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 * ROUTE - implementation of the IP router.
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
65 #define pr_fmt(fmt) "IPv4: " fmt
67 #include <linux/module.h>
68 #include <linux/uaccess.h>
69 #include <linux/bitops.h>
70 #include <linux/types.h>
71 #include <linux/kernel.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/skbuff.h>
83 #include <linux/inetdevice.h>
84 #include <linux/igmp.h>
85 #include <linux/pkt_sched.h>
86 #include <linux/mroute.h>
87 #include <linux/netfilter_ipv4.h>
88 #include <linux/random.h>
89 #include <linux/rcupdate.h>
90 #include <linux/times.h>
91 #include <linux/slab.h>
92 #include <linux/jhash.h>
94 #include <net/dst_metadata.h>
95 #include <net/net_namespace.h>
96 #include <net/protocol.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/lwtunnel.h>
107 #include <net/netevent.h>
108 #include <net/rtnetlink.h>
110 #include <linux/sysctl.h>
111 #include <linux/kmemleak.h>
113 #include <net/secure_seq.h>
114 #include <net/ip_tunnels.h>
115 #include <net/l3mdev.h>
117 #include "fib_lookup.h"
119 #define RT_FL_TOS(oldflp4) \
120 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
122 #define RT_GC_TIMEOUT (300*HZ)
124 static int ip_rt_max_size
;
125 static int ip_rt_redirect_number __read_mostly
= 9;
126 static int ip_rt_redirect_load __read_mostly
= HZ
/ 50;
127 static int ip_rt_redirect_silence __read_mostly
= ((HZ
/ 50) << (9 + 1));
128 static int ip_rt_error_cost __read_mostly
= HZ
;
129 static int ip_rt_error_burst __read_mostly
= 5 * HZ
;
130 static int ip_rt_mtu_expires __read_mostly
= 10 * 60 * HZ
;
131 static u32 ip_rt_min_pmtu __read_mostly
= 512 + 20 + 20;
132 static int ip_rt_min_advmss __read_mostly
= 256;
134 static int ip_rt_gc_timeout __read_mostly
= RT_GC_TIMEOUT
;
136 static int ip_min_valid_pmtu __read_mostly
= IPV4_MIN_MTU
;
139 * Interface to generic destination cache.
142 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
);
143 static unsigned int ipv4_default_advmss(const struct dst_entry
*dst
);
144 static unsigned int ipv4_mtu(const struct dst_entry
*dst
);
145 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
);
146 static void ipv4_link_failure(struct sk_buff
*skb
);
147 static void ip_rt_update_pmtu(struct dst_entry
*dst
, struct sock
*sk
,
148 struct sk_buff
*skb
, u32 mtu
);
149 static void ip_do_redirect(struct dst_entry
*dst
, struct sock
*sk
,
150 struct sk_buff
*skb
);
151 static void ipv4_dst_destroy(struct dst_entry
*dst
);
153 static u32
*ipv4_cow_metrics(struct dst_entry
*dst
, unsigned long old
)
159 static struct neighbour
*ipv4_neigh_lookup(const struct dst_entry
*dst
,
162 static void ipv4_confirm_neigh(const struct dst_entry
*dst
, const void *daddr
);
164 static struct dst_ops ipv4_dst_ops
= {
166 .check
= ipv4_dst_check
,
167 .default_advmss
= ipv4_default_advmss
,
169 .cow_metrics
= ipv4_cow_metrics
,
170 .destroy
= ipv4_dst_destroy
,
171 .negative_advice
= ipv4_negative_advice
,
172 .link_failure
= ipv4_link_failure
,
173 .update_pmtu
= ip_rt_update_pmtu
,
174 .redirect
= ip_do_redirect
,
175 .local_out
= __ip_local_out
,
176 .neigh_lookup
= ipv4_neigh_lookup
,
177 .confirm_neigh
= ipv4_confirm_neigh
,
180 #define ECN_OR_COST(class) TC_PRIO_##class
182 const __u8 ip_tos2prio
[16] = {
184 ECN_OR_COST(BESTEFFORT
),
186 ECN_OR_COST(BESTEFFORT
),
192 ECN_OR_COST(INTERACTIVE
),
194 ECN_OR_COST(INTERACTIVE
),
195 TC_PRIO_INTERACTIVE_BULK
,
196 ECN_OR_COST(INTERACTIVE_BULK
),
197 TC_PRIO_INTERACTIVE_BULK
,
198 ECN_OR_COST(INTERACTIVE_BULK
)
200 EXPORT_SYMBOL(ip_tos2prio
);
202 static DEFINE_PER_CPU(struct rt_cache_stat
, rt_cache_stat
);
203 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
205 #ifdef CONFIG_PROC_FS
206 static void *rt_cache_seq_start(struct seq_file
*seq
, loff_t
*pos
)
210 return SEQ_START_TOKEN
;
213 static void *rt_cache_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
219 static void rt_cache_seq_stop(struct seq_file
*seq
, void *v
)
223 static int rt_cache_seq_show(struct seq_file
*seq
, void *v
)
225 if (v
== SEQ_START_TOKEN
)
226 seq_printf(seq
, "%-127s\n",
227 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
228 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
233 static const struct seq_operations rt_cache_seq_ops
= {
234 .start
= rt_cache_seq_start
,
235 .next
= rt_cache_seq_next
,
236 .stop
= rt_cache_seq_stop
,
237 .show
= rt_cache_seq_show
,
240 static int rt_cache_seq_open(struct inode
*inode
, struct file
*file
)
242 return seq_open(file
, &rt_cache_seq_ops
);
245 static const struct file_operations rt_cache_seq_fops
= {
246 .owner
= THIS_MODULE
,
247 .open
= rt_cache_seq_open
,
250 .release
= seq_release
,
254 static void *rt_cpu_seq_start(struct seq_file
*seq
, loff_t
*pos
)
259 return SEQ_START_TOKEN
;
261 for (cpu
= *pos
-1; cpu
< nr_cpu_ids
; ++cpu
) {
262 if (!cpu_possible(cpu
))
265 return &per_cpu(rt_cache_stat
, cpu
);
270 static void *rt_cpu_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
274 for (cpu
= *pos
; cpu
< nr_cpu_ids
; ++cpu
) {
275 if (!cpu_possible(cpu
))
278 return &per_cpu(rt_cache_stat
, cpu
);
284 static void rt_cpu_seq_stop(struct seq_file
*seq
, void *v
)
289 static int rt_cpu_seq_show(struct seq_file
*seq
, void *v
)
291 struct rt_cache_stat
*st
= v
;
293 if (v
== SEQ_START_TOKEN
) {
294 seq_printf(seq
, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
298 seq_printf(seq
,"%08x %08x %08x %08x %08x %08x %08x %08x "
299 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
300 dst_entries_get_slow(&ipv4_dst_ops
),
313 0, /* st->gc_total */
314 0, /* st->gc_ignored */
315 0, /* st->gc_goal_miss */
316 0, /* st->gc_dst_overflow */
317 0, /* st->in_hlist_search */
318 0 /* st->out_hlist_search */
323 static const struct seq_operations rt_cpu_seq_ops
= {
324 .start
= rt_cpu_seq_start
,
325 .next
= rt_cpu_seq_next
,
326 .stop
= rt_cpu_seq_stop
,
327 .show
= rt_cpu_seq_show
,
331 static int rt_cpu_seq_open(struct inode
*inode
, struct file
*file
)
333 return seq_open(file
, &rt_cpu_seq_ops
);
336 static const struct file_operations rt_cpu_seq_fops
= {
337 .owner
= THIS_MODULE
,
338 .open
= rt_cpu_seq_open
,
341 .release
= seq_release
,
344 #ifdef CONFIG_IP_ROUTE_CLASSID
345 static int rt_acct_proc_show(struct seq_file
*m
, void *v
)
347 struct ip_rt_acct
*dst
, *src
;
350 dst
= kcalloc(256, sizeof(struct ip_rt_acct
), GFP_KERNEL
);
354 for_each_possible_cpu(i
) {
355 src
= (struct ip_rt_acct
*)per_cpu_ptr(ip_rt_acct
, i
);
356 for (j
= 0; j
< 256; j
++) {
357 dst
[j
].o_bytes
+= src
[j
].o_bytes
;
358 dst
[j
].o_packets
+= src
[j
].o_packets
;
359 dst
[j
].i_bytes
+= src
[j
].i_bytes
;
360 dst
[j
].i_packets
+= src
[j
].i_packets
;
364 seq_write(m
, dst
, 256 * sizeof(struct ip_rt_acct
));
369 static int rt_acct_proc_open(struct inode
*inode
, struct file
*file
)
371 return single_open(file
, rt_acct_proc_show
, NULL
);
374 static const struct file_operations rt_acct_proc_fops
= {
375 .owner
= THIS_MODULE
,
376 .open
= rt_acct_proc_open
,
379 .release
= single_release
,
383 static int __net_init
ip_rt_do_proc_init(struct net
*net
)
385 struct proc_dir_entry
*pde
;
387 pde
= proc_create("rt_cache", S_IRUGO
, net
->proc_net
,
392 pde
= proc_create("rt_cache", S_IRUGO
,
393 net
->proc_net_stat
, &rt_cpu_seq_fops
);
397 #ifdef CONFIG_IP_ROUTE_CLASSID
398 pde
= proc_create("rt_acct", 0, net
->proc_net
, &rt_acct_proc_fops
);
404 #ifdef CONFIG_IP_ROUTE_CLASSID
406 remove_proc_entry("rt_cache", net
->proc_net_stat
);
409 remove_proc_entry("rt_cache", net
->proc_net
);
414 static void __net_exit
ip_rt_do_proc_exit(struct net
*net
)
416 remove_proc_entry("rt_cache", net
->proc_net_stat
);
417 remove_proc_entry("rt_cache", net
->proc_net
);
418 #ifdef CONFIG_IP_ROUTE_CLASSID
419 remove_proc_entry("rt_acct", net
->proc_net
);
423 static struct pernet_operations ip_rt_proc_ops __net_initdata
= {
424 .init
= ip_rt_do_proc_init
,
425 .exit
= ip_rt_do_proc_exit
,
428 static int __init
ip_rt_proc_init(void)
430 return register_pernet_subsys(&ip_rt_proc_ops
);
434 static inline int ip_rt_proc_init(void)
438 #endif /* CONFIG_PROC_FS */
440 static inline bool rt_is_expired(const struct rtable
*rth
)
442 return rth
->rt_genid
!= rt_genid_ipv4(dev_net(rth
->dst
.dev
));
445 void rt_cache_flush(struct net
*net
)
447 rt_genid_bump_ipv4(net
);
450 static struct neighbour
*ipv4_neigh_lookup(const struct dst_entry
*dst
,
454 struct net_device
*dev
= dst
->dev
;
455 const __be32
*pkey
= daddr
;
456 const struct rtable
*rt
;
459 rt
= (const struct rtable
*) dst
;
461 pkey
= (const __be32
*) &rt
->rt_gateway
;
463 pkey
= &ip_hdr(skb
)->daddr
;
465 n
= __ipv4_neigh_lookup(dev
, *(__force u32
*)pkey
);
468 return neigh_create(&arp_tbl
, pkey
, dev
);
471 static void ipv4_confirm_neigh(const struct dst_entry
*dst
, const void *daddr
)
473 struct net_device
*dev
= dst
->dev
;
474 const __be32
*pkey
= daddr
;
475 const struct rtable
*rt
;
477 rt
= (const struct rtable
*)dst
;
479 pkey
= (const __be32
*)&rt
->rt_gateway
;
482 (RTCF_MULTICAST
| RTCF_BROADCAST
| RTCF_LOCAL
)))
485 __ipv4_confirm_neigh(dev
, *(__force u32
*)pkey
);
488 #define IP_IDENTS_SZ 2048u
490 static atomic_t
*ip_idents __read_mostly
;
491 static u32
*ip_tstamps __read_mostly
;
493 /* In order to protect privacy, we add a perturbation to identifiers
494 * if one generator is seldom used. This makes hard for an attacker
495 * to infer how many packets were sent between two points in time.
