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 #include <linux/module.h>
66 #include <asm/uaccess.h>
67 #include <asm/system.h>
68 #include <linux/bitops.h>
69 #include <linux/types.h>
70 #include <linux/kernel.h>
72 #include <linux/bootmem.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/workqueue.h>
83 #include <linux/skbuff.h>
84 #include <linux/inetdevice.h>
85 #include <linux/igmp.h>
86 #include <linux/pkt_sched.h>
87 #include <linux/mroute.h>
88 #include <linux/netfilter_ipv4.h>
89 #include <linux/random.h>
90 #include <linux/jhash.h>
91 #include <linux/rcupdate.h>
92 #include <linux/times.h>
93 #include <linux/slab.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/netevent.h>
107 #include <net/rtnetlink.h>
109 #include <linux/sysctl.h>
112 #define RT_FL_TOS(oldflp) \
113 ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
115 #define IP_MAX_MTU 0xFFF0
117 #define RT_GC_TIMEOUT (300*HZ)
119 static int ip_rt_max_size
;
120 static int ip_rt_gc_timeout __read_mostly
= RT_GC_TIMEOUT
;
121 static int ip_rt_gc_interval __read_mostly
= 60 * HZ
;
122 static int ip_rt_gc_min_interval __read_mostly
= HZ
/ 2;
123 static int ip_rt_redirect_number __read_mostly
= 9;
124 static int ip_rt_redirect_load __read_mostly
= HZ
/ 50;
125 static int ip_rt_redirect_silence __read_mostly
= ((HZ
/ 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly
= HZ
;
127 static int ip_rt_error_burst __read_mostly
= 5 * HZ
;
128 static int ip_rt_gc_elasticity __read_mostly
= 8;
129 static int ip_rt_mtu_expires __read_mostly
= 10 * 60 * HZ
;
130 static int ip_rt_min_pmtu __read_mostly
= 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly
= 256;
132 static int rt_chain_length_max __read_mostly
= 20;
134 static struct delayed_work expires_work
;
135 static unsigned long expires_ljiffies
;
138 * Interface to generic destination cache.
141 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
);
142 static void ipv4_dst_destroy(struct dst_entry
*dst
);
143 static void ipv4_dst_ifdown(struct dst_entry
*dst
,
144 struct net_device
*dev
, int how
);
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
, u32 mtu
);
148 static int rt_garbage_collect(struct dst_ops
*ops
);
151 static struct dst_ops ipv4_dst_ops
= {
153 .protocol
= cpu_to_be16(ETH_P_IP
),
154 .gc
= rt_garbage_collect
,
155 .check
= ipv4_dst_check
,
156 .destroy
= ipv4_dst_destroy
,
157 .ifdown
= ipv4_dst_ifdown
,
158 .negative_advice
= ipv4_negative_advice
,
159 .link_failure
= ipv4_link_failure
,
160 .update_pmtu
= ip_rt_update_pmtu
,
161 .local_out
= __ip_local_out
,
162 .entries
= ATOMIC_INIT(0),
165 #define ECN_OR_COST(class) TC_PRIO_##class
167 const __u8 ip_tos2prio
[16] = {
171 ECN_OR_COST(BESTEFFORT
),
177 ECN_OR_COST(INTERACTIVE
),
179 ECN_OR_COST(INTERACTIVE
),
180 TC_PRIO_INTERACTIVE_BULK
,
181 ECN_OR_COST(INTERACTIVE_BULK
),
182 TC_PRIO_INTERACTIVE_BULK
,
183 ECN_OR_COST(INTERACTIVE_BULK
)
191 /* The locking scheme is rather straight forward:
193 * 1) Read-Copy Update protects the buckets of the central route hash.
194 * 2) Only writers remove entries, and they hold the lock
195 * as they look at rtable reference counts.
196 * 3) Only readers acquire references to rtable entries,
197 * they do so with atomic increments and with the
201 struct rt_hash_bucket
{
202 struct rtable
*chain
;
205 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
206 defined(CONFIG_PROVE_LOCKING)
208 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
209 * The size of this table is a power of two and depends on the number of CPUS.
210 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
212 #ifdef CONFIG_LOCKDEP
213 # define RT_HASH_LOCK_SZ 256
216 # define RT_HASH_LOCK_SZ 4096
218 # define RT_HASH_LOCK_SZ 2048
220 # define RT_HASH_LOCK_SZ 1024
222 # define RT_HASH_LOCK_SZ 512
224 # define RT_HASH_LOCK_SZ 256
228 static spinlock_t
*rt_hash_locks
;
229 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
231 static __init
void rt_hash_lock_init(void)
235 rt_hash_locks
= kmalloc(sizeof(spinlock_t
) * RT_HASH_LOCK_SZ
,
238 panic("IP: failed to allocate rt_hash_locks\n");
240 for (i
= 0; i
< RT_HASH_LOCK_SZ
; i
++)
241 spin_lock_init(&rt_hash_locks
[i
]);
244 # define rt_hash_lock_addr(slot) NULL
246 static inline void rt_hash_lock_init(void)
251 static struct rt_hash_bucket
*rt_hash_table __read_mostly
;
252 static unsigned rt_hash_mask __read_mostly
;
253 static unsigned int rt_hash_log __read_mostly
;
255 static DEFINE_PER_CPU(struct rt_cache_stat
, rt_cache_stat
);
256 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
258 static inline unsigned int rt_hash(__be32 daddr
, __be32 saddr
, int idx
,
261 return jhash_3words((__force u32
)daddr
, (__force u32
)saddr
,
266 static inline int rt_genid(struct net
*net
)
268 return atomic_read(&net
->ipv4
.rt_genid
);
271 #ifdef CONFIG_PROC_FS
272 struct rt_cache_iter_state
{
273 struct seq_net_private p
;
278 static struct rtable
*rt_cache_get_first(struct seq_file
*seq
)
280 struct rt_cache_iter_state
*st
= seq
->private;
281 struct rtable
*r
= NULL
;
283 for (st
->bucket
= rt_hash_mask
; st
->bucket
>= 0; --st
->bucket
) {
284 if (!rt_hash_table
[st
->bucket
].chain
)
287 r
= rcu_dereference_bh(rt_hash_table
[st
->bucket
].chain
);
289 if (dev_net(r
->dst
.dev
) == seq_file_net(seq
) &&
290 r
->rt_genid
== st
->genid
)
292 r
= rcu_dereference_bh(r
->dst
.rt_next
);
294 rcu_read_unlock_bh();
299 static struct rtable
*__rt_cache_get_next(struct seq_file
*seq
,
302 struct rt_cache_iter_state
*st
= seq
->private;
306 rcu_read_unlock_bh();
308 if (--st
->bucket
< 0)
310 } while (!rt_hash_table
[st
->bucket
].chain
);
312 r
= rt_hash_table
[st
->bucket
].chain
;
314 return rcu_dereference_bh(r
);
317 static struct rtable
*rt_cache_get_next(struct seq_file
*seq
,
320 struct rt_cache_iter_state
*st
= seq
->private;
321 while ((r
= __rt_cache_get_next(seq
, r
)) != NULL
) {
322 if (dev_net(r
->dst
.dev
) != seq_file_net(seq
))
324 if (r
->rt_genid
== st
->genid
)
330 static struct rtable
*rt_cache_get_idx(struct seq_file
*seq
, loff_t pos
)
332 struct rtable
*r
= rt_cache_get_first(seq
);
335 while (pos
&& (r
= rt_cache_get_next(seq
, r
)))
337 return pos
? NULL
: r
;
340 static void *rt_cache_seq_start(struct seq_file
*seq
, loff_t
*pos
)
342 struct rt_cache_iter_state
*st
= seq
->private;
344 return rt_cache_get_idx(seq
, *pos
- 1);
345 st
->genid
= rt_genid(seq_file_net(seq
));
346 return SEQ_START_TOKEN
;
349 static void *rt_cache_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
353 if (v
== SEQ_START_TOKEN
)
354 r
= rt_cache_get_first(seq
);
356 r
= rt_cache_get_next(seq
, v
);
361 static void rt_cache_seq_stop(struct seq_file
*seq
, void *v
)
363 if (v
&& v
!= SEQ_START_TOKEN
)
364 rcu_read_unlock_bh();
367 static int rt_cache_seq_show(struct seq_file
*seq
, void *v
)
369 if (v
== SEQ_START_TOKEN
)
370 seq_printf(seq
, "%-127s\n",
371 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
372 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
375 struct rtable
*r
= v
;
378 seq_printf(seq
, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
379 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
380 r
->dst
.dev
? r
->dst
.dev
->name
: "*",
381 (__force u32
)r
->rt_dst
,
382 (__force u32
)r
->rt_gateway
,
383 r
->rt_flags
, atomic_read(&r
->dst
.__refcnt
),
384 r
->dst
.__use
, 0, (__force u32
)r
->rt_src
,
385 (dst_metric(&r
->dst
, RTAX_ADVMSS
) ?
