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printf: Remove unused 'bprintf'
[drm/drm-misc.git] / net / ipv4 / fib_semantics.c
blobd2cee5c314f5e76530ac564f49b433822bb0a272
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * IPv4 Forwarding Information Base: semantics.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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 #include <linux/hash.h>
33 #include <linux/nospec.h>
34
35 #include <net/arp.h>
36 #include <net/inet_dscp.h>
37 #include <net/ip.h>
38 #include <net/protocol.h>
39 #include <net/route.h>
40 #include <net/tcp.h>
41 #include <net/sock.h>
42 #include <net/ip_fib.h>
43 #include <net/ip6_fib.h>
44 #include <net/nexthop.h>
45 #include <net/netlink.h>
46 #include <net/rtnh.h>
47 #include <net/lwtunnel.h>
48 #include <net/fib_notifier.h>
49 #include <net/addrconf.h>
50
51 #include "fib_lookup.h"
52
53 static struct hlist_head *fib_info_hash;
54 static struct hlist_head *fib_info_laddrhash;
55 static unsigned int fib_info_hash_size;
56 static unsigned int fib_info_hash_bits;
57 static unsigned int fib_info_cnt;
58
59 /* for_nexthops and change_nexthops only used when nexthop object
60 * is not set in a fib_info. The logic within can reference fib_nh.
61 */
62 #ifdef CONFIG_IP_ROUTE_MULTIPATH
63
64 #define for_nexthops(fi) { \
65 int nhsel; const struct fib_nh *nh; \
66 for (nhsel = 0, nh = (fi)->fib_nh; \
67 nhsel < fib_info_num_path((fi)); \
68 nh++, nhsel++)
69
70 #define change_nexthops(fi) { \
71 int nhsel; struct fib_nh *nexthop_nh; \
72 for (nhsel = 0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
73 nhsel < fib_info_num_path((fi)); \
74 nexthop_nh++, nhsel++)
75
76 #else /* CONFIG_IP_ROUTE_MULTIPATH */
77
78 /* Hope, that gcc will optimize it to get rid of dummy loop */
79
80 #define for_nexthops(fi) { \
81 int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \
82 for (nhsel = 0; nhsel < 1; nhsel++)
83
84 #define change_nexthops(fi) { \
85 int nhsel; \
86 struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
87 for (nhsel = 0; nhsel < 1; nhsel++)
88
89 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
90
91 #define endfor_nexthops(fi) }
92
93
94 const struct fib_prop fib_props[RTN_MAX + 1] = {
95 [RTN_UNSPEC] = {
96 .error = 0,
97 .scope = RT_SCOPE_NOWHERE,
98 },
99 [RTN_UNICAST] = {
100 .error = 0,
101 .scope = RT_SCOPE_UNIVERSE,
102 },
103 [RTN_LOCAL] = {
104 .error = 0,
105 .scope = RT_SCOPE_HOST,
106 },
107 [RTN_BROADCAST] = {
108 .error = 0,
109 .scope = RT_SCOPE_LINK,
110 },
111 [RTN_ANYCAST] = {
112 .error = 0,
113 .scope = RT_SCOPE_LINK,
114 },
115 [RTN_MULTICAST] = {
116 .error = 0,
117 .scope = RT_SCOPE_UNIVERSE,
118 },
119 [RTN_BLACKHOLE] = {
120 .error = -EINVAL,
121 .scope = RT_SCOPE_UNIVERSE,
122 },
123 [RTN_UNREACHABLE] = {
124 .error = -EHOSTUNREACH,
125 .scope = RT_SCOPE_UNIVERSE,
126 },
127 [RTN_PROHIBIT] = {
128 .error = -EACCES,
129 .scope = RT_SCOPE_UNIVERSE,
130 },
131 [RTN_THROW] = {
132 .error = -EAGAIN,
133 .scope = RT_SCOPE_UNIVERSE,
134 },
135 [RTN_NAT] = {
136 .error = -EINVAL,
137 .scope = RT_SCOPE_NOWHERE,
138 },
139 [RTN_XRESOLVE] = {
140 .error = -EINVAL,
141 .scope = RT_SCOPE_NOWHERE,
142 },
143 };
144
145 static void rt_fibinfo_free(struct rtable __rcu **rtp)
146 {
147 struct rtable *rt = rcu_dereference_protected(*rtp, 1);
148
149 if (!rt)
150 return;
151
152 /* Not even needed : RCU_INIT_POINTER(*rtp, NULL);
153 * because we waited an RCU grace period before calling
154 * free_fib_info_rcu()
155 */
156
157 dst_dev_put(&rt->dst);
158 dst_release_immediate(&rt->dst);
159 }
160
161 static void free_nh_exceptions(struct fib_nh_common *nhc)
162 {
163 struct fnhe_hash_bucket *hash;
164 int i;
165
166 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1);
167 if (!hash)
168 return;
169 for (i = 0; i < FNHE_HASH_SIZE; i++) {
170 struct fib_nh_exception *fnhe;
171
172 fnhe = rcu_dereference_protected(hash[i].chain, 1);
173 while (fnhe) {
174 struct fib_nh_exception *next;
175
176 next = rcu_dereference_protected(fnhe->fnhe_next, 1);
177
178 rt_fibinfo_free(&fnhe->fnhe_rth_input);
179 rt_fibinfo_free(&fnhe->fnhe_rth_output);
180
181 kfree(fnhe);
182
183 fnhe = next;
184 }
185 }
186 kfree(hash);
187 }
188
189 static void rt_fibinfo_free_cpus(struct rtable __rcu * __percpu *rtp)
190 {
191 int cpu;
192
193 if (!rtp)
194 return;
195
196 for_each_possible_cpu(cpu) {
197 struct rtable *rt;
198
199 rt = rcu_dereference_protected(*per_cpu_ptr(rtp, cpu), 1);
200 if (rt) {
201 dst_dev_put(&rt->dst);
202 dst_release_immediate(&rt->dst);
203 }
204 }
205 free_percpu(rtp);
206 }
207
208 void fib_nh_common_release(struct fib_nh_common *nhc)
209 {
210 netdev_put(nhc->nhc_dev, &nhc->nhc_dev_tracker);
211 lwtstate_put(nhc->nhc_lwtstate);
212 rt_fibinfo_free_cpus(nhc->nhc_pcpu_rth_output);
213 rt_fibinfo_free(&nhc->nhc_rth_input);
214 free_nh_exceptions(nhc);
215 }
216 EXPORT_SYMBOL_GPL(fib_nh_common_release);
217
218 void fib_nh_release(struct net *net, struct fib_nh *fib_nh)
219 {
220 #ifdef CONFIG_IP_ROUTE_CLASSID
221 if (fib_nh->nh_tclassid)
222 atomic_dec(&net->ipv4.fib_num_tclassid_users);
223 #endif
224 fib_nh_common_release(&fib_nh->nh_common);
225 }
226
227 /* Release a nexthop info record */
228 static void free_fib_info_rcu(struct rcu_head *head)
229 {
230 struct fib_info *fi = container_of(head, struct fib_info, rcu);
231
232 if (fi->nh) {
233 nexthop_put(fi->nh);
234 } else {
235 change_nexthops(fi) {
236 fib_nh_release(fi->fib_net, nexthop_nh);
237 } endfor_nexthops(fi);
238 }
239
240 ip_fib_metrics_put(fi->fib_metrics);
241
242 kfree(fi);
243 }
244
245 void free_fib_info(struct fib_info *fi)
246 {
247 if (fi->fib_dead == 0) {
248 pr_warn("Freeing alive fib_info %p\n", fi);
249 return;
250 }
251
252 call_rcu_hurry(&fi->rcu, free_fib_info_rcu);
253 }
254 EXPORT_SYMBOL_GPL(free_fib_info);
255
256 void fib_release_info(struct fib_info *fi)
257 {
258 ASSERT_RTNL();
259 if (fi && refcount_dec_and_test(&fi->fib_treeref)) {
260 hlist_del(&fi->fib_hash);
261
262 fib_info_cnt--;
263
264 if (fi->fib_prefsrc)
265 hlist_del(&fi->fib_lhash);
266 if (fi->nh) {
267 list_del(&fi->nh_list);
268 } else {
269 change_nexthops(fi) {
270 if (!nexthop_nh->fib_nh_dev)
271 continue;
272 hlist_del_rcu(&nexthop_nh->nh_hash);
273 } endfor_nexthops(fi)
274 }
275 /* Paired with READ_ONCE() from fib_table_lookup() */
276 WRITE_ONCE(fi->fib_dead, 1);
277 fib_info_put(fi);
278 }
279 }
280
281 static inline int nh_comp(struct fib_info *fi, struct fib_info *ofi)
282 {
283 const struct fib_nh *onh;
284
285 if (fi->nh || ofi->nh)
286 return nexthop_cmp(fi->nh, ofi->nh) ? 0 : -1;
287
288 if (ofi->fib_nhs == 0)
289 return 0;
290
291 for_nexthops(fi) {
292 onh = fib_info_nh(ofi, nhsel);
293
294 if (nh->fib_nh_oif != onh->fib_nh_oif ||
295 nh->fib_nh_gw_family != onh->fib_nh_gw_family ||
296 nh->fib_nh_scope != onh->fib_nh_scope ||
297 #ifdef CONFIG_IP_ROUTE_MULTIPATH
298 nh->fib_nh_weight != onh->fib_nh_weight ||
299 #endif
300 #ifdef CONFIG_IP_ROUTE_CLASSID
301 nh->nh_tclassid != onh->nh_tclassid ||
302 #endif
303 lwtunnel_cmp_encap(nh->fib_nh_lws, onh->fib_nh_lws) ||
304 ((nh->fib_nh_flags ^ onh->fib_nh_flags) & ~RTNH_COMPARE_MASK))
305 return -1;
306
307 if (nh->fib_nh_gw_family == AF_INET &&
308 nh->fib_nh_gw4 != onh->fib_nh_gw4)
309 return -1;
310
311 if (nh->fib_nh_gw_family == AF_INET6 &&
312 ipv6_addr_cmp(&nh->fib_nh_gw6, &onh->fib_nh_gw6))
313 return -1;
314 } endfor_nexthops(fi);
315 return 0;
316 }
317
318 static struct hlist_head *fib_nh_head(struct net_device *dev)
