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gpio: rcar: Fix runtime PM imbalance on error
[linux/fpc-iii.git] / net / ipv4 / nexthop.c
blobfdfca534d0942016a61174ab1e99fc056d6bc65c
1 // SPDX-License-Identifier: GPL-2.0
2 /* Generic nexthop implementation
3 *
4 * Copyright (c) 2017-19 Cumulus Networks
5 * Copyright (c) 2017-19 David Ahern <dsa@cumulusnetworks.com>
6 */
7
8 #include <linux/nexthop.h>
9 #include <linux/rtnetlink.h>
10 #include <linux/slab.h>
11 #include <net/arp.h>
12 #include <net/ipv6_stubs.h>
13 #include <net/lwtunnel.h>
14 #include <net/ndisc.h>
15 #include <net/nexthop.h>
16 #include <net/route.h>
17 #include <net/sock.h>
18
19 static 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
25 static 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 };
37
38 static unsigned int nh_dev_hashfn(unsigned int val)
39 {
40 unsigned int mask = NH_DEV_HASHSIZE - 1;
41
42 return (val ^
43 (val >> NH_DEV_HASHBITS) ^
44 (val >> (NH_DEV_HASHBITS * 2))) & mask;
45 }
46
47 static void nexthop_devhash_add(struct net *net, struct nh_info *nhi)
48 {
49 struct net_device *dev = nhi->fib_nhc.nhc_dev;
50 struct hlist_head *head;
51 unsigned int hash;
52
53 WARN_ON(!dev);
54
55 hash = nh_dev_hashfn(dev->ifindex);
56 head = &net->nexthop.devhash[hash];
57 hlist_add_head(&nhi->dev_hash, head);
58 }
59
60 static void nexthop_free_mpath(struct nexthop *nh)
61 {
62 struct nh_group *nhg;
63 int i;
64
65 nhg = rcu_dereference_raw(nh->nh_grp);
66 for (i = 0; i < nhg->num_nh; ++i)
67 WARN_ON(nhg->nh_entries[i].nh);
68
69 kfree(nhg);
70 }
71
72 static void nexthop_free_single(struct nexthop *nh)
73 {
74 struct nh_info *nhi;
75
76 nhi = rcu_dereference_raw(nh->nh_info);
77 switch (nhi->family) {
78 case AF_INET:
79 fib_nh_release(nh->net, &nhi->fib_nh);
80 break;
81 case AF_INET6:
82 ipv6_stub->fib6_nh_release(&nhi->fib6_nh);
83 break;
84 }
85 kfree(nhi);
86 }
87
88 void nexthop_free_rcu(struct rcu_head *head)
89 {
90 struct nexthop *nh = container_of(head, struct nexthop, rcu);
91
92 if (nh->is_group)
93 nexthop_free_mpath(nh);
94 else
95 nexthop_free_single(nh);
96
97 kfree(nh);
98 }
99 EXPORT_SYMBOL_GPL(nexthop_free_rcu);
100
101 static struct nexthop *nexthop_alloc(void)
102 {
103 struct nexthop *nh;
104
105 nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL);
106 if (nh) {
107 INIT_LIST_HEAD(&nh->fi_list);
108 INIT_LIST_HEAD(&nh->f6i_list);
109 INIT_LIST_HEAD(&nh->grp_list);
110 }
111 return nh;
112 }
113
114 static struct nh_group *nexthop_grp_alloc(u16 num_nh)
115 {
116 size_t sz = offsetof(struct nexthop, nh_grp)
117 + sizeof(struct nh_group)
118 + sizeof(struct nh_grp_entry) * num_nh;
119 struct nh_group *nhg;
120
121 nhg = kzalloc(sz, GFP_KERNEL);
122 if (nhg)
123 nhg->num_nh = num_nh;
124
125 return nhg;
126 }
127
128 static void nh_base_seq_inc(struct net *net)
129 {
130 while (++net->nexthop.seq == 0)
131 ;
132 }
133
134 /* no reference taken; rcu lock or rtnl must be held */
135 struct nexthop *nexthop_find_by_id(struct net *net, u32 id)
136 {
137 struct rb_node **pp, *parent = NULL, *next;
138
139 pp = &net->nexthop.rb_root.rb_node;
140 while (1) {
141 struct nexthop *nh;
142
143 next = rcu_dereference_raw(*pp);
144 if (!next)
145 break;
146 parent = next;
147
148 nh = rb_entry(parent, struct nexthop, rb_node);
149 if (id < nh->id)
150 pp = &next->rb_left;
151 else if (id > nh->id)
152 pp = &next->rb_right;
153 else
154 return nh;
155 }
156 return NULL;
157 }
158 EXPORT_SYMBOL_GPL(nexthop_find_by_id);
159
160 /* used for auto id allocation; called with rtnl held */
161 static u32 nh_find_unused_id(struct net *net)
162 {
163 u32 id_start = net->nexthop.last_id_allocated;
164
165 while (1) {
166 net->nexthop.last_id_allocated++;
167 if (net->nexthop.last_id_allocated == id_start)
168 break;
169
170 if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated))
171 return net->nexthop.last_id_allocated;
172 }
173 return 0;
174 }
175
176 static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg)
177 {
178 struct nexthop_grp *p;
179 size_t len = nhg->num_nh * sizeof(*p);
180 struct nlattr *nla;
181 u16 group_type = 0;
182 int i;
183
184 if (nhg->mpath)
185 group_type = NEXTHOP_GRP_TYPE_MPATH;
186
187 if (nla_put_u16(skb, NHA_GROUP_TYPE, group_type))
188 goto nla_put_failure;
189
190 nla = nla_reserve(skb, NHA_GROUP, len);
191 if (!nla)
192 goto nla_put_failure;
193
194 p = nla_data(nla);
195 for (i = 0; i < nhg->num_nh; ++i) {
196 p->id = nhg->nh_entries[i].nh->id;
197 p->weight = nhg->nh_entries[i].weight - 1;
198 p += 1;
199 }
200
201 return 0;
202
203 nla_put_failure:
204 return -EMSGSIZE;
205 }
206
207 static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh,
208 int event, u32 portid, u32 seq, unsigned int nlflags)
209 {
210 struct fib6_nh *fib6_nh;
211 struct fib_nh *fib_nh;
212 struct nlmsghdr *nlh;
213 struct nh_info *nhi;
214 struct nhmsg *nhm;
215
216 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
217 if (!nlh)
218 return -EMSGSIZE;
219
220 nhm = nlmsg_data(nlh);
221 nhm->nh_family = AF_UNSPEC;
222 nhm->nh_flags = nh->nh_flags;
223 nhm->nh_protocol = nh->protocol;
224 nhm->nh_scope = 0;
225 nhm->resvd = 0;
226
