2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * IPv4 Forwarding Information Base: semantics.
8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
16 #include <linux/uaccess.h>
17 #include <linux/bitops.h>
18 #include <linux/types.h>
19 #include <linux/kernel.h>
20 #include <linux/jiffies.h>
22 #include <linux/string.h>
23 #include <linux/socket.h>
24 #include <linux/sockios.h>
25 #include <linux/errno.h>
27 #include <linux/inet.h>
28 #include <linux/inetdevice.h>
29 #include <linux/netdevice.h>
30 #include <linux/if_arp.h>
31 #include <linux/proc_fs.h>
32 #include <linux/skbuff.h>
33 #include <linux/init.h>
34 #include <linux/slab.h>
35 #include <linux/netlink.h>
39 #include <net/protocol.h>
40 #include <net/route.h>
43 #include <net/ip_fib.h>
44 #include <net/netlink.h>
45 #include <net/nexthop.h>
46 #include <net/lwtunnel.h>
48 #include "fib_lookup.h"
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
;
56 #define DEVINDEX_HASHBITS 8
57 #define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS)
58 static struct hlist_head fib_info_devhash
[DEVINDEX_HASHSIZE
];
60 #ifdef CONFIG_IP_ROUTE_MULTIPATH
62 #define for_nexthops(fi) { \
63 int nhsel; const struct fib_nh *nh; \
64 for (nhsel = 0, nh = (fi)->fib_nh; \
65 nhsel < (fi)->fib_nhs; \
68 #define change_nexthops(fi) { \
69 int nhsel; struct fib_nh *nexthop_nh; \
70 for (nhsel = 0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
71 nhsel < (fi)->fib_nhs; \
72 nexthop_nh++, nhsel++)
74 #else /* CONFIG_IP_ROUTE_MULTIPATH */
76 /* Hope, that gcc will optimize it to get rid of dummy loop */
78 #define for_nexthops(fi) { \
79 int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \
80 for (nhsel = 0; nhsel < 1; nhsel++)
82 #define change_nexthops(fi) { \
84 struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
85 for (nhsel = 0; nhsel < 1; nhsel++)
87 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
89 #define endfor_nexthops(fi) }
92 const struct fib_prop fib_props
[RTN_MAX
+ 1] = {
95 .scope
= RT_SCOPE_NOWHERE
,
99 .scope
= RT_SCOPE_UNIVERSE
,
103 .scope
= RT_SCOPE_HOST
,
107 .scope
= RT_SCOPE_LINK
,
111 .scope
= RT_SCOPE_LINK
,
115 .scope
= RT_SCOPE_UNIVERSE
,
119 .scope
= RT_SCOPE_UNIVERSE
,
121 [RTN_UNREACHABLE
] = {
122 .error
= -EHOSTUNREACH
,
123 .scope
= RT_SCOPE_UNIVERSE
,
127 .scope
= RT_SCOPE_UNIVERSE
,
131 .scope
= RT_SCOPE_UNIVERSE
,
135 .scope
= RT_SCOPE_NOWHERE
,
139 .scope
= RT_SCOPE_NOWHERE
,
143 static void rt_fibinfo_free(struct rtable __rcu
**rtp
)
145 struct rtable
*rt
= rcu_dereference_protected(*rtp
, 1);
150 /* Not even needed : RCU_INIT_POINTER(*rtp, NULL);
151 * because we waited an RCU grace period before calling
152 * free_fib_info_rcu()
155 dst_dev_put(&rt
->dst
);
156 dst_release_immediate(&rt
->dst
);
159 static void free_nh_exceptions(struct fib_nh
*nh
)
161 struct fnhe_hash_bucket
*hash
;
164 hash
= rcu_dereference_protected(nh
->nh_exceptions
, 1);
167 for (i
= 0; i
< FNHE_HASH_SIZE
; i
++) {
168 struct fib_nh_exception
*fnhe
;
170 fnhe
= rcu_dereference_protected(hash
[i
].chain
, 1);
172 struct fib_nh_exception
*next
;
174 next
= rcu_dereference_protected(fnhe
->fnhe_next
, 1);
176 rt_fibinfo_free(&fnhe
->fnhe_rth_input
);
177 rt_fibinfo_free(&fnhe
->fnhe_rth_output
);
187 static void rt_fibinfo_free_cpus(struct rtable __rcu
* __percpu
*rtp
)
194 for_each_possible_cpu(cpu
) {
197 rt
= rcu_dereference_protected(*per_cpu_ptr(rtp
, cpu
), 1);
199 dst_dev_put(&rt
->dst
);
200 dst_release_immediate(&rt
->dst
);
206 /* Release a nexthop info record */
207 static void free_fib_info_rcu(struct rcu_head
*head
)
209 struct fib_info
*fi
= container_of(head
, struct fib_info
, rcu
);
210 struct dst_metrics
*m
;
212 change_nexthops(fi
) {
213 if (nexthop_nh
->nh_dev
)
214 dev_put(nexthop_nh
->nh_dev
);
215 lwtstate_put(nexthop_nh
->nh_lwtstate
);
216 free_nh_exceptions(nexthop_nh
);
217 rt_fibinfo_free_cpus(nexthop_nh
->nh_pcpu_rth_output
);
218 rt_fibinfo_free(&nexthop_nh
->nh_rth_input
);
219 } endfor_nexthops(fi
);
222 if (m
!= &dst_default_metrics
&& atomic_dec_and_test(&m
->refcnt
))
227 void free_fib_info(struct fib_info
*fi
)
229 if (fi
->fib_dead
== 0) {
230 pr_warn("Freeing alive fib_info %p\n", fi
);
234 #ifdef CONFIG_IP_ROUTE_CLASSID
235 change_nexthops(fi
) {
236 if (nexthop_nh
->nh_tclassid
)
237 fi
->fib_net
->ipv4
.fib_num_tclassid_users
--;
238 } endfor_nexthops(fi
);
240 call_rcu(&fi
->rcu
, free_fib_info_rcu
);
242 EXPORT_SYMBOL_GPL(free_fib_info
);
244 void fib_release_info(struct fib_info
*fi
)
246 spin_lock_bh(&fib_info_lock
);
247 if (fi
&& --fi
->fib_treeref
== 0) {
248 hlist_del(&fi
->fib_hash
);
250 hlist_del(&fi
->fib_lhash
);
251 change_nexthops(fi
) {
252 if (!nexthop_nh
