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.
8 * Version: $Id: route.c,v 1.103 2002/01/12 07:44:09 davem Exp $
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Alan Cox, <gw4pts@gw4pts.ampr.org>
13 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
14 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
17 * Alan Cox : Verify area fixes.
18 * Alan Cox : cli() protects routing changes
19 * Rui Oliveira : ICMP routing table updates
20 * (rco@di.uminho.pt) Routing table insertion and update
21 * Linus Torvalds : Rewrote bits to be sensible
22 * Alan Cox : Added BSD route gw semantics
23 * Alan Cox : Super /proc >4K
24 * Alan Cox : MTU in route table
25 * Alan Cox : MSS actually. Also added the window
27 * Sam Lantinga : Fixed route matching in rt_del()
28 * Alan Cox : Routing cache support.
29 * Alan Cox : Removed compatibility cruft.
30 * Alan Cox : RTF_REJECT support.
31 * Alan Cox : TCP irtt support.
32 * Jonathan Naylor : Added Metric support.
33 * Miquel van Smoorenburg : BSD API fixes.
34 * Miquel van Smoorenburg : Metrics.
35 * Alan Cox : Use __u32 properly
36 * Alan Cox : Aligned routing errors more closely with BSD
37 * our system is still very different.
38 * Alan Cox : Faster /proc handling
39 * Alexey Kuznetsov : Massive rework to support tree based routing,
40 * routing caches and better behaviour.
42 * Olaf Erb : irtt wasn't being copied right.
43 * Bjorn Ekwall : Kerneld route support.
44 * Alan Cox : Multicast fixed (I hope)
45 * Pavel Krauz : Limited broadcast fixed
46 * Mike McLagan : Routing by source
47 * Alexey Kuznetsov : End of old history. Split to fib.c and
48 * route.c and rewritten from scratch.
49 * Andi Kleen : Load-limit warning messages.
50 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
51 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
52 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
53 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
54 * Marc Boucher : routing by fwmark
55 * Robert Olsson : Added rt_cache statistics
56 * Arnaldo C. Melo : Convert proc stuff to seq_file
57 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
58 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
59 * Ilia Sotnikov : Removed TOS from hash calculations
61 * This program is free software; you can redistribute it and/or
62 * modify it under the terms of the GNU General Public License
63 * as published by the Free Software Foundation; either version
64 * 2 of the License, or (at your option) any later version.
67 #include <linux/module.h>
68 #include <asm/uaccess.h>
69 #include <asm/system.h>
70 #include <linux/bitops.h>
71 #include <linux/types.h>
72 #include <linux/kernel.h>
73 #include <linux/sched.h>
75 #include <linux/bootmem.h>
76 #include <linux/string.h>
77 #include <linux/socket.h>
78 #include <linux/sockios.h>
79 #include <linux/errno.h>
81 #include <linux/inet.h>
82 #include <linux/netdevice.h>
83 #include <linux/proc_fs.h>
84 #include <linux/init.h>
85 #include <linux/skbuff.h>
86 #include <linux/rtnetlink.h>
87 #include <linux/inetdevice.h>
88 #include <linux/igmp.h>
89 #include <linux/pkt_sched.h>
90 #include <linux/mroute.h>
91 #include <linux/netfilter_ipv4.h>
92 #include <linux/random.h>
93 #include <linux/jhash.h>
94 #include <linux/rcupdate.h>
95 #include <linux/times.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/ip_mp_alg.h>
107 #include <net/netevent.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_min_delay
= 2 * HZ
;
120 static int ip_rt_max_delay
= 10 * HZ
;
121 static int ip_rt_max_size
;
122 static int ip_rt_gc_timeout
= RT_GC_TIMEOUT
;
123 static int ip_rt_gc_interval
= 60 * HZ
;
124 static int ip_rt_gc_min_interval
= HZ
/ 2;
125 static int ip_rt_redirect_number
= 9;
126 static int ip_rt_redirect_load
= HZ
/ 50;
127 static int ip_rt_redirect_silence
= ((HZ
/ 50) << (9 + 1));
128 static int ip_rt_error_cost
= HZ
;
129 static int ip_rt_error_burst
= 5 * HZ
;
130 static int ip_rt_gc_elasticity
= 8;
131 static int ip_rt_mtu_expires
= 10 * 60 * HZ
;
132 static int ip_rt_min_pmtu
= 512 + 20 + 20;
133 static int ip_rt_min_advmss
= 256;
134 static int ip_rt_secret_interval
= 10 * 60 * HZ
;
135 static unsigned long rt_deadline
;
137 #define RTprint(a...) printk(KERN_DEBUG a)
139 static struct timer_list rt_flush_timer
;
140 static struct timer_list rt_periodic_timer
;
141 static struct timer_list rt_secret_timer
;
144 * Interface to generic destination cache.
