Line data Source code
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 :
33 : #include <net/arp.h>
34 : #include <net/ip.h>
35 : #include <net/protocol.h>
36 : #include <net/route.h>
37 : #include <net/tcp.h>
38 : #include <net/sock.h>
39 : #include <net/ip_fib.h>
40 : #include <net/ip6_fib.h>
41 : #include <net/nexthop.h>
42 : #include <net/netlink.h>
43 : #include <net/rtnh.h>
44 : #include <net/lwtunnel.h>
45 : #include <net/fib_notifier.h>
46 : #include <net/addrconf.h>
47 :
48 : #include "fib_lookup.h"
49 :
50 : static DEFINE_SPINLOCK(fib_info_lock);
51 : static struct hlist_head *fib_info_hash;
52 : static struct hlist_head *fib_info_laddrhash;
53 : static unsigned int fib_info_hash_size;
54 : static unsigned int fib_info_cnt;
55 :
56 : #define DEVINDEX_HASHBITS 8
57 : #define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS)
58 : static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE];
59 :
60 : /* for_nexthops and change_nexthops only used when nexthop object
61 : * is not set in a fib_info. The logic within can reference fib_nh.
62 : */
63 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
64 :
65 : #define for_nexthops(fi) { \
66 : int nhsel; const struct fib_nh *nh; \
67 : for (nhsel = 0, nh = (fi)->fib_nh; \
68 : nhsel < fib_info_num_path((fi)); \
69 : nh++, nhsel++)
70 :
71 : #define change_nexthops(fi) { \
72 : int nhsel; struct fib_nh *nexthop_nh; \
73 : for (nhsel = 0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
74 : nhsel < fib_info_num_path((fi)); \
75 : nexthop_nh++, nhsel++)
76 :
77 : #else /* CONFIG_IP_ROUTE_MULTIPATH */
78 :
79 : /* Hope, that gcc will optimize it to get rid of dummy loop */
80 :
81 : #define for_nexthops(fi) { \
82 : int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \
83 : for (nhsel = 0; nhsel < 1; nhsel++)
84 :
85 : #define change_nexthops(fi) { \
86 : int nhsel; \
87 : struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
88 : for (nhsel = 0; nhsel < 1; nhsel++)
89 :
90 : #endif /* CONFIG_IP_ROUTE_MULTIPATH */
91 :
92 : #define endfor_nexthops(fi) }
93 :
94 :
95 : const struct fib_prop fib_props[RTN_MAX + 1] = {
96 : [RTN_UNSPEC] = {
97 : .error = 0,
98 : .scope = RT_SCOPE_NOWHERE,
99 : },
100 : [RTN_UNICAST] = {
101 : .error = 0,
102 : .scope = RT_SCOPE_UNIVERSE,
103 : },
104 : [RTN_LOCAL] = {
105 : .error = 0,
106 : .scope = RT_SCOPE_HOST,
107 : },
108 : [RTN_BROADCAST] = {
109 : .error = 0,
110 : .scope = RT_SCOPE_LINK,
111 : },
112 : [RTN_ANYCAST] = {
113 : .error = 0,
114 : .scope = RT_SCOPE_LINK,
115 : },
116 : [RTN_MULTICAST] = {
117 : .error = 0,
118 : .scope = RT_SCOPE_UNIVERSE,
119 : },
120 : [RTN_BLACKHOLE] = {
121 : .error = -EINVAL,
122 : .scope = RT_SCOPE_UNIVERSE,
123 : },
124 : [RTN_UNREACHABLE] = {
125 : .error = -EHOSTUNREACH,
126 : .scope = RT_SCOPE_UNIVERSE,
127 : },
128 : [RTN_PROHIBIT] = {
129 : .error = -EACCES,
130 : .scope = RT_SCOPE_UNIVERSE,
131 : },
132 : [RTN_THROW] = {
133 : .error = -EAGAIN,
134 : .scope = RT_SCOPE_UNIVERSE,
135 : },
136 : [RTN_NAT] = {
137 : .error = -EINVAL,
138 : .scope = RT_SCOPE_NOWHERE,
139 : },
140 : [RTN_XRESOLVE] = {
141 : .error = -EINVAL,
142 : .scope = RT_SCOPE_NOWHERE,
143 : },
144 : };
145 :
146 5 : static void rt_fibinfo_free(struct rtable __rcu **rtp)
147 : {
148 5 : struct rtable *rt = rcu_dereference_protected(*rtp, 1);
149 :
150 5 : if (!rt)
151 : return;
152 :
153 : /* Not even needed : RCU_INIT_POINTER(*rtp, NULL);
154 : * because we waited an RCU grace period before calling
155 : * free_fib_info_rcu()
156 : */
157 :
158 0 : dst_dev_put(&rt->dst);
159 0 : dst_release_immediate(&rt->dst);
160 : }
161 :
162 5 : static void free_nh_exceptions(struct fib_nh_common *nhc)
163 : {
164 5 : struct fnhe_hash_bucket *hash;
165 5 : int i;
166 :
167 5 : hash = rcu_dereference_protected(nhc->nhc_exceptions, 1);
168 5 : if (!hash)
169 : return;
170 0 : for (i = 0; i < FNHE_HASH_SIZE; i++) {
171 0 : struct fib_nh_exception *fnhe;
172 :
173 0 : fnhe = rcu_dereference_protected(hash[i].chain, 1);
174 0 : while (fnhe) {
175 0 : struct fib_nh_exception *next;
176 :
177 0 : next = rcu_dereference_protected(fnhe->fnhe_next, 1);
178 :
179 0 : rt_fibinfo_free(&fnhe->fnhe_rth_input);
180 0 : rt_fibinfo_free(&fnhe->fnhe_rth_output);
181 :
182 0 : kfree(fnhe);
183 :
184 0 : fnhe = next;
185 : }
186 : }
187 0 : kfree(hash);
188 : }
189 :
190 5 : static void rt_fibinfo_free_cpus(struct rtable __rcu * __percpu *rtp)
191 : {
192 5 : int cpu;
193 :
194 5 : if (!rtp)
195 : return;
196 :
197 25 : for_each_possible_cpu(cpu) {
198 20 : struct rtable *rt;
199 :
200 20 : rt = rcu_dereference_protected(*per_cpu_ptr(rtp, cpu), 1);
201 20 : if (rt) {
202 0 : dst_dev_put(&rt->dst);
203 0 : dst_release_immediate(&rt->dst);
204 : }
205 : }
206 5 : free_percpu(rtp);
207 : }
208 :
209 5 : void fib_nh_common_release(struct fib_nh_common *nhc)
210 : {
211 5 : if (nhc->nhc_dev)
212 5 : dev_put(nhc->nhc_dev);
213 :
214 5 : lwtstate_put(nhc->nhc_lwtstate);
215 5 : rt_fibinfo_free_cpus(nhc->nhc_pcpu_rth_output);
216 5 : rt_fibinfo_free(&nhc->nhc_rth_input);
217 5 : free_nh_exceptions(nhc);
218 5 : }
219 : EXPORT_SYMBOL_GPL(fib_nh_common_release);
220 :
221 5 : void fib_nh_release(struct net *net, struct fib_nh *fib_nh)
222 : {
223 : #ifdef CONFIG_IP_ROUTE_CLASSID
224 : if (fib_nh->nh_tclassid)
225 : net->ipv4.fib_num_tclassid_users--;
226 : #endif
227 0 : fib_nh_common_release(&fib_nh->nh_common);
228 0 : }
229 :
230 : /* Release a nexthop info record */
231 5 : static void free_fib_info_rcu(struct rcu_head *head)
232 : {
233 5 : struct fib_info *fi = container_of(head, struct fib_info, rcu);
234 :
235 5 : if (fi->nh) {
236 0 : nexthop_put(fi->nh);
237 : } else {
238 10 : change_nexthops(fi) {
239 5 : fib_nh_release(fi->fib_net, nexthop_nh);
240 5 : } endfor_nexthops(fi);
241 : }
242 :
243 5 : ip_fib_metrics_put(fi->fib_metrics);
244 :
245 5 : kfree(fi);
246 5 : }
247 :
248 5 : void free_fib_info(struct fib_info *fi)
249 : {
250 5 : if (fi->fib_dead == 0) {
251 0 : pr_warn("Freeing alive fib_info %p\n", fi);
252 0 : return;
253 : }
254 5 : fib_info_cnt--;
255 :
256 5 : call_rcu(&fi->rcu, free_fib_info_rcu);
257 : }
258 : EXPORT_SYMBOL_GPL(free_fib_info);
259 :
260 2 : void fib_release_info(struct fib_info *fi)
261 : {
262 2 : spin_lock_bh(&fib_info_lock);
263 2 : if (fi && --fi->fib_treeref == 0) {
264 0 : hlist_del(&fi->fib_hash);
265 0 : if (fi->fib_prefsrc)
266 0 : hlist_del(&fi->fib_lhash);
267 0 : if (fi->nh) {
268 0 : list_del(&fi->nh_list);
269 : } else {
270 0 : change_nexthops(fi) {
271 0 : if (!nexthop_nh->fib_nh_dev)
272 0 : continue;
273 0 : hlist_del(&nexthop_nh->nh_hash);
274 : } endfor_nexthops(fi)
275 : }
276 0 : fi->fib_dead = 1;
277 0 : fib_info_put(fi);
278 : }
279 2 : spin_unlock_bh(&fib_info_lock);
280 2 : }
281 :
282 5 : static inline int nh_comp(struct fib_info *fi, struct fib_info *ofi)
283 : {
284 5 : const struct fib_nh *onh;
285 :
286 5 : if (fi->nh || ofi->nh)
287 0 : return nexthop_cmp(fi->nh, ofi->nh) ? 0 : -1;
288 :
289 5 : if (ofi->fib_nhs == 0)
290 : return 0;
291 :
292 10 : for_nexthops(fi) {
293 5 : onh = fib_info_nh(ofi, nhsel);
294 :
295 5 : if (nh->fib_nh_oif != onh->fib_nh_oif ||
296 5 : nh->fib_nh_gw_family != onh->fib_nh_gw_family ||
297 : nh->fib_nh_scope != onh->fib_nh_scope ||
298 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
299 : nh->fib_nh_weight != onh->fib_nh_weight ||
300 : #endif
301 : #ifdef CONFIG_IP_ROUTE_CLASSID
302 : nh->nh_tclassid != onh->nh_tclassid ||
303 : #endif
304 5 : lwtunnel_cmp_encap(nh->fib_nh_lws, onh->fib_nh_lws) ||
305 5 : ((nh->fib_nh_flags ^ onh->fib_nh_flags) & ~RTNH_COMPARE_MASK))
306 : return -1;
307 :
308 5 : if (nh->fib_nh_gw_family == AF_INET &&
309 0 : nh->fib_nh_gw4 != onh->fib_nh_gw4)
310 : return -1;
311 :
312 5 : if (nh->fib_nh_gw_family == AF_INET6 &&
313 0 : ipv6_addr_cmp(&nh->fib_nh_gw6, &onh->fib_nh_gw6))
314 : return -1;
315 : } endfor_nexthops(fi);
316 : return 0;
317 : }
318 :
319 26 : static inline unsigned int fib_devindex_hashfn(unsigned int val)
320 : {
321 26 : unsigned int mask = DEVINDEX_HASHSIZE - 1;
322 :
323 26 : return (val ^
324 26 : (val >> DEVINDEX_HASHBITS) ^
325 26 : (val >> (DEVINDEX_HASHBITS * 2))) & mask;