497 u32
ip_idents_reserve(u32 hash
, int segs
)
499 u32
*p_tstamp
= ip_tstamps
+ hash
% IP_IDENTS_SZ
;
500 atomic_t
*p_id
= ip_idents
+ hash
% IP_IDENTS_SZ
;
501 u32 old
= READ_ONCE(*p_tstamp
);
502 u32 now
= (u32
)jiffies
;
505 if (old
!= now
&& cmpxchg(p_tstamp
, old
, now
) == old
)
506 delta
= prandom_u32_max(now
- old
);
508 /* Do not use atomic_add_return() as it makes UBSAN unhappy */
510 old
= (u32
)atomic_read(p_id
);
511 new = old
+ delta
+ segs
;
512 } while (atomic_cmpxchg(p_id
, old
, new) != old
);
516 EXPORT_SYMBOL(ip_idents_reserve
);
518 void __ip_select_ident(struct net
*net
, struct iphdr
*iph
, int segs
)
520 static u32 ip_idents_hashrnd __read_mostly
;
523 net_get_random_once(&ip_idents_hashrnd
, sizeof(ip_idents_hashrnd
));
525 hash
= jhash_3words((__force u32
)iph
->daddr
,
526 (__force u32
)iph
->saddr
,
527 iph
->protocol
^ net_hash_mix(net
),
529 id
= ip_idents_reserve(hash
, segs
);
532 EXPORT_SYMBOL(__ip_select_ident
);
534 static void __build_flow_key(const struct net
*net
, struct flowi4
*fl4
,
535 const struct sock
*sk
,
536 const struct iphdr
*iph
,
538 u8 prot
, u32 mark
, int flow_flags
)
541 const struct inet_sock
*inet
= inet_sk(sk
);
543 oif
= sk
->sk_bound_dev_if
;
545 tos
= RT_CONN_FLAGS(sk
);
546 prot
= inet
->hdrincl
? IPPROTO_RAW
: sk
->sk_protocol
;
548 flowi4_init_output(fl4
, oif
, mark
, tos
,
549 RT_SCOPE_UNIVERSE
, prot
,
551 iph
->daddr
, iph
->saddr
, 0, 0,
552 sock_net_uid(net
, sk
));
555 static void build_skb_flow_key(struct flowi4
*fl4
, const struct sk_buff
*skb
,
556 const struct sock
*sk
)
558 const struct net
*net
= dev_net(skb
->dev
);
559 const struct iphdr
*iph
= ip_hdr(skb
);
560 int oif
= skb
->dev
->ifindex
;
561 u8 tos
= RT_TOS(iph
->tos
);
562 u8 prot
= iph
->protocol
;
563 u32 mark
= skb
->mark
;
565 __build_flow_key(net
, fl4
, sk
, iph
, oif
, tos
, prot
, mark
, 0);
568 static void build_sk_flow_key(struct flowi4
*fl4
, const struct sock
*sk
)
570 const struct inet_sock
*inet
= inet_sk(sk
);
571 const struct ip_options_rcu
*inet_opt
;
572 __be32 daddr
= inet
->inet_daddr
;
575 inet_opt
= rcu_dereference(inet
->inet_opt
);
576 if (inet_opt
&& inet_opt
->opt
.srr
)
577 daddr
= inet_opt
->opt
.faddr
;
578 flowi4_init_output(fl4
, sk
->sk_bound_dev_if
, sk
->sk_mark
,
579 RT_CONN_FLAGS(sk
), RT_SCOPE_UNIVERSE
,
580 inet
->hdrincl
? IPPROTO_RAW
: sk
->sk_protocol
,
581 inet_sk_flowi_flags(sk
),
582 daddr
, inet
->inet_saddr
, 0, 0, sk
->sk_uid
);
586 static void ip_rt_build_flow_key(struct flowi4
*fl4
, const struct sock
*sk
,
587 const struct sk_buff
*skb
)
590 build_skb_flow_key(fl4
, skb
, sk
);
592 build_sk_flow_key(fl4
, sk
);
595 static DEFINE_SPINLOCK(fnhe_lock
);
597 static void fnhe_flush_routes(struct fib_nh_exception
*fnhe
)
601 rt
= rcu_dereference(fnhe
->fnhe_rth_input
);
603 RCU_INIT_POINTER(fnhe
->fnhe_rth_input
, NULL
);
604 dst_dev_put(&rt
->dst
);
605 dst_release(&rt
->dst
);
607 rt
= rcu_dereference(fnhe
->fnhe_rth_output
);
609 RCU_INIT_POINTER(fnhe
->fnhe_rth_output
, NULL
);
610 dst_dev_put(&rt
->dst
);
611 dst_release(&rt
->dst
);
615 static struct fib_nh_exception
*fnhe_oldest(struct fnhe_hash_bucket
*hash
)
617 struct fib_nh_exception
*fnhe
, *oldest
;
619 oldest
= rcu_dereference(hash
->chain
);
620 for (fnhe
= rcu_dereference(oldest
->fnhe_next
); fnhe
;
621 fnhe
= rcu_dereference(fnhe
->fnhe_next
)) {
622 if (time_before(fnhe
->fnhe_stamp
, oldest
->fnhe_stamp
))
625 fnhe_flush_routes(oldest
);
629 static inline u32
fnhe_hashfun(__be32 daddr
)
631 static u32 fnhe_hashrnd __read_mostly
;
634 net_get_random_once(&fnhe_hashrnd
, sizeof(fnhe_hashrnd
));
635 hval
= jhash_1word((__force u32
) daddr
, fnhe_hashrnd
);
636 return hash_32(hval
, FNHE_HASH_SHIFT
);
639 static void fill_route_from_fnhe(struct rtable
*rt
, struct fib_nh_exception
*fnhe
)
641 rt
->rt_pmtu
= fnhe
->fnhe_pmtu
;
642 rt
->rt_mtu_locked
= fnhe
->fnhe_mtu_locked
;
643 rt
->dst
.expires
= fnhe
->fnhe_expires
;
646 rt
->rt_flags
|= RTCF_REDIRECTED
;
647 rt
->rt_gateway
= fnhe
->fnhe_gw
;
648 rt
->rt_uses_gateway
= 1;
652 static void update_or_create_fnhe(struct fib_nh
*nh
, __be32 daddr
, __be32 gw
,
653 u32 pmtu
, bool lock
, unsigned long expires
)
655 struct fnhe_hash_bucket
*hash
;
656 struct fib_nh_exception
*fnhe
;
662 genid
= fnhe_genid(dev_net(nh
->nh_dev
));
663 hval
= fnhe_hashfun(daddr
);
665 spin_lock_bh(&fnhe_lock
);
667 hash
= rcu_dereference(nh
->nh_exceptions
);
669 hash
= kzalloc(FNHE_HASH_SIZE
* sizeof(*hash
), GFP_ATOMIC
);
672 rcu_assign_pointer(nh
->nh_exceptions
, hash
);
678 for (fnhe
= rcu_dereference(hash
->chain
); fnhe
;
679 fnhe
= rcu_dereference(fnhe
->fnhe_next
)) {
680 if (fnhe
->fnhe_daddr
== daddr
)
686 if (fnhe
->fnhe_genid
!= genid
)
687 fnhe
->fnhe_genid
= genid
;
691 fnhe
->fnhe_pmtu
= pmtu
;
692 fnhe
->fnhe_mtu_locked
= lock
;
694 fnhe
->fnhe_expires
= max(1UL, expires
);
695 /* Update all cached dsts too */
696 rt
= rcu_dereference(fnhe
->fnhe_rth_input
);
698 fill_route_from_fnhe(rt
, fnhe
);
699 rt
= rcu_dereference(fnhe
->fnhe_rth_output
);
701 fill_route_from_fnhe(rt
, fnhe
);
703 if (depth
> FNHE_RECLAIM_DEPTH
)
704 fnhe
= fnhe_oldest(hash
);
706 fnhe
= kzalloc(sizeof(*fnhe
), GFP_ATOMIC
);
710 fnhe
->fnhe_next
= hash
->chain
;
711 rcu_assign_pointer(hash
->chain
, fnhe
);
713 fnhe
->fnhe_genid
= genid
;
714 fnhe
->fnhe_daddr
= daddr
;
716 fnhe
->fnhe_pmtu
= pmtu
;
717 fnhe
->fnhe_mtu_locked
= lock
;
718 fnhe
->fnhe_expires
= max(1UL, expires
);
720 /* Exception created; mark the cached routes for the nexthop
721 * stale, so anyone caching it rechecks if this exception
724 rt
= rcu_dereference(nh
->nh_rth_input
);
726 rt
->dst
.obsolete
= DST_OBSOLETE_KILL
;
728 for_each_possible_cpu(i
) {
729 struct rtable __rcu
**prt
;
730 prt
= per_cpu_ptr(nh
->nh_pcpu_rth_output
, i
);
731 rt
= rcu_dereference(*prt
);
733 rt
->dst
.obsolete
= DST_OBSOLETE_KILL
;
737 fnhe
->fnhe_stamp
= jiffies
;
740 spin_unlock_bh(&fnhe_lock
);
743 static void __ip_do_redirect(struct rtable
*rt
, struct sk_buff
*skb
, struct flowi4
*fl4
,
746 __be32 new_gw
= icmp_hdr(skb
)->un
.gateway
;
747 __be32 old_gw
= ip_hdr(skb
)->saddr
;
748 struct net_device
*dev
= skb
->dev
;
749 struct in_device
*in_dev
;
750 struct fib_result res
;
754 switch (icmp_hdr(skb
)->code
& 7) {
756 case ICMP_REDIR_NETTOS
:
757 case ICMP_REDIR_HOST
:
758 case ICMP_REDIR_HOSTTOS
:
765 if (rt
->rt_gateway
!= old_gw
)
768 in_dev
= __in_dev_get_rcu(dev
);
773 if (new_gw
== old_gw
|| !IN_DEV_RX_REDIRECTS(in_dev
) ||
774 ipv4_is_multicast(new_gw
) || ipv4_is_lbcast(new_gw
) ||
775 ipv4_is_zeronet(new_gw
))
776 goto reject_redirect
;
778 if (!IN_DEV_SHARED_MEDIA(in_dev
)) {
779 if (!inet_addr_onlink(in_dev
, new_gw
, old_gw
))
780 goto reject_redirect
;
781 if (IN_DEV_SEC_REDIRECTS(in_dev
) && ip_fib_check_default(new_gw
, dev
))
782 goto reject_redirect
;
784 if (inet_addr_type(net
, new_gw
) != RTN_UNICAST
)
785 goto reject_redirect
;
788 n
= __ipv4_neigh_lookup(rt
->dst
.dev
, new_gw
);
790 n
= neigh_create(&arp_tbl
, &new_gw
, rt
->dst
.dev
);
792 if (!(n
->nud_state
& NUD_VALID
)) {
793 neigh_event_send(n
, NULL
);
795 if (fib_lookup(net
, fl4
, &res
, 0) == 0) {
796 struct fib_nh
*nh
= &FIB_RES_NH(res
);
798 update_or_create_fnhe(nh
, fl4
->daddr
, new_gw
,
800 jiffies
+ ip_rt_gc_timeout
);
803 rt
->dst
.obsolete
= DST_OBSOLETE_KILL
;
804 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE
, n
);
811 #ifdef CONFIG_IP_ROUTE_VERBOSE
812 if (IN_DEV_LOG_MARTIANS(in_dev
)) {
813 const struct iphdr
*iph
= (const struct iphdr
*) skb
->data
;
814 __be32 daddr
= iph
->daddr
;
815 __be32 saddr
= iph
->saddr
;
817 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
818 " Advised path = %pI4 -> %pI4\n",
819 &old_gw
, dev
->name
, &new_gw
,
826 static void ip_do_redirect(struct dst_entry
*dst
, struct sock
*sk
, struct sk_buff
*skb
)
830 const struct iphdr
*iph
= (const struct iphdr
*) skb
->data
;
831 struct net
*net
= dev_net(skb
->dev
);
832 int oif
= skb
->dev
->ifindex
;
833 u8 tos
= RT_TOS(iph
->tos
);
834 u8 prot
= iph
->protocol
;
835 u32 mark
= skb
->mark
;
837 rt
= (struct rtable
*) dst
;
839 __build_flow_key(net
, &fl4
, sk
, iph
, oif
, tos
, prot
, mark
, 0);
840 __ip_do_redirect(rt
, skb
, &fl4
, true);
843 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
)
845 struct rtable
*rt
= (struct rtable
*)dst
;
846 struct dst_entry
*ret
= dst
;
849 if (dst
->obsolete
> 0) {
852 } else if ((rt
->rt_flags
& RTCF_REDIRECTED
) ||
863 * 1. The first ip_rt_redirect_number redirects are sent
864 * with exponential backoff, then we stop sending them at all,
865 * assuming that the host ignores our redirects.
