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 DEFINE_SPINLOCK(fib_info_lock); |
54 | static struct hlist_head *fib_info_hash; |
55 | static struct hlist_head *fib_info_laddrhash; |
56 | static unsigned int fib_info_hash_size; |
57 | static unsigned int fib_info_hash_bits; |
58 | static unsigned int fib_info_cnt; |
59 | |
60 | #define DEVINDEX_HASHBITS 8 |
61 | #define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS) |
62 | static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE]; |
63 | |
64 | /* for_nexthops and change_nexthops only used when nexthop object |
65 | * is not set in a fib_info. The logic within can reference fib_nh. |
66 | */ |
67 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
68 | |
69 | #define for_nexthops(fi) { \ |
70 | int nhsel; const struct fib_nh *nh; \ |
71 | for (nhsel = 0, nh = (fi)->fib_nh; \ |
72 | nhsel < fib_info_num_path((fi)); \ |
73 | nh++, nhsel++) |
74 | |
75 | #define change_nexthops(fi) { \ |
76 | int nhsel; struct fib_nh *nexthop_nh; \ |
77 | for (nhsel = 0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \ |
78 | nhsel < fib_info_num_path((fi)); \ |
79 | nexthop_nh++, nhsel++) |
80 | |
81 | #else /* CONFIG_IP_ROUTE_MULTIPATH */ |
82 | |
83 | /* Hope, that gcc will optimize it to get rid of dummy loop */ |
84 | |
85 | #define for_nexthops(fi) { \ |
86 | int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \ |
87 | for (nhsel = 0; nhsel < 1; nhsel++) |
88 | |
89 | #define change_nexthops(fi) { \ |
90 | int nhsel; \ |
91 | struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \ |
92 | for (nhsel = 0; nhsel < 1; nhsel++) |
93 | |
94 | #endif /* CONFIG_IP_ROUTE_MULTIPATH */ |
95 | |
96 | #define endfor_nexthops(fi) } |
97 | |
98 | |
99 | const struct fib_prop fib_props[RTN_MAX + 1] = { |
100 | [RTN_UNSPEC] = { |
101 | .error = 0, |
102 | .scope = RT_SCOPE_NOWHERE, |
103 | }, |
104 | [RTN_UNICAST] = { |
105 | .error = 0, |
106 | .scope = RT_SCOPE_UNIVERSE, |
107 | }, |
108 | [RTN_LOCAL] = { |
109 | .error = 0, |
110 | .scope = RT_SCOPE_HOST, |
111 | }, |
112 | [RTN_BROADCAST] = { |
113 | .error = 0, |
114 | .scope = RT_SCOPE_LINK, |
115 | }, |
116 | [RTN_ANYCAST] = { |
117 | .error = 0, |
118 | .scope = RT_SCOPE_LINK, |
119 | }, |
120 | [RTN_MULTICAST] = { |
121 | .error = 0, |
122 | .scope = RT_SCOPE_UNIVERSE, |
123 | }, |
124 | [RTN_BLACKHOLE] = { |
125 | .error = -EINVAL, |
126 | .scope = RT_SCOPE_UNIVERSE, |
127 | }, |
128 | [RTN_UNREACHABLE] = { |
129 | .error = -EHOSTUNREACH, |
130 | .scope = RT_SCOPE_UNIVERSE, |
131 | }, |
132 | [RTN_PROHIBIT] = { |
133 | .error = -EACCES, |
134 | .scope = RT_SCOPE_UNIVERSE, |
135 | }, |
136 | [RTN_THROW] = { |
137 | .error = -EAGAIN, |
138 | .scope = RT_SCOPE_UNIVERSE, |
139 | }, |
140 | [RTN_NAT] = { |
141 | .error = -EINVAL, |
142 | .scope = RT_SCOPE_NOWHERE, |
143 | }, |
144 | [RTN_XRESOLVE] = { |
145 | .error = -EINVAL, |
146 | .scope = RT_SCOPE_NOWHERE, |
147 | }, |
148 | }; |
149 | |
150 | static void rt_fibinfo_free(struct rtable __rcu **rtp) |
151 | { |
152 | struct rtable *rt = rcu_dereference_protected(*rtp, 1); |
153 | |
154 | if (!rt) |
155 | return; |
156 | |
157 | /* Not even needed : RCU_INIT_POINTER(*rtp, NULL); |
158 | * because we waited an RCU grace period before calling |
159 | * free_fib_info_rcu() |
160 | */ |
161 | |
162 | dst_dev_put(dst: &rt->dst); |
163 | dst_release_immediate(dst: &rt->dst); |
164 | } |
165 | |
166 | static void free_nh_exceptions(struct fib_nh_common *nhc) |
167 | { |
168 | struct fnhe_hash_bucket *hash; |
169 | int i; |
170 | |
171 | hash = rcu_dereference_protected(nhc->nhc_exceptions, 1); |
172 | if (!hash) |
173 | return; |
174 | for (i = 0; i < FNHE_HASH_SIZE; i++) { |
175 | struct fib_nh_exception *fnhe; |
176 | |
177 | fnhe = rcu_dereference_protected(hash[i].chain, 1); |
178 | while (fnhe) { |
179 | struct fib_nh_exception *next; |
180 | |
181 | next = rcu_dereference_protected(fnhe->fnhe_next, 1); |
182 | |
183 | rt_fibinfo_free(rtp: &fnhe->fnhe_rth_input); |
184 | rt_fibinfo_free(rtp: &fnhe->fnhe_rth_output); |
185 | |
186 | kfree(objp: fnhe); |
187 | |
188 | fnhe = next; |
189 | } |
190 | } |
191 | kfree(objp: hash); |
192 | } |
193 | |
194 | static void rt_fibinfo_free_cpus(struct rtable __rcu * __percpu *rtp) |
195 | { |
196 | int cpu; |
197 | |
198 | if (!rtp) |
199 | return; |
200 | |
201 | for_each_possible_cpu(cpu) { |
202 | struct rtable *rt; |
203 | |
204 | rt = rcu_dereference_protected(*per_cpu_ptr(rtp, cpu), 1); |
205 | if (rt) { |
206 | dst_dev_put(dst: &rt->dst); |
207 | dst_release_immediate(dst: &rt->dst); |
208 | } |
209 | } |
210 | free_percpu(pdata: rtp); |
211 | } |
212 | |
213 | void fib_nh_common_release(struct fib_nh_common *nhc) |
214 | { |
215 | netdev_put(dev: nhc->nhc_dev, tracker: &nhc->nhc_dev_tracker); |
216 | lwtstate_put(lws: nhc->nhc_lwtstate); |
217 | rt_fibinfo_free_cpus(rtp: nhc->nhc_pcpu_rth_output); |
218 | rt_fibinfo_free(rtp: &nhc->nhc_rth_input); |
219 | free_nh_exceptions(nhc); |
220 | } |
221 | EXPORT_SYMBOL_GPL(fib_nh_common_release); |
222 | |
223 | void fib_nh_release(struct net *net, struct fib_nh *fib_nh) |
224 | { |
225 | #ifdef CONFIG_IP_ROUTE_CLASSID |
226 | if (fib_nh->nh_tclassid) |
227 | atomic_dec(v: &net->ipv4.fib_num_tclassid_users); |
228 | #endif |
229 | fib_nh_common_release(&fib_nh->nh_common); |
230 | } |
231 | |
232 | /* Release a nexthop info record */ |
233 | static void free_fib_info_rcu(struct rcu_head *head) |
234 | { |
235 | struct fib_info *fi = container_of(head, struct fib_info, rcu); |
236 | |
237 | if (fi->nh) { |
238 | nexthop_put(nh: fi->nh); |
239 | } else { |
240 | change_nexthops(fi) { |
241 | fib_nh_release(net: fi->fib_net, fib_nh: nexthop_nh); |
242 | } endfor_nexthops(fi); |
243 | } |
244 | |
245 | ip_fib_metrics_put(fib_metrics: fi->fib_metrics); |
246 | |
247 | kfree(objp: fi); |
248 | } |
249 | |
250 | void free_fib_info(struct fib_info *fi) |
251 | { |
252 | if (fi->fib_dead == 0) { |
253 | pr_warn("Freeing alive fib_info %p\n" , fi); |
254 | return; |
255 | } |
256 | |
257 | call_rcu(head: &fi->rcu, func: free_fib_info_rcu); |
258 | } |
259 | EXPORT_SYMBOL_GPL(free_fib_info); |
260 | |
261 | void fib_release_info(struct fib_info *fi) |
262 | { |
263 | spin_lock_bh(lock: &fib_info_lock); |
264 | if (fi && refcount_dec_and_test(r: &fi->fib_treeref)) { |
265 | hlist_del(n: &fi->fib_hash); |
266 | |
267 | /* Paired with READ_ONCE() in fib_create_info(). */ |
268 | WRITE_ONCE(fib_info_cnt, fib_info_cnt - 1); |
269 | |
270 | if (fi->fib_prefsrc) |
271 | hlist_del(n: &fi->fib_lhash); |
272 | if (fi->nh) { |
273 | list_del(entry: &fi->nh_list); |
274 | } else { |
275 | change_nexthops(fi) { |
276 | if (!nexthop_nh->fib_nh_dev) |
277 | continue; |
278 | hlist_del(n: &nexthop_nh->nh_hash); |
279 | } endfor_nexthops(fi) |
280 | } |
281 | /* Paired with READ_ONCE() from fib_table_lookup() */ |
282 | WRITE_ONCE(fi->fib_dead, 1); |
283 | fib_info_put(fi); |
284 | } |
285 | spin_unlock_bh(lock: &fib_info_lock); |
286 | } |
287 | |
288 | static inline int nh_comp(struct fib_info *fi, struct fib_info *ofi) |
289 | { |
290 | const struct fib_nh *onh; |
291 | |
292 | if (fi->nh || ofi->nh) |
293 | return nexthop_cmp(nh1: fi->nh, nh2: ofi->nh) ? 0 : -1; |
294 | |
295 | if (ofi->fib_nhs == 0) |
296 | return 0; |
297 | |
298 | for_nexthops(fi) { |
299 | onh = fib_info_nh(fi: ofi, nhsel); |
300 | |
301 | if (nh->fib_nh_oif != onh->fib_nh_oif || |
302 | nh->fib_nh_gw_family != onh->fib_nh_gw_family || |
303 | nh->fib_nh_scope != onh->fib_nh_scope || |
304 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
305 | nh->fib_nh_weight != onh->fib_nh_weight || |
306 | #endif |
307 | #ifdef CONFIG_IP_ROUTE_CLASSID |
308 | nh->nh_tclassid != onh->nh_tclassid || |
309 | #endif |
310 | lwtunnel_cmp_encap(a: nh->fib_nh_lws, b: onh->fib_nh_lws) || |
311 | ((nh->fib_nh_flags ^ onh->fib_nh_flags) & ~RTNH_COMPARE_MASK)) |
312 | return -1; |
313 | |
314 | if (nh->fib_nh_gw_family == AF_INET && |
315 | nh->fib_nh_gw4 != onh->fib_nh_gw4) |
316 | return -1; |
317 | |
318 | if (nh->fib_nh_gw_family == AF_INET6 && |
319 | ipv6_addr_cmp(a1: &nh->fib_nh_gw6, a2: &onh->fib_nh_gw6)) |
320 | return -1; |
321 | } endfor_nexthops(fi); |
322 | return 0; |
323 | } |
324 | |
325 | static inline unsigned int fib_devindex_hashfn(unsigned int val) |
326 | { |
327 | return hash_32(val, DEVINDEX_HASHBITS); |
328 | } |
329 | |
330 | static struct hlist_head * |
331 | fib_info_devhash_bucket(const struct net_device *dev) |
332 | { |
333 | u32 val = net_hash_mix(net: dev_net(dev)) ^ dev->ifindex; |
334 | |
335 | return &fib_info_devhash[fib_devindex_hashfn(val)]; |
336 | } |
337 | |
338 | static unsigned int fib_info_hashfn_1(int init_val, u8 protocol, u8 scope, |
339 | u32 prefsrc, u32 priority) |
340 | { |
341 | unsigned int val = init_val; |
