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[mirror_ubuntu-jammy-kernel.git] / net / ipv4 / nexthop.c
1 // SPDX-License-Identifier: GPL-2.0
2 /* Generic nexthop implementation
3 *
4 * Copyright (c) 2017-19 Cumulus Networks
5 * Copyright (c) 2017-19 David Ahern <dsa@cumulusnetworks.com>
6 */
7
8 #include <linux/nexthop.h>
9 #include <linux/rtnetlink.h>
10 #include <linux/slab.h>
11 #include <net/arp.h>
12 #include <net/ipv6_stubs.h>
13 #include <net/lwtunnel.h>
14 #include <net/ndisc.h>
15 #include <net/nexthop.h>
16 #include <net/route.h>
17 #include <net/sock.h>
18
19 #define NH_RES_DEFAULT_IDLE_TIMER (120 * HZ)
20 #define NH_RES_DEFAULT_UNBALANCED_TIMER 0 /* No forced rebalancing. */
21
22 static void remove_nexthop(struct net *net, struct nexthop *nh,
23 struct nl_info *nlinfo);
24
25 #define NH_DEV_HASHBITS 8
26 #define NH_DEV_HASHSIZE (1U << NH_DEV_HASHBITS)
27
28 static const struct nla_policy rtm_nh_policy_new[] = {
29 [NHA_ID] = { .type = NLA_U32 },
30 [NHA_GROUP] = { .type = NLA_BINARY },
31 [NHA_GROUP_TYPE] = { .type = NLA_U16 },
32 [NHA_BLACKHOLE] = { .type = NLA_FLAG },
33 [NHA_OIF] = { .type = NLA_U32 },
34 [NHA_GATEWAY] = { .type = NLA_BINARY },
35 [NHA_ENCAP_TYPE] = { .type = NLA_U16 },
36 [NHA_ENCAP] = { .type = NLA_NESTED },
37 [NHA_FDB] = { .type = NLA_FLAG },
38 [NHA_RES_GROUP] = { .type = NLA_NESTED },
39 };
40
41 static const struct nla_policy rtm_nh_policy_get[] = {
42 [NHA_ID] = { .type = NLA_U32 },
43 };
44
45 static const struct nla_policy rtm_nh_policy_dump[] = {
46 [NHA_OIF] = { .type = NLA_U32 },
47 [NHA_GROUPS] = { .type = NLA_FLAG },
48 [NHA_MASTER] = { .type = NLA_U32 },
49 [NHA_FDB] = { .type = NLA_FLAG },
50 };
51
52 static const struct nla_policy rtm_nh_res_policy_new[] = {
53 [NHA_RES_GROUP_BUCKETS] = { .type = NLA_U16 },
54 [NHA_RES_GROUP_IDLE_TIMER] = { .type = NLA_U32 },
55 [NHA_RES_GROUP_UNBALANCED_TIMER] = { .type = NLA_U32 },
56 };
57
58 static const struct nla_policy rtm_nh_policy_dump_bucket[] = {
59 [NHA_ID] = { .type = NLA_U32 },
60 [NHA_OIF] = { .type = NLA_U32 },
61 [NHA_MASTER] = { .type = NLA_U32 },
62 [NHA_RES_BUCKET] = { .type = NLA_NESTED },
63 };
64
65 static const struct nla_policy rtm_nh_res_bucket_policy_dump[] = {
66 [NHA_RES_BUCKET_NH_ID] = { .type = NLA_U32 },
67 };
68
69 static const struct nla_policy rtm_nh_policy_get_bucket[] = {
70 [NHA_ID] = { .type = NLA_U32 },
71 [NHA_RES_BUCKET] = { .type = NLA_NESTED },
72 };
73
74 static const struct nla_policy rtm_nh_res_bucket_policy_get[] = {
75 [NHA_RES_BUCKET_INDEX] = { .type = NLA_U16 },
76 };
77
78 static bool nexthop_notifiers_is_empty(struct net *net)
79 {
80 return !net->nexthop.notifier_chain.head;
81 }
82
83 static void
84 __nh_notifier_single_info_init(struct nh_notifier_single_info *nh_info,
85 const struct nh_info *nhi)
86 {
87 nh_info->dev = nhi->fib_nhc.nhc_dev;
88 nh_info->gw_family = nhi->fib_nhc.nhc_gw_family;
89 if (nh_info->gw_family == AF_INET)
90 nh_info->ipv4 = nhi->fib_nhc.nhc_gw.ipv4;
91 else if (nh_info->gw_family == AF_INET6)
92 nh_info->ipv6 = nhi->fib_nhc.nhc_gw.ipv6;
93
94 nh_info->is_reject = nhi->reject_nh;
95 nh_info->is_fdb = nhi->fdb_nh;
96 nh_info->has_encap = !!nhi->fib_nhc.nhc_lwtstate;
97 }
98
99 static int nh_notifier_single_info_init(struct nh_notifier_info *info,
100 const struct nexthop *nh)
101 {
102 struct nh_info *nhi = rtnl_dereference(nh->nh_info);
103
104 info->type = NH_NOTIFIER_INFO_TYPE_SINGLE;
105 info->nh = kzalloc(sizeof(*info->nh), GFP_KERNEL);
106 if (!info->nh)
107 return -ENOMEM;
108
109 __nh_notifier_single_info_init(info->nh, nhi);
110
111 return 0;
112 }
113
114 static void nh_notifier_single_info_fini(struct nh_notifier_info *info)
115 {
116 kfree(info->nh);
117 }
118
119 static int nh_notifier_mpath_info_init(struct nh_notifier_info *info,
120 struct nh_group *nhg)
121 {
122 u16 num_nh = nhg->num_nh;
123 int i;
124
125 info->type = NH_NOTIFIER_INFO_TYPE_GRP;
126 info->nh_grp = kzalloc(struct_size(info->nh_grp, nh_entries, num_nh),
127 GFP_KERNEL);
128 if (!info->nh_grp)
129 return -ENOMEM;
130
131 info->nh_grp->num_nh = num_nh;
132 info->nh_grp->is_fdb = nhg->fdb_nh;
133
134 for (i = 0; i < num_nh; i++) {
135 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
136 struct nh_info *nhi;
137
138 nhi = rtnl_dereference(nhge->nh->nh_info);
139 info->nh_grp->nh_entries[i].id = nhge->nh->id;
140 info->nh_grp->nh_entries[i].weight = nhge->weight;
141 __nh_notifier_single_info_init(&info->nh_grp->nh_entries[i].nh,
142 nhi);
143 }
144
145 return 0;
146 }
147
148 static int nh_notifier_res_table_info_init(struct nh_notifier_info *info,
149 struct nh_group *nhg)
150 {
151 struct nh_res_table *res_table = rtnl_dereference(nhg->res_table);
152 u16 num_nh_buckets = res_table->num_nh_buckets;
153 unsigned long size;
154 u16 i;
155
156 info->type = NH_NOTIFIER_INFO_TYPE_RES_TABLE;
157 size = struct_size(info->nh_res_table, nhs, num_nh_buckets);
158 info->nh_res_table = __vmalloc(size, GFP_KERNEL | __GFP_ZERO |
159 __GFP_NOWARN);
160 if (!info->nh_res_table)
161 return -ENOMEM;
162
163 info->nh_res_table->num_nh_buckets = num_nh_buckets;
164
165 for (i = 0; i < num_nh_buckets; i++) {
166 struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
167 struct nh_grp_entry *nhge;
168 struct nh_info *nhi;
169
170 nhge = rtnl_dereference(bucket->nh_entry);
171 nhi = rtnl_dereference(nhge->nh->nh_info);
172 __nh_notifier_single_info_init(&info->nh_res_table->nhs[i],
173 nhi);
174 }
175
176 return 0;
177 }
178
179 static int nh_notifier_grp_info_init(struct nh_notifier_info *info,
180 const struct nexthop *nh)
181 {
182 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
183
184 if (nhg->hash_threshold)
185 return nh_notifier_mpath_info_init(info, nhg);
186 else if (nhg->resilient)
187 return nh_notifier_res_table_info_init(info, nhg);
188 return -EINVAL;
189 }
190
191 static void nh_notifier_grp_info_fini(struct nh_notifier_info *info,
192 const struct nexthop *nh)
193 {
194 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
195
196 if (nhg->hash_threshold)
197 kfree(info->nh_grp);
198 else if (nhg->resilient)
199 vfree(info->nh_res_table);
200 }
201
202 static int nh_notifier_info_init(struct nh_notifier_info *info,
203 const struct nexthop *nh)
204 {
205 info->id = nh->id;
206
207 if (nh->is_group)
208 return nh_notifier_grp_info_init(info, nh);
209 else
210 return nh_notifier_single_info_init(info, nh);
211 }
212
213 static void nh_notifier_info_fini(struct nh_notifier_info *info,
214 const struct nexthop *nh)
215 {
216 if (nh->is_group)
217 nh_notifier_grp_info_fini(info, nh);
218 else
219 nh_notifier_single_info_fini(info);
220 }
221
222 static int call_nexthop_notifiers(struct net *net,
223 enum nexthop_event_type event_type,
224 struct nexthop *nh,
225 struct netlink_ext_ack *extack)
226 {
227 struct nh_notifier_info info = {
228 .net = net,
229 .extack = extack,
230 };
231 int err;
232
233 ASSERT_RTNL();
234
235 if (nexthop_notifiers_is_empty(net))
236 return 0;
237
238 err = nh_notifier_info_init(&info, nh);
239 if (err) {
240 NL_SET_ERR_MSG(extack, "Failed to initialize nexthop notifier info");
241 return err;
242 }
243
244 err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
245 event_type, &info);
246 nh_notifier_info_fini(&info, nh);
247
248 return notifier_to_errno(err);
249 }
250
251 static int
252 nh_notifier_res_bucket_idle_timer_get(const struct nh_notifier_info *info,
253 bool force, unsigned int *p_idle_timer_ms)
254 {
255 struct nh_res_table *res_table;
256 struct nh_group *nhg;
257 struct nexthop *nh;
258 int err = 0;
259
260 /* When 'force' is false, nexthop bucket replacement is performed
261 * because the bucket was deemed to be idle. In this case, capable
262 * listeners can choose to perform an atomic replacement: The bucket is
263 * only replaced if it is inactive. However, if the idle timer interval
264 * is smaller than the interval in which a listener is querying
265 * buckets' activity from the device, then atomic replacement should
266 * not be tried. Pass the idle timer value to listeners, so that they
267 * could determine which type of replacement to perform.
268 */
269 if (force) {
270 *p_idle_timer_ms = 0;
271 return 0;
272 }
273
274 rcu_read_lock();
275
276 nh = nexthop_find_by_id(info->net, info->id);
277 if (!nh) {
278 err = -EINVAL;
279 goto out;
280 }
281
282 nhg = rcu_dereference(nh->nh_grp);
283 res_table = rcu_dereference(nhg->res_table);
284 *p_idle_timer_ms = jiffies_to_msecs(res_table->idle_timer);
285
286 out:
287 rcu_read_unlock();
288
289 return err;
290 }
291
292 static int nh_notifier_res_bucket_info_init(struct nh_notifier_info *info,
293 u16 bucket_index, bool force,
294 struct nh_info *oldi,
295 struct nh_info *newi)
296 {
297 unsigned int idle_timer_ms;
298 int err;
299
300 err = nh_notifier_res_bucket_idle_timer_get(info, force,
301 &idle_timer_ms);
302 if (err)
303 return err;
304
305 info->type = NH_NOTIFIER_INFO_TYPE_RES_BUCKET;
306 info->nh_res_bucket = kzalloc(sizeof(*info->nh_res_bucket),
307 GFP_KERNEL);
308 if (!info->nh_res_bucket)
309 return -ENOMEM;
310
311 info->nh_res_bucket->bucket_index = bucket_index;
312 info->nh_res_bucket->idle_timer_ms = idle_timer_ms;
313 info->nh_res_bucket->force = force;
314 __nh_notifier_single_info_init(&info->nh_res_bucket->old_nh, oldi);
315 __nh_notifier_single_info_init(&info->nh_res_bucket->new_nh, newi);
316 return 0;
317 }
318
319 static void nh_notifier_res_bucket_info_fini(struct nh_notifier_info *info)
320 {
321 kfree(info->nh_res_bucket);
322 }
323
324 static int __call_nexthop_res_bucket_notifiers(struct net *net, u32 nhg_id,
325 u16 bucket_index, bool force,
326 struct nh_info *oldi,
327 struct nh_info *newi,
328 struct netlink_ext_ack *extack)
329 {
330 struct nh_notifier_info info = {
331 .net = net,
332 .extack = extack,
333 .id = nhg_id,
334 };
335 int err;
336
337 if (nexthop_notifiers_is_empty(net))
338 return 0;
339
340 err = nh_notifier_res_bucket_info_init(&info, bucket_index, force,
341 oldi, newi);
342 if (err)
343 return err;
344
345 err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
346 NEXTHOP_EVENT_BUCKET_REPLACE, &info);
347 nh_notifier_res_bucket_info_fini(&info);
348
349 return notifier_to_errno(err);
350 }
351
352 /* There are three users of RES_TABLE, and NHs etc. referenced from there:
353 *
354 * 1) a collection of callbacks for NH maintenance. This operates under
355 * RTNL,
356 * 2) the delayed work that gradually balances the resilient table,
357 * 3) and nexthop_select_path(), operating under RCU.
358 *
359 * Both the delayed work and the RTNL block are writers, and need to
360 * maintain mutual exclusion. Since there are only two and well-known
361 * writers for each table, the RTNL code can make sure it has exclusive
362 * access thus:
363 *
364 * - Have the DW operate without locking;
365 * - synchronously cancel the DW;
366 * - do the writing;
367 * - if the write was not actually a delete, call upkeep, which schedules
368 * DW again if necessary.
369 *
370 * The functions that are always called from the RTNL context use
371 * rtnl_dereference(). The functions that can also be called from the DW do
372 * a raw dereference and rely on the above mutual exclusion scheme.
373 */
374 #define nh_res_dereference(p) (rcu_dereference_raw(p))
375
376 static int call_nexthop_res_bucket_notifiers(struct net *net, u32 nhg_id,
377 u16 bucket_index, bool force,
378 struct nexthop *old_nh,
379 struct nexthop *new_nh,
380 struct netlink_ext_ack *extack)
381 {
382 struct nh_info *oldi = nh_res_dereference(old_nh->nh_info);
383 struct nh_info *newi = nh_res_dereference(new_nh->nh_info);
384
385 return __call_nexthop_res_bucket_notifiers(net, nhg_id, bucket_index,
386 force, oldi, newi, extack);
387 }
388
389 static int call_nexthop_res_table_notifiers(struct net *net, struct nexthop *nh,
390 struct netlink_ext_ack *extack)
391 {
392 struct nh_notifier_info info = {
393 .net = net,
394 .extack = extack,
395 };
396 struct nh_group *nhg;
397 int err;
398
399 ASSERT_RTNL();
400
401 if (nexthop_notifiers_is_empty(net))
402 return 0;
403
404 /* At this point, the nexthop buckets are still not populated. Only
405 * emit a notification with the logical nexthops, so that a listener
406 * could potentially veto it in case of unsupported configuration.
