1
2
3
4
5
6
7
8
9
10
11
12#include <linux/uaccess.h>
13#include <linux/bitops.h>
14#include <linux/types.h>
15#include <linux/kernel.h>
16#include <linux/jiffies.h>
17#include <linux/mm.h>
18#include <linux/string.h>
19#include <linux/socket.h>
20#include <linux/sockios.h>
21#include <linux/errno.h>
22#include <linux/in.h>
23#include <linux/inet.h>
24#include <linux/inetdevice.h>
25#include <linux/netdevice.h>
26#include <linux/if_arp.h>
27#include <linux/proc_fs.h>
28#include <linux/skbuff.h>
29#include <linux/init.h>
30#include <linux/slab.h>
31#include <linux/netlink.h>
32
33#include <net/arp.h>
34#include <net/ip.h>
35#include <net/protocol.h>
36#include <net/route.h>
37#include <net/tcp.h>
38#include <net/sock.h>
39#include <net/ip_fib.h>
40#include <net/ip6_fib.h>
41#include <net/nexthop.h>
42#include <net/netlink.h>
43#include <net/rtnh.h>
44#include <net/lwtunnel.h>
45#include <net/fib_notifier.h>
46#include <net/addrconf.h>
47
48#include "fib_lookup.h"
49
50static DEFINE_SPINLOCK(fib_info_lock);
51static struct hlist_head *fib_info_hash;
52static struct hlist_head *fib_info_laddrhash;
53static unsigned int fib_info_hash_size;
54static unsigned int fib_info_cnt;
55
56#define DEVINDEX_HASHBITS 8
57#define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS)
58static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE];
59
60
61
62
63#ifdef CONFIG_IP_ROUTE_MULTIPATH
64
65#define for_nexthops(fi) { \
66 int nhsel; const struct fib_nh *nh; \
67 for (nhsel = 0, nh = (fi)->fib_nh; \
68 nhsel < fib_info_num_path((fi)); \
69 nh++, nhsel++)
70
71#define change_nexthops(fi) { \
72 int nhsel; struct fib_nh *nexthop_nh; \
73 for (nhsel = 0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
74 nhsel < fib_info_num_path((fi)); \
75 nexthop_nh++, nhsel++)
76
77#else
78
79
80
81#define for_nexthops(fi) { \
82 int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \
83 for (nhsel = 0; nhsel < 1; nhsel++)
84
85#define change_nexthops(fi) { \
86 int nhsel; \
87 struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
88 for (nhsel = 0; nhsel < 1; nhsel++)
89
90#endif
91
92#define endfor_nexthops(fi) }
93
94
95const struct fib_prop fib_props[RTN_MAX + 1] = {
96 [RTN_UNSPEC] = {
97 .error = 0,
98 .scope = RT_SCOPE_NOWHERE,
99 },
100 [RTN_UNICAST] = {
101 .error = 0,
102 .scope = RT_SCOPE_UNIVERSE,
103 },
104 [RTN_LOCAL] = {
105 .error = 0,
106 .scope = RT_SCOPE_HOST,
107 },
108 [RTN_BROADCAST] = {
109 .error = 0,
110 .scope = RT_SCOPE_LINK,
111 },
112 [RTN_ANYCAST] = {
113 .error = 0,
114 .scope = RT_SCOPE_LINK,
115 },
116 [RTN_MULTICAST] = {
117 .error = 0,
118 .scope = RT_SCOPE_UNIVERSE,
119 },
120 [RTN_BLACKHOLE] = {
121 .error = -EINVAL,
122 .scope = RT_SCOPE_UNIVERSE,
123 },
124 [RTN_UNREACHABLE] = {
125 .error = -EHOSTUNREACH,
126 .scope = RT_SCOPE_UNIVERSE,
127 },
128 [RTN_PROHIBIT] = {
129 .error = -EACCES,
130 .scope = RT_SCOPE_UNIVERSE,
131 },
132 [RTN_THROW] = {
133 .error = -EAGAIN,
134 .scope = RT_SCOPE_UNIVERSE,
135 },
136 [RTN_NAT] = {
137 .error = -EINVAL,
138 .scope = RT_SCOPE_NOWHERE,
139 },
140 [RTN_XRESOLVE] = {
141 .error = -EINVAL,
142 .scope = RT_SCOPE_NOWHERE,
143 },
144};
145
146static void rt_fibinfo_free(struct rtable __rcu **rtp)
147{
148 struct rtable *rt = rcu_dereference_protected(*rtp, 1);
149
150 if (!rt)
151 return;
152
153
154
155
156
157
158 dst_dev_put(&rt->dst);
159 dst_release_immediate(&rt->dst);
160}
161
162static void free_nh_exceptions(struct fib_nh_common *nhc)
163{
164 struct fnhe_hash_bucket *hash;
165 int i;
166
167 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1);
168 if (!hash)
169 return;
170 for (i = 0; i < FNHE_HASH_SIZE; i++) {
171 struct fib_nh_exception *fnhe;
172
173 fnhe = rcu_dereference_protected(hash[i].chain, 1);
174 while (fnhe) {
175 struct fib_nh_exception *next;
176
177 next = rcu_dereference_protected(fnhe->fnhe_next, 1);
178
179 rt_fibinfo_free(&fnhe->fnhe_rth_input);
180 rt_fibinfo_free(&fnhe->fnhe_rth_output);
181
182 kfree(fnhe);
183
184 fnhe = next;
185 }
186 }
187 kfree(hash);
188}
189
190static void rt_fibinfo_free_cpus(struct rtable __rcu * __percpu *rtp)
191{
192 int cpu;
193
194 if (!rtp)
195 return;
196
197 for_each_possible_cpu(cpu) {
198 struct rtable *rt;
199
200 rt = rcu_dereference_protected(*per_cpu_ptr(rtp, cpu), 1);
201 if (rt) {
202 dst_dev_put(&rt->dst);
203 dst_release_immediate(&rt->dst);
204 }
205 }
206 free_percpu(rtp);
207}
208
209void fib_nh_common_release(struct fib_nh_common *nhc)
210{
211 if (nhc->nhc_dev)
212 dev_put(nhc->nhc_dev);
213
214 lwtstate_put(nhc->nhc_lwtstate);
215 rt_fibinfo_free_cpus(nhc->nhc_pcpu_rth_output);
216 rt_fibinfo_free(&nhc->nhc_rth_input);
217 free_nh_exceptions(nhc);
218}
219EXPORT_SYMBOL_GPL(fib_nh_common_release);
220
221void fib_nh_release(struct net *net, struct fib_nh *fib_nh)
222{
223#ifdef CONFIG_IP_ROUTE_CLASSID
224 if (fib_nh->nh_tclassid)
225 net->ipv4.fib_num_tclassid_users--;
226#endif
227 fib_nh_common_release(&fib_nh->nh_common);
228}
229
230
231static void free_fib_info_rcu(struct rcu_head *head)
232{
233 struct fib_info *fi = container_of(head, struct fib_info, rcu);
234
235 if (fi->nh) {
236 nexthop_put(fi->nh);
237 } else {
238 change_nexthops(fi) {
239 fib_nh_release(fi->fib_net, nexthop_nh);
240 } endfor_nexthops(fi);
241 }
242
243 ip_fib_metrics_put(fi->fib_metrics);
244
245 kfree(fi);
246}
247
248void free_fib_info(struct fib_info *fi)
249{
250 if (fi->fib_dead == 0) {
251 pr_warn("Freeing alive fib_info %p\n", fi);
252 return;
253 }
254 fib_info_cnt--;
255
256 call_rcu(&fi->rcu, free_fib_info_rcu);
257}
258EXPORT_SYMBOL_GPL(free_fib_info);
259
260void fib_release_info(struct fib_info *fi)
261{
262 spin_lock_bh(&fib_info_lock);
263 if (fi && --fi->fib_treeref == 0) {
264 hlist_del(&fi->fib_hash);
265 if (fi->fib_prefsrc)
266 hlist_del(&fi->fib_lhash);
267 if (fi->nh) {
268 list_del(&fi->nh_list);
269 } else {
270 change_nexthops(fi) {
271 if (!nexthop_nh->fib_nh_dev)
272 continue;
273 hlist_del(&nexthop_nh->nh_hash);
274 } endfor_nexthops(fi)
275 }
276 fi->fib_dead = 1;
277 fib_info_put(fi);
278 }
279 spin_unlock_bh(&fib_info_lock);
280}
281
282static inline int nh_comp(struct fib_info *fi, struct fib_info *ofi)
283{
284 const struct fib_nh *onh;
285
286 if (fi->nh || ofi->nh)
287 return nexthop_cmp(fi->nh, ofi->nh) ? 0 : -1;
288
289 if (ofi->fib_nhs == 0)
290 return 0;
291
292 for_nexthops(fi) {
293 onh = fib_info_nh(ofi, nhsel);
294
295 if (nh->fib_nh_oif != onh->fib_nh_oif ||
296 nh->fib_nh_gw_family != onh->fib_nh_gw_family ||
297 nh->fib_nh_scope != onh->fib_nh_scope ||
298#ifdef CONFIG_IP_ROUTE_MULTIPATH
299 nh->fib_nh_weight != onh->fib_nh_weight ||
300#endif
301#ifdef CONFIG_IP_ROUTE_CLASSID
302 nh->nh_tclassid != onh->nh_tclassid ||
