Loading...
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
19static void remove_nexthop(struct net *net, struct nexthop *nh,
20 struct nl_info *nlinfo);
21
22#define NH_DEV_HASHBITS 8
23#define NH_DEV_HASHSIZE (1U << NH_DEV_HASHBITS)
24
25static const struct nla_policy rtm_nh_policy[NHA_MAX + 1] = {
26 [NHA_ID] = { .type = NLA_U32 },
27 [NHA_GROUP] = { .type = NLA_BINARY },
28 [NHA_GROUP_TYPE] = { .type = NLA_U16 },
29 [NHA_BLACKHOLE] = { .type = NLA_FLAG },
30 [NHA_OIF] = { .type = NLA_U32 },
31 [NHA_GATEWAY] = { .type = NLA_BINARY },
32 [NHA_ENCAP_TYPE] = { .type = NLA_U16 },
33 [NHA_ENCAP] = { .type = NLA_NESTED },
34 [NHA_GROUPS] = { .type = NLA_FLAG },
35 [NHA_MASTER] = { .type = NLA_U32 },
36 [NHA_FDB] = { .type = NLA_FLAG },
37};
38
39static int call_nexthop_notifiers(struct net *net,
40 enum nexthop_event_type event_type,
41 struct nexthop *nh)
42{
43 int err;
44
45 err = atomic_notifier_call_chain(&net->nexthop.notifier_chain,
46 event_type, nh);
47 return notifier_to_errno(err);
48}
49
50static unsigned int nh_dev_hashfn(unsigned int val)
51{
52 unsigned int mask = NH_DEV_HASHSIZE - 1;
53
54 return (val ^
55 (val >> NH_DEV_HASHBITS) ^
56 (val >> (NH_DEV_HASHBITS * 2))) & mask;
57}
58
59static void nexthop_devhash_add(struct net *net, struct nh_info *nhi)
60{
61 struct net_device *dev = nhi->fib_nhc.nhc_dev;
62 struct hlist_head *head;
63 unsigned int hash;
64
65 WARN_ON(!dev);
66
67 hash = nh_dev_hashfn(dev->ifindex);
68 head = &net->nexthop.devhash[hash];
69 hlist_add_head(&nhi->dev_hash, head);
70}
71
72static void nexthop_free_mpath(struct nexthop *nh)
73{
74 struct nh_group *nhg;
75 int i;
76
77 nhg = rcu_dereference_raw(nh->nh_grp);
78 for (i = 0; i < nhg->num_nh; ++i) {
79 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
80
81 WARN_ON(!list_empty(&nhge->nh_list));
82 nexthop_put(nhge->nh);
83 }
84
85 WARN_ON(nhg->spare == nhg);
86
87 kfree(nhg->spare);
88 kfree(nhg);
89}
90
91static void nexthop_free_single(struct nexthop *nh)
92{
93 struct nh_info *nhi;
94
95 nhi = rcu_dereference_raw(nh->nh_info);
96 switch (nhi->family) {
97 case AF_INET:
98 fib_nh_release(nh->net, &nhi->fib_nh);
99 break;
100 case AF_INET6:
101 ipv6_stub->fib6_nh_release(&nhi->fib6_nh);
102 break;
103 }
104 kfree(nhi);
105}
106
107void nexthop_free_rcu(struct rcu_head *head)
108{
109 struct nexthop *nh = container_of(head, struct nexthop, rcu);
110
111 if (nh->is_group)
112 nexthop_free_mpath(nh);
113 else
114 nexthop_free_single(nh);
115
116 kfree(nh);
117}
118EXPORT_SYMBOL_GPL(nexthop_free_rcu);
119
120static struct nexthop *nexthop_alloc(void)
121{
122 struct nexthop *nh;
123
124 nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL);
125 if (nh) {
126 INIT_LIST_HEAD(&nh->fi_list);
127 INIT_LIST_HEAD(&nh->f6i_list);
128 INIT_LIST_HEAD(&nh->grp_list);
129 INIT_LIST_HEAD(&nh->fdb_list);
130 }
131 return nh;
132}
133
134static struct nh_group *nexthop_grp_alloc(u16 num_nh)
135{
136 size_t sz = offsetof(struct nexthop, nh_grp)
137 + sizeof(struct nh_group)
138 + sizeof(struct nh_grp_entry) * num_nh;
139 struct nh_group *nhg;
140
141 nhg = kzalloc(sz, GFP_KERNEL);
142 if (nhg)
143 nhg->num_nh = num_nh;
144
145 return nhg;
146}
147
148static void nh_base_seq_inc(struct net *net)
149{
150 while (++net->nexthop.seq == 0)
151 ;
152}
153
154/* no reference taken; rcu lock or rtnl must be held */
155struct nexthop *nexthop_find_by_id(struct net *net, u32 id)
156{
157 struct rb_node **pp, *parent = NULL, *next;
158
159 pp = &net->nexthop.rb_root.rb_node;
160 while (1) {
161 struct nexthop *nh;
162
163 next = rcu_dereference_raw(*pp);
164 if (!next)
165 break;
166 parent = next;
167
168 nh = rb_entry(parent, struct nexthop, rb_node);
169 if (id < nh->id)
170 pp = &next->rb_left;
171 else if (id > nh->id)
172 pp = &next->rb_right;
173 else
174 return nh;
175 }
176 return NULL;
177}
178EXPORT_SYMBOL_GPL(nexthop_find_by_id);
179
180/* used for auto id allocation; called with rtnl held */
181static u32 nh_find_unused_id(struct net *net)
182{
183 u32 id_start = net->nexthop.last_id_allocated;
184
185 while (1) {
186 net->nexthop.last_id_allocated++;
187 if (net->nexthop.last_id_allocated == id_start)
188 break;
189
190 if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated))
191 return net->nexthop.last_id_allocated;
192 }
193 return 0;
194}
195
196static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg)
197{
198 struct nexthop_grp *p;
199 size_t len = nhg->num_nh * sizeof(*p);
200 struct nlattr *nla;
201 u16 group_type = 0;
202 int i;
203
204 if (nhg->mpath)
205 group_type = NEXTHOP_GRP_TYPE_MPATH;
206
207 if (nla_put_u16(skb, NHA_GROUP_TYPE, group_type))
208 goto nla_put_failure;
209
210 nla = nla_reserve(skb, NHA_GROUP, len);
211 if (!nla)
212 goto nla_put_failure;
213
214 p = nla_data(nla);
215 for (i = 0; i < nhg->num_nh; ++i) {
216 p->id = nhg->nh_entries[i].nh->id;
217 p->weight = nhg->nh_entries[i].weight - 1;
218 p += 1;
219 }
220
221 return 0;
222
223nla_put_failure:
224 return -EMSGSIZE;
225}
226
227static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh,
228 int event, u32 portid, u32 seq, unsigned int nlflags)
229{
230 struct fib6_nh *fib6_nh;
231 struct fib_nh *fib_nh;
232 struct nlmsghdr *nlh;
233 struct nh_info *nhi;
234 struct nhmsg *nhm;
235
236 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
237 if (!nlh)
238 return -EMSGSIZE;
239
240 nhm = nlmsg_data(nlh);
241 nhm->nh_family = AF_UNSPEC;
242 nhm->nh_flags = nh->nh_flags;
243 nhm->nh_protocol = nh->protocol;
244 nhm->nh_scope = 0;
245 nhm->resvd = 0;
246
247 if (nla_put_u32(skb, NHA_ID, nh->id))
248 goto nla_put_failure;
249
250 if (nh->is_group) {
251 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
252
253 if (nhg->fdb_nh && nla_put_flag(skb, NHA_FDB))
254 goto nla_put_failure;
255 if (nla_put_nh_group(skb, nhg))
256 goto nla_put_failure;
257 goto out;
258 }
259
260 nhi = rtnl_dereference(nh->nh_info);
261 nhm->nh_family = nhi->family;
262 if (nhi->reject_nh) {
263 if (nla_put_flag(skb, NHA_BLACKHOLE))
264 goto nla_put_failure;
265 goto out;
266 } else if (nhi->fdb_nh) {
267 if (nla_put_flag(skb, NHA_FDB))
268 goto nla_put_failure;
269 } else {
270 const struct net_device *dev;
271
272 dev = nhi->fib_nhc.nhc_dev;
273 if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex))
274 goto nla_put_failure;
275 }
276
277 nhm->nh_scope = nhi->fib_nhc.nhc_scope;
278 switch (nhi->family) {
279 case AF_INET:
280 fib_nh = &nhi->fib_nh;
281 if (fib_nh->fib_nh_gw_family &&
282 nla_put_u32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4))
283 goto nla_put_failure;
284 break;
285
286 case AF_INET6:
287 fib6_nh = &nhi->fib6_nh;
288 if (fib6_nh->fib_nh_gw_family &&
289 nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->fib_nh_gw6))
290 goto nla_put_failure;
291 break;
292 }
293
294 if (nhi->fib_nhc.nhc_lwtstate &&
295 lwtunnel_fill_encap(skb, nhi->fib_nhc.nhc_lwtstate,
296 NHA_ENCAP, NHA_ENCAP_TYPE) < 0)
297 goto nla_put_failure;
298
299out:
300 nlmsg_end(skb, nlh);
301 return 0;
302
303nla_put_failure:
304 nlmsg_cancel(skb, nlh);
305 return -EMSGSIZE;
306}
307
308static size_t nh_nlmsg_size_grp(struct nexthop *nh)
309{
310 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
311 size_t sz = sizeof(struct nexthop_grp) * nhg->num_nh;
312
313 return nla_total_size(sz) +
314 nla_total_size(2); /* NHA_GROUP_TYPE */
315}
316
317static size_t nh_nlmsg_size_single(struct nexthop *nh)
318{
319 struct nh_info *nhi = rtnl_dereference(nh->nh_info);
320 size_t sz;
321
322 /* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE
323 * are mutually exclusive
324 */
325 sz = nla_total_size(4); /* NHA_OIF */
326
327 switch (nhi->family) {
328 case AF_INET:
329 if (nhi->fib_nh.fib_nh_gw_family)
330 sz += nla_total_size(4); /* NHA_GATEWAY */
331 break;
332
333 case AF_INET6:
334 /* NHA_GATEWAY */
335 if (nhi->fib6_nh.fib_nh_gw_family)
336 sz += nla_total_size(sizeof(const struct in6_addr));
337 break;
338 }
339
340 if (nhi->fib_nhc.nhc_lwtstate) {
341 sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate);
342 sz += nla_total_size(2); /* NHA_ENCAP_TYPE */
343 }
344
345 return sz;
346}
347
348static size_t nh_nlmsg_size(struct nexthop *nh)
349{
350 size_t sz = NLMSG_ALIGN(sizeof(struct nhmsg));
351
352 sz += nla_total_size(4); /* NHA_ID */
353
354 if (nh->is_group)
355 sz += nh_nlmsg_size_grp(nh);
356 else
357 sz += nh_nlmsg_size_single(nh);
358
359 return sz;
360}
361
362static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info)
363{
364 unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0;
365 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
366 struct sk_buff *skb;
367 int err = -ENOBUFS;
368
369 skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any());
370 if (!skb)
371 goto errout;
372
373 err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags);
374 if (err < 0) {
375 /* -EMSGSIZE implies BUG in nh_nlmsg_size() */
376 WARN_ON(err == -EMSGSIZE);
377 kfree_skb(skb);
378 goto errout;
379 }
380
381 rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_NEXTHOP,
382 info->nlh, gfp_any());
383 return;
384errout:
385 if (err < 0)
386 rtnl_set_sk_err(info->nl_net, RTNLGRP_NEXTHOP, err);
387}
388
389static bool valid_group_nh(struct nexthop *nh, unsigned int npaths,
390 bool *is_fdb, struct netlink_ext_ack *extack)
391{
392 if (nh->is_group) {
393 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
394
395 /* nested multipath (group within a group) is not
396 * supported
397 */
398 if (nhg->mpath) {
399 NL_SET_ERR_MSG(extack,
400 "Multipath group can not be a nexthop within a group");
401 return false;
402 }
403 *is_fdb = nhg->fdb_nh;
404 } else {
405 struct nh_info *nhi = rtnl_dereference(nh->nh_info);
406
407 if (nhi->reject_nh && npaths > 1) {
408 NL_SET_ERR_MSG(extack,
409 "Blackhole nexthop can not be used in a group with more than 1 path");
410 return false;
411 }
412 *is_fdb = nhi->fdb_nh;
413 }
414
415 return true;
416}
417
418static int nh_check_attr_fdb_group(struct nexthop *nh, u8 *nh_family,
419 struct netlink_ext_ack *extack)
420{
421 struct nh_info *nhi;
422
423 nhi = rtnl_dereference(nh->nh_info);
424
425 if (!nhi->fdb_nh) {
426 NL_SET_ERR_MSG(extack, "FDB nexthop group can only have fdb nexthops");
427 return -EINVAL;
428 }
429
430 if (*nh_family == AF_UNSPEC) {
431 *nh_family = nhi->family;
432 } else if (*nh_family != nhi->family) {
433 NL_SET_ERR_MSG(extack, "FDB nexthop group cannot have mixed family nexthops");
434 return -EINVAL;
435 }
436
437 return 0;
438}
439
440static int nh_check_attr_group(struct net *net, struct nlattr *tb[],
441 struct netlink_ext_ack *extack)
442{
443 unsigned int len = nla_len(tb[NHA_GROUP]);
444 u8 nh_family = AF_UNSPEC;
445 struct nexthop_grp *nhg;
446 unsigned int i, j;
447 u8 nhg_fdb = 0;
448
449 if (!len || len & (sizeof(struct nexthop_grp) - 1)) {
450 NL_SET_ERR_MSG(extack,
451 "Invalid length for nexthop group attribute");
452 return -EINVAL;
453 }
454
455 /* convert len to number of nexthop ids */
456 len /= sizeof(*nhg);
457
458 nhg = nla_data(tb[NHA_GROUP]);
459 for (i = 0; i < len; ++i) {
460 if (nhg[i].resvd1 || nhg[i].resvd2) {
461 NL_SET_ERR_MSG(extack, "Reserved fields in nexthop_grp must be 0");
462 return -EINVAL;
463 }
464 if (nhg[i].weight > 254) {
465 NL_SET_ERR_MSG(extack, "Invalid value for weight");
466 return -EINVAL;
467 }
468 for (j = i + 1; j < len; ++j) {
469 if (nhg[i].id == nhg[j].id) {
470 NL_SET_ERR_MSG(extack, "Nexthop id can not be used twice in a group");
471 return -EINVAL;
472 }
473 }
474 }
475
476 if (tb[NHA_FDB])
477 nhg_fdb = 1;
478 nhg = nla_data(tb[NHA_GROUP]);
479 for (i = 0; i < len; ++i) {
480 struct nexthop *nh;
481 bool is_fdb_nh;
482
483 nh = nexthop_find_by_id(net, nhg[i].id);
484 if (!nh) {
485 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
486 return -EINVAL;
487 }
488 if (!valid_group_nh(nh, len, &is_fdb_nh, extack))
489 return -EINVAL;
490
491 if (nhg_fdb && nh_check_attr_fdb_group(nh, &nh_family, extack))
492 return -EINVAL;
493
494 if (!nhg_fdb && is_fdb_nh) {
495 NL_SET_ERR_MSG(extack, "Non FDB nexthop group cannot have fdb nexthops");
496 return -EINVAL;
497 }
498 }
499 for (i = NHA_GROUP_TYPE + 1; i < __NHA_MAX; ++i) {
500 if (!tb[i])
501 continue;
502 if (tb[NHA_FDB])
503 continue;
504 NL_SET_ERR_MSG(extack,
505 "No other attributes can be set in nexthop groups");
506 return -EINVAL;
507 }
508
509 return 0;
510}
511
512static bool ipv6_good_nh(const struct fib6_nh *nh)
513{
514 int state = NUD_REACHABLE;
515 struct neighbour *n;
516
517 rcu_read_lock_bh();
518
519 n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6);
520 if (n)
521 state = n->nud_state;
522
523 rcu_read_unlock_bh();
524
525 return !!(state & NUD_VALID);
526}
527
528static bool ipv4_good_nh(const struct fib_nh *nh)
529{
530 int state = NUD_REACHABLE;
531 struct neighbour *n;
532
533 rcu_read_lock_bh();
534
535 n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev,
536 (__force u32)nh->fib_nh_gw4);
537 if (n)
538 state = n->nud_state;
539
540 rcu_read_unlock_bh();
541
542 return !!(state & NUD_VALID);
543}
544
545struct nexthop *nexthop_select_path(struct nexthop *nh, int hash)
546{
547 struct nexthop *rc = NULL;
548 struct nh_group *nhg;
549 int i;
550
551 if (!nh->is_group)
552 return nh;
553
554 nhg = rcu_dereference(nh->nh_grp);
555 for (i = 0; i < nhg->num_nh; ++i) {
556 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
557 struct nh_info *nhi;
558
559 if (hash > atomic_read(&nhge->upper_bound))
560 continue;
561
562 nhi = rcu_dereference(nhge->nh->nh_info);
563 if (nhi->fdb_nh)
564 return nhge->nh;
565
566 /* nexthops always check if it is good and does
567 * not rely on a sysctl for this behavior
568 */
569 switch (nhi->family) {
570 case AF_INET:
571 if (ipv4_good_nh(&nhi->fib_nh))
572 return nhge->nh;
573 break;
574 case AF_INET6:
575 if (ipv6_good_nh(&nhi->fib6_nh))
576 return nhge->nh;
577 break;
578 }
579
580 if (!rc)
581 rc = nhge->nh;
582 }
583
584 return rc;
585}
586EXPORT_SYMBOL_GPL(nexthop_select_path);
587
588int nexthop_for_each_fib6_nh(struct nexthop *nh,
589 int (*cb)(struct fib6_nh *nh, void *arg),
590 void *arg)
591{
592 struct nh_info *nhi;
593 int err;
594
595 if (nh->is_group) {
596 struct nh_group *nhg;
597 int i;
598
599 nhg = rcu_dereference_rtnl(nh->nh_grp);
600 for (i = 0; i < nhg->num_nh; i++) {
601 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
602
603 nhi = rcu_dereference_rtnl(nhge->nh->nh_info);
604 err = cb(&nhi->fib6_nh, arg);
605 if (err)
606 return err;
607 }
608 } else {
609 nhi = rcu_dereference_rtnl(nh->nh_info);
610 err = cb(&nhi->fib6_nh, arg);
611 if (err)
612 return err;
613 }
614
615 return 0;
616}
617EXPORT_SYMBOL_GPL(nexthop_for_each_fib6_nh);
618
619static int check_src_addr(const struct in6_addr *saddr,
620 struct netlink_ext_ack *extack)
621{
622 if (!ipv6_addr_any(saddr)) {
623 NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects");
624 return -EINVAL;
625 }
626 return 0;
627}
628
629int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
630 struct netlink_ext_ack *extack)
631{
632 struct nh_info *nhi;
633 bool is_fdb_nh;
634
635 /* fib6_src is unique to a fib6_info and limits the ability to cache
636 * routes in fib6_nh within a nexthop that is potentially shared
637 * across multiple fib entries. If the config wants to use source
638 * routing it can not use nexthop objects. mlxsw also does not allow
639 * fib6_src on routes.
640 */
641 if (cfg && check_src_addr(&cfg->fc_src, extack) < 0)
642 return -EINVAL;
643
644 if (nh->is_group) {
645 struct nh_group *nhg;
646
647 nhg = rtnl_dereference(nh->nh_grp);
648 if (nhg->has_v4)
649 goto no_v4_nh;
650 is_fdb_nh = nhg->fdb_nh;
651 } else {
652 nhi = rtnl_dereference(nh->nh_info);
653 if (nhi->family == AF_INET)
654 goto no_v4_nh;
655 is_fdb_nh = nhi->fdb_nh;
656 }
657
658 if (is_fdb_nh) {
659 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
660 return -EINVAL;
661 }
662
663 return 0;
664no_v4_nh:
665 NL_SET_ERR_MSG(extack, "IPv6 routes can not use an IPv4 nexthop");
666 return -EINVAL;
667}
668EXPORT_SYMBOL_GPL(fib6_check_nexthop);
669
670/* if existing nexthop has ipv6 routes linked to it, need
671 * to verify this new spec works with ipv6
672 */
673static int fib6_check_nh_list(struct nexthop *old, struct nexthop *new,
674 struct netlink_ext_ack *extack)
675{
676 struct fib6_info *f6i;
677
678 if (list_empty(&old->f6i_list))
679 return 0;
680
681 list_for_each_entry(f6i, &old->f6i_list, nh_list) {
682 if (check_src_addr(&f6i->fib6_src.addr, extack) < 0)
683 return -EINVAL;
684 }
685
686 return fib6_check_nexthop(new, NULL, extack);
687}
688
689static int nexthop_check_scope(struct nh_info *nhi, u8 scope,
690 struct netlink_ext_ack *extack)
691{
692 if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) {
693 NL_SET_ERR_MSG(extack,
694 "Route with host scope can not have a gateway");
695 return -EINVAL;
696 }
697
698 if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) {
699 NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop");
700 return -EINVAL;
701 }
702
703 return 0;
704}
705
706/* Invoked by fib add code to verify nexthop by id is ok with
707 * config for prefix; parts of fib_check_nh not done when nexthop
708 * object is used.
