?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
octeontx2-pf: Fix error return code in otx2_probe()
[linux/fpc-iii.git] / net / ipv4 / nexthop.c
blob3957364d556cd73d158af2cc25dee2545d4491f9
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 !net->ipv4.sysctl_nexthop_compat_mode);
789 }
790 }
791
792 static void __remove_nexthop(struct net *net, struct nexthop *nh,
793 struct nl_info *nlinfo)
794 {
795 __remove_nexthop_fib(net, nh);
796
797 if (nh->is_group) {
798 remove_nexthop_group(nh, nlinfo);
799 } else {
800 struct nh_info *nhi;
801
802 nhi = rtnl_dereference(nh->nh_info);
803 if (nhi->fib_nhc.nhc_dev)
804 hlist_del(&nhi->dev_hash);
805
806 remove_nexthop_from_groups(net, nh, nlinfo);
807 }
808 }
809
810 static void remove_nexthop(struct net *net, struct nexthop *nh,
811 struct nl_info *nlinfo)
812 {
813 /* remove from the tree */
814 rb_erase(&nh->rb_node, &net->nexthop.rb_root);
815
816 if (nlinfo)
817 nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo);
818
819 __remove_nexthop(net, nh, nlinfo);
820 nh_base_seq_inc(net);
821
822 nexthop_put(nh);
823 }
824
825 /* if any FIB entries reference this nexthop, any dst entries
826 * need to be regenerated
827 */
828 static void nh_rt_cache_flush(struct net *net, struct nexthop *nh)
829 {
830 struct fib6_info *f6i;
831
832 if (!list_empty(&nh->fi_list))
833 rt_cache_flush(net);
834
835 list_for_each_entry(f6i, &nh->f6i_list, nh_list)
836 ipv6_stub->fib6_update_sernum(net, f6i);
837 }
838
839 static int replace_nexthop_grp(struct net *net, struct nexthop *old,
840 struct nexthop *new,
841 struct netlink_ext_ack *extack)
842 {
843 struct nh_group *oldg, *newg;
844 int i;
845
846 if (!new->is_group) {
847 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop.");
848 return -EINVAL;
849 }
850
851 oldg = rtnl_dereference(old->nh_grp);
852 newg = rtnl_dereference(new->nh_grp);
853
854 /* update parents - used by nexthop code for cleanup */
855 for (i = 0; i < newg->num_nh; i++)
856 newg->nh_entries[i].nh_parent = old;
857
858 rcu_assign_pointer(old->nh_grp, newg);
859
860 for (i = 0; i < oldg->num_nh; i++)
861 oldg->nh_entries[i].nh_parent = new;
862
863 rcu_assign_pointer(new->nh_grp, oldg);
864
865 return 0;
866 }
867
868 static int replace_nexthop_single(struct net *net, struct nexthop *old,
869 struct nexthop *new,
870 struct netlink_ext_ack *extack)
871 {
872 struct nh_info *oldi, *newi;
873
874 if (new->is_group) {
875 NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group.");
876 return -EINVAL;
877 }
878
879 oldi = rtnl_dereference(old->nh_info);
880 newi = rtnl_dereference(new->nh_info);
881
882 newi->nh_parent = old;
883 oldi->nh_parent = new;
884
885 old->protocol = new->protocol;
886 old->nh_flags = new->nh_flags;
887
888 rcu_assign_pointer(old->nh_info, newi);
889 rcu_assign_pointer(new->nh_info, oldi);
890
891 return 0;
892 }
893
894 static void __nexthop_replace_notify(struct net *net, struct nexthop *nh,
895 struct nl_info *info)
896 {
897 struct fib6_info *f6i;
898
899 if (!list_empty(&nh->fi_list)) {
900 struct fib_info *fi;
901
902 /* expectation is a few fib_info per nexthop and then
903 * a lot of routes per fib_info. So mark the fib_info
904 * and then walk the fib tables once
905 */
906 list_for_each_entry(fi, &nh->fi_list, nh_list)
907 fi->nh_updated = true;
908
909 fib_info_notify_update(net, info);
910