866 * 2. If we did not see packets requiring redirects
867 * during ip_rt_redirect_silence, we assume that the host
868 * forgot redirected route and start to send redirects again.
870 * This algorithm is much cheaper and more intelligent than dumb load limiting
873 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
874 * and "frag. need" (breaks PMTU discovery) in icmp.c.
877 void ip_rt_send_redirect(struct sk_buff
*skb
)
879 struct rtable
*rt
= skb_rtable(skb
);
880 struct in_device
*in_dev
;
881 struct inet_peer
*peer
;
887 in_dev
= __in_dev_get_rcu(rt
->dst
.dev
);
888 if (!in_dev
|| !IN_DEV_TX_REDIRECTS(in_dev
)) {
892 log_martians
= IN_DEV_LOG_MARTIANS(in_dev
);
893 vif
= l3mdev_master_ifindex_rcu(rt
->dst
.dev
);
896 net
= dev_net(rt
->dst
.dev
);
897 peer
= inet_getpeer_v4(net
->ipv4
.peers
, ip_hdr(skb
)->saddr
, vif
, 1);
899 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
,
900 rt_nexthop(rt
, ip_hdr(skb
)->daddr
));
904 /* No redirected packets during ip_rt_redirect_silence;
905 * reset the algorithm.
907 if (time_after(jiffies
, peer
->rate_last
+ ip_rt_redirect_silence
))
908 peer
->rate_tokens
= 0;
910 /* Too many ignored redirects; do not send anything
911 * set dst.rate_last to the last seen redirected packet.
913 if (peer
->rate_tokens
>= ip_rt_redirect_number
) {
914 peer
->rate_last
= jiffies
;
918 /* Check for load limit; set rate_last to the latest sent
921 if (peer
->rate_tokens
== 0 ||
924 (ip_rt_redirect_load
<< peer
->rate_tokens
)))) {
925 __be32 gw
= rt_nexthop(rt
, ip_hdr(skb
)->daddr
);
927 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, gw
);
928 peer
->rate_last
= jiffies
;
930 #ifdef CONFIG_IP_ROUTE_VERBOSE
932 peer
->rate_tokens
== ip_rt_redirect_number
)
933 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
934 &ip_hdr(skb
)->saddr
, inet_iif(skb
),
935 &ip_hdr(skb
)->daddr
, &gw
);
942 static int ip_error(struct sk_buff
*skb
)
944 struct in_device
*in_dev
= __in_dev_get_rcu(skb
->dev
);
945 struct rtable
*rt
= skb_rtable(skb
);
946 struct inet_peer
*peer
;
952 /* IP on this device is disabled. */
956 net
= dev_net(rt
->dst
.dev
);
957 if (!IN_DEV_FORWARD(in_dev
)) {
958 switch (rt
->dst
.error
) {
960 __IP_INC_STATS(net
, IPSTATS_MIB_INADDRERRORS
);
964 __IP_INC_STATS(net
, IPSTATS_MIB_INNOROUTES
);
970 switch (rt
->dst
.error
) {
975 code
= ICMP_HOST_UNREACH
;
978 code
= ICMP_NET_UNREACH
;
979 __IP_INC_STATS(net
, IPSTATS_MIB_INNOROUTES
);
982 code
= ICMP_PKT_FILTERED
;
986 peer
= inet_getpeer_v4(net
->ipv4
.peers
, ip_hdr(skb
)->saddr
,
987 l3mdev_master_ifindex(skb
->dev
), 1);
992 peer
->rate_tokens
+= now
- peer
->rate_last
;
993 if (peer
->rate_tokens
> ip_rt_error_burst
)
994 peer
->rate_tokens
= ip_rt_error_burst
;
995 peer
->rate_last
= now
;
996 if (peer
->rate_tokens
>= ip_rt_error_cost
)
997 peer
->rate_tokens
-= ip_rt_error_cost
;
1003 icmp_send(skb
, ICMP_DEST_UNREACH
, code
, 0);
1005 out
: kfree_skb(skb
);
1009 static void __ip_rt_update_pmtu(struct rtable
*rt
, struct flowi4
*fl4
, u32 mtu
)
1011 struct dst_entry
*dst
= &rt
->dst
;
1012 struct fib_result res
;
1015 if (ip_mtu_locked(dst
))
1018 if (ipv4_mtu(dst
) < mtu
)
1021 if (mtu
< ip_rt_min_pmtu
) {
1023 mtu
= ip_rt_min_pmtu
;
1026 if (rt
->rt_pmtu
== mtu
&&
1027 time_before(jiffies
, dst
->expires
- ip_rt_mtu_expires
/ 2))
1031 if (fib_lookup(dev_net(dst
->dev
), fl4
, &res
, 0) == 0) {
1032 struct fib_nh
*nh
= &FIB_RES_NH(res
);
1034 update_or_create_fnhe(nh
, fl4
->daddr
, 0, mtu
, lock
,
1035 jiffies
+ ip_rt_mtu_expires
);
1040 static void ip_rt_update_pmtu(struct dst_entry
*dst
, struct sock
*sk
,
1041 struct sk_buff
*skb
, u32 mtu
)
1043 struct rtable
*rt
= (struct rtable
*) dst
;
1046 ip_rt_build_flow_key(&fl4
, sk
, skb
);
1047 __ip_rt_update_pmtu(rt
, &fl4
, mtu
);
1050 void ipv4_update_pmtu(struct sk_buff
*skb
, struct net
*net
, u32 mtu
,
1051 int oif
, u32 mark
, u8 protocol
, int flow_flags
)
1053 const struct iphdr
*iph
= (const struct iphdr
*) skb
->data
;
1058 mark
= IP4_REPLY_MARK(net
, skb
->mark
);
1060 __build_flow_key(net
, &fl4
, NULL
, iph
, oif
,
1061 RT_TOS(iph
->tos
), protocol
, mark
, flow_flags
);
1062 rt
= __ip_route_output_key(net
, &fl4
);
1064 __ip_rt_update_pmtu(rt
, &fl4
, mtu
);
1068 EXPORT_SYMBOL_GPL(ipv4_update_pmtu
);
1070 static void __ipv4_sk_update_pmtu(struct sk_buff
*skb
, struct sock
*sk
, u32 mtu
)
1072 const struct iphdr
*iph
= (const struct iphdr
*) skb
->data
;
1076 __build_flow_key(sock_net(sk
), &fl4
, sk
, iph
, 0, 0, 0, 0, 0);
1078 if (!fl4
.flowi4_mark
)
1079 fl4
.flowi4_mark
= IP4_REPLY_MARK(sock_net(sk
), skb
->mark
);
1081 rt
= __ip_route_output_key(sock_net(sk
), &fl4
);
1083 __ip_rt_update_pmtu(rt
, &fl4
, mtu
);
1088 void ipv4_sk_update_pmtu(struct sk_buff
*skb
, struct sock
*sk
, u32 mtu
)
1090 const struct iphdr
*iph
= (const struct iphdr
*) skb
->data
;
1093 struct dst_entry
*odst
= NULL
;
1095 struct net
*net
= sock_net(sk
);
1099 if (!ip_sk_accept_pmtu(sk
))
1102 odst
= sk_dst_get(sk
);
1104 if (sock_owned_by_user(sk
) || !odst
) {
1105 __ipv4_sk_update_pmtu(skb
, sk
, mtu
);
1109 __build_flow_key(net
, &fl4
, sk
, iph
, 0, 0, 0, 0, 0);
1111 rt
= (struct rtable
*)odst
;
1112 if (odst
->obsolete
&& !odst
->ops
->check(odst
, 0)) {
1113 rt
= ip_route_output_flow(sock_net(sk
), &fl4
, sk
);
1120 __ip_rt_update_pmtu((struct rtable
*) rt
->dst
.path
, &fl4
, mtu
);
1122 if (!dst_check(&rt
->dst
, 0)) {
1124 dst_release(&rt
->dst
);
1126 rt
= ip_route_output_flow(sock_net(sk
), &fl4
, sk
);
1134 sk_dst_set(sk
, &rt
->dst
);
1140 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu
);
1142 void ipv4_redirect(struct sk_buff
*skb
, struct net
*net
,
1143 int oif
, u32 mark
, u8 protocol
, int flow_flags
)
1145 const struct iphdr
*iph
= (const struct iphdr
*) skb
->data
;
1149 __build_flow_key(net
, &fl4
, NULL
, iph
, oif
,
1150 RT_TOS(iph
->tos
), protocol
, mark
, flow_flags
);
1151 rt
= __ip_route_output_key(net
, &fl4
);
1153 __ip_do_redirect(rt
, skb
, &fl4
, false);
1157 EXPORT_SYMBOL_GPL(ipv4_redirect
);
1159 void ipv4_sk_redirect(struct sk_buff
*skb
, struct sock
*sk
)
1161 const struct iphdr
*iph
= (const struct iphdr
*) skb
->data
;
1164 struct net
*net
= sock_net(sk
);
1166 __build_flow_key(net
, &fl4
, sk
, iph
, 0, 0, 0, 0, 0);
1167 rt
= __ip_route_output_key(net
, &fl4
);
1169 __ip_do_redirect(rt
, skb
, &fl4
, false);
1173 EXPORT_SYMBOL_GPL(ipv4_sk_redirect
);
1175 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
)
1177 struct rtable
*rt
= (struct rtable
*) dst
;
1179 /* All IPV4 dsts are created with ->obsolete set to the value
1180 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1181 * into this function always.
1183 * When a PMTU/redirect information update invalidates a route,
1184 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1185 * DST_OBSOLETE_DEAD by dst_free().
1187 if (dst
->obsolete
!= DST_OBSOLETE_FORCE_CHK
|| rt_is_expired(rt
))
1192 static void ipv4_link_failure(struct sk_buff
*skb
)
1196 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_HOST_UNREACH
, 0);
1198 rt
= skb_rtable(skb
);
1200 dst_set_expires(&rt
->dst
, 0);
1203 static int ip_rt_bug(struct net
*net
, struct sock
*sk
, struct sk_buff
*skb
)
1205 pr_debug("%s: %pI4 -> %pI4, %s\n",
1206 __func__
, &ip_hdr(skb
)->saddr
, &ip_hdr(skb
)->daddr
,
1207 skb
->dev
? skb
->dev
->name
: "?");
1214 We do not cache source address of outgoing interface,
1215 because it is used only by IP RR, TS and SRR options,
1216 so that it out of fast path.