709 */
710int fib_check_nexthop(struct nexthop *nh, u8 scope,
711 struct netlink_ext_ack *extack)
712{
713 struct nh_info *nhi;
714 int err = 0;
715
716 if (nh->is_group) {
717 struct nh_group *nhg;
718
719 nhg = rtnl_dereference(nh->nh_grp);
720 if (nhg->fdb_nh) {
721 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
722 err = -EINVAL;
723 goto out;
724 }
725
726 if (scope == RT_SCOPE_HOST) {
727 NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops");
728 err = -EINVAL;
729 goto out;
730 }
731
732 /* all nexthops in a group have the same scope */
733 nhi = rtnl_dereference(nhg->nh_entries[0].nh->nh_info);
734 err = nexthop_check_scope(nhi, scope, extack);
735 } else {
736 nhi = rtnl_dereference(nh->nh_info);
737 if (nhi->fdb_nh) {
738 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
739 err = -EINVAL;
740 goto out;
741 }
742 err = nexthop_check_scope(nhi, scope, extack);
743 }
744
745out:
746 return err;
747}
748
749static int fib_check_nh_list(struct nexthop *old, struct nexthop *new,
750 struct netlink_ext_ack *extack)
751{
752 struct fib_info *fi;
753
754 list_for_each_entry(fi, &old->fi_list, nh_list) {
755 int err;
756
757 err = fib_check_nexthop(new, fi->fib_scope, extack);
758 if (err)
759 return err;
760 }
761 return 0;
762}
763
764static void nh_group_rebalance(struct nh_group *nhg)
765{
766 int total = 0;
767 int w = 0;
768 int i;
769
770 for (i = 0; i < nhg->num_nh; ++i)
771 total += nhg->nh_entries[i].weight;
772
773 for (i = 0; i < nhg->num_nh; ++i) {
774 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
775 int upper_bound;
776
777 w += nhge->weight;
778 upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, total) - 1;
779 atomic_set(&nhge->upper_bound, upper_bound);
780 }
781}
782
783static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge,
784 struct nl_info *nlinfo)
785{
786 struct nh_grp_entry *nhges, *new_nhges;
787 struct nexthop *nhp = nhge->nh_parent;
788 struct nexthop *nh = nhge->nh;
789 struct nh_group *nhg, *newg;
790 int i, j;
791
792 WARN_ON(!nh);
793
794 nhg = rtnl_dereference(nhp->nh_grp);
795 newg = nhg->spare;
796
797 /* last entry, keep it visible and remove the parent */
798 if (nhg->num_nh == 1) {
799 remove_nexthop(net, nhp, nlinfo);
800 return;
801 }
802
803 newg->has_v4 = nhg->has_v4;
804 newg->mpath = nhg->mpath;
805 newg->fdb_nh = nhg->fdb_nh;
806 newg->num_nh = nhg->num_nh;
807
808 /* copy old entries to new except the one getting removed */
809 nhges = nhg->nh_entries;
810 new_nhges = newg->nh_entries;
811 for (i = 0, j = 0; i < nhg->num_nh; ++i) {
812 /* current nexthop getting removed */
813 if (nhg->nh_entries[i].nh == nh) {
814 newg->num_nh--;
815 continue;
816 }
817
818 list_del(&nhges[i].nh_list);
819 new_nhges[j].nh_parent = nhges[i].nh_parent;
820 new_nhges[j].nh = nhges[i].nh;
821 new_nhges[j].weight = nhges[i].weight;
822 list_add(&new_nhges[j].nh_list, &new_nhges[j].nh->grp_list);
823 j++;
824 }
825
826 nh_group_rebalance(newg);
827 rcu_assign_pointer(nhp->nh_grp, newg);
828
829 list_del(&nhge->nh_list);
830 nexthop_put(nhge->nh);
831
832 if (nlinfo)
833 nexthop_notify(RTM_NEWNEXTHOP, nhp, nlinfo);
834}
835
836static void remove_nexthop_from_groups(struct net *net, struct nexthop *nh,
837 struct nl_info *nlinfo)
838{
839 struct nh_grp_entry *nhge, *tmp;
840
841 list_for_each_entry_safe(nhge, tmp, &nh->grp_list, nh_list)
842 remove_nh_grp_entry(net, nhge, nlinfo);
843
844 /* make sure all see the newly published array before releasing rtnl */
845 synchronize_rcu();
846}
847
848static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo)
849{
850 struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp);
851 int i, num_nh = nhg->num_nh;
852
853 for (i = 0; i < num_nh; ++i) {
854 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
855
856 if (WARN_ON(!nhge->nh))
857 continue;
858
859 list_del_init(&nhge->nh_list);
860 }
861}
862
863/* not called for nexthop replace */
864static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
865{
866 struct fib6_info *f6i, *tmp;
867 bool do_flush = false;
868 struct fib_info *fi;
869
870 call_nexthop_notifiers(net, NEXTHOP_EVENT_DEL, nh);
871
872 list_for_each_entry(fi, &nh->fi_list, nh_list) {
873 fi->fib_flags |= RTNH_F_DEAD;
874 do_flush = true;
875 }
876 if (do_flush)
877 fib_flush(net);
878
879 /* ip6_del_rt removes the entry from this list hence the _safe */
880 list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) {
881 /* __ip6_del_rt does a release, so do a hold here */
882 fib6_info_hold(f6i);
883 ipv6_stub->ip6_del_rt(net, f6i,
884 !net->ipv4.sysctl_nexthop_compat_mode);
885 }
886}
887
888static void __remove_nexthop(struct net *net, struct nexthop *nh,
889 struct nl_info *nlinfo)
890{
891 __remove_nexthop_fib(net, nh);
892
893 if (nh->is_group) {
894 remove_nexthop_group(nh, nlinfo);
895 } else {
896 struct nh_info *nhi;
897
898 nhi = rtnl_dereference(nh->nh_info);
899 if (nhi->fib_nhc.nhc_dev)
900 hlist_del(&nhi->dev_hash);
901
902 remove_nexthop_from_groups(net, nh, nlinfo);
903 }
904}
905
906static void remove_nexthop(struct net *net, struct nexthop *nh,
907 struct nl_info *nlinfo)
908{
909 /* remove from the tree */
910 rb_erase(&nh->rb_node, &net->nexthop.rb_root);
911
912 if (nlinfo)
913 nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo);
914
915 __remove_nexthop(net, nh, nlinfo);
916 nh_base_seq_inc(net);
917
918 nexthop_put(nh);
919}
920
921/* if any FIB entries reference this nexthop, any dst entries
922 * need to be regenerated
923 */
924static void nh_rt_cache_flush(struct net *net, struct nexthop *nh)
925{
926 struct fib6_info *f6i;
927
928 if (!list_empty(&nh->fi_list))
929 rt_cache_flush(net);
930
931 list_for_each_entry(f6i, &nh->f6i_list, nh_list)
932 ipv6_stub->fib6_update_sernum(net, f6i);
933}
934
935static int replace_nexthop_grp(struct net *net, struct nexthop *old,
936 struct nexthop *new,
937 struct netlink_ext_ack *extack)
938{
939 struct nh_group *oldg, *newg;
940 int i;
941
942 if (!new->is_group) {
943 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop.");
944 return -EINVAL;
945 }
946
947 oldg = rtnl_dereference(old->nh_grp);
948 newg = rtnl_dereference(new->nh_grp);
949
950 /* update parents - used by nexthop code for cleanup */
951 for (i = 0; i < newg->num_nh; i++)
952 newg->nh_entries[i].nh_parent = old;
953
954 rcu_assign_pointer(old->nh_grp, newg);
955
956 for (i = 0; i < oldg->num_nh; i++)
957 oldg->nh_entries[i].nh_parent = new;
958
959 rcu_assign_pointer(new->nh_grp, oldg);
960
961 return 0;
962}
963
964static int replace_nexthop_single(struct net *net, struct nexthop *old,
965 struct nexthop *new,
966 struct netlink_ext_ack *extack)
967{
968 struct nh_info *oldi, *newi;
969
970 if (new->is_group) {
971 NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group.");
972 return -EINVAL;
973 }
974
975 oldi = rtnl_dereference(old->nh_info);
976 newi = rtnl_dereference(new->nh_info);
977
978 newi->nh_parent = old;
979 oldi->nh_parent = new;
980
981 old->protocol = new->protocol;
982 old->nh_flags = new->nh_flags;
983
984 rcu_assign_pointer(old->nh_info, newi);
985 rcu_assign_pointer(new->nh_info, oldi);
986
987 return 0;
988}
989
990static void __nexthop_replace_notify(struct net *net, struct nexthop *nh,
991 struct nl_info *info)
992{
993 struct fib6_info *f6i;
994
995 if (!list_empty(&nh->fi_list)) {
996 struct fib_info *fi;
997
998 /* expectation is a few fib_info per nexthop and then
999 * a lot of routes per fib_info. So mark the fib_info
1000 * and then walk the fib tables once
1001 */
1002 list_for_each_entry(fi, &nh->fi_list, nh_list)
1003 fi->nh_updated = true;
1004
1005 fib_info_notify_update(net, info);
1006
1007 list_for_each_entry(fi, &nh->fi_list, nh_list)
1008 fi->nh_updated = false;
1009 }
1010
1011 list_for_each_entry(f6i, &nh->f6i_list, nh_list)
1012 ipv6_stub->fib6_rt_update(net, f6i, info);
1013}
1014
1015/* send RTM_NEWROUTE with REPLACE flag set for all FIB entries
1016 * linked to this nexthop and for all groups that the nexthop
1017 * is a member of
1018 */
1019static void nexthop_replace_notify(struct net *net, struct nexthop *nh,
1020 struct nl_info *info)
1021{
1022 struct nh_grp_entry *nhge;
1023
1024 __nexthop_replace_notify(net, nh, info);
1025
1026 list_for_each_entry(nhge, &nh->grp_list, nh_list)
1027 __nexthop_replace_notify(net, nhge->nh_parent, info);
1028}
1029
1030static int replace_nexthop(struct net *net, struct nexthop *old,
1031 struct nexthop *new, struct netlink_ext_ack *extack)
1032{
1033 bool new_is_reject = false;
1034 struct nh_grp_entry *nhge;
1035 int err;
1036
1037 /* check that existing FIB entries are ok with the
1038 * new nexthop definition
1039 */
1040 err = fib_check_nh_list(old, new, extack);
1041 if (err)
1042 return err;
1043
1044 err = fib6_check_nh_list(old, new, extack);
1045 if (err)
1046 return err;
1047
1048 if (!new->is_group) {
1049 struct nh_info *nhi = rtnl_dereference(new->nh_info);
1050
1051 new_is_reject = nhi->reject_nh;
1052 }
1053
1054 list_for_each_entry(nhge, &old->grp_list, nh_list) {
1055 /* if new nexthop is a blackhole, any groups using this
1056 * nexthop cannot have more than 1 path
1057 */
1058 if (new_is_reject &&
1059 nexthop_num_path(nhge->nh_parent) > 1) {
1060 NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path");
1061 return -EINVAL;
1062 }
1063
1064 err = fib_check_nh_list(nhge->nh_parent, new, extack);
1065 if (err)
1066 return err;
1067
1068 err = fib6_check_nh_list(nhge->nh_parent, new, extack);
1069 if (err)
1070 return err;
1071 }
1072
1073 if (old->is_group)
1074 err = replace_nexthop_grp(net, old, new, extack);
1075 else
1076 err = replace_nexthop_single(net, old, new, extack);
1077
1078 if (!err) {
1079 nh_rt_cache_flush(net, old);
1080
1081 __remove_nexthop(net, new, NULL);
1082 nexthop_put(new);
1083 }
1084
1085 return err;
1086}
1087
1088/* called with rtnl_lock held */
1089static int insert_nexthop(struct net *net, struct nexthop *new_nh,
1090 struct nh_config *cfg, struct netlink_ext_ack *extack)
1091{
1092 struct rb_node **pp, *parent = NULL, *next;
1093 struct rb_root *root = &net->nexthop.rb_root;
1094 bool replace = !!(cfg->nlflags & NLM_F_REPLACE);
1095 bool create = !!(cfg->nlflags & NLM_F_CREATE);
1096 u32 new_id = new_nh->id;
1097 int replace_notify = 0;
1098 int rc = -EEXIST;
1099
1100 pp = &root->rb_node;
1101 while (1) {
1102 struct nexthop *nh;
1103
1104 next = rtnl_dereference(*pp);
1105 if (!next)
1106 break;
1107
1108 parent = next;
1109
1110 nh = rb_entry(parent, struct nexthop, rb_node);
1111 if (new_id < nh->id) {
1112 pp = &next->rb_left;
1113 } else if (new_id > nh->id) {
1114 pp = &next->rb_right;
1115 } else if (replace) {
1116 rc = replace_nexthop(net, nh, new_nh, extack);
1117 if (!rc) {
1118 new_nh = nh; /* send notification with old nh */
1119 replace_notify = 1;
1120 }
1121 goto out;
1122 } else {
1123 /* id already exists and not a replace */
1124 goto out;
1125 }
1126 }
1127
1128 if (replace && !create) {
1129 NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists");
1130 rc = -ENOENT;
1131 goto out;
1132 }
1133
1134 rb_link_node_rcu(&new_nh->rb_node, parent, pp);
1135 rb_insert_color(&new_nh->rb_node, root);
1136 rc = 0;
1137out:
1138 if (!rc) {
1139 nh_base_seq_inc(net);
1140 nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo);
1141 if (replace_notify && net->ipv4.sysctl_nexthop_compat_mode)
1142 nexthop_replace_notify(net, new_nh, &cfg->nlinfo);
1143 }
1144
1145 return rc;
1146}
1147
1148/* rtnl */
1149/* remove all nexthops tied to a device being deleted */
1150static void nexthop_flush_dev(struct net_device *dev)
1151{
1152 unsigned int hash = nh_dev_hashfn(dev->ifindex);
1153 struct net *net = dev_net(dev);
1154 struct hlist_head *head = &net->nexthop.devhash[hash];
1155 struct hlist_node *n;
1156 struct nh_info *nhi;
1157
1158 hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
1159 if (nhi->fib_nhc.nhc_dev != dev)
1160 continue;
1161
1162 remove_nexthop(net, nhi->nh_parent, NULL);
1163 }
1164}
1165
1166/* rtnl; called when net namespace is deleted */
1167static void flush_all_nexthops(struct net *net)
1168{
1169 struct rb_root *root = &net->nexthop.rb_root;
1170 struct rb_node *node;
1171 struct nexthop *nh;
1172
1173 while ((node = rb_first(root))) {
1174 nh = rb_entry(node, struct nexthop, rb_node);
1175 remove_nexthop(net, nh, NULL);
1176 cond_resched();
1177 }
1178}
1179
1180static struct nexthop *nexthop_create_group(struct net *net,
1181 struct nh_config *cfg)
1182{
1183 struct nlattr *grps_attr = cfg->nh_grp;
1184 struct nexthop_grp *entry = nla_data(grps_attr);
1185 u16 num_nh = nla_len(grps_attr) / sizeof(*entry);
1186 struct nh_group *nhg;
1187 struct nexthop *nh;
1188 int i;
1189
1190 if (WARN_ON(!num_nh))
1191 return ERR_PTR(-EINVAL);
1192
1193 nh = nexthop_alloc();
1194 if (!nh)
1195 return ERR_PTR(-ENOMEM);
1196
1197 nh->is_group = 1;
1198
1199 nhg = nexthop_grp_alloc(num_nh);
1200 if (!nhg) {
1201 kfree(nh);
1202 return ERR_PTR(-ENOMEM);
1203 }
1204
1205 /* spare group used for removals */
1206 nhg->spare = nexthop_grp_alloc(num_nh);
1207 if (!nhg->spare) {
1208 kfree(nhg);
1209 kfree(nh);
1210 return ERR_PTR(-ENOMEM);
1211 }
1212 nhg->spare->spare = nhg;
1213
1214 for (i = 0; i < nhg->num_nh; ++i) {
1215 struct nexthop *nhe;
1216 struct nh_info *nhi;
1217
1218 nhe = nexthop_find_by_id(net, entry[i].id);
1219 if (!nexthop_get(nhe))
1220 goto out_no_nh;
1221
1222 nhi = rtnl_dereference(nhe->nh_info);
1223 if (nhi->family == AF_INET)
1224 nhg->has_v4 = true;
1225
1226 nhg->nh_entries[i].nh = nhe;
1227 nhg->nh_entries[i].weight = entry[i].weight + 1;
1228 list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list);
1229 nhg->nh_entries[i].nh_parent = nh;
1230 }
1231
1232 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) {
1233 nhg->mpath = 1;
1234 nh_group_rebalance(nhg);
1235 }
1236
1237 if (cfg->nh_fdb)
1238 nhg->fdb_nh = 1;
1239
1240 rcu_assign_pointer(nh->nh_grp, nhg);
1241
1242 return nh;
1243
1244out_no_nh:
1245 for (; i >= 0; --i)
1246 nexthop_put(nhg->nh_entries[i].nh);
1247
1248 kfree(nhg->spare);
1249 kfree(nhg);
1250 kfree(nh);
1251
1252 return ERR_PTR(-ENOENT);
1253}
1254
1255static int nh_create_ipv4(struct net *net, struct nexthop *nh,
1256 struct nh_info *nhi, struct nh_config *cfg,
1257 struct netlink_ext_ack *extack)
1258{
1259 struct fib_nh *fib_nh = &nhi->fib_nh;
1260 struct fib_config fib_cfg = {
1261 .fc_oif = cfg->nh_ifindex,
1262 .fc_gw4 = cfg->gw.ipv4,
1263 .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0,
1264 .fc_flags = cfg->nh_flags,
1265 .fc_encap = cfg->nh_encap,
1266 .fc_encap_type = cfg->nh_encap_type,
1267 };
1268 u32 tb_id = (cfg->dev ? l3mdev_fib_table(cfg->dev) : RT_TABLE_MAIN);
1269 int err;
1270
1271 err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack);
1272 if (err) {
1273 fib_nh_release(net, fib_nh);
1274 goto out;
1275 }
1276
1277 if (nhi->fdb_nh)
1278 goto out;
1279
1280 /* sets nh_dev if successful */
1281 err = fib_check_nh(net, fib_nh, tb_id, 0, extack);
1282 if (!err) {
1283 nh->nh_flags = fib_nh->fib_nh_flags;
1284 fib_info_update_nhc_saddr(net, &fib_nh->nh_common,
1285 fib_nh->fib_nh_scope);
1286 } else {
1287 fib_nh_release(net, fib_nh);
1288 }
1289out:
1290 return err;
1291}
1292
1293static int nh_create_ipv6(struct net *net, struct nexthop *nh,
1294 struct nh_info *nhi, struct nh_config *cfg,
1295 struct netlink_ext_ack *extack)
1296{
1297 struct fib6_nh *fib6_nh = &nhi->fib6_nh;
1298 struct fib6_config fib6_cfg = {
1299 .fc_table = l3mdev_fib_table(cfg->dev),
1300 .fc_ifindex = cfg->nh_ifindex,
1301 .fc_gateway = cfg->gw.ipv6,
1302 .fc_flags = cfg->nh_flags,
1303 .fc_encap = cfg->nh_encap,
1304 .fc_encap_type = cfg->nh_encap_type,
1305 .fc_is_fdb = cfg->nh_fdb,
1306 };
1307 int err;
1308
1309 if (!ipv6_addr_any(&cfg->gw.ipv6))
1310 fib6_cfg.fc_flags |= RTF_GATEWAY;
1311
1312 /* sets nh_dev if successful */
1313 err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL,
1314 extack);
1315 if (err)
1316 ipv6_stub->fib6_nh_release(fib6_nh);
1317 else
1318 nh->nh_flags = fib6_nh->fib_nh_flags;
1319
1320 return err;
1321}
1322
1323static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg,
1324 struct netlink_ext_ack *extack)
1325{
1326 struct nh_info *nhi;
1327 struct nexthop *nh;
1328 int err = 0;
1329
1330 nh = nexthop_alloc();
1331 if (!nh)
1332 return ERR_PTR(-ENOMEM);
1333
1334 nhi = kzalloc(sizeof(*nhi), GFP_KERNEL);
1335 if (!nhi) {
1336 kfree(nh);
1337 return ERR_PTR(-ENOMEM);
1338 }
1339
1340 nh->nh_flags = cfg->nh_flags;
1341 nh->net = net;
1342
1343 nhi->nh_parent = nh;
1344 nhi->family = cfg->nh_family;
1345 nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK;
1346
1347 if (cfg->nh_fdb)
1348 nhi->fdb_nh = 1;
1349
1350 if (cfg->nh_blackhole) {
1351 nhi->reject_nh = 1;
1352 cfg->nh_ifindex = net->loopback_dev->ifindex;
1353 }
1354
1355 switch (cfg->nh_family) {
1356 case AF_INET:
1357 err = nh_create_ipv4(net, nh, nhi, cfg, extack);
1358 break;
1359 case AF_INET6:
1360 err = nh_create_ipv6(net, nh, nhi, cfg, extack);
1361 break;
1362 }
1363
1364 if (err) {
1365 kfree(nhi);
1366 kfree(nh);
1367 return ERR_PTR(err);
1368 }
1369
1370 /* add the entry to the device based hash */
1371 if (!nhi->fdb_nh)
1372 nexthop_devhash_add(net, nhi);
1373
1374 rcu_assign_pointer(nh->nh_info, nhi);
1375
1376 return nh;
1377}
1378
1379/* called with rtnl lock held */
1380static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg,
1381 struct netlink_ext_ack *extack)
1382{
1383 struct nexthop *nh;
1384 int err;
1385
1386 if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) {
1387 NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
1388 return ERR_PTR(-EINVAL);
1389 }
1390
1391 if (!cfg->nh_id) {
1392 cfg->nh_id = nh_find_unused_id(net);
1393 if (!cfg->nh_id) {
1394 NL_SET_ERR_MSG(extack, "No unused id");
1395 return ERR_PTR(-EINVAL);
1396 }
1397 }
1398
1399 if (cfg->nh_grp)
1400 nh = nexthop_create_group(net, cfg);
1401 else
1402 nh = nexthop_create(net, cfg, extack);
1403
1404 if (IS_ERR(nh))
1405 return nh;
1406
1407 refcount_set(&nh->refcnt, 1);
1408 nh->id = cfg->nh_id;
1409 nh->protocol = cfg->nh_protocol;
1410 nh->net = net;
1411
1412 err = insert_nexthop(net, nh, cfg, extack);
1413 if (err) {
1414 __remove_nexthop(net, nh, NULL);
1415 nexthop_put(nh);
1416 nh = ERR_PTR(err);
1417 }
1418
1419 return nh;
1420}
1421
1422static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
1423 struct nlmsghdr *nlh, struct nh_config *cfg,
1424 struct netlink_ext_ack *extack)
1425{
1426 struct nhmsg *nhm = nlmsg_data(nlh);
1427 struct nlattr *tb[NHA_MAX + 1];
1428 int err;
1429
1430 err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1431 extack);
1432 if (err < 0)
1433 return err;
1434
1435 err = -EINVAL;
1436 if (nhm->resvd || nhm->nh_scope) {
1437 NL_SET_ERR_MSG(extack, "Invalid values in ancillary header");
1438 goto out;
1439 }
1440 if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) {
1441 NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header");
1442 goto out;
1443 }
1444
1445 switch (nhm->nh_family) {
1446 case AF_INET:
1447 case AF_INET6:
1448 break;
1449 case AF_UNSPEC:
1450 if (tb[NHA_GROUP])
1451 break;
1452 fallthrough;
1453 default:
1454 NL_SET_ERR_MSG(extack, "Invalid address family");
1455 goto out;
1456 }
1457
1458 if (tb[NHA_GROUPS] || tb[NHA_MASTER]) {
1459 NL_SET_ERR_MSG(extack, "Invalid attributes in request");
1460 goto out;
1461 }
1462
1463 memset(cfg, 0, sizeof(*cfg));
1464 cfg->nlflags = nlh->nlmsg_flags;
1465 cfg->nlinfo.portid = NETLINK_CB(skb).portid;
1466 cfg->nlinfo.nlh = nlh;
1467 cfg->nlinfo.nl_net = net;
1468
1469 cfg->nh_family = nhm->nh_family;
1470 cfg->nh_protocol = nhm->nh_protocol;
1471 cfg->nh_flags = nhm->nh_flags;
1472
1473 if (tb[NHA_ID])
1474 cfg->nh_id = nla_get_u32(tb[NHA_ID]);
1475
1476 if (tb[NHA_FDB]) {
1477 if (tb[NHA_OIF] || tb[NHA_BLACKHOLE] ||
1478 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) {
1479 NL_SET_ERR_MSG(extack, "Fdb attribute can not be used with encap, oif or blackhole");
1480 goto out;
1481 }
1482 if (nhm->nh_flags) {
1483 NL_SET_ERR_MSG(extack, "Unsupported nexthop flags in ancillary header");
1484 goto out;
1485 }
1486 cfg->nh_fdb = nla_get_flag(tb[NHA_FDB]);
1487 }
1488
1489 if (tb[NHA_GROUP]) {
1490 if (nhm->nh_family != AF_UNSPEC) {