227 if (nla_put_u32(skb, NHA_ID, nh->id))
228 goto nla_put_failure;
229
230 if (nh->is_group) {
231 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
232
233 if (nla_put_nh_group(skb, nhg))
234 goto nla_put_failure;
235 goto out;
236 }
237
238 nhi = rtnl_dereference(nh->nh_info);
239 nhm->nh_family = nhi->family;
240 if (nhi->reject_nh) {
241 if (nla_put_flag(skb, NHA_BLACKHOLE))
242 goto nla_put_failure;
243 goto out;
244 } else {
245 const struct net_device *dev;
246
247 dev = nhi->fib_nhc.nhc_dev;
248 if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex))
249 goto nla_put_failure;
250 }
251
252 nhm->nh_scope = nhi->fib_nhc.nhc_scope;
253 switch (nhi->family) {
254 case AF_INET:
255 fib_nh = &nhi->fib_nh;
256 if (fib_nh->fib_nh_gw_family &&
257 nla_put_u32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4))
258 goto nla_put_failure;
259 break;
260
261 case AF_INET6:
262 fib6_nh = &nhi->fib6_nh;
263 if (fib6_nh->fib_nh_gw_family &&
264 nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->fib_nh_gw6))
265 goto nla_put_failure;
266 break;
267 }
268
269 if (nhi->fib_nhc.nhc_lwtstate &&
270 lwtunnel_fill_encap(skb, nhi->fib_nhc.nhc_lwtstate,
271 NHA_ENCAP, NHA_ENCAP_TYPE) < 0)
272 goto nla_put_failure;
273
274 out:
275 nlmsg_end(skb, nlh);
276 return 0;
277
278 nla_put_failure:
279 return -EMSGSIZE;
280 }
281
282 static size_t nh_nlmsg_size_grp(struct nexthop *nh)
283 {
284 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
285 size_t sz = sizeof(struct nexthop_grp) * nhg->num_nh;
286
287 return nla_total_size(sz) +
288 nla_total_size(2); /* NHA_GROUP_TYPE */
289 }
290
291 static size_t nh_nlmsg_size_single(struct nexthop *nh)
292 {
293 struct nh_info *nhi = rtnl_dereference(nh->nh_info);
294 size_t sz;
295
296 /* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE
297 * are mutually exclusive
298 */
299 sz = nla_total_size(4); /* NHA_OIF */
300
301 switch (nhi->family) {
302 case AF_INET:
303 if (nhi->fib_nh.fib_nh_gw_family)
304 sz += nla_total_size(4); /* NHA_GATEWAY */
305 break;
306
307 case AF_INET6:
308 /* NHA_GATEWAY */
309 if (nhi->fib6_nh.fib_nh_gw_family)
310 sz += nla_total_size(sizeof(const struct in6_addr));
311 break;
312 }
313
314 if (nhi->fib_nhc.nhc_lwtstate) {
315 sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate);
316 sz += nla_total_size(2); /* NHA_ENCAP_TYPE */
317 }
318
319 return sz;
320 }
321
322 static size_t nh_nlmsg_size(struct nexthop *nh)
323 {
324 size_t sz = NLMSG_ALIGN(sizeof(struct nhmsg));
325
326 sz += nla_total_size(4); /* NHA_ID */
327
328 if (nh->is_group)
329 sz += nh_nlmsg_size_grp(nh);
330 else
331 sz += nh_nlmsg_size_single(nh);
332
333 return sz;
334 }
335
336 static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info)
337 {
338 unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0;
339 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
340 struct sk_buff *skb;
341 int err = -ENOBUFS;
342
343 skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any());
344 if (!skb)
345 goto errout;
346
347 err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags);
348 if (err < 0) {
349 /* -EMSGSIZE implies BUG in nh_nlmsg_size() */
350 WARN_ON(err == -EMSGSIZE);
351 kfree_skb(skb);
352 goto errout;
353 }
354
355 rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_NEXTHOP,
356 info->nlh, gfp_any());
357 return;
358 errout:
359 if (err < 0)
360 rtnl_set_sk_err(info->nl_net, RTNLGRP_NEXTHOP, err);
361 }
362
363 static bool valid_group_nh(struct nexthop *nh, unsigned int npaths,
364 struct netlink_ext_ack *extack)
365 {
366 if (nh->is_group) {
367 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
368
369 /* nested multipath (group within a group) is not
370 * supported
371 */
372 if (nhg->mpath) {
373 NL_SET_ERR_MSG(extack,
374 "Multipath group can not be a nexthop within a group");
375 return false;
376 }
377 } else {
378 struct nh_info *nhi = rtnl_dereference(nh->nh_info);
379
380 if (nhi->reject_nh && npaths > 1) {
381 NL_SET_ERR_MSG(extack,
382 "Blackhole nexthop can not be used in a group with more than 1 path");
383 return false;
384 }
385 }
386
387 return true;
388 }
389
390 static int nh_check_attr_group(struct net *net, struct nlattr *tb[],
391 struct netlink_ext_ack *extack)
392 {
393 unsigned int len = nla_len(tb[NHA_GROUP]);
394 struct nexthop_grp *nhg;
395 unsigned int i, j;
396
397 if (len & (sizeof(struct nexthop_grp) - 1)) {
398 NL_SET_ERR_MSG(extack,
399 "Invalid length for nexthop group attribute");
400 return -EINVAL;
401 }
402
403 /* convert len to number of nexthop ids */
404 len /= sizeof(*nhg);
405
406 nhg = nla_data(tb[NHA_GROUP]);
407 for (i = 0; i < len; ++i) {
408 if (nhg[i].resvd1 || nhg[i].resvd2) {
409 NL_SET_ERR_MSG(extack, "Reserved fields in nexthop_grp must be 0");
410 return -EINVAL;
411 }
412 if (nhg[i].weight > 254) {
413 NL_SET_ERR_MSG(extack, "Invalid value for weight");
414 return -EINVAL;
415 }
416 for (j = i + 1; j < len; ++j) {
417 if (nhg[i].id == nhg[j].id) {
418 NL_SET_ERR_MSG(extack, "Nexthop id can not be used twice in a group");
419 return -EINVAL;
420 }
421 }
422 }
423
424 nhg = nla_data(tb[NHA_GROUP]);
425 for (i = 0; i < len; ++i) {