303#endif
304 lwtunnel_cmp_encap(nh->fib_nh_lws, onh->fib_nh_lws) ||
305 ((nh->fib_nh_flags ^ onh->fib_nh_flags) & ~RTNH_COMPARE_MASK))
306 return -1;
307
308 if (nh->fib_nh_gw_family == AF_INET &&
309 nh->fib_nh_gw4 != onh->fib_nh_gw4)
310 return -1;
311
312 if (nh->fib_nh_gw_family == AF_INET6 &&
313 ipv6_addr_cmp(&nh->fib_nh_gw6, &onh->fib_nh_gw6))
314 return -1;
315 } endfor_nexthops(fi);
316 return 0;
317}
318
319static inline unsigned int fib_devindex_hashfn(unsigned int val)
320{
321 unsigned int mask = DEVINDEX_HASHSIZE - 1;
322
323 return (val ^
324 (val >> DEVINDEX_HASHBITS) ^
325 (val >> (DEVINDEX_HASHBITS * 2))) & mask;
326}
327
328static unsigned int fib_info_hashfn_1(int init_val, u8 protocol, u8 scope,
329 u32 prefsrc, u32 priority)
330{
331 unsigned int val = init_val;
332
333 val ^= (protocol << 8) | scope;
334 val ^= prefsrc;
335 val ^= priority;
336
337 return val;
338}
339
340static unsigned int fib_info_hashfn_result(unsigned int val)
341{
342 unsigned int mask = (fib_info_hash_size - 1);
343
344 return (val ^ (val >> 7) ^ (val >> 12)) & mask;
345}
346
347static inline unsigned int fib_info_hashfn(struct fib_info *fi)
348{
349 unsigned int val;
350
351 val = fib_info_hashfn_1(fi->fib_nhs, fi->fib_protocol,
352 fi->fib_scope, (__force u32)fi->fib_prefsrc,
353 fi->fib_priority);
354
355 if (fi->nh) {
356 val ^= fib_devindex_hashfn(fi->nh->id);
357 } else {
358 for_nexthops(fi) {
359 val ^= fib_devindex_hashfn(nh->fib_nh_oif);
360 } endfor_nexthops(fi)
361 }
362
363 return fib_info_hashfn_result(val);
364}
365
366
367static struct fib_info *fib_find_info_nh(struct net *net,
368 const struct fib_config *cfg)
369{
370 struct hlist_head *head;
371 struct fib_info *fi;
372 unsigned int hash;
373
374 hash = fib_info_hashfn_1(fib_devindex_hashfn(cfg->fc_nh_id),
375 cfg->fc_protocol, cfg->fc_scope,
376 (__force u32)cfg->fc_prefsrc,
377 cfg->fc_priority);
378 hash = fib_info_hashfn_result(hash);
379 head = &fib_info_hash[hash];
380
381 hlist_for_each_entry(fi, head, fib_hash) {
382 if (!net_eq(fi->fib_net, net))
383 continue;
384 if (!fi->nh || fi->nh->id != cfg->fc_nh_id)
385 continue;
386 if (cfg->fc_protocol == fi->fib_protocol &&
387 cfg->fc_scope == fi->fib_scope &&
388 cfg->fc_prefsrc == fi->fib_prefsrc &&
389 cfg->fc_priority == fi->fib_priority &&
390 cfg->fc_type == fi->fib_type &&
391 cfg->fc_table == fi->fib_tb_id &&
392 !((cfg->fc_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK))
393 return fi;
394 }
395
396 return NULL;
397}
398
399static struct fib_info *fib_find_info(struct fib_info *nfi)
400{
401 struct hlist_head *head;
402 struct fib_info *fi;
403 unsigned int hash;
404
405 hash = fib_info_hashfn(nfi);
406 head = &fib_info_hash[hash];
407
408 hlist_for_each_entry(fi, head, fib_hash) {
409 if (!net_eq(fi->fib_net, nfi->fib_net))
410 continue;
411 if (fi->fib_nhs != nfi->fib_nhs)
412 continue;
413 if (nfi->fib_protocol == fi->fib_protocol &&
414 nfi->fib_scope == fi->fib_scope &&
415 nfi->fib_prefsrc == fi->fib_prefsrc &&
416 nfi->fib_priority == fi->fib_priority &&
417 nfi->fib_type == fi->fib_type &&
418 memcmp(nfi->fib_metrics, fi->fib_metrics,
419 sizeof(u32) * RTAX_MAX) == 0 &&
420 !((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK) &&
421 nh_comp(fi, nfi) == 0)
422 return fi;
423 }
424
425 return NULL;
426}
427
428
429
430
431int ip_fib_check_default(__be32 gw, struct net_device *dev)
432{
433 struct hlist_head *head;
434 struct fib_nh *nh;
435 unsigned int hash;
436
437 spin_lock(&fib_info_lock);
438
439 hash = fib_devindex_hashfn(dev->ifindex);
440 head = &fib_info_devhash[hash];
441 hlist_for_each_entry(nh, head, nh_hash) {
442 if (nh->fib_nh_dev == dev &&
443 nh->fib_nh_gw4 == gw &&
444 !(nh->fib_nh_flags & RTNH_F_DEAD)) {
445 spin_unlock(&fib_info_lock);
446 return 0;
447 }
448 }
449
450 spin_unlock(&fib_info_lock);
451
452 return -1;
453}
454
455static inline size_t fib_nlmsg_size(struct fib_info *fi)
456{
457 size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
458 + nla_total_size(4)
459 + nla_total_size(4)
460 + nla_total_size(4)
461 + nla_total_size(4)
462 + nla_total_size(TCP_CA_NAME_MAX);
463 unsigned int nhs = fib_info_num_path(fi);
464
465
466 payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
467
468 if (fi->nh)
469 payload += nla_total_size(4);
470
471 if (nhs) {
472 size_t nh_encapsize = 0;
473
474
475
476 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
477 unsigned int i;
478
479
480 nhsize += 2 * nla_total_size(4);
481
482
483 for (i = 0; i < fib_info_num_path(fi); i++) {
484 struct fib_nh_common *nhc = fib_info_nhc(fi, i);
485
486 if (nhc->nhc_lwtstate) {
487
488 nh_encapsize += lwtunnel_get_encap_size(
489 nhc->nhc_lwtstate);
490
491 nh_encapsize += nla_total_size(2);
492 }
493 }
494
495
496 payload += nla_total_size((nhs * nhsize) + nh_encapsize);
497
498 }
499
500 return payload;
501}
502
503void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
504 int dst_len, u32 tb_id, const struct nl_info *info,
505 unsigned int nlm_flags)
506{
507 struct sk_buff *skb;
508 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
509 int err = -ENOBUFS;
510
511 skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL);
512 if (!skb)
513 goto errout;
514
515 err = fib_dump_info(skb, info->portid, seq, event, tb_id,
516 fa->fa_type, key, dst_len,
517 fa->fa_tos, fa->fa_info, nlm_flags);
518 if (err < 0) {
519
520 WARN_ON(err == -EMSGSIZE);
521 kfree_skb(skb);
522 goto errout;
523 }
524 rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_IPV4_ROUTE,
525 info->nlh, GFP_KERNEL);
526 return;
527errout:
528 if (err < 0)
529 rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err);
530}
531
532static int fib_detect_death(struct fib_info *fi, int order,
533 struct fib_info **last_resort, int *last_idx,
534 int dflt)
535{
536 const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
537 struct neighbour *n;
538 int state = NUD_NONE;
539
540 if (likely(nhc->nhc_gw_family == AF_INET))
541 n = neigh_lookup(&arp_tbl, &nhc->nhc_gw.ipv4, nhc->nhc_dev);
542 else if (nhc->nhc_gw_family == AF_INET6)
543 n = neigh_lookup(ipv6_stub->nd_tbl, &nhc->nhc_gw.ipv6,
544 nhc->nhc_dev);
545 else
546 n = NULL;
547
548 if (n) {
549 state = n->nud_state;
550 neigh_release(n);
551 } else {
552 return 0;
553 }
554 if (state == NUD_REACHABLE)
555 return 0;
556 if ((state & NUD_VALID) && order != dflt)
557 return 0;
558 if ((state & NUD_VALID) ||
559 (*last_idx < 0 && order > dflt && state != NUD_INCOMPLETE)) {
560 *last_resort = fi;
561 *last_idx = order;
562 }
563 return 1;
564}
565
566int fib_nh_common_init(struct fib_nh_common *nhc, struct nlattr *encap,
567 u16 encap_type, void *cfg, gfp_t gfp_flags,