1491 NL_SET_ERR_MSG(extack, "Invalid family for group");
1492 goto out;
1493 }
1494 cfg->nh_grp = tb[NHA_GROUP];
1495
1496 cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH;
1497 if (tb[NHA_GROUP_TYPE])
1498 cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]);
1499
1500 if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) {
1501 NL_SET_ERR_MSG(extack, "Invalid group type");
1502 goto out;
1503 }
1504 err = nh_check_attr_group(net, tb, extack);
1505
1506 /* no other attributes should be set */
1507 goto out;
1508 }
1509
1510 if (tb[NHA_BLACKHOLE]) {
1511 if (tb[NHA_GATEWAY] || tb[NHA_OIF] ||
1512 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE] || tb[NHA_FDB]) {
1513 NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway, oif, encap or fdb");
1514 goto out;
1515 }
1516
1517 cfg->nh_blackhole = 1;
1518 err = 0;
1519 goto out;
1520 }
1521
1522 if (!cfg->nh_fdb && !tb[NHA_OIF]) {
1523 NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole and non-fdb nexthops");
1524 goto out;
1525 }
1526
1527 if (!cfg->nh_fdb && tb[NHA_OIF]) {
1528 cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
1529 if (cfg->nh_ifindex)
1530 cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
1531
1532 if (!cfg->dev) {
1533 NL_SET_ERR_MSG(extack, "Invalid device index");
1534 goto out;
1535 } else if (!(cfg->dev->flags & IFF_UP)) {
1536 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
1537 err = -ENETDOWN;
1538 goto out;
1539 } else if (!netif_carrier_ok(cfg->dev)) {
1540 NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");
1541 err = -ENETDOWN;
1542 goto out;
1543 }
1544 }
1545
1546 err = -EINVAL;
1547 if (tb[NHA_GATEWAY]) {
1548 struct nlattr *gwa = tb[NHA_GATEWAY];
1549
1550 switch (cfg->nh_family) {
1551 case AF_INET:
1552 if (nla_len(gwa) != sizeof(u32)) {
1553 NL_SET_ERR_MSG(extack, "Invalid gateway");
1554 goto out;
1555 }
1556 cfg->gw.ipv4 = nla_get_be32(gwa);
1557 break;
1558 case AF_INET6:
1559 if (nla_len(gwa) != sizeof(struct in6_addr)) {
1560 NL_SET_ERR_MSG(extack, "Invalid gateway");
1561 goto out;
1562 }
1563 cfg->gw.ipv6 = nla_get_in6_addr(gwa);
1564 break;
1565 default:
1566 NL_SET_ERR_MSG(extack,
1567 "Unknown address family for gateway");
1568 goto out;
1569 }
1570 } else {
1571 /* device only nexthop (no gateway) */
1572 if (cfg->nh_flags & RTNH_F_ONLINK) {
1573 NL_SET_ERR_MSG(extack,
1574 "ONLINK flag can not be set for nexthop without a gateway");
1575 goto out;
1576 }
1577 }
1578
1579 if (tb[NHA_ENCAP]) {
1580 cfg->nh_encap = tb[NHA_ENCAP];
1581
1582 if (!tb[NHA_ENCAP_TYPE]) {
1583 NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing");
1584 goto out;
1585 }
1586
1587 cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]);
1588 err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack);
1589 if (err < 0)
1590 goto out;
1591
1592 } else if (tb[NHA_ENCAP_TYPE]) {
1593 NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing");
1594 goto out;
1595 }
1596
1597
1598 err = 0;
1599out:
1600 return err;
1601}
1602
1603/* rtnl */
1604static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
1605 struct netlink_ext_ack *extack)
1606{
1607 struct net *net = sock_net(skb->sk);
1608 struct nh_config cfg;
1609 struct nexthop *nh;
1610 int err;
1611
1612 err = rtm_to_nh_config(net, skb, nlh, &cfg, extack);
1613 if (!err) {
1614 nh = nexthop_add(net, &cfg, extack);
1615 if (IS_ERR(nh))
1616 err = PTR_ERR(nh);
1617 }
1618
1619 return err;
1620}
1621
1622static int nh_valid_get_del_req(struct nlmsghdr *nlh, u32 *id,
1623 struct netlink_ext_ack *extack)
1624{
1625 struct nhmsg *nhm = nlmsg_data(nlh);
1626 struct nlattr *tb[NHA_MAX + 1];
1627 int err, i;
1628
1629 err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1630 extack);
1631 if (err < 0)
1632 return err;
1633
1634 err = -EINVAL;
1635 for (i = 0; i < __NHA_MAX; ++i) {
1636 if (!tb[i])
1637 continue;
1638
1639 switch (i) {
1640 case NHA_ID:
1641 break;
1642 default:
1643 NL_SET_ERR_MSG_ATTR(extack, tb[i],
1644 "Unexpected attribute in request");
1645 goto out;
1646 }
1647 }
1648 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
1649 NL_SET_ERR_MSG(extack, "Invalid values in header");
1650 goto out;
1651 }
1652
1653 if (!tb[NHA_ID]) {
1654 NL_SET_ERR_MSG(extack, "Nexthop id is missing");
1655 goto out;
1656 }
1657
1658 *id = nla_get_u32(tb[NHA_ID]);
1659 if (!(*id))
1660 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
1661 else
1662 err = 0;
1663out:
1664 return err;
1665}
1666
1667/* rtnl */
1668static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
1669 struct netlink_ext_ack *extack)
1670{
1671 struct net *net = sock_net(skb->sk);
1672 struct nl_info nlinfo = {
1673 .nlh = nlh,
1674 .nl_net = net,
1675 .portid = NETLINK_CB(skb).portid,
1676 };
1677 struct nexthop *nh;
1678 int err;
1679 u32 id;
1680
1681 err = nh_valid_get_del_req(nlh, &id, extack);
1682 if (err)
1683 return err;
1684
1685 nh = nexthop_find_by_id(net, id);
1686 if (!nh)
1687 return -ENOENT;
1688
1689 remove_nexthop(net, nh, &nlinfo);
1690
1691 return 0;
1692}
1693
1694/* rtnl */
1695static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh,
1696 struct netlink_ext_ack *extack)
1697{
1698 struct net *net = sock_net(in_skb->sk);
1699 struct sk_buff *skb = NULL;
1700 struct nexthop *nh;
1701 int err;
1702 u32 id;
1703
1704 err = nh_valid_get_del_req(nlh, &id, extack);
1705 if (err)
1706 return err;
1707
1708 err = -ENOBUFS;
1709 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1710 if (!skb)
1711 goto out;
1712
1713 err = -ENOENT;
1714 nh = nexthop_find_by_id(net, id);
1715 if (!nh)
1716 goto errout_free;
1717
1718 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid,
1719 nlh->nlmsg_seq, 0);
1720 if (err < 0) {
1721 WARN_ON(err == -EMSGSIZE);
1722 goto errout_free;
1723 }
1724
1725 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
1726out:
1727 return err;
1728errout_free:
1729 kfree_skb(skb);
1730 goto out;
1731}
1732
1733static bool nh_dump_filtered(struct nexthop *nh, int dev_idx, int master_idx,
1734 bool group_filter, u8 family)
1735{
1736 const struct net_device *dev;
1737 const struct nh_info *nhi;
1738
1739 if (group_filter && !nh->is_group)
1740 return true;
1741
1742 if (!dev_idx && !master_idx && !family)
1743 return false;
1744
1745 if (nh->is_group)
1746 return true;
1747
1748 nhi = rtnl_dereference(nh->nh_info);
1749 if (family && nhi->family != family)
1750 return true;
1751
1752 dev = nhi->fib_nhc.nhc_dev;
1753 if (dev_idx && (!dev || dev->ifindex != dev_idx))
1754 return true;
1755
1756 if (master_idx) {
1757 struct net_device *master;
1758
1759 if (!dev)
1760 return true;
1761
1762 master = netdev_master_upper_dev_get((struct net_device *)dev);
1763 if (!master || master->ifindex != master_idx)
1764 return true;
1765 }
1766
1767 return false;
1768}
1769
1770static int nh_valid_dump_req(const struct nlmsghdr *nlh, int *dev_idx,
1771 int *master_idx, bool *group_filter,
1772 bool *fdb_filter, struct netlink_callback *cb)
1773{
1774 struct netlink_ext_ack *extack = cb->extack;
1775 struct nlattr *tb[NHA_MAX + 1];
1776 struct nhmsg *nhm;
1777 int err, i;
1778 u32 idx;
1779
1780 err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1781 NULL);
1782 if (err < 0)
1783 return err;
1784
1785 for (i = 0; i <= NHA_MAX; ++i) {
1786 if (!tb[i])
1787 continue;
1788
1789 switch (i) {
1790 case NHA_OIF:
1791 idx = nla_get_u32(tb[i]);
1792 if (idx > INT_MAX) {
1793 NL_SET_ERR_MSG(extack, "Invalid device index");
1794 return -EINVAL;
1795 }
1796 *dev_idx = idx;
1797 break;
1798 case NHA_MASTER:
1799 idx = nla_get_u32(tb[i]);
1800 if (idx > INT_MAX) {
1801 NL_SET_ERR_MSG(extack, "Invalid master device index");
1802 return -EINVAL;
1803 }
1804 *master_idx = idx;
1805 break;
1806 case NHA_GROUPS:
1807 *group_filter = true;
1808 break;
1809 case NHA_FDB:
1810 *fdb_filter = true;
1811 break;
1812 default:
1813 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
1814 return -EINVAL;
1815 }
1816 }
1817
1818 nhm = nlmsg_data(nlh);
1819 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
1820 NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request");
1821 return -EINVAL;
1822 }
1823
1824 return 0;
1825}
1826
1827/* rtnl */
1828static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
1829{
1830 bool group_filter = false, fdb_filter = false;
1831 struct nhmsg *nhm = nlmsg_data(cb->nlh);
1832 int dev_filter_idx = 0, master_idx = 0;
1833 struct net *net = sock_net(skb->sk);
1834 struct rb_root *root = &net->nexthop.rb_root;
1835 struct rb_node *node;
1836 int idx = 0, s_idx;
1837 int err;
1838
1839 err = nh_valid_dump_req(cb->nlh, &dev_filter_idx, &master_idx,
1840 &group_filter, &fdb_filter, cb);
1841 if (err < 0)
1842 return err;
1843
1844 s_idx = cb->args[0];
1845 for (node = rb_first(root); node; node = rb_next(node)) {
1846 struct nexthop *nh;
1847
1848 if (idx < s_idx)
1849 goto cont;
1850
1851 nh = rb_entry(node, struct nexthop, rb_node);
1852 if (nh_dump_filtered(nh, dev_filter_idx, master_idx,
1853 group_filter, nhm->nh_family))
1854 goto cont;
1855
1856 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP,
1857 NETLINK_CB(cb->skb).portid,
1858 cb->nlh->nlmsg_seq, NLM_F_MULTI);
1859 if (err < 0) {
1860 if (likely(skb->len))
1861 goto out;
1862
1863 goto out_err;
1864 }
1865cont:
1866 idx++;
1867 }
1868
1869out:
1870 err = skb->len;
1871out_err:
1872 cb->args[0] = idx;
1873 cb->seq = net->nexthop.seq;
1874 nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1875
1876 return err;
1877}
1878
1879static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu)
1880{
1881 unsigned int hash = nh_dev_hashfn(dev->ifindex);
1882 struct net *net = dev_net(dev);
1883 struct hlist_head *head = &net->nexthop.devhash[hash];
1884 struct hlist_node *n;
1885 struct nh_info *nhi;
1886
1887 hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
1888 if (nhi->fib_nhc.nhc_dev == dev) {
1889 if (nhi->family == AF_INET)
1890 fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu,
1891 orig_mtu);
1892 }
1893 }
1894}
1895
1896/* rtnl */
1897static int nh_netdev_event(struct notifier_block *this,
1898 unsigned long event, void *ptr)
1899{
1900 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1901 struct netdev_notifier_info_ext *info_ext;
1902
1903 switch (event) {
1904 case NETDEV_DOWN:
1905 case NETDEV_UNREGISTER:
1906 nexthop_flush_dev(dev);
1907 break;
1908 case NETDEV_CHANGE:
1909 if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP)))
1910 nexthop_flush_dev(dev);
1911 break;
1912 case NETDEV_CHANGEMTU:
1913 info_ext = ptr;
1914 nexthop_sync_mtu(dev, info_ext->ext.mtu);
1915 rt_cache_flush(dev_net(dev));
1916 break;
1917 }
1918 return NOTIFY_DONE;
1919}
1920
1921static struct notifier_block nh_netdev_notifier = {
1922 .notifier_call = nh_netdev_event,
1923};
1924
1925int register_nexthop_notifier(struct net *net, struct notifier_block *nb)
1926{
1927 return atomic_notifier_chain_register(&net->nexthop.notifier_chain, nb);
1928}
1929EXPORT_SYMBOL(register_nexthop_notifier);
1930
1931int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb)
1932{
1933 return atomic_notifier_chain_unregister(&net->nexthop.notifier_chain,
1934 nb);
1935}
1936EXPORT_SYMBOL(unregister_nexthop_notifier);
1937
1938static void __net_exit nexthop_net_exit(struct net *net)
1939{
1940 rtnl_lock();
1941 flush_all_nexthops(net);
1942 rtnl_unlock();
1943 kfree(net->nexthop.devhash);
1944}
1945
1946static int __net_init nexthop_net_init(struct net *net)
1947{
1948 size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE;
1949
1950 net->nexthop.rb_root = RB_ROOT;
1951 net->nexthop.devhash = kzalloc(sz, GFP_KERNEL);
1952 if (!net->nexthop.devhash)
1953 return -ENOMEM;
1954 ATOMIC_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain);
1955
1956 return 0;
1957}
1958
1959static struct pernet_operations nexthop_net_ops = {
1960 .init = nexthop_net_init,
1961 .exit = nexthop_net_exit,
1962};
1963
1964static int __init nexthop_init(void)
1965{
1966 register_pernet_subsys(&nexthop_net_ops);
1967
1968 register_netdevice_notifier(&nh_netdev_notifier);
1969
1970 rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
1971 rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0);
1972 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop,
1973 rtm_dump_nexthop, 0);
1974
1975 rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
1976 rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
1977
1978 rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
1979 rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
1980
1981 return 0;
1982}
1983subsys_initcall(nexthop_init);
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 <linux/vmalloc.h>
12#include <net/arp.h>
13#include <net/ipv6_stubs.h>
14#include <net/lwtunnel.h>
15#include <net/ndisc.h>
16#include <net/nexthop.h>
17#include <net/route.h>
18#include <net/sock.h>
19
20#define NH_RES_DEFAULT_IDLE_TIMER (120 * HZ)
21#define NH_RES_DEFAULT_UNBALANCED_TIMER 0 /* No forced rebalancing. */
22
23static void remove_nexthop(struct net *net, struct nexthop *nh,
24 struct nl_info *nlinfo);
25
26#define NH_DEV_HASHBITS 8
27#define NH_DEV_HASHSIZE (1U << NH_DEV_HASHBITS)
28
29static const struct nla_policy rtm_nh_policy_new[] = {
30 [NHA_ID] = { .type = NLA_U32 },
31 [NHA_GROUP] = { .type = NLA_BINARY },
32 [NHA_GROUP_TYPE] = { .type = NLA_U16 },
33 [NHA_BLACKHOLE] = { .type = NLA_FLAG },
34 [NHA_OIF] = { .type = NLA_U32 },
35 [NHA_GATEWAY] = { .type = NLA_BINARY },
36 [NHA_ENCAP_TYPE] = { .type = NLA_U16 },
37 [NHA_ENCAP] = { .type = NLA_NESTED },
38 [NHA_FDB] = { .type = NLA_FLAG },
39 [NHA_RES_GROUP] = { .type = NLA_NESTED },
40};
41
42static const struct nla_policy rtm_nh_policy_get[] = {
43 [NHA_ID] = { .type = NLA_U32 },
44};
45
46static const struct nla_policy rtm_nh_policy_dump[] = {
47 [NHA_OIF] = { .type = NLA_U32 },
48 [NHA_GROUPS] = { .type = NLA_FLAG },
49 [NHA_MASTER] = { .type = NLA_U32 },
50 [NHA_FDB] = { .type = NLA_FLAG },
51};
52
53static const struct nla_policy rtm_nh_res_policy_new[] = {
54 [NHA_RES_GROUP_BUCKETS] = { .type = NLA_U16 },
55 [NHA_RES_GROUP_IDLE_TIMER] = { .type = NLA_U32 },
56 [NHA_RES_GROUP_UNBALANCED_TIMER] = { .type = NLA_U32 },
57};
58
59static const struct nla_policy rtm_nh_policy_dump_bucket[] = {
60 [NHA_ID] = { .type = NLA_U32 },
61 [NHA_OIF] = { .type = NLA_U32 },
62 [NHA_MASTER] = { .type = NLA_U32 },
63 [NHA_RES_BUCKET] = { .type = NLA_NESTED },
64};
65
66static const struct nla_policy rtm_nh_res_bucket_policy_dump[] = {
67 [NHA_RES_BUCKET_NH_ID] = { .type = NLA_U32 },
68};
69
70static const struct nla_policy rtm_nh_policy_get_bucket[] = {
71 [NHA_ID] = { .type = NLA_U32 },
72 [NHA_RES_BUCKET] = { .type = NLA_NESTED },
73};
74
75static const struct nla_policy rtm_nh_res_bucket_policy_get[] = {
76 [NHA_RES_BUCKET_INDEX] = { .type = NLA_U16 },
77};
78
79static bool nexthop_notifiers_is_empty(struct net *net)
80{
81 return !net->nexthop.notifier_chain.head;
82}
83
84static void
85__nh_notifier_single_info_init(struct nh_notifier_single_info *nh_info,
86 const struct nh_info *nhi)
87{
88 nh_info->dev = nhi->fib_nhc.nhc_dev;
89 nh_info->gw_family = nhi->fib_nhc.nhc_gw_family;
90 if (nh_info->gw_family == AF_INET)
91 nh_info->ipv4 = nhi->fib_nhc.nhc_gw.ipv4;
92 else if (nh_info->gw_family == AF_INET6)
93 nh_info->ipv6 = nhi->fib_nhc.nhc_gw.ipv6;
94
95 nh_info->is_reject = nhi->reject_nh;
96 nh_info->is_fdb = nhi->fdb_nh;
97 nh_info->has_encap = !!nhi->fib_nhc.nhc_lwtstate;
98}
99
100static int nh_notifier_single_info_init(struct nh_notifier_info *info,
101 const struct nexthop *nh)
102{
103 struct nh_info *nhi = rtnl_dereference(nh->nh_info);
104
105 info->type = NH_NOTIFIER_INFO_TYPE_SINGLE;
106 info->nh = kzalloc(sizeof(*info->nh), GFP_KERNEL);
107 if (!info->nh)
108 return -ENOMEM;
109
110 __nh_notifier_single_info_init(info->nh, nhi);
111
112 return 0;
113}
114
115static void nh_notifier_single_info_fini(struct nh_notifier_info *info)
116{
117 kfree(info->nh);
118}
119
120static int nh_notifier_mpath_info_init(struct nh_notifier_info *info,
121 struct nh_group *nhg)
122{
123 u16 num_nh = nhg->num_nh;
124 int i;
125
126 info->type = NH_NOTIFIER_INFO_TYPE_GRP;
127 info->nh_grp = kzalloc(struct_size(info->nh_grp, nh_entries, num_nh),
128 GFP_KERNEL);
129 if (!info->nh_grp)
130 return -ENOMEM;
131
132 info->nh_grp->num_nh = num_nh;
133 info->nh_grp->is_fdb = nhg->fdb_nh;
134
135 for (i = 0; i < num_nh; i++) {
136 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
137 struct nh_info *nhi;
138
139 nhi = rtnl_dereference(nhge->nh->nh_info);
140 info->nh_grp->nh_entries[i].id = nhge->nh->id;
141 info->nh_grp->nh_entries[i].weight = nhge->weight;
142 __nh_notifier_single_info_init(&info->nh_grp->nh_entries[i].nh,
143 nhi);
144 }
145
146 return 0;
147}
148
149static int nh_notifier_res_table_info_init(struct nh_notifier_info *info,
150 struct nh_group *nhg)
151{
152 struct nh_res_table *res_table = rtnl_dereference(nhg->res_table);
153 u16 num_nh_buckets = res_table->num_nh_buckets;
154 unsigned long size;
155 u16 i;
156
157 info->type = NH_NOTIFIER_INFO_TYPE_RES_TABLE;
158 size = struct_size(info->nh_res_table, nhs, num_nh_buckets);
159 info->nh_res_table = __vmalloc(size, GFP_KERNEL | __GFP_ZERO |
160 __GFP_NOWARN);
161 if (!info->nh_res_table)
162 return -ENOMEM;
163
164 info->nh_res_table->num_nh_buckets = num_nh_buckets;
165
166 for (i = 0; i < num_nh_buckets; i++) {
167 struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
168 struct nh_grp_entry *nhge;
169 struct nh_info *nhi;
170
171 nhge = rtnl_dereference(bucket->nh_entry);
172 nhi = rtnl_dereference(nhge->nh->nh_info);
173 __nh_notifier_single_info_init(&info->nh_res_table->nhs[i],
174 nhi);
175 }
176
177 return 0;
178}
179
180static int nh_notifier_grp_info_init(struct nh_notifier_info *info,
181 const struct nexthop *nh)
182{
183 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
184
185 if (nhg->hash_threshold)
186 return nh_notifier_mpath_info_init(info, nhg);
187 else if (nhg->resilient)
188 return nh_notifier_res_table_info_init(info, nhg);
189 return -EINVAL;
190}
191
192static void nh_notifier_grp_info_fini(struct nh_notifier_info *info,
193 const struct nexthop *nh)
194{
195 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
196
197 if (nhg->hash_threshold)
198 kfree(info->nh_grp);
199 else if (nhg->resilient)
200 vfree(info->nh_res_table);
201}
202
203static int nh_notifier_info_init(struct nh_notifier_info *info,
204 const struct nexthop *nh)
205{
206 info->id = nh->id;
207
208 if (nh->is_group)
209 return nh_notifier_grp_info_init(info, nh);
210 else
211 return nh_notifier_single_info_init(info, nh);
212}
213
214static void nh_notifier_info_fini(struct nh_notifier_info *info,
215 const struct nexthop *nh)
216{
217 if (nh->is_group)
218 nh_notifier_grp_info_fini(info, nh);
219 else
220 nh_notifier_single_info_fini(info);
221}
222
223static int call_nexthop_notifiers(struct net *net,
224 enum nexthop_event_type event_type,
225 struct nexthop *nh,
226 struct netlink_ext_ack *extack)
227{
228 struct nh_notifier_info info = {
229 .net = net,
230 .extack = extack,
231 };
232 int err;
233
234 ASSERT_RTNL();
235
236 if (nexthop_notifiers_is_empty(net))
237 return 0;
238
239 err = nh_notifier_info_init(&info, nh);
240 if (err) {
241 NL_SET_ERR_MSG(extack, "Failed to initialize nexthop notifier info");
242 return err;
243 }
244
245 err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
246 event_type, &info);
247 nh_notifier_info_fini(&info, nh);
248
249 return notifier_to_errno(err);
250}
251
252static int
253nh_notifier_res_bucket_idle_timer_get(const struct nh_notifier_info *info,
254 bool force, unsigned int *p_idle_timer_ms)
255{
256 struct nh_res_table *res_table;
257 struct nh_group *nhg;
258 struct nexthop *nh;
259 int err = 0;
260
261 /* When 'force' is false, nexthop bucket replacement is performed
262 * because the bucket was deemed to be idle. In this case, capable
263 * listeners can choose to perform an atomic replacement: The bucket is
264 * only replaced if it is inactive. However, if the idle timer interval
265 * is smaller than the interval in which a listener is querying
266 * buckets' activity from the device, then atomic replacement should
267 * not be tried. Pass the idle timer value to listeners, so that they
268 * could determine which type of replacement to perform.
