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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);