->nh_dev
)
254 hlist_del(&nexthop_nh
->nh_hash
);
255 } endfor_nexthops(fi
)
259 spin_unlock_bh(&fib_info_lock
);
262 static inline int nh_comp(const struct fib_info
*fi
, const struct fib_info
*ofi
)
264 const struct fib_nh
*onh
= ofi
->fib_nh
;
267 if (nh
->nh_oif
!= onh
->nh_oif
||
268 nh
->nh_gw
!= onh
->nh_gw
||
269 nh
->nh_scope
!= onh
->nh_scope
||
270 #ifdef CONFIG_IP_ROUTE_MULTIPATH
271 nh
->nh_weight
!= onh
->nh_weight
||
273 #ifdef CONFIG_IP_ROUTE_CLASSID
274 nh
->nh_tclassid
!= onh
->nh_tclassid
||
276 lwtunnel_cmp_encap(nh
->nh_lwtstate
, onh
->nh_lwtstate
) ||
277 ((nh
->nh_flags
^ onh
->nh_flags
) & ~RTNH_COMPARE_MASK
))
280 } endfor_nexthops(fi
);
284 static inline unsigned int fib_devindex_hashfn(unsigned int val
)
286 unsigned int mask
= DEVINDEX_HASHSIZE
- 1;
289 (val
>> DEVINDEX_HASHBITS
) ^
290 (val
>> (DEVINDEX_HASHBITS
* 2))) & mask
;
293 static inline unsigned int fib_info_hashfn(const struct fib_info
*fi
)
295 unsigned int mask
= (fib_info_hash_size
- 1);
296 unsigned int val
= fi
->fib_nhs
;
298 val
^= (fi
->fib_protocol
<< 8) | fi
->fib_scope
;
299 val
^= (__force u32
)fi
->fib_prefsrc
;
300 val
^= fi
->fib_priority
;
302 val
^= fib_devindex_hashfn(nh
->nh_oif
);
303 } endfor_nexthops(fi
)
305 return (val
^ (val
>> 7) ^ (val
>> 12)) & mask
;
308 static struct fib_info
*fib_find_info(const struct fib_info
*nfi
)
310 struct hlist_head
*head
;
314 hash
= fib_info_hashfn(nfi
);
315 head
= &fib_info_hash
[hash
];
317 hlist_for_each_entry(fi
, head
, fib_hash
) {
318 if (!net_eq(fi
->fib_net
, nfi
->fib_net
))
320 if (fi
->fib_nhs
!= nfi
->fib_nhs
)
322 if (nfi
->fib_protocol
== fi
->fib_protocol
&&
323 nfi
->fib_scope
== fi
->fib_scope
&&
324 nfi
->fib_prefsrc
== fi
->fib_prefsrc
&&
325 nfi
->fib_priority
== fi
->fib_priority
&&
326 nfi
->fib_type
== fi
->fib_type
&&
327 memcmp(nfi
->fib_metrics
, fi
->fib_metrics
,
328 sizeof(u32
) * RTAX_MAX
) == 0 &&
329 !((nfi
->fib_flags
^ fi
->fib_flags
) & ~RTNH_COMPARE_MASK
) &&
330 (nfi
->fib_nhs
== 0 || nh_comp(fi
, nfi
) == 0))
337 /* Check, that the gateway is already configured.
338 * Used only by redirect accept routine.
340 int ip_fib_check_default(__be32 gw
, struct net_device
*dev
)
342 struct hlist_head
*head
;
346 spin_lock(&fib_info_lock
);
348 hash
= fib_devindex_hashfn(dev
->ifindex
);
349 head
= &fib_info_devhash
[hash
];
350 hlist_for_each_entry(nh
, head
, nh_hash
) {
351 if (nh
->nh_dev
== dev
&&
353 !(nh
->nh_flags
& RTNH_F_DEAD
)) {
354 spin_unlock(&fib_info_lock
);
359 spin_unlock(&fib_info_lock
);
364 static inline size_t fib_nlmsg_size(struct fib_info
*fi
)
366 size_t payload
= NLMSG_ALIGN(sizeof(struct rtmsg
))
367 + nla_total_size(4) /* RTA_TABLE */
368 + nla_total_size(4) /* RTA_DST */
369 + nla_total_size(4) /* RTA_PRIORITY */
370 + nla_total_size(4) /* RTA_PREFSRC */
371 + nla_total_size(TCP_CA_NAME_MAX
); /* RTAX_CC_ALGO */
373 /* space for nested metrics */
374 payload
+= nla_total_size((RTAX_MAX
* nla_total_size(4)));
377 size_t nh_encapsize
= 0;
378 /* Also handles the special case fib_nhs == 1 */
380 /* each nexthop is packed in an attribute */
381 size_t nhsize
= nla_total_size(sizeof(struct rtnexthop
));
383 /* may contain flow and gateway attribute */
384 nhsize
+= 2 * nla_total_size(4);
386 /* grab encap info */
388 if (nh
->nh_lwtstate
) {
390 nh_encapsize
+= lwtunnel_get_encap_size(
393 nh_encapsize
+= nla_total_size(2);
395 } endfor_nexthops(fi
);
397 /* all nexthops are packed in a nested attribute */
398 payload
+= nla_total_size((fi
->fib_nhs
* nhsize
) +
406 void rtmsg_fib(int event
, __be32 key
, struct fib_alias
*fa
,
407 int dst_len
, u32 tb_id
, const struct nl_info
*info
,
408 unsigned int nlm_flags
)
411 u32 seq
= info
->nlh
? info
->nlh
->nlmsg_seq
: 0;
414 skb
= nlmsg_new(fib_nlmsg_size(fa
->fa_info
), GFP_KERNEL
);
418 err
= fib_dump_info(skb
, info
->portid
, seq
, event
, tb_id
,
419 fa
->fa_type
, key
, dst_len
,
420 fa
->fa_tos
, fa
->fa_info
, nlm_flags
);
422 /* -EMSGSIZE implies BUG in fib_nlmsg_size() */
423 WARN_ON(err
== -EMSGSIZE
);
427 rtnl_notify(skb
, info
->nl_net
, info
->portid
, RTNLGRP_IPV4_ROUTE
,
428 info
->nlh
, GFP_KERNEL
);
432 rtnl_set_sk_err(info
->nl_net
, RTNLGRP_IPV4_ROUTE
, err
);
435 static int fib_detect_death(struct fib_info
*fi
, int order
,
436 struct fib_info
**last_resort
, int *last_idx
,
440 int state
= NUD_NONE
;
442 n
= neigh_lookup(&arp_tbl
, &fi
->fib_nh
[0].nh_gw
, fi
->fib_dev
);
444 state
= n
->nud_state
;
449 if (state
== NUD_REACHABLE
)
451 if ((state
& NUD_VALID
) && order
!= dflt
)
453 if ((state
& NUD_VALID
) ||
454 (*last_idx
< 0 && order
> dflt
&& state
!= NUD_INCOMPLETE
)) {
461 #ifdef CONFIG_IP_ROUTE_MULTIPATH