568 struct netlink_ext_ack *extack)
569{
570 int err;
571
572 nhc->nhc_pcpu_rth_output = alloc_percpu_gfp(struct rtable __rcu *,
573 gfp_flags);
574 if (!nhc->nhc_pcpu_rth_output)
575 return -ENOMEM;
576
577 if (encap) {
578 struct lwtunnel_state *lwtstate;
579
580 if (encap_type == LWTUNNEL_ENCAP_NONE) {
581 NL_SET_ERR_MSG(extack, "LWT encap type not specified");
582 err = -EINVAL;
583 goto lwt_failure;
584 }
585 err = lwtunnel_build_state(encap_type, encap, nhc->nhc_family,
586 cfg, &lwtstate, extack);
587 if (err)
588 goto lwt_failure;
589
590 nhc->nhc_lwtstate = lwtstate_get(lwtstate);
591 }
592
593 return 0;
594
595lwt_failure:
596 rt_fibinfo_free_cpus(nhc->nhc_pcpu_rth_output);
597 nhc->nhc_pcpu_rth_output = NULL;
598 return err;
599}
600EXPORT_SYMBOL_GPL(fib_nh_common_init);
601
602int fib_nh_init(struct net *net, struct fib_nh *nh,
603 struct fib_config *cfg, int nh_weight,
604 struct netlink_ext_ack *extack)
605{
606 int err;
607
608 nh->fib_nh_family = AF_INET;
609
610 err = fib_nh_common_init(&nh->nh_common, cfg->fc_encap,
611 cfg->fc_encap_type, cfg, GFP_KERNEL, extack);
612 if (err)
613 return err;
614
615 nh->fib_nh_oif = cfg->fc_oif;
616 nh->fib_nh_gw_family = cfg->fc_gw_family;
617 if (cfg->fc_gw_family == AF_INET)
618 nh->fib_nh_gw4 = cfg->fc_gw4;
619 else if (cfg->fc_gw_family == AF_INET6)
620 nh->fib_nh_gw6 = cfg->fc_gw6;
621
622 nh->fib_nh_flags = cfg->fc_flags;
623
624#ifdef CONFIG_IP_ROUTE_CLASSID
625 nh->nh_tclassid = cfg->fc_flow;
626 if (nh->nh_tclassid)
627 net->ipv4.fib_num_tclassid_users++;
628#endif
629#ifdef CONFIG_IP_ROUTE_MULTIPATH
630 nh->fib_nh_weight = nh_weight;
631#endif
632 return 0;
633}
634
635#ifdef CONFIG_IP_ROUTE_MULTIPATH
636
637static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining,
638 struct netlink_ext_ack *extack)
639{
640 int nhs = 0;
641
642 while (rtnh_ok(rtnh, remaining)) {
643 nhs++;
644 rtnh = rtnh_next(rtnh, &remaining);
645 }
646
647
648 if (remaining > 0) {
649 NL_SET_ERR_MSG(extack,
650 "Invalid nexthop configuration - extra data after nexthops");
651 nhs = 0;
652 }
653
654 return nhs;
655}
656
657
658static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
659 int remaining, struct fib_config *cfg,
660 struct netlink_ext_ack *extack)
661{
662 struct net *net = fi->fib_net;
663 struct fib_config fib_cfg;
664 struct fib_nh *nh;
665 int ret;
666
667 change_nexthops(fi) {
668 int attrlen;
669
670 memset(&fib_cfg, 0, sizeof(fib_cfg));
671
672 if (!rtnh_ok(rtnh, remaining)) {
673 NL_SET_ERR_MSG(extack,
674 "Invalid nexthop configuration - extra data after nexthop");
675 return -EINVAL;
676 }
677
678 if (rtnh->rtnh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) {
679 NL_SET_ERR_MSG(extack,
680 "Invalid flags for nexthop - can not contain DEAD or LINKDOWN");
681 return -EINVAL;
682 }
683
684 fib_cfg.fc_flags = (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags;
685 fib_cfg.fc_oif = rtnh->rtnh_ifindex;
686
687 attrlen = rtnh_attrlen(rtnh);
688 if (attrlen > 0) {
689 struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh);
690
691 nla = nla_find(attrs, attrlen, RTA_GATEWAY);
692 nlav = nla_find(attrs, attrlen, RTA_VIA);
693 if (nla && nlav) {
694 NL_SET_ERR_MSG(extack,
695 "Nexthop configuration can not contain both GATEWAY and VIA");
696 return -EINVAL;
697 }
698 if (nla) {
699 fib_cfg.fc_gw4 = nla_get_in_addr(nla);
700 if (fib_cfg.fc_gw4)
701 fib_cfg.fc_gw_family = AF_INET;
702 } else if (nlav) {
703 ret = fib_gw_from_via(&fib_cfg, nlav, extack);
704 if (ret)
705 goto errout;
706 }
707
708 nla = nla_find(attrs, attrlen, RTA_FLOW);
709 if (nla)
710 fib_cfg.fc_flow = nla_get_u32(nla);
711
712 fib_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
713 nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
714 if (nla)
715 fib_cfg.fc_encap_type = nla_get_u16(nla);
716 }
717
718 ret = fib_nh_init(net, nexthop_nh, &fib_cfg,
719 rtnh->rtnh_hops + 1, extack);
720 if (ret)
721 goto errout;
722
723 rtnh = rtnh_next(rtnh, &remaining);
724 } endfor_nexthops(fi);
725
726 ret = -EINVAL;
727 nh = fib_info_nh(fi, 0);
728 if (cfg->fc_oif && nh->fib_nh_oif != cfg->fc_oif) {
729 NL_SET_ERR_MSG(extack,
730 "Nexthop device index does not match RTA_OIF");
731 goto errout;
732 }
733 if (cfg->fc_gw_family) {
734 if (cfg->fc_gw_family != nh->fib_nh_gw_family ||
735 (cfg->fc_gw_family == AF_INET &&
736 nh->fib_nh_gw4 != cfg->fc_gw4) ||
737 (cfg->fc_gw_family == AF_INET6 &&
738 ipv6_addr_cmp(&nh->fib_nh_gw6, &cfg->fc_gw6))) {
739 NL_SET_ERR_MSG(extack,
740 "Nexthop gateway does not match RTA_GATEWAY or RTA_VIA");
741 goto errout;
742 }
743 }
744#ifdef CONFIG_IP_ROUTE_CLASSID
745 if (cfg->fc_flow && nh->nh_tclassid != cfg->fc_flow) {
746 NL_SET_ERR_MSG(extack,
747 "Nexthop class id does not match RTA_FLOW");
748 goto errout;
749 }
750#endif
751 ret = 0;
752errout:
753 return ret;
754}
755
756
757static void fib_rebalance(struct fib_info *fi)
758{
759 int total;
760 int w;
761
762 if (fib_info_num_path(fi) < 2)
763 return;
764
765 total = 0;
766 for_nexthops(fi) {
767 if (nh->fib_nh_flags & RTNH_F_DEAD)
768 continue;
769
770 if (ip_ignore_linkdown(nh->fib_nh_dev) &&
771 nh->fib_nh_flags & RTNH_F_LINKDOWN)
772 continue;
773
774 total += nh->fib_nh_weight;
775 } endfor_nexthops(fi);
776
777 w = 0;
778 change_nexthops(fi) {
779 int upper_bound;
780
781 if (nexthop_nh->fib_nh_flags & RTNH_F_DEAD) {
782 upper_bound = -1;
783 } else if (ip_ignore_linkdown(nexthop_nh->fib_nh_dev) &&
784 nexthop_nh->fib_nh_flags & RTNH_F_LINKDOWN) {
785 upper_bound = -1;
786 } else {
787 w += nexthop_nh->fib_nh_weight;
788 upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31,
789 total) - 1;
790 }
791
792 atomic_set(&nexthop_nh->fib_nh_upper_bound, upper_bound);
793 } endfor_nexthops(fi);
794}
795#else
796
797static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
798 int remaining, struct fib_config *cfg,
799 struct netlink_ext_ack *extack)
800{
801 NL_SET_ERR_MSG(extack, "Multipath support not enabled in kernel");
802
803 return -EINVAL;
804}
805
806#define fib_rebalance(fi) do { } while (0)
807
808#endif
809
810static int fib_encap_match(u16 encap_type,
811 struct nlattr *encap,
812 const struct fib_nh *nh,
813 const struct fib_config *cfg,
814 struct netlink_ext_ack *extack)
815{
816 struct lwtunnel_state *lwtstate;
817 int ret, result = 0;
818
819 if (encap_type == LWTUNNEL_ENCAP_NONE)
820 return 0;
821
822 ret = lwtunnel_build_state(encap_type, encap, AF_INET,
823 cfg, &lwtstate, extack);
824 if (!ret) {
825 result = lwtunnel_cmp_encap(lwtstate, nh->fib_nh_lws);
826 lwtstate_free(lwtstate);
827 }
828
829 return result;
830}
831
832int fib_nh_match(struct fib_config *cfg, struct fib_info *fi,
833 struct netlink_ext_ack *extack)