342 | |
343 | val ^= (protocol << 8) | scope; |
344 | val ^= prefsrc; |
345 | val ^= priority; |
346 | |
347 | return val; |
348 | } |
349 | |
350 | static unsigned int fib_info_hashfn_result(unsigned int val) |
351 | { |
352 | unsigned int mask = (fib_info_hash_size - 1); |
353 | |
354 | return (val ^ (val >> 7) ^ (val >> 12)) & mask; |
355 | } |
356 | |
357 | static inline unsigned int fib_info_hashfn(struct fib_info *fi) |
358 | { |
359 | unsigned int val; |
360 | |
361 | val = fib_info_hashfn_1(init_val: fi->fib_nhs, protocol: fi->fib_protocol, |
362 | scope: fi->fib_scope, prefsrc: (__force u32)fi->fib_prefsrc, |
363 | priority: fi->fib_priority); |
364 | |
365 | if (fi->nh) { |
366 | val ^= fib_devindex_hashfn(val: fi->nh->id); |
367 | } else { |
368 | for_nexthops(fi) { |
369 | val ^= fib_devindex_hashfn(val: nh->fib_nh_oif); |
370 | } endfor_nexthops(fi) |
371 | } |
372 | |
373 | return fib_info_hashfn_result(val); |
374 | } |
375 | |
376 | /* no metrics, only nexthop id */ |
377 | static struct fib_info *fib_find_info_nh(struct net *net, |
378 | const struct fib_config *cfg) |
379 | { |
380 | struct hlist_head *head; |
381 | struct fib_info *fi; |
382 | unsigned int hash; |
383 | |
384 | hash = fib_info_hashfn_1(init_val: fib_devindex_hashfn(val: cfg->fc_nh_id), |
385 | protocol: cfg->fc_protocol, scope: cfg->fc_scope, |
386 | prefsrc: (__force u32)cfg->fc_prefsrc, |
387 | priority: cfg->fc_priority); |
388 | hash = fib_info_hashfn_result(val: hash); |
389 | head = &fib_info_hash[hash]; |
390 | |
391 | hlist_for_each_entry(fi, head, fib_hash) { |
392 | if (!net_eq(net1: fi->fib_net, net2: net)) |
393 | continue; |
394 | if (!fi->nh || fi->nh->id != cfg->fc_nh_id) |
395 | continue; |
396 | if (cfg->fc_protocol == fi->fib_protocol && |
397 | cfg->fc_scope == fi->fib_scope && |
398 | cfg->fc_prefsrc == fi->fib_prefsrc && |
399 | cfg->fc_priority == fi->fib_priority && |
400 | cfg->fc_type == fi->fib_type && |
401 | cfg->fc_table == fi->fib_tb_id && |
402 | !((cfg->fc_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK)) |
403 | return fi; |
404 | } |
405 | |
406 | return NULL; |
407 | } |
408 | |
409 | static struct fib_info *fib_find_info(struct fib_info *nfi) |
410 | { |
411 | struct hlist_head *head; |
412 | struct fib_info *fi; |
413 | unsigned int hash; |
414 | |
415 | hash = fib_info_hashfn(fi: nfi); |
416 | head = &fib_info_hash[hash]; |
417 | |
418 | hlist_for_each_entry(fi, head, fib_hash) { |
419 | if (!net_eq(net1: fi->fib_net, net2: nfi->fib_net)) |
420 | continue; |
421 | if (fi->fib_nhs != nfi->fib_nhs) |
422 | continue; |
423 | if (nfi->fib_protocol == fi->fib_protocol && |
424 | nfi->fib_scope == fi->fib_scope && |
425 | nfi->fib_prefsrc == fi->fib_prefsrc && |
426 | nfi->fib_priority == fi->fib_priority && |
427 | nfi->fib_type == fi->fib_type && |
428 | nfi->fib_tb_id == fi->fib_tb_id && |
429 | memcmp(p: nfi->fib_metrics, q: fi->fib_metrics, |
430 | size: sizeof(u32) * RTAX_MAX) == 0 && |
431 | !((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK) && |
432 | nh_comp(fi, ofi: nfi) == 0) |
433 | return fi; |
434 | } |
435 | |
436 | return NULL; |
437 | } |
438 | |
439 | /* Check, that the gateway is already configured. |
440 | * Used only by redirect accept routine. |
441 | */ |
442 | int ip_fib_check_default(__be32 gw, struct net_device *dev) |
443 | { |
444 | struct hlist_head *head; |
445 | struct fib_nh *nh; |
446 | |
447 | spin_lock(lock: &fib_info_lock); |
448 | |
449 | head = fib_info_devhash_bucket(dev); |
450 | |
451 | hlist_for_each_entry(nh, head, nh_hash) { |
452 | if (nh->fib_nh_dev == dev && |
453 | nh->fib_nh_gw4 == gw && |
454 | !(nh->fib_nh_flags & RTNH_F_DEAD)) { |
455 | spin_unlock(lock: &fib_info_lock); |
456 | return 0; |
457 | } |
458 | } |
459 | |
460 | spin_unlock(lock: &fib_info_lock); |
461 | |
462 | return -1; |
463 | } |
464 | |
465 | size_t fib_nlmsg_size(struct fib_info *fi) |
466 | { |
467 | size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg)) |
468 | + nla_total_size(payload: 4) /* RTA_TABLE */ |
469 | + nla_total_size(payload: 4) /* RTA_DST */ |
470 | + nla_total_size(payload: 4) /* RTA_PRIORITY */ |
471 | + nla_total_size(payload: 4) /* RTA_PREFSRC */ |
472 | + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */ |
473 | unsigned int nhs = fib_info_num_path(fi); |
474 | |
475 | /* space for nested metrics */ |
476 | payload += nla_total_size(payload: (RTAX_MAX * nla_total_size(payload: 4))); |
477 | |
478 | if (fi->nh) |
479 | payload += nla_total_size(payload: 4); /* RTA_NH_ID */ |
480 | |
481 | if (nhs) { |
482 | size_t nh_encapsize = 0; |
483 | /* Also handles the special case nhs == 1 */ |
484 | |
485 | /* each nexthop is packed in an attribute */ |
486 | size_t nhsize = nla_total_size(payload: sizeof(struct rtnexthop)); |
487 | unsigned int i; |
488 | |
489 | /* may contain flow and gateway attribute */ |
490 | nhsize += 2 * nla_total_size(payload: 4); |
491 | |
492 | /* grab encap info */ |
493 | for (i = 0; i < fib_info_num_path(fi); i++) { |
494 | struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel: i); |
495 | |
496 | if (nhc->nhc_lwtstate) { |
497 | /* RTA_ENCAP_TYPE */ |
498 | nh_encapsize += lwtunnel_get_encap_size( |
499 | lwtstate: nhc->nhc_lwtstate); |
500 | /* RTA_ENCAP */ |
501 | nh_encapsize += nla_total_size(payload: 2); |
502 | } |
503 | } |
504 | |
505 | /* all nexthops are packed in a nested attribute */ |
506 | payload += nla_total_size(payload: (nhs * nhsize) + nh_encapsize); |
507 | |
508 | } |
509 | |
510 | return payload; |
511 | } |
512 | |
513 | void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, |
514 | int dst_len, u32 tb_id, const struct nl_info *info, |
515 | unsigned int nlm_flags) |
516 | { |
517 | struct fib_rt_info fri; |
518 | struct sk_buff *skb; |
519 | u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; |
520 | int err = -ENOBUFS; |
521 | |
522 | skb = nlmsg_new(payload: fib_nlmsg_size(fi: fa->fa_info), GFP_KERNEL); |
523 | if (!skb) |
524 | goto errout; |
525 | |
526 | fri.fi = fa->fa_info; |
527 | fri.tb_id = tb_id; |
528 | fri.dst = key; |
529 | fri.dst_len = dst_len; |
530 | fri.dscp = fa->fa_dscp; |
531 | fri.type = fa->fa_type; |
532 | fri.offload = READ_ONCE(fa->offload); |
533 | fri.trap = READ_ONCE(fa->trap); |
534 | fri.offload_failed = READ_ONCE(fa->offload_failed); |
535 | err = fib_dump_info(skb, pid: info->portid, seq, event, fri: &fri, flags: nlm_flags); |
536 | if (err < 0) { |
537 | /* -EMSGSIZE implies BUG in fib_nlmsg_size() */ |
538 | WARN_ON(err == -EMSGSIZE); |
539 | kfree_skb(skb); |
540 | goto errout; |
541 | } |
542 | rtnl_notify(skb, net: info->nl_net, pid: info->portid, RTNLGRP_IPV4_ROUTE, |
543 | nlh: info->nlh, GFP_KERNEL); |
544 | return; |
545 | errout: |
546 | if (err < 0) |
547 | rtnl_set_sk_err(net: info->nl_net, RTNLGRP_IPV4_ROUTE, error: err); |
548 | } |
549 | |
550 | static int fib_detect_death(struct fib_info *fi, int order, |
551 | struct fib_info **last_resort, int *last_idx, |
552 | int dflt) |
553 | { |
554 | const struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel: 0); |
555 | struct neighbour *n; |
556 | int state = NUD_NONE; |
557 | |
558 | if (likely(nhc->nhc_gw_family == AF_INET)) |
559 | n = neigh_lookup(tbl: &arp_tbl, pkey: &nhc->nhc_gw.ipv4, dev: nhc->nhc_dev); |
560 | else if (nhc->nhc_gw_family == AF_INET6) |
561 | n = neigh_lookup(tbl: ipv6_stub->nd_tbl, pkey: &nhc->nhc_gw.ipv6, |
562 | dev: nhc->nhc_dev); |
563 | else |
564 | n = NULL; |
565 | |
566 | if (n) { |
567 | state = READ_ONCE(n->nud_state); |
568 | neigh_release(neigh: n); |
569 | } else { |
570 | return 0; |
571 | } |
572 | if (state == NUD_REACHABLE) |
573 | return 0; |
574 | if ((state & NUD_VALID) && order != dflt) |
575 | return 0; |
576 | if ((state & NUD_VALID) || |
577 | (*last_idx < 0 && order > dflt && state != NUD_INCOMPLETE)) { |
578 | *last_resort = fi; |
579 | *last_idx = order; |
580 | } |
581 | return 1; |
582 | } |
583 | |
584 | int fib_nh_common_init(struct net *net, struct fib_nh_common *nhc, |
585 | struct nlattr *encap, u16 encap_type, |
586 | void *cfg, gfp_t gfp_flags, |
587 | struct netlink_ext_ack *extack) |
588 | { |
589 | int err; |
590 | |
591 | nhc->nhc_pcpu_rth_output = alloc_percpu_gfp(struct rtable __rcu *, |
592 | gfp_flags); |
593 | if (!nhc->nhc_pcpu_rth_output) |
594 | return -ENOMEM; |
595 | |
596 | if (encap) { |
597 | struct lwtunnel_state *lwtstate; |
598 | |
599 | if (encap_type == LWTUNNEL_ENCAP_NONE) { |
600 | NL_SET_ERR_MSG(extack, "LWT encap type not specified" ); |
601 | err = -EINVAL; |
602 | goto lwt_failure; |
603 | } |
604 | err = lwtunnel_build_state(net, encap_type, encap, |
605 | family: nhc->nhc_family, cfg, lws: &lwtstate, |
606 | extack); |
607 | if (err) |
608 | goto lwt_failure; |
609 | |
610 | nhc->nhc_lwtstate = lwtstate_get(lws: lwtstate); |