319 {
320 return &dev->fib_nh_head;
321 }
322
323 static unsigned int fib_info_hashfn_1(int init_val, u8 protocol, u8 scope,
324 u32 prefsrc, u32 priority)
325 {
326 unsigned int val = init_val;
327
328 val ^= (protocol << 8) | scope;
329 val ^= prefsrc;
330 val ^= priority;
331
332 return val;
333 }
334
335 static unsigned int fib_info_hashfn_result(const struct net *net,
336 unsigned int val)
337 {
338 return hash_32(val ^ net_hash_mix(net), fib_info_hash_bits);
339 }
340
341 static inline unsigned int fib_info_hashfn(struct fib_info *fi)
342 {
343 unsigned int val;
344
345 val = fib_info_hashfn_1(fi->fib_nhs, fi->fib_protocol,
346 fi->fib_scope, (__force u32)fi->fib_prefsrc,
347 fi->fib_priority);
348
349 if (fi->nh) {
350 val ^= fi->nh->id;
351 } else {
352 for_nexthops(fi) {
353 val ^= nh->fib_nh_oif;
354 } endfor_nexthops(fi)
355 }
356
357 return fib_info_hashfn_result(fi->fib_net, val);
358 }
359
360 /* no metrics, only nexthop id */
361 static struct fib_info *fib_find_info_nh(struct net *net,
362 const struct fib_config *cfg)
363 {
364 struct hlist_head *head;
365 struct fib_info *fi;
366 unsigned int hash;
367
368 hash = fib_info_hashfn_1(cfg->fc_nh_id,
369 cfg->fc_protocol, cfg->fc_scope,
370 (__force u32)cfg->fc_prefsrc,
371 cfg->fc_priority);
372 hash = fib_info_hashfn_result(net, hash);
373 head = &fib_info_hash[hash];
374
375 hlist_for_each_entry(fi, head, fib_hash) {
376 if (!net_eq(fi->fib_net, net))
377 continue;
378 if (!fi->nh || fi->nh->id != cfg->fc_nh_id)
379 continue;
380 if (cfg->fc_protocol == fi->fib_protocol &&
381 cfg->fc_scope == fi->fib_scope &&
382 cfg->fc_prefsrc == fi->fib_prefsrc &&
383 cfg->fc_priority == fi->fib_priority &&
384 cfg->fc_type == fi->fib_type &&
385 cfg->fc_table == fi->fib_tb_id &&
386 !((cfg->fc_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK))
387 return fi;
388 }
389
390 return NULL;
391 }
392
393 static struct fib_info *fib_find_info(struct fib_info *nfi)
394 {
395 struct hlist_head *head;
396 struct fib_info *fi;
397 unsigned int hash;
398
399 hash = fib_info_hashfn(nfi);
400 head = &fib_info_hash[hash];
401
402 hlist_for_each_entry(fi, head, fib_hash) {
403 if (!net_eq(fi->fib_net, nfi->fib_net))
404 continue;
405 if (fi->fib_nhs != nfi->fib_nhs)
406 continue;
407 if (nfi->fib_protocol == fi->fib_protocol &&
408 nfi->fib_scope == fi->fib_scope &&
409 nfi->fib_prefsrc == fi->fib_prefsrc &&
410 nfi->fib_priority == fi->fib_priority &&
411 nfi->fib_type == fi->fib_type &&
412 nfi->fib_tb_id == fi->fib_tb_id &&
413 memcmp(nfi->fib_metrics, fi->fib_metrics,
414 sizeof(u32) * RTAX_MAX) == 0 &&
415 !((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK) &&
416 nh_comp(fi, nfi) == 0)
417 return fi;
418 }
419
420 return NULL;
421 }
422
423 /* Check, that the gateway is already configured.
424 * Used only by redirect accept routine, under rcu_read_lock();
425 */
426 int ip_fib_check_default(__be32 gw, struct net_device *dev)
427 {
428 struct hlist_head *head;
429 struct fib_nh *nh;
430
431 head = fib_nh_head(dev);
432
433 hlist_for_each_entry_rcu(nh, head, nh_hash) {
434 DEBUG_NET_WARN_ON_ONCE(nh->fib_nh_dev != dev);
435 if (nh->fib_nh_gw4 == gw &&
436 !(nh->fib_nh_flags & RTNH_F_DEAD)) {
437 return 0;
438 }
439 }
440
441 return -1;
442 }
443
444 size_t fib_nlmsg_size(struct fib_info *fi)
445 {
446 size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
447 + nla_total_size(4) /* RTA_TABLE */
448 + nla_total_size(4) /* RTA_DST */
449 + nla_total_size(4) /* RTA_PRIORITY */
450 + nla_total_size(4) /* RTA_PREFSRC */
451 + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
452 unsigned int nhs = fib_info_num_path(fi);
453
454 /* space for nested metrics */
455 payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
456
457 if (fi->nh)
458 payload += nla_total_size(4); /* RTA_NH_ID */
459
460 if (nhs) {
461 size_t nh_encapsize = 0;
462 /* Also handles the special case nhs == 1 */
463
464 /* each nexthop is packed in an attribute */
465 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
466 unsigned int i;
467
468 /* may contain flow and gateway attribute */
469 nhsize += 2 * nla_total_size(4);
470
471 /* grab encap info */
472 for (i = 0; i < fib_info_num_path(fi); i++) {
473 struct fib_nh_common *nhc = fib_info_nhc(fi, i);
474
475 if (nhc->nhc_lwtstate) {
476 /* RTA_ENCAP_TYPE */
477 nh_encapsize += lwtunnel_get_encap_size(
478 nhc->nhc_lwtstate);
479 /* RTA_ENCAP */
480 nh_encapsize += nla_total_size(2);
481 }
482 }
483
484 /* all nexthops are packed in a nested attribute */
485 payload += nla_total_size((nhs * nhsize) + nh_encapsize);
486
487 }
488
489 return payload;
490 }
491
492 void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
493 int dst_len, u32 tb_id, const struct nl_info *info,
494 unsigned int nlm_flags)
495 {
496 struct fib_rt_info fri;
497 struct sk_buff *skb;
498 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
499 int err = -ENOBUFS;
500
501 skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL);
502 if (!skb)
503 goto errout;
504
505 fri.fi = fa->fa_info;
506 fri.tb_id = tb_id;
507 fri.dst = key;
508 fri.dst_len = dst_len;
509 fri.dscp = fa->fa_dscp;
510 fri.type = fa->fa_type;
511 fri.offload = READ_ONCE(fa->offload);
512 fri.trap = READ_ONCE(fa->trap);
513 fri.offload_failed = READ_ONCE(fa->offload_failed);
514 err = fib_dump_info(skb, info->portid, seq, event, &fri, nlm_flags);
515 if (err < 0) {
516 /* -EMSGSIZE implies BUG in fib_nlmsg_size() */
517 WARN_ON(err == -EMSGSIZE);
518 kfree_skb(skb);
519 goto errout;
520 }
521 rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_IPV4_ROUTE,
522 info->nlh, GFP_KERNEL);
523 return;
524 errout:
525 rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err);
526 }
527
528 static int fib_detect_death(struct fib_info *fi, int order,
529 struct fib_info **last_resort, int *last_idx,
530 int dflt)
531 {
532 const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
533 struct neighbour *n;
534 int state = NUD_NONE;
535
536 if (likely(nhc->nhc_gw_family == AF_INET))
537 n = neigh_lookup(&arp_tbl, &nhc->nhc_gw.ipv4, nhc->nhc_dev);
538 else if (nhc->nhc_gw_family == AF_INET6)
539 n = neigh_lookup(ipv6_stub->nd_tbl, &nhc->nhc_gw.ipv6,
540 nhc->nhc_dev);
541 else
542 n = NULL;
543
544 if (n) {
545 state = READ_ONCE(n->nud_state);
546 neigh_release(n);
547 } else {
548 return 0;
549 }
550 if (state == NUD_REACHABLE)
551 return 0;
552 if ((state & NUD_VALID) && order != dflt)
553 return 0;
554 if ((state & NUD_VALID) ||
555 (*last_idx < 0 && order > dflt && state != NUD_INCOMPLETE)) {
556 *last_resort = fi;
557 *last_idx = order;
558 }
559 return 1;
560 }
561
562 int fib_nh_common_init(struct net *net, struct fib_nh_common *nhc,
563 struct nlattr *encap, u16 encap_type,
564 void *cfg, gfp_t gfp_flags,
565 struct netlink_ext_ack *extack)
566 {
567 int err;
568
569 nhc->nhc_pcpu_rth_output = alloc_percpu_gfp(struct rtable __rcu *,
570 gfp_flags);
571 if (!nhc->nhc_pcpu_rth_output)
572 return -ENOMEM;
573
574 if (encap) {
575 struct lwtunnel_state *lwtstate;
576
577 if (encap_type == LWTUNNEL_ENCAP_NONE) {
578 NL_SET_ERR_MSG(extack, "LWT encap type not specified");
579 err = -EINVAL;
580 goto lwt_failure;
581 }
582 err = lwtunnel_build_state(net, encap_type, encap,
583 nhc->nhc_family, cfg, &lwtstate,
584 extack);
585 if (err)
586 goto lwt_failure;
587
588 nhc->nhc_lwtstate = lwtstate_get(lwtstate);
589 }
590
591 return 0;
592
593 lwt_failure:
594 rt_fibinfo_free_cpus(nhc->nhc_pcpu_rth_output);
