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>
38 #include <net/protocol.h>
39 #include <net/route.h>
42 #include <net/ip_fib.h>
43 #include <net/netlink.h>
44 #include <net/nexthop.h>
45 #include <net/lwtunnel.h>
47 #include "fib_lookup.h"
49 static DEFINE_SPINLOCK(fib_info_lock
);
50 static struct hlist_head
*fib_info_hash
;
51 static struct hlist_head
*fib_info_laddrhash
;
52 static unsigned int fib_info_hash_size
;
53 static unsigned int fib_info_cnt
;
55 #define DEVINDEX_HASHBITS 8
56 #define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS)
57 static struct hlist_head fib_info_devhash
[DEVINDEX_HASHSIZE
];
59 #ifdef CONFIG_IP_ROUTE_MULTIPATH
61 #define for_nexthops(fi) { \
62 int nhsel; const struct fib_nh *nh; \
63 for (nhsel = 0, nh = (fi)->fib_nh; \
64 nhsel < (fi)->fib_nhs; \
67 #define change_nexthops(fi) { \
68 int nhsel; struct fib_nh *nexthop_nh; \
69 for (nhsel = 0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
70 nhsel < (fi)->fib_nhs; \
71 nexthop_nh++, nhsel++)
73 #else /* CONFIG_IP_ROUTE_MULTIPATH */
75 /* Hope, that gcc will optimize it to get rid of dummy loop */
77 #define for_nexthops(fi) { \
78 int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \
79 for (nhsel = 0; nhsel < 1; nhsel++)
81 #define change_nexthops(fi) { \
83 struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
84 for (nhsel = 0; nhsel < 1; nhsel++)
86 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
88 #define endfor_nexthops(fi) }
91 const struct fib_prop fib_props
[RTN_MAX
+ 1] = {
94 .scope
= RT_SCOPE_NOWHERE
,
98 .scope
= RT_SCOPE_UNIVERSE
,
102 .scope
= RT_SCOPE_HOST
,
106 .scope
= RT_SCOPE_LINK
,
110 .scope
= RT_SCOPE_LINK
,
114 .scope
= RT_SCOPE_UNIVERSE
,
118 .scope
= RT_SCOPE_UNIVERSE
,
120 [RTN_UNREACHABLE
] = {
121 .error
= -EHOSTUNREACH
,
122 .scope
= RT_SCOPE_UNIVERSE
,
126 .scope
= RT_SCOPE_UNIVERSE
,
130 .scope
= RT_SCOPE_UNIVERSE
,
134 .scope
= RT_SCOPE_NOWHERE
,
138 .scope
= RT_SCOPE_NOWHERE
,
142 static void rt_fibinfo_free(struct rtable __rcu
**rtp
)
144 struct rtable
*rt
= rcu_dereference_protected(*rtp
, 1);
149 /* Not even needed : RCU_INIT_POINTER(*rtp, NULL);
150 * because we waited an RCU grace period before calling
151 * free_fib_info_rcu()
157 static void free_nh_exceptions(struct fib_nh
*nh
)
159 struct fnhe_hash_bucket
*hash
;
162 hash
= rcu_dereference_protected(nh
->nh_exceptions
, 1);
165 for (i
= 0; i
< FNHE_HASH_SIZE
; i
++) {
166 struct fib_nh_exception
*fnhe
;
168 fnhe
= rcu_dereference_protected(hash
[i
].chain
, 1);
170 struct fib_nh_exception
*next
;
172 next
= rcu_dereference_protected(fnhe
->fnhe_next
, 1);
174 rt_fibinfo_free(&fnhe
->fnhe_rth_input
);
175 rt_fibinfo_free(&fnhe
->fnhe_rth_output
);
185 static void rt_fibinfo_free_cpus(struct rtable __rcu
* __percpu
*rtp
)
192 for_each_possible_cpu(cpu
) {
195 rt
= rcu_dereference_protected(*per_cpu_ptr(rtp
, cpu
), 1);
202 /* Release a nexthop info record */
203 static void free_fib_info_rcu(struct rcu_head
*head
)
205 struct fib_info
*fi
= container_of(head
, struct fib_info
, rcu
);
206 struct dst_metrics
*m
;
208 change_nexthops(fi
) {
209 if (nexthop_nh
->nh_dev
)
210 dev_put(nexthop_nh
->nh_dev
);
211 lwtstate_put(nexthop_nh
->nh_lwtstate
);
212 free_nh_exceptions(nexthop_nh
);
213 rt_fibinfo_free_cpus(nexthop_nh
->nh_pcpu_rth_output
);
214 rt_fibinfo_free(&nexthop_nh
->nh_rth_input
);
215 } endfor_nexthops(fi
);
218 if (m
!= &dst_default_metrics
&& atomic_dec_and_test(&m
->refcnt
))
223 void free_fib_info(struct fib_info
*fi
)
225 if (fi
->fib_dead
== 0) {
226 pr_warn("Freeing alive fib_info %p\n", fi
);
230 #ifdef CONFIG_IP_ROUTE_CLASSID
231 change_nexthops(fi
) {
232 if (nexthop_nh
->nh_tclassid
)
233 fi
->fib_net
->ipv4
.fib_num_tclassid_users
--;
234 } endfor_nexthops(fi
);
236 call_rcu(&fi
->rcu
, free_fib_info_rcu
);
238 EXPORT_SYMBOL_GPL(free_fib_info
);
240 void fib_release_info(struct fib_info
*fi
)
242 spin_lock_bh(&fib_info_lock
);
243 if (fi
&& --fi
->fib_treeref
== 0) {
244 hlist_del(&fi
->fib_hash
);
246 hlist_del(&fi
->fib_lhash
);
247 change_nexthops(fi
) {
248 if (!nexthop_nh
->nh_dev
)
250 hlist_del(&nexthop_nh
->nh_hash
);
251 } endfor_nexthops(fi
)
255 spin_unlock_bh(&fib_info_lock
);
258 static inline int nh_comp(const struct fib_info
*fi
, const struct fib_info
*ofi
)
260 const struct fib_nh