463 static int fib_count_nexthops(struct rtnexthop
*rtnh
, int remaining
,
464 struct netlink_ext_ack
*extack
)
468 while (rtnh_ok(rtnh
, remaining
)) {
470 rtnh
= rtnh_next(rtnh
, &remaining
);
473 /* leftover implies invalid nexthop configuration, discard it */
475 NL_SET_ERR_MSG(extack
,
476 "Invalid nexthop configuration - extra data after nexthops");
483 static int fib_get_nhs(struct fib_info
*fi
, struct rtnexthop
*rtnh
,
484 int remaining
, struct fib_config
*cfg
,
485 struct netlink_ext_ack
*extack
)
489 change_nexthops(fi
) {
492 if (!rtnh_ok(rtnh
, remaining
)) {
493 NL_SET_ERR_MSG(extack
,
494 "Invalid nexthop configuration - extra data after nexthop");
498 if (rtnh
->rtnh_flags
& (RTNH_F_DEAD
| RTNH_F_LINKDOWN
)) {
499 NL_SET_ERR_MSG(extack
,
500 "Invalid flags for nexthop - can not contain DEAD or LINKDOWN");
504 nexthop_nh
->nh_flags
=
505 (cfg
->fc_flags
& ~0xFF) | rtnh
->rtnh_flags
;
506 nexthop_nh
->nh_oif
= rtnh
->rtnh_ifindex
;
507 nexthop_nh
->nh_weight
= rtnh
->rtnh_hops
+ 1;
509 attrlen
= rtnh_attrlen(rtnh
);
511 struct nlattr
*nla
, *attrs
= rtnh_attrs(rtnh
);
513 nla
= nla_find(attrs
, attrlen
, RTA_GATEWAY
);
514 nexthop_nh
->nh_gw
= nla
? nla_get_in_addr(nla
) : 0;
515 #ifdef CONFIG_IP_ROUTE_CLASSID
516 nla
= nla_find(attrs
, attrlen
, RTA_FLOW
);
517 nexthop_nh
->nh_tclassid
= nla
? nla_get_u32(nla
) : 0;
518 if (nexthop_nh
->nh_tclassid
)
519 fi
->fib_net
->ipv4
.fib_num_tclassid_users
++;
521 nla
= nla_find(attrs
, attrlen
, RTA_ENCAP
);
523 struct lwtunnel_state
*lwtstate
;
524 struct nlattr
*nla_entype
;
526 nla_entype
= nla_find(attrs
, attrlen
,
529 NL_SET_BAD_ATTR(extack
, nla
);
530 NL_SET_ERR_MSG(extack
,
531 "Encap type is missing");
535 ret
= lwtunnel_build_state(nla_get_u16(
541 nexthop_nh
->nh_lwtstate
=
542 lwtstate_get(lwtstate
);
546 rtnh
= rtnh_next(rtnh
, &remaining
);
547 } endfor_nexthops(fi
);
558 static void fib_rebalance(struct fib_info
*fi
)
562 struct in_device
*in_dev
;
569 if (nh
->nh_flags
& RTNH_F_DEAD
)
572 in_dev
= __in_dev_get_rtnl(nh
->nh_dev
);
575 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
) &&
576 nh
->nh_flags
& RTNH_F_LINKDOWN
)
579 total
+= nh
->nh_weight
;
580 } endfor_nexthops(fi
);
583 change_nexthops(fi
) {
586 in_dev
= __in_dev_get_rtnl(nexthop_nh
->nh_dev
);
588 if (nexthop_nh
->nh_flags
& RTNH_F_DEAD
) {
591 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
) &&
592 nexthop_nh
->nh_flags
& RTNH_F_LINKDOWN
) {
595 w
+= nexthop_nh
->nh_weight
;
596 upper_bound
= DIV_ROUND_CLOSEST_ULL((u64
)w
<< 31,
600 atomic_set(&nexthop_nh
->nh_upper_bound
, upper_bound
);
601 } endfor_nexthops(fi
);
604 static inline void fib_add_weight(struct fib_info
*fi
,
605 const struct fib_nh
*nh
)
607 fi
->fib_weight
+= nh
->nh_weight
;
610 #else /* CONFIG_IP_ROUTE_MULTIPATH */
612 #define fib_rebalance(fi) do { } while (0)
613 #define fib_add_weight(fi, nh) do { } while (0)
615 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
617 static int fib_encap_match(u16 encap_type
,
618 struct nlattr
*encap
,
619 const struct fib_nh
*nh
,
620 const struct fib_config
*cfg
,
621 struct netlink_ext_ack
*extack
)
623 struct lwtunnel_state
*lwtstate
;
626 if (encap_type
== LWTUNNEL_ENCAP_NONE
)
629 ret
= lwtunnel_build_state(encap_type
, encap
, AF_INET
,
630 cfg
, &lwtstate
, extack
);
632 result
= lwtunnel_cmp_encap(lwtstate
, nh
->nh_lwtstate
);
633 lwtstate_free(lwtstate
);
639 int fib_nh_match(struct fib_config
*cfg
, struct fib_info
*fi
,
640 struct netlink_ext_ack
*extack
)
642 #ifdef CONFIG_IP_ROUTE_MULTIPATH
643 struct rtnexthop
*rtnh
;
647 if (cfg
->fc_priority
&& cfg
->fc_priority
!= fi
->fib_priority
)
650 if (cfg
->fc_oif
|| cfg
->fc_gw
) {
652 if (fib_encap_match(cfg
->fc_encap_type
, cfg
->fc_encap
,
653 fi
->fib_nh
, cfg
, extack
))
656 if ((!cfg
->fc_oif
|| cfg
->fc_oif
== fi
->fib_nh
->nh_oif
) &&
657 (!cfg
->fc_gw
|| cfg
->fc_gw
== fi
->fib_nh
->nh_gw
))
662 #ifdef CONFIG_IP_ROUTE_MULTIPATH
667 remaining
= cfg
->fc_mp_len
;
672 if (!rtnh_ok(rtnh
, remaining
))
675 if (rtnh
->rtnh_ifindex
&& rtnh
->rtnh_ifindex
!= nh
->nh_oif
)
678 attrlen
= rtnh_attrlen(rtnh
);
680 struct nlattr
*nla
, *attrs
= rtnh_attrs(rtnh
);
682 nla
= nla_find(attrs
, attrlen
, RTA_GATEWAY
);
683 if (nla
&& nla_get_in_addr(nla
) != nh
->nh_gw
)
685 #ifdef CONFIG_IP_ROUTE_CLASSID
686 nla
= nla_find(attrs
, attrlen
, RTA_FLOW
);
687 if (nla
&& nla_get_u32(nla
) != nh
->nh_tclassid
)
692 rtnh
= rtnh_next(rtnh
, &remaining
);
693 } endfor_nexthops(fi
);
703 * Semantics of nexthop is very messy by historical reasons.
704 * We have to take into account, that:
705 * a) gateway can be actually local interface address,
706 * so that gatewayed route is direct.