326 : }
327 :
328 19 : static unsigned int fib_info_hashfn_1(int init_val, u8 protocol, u8 scope,
329 : u32 prefsrc, u32 priority)
330 : {
331 19 : unsigned int val = init_val;
332 :
333 19 : val ^= (protocol << 8) | scope;
334 19 : val ^= prefsrc;
335 19 : val ^= priority;
336 :
337 19 : return val;
338 : }
339 :
340 19 : static unsigned int fib_info_hashfn_result(unsigned int val)
341 : {
342 19 : unsigned int mask = (fib_info_hash_size - 1);
343 :
344 19 : return (val ^ (val >> 7) ^ (val >> 12)) & mask;
345 : }
346 :
347 19 : static inline unsigned int fib_info_hashfn(struct fib_info *fi)
348 : {
349 19 : unsigned int val;
350 :
351 19 : val = fib_info_hashfn_1(fi->fib_nhs, fi->fib_protocol,
352 19 : fi->fib_scope, (__force u32)fi->fib_prefsrc,
353 : fi->fib_priority);
354 :
355 19 : if (fi->nh) {
356 0 : val ^= fib_devindex_hashfn(fi->nh->id);
357 : } else {
358 38 : for_nexthops(fi) {
359 19 : val ^= fib_devindex_hashfn(nh->fib_nh_oif);
360 : } endfor_nexthops(fi)
361 : }
362 :
363 19 : return fib_info_hashfn_result(val);
364 : }
365 :
366 : /* no metrics, only nexthop id */
367 0 : static struct fib_info *fib_find_info_nh(struct net *net,
368 : const struct fib_config *cfg)
369 : {
370 0 : struct hlist_head *head;
371 0 : struct fib_info *fi;
372 0 : unsigned int hash;
373 :
374 0 : hash = fib_info_hashfn_1(fib_devindex_hashfn(cfg->fc_nh_id),
375 0 : cfg->fc_protocol, cfg->fc_scope,
376 0 : (__force u32)cfg->fc_prefsrc,
377 : cfg->fc_priority);
378 0 : hash = fib_info_hashfn_result(hash);
379 0 : head = &fib_info_hash[hash];
380 :
381 0 : hlist_for_each_entry(fi, head, fib_hash) {
382 0 : if (!net_eq(fi->fib_net, net))
383 : continue;
384 0 : if (!fi->nh || fi->nh->id != cfg->fc_nh_id)
385 0 : continue;
386 0 : if (cfg->fc_protocol == fi->fib_protocol &&
387 0 : cfg->fc_scope == fi->fib_scope &&
388 0 : cfg->fc_prefsrc == fi->fib_prefsrc &&
389 0 : cfg->fc_priority == fi->fib_priority &&
390 0 : cfg->fc_type == fi->fib_type &&
391 0 : cfg->fc_table == fi->fib_tb_id &&
392 0 : !((cfg->fc_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK))
393 0 : return fi;
394 : }
395 :
396 : return NULL;
397 : }
398 :
399 12 : static struct fib_info *fib_find_info(struct fib_info *nfi)
400 : {
401 12 : struct hlist_head *head;
402 12 : struct fib_info *fi;
403 12 : unsigned int hash;
404 :
405 12 : hash = fib_info_hashfn(nfi);
406 12 : head = &fib_info_hash[hash];
407 :
408 27 : hlist_for_each_entry(fi, head, fib_hash) {
409 8 : if (!net_eq(fi->fib_net, nfi->fib_net))
410 : continue;
411 8 : if (fi->fib_nhs != nfi->fib_nhs)
412 0 : continue;
413 8 : if (nfi->fib_protocol == fi->fib_protocol &&
414 8 : nfi->fib_scope == fi->fib_scope &&
415 8 : nfi->fib_prefsrc == fi->fib_prefsrc &&
416 8 : nfi->fib_priority == fi->fib_priority &&
417 8 : nfi->fib_type == fi->fib_type &&
418 5 : memcmp(nfi->fib_metrics, fi->fib_metrics,
419 5 : sizeof(u32) * RTAX_MAX) == 0 &&
420 10 : !((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK) &&
421 5 : nh_comp(fi, nfi) == 0)
422 5 : return fi;
423 : }
424 :
425 : return NULL;
426 : }
427 :
428 : /* Check, that the gateway is already configured.
429 : * Used only by redirect accept routine.
430 : */
431 0 : int ip_fib_check_default(__be32 gw, struct net_device *dev)
432 : {
433 0 : struct hlist_head *head;
434 0 : struct fib_nh *nh;
435 0 : unsigned int hash;
436 :
437 0 : spin_lock(&fib_info_lock);
438 :
439 0 : hash = fib_devindex_hashfn(dev->ifindex);
440 0 : head = &fib_info_devhash[hash];
441 0 : hlist_for_each_entry(nh, head, nh_hash) {
442 0 : if (nh->fib_nh_dev == dev &&
443 0 : nh->fib_nh_gw4 == gw &&
444 0 : !(nh->fib_nh_flags & RTNH_F_DEAD)) {
445 0 : spin_unlock(&fib_info_lock);
446 0 : return 0;
447 : }
448 : }
449 :
450 0 : spin_unlock(&fib_info_lock);
451 :
452 0 : return -1;
453 : }
454 :
455 10 : size_t fib_nlmsg_size(struct fib_info *fi)
456 : {
457 10 : size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
458 10 : + nla_total_size(4) /* RTA_TABLE */
459 10 : + nla_total_size(4) /* RTA_DST */
460 10 : + nla_total_size(4) /* RTA_PRIORITY */
461 10 : + nla_total_size(4) /* RTA_PREFSRC */
462 10 : + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
463 10 : unsigned int nhs = fib_info_num_path(fi);
464 :
465 : /* space for nested metrics */
466 10 : payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
467 :
468 10 : if (fi->nh)
469 0 : payload += nla_total_size(4); /* RTA_NH_ID */
470 :
471 10 : if (nhs) {
472 : size_t nh_encapsize = 0;
473 : /* Also handles the special case nhs == 1 */
474 :
475 : /* each nexthop is packed in an attribute */
476 20 : size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
477 : unsigned int i;
478 :
479 : /* may contain flow and gateway attribute */
480 20 : nhsize += 2 * nla_total_size(4);
481 :
482 : /* grab encap info */
483 40 : for (i = 0; i < fib_info_num_path(fi); i++) {
484 10 : struct fib_nh_common *nhc = fib_info_nhc(fi, i);
485 :
486 10 : if (nhc->nhc_lwtstate) {
487 : /* RTA_ENCAP_TYPE */
488 0 : nh_encapsize += lwtunnel_get_encap_size(
489 : nhc->nhc_lwtstate);
490 : /* RTA_ENCAP */
491 0 : nh_encapsize += nla_total_size(2);
492 : }
493 : }
494 :
495 : /* all nexthops are packed in a nested attribute */
496 10 : payload += nla_total_size((nhs * nhsize) + nh_encapsize);
497 :
498 : }
499 :
500 10 : return payload;
501 : }
502 :
503 10 : void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
504 : int dst_len, u32 tb_id, const struct nl_info *info,
505 : unsigned int nlm_flags)
506 : {
507 10 : struct fib_rt_info fri;
508 10 : struct sk_buff *skb;
509 10 : u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
510 10 : int err = -ENOBUFS;
511 :
512 10 : skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL);
513 10 : if (!skb)
514 0 : goto errout;
515 :
516 10 : fri.fi = fa->fa_info;
517 10 : fri.tb_id = tb_id;
518 10 : fri.dst = key;
519 10 : fri.dst_len = dst_len;
520 10 : fri.tos = fa->fa_tos;
521 10 : fri.type = fa->fa_type;
522 10 : fri.offload = fa->offload;
523 10 : fri.trap = fa->trap;
524 10 : fri.offload_failed = fa->offload_failed;
525 10 : err = fib_dump_info(skb, info->portid, seq, event, &fri, nlm_flags);
526 10 : if (err < 0) {
527 : /* -EMSGSIZE implies BUG in fib_nlmsg_size() */
528 0 : WARN_ON(err == -EMSGSIZE);
529 0 : kfree_skb(skb);
530 0 : goto errout;
531 : }
532 10 : rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_IPV4_ROUTE,
533 : info->nlh, GFP_KERNEL);
534 10 : return;
535 0 : errout:
536 0 : if (err < 0)
537 0 : rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err);
538 : }
539 :
540 0 : static int fib_detect_death(struct fib_info *fi, int order,
541 : struct fib_info **last_resort, int *last_idx,
542 : int dflt)
543 : {
544 0 : const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
545 0 : struct neighbour *n;
546 0 : int state = NUD_NONE;
547 :
548 0 : if (likely(nhc->nhc_gw_family == AF_INET))
549 0 : n = neigh_lookup(&arp_tbl, &nhc->nhc_gw.ipv4, nhc->nhc_dev);
550 0 : else if (nhc->nhc_gw_family == AF_INET6)
551 0 : n = neigh_lookup(ipv6_stub->nd_tbl, &nhc->nhc_gw.ipv6,
552 : nhc->nhc_dev);
553 : else
554 : n = NULL;
555 :
556 0 : if (n) {
557 0 : state = n->nud_state;
558 0 : neigh_release(n);
559 : } else {
560 0 : return 0;
561 : }
562 0 : if (state == NUD_REACHABLE)
563 : return 0;
564 0 : if ((state & NUD_VALID) && order != dflt)
565 : return 0;
566 0 : if ((state & NUD_VALID) ||
567 0 : (*last_idx < 0 && order > dflt && state != NUD_INCOMPLETE)) {
568 0 : *last_resort = fi;
569 0 : *last_idx = order;
570 : }
571 : return 1;
572 : }
573 :
574 12 : int fib_nh_common_init(struct net *net, struct fib_nh_common *nhc,
575 : struct nlattr *encap, u16 encap_type,
576 : void *cfg, gfp_t gfp_flags,
577 : struct netlink_ext_ack *extack)
578 : {
579 12 : int err;
580 :
581 12 : nhc->nhc_pcpu_rth_output = alloc_percpu_gfp(struct rtable __rcu *,
582 : gfp_flags);
583 12 : if (!nhc->nhc_pcpu_rth_output)
584 : return -ENOMEM;
585 :
586 12 : if (encap) {
587 0 : struct lwtunnel_state *lwtstate;
588 :
589 0 : if (encap_type == LWTUNNEL_ENCAP_NONE) {
590 0 : NL_SET_ERR_MSG(extack, "LWT encap type not specified");
591 0 : err = -EINVAL;
592 0 : goto lwt_failure;