*onh
= ofi
->fib_nh
;
263 if (nh
->nh_oif
!= onh
->nh_oif
||
264 nh
->nh_gw
!= onh
->nh_gw
||
265 nh
->nh_scope
!= onh
->nh_scope
||
266 #ifdef CONFIG_IP_ROUTE_MULTIPATH
267 nh
->nh_weight
!= onh
->nh_weight
||
269 #ifdef CONFIG_IP_ROUTE_CLASSID
270 nh
->nh_tclassid
!= onh
->nh_tclassid
||
272 lwtunnel_cmp_encap(nh
->nh_lwtstate
, onh
->nh_lwtstate
) ||
273 ((nh
->nh_flags
^ onh
->nh_flags
) & ~RTNH_COMPARE_MASK
))
276 } endfor_nexthops(fi
);
280 static inline unsigned int fib_devindex_hashfn(unsigned int val
)
282 unsigned int mask
= DEVINDEX_HASHSIZE
- 1;
285 (val
>> DEVINDEX_HASHBITS
) ^
286 (val
>> (DEVINDEX_HASHBITS
* 2))) & mask
;
289 static inline unsigned int fib_info_hashfn(const struct fib_info
*fi
)
291 unsigned int mask
= (fib_info_hash_size
- 1);
292 unsigned int val
= fi
->fib_nhs
;
294 val
^= (fi
->fib_protocol
<< 8) | fi
->fib_scope
;
295 val
^= (__force u32
)fi
->fib_prefsrc
;
296 val
^= fi
->fib_priority
;
298 val
^= fib_devindex_hashfn(nh
->nh_oif
);
299 } endfor_nexthops(fi
)
301 return (val
^ (val
>> 7) ^ (val
>> 12)) & mask
;
304 static struct fib_info
*fib_find_info(const struct fib_info
*nfi
)
306 struct hlist_head
*head
;
310 hash
= fib_info_hashfn(nfi
);
311 head
= &fib_info_hash
[hash
];
313 hlist_for_each_entry(fi
, head
, fib_hash
) {
314 if (!net_eq(fi
->fib_net
, nfi
->fib_net
))
316 if (fi
->fib_nhs
!= nfi
->fib_nhs
)
318 if (nfi
->fib_protocol
== fi
->fib_protocol
&&
319 nfi
->fib_scope
== fi
->fib_scope
&&
320 nfi
->fib_prefsrc
== fi
->fib_prefsrc
&&
321 nfi
->fib_priority
== fi
->fib_priority
&&
322 nfi
->fib_type
== fi
->fib_type
&&
323 memcmp(nfi
->fib_metrics
, fi
->fib_metrics
,
324 sizeof(u32
) * RTAX_MAX
) == 0 &&
325 !((nfi
->fib_flags
^ fi
->fib_flags
) & ~RTNH_COMPARE_MASK
) &&
326 (nfi
->fib_nhs
== 0 || nh_comp(fi
, nfi
) == 0))
333 /* Check, that the gateway is already configured.
334 * Used only by redirect accept routine.
336 int ip_fib_check_default(__be32 gw
, struct net_device
*dev
)
338 struct hlist_head
*head
;
342 spin_lock(&fib_info_lock
);
344 hash
= fib_devindex_hashfn(dev
->ifindex
);
345 head
= &fib_info_devhash
[hash
];
346 hlist_for_each_entry(nh
, head
, nh_hash
) {
347 if (nh
->nh_dev
== dev
&&
349 !(nh
->nh_flags
& RTNH_F_DEAD
)) {
350 spin_unlock(&fib_info_lock
);
355 spin_unlock(&fib_info_lock
);
360 static inline size_t fib_nlmsg_size(struct fib_info
*fi
)
362 size_t payload
= NLMSG_ALIGN(sizeof(struct rtmsg
))
363 + nla_total_size(4) /* RTA_TABLE */
364 + nla_total_size(4) /* RTA_DST */
365 + nla_total_size(4) /* RTA_PRIORITY */
366 + nla_total_size(4) /* RTA_PREFSRC */
367 + nla_total_size(TCP_CA_NAME_MAX
); /* RTAX_CC_ALGO */
369 /* space for nested metrics */
370 payload
+= nla_total_size((RTAX_MAX
* nla_total_size(4)));
373 size_t nh_encapsize
= 0;
374 /* Also handles the special case fib_nhs == 1 */
376 /* each nexthop is packed in an attribute */
377 size_t nhsize
= nla_total_size(sizeof(struct rtnexthop
));
379 /* may contain flow and gateway attribute */
380 nhsize
+= 2 * nla_total_size(4);
382 /* grab encap info */
384 if (nh
->nh_lwtstate
) {
386 nh_encapsize
+= lwtunnel_get_encap_size(
389 nh_encapsize
+= nla_total_size(2);
391 } endfor_nexthops(fi
);
393 /* all nexthops are packed in a nested attribute */
394 payload
+= nla_total_size((fi
->fib_nhs
* nhsize
) +
402 void rtmsg_fib(int event
, __be32 key
, struct fib_alias
*fa
,
403 int dst_len
, u32 tb_id
, const struct nl_info
*info
,
404 unsigned int nlm_flags
)
407 u32 seq
= info
->nlh
? info
->nlh
->nlmsg_seq
: 0;
410 skb
= nlmsg_new(fib_nlmsg_size(fa
->fa_info
), GFP_KERNEL
);
414 err
= fib_dump_info(skb
, info
->portid
, seq
, event
, tb_id
,
415 fa
->fa_type
, key
, dst_len
,
416 fa
->fa_tos
, fa
->fa_info
, nlm_flags
);
418 /* -EMSGSIZE implies BUG in fib_nlmsg_size() */
419 WARN_ON(err
== -EMSGSIZE
);
423 rtnl_notify(skb
, info
->nl_net
, info
->portid
, RTNLGRP_IPV4_ROUTE
,
424 info
->nlh
, GFP_KERNEL
);
428 rtnl_set_sk_err(info
->nl_net
, RTNLGRP_IPV4_ROUTE
, err
);
431 static int fib_detect_death(struct fib_info
*fi
, int order
,
432 struct fib_info
**last_resort
, int *last_idx
,
436 int state
= NUD_NONE
;
438 n
= neigh_lookup(&arp_tbl
, &fi
->fib_nh
[0].nh_gw
, fi
->fib_dev
);
440 state
= n
->nud_state
;
445 if (state
== NUD_REACHABLE
)
447 if ((state
& NUD_VALID
) && order
!= dflt