386 (int)dst_metric(&r
->dst
, RTAX_ADVMSS
) + 40 : 0),
387 dst_metric(&r
->dst
, RTAX_WINDOW
),
388 (int)((dst_metric(&r
->dst
, RTAX_RTT
) >> 3) +
389 dst_metric(&r
->dst
, RTAX_RTTVAR
)),
391 r
->dst
.hh
? atomic_read(&r
->dst
.hh
->hh_refcnt
) : -1,
392 r
->dst
.hh
? (r
->dst
.hh
->hh_output
==
394 r
->rt_spec_dst
, &len
);
396 seq_printf(seq
, "%*s\n", 127 - len
, "");
401 static const struct seq_operations rt_cache_seq_ops
= {
402 .start
= rt_cache_seq_start
,
403 .next
= rt_cache_seq_next
,
404 .stop
= rt_cache_seq_stop
,
405 .show
= rt_cache_seq_show
,
408 static int rt_cache_seq_open(struct inode
*inode
, struct file
*file
)
410 return seq_open_net(inode
, file
, &rt_cache_seq_ops
,
411 sizeof(struct rt_cache_iter_state
));
414 static const struct file_operations rt_cache_seq_fops
= {
415 .owner
= THIS_MODULE
,
416 .open
= rt_cache_seq_open
,
419 .release
= seq_release_net
,
423 static void *rt_cpu_seq_start(struct seq_file
*seq
, loff_t
*pos
)
428 return SEQ_START_TOKEN
;
430 for (cpu
= *pos
-1; cpu
< nr_cpu_ids
; ++cpu
) {
431 if (!cpu_possible(cpu
))
434 return &per_cpu(rt_cache_stat
, cpu
);
439 static void *rt_cpu_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
443 for (cpu
= *pos
; cpu
< nr_cpu_ids
; ++cpu
) {
444 if (!cpu_possible(cpu
))
447 return &per_cpu(rt_cache_stat
, cpu
);
453 static void rt_cpu_seq_stop(struct seq_file
*seq
, void *v
)
458 static int rt_cpu_seq_show(struct seq_file
*seq
, void *v
)
460 struct rt_cache_stat
*st
= v
;
462 if (v
== SEQ_START_TOKEN
) {
463 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");
467 seq_printf(seq
,"%08x %08x %08x %08x %08x %08x %08x %08x "
468 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
469 atomic_read(&ipv4_dst_ops
.entries
),
492 static const struct seq_operations rt_cpu_seq_ops
= {
493 .start
= rt_cpu_seq_start
,
494 .next
= rt_cpu_seq_next
,
495 .stop
= rt_cpu_seq_stop
,
496 .show
= rt_cpu_seq_show
,
500 static int rt_cpu_seq_open(struct inode
*inode
, struct file
*file
)
502 return seq_open(file
, &rt_cpu_seq_ops
);
505 static const struct file_operations rt_cpu_seq_fops
= {
506 .owner
= THIS_MODULE
,
507 .open
= rt_cpu_seq_open
,
510 .release
= seq_release
,
513 #ifdef CONFIG_NET_CLS_ROUTE
514 static int rt_acct_proc_show(struct seq_file
*m
, void *v
)
516 struct ip_rt_acct
*dst
, *src
;
519 dst
= kcalloc(256, sizeof(struct ip_rt_acct
), GFP_KERNEL
);
523 for_each_possible_cpu(i
) {
524 src
= (struct ip_rt_acct
*)per_cpu_ptr(ip_rt_acct
, i
);
525 for (j
= 0; j
< 256; j
++) {
526 dst
[j
].o_bytes
+= src
[j
].o_bytes
;
527 dst
[j
].o_packets
+= src
[j
].o_packets
;
528 dst
[j
].i_bytes
+= src
[j
].i_bytes
;
529 dst
[j
].i_packets
+= src
[j
].i_packets
;
533 seq_write(m
, dst
, 256 * sizeof(struct ip_rt_acct
));
538 static int rt_acct_proc_open(struct inode
*inode
, struct file
*file
)
540 return single_open(file
, rt_acct_proc_show
, NULL
);
543 static const struct file_operations rt_acct_proc_fops
= {
544 .owner
= THIS_MODULE
,
545 .open
= rt_acct_proc_open
,
548 .release
= single_release
,
552 static int __net_init
ip_rt_do_proc_init(struct net
*net
)
554 struct proc_dir_entry
*pde
;
556 pde
= proc_net_fops_create(net
, "rt_cache", S_IRUGO
,
561 pde
= proc_create("rt_cache", S_IRUGO
,
562 net
->proc_net_stat
, &rt_cpu_seq_fops
);
566 #ifdef CONFIG_NET_CLS_ROUTE
567 pde
= proc_create("rt_acct", 0, net
->proc_net
, &rt_acct_proc_fops
);
573 #ifdef CONFIG_NET_CLS_ROUTE
575 remove_proc_entry("rt_cache", net
->proc_net_stat
);
578 remove_proc_entry("rt_cache", net
->proc_net
);
583 static void __net_exit
ip_rt_do_proc_exit(struct net
*net
)
585 remove_proc_entry("rt_cache", net
->proc_net_stat
);
586 remove_proc_entry("rt_cache", net
->proc_net
);
587 #ifdef CONFIG_NET_CLS_ROUTE
588 remove_proc_entry("rt_acct", net
->proc_net
);
592 static struct pernet_operations ip_rt_proc_ops __net_initdata
= {
593 .init
= ip_rt_do_proc_init
,
594 .exit
= ip_rt_do_proc_exit
,
597 static int __init
ip_rt_proc_init(void)
599 return register_pernet_subsys(&ip_rt_proc_ops
);
603 static inline int ip_rt_proc_init(void)
607 #endif /* CONFIG_PROC_FS */
609 static inline void rt_free(struct rtable
*rt
)
611 call_rcu_bh(&rt
->dst
.rcu_head
, dst_rcu_free
);
614 static inline void rt_drop(struct rtable
*rt
)
617 call_rcu_bh(&rt
->dst
.rcu_head
, dst_rcu_free
);
620 static inline int rt_fast_clean(struct rtable
*rth
)
622 /* Kill broadcast/multicast entries very aggresively, if they
623 collide in hash table with more useful entries */
624 return (rth
->rt_flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) &&
625 rth
->fl
.iif
&& rth
->dst
.rt_next
;
628 static inline int rt_valuable(struct rtable
*rth
)
630 return (rth
->rt_flags
& (RTCF_REDIRECTED
| RTCF_NOTIFY
)) ||
634 static int rt_may_expire(struct rtable
*rth
, unsigned long tmo1
, unsigned long tmo2
)
639 if (atomic_read(&rth
->dst
.__refcnt
))
643 if (rth
->dst
.expires
&&
644 time_after_eq(jiffies
, rth
->dst
.expires
))
647 age
= jiffies
- rth
->dst
.lastuse
;
649 if ((age
<= tmo1
&& !rt_fast_clean(rth
)) ||
650 (age
<= tmo2
&& rt_valuable(rth
)))
656 /* Bits of score are:
658 * 30: not quite useless
659 * 29..0: usage counter
661 static inline u32
rt_score(struct rtable
*rt
)
663 u32 score
= jiffies
- rt
->dst
.lastuse
;
665 score
= ~score
& ~(3<<30);
671 !(rt
->rt_flags
& (RTCF_BROADCAST
|RTCF_MULTICAST
|RTCF_LOCAL
)))
677 static inline bool rt_caching(const struct net
*net
)
679 return net
->ipv4
.current_rt_cache_rebuild_count
<=
680 net
->ipv4
.sysctl_rt_cache_rebuild_count
;
683 static inline bool compare_hash_inputs(const struct flowi
*fl1
,
684 const struct flowi
*fl2
)
686 return ((((__force u32
)fl1
->nl_u
.ip4_u
.daddr
^ (__force u32
)fl2
->nl_u
.ip4_u
.daddr
) |
687 ((__force u32
)fl1
->nl_u
.ip4_u
.saddr
^ (__force u32
)fl2
->nl_u
.ip4_u
.saddr
) |
688 (fl1
->iif
^ fl2
->iif
)) == 0);
691 static inline int compare_keys(struct flowi
*fl1
, struct flowi
*fl2
)
693 return (((__force u32
)fl1
->nl_u
.ip4_u
.daddr
^ (__force u32
)fl2
->nl_u
.ip4_u
.daddr
) |
694 ((__force u32
)fl1
->nl_u
.ip4_u
.saddr
^ (__force u32
)fl2
->nl_u
.ip4_u
.saddr
) |
695 (fl1
->mark
^ fl2
->mark
) |
696 (*(u16
*)&fl1
->nl_u
.ip4_u
.tos
^ *(u16
*)&fl2
->nl_u
.ip4_u
.tos
) |
697 (fl1
->oif
^ fl2
->oif
) |
698 (fl1
->iif
^ fl2
->iif
)) == 0;
701 static inline int compare_netns(struct rtable
*rt1
, struct rtable
*rt2
)
703 return net_eq(dev_net(rt1
->dst
.dev
), dev_net(rt2
->dst
.dev
));
706 static inline int rt_is_expired(struct rtable
*rth
)
708 return rth
->rt_genid
!= rt_genid(dev_net(rth
->dst
.dev
));
712 * Perform a full scan of hash table and free all entries.
713 * Can be called by a softirq or a process.
714 * In the later case, we want to be reschedule if necessary
716 static void rt_do_flush(int process_context
)
719 struct rtable
*rth
, *next
;
720 struct rtable
* tail
;
722 for (i
= 0; i
<= rt_hash_mask
; i
++) {
723 if (process_context
&& need_resched())
725 rth
= rt_hash_table
[i
].chain
;
729 spin_lock_bh(rt_hash_lock_addr(i
));
732 struct rtable
** prev
, * p
;
734 rth
= rt_hash_table
[i
].chain
;
736 /* defer releasing the head of the list after spin_unlock */
737 for (tail
= rth
; tail
; tail
= tail
->dst
.rt_next
)
738 if (!rt_is_expired(tail
))
741 rt_hash_table
[i
].chain
= tail
;
743 /* call rt_free on entries after the tail requiring flush */
744 prev
= &rt_hash_table
[i
].chain
;
745 for (p
= *prev
; p
; p
= next
) {
746 next
= p
->dst
.rt_next
;
747 if (!rt_is_expired(p
)) {
748 prev
= &p
->dst
.rt_next
;
756 rth
= rt_hash_table
[i
].chain
;
757 rt_hash_table
[i
].chain
= NULL
;
760 spin_unlock_bh(rt_hash_lock_addr(i
));
762 for (; rth
!= tail
; rth
= next
) {
763 next
= rth
->dst
.rt_next
;
770 * While freeing expired entries, we compute average chain length
771 * and standard deviation, using fixed-point arithmetic.
772 * This to have an estimation of rt_chain_length_max
773 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
774 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
778 #define ONE (1UL << FRACT_BITS)
781 * Given a hash chain and an item in this hash chain,
782 * find if a previous entry has the same hash_inputs
783 * (but differs on tos, mark or oif)
784 * Returns 0 if an alias is found.
785 * Returns ONE if rth has no alias before itself.
787 static int has_noalias(const struct rtable
*head
, const struct rtable
*rth
)
789 const struct rtable
*aux
= head
;
792 if (compare_hash_inputs(&aux
->fl
, &rth
->fl
))
794 aux
= aux
->dst
.rt_next
;
799 static void rt_check_expire(void)
801 static unsigned int rover
;
802 unsigned int i
= rover
, goal
;
803 struct rtable
*rth
, **rthp
;
804 unsigned long samples
= 0;
805 unsigned long sum
= 0, sum2
= 0;
809 delta
= jiffies
- expires_ljiffies
;
810 expires_ljiffies
= jiffies
;
811 mult
= ((u64
)delta
) << rt_hash_log
;
812 if (ip_rt_gc_timeout
> 1)
813 do_div(mult
, ip_rt_gc_timeout
);
814 goal
= (unsigned int)mult
;
815 if (goal
> rt_hash_mask
)
816 goal
= rt_hash_mask
+ 1;
817 for (; goal
> 0; goal
--) {
818 unsigned long tmo
= ip_rt_gc_timeout
;
819 unsigned long length
;
821 i
= (i
+ 1) & rt_hash_mask
;
822 rthp
= &rt_hash_table
[i
].chain
;
832 spin_lock_bh(rt_hash_lock_addr(i
));
833 while ((rth
= *rthp
) != NULL
) {
834 prefetch(rth
->dst
.rt_next
);
835 if (rt_is_expired(rth
)) {
836 *rthp
= rth
->dst
.rt_next
;
840 if (rth
->dst
.expires
) {
841 /* Entry is expired even if it is in use */
842 if (time_before_eq(jiffies
, rth
->dst
.expires
)) {
845 rthp
= &rth
->dst
.rt_next
;
847 * We only count entries on
848 * a chain with equal hash inputs once
849 * so that entries for different QOS
850 * levels, and other non-hash input
851 * attributes don't unfairly skew
852 * the length computation
854 length
+= has_noalias(rt_hash_table
[i
].chain
, rth
);
857 } else if (!rt_may_expire(rth
, tmo
, ip_rt_gc_timeout
))
860 /* Cleanup aged off entries. */
861 *rthp
= rth
->dst
.rt_next
;
864 spin_unlock_bh(rt_hash_lock_addr(i
));
866 sum2
+= length
*length
;
869 unsigned long avg
= sum
/ samples
;
870 unsigned long sd
= int_sqrt(sum2
/ samples
- avg
*avg
);
871 rt_chain_length_max
= max_t(unsigned long,
873 (avg
+ 4*sd
) >> FRACT_BITS
);
879 * rt_worker_func() is run in process context.
880 * we call rt_check_expire() to scan part of the hash table
882 static void rt_worker_func(struct work_struct
*work
)
885 schedule_delayed_work(&expires_work
, ip_rt_gc_interval
);
889 * Pertubation of rt_genid by a small quantity [1..256]
890 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
891 * many times (2^24) without giving recent rt_genid.
892 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
894 static void rt_cache_invalidate(struct net
*net
)
896 unsigned char shuffle
;
898 get_random_bytes(&shuffle
, sizeof(shuffle
));
899 atomic_add(shuffle
+ 1U, &net
->ipv4
.rt_genid
);
903 * delay < 0 : invalidate cache (fast : entries will be deleted later)
904 * delay >= 0 : invalidate & flush cache (can be long)
906 void rt_cache_flush(struct net
*net
, int delay
)
908 rt_cache_invalidate(net
);
910 rt_do_flush(!in_softirq());
913 /* Flush previous cache invalidated entries from the cache */
914 void rt_cache_flush_batch(void)
916 rt_do_flush(!in_softirq());
919 static void rt_emergency_hash_rebuild(struct net
*net
)
922 printk(KERN_WARNING
"Route hash chain too long!\n");
923 rt_cache_invalidate(net
);
927 Short description of GC goals.
929 We want to build algorithm, which will keep routing cache
930 at some equilibrium point, when number of aged off entries
931 is kept approximately equal to newly generated ones.
933 Current expiration strength is variable "expire".
934 We try to adjust it dynamically, so that if networking
935 is idle expires is large enough to keep enough of warm entries,
936 and when load increases it reduces to limit cache size.
939 static int rt_garbage_collect(struct dst_ops
*ops
)
941 static unsigned long expire
= RT_GC_TIMEOUT
;
942 static unsigned long last_gc
;
944 static int equilibrium
;
945 struct rtable
*rth
, **rthp
;
946 unsigned long now
= jiffies
;
950 * Garbage collection is pretty expensive,
951 * do not make it too frequently.