834{
835#ifdef CONFIG_IP_ROUTE_MULTIPATH
836 struct rtnexthop *rtnh;
837 int remaining;
838#endif
839
840 if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority)
841 return 1;
842
843 if (cfg->fc_nh_id) {
844 if (fi->nh && cfg->fc_nh_id == fi->nh->id)
845 return 0;
846 return 1;
847 }
848
849 if (cfg->fc_oif || cfg->fc_gw_family) {
850 struct fib_nh *nh = fib_info_nh(fi, 0);
851
852 if (cfg->fc_encap) {
853 if (fib_encap_match(cfg->fc_encap_type, cfg->fc_encap,
854 nh, cfg, extack))
855 return 1;
856 }
857#ifdef CONFIG_IP_ROUTE_CLASSID
858 if (cfg->fc_flow &&
859 cfg->fc_flow != nh->nh_tclassid)
860 return 1;
861#endif
862 if ((cfg->fc_oif && cfg->fc_oif != nh->fib_nh_oif) ||
863 (cfg->fc_gw_family &&
864 cfg->fc_gw_family != nh->fib_nh_gw_family))
865 return 1;
866
867 if (cfg->fc_gw_family == AF_INET &&
868 cfg->fc_gw4 != nh->fib_nh_gw4)
869 return 1;
870
871 if (cfg->fc_gw_family == AF_INET6 &&
872 ipv6_addr_cmp(&cfg->fc_gw6, &nh->fib_nh_gw6))
873 return 1;
874
875 return 0;
876 }
877
878#ifdef CONFIG_IP_ROUTE_MULTIPATH
879 if (!cfg->fc_mp)
880 return 0;
881
882 rtnh = cfg->fc_mp;
883 remaining = cfg->fc_mp_len;
884
885 for_nexthops(fi) {
886 int attrlen;
887
888 if (!rtnh_ok(rtnh, remaining))
889 return -EINVAL;
890
891 if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->fib_nh_oif)
892 return 1;
893
894 attrlen = rtnh_attrlen(rtnh);
895 if (attrlen > 0) {
896 struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh);
897
898 nla = nla_find(attrs, attrlen, RTA_GATEWAY);
899 nlav = nla_find(attrs, attrlen, RTA_VIA);
900 if (nla && nlav) {
901 NL_SET_ERR_MSG(extack,
902 "Nexthop configuration can not contain both GATEWAY and VIA");
903 return -EINVAL;
904 }
905
906 if (nla) {
907 if (nh->fib_nh_gw_family != AF_INET ||
908 nla_get_in_addr(nla) != nh->fib_nh_gw4)
909 return 1;
910 } else if (nlav) {
911 struct fib_config cfg2;
912 int err;
913
914 err = fib_gw_from_via(&cfg2, nlav, extack);
915 if (err)
916 return err;
917
918 switch (nh->fib_nh_gw_family) {
919 case AF_INET:
920 if (cfg2.fc_gw_family != AF_INET ||
921 cfg2.fc_gw4 != nh->fib_nh_gw4)
922 return 1;
923 break;
924 case AF_INET6:
925 if (cfg2.fc_gw_family != AF_INET6 ||
926 ipv6_addr_cmp(&cfg2.fc_gw6,
927 &nh->fib_nh_gw6))
928 return 1;
929 break;
930 }
931 }
932
933#ifdef CONFIG_IP_ROUTE_CLASSID
934 nla = nla_find(attrs, attrlen, RTA_FLOW);
935 if (nla && nla_get_u32(nla) != nh->nh_tclassid)
936 return 1;
937#endif
938 }
939
940 rtnh = rtnh_next(rtnh, &remaining);
941 } endfor_nexthops(fi);
942#endif
943 return 0;
944}
945
946bool fib_metrics_match(struct fib_config *cfg, struct fib_info *fi)
947{
948 struct nlattr *nla;
949 int remaining;
950
951 if (!cfg->fc_mx)
952 return true;
953
954 nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
955 int type = nla_type(nla);
956 u32 fi_val, val;
957
958 if (!type)
959 continue;
960 if (type > RTAX_MAX)
961 return false;
962
963 if (type == RTAX_CC_ALGO) {
964 char tmp[TCP_CA_NAME_MAX];
965 bool ecn_ca = false;
966
967 nla_strlcpy(tmp, nla, sizeof(tmp));
968 val = tcp_ca_get_key_by_name(fi->fib_net, tmp, &ecn_ca);
969 } else {
970 if (nla_len(nla) != sizeof(u32))
971 return false;
972 val = nla_get_u32(nla);
973 }
974
975 fi_val = fi->fib_metrics->metrics[type - 1];
976 if (type == RTAX_FEATURES)
977 fi_val &= ~DST_FEATURE_ECN_CA;
978
979 if (fi_val != val)
980 return false;
981 }
982
983 return true;
984}
985
986static int fib_check_nh_v6_gw(struct net *net, struct fib_nh *nh,
987 u32 table, struct netlink_ext_ack *extack)
988{
989 struct fib6_config cfg = {
990 .fc_table = table,
991 .fc_flags = nh->fib_nh_flags | RTF_GATEWAY,
992 .fc_ifindex = nh->fib_nh_oif,
993 .fc_gateway = nh->fib_nh_gw6,
994 };
995 struct fib6_nh fib6_nh = {};
996 int err;
997
998 err = ipv6_stub->fib6_nh_init(net, &fib6_nh, &cfg, GFP_KERNEL, extack);
999 if (!err) {
1000 nh->fib_nh_dev = fib6_nh.fib_nh_dev;
1001 dev_hold(nh->fib_nh_dev);
1002 nh->fib_nh_oif = nh->fib_nh_dev->ifindex;
1003 nh->fib_nh_scope = RT_SCOPE_LINK;
1004
1005 ipv6_stub->fib6_nh_release(&fib6_nh);
1006 }
1007
1008 return err;
1009}
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table,
1055 u8 scope, struct netlink_ext_ack *extack)
1056{
1057 struct net_device *dev;
1058 struct fib_result res;
1059 int err = 0;
1060
1061 if (nh->fib_nh_flags & RTNH_F_ONLINK) {
1062 unsigned int addr_type;
1063
1064 if (scope >= RT_SCOPE_LINK) {
1065 NL_SET_ERR_MSG(extack, "Nexthop has invalid scope");
1066 return -EINVAL;
1067 }
1068 dev = __dev_get_by_index(net, nh->fib_nh_oif);
1069 if (!dev) {
1070 NL_SET_ERR_MSG(extack, "Nexthop device required for onlink");
1071 return -ENODEV;
1072 }
1073 if (!(dev->flags & IFF_UP)) {
1074 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
1075 return -ENETDOWN;
1076 }
1077 addr_type = inet_addr_type_dev_table(net, dev, nh->fib_nh_gw4);
1078 if (addr_type != RTN_UNICAST) {
1079 NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway");
1080 return -EINVAL;
1081 }
1082 if (!netif_carrier_ok(dev))
1083 nh->fib_nh_flags |= RTNH_F_LINKDOWN;
1084 nh->fib_nh_dev = dev;
1085 dev_hold(dev);
1086 nh->fib_nh_scope = RT_SCOPE_LINK;
1087 return 0;
1088 }
1089 rcu_read_lock();
1090 {
1091 struct fib_table *tbl = NULL;
1092 struct flowi4 fl4 = {
1093 .daddr = nh->fib_nh_gw4,
1094 .flowi4_scope = scope + 1,
1095 .flowi4_oif = nh->fib_nh_oif,
1096 .flowi4_iif = LOOPBACK_IFINDEX,
1097 };
1098
1099
1100 if (fl4.flowi4_scope < RT_SCOPE_LINK)
1101 fl4.flowi4_scope = RT_SCOPE_LINK;
1102
1103 if (table)
1104 tbl = fib_get_table(net, table);
1105
1106 if (tbl)
1107 err = fib_table_lookup(tbl, &fl4, &res,
1108 FIB_LOOKUP_IGNORE_LINKSTATE |
1109 FIB_LOOKUP_NOREF);
1110
1111
1112
1113
1114
1115 if (!tbl || err) {
1116 err = fib_lookup(net, &fl4, &res,
1117 FIB_LOOKUP_IGNORE_LINKSTATE);
1118 }
1119
1120 if (err) {
1121 NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway");
1122 goto out;
1123 }
1124 }
1125
1126 err = -EINVAL;
1127 if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) {
1128 NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway");
1129 goto out;
1130 }
1131 nh->fib_nh_scope = res.scope;
1132 nh->fib_nh_oif = FIB_RES_OIF(res);
1133 nh->fib_nh_dev = dev = FIB_RES_DEV(res);
1134 if (!dev) {
1135 NL_SET_ERR_MSG(extack,
1136 "No egress device for nexthop gateway");
1137 goto out;
1138 }
1139 dev_hold(dev);
1140 if (!netif_carrier_ok(dev))
1141 nh->fib_nh_flags |= RTNH_F_LINKDOWN;
1142 err = (dev->flags & IFF_UP) ? 0 : -ENETDOWN;
1143out:
1144 rcu_read_unlock();
1145 return err;
1146}
1147
1148static int fib_check_nh_nongw(struct net *net, struct fib_nh *nh,
1149 struct netlink_ext_ack *extack)
1150{
1151 struct in_device *in_dev;
1152 int err;
1153