595 nhc->nhc_pcpu_rth_output = NULL;
596 return err;
597 }
598 EXPORT_SYMBOL_GPL(fib_nh_common_init);
599
600 int fib_nh_init(struct net *net, struct fib_nh *nh,
601 struct fib_config *cfg, int nh_weight,
602 struct netlink_ext_ack *extack)
603 {
604 int err;
605
606 nh->fib_nh_family = AF_INET;
607
608 err = fib_nh_common_init(net, &nh->nh_common, cfg->fc_encap,
609 cfg->fc_encap_type, cfg, GFP_KERNEL, extack);
610 if (err)
611 return err;
612
613 nh->fib_nh_oif = cfg->fc_oif;
614 nh->fib_nh_gw_family = cfg->fc_gw_family;
615 if (cfg->fc_gw_family == AF_INET)
616 nh->fib_nh_gw4 = cfg->fc_gw4;
617 else if (cfg->fc_gw_family == AF_INET6)
618 nh->fib_nh_gw6 = cfg->fc_gw6;
619
620 nh->fib_nh_flags = cfg->fc_flags;
621
622 #ifdef CONFIG_IP_ROUTE_CLASSID
623 nh->nh_tclassid = cfg->fc_flow;
624 if (nh->nh_tclassid)
625 atomic_inc(&net->ipv4.fib_num_tclassid_users);
626 #endif
627 #ifdef CONFIG_IP_ROUTE_MULTIPATH
628 nh->fib_nh_weight = nh_weight;
629 #endif
630 return 0;
631 }
632
633 #ifdef CONFIG_IP_ROUTE_MULTIPATH
634
635 static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining,
636 struct netlink_ext_ack *extack)
637 {
638 int nhs = 0;
639
640 while (rtnh_ok(rtnh, remaining)) {
641 nhs++;
642 rtnh = rtnh_next(rtnh, &remaining);
643 }
644
645 /* leftover implies invalid nexthop configuration, discard it */
646 if (remaining > 0) {
647 NL_SET_ERR_MSG(extack,
648 "Invalid nexthop configuration - extra data after nexthops");
649 nhs = 0;
650 }
651
652 return nhs;
653 }
654
655 static int fib_gw_from_attr(__be32 *gw, struct nlattr *nla,
656 struct netlink_ext_ack *extack)
657 {
658 if (nla_len(nla) < sizeof(*gw)) {
659 NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_GATEWAY");
660 return -EINVAL;
661 }
662
663 *gw = nla_get_in_addr(nla);
664
665 return 0;
666 }
667
668 /* only called when fib_nh is integrated into fib_info */
669 static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
670 int remaining, struct fib_config *cfg,
671 struct netlink_ext_ack *extack)
672 {
673 struct net *net = fi->fib_net;
674 struct fib_config fib_cfg;
675 struct fib_nh *nh;
676 int ret;
677
678 change_nexthops(fi) {
679 int attrlen;
680
681 memset(&fib_cfg, 0, sizeof(fib_cfg));
682
683 if (!rtnh_ok(rtnh, remaining)) {
684 NL_SET_ERR_MSG(extack,
685 "Invalid nexthop configuration - extra data after nexthop");
686 return -EINVAL;
687 }
688
689 if (rtnh->rtnh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) {
690 NL_SET_ERR_MSG(extack,
691 "Invalid flags for nexthop - can not contain DEAD or LINKDOWN");
692 return -EINVAL;
693 }
694
695 fib_cfg.fc_flags = (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags;
696 fib_cfg.fc_oif = rtnh->rtnh_ifindex;
697
698 attrlen = rtnh_attrlen(rtnh);
699 if (attrlen > 0) {
700 struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh);
701
702 nla = nla_find(attrs, attrlen, RTA_GATEWAY);
703 nlav = nla_find(attrs, attrlen, RTA_VIA);
704 if (nla && nlav) {
705 NL_SET_ERR_MSG(extack,
706 "Nexthop configuration can not contain both GATEWAY and VIA");
707 return -EINVAL;
708 }
709 if (nla) {
710 ret = fib_gw_from_attr(&fib_cfg.fc_gw4, nla,
711 extack);
712 if (ret)
713 goto errout;
714
715 if (fib_cfg.fc_gw4)
716 fib_cfg.fc_gw_family = AF_INET;
717 } else if (nlav) {
718 ret = fib_gw_from_via(&fib_cfg, nlav, extack);
719 if (ret)
720 goto errout;
721 }
722
723 nla = nla_find(attrs, attrlen, RTA_FLOW);
724 if (nla) {
725 if (nla_len(nla) < sizeof(u32)) {
726 NL_SET_ERR_MSG(extack, "Invalid RTA_FLOW");
727 return -EINVAL;
728 }
729 fib_cfg.fc_flow = nla_get_u32(nla);
730 }
731
732 fib_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
733 /* RTA_ENCAP_TYPE length checked in
734 * lwtunnel_valid_encap_type_attr
735 */
736 nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
737 if (nla)
738 fib_cfg.fc_encap_type = nla_get_u16(nla);
739 }
740
741 ret = fib_nh_init(net, nexthop_nh, &fib_cfg,
742 rtnh->rtnh_hops + 1, extack);
743 if (ret)
744 goto errout;
745
746 rtnh = rtnh_next(rtnh, &remaining);
747 } endfor_nexthops(fi);
748
749 ret = -EINVAL;
750 nh = fib_info_nh(fi, 0);
751 if (cfg->fc_oif && nh->fib_nh_oif != cfg->fc_oif) {
752 NL_SET_ERR_MSG(extack,
753 "Nexthop device index does not match RTA_OIF");
754 goto errout;
755 }
756 if (cfg->fc_gw_family) {
757 if (cfg->fc_gw_family != nh->fib_nh_gw_family ||
758 (cfg->fc_gw_family == AF_INET &&
759 nh->fib_nh_gw4 != cfg->fc_gw4) ||
760 (cfg->fc_gw_family == AF_INET6 &&
761 ipv6_addr_cmp(&nh->fib_nh_gw6, &cfg->fc_gw6))) {
762 NL_SET_ERR_MSG(extack,
763 "Nexthop gateway does not match RTA_GATEWAY or RTA_VIA");
764 goto errout;
765 }
766 }
767 #ifdef CONFIG_IP_ROUTE_CLASSID
768 if (cfg->fc_flow && nh->nh_tclassid != cfg->fc_flow) {
769 NL_SET_ERR_MSG(extack,
770 "Nexthop class id does not match RTA_FLOW");
771 goto errout;
772 }
773 #endif
774 ret = 0;
775 errout:
776 return ret;
777 }
778
779 /* only called when fib_nh is integrated into fib_info */
780 static void fib_rebalance(struct fib_info *fi)
781 {
782 int total;
783 int w;
784
785 if (fib_info_num_path(fi) < 2)
786 return;
787
788 total = 0;
789 for_nexthops(fi) {
790 if (nh->fib_nh_flags & RTNH_F_DEAD)
791 continue;
792
793 if (ip_ignore_linkdown(nh->fib_nh_dev) &&
794 nh->fib_nh_flags & RTNH_F_LINKDOWN)
795 continue;
796
797 total += nh->fib_nh_weight;
798 } endfor_nexthops(fi);
799
800 w = 0;
801 change_nexthops(fi) {
802 int upper_bound;
803
804 if (nexthop_nh->fib_nh_flags & RTNH_F_DEAD) {
805 upper_bound = -1;
806 } else if (ip_ignore_linkdown(nexthop_nh->fib_nh_dev) &&
807 nexthop_nh->fib_nh_flags & RTNH_F_LINKDOWN) {
808 upper_bound = -1;
809 } else {
810 w += nexthop_nh->fib_nh_weight;
811 upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31,
812 total) - 1;
813 }
814
815 atomic_set(&nexthop_nh->fib_nh_upper_bound, upper_bound);
816 } endfor_nexthops(fi);
817 }
818 #else /* CONFIG_IP_ROUTE_MULTIPATH */
819
820 static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
821 int remaining, struct fib_config *cfg,
822 struct netlink_ext_ack *extack)
823 {
824 NL_SET_ERR_MSG(extack, "Multipath support not enabled in kernel");
825
826 return -EINVAL;
827 }
828
829 #define fib_rebalance(fi) do { } while (0)
830
831 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
832
833 static int fib_encap_match(struct net *net, u16 encap_type,
834 struct nlattr *encap,
835 const struct fib_nh *nh,
836 const struct fib_config *cfg,
837 struct netlink_ext_ack *extack)
838 {
839 struct lwtunnel_state *lwtstate;
840 int ret, result = 0;
841
842 if (encap_type == LWTUNNEL_ENCAP_NONE)
843 return 0;
844
845 ret = lwtunnel_build_state(net, encap_type, encap, AF_INET,
846 cfg, &lwtstate, extack);
847 if (!ret) {
848 result = lwtunnel_cmp_encap(lwtstate, nh->fib_nh_lws);
849 lwtstate_free(lwtstate);
850 }
851
852 return result;
853 }
854
855 int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi,
856 struct netlink_ext_ack *extack)
857 {
858 #ifdef CONFIG_IP_ROUTE_MULTIPATH
859 struct rtnexthop *rtnh;
860 int remaining;
861 #endif
862
863 if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority)
864 return 1;
865
866 if (cfg->fc_nh_id) {
867 if (fi->nh && cfg->fc_nh_id == fi->nh->id)
868 return 0;
869 return 1;
870 }
871
872 if (fi->nh) {
873 if (cfg->fc_oif || cfg->fc_gw_family || cfg->fc_mp)
874 return 1;
875 return 0;
876 }
877
878 if (cfg->fc_oif || cfg->fc_gw_family) {
879 struct fib_nh *nh;
880
881 nh = fib_info_nh(fi, 0);
882 if (cfg->fc_encap) {
