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ALSA: hda - Update descriptions about new position_fix values
[linux-2.6-block.git] / net / ipv4 / nexthop.c
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ab84be7e
DA		 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>
430a0491 11#include <net/arp.h>
53010f99 12#include <net/ipv6_stubs.h>
b513bd03 13#include <net/lwtunnel.h>
430a0491 14#include <net/ndisc.h>
ab84be7e 15#include <net/nexthop.h>
597cfe4f 16#include <net/route.h>
ab84be7e
DA		 17#include <net/sock.h>
18
430a0491
DA		 19static void remove_nexthop(struct net *net, struct nexthop *nh,
20 struct nl_info *nlinfo);
21
597cfe4f
DA		 22#define NH_DEV_HASHBITS 8
23#define NH_DEV_HASHSIZE (1U << NH_DEV_HASHBITS)
24
ab84be7e
DA		 25static const struct nla_policy rtm_nh_policy[NHA_MAX + 1] = {
26 [NHA_UNSPEC] = { .strict_start_type = NHA_UNSPEC + 1 },
27 [NHA_ID] = { .type = NLA_U32 },
28 [NHA_GROUP] = { .type = NLA_BINARY },
29 [NHA_GROUP_TYPE] = { .type = NLA_U16 },
30 [NHA_BLACKHOLE] = { .type = NLA_FLAG },
31 [NHA_OIF] = { .type = NLA_U32 },
32 [NHA_GATEWAY] = { .type = NLA_BINARY },
33 [NHA_ENCAP_TYPE] = { .type = NLA_U16 },
34 [NHA_ENCAP] = { .type = NLA_NESTED },
35 [NHA_GROUPS] = { .type = NLA_FLAG },
36 [NHA_MASTER] = { .type = NLA_U32 },
37};
38
597cfe4f
DA		 39static unsigned int nh_dev_hashfn(unsigned int val)
40{
41 unsigned int mask = NH_DEV_HASHSIZE - 1;
42
43 return (val ^
44 (val >> NH_DEV_HASHBITS) ^
45 (val >> (NH_DEV_HASHBITS * 2))) & mask;
46}
47
48static void nexthop_devhash_add(struct net *net, struct nh_info *nhi)
49{
50 struct net_device *dev = nhi->fib_nhc.nhc_dev;
51 struct hlist_head *head;
52 unsigned int hash;
53
54 WARN_ON(!dev);
55
56 hash = nh_dev_hashfn(dev->ifindex);
57 head = &net->nexthop.devhash[hash];
58 hlist_add_head(&nhi->dev_hash, head);
59}
60
430a0491
DA		 61static void nexthop_free_mpath(struct nexthop *nh)
62{
63 struct nh_group *nhg;
64 int i;
65
66 nhg = rcu_dereference_raw(nh->nh_grp);
67 for (i = 0; i < nhg->num_nh; ++i)
68 WARN_ON(nhg->nh_entries[i].nh);
69
70 kfree(nhg);
71}
72
73static void nexthop_free_single(struct nexthop *nh)
ab84be7e 74{
ab84be7e
DA		 75 struct nh_info *nhi;
76
77 nhi = rcu_dereference_raw(nh->nh_info);
597cfe4f
DA		 78 switch (nhi->family) {
79 case AF_INET:
80 fib_nh_release(nh->net, &nhi->fib_nh);
81 break;
53010f99
DA		 82 case AF_INET6:
83 ipv6_stub->fib6_nh_release(&nhi->fib6_nh);
84 break;
597cfe4f 85 }
ab84be7e 86 kfree(nhi);
430a0491
DA		 87}
88
89void nexthop_free_rcu(struct rcu_head *head)
90{
91 struct nexthop *nh = container_of(head, struct nexthop, rcu);
92
93 if (nh->is_group)
94 nexthop_free_mpath(nh);
95 else
96 nexthop_free_single(nh);
ab84be7e
DA		 97
98 kfree(nh);
99}
100EXPORT_SYMBOL_GPL(nexthop_free_rcu);
101
102static struct nexthop *nexthop_alloc(void)
103{
104 struct nexthop *nh;
105
106 nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL);
430a0491 107 if (nh) {
4c7e8084 108 INIT_LIST_HEAD(&nh->fi_list);
f88d8ea6 109 INIT_LIST_HEAD(&nh->f6i_list);
430a0491
DA		 110 INIT_LIST_HEAD(&nh->grp_list);
111 }
ab84be7e
DA		 112 return nh;
113}
114
430a0491
DA		 115static struct nh_group *nexthop_grp_alloc(u16 num_nh)
116{
117 size_t sz = offsetof(struct nexthop, nh_grp)
118 + sizeof(struct nh_group)
119 + sizeof(struct nh_grp_entry) * num_nh;
120 struct nh_group *nhg;
121
122 nhg = kzalloc(sz, GFP_KERNEL);
123 if (nhg)
124 nhg->num_nh = num_nh;
125
126 return nhg;
127}
128
ab84be7e
DA		 129static void nh_base_seq_inc(struct net *net)
130{
131 while (++net->nexthop.seq == 0)
132 ;
133}
134
135/* no reference taken; rcu lock or rtnl must be held */
136struct nexthop *nexthop_find_by_id(struct net *net, u32 id)
137{
138 struct rb_node **pp, *parent = NULL, *next;
139
140 pp = &net->nexthop.rb_root.rb_node;
141 while (1) {
142 struct nexthop *nh;
143
144 next = rcu_dereference_raw(*pp);
145 if (!next)
146 break;
147 parent = next;
148
149 nh = rb_entry(parent, struct nexthop, rb_node);
150 if (id < nh->id)
151 pp = &next->rb_left;
152 else if (id > nh->id)
153 pp = &next->rb_right;
154 else
155 return nh;
156 }
157 return NULL;
158}
159EXPORT_SYMBOL_GPL(nexthop_find_by_id);
160
161/* used for auto id allocation; called with rtnl held */
162static u32 nh_find_unused_id(struct net *net)
163{
164 u32 id_start = net->nexthop.last_id_allocated;
165
166 while (1) {
167 net->nexthop.last_id_allocated++;
168 if (net->nexthop.last_id_allocated == id_start)
169 break;
170
171 if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated))
172 return net->nexthop.last_id_allocated;
173 }
174 return 0;
175}
176
430a0491
DA		 177static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg)
178{
179 struct nexthop_grp *p;
180 size_t len = nhg->num_nh * sizeof(*p);
181 struct nlattr *nla;
182 u16 group_type = 0;
183 int i;
184
185 if (nhg->mpath)
186 group_type = NEXTHOP_GRP_TYPE_MPATH;
187
188 if (nla_put_u16(skb, NHA_GROUP_TYPE, group_type))
189 goto nla_put_failure;
190
191 nla = nla_reserve(skb, NHA_GROUP, len);
192 if (!nla)
193 goto nla_put_failure;
194
195 p = nla_data(nla);
196 for (i = 0; i < nhg->num_nh; ++i) {
197 p->id = nhg->nh_entries[i].nh->id;
198 p->weight = nhg->nh_entries[i].weight - 1;
199 p += 1;
200 }
201
202 return 0;
203
204nla_put_failure:
205 return -EMSGSIZE;
206}
207
ab84be7e
DA		 208static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh,
209 int event, u32 portid, u32 seq, unsigned int nlflags)
210{
53010f99 211 struct fib6_nh *fib6_nh;
597cfe4f 212 struct fib_nh *fib_nh;
