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>
94 #include <net/net_namespace.h>
95 #include <net/protocol.h>
97 #include <net/route.h>
98 #include <net/inetpeer.h>
100 #include <net/ip_fib.h>
103 #include <net/icmp.h>
104 #include <net/xfrm.h>
105 #include <net/netevent.h>
106 #include <net/rtnetlink.h>
108 #include <linux/sysctl.h>
111 #define RT_FL_TOS(oldflp) \
112 ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
114 #define IP_MAX_MTU 0xFFF0
116 #define RT_GC_TIMEOUT (300*HZ)
118 static int ip_rt_max_size
;
119 static int ip_rt_gc_timeout __read_mostly
= RT_GC_TIMEOUT
;
120 static int ip_rt_gc_interval __read_mostly
= 60 * HZ
;
121 static int ip_rt_gc_min_interval __read_mostly
= HZ
/ 2;
122 static int ip_rt_redirect_number __read_mostly
= 9;
123 static int ip_rt_redirect_load __read_mostly
= HZ
/ 50;
124 static int ip_rt_redirect_silence __read_mostly
= ((HZ
/ 50) << (9 + 1));
125 static int ip_rt_error_cost __read_mostly
= HZ
;
126 static int ip_rt_error_burst __read_mostly
= 5 * HZ
;
127 static int ip_rt_gc_elasticity __read_mostly
= 8;
128 static int ip_rt_mtu_expires __read_mostly
= 10 * 60 * HZ
;
129 static int ip_rt_min_pmtu __read_mostly
= 512 + 20 + 20;
130 static int ip_rt_min_advmss __read_mostly
= 256;
131 static int ip_rt_secret_interval __read_mostly
= 10 * 60 * HZ
;
132 static int rt_chain_length_max __read_mostly
= 20;
134 static void rt_worker_func(struct work_struct
*work
);
135 static DECLARE_DELAYED_WORK(expires_work
, rt_worker_func
);
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
);
149 static void rt_emergency_hash_rebuild(struct net
*net
);
152 static struct dst_ops ipv4_dst_ops
= {
154 .protocol
= __constant_htons(ETH_P_IP
),
155 .gc
= rt_garbage_collect
,
156 .check
= ipv4_dst_check
,
157 .destroy
= ipv4_dst_destroy
,
158 .ifdown
= ipv4_dst_ifdown
,
159 .negative_advice
= ipv4_negative_advice
,
160 .link_failure
= ipv4_link_failure
,
161 .update_pmtu
= ip_rt_update_pmtu
,
162 .local_out
= __ip_local_out
,
163 .entry_size
= sizeof(struct rtable
),
164 .entries
= ATOMIC_INIT(0),
167 #define ECN_OR_COST(class) TC_PRIO_##class
169 const __u8 ip_tos2prio
[16] = {
173 ECN_OR_COST(BESTEFFORT
),
179 ECN_OR_COST(INTERACTIVE
),
181 ECN_OR_COST(INTERACTIVE
),
182 TC_PRIO_INTERACTIVE_BULK
,
183 ECN_OR_COST(INTERACTIVE_BULK
),
184 TC_PRIO_INTERACTIVE_BULK
,
185 ECN_OR_COST(INTERACTIVE_BULK
)
193 /* The locking scheme is rather straight forward:
195 * 1) Read-Copy Update protects the buckets of the central route hash.
196 * 2) Only writers remove entries, and they hold the lock
197 * as they look at rtable reference counts.
198 * 3) Only readers acquire references to rtable entries,
199 * they do so with atomic increments and with the
203 struct rt_hash_bucket
{
204 struct rtable
*chain
;
207 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
208 defined(CONFIG_PROVE_LOCKING)
210 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
211 * The size of this table is a power of two and depends on the number of CPUS.
212 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
214 #ifdef CONFIG_LOCKDEP
215 # define RT_HASH_LOCK_SZ 256
218 # define RT_HASH_LOCK_SZ 4096
220 # define RT_HASH_LOCK_SZ 2048
222 # define RT_HASH_LOCK_SZ 1024
224 # define RT_HASH_LOCK_SZ 512
226 # define RT_HASH_LOCK_SZ 256
230 static spinlock_t
*rt_hash_locks
;
231 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
233 static __init
void rt_hash_lock_init(void)
237 rt_hash_locks
= kmalloc(sizeof(spinlock_t
) * RT_HASH_LOCK_SZ
,
240 panic("IP: failed to allocate rt_hash_locks\n");
242 for (i
= 0; i
< RT_HASH_LOCK_SZ
; i
++)
243 spin_lock_init(&rt_hash_locks
[i
]);
246 # define rt_hash_lock_addr(slot) NULL
248 static inline void rt_hash_lock_init(void)
253 static struct rt_hash_bucket
*rt_hash_table __read_mostly
;
254 static unsigned rt_hash_mask __read_mostly
;
255 static unsigned int rt_hash_log __read_mostly
;
257 static DEFINE_PER_CPU(struct rt_cache_stat
, rt_cache_stat
);
258 #define RT_CACHE_STAT_INC(field) \
259 (__raw_get_cpu_var(rt_cache_stat).field++)
261 static inline unsigned int rt_hash(__be32 daddr
, __be32 saddr
, int idx
,
264 return jhash_3words((__force u32
)(__be32
)(daddr
),
265 (__force u32
)(__be32
)(saddr
),
270 static inline int rt_genid(struct net
*net
)
272 return atomic_read(&net
->ipv4
.rt_genid
);
275 #ifdef CONFIG_PROC_FS
276 struct rt_cache_iter_state
{
277 struct seq_net_private p
;
282 static struct rtable
*rt_cache_get_first(struct seq_file
*seq
)
284 struct rt_cache_iter_state
*st
= seq
->private;
285 struct rtable
*r
= NULL
;
287 for (st
->bucket
= rt_hash_mask
; st
->bucket
>= 0; --st
->bucket
) {
288 if (!rt_hash_table
[st
->bucket
].chain
)
291 r
= rcu_dereference(rt_hash_table
[st
->bucket
].chain
);
293 if (dev_net(r
->u
.dst
.dev
) == seq_file_net(seq
) &&
294 r
->rt_genid
== st
->genid
)
296 r
= rcu_dereference(r
->u
.dst
.rt_next
);
298 rcu_read_unlock_bh();
303 static struct rtable
*__rt_cache_get_next(struct seq_file
*seq
,
306 struct rt_cache_iter_state
*st
= seq
->private;
308 r
= r
->u
.dst
.rt_next
;
310 rcu_read_unlock_bh();
312 if (--st
->bucket
< 0)
314 } while (!rt_hash_table
[st
->bucket
].chain
);
316 r
= rt_hash_table
[st
->bucket
].chain
;
318 return rcu_dereference(r
);
321 static struct rtable
*rt_cache_get_next(struct seq_file
*seq
,
324 struct rt_cache_iter_state
*st
= seq
->private;
325 while ((r
= __rt_cache_get_next(seq
, r
)) != NULL
) {
326 if (dev_net(r
->u
.dst
.dev
) != seq_file_net(seq
))
328 if (r
->rt_genid
== st
->genid
)
334 static struct rtable
*rt_cache_get_idx(struct seq_file
*seq
, loff_t pos
)
336 struct rtable
*r
= rt_cache_get_first(seq
);
339 while (pos
&& (r
= rt_cache_get_next(seq
, r
)))
341 return pos
? NULL
: r
;
344 static void *rt_cache_seq_start(struct seq_file
*seq
, loff_t
*pos
)
346 struct rt_cache_iter_state
*st
= seq
->private;
348 return rt_cache_get_idx(seq
, *pos
- 1);
349 st
->genid
= rt_genid(seq_file_net(seq
));
350 return SEQ_START_TOKEN
;
353 static void *rt_cache_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
357 if (v
== SEQ_START_TOKEN
)
358 r
= rt_cache_get_first(seq
);
360 r
= rt_cache_get_next(seq
, v
);
365 static void rt_cache_seq_stop(struct seq_file
*seq
, void *v
)
367 if (v
&& v
!= SEQ_START_TOKEN
)
368 rcu_read_unlock_bh();
371 static int rt_cache_seq_show(struct seq_file
*seq
, void *v
)
373 if (v
== SEQ_START_TOKEN
)
374 seq_printf(seq
, "%-127s\n",
375 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
376 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
379 struct rtable
*r
= v
;
382 seq_printf(seq
, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
383 "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
384 r
->u
.dst
.dev
? r
->u
.dst
.dev
->name
: "*",
385 (unsigned long)r
->rt_dst
, (unsigned long)r
->rt_gateway
,
386 r
->rt_flags
, atomic_read(&r
->u
.dst
.__refcnt
),
387 r
->u
.dst
.__use
, 0, (unsigned long)r
->rt_src
,
388 (dst_metric(&r
->u
.dst
, RTAX_ADVMSS
) ?
389 (int)dst_metric(&r
->u
.dst
, RTAX_ADVMSS
) + 40 : 0),
390 dst_metric(&r
->u
.dst
, RTAX_WINDOW
),
391 (int)((dst_metric(&r
->u
.dst
, RTAX_RTT
) >> 3) +
392 dst_metric(&r
->u
.dst
, RTAX_RTTVAR
)),
394 r
->u
.dst
.hh
? atomic_read(&r
->u
.dst
.hh
->hh_refcnt
) : -1,
395 r
->u
.dst
.hh
? (r
->u
.dst
.hh
->hh_output
==
397 r
->rt_spec_dst
, &len
);
399 seq_printf(seq
, "%*s\n", 127 - len
, "");
404 static const struct seq_operations rt_cache_seq_ops
= {
405 .start
= rt_cache_seq_start
,
406 .next
= rt_cache_seq_next
,
407 .stop
= rt_cache_seq_stop
,
408 .show
= rt_cache_seq_show
,
411 static int rt_cache_seq_open(struct inode
*inode
, struct file
*file
)
413 return seq_open_net(inode
, file
, &rt_cache_seq_ops
,
414 sizeof(struct rt_cache_iter_state
));
417 static const struct file_operations rt_cache_seq_fops
= {
418 .owner
= THIS_MODULE
,
419 .open
= rt_cache_seq_open
,
422 .release
= seq_release_net
,
426 static void *rt_cpu_seq_start(struct seq_file
*seq
, loff_t
*pos
)
431 return SEQ_START_TOKEN
;
433 for (cpu
= *pos
-1; cpu
< NR_CPUS
; ++cpu
) {
434 if (!cpu_possible(cpu
))
437 return &per_cpu(rt_cache_stat
, cpu
);
442 static void *rt_cpu_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
446 for (cpu
= *pos
; cpu
< NR_CPUS
; ++cpu
) {
447 if (!cpu_possible(cpu
))
450 return &per_cpu(rt_cache_stat
, cpu
);
456 static void rt_cpu_seq_stop(struct seq_file
*seq
, void *v
)
461 static int rt_cpu_seq_show(struct seq_file
*seq
, void *v
)
463 struct rt_cache_stat
*st
= v
;
465 if (v
== SEQ_START_TOKEN
) {
466 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");
470 seq_printf(seq
,"%08x %08x %08x %08x %08x %08x %08x %08x "
471 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
472 atomic_read(&ipv4_dst_ops
.entries
),
495 static const struct seq_operations rt_cpu_seq_ops
= {
496 .start
= rt_cpu_seq_start
,
497 .next
= rt_cpu_seq_next
,
498 .stop
= rt_cpu_seq_stop
,
499 .show
= rt_cpu_seq_show
,
503 static int rt_cpu_seq_open(struct inode
*inode
, struct file
*file
)
505 return seq_open(file
, &rt_cpu_seq_ops
);
508 static const struct file_operations rt_cpu_seq_fops
= {
509 .owner
= THIS_MODULE
,
510 .open
= rt_cpu_seq_open
,
513 .release
= seq_release
,
516 #ifdef CONFIG_NET_CLS_ROUTE
517 static int ip_rt_acct_read(char *buffer
, char **start
, off_t offset
,
518 int length
, int *eof
, void *data
)
522 if ((offset
& 3) || (length
& 3))
525 if (offset
>= sizeof(struct ip_rt_acct
) * 256) {
530 if (offset
+ length
>= sizeof(struct ip_rt_acct
) * 256) {
531 length
= sizeof(struct ip_rt_acct
) * 256 - offset
;
535 offset
/= sizeof(u32
);
538 u32
*dst
= (u32
*) buffer
;
541 memset(dst
, 0, length
);
543 for_each_possible_cpu(i
) {
547 src
= ((u32
*) per_cpu_ptr(ip_rt_acct
, i
)) + offset
;
548 for (j
= 0; j
< length
/4; j
++)
556 static int __net_init
ip_rt_do_proc_init(struct net
*net
)
558 struct proc_dir_entry
*pde
;
560 pde
= proc_net_fops_create(net
, "rt_cache", S_IRUGO
,
565 pde
= proc_create("rt_cache", S_IRUGO
,
566 net
->proc_net_stat
, &rt_cpu_seq_fops
);
570 #ifdef CONFIG_NET_CLS_ROUTE
571 pde
= create_proc_read_entry("rt_acct", 0, net
->proc_net
,
572 ip_rt_acct_read
, NULL
);
578 #ifdef CONFIG_NET_CLS_ROUTE
580 remove_proc_entry("rt_cache", net