707 * b) gateway must be on-link address, possibly
708 * described not by an ifaddr, but also by a direct route.
709 * c) If both gateway and interface are specified, they should not
711 * d) If we use tunnel routes, gateway could be not on-link.
713 * Attempt to reconcile all of these (alas, self-contradictory) conditions
714 * results in pretty ugly and hairy code with obscure logic.
716 * I chose to generalized it instead, so that the size
717 * of code does not increase practically, but it becomes
719 * Every prefix is assigned a "scope" value: "host" is local address,
720 * "link" is direct route,
721 * [ ... "site" ... "interior" ... ]
722 * and "universe" is true gateway route with global meaning.
724 * Every prefix refers to a set of "nexthop"s (gw, oif),
725 * where gw must have narrower scope. This recursion stops
726 * when gw has LOCAL scope or if "nexthop" is declared ONLINK,
727 * which means that gw is forced to be on link.
729 * Code is still hairy, but now it is apparently logically
730 * consistent and very flexible. F.e. as by-product it allows
731 * to co-exists in peace independent exterior and interior
734 * Normally it looks as following.
736 * {universe prefix} -> (gw, oif) [scope link]
738 * |-> {link prefix} -> (gw, oif) [scope local]
740 * |-> {local prefix} (terminal node)
742 static int fib_check_nh(struct fib_config
*cfg
, struct fib_info
*fi
,
743 struct fib_nh
*nh
, struct netlink_ext_ack
*extack
)
747 struct net_device
*dev
;
749 net
= cfg
->fc_nlinfo
.nl_net
;
751 struct fib_result res
;
753 if (nh
->nh_flags
& RTNH_F_ONLINK
) {
754 unsigned int addr_type
;
756 if (cfg
->fc_scope
>= RT_SCOPE_LINK
) {
757 NL_SET_ERR_MSG(extack
,
758 "Nexthop has invalid scope");
761 dev
= __dev_get_by_index(net
, nh
->nh_oif
);
764 if (!(dev
->flags
& IFF_UP
)) {
765 NL_SET_ERR_MSG(extack
,
766 "Nexthop device is not up");
769 addr_type
= inet_addr_type_dev_table(net
, dev
, nh
->nh_gw
);
770 if (addr_type
!= RTN_UNICAST
) {
771 NL_SET_ERR_MSG(extack
,
772 "Nexthop has invalid gateway");
775 if (!netif_carrier_ok(dev
))
776 nh
->nh_flags
|= RTNH_F_LINKDOWN
;
779 nh
->nh_scope
= RT_SCOPE_LINK
;
784 struct fib_table
*tbl
= NULL
;
785 struct flowi4 fl4
= {
787 .flowi4_scope
= cfg
->fc_scope
+ 1,
788 .flowi4_oif
= nh
->nh_oif
,
789 .flowi4_iif
= LOOPBACK_IFINDEX
,
792 /* It is not necessary, but requires a bit of thinking */
793 if (fl4
.flowi4_scope
< RT_SCOPE_LINK
)
794 fl4
.flowi4_scope
= RT_SCOPE_LINK
;
797 tbl
= fib_get_table(net
, cfg
->fc_table
);
800 err
= fib_table_lookup(tbl
, &fl4
, &res
,
801 FIB_LOOKUP_IGNORE_LINKSTATE
|
804 /* on error or if no table given do full lookup. This
805 * is needed for example when nexthops are in the local
806 * table rather than the given table
809 err
= fib_lookup(net
, &fl4
, &res
,
810 FIB_LOOKUP_IGNORE_LINKSTATE
);
814 NL_SET_ERR_MSG(extack
,
815 "Nexthop has invalid gateway");
821 if (res
.type
!= RTN_UNICAST
&& res
.type
!= RTN_LOCAL
) {
822 NL_SET_ERR_MSG(extack
, "Nexthop has invalid gateway");
825 nh
->nh_scope
= res
.scope
;
826 nh
->nh_oif
= FIB_RES_OIF(res
);
827 nh
->nh_dev
= dev
= FIB_RES_DEV(res
);
829 NL_SET_ERR_MSG(extack
,
830 "No egress device for nexthop gateway");
834 if (!netif_carrier_ok(dev
))
835 nh
->nh_flags
|= RTNH_F_LINKDOWN
;
836 err
= (dev
->flags
& IFF_UP
) ? 0 : -ENETDOWN
;
838 struct in_device
*in_dev
;
840 if (nh
->nh_flags
& (RTNH_F_PERVASIVE
| RTNH_F_ONLINK
)) {
841 NL_SET_ERR_MSG(extack
,
842 "Invalid flags for nexthop - PERVASIVE and ONLINK can not be set");
847 in_dev
= inetdev_by_index(net
, nh
->nh_oif
);
851 if (!(in_dev
->dev
->flags
& IFF_UP
)) {
852 NL_SET_ERR_MSG(extack
, "Device for nexthop is not up");
855 nh
->nh_dev
= in_dev
->dev
;
856 dev_hold(nh
->nh_dev
);
857 nh
->nh_scope
= RT_SCOPE_HOST
;
858 if (!netif_carrier_ok(nh
->nh_dev
))
859 nh
->nh_flags
|= RTNH_F_LINKDOWN
;
867 static inline unsigned int fib_laddr_hashfn(__be32 val
)
869 unsigned int mask
= (fib_info_hash_size
- 1);
871 return ((__force u32
)val
^
872 ((__force u32
)val
>> 7) ^
873 ((__force u32
)val
>> 14)) & mask
;
876 static struct hlist_head
*fib_info_hash_alloc(int bytes
)
878 if (bytes
<= PAGE_SIZE
)
879 return kzalloc(bytes
, GFP_KERNEL
);
881 return (struct hlist_head
*)
882 __get_free_pages(GFP_KERNEL
| __GFP_ZERO
,
886 static void fib_info_hash_free(struct hlist_head
*hash
, int bytes
)
891 if (bytes
<= PAGE_SIZE
)
894 free_pages((unsigned long) hash
, get_order(bytes
));
897 static void fib_info_hash_move(struct hlist_head
*new_info_hash
,
898 struct hlist_head
*new_laddrhash
,
899 unsigned int new_size