)
449 if ((state
& NUD_VALID
) ||
450 (*last_idx
< 0 && order
> dflt
&& state
!= NUD_INCOMPLETE
)) {
457 #ifdef CONFIG_IP_ROUTE_MULTIPATH
459 static int fib_count_nexthops(struct rtnexthop
*rtnh
, int remaining
)
463 while (rtnh_ok(rtnh
, remaining
)) {
465 rtnh
= rtnh_next(rtnh
, &remaining
);
468 /* leftover implies invalid nexthop configuration, discard it */
469 return remaining
> 0 ? 0 : nhs
;
472 static int fib_get_nhs(struct fib_info
*fi
, struct rtnexthop
*rtnh
,
473 int remaining
, struct fib_config
*cfg
)
477 change_nexthops(fi
) {
480 if (!rtnh_ok(rtnh
, remaining
))
483 if (rtnh
->rtnh_flags
& (RTNH_F_DEAD
| RTNH_F_LINKDOWN
))
486 nexthop_nh
->nh_flags
=
487 (cfg
->fc_flags
& ~0xFF) | rtnh
->rtnh_flags
;
488 nexthop_nh
->nh_oif
= rtnh
->rtnh_ifindex
;
489 nexthop_nh
->nh_weight
= rtnh
->rtnh_hops
+ 1;
491 attrlen
= rtnh_attrlen(rtnh
);
493 struct nlattr
*nla
, *attrs
= rtnh_attrs(rtnh
);
495 nla
= nla_find(attrs
, attrlen
, RTA_GATEWAY
);
496 nexthop_nh
->nh_gw
= nla
? nla_get_in_addr(nla
) : 0;
497 #ifdef CONFIG_IP_ROUTE_CLASSID
498 nla
= nla_find(attrs
, attrlen
, RTA_FLOW
);
499 nexthop_nh
->nh_tclassid
= nla
? nla_get_u32(nla
) : 0;
500 if (nexthop_nh
->nh_tclassid
)
501 fi
->fib_net
->ipv4
.fib_num_tclassid_users
++;
503 nla
= nla_find(attrs
, attrlen
, RTA_ENCAP
);
505 struct lwtunnel_state
*lwtstate
;
506 struct nlattr
*nla_entype
;
508 nla_entype
= nla_find(attrs
, attrlen
,
513 ret
= lwtunnel_build_state(nla_get_u16(
519 nexthop_nh
->nh_lwtstate
=
520 lwtstate_get(lwtstate
);
524 rtnh
= rtnh_next(rtnh
, &remaining
);
525 } endfor_nexthops(fi
);
536 static void fib_rebalance(struct fib_info
*fi
)
540 struct in_device
*in_dev
;
547 if (nh
->nh_flags
& RTNH_F_DEAD
)
550 in_dev
= __in_dev_get_rtnl(nh
->nh_dev
);
553 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
) &&
554 nh
->nh_flags
& RTNH_F_LINKDOWN
)
557 total
+= nh
->nh_weight
;
558 } endfor_nexthops(fi
);
561 change_nexthops(fi
) {
564 in_dev
= __in_dev_get_rtnl(nexthop_nh
->nh_dev
);
566 if (nexthop_nh
->nh_flags
& RTNH_F_DEAD
) {
569 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
) &&
570 nexthop_nh
->nh_flags
& RTNH_F_LINKDOWN
) {
573 w
+= nexthop_nh
->nh_weight
;
574 upper_bound
= DIV_ROUND_CLOSEST_ULL((u64
)w
<< 31,
578 atomic_set(&nexthop_nh
->nh_upper_bound
, upper_bound
);
579 } endfor_nexthops(fi
);
582 static inline void fib_add_weight(struct fib_info
*fi
,
583 const struct fib_nh
*nh
)
585 fi
->fib_weight
+= nh
->nh_weight
;
588 #else /* CONFIG_IP_ROUTE_MULTIPATH */
590 #define fib_rebalance(fi) do { } while (0)
591 #define fib_add_weight(fi, nh) do { } while (0)
593 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
595 static int fib_encap_match(u16 encap_type
,
596 struct nlattr
*encap
,
597 const struct fib_nh
*nh
,
598 const struct fib_config
*cfg
)
600 struct lwtunnel_state
*lwtstate
;
603 if (encap_type
== LWTUNNEL_ENCAP_NONE
)
606 ret
= lwtunnel_build_state(encap_type
, encap
,
607 AF_INET
, cfg
, &lwtstate
);
609 result
= lwtunnel_cmp_encap(lwtstate
, nh
->nh_lwtstate
);
610 lwtstate_free(lwtstate
);
616 int fib_nh_match(struct fib_config
*cfg
, struct fib_info
*fi
)
618 #ifdef CONFIG_IP_ROUTE_MULTIPATH
619 struct rtnexthop
*rtnh
;
623 if (cfg
->fc_priority
&& cfg
->fc_priority
!= fi
->fib_priority
)
626 if (cfg
->fc_oif
|| cfg
->fc_gw
) {
628 if (fib_encap_match(cfg
->fc_encap_type
,
629 cfg
->fc_encap
, fi
->fib_nh
, cfg
))
632 if ((!cfg
->fc_oif
|| cfg
->fc_oif
== fi
->fib_nh
->nh_oif
) &&
633 (!cfg
->fc_gw
|| cfg
->fc_gw
== fi
->fib_nh
->nh_gw
))
638 #ifdef CONFIG_IP_ROUTE_MULTIPATH
643 remaining
= cfg
->fc_mp_len
;
648 if (!rtnh_ok(rtnh
, remaining
))
651 if (rtnh
->rtnh_ifindex
&& rtnh
->rtnh_ifindex
!= nh
->nh_oif
)
654 attrlen
= rtnh_attrlen(rtnh
);
656 struct nlattr
*nla
, *attrs
= rtnh_attrs(rtnh
);
658 nla
= nla_find(attrs
, attrlen
, RTA_GATEWAY
);
659 if (nla
&& nla_get_in_addr(nla
) != nh
->nh_gw
)
661 #ifdef CONFIG_IP_ROUTE_CLASSID
662 nla
= nla_find(attrs
, attrlen
, RTA_FLOW
);
663 if (nla
&& nla_get_u32(nla
) != nh
->nh_tclassid
)
668 rtnh
= rtnh_next(rtnh
, &remaining
);
669 } endfor_nexthops(fi
);
679 * Semantics of nexthop is very messy by historical reasons.
680 * We have to take into account, that:
681 * a) gateway can be actually local interface address,
682 * so that gatewayed route is direct.