911 list_for_each_entry(fi, &nh->fi_list, nh_list)
912 fi->nh_updated = false;
913 }
914
915 list_for_each_entry(f6i, &nh->f6i_list, nh_list)
916 ipv6_stub->fib6_rt_update(net, f6i, info);
917 }
918
919 /* send RTM_NEWROUTE with REPLACE flag set for all FIB entries
920 * linked to this nexthop and for all groups that the nexthop
921 * is a member of
922 */
923 static void nexthop_replace_notify(struct net *net, struct nexthop *nh,
924 struct nl_info *info)
925 {
926 struct nh_grp_entry *nhge;
927
928 __nexthop_replace_notify(net, nh, info);
929
930 list_for_each_entry(nhge, &nh->grp_list, nh_list)
931 __nexthop_replace_notify(net, nhge->nh_parent, info);
932 }
933
934 static int replace_nexthop(struct net *net, struct nexthop *old,
935 struct nexthop *new, struct netlink_ext_ack *extack)
936 {
937 bool new_is_reject = false;
938 struct nh_grp_entry *nhge;
939 int err;
940
941 /* check that existing FIB entries are ok with the
942 * new nexthop definition
943 */
944 err = fib_check_nh_list(old, new, extack);
945 if (err)
946 return err;
947
948 err = fib6_check_nh_list(old, new, extack);
949 if (err)
950 return err;
951
952 if (!new->is_group) {
953 struct nh_info *nhi = rtnl_dereference(new->nh_info);
954
955 new_is_reject = nhi->reject_nh;
956 }
957
958 list_for_each_entry(nhge, &old->grp_list, nh_list) {
959 /* if new nexthop is a blackhole, any groups using this
960 * nexthop cannot have more than 1 path
961 */
962 if (new_is_reject &&
963 nexthop_num_path(nhge->nh_parent) > 1) {
964 NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path");
965 return -EINVAL;
966 }
967
968 err = fib_check_nh_list(nhge->nh_parent, new, extack);
969 if (err)
970 return err;
971
972 err = fib6_check_nh_list(nhge->nh_parent, new, extack);
973 if (err)
974 return err;
975 }
976
977 if (old->is_group)
978 err = replace_nexthop_grp(net, old, new, extack);
979 else
980 err = replace_nexthop_single(net, old, new, extack);
981
982 if (!err) {
983 nh_rt_cache_flush(net, old);
984
985 __remove_nexthop(net, new, NULL);
986 nexthop_put(new);
987 }
988
989 return err;
990 }
991
992 /* called with rtnl_lock held */
993 static int insert_nexthop(struct net *net, struct nexthop *new_nh,
994 struct nh_config *cfg, struct netlink_ext_ack *extack)
995 {
996 struct rb_node **pp, *parent = NULL, *next;
997 struct rb_root *root = &net->nexthop.rb_root;
998 bool replace = !!(cfg->nlflags & NLM_F_REPLACE);
999 bool create = !!(cfg->nlflags & NLM_F_CREATE);
1000 u32 new_id = new_nh->id;
1001 int replace_notify = 0;
1002 int rc = -EEXIST;
1003
1004 pp = &root->rb_node;
1005 while (1) {
1006 struct nexthop *nh;
1007
1008 next = rtnl_dereference(*pp);
1009 if (!next)
1010 break;
1011
1012 parent = next;
1013
1014 nh = rb_entry(parent, struct nexthop, rb_node);
1015 if (new_id < nh->id) {
1016 pp = &next->rb_left;
1017 } else if (new_id > nh->id) {
1018 pp = &next->rb_right;
1019 } else if (replace) {
1020 rc = replace_nexthop(net, nh, new_nh, extack);
1021 if (!rc) {
1022 new_nh = nh; /* send notification with old nh */
1023 replace_notify = 1;
1024 }
1025 goto out;
1026 } else {
1027 /* id already exists and not a replace */
1028 goto out;
1029 }
1030 }
1031
1032 if (replace && !create) {
1033 NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists");
1034 rc = -ENOENT;
1035 goto out;
1036 }
1037
1038 rb_link_node_rcu(&new_nh->rb_node, parent, pp);