1218 BTW remember: "addr" is allowed to be not aligned
1222 void ip_rt_get_source(u8
*addr
, struct sk_buff
*skb
, struct rtable
*rt
)
1226 if (rt_is_output_route(rt
))
1227 src
= ip_hdr(skb
)->saddr
;
1229 struct fib_result res
;
1235 memset(&fl4
, 0, sizeof(fl4
));
1236 fl4
.daddr
= iph
->daddr
;
1237 fl4
.saddr
= iph
->saddr
;
1238 fl4
.flowi4_tos
= RT_TOS(iph
->tos
);
1239 fl4
.flowi4_oif
= rt
->dst
.dev
->ifindex
;
1240 fl4
.flowi4_iif
= skb
->dev
->ifindex
;
1241 fl4
.flowi4_mark
= skb
->mark
;
1244 if (fib_lookup(dev_net(rt
->dst
.dev
), &fl4
, &res
, 0) == 0)
1245 src
= FIB_RES_PREFSRC(dev_net(rt
->dst
.dev
), res
);
1247 src
= inet_select_addr(rt
->dst
.dev
,
1248 rt_nexthop(rt
, iph
->daddr
),
1252 memcpy(addr
, &src
, 4);
1255 #ifdef CONFIG_IP_ROUTE_CLASSID
1256 static void set_class_tag(struct rtable
*rt
, u32 tag
)
1258 if (!(rt
->dst
.tclassid
& 0xFFFF))
1259 rt
->dst
.tclassid
|= tag
& 0xFFFF;
1260 if (!(rt
->dst
.tclassid
& 0xFFFF0000))
1261 rt
->dst
.tclassid
|= tag
& 0xFFFF0000;
1265 static unsigned int ipv4_default_advmss(const struct dst_entry
*dst
)
1267 unsigned int header_size
= sizeof(struct tcphdr
) + sizeof(struct iphdr
);
1268 unsigned int advmss
= max_t(unsigned int, ipv4_mtu(dst
) - header_size
,
1271 return min(advmss
, IPV4_MAX_PMTU
- header_size
);
1274 static unsigned int ipv4_mtu(const struct dst_entry
*dst
)
1276 const struct rtable
*rt
= (const struct rtable
*) dst
;
1277 unsigned int mtu
= rt
->rt_pmtu
;
1279 if (!mtu
|| time_after_eq(jiffies
, rt
->dst
.expires
))
1280 mtu
= dst_metric_raw(dst
, RTAX_MTU
);
1285 mtu
= READ_ONCE(dst
->dev
->mtu
);
1287 if (unlikely(ip_mtu_locked(dst
))) {
1288 if (rt
->rt_uses_gateway
&& mtu
> 576)
1292 mtu
= min_t(unsigned int, mtu
, IP_MAX_MTU
);
1294 return mtu
- lwtunnel_headroom(dst
->lwtstate
, mtu
);
1297 static void ip_del_fnhe(struct fib_nh
*nh
, __be32 daddr
)
1299 struct fnhe_hash_bucket
*hash
;
1300 struct fib_nh_exception
*fnhe
, __rcu
**fnhe_p
;
1301 u32 hval
= fnhe_hashfun(daddr
);
1303 spin_lock_bh(&fnhe_lock
);
1305 hash
= rcu_dereference_protected(nh
->nh_exceptions
,
1306 lockdep_is_held(&fnhe_lock
));
1309 fnhe_p
= &hash
->chain
;
1310 fnhe
= rcu_dereference_protected(*fnhe_p
, lockdep_is_held(&fnhe_lock
));
1312 if (fnhe
->fnhe_daddr
== daddr
) {
1313 rcu_assign_pointer(*fnhe_p
, rcu_dereference_protected(
1314 fnhe
->fnhe_next
, lockdep_is_held(&fnhe_lock
)));
1315 fnhe_flush_routes(fnhe
);
1316 kfree_rcu(fnhe
, rcu
);
1319 fnhe_p
= &fnhe
->fnhe_next
;
1320 fnhe
= rcu_dereference_protected(fnhe
->fnhe_next
,
1321 lockdep_is_held(&fnhe_lock
));
1324 spin_unlock_bh(&fnhe_lock
);
1327 static struct fib_nh_exception
*find_exception(struct fib_nh
*nh
, __be32 daddr
)
1329 struct fnhe_hash_bucket
*hash
= rcu_dereference(nh
->nh_exceptions
);
1330 struct fib_nh_exception
*fnhe
;
1336 hval
= fnhe_hashfun(daddr
);
1338 for (fnhe
= rcu_dereference(hash
[hval
].chain
); fnhe
;
1339 fnhe
= rcu_dereference(fnhe
->fnhe_next
)) {
1340 if (fnhe
->fnhe_daddr
== daddr
) {
1341 if (fnhe
->fnhe_expires
&&
1342 time_after(jiffies
, fnhe
->fnhe_expires
)) {
1343 ip_del_fnhe(nh
, daddr
);
1352 static bool rt_bind_exception(struct rtable
*rt
, struct fib_nh_exception
*fnhe
,
1353 __be32 daddr
, const bool do_cache
)
1357 spin_lock_bh(&fnhe_lock
);
1359 if (daddr
== fnhe
->fnhe_daddr
) {
1360 struct rtable __rcu
**porig
;
1361 struct rtable
*orig
;
1362 int genid
= fnhe_genid(dev_net(rt
->dst
.dev
));
1364 if (rt_is_input_route(rt
))
1365 porig
= &fnhe
->fnhe_rth_input
;
1367 porig
= &fnhe
->fnhe_rth_output
;
1368 orig
= rcu_dereference(*porig
);
1370 if (fnhe
->fnhe_genid
!= genid
) {
1371 fnhe
->fnhe_genid
= genid
;
1373 fnhe
->fnhe_pmtu
= 0;
1374 fnhe
->fnhe_expires
= 0;
1375 fnhe_flush_routes(fnhe
);
1378 fill_route_from_fnhe(rt
, fnhe
);
1379 if (!rt
->rt_gateway
)
1380 rt
->rt_gateway
= daddr
;
1384 rcu_assign_pointer(*porig
, rt
);
1386 dst_dev_put(&orig
->dst
);
1387 dst_release(&orig
->dst
);
1392 fnhe
->fnhe_stamp
= jiffies
;
1394 spin_unlock_bh(&fnhe_lock
);
1399 static bool rt_cache_route(struct fib_nh
*nh
, struct rtable
*rt
)
1401 struct rtable
*orig
, *prev
, **p
;
1404 if (rt_is_input_route(rt
)) {
1405 p
= (struct rtable
**)&nh
->nh_rth_input
;
1407 p
= (struct rtable
**)raw_cpu_ptr(nh
->nh_pcpu_rth_output
);
1411 /* hold dst before doing cmpxchg() to avoid race condition
1415 prev
= cmpxchg(p
, orig
, rt
);
1418 dst_dev_put(&orig
->dst
);
1419 dst_release(&orig
->dst
);
1422 dst_release(&rt
->dst
);
1429 struct uncached_list
{
1431 struct list_head head
;
1434 static DEFINE_PER_CPU_ALIGNED(struct uncached_list
, rt_uncached_list
);
1436 void rt_add_uncached_list(struct rtable
*rt
)
1438 struct uncached_list
*ul
= raw_cpu_ptr(&rt_uncached_list
);
1440 rt
->rt_uncached_list
= ul
;
1442 spin_lock_bh(&ul
->lock
);
1443 list_add_tail(&rt
->rt_uncached
, &ul
->head
);
1444 spin_unlock_bh(&ul
->lock
);
1447 void rt_del_uncached_list(struct rtable
*rt
)
1449 if (!list_empty(&rt
->rt_uncached
)) {
1450 struct uncached_list
*ul
= rt
->rt_uncached_list
;
1452 spin_lock_bh(&ul
->lock
);
1453 list_del(&rt
->rt_uncached
);
1454 spin_unlock_bh(&ul
->lock
);
1458 static void ipv4_dst_destroy(struct dst_entry
*dst
)
1460 struct dst_metrics
*p
= (struct dst_metrics
*)DST_METRICS_PTR(dst
);
1461 struct rtable
*rt
= (struct rtable
*)dst
;
1463 if (p
!= &dst_default_metrics
&& refcount_dec_and_test(&p
->refcnt
))
1466 rt_del_uncached_list(rt
);
1469 void rt_flush_dev(struct net_device
*dev
)
1471 struct net
*net
= dev_net(dev
);
1475 for_each_possible_cpu(cpu
) {
1476 struct uncached_list
*ul
= &per_cpu(rt_uncached_list
, cpu
);
1478 spin_lock_bh(&ul
->lock
);
1479 list_for_each_entry(rt
, &ul
->head
, rt_uncached
) {
1480 if (rt
->dst
.dev
!= dev
)
1482 rt
->dst
.dev
= net
->loopback_dev
;
1483 dev_hold(rt
->dst
.dev
);
1486 spin_unlock_bh(&ul
->lock
);
1490 static bool rt_cache_valid(const struct rtable
*rt
)
1493 rt
->dst
.obsolete
== DST_OBSOLETE_FORCE_CHK
&&
1497 static void rt_set_nexthop(struct rtable
*rt
, __be32 daddr
,
1498 const struct fib_result
*res
,
1499 struct fib_nh_exception
*fnhe
,
1500 struct fib_info
*fi
, u16 type
, u32 itag
,
1501 const bool do_cache
)
1503 bool cached
= false;
1506 struct fib_nh
*nh
= &FIB_RES_NH(*res
);
1508 if (nh
->nh_gw
&& nh
->nh_scope
== RT_SCOPE_LINK
) {
1509 rt
->rt_gateway
= nh
->nh_gw
;
1510 rt
->rt_uses_gateway
= 1;
1512 dst_init_metrics(&rt
->dst
, fi
->fib_metrics
->metrics
, true);
1513 if (fi
->fib_metrics
!= &dst_default_metrics
) {
1514 rt
->dst
._metrics
|= DST_METRICS_REFCOUNTED
;
1515 refcount_inc(&fi
->fib_metrics
->refcnt
);
1517 #ifdef CONFIG_IP_ROUTE_CLASSID
1518 rt
->dst
.tclassid
= nh
->nh_tclassid
;
1520 rt
->dst
.lwtstate
= lwtstate_get(nh
->nh_lwtstate
);
1522 cached
= rt_bind_exception(rt
, fnhe
, daddr
, do_cache
);
1524 cached
= rt_cache_route(nh
, rt
);
1525 if (unlikely(!cached
)) {
1526 /* Routes we intend to cache in nexthop exception or
1527 * FIB nexthop have the DST_NOCACHE bit clear.
1528 * However, if we are unsuccessful at storing this
1529 * route into the cache we really need to set it.
1531 if (!rt
->rt_gateway
)
1532 rt
->rt_gateway
= daddr
;
1533 rt_add_uncached_list(rt
);
1536 rt_add_uncached_list(rt
);
1538 #ifdef CONFIG_IP_ROUTE_CLASSID
1539 #ifdef CONFIG_IP_MULTIPLE_TABLES
1540 set_class_tag(rt
, res
->tclassid
);
1542 set_class_tag(rt
, itag
);
1546 struct rtable
*rt_dst_alloc(struct net_device
*dev
,
1547 unsigned int flags
, u16 type
,
1548 bool nopolicy
, bool noxfrm
, bool will_cache
)
1552 rt
= dst_alloc(&ipv4_dst_ops
, dev
, 1, DST_OBSOLETE_FORCE_CHK
,
1553 (will_cache
? 0 : DST_HOST
) |
1554 (nopolicy
? DST_NOPOLICY
: 0) |
1555 (noxfrm
? DST_NOXFRM
: 0));
1558 rt
->rt_genid
= rt_genid_ipv4(dev_net(dev
));
1559 rt
->rt_flags
= flags
;
1561 rt
->rt_is_input
= 0;
1564 rt
->rt_mtu_locked
= 0;
1566 rt
->rt_uses_gateway
= 0;
1567 rt
->rt_table_id
= 0;
1568 INIT_LIST_HEAD(&rt
->rt_uncached
);
1570 rt
->dst
.output
= ip_output
;
1571 if (flags
& RTCF_LOCAL
)
1572 rt
->dst
.input
= ip_local_deliver
;
1577 EXPORT_SYMBOL(rt_dst_alloc
);
1579 /* called in rcu_read_lock() section */
1580 int ip_mc_validate_source(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
1581 u8 tos
, struct net_device
*dev
,
1582 struct in_device
*in_dev
, u32
*itag
)
1586 /* Primary sanity checks. */
1590 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
) ||
1591 skb
->protocol
!= htons(ETH_P_IP
))
1594 if (ipv4_is_loopback(saddr
) && !IN_DEV_ROUTE_LOCALNET(in_dev
))
1597 if (ipv4_is_zeronet(saddr
)) {
1598 if (!ipv4_is_local_multicast(daddr
))
1601 err
= fib_validate_source(skb
, saddr
, 0, tos
, 0, dev
,
1609 /* called in rcu_read_lock() section */
1610 static int ip_route_input_mc(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
1611 u8 tos
, struct net_device
*dev
, int our
)
1613 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
1614 unsigned int flags
= RTCF_MULTICAST
;
1619 err
= ip_mc_validate_source(skb
, daddr
, saddr
, tos
, dev
, in_dev
, &itag
);
1624 flags
|= RTCF_LOCAL
;
1626 rth
= rt_dst_alloc(dev_net(dev
)->loopback_dev
, flags
, RTN_MULTICAST
,
1627 IN_DEV_CONF_GET(in_dev
, NOPOLICY
), false, false);
1631 #ifdef CONFIG_IP_ROUTE_CLASSID
1632 rth
->dst
.tclassid
= itag
;
1634 rth
->dst
.output
= ip_rt_bug
;
1635 rth
->rt_is_input
= 1;
1637 #ifdef CONFIG_IP_MROUTE
1638 if (!ipv4_is_local_multicast(daddr
) && IN_DEV_MFORWARD(in_dev
))
1639 rth
->dst
.input
= ip_mr_input
;
1641 RT_CACHE_STAT_INC(in_slow_mc
);
1643 skb_dst_set(skb
, &rth
->dst
);
1648 static void ip_handle_martian_source(struct net_device
*dev
,
1649 struct in_device
*in_dev
,
1650 struct sk_buff
*skb
,
1654 RT_CACHE_STAT_INC(in_martian_src
);
1655 #ifdef CONFIG_IP_ROUTE_VERBOSE
1656 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit()) {
1658 * RFC1812 recommendation, if source is martian,
1659 * the only hint is MAC header.