269 */
270 if (force) {
271 *p_idle_timer_ms = 0;
272 return 0;
273 }
274
275 rcu_read_lock();
276
277 nh = nexthop_find_by_id(info->net, info->id);
278 if (!nh) {
279 err = -EINVAL;
280 goto out;
281 }
282
283 nhg = rcu_dereference(nh->nh_grp);
284 res_table = rcu_dereference(nhg->res_table);
285 *p_idle_timer_ms = jiffies_to_msecs(res_table->idle_timer);
286
287out:
288 rcu_read_unlock();
289
290 return err;
291}
292
293static int nh_notifier_res_bucket_info_init(struct nh_notifier_info *info,
294 u16 bucket_index, bool force,
295 struct nh_info *oldi,
296 struct nh_info *newi)
297{
298 unsigned int idle_timer_ms;
299 int err;
300
301 err = nh_notifier_res_bucket_idle_timer_get(info, force,
302 &idle_timer_ms);
303 if (err)
304 return err;
305
306 info->type = NH_NOTIFIER_INFO_TYPE_RES_BUCKET;
307 info->nh_res_bucket = kzalloc(sizeof(*info->nh_res_bucket),
308 GFP_KERNEL);
309 if (!info->nh_res_bucket)
310 return -ENOMEM;
311
312 info->nh_res_bucket->bucket_index = bucket_index;
313 info->nh_res_bucket->idle_timer_ms = idle_timer_ms;
314 info->nh_res_bucket->force = force;
315 __nh_notifier_single_info_init(&info->nh_res_bucket->old_nh, oldi);
316 __nh_notifier_single_info_init(&info->nh_res_bucket->new_nh, newi);
317 return 0;
318}
319
320static void nh_notifier_res_bucket_info_fini(struct nh_notifier_info *info)
321{
322 kfree(info->nh_res_bucket);
323}
324
325static int __call_nexthop_res_bucket_notifiers(struct net *net, u32 nhg_id,
326 u16 bucket_index, bool force,
327 struct nh_info *oldi,
328 struct nh_info *newi,
329 struct netlink_ext_ack *extack)
330{
331 struct nh_notifier_info info = {
332 .net = net,
333 .extack = extack,
334 .id = nhg_id,
335 };
336 int err;
337
338 if (nexthop_notifiers_is_empty(net))
339 return 0;
340
341 err = nh_notifier_res_bucket_info_init(&info, bucket_index, force,
342 oldi, newi);
343 if (err)
344 return err;
345
346 err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
347 NEXTHOP_EVENT_BUCKET_REPLACE, &info);
348 nh_notifier_res_bucket_info_fini(&info);
349
350 return notifier_to_errno(err);
351}
352
353/* There are three users of RES_TABLE, and NHs etc. referenced from there:
354 *
355 * 1) a collection of callbacks for NH maintenance. This operates under
356 * RTNL,
357 * 2) the delayed work that gradually balances the resilient table,
358 * 3) and nexthop_select_path(), operating under RCU.
359 *
360 * Both the delayed work and the RTNL block are writers, and need to
361 * maintain mutual exclusion. Since there are only two and well-known
362 * writers for each table, the RTNL code can make sure it has exclusive
363 * access thus:
364 *
365 * - Have the DW operate without locking;
366 * - synchronously cancel the DW;
367 * - do the writing;
368 * - if the write was not actually a delete, call upkeep, which schedules
369 * DW again if necessary.
370 *
371 * The functions that are always called from the RTNL context use
372 * rtnl_dereference(). The functions that can also be called from the DW do
373 * a raw dereference and rely on the above mutual exclusion scheme.
374 */
375#define nh_res_dereference(p) (rcu_dereference_raw(p))
376
377static int call_nexthop_res_bucket_notifiers(struct net *net, u32 nhg_id,
378 u16 bucket_index, bool force,
379 struct nexthop *old_nh,
380 struct nexthop *new_nh,
381 struct netlink_ext_ack *extack)
382{
383 struct nh_info *oldi = nh_res_dereference(old_nh->nh_info);
384 struct nh_info *newi = nh_res_dereference(new_nh->nh_info);
385
386 return __call_nexthop_res_bucket_notifiers(net, nhg_id, bucket_index,
387 force, oldi, newi, extack);
388}
389
390static int call_nexthop_res_table_notifiers(struct net *net, struct nexthop *nh,
391 struct netlink_ext_ack *extack)
392{
393 struct nh_notifier_info info = {
394 .net = net,
395 .extack = extack,
396 };
397 struct nh_group *nhg;
398 int err;
399
400 ASSERT_RTNL();
401
402 if (nexthop_notifiers_is_empty(net))
403 return 0;
404
405 /* At this point, the nexthop buckets are still not populated. Only
406 * emit a notification with the logical nexthops, so that a listener
407 * could potentially veto it in case of unsupported configuration.
408 */
409 nhg = rtnl_dereference(nh->nh_grp);
410 err = nh_notifier_mpath_info_init(&info, nhg);
411 if (err) {
412 NL_SET_ERR_MSG(extack, "Failed to initialize nexthop notifier info");
413 return err;
414 }
415
416 err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
417 NEXTHOP_EVENT_RES_TABLE_PRE_REPLACE,
418 &info);
419 kfree(info.nh_grp);
420
421 return notifier_to_errno(err);
422}
423
424static int call_nexthop_notifier(struct notifier_block *nb, struct net *net,
425 enum nexthop_event_type event_type,
426 struct nexthop *nh,
427 struct netlink_ext_ack *extack)
428{
429 struct nh_notifier_info info = {
430 .net = net,
431 .extack = extack,
432 };
433 int err;
434
435 err = nh_notifier_info_init(&info, nh);
436 if (err)
437 return err;
438
439 err = nb->notifier_call(nb, event_type, &info);
440 nh_notifier_info_fini(&info, nh);
441
442 return notifier_to_errno(err);
443}
444
445static unsigned int nh_dev_hashfn(unsigned int val)
446{
447 unsigned int mask = NH_DEV_HASHSIZE - 1;
448
449 return (val ^
450 (val >> NH_DEV_HASHBITS) ^
451 (val >> (NH_DEV_HASHBITS * 2))) & mask;
452}
453
454static void nexthop_devhash_add(struct net *net, struct nh_info *nhi)
455{
456 struct net_device *dev = nhi->fib_nhc.nhc_dev;
457 struct hlist_head *head;
458 unsigned int hash;
459
460 WARN_ON(!dev);
461
462 hash = nh_dev_hashfn(dev->ifindex);
463 head = &net->nexthop.devhash[hash];
464 hlist_add_head(&nhi->dev_hash, head);
465}
466
467static void nexthop_free_group(struct nexthop *nh)
468{
469 struct nh_group *nhg;
470 int i;
471
472 nhg = rcu_dereference_raw(nh->nh_grp);
473 for (i = 0; i < nhg->num_nh; ++i) {
474 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
475
476 WARN_ON(!list_empty(&nhge->nh_list));
477 nexthop_put(nhge->nh);
478 }
479
480 WARN_ON(nhg->spare == nhg);
481
482 if (nhg->resilient)
483 vfree(rcu_dereference_raw(nhg->res_table));
484
485 kfree(nhg->spare);
486 kfree(nhg);
487}
488
489static void nexthop_free_single(struct nexthop *nh)
490{
491 struct nh_info *nhi;
492
493 nhi = rcu_dereference_raw(nh->nh_info);
494 switch (nhi->family) {
495 case AF_INET:
496 fib_nh_release(nh->net, &nhi->fib_nh);
497 break;
498 case AF_INET6:
499 ipv6_stub->fib6_nh_release(&nhi->fib6_nh);
500 break;
501 }
502 kfree(nhi);
503}
504
505void nexthop_free_rcu(struct rcu_head *head)
506{
507 struct nexthop *nh = container_of(head, struct nexthop, rcu);
508
509 if (nh->is_group)
510 nexthop_free_group(nh);
511 else
512 nexthop_free_single(nh);
513
514 kfree(nh);
515}
516EXPORT_SYMBOL_GPL(nexthop_free_rcu);
517
518static struct nexthop *nexthop_alloc(void)
519{
520 struct nexthop *nh;
521
522 nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL);
523 if (nh) {
524 INIT_LIST_HEAD(&nh->fi_list);
525 INIT_LIST_HEAD(&nh->f6i_list);
526 INIT_LIST_HEAD(&nh->grp_list);
527 INIT_LIST_HEAD(&nh->fdb_list);
528 }
529 return nh;
530}
531
532static struct nh_group *nexthop_grp_alloc(u16 num_nh)
533{
534 struct nh_group *nhg;
535
536 nhg = kzalloc(struct_size(nhg, nh_entries, num_nh), GFP_KERNEL);
537 if (nhg)
538 nhg->num_nh = num_nh;
539
540 return nhg;
541}
542
543static void nh_res_table_upkeep_dw(struct work_struct *work);
544
545static struct nh_res_table *
546nexthop_res_table_alloc(struct net *net, u32 nhg_id, struct nh_config *cfg)
547{
548 const u16 num_nh_buckets = cfg->nh_grp_res_num_buckets;
549 struct nh_res_table *res_table;
550 unsigned long size;
551
552 size = struct_size(res_table, nh_buckets, num_nh_buckets);
553 res_table = __vmalloc(size, GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
554 if (!res_table)
555 return NULL;
556
557 res_table->net = net;
558 res_table->nhg_id = nhg_id;
559 INIT_DELAYED_WORK(&res_table->upkeep_dw, &nh_res_table_upkeep_dw);
560 INIT_LIST_HEAD(&res_table->uw_nh_entries);
561 res_table->idle_timer = cfg->nh_grp_res_idle_timer;
562 res_table->unbalanced_timer = cfg->nh_grp_res_unbalanced_timer;
563 res_table->num_nh_buckets = num_nh_buckets;
564 return res_table;
565}
566
567static void nh_base_seq_inc(struct net *net)
568{
569 while (++net->nexthop.seq == 0)
570 ;
571}
572
573/* no reference taken; rcu lock or rtnl must be held */
574struct nexthop *nexthop_find_by_id(struct net *net, u32 id)
575{
576 struct rb_node **pp, *parent = NULL, *next;
577
578 pp = &net->nexthop.rb_root.rb_node;
579 while (1) {
580 struct nexthop *nh;
581
582 next = rcu_dereference_raw(*pp);
583 if (!next)
584 break;
585 parent = next;
586
587 nh = rb_entry(parent, struct nexthop, rb_node);
588 if (id < nh->id)
589 pp = &next->rb_left;
590 else if (id > nh->id)
591 pp = &next->rb_right;
592 else
593 return nh;
594 }
595 return NULL;
596}
597EXPORT_SYMBOL_GPL(nexthop_find_by_id);
598
599/* used for auto id allocation; called with rtnl held */
600static u32 nh_find_unused_id(struct net *net)
601{
602 u32 id_start = net->nexthop.last_id_allocated;
603
604 while (1) {
605 net->nexthop.last_id_allocated++;
606 if (net->nexthop.last_id_allocated == id_start)
607 break;
608
609 if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated))
610 return net->nexthop.last_id_allocated;
611 }
612 return 0;
613}
614
615static void nh_res_time_set_deadline(unsigned long next_time,
616 unsigned long *deadline)
617{
618 if (time_before(next_time, *deadline))
619 *deadline = next_time;
620}
621
622static clock_t nh_res_table_unbalanced_time(struct nh_res_table *res_table)
623{
624 if (list_empty(&res_table->uw_nh_entries))
625 return 0;
626 return jiffies_delta_to_clock_t(jiffies - res_table->unbalanced_since);
627}
628
629static int nla_put_nh_group_res(struct sk_buff *skb, struct nh_group *nhg)
630{
631 struct nh_res_table *res_table = rtnl_dereference(nhg->res_table);
632 struct nlattr *nest;
633
634 nest = nla_nest_start(skb, NHA_RES_GROUP);
635 if (!nest)
636 return -EMSGSIZE;
637
638 if (nla_put_u16(skb, NHA_RES_GROUP_BUCKETS,
639 res_table->num_nh_buckets) ||
640 nla_put_u32(skb, NHA_RES_GROUP_IDLE_TIMER,
641 jiffies_to_clock_t(res_table->idle_timer)) ||
642 nla_put_u32(skb, NHA_RES_GROUP_UNBALANCED_TIMER,
643 jiffies_to_clock_t(res_table->unbalanced_timer)) ||
644 nla_put_u64_64bit(skb, NHA_RES_GROUP_UNBALANCED_TIME,
645 nh_res_table_unbalanced_time(res_table),
646 NHA_RES_GROUP_PAD))
647 goto nla_put_failure;
648
649 nla_nest_end(skb, nest);
650 return 0;
651
652nla_put_failure:
653 nla_nest_cancel(skb, nest);
654 return -EMSGSIZE;
655}
656
657static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg)
658{
659 struct nexthop_grp *p;
660 size_t len = nhg->num_nh * sizeof(*p);
661 struct nlattr *nla;
662 u16 group_type = 0;
663 int i;
664
665 if (nhg->hash_threshold)
666 group_type = NEXTHOP_GRP_TYPE_MPATH;
667 else if (nhg->resilient)
668 group_type = NEXTHOP_GRP_TYPE_RES;
669
670 if (nla_put_u16(skb, NHA_GROUP_TYPE, group_type))
671 goto nla_put_failure;
672
673 nla = nla_reserve(skb, NHA_GROUP, len);
674 if (!nla)
675 goto nla_put_failure;
676
677 p = nla_data(nla);
678 for (i = 0; i < nhg->num_nh; ++i) {
679 p->id = nhg->nh_entries[i].nh->id;
680 p->weight = nhg->nh_entries[i].weight - 1;
681 p += 1;
682 }
683
684 if (nhg->resilient && nla_put_nh_group_res(skb, nhg))
685 goto nla_put_failure;
686
687 return 0;
688
689nla_put_failure:
690 return -EMSGSIZE;
691}
692
693static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh,
694 int event, u32 portid, u32 seq, unsigned int nlflags)
695{
696 struct fib6_nh *fib6_nh;
697 struct fib_nh *fib_nh;
698 struct nlmsghdr *nlh;
699 struct nh_info *nhi;
700 struct nhmsg *nhm;
701
702 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
703 if (!nlh)
704 return -EMSGSIZE;
705
706 nhm = nlmsg_data(nlh);
707 nhm->nh_family = AF_UNSPEC;
708 nhm->nh_flags = nh->nh_flags;
709 nhm->nh_protocol = nh->protocol;
710 nhm->nh_scope = 0;
711 nhm->resvd = 0;
712
713 if (nla_put_u32(skb, NHA_ID, nh->id))
714 goto nla_put_failure;
715
716 if (nh->is_group) {
717 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
718
719 if (nhg->fdb_nh && nla_put_flag(skb, NHA_FDB))
720 goto nla_put_failure;
721 if (nla_put_nh_group(skb, nhg))
722 goto nla_put_failure;
723 goto out;
724 }
725
726 nhi = rtnl_dereference(nh->nh_info);
727 nhm->nh_family = nhi->family;
728 if (nhi->reject_nh) {
729 if (nla_put_flag(skb, NHA_BLACKHOLE))
730 goto nla_put_failure;
731 goto out;
732 } else if (nhi->fdb_nh) {
733 if (nla_put_flag(skb, NHA_FDB))
734 goto nla_put_failure;
735 } else {
736 const struct net_device *dev;
737
738 dev = nhi->fib_nhc.nhc_dev;
739 if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex))
740 goto nla_put_failure;
741 }
742
743 nhm->nh_scope = nhi->fib_nhc.nhc_scope;
744 switch (nhi->family) {
745 case AF_INET:
746 fib_nh = &nhi->fib_nh;
747 if (fib_nh->fib_nh_gw_family &&
748 nla_put_be32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4))
749 goto nla_put_failure;
750 break;
751
752 case AF_INET6:
753 fib6_nh = &nhi->fib6_nh;
754 if (fib6_nh->fib_nh_gw_family &&
755 nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->fib_nh_gw6))
756 goto nla_put_failure;
757 break;
758 }
759
760 if (nhi->fib_nhc.nhc_lwtstate &&
761 lwtunnel_fill_encap(skb, nhi->fib_nhc.nhc_lwtstate,
762 NHA_ENCAP, NHA_ENCAP_TYPE) < 0)
763 goto nla_put_failure;
764
765out:
766 nlmsg_end(skb, nlh);
767 return 0;
768
769nla_put_failure:
770 nlmsg_cancel(skb, nlh);
771 return -EMSGSIZE;
772}
773
774static size_t nh_nlmsg_size_grp_res(struct nh_group *nhg)
775{
776 return nla_total_size(0) + /* NHA_RES_GROUP */
777 nla_total_size(2) + /* NHA_RES_GROUP_BUCKETS */
778 nla_total_size(4) + /* NHA_RES_GROUP_IDLE_TIMER */
779 nla_total_size(4) + /* NHA_RES_GROUP_UNBALANCED_TIMER */
780 nla_total_size_64bit(8);/* NHA_RES_GROUP_UNBALANCED_TIME */
781}
782
783static size_t nh_nlmsg_size_grp(struct nexthop *nh)
784{
785 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
786 size_t sz = sizeof(struct nexthop_grp) * nhg->num_nh;
787 size_t tot = nla_total_size(sz) +
788 nla_total_size(2); /* NHA_GROUP_TYPE */
789
790 if (nhg->resilient)
791 tot += nh_nlmsg_size_grp_res(nhg);
792
793 return tot;
794}
795
796static size_t nh_nlmsg_size_single(struct nexthop *nh)
797{
798 struct nh_info *nhi = rtnl_dereference(nh->nh_info);
799 size_t sz;
800
801 /* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE
802 * are mutually exclusive
803 */
804 sz = nla_total_size(4); /* NHA_OIF */
805
806 switch (nhi->family) {
807 case AF_INET:
808 if (nhi->fib_nh.fib_nh_gw_family)
809 sz += nla_total_size(4); /* NHA_GATEWAY */
810 break;
811
812 case AF_INET6:
813 /* NHA_GATEWAY */
814 if (nhi->fib6_nh.fib_nh_gw_family)
815 sz += nla_total_size(sizeof(const struct in6_addr));
816 break;
817 }
818
819 if (nhi->fib_nhc.nhc_lwtstate) {
820 sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate);
821 sz += nla_total_size(2); /* NHA_ENCAP_TYPE */
822 }
823
824 return sz;
825}
826
827static size_t nh_nlmsg_size(struct nexthop *nh)
828{
829 size_t sz = NLMSG_ALIGN(sizeof(struct nhmsg));
830
831 sz += nla_total_size(4); /* NHA_ID */
832
833 if (nh->is_group)
834 sz += nh_nlmsg_size_grp(nh);
835 else
836 sz += nh_nlmsg_size_single(nh);
837
838 return sz;
839}
840
841static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info)
842{
843 unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0;
844 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
845 struct sk_buff *skb;
846 int err = -ENOBUFS;
847
848 skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any());
849 if (!skb)
850 goto errout;
851
852 err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags);
853 if (err < 0) {
854 /* -EMSGSIZE implies BUG in nh_nlmsg_size() */
855 WARN_ON(err == -EMSGSIZE);
856 kfree_skb(skb);
857 goto errout;
858 }
859
860 rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_NEXTHOP,
861 info->nlh, gfp_any());
862 return;
863errout:
864 if (err < 0)
865 rtnl_set_sk_err(info->nl_net, RTNLGRP_NEXTHOP, err);
866}
867
868static unsigned long nh_res_bucket_used_time(const struct nh_res_bucket *bucket)
869{
870 return (unsigned long)atomic_long_read(&bucket->used_time);
871}
872
873static unsigned long
874nh_res_bucket_idle_point(const struct nh_res_table *res_table,
875 const struct nh_res_bucket *bucket,
876 unsigned long now)
877{
878 unsigned long time = nh_res_bucket_used_time(bucket);
879
880 /* Bucket was not used since it was migrated. The idle time is now. */
881 if (time == bucket->migrated_time)
882 return now;
883
884 return time + res_table->idle_timer;
885}
886
887static unsigned long
888nh_res_table_unb_point(const struct nh_res_table *res_table)
889{
890 return res_table->unbalanced_since + res_table->unbalanced_timer;
891}
892
893static void nh_res_bucket_set_idle(const struct nh_res_table *res_table,
894 struct nh_res_bucket *bucket)
895{
896 unsigned long now = jiffies;
897
898 atomic_long_set(&bucket->used_time, (long)now);
899 bucket->migrated_time = now;
900}
901
902static void nh_res_bucket_set_busy(struct nh_res_bucket *bucket)
903{
904 atomic_long_set(&bucket->used_time, (long)jiffies);
905}
906
907static clock_t nh_res_bucket_idle_time(const struct nh_res_bucket *bucket)
908{
909 unsigned long used_time = nh_res_bucket_used_time(bucket);
910
911 return jiffies_delta_to_clock_t(jiffies - used_time);
912}
913
914static int nh_fill_res_bucket(struct sk_buff *skb, struct nexthop *nh,
915 struct nh_res_bucket *bucket, u16 bucket_index,
916 int event, u32 portid, u32 seq,
917 unsigned int nlflags,
918 struct netlink_ext_ack *extack)
919{
920 struct nh_grp_entry *nhge = nh_res_dereference(bucket->nh_entry);
921 struct nlmsghdr *nlh;
922 struct nlattr *nest;
923 struct nhmsg *nhm;
924
925 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
926 if (!nlh)
927 return -EMSGSIZE;
928
929 nhm = nlmsg_data(nlh);
930 nhm->nh_family = AF_UNSPEC;
931 nhm->nh_flags = bucket->nh_flags;
932 nhm->nh_protocol = nh->protocol;
933 nhm->nh_scope = 0;
934 nhm->resvd = 0;
935
936 if (nla_put_u32(skb, NHA_ID, nh->id))
937 goto nla_put_failure;
938
939 nest = nla_nest_start(skb, NHA_RES_BUCKET);
940 if (!nest)
941 goto nla_put_failure;
942
943 if (nla_put_u16(skb, NHA_RES_BUCKET_INDEX, bucket_index) ||
944 nla_put_u32(skb, NHA_RES_BUCKET_NH_ID, nhge->nh->id) ||
945 nla_put_u64_64bit(skb, NHA_RES_BUCKET_IDLE_TIME,
946 nh_res_bucket_idle_time(bucket),
947 NHA_RES_BUCKET_PAD))
948 goto nla_put_failure_nest;
949
950 nla_nest_end(skb, nest);
951 nlmsg_end(skb, nlh);
952 return 0;
953
954nla_put_failure_nest:
955 nla_nest_cancel(skb, nest);
956nla_put_failure:
957 nlmsg_cancel(skb, nlh);
958 return -EMSGSIZE;
959}
960
961static void nexthop_bucket_notify(struct nh_res_table *res_table,
962 u16 bucket_index)
963{
964 struct nh_res_bucket *bucket = &res_table->nh_buckets[bucket_index];
965 struct nh_grp_entry *nhge = nh_res_dereference(bucket->nh_entry);
966 struct nexthop *nh = nhge->nh_parent;
967 struct sk_buff *skb;
968 int err = -ENOBUFS;
969
970 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
971 if (!skb)
972 goto errout;
973
974 err = nh_fill_res_bucket(skb, nh, bucket, bucket_index,
975 RTM_NEWNEXTHOPBUCKET, 0, 0, NLM_F_REPLACE,
976 NULL);
977 if (err < 0) {
978 kfree_skb(skb);
979 goto errout;