883 if (fib_encap_match(net, cfg->fc_encap_type,
884 cfg->fc_encap, nh, cfg, extack))
885 return 1;
886 }
887 #ifdef CONFIG_IP_ROUTE_CLASSID
888 if (cfg->fc_flow &&
889 cfg->fc_flow != nh->nh_tclassid)
890 return 1;
891 #endif
892 if ((cfg->fc_oif && cfg->fc_oif != nh->fib_nh_oif) ||
893 (cfg->fc_gw_family &&
894 cfg->fc_gw_family != nh->fib_nh_gw_family))
895 return 1;
896
897 if (cfg->fc_gw_family == AF_INET &&
898 cfg->fc_gw4 != nh->fib_nh_gw4)
899 return 1;
900
901 if (cfg->fc_gw_family == AF_INET6 &&
902 ipv6_addr_cmp(&cfg->fc_gw6, &nh->fib_nh_gw6))
903 return 1;
904
905 return 0;
906 }
907
908 #ifdef CONFIG_IP_ROUTE_MULTIPATH
909 if (!cfg->fc_mp)
910 return 0;
911
912 rtnh = cfg->fc_mp;
913 remaining = cfg->fc_mp_len;
914
915 for_nexthops(fi) {
916 int attrlen;
917
918 if (!rtnh_ok(rtnh, remaining))
919 return -EINVAL;
920
921 if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->fib_nh_oif)
922 return 1;
923
924 attrlen = rtnh_attrlen(rtnh);
925 if (attrlen > 0) {
926 struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh);
927 int err;
928
929 nla = nla_find(attrs, attrlen, RTA_GATEWAY);
930 nlav = nla_find(attrs, attrlen, RTA_VIA);
931 if (nla && nlav) {
932 NL_SET_ERR_MSG(extack,
933 "Nexthop configuration can not contain both GATEWAY and VIA");
934 return -EINVAL;
935 }
936
937 if (nla) {
938 __be32 gw;
939
940 err = fib_gw_from_attr(&gw, nla, extack);
941 if (err)
942 return err;
943
944 if (nh->fib_nh_gw_family != AF_INET ||
945 gw != nh->fib_nh_gw4)
946 return 1;
947 } else if (nlav) {
948 struct fib_config cfg2;
949
950 err = fib_gw_from_via(&cfg2, nlav, extack);
951 if (err)
952 return err;
953
954 switch (nh->fib_nh_gw_family) {
955 case AF_INET:
956 if (cfg2.fc_gw_family != AF_INET ||
957 cfg2.fc_gw4 != nh->fib_nh_gw4)
958 return 1;
959 break;
960 case AF_INET6:
961 if (cfg2.fc_gw_family != AF_INET6 ||
962 ipv6_addr_cmp(&cfg2.fc_gw6,
963 &nh->fib_nh_gw6))
964 return 1;
965 break;
966 }
967 }
968
969 #ifdef CONFIG_IP_ROUTE_CLASSID
970 nla = nla_find(attrs, attrlen, RTA_FLOW);
971 if (nla) {
972 if (nla_len(nla) < sizeof(u32)) {
973 NL_SET_ERR_MSG(extack, "Invalid RTA_FLOW");
974 return -EINVAL;
975 }
976 if (nla_get_u32(nla) != nh->nh_tclassid)
977 return 1;
978 }
979 #endif
980 }
981
982 rtnh = rtnh_next(rtnh, &remaining);
983 } endfor_nexthops(fi);
984 #endif
985 return 0;
986 }
987
988 bool fib_metrics_match(struct fib_config *cfg, struct fib_info *fi)
989 {
990 struct nlattr *nla;
991 int remaining;
992
993 if (!cfg->fc_mx)
994 return true;
995
996 nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
997 int type = nla_type(nla);
998 u32 fi_val, val;
999
1000 if (!type)
1001 continue;
1002 if (type > RTAX_MAX)
1003 return false;
1004
1005 type = array_index_nospec(type, RTAX_MAX + 1);
1006 if (type == RTAX_CC_ALGO) {
1007 char tmp[TCP_CA_NAME_MAX];
1008 bool ecn_ca = false;
1009
1010 nla_strscpy(tmp, nla, sizeof(tmp));
1011 val = tcp_ca_get_key_by_name(tmp, &ecn_ca);
1012 } else {
1013 if (nla_len(nla) != sizeof(u32))
1014 return false;
1015 val = nla_get_u32(nla);
1016 }
1017
1018 fi_val = fi->fib_metrics->metrics[type - 1];
1019 if (type == RTAX_FEATURES)
1020 fi_val &= ~DST_FEATURE_ECN_CA;
1021
1022 if (fi_val != val)
1023 return false;
1024 }
1025
1026 return true;
1027 }
1028
1029 static int fib_check_nh_v6_gw(struct net *net, struct fib_nh *nh,
1030 u32 table, struct netlink_ext_ack *extack)
1031 {
1032 struct fib6_config cfg = {
1033 .fc_table = table,
1034 .fc_flags = nh->fib_nh_flags | RTF_GATEWAY,
1035 .fc_ifindex = nh->fib_nh_oif,
1036 .fc_gateway = nh->fib_nh_gw6,
1037 };
1038 struct fib6_nh fib6_nh = {};
1039 int err;
1040
1041 err = ipv6_stub->fib6_nh_init(net, &fib6_nh, &cfg, GFP_KERNEL, extack);
1042 if (!err) {
1043 nh->fib_nh_dev = fib6_nh.fib_nh_dev;
1044 netdev_hold(nh->fib_nh_dev, &nh->fib_nh_dev_tracker,
1045 GFP_KERNEL);
1046 nh->fib_nh_oif = nh->fib_nh_dev->ifindex;
1047 nh->fib_nh_scope = RT_SCOPE_LINK;
1048
1049 ipv6_stub->fib6_nh_release(&fib6_nh);
1050 }
1051
1052 return err;
1053 }
1054
1055 /*
1056 * Picture
1057 * -------
1058 *
1059 * Semantics of nexthop is very messy by historical reasons.
1060 * We have to take into account, that:
1061 * a) gateway can be actually local interface address,
1062 * so that gatewayed route is direct.
1063 * b) gateway must be on-link address, possibly
1064 * described not by an ifaddr, but also by a direct route.
1065 * c) If both gateway and interface are specified, they should not
1066 * contradict.
1067 * d) If we use tunnel routes, gateway could be not on-link.
1068 *
1069 * Attempt to reconcile all of these (alas, self-contradictory) conditions
1070 * results in pretty ugly and hairy code with obscure logic.
1071 *
1072 * I chose to generalized it instead, so that the size
1073 * of code does not increase practically, but it becomes
1074 * much more general.
1075 * Every prefix is assigned a "scope" value: "host" is local address,
1076 * "link" is direct route,
1077 * [ ... "site" ... "interior" ... ]
1078 * and "universe" is true gateway route with global meaning.
1079 *
1080 * Every prefix refers to a set of "nexthop"s (gw, oif),
1081 * where gw must have narrower scope. This recursion stops
1082 * when gw has LOCAL scope or if "nexthop" is declared ONLINK,
1083 * which means that gw is forced to be on link.
1084 *
1085 * Code is still hairy, but now it is apparently logically
1086 * consistent and very flexible. F.e. as by-product it allows
1087 * to co-exists in peace independent exterior and interior
1088 * routing processes.
1089 *
1090 * Normally it looks as following.
1091 *
1092 * {universe prefix} -> (gw, oif) [scope link]
1093 * |
1094 * |-> {link prefix} -> (gw, oif) [scope local]
1095 * |
1096 * |-> {local prefix} (terminal node)
1097 */
1098 static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table,
1099 u8 scope, struct netlink_ext_ack *extack)
1100 {
1101 struct net_device *dev;
1102 struct fib_result res;
1103 int err = 0;
1104
1105 if (nh->fib_nh_flags & RTNH_F_ONLINK) {
1106 unsigned int addr_type;
1107
1108 if (scope >= RT_SCOPE_LINK) {
1109 NL_SET_ERR_MSG(extack, "Nexthop has invalid scope");
1110 return -EINVAL;
1111 }
1112 dev = __dev_get_by_index(net, nh->fib_nh_oif);
1113 if (!dev) {
1114 NL_SET_ERR_MSG(extack, "Nexthop device required for onlink");
1115 return -ENODEV;
1116 }
1117 if (!(dev->flags & IFF_UP)) {
1118 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
1119 return -ENETDOWN;
1120 }
1121 addr_type = inet_addr_type_dev_table(net, dev, nh->fib_nh_gw4);
1122 if (addr_type != RTN_UNICAST) {
1123 NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway");
1124 return -EINVAL;
1125 }
1126 if (!netif_carrier_ok(dev))
1127 nh->fib_nh_flags |= RTNH_F_LINKDOWN;
1128 nh->fib_nh_dev = dev;
1129 netdev_hold(dev, &nh->fib_nh_dev_tracker, GFP_ATOMIC);
1130 nh->fib_nh_scope = RT_SCOPE_LINK;
1131 return 0;
1132 }
1133 rcu_read_lock();
1134 {
1135 struct fib_table *tbl = NULL;
1136 struct flowi4 fl4 = {
1137 .daddr = nh->fib_nh_gw4,
1138 .flowi4_scope = scope + 1,
1139 .flowi4_oif = nh->fib_nh_oif,
1140 .flowi4_iif = LOOPBACK_IFINDEX,
1141 };
1142
1143 /* It is not necessary, but requires a bit of thinking */
1144 if (fl4.flowi4_scope < RT_SCOPE_LINK)
1145 fl4.flowi4_scope = RT_SCOPE_LINK;
1146
1147 if (table && table != RT_TABLE_MAIN)
1148 tbl = fib_get_table(net, table);
1149
1150 if (tbl)
1151 err = fib_table_lookup(tbl, &fl4, &res,
1152 FIB_LOOKUP_IGNORE_LINKSTATE |
1153 FIB_LOOKUP_NOREF);
1154