593 : }
594 0 : err = lwtunnel_build_state(net, encap_type, encap,
595 0 : nhc->nhc_family, cfg, &lwtstate,
596 : extack);
597 0 : if (err)
598 0 : goto lwt_failure;
599 :
600 : nhc->nhc_lwtstate = lwtstate_get(lwtstate);
601 : }
602 :
603 : return 0;
604 :
605 0 : lwt_failure:
606 0 : rt_fibinfo_free_cpus(nhc->nhc_pcpu_rth_output);
607 0 : nhc->nhc_pcpu_rth_output = NULL;
608 0 : return err;
609 : }
610 : EXPORT_SYMBOL_GPL(fib_nh_common_init);
611 :
612 12 : int fib_nh_init(struct net *net, struct fib_nh *nh,
613 : struct fib_config *cfg, int nh_weight,
614 : struct netlink_ext_ack *extack)
615 : {
616 12 : int err;
617 :
618 12 : nh->fib_nh_family = AF_INET;
619 :
620 24 : err = fib_nh_common_init(net, &nh->nh_common, cfg->fc_encap,
621 12 : cfg->fc_encap_type, cfg, GFP_KERNEL, extack);
622 12 : if (err)
623 : return err;
624 :
625 12 : nh->fib_nh_oif = cfg->fc_oif;
626 12 : nh->fib_nh_gw_family = cfg->fc_gw_family;
627 12 : if (cfg->fc_gw_family == AF_INET)
628 1 : nh->fib_nh_gw4 = cfg->fc_gw4;
629 11 : else if (cfg->fc_gw_family == AF_INET6)
630 0 : nh->fib_nh_gw6 = cfg->fc_gw6;
631 :
632 12 : nh->fib_nh_flags = cfg->fc_flags;
633 :
634 : #ifdef CONFIG_IP_ROUTE_CLASSID
635 : nh->nh_tclassid = cfg->fc_flow;
636 : if (nh->nh_tclassid)
637 : net->ipv4.fib_num_tclassid_users++;
638 : #endif
639 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
640 : nh->fib_nh_weight = nh_weight;
641 : #endif
642 12 : return 0;
643 : }
644 :
645 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
646 :
647 : static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining,
648 : struct netlink_ext_ack *extack)
649 : {
650 : int nhs = 0;
651 :
652 : while (rtnh_ok(rtnh, remaining)) {
653 : nhs++;
654 : rtnh = rtnh_next(rtnh, &remaining);
655 : }
656 :
657 : /* leftover implies invalid nexthop configuration, discard it */
658 : if (remaining > 0) {
659 : NL_SET_ERR_MSG(extack,
660 : "Invalid nexthop configuration - extra data after nexthops");
661 : nhs = 0;
662 : }
663 :
664 : return nhs;
665 : }
666 :
667 : /* only called when fib_nh is integrated into fib_info */
668 : static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
669 : int remaining, struct fib_config *cfg,
670 : struct netlink_ext_ack *extack)
671 : {
672 : struct net *net = fi->fib_net;
673 : struct fib_config fib_cfg;
674 : struct fib_nh *nh;
675 : int ret;
676 :
677 : change_nexthops(fi) {
678 : int attrlen;
679 :
680 : memset(&fib_cfg, 0, sizeof(fib_cfg));
681 :
682 : if (!rtnh_ok(rtnh, remaining)) {
683 : NL_SET_ERR_MSG(extack,
684 : "Invalid nexthop configuration - extra data after nexthop");
685 : return -EINVAL;
686 : }
687 :
688 : if (rtnh->rtnh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) {
689 : NL_SET_ERR_MSG(extack,
690 : "Invalid flags for nexthop - can not contain DEAD or LINKDOWN");
691 : return -EINVAL;
692 : }
693 :
694 : fib_cfg.fc_flags = (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags;
695 : fib_cfg.fc_oif = rtnh->rtnh_ifindex;
696 :
697 : attrlen = rtnh_attrlen(rtnh);
698 : if (attrlen > 0) {
699 : struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh);
700 :
701 : nla = nla_find(attrs, attrlen, RTA_GATEWAY);
702 : nlav = nla_find(attrs, attrlen, RTA_VIA);
703 : if (nla && nlav) {
704 : NL_SET_ERR_MSG(extack,
705 : "Nexthop configuration can not contain both GATEWAY and VIA");
706 : return -EINVAL;
707 : }
708 : if (nla) {
709 : fib_cfg.fc_gw4 = nla_get_in_addr(nla);
710 : if (fib_cfg.fc_gw4)
711 : fib_cfg.fc_gw_family = AF_INET;
712 : } else if (nlav) {
713 : ret = fib_gw_from_via(&fib_cfg, nlav, extack);
714 : if (ret)
715 : goto errout;
716 : }
717 :
718 : nla = nla_find(attrs, attrlen, RTA_FLOW);
719 : if (nla)
720 : fib_cfg.fc_flow = nla_get_u32(nla);
721 :
722 : fib_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
723 : nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
724 : if (nla)
725 : fib_cfg.fc_encap_type = nla_get_u16(nla);
726 : }
727 :
728 : ret = fib_nh_init(net, nexthop_nh, &fib_cfg,
729 : rtnh->rtnh_hops + 1, extack);
730 : if (ret)
731 : goto errout;
732 :
733 : rtnh = rtnh_next(rtnh, &remaining);
734 : } endfor_nexthops(fi);
735 :
736 : ret = -EINVAL;
737 : nh = fib_info_nh(fi, 0);
738 : if (cfg->fc_oif && nh->fib_nh_oif != cfg->fc_oif) {
739 : NL_SET_ERR_MSG(extack,
740 : "Nexthop device index does not match RTA_OIF");
741 : goto errout;
742 : }
743 : if (cfg->fc_gw_family) {
744 : if (cfg->fc_gw_family != nh->fib_nh_gw_family ||
745 : (cfg->fc_gw_family == AF_INET &&
746 : nh->fib_nh_gw4 != cfg->fc_gw4) ||
747 : (cfg->fc_gw_family == AF_INET6 &&
748 : ipv6_addr_cmp(&nh->fib_nh_gw6, &cfg->fc_gw6))) {
749 : NL_SET_ERR_MSG(extack,
750 : "Nexthop gateway does not match RTA_GATEWAY or RTA_VIA");
751 : goto errout;
752 : }
753 : }
754 : #ifdef CONFIG_IP_ROUTE_CLASSID
755 : if (cfg->fc_flow && nh->nh_tclassid != cfg->fc_flow) {
756 : NL_SET_ERR_MSG(extack,
757 : "Nexthop class id does not match RTA_FLOW");
758 : goto errout;
759 : }
760 : #endif
761 : ret = 0;
762 : errout:
763 : return ret;
764 : }
765 :
766 : /* only called when fib_nh is integrated into fib_info */
767 : static void fib_rebalance(struct fib_info *fi)
768 : {
769 : int total;
770 : int w;
771 :
772 : if (fib_info_num_path(fi) < 2)
773 : return;
774 :
775 : total = 0;
776 : for_nexthops(fi) {
777 : if (nh->fib_nh_flags & RTNH_F_DEAD)
778 : continue;
779 :
780 : if (ip_ignore_linkdown(nh->fib_nh_dev) &&
781 : nh->fib_nh_flags & RTNH_F_LINKDOWN)
782 : continue;
783 :
784 : total += nh->fib_nh_weight;
785 : } endfor_nexthops(fi);
786 :
787 : w = 0;
788 : change_nexthops(fi) {
789 : int upper_bound;
790 :
791 : if (nexthop_nh->fib_nh_flags & RTNH_F_DEAD) {
792 : upper_bound = -1;
793 : } else if (ip_ignore_linkdown(nexthop_nh->fib_nh_dev) &&
794 : nexthop_nh->fib_nh_flags & RTNH_F_LINKDOWN) {
795 : upper_bound = -1;
796 : } else {
797 : w += nexthop_nh->fib_nh_weight;
798 : upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31,
799 : total) - 1;
800 : }
801 :
802 : atomic_set(&nexthop_nh->fib_nh_upper_bound, upper_bound);
803 : } endfor_nexthops(fi);
804 : }
805 : #else /* CONFIG_IP_ROUTE_MULTIPATH */
806 :
807 0 : static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
808 : int remaining, struct fib_config *cfg,
809 : struct netlink_ext_ack *extack)
810 : {
811 0 : NL_SET_ERR_MSG(extack, "Multipath support not enabled in kernel");
812 :
813 : return -EINVAL;
814 : }
815 :
816 : #define fib_rebalance(fi) do { } while (0)
817 :
818 : #endif /* CONFIG_IP_ROUTE_MULTIPATH */
819 :
820 : static int fib_encap_match(struct net *net, u16 encap_type,
821 : struct nlattr *encap,
822 : const struct fib_nh *nh,
823 : const struct fib_config *cfg,
824 : struct netlink_ext_ack *extack)
825 : {
826 : struct lwtunnel_state *lwtstate;
827 : int ret, result = 0;
828 :
829 : if (encap_type == LWTUNNEL_ENCAP_NONE)
830 : return 0;
831 :
832 : ret = lwtunnel_build_state(net, encap_type, encap, AF_INET,
833 : cfg, &lwtstate, extack);
834 : if (!ret) {
835 : result = lwtunnel_cmp_encap(lwtstate, nh->fib_nh_lws);
836 : lwtstate_free(lwtstate);
837 : }
838 :
839 : return result;
840 : }
841 :
842 0 : int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi,
843 : struct netlink_ext_ack *extack)
844 : {
845 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
846 : struct rtnexthop *rtnh;
847 : int remaining;
848 : #endif
849 :
850 0 : if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority)
851 : return 1;
852 :
853 0 : if (cfg->fc_nh_id) {
854 0 : if (fi->nh && cfg->fc_nh_id == fi->nh->id)
855 : return 0;
856 0 : return 1;
857 : }
858 :
859 0 : if (cfg->fc_oif || cfg->fc_gw_family) {
860 0 : struct fib_nh *nh = fib_info_nh(fi, 0);
861 :
862 0 : if (cfg->fc_encap) {
863 : if (fib_encap_match(net, cfg->fc_encap_type,
864 : cfg->fc_encap, nh, cfg, extack))
865 : return 1;
866 : }
867 : #ifdef CONFIG_IP_ROUTE_CLASSID
868 : if (cfg->fc_flow &&
869 : cfg->fc_flow != nh->nh_tclassid)
870 : return 1;
871 : #endif
872 0 : if ((cfg->fc_oif && cfg->fc_oif != nh->fib_nh_oif) ||
873 0 : (cfg->fc_gw_family &&
874 0 : cfg->fc_gw_family != nh->fib_nh_gw_family))
875 : return 1;
876 :
877 0 : if (cfg->fc_gw_family == AF_INET &&