954 RT_CACHE_STAT_INC(gc_total
);
956 if (now
- last_gc
< ip_rt_gc_min_interval
&&
957 atomic_read(&ipv4_dst_ops
.entries
) < ip_rt_max_size
) {
958 RT_CACHE_STAT_INC(gc_ignored
);
962 /* Calculate number of entries, which we want to expire now. */
963 goal
= atomic_read(&ipv4_dst_ops
.entries
) -
964 (ip_rt_gc_elasticity
<< rt_hash_log
);
966 if (equilibrium
< ipv4_dst_ops
.gc_thresh
)
967 equilibrium
= ipv4_dst_ops
.gc_thresh
;
968 goal
= atomic_read(&ipv4_dst_ops
.entries
) - equilibrium
;
970 equilibrium
+= min_t(unsigned int, goal
>> 1, rt_hash_mask
+ 1);
971 goal
= atomic_read(&ipv4_dst_ops
.entries
) - equilibrium
;
974 /* We are in dangerous area. Try to reduce cache really
977 goal
= max_t(unsigned int, goal
>> 1, rt_hash_mask
+ 1);
978 equilibrium
= atomic_read(&ipv4_dst_ops
.entries
) - goal
;
981 if (now
- last_gc
>= ip_rt_gc_min_interval
)
992 for (i
= rt_hash_mask
, k
= rover
; i
>= 0; i
--) {
993 unsigned long tmo
= expire
;
995 k
= (k
+ 1) & rt_hash_mask
;
996 rthp
= &rt_hash_table
[k
].chain
;
997 spin_lock_bh(rt_hash_lock_addr(k
));
998 while ((rth
= *rthp
) != NULL
) {
999 if (!rt_is_expired(rth
) &&
1000 !rt_may_expire(rth
, tmo
, expire
)) {
1002 rthp
= &rth
->dst
.rt_next
;
1005 *rthp
= rth
->dst
.rt_next
;
1009 spin_unlock_bh(rt_hash_lock_addr(k
));
1018 /* Goal is not achieved. We stop process if:
1020 - if expire reduced to zero. Otherwise, expire is halfed.
1021 - if table is not full.
1022 - if we are called from interrupt.
1023 - jiffies check is just fallback/debug loop breaker.
1024 We will not spin here for long time in any case.
1027 RT_CACHE_STAT_INC(gc_goal_miss
);
1033 #if RT_CACHE_DEBUG >= 2
1034 printk(KERN_DEBUG
"expire>> %u %d %d %d\n", expire
,
1035 atomic_read(&ipv4_dst_ops
.entries
), goal
, i
);
1038 if (atomic_read(&ipv4_dst_ops
.entries
) < ip_rt_max_size
)
1040 } while (!in_softirq() && time_before_eq(jiffies
, now
));
1042 if (atomic_read(&ipv4_dst_ops
.entries
) < ip_rt_max_size
)
1044 if (net_ratelimit())
1045 printk(KERN_WARNING
"dst cache overflow\n");
1046 RT_CACHE_STAT_INC(gc_dst_overflow
);
1050 expire
+= ip_rt_gc_min_interval
;
1051 if (expire
> ip_rt_gc_timeout
||
1052 atomic_read(&ipv4_dst_ops
.entries
) < ipv4_dst_ops
.gc_thresh
)
1053 expire
= ip_rt_gc_timeout
;
1054 #if RT_CACHE_DEBUG >= 2
1055 printk(KERN_DEBUG
"expire++ %u %d %d %d\n", expire
,
1056 atomic_read(&ipv4_dst_ops
.entries
), goal
, rover
);
1062 * Returns number of entries in a hash chain that have different hash_inputs
1064 static int slow_chain_length(const struct rtable
*head
)
1067 const struct rtable
*rth
= head
;
1070 length
+= has_noalias(head
, rth
);
1071 rth
= rth
->dst
.rt_next
;
1073 return length
>> FRACT_BITS
;
1076 static int rt_intern_hash(unsigned hash
, struct rtable
*rt
,
1077 struct rtable
**rp
, struct sk_buff
*skb
, int ifindex
)
1079 struct rtable
*rth
, **rthp
;
1081 struct rtable
*cand
, **candp
;
1084 int attempts
= !in_softirq();
1088 min_score
= ~(u32
)0;
1093 if (!rt_caching(dev_net(rt
->dst
.dev
))) {
1095 * If we're not caching, just tell the caller we
1096 * were successful and don't touch the route. The
1097 * caller hold the sole reference to the cache entry, and
1098 * it will be released when the caller is done with it.
1099 * If we drop it here, the callers have no way to resolve routes
1100 * when we're not caching. Instead, just point *rp at rt, so
1101 * the caller gets a single use out of the route
1102 * Note that we do rt_free on this new route entry, so that
1103 * once its refcount hits zero, we are still able to reap it
1105 * Note also the rt_free uses call_rcu. We don't actually
1106 * need rcu protection here, this is just our path to get
1107 * on the route gc list.
1110 if (rt
->rt_type
== RTN_UNICAST
|| rt
->fl
.iif
== 0) {
1111 int err
= arp_bind_neighbour(&rt
->dst
);
1113 if (net_ratelimit())
1115 "Neighbour table failure & not caching routes.\n");
1125 rthp
= &rt_hash_table
[hash
].chain
;
1127 spin_lock_bh(rt_hash_lock_addr(hash
));
1128 while ((rth
= *rthp
) != NULL
) {
1129 if (rt_is_expired(rth
)) {
1130 *rthp
= rth
->dst
.rt_next
;
1134 if (compare_keys(&rth
->fl
, &rt
->fl
) && compare_netns(rth
, rt
)) {
1136 *rthp
= rth
->dst
.rt_next
;
1138 * Since lookup is lockfree, the deletion
1139 * must be visible to another weakly ordered CPU before
1140 * the insertion at the start of the hash chain.
1142 rcu_assign_pointer(rth
->dst
.rt_next
,
1143 rt_hash_table
[hash
].chain
);
1145 * Since lookup is lockfree, the update writes
1146 * must be ordered for consistency on SMP.
1148 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rth
);
1150 dst_use(&rth
->dst
, now
);
1151 spin_unlock_bh(rt_hash_lock_addr(hash
));
1157 skb_dst_set(skb
, &rth
->dst
);
1161 if (!atomic_read(&rth
->dst
.__refcnt
)) {
1162 u32 score
= rt_score(rth
);
1164 if (score
<= min_score
) {
1173 rthp
= &rth
->dst
.rt_next
;
1177 /* ip_rt_gc_elasticity used to be average length of chain
1178 * length, when exceeded gc becomes really aggressive.
1180 * The second limit is less certain. At the moment it allows
1181 * only 2 entries per bucket. We will see.
1183 if (chain_length
> ip_rt_gc_elasticity
) {
1184 *candp
= cand
->dst
.rt_next
;
1188 if (chain_length
> rt_chain_length_max
&&
1189 slow_chain_length(rt_hash_table
[hash
].chain
) > rt_chain_length_max
) {
1190 struct net
*net
= dev_net(rt
->dst
.dev
);
1191 int num
= ++net
->ipv4
.current_rt_cache_rebuild_count
;
1192 if (!rt_caching(net
)) {
1193 printk(KERN_WARNING
"%s: %d rebuilds is over limit, route caching disabled\n",
1194 rt
->dst
.dev
->name
, num
);
1196 rt_emergency_hash_rebuild(net
);
1197 spin_unlock_bh(rt_hash_lock_addr(hash
));
1199 hash
= rt_hash(rt
->fl
.fl4_dst
, rt
->fl
.fl4_src
,
1200 ifindex
, rt_genid(net
));
1205 /* Try to bind route to arp only if it is output
1206 route or unicast forwarding path.
1208 if (rt
->rt_type
== RTN_UNICAST
|| rt
->fl
.iif
== 0) {
1209 int err
= arp_bind_neighbour(&rt
->dst
);
1211 spin_unlock_bh(rt_hash_lock_addr(hash
));
1213 if (err
!= -ENOBUFS
) {
1218 /* Neighbour tables are full and nothing
1219 can be released. Try to shrink route cache,
1220 it is most likely it holds some neighbour records.
1222 if (attempts
-- > 0) {
1223 int saved_elasticity
= ip_rt_gc_elasticity
;
1224 int saved_int
= ip_rt_gc_min_interval
;
1225 ip_rt_gc_elasticity
= 1;
1226 ip_rt_gc_min_interval
= 0;
1227 rt_garbage_collect(&ipv4_dst_ops
);
1228 ip_rt_gc_min_interval
= saved_int
;
1229 ip_rt_gc_elasticity
= saved_elasticity
;
1233 if (net_ratelimit())
1234 printk(KERN_WARNING
"Neighbour table overflow.\n");
1240 rt
->dst
.rt_next
= rt_hash_table
[hash
].chain
;
1242 #if RT_CACHE_DEBUG >= 2
1243 if (rt
->dst
.rt_next
) {
1245 printk(KERN_DEBUG
"rt_cache @%02x: %pI4",
1247 for (trt
= rt
->dst
.rt_next
; trt
; trt
= trt
->dst
.rt_next
)
1248 printk(" . %pI4", &trt
->rt_dst
);
1253 * Since lookup is lockfree, we must make sure
1254 * previous writes to rt are comitted to memory
1255 * before making rt visible to other CPUS.
1257 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rt
);
1259 spin_unlock_bh(rt_hash_lock_addr(hash
));
1265 skb_dst_set(skb
, &rt
->dst
);
1269 void rt_bind_peer(struct rtable
*rt
, int create
)
1271 struct inet_peer
*peer
;
1273 peer
= inet_getpeer(rt
->rt_dst
, create
);
1275 if (peer
&& cmpxchg(&rt
->peer
, NULL
, peer
) != NULL
)
1280 * Peer allocation may fail only in serious out-of-memory conditions. However
1281 * we still can generate some output.
1282 * Random ID selection looks a bit dangerous because we have no chances to
1283 * select ID being unique in a reasonable period of time.
1284 * But broken packet identifier may be better than no packet at all.
1286 static void ip_select_fb_ident(struct iphdr
*iph
)
1288 static DEFINE_SPINLOCK(ip_fb_id_lock
);
1289 static u32 ip_fallback_id
;
1292 spin_lock_bh(&ip_fb_id_lock
);
1293 salt
= secure_ip_id((__force __be32
)ip_fallback_id
^ iph
->daddr
);
1294 iph
->id
= htons(salt
& 0xFFFF);
1295 ip_fallback_id
= salt
;
1296 spin_unlock_bh(&ip_fb_id_lock
);
1299 void __ip_select_ident(struct iphdr
*iph
, struct dst_entry
*dst
, int more
)
1301 struct rtable
*rt
= (struct rtable
*) dst
;
1304 if (rt
->peer
== NULL
)
1305 rt_bind_peer(rt
, 1);
1307 /* If peer is attached to destination, it is never detached,
1308 so that we need not to grab a lock to dereference it.