980 }
981
982 rtnl_notify(skb, nh->net, 0, RTNLGRP_NEXTHOP, NULL, GFP_KERNEL);
983 return;
984errout:
985 if (err < 0)
986 rtnl_set_sk_err(nh->net, RTNLGRP_NEXTHOP, err);
987}
988
989static bool valid_group_nh(struct nexthop *nh, unsigned int npaths,
990 bool *is_fdb, struct netlink_ext_ack *extack)
991{
992 if (nh->is_group) {
993 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
994
995 /* Nesting groups within groups is not supported. */
996 if (nhg->hash_threshold) {
997 NL_SET_ERR_MSG(extack,
998 "Hash-threshold group can not be a nexthop within a group");
999 return false;
1000 }
1001 if (nhg->resilient) {
1002 NL_SET_ERR_MSG(extack,
1003 "Resilient group can not be a nexthop within a group");
1004 return false;
1005 }
1006 *is_fdb = nhg->fdb_nh;
1007 } else {
1008 struct nh_info *nhi = rtnl_dereference(nh->nh_info);
1009
1010 if (nhi->reject_nh && npaths > 1) {
1011 NL_SET_ERR_MSG(extack,
1012 "Blackhole nexthop can not be used in a group with more than 1 path");
1013 return false;
1014 }
1015 *is_fdb = nhi->fdb_nh;
1016 }
1017
1018 return true;
1019}
1020
1021static int nh_check_attr_fdb_group(struct nexthop *nh, u8 *nh_family,
1022 struct netlink_ext_ack *extack)
1023{
1024 struct nh_info *nhi;
1025
1026 nhi = rtnl_dereference(nh->nh_info);
1027
1028 if (!nhi->fdb_nh) {
1029 NL_SET_ERR_MSG(extack, "FDB nexthop group can only have fdb nexthops");
1030 return -EINVAL;
1031 }
1032
1033 if (*nh_family == AF_UNSPEC) {
1034 *nh_family = nhi->family;
1035 } else if (*nh_family != nhi->family) {
1036 NL_SET_ERR_MSG(extack, "FDB nexthop group cannot have mixed family nexthops");
1037 return -EINVAL;
1038 }
1039
1040 return 0;
1041}
1042
1043static int nh_check_attr_group(struct net *net,
1044 struct nlattr *tb[], size_t tb_size,
1045 u16 nh_grp_type, struct netlink_ext_ack *extack)
1046{
1047 unsigned int len = nla_len(tb[NHA_GROUP]);
1048 u8 nh_family = AF_UNSPEC;
1049 struct nexthop_grp *nhg;
1050 unsigned int i, j;
1051 u8 nhg_fdb = 0;
1052
1053 if (!len || len & (sizeof(struct nexthop_grp) - 1)) {
1054 NL_SET_ERR_MSG(extack,
1055 "Invalid length for nexthop group attribute");
1056 return -EINVAL;
1057 }
1058
1059 /* convert len to number of nexthop ids */
1060 len /= sizeof(*nhg);
1061
1062 nhg = nla_data(tb[NHA_GROUP]);
1063 for (i = 0; i < len; ++i) {
1064 if (nhg[i].resvd1 || nhg[i].resvd2) {
1065 NL_SET_ERR_MSG(extack, "Reserved fields in nexthop_grp must be 0");
1066 return -EINVAL;
1067 }
1068 if (nhg[i].weight > 254) {
1069 NL_SET_ERR_MSG(extack, "Invalid value for weight");
1070 return -EINVAL;
1071 }
1072 for (j = i + 1; j < len; ++j) {
1073 if (nhg[i].id == nhg[j].id) {
1074 NL_SET_ERR_MSG(extack, "Nexthop id can not be used twice in a group");
1075 return -EINVAL;
1076 }
1077 }
1078 }
1079
1080 if (tb[NHA_FDB])
1081 nhg_fdb = 1;
1082 nhg = nla_data(tb[NHA_GROUP]);
1083 for (i = 0; i < len; ++i) {
1084 struct nexthop *nh;
1085 bool is_fdb_nh;
1086
1087 nh = nexthop_find_by_id(net, nhg[i].id);
1088 if (!nh) {
1089 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
1090 return -EINVAL;
1091 }
1092 if (!valid_group_nh(nh, len, &is_fdb_nh, extack))
1093 return -EINVAL;
1094
1095 if (nhg_fdb && nh_check_attr_fdb_group(nh, &nh_family, extack))
1096 return -EINVAL;
1097
1098 if (!nhg_fdb && is_fdb_nh) {
1099 NL_SET_ERR_MSG(extack, "Non FDB nexthop group cannot have fdb nexthops");
1100 return -EINVAL;
1101 }
1102 }
1103 for (i = NHA_GROUP_TYPE + 1; i < tb_size; ++i) {
1104 if (!tb[i])
1105 continue;
1106 switch (i) {
1107 case NHA_FDB:
1108 continue;
1109 case NHA_RES_GROUP:
1110 if (nh_grp_type == NEXTHOP_GRP_TYPE_RES)
1111 continue;
1112 break;
1113 }
1114 NL_SET_ERR_MSG(extack,
1115 "No other attributes can be set in nexthop groups");
1116 return -EINVAL;
1117 }
1118
1119 return 0;
1120}
1121
1122static bool ipv6_good_nh(const struct fib6_nh *nh)
1123{
1124 int state = NUD_REACHABLE;
1125 struct neighbour *n;
1126
1127 rcu_read_lock_bh();
1128
1129 n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6);
1130 if (n)
1131 state = n->nud_state;
1132
1133 rcu_read_unlock_bh();
1134
1135 return !!(state & NUD_VALID);
1136}
1137
1138static bool ipv4_good_nh(const struct fib_nh *nh)
1139{
1140 int state = NUD_REACHABLE;
1141 struct neighbour *n;
1142
1143 rcu_read_lock_bh();
1144
1145 n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev,
1146 (__force u32)nh->fib_nh_gw4);
1147 if (n)
1148 state = n->nud_state;
1149
1150 rcu_read_unlock_bh();
1151
1152 return !!(state & NUD_VALID);
1153}
1154
1155static struct nexthop *nexthop_select_path_hthr(struct nh_group *nhg, int hash)
1156{
1157 struct nexthop *rc = NULL;
1158 int i;
1159
1160 for (i = 0; i < nhg->num_nh; ++i) {
1161 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
1162 struct nh_info *nhi;
1163
1164 if (hash > atomic_read(&nhge->hthr.upper_bound))
1165 continue;
1166
1167 nhi = rcu_dereference(nhge->nh->nh_info);
1168 if (nhi->fdb_nh)
1169 return nhge->nh;
1170
1171 /* nexthops always check if it is good and does
1172 * not rely on a sysctl for this behavior
1173 */
1174 switch (nhi->family) {
1175 case AF_INET:
1176 if (ipv4_good_nh(&nhi->fib_nh))
1177 return nhge->nh;
1178 break;
1179 case AF_INET6:
1180 if (ipv6_good_nh(&nhi->fib6_nh))
1181 return nhge->nh;
1182 break;
1183 }
1184
1185 if (!rc)
1186 rc = nhge->nh;
1187 }
1188
1189 return rc;
1190}
1191
1192static struct nexthop *nexthop_select_path_res(struct nh_group *nhg, int hash)
1193{
1194 struct nh_res_table *res_table = rcu_dereference(nhg->res_table);
1195 u16 bucket_index = hash % res_table->num_nh_buckets;
1196 struct nh_res_bucket *bucket;
1197 struct nh_grp_entry *nhge;
1198
1199 /* nexthop_select_path() is expected to return a non-NULL value, so
1200 * skip protocol validation and just hand out whatever there is.
1201 */
1202 bucket = &res_table->nh_buckets[bucket_index];
1203 nh_res_bucket_set_busy(bucket);
1204 nhge = rcu_dereference(bucket->nh_entry);
1205 return nhge->nh;
1206}
1207
1208struct nexthop *nexthop_select_path(struct nexthop *nh, int hash)
1209{
1210 struct nh_group *nhg;
1211
1212 if (!nh->is_group)
1213 return nh;
1214
1215 nhg = rcu_dereference(nh->nh_grp);
1216 if (nhg->hash_threshold)
1217 return nexthop_select_path_hthr(nhg, hash);
1218 else if (nhg->resilient)
1219 return nexthop_select_path_res(nhg, hash);
1220
1221 /* Unreachable. */
1222 return NULL;
1223}
1224EXPORT_SYMBOL_GPL(nexthop_select_path);
1225
1226int nexthop_for_each_fib6_nh(struct nexthop *nh,
1227 int (*cb)(struct fib6_nh *nh, void *arg),
1228 void *arg)
1229{
1230 struct nh_info *nhi;
1231 int err;
1232
1233 if (nh->is_group) {
1234 struct nh_group *nhg;
1235 int i;
1236
1237 nhg = rcu_dereference_rtnl(nh->nh_grp);
1238 for (i = 0; i < nhg->num_nh; i++) {
1239 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
1240
1241 nhi = rcu_dereference_rtnl(nhge->nh->nh_info);
1242 err = cb(&nhi->fib6_nh, arg);
1243 if (err)
1244 return err;
1245 }
1246 } else {
1247 nhi = rcu_dereference_rtnl(nh->nh_info);
1248 err = cb(&nhi->fib6_nh, arg);
1249 if (err)
1250 return err;
1251 }
1252
1253 return 0;
1254}
1255EXPORT_SYMBOL_GPL(nexthop_for_each_fib6_nh);
1256
1257static int check_src_addr(const struct in6_addr *saddr,
1258 struct netlink_ext_ack *extack)
1259{
1260 if (!ipv6_addr_any(saddr)) {
1261 NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects");
1262 return -EINVAL;
1263 }
1264 return 0;
1265}
1266
1267int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
1268 struct netlink_ext_ack *extack)
1269{
1270 struct nh_info *nhi;
1271 bool is_fdb_nh;
1272
1273 /* fib6_src is unique to a fib6_info and limits the ability to cache
1274 * routes in fib6_nh within a nexthop that is potentially shared
1275 * across multiple fib entries. If the config wants to use source
1276 * routing it can not use nexthop objects. mlxsw also does not allow
1277 * fib6_src on routes.
1278 */
1279 if (cfg && check_src_addr(&cfg->fc_src, extack) < 0)
1280 return -EINVAL;
1281
1282 if (nh->is_group) {
1283 struct nh_group *nhg;
1284
1285 nhg = rtnl_dereference(nh->nh_grp);
1286 if (nhg->has_v4)
1287 goto no_v4_nh;
1288 is_fdb_nh = nhg->fdb_nh;
1289 } else {
1290 nhi = rtnl_dereference(nh->nh_info);
1291 if (nhi->family == AF_INET)
1292 goto no_v4_nh;
1293 is_fdb_nh = nhi->fdb_nh;
1294 }
1295
1296 if (is_fdb_nh) {
1297 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
1298 return -EINVAL;
1299 }
1300
1301 return 0;
1302no_v4_nh:
1303 NL_SET_ERR_MSG(extack, "IPv6 routes can not use an IPv4 nexthop");
1304 return -EINVAL;
1305}
1306EXPORT_SYMBOL_GPL(fib6_check_nexthop);
1307
1308/* if existing nexthop has ipv6 routes linked to it, need
1309 * to verify this new spec works with ipv6
1310 */
1311static int fib6_check_nh_list(struct nexthop *old, struct nexthop *new,
1312 struct netlink_ext_ack *extack)
1313{
1314 struct fib6_info *f6i;
1315
1316 if (list_empty(&old->f6i_list))
1317 return 0;
1318
1319 list_for_each_entry(f6i, &old->f6i_list, nh_list) {
1320 if (check_src_addr(&f6i->fib6_src.addr, extack) < 0)
1321 return -EINVAL;
1322 }
1323
1324 return fib6_check_nexthop(new, NULL, extack);
1325}
1326
1327static int nexthop_check_scope(struct nh_info *nhi, u8 scope,
1328 struct netlink_ext_ack *extack)
1329{
1330 if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) {
1331 NL_SET_ERR_MSG(extack,
1332 "Route with host scope can not have a gateway");
1333 return -EINVAL;
1334 }
1335
1336 if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) {
1337 NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop");
1338 return -EINVAL;
1339 }
1340
1341 return 0;
1342}
1343
1344/* Invoked by fib add code to verify nexthop by id is ok with
1345 * config for prefix; parts of fib_check_nh not done when nexthop
1346 * object is used.
1347 */
1348int fib_check_nexthop(struct nexthop *nh, u8 scope,
1349 struct netlink_ext_ack *extack)
1350{
1351 struct nh_info *nhi;
1352 int err = 0;
1353
1354 if (nh->is_group) {
1355 struct nh_group *nhg;
1356
1357 nhg = rtnl_dereference(nh->nh_grp);
1358 if (nhg->fdb_nh) {
1359 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
1360 err = -EINVAL;
1361 goto out;
1362 }
1363
1364 if (scope == RT_SCOPE_HOST) {
1365 NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops");
1366 err = -EINVAL;
1367 goto out;
1368 }
1369
1370 /* all nexthops in a group have the same scope */
1371 nhi = rtnl_dereference(nhg->nh_entries[0].nh->nh_info);
1372 err = nexthop_check_scope(nhi, scope, extack);
1373 } else {
1374 nhi = rtnl_dereference(nh->nh_info);
1375 if (nhi->fdb_nh) {
1376 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
1377 err = -EINVAL;
1378 goto out;
1379 }
1380 err = nexthop_check_scope(nhi, scope, extack);
1381 }
1382
1383out:
1384 return err;
1385}
1386
1387static int fib_check_nh_list(struct nexthop *old, struct nexthop *new,
1388 struct netlink_ext_ack *extack)
1389{
1390 struct fib_info *fi;
1391
1392 list_for_each_entry(fi, &old->fi_list, nh_list) {
1393 int err;
1394
1395 err = fib_check_nexthop(new, fi->fib_scope, extack);
1396 if (err)
1397 return err;
1398 }
1399 return 0;
1400}
1401
1402static bool nh_res_nhge_is_balanced(const struct nh_grp_entry *nhge)
1403{
1404 return nhge->res.count_buckets == nhge->res.wants_buckets;
1405}
1406
1407static bool nh_res_nhge_is_ow(const struct nh_grp_entry *nhge)
1408{
1409 return nhge->res.count_buckets > nhge->res.wants_buckets;
1410}
1411
1412static bool nh_res_nhge_is_uw(const struct nh_grp_entry *nhge)
1413{
1414 return nhge->res.count_buckets < nhge->res.wants_buckets;
1415}
1416
1417static bool nh_res_table_is_balanced(const struct nh_res_table *res_table)
1418{
1419 return list_empty(&res_table->uw_nh_entries);
1420}
1421
1422static void nh_res_bucket_unset_nh(struct nh_res_bucket *bucket)
1423{
1424 struct nh_grp_entry *nhge;
1425
1426 if (bucket->occupied) {
1427 nhge = nh_res_dereference(bucket->nh_entry);
1428 nhge->res.count_buckets--;
1429 bucket->occupied = false;
1430 }
1431}
1432
1433static void nh_res_bucket_set_nh(struct nh_res_bucket *bucket,
1434 struct nh_grp_entry *nhge)
1435{
1436 nh_res_bucket_unset_nh(bucket);
1437
1438 bucket->occupied = true;
1439 rcu_assign_pointer(bucket->nh_entry, nhge);
1440 nhge->res.count_buckets++;
1441}
1442
1443static bool nh_res_bucket_should_migrate(struct nh_res_table *res_table,
1444 struct nh_res_bucket *bucket,
1445 unsigned long *deadline, bool *force)
1446{
1447 unsigned long now = jiffies;
1448 struct nh_grp_entry *nhge;
1449 unsigned long idle_point;
1450
1451 if (!bucket->occupied) {
1452 /* The bucket is not occupied, its NHGE pointer is either
1453 * NULL or obsolete. We _have to_ migrate: set force.
1454 */
1455 *force = true;
1456 return true;
1457 }
1458
1459 nhge = nh_res_dereference(bucket->nh_entry);
1460
1461 /* If the bucket is populated by an underweight or balanced
1462 * nexthop, do not migrate.
1463 */
1464 if (!nh_res_nhge_is_ow(nhge))
1465 return false;
1466
1467 /* At this point we know that the bucket is populated with an
1468 * overweight nexthop. It needs to be migrated to a new nexthop if
1469 * the idle timer of unbalanced timer expired.
1470 */
1471
1472 idle_point = nh_res_bucket_idle_point(res_table, bucket, now);
1473 if (time_after_eq(now, idle_point)) {
1474 /* The bucket is idle. We _can_ migrate: unset force. */
1475 *force = false;
1476 return true;
1477 }
1478
1479 /* Unbalanced timer of 0 means "never force". */
1480 if (res_table->unbalanced_timer) {
1481 unsigned long unb_point;
1482
1483 unb_point = nh_res_table_unb_point(res_table);
1484 if (time_after(now, unb_point)) {
1485 /* The bucket is not idle, but the unbalanced timer
1486 * expired. We _can_ migrate, but set force anyway,
1487 * so that drivers know to ignore activity reports
1488 * from the HW.
1489 */
1490 *force = true;
1491 return true;
1492 }
1493
1494 nh_res_time_set_deadline(unb_point, deadline);
1495 }
1496
1497 nh_res_time_set_deadline(idle_point, deadline);
1498 return false;
1499}
1500
1501static bool nh_res_bucket_migrate(struct nh_res_table *res_table,
1502 u16 bucket_index, bool notify,
1503 bool notify_nl, bool force)
1504{
1505 struct nh_res_bucket *bucket = &res_table->nh_buckets[bucket_index];
1506 struct nh_grp_entry *new_nhge;
1507 struct netlink_ext_ack extack;
1508 int err;
1509
1510 new_nhge = list_first_entry_or_null(&res_table->uw_nh_entries,
1511 struct nh_grp_entry,
1512 res.uw_nh_entry);
1513 if (WARN_ON_ONCE(!new_nhge))
1514 /* If this function is called, "bucket" is either not
1515 * occupied, or it belongs to a next hop that is
1516 * overweight. In either case, there ought to be a
1517 * corresponding underweight next hop.
1518 */
1519 return false;
1520
1521 if (notify) {
1522 struct nh_grp_entry *old_nhge;
1523
1524 old_nhge = nh_res_dereference(bucket->nh_entry);
1525 err = call_nexthop_res_bucket_notifiers(res_table->net,
1526 res_table->nhg_id,
1527 bucket_index, force,
1528 old_nhge->nh,
1529 new_nhge->nh, &extack);
1530 if (err) {
1531 pr_err_ratelimited("%s\n", extack._msg);
1532 if (!force)
1533 return false;
1534 /* It is not possible to veto a forced replacement, so
1535 * just clear the hardware flags from the nexthop
1536 * bucket to indicate to user space that this bucket is
1537 * not correctly populated in hardware.
1538 */
1539 bucket->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP);
1540 }
1541 }
1542
1543 nh_res_bucket_set_nh(bucket, new_nhge);
1544 nh_res_bucket_set_idle(res_table, bucket);
1545
1546 if (notify_nl)
1547 nexthop_bucket_notify(res_table, bucket_index);
1548
1549 if (nh_res_nhge_is_balanced(new_nhge))
1550 list_del(&new_nhge->res.uw_nh_entry);
1551 return true;
1552}
1553
1554#define NH_RES_UPKEEP_DW_MINIMUM_INTERVAL (HZ / 2)
1555
1556static void nh_res_table_upkeep(struct nh_res_table *res_table,
1557 bool notify, bool notify_nl)
1558{
1559 unsigned long now = jiffies;
1560 unsigned long deadline;
1561 u16 i;
1562
1563 /* Deadline is the next time that upkeep should be run. It is the
1564 * earliest time at which one of the buckets might be migrated.
1565 * Start at the most pessimistic estimate: either unbalanced_timer
1566 * from now, or if there is none, idle_timer from now. For each
1567 * encountered time point, call nh_res_time_set_deadline() to
1568 * refine the estimate.
1569 */
1570 if (res_table->unbalanced_timer)
1571 deadline = now + res_table->unbalanced_timer;
1572 else
1573 deadline = now + res_table->idle_timer;
1574
1575 for (i = 0; i < res_table->num_nh_buckets; i++) {
1576 struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
1577 bool force;
1578
1579 if (nh_res_bucket_should_migrate(res_table, bucket,
1580 &deadline, &force)) {
1581 if (!nh_res_bucket_migrate(res_table, i, notify,
1582 notify_nl, force)) {
1583 unsigned long idle_point;
1584
1585 /* A driver can override the migration
1586 * decision if the HW reports that the
1587 * bucket is actually not idle. Therefore
1588 * remark the bucket as busy again and
1589 * update the deadline.
1590 */
1591 nh_res_bucket_set_busy(bucket);
1592 idle_point = nh_res_bucket_idle_point(res_table,
1593 bucket,
1594 now);
1595 nh_res_time_set_deadline(idle_point, &deadline);
1596 }
1597 }
1598 }
1599
1600 /* If the group is still unbalanced, schedule the next upkeep to
1601 * either the deadline computed above, or the minimum deadline,
1602 * whichever comes later.
1603 */
1604 if (!nh_res_table_is_balanced(res_table)) {
1605 unsigned long now = jiffies;
1606 unsigned long min_deadline;
1607
1608 min_deadline = now + NH_RES_UPKEEP_DW_MINIMUM_INTERVAL;
1609 if (time_before(deadline, min_deadline))
1610 deadline = min_deadline;
1611
1612 queue_delayed_work(system_power_efficient_wq,
1613 &res_table->upkeep_dw, deadline - now);
1614 }
1615}
1616
1617static void nh_res_table_upkeep_dw(struct work_struct *work)
1618{
1619 struct delayed_work *dw = to_delayed_work(work);
1620 struct nh_res_table *res_table;
1621
1622 res_table = container_of(dw, struct nh_res_table, upkeep_dw);
1623 nh_res_table_upkeep(res_table, true, true);
1624}
1625
1626static void nh_res_table_cancel_upkeep(struct nh_res_table *res_table)
1627{
1628 cancel_delayed_work_sync(&res_table->upkeep_dw);
1629}
1630
1631static void nh_res_group_rebalance(struct nh_group *nhg,
1632 struct nh_res_table *res_table)
1633{
1634 int prev_upper_bound = 0;
1635 int total = 0;
1636 int w = 0;
1637 int i;
1638
1639 INIT_LIST_HEAD(&res_table->uw_nh_entries);
1640
1641 for (i = 0; i < nhg->num_nh; ++i)
1642 total += nhg->nh_entries[i].weight;
1643
1644 for (i = 0; i < nhg->num_nh; ++i) {
1645 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
1646 int upper_bound;
1647
1648 w += nhge->weight;
1649 upper_bound = DIV_ROUND_CLOSEST(res_table->num_nh_buckets * w,
1650 total);
1651 nhge->res.wants_buckets = upper_bound - prev_upper_bound;
1652 prev_upper_bound = upper_bound;
1653
1654 if (nh_res_nhge_is_uw(nhge)) {
1655 if (list_empty(&res_table->uw_nh_entries))
1656 res_table->unbalanced_since = jiffies;
1657 list_add(&nhge->res.uw_nh_entry,
1658 &res_table->uw_nh_entries);
1659 }
1660 }
1661}
1662
1663/* Migrate buckets in res_table so that they reference NHGE's from NHG with
1664 * the right NH ID. Set those buckets that do not have a corresponding NHGE
1665 * entry in NHG as not occupied.