683 * b) gateway must be on-link address, possibly
684 * described not by an ifaddr, but also by a direct route.
685 * c) If both gateway and interface are specified, they should not
687 * d) If we use tunnel routes, gateway could be not on-link.
689 * Attempt to reconcile all of these (alas, self-contradictory) conditions
690 * results in pretty ugly and hairy code with obscure logic.
692 * I chose to generalized it instead, so that the size
693 * of code does not increase practically, but it becomes
695 * Every prefix is assigned a "scope" value: "host" is local address,
696 * "link" is direct route,
697 * [ ... "site" ... "interior" ... ]
698 * and "universe" is true gateway route with global meaning.
700 * Every prefix refers to a set of "nexthop"s (gw, oif),
701 * where gw must have narrower scope. This recursion stops
702 * when gw has LOCAL scope or if "nexthop" is declared ONLINK,
703 * which means that gw is forced to be on link.
705 * Code is still hairy, but now it is apparently logically
706 * consistent and very flexible. F.e. as by-product it allows
707 * to co-exists in peace independent exterior and interior
710 * Normally it looks as following.
712 * {universe prefix} -> (gw, oif) [scope link]
714 * |-> {link prefix} -> (gw, oif) [scope local]
716 * |-> {local prefix} (terminal node)
718 static int fib_check_nh(struct fib_config
*cfg
, struct fib_info
*fi
,
723 struct net_device
*dev
;
725 net
= cfg
->fc_nlinfo
.nl_net
;
727 struct fib_result res
;
729 if (nh
->nh_flags
& RTNH_F_ONLINK
) {
730 unsigned int addr_type
;
732 if (cfg
->fc_scope
>= RT_SCOPE_LINK
)
734 dev
= __dev_get_by_index(net
, nh
->nh_oif
);
737 if (!(dev
->flags
& IFF_UP
))
739 addr_type
= inet_addr_type_dev_table(net
, dev
, nh
->nh_gw
);
740 if (addr_type
!= RTN_UNICAST
)
742 if (!netif_carrier_ok(dev
))
743 nh
->nh_flags
|= RTNH_F_LINKDOWN
;
746 nh
->nh_scope
= RT_SCOPE_LINK
;
751 struct fib_table
*tbl
= NULL
;
752 struct flowi4 fl4
= {
754 .flowi4_scope
= cfg
->fc_scope
+ 1,
755 .flowi4_oif
= nh
->nh_oif
,
756 .flowi4_iif
= LOOPBACK_IFINDEX
,
759 /* It is not necessary, but requires a bit of thinking */
760 if (fl4
.flowi4_scope
< RT_SCOPE_LINK
)
761 fl4
.flowi4_scope
= RT_SCOPE_LINK
;
764 tbl
= fib_get_table(net
, cfg
->fc_table
);
767 err
= fib_table_lookup(tbl
, &fl4
, &res
,
768 FIB_LOOKUP_IGNORE_LINKSTATE
|
771 /* on error or if no table given do full lookup. This
772 * is needed for example when nexthops are in the local
773 * table rather than the given table
776 err
= fib_lookup(net
, &fl4
, &res
,
777 FIB_LOOKUP_IGNORE_LINKSTATE
);
786 if (res
.type
!= RTN_UNICAST
&& res
.type
!= RTN_LOCAL
)
788 nh
->nh_scope
= res
.scope
;
789 nh
->nh_oif
= FIB_RES_OIF(res
);
790 nh
->nh_dev
= dev
= FIB_RES_DEV(res
);
794 if (!netif_carrier_ok(dev
))
795 nh
->nh_flags
|= RTNH_F_LINKDOWN
;
796 err
= (dev
->flags
& IFF_UP
) ? 0 : -ENETDOWN
;
798 struct in_device
*in_dev
;
800 if (nh
->nh_flags
& (RTNH_F_PERVASIVE
| RTNH_F_ONLINK
))
805 in_dev
= inetdev_by_index(net
, nh
->nh_oif
);
809 if (!(in_dev
->dev
->flags
& IFF_UP
))
811 nh
->nh_dev
= in_dev
->dev
;
812 dev_hold(nh
->nh_dev
);
813 nh
->nh_scope
= RT_SCOPE_HOST
;
814 if (!netif_carrier_ok(nh
->nh_dev
))
815 nh
->nh_flags
|= RTNH_F_LINKDOWN
;
823 static inline unsigned int fib_laddr_hashfn(__be32 val
)
825 unsigned int mask
= (fib_info_hash_size
- 1);
827 return ((__force u32
)val
^
828 ((__force u32
)val
>> 7) ^
829 ((__force u32
)val
>> 14)) & mask
;
832 static struct hlist_head
*fib_info_hash_alloc(int bytes
)
834 if (bytes
<= PAGE_SIZE
)
835 return kzalloc(bytes
, GFP_KERNEL
);
837 return (struct hlist_head
*)
838 __get_free_pages(GFP_KERNEL
| __GFP_ZERO
,
842 static void fib_info_hash_free(struct hlist_head
*hash
, int bytes
)
847 if (bytes
<= PAGE_SIZE
)
850 free_pages((unsigned long) hash
, get_order(bytes
));
853 static void fib_info_hash_move(struct hlist_head
*new_info_hash
,
854 struct hlist_head
*new_laddrhash
,
855 unsigned int new_size
)
857 struct hlist_head
*old_info_hash
, *old_laddrhash
;
858 unsigned int old_size
= fib_info_hash_size
;
859 unsigned int i
, bytes
;
861 spin_lock_bh(&fib_info_lock
);
862 old_info_hash
= fib_info_hash
;
863 old_laddrhash
= fib_info_laddrhash
;
864 fib_info_hash_size
