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 <asm/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 static DEFINE_SPINLOCK(fib_multipath_lock
);
63 #define for_nexthops(fi) { \
64 int nhsel; const struct fib_nh *nh; \
65 for (nhsel = 0, nh = (fi)->fib_nh; \
66 nhsel < (fi)->fib_nhs; \
69 #define change_nexthops(fi) { \
70 int nhsel; struct fib_nh *nexthop_nh; \
71 for (nhsel = 0, nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
72 nhsel < (fi)->fib_nhs; \
73 nexthop_nh++, nhsel++)
75 #else /* CONFIG_IP_ROUTE_MULTIPATH */
77 /* Hope, that gcc will optimize it to get rid of dummy loop */
79 #define for_nexthops(fi) { \
80 int nhsel; const struct fib_nh *nh = (fi)->fib_nh; \
81 for (nhsel = 0; nhsel < 1; nhsel++)
83 #define change_nexthops(fi) { \
85 struct fib_nh *nexthop_nh = (struct fib_nh *)((fi)->fib_nh); \
86 for (nhsel = 0; nhsel < 1; nhsel++)
88 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
90 #define endfor_nexthops(fi) }
93 const struct fib_prop fib_props
[RTN_MAX
+ 1] = {
96 .scope
= RT_SCOPE_NOWHERE
,
100 .scope
= RT_SCOPE_UNIVERSE
,
104 .scope
= RT_SCOPE_HOST
,
108 .scope
= RT_SCOPE_LINK
,
112 .scope
= RT_SCOPE_LINK
,
116 .scope
= RT_SCOPE_UNIVERSE
,
120 .scope
= RT_SCOPE_UNIVERSE
,
122 [RTN_UNREACHABLE
] = {
123 .error
= -EHOSTUNREACH
,
124 .scope
= RT_SCOPE_UNIVERSE
,
128 .scope
= RT_SCOPE_UNIVERSE
,
132 .scope
= RT_SCOPE_UNIVERSE
,
136 .scope
= RT_SCOPE_NOWHERE
,
140 .scope
= RT_SCOPE_NOWHERE
,
144 static void rt_fibinfo_free(struct rtable __rcu
**rtp
)
146 struct rtable
*rt
= rcu_dereference_protected(*rtp
, 1);
151 /* Not even needed : RCU_INIT_POINTER(*rtp, NULL);
152 * because we waited an RCU grace period before calling
153 * free_fib_info_rcu()
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);
204 /* Release a nexthop info record */
205 static void free_fib_info_rcu(struct rcu_head
*head
)
207 struct fib_info
*fi
= container_of(head
, struct fib_info
, rcu
);
209 change_nexthops(fi
) {
210 if (nexthop_nh
->nh_dev
)
211 dev_put(nexthop_nh
->nh_dev
);
212 lwtstate_put(nexthop_nh
->nh_lwtstate
);
213 free_nh_exceptions(nexthop_nh
);
214 rt_fibinfo_free_cpus(nexthop_nh
->nh_pcpu_rth_output
);
215 rt_fibinfo_free(&nexthop_nh
->nh_rth_input
);
216 } endfor_nexthops(fi
);
218 if (fi
->fib_metrics
!= (u32
*) dst_default_metrics
)
219 kfree(fi
->fib_metrics
);
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
);
239 void fib_release_info(struct fib_info
*fi
)
241 spin_lock_bh(&fib_info_lock
);
242 if (fi
&& --fi
->fib_treeref
== 0) {
243 hlist_del(&fi
->fib_hash
);
245 hlist_del(&fi
->fib_lhash
);
246 change_nexthops(fi
) {
247 if (!nexthop_nh
->nh_dev
)
249 hlist_del(&nexthop_nh
->nh_hash
);
250 } endfor_nexthops(fi
)
254 spin_unlock_bh(&fib_info_lock
);
257 static inline int nh_comp(const struct fib_info
*fi
, const struct fib_info
*ofi
)
259 const struct fib_nh
*onh
= ofi
->fib_nh
;
262 if (nh
->nh_oif
!= onh
->nh_oif
||
263 nh
->nh_gw
!= onh
->nh_gw
||
264 nh
->nh_scope
!= onh
->nh_scope
||
265 #ifdef CONFIG_IP_ROUTE_MULTIPATH
266 nh
->nh_weight
!= onh
->nh_weight
||
268 #ifdef CONFIG_IP_ROUTE_CLASSID
269 nh
->nh_tclassid
!= onh
->nh_tclassid
||
271 lwtunnel_cmp_encap(nh
->nh_lwtstate
, onh
->nh_lwtstate
) ||
272 ((nh
->nh_flags
^ onh
->nh_flags
) & ~RTNH_COMPARE_MASK
))
275 } endfor_nexthops(fi
);
279 static inline unsigned int fib_devindex_hashfn(unsigned int val
)
281 unsigned int mask
= DEVINDEX_HASHSIZE
- 1;
284 (val
>> DEVINDEX_HASHBITS
) ^
285 (val
>> (DEVINDEX_HASHBITS
* 2))) & mask
;
288 static inline unsigned int fib_info_hashfn(const struct fib_info
*fi
)
290 unsigned int mask
= (fib_info_hash_size
- 1);
291 unsigned int val
= fi
->fib_nhs
;
293 val
^= (fi
->fib_protocol
<< 8) | fi
->fib_scope
;
294 val
^= (__force u32
)fi
->fib_prefsrc
;
295 val
^= fi
->fib_priority
;
297 val
^= fib_devindex_hashfn(nh
->nh_oif
);
298 } endfor_nexthops(fi
)
300 return (val
^ (val
>> 7) ^ (val
>> 12)) & mask
;
303 static struct fib_info
*fib_find_info(const struct fib_info
*nfi
)
305 struct hlist_head
*head
;
309 hash
= fib_info_hashfn(nfi
);
310 head
= &fib_info_hash
[hash
];
312 hlist_for_each_entry(fi
, head
, fib_hash
) {
313 if (!net_eq(fi
->fib_net
, nfi
->fib_net
))
315 if (fi
->fib_nhs
!= nfi
->fib_nhs
)
317 if (nfi
->fib_protocol
== fi
->fib_protocol
&&
318 nfi
->fib_scope
== fi
->fib_scope
&&
319 nfi
->fib_prefsrc
== fi
->fib_prefsrc
&&
320 nfi
->fib_priority
== fi
->fib_priority
&&
321 nfi
->fib_type
== fi
->fib_type
&&
322 memcmp(nfi
->fib_metrics
, fi
->fib_metrics
,
323 sizeof(u32
) * RTAX_MAX
) == 0 &&
324 !((nfi
->fib_flags
^ fi
->fib_flags
) & ~RTNH_COMPARE_MASK
) &&
325 (nfi
->fib_nhs
== 0 || nh_comp(fi
, nfi
) == 0))
332 /* Check, that the gateway is already configured.