878 0 : cfg->fc_gw4 != nh->fib_nh_gw4)
879 : return 1;
880 :
881 0 : if (cfg->fc_gw_family == AF_INET6 &&
882 0 : ipv6_addr_cmp(&cfg->fc_gw6, &nh->fib_nh_gw6))
883 : return 1;
884 :
885 0 : return 0;
886 : }
887 :
888 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
889 : if (!cfg->fc_mp)
890 : return 0;
891 :
892 : rtnh = cfg->fc_mp;
893 : remaining = cfg->fc_mp_len;
894 :
895 : for_nexthops(fi) {
896 : int attrlen;
897 :
898 : if (!rtnh_ok(rtnh, remaining))
899 : return -EINVAL;
900 :
901 : if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->fib_nh_oif)
902 : return 1;
903 :
904 : attrlen = rtnh_attrlen(rtnh);
905 : if (attrlen > 0) {
906 : struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh);
907 :
908 : nla = nla_find(attrs, attrlen, RTA_GATEWAY);
909 : nlav = nla_find(attrs, attrlen, RTA_VIA);
910 : if (nla && nlav) {
911 : NL_SET_ERR_MSG(extack,
912 : "Nexthop configuration can not contain both GATEWAY and VIA");
913 : return -EINVAL;
914 : }
915 :
916 : if (nla) {
917 : if (nh->fib_nh_gw_family != AF_INET ||
918 : nla_get_in_addr(nla) != nh->fib_nh_gw4)
919 : return 1;
920 : } else if (nlav) {
921 : struct fib_config cfg2;
922 : int err;
923 :
924 : err = fib_gw_from_via(&cfg2, nlav, extack);
925 : if (err)
926 : return err;
927 :
928 : switch (nh->fib_nh_gw_family) {
929 : case AF_INET:
930 : if (cfg2.fc_gw_family != AF_INET ||
931 : cfg2.fc_gw4 != nh->fib_nh_gw4)
932 : return 1;
933 : break;
934 : case AF_INET6:
935 : if (cfg2.fc_gw_family != AF_INET6 ||
936 : ipv6_addr_cmp(&cfg2.fc_gw6,
937 : &nh->fib_nh_gw6))
938 : return 1;
939 : break;
940 : }
941 : }
942 :
943 : #ifdef CONFIG_IP_ROUTE_CLASSID
944 : nla = nla_find(attrs, attrlen, RTA_FLOW);
945 : if (nla && nla_get_u32(nla) != nh->nh_tclassid)
946 : return 1;
947 : #endif
948 : }
949 :
950 : rtnh = rtnh_next(rtnh, &remaining);
951 : } endfor_nexthops(fi);
952 : #endif
953 : return 0;
954 : }
955 :
956 0 : bool fib_metrics_match(struct fib_config *cfg, struct fib_info *fi)
957 : {
958 0 : struct nlattr *nla;
959 0 : int remaining;
960 :
961 0 : if (!cfg->fc_mx)
962 : return true;
963 :
964 0 : nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
965 0 : int type = nla_type(nla);
966 0 : u32 fi_val, val;
967 :
968 0 : if (!type)
969 0 : continue;
970 0 : if (type > RTAX_MAX)
971 : return false;
972 :
973 0 : if (type == RTAX_CC_ALGO) {
974 0 : char tmp[TCP_CA_NAME_MAX];
975 0 : bool ecn_ca = false;
976 :
977 0 : nla_strscpy(tmp, nla, sizeof(tmp));
978 0 : val = tcp_ca_get_key_by_name(fi->fib_net, tmp, &ecn_ca);
979 : } else {
980 0 : if (nla_len(nla) != sizeof(u32))
981 : return false;
982 0 : val = nla_get_u32(nla);
983 : }
984 :
985 0 : fi_val = fi->fib_metrics->metrics[type - 1];
986 0 : if (type == RTAX_FEATURES)
987 0 : fi_val &= ~DST_FEATURE_ECN_CA;
988 :
989 0 : if (fi_val != val)
990 : return false;
991 : }
992 :
993 : return true;
994 : }
995 :
996 0 : static int fib_check_nh_v6_gw(struct net *net, struct fib_nh *nh,
997 : u32 table, struct netlink_ext_ack *extack)
998 : {
999 0 : struct fib6_config cfg = {
1000 : .fc_table = table,
1001 0 : .fc_flags = nh->fib_nh_flags | RTF_GATEWAY,
1002 0 : .fc_ifindex = nh->fib_nh_oif,
1003 : .fc_gateway = nh->fib_nh_gw6,
1004 : };
1005 0 : struct fib6_nh fib6_nh = {};
1006 0 : int err;
1007 :
1008 0 : err = ipv6_stub->fib6_nh_init(net, &fib6_nh, &cfg, GFP_KERNEL, extack);
1009 0 : if (!err) {
1010 0 : nh->fib_nh_dev = fib6_nh.fib_nh_dev;
1011 0 : dev_hold(nh->fib_nh_dev);
1012 0 : nh->fib_nh_oif = nh->fib_nh_dev->ifindex;
1013 0 : nh->fib_nh_scope = RT_SCOPE_LINK;
1014 :
1015 0 : ipv6_stub->fib6_nh_release(&fib6_nh);
1016 : }
1017 :
1018 0 : return err;
1019 : }
1020 :
1021 : /*
1022 : * Picture
1023 : * -------
1024 : *
1025 : * Semantics of nexthop is very messy by historical reasons.
1026 : * We have to take into account, that:
1027 : * a) gateway can be actually local interface address,
1028 : * so that gatewayed route is direct.
1029 : * b) gateway must be on-link address, possibly
1030 : * described not by an ifaddr, but also by a direct route.
1031 : * c) If both gateway and interface are specified, they should not
1032 : * contradict.
1033 : * d) If we use tunnel routes, gateway could be not on-link.
1034 : *
1035 : * Attempt to reconcile all of these (alas, self-contradictory) conditions
1036 : * results in pretty ugly and hairy code with obscure logic.
1037 : *
1038 : * I chose to generalized it instead, so that the size
1039 : * of code does not increase practically, but it becomes
1040 : * much more general.
1041 : * Every prefix is assigned a "scope" value: "host" is local address,
1042 : * "link" is direct route,
1043 : * [ ... "site" ... "interior" ... ]
1044 : * and "universe" is true gateway route with global meaning.
1045 : *
1046 : * Every prefix refers to a set of "nexthop"s (gw, oif),
1047 : * where gw must have narrower scope. This recursion stops
1048 : * when gw has LOCAL scope or if "nexthop" is declared ONLINK,
1049 : * which means that gw is forced to be on link.
1050 : *
1051 : * Code is still hairy, but now it is apparently logically
1052 : * consistent and very flexible. F.e. as by-product it allows
1053 : * to co-exists in peace independent exterior and interior
1054 : * routing processes.
1055 : *
1056 : * Normally it looks as following.
1057 : *
1058 : * {universe prefix} -> (gw, oif) [scope link]
1059 : * |
1060 : * |-> {link prefix} -> (gw, oif) [scope local]
1061 : * |
1062 : * |-> {local prefix} (terminal node)
1063 : */
1064 1 : static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table,
1065 : u8 scope, struct netlink_ext_ack *extack)
1066 : {
1067 1 : struct net_device *dev;
1068 1 : struct fib_result res;
1069 1 : int err = 0;
1070 :
1071 1 : if (nh->fib_nh_flags & RTNH_F_ONLINK) {
1072 0 : unsigned int addr_type;
1073 :
1074 0 : if (scope >= RT_SCOPE_LINK) {
1075 0 : NL_SET_ERR_MSG(extack, "Nexthop has invalid scope");
1076 0 : return -EINVAL;
1077 : }
1078 0 : dev = __dev_get_by_index(net, nh->fib_nh_oif);
1079 0 : if (!dev) {
1080 0 : NL_SET_ERR_MSG(extack, "Nexthop device required for onlink");
1081 0 : return -ENODEV;
1082 : }
1083 0 : if (!(dev->flags & IFF_UP)) {
1084 0 : NL_SET_ERR_MSG(extack, "Nexthop device is not up");
1085 0 : return -ENETDOWN;
1086 : }
1087 0 : addr_type = inet_addr_type_dev_table(net, dev, nh->fib_nh_gw4);
1088 0 : if (addr_type != RTN_UNICAST) {
1089 0 : NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway");
1090 0 : return -EINVAL;
1091 : }
1092 0 : if (!netif_carrier_ok(dev))
1093 0 : nh->fib_nh_flags |= RTNH_F_LINKDOWN;
1094 0 : nh->fib_nh_dev = dev;
1095 0 : dev_hold(dev);
1096 0 : nh->fib_nh_scope = RT_SCOPE_LINK;
1097 0 : return 0;
1098 : }
1099 1 : rcu_read_lock();
1100 : {
1101 1 : struct fib_table *tbl = NULL;
1102 1 : struct flowi4 fl4 = {
1103 1 : .daddr = nh->fib_nh_gw4,
1104 1 : .flowi4_scope = scope + 1,
1105 1 : .flowi4_oif = nh->fib_nh_oif,
1106 : .flowi4_iif = LOOPBACK_IFINDEX,
1107 : };
1108 :
1109 : /* It is not necessary, but requires a bit of thinking */
1110 1 : if (fl4.flowi4_scope < RT_SCOPE_LINK)
1111 1 : fl4.flowi4_scope = RT_SCOPE_LINK;
1112 :
1113 1 : if (table && table != RT_TABLE_MAIN)
1114 0 : tbl = fib_get_table(net, table);
1115 :
1116 0 : if (tbl)
1117 0 : err = fib_table_lookup(tbl, &fl4, &res,
1118 : FIB_LOOKUP_IGNORE_LINKSTATE |
1119 : FIB_LOOKUP_NOREF);
1120 :
1121 : /* on error or if no table given do full lookup. This
1122 : * is needed for example when nexthops are in the local
1123 : * table rather than the given table
1124 : */
1125 1 : if (!tbl || err) {
1126 1 : err = fib_lookup(net, &fl4, &res,
1127 : FIB_LOOKUP_IGNORE_LINKSTATE);
1128 : }
1129 :
1130 1 : if (err) {
1131 0 : NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway");
1132 0 : goto out;
1133 : }
1134 : }
1135 :
1136 1 : err = -EINVAL;
1137 1 : if (res.type != RTN_UNICAST && res.type != RTN_LOCAL) {
1138 0 : NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway");
1139 0 : goto out;
1140 : }
1141 1 : nh->fib_nh_scope = res.scope;
1142 1 : nh->fib_nh_oif = FIB_RES_OIF(res);
1143 1 : nh->fib_nh_dev = dev = FIB_RES_DEV(res);
1144 1 : if (!dev) {
1145 0 : NL_SET_ERR_MSG(extack,
1146 : "No egress device for nexthop gateway");