1661 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1662 &daddr
, &saddr
, dev
->name
);
1663 if (dev
->hard_header_len
&& skb_mac_header_was_set(skb
)) {
1664 print_hex_dump(KERN_WARNING
, "ll header: ",
1665 DUMP_PREFIX_OFFSET
, 16, 1,
1666 skb_mac_header(skb
),
1667 dev
->hard_header_len
, true);
1673 static void set_lwt_redirect(struct rtable
*rth
)
1675 if (lwtunnel_output_redirect(rth
->dst
.lwtstate
)) {
1676 rth
->dst
.lwtstate
->orig_output
= rth
->dst
.output
;
1677 rth
->dst
.output
= lwtunnel_output
;
1680 if (lwtunnel_input_redirect(rth
->dst
.lwtstate
)) {
1681 rth
->dst
.lwtstate
->orig_input
= rth
->dst
.input
;
1682 rth
->dst
.input
= lwtunnel_input
;
1686 /* called in rcu_read_lock() section */
1687 static int __mkroute_input(struct sk_buff
*skb
,
1688 const struct fib_result
*res
,
1689 struct in_device
*in_dev
,
1690 __be32 daddr
, __be32 saddr
, u32 tos
)
1692 struct fib_nh_exception
*fnhe
;
1695 struct in_device
*out_dev
;
1699 /* get a working reference to the output device */
1700 out_dev
= __in_dev_get_rcu(FIB_RES_DEV(*res
));
1702 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1706 err
= fib_validate_source(skb
, saddr
, daddr
, tos
, FIB_RES_OIF(*res
),
1707 in_dev
->dev
, in_dev
, &itag
);
1709 ip_handle_martian_source(in_dev
->dev
, in_dev
, skb
, daddr
,
1715 do_cache
= res
->fi
&& !itag
;
1716 if (out_dev
== in_dev
&& err
&& IN_DEV_TX_REDIRECTS(out_dev
) &&
1717 skb
->protocol
== htons(ETH_P_IP
) &&
1718 (IN_DEV_SHARED_MEDIA(out_dev
) ||
1719 inet_addr_onlink(out_dev
, saddr
, FIB_RES_GW(*res
))))
1720 IPCB(skb
)->flags
|= IPSKB_DOREDIRECT
;
1722 if (skb
->protocol
!= htons(ETH_P_IP
)) {
1723 /* Not IP (i.e. ARP). Do not create route, if it is
1724 * invalid for proxy arp. DNAT routes are always valid.
1726 * Proxy arp feature have been extended to allow, ARP
1727 * replies back to the same interface, to support
1728 * Private VLAN switch technologies. See arp.c.
1730 if (out_dev
== in_dev
&&
1731 IN_DEV_PROXY_ARP_PVLAN(in_dev
) == 0) {
1737 fnhe
= find_exception(&FIB_RES_NH(*res
), daddr
);
1740 rth
= rcu_dereference(fnhe
->fnhe_rth_input
);
1742 rth
= rcu_dereference(FIB_RES_NH(*res
).nh_rth_input
);
1743 if (rt_cache_valid(rth
)) {
1744 skb_dst_set_noref(skb
, &rth
->dst
);
1749 rth
= rt_dst_alloc(out_dev
->dev
, 0, res
->type
,
1750 IN_DEV_CONF_GET(in_dev
, NOPOLICY
),
1751 IN_DEV_CONF_GET(out_dev
, NOXFRM
), do_cache
);
1757 rth
->rt_is_input
= 1;
1759 rth
->rt_table_id
= res
->table
->tb_id
;
1760 RT_CACHE_STAT_INC(in_slow_tot
);
1762 rth
->dst
.input
= ip_forward
;
1764 rt_set_nexthop(rth
, daddr
, res
, fnhe
, res
->fi
, res
->type
, itag
,
1766 set_lwt_redirect(rth
);
1767 skb_dst_set(skb
, &rth
->dst
);
1774 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1775 /* To make ICMP packets follow the right flow, the multipath hash is
1776 * calculated from the inner IP addresses.
1778 static void ip_multipath_l3_keys(const struct sk_buff
*skb
,
1779 struct flow_keys
*hash_keys
)
1781 const struct iphdr
*outer_iph
= ip_hdr(skb
);
1782 const struct iphdr
*inner_iph
;
1783 const struct icmphdr
*icmph
;
1784 struct iphdr _inner_iph
;
1785 struct icmphdr _icmph
;
1787 hash_keys
->addrs
.v4addrs
.src
= outer_iph
->saddr
;
1788 hash_keys
->addrs
.v4addrs
.dst
= outer_iph
->daddr
;
1789 if (likely(outer_iph
->protocol
!= IPPROTO_ICMP
))
1792 if (unlikely((outer_iph
->frag_off
& htons(IP_OFFSET
)) != 0))
1795 icmph
= skb_header_pointer(skb
, outer_iph
->ihl
* 4, sizeof(_icmph
),
1800 if (icmph
->type
!= ICMP_DEST_UNREACH
&&
1801 icmph
->type
!= ICMP_REDIRECT
&&
1802 icmph
->type
!= ICMP_TIME_EXCEEDED
&&
1803 icmph
->type
!= ICMP_PARAMETERPROB
)
1806 inner_iph
= skb_header_pointer(skb
,
1807 outer_iph
->ihl
* 4 + sizeof(_icmph
),
1808 sizeof(_inner_iph
), &_inner_iph
);
1811 hash_keys
->addrs
.v4addrs
.src
= inner_iph
->saddr
;
1812 hash_keys
->addrs
.v4addrs
.dst
= inner_iph
->daddr
;
1815 /* if skb is set it will be used and fl4 can be NULL */
1816 int fib_multipath_hash(const struct fib_info
*fi
, const struct flowi4
*fl4
,
1817 const struct sk_buff
*skb
)
1819 struct net
*net
= fi
->fib_net
;
1820 struct flow_keys hash_keys
;
1823 switch (net
->ipv4
.sysctl_fib_multipath_hash_policy
) {
1825 memset(&hash_keys
, 0, sizeof(hash_keys
));
1826 hash_keys
.control
.addr_type
= FLOW_DISSECTOR_KEY_IPV4_ADDRS
;
1828 ip_multipath_l3_keys(skb
, &hash_keys
);
1830 hash_keys
.addrs
.v4addrs
.src
= fl4
->saddr
;
1831 hash_keys
.addrs
.v4addrs
.dst
= fl4
->daddr
;
1835 /* skb is currently provided only when forwarding */
1837 unsigned int flag
= FLOW_DISSECTOR_F_STOP_AT_ENCAP
;
1838 struct flow_keys keys
;
1840 /* short-circuit if we already have L4 hash present */
1842 return skb_get_hash_raw(skb
) >> 1;
1843 memset(&hash_keys
, 0, sizeof(hash_keys
));
1844 skb_flow_dissect_flow_keys(skb
, &keys
, flag
);
1846 hash_keys
.control
.addr_type
= FLOW_DISSECTOR_KEY_IPV4_ADDRS
;
1847 hash_keys
.addrs
.v4addrs
.src
= keys
.addrs
.v4addrs
.src
;
1848 hash_keys
.addrs
.v4addrs
.dst
= keys
.addrs
.v4addrs
.dst
;
1849 hash_keys
.ports
.src
= keys
.ports
.src
;
1850 hash_keys
.ports
.dst
= keys
.ports
.dst
;
1851 hash_keys
.basic
.ip_proto
= keys
.basic
.ip_proto
;
1853 memset(&hash_keys
, 0, sizeof(hash_keys
));
1854 hash_keys
.control
.addr_type
= FLOW_DISSECTOR_KEY_IPV4_ADDRS
;
1855 hash_keys
.addrs
.v4addrs
.src
= fl4
->saddr
;
1856 hash_keys
.addrs
.v4addrs
.dst
= fl4
->daddr
;
1857 hash_keys
.ports
.src
= fl4
->fl4_sport
;
1858 hash_keys
.ports
.dst
= fl4
->fl4_dport
;
1859 hash_keys
.basic
.ip_proto
= fl4
->flowi4_proto
;
1863 mhash
= flow_hash_from_keys(&hash_keys
);
1867 EXPORT_SYMBOL_GPL(fib_multipath_hash
);
1868 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
1870 static int ip_mkroute_input(struct sk_buff
*skb
,
1871 struct fib_result
*res
,
1872 struct in_device
*in_dev
,
1873 __be32 daddr
, __be32 saddr
, u32 tos
)
1875 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1876 if (res
->fi
&& res
->fi
->fib_nhs
> 1) {
1877 int h
= fib_multipath_hash(res
->fi
, NULL
, skb
);
1879 fib_select_multipath(res
, h
);
1883 /* create a routing cache entry */
1884 return __mkroute_input(skb
, res
, in_dev
, daddr
, saddr
, tos
);
1888 * NOTE. We drop all the packets that has local source
1889 * addresses, because every properly looped back packet
1890 * must have correct destination already attached by output routine.
1892 * Such approach solves two big problems:
1893 * 1. Not simplex devices are handled properly.
1894 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1895 * called with rcu_read_lock()
1898 static int ip_route_input_slow(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
1899 u8 tos
, struct net_device
*dev
,
1900 struct fib_result
*res
)
1902 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
1903 struct ip_tunnel_info
*tun_info
;
1905 unsigned int flags
= 0;
1909 struct net
*net
= dev_net(dev
);
1912 /* IP on this device is disabled. */
1917 /* Check for the most weird martians, which can be not detected
1921 tun_info
= skb_tunnel_info(skb
);
1922 if (tun_info
&& !(tun_info
->mode
& IP_TUNNEL_INFO_TX
))
1923 fl4
.flowi4_tun_key
.tun_id
= tun_info
->key
.tun_id
;
1925 fl4
.flowi4_tun_key
.tun_id
= 0;
1928 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
))
1929 goto martian_source
;
1933 if (ipv4_is_lbcast(daddr
) || (saddr
== 0 && daddr
== 0))
1936 /* Accept zero addresses only to limited broadcast;
1937 * I even do not know to fix it or not. Waiting for complains :-)
1939 if (ipv4_is_zeronet(saddr
))
1940 goto martian_source
;
1942 if (ipv4_is_zeronet(daddr
))
1943 goto martian_destination
;
1945 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1946 * and call it once if daddr or/and saddr are loopback addresses
1948 if (ipv4_is_loopback(daddr
)) {
1949 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev
, net
))
1950 goto martian_destination
;
1951 } else if (ipv4_is_loopback(saddr
)) {
1952 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev
, net
))
1953 goto martian_source
;
1957 * Now we are ready to route packet.