611 | } |
612 | |
613 | return 0; |
614 | |
615 | lwt_failure: |
616 | rt_fibinfo_free_cpus(rtp: nhc->nhc_pcpu_rth_output); |
617 | nhc->nhc_pcpu_rth_output = NULL; |
618 | return err; |
619 | } |
620 | EXPORT_SYMBOL_GPL(fib_nh_common_init); |
621 | |
622 | int fib_nh_init(struct net *net, struct fib_nh *nh, |
623 | struct fib_config *cfg, int nh_weight, |
624 | struct netlink_ext_ack *extack) |
625 | { |
626 | int err; |
627 | |
628 | nh->fib_nh_family = AF_INET; |
629 | |
630 | err = fib_nh_common_init(net, &nh->nh_common, cfg->fc_encap, |
631 | cfg->fc_encap_type, cfg, GFP_KERNEL, extack); |
632 | if (err) |
633 | return err; |
634 | |
635 | nh->fib_nh_oif = cfg->fc_oif; |
636 | nh->fib_nh_gw_family = cfg->fc_gw_family; |
637 | if (cfg->fc_gw_family == AF_INET) |
638 | nh->fib_nh_gw4 = cfg->fc_gw4; |
639 | else if (cfg->fc_gw_family == AF_INET6) |
640 | nh->fib_nh_gw6 = cfg->fc_gw6; |
641 | |
642 | nh->fib_nh_flags = cfg->fc_flags; |
643 | |
644 | #ifdef CONFIG_IP_ROUTE_CLASSID |
645 | nh->nh_tclassid = cfg->fc_flow; |
646 | if (nh->nh_tclassid) |
647 | atomic_inc(v: &net->ipv4.fib_num_tclassid_users); |
648 | #endif |
649 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
650 | nh->fib_nh_weight = nh_weight; |
651 | #endif |
652 | return 0; |
653 | } |
654 | |
655 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
656 | |
657 | static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining, |
658 | struct netlink_ext_ack *extack) |
659 | { |
660 | int nhs = 0; |
661 | |
662 | while (rtnh_ok(rtnh, remaining)) { |
663 | nhs++; |
664 | rtnh = rtnh_next(rtnh, remaining: &remaining); |
665 | } |
666 | |
667 | /* leftover implies invalid nexthop configuration, discard it */ |
668 | if (remaining > 0) { |
669 | NL_SET_ERR_MSG(extack, |
670 | "Invalid nexthop configuration - extra data after nexthops" ); |
671 | nhs = 0; |
672 | } |
673 | |
674 | return nhs; |
675 | } |
676 | |
677 | static int fib_gw_from_attr(__be32 *gw, struct nlattr *nla, |
678 | struct netlink_ext_ack *extack) |
679 | { |
680 | if (nla_len(nla) < sizeof(*gw)) { |
681 | NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_GATEWAY" ); |
682 | return -EINVAL; |
683 | } |
684 | |
685 | *gw = nla_get_in_addr(nla); |
686 | |
687 | return 0; |
688 | } |
689 | |
690 | /* only called when fib_nh is integrated into fib_info */ |
691 | static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, |
692 | int remaining, struct fib_config *cfg, |
693 | struct netlink_ext_ack *extack) |
694 | { |
695 | struct net *net = fi->fib_net; |
696 | struct fib_config fib_cfg; |
697 | struct fib_nh *nh; |
698 | int ret; |
699 | |
700 | change_nexthops(fi) { |
701 | int attrlen; |
702 | |
703 | memset(&fib_cfg, 0, sizeof(fib_cfg)); |
704 | |
705 | if (!rtnh_ok(rtnh, remaining)) { |
706 | NL_SET_ERR_MSG(extack, |
707 | "Invalid nexthop configuration - extra data after nexthop" ); |
708 | return -EINVAL; |
709 | } |
710 | |
711 | if (rtnh->rtnh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) { |
712 | NL_SET_ERR_MSG(extack, |
713 | "Invalid flags for nexthop - can not contain DEAD or LINKDOWN" ); |
714 | return -EINVAL; |
715 | } |
716 | |
717 | fib_cfg.fc_flags = (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags; |
718 | fib_cfg.fc_oif = rtnh->rtnh_ifindex; |
719 | |
720 | attrlen = rtnh_attrlen(rtnh); |
721 | if (attrlen > 0) { |
722 | struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh); |
723 | |
724 | nla = nla_find(head: attrs, len: attrlen, attrtype: RTA_GATEWAY); |
725 | nlav = nla_find(head: attrs, len: attrlen, attrtype: RTA_VIA); |
726 | if (nla && nlav) { |
727 | NL_SET_ERR_MSG(extack, |
728 | "Nexthop configuration can not contain both GATEWAY and VIA" ); |
729 | return -EINVAL; |
730 | } |
731 | if (nla) { |
732 | ret = fib_gw_from_attr(gw: &fib_cfg.fc_gw4, nla, |
733 | extack); |
734 | if (ret) |
735 | goto errout; |
736 | |
737 | if (fib_cfg.fc_gw4) |
738 | fib_cfg.fc_gw_family = AF_INET; |
739 | } else if (nlav) { |
740 | ret = fib_gw_from_via(cfg: &fib_cfg, nla: nlav, extack); |
741 | if (ret) |
742 | goto errout; |
743 | } |
744 | |
745 | nla = nla_find(head: attrs, len: attrlen, attrtype: RTA_FLOW); |
746 | if (nla) { |
747 | if (nla_len(nla) < sizeof(u32)) { |
748 | NL_SET_ERR_MSG(extack, "Invalid RTA_FLOW" ); |
749 | return -EINVAL; |
750 | } |
751 | fib_cfg.fc_flow = nla_get_u32(nla); |
752 | } |
753 | |
754 | fib_cfg.fc_encap = nla_find(head: attrs, len: attrlen, attrtype: RTA_ENCAP); |
755 | /* RTA_ENCAP_TYPE length checked in |
756 | * lwtunnel_valid_encap_type_attr |
757 | */ |
758 | nla = nla_find(head: attrs, len: attrlen, attrtype: RTA_ENCAP_TYPE); |
759 | if (nla) |
760 | fib_cfg.fc_encap_type = nla_get_u16(nla); |
761 | } |
762 | |
763 | ret = fib_nh_init(net, nh: nexthop_nh, cfg: &fib_cfg, |
764 | nh_weight: rtnh->rtnh_hops + 1, extack); |
765 | if (ret) |
766 | goto errout; |
767 | |
768 | rtnh = rtnh_next(rtnh, remaining: &remaining); |
769 | } endfor_nexthops(fi); |
770 | |
771 | ret = -EINVAL; |
772 | nh = fib_info_nh(fi, nhsel: 0); |
773 | if (cfg->fc_oif && nh->fib_nh_oif != cfg->fc_oif) { |
774 | NL_SET_ERR_MSG(extack, |
775 | "Nexthop device index does not match RTA_OIF" ); |
776 | goto errout; |
777 | } |
778 | if (cfg->fc_gw_family) { |
779 | if (cfg->fc_gw_family != nh->fib_nh_gw_family || |
780 | (cfg->fc_gw_family == AF_INET && |
781 | nh->fib_nh_gw4 != cfg->fc_gw4) || |
782 | (cfg->fc_gw_family == AF_INET6 && |
783 | ipv6_addr_cmp(a1: &nh->fib_nh_gw6, a2: &cfg->fc_gw6))) { |
784 | NL_SET_ERR_MSG(extack, |
785 | "Nexthop gateway does not match RTA_GATEWAY or RTA_VIA" ); |
786 | goto errout; |
787 | } |
788 | } |
789 | #ifdef CONFIG_IP_ROUTE_CLASSID |
790 | if (cfg->fc_flow && nh->nh_tclassid != cfg->fc_flow) { |
791 | NL_SET_ERR_MSG(extack, |
792 | "Nexthop class id does not match RTA_FLOW" ); |
793 | goto errout; |
794 | } |
795 | #endif |
796 | ret = 0; |
797 | errout: |
798 | return ret; |
799 | } |
800 | |
801 | /* only called when fib_nh is integrated into fib_info */ |
802 | static void fib_rebalance(struct fib_info *fi) |
803 | { |
804 | int total; |
805 | int w; |
806 | |
807 | if (fib_info_num_path(fi) < 2) |
808 | return; |
809 | |
810 | total = 0; |
811 | for_nexthops(fi) { |
812 | if (nh->fib_nh_flags & RTNH_F_DEAD) |
813 | continue; |
814 | |
815 | if (ip_ignore_linkdown(dev: nh->fib_nh_dev) && |
816 | nh->fib_nh_flags & RTNH_F_LINKDOWN) |
817 | continue; |
818 | |
819 | total += nh->fib_nh_weight; |
820 | } endfor_nexthops(fi); |
821 | |
822 | w = 0; |
823 | change_nexthops(fi) { |
824 | int upper_bound; |
825 | |
826 | if (nexthop_nh->fib_nh_flags & RTNH_F_DEAD) { |
827 | upper_bound = -1; |
828 | } else if (ip_ignore_linkdown(dev: nexthop_nh->fib_nh_dev) && |
829 | nexthop_nh->fib_nh_flags & RTNH_F_LINKDOWN) { |
830 | upper_bound = -1; |
831 | } else { |
832 | w += nexthop_nh->fib_nh_weight; |
833 | upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, |
834 | total) - 1; |
835 | } |
836 | |
837 | atomic_set(v: &nexthop_nh->fib_nh_upper_bound, i: upper_bound); |
838 | } endfor_nexthops(fi); |
839 | } |
840 | #else /* CONFIG_IP_ROUTE_MULTIPATH */ |
841 | |
842 | static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, |
843 | int remaining, struct fib_config *cfg, |
844 | struct netlink_ext_ack *extack) |
845 | { |
846 | NL_SET_ERR_MSG(extack, "Multipath support not enabled in kernel" ); |
847 | |
848 | return -EINVAL; |
849 | } |
850 | |
851 | #define fib_rebalance(fi) do { } while (0) |
852 | |
853 | #endif /* CONFIG_IP_ROUTE_MULTIPATH */ |
854 | |
855 | static int fib_encap_match(struct net *net, u16 encap_type, |
856 | struct nlattr *encap, |
857 | const struct fib_nh *nh, |
858 | const struct fib_config *cfg, |
859 | struct netlink_ext_ack *extack) |
860 | { |
861 | struct lwtunnel_state *lwtstate; |
862 | int ret, result = 0; |
863 | |
864 | if (encap_type == LWTUNNEL_ENCAP_NONE) |
865 | return 0; |
866 | |
867 | ret = lwtunnel_build_state(net, encap_type, encap, AF_INET, |
868 | cfg, lws: &lwtstate, extack); |
869 | if (!ret) { |
870 | result = lwtunnel_cmp_encap(a: lwtstate, b: nh->fib_nh_lws); |
871 | lwtstate_free(lws: lwtstate); |
872 | } |
873 | |
874 | return result; |
875 | } |
876 | |
877 | int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi, |
878 | struct netlink_ext_ack *extack) |
879 | { |
880 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
881 | struct rtnexthop *rtnh; |
882 | int remaining; |
883 | #endif |
884 | |
885 | if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority) |
886 | return 1; |
887 | |
888 | if (cfg->fc_nh_id) { |
889 | if (fi->nh && cfg->fc_nh_id == fi->nh->id) |
890 | return 0; |
891 | return 1; |
892 | } |
893 | |
894 | if (fi->nh) { |
895 | if (cfg->fc_oif || cfg->fc_gw_family || cfg->fc_mp) |
896 | return 1; |