1039 rb_insert_color(&new_nh->rb_node, root);
1040 rc = 0;
1041 out:
1042 if (!rc) {
1043 nh_base_seq_inc(net);
1044 nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo);
1045 if (replace_notify && net->ipv4.sysctl_nexthop_compat_mode)
1046 nexthop_replace_notify(net, new_nh, &cfg->nlinfo);
1047 }
1048
1049 return rc;
1050 }
1051
1052 /* rtnl */
1053 /* remove all nexthops tied to a device being deleted */
1054 static void nexthop_flush_dev(struct net_device *dev)
1055 {
1056 unsigned int hash = nh_dev_hashfn(dev->ifindex);
1057 struct net *net = dev_net(dev);
1058 struct hlist_head *head = &net->nexthop.devhash[hash];
1059 struct hlist_node *n;
1060 struct nh_info *nhi;
1061
1062 hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
1063 if (nhi->fib_nhc.nhc_dev != dev)
1064 continue;
1065
1066 remove_nexthop(net, nhi->nh_parent, NULL);
1067 }
1068 }
1069
1070 /* rtnl; called when net namespace is deleted */
1071 static void flush_all_nexthops(struct net *net)
1072 {
1073 struct rb_root *root = &net->nexthop.rb_root;
1074 struct rb_node *node;
1075 struct nexthop *nh;
1076
1077 while ((node = rb_first(root))) {
1078 nh = rb_entry(node, struct nexthop, rb_node);
1079 remove_nexthop(net, nh, NULL);
1080 cond_resched();
1081 }
1082 }
1083
1084 static struct nexthop *nexthop_create_group(struct net *net,
1085 struct nh_config *cfg)
1086 {
1087 struct nlattr *grps_attr = cfg->nh_grp;
1088 struct nexthop_grp *entry = nla_data(grps_attr);
1089 struct nh_group *nhg;
1090 struct nexthop *nh;
1091 int i;
1092
1093 nh = nexthop_alloc();
1094 if (!nh)
1095 return ERR_PTR(-ENOMEM);
1096
1097 nh->is_group = 1;
1098
1099 nhg = nexthop_grp_alloc(nla_len(grps_attr) / sizeof(*entry));
1100 if (!nhg) {
1101 kfree(nh);
1102 return ERR_PTR(-ENOMEM);
1103 }
1104
1105 for (i = 0; i < nhg->num_nh; ++i) {
1106 struct nexthop *nhe;
1107 struct nh_info *nhi;
1108
1109 nhe = nexthop_find_by_id(net, entry[i].id);
1110 if (!nexthop_get(nhe))
1111 goto out_no_nh;
1112
1113 nhi = rtnl_dereference(nhe->nh_info);
1114 if (nhi->family == AF_INET)
1115 nhg->has_v4 = true;
1116
1117 nhg->nh_entries[i].nh = nhe;
1118 nhg->nh_entries[i].weight = entry[i].weight + 1;
1119 list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list);
1120 nhg->nh_entries[i].nh_parent = nh;
1121 }
1122
1123 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) {
1124 nhg->mpath = 1;
1125 nh_group_rebalance(nhg);
1126 }
1127
1128 rcu_assign_pointer(nh->nh_grp, nhg);
1129
1130 return nh;
1131
1132 out_no_nh:
1133 for (; i >= 0; --i)
1134 nexthop_put(nhg->nh_entries[i].nh);
1135
1136 kfree(nhg);
1137 kfree(nh);
1138
1139 return ERR_PTR(-ENOENT);
1140 }
1141
1142 static int nh_create_ipv4(struct net *net, struct nexthop *nh,
1143 struct nh_info *nhi, struct nh_config *cfg,
1144 struct netlink_ext_ack *extack)
1145 {
1146 struct fib_nh *fib_nh = &nhi->fib_nh;
1147 struct fib_config fib_cfg = {
1148 .fc_oif = cfg->nh_ifindex,
1149 .fc_gw4 = cfg->gw.ipv4,
1150 .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0,
1151 .fc_flags = cfg->nh_flags,
1152 .fc_encap = cfg->nh_encap,
1153 .fc_encap_type = cfg->nh_encap_type,
1154 };
1155 u32 tb_id = l3mdev_fib_table(cfg->dev);
1156 int err;
1157
1158 err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack);
1159 if (err) {
1160 fib_nh_release(net, fib_nh);
1161 goto out;
1162 }
1163