1147 0 : goto out;
1148 : }
1149 1 : dev_hold(dev);
1150 1 : if (!netif_carrier_ok(dev))
1151 0 : nh->fib_nh_flags |= RTNH_F_LINKDOWN;
1152 1 : err = (dev->flags & IFF_UP) ? 0 : -ENETDOWN;
1153 1 : out:
1154 1 : rcu_read_unlock();
1155 1 : return err;
1156 : }
1157 :
1158 7 : static int fib_check_nh_nongw(struct net *net, struct fib_nh *nh,
1159 : struct netlink_ext_ack *extack)
1160 : {
1161 7 : struct in_device *in_dev;
1162 7 : int err;
1163 :
1164 7 : if (nh->fib_nh_flags & (RTNH_F_PERVASIVE | RTNH_F_ONLINK)) {
1165 0 : NL_SET_ERR_MSG(extack,
1166 : "Invalid flags for nexthop - PERVASIVE and ONLINK can not be set");
1167 0 : return -EINVAL;
1168 : }
1169 :
1170 7 : rcu_read_lock();
1171 :
1172 7 : err = -ENODEV;
1173 7 : in_dev = inetdev_by_index(net, nh->fib_nh_oif);
1174 7 : if (!in_dev)
1175 0 : goto out;
1176 7 : err = -ENETDOWN;
1177 7 : if (!(in_dev->dev->flags & IFF_UP)) {
1178 0 : NL_SET_ERR_MSG(extack, "Device for nexthop is not up");
1179 0 : goto out;
1180 : }
1181 :
1182 7 : nh->fib_nh_dev = in_dev->dev;
1183 7 : dev_hold(nh->fib_nh_dev);
1184 7 : nh->fib_nh_scope = RT_SCOPE_HOST;
1185 7 : if (!netif_carrier_ok(nh->fib_nh_dev))
1186 0 : nh->fib_nh_flags |= RTNH_F_LINKDOWN;
1187 : err = 0;
1188 7 : out:
1189 7 : rcu_read_unlock();
1190 7 : return err;
1191 : }
1192 :
1193 8 : int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope,
1194 : struct netlink_ext_ack *extack)
1195 : {
1196 8 : int err;
1197 :
1198 8 : if (nh->fib_nh_gw_family == AF_INET)
1199 1 : err = fib_check_nh_v4_gw(net, nh, table, scope, extack);
1200 7 : else if (nh->fib_nh_gw_family == AF_INET6)
1201 0 : err = fib_check_nh_v6_gw(net, nh, table, extack);
1202 : else
1203 7 : err = fib_check_nh_nongw(net, nh, extack);
1204 :
1205 8 : return err;
1206 : }
1207 :
1208 5 : static inline unsigned int fib_laddr_hashfn(__be32 val)
1209 : {
1210 5 : unsigned int mask = (fib_info_hash_size - 1);
1211 :
1212 5 : return ((__force u32)val ^
1213 5 : ((__force u32)val >> 7) ^
1214 5 : ((__force u32)val >> 14)) & mask;
1215 : }
1216 :
1217 2 : static struct hlist_head *fib_info_hash_alloc(int bytes)
1218 : {
1219 2 : if (bytes <= PAGE_SIZE)
1220 2 : return kzalloc(bytes, GFP_KERNEL);
1221 : else
1222 0 : return (struct hlist_head *)
1223 0 : __get_free_pages(GFP_KERNEL | __GFP_ZERO,
1224 0 : get_order(bytes));
1225 : }
1226 :
1227 2 : static void fib_info_hash_free(struct hlist_head *hash, int bytes)
1228 : {
1229 2 : if (!hash)
1230 : return;
1231 :
1232 0 : if (bytes <= PAGE_SIZE)
1233 0 : kfree(hash);
1234 : else
1235 0 : free_pages((unsigned long) hash, get_order(bytes));
1236 : }
1237 :
1238 1 : static void fib_info_hash_move(struct hlist_head *new_info_hash,
1239 : struct hlist_head *new_laddrhash,
1240 : unsigned int new_size)
1241 : {
1242 1 : struct hlist_head *old_info_hash, *old_laddrhash;
1243 1 : unsigned int old_size = fib_info_hash_size;
1244 1 : unsigned int i, bytes;
1245 :
1246 1 : spin_lock_bh(&fib_info_lock);
1247 1 : old_info_hash = fib_info_hash;
1248 1 : old_laddrhash = fib_info_laddrhash;
1249 1 : fib_info_hash_size = new_size;
1250 :
1251 1 : for (i = 0; i < old_size; i++) {
1252 0 : struct hlist_head *head = &fib_info_hash[i];
1253 0 : struct hlist_node *n;
1254 0 : struct fib_info *fi;
1255 :
1256 0 : hlist_for_each_entry_safe(fi, n, head, fib_hash) {
1257 0 : struct hlist_head *dest;
1258 0 : unsigned int new_hash;
1259 :
1260 0 : new_hash = fib_info_hashfn(fi);
1261 0 : dest = &new_info_hash[new_hash];
1262 0 : hlist_add_head(&fi->fib_hash, dest);
1263 : }
1264 : }
1265 1 : fib_info_hash = new_info_hash;
1266 :
1267 1 : for (i = 0; i < old_size; i++) {
1268 0 : struct hlist_head *lhead = &fib_info_laddrhash[i];
1269 0 : struct hlist_node *n;
1270 0 : struct fib_info *fi;
1271 :
1272 0 : hlist_for_each_entry_safe(fi, n, lhead, fib_lhash) {
1273 0 : struct hlist_head *ldest;
1274 0 : unsigned int new_hash;
1275 :
1276 0 : new_hash = fib_laddr_hashfn(fi->fib_prefsrc);
1277 0 : ldest = &new_laddrhash[new_hash];
1278 0 : hlist_add_head(&fi->fib_lhash, ldest);
1279 : }
1280 : }
1281 1 : fib_info_laddrhash = new_laddrhash;
1282 :
1283 1 : spin_unlock_bh(&fib_info_lock);
1284 :
1285 1 : bytes = old_size * sizeof(struct hlist_head *);
1286 1 : fib_info_hash_free(old_info_hash, bytes);
1287 1 : fib_info_hash_free(old_laddrhash, bytes);
1288 1 : }
1289 :
1290 12 : __be32 fib_info_update_nhc_saddr(struct net *net, struct fib_nh_common *nhc,
1291 : unsigned char scope)
1292 : {
1293 12 : struct fib_nh *nh;
1294 :
1295 12 : if (nhc->nhc_family != AF_INET)
1296 0 : return inet_select_addr(nhc->nhc_dev, 0, scope);
1297 :
1298 12 : nh = container_of(nhc, struct fib_nh, nh_common);
1299 12 : nh->nh_saddr = inet_select_addr(nh->fib_nh_dev, nh->fib_nh_gw4, scope);
1300 12 : nh->nh_saddr_genid = atomic_read(&net->ipv4.dev_addr_genid);
1301 :
1302 12 : return nh->nh_saddr;
1303 : }
1304 :
1305 7 : __be32 fib_result_prefsrc(struct net *net, struct fib_result *res)
1306 : {
1307 7 : struct fib_nh_common *nhc = res->nhc;
1308 :
1309 7 : if (res->fi->fib_prefsrc)
1310 : return res->fi->fib_prefsrc;
1311 :
1312 0 : if (nhc->nhc_family == AF_INET) {
1313 0 : struct fib_nh *nh;
1314 :
1315 0 : nh = container_of(nhc, struct fib_nh, nh_common);
1316 0 : if (nh->nh_saddr_genid == atomic_read(&net->ipv4.dev_addr_genid))
1317 0 : return nh->nh_saddr;
1318 : }
1319 :
1320 0 : return fib_info_update_nhc_saddr(net, nhc, res->fi->fib_scope);
1321 : }
1322 :
1323 10 : static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc)
1324 : {
1325 10 : if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst ||
1326 : fib_prefsrc != cfg->fc_dst) {
1327 7 : u32 tb_id = cfg->fc_table;
1328 7 : int rc;
1329 :
1330 7 : if (tb_id == RT_TABLE_MAIN)
1331 1 : tb_id = RT_TABLE_LOCAL;
1332 :
1333 7 : rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net,
1334 : fib_prefsrc, tb_id);
1335 :
1336 7 : if (rc != RTN_LOCAL && tb_id != RT_TABLE_LOCAL) {
1337 0 : rc = inet_addr_type_table(cfg->fc_nlinfo.nl_net,
1338 : fib_prefsrc, RT_TABLE_LOCAL);
1339 : }
1340 :
1341 7 : if (rc != RTN_LOCAL)
1342 0 : return false;
1343 : }
1344 : return true;
1345 : }
1346 :
1347 12 : struct fib_info *fib_create_info(struct fib_config *cfg,
1348 : struct netlink_ext_ack *extack)
1349 : {
1350 12 : int err;
1351 12 : struct fib_info *fi = NULL;
1352 12 : struct nexthop *nh = NULL;
1353 12 : struct fib_info *ofi;
1354 12 : int nhs = 1;
1355 12 : struct net *net = cfg->fc_nlinfo.nl_net;
1356 :
1357 12 : if (cfg->fc_type > RTN_MAX)
1358 0 : goto err_inval;
1359 :
1360 : /* Fast check to catch the most weird cases */
1361 12 : if (fib_props[cfg->fc_type].scope > cfg->fc_scope) {
1362 0 : NL_SET_ERR_MSG(extack, "Invalid scope");
1363 0 : goto err_inval;
1364 : }
1365 :
1366 12 : if (cfg->fc_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) {
1367 0 : NL_SET_ERR_MSG(extack,
1368 : "Invalid rtm_flags - can not contain DEAD or LINKDOWN");
1369 0 : goto err_inval;
1370 : }
1371 :
1372 12 : if (cfg->fc_nh_id) {
1373 0 : if (!cfg->fc_mx) {
1374 0 : fi = fib_find_info_nh(net, cfg);
1375 0 : if (fi) {
1376 0 : fi->fib_treeref++;
1377 0 : return fi;
1378 : }
1379 : }
1380 :
1381 0 : nh = nexthop_find_by_id(net, cfg->fc_nh_id);
1382 0 : if (!nh) {
1383 0 : NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
1384 0 : goto err_inval;
1385 : }
1386 : nhs = 0;
1387 : }
1388 :
1389 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
1390 : if (cfg->fc_mp) {
1391 : nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len, extack);
1392 : if (nhs == 0)
1393 : goto err_inval;
1394 : }
1395 : #endif
1396 :
1397 12 : err = -ENOBUFS;
1398 12 : if (fib_info_cnt >= fib_info_hash_size) {
1399 1 : unsigned int new_size = fib_info_hash_size << 1;
1400 1 : struct hlist_head *new_info_hash;
1401 1 : struct hlist_head *new_laddrhash;
1402 1 : unsigned int bytes;
1403 :
1404 1 : if (!new_size)
1405 1 : new_size = 16;
1406 1 : bytes = new_size * sizeof(struct hlist_head *);
1407 1 : new_info_hash = fib_info_hash_alloc(bytes);
1408 1 : new_laddrhash = fib_info_hash_alloc(bytes);
1409 1 : if (!new_info_hash || !new_laddrhash) {
1410 0 : fib_info_hash_free(new_info_hash, bytes);