897 | return 0; |
898 | } |
899 | |
900 | if (cfg->fc_oif || cfg->fc_gw_family) { |
901 | struct fib_nh *nh; |
902 | |
903 | nh = fib_info_nh(fi, nhsel: 0); |
904 | if (cfg->fc_encap) { |
905 | if (fib_encap_match(net, encap_type: cfg->fc_encap_type, |
906 | encap: cfg->fc_encap, nh, cfg, extack)) |
907 | return 1; |
908 | } |
909 | #ifdef CONFIG_IP_ROUTE_CLASSID |
910 | if (cfg->fc_flow && |
911 | cfg->fc_flow != nh->nh_tclassid) |
912 | return 1; |
913 | #endif |
914 | if ((cfg->fc_oif && cfg->fc_oif != nh->fib_nh_oif) || |
915 | (cfg->fc_gw_family && |
916 | cfg->fc_gw_family != nh->fib_nh_gw_family)) |
917 | return 1; |
918 | |
919 | if (cfg->fc_gw_family == AF_INET && |
920 | cfg->fc_gw4 != nh->fib_nh_gw4) |
921 | return 1; |
922 | |
923 | if (cfg->fc_gw_family == AF_INET6 && |
924 | ipv6_addr_cmp(a1: &cfg->fc_gw6, a2: &nh->fib_nh_gw6)) |
925 | return 1; |
926 | |
927 | return 0; |
928 | } |
929 | |
930 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
931 | if (!cfg->fc_mp) |
932 | return 0; |
933 | |
934 | rtnh = cfg->fc_mp; |
935 | remaining = cfg->fc_mp_len; |
936 | |
937 | for_nexthops(fi) { |
938 | int attrlen; |
939 | |
940 | if (!rtnh_ok(rtnh, remaining)) |
941 | return -EINVAL; |
942 | |
943 | if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->fib_nh_oif) |
944 | return 1; |
945 | |
946 | attrlen = rtnh_attrlen(rtnh); |
947 | if (attrlen > 0) { |
948 | struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh); |
949 | int err; |
950 | |
951 | nla = nla_find(head: attrs, len: attrlen, attrtype: RTA_GATEWAY); |
952 | nlav = nla_find(head: attrs, len: attrlen, attrtype: RTA_VIA); |
953 | if (nla && nlav) { |
954 | NL_SET_ERR_MSG(extack, |
955 | "Nexthop configuration can not contain both GATEWAY and VIA" ); |
956 | return -EINVAL; |
957 | } |
958 | |
959 | if (nla) { |
960 | __be32 gw; |
961 | |
962 | err = fib_gw_from_attr(gw: &gw, nla, extack); |
963 | if (err) |
964 | return err; |
965 | |
966 | if (nh->fib_nh_gw_family != AF_INET || |
967 | gw != nh->fib_nh_gw4) |
968 | return 1; |
969 | } else if (nlav) { |
970 | struct fib_config cfg2; |
971 | |
972 | err = fib_gw_from_via(cfg: &cfg2, nla: nlav, extack); |
973 | if (err) |
974 | return err; |
975 | |
976 | switch (nh->fib_nh_gw_family) { |
977 | case AF_INET: |
978 | if (cfg2.fc_gw_family != AF_INET || |
979 | cfg2.fc_gw4 != nh->fib_nh_gw4) |
980 | return 1; |
981 | break; |
982 | case AF_INET6: |
983 | if (cfg2.fc_gw_family != AF_INET6 || |
984 | ipv6_addr_cmp(a1: &cfg2.fc_gw6, |
985 | a2: &nh->fib_nh_gw6)) |
986 | return 1; |
987 | break; |
988 | } |
989 | } |
990 | |
991 | #ifdef CONFIG_IP_ROUTE_CLASSID |
992 | nla = nla_find(head: attrs, len: attrlen, attrtype: RTA_FLOW); |
993 | if (nla) { |
994 | if (nla_len(nla) < sizeof(u32)) { |
995 | NL_SET_ERR_MSG(extack, "Invalid RTA_FLOW" ); |
996 | return -EINVAL; |
997 | } |
998 | if (nla_get_u32(nla) != nh->nh_tclassid) |
999 | return 1; |
1000 | } |
1001 | #endif |
1002 | } |
1003 | |
1004 | rtnh = rtnh_next(rtnh, remaining: &remaining); |
1005 | } endfor_nexthops(fi); |
1006 | #endif |
1007 | return 0; |
1008 | } |
1009 | |
1010 | bool fib_metrics_match(struct fib_config *cfg, struct fib_info *fi) |
1011 | { |
1012 | struct nlattr *nla; |
1013 | int remaining; |
1014 | |
1015 | if (!cfg->fc_mx) |
1016 | return true; |
1017 | |
1018 | nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { |
1019 | int type = nla_type(nla); |
1020 | u32 fi_val, val; |
1021 | |
1022 | if (!type) |
1023 | continue; |
1024 | if (type > RTAX_MAX) |
1025 | return false; |
1026 | |
1027 | type = array_index_nospec(type, RTAX_MAX + 1); |
1028 | if (type == RTAX_CC_ALGO) { |
1029 | char tmp[TCP_CA_NAME_MAX]; |
1030 | bool ecn_ca = false; |
1031 | |
1032 | nla_strscpy(dst: tmp, nla, dstsize: sizeof(tmp)); |
1033 | val = tcp_ca_get_key_by_name(net: fi->fib_net, name: tmp, ecn_ca: &ecn_ca); |
1034 | } else { |
1035 | if (nla_len(nla) != sizeof(u32)) |
1036 | return false; |
1037 | val = nla_get_u32(nla); |
1038 | } |
1039 | |
1040 | fi_val = fi->fib_metrics->metrics[type - 1]; |
1041 | if (type == RTAX_FEATURES) |
1042 | fi_val &= ~DST_FEATURE_ECN_CA; |
1043 | |
1044 | if (fi_val != val) |
1045 | return false; |
1046 | } |
1047 | |
1048 | return true; |
1049 | } |
1050 | |
1051 | static int fib_check_nh_v6_gw(struct net *net, struct fib_nh *nh, |
1052 | u32 table, struct netlink_ext_ack *extack) |
1053 | { |
1054 | struct fib6_config cfg = { |
1055 | .fc_table = table, |
1056 | .fc_flags = nh->fib_nh_flags | RTF_GATEWAY, |
1057 | .fc_ifindex = nh->fib_nh_oif, |
1058 | .fc_gateway = nh->fib_nh_gw6, |
1059 | }; |
1060 | struct fib6_nh fib6_nh = {}; |
1061 | int err; |
1062 | |
1063 | err = ipv6_stub->fib6_nh_init(net, &fib6_nh, &cfg, GFP_KERNEL, extack); |
1064 | if (!err) { |
1065 | nh->fib_nh_dev = fib6_nh.fib_nh_dev; |
1066 | netdev_hold(dev: nh->fib_nh_dev, tracker: &nh->fib_nh_dev_tracker, |
1067 | GFP_KERNEL); |
1068 | nh->fib_nh_oif = nh->fib_nh_dev->ifindex; |
1069 | nh->fib_nh_scope = RT_SCOPE_LINK; |
1070 | |
1071 | ipv6_stub->fib6_nh_release(&fib6_nh); |
1072 | } |
1073 | |
1074 | return err; |
1075 | } |
1076 | |
1077 | /* |
1078 | * Picture |
1079 | * ------- |
1080 | * |
1081 | * Semantics of nexthop is very messy by historical reasons. |
1082 | * We have to take into account, that: |
1083 | * a) gateway can be actually local interface address, |
1084 | * so that gatewayed route is direct. |
1085 | * b) gateway must be on-link address, possibly |
1086 | * described not by an ifaddr, but also by a direct route. |
1087 | * c) If both gateway and interface are specified, they should not |
1088 | * contradict. |
1089 | * d) If we use tunnel routes, gateway could be not on-link. |
1090 | * |
1091 | * Attempt to reconcile all of these (alas, self-contradictory) conditions |
1092 | * results in pretty ugly and hairy code with obscure logic. |
1093 | * |
1094 | * I chose to generalized it instead, so that the size |
1095 | * of code does not increase practically, but it becomes |
1096 | * much more general. |
1097 | * Every prefix is assigned a "scope" value: "host" is local address, |
1098 | * "link" is direct route, |
1099 | * [ ... "site" ... "interior" ... ] |
1100 | * and "universe" is true gateway route with global meaning. |
1101 | * |
1102 | * Every prefix refers to a set of "nexthop"s (gw, oif), |
1103 | * where gw must have narrower scope. This recursion stops |
1104 | * when gw has LOCAL scope or if "nexthop" is declared ONLINK, |
1105 | * which means that gw is forced to be on link. |
1106 | * |
1107 | * Code is still hairy, but now it is apparently logically |
1108 | * consistent and very flexible. F.e. as by-product it allows |
1109 | * to co-exists in peace independent exterior and interior |
1110 | * routing processes. |
1111 | * |
1112 | * Normally it looks as following. |
1113 | * |
1114 | * {universe prefix} -> (gw, oif) [scope link] |
1115 | * | |
1116 | * |-> {link prefix} -> (gw, oif) [scope local] |
1117 | * | |
1118 | * |-> {local prefix} (terminal node) |
1119 | */ |
1120 | static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table, |
1121 | u8 scope, struct netlink_ext_ack *extack) |
1122 | { |
1123 | struct net_device *dev; |
1124 | struct fib_result res; |
1125 | int err = 0; |
1126 | |
1127 | if (nh->fib_nh_flags & RTNH_F_ONLINK) { |
1128 | unsigned int addr_type; |
1129 | |
1130 | if (scope >= RT_SCOPE_LINK) { |
1131 | NL_SET_ERR_MSG(extack, "Nexthop has invalid scope" ); |
1132 | return -EINVAL; |
1133 | } |
1134 | dev = __dev_get_by_index(net, ifindex: nh->fib_nh_oif); |
1135 | if (!dev) { |
1136 | NL_SET_ERR_MSG(extack, "Nexthop device required for onlink" ); |
1137 | return -ENODEV; |
1138 | } |
1139 | if (!(dev->flags & IFF_UP)) { |
1140 | NL_SET_ERR_MSG(extack, "Nexthop device is not up" ); |
1141 | return -ENETDOWN; |
1142 | } |
1143 | addr_type = inet_addr_type_dev_table(net, dev, addr: nh->fib_nh_gw4); |
1144 | if (addr_type != RTN_UNICAST) { |
1145 | NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway" ); |
1146 | return -EINVAL; |
1147 | } |
1148 | if (!netif_carrier_ok(dev)) |
1149 | nh->fib_nh_flags |= RTNH_F_LINKDOWN; |
1150 | nh->fib_nh_dev = dev; |
1151 | netdev_hold(dev, tracker: &nh->fib_nh_dev_tracker, GFP_ATOMIC); |
1152 | nh->fib_nh_scope = RT_SCOPE_LINK; |
1153 | return 0; |
1154 | } |
1155 | rcu_read_lock(); |
1156 | { |
1157 | struct fib_table *tbl = NULL; |
1158 | struct flowi4 fl4 = { |
1159 | .daddr = nh->fib_nh_gw4, |
1160 | .flowi4_scope = scope + 1, |
1161 | .flowi4_oif = nh->fib_nh_oif, |
1162 | .flowi4_iif = LOOPBACK_IFINDEX, |
1163 | }; |
1164 | |
1165 | /* It is not necessary, but requires a bit of thinking */ |
1166 | if (fl4.flowi4_scope < RT_SCOPE_LINK) |
1167 | fl4.flowi4_scope = RT_SCOPE_LINK; |
1168 | |
1169 | if (table && table != RT_TABLE_MAIN) |