333 * Used only by redirect accept routine.
335 int ip_fib_check_default(__be32 gw
, struct net_device
*dev
)
337 struct hlist_head
*head
;
341 spin_lock(&fib_info_lock
);
343 hash
= fib_devindex_hashfn(dev
->ifindex
);
344 head
= &fib_info_devhash
[hash
];
345 hlist_for_each_entry(nh
, head
, nh_hash
) {
346 if (nh
->nh_dev
== dev
&&
348 !(nh
->nh_flags
& RTNH_F_DEAD
)) {
349 spin_unlock(&fib_info_lock
);
354 spin_unlock(&fib_info_lock
);
359 static inline size_t fib_nlmsg_size(struct fib_info
*fi
)
361 size_t payload
= NLMSG_ALIGN(sizeof(struct rtmsg
))
362 + nla_total_size(4) /* RTA_TABLE */
363 + nla_total_size(4) /* RTA_DST */
364 + nla_total_size(4) /* RTA_PRIORITY */
365 + nla_total_size(4) /* RTA_PREFSRC */
366 + nla_total_size(TCP_CA_NAME_MAX
); /* RTAX_CC_ALGO */
368 /* space for nested metrics */
369 payload
+= nla_total_size((RTAX_MAX
* nla_total_size(4)));
372 size_t nh_encapsize
= 0;
373 /* Also handles the special case fib_nhs == 1 */
375 /* each nexthop is packed in an attribute */
376 size_t nhsize
= nla_total_size(sizeof(struct rtnexthop
));
378 /* may contain flow and gateway attribute */
379 nhsize
+= 2 * nla_total_size(4);
381 /* grab encap info */
383 if (nh
->nh_lwtstate
) {
385 nh_encapsize
+= lwtunnel_get_encap_size(
388 nh_encapsize
+= nla_total_size(2);
390 } endfor_nexthops(fi
);
392 /* all nexthops are packed in a nested attribute */
393 payload
+= nla_total_size((fi
->fib_nhs
* nhsize
) +
401 void rtmsg_fib(int event
, __be32 key
, struct fib_alias
*fa
,
402 int dst_len
, u32 tb_id
, const struct nl_info
*info
,
403 unsigned int nlm_flags
)
406 u32 seq
= info
->nlh
? info
->nlh
->nlmsg_seq
: 0;
409 skb
= nlmsg_new(fib_nlmsg_size(fa
->fa_info
), GFP_KERNEL
);
413 err
= fib_dump_info(skb
, info
->portid
, seq
, event
, tb_id
,
414 fa
->fa_type
, key
, dst_len
,
415 fa
->fa_tos
, fa
->fa_info
, nlm_flags
);
417 /* -EMSGSIZE implies BUG in fib_nlmsg_size() */
418 WARN_ON(err
== -EMSGSIZE
);
422 rtnl_notify(skb
, info
->nl_net
, info
->portid
, RTNLGRP_IPV4_ROUTE
,
423 info
->nlh
, GFP_KERNEL
);
427 rtnl_set_sk_err(info
->nl_net
, RTNLGRP_IPV4_ROUTE
, err
);
430 static int fib_detect_death(struct fib_info
*fi
, int order
,
431 struct fib_info
**last_resort
, int *last_idx
,
435 int state
= NUD_NONE
;
437 n
= neigh_lookup(&arp_tbl
, &fi
->fib_nh
[0].nh_gw
, fi
->fib_dev
);
439 state
= n
->nud_state
;
444 if (state
== NUD_REACHABLE
)
446 if ((state
& NUD_VALID
) && order
!= dflt
)
448 if ((state
& NUD_VALID
) ||
449 (*last_idx
< 0 && order
> dflt
&& state
!= NUD_INCOMPLETE
)) {
456 #ifdef CONFIG_IP_ROUTE_MULTIPATH
458 static int fib_count_nexthops(struct rtnexthop
*rtnh
, int remaining
)
462 while (rtnh_ok(rtnh
, remaining
)) {
464 rtnh
= rtnh_next(rtnh
, &remaining
);
467 /* leftover implies invalid nexthop configuration, discard it */
468 return remaining
> 0 ? 0 : nhs
;
471 static int fib_get_nhs(struct fib_info
*fi
, struct rtnexthop
*rtnh
,
472 int remaining
, struct fib_config
*cfg
)
474 struct net
*net
= cfg
->fc_nlinfo
.nl_net
;
477 change_nexthops(fi
) {
480 if (!rtnh_ok(rtnh
, remaining
))
483 nexthop_nh
->nh_flags
=
484 (cfg
->fc_flags
& ~0xFF) | rtnh
->rtnh_flags
;
485 nexthop_nh
->nh_oif
= rtnh
->rtnh_ifindex
;
486 nexthop_nh
->nh_weight
= rtnh
->rtnh_hops
+ 1;
488 attrlen
= rtnh_attrlen(rtnh
);
490 struct nlattr
*nla
, *attrs
= rtnh_attrs(rtnh
);
492 nla
= nla_find(attrs
, attrlen