407 */
408 nhg = rtnl_dereference(nh->nh_grp);
409 err = nh_notifier_mpath_info_init(&info, nhg);
410 if (err) {
411 NL_SET_ERR_MSG(extack, "Failed to initialize nexthop notifier info");
412 return err;
413 }
414
415 err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
416 NEXTHOP_EVENT_RES_TABLE_PRE_REPLACE,
417 &info);
418 kfree(info.nh_grp);
419
420 return notifier_to_errno(err);
421 }
422
423 static int call_nexthop_notifier(struct notifier_block *nb, struct net *net,
424 enum nexthop_event_type event_type,
425 struct nexthop *nh,
426 struct netlink_ext_ack *extack)
427 {
428 struct nh_notifier_info info = {
429 .net = net,
430 .extack = extack,
431 };
432 int err;
433
434 err = nh_notifier_info_init(&info, nh);
435 if (err)
436 return err;
437
438 err = nb->notifier_call(nb, event_type, &info);
439 nh_notifier_info_fini(&info, nh);
440
441 return notifier_to_errno(err);
442 }
443
444 static unsigned int nh_dev_hashfn(unsigned int val)
445 {
446 unsigned int mask = NH_DEV_HASHSIZE - 1;
447
448 return (val ^
449 (val >> NH_DEV_HASHBITS) ^
450 (val >> (NH_DEV_HASHBITS * 2))) & mask;
451 }
452
453 static void nexthop_devhash_add(struct net *net, struct nh_info *nhi)
454 {
455 struct net_device *dev = nhi->fib_nhc.nhc_dev;
456 struct hlist_head *head;
457 unsigned int hash;
458
459 WARN_ON(!dev);
460
461 hash = nh_dev_hashfn(dev->ifindex);
462 head = &net->nexthop.devhash[hash];
463 hlist_add_head(&nhi->dev_hash, head);
464 }
465
466 static void nexthop_free_group(struct nexthop *nh)
467 {
468 struct nh_group *nhg;
469 int i;
470
471 nhg = rcu_dereference_raw(nh->nh_grp);
472 for (i = 0; i < nhg->num_nh; ++i) {
473 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
474
475 WARN_ON(!list_empty(&nhge->nh_list));
476 nexthop_put(nhge->nh);
477 }
478
479 WARN_ON(nhg->spare == nhg);
480
481 if (nhg->resilient)
482 vfree(rcu_dereference_raw(nhg->res_table));
483
484 kfree(nhg->spare);
485 kfree(nhg);
486 }
487
488 static void nexthop_free_single(struct nexthop *nh)
489 {
490 struct nh_info *nhi;
491
492 nhi = rcu_dereference_raw(nh->nh_info);
493 switch (nhi->family) {
494 case AF_INET:
495 fib_nh_release(nh->net, &nhi->fib_nh);
496 break;
497 case AF_INET6:
498 ipv6_stub->fib6_nh_release(&nhi->fib6_nh);
499 break;
500 }
501 kfree(nhi);
502 }
503
504 void nexthop_free_rcu(struct rcu_head *head)
505 {
506 struct nexthop *nh = container_of(head, struct nexthop, rcu);
507
508 if (nh->is_group)
509 nexthop_free_group(nh);
510 else
511 nexthop_free_single(nh);
512
513 kfree(nh);
514 }
515 EXPORT_SYMBOL_GPL(nexthop_free_rcu);
516
517 static struct nexthop *nexthop_alloc(void)
518 {
519 struct nexthop *nh;
520
521 nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL);
522 if (nh) {
523 INIT_LIST_HEAD(&nh->fi_list);
524 INIT_LIST_HEAD(&nh->f6i_list);
525 INIT_LIST_HEAD(&nh->grp_list);
526 INIT_LIST_HEAD(&nh->fdb_list);
527 }
528 return nh;
529 }
530
531 static struct nh_group *nexthop_grp_alloc(u16 num_nh)
532 {
533 struct nh_group *nhg;
534
535 nhg = kzalloc(struct_size(nhg, nh_entries, num_nh), GFP_KERNEL);
536 if (nhg)
537 nhg->num_nh = num_nh;
538
539 return nhg;
540 }
541
542 static void nh_res_table_upkeep_dw(struct work_struct *work);
543
544 static struct nh_res_table *
545 nexthop_res_table_alloc(struct net *net, u32 nhg_id, struct nh_config *cfg)
546 {
547 const u16 num_nh_buckets = cfg->nh_grp_res_num_buckets;
548 struct nh_res_table *res_table;
549 unsigned long size;
550
551 size = struct_size(res_table, nh_buckets, num_nh_buckets);
552 res_table = __vmalloc(size, GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
553 if (!res_table)
554 return NULL;
555
556 res_table->net = net;
557 res_table->nhg_id = nhg_id;
558 INIT_DELAYED_WORK(&res_table->upkeep_dw, &nh_res_table_upkeep_dw);
559 INIT_LIST_HEAD(&res_table->uw_nh_entries);
560 res_table->idle_timer = cfg->nh_grp_res_idle_timer;
561 res_table->unbalanced_timer = cfg->nh_grp_res_unbalanced_timer;
562 res_table->num_nh_buckets = num_nh_buckets;
563 return res_table;
564 }
565
566 static void nh_base_seq_inc(struct net *net)
567 {
568 while (++net->nexthop.seq == 0)
569 ;
570 }
571
572 /* no reference taken; rcu lock or rtnl must be held */
573 struct nexthop *nexthop_find_by_id(struct net *net, u32 id)
574 {
575 struct rb_node **pp, *parent = NULL, *next;
576
577 pp = &net->nexthop.rb_root.rb_node;
578 while (1) {
579 struct nexthop *nh;
580
581 next = rcu_dereference_raw(*pp);
582 if (!next)
583 break;
584 parent = next;
585
586 nh = rb_entry(parent, struct nexthop, rb_node);
587 if (id < nh->id)
588 pp = &next->rb_left;
589 else if (id > nh->id)
590 pp = &next->rb_right;
591 else
592 return nh;
593 }
594 return NULL;
595 }
596 EXPORT_SYMBOL_GPL(nexthop_find_by_id);
597
598 /* used for auto id allocation; called with rtnl held */
599 static u32 nh_find_unused_id(struct net *net)
600 {
601 u32 id_start = net->nexthop.last_id_allocated;
602
603 while (1) {
604 net->nexthop.last_id_allocated++;
605 if (net->nexthop.last_id_allocated == id_start)
606 break;
607
608 if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated))
609 return net->nexthop.last_id_allocated;
610 }
611 return 0;
612 }
613
614 static void nh_res_time_set_deadline(unsigned long next_time,
615 unsigned long *deadline)
616 {
617 if (time_before(next_time, *deadline))
618 *deadline = next_time;
619 }
620
621 static clock_t nh_res_table_unbalanced_time(struct nh_res_table *res_table)
622 {
623 if (list_empty(&res_table->uw_nh_entries))
624 return 0;
625 return jiffies_delta_to_clock_t(jiffies - res_table->unbalanced_since);
626 }
627
628 static int nla_put_nh_group_res(struct sk_buff *skb, struct nh_group *nhg)
629 {
630 struct nh_res_table *res_table = rtnl_dereference(nhg->res_table);
631 struct nlattr *nest;
632
633 nest = nla_nest_start(skb, NHA_RES_GROUP);
634 if (!nest)
635 return -EMSGSIZE;
636
637 if (nla_put_u16(skb, NHA_RES_GROUP_BUCKETS,
638 res_table->num_nh_buckets) ||
639 nla_put_u32(skb, NHA_RES_GROUP_IDLE_TIMER,
640 jiffies_to_clock_t(res_table->idle_timer)) ||
641 nla_put_u32(skb, NHA_RES_GROUP_UNBALANCED_TIMER,
642 jiffies_to_clock_t(res_table->unbalanced_timer)) ||
643 nla_put_u64_64bit(skb, NHA_RES_GROUP_UNBALANCED_TIME,
644 nh_res_table_unbalanced_time(res_table),
645 NHA_RES_GROUP_PAD))
646 goto nla_put_failure;
647
648 nla_nest_end(skb, nest);
649 return 0;
650
651 nla_put_failure:
652 nla_nest_cancel(skb, nest);
653 return -EMSGSIZE;
654 }
655
656 static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg)
657 {
658 struct nexthop_grp *p;
659 size_t len = nhg->num_nh * sizeof(*p);
660 struct nlattr *nla;
661 u16 group_type = 0;
662 int i;
663
664 if (nhg->hash_threshold)
665 group_type = NEXTHOP_GRP_TYPE_MPATH;
666 else if (nhg->resilient)
667 group_type = NEXTHOP_GRP_TYPE_RES;
668
669 if (nla_put_u16(skb, NHA_GROUP_TYPE, group_type))
670 goto nla_put_failure;
671
672 nla = nla_reserve(skb, NHA_GROUP, len);
673 if (!nla)
674 goto nla_put_failure;
675
676 p = nla_data(nla);
677 for (i = 0; i < nhg->num_nh; ++i) {
678 p->id = nhg->nh_entries[i].nh->id;
679 p->weight = nhg->nh_entries[i].weight - 1;
680 p += 1;
681 }
682
683 if (nhg->resilient && nla_put_nh_group_res(skb, nhg))
684 goto nla_put_failure;
685
686 return 0;
687
688 nla_put_failure:
689 return -EMSGSIZE;
690 }
691
692 static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh,
693 int event, u32 portid, u32 seq, unsigned int nlflags)
694 {
695 struct fib6_nh *fib6_nh;
696 struct fib_nh *fib_nh;
697 struct nlmsghdr *nlh;
698 struct nh_info *nhi;
699 struct nhmsg *nhm;
700
701 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
702 if (!nlh)
703 return -EMSGSIZE;
704
705 nhm = nlmsg_data(nlh);
706 nhm->nh_family = AF_UNSPEC;
707 nhm->nh_flags = nh->nh_flags;
708 nhm->nh_protocol = nh->protocol;
709 nhm->nh_scope = 0;
710 nhm->resvd = 0;
711
712 if (nla_put_u32(skb, NHA_ID, nh->id))
713 goto nla_put_failure;
714
715 if (nh->is_group) {
716 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
717
718 if (nhg->fdb_nh && nla_put_flag(skb, NHA_FDB))
719 goto nla_put_failure;
720 if (nla_put_nh_group(skb, nhg))
721 goto nla_put_failure;
722 goto out;
723 }
724
725 nhi = rtnl_dereference(nh->nh_info);
726 nhm->nh_family = nhi->family;
727 if (nhi->reject_nh) {
728 if (nla_put_flag(skb, NHA_BLACKHOLE))
729 goto nla_put_failure;
730 goto out;
731 } else if (nhi->fdb_nh) {
732 if (nla_put_flag(skb, NHA_FDB))
733 goto nla_put_failure;
734 } else {
735 const struct net_device *dev;
736
737 dev = nhi->fib_nhc.nhc_dev;
738 if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex))
739 goto nla_put_failure;
740 }
741
742 nhm->nh_scope = nhi->fib_nhc.nhc_scope;
743 switch (nhi->family) {
744 case AF_INET:
745 fib_nh = &nhi->fib_nh;
746 if (fib_nh->fib_nh_gw_family &&
747 nla_put_be32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4))
748 goto nla_put_failure;
749 break;
750
751 case AF_INET6:
752 fib6_nh = &nhi->fib6_nh;
753 if (fib6_nh->fib_nh_gw_family &&
754 nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->fib_nh_gw6))
755 goto nla_put_failure;
756 break;
757 }
758
759 if (nhi->fib_nhc.nhc_lwtstate &&
760 lwtunnel_fill_encap(skb, nhi->fib_nhc.nhc_lwtstate,
761 NHA_ENCAP, NHA_ENCAP_TYPE) < 0)
762 goto nla_put_failure;
763
764 out:
765 nlmsg_end(skb, nlh);
766 return 0;
767
768 nla_put_failure:
769 nlmsg_cancel(skb, nlh);
770 return -EMSGSIZE;
771 }
772
773 static size_t nh_nlmsg_size_grp_res(struct nh_group *nhg)
774 {
775 return nla_total_size(0) + /* NHA_RES_GROUP */
776 nla_total_size(2) + /* NHA_RES_GROUP_BUCKETS */
777 nla_total_size(4) + /* NHA_RES_GROUP_IDLE_TIMER */
778 nla_total_size(4) + /* NHA_RES_GROUP_UNBALANCED_TIMER */
779 nla_total_size_64bit(8);/* NHA_RES_GROUP_UNBALANCED_TIME */
780 }
781
782 static size_t nh_nlmsg_size_grp(struct nexthop *nh)
783 {
784 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
785 size_t sz = sizeof(struct nexthop_grp) * nhg->num_nh;
786 size_t tot = nla_total_size(sz) +
787 nla_total_size(2); /* NHA_GROUP_TYPE */
788
789 if (nhg->resilient)
790 tot += nh_nlmsg_size_grp_res(nhg);
791
792 return tot;
793 }
794
795 static size_t nh_nlmsg_size_single(struct nexthop *nh)
796 {
797 struct nh_info *nhi = rtnl_dereference(nh->nh_info);
798 size_t sz;
799
800 /* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE
801 * are mutually exclusive
802 */
803 sz = nla_total_size(4); /* NHA_OIF */
804
805 switch (nhi->family) {
806 case AF_INET:
807 if (nhi->fib_nh.fib_nh_gw_family)
808 sz += nla_total_size(4); /* NHA_GATEWAY */
809 break;
810
811 case AF_INET6:
812 /* NHA_GATEWAY */
813 if (nhi->fib6_nh.fib_nh_gw_family)
814 sz += nla_total_size(sizeof(const struct in6_addr));
815 break;
816 }
817
818 if (nhi->fib_nhc.nhc_lwtstate) {
819 sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate);
820 sz += nla_total_size(2); /* NHA_ENCAP_TYPE */
821 }
822
823 return sz;
824 }
825
826 static size_t nh_nlmsg_size(struct nexthop *nh)
827 {
828 size_t sz = NLMSG_ALIGN(sizeof(struct nhmsg));
829
830 sz += nla_total_size(4); /* NHA_ID */
831
832 if (nh->is_group)
833 sz += nh_nlmsg_size_grp(nh);
834 else
835 sz += nh_nlmsg_size_single(nh);
836
837 return sz;
838 }
839
840 static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info)
841 {
842 unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0;
843 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
844 struct sk_buff *skb;
845 int err = -ENOBUFS;
846
847 skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any());
848 if (!skb)
849 goto errout;
850
851 err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags);
852 if (err < 0) {
853 /* -EMSGSIZE implies BUG in nh_nlmsg_size() */
854 WARN_ON(err == -EMSGSIZE);
855 kfree_skb(skb);
856 goto errout;
857 }
858
859 rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_NEXTHOP,
860 info->nlh, gfp_any());
861 return;
862 errout:
863 if (err < 0)
864 rtnl_set_sk_err(info->nl_net, RTNLGRP_NEXTHOP, err);
865 }
866
867 static unsigned long nh_res_bucket_used_time(const struct nh_res_bucket *bucket)
868 {
869 return (unsigned long)atomic_long_read(&bucket->used_time);
870 }
871
872 static unsigned long
873 nh_res_bucket_idle_point(const struct nh_res_table *res_table,
874 const struct nh_res_bucket *bucket,
875 unsigned long now)
876 {
877 unsigned long time = nh_res_bucket_used_time(bucket);
878
879 /* Bucket was not used since it was migrated. The idle time is now. */
880 if (time == bucket->migrated_time)
881 return now;
882
883 return time + res_table->idle_timer;
884 }