1164 /* sets nh_dev if successful */
1165 err = fib_check_nh(net, fib_nh, tb_id, 0, extack);
1166 if (!err) {
1167 nh->nh_flags = fib_nh->fib_nh_flags;
1168 fib_info_update_nhc_saddr(net, &fib_nh->nh_common,
1169 fib_nh->fib_nh_scope);
1170 } else {
1171 fib_nh_release(net, fib_nh);
1172 }
1173 out:
1174 return err;
1175 }
1176
1177 static int nh_create_ipv6(struct net *net, struct nexthop *nh,
1178 struct nh_info *nhi, struct nh_config *cfg,
1179 struct netlink_ext_ack *extack)
1180 {
1181 struct fib6_nh *fib6_nh = &nhi->fib6_nh;
1182 struct fib6_config fib6_cfg = {
1183 .fc_table = l3mdev_fib_table(cfg->dev),
1184 .fc_ifindex = cfg->nh_ifindex,
1185 .fc_gateway = cfg->gw.ipv6,
1186 .fc_flags = cfg->nh_flags,
1187 .fc_encap = cfg->nh_encap,
1188 .fc_encap_type = cfg->nh_encap_type,
1189 };
1190 int err;
1191
1192 if (!ipv6_addr_any(&cfg->gw.ipv6))
1193 fib6_cfg.fc_flags |= RTF_GATEWAY;
1194
1195 /* sets nh_dev if successful */
1196 err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL,
1197 extack);
1198 if (err)
1199 ipv6_stub->fib6_nh_release(fib6_nh);
1200 else
1201 nh->nh_flags = fib6_nh->fib_nh_flags;
1202
1203 return err;
1204 }
1205
1206 static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg,
1207 struct netlink_ext_ack *extack)
1208 {
1209 struct nh_info *nhi;
1210 struct nexthop *nh;
1211 int err = 0;
1212
1213 nh = nexthop_alloc();
1214 if (!nh)
1215 return ERR_PTR(-ENOMEM);
1216
1217 nhi = kzalloc(sizeof(*nhi), GFP_KERNEL);
1218 if (!nhi) {
1219 kfree(nh);
1220 return ERR_PTR(-ENOMEM);
1221 }
1222
1223 nh->nh_flags = cfg->nh_flags;
1224 nh->net = net;
1225
1226 nhi->nh_parent = nh;
1227 nhi->family = cfg->nh_family;
1228 nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK;
1229
1230 if (cfg->nh_blackhole) {
1231 nhi->reject_nh = 1;
1232 cfg->nh_ifindex = net->loopback_dev->ifindex;
1233 }
1234
1235 switch (cfg->nh_family) {
1236 case AF_INET:
1237 err = nh_create_ipv4(net, nh, nhi, cfg, extack);
1238 break;
1239 case AF_INET6:
1240 err = nh_create_ipv6(net, nh, nhi, cfg, extack);
1241 break;
1242 }
1243
1244 if (err) {
1245 kfree(nhi);
1246 kfree(nh);
1247 return ERR_PTR(err);
1248 }
1249
1250 /* add the entry to the device based hash */
1251 nexthop_devhash_add(net, nhi);
1252
1253 rcu_assign_pointer(nh->nh_info, nhi);
1254
1255 return nh;
1256 }
1257
1258 /* called with rtnl lock held */
1259 static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg,
1260 struct netlink_ext_ack *extack)
1261 {
1262 struct nexthop *nh;
1263 int err;
1264
1265 if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) {
1266 NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
1267 return ERR_PTR(-EINVAL);
1268 }
1269
1270 if (!cfg->nh_id) {
1271 cfg->nh_id = nh_find_unused_id(net);
1272 if (!cfg->nh_id) {
1273 NL_SET_ERR_MSG(extack, "No unused id");
1274 return ERR_PTR(-EINVAL);
1275 }
1276 }
1277
1278 if (cfg->nh_grp)
1279 nh = nexthop_create_group(net, cfg);
1280 else
1281 nh = nexthop_create(net, cfg, extack);
1282
1283 if (IS_ERR(nh))
1284 return nh;
1285
1286 refcount_set(&nh->refcnt, 1);
1287 nh->id = cfg->nh_id;
1288 nh->protocol = cfg->nh_protocol;
1289 nh->net = net;
1290
1291 err = insert_nexthop(net, nh, cfg, extack);
1292 if (err) {
1293 __remove_nexthop(net, nh, NULL);
1294 nexthop_put(nh);
1295 nh = ERR_PTR(err);
1296 }
1297
1298 return nh;
1299 }
1300