1666 */
1667static void nh_res_table_migrate_buckets(struct nh_res_table *res_table,
1668 struct nh_group *nhg)
1669{
1670 u16 i;
1671
1672 for (i = 0; i < res_table->num_nh_buckets; i++) {
1673 struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
1674 u32 id = rtnl_dereference(bucket->nh_entry)->nh->id;
1675 bool found = false;
1676 int j;
1677
1678 for (j = 0; j < nhg->num_nh; j++) {
1679 struct nh_grp_entry *nhge = &nhg->nh_entries[j];
1680
1681 if (nhge->nh->id == id) {
1682 nh_res_bucket_set_nh(bucket, nhge);
1683 found = true;
1684 break;
1685 }
1686 }
1687
1688 if (!found)
1689 nh_res_bucket_unset_nh(bucket);
1690 }
1691}
1692
1693static void replace_nexthop_grp_res(struct nh_group *oldg,
1694 struct nh_group *newg)
1695{
1696 /* For NH group replacement, the new NHG might only have a stub
1697 * hash table with 0 buckets, because the number of buckets was not
1698 * specified. For NH removal, oldg and newg both reference the same
1699 * res_table. So in any case, in the following, we want to work
1700 * with oldg->res_table.
1701 */
1702 struct nh_res_table *old_res_table = rtnl_dereference(oldg->res_table);
1703 unsigned long prev_unbalanced_since = old_res_table->unbalanced_since;
1704 bool prev_has_uw = !list_empty(&old_res_table->uw_nh_entries);
1705
1706 nh_res_table_cancel_upkeep(old_res_table);
1707 nh_res_table_migrate_buckets(old_res_table, newg);
1708 nh_res_group_rebalance(newg, old_res_table);
1709 if (prev_has_uw && !list_empty(&old_res_table->uw_nh_entries))
1710 old_res_table->unbalanced_since = prev_unbalanced_since;
1711 nh_res_table_upkeep(old_res_table, true, false);
1712}
1713
1714static void nh_hthr_group_rebalance(struct nh_group *nhg)
1715{
1716 int total = 0;
1717 int w = 0;
1718 int i;
1719
1720 for (i = 0; i < nhg->num_nh; ++i)
1721 total += nhg->nh_entries[i].weight;
1722
1723 for (i = 0; i < nhg->num_nh; ++i) {
1724 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
1725 int upper_bound;
1726
1727 w += nhge->weight;
1728 upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, total) - 1;
1729 atomic_set(&nhge->hthr.upper_bound, upper_bound);
1730 }
1731}
1732
1733static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge,
1734 struct nl_info *nlinfo)
1735{
1736 struct nh_grp_entry *nhges, *new_nhges;
1737 struct nexthop *nhp = nhge->nh_parent;
1738 struct netlink_ext_ack extack;
1739 struct nexthop *nh = nhge->nh;
1740 struct nh_group *nhg, *newg;
1741 int i, j, err;
1742
1743 WARN_ON(!nh);
1744
1745 nhg = rtnl_dereference(nhp->nh_grp);
1746 newg = nhg->spare;
1747
1748 /* last entry, keep it visible and remove the parent */
1749 if (nhg->num_nh == 1) {
1750 remove_nexthop(net, nhp, nlinfo);
1751 return;
1752 }
1753
1754 newg->has_v4 = false;
1755 newg->is_multipath = nhg->is_multipath;
1756 newg->hash_threshold = nhg->hash_threshold;
1757 newg->resilient = nhg->resilient;
1758 newg->fdb_nh = nhg->fdb_nh;
1759 newg->num_nh = nhg->num_nh;
1760
1761 /* copy old entries to new except the one getting removed */
1762 nhges = nhg->nh_entries;
1763 new_nhges = newg->nh_entries;
1764 for (i = 0, j = 0; i < nhg->num_nh; ++i) {
1765 struct nh_info *nhi;
1766
1767 /* current nexthop getting removed */
1768 if (nhg->nh_entries[i].nh == nh) {
1769 newg->num_nh--;
1770 continue;
1771 }
1772
1773 nhi = rtnl_dereference(nhges[i].nh->nh_info);
1774 if (nhi->family == AF_INET)
1775 newg->has_v4 = true;
1776
1777 list_del(&nhges[i].nh_list);
1778 new_nhges[j].nh_parent = nhges[i].nh_parent;
1779 new_nhges[j].nh = nhges[i].nh;
1780 new_nhges[j].weight = nhges[i].weight;
1781 list_add(&new_nhges[j].nh_list, &new_nhges[j].nh->grp_list);
1782 j++;
1783 }
1784
1785 if (newg->hash_threshold)
1786 nh_hthr_group_rebalance(newg);
1787 else if (newg->resilient)
1788 replace_nexthop_grp_res(nhg, newg);
1789
1790 rcu_assign_pointer(nhp->nh_grp, newg);
1791
1792 list_del(&nhge->nh_list);
1793 nexthop_put(nhge->nh);
1794
1795 /* Removal of a NH from a resilient group is notified through
1796 * bucket notifications.
1797 */
1798 if (newg->hash_threshold) {
1799 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, nhp,
1800 &extack);
1801 if (err)
1802 pr_err("%s\n", extack._msg);
1803 }
1804
1805 if (nlinfo)
1806 nexthop_notify(RTM_NEWNEXTHOP, nhp, nlinfo);
1807}
1808
1809static void remove_nexthop_from_groups(struct net *net, struct nexthop *nh,
1810 struct nl_info *nlinfo)
1811{
1812 struct nh_grp_entry *nhge, *tmp;
1813
1814 list_for_each_entry_safe(nhge, tmp, &nh->grp_list, nh_list)
1815 remove_nh_grp_entry(net, nhge, nlinfo);
1816
1817 /* make sure all see the newly published array before releasing rtnl */
1818 synchronize_net();
1819}
1820
1821static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo)
1822{
1823 struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp);
1824 struct nh_res_table *res_table;
1825 int i, num_nh = nhg->num_nh;
1826
1827 for (i = 0; i < num_nh; ++i) {
1828 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
1829
1830 if (WARN_ON(!nhge->nh))
1831 continue;
1832
1833 list_del_init(&nhge->nh_list);
1834 }
1835
1836 if (nhg->resilient) {
1837 res_table = rtnl_dereference(nhg->res_table);
1838 nh_res_table_cancel_upkeep(res_table);
1839 }
1840}
1841
1842/* not called for nexthop replace */
1843static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
1844{
1845 struct fib6_info *f6i, *tmp;
1846 bool do_flush = false;
1847 struct fib_info *fi;
1848
1849 list_for_each_entry(fi, &nh->fi_list, nh_list) {
1850 fi->fib_flags |= RTNH_F_DEAD;
1851 do_flush = true;
1852 }
1853 if (do_flush)
1854 fib_flush(net);
1855
1856 /* ip6_del_rt removes the entry from this list hence the _safe */
1857 list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) {
1858 /* __ip6_del_rt does a release, so do a hold here */
1859 fib6_info_hold(f6i);
1860 ipv6_stub->ip6_del_rt(net, f6i,
1861 !READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode));
1862 }
1863}
1864
1865static void __remove_nexthop(struct net *net, struct nexthop *nh,
1866 struct nl_info *nlinfo)
1867{
1868 __remove_nexthop_fib(net, nh);
1869
1870 if (nh->is_group) {
1871 remove_nexthop_group(nh, nlinfo);
1872 } else {
1873 struct nh_info *nhi;
1874
1875 nhi = rtnl_dereference(nh->nh_info);
1876 if (nhi->fib_nhc.nhc_dev)
1877 hlist_del(&nhi->dev_hash);
1878
1879 remove_nexthop_from_groups(net, nh, nlinfo);
1880 }
1881}
1882
1883static void remove_nexthop(struct net *net, struct nexthop *nh,
1884 struct nl_info *nlinfo)
1885{
1886 call_nexthop_notifiers(net, NEXTHOP_EVENT_DEL, nh, NULL);
1887
1888 /* remove from the tree */
1889 rb_erase(&nh->rb_node, &net->nexthop.rb_root);
1890
1891 if (nlinfo)
1892 nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo);
1893
1894 __remove_nexthop(net, nh, nlinfo);
1895 nh_base_seq_inc(net);
1896
1897 nexthop_put(nh);
1898}
1899
1900/* if any FIB entries reference this nexthop, any dst entries
1901 * need to be regenerated
1902 */
1903static void nh_rt_cache_flush(struct net *net, struct nexthop *nh,
1904 struct nexthop *replaced_nh)
1905{
1906 struct fib6_info *f6i;
1907 struct nh_group *nhg;
1908 int i;
1909
1910 if (!list_empty(&nh->fi_list))
1911 rt_cache_flush(net);
1912
1913 list_for_each_entry(f6i, &nh->f6i_list, nh_list)
1914 ipv6_stub->fib6_update_sernum(net, f6i);
1915
1916 /* if an IPv6 group was replaced, we have to release all old
1917 * dsts to make sure all refcounts are released
1918 */
1919 if (!replaced_nh->is_group)
1920 return;
1921
1922 nhg = rtnl_dereference(replaced_nh->nh_grp);
1923 for (i = 0; i < nhg->num_nh; i++) {
1924 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
1925 struct nh_info *nhi = rtnl_dereference(nhge->nh->nh_info);
1926
1927 if (nhi->family == AF_INET6)
1928 ipv6_stub->fib6_nh_release_dsts(&nhi->fib6_nh);
1929 }
1930}
1931
1932static int replace_nexthop_grp(struct net *net, struct nexthop *old,
1933 struct nexthop *new, const struct nh_config *cfg,
1934 struct netlink_ext_ack *extack)
1935{
1936 struct nh_res_table *tmp_table = NULL;
1937 struct nh_res_table *new_res_table;
1938 struct nh_res_table *old_res_table;
1939 struct nh_group *oldg, *newg;
1940 int i, err;
1941
1942 if (!new->is_group) {
1943 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop.");
1944 return -EINVAL;
1945 }
1946
1947 oldg = rtnl_dereference(old->nh_grp);
1948 newg = rtnl_dereference(new->nh_grp);
1949
1950 if (newg->hash_threshold != oldg->hash_threshold) {
1951 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with one of a different type.");
1952 return -EINVAL;
1953 }
1954
1955 if (newg->hash_threshold) {
1956 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new,
1957 extack);
1958 if (err)
1959 return err;
1960 } else if (newg->resilient) {
1961 new_res_table = rtnl_dereference(newg->res_table);
1962 old_res_table = rtnl_dereference(oldg->res_table);
1963
1964 /* Accept if num_nh_buckets was not given, but if it was
1965 * given, demand that the value be correct.
1966 */
1967 if (cfg->nh_grp_res_has_num_buckets &&
1968 cfg->nh_grp_res_num_buckets !=
1969 old_res_table->num_nh_buckets) {
1970 NL_SET_ERR_MSG(extack, "Can not change number of buckets of a resilient nexthop group.");
1971 return -EINVAL;
1972 }
1973
1974 /* Emit a pre-replace notification so that listeners could veto
1975 * a potentially unsupported configuration. Otherwise,
1976 * individual bucket replacement notifications would need to be
1977 * vetoed, which is something that should only happen if the
1978 * bucket is currently active.
1979 */
1980 err = call_nexthop_res_table_notifiers(net, new, extack);
1981 if (err)
1982 return err;
1983
1984 if (cfg->nh_grp_res_has_idle_timer)
1985 old_res_table->idle_timer = cfg->nh_grp_res_idle_timer;
1986 if (cfg->nh_grp_res_has_unbalanced_timer)
1987 old_res_table->unbalanced_timer =
1988 cfg->nh_grp_res_unbalanced_timer;
1989
1990 replace_nexthop_grp_res(oldg, newg);
1991
1992 tmp_table = new_res_table;
1993 rcu_assign_pointer(newg->res_table, old_res_table);
1994 rcu_assign_pointer(newg->spare->res_table, old_res_table);
1995 }
1996
1997 /* update parents - used by nexthop code for cleanup */
1998 for (i = 0; i < newg->num_nh; i++)
1999 newg->nh_entries[i].nh_parent = old;
2000
2001 rcu_assign_pointer(old->nh_grp, newg);
2002
2003 /* Make sure concurrent readers are not using 'oldg' anymore. */
2004 synchronize_net();
2005
2006 if (newg->resilient) {
2007 rcu_assign_pointer(oldg->res_table, tmp_table);
2008 rcu_assign_pointer(oldg->spare->res_table, tmp_table);
2009 }
2010
2011 for (i = 0; i < oldg->num_nh; i++)
2012 oldg->nh_entries[i].nh_parent = new;
2013
2014 rcu_assign_pointer(new->nh_grp, oldg);
2015
2016 return 0;
2017}
2018
2019static void nh_group_v4_update(struct nh_group *nhg)
2020{
2021 struct nh_grp_entry *nhges;
2022 bool has_v4 = false;
2023 int i;
2024
2025 nhges = nhg->nh_entries;
2026 for (i = 0; i < nhg->num_nh; i++) {
2027 struct nh_info *nhi;
2028
2029 nhi = rtnl_dereference(nhges[i].nh->nh_info);
2030 if (nhi->family == AF_INET)
2031 has_v4 = true;
2032 }
2033 nhg->has_v4 = has_v4;
2034}
2035
2036static int replace_nexthop_single_notify_res(struct net *net,
2037 struct nh_res_table *res_table,
2038 struct nexthop *old,
2039 struct nh_info *oldi,
2040 struct nh_info *newi,
2041 struct netlink_ext_ack *extack)
2042{
2043 u32 nhg_id = res_table->nhg_id;
2044 int err;
2045 u16 i;
2046
2047 for (i = 0; i < res_table->num_nh_buckets; i++) {
2048 struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
2049 struct nh_grp_entry *nhge;
2050
2051 nhge = rtnl_dereference(bucket->nh_entry);
2052 if (nhge->nh == old) {
2053 err = __call_nexthop_res_bucket_notifiers(net, nhg_id,
2054 i, true,
2055 oldi, newi,
2056 extack);
2057 if (err)
2058 goto err_notify;
2059 }
2060 }
2061
2062 return 0;
2063
2064err_notify:
2065 while (i-- > 0) {
2066 struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
2067 struct nh_grp_entry *nhge;
2068
2069 nhge = rtnl_dereference(bucket->nh_entry);
2070 if (nhge->nh == old)
2071 __call_nexthop_res_bucket_notifiers(net, nhg_id, i,
2072 true, newi, oldi,
2073 extack);
2074 }
2075 return err;
2076}
2077
2078static int replace_nexthop_single_notify(struct net *net,
2079 struct nexthop *group_nh,
2080 struct nexthop *old,
2081 struct nh_info *oldi,
2082 struct nh_info *newi,
2083 struct netlink_ext_ack *extack)
2084{
2085 struct nh_group *nhg = rtnl_dereference(group_nh->nh_grp);
2086 struct nh_res_table *res_table;
2087
2088 if (nhg->hash_threshold) {
2089 return call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE,
2090 group_nh, extack);
2091 } else if (nhg->resilient) {
2092 res_table = rtnl_dereference(nhg->res_table);
2093 return replace_nexthop_single_notify_res(net, res_table,
2094 old, oldi, newi,
2095 extack);
2096 }
2097
2098 return -EINVAL;
2099}
2100
2101static int replace_nexthop_single(struct net *net, struct nexthop *old,
2102 struct nexthop *new,
2103 struct netlink_ext_ack *extack)
2104{
2105 u8 old_protocol, old_nh_flags;
2106 struct nh_info *oldi, *newi;
2107 struct nh_grp_entry *nhge;
2108 int err;
2109
2110 if (new->is_group) {
2111 NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group.");
2112 return -EINVAL;
2113 }
2114
2115 err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new, extack);
2116 if (err)
2117 return err;
2118
2119 /* Hardware flags were set on 'old' as 'new' is not in the red-black
2120 * tree. Therefore, inherit the flags from 'old' to 'new'.
2121 */
2122 new->nh_flags |= old->nh_flags & (RTNH_F_OFFLOAD | RTNH_F_TRAP);
2123
2124 oldi = rtnl_dereference(old->nh_info);
2125 newi = rtnl_dereference(new->nh_info);
2126
2127 newi->nh_parent = old;
2128 oldi->nh_parent = new;
2129
2130 old_protocol = old->protocol;
2131 old_nh_flags = old->nh_flags;
2132
2133 old->protocol = new->protocol;
2134 old->nh_flags = new->nh_flags;
2135
2136 rcu_assign_pointer(old->nh_info, newi);
2137 rcu_assign_pointer(new->nh_info, oldi);
2138
2139 /* Send a replace notification for all the groups using the nexthop. */
2140 list_for_each_entry(nhge, &old->grp_list, nh_list) {
2141 struct nexthop *nhp = nhge->nh_parent;
2142
2143 err = replace_nexthop_single_notify(net, nhp, old, oldi, newi,
2144 extack);
2145 if (err)
2146 goto err_notify;
2147 }
2148
2149 /* When replacing an IPv4 nexthop with an IPv6 nexthop, potentially
2150 * update IPv4 indication in all the groups using the nexthop.
2151 */
2152 if (oldi->family == AF_INET && newi->family == AF_INET6) {
2153 list_for_each_entry(nhge, &old->grp_list, nh_list) {
2154 struct nexthop *nhp = nhge->nh_parent;
2155 struct nh_group *nhg;
2156
2157 nhg = rtnl_dereference(nhp->nh_grp);
2158 nh_group_v4_update(nhg);
2159 }
2160 }
2161
2162 return 0;
2163
2164err_notify:
2165 rcu_assign_pointer(new->nh_info, newi);
2166 rcu_assign_pointer(old->nh_info, oldi);
2167 old->nh_flags = old_nh_flags;
2168 old->protocol = old_protocol;
2169 oldi->nh_parent = old;
2170 newi->nh_parent = new;
2171 list_for_each_entry_continue_reverse(nhge, &old->grp_list, nh_list) {
2172 struct nexthop *nhp = nhge->nh_parent;
2173
2174 replace_nexthop_single_notify(net, nhp, old, newi, oldi, NULL);
2175 }
2176 call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, old, extack);
2177 return err;
2178}
2179
2180static void __nexthop_replace_notify(struct net *net, struct nexthop *nh,
2181 struct nl_info *info)
2182{
2183 struct fib6_info *f6i;
2184
2185 if (!list_empty(&nh->fi_list)) {
2186 struct fib_info *fi;
2187
2188 /* expectation is a few fib_info per nexthop and then
2189 * a lot of routes per fib_info. So mark the fib_info
2190 * and then walk the fib tables once
2191 */
2192 list_for_each_entry(fi, &nh->fi_list, nh_list)
2193 fi->nh_updated = true;
2194
2195 fib_info_notify_update(net, info);
2196
2197 list_for_each_entry(fi, &nh->fi_list, nh_list)
2198 fi->nh_updated = false;
2199 }
2200
2201 list_for_each_entry(f6i, &nh->f6i_list, nh_list)
2202 ipv6_stub->fib6_rt_update(net, f6i, info);
2203}
2204
2205/* send RTM_NEWROUTE with REPLACE flag set for all FIB entries
2206 * linked to this nexthop and for all groups that the nexthop
2207 * is a member of
2208 */
2209static void nexthop_replace_notify(struct net *net, struct nexthop *nh,
2210 struct nl_info *info)
2211{
2212 struct nh_grp_entry *nhge;
2213
2214 __nexthop_replace_notify(net, nh, info);
2215
2216 list_for_each_entry(nhge, &nh->grp_list, nh_list)
2217 __nexthop_replace_notify(net, nhge->nh_parent, info);
2218}
2219
2220static int replace_nexthop(struct net *net, struct nexthop *old,
2221 struct nexthop *new, const struct nh_config *cfg,
2222 struct netlink_ext_ack *extack)
2223{
2224 bool new_is_reject = false;
2225 struct nh_grp_entry *nhge;
2226 int err;
2227
2228 /* check that existing FIB entries are ok with the
2229 * new nexthop definition
2230 */
2231 err = fib_check_nh_list(old, new, extack);
2232 if (err)
2233 return err;
2234
2235 err = fib6_check_nh_list(old, new, extack);
2236 if (err)
2237 return err;
2238
2239 if (!new->is_group) {
2240 struct nh_info *nhi = rtnl_dereference(new->nh_info);
2241
2242 new_is_reject = nhi->reject_nh;
2243 }
2244
2245 list_for_each_entry(nhge, &old->grp_list, nh_list) {
2246 /* if new nexthop is a blackhole, any groups using this
2247 * nexthop cannot have more than 1 path
2248 */
2249 if (new_is_reject &&
2250 nexthop_num_path(nhge->nh_parent) > 1) {
2251 NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path");
2252 return -EINVAL;
2253 }
2254
2255 err = fib_check_nh_list(nhge->nh_parent, new, extack);
2256 if (err)
2257 return err;
2258
2259 err = fib6_check_nh_list(nhge->nh_parent, new, extack);
2260 if (err)
2261 return err;
2262 }
2263
2264 if (old->is_group)
2265 err = replace_nexthop_grp(net, old, new, cfg, extack);
2266 else
2267 err = replace_nexthop_single(net, old, new, extack);
2268
2269 if (!err) {
2270 nh_rt_cache_flush(net, old, new);
2271
2272 __remove_nexthop(net, new, NULL);
2273 nexthop_put(new);
2274 }
2275
2276 return err;
2277}
2278
2279/* called with rtnl_lock held */
2280static int insert_nexthop(struct net *net, struct nexthop *new_nh,
2281 struct nh_config *cfg, struct netlink_ext_ack *extack)
2282{
2283 struct rb_node **pp, *parent = NULL, *next;
2284 struct rb_root *root = &net->nexthop.rb_root;
2285 bool replace = !!(cfg->nlflags & NLM_F_REPLACE);
2286 bool create = !!(cfg->nlflags & NLM_F_CREATE);
2287 u32 new_id = new_nh->id;
2288 int replace_notify = 0;
2289 int rc = -EEXIST;
2290
2291 pp = &root->rb_node;
2292 while (1) {
2293 struct nexthop *nh;
2294
2295 next = *pp;
2296 if (!next)
2297 break;
2298
2299 parent = next;
2300
2301 nh = rb_entry(parent, struct nexthop, rb_node);
2302 if (new_id < nh->id) {
2303 pp = &next->rb_left;
2304 } else if (new_id > nh->id) {
2305 pp = &next->rb_right;
2306 } else if (replace) {
2307 rc = replace_nexthop(net, nh, new_nh, cfg, extack);
2308 if (!rc) {
2309 new_nh = nh; /* send notification with old nh */
2310 replace_notify = 1;
2311 }
2312 goto out;
2313 } else {
2314 /* id already exists and not a replace */
2315 goto out;
2316 }
2317 }
2318
2319 if (replace && !create) {
2320 NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists");
2321 rc = -ENOENT;
2322 goto out;
2323 }
2324
2325 if (new_nh->is_group) {
2326 struct nh_group *nhg = rtnl_dereference(new_nh->nh_grp);
2327 struct nh_res_table *res_table;
2328
2329 if (nhg->resilient) {
2330 res_table = rtnl_dereference(nhg->res_table);
2331
2332 /* Not passing the number of buckets is OK when
2333 * replacing, but not when creating a new group.
2334 */
2335 if (!cfg->nh_grp_res_has_num_buckets) {
2336 NL_SET_ERR_MSG(extack, "Number of buckets not specified for nexthop group insertion");
2337 rc = -EINVAL;
2338 goto out;
2339 }
2340
2341 nh_res_group_rebalance(nhg, res_table);
2342
2343 /* Do not send bucket notifications, we do full
2344 * notification below.
2345 */
2346 nh_res_table_upkeep(res_table, false, false);
2347 }
2348 }
2349
2350 rb_link_node_rcu(&new_nh->rb_node, parent, pp);
2351 rb_insert_color(&new_nh->rb_node, root);
2352
2353 /* The initial insertion is a full notification for hash-threshold as
2354 * well as resilient groups.