147 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
);
148 static void ipv4_dst_destroy(struct dst_entry
*dst
);
149 static void ipv4_dst_ifdown(struct dst_entry
*dst
,
150 struct net_device
*dev
, int how
);
151 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
);
152 static void ipv4_link_failure(struct sk_buff
*skb
);
153 static void ip_rt_update_pmtu(struct dst_entry
*dst
, u32 mtu
);
154 static int rt_garbage_collect(void);
157 static struct dst_ops ipv4_dst_ops
= {
159 .protocol
= __constant_htons(ETH_P_IP
),
160 .gc
= rt_garbage_collect
,
161 .check
= ipv4_dst_check
,
162 .destroy
= ipv4_dst_destroy
,
163 .ifdown
= ipv4_dst_ifdown
,
164 .negative_advice
= ipv4_negative_advice
,
165 .link_failure
= ipv4_link_failure
,
166 .update_pmtu
= ip_rt_update_pmtu
,
167 .entry_size
= sizeof(struct rtable
),
170 #define ECN_OR_COST(class) TC_PRIO_##class
172 __u8 ip_tos2prio
[16] = {
176 ECN_OR_COST(BESTEFFORT
),
182 ECN_OR_COST(INTERACTIVE
),
184 ECN_OR_COST(INTERACTIVE
),
185 TC_PRIO_INTERACTIVE_BULK
,
186 ECN_OR_COST(INTERACTIVE_BULK
),
187 TC_PRIO_INTERACTIVE_BULK
,
188 ECN_OR_COST(INTERACTIVE_BULK
)
196 /* The locking scheme is rather straight forward:
198 * 1) Read-Copy Update protects the buckets of the central route hash.
199 * 2) Only writers remove entries, and they hold the lock
200 * as they look at rtable reference counts.
201 * 3) Only readers acquire references to rtable entries,
202 * they do so with atomic increments and with the
206 struct rt_hash_bucket
{
207 struct rtable
*chain
;
209 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
210 defined(CONFIG_PROVE_LOCKING)
212 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
213 * The size of this table is a power of two and depends on the number of CPUS.