)
901 struct hlist_head
*old_info_hash
, *old_laddrhash
;
902 unsigned int old_size
= fib_info_hash_size
;
903 unsigned int i
, bytes
;
905 spin_lock_bh(&fib_info_lock
);
906 old_info_hash
= fib_info_hash
;
907 old_laddrhash
= fib_info_laddrhash
;
908 fib_info_hash_size
= new_size
;
910 for (i
= 0; i
< old_size
; i
++) {
911 struct hlist_head
*head
= &fib_info_hash
[i
];
912 struct hlist_node
*n
;
915 hlist_for_each_entry_safe(fi
, n
, head
, fib_hash
) {
916 struct hlist_head
*dest
;
917 unsigned int new_hash
;
919 new_hash
= fib_info_hashfn(fi
);
920 dest
= &new_info_hash
[new_hash
];
921 hlist_add_head(&fi
->fib_hash
, dest
);
924 fib_info_hash
= new_info_hash
;
926 for (i
= 0; i
< old_size
; i
++) {
927 struct hlist_head
*lhead
= &fib_info_laddrhash
[i
];
928 struct hlist_node
*n
;
931 hlist_for_each_entry_safe(fi
, n
, lhead
, fib_lhash
) {
932 struct hlist_head
*ldest
;
933 unsigned int new_hash
;
935 new_hash
= fib_laddr_hashfn(fi
->fib_prefsrc
);
936 ldest
= &new_laddrhash
[new_hash
];
937 hlist_add_head(&fi
->fib_lhash
, ldest
);
940 fib_info_laddrhash
= new_laddrhash
;
942 spin_unlock_bh(&fib_info_lock
);
944 bytes
= old_size
* sizeof(struct hlist_head
*);
945 fib_info_hash_free(old_info_hash
, bytes
);
946 fib_info_hash_free(old_laddrhash
, bytes
);
949 __be32
fib_info_update_nh_saddr(struct net
*net
, struct fib_nh
*nh
)
951 nh
->nh_saddr
= inet_select_addr(nh
->nh_dev
,
953 nh
->nh_parent
->fib_scope
);
954 nh
->nh_saddr_genid
= atomic_read(&net
->ipv4
.dev_addr_genid
);
959 static bool fib_valid_prefsrc(struct fib_config
*cfg
, __be32 fib_prefsrc
)
961 if (cfg
->fc_type
!= RTN_LOCAL
|| !cfg
->fc_dst
||
962 fib_prefsrc
!= cfg
->fc_dst
) {
963 u32 tb_id
= cfg
->fc_table
;
966 if (tb_id
== RT_TABLE_MAIN
)
967 tb_id
= RT_TABLE_LOCAL
;
969 rc
= inet_addr_type_table(cfg
->fc_nlinfo
.nl_net
,
972 if (rc
!= RTN_LOCAL
&& tb_id
!= RT_TABLE_LOCAL
) {
973 rc
= inet_addr_type_table(cfg
->fc_nlinfo
.nl_net
,
974 fib_prefsrc
, RT_TABLE_LOCAL
);
984 fib_convert_metrics(struct fib_info
*fi
, const struct fib_config
*cfg
)
993 nla_for_each_attr(nla
, cfg
->fc_mx
, cfg
->fc_mx_len
, remaining
) {
994 int type
= nla_type(nla
);
1002 if (type
== RTAX_CC_ALGO
) {
1003 char tmp
[TCP_CA_NAME_MAX
];
1005 nla_strlcpy(tmp
, nla
, sizeof(tmp
));
1006 val
= tcp_ca_get_key_by_name(tmp
, &ecn_ca
);
1007 if (val
== TCP_CA_UNSPEC
)
1010 val
= nla_get_u32(nla
);
1012 if (type
== RTAX_ADVMSS
&& val
> 65535 - 40)
1014 if (type
== RTAX_MTU
&& val
> 65535 - 15)
1016 if (type
== RTAX_HOPLIMIT
&& val
> 255)
1018 if (type
== RTAX_FEATURES
&& (val
& ~RTAX_FEATURE_MASK
))
1020 fi
->fib_metrics
->metrics
[type
- 1] = val
;
1024 fi
->fib_metrics
->metrics
[RTAX_FEATURES
- 1] |= DST_FEATURE_ECN_CA
;
1029 struct fib_info
*fib_create_info(struct fib_config
*cfg
,
1030 struct netlink_ext_ack
*extack
)
1033 struct fib_info
*fi
= NULL
;
1034 struct fib_info
*ofi
;
1036 struct net
*net
= cfg
->fc_nlinfo
.nl_net
;
1038 if (cfg
->fc_type
> RTN_MAX
)
1041 /* Fast check to catch the most weird cases */
1042 if (fib_props
[cfg
->fc_type
].scope
> cfg
->fc_scope
) {
1043 NL_SET_ERR_MSG(extack
, "Invalid scope");
1047 if (cfg
->fc_flags
& (RTNH_F_DEAD
| RTNH_F_LINKDOWN
)) {
1048 NL_SET_ERR_MSG(extack
,
1049 "Invalid rtm_flags - can not contain DEAD or LINKDOWN");
1053 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1055 nhs
= fib_count_nexthops(cfg
->fc_mp
, cfg
->fc_mp_len
, extack
);
1062 if (fib_info_cnt
>= fib_info_hash_size
) {
1063 unsigned int new_size
= fib_info_hash_size
<< 1;
1064 struct hlist_head
*new_info_hash
;
1065 struct hlist_head
*new_laddrhash
;
1070 bytes
= new_size
* sizeof(struct hlist_head
*);
1071 new_info_hash
= fib_info_hash_alloc(bytes
);
1072 new_laddrhash
= fib_info_hash_alloc(bytes
);
1073 if (!new_info_hash
|| !new_laddrhash
) {
1074 fib_info_hash_free(new_info_hash
, bytes
);
1075 fib_info_hash_free(new_laddrhash
, bytes
);
1077 fib_info_hash_move(new_info_hash
, new_laddrhash
, new_size
);
1079 if (!fib_info_hash_size
)
1083 fi
= kzalloc(sizeof(*fi
)+nhs
*sizeof(struct fib_nh
), GFP_KERNEL
);
1088 fi
->fib_metrics
= kzalloc(sizeof(*fi
->fib_metrics
), GFP_KERNEL
);
1089 if (!fi
->fib_metrics
)
1091 atomic_set(&fi
->fib_metrics
->refcnt
, 1);
1093 fi
->fib_metrics
= (struct dst_metrics
*)&dst_default_metrics
;
1096 fi
->fib_protocol
= cfg
->fc_protocol
;
1097 fi
->fib_scope
= cfg
->fc_scope
;
1098 fi
->fib_flags
= cfg
->fc_flags
;
1099 fi
->fib_priority
= cfg
->fc_priority
;
1100 fi
->fib_prefsrc
= cfg
->fc_prefsrc
;
1101 fi
->fib_type
= cfg
->fc_type
;
1102 fi
->fib_tb_id