1311 iph
->id
= htons(inet_getid(rt
->peer
, more
));
1315 printk(KERN_DEBUG
"rt_bind_peer(0) @%p\n",
1316 __builtin_return_address(0));
1318 ip_select_fb_ident(iph
);
1320 EXPORT_SYMBOL(__ip_select_ident
);
1322 static void rt_del(unsigned hash
, struct rtable
*rt
)
1324 struct rtable
**rthp
, *aux
;
1326 rthp
= &rt_hash_table
[hash
].chain
;
1327 spin_lock_bh(rt_hash_lock_addr(hash
));
1329 while ((aux
= *rthp
) != NULL
) {
1330 if (aux
== rt
|| rt_is_expired(aux
)) {
1331 *rthp
= aux
->dst
.rt_next
;
1335 rthp
= &aux
->dst
.rt_next
;
1337 spin_unlock_bh(rt_hash_lock_addr(hash
));
1340 /* called in rcu_read_lock() section */
1341 void ip_rt_redirect(__be32 old_gw
, __be32 daddr
, __be32 new_gw
,
1342 __be32 saddr
, struct net_device
*dev
)
1345 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
1346 struct rtable
*rth
, **rthp
;
1347 __be32 skeys
[2] = { saddr
, 0 };
1348 int ikeys
[2] = { dev
->ifindex
, 0 };
1349 struct netevent_redirect netevent
;
1356 if (new_gw
== old_gw
|| !IN_DEV_RX_REDIRECTS(in_dev
) ||
1357 ipv4_is_multicast(new_gw
) || ipv4_is_lbcast(new_gw
) ||
1358 ipv4_is_zeronet(new_gw
))
1359 goto reject_redirect
;
1361 if (!rt_caching(net
))
1362 goto reject_redirect
;
1364 if (!IN_DEV_SHARED_MEDIA(in_dev
)) {
1365 if (!inet_addr_onlink(in_dev
, new_gw
, old_gw
))
1366 goto reject_redirect
;
1367 if (IN_DEV_SEC_REDIRECTS(in_dev
) && ip_fib_check_default(new_gw
, dev
))
1368 goto reject_redirect
;
1370 if (inet_addr_type(net
, new_gw
) != RTN_UNICAST
)
1371 goto reject_redirect
;
1374 for (i
= 0; i
< 2; i
++) {
1375 for (k
= 0; k
< 2; k
++) {
1376 unsigned hash
= rt_hash(daddr
, skeys
[i
], ikeys
[k
],
1379 rthp
=&rt_hash_table
[hash
].chain
;
1381 while ((rth
= rcu_dereference(*rthp
)) != NULL
) {
1384 if (rth
->fl
.fl4_dst
!= daddr
||
1385 rth
->fl
.fl4_src
!= skeys
[i
] ||
1386 rth
->fl
.oif
!= ikeys
[k
] ||
1388 rt_is_expired(rth
) ||
1389 !net_eq(dev_net(rth
->dst
.dev
), net
)) {
1390 rthp
= &rth
->dst
.rt_next
;
1394 if (rth
->rt_dst
!= daddr
||
1395 rth
->rt_src
!= saddr
||
1397 rth
->rt_gateway
!= old_gw
||
1398 rth
->dst
.dev
!= dev
)
1401 dst_hold(&rth
->dst
);
1403 rt
= dst_alloc(&ipv4_dst_ops
);
1409 /* Copy all the information. */
1412 atomic_set(&rt
->dst
.__refcnt
, 1);
1413 rt
->dst
.child
= NULL
;
1415 dev_hold(rt
->dst
.dev
);
1417 in_dev_hold(rt
->idev
);
1418 rt
->dst
.obsolete
= -1;
1419 rt
->dst
.lastuse
= jiffies
;
1420 rt
->dst
.path
= &rt
->dst
;
1421 rt
->dst
.neighbour
= NULL
;
1424 rt
->dst
.xfrm
= NULL
;
1426 rt
->rt_genid
= rt_genid(net
);
1427 rt
->rt_flags
|= RTCF_REDIRECTED
;
1429 /* Gateway is different ... */
1430 rt
->rt_gateway
= new_gw
;
1432 /* Redirect received -> path was valid */
1433 dst_confirm(&rth
->dst
);
1436 atomic_inc(&rt
->peer
->refcnt
);
1438 if (arp_bind_neighbour(&rt
->dst
) ||
1439 !(rt
->dst
.neighbour
->nud_state
&
1441 if (rt
->dst
.neighbour
)
1442 neigh_event_send(rt
->dst
.neighbour
, NULL
);
1448 netevent
.old
= &rth
->dst
;
1449 netevent
.new = &rt
->dst
;
1450 call_netevent_notifiers(NETEVENT_REDIRECT
,
1454 if (!rt_intern_hash(hash
, rt
, &rt
, NULL
, rt
->fl
.oif
))
1465 #ifdef CONFIG_IP_ROUTE_VERBOSE
1466 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit())
1467 printk(KERN_INFO
"Redirect from %pI4 on %s about %pI4 ignored.\n"
1468 " Advised path = %pI4 -> %pI4\n",
1469 &old_gw
, dev
->name
, &new_gw
,
1475 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
)
1477 struct rtable
*rt
= (struct rtable
*)dst
;
1478 struct dst_entry
*ret
= dst
;
1481 if (dst
->obsolete
> 0) {
1484 } else if ((rt
->rt_flags
& RTCF_REDIRECTED
) ||
1486 time_after_eq(jiffies
, rt
->dst
.expires
))) {
1487 unsigned hash
= rt_hash(rt
->fl
.fl4_dst
, rt
->fl
.fl4_src
,
1489 rt_genid(dev_net(dst
->dev
)));
1490 #if RT_CACHE_DEBUG >= 1
1491 printk(KERN_DEBUG
"ipv4_negative_advice: redirect to %pI4/%02x dropped\n",
1492 &rt
->rt_dst
, rt
->fl
.fl4_tos
);
1503 * 1. The first ip_rt_redirect_number redirects are sent
1504 * with exponential backoff, then we stop sending them at all,
1505 * assuming that the host ignores our redirects.
1506 * 2. If we did not see packets requiring redirects
1507 * during ip_rt_redirect_silence, we assume that the host
1508 * forgot redirected route and start to send redirects again.
1510 * This algorithm is much cheaper and more intelligent than dumb load limiting
1513 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1514 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1517 void ip_rt_send_redirect(struct sk_buff
*skb
)
1519 struct rtable
*rt
= skb_rtable(skb
);
1520 struct in_device
*in_dev
;
1524 in_dev
= __in_dev_get_rcu(rt
->dst
.dev
);
1525 if (!in_dev
|| !IN_DEV_TX_REDIRECTS(in_dev
)) {
1529 log_martians
= IN_DEV_LOG_MARTIANS(in_dev
);
1532 /* No redirected packets during ip_rt_redirect_silence;
1533 * reset the algorithm.
1535 if (time_after(jiffies
, rt
->dst
.rate_last
+ ip_rt_redirect_silence
))
1536 rt
->dst
.rate_tokens
= 0;
1538 /* Too many ignored redirects; do not send anything
1539 * set dst.rate_last to the last seen redirected packet.
1541 if (rt
->dst
.rate_tokens
>= ip_rt_redirect_number
) {
1542 rt
->dst
.rate_last
= jiffies
;
1546 /* Check for load limit; set rate_last to the latest sent
1549 if (rt
->dst
.rate_tokens
== 0 ||
1551 (rt
->dst
.rate_last
+
1552 (ip_rt_redirect_load
<< rt
->dst
.rate_tokens
)))) {
1553 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, rt
->rt_gateway
);
1554 rt
->dst
.rate_last
= jiffies
;
1555 ++rt
->dst
.rate_tokens
;
1556 #ifdef CONFIG_IP_ROUTE_VERBOSE
1558 rt
->dst
.rate_tokens
== ip_rt_redirect_number
&&
1560 printk(KERN_WARNING
"host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1561 &rt
->rt_src
, rt
->rt_iif
,
1562 &rt
->rt_dst
, &rt
->rt_gateway
);
1567 static int ip_error(struct sk_buff
*skb
)
1569 struct rtable
*rt
= skb_rtable(skb
);
1573 switch (rt
->dst
.error
) {
1578 code
= ICMP_HOST_UNREACH
;
1581 code
= ICMP_NET_UNREACH
;
1582 IP_INC_STATS_BH(dev_net(rt
->dst
.dev
),
1583 IPSTATS_MIB_INNOROUTES
);
1586 code
= ICMP_PKT_FILTERED
;
1591 rt
->dst
.rate_tokens
+= now
- rt
->dst
.rate_last
;
1592 if (rt
->dst
.rate_tokens
> ip_rt_error_burst
)
1593 rt
->dst
.rate_tokens
= ip_rt_error_burst
;
1594 rt
->dst
.rate_last
= now
;
1595 if (rt
->dst
.rate_tokens
>= ip_rt_error_cost
) {
1596 rt
->dst
.rate_tokens
-= ip_rt_error_cost
;
1597 icmp_send(skb
, ICMP_DEST_UNREACH
, code
, 0);
1600 out
: kfree_skb(skb
);
1605 * The last two values are not from the RFC but
1606 * are needed for AMPRnet AX.25 paths.
1609 static const unsigned short mtu_plateau
[] =
1610 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1612 static inline unsigned short guess_mtu(unsigned short old_mtu
)
1616 for (i
= 0; i
< ARRAY_SIZE(mtu_plateau
); i
++)
1617 if (old_mtu
> mtu_plateau
[i
])
1618 return mtu_plateau
[i
];
1622 unsigned short ip_rt_frag_needed(struct net
*net
, struct iphdr
*iph
,
1623 unsigned short new_mtu
,
1624 struct net_device
*dev
)
1627 unsigned short old_mtu
= ntohs(iph
->tot_len
);
1629 int ikeys
[2] = { dev
->ifindex
, 0 };
1630 __be32 skeys
[2] = { iph
->saddr
, 0, };
1631 __be32 daddr
= iph
->daddr
;
1632 unsigned short est_mtu
= 0;
1634 for (k
= 0; k
< 2; k
++) {
1635 for (i
= 0; i
< 2; i
++) {
1636 unsigned hash
= rt_hash(daddr
, skeys
[i
], ikeys
[k
],
1640 for (rth
= rcu_dereference(rt_hash_table
[hash
].chain
); rth
;
1641 rth
= rcu_dereference(rth
->dst
.rt_next
)) {
1642 unsigned short mtu
= new_mtu
;
1644 if (rth
->fl
.fl4_dst
!= daddr
||
1645 rth
->fl
.fl4_src
!= skeys
[i
] ||
1646 rth
->rt_dst
!= daddr
||
1647 rth
->rt_src
!= iph
->saddr
||
1648 rth
->fl
.oif
!= ikeys
[k
] ||
1650 dst_metric_locked(&rth
->dst
, RTAX_MTU
) ||
1651 !net_eq(dev_net(rth
->dst
.dev
), net
) ||
1655 if (new_mtu
< 68 || new_mtu
>= old_mtu
) {
1657 /* BSD 4.2 compatibility hack :-( */
1659 old_mtu
>= dst_mtu(&rth
->dst
) &&
1660 old_mtu
>= 68 + (iph
->ihl
<< 2))
1661 old_mtu
-= iph
->ihl
<< 2;
1663 mtu
= guess_mtu(old_mtu
);
1665 if (mtu
<= dst_mtu(&rth
->dst
)) {
1666 if (mtu
< dst_mtu(&rth
->dst
)) {
1667 dst_confirm(&rth
->dst
);
1668 if (mtu
< ip_rt_min_pmtu
) {
1669 mtu
= ip_rt_min_pmtu
;
1670 rth
->dst
.metrics
[RTAX_LOCK
-1] |=
1673 rth
->dst
.metrics
[RTAX_MTU
-1] = mtu
;
1674 dst_set_expires(&rth
->dst
,
1683 return est_mtu
? : new_mtu
;
1686 static void ip_rt_update_pmtu(struct dst_entry
*dst
, u32 mtu
)
1688 if (dst_mtu(dst
) > mtu
&& mtu
>= 68 &&
1689 !(dst_metric_locked(dst
, RTAX_MTU
))) {
1690 if (mtu
< ip_rt_min_pmtu
) {
1691 mtu
= ip_rt_min_pmtu
;
1692 dst
->metrics
[RTAX_LOCK
-1] |= (1 << RTAX_MTU
);
1694 dst
->metrics
[RTAX_MTU
-1] = mtu
;
1695 dst_set_expires(dst
, ip_rt_mtu_expires
);
1696 call_netevent_notifiers(NETEVENT_PMTU_UPDATE
, dst
);
1700 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
)
1702 if (rt_is_expired((struct rtable
*)dst
))
1707 static void ipv4_dst_destroy(struct dst_entry
*dst
)
1709 struct rtable
*rt
= (struct rtable
*) dst
;
1710 struct inet_peer
*peer
= rt
->peer
;
1711 struct in_device
*idev
= rt
->idev
;
1724 static void ipv4_dst_ifdown(struct dst_entry
*dst
, struct net_device
*dev
,
1727 struct rtable
*rt
= (struct rtable
*) dst
;
1728 struct in_device
*idev
= rt
->idev
;
1729 if (dev
!= dev_net(dev
)->loopback_dev
&& idev
&& idev
->dev
== dev
) {
1730 struct in_device
*loopback_idev
=
1731 in_dev_get(dev_net(dev
)->loopback_dev
);
1732 if (loopback_idev
) {
1733 rt
->idev
= loopback_idev
;
1739 static void ipv4_link_failure(struct sk_buff
*skb
)
1743 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_HOST_UNREACH
, 0);
1745 rt
= skb_rtable(skb
);
1747 dst_set_expires(&rt
->dst
, 0);
1750 static int ip_rt_bug(struct sk_buff
*skb
)
1752 printk(KERN_DEBUG
"ip_rt_bug: %pI4 -> %pI4, %s\n",
1753 &ip_hdr(skb
)->saddr
, &ip_hdr(skb
)->daddr
,
1754 skb
->dev
? skb
->dev
->name
: "?");
1760 We do not cache source address of outgoing interface,
1761 because it is used only by IP RR, TS and SRR options,
1762 so that it out of fast path.