1154 if (nh->fib_nh_flags & (RTNH_F_PERVASIVE | RTNH_F_ONLINK)) {
1155 NL_SET_ERR_MSG(extack,
1156 "Invalid flags for nexthop - PERVASIVE and ONLINK can not be set");
1157 return -EINVAL;
1158 }
1159
1160 rcu_read_lock();
1161
1162 err = -ENODEV;
1163 in_dev = inetdev_by_index(net, nh->fib_nh_oif);
1164 if (!in_dev)
1165 goto out;
1166 err = -ENETDOWN;
1167 if (!(in_dev->dev->flags & IFF_UP)) {
1168 NL_SET_ERR_MSG(extack, "Device for nexthop is not up");
1169 goto out;
1170 }
1171
1172 nh->fib_nh_dev = in_dev->dev;
1173 dev_hold(nh->fib_nh_dev);
1174 nh->fib_nh_scope = RT_SCOPE_HOST;
1175 if (!netif_carrier_ok(nh->fib_nh_dev))
1176 nh->fib_nh_flags |= RTNH_F_LINKDOWN;
1177 err = 0;
1178out:
1179 rcu_read_unlock();
1180 return err;
1181}
1182
1183int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope,
1184 struct netlink_ext_ack *extack)
1185{
1186 int err;
1187
1188 if (nh->fib_nh_gw_family == AF_INET)
1189 err = fib_check_nh_v4_gw(net, nh, table, scope, extack);
1190 else if (nh->fib_nh_gw_family == AF_INET6)
1191 err = fib_check_nh_v6_gw(net, nh, table, extack);
1192 else
1193 err = fib_check_nh_nongw(net, nh, extack);
1194
1195 return err;
1196}
1197
1198static inline unsigned int fib_laddr_hashfn(__be32 val)
1199{
1200 unsigned int mask = (fib_info_hash_size - 1);
1201
1202 return ((__force u32)val ^
1203 ((__force u32)val >> 7) ^
1204 ((__force u32)val >> 14)) & mask;
1205}
1206
1207static struct hlist_head *fib_info_hash_alloc(int bytes)
1208{
1209 if (bytes <= PAGE_SIZE)
1210 return kzalloc(bytes, GFP_KERNEL);
1211 else
1212 return (struct hlist_head *)
1213 __get_free_pages(GFP_KERNEL | __GFP_ZERO,
1214 get_order(bytes));
1215}
1216
1217static void fib_info_hash_free(struct hlist_head *hash, int bytes)
1218{
1219 if (!hash)
1220 return;
1221
1222 if (bytes <= PAGE_SIZE)
1223 kfree(hash);
1224 else
1225 free_pages((unsigned long) hash, get_order(bytes));
1226}
1227
1228static void fib_info_hash_move(struct hlist_head *new_info_hash,
1229 struct hlist_head *new_laddrhash,
1230 unsigned int new_size)
1231{
1232 struct hlist_head *old_info_hash, *old_laddrhash;
1233 unsigned int old_size = fib_info_hash_size;
1234 unsigned int i, bytes;
1235
1236 spin_lock_bh(&fib_info_lock);
1237 old_info_hash = fib_info_hash;
1238 old_laddrhash = fib_info_laddrhash;
1239 fib_info_hash_size = new_size;
1240
1241 for (i = 0; i < old_size; i++) {
1242 struct hlist_head *head = &fib_info_hash[i];
1243 struct hlist_node *n;
1244 struct fib_info *fi;
1245
1246 hlist_for_each_entry_safe(fi, n, head, fib_hash) {
1247 struct hlist_head *dest;
1248 unsigned int new_hash;
1249
1250 new_hash = fib_info_hashfn(fi);
1251 dest = &new_info_hash[new_hash];
1252 hlist_add_head(&fi->fib_hash, dest);
1253 }
1254 }
1255 fib_info_hash = new_info_hash;
1256
1257 for (i = 0; i < old_size; i++) {
1258 struct hlist_head *lhead = &fib_info_laddrhash[i];
1259 struct hlist_node *n;
1260 struct fib_info *fi;
1261
1262 hlist_for_each_entry_safe(fi, n, lhead, fib_lhash) {
1263 struct hlist_head *ldest;
1264 unsigned int new_hash;
1265
1266 new_hash = fib_laddr_hashfn(fi->fib_prefsrc);
1267 ldest = &new_laddrhash[new_hash];
1268 hlist_add_head(&fi->fib_lhash, ldest);
1269 }
1270 }
1271 fib_info_laddrhash = new_laddrhash;
1272
1273 spin_unlock_bh(&fib_info_lock);
1274
1275 bytes = old_size * sizeof(struct hlist_head *);
1276 fib_info_hash_free(old_info_hash, bytes);
1277 fib_info_hash_free(old_laddrhash, bytes);
1278}
1279
1280__be32 fib_info_update_nhc_saddr(struct net *net, struct fib_nh_common *nhc,
1281 unsigned char scope)
1282{
1283 struct fib_nh *nh;
1284
1285 if (nhc->nhc_family != AF_INET)
1286 return inet_select_addr(nhc->nhc_dev, 0, scope);
1287
1288 nh = container_of(nhc, struct fib_nh, nh_common);
1289 nh->nh_saddr = inet_select_addr(nh->fib_nh_dev, nh->fib_nh_gw4, scope);
1290 nh->nh_saddr_genid = atomic_read(&net->ipv4.dev_addr_genid);
1291
1292 return nh->nh_saddr;
1293}
1294
1295__be32 fib_result_prefsrc(struct net *net, struct fib_result *res)
1296{
1297 struct fib_nh_common *nhc = res->nhc;
1298
1299 if (res->fi->fib_prefsrc)
1300 return res->fi->fib_prefsrc;
1301
1302 if (nhc->nhc_family == AF_INET) {
1303 struct fib_nh *nh;
1304
1305 nh = container_of(nhc, struct fib_nh, nh_common);
1306 if (nh->nh_saddr_genid == atomic_read(&net->ipv4.dev_addr_genid))
1307 return nh->nh_saddr;
1308 }
1309
1310 return fib_info_update_nhc_saddr(net, nhc, res->fi->fib_scope);
1311}
1312
1313static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc)
1314{
1315 if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst ||
1316 fib_prefsrc != cfg->fc_dst) {
1317 u32 tb_id = cfg->fc_table;
1318 int rc;
1319
1320 if (tb_id == RT_TABLE_MAIN)
1321 tb_id = RT_TABLE_LOCAL;
1322
1323 rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net,
1324 fib_prefsrc, tb_id);
1325
1326 if (rc != RTN_LOCAL && tb_id != RT_TABLE_LOCAL) {
1327 rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net,
1328 fib_prefsrc, RT_TABLE_LOCAL);
1329 }
1330
1331 if (rc != RTN_LOCAL)
1332 return false;
1333 }
1334 return true;
1335}
1336
1337struct fib_info *fib_create_info(struct fib_config *cfg,
1338 struct netlink_ext_ack *extack)
1339{
1340 int err;
1341 struct fib_info *fi = NULL;
1342 struct nexthop *nh = NULL;
1343 struct fib_info *ofi;
1344 int nhs = 1;
1345 struct net *net = cfg->fc_nlinfo.nl_net;
1346
1347 if (cfg->fc_type > RTN_MAX)
1348 goto err_inval;
1349
1350
1351 if (fib_props[cfg->fc_type].scope > cfg->fc_scope) {
1352 NL_SET_ERR_MSG(extack, "Invalid scope");
1353 goto err_inval;
1354 }
1355
1356 if (cfg->fc_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) {
1357 NL_SET_ERR_MSG(extack,
1358 "Invalid rtm_flags - can not contain DEAD or LINKDOWN");
1359 goto err_inval;
1360 }
1361
1362 if (cfg->fc_nh_id) {
1363 if (!cfg->fc_mx) {
1364 fi = fib_find_info_nh(net, cfg);
1365 if (fi) {
1366 fi->fib_treeref++;
1367 return fi;
1368 }
1369 }
1370
1371 nh = nexthop_find_by_id(net, cfg->fc_nh_id);
1372 if (!nh) {
1373 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
1374 goto err_inval;
1375 }
1376 nhs = 0;
1377 }
1378
1379#ifdef CONFIG_IP_ROUTE_MULTIPATH
1380 if (cfg->fc_mp) {
1381 nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len, extack);
1382 if (nhs == 0)
1383 goto err_inval;
1384 }
1385#endif
1386
1387 err = -ENOBUFS;
1388 if (fib_info_cnt >= fib_info_hash_size) {
1389 unsigned int new_size = fib_info_hash_size << 1;
1390 struct hlist_head *new_info_hash;
1391 struct hlist_head *new_laddrhash;
1392 unsigned int bytes;
1393
1394 if (!new_size)
1395 new_size = 16;
1396 bytes = new_size * sizeof(struct hlist_head *);
1397 new_info_hash = fib_info_hash_alloc(bytes);
1398 new_laddrhash = fib_info_hash_alloc(bytes);