1301 static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
1302 struct nlmsghdr *nlh, struct nh_config *cfg,
1303 struct netlink_ext_ack *extack)
1304 {
1305 struct nhmsg *nhm = nlmsg_data(nlh);
1306 struct nlattr *tb[NHA_MAX + 1];
1307 int err;
1308
1309 err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1310 extack);
1311 if (err < 0)
1312 return err;
1313
1314 err = -EINVAL;
1315 if (nhm->resvd || nhm->nh_scope) {
1316 NL_SET_ERR_MSG(extack, "Invalid values in ancillary header");
1317 goto out;
1318 }
1319 if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) {
1320 NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header");
1321 goto out;
1322 }
1323
1324 switch (nhm->nh_family) {
1325 case AF_INET:
1326 case AF_INET6:
1327 break;
1328 case AF_UNSPEC:
1329 if (tb[NHA_GROUP])
1330 break;
1331 fallthrough;
1332 default:
1333 NL_SET_ERR_MSG(extack, "Invalid address family");
1334 goto out;
1335 }
1336
1337 if (tb[NHA_GROUPS] || tb[NHA_MASTER]) {
1338 NL_SET_ERR_MSG(extack, "Invalid attributes in request");
1339 goto out;
1340 }
1341
1342 memset(cfg, 0, sizeof(*cfg));
1343 cfg->nlflags = nlh->nlmsg_flags;
1344 cfg->nlinfo.portid = NETLINK_CB(skb).portid;
1345 cfg->nlinfo.nlh = nlh;
1346 cfg->nlinfo.nl_net = net;
1347
1348 cfg->nh_family = nhm->nh_family;
1349 cfg->nh_protocol = nhm->nh_protocol;
1350 cfg->nh_flags = nhm->nh_flags;
1351
1352 if (tb[NHA_ID])
1353 cfg->nh_id = nla_get_u32(tb[NHA_ID]);
1354
1355 if (tb[NHA_GROUP]) {
1356 if (nhm->nh_family != AF_UNSPEC) {
1357 NL_SET_ERR_MSG(extack, "Invalid family for group");
1358 goto out;
1359 }
1360 cfg->nh_grp = tb[NHA_GROUP];
1361
1362 cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH;
1363 if (tb[NHA_GROUP_TYPE])
1364 cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]);
1365
1366 if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) {
1367 NL_SET_ERR_MSG(extack, "Invalid group type");
1368 goto out;
1369 }
1370 err = nh_check_attr_group(net, tb, extack);
1371
1372 /* no other attributes should be set */
1373 goto out;
1374 }
1375
1376 if (tb[NHA_BLACKHOLE]) {
1377 if (tb[NHA_GATEWAY] || tb[NHA_OIF] ||
1378 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) {
1379 NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway or oif");
1380 goto out;
1381 }
1382
1383 cfg->nh_blackhole = 1;
1384 err = 0;
1385 goto out;
1386 }
1387
1388 if (!tb[NHA_OIF]) {
1389 NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole nexthops");
1390 goto out;
1391 }
1392
1393 cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
1394 if (cfg->nh_ifindex)
1395 cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
1396
1397 if (!cfg->dev) {
1398 NL_SET_ERR_MSG(extack, "Invalid device index");
1399 goto out;
1400 } else if (!(cfg->dev->flags & IFF_UP)) {
1401 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
1402 err = -ENETDOWN;
1403 goto out;
1404 } else if (!netif_carrier_ok(cfg->dev)) {
1405 NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");
1406 err = -ENETDOWN;
1407 goto out;
1408 }
1409
1410 err = -EINVAL;
1411 if (tb[NHA_GATEWAY]) {
1412 struct nlattr *gwa = tb[NHA_GATEWAY];
1413
1414 switch (cfg->nh_family) {
1415 case AF_INET:
1416 if (nla_len(gwa) != sizeof(u32)) {
1417 NL_SET_ERR_MSG(extack, "Invalid gateway");
1418 goto out;
1419 }
1420 cfg->gw.ipv4 = nla_get_be32(gwa);
1421 break;
1422 case AF_INET6:
1423 if (nla_len(gwa) != sizeof(struct in6_addr)) {
1424 NL_SET_ERR_MSG(extack, "Invalid gateway");
1425 goto out;
1426 }
1427 cfg->gw.ipv6 = nla_get_in6_addr(gwa);
1428 break;
1429 default:
1430 NL_SET_ERR_MSG(extack,
1431 "Unknown address family for gateway");
1432 goto out;
1433 }
1434 } else {
1435 /* device only nexthop (no gateway) */
1436 if (cfg->nh_flags & RTNH_F_ONLINK) {
1437 NL_SET_ERR_MSG(extack,
1438 "ONLINK flag can not be set for nexthop without a gateway");
1439 goto out;
1440 }
1441 }
1442
1443 if (tb[NHA_ENCAP]) {
1444 cfg->nh_encap = tb[NHA_ENCAP];
1445
1446 if (!tb[NHA_ENCAP_TYPE]) {
1447 NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing");
1448 goto out;
1449 }
1450
1451 cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]);
1452 err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack);
1453 if (err < 0)
1454 goto out;
1455
1456 } else if (tb[NHA_ENCAP_TYPE]) {
1457 NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing");
1458 goto out;
1459 }
1460
1461
1462 err = 0;
1463 out:
1464 return err;
1465 }
1466
1467 /* rtnl */
1468 static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
1469 struct netlink_ext_ack *extack)
1470 {
1471 struct net *net = sock_net(skb->sk);
1472 struct nh_config cfg;
1473 struct nexthop *nh;
1474 int err;
1475
1476 err = rtm_to_nh_config(net, skb, nlh, &cfg, extack);
1477 if (!err) {
1478 nh = nexthop_add(net, &cfg, extack);
1479 if (IS_ERR(nh))
1480 err = PTR_ERR(nh);
1481 }
1482
1483 return err;
1484 }
1485
1486 static int nh_valid_get_del_req(struct nlmsghdr *nlh, u32 *id,
1487 struct netlink_ext_ack *extack)
1488 {
1489 struct nhmsg *nhm = nlmsg_data(nlh);
1490 struct nlattr *tb[NHA_MAX + 1];
1491 int err, i;
1492
1493 err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1494 extack);
1495 if (err < 0)
1496 return err;
1497
1498 err = -EINVAL;
1499 for (i = 0; i < __NHA_MAX; ++i) {
1500 if (!tb[i])
1501 continue;
1502
1503 switch (i) {
1504 case NHA_ID:
1505 break;
1506 default:
1507 NL_SET_ERR_MSG_ATTR(extack, tb[i],
1508 "Unexpected attribute in request");
1509 goto out;
1510 }
1511 }
1512 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
1513 NL_SET_ERR_MSG(extack, "Invalid values in header");
1514 goto out;
1515 }
1516
1517 if (!tb[NHA_ID]) {
1518 NL_SET_ERR_MSG(extack, "Nexthop id is missing");
1519 goto out;
1520 }
1521
1522 *id = nla_get_u32(tb[NHA_ID]);
1523 if (!(*id))
1524 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
1525 else
1526 err = 0;
1527 out:
1528 return err;
1529 }
1530
1531 /* rtnl */
1532 static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
1533 struct netlink_ext_ack *extack)
1534 {
1535 struct net *net = sock_net(skb->sk);
1536 struct nl_info nlinfo = {
1537 .nlh = nlh,
1538 .nl_net = net,
1539 .portid = NETLINK_CB(skb).portid,
1540 };
1541 struct nexthop *nh;
1542 int err;
1543 u32 id;
1544
1545 err = nh_valid_get_del_req(nlh, &id, extack);
1546 if (err)
1547 return err;
1548
1549 nh = nexthop_find_by_id(net, id);
1550 if (!nh)
1551 return -ENOENT;
1552
1553 remove_nexthop(net, nh, &nlinfo);
1554
1555 return 0;
1556 }
1557
1558 /* rtnl */
1559 static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh,
1560 struct netlink_ext_ack *extack)
1561 {
1562 struct net *net = sock_net(in_skb->sk);
1563 struct sk_buff *skb = NULL;
1564 struct nexthop *nh;
1565 int err;
1566 u32 id;
1567