1764 BTW remember: "addr" is allowed to be not aligned
1768 void ip_rt_get_source(u8
*addr
, struct rtable
*rt
)
1771 struct fib_result res
;
1773 if (rt
->fl
.iif
== 0)
1775 else if (fib_lookup(dev_net(rt
->dst
.dev
), &rt
->fl
, &res
) == 0) {
1776 src
= FIB_RES_PREFSRC(res
);
1779 src
= inet_select_addr(rt
->dst
.dev
, rt
->rt_gateway
,
1781 memcpy(addr
, &src
, 4);
1784 #ifdef CONFIG_NET_CLS_ROUTE
1785 static void set_class_tag(struct rtable
*rt
, u32 tag
)
1787 if (!(rt
->dst
.tclassid
& 0xFFFF))
1788 rt
->dst
.tclassid
|= tag
& 0xFFFF;
1789 if (!(rt
->dst
.tclassid
& 0xFFFF0000))
1790 rt
->dst
.tclassid
|= tag
& 0xFFFF0000;
1794 static void rt_set_nexthop(struct rtable
*rt
, struct fib_result
*res
, u32 itag
)
1796 struct fib_info
*fi
= res
->fi
;
1799 if (FIB_RES_GW(*res
) &&
1800 FIB_RES_NH(*res
).nh_scope
== RT_SCOPE_LINK
)
1801 rt
->rt_gateway
= FIB_RES_GW(*res
);
1802 memcpy(rt
->dst
.metrics
, fi
->fib_metrics
,
1803 sizeof(rt
->dst
.metrics
));
1804 if (fi
->fib_mtu
== 0) {
1805 rt
->dst
.metrics
[RTAX_MTU
-1] = rt
->dst
.dev
->mtu
;
1806 if (dst_metric_locked(&rt
->dst
, RTAX_MTU
) &&
1807 rt
->rt_gateway
!= rt
->rt_dst
&&
1808 rt
->dst
.dev
->mtu
> 576)
1809 rt
->dst
.metrics
[RTAX_MTU
-1] = 576;
1811 #ifdef CONFIG_NET_CLS_ROUTE
1812 rt
->dst
.tclassid
= FIB_RES_NH(*res
).nh_tclassid
;
1815 rt
->dst
.metrics
[RTAX_MTU
-1]= rt
->dst
.dev
->mtu
;
1817 if (dst_metric(&rt
->dst
, RTAX_HOPLIMIT
) == 0)
1818 rt
->dst
.metrics
[RTAX_HOPLIMIT
-1] = sysctl_ip_default_ttl
;
1819 if (dst_mtu(&rt
->dst
) > IP_MAX_MTU
)
1820 rt
->dst
.metrics
[RTAX_MTU
-1] = IP_MAX_MTU
;
1821 if (dst_metric(&rt
->dst
, RTAX_ADVMSS
) == 0)
1822 rt
->dst
.metrics
[RTAX_ADVMSS
-1] = max_t(unsigned int, rt
->dst
.dev
->mtu
- 40,
1824 if (dst_metric(&rt
->dst
, RTAX_ADVMSS
) > 65535 - 40)
1825 rt
->dst
.metrics
[RTAX_ADVMSS
-1] = 65535 - 40;
1827 #ifdef CONFIG_NET_CLS_ROUTE
1828 #ifdef CONFIG_IP_MULTIPLE_TABLES
1829 set_class_tag(rt
, fib_rules_tclass(res
));
1831 set_class_tag(rt
, itag
);
1833 rt
->rt_type
= res
->type
;
1836 /* called in rcu_read_lock() section */
1837 static int ip_route_input_mc(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
1838 u8 tos
, struct net_device
*dev
, int our
)
1843 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
1847 /* Primary sanity checks. */
1852 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
) ||
1853 ipv4_is_loopback(saddr
) || skb
->protocol
!= htons(ETH_P_IP
))
1856 if (ipv4_is_zeronet(saddr
)) {
1857 if (!ipv4_is_local_multicast(daddr
))
1859 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_LINK
);
1861 err
= fib_validate_source(saddr
, 0, tos
, 0, dev
, &spec_dst
,
1866 rth
= dst_alloc(&ipv4_dst_ops
);
1870 rth
->dst
.output
= ip_rt_bug
;
1871 rth
->dst
.obsolete
= -1;
1873 atomic_set(&rth
->dst
.__refcnt
, 1);
1874 rth
->dst
.flags
= DST_HOST
;
1875 if (IN_DEV_CONF_GET(in_dev
, NOPOLICY
))
1876 rth
->dst
.flags
|= DST_NOPOLICY
;
1877 rth
->fl
.fl4_dst
= daddr
;
1878 rth
->rt_dst
= daddr
;
1879 rth
->fl
.fl4_tos
= tos
;
1880 rth
->fl
.mark
= skb
->mark
;
1881 rth
->fl
.fl4_src
= saddr
;
1882 rth
->rt_src
= saddr
;
1883 #ifdef CONFIG_NET_CLS_ROUTE
1884 rth
->dst
.tclassid
= itag
;
1887 rth
->fl
.iif
= dev
->ifindex
;
1888 rth
->dst
.dev
= init_net
.loopback_dev
;
1889 dev_hold(rth
->dst
.dev
);
1890 rth
->idev
= in_dev_get(rth
->dst
.dev
);
1892 rth
->rt_gateway
= daddr
;
1893 rth
->rt_spec_dst
= spec_dst
;
1894 rth
->rt_genid
= rt_genid(dev_net(dev
));
1895 rth
->rt_flags
= RTCF_MULTICAST
;
1896 rth
->rt_type
= RTN_MULTICAST
;
1898 rth
->dst
.input
= ip_local_deliver
;
1899 rth
->rt_flags
|= RTCF_LOCAL
;
1902 #ifdef CONFIG_IP_MROUTE
1903 if (!ipv4_is_local_multicast(daddr
) && IN_DEV_MFORWARD(in_dev
))
1904 rth
->dst
.input
= ip_mr_input
;
1906 RT_CACHE_STAT_INC(in_slow_mc
);
1908 hash
= rt_hash(daddr
, saddr
, dev
->ifindex
, rt_genid(dev_net(dev
)));
1909 return rt_intern_hash(hash
, rth
, NULL
, skb
, dev
->ifindex
);
1920 static void ip_handle_martian_source(struct net_device
*dev
,
1921 struct in_device
*in_dev
,
1922 struct sk_buff
*skb
,
1926 RT_CACHE_STAT_INC(in_martian_src
);
1927 #ifdef CONFIG_IP_ROUTE_VERBOSE
1928 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit()) {
1930 * RFC1812 recommendation, if source is martian,
1931 * the only hint is MAC header.
1933 printk(KERN_WARNING
"martian source %pI4 from %pI4, on dev %s\n",
1934 &daddr
, &saddr
, dev
->name
);
1935 if (dev
->hard_header_len
&& skb_mac_header_was_set(skb
)) {
1937 const unsigned char *p
= skb_mac_header(skb
);
1938 printk(KERN_WARNING
"ll header: ");
1939 for (i
= 0; i
< dev
->hard_header_len
; i
++, p
++) {
1941 if (i
< (dev
->hard_header_len
- 1))
1950 /* called in rcu_read_lock() section */
1951 static int __mkroute_input(struct sk_buff
*skb
,
1952 struct fib_result
*res
,
1953 struct in_device
*in_dev
,
1954 __be32 daddr
, __be32 saddr
, u32 tos
,
1955 struct rtable
**result
)
1959 struct in_device
*out_dev
;
1960 unsigned int flags
= 0;
1964 /* get a working reference to the output device */
1965 out_dev
= __in_dev_get_rcu(FIB_RES_DEV(*res
));
1966 if (out_dev
== NULL
) {
1967 if (net_ratelimit())
1968 printk(KERN_CRIT
"Bug in ip_route_input" \
1969 "_slow(). Please, report\n");
1974 err
= fib_validate_source(saddr
, daddr
, tos
, FIB_RES_OIF(*res
),
1975 in_dev
->dev
, &spec_dst
, &itag
, skb
->mark
);
1977 ip_handle_martian_source(in_dev
->dev
, in_dev
, skb
, daddr
,
1984 flags
|= RTCF_DIRECTSRC
;
1986 if (out_dev
== in_dev
&& err
&&
1987 (IN_DEV_SHARED_MEDIA(out_dev
) ||
1988 inet_addr_onlink(out_dev
, saddr
, FIB_RES_GW(*res
))))
1989 flags
|= RTCF_DOREDIRECT
;
1991 if (skb
->protocol
!= htons(ETH_P_IP
)) {
1992 /* Not IP (i.e. ARP). Do not create route, if it is
1993 * invalid for proxy arp. DNAT routes are always valid.
1995 * Proxy arp feature have been extended to allow, ARP
1996 * replies back to the same interface, to support
1997 * Private VLAN switch technologies. See arp.c.
1999 if (out_dev
== in_dev
&&
2000 IN_DEV_PROXY_ARP_PVLAN(in_dev
) == 0) {
2007 rth
= dst_alloc(&ipv4_dst_ops
);
2013 atomic_set(&rth
->dst
.__refcnt
, 1);
2014 rth
->dst
.flags
= DST_HOST
;
2015 if (IN_DEV_CONF_GET(in_dev
, NOPOLICY
))
2016 rth
->dst
.flags
|= DST_NOPOLICY
;
2017 if (IN_DEV_CONF_GET(out_dev
, NOXFRM
))
2018 rth
->dst
.flags
|= DST_NOXFRM
;
2019 rth
->fl
.fl4_dst
= daddr
;
2020 rth
->rt_dst
= daddr
;
2021 rth
->fl
.fl4_tos
= tos
;
2022 rth
->fl
.mark
= skb
->mark
;
2023 rth
->fl
.fl4_src
= saddr
;
2024 rth
->rt_src
= saddr
;
2025 rth
->rt_gateway
= daddr
;
2027 rth
->fl
.iif
= in_dev
->dev
->ifindex
;
2028 rth
->dst
.dev
= (out_dev
)->dev
;
2029 dev_hold(rth
->dst
.dev
);
2030 rth
->idev
= in_dev_get(rth
->dst
.dev
);
2032 rth
->rt_spec_dst
= spec_dst
;
2034 rth
->dst
.obsolete
= -1;
2035 rth
->dst
.input
= ip_forward
;
2036 rth
->dst
.output
= ip_output
;
2037 rth
->rt_genid
= rt_genid(dev_net(rth
->dst
.dev
));
2039 rt_set_nexthop(rth
, res
, itag
);
2041 rth
->rt_flags
= flags
;
2049 static int ip_mkroute_input(struct sk_buff
*skb
,
2050 struct fib_result
*res
,
2051 const struct flowi
*fl
,
2052 struct in_device
*in_dev
,
2053 __be32 daddr
, __be32 saddr
, u32 tos
)
2055 struct rtable
* rth
= NULL
;
2059 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2060 if (res
->fi
&& res
->fi
->fib_nhs
> 1 && fl
->oif
== 0)
2061 fib_select_multipath(fl
, res
);
2064 /* create a routing cache entry */
2065 err
= __mkroute_input(skb
, res
, in_dev
, daddr
, saddr
, tos
, &rth
);
2069 /* put it into the cache */
2070 hash
= rt_hash(daddr
, saddr
, fl
->iif
,
2071 rt_genid(dev_net(rth
->dst
.dev
)));
2072 return rt_intern_hash(hash
, rth
, NULL
, skb
, fl
->iif
);
2076 * NOTE. We drop all the packets that has local source
2077 * addresses, because every properly looped back packet
2078 * must have correct destination already attached by output routine.
2080 * Such approach solves two big problems:
2081 * 1. Not simplex devices are handled properly.
2082 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2085 static int ip_route_input_slow(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2086 u8 tos
, struct net_device
*dev
)
2088 struct fib_result res
;
2089 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
2090 struct flowi fl
= { .nl_u
= { .ip4_u
=
2094 .scope
= RT_SCOPE_UNIVERSE
,
2097 .iif
= dev
->ifindex
};
2100 struct rtable
* rth
;
2105 struct net
* net
= dev_net(dev
);
2107 /* IP on this device is disabled. */
2112 /* Check for the most weird martians, which can be not detected
2116 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
) ||
2117 ipv4_is_loopback(saddr
))
2118 goto martian_source
;
2120 if (daddr
== htonl(0xFFFFFFFF) || (saddr
== 0 && daddr
== 0))
2123 /* Accept zero addresses only to limited broadcast;
2124 * I even do not know to fix it or not. Waiting for complains :-)
2126 if (ipv4_is_zeronet(saddr
))
2127 goto martian_source
;
2129 if (ipv4_is_lbcast(daddr
) || ipv4_is_zeronet(daddr
) ||
2130 ipv4_is_loopback(daddr
))
2131 goto martian_destination
;
2134 * Now we are ready to route packet.