, RTA_GATEWAY
);
493 nexthop_nh
->nh_gw
= nla
? nla_get_in_addr(nla
) : 0;
494 #ifdef CONFIG_IP_ROUTE_CLASSID
495 nla
= nla_find(attrs
, attrlen
, RTA_FLOW
);
496 nexthop_nh
->nh_tclassid
= nla
? nla_get_u32(nla
) : 0;
497 if (nexthop_nh
->nh_tclassid
)
498 fi
->fib_net
->ipv4
.fib_num_tclassid_users
++;
500 nla
= nla_find(attrs
, attrlen
, RTA_ENCAP
);
502 struct lwtunnel_state
*lwtstate
;
503 struct net_device
*dev
= NULL
;
504 struct nlattr
*nla_entype
;
506 nla_entype
= nla_find(attrs
, attrlen
,
511 dev
= __dev_get_by_index(net
, cfg
->fc_oif
);
512 ret
= lwtunnel_build_state(dev
, nla_get_u16(
517 nexthop_nh
->nh_lwtstate
=
518 lwtstate_get(lwtstate
);
522 rtnh
= rtnh_next(rtnh
, &remaining
);
523 } endfor_nexthops(fi
);
536 int fib_encap_match(struct net
*net
, u16 encap_type
,
537 struct nlattr
*encap
,
538 int oif
, const struct fib_nh
*nh
)
540 struct lwtunnel_state
*lwtstate
;
541 struct net_device
*dev
= NULL
;
544 if (encap_type
== LWTUNNEL_ENCAP_NONE
)
548 dev
= __dev_get_by_index(net
, oif
);
549 ret
= lwtunnel_build_state(dev
, encap_type
,
552 return lwtunnel_cmp_encap(lwtstate
, nh
->nh_lwtstate
);
557 int fib_nh_match(struct fib_config
*cfg
, struct fib_info
*fi
)
559 struct net
*net
= cfg
->fc_nlinfo
.nl_net
;
560 #ifdef CONFIG_IP_ROUTE_MULTIPATH
561 struct rtnexthop
*rtnh
;
565 if (cfg
->fc_priority
&& cfg
->fc_priority
!= fi
->fib_priority
)
568 if (cfg
->fc_oif
|| cfg
->fc_gw
) {
570 if (fib_encap_match(net
, cfg
->fc_encap_type
,
571 cfg
->fc_encap
, cfg
->fc_oif
,
575 if ((!cfg
->fc_oif
|| cfg
->fc_oif
== fi
->fib_nh
->nh_oif
) &&
576 (!cfg
->fc_gw
|| cfg
->fc_gw
== fi
->fib_nh
->nh_gw
))
581 #ifdef CONFIG_IP_ROUTE_MULTIPATH
586 remaining
= cfg
->fc_mp_len
;
591 if (!rtnh_ok(rtnh
, remaining
))
594 if (rtnh
->rtnh_ifindex
&& rtnh
->rtnh_ifindex
!= nh
->nh_oif
)
597 attrlen
= rtnh_attrlen(rtnh
);
599 struct nlattr
*nla
, *attrs
= rtnh_attrs(rtnh
);
601 nla
= nla_find(attrs
, attrlen
, RTA_GATEWAY
);
602 if (nla
&& nla_get_in_addr(nla
) != nh
->nh_gw
)
604 #ifdef CONFIG_IP_ROUTE_CLASSID
605 nla
= nla_find(attrs
, attrlen
, RTA_FLOW
);
606 if (nla
&& nla_get_u32(nla
) != nh
->nh_tclassid
)
611 rtnh
= rtnh_next(rtnh
, &remaining
);
612 } endfor_nexthops(fi
);
622 * Semantics of nexthop is very messy by historical reasons.
623 * We have to take into account, that:
624 * a) gateway can be actually local interface address,
625 * so that gatewayed route is direct.
626 * b) gateway must be on-link address, possibly
627 * described not by an ifaddr, but also by a direct route.
628 * c) If both gateway and interface are specified, they should not
630 * d) If we use tunnel routes, gateway could be not on-link.
632 * Attempt to reconcile all of these (alas, self-contradictory) conditions
633 * results in pretty ugly and hairy code with obscure logic.
635 * I chose to generalized it instead, so that the size
636 * of code does not increase practically, but it becomes
638 * Every prefix is assigned a "scope" value: "host" is local address,
639 * "link" is direct route,
640 * [ ... "site" ... "interior" ... ]
641 * and "universe" is true gateway route with global meaning.
643 * Every prefix refers to a set of "nexthop"s (gw, oif),
644 * where gw must have narrower scope. This recursion stops
645 * when gw has LOCAL scope or if "nexthop" is declared ONLINK,
646 * which means that gw is forced to be on link.