214 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
216 #ifdef CONFIG_LOCKDEP
217 # define RT_HASH_LOCK_SZ 256
220 # define RT_HASH_LOCK_SZ 4096
222 # define RT_HASH_LOCK_SZ 2048
224 # define RT_HASH_LOCK_SZ 1024
226 # define RT_HASH_LOCK_SZ 512
228 # define RT_HASH_LOCK_SZ 256
232 static spinlock_t
*rt_hash_locks
;
233 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
234 # define rt_hash_lock_init() { \
236 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ, GFP_KERNEL); \
237 if (!rt_hash_locks) panic("IP: failed to allocate rt_hash_locks\n"); \
238 for (i = 0; i < RT_HASH_LOCK_SZ; i++) \
239 spin_lock_init(&rt_hash_locks[i]); \
242 # define rt_hash_lock_addr(slot) NULL
243 # define rt_hash_lock_init()
246 static struct rt_hash_bucket
*rt_hash_table
;
247 static unsigned rt_hash_mask
;
248 static int rt_hash_log
;
249 static unsigned int rt_hash_rnd
;
251 static DEFINE_PER_CPU(struct rt_cache_stat
, rt_cache_stat
);
252 #define RT_CACHE_STAT_INC(field) \
253 (__raw_get_cpu_var(rt_cache_stat).field++)
255 static int rt_intern_hash(unsigned hash
, struct rtable
*rth
,
256 struct rtable
**res
);
258 static unsigned int rt_hash_code(u32 daddr
, u32 saddr
)
260 return (jhash_2words(daddr
, saddr
, rt_hash_rnd
)
264 #define rt_hash(daddr, saddr, idx) \
265 rt_hash_code((__force u32)(__be32)(daddr),\
266 (__force u32)(__be32)(saddr) ^ ((idx) << 5))
268 #ifdef CONFIG_PROC_FS
269 struct rt_cache_iter_state
{
273 static struct rtable
*rt_cache_get_first(struct seq_file
*seq
)
275 struct rtable
*r
= NULL
;
276 struct rt_cache_iter_state
*st
= seq
->private;
278 for (st
->bucket
= rt_hash_mask
; st
->bucket
>= 0; --st
->bucket
) {
280 r
= rt_hash_table
[st
->bucket
].chain
;
283 rcu_read_unlock_bh();
288 static struct rtable
*rt_cache_get_next(struct seq_file
*seq
, struct rtable
*r
)
290 struct rt_cache_iter_state
*st
= rcu_dereference(seq
->private);
294 rcu_read_unlock_bh();
295 if (--st
->bucket
< 0)
298 r
= rt_hash_table
[st
->bucket
].chain
;
303 static struct rtable
*rt_cache_get_idx(struct seq_file
*seq
, loff_t pos
)
305 struct rtable
*r
= rt_cache_get_first(seq
);
308 while (pos
&& (r
= rt_cache_get_next(seq
, r
)))
310 return pos
? NULL
: r
;
313 static void *rt_cache_seq_start(struct seq_file
*seq
, loff_t
*pos
)
315 return *pos
? rt_cache_get_idx(seq
, *pos
- 1) : SEQ_START_TOKEN
;
318 static void *rt_cache_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
320 struct rtable
*r
= NULL
;
322 if (v
== SEQ_START_TOKEN
)
323 r
= rt_cache_get_first(seq
);
325 r
= rt_cache_get_next(seq
, v
);
330 static void rt_cache_seq_stop(struct seq_file
*seq
, void *v
)
332 if (v
&& v
!= SEQ_START_TOKEN
)
333 rcu_read_unlock_bh();
336 static int rt_cache_seq_show(struct seq_file
*seq
, void *v
)
338 if (v
== SEQ_START_TOKEN
)
339 seq_printf(seq
, "%-127s\n",
340 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
341 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
344 struct rtable
*r
= v
;
347 sprintf(temp
, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
348 "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X",
349 r
->u
.dst
.dev
? r
->u
.dst
.dev
->name
: "*",
350 (unsigned long)r
->rt_dst
, (unsigned long)r
->rt_gateway
,
351 r
->rt_flags
, atomic_read(&r
->u
.dst
.__refcnt
),
352 r
->u
.dst
.__use
, 0, (unsigned long)r
->rt_src
,
353 (dst_metric(&r
->u
.dst
, RTAX_ADVMSS
) ?