1399 if (!new_info_hash || !new_laddrhash) {
1400 fib_info_hash_free(new_info_hash, bytes);
1401 fib_info_hash_free(new_laddrhash, bytes);
1402 } else
1403 fib_info_hash_move(new_info_hash, new_laddrhash, new_size);
1404
1405 if (!fib_info_hash_size)
1406 goto failure;
1407 }
1408
1409 fi = kzalloc(struct_size(fi, fib_nh, nhs), GFP_KERNEL);
1410 if (!fi)
1411 goto failure;
1412 fi->fib_metrics = ip_fib_metrics_init(fi->fib_net, cfg->fc_mx,
1413 cfg->fc_mx_len, extack);
1414 if (IS_ERR(fi->fib_metrics)) {
1415 err = PTR_ERR(fi->fib_metrics);
1416 kfree(fi);
1417 return ERR_PTR(err);
1418 }
1419
1420 fib_info_cnt++;
1421 fi->fib_net = net;
1422 fi->fib_protocol = cfg->fc_protocol;
1423 fi->fib_scope = cfg->fc_scope;
1424 fi->fib_flags = cfg->fc_flags;
1425 fi->fib_priority = cfg->fc_priority;
1426 fi->fib_prefsrc = cfg->fc_prefsrc;
1427 fi->fib_type = cfg->fc_type;
1428 fi->fib_tb_id = cfg->fc_table;
1429
1430 fi->fib_nhs = nhs;
1431 if (nh) {
1432 if (!nexthop_get(nh)) {
1433 NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
1434 err = -EINVAL;
1435 } else {
1436 err = 0;
1437 fi->nh = nh;
1438 }
1439 } else {
1440 change_nexthops(fi) {
1441 nexthop_nh->nh_parent = fi;
1442 } endfor_nexthops(fi)
1443
1444 if (cfg->fc_mp)
1445 err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg,
1446 extack);
1447 else
1448 err = fib_nh_init(net, fi->fib_nh, cfg, 1, extack);
1449 }
1450
1451 if (err != 0)
1452 goto failure;
1453
1454 if (fib_props[cfg->fc_type].error) {
1455 if (cfg->fc_gw_family || cfg->fc_oif || cfg->fc_mp) {
1456 NL_SET_ERR_MSG(extack,
1457 "Gateway, device and multipath can not be specified for this route type");
1458 goto err_inval;
1459 }
1460 goto link_it;
1461 } else {
1462 switch (cfg->fc_type) {
1463 case RTN_UNICAST:
1464 case RTN_LOCAL:
1465 case RTN_BROADCAST:
1466 case RTN_ANYCAST:
1467 case RTN_MULTICAST:
1468 break;
1469 default:
1470 NL_SET_ERR_MSG(extack, "Invalid route type");
1471 goto err_inval;
1472 }
1473 }
1474
1475 if (cfg->fc_scope > RT_SCOPE_HOST) {
1476 NL_SET_ERR_MSG(extack, "Invalid scope");
1477 goto err_inval;
1478 }
1479
1480 if (fi->nh) {
1481 err = fib_check_nexthop(fi->nh, cfg->fc_scope, extack);
1482 if (err)
1483 goto failure;
1484 } else if (cfg->fc_scope == RT_SCOPE_HOST) {
1485 struct fib_nh *nh = fi->fib_nh;
1486
1487
1488 if (nhs != 1) {
1489 NL_SET_ERR_MSG(extack,
1490 "Route with host scope can not have multiple nexthops");
1491 goto err_inval;
1492 }
1493 if (nh->fib_nh_gw_family) {
1494 NL_SET_ERR_MSG(extack,
1495 "Route with host scope can not have a gateway");
1496 goto err_inval;
1497 }
1498 nh->fib_nh_scope = RT_SCOPE_NOWHERE;
1499 nh->fib_nh_dev = dev_get_by_index(net, nh->fib_nh_oif);
1500 err = -ENODEV;
1501 if (!nh->fib_nh_dev)
1502 goto failure;
1503 } else {
1504 int linkdown = 0;
1505
1506 change_nexthops(fi) {
1507 err = fib_check_nh(cfg->fc_nlinfo.nl_net, nexthop_nh,
1508 cfg->fc_table, cfg->fc_scope,
1509 extack);
1510 if (err != 0)
1511 goto failure;
1512 if (nexthop_nh->fib_nh_flags & RTNH_F_LINKDOWN)
1513 linkdown++;
1514 } endfor_nexthops(fi)
1515 if (linkdown == fi->fib_nhs)
1516 fi->fib_flags |= RTNH_F_LINKDOWN;
1517 }
1518
1519 if (fi->fib_prefsrc && !fib_valid_prefsrc(cfg, fi->fib_prefsrc)) {
1520 NL_SET_ERR_MSG(extack, "Invalid prefsrc address");
1521 goto err_inval;
1522 }
1523
1524 if (!fi->nh) {
1525 change_nexthops(fi) {
1526 fib_info_update_nhc_saddr(net, &nexthop_nh->nh_common,
1527 fi->fib_scope);
1528 if (nexthop_nh->fib_nh_gw_family == AF_INET6)
1529 fi->fib_nh_is_v6 = true;
1530 } endfor_nexthops(fi)
1531
1532 fib_rebalance(fi);
1533 }
1534
1535link_it:
1536 ofi = fib_find_info(fi);
1537 if (ofi) {
1538 fi->fib_dead = 1;
1539 free_fib_info(fi);
1540 ofi->fib_treeref++;
1541 return ofi;
1542 }
1543
1544 fi->fib_treeref++;
1545 refcount_set(&fi->fib_clntref, 1);
1546 spin_lock_bh(&fib_info_lock);
1547 hlist_add_head(&fi->fib_hash,
1548 &fib_info_hash[fib_info_hashfn(fi)]);
1549 if (fi->fib_prefsrc) {
1550 struct hlist_head *head;
1551
1552 head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)];
1553 hlist_add_head(&fi->fib_lhash, head);
1554 }
1555 if (fi->nh) {
1556 list_add(&fi->nh_list, &nh->fi_list);
1557 } else {
1558 change_nexthops(fi) {
1559 struct hlist_head *head;
1560 unsigned int hash;
1561
1562 if (!nexthop_nh->fib_nh_dev)
1563 continue;
1564 hash = fib_devindex_hashfn(nexthop_nh->fib_nh_dev->ifindex);
1565 head = &fib_info_devhash[hash];
1566 hlist_add_head(&nexthop_nh->nh_hash, head);
1567 } endfor_nexthops(fi)
1568 }
1569 spin_unlock_bh(&fib_info_lock);
1570 return fi;
1571
1572err_inval:
1573 err = -EINVAL;
1574
1575failure:
1576 if (fi) {
1577 fi->fib_dead = 1;
1578 free_fib_info(fi);
1579 }
1580
1581 return ERR_PTR(err);
1582}
1583
1584int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc,
1585 u8 rt_family, unsigned char *flags, bool skip_oif)
1586{
1587 if (nhc->nhc_flags & RTNH_F_DEAD)
1588 *flags |= RTNH_F_DEAD;
1589
1590 if (nhc->nhc_flags & RTNH_F_LINKDOWN) {
1591 *flags |= RTNH_F_LINKDOWN;
1592
1593 rcu_read_lock();
1594 switch (nhc->nhc_family) {
1595 case AF_INET:
1596 if (ip_ignore_linkdown(nhc->nhc_dev))
1597 *flags |= RTNH_F_DEAD;
1598 break;
1599 case AF_INET6:
1600 if (ip6_ignore_linkdown(nhc->nhc_dev))
1601 *flags |= RTNH_F_DEAD;
1602 break;
1603 }
1604 rcu_read_unlock();
1605 }
1606
1607 switch (nhc->nhc_gw_family) {
1608 case AF_INET:
1609 if (nla_put_in_addr(skb, RTA_GATEWAY, nhc->nhc_gw.ipv4))
1610 goto nla_put_failure;
1611 break;
1612 case AF_INET6:
1613
1614
1615
1616 if (rt_family != nhc->nhc_gw_family) {
1617 int alen = sizeof(struct in6_addr);
1618 struct nlattr *nla;
1619 struct rtvia *via;
1620
1621 nla = nla_reserve(skb, RTA_VIA, alen + 2);
1622 if (!nla)
1623 goto nla_put_failure;
1624
1625 via = nla_data(nla);
1626 via->rtvia_family = AF_INET6;
1627 memcpy(via->rtvia_addr, &nhc->nhc_gw.ipv6, alen);
1628 } else if (nla_put_in6_addr(skb, RTA_GATEWAY,
1629 &nhc->nhc_gw.ipv6) < 0) {
1630 goto nla_put_failure;
1631 }
1632 break;
1633 }
1634
1635 *flags |= (nhc->nhc_flags & RTNH_F_ONLINK);
1636 if (nhc->nhc_flags & RTNH_F_OFFLOAD)
1637 *flags |= RTNH_F_OFFLOAD;
1638
1639 if (!skip_oif && nhc->nhc_dev &&
1640 nla_put_u32(skb, RTA_OIF, nhc->nhc_dev->ifindex))
1641 goto nla_put_failure;
1642
1643 if (nhc->nhc_lwtstate &&
1644 lwtunnel_fill_encap(skb, nhc->nhc_lwtstate,
1645 RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
1646 goto nla_put_failure;
1647
1648 return 0;
1649
1650nla_put_failure:
1651 return -EMSGSIZE;
1652}
1653EXPORT_SYMBOL_GPL(fib_nexthop_info);
1654
1655#if IS_ENABLED(CONFIG_IP_ROUTE_MULTIPATH) || IS_ENABLED(CONFIG_IPV6)
1656int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc,
1657 int nh_weight, u8 rt_family)
1658{