885
886 static unsigned long
887 nh_res_table_unb_point(const struct nh_res_table *res_table)
888 {
889 return res_table->unbalanced_since + res_table->unbalanced_timer;
890 }
891
892 static void nh_res_bucket_set_idle(const struct nh_res_table *res_table,
893 struct nh_res_bucket *bucket)
894 {
895 unsigned long now = jiffies;
896
897 atomic_long_set(&bucket->used_time, (long)now);
898 bucket->migrated_time = now;
899 }
900
901 static void nh_res_bucket_set_busy(struct nh_res_bucket *bucket)
902 {
903 atomic_long_set(&bucket->used_time, (long)jiffies);
904 }
905
906 static clock_t nh_res_bucket_idle_time(const struct nh_res_bucket *bucket)
907 {
908 unsigned long used_time = nh_res_bucket_used_time(bucket);
909
910 return jiffies_delta_to_clock_t(jiffies - used_time);
911 }
912
913 static int nh_fill_res_bucket(struct sk_buff *skb, struct nexthop *nh,
914 struct nh_res_bucket *bucket, u16 bucket_index,
915 int event, u32 portid, u32 seq,
916 unsigned int nlflags,
917 struct netlink_ext_ack *extack)
918 {
919 struct nh_grp_entry *nhge = nh_res_dereference(bucket->nh_entry);
920 struct nlmsghdr *nlh;
921 struct nlattr *nest;
922 struct nhmsg *nhm;
923
924 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
925 if (!nlh)
926 return -EMSGSIZE;
927
928 nhm = nlmsg_data(nlh);
929 nhm->nh_family = AF_UNSPEC;
930 nhm->nh_flags = bucket->nh_flags;
931 nhm->nh_protocol = nh->protocol;
932 nhm->nh_scope = 0;
933 nhm->resvd = 0;
934
935 if (nla_put_u32(skb, NHA_ID, nh->id))
936 goto nla_put_failure;
937
938 nest = nla_nest_start(skb, NHA_RES_BUCKET);
939 if (!nest)
940 goto nla_put_failure;
941
942 if (nla_put_u16(skb, NHA_RES_BUCKET_INDEX, bucket_index) ||
943 nla_put_u32(skb, NHA_RES_BUCKET_NH_ID, nhge->nh->id) ||
944 nla_put_u64_64bit(skb, NHA_RES_BUCKET_IDLE_TIME,
945 nh_res_bucket_idle_time(bucket),
946 NHA_RES_BUCKET_PAD))
947 goto nla_put_failure_nest;
948
949 nla_nest_end(skb, nest);
950 nlmsg_end(skb, nlh);
951 return 0;
952
953 nla_put_failure_nest:
954 nla_nest_cancel(skb, nest);
955 nla_put_failure:
956 nlmsg_cancel(skb, nlh);
957 return -EMSGSIZE;
958 }
959
960 static void nexthop_bucket_notify(struct nh_res_table *res_table,
961 u16 bucket_index)
962 {
963 struct nh_res_bucket *bucket = &res_table->nh_buckets[bucket_index];
964 struct nh_grp_entry *nhge = nh_res_dereference(bucket->nh_entry);
965 struct nexthop *nh = nhge->nh_parent;
966 struct sk_buff *skb;
967 int err = -ENOBUFS;
968
969 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
970 if (!skb)
971 goto errout;
972
973 err = nh_fill_res_bucket(skb, nh, bucket, bucket_index,
974 RTM_NEWNEXTHOPBUCKET, 0, 0, NLM_F_REPLACE,
975 NULL);
976 if (err < 0) {
977 kfree_skb(skb);
978 goto errout;
979 }
980
981 rtnl_notify(skb, nh->net, 0, RTNLGRP_NEXTHOP, NULL, GFP_KERNEL);
982 return;
983 errout:
984 if (err < 0)
985 rtnl_set_sk_err(nh->net, RTNLGRP_NEXTHOP, err);
986 }
987
988 static bool valid_group_nh(struct nexthop *nh, unsigned int npaths,
989 bool *is_fdb, struct netlink_ext_ack *extack)
990 {
991 if (nh->is_group) {
992 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
993
994 /* Nesting groups within groups is not supported. */
995 if (nhg->hash_threshold) {
996 NL_SET_ERR_MSG(extack,
997 "Hash-threshold group can not be a nexthop within a group");
998 return false;
999 }
1000 if (nhg->resilient) {
1001 NL_SET_ERR_MSG(extack,
1002 "Resilient group can not be a nexthop within a group");
1003 return false;
1004 }
1005 *is_fdb = nhg->fdb_nh;
1006 } else {
1007 struct nh_info *nhi = rtnl_dereference(nh->nh_info);
1008
1009 if (nhi->reject_nh && npaths > 1) {
1010 NL_SET_ERR_MSG(extack,
1011 "Blackhole nexthop can not be used in a group with more than 1 path");
1012 return false;
1013 }
1014 *is_fdb = nhi->fdb_nh;
1015 }
1016
1017 return true;
1018 }
1019
1020 static int nh_check_attr_fdb_group(struct nexthop *nh, u8 *nh_family,
1021 struct netlink_ext_ack *extack)
1022 {
1023 struct nh_info *nhi;
1024
1025 nhi = rtnl_dereference(nh->nh_info);
1026
1027 if (!nhi->fdb_nh) {
1028 NL_SET_ERR_MSG(extack, "FDB nexthop group can only have fdb nexthops");
1029 return -EINVAL;
1030 }
1031
1032 if (*nh_family == AF_UNSPEC) {
1033 *nh_family = nhi->family;
1034 } else if (*nh_family != nhi->family) {
1035 NL_SET_ERR_MSG(extack, "FDB nexthop group cannot have mixed family nexthops");
1036 return -EINVAL;
1037 }
1038
1039 return 0;
1040 }
1041
1042 static int nh_check_attr_group(struct net *net,
1043 struct nlattr *tb[], size_t tb_size,
1044 u16 nh_grp_type, struct netlink_ext_ack *extack)
1045 {
1046 unsigned int len = nla_len(tb[NHA_GROUP]);
1047 u8 nh_family = AF_UNSPEC;
1048 struct nexthop_grp *nhg;
1049 unsigned int i, j;
1050 u8 nhg_fdb = 0;
1051
1052 if (!len || len & (sizeof(struct nexthop_grp) - 1)) {
1053 NL_SET_ERR_MSG(extack,
1054 "Invalid length for nexthop group attribute");
1055 return -EINVAL;
1056 }
1057
1058 /* convert len to number of nexthop ids */
1059 len /= sizeof(*nhg);
1060
1061 nhg = nla_data(tb[NHA_GROUP]);
1062 for (i = 0; i < len; ++i) {
1063 if (nhg[i].resvd1 || nhg[i].resvd2) {
1064 NL_SET_ERR_MSG(extack, "Reserved fields in nexthop_grp must be 0");
1065 return -EINVAL;
1066 }
1067 if (nhg[i].weight > 254) {
1068 NL_SET_ERR_MSG(extack, "Invalid value for weight");
1069 return -EINVAL;
1070 }
1071 for (j = i + 1; j < len; ++j) {
1072 if (nhg[i].id == nhg[j].id) {
1073 NL_SET_ERR_MSG(extack, "Nexthop id can not be used twice in a group");
1074 return -EINVAL;
1075 }
1076 }
1077 }
1078
1079 if (tb[NHA_FDB])
1080 nhg_fdb = 1;
1081 nhg = nla_data(tb[NHA_GROUP]);
1082 for (i = 0; i < len; ++i) {
1083 struct nexthop *nh;
1084 bool is_fdb_nh;
1085
1086 nh = nexthop_find_by_id(net, nhg[i].id);
1087 if (!nh) {
1088 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
1089 return -EINVAL;
1090 }
1091 if (!valid_group_nh(nh, len, &is_fdb_nh, extack))
1092 return -EINVAL;
1093
1094 if (nhg_fdb && nh_check_attr_fdb_group(nh, &nh_family, extack))
1095 return -EINVAL;
1096
1097 if (!nhg_fdb && is_fdb_nh) {
1098 NL_SET_ERR_MSG(extack, "Non FDB nexthop group cannot have fdb nexthops");
1099 return -EINVAL;
1100 }
1101 }
1102 for (i = NHA_GROUP_TYPE + 1; i < tb_size; ++i) {
1103 if (!tb[i])
1104 continue;
1105 switch (i) {
1106 case NHA_FDB:
1107 continue;
1108 case NHA_RES_GROUP:
1109 if (nh_grp_type == NEXTHOP_GRP_TYPE_RES)
1110 continue;
1111 break;
1112 }
1113 NL_SET_ERR_MSG(extack,
1114 "No other attributes can be set in nexthop groups");
1115 return -EINVAL;
1116 }
1117
1118 return 0;
1119 }
1120
1121 static bool ipv6_good_nh(const struct fib6_nh *nh)
1122 {
1123 int state = NUD_REACHABLE;
1124 struct neighbour *n;
1125
1126 rcu_read_lock_bh();
1127
1128 n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6);
1129 if (n)
1130 state = n->nud_state;
1131
1132 rcu_read_unlock_bh();
1133
1134 return !!(state & NUD_VALID);
1135 }
1136
1137 static bool ipv4_good_nh(const struct fib_nh *nh)
1138 {
1139 int state = NUD_REACHABLE;
1140 struct neighbour *n;
1141
1142 rcu_read_lock_bh();
1143
1144 n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev,
1145 (__force u32)nh->fib_nh_gw4);
1146 if (n)
1147 state = n->nud_state;
1148
1149 rcu_read_unlock_bh();
1150
1151 return !!(state & NUD_VALID);
1152 }
1153
1154 static struct nexthop *nexthop_select_path_hthr(struct nh_group *nhg, int hash)
1155 {
1156 struct nexthop *rc = NULL;
1157 int i;
1158
1159 for (i = 0; i < nhg->num_nh; ++i) {
1160 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
1161 struct nh_info *nhi;
1162
1163 if (hash > atomic_read(&nhge->hthr.upper_bound))
1164 continue;
1165
1166 nhi = rcu_dereference(nhge->nh->nh_info);
1167 if (nhi->fdb_nh)
1168 return nhge->nh;
1169
1170 /* nexthops always check if it is good and does
1171 * not rely on a sysctl for this behavior
1172 */
1173 switch (nhi->family) {
1174 case AF_INET:
1175 if (ipv4_good_nh(&nhi->fib_nh))
1176 return nhge->nh;
1177 break;
1178 case AF_INET6:
1179 if (ipv6_good_nh(&nhi->fib6_nh))
1180 return nhge->nh;
1181 break;
1182 }
1183
1184 if (!rc)
1185 rc = nhge->nh;
1186 }
1187
1188 return rc;
1189 }
1190
1191 static struct nexthop *nexthop_select_path_res(struct nh_group *nhg, int hash)
1192 {
1193 struct nh_res_table *res_table = rcu_dereference(nhg->res_table);
1194 u16 bucket_index = hash % res_table->num_nh_buckets;
1195 struct nh_res_bucket *bucket;
1196 struct nh_grp_entry *nhge;
1197
1198 /* nexthop_select_path() is expected to return a non-NULL value, so
1199 * skip protocol validation and just hand out whatever there is.
1200 */
1201 bucket = &res_table->nh_buckets[bucket_index];
1202 nh_res_bucket_set_busy(bucket);
1203 nhge = rcu_dereference(bucket->nh_entry);
1204 return nhge->nh;
1205 }
1206
1207 struct nexthop *nexthop_select_path(struct nexthop *nh, int hash)
1208 {
1209 struct nh_group *nhg;
1210
1211 if (!nh->is_group)
1212 return nh;
1213
1214 nhg = rcu_dereference(nh->nh_grp);
1215 if (nhg->hash_threshold)
1216 return nexthop_select_path_hthr(nhg, hash);
1217 else if (nhg->resilient)
1218 return nexthop_select_path_res(nhg, hash);
1219
1220 /* Unreachable. */
1221 return NULL;
1222 }
1223 EXPORT_SYMBOL_GPL(nexthop_select_path);
1224
1225 int nexthop_for_each_fib6_nh(struct nexthop *nh,
1226 int (*cb)(struct fib6_nh *nh, void *arg),
1227 void *arg)
1228 {
1229 struct nh_info *nhi;
1230 int err;
1231
1232 if (nh->is_group) {
1233 struct nh_group *nhg;
1234 int i;
1235
1236 nhg = rcu_dereference_rtnl(nh->nh_grp);
1237 for (i = 0; i < nhg->num_nh; i++) {
1238 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
1239
1240 nhi = rcu_dereference_rtnl(nhge->nh->nh_info);
1241 err = cb(&nhi->fib6_nh, arg);
1242 if (err)
1243 return err;
1244 }
1245 } else {
1246 nhi = rcu_dereference_rtnl(nh->nh_info);
1247 err = cb(&nhi->fib6_nh, arg);
1248 if (err)
1249 return err;
1250 }
1251
1252 return 0;
1253 }
1254 EXPORT_SYMBOL_GPL(nexthop_for_each_fib6_nh);
1255
1256 static int check_src_addr(const struct in6_addr *saddr,
1257 struct netlink_ext_ack *extack)
1258 {
1259 if (!ipv6_addr_any(saddr)) {
1260 NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects");
1261 return -EINVAL;
1262 }
1263 return 0;
1264 }
1265
1266 int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
1267 struct netlink_ext_ack *extack)
1268 {
1269 struct nh_info *nhi;
1270 bool is_fdb_nh;
1271
1272 /* fib6_src is unique to a fib6_info and limits the ability to cache
1273 * routes in fib6_nh within a nexthop that is potentially shared
1274 * across multiple fib entries. If the config wants to use source
1275 * routing it can not use nexthop objects. mlxsw also does not allow
1276 * fib6_src on routes.
1277 */
1278 if (cfg && check_src_addr(&cfg->fc_src, extack) < 0)
1279 return -EINVAL;
1280
1281 if (nh->is_group) {
1282 struct nh_group *nhg;
1283
1284 nhg = rtnl_dereference(nh->nh_grp);
1285 if (nhg->has_v4)
1286 goto no_v4_nh;
1287 is_fdb_nh = nhg->fdb_nh;
1288 } else {
1289 nhi = rtnl_dereference(nh->nh_info);
1290 if (nhi->family == AF_INET)
1291 goto no_v4_nh;
1292 is_fdb_nh = nhi->fdb_nh;
1293 }
1294
1295 if (is_fdb_nh) {
1296 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
1297 return -EINVAL;
1298 }
1299
1300 return 0;
1301 no_v4_nh:
1302 NL_SET_ERR_MSG(extack, "IPv6 routes can not use an IPv4 nexthop");
1303 return -EINVAL;
1304 }
1305 EXPORT_SYMBOL_GPL(fib6_check_nexthop);
1306
1307 /* if existing nexthop has ipv6 routes linked to it, need
1308 * to verify this new spec works with ipv6
1309 */
1310 static int fib6_check_nh_list(struct nexthop *old, struct nexthop *new,
1311 struct netlink_ext_ack *extack)
1312 {
1313 struct fib6_info *f6i;
1314
1315 if (list_empty(&old->f6i_list))
1316 return 0;
1317
1318 list_for_each_entry(f6i, &old->f6i_list, nh_list) {
1319 if (check_src_addr(&f6i->fib6_src.addr, extack) < 0)
1320 return -EINVAL;
1321 }
1322
1323 return fib6_check_nexthop(new, NULL, extack);
1324 }
1325
1326 static int nexthop_check_scope(struct nh_info *nhi, u8 scope,
1327 struct netlink_ext_ack *extack)
1328 {
1329 if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) {
1330 NL_SET_ERR_MSG(extack,
1331 "Route with host scope can not have a gateway");
1332 return -EINVAL;
1333 }
1334
1335 if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) {
1336 NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop");
1337 return -EINVAL;
1338 }
1339
1340 return 0;
1341 }
1342
1343 /* Invoked by fib add code to verify nexthop by id is ok with
1344 * config for prefix; parts of fib_check_nh not done when nexthop
1345 * object is used.