1155 /* on error or if no table given do full lookup. This
1156 * is needed for example when nexthops are in the local
1157 * table rather than the given table
1158 */
1159 if (!tbl || err) {
1160 err = fib_lookup(net, &fl4, &res,
1161 FIB_LOOKUP_IGNORE_LINKSTATE);
1162 }
1163
1164 if (err) {
1165 NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway");
1166 goto out;
1167 }
1168 }
1169
1170 err = -EINVAL;
1171 if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) {
1172 NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway");
1173 goto out;
1174 }
1175 nh->fib_nh_scope = res.scope;
1176 nh->fib_nh_oif = FIB_RES_OIF(res);
1177 nh->fib_nh_dev = dev = FIB_RES_DEV(res);
1178 if (!dev) {
1179 NL_SET_ERR_MSG(extack,
1180 "No egress device for nexthop gateway");
1181 goto out;
1182 }
1183 netdev_hold(dev, &nh->fib_nh_dev_tracker, GFP_ATOMIC);
1184 if (!netif_carrier_ok(dev))
1185 nh->fib_nh_flags |= RTNH_F_LINKDOWN;
1186 err = (dev->flags & IFF_UP) ? 0 : -ENETDOWN;
1187 out:
1188 rcu_read_unlock();
1189 return err;
1190 }
1191
1192 static int fib_check_nh_nongw(struct net *net, struct fib_nh *nh,
1193 struct netlink_ext_ack *extack)
1194 {
1195 struct in_device *in_dev;
1196 int err;
1197
1198 if (nh->fib_nh_flags & (RTNH_F_PERVASIVE | RTNH_F_ONLINK)) {
1199 NL_SET_ERR_MSG(extack,
1200 "Invalid flags for nexthop - PERVASIVE and ONLINK can not be set");
1201 return -EINVAL;
1202 }
1203
1204 rcu_read_lock();
1205
1206 err = -ENODEV;
1207 in_dev = inetdev_by_index(net, nh->fib_nh_oif);
1208 if (!in_dev)
1209 goto out;
1210 err = -ENETDOWN;
1211 if (!(in_dev->dev->flags & IFF_UP)) {
1212 NL_SET_ERR_MSG(extack, "Device for nexthop is not up");
1213 goto out;
1214 }
1215
1216 nh->fib_nh_dev = in_dev->dev;
1217 netdev_hold(nh->fib_nh_dev, &nh->fib_nh_dev_tracker, GFP_ATOMIC);
1218 nh->fib_nh_scope = RT_SCOPE_HOST;
1219 if (!netif_carrier_ok(nh->fib_nh_dev))
1220 nh->fib_nh_flags |= RTNH_F_LINKDOWN;
1221 err = 0;
1222 out:
1223 rcu_read_unlock();
1224 return err;
1225 }
1226
1227 int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope,
1228 struct netlink_ext_ack *extack)
1229 {
1230 int err;
1231
1232 if (nh->fib_nh_gw_family == AF_INET)
1233 err = fib_check_nh_v4_gw(net, nh, table, scope, extack);
1234 else if (nh->fib_nh_gw_family == AF_INET6)
1235 err = fib_check_nh_v6_gw(net, nh, table, extack);
1236 else
1237 err = fib_check_nh_nongw(net, nh, extack);
1238
1239 return err;
1240 }
1241
1242 static struct hlist_head *
1243 fib_info_laddrhash_bucket(const struct net *net, __be32 val)
1244 {
1245 u32 slot = hash_32(net_hash_mix(net) ^ (__force u32)val,
1246 fib_info_hash_bits);
1247
1248 return &fib_info_laddrhash[slot];
1249 }
1250
1251 static void fib_info_hash_move(struct hlist_head *new_info_hash,
1252 struct hlist_head *new_laddrhash,
1253 unsigned int new_size)
1254 {
1255 struct hlist_head *old_info_hash, *old_laddrhash;
1256 unsigned int old_size = fib_info_hash_size;
1257 unsigned int i;
1258
1259 ASSERT_RTNL();
1260 old_info_hash = fib_info_hash;
1261 old_laddrhash = fib_info_laddrhash;
1262 fib_info_hash_size = new_size;
1263 fib_info_hash_bits = ilog2(new_size);
1264
1265 for (i = 0; i < old_size; i++) {
1266 struct hlist_head *head = &fib_info_hash[i];
1267 struct hlist_node *n;
1268 struct fib_info *fi;
1269
1270 hlist_for_each_entry_safe(fi, n, head, fib_hash) {
1271 struct hlist_head *dest;
1272 unsigned int new_hash;
1273
1274 new_hash = fib_info_hashfn(fi);
1275 dest = &new_info_hash[new_hash];
1276 hlist_add_head(&fi->fib_hash, dest);
1277 }
1278 }
1279 fib_info_hash = new_info_hash;
1280
1281 fib_info_laddrhash = new_laddrhash;
1282 for (i = 0; i < old_size; i++) {
1283 struct hlist_head *lhead = &old_laddrhash[i];
1284 struct hlist_node *n;
1285 struct fib_info *fi;
1286
1287 hlist_for_each_entry_safe(fi, n, lhead, fib_lhash) {
1288 struct hlist_head *ldest;
1289
1290 ldest = fib_info_laddrhash_bucket(fi->fib_net,
1291 fi->fib_prefsrc);
1292 hlist_add_head(&fi->fib_lhash, ldest);
1293 }
1294 }
1295
1296 kvfree(old_info_hash);
1297 kvfree(old_laddrhash);
1298 }
1299
1300 __be32 fib_info_update_nhc_saddr(struct net *net, struct fib_nh_common *nhc,
1301 unsigned char scope)
1302 {
1303 struct fib_nh *nh;
1304 __be32 saddr;
1305
1306 if (nhc->nhc_family != AF_INET)
1307 return inet_select_addr(nhc->nhc_dev, 0, scope);
1308
1309 nh = container_of(nhc, struct fib_nh, nh_common);
1310 saddr = inet_select_addr(nh->fib_nh_dev, nh->fib_nh_gw4, scope);
1311
1312 WRITE_ONCE(nh->nh_saddr, saddr);
1313 WRITE_ONCE(nh->nh_saddr_genid, atomic_read(&net->ipv4.dev_addr_genid));
1314
1315 return saddr;
1316 }
1317
1318 __be32 fib_result_prefsrc(struct net *net, struct fib_result *res)
1319 {
1320 struct fib_nh_common *nhc = res->nhc;
1321
1322 if (res->fi->fib_prefsrc)
1323 return res->fi->fib_prefsrc;
1324
1325 if (nhc->nhc_family == AF_INET) {
1326 struct fib_nh *nh;
1327
1328 nh = container_of(nhc, struct fib_nh, nh_common);
1329 if (READ_ONCE(nh->nh_saddr_genid) ==
1330 atomic_read(&net->ipv4.dev_addr_genid))
1331 return READ_ONCE(nh->nh_saddr);
1332 }
1333
1334 return fib_info_update_nhc_saddr(net, nhc, res->fi->fib_scope);
1335 }
1336
1337 static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc)
1338 {
1339 if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst ||
1340 fib_prefsrc != cfg->fc_dst) {
1341 u32 tb_id = cfg->fc_table;
1342 int rc;
1343
1344 if (tb_id == RT_TABLE_MAIN)
1345 tb_id = RT_TABLE_LOCAL;
1346
1347 rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net,
1348 fib_prefsrc, tb_id);
1349
1350 if (rc != RTN_LOCAL && tb_id != RT_TABLE_LOCAL) {
1351 rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net,
1352 fib_prefsrc, RT_TABLE_LOCAL);
1353 }
1354
1355 if (rc != RTN_LOCAL)
1356 return false;
1357 }
1358 return true;
1359 }
1360
1361 struct fib_info *fib_create_info(struct fib_config *cfg,
1362 struct netlink_ext_ack *extack)
1363 {
1364 int err;
1365 struct fib_info *fi = NULL;
1366 struct nexthop *nh = NULL;
1367 struct fib_info *ofi;
1368 int nhs = 1;
1369 struct net *net = cfg->fc_nlinfo.nl_net;
1370
1371 ASSERT_RTNL();
1372 if (cfg->fc_type > RTN_MAX)
1373 goto err_inval;
1374
1375 /* Fast check to catch the most weird cases */
1376 if (fib_props[cfg->fc_type].scope > cfg->fc_scope) {
1377 NL_SET_ERR_MSG(extack, "Invalid scope");
1378 goto err_inval;
1379 }
1380
1381 if (cfg->fc_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) {
1382 NL_SET_ERR_MSG(extack,
1383 "Invalid rtm_flags - can not contain DEAD or LINKDOWN");
1384 goto err_inval;
1385 }
1386
1387 if (cfg->fc_nh_id) {
1388 if (!cfg->fc_mx) {
1389 fi = fib_find_info_nh(net, cfg);
1390 if (fi) {
1391 refcount_inc(&fi->fib_treeref);
1392 return fi;
1393 }
1394 }
1395
1396 nh = nexthop_find_by_id(net, cfg->fc_nh_id);
1397 if (!nh) {
1398 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
1399 goto err_inval;
1400 }
1401 nhs = 0;
1402 }
1403
1404 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1405 if (cfg->fc_mp) {
1406 nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len, extack);
1407 if (nhs == 0)
1408 goto err_inval;
1409 }
1410 #endif
1411
1412 err = -ENOBUFS;
1413
1414 if (fib_info_cnt >= fib_info_hash_size) {
1415 unsigned int new_size = fib_info_hash_size << 1;
1416 struct hlist_head *new_info_hash;
1417 struct hlist_head *new_laddrhash;
1418 size_t bytes;
1419
1420 if (!new_size)
1421 new_size = 16;
1422 bytes = (size_t)new_size * sizeof(struct hlist_head *);
1423 new_info_hash = kvzalloc(bytes, GFP_KERNEL);