->proc_net_stat
);
583 remove_proc_entry("rt_cache", net
->proc_net
);
588 static void __net_exit
ip_rt_do_proc_exit(struct net
*net
)
590 remove_proc_entry("rt_cache", net
->proc_net_stat
);
591 remove_proc_entry("rt_cache", net
->proc_net
);
592 remove_proc_entry("rt_acct", net
->proc_net
);
595 static struct pernet_operations ip_rt_proc_ops __net_initdata
= {
596 .init
= ip_rt_do_proc_init
,
597 .exit
= ip_rt_do_proc_exit
,
600 static int __init
ip_rt_proc_init(void)
602 return register_pernet_subsys(&ip_rt_proc_ops
);
606 static inline int ip_rt_proc_init(void)
610 #endif /* CONFIG_PROC_FS */
612 static inline void rt_free(struct rtable
*rt
)
614 call_rcu_bh(&rt
->u
.dst
.rcu_head
, dst_rcu_free
);
617 static inline void rt_drop(struct rtable
*rt
)
620 call_rcu_bh(&rt
->u
.dst
.rcu_head
, dst_rcu_free
);
623 static inline int rt_fast_clean(struct rtable
*rth
)
625 /* Kill broadcast/multicast entries very aggresively, if they
626 collide in hash table with more useful entries */
627 return (rth
->rt_flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) &&
628 rth
->fl
.iif
&& rth
->u
.dst
.rt_next
;
631 static inline int rt_valuable(struct rtable
*rth
)
633 return (rth
->rt_flags
& (RTCF_REDIRECTED
| RTCF_NOTIFY
)) ||
637 static int rt_may_expire(struct rtable
*rth
, unsigned long tmo1
, unsigned long tmo2
)
642 if (atomic_read(&rth
->u
.dst
.__refcnt
))
646 if (rth
->u
.dst
.expires
&&
647 time_after_eq(jiffies
, rth
->u
.dst
.expires
))
650 age
= jiffies
- rth
->u
.dst
.lastuse
;
652 if ((age
<= tmo1
&& !rt_fast_clean(rth
)) ||
653 (age
<= tmo2
&& rt_valuable(rth
)))
659 /* Bits of score are:
661 * 30: not quite useless
662 * 29..0: usage counter
664 static inline u32
rt_score(struct rtable
*rt
)
666 u32 score
= jiffies
- rt
->u
.dst
.lastuse
;
668 score
= ~score
& ~(3<<30);
674 !(rt
->rt_flags
& (RTCF_BROADCAST
|RTCF_MULTICAST
|RTCF_LOCAL
)))
680 static inline bool rt_caching(const struct net
*net
)
682 return net
->ipv4
.current_rt_cache_rebuild_count
<=
683 net
->ipv4
.sysctl_rt_cache_rebuild_count
;
686 static inline bool compare_hash_inputs(const struct flowi
*fl1
,
687 const struct flowi
*fl2
)
689 return (__force u32
)(((fl1
->nl_u
.ip4_u
.daddr
^ fl2
->nl_u
.ip4_u
.daddr
) |
690 (fl1
->nl_u
.ip4_u
.saddr
^ fl2
->nl_u
.ip4_u
.saddr
) |
691 (fl1
->iif
^ fl2
->iif
)) == 0);
694 static inline int compare_keys(struct flowi
*fl1
, struct flowi
*fl2
)
696 return ((__force u32
)((fl1
->nl_u
.ip4_u
.daddr
^ fl2
->nl_u
.ip4_u
.daddr
) |
697 (fl1
->nl_u
.ip4_u
.saddr
^ fl2
->nl_u
.ip4_u
.saddr
)) |
698 (fl1
->mark
^ fl2
->mark
) |
699 (*(u16
*)&fl1
->nl_u
.ip4_u
.tos
^
700 *(u16
*)&fl2
->nl_u
.ip4_u
.tos
) |
701 (fl1
->oif
^ fl2
->oif
) |
702 (fl1
->iif
^ fl2
->iif
)) == 0;
705 static inline int compare_netns(struct rtable
*rt1
, struct rtable
*rt2
)
707 return dev_net(rt1
->u
.dst
.dev
) == dev_net(rt2
->u
.dst
.dev
);
710 static inline int rt_is_expired(struct rtable
*rth
)
712 return rth
->rt_genid
!= rt_genid(dev_net(rth
->u
.dst
.dev
));
716 * Perform a full scan of hash table and free all entries.
717 * Can be called by a softirq or a process.
718 * In the later case, we want to be reschedule if necessary
720 static void rt_do_flush(int process_context
)
723 struct rtable
*rth
, *next
;
724 struct rtable
* tail
;
726 for (i
= 0; i
<= rt_hash_mask
; i
++) {
727 if (process_context
&& need_resched())
729 rth
= rt_hash_table
[i
].chain
;
733 spin_lock_bh(rt_hash_lock_addr(i
));
736 struct rtable
** prev
, * p
;
738 rth
= rt_hash_table
[i
].chain
;
740 /* defer releasing the head of the list after spin_unlock */
741 for (tail
= rth
; tail
; tail
= tail
->u
.dst
.rt_next
)
742 if (!rt_is_expired(tail
))
745 rt_hash_table
[i
].chain
= tail
;
747 /* call rt_free on entries after the tail requiring flush */
748 prev
= &rt_hash_table
[i
].chain
;
749 for (p
= *prev
; p
; p
= next
) {
750 next
= p
->u
.dst
.rt_next
;
751 if (!rt_is_expired(p
)) {
752 prev
= &p
->u
.dst
.rt_next
;
760 rth
= rt_hash_table
[i
].chain
;
761 rt_hash_table
[i
].chain
= NULL
;
764 spin_unlock_bh(rt_hash_lock_addr(i
));
766 for (; rth
!= tail
; rth
= next
) {
767 next
= rth
->u
.dst
.rt_next
;
774 * While freeing expired entries, we compute average chain length
775 * and standard deviation, using fixed-point arithmetic.
776 * This to have an estimation of rt_chain_length_max
777 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
778 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
782 #define ONE (1UL << FRACT_BITS)
784 static void rt_check_expire(void)
786 static unsigned int rover
;
787 unsigned int i
= rover
, goal
;
788 struct rtable
*rth
, **rthp
;
789 unsigned long length
= 0, samples
= 0;
790 unsigned long sum
= 0, sum2
= 0;
793 mult
= ((u64
)ip_rt_gc_interval
) << rt_hash_log
;
794 if (ip_rt_gc_timeout
> 1)
795 do_div(mult
, ip_rt_gc_timeout
);
796 goal
= (unsigned int)mult
;
797 if (goal
> rt_hash_mask
)
798 goal
= rt_hash_mask
+ 1;
800 for (; goal
> 0; goal
--) {
801 unsigned long tmo
= ip_rt_gc_timeout
;
803 i
= (i
+ 1) & rt_hash_mask
;
804 rthp
= &rt_hash_table
[i
].chain
;
813 spin_lock_bh(rt_hash_lock_addr(i
));
814 while ((rth
= *rthp
) != NULL
) {
815 if (rt_is_expired(rth
)) {
816 *rthp
= rth
->u
.dst
.rt_next
;
820 if (rth
->u
.dst
.expires
) {
821 /* Entry is expired even if it is in use */
822 if (time_before_eq(jiffies
, rth
->u
.dst
.expires
)) {
824 rthp
= &rth
->u
.dst
.rt_next
;
826 * Only bump our length if the hash
827 * inputs on entries n and n+1 are not
828 * the same, we only count entries on
829 * a chain with equal hash inputs once
830 * so that entries for different QOS
831 * levels, and other non-hash input
832 * attributes don't unfairly skew
833 * the length computation
835 if ((*rthp
== NULL
) ||
836 !compare_hash_inputs(&(*rthp
)->fl
,
841 } else if (!rt_may_expire(rth
, tmo
, ip_rt_gc_timeout
)) {
843 rthp
= &rth
->u
.dst
.rt_next
;
844 if ((*rthp
== NULL
) ||
845 !compare_hash_inputs(&(*rthp
)->fl
,
851 /* Cleanup aged off entries. */
852 *rthp
= rth
->u
.dst
.rt_next
;
855 spin_unlock_bh(rt_hash_lock_addr(i
));
857 sum2
+= length
*length
;
860 unsigned long avg
= sum
/ samples
;
861 unsigned long sd
= int_sqrt(sum2
/ samples
- avg
*avg
);
862 rt_chain_length_max
= max_t(unsigned long,
864 (avg
+ 4*sd
) >> FRACT_BITS
);
870 * rt_worker_func() is run in process context.
871 * we call rt_check_expire() to scan part of the hash table
873 static void rt_worker_func(struct work_struct
*work
)
876 schedule_delayed_work(&expires_work
, ip_rt_gc_interval
);
880 * Pertubation of rt_genid by a small quantity [1..256]
881 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
882 * many times (2^24) without giving recent rt_genid.
883 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
885 static void rt_cache_invalidate(struct net
*net
)
887 unsigned char shuffle
;
889 get_random_bytes(&shuffle
, sizeof(shuffle
));
890 atomic_add(shuffle
+ 1U, &net
->ipv4
.rt_genid
);
894 * delay < 0 : invalidate cache (fast : entries will be deleted later)
895 * delay >= 0 : invalidate & flush cache (can be long)
897 void rt_cache_flush(struct net
*net
, int delay
)
899 rt_cache_invalidate(net
);
901 rt_do_flush(!in_softirq());
905 * We change rt_genid and let gc do the cleanup
907 static void rt_secret_rebuild(unsigned long __net
)
909 struct net
*net
= (struct net
*)__net
;
910 rt_cache_invalidate(net
);
911 mod_timer(&net
->ipv4
.rt_secret_timer
, jiffies
+ ip_rt_secret_interval
);
914 static void rt_secret_rebuild_oneshot(struct net
*net
)
916 del_timer_sync(&net
->ipv4
.rt_secret_timer
);
917 rt_cache_invalidate(net
);
918 if (ip_rt_secret_interval
) {
919 net
->ipv4
.rt_secret_timer
.expires
+= ip_rt_secret_interval
;
920 add_timer(&net
->ipv4
.rt_secret_timer
);
924 static void rt_emergency_hash_rebuild(struct net
*net
)
926 if (net_ratelimit()) {
927 printk(KERN_WARNING
"Route hash chain too long!\n");
928 printk(KERN_WARNING
"Adjust your secret_interval!\n");
931 rt_secret_rebuild_oneshot(net
);
935 Short description of GC goals.
937 We want to build algorithm, which will keep routing cache
938 at some equilibrium point, when number of aged off entries
939 is kept approximately equal to newly generated ones.
941 Current expiration strength is variable "expire".
942 We try to adjust it dynamically, so that if networking
943 is idle expires is large enough to keep enough of warm entries,
944 and when load increases it reduces to limit cache size.
947 static int rt_garbage_collect(struct dst_ops
*ops
)
949 static unsigned long expire
= RT_GC_TIMEOUT
;
950 static unsigned long last_gc
;
952 static int equilibrium
;
953 struct rtable
*rth
, **rthp
;
954 unsigned long now
= jiffies
;
958 * Garbage collection is pretty expensive,
959 * do not make it too frequently.
962 RT_CACHE_STAT_INC(gc_total
);
964 if (now
- last_gc
< ip_rt_gc_min_interval
&&
965 atomic_read(&ipv4_dst_ops
.entries
) < ip_rt_max_size
) {
966 RT_CACHE_STAT_INC(gc_ignored
);
970 /* Calculate number of entries, which we want to expire now. */
971 goal
= atomic_read(&ipv4_dst_ops
.entries
) -
972 (ip_rt_gc_elasticity
<< rt_hash_log
);
974 if (equilibrium
< ipv4_dst_ops
.gc_thresh
)
975 equilibrium
= ipv4_dst_ops
.gc_thresh
;
976 goal
= atomic_read(&ipv4_dst_ops
.entries
) - equilibrium
;
978 equilibrium
+= min_t(unsigned int, goal
>> 1, rt_hash_mask
+ 1);
979 goal
= atomic_read(&ipv4_dst_ops
.entries
) - equilibrium
;
982 /* We are in dangerous area. Try to reduce cache really
985 goal
= max_t(unsigned int, goal
>> 1, rt_hash_mask
+ 1);
986 equilibrium
= atomic_read(&ipv4_dst_ops
.entries
) - goal
;
989 if (now
- last_gc
>= ip_rt_gc_min_interval
)
1000 for (i
= rt_hash_mask
, k
= rover
; i
>= 0; i
--) {
1001 unsigned long tmo
= expire
;
1003 k
= (k
+ 1) & rt_hash_mask
;
1004 rthp
= &rt_hash_table
[k
].chain
;
1005 spin_lock_bh(rt_hash_lock_addr(k
));
1006 while ((rth
= *rthp
) != NULL
) {
1007 if (!rt_is_expired(rth
) &&
1008 !rt_may_expire(rth
, tmo
, expire
)) {
1010 rthp
= &rth
->u
.dst
.rt_next
;
1013 *rthp
= rth
->u
.dst
.rt_next
;
1017 spin_unlock_bh(rt_hash_lock_addr(k
));
1026 /* Goal is not achieved. We stop process if:
1028 - if expire reduced to zero. Otherwise, expire is halfed.