1346 */
1347 int fib_check_nexthop(struct nexthop *nh, u8 scope,
1348 struct netlink_ext_ack *extack)
1349 {
1350 struct nh_info *nhi;
1351 int err = 0;
1352
1353 if (nh->is_group) {
1354 struct nh_group *nhg;
1355
1356 nhg = rtnl_dereference(nh->nh_grp);
1357 if (nhg->fdb_nh) {
1358 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
1359 err = -EINVAL;
1360 goto out;
1361 }
1362
1363 if (scope == RT_SCOPE_HOST) {
1364 NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops");
1365 err = -EINVAL;
1366 goto out;
1367 }
1368
1369 /* all nexthops in a group have the same scope */
1370 nhi = rtnl_dereference(nhg->nh_entries[0].nh->nh_info);
1371 err = nexthop_check_scope(nhi, scope, extack);
1372 } else {
1373 nhi = rtnl_dereference(nh->nh_info);
1374 if (nhi->fdb_nh) {
1375 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
1376 err = -EINVAL;
1377 goto out;
1378 }
1379 err = nexthop_check_scope(nhi, scope, extack);
1380 }
1381
1382 out:
1383 return err;
1384 }
1385
1386 static int fib_check_nh_list(struct nexthop *old, struct nexthop *new,
1387 struct netlink_ext_ack *extack)
1388 {
1389 struct fib_info *fi;
1390
1391 list_for_each_entry(fi, &old->fi_list, nh_list) {
1392 int err;
1393
1394 err = fib_check_nexthop(new, fi->fib_scope, extack);
1395 if (err)
1396 return err;
1397 }
1398 return 0;
1399 }
1400
1401 static bool nh_res_nhge_is_balanced(const struct nh_grp_entry *nhge)
1402 {
1403 return nhge->res.count_buckets == nhge->res.wants_buckets;
1404 }
1405
1406 static bool nh_res_nhge_is_ow(const struct nh_grp_entry *nhge)
1407 {
1408 return nhge->res.count_buckets > nhge->res.wants_buckets;
1409 }
1410
1411 static bool nh_res_nhge_is_uw(const struct nh_grp_entry *nhge)
1412 {
1413 return nhge->res.count_buckets < nhge->res.wants_buckets;
1414 }
1415
1416 static bool nh_res_table_is_balanced(const struct nh_res_table *res_table)
1417 {
1418 return list_empty(&res_table->uw_nh_entries);
1419 }
1420
1421 static void nh_res_bucket_unset_nh(struct nh_res_bucket *bucket)
1422 {
1423 struct nh_grp_entry *nhge;
1424
1425 if (bucket->occupied) {
1426 nhge = nh_res_dereference(bucket->nh_entry);
1427 nhge->res.count_buckets--;
1428 bucket->occupied = false;
1429 }
1430 }
1431
1432 static void nh_res_bucket_set_nh(struct nh_res_bucket *bucket,
1433 struct nh_grp_entry *nhge)
1434 {
1435 nh_res_bucket_unset_nh(bucket);
1436
1437 bucket->occupied = true;
1438 rcu_assign_pointer(bucket->nh_entry, nhge);
1439 nhge->res.count_buckets++;
1440 }
1441
1442 static bool nh_res_bucket_should_migrate(struct nh_res_table *res_table,
1443 struct nh_res_bucket *bucket,
1444 unsigned long *deadline, bool *force)
1445 {
1446 unsigned long now = jiffies;
1447 struct nh_grp_entry *nhge;
1448 unsigned long idle_point;
1449
1450 if (!bucket->occupied) {
1451 /* The bucket is not occupied, its NHGE pointer is either
1452 * NULL or obsolete. We _have to_ migrate: set force.
1453 */
1454 *force = true;
1455 return true;
1456 }
1457
1458 nhge = nh_res_dereference(bucket->nh_entry);
1459
1460 /* If the bucket is populated by an underweight or balanced
1461 * nexthop, do not migrate.
1462 */
1463 if (!nh_res_nhge_is_ow(nhge))
1464 return false;
1465
1466 /* At this point we know that the bucket is populated with an
1467 * overweight nexthop. It needs to be migrated to a new nexthop if
1468 * the idle timer of unbalanced timer expired.
1469 */
1470
1471 idle_point = nh_res_bucket_idle_point(res_table, bucket, now);
1472 if (time_after_eq(now, idle_point)) {
1473 /* The bucket is idle. We _can_ migrate: unset force. */
1474 *force = false;
1475 return true;
1476 }
1477
1478 /* Unbalanced timer of 0 means "never force". */
1479 if (res_table->unbalanced_timer) {
1480 unsigned long unb_point;
1481
1482 unb_point = nh_res_table_unb_point(res_table);
1483 if (time_after(now, unb_point)) {
1484 /* The bucket is not idle, but the unbalanced timer
1485 * expired. We _can_ migrate, but set force anyway,
1486 * so that drivers know to ignore activity reports
1487 * from the HW.
1488 */
1489 *force = true;
1490 return true;
1491 }
1492
1493 nh_res_time_set_deadline(unb_point, deadline);
1494 }
1495
1496 nh_res_time_set_deadline(idle_point, deadline);
1497 return false;
1498 }
1499
1500 static bool nh_res_bucket_migrate(struct nh_res_table *res_table,
1501 u16 bucket_index, bool notify,
1502 bool notify_nl, bool force)
1503 {
1504 struct nh_res_bucket *bucket = &res_table->nh_buckets[bucket_index];
1505 struct nh_grp_entry *new_nhge;
1506 struct netlink_ext_ack extack;
1507 int err;
1508
1509 new_nhge = list_first_entry_or_null(&res_table->uw_nh_entries,
1510 struct nh_grp_entry,
1511 res.uw_nh_entry);
1512 if (WARN_ON_ONCE(!new_nhge))
1513 /* If this function is called, "bucket" is either not
1514 * occupied, or it belongs to a next hop that is
1515 * overweight. In either case, there ought to be a
1516 * corresponding underweight next hop.
1517 */
1518 return false;
1519
1520 if (notify) {
1521 struct nh_grp_entry *old_nhge;
1522
1523 old_nhge = nh_res_dereference(bucket->nh_entry);
1524 err = call_nexthop_res_bucket_notifiers(res_table->net,
1525 res_table->nhg_id,
1526 bucket_index, force,
1527 old_nhge->nh,
1528 new_nhge->nh, &extack);
1529 if (err) {
1530 pr_err_ratelimited("%s\n", extack._msg);
1531 if (!force)
1532 return false;
1533 /* It is not possible to veto a forced replacement, so
1534 * just clear the hardware flags from the nexthop
1535 * bucket to indicate to user space that this bucket is
1536 * not correctly populated in hardware.
1537 */
1538 bucket->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP);
1539 }
1540 }
1541
1542 nh_res_bucket_set_nh(bucket, new_nhge);
1543 nh_res_bucket_set_idle(res_table, bucket);
1544
1545 if (notify_nl)
1546 nexthop_bucket_notify(res_table, bucket_index);
1547
1548 if (nh_res_nhge_is_balanced(new_nhge))
1549 list_del(&new_nhge->res.uw_nh_entry);
1550 return true;
1551 }
1552
1553 #define NH_RES_UPKEEP_DW_MINIMUM_INTERVAL (HZ / 2)
1554
1555 static void nh_res_table_upkeep(struct nh_res_table *res_table,
1556 bool notify, bool notify_nl)
1557 {
1558 unsigned long now = jiffies;
1559 unsigned long deadline;
1560 u16 i;
1561
1562 /* Deadline is the next time that upkeep should be run. It is the
1563 * earliest time at which one of the buckets might be migrated.
1564 * Start at the most pessimistic estimate: either unbalanced_timer
1565 * from now, or if there is none, idle_timer from now. For each
1566 * encountered time point, call nh_res_time_set_deadline() to
1567 * refine the estimate.
1568 */
1569 if (res_table->unbalanced_timer)
1570 deadline = now + res_table->unbalanced_timer;
1571 else
1572 deadline = now + res_table->idle_timer;
1573
1574 for (i = 0; i < res_table->num_nh_buckets; i++) {
1575 struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
1576 bool force;
1577
1578 if (nh_res_bucket_should_migrate(res_table, bucket,
1579 &deadline, &force)) {
1580 if (!nh_res_bucket_migrate(res_table, i, notify,
1581 notify_nl, force)) {
1582 unsigned long idle_point;
1583
1584 /* A driver can override the migration
1585 * decision if the HW reports that the
1586 * bucket is actually not idle. Therefore
1587 * remark the bucket as busy again and
1588 * update the deadline.
1589 */
1590 nh_res_bucket_set_busy(bucket);
1591 idle_point = nh_res_bucket_idle_point(res_table,
1592 bucket,
1593 now);
1594 nh_res_time_set_deadline(idle_point, &deadline);
1595 }
1596 }
1597 }
1598
1599 /* If the group is still unbalanced, schedule the next upkeep to
1600 * either the deadline computed above, or the minimum deadline,
1601 * whichever comes later.
1602 */
1603 if (!nh_res_table_is_balanced(res_table)) {
1604 unsigned long now = jiffies;
1605 unsigned long min_deadline;
1606
1607 min_deadline = now + NH_RES_UPKEEP_DW_MINIMUM_INTERVAL;
1608 if (time_before(deadline, min_deadline))
1609 deadline = min_deadline;
1610
1611 queue_delayed_work(system_power_efficient_wq,
1612 &res_table->upkeep_dw, deadline - now);
1613 }
1614 }
1615
1616 static void nh_res_table_upkeep_dw(struct work_struct *work)
1617 {
1618 struct delayed_work *dw = to_delayed_work(work);
1619 struct nh_res_table *res_table;
1620
1621 res_table = container_of(dw, struct nh_res_table, upkeep_dw);
1622 nh_res_table_upkeep(res_table, true, true);
1623 }
1624
1625 static void nh_res_table_cancel_upkeep(struct nh_res_table *res_table)
1626 {
1627 cancel_delayed_work_sync(&res_table->upkeep_dw);
1628 }
1629
1630 static void nh_res_group_rebalance(struct nh_group *nhg,
1631 struct nh_res_table *res_table)
1632 {
1633 int prev_upper_bound = 0;
1634 int total = 0;
1635 int w = 0;
1636 int i;
1637
1638 INIT_LIST_HEAD(&res_table->uw_nh_entries);
1639
1640 for (i = 0; i < nhg->num_nh; ++i)
1641 total += nhg->nh_entries[i].weight;
1642
1643 for (i = 0; i < nhg->num_nh; ++i) {
1644 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
1645 int upper_bound;
1646
1647 w += nhge->weight;
1648 upper_bound = DIV_ROUND_CLOSEST(res_table->num_nh_buckets * w,
1649 total);
1650 nhge->res.wants_buckets = upper_bound - prev_upper_bound;
1651 prev_upper_bound = upper_bound;
1652
1653 if (nh_res_nhge_is_uw(nhge)) {
1654 if (list_empty(&res_table->uw_nh_entries))
1655 res_table->unbalanced_since = jiffies;
1656 list_add(&nhge->res.uw_nh_entry,
1657 &res_table->uw_nh_entries);
1658 }
1659 }
1660 }
1661
1662 /* Migrate buckets in res_table so that they reference NHGE's from NHG with
1663 * the right NH ID. Set those buckets that do not have a corresponding NHGE
1664 * entry in NHG as not occupied.
1665 */
1666 static void nh_res_table_migrate_buckets(struct nh_res_table *res_table,
1667 struct nh_group *nhg)
1668 {
1669 u16 i;
1670
1671 for (i = 0; i < res_table->num_nh_buckets; i++) {
1672 struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
1673 u32 id = rtnl_dereference(bucket->nh_entry)->nh->id;
1674 bool found = false;
1675 int j;
1676
1677 for (j = 0; j < nhg->num_nh; j++) {
1678 struct nh_grp_entry *nhge = &nhg->nh_entries[j];
1679
1680 if (nhge->nh->id == id) {
1681 nh_res_bucket_set_nh(bucket, nhge);
1682 found = true;
1683 break;
1684 }
1685 }
1686
1687 if (!found)
1688 nh_res_bucket_unset_nh(bucket);
1689 }
1690 }
1691
1692 static void replace_nexthop_grp_res(struct nh_group *oldg,
1693 struct nh_group *newg)
1694 {
1695 /* For NH group replacement, the new NHG might only have a stub
1696 * hash table with 0 buckets, because the number of buckets was not
1697 * specified. For NH removal, oldg and newg both reference the same
1698 * res_table. So in any case, in the following, we want to work
1699 * with oldg->res_table.
1700 */
1701 struct nh_res_table *old_res_table = rtnl_dereference(oldg->res_table);
1702 unsigned long prev_unbalanced_since = old_res_table->unbalanced_since;
1703 bool prev_has_uw = !list_empty(&old_res_table->uw_nh_entries);
1704
1705 nh_res_table_cancel_upkeep(old_res_table);
1706 nh_res_table_migrate_buckets(old_res_table, newg);
1707 nh_res_group_rebalance(newg, old_res_table);
1708 if (prev_has_uw && !list_empty(&old_res_table->uw_nh_entries))
1709 old_res_table->unbalanced_since = prev_unbalanced_since;
1710 nh_res_table_upkeep(old_res_table, true, false);
1711 }
1712
1713 static void nh_hthr_group_rebalance(struct nh_group *nhg)
1714 {
1715 int total = 0;
1716 int w = 0;
1717 int i;
1718
1719 for (i = 0; i < nhg->num_nh; ++i)
1720 total += nhg->nh_entries[i].weight;
1721
1722 for (i = 0; i < nhg->num_nh; ++i) {
1723 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
1724 int upper_bound;
1725
1726 w += nhge->weight;
1727 upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, total) - 1;
1728 atomic_set(&nhge->hthr.upper_bound, upper_bound);
1729 }
1730 }
1731
1732 static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge,
1733 struct nl_info *nlinfo)
1734 {
1735 struct nh_grp_entry *nhges, *new_nhges;
1736 struct nexthop *nhp = nhge->nh_parent;
1737 struct netlink_ext_ack extack;
1738 struct nexthop *nh = nhge->nh;
1739 struct nh_group *nhg, *newg;
1740 int i, j, err;
1741
1742 WARN_ON(!nh);
1743
1744 nhg = rtnl_dereference(nhp->nh_grp);
1745 newg = nhg->spare;
1746
1747 /* last entry, keep it visible and remove the parent */
1748 if (nhg->num_nh == 1) {
1749 remove_nexthop(net, nhp, nlinfo);
1750 return;
1751 }
1752
1753 newg->has_v4 = false;
1754 newg->is_multipath = nhg->is_multipath;
1755 newg->hash_threshold = nhg->hash_threshold;
1756 newg->resilient = nhg->resilient;
1757 newg->fdb_nh = nhg->fdb_nh;
1758 newg->num_nh = nhg->num_nh;
1759
1760 /* copy old entries to new except the one getting removed */
1761 nhges = nhg->nh_entries;
1762 new_nhges = newg->nh_entries;
1763 for (i = 0, j = 0; i < nhg->num_nh; ++i) {
1764 struct nh_info *nhi;
1765
1766 /* current nexthop getting removed */
1767 if (nhg->nh_entries[i].nh == nh) {
1768 newg->num_nh--;
1769 continue;
1770 }
1771
1772 nhi = rtnl_dereference(nhges[i].nh->nh_info);
1773 if (nhi->family == AF_INET)
1774 newg->has_v4 = true;
1775
1776 list_del(&nhges[i].nh_list);
1777 new_nhges[j].nh_parent = nhges[i].nh_parent;
1778 new_nhges[j].nh = nhges[i].nh;
1779 new_nhges[j].weight = nhges[i].weight;
1780 list_add(&new_nhges[j].nh_list, &new_nhges[j].nh->grp_list);
1781 j++;
1782 }
1783
1784 if (newg->hash_threshold)
1785 nh_hthr_group_rebalance(newg);
1786 else if (newg->resilient)
1787 replace_nexthop_grp_res(nhg, newg);
1788
1789 rcu_assign_pointer(nhp->nh_grp, newg);
1790
1791 list_del(&nhge->nh_list);
1792 nexthop_put(nhge->nh);
1793
1794 /* Removal of a NH from a resilient group is notified through
1795 * bucket notifications.