= new_size
;
866 for (i
= 0; i
< old_size
; i
++) {
867 struct hlist_head
*head
= &fib_info_hash
[i
];
868 struct hlist_node
*n
;
871 hlist_for_each_entry_safe(fi
, n
, head
, fib_hash
) {
872 struct hlist_head
*dest
;
873 unsigned int new_hash
;
875 new_hash
= fib_info_hashfn(fi
);
876 dest
= &new_info_hash
[new_hash
];
877 hlist_add_head(&fi
->fib_hash
, dest
);
880 fib_info_hash
= new_info_hash
;
882 for (i
= 0; i
< old_size
; i
++) {
883 struct hlist_head
*lhead
= &fib_info_laddrhash
[i
];
884 struct hlist_node
*n
;
887 hlist_for_each_entry_safe(fi
, n
, lhead
, fib_lhash
) {
888 struct hlist_head
*ldest
;
889 unsigned int new_hash
;
891 new_hash
= fib_laddr_hashfn(fi
->fib_prefsrc
);
892 ldest
= &new_laddrhash
[new_hash
];
893 hlist_add_head(&fi
->fib_lhash
, ldest
);
896 fib_info_laddrhash
= new_laddrhash
;
898 spin_unlock_bh(&fib_info_lock
);
900 bytes
= old_size
* sizeof(struct hlist_head
*);
901 fib_info_hash_free(old_info_hash
, bytes
);
902 fib_info_hash_free(old_laddrhash
, bytes
);
905 __be32
fib_info_update_nh_saddr(struct net
*net
, struct fib_nh
*nh
)
907 nh
->nh_saddr
= inet_select_addr(nh
->nh_dev
,
909 nh
->nh_parent
->fib_scope
);
910 nh
->nh_saddr_genid
= atomic_read(&net
->ipv4
.dev_addr_genid
);
915 static bool fib_valid_prefsrc(struct fib_config
*cfg
, __be32 fib_prefsrc
)
917 if (cfg
->fc_type
!= RTN_LOCAL
|| !cfg
->fc_dst
||
918 fib_prefsrc
!= cfg
->fc_dst
) {
919 u32 tb_id
= cfg
->fc_table
;
922 if (tb_id
== RT_TABLE_MAIN
)
923 tb_id
= RT_TABLE_LOCAL
;
925 rc
= inet_addr_type_table(cfg
->fc_nlinfo
.nl_net
,
928 if (rc
!= RTN_LOCAL
&& tb_id
!= RT_TABLE_LOCAL
) {
929 rc
= inet_addr_type_table(cfg
->fc_nlinfo
.nl_net
,
930 fib_prefsrc
, RT_TABLE_LOCAL
);
940 fib_convert_metrics(struct fib_info
*fi
, const struct fib_config
*cfg
)
949 nla_for_each_attr(nla
, cfg
->fc_mx
, cfg
->fc_mx_len
, remaining
) {
950 int type
= nla_type(nla
);
958 if (type
== RTAX_CC_ALGO
) {
959 char tmp
[TCP_CA_NAME_MAX
];
961 nla_strlcpy(tmp
, nla
, sizeof(tmp
));
962 val
= tcp_ca_get_key_by_name(tmp
, &ecn_ca
);
963 if (val
== TCP_CA_UNSPEC
)
966 val
= nla_get_u32(nla
);
968 if (type
== RTAX_ADVMSS
&& val
> 65535 - 40)
970 if (type
== RTAX_MTU
&& val
> 65535 - 15)
972 if (type
== RTAX_HOPLIMIT
&& val
> 255)
974 if (type
== RTAX_FEATURES
&& (val
& ~RTAX_FEATURE_MASK
))
976 fi
->fib_metrics
->metrics
[type
- 1] = val
;
980 fi
->fib_metrics
->metrics
[RTAX_FEATURES
- 1] |= DST_FEATURE_ECN_CA
;
985 struct fib_info
*fib_create_info(struct fib_config
*cfg
)
988 struct fib_info
*fi
= NULL
;
989 struct fib_info
*ofi
;
991 struct net
*net
= cfg
->fc_nlinfo
.nl_net
;
993 if (cfg
->fc_type
> RTN_MAX
)
996 /* Fast check to catch the most weird cases */
997 if (fib_props
[cfg
->fc_type
].scope
> cfg
->fc_scope
)
1000 if (cfg
->fc_flags
& (RTNH_F_DEAD
| RTNH_F_LINKDOWN
))
1003 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1005 nhs
= fib_count_nexthops(cfg
->fc_mp
, cfg
->fc_mp_len
);
1012 if (fib_info_cnt
>= fib_info_hash_size
) {
1013 unsigned int new_size
= fib_info_hash_size
<< 1;
1014 struct hlist_head
*new_info_hash
;
1015 struct hlist_head
*new_laddrhash
;
1020 bytes
= new_size
* sizeof(struct hlist_head
*);
1021 new_info_hash
= fib_info_hash_alloc(bytes
);
1022 new_laddrhash
= fib_info_hash_alloc(bytes
);
1023 if (!new_info_hash
|| !new_laddrhash
) {
1024 fib_info_hash_free(new_info_hash
, bytes
);
1025 fib_info_hash_free(new_laddrhash
, bytes
);
1027 fib_info_hash_move(new_info_hash
, new_laddrhash
, new_size
);
1029 if (!fib_info_hash_size
)
1033 fi
= kzalloc(sizeof(*fi
)+nhs
*sizeof(struct fib_nh
), GFP_KERNEL
);
1038 fi
->fib_metrics
= kzalloc(sizeof(*fi
->fib_metrics
), GFP_KERNEL
);
1039 if (!fi
->fib_metrics
)
1041 atomic_set(&fi
->fib_metrics
->refcnt
, 1);
1043 fi
->fib_metrics
= (struct dst_metrics
*)&dst_default_metrics
;
1046 fi
->fib_protocol
= cfg
->fc_protocol
;
1047 fi
->fib_scope
= cfg
->fc_scope
;
1048 fi
->fib_flags
= cfg
->fc_flags
;
1049 fi
->fib_priority
= cfg
->fc_priority
;
1050 fi
->fib_prefsrc
= cfg
->fc_prefsrc
;
1051 fi
->fib_type
= cfg
->fc_type
;
1052 fi
->fib_tb_id
= cfg
->fc_table
;
1055 change_nexthops(fi
) {
1056 nexthop_nh
->nh_parent
= fi
;
1057 nexthop_nh
->nh_pcpu_rth_output
= alloc_percpu(struct rtable __rcu
*);