354 (int)dst_metric(&r
->u
.dst
, RTAX_ADVMSS
) + 40 : 0),
355 dst_metric(&r
->u
.dst
, RTAX_WINDOW
),
356 (int)((dst_metric(&r
->u
.dst
, RTAX_RTT
) >> 3) +
357 dst_metric(&r
->u
.dst
, RTAX_RTTVAR
)),
359 r
->u
.dst
.hh
? atomic_read(&r
->u
.dst
.hh
->hh_refcnt
) : -1,
360 r
->u
.dst
.hh
? (r
->u
.dst
.hh
->hh_output
==
363 seq_printf(seq
, "%-127s\n", temp
);
368 static struct seq_operations rt_cache_seq_ops
= {
369 .start
= rt_cache_seq_start
,
370 .next
= rt_cache_seq_next
,
371 .stop
= rt_cache_seq_stop
,
372 .show
= rt_cache_seq_show
,
375 static int rt_cache_seq_open(struct inode
*inode
, struct file
*file
)
377 struct seq_file
*seq
;
379 struct rt_cache_iter_state
*s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
383 rc
= seq_open(file
, &rt_cache_seq_ops
);
386 seq
= file
->private_data
;
388 memset(s
, 0, sizeof(*s
));
396 static struct file_operations rt_cache_seq_fops
= {
397 .owner
= THIS_MODULE
,
398 .open
= rt_cache_seq_open
,
401 .release
= seq_release_private
,
405 static void *rt_cpu_seq_start(struct seq_file
*seq
, loff_t
*pos
)
410 return SEQ_START_TOKEN
;
412 for (cpu
= *pos
-1; cpu
< NR_CPUS
; ++cpu
) {
413 if (!cpu_possible(cpu
))
416 return &per_cpu(rt_cache_stat
, cpu
);
421 static void *rt_cpu_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
425 for (cpu
= *pos
; cpu
< NR_CPUS
; ++cpu
) {
426 if (!cpu_possible(cpu
))
429 return &per_cpu(rt_cache_stat
, cpu
);
435 static void rt_cpu_seq_stop(struct seq_file
*seq
, void *v
)
440 static int rt_cpu_seq_show(struct seq_file
*seq
, void *v
)
442 struct rt_cache_stat
*st
= v
;
444 if (v
== SEQ_START_TOKEN
) {
445 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");
449 seq_printf(seq
,"%08x %08x %08x %08x %08x %08x %08x %08x "
450 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
451 atomic_read(&ipv4_dst_ops
.entries
),
474 static struct seq_operations rt_cpu_seq_ops
= {
475 .start
= rt_cpu_seq_start
,
476 .next
= rt_cpu_seq_next
,
477 .stop
= rt_cpu_seq_stop
,
478 .show
= rt_cpu_seq_show
,
482 static int rt_cpu_seq_open(struct inode
*inode
, struct file
*file
)
484 return seq_open(file
, &rt_cpu_seq_ops
);
487 static struct file_operations rt_cpu_seq_fops
= {
488 .owner
= THIS_MODULE
,
489 .open
= rt_cpu_seq_open
,
492 .release
= seq_release
,
495 #endif /* CONFIG_PROC_FS */
497 static __inline__
void rt_free(struct rtable
*rt
)
499 multipath_remove(rt
);
500 call_rcu_bh(&rt
->u
.dst
.rcu_head
, dst_rcu_free
);
503 static __inline__
void rt_drop(struct rtable
*rt
)
505 multipath_remove(rt
);
507 call_rcu_bh(&rt
->u
.dst
.rcu_head
, dst_rcu_free
);
510 static __inline__
int rt_fast_clean(struct rtable
*rth
)
512 /* Kill broadcast/multicast entries very aggresively, if they
513 collide in hash table with more useful entries */
514 return (rth
->rt_flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) &&
515 rth
->fl
.iif
&& rth
->u
.rt_next
;
518 static __inline__
int rt_valuable(struct rtable
*rth
)
520 return (rth
->rt_flags
& (RTCF_REDIRECTED
| RTCF_NOTIFY
)) ||
524 static int rt_may_expire(struct rtable
*rth
, unsigned long tmo1
, unsigned long tmo2
)
529 if (atomic_read(&rth
->u
.dst
.__refcnt
))
533 if (rth
->u
.dst
.expires
&&
534 time_after_eq(jiffies
, rth
->u
.dst
.expires
))
537 age
= jiffies
- rth