1029 - if table is not full.
1030 - if we are called from interrupt.
1031 - jiffies check is just fallback/debug loop breaker.
1032 We will not spin here for long time in any case.
1035 RT_CACHE_STAT_INC(gc_goal_miss
);
1041 #if RT_CACHE_DEBUG >= 2
1042 printk(KERN_DEBUG
"expire>> %u %d %d %d\n", expire
,
1043 atomic_read(&ipv4_dst_ops
.entries
), goal
, i
);
1046 if (atomic_read(&ipv4_dst_ops
.entries
) < ip_rt_max_size
)
1048 } while (!in_softirq() && time_before_eq(jiffies
, now
));
1050 if (atomic_read(&ipv4_dst_ops
.entries
) < ip_rt_max_size
)
1052 if (net_ratelimit())
1053 printk(KERN_WARNING
"dst cache overflow\n");
1054 RT_CACHE_STAT_INC(gc_dst_overflow
);
1058 expire
+= ip_rt_gc_min_interval
;
1059 if (expire
> ip_rt_gc_timeout
||
1060 atomic_read(&ipv4_dst_ops
.entries
) < ipv4_dst_ops
.gc_thresh
)
1061 expire
= ip_rt_gc_timeout
;
1062 #if RT_CACHE_DEBUG >= 2
1063 printk(KERN_DEBUG
"expire++ %u %d %d %d\n", expire
,
1064 atomic_read(&ipv4_dst_ops
.entries
), goal
, rover
);
1069 static int rt_intern_hash(unsigned hash
, struct rtable
*rt
, struct rtable
**rp
)
1071 struct rtable
*rth
, **rthp
;
1072 struct rtable
*rthi
;
1074 struct rtable
*cand
, **candp
;
1077 int attempts
= !in_softirq();
1081 min_score
= ~(u32
)0;
1086 if (!rt_caching(dev_net(rt
->u
.dst
.dev
))) {
1091 rthp
= &rt_hash_table
[hash
].chain
;
1094 spin_lock_bh(rt_hash_lock_addr(hash
));
1095 while ((rth
= *rthp
) != NULL
) {
1096 if (rt_is_expired(rth
)) {
1097 *rthp
= rth
->u
.dst
.rt_next
;
1101 if (compare_keys(&rth
->fl
, &rt
->fl
) && compare_netns(rth
, rt
)) {
1103 *rthp
= rth
->u
.dst
.rt_next
;
1105 * Since lookup is lockfree, the deletion
1106 * must be visible to another weakly ordered CPU before
1107 * the insertion at the start of the hash chain.
1109 rcu_assign_pointer(rth
->u
.dst
.rt_next
,
1110 rt_hash_table
[hash
].chain
);
1112 * Since lookup is lockfree, the update writes
1113 * must be ordered for consistency on SMP.
1115 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rth
);
1117 dst_use(&rth
->u
.dst
, now
);
1118 spin_unlock_bh(rt_hash_lock_addr(hash
));
1125 if (!atomic_read(&rth
->u
.dst
.__refcnt
)) {
1126 u32 score
= rt_score(rth
);
1128 if (score
<= min_score
) {
1137 rthp
= &rth
->u
.dst
.rt_next
;
1140 * check to see if the next entry in the chain
1141 * contains the same hash input values as rt. If it does
1142 * This is where we will insert into the list, instead of
1143 * at the head. This groups entries that differ by aspects not
1144 * relvant to the hash function together, which we use to adjust
1147 if (*rthp
&& compare_hash_inputs(&(*rthp
)->fl
, &rt
->fl
))
1152 /* ip_rt_gc_elasticity used to be average length of chain
1153 * length, when exceeded gc becomes really aggressive.
1155 * The second limit is less certain. At the moment it allows
1156 * only 2 entries per bucket. We will see.
1158 if (chain_length
> ip_rt_gc_elasticity
) {
1159 *candp
= cand
->u
.dst
.rt_next
;
1163 if (chain_length
> rt_chain_length_max
) {
1164 struct net
*net
= dev_net(rt
->u
.dst
.dev
);
1165 int num
= ++net
->ipv4
.current_rt_cache_rebuild_count
;
1166 if (!rt_caching(dev_net(rt
->u
.dst
.dev
))) {
1167 printk(KERN_WARNING
"%s: %d rebuilds is over limit, route caching disabled\n",
1168 rt
->u
.dst
.dev
->name
, num
);
1170 rt_emergency_hash_rebuild(dev_net(rt
->u
.dst
.dev
));
1174 /* Try to bind route to arp only if it is output
1175 route or unicast forwarding path.
1177 if (rt
->rt_type
== RTN_UNICAST
|| rt
->fl
.iif
== 0) {
1178 int err
= arp_bind_neighbour(&rt
->u
.dst
);
1180 spin_unlock_bh(rt_hash_lock_addr(hash
));
1182 if (err
!= -ENOBUFS
) {
1187 /* Neighbour tables are full and nothing
1188 can be released. Try to shrink route cache,
1189 it is most likely it holds some neighbour records.
1191 if (attempts
-- > 0) {
1192 int saved_elasticity
= ip_rt_gc_elasticity
;
1193 int saved_int
= ip_rt_gc_min_interval
;
1194 ip_rt_gc_elasticity
= 1;
1195 ip_rt_gc_min_interval
= 0;
1196 rt_garbage_collect(&ipv4_dst_ops
);
1197 ip_rt_gc_min_interval
= saved_int
;
1198 ip_rt_gc_elasticity
= saved_elasticity
;
1202 if (net_ratelimit())
1203 printk(KERN_WARNING
"Neighbour table overflow.\n");
1210 rt
->u
.dst
.rt_next
= rthi
->u
.dst
.rt_next
;
1212 rt
->u
.dst
.rt_next
= rt_hash_table
[hash
].chain
;
1214 #if RT_CACHE_DEBUG >= 2
1215 if (rt
->u
.dst
.rt_next
) {
1217 printk(KERN_DEBUG
"rt_cache @%02x: %pI4", hash
, &rt
->rt_dst
);
1218 for (trt
= rt
->u
.dst
.rt_next
; trt
; trt
= trt
->u
.dst
.rt_next
)
1219 printk(" . %pI4", &trt
->rt_dst
);
1224 * Since lookup is lockfree, we must make sure
1225 * previous writes to rt are comitted to memory
1226 * before making rt visible to other CPUS.
1229 rcu_assign_pointer(rthi
->u
.dst
.rt_next
, rt
);
1231 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rt
);
1233 spin_unlock_bh(rt_hash_lock_addr(hash
));
1238 void rt_bind_peer(struct rtable
*rt
, int create
)
1240 static DEFINE_SPINLOCK(rt_peer_lock
);
1241 struct inet_peer
*peer
;
1243 peer
= inet_getpeer(rt
->rt_dst
, create
);
1245 spin_lock_bh(&rt_peer_lock
);
1246 if (rt
->peer
== NULL
) {
1250 spin_unlock_bh(&rt_peer_lock
);
1256 * Peer allocation may fail only in serious out-of-memory conditions. However
1257 * we still can generate some output.
1258 * Random ID selection looks a bit dangerous because we have no chances to
1259 * select ID being unique in a reasonable period of time.
1260 * But broken packet identifier may be better than no packet at all.
1262 static void ip_select_fb_ident(struct iphdr
*iph
)
1264 static DEFINE_SPINLOCK(ip_fb_id_lock
);
1265 static u32 ip_fallback_id
;
1268 spin_lock_bh(&ip_fb_id_lock
);
1269 salt
= secure_ip_id((__force __be32
)ip_fallback_id
^ iph
->daddr
);
1270 iph
->id
= htons(salt
& 0xFFFF);
1271 ip_fallback_id
= salt
;
1272 spin_unlock_bh(&ip_fb_id_lock
);
1275 void __ip_select_ident(struct iphdr
*iph
, struct dst_entry
*dst
, int more
)
1277 struct rtable
*rt
= (struct rtable
*) dst
;
1280 if (rt
->peer
== NULL
)
1281 rt_bind_peer(rt
, 1);
1283 /* If peer is attached to destination, it is never detached,
1284 so that we need not to grab a lock to dereference it.
1287 iph
->id
= htons(inet_getid(rt
->peer
, more
));
1291 printk(KERN_DEBUG
"rt_bind_peer(0) @%p\n",
1292 __builtin_return_address(0));
1294 ip_select_fb_ident(iph
);
1297 static void rt_del(unsigned hash
, struct rtable
*rt
)
1299 struct rtable
**rthp
, *aux
;
1301 rthp
= &rt_hash_table
[hash
].chain
;
1302 spin_lock_bh(rt_hash_lock_addr(hash
));
1304 while ((aux
= *rthp
) != NULL
) {
1305 if (aux
== rt
|| rt_is_expired(aux
)) {
1306 *rthp
= aux
->u
.dst
.rt_next
;
1310 rthp
= &aux
->u
.dst
.rt_next
;
1312 spin_unlock_bh(rt_hash_lock_addr(hash
));
1315 void ip_rt_redirect(__be32 old_gw
, __be32 daddr
, __be32 new_gw
,
1316 __be32 saddr
, struct net_device
*dev
)
1319 struct in_device
*in_dev
= in_dev_get(dev
);
1320 struct rtable
*rth
, **rthp
;
1321 __be32 skeys
[2] = { saddr
, 0 };
1322 int ikeys
[2] = { dev
->ifindex
, 0 };
1323 struct netevent_redirect netevent
;
1330 if (new_gw
== old_gw
|| !IN_DEV_RX_REDIRECTS(in_dev
)
1331 || ipv4_is_multicast(new_gw
) || ipv4_is_lbcast(new_gw
)
1332 || ipv4_is_zeronet(new_gw
))
1333 goto reject_redirect
;
1335 if (!rt_caching(net
))
1336 goto reject_redirect
;
1338 if (!IN_DEV_SHARED_MEDIA(in_dev
)) {
1339 if (!inet_addr_onlink(in_dev
, new_gw
, old_gw
))
1340 goto reject_redirect
;
1341 if (IN_DEV_SEC_REDIRECTS(in_dev
) && ip_fib_check_default(new_gw
, dev
))
1342 goto reject_redirect
;
1344 if (inet_addr_type(net
, new_gw
) != RTN_UNICAST
)
1345 goto reject_redirect
;
1348 for (i
= 0; i
< 2; i
++) {
1349 for (k
= 0; k
< 2; k
++) {
1350 unsigned hash
= rt_hash(daddr
, skeys
[i
], ikeys
[k
],
1353 rthp
=&rt_hash_table
[hash
].chain
;
1356 while ((rth
= rcu_dereference(*rthp
)) != NULL
) {
1359 if (rth
->fl
.fl4_dst
!= daddr
||
1360 rth
->fl
.fl4_src
!= skeys
[i
] ||
1361 rth
->fl
.oif
!= ikeys
[k
] ||
1363 rt_is_expired(rth
) ||
1364 !net_eq(dev_net(rth
->u
.dst
.dev
), net
)) {
1365 rthp
= &rth
->u
.dst
.rt_next
;
1369 if (rth
->rt_dst
!= daddr
||
1370 rth
->rt_src
!= saddr
||
1372 rth
->rt_gateway
!= old_gw
||
1373 rth
->u
.dst
.dev
!= dev
)
1376 dst_hold(&rth
->u
.dst
);
1379 rt
= dst_alloc(&ipv4_dst_ops
);
1386 /* Copy all the information. */
1388 rt
->u
.dst
.__use
= 1;
1389 atomic_set(&rt
->u
.dst
.__refcnt
, 1);
1390 rt
->u
.dst
.child
= NULL
;
1392 dev_hold(rt
->u
.dst
.dev
);
1394 in_dev_hold(rt
->idev
);
1395 rt
->u
.dst
.obsolete
= 0;
1396 rt
->u
.dst
.lastuse
= jiffies
;
1397 rt
->u
.dst
.path
= &rt
->u
.dst
;
1398 rt
->u
.dst
.neighbour
= NULL
;
1399 rt
->u
.dst
.hh
= NULL
;
1401 rt
->u
.dst
.xfrm
= NULL
;
1403 rt
->rt_genid
= rt_genid(net
);
1404 rt
->rt_flags
|= RTCF_REDIRECTED
;
1406 /* Gateway is different ... */
1407 rt
->rt_gateway
= new_gw
;
1409 /* Redirect received -> path was valid */
1410 dst_confirm(&rth
->u
.dst
);
1413 atomic_inc(&rt
->peer
->refcnt
);
1415 if (arp_bind_neighbour(&rt
->u
.dst
) ||
1416 !(rt
->u
.dst
.neighbour
->nud_state
&
1418 if (rt
->u
.dst
.neighbour
)
1419 neigh_event_send(rt
->u
.dst
.neighbour
, NULL
);
1425 netevent
.old
= &rth
->u
.dst
;
1426 netevent
.new = &rt
->u
.dst
;
1427 call_netevent_notifiers(NETEVENT_REDIRECT
,
1431 if (!rt_intern_hash(hash
, rt
, &rt
))
1444 #ifdef CONFIG_IP_ROUTE_VERBOSE
1445 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit())
1446 printk(KERN_INFO
"Redirect from %pI4 on %s about %pI4 ignored.\n"
1447 " Advised path = %pI4 -> %pI4\n",
1448 &old_gw
, dev
->name
, &new_gw
,
1454 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
)
1456 struct rtable
*rt
= (struct rtable
*)dst
;
1457 struct dst_entry
*ret
= dst
;
1460 if (dst
->obsolete
) {
1463 } else if ((rt
->rt_flags
& RTCF_REDIRECTED
) ||
1464 rt
->u
.dst
.expires
) {
1465 unsigned hash
= rt_hash(rt
->fl
.fl4_dst
, rt
->fl
.fl4_src
,
1467 rt_genid(dev_net(dst
->dev
)));
1468 #if RT_CACHE_DEBUG >= 1
1469 printk(KERN_DEBUG
"ipv4_negative_advice: redirect to %pI4/%02x dropped\n",
1470 &rt
->rt_dst
, rt
->fl
.fl4_tos
);
1481 * 1. The first ip_rt_redirect_number redirects are sent
1482 * with exponential backoff, then we stop sending them at all,
1483 * assuming that the host ignores our redirects.