1796 */
1797 if (newg->hash_threshold) {
1798 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, nhp,
1799 &extack);
1800 if (err)
1801 pr_err("%s\n", extack._msg);
1802 }
1803
1804 if (nlinfo)
1805 nexthop_notify(RTM_NEWNEXTHOP, nhp, nlinfo);
1806 }
1807
1808 static void remove_nexthop_from_groups(struct net *net, struct nexthop *nh,
1809 struct nl_info *nlinfo)
1810 {
1811 struct nh_grp_entry *nhge, *tmp;
1812
1813 list_for_each_entry_safe(nhge, tmp, &nh->grp_list, nh_list)
1814 remove_nh_grp_entry(net, nhge, nlinfo);
1815
1816 /* make sure all see the newly published array before releasing rtnl */
1817 synchronize_net();
1818 }
1819
1820 static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo)
1821 {
1822 struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp);
1823 struct nh_res_table *res_table;
1824 int i, num_nh = nhg->num_nh;
1825
1826 for (i = 0; i < num_nh; ++i) {
1827 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
1828
1829 if (WARN_ON(!nhge->nh))
1830 continue;
1831
1832 list_del_init(&nhge->nh_list);
1833 }
1834
1835 if (nhg->resilient) {
1836 res_table = rtnl_dereference(nhg->res_table);
1837 nh_res_table_cancel_upkeep(res_table);
1838 }
1839 }
1840
1841 /* not called for nexthop replace */
1842 static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
1843 {
1844 struct fib6_info *f6i, *tmp;
1845 bool do_flush = false;
1846 struct fib_info *fi;
1847
1848 list_for_each_entry(fi, &nh->fi_list, nh_list) {
1849 fi->fib_flags |= RTNH_F_DEAD;
1850 do_flush = true;
1851 }
1852 if (do_flush)
1853 fib_flush(net);
1854
1855 /* ip6_del_rt removes the entry from this list hence the _safe */
1856 list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) {
1857 /* __ip6_del_rt does a release, so do a hold here */
1858 fib6_info_hold(f6i);
1859 ipv6_stub->ip6_del_rt(net, f6i,
1860 !net->ipv4.sysctl_nexthop_compat_mode);
1861 }
1862 }
1863
1864 static void __remove_nexthop(struct net *net, struct nexthop *nh,
1865 struct nl_info *nlinfo)
1866 {
1867 __remove_nexthop_fib(net, nh);
1868
1869 if (nh->is_group) {
1870 remove_nexthop_group(nh, nlinfo);
1871 } else {
1872 struct nh_info *nhi;
1873
1874 nhi = rtnl_dereference(nh->nh_info);
1875 if (nhi->fib_nhc.nhc_dev)
1876 hlist_del(&nhi->dev_hash);
1877
1878 remove_nexthop_from_groups(net, nh, nlinfo);
1879 }
1880 }
1881
1882 static void remove_nexthop(struct net *net, struct nexthop *nh,
1883 struct nl_info *nlinfo)
1884 {
1885 call_nexthop_notifiers(net, NEXTHOP_EVENT_DEL, nh, NULL);
1886
1887 /* remove from the tree */
1888 rb_erase(&nh->rb_node, &net->nexthop.rb_root);
1889
1890 if (nlinfo)
1891 nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo);
1892
1893 __remove_nexthop(net, nh, nlinfo);
1894 nh_base_seq_inc(net);
1895
1896 nexthop_put(nh);
1897 }
1898
1899 /* if any FIB entries reference this nexthop, any dst entries
1900 * need to be regenerated
1901 */
1902 static void nh_rt_cache_flush(struct net *net, struct nexthop *nh)
1903 {
1904 struct fib6_info *f6i;
1905
1906 if (!list_empty(&nh->fi_list))
1907 rt_cache_flush(net);
1908
1909 list_for_each_entry(f6i, &nh->f6i_list, nh_list)
1910 ipv6_stub->fib6_update_sernum(net, f6i);
1911 }
1912
1913 static int replace_nexthop_grp(struct net *net, struct nexthop *old,
1914 struct nexthop *new, const struct nh_config *cfg,
1915 struct netlink_ext_ack *extack)
1916 {
1917 struct nh_res_table *tmp_table = NULL;
1918 struct nh_res_table *new_res_table;
1919 struct nh_res_table *old_res_table;
1920 struct nh_group *oldg, *newg;
1921 int i, err;
1922
1923 if (!new->is_group) {
1924 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop.");
1925 return -EINVAL;
1926 }
1927
1928 oldg = rtnl_dereference(old->nh_grp);
1929 newg = rtnl_dereference(new->nh_grp);
1930
1931 if (newg->hash_threshold != oldg->hash_threshold) {
1932 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with one of a different type.");
1933 return -EINVAL;
1934 }
1935
1936 if (newg->hash_threshold) {
1937 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new,
1938 extack);
1939 if (err)
1940 return err;
1941 } else if (newg->resilient) {
1942 new_res_table = rtnl_dereference(newg->res_table);
1943 old_res_table = rtnl_dereference(oldg->res_table);
1944
1945 /* Accept if num_nh_buckets was not given, but if it was
1946 * given, demand that the value be correct.
1947 */
1948 if (cfg->nh_grp_res_has_num_buckets &&
1949 cfg->nh_grp_res_num_buckets !=
1950 old_res_table->num_nh_buckets) {
1951 NL_SET_ERR_MSG(extack, "Can not change number of buckets of a resilient nexthop group.");
1952 return -EINVAL;
1953 }
1954
1955 /* Emit a pre-replace notification so that listeners could veto
1956 * a potentially unsupported configuration. Otherwise,
1957 * individual bucket replacement notifications would need to be
1958 * vetoed, which is something that should only happen if the
1959 * bucket is currently active.
1960 */
1961 err = call_nexthop_res_table_notifiers(net, new, extack);
1962 if (err)
1963 return err;
1964
1965 if (cfg->nh_grp_res_has_idle_timer)
1966 old_res_table->idle_timer = cfg->nh_grp_res_idle_timer;
1967 if (cfg->nh_grp_res_has_unbalanced_timer)
1968 old_res_table->unbalanced_timer =
1969 cfg->nh_grp_res_unbalanced_timer;
1970
1971 replace_nexthop_grp_res(oldg, newg);
1972
1973 tmp_table = new_res_table;
1974 rcu_assign_pointer(newg->res_table, old_res_table);
1975 rcu_assign_pointer(newg->spare->res_table, old_res_table);
1976 }
1977
1978 /* update parents - used by nexthop code for cleanup */
1979 for (i = 0; i < newg->num_nh; i++)
1980 newg->nh_entries[i].nh_parent = old;
1981
1982 rcu_assign_pointer(old->nh_grp, newg);
1983
1984 if (newg->resilient) {
1985 rcu_assign_pointer(oldg->res_table, tmp_table);
1986 rcu_assign_pointer(oldg->spare->res_table, tmp_table);
1987 }
1988
1989 for (i = 0; i < oldg->num_nh; i++)
1990 oldg->nh_entries[i].nh_parent = new;
1991
1992 rcu_assign_pointer(new->nh_grp, oldg);
1993
1994 return 0;
1995 }
1996
1997 static void nh_group_v4_update(struct nh_group *nhg)
1998 {
1999 struct nh_grp_entry *nhges;
2000 bool has_v4 = false;
2001 int i;
2002
2003 nhges = nhg->nh_entries;
2004 for (i = 0; i < nhg->num_nh; i++) {
2005 struct nh_info *nhi;
2006
2007 nhi = rtnl_dereference(nhges[i].nh->nh_info);
2008 if (nhi->family == AF_INET)
2009 has_v4 = true;
2010 }
2011 nhg->has_v4 = has_v4;
2012 }
2013
2014 static int replace_nexthop_single_notify_res(struct net *net,
2015 struct nh_res_table *res_table,
2016 struct nexthop *old,
2017 struct nh_info *oldi,
2018 struct nh_info *newi,
2019 struct netlink_ext_ack *extack)
2020 {
2021 u32 nhg_id = res_table->nhg_id;
2022 int err;
2023 u16 i;
2024
2025 for (i = 0; i < res_table->num_nh_buckets; i++) {
2026 struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
2027 struct nh_grp_entry *nhge;
2028
2029 nhge = rtnl_dereference(bucket->nh_entry);
2030 if (nhge->nh == old) {
2031 err = __call_nexthop_res_bucket_notifiers(net, nhg_id,
2032 i, true,
2033 oldi, newi,
2034 extack);
2035 if (err)
2036 goto err_notify;
2037 }
2038 }
2039
2040 return 0;
2041
2042 err_notify:
2043 while (i-- > 0) {
2044 struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
2045 struct nh_grp_entry *nhge;
2046
2047 nhge = rtnl_dereference(bucket->nh_entry);
2048 if (nhge->nh == old)
2049 __call_nexthop_res_bucket_notifiers(net, nhg_id, i,
2050 true, newi, oldi,
2051 extack);
2052 }
2053 return err;
2054 }
2055
2056 static int replace_nexthop_single_notify(struct net *net,
2057 struct nexthop *group_nh,
2058 struct nexthop *old,
2059 struct nh_info *oldi,
2060 struct nh_info *newi,
2061 struct netlink_ext_ack *extack)
2062 {
2063 struct nh_group *nhg = rtnl_dereference(group_nh->nh_grp);
2064 struct nh_res_table *res_table;
2065
2066 if (nhg->hash_threshold) {
2067 return call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE,
2068 group_nh, extack);
2069 } else if (nhg->resilient) {
2070 res_table = rtnl_dereference(nhg->res_table);
2071 return replace_nexthop_single_notify_res(net, res_table,
2072 old, oldi, newi,
2073 extack);
2074 }
2075
2076 return -EINVAL;
2077 }
2078
2079 static int replace_nexthop_single(struct net *net, struct nexthop *old,
2080 struct nexthop *new,
2081 struct netlink_ext_ack *extack)
2082 {
2083 u8 old_protocol, old_nh_flags;
2084 struct nh_info *oldi, *newi;
2085 struct nh_grp_entry *nhge;
2086 int err;
2087
2088 if (new->is_group) {
2089 NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group.");
2090 return -EINVAL;
2091 }
2092
2093 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new, extack);
2094 if (err)
2095 return err;
2096
2097 /* Hardware flags were set on 'old' as 'new' is not in the red-black
2098 * tree. Therefore, inherit the flags from 'old' to 'new'.
2099 */
2100 new->nh_flags |= old->nh_flags & (RTNH_F_OFFLOAD | RTNH_F_TRAP);
2101
2102 oldi = rtnl_dereference(old->nh_info);
2103 newi = rtnl_dereference(new->nh_info);
2104
2105 newi->nh_parent = old;
2106 oldi->nh_parent = new;
2107
2108 old_protocol = old->protocol;
2109 old_nh_flags = old->nh_flags;
2110
2111 old->protocol = new->protocol;
2112 old->nh_flags = new->nh_flags;
2113
2114 rcu_assign_pointer(old->nh_info, newi);
2115 rcu_assign_pointer(new->nh_info, oldi);
2116
2117 /* Send a replace notification for all the groups using the nexthop. */
2118 list_for_each_entry(nhge, &old->grp_list, nh_list) {
2119 struct nexthop *nhp = nhge->nh_parent;
2120
2121 err = replace_nexthop_single_notify(net, nhp, old, oldi, newi,
2122 extack);
2123 if (err)
2124 goto err_notify;
2125 }
2126
2127 /* When replacing an IPv4 nexthop with an IPv6 nexthop, potentially
2128 * update IPv4 indication in all the groups using the nexthop.
2129 */
2130 if (oldi->family == AF_INET && newi->family == AF_INET6) {
2131 list_for_each_entry(nhge, &old->grp_list, nh_list) {
2132 struct nexthop *nhp = nhge->nh_parent;
2133 struct nh_group *nhg;
2134
2135 nhg = rtnl_dereference(nhp->nh_grp);
2136 nh_group_v4_update(nhg);
2137 }
2138 }
2139
2140 return 0;
2141
2142 err_notify:
2143 rcu_assign_pointer(new->nh_info, newi);
2144 rcu_assign_pointer(old->nh_info, oldi);
2145 old->nh_flags = old_nh_flags;
2146 old->protocol = old_protocol;
2147 oldi->nh_parent = old;
2148 newi->nh_parent = new;
2149 list_for_each_entry_continue_reverse(nhge, &old->grp_list, nh_list) {
2150 struct nexthop *nhp = nhge->nh_parent;
2151
2152 replace_nexthop_single_notify(net, nhp, old, newi, oldi, NULL);
2153 }
2154 call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, old, extack);
2155 return err;
2156 }
2157
2158 static void __nexthop_replace_notify(struct net *net, struct nexthop *nh,
2159 struct nl_info *info)
2160 {
2161 struct fib6_info *f6i;
2162
2163 if (!list_empty(&nh->fi_list)) {
2164 struct fib_info *fi;
2165
2166 /* expectation is a few fib_info per nexthop and then
2167 * a lot of routes per fib_info. So mark the fib_info
2168 * and then walk the fib tables once
2169 */
2170 list_for_each_entry(fi, &nh->fi_list, nh_list)
2171 fi->nh_updated = true;
2172
2173 fib_info_notify_update(net, info);
2174
2175 list_for_each_entry(fi, &nh->fi_list, nh_list)
2176 fi->nh_updated = false;
2177 }
2178
2179 list_for_each_entry(f6i, &nh->f6i_list, nh_list)
2180 ipv6_stub->fib6_rt_update(net, f6i, info);
2181 }
2182
2183 /* send RTM_NEWROUTE with REPLACE flag set for all FIB entries
2184 * linked to this nexthop and for all groups that the nexthop
2185 * is a member of
2186 */
2187 static void nexthop_replace_notify(struct net *net, struct nexthop *nh,
2188 struct nl_info *info)
2189 {
2190 struct nh_grp_entry *nhge;
2191
2192 __nexthop_replace_notify(net, nh, info);
2193
2194 list_for_each_entry(nhge, &nh->grp_list, nh_list)
2195 __nexthop_replace_notify(net, nhge->nh_parent, info);
2196 }
2197
2198 static int replace_nexthop(struct net *net, struct nexthop *old,
2199 struct nexthop *new, const struct nh_config *cfg,
2200 struct netlink_ext_ack *extack)
2201 {
2202 bool new_is_reject = false;
2203 struct nh_grp_entry *nhge;
2204 int err;
2205
2206 /* check that existing FIB entries are ok with the
2207 * new nexthop definition
2208 */
2209 err = fib_check_nh_list(old, new, extack);
2210 if (err)
2211 return err;
2212
2213 err = fib6_check_nh_list(old, new, extack);
2214 if (err)
2215 return err;
2216
2217 if (!new->is_group) {
2218 struct nh_info *nhi = rtnl_dereference(new->nh_info);
2219
2220 new_is_reject = nhi->reject_nh;
2221 }
2222
2223 list_for_each_entry(nhge, &old->grp_list, nh_list) {
2224 /* if new nexthop is a blackhole, any groups using this
2225 * nexthop cannot have more than 1 path
2226 */
2227 if (new_is_reject &&
2228 nexthop_num_path(nhge->nh_parent) > 1) {
2229 NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path");
2230 return -EINVAL;
2231 }
2232
2233 err = fib_check_nh_list(nhge->nh_parent, new, extack);
2234 if (err)
2235 return err;
2236
2237 err = fib6_check_nh_list(nhge->nh_parent, new, extack);
2238 if (err)
2239 return err;
2240 }
2241
2242 if (old->is_group)
2243 err = replace_nexthop_grp(net, old, new, cfg, extack);
2244 else
2245 err = replace_nexthop_single(net, old, new, extack);
2246
2247 if (!err) {
2248 nh_rt_cache_flush(net, old);
2249
2250 __remove_nexthop(net, new, NULL);
2251 nexthop_put(new);
2252 }
2253
2254 return err;
2255 }
2256
2257 /* called with rtnl_lock held */
2258 static int insert_nexthop(struct net *net, struct nexthop *new_nh,
2259 struct nh_config *cfg, struct netlink_ext_ack *extack)
2260 {
2261 struct rb_node **pp, *parent = NULL, *next;
2262 struct rb_root *root = &net->nexthop.rb_root;
2263 bool replace = !!(cfg->nlflags & NLM_F_REPLACE);
2264 bool create = !!(cfg->nlflags & NLM_F_CREATE);
2265 u32 new_id = new_nh->id;
2266 int replace_notify = 0;
2267 int rc = -EEXIST;
2268
2269 pp = &root->rb_node;
2270 while (1) {
2271 struct nexthop *nh;
2272
2273 next = *pp;
2274 if (!next)
2275 break;
2276
2277 parent = next;
2278
2279 nh = rb_entry(parent, struct nexthop, rb_node);
2280 if (new_id < nh->id) {
2281 pp = &next->rb_left;
2282 } else if (new_id > nh->id) {
2283 pp = &next->rb_right;
2284 } else if (replace) {
2285 rc = replace_nexthop(net, nh, new_nh, cfg, extack);
2286 if (!rc) {
2287 new_nh = nh; /* send notification with old nh */
2288 replace_notify = 1;
2289 }
2290 goto out;
2291 } else {
2292 /* id already exists and not a replace */
2293 goto out;
2294 }
2295 }
2296
2297 if (replace && !create) {
2298 NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists");
2299 rc = -ENOENT;
2300 goto out;
2301 }
2302
2303 if (new_nh->is_group) {
2304 struct nh_group *nhg = rtnl_dereference(new_nh->nh_grp);
2305 struct nh_res_table *res_table;
2306
2307 if (nhg->resilient) {
2308 res_table = rtnl_dereference(nhg->res_table);
2309
2310 /* Not passing the number of buckets is OK when
2311 * replacing, but not when creating a new group.