1424 new_laddrhash = kvzalloc(bytes, GFP_KERNEL);
1425 if (!new_info_hash || !new_laddrhash) {
1426 kvfree(new_info_hash);
1427 kvfree(new_laddrhash);
1428 } else {
1429 fib_info_hash_move(new_info_hash, new_laddrhash, new_size);
1430 }
1431 if (!fib_info_hash_size)
1432 goto failure;
1433 }
1434
1435 fi = kzalloc(struct_size(fi, fib_nh, nhs), GFP_KERNEL);
1436 if (!fi)
1437 goto failure;
1438 fi->fib_metrics = ip_fib_metrics_init(cfg->fc_mx, cfg->fc_mx_len, extack);
1439 if (IS_ERR(fi->fib_metrics)) {
1440 err = PTR_ERR(fi->fib_metrics);
1441 kfree(fi);
1442 return ERR_PTR(err);
1443 }
1444
1445 fi->fib_net = net;
1446 fi->fib_protocol = cfg->fc_protocol;
1447 fi->fib_scope = cfg->fc_scope;
1448 fi->fib_flags = cfg->fc_flags;
1449 fi->fib_priority = cfg->fc_priority;
1450 fi->fib_prefsrc = cfg->fc_prefsrc;
1451 fi->fib_type = cfg->fc_type;
1452 fi->fib_tb_id = cfg->fc_table;
1453
1454 fi->fib_nhs = nhs;
1455 if (nh) {
1456 if (!nexthop_get(nh)) {
1457 NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
1458 err = -EINVAL;
1459 } else {
1460 err = 0;
1461 fi->nh = nh;
1462 }
1463 } else {
1464 change_nexthops(fi) {
1465 nexthop_nh->nh_parent = fi;
1466 } endfor_nexthops(fi)
1467
1468 if (cfg->fc_mp)
1469 err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg,
1470 extack);
1471 else
1472 err = fib_nh_init(net, fi->fib_nh, cfg, 1, extack);
1473 }
1474
1475 if (err != 0)
1476 goto failure;
1477
1478 if (fib_props[cfg->fc_type].error) {
1479 if (cfg->fc_gw_family || cfg->fc_oif || cfg->fc_mp) {
1480 NL_SET_ERR_MSG(extack,
1481 "Gateway, device and multipath can not be specified for this route type");
1482 goto err_inval;
1483 }
1484 goto link_it;
1485 } else {
1486 switch (cfg->fc_type) {
1487 case RTN_UNICAST:
1488 case RTN_LOCAL:
1489 case RTN_BROADCAST:
1490 case RTN_ANYCAST:
1491 case RTN_MULTICAST:
1492 break;
1493 default:
1494 NL_SET_ERR_MSG(extack, "Invalid route type");
1495 goto err_inval;
1496 }
1497 }
1498
1499 if (cfg->fc_scope > RT_SCOPE_HOST) {
1500 NL_SET_ERR_MSG(extack, "Invalid scope");
1501 goto err_inval;
1502 }
1503
1504 if (fi->nh) {
1505 err = fib_check_nexthop(fi->nh, cfg->fc_scope, extack);
1506 if (err)
1507 goto failure;
1508 } else if (cfg->fc_scope == RT_SCOPE_HOST) {
1509 struct fib_nh *nh = fi->fib_nh;
1510
1511 /* Local address is added. */
1512 if (nhs != 1) {
1513 NL_SET_ERR_MSG(extack,
1514 "Route with host scope can not have multiple nexthops");
1515 goto err_inval;
1516 }
1517 if (nh->fib_nh_gw_family) {
1518 NL_SET_ERR_MSG(extack,
1519 "Route with host scope can not have a gateway");
1520 goto err_inval;
1521 }
1522 nh->fib_nh_scope = RT_SCOPE_NOWHERE;
1523 nh->fib_nh_dev = dev_get_by_index(net, nh->fib_nh_oif);
1524 err = -ENODEV;
1525 if (!nh->fib_nh_dev)
1526 goto failure;
1527 netdev_tracker_alloc(nh->fib_nh_dev, &nh->fib_nh_dev_tracker,
1528 GFP_KERNEL);
1529 } else {
1530 int linkdown = 0;
1531
1532 change_nexthops(fi) {
1533 err = fib_check_nh(cfg->fc_nlinfo.nl_net, nexthop_nh,
1534 cfg->fc_table, cfg->fc_scope,
1535 extack);
1536 if (err != 0)
1537 goto failure;
1538 if (nexthop_nh->fib_nh_flags & RTNH_F_LINKDOWN)
1539 linkdown++;
1540 } endfor_nexthops(fi)
1541 if (linkdown == fi->fib_nhs)
1542 fi->fib_flags |= RTNH_F_LINKDOWN;
1543 }
1544
1545 if (fi->fib_prefsrc && !fib_valid_prefsrc(cfg, fi->fib_prefsrc)) {
1546 NL_SET_ERR_MSG(extack, "Invalid prefsrc address");
1547 goto err_inval;
1548 }
1549
1550 if (!fi->nh) {
1551 change_nexthops(fi) {
1552 fib_info_update_nhc_saddr(net, &nexthop_nh->nh_common,
1553 fi->fib_scope);
1554 if (nexthop_nh->fib_nh_gw_family == AF_INET6)
1555 fi->fib_nh_is_v6 = true;
1556 } endfor_nexthops(fi)
1557
1558 fib_rebalance(fi);
1559 }
1560
1561 link_it:
1562 ofi = fib_find_info(fi);
1563 if (ofi) {
1564 /* fib_table_lookup() should not see @fi yet. */
1565 fi->fib_dead = 1;
1566 free_fib_info(fi);
1567 refcount_inc(&ofi->fib_treeref);
1568 return ofi;
1569 }
1570
1571 refcount_set(&fi->fib_treeref, 1);
1572 refcount_set(&fi->fib_clntref, 1);
1573
1574 fib_info_cnt++;
1575 hlist_add_head(&fi->fib_hash,
1576 &fib_info_hash[fib_info_hashfn(fi)]);
1577 if (fi->fib_prefsrc) {
1578 struct hlist_head *head;
1579
1580 head = fib_info_laddrhash_bucket(net, fi->fib_prefsrc);
1581 hlist_add_head(&fi->fib_lhash, head);
1582 }
1583 if (fi->nh) {
1584 list_add(&fi->nh_list, &nh->fi_list);
1585 } else {
1586 change_nexthops(fi) {
1587 struct hlist_head *head;
1588
1589 if (!nexthop_nh->fib_nh_dev)
1590 continue;
1591 head = fib_nh_head(nexthop_nh->fib_nh_dev);
1592 hlist_add_head_rcu(&nexthop_nh->nh_hash, head);
1593 } endfor_nexthops(fi)
1594 }
1595 return fi;
1596
1597 err_inval:
1598 err = -EINVAL;
1599
1600 failure:
1601 if (fi) {
1602 /* fib_table_lookup() should not see @fi yet. */
1603 fi->fib_dead = 1;
1604 free_fib_info(fi);
1605 }
1606
1607 return ERR_PTR(err);
1608 }
1609
1610 int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc,
1611 u8 rt_family, unsigned char *flags, bool skip_oif)
1612 {
1613 if (nhc->nhc_flags & RTNH_F_DEAD)
1614 *flags |= RTNH_F_DEAD;
1615
1616 if (nhc->nhc_flags & RTNH_F_LINKDOWN) {
1617 *flags |= RTNH_F_LINKDOWN;
1618
1619 rcu_read_lock();
1620 switch (nhc->nhc_family) {
1621 case AF_INET:
1622 if (ip_ignore_linkdown(nhc->nhc_dev))
1623 *flags |= RTNH_F_DEAD;
1624 break;
1625 case AF_INET6:
1626 if (ip6_ignore_linkdown(nhc->nhc_dev))
1627 *flags |= RTNH_F_DEAD;
1628 break;
1629 }
1630 rcu_read_unlock();
1631 }
1632
1633 switch (nhc->nhc_gw_family) {
1634 case AF_INET:
1635 if (nla_put_in_addr(skb, RTA_GATEWAY, nhc->nhc_gw.ipv4))
1636 goto nla_put_failure;
1637 break;
1638 case AF_INET6:
1639 /* if gateway family does not match nexthop family
1640 * gateway is encoded as RTA_VIA
1641 */
1642 if (rt_family != nhc->nhc_gw_family) {
1643 int alen = sizeof(struct in6_addr);
1644 struct nlattr *nla;
1645 struct rtvia *via;
1646
1647 nla = nla_reserve(skb, RTA_VIA, alen + 2);
1648 if (!nla)
1649 goto nla_put_failure;
1650
1651 via = nla_data(nla);
1652 via->rtvia_family = AF_INET6;
1653 memcpy(via->rtvia_addr, &nhc->nhc_gw.ipv6, alen);
1654 } else if (nla_put_in6_addr(skb, RTA_GATEWAY,
1655 &nhc->nhc_gw.ipv6) < 0) {
1656 goto nla_put_failure;
1657 }
1658 break;
1659 }
1660
1661 *flags |= (nhc->nhc_flags &
1662 (RTNH_F_ONLINK | RTNH_F_OFFLOAD | RTNH_F_TRAP));
1663
1664 if (!skip_oif && nhc->nhc_dev &&
1665 nla_put_u32(skb, RTA_OIF, nhc->nhc_dev->ifindex))
1666 goto nla_put_failure;
1667
1668 if (nhc->nhc_lwtstate &&
1669 lwtunnel_fill_encap(skb, nhc->nhc_lwtstate,
1670 RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
1671 goto nla_put_failure;
1672
1673 return 0;
1674
1675 nla_put_failure:
1676 return -EMSGSIZE;
1677 }
1678 EXPORT_SYMBOL_GPL(fib_nexthop_info);
1679
1680 #if IS_ENABLED(CONFIG_IP_ROUTE_MULTIPATH) || IS_ENABLED(CONFIG_IPV6)
1681 int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc,
1682 int nh_weight, u8 rt_family, u32 nh_tclassid)
1683 {
1684 const struct net_device *dev = nhc->nhc_dev;
1685 struct rtnexthop *rtnh;
1686 unsigned char flags = 0;
1687
1688 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
1689 if (!rtnh)
1690 goto nla_put_failure;
1691
1692 rtnh->rtnh_hops = nh_weight - 1;
1693 rtnh->rtnh_ifindex = dev ? dev->ifindex : 0;
1694
1695 if (fib_nexthop_info(skb, nhc, rt_family, &flags, true) < 0)
1696 goto nla_put_failure;
1697
1698 rtnh->rtnh_flags = flags;
1699
1700 if (nh_tclassid && nla_put_u32(skb, RTA_FLOW, nh_tclassid))
1701 goto nla_put_failure;
1702
1703 /* length of rtnetlink header + attributes */