1411 0 : fib_info_hash_free(new_laddrhash, bytes);
1412 : } else
1413 1 : fib_info_hash_move(new_info_hash, new_laddrhash, new_size);
1414 :
1415 1 : if (!fib_info_hash_size)
1416 0 : goto failure;
1417 : }
1418 :
1419 12 : fi = kzalloc(struct_size(fi, fib_nh, nhs), GFP_KERNEL);
1420 12 : if (!fi)
1421 0 : goto failure;
1422 12 : fi->fib_metrics = ip_fib_metrics_init(fi->fib_net, cfg->fc_mx,
1423 : cfg->fc_mx_len, extack);
1424 12 : if (IS_ERR(fi->fib_metrics)) {
1425 0 : err = PTR_ERR(fi->fib_metrics);
1426 0 : kfree(fi);
1427 0 : return ERR_PTR(err);
1428 : }
1429 :
1430 12 : fib_info_cnt++;
1431 12 : fi->fib_net = net;
1432 12 : fi->fib_protocol = cfg->fc_protocol;
1433 12 : fi->fib_scope = cfg->fc_scope;
1434 12 : fi->fib_flags = cfg->fc_flags;
1435 12 : fi->fib_priority = cfg->fc_priority;
1436 12 : fi->fib_prefsrc = cfg->fc_prefsrc;
1437 12 : fi->fib_type = cfg->fc_type;
1438 12 : fi->fib_tb_id = cfg->fc_table;
1439 :
1440 12 : fi->fib_nhs = nhs;
1441 12 : if (nh) {
1442 0 : if (!nexthop_get(nh)) {
1443 0 : NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
1444 : err = -EINVAL;
1445 : } else {
1446 0 : err = 0;
1447 0 : fi->nh = nh;
1448 : }
1449 : } else {
1450 24 : change_nexthops(fi) {
1451 12 : nexthop_nh->nh_parent = fi;
1452 : } endfor_nexthops(fi)
1453 :
1454 12 : if (cfg->fc_mp)
1455 0 : err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg,
1456 : extack);
1457 : else
1458 12 : err = fib_nh_init(net, fi->fib_nh, cfg, 1, extack);
1459 : }
1460 :
1461 12 : if (err != 0)
1462 0 : goto failure;
1463 :
1464 12 : if (fib_props[cfg->fc_type].error) {
1465 0 : if (cfg->fc_gw_family || cfg->fc_oif || cfg->fc_mp) {
1466 0 : NL_SET_ERR_MSG(extack,
1467 : "Gateway, device and multipath can not be specified for this route type");
1468 0 : goto err_inval;
1469 : }
1470 0 : goto link_it;
1471 : } else {
1472 12 : switch (cfg->fc_type) {
1473 : case RTN_UNICAST:
1474 : case RTN_LOCAL:
1475 : case RTN_BROADCAST:
1476 : case RTN_ANYCAST:
1477 : case RTN_MULTICAST:
1478 12 : break;
1479 0 : default:
1480 0 : NL_SET_ERR_MSG(extack, "Invalid route type");
1481 0 : goto err_inval;
1482 : }
1483 : }
1484 :
1485 12 : if (cfg->fc_scope > RT_SCOPE_HOST) {
1486 0 : NL_SET_ERR_MSG(extack, "Invalid scope");
1487 0 : goto err_inval;
1488 : }
1489 :
1490 12 : if (fi->nh) {
1491 0 : err = fib_check_nexthop(fi->nh, cfg->fc_scope, extack);
1492 0 : if (err)
1493 0 : goto failure;
1494 12 : } else if (cfg->fc_scope == RT_SCOPE_HOST) {
1495 4 : struct fib_nh *nh = fi->fib_nh;
1496 :
1497 : /* Local address is added. */
1498 4 : if (nhs != 1) {
1499 0 : NL_SET_ERR_MSG(extack,
1500 : "Route with host scope can not have multiple nexthops");
1501 0 : goto err_inval;
1502 : }
1503 4 : if (nh->fib_nh_gw_family) {
1504 0 : NL_SET_ERR_MSG(extack,
1505 : "Route with host scope can not have a gateway");
1506 0 : goto err_inval;
1507 : }
1508 4 : nh->fib_nh_scope = RT_SCOPE_NOWHERE;
1509 4 : nh->fib_nh_dev = dev_get_by_index(net, nh->fib_nh_oif);
1510 4 : err = -ENODEV;
1511 4 : if (!nh->fib_nh_dev)
1512 0 : goto failure;
1513 : } else {
1514 8 : int linkdown = 0;
1515 :
1516 16 : change_nexthops(fi) {
1517 16 : err = fib_check_nh(cfg->fc_nlinfo.nl_net, nexthop_nh,
1518 8 : cfg->fc_table, cfg->fc_scope,
1519 : extack);
1520 8 : if (err != 0)
1521 0 : goto failure;
1522 8 : if (nexthop_nh->fib_nh_flags & RTNH_F_LINKDOWN)
1523 0 : linkdown++;
1524 : } endfor_nexthops(fi)
1525 8 : if (linkdown == fi->fib_nhs)
1526 0 : fi->fib_flags |= RTNH_F_LINKDOWN;
1527 : }
1528 :
1529 12 : if (fi->fib_prefsrc && !fib_valid_prefsrc(cfg, fi->fib_prefsrc)) {
1530 0 : NL_SET_ERR_MSG(extack, "Invalid prefsrc address");
1531 0 : goto err_inval;
1532 : }
1533 :
1534 12 : if (!fi->nh) {
1535 24 : change_nexthops(fi) {
1536 12 : fib_info_update_nhc_saddr(net, &nexthop_nh->nh_common,
1537 12 : fi->fib_scope);
1538 12 : if (nexthop_nh->fib_nh_gw_family == AF_INET6)
1539 0 : fi->fib_nh_is_v6 = true;
1540 : } endfor_nexthops(fi)
1541 :
1542 12 : fib_rebalance(fi);
1543 : }
1544 :
1545 12 : link_it:
1546 12 : ofi = fib_find_info(fi);
1547 12 : if (ofi) {
1548 5 : fi->fib_dead = 1;
1549 5 : free_fib_info(fi);
1550 5 : ofi->fib_treeref++;
1551 5 : return ofi;
1552 : }
1553 :
1554 7 : fi->fib_treeref++;
1555 7 : refcount_set(&fi->fib_clntref, 1);
1556 7 : spin_lock_bh(&fib_info_lock);
1557 14 : hlist_add_head(&fi->fib_hash,
1558 7 : &fib_info_hash[fib_info_hashfn(fi)]);
1559 7 : if (fi->fib_prefsrc) {
1560 5 : struct hlist_head *head;
1561 :
1562 5 : head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)];
1563 5 : hlist_add_head(&fi->fib_lhash, head);
1564 : }
1565 7 : if (fi->nh) {
1566 0 : list_add(&fi->nh_list, &nh->fi_list);
1567 : } else {
1568 14 : change_nexthops(fi) {
1569 7 : struct hlist_head *head;
1570 7 : unsigned int hash;
1571 :
1572 7 : if (!nexthop_nh->fib_nh_dev)
1573 0 : continue;
1574 7 : hash = fib_devindex_hashfn(nexthop_nh->fib_nh_dev->ifindex);
1575 7 : head = &fib_info_devhash[hash];
1576 21 : hlist_add_head(&nexthop_nh->nh_hash, head);
1577 : } endfor_nexthops(fi)
1578 : }
1579 7 : spin_unlock_bh(&fib_info_lock);
1580 7 : return fi;
1581 :
1582 : err_inval:
1583 0 : err = -EINVAL;
1584 :
1585 0 : failure:
1586 0 : if (fi) {
1587 0 : fi->fib_dead = 1;
1588 0 : free_fib_info(fi);
1589 : }
1590 :
1591 0 : return ERR_PTR(err);
1592 : }
1593 :
1594 19 : int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc,
1595 : u8 rt_family, unsigned char *flags, bool skip_oif)
1596 : {
1597 19 : if (nhc->nhc_flags & RTNH_F_DEAD)
1598 0 : *flags |= RTNH_F_DEAD;
1599 :
1600 19 : if (nhc->nhc_flags & RTNH_F_LINKDOWN) {
1601 0 : *flags |= RTNH_F_LINKDOWN;
1602 :
1603 0 : rcu_read_lock();
1604 0 : switch (nhc->nhc_family) {
1605 0 : case AF_INET:
1606 0 : if (ip_ignore_linkdown(nhc->nhc_dev))
1607 0 : *flags |= RTNH_F_DEAD;
1608 : break;
1609 0 : case AF_INET6:
1610 0 : if (ip6_ignore_linkdown(nhc->nhc_dev))
1611 0 : *flags |= RTNH_F_DEAD;
1612 : break;
1613 : }
1614 0 : rcu_read_unlock();
1615 : }
1616 :
1617 19 : switch (nhc->nhc_gw_family) {
1618 2 : case AF_INET:
1619 2 : if (nla_put_in_addr(skb, RTA_GATEWAY, nhc->nhc_gw.ipv4))
1620 0 : goto nla_put_failure;
1621 : break;
1622 0 : case AF_INET6:
1623 : /* if gateway family does not match nexthop family
1624 : * gateway is encoded as RTA_VIA
1625 : */
1626 0 : if (rt_family != nhc->nhc_gw_family) {
1627 0 : int alen = sizeof(struct in6_addr);
1628 0 : struct nlattr *nla;
1629 0 : struct rtvia *via;
1630 :
1631 0 : nla = nla_reserve(skb, RTA_VIA, alen + 2);
1632 0 : if (!nla)
1633 0 : goto nla_put_failure;
1634 :
1635 0 : via = nla_data(nla);
1636 0 : via->rtvia_family = AF_INET6;
1637 0 : memcpy(via->rtvia_addr, &nhc->nhc_gw.ipv6, alen);
1638 0 : } else if (nla_put_in6_addr(skb, RTA_GATEWAY,
1639 : &nhc->nhc_gw.ipv6) < 0) {
1640 0 : goto nla_put_failure;
1641 : }
1642 : break;
1643 : }
1644 :
1645 19 : *flags |= (nhc->nhc_flags &
1646 : (RTNH_F_ONLINK | RTNH_F_OFFLOAD | RTNH_F_TRAP));
1647 :
1648 19 : if (!skip_oif && nhc->nhc_dev &&
1649 19 : nla_put_u32(skb, RTA_OIF, nhc->nhc_dev->ifindex))
1650 0 : goto nla_put_failure;
1651 :
1652 19 : if (nhc->nhc_lwtstate &&
1653 19 : lwtunnel_fill_encap(skb, nhc->nhc_lwtstate,
1654 : RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
1655 : goto nla_put_failure;
1656 :
1657 19 : return 0;
1658 :
1659 : nla_put_failure:
1660 : return -EMSGSIZE;
1661 : }
1662 : EXPORT_SYMBOL_GPL(fib_nexthop_info);
1663 :
1664 : #if IS_ENABLED(CONFIG_IP_ROUTE_MULTIPATH) || IS_ENABLED(CONFIG_IPV6)
1665 : int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc,
1666 : int nh_weight, u8 rt_family)
1667 : {
1668 : const struct net_device *dev = nhc->nhc_dev;
1669 : struct rtnexthop *rtnh;
1670 : unsigned char flags = 0;
1671 :
1672 : rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
1673 : if (!rtnh)
1674 : goto nla_put_failure;
1675 :
1676 : rtnh->rtnh_hops = nh_weight - 1;
1677 : rtnh->rtnh_ifindex = dev ? dev->ifindex : 0;
1678 :
1679 : if (fib_nexthop_info(skb, nhc, rt_family, &flags, true) < 0)
1680 : goto nla_put_failure;
1681 :
1682 : rtnh->rtnh_flags = flags;
1683 :
1684 : /* length of rtnetlink header + attributes */
1685 : rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