1170 | tbl = fib_get_table(net, id: table); |
1171 | |
1172 | if (tbl) |
1173 | err = fib_table_lookup(tb: tbl, flp: &fl4, res: &res, |
1174 | FIB_LOOKUP_IGNORE_LINKSTATE | |
1175 | FIB_LOOKUP_NOREF); |
1176 | |
1177 | /* on error or if no table given do full lookup. This |
1178 | * is needed for example when nexthops are in the local |
1179 | * table rather than the given table |
1180 | */ |
1181 | if (!tbl || err) { |
1182 | err = fib_lookup(net, flp: &fl4, res: &res, |
1183 | FIB_LOOKUP_IGNORE_LINKSTATE); |
1184 | } |
1185 | |
1186 | if (err) { |
1187 | NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway" ); |
1188 | goto out; |
1189 | } |
1190 | } |
1191 | |
1192 | err = -EINVAL; |
1193 | if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) { |
1194 | NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway" ); |
1195 | goto out; |
1196 | } |
1197 | nh->fib_nh_scope = res.scope; |
1198 | nh->fib_nh_oif = FIB_RES_OIF(res); |
1199 | nh->fib_nh_dev = dev = FIB_RES_DEV(res); |
1200 | if (!dev) { |
1201 | NL_SET_ERR_MSG(extack, |
1202 | "No egress device for nexthop gateway" ); |
1203 | goto out; |
1204 | } |
1205 | netdev_hold(dev, tracker: &nh->fib_nh_dev_tracker, GFP_ATOMIC); |
1206 | if (!netif_carrier_ok(dev)) |
1207 | nh->fib_nh_flags |= RTNH_F_LINKDOWN; |
1208 | err = (dev->flags & IFF_UP) ? 0 : -ENETDOWN; |
1209 | out: |
1210 | rcu_read_unlock(); |
1211 | return err; |
1212 | } |
1213 | |
1214 | static int fib_check_nh_nongw(struct net *net, struct fib_nh *nh, |
1215 | struct netlink_ext_ack *extack) |
1216 | { |
1217 | struct in_device *in_dev; |
1218 | int err; |
1219 | |
1220 | if (nh->fib_nh_flags & (RTNH_F_PERVASIVE | RTNH_F_ONLINK)) { |
1221 | NL_SET_ERR_MSG(extack, |
1222 | "Invalid flags for nexthop - PERVASIVE and ONLINK can not be set" ); |
1223 | return -EINVAL; |
1224 | } |
1225 | |
1226 | rcu_read_lock(); |
1227 | |
1228 | err = -ENODEV; |
1229 | in_dev = inetdev_by_index(net, nh->fib_nh_oif); |
1230 | if (!in_dev) |
1231 | goto out; |
1232 | err = -ENETDOWN; |
1233 | if (!(in_dev->dev->flags & IFF_UP)) { |
1234 | NL_SET_ERR_MSG(extack, "Device for nexthop is not up" ); |
1235 | goto out; |
1236 | } |
1237 | |
1238 | nh->fib_nh_dev = in_dev->dev; |
1239 | netdev_hold(dev: nh->fib_nh_dev, tracker: &nh->fib_nh_dev_tracker, GFP_ATOMIC); |
1240 | nh->fib_nh_scope = RT_SCOPE_HOST; |
1241 | if (!netif_carrier_ok(dev: nh->fib_nh_dev)) |
1242 | nh->fib_nh_flags |= RTNH_F_LINKDOWN; |
1243 | err = 0; |
1244 | out: |
1245 | rcu_read_unlock(); |
1246 | return err; |
1247 | } |
1248 | |
1249 | int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope, |
1250 | struct netlink_ext_ack *extack) |
1251 | { |
1252 | int err; |
1253 | |
1254 | if (nh->fib_nh_gw_family == AF_INET) |
1255 | err = fib_check_nh_v4_gw(net, nh, table, scope, extack); |
1256 | else if (nh->fib_nh_gw_family == AF_INET6) |
1257 | err = fib_check_nh_v6_gw(net, nh, table, extack); |
1258 | else |
1259 | err = fib_check_nh_nongw(net, nh, extack); |
1260 | |
1261 | return err; |
1262 | } |
1263 | |
1264 | static struct hlist_head * |
1265 | fib_info_laddrhash_bucket(const struct net *net, __be32 val) |
1266 | { |
1267 | u32 slot = hash_32(val: net_hash_mix(net) ^ (__force u32)val, |
1268 | bits: fib_info_hash_bits); |
1269 | |
1270 | return &fib_info_laddrhash[slot]; |
1271 | } |
1272 | |
1273 | static void fib_info_hash_move(struct hlist_head *new_info_hash, |
1274 | struct hlist_head *new_laddrhash, |
1275 | unsigned int new_size) |
1276 | { |
1277 | struct hlist_head *old_info_hash, *old_laddrhash; |
1278 | unsigned int old_size = fib_info_hash_size; |
1279 | unsigned int i; |
1280 | |
1281 | spin_lock_bh(lock: &fib_info_lock); |
1282 | old_info_hash = fib_info_hash; |
1283 | old_laddrhash = fib_info_laddrhash; |
1284 | fib_info_hash_size = new_size; |
1285 | fib_info_hash_bits = ilog2(new_size); |
1286 | |
1287 | for (i = 0; i < old_size; i++) { |
1288 | struct hlist_head *head = &fib_info_hash[i]; |
1289 | struct hlist_node *n; |
1290 | struct fib_info *fi; |
1291 | |
1292 | hlist_for_each_entry_safe(fi, n, head, fib_hash) { |
1293 | struct hlist_head *dest; |
1294 | unsigned int new_hash; |
1295 | |
1296 | new_hash = fib_info_hashfn(fi); |
1297 | dest = &new_info_hash[new_hash]; |
1298 | hlist_add_head(n: &fi->fib_hash, h: dest); |
1299 | } |
1300 | } |
1301 | fib_info_hash = new_info_hash; |
1302 | |
1303 | fib_info_laddrhash = new_laddrhash; |
1304 | for (i = 0; i < old_size; i++) { |
1305 | struct hlist_head *lhead = &old_laddrhash[i]; |
1306 | struct hlist_node *n; |
1307 | struct fib_info *fi; |
1308 | |
1309 | hlist_for_each_entry_safe(fi, n, lhead, fib_lhash) { |
1310 | struct hlist_head *ldest; |
1311 | |
1312 | ldest = fib_info_laddrhash_bucket(net: fi->fib_net, |
1313 | val: fi->fib_prefsrc); |
1314 | hlist_add_head(n: &fi->fib_lhash, h: ldest); |
1315 | } |
1316 | } |
1317 | |
1318 | spin_unlock_bh(lock: &fib_info_lock); |
1319 | |
1320 | kvfree(addr: old_info_hash); |
1321 | kvfree(addr: old_laddrhash); |
1322 | } |
1323 | |
1324 | __be32 fib_info_update_nhc_saddr(struct net *net, struct fib_nh_common *nhc, |
1325 | unsigned char scope) |
1326 | { |
1327 | struct fib_nh *nh; |
1328 | __be32 saddr; |
1329 | |
1330 | if (nhc->nhc_family != AF_INET) |
1331 | return inet_select_addr(dev: nhc->nhc_dev, dst: 0, scope); |
1332 | |
1333 | nh = container_of(nhc, struct fib_nh, nh_common); |
1334 | saddr = inet_select_addr(dev: nh->fib_nh_dev, dst: nh->fib_nh_gw4, scope); |
1335 | |
1336 | WRITE_ONCE(nh->nh_saddr, saddr); |
1337 | WRITE_ONCE(nh->nh_saddr_genid, atomic_read(&net->ipv4.dev_addr_genid)); |
1338 | |
1339 | return saddr; |
1340 | } |
1341 | |
1342 | __be32 fib_result_prefsrc(struct net *net, struct fib_result *res) |
1343 | { |
1344 | struct fib_nh_common *nhc = res->nhc; |
1345 | |
1346 | if (res->fi->fib_prefsrc) |
1347 | return res->fi->fib_prefsrc; |
1348 | |
1349 | if (nhc->nhc_family == AF_INET) { |
1350 | struct fib_nh *nh; |
1351 | |
1352 | nh = container_of(nhc, struct fib_nh, nh_common); |
1353 | if (READ_ONCE(nh->nh_saddr_genid) == |
1354 | atomic_read(v: &net->ipv4.dev_addr_genid)) |
1355 | return READ_ONCE(nh->nh_saddr); |
1356 | } |
1357 | |
1358 | return fib_info_update_nhc_saddr(net, nhc, scope: res->fi->fib_scope); |
1359 | } |
1360 | |
1361 | static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc) |
1362 | { |
1363 | if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst || |
1364 | fib_prefsrc != cfg->fc_dst) { |
1365 | u32 tb_id = cfg->fc_table; |
1366 | int rc; |
1367 | |
1368 | if (tb_id == RT_TABLE_MAIN) |
1369 | tb_id = RT_TABLE_LOCAL; |
1370 | |
1371 | rc = inet_addr_type_table(net: cfg->fc_nlinfo.nl_net, |
1372 | addr: fib_prefsrc, tb_id); |
1373 | |
1374 | if (rc != RTN_LOCAL && tb_id != RT_TABLE_LOCAL) { |
1375 | rc = inet_addr_type_table(net: cfg->fc_nlinfo.nl_net, |
1376 | addr: fib_prefsrc, tb_id: RT_TABLE_LOCAL); |
1377 | } |
1378 | |
1379 | if (rc != RTN_LOCAL) |
1380 | return false; |
1381 | } |
1382 | return true; |
1383 | } |
1384 | |
1385 | struct fib_info *fib_create_info(struct fib_config *cfg, |
1386 | struct netlink_ext_ack *extack) |
1387 | { |
1388 | int err; |
1389 | struct fib_info *fi = NULL; |
1390 | struct nexthop *nh = NULL; |
1391 | struct fib_info *ofi; |
1392 | int nhs = 1; |
1393 | struct net *net = cfg->fc_nlinfo.nl_net; |
1394 | |
1395 | if (cfg->fc_type > RTN_MAX) |
1396 | goto err_inval; |
1397 | |
1398 | /* Fast check to catch the most weird cases */ |
1399 | if (fib_props[cfg->fc_type].scope > cfg->fc_scope) { |
1400 | NL_SET_ERR_MSG(extack, "Invalid scope" ); |
1401 | goto err_inval; |
1402 | } |
1403 | |
1404 | if (cfg->fc_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) { |
1405 | NL_SET_ERR_MSG(extack, |
1406 | "Invalid rtm_flags - can not contain DEAD or LINKDOWN" ); |
1407 | goto err_inval; |
1408 | } |
1409 | |
1410 | if (cfg->fc_nh_id) { |
1411 | if (!cfg->fc_mx) { |
1412 | fi = fib_find_info_nh(net, cfg); |
1413 | if (fi) { |
1414 | refcount_inc(r: &fi->fib_treeref); |
1415 | return fi; |
1416 | } |
1417 | } |
1418 | |
1419 | nh = nexthop_find_by_id(net, id: cfg->fc_nh_id); |
1420 | if (!nh) { |
1421 | NL_SET_ERR_MSG(extack, "Nexthop id does not exist" ); |
1422 | goto err_inval; |
1423 | } |
1424 | nhs = 0; |
1425 | } |
1426 | |
1427 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
1428 | if (cfg->fc_mp) { |
1429 | nhs = fib_count_nexthops(rtnh: cfg->fc_mp, remaining: cfg->fc_mp_len, extack); |
1430 | if (nhs == 0) |
1431 | goto err_inval; |
1432 | } |
1433 | #endif |
1434 | |
1435 | err = -ENOBUFS; |
1436 | |
1437 | /* Paired with WRITE_ONCE() in fib_release_info() */ |
1438 | if (READ_ONCE(fib_info_cnt) >= fib_info_hash_size) { |
1439 | unsigned int new_size = fib_info_hash_size << 1; |
1440 | struct hlist_head *new_info_hash; |