648 * Code is still hairy, but now it is apparently logically
649 * consistent and very flexible. F.e. as by-product it allows
650 * to co-exists in peace independent exterior and interior
653 * Normally it looks as following.
655 * {universe prefix} -> (gw, oif) [scope link]
657 * |-> {link prefix} -> (gw, oif) [scope local]
659 * |-> {local prefix} (terminal node)
661 static int fib_check_nh(struct fib_config
*cfg
, struct fib_info
*fi
,
666 struct net_device
*dev
;
668 net
= cfg
->fc_nlinfo
.nl_net
;
670 struct fib_result res
;
672 if (nh
->nh_flags
& RTNH_F_ONLINK
) {
673 unsigned int addr_type
;
675 if (cfg
->fc_scope
>= RT_SCOPE_LINK
)
677 dev
= __dev_get_by_index(net
, nh
->nh_oif
);
680 if (!(dev
->flags
& IFF_UP
))
682 addr_type
= inet_addr_type_dev_table(net
, dev
, nh
->nh_gw
);
683 if (addr_type
!= RTN_UNICAST
)
685 if (!netif_carrier_ok(dev
))
686 nh
->nh_flags
|= RTNH_F_LINKDOWN
;
689 nh
->nh_scope
= RT_SCOPE_LINK
;
694 struct flowi4 fl4
= {
696 .flowi4_scope
= cfg
->fc_scope
+ 1,
697 .flowi4_oif
= nh
->nh_oif
,
698 .flowi4_iif
= LOOPBACK_IFINDEX
,
701 /* It is not necessary, but requires a bit of thinking */
702 if (fl4
.flowi4_scope
< RT_SCOPE_LINK
)
703 fl4
.flowi4_scope
= RT_SCOPE_LINK
;
704 err
= fib_lookup(net
, &fl4
, &res
,
705 FIB_LOOKUP_IGNORE_LINKSTATE
);
712 if (res
.type
!= RTN_UNICAST
&& res
.type
!= RTN_LOCAL
)
714 nh
->nh_scope
= res
.scope
;
715 nh
->nh_oif
= FIB_RES_OIF(res
);
716 nh
->nh_dev
= dev
= FIB_RES_DEV(res
);
720 if (!netif_carrier_ok(dev
))
721 nh
->nh_flags
|= RTNH_F_LINKDOWN
;
722 err
= (dev
->flags
& IFF_UP
) ? 0 : -ENETDOWN
;
724 struct in_device
*in_dev
;
726 if (nh
->nh_flags
& (RTNH_F_PERVASIVE
| RTNH_F_ONLINK
))
731 in_dev
= inetdev_by_index(net
, nh
->nh_oif
);
735 if (!(in_dev
->dev
->flags
& IFF_UP
))
737 nh
->nh_dev
= in_dev
->dev
;
738 dev_hold(nh
->nh_dev
);
739 nh
->nh_scope
= RT_SCOPE_HOST
;
740 if (!netif_carrier_ok(nh
->nh_dev
))
741 nh
->nh_flags
|= RTNH_F_LINKDOWN
;
749 static inline unsigned int fib_laddr_hashfn(__be32 val
)
751 unsigned int mask
= (fib_info_hash_size
- 1);
753 return ((__force u32
)val
^
754 ((__force u32
)val
>> 7) ^
755 ((__force u32
)val
>> 14)) & mask
;
758 static struct hlist_head
*fib_info_hash_alloc(int bytes
)
760 if (bytes
<= PAGE_SIZE
)
761 return kzalloc(bytes
, GFP_KERNEL
);
763 return (struct hlist_head
*)
764 __get_free_pages(GFP_KERNEL
| __GFP_ZERO
,
768 static void fib_info_hash_free(struct hlist_head
*hash
, int bytes
)
773 if (bytes
<= PAGE_SIZE
)
776 free_pages((unsigned long) hash
, get_order(bytes
));
779 static void fib_info_hash_move(struct hlist_head
*new_info_hash
,
780 struct hlist_head
*new_laddrhash
,
781 unsigned int new_size
)
783 struct hlist_head
*old_info_hash
, *old_laddrhash
;
784 unsigned int old_size
= fib_info_hash_size
;
785 unsigned int i
, bytes
;
787 spin_lock_bh(&fib_info_lock
);
788 old_info_hash
= fib_info_hash
;
789 old_laddrhash
= fib_info_laddrhash
;
790 fib_info_hash_size
= new_size
;
792 for (i
= 0; i
< old_size
; i
++) {
793 struct hlist_head
*head
= &fib_info_hash
[i
];
794 struct hlist_node
*n
;
797 hlist_for_each_entry_safe(fi
, n
, head
, fib_hash
) {
798 struct hlist_head
*dest
;
799 unsigned int new_hash
;
801 new_hash
= fib_info_hashfn(fi
);
802 dest
= &new_info_hash
[new_hash
];
803 hlist_add_head(&fi
->fib_hash
, dest
);
806 fib_info_hash
= new_info_hash
;
808 for (i
= 0; i
< old_size
; i
++) {
809 struct hlist_head
*lhead
= &fib_info_laddrhash
[i
];
810 struct hlist_node
*n
;
813 hlist_for_each_entry_safe(fi
, n
, lhead
, fib_lhash
) {
814 struct hlist_head
*ldest
;
815 unsigned int new_hash
;
817 new_hash
= fib_laddr_hashfn(fi