1484 * 2. If we did not see packets requiring redirects
1485 * during ip_rt_redirect_silence, we assume that the host
1486 * forgot redirected route and start to send redirects again.
1488 * This algorithm is much cheaper and more intelligent than dumb load limiting
1491 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1492 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1495 void ip_rt_send_redirect(struct sk_buff
*skb
)
1497 struct rtable
*rt
= skb
->rtable
;
1498 struct in_device
*in_dev
= in_dev_get(rt
->u
.dst
.dev
);
1503 if (!IN_DEV_TX_REDIRECTS(in_dev
))
1506 /* No redirected packets during ip_rt_redirect_silence;
1507 * reset the algorithm.
1509 if (time_after(jiffies
, rt
->u
.dst
.rate_last
+ ip_rt_redirect_silence
))
1510 rt
->u
.dst
.rate_tokens
= 0;
1512 /* Too many ignored redirects; do not send anything
1513 * set u.dst.rate_last to the last seen redirected packet.
1515 if (rt
->u
.dst
.rate_tokens
>= ip_rt_redirect_number
) {
1516 rt
->u
.dst
.rate_last
= jiffies
;
1520 /* Check for load limit; set rate_last to the latest sent
1523 if (rt
->u
.dst
.rate_tokens
== 0 ||
1525 (rt
->u
.dst
.rate_last
+
1526 (ip_rt_redirect_load
<< rt
->u
.dst
.rate_tokens
)))) {
1527 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, rt
->rt_gateway
);
1528 rt
->u
.dst
.rate_last
= jiffies
;
1529 ++rt
->u
.dst
.rate_tokens
;
1530 #ifdef CONFIG_IP_ROUTE_VERBOSE
1531 if (IN_DEV_LOG_MARTIANS(in_dev
) &&
1532 rt
->u
.dst
.rate_tokens
== ip_rt_redirect_number
&&
1534 printk(KERN_WARNING
"host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1535 &rt
->rt_src
, rt
->rt_iif
,
1536 &rt
->rt_dst
, &rt
->rt_gateway
);
1543 static int ip_error(struct sk_buff
*skb
)
1545 struct rtable
*rt
= skb
->rtable
;
1549 switch (rt
->u
.dst
.error
) {
1554 code
= ICMP_HOST_UNREACH
;
1557 code
= ICMP_NET_UNREACH
;
1558 IP_INC_STATS_BH(dev_net(rt
->u
.dst
.dev
),
1559 IPSTATS_MIB_INNOROUTES
);
1562 code
= ICMP_PKT_FILTERED
;
1567 rt
->u
.dst
.rate_tokens
+= now
- rt
->u
.dst
.rate_last
;
1568 if (rt
->u
.dst
.rate_tokens
> ip_rt_error_burst
)
1569 rt
->u
.dst
.rate_tokens
= ip_rt_error_burst
;
1570 rt
->u
.dst
.rate_last
= now
;
1571 if (rt
->u
.dst
.rate_tokens
>= ip_rt_error_cost
) {
1572 rt
->u
.dst
.rate_tokens
-= ip_rt_error_cost
;
1573 icmp_send(skb
, ICMP_DEST_UNREACH
, code
, 0);
1576 out
: kfree_skb(skb
);
1581 * The last two values are not from the RFC but
1582 * are needed for AMPRnet AX.25 paths.
1585 static const unsigned short mtu_plateau
[] =
1586 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1588 static inline unsigned short guess_mtu(unsigned short old_mtu
)
1592 for (i
= 0; i
< ARRAY_SIZE(mtu_plateau
); i
++)
1593 if (old_mtu
> mtu_plateau
[i
])
1594 return mtu_plateau
[i
];
1598 unsigned short ip_rt_frag_needed(struct net
*net
, struct iphdr
*iph
,
1599 unsigned short new_mtu
,
1600 struct net_device
*dev
)
1603 unsigned short old_mtu
= ntohs(iph
->tot_len
);
1605 int ikeys
[2] = { dev
->ifindex
, 0 };
1606 __be32 skeys
[2] = { iph
->saddr
, 0, };
1607 __be32 daddr
= iph
->daddr
;
1608 unsigned short est_mtu
= 0;
1610 if (ipv4_config
.no_pmtu_disc
)
1613 for (k
= 0; k
< 2; k
++) {
1614 for (i
= 0; i
< 2; i
++) {
1615 unsigned hash
= rt_hash(daddr
, skeys
[i
], ikeys
[k
],
1619 for (rth
= rcu_dereference(rt_hash_table
[hash
].chain
); rth
;
1620 rth
= rcu_dereference(rth
->u
.dst
.rt_next
)) {
1621 unsigned short mtu
= new_mtu
;
1623 if (rth
->fl
.fl4_dst
!= daddr
||
1624 rth
->fl
.fl4_src
!= skeys
[i
] ||
1625 rth
->rt_dst
!= daddr
||
1626 rth
->rt_src
!= iph
->saddr
||
1627 rth
->fl
.oif
!= ikeys
[k
] ||
1629 dst_metric_locked(&rth
->u
.dst
, RTAX_MTU
) ||
1630 !net_eq(dev_net(rth
->u
.dst
.dev
), net
) ||
1634 if (new_mtu
< 68 || new_mtu
>= old_mtu
) {
1636 /* BSD 4.2 compatibility hack :-( */
1638 old_mtu
>= dst_mtu(&rth
->u
.dst
) &&
1639 old_mtu
>= 68 + (iph
->ihl
<< 2))
1640 old_mtu
-= iph
->ihl
<< 2;
1642 mtu
= guess_mtu(old_mtu
);
1644 if (mtu
<= dst_mtu(&rth
->u
.dst
)) {
1645 if (mtu
< dst_mtu(&rth
->u
.dst
)) {
1646 dst_confirm(&rth
->u
.dst
);
1647 if (mtu
< ip_rt_min_pmtu
) {
1648 mtu
= ip_rt_min_pmtu
;
1649 rth
->u
.dst
.metrics
[RTAX_LOCK
-1] |=
1652 rth
->u
.dst
.metrics
[RTAX_MTU
-1] = mtu
;
1653 dst_set_expires(&rth
->u
.dst
,
1662 return est_mtu
? : new_mtu
;
1665 static void ip_rt_update_pmtu(struct dst_entry
*dst
, u32 mtu
)
1667 if (dst_mtu(dst
) > mtu
&& mtu
>= 68 &&
1668 !(dst_metric_locked(dst
, RTAX_MTU
))) {
1669 if (mtu
< ip_rt_min_pmtu
) {
1670 mtu
= ip_rt_min_pmtu
;
1671 dst
->metrics
[RTAX_LOCK
-1] |= (1 << RTAX_MTU
);
1673 dst
->metrics
[RTAX_MTU
-1] = mtu
;
1674 dst_set_expires(dst
, ip_rt_mtu_expires
);
1675 call_netevent_notifiers(NETEVENT_PMTU_UPDATE
, dst
);
1679 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
)
1684 static void ipv4_dst_destroy(struct dst_entry
*dst
)
1686 struct rtable
*rt
= (struct rtable
*) dst
;
1687 struct inet_peer
*peer
= rt
->peer
;
1688 struct in_device
*idev
= rt
->idev
;
1701 static void ipv4_dst_ifdown(struct dst_entry
*dst
, struct net_device
*dev
,
1704 struct rtable
*rt
= (struct rtable
*) dst
;
1705 struct in_device
*idev
= rt
->idev
;
1706 if (dev
!= dev_net(dev
)->loopback_dev
&& idev
&& idev
->dev
== dev
) {
1707 struct in_device
*loopback_idev
=
1708 in_dev_get(dev_net(dev
)->loopback_dev
);
1709 if (loopback_idev
) {
1710 rt
->idev
= loopback_idev
;
1716 static void ipv4_link_failure(struct sk_buff
*skb
)
1720 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_HOST_UNREACH
, 0);
1724 dst_set_expires(&rt
->u
.dst
, 0);
1727 static int ip_rt_bug(struct sk_buff
*skb
)
1729 printk(KERN_DEBUG
"ip_rt_bug: %pI4 -> %pI4, %s\n",
1730 &ip_hdr(skb
)->saddr
, &ip_hdr(skb
)->daddr
,
1731 skb
->dev
? skb
->dev
->name
: "?");
1737 We do not cache source address of outgoing interface,
1738 because it is used only by IP RR, TS and SRR options,
1739 so that it out of fast path.
1741 BTW remember: "addr" is allowed to be not aligned
1745 void ip_rt_get_source(u8
*addr
, struct rtable
*rt
)
1748 struct fib_result res
;
1750 if (rt
->fl
.iif
== 0)
1752 else if (fib_lookup(dev_net(rt
->u
.dst
.dev
), &rt
->fl
, &res
) == 0) {
1753 src
= FIB_RES_PREFSRC(res
);
1756 src
= inet_select_addr(rt
->u
.dst
.dev
, rt
->rt_gateway
,
1758 memcpy(addr
, &src
, 4);
1761 #ifdef CONFIG_NET_CLS_ROUTE
1762 static void set_class_tag(struct rtable
*rt
, u32 tag
)
1764 if (!(rt
->u
.dst
.tclassid
& 0xFFFF))
1765 rt
->u
.dst
.tclassid
|= tag
& 0xFFFF;
1766 if (!(rt
->u
.dst
.tclassid
& 0xFFFF0000))
1767 rt
->u
.dst
.tclassid
|= tag
& 0xFFFF0000;
1771 static void rt_set_nexthop(struct rtable
*rt
, struct fib_result
*res
, u32 itag
)
1773 struct fib_info
*fi
= res
->fi
;
1776 if (FIB_RES_GW(*res
) &&
1777 FIB_RES_NH(*res
).nh_scope
== RT_SCOPE_LINK
)
1778 rt
->rt_gateway
= FIB_RES_GW(*res
);
1779 memcpy(rt
->u
.dst
.metrics
, fi
->fib_metrics
,
1780 sizeof(rt
->u
.dst
.metrics
));
1781 if (fi
->fib_mtu
== 0) {
1782 rt
->u
.dst
.metrics
[RTAX_MTU
-1] = rt
->u
.dst
.dev
->mtu
;
1783 if (dst_metric_locked(&rt
->u
.dst
, RTAX_MTU
) &&
1784 rt
->rt_gateway
!= rt
->rt_dst
&&
1785 rt
->u
.dst
.dev
->mtu
> 576)
1786 rt
->u
.dst
.metrics
[RTAX_MTU
-1] = 576;
1788 #ifdef CONFIG_NET_CLS_ROUTE
1789 rt
->u
.dst
.tclassid
= FIB_RES_NH(*res
).nh_tclassid
;
1792 rt
->u
.dst
.metrics
[RTAX_MTU
-1]= rt
->u
.dst
.dev
->mtu
;
1794 if (dst_metric(&rt
->u
.dst
, RTAX_HOPLIMIT
) == 0)
1795 rt
->u
.dst
.metrics
[RTAX_HOPLIMIT
-1] = sysctl_ip_default_ttl
;
1796 if (dst_mtu(&rt
->u
.dst
) > IP_MAX_MTU
)
1797 rt
->u
.dst
.metrics
[RTAX_MTU
-1] = IP_MAX_MTU
;
1798 if (dst_metric(&rt
->u
.dst
, RTAX_ADVMSS
) == 0)
1799 rt
->u
.dst
.metrics
[RTAX_ADVMSS
-1] = max_t(unsigned int, rt
->u
.dst
.dev
->mtu
- 40,
1801 if (dst_metric(&rt
->u
.dst
, RTAX_ADVMSS
) > 65535 - 40)
1802 rt
->u
.dst
.metrics
[RTAX_ADVMSS
-1] = 65535 - 40;
1804 #ifdef CONFIG_NET_CLS_ROUTE
1805 #ifdef CONFIG_IP_MULTIPLE_TABLES
1806 set_class_tag(rt
, fib_rules_tclass(res
));
1808 set_class_tag(rt
, itag
);
1810 rt
->rt_type
= res
->type
;
1813 static int ip_route_input_mc(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
1814 u8 tos
, struct net_device
*dev
, int our
)
1819 struct in_device
*in_dev
= in_dev_get(dev
);
1822 /* Primary sanity checks. */
1827 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
) ||
1828 ipv4_is_loopback(saddr
) || skb
->protocol
!= htons(ETH_P_IP
))
1831 if (ipv4_is_zeronet(saddr
)) {
1832 if (!ipv4_is_local_multicast(daddr
))
1834 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_LINK
);
1835 } else if (fib_validate_source(saddr
, 0, tos
, 0,
1836 dev
, &spec_dst
, &itag
) < 0)
1839 rth
= dst_alloc(&ipv4_dst_ops
);
1843 rth
->u
.dst
.output
= ip_rt_bug
;
1845 atomic_set(&rth
->u
.dst
.__refcnt
, 1);
1846 rth
->u
.dst
.flags
= DST_HOST
;
1847 if (IN_DEV_CONF_GET(in_dev
, NOPOLICY
))
1848 rth
->u
.dst
.flags
|= DST_NOPOLICY
;
1849 rth
->fl
.fl4_dst
= daddr
;
1850 rth
->rt_dst
= daddr
;
1851 rth
->fl
.fl4_tos
= tos
;
1852 rth
->fl
.mark
= skb
->mark
;
1853 rth
->fl
.fl4_src
= saddr
;
1854 rth
->rt_src
= saddr
;
1855 #ifdef CONFIG_NET_CLS_ROUTE
1856 rth
->u
.dst
.tclassid
= itag
;
1859 rth
->fl
.iif
= dev
->ifindex
;
1860 rth
->u
.dst
.dev
= init_net
.loopback_dev
;
1861 dev_hold(rth
->u
.dst
.dev
);
1862 rth
->idev
= in_dev_get(rth
->u
.dst
.dev
);
1864 rth
->rt_gateway
= daddr
;
1865 rth
->rt_spec_dst
= spec_dst
;
1866 rth
->rt_genid
= rt_genid(dev_net(dev
));
1867 rth
->rt_flags
= RTCF_MULTICAST
;
1868 rth
->rt_type
= RTN_MULTICAST
;
1870 rth
->u
.dst
.input
= ip_local_deliver
;
1871 rth
->rt_flags
|= RTCF_LOCAL
;
1874 #ifdef CONFIG_IP_MROUTE
1875 if (!ipv4_is_local_multicast(daddr
) && IN_DEV_MFORWARD(in_dev
))
1876 rth
->u
.dst
.input
= ip_mr_input
;
1878 RT_CACHE_STAT_INC(in_slow_mc
);
1881 hash
= rt_hash(daddr
, saddr
, dev
->ifindex
, rt_genid(dev_net(dev
)));
1882 return rt_intern_hash(hash
, rth
, &skb
->rtable
);
1894 static void ip_handle_martian_source(struct net_device
*dev
,
1895 struct in_device
*in_dev
,
1896 struct sk_buff
*skb
,
1900 RT_CACHE_STAT_INC(in_martian_src
);
1901 #ifdef CONFIG_IP_ROUTE_VERBOSE
1902 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit()) {
1904 * RFC1812 recommendation, if source is martian,
1905 * the only hint is MAC header.
