prog = bpf_iter_get_info(meta: &meta, in_stop: true); |
2740 | if (prog) |
2741 | (void)ipv6_route_prog_seq_show(prog, meta: &meta, v); |
2742 | } |
2743 | |
2744 | ipv6_route_native_seq_stop(seq, v); |
2745 | } |
2746 | #else |
2747 | static int ipv6_route_seq_show(struct seq_file *seq, void *v) |
2748 | { |
2749 | return ipv6_route_native_seq_show(seq, v); |
2750 | } |
2751 | |
2752 | static void ipv6_route_seq_stop(struct seq_file *seq, void *v) |
2753 | { |
2754 | ipv6_route_native_seq_stop(seq, v); |
2755 | } |
2756 | #endif |
2757 | |
2758 | const struct seq_operations ipv6_route_seq_ops = { |
2759 | .start = ipv6_route_seq_start, |
2760 | .next = ipv6_route_seq_next, |
2761 | .stop = ipv6_route_seq_stop, |
2762 | .show = ipv6_route_seq_show |
2763 | }; |
2764 | #endif /* CONFIG_PROC_FS */ |
2765 | |