1960 fl4
.flowi4_iif
= dev
->ifindex
;
1961 fl4
.flowi4_mark
= skb
->mark
;
1962 fl4
.flowi4_tos
= tos
;
1963 fl4
.flowi4_scope
= RT_SCOPE_UNIVERSE
;
1964 fl4
.flowi4_flags
= 0;
1967 fl4
.flowi4_uid
= sock_net_uid(net
, NULL
);
1968 err
= fib_lookup(net
, &fl4
, res
, 0);
1970 if (!IN_DEV_FORWARD(in_dev
))
1971 err
= -EHOSTUNREACH
;
1975 if (res
->type
== RTN_BROADCAST
)
1978 if (res
->type
== RTN_LOCAL
) {
1979 err
= fib_validate_source(skb
, saddr
, daddr
, tos
,
1980 0, dev
, in_dev
, &itag
);
1982 goto martian_source
;
1986 if (!IN_DEV_FORWARD(in_dev
)) {
1987 err
= -EHOSTUNREACH
;
1990 if (res
->type
!= RTN_UNICAST
)
1991 goto martian_destination
;
1993 err
= ip_mkroute_input(skb
, res
, in_dev
, daddr
, saddr
, tos
);
1997 if (skb
->protocol
!= htons(ETH_P_IP
))
2000 if (!ipv4_is_zeronet(saddr
)) {
2001 err
= fib_validate_source(skb
, saddr
, 0, tos
, 0, dev
,
2004 goto martian_source
;
2006 flags
|= RTCF_BROADCAST
;
2007 res
->type
= RTN_BROADCAST
;
2008 RT_CACHE_STAT_INC(in_brd
);
2014 rth
= rcu_dereference(FIB_RES_NH(*res
).nh_rth_input
);
2015 if (rt_cache_valid(rth
)) {
2016 skb_dst_set_noref(skb
, &rth
->dst
);
2024 rth
= rt_dst_alloc(l3mdev_master_dev_rcu(dev
) ? : net
->loopback_dev
,
2025 flags
| RTCF_LOCAL
, res
->type
,
2026 IN_DEV_CONF_GET(in_dev
, NOPOLICY
), false, do_cache
);
2030 rth
->dst
.output
= ip_rt_bug
;
2031 #ifdef CONFIG_IP_ROUTE_CLASSID
2032 rth
->dst
.tclassid
= itag
;
2034 rth
->rt_is_input
= 1;
2036 rth
->rt_table_id
= res
->table
->tb_id
;
2038 RT_CACHE_STAT_INC(in_slow_tot
);
2039 if (res
->type
== RTN_UNREACHABLE
) {
2040 rth
->dst
.input
= ip_error
;
2041 rth
->dst
.error
= -err
;
2042 rth
->rt_flags
&= ~RTCF_LOCAL
;
2046 struct fib_nh
*nh
= &FIB_RES_NH(*res
);
2048 rth
->dst
.lwtstate
= lwtstate_get(nh
->nh_lwtstate
);
2049 if (lwtunnel_input_redirect(rth
->dst
.lwtstate
)) {
2050 WARN_ON(rth
->dst
.input
== lwtunnel_input
);
2051 rth
->dst
.lwtstate
->orig_input
= rth
->dst
.input
;
2052 rth
->dst
.input
= lwtunnel_input
;
2055 if (unlikely(!rt_cache_route(nh
, rth
)))
2056 rt_add_uncached_list(rth
);
2058 skb_dst_set(skb
, &rth
->dst
);
2063 RT_CACHE_STAT_INC(in_no_route
);
2064 res
->type
= RTN_UNREACHABLE
;
2070 * Do not cache martian addresses: they should be logged (RFC1812)
2072 martian_destination
:
2073 RT_CACHE_STAT_INC(in_martian_dst
);
2074 #ifdef CONFIG_IP_ROUTE_VERBOSE
2075 if (IN_DEV_LOG_MARTIANS(in_dev
))
2076 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2077 &daddr
, &saddr
, dev
->name
);
2089 ip_handle_martian_source(dev
, in_dev
, skb
, daddr
, saddr
);
2093 int ip_route_input_noref(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2094 u8 tos
, struct net_device
*dev
)
2096 struct fib_result res
;
2099 tos
&= IPTOS_RT_MASK
;
2101 err
= ip_route_input_rcu(skb
, daddr
, saddr
, tos
, dev
, &res
);
2106 EXPORT_SYMBOL(ip_route_input_noref
);
2108 /* called with rcu_read_lock held */
2109 int ip_route_input_rcu(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2110 u8 tos
, struct net_device
*dev
, struct fib_result
*res
)
2112 /* Multicast recognition logic is moved from route cache to here.
2113 The problem was that too many Ethernet cards have broken/missing
2114 hardware multicast filters :-( As result the host on multicasting
2115 network acquires a lot of useless route cache entries, sort of
2116 SDR messages from all the world. Now we try to get rid of them.
2117 Really, provided software IP multicast filter is organized
2118 reasonably (at least, hashed), it does not result in a slowdown
2119 comparing with route cache reject entries.
2120 Note, that multicast routers are not affected, because
2121 route cache entry is created eventually.
2123 if (ipv4_is_multicast(daddr
)) {
2124 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
2129 our
= ip_check_mc_rcu(in_dev
, daddr
, saddr
,
2130 ip_hdr(skb
)->protocol
);
2132 /* check l3 master if no match yet */
2133 if ((!in_dev
|| !our
) && netif_is_l3_slave(dev
)) {
2134 struct in_device
*l3_in_dev
;
2136 l3_in_dev
= __in_dev_get_rcu(skb
->dev
);
2138 our
= ip_check_mc_rcu(l3_in_dev
, daddr
, saddr
,
2139 ip_hdr(skb
)->protocol
);
2143 #ifdef CONFIG_IP_MROUTE
2145 (!ipv4_is_local_multicast(daddr
) &&
2146 IN_DEV_MFORWARD(in_dev
))
2149 err
= ip_route_input_mc(skb
, daddr
, saddr
,
2155 return ip_route_input_slow(skb
, daddr
, saddr
, tos
, dev
, res
);
2158 /* called with rcu_read_lock() */
2159 static struct rtable
*__mkroute_output(const struct fib_result
*res
,
2160 const struct flowi4
*fl4
, int orig_oif
,
2161 struct net_device
*dev_out
,
2164 struct fib_info
*fi
= res
->fi
;
2165 struct fib_nh_exception
*fnhe
;
2166 struct in_device
*in_dev
;
2167 u16 type
= res
->type
;
2171 in_dev
= __in_dev_get_rcu(dev_out
);
2173 return ERR_PTR(-EINVAL
);
2175 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev
)))
2176 if (ipv4_is_loopback(fl4
->saddr
) &&
2177 !(dev_out
->flags
& IFF_LOOPBACK
) &&
2178 !netif_is_l3_master(dev_out
))
2179 return ERR_PTR(-EINVAL
);
2181 if (ipv4_is_lbcast(fl4
->daddr
))
2182 type
= RTN_BROADCAST
;
2183 else if (ipv4_is_multicast(fl4
->daddr
))
2184 type
= RTN_MULTICAST
;
2185 else if (ipv4_is_zeronet(fl4
->daddr
))
2186 return ERR_PTR(-EINVAL
);
2188 if (dev_out
->flags
& IFF_LOOPBACK
)
2189 flags
|= RTCF_LOCAL
;
2192 if (type
== RTN_BROADCAST
) {
2193 flags
|= RTCF_BROADCAST
| RTCF_LOCAL
;
2195 } else if (type
== RTN_MULTICAST
) {
2196 flags
|= RTCF_MULTICAST
| RTCF_LOCAL
;
2197 if (!ip_check_mc_rcu(in_dev
, fl4
->daddr
, fl4
->saddr
,
2199 flags
&= ~RTCF_LOCAL
;
2202 /* If multicast route do not exist use
2203 * default one, but do not gateway in this case.
2206 if (fi
&& res
->prefixlen
< 4)
2208 } else if ((type
== RTN_LOCAL
) && (orig_oif
!= 0) &&
2209 (orig_oif
!= dev_out
->ifindex
)) {
2210 /* For local routes that require a particular output interface
2211 * we do not want to cache the result. Caching the result
2212 * causes incorrect behaviour when there are multiple source
2213 * addresses on the interface, the end result being that if the
2214 * intended recipient is waiting on that interface for the
2215 * packet he won't receive it because it will be delivered on
2216 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2217 * be set to the loopback interface as well.
2223 do_cache
&= fi
!= NULL
;
2225 struct rtable __rcu
**prth
;
2226 struct fib_nh
*nh
= &FIB_RES_NH(*res
);
2228 fnhe
= find_exception(nh
, fl4
->daddr
);
2232 prth
= &fnhe
->fnhe_rth_output
;
2234 if (unlikely(fl4
->flowi4_flags
&
2235 FLOWI_FLAG_KNOWN_NH
&&
2237 nh
->nh_scope
== RT_SCOPE_LINK
))) {
2241 prth
= raw_cpu_ptr(nh
->nh_pcpu_rth_output
);
2243 rth
= rcu_dereference(*prth
);
2244 if (rt_cache_valid(rth
) && dst_hold_safe(&rth
->dst
))
2249 rth
= rt_dst_alloc(dev_out
, flags
, type
,
2250 IN_DEV_CONF_GET(in_dev
, NOPOLICY
),
2251 IN_DEV_CONF_GET(in_dev
, NOXFRM
),
2254 return ERR_PTR(-ENOBUFS
);
2256 rth
->rt_iif
= orig_oif
;
2258 rth
->rt_table_id
= res
->table
->tb_id
;
2260 RT_CACHE_STAT_INC(out_slow_tot
);
2262 if (flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) {
2263 if (flags
& RTCF_LOCAL
&&
2264 !(dev_out
->flags
& IFF_LOOPBACK
)) {
2265 rth
->dst
.output
= ip_mc_output
;
2266 RT_CACHE_STAT_INC(out_slow_mc
);
2268 #ifdef CONFIG_IP_MROUTE
2269 if (type
== RTN_MULTICAST
) {
2270 if (IN_DEV_MFORWARD(in_dev
) &&
2271 !ipv4_is_local_multicast(fl4
->daddr
)) {
2272 rth
->dst
.input
= ip_mr_input
;
2273 rth
->dst
.output
= ip_mc_output
;
2279 rt_set_nexthop(rth
, fl4
->daddr
, res
, fnhe
, fi
, type
, 0, do_cache
);
2280 set_lwt_redirect(rth
);
2286 * Major route resolver routine.
2289 struct rtable
*ip_route_output_key_hash(struct net
*net
, struct flowi4
*fl4
,
2290 const struct sk_buff
*skb
)
2292 __u8 tos
= RT_FL_TOS(fl4
);
2293 struct fib_result res
= {
2301 fl4
->flowi4_iif
= LOOPBACK_IFINDEX
;
2302 fl4
->flowi4_tos
= tos
& IPTOS_RT_MASK
;
2303 fl4
->flowi4_scope
= ((tos
& RTO_ONLINK
) ?
2304 RT_SCOPE_LINK
: RT_SCOPE_UNIVERSE
);
2307 rth
= ip_route_output_key_hash_rcu(net
, fl4
, &res
, skb
);
2312 EXPORT_SYMBOL_GPL(ip_route_output_key_hash
);
2314 struct rtable
*ip_route_output_key_hash_rcu(struct net
*net
, struct flowi4
*fl4
,
2315 struct fib_result
*res
,
2316 const struct sk_buff
*skb
)
2318 struct net_device
*dev_out
= NULL
;
2319 int orig_oif
= fl4
->flowi4_oif
;
2320 unsigned int flags
= 0;
2322 int err
= -ENETUNREACH
;
2325 rth
= ERR_PTR(-EINVAL
);
2326 if (ipv4_is_multicast(fl4
->saddr
) ||
2327 ipv4_is_lbcast(fl4
->saddr
) ||
2328 ipv4_is_zeronet(fl4
->saddr
))
2331 /* I removed check for oif == dev_out->oif here.
2332 It was wrong for two reasons:
2333 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2334 is assigned to multiple interfaces.
2335 2. Moreover, we are allowed to send packets with saddr
2336 of another iface. --ANK
2339 if (fl4
->flowi4_oif
== 0 &&
2340 (ipv4_is_multicast(fl4
->daddr
) ||
2341 ipv4_is_lbcast(fl4
->daddr
))) {
2342 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2343 dev_out
= __ip_dev_find(net
, fl4
->saddr
, false);
2347 /* Special hack: user can direct multicasts
2348 and limited broadcast via necessary interface
2349 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2350 This hack is not just for fun, it allows
2351 vic,vat and friends to work.
2352 They bind socket to loopback, set ttl to zero
2353 and expect that it will work.
2354 From the viewpoint of routing cache they are broken,
2355 because we are not allowed to build multicast path
2356 with loopback source addr (look, routing cache
2357 cannot know, that ttl is zero, so that packet
2358 will not leave this host and route is valid).