1907 printk(KERN_WARNING
"martian source %pI4 from %pI4, on dev %s\n",
1908 &daddr
, &saddr
, dev
->name
);
1909 if (dev
->hard_header_len
&& skb_mac_header_was_set(skb
)) {
1911 const unsigned char *p
= skb_mac_header(skb
);
1912 printk(KERN_WARNING
"ll header: ");
1913 for (i
= 0; i
< dev
->hard_header_len
; i
++, p
++) {
1915 if (i
< (dev
->hard_header_len
- 1))
1924 static int __mkroute_input(struct sk_buff
*skb
,
1925 struct fib_result
*res
,
1926 struct in_device
*in_dev
,
1927 __be32 daddr
, __be32 saddr
, u32 tos
,
1928 struct rtable
**result
)
1933 struct in_device
*out_dev
;
1938 /* get a working reference to the output device */
1939 out_dev
= in_dev_get(FIB_RES_DEV(*res
));
1940 if (out_dev
== NULL
) {
1941 if (net_ratelimit())
1942 printk(KERN_CRIT
"Bug in ip_route_input" \
1943 "_slow(). Please, report\n");
1948 err
= fib_validate_source(saddr
, daddr
, tos
, FIB_RES_OIF(*res
),
1949 in_dev
->dev
, &spec_dst
, &itag
);
1951 ip_handle_martian_source(in_dev
->dev
, in_dev
, skb
, daddr
,
1959 flags
|= RTCF_DIRECTSRC
;
1961 if (out_dev
== in_dev
&& err
&&
1962 (IN_DEV_SHARED_MEDIA(out_dev
) ||
1963 inet_addr_onlink(out_dev
, saddr
, FIB_RES_GW(*res
))))
1964 flags
|= RTCF_DOREDIRECT
;
1966 if (skb
->protocol
!= htons(ETH_P_IP
)) {
1967 /* Not IP (i.e. ARP). Do not create route, if it is
1968 * invalid for proxy arp. DNAT routes are always valid.
1970 if (out_dev
== in_dev
) {
1977 rth
= dst_alloc(&ipv4_dst_ops
);
1983 atomic_set(&rth
->u
.dst
.__refcnt
, 1);
1984 rth
->u
.dst
.flags
= DST_HOST
;
1985 if (IN_DEV_CONF_GET(in_dev
, NOPOLICY
))
1986 rth
->u
.dst
.flags
|= DST_NOPOLICY
;
1987 if (IN_DEV_CONF_GET(out_dev
, NOXFRM
))
1988 rth
->u
.dst
.flags
|= DST_NOXFRM
;
1989 rth
->fl
.fl4_dst
= daddr
;
1990 rth
->rt_dst
= daddr
;
1991 rth
->fl
.fl4_tos
= tos
;
1992 rth
->fl
.mark
= skb
->mark
;
1993 rth
->fl
.fl4_src
= saddr
;
1994 rth
->rt_src
= saddr
;
1995 rth
->rt_gateway
= daddr
;
1997 rth
->fl
.iif
= in_dev
->dev
->ifindex
;
1998 rth
->u
.dst
.dev
= (out_dev
)->dev
;
1999 dev_hold(rth
->u
.dst
.dev
);
2000 rth
->idev
= in_dev_get(rth
->u
.dst
.dev
);
2002 rth
->rt_spec_dst
= spec_dst
;
2004 rth
->u
.dst
.input
= ip_forward
;
2005 rth
->u
.dst
.output
= ip_output
;
2006 rth
->rt_genid
= rt_genid(dev_net(rth
->u
.dst
.dev
));
2008 rt_set_nexthop(rth
, res
, itag
);
2010 rth
->rt_flags
= flags
;
2015 /* release the working reference to the output device */
2016 in_dev_put(out_dev
);
2020 static int ip_mkroute_input(struct sk_buff
*skb
,
2021 struct fib_result
*res
,
2022 const struct flowi
*fl
,
2023 struct in_device
*in_dev
,
2024 __be32 daddr
, __be32 saddr
, u32 tos
)
2026 struct rtable
* rth
= NULL
;
2030 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2031 if (res
->fi
&& res
->fi
->fib_nhs
> 1 && fl
->oif
== 0)
2032 fib_select_multipath(fl
, res
);
2035 /* create a routing cache entry */
2036 err
= __mkroute_input(skb
, res
, in_dev
, daddr
, saddr
, tos
, &rth
);
2040 /* put it into the cache */
2041 hash
= rt_hash(daddr
, saddr
, fl
->iif
,
2042 rt_genid(dev_net(rth
->u
.dst
.dev
)));
2043 return rt_intern_hash(hash
, rth
, &skb
->rtable
);
2047 * NOTE. We drop all the packets that has local source
2048 * addresses, because every properly looped back packet
2049 * must have correct destination already attached by output routine.
2051 * Such approach solves two big problems:
2052 * 1. Not simplex devices are handled properly.
2053 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2056 static int ip_route_input_slow(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2057 u8 tos
, struct net_device
*dev
)
2059 struct fib_result res
;
2060 struct in_device
*in_dev
= in_dev_get(dev
);
2061 struct flowi fl
= { .nl_u
= { .ip4_u
=
2065 .scope
= RT_SCOPE_UNIVERSE
,
2068 .iif
= dev
->ifindex
};
2071 struct rtable
* rth
;
2076 struct net
* net
= dev_net(dev
);
2078 /* IP on this device is disabled. */
2083 /* Check for the most weird martians, which can be not detected
2087 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
) ||
2088 ipv4_is_loopback(saddr
))
2089 goto martian_source
;
2091 if (daddr
== htonl(0xFFFFFFFF) || (saddr
== 0 && daddr
== 0))
2094 /* Accept zero addresses only to limited broadcast;
2095 * I even do not know to fix it or not. Waiting for complains :-)
2097 if (ipv4_is_zeronet(saddr
))
2098 goto martian_source
;
2100 if (ipv4_is_lbcast(daddr
) || ipv4_is_zeronet(daddr
) ||
2101 ipv4_is_loopback(daddr
))
2102 goto martian_destination
;
2105 * Now we are ready to route packet.
2107 if ((err
= fib_lookup(net
, &fl
, &res
)) != 0) {
2108 if (!IN_DEV_FORWARD(in_dev
))
2114 RT_CACHE_STAT_INC(in_slow_tot
);
2116 if (res
.type
== RTN_BROADCAST
)
2119 if (res
.type
== RTN_LOCAL
) {
2121 result
= fib_validate_source(saddr
, daddr
, tos
,
2122 net
->loopback_dev
->ifindex
,
2123 dev
, &spec_dst
, &itag
);
2125 goto martian_source
;
2127 flags
|= RTCF_DIRECTSRC
;
2132 if (!IN_DEV_FORWARD(in_dev
))
2134 if (res
.type
!= RTN_UNICAST
)
2135 goto martian_destination
;
2137 err
= ip_mkroute_input(skb
, &res
, &fl
, in_dev
, daddr
, saddr
, tos
);
2145 if (skb
->protocol
!= htons(ETH_P_IP
))
2148 if (ipv4_is_zeronet(saddr
))
2149 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_LINK
);
2151 err
= fib_validate_source(saddr
, 0, tos
, 0, dev
, &spec_dst
,
2154 goto martian_source
;
2156 flags
|= RTCF_DIRECTSRC
;
2158 flags
|= RTCF_BROADCAST
;
2159 res
.type
= RTN_BROADCAST
;
2160 RT_CACHE_STAT_INC(in_brd
);
2163 rth
= dst_alloc(&ipv4_dst_ops
);
2167 rth
->u
.dst
.output
= ip_rt_bug
;
2168 rth
->rt_genid
= rt_genid(net
);
2170 atomic_set(&rth
->u
.dst
.__refcnt
, 1);
2171 rth
->u
.dst
.flags
= DST_HOST
;
2172 if (IN_DEV_CONF_GET(in_dev
, NOPOLICY
))
2173 rth
->u
.dst
.flags
|= DST_NOPOLICY
;
2174 rth
->fl
.fl4_dst
= daddr
;
2175 rth
->rt_dst
= daddr
;
2176 rth
->fl
.fl4_tos
= tos
;
2177 rth
->fl
.mark
= skb
->mark
;
2178 rth
->fl
.fl4_src
= saddr
;
2179 rth
->rt_src
= saddr
;
2180 #ifdef CONFIG_NET_CLS_ROUTE
2181 rth
->u
.dst
.tclassid
= itag
;
2184 rth
->fl
.iif
= dev
->ifindex
;
2185 rth
->u
.dst
.dev
= net
->loopback_dev
;
2186 dev_hold(rth
->u
.dst
.dev
);
2187 rth
->idev
= in_dev_get(rth
->u
.dst
.dev
);
2188 rth
->rt_gateway
= daddr
;
2189 rth
->rt_spec_dst
= spec_dst
;
2190 rth
->u
.dst
.input
= ip_local_deliver
;
2191 rth
->rt_flags
= flags
|RTCF_LOCAL
;
2192 if (res
.type
== RTN_UNREACHABLE
) {
2193 rth
->u
.dst
.input
= ip_error
;
2194 rth
->u
.dst
.error
= -err
;
2195 rth
->rt_flags
&= ~RTCF_LOCAL
;
2197 rth
->rt_type
= res
.type
;
2198 hash
= rt_hash(daddr
, saddr
, fl
.iif
, rt_genid(net
));
2199 err
= rt_intern_hash(hash
, rth
, &skb
->rtable
);
2203 RT_CACHE_STAT_INC(in_no_route
);
2204 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_UNIVERSE
);
2205 res
.type
= RTN_UNREACHABLE
;
2211 * Do not cache martian addresses: they should be logged (RFC1812)
2213 martian_destination
:
2214 RT_CACHE_STAT_INC(in_martian_dst
);
2215 #ifdef CONFIG_IP_ROUTE_VERBOSE
2216 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit())
2217 printk(KERN_WARNING
"martian destination %pI4 from %pI4, dev %s\n",
2218 &daddr
, &saddr
, dev
->name
);
2222 err
= -EHOSTUNREACH
;
2234 ip_handle_martian_source(dev
, in_dev
, skb
, daddr
, saddr
);
2238 int ip_route_input(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2239 u8 tos
, struct net_device
*dev
)
2241 struct rtable
* rth
;
2243 int iif
= dev
->ifindex
;
2248 if (!rt_caching(net
))
2251 tos
&= IPTOS_RT_MASK
;
2252 hash
= rt_hash(daddr
, saddr
, iif
, rt_genid(net
));
2255 for (rth
= rcu_dereference(rt_hash_table
[hash
].chain
); rth
;
2256 rth
= rcu_dereference(rth
->u
.dst
.rt_next
)) {
2257 if (((rth
->fl
.fl4_dst
^ daddr
) |
2258 (rth
->fl
.fl4_src
^ saddr
) |
2259 (rth
->fl
.iif
^ iif
) |
2261 (rth
->fl
.fl4_tos
^ tos
)) == 0 &&
2262 rth
->fl
.mark
== skb
->mark
&&
2263 net_eq(dev_net(rth
->u
.dst
.dev
), net
) &&
2264 !rt_is_expired(rth
)) {
2265 dst_use(&rth
->u
.dst
, jiffies
);
2266 RT_CACHE_STAT_INC(in_hit
);
2271 RT_CACHE_STAT_INC(in_hlist_search
);
2276 /* Multicast recognition logic is moved from route cache to here.