426 struct nexthop *nh;
427
428 nh = nexthop_find_by_id(net, nhg[i].id);
429 if (!nh) {
430 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
431 return -EINVAL;
432 }
433 if (!valid_group_nh(nh, len, extack))
434 return -EINVAL;
435 }
436 for (i = NHA_GROUP + 1; i < __NHA_MAX; ++i) {
437 if (!tb[i])
438 continue;
439
440 NL_SET_ERR_MSG(extack,
441 "No other attributes can be set in nexthop groups");
442 return -EINVAL;
443 }
444
445 return 0;
446 }
447
448 static bool ipv6_good_nh(const struct fib6_nh *nh)
449 {
450 int state = NUD_REACHABLE;
451 struct neighbour *n;
452
453 rcu_read_lock_bh();
454
455 n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6);
456 if (n)
457 state = n->nud_state;
458
459 rcu_read_unlock_bh();
460
461 return !!(state & NUD_VALID);
462 }
463
464 static bool ipv4_good_nh(const struct fib_nh *nh)
465 {
466 int state = NUD_REACHABLE;
467 struct neighbour *n;
468
469 rcu_read_lock_bh();
470
471 n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev,
472 (__force u32)nh->fib_nh_gw4);
473 if (n)
474 state = n->nud_state;
475
476 rcu_read_unlock_bh();
477
478 return !!(state & NUD_VALID);
479 }
480
481 struct nexthop *nexthop_select_path(struct nexthop *nh, int hash)
482 {
483 struct nexthop *rc = NULL;
484 struct nh_group *nhg;
485 int i;
486
487 if (!nh->is_group)
488 return nh;
489
490 nhg = rcu_dereference(nh->nh_grp);
491 for (i = 0; i < nhg->num_nh; ++i) {
492 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
493 struct nh_info *nhi;
494
495 if (hash > atomic_read(&nhge->upper_bound))
496 continue;
497
498 /* nexthops always check if it is good and does
499 * not rely on a sysctl for this behavior
500 */
501 nhi = rcu_dereference(nhge->nh->nh_info);
502 switch (nhi->family) {
503 case AF_INET:
504 if (ipv4_good_nh(&nhi->fib_nh))
505 return nhge->nh;
506 break;
507 case AF_INET6:
508 if (ipv6_good_nh(&nhi->fib6_nh))
509 return nhge->nh;
510 break;
511 }
512
513 if (!rc)
514 rc = nhge->nh;
515 }
516
517 return rc;
518 }
519 EXPORT_SYMBOL_GPL(nexthop_select_path);
520
521 int nexthop_for_each_fib6_nh(struct nexthop *nh,
522 int (*cb)(struct fib6_nh *nh, void *arg),
523 void *arg)
524 {
525 struct nh_info *nhi;
526 int err;
527
528 if (nh->is_group) {
529 struct nh_group *nhg;
530 int i;
531
532 nhg = rcu_dereference_rtnl(nh->nh_grp);
533 for (i = 0; i < nhg->num_nh; i++) {
534 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
535
536 nhi = rcu_dereference_rtnl(nhge->nh->nh_info);
537 err = cb(&nhi->fib6_nh, arg);
538 if (err)
539 return err;
540 }
541 } else {
542 nhi = rcu_dereference_rtnl(nh->nh_info);
543 err = cb(&nhi->fib6_nh, arg);
544 if (err)
545 return err;
546 }
547
548 return 0;
549 }
550 EXPORT_SYMBOL_GPL(nexthop_for_each_fib6_nh);
551
552 static int check_src_addr(const struct in6_addr *saddr,
553 struct netlink_ext_ack *extack)
554 {
555 if (!ipv6_addr_any(saddr)) {
556 NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects");
557 return -EINVAL;
558 }
559 return 0;
560 }
561
562 int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
563 struct netlink_ext_ack *extack)
564 {
565 struct nh_info *nhi;
566
567 /* fib6_src is unique to a fib6_info and limits the ability to cache
568 * routes in fib6_nh within a nexthop that is potentially shared
569 * across multiple fib entries. If the config wants to use source
570 * routing it can not use nexthop objects. mlxsw also does not allow
571 * fib6_src on routes.
572 */
573 if (cfg && check_src_addr(&cfg->fc_src, extack) < 0)
574 return -EINVAL;
575
576 if (nh->is_group) {
577 struct nh_group *nhg;
578
579 nhg = rtnl_dereference(nh->nh_grp);
580 if (nhg->has_v4)
581 goto no_v4_nh;
582 } else {
583 nhi = rtnl_dereference(nh->nh_info);
584 if (nhi->family == AF_INET)
585 goto no_v4_nh;
586 }
587
588 return 0;
589 no_v4_nh:
590 NL_SET_ERR_MSG(extack, "IPv6 routes can not use an IPv4 nexthop");
591 return -EINVAL;
592 }
593 EXPORT_SYMBOL_GPL(fib6_check_nexthop);
594
595 /* if existing nexthop has ipv6 routes linked to it, need
596 * to verify this new spec works with ipv6
597 */
598 static int fib6_check_nh_list(struct nexthop *old, struct nexthop *new,
599 struct netlink_ext_ack *extack)
600 {
601 struct fib6_info *f6i;
602
603 if (list_empty(&old->f6i_list))
604 return 0;
605
606 list_for_each_entry(f6i, &old->f6i_list, nh_list) {
607 if (check_src_addr(&f6i->fib6_src.addr, extack) < 0)
608 return -EINVAL;
609 }
610
611 return fib6_check_nexthop(new, NULL, extack);
612 }
613
614 static int nexthop_check_scope(struct nexthop *nh, u8 scope,
615 struct netlink_ext_ack *extack)
616 {
617 struct nh_info *nhi;
618
619 nhi = rtnl_dereference(nh->nh_info);
620 if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) {
621 NL_SET_ERR_MSG(extack,
622 "Route with host scope can not have a gateway");
623 return -EINVAL;
624 }
625
626 if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) {
627 NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop");
628 return -EINVAL;
629 }
630
631 return 0;
632 }
633
634 /* Invoked by fib add code to verify nexthop by id is ok with
635 * config for prefix; parts of fib_check_nh not done when nexthop
636 * object is used.