2359 Luckily, this hack is good workaround.
2362 fl4
->flowi4_oif
= dev_out
->ifindex
;
2366 if (!(fl4
->flowi4_flags
& FLOWI_FLAG_ANYSRC
)) {
2367 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2368 if (!__ip_dev_find(net
, fl4
->saddr
, false))
2374 if (fl4
->flowi4_oif
) {
2375 dev_out
= dev_get_by_index_rcu(net
, fl4
->flowi4_oif
);
2376 rth
= ERR_PTR(-ENODEV
);
2380 /* RACE: Check return value of inet_select_addr instead. */
2381 if (!(dev_out
->flags
& IFF_UP
) || !__in_dev_get_rcu(dev_out
)) {
2382 rth
= ERR_PTR(-ENETUNREACH
);
2385 if (ipv4_is_local_multicast(fl4
->daddr
) ||
2386 ipv4_is_lbcast(fl4
->daddr
) ||
2387 fl4
->flowi4_proto
== IPPROTO_IGMP
) {
2389 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2394 if (ipv4_is_multicast(fl4
->daddr
))
2395 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2397 else if (!fl4
->daddr
)
2398 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2404 fl4
->daddr
= fl4
->saddr
;
2406 fl4
->daddr
= fl4
->saddr
= htonl(INADDR_LOOPBACK
);
2407 dev_out
= net
->loopback_dev
;
2408 fl4
->flowi4_oif
= LOOPBACK_IFINDEX
;
2409 res
->type
= RTN_LOCAL
;
2410 flags
|= RTCF_LOCAL
;
2414 err
= fib_lookup(net
, fl4
, res
, 0);
2418 if (fl4
->flowi4_oif
&&
2419 (ipv4_is_multicast(fl4
->daddr
) ||
2420 !netif_index_is_l3_master(net
, fl4
->flowi4_oif
))) {
2421 /* Apparently, routing tables are wrong. Assume,
2422 that the destination is on link.
2425 Because we are allowed to send to iface
2426 even if it has NO routes and NO assigned
2427 addresses. When oif is specified, routing
2428 tables are looked up with only one purpose:
2429 to catch if destination is gatewayed, rather than
2430 direct. Moreover, if MSG_DONTROUTE is set,
2431 we send packet, ignoring both routing tables
2432 and ifaddr state. --ANK
2435 We could make it even if oif is unknown,
2436 likely IPv6, but we do not.
2439 if (fl4
->saddr
== 0)
2440 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2442 res
->type
= RTN_UNICAST
;
2449 if (res
->type
== RTN_LOCAL
) {
2451 if (res
->fi
->fib_prefsrc
)
2452 fl4
->saddr
= res
->fi
->fib_prefsrc
;
2454 fl4
->saddr
= fl4
->daddr
;
2457 /* L3 master device is the loopback for that domain */
2458 dev_out
= l3mdev_master_dev_rcu(FIB_RES_DEV(*res
)) ? :
2461 /* make sure orig_oif points to fib result device even
2462 * though packet rx/tx happens over loopback or l3mdev
2464 orig_oif
= FIB_RES_OIF(*res
);
2466 fl4
->flowi4_oif
= dev_out
->ifindex
;
2467 flags
|= RTCF_LOCAL
;
2471 fib_select_path(net
, res
, fl4
, skb
);
2473 dev_out
= FIB_RES_DEV(*res
);
2474 fl4
->flowi4_oif
= dev_out
->ifindex
;
2478 rth
= __mkroute_output(res
, fl4
, orig_oif
, dev_out
, flags
);
2484 static struct dst_entry
*ipv4_blackhole_dst_check(struct dst_entry
*dst
, u32 cookie
)
2489 static unsigned int ipv4_blackhole_mtu(const struct dst_entry
*dst
)
2491 unsigned int mtu
= dst_metric_raw(dst
, RTAX_MTU
);
2493 return mtu
? : dst
->dev
->mtu
;
2496 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry
*dst
, struct sock
*sk
,
2497 struct sk_buff
*skb
, u32 mtu
)
2501 static void ipv4_rt_blackhole_redirect(struct dst_entry
*dst
, struct sock
*sk
,
2502 struct sk_buff
*skb
)
2506 static u32
*ipv4_rt_blackhole_cow_metrics(struct dst_entry
*dst
,
2512 static struct dst_ops ipv4_dst_blackhole_ops
= {
2514 .check
= ipv4_blackhole_dst_check
,
2515 .mtu
= ipv4_blackhole_mtu
,
2516 .default_advmss
= ipv4_default_advmss
,
2517 .update_pmtu
= ipv4_rt_blackhole_update_pmtu
,
2518 .redirect
= ipv4_rt_blackhole_redirect
,
2519 .cow_metrics
= ipv4_rt_blackhole_cow_metrics
,
2520 .neigh_lookup
= ipv4_neigh_lookup
,
2523 struct dst_entry
*ipv4_blackhole_route(struct net
*net
, struct dst_entry
*dst_orig
)
2525 struct rtable
*ort
= (struct rtable
*) dst_orig
;
2528 rt
= dst_alloc(&ipv4_dst_blackhole_ops
, NULL
, 1, DST_OBSOLETE_DEAD
, 0);
2530 struct dst_entry
*new = &rt
->dst
;
2533 new->input
= dst_discard
;
2534 new->output
= dst_discard_out
;
2536 new->dev
= net
->loopback_dev
;
2540 rt
->rt_is_input
= ort
->rt_is_input
;
2541 rt
->rt_iif
= ort
->rt_iif
;
2542 rt
->rt_pmtu
= ort
->rt_pmtu
;
2543 rt
->rt_mtu_locked
= ort
->rt_mtu_locked
;
2545 rt
->rt_genid
= rt_genid_ipv4(net
);
2546 rt
->rt_flags
= ort
->rt_flags
;
2547 rt
->rt_type
= ort
->rt_type
;
2548 rt
->rt_gateway
= ort
->rt_gateway
;
2549 rt
->rt_uses_gateway
= ort
->rt_uses_gateway
;
2551 INIT_LIST_HEAD(&rt
->rt_uncached
);
2554 dst_release(dst_orig
);
2556 return rt
? &rt
->dst
: ERR_PTR(-ENOMEM
);
2559 struct rtable
*ip_route_output_flow(struct net
*net
, struct flowi4
*flp4
,
2560 const struct sock
*sk
)
2562 struct rtable
*rt
= __ip_route_output_key(net
, flp4
);
2567 if (flp4
->flowi4_proto
)
2568 rt
= (struct rtable
*)xfrm_lookup_route(net
, &rt
->dst
,
2569 flowi4_to_flowi(flp4
),
2574 EXPORT_SYMBOL_GPL(ip_route_output_flow
);
2576 /* called with rcu_read_lock held */
2577 static int rt_fill_info(struct net
*net
, __be32 dst
, __be32 src
, u32 table_id
,
2578 struct flowi4
*fl4
, struct sk_buff
*skb
, u32 portid
,
2581 struct rtable
*rt
= skb_rtable(skb
);
2583 struct nlmsghdr
*nlh
;
2584 unsigned long expires
= 0;
2586 u32 metrics
[RTAX_MAX
];
2588 nlh
= nlmsg_put(skb
, portid
, seq
, RTM_NEWROUTE
, sizeof(*r
), 0);
2592 r
= nlmsg_data(nlh
);
2593 r
->rtm_family
= AF_INET
;
2594 r
->rtm_dst_len
= 32;
2596 r
->rtm_tos
= fl4
->flowi4_tos
;
2597 r
->rtm_table
= table_id
< 256 ? table_id
: RT_TABLE_COMPAT
;
2598 if (nla_put_u32(skb
, RTA_TABLE
, table_id
))
2599 goto nla_put_failure
;
2600 r
->rtm_type
= rt
->rt_type
;
2601 r
->rtm_scope
= RT_SCOPE_UNIVERSE
;
2602 r
->rtm_protocol
= RTPROT_UNSPEC
;
2603 r
->rtm_flags
= (rt
->rt_flags
& ~0xFFFF) | RTM_F_CLONED
;
2604 if (rt
->rt_flags
& RTCF_NOTIFY
)
2605 r
->rtm_flags
|= RTM_F_NOTIFY
;
2606 if (IPCB(skb
)->flags
& IPSKB_DOREDIRECT
)
2607 r
->rtm_flags
|= RTCF_DOREDIRECT
;
2609 if (nla_put_in_addr(skb
, RTA_DST
, dst
))
2610 goto nla_put_failure
;
2612 r
->rtm_src_len
= 32;
2613 if (nla_put_in_addr(skb
, RTA_SRC
, src
))
2614 goto nla_put_failure
;
2617 nla_put_u32(skb
, RTA_OIF
, rt
->dst
.dev
->ifindex
))
2618 goto nla_put_failure
;
2619 #ifdef CONFIG_IP_ROUTE_CLASSID
2620 if (rt
->dst
.tclassid
&&
2621 nla_put_u32(skb
, RTA_FLOW
, rt
->dst
.tclassid
))
2622 goto nla_put_failure
;
2624 if (!rt_is_input_route(rt
) &&
2625 fl4
->saddr
!= src
) {
2626 if (nla_put_in_addr(skb
, RTA_PREFSRC
, fl4
->saddr
))
2627 goto nla_put_failure
;
2629 if (rt
->rt_uses_gateway
&&
2630 nla_put_in_addr(skb
, RTA_GATEWAY
, rt
->rt_gateway
))
2631 goto nla_put_failure
;
2633 expires
= rt
->dst
.expires
;
2635 unsigned long now
= jiffies
;
2637 if (time_before(now
, expires
))
2643 memcpy(metrics
, dst_metrics_ptr(&rt
->dst
), sizeof(metrics
));
2644 if (rt
->rt_pmtu
&& expires
)
2645 metrics
[RTAX_MTU
- 1] = rt
->rt_pmtu
;
2646 if (rt
->rt_mtu_locked
&& expires
)
2647 metrics
[RTAX_LOCK
- 1] |= BIT(RTAX_MTU
);
2648 if (rtnetlink_put_metrics(skb
, metrics
) < 0)
2649 goto nla_put_failure
;
2651 if (fl4
->flowi4_mark
&&
2652 nla_put_u32(skb
, RTA_MARK
, fl4
->flowi4_mark
))
2653 goto nla_put_failure
;
2655 if (!uid_eq(fl4
->flowi4_uid
, INVALID_UID
) &&
2656 nla_put_u32(skb
, RTA_UID
,
2657 from_kuid_munged(current_user_ns(), fl4
->flowi4_uid
)))
2658 goto nla_put_failure
;
2660 error
= rt
->dst
.error
;
2662 if (rt_is_input_route(rt
)) {
2663 #ifdef CONFIG_IP_MROUTE
2664 if (ipv4_is_multicast(dst
) && !ipv4_is_local_multicast(dst
) &&
2665 IPV4_DEVCONF_ALL(net
, MC_FORWARDING
)) {
2666 int err
= ipmr_get_route(net
, skb
,
2667 fl4
->saddr
, fl4
->daddr
,
2673 goto nla_put_failure
;
2677 if (nla_put_u32(skb
, RTA_IIF
, skb
->dev
->ifindex
))
2678 goto nla_put_failure
;
2681 if (rtnl_put_cacheinfo(skb
, &rt
->dst
, 0, expires
, error
) < 0)
2682 goto nla_put_failure
;
2684 nlmsg_end(skb
, nlh
);
2688 nlmsg_cancel(skb
, nlh
);
2692 static int inet_rtm_getroute(struct sk_buff
*in_skb
, struct nlmsghdr
*nlh
,
2693 struct netlink_ext_ack
*extack
)
2695 struct net
*net
= sock_net(in_skb
->sk
);
2697 struct nlattr
*tb
[RTA_MAX
+1];
2698 struct fib_result res
= {};
2699 struct rtable
*rt
= NULL
;
2706 struct sk_buff
*skb
;
2707 u32 table_id
= RT_TABLE_MAIN
;
2710 err
= nlmsg_parse(nlh
, sizeof(*rtm
), tb
, RTA_MAX
, rtm_ipv4_policy
,
2715 rtm
= nlmsg_data(nlh
);
2717 skb
= alloc_skb(NLMSG_GOODSIZE
, GFP_KERNEL
);
2723 /* Reserve room for dummy headers, this skb can pass
2724 through good chunk of routing engine.