2277 The problem was that too many Ethernet cards have broken/missing
2278 hardware multicast filters :-( As result the host on multicasting
2279 network acquires a lot of useless route cache entries, sort of
2280 SDR messages from all the world. Now we try to get rid of them.
2281 Really, provided software IP multicast filter is organized
2282 reasonably (at least, hashed), it does not result in a slowdown
2283 comparing with route cache reject entries.
2284 Note, that multicast routers are not affected, because
2285 route cache entry is created eventually.
2287 if (ipv4_is_multicast(daddr
)) {
2288 struct in_device
*in_dev
;
2291 if ((in_dev
= __in_dev_get_rcu(dev
)) != NULL
) {
2292 int our
= ip_check_mc(in_dev
, daddr
, saddr
,
2293 ip_hdr(skb
)->protocol
);
2295 #ifdef CONFIG_IP_MROUTE
2296 || (!ipv4_is_local_multicast(daddr
) &&
2297 IN_DEV_MFORWARD(in_dev
))
2301 return ip_route_input_mc(skb
, daddr
, saddr
,
2308 return ip_route_input_slow(skb
, daddr
, saddr
, tos
, dev
);
2311 static int __mkroute_output(struct rtable
**result
,
2312 struct fib_result
*res
,
2313 const struct flowi
*fl
,
2314 const struct flowi
*oldflp
,
2315 struct net_device
*dev_out
,
2319 struct in_device
*in_dev
;
2320 u32 tos
= RT_FL_TOS(oldflp
);
2323 if (ipv4_is_loopback(fl
->fl4_src
) && !(dev_out
->flags
&IFF_LOOPBACK
))
2326 if (fl
->fl4_dst
== htonl(0xFFFFFFFF))
2327 res
->type
= RTN_BROADCAST
;
2328 else if (ipv4_is_multicast(fl
->fl4_dst
))
2329 res
->type
= RTN_MULTICAST
;
2330 else if (ipv4_is_lbcast(fl
->fl4_dst
) || ipv4_is_zeronet(fl
->fl4_dst
))
2333 if (dev_out
->flags
& IFF_LOOPBACK
)
2334 flags
|= RTCF_LOCAL
;
2336 /* get work reference to inet device */
2337 in_dev
= in_dev_get(dev_out
);
2341 if (res
->type
== RTN_BROADCAST
) {
2342 flags
|= RTCF_BROADCAST
| RTCF_LOCAL
;
2344 fib_info_put(res
->fi
);
2347 } else if (res
->type
== RTN_MULTICAST
) {
2348 flags
|= RTCF_MULTICAST
|RTCF_LOCAL
;
2349 if (!ip_check_mc(in_dev
, oldflp
->fl4_dst
, oldflp
->fl4_src
,
2351 flags
&= ~RTCF_LOCAL
;
2352 /* If multicast route do not exist use
2353 default one, but do not gateway in this case.
2356 if (res
->fi
&& res
->prefixlen
< 4) {
2357 fib_info_put(res
->fi
);
2363 rth
= dst_alloc(&ipv4_dst_ops
);
2369 atomic_set(&rth
->u
.dst
.__refcnt
, 1);
2370 rth
->u
.dst
.flags
= DST_HOST
;
2371 if (IN_DEV_CONF_GET(in_dev
, NOXFRM
))
2372 rth
->u
.dst
.flags
|= DST_NOXFRM
;
2373 if (IN_DEV_CONF_GET(in_dev
, NOPOLICY
))
2374 rth
->u
.dst
.flags
|= DST_NOPOLICY
;
2376 rth
->fl
.fl4_dst
= oldflp
->fl4_dst
;
2377 rth
->fl
.fl4_tos
= tos
;
2378 rth
->fl
.fl4_src
= oldflp
->fl4_src
;
2379 rth
->fl
.oif
= oldflp
->oif
;
2380 rth
->fl
.mark
= oldflp
->mark
;
2381 rth
->rt_dst
= fl
->fl4_dst
;
2382 rth
->rt_src
= fl
->fl4_src
;
2383 rth
->rt_iif
= oldflp
->oif
? : dev_out
->ifindex
;
2384 /* get references to the devices that are to be hold by the routing
2386 rth
->u
.dst
.dev
= dev_out
;
2388 rth
->idev
= in_dev_get(dev_out
);
2389 rth
->rt_gateway
= fl
->fl4_dst
;
2390 rth
->rt_spec_dst
= fl
->fl4_src
;
2392 rth
->u
.dst
.output
=ip_output
;
2393 rth
->rt_genid
= rt_genid(dev_net(dev_out
));
2395 RT_CACHE_STAT_INC(out_slow_tot
);
2397 if (flags
& RTCF_LOCAL
) {
2398 rth
->u
.dst
.input
= ip_local_deliver
;
2399 rth
->rt_spec_dst
= fl
->fl4_dst
;
2401 if (flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) {
2402 rth
->rt_spec_dst
= fl
->fl4_src
;
2403 if (flags
& RTCF_LOCAL
&&
2404 !(dev_out
->flags
& IFF_LOOPBACK
)) {
2405 rth
->u
.dst
.output
= ip_mc_output
;
2406 RT_CACHE_STAT_INC(out_slow_mc
);
2408 #ifdef CONFIG_IP_MROUTE
2409 if (res
->type
== RTN_MULTICAST
) {
2410 if (IN_DEV_MFORWARD(in_dev
) &&
2411 !ipv4_is_local_multicast(oldflp
->fl4_dst
)) {
2412 rth
->u
.dst
.input
= ip_mr_input
;
2413 rth
->u
.dst
.output
= ip_mc_output
;
2419 rt_set_nexthop(rth
, res
, 0);
2421 rth
->rt_flags
= flags
;
2425 /* release work reference to inet device */
2431 static int ip_mkroute_output(struct rtable
**rp
,
2432 struct fib_result
*res
,
2433 const struct flowi
*fl
,
2434 const struct flowi
*oldflp
,
2435 struct net_device
*dev_out
,
2438 struct rtable
*rth
= NULL
;
2439 int err
= __mkroute_output(&rth
, res
, fl
, oldflp
, dev_out
, flags
);
2442 hash
= rt_hash(oldflp
->fl4_dst
, oldflp
->fl4_src
, oldflp
->oif
,
2443 rt_genid(dev_net(dev_out
)));
2444 err
= rt_intern_hash(hash
, rth
, rp
);
2451 * Major route resolver routine.
2454 static int ip_route_output_slow(struct net
*net
, struct rtable
**rp
,
2455 const struct flowi
*oldflp
)
2457 u32 tos
= RT_FL_TOS(oldflp
);
2458 struct flowi fl
= { .nl_u
= { .ip4_u
=
2459 { .daddr
= oldflp
->fl4_dst
,
2460 .saddr
= oldflp
->fl4_src
,
2461 .tos
= tos
& IPTOS_RT_MASK
,
2462 .scope
= ((tos
& RTO_ONLINK
) ?
2466 .mark
= oldflp
->mark
,
2467 .iif
= net
->loopback_dev
->ifindex
,
2468 .oif
= oldflp
->oif
};
2469 struct fib_result res
;
2471 struct net_device
*dev_out
= NULL
;
2477 #ifdef CONFIG_IP_MULTIPLE_TABLES
2481 if (oldflp
->fl4_src
) {
2483 if (ipv4_is_multicast(oldflp
->fl4_src
) ||
2484 ipv4_is_lbcast(oldflp
->fl4_src
) ||
2485 ipv4_is_zeronet(oldflp
->fl4_src
))
2488 /* I removed check for oif == dev_out->oif here.
2489 It was wrong for two reasons:
2490 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2491 is assigned to multiple interfaces.
2492 2. Moreover, we are allowed to send packets with saddr
2493 of another iface. --ANK
2496 if (oldflp
->oif
== 0
2497 && (ipv4_is_multicast(oldflp
->fl4_dst
) ||
2498 oldflp
->fl4_dst
== htonl(0xFFFFFFFF))) {
2499 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2500 dev_out
= ip_dev_find(net
, oldflp
->fl4_src
);
2501 if (dev_out
== NULL
)
2504 /* Special hack: user can direct multicasts
2505 and limited broadcast via necessary interface
2506 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2507 This hack is not just for fun, it allows
2508 vic,vat and friends to work.
2509 They bind socket to loopback, set ttl to zero
2510 and expect that it will work.
2511 From the viewpoint of routing cache they are broken,
2512 because we are not allowed to build multicast path
2513 with loopback source addr (look, routing cache
2514 cannot know, that ttl is zero, so that packet
2515 will not leave this host and route is valid).
2516 Luckily, this hack is good workaround.
2519 fl
.oif
= dev_out
->ifindex
;
2523 if (!(oldflp
->flags
& FLOWI_FLAG_ANYSRC
)) {
2524 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2525 dev_out
= ip_dev_find(net
, oldflp
->fl4_src
);
2526 if (dev_out
== NULL
)
2535 dev_out
= dev_get_by_index(net
, oldflp
->oif
);
2537 if (dev_out
== NULL
)
2540 /* RACE: Check return value of inet_select_addr instead. */
2541 if (__in_dev_get_rtnl(dev_out
) == NULL
) {
2543 goto out
; /* Wrong error code */
2546 if (ipv4_is_local_multicast(oldflp
->fl4_dst
) ||
2547 oldflp
->fl4_dst
== htonl(0xFFFFFFFF)) {
2549 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2554 if (ipv4_is_multicast(oldflp
->fl4_dst
))
2555 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2557 else if (!oldflp
->fl4_dst
)
2558 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2564 fl
.fl4_dst
= fl
.fl4_src
;
2566 fl
.fl4_dst
= fl
.fl4_src
= htonl(INADDR_LOOPBACK
);
2569 dev_out
= net
->loopback_dev
;
2571 fl
.oif
= net
->loopback_dev
->ifindex
;
2572 res
.type
= RTN_LOCAL
;
2573 flags
|= RTCF_LOCAL
;
2577 if (fib_lookup(net
, &fl
, &res
)) {
2580 /* Apparently, routing tables are wrong. Assume,
2581 that the destination is on link.
2584 Because we are allowed to send to iface
2585 even if it has NO routes and NO assigned
2586 addresses. When oif is specified, routing
2587 tables are looked up with only one purpose:
2588 to catch if destination is gatewayed, rather than
2589 direct. Moreover, if MSG_DONTROUTE is set,
2590 we send packet, ignoring both routing tables
2591 and ifaddr state. --ANK
2594 We could make it even if oif is unknown,
2595 likely IPv6, but we do not.