637 */
638 int fib_check_nexthop(struct nexthop *nh, u8 scope,
639 struct netlink_ext_ack *extack)
640 {
641 int err = 0;
642
643 if (nh->is_group) {
644 struct nh_group *nhg;
645
646 if (scope == RT_SCOPE_HOST) {
647 NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops");
648 err = -EINVAL;
649 goto out;
650 }
651
652 nhg = rtnl_dereference(nh->nh_grp);
653 /* all nexthops in a group have the same scope */
654 err = nexthop_check_scope(nhg->nh_entries[0].nh, scope, extack);
655 } else {
656 err = nexthop_check_scope(nh, scope, extack);
657 }
658 out:
659 return err;
660 }
661
662 static int fib_check_nh_list(struct nexthop *old, struct nexthop *new,
663 struct netlink_ext_ack *extack)
664 {
665 struct fib_info *fi;
666
667 list_for_each_entry(fi, &old->fi_list, nh_list) {
668 int err;
669
670 err = fib_check_nexthop(new, fi->fib_scope, extack);
671 if (err)
672 return err;
673 }
674 return 0;
675 }
676
677 static void nh_group_rebalance(struct nh_group *nhg)
678 {
679 int total = 0;
680 int w = 0;
681 int i;
682
683 for (i = 0; i < nhg->num_nh; ++i)
684 total += nhg->nh_entries[i].weight;
685
686 for (i = 0; i < nhg->num_nh; ++i) {
687 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
688 int upper_bound;
689
690 w += nhge->weight;
691 upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, total) - 1;
692 atomic_set(&nhge->upper_bound, upper_bound);
693 }
694 }
695
696 static void remove_nh_grp_entry(struct nh_grp_entry *nhge,
697 struct nh_group *nhg,
698 struct nl_info *nlinfo)
699 {
700 struct nexthop *nh = nhge->nh;
701 struct nh_grp_entry *nhges;
702 bool found = false;
703 int i;
704
705 WARN_ON(!nh);
706
707 nhges = nhg->nh_entries;
708 for (i = 0; i < nhg->num_nh; ++i) {
709 if (found) {
710 nhges[i-1].nh = nhges[i].nh;
711 nhges[i-1].weight = nhges[i].weight;
712 list_del(&nhges[i].nh_list);
713 list_add(&nhges[i-1].nh_list, &nhges[i-1].nh->grp_list);
714 } else if (nhg->nh_entries[i].nh == nh) {
715 found = true;
716 }
717 }
718
719 if (WARN_ON(!found))
720 return;
721
722 nhg->num_nh--;
723 nhg->nh_entries[nhg->num_nh].nh = NULL;
724
725 nh_group_rebalance(nhg);
726
727 nexthop_put(nh);
728
729 if (nlinfo)
730 nexthop_notify(RTM_NEWNEXTHOP, nhge->nh_parent, nlinfo);
731 }
732
733 static void remove_nexthop_from_groups(struct net *net, struct nexthop *nh,
734 struct nl_info *nlinfo)
735 {
736 struct nh_grp_entry *nhge, *tmp;
737
738 list_for_each_entry_safe(nhge, tmp, &nh->grp_list, nh_list) {
739 struct nh_group *nhg;
740
741 list_del(&nhge->nh_list);
742 nhg = rtnl_dereference(nhge->nh_parent->nh_grp);
743 remove_nh_grp_entry(nhge, nhg, nlinfo);
744
745 /* if this group has no more entries then remove it */
746 if (!nhg->num_nh)
747 remove_nexthop(net, nhge->nh_parent, nlinfo);
748 }
749 }
750
751 static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo)
752 {
753 struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp);
754 int i, num_nh = nhg->num_nh;
755
756 for (i = 0; i < num_nh; ++i) {
757 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
758
759 if (WARN_ON(!nhge->nh))
760 continue;
761
762 list_del(&nhge->nh_list);
763 nexthop_put(nhge->nh);
764 nhge->nh = NULL;
765 nhg->num_nh--;
766 }
767 }
768
769 /* not called for nexthop replace */
770 static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
771 {
772 struct fib6_info *f6i, *tmp;
773 bool do_flush = false;
774 struct fib_info *fi;
775
776 list_for_each_entry(fi, &nh->fi_list, nh_list) {
777 fi->fib_flags |= RTNH_F_DEAD;
778 do_flush = true;
779 }
780 if (do_flush)
781 fib_flush(net);
782
783 /* ip6_del_rt removes the entry from this list hence the _safe */
784 list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) {
785 /* __ip6_del_rt does a release, so do a hold here */
786 fib6_info_hold(f6i);
787 ipv6_stub->ip6_del_rt(net, f6i);
788 }
789 }
790
791 static void __remove_nexthop(struct net *net, struct nexthop *nh,
792 struct nl_info *nlinfo)
793 {
794 __remove_nexthop_fib(net, nh);
795
796 if (nh->is_group) {
797 remove_nexthop_group(nh, nlinfo);
798 } else {
799 struct nh_info *nhi;
800
801 nhi = rtnl_dereference(nh->nh_info);
802 if (nhi->fib_nhc.nhc_dev)
803 hlist_del(&nhi->dev_hash);
804
805 remove_nexthop_from_groups(net, nh, nlinfo);
806 }
807 }
808
809 static void remove_nexthop(struct net *net, struct nexthop *nh,
810 struct nl_info *nlinfo)
811 {
812 /* remove from the tree */
813 rb_erase(&nh->rb_node, &net->nexthop.rb_root);
814
815 if (nlinfo)
816 nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo);
817
818 __remove_nexthop(net, nh, nlinfo);
819 nh_base_seq_inc(net);
820
821 nexthop_put(nh);
822 }
823
824 /* if any FIB entries reference this nexthop, any dst entries
825 * need to be regenerated
826 */
827 static void nh_rt_cache_flush(struct net *net, struct nexthop *nh)
828 {
829 struct fib6_info *f6i;
830
831 if (!list_empty(&nh->fi_list))
832 rt_cache_flush(net);
833
834 list_for_each_entry(f6i, &nh->f6i_list, nh_list)
835 ipv6_stub->fib6_update_sernum(net, f6i);
836 }
837
838 static int replace_nexthop_grp(struct net *net, struct nexthop *old,
839 struct nexthop *new,
840 struct netlink_ext_ack *extack)
841 {
842 struct nh_group *oldg, *newg;
843 int i;
844
845 if (!new->is_group) {
846 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop.");
847 return -EINVAL;
848 }
849
850 oldg = rtnl_dereference(old->nh_grp);
851 newg = rtnl_dereference(new->nh_grp);
852
853 /* update parents - used by nexthop code for cleanup */
854 for (i = 0; i < newg->num_nh; i++)
855 newg->nh_entries[i].nh_parent = old;
856
857 rcu_assign_pointer(old->nh_grp, newg);
858
859 for (i = 0; i < oldg->num_nh; i++)
860 oldg->nh_entries[i].nh_parent = new;
861
862 rcu_assign_pointer(new->nh_grp, oldg);
863
864 return 0;
865 }
866
867 static int replace_nexthop_single(struct net *net, struct nexthop *old,
868 struct nexthop *new,
869 struct netlink_ext_ack *extack)
870 {
871 struct nh_info *oldi, *newi;
872
873 if (new->is_group) {
874 NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group.");
875 return -EINVAL;
876 }
877
878 oldi = rtnl_dereference(old->nh_info);