1058 if (!nexthop_nh
->nh_pcpu_rth_output
)
1060 } endfor_nexthops(fi
)
1062 err
= fib_convert_metrics(fi
, cfg
);
1067 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1068 err
= fib_get_nhs(fi
, cfg
->fc_mp
, cfg
->fc_mp_len
, cfg
);
1071 if (cfg
->fc_oif
&& fi
->fib_nh
->nh_oif
!= cfg
->fc_oif
)
1073 if (cfg
->fc_gw
&& fi
->fib_nh
->nh_gw
!= cfg
->fc_gw
)
1075 #ifdef CONFIG_IP_ROUTE_CLASSID
1076 if (cfg
->fc_flow
&& fi
->fib_nh
->nh_tclassid
!= cfg
->fc_flow
)
1083 struct fib_nh
*nh
= fi
->fib_nh
;
1085 if (cfg
->fc_encap
) {
1086 struct lwtunnel_state
*lwtstate
;
1088 if (cfg
->fc_encap_type
== LWTUNNEL_ENCAP_NONE
)
1090 err
= lwtunnel_build_state(cfg
->fc_encap_type
,
1091 cfg
->fc_encap
, AF_INET
, cfg
,
1096 nh
->nh_lwtstate
= lwtstate_get(lwtstate
);
1098 nh
->nh_oif
= cfg
->fc_oif
;
1099 nh
->nh_gw
= cfg
->fc_gw
;
1100 nh
->nh_flags
= cfg
->fc_flags
;
1101 #ifdef CONFIG_IP_ROUTE_CLASSID
1102 nh
->nh_tclassid
= cfg
->fc_flow
;
1103 if (nh
->nh_tclassid
)
1104 fi
->fib_net
->ipv4
.fib_num_tclassid_users
++;
1106 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1111 if (fib_props
[cfg
->fc_type
].error
) {
1112 if (cfg
->fc_gw
|| cfg
->fc_oif
|| cfg
->fc_mp
)
1116 switch (cfg
->fc_type
) {
1128 if (cfg
->fc_scope
> RT_SCOPE_HOST
)
1131 if (cfg
->fc_scope
== RT_SCOPE_HOST
) {
1132 struct fib_nh
*nh
= fi
->fib_nh
;
1134 /* Local address is added. */
1135 if (nhs
!= 1 || nh
->nh_gw
)
1137 nh
->nh_scope
= RT_SCOPE_NOWHERE
;
1138 nh
->nh_dev
= dev_get_by_index(net
, fi
->fib_nh
->nh_oif
);
1145 change_nexthops(fi
) {
1146 err
= fib_check_nh(cfg
, fi
, nexthop_nh
);
1149 if (nexthop_nh
->nh_flags
& RTNH_F_LINKDOWN
)
1151 } endfor_nexthops(fi
)
1152 if (linkdown
== fi
->fib_nhs
)
1153 fi
->fib_flags
|= RTNH_F_LINKDOWN
;
1156 if (fi
->fib_prefsrc
&& !fib_valid_prefsrc(cfg
, fi
->fib_prefsrc
))
1159 change_nexthops(fi
) {
1160 fib_info_update_nh_saddr(net
, nexthop_nh
);
1161 fib_add_weight(fi
, nexthop_nh
);
1162 } endfor_nexthops(fi
)
1167 ofi
= fib_find_info(fi
);
1176 atomic_inc(&fi
->fib_clntref
);
1177 spin_lock_bh(&fib_info_lock
);
1178 hlist_add_head(&fi
->fib_hash
,
1179 &fib_info_hash
[fib_info_hashfn(fi
)]);
1180 if (fi
->fib_prefsrc
) {
1181 struct hlist_head
*head
;
1183 head
= &fib_info_laddrhash
[fib_laddr_hashfn(fi
->fib_prefsrc
)];
1184 hlist_add_head(&fi
->fib_lhash
, head
);
1186 change_nexthops(fi
) {
1187 struct hlist_head
*head
;
1190 if (!nexthop_nh
->nh_dev
)
1192 hash
= fib_devindex_hashfn(nexthop_nh
->nh_dev
->ifindex
);
1193 head
= &fib_info_devhash
[hash
];
1194 hlist_add_head(&nexthop_nh
->nh_hash
, head
);
1195 } endfor_nexthops(fi
)
1196 spin_unlock_bh(&fib_info_lock
);
1208 return ERR_PTR(err
);
1211 int fib_dump_info(struct sk_buff
*skb
, u32 portid
, u32 seq
, int event
,
1212 u32 tb_id
, u8 type
, __be32 dst
, int dst_len
, u8 tos
,
1213 struct fib_info
*fi
, unsigned int flags
)
1215 struct nlmsghdr
*nlh
;
1218 nlh
= nlmsg_put(skb
, portid
, seq
, event
, sizeof(*rtm
), flags
);
1222 rtm
= nlmsg_data(nlh
);
1223 rtm
->rtm_family
= AF_INET
;
1224 rtm
->rtm_dst_len
= dst_len
;
1225 rtm
->rtm_src_len
= 0;
1228 rtm
->rtm_table
= tb_id
;
1230 rtm
->rtm_table
= RT_TABLE_COMPAT
;
1231 if (nla_put_u32(skb
, RTA_TABLE
, tb_id
))
1232 goto nla_put_failure
;
1233 rtm
->rtm_type
= type
;
1234 rtm
->rtm_flags
= fi
->fib_flags
;
1235 rtm
->rtm_scope
= fi
->fib_scope
;
1236 rtm
->rtm_protocol
= fi
->fib_protocol
;
1238 if (rtm
->rtm_dst_len
&&
1239 nla_put_in_addr(skb
, RTA_DST
, dst
))
1240 goto nla_put_failure
;
1241 if (fi
->fib_priority
&&
1242 nla_put_u32(skb
, RTA_PRIORITY
, fi
->fib_priority
))
1243 goto nla_put_failure
;
1244 if (rtnetlink_put_metrics(skb
, fi
->fib_metrics
->metrics
) < 0)
1245 goto nla_put_failure
;
1247 if (fi
->fib_prefsrc
&&
1248 nla_put_in_addr(skb
, RTA_PREFSRC
, fi
->fib_prefsrc
))
1249 goto nla_put_failure
;
1250 if (fi
->fib_nhs
== 1) {
1251 struct in_device
*in_dev
;
1253 if (fi
->fib_nh
->nh_gw
&&
1254 nla_put_in_addr(skb
, RTA_GATEWAY
, fi
->fib_nh
->nh_gw
))
1255 goto nla_put_failure
;
1256 if (fi
->fib_nh
->nh_oif
&&
1257 nla_put_u32(skb
, RTA_OIF
, fi
->fib_nh
->nh_oif
))
1258 goto nla_put_failure
;
1259 if (fi
->fib_nh
->nh_flags
& RTNH_F_LINKDOWN
) {
1260 in_dev
= __in_dev_get_rtnl(fi