= cfg
->fc_table
;
1105 change_nexthops(fi
) {
1106 nexthop_nh
->nh_parent
= fi
;
1107 nexthop_nh
->nh_pcpu_rth_output
= alloc_percpu(struct rtable __rcu
*);
1108 if (!nexthop_nh
->nh_pcpu_rth_output
)
1110 } endfor_nexthops(fi
)
1112 err
= fib_convert_metrics(fi
, cfg
);
1117 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1118 err
= fib_get_nhs(fi
, cfg
->fc_mp
, cfg
->fc_mp_len
, cfg
, extack
);
1121 if (cfg
->fc_oif
&& fi
->fib_nh
->nh_oif
!= cfg
->fc_oif
) {
1122 NL_SET_ERR_MSG(extack
,
1123 "Nexthop device index does not match RTA_OIF");
1126 if (cfg
->fc_gw
&& fi
->fib_nh
->nh_gw
!= cfg
->fc_gw
) {
1127 NL_SET_ERR_MSG(extack
,
1128 "Nexthop gateway does not match RTA_GATEWAY");
1131 #ifdef CONFIG_IP_ROUTE_CLASSID
1132 if (cfg
->fc_flow
&& fi
->fib_nh
->nh_tclassid
!= cfg
->fc_flow
) {
1133 NL_SET_ERR_MSG(extack
,
1134 "Nexthop class id does not match RTA_FLOW");
1139 NL_SET_ERR_MSG(extack
,
1140 "Multipath support not enabled in kernel");
1144 struct fib_nh
*nh
= fi
->fib_nh
;
1146 if (cfg
->fc_encap
) {
1147 struct lwtunnel_state
*lwtstate
;
1149 if (cfg
->fc_encap_type
== LWTUNNEL_ENCAP_NONE
) {
1150 NL_SET_ERR_MSG(extack
,
1151 "LWT encap type not specified");
1154 err
= lwtunnel_build_state(cfg
->fc_encap_type
,
1155 cfg
->fc_encap
, AF_INET
, cfg
,
1160 nh
->nh_lwtstate
= lwtstate_get(lwtstate
);
1162 nh
->nh_oif
= cfg
->fc_oif
;
1163 nh
->nh_gw
= cfg
->fc_gw
;
1164 nh
->nh_flags
= cfg
->fc_flags
;
1165 #ifdef CONFIG_IP_ROUTE_CLASSID
1166 nh
->nh_tclassid
= cfg
->fc_flow
;
1167 if (nh
->nh_tclassid
)
1168 fi
->fib_net
->ipv4
.fib_num_tclassid_users
++;
1170 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1175 if (fib_props
[cfg
->fc_type
].error
) {
1176 if (cfg
->fc_gw
|| cfg
->fc_oif
|| cfg
->fc_mp
) {
1177 NL_SET_ERR_MSG(extack
,
1178 "Gateway, device and multipath can not be specified for this route type");
1183 switch (cfg
->fc_type
) {
1191 NL_SET_ERR_MSG(extack
, "Invalid route type");
1196 if (cfg
->fc_scope
> RT_SCOPE_HOST
) {
1197 NL_SET_ERR_MSG(extack
, "Invalid scope");
1201 if (cfg
->fc_scope
== RT_SCOPE_HOST
) {
1202 struct fib_nh
*nh
= fi
->fib_nh
;
1204 /* Local address is added. */
1206 NL_SET_ERR_MSG(extack
,
1207 "Route with host scope can not have multiple nexthops");
1211 NL_SET_ERR_MSG(extack
,
1212 "Route with host scope can not have a gateway");
1215 nh
->nh_scope
= RT_SCOPE_NOWHERE
;
1216 nh
->nh_dev
= dev_get_by_index(net
, fi
->fib_nh
->nh_oif
);
1223 change_nexthops(fi
) {
1224 err
= fib_check_nh(cfg
, fi
, nexthop_nh
, extack
);
1227 if (nexthop_nh
->nh_flags
& RTNH_F_LINKDOWN
)
1229 } endfor_nexthops(fi
)
1230 if (linkdown
== fi
->fib_nhs
)
1231 fi
->fib_flags
|= RTNH_F_LINKDOWN
;
1234 if (fi
->fib_prefsrc
&& !fib_valid_prefsrc(cfg
, fi
->fib_prefsrc
)) {
1235 NL_SET_ERR_MSG(extack
, "Invalid prefsrc address");
1239 change_nexthops(fi
) {
1240 fib_info_update_nh_saddr(net
, nexthop_nh
);
1241 fib_add_weight(fi
, nexthop_nh
);
1242 } endfor_nexthops(fi
)
1247 ofi
= fib_find_info(fi
);
1256 refcount_set(&fi
->fib_clntref
, 1);
1257 spin_lock_bh(&fib_info_lock
);
1258 hlist_add_head(&fi
->fib_hash
,
1259 &fib_info_hash
[fib_info_hashfn(fi
)]);
1260 if (fi
->fib_prefsrc
) {
1261 struct hlist_head
*head
;
1263 head
= &fib_info_laddrhash
[fib_laddr_hashfn(fi
->fib_prefsrc
)];
1264 hlist_add_head(&fi
->fib_lhash
, head
);
1266 change_nexthops(fi
) {
1267 struct hlist_head
*head
;
1270 if (!nexthop_nh
->nh_dev
)
1272 hash
= fib_devindex_hashfn(nexthop_nh
->nh_dev
->ifindex
);
1273 head
= &fib_info_devhash
[hash
];
1274 hlist_add_head(&nexthop_nh
->nh_hash
, head
);
1275 } endfor_nexthops(fi
)
1276 spin_unlock_bh(&fib_info_lock
);
1288 return ERR_PTR(err
);
1291 int fib_dump_info(struct sk_buff
*skb
, u32 portid
, u32 seq
, int event
,
1292 u32 tb_id
, u8 type
, __be32 dst
, int dst_len
, u8 tos
,
1293 struct fib_info
*fi
, unsigned int flags
)
1295 struct nlmsghdr
*nlh
;
1298 nlh
= nlmsg_put(skb
, portid
, seq
, event
, sizeof(*rtm
), flags
);
1302 rtm
= nlmsg_data(nlh
);
1303 rtm
->rtm_family
= AF_INET
;
1304 rtm
->rtm_dst_len
= dst_len
;
1305 rtm
->rtm_src_len
= 0;
1308 rtm
->rtm_table
= tb_id
;
1310 rtm
->rtm_table
= RT_TABLE_COMPAT
;
1311 if (nla_put_u32(skb
, RTA_TABLE
, tb_id
))
1312 goto nla_put_failure
;
1313 rtm
->rtm_type
= type
;
1314 rtm
->rtm_flags
= fi
->fib_flags
;
1315 rtm
->rtm_scope
= fi
->fib_scope
;
1316 rtm
->rtm_protocol
= fi
->fib_protocol
;
1318 if (rtm
->rtm_dst_len
&&
1319 nla_put_in_addr(skb
, RTA_DST
, dst
))
1320 goto nla_put_failure
;
1321 if (fi
->fib_priority
&&
1322 nla_put_u32(skb
, RTA_PRIORITY
, fi