1568 err = nh_valid_get_del_req(nlh, &id, extack);
1569 if (err)
1570 return err;
1571
1572 err = -ENOBUFS;
1573 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1574 if (!skb)
1575 goto out;
1576
1577 err = -ENOENT;
1578 nh = nexthop_find_by_id(net, id);
1579 if (!nh)
1580 goto errout_free;
1581
1582 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid,
1583 nlh->nlmsg_seq, 0);
1584 if (err < 0) {
1585 WARN_ON(err == -EMSGSIZE);
1586 goto errout_free;
1587 }
1588
1589 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
1590 out:
1591 return err;
1592 errout_free:
1593 kfree_skb(skb);
1594 goto out;
1595 }
1596
1597 static bool nh_dump_filtered(struct nexthop *nh, int dev_idx, int master_idx,
1598 bool group_filter, u8 family)
1599 {
1600 const struct net_device *dev;
1601 const struct nh_info *nhi;
1602
1603 if (group_filter && !nh->is_group)
1604 return true;
1605
1606 if (!dev_idx && !master_idx && !family)
1607 return false;
1608
1609 if (nh->is_group)
1610 return true;
1611
1612 nhi = rtnl_dereference(nh->nh_info);
1613 if (family && nhi->family != family)
1614 return true;
1615
1616 dev = nhi->fib_nhc.nhc_dev;
1617 if (dev_idx && (!dev || dev->ifindex != dev_idx))
1618 return true;
1619
1620 if (master_idx) {
1621 struct net_device *master;
1622
1623 if (!dev)
1624 return true;
1625
1626 master = netdev_master_upper_dev_get((struct net_device *)dev);
1627 if (!master || master->ifindex != master_idx)
1628 return true;
1629 }
1630
1631 return false;
1632 }
1633
1634 static int nh_valid_dump_req(const struct nlmsghdr *nlh, int *dev_idx,
1635 int *master_idx, bool *group_filter,
1636 struct netlink_callback *cb)
1637 {
1638 struct netlink_ext_ack *extack = cb->extack;
1639 struct nlattr *tb[NHA_MAX + 1];
1640 struct nhmsg *nhm;
1641 int err, i;
1642 u32 idx;
1643
1644 err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1645 NULL);
1646 if (err < 0)
1647 return err;
1648
1649 for (i = 0; i <= NHA_MAX; ++i) {
1650 if (!tb[i])
1651 continue;
1652
1653 switch (i) {
1654 case NHA_OIF:
1655 idx = nla_get_u32(tb[i]);
1656 if (idx > INT_MAX) {
1657 NL_SET_ERR_MSG(extack, "Invalid device index");
1658 return -EINVAL;
1659 }
1660 *dev_idx = idx;
1661 break;
1662 case NHA_MASTER:
1663 idx = nla_get_u32(tb[i]);
1664 if (idx > INT_MAX) {
1665 NL_SET_ERR_MSG(extack, "Invalid master device index");
1666 return -EINVAL;
1667 }
1668 *master_idx = idx;
1669 break;
1670 case NHA_GROUPS:
1671 *group_filter = true;
1672 break;
1673 default:
1674 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
1675 return -EINVAL;
1676 }
1677 }
1678
1679 nhm = nlmsg_data(nlh);
1680 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
1681 NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request");
1682 return -EINVAL;
1683 }
1684
1685 return 0;
1686 }
1687
1688 /* rtnl */
1689 static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
1690 {
1691 struct nhmsg *nhm = nlmsg_data(cb->nlh);
1692 int dev_filter_idx = 0, master_idx = 0;
1693 struct net *net = sock_net(skb->sk);
1694 struct rb_root *root = &net->nexthop.rb_root;
1695 bool group_filter = false;
1696 struct rb_node *node;
1697 int idx = 0, s_idx;
1698 int err;
1699
1700 err = nh_valid_dump_req(cb->nlh, &dev_filter_idx, &master_idx,
1701 &group_filter, cb);
1702 if (err < 0)
1703 return err;
1704
1705 s_idx = cb->args[0];
1706 for (node = rb_first(root); node; node = rb_next(node)) {