1659 const struct net_device *dev = nhc->nhc_dev;
1660 struct rtnexthop *rtnh;
1661 unsigned char flags = 0;
1662
1663 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
1664 if (!rtnh)
1665 goto nla_put_failure;
1666
1667 rtnh->rtnh_hops = nh_weight - 1;
1668 rtnh->rtnh_ifindex = dev ? dev->ifindex : 0;
1669
1670 if (fib_nexthop_info(skb, nhc, rt_family, &flags, true) < 0)
1671 goto nla_put_failure;
1672
1673 rtnh->rtnh_flags = flags;
1674
1675
1676 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
1677
1678 return 0;
1679
1680nla_put_failure:
1681 return -EMSGSIZE;
1682}
1683EXPORT_SYMBOL_GPL(fib_add_nexthop);
1684#endif
1685
1686#ifdef CONFIG_IP_ROUTE_MULTIPATH
1687static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
1688{
1689 struct nlattr *mp;
1690
1691 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
1692 if (!mp)
1693 goto nla_put_failure;
1694
1695 if (unlikely(fi->nh)) {
1696 if (nexthop_mpath_fill_node(skb, fi->nh, AF_INET) < 0)
1697 goto nla_put_failure;
1698 goto mp_end;
1699 }
1700
1701 for_nexthops(fi) {
1702 if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight,
1703 AF_INET) < 0)
1704 goto nla_put_failure;
1705#ifdef CONFIG_IP_ROUTE_CLASSID
1706 if (nh->nh_tclassid &&
1707 nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
1708 goto nla_put_failure;
1709#endif
1710 } endfor_nexthops(fi);
1711
1712mp_end:
1713 nla_nest_end(skb, mp);
1714
1715 return 0;
1716
1717nla_put_failure:
1718 return -EMSGSIZE;
1719}
1720#else
1721static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
1722{
1723 return 0;
1724}
1725#endif
1726
1727int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
1728 u32 tb_id, u8 type, __be32 dst, int dst_len, u8 tos,
1729 struct fib_info *fi, unsigned int flags)
1730{
1731 unsigned int nhs = fib_info_num_path(fi);
1732 struct nlmsghdr *nlh;
1733 struct rtmsg *rtm;
1734
1735 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
1736 if (!nlh)
1737 return -EMSGSIZE;
1738
1739 rtm = nlmsg_data(nlh);
1740 rtm->rtm_family = AF_INET;
1741 rtm->rtm_dst_len = dst_len;
1742 rtm->rtm_src_len = 0;
1743 rtm->rtm_tos = tos;
1744 if (tb_id < 256)
1745 rtm->rtm_table = tb_id;
1746 else
1747 rtm->rtm_table = RT_TABLE_COMPAT;
1748 if (nla_put_u32(skb, RTA_TABLE, tb_id))
1749 goto nla_put_failure;
1750 rtm->rtm_type = type;
1751 rtm->rtm_flags = fi->fib_flags;
1752 rtm->rtm_scope = fi->fib_scope;
1753 rtm->rtm_protocol = fi->fib_protocol;
1754
1755 if (rtm->rtm_dst_len &&
1756 nla_put_in_addr(skb, RTA_DST, dst))
1757 goto nla_put_failure;
1758 if (fi->fib_priority &&
1759 nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority))
1760 goto nla_put_failure;
1761 if (rtnetlink_put_metrics(skb, fi->fib_metrics->metrics) < 0)
1762 goto nla_put_failure;
1763
1764 if (fi->fib_prefsrc &&
1765 nla_put_in_addr(skb, RTA_PREFSRC, fi->fib_prefsrc))
1766 goto nla_put_failure;
1767
1768 if (fi->nh) {
1769 if (nla_put_u32(skb, RTA_NH_ID, fi->nh->id))
1770 goto nla_put_failure;
1771 if (nexthop_is_blackhole(fi->nh))
1772 rtm->rtm_type = RTN_BLACKHOLE;
1773 }
1774
1775 if (nhs == 1) {
1776 const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
1777 unsigned char flags = 0;
1778
1779 if (fib_nexthop_info(skb, nhc, AF_INET, &flags, false) < 0)
1780 goto nla_put_failure;
1781
1782 rtm->rtm_flags = flags;
1783#ifdef CONFIG_IP_ROUTE_CLASSID
1784 if (nhc->nhc_family == AF_INET) {
1785 struct fib_nh *nh;
1786
1787 nh = container_of(nhc, struct fib_nh, nh_common);
1788 if (nh->nh_tclassid &&
1789 nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
1790 goto nla_put_failure;
1791 }
1792#endif
1793 } else {
1794 if (fib_add_multipath(skb, fi) < 0)
1795 goto nla_put_failure;
1796 }
1797
1798 nlmsg_end(skb, nlh);
1799 return 0;
1800
1801nla_put_failure:
1802 nlmsg_cancel(skb, nlh);
1803 return -EMSGSIZE;
1804}
1805
1806
1807
1808
1809
1810
1811
1812int fib_sync_down_addr(struct net_device *dev, __be32 local)
1813{
1814 int ret = 0;
1815 unsigned int hash = fib_laddr_hashfn(local);
1816 struct hlist_head *head = &fib_info_laddrhash[hash];
1817 struct net *net = dev_net(dev);
1818 int tb_id = l3mdev_fib_table(dev);
1819 struct fib_info *fi;
1820
1821 if (!fib_info_laddrhash || local == 0)
1822 return 0;
1823
1824 hlist_for_each_entry(fi, head, fib_lhash) {
1825 if (!net_eq(fi->fib_net, net) ||
1826 fi->fib_tb_id != tb_id)
1827 continue;
1828 if (fi->fib_prefsrc == local) {
1829 fi->fib_flags |= RTNH_F_DEAD;
1830 ret++;
1831 }
1832 }
1833 return ret;
1834}
1835
1836static int call_fib_nh_notifiers(struct fib_nh *nh,
1837 enum fib_event_type event_type)
1838{
1839 bool ignore_link_down = ip_ignore_linkdown(nh->fib_nh_dev);
1840 struct fib_nh_notifier_info info = {
1841 .fib_nh = nh,
1842 };
1843
1844 switch (event_type) {
1845 case FIB_EVENT_NH_ADD:
1846 if (nh->fib_nh_flags & RTNH_F_DEAD)
1847 break;
1848 if (ignore_link_down && nh->fib_nh_flags & RTNH_F_LINKDOWN)
1849 break;
1850 return call_fib4_notifiers(dev_net(nh->fib_nh_dev), event_type,
1851 &info.info);
1852 case FIB_EVENT_NH_DEL:
1853 if ((ignore_link_down && nh->fib_nh_flags & RTNH_F_LINKDOWN) ||
1854 (nh->fib_nh_flags & RTNH_F_DEAD))
1855 return call_fib4_notifiers(dev_net(nh->fib_nh_dev),
1856 event_type, &info.info);
1857 default:
1858 break;
1859 }
1860
1861 return NOTIFY_DONE;
1862}
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig)
1875{
1876 struct fnhe_hash_bucket *bucket;
1877 int i;
1878
1879 bucket = rcu_dereference_protected(nhc->nhc_exceptions, 1);
1880 if (!bucket)
1881 return;
1882
1883 for (i = 0; i < FNHE_HASH_SIZE; i++) {
1884 struct fib_nh_exception *fnhe;
1885
1886 for (fnhe = rcu_dereference_protected(bucket[i].chain, 1);
1887 fnhe;
1888 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1)) {
1889 if (fnhe->fnhe_mtu_locked) {
1890 if (new <= fnhe->fnhe_pmtu) {
1891 fnhe->fnhe_pmtu = new;
1892 fnhe->fnhe_mtu_locked = false;
1893 }
1894 } else if (new < fnhe->fnhe_pmtu ||
1895 orig == fnhe->fnhe_pmtu) {
1896 fnhe->fnhe_pmtu = new;
1897 }
1898 }
1899 }
1900}
1901
1902void fib_sync_mtu(struct net_device *dev, u32 orig_mtu)
1903{
1904 unsigned int hash = fib_devindex_hashfn(dev->ifindex);
1905 struct hlist_head *head = &fib_info_devhash[hash];
1906 struct fib_nh *nh;
1907
1908 hlist_for_each_entry(nh, head, nh_hash) {
1909 if (nh->fib_nh_dev == dev)
1910 fib_nhc_update_mtu(&nh->nh_common, dev->mtu, orig_mtu);
1911 }
1912}
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force)
1923{
1924 int ret = 0;
1925 int scope = RT_SCOPE_NOWHERE;
1926 struct fib_info *prev_fi = NULL;
1927 unsigned int hash = fib_devindex_hashfn(dev->ifindex);
1928 struct hlist_head *head = &fib_info_devhash[hash];
1929 struct fib_nh *nh;
1930
1931 if (force)
1932 scope = -1;
1933