->fib_priority
))
1323 goto nla_put_failure
;
1324 if (rtnetlink_put_metrics(skb
, fi
->fib_metrics
->metrics
) < 0)
1325 goto nla_put_failure
;
1327 if (fi
->fib_prefsrc
&&
1328 nla_put_in_addr(skb
, RTA_PREFSRC
, fi
->fib_prefsrc
))
1329 goto nla_put_failure
;
1330 if (fi
->fib_nhs
== 1) {
1331 struct in_device
*in_dev
;
1333 if (fi
->fib_nh
->nh_gw
&&
1334 nla_put_in_addr(skb
, RTA_GATEWAY
, fi
->fib_nh
->nh_gw
))
1335 goto nla_put_failure
;
1336 if (fi
->fib_nh
->nh_oif
&&
1337 nla_put_u32(skb
, RTA_OIF
, fi
->fib_nh
->nh_oif
))
1338 goto nla_put_failure
;
1339 if (fi
->fib_nh
->nh_flags
& RTNH_F_LINKDOWN
) {
1340 in_dev
= __in_dev_get_rtnl(fi
->fib_nh
->nh_dev
);
1342 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
))
1343 rtm
->rtm_flags
|= RTNH_F_DEAD
;
1345 #ifdef CONFIG_IP_ROUTE_CLASSID
1346 if (fi
->fib_nh
[0].nh_tclassid
&&
1347 nla_put_u32(skb
, RTA_FLOW
, fi
->fib_nh
[0].nh_tclassid
))
1348 goto nla_put_failure
;
1350 if (fi
->fib_nh
->nh_lwtstate
&&
1351 lwtunnel_fill_encap(skb
, fi
->fib_nh
->nh_lwtstate
) < 0)
1352 goto nla_put_failure
;
1354 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1355 if (fi
->fib_nhs
> 1) {
1356 struct rtnexthop
*rtnh
;
1359 mp
= nla_nest_start(skb
, RTA_MULTIPATH
);
1361 goto nla_put_failure
;
1364 struct in_device
*in_dev
;
1366 rtnh
= nla_reserve_nohdr(skb
, sizeof(*rtnh
));
1368 goto nla_put_failure
;
1370 rtnh
->rtnh_flags
= nh
->nh_flags
& 0xFF;
1371 if (nh
->nh_flags
& RTNH_F_LINKDOWN
) {
1372 in_dev
= __in_dev_get_rtnl(nh
->nh_dev
);
1374 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
))
1375 rtnh
->rtnh_flags
|= RTNH_F_DEAD
;
1377 rtnh
->rtnh_hops
= nh
->nh_weight
- 1;
1378 rtnh
->rtnh_ifindex
= nh
->nh_oif
;
1381 nla_put_in_addr(skb
, RTA_GATEWAY
, nh
->nh_gw
))
1382 goto nla_put_failure
;
1383 #ifdef CONFIG_IP_ROUTE_CLASSID
1384 if (nh
->nh_tclassid
&&
1385 nla_put_u32(skb
, RTA_FLOW
, nh
->nh_tclassid
))
1386 goto nla_put_failure
;
1388 if (nh
->nh_lwtstate
&&
1389 lwtunnel_fill_encap(skb
, nh
->nh_lwtstate
) < 0)
1390 goto nla_put_failure
;
1392 /* length of rtnetlink header + attributes */
1393 rtnh
->rtnh_len
= nlmsg_get_pos(skb
) - (void *) rtnh
;
1394 } endfor_nexthops(fi
);
1396 nla_nest_end(skb
, mp
);
1399 nlmsg_end(skb
, nlh
);
1403 nlmsg_cancel(skb
, nlh
);
1409 * - local address disappeared -> we must delete all the entries
1411 * - device went down -> we must shutdown all nexthops going via it.
1413 int fib_sync_down_addr(struct net_device
*dev
, __be32 local
)
1416 unsigned int hash
= fib_laddr_hashfn(local
);
1417 struct hlist_head
*head
= &fib_info_laddrhash
[hash
];
1418 struct net
*net
= dev_net(dev
);
1419 int tb_id
= l3mdev_fib_table(dev
);
1420 struct fib_info
*fi
;
1422 if (!fib_info_laddrhash
|| local
== 0)
1425 hlist_for_each_entry(fi
, head
, fib_lhash
) {
1426 if (!net_eq(fi
->fib_net
, net
) ||
1427 fi
->fib_tb_id
!= tb_id
)
1429 if (fi
->fib_prefsrc
== local
) {
1430 fi
->fib_flags
|= RTNH_F_DEAD
;
1437 static int call_fib_nh_notifiers(struct fib_nh
*fib_nh
,
1438 enum fib_event_type event_type
)
1440 struct in_device
*in_dev
= __in_dev_get_rtnl(fib_nh
->nh_dev
);
1441 struct fib_nh_notifier_info info
= {
1445 switch (event_type
) {
1446 case FIB_EVENT_NH_ADD
:
1447 if (fib_nh
->nh_flags
& RTNH_F_DEAD
)
1449 if (IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
) &&
1450 fib_nh
->nh_flags
& RTNH_F_LINKDOWN
)
1452 return call_fib_notifiers(dev_net(fib_nh
->nh_dev
), event_type
,
1454 case FIB_EVENT_NH_DEL
:
1455 if ((in_dev
&& IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
) &&
1456 fib_nh
->nh_flags
& RTNH_F_LINKDOWN
) ||
1457 (fib_nh
->nh_flags
& RTNH_F_DEAD
))
1458 return call_fib_notifiers(dev_net(fib_nh
->nh_dev
),
1459 event_type
, &info
.info
);
1467 /* Event force Flags Description
1468 * NETDEV_CHANGE 0 LINKDOWN Carrier OFF, not for scope host
1469 * NETDEV_DOWN 0 LINKDOWN|DEAD Link down, not for scope host
1470 * NETDEV_DOWN 1 LINKDOWN|DEAD Last address removed
1471 * NETDEV_UNREGISTER 1 LINKDOWN|DEAD Device removed
1473 int fib_sync_down_dev(struct net_device
*dev
, unsigned long event
, bool force
)
1476 int scope
= RT_SCOPE_NOWHERE
;
1477 struct fib_info
*prev_fi
= NULL
;
1478 unsigned int hash
= fib_devindex_hashfn(dev
->ifindex
);
1479 struct hlist_head
*head
= &fib_info_devhash
[hash
];
1485 hlist_for_each_entry(nh
, head
, nh_hash
) {
1486 struct fib_info
*fi
= nh
->nh_parent
;
1489 BUG_ON(!fi
->fib_nhs
);
1490 if (nh
->nh_dev
!= dev
|| fi
== prev_fi
)
1494 change_nexthops(fi
) {
1495 if (nexthop_nh
->nh_flags
& RTNH_F_DEAD
)
1497 else if (nexthop_nh