1686 :
1687 : return 0;
1688 :
1689 : nla_put_failure:
1690 : return -EMSGSIZE;
1691 : }
1692 : EXPORT_SYMBOL_GPL(fib_add_nexthop);
1693 : #endif
1694 :
1695 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
1696 : static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
1697 : {
1698 : struct nlattr *mp;
1699 :
1700 : mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
1701 : if (!mp)
1702 : goto nla_put_failure;
1703 :
1704 : if (unlikely(fi->nh)) {
1705 : if (nexthop_mpath_fill_node(skb, fi->nh, AF_INET) < 0)
1706 : goto nla_put_failure;
1707 : goto mp_end;
1708 : }
1709 :
1710 : for_nexthops(fi) {
1711 : if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight,
1712 : AF_INET) < 0)
1713 : goto nla_put_failure;
1714 : #ifdef CONFIG_IP_ROUTE_CLASSID
1715 : if (nh->nh_tclassid &&
1716 : nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
1717 : goto nla_put_failure;
1718 : #endif
1719 : } endfor_nexthops(fi);
1720 :
1721 : mp_end:
1722 : nla_nest_end(skb, mp);
1723 :
1724 : return 0;
1725 :
1726 : nla_put_failure:
1727 : return -EMSGSIZE;
1728 : }
1729 : #else
1730 : static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
1731 : {
1732 : return 0;
1733 : }
1734 : #endif
1735 :
1736 19 : int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
1737 : const struct fib_rt_info *fri, unsigned int flags)
1738 : {
1739 19 : unsigned int nhs = fib_info_num_path(fri->fi);
1740 19 : struct fib_info *fi = fri->fi;
1741 19 : u32 tb_id = fri->tb_id;
1742 19 : struct nlmsghdr *nlh;
1743 19 : struct rtmsg *rtm;
1744 :
1745 19 : nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
1746 19 : if (!nlh)
1747 : return -EMSGSIZE;
1748 :
1749 19 : rtm = nlmsg_data(nlh);
1750 19 : rtm->rtm_family = AF_INET;
1751 19 : rtm->rtm_dst_len = fri->dst_len;
1752 19 : rtm->rtm_src_len = 0;
1753 19 : rtm->rtm_tos = fri->tos;
1754 19 : if (tb_id < 256)
1755 19 : rtm->rtm_table = tb_id;
1756 : else
1757 0 : rtm->rtm_table = RT_TABLE_COMPAT;
1758 19 : if (nla_put_u32(skb, RTA_TABLE, tb_id))
1759 0 : goto nla_put_failure;
1760 19 : rtm->rtm_type = fri->type;
1761 19 : rtm->rtm_flags = fi->fib_flags;
1762 19 : rtm->rtm_scope = fi->fib_scope;
1763 19 : rtm->rtm_protocol = fi->fib_protocol;
1764 :
1765 19 : if (rtm->rtm_dst_len &&
1766 17 : nla_put_in_addr(skb, RTA_DST, fri->dst))
1767 0 : goto nla_put_failure;
1768 19 : if (fi->fib_priority &&
1769 1 : nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority))
1770 0 : goto nla_put_failure;
1771 19 : if (rtnetlink_put_metrics(skb, fi->fib_metrics->metrics) < 0)
1772 0 : goto nla_put_failure;
1773 :
1774 19 : if (fi->fib_prefsrc &&
1775 16 : nla_put_in_addr(skb, RTA_PREFSRC, fi->fib_prefsrc))
1776 0 : goto nla_put_failure;
1777 :
1778 19 : if (fi->nh) {
1779 0 : if (nla_put_u32(skb, RTA_NH_ID, fi->nh->id))
1780 0 : goto nla_put_failure;
1781 0 : if (nexthop_is_blackhole(fi->nh))
1782 0 : rtm->rtm_type = RTN_BLACKHOLE;
1783 0 : if (!fi->fib_net->ipv4.sysctl_nexthop_compat_mode)
1784 0 : goto offload;
1785 : }
1786 :
1787 19 : if (nhs == 1) {
1788 19 : const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
1789 19 : unsigned char flags = 0;
1790 :
1791 19 : if (fib_nexthop_info(skb, nhc, AF_INET, &flags, false) < 0)
1792 0 : goto nla_put_failure;
1793 :
1794 19 : rtm->rtm_flags = flags;
1795 : #ifdef CONFIG_IP_ROUTE_CLASSID
1796 : if (nhc->nhc_family == AF_INET) {
1797 : struct fib_nh *nh;
1798 :
1799 : nh = container_of(nhc, struct fib_nh, nh_common);
1800 : if (nh->nh_tclassid &&
1801 : nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
1802 : goto nla_put_failure;
1803 : }
1804 : #endif
1805 : } else {
1806 19 : if (fib_add_multipath(skb, fi) < 0)
1807 : goto nla_put_failure;
1808 : }
1809 :
1810 19 : offload:
1811 19 : if (fri->offload)
1812 0 : rtm->rtm_flags |= RTM_F_OFFLOAD;
1813 19 : if (fri->trap)
1814 0 : rtm->rtm_flags |= RTM_F_TRAP;
1815 19 : if (fri->offload_failed)
1816 0 : rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED;
1817 :
1818 19 : nlmsg_end(skb, nlh);
1819 19 : return 0;
1820 :
1821 0 : nla_put_failure:
1822 0 : nlmsg_cancel(skb, nlh);
1823 0 : return -EMSGSIZE;
1824 : }
1825 :
1826 : /*
1827 : * Update FIB if:
1828 : * - local address disappeared -> we must delete all the entries
1829 : * referring to it.
1830 : * - device went down -> we must shutdown all nexthops going via it.
1831 : */
1832 0 : int fib_sync_down_addr(struct net_device *dev, __be32 local)
1833 : {
1834 0 : int ret = 0;
1835 0 : unsigned int hash = fib_laddr_hashfn(local);
1836 0 : struct hlist_head *head = &fib_info_laddrhash[hash];
1837 0 : int tb_id = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN;
1838 0 : struct net *net = dev_net(dev);
1839 0 : struct fib_info *fi;
1840 :
1841 0 : if (!fib_info_laddrhash || local == 0)
1842 : return 0;
1843 :
1844 0 : hlist_for_each_entry(fi, head, fib_lhash) {
1845 0 : if (!net_eq(fi->fib_net, net) ||
1846 0 : fi->fib_tb_id != tb_id)
1847 0 : continue;
1848 0 : if (fi->fib_prefsrc == local) {
1849 0 : fi->fib_flags |= RTNH_F_DEAD;
1850 0 : ret++;
1851 : }
1852 : }
1853 : return ret;
1854 : }
1855 :
1856 0 : static int call_fib_nh_notifiers(struct fib_nh *nh,
1857 : enum fib_event_type event_type)
1858 : {
1859 0 : bool ignore_link_down = ip_ignore_linkdown(nh->fib_nh_dev);
1860 0 : struct fib_nh_notifier_info info = {
1861 : .fib_nh = nh,
1862 : };
1863 :
1864 0 : switch (event_type) {
1865 0 : case FIB_EVENT_NH_ADD:
1866 0 : if (nh->fib_nh_flags & RTNH_F_DEAD)
1867 : break;
1868 0 : if (ignore_link_down && nh->fib_nh_flags & RTNH_F_LINKDOWN)
1869 : break;
1870 0 : return call_fib4_notifiers(dev_net(nh->fib_nh_dev), event_type,
1871 : &info.info);
1872 0 : case FIB_EVENT_NH_DEL:
1873 0 : if ((ignore_link_down && nh->fib_nh_flags & RTNH_F_LINKDOWN) ||
1874 0 : (nh->fib_nh_flags & RTNH_F_DEAD))
1875 0 : return call_fib4_notifiers(dev_net(nh->fib_nh_dev),
1876 : event_type, &info.info);
1877 : default:
1878 : break;
1879 : }
1880 :
1881 0 : return NOTIFY_DONE;
1882 : }
1883 :
1884 : /* Update the PMTU of exceptions when:
1885 : * - the new MTU of the first hop becomes smaller than the PMTU
1886 : * - the old MTU was the same as the PMTU, and it limited discovery of
1887 : * larger MTUs on the path. With that limit raised, we can now
1888 : * discover larger MTUs
1889 : * A special case is locked exceptions, for which the PMTU is smaller
1890 : * than the minimal accepted PMTU:
1891 : * - if the new MTU is greater than the PMTU, don't make any change
1892 : * - otherwise, unlock and set PMTU
1893 : */
1894 0 : void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig)
1895 : {
1896 0 : struct fnhe_hash_bucket *bucket;
1897 0 : int i;
1898 :
1899 0 : bucket = rcu_dereference_protected(nhc->nhc_exceptions, 1);
1900 0 : if (!bucket)
1901 : return;
1902 :
1903 0 : for (i = 0; i < FNHE_HASH_SIZE; i++) {
1904 0 : struct fib_nh_exception *fnhe;
1905 :
1906 0 : for (fnhe = rcu_dereference_protected(bucket[i].chain, 1);
1907 0 : fnhe;
1908 0 : fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1)) {
1909 0 : if (fnhe->fnhe_mtu_locked) {
1910 0 : if (new <= fnhe->fnhe_pmtu) {
1911 0 : fnhe->fnhe_pmtu = new;
1912 0 : fnhe->fnhe_mtu_locked = false;
1913 : }
1914 0 : } else if (new < fnhe->fnhe_pmtu ||
1915 : orig == fnhe->fnhe_pmtu) {
1916 0 : fnhe->fnhe_pmtu = new;
1917 : }
1918 : }
1919 : }
1920 : }
1921 :
1922 0 : void fib_sync_mtu(struct net_device *dev, u32 orig_mtu)
1923 : {
1924 0 : unsigned int hash = fib_devindex_hashfn(dev->ifindex);
1925 0 : struct hlist_head *head = &fib_info_devhash[hash];
1926 0 : struct fib_nh *nh;
1927 :
1928 0 : hlist_for_each_entry(nh, head, nh_hash) {
1929 0 : if (nh->fib_nh_dev == dev)
1930 0 : fib_nhc_update_mtu(&nh->nh_common, dev->mtu, orig_mtu);
1931 : }
1932 0 : }
1933 :
1934 : /* Event force Flags Description
1935 : * NETDEV_CHANGE 0 LINKDOWN Carrier OFF, not for scope host
1936 : * NETDEV_DOWN 0 LINKDOWN|DEAD Link down, not for scope host
1937 : * NETDEV_DOWN 1 LINKDOWN|DEAD Last address removed
1938 : * NETDEV_UNREGISTER 1 LINKDOWN|DEAD Device removed
1939 : *
1940 : * only used when fib_nh is built into fib_info
1941 : */
1942 0 : int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force)