->fib_nh
->nh_dev
);
1262 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
))
1263 rtm
->rtm_flags
|= RTNH_F_DEAD
;
1265 #ifdef CONFIG_IP_ROUTE_CLASSID
1266 if (fi
->fib_nh
[0].nh_tclassid
&&
1267 nla_put_u32(skb
, RTA_FLOW
, fi
->fib_nh
[0].nh_tclassid
))
1268 goto nla_put_failure
;
1270 if (fi
->fib_nh
->nh_lwtstate
&&
1271 lwtunnel_fill_encap(skb
, fi
->fib_nh
->nh_lwtstate
) < 0)
1272 goto nla_put_failure
;
1274 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1275 if (fi
->fib_nhs
> 1) {
1276 struct rtnexthop
*rtnh
;
1279 mp
= nla_nest_start(skb
, RTA_MULTIPATH
);
1281 goto nla_put_failure
;
1284 struct in_device
*in_dev
;
1286 rtnh
= nla_reserve_nohdr(skb
, sizeof(*rtnh
));
1288 goto nla_put_failure
;
1290 rtnh
->rtnh_flags
= nh
->nh_flags
& 0xFF;
1291 if (nh
->nh_flags
& RTNH_F_LINKDOWN
) {
1292 in_dev
= __in_dev_get_rtnl(nh
->nh_dev
);
1294 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
))
1295 rtnh
->rtnh_flags
|= RTNH_F_DEAD
;
1297 rtnh
->rtnh_hops
= nh
->nh_weight
- 1;
1298 rtnh
->rtnh_ifindex
= nh
->nh_oif
;
1301 nla_put_in_addr(skb
, RTA_GATEWAY
, nh
->nh_gw
))
1302 goto nla_put_failure
;
1303 #ifdef CONFIG_IP_ROUTE_CLASSID
1304 if (nh
->nh_tclassid
&&
1305 nla_put_u32(skb
, RTA_FLOW
, nh
->nh_tclassid
))
1306 goto nla_put_failure
;
1308 if (nh
->nh_lwtstate
&&
1309 lwtunnel_fill_encap(skb
, nh
->nh_lwtstate
) < 0)
1310 goto nla_put_failure
;
1312 /* length of rtnetlink header + attributes */
1313 rtnh
->rtnh_len
= nlmsg_get_pos(skb
) - (void *) rtnh
;
1314 } endfor_nexthops(fi
);
1316 nla_nest_end(skb
, mp
);
1319 nlmsg_end(skb
, nlh
);
1323 nlmsg_cancel(skb
, nlh
);
1329 * - local address disappeared -> we must delete all the entries
1331 * - device went down -> we must shutdown all nexthops going via it.
1333 int fib_sync_down_addr(struct net_device
*dev
, __be32 local
)
1336 unsigned int hash
= fib_laddr_hashfn(local
);
1337 struct hlist_head
*head
= &fib_info_laddrhash
[hash
];
1338 struct net
*net
= dev_net(dev
);
1339 int tb_id
= l3mdev_fib_table(dev
);
1340 struct fib_info
*fi
;
1342 if (!fib_info_laddrhash
|| local
== 0)
1345 hlist_for_each_entry(fi
, head
, fib_lhash
) {
1346 if (!net_eq(fi
->fib_net
, net
) ||
1347 fi
->fib_tb_id
!= tb_id
)
1349 if (fi
->fib_prefsrc
== local
) {
1350 fi
->fib_flags
|= RTNH_F_DEAD
;
1357 static int call_fib_nh_notifiers(struct fib_nh
*fib_nh
,
1358 enum fib_event_type event_type
)
1360 struct in_device
*in_dev
= __in_dev_get_rtnl(fib_nh
->nh_dev
);
1361 struct fib_nh_notifier_info info
= {
1365 switch (event_type
) {
1366 case FIB_EVENT_NH_ADD
:
1367 if (fib_nh
->nh_flags
& RTNH_F_DEAD
)
1369 if (IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
) &&
1370 fib_nh
->nh_flags
& RTNH_F_LINKDOWN
)
1372 return call_fib_notifiers(dev_net(fib_nh
->nh_dev
), event_type
,
1374 case FIB_EVENT_NH_DEL
:
1375 if ((IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
) &&
1376 fib_nh
->nh_flags
& RTNH_F_LINKDOWN
) ||
1377 (fib_nh
->nh_flags
& RTNH_F_DEAD
))
1378 return call_fib_notifiers(dev_net(fib_nh
->nh_dev
),
1379 event_type
, &info
.info
);
1387 /* Event force Flags Description
1388 * NETDEV_CHANGE 0 LINKDOWN Carrier OFF, not for scope host
1389 * NETDEV_DOWN 0 LINKDOWN|DEAD Link down, not for scope host
1390 * NETDEV_DOWN 1 LINKDOWN|DEAD Last address removed
1391 * NETDEV_UNREGISTER 1 LINKDOWN|DEAD Device removed
1393 int fib_sync_down_dev(struct net_device
*dev
, unsigned long event
, bool force
)
1396 int scope
= RT_SCOPE_NOWHERE
;
1397 struct fib_info
*prev_fi
= NULL
;
1398 unsigned int hash
= fib_devindex_hashfn(dev
->ifindex
);
1399 struct hlist_head
*head
= &fib_info_devhash
[hash
];
1405 hlist_for_each_entry(nh
, head
, nh_hash
) {
1406 struct fib_info
*fi
= nh
->nh_parent
;
1409 BUG_ON(!fi
->fib_nhs
);
1410 if (nh
->nh_dev
!= dev
|| fi
== prev_fi
)
1414 change_nexthops(fi
) {
1415 if (nexthop_nh
->nh_flags
& RTNH_F_DEAD
)
1417 else if (nexthop_nh
->nh_dev
== dev
&&
1418 nexthop_nh
->nh_scope
!= scope
) {
1421 case NETDEV_UNREGISTER
:
1422 nexthop_nh
->nh_flags
|= RTNH_F_DEAD
;
1425 nexthop_nh
->nh_flags
|= RTNH_F_LINKDOWN
;
1428 call_fib_nh_notifiers(nexthop_nh
,
1432 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1433 if (event
== NETDEV_UNREGISTER
&&
1434 nexthop_nh