->nh_dev
== dev
&&
1498 nexthop_nh
->nh_scope
!= scope
) {
1501 case NETDEV_UNREGISTER
:
1502 nexthop_nh
->nh_flags
|= RTNH_F_DEAD
;
1505 nexthop_nh
->nh_flags
|= RTNH_F_LINKDOWN
;
1508 call_fib_nh_notifiers(nexthop_nh
,
1512 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1513 if (event
== NETDEV_UNREGISTER
&&
1514 nexthop_nh
->nh_dev
== dev
) {
1519 } endfor_nexthops(fi
)
1520 if (dead
== fi
->fib_nhs
) {
1523 case NETDEV_UNREGISTER
:
1524 fi
->fib_flags
|= RTNH_F_DEAD
;
1527 fi
->fib_flags
|= RTNH_F_LINKDOWN
;
1539 /* Must be invoked inside of an RCU protected region. */
1540 static void fib_select_default(const struct flowi4
*flp
, struct fib_result
*res
)
1542 struct fib_info
*fi
= NULL
, *last_resort
= NULL
;
1543 struct hlist_head
*fa_head
= res
->fa_head
;
1544 struct fib_table
*tb
= res
->table
;
1545 u8 slen
= 32 - res
->prefixlen
;
1546 int order
= -1, last_idx
= -1;
1547 struct fib_alias
*fa
, *fa1
= NULL
;
1548 u32 last_prio
= res
->fi
->fib_priority
;
1551 hlist_for_each_entry_rcu(fa
, fa_head
, fa_list
) {
1552 struct fib_info
*next_fi
= fa
->fa_info
;
1554 if (fa
->fa_slen
!= slen
)
1556 if (fa
->fa_tos
&& fa
->fa_tos
!= flp
->flowi4_tos
)
1558 if (fa
->tb_id
!= tb
->tb_id
)
1560 if (next_fi
->fib_priority
> last_prio
&&
1561 fa
->fa_tos
== last_tos
) {
1566 if (next_fi
->fib_flags
& RTNH_F_DEAD
)
1568 last_tos
= fa
->fa_tos
;
1569 last_prio
= next_fi
->fib_priority
;
1571 if (next_fi
->fib_scope
!= res
->scope
||
1572 fa
->fa_type
!= RTN_UNICAST
)
1574 if (!next_fi
->fib_nh
[0].nh_gw
||
1575 next_fi
->fib_nh
[0].nh_scope
!= RT_SCOPE_LINK
)
1578 fib_alias_accessed(fa
);
1581 if (next_fi
!= res
->fi
)
1584 } else if (!fib_detect_death(fi
, order
, &last_resort
,
1585 &last_idx
, fa1
->fa_default
)) {
1586 fib_result_assign(res
, fi
);
1587 fa1
->fa_default
= order
;
1594 if (order
<= 0 || !fi
) {
1596 fa1
->fa_default
= -1;
1600 if (!fib_detect_death(fi
, order
, &last_resort
, &last_idx
,
1602 fib_result_assign(res
, fi
);
1603 fa1
->fa_default
= order
;
1608 fib_result_assign(res
, last_resort
);
1609 fa1
->fa_default
= last_idx
;
1615 * Dead device goes up. We wake up dead nexthops.
1616 * It takes sense only on multipath routes.
1618 int fib_sync_up(struct net_device
*dev
, unsigned int nh_flags
)
1620 struct fib_info
*prev_fi
;
1622 struct hlist_head
*head
;
1626 if (!(dev
->flags
& IFF_UP
))
1629 if (nh_flags
& RTNH_F_DEAD
) {
1630 unsigned int flags
= dev_get_flags(dev
);
1632 if (flags
& (IFF_RUNNING
| IFF_LOWER_UP
))
1633 nh_flags
|= RTNH_F_LINKDOWN
;
1637 hash
= fib_devindex_hashfn(dev
->ifindex
);
1638 head
= &fib_info_devhash
[hash
];
1641 hlist_for_each_entry(nh
, head
, nh_hash
) {
1642 struct fib_info
*fi
= nh
->nh_parent
;
1645 BUG_ON(!fi
->fib_nhs
);
1646 if (nh
->nh_dev
!= dev
|| fi
== prev_fi
)
1651 change_nexthops(fi
) {
1652 if (!(nexthop_nh
->nh_flags
& nh_flags
)) {
1656 if (!nexthop_nh
->nh_dev
||
1657 !(nexthop_nh
->nh_dev
->flags
& IFF_UP
))
1659 if (nexthop_nh
->nh_dev
!= dev
||
1660 !__in_dev_get_rtnl(dev
))
1663 nexthop_nh
->nh_flags
&= ~nh_flags
;
1664 call_fib_nh_notifiers(nexthop_nh
, FIB_EVENT_NH_ADD
);
1665 } endfor_nexthops(fi
)
1668 fi
->fib_flags
&= ~nh_flags
;
1678 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1679 static bool fib_good_nh(const struct fib_nh
*nh
)
1681 int state
= NUD_REACHABLE
;
1683 if (nh
->nh_scope
== RT_SCOPE_LINK
) {
1684 struct neighbour
*n
;
1688 n
= __ipv4_neigh_lookup_noref(nh
->nh_dev
,
1689 (__force u32
)nh
->nh_gw
);
1691 state
= n
->nud_state
;
1693 rcu_read_unlock_bh();
1696 return !!(state
& NUD_VALID
);
1699 void fib_select_multipath(struct fib_result
*res
, int hash
)
1701 struct fib_info
*fi
= res
->fi
;
1702 struct net
*net
= fi
->fib_net
;
1706 if (hash
> atomic_read(&nh
->nh_upper_bound
))
1709 if (!net
->ipv4
.sysctl_fib_multipath_use_neigh
||
1711 res
->nh_sel
= nhsel
;
1715 res
->nh_sel
= nhsel
;
1718 } endfor_nexthops(fi
);
1722 void fib_select_path(struct net
*net
, struct fib_result
*res
,
1723 struct flowi4
*fl4
, const struct sk_buff
*skb
)
1727 oif_check
= (fl4
->flowi4_oif
== 0 ||
1728 fl4
->flowi4_flags
& FLOWI_FLAG_SKIP_NH_OIF
);
1730 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1731 if (res
->fi
->fib_nhs
> 1 && oif_check
) {
1732 int h
= fib_multipath_hash(res
->fi
, fl4
, skb
);
1734 fib_select_multipath(res
, h
);
1738 if (!res
->prefixlen
&&
1739 res
->table
->tb_num_default
> 1 &&
1740 res
->type
== RTN_UNICAST
&& oif_check
)
1741 fib_select_default(fl4
, res
);
1744 fl4
->saddr
= FIB_RES_PREFSRC(net
, *res
);
1746 EXPORT_SYMBOL_GPL(fib_select_path
);