ab84be7e
DA		 213 struct nlmsghdr *nlh;
214 struct nh_info *nhi;
215 struct nhmsg *nhm;
216
217 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
218 if (!nlh)
219 return -EMSGSIZE;
220
221 nhm = nlmsg_data(nlh);
222 nhm->nh_family = AF_UNSPEC;
223 nhm->nh_flags = nh->nh_flags;
224 nhm->nh_protocol = nh->protocol;
225 nhm->nh_scope = 0;
226 nhm->resvd = 0;
227
228 if (nla_put_u32(skb, NHA_ID, nh->id))
229 goto nla_put_failure;
230
430a0491
DA		 231 if (nh->is_group) {
232 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
233
234 if (nla_put_nh_group(skb, nhg))
235 goto nla_put_failure;
236 goto out;
237 }
238
ab84be7e
DA		 239 nhi = rtnl_dereference(nh->nh_info);
240 nhm->nh_family = nhi->family;
241 if (nhi->reject_nh) {
242 if (nla_put_flag(skb, NHA_BLACKHOLE))
243 goto nla_put_failure;
244 goto out;
597cfe4f
DA		 245 } else {
246 const struct net_device *dev;
247
248 dev = nhi->fib_nhc.nhc_dev;
249 if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex))
250 goto nla_put_failure;
251 }
252
253 nhm->nh_scope = nhi->fib_nhc.nhc_scope;
254 switch (nhi->family) {
255 case AF_INET:
256 fib_nh = &nhi->fib_nh;
257 if (fib_nh->fib_nh_gw_family &&
258 nla_put_u32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4))
259 goto nla_put_failure;
260 break;
53010f99
DA		 261
262 case AF_INET6:
263 fib6_nh = &nhi->fib6_nh;
264 if (fib6_nh->fib_nh_gw_family &&
265 nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->fib_nh_gw6))
266 goto nla_put_failure;
267 break;
ab84be7e
DA		 268 }
269
b513bd03
DA		 270 if (nhi->fib_nhc.nhc_lwtstate &&
271 lwtunnel_fill_encap(skb, nhi->fib_nhc.nhc_lwtstate,
272 NHA_ENCAP, NHA_ENCAP_TYPE) < 0)
273 goto nla_put_failure;
274
ab84be7e
DA		 275out:
276 nlmsg_end(skb, nlh);
277 return 0;
278
279nla_put_failure:
280 return -EMSGSIZE;
281}
282
430a0491
DA		 283static size_t nh_nlmsg_size_grp(struct nexthop *nh)
284{
285 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
286 size_t sz = sizeof(struct nexthop_grp) * nhg->num_nh;
287
288 return nla_total_size(sz) +
289 nla_total_size(2); /* NHA_GROUP_TYPE */
290}
291
292static size_t nh_nlmsg_size_single(struct nexthop *nh)
ab84be7e 293{
597cfe4f 294 struct nh_info *nhi = rtnl_dereference(nh->nh_info);
430a0491 295 size_t sz;
ab84be7e
DA		 296
297 /* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE
298 * are mutually exclusive
299 */
430a0491 300 sz = nla_total_size(4); /* NHA_OIF */
ab84be7e 301
597cfe4f
DA		 302 switch (nhi->family) {
303 case AF_INET:
304 if (nhi->fib_nh.fib_nh_gw_family)
305 sz += nla_total_size(4); /* NHA_GATEWAY */
306 break;
53010f99
DA		 307
308 case AF_INET6:
309 /* NHA_GATEWAY */
310 if (nhi->fib6_nh.fib_nh_gw_family)
311 sz += nla_total_size(sizeof(const struct in6_addr));
312 break;
597cfe4f
DA		 313 }
314
b513bd03
DA		 315 if (nhi->fib_nhc.nhc_lwtstate) {
316 sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate);
317 sz += nla_total_size(2); /* NHA_ENCAP_TYPE */
318 }
319
ab84be7e
DA		 320 return sz;
321}
322
430a0491
DA		 323static size_t nh_nlmsg_size(struct nexthop *nh)
324{
325 size_t sz = nla_total_size(4); /* NHA_ID */
326
327 if (nh->is_group)
328 sz += nh_nlmsg_size_grp(nh);
329 else
330 sz += nh_nlmsg_size_single(nh);
331
332 return sz;
333}
334
ab84be7e
DA		 335static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info)
336{
337 unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0;
338 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
339 struct sk_buff *skb;
340 int err = -ENOBUFS;
341
342 skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any());
343 if (!skb)
344 goto errout;
345
346 err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags);
347 if (err < 0) {
348 /* -EMSGSIZE implies BUG in nh_nlmsg_size() */
349 WARN_ON(err == -EMSGSIZE);
350 kfree_skb(skb);
351 goto errout;
352 }
353
354 rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_NEXTHOP,
355 info->nlh, gfp_any());
356 return;
357errout:
358 if (err < 0)
359 rtnl_set_sk_err(info->nl_net, RTNLGRP_NEXTHOP, err);
360}
361
430a0491
DA		 362static bool valid_group_nh(struct nexthop *nh, unsigned int npaths,
363 struct netlink_ext_ack *extack)
597cfe4f 364{
430a0491
DA		 365 if (nh->is_group) {
366 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
597cfe4f 367
430a0491
DA		 368 /* nested multipath (group within a group) is not
369 * supported
370 */
371 if (nhg->mpath) {
372 NL_SET_ERR_MSG(extack,
373 "Multipath group can not be a nexthop within a group");
374 return false;
375 }
376 } else {
377 struct nh_info *nhi = rtnl_dereference(nh->nh_info);
378
379 if (nhi->reject_nh && npaths > 1) {
380 NL_SET_ERR_MSG(extack,
381 "Blackhole nexthop can not be used in a group with more than 1 path");
382 return false;
383 }
384 }
385
386 return true;
387}
388
389static int nh_check_attr_group(struct net *net, struct nlattr *tb[],
390 struct netlink_ext_ack *extack)
391{
392 unsigned int len = nla_len(tb[NHA_GROUP]);
393 struct nexthop_grp *nhg;
394 unsigned int i, j;
395
396 if (len & (sizeof(struct nexthop_grp) - 1)) {
397 NL_SET_ERR_MSG(extack,
398 "Invalid length for nexthop group attribute");
399 return -EINVAL;
400 }
401
402 /* convert len to number of nexthop ids */
403 len /= sizeof(*nhg);
404
405 nhg = nla_data(tb[NHA_GROUP]);
406 for (i = 0; i < len; ++i) {
407 if (nhg[i].resvd1 || nhg[i].resvd2) {
408 NL_SET_ERR_MSG(extack, "Reserved fields in nexthop_grp must be 0");
409 return -EINVAL;
410 }
411 if (nhg[i].weight > 254) {
412 NL_SET_ERR_MSG(extack, "Invalid value for weight");