->fib_prefsrc
);
818 ldest
= &new_laddrhash
[new_hash
];
819 hlist_add_head(&fi
->fib_lhash
, ldest
);
822 fib_info_laddrhash
= new_laddrhash
;
824 spin_unlock_bh(&fib_info_lock
);
826 bytes
= old_size
* sizeof(struct hlist_head
*);
827 fib_info_hash_free(old_info_hash
, bytes
);
828 fib_info_hash_free(old_laddrhash
, bytes
);
831 __be32
fib_info_update_nh_saddr(struct net
*net
, struct fib_nh
*nh
)
833 nh
->nh_saddr
= inet_select_addr(nh
->nh_dev
,
835 nh
->nh_parent
->fib_scope
);
836 nh
->nh_saddr_genid
= atomic_read(&net
->ipv4
.dev_addr_genid
);
841 static bool fib_valid_prefsrc(struct fib_config
*cfg
, __be32 fib_prefsrc
)
843 if (cfg
->fc_type
!= RTN_LOCAL
|| !cfg
->fc_dst
||
844 fib_prefsrc
!= cfg
->fc_dst
) {
845 int tb_id
= cfg
->fc_table
;
847 if (tb_id
== RT_TABLE_MAIN
)
848 tb_id
= RT_TABLE_LOCAL
;
850 if (inet_addr_type_table(cfg
->fc_nlinfo
.nl_net
,
851 fib_prefsrc
, tb_id
) != RTN_LOCAL
) {
858 struct fib_info
*fib_create_info(struct fib_config
*cfg
)
861 struct fib_info
*fi
= NULL
;
862 struct fib_info
*ofi
;
864 struct net
*net
= cfg
->fc_nlinfo
.nl_net
;
866 if (cfg
->fc_type
> RTN_MAX
)
869 /* Fast check to catch the most weird cases */
870 if (fib_props
[cfg
->fc_type
].scope
> cfg
->fc_scope
)
873 #ifdef CONFIG_IP_ROUTE_MULTIPATH
875 nhs
= fib_count_nexthops(cfg
->fc_mp
, cfg
->fc_mp_len
);
882 if (fib_info_cnt
>= fib_info_hash_size
) {
883 unsigned int new_size
= fib_info_hash_size
<< 1;
884 struct hlist_head
*new_info_hash
;
885 struct hlist_head
*new_laddrhash
;
890 bytes
= new_size
* sizeof(struct hlist_head
*);
891 new_info_hash
= fib_info_hash_alloc(bytes
);
892 new_laddrhash
= fib_info_hash_alloc(bytes
);
893 if (!new_info_hash
|| !new_laddrhash
) {
894 fib_info_hash_free(new_info_hash
, bytes
);
895 fib_info_hash_free(new_laddrhash
, bytes
);
897 fib_info_hash_move(new_info_hash
, new_laddrhash
, new_size
);
899 if (!fib_info_hash_size
)
903 fi
= kzalloc(sizeof(*fi
)+nhs
*sizeof(struct fib_nh
), GFP_KERNEL
);
908 fi
->fib_metrics
= kzalloc(sizeof(u32
) * RTAX_MAX
, GFP_KERNEL
);
909 if (!fi
->fib_metrics
)
912 fi
->fib_metrics
= (u32
*) dst_default_metrics
;
915 fi
->fib_protocol
= cfg
->fc_protocol
;
916 fi
->fib_scope
= cfg
->fc_scope
;
917 fi
->fib_flags
= cfg
->fc_flags
;
918 fi
->fib_priority
= cfg
->fc_priority
;
919 fi
->fib_prefsrc
= cfg
->fc_prefsrc
;
920 fi
->fib_type
= cfg
->fc_type
;
923 change_nexthops(fi
) {
924 nexthop_nh
->nh_parent
= fi
;
925 nexthop_nh
->nh_pcpu_rth_output
= alloc_percpu(struct rtable __rcu
*);
926 if (!nexthop_nh
->nh_pcpu_rth_output
)
928 } endfor_nexthops(fi
)
934 nla_for_each_attr(nla
, cfg
->fc_mx
, cfg
->fc_mx_len
, remaining
) {
935 int type
= nla_type(nla
);
942 if (type
== RTAX_CC_ALGO
) {
943 char tmp
[TCP_CA_NAME_MAX
];
945 nla_strlcpy(tmp
, nla
, sizeof(tmp
));
946 val
= tcp_ca_get_key_by_name(tmp
);
947 if (val
== TCP_CA_UNSPEC
)
950 val
= nla_get_u32(nla
);
952 if (type
== RTAX_ADVMSS
&& val
> 65535 - 40)
954 if (type
== RTAX_MTU
&& val
> 65535 - 15)
956 fi
->fib_metrics
[type
- 1] = val
;
962 #ifdef CONFIG_IP_ROUTE_MULTIPATH
963 err
= fib_get_nhs(fi
, cfg
->fc_mp
, cfg
->fc_mp_len
, cfg
);
966 if (cfg
->fc_oif
&& fi
->fib_nh
->nh_oif
!= cfg
->fc_oif
)
968 if (cfg
->fc_gw
&& fi
->fib_nh
->nh_gw
!= cfg
->fc_gw
)
970 #ifdef CONFIG_IP_ROUTE_CLASSID
971 if (cfg
->fc_flow
&& fi
->fib_nh
->nh_tclassid
!= cfg
->fc_flow
)
978 struct fib_nh
*nh
= fi
->fib_nh
;
981 struct lwtunnel_state
*lwtstate
;
982 struct net_device
*dev
= NULL
;
984 if (cfg
->fc_encap_type
== LWTUNNEL_ENCAP_NONE
)
987 dev
= __dev_get_by_index(net
, cfg
->fc_oif
);
988 err
= lwtunnel_build_state(dev
, cfg
->fc_encap_type
,