1943 : {
1944 0 : int ret = 0;
1945 0 : int scope = RT_SCOPE_NOWHERE;
1946 0 : struct fib_info *prev_fi = NULL;
1947 0 : unsigned int hash = fib_devindex_hashfn(dev->ifindex);
1948 0 : struct hlist_head *head = &fib_info_devhash[hash];
1949 0 : struct fib_nh *nh;
1950 :
1951 0 : if (force)
1952 0 : scope = -1;
1953 :
1954 0 : hlist_for_each_entry(nh, head, nh_hash) {
1955 0 : struct fib_info *fi = nh->nh_parent;
1956 0 : int dead;
1957 :
1958 0 : BUG_ON(!fi->fib_nhs);
1959 0 : if (nh->fib_nh_dev != dev || fi == prev_fi)
1960 0 : continue;
1961 0 : prev_fi = fi;
1962 0 : dead = 0;
1963 0 : change_nexthops(fi) {
1964 0 : if (nexthop_nh->fib_nh_flags & RTNH_F_DEAD)
1965 0 : dead++;
1966 0 : else if (nexthop_nh->fib_nh_dev == dev &&
1967 0 : nexthop_nh->fib_nh_scope != scope) {
1968 0 : switch (event) {
1969 0 : case NETDEV_DOWN:
1970 : case NETDEV_UNREGISTER:
1971 0 : nexthop_nh->fib_nh_flags |= RTNH_F_DEAD;
1972 0 : fallthrough;
1973 0 : case NETDEV_CHANGE:
1974 0 : nexthop_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
1975 0 : break;
1976 : }
1977 0 : call_fib_nh_notifiers(nexthop_nh,
1978 : FIB_EVENT_NH_DEL);
1979 0 : dead++;
1980 : }
1981 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
1982 : if (event == NETDEV_UNREGISTER &&
1983 : nexthop_nh->fib_nh_dev == dev) {
1984 : dead = fi->fib_nhs;
1985 : break;
1986 : }
1987 : #endif
1988 : } endfor_nexthops(fi)
1989 0 : if (dead == fi->fib_nhs) {
1990 0 : switch (event) {
1991 0 : case NETDEV_DOWN:
1992 : case NETDEV_UNREGISTER:
1993 0 : fi->fib_flags |= RTNH_F_DEAD;
1994 0 : fallthrough;
1995 0 : case NETDEV_CHANGE:
1996 0 : fi->fib_flags |= RTNH_F_LINKDOWN;
1997 0 : break;
1998 : }
1999 0 : ret++;
2000 : }
2001 :
2002 0 : fib_rebalance(fi);
2003 : }
2004 :
2005 0 : return ret;
2006 : }
2007 :
2008 : /* Must be invoked inside of an RCU protected region. */
2009 0 : static void fib_select_default(const struct flowi4 *flp, struct fib_result *res)
2010 : {
2011 0 : struct fib_info *fi = NULL, *last_resort = NULL;
2012 0 : struct hlist_head *fa_head = res->fa_head;
2013 0 : struct fib_table *tb = res->table;
2014 0 : u8 slen = 32 - res->prefixlen;
2015 0 : int order = -1, last_idx = -1;
2016 0 : struct fib_alias *fa, *fa1 = NULL;
2017 0 : u32 last_prio = res->fi->fib_priority;
2018 0 : u8 last_tos = 0;
2019 :
2020 0 : hlist_for_each_entry_rcu(fa, fa_head, fa_list) {
2021 0 : struct fib_info *next_fi = fa->fa_info;
2022 0 : struct fib_nh_common *nhc;
2023 :
2024 0 : if (fa->fa_slen != slen)
2025 0 : continue;
2026 0 : if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
2027 0 : continue;
2028 0 : if (fa->tb_id != tb->tb_id)
2029 0 : continue;
2030 0 : if (next_fi->fib_priority > last_prio &&
2031 : fa->fa_tos == last_tos) {
2032 0 : if (last_tos)
2033 0 : continue;
2034 : break;
2035 : }
2036 0 : if (next_fi->fib_flags & RTNH_F_DEAD)
2037 0 : continue;
2038 0 : last_tos = fa->fa_tos;
2039 0 : last_prio = next_fi->fib_priority;
2040 :
2041 0 : if (next_fi->fib_scope != res->scope ||
2042 0 : fa->fa_type != RTN_UNICAST)
2043 0 : continue;
2044 :
2045 0 : nhc = fib_info_nhc(next_fi, 0);
2046 0 : if (!nhc->nhc_gw_family || nhc->nhc_scope != RT_SCOPE_LINK)
2047 0 : continue;
2048 :
2049 0 : fib_alias_accessed(fa);
2050 :
2051 0 : if (!fi) {
2052 0 : if (next_fi != res->fi)
2053 : break;
2054 : fa1 = fa;
2055 0 : } else if (!fib_detect_death(fi, order, &last_resort,
2056 0 : &last_idx, fa1->fa_default)) {
2057 0 : fib_result_assign(res, fi);
2058 0 : fa1->fa_default = order;
2059 0 : goto out;
2060 : }
2061 0 : fi = next_fi;
2062 0 : order++;
2063 : }
2064 :
2065 0 : if (order <= 0 || !fi) {
2066 0 : if (fa1)
2067 0 : fa1->fa_default = -1;
2068 0 : goto out;
2069 : }
2070 :
2071 0 : if (!fib_detect_death(fi, order, &last_resort, &last_idx,
2072 0 : fa1->fa_default)) {
2073 0 : fib_result_assign(res, fi);
2074 0 : fa1->fa_default = order;
2075 0 : goto out;
2076 : }
2077 :
2078 0 : if (last_idx >= 0)
2079 0 : fib_result_assign(res, last_resort);
2080 0 : fa1->fa_default = last_idx;
2081 0 : out:
2082 0 : return;
2083 : }
2084 :
2085 : /*
2086 : * Dead device goes up. We wake up dead nexthops.
2087 : * It takes sense only on multipath routes.
2088 : *
2089 : * only used when fib_nh is built into fib_info
2090 : */
2091 0 : int fib_sync_up(struct net_device *dev, unsigned char nh_flags)
2092 : {
2093 0 : struct fib_info *prev_fi;
2094 0 : unsigned int hash;
2095 0 : struct hlist_head *head;
2096 0 : struct fib_nh *nh;
2097 0 : int ret;
2098 :
2099 0 : if (!(dev->flags & IFF_UP))
2100 : return 0;
2101 :
2102 0 : if (nh_flags & RTNH_F_DEAD) {
2103 0 : unsigned int flags = dev_get_flags(dev);
2104 :
2105 0 : if (flags & (IFF_RUNNING | IFF_LOWER_UP))
2106 0 : nh_flags |= RTNH_F_LINKDOWN;
2107 : }
2108 :
2109 0 : prev_fi = NULL;
2110 0 : hash = fib_devindex_hashfn(dev->ifindex);
2111 0 : head = &fib_info_devhash[hash];
2112 0 : ret = 0;
2113 :
2114 0 : hlist_for_each_entry(nh, head, nh_hash) {
2115 0 : struct fib_info *fi = nh->nh_parent;
2116 0 : int alive;
2117 :
2118 0 : BUG_ON(!fi->fib_nhs);
2119 0 : if (nh->fib_nh_dev != dev || fi == prev_fi)
2120 0 : continue;
2121 :
2122 0 : prev_fi = fi;
2123 0 : alive = 0;
2124 0 : change_nexthops(fi) {
2125 0 : if (!(nexthop_nh->fib_nh_flags & nh_flags)) {
2126 0 : alive++;
2127 0 : continue;
2128 : }
2129 0 : if (!nexthop_nh->fib_nh_dev ||
2130 0 : !(nexthop_nh->fib_nh_dev->flags & IFF_UP))
2131 0 : continue;
2132 0 : if (nexthop_nh->fib_nh_dev != dev ||
2133 0 : !__in_dev_get_rtnl(dev))
2134 0 : continue;
2135 0 : alive++;
2136 0 : nexthop_nh->fib_nh_flags &= ~nh_flags;
2137 0 : call_fib_nh_notifiers(nexthop_nh, FIB_EVENT_NH_ADD);
2138 : } endfor_nexthops(fi)
2139 :
2140 0 : if (alive > 0) {
2141 0 : fi->fib_flags &= ~nh_flags;
2142 0 : ret++;
2143 : }
2144 :
2145 0 : fib_rebalance(fi);
2146 : }
2147 :
2148 : return ret;
2149 : }
2150 :
2151 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
2152 : static bool fib_good_nh(const struct fib_nh *nh)
2153 : {
2154 : int state = NUD_REACHABLE;
2155 :
2156 : if (nh->fib_nh_scope == RT_SCOPE_LINK) {
2157 : struct neighbour *n;
2158 :
2159 : rcu_read_lock_bh();
2160 :
2161 : if (likely(nh->fib_nh_gw_family == AF_INET))
2162 : n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev,
2163 : (__force u32)nh->fib_nh_gw4);
2164 : else if (nh->fib_nh_gw_family == AF_INET6)
2165 : n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev,
2166 : &nh->fib_nh_gw6);
2167 : else
2168 : n = NULL;
2169 : if (n)
2170 : state = n->nud_state;
2171 :
2172 : rcu_read_unlock_bh();
2173 : }
2174 :
2175 : return !!(state & NUD_VALID);
2176 : }
2177 :
2178 : void fib_select_multipath(struct fib_result *res, int hash)
2179 : {
2180 : struct fib_info *fi = res->fi;
2181 : struct net *net = fi->fib_net;
2182 : bool first = false;
2183 :
2184 : if (unlikely(res->fi->nh)) {
2185 : nexthop_path_fib_result(res, hash);
2186 : return;
2187 : }
2188 :
2189 : change_nexthops(fi) {
2190 : if (net->ipv4.sysctl_fib_multipath_use_neigh) {
2191 : if (!fib_good_nh(nexthop_nh))
2192 : continue;
2193 : if (!first) {
2194 : res->nh_sel = nhsel;
2195 : res->nhc = &nexthop_nh->nh_common;
2196 : first = true;
2197 : }
2198 : }
2199 :
2200 : if (hash > atomic_read(&nexthop_nh->fib_nh_upper_bound))
2201 : continue;
2202 :
2203 : res->nh_sel = nhsel;
2204 : res->nhc = &nexthop_nh->nh_common;
2205 : return;
2206 : } endfor_nexthops(fi);
2207 : }
2208 : #endif
2209 :
2210 26 : void fib_select_path(struct net *net, struct fib_result *res,
2211 : struct flowi4 *fl4, const struct sk_buff *skb)
2212 : {
2213 26 : if (fl4->flowi4_oif && !(fl4->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF))
2214 0 : goto check_saddr;
2215 :
2216 : #ifdef CONFIG_IP_ROUTE_MULTIPATH
2217 : if (fib_info_num_path(res->fi) > 1) {
2218 : int h = fib_multipath_hash(net, fl4, skb, NULL);
2219 :
2220 : fib_select_multipath(res, h);
2221 : }
2222 : else
2223 : #endif
2224 26 : if (!res->prefixlen &&
2225 0 : res->table->tb_num_default > 1 &&
2226 0 : res->type == RTN_UNICAST)
2227 0 : fib_select_default(fl4, res);
2228 :
2229 26 : check_saddr:
2230 26 : if (!fl4->saddr)
2231 7 : fl4->saddr = fib_result_prefsrc(net, res);
2232 26 : }
|