413 return -EINVAL;
414 }
415 for (j = i + 1; j < len; ++j) {
416 if (nhg[i].id == nhg[j].id) {
417 NL_SET_ERR_MSG(extack, "Nexthop id can not be used twice in a group");
418 return -EINVAL;
419 }
420 }
421 }
422
423 nhg = nla_data(tb[NHA_GROUP]);
424 for (i = 0; i < len; ++i) {
425 struct nexthop *nh;
426
427 nh = nexthop_find_by_id(net, nhg[i].id);
428 if (!nh) {
429 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
430 return -EINVAL;
431 }
432 if (!valid_group_nh(nh, len, extack))
433 return -EINVAL;
434 }
435 for (i = NHA_GROUP + 1; i < __NHA_MAX; ++i) {
436 if (!tb[i])
437 continue;
438
439 NL_SET_ERR_MSG(extack,
440 "No other attributes can be set in nexthop groups");
441 return -EINVAL;
442 }
443
444 return 0;
445}
446
447static bool ipv6_good_nh(const struct fib6_nh *nh)
448{
449 int state = NUD_REACHABLE;
450 struct neighbour *n;
451
452 rcu_read_lock_bh();
453
454 n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6);
455 if (n)
456 state = n->nud_state;
457
458 rcu_read_unlock_bh();
459
460 return !!(state & NUD_VALID);
461}
462
463static bool ipv4_good_nh(const struct fib_nh *nh)
464{
465 int state = NUD_REACHABLE;
466 struct neighbour *n;
467
468 rcu_read_lock_bh();
469
470 n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev,
471 (__force u32)nh->fib_nh_gw4);
472 if (n)
473 state = n->nud_state;
474
475 rcu_read_unlock_bh();
476
477 return !!(state & NUD_VALID);
478}
479
480struct nexthop *nexthop_select_path(struct nexthop *nh, int hash)
481{
482 struct nexthop *rc = NULL;
483 struct nh_group *nhg;
484 int i;
485
486 if (!nh->is_group)
487 return nh;
488
489 nhg = rcu_dereference(nh->nh_grp);
490 for (i = 0; i < nhg->num_nh; ++i) {
491 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
492 struct nh_info *nhi;
493
494 if (hash > atomic_read(&nhge->upper_bound))
495 continue;
496
497 /* nexthops always check if it is good and does
498 * not rely on a sysctl for this behavior
499 */
500 nhi = rcu_dereference(nhge->nh->nh_info);
501 switch (nhi->family) {
502 case AF_INET:
503 if (ipv4_good_nh(&nhi->fib_nh))
504 return nhge->nh;
505 break;
506 case AF_INET6:
507 if (ipv6_good_nh(&nhi->fib6_nh))
508 return nhge->nh;
509 break;
510 }
511
512 if (!rc)
513 rc = nhge->nh;
514 }
515
516 return rc;
517}
518EXPORT_SYMBOL_GPL(nexthop_select_path);
519
f88c9aa1
DA		 520int nexthop_for_each_fib6_nh(struct nexthop *nh,
521 int (*cb)(struct fib6_nh *nh, void *arg),
522 void *arg)
523{
524 struct nh_info *nhi;
525 int err;
526
527 if (nh->is_group) {
528 struct nh_group *nhg;
529 int i;
530
531 nhg = rcu_dereference_rtnl(nh->nh_grp);
532 for (i = 0; i < nhg->num_nh; i++) {
533 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
534
535 nhi = rcu_dereference_rtnl(nhge->nh->nh_info);
536 err = cb(&nhi->fib6_nh, arg);
537 if (err)
538 return err;
539 }
540 } else {
541 nhi = rcu_dereference_rtnl(nh->nh_info);
542 err = cb(&nhi->fib6_nh, arg);
543 if (err)
544 return err;
545 }
546
547 return 0;
548}
549EXPORT_SYMBOL_GPL(nexthop_for_each_fib6_nh);
550
7bf4796d
DA		 551static int check_src_addr(const struct in6_addr *saddr,
552 struct netlink_ext_ack *extack)
553{
554 if (!ipv6_addr_any(saddr)) {
555 NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects");
556 return -EINVAL;
557 }
558 return 0;
559}
560
f88d8ea6
DA		 561int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
562 struct netlink_ext_ack *extack)
563{
564 struct nh_info *nhi;
565
566 /* fib6_src is unique to a fib6_info and limits the ability to cache
567 * routes in fib6_nh within a nexthop that is potentially shared
568 * across multiple fib entries. If the config wants to use source
569 * routing it can not use nexthop objects. mlxsw also does not allow
570 * fib6_src on routes.
571 */
7bf4796d 572 if (cfg && check_src_addr(&cfg->fc_src, extack) < 0)
f88d8ea6 573 return -EINVAL;
f88d8ea6
DA		 574
575 if (nh->is_group) {
576 struct nh_group *nhg;
577
578 nhg = rtnl_dereference(nh->nh_grp);
579 if (nhg->has_v4)
580 goto no_v4_nh;
581 } else {
582 nhi = rtnl_dereference(nh->nh_info);
583 if (nhi->family == AF_INET)
584 goto no_v4_nh;
585 }
586
587 return 0;
588no_v4_nh:
589 NL_SET_ERR_MSG(extack, "IPv6 routes can not use an IPv4 nexthop");
590 return -EINVAL;
591}
592EXPORT_SYMBOL_GPL(fib6_check_nexthop);
593
7bf4796d
DA		 594/* if existing nexthop has ipv6 routes linked to it, need
595 * to verify this new spec works with ipv6
596 */
597static int fib6_check_nh_list(struct nexthop *old, struct nexthop *new,
598 struct netlink_ext_ack *extack)
599{
600 struct fib6_info *f6i;
601
602 if (list_empty(&old->f6i_list))
603 return 0;
604
605 list_for_each_entry(f6i, &old->f6i_list, nh_list) {
606 if (check_src_addr(&f6i->fib6_src.addr, extack) < 0)
607 return -EINVAL;
608 }
609
610 return fib6_check_nexthop(new, NULL, extack);
611}
612
4c7e8084
DA		 613static int nexthop_check_scope(struct nexthop *nh, u8 scope,
614 struct netlink_ext_ack *extack)
615{
616 struct nh_info *nhi;
617
618 nhi = rtnl_dereference(nh->nh_info);
619 if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) {
620 NL_SET_ERR_MSG(extack,
621 "Route with host scope can not have a gateway");
622 return -EINVAL;
623 }
624
625 if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) {
626 NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop");
627 return -EINVAL;
628 }
629
630 return 0;
631}
632
633/* Invoked by fib add code to verify nexthop by id is ok with
634 * config for prefix; parts of fib_check_nh not done when nexthop
635 * object is used.