2598 if (fl
.fl4_src
== 0)
2599 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2601 res
.type
= RTN_UNICAST
;
2611 if (res
.type
== RTN_LOCAL
) {
2613 fl
.fl4_src
= fl
.fl4_dst
;
2616 dev_out
= net
->loopback_dev
;
2618 fl
.oif
= dev_out
->ifindex
;
2620 fib_info_put(res
.fi
);
2622 flags
|= RTCF_LOCAL
;
2626 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2627 if (res
.fi
->fib_nhs
> 1 && fl
.oif
== 0)
2628 fib_select_multipath(&fl
, &res
);
2631 if (!res
.prefixlen
&& res
.type
== RTN_UNICAST
&& !fl
.oif
)
2632 fib_select_default(net
, &fl
, &res
);
2635 fl
.fl4_src
= FIB_RES_PREFSRC(res
);
2639 dev_out
= FIB_RES_DEV(res
);
2641 fl
.oif
= dev_out
->ifindex
;
2645 err
= ip_mkroute_output(rp
, &res
, &fl
, oldflp
, dev_out
, flags
);
2655 int __ip_route_output_key(struct net
*net
, struct rtable
**rp
,
2656 const struct flowi
*flp
)
2661 if (!rt_caching(net
))
2664 hash
= rt_hash(flp
->fl4_dst
, flp
->fl4_src
, flp
->oif
, rt_genid(net
));
2667 for (rth
= rcu_dereference(rt_hash_table
[hash
].chain
); rth
;
2668 rth
= rcu_dereference(rth
->u
.dst
.rt_next
)) {
2669 if (rth
->fl
.fl4_dst
== flp
->fl4_dst
&&
2670 rth
->fl
.fl4_src
== flp
->fl4_src
&&
2672 rth
->fl
.oif
== flp
->oif
&&
2673 rth
->fl
.mark
== flp
->mark
&&
2674 !((rth
->fl
.fl4_tos
^ flp
->fl4_tos
) &
2675 (IPTOS_RT_MASK
| RTO_ONLINK
)) &&
2676 net_eq(dev_net(rth
->u
.dst
.dev
), net
) &&
2677 !rt_is_expired(rth
)) {
2678 dst_use(&rth
->u
.dst
, jiffies
);
2679 RT_CACHE_STAT_INC(out_hit
);
2680 rcu_read_unlock_bh();
2684 RT_CACHE_STAT_INC(out_hlist_search
);
2686 rcu_read_unlock_bh();
2689 return ip_route_output_slow(net
, rp
, flp
);
2692 EXPORT_SYMBOL_GPL(__ip_route_output_key
);
2694 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry
*dst
, u32 mtu
)
2698 static struct dst_ops ipv4_dst_blackhole_ops
= {
2700 .protocol
= __constant_htons(ETH_P_IP
),
2701 .destroy
= ipv4_dst_destroy
,
2702 .check
= ipv4_dst_check
,
2703 .update_pmtu
= ipv4_rt_blackhole_update_pmtu
,
2704 .entry_size
= sizeof(struct rtable
),
2705 .entries
= ATOMIC_INIT(0),
2709 static int ipv4_dst_blackhole(struct net
*net
, struct rtable
**rp
, struct flowi
*flp
)
2711 struct rtable
*ort
= *rp
;
2712 struct rtable
*rt
= (struct rtable
*)
2713 dst_alloc(&ipv4_dst_blackhole_ops
);
2716 struct dst_entry
*new = &rt
->u
.dst
;
2718 atomic_set(&new->__refcnt
, 1);
2720 new->input
= dst_discard
;
2721 new->output
= dst_discard
;
2722 memcpy(new->metrics
, ort
->u
.dst
.metrics
, RTAX_MAX
*sizeof(u32
));
2724 new->dev
= ort
->u
.dst
.dev
;
2730 rt
->idev
= ort
->idev
;
2732 in_dev_hold(rt
->idev
);
2733 rt
->rt_genid
= rt_genid(net
);
2734 rt
->rt_flags
= ort
->rt_flags
;
2735 rt
->rt_type
= ort
->rt_type
;
2736 rt
->rt_dst
= ort
->rt_dst
;
2737 rt
->rt_src
= ort
->rt_src
;
2738 rt
->rt_iif
= ort
->rt_iif
;
2739 rt
->rt_gateway
= ort
->rt_gateway
;
2740 rt
->rt_spec_dst
= ort
->rt_spec_dst
;
2741 rt
->peer
= ort
->peer
;
2743 atomic_inc(&rt
->peer
->refcnt
);
2748 dst_release(&(*rp
)->u
.dst
);
2750 return (rt
? 0 : -ENOMEM
);
2753 int ip_route_output_flow(struct net
*net
, struct rtable
**rp
, struct flowi
*flp
,
2754 struct sock
*sk
, int flags
)
2758 if ((err
= __ip_route_output_key(net
, rp
, flp
)) != 0)
2763 flp
->fl4_src
= (*rp
)->rt_src
;
2765 flp
->fl4_dst
= (*rp
)->rt_dst
;
2766 err
= __xfrm_lookup((struct dst_entry
**)rp
, flp
, sk
,
2767 flags
? XFRM_LOOKUP_WAIT
: 0);
2768 if (err
== -EREMOTE
)
2769 err
= ipv4_dst_blackhole(net
, rp
, flp
);
2777 EXPORT_SYMBOL_GPL(ip_route_output_flow
);
2779 int ip_route_output_key(struct net
*net
, struct rtable
**rp
, struct flowi
*flp
)
2781 return ip_route_output_flow(net
, rp
, flp
, NULL
, 0);
2784 static int rt_fill_info(struct sk_buff
*skb
, u32 pid
, u32 seq
, int event
,
2785 int nowait
, unsigned int flags
)
2787 struct rtable
*rt
= skb
->rtable
;
2789 struct nlmsghdr
*nlh
;
2791 u32 id
= 0, ts
= 0, tsage
= 0, error
;
2793 nlh
= nlmsg_put(skb
, pid
, seq
, event
, sizeof(*r
), flags
);
2797 r
= nlmsg_data(nlh
);
2798 r
->rtm_family
= AF_INET
;
2799 r
->rtm_dst_len
= 32;
2801 r
->rtm_tos
= rt
->fl
.fl4_tos
;
2802 r
->rtm_table
= RT_TABLE_MAIN
;
2803 NLA_PUT_U32(skb
, RTA_TABLE
, RT_TABLE_MAIN
);
2804 r
->rtm_type
= rt
->rt_type
;
2805 r
->rtm_scope
= RT_SCOPE_UNIVERSE
;
2806 r
->rtm_protocol
= RTPROT_UNSPEC
;
2807 r
->rtm_flags
= (rt
->rt_flags
& ~0xFFFF) | RTM_F_CLONED
;
2808 if (rt
->rt_flags
& RTCF_NOTIFY
)
2809 r
->rtm_flags
|= RTM_F_NOTIFY
;
2811 NLA_PUT_BE32(skb
, RTA_DST
, rt
->rt_dst
);
2813 if (rt
->fl
.fl4_src
) {
2814 r
->rtm_src_len
= 32;
2815 NLA_PUT_BE32(skb
, RTA_SRC
, rt
->fl
.fl4_src
);
2818 NLA_PUT_U32(skb
, RTA_OIF
, rt
->u
.dst
.dev
->ifindex
);
2819 #ifdef CONFIG_NET_CLS_ROUTE
2820 if (rt
->u
.dst
.tclassid
)
2821 NLA_PUT_U32(skb
, RTA_FLOW
, rt
->u
.dst
.tclassid
);
2824 NLA_PUT_BE32(skb
, RTA_PREFSRC
, rt
->rt_spec_dst
);
2825 else if (rt
->rt_src
!= rt
->fl
.fl4_src
)
2826 NLA_PUT_BE32(skb
, RTA_PREFSRC
, rt
->rt_src
);
2828 if (rt
->rt_dst
!= rt
->rt_gateway
)
2829 NLA_PUT_BE32(skb
, RTA_GATEWAY
, rt
->rt_gateway
);
2831 if (rtnetlink_put_metrics(skb
, rt
->u
.dst
.metrics
) < 0)
2832 goto nla_put_failure
;
2834 error
= rt
->u
.dst
.error
;
2835 expires
= rt
->u
.dst
.expires
? rt
->u
.dst
.expires
- jiffies
: 0;
2837 id
= rt
->peer
->ip_id_count
;
2838 if (rt
->peer
->tcp_ts_stamp
) {
2839 ts
= rt
->peer
->tcp_ts
;
2840 tsage
= get_seconds() - rt
->peer
->tcp_ts_stamp
;
2845 #ifdef CONFIG_IP_MROUTE
2846 __be32 dst
= rt
->rt_dst
;
2848 if (ipv4_is_multicast(dst
) && !ipv4_is_local_multicast(dst
) &&
2849 IPV4_DEVCONF_ALL(&init_net
, MC_FORWARDING
)) {
2850 int err
= ipmr_get_route(skb
, r
, nowait
);
2855 goto nla_put_failure
;
2857 if (err
== -EMSGSIZE
)
2858 goto nla_put_failure
;
2864 NLA_PUT_U32(skb
, RTA_IIF
, rt
->fl
.iif
);
2867 if (rtnl_put_cacheinfo(skb
, &rt
->u
.dst
, id
, ts
, tsage
,
2868 expires
, error
) < 0)
2869 goto nla_put_failure
;
2871 return nlmsg_end(skb
, nlh
);
2874 nlmsg_cancel(skb
, nlh
);
2878 static int inet_rtm_getroute(struct sk_buff
*in_skb
, struct nlmsghdr
* nlh
, void *arg
)
2880 struct net
*net
= sock_net(in_skb
->sk
);
2882 struct nlattr
*tb
[RTA_MAX
+1];
2883 struct rtable
*rt
= NULL
;
2888 struct sk_buff
*skb
;
2890 err
= nlmsg_parse(nlh
, sizeof(*rtm
), tb
, RTA_MAX
, rtm_ipv4_policy
);
2894 rtm
= nlmsg_data(nlh
);
2896 skb
= alloc_skb(NLMSG_GOODSIZE
, GFP_KERNEL
);
2902 /* Reserve room for dummy headers, this skb can pass
2903 through good chunk of routing engine.
2905 skb_reset_mac_header(skb
);
2906 skb_reset_network_header(skb
);
2908 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2909 ip_hdr(skb
)->protocol
= IPPROTO_ICMP
;
2910 skb_reserve(skb
, MAX_HEADER
+ sizeof(struct iphdr
));
2912 src
= tb
[RTA_SRC
] ? nla_get_be32(tb
[RTA_SRC
]) : 0;
2913 dst
= tb
[RTA_DST
] ? nla_get_be32(tb
[RTA_DST
]) : 0;
2914 iif
= tb
[RTA_IIF
] ? nla_get_u32(tb
[RTA_IIF
]) : 0;
2917 struct net_device
*dev
;
2919 dev
= __dev_get_by_index(net
, iif
);
2925 skb
->protocol
= htons(ETH_P_IP
);
2928 err
= ip_route_input(skb
, dst
, src
, rtm
->rtm_tos
, dev
);
2932 if (err
== 0 && rt
->u
.dst
.error
)
2933 err
= -rt
->u
.dst
.error
;
2940 .tos
= rtm
->rtm_tos
,
2943 .oif
= tb
[RTA_OIF
] ? nla_get_u32(tb
[RTA_OIF
]) : 0,
2945 err
= ip_route_output_key(net
, &rt
, &fl
);
2952 if (rtm
->rtm_flags
& RTM_F_NOTIFY
)
2953 rt
->rt_flags
|= RTCF_NOTIFY
;
2955 err
= rt_fill_info(skb
, NETLINK_CB(in_skb
).pid
, nlh
->nlmsg_seq
,
2956 RTM_NEWROUTE
, 0, 0);
2960 err
= rtnl_unicast(skb
, net
, NETLINK_CB(in_skb
).pid
);
2969 int ip_rt_dump(struct sk_buff
*skb
, struct netlink_callback
*cb
)
2976 net
= sock_net(skb
->sk
);
2981 s_idx
= idx
= cb
->args
[1];
2982 for (h
= s_h
; h
<= rt_hash_mask
; h
++, s_idx
= 0) {
2983 if (!rt_hash_table
[h
].chain
)
2986 for (rt
= rcu_dereference(rt_hash_table
[h
].chain
), idx
= 0; rt
;
2987 rt
= rcu_dereference(rt
->u
.dst
.rt_next
), idx
++) {
2988 if (!net_eq(dev_net(rt
->u
.dst
.dev
), net
) || idx
< s_idx
)
2990 if (rt_is_expired(rt
))
2992 skb
->dst
= dst_clone(&rt
->u
.dst
);
2993 if (rt_fill_info(skb
, NETLINK_CB(cb
->skb
).pid
,
2994 cb
->nlh
->nlmsg_seq
, RTM_NEWROUTE
,
2995 1, NLM_F_MULTI
) <= 0) {
2996 dst_release(xchg(&skb
->dst
, NULL
));
2997 rcu_read_unlock_bh();
3000 dst_release(xchg(&skb
->dst
, NULL
));
3002 rcu_read_unlock_bh();
3011 void ip_rt_multicast_event(struct in_device
*in_dev
)
3013 rt_cache_flush(dev_net(in_dev
->dev
), 0);
3016 #ifdef CONFIG_SYSCTL
3017 static int ipv4_sysctl_rtcache_flush(ctl_table
*__ctl
, int write
,
3018 struct file
*filp
, void __user
*buffer
,
3019 size_t *lenp
, loff_t
*ppos
)
3026 memcpy(&ctl
, __ctl
, sizeof(ctl
));
3027 ctl
.data
= &flush_delay
;
3028 proc_dointvec(&ctl
, write
, filp
, buffer
, lenp
, ppos
);
3030 net
= (struct net
*)__ctl
->extra1
;
3031 rt_cache_flush(net
, flush_delay
);
3038 static int ipv4_sysctl_rtcache_flush_strategy(ctl_table
*table
,
3039 void __user
*oldval
,
3040 size_t __user
*oldlenp
,
3041 void __user
*newval
,
3046 if (newlen
!= sizeof(int))
3048 if (get_user(delay
, (int __user
*)newval
))
3050 net
= (struct net
*)table
->extra1
;