989 cfg
->fc_encap
, &lwtstate
);
993 nh
->nh_lwtstate
= lwtstate_get(lwtstate
);
995 nh
->nh_oif
= cfg
->fc_oif
;
996 nh
->nh_gw
= cfg
->fc_gw
;
997 nh
->nh_flags
= cfg
->fc_flags
;
998 #ifdef CONFIG_IP_ROUTE_CLASSID
999 nh
->nh_tclassid
= cfg
->fc_flow
;
1000 if (nh
->nh_tclassid
)
1001 fi
->fib_net
->ipv4
.fib_num_tclassid_users
++;
1003 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1008 if (fib_props
[cfg
->fc_type
].error
) {
1009 if (cfg
->fc_gw
|| cfg
->fc_oif
|| cfg
->fc_mp
)
1013 switch (cfg
->fc_type
) {
1025 if (cfg
->fc_scope
> RT_SCOPE_HOST
)
1028 if (cfg
->fc_scope
== RT_SCOPE_HOST
) {
1029 struct fib_nh
*nh
= fi
->fib_nh
;
1031 /* Local address is added. */
1032 if (nhs
!= 1 || nh
->nh_gw
)
1034 nh
->nh_scope
= RT_SCOPE_NOWHERE
;
1035 nh
->nh_dev
= dev_get_by_index(net
, fi
->fib_nh
->nh_oif
);
1042 change_nexthops(fi
) {
1043 err
= fib_check_nh(cfg
, fi
, nexthop_nh
);
1046 if (nexthop_nh
->nh_flags
& RTNH_F_LINKDOWN
)
1048 } endfor_nexthops(fi
)
1049 if (linkdown
== fi
->fib_nhs
)
1050 fi
->fib_flags
|= RTNH_F_LINKDOWN
;
1053 if (fi
->fib_prefsrc
&& !fib_valid_prefsrc(cfg
, fi
->fib_prefsrc
))
1056 change_nexthops(fi
) {
1057 fib_info_update_nh_saddr(net
, nexthop_nh
);
1058 } endfor_nexthops(fi
)
1061 ofi
= fib_find_info(fi
);
1070 atomic_inc(&fi
->fib_clntref
);
1071 spin_lock_bh(&fib_info_lock
);
1072 hlist_add_head(&fi
->fib_hash
,
1073 &fib_info_hash
[fib_info_hashfn(fi
)]);
1074 if (fi
->fib_prefsrc
) {
1075 struct hlist_head
*head
;
1077 head
= &fib_info_laddrhash
[fib_laddr_hashfn(fi
->fib_prefsrc
)];
1078 hlist_add_head(&fi
->fib_lhash
, head
);
1080 change_nexthops(fi
) {
1081 struct hlist_head
*head
;
1084 if (!nexthop_nh
->nh_dev
)
1086 hash
= fib_devindex_hashfn(nexthop_nh
->nh_dev
->ifindex
);
1087 head
= &fib_info_devhash
[hash
];
1088 hlist_add_head(&nexthop_nh
->nh_hash
, head
);
1089 } endfor_nexthops(fi
)
1090 spin_unlock_bh(&fib_info_lock
);
1102 return ERR_PTR(err
);
1105 int fib_dump_info(struct sk_buff
*skb
, u32 portid
, u32 seq
, int event
,
1106 u32 tb_id
, u8 type
, __be32 dst
, int dst_len
, u8 tos
,
1107 struct fib_info
*fi
, unsigned int flags
)
1109 struct nlmsghdr
*nlh
;
1112 nlh
= nlmsg_put(skb
, portid
, seq
, event
, sizeof(*rtm
), flags
);
1116 rtm
= nlmsg_data(nlh
);
1117 rtm
->rtm_family
= AF_INET
;
1118 rtm
->rtm_dst_len
= dst_len
;
1119 rtm
->rtm_src_len
= 0;
1122 rtm
->rtm_table
= tb_id
;
1124 rtm
->rtm_table
= RT_TABLE_COMPAT
;
1125 if (nla_put_u32(skb
, RTA_TABLE
, tb_id
))
1126 goto nla_put_failure
;
1127 rtm
->rtm_type
= type
;
1128 rtm
->rtm_flags
= fi
->fib_flags
;
1129 rtm
->rtm_scope
= fi
->fib_scope
;
1130 rtm
->rtm_protocol
= fi
->fib_protocol
;
1132 if (rtm
->rtm_dst_len
&&
1133 nla_put_in_addr(skb
, RTA_DST
, dst
))
1134 goto nla_put_failure
;
1135 if (fi
->fib_priority
&&
1136 nla_put_u32(skb
, RTA_PRIORITY
, fi
->fib_priority
))
1137 goto nla_put_failure
;
1138 if (rtnetlink_put_metrics(skb
, fi
->fib_metrics
) < 0)
1139 goto nla_put_failure
;
1141 if (fi
->fib_prefsrc
&&
1142 nla_put_in_addr(skb
, RTA_PREFSRC
, fi
->fib_prefsrc
))
1143 goto nla_put_failure
;
1144 if (fi
->fib_nhs
== 1) {
1145 struct in_device
*in_dev
;
1147 if (fi
->fib_nh
->nh_gw
&&
1148 nla_put_in_addr(skb
, RTA_GATEWAY
, fi
->fib_nh
->nh_gw
))
1149 goto nla_put_failure
;
1150 if (fi
->fib_nh
->nh_oif
&&
1151 nla_put_u32(skb
, RTA_OIF
, fi
->fib_nh
->nh_oif
))
1152 goto nla_put_failure
;
1153 if (fi
->fib_nh
->nh_flags
& RTNH_F_LINKDOWN
) {
1154 in_dev
= __in_dev_get_rtnl(fi
->fib_nh
->nh_dev
);
1156 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
))
1157 rtm
->rtm_flags
|= RTNH_F_DEAD
;
1159 #ifdef CONFIG_IP_ROUTE_CLASSID