636 */
637int fib_check_nexthop(struct nexthop *nh, u8 scope,
638 struct netlink_ext_ack *extack)
639{
640 int err = 0;
641
642 if (nh->is_group) {
643 struct nh_group *nhg;
644
645 if (scope == RT_SCOPE_HOST) {
646 NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops");
647 err = -EINVAL;
648 goto out;
649 }
650
651 nhg = rtnl_dereference(nh->nh_grp);
652 /* all nexthops in a group have the same scope */
653 err = nexthop_check_scope(nhg->nh_entries[0].nh, scope, extack);
654 } else {
655 err = nexthop_check_scope(nh, scope, extack);
656 }
657out:
658 return err;
659}
660
7bf4796d
DA		 661static int fib_check_nh_list(struct nexthop *old, struct nexthop *new,
662 struct netlink_ext_ack *extack)
663{
664 struct fib_info *fi;
665
666 list_for_each_entry(fi, &old->fi_list, nh_list) {
667 int err;
668
669 err = fib_check_nexthop(new, fi->fib_scope, extack);
670 if (err)
671 return err;
672 }
673 return 0;
674}
675
430a0491
DA		 676static void nh_group_rebalance(struct nh_group *nhg)
677{
678 int total = 0;
679 int w = 0;
680 int i;
681
682 for (i = 0; i < nhg->num_nh; ++i)
683 total += nhg->nh_entries[i].weight;
684
685 for (i = 0; i < nhg->num_nh; ++i) {
686 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
687 int upper_bound;
688
689 w += nhge->weight;
690 upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, total) - 1;
691 atomic_set(&nhge->upper_bound, upper_bound);
692 }
693}
694
695static void remove_nh_grp_entry(struct nh_grp_entry *nhge,
696 struct nh_group *nhg,
697 struct nl_info *nlinfo)
698{
699 struct nexthop *nh = nhge->nh;
700 struct nh_grp_entry *nhges;
701 bool found = false;
702 int i;
703
704 WARN_ON(!nh);
705
706 nhges = nhg->nh_entries;
707 for (i = 0; i < nhg->num_nh; ++i) {
708 if (found) {
709 nhges[i-1].nh = nhges[i].nh;
710 nhges[i-1].weight = nhges[i].weight;
711 list_del(&nhges[i].nh_list);
712 list_add(&nhges[i-1].nh_list, &nhges[i-1].nh->grp_list);
713 } else if (nhg->nh_entries[i].nh == nh) {
714 found = true;
715 }
716 }
717
718 if (WARN_ON(!found))
719 return;
720
721 nhg->num_nh--;
722 nhg->nh_entries[nhg->num_nh].nh = NULL;
723
724 nh_group_rebalance(nhg);
725
726 nexthop_put(nh);
727
728 if (nlinfo)
729 nexthop_notify(RTM_NEWNEXTHOP, nhge->nh_parent, nlinfo);
730}
731
732static void remove_nexthop_from_groups(struct net *net, struct nexthop *nh,
733 struct nl_info *nlinfo)
734{
735 struct nh_grp_entry *nhge, *tmp;
736
737 list_for_each_entry_safe(nhge, tmp, &nh->grp_list, nh_list) {
738 struct nh_group *nhg;
739
740 list_del(&nhge->nh_list);
741 nhg = rtnl_dereference(nhge->nh_parent->nh_grp);
742 remove_nh_grp_entry(nhge, nhg, nlinfo);
743
744 /* if this group has no more entries then remove it */
745 if (!nhg->num_nh)
746 remove_nexthop(net, nhge->nh_parent, nlinfo);
747 }
748}
749
750static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo)
751{
752 struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp);
753 int i, num_nh = nhg->num_nh;
754
755 for (i = 0; i < num_nh; ++i) {
756 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
757
758 if (WARN_ON(!nhge->nh))
759 continue;
760
761 list_del(&nhge->nh_list);
762 nexthop_put(nhge->nh);
763 nhge->nh = NULL;
764 nhg->num_nh--;
765 }
766}
767
7bf4796d 768/* not called for nexthop replace */
4c7e8084
DA		 769static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
770{
f88d8ea6 771 struct fib6_info *f6i, *tmp;
4c7e8084
DA		 772 bool do_flush = false;
773 struct fib_info *fi;
774
775 list_for_each_entry(fi, &nh->fi_list, nh_list) {
776 fi->fib_flags |= RTNH_F_DEAD;
777 do_flush = true;
778 }
779 if (do_flush)
780 fib_flush(net);
f88d8ea6
DA		 781
782 /* ip6_del_rt removes the entry from this list hence the _safe */
783 list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) {
784 /* __ip6_del_rt does a release, so do a hold here */
785 fib6_info_hold(f6i);
786 ipv6_stub->ip6_del_rt(net, f6i);
787 }
4c7e8084
DA		 788}
789
430a0491
DA		 790static void __remove_nexthop(struct net *net, struct nexthop *nh,
791 struct nl_info *nlinfo)
792{
4c7e8084
DA		 793 __remove_nexthop_fib(net, nh);
794
430a0491
DA		 795 if (nh->is_group) {
796 remove_nexthop_group(nh, nlinfo);
797 } else {
798 struct nh_info *nhi;
799
800 nhi = rtnl_dereference(nh->nh_info);
801 if (nhi->fib_nhc.nhc_dev)
802 hlist_del(&nhi->dev_hash);
803
804 remove_nexthop_from_groups(net, nh, nlinfo);
805 }
597cfe4f
DA		 806}
807
ab84be7e 808static void remove_nexthop(struct net *net, struct nexthop *nh,
430a0491 809 struct nl_info *nlinfo)
ab84be7e
DA		 810{
811 /* remove from the tree */
812 rb_erase(&nh->rb_node, &net->nexthop.rb_root);
813
814 if (nlinfo)
815 nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo);
816
430a0491 817 __remove_nexthop(net, nh, nlinfo);
ab84be7e
DA		 818 nh_base_seq_inc(net);
819
820 nexthop_put(nh);
821}
822
7bf4796d
DA		 823/* if any FIB entries reference this nexthop, any dst entries
824 * need to be regenerated
825 */
826static void nh_rt_cache_flush(struct net *net, struct nexthop *nh)
827{
828 struct fib6_info *f6i;
829
830 if (!list_empty(&nh->fi_list))
831 rt_cache_flush(net);
832
833 list_for_each_entry(f6i, &nh->f6i_list, nh_list)
834 ipv6_stub->fib6_update_sernum(net, f6i);
835}
836
837static int replace_nexthop_grp(struct net *net, struct nexthop *old,
838 struct nexthop *new,
839 struct netlink_ext_ack *extack)
840{
841 struct nh_group *oldg, *newg;
842 int i;
843
844 if (!new->is_group) {
845 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop.");
846 return -EINVAL;
847 }
848
849 oldg = rtnl_dereference(old->nh_grp);
850 newg = rtnl_dereference(new->nh_grp);
851
852 /* update parents - used by nexthop code for cleanup */
853 for (i = 0; i < newg->num_nh; i++)
854 newg->nh_entries[i].nh_parent = old;
855
856 rcu_assign_pointer(old->nh_grp, newg);
857
858 for (i = 0; i < oldg->num_nh; i++)
859 oldg->nh_entries[i].nh_parent = new;
860
861 rcu_assign_pointer(new->nh_grp, oldg);
862
863 return 0;
864}
865
866static int replace_nexthop_single(struct net *net, struct nexthop *old,
867 struct nexthop *new,
868 struct netlink_ext_ack *extack)
869{
870 struct nh_info *oldi, *newi;
871
872 if (new->is_group) {
873 NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group.");
874 return -EINVAL;
875 }
876
877 oldi = rtnl_dereference(old->nh_info);
878 newi = rtnl_dereference(new->nh_info);