879 newi = rtnl_dereference(new->nh_info);
880
881 newi->nh_parent = old;
882 oldi->nh_parent = new;
883
884 old->protocol = new->protocol;
885 old->nh_flags = new->nh_flags;
886
887 rcu_assign_pointer(old->nh_info, newi);
888 rcu_assign_pointer(new->nh_info, oldi);
889
890 return 0;
891 }
892
893 static void __nexthop_replace_notify(struct net *net, struct nexthop *nh,
894 struct nl_info *info)
895 {
896 struct fib6_info *f6i;
897
898 if (!list_empty(&nh->fi_list)) {
899 struct fib_info *fi;
900
901 /* expectation is a few fib_info per nexthop and then
902 * a lot of routes per fib_info. So mark the fib_info
903 * and then walk the fib tables once
904 */
905 list_for_each_entry(fi, &nh->fi_list, nh_list)
906 fi->nh_updated = true;
907
908 fib_info_notify_update(net, info);
909
910 list_for_each_entry(fi, &nh->fi_list, nh_list)
911 fi->nh_updated = false;
912 }
913
914 list_for_each_entry(f6i, &nh->f6i_list, nh_list)
915 ipv6_stub->fib6_rt_update(net, f6i, info);
916 }
917
918 /* send RTM_NEWROUTE with REPLACE flag set for all FIB entries
919 * linked to this nexthop and for all groups that the nexthop
920 * is a member of
921 */
922 static void nexthop_replace_notify(struct net *net, struct nexthop *nh,
923 struct nl_info *info)
924 {
925 struct nh_grp_entry *nhge;
926
927 __nexthop_replace_notify(net, nh, info);
928
929 list_for_each_entry(nhge, &nh->grp_list, nh_list)
930 __nexthop_replace_notify(net, nhge->nh_parent, info);
931 }
932
933 static int replace_nexthop(struct net *net, struct nexthop *old,
934 struct nexthop *new, struct netlink_ext_ack *extack)
935 {
936 bool new_is_reject = false;
937 struct nh_grp_entry *nhge;
938 int err;
939
940 /* check that existing FIB entries are ok with the
941 * new nexthop definition
942 */
943 err = fib_check_nh_list(old, new, extack);
944 if (err)
945 return err;
946
947 err = fib6_check_nh_list(old, new, extack);
948 if (err)
949 return err;
950
951 if (!new->is_group) {
952 struct nh_info *nhi = rtnl_dereference(new->nh_info);
953
954 new_is_reject = nhi->reject_nh;
955 }
956
957 list_for_each_entry(nhge, &old->grp_list, nh_list) {
958 /* if new nexthop is a blackhole, any groups using this
959 * nexthop cannot have more than 1 path
960 */
961 if (new_is_reject &&
962 nexthop_num_path(nhge->nh_parent) > 1) {
963 NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path");
964 return -EINVAL;
965 }
966
967 err = fib_check_nh_list(nhge->nh_parent, new, extack);
968 if (err)
969 return err;
970
971 err = fib6_check_nh_list(nhge->nh_parent, new, extack);
972 if (err)
973 return err;
974 }
975
976 if (old->is_group)
977 err = replace_nexthop_grp(net, old, new, extack);
978 else
979 err = replace_nexthop_single(net, old, new, extack);
980
981 if (!err) {
982 nh_rt_cache_flush(net, old);
983
984 __remove_nexthop(net, new, NULL);
985 nexthop_put(new);
986 }
987
988 return err;
989 }
990
991 /* called with rtnl_lock held */
992 static int insert_nexthop(struct net *net, struct nexthop *new_nh,
993 struct nh_config *cfg, struct netlink_ext_ack *extack)
994 {
995 struct rb_node **pp, *parent = NULL, *next;
996 struct rb_root *root = &net->nexthop.rb_root;
997 bool replace = !!(cfg->nlflags & NLM_F_REPLACE);
998 bool create = !!(cfg->nlflags & NLM_F_CREATE);
999 u32 new_id = new_nh->id;
1000 int replace_notify = 0;
1001 int rc = -EEXIST;
1002
1003 pp = &root->rb_node;
1004 while (1) {
1005 struct nexthop *nh;
1006
1007 next = rtnl_dereference(*pp);
1008 if (!next)
1009 break;
1010
1011 parent = next;
1012
1013 nh = rb_entry(parent, struct nexthop, rb_node);
1014 if (new_id < nh->id) {
1015 pp = &next->rb_left;
1016 } else if (new_id > nh->id) {
1017 pp = &next->rb_right;
1018 } else if (replace) {
1019 rc = replace_nexthop(net, nh, new_nh, extack);
1020 if (!rc) {
1021 new_nh = nh; /* send notification with old nh */
1022 replace_notify = 1;
1023 }
1024 goto out;
1025 } else {
1026 /* id already exists and not a replace */
1027 goto out;
1028 }
1029 }
1030
1031 if (replace && !create) {
1032 NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists");
1033 rc = -ENOENT;
1034 goto out;
1035 }
1036
1037 rb_link_node_rcu(&new_nh->rb_node, parent, pp);
1038 rb_insert_color(&new_nh->rb_node, root);
1039 rc = 0;
1040 out:
1041 if (!rc) {
1042 nh_base_seq_inc(net);
1043 nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo);
1044 if (replace_notify)
1045 nexthop_replace_notify(net, new_nh, &cfg->nlinfo);
1046 }
1047
1048 return rc;
1049 }
1050
1051 /* rtnl */
1052 /* remove all nexthops tied to a device being deleted */
1053 static void nexthop_flush_dev(struct net_device *dev)
1054 {
1055 unsigned int hash = nh_dev_hashfn(dev->ifindex);
1056 struct net *net = dev_net(dev);
1057 struct hlist_head *head = &net->nexthop.devhash[hash];
1058 struct hlist_node *n;
1059 struct nh_info *nhi;
1060
1061 hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
1062 if (nhi->fib_nhc.nhc_dev != dev)
1063 continue;
1064
1065 remove_nexthop(net, nhi->nh_parent, NULL);
1066 }
1067 }
1068
1069 /* rtnl; called when net namespace is deleted */
1070 static void flush_all_nexthops(struct net *net)
1071 {
1072 struct rb_root *root = &net->nexthop.rb_root;
1073 struct rb_node *node;
1074 struct nexthop *nh;
1075
1076 while ((node = rb_first(root))) {
1077 nh = rb_entry(node, struct nexthop, rb_node);
1078 remove_nexthop(net, nh, NULL);
1079 cond_resched();
1080 }
1081 }
1082
1083 static struct nexthop *nexthop_create_group(struct net *net,
1084 struct nh_config *cfg)
1085 {
1086 struct nlattr *grps_attr = cfg->nh_grp;
1087 struct nexthop_grp *entry = nla_data(grps_attr);
1088 struct nh_group *nhg;
1089 struct nexthop *nh;
1090 int i;
1091
1092 nh = nexthop_alloc();
1093 if (!nh)
1094 return ERR_PTR(-ENOMEM);
1095
1096 nh->is_group = 1;
1097
1098 nhg = nexthop_grp_alloc(nla_len(grps_attr) / sizeof(*entry));
1099 if (!nhg) {
1100 kfree(nh);
1101 return ERR_PTR(-ENOMEM);
1102 }
1103
1104 for (i = 0; i < nhg->num_nh; ++i) {
1105 struct nexthop *nhe;
1106 struct nh_info *nhi;
1107
1108 nhe = nexthop_find_by_id(net, entry[i].id);