2136 if ((err
= fib_lookup(net
, &fl
, &res
)) != 0) {
2137 if (!IN_DEV_FORWARD(in_dev
))
2143 RT_CACHE_STAT_INC(in_slow_tot
);
2145 if (res
.type
== RTN_BROADCAST
)
2148 if (res
.type
== RTN_LOCAL
) {
2149 err
= fib_validate_source(saddr
, daddr
, tos
,
2150 net
->loopback_dev
->ifindex
,
2151 dev
, &spec_dst
, &itag
, skb
->mark
);
2153 goto martian_source_keep_err
;
2155 flags
|= RTCF_DIRECTSRC
;
2160 if (!IN_DEV_FORWARD(in_dev
))
2162 if (res
.type
!= RTN_UNICAST
)
2163 goto martian_destination
;
2165 err
= ip_mkroute_input(skb
, &res
, &fl
, in_dev
, daddr
, saddr
, tos
);
2172 if (skb
->protocol
!= htons(ETH_P_IP
))
2175 if (ipv4_is_zeronet(saddr
))
2176 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_LINK
);
2178 err
= fib_validate_source(saddr
, 0, tos
, 0, dev
, &spec_dst
,
2181 goto martian_source_keep_err
;
2183 flags
|= RTCF_DIRECTSRC
;
2185 flags
|= RTCF_BROADCAST
;
2186 res
.type
= RTN_BROADCAST
;
2187 RT_CACHE_STAT_INC(in_brd
);
2190 rth
= dst_alloc(&ipv4_dst_ops
);
2194 rth
->dst
.output
= ip_rt_bug
;
2195 rth
->dst
.obsolete
= -1;
2196 rth
->rt_genid
= rt_genid(net
);
2198 atomic_set(&rth
->dst
.__refcnt
, 1);
2199 rth
->dst
.flags
= DST_HOST
;
2200 if (IN_DEV_CONF_GET(in_dev
, NOPOLICY
))
2201 rth
->dst
.flags
|= DST_NOPOLICY
;
2202 rth
->fl
.fl4_dst
= daddr
;
2203 rth
->rt_dst
= daddr
;
2204 rth
->fl
.fl4_tos
= tos
;
2205 rth
->fl
.mark
= skb
->mark
;
2206 rth
->fl
.fl4_src
= saddr
;
2207 rth
->rt_src
= saddr
;
2208 #ifdef CONFIG_NET_CLS_ROUTE
2209 rth
->dst
.tclassid
= itag
;
2212 rth
->fl
.iif
= dev
->ifindex
;
2213 rth
->dst
.dev
= net
->loopback_dev
;
2214 dev_hold(rth
->dst
.dev
);
2215 rth
->idev
= in_dev_get(rth
->dst
.dev
);
2216 rth
->rt_gateway
= daddr
;
2217 rth
->rt_spec_dst
= spec_dst
;
2218 rth
->dst
.input
= ip_local_deliver
;
2219 rth
->rt_flags
= flags
|RTCF_LOCAL
;
2220 if (res
.type
== RTN_UNREACHABLE
) {
2221 rth
->dst
.input
= ip_error
;
2222 rth
->dst
.error
= -err
;
2223 rth
->rt_flags
&= ~RTCF_LOCAL
;
2225 rth
->rt_type
= res
.type
;
2226 hash
= rt_hash(daddr
, saddr
, fl
.iif
, rt_genid(net
));
2227 err
= rt_intern_hash(hash
, rth
, NULL
, skb
, fl
.iif
);
2231 RT_CACHE_STAT_INC(in_no_route
);
2232 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_UNIVERSE
);
2233 res
.type
= RTN_UNREACHABLE
;
2239 * Do not cache martian addresses: they should be logged (RFC1812)
2241 martian_destination
:
2242 RT_CACHE_STAT_INC(in_martian_dst
);
2243 #ifdef CONFIG_IP_ROUTE_VERBOSE
2244 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit())
2245 printk(KERN_WARNING
"martian destination %pI4 from %pI4, dev %s\n",
2246 &daddr
, &saddr
, dev
->name
);
2250 err
= -EHOSTUNREACH
;
2263 martian_source_keep_err
:
2264 ip_handle_martian_source(dev
, in_dev
, skb
, daddr
, saddr
);
2268 int ip_route_input_common(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2269 u8 tos
, struct net_device
*dev
, bool noref
)
2271 struct rtable
* rth
;
2273 int iif
= dev
->ifindex
;
2281 if (!rt_caching(net
))
2284 tos
&= IPTOS_RT_MASK
;
2285 hash
= rt_hash(daddr
, saddr
, iif
, rt_genid(net
));
2287 for (rth
= rcu_dereference(rt_hash_table
[hash
].chain
); rth
;
2288 rth
= rcu_dereference(rth
->dst
.rt_next
)) {
2289 if ((((__force u32
)rth
->fl
.fl4_dst
^ (__force u32
)daddr
) |
2290 ((__force u32
)rth
->fl
.fl4_src
^ (__force u32
)saddr
) |
2291 (rth
->fl
.iif
^ iif
) |
2293 (rth
->fl
.fl4_tos
^ tos
)) == 0 &&
2294 rth
->fl
.mark
== skb
->mark
&&
2295 net_eq(dev_net(rth
->dst
.dev
), net
) &&
2296 !rt_is_expired(rth
)) {
2298 dst_use_noref(&rth
->dst
, jiffies
);
2299 skb_dst_set_noref(skb
, &rth
->dst
);
2301 dst_use(&rth
->dst
, jiffies
);
2302 skb_dst_set(skb
, &rth
->dst
);
2304 RT_CACHE_STAT_INC(in_hit
);
2308 RT_CACHE_STAT_INC(in_hlist_search
);
2312 /* Multicast recognition logic is moved from route cache to here.
2313 The problem was that too many Ethernet cards have broken/missing
2314 hardware multicast filters :-( As result the host on multicasting
2315 network acquires a lot of useless route cache entries, sort of
2316 SDR messages from all the world. Now we try to get rid of them.
2317 Really, provided software IP multicast filter is organized
2318 reasonably (at least, hashed), it does not result in a slowdown
2319 comparing with route cache reject entries.
2320 Note, that multicast routers are not affected, because
2321 route cache entry is created eventually.
2323 if (ipv4_is_multicast(daddr
)) {
2324 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
2327 int our
= ip_check_mc(in_dev
, daddr
, saddr
,
2328 ip_hdr(skb
)->protocol
);
2330 #ifdef CONFIG_IP_MROUTE
2332 (!ipv4_is_local_multicast(daddr
) &&
2333 IN_DEV_MFORWARD(in_dev
))
2336 int res
= ip_route_input_mc(skb
, daddr
, saddr
,
2345 res
= ip_route_input_slow(skb
, daddr
, saddr
, tos
, dev
);
2349 EXPORT_SYMBOL(ip_route_input_common
);
2351 static int __mkroute_output(struct rtable
**result
,
2352 struct fib_result
*res
,
2353 const struct flowi
*fl
,
2354 const struct flowi
*oldflp
,
2355 struct net_device
*dev_out
,
2359 struct in_device
*in_dev
;
2360 u32 tos
= RT_FL_TOS(oldflp
);
2363 if (ipv4_is_loopback(fl
->fl4_src
) && !(dev_out
->flags
&IFF_LOOPBACK
))
2366 if (fl
->fl4_dst
== htonl(0xFFFFFFFF))
2367 res
->type
= RTN_BROADCAST
;
2368 else if (ipv4_is_multicast(fl
->fl4_dst
))
2369 res
->type
= RTN_MULTICAST
;
2370 else if (ipv4_is_lbcast(fl
->fl4_dst
) || ipv4_is_zeronet(fl
->fl4_dst
))
2373 if (dev_out
->flags
& IFF_LOOPBACK
)
2374 flags
|= RTCF_LOCAL
;
2376 /* get work reference to inet device */
2377 in_dev
= in_dev_get(dev_out
);
2381 if (res
->type
== RTN_BROADCAST
) {
2382 flags
|= RTCF_BROADCAST
| RTCF_LOCAL
;
2384 fib_info_put(res
->fi
);
2387 } else if (res
->type
== RTN_MULTICAST
) {
2388 flags
|= RTCF_MULTICAST
|RTCF_LOCAL
;
2389 if (!ip_check_mc(in_dev
, oldflp
->fl4_dst
, oldflp
->fl4_src
,
2391 flags
&= ~RTCF_LOCAL
;
2392 /* If multicast route do not exist use
2393 default one, but do not gateway in this case.
2396 if (res
->fi
&& res
->prefixlen
< 4) {
2397 fib_info_put(res
->fi
);
2403 rth
= dst_alloc(&ipv4_dst_ops
);
2409 atomic_set(&rth
->dst
.__refcnt
, 1);
2410 rth
->dst
.flags
= DST_HOST
;
2411 if (IN_DEV_CONF_GET(in_dev
, NOXFRM
))
2412 rth
->dst
.flags
|= DST_NOXFRM
;
2413 if (IN_DEV_CONF_GET(in_dev
, NOPOLICY
))
2414 rth
->dst
.flags
|= DST_NOPOLICY
;
2416 rth
->fl
.fl4_dst
= oldflp
->fl4_dst
;
2417 rth
->fl
.fl4_tos
= tos
;
2418 rth
->fl
.fl4_src
= oldflp
->fl4_src
;
2419 rth
->fl
.oif
= oldflp
->oif
;
2420 rth
->fl
.mark
= oldflp
->mark
;
2421 rth
->rt_dst
= fl
->fl4_dst
;
2422 rth
->rt_src
= fl
->fl4_src
;
2423 rth
->rt_iif
= oldflp
->oif
? : dev_out
->ifindex
;
2424 /* get references to the devices that are to be hold by the routing
2426 rth
->dst
.dev
= dev_out
;
2428 rth
->idev
= in_dev_get(dev_out
);
2429 rth
->rt_gateway
= fl
->fl4_dst
;
2430 rth
->rt_spec_dst
= fl
->fl4_src
;
2432 rth
->dst
.output
=ip_output
;
2433 rth
->dst
.obsolete
= -1;
2434 rth
->rt_genid
= rt_genid(dev_net(dev_out
));
2436 RT_CACHE_STAT_INC(out_slow_tot
);
2438 if (flags
& RTCF_LOCAL
) {
2439 rth
->dst
.input
= ip_local_deliver
;
2440 rth
->rt_spec_dst
= fl
->fl4_dst
;
2442 if (flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) {
2443 rth
->rt_spec_dst
= fl
->fl4_src
;
2444 if (flags
& RTCF_LOCAL
&&
2445 !(dev_out
->flags
& IFF_LOOPBACK
)) {
2446 rth
->dst
.output
= ip_mc_output
;
2447 RT_CACHE_STAT_INC(out_slow_mc
);
2449 #ifdef CONFIG_IP_MROUTE
2450 if (res
->type
== RTN_MULTICAST
) {
2451 if (IN_DEV_MFORWARD(in_dev
) &&
2452 !ipv4_is_local_multicast(oldflp
->fl4_dst
)) {
2453 rth
->dst
.input
= ip_mr_input
;
2454 rth
->dst
.output
= ip_mc_output
;
2460 rt_set_nexthop(rth
, res
, 0);
2462 rth
->rt_flags
= flags
;
2466 /* release work reference to inet device */
2472 static int ip_mkroute_output(struct rtable
**rp
,
2473 struct fib_result
*res
,
2474 const struct flowi
*fl
,
2475 const struct flowi
*oldflp
,
2476 struct net_device
*dev_out
,
2479 struct rtable
*rth
= NULL
;
2480 int err
= __mkroute_output(&rth
, res
, fl
, oldflp
, dev_out
, flags
);
2483 hash
= rt_hash(oldflp
->fl4_dst
, oldflp
->fl4_src
, oldflp
->oif
,
2484 rt_genid(dev_net(dev_out
)));
2485 err
= rt_intern_hash(hash
, rth
, rp
, NULL
, oldflp
->oif
);
2492 * Major route resolver routine.
2495 static int ip_route_output_slow(struct net
*net
, struct rtable
**rp
,
2496 const struct flowi
*oldflp
)
2498 u32 tos
= RT_FL_TOS(oldflp
);
2499 struct flowi fl
= { .nl_u
= { .ip4_u
=
2500 { .daddr
= oldflp
->fl4_dst
,
2501 .saddr
= oldflp
->fl4_src
,
2502 .tos
= tos
& IPTOS_RT_MASK
,
2503 .scope
= ((tos
& RTO_ONLINK
) ?
2507 .mark
= oldflp
->mark
,
2508 .iif
= net
->loopback_dev
->ifindex
,
2509 .oif
= oldflp
->oif
};
2510 struct fib_result res
;
2512 struct net_device
*dev_out
= NULL
;
2518 #ifdef CONFIG_IP_MULTIPLE_TABLES
2522 if (oldflp
->fl4_src
) {
2524 if (ipv4_is_multicast(oldflp
->fl4_src
) ||
2525 ipv4_is_lbcast(oldflp
->fl4_src
) ||
2526 ipv4_is_zeronet(oldflp
->fl4_src
))
2529 /* I removed check for oif == dev_out->oif here.
2530 It was wrong for two reasons:
2531 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2532 is assigned to multiple interfaces.