2312 */
2313 if (!cfg->nh_grp_res_has_num_buckets) {
2314 NL_SET_ERR_MSG(extack, "Number of buckets not specified for nexthop group insertion");
2315 rc = -EINVAL;
2316 goto out;
2317 }
2318
2319 nh_res_group_rebalance(nhg, res_table);
2320
2321 /* Do not send bucket notifications, we do full
2322 * notification below.
2323 */
2324 nh_res_table_upkeep(res_table, false, false);
2325 }
2326 }
2327
2328 rb_link_node_rcu(&new_nh->rb_node, parent, pp);
2329 rb_insert_color(&new_nh->rb_node, root);
2330
2331 /* The initial insertion is a full notification for hash-threshold as
2332 * well as resilient groups.
2333 */
2334 rc = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new_nh, extack);
2335 if (rc)
2336 rb_erase(&new_nh->rb_node, &net->nexthop.rb_root);
2337
2338 out:
2339 if (!rc) {
2340 nh_base_seq_inc(net);
2341 nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo);
2342 if (replace_notify && net->ipv4.sysctl_nexthop_compat_mode)
2343 nexthop_replace_notify(net, new_nh, &cfg->nlinfo);
2344 }
2345
2346 return rc;
2347 }
2348
2349 /* rtnl */
2350 /* remove all nexthops tied to a device being deleted */
2351 static void nexthop_flush_dev(struct net_device *dev, unsigned long event)
2352 {
2353 unsigned int hash = nh_dev_hashfn(dev->ifindex);
2354 struct net *net = dev_net(dev);
2355 struct hlist_head *head = &net->nexthop.devhash[hash];
2356 struct hlist_node *n;
2357 struct nh_info *nhi;
2358
2359 hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
2360 if (nhi->fib_nhc.nhc_dev != dev)
2361 continue;
2362
2363 if (nhi->reject_nh &&
2364 (event == NETDEV_DOWN || event == NETDEV_CHANGE))
2365 continue;
2366
2367 remove_nexthop(net, nhi->nh_parent, NULL);
2368 }
2369 }
2370
2371 /* rtnl; called when net namespace is deleted */
2372 static void flush_all_nexthops(struct net *net)
2373 {
2374 struct rb_root *root = &net->nexthop.rb_root;
2375 struct rb_node *node;
2376 struct nexthop *nh;
2377
2378 while ((node = rb_first(root))) {
2379 nh = rb_entry(node, struct nexthop, rb_node);
2380 remove_nexthop(net, nh, NULL);
2381 cond_resched();
2382 }
2383 }
2384
2385 static struct nexthop *nexthop_create_group(struct net *net,
2386 struct nh_config *cfg)
2387 {
2388 struct nlattr *grps_attr = cfg->nh_grp;
2389 struct nexthop_grp *entry = nla_data(grps_attr);
2390 u16 num_nh = nla_len(grps_attr) / sizeof(*entry);
2391 struct nh_group *nhg;
2392 struct nexthop *nh;
2393 int err;
2394 int i;
2395
2396 if (WARN_ON(!num_nh))
2397 return ERR_PTR(-EINVAL);
2398
2399 nh = nexthop_alloc();
2400 if (!nh)
2401 return ERR_PTR(-ENOMEM);
2402
2403 nh->is_group = 1;
2404
2405 nhg = nexthop_grp_alloc(num_nh);
2406 if (!nhg) {
2407 kfree(nh);
2408 return ERR_PTR(-ENOMEM);
2409 }
2410
2411 /* spare group used for removals */
2412 nhg->spare = nexthop_grp_alloc(num_nh);
2413 if (!nhg->spare) {
2414 kfree(nhg);
2415 kfree(nh);
2416 return ERR_PTR(-ENOMEM);
2417 }
2418 nhg->spare->spare = nhg;
2419
2420 for (i = 0; i < nhg->num_nh; ++i) {
2421 struct nexthop *nhe;
2422 struct nh_info *nhi;
2423
2424 nhe = nexthop_find_by_id(net, entry[i].id);
2425 if (!nexthop_get(nhe)) {
2426 err = -ENOENT;
2427 goto out_no_nh;
2428 }
2429
2430 nhi = rtnl_dereference(nhe->nh_info);
2431 if (nhi->family == AF_INET)
2432 nhg->has_v4 = true;
2433
2434 nhg->nh_entries[i].nh = nhe;
2435 nhg->nh_entries[i].weight = entry[i].weight + 1;
2436 list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list);
2437 nhg->nh_entries[i].nh_parent = nh;
2438 }
2439
2440 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) {
2441 nhg->hash_threshold = 1;
2442 nhg->is_multipath = true;
2443 } else if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES) {
2444 struct nh_res_table *res_table;
2445
2446 res_table = nexthop_res_table_alloc(net, cfg->nh_id, cfg);
2447 if (!res_table) {
2448 err = -ENOMEM;
2449 goto out_no_nh;
2450 }
2451
2452 rcu_assign_pointer(nhg->spare->res_table, res_table);
2453 rcu_assign_pointer(nhg->res_table, res_table);
2454 nhg->resilient = true;
2455 nhg->is_multipath = true;
2456 }
2457
2458 WARN_ON_ONCE(nhg->hash_threshold + nhg->resilient != 1);
2459
2460 if (nhg->hash_threshold)
2461 nh_hthr_group_rebalance(nhg);
2462
2463 if (cfg->nh_fdb)
2464 nhg->fdb_nh = 1;
2465
2466 rcu_assign_pointer(nh->nh_grp, nhg);
2467
2468 return nh;
2469
2470 out_no_nh:
2471 for (i--; i >= 0; --i) {
2472 list_del(&nhg->nh_entries[i].nh_list);
2473 nexthop_put(nhg->nh_entries[i].nh);
2474 }
2475
2476 kfree(nhg->spare);
2477 kfree(nhg);
2478 kfree(nh);
2479
2480 return ERR_PTR(err);
2481 }
2482
2483 static int nh_create_ipv4(struct net *net, struct nexthop *nh,
2484 struct nh_info *nhi, struct nh_config *cfg,
2485 struct netlink_ext_ack *extack)
2486 {
2487 struct fib_nh *fib_nh = &nhi->fib_nh;
2488 struct fib_config fib_cfg = {
2489 .fc_oif = cfg->nh_ifindex,
2490 .fc_gw4 = cfg->gw.ipv4,
2491 .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0,
2492 .fc_flags = cfg->nh_flags,
2493 .fc_nlinfo = cfg->nlinfo,
2494 .fc_encap = cfg->nh_encap,
2495 .fc_encap_type = cfg->nh_encap_type,
2496 };
2497 u32 tb_id = (cfg->dev ? l3mdev_fib_table(cfg->dev) : RT_TABLE_MAIN);
2498 int err;
2499
2500 err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack);
2501 if (err) {
2502 fib_nh_release(net, fib_nh);
2503 goto out;
2504 }
2505
2506 if (nhi->fdb_nh)
2507 goto out;
2508
2509 /* sets nh_dev if successful */
2510 err = fib_check_nh(net, fib_nh, tb_id, 0, extack);
2511 if (!err) {
2512 nh->nh_flags = fib_nh->fib_nh_flags;
2513 fib_info_update_nhc_saddr(net, &fib_nh->nh_common,
2514 fib_nh->fib_nh_scope);
2515 } else {
2516 fib_nh_release(net, fib_nh);
2517 }
2518 out:
2519 return err;
2520 }
2521
2522 static int nh_create_ipv6(struct net *net, struct nexthop *nh,
2523 struct nh_info *nhi, struct nh_config *cfg,
2524 struct netlink_ext_ack *extack)
2525 {
2526 struct fib6_nh *fib6_nh = &nhi->fib6_nh;
2527 struct fib6_config fib6_cfg = {
2528 .fc_table = l3mdev_fib_table(cfg->dev),
2529 .fc_ifindex = cfg->nh_ifindex,
2530 .fc_gateway = cfg->gw.ipv6,
2531 .fc_flags = cfg->nh_flags,
2532 .fc_nlinfo = cfg->nlinfo,
2533 .fc_encap = cfg->nh_encap,
2534 .fc_encap_type = cfg->nh_encap_type,
2535 .fc_is_fdb = cfg->nh_fdb,
2536 };
2537 int err;
2538
2539 if (!ipv6_addr_any(&cfg->gw.ipv6))
2540 fib6_cfg.fc_flags |= RTF_GATEWAY;
2541
2542 /* sets nh_dev if successful */
2543 err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL,
2544 extack);
2545 if (err)
2546 ipv6_stub->fib6_nh_release(fib6_nh);
2547 else
2548 nh->nh_flags = fib6_nh->fib_nh_flags;
2549
2550 return err;
2551 }
2552
2553 static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg,
2554 struct netlink_ext_ack *extack)
2555 {
2556 struct nh_info *nhi;
2557 struct nexthop *nh;
2558 int err = 0;
2559
2560 nh = nexthop_alloc();
2561 if (!nh)
2562 return ERR_PTR(-ENOMEM);
2563
2564 nhi = kzalloc(sizeof(*nhi), GFP_KERNEL);
2565 if (!nhi) {
2566 kfree(nh);
2567 return ERR_PTR(-ENOMEM);
2568 }
2569
2570 nh->nh_flags = cfg->nh_flags;
2571 nh->net = net;
2572
2573 nhi->nh_parent = nh;
2574 nhi->family = cfg->nh_family;
2575 nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK;
2576
2577 if (cfg->nh_fdb)
2578 nhi->fdb_nh = 1;
2579
2580 if (cfg->nh_blackhole) {
2581 nhi->reject_nh = 1;
2582 cfg->nh_ifindex = net->loopback_dev->ifindex;
2583 }
2584
2585 switch (cfg->nh_family) {
2586 case AF_INET:
2587 err = nh_create_ipv4(net, nh, nhi, cfg, extack);
2588 break;
2589 case AF_INET6:
2590 err = nh_create_ipv6(net, nh, nhi, cfg, extack);
2591 break;
2592 }
2593
2594 if (err) {
2595 kfree(nhi);
2596 kfree(nh);
2597 return ERR_PTR(err);
2598 }
2599
2600 /* add the entry to the device based hash */
2601 if (!nhi->fdb_nh)
2602 nexthop_devhash_add(net, nhi);
2603
2604 rcu_assign_pointer(nh->nh_info, nhi);
2605
2606 return nh;
2607 }
2608
2609 /* called with rtnl lock held */
2610 static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg,
2611 struct netlink_ext_ack *extack)
2612 {
2613 struct nexthop *nh;
2614 int err;
2615
2616 if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) {
2617 NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
2618 return ERR_PTR(-EINVAL);
2619 }
2620
2621 if (!cfg->nh_id) {
2622 cfg->nh_id = nh_find_unused_id(net);
2623 if (!cfg->nh_id) {
2624 NL_SET_ERR_MSG(extack, "No unused id");
2625 return ERR_PTR(-EINVAL);
2626 }
2627 }
2628
2629 if (cfg->nh_grp)
2630 nh = nexthop_create_group(net, cfg);
2631 else
2632 nh = nexthop_create(net, cfg, extack);
2633
2634 if (IS_ERR(nh))
2635 return nh;
2636
2637 refcount_set(&nh->refcnt, 1);
2638 nh->id = cfg->nh_id;
2639 nh->protocol = cfg->nh_protocol;
2640 nh->net = net;
2641
2642 err = insert_nexthop(net, nh, cfg, extack);
2643 if (err) {
2644 __remove_nexthop(net, nh, NULL);
2645 nexthop_put(nh);
2646 nh = ERR_PTR(err);
2647 }
2648
2649 return nh;
2650 }
2651
2652 static int rtm_nh_get_timer(struct nlattr *attr, unsigned long fallback,
2653 unsigned long *timer_p, bool *has_p,
2654 struct netlink_ext_ack *extack)
2655 {
2656 unsigned long timer;
2657 u32 value;
2658
2659 if (!attr) {
2660 *timer_p = fallback;
2661 *has_p = false;
2662 return 0;
2663 }
2664
2665 value = nla_get_u32(attr);
2666 timer = clock_t_to_jiffies(value);
2667 if (timer == ~0UL) {
2668 NL_SET_ERR_MSG(extack, "Timer value too large");
2669 return -EINVAL;
2670 }
2671
2672 *timer_p = timer;
2673 *has_p = true;
2674 return 0;
2675 }
2676
2677 static int rtm_to_nh_config_grp_res(struct nlattr *res, struct nh_config *cfg,
2678 struct netlink_ext_ack *extack)
2679 {
2680 struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_policy_new)] = {};
2681 int err;
2682
2683 if (res) {
2684 err = nla_parse_nested(tb,
2685 ARRAY_SIZE(rtm_nh_res_policy_new) - 1,
2686 res, rtm_nh_res_policy_new, extack);
2687 if (err < 0)
2688 return err;
2689 }
2690
2691 if (tb[NHA_RES_GROUP_BUCKETS]) {
2692 cfg->nh_grp_res_num_buckets =
2693 nla_get_u16(tb[NHA_RES_GROUP_BUCKETS]);
2694 cfg->nh_grp_res_has_num_buckets = true;
2695 if (!cfg->nh_grp_res_num_buckets) {
2696 NL_SET_ERR_MSG(extack, "Number of buckets needs to be non-0");
2697 return -EINVAL;
2698 }
2699 }
2700
2701 err = rtm_nh_get_timer(tb[NHA_RES_GROUP_IDLE_TIMER],
2702 NH_RES_DEFAULT_IDLE_TIMER,
2703 &cfg->nh_grp_res_idle_timer,
2704 &cfg->nh_grp_res_has_idle_timer,
2705 extack);
2706 if (err)
2707 return err;
2708
2709 return rtm_nh_get_timer(tb[NHA_RES_GROUP_UNBALANCED_TIMER],
2710 NH_RES_DEFAULT_UNBALANCED_TIMER,
2711 &cfg->nh_grp_res_unbalanced_timer,
2712 &cfg->nh_grp_res_has_unbalanced_timer,
2713 extack);
2714 }
2715
2716 static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
2717 struct nlmsghdr *nlh, struct nh_config *cfg,
2718 struct netlink_ext_ack *extack)
2719 {
2720 struct nhmsg *nhm = nlmsg_data(nlh);
2721 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_new)];
2722 int err;
2723
2724 err = nlmsg_parse(nlh, sizeof(*nhm), tb,
2725 ARRAY_SIZE(rtm_nh_policy_new) - 1,
2726 rtm_nh_policy_new, extack);
2727 if (err < 0)
2728 return err;
2729
2730 err = -EINVAL;
2731 if (nhm->resvd || nhm->nh_scope) {
2732 NL_SET_ERR_MSG(extack, "Invalid values in ancillary header");
2733 goto out;
2734 }
2735 if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) {
2736 NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header");
2737 goto out;
2738 }
2739
2740 switch (nhm->nh_family) {
2741 case AF_INET:
2742 case AF_INET6:
2743 break;
2744 case AF_UNSPEC:
2745 if (tb[NHA_GROUP])
2746 break;
2747 fallthrough;
2748 default:
2749 NL_SET_ERR_MSG(extack, "Invalid address family");
2750 goto out;
2751 }
2752
2753 memset(cfg, 0, sizeof(*cfg));
2754 cfg->nlflags = nlh->nlmsg_flags;
2755 cfg->nlinfo.portid = NETLINK_CB(skb).portid;
2756 cfg->nlinfo.nlh = nlh;
2757 cfg->nlinfo.nl_net = net;
2758
2759 cfg->nh_family = nhm->nh_family;
2760 cfg->nh_protocol = nhm->nh_protocol;
2761 cfg->nh_flags = nhm->nh_flags;
2762
2763 if (tb[NHA_ID])
2764 cfg->nh_id = nla_get_u32(tb[NHA_ID]);
2765
2766 if (tb[NHA_FDB]) {
2767 if (tb[NHA_OIF] || tb[NHA_BLACKHOLE] ||
2768 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) {
2769 NL_SET_ERR_MSG(extack, "Fdb attribute can not be used with encap, oif or blackhole");
2770 goto out;
2771 }
2772 if (nhm->nh_flags) {
2773 NL_SET_ERR_MSG(extack, "Unsupported nexthop flags in ancillary header");
2774 goto out;
2775 }
2776 cfg->nh_fdb = nla_get_flag(tb[NHA_FDB]);
2777 }
2778
2779 if (tb[NHA_GROUP]) {
2780 if (nhm->nh_family != AF_UNSPEC) {
2781 NL_SET_ERR_MSG(extack, "Invalid family for group");
2782 goto out;
2783 }
2784 cfg->nh_grp = tb[NHA_GROUP];
2785
2786 cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH;
2787 if (tb[NHA_GROUP_TYPE])
2788 cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]);
2789