1109 if (!nexthop_get(nhe))
1110 goto out_no_nh;
1111
1112 nhi = rtnl_dereference(nhe->nh_info);
1113 if (nhi->family == AF_INET)
1114 nhg->has_v4 = true;
1115
1116 nhg->nh_entries[i].nh = nhe;
1117 nhg->nh_entries[i].weight = entry[i].weight + 1;
1118 list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list);
1119 nhg->nh_entries[i].nh_parent = nh;
1120 }
1121
1122 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) {
1123 nhg->mpath = 1;
1124 nh_group_rebalance(nhg);
1125 }
1126
1127 rcu_assign_pointer(nh->nh_grp, nhg);
1128
1129 return nh;
1130
1131 out_no_nh:
1132 for (; i >= 0; --i)
1133 nexthop_put(nhg->nh_entries[i].nh);
1134
1135 kfree(nhg);
1136 kfree(nh);
1137
1138 return ERR_PTR(-ENOENT);
1139 }
1140
1141 static int nh_create_ipv4(struct net *net, struct nexthop *nh,
1142 struct nh_info *nhi, struct nh_config *cfg,
1143 struct netlink_ext_ack *extack)
1144 {
1145 struct fib_nh *fib_nh = &nhi->fib_nh;
1146 struct fib_config fib_cfg = {
1147 .fc_oif = cfg->nh_ifindex,
1148 .fc_gw4 = cfg->gw.ipv4,
1149 .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0,
1150 .fc_flags = cfg->nh_flags,
1151 .fc_encap = cfg->nh_encap,
1152 .fc_encap_type = cfg->nh_encap_type,
1153 };
1154 u32 tb_id = l3mdev_fib_table(cfg->dev);
1155 int err;
1156
1157 err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack);
1158 if (err) {
1159 fib_nh_release(net, fib_nh);
1160 goto out;
1161 }
1162
1163 /* sets nh_dev if successful */
1164 err = fib_check_nh(net, fib_nh, tb_id, 0, extack);
1165 if (!err) {
1166 nh->nh_flags = fib_nh->fib_nh_flags;
1167 fib_info_update_nhc_saddr(net, &fib_nh->nh_common,
1168 fib_nh->fib_nh_scope);
1169 } else {
1170 fib_nh_release(net, fib_nh);
1171 }
1172 out:
1173 return err;
1174 }
1175
1176 static int nh_create_ipv6(struct net *net, struct nexthop *nh,
1177 struct nh_info *nhi, struct nh_config *cfg,
1178 struct netlink_ext_ack *extack)
1179 {
1180 struct fib6_nh *fib6_nh = &nhi->fib6_nh;
1181 struct fib6_config fib6_cfg = {
1182 .fc_table = l3mdev_fib_table(cfg->dev),
1183 .fc_ifindex = cfg->nh_ifindex,
1184 .fc_gateway = cfg->gw.ipv6,
1185 .fc_flags = cfg->nh_flags,
1186 .fc_encap = cfg->nh_encap,
1187 .fc_encap_type = cfg->nh_encap_type,
1188 };
1189 int err;
1190
1191 if (!ipv6_addr_any(&cfg->gw.ipv6))
1192 fib6_cfg.fc_flags |= RTF_GATEWAY;
1193
1194 /* sets nh_dev if successful */
1195 err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL,
1196 extack);
1197 if (err)
1198 ipv6_stub->fib6_nh_release(fib6_nh);
1199 else
1200 nh->nh_flags = fib6_nh->fib_nh_flags;
1201
1202 return err;
1203 }
1204
1205 static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg,
1206 struct netlink_ext_ack *extack)
1207 {
1208 struct nh_info *nhi;
1209 struct nexthop *nh;
1210 int err = 0;
1211
1212 nh = nexthop_alloc();
1213 if (!nh)
1214 return ERR_PTR(-ENOMEM);
1215
1216 nhi = kzalloc(sizeof(*nhi), GFP_KERNEL);
1217 if (!nhi) {
1218 kfree(nh);
1219 return ERR_PTR(-ENOMEM);
1220 }
1221
1222 nh->nh_flags = cfg->nh_flags;
1223 nh->net = net;
1224
1225 nhi->nh_parent = nh;
1226 nhi->family = cfg->nh_family;
1227 nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK;
1228
1229 if (cfg->nh_blackhole) {
1230 nhi->reject_nh = 1;
1231 cfg->nh_ifindex = net->loopback_dev->ifindex;
1232 }
1233
1234 switch (cfg->nh_family) {
1235 case AF_INET:
1236 err = nh_create_ipv4(net, nh, nhi, cfg, extack);
1237 break;
1238 case AF_INET6:
1239 err = nh_create_ipv6(net, nh, nhi, cfg, extack);
1240 break;
1241 }
1242
1243 if (err) {
1244 kfree(nhi);
1245 kfree(nh);
1246 return ERR_PTR(err);
1247 }
1248
1249 /* add the entry to the device based hash */
1250 nexthop_devhash_add(net, nhi);
1251
1252 rcu_assign_pointer(nh->nh_info, nhi);
1253
1254 return nh;
1255 }
1256
1257 /* called with rtnl lock held */
1258 static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg,
1259 struct netlink_ext_ack *extack)
1260 {
1261 struct nexthop *nh;
1262 int err;
1263
1264 if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) {
1265 NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
1266 return ERR_PTR(-EINVAL);
1267 }
1268
1269 if (!cfg->nh_id) {
1270 cfg->nh_id = nh_find_unused_id(net);
1271 if (!cfg->nh_id) {
1272 NL_SET_ERR_MSG(extack, "No unused id");
1273 return ERR_PTR(-EINVAL);
1274 }
1275 }
1276
1277 if (cfg->nh_grp)
1278 nh = nexthop_create_group(net, cfg);
1279 else
1280 nh = nexthop_create(net, cfg, extack);
1281
1282 if (IS_ERR(nh))
1283 return nh;
1284
1285 refcount_set(&nh->refcnt, 1);
1286 nh->id = cfg->nh_id;
1287 nh->protocol = cfg->nh_protocol;
1288 nh->net = net;
1289
1290 err = insert_nexthop(net, nh, cfg, extack);
1291 if (err) {
1292 __remove_nexthop(net, nh, NULL);
1293 nexthop_put(nh);
1294 nh = ERR_PTR(err);
1295 }
1296
1297 return nh;
1298 }
1299
1300 static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
1301 struct nlmsghdr *nlh, struct nh_config *cfg,
1302 struct netlink_ext_ack *extack)
1303 {
1304 struct nhmsg *nhm = nlmsg_data(nlh);
1305 struct nlattr *tb[NHA_MAX + 1];
1306 int err;
1307
1308 err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1309 extack);
1310 if (err < 0)
1311 return err;
1312
1313 err = -EINVAL;
1314 if (nhm->resvd || nhm->nh_scope) {
1315 NL_SET_ERR_MSG(extack, "Invalid values in ancillary header");
1316 goto out;
1317 }
1318 if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) {
1319 NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header");
1320 goto out;
1321 }
1322
1323 switch (nhm->nh_family) {
1324 case AF_INET:
1325 case AF_INET6:
1326 break;
1327 case AF_UNSPEC:
1328 if (tb[NHA_GROUP])
1329 break;
1330 fallthrough;
1331 default:
1332 NL_SET_ERR_MSG(extack, "Invalid address family");
1333 goto out;
1334 }
1335
1336 if (tb[NHA_GROUPS] || tb[NHA_MASTER]) {
1337 NL_SET_ERR_MSG(extack, "Invalid attributes in request");
1338 goto out;
1339 }
1340
1341 memset(cfg, 0, sizeof(*cfg));
1342 cfg->nlflags = nlh->nlmsg_flags;
1343 cfg->nlinfo.portid = NETLINK_CB(skb).portid;
1344 cfg->nlinfo.nlh = nlh;
1345 cfg->nlinfo.nl_net = net;
1346
1347 cfg->nh_family = nhm->nh_family;