1934 hlist_for_each_entry(nh, head, nh_hash) {
1935 struct fib_info *fi = nh->nh_parent;
1936 int dead;
1937
1938 BUG_ON(!fi->fib_nhs);
1939 if (nh->fib_nh_dev != dev || fi == prev_fi)
1940 continue;
1941 prev_fi = fi;
1942 dead = 0;
1943 change_nexthops(fi) {
1944 if (nexthop_nh->fib_nh_flags & RTNH_F_DEAD)
1945 dead++;
1946 else if (nexthop_nh->fib_nh_dev == dev &&
1947 nexthop_nh->fib_nh_scope != scope) {
1948 switch (event) {
1949 case NETDEV_DOWN:
1950 case NETDEV_UNREGISTER:
1951 nexthop_nh->fib_nh_flags |= RTNH_F_DEAD;
1952
1953 case NETDEV_CHANGE:
1954 nexthop_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
1955 break;
1956 }
1957 call_fib_nh_notifiers(nexthop_nh,
1958 FIB_EVENT_NH_DEL);
1959 dead++;
1960 }
1961#ifdef CONFIG_IP_ROUTE_MULTIPATH
1962 if (event == NETDEV_UNREGISTER &&
1963 nexthop_nh->fib_nh_dev == dev) {
1964 dead = fi->fib_nhs;
1965 break;
1966 }
1967#endif
1968 } endfor_nexthops(fi)
1969 if (dead == fi->fib_nhs) {
1970 switch (event) {
1971 case NETDEV_DOWN:
1972 case NETDEV_UNREGISTER:
1973 fi->fib_flags |= RTNH_F_DEAD;
1974
1975 case NETDEV_CHANGE:
1976 fi->fib_flags |= RTNH_F_LINKDOWN;
1977 break;
1978 }
1979 ret++;
1980 }
1981
1982 fib_rebalance(fi);
1983 }
1984
1985 return ret;
1986}
1987
1988
1989static void fib_select_default(const struct flowi4 *flp, struct fib_result *res)
1990{
1991 struct fib_info *fi = NULL, *last_resort = NULL;
1992 struct hlist_head *fa_head = res->fa_head;
1993 struct fib_table *tb = res->table;
1994 u8 slen = 32 - res->prefixlen;
1995 int order = -1, last_idx = -1;
1996 struct fib_alias *fa, *fa1 = NULL;
1997 u32 last_prio = res->fi->fib_priority;
1998 u8 last_tos = 0;
1999
2000 hlist_for_each_entry_rcu(fa, fa_head, fa_list) {
2001 struct fib_info *next_fi = fa->fa_info;
2002 struct fib_nh *nh;
2003
2004 if (fa->fa_slen != slen)
2005 continue;
2006 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
2007 continue;
2008 if (fa->tb_id != tb->tb_id)
2009 continue;
2010 if (next_fi->fib_priority > last_prio &&
2011 fa->fa_tos == last_tos) {
2012 if (last_tos)
2013 continue;
2014 break;
2015 }
2016 if (next_fi->fib_flags & RTNH_F_DEAD)
2017 continue;
2018 last_tos = fa->fa_tos;
2019 last_prio = next_fi->fib_priority;
2020
2021 if (next_fi->fib_scope != res->scope ||
2022 fa->fa_type != RTN_UNICAST)
2023 continue;
2024
2025 nh = fib_info_nh(next_fi, 0);
2026 if (!nh->fib_nh_gw4 || nh->fib_nh_scope != RT_SCOPE_LINK)
2027 continue;
2028
2029 fib_alias_accessed(fa);
2030
2031 if (!fi) {
2032 if (next_fi != res->fi)
2033 break;
2034 fa1 = fa;
2035 } else if (!fib_detect_death(fi, order, &last_resort,
2036 &last_idx, fa1->fa_default)) {
2037 fib_result_assign(res, fi);
2038 fa1->fa_default = order;
2039 goto out;
2040 }
2041 fi = next_fi;
2042 order++;
2043 }
2044
2045 if (order <= 0 || !fi) {
2046 if (fa1)
2047 fa1->fa_default = -1;
2048 goto out;
2049 }
2050
2051 if (!fib_detect_death(fi, order, &last_resort, &last_idx,
2052 fa1->fa_default)) {
2053 fib_result_assign(res, fi);
2054 fa1->fa_default = order;
2055 goto out;
2056 }
2057
2058 if (last_idx >= 0)
2059 fib_result_assign(res, last_resort);
2060 fa1->fa_default = last_idx;
2061out:
2062 return;
2063}
2064
2065
2066
2067
2068
2069
2070
2071int fib_sync_up(struct net_device *dev, unsigned char nh_flags)
2072{
2073 struct fib_info *prev_fi;
2074 unsigned int hash;
2075 struct hlist_head *head;
2076 struct fib_nh *nh;
2077 int ret;
2078
2079 if (!(dev->flags & IFF_UP))
2080 return 0;
2081
2082 if (nh_flags & RTNH_F_DEAD) {
2083 unsigned int flags = dev_get_flags(dev);
2084
2085 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
2086 nh_flags |= RTNH_F_LINKDOWN;
2087 }
2088
2089 prev_fi = NULL;
2090 hash = fib_devindex_hashfn(dev->ifindex);
2091 head = &fib_info_devhash[hash];
2092 ret = 0;
2093
2094 hlist_for_each_entry(nh, head, nh_hash) {
2095 struct fib_info *fi = nh->nh_parent;
2096 int alive;
2097
2098 BUG_ON(!fi->fib_nhs);
2099 if (nh->fib_nh_dev != dev || fi == prev_fi)
2100 continue;
2101
2102 prev_fi = fi;
2103 alive = 0;
2104 change_nexthops(fi) {
2105 if (!(nexthop_nh->fib_nh_flags & nh_flags)) {
2106 alive++;
2107 continue;
2108 }
2109 if (!nexthop_nh->fib_nh_dev ||
2110 !(nexthop_nh->fib_nh_dev->flags & IFF_UP))
2111 continue;
2112 if (nexthop_nh->fib_nh_dev != dev ||
2113 !__in_dev_get_rtnl(dev))
2114 continue;
2115 alive++;
2116 nexthop_nh->fib_nh_flags &= ~nh_flags;
2117 call_fib_nh_notifiers(nexthop_nh, FIB_EVENT_NH_ADD);
2118 } endfor_nexthops(fi)
2119
2120 if (alive > 0) {
2121 fi->fib_flags &= ~nh_flags;
2122 ret++;
2123 }
2124
2125 fib_rebalance(fi);
2126 }
2127
2128 return ret;
2129}
2130
2131#ifdef CONFIG_IP_ROUTE_MULTIPATH
2132static bool fib_good_nh(const struct fib_nh *nh)
2133{
2134 int state = NUD_REACHABLE;
2135
2136 if (nh->fib_nh_scope == RT_SCOPE_LINK) {
2137 struct neighbour *n;
2138
2139 rcu_read_lock_bh();
2140
2141 if (likely(nh->fib_nh_gw_family == AF_INET))
2142 n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev,
2143 (__force u32)nh->fib_nh_gw4);
2144 else if (nh->fib_nh_gw_family == AF_INET6)
2145 n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev,
2146 &nh->fib_nh_gw6);
2147 else
2148 n = NULL;
2149 if (n)
2150 state = n->nud_state;
2151
2152 rcu_read_unlock_bh();
2153 }
2154
2155 return !!(state & NUD_VALID);
2156}
2157
2158void fib_select_multipath(struct fib_result *res, int hash)
2159{
2160 struct fib_info *fi = res->fi;
2161 struct net *net = fi->fib_net;
2162 bool first = false;
2163
2164 if (unlikely(res->fi->nh)) {
2165 nexthop_path_fib_result(res, hash);
2166 return;
2167 }
2168
2169 change_nexthops(fi) {
2170 if (net->ipv4.sysctl_fib_multipath_use_neigh) {
2171 if (!fib_good_nh(nexthop_nh))
2172 continue;
2173 if (!first) {
2174 res->nh_sel = nhsel;
2175 res->nhc = &nexthop_nh->nh_common;
2176 first = true;
2177 }
2178 }
2179
2180 if (hash > atomic_read(&nexthop_nh->fib_nh_upper_bound))
2181 continue;
2182
2183 res->nh_sel = nhsel;
2184 res->nhc = &nexthop_nh->nh_common;
2185 return;
2186 } endfor_nexthops(fi);
2187}
2188#endif
2189
2190void fib_select_path(struct net *net, struct fib_result *res,
2191 struct flowi4 *fl4, const struct sk_buff *skb)
2192{
2193 if (fl4->flowi4_oif && !(fl4->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF))
2194 goto check_saddr;
2195
2196#ifdef CONFIG_IP_ROUTE_MULTIPATH
2197 if (fib_info_num_path(res->fi) > 1) {
2198 int h = fib_multipath_hash(net, fl4, skb, NULL);
2199
2200 fib_select_multipath(res, h);
2201 }
2202 else
2203#endif
2204 if (!res->prefixlen &&
2205 res->table->tb_num_default > 1 &&
2206 res->type == RTN_UNICAST)
2207 fib_select_default(fl4, res);
2208
2209check_saddr:
2210 if (!fl4->saddr)
2211 fl4->saddr = fib_result_prefsrc(net, res);
2212}
2213