->u
.dst
.lastuse
;
539 if ((age
<= tmo1
&& !rt_fast_clean(rth
)) ||
540 (age
<= tmo2
&& rt_valuable(rth
)))
546 /* Bits of score are:
548 * 30: not quite useless
549 * 29..0: usage counter
551 static inline u32
rt_score(struct rtable
*rt
)
553 u32 score
= jiffies
- rt
->u
.dst
.lastuse
;
555 score
= ~score
& ~(3<<30);
561 !(rt
->rt_flags
& (RTCF_BROADCAST
|RTCF_MULTICAST
|RTCF_LOCAL
)))
567 static inline int compare_keys(struct flowi
*fl1
, struct flowi
*fl2
)
569 return ((fl1
->nl_u
.ip4_u
.daddr
^ fl2
->nl_u
.ip4_u
.daddr
) |
570 (fl1
->nl_u
.ip4_u
.saddr
^ fl2
->nl_u
.ip4_u
.saddr
) |
571 #ifdef CONFIG_IP_ROUTE_FWMARK
572 (fl1
->nl_u
.ip4_u
.fwmark
^ fl2
->nl_u
.ip4_u
.fwmark
) |
574 (*(u16
*)&fl1
->nl_u
.ip4_u
.tos
^
575 *(u16
*)&fl2
->nl_u
.ip4_u
.tos
) |
576 (fl1
->oif
^ fl2
->oif
) |
577 (fl1
->iif
^ fl2
->iif
)) == 0;
580 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
581 static struct rtable
**rt_remove_balanced_route(struct rtable
**chain_head
,
582 struct rtable
*expentry
,
585 int passedexpired
= 0;
586 struct rtable
**nextstep
= NULL
;
587 struct rtable
**rthp
= chain_head
;
593 while ((rth
= *rthp
) != NULL
) {
597 if (((*rthp
)->u
.dst
.flags
& DST_BALANCED
) != 0 &&
598 compare_keys(&(*rthp
)->fl
, &expentry
->fl
)) {
599 if (*rthp
== expentry
) {
600 *rthp
= rth
->u
.rt_next
;
603 *rthp
= rth
->u
.rt_next
;
609 if (!((*rthp
)->u
.dst
.flags
& DST_BALANCED
) &&
610 passedexpired
&& !nextstep
)
611 nextstep
= &rth
->u
.rt_next
;
613 rthp
= &rth
->u
.rt_next
;
623 #endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
626 /* This runs via a timer and thus is always in BH context. */
627 static void rt_check_expire(unsigned long dummy
)
629 static unsigned int rover
;
630 unsigned int i
= rover
, goal
;
631 struct rtable
*rth
, **rthp
;
632 unsigned long now
= jiffies
;
635 mult
= ((u64
)ip_rt_gc_interval
) << rt_hash_log
;
636 if (ip_rt_gc_timeout
> 1)
637 do_div(mult
, ip_rt_gc_timeout
);
638 goal
= (unsigned int)mult
;
639 if (goal
> rt_hash_mask
) goal
= rt_hash_mask
+ 1;
640 for (; goal
> 0; goal
--) {
641 unsigned long tmo
= ip_rt_gc_timeout
;
643 i
= (i
+ 1) & rt_hash_mask
;
644 rthp
= &rt_hash_table
[i
].chain
;
648 spin_lock(rt_hash_lock_addr(i
));
649 while ((rth
= *rthp
) != NULL
) {
650 if (rth
->u
.dst
.expires
) {
651 /* Entry is expired even if it is in use */
652 if (time_before_eq(now
, rth
->u
.dst
.expires
)) {
654 rthp
= &rth
->u
.rt_next
;
657 } else if (!rt_may_expire(rth
, tmo
, ip_rt_gc_timeout
)) {
659 rthp
= &rth
->u
.rt_next
;
663 /* Cleanup aged off entries. */
664 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
665 /* remove all related balanced entries if necessary */
666 if (rth
->u
.dst
.flags
& DST_BALANCED
) {
667 rthp
= rt_remove_balanced_route(
668 &rt_hash_table
[i
].chain
,
673 *rthp
= rth
->u
.rt_next
;
676 #else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
677 *rthp
= rth
->u
.rt_next
;
679 #endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
681 spin_unlock(rt_hash_lock_addr(i
));
683 /* Fallback loop breaker. */
684 if (time_after(jiffies
, now
))
688 mod_timer(&rt_periodic_timer
, jiffies
+ ip_rt_gc_interval
);
691 /* This can run from both BH and non-BH contexts, the latter
692 * in the case of a forced flush event.