1441 | struct hlist_head *new_laddrhash; |
1442 | size_t bytes; |
1443 | |
1444 | if (!new_size) |
1445 | new_size = 16; |
1446 | bytes = (size_t)new_size * sizeof(struct hlist_head *); |
1447 | new_info_hash = kvzalloc(size: bytes, GFP_KERNEL); |
1448 | new_laddrhash = kvzalloc(size: bytes, GFP_KERNEL); |
1449 | if (!new_info_hash || !new_laddrhash) { |
1450 | kvfree(addr: new_info_hash); |
1451 | kvfree(addr: new_laddrhash); |
1452 | } else { |
1453 | fib_info_hash_move(new_info_hash, new_laddrhash, new_size); |
1454 | } |
1455 | if (!fib_info_hash_size) |
1456 | goto failure; |
1457 | } |
1458 | |
1459 | fi = kzalloc(struct_size(fi, fib_nh, nhs), GFP_KERNEL); |
1460 | if (!fi) |
1461 | goto failure; |
1462 | fi->fib_metrics = ip_fib_metrics_init(net: fi->fib_net, fc_mx: cfg->fc_mx, |
1463 | fc_mx_len: cfg->fc_mx_len, extack); |
1464 | if (IS_ERR(ptr: fi->fib_metrics)) { |
1465 | err = PTR_ERR(ptr: fi->fib_metrics); |
1466 | kfree(objp: fi); |
1467 | return ERR_PTR(error: err); |
1468 | } |
1469 | |
1470 | fi->fib_net = net; |
1471 | fi->fib_protocol = cfg->fc_protocol; |
1472 | fi->fib_scope = cfg->fc_scope; |
1473 | fi->fib_flags = cfg->fc_flags; |
1474 | fi->fib_priority = cfg->fc_priority; |
1475 | fi->fib_prefsrc = cfg->fc_prefsrc; |
1476 | fi->fib_type = cfg->fc_type; |
1477 | fi->fib_tb_id = cfg->fc_table; |
1478 | |
1479 | fi->fib_nhs = nhs; |
1480 | if (nh) { |
1481 | if (!nexthop_get(nh)) { |
1482 | NL_SET_ERR_MSG(extack, "Nexthop has been deleted" ); |
1483 | err = -EINVAL; |
1484 | } else { |
1485 | err = 0; |
1486 | fi->nh = nh; |
1487 | } |
1488 | } else { |
1489 | change_nexthops(fi) { |
1490 | nexthop_nh->nh_parent = fi; |
1491 | } endfor_nexthops(fi) |
1492 | |
1493 | if (cfg->fc_mp) |
1494 | err = fib_get_nhs(fi, rtnh: cfg->fc_mp, remaining: cfg->fc_mp_len, cfg, |
1495 | extack); |
1496 | else |
1497 | err = fib_nh_init(net, nh: fi->fib_nh, cfg, nh_weight: 1, extack); |
1498 | } |
1499 | |
1500 | if (err != 0) |
1501 | goto failure; |
1502 | |
1503 | if (fib_props[cfg->fc_type].error) { |
1504 | if (cfg->fc_gw_family || cfg->fc_oif || cfg->fc_mp) { |
1505 | NL_SET_ERR_MSG(extack, |
1506 | "Gateway, device and multipath can not be specified for this route type" ); |
1507 | goto err_inval; |
1508 | } |
1509 | goto link_it; |
1510 | } else { |
1511 | switch (cfg->fc_type) { |
1512 | case RTN_UNICAST: |
1513 | case RTN_LOCAL: |
1514 | case RTN_BROADCAST: |
1515 | case RTN_ANYCAST: |
1516 | case RTN_MULTICAST: |
1517 | break; |
1518 | default: |
1519 | NL_SET_ERR_MSG(extack, "Invalid route type" ); |
1520 | goto err_inval; |
1521 | } |
1522 | } |
1523 | |
1524 | if (cfg->fc_scope > RT_SCOPE_HOST) { |
1525 | NL_SET_ERR_MSG(extack, "Invalid scope" ); |
1526 | goto err_inval; |
1527 | } |
1528 | |
1529 | if (fi->nh) { |
1530 | err = fib_check_nexthop(nh: fi->nh, scope: cfg->fc_scope, extack); |
1531 | if (err) |
1532 | goto failure; |
1533 | } else if (cfg->fc_scope == RT_SCOPE_HOST) { |
1534 | struct fib_nh *nh = fi->fib_nh; |
1535 | |
1536 | /* Local address is added. */ |
1537 | if (nhs != 1) { |
1538 | NL_SET_ERR_MSG(extack, |
1539 | "Route with host scope can not have multiple nexthops" ); |
1540 | goto err_inval; |
1541 | } |
1542 | if (nh->fib_nh_gw_family) { |
1543 | NL_SET_ERR_MSG(extack, |
1544 | "Route with host scope can not have a gateway" ); |
1545 | goto err_inval; |
1546 | } |
1547 | nh->fib_nh_scope = RT_SCOPE_NOWHERE; |
1548 | nh->fib_nh_dev = dev_get_by_index(net, ifindex: nh->fib_nh_oif); |
1549 | err = -ENODEV; |
1550 | if (!nh->fib_nh_dev) |
1551 | goto failure; |
1552 | netdev_tracker_alloc(dev: nh->fib_nh_dev, tracker: &nh->fib_nh_dev_tracker, |
1553 | GFP_KERNEL); |
1554 | } else { |
1555 | int linkdown = 0; |
1556 | |
1557 | change_nexthops(fi) { |
1558 | err = fib_check_nh(net: cfg->fc_nlinfo.nl_net, nh: nexthop_nh, |
1559 | table: cfg->fc_table, scope: cfg->fc_scope, |
1560 | extack); |
1561 | if (err != 0) |
1562 | goto failure; |
1563 | if (nexthop_nh->fib_nh_flags & RTNH_F_LINKDOWN) |
1564 | linkdown++; |
1565 | } endfor_nexthops(fi) |
1566 | if (linkdown == fi->fib_nhs) |
1567 | fi->fib_flags |= RTNH_F_LINKDOWN; |
1568 | } |
1569 | |
1570 | if (fi->fib_prefsrc && !fib_valid_prefsrc(cfg, fib_prefsrc: fi->fib_prefsrc)) { |
1571 | NL_SET_ERR_MSG(extack, "Invalid prefsrc address" ); |
1572 | goto err_inval; |
1573 | } |
1574 | |
1575 | if (!fi->nh) { |
1576 | change_nexthops(fi) { |
1577 | fib_info_update_nhc_saddr(net, nhc: &nexthop_nh->nh_common, |
1578 | scope: fi->fib_scope); |
1579 | if (nexthop_nh->fib_nh_gw_family == AF_INET6) |
1580 | fi->fib_nh_is_v6 = true; |
1581 | } endfor_nexthops(fi) |
1582 | |
1583 | fib_rebalance(fi); |
1584 | } |
1585 | |
1586 | link_it: |
1587 | ofi = fib_find_info(nfi: fi); |
1588 | if (ofi) { |
1589 | /* fib_table_lookup() should not see @fi yet. */ |
1590 | fi->fib_dead = 1; |
1591 | free_fib_info(fi); |
1592 | refcount_inc(r: &ofi->fib_treeref); |
1593 | return ofi; |
1594 | } |
1595 | |
1596 | refcount_set(r: &fi->fib_treeref, n: 1); |
1597 | refcount_set(r: &fi->fib_clntref, n: 1); |
1598 | spin_lock_bh(lock: &fib_info_lock); |
1599 | fib_info_cnt++; |
1600 | hlist_add_head(n: &fi->fib_hash, |
1601 | h: &fib_info_hash[fib_info_hashfn(fi)]); |
1602 | if (fi->fib_prefsrc) { |
1603 | struct hlist_head *head; |
1604 | |
1605 | head = fib_info_laddrhash_bucket(net, val: fi->fib_prefsrc); |
1606 | hlist_add_head(n: &fi->fib_lhash, h: head); |
1607 | } |
1608 | if (fi->nh) { |
1609 | list_add(new: &fi->nh_list, head: &nh->fi_list); |
1610 | } else { |
1611 | change_nexthops(fi) { |
1612 | struct hlist_head *head; |
1613 | |
1614 | if (!nexthop_nh->fib_nh_dev) |
1615 | continue; |
1616 | head = fib_info_devhash_bucket(dev: nexthop_nh->fib_nh_dev); |
1617 | hlist_add_head(n: &nexthop_nh->nh_hash, h: head); |
1618 | } endfor_nexthops(fi) |
1619 | } |
1620 | spin_unlock_bh(lock: &fib_info_lock); |
1621 | return fi; |
1622 | |
1623 | err_inval: |
1624 | err = -EINVAL; |
1625 | |
1626 | failure: |
1627 | if (fi) { |
1628 | /* fib_table_lookup() should not see @fi yet. */ |
1629 | fi->fib_dead = 1; |
1630 | free_fib_info(fi); |
1631 | } |
1632 | |
1633 | return ERR_PTR(error: err); |
1634 | } |
1635 | |
1636 | int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc, |
1637 | u8 rt_family, unsigned char *flags, bool skip_oif) |
1638 | { |
1639 | if (nhc->nhc_flags & RTNH_F_DEAD) |
1640 | *flags |= RTNH_F_DEAD; |
1641 | |
1642 | if (nhc->nhc_flags & RTNH_F_LINKDOWN) { |
1643 | *flags |= RTNH_F_LINKDOWN; |
1644 | |
1645 | rcu_read_lock(); |
1646 | switch (nhc->nhc_family) { |
1647 | case AF_INET: |
1648 | if (ip_ignore_linkdown(dev: nhc->nhc_dev)) |
1649 | *flags |= RTNH_F_DEAD; |
1650 | break; |
1651 | case AF_INET6: |
1652 | if (ip6_ignore_linkdown(dev: nhc->nhc_dev)) |
1653 | *flags |= RTNH_F_DEAD; |
1654 | break; |
1655 | } |
1656 | rcu_read_unlock(); |
1657 | } |
1658 | |
1659 | switch (nhc->nhc_gw_family) { |
1660 | case AF_INET: |
1661 | if (nla_put_in_addr(skb, attrtype: RTA_GATEWAY, addr: nhc->nhc_gw.ipv4)) |
1662 | goto nla_put_failure; |
1663 | break; |
1664 | case AF_INET6: |
1665 | /* if gateway family does not match nexthop family |
1666 | * gateway is encoded as RTA_VIA |
1667 | */ |
1668 | if (rt_family != nhc->nhc_gw_family) { |
1669 | int alen = sizeof(struct in6_addr); |
1670 | struct nlattr *nla; |
1671 | struct rtvia *via; |
1672 | |
1673 | nla = nla_reserve(skb, attrtype: RTA_VIA, attrlen: alen + 2); |
1674 | if (!nla) |
1675 | goto nla_put_failure; |
1676 | |
1677 | via = nla_data(nla); |
1678 | via->rtvia_family = AF_INET6; |
1679 | memcpy(via->rtvia_addr, &nhc->nhc_gw.ipv6, alen); |
1680 | } else if (nla_put_in6_addr(skb, attrtype: RTA_GATEWAY, |
1681 | addr: &nhc->nhc_gw.ipv6) < 0) { |
1682 | goto nla_put_failure; |
1683 | } |
1684 | break; |
1685 | } |
1686 | |
1687 | *flags |= (nhc->nhc_flags & |
1688 | (RTNH_F_ONLINK | RTNH_F_OFFLOAD | RTNH_F_TRAP)); |
1689 | |
1690 | if (!skip_oif && nhc->nhc_dev && |
1691 | nla_put_u32(skb, attrtype: RTA_OIF, value: nhc->nhc_dev->ifindex)) |
1692 | goto nla_put_failure; |
1693 | |
1694 | if (nhc->nhc_lwtstate && |
1695 | lwtunnel_fill_encap(skb, lwtstate: nhc->nhc_lwtstate, |
1696 | encap_attr: RTA_ENCAP, encap_type_attr: RTA_ENCAP_TYPE) < 0) |
1697 | goto nla_put_failure; |
1698 | |
1699 | return 0; |
1700 | |
1701 | nla_put_failure: |
1702 | return -EMSGSIZE; |
1703 | } |
1704 | EXPORT_SYMBOL_GPL(fib_nexthop_info); |
1705 | |
1706 | #if IS_ENABLED(CONFIG_IP_ROUTE_MULTIPATH) || IS_ENABLED(CONFIG_IPV6) |
1707 | int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc, |
1708 | int nh_weight, u8 rt_family, u32 nh_tclassid) |
1709 | { |
1710 | const struct net_device *dev = nhc->nhc_dev; |
1711 | struct rtnexthop *rtnh; |
1712 | unsigned char flags = 0; |
1713 | |
1714 | rtnh = nla_reserve_nohdr(skb, attrlen: sizeof(*rtnh)); |