1348 cfg->nh_protocol = nhm->nh_protocol;
1349 cfg->nh_flags = nhm->nh_flags;
1350
1351 if (tb[NHA_ID])
1352 cfg->nh_id = nla_get_u32(tb[NHA_ID]);
1353
1354 if (tb[NHA_GROUP]) {
1355 if (nhm->nh_family != AF_UNSPEC) {
1356 NL_SET_ERR_MSG(extack, "Invalid family for group");
1357 goto out;
1358 }
1359 cfg->nh_grp = tb[NHA_GROUP];
1360
1361 cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH;
1362 if (tb[NHA_GROUP_TYPE])
1363 cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]);
1364
1365 if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) {
1366 NL_SET_ERR_MSG(extack, "Invalid group type");
1367 goto out;
1368 }
1369 err = nh_check_attr_group(net, tb, extack);
1370
1371 /* no other attributes should be set */
1372 goto out;
1373 }
1374
1375 if (tb[NHA_BLACKHOLE]) {
1376 if (tb[NHA_GATEWAY] || tb[NHA_OIF] ||
1377 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) {
1378 NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway or oif");
1379 goto out;
1380 }
1381
1382 cfg->nh_blackhole = 1;
1383 err = 0;
1384 goto out;
1385 }
1386
1387 if (!tb[NHA_OIF]) {
1388 NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole nexthops");
1389 goto out;
1390 }
1391
1392 cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
1393 if (cfg->nh_ifindex)
1394 cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
1395
1396 if (!cfg->dev) {
1397 NL_SET_ERR_MSG(extack, "Invalid device index");
1398 goto out;
1399 } else if (!(cfg->dev->flags & IFF_UP)) {
1400 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
1401 err = -ENETDOWN;
1402 goto out;
1403 } else if (!netif_carrier_ok(cfg->dev)) {
1404 NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");
1405 err = -ENETDOWN;
1406 goto out;
1407 }
1408
1409 err = -EINVAL;
1410 if (tb[NHA_GATEWAY]) {
1411 struct nlattr *gwa = tb[NHA_GATEWAY];
1412
1413 switch (cfg->nh_family) {
1414 case AF_INET:
1415 if (nla_len(gwa) != sizeof(u32)) {
1416 NL_SET_ERR_MSG(extack, "Invalid gateway");
1417 goto out;
1418 }
1419 cfg->gw.ipv4 = nla_get_be32(gwa);
1420 break;
1421 case AF_INET6:
1422 if (nla_len(gwa) != sizeof(struct in6_addr)) {
1423 NL_SET_ERR_MSG(extack, "Invalid gateway");
1424 goto out;
1425 }
1426 cfg->gw.ipv6 = nla_get_in6_addr(gwa);
1427 break;
1428 default:
1429 NL_SET_ERR_MSG(extack,
1430 "Unknown address family for gateway");
1431 goto out;
1432 }
1433 } else {
1434 /* device only nexthop (no gateway) */
1435 if (cfg->nh_flags & RTNH_F_ONLINK) {
1436 NL_SET_ERR_MSG(extack,
1437 "ONLINK flag can not be set for nexthop without a gateway");
1438 goto out;
1439 }
1440 }
1441
1442 if (tb[NHA_ENCAP]) {
1443 cfg->nh_encap = tb[NHA_ENCAP];
1444
1445 if (!tb[NHA_ENCAP_TYPE]) {
1446 NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing");
1447 goto out;
1448 }
1449
1450 cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]);
1451 err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack);
1452 if (err < 0)
1453 goto out;
1454
1455 } else if (tb[NHA_ENCAP_TYPE]) {
1456 NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing");
1457 goto out;
1458 }
1459
1460
1461 err = 0;
1462 out:
1463 return err;
1464 }
1465
1466 /* rtnl */
1467 static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
1468 struct netlink_ext_ack *extack)
1469 {
1470 struct net *net = sock_net(skb->sk);
1471 struct nh_config cfg;
1472 struct nexthop *nh;
1473 int err;
1474
1475 err = rtm_to_nh_config(net, skb, nlh, &cfg, extack);
1476 if (!err) {
1477 nh = nexthop_add(net, &cfg, extack);
1478 if (IS_ERR(nh))
1479 err = PTR_ERR(nh);
1480 }
1481
1482 return err;
1483 }
1484
1485 static int nh_valid_get_del_req(struct nlmsghdr *nlh, u32 *id,
1486 struct netlink_ext_ack *extack)
1487 {
1488 struct nhmsg *nhm = nlmsg_data(nlh);
1489 struct nlattr *tb[NHA_MAX + 1];
1490 int err, i;
1491
1492 err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1493 extack);
1494 if (err < 0)
1495 return err;
1496
1497 err = -EINVAL;
1498 for (i = 0; i < __NHA_MAX; ++i) {
1499 if (!tb[i])
1500 continue;
1501
1502 switch (i) {
1503 case NHA_ID:
1504 break;
1505 default:
1506 NL_SET_ERR_MSG_ATTR(extack, tb[i],
1507 "Unexpected attribute in request");
1508 goto out;
1509 }
1510 }
1511 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
1512 NL_SET_ERR_MSG(extack, "Invalid values in header");
1513 goto out;
1514 }
1515
1516 if (!tb[NHA_ID]) {
1517 NL_SET_ERR_MSG(extack, "Nexthop id is missing");
1518 goto out;
1519 }
1520
1521 *id = nla_get_u32(tb[NHA_ID]);
1522 if (!(*id))
1523 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
1524 else
1525 err = 0;
1526 out:
1527 return err;
1528 }
1529
1530 /* rtnl */
1531 static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
1532 struct netlink_ext_ack *extack)
1533 {
1534 struct net *net = sock_net(skb->sk);
1535 struct nl_info nlinfo = {
1536 .nlh = nlh,
1537 .nl_net = net,
1538 .portid = NETLINK_CB(skb).portid,
1539 };
1540 struct nexthop *nh;
1541 int err;
1542 u32 id;
1543
1544 err = nh_valid_get_del_req(nlh, &id, extack);
1545 if (err)
1546 return err;
1547
1548 nh = nexthop_find_by_id(net, id);
1549 if (!nh)
1550 return -ENOENT;
1551
1552 remove_nexthop(net, nh, &nlinfo);
1553
1554 return 0;
1555 }
1556
1557 /* rtnl */
1558 static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh,
1559 struct netlink_ext_ack *extack)
1560 {
1561 struct net *net = sock_net(in_skb->sk);
1562 struct sk_buff *skb = NULL;
1563 struct nexthop *nh;
1564 int err;
1565 u32 id;
1566
1567 err = nh_valid_get_del_req(nlh, &id, extack);
1568 if (err)
1569 return err;
1570
1571 err = -ENOBUFS;
1572 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1573 if (!skb)
1574 goto out;
1575
1576 err = -ENOENT;
1577 nh = nexthop_find_by_id(net, id);
1578 if (!nh)
1579 goto errout_free;
1580
1581 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid,
1582 nlh->nlmsg_seq, 0);
1583 if (err < 0) {
1584 WARN_ON(err == -EMSGSIZE);
1585 goto errout_free;
1586 }
1587
1588 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
1589 out:
1590 return err;
1591 errout_free:
1592 kfree_skb(skb);
1593 goto out;
1594 }
1595