879
880 newi->nh_parent = old;
881 oldi->nh_parent = new;
882
883 old->protocol = new->protocol;
884 old->nh_flags = new->nh_flags;
885
886 rcu_assign_pointer(old->nh_info, newi);
887 rcu_assign_pointer(new->nh_info, oldi);
888
889 return 0;
890}
891
892static void __nexthop_replace_notify(struct net *net, struct nexthop *nh,
893 struct nl_info *info)
894{
895 struct fib6_info *f6i;
896
897 if (!list_empty(&nh->fi_list)) {
898 struct fib_info *fi;
899
900 /* expectation is a few fib_info per nexthop and then
901 * a lot of routes per fib_info. So mark the fib_info
902 * and then walk the fib tables once
903 */
904 list_for_each_entry(fi, &nh->fi_list, nh_list)
905 fi->nh_updated = true;
906
907 fib_info_notify_update(net, info);
908
909 list_for_each_entry(fi, &nh->fi_list, nh_list)
910 fi->nh_updated = false;
911 }
912
913 list_for_each_entry(f6i, &nh->f6i_list, nh_list)
914 ipv6_stub->fib6_rt_update(net, f6i, info);
915}
916
917/* send RTM_NEWROUTE with REPLACE flag set for all FIB entries
918 * linked to this nexthop and for all groups that the nexthop
919 * is a member of
920 */
921static void nexthop_replace_notify(struct net *net, struct nexthop *nh,
922 struct nl_info *info)
923{
924 struct nh_grp_entry *nhge;
925
926 __nexthop_replace_notify(net, nh, info);
927
928 list_for_each_entry(nhge, &nh->grp_list, nh_list)
929 __nexthop_replace_notify(net, nhge->nh_parent, info);
930}
931
ab84be7e
DA		 932static int replace_nexthop(struct net *net, struct nexthop *old,
933 struct nexthop *new, struct netlink_ext_ack *extack)
934{
7bf4796d
DA		 935 bool new_is_reject = false;
936 struct nh_grp_entry *nhge;
937 int err;
938
939 /* check that existing FIB entries are ok with the
940 * new nexthop definition
941 */
942 err = fib_check_nh_list(old, new, extack);
943 if (err)
944 return err;
945
946 err = fib6_check_nh_list(old, new, extack);
947 if (err)
948 return err;
949
950 if (!new->is_group) {
951 struct nh_info *nhi = rtnl_dereference(new->nh_info);
952
953 new_is_reject = nhi->reject_nh;
954 }
955
956 list_for_each_entry(nhge, &old->grp_list, nh_list) {
957 /* if new nexthop is a blackhole, any groups using this
958 * nexthop cannot have more than 1 path
959 */
960 if (new_is_reject &&
961 nexthop_num_path(nhge->nh_parent) > 1) {
962 NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path");
963 return -EINVAL;
964 }
965
966 err = fib_check_nh_list(nhge->nh_parent, new, extack);
967 if (err)
968 return err;
969
970 err = fib6_check_nh_list(nhge->nh_parent, new, extack);
971 if (err)
972 return err;
973 }
974
975 if (old->is_group)
976 err = replace_nexthop_grp(net, old, new, extack);
977 else
978 err = replace_nexthop_single(net, old, new, extack);
979
980 if (!err) {
981 nh_rt_cache_flush(net, old);
982
983 __remove_nexthop(net, new, NULL);
984 nexthop_put(new);
985 }
986
987 return err;
ab84be7e
DA		 988}
989
990/* called with rtnl_lock held */
991static int insert_nexthop(struct net *net, struct nexthop *new_nh,
992 struct nh_config *cfg, struct netlink_ext_ack *extack)
993{
994 struct rb_node **pp, *parent = NULL, *next;
995 struct rb_root *root = &net->nexthop.rb_root;
996 bool replace = !!(cfg->nlflags & NLM_F_REPLACE);
997 bool create = !!(cfg->nlflags & NLM_F_CREATE);
998 u32 new_id = new_nh->id;
7bf4796d 999 int replace_notify = 0;
ab84be7e
DA		 1000 int rc = -EEXIST;
1001
1002 pp = &root->rb_node;
1003 while (1) {
1004 struct nexthop *nh;
1005
1006 next = rtnl_dereference(*pp);
1007 if (!next)
1008 break;
1009
1010 parent = next;
1011
1012 nh = rb_entry(parent, struct nexthop, rb_node);
1013 if (new_id < nh->id) {
1014 pp = &next->rb_left;
1015 } else if (new_id > nh->id) {
1016 pp = &next->rb_right;
1017 } else if (replace) {
1018 rc = replace_nexthop(net, nh, new_nh, extack);
7bf4796d 1019 if (!rc) {
ab84be7e 1020 new_nh = nh; /* send notification with old nh */
7bf4796d
DA		 1021 replace_notify = 1;
1022 }
ab84be7e
DA		 1023 goto out;
1024 } else {
1025 /* id already exists and not a replace */
1026 goto out;
1027 }
1028 }
1029
1030 if (replace && !create) {
1031 NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists");
1032 rc = -ENOENT;
1033 goto out;
1034 }
1035
1036 rb_link_node_rcu(&new_nh->rb_node, parent, pp);
1037 rb_insert_color(&new_nh->rb_node, root);
1038 rc = 0;
1039out:
1040 if (!rc) {
1041 nh_base_seq_inc(net);
1042 nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo);
7bf4796d
DA		 1043 if (replace_notify)
1044 nexthop_replace_notify(net, new_nh, &cfg->nlinfo);
ab84be7e
DA		 1045 }
1046
1047 return rc;
1048}
1049
597cfe4f
DA		 1050/* rtnl */
1051/* remove all nexthops tied to a device being deleted */
1052static void nexthop_flush_dev(struct net_device *dev)
1053{
1054 unsigned int hash = nh_dev_hashfn(dev->ifindex);
1055 struct net *net = dev_net(dev);
1056 struct hlist_head *head = &net->nexthop.devhash[hash];
1057 struct hlist_node *n;
1058 struct nh_info *nhi;
1059
1060 hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
1061 if (nhi->fib_nhc.nhc_dev != dev)
1062 continue;
1063
430a0491 1064 remove_nexthop(net, nhi->nh_parent, NULL);
597cfe4f
DA		 1065 }
1066}
1067
ab84be7e
DA		 1068/* rtnl; called when net namespace is deleted */
1069static void flush_all_nexthops(struct net *net)
1070{
1071 struct rb_root *root = &net->nexthop.rb_root;
1072 struct rb_node *node;
1073 struct nexthop *nh;
1074
1075 while ((node = rb_first(root))) {
1076 nh = rb_entry(node, struct nexthop, rb_node);
430a0491 1077 remove_nexthop(net, nh, NULL);
ab84be7e
DA		 1078 cond_resched();
1079 }
1080}
1081
430a0491
DA		 1082static struct nexthop *nexthop_create_group(struct net *net,
1083 struct nh_config *cfg)
1084{
1085 struct nlattr *grps_attr = cfg->nh_grp;
1086 struct nexthop_grp *entry = nla_data(grps_attr);
1087 struct nh_group *nhg;
1088 struct nexthop *nh;
1089 int i;
1090
1091 nh = nexthop_alloc();
1092 if (!nh)
1093 return ERR_PTR(-ENOMEM);
1094
1095 nh->is_group = 1;
1096
1097 nhg = nexthop_grp_alloc(nla_len(grps_attr) / sizeof(*entry));
1098 if (!nhg) {
1099 kfree(nh);
1100 return ERR_PTR(-ENOMEM);
1101 }
1102
1103 for (i = 0; i < nhg->num_nh; ++i) {
1104 struct nexthop *nhe;
1105 struct nh_info *nhi;
1106
1107 nhe = nexthop_find_by_id(net, entry[i].id);
1108 if (!nexthop_get(nhe))
1109 goto out_no_nh;
1110
1111 nhi = rtnl_dereference(nhe->nh_info);