2355 */
2356 rc = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new_nh, extack);
2357 if (rc)
2358 rb_erase(&new_nh->rb_node, &net->nexthop.rb_root);
2359
2360out:
2361 if (!rc) {
2362 nh_base_seq_inc(net);
2363 nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo);
2364 if (replace_notify &&
2365 READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode))
2366 nexthop_replace_notify(net, new_nh, &cfg->nlinfo);
2367 }
2368
2369 return rc;
2370}
2371
2372/* rtnl */
2373/* remove all nexthops tied to a device being deleted */
2374static void nexthop_flush_dev(struct net_device *dev, unsigned long event)
2375{
2376 unsigned int hash = nh_dev_hashfn(dev->ifindex);
2377 struct net *net = dev_net(dev);
2378 struct hlist_head *head = &net->nexthop.devhash[hash];
2379 struct hlist_node *n;
2380 struct nh_info *nhi;
2381
2382 hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
2383 if (nhi->fib_nhc.nhc_dev != dev)
2384 continue;
2385
2386 if (nhi->reject_nh &&
2387 (event == NETDEV_DOWN || event == NETDEV_CHANGE))
2388 continue;
2389
2390 remove_nexthop(net, nhi->nh_parent, NULL);
2391 }
2392}
2393
2394/* rtnl; called when net namespace is deleted */
2395static void flush_all_nexthops(struct net *net)
2396{
2397 struct rb_root *root = &net->nexthop.rb_root;
2398 struct rb_node *node;
2399 struct nexthop *nh;
2400
2401 while ((node = rb_first(root))) {
2402 nh = rb_entry(node, struct nexthop, rb_node);
2403 remove_nexthop(net, nh, NULL);
2404 cond_resched();
2405 }
2406}
2407
2408static struct nexthop *nexthop_create_group(struct net *net,
2409 struct nh_config *cfg)
2410{
2411 struct nlattr *grps_attr = cfg->nh_grp;
2412 struct nexthop_grp *entry = nla_data(grps_attr);
2413 u16 num_nh = nla_len(grps_attr) / sizeof(*entry);
2414 struct nh_group *nhg;
2415 struct nexthop *nh;
2416 int err;
2417 int i;
2418
2419 if (WARN_ON(!num_nh))
2420 return ERR_PTR(-EINVAL);
2421
2422 nh = nexthop_alloc();
2423 if (!nh)
2424 return ERR_PTR(-ENOMEM);
2425
2426 nh->is_group = 1;
2427
2428 nhg = nexthop_grp_alloc(num_nh);
2429 if (!nhg) {
2430 kfree(nh);
2431 return ERR_PTR(-ENOMEM);
2432 }
2433
2434 /* spare group used for removals */
2435 nhg->spare = nexthop_grp_alloc(num_nh);
2436 if (!nhg->spare) {
2437 kfree(nhg);
2438 kfree(nh);
2439 return ERR_PTR(-ENOMEM);
2440 }
2441 nhg->spare->spare = nhg;
2442
2443 for (i = 0; i < nhg->num_nh; ++i) {
2444 struct nexthop *nhe;
2445 struct nh_info *nhi;
2446
2447 nhe = nexthop_find_by_id(net, entry[i].id);
2448 if (!nexthop_get(nhe)) {
2449 err = -ENOENT;
2450 goto out_no_nh;
2451 }
2452
2453 nhi = rtnl_dereference(nhe->nh_info);
2454 if (nhi->family == AF_INET)
2455 nhg->has_v4 = true;
2456
2457 nhg->nh_entries[i].nh = nhe;
2458 nhg->nh_entries[i].weight = entry[i].weight + 1;
2459 list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list);
2460 nhg->nh_entries[i].nh_parent = nh;
2461 }
2462
2463 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) {
2464 nhg->hash_threshold = 1;
2465 nhg->is_multipath = true;
2466 } else if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES) {
2467 struct nh_res_table *res_table;
2468
2469 res_table = nexthop_res_table_alloc(net, cfg->nh_id, cfg);
2470 if (!res_table) {
2471 err = -ENOMEM;
2472 goto out_no_nh;
2473 }
2474
2475 rcu_assign_pointer(nhg->spare->res_table, res_table);
2476 rcu_assign_pointer(nhg->res_table, res_table);
2477 nhg->resilient = true;
2478 nhg->is_multipath = true;
2479 }
2480
2481 WARN_ON_ONCE(nhg->hash_threshold + nhg->resilient != 1);
2482
2483 if (nhg->hash_threshold)
2484 nh_hthr_group_rebalance(nhg);
2485
2486 if (cfg->nh_fdb)
2487 nhg->fdb_nh = 1;
2488
2489 rcu_assign_pointer(nh->nh_grp, nhg);
2490
2491 return nh;
2492
2493out_no_nh:
2494 for (i--; i >= 0; --i) {
2495 list_del(&nhg->nh_entries[i].nh_list);
2496 nexthop_put(nhg->nh_entries[i].nh);
2497 }
2498
2499 kfree(nhg->spare);
2500 kfree(nhg);
2501 kfree(nh);
2502
2503 return ERR_PTR(err);
2504}
2505
2506static int nh_create_ipv4(struct net *net, struct nexthop *nh,
2507 struct nh_info *nhi, struct nh_config *cfg,
2508 struct netlink_ext_ack *extack)
2509{
2510 struct fib_nh *fib_nh = &nhi->fib_nh;
2511 struct fib_config fib_cfg = {
2512 .fc_oif = cfg->nh_ifindex,
2513 .fc_gw4 = cfg->gw.ipv4,
2514 .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0,
2515 .fc_flags = cfg->nh_flags,
2516 .fc_nlinfo = cfg->nlinfo,
2517 .fc_encap = cfg->nh_encap,
2518 .fc_encap_type = cfg->nh_encap_type,
2519 };
2520 u32 tb_id = (cfg->dev ? l3mdev_fib_table(cfg->dev) : RT_TABLE_MAIN);
2521 int err;
2522
2523 err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack);
2524 if (err) {
2525 fib_nh_release(net, fib_nh);
2526 goto out;
2527 }
2528
2529 if (nhi->fdb_nh)
2530 goto out;
2531
2532 /* sets nh_dev if successful */
2533 err = fib_check_nh(net, fib_nh, tb_id, 0, extack);
2534 if (!err) {
2535 nh->nh_flags = fib_nh->fib_nh_flags;
2536 fib_info_update_nhc_saddr(net, &fib_nh->nh_common,
2537 !fib_nh->fib_nh_scope ? 0 : fib_nh->fib_nh_scope - 1);
2538 } else {
2539 fib_nh_release(net, fib_nh);
2540 }
2541out:
2542 return err;
2543}
2544
2545static int nh_create_ipv6(struct net *net, struct nexthop *nh,
2546 struct nh_info *nhi, struct nh_config *cfg,
2547 struct netlink_ext_ack *extack)
2548{
2549 struct fib6_nh *fib6_nh = &nhi->fib6_nh;
2550 struct fib6_config fib6_cfg = {
2551 .fc_table = l3mdev_fib_table(cfg->dev),
2552 .fc_ifindex = cfg->nh_ifindex,
2553 .fc_gateway = cfg->gw.ipv6,
2554 .fc_flags = cfg->nh_flags,
2555 .fc_nlinfo = cfg->nlinfo,
2556 .fc_encap = cfg->nh_encap,
2557 .fc_encap_type = cfg->nh_encap_type,
2558 .fc_is_fdb = cfg->nh_fdb,
2559 };
2560 int err;
2561
2562 if (!ipv6_addr_any(&cfg->gw.ipv6))
2563 fib6_cfg.fc_flags |= RTF_GATEWAY;
2564
2565 /* sets nh_dev if successful */
2566 err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL,
2567 extack);
2568 if (err) {
2569 /* IPv6 is not enabled, don't call fib6_nh_release */
2570 if (err == -EAFNOSUPPORT)
2571 goto out;
2572 ipv6_stub->fib6_nh_release(fib6_nh);
2573 } else {
2574 nh->nh_flags = fib6_nh->fib_nh_flags;
2575 }
2576out:
2577 return err;
2578}
2579
2580static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg,
2581 struct netlink_ext_ack *extack)
2582{
2583 struct nh_info *nhi;
2584 struct nexthop *nh;
2585 int err = 0;
2586
2587 nh = nexthop_alloc();
2588 if (!nh)
2589 return ERR_PTR(-ENOMEM);
2590
2591 nhi = kzalloc(sizeof(*nhi), GFP_KERNEL);
2592 if (!nhi) {
2593 kfree(nh);
2594 return ERR_PTR(-ENOMEM);
2595 }
2596
2597 nh->nh_flags = cfg->nh_flags;
2598 nh->net = net;
2599
2600 nhi->nh_parent = nh;
2601 nhi->family = cfg->nh_family;
2602 nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK;
2603
2604 if (cfg->nh_fdb)
2605 nhi->fdb_nh = 1;
2606
2607 if (cfg->nh_blackhole) {
2608 nhi->reject_nh = 1;
2609 cfg->nh_ifindex = net->loopback_dev->ifindex;
2610 }
2611
2612 switch (cfg->nh_family) {
2613 case AF_INET:
2614 err = nh_create_ipv4(net, nh, nhi, cfg, extack);
2615 break;
2616 case AF_INET6:
2617 err = nh_create_ipv6(net, nh, nhi, cfg, extack);
2618 break;
2619 }
2620
2621 if (err) {
2622 kfree(nhi);
2623 kfree(nh);
2624 return ERR_PTR(err);
2625 }
2626
2627 /* add the entry to the device based hash */
2628 if (!nhi->fdb_nh)
2629 nexthop_devhash_add(net, nhi);
2630
2631 rcu_assign_pointer(nh->nh_info, nhi);
2632
2633 return nh;
2634}
2635
2636/* called with rtnl lock held */
2637static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg,
2638 struct netlink_ext_ack *extack)
2639{
2640 struct nexthop *nh;
2641 int err;
2642
2643 if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) {
2644 NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
2645 return ERR_PTR(-EINVAL);
2646 }
2647
2648 if (!cfg->nh_id) {
2649 cfg->nh_id = nh_find_unused_id(net);
2650 if (!cfg->nh_id) {
2651 NL_SET_ERR_MSG(extack, "No unused id");
2652 return ERR_PTR(-EINVAL);
2653 }
2654 }
2655
2656 if (cfg->nh_grp)
2657 nh = nexthop_create_group(net, cfg);
2658 else
2659 nh = nexthop_create(net, cfg, extack);
2660
2661 if (IS_ERR(nh))
2662 return nh;
2663
2664 refcount_set(&nh->refcnt, 1);
2665 nh->id = cfg->nh_id;
2666 nh->protocol = cfg->nh_protocol;
2667 nh->net = net;
2668
2669 err = insert_nexthop(net, nh, cfg, extack);
2670 if (err) {
2671 __remove_nexthop(net, nh, NULL);
2672 nexthop_put(nh);
2673 nh = ERR_PTR(err);
2674 }
2675
2676 return nh;
2677}
2678
2679static int rtm_nh_get_timer(struct nlattr *attr, unsigned long fallback,
2680 unsigned long *timer_p, bool *has_p,
2681 struct netlink_ext_ack *extack)
2682{
2683 unsigned long timer;
2684 u32 value;
2685
2686 if (!attr) {
2687 *timer_p = fallback;
2688 *has_p = false;
2689 return 0;
2690 }
2691
2692 value = nla_get_u32(attr);
2693 timer = clock_t_to_jiffies(value);
2694 if (timer == ~0UL) {
2695 NL_SET_ERR_MSG(extack, "Timer value too large");
2696 return -EINVAL;
2697 }
2698
2699 *timer_p = timer;
2700 *has_p = true;
2701 return 0;
2702}
2703
2704static int rtm_to_nh_config_grp_res(struct nlattr *res, struct nh_config *cfg,
2705 struct netlink_ext_ack *extack)
2706{
2707 struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_policy_new)] = {};
2708 int err;
2709
2710 if (res) {
2711 err = nla_parse_nested(tb,
2712 ARRAY_SIZE(rtm_nh_res_policy_new) - 1,
2713 res, rtm_nh_res_policy_new, extack);
2714 if (err < 0)
2715 return err;
2716 }
2717
2718 if (tb[NHA_RES_GROUP_BUCKETS]) {
2719 cfg->nh_grp_res_num_buckets =
2720 nla_get_u16(tb[NHA_RES_GROUP_BUCKETS]);
2721 cfg->nh_grp_res_has_num_buckets = true;
2722 if (!cfg->nh_grp_res_num_buckets) {
2723 NL_SET_ERR_MSG(extack, "Number of buckets needs to be non-0");
2724 return -EINVAL;
2725 }
2726 }
2727
2728 err = rtm_nh_get_timer(tb[NHA_RES_GROUP_IDLE_TIMER],
2729 NH_RES_DEFAULT_IDLE_TIMER,
2730 &cfg->nh_grp_res_idle_timer,
2731 &cfg->nh_grp_res_has_idle_timer,
2732 extack);
2733 if (err)
2734 return err;
2735
2736 return rtm_nh_get_timer(tb[NHA_RES_GROUP_UNBALANCED_TIMER],
2737 NH_RES_DEFAULT_UNBALANCED_TIMER,
2738 &cfg->nh_grp_res_unbalanced_timer,
2739 &cfg->nh_grp_res_has_unbalanced_timer,
2740 extack);
2741}
2742
2743static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
2744 struct nlmsghdr *nlh, struct nh_config *cfg,
2745 struct netlink_ext_ack *extack)
2746{
2747 struct nhmsg *nhm = nlmsg_data(nlh);
2748 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_new)];
2749 int err;
2750
2751 err = nlmsg_parse(nlh, sizeof(*nhm), tb,
2752 ARRAY_SIZE(rtm_nh_policy_new) - 1,
2753 rtm_nh_policy_new, extack);
2754 if (err < 0)
2755 return err;
2756
2757 err = -EINVAL;
2758 if (nhm->resvd || nhm->nh_scope) {
2759 NL_SET_ERR_MSG(extack, "Invalid values in ancillary header");
2760 goto out;
2761 }
2762 if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) {
2763 NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header");
2764 goto out;
2765 }
2766
2767 switch (nhm->nh_family) {
2768 case AF_INET:
2769 case AF_INET6:
2770 break;
2771 case AF_UNSPEC:
2772 if (tb[NHA_GROUP])
2773 break;
2774 fallthrough;
2775 default:
2776 NL_SET_ERR_MSG(extack, "Invalid address family");
2777 goto out;
2778 }
2779
2780 memset(cfg, 0, sizeof(*cfg));
2781 cfg->nlflags = nlh->nlmsg_flags;
2782 cfg->nlinfo.portid = NETLINK_CB(skb).portid;
2783 cfg->nlinfo.nlh = nlh;
2784 cfg->nlinfo.nl_net = net;
2785
2786 cfg->nh_family = nhm->nh_family;
2787 cfg->nh_protocol = nhm->nh_protocol;
2788 cfg->nh_flags = nhm->nh_flags;
2789
2790 if (tb[NHA_ID])
2791 cfg->nh_id = nla_get_u32(tb[NHA_ID]);
2792
2793 if (tb[NHA_FDB]) {
2794 if (tb[NHA_OIF] || tb[NHA_BLACKHOLE] ||
2795 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) {
2796 NL_SET_ERR_MSG(extack, "Fdb attribute can not be used with encap, oif or blackhole");
2797 goto out;
2798 }
2799 if (nhm->nh_flags) {
2800 NL_SET_ERR_MSG(extack, "Unsupported nexthop flags in ancillary header");
2801 goto out;
2802 }
2803 cfg->nh_fdb = nla_get_flag(tb[NHA_FDB]);
2804 }
2805
2806 if (tb[NHA_GROUP]) {
2807 if (nhm->nh_family != AF_UNSPEC) {
2808 NL_SET_ERR_MSG(extack, "Invalid family for group");
2809 goto out;
2810 }
2811 cfg->nh_grp = tb[NHA_GROUP];
2812
2813 cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH;
2814 if (tb[NHA_GROUP_TYPE])
2815 cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]);
2816
2817 if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) {
2818 NL_SET_ERR_MSG(extack, "Invalid group type");
2819 goto out;
2820 }
2821 err = nh_check_attr_group(net, tb, ARRAY_SIZE(tb),
2822 cfg->nh_grp_type, extack);
2823 if (err)
2824 goto out;
2825
2826 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES)
2827 err = rtm_to_nh_config_grp_res(tb[NHA_RES_GROUP],
2828 cfg, extack);
2829
2830 /* no other attributes should be set */
2831 goto out;
2832 }
2833
2834 if (tb[NHA_BLACKHOLE]) {
2835 if (tb[NHA_GATEWAY] || tb[NHA_OIF] ||
2836 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE] || tb[NHA_FDB]) {
2837 NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway, oif, encap or fdb");
2838 goto out;
2839 }
2840
2841 cfg->nh_blackhole = 1;
2842 err = 0;
2843 goto out;
2844 }
2845
2846 if (!cfg->nh_fdb && !tb[NHA_OIF]) {
2847 NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole and non-fdb nexthops");
2848 goto out;
2849 }
2850
2851 if (!cfg->nh_fdb && tb[NHA_OIF]) {
2852 cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
2853 if (cfg->nh_ifindex)
2854 cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
2855
2856 if (!cfg->dev) {
2857 NL_SET_ERR_MSG(extack, "Invalid device index");
2858 goto out;
2859 } else if (!(cfg->dev->flags & IFF_UP)) {
2860 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
2861 err = -ENETDOWN;
2862 goto out;
2863 } else if (!netif_carrier_ok(cfg->dev)) {
2864 NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");
2865 err = -ENETDOWN;
2866 goto out;
2867 }
2868 }
2869
2870 err = -EINVAL;
2871 if (tb[NHA_GATEWAY]) {
2872 struct nlattr *gwa = tb[NHA_GATEWAY];
2873
2874 switch (cfg->nh_family) {
2875 case AF_INET:
2876 if (nla_len(gwa) != sizeof(u32)) {
2877 NL_SET_ERR_MSG(extack, "Invalid gateway");
2878 goto out;
2879 }
2880 cfg->gw.ipv4 = nla_get_be32(gwa);
2881 break;
2882 case AF_INET6:
2883 if (nla_len(gwa) != sizeof(struct in6_addr)) {
2884 NL_SET_ERR_MSG(extack, "Invalid gateway");
2885 goto out;
2886 }
2887 cfg->gw.ipv6 = nla_get_in6_addr(gwa);
2888 break;
2889 default:
2890 NL_SET_ERR_MSG(extack,
2891 "Unknown address family for gateway");
2892 goto out;
2893 }
2894 } else {
2895 /* device only nexthop (no gateway) */
2896 if (cfg->nh_flags & RTNH_F_ONLINK) {
2897 NL_SET_ERR_MSG(extack,
2898 "ONLINK flag can not be set for nexthop without a gateway");
2899 goto out;
2900 }
2901 }
2902
2903 if (tb[NHA_ENCAP]) {
2904 cfg->nh_encap = tb[NHA_ENCAP];
2905
2906 if (!tb[NHA_ENCAP_TYPE]) {
2907 NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing");
2908 goto out;
2909 }
2910
2911 cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]);
2912 err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack);
2913 if (err < 0)
2914 goto out;
2915
2916 } else if (tb[NHA_ENCAP_TYPE]) {
2917 NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing");
2918 goto out;
2919 }
2920
2921
2922 err = 0;
2923out:
2924 return err;
2925}
2926
2927/* rtnl */
2928static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
2929 struct netlink_ext_ack *extack)
2930{
2931 struct net *net = sock_net(skb->sk);
2932 struct nh_config cfg;
2933 struct nexthop *nh;
2934 int err;
2935
2936 err = rtm_to_nh_config(net, skb, nlh, &cfg, extack);
2937 if (!err) {
2938 nh = nexthop_add(net, &cfg, extack);
2939 if (IS_ERR(nh))
2940 err = PTR_ERR(nh);
2941 }
2942
2943 return err;
2944}
2945
2946static int __nh_valid_get_del_req(const struct nlmsghdr *nlh,
2947 struct nlattr **tb, u32 *id,
2948 struct netlink_ext_ack *extack)
2949{
2950 struct nhmsg *nhm = nlmsg_data(nlh);
2951
2952 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
2953 NL_SET_ERR_MSG(extack, "Invalid values in header");
2954 return -EINVAL;
2955 }
2956
2957 if (!tb[NHA_ID]) {
2958 NL_SET_ERR_MSG(extack, "Nexthop id is missing");
2959 return -EINVAL;
2960 }
2961
2962 *id = nla_get_u32(tb[NHA_ID]);
2963 if (!(*id)) {
2964 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
2965 return -EINVAL;
2966 }
2967
2968 return 0;
2969}
2970
2971static int nh_valid_get_del_req(const struct nlmsghdr *nlh, u32 *id,
2972 struct netlink_ext_ack *extack)
2973{
2974 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get)];
2975 int err;
2976
2977 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
2978 ARRAY_SIZE(rtm_nh_policy_get) - 1,
2979 rtm_nh_policy_get, extack);
2980 if (err < 0)
2981 return err;
2982
2983 return __nh_valid_get_del_req(nlh, tb, id, extack);
2984}
2985
2986/* rtnl */
2987static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
2988 struct netlink_ext_ack *extack)
2989{
2990 struct net *net = sock_net(skb->sk);
2991 struct nl_info nlinfo = {
2992 .nlh = nlh,
2993 .nl_net = net,
2994 .portid = NETLINK_CB(skb).portid,
2995 };
2996 struct nexthop *nh;
2997 int err;
2998 u32 id;
2999
3000 err = nh_valid_get_del_req(nlh, &id, extack);
3001 if (err)
3002 return err;
3003
3004 nh = nexthop_find_by_id(net, id);
3005 if (!nh)
3006 return -ENOENT;
3007
3008 remove_nexthop(net, nh, &nlinfo);
3009
3010 return 0;
3011}
3012
3013/* rtnl */
3014static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh,
3015 struct netlink_ext_ack *extack)
3016{
3017 struct net *net = sock_net(in_skb->sk);
3018 struct sk_buff *skb = NULL;
3019 struct nexthop *nh;
3020 int err;
3021 u32 id;
3022
3023 err = nh_valid_get_del_req(nlh, &id, extack);
3024 if (err)
3025 return err;
3026
3027 err = -ENOBUFS;
3028 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3029 if (!skb)
3030 goto out;
3031
3032 err = -ENOENT;
3033 nh = nexthop_find_by_id(net, id);
3034 if (!nh)
3035 goto errout_free;
3036
3037 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid,
3038 nlh->nlmsg_seq, 0);
3039 if (err < 0) {
3040 WARN_ON(err == -EMSGSIZE);
3041 goto errout_free;
3042 }
3043
3044 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3045out:
3046 return err;
3047errout_free:
3048 kfree_skb(skb);
3049 goto out;
3050}
3051
3052struct nh_dump_filter {
3053 u32 nh_id;
3054 int dev_idx;
3055 int master_idx;
3056 bool group_filter;
3057 bool fdb_filter;
3058 u32 res_bucket_nh_id;
3059};
3060
3061static bool nh_dump_filtered(struct nexthop *nh,
3062 struct nh_dump_filter *filter, u8 family)
3063{
3064 const struct net_device *dev;
3065 const struct nh_info *nhi;
3066
3067 if (filter->group_filter && !nh->is_group)
3068 return true;
3069
3070 if (!filter->dev_idx && !filter->master_idx && !family)
3071 return false;
3072
3073 if (nh->is_group)
3074 return true;
3075
3076 nhi = rtnl_dereference(nh->nh_info);
3077 if (family && nhi->family != family)
3078 return true;
3079
3080 dev = nhi->fib_nhc.nhc_dev;
3081 if (filter->dev_idx && (!dev || dev->ifindex != filter->dev_idx))
3082 return true;
3083