694 static void rt_run_flush(unsigned long dummy
)
697 struct rtable
*rth
, *next
;
701 get_random_bytes(&rt_hash_rnd
, 4);
703 for (i
= rt_hash_mask
; i
>= 0; i
--) {
704 spin_lock_bh(rt_hash_lock_addr(i
));
705 rth
= rt_hash_table
[i
].chain
;
707 rt_hash_table
[i
].chain
= NULL
;
708 spin_unlock_bh(rt_hash_lock_addr(i
));
710 for (; rth
; rth
= next
) {
711 next
= rth
->u
.rt_next
;
717 static DEFINE_SPINLOCK(rt_flush_lock
);
719 void rt_cache_flush(int delay
)
721 unsigned long now
= jiffies
;
722 int user_mode
= !in_softirq();
725 delay
= ip_rt_min_delay
;
727 /* flush existing multipath state*/
730 spin_lock_bh(&rt_flush_lock
);
732 if (del_timer(&rt_flush_timer
) && delay
> 0 && rt_deadline
) {
733 long tmo
= (long)(rt_deadline
- now
);
735 /* If flush timer is already running
736 and flush request is not immediate (delay > 0):
738 if deadline is not achieved, prolongate timer to "delay",
739 otherwise fire it at deadline time.
742 if (user_mode
&& tmo
< ip_rt_max_delay
-ip_rt_min_delay
)
750 spin_unlock_bh(&rt_flush_lock
);
755 if (rt_deadline
== 0)
756 rt_deadline
= now
+ ip_rt_max_delay
;
758 mod_timer(&rt_flush_timer
, now
+delay
);
759 spin_unlock_bh(&rt_flush_lock
);
762 static void rt_secret_rebuild(unsigned long dummy
)
764 unsigned long now
= jiffies
;
767 mod_timer(&rt_secret_timer
, now
+ ip_rt_secret_interval
);
771 Short description of GC goals.
773 We want to build algorithm, which will keep routing cache
774 at some equilibrium point, when number of aged off entries
775 is kept approximately equal to newly generated ones.
777 Current expiration strength is variable "expire".
778 We try to adjust it dynamically, so that if networking
779 is idle expires is large enough to keep enough of warm entries,
780 and when load increases it reduces to limit cache size.
783 static int rt_garbage_collect(void)
785 static unsigned long expire
= RT_GC_TIMEOUT
;
786 static unsigned long last_gc
;
788 static int equilibrium
;
789 struct rtable
*rth
, **rthp
;
790 unsigned long now
= jiffies
;
794 * Garbage collection is pretty expensive,
795 * do not make it too frequently.