1112 if (nhi->family == AF_INET)
1113 nhg->has_v4 = true;
1114
1115 nhg->nh_entries[i].nh = nhe;
1116 nhg->nh_entries[i].weight = entry[i].weight + 1;
1117 list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list);
1118 nhg->nh_entries[i].nh_parent = nh;
1119 }
1120
1121 if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) {
1122 nhg->mpath = 1;
1123 nh_group_rebalance(nhg);
1124 }
1125
1126 rcu_assign_pointer(nh->nh_grp, nhg);
1127
1128 return nh;
1129
1130out_no_nh:
1131 for (; i >= 0; --i)
1132 nexthop_put(nhg->nh_entries[i].nh);
1133
1134 kfree(nhg);
1135 kfree(nh);
1136
1137 return ERR_PTR(-ENOENT);
1138}
1139
597cfe4f
DA		 1140static int nh_create_ipv4(struct net *net, struct nexthop *nh,
1141 struct nh_info *nhi, struct nh_config *cfg,
1142 struct netlink_ext_ack *extack)
1143{
1144 struct fib_nh *fib_nh = &nhi->fib_nh;
1145 struct fib_config fib_cfg = {
1146 .fc_oif = cfg->nh_ifindex,
1147 .fc_gw4 = cfg->gw.ipv4,
1148 .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0,
1149 .fc_flags = cfg->nh_flags,
b513bd03
DA		 1150 .fc_encap = cfg->nh_encap,
1151 .fc_encap_type = cfg->nh_encap_type,
597cfe4f
DA		 1152 };
1153 u32 tb_id = l3mdev_fib_table(cfg->dev);
1154 int err = -EINVAL;
1155
1156 err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack);
1157 if (err) {
1158 fib_nh_release(net, fib_nh);
1159 goto out;
1160 }
1161
1162 /* sets nh_dev if successful */
1163 err = fib_check_nh(net, fib_nh, tb_id, 0, extack);
1164 if (!err) {
1165 nh->nh_flags = fib_nh->fib_nh_flags;
dcb1ecb5
DA		 1166 fib_info_update_nhc_saddr(net, &fib_nh->nh_common,
1167 fib_nh->fib_nh_scope);
597cfe4f
DA		 1168 } else {
1169 fib_nh_release(net, fib_nh);
1170 }
1171out:
1172 return err;
1173}
1174
53010f99
DA		 1175static int nh_create_ipv6(struct net *net, struct nexthop *nh,
1176 struct nh_info *nhi, struct nh_config *cfg,
1177 struct netlink_ext_ack *extack)
1178{
1179 struct fib6_nh *fib6_nh = &nhi->fib6_nh;
1180 struct fib6_config fib6_cfg = {
1181 .fc_table = l3mdev_fib_table(cfg->dev),
1182 .fc_ifindex = cfg->nh_ifindex,
1183 .fc_gateway = cfg->gw.ipv6,
1184 .fc_flags = cfg->nh_flags,
b513bd03
DA		 1185 .fc_encap = cfg->nh_encap,
1186 .fc_encap_type = cfg->nh_encap_type,
53010f99 1187 };
6f43e525 1188 int err;
53010f99
DA		 1189
1190 if (!ipv6_addr_any(&cfg->gw.ipv6))
1191 fib6_cfg.fc_flags |= RTF_GATEWAY;
1192
1193 /* sets nh_dev if successful */
1194 err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL,
1195 extack);
1196 if (err)
1197 ipv6_stub->fib6_nh_release(fib6_nh);
1198 else
1199 nh->nh_flags = fib6_nh->fib_nh_flags;
1200
1201 return err;
1202}
1203
ab84be7e
DA		 1204static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg,
1205 struct netlink_ext_ack *extack)
1206{
1207 struct nh_info *nhi;
1208 struct nexthop *nh;
1209 int err = 0;
1210
1211 nh = nexthop_alloc();
1212 if (!nh)
1213 return ERR_PTR(-ENOMEM);
1214
1215 nhi = kzalloc(sizeof(*nhi), GFP_KERNEL);
1216 if (!nhi) {
1217 kfree(nh);
1218 return ERR_PTR(-ENOMEM);
1219 }
1220
1221 nh->nh_flags = cfg->nh_flags;
1222 nh->net = net;
1223
1224 nhi->nh_parent = nh;
1225 nhi->family = cfg->nh_family;
1226 nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK;
1227
1228 if (cfg->nh_blackhole) {
1229 nhi->reject_nh = 1;
1230 cfg->nh_ifindex = net->loopback_dev->ifindex;
1231 }
1232
597cfe4f
DA		 1233 switch (cfg->nh_family) {
1234 case AF_INET:
1235 err = nh_create_ipv4(net, nh, nhi, cfg, extack);
1236 break;
53010f99
DA		 1237 case AF_INET6:
1238 err = nh_create_ipv6(net, nh, nhi, cfg, extack);
1239 break;
597cfe4f
DA		 1240 }
1241
ab84be7e
DA		 1242 if (err) {
1243 kfree(nhi);
1244 kfree(nh);
1245 return ERR_PTR(err);
1246 }
1247
597cfe4f
DA		 1248 /* add the entry to the device based hash */
1249 nexthop_devhash_add(net, nhi);
1250
ab84be7e
DA		 1251 rcu_assign_pointer(nh->nh_info, nhi);
1252
1253 return nh;
1254}
1255
1256/* called with rtnl lock held */
1257static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg,
1258 struct netlink_ext_ack *extack)
1259{
1260 struct nexthop *nh;
1261 int err;
1262
1263 if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) {
1264 NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
1265 return ERR_PTR(-EINVAL);
1266 }
1267
1268 if (!cfg->nh_id) {
1269 cfg->nh_id = nh_find_unused_id(net);
1270 if (!cfg->nh_id) {
1271 NL_SET_ERR_MSG(extack, "No unused id");
1272 return ERR_PTR(-EINVAL);
1273 }
1274 }
1275
430a0491
DA		 1276 if (cfg->nh_grp)
1277 nh = nexthop_create_group(net, cfg);
1278 else
1279 nh = nexthop_create(net, cfg, extack);
1280
ab84be7e
DA		 1281 if (IS_ERR(nh))
1282 return nh;
1283
1284 refcount_set(&nh->refcnt, 1);
1285 nh->id = cfg->nh_id;
1286 nh->protocol = cfg->nh_protocol;
1287 nh->net = net;
1288
1289 err = insert_nexthop(net, nh, cfg, extack);
1290 if (err) {
430a0491 1291 __remove_nexthop(net, nh, NULL);
ab84be7e
DA		 1292 nexthop_put(nh);
1293 nh = ERR_PTR(err);
1294 }
1295
1296 return nh;
1297}
1298
1299static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
1300 struct nlmsghdr *nlh, struct nh_config *cfg,
1301 struct netlink_ext_ack *extack)
1302{
1303 struct nhmsg *nhm = nlmsg_data(nlh);
1304 struct nlattr *tb[NHA_MAX + 1];
1305 int err;
1306
1307 err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1308 extack);
1309 if (err < 0)
1310 return err;
1311
1312 err = -EINVAL;
1313 if (nhm->resvd || nhm->nh_scope) {
1314 NL_SET_ERR_MSG(extack, "Invalid values in ancillary header");
1315 goto out;
1316 }
1317 if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) {
1318 NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header");
1319 goto out;
1320 }
1321
1322 switch (nhm->nh_family) {
597cfe4f 1323 case AF_INET:
53010f99 1324 case AF_INET6:
597cfe4f 1325 break;
430a0491
DA		 1326 case AF_UNSPEC:
1327 if (tb[NHA_GROUP])
1328 break;
1329 /* fallthrough */
ab84be7e
DA		 1330 default:
1331 NL_SET_ERR_MSG(extack, "Invalid address family");
1332 goto out;
1333 }
1334
1335 if (tb[NHA_GROUPS] || tb[NHA_MASTER]) {
1336 NL_SET_ERR_MSG(extack, "Invalid attributes in request");
1337 goto out;
1338 }
1339
1340 memset(cfg, 0, sizeof(*cfg));
1341 cfg->nlflags = nlh->nlmsg_flags;
1342 cfg->nlinfo.portid = NETLINK_CB(skb).portid;
1343 cfg->nlinfo.nlh = nlh;
1344 cfg->nlinfo.nl_net = net;
1345
1346 cfg->nh_family = nhm->nh_family;