1715 | if (!rtnh) |
1716 | goto nla_put_failure; |
1717 | |
1718 | rtnh->rtnh_hops = nh_weight - 1; |
1719 | rtnh->rtnh_ifindex = dev ? dev->ifindex : 0; |
1720 | |
1721 | if (fib_nexthop_info(skb, nhc, rt_family, &flags, true) < 0) |
1722 | goto nla_put_failure; |
1723 | |
1724 | rtnh->rtnh_flags = flags; |
1725 | |
1726 | if (nh_tclassid && nla_put_u32(skb, attrtype: RTA_FLOW, value: nh_tclassid)) |
1727 | goto nla_put_failure; |
1728 | |
1729 | /* length of rtnetlink header + attributes */ |
1730 | rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh; |
1731 | |
1732 | return 0; |
1733 | |
1734 | nla_put_failure: |
1735 | return -EMSGSIZE; |
1736 | } |
1737 | EXPORT_SYMBOL_GPL(fib_add_nexthop); |
1738 | #endif |
1739 | |
1740 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
1741 | static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi) |
1742 | { |
1743 | struct nlattr *mp; |
1744 | |
1745 | mp = nla_nest_start_noflag(skb, attrtype: RTA_MULTIPATH); |
1746 | if (!mp) |
1747 | goto nla_put_failure; |
1748 | |
1749 | if (unlikely(fi->nh)) { |
1750 | if (nexthop_mpath_fill_node(skb, nh: fi->nh, AF_INET) < 0) |
1751 | goto nla_put_failure; |
1752 | goto mp_end; |
1753 | } |
1754 | |
1755 | for_nexthops(fi) { |
1756 | u32 nh_tclassid = 0; |
1757 | #ifdef CONFIG_IP_ROUTE_CLASSID |
1758 | nh_tclassid = nh->nh_tclassid; |
1759 | #endif |
1760 | if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight, |
1761 | AF_INET, nh_tclassid) < 0) |
1762 | goto nla_put_failure; |
1763 | } endfor_nexthops(fi); |
1764 | |
1765 | mp_end: |
1766 | nla_nest_end(skb, start: mp); |
1767 | |
1768 | return 0; |
1769 | |
1770 | nla_put_failure: |
1771 | return -EMSGSIZE; |
1772 | } |
1773 | #else |
1774 | static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi) |
1775 | { |
1776 | return 0; |
1777 | } |
1778 | #endif |
1779 | |
1780 | int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event, |
1781 | const struct fib_rt_info *fri, unsigned int flags) |
1782 | { |
1783 | unsigned int nhs = fib_info_num_path(fi: fri->fi); |
1784 | struct fib_info *fi = fri->fi; |
1785 | u32 tb_id = fri->tb_id; |
1786 | struct nlmsghdr *nlh; |
1787 | struct rtmsg *rtm; |
1788 | |
1789 | nlh = nlmsg_put(skb, portid, seq, type: event, payload: sizeof(*rtm), flags); |
1790 | if (!nlh) |
1791 | return -EMSGSIZE; |
1792 | |
1793 | rtm = nlmsg_data(nlh); |
1794 | rtm->rtm_family = AF_INET; |
1795 | rtm->rtm_dst_len = fri->dst_len; |
1796 | rtm->rtm_src_len = 0; |
1797 | rtm->rtm_tos = inet_dscp_to_dsfield(dscp: fri->dscp); |
1798 | if (tb_id < 256) |
1799 | rtm->rtm_table = tb_id; |
1800 | else |
1801 | rtm->rtm_table = RT_TABLE_COMPAT; |
1802 | if (nla_put_u32(skb, attrtype: RTA_TABLE, value: tb_id)) |
1803 | goto nla_put_failure; |
1804 | rtm->rtm_type = fri->type; |
1805 | rtm->rtm_flags = fi->fib_flags; |
1806 | rtm->rtm_scope = fi->fib_scope; |
1807 | rtm->rtm_protocol = fi->fib_protocol; |
1808 | |
1809 | if (rtm->rtm_dst_len && |
1810 | nla_put_in_addr(skb, attrtype: RTA_DST, addr: fri->dst)) |
1811 | goto nla_put_failure; |
1812 | if (fi->fib_priority && |
1813 | nla_put_u32(skb, attrtype: RTA_PRIORITY, value: fi->fib_priority)) |
1814 | goto nla_put_failure; |
1815 | if (rtnetlink_put_metrics(skb, metrics: fi->fib_metrics->metrics) < 0) |
1816 | goto nla_put_failure; |
1817 | |
1818 | if (fi->fib_prefsrc && |
1819 | nla_put_in_addr(skb, attrtype: RTA_PREFSRC, addr: fi->fib_prefsrc)) |
1820 | goto nla_put_failure; |
1821 | |
1822 | if (fi->nh) { |
1823 | if (nla_put_u32(skb, attrtype: RTA_NH_ID, value: fi->nh->id)) |
1824 | goto nla_put_failure; |
1825 | if (nexthop_is_blackhole(nh: fi->nh)) |
1826 | rtm->rtm_type = RTN_BLACKHOLE; |
1827 | if (!READ_ONCE(fi->fib_net->ipv4.sysctl_nexthop_compat_mode)) |
1828 | goto offload; |
1829 | } |
1830 | |
1831 | if (nhs == 1) { |
1832 | const struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel: 0); |
1833 | unsigned char flags = 0; |
1834 | |
1835 | if (fib_nexthop_info(skb, nhc, AF_INET, &flags, false) < 0) |
1836 | goto nla_put_failure; |
1837 | |
1838 | rtm->rtm_flags = flags; |
1839 | #ifdef CONFIG_IP_ROUTE_CLASSID |
1840 | if (nhc->nhc_family == AF_INET) { |
1841 | struct fib_nh *nh; |
1842 | |
1843 | nh = container_of(nhc, struct fib_nh, nh_common); |
1844 | if (nh->nh_tclassid && |
1845 | nla_put_u32(skb, attrtype: RTA_FLOW, value: nh->nh_tclassid)) |
1846 | goto nla_put_failure; |
1847 | } |
1848 | #endif |
1849 | } else { |
1850 | if (fib_add_multipath(skb, fi) < 0) |
1851 | goto nla_put_failure; |
1852 | } |
1853 | |
1854 | offload: |
1855 | if (fri->offload) |
1856 | rtm->rtm_flags |= RTM_F_OFFLOAD; |
1857 | if (fri->trap) |
1858 | rtm->rtm_flags |= RTM_F_TRAP; |
1859 | if (fri->offload_failed) |
1860 | rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED; |
1861 | |
1862 | nlmsg_end(skb, nlh); |
1863 | return 0; |
1864 | |
1865 | nla_put_failure: |
1866 | nlmsg_cancel(skb, nlh); |
1867 | return -EMSGSIZE; |
1868 | } |
1869 | |
1870 | /* |
1871 | * Update FIB if: |
1872 | * - local address disappeared -> we must delete all the entries |
1873 | * referring to it. |
1874 | * - device went down -> we must shutdown all nexthops going via it. |
1875 | */ |
1876 | int fib_sync_down_addr(struct net_device *dev, __be32 local) |
1877 | { |
1878 | int tb_id = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN; |
1879 | struct net *net = dev_net(dev); |
1880 | struct hlist_head *head; |
1881 | struct fib_info *fi; |
1882 | int ret = 0; |
1883 | |
1884 | if (!fib_info_laddrhash || local == 0) |
1885 | return 0; |
1886 | |
1887 | head = fib_info_laddrhash_bucket(net, val: local); |
1888 | hlist_for_each_entry(fi, head, fib_lhash) { |
1889 | if (!net_eq(net1: fi->fib_net, net2: net) || |
1890 | fi->fib_tb_id != tb_id) |
1891 | continue; |
1892 | if (fi->fib_prefsrc == local) { |
1893 | fi->fib_flags |= RTNH_F_DEAD; |
1894 | fi->pfsrc_removed = true; |
1895 | ret++; |
1896 | } |
1897 | } |
1898 | return ret; |
1899 | } |
1900 | |
1901 | static int call_fib_nh_notifiers(struct fib_nh *nh, |
1902 | enum fib_event_type event_type) |
1903 | { |
1904 | bool ignore_link_down = ip_ignore_linkdown(dev: nh->fib_nh_dev); |
1905 | struct fib_nh_notifier_info info = { |
1906 | .fib_nh = nh, |
1907 | }; |
1908 | |
1909 | switch (event_type) { |
1910 | case FIB_EVENT_NH_ADD: |
1911 | if (nh->fib_nh_flags & RTNH_F_DEAD) |
1912 | break; |
1913 | if (ignore_link_down && nh->fib_nh_flags & RTNH_F_LINKDOWN) |
1914 | break; |
1915 | return call_fib4_notifiers(net: dev_net(dev: nh->fib_nh_dev), event_type, |
1916 | info: &info.info); |
1917 | case FIB_EVENT_NH_DEL: |
1918 | if ((ignore_link_down && nh->fib_nh_flags & RTNH_F_LINKDOWN) || |
1919 | (nh->fib_nh_flags & RTNH_F_DEAD)) |
1920 | return call_fib4_notifiers(net: dev_net(dev: nh->fib_nh_dev), |
1921 | event_type, info: &info.info); |
1922 | break; |
1923 | default: |
1924 | break; |
1925 | } |
1926 | |
1927 | return NOTIFY_DONE; |
1928 | } |
1929 | |
1930 | /* Update the PMTU of exceptions when: |
1931 | * - the new MTU of the first hop becomes smaller than the PMTU |
1932 | * - the old MTU was the same as the PMTU, and it limited discovery of |
1933 | * larger MTUs on the path. With that limit raised, we can now |
1934 | * discover larger MTUs |
1935 | * A special case is locked exceptions, for which the PMTU is smaller |
1936 | * than the minimal accepted PMTU: |
1937 | * - if the new MTU is greater than the PMTU, don't make any change |
1938 | * - otherwise, unlock and set PMTU |
1939 | */ |
1940 | void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig) |
1941 | { |
1942 | struct fnhe_hash_bucket *bucket; |
1943 | int i; |
1944 | |
1945 | bucket = rcu_dereference_protected(nhc->nhc_exceptions, 1); |
1946 | if (!bucket) |
1947 | return; |
1948 | |
1949 | for (i = 0; i < FNHE_HASH_SIZE; i++) { |
1950 | struct fib_nh_exception *fnhe; |
1951 | |
1952 | for (fnhe = rcu_dereference_protected(bucket[i].chain, 1); |
1953 | fnhe; |
1954 | fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1)) { |
1955 | if (fnhe->fnhe_mtu_locked) { |
1956 | if (new <= fnhe->fnhe_pmtu) { |
1957 | fnhe->fnhe_pmtu = new; |
1958 | fnhe->fnhe_mtu_locked = false; |
1959 | } |
1960 | } else if (new < fnhe->fnhe_pmtu || |
1961 | orig == fnhe->fnhe_pmtu) { |
1962 | fnhe->fnhe_pmtu = new; |
1963 | } |
1964 | } |
1965 | } |
1966 | } |
1967 | |
1968 | void fib_sync_mtu(struct net_device *dev, u32 orig_mtu) |
1969 | { |
1970 | struct hlist_head *head = fib_info_devhash_bucket(dev); |
1971 | struct fib_nh *nh; |
1972 | |
1973 | hlist_for_each_entry(nh, head, nh_hash) { |
1974 | if (nh->fib_nh_dev == dev) |
1975 | fib_nhc_update_mtu(nhc: &nh->nh_common, new: dev->mtu, orig: orig_mtu); |
1976 | } |
1977 | } |
1978 | |
1979 | /* Event force Flags Description |