1596 static bool nh_dump_filtered(struct nexthop *nh, int dev_idx, int master_idx,
1597 bool group_filter, u8 family)
1598 {
1599 const struct net_device *dev;
1600 const struct nh_info *nhi;
1601
1602 if (group_filter && !nh->is_group)
1603 return true;
1604
1605 if (!dev_idx && !master_idx && !family)
1606 return false;
1607
1608 if (nh->is_group)
1609 return true;
1610
1611 nhi = rtnl_dereference(nh->nh_info);
1612 if (family && nhi->family != family)
1613 return true;
1614
1615 dev = nhi->fib_nhc.nhc_dev;
1616 if (dev_idx && (!dev || dev->ifindex != dev_idx))
1617 return true;
1618
1619 if (master_idx) {
1620 struct net_device *master;
1621
1622 if (!dev)
1623 return true;
1624
1625 master = netdev_master_upper_dev_get((struct net_device *)dev);
1626 if (!master || master->ifindex != master_idx)
1627 return true;
1628 }
1629
1630 return false;
1631 }
1632
1633 static int nh_valid_dump_req(const struct nlmsghdr *nlh, int *dev_idx,
1634 int *master_idx, bool *group_filter,
1635 struct netlink_callback *cb)
1636 {
1637 struct netlink_ext_ack *extack = cb->extack;
1638 struct nlattr *tb[NHA_MAX + 1];
1639 struct nhmsg *nhm;
1640 int err, i;
1641 u32 idx;
1642
1643 err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1644 NULL);
1645 if (err < 0)
1646 return err;
1647
1648 for (i = 0; i <= NHA_MAX; ++i) {
1649 if (!tb[i])
1650 continue;
1651
1652 switch (i) {
1653 case NHA_OIF:
1654 idx = nla_get_u32(tb[i]);
1655 if (idx > INT_MAX) {
1656 NL_SET_ERR_MSG(extack, "Invalid device index");
1657 return -EINVAL;
1658 }
1659 *dev_idx = idx;
1660 break;
1661 case NHA_MASTER:
1662 idx = nla_get_u32(tb[i]);
1663 if (idx > INT_MAX) {
1664 NL_SET_ERR_MSG(extack, "Invalid master device index");
1665 return -EINVAL;
1666 }
1667 *master_idx = idx;
1668 break;
1669 case NHA_GROUPS:
1670 *group_filter = true;
1671 break;
1672 default:
1673 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
1674 return -EINVAL;
1675 }
1676 }
1677
1678 nhm = nlmsg_data(nlh);
1679 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
1680 NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request");
1681 return -EINVAL;
1682 }
1683
1684 return 0;
1685 }
1686
1687 /* rtnl */
1688 static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
1689 {
1690 struct nhmsg *nhm = nlmsg_data(cb->nlh);
1691 int dev_filter_idx = 0, master_idx = 0;
1692 struct net *net = sock_net(skb->sk);
1693 struct rb_root *root = &net->nexthop.rb_root;
1694 bool group_filter = false;
1695 struct rb_node *node;
1696 int idx = 0, s_idx;
1697 int err;
1698
1699 err = nh_valid_dump_req(cb->nlh, &dev_filter_idx, &master_idx,
1700 &group_filter, cb);
1701 if (err < 0)
1702 return err;
1703
1704 s_idx = cb->args[0];
1705 for (node = rb_first(root); node; node = rb_next(node)) {
1706 struct nexthop *nh;
1707
1708 if (idx < s_idx)
1709 goto cont;
1710
1711 nh = rb_entry(node, struct nexthop, rb_node);
1712 if (nh_dump_filtered(nh, dev_filter_idx, master_idx,
1713 group_filter, nhm->nh_family))
1714 goto cont;
1715
1716 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP,
1717 NETLINK_CB(cb->skb).portid,
1718 cb->nlh->nlmsg_seq, NLM_F_MULTI);
1719 if (err < 0) {
1720 if (likely(skb->len))
1721 goto out;
1722
1723 goto out_err;
1724 }
1725 cont:
1726 idx++;
1727 }
1728
1729 out:
1730 err = skb->len;
1731 out_err:
1732 cb->args[0] = idx;
1733 cb->seq = net->nexthop.seq;
1734 nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1735
1736 return err;
1737 }
1738
1739 static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu)
1740 {
1741 unsigned int hash = nh_dev_hashfn(dev->ifindex);
1742 struct net *net = dev_net(dev);
1743 struct hlist_head *head = &net->nexthop.devhash[hash];
1744 struct hlist_node *n;
1745 struct nh_info *nhi;
1746
1747 hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
1748 if (nhi->fib_nhc.nhc_dev == dev) {
1749 if (nhi->family == AF_INET)
1750 fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu,
1751 orig_mtu);
1752 }
1753 }
1754 }
1755
1756 /* rtnl */
1757 static int nh_netdev_event(struct notifier_block *this,
1758 unsigned long event, void *ptr)
1759 {
1760 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1761 struct netdev_notifier_info_ext *info_ext;
1762
1763 switch (event) {
1764 case NETDEV_DOWN:
1765 case NETDEV_UNREGISTER:
1766 nexthop_flush_dev(dev);
1767 break;
1768 case NETDEV_CHANGE:
1769 if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP)))
1770 nexthop_flush_dev(dev);
1771 break;
1772 case NETDEV_CHANGEMTU:
1773 info_ext = ptr;
1774 nexthop_sync_mtu(dev, info_ext->ext.mtu);
1775 rt_cache_flush(dev_net(dev));
1776 break;
1777 }
1778 return NOTIFY_DONE;
1779 }
1780
1781 static struct notifier_block nh_netdev_notifier = {
1782 .notifier_call = nh_netdev_event,
1783 };
1784
1785 static void __net_exit nexthop_net_exit(struct net *net)
1786 {
1787 rtnl_lock();
1788 flush_all_nexthops(net);
1789 rtnl_unlock();
1790 kfree(net->nexthop.devhash);
1791 }
1792
1793 static int __net_init nexthop_net_init(struct net *net)
1794 {
1795 size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE;
1796
1797 net->nexthop.rb_root = RB_ROOT;
1798 net->nexthop.devhash = kzalloc(sz, GFP_KERNEL);
1799 if (!net->nexthop.devhash)
1800 return -ENOMEM;
1801
1802 return 0;
1803 }
1804
1805 static struct pernet_operations nexthop_net_ops = {
1806 .init = nexthop_net_init,
1807 .exit = nexthop_net_exit,
1808 };
1809
1810 static int __init nexthop_init(void)
1811 {
1812 register_pernet_subsys(&nexthop_net_ops);
1813
1814 register_netdevice_notifier(&nh_netdev_notifier);
1815
1816 rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
1817 rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0);
1818 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop,
1819 rtm_dump_nexthop, 0);
1820
1821 rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
1822 rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
1823
1824 rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
1825 rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
1826
1827 return 0;
1828 }
1829 subsys_initcall(nexthop_init);
Linux with added FPC-III support