1704 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
1705
1706 return 0;
1707
1708 nla_put_failure:
1709 return -EMSGSIZE;
1710 }
1711 EXPORT_SYMBOL_GPL(fib_add_nexthop);
1712 #endif
1713
1714 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1715 static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
1716 {
1717 struct nlattr *mp;
1718
1719 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
1720 if (!mp)
1721 goto nla_put_failure;
1722
1723 if (unlikely(fi->nh)) {
1724 if (nexthop_mpath_fill_node(skb, fi->nh, AF_INET) < 0)
1725 goto nla_put_failure;
1726 goto mp_end;
1727 }
1728
1729 for_nexthops(fi) {
1730 u32 nh_tclassid = 0;
1731 #ifdef CONFIG_IP_ROUTE_CLASSID
1732 nh_tclassid = nh->nh_tclassid;
1733 #endif
1734 if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight,
1735 AF_INET, nh_tclassid) < 0)
1736 goto nla_put_failure;
1737 } endfor_nexthops(fi);
1738
1739 mp_end:
1740 nla_nest_end(skb, mp);
1741
1742 return 0;
1743
1744 nla_put_failure:
1745 return -EMSGSIZE;
1746 }
1747 #else
1748 static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
1749 {
1750 return 0;
1751 }
1752 #endif
1753
1754 int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
1755 const struct fib_rt_info *fri, unsigned int flags)
1756 {
1757 unsigned int nhs = fib_info_num_path(fri->fi);
1758 struct fib_info *fi = fri->fi;
1759 u32 tb_id = fri->tb_id;
1760 struct nlmsghdr *nlh;
1761 struct rtmsg *rtm;
1762
1763 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
1764 if (!nlh)
1765 return -EMSGSIZE;
1766
1767 rtm = nlmsg_data(nlh);
1768 rtm->rtm_family = AF_INET;
1769 rtm->rtm_dst_len = fri->dst_len;
1770 rtm->rtm_src_len = 0;
1771 rtm->rtm_tos = inet_dscp_to_dsfield(fri->dscp);
1772 if (tb_id < 256)
1773 rtm->rtm_table = tb_id;
1774 else
1775 rtm->rtm_table = RT_TABLE_COMPAT;
1776 if (nla_put_u32(skb, RTA_TABLE, tb_id))
1777 goto nla_put_failure;
1778 rtm->rtm_type = fri->type;
1779 rtm->rtm_flags = fi->fib_flags;
1780 rtm->rtm_scope = fi->fib_scope;
1781 rtm->rtm_protocol = fi->fib_protocol;
1782
1783 if (rtm->rtm_dst_len &&
1784 nla_put_in_addr(skb, RTA_DST, fri->dst))
1785 goto nla_put_failure;
1786 if (fi->fib_priority &&
1787 nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority))
1788 goto nla_put_failure;
1789 if (rtnetlink_put_metrics(skb, fi->fib_metrics->metrics) < 0)
1790 goto nla_put_failure;
1791
1792 if (fi->fib_prefsrc &&
1793 nla_put_in_addr(skb, RTA_PREFSRC, fi->fib_prefsrc))
1794 goto nla_put_failure;
1795
1796 if (fi->nh) {
1797 if (nla_put_u32(skb, RTA_NH_ID, fi->nh->id))
1798 goto nla_put_failure;
1799 if (nexthop_is_blackhole(fi->nh))
1800 rtm->rtm_type = RTN_BLACKHOLE;
1801 if (!READ_ONCE(fi->fib_net->ipv4.sysctl_nexthop_compat_mode))
1802 goto offload;
1803 }
1804
1805 if (nhs == 1) {
1806 const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
1807 unsigned char flags = 0;
1808
1809 if (fib_nexthop_info(skb, nhc, AF_INET, &flags, false) < 0)
1810 goto nla_put_failure;
1811
1812 rtm->rtm_flags = flags;
1813 #ifdef CONFIG_IP_ROUTE_CLASSID
1814 if (nhc->nhc_family == AF_INET) {
1815 struct fib_nh *nh;
1816
1817 nh = container_of(nhc, struct fib_nh, nh_common);
1818 if (nh->nh_tclassid &&
1819 nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
1820 goto nla_put_failure;
1821 }
1822 #endif
1823 } else {
1824 if (fib_add_multipath(skb, fi) < 0)
1825 goto nla_put_failure;
1826 }
1827
1828 offload:
1829 if (fri->offload)
1830 rtm->rtm_flags |= RTM_F_OFFLOAD;
1831 if (fri->trap)
1832 rtm->rtm_flags |= RTM_F_TRAP;
1833 if (fri->offload_failed)
1834 rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED;
1835
1836 nlmsg_end(skb, nlh);
1837 return 0;
1838
1839 nla_put_failure:
1840 nlmsg_cancel(skb, nlh);
1841 return -EMSGSIZE;
1842 }
1843
1844 /*
1845 * Update FIB if:
1846 * - local address disappeared -> we must delete all the entries
1847 * referring to it.
1848 * - device went down -> we must shutdown all nexthops going via it.
1849 */
1850 int fib_sync_down_addr(struct net_device *dev, __be32 local)
1851 {
1852 int tb_id = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN;
1853 struct net *net = dev_net(dev);
1854 struct hlist_head *head;
1855 struct fib_info *fi;
1856 int ret = 0;
1857
1858 if (!fib_info_laddrhash || local == 0)
1859 return 0;
1860
1861 head = fib_info_laddrhash_bucket(net, local);
1862 hlist_for_each_entry(fi, head, fib_lhash) {
1863 if (!net_eq(fi->fib_net, net) ||
1864 fi->fib_tb_id != tb_id)
1865 continue;
1866 if (fi->fib_prefsrc == local) {
1867 fi->fib_flags |= RTNH_F_DEAD;
1868 fi->pfsrc_removed = true;
1869 ret++;
1870 }
1871 }
1872 return ret;
1873 }
1874
1875 static int call_fib_nh_notifiers(struct fib_nh *nh,
1876 enum fib_event_type event_type)
1877 {
1878 bool ignore_link_down = ip_ignore_linkdown(nh->fib_nh_dev);
1879 struct fib_nh_notifier_info info = {
1880 .fib_nh = nh,
1881 };
1882
1883 switch (event_type) {
1884 case FIB_EVENT_NH_ADD:
1885 if (nh->fib_nh_flags & RTNH_F_DEAD)
1886 break;
1887 if (ignore_link_down && nh->fib_nh_flags & RTNH_F_LINKDOWN)
1888 break;
1889 return call_fib4_notifiers(dev_net(nh->fib_nh_dev), event_type,
1890 &info.info);
1891 case FIB_EVENT_NH_DEL:
1892 if ((ignore_link_down && nh->fib_nh_flags & RTNH_F_LINKDOWN) ||
1893 (nh->fib_nh_flags & RTNH_F_DEAD))
1894 return call_fib4_notifiers(dev_net(nh->fib_nh_dev),
1895 event_type, &info.info);
1896 break;
1897 default:
1898 break;
1899 }
1900
1901 return NOTIFY_DONE;
1902 }
1903
1904 /* Update the PMTU of exceptions when:
1905 * - the new MTU of the first hop becomes smaller than the PMTU
1906 * - the old MTU was the same as the PMTU, and it limited discovery of
1907 * larger MTUs on the path. With that limit raised, we can now
1908 * discover larger MTUs
1909 * A special case is locked exceptions, for which the PMTU is smaller
1910 * than the minimal accepted PMTU:
1911 * - if the new MTU is greater than the PMTU, don't make any change
1912 * - otherwise, unlock and set PMTU
1913 */
1914 void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig)
1915 {
1916 struct fnhe_hash_bucket *bucket;
1917 int i;
1918
1919 bucket = rcu_dereference_protected(nhc->nhc_exceptions, 1);
1920 if (!bucket)
1921 return;
1922
1923 for (i = 0; i < FNHE_HASH_SIZE; i++) {
1924 struct fib_nh_exception *fnhe;
1925
1926 for (fnhe = rcu_dereference_protected(bucket[i].chain, 1);
1927 fnhe;
1928 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1)) {
1929 if (fnhe->fnhe_mtu_locked) {
1930 if (new <= fnhe->fnhe_pmtu) {
1931 fnhe->fnhe_pmtu = new;
1932 fnhe->fnhe_mtu_locked = false;
1933 }
1934 } else if (new < fnhe->fnhe_pmtu ||
1935 orig == fnhe->fnhe_pmtu) {
1936 fnhe->fnhe_pmtu = new;
1937 }
1938 }
1939 }
1940 }
1941
1942 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu)
1943 {
1944 struct hlist_head *head = fib_nh_head(dev);
1945 struct fib_nh *nh;
1946
1947 hlist_for_each_entry(nh, head, nh_hash) {
1948 DEBUG_NET_WARN_ON_ONCE(nh->fib_nh_dev != dev);
1949 fib_nhc_update_mtu(&nh->nh_common, dev->mtu, orig_mtu);
1950 }
1951 }
1952
1953 /* Event force Flags Description
1954 * NETDEV_CHANGE 0 LINKDOWN Carrier OFF, not for scope host
1955 * NETDEV_DOWN 0 LINKDOWN|DEAD Link down, not for scope host
1956 * NETDEV_DOWN 1 LINKDOWN|DEAD Last address removed
1957 * NETDEV_UNREGISTER 1 LINKDOWN|DEAD Device removed
1958 *
1959 * only used when fib_nh is built into fib_info
1960 */
1961 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force)
1962 {
1963 struct hlist_head *head = fib_nh_head(dev);