1980 | * NETDEV_CHANGE 0 LINKDOWN Carrier OFF, not for scope host |
1981 | * NETDEV_DOWN 0 LINKDOWN|DEAD Link down, not for scope host |
1982 | * NETDEV_DOWN 1 LINKDOWN|DEAD Last address removed |
1983 | * NETDEV_UNREGISTER 1 LINKDOWN|DEAD Device removed |
1984 | * |
1985 | * only used when fib_nh is built into fib_info |
1986 | */ |
1987 | int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force) |
1988 | { |
1989 | struct hlist_head *head = fib_info_devhash_bucket(dev); |
1990 | struct fib_info *prev_fi = NULL; |
1991 | int scope = RT_SCOPE_NOWHERE; |
1992 | struct fib_nh *nh; |
1993 | int ret = 0; |
1994 | |
1995 | if (force) |
1996 | scope = -1; |
1997 | |
1998 | hlist_for_each_entry(nh, head, nh_hash) { |
1999 | struct fib_info *fi = nh->nh_parent; |
2000 | int dead; |
2001 | |
2002 | BUG_ON(!fi->fib_nhs); |
2003 | if (nh->fib_nh_dev != dev || fi == prev_fi) |
2004 | continue; |
2005 | prev_fi = fi; |
2006 | dead = 0; |
2007 | change_nexthops(fi) { |
2008 | if (nexthop_nh->fib_nh_flags & RTNH_F_DEAD) |
2009 | dead++; |
2010 | else if (nexthop_nh->fib_nh_dev == dev && |
2011 | nexthop_nh->fib_nh_scope != scope) { |
2012 | switch (event) { |
2013 | case NETDEV_DOWN: |
2014 | case NETDEV_UNREGISTER: |
2015 | nexthop_nh->fib_nh_flags |= RTNH_F_DEAD; |
2016 | fallthrough; |
2017 | case NETDEV_CHANGE: |
2018 | nexthop_nh->fib_nh_flags |= RTNH_F_LINKDOWN; |
2019 | break; |
2020 | } |
2021 | call_fib_nh_notifiers(nh: nexthop_nh, |
2022 | event_type: FIB_EVENT_NH_DEL); |
2023 | dead++; |
2024 | } |
2025 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
2026 | if (event == NETDEV_UNREGISTER && |
2027 | nexthop_nh->fib_nh_dev == dev) { |
2028 | dead = fi->fib_nhs; |
2029 | break; |
2030 | } |
2031 | #endif |
2032 | } endfor_nexthops(fi) |
2033 | if (dead == fi->fib_nhs) { |
2034 | switch (event) { |
2035 | case NETDEV_DOWN: |
2036 | case NETDEV_UNREGISTER: |
2037 | fi->fib_flags |= RTNH_F_DEAD; |
2038 | fallthrough; |
2039 | case NETDEV_CHANGE: |
2040 | fi->fib_flags |= RTNH_F_LINKDOWN; |
2041 | break; |
2042 | } |
2043 | ret++; |
2044 | } |
2045 | |
2046 | fib_rebalance(fi); |
2047 | } |
2048 | |
2049 | return ret; |
2050 | } |
2051 | |
2052 | /* Must be invoked inside of an RCU protected region. */ |
2053 | static void fib_select_default(const struct flowi4 *flp, struct fib_result *res) |
2054 | { |
2055 | struct fib_info *fi = NULL, *last_resort = NULL; |
2056 | struct hlist_head *fa_head = res->fa_head; |
2057 | struct fib_table *tb = res->table; |
2058 | u8 slen = 32 - res->prefixlen; |
2059 | int order = -1, last_idx = -1; |
2060 | struct fib_alias *fa, *fa1 = NULL; |
2061 | u32 last_prio = res->fi->fib_priority; |
2062 | dscp_t last_dscp = 0; |
2063 | |
2064 | hlist_for_each_entry_rcu(fa, fa_head, fa_list) { |
2065 | struct fib_info *next_fi = fa->fa_info; |
2066 | struct fib_nh_common *nhc; |
2067 | |
2068 | if (fa->fa_slen != slen) |
2069 | continue; |
2070 | if (fa->fa_dscp && |
2071 | fa->fa_dscp != inet_dsfield_to_dscp(dsfield: flp->flowi4_tos)) |
2072 | continue; |
2073 | if (fa->tb_id != tb->tb_id) |
2074 | continue; |
2075 | if (next_fi->fib_priority > last_prio && |
2076 | fa->fa_dscp == last_dscp) { |
2077 | if (last_dscp) |
2078 | continue; |
2079 | break; |
2080 | } |
2081 | if (next_fi->fib_flags & RTNH_F_DEAD) |
2082 | continue; |
2083 | last_dscp = fa->fa_dscp; |
2084 | last_prio = next_fi->fib_priority; |
2085 | |
2086 | if (next_fi->fib_scope != res->scope || |
2087 | fa->fa_type != RTN_UNICAST) |
2088 | continue; |
2089 | |
2090 | nhc = fib_info_nhc(fi: next_fi, nhsel: 0); |
2091 | if (!nhc->nhc_gw_family || nhc->nhc_scope != RT_SCOPE_LINK) |
2092 | continue; |
2093 | |
2094 | fib_alias_accessed(fa); |
2095 | |
2096 | if (!fi) { |
2097 | if (next_fi != res->fi) |
2098 | break; |
2099 | fa1 = fa; |
2100 | } else if (!fib_detect_death(fi, order, last_resort: &last_resort, |
2101 | last_idx: &last_idx, dflt: fa1->fa_default)) { |
2102 | fib_result_assign(res, fi); |
2103 | fa1->fa_default = order; |
2104 | goto out; |
2105 | } |
2106 | fi = next_fi; |
2107 | order++; |
2108 | } |
2109 | |
2110 | if (order <= 0 || !fi) { |
2111 | if (fa1) |
2112 | fa1->fa_default = -1; |
2113 | goto out; |
2114 | } |
2115 | |
2116 | if (!fib_detect_death(fi, order, last_resort: &last_resort, last_idx: &last_idx, |
2117 | dflt: fa1->fa_default)) { |
2118 | fib_result_assign(res, fi); |
2119 | fa1->fa_default = order; |
2120 | goto out; |
2121 | } |
2122 | |
2123 | if (last_idx >= 0) |
2124 | fib_result_assign(res, fi: last_resort); |
2125 | fa1->fa_default = last_idx; |
2126 | out: |
2127 | return; |
2128 | } |
2129 | |
2130 | /* |
2131 | * Dead device goes up. We wake up dead nexthops. |
2132 | * It takes sense only on multipath routes. |
2133 | * |
2134 | * only used when fib_nh is built into fib_info |
2135 | */ |
2136 | int fib_sync_up(struct net_device *dev, unsigned char nh_flags) |
2137 | { |
2138 | struct fib_info *prev_fi; |
2139 | struct hlist_head *head; |
2140 | struct fib_nh *nh; |
2141 | int ret; |
2142 | |
2143 | if (!(dev->flags & IFF_UP)) |
2144 | return 0; |
2145 | |
2146 | if (nh_flags & RTNH_F_DEAD) { |
2147 | unsigned int flags = dev_get_flags(dev); |
2148 | |
2149 | if (flags & (IFF_RUNNING | IFF_LOWER_UP)) |
2150 | nh_flags |= RTNH_F_LINKDOWN; |
2151 | } |
2152 | |
2153 | prev_fi = NULL; |
2154 | head = fib_info_devhash_bucket(dev); |
2155 | ret = 0; |
2156 | |
2157 | hlist_for_each_entry(nh, head, nh_hash) { |
2158 | struct fib_info *fi = nh->nh_parent; |
2159 | int alive; |
2160 | |
2161 | BUG_ON(!fi->fib_nhs); |
2162 | if (nh->fib_nh_dev != dev || fi == prev_fi) |
2163 | continue; |
2164 | |
2165 | prev_fi = fi; |
2166 | alive = 0; |
2167 | change_nexthops(fi) { |
2168 | if (!(nexthop_nh->fib_nh_flags & nh_flags)) { |
2169 | alive++; |
2170 | continue; |
2171 | } |
2172 | if (!nexthop_nh->fib_nh_dev || |
2173 | !(nexthop_nh->fib_nh_dev->flags & IFF_UP)) |
2174 | continue; |
2175 | if (nexthop_nh->fib_nh_dev != dev || |
2176 | !__in_dev_get_rtnl(dev)) |
2177 | continue; |
2178 | alive++; |
2179 | nexthop_nh->fib_nh_flags &= ~nh_flags; |
2180 | call_fib_nh_notifiers(nh: nexthop_nh, event_type: FIB_EVENT_NH_ADD); |
2181 | } endfor_nexthops(fi) |
2182 | |
2183 | if (alive > 0) { |
2184 | fi->fib_flags &= ~nh_flags; |
2185 | ret++; |
2186 | } |
2187 | |
2188 | fib_rebalance(fi); |
2189 | } |
2190 | |
2191 | return ret; |
2192 | } |
2193 | |
2194 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
2195 | static bool fib_good_nh(const struct fib_nh *nh) |
2196 | { |
2197 | int state = NUD_REACHABLE; |
2198 | |
2199 | if (nh->fib_nh_scope == RT_SCOPE_LINK) { |
2200 | struct neighbour *n; |
2201 | |
2202 | rcu_read_lock(); |
2203 | |
2204 | if (likely(nh->fib_nh_gw_family == AF_INET)) |
2205 | n = __ipv4_neigh_lookup_noref(dev: nh->fib_nh_dev, |
2206 | key: (__force u32)nh->fib_nh_gw4); |
2207 | else if (nh->fib_nh_gw_family == AF_INET6) |
2208 | n = __ipv6_neigh_lookup_noref_stub(dev: nh->fib_nh_dev, |
2209 | pkey: &nh->fib_nh_gw6); |
2210 | else |
2211 | n = NULL; |
2212 | if (n) |
2213 | state = READ_ONCE(n->nud_state); |
2214 | |
2215 | rcu_read_unlock(); |
2216 | } |
2217 | |
2218 | return !!(state & NUD_VALID); |
2219 | } |
2220 | |
2221 | void fib_select_multipath(struct fib_result *res, int hash) |
2222 | { |
2223 | struct fib_info *fi = res->fi; |
2224 | struct net *net = fi->fib_net; |
2225 | bool first = false; |
2226 | |
2227 | if (unlikely(res->fi->nh)) { |
2228 | nexthop_path_fib_result(res, hash); |
2229 | return; |
2230 | } |
2231 | |
2232 | change_nexthops(fi) { |
2233 | if (READ_ONCE(net->ipv4.sysctl_fib_multipath_use_neigh)) { |
2234 | if (!fib_good_nh(nh: nexthop_nh)) |
2235 | continue; |
2236 | if (!first) { |
2237 | res->nh_sel = nhsel; |
2238 | res->nhc = &nexthop_nh->nh_common; |
2239 | first = true; |
2240 | } |
2241 | } |
2242 | |
2243 | if (hash > atomic_read(v: &nexthop_nh->fib_nh_upper_bound)) |
2244 | continue; |
2245 | |
2246 | res->nh_sel = nhsel; |
2247 | res->nhc = &nexthop_nh->nh_common; |
2248 | return; |
2249 | } endfor_nexthops(fi); |
2250 | } |
2251 | #endif |
2252 | |
2253 | void fib_select_path(struct net *net, struct fib_result *res, |
2254 | struct flowi4 *fl4, const struct sk_buff *skb) |
2255 | { |
2256 | if (fl4->flowi4_oif) |
2257 | goto check_saddr; |
2258 | |
2259 | #ifdef CONFIG_IP_ROUTE_MULTIPATH |
2260 | if (fib_info_num_path(fi: res->fi) > 1) { |
2261 | int h = fib_multipath_hash(net, fl4, skb, NULL); |
2262 | |
2263 | fib_select_multipath(res, hash: h); |
2264 | } |
2265 | else |
2266 | #endif |
2267 | if (!res->prefixlen && |
2268 | res->table->tb_num_default > 1 && |
2269 | res->type == RTN_UNICAST) |
2270 | fib_select_default(flp: fl4, res); |
2271 | |
2272 | check_saddr: |
2273 | if (!fl4->saddr) |
2274 | fl4->saddr = fib_result_prefsrc(net, res); |
2275 | } |
2276 | |