2790 if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) {
2791 NL_SET_ERR_MSG(extack, "Invalid group type");
2792 goto out;
2793 }
2794 err = nh_check_attr_group(net, tb, ARRAY_SIZE(tb),
2795 cfg->nh_grp_type, extack);
2796 if (err)
2797 goto out;
2798
2799 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES)
2800 err = rtm_to_nh_config_grp_res(tb[NHA_RES_GROUP],
2801 cfg, extack);
2802
2803 /* no other attributes should be set */
2804 goto out;
2805 }
2806
2807 if (tb[NHA_BLACKHOLE]) {
2808 if (tb[NHA_GATEWAY] || tb[NHA_OIF] ||
2809 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE] || tb[NHA_FDB]) {
2810 NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway, oif, encap or fdb");
2811 goto out;
2812 }
2813
2814 cfg->nh_blackhole = 1;
2815 err = 0;
2816 goto out;
2817 }
2818
2819 if (!cfg->nh_fdb && !tb[NHA_OIF]) {
2820 NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole and non-fdb nexthops");
2821 goto out;
2822 }
2823
2824 if (!cfg->nh_fdb && tb[NHA_OIF]) {
2825 cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
2826 if (cfg->nh_ifindex)
2827 cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
2828
2829 if (!cfg->dev) {
2830 NL_SET_ERR_MSG(extack, "Invalid device index");
2831 goto out;
2832 } else if (!(cfg->dev->flags & IFF_UP)) {
2833 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
2834 err = -ENETDOWN;
2835 goto out;
2836 } else if (!netif_carrier_ok(cfg->dev)) {
2837 NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");
2838 err = -ENETDOWN;
2839 goto out;
2840 }
2841 }
2842
2843 err = -EINVAL;
2844 if (tb[NHA_GATEWAY]) {
2845 struct nlattr *gwa = tb[NHA_GATEWAY];
2846
2847 switch (cfg->nh_family) {
2848 case AF_INET:
2849 if (nla_len(gwa) != sizeof(u32)) {
2850 NL_SET_ERR_MSG(extack, "Invalid gateway");
2851 goto out;
2852 }
2853 cfg->gw.ipv4 = nla_get_be32(gwa);
2854 break;
2855 case AF_INET6:
2856 if (nla_len(gwa) != sizeof(struct in6_addr)) {
2857 NL_SET_ERR_MSG(extack, "Invalid gateway");
2858 goto out;
2859 }
2860 cfg->gw.ipv6 = nla_get_in6_addr(gwa);
2861 break;
2862 default:
2863 NL_SET_ERR_MSG(extack,
2864 "Unknown address family for gateway");
2865 goto out;
2866 }
2867 } else {
2868 /* device only nexthop (no gateway) */
2869 if (cfg->nh_flags & RTNH_F_ONLINK) {
2870 NL_SET_ERR_MSG(extack,
2871 "ONLINK flag can not be set for nexthop without a gateway");
2872 goto out;
2873 }
2874 }
2875
2876 if (tb[NHA_ENCAP]) {
2877 cfg->nh_encap = tb[NHA_ENCAP];
2878
2879 if (!tb[NHA_ENCAP_TYPE]) {
2880 NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing");
2881 goto out;
2882 }
2883
2884 cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]);
2885 err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack);
2886 if (err < 0)
2887 goto out;
2888
2889 } else if (tb[NHA_ENCAP_TYPE]) {
2890 NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing");
2891 goto out;
2892 }
2893
2894
2895 err = 0;
2896 out:
2897 return err;
2898 }
2899
2900 /* rtnl */
2901 static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
2902 struct netlink_ext_ack *extack)
2903 {
2904 struct net *net = sock_net(skb->sk);
2905 struct nh_config cfg;
2906 struct nexthop *nh;
2907 int err;
2908
2909 err = rtm_to_nh_config(net, skb, nlh, &cfg, extack);
2910 if (!err) {
2911 nh = nexthop_add(net, &cfg, extack);
2912 if (IS_ERR(nh))
2913 err = PTR_ERR(nh);
2914 }
2915
2916 return err;
2917 }
2918
2919 static int __nh_valid_get_del_req(const struct nlmsghdr *nlh,
2920 struct nlattr **tb, u32 *id,
2921 struct netlink_ext_ack *extack)
2922 {
2923 struct nhmsg *nhm = nlmsg_data(nlh);
2924
2925 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
2926 NL_SET_ERR_MSG(extack, "Invalid values in header");
2927 return -EINVAL;
2928 }
2929
2930 if (!tb[NHA_ID]) {
2931 NL_SET_ERR_MSG(extack, "Nexthop id is missing");
2932 return -EINVAL;
2933 }
2934
2935 *id = nla_get_u32(tb[NHA_ID]);
2936 if (!(*id)) {
2937 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
2938 return -EINVAL;
2939 }
2940
2941 return 0;
2942 }
2943
2944 static int nh_valid_get_del_req(const struct nlmsghdr *nlh, u32 *id,
2945 struct netlink_ext_ack *extack)
2946 {
2947 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get)];
2948 int err;
2949
2950 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
2951 ARRAY_SIZE(rtm_nh_policy_get) - 1,
2952 rtm_nh_policy_get, extack);
2953 if (err < 0)
2954 return err;
2955
2956 return __nh_valid_get_del_req(nlh, tb, id, extack);
2957 }
2958
2959 /* rtnl */
2960 static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
2961 struct netlink_ext_ack *extack)
2962 {
2963 struct net *net = sock_net(skb->sk);
2964 struct nl_info nlinfo = {
2965 .nlh = nlh,
2966 .nl_net = net,
2967 .portid = NETLINK_CB(skb).portid,
2968 };
2969 struct nexthop *nh;
2970 int err;
2971 u32 id;
2972
2973 err = nh_valid_get_del_req(nlh, &id, extack);
2974 if (err)
2975 return err;
2976
2977 nh = nexthop_find_by_id(net, id);
2978 if (!nh)
2979 return -ENOENT;
2980
2981 remove_nexthop(net, nh, &nlinfo);
2982
2983 return 0;
2984 }
2985
2986 /* rtnl */
2987 static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2988 struct netlink_ext_ack *extack)
2989 {
2990 struct net *net = sock_net(in_skb->sk);
2991 struct sk_buff *skb = NULL;
2992 struct nexthop *nh;
2993 int err;
2994 u32 id;
2995
2996 err = nh_valid_get_del_req(nlh, &id, extack);
2997 if (err)
2998 return err;
2999
3000 err = -ENOBUFS;
3001 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3002 if (!skb)
3003 goto out;
3004
3005 err = -ENOENT;
3006 nh = nexthop_find_by_id(net, id);
3007 if (!nh)
3008 goto errout_free;
3009
3010 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid,
3011 nlh->nlmsg_seq, 0);
3012 if (err < 0) {
3013 WARN_ON(err == -EMSGSIZE);
3014 goto errout_free;
3015 }
3016
3017 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3018 out:
3019 return err;
3020 errout_free:
3021 kfree_skb(skb);
3022 goto out;
3023 }
3024
3025 struct nh_dump_filter {
3026 u32 nh_id;
3027 int dev_idx;
3028 int master_idx;
3029 bool group_filter;
3030 bool fdb_filter;
3031 u32 res_bucket_nh_id;
3032 };
3033
3034 static bool nh_dump_filtered(struct nexthop *nh,
3035 struct nh_dump_filter *filter, u8 family)
3036 {
3037 const struct net_device *dev;
3038 const struct nh_info *nhi;
3039
3040 if (filter->group_filter && !nh->is_group)
3041 return true;
3042
3043 if (!filter->dev_idx && !filter->master_idx && !family)
3044 return false;
3045
3046 if (nh->is_group)
3047 return true;
3048
3049 nhi = rtnl_dereference(nh->nh_info);
3050 if (family && nhi->family != family)
3051 return true;
3052
3053 dev = nhi->fib_nhc.nhc_dev;
3054 if (filter->dev_idx && (!dev || dev->ifindex != filter->dev_idx))
3055 return true;
3056
3057 if (filter->master_idx) {
3058 struct net_device *master;
3059
3060 if (!dev)
3061 return true;
3062
3063 master = netdev_master_upper_dev_get((struct net_device *)dev);
3064 if (!master || master->ifindex != filter->master_idx)
3065 return true;
3066 }
3067
3068 return false;
3069 }
3070
3071 static int __nh_valid_dump_req(const struct nlmsghdr *nlh, struct nlattr **tb,
3072 struct nh_dump_filter *filter,
3073 struct netlink_ext_ack *extack)
3074 {
3075 struct nhmsg *nhm;
3076 u32 idx;
3077
3078 if (tb[NHA_OIF]) {
3079 idx = nla_get_u32(tb[NHA_OIF]);
3080 if (idx > INT_MAX) {
3081 NL_SET_ERR_MSG(extack, "Invalid device index");
3082 return -EINVAL;
3083 }
3084 filter->dev_idx = idx;
3085 }
3086 if (tb[NHA_MASTER]) {
3087 idx = nla_get_u32(tb[NHA_MASTER]);
3088 if (idx > INT_MAX) {
3089 NL_SET_ERR_MSG(extack, "Invalid master device index");
3090 return -EINVAL;
3091 }
3092 filter->master_idx = idx;
3093 }
3094 filter->group_filter = nla_get_flag(tb[NHA_GROUPS]);
3095 filter->fdb_filter = nla_get_flag(tb[NHA_FDB]);
3096
3097 nhm = nlmsg_data(nlh);
3098 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
3099 NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request");
3100 return -EINVAL;
3101 }
3102
3103 return 0;
3104 }
3105
3106 static int nh_valid_dump_req(const struct nlmsghdr *nlh,
3107 struct nh_dump_filter *filter,
3108 struct netlink_callback *cb)
3109 {
3110 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump)];
3111 int err;
3112
3113 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
3114 ARRAY_SIZE(rtm_nh_policy_dump) - 1,
3115 rtm_nh_policy_dump, cb->extack);
3116 if (err < 0)
3117 return err;
3118
3119 return __nh_valid_dump_req(nlh, tb, filter, cb->extack);
3120 }
3121
3122 struct rtm_dump_nh_ctx {
3123 u32 idx;
3124 };
3125
3126 static struct rtm_dump_nh_ctx *
3127 rtm_dump_nh_ctx(struct netlink_callback *cb)
3128 {
3129 struct rtm_dump_nh_ctx *ctx = (void *)cb->ctx;
3130
3131 BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
3132 return ctx;
3133 }
3134
3135 static int rtm_dump_walk_nexthops(struct sk_buff *skb,
3136 struct netlink_callback *cb,
3137 struct rb_root *root,
3138 struct rtm_dump_nh_ctx *ctx,
3139 int (*nh_cb)(struct sk_buff *skb,
3140 struct netlink_callback *cb,
3141 struct nexthop *nh, void *data),
3142 void *data)
3143 {
3144 struct rb_node *node;
3145 int s_idx;
3146 int err;
3147
3148 s_idx = ctx->idx;
3149 for (node = rb_first(root); node; node = rb_next(node)) {
3150 struct nexthop *nh;
3151
3152 nh = rb_entry(node, struct nexthop, rb_node);
3153 if (nh->id < s_idx)
3154 continue;
3155
3156 ctx->idx = nh->id;
3157 err = nh_cb(skb, cb, nh, data);
3158 if (err)
3159 return err;
3160 }
3161
3162 ctx->idx++;
3163 return 0;
3164 }
3165
3166 static int rtm_dump_nexthop_cb(struct sk_buff *skb, struct netlink_callback *cb,
3167 struct nexthop *nh, void *data)
3168 {
3169 struct nhmsg *nhm = nlmsg_data(cb->nlh);
3170 struct nh_dump_filter *filter = data;
3171
3172 if (nh_dump_filtered(nh, filter, nhm->nh_family))
3173 return 0;
3174
3175 return nh_fill_node(skb, nh, RTM_NEWNEXTHOP,
3176 NETLINK_CB(cb->skb).portid,
3177 cb->nlh->nlmsg_seq, NLM_F_MULTI);
3178 }
3179
3180 /* rtnl */
3181 static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
3182 {
3183 struct rtm_dump_nh_ctx *ctx = rtm_dump_nh_ctx(cb);
3184 struct net *net = sock_net(skb->sk);
3185 struct rb_root *root = &net->nexthop.rb_root;
3186 struct nh_dump_filter filter = {};
3187 int err;
3188
3189 err = nh_valid_dump_req(cb->nlh, &filter, cb);
3190 if (err < 0)
3191 return err;
3192
3193 err = rtm_dump_walk_nexthops(skb, cb, root, ctx,
3194 &rtm_dump_nexthop_cb, &filter);
3195 if (err < 0) {
3196 if (likely(skb->len))
3197 goto out;
3198 goto out_err;
3199 }
3200
3201 out:
3202 err = skb->len;
3203 out_err:
3204 cb->seq = net->nexthop.seq;
3205 nl_dump_check_consistent(cb, nlmsg_hdr(skb));
3206 return err;
3207 }
3208
3209 static struct nexthop *
3210 nexthop_find_group_resilient(struct net *net, u32 id,
3211 struct netlink_ext_ack *extack)
3212 {
3213 struct nh_group *nhg;
3214 struct nexthop *nh;
3215
3216 nh = nexthop_find_by_id(net, id);
3217 if (!nh)
3218 return ERR_PTR(-ENOENT);
3219
3220 if (!nh->is_group) {
3221 NL_SET_ERR_MSG(extack, "Not a nexthop group");
3222 return ERR_PTR(-EINVAL);
3223 }
3224
3225 nhg = rtnl_dereference(nh->nh_grp);
3226 if (!nhg->resilient) {
3227 NL_SET_ERR_MSG(extack, "Nexthop group not of type resilient");
3228 return ERR_PTR(-EINVAL);
3229 }
3230
3231 return nh;
3232 }
3233
3234 static int nh_valid_dump_nhid(struct nlattr *attr, u32 *nh_id_p,
3235 struct netlink_ext_ack *extack)
3236 {
3237 u32 idx;
3238
3239 if (attr) {
3240 idx = nla_get_u32(attr);
3241 if (!idx) {
3242 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
3243 return -EINVAL;
3244 }
3245 *nh_id_p = idx;
3246 } else {
3247 *nh_id_p = 0;
3248 }
3249
3250 return 0;
3251 }
3252
3253 static int nh_valid_dump_bucket_req(const struct nlmsghdr *nlh,
3254 struct nh_dump_filter *filter,
3255 struct netlink_callback *cb)
3256 {
3257 struct nlattr *res_tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_dump)];
3258 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump_bucket)];
3259 int err;
3260
3261 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
3262 ARRAY_SIZE(rtm_nh_policy_dump_bucket) - 1,
3263 rtm_nh_policy_dump_bucket, NULL);
3264 if (err < 0)
3265 return err;
3266
3267 err = nh_valid_dump_nhid(tb[NHA_ID], &filter->nh_id, cb->extack);
3268 if (err)
3269 return err;
3270
3271 if (tb[NHA_RES_BUCKET]) {
3272 size_t max = ARRAY_SIZE(rtm_nh_res_bucket_policy_dump) - 1;
3273
3274 err = nla_parse_nested(res_tb, max,
3275 tb[NHA_RES_BUCKET],
3276 rtm_nh_res_bucket_policy_dump,
3277 cb->extack);
3278 if (err < 0)
3279 return err;
3280
3281 err = nh_valid_dump_nhid(res_tb[NHA_RES_BUCKET_NH_ID],
3282 &filter->res_bucket_nh_id,
3283 cb->extack);
3284 if (err)
3285 return err;
3286 }
3287
3288 return __nh_valid_dump_req(nlh, tb, filter, cb->extack);
3289 }
3290