798 RT_CACHE_STAT_INC(gc_total
);
800 if (now
- last_gc
< ip_rt_gc_min_interval
&&
801 atomic_read(&ipv4_dst_ops
.entries
) < ip_rt_max_size
) {
802 RT_CACHE_STAT_INC(gc_ignored
);
806 /* Calculate number of entries, which we want to expire now. */
807 goal
= atomic_read(&ipv4_dst_ops
.entries
) -
808 (ip_rt_gc_elasticity
<< rt_hash_log
);
810 if (equilibrium
< ipv4_dst_ops
.gc_thresh
)
811 equilibrium
= ipv4_dst_ops
.gc_thresh
;
812 goal
= atomic_read(&ipv4_dst_ops
.entries
) - equilibrium
;
814 equilibrium
+= min_t(unsigned int, goal
/ 2, rt_hash_mask
+ 1);
815 goal
= atomic_read(&ipv4_dst_ops
.entries
) - equilibrium
;
818 /* We are in dangerous area. Try to reduce cache really
821 goal
= max_t(unsigned int, goal
/ 2, rt_hash_mask
+ 1);
822 equilibrium
= atomic_read(&ipv4_dst_ops
.entries
) - goal
;
825 if (now
- last_gc
>= ip_rt_gc_min_interval
)
836 for (i
= rt_hash_mask
, k
= rover
; i
>= 0; i
--) {
837 unsigned long tmo
= expire
;
839 k
= (k
+ 1) & rt_hash_mask
;
840 rthp
= &rt_hash_table
[k
].chain
;
841 spin_lock_bh(rt_hash_lock_addr(k
));
842 while ((rth
= *rthp
) != NULL
) {
843 if (!rt_may_expire(rth
, tmo
, expire
)) {
845 rthp
= &rth
->u
.rt_next
;
848 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
849 /* remove all related balanced entries
852 if (rth
->u
.dst
.flags
& DST_BALANCED
) {
855 rthp
= rt_remove_balanced_route(
856 &rt_hash_table
[k
].chain
,
863 *rthp
= rth
->u
.rt_next
;
867 #else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
868 *rthp
= rth
->u
.rt_next
;
871 #endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
873 spin_unlock_bh(rt_hash_lock_addr(k
));
882 /* Goal is not achieved. We stop process if:
884 - if expire reduced to zero. Otherwise, expire is halfed.
885 - if table is not full.
886 - if we are called from interrupt.
887 - jiffies check is just fallback/debug loop breaker.
888 We will not spin here for long time in any case.
891 RT_CACHE_STAT_INC(gc_goal_miss
);
897 #if RT_CACHE_DEBUG >= 2
898 printk(KERN_DEBUG
"expire>> %u %d %d %d\n", expire
,
899 atomic_read(&ipv4_dst_ops
.entries
), goal
, i
);
902 if (atomic_read(&ipv4_dst_ops
.entries
) < ip_rt_max_size
)
904 } while (!in_softirq() && time_before_eq(jiffies
, now
));
906 if (atomic_read(&ipv4_dst_ops
.entries
) < ip_rt_max_size
)
909 printk(KERN_WARNING
"dst cache overflow\n");
910 RT_CACHE_STAT_INC(gc_dst_overflow
);
914 expire
+= ip_rt_gc_min_interval
;
915 if (expire
> ip_rt_gc_timeout
||
916 atomic_read(&ipv4_dst_ops
.entries
) < ipv4_dst_ops
.gc_thresh
)
917 expire
= ip_rt_gc_timeout
;
918 #if RT_CACHE_DEBUG >= 2
919 printk(KERN_DEBUG
"expire++ %u %d %d %d\n", expire
,
920 atomic_read(&ipv4_dst_ops
.entries
), goal
, rover
);
925 static int rt_intern_hash(unsigned hash
, struct rtable
*rt
, struct rtable
**rp
)
927 struct rtable
*rth
, **rthp
;
929 struct rtable
*cand
, **candp
;
932 int attempts
= !in_softirq();
941 rthp
= &rt_hash_table
[hash
].chain
;
943 spin_lock_bh(rt_hash_lock_addr(hash
));
944 while ((rth
= *rthp
) != NULL
) {
945 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
946 if (!(rth
->u
.dst
.flags
& DST_BALANCED
) &&
947 compare_keys(&rth
->fl
, &rt
->fl
)) {
949 if (compare_keys(&rth
->fl
, &rt
->fl
)) {
952 *rthp
= rth
->u
.rt_next
;
954 * Since lookup is lockfree, the deletion
955 * must be visible to another weakly ordered CPU before
956 * the insertion at the start of the hash chain.
958 rcu_assign_pointer(rth
->u
.rt_next
,
959 rt_hash_table
[hash
].chain
);
961 * Since lookup is lockfree, the update writes
962 * must be ordered for consistency on SMP.