->nh_dev
== dev
) {
1439 } endfor_nexthops(fi
)
1440 if (dead
== fi
->fib_nhs
) {
1443 case NETDEV_UNREGISTER
:
1444 fi
->fib_flags
|= RTNH_F_DEAD
;
1447 fi
->fib_flags
|= RTNH_F_LINKDOWN
;
1459 /* Must be invoked inside of an RCU protected region. */
1460 static void fib_select_default(const struct flowi4
*flp
, struct fib_result
*res
)
1462 struct fib_info
*fi
= NULL
, *last_resort
= NULL
;
1463 struct hlist_head
*fa_head
= res
->fa_head
;
1464 struct fib_table
*tb
= res
->table
;
1465 u8 slen
= 32 - res
->prefixlen
;
1466 int order
= -1, last_idx
= -1;
1467 struct fib_alias
*fa
, *fa1
= NULL
;
1468 u32 last_prio
= res
->fi
->fib_priority
;
1471 hlist_for_each_entry_rcu(fa
, fa_head
, fa_list
) {
1472 struct fib_info
*next_fi
= fa
->fa_info
;
1474 if (fa
->fa_slen
!= slen
)
1476 if (fa
->fa_tos
&& fa
->fa_tos
!= flp
->flowi4_tos
)
1478 if (fa
->tb_id
!= tb
->tb_id
)
1480 if (next_fi
->fib_priority
> last_prio
&&
1481 fa
->fa_tos
== last_tos
) {
1486 if (next_fi
->fib_flags
& RTNH_F_DEAD
)
1488 last_tos
= fa
->fa_tos
;
1489 last_prio
= next_fi
->fib_priority
;
1491 if (next_fi
->fib_scope
!= res
->scope
||
1492 fa
->fa_type
!= RTN_UNICAST
)
1494 if (!next_fi
->fib_nh
[0].nh_gw
||
1495 next_fi
->fib_nh
[0].nh_scope
!= RT_SCOPE_LINK
)
1498 fib_alias_accessed(fa
);
1501 if (next_fi
!= res
->fi
)
1504 } else if (!fib_detect_death(fi
, order
, &last_resort
,
1505 &last_idx
, fa1
->fa_default
)) {
1506 fib_result_assign(res
, fi
);
1507 fa1
->fa_default
= order
;
1514 if (order
<= 0 || !fi
) {
1516 fa1
->fa_default
= -1;
1520 if (!fib_detect_death(fi
, order
, &last_resort
, &last_idx
,
1522 fib_result_assign(res
, fi
);
1523 fa1
->fa_default
= order
;
1528 fib_result_assign(res
, last_resort
);
1529 fa1
->fa_default
= last_idx
;
1535 * Dead device goes up. We wake up dead nexthops.
1536 * It takes sense only on multipath routes.
1538 int fib_sync_up(struct net_device
*dev
, unsigned int nh_flags
)
1540 struct fib_info
*prev_fi
;
1542 struct hlist_head
*head
;
1546 if (!(dev
->flags
& IFF_UP
))
1549 if (nh_flags
& RTNH_F_DEAD
) {
1550 unsigned int flags
= dev_get_flags(dev
);
1552 if (flags
& (IFF_RUNNING
| IFF_LOWER_UP
))
1553 nh_flags
|= RTNH_F_LINKDOWN
;
1557 hash
= fib_devindex_hashfn(dev
->ifindex
);
1558 head
= &fib_info_devhash
[hash
];
1561 hlist_for_each_entry(nh
, head
, nh_hash
) {
1562 struct fib_info
*fi
= nh
->nh_parent
;
1565 BUG_ON(!fi
->fib_nhs
);
1566 if (nh
->nh_dev
!= dev
|| fi
== prev_fi
)
1571 change_nexthops(fi
) {
1572 if (!(nexthop_nh
->nh_flags
& nh_flags
)) {
1576 if (!nexthop_nh
->nh_dev
||
1577 !(nexthop_nh
->nh_dev
->flags
& IFF_UP
))
1579 if (nexthop_nh
->nh_dev
!= dev
||
1580 !__in_dev_get_rtnl(dev
))
1583 nexthop_nh
->nh_flags
&= ~nh_flags
;
1584 call_fib_nh_notifiers(nexthop_nh
, FIB_EVENT_NH_ADD
);
1585 } endfor_nexthops(fi
)
1588 fi
->fib_flags
&= ~nh_flags
;
1598 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1599 static bool fib_good_nh(const struct fib_nh
*nh
)
1601 int state
= NUD_REACHABLE
;
1603 if (nh
->nh_scope
== RT_SCOPE_LINK
) {
1604 struct neighbour
*n
;
1608 n
= __ipv4_neigh_lookup_noref(nh
->nh_dev
,
1609 (__force u32
)nh
->nh_gw
);
1611 state
= n
->nud_state
;
1613 rcu_read_unlock_bh();
1616 return !!(state
& NUD_VALID
);
1619 void fib_select_multipath(struct fib_result
*res
, int hash
)
1621 struct fib_info
*fi
= res
->fi
;
1622 struct net
*net
= fi
->fib_net
;
1626 if (hash
> atomic_read(&nh
->nh_upper_bound
))
1629 if (!net
->ipv4
.sysctl_fib_multipath_use_neigh
||
1631 res
->nh_sel
= nhsel
;
1635 res
->nh_sel
= nhsel
;
1638 } endfor_nexthops(fi
);
1642 void fib_select_path(struct net
*net
, struct fib_result
*res
,
1643 struct flowi4
*fl4
, const struct sk_buff
*skb
)
1647 oif_check
= (fl4
->flowi4_oif
== 0 ||
1648 fl4
->flowi4_flags
& FLOWI_FLAG_SKIP_NH_OIF
);
1650 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1651 if (res
->fi
->fib_nhs
> 1 && oif_check
) {
1652 int h
= fib_multipath_hash(res
->fi
, fl4
, skb
);
1654 fib_select_multipath(res
, h
);
1658 if (!res
->prefixlen
&&
1659 res
->table
->tb_num_default
> 1 &&
1660 res
->type
== RTN_UNICAST
&& oif_check
)
1661 fib_select_default(fl4
, res
);
1664 fl4
->saddr
= FIB_RES_PREFSRC(net
, *res
);
1666 EXPORT_SYMBOL_GPL(fib_select_path
);