1964 struct fib_info *prev_fi = NULL;
1965 int scope = RT_SCOPE_NOWHERE;
1966 struct fib_nh *nh;
1967 int ret = 0;
1968
1969 if (force)
1970 scope = -1;
1971
1972 hlist_for_each_entry(nh, head, nh_hash) {
1973 struct fib_info *fi = nh->nh_parent;
1974 int dead;
1975
1976 BUG_ON(!fi->fib_nhs);
1977 DEBUG_NET_WARN_ON_ONCE(nh->fib_nh_dev != dev);
1978 if (fi == prev_fi)
1979 continue;
1980 prev_fi = fi;
1981 dead = 0;
1982 change_nexthops(fi) {
1983 if (nexthop_nh->fib_nh_flags & RTNH_F_DEAD)
1984 dead++;
1985 else if (nexthop_nh->fib_nh_dev == dev &&
1986 nexthop_nh->fib_nh_scope != scope) {
1987 switch (event) {
1988 case NETDEV_DOWN:
1989 case NETDEV_UNREGISTER:
1990 nexthop_nh->fib_nh_flags |= RTNH_F_DEAD;
1991 fallthrough;
1992 case NETDEV_CHANGE:
1993 nexthop_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
1994 break;
1995 }
1996 call_fib_nh_notifiers(nexthop_nh,
1997 FIB_EVENT_NH_DEL);
1998 dead++;
1999 }
2000 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2001 if (event == NETDEV_UNREGISTER &&
2002 nexthop_nh->fib_nh_dev == dev) {
2003 dead = fi->fib_nhs;
2004 break;
2005 }
2006 #endif
2007 } endfor_nexthops(fi)
2008 if (dead == fi->fib_nhs) {
2009 switch (event) {
2010 case NETDEV_DOWN:
2011 case NETDEV_UNREGISTER:
2012 fi->fib_flags |= RTNH_F_DEAD;
2013 fallthrough;
2014 case NETDEV_CHANGE:
2015 fi->fib_flags |= RTNH_F_LINKDOWN;
2016 break;
2017 }
2018 ret++;
2019 }
2020
2021 fib_rebalance(fi);
2022 }
2023
2024 return ret;
2025 }
2026
2027 /* Must be invoked inside of an RCU protected region. */
2028 static void fib_select_default(const struct flowi4 *flp, struct fib_result *res)
2029 {
2030 struct fib_info *fi = NULL, *last_resort = NULL;
2031 struct hlist_head *fa_head = res->fa_head;
2032 struct fib_table *tb = res->table;
2033 u8 slen = 32 - res->prefixlen;
2034 int order = -1, last_idx = -1;
2035 struct fib_alias *fa, *fa1 = NULL;
2036 u32 last_prio = res->fi->fib_priority;
2037 dscp_t last_dscp = 0;
2038
2039 hlist_for_each_entry_rcu(fa, fa_head, fa_list) {
2040 struct fib_info *next_fi = fa->fa_info;
2041 struct fib_nh_common *nhc;
2042
2043 if (fa->fa_slen != slen)
2044 continue;
2045 if (fa->fa_dscp && !fib_dscp_masked_match(fa->fa_dscp, flp))
2046 continue;
2047 if (fa->tb_id != tb->tb_id)
2048 continue;
2049 if (next_fi->fib_priority > last_prio &&
2050 fa->fa_dscp == last_dscp) {
2051 if (last_dscp)
2052 continue;
2053 break;
2054 }
2055 if (next_fi->fib_flags & RTNH_F_DEAD)
2056 continue;
2057 last_dscp = fa->fa_dscp;
2058 last_prio = next_fi->fib_priority;
2059
2060 if (next_fi->fib_scope != res->scope ||
2061 fa->fa_type != RTN_UNICAST)
2062 continue;
2063
2064 nhc = fib_info_nhc(next_fi, 0);
2065 if (!nhc->nhc_gw_family || nhc->nhc_scope != RT_SCOPE_LINK)
2066 continue;
2067
2068 fib_alias_accessed(fa);
2069
2070 if (!fi) {
2071 if (next_fi != res->fi)
2072 break;
2073 fa1 = fa;
2074 } else if (!fib_detect_death(fi, order, &last_resort,
2075 &last_idx, fa1->fa_default)) {
2076 fib_result_assign(res, fi);
2077 fa1->fa_default = order;
2078 goto out;
2079 }
2080 fi = next_fi;
2081 order++;
2082 }
2083
2084 if (order <= 0 || !fi) {
2085 if (fa1)
2086 fa1->fa_default = -1;
2087 goto out;
2088 }
2089
2090 if (!fib_detect_death(fi, order, &last_resort, &last_idx,
2091 fa1->fa_default)) {
2092 fib_result_assign(res, fi);
2093 fa1->fa_default = order;
2094 goto out;
2095 }
2096
2097 if (last_idx >= 0)
2098 fib_result_assign(res, last_resort);
2099 fa1->fa_default = last_idx;
2100 out:
2101 return;
2102 }
2103
2104 /*
2105 * Dead device goes up. We wake up dead nexthops.
2106 * It takes sense only on multipath routes.
2107 *
2108 * only used when fib_nh is built into fib_info
2109 */
2110 int fib_sync_up(struct net_device *dev, unsigned char nh_flags)
2111 {
2112 struct fib_info *prev_fi;
2113 struct hlist_head *head;
2114 struct fib_nh *nh;
2115 int ret;
2116
2117 if (!(dev->flags & IFF_UP))
2118 return 0;
2119
2120 if (nh_flags & RTNH_F_DEAD) {
2121 unsigned int flags = dev_get_flags(dev);
2122
2123 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
2124 nh_flags |= RTNH_F_LINKDOWN;
2125 }
2126
2127 prev_fi = NULL;
2128 head = fib_nh_head(dev);
2129 ret = 0;
2130
2131 hlist_for_each_entry(nh, head, nh_hash) {
2132 struct fib_info *fi = nh->nh_parent;
2133 int alive;
2134
2135 BUG_ON(!fi->fib_nhs);
2136 DEBUG_NET_WARN_ON_ONCE(nh->fib_nh_dev != dev);
2137 if (fi == prev_fi)
2138 continue;
2139
2140 prev_fi = fi;
2141 alive = 0;
2142 change_nexthops(fi) {
2143 if (!(nexthop_nh->fib_nh_flags & nh_flags)) {
2144 alive++;
2145 continue;
2146 }
2147 if (!nexthop_nh->fib_nh_dev ||
2148 !(nexthop_nh->fib_nh_dev->flags & IFF_UP))
2149 continue;
2150 if (nexthop_nh->fib_nh_dev != dev ||
2151 !__in_dev_get_rtnl(dev))
2152 continue;
2153 alive++;
2154 nexthop_nh->fib_nh_flags &= ~nh_flags;
2155 call_fib_nh_notifiers(nexthop_nh, FIB_EVENT_NH_ADD);
2156 } endfor_nexthops(fi)
2157
2158 if (alive > 0) {
2159 fi->fib_flags &= ~nh_flags;
2160 ret++;
2161 }
2162
2163 fib_rebalance(fi);
2164 }
2165
2166 return ret;
2167 }
2168
2169 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2170 static bool fib_good_nh(const struct fib_nh *nh)
2171 {
2172 int state = NUD_REACHABLE;
2173
2174 if (nh->fib_nh_scope == RT_SCOPE_LINK) {
2175 struct neighbour *n;
2176
2177 rcu_read_lock();
2178
2179 if (likely(nh->fib_nh_gw_family == AF_INET))
2180 n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev,
2181 (__force u32)nh->fib_nh_gw4);
2182 else if (nh->fib_nh_gw_family == AF_INET6)
2183 n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev,
2184 &nh->fib_nh_gw6);
2185 else
2186 n = NULL;
2187 if (n)
2188 state = READ_ONCE(n->nud_state);
2189
2190 rcu_read_unlock();
2191 }
2192
2193 return !!(state & NUD_VALID);
2194 }
2195
2196 void fib_select_multipath(struct fib_result *res, int hash)
2197 {
2198 struct fib_info *fi = res->fi;
2199 struct net *net = fi->fib_net;
2200 bool first = false;
2201
2202 if (unlikely(res->fi->nh)) {
2203 nexthop_path_fib_result(res, hash);
2204 return;
2205 }
2206
2207 change_nexthops(fi) {
2208 if (READ_ONCE(net->ipv4.sysctl_fib_multipath_use_neigh)) {
2209 if (!fib_good_nh(nexthop_nh))
2210 continue;
2211 if (!first) {
2212 res->nh_sel = nhsel;
2213 res->nhc = &nexthop_nh->nh_common;
2214 first = true;
2215 }
2216 }
2217
2218 if (hash > atomic_read(&nexthop_nh->fib_nh_upper_bound))
2219 continue;
2220
2221 res->nh_sel = nhsel;
2222 res->nhc = &nexthop_nh->nh_common;
2223 return;
2224 } endfor_nexthops(fi);
2225 }
2226 #endif
2227
2228 void fib_select_path(struct net *net, struct fib_result *res,
2229 struct flowi4 *fl4, const struct sk_buff *skb)
2230 {
2231 if (fl4->flowi4_oif)
2232 goto check_saddr;
2233
2234 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2235 if (fib_info_num_path(res->fi) > 1) {
2236 int h = fib_multipath_hash(net, fl4, skb, NULL);
2237
2238 fib_select_multipath(res, h);
2239 }
2240 else
2241 #endif
2242 if (!res->prefixlen &&
2243 res->table->tb_num_default > 1 &&
2244 res->type == RTN_UNICAST)
2245 fib_select_default(fl4, res);
2246
2247 check_saddr:
2248 if (!fl4->saddr) {
2249 struct net_device *l3mdev;
2250
2251 l3mdev = dev_get_by_index_rcu(net, fl4->flowi4_l3mdev);
2252
2253 if (!l3mdev ||
2254 l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) == l3mdev)
2255 fl4->saddr = fib_result_prefsrc(net, res);
2256 else
2257 fl4->saddr = inet_select_addr(l3mdev, 0, RT_SCOPE_LINK);
2258 }
2259 }
Kernel DRM miscellaneous fixes and cross-tree changes