1160 if (fi
->fib_nh
[0].nh_tclassid
&&
1161 nla_put_u32(skb
, RTA_FLOW
, fi
->fib_nh
[0].nh_tclassid
))
1162 goto nla_put_failure
;
1164 if (fi
->fib_nh
->nh_lwtstate
)
1165 lwtunnel_fill_encap(skb
, fi
->fib_nh
->nh_lwtstate
);
1167 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1168 if (fi
->fib_nhs
> 1) {
1169 struct rtnexthop
*rtnh
;
1172 mp
= nla_nest_start(skb
, RTA_MULTIPATH
);
1174 goto nla_put_failure
;
1177 struct in_device
*in_dev
;
1179 rtnh
= nla_reserve_nohdr(skb
, sizeof(*rtnh
));
1181 goto nla_put_failure
;
1183 rtnh
->rtnh_flags
= nh
->nh_flags
& 0xFF;
1184 if (nh
->nh_flags
& RTNH_F_LINKDOWN
) {
1185 in_dev
= __in_dev_get_rtnl(nh
->nh_dev
);
1187 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
))
1188 rtnh
->rtnh_flags
|= RTNH_F_DEAD
;
1190 rtnh
->rtnh_hops
= nh
->nh_weight
- 1;
1191 rtnh
->rtnh_ifindex
= nh
->nh_oif
;
1194 nla_put_in_addr(skb
, RTA_GATEWAY
, nh
->nh_gw
))
1195 goto nla_put_failure
;
1196 #ifdef CONFIG_IP_ROUTE_CLASSID
1197 if (nh
->nh_tclassid
&&
1198 nla_put_u32(skb
, RTA_FLOW
, nh
->nh_tclassid
))
1199 goto nla_put_failure
;
1201 if (nh
->nh_lwtstate
)
1202 lwtunnel_fill_encap(skb
, nh
->nh_lwtstate
);
1203 /* length of rtnetlink header + attributes */
1204 rtnh
->rtnh_len
= nlmsg_get_pos(skb
) - (void *) rtnh
;
1205 } endfor_nexthops(fi
);
1207 nla_nest_end(skb
, mp
);
1210 nlmsg_end(skb
, nlh
);
1214 nlmsg_cancel(skb
, nlh
);
1220 * - local address disappeared -> we must delete all the entries
1222 * - device went down -> we must shutdown all nexthops going via it.
1224 int fib_sync_down_addr(struct net
*net
, __be32 local
)
1227 unsigned int hash
= fib_laddr_hashfn(local
);
1228 struct hlist_head
*head
= &fib_info_laddrhash
[hash
];
1229 struct fib_info
*fi
;
1231 if (!fib_info_laddrhash
|| local
== 0)
1234 hlist_for_each_entry(fi
, head
, fib_lhash
) {
1235 if (!net_eq(fi
->fib_net
, net
))
1237 if (fi
->fib_prefsrc
== local
) {
1238 fi
->fib_flags
|= RTNH_F_DEAD
;
1245 int fib_sync_down_dev(struct net_device
*dev
, unsigned long event
)
1248 int scope
= RT_SCOPE_NOWHERE
;
1249 struct fib_info
*prev_fi
= NULL
;
1250 unsigned int hash
= fib_devindex_hashfn(dev
->ifindex
);
1251 struct hlist_head
*head
= &fib_info_devhash
[hash
];
1254 if (event
== NETDEV_UNREGISTER
||
1255 event
== NETDEV_DOWN
)
1258 hlist_for_each_entry(nh
, head
, nh_hash
) {
1259 struct fib_info
*fi
= nh
->nh_parent
;
1262 BUG_ON(!fi
->fib_nhs
);
1263 if (nh
->nh_dev
!= dev
|| fi
== prev_fi
)
1267 change_nexthops(fi
) {
1268 if (nexthop_nh
->nh_flags
& RTNH_F_DEAD
)
1270 else if (nexthop_nh
->nh_dev
== dev
&&
1271 nexthop_nh
->nh_scope
!= scope
) {
1274 case NETDEV_UNREGISTER
:
1275 nexthop_nh
->nh_flags
|= RTNH_F_DEAD
;
1278 nexthop_nh
->nh_flags
|= RTNH_F_LINKDOWN
;
1281 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1282 spin_lock_bh(&fib_multipath_lock
);
1283 fi
->fib_power
-= nexthop_nh
->nh_power
;
1284 nexthop_nh
->nh_power
= 0;
1285 spin_unlock_bh(&fib_multipath_lock
);
1289 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1290 if (event
== NETDEV_UNREGISTER
&&
1291 nexthop_nh
->nh_dev
== dev
) {
1296 } endfor_nexthops(fi
)
1297 if (dead
== fi
->fib_nhs
) {
1300 case NETDEV_UNREGISTER
:
1301 fi
->fib_flags
|= RTNH_F_DEAD
;
1304 fi
->fib_flags
|= RTNH_F_LINKDOWN
;
1314 /* Must be invoked inside of an RCU protected region. */
1315 void fib_select_default(const struct flowi4
*flp
, struct fib_result
*res
)
1317 struct fib_info
*fi
= NULL
, *last_resort
= NULL
;
1318 struct hlist_head
*fa_head
= res
->fa_head
;
1319 struct fib_table
*tb
= res
->table
;
1320 u8 slen
= 32 - res
->prefixlen
;
1321 int order
= -1, last_idx