2726 skb_reset_mac_header(skb
);
2727 skb_reset_network_header(skb
);
2729 src
= tb
[RTA_SRC
] ? nla_get_in_addr(tb
[RTA_SRC
]) : 0;
2730 dst
= tb
[RTA_DST
] ? nla_get_in_addr(tb
[RTA_DST
]) : 0;
2731 iif
= tb
[RTA_IIF
] ? nla_get_u32(tb
[RTA_IIF
]) : 0;
2732 mark
= tb
[RTA_MARK
] ? nla_get_u32(tb
[RTA_MARK
]) : 0;
2734 uid
= make_kuid(current_user_ns(), nla_get_u32(tb
[RTA_UID
]));
2736 uid
= (iif
? INVALID_UID
: current_uid());
2738 /* Bugfix: need to give ip_route_input enough of an IP header to
2741 ip_hdr(skb
)->protocol
= IPPROTO_UDP
;
2742 ip_hdr(skb
)->saddr
= src
;
2743 ip_hdr(skb
)->daddr
= dst
;
2745 skb_reserve(skb
, MAX_HEADER
+ sizeof(struct iphdr
));
2747 memset(&fl4
, 0, sizeof(fl4
));
2750 fl4
.flowi4_tos
= rtm
->rtm_tos
;
2751 fl4
.flowi4_oif
= tb
[RTA_OIF
] ? nla_get_u32(tb
[RTA_OIF
]) : 0;
2752 fl4
.flowi4_mark
= mark
;
2753 fl4
.flowi4_uid
= uid
;
2758 struct net_device
*dev
;
2760 dev
= dev_get_by_index_rcu(net
, iif
);
2766 skb
->protocol
= htons(ETH_P_IP
);
2769 err
= ip_route_input_rcu(skb
, dst
, src
, rtm
->rtm_tos
,
2772 rt
= skb_rtable(skb
);
2773 if (err
== 0 && rt
->dst
.error
)
2774 err
= -rt
->dst
.error
;
2776 fl4
.flowi4_iif
= LOOPBACK_IFINDEX
;
2777 rt
= ip_route_output_key_hash_rcu(net
, &fl4
, &res
, skb
);
2782 skb_dst_set(skb
, &rt
->dst
);
2788 if (rtm
->rtm_flags
& RTM_F_NOTIFY
)
2789 rt
->rt_flags
|= RTCF_NOTIFY
;
2791 if (rtm
->rtm_flags
& RTM_F_LOOKUP_TABLE
)
2792 table_id
= rt
->rt_table_id
;
2794 if (rtm
->rtm_flags
& RTM_F_FIB_MATCH
) {
2796 err
= fib_props
[res
.type
].error
;
2798 err
= -EHOSTUNREACH
;
2801 err
= fib_dump_info(skb
, NETLINK_CB(in_skb
).portid
,
2802 nlh
->nlmsg_seq
, RTM_NEWROUTE
, table_id
,
2803 rt
->rt_type
, res
.prefix
, res
.prefixlen
,
2804 fl4
.flowi4_tos
, res
.fi
, 0);
2806 err
= rt_fill_info(net
, dst
, src
, table_id
, &fl4
, skb
,
2807 NETLINK_CB(in_skb
).portid
, nlh
->nlmsg_seq
);
2814 err
= rtnl_unicast(skb
, net
, NETLINK_CB(in_skb
).portid
);
2824 void ip_rt_multicast_event(struct in_device
*in_dev
)
2826 rt_cache_flush(dev_net(in_dev
->dev
));
2829 #ifdef CONFIG_SYSCTL
2830 static int ip_rt_gc_interval __read_mostly
= 60 * HZ
;
2831 static int ip_rt_gc_min_interval __read_mostly
= HZ
/ 2;
2832 static int ip_rt_gc_elasticity __read_mostly
= 8;
2834 static int ipv4_sysctl_rtcache_flush(struct ctl_table
*__ctl
, int write
,
2835 void __user
*buffer
,
2836 size_t *lenp
, loff_t
*ppos
)
2838 struct net
*net
= (struct net
*)__ctl
->extra1
;
2841 rt_cache_flush(net
);
2842 fnhe_genid_bump(net
);
2849 static struct ctl_table ipv4_route_table
[] = {
2851 .procname
= "gc_thresh",
2852 .data
= &ipv4_dst_ops
.gc_thresh
,
2853 .maxlen
= sizeof(int),
2855 .proc_handler
= proc_dointvec
,
2858 .procname
= "max_size",
2859 .data
= &ip_rt_max_size
,
2860 .maxlen
= sizeof(int),
2862 .proc_handler
= proc_dointvec
,
2865 /* Deprecated. Use gc_min_interval_ms */
2867 .procname
= "gc_min_interval",
2868 .data
= &ip_rt_gc_min_interval
,
2869 .maxlen
= sizeof(int),
2871 .proc_handler
= proc_dointvec_jiffies
,
2874 .procname
= "gc_min_interval_ms",
2875 .data
= &ip_rt_gc_min_interval
,
2876 .maxlen
= sizeof(int),
2878 .proc_handler
= proc_dointvec_ms_jiffies
,
2881 .procname
= "gc_timeout",
2882 .data
= &ip_rt_gc_timeout
,
2883 .maxlen
= sizeof(int),
2885 .proc_handler
= proc_dointvec_jiffies
,
2888 .procname
= "gc_interval",
2889 .data
= &ip_rt_gc_interval
,
2890 .maxlen
= sizeof(int),
2892 .proc_handler
= proc_dointvec_jiffies
,
2895 .procname
= "redirect_load",
2896 .data
= &ip_rt_redirect_load
,
2897 .maxlen
= sizeof(int),
2899 .proc_handler
= proc_dointvec
,
2902 .procname
= "redirect_number",
2903 .data
= &ip_rt_redirect_number
,
2904 .maxlen
= sizeof(int),
2906 .proc_handler
= proc_dointvec
,
2909 .procname
= "redirect_silence",
2910 .data
= &ip_rt_redirect_silence
,
2911 .maxlen
= sizeof(int),
2913 .proc_handler
= proc_dointvec
,
2916 .procname
= "error_cost",
2917 .data
= &ip_rt_error_cost
,
2918 .maxlen
= sizeof(int),
2920 .proc_handler
= proc_dointvec
,
2923 .procname
= "error_burst",
2924 .data
= &ip_rt_error_burst
,
2925 .maxlen
= sizeof(int),
2927 .proc_handler
= proc_dointvec
,
2930 .procname
= "gc_elasticity",
2931 .data
= &ip_rt_gc_elasticity
,
2932 .maxlen
= sizeof(int),
2934 .proc_handler
= proc_dointvec
,
2937 .procname
= "mtu_expires",
2938 .data
= &ip_rt_mtu_expires
,
2939 .maxlen
= sizeof(int),
2941 .proc_handler
= proc_dointvec_jiffies
,
2944 .procname
= "min_pmtu",
2945 .data
= &ip_rt_min_pmtu
,
2946 .maxlen
= sizeof(int),
2948 .proc_handler
= proc_dointvec_minmax
,
2949 .extra1
= &ip_min_valid_pmtu
,
2952 .procname
= "min_adv_mss",
2953 .data
= &ip_rt_min_advmss
,
2954 .maxlen
= sizeof(int),
2956 .proc_handler
= proc_dointvec
,
2961 static struct ctl_table ipv4_route_flush_table
[] = {
2963 .procname
= "flush",
2964 .maxlen
= sizeof(int),
2966 .proc_handler
= ipv4_sysctl_rtcache_flush
,
2971 static __net_init
int sysctl_route_net_init(struct net
*net
)
2973 struct ctl_table
*tbl
;
2975 tbl
= ipv4_route_flush_table
;
2976 if (!net_eq(net
, &init_net
)) {
2977 tbl
= kmemdup(tbl
, sizeof(ipv4_route_flush_table
), GFP_KERNEL
);
2981 /* Don't export sysctls to unprivileged users */
2982 if (net
->user_ns
!= &init_user_ns
)
2983 tbl
[0].procname
= NULL
;
2985 tbl
[0].extra1
= net
;
2987 net
->ipv4
.route_hdr
= register_net_sysctl(net
, "net/ipv4/route", tbl
);
2988 if (!net
->ipv4
.route_hdr
)
2993 if (tbl
!= ipv4_route_flush_table
)
2999 static __net_exit
void sysctl_route_net_exit(struct net
*net
)
3001 struct ctl_table
*tbl
;
3003 tbl
= net
->ipv4
.route_hdr
->ctl_table_arg
;
3004 unregister_net_sysctl_table(net
->ipv4
.route_hdr
);
3005 BUG_ON(tbl
== ipv4_route_flush_table
);
3009 static __net_initdata
struct pernet_operations sysctl_route_ops
= {
3010 .init
= sysctl_route_net_init
,
3011 .exit
= sysctl_route_net_exit
,
3015 static __net_init
int rt_genid_init(struct net
*net
)
3017 atomic_set(&net
->ipv4
.rt_genid
, 0);
3018 atomic_set(&net
->fnhe_genid
, 0);
3019 atomic_set(&net
->ipv4
.dev_addr_genid
, get_random_int());
3023 static __net_initdata
struct pernet_operations rt_genid_ops
= {
3024 .init
= rt_genid_init
,
3027 static int __net_init
ipv4_inetpeer_init(struct net
*net
)
3029 struct inet_peer_base
*bp
= kmalloc(sizeof(*bp
), GFP_KERNEL
);
3033 inet_peer_base_init(bp
);
3034 net
->ipv4
.peers
= bp
;
3038 static void __net_exit
ipv4_inetpeer_exit(struct net
*net
)
3040 struct inet_peer_base
*bp
= net
->ipv4
.peers
;
3042 net
->ipv4
.peers
= NULL
;
3043 inetpeer_invalidate_tree(bp
);
3047 static __net_initdata
struct pernet_operations ipv4_inetpeer_ops
= {
3048 .init
= ipv4_inetpeer_init
,
3049 .exit
= ipv4_inetpeer_exit
,
3052 #ifdef CONFIG_IP_ROUTE_CLASSID
3053 struct ip_rt_acct __percpu
*ip_rt_acct __read_mostly
;
3054 #endif /* CONFIG_IP_ROUTE_CLASSID */
3056 int __init
ip_rt_init(void)
3060 ip_idents
= kmalloc(IP_IDENTS_SZ
* sizeof(*ip_idents
), GFP_KERNEL
);
3062 panic("IP: failed to allocate ip_idents\n");
3064 prandom_bytes(ip_idents
, IP_IDENTS_SZ
* sizeof(*ip_idents
));
3066 ip_tstamps
= kcalloc(IP_IDENTS_SZ
, sizeof(*ip_tstamps
), GFP_KERNEL
);
3068 panic("IP: failed to allocate ip_tstamps\n");
3070 for_each_possible_cpu(cpu
) {
3071 struct uncached_list
*ul
= &per_cpu(rt_uncached_list
, cpu
);
3073 INIT_LIST_HEAD(&ul
->head
);
3074 spin_lock_init(&ul
->lock
);
3076 #ifdef CONFIG_IP_ROUTE_CLASSID
3077 ip_rt_acct
= __alloc_percpu(256 * sizeof(struct ip_rt_acct
), __alignof__(struct ip_rt_acct
));
3079 panic("IP: failed to allocate ip_rt_acct\n");
3082 ipv4_dst_ops
.kmem_cachep
=
3083 kmem_cache_create("ip_dst_cache", sizeof(struct rtable
), 0,
3084 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3086 ipv4_dst_blackhole_ops
.kmem_cachep
= ipv4_dst_ops
.kmem_cachep
;
3088 if (dst_entries_init(&ipv4_dst_ops
) < 0)
3089 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3091 if (dst_entries_init(&ipv4_dst_blackhole_ops
) < 0)
3092 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3094 ipv4_dst_ops
.gc_thresh
= ~0;
3095 ip_rt_max_size
= INT_MAX
;
3100 if (ip_rt_proc_init())
3101 pr_err("Unable to create route proc files\n");
3106 rtnl_register(PF_INET
, RTM_GETROUTE
, inet_rtm_getroute
, NULL
,
3107 RTNL_FLAG_DOIT_UNLOCKED
);
3109 #ifdef CONFIG_SYSCTL
3110 register_pernet_subsys(&sysctl_route_ops
);
3112 register_pernet_subsys(&rt_genid_ops
);
3113 register_pernet_subsys(&ipv4_inetpeer_ops
);
3117 #ifdef CONFIG_SYSCTL
3119 * We really need to sanitize the damn ipv4 init order, then all
3120 * this nonsense will go away.
3122 void __init
ip_static_sysctl_init(void)
3124 register_net_sysctl(&init_net
, "net/ipv4/route", ipv4_route_table
);