1347 cfg->nh_protocol = nhm->nh_protocol;
1348 cfg->nh_flags = nhm->nh_flags;
1349
1350 if (tb[NHA_ID])
1351 cfg->nh_id = nla_get_u32(tb[NHA_ID]);
1352
430a0491
DA		 1353 if (tb[NHA_GROUP]) {
1354 if (nhm->nh_family != AF_UNSPEC) {
1355 NL_SET_ERR_MSG(extack, "Invalid family for group");
1356 goto out;
1357 }
1358 cfg->nh_grp = tb[NHA_GROUP];
1359
1360 cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH;
1361 if (tb[NHA_GROUP_TYPE])
1362 cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]);
1363
1364 if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) {
1365 NL_SET_ERR_MSG(extack, "Invalid group type");
1366 goto out;
1367 }
1368 err = nh_check_attr_group(net, tb, extack);
1369
1370 /* no other attributes should be set */
1371 goto out;
1372 }
1373
ab84be7e 1374 if (tb[NHA_BLACKHOLE]) {
b513bd03
DA		 1375 if (tb[NHA_GATEWAY] || tb[NHA_OIF] ||
1376 tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) {
ab84be7e
DA		 1377 NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway or oif");
1378 goto out;
1379 }
1380
1381 cfg->nh_blackhole = 1;
1382 err = 0;
1383 goto out;
1384 }
1385
1386 if (!tb[NHA_OIF]) {
1387 NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole nexthops");
1388 goto out;
1389 }
1390
1391 cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
1392 if (cfg->nh_ifindex)
1393 cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
1394
1395 if (!cfg->dev) {
1396 NL_SET_ERR_MSG(extack, "Invalid device index");
1397 goto out;
1398 } else if (!(cfg->dev->flags & IFF_UP)) {
1399 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
1400 err = -ENETDOWN;
1401 goto out;
1402 } else if (!netif_carrier_ok(cfg->dev)) {
1403 NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");
1404 err = -ENETDOWN;
1405 goto out;
1406 }
1407
597cfe4f
DA		 1408 err = -EINVAL;
1409 if (tb[NHA_GATEWAY]) {
1410 struct nlattr *gwa = tb[NHA_GATEWAY];
1411
1412 switch (cfg->nh_family) {
1413 case AF_INET:
1414 if (nla_len(gwa) != sizeof(u32)) {
1415 NL_SET_ERR_MSG(extack, "Invalid gateway");
1416 goto out;
1417 }
1418 cfg->gw.ipv4 = nla_get_be32(gwa);
1419 break;
53010f99
DA		 1420 case AF_INET6:
1421 if (nla_len(gwa) != sizeof(struct in6_addr)) {
1422 NL_SET_ERR_MSG(extack, "Invalid gateway");
1423 goto out;
1424 }
1425 cfg->gw.ipv6 = nla_get_in6_addr(gwa);
1426 break;
597cfe4f
DA		 1427 default:
1428 NL_SET_ERR_MSG(extack,
1429 "Unknown address family for gateway");
1430 goto out;
1431 }
1432 } else {
1433 /* device only nexthop (no gateway) */
1434 if (cfg->nh_flags & RTNH_F_ONLINK) {
1435 NL_SET_ERR_MSG(extack,
1436 "ONLINK flag can not be set for nexthop without a gateway");
1437 goto out;
1438 }
1439 }
1440
b513bd03
DA		 1441 if (tb[NHA_ENCAP]) {
1442 cfg->nh_encap = tb[NHA_ENCAP];
1443
1444 if (!tb[NHA_ENCAP_TYPE]) {
1445 NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing");
1446 goto out;
1447 }
1448
1449 cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]);
1450 err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack);
1451 if (err < 0)
1452 goto out;
1453
1454 } else if (tb[NHA_ENCAP_TYPE]) {
1455 NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing");
1456 goto out;
1457 }
1458
1459
ab84be7e
DA		 1460 err = 0;
1461out:
1462 return err;
1463}
1464
1465/* rtnl */
1466static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
1467 struct netlink_ext_ack *extack)
1468{
1469 struct net *net = sock_net(skb->sk);
1470 struct nh_config cfg;
1471 struct nexthop *nh;
1472 int err;
1473
1474 err = rtm_to_nh_config(net, skb, nlh, &cfg, extack);
1475 if (!err) {
1476 nh = nexthop_add(net, &cfg, extack);
1477 if (IS_ERR(nh))
1478 err = PTR_ERR(nh);
1479 }
1480
1481 return err;
1482}
1483
1484static int nh_valid_get_del_req(struct nlmsghdr *nlh, u32 *id,
1485 struct netlink_ext_ack *extack)
1486{
1487 struct nhmsg *nhm = nlmsg_data(nlh);
1488 struct nlattr *tb[NHA_MAX + 1];
1489 int err, i;
1490
1491 err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1492 extack);
1493 if (err < 0)
1494 return err;
1495
1496 err = -EINVAL;
1497 for (i = 0; i < __NHA_MAX; ++i) {
1498 if (!tb[i])
1499 continue;
1500
1501 switch (i) {
1502 case NHA_ID:
1503 break;
1504 default:
1505 NL_SET_ERR_MSG_ATTR(extack, tb[i],
1506 "Unexpected attribute in request");
1507 goto out;
1508 }
1509 }
1510 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
1511 NL_SET_ERR_MSG(extack, "Invalid values in header");
1512 goto out;
1513 }
1514
1515 if (!tb[NHA_ID]) {
1516 NL_SET_ERR_MSG(extack, "Nexthop id is missing");
1517 goto out;
1518 }
1519
1520 *id = nla_get_u32(tb[NHA_ID]);
1521 if (!(*id))
1522 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
1523 else
1524 err = 0;
1525out:
1526 return err;
1527}
1528
1529/* rtnl */
1530static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
1531 struct netlink_ext_ack *extack)
1532{
1533 struct net *net = sock_net(skb->sk);
1534 struct nl_info nlinfo = {
1535 .nlh = nlh,
1536 .nl_net = net,
1537 .portid = NETLINK_CB(skb).portid,
1538 };
1539 struct nexthop *nh;
1540 int err;
1541 u32 id;
1542
1543 err = nh_valid_get_del_req(nlh, &id, extack);
1544 if (err)
1545 return err;
1546
1547 nh = nexthop_find_by_id(net, id);
1548 if (!nh)
1549 return -ENOENT;
1550
430a0491 1551 remove_nexthop(net, nh, &nlinfo);
ab84be7e
DA		 1552
1553 return 0;
1554}
1555
1556/* rtnl */
1557static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh,
1558 struct netlink_ext_ack *extack)
1559{
1560 struct net *net = sock_net(in_skb->sk);
1561 struct sk_buff *skb = NULL;
1562 struct nexthop *nh;
1563 int err;
1564 u32 id;
1565
1566 err = nh_valid_get_del_req(nlh, &id, extack);
1567 if (err)
1568 return err;
1569
1570 err = -ENOBUFS;
1571 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1572 if (!skb)
1573 goto out;
1574
1575 err = -ENOENT;
1576 nh = nexthop_find_by_id(net, id);
1577 if (!nh)
1578 goto errout_free;
1579
1580 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid,
1581 nlh->nlmsg_seq, 0);
1582 if (err < 0) {
1583 WARN_ON(err == -EMSGSIZE);
1584 goto errout_free;
1585 }
1586
1587 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
1588out:
1589 return err;
1590errout_free:
1591 kfree_skb(skb);
1592 goto out;
1593}
1594
430a0491
DA		 1595static bool nh_dump_filtered(struct nexthop *nh, int dev_idx, int master_idx,
1596 bool group_filter, u8 family)