= -1;
1322 struct fib_alias
*fa
, *fa1
= NULL
;
1323 u32 last_prio
= res
->fi
->fib_priority
;
1326 hlist_for_each_entry_rcu(fa
, fa_head
, fa_list
) {
1327 struct fib_info
*next_fi
= fa
->fa_info
;
1329 if (fa
->fa_slen
!= slen
)
1331 if (fa
->fa_tos
&& fa
->fa_tos
!= flp
->flowi4_tos
)
1333 if (fa
->tb_id
!= tb
->tb_id
)
1335 if (next_fi
->fib_priority
> last_prio
&&
1336 fa
->fa_tos
== last_tos
) {
1341 if (next_fi
->fib_flags
& RTNH_F_DEAD
)
1343 last_tos
= fa
->fa_tos
;
1344 last_prio
= next_fi
->fib_priority
;
1346 if (next_fi
->fib_scope
!= res
->scope
||
1347 fa
->fa_type
!= RTN_UNICAST
)
1349 if (!next_fi
->fib_nh
[0].nh_gw
||
1350 next_fi
->fib_nh
[0].nh_scope
!= RT_SCOPE_LINK
)
1353 fib_alias_accessed(fa
);
1356 if (next_fi
!= res
->fi
)
1359 } else if (!fib_detect_death(fi
, order
, &last_resort
,
1360 &last_idx
, fa1
->fa_default
)) {
1361 fib_result_assign(res
, fi
);
1362 fa1
->fa_default
= order
;
1369 if (order
<= 0 || !fi
) {
1371 fa1
->fa_default
= -1;
1375 if (!fib_detect_death(fi
, order
, &last_resort
, &last_idx
,
1377 fib_result_assign(res
, fi
);
1378 fa1
->fa_default
= order
;
1383 fib_result_assign(res
, last_resort
);
1384 fa1
->fa_default
= last_idx
;
1390 * Dead device goes up. We wake up dead nexthops.
1391 * It takes sense only on multipath routes.
1393 int fib_sync_up(struct net_device
*dev
, unsigned int nh_flags
)
1395 struct fib_info
*prev_fi
;
1397 struct hlist_head
*head
;
1401 if (!(dev
->flags
& IFF_UP
))
1405 hash
= fib_devindex_hashfn(dev
->ifindex
);
1406 head
= &fib_info_devhash
[hash
];
1409 hlist_for_each_entry(nh
, head
, nh_hash
) {
1410 struct fib_info
*fi
= nh
->nh_parent
;
1413 BUG_ON(!fi
->fib_nhs
);
1414 if (nh
->nh_dev
!= dev
|| fi
== prev_fi
)
1419 change_nexthops(fi
) {
1420 if (!(nexthop_nh
->nh_flags
& nh_flags
)) {
1424 if (!nexthop_nh
->nh_dev
||
1425 !(nexthop_nh
->nh_dev
->flags
& IFF_UP
))
1427 if (nexthop_nh
->nh_dev
!= dev
||
1428 !__in_dev_get_rtnl(dev
))
1431 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1432 spin_lock_bh(&fib_multipath_lock
);
1433 nexthop_nh
->nh_power
= 0;
1434 nexthop_nh
->nh_flags
&= ~nh_flags
;
1435 spin_unlock_bh(&fib_multipath_lock
);
1437 nexthop_nh
->nh_flags
&= ~nh_flags
;
1439 } endfor_nexthops(fi
)
1442 fi
->fib_flags
&= ~nh_flags
;
1450 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1453 * The algorithm is suboptimal, but it provides really
1454 * fair weighted route distribution.
1456 void fib_select_multipath(struct fib_result
*res
)
1458 struct fib_info
*fi
= res
->fi
;
1459 struct in_device
*in_dev
;
1462 spin_lock_bh(&fib_multipath_lock
);
1463 if (fi
->fib_power
<= 0) {
1465 change_nexthops(fi
) {
1466 in_dev
= __in_dev_get_rcu(nexthop_nh
->nh_dev
);
1467 if (nexthop_nh
->nh_flags
& RTNH_F_DEAD
)
1470 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev
) &&
1471 nexthop_nh
->nh_flags
& RTNH_F_LINKDOWN
)
1473 power
+= nexthop_nh
->nh_weight
;
1474 nexthop_nh
->nh_power
= nexthop_nh
->nh_weight
;
1475 } endfor_nexthops(fi
);
1476 fi
->fib_power
= power
;
1478 spin_unlock_bh(&fib_multipath_lock
);
1479 /* Race condition: route has just become dead. */
1486 /* w should be random number [0..fi->fib_power-1],
1487 * it is pretty bad approximation.
1490 w
= jiffies
% fi
->fib_power
;
1492 change_nexthops(fi
) {
1493 if (!(nexthop_nh
->nh_flags
& RTNH_F_DEAD
) &&
1494 nexthop_nh
->nh_power
) {
1495 w
-= nexthop_nh
->nh_power
;
1497 nexthop_nh
->nh_power
--;
1499 res
->nh_sel
= nhsel
;
1500 spin_unlock_bh(&fib_multipath_lock
);
1504 } endfor_nexthops(fi
);
1506 /* Race condition: route has just become dead. */
1508 spin_unlock_bh(&fib_multipath_lock
);