2533 2. Moreover, we are allowed to send packets with saddr
2534 of another iface. --ANK
2537 if (oldflp
->oif
== 0 &&
2538 (ipv4_is_multicast(oldflp
->fl4_dst
) ||
2539 oldflp
->fl4_dst
== htonl(0xFFFFFFFF))) {
2540 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2541 dev_out
= ip_dev_find(net
, oldflp
->fl4_src
);
2542 if (dev_out
== NULL
)
2545 /* Special hack: user can direct multicasts
2546 and limited broadcast via necessary interface
2547 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2548 This hack is not just for fun, it allows
2549 vic,vat and friends to work.
2550 They bind socket to loopback, set ttl to zero
2551 and expect that it will work.
2552 From the viewpoint of routing cache they are broken,
2553 because we are not allowed to build multicast path
2554 with loopback source addr (look, routing cache
2555 cannot know, that ttl is zero, so that packet
2556 will not leave this host and route is valid).
2557 Luckily, this hack is good workaround.
2560 fl
.oif
= dev_out
->ifindex
;
2564 if (!(oldflp
->flags
& FLOWI_FLAG_ANYSRC
)) {
2565 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2566 dev_out
= ip_dev_find(net
, oldflp
->fl4_src
);
2567 if (dev_out
== NULL
)
2576 dev_out
= dev_get_by_index(net
, oldflp
->oif
);
2578 if (dev_out
== NULL
)
2581 /* RACE: Check return value of inet_select_addr instead. */
2582 if (__in_dev_get_rtnl(dev_out
) == NULL
) {
2584 goto out
; /* Wrong error code */
2587 if (ipv4_is_local_multicast(oldflp
->fl4_dst
) ||
2588 oldflp
->fl4_dst
== htonl(0xFFFFFFFF)) {
2590 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2595 if (ipv4_is_multicast(oldflp
->fl4_dst
))
2596 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2598 else if (!oldflp
->fl4_dst
)
2599 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2605 fl
.fl4_dst
= fl
.fl4_src
;
2607 fl
.fl4_dst
= fl
.fl4_src
= htonl(INADDR_LOOPBACK
);
2610 dev_out
= net
->loopback_dev
;
2612 fl
.oif
= net
->loopback_dev
->ifindex
;
2613 res
.type
= RTN_LOCAL
;
2614 flags
|= RTCF_LOCAL
;
2618 if (fib_lookup(net
, &fl
, &res
)) {
2621 /* Apparently, routing tables are wrong. Assume,
2622 that the destination is on link.
2625 Because we are allowed to send to iface
2626 even if it has NO routes and NO assigned
2627 addresses. When oif is specified, routing
2628 tables are looked up with only one purpose:
2629 to catch if destination is gatewayed, rather than
2630 direct. Moreover, if MSG_DONTROUTE is set,
2631 we send packet, ignoring both routing tables
2632 and ifaddr state. --ANK
2635 We could make it even if oif is unknown,
2636 likely IPv6, but we do not.
2639 if (fl
.fl4_src
== 0)
2640 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2642 res
.type
= RTN_UNICAST
;
2652 if (res
.type
== RTN_LOCAL
) {
2654 fl
.fl4_src
= fl
.fl4_dst
;
2657 dev_out
= net
->loopback_dev
;
2659 fl
.oif
= dev_out
->ifindex
;
2661 fib_info_put(res
.fi
);
2663 flags
|= RTCF_LOCAL
;
2667 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2668 if (res
.fi
->fib_nhs
> 1 && fl
.oif
== 0)
2669 fib_select_multipath(&fl
, &res
);
2672 if (!res
.prefixlen
&& res
.type
== RTN_UNICAST
&& !fl
.oif
)
2673 fib_select_default(net
, &fl
, &res
);
2676 fl
.fl4_src
= FIB_RES_PREFSRC(res
);
2680 dev_out
= FIB_RES_DEV(res
);
2682 fl
.oif
= dev_out
->ifindex
;
2686 err
= ip_mkroute_output(rp
, &res
, &fl
, oldflp
, dev_out
, flags
);
2696 int __ip_route_output_key(struct net
*net
, struct rtable
**rp
,
2697 const struct flowi
*flp
)
2702 if (!rt_caching(net
))
2705 hash
= rt_hash(flp
->fl4_dst
, flp
->fl4_src
, flp
->oif
, rt_genid(net
));
2708 for (rth
= rcu_dereference_bh(rt_hash_table
[hash
].chain
); rth
;
2709 rth
= rcu_dereference_bh(rth
->dst
.rt_next
)) {
2710 if (rth
->fl
.fl4_dst
== flp
->fl4_dst
&&
2711 rth
->fl
.fl4_src
== flp
->fl4_src
&&
2713 rth
->fl
.oif
== flp
->oif
&&
2714 rth
->fl
.mark
== flp
->mark
&&
2715 !((rth
->fl
.fl4_tos
^ flp
->fl4_tos
) &
2716 (IPTOS_RT_MASK
| RTO_ONLINK
)) &&
2717 net_eq(dev_net(rth
->dst
.dev
), net
) &&
2718 !rt_is_expired(rth
)) {
2719 dst_use(&rth
->dst
, jiffies
);
2720 RT_CACHE_STAT_INC(out_hit
);
2721 rcu_read_unlock_bh();
2725 RT_CACHE_STAT_INC(out_hlist_search
);
2727 rcu_read_unlock_bh();
2730 return ip_route_output_slow(net
, rp
, flp
);
2732 EXPORT_SYMBOL_GPL(__ip_route_output_key
);
2734 static struct dst_entry
*ipv4_blackhole_dst_check(struct dst_entry
*dst
, u32 cookie
)
2739 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry
*dst
, u32 mtu
)
2743 static struct dst_ops ipv4_dst_blackhole_ops
= {
2745 .protocol
= cpu_to_be16(ETH_P_IP
),
2746 .destroy
= ipv4_dst_destroy
,
2747 .check
= ipv4_blackhole_dst_check
,
2748 .update_pmtu
= ipv4_rt_blackhole_update_pmtu
,
2749 .entries
= ATOMIC_INIT(0),
2753 static int ipv4_dst_blackhole(struct net
*net
, struct rtable
**rp
, struct flowi
*flp
)
2755 struct rtable
*ort
= *rp
;
2756 struct rtable
*rt
= (struct rtable
*)
2757 dst_alloc(&ipv4_dst_blackhole_ops
);
2760 struct dst_entry
*new = &rt
->dst
;
2762 atomic_set(&new->__refcnt
, 1);
2764 new->input
= dst_discard
;
2765 new->output
= dst_discard
;
2766 memcpy(new->metrics
, ort
->dst
.metrics
, RTAX_MAX
*sizeof(u32
));
2768 new->dev
= ort
->dst
.dev
;
2774 rt
->idev
= ort
->idev
;
2776 in_dev_hold(rt
->idev
);
2777 rt
->rt_genid
= rt_genid(net
);
2778 rt
->rt_flags
= ort
->rt_flags
;
2779 rt
->rt_type
= ort
->rt_type
;
2780 rt
->rt_dst
= ort
->rt_dst
;
2781 rt
->rt_src
= ort
->rt_src
;
2782 rt
->rt_iif
= ort
->rt_iif
;
2783 rt
->rt_gateway
= ort
->rt_gateway
;
2784 rt
->rt_spec_dst
= ort
->rt_spec_dst
;
2785 rt
->peer
= ort
->peer
;
2787 atomic_inc(&rt
->peer
->refcnt
);
2792 dst_release(&(*rp
)->dst
);
2794 return rt
? 0 : -ENOMEM
;
2797 int ip_route_output_flow(struct net
*net
, struct rtable
**rp
, struct flowi
*flp
,
2798 struct sock
*sk
, int flags
)
2802 if ((err
= __ip_route_output_key(net
, rp
, flp
)) != 0)
2807 flp
->fl4_src
= (*rp
)->rt_src
;
2809 flp
->fl4_dst
= (*rp
)->rt_dst
;
2810 err
= __xfrm_lookup(net
, (struct dst_entry
**)rp
, flp
, sk
,
2811 flags
? XFRM_LOOKUP_WAIT
: 0);
2812 if (err
== -EREMOTE
)
2813 err
= ipv4_dst_blackhole(net
, rp
, flp
);
2820 EXPORT_SYMBOL_GPL(ip_route_output_flow
);
2822 int ip_route_output_key(struct net
*net
, struct rtable
**rp
, struct flowi
*flp
)
2824 return ip_route_output_flow(net
, rp
, flp
, NULL
, 0);
2826 EXPORT_SYMBOL(ip_route_output_key
);
2828 static int rt_fill_info(struct net
*net
,
2829 struct sk_buff
*skb
, u32 pid
, u32 seq
, int event
,
2830 int nowait
, unsigned int flags
)
2832 struct rtable
*rt
= skb_rtable(skb
);
2834 struct nlmsghdr
*nlh
;
2836 u32 id
= 0, ts
= 0, tsage
= 0, error
;
2838 nlh
= nlmsg_put(skb
, pid
, seq
, event
, sizeof(*r
), flags
);
2842 r
= nlmsg_data(nlh
);
2843 r
->rtm_family
= AF_INET
;
2844 r
->rtm_dst_len
= 32;
2846 r
->rtm_tos
= rt
->fl
.fl4_tos
;
2847 r
->rtm_table
= RT_TABLE_MAIN
;
2848 NLA_PUT_U32(skb
, RTA_TABLE
, RT_TABLE_MAIN
);
2849 r
->rtm_type
= rt
->rt_type
;
2850 r
->rtm_scope
= RT_SCOPE_UNIVERSE
;
2851 r
->rtm_protocol
= RTPROT_UNSPEC
;
2852 r
->rtm_flags
= (rt
->rt_flags
& ~0xFFFF) | RTM_F_CLONED
;
2853 if (rt
->rt_flags
& RTCF_NOTIFY
)
2854 r
->rtm_flags
|= RTM_F_NOTIFY
;
2856 NLA_PUT_BE32(skb
, RTA_DST
, rt
->rt_dst
);
2858 if (rt
->fl
.fl4_src
) {
2859 r
->rtm_src_len
= 32;
2860 NLA_PUT_BE32(skb
, RTA_SRC
, rt
->fl
.fl4_src
);
2863 NLA_PUT_U32(skb
, RTA_OIF
, rt
->dst
.dev
->ifindex
);
2864 #ifdef CONFIG_NET_CLS_ROUTE
2865 if (rt
->dst
.tclassid
)
2866 NLA_PUT_U32(skb
, RTA_FLOW
, rt
->dst
.tclassid
);
2869 NLA_PUT_BE32(skb
, RTA_PREFSRC
, rt
->rt_spec_dst
);
2870 else if (rt
->rt_src
!= rt
->fl
.fl4_src
)
2871 NLA_PUT_BE32(skb
, RTA_PREFSRC
, rt
->rt_src
);
2873 if (rt
->rt_dst
!= rt
->rt_gateway
)
2874 NLA_PUT_BE32(skb
, RTA_GATEWAY
, rt
->rt_gateway
);
2876 if (rtnetlink_put_metrics(skb
, rt
->dst
.metrics
) < 0)
2877 goto nla_put_failure
;
2880 NLA_PUT_BE32(skb
, RTA_MARK
, rt
->fl
.mark
);
2882 error
= rt
->dst
.error
;
2883 expires
= rt
->dst
.expires
? rt
->dst
.expires
- jiffies
: 0;
2885 inet_peer_refcheck(rt
->peer
);
2886 id
= atomic_read(&rt
->peer
->ip_id_count
) & 0xffff;
2887 if (rt
->peer
->tcp_ts_stamp
) {
2888 ts
= rt
->peer
->tcp_ts
;
2889 tsage
= get_seconds() - rt
->peer
->tcp_ts_stamp
;
2894 #ifdef CONFIG_IP_MROUTE
2895 __be32 dst
= rt
->rt_dst
;
2897 if (ipv4_is_multicast(dst
) && !ipv4_is_local_multicast(dst
) &&
2898 IPV4_DEVCONF_ALL(net
, MC_FORWARDING
)) {
2899 int err
= ipmr_get_route(net
, skb
, r
, nowait
);
2904 goto nla_put_failure
;
2906 if (err
== -EMSGSIZE
)
2907 goto nla_put_failure
;
2913 NLA_PUT_U32(skb
, RTA_IIF
, rt
->fl
.iif
);
2916 if (rtnl_put_cacheinfo(skb
, &rt
->dst
, id
, ts
, tsage
,
2917 expires
, error
) < 0)
2918 goto nla_put_failure
;
2920 return nlmsg_end(skb
, nlh
);
2923 nlmsg_cancel(skb
, nlh
);
2927 static int inet_rtm_getroute(struct sk_buff
*in_skb
, struct nlmsghdr
* nlh
, void *arg
)
2929 struct net
*net
= sock_net(in_skb
->sk
);
2931 struct nlattr
*tb
[RTA_MAX
+1];
2932 struct rtable
*rt
= NULL
;
2938 struct sk_buff
*skb
;
2940 err
= nlmsg_parse(nlh
, sizeof(*rtm
), tb
, RTA_MAX
, rtm_ipv4_policy
);
2944 rtm
= nlmsg_data(nlh
);
2946 skb
= alloc_skb(NLMSG_GOODSIZE
, GFP_KERNEL
);
2952 /* Reserve room for dummy headers, this skb can pass
2953 through good chunk of routing engine.