ab84be7e
DA		 1597{
1598 const struct net_device *dev;
1599 const struct nh_info *nhi;
1600
430a0491
DA		 1601 if (group_filter && !nh->is_group)
1602 return true;
1603
ab84be7e
DA		 1604 if (!dev_idx && !master_idx && !family)
1605 return false;
1606
430a0491
DA		 1607 if (nh->is_group)
1608 return true;
1609
ab84be7e
DA		 1610 nhi = rtnl_dereference(nh->nh_info);
1611 if (family && nhi->family != family)
1612 return true;
1613
1614 dev = nhi->fib_nhc.nhc_dev;
1615 if (dev_idx && (!dev || dev->ifindex != dev_idx))
1616 return true;
1617
1618 if (master_idx) {
1619 struct net_device *master;
1620
1621 if (!dev)
1622 return true;
1623
1624 master = netdev_master_upper_dev_get((struct net_device *)dev);
1625 if (!master || master->ifindex != master_idx)
1626 return true;
1627 }
1628
1629 return false;
1630}
1631
430a0491
DA		 1632static int nh_valid_dump_req(const struct nlmsghdr *nlh, int *dev_idx,
1633 int *master_idx, bool *group_filter,
ab84be7e
DA		 1634 struct netlink_callback *cb)
1635{
1636 struct netlink_ext_ack *extack = cb->extack;
1637 struct nlattr *tb[NHA_MAX + 1];
1638 struct nhmsg *nhm;
1639 int err, i;
1640 u32 idx;
1641
1642 err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1643 NULL);
1644 if (err < 0)
1645 return err;
1646
1647 for (i = 0; i <= NHA_MAX; ++i) {
1648 if (!tb[i])
1649 continue;
1650
1651 switch (i) {
1652 case NHA_OIF:
1653 idx = nla_get_u32(tb[i]);
1654 if (idx > INT_MAX) {
1655 NL_SET_ERR_MSG(extack, "Invalid device index");
1656 return -EINVAL;
1657 }
1658 *dev_idx = idx;
1659 break;
1660 case NHA_MASTER:
1661 idx = nla_get_u32(tb[i]);
1662 if (idx > INT_MAX) {
1663 NL_SET_ERR_MSG(extack, "Invalid master device index");
1664 return -EINVAL;
1665 }
1666 *master_idx = idx;
1667 break;
430a0491
DA		 1668 case NHA_GROUPS:
1669 *group_filter = true;
1670 break;
ab84be7e
DA		 1671 default:
1672 NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
1673 return -EINVAL;
1674 }
1675 }
1676
1677 nhm = nlmsg_data(nlh);
1678 if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
1679 NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request");
1680 return -EINVAL;
1681 }
1682
1683 return 0;
1684}
1685
1686/* rtnl */
1687static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
1688{
1689 struct nhmsg *nhm = nlmsg_data(cb->nlh);
1690 int dev_filter_idx = 0, master_idx = 0;
1691 struct net *net = sock_net(skb->sk);
1692 struct rb_root *root = &net->nexthop.rb_root;
430a0491 1693 bool group_filter = false;
ab84be7e
DA		 1694 struct rb_node *node;
1695 int idx = 0, s_idx;
1696 int err;
1697
430a0491
DA		 1698 err = nh_valid_dump_req(cb->nlh, &dev_filter_idx, &master_idx,
1699 &group_filter, cb);
ab84be7e
DA		 1700 if (err < 0)
1701 return err;
1702
1703 s_idx = cb->args[0];
1704 for (node = rb_first(root); node; node = rb_next(node)) {
1705 struct nexthop *nh;
1706
1707 if (idx < s_idx)
1708 goto cont;
1709
1710 nh = rb_entry(node, struct nexthop, rb_node);
1711 if (nh_dump_filtered(nh, dev_filter_idx, master_idx,
430a0491 1712 group_filter, nhm->nh_family))
ab84be7e
DA		 1713 goto cont;
1714
1715 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP,
1716 NETLINK_CB(cb->skb).portid,
1717 cb->nlh->nlmsg_seq, NLM_F_MULTI);
1718 if (err < 0) {
1719 if (likely(skb->len))
1720 goto out;
1721
1722 goto out_err;
1723 }
1724cont:
1725 idx++;
1726 }
1727
1728out:
1729 err = skb->len;
1730out_err:
1731 cb->args[0] = idx;
1732 cb->seq = net->nexthop.seq;
1733 nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1734
1735 return err;
1736}
1737
597cfe4f
DA		 1738static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu)
1739{
1740 unsigned int hash = nh_dev_hashfn(dev->ifindex);
1741 struct net *net = dev_net(dev);
1742 struct hlist_head *head = &net->nexthop.devhash[hash];
1743 struct hlist_node *n;
1744 struct nh_info *nhi;
1745
1746 hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
1747 if (nhi->fib_nhc.nhc_dev == dev) {
1748 if (nhi->family == AF_INET)
1749 fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu,
1750 orig_mtu);
1751 }
1752 }
1753}
1754
1755/* rtnl */
1756static int nh_netdev_event(struct notifier_block *this,
1757 unsigned long event, void *ptr)
1758{
1759 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1760 struct netdev_notifier_info_ext *info_ext;
1761
1762 switch (event) {
1763 case NETDEV_DOWN:
1764 case NETDEV_UNREGISTER:
1765 nexthop_flush_dev(dev);
1766 break;
1767 case NETDEV_CHANGE:
1768 if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP)))
1769 nexthop_flush_dev(dev);
1770 break;
1771 case NETDEV_CHANGEMTU:
1772 info_ext = ptr;
1773 nexthop_sync_mtu(dev, info_ext->ext.mtu);
1774 rt_cache_flush(dev_net(dev));
1775 break;
1776 }
1777 return NOTIFY_DONE;
1778}
1779
1780static struct notifier_block nh_netdev_notifier = {
1781 .notifier_call = nh_netdev_event,
1782};
1783
ab84be7e
DA		 1784static void __net_exit nexthop_net_exit(struct net *net)
1785{
1786 rtnl_lock();
1787 flush_all_nexthops(net);
1788 rtnl_unlock();
597cfe4f 1789 kfree(net->nexthop.devhash);
ab84be7e
DA		 1790}
1791
1792static int __net_init nexthop_net_init(struct net *net)
1793{
597cfe4f
DA		 1794 size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE;
1795
ab84be7e 1796 net->nexthop.rb_root = RB_ROOT;
597cfe4f
DA		 1797 net->nexthop.devhash = kzalloc(sz, GFP_KERNEL);
1798 if (!net->nexthop.devhash)
1799 return -ENOMEM;
ab84be7e
DA		 1800
1801 return 0;
1802}
1803
1804static struct pernet_operations nexthop_net_ops = {
1805 .init = nexthop_net_init,
1806 .exit = nexthop_net_exit,
1807};
1808
1809static int __init nexthop_init(void)
1810{
1811 register_pernet_subsys(&nexthop_net_ops);
1812
597cfe4f
DA		 1813 register_netdevice_notifier(&nh_netdev_notifier);
1814
ab84be7e
DA		 1815 rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
1816 rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0);
1817 rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop,
1818 rtm_dump_nexthop, 0);
1819
1820 rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
1821 rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
1822
1823 rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
1824 rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
1825
1826 return 0;
1827}
1828subsys_initcall(nexthop_init);
Linux 6.x block layer and io_uring tree(s)