1707 struct nexthop *nh;
1708
1709 if (idx < s_idx)
1710 goto cont;
1711
1712 nh = rb_entry(node, struct nexthop, rb_node);
1713 if (nh_dump_filtered(nh, dev_filter_idx, master_idx,
1714 group_filter, nhm->nh_family))
1715 goto cont;
1716
1717 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP,
1718 NETLINK_CB(cb->skb).portid,
1719 cb->nlh->nlmsg_seq, NLM_F_MULTI);
1720 if (err < 0) {
1721 if (likely(skb->len))
1722 goto out;
1723
1724 goto out_err;
1725 }
1726 cont:
1727 idx++;
1728 }
1729
1730 out:
1731 err = skb->len;
1732 out_err:
1733 cb->args[0] = idx;
1734 cb->seq = net->nexthop.seq;
1735 nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1736
1737 return err;
1738 }
1739
1740 static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu)
1741 {
1742 unsigned int hash = nh_dev_hashfn(dev->ifindex);
1743 struct net *net = dev_net(dev);
1744 struct hlist_head *head = &net->nexthop.devhash[hash];
1745 struct hlist_node *n;
1746 struct nh_info *nhi;
1747
1748 hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
1749 if (nhi->fib_nhc.nhc_dev == dev) {
1750 if (nhi->family == AF_INET)
1751 fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu,
1752 orig_mtu);
1753 }
1754 }
1755 }
1756
1757 /* rtnl */
1758 static int nh_netdev_event(struct notifier_block *this,
1759 unsigned long event, void *ptr)
1760 {
1761 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1762 struct netdev_notifier_info_ext *info_ext;
1763
1764 switch (event) {
1765 case NETDEV_DOWN:
1766 case NETDEV_UNREGISTER:
1767 nexthop_flush_dev(dev);
1768 break;
1769 case NETDEV_CHANGE:
1770 if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP)))
1771 nexthop_flush_dev(dev);
1772 break;
1773 case NETDEV_CHANGEMTU:
1774 info_ext = ptr;
1775 nexthop_sync_mtu(dev, info_ext->ext.mtu);
1776 rt_cache_flush(dev_net(dev));
1777 break;
1778 }
1779 return NOTIFY_DONE;
1780 }
1781
1782 static struct notifier_block nh_netdev_notifier = {
1783 .notifier_call = nh_netdev_event,
1784 };
1785
1786 static void __net_exit nexthop_net_exit(struct net *net)
1787 {
1788 rtnl_lock();
1789 flush_all_nexthops(net);
1790 rtnl_unlock();
1791 kfree(net->nexthop.devhash);
1792 }
1793
1794 static int __net_init nexthop_net_init(struct net *net)
1795 {
1796 size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE;
1797
1798 net->nexthop.rb_root = RB_ROOT;
1799 net->nexthop.devhash = kzalloc(sz, GFP_KERNEL);
1800 if (!net->nexthop.devhash)
1801 return -ENOMEM;
1802
1803 return 0;
1804 }
1805
1806 static struct pernet_operations nexthop_net_ops = {
1807 .init = nexthop_net_init,
1808 .exit = nexthop_net_exit,
1809 };
1810
1811 static int __init nexthop_init(void)
1812 {
1813 register_pernet_subsys(&nexthop_net_ops);
1814
1815 register_netdevice_notifier(&nh_netdev_notifier);
1816
1817 rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
1818 rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0);
1819 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop,
1820 rtm_dump_nexthop, 0);
1821
1822 rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
1823 rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
1824
1825 rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
1826 rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
1827
1828 return 0;
1829 }
1830 subsys_initcall(nexthop_init);
Linux with added FPC-III support