3051 rt_cache_flush(net
, delay
);
3055 static void rt_secret_reschedule(int old
)
3058 int new = ip_rt_secret_interval
;
3059 int diff
= new - old
;
3066 int deleted
= del_timer_sync(&net
->ipv4
.rt_secret_timer
);
3072 long time
= net
->ipv4
.rt_secret_timer
.expires
- jiffies
;
3074 if (time
<= 0 || (time
+= diff
) <= 0)
3077 net
->ipv4
.rt_secret_timer
.expires
= time
;
3079 net
->ipv4
.rt_secret_timer
.expires
= new;
3081 net
->ipv4
.rt_secret_timer
.expires
+= jiffies
;
3082 add_timer(&net
->ipv4
.rt_secret_timer
);
3087 static int ipv4_sysctl_rt_secret_interval(ctl_table
*ctl
, int write
,
3089 void __user
*buffer
, size_t *lenp
,
3092 int old
= ip_rt_secret_interval
;
3093 int ret
= proc_dointvec_jiffies(ctl
, write
, filp
, buffer
, lenp
, ppos
);
3095 rt_secret_reschedule(old
);
3100 static int ipv4_sysctl_rt_secret_interval_strategy(ctl_table
*table
,
3101 void __user
*oldval
,
3102 size_t __user
*oldlenp
,
3103 void __user
*newval
,
3106 int old
= ip_rt_secret_interval
;
3107 int ret
= sysctl_jiffies(table
, oldval
, oldlenp
, newval
, newlen
);
3109 rt_secret_reschedule(old
);
3114 static ctl_table ipv4_route_table
[] = {
3116 .ctl_name
= NET_IPV4_ROUTE_GC_THRESH
,
3117 .procname
= "gc_thresh",
3118 .data
= &ipv4_dst_ops
.gc_thresh
,
3119 .maxlen
= sizeof(int),
3121 .proc_handler
= &proc_dointvec
,
3124 .ctl_name
= NET_IPV4_ROUTE_MAX_SIZE
,
3125 .procname
= "max_size",
3126 .data
= &ip_rt_max_size
,
3127 .maxlen
= sizeof(int),
3129 .proc_handler
= &proc_dointvec
,
3132 /* Deprecated. Use gc_min_interval_ms */
3134 .ctl_name
= NET_IPV4_ROUTE_GC_MIN_INTERVAL
,
3135 .procname
= "gc_min_interval",
3136 .data
= &ip_rt_gc_min_interval
,
3137 .maxlen
= sizeof(int),
3139 .proc_handler
= &proc_dointvec_jiffies
,
3140 .strategy
= &sysctl_jiffies
,
3143 .ctl_name
= NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS
,
3144 .procname
= "gc_min_interval_ms",
3145 .data
= &ip_rt_gc_min_interval
,
3146 .maxlen
= sizeof(int),
3148 .proc_handler
= &proc_dointvec_ms_jiffies
,
3149 .strategy
= &sysctl_ms_jiffies
,
3152 .ctl_name
= NET_IPV4_ROUTE_GC_TIMEOUT
,
3153 .procname
= "gc_timeout",
3154 .data
= &ip_rt_gc_timeout
,
3155 .maxlen
= sizeof(int),
3157 .proc_handler
= &proc_dointvec_jiffies
,
3158 .strategy
= &sysctl_jiffies
,
3161 .ctl_name
= NET_IPV4_ROUTE_GC_INTERVAL
,
3162 .procname
= "gc_interval",
3163 .data
= &ip_rt_gc_interval
,
3164 .maxlen
= sizeof(int),
3166 .proc_handler
= &proc_dointvec_jiffies
,
3167 .strategy
= &sysctl_jiffies
,
3170 .ctl_name
= NET_IPV4_ROUTE_REDIRECT_LOAD
,
3171 .procname
= "redirect_load",
3172 .data
= &ip_rt_redirect_load
,
3173 .maxlen
= sizeof(int),
3175 .proc_handler
= &proc_dointvec
,
3178 .ctl_name
= NET_IPV4_ROUTE_REDIRECT_NUMBER
,
3179 .procname
= "redirect_number",
3180 .data
= &ip_rt_redirect_number
,
3181 .maxlen
= sizeof(int),
3183 .proc_handler
= &proc_dointvec
,
3186 .ctl_name
= NET_IPV4_ROUTE_REDIRECT_SILENCE
,
3187 .procname
= "redirect_silence",
3188 .data
= &ip_rt_redirect_silence
,
3189 .maxlen
= sizeof(int),
3191 .proc_handler
= &proc_dointvec
,
3194 .ctl_name
= NET_IPV4_ROUTE_ERROR_COST
,
3195 .procname
= "error_cost",
3196 .data
= &ip_rt_error_cost
,
3197 .maxlen
= sizeof(int),
3199 .proc_handler
= &proc_dointvec
,
3202 .ctl_name
= NET_IPV4_ROUTE_ERROR_BURST
,
3203 .procname
= "error_burst",
3204 .data
= &ip_rt_error_burst
,
3205 .maxlen
= sizeof(int),
3207 .proc_handler
= &proc_dointvec
,
3210 .ctl_name
= NET_IPV4_ROUTE_GC_ELASTICITY
,
3211 .procname
= "gc_elasticity",
3212 .data
= &ip_rt_gc_elasticity
,
3213 .maxlen
= sizeof(int),
3215 .proc_handler
= &proc_dointvec
,
3218 .ctl_name
= NET_IPV4_ROUTE_MTU_EXPIRES
,
3219 .procname
= "mtu_expires",
3220 .data
= &ip_rt_mtu_expires
,
3221 .maxlen
= sizeof(int),
3223 .proc_handler
= &proc_dointvec_jiffies
,
3224 .strategy
= &sysctl_jiffies
,
3227 .ctl_name
= NET_IPV4_ROUTE_MIN_PMTU
,
3228 .procname
= "min_pmtu",
3229 .data
= &ip_rt_min_pmtu
,
3230 .maxlen
= sizeof(int),
3232 .proc_handler
= &proc_dointvec
,
3235 .ctl_name
= NET_IPV4_ROUTE_MIN_ADVMSS
,
3236 .procname
= "min_adv_mss",
3237 .data
= &ip_rt_min_advmss
,
3238 .maxlen
= sizeof(int),
3240 .proc_handler
= &proc_dointvec
,
3243 .ctl_name
= NET_IPV4_ROUTE_SECRET_INTERVAL
,
3244 .procname
= "secret_interval",
3245 .data
= &ip_rt_secret_interval
,
3246 .maxlen
= sizeof(int),
3248 .proc_handler
= &ipv4_sysctl_rt_secret_interval
,
3249 .strategy
= &ipv4_sysctl_rt_secret_interval_strategy
,
3254 static struct ctl_table empty
[1];
3256 static struct ctl_table ipv4_skeleton
[] =
3258 { .procname
= "route", .ctl_name
= NET_IPV4_ROUTE
,
3259 .mode
= 0555, .child
= ipv4_route_table
},
3260 { .procname
= "neigh", .ctl_name
= NET_IPV4_NEIGH
,
3261 .mode
= 0555, .child
= empty
},
3265 static __net_initdata
struct ctl_path ipv4_path
[] = {
3266 { .procname
= "net", .ctl_name
= CTL_NET
, },
3267 { .procname
= "ipv4", .ctl_name
= NET_IPV4
, },
3271 static struct ctl_table ipv4_route_flush_table
[] = {
3273 .ctl_name
= NET_IPV4_ROUTE_FLUSH
,
3274 .procname
= "flush",
3275 .maxlen
= sizeof(int),
3277 .proc_handler
= &ipv4_sysctl_rtcache_flush
,
3278 .strategy
= &ipv4_sysctl_rtcache_flush_strategy
,
3283 static __net_initdata
struct ctl_path ipv4_route_path
[] = {
3284 { .procname
= "net", .ctl_name
= CTL_NET
, },
3285 { .procname
= "ipv4", .ctl_name
= NET_IPV4
, },
3286 { .procname
= "route", .ctl_name
= NET_IPV4_ROUTE
, },
3290 static __net_init
int sysctl_route_net_init(struct net
*net
)
3292 struct ctl_table
*tbl
;
3294 tbl
= ipv4_route_flush_table
;
3295 if (net
!= &init_net
) {
3296 tbl
= kmemdup(tbl
, sizeof(ipv4_route_flush_table
), GFP_KERNEL
);
3300 tbl
[0].extra1
= net
;
3302 net
->ipv4
.route_hdr
=
3303 register_net_sysctl_table(net
, ipv4_route_path
, tbl
);
3304 if (net
->ipv4
.route_hdr
== NULL
)
3309 if (tbl
!= ipv4_route_flush_table
)
3315 static __net_exit
void sysctl_route_net_exit(struct net
*net
)
3317 struct ctl_table
*tbl
;
3319 tbl
= net
->ipv4
.route_hdr
->ctl_table_arg
;
3320 unregister_net_sysctl_table(net
->ipv4
.route_hdr
);
3321 BUG_ON(tbl
== ipv4_route_flush_table
);
3325 static __net_initdata
struct pernet_operations sysctl_route_ops
= {
3326 .init
= sysctl_route_net_init
,
3327 .exit
= sysctl_route_net_exit
,
3332 static __net_init
int rt_secret_timer_init(struct net
*net
)
3334 atomic_set(&net
->ipv4
.rt_genid
,
3335 (int) ((num_physpages
^ (num_physpages
>>8)) ^
3336 (jiffies
^ (jiffies
>> 7))));
3338 net
->ipv4
.rt_secret_timer
.function
= rt_secret_rebuild
;
3339 net
->ipv4
.rt_secret_timer
.data
= (unsigned long)net
;
3340 init_timer_deferrable(&net
->ipv4
.rt_secret_timer
);
3342 if (ip_rt_secret_interval
) {
3343 net
->ipv4
.rt_secret_timer
.expires
=
3344 jiffies
+ net_random() % ip_rt_secret_interval
+
3345 ip_rt_secret_interval
;
3346 add_timer(&net
->ipv4
.rt_secret_timer
);
3351 static __net_exit
void rt_secret_timer_exit(struct net
*net
)
3353 del_timer_sync(&net
->ipv4
.rt_secret_timer
);
3356 static __net_initdata
struct pernet_operations rt_secret_timer_ops
= {
3357 .init
= rt_secret_timer_init
,
3358 .exit
= rt_secret_timer_exit
,
3362 #ifdef CONFIG_NET_CLS_ROUTE
3363 struct ip_rt_acct
*ip_rt_acct __read_mostly
;
3364 #endif /* CONFIG_NET_CLS_ROUTE */
3366 static __initdata
unsigned long rhash_entries
;
3367 static int __init
set_rhash_entries(char *str
)
3371 rhash_entries
= simple_strtoul(str
, &str
, 0);
3374 __setup("rhash_entries=", set_rhash_entries
);
3376 int __init
ip_rt_init(void)
3380 #ifdef CONFIG_NET_CLS_ROUTE
3381 ip_rt_acct
= __alloc_percpu(256 * sizeof(struct ip_rt_acct
));
3383 panic("IP: failed to allocate ip_rt_acct\n");
3386 ipv4_dst_ops
.kmem_cachep
=
3387 kmem_cache_create("ip_dst_cache", sizeof(struct rtable
), 0,
3388 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3390 ipv4_dst_blackhole_ops
.kmem_cachep
= ipv4_dst_ops
.kmem_cachep
;
3392 rt_hash_table
= (struct rt_hash_bucket
*)
3393 alloc_large_system_hash("IP route cache",
3394 sizeof(struct rt_hash_bucket
),
3396 (num_physpages
>= 128 * 1024) ?
3402 memset(rt_hash_table
, 0, (rt_hash_mask
+ 1) * sizeof(struct rt_hash_bucket
));
3403 rt_hash_lock_init();
3405 ipv4_dst_ops
.gc_thresh
= (rt_hash_mask
+ 1);
3406 ip_rt_max_size
= (rt_hash_mask
+ 1) * 16;
3411 /* All the timers, started at system startup tend
3412 to synchronize. Perturb it a bit.
3414 schedule_delayed_work(&expires_work
,
3415 net_random() % ip_rt_gc_interval
+ ip_rt_gc_interval
);
3417 if (register_pernet_subsys(&rt_secret_timer_ops
))
3418 printk(KERN_ERR
"Unable to setup rt_secret_timer\n");
3420 if (ip_rt_proc_init())
3421 printk(KERN_ERR
"Unable to create route proc files\n");
3426 rtnl_register(PF_INET
, RTM_GETROUTE
, inet_rtm_getroute
, NULL
);
3428 #ifdef CONFIG_SYSCTL
3429 register_pernet_subsys(&sysctl_route_ops
);
3434 #ifdef CONFIG_SYSCTL
3436 * We really need to sanitize the damn ipv4 init order, then all
3437 * this nonsense will go away.
3439 void __init
ip_static_sysctl_init(void)
3441 register_sysctl_paths(ipv4_path
, ipv4_skeleton
);
3445 EXPORT_SYMBOL(__ip_select_ident
);
3446 EXPORT_SYMBOL(ip_route_input
);
3447 EXPORT_SYMBOL(ip_route_output_key
);