3084 if (filter->master_idx) {
3085 struct net_device *master;
3086
3087 if (!dev)
3088 return true;
3089
3090 master = netdev_master_upper_dev_get((struct net_device *)dev);
3091 if (!master || master->ifindex != filter->master_idx)
3092 return true;
3093 }
3094
3095 return false;
3096}
3097
3098static int __nh_valid_dump_req(const struct nlmsghdr *nlh, struct nlattr **tb,
3099 struct nh_dump_filter *filter,
3100 struct netlink_ext_ack *extack)
3101{
3102 struct nhmsg *nhm;
3103 u32 idx;
3104
3105 if (tb[NHA_OIF]) {
3106 idx = nla_get_u32(tb[NHA_OIF]);
3107 if (idx > INT_MAX) {
3108 NL_SET_ERR_MSG(extack, "Invalid device index");
3109 return -EINVAL;
3110 }
3111 filter->dev_idx = idx;
3112 }
3113 if (tb[NHA_MASTER]) {
3114 idx = nla_get_u32(tb[NHA_MASTER]);
3115 if (idx > INT_MAX) {
3116 NL_SET_ERR_MSG(extack, "Invalid master device index");
3117 return -EINVAL;
3118 }
3119 filter->master_idx = idx;
3120 }
3121 filter->group_filter = nla_get_flag(tb[NHA_GROUPS]);
3122 filter->fdb_filter = nla_get_flag(tb[NHA_FDB]);
3123
3124 nhm = nlmsg_data(nlh);
3125 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
3126 NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request");
3127 return -EINVAL;
3128 }
3129
3130 return 0;
3131}
3132
3133static int nh_valid_dump_req(const struct nlmsghdr *nlh,
3134 struct nh_dump_filter *filter,
3135 struct netlink_callback *cb)
3136{
3137 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump)];
3138 int err;
3139
3140 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
3141 ARRAY_SIZE(rtm_nh_policy_dump) - 1,
3142 rtm_nh_policy_dump, cb->extack);
3143 if (err < 0)
3144 return err;
3145
3146 return __nh_valid_dump_req(nlh, tb, filter, cb->extack);
3147}
3148
3149struct rtm_dump_nh_ctx {
3150 u32 idx;
3151};
3152
3153static struct rtm_dump_nh_ctx *
3154rtm_dump_nh_ctx(struct netlink_callback *cb)
3155{
3156 struct rtm_dump_nh_ctx *ctx = (void *)cb->ctx;
3157
3158 BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
3159 return ctx;
3160}
3161
3162static int rtm_dump_walk_nexthops(struct sk_buff *skb,
3163 struct netlink_callback *cb,
3164 struct rb_root *root,
3165 struct rtm_dump_nh_ctx *ctx,
3166 int (*nh_cb)(struct sk_buff *skb,
3167 struct netlink_callback *cb,
3168 struct nexthop *nh, void *data),
3169 void *data)
3170{
3171 struct rb_node *node;
3172 int s_idx;
3173 int err;
3174
3175 s_idx = ctx->idx;
3176 for (node = rb_first(root); node; node = rb_next(node)) {
3177 struct nexthop *nh;
3178
3179 nh = rb_entry(node, struct nexthop, rb_node);
3180 if (nh->id < s_idx)
3181 continue;
3182
3183 ctx->idx = nh->id;
3184 err = nh_cb(skb, cb, nh, data);
3185 if (err)
3186 return err;
3187 }
3188
3189 ctx->idx++;
3190 return 0;
3191}
3192
3193static int rtm_dump_nexthop_cb(struct sk_buff *skb, struct netlink_callback *cb,
3194 struct nexthop *nh, void *data)
3195{
3196 struct nhmsg *nhm = nlmsg_data(cb->nlh);
3197 struct nh_dump_filter *filter = data;
3198
3199 if (nh_dump_filtered(nh, filter, nhm->nh_family))
3200 return 0;
3201
3202 return nh_fill_node(skb, nh, RTM_NEWNEXTHOP,
3203 NETLINK_CB(cb->skb).portid,
3204 cb->nlh->nlmsg_seq, NLM_F_MULTI);
3205}
3206
3207/* rtnl */
3208static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
3209{
3210 struct rtm_dump_nh_ctx *ctx = rtm_dump_nh_ctx(cb);
3211 struct net *net = sock_net(skb->sk);
3212 struct rb_root *root = &net->nexthop.rb_root;
3213 struct nh_dump_filter filter = {};
3214 int err;
3215
3216 err = nh_valid_dump_req(cb->nlh, &filter, cb);
3217 if (err < 0)
3218 return err;
3219
3220 err = rtm_dump_walk_nexthops(skb, cb, root, ctx,
3221 &rtm_dump_nexthop_cb, &filter);
3222 if (err < 0) {
3223 if (likely(skb->len))
3224 goto out;
3225 goto out_err;
3226 }
3227
3228out:
3229 err = skb->len;
3230out_err:
3231 cb->seq = net->nexthop.seq;
3232 nl_dump_check_consistent(cb, nlmsg_hdr(skb));
3233 return err;
3234}
3235
3236static struct nexthop *
3237nexthop_find_group_resilient(struct net *net, u32 id,
3238 struct netlink_ext_ack *extack)
3239{
3240 struct nh_group *nhg;
3241 struct nexthop *nh;
3242
3243 nh = nexthop_find_by_id(net, id);
3244 if (!nh)
3245 return ERR_PTR(-ENOENT);
3246
3247 if (!nh->is_group) {
3248 NL_SET_ERR_MSG(extack, "Not a nexthop group");
3249 return ERR_PTR(-EINVAL);
3250 }
3251
3252 nhg = rtnl_dereference(nh->nh_grp);
3253 if (!nhg->resilient) {
3254 NL_SET_ERR_MSG(extack, "Nexthop group not of type resilient");
3255 return ERR_PTR(-EINVAL);
3256 }
3257
3258 return nh;
3259}
3260
3261static int nh_valid_dump_nhid(struct nlattr *attr, u32 *nh_id_p,
3262 struct netlink_ext_ack *extack)
3263{
3264 u32 idx;
3265
3266 if (attr) {
3267 idx = nla_get_u32(attr);
3268 if (!idx) {
3269 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
3270 return -EINVAL;
3271 }
3272 *nh_id_p = idx;
3273 } else {
3274 *nh_id_p = 0;
3275 }
3276
3277 return 0;
3278}
3279
3280static int nh_valid_dump_bucket_req(const struct nlmsghdr *nlh,
3281 struct nh_dump_filter *filter,
3282 struct netlink_callback *cb)
3283{
3284 struct nlattr *res_tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_dump)];
3285 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump_bucket)];
3286 int err;
3287
3288 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
3289 ARRAY_SIZE(rtm_nh_policy_dump_bucket) - 1,
3290 rtm_nh_policy_dump_bucket, NULL);
3291 if (err < 0)
3292 return err;
3293
3294 err = nh_valid_dump_nhid(tb[NHA_ID], &filter->nh_id, cb->extack);
3295 if (err)
3296 return err;
3297
3298 if (tb[NHA_RES_BUCKET]) {
3299 size_t max = ARRAY_SIZE(rtm_nh_res_bucket_policy_dump) - 1;
3300
3301 err = nla_parse_nested(res_tb, max,
3302 tb[NHA_RES_BUCKET],
3303 rtm_nh_res_bucket_policy_dump,
3304 cb->extack);
3305 if (err < 0)
3306 return err;
3307
3308 err = nh_valid_dump_nhid(res_tb[NHA_RES_BUCKET_NH_ID],
3309 &filter->res_bucket_nh_id,
3310 cb->extack);
3311 if (err)
3312 return err;
3313 }
3314
3315 return __nh_valid_dump_req(nlh, tb, filter, cb->extack);
3316}
3317
3318struct rtm_dump_res_bucket_ctx {
3319 struct rtm_dump_nh_ctx nh;
3320 u16 bucket_index;
3321 u32 done_nh_idx; /* 1 + the index of the last fully processed NH. */
3322};
3323
3324static struct rtm_dump_res_bucket_ctx *
3325rtm_dump_res_bucket_ctx(struct netlink_callback *cb)
3326{
3327 struct rtm_dump_res_bucket_ctx *ctx = (void *)cb->ctx;
3328
3329 BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
3330 return ctx;
3331}
3332
3333struct rtm_dump_nexthop_bucket_data {
3334 struct rtm_dump_res_bucket_ctx *ctx;
3335 struct nh_dump_filter filter;
3336};
3337
3338static int rtm_dump_nexthop_bucket_nh(struct sk_buff *skb,
3339 struct netlink_callback *cb,
3340 struct nexthop *nh,
3341 struct rtm_dump_nexthop_bucket_data *dd)
3342{
3343 u32 portid = NETLINK_CB(cb->skb).portid;
3344 struct nhmsg *nhm = nlmsg_data(cb->nlh);
3345 struct nh_res_table *res_table;
3346 struct nh_group *nhg;
3347 u16 bucket_index;
3348 int err;
3349
3350 if (dd->ctx->nh.idx < dd->ctx->done_nh_idx)
3351 return 0;
3352
3353 nhg = rtnl_dereference(nh->nh_grp);
3354 res_table = rtnl_dereference(nhg->res_table);
3355 for (bucket_index = dd->ctx->bucket_index;
3356 bucket_index < res_table->num_nh_buckets;
3357 bucket_index++) {
3358 struct nh_res_bucket *bucket;
3359 struct nh_grp_entry *nhge;
3360
3361 bucket = &res_table->nh_buckets[bucket_index];
3362 nhge = rtnl_dereference(bucket->nh_entry);
3363 if (nh_dump_filtered(nhge->nh, &dd->filter, nhm->nh_family))
3364 continue;
3365
3366 if (dd->filter.res_bucket_nh_id &&
3367 dd->filter.res_bucket_nh_id != nhge->nh->id)
3368 continue;
3369
3370 err = nh_fill_res_bucket(skb, nh, bucket, bucket_index,
3371 RTM_NEWNEXTHOPBUCKET, portid,
3372 cb->nlh->nlmsg_seq, NLM_F_MULTI,
3373 cb->extack);
3374 if (err < 0) {
3375 if (likely(skb->len))
3376 goto out;
3377 goto out_err;
3378 }
3379 }
3380
3381 dd->ctx->done_nh_idx = dd->ctx->nh.idx + 1;
3382 bucket_index = 0;
3383
3384out:
3385 err = skb->len;
3386out_err:
3387 dd->ctx->bucket_index = bucket_index;
3388 return err;
3389}
3390
3391static int rtm_dump_nexthop_bucket_cb(struct sk_buff *skb,
3392 struct netlink_callback *cb,
3393 struct nexthop *nh, void *data)
3394{
3395 struct rtm_dump_nexthop_bucket_data *dd = data;
3396 struct nh_group *nhg;
3397
3398 if (!nh->is_group)
3399 return 0;
3400
3401 nhg = rtnl_dereference(nh->nh_grp);
3402 if (!nhg->resilient)
3403 return 0;
3404
3405 return rtm_dump_nexthop_bucket_nh(skb, cb, nh, dd);
3406}
3407
3408/* rtnl */
3409static int rtm_dump_nexthop_bucket(struct sk_buff *skb,
3410 struct netlink_callback *cb)
3411{
3412 struct rtm_dump_res_bucket_ctx *ctx = rtm_dump_res_bucket_ctx(cb);
3413 struct rtm_dump_nexthop_bucket_data dd = { .ctx = ctx };
3414 struct net *net = sock_net(skb->sk);
3415 struct nexthop *nh;
3416 int err;
3417
3418 err = nh_valid_dump_bucket_req(cb->nlh, &dd.filter, cb);
3419 if (err)
3420 return err;
3421
3422 if (dd.filter.nh_id) {
3423 nh = nexthop_find_group_resilient(net, dd.filter.nh_id,
3424 cb->extack);
3425 if (IS_ERR(nh))
3426 return PTR_ERR(nh);
3427 err = rtm_dump_nexthop_bucket_nh(skb, cb, nh, &dd);
3428 } else {
3429 struct rb_root *root = &net->nexthop.rb_root;
3430
3431 err = rtm_dump_walk_nexthops(skb, cb, root, &ctx->nh,
3432 &rtm_dump_nexthop_bucket_cb, &dd);
3433 }
3434
3435 if (err < 0) {
3436 if (likely(skb->len))
3437 goto out;
3438 goto out_err;
3439 }
3440
3441out:
3442 err = skb->len;
3443out_err:
3444 cb->seq = net->nexthop.seq;
3445 nl_dump_check_consistent(cb, nlmsg_hdr(skb));
3446 return err;
3447}
3448
3449static int nh_valid_get_bucket_req_res_bucket(struct nlattr *res,
3450 u16 *bucket_index,
3451 struct netlink_ext_ack *extack)
3452{
3453 struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_get)];
3454 int err;
3455
3456 err = nla_parse_nested(tb, ARRAY_SIZE(rtm_nh_res_bucket_policy_get) - 1,
3457 res, rtm_nh_res_bucket_policy_get, extack);
3458 if (err < 0)
3459 return err;
3460
3461 if (!tb[NHA_RES_BUCKET_INDEX]) {
3462 NL_SET_ERR_MSG(extack, "Bucket index is missing");
3463 return -EINVAL;
3464 }
3465
3466 *bucket_index = nla_get_u16(tb[NHA_RES_BUCKET_INDEX]);
3467 return 0;
3468}
3469
3470static int nh_valid_get_bucket_req(const struct nlmsghdr *nlh,
3471 u32 *id, u16 *bucket_index,
3472 struct netlink_ext_ack *extack)
3473{
3474 struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get_bucket)];
3475 int err;
3476
3477 err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
3478 ARRAY_SIZE(rtm_nh_policy_get_bucket) - 1,
3479 rtm_nh_policy_get_bucket, extack);
3480 if (err < 0)
3481 return err;
3482
3483 err = __nh_valid_get_del_req(nlh, tb, id, extack);
3484 if (err)
3485 return err;
3486
3487 if (!tb[NHA_RES_BUCKET]) {
3488 NL_SET_ERR_MSG(extack, "Bucket information is missing");
3489 return -EINVAL;
3490 }
3491
3492 err = nh_valid_get_bucket_req_res_bucket(tb[NHA_RES_BUCKET],
3493 bucket_index, extack);
3494 if (err)
3495 return err;
3496
3497 return 0;
3498}
3499
3500/* rtnl */
3501static int rtm_get_nexthop_bucket(struct sk_buff *in_skb, struct nlmsghdr *nlh,
3502 struct netlink_ext_ack *extack)
3503{
3504 struct net *net = sock_net(in_skb->sk);
3505 struct nh_res_table *res_table;
3506 struct sk_buff *skb = NULL;
3507 struct nh_group *nhg;
3508 struct nexthop *nh;
3509 u16 bucket_index;
3510 int err;
3511 u32 id;
3512
3513 err = nh_valid_get_bucket_req(nlh, &id, &bucket_index, extack);
3514 if (err)
3515 return err;
3516
3517 nh = nexthop_find_group_resilient(net, id, extack);
3518 if (IS_ERR(nh))
3519 return PTR_ERR(nh);
3520
3521 nhg = rtnl_dereference(nh->nh_grp);
3522 res_table = rtnl_dereference(nhg->res_table);
3523 if (bucket_index >= res_table->num_nh_buckets) {
3524 NL_SET_ERR_MSG(extack, "Bucket index out of bounds");
3525 return -ENOENT;
3526 }
3527
3528 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3529 if (!skb)
3530 return -ENOBUFS;
3531
3532 err = nh_fill_res_bucket(skb, nh, &res_table->nh_buckets[bucket_index],
3533 bucket_index, RTM_NEWNEXTHOPBUCKET,
3534 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
3535 0, extack);
3536 if (err < 0) {
3537 WARN_ON(err == -EMSGSIZE);
3538 goto errout_free;
3539 }
3540
3541 return rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3542
3543errout_free:
3544 kfree_skb(skb);
3545 return err;
3546}
3547
3548static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu)
3549{
3550 unsigned int hash = nh_dev_hashfn(dev->ifindex);
3551 struct net *net = dev_net(dev);
3552 struct hlist_head *head = &net->nexthop.devhash[hash];
3553 struct hlist_node *n;
3554 struct nh_info *nhi;
3555
3556 hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
3557 if (nhi->fib_nhc.nhc_dev == dev) {
3558 if (nhi->family == AF_INET)
3559 fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu,
3560 orig_mtu);
3561 }
3562 }
3563}
3564
3565/* rtnl */
3566static int nh_netdev_event(struct notifier_block *this,
3567 unsigned long event, void *ptr)
3568{
3569 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3570 struct netdev_notifier_info_ext *info_ext;
3571
3572 switch (event) {
3573 case NETDEV_DOWN:
3574 case NETDEV_UNREGISTER:
3575 nexthop_flush_dev(dev, event);
3576 break;
3577 case NETDEV_CHANGE:
3578 if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP)))
3579 nexthop_flush_dev(dev, event);
3580 break;
3581 case NETDEV_CHANGEMTU:
3582 info_ext = ptr;
3583 nexthop_sync_mtu(dev, info_ext->ext.mtu);
3584 rt_cache_flush(dev_net(dev));
3585 break;
3586 }
3587 return NOTIFY_DONE;
3588}
3589
3590static struct notifier_block nh_netdev_notifier = {
3591 .notifier_call = nh_netdev_event,
3592};
3593
3594static int nexthops_dump(struct net *net, struct notifier_block *nb,
3595 enum nexthop_event_type event_type,
3596 struct netlink_ext_ack *extack)
3597{
3598 struct rb_root *root = &net->nexthop.rb_root;
3599 struct rb_node *node;
3600 int err = 0;
3601
3602 for (node = rb_first(root); node; node = rb_next(node)) {
3603 struct nexthop *nh;
3604
3605 nh = rb_entry(node, struct nexthop, rb_node);
3606 err = call_nexthop_notifier(nb, net, event_type, nh, extack);
3607 if (err)
3608 break;
3609 }
3610
3611 return err;
3612}
3613
3614int register_nexthop_notifier(struct net *net, struct notifier_block *nb,
3615 struct netlink_ext_ack *extack)
3616{
3617 int err;
3618
3619 rtnl_lock();
3620 err = nexthops_dump(net, nb, NEXTHOP_EVENT_REPLACE, extack);
3621 if (err)
3622 goto unlock;
3623 err = blocking_notifier_chain_register(&net->nexthop.notifier_chain,
3624 nb);
3625unlock:
3626 rtnl_unlock();
3627 return err;
3628}
3629EXPORT_SYMBOL(register_nexthop_notifier);
3630
3631int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb)
3632{
3633 int err;
3634
3635 rtnl_lock();
3636 err = blocking_notifier_chain_unregister(&net->nexthop.notifier_chain,
3637 nb);
3638 if (err)
3639 goto unlock;
3640 nexthops_dump(net, nb, NEXTHOP_EVENT_DEL, NULL);
3641unlock:
3642 rtnl_unlock();
3643 return err;
3644}
3645EXPORT_SYMBOL(unregister_nexthop_notifier);
3646
3647void nexthop_set_hw_flags(struct net *net, u32 id, bool offload, bool trap)
3648{
3649 struct nexthop *nexthop;
3650
3651 rcu_read_lock();
3652
3653 nexthop = nexthop_find_by_id(net, id);
3654 if (!nexthop)
3655 goto out;
3656
3657 nexthop->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP);
3658 if (offload)
3659 nexthop->nh_flags |= RTNH_F_OFFLOAD;
3660 if (trap)
3661 nexthop->nh_flags |= RTNH_F_TRAP;
3662
3663out:
3664 rcu_read_unlock();
3665}
3666EXPORT_SYMBOL(nexthop_set_hw_flags);
3667
3668void nexthop_bucket_set_hw_flags(struct net *net, u32 id, u16 bucket_index,
3669 bool offload, bool trap)
3670{
3671 struct nh_res_table *res_table;
3672 struct nh_res_bucket *bucket;
3673 struct nexthop *nexthop;
3674 struct nh_group *nhg;
3675
3676 rcu_read_lock();
3677
3678 nexthop = nexthop_find_by_id(net, id);
3679 if (!nexthop || !nexthop->is_group)
3680 goto out;
3681
3682 nhg = rcu_dereference(nexthop->nh_grp);
3683 if (!nhg->resilient)
3684 goto out;
3685
3686 if (bucket_index >= nhg->res_table->num_nh_buckets)
3687 goto out;
3688
3689 res_table = rcu_dereference(nhg->res_table);
3690 bucket = &res_table->nh_buckets[bucket_index];
3691 bucket->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP);
3692 if (offload)
3693 bucket->nh_flags |= RTNH_F_OFFLOAD;
3694 if (trap)
3695 bucket->nh_flags |= RTNH_F_TRAP;
3696
3697out:
3698 rcu_read_unlock();
3699}
3700EXPORT_SYMBOL(nexthop_bucket_set_hw_flags);
3701
3702void nexthop_res_grp_activity_update(struct net *net, u32 id, u16 num_buckets,
3703 unsigned long *activity)
3704{
3705 struct nh_res_table *res_table;
3706 struct nexthop *nexthop;
3707 struct nh_group *nhg;
3708 u16 i;
3709
3710 rcu_read_lock();
3711
3712 nexthop = nexthop_find_by_id(net, id);
3713 if (!nexthop || !nexthop->is_group)
3714 goto out;
3715
3716 nhg = rcu_dereference(nexthop->nh_grp);
3717 if (!nhg->resilient)
3718 goto out;
3719
3720 /* Instead of silently ignoring some buckets, demand that the sizes
3721 * be the same.
3722 */
3723 res_table = rcu_dereference(nhg->res_table);
3724 if (num_buckets != res_table->num_nh_buckets)
3725 goto out;
3726
3727 for (i = 0; i < num_buckets; i++) {
3728 if (test_bit(i, activity))
3729 nh_res_bucket_set_busy(&res_table->nh_buckets[i]);
3730 }
3731
3732out:
3733 rcu_read_unlock();
3734}
3735EXPORT_SYMBOL(nexthop_res_grp_activity_update);
3736
3737static void __net_exit nexthop_net_exit_batch(struct list_head *net_list)
3738{
3739 struct net *net;
3740
3741 rtnl_lock();
3742 list_for_each_entry(net, net_list, exit_list) {
3743 flush_all_nexthops(net);
3744 kfree(net->nexthop.devhash);
3745 }
3746 rtnl_unlock();
3747}
3748
3749static int __net_init nexthop_net_init(struct net *net)
3750{
3751 size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE;
3752
3753 net->nexthop.rb_root = RB_ROOT;
3754 net->nexthop.devhash = kzalloc(sz, GFP_KERNEL);
3755 if (!net->nexthop.devhash)
3756 return -ENOMEM;
3757 BLOCKING_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain);
3758
3759 return 0;
3760}
3761
3762static struct pernet_operations nexthop_net_ops = {
3763 .init = nexthop_net_init,
3764 .exit_batch = nexthop_net_exit_batch,
3765};
3766
3767static int __init nexthop_init(void)
3768{
3769 register_pernet_subsys(&nexthop_net_ops);
3770
3771 register_netdevice_notifier(&nh_netdev_notifier);
3772
3773 rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
3774 rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0);
3775 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop,
3776 rtm_dump_nexthop, 0);
3777
3778 rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
3779 rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
3780
3781 rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
3782 rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
3783
3784 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOPBUCKET, rtm_get_nexthop_bucket,
3785 rtm_dump_nexthop_bucket, 0);
3786
3787 return 0;
3788}
3789subsys_initcall(nexthop_init);