2955 skb_reset_mac_header(skb
);
2956 skb_reset_network_header(skb
);
2958 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2959 ip_hdr(skb
)->protocol
= IPPROTO_ICMP
;
2960 skb_reserve(skb
, MAX_HEADER
+ sizeof(struct iphdr
));
2962 src
= tb
[RTA_SRC
] ? nla_get_be32(tb
[RTA_SRC
]) : 0;
2963 dst
= tb
[RTA_DST
] ? nla_get_be32(tb
[RTA_DST
]) : 0;
2964 iif
= tb
[RTA_IIF
] ? nla_get_u32(tb
[RTA_IIF
]) : 0;
2965 mark
= tb
[RTA_MARK
] ? nla_get_u32(tb
[RTA_MARK
]) : 0;
2968 struct net_device
*dev
;
2970 dev
= __dev_get_by_index(net
, iif
);
2976 skb
->protocol
= htons(ETH_P_IP
);
2980 err
= ip_route_input(skb
, dst
, src
, rtm
->rtm_tos
, dev
);
2983 rt
= skb_rtable(skb
);
2984 if (err
== 0 && rt
->dst
.error
)
2985 err
= -rt
->dst
.error
;
2992 .tos
= rtm
->rtm_tos
,
2995 .oif
= tb
[RTA_OIF
] ? nla_get_u32(tb
[RTA_OIF
]) : 0,
2998 err
= ip_route_output_key(net
, &rt
, &fl
);
3004 skb_dst_set(skb
, &rt
->dst
);
3005 if (rtm
->rtm_flags
& RTM_F_NOTIFY
)
3006 rt
->rt_flags
|= RTCF_NOTIFY
;
3008 err
= rt_fill_info(net
, skb
, NETLINK_CB(in_skb
).pid
, nlh
->nlmsg_seq
,
3009 RTM_NEWROUTE
, 0, 0);
3013 err
= rtnl_unicast(skb
, net
, NETLINK_CB(in_skb
).pid
);
3022 int ip_rt_dump(struct sk_buff
*skb
, struct netlink_callback
*cb
)
3029 net
= sock_net(skb
->sk
);
3034 s_idx
= idx
= cb
->args
[1];
3035 for (h
= s_h
; h
<= rt_hash_mask
; h
++, s_idx
= 0) {
3036 if (!rt_hash_table
[h
].chain
)
3039 for (rt
= rcu_dereference_bh(rt_hash_table
[h
].chain
), idx
= 0; rt
;
3040 rt
= rcu_dereference_bh(rt
->dst
.rt_next
), idx
++) {
3041 if (!net_eq(dev_net(rt
->dst
.dev
), net
) || idx
< s_idx
)
3043 if (rt_is_expired(rt
))
3045 skb_dst_set_noref(skb
, &rt
->dst
);
3046 if (rt_fill_info(net
, skb
, NETLINK_CB(cb
->skb
).pid
,
3047 cb
->nlh
->nlmsg_seq
, RTM_NEWROUTE
,
3048 1, NLM_F_MULTI
) <= 0) {
3050 rcu_read_unlock_bh();
3055 rcu_read_unlock_bh();
3064 void ip_rt_multicast_event(struct in_device
*in_dev
)
3066 rt_cache_flush(dev_net(in_dev
->dev
), 0);
3069 #ifdef CONFIG_SYSCTL
3070 static int ipv4_sysctl_rtcache_flush(ctl_table
*__ctl
, int write
,
3071 void __user
*buffer
,
3072 size_t *lenp
, loff_t
*ppos
)
3079 memcpy(&ctl
, __ctl
, sizeof(ctl
));
3080 ctl
.data
= &flush_delay
;
3081 proc_dointvec(&ctl
, write
, buffer
, lenp
, ppos
);
3083 net
= (struct net
*)__ctl
->extra1
;
3084 rt_cache_flush(net
, flush_delay
);
3091 static ctl_table ipv4_route_table
[] = {
3093 .procname
= "gc_thresh",
3094 .data
= &ipv4_dst_ops
.gc_thresh
,
3095 .maxlen
= sizeof(int),
3097 .proc_handler
= proc_dointvec
,
3100 .procname
= "max_size",
3101 .data
= &ip_rt_max_size
,
3102 .maxlen
= sizeof(int),
3104 .proc_handler
= proc_dointvec
,
3107 /* Deprecated. Use gc_min_interval_ms */
3109 .procname
= "gc_min_interval",
3110 .data
= &ip_rt_gc_min_interval
,
3111 .maxlen
= sizeof(int),
3113 .proc_handler
= proc_dointvec_jiffies
,
3116 .procname
= "gc_min_interval_ms",
3117 .data
= &ip_rt_gc_min_interval
,
3118 .maxlen
= sizeof(int),
3120 .proc_handler
= proc_dointvec_ms_jiffies
,
3123 .procname
= "gc_timeout",
3124 .data
= &ip_rt_gc_timeout
,
3125 .maxlen
= sizeof(int),
3127 .proc_handler
= proc_dointvec_jiffies
,
3130 .procname
= "gc_interval",
3131 .data
= &ip_rt_gc_interval
,
3132 .maxlen
= sizeof(int),
3134 .proc_handler
= proc_dointvec_jiffies
,
3137 .procname
= "redirect_load",
3138 .data
= &ip_rt_redirect_load
,
3139 .maxlen
= sizeof(int),
3141 .proc_handler
= proc_dointvec
,
3144 .procname
= "redirect_number",
3145 .data
= &ip_rt_redirect_number
,
3146 .maxlen
= sizeof(int),
3148 .proc_handler
= proc_dointvec
,
3151 .procname
= "redirect_silence",
3152 .data
= &ip_rt_redirect_silence
,
3153 .maxlen
= sizeof(int),
3155 .proc_handler
= proc_dointvec
,
3158 .procname
= "error_cost",
3159 .data
= &ip_rt_error_cost
,
3160 .maxlen
= sizeof(int),
3162 .proc_handler
= proc_dointvec
,
3165 .procname
= "error_burst",
3166 .data
= &ip_rt_error_burst
,
3167 .maxlen
= sizeof(int),
3169 .proc_handler
= proc_dointvec
,
3172 .procname
= "gc_elasticity",
3173 .data
= &ip_rt_gc_elasticity
,
3174 .maxlen
= sizeof(int),
3176 .proc_handler
= proc_dointvec
,
3179 .procname
= "mtu_expires",
3180 .data
= &ip_rt_mtu_expires
,
3181 .maxlen
= sizeof(int),
3183 .proc_handler
= proc_dointvec_jiffies
,
3186 .procname
= "min_pmtu",
3187 .data
= &ip_rt_min_pmtu
,
3188 .maxlen
= sizeof(int),
3190 .proc_handler
= proc_dointvec
,
3193 .procname
= "min_adv_mss",
3194 .data
= &ip_rt_min_advmss
,
3195 .maxlen
= sizeof(int),
3197 .proc_handler
= proc_dointvec
,
3202 static struct ctl_table empty
[1];
3204 static struct ctl_table ipv4_skeleton
[] =
3206 { .procname
= "route",
3207 .mode
= 0555, .child
= ipv4_route_table
},
3208 { .procname
= "neigh",
3209 .mode
= 0555, .child
= empty
},
3213 static __net_initdata
struct ctl_path ipv4_path
[] = {
3214 { .procname
= "net", },
3215 { .procname
= "ipv4", },
3219 static struct ctl_table ipv4_route_flush_table
[] = {
3221 .procname
= "flush",
3222 .maxlen
= sizeof(int),
3224 .proc_handler
= ipv4_sysctl_rtcache_flush
,
3229 static __net_initdata
struct ctl_path ipv4_route_path
[] = {
3230 { .procname
= "net", },
3231 { .procname
= "ipv4", },
3232 { .procname
= "route", },
3236 static __net_init
int sysctl_route_net_init(struct net
*net
)
3238 struct ctl_table
*tbl
;
3240 tbl
= ipv4_route_flush_table
;
3241 if (!net_eq(net
, &init_net
)) {
3242 tbl
= kmemdup(tbl
, sizeof(ipv4_route_flush_table
), GFP_KERNEL
);
3246 tbl
[0].extra1
= net
;
3248 net
->ipv4
.route_hdr
=
3249 register_net_sysctl_table(net
, ipv4_route_path
, tbl
);
3250 if (net
->ipv4
.route_hdr
== NULL
)
3255 if (tbl
!= ipv4_route_flush_table
)
3261 static __net_exit
void sysctl_route_net_exit(struct net
*net
)
3263 struct ctl_table
*tbl
;
3265 tbl
= net
->ipv4
.route_hdr
->ctl_table_arg
;
3266 unregister_net_sysctl_table(net
->ipv4
.route_hdr
);
3267 BUG_ON(tbl
== ipv4_route_flush_table
);
3271 static __net_initdata
struct pernet_operations sysctl_route_ops
= {
3272 .init
= sysctl_route_net_init
,
3273 .exit
= sysctl_route_net_exit
,
3277 static __net_init
int rt_genid_init(struct net
*net
)
3279 get_random_bytes(&net
->ipv4
.rt_genid
,
3280 sizeof(net
->ipv4
.rt_genid
));
3284 static __net_initdata
struct pernet_operations rt_genid_ops
= {
3285 .init
= rt_genid_init
,
3289 #ifdef CONFIG_NET_CLS_ROUTE
3290 struct ip_rt_acct __percpu
*ip_rt_acct __read_mostly
;
3291 #endif /* CONFIG_NET_CLS_ROUTE */
3293 static __initdata
unsigned long rhash_entries
;
3294 static int __init
set_rhash_entries(char *str
)
3298 rhash_entries
= simple_strtoul(str
, &str
, 0);
3301 __setup("rhash_entries=", set_rhash_entries
);
3303 int __init
ip_rt_init(void)
3307 #ifdef CONFIG_NET_CLS_ROUTE
3308 ip_rt_acct
= __alloc_percpu(256 * sizeof(struct ip_rt_acct
), __alignof__(struct ip_rt_acct
));
3310 panic("IP: failed to allocate ip_rt_acct\n");
3313 ipv4_dst_ops
.kmem_cachep
=
3314 kmem_cache_create("ip_dst_cache", sizeof(struct rtable
), 0,
3315 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3317 ipv4_dst_blackhole_ops
.kmem_cachep
= ipv4_dst_ops
.kmem_cachep
;
3319 rt_hash_table
= (struct rt_hash_bucket
*)
3320 alloc_large_system_hash("IP route cache",
3321 sizeof(struct rt_hash_bucket
),
3323 (totalram_pages
>= 128 * 1024) ?
3328 rhash_entries
? 0 : 512 * 1024);
3329 memset(rt_hash_table
, 0, (rt_hash_mask
+ 1) * sizeof(struct rt_hash_bucket
));
3330 rt_hash_lock_init();
3332 ipv4_dst_ops
.gc_thresh
= (rt_hash_mask
+ 1);
3333 ip_rt_max_size
= (rt_hash_mask
+ 1) * 16;
3338 /* All the timers, started at system startup tend
3339 to synchronize. Perturb it a bit.
3341 INIT_DELAYED_WORK_DEFERRABLE(&expires_work
, rt_worker_func
);
3342 expires_ljiffies
= jiffies
;
3343 schedule_delayed_work(&expires_work
,
3344 net_random() % ip_rt_gc_interval
+ ip_rt_gc_interval
);
3346 if (ip_rt_proc_init())
3347 printk(KERN_ERR
"Unable to create route proc files\n");
3350 xfrm4_init(ip_rt_max_size
);
3352 rtnl_register(PF_INET
, RTM_GETROUTE
, inet_rtm_getroute
, NULL
);
3354 #ifdef CONFIG_SYSCTL
3355 register_pernet_subsys(&sysctl_route_ops
);
3357 register_pernet_subsys(&rt_genid_ops
);
3361 #ifdef CONFIG_SYSCTL
3363 * We really need to sanitize the damn ipv4 init order, then all
3364 * this nonsense will go away.
3366 void __init
ip_static_sysctl_init(void)
3368 register_sysctl_paths(ipv4_path
, ipv4_skeleton
);