3291 struct rtm_dump_res_bucket_ctx {
3292 struct rtm_dump_nh_ctx nh;
3293 u16 bucket_index;
3294 u32 done_nh_idx; /* 1 + the index of the last fully processed NH. */
3295 };
3296
3297 static struct rtm_dump_res_bucket_ctx *
3298 rtm_dump_res_bucket_ctx(struct netlink_callback *cb)
3299 {
3300 struct rtm_dump_res_bucket_ctx *ctx = (void *)cb->ctx;
3301
3302 BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
3303 return ctx;
3304 }
3305
3306 struct rtm_dump_nexthop_bucket_data {
3307 struct rtm_dump_res_bucket_ctx *ctx;
3308 struct nh_dump_filter filter;
3309 };
3310
3311 static int rtm_dump_nexthop_bucket_nh(struct sk_buff *skb,
3312 struct netlink_callback *cb,
3313 struct nexthop *nh,
3314 struct rtm_dump_nexthop_bucket_data *dd)
3315 {
3316 u32 portid = NETLINK_CB(cb->skb).portid;
3317 struct nhmsg *nhm = nlmsg_data(cb->nlh);
3318 struct nh_res_table *res_table;
3319 struct nh_group *nhg;
3320 u16 bucket_index;
3321 int err;
3322
3323 if (dd->ctx->nh.idx < dd->ctx->done_nh_idx)
3324 return 0;
3325
3326 nhg = rtnl_dereference(nh->nh_grp);
3327 res_table = rtnl_dereference(nhg->res_table);
3328 for (bucket_index = dd->ctx->bucket_index;
3329 bucket_index < res_table->num_nh_buckets;
3330 bucket_index++) {
3331 struct nh_res_bucket *bucket;
3332 struct nh_grp_entry *nhge;
3333
3334 bucket = &res_table->nh_buckets[bucket_index];
3335 nhge = rtnl_dereference(bucket->nh_entry);
3336 if (nh_dump_filtered(nhge->nh, &dd->filter, nhm->nh_family))
3337 continue;
3338
3339 if (dd->filter.res_bucket_nh_id &&
3340 dd->filter.res_bucket_nh_id != nhge->nh->id)
3341 continue;
3342
3343 err = nh_fill_res_bucket(skb, nh, bucket, bucket_index,
3344 RTM_NEWNEXTHOPBUCKET, portid,
3345 cb->nlh->nlmsg_seq, NLM_F_MULTI,
3346 cb->extack);
3347 if (err < 0) {
3348 if (likely(skb->len))
3349 goto out;
3350 goto out_err;
3351 }
3352 }
3353
3354 dd->ctx->done_nh_idx = dd->ctx->nh.idx + 1;
3355 bucket_index = 0;
3356
3357 out:
3358 err = skb->len;
3359 out_err:
3360 dd->ctx->bucket_index = bucket_index;
3361 return err;
3362 }
3363
3364 static int rtm_dump_nexthop_bucket_cb(struct sk_buff *skb,
3365 struct netlink_callback *cb,
3366 struct nexthop *nh, void *data)
3367 {
3368 struct rtm_dump_nexthop_bucket_data *dd = data;
3369 struct nh_group *nhg;
3370
3371 if (!nh->is_group)
3372 return 0;
3373
3374 nhg = rtnl_dereference(nh->nh_grp);
3375 if (!nhg->resilient)
3376 return 0;
3377
3378 return rtm_dump_nexthop_bucket_nh(skb, cb, nh, dd);
3379 }
3380
3381 /* rtnl */
3382 static int rtm_dump_nexthop_bucket(struct sk_buff *skb,
3383 struct netlink_callback *cb)
3384 {
3385 struct rtm_dump_res_bucket_ctx *ctx = rtm_dump_res_bucket_ctx(cb);
3386 struct rtm_dump_nexthop_bucket_data dd = { .ctx = ctx };
3387 struct net *net = sock_net(skb->sk);
3388 struct nexthop *nh;
3389 int err;
3390
3391 err = nh_valid_dump_bucket_req(cb->nlh, &dd.filter, cb);
3392 if (err)
3393 return err;
3394
3395 if (dd.filter.nh_id) {
3396 nh = nexthop_find_group_resilient(net, dd.filter.nh_id,
3397 cb->extack);
3398 if (IS_ERR(nh))
3399 return PTR_ERR(nh);
3400 err = rtm_dump_nexthop_bucket_nh(skb, cb, nh, &dd);
3401 } else {
3402 struct rb_root *root = &net->nexthop.rb_root;
3403
3404 err = rtm_dump_walk_nexthops(skb, cb, root, &ctx->nh,
3405 &rtm_dump_nexthop_bucket_cb, &dd);
3406 }
3407
3408 if (err < 0) {
3409 if (likely(skb->len))
3410 goto out;
3411 goto out_err;
3412 }
3413
3414 out:
3415 err = skb->len;
3416 out_err:
3417 cb->seq = net->nexthop.seq;
3418 nl_dump_check_consistent(cb, nlmsg_hdr(skb));
3419 return err;
3420 }
3421
3422 static int nh_valid_get_bucket_req_res_bucket(struct nlattr *res,
3423 u16 *bucket_index,
3424 struct netlink_ext_ack *extack)
3425 {
3426 struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_get)];
3427 int err;
3428
3429 err = nla_parse_nested(tb, ARRAY_SIZE(rtm_nh_res_bucket_policy_get) - 1,
3430 res, rtm_nh_res_bucket_policy_get, extack);
3431 if (err < 0)
3432 return err;
3433
3434 if (!tb[NHA_RES_BUCKET_INDEX]) {
3435 NL_SET_ERR_MSG(extack, "Bucket index is missing");
3436 return -EINVAL;
3437 }
3438
3439 *bucket_index = nla_get_u16(tb[NHA_RES_BUCKET_INDEX]);
3440 return 0;
3441 }
3442
3443 static int nh_valid_get_bucket_req(const struct nlmsghdr *nlh,
3444 u32 *id, u16 *bucket_index,
3445 struct netlink_ext_ack *extack)
3446 {
3447 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get_bucket)];
3448 int err;
3449
3450 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
3451 ARRAY_SIZE(rtm_nh_policy_get_bucket) - 1,
3452 rtm_nh_policy_get_bucket, extack);
3453 if (err < 0)
3454 return err;
3455
3456 err = __nh_valid_get_del_req(nlh, tb, id, extack);
3457 if (err)
3458 return err;
3459
3460 if (!tb[NHA_RES_BUCKET]) {
3461 NL_SET_ERR_MSG(extack, "Bucket information is missing");
3462 return -EINVAL;
3463 }
3464
3465 err = nh_valid_get_bucket_req_res_bucket(tb[NHA_RES_BUCKET],
3466 bucket_index, extack);
3467 if (err)
3468 return err;
3469
3470 return 0;
3471 }
3472
3473 /* rtnl */
3474 static int rtm_get_nexthop_bucket(struct sk_buff *in_skb, struct nlmsghdr *nlh,
3475 struct netlink_ext_ack *extack)
3476 {
3477 struct net *net = sock_net(in_skb->sk);
3478 struct nh_res_table *res_table;
3479 struct sk_buff *skb = NULL;
3480 struct nh_group *nhg;
3481 struct nexthop *nh;
3482 u16 bucket_index;
3483 int err;
3484 u32 id;
3485
3486 err = nh_valid_get_bucket_req(nlh, &id, &bucket_index, extack);
3487 if (err)
3488 return err;
3489
3490 nh = nexthop_find_group_resilient(net, id, extack);
3491 if (IS_ERR(nh))
3492 return PTR_ERR(nh);
3493
3494 nhg = rtnl_dereference(nh->nh_grp);
3495 res_table = rtnl_dereference(nhg->res_table);
3496 if (bucket_index >= res_table->num_nh_buckets) {
3497 NL_SET_ERR_MSG(extack, "Bucket index out of bounds");
3498 return -ENOENT;
3499 }
3500
3501 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3502 if (!skb)
3503 return -ENOBUFS;
3504
3505 err = nh_fill_res_bucket(skb, nh, &res_table->nh_buckets[bucket_index],
3506 bucket_index, RTM_NEWNEXTHOPBUCKET,
3507 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
3508 0, extack);
3509 if (err < 0) {
3510 WARN_ON(err == -EMSGSIZE);
3511 goto errout_free;
3512 }
3513
3514 return rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3515
3516 errout_free:
3517 kfree_skb(skb);
3518 return err;
3519 }
3520
3521 static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu)
3522 {
3523 unsigned int hash = nh_dev_hashfn(dev->ifindex);
3524 struct net *net = dev_net(dev);
3525 struct hlist_head *head = &net->nexthop.devhash[hash];
3526 struct hlist_node *n;
3527 struct nh_info *nhi;
3528
3529 hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
3530 if (nhi->fib_nhc.nhc_dev == dev) {
3531 if (nhi->family == AF_INET)
3532 fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu,
3533 orig_mtu);
3534 }
3535 }
3536 }
3537
3538 /* rtnl */
3539 static int nh_netdev_event(struct notifier_block *this,
3540 unsigned long event, void *ptr)
3541 {
3542 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3543 struct netdev_notifier_info_ext *info_ext;
3544
3545 switch (event) {
3546 case NETDEV_DOWN:
3547 case NETDEV_UNREGISTER:
3548 nexthop_flush_dev(dev, event);
3549 break;
3550 case NETDEV_CHANGE:
3551 if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP)))
3552 nexthop_flush_dev(dev, event);
3553 break;
3554 case NETDEV_CHANGEMTU:
3555 info_ext = ptr;
3556 nexthop_sync_mtu(dev, info_ext->ext.mtu);
3557 rt_cache_flush(dev_net(dev));
3558 break;
3559 }
3560 return NOTIFY_DONE;
3561 }
3562
3563 static struct notifier_block nh_netdev_notifier = {
3564 .notifier_call = nh_netdev_event,
3565 };
3566
3567 static int nexthops_dump(struct net *net, struct notifier_block *nb,
3568 struct netlink_ext_ack *extack)
3569 {
3570 struct rb_root *root = &net->nexthop.rb_root;
3571 struct rb_node *node;
3572 int err = 0;
3573
3574 for (node = rb_first(root); node; node = rb_next(node)) {
3575 struct nexthop *nh;
3576
3577 nh = rb_entry(node, struct nexthop, rb_node);
3578 err = call_nexthop_notifier(nb, net, NEXTHOP_EVENT_REPLACE, nh,
3579 extack);
3580 if (err)
3581 break;
3582 }
3583
3584 return err;
3585 }
3586
3587 int register_nexthop_notifier(struct net *net, struct notifier_block *nb,
3588 struct netlink_ext_ack *extack)
3589 {
3590 int err;
3591
3592 rtnl_lock();
3593 err = nexthops_dump(net, nb, extack);
3594 if (err)
3595 goto unlock;
3596 err = blocking_notifier_chain_register(&net->nexthop.notifier_chain,
3597 nb);
3598 unlock:
3599 rtnl_unlock();
3600 return err;
3601 }
3602 EXPORT_SYMBOL(register_nexthop_notifier);
3603
3604 int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb)
3605 {
3606 return blocking_notifier_chain_unregister(&net->nexthop.notifier_chain,
3607 nb);
3608 }
3609 EXPORT_SYMBOL(unregister_nexthop_notifier);
3610
3611 void nexthop_set_hw_flags(struct net *net, u32 id, bool offload, bool trap)
3612 {
3613 struct nexthop *nexthop;
3614
3615 rcu_read_lock();
3616
3617 nexthop = nexthop_find_by_id(net, id);
3618 if (!nexthop)
3619 goto out;
3620
3621 nexthop->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP);
3622 if (offload)
3623 nexthop->nh_flags |= RTNH_F_OFFLOAD;
3624 if (trap)
3625 nexthop->nh_flags |= RTNH_F_TRAP;
3626
3627 out:
3628 rcu_read_unlock();
3629 }
3630 EXPORT_SYMBOL(nexthop_set_hw_flags);
3631
3632 void nexthop_bucket_set_hw_flags(struct net *net, u32 id, u16 bucket_index,
3633 bool offload, bool trap)
3634 {
3635 struct nh_res_table *res_table;
3636 struct nh_res_bucket *bucket;
3637 struct nexthop *nexthop;
3638 struct nh_group *nhg;
3639
3640 rcu_read_lock();
3641
3642 nexthop = nexthop_find_by_id(net, id);
3643 if (!nexthop || !nexthop->is_group)
3644 goto out;
3645
3646 nhg = rcu_dereference(nexthop->nh_grp);
3647 if (!nhg->resilient)
3648 goto out;
3649
3650 if (bucket_index >= nhg->res_table->num_nh_buckets)
3651 goto out;
3652
3653 res_table = rcu_dereference(nhg->res_table);
3654 bucket = &res_table->nh_buckets[bucket_index];
3655 bucket->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP);
3656 if (offload)
3657 bucket->nh_flags |= RTNH_F_OFFLOAD;
3658 if (trap)
3659 bucket->nh_flags |= RTNH_F_TRAP;
3660
3661 out:
3662 rcu_read_unlock();
3663 }
3664 EXPORT_SYMBOL(nexthop_bucket_set_hw_flags);
3665
3666 void nexthop_res_grp_activity_update(struct net *net, u32 id, u16 num_buckets,
3667 unsigned long *activity)
3668 {
3669 struct nh_res_table *res_table;
3670 struct nexthop *nexthop;
3671 struct nh_group *nhg;
3672 u16 i;
3673
3674 rcu_read_lock();
3675
3676 nexthop = nexthop_find_by_id(net, id);
3677 if (!nexthop || !nexthop->is_group)
3678 goto out;
3679
3680 nhg = rcu_dereference(nexthop->nh_grp);
3681 if (!nhg->resilient)
3682 goto out;
3683
3684 /* Instead of silently ignoring some buckets, demand that the sizes
3685 * be the same.
3686 */
3687 res_table = rcu_dereference(nhg->res_table);
3688 if (num_buckets != res_table->num_nh_buckets)
3689 goto out;
3690
3691 for (i = 0; i < num_buckets; i++) {
3692 if (test_bit(i, activity))
3693 nh_res_bucket_set_busy(&res_table->nh_buckets[i]);
3694 }
3695
3696 out:
3697 rcu_read_unlock();
3698 }
3699 EXPORT_SYMBOL(nexthop_res_grp_activity_update);
3700
3701 static void __net_exit nexthop_net_exit(struct net *net)
3702 {
3703 rtnl_lock();
3704 flush_all_nexthops(net);
3705 rtnl_unlock();
3706 kfree(net->nexthop.devhash);
3707 }
3708
3709 static int __net_init nexthop_net_init(struct net *net)
3710 {
3711 size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE;
3712
3713 net->nexthop.rb_root = RB_ROOT;
3714 net->nexthop.devhash = kzalloc(sz, GFP_KERNEL);
3715 if (!net->nexthop.devhash)
3716 return -ENOMEM;
3717 BLOCKING_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain);
3718
3719 return 0;
3720 }
3721
3722 static struct pernet_operations nexthop_net_ops = {
3723 .init = nexthop_net_init,
3724 .exit = nexthop_net_exit,
3725 };
3726
3727 static int __init nexthop_init(void)
3728 {
3729 register_pernet_subsys(&nexthop_net_ops);
3730
3731 register_netdevice_notifier(&nh_netdev_notifier);
3732
3733 rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
3734 rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0);
3735 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop,
3736 rtm_dump_nexthop, 0);
3737
3738 rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
3739 rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
3740
3741 rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
3742 rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
3743
3744 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOPBUCKET, rtm_get_nexthop_bucket,
3745 rtm_dump_nexthop_bucket, 0);
3746
3747 return 0;
3748 }
3749 subsys_initcall(nexthop_init);
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