964 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rth
);
967 dst_hold(&rth
->u
.dst
);
968 rth
->u
.dst
.lastuse
= now
;
969 spin_unlock_bh(rt_hash_lock_addr(hash
));
976 if (!atomic_read(&rth
->u
.dst
.__refcnt
)) {
977 u32 score
= rt_score(rth
);
979 if (score
<= min_score
) {
988 rthp
= &rth
->u
.rt_next
;
992 /* ip_rt_gc_elasticity used to be average length of chain
993 * length, when exceeded gc becomes really aggressive.
995 * The second limit is less certain. At the moment it allows
996 * only 2 entries per bucket. We will see.
998 if (chain_length
> ip_rt_gc_elasticity
) {
999 *candp
= cand
->u
.rt_next
;
1004 /* Try to bind route to arp only if it is output
1005 route or unicast forwarding path.
1007 if (rt
->rt_type
== RTN_UNICAST
|| rt
->fl
.iif
== 0) {
1008 int err
= arp_bind_neighbour(&rt
->u
.dst
);
1010 spin_unlock_bh(rt_hash_lock_addr(hash
));
1012 if (err
!= -ENOBUFS
) {
1017 /* Neighbour tables are full and nothing
1018 can be released. Try to shrink route cache,
1019 it is most likely it holds some neighbour records.
1021 if (attempts
-- > 0) {
1022 int saved_elasticity
= ip_rt_gc_elasticity
;
1023 int saved_int
= ip_rt_gc_min_interval
;
1024 ip_rt_gc_elasticity
= 1;
1025 ip_rt_gc_min_interval
= 0;
1026 rt_garbage_collect();
1027 ip_rt_gc_min_interval
= saved_int
;
1028 ip_rt_gc_elasticity
= saved_elasticity
;
1032 if (net_ratelimit())
1033 printk(KERN_WARNING
"Neighbour table overflow.\n");
1039 rt
->u
.rt_next
= rt_hash_table
[hash
].chain
;
1040 #if RT_CACHE_DEBUG >= 2
1041 if (rt
->u
.rt_next
) {
1043 printk(KERN_DEBUG
"rt_cache @%02x: %u.%u.%u.%u", hash
,
1044 NIPQUAD(rt
->rt_dst
));
1045 for (trt
= rt
->u
.rt_next
; trt
; trt
= trt
->u
.rt_next
)
1046 printk(" . %u.%u.%u.%u", NIPQUAD(trt
->rt_dst
));
1050 rt_hash_table
[hash
].chain
= rt
;
1051 spin_unlock_bh(rt_hash_lock_addr(hash
));
1056 void rt_bind_peer(struct rtable
*rt
, int create
)
1058 static DEFINE_SPINLOCK(rt_peer_lock
);
1059 struct inet_peer
*peer
;
1061 peer
= inet_getpeer(rt
->rt_dst
, create
);
1063 spin_lock_bh(&rt_peer_lock
);
1064 if (rt
->peer
== NULL
) {
1068 spin_unlock_bh(&rt_peer_lock
);
1074 * Peer allocation may fail only in serious out-of-memory conditions. However
1075 * we still can generate some output.
1076 * Random ID selection looks a bit dangerous because we have no chances to
1077 * select ID being unique in a reasonable period of time.
1078 * But broken packet identifier may be better than no packet at all.
1080 static void ip_select_fb_ident(struct iphdr
*iph
)
1082 static DEFINE_SPINLOCK(ip_fb_id_lock
);
1083 static u32 ip_fallback_id
;
1086 spin_lock_bh(&ip_fb_id_lock
);
1087 salt
= secure_ip_id((__force __be32
)ip_fallback_id
^ iph
->daddr
);
1088 iph
->id
= htons(salt
& 0xFFFF);
1089 ip_fallback_id
= salt
;
1090 spin_unlock_bh(&ip_fb_id_lock
);
1093 void __ip_select_ident(struct iphdr
*iph
, struct dst_entry
*dst
, int more
)
1095 struct rtable
*rt
= (struct rtable
*) dst
;
1098 if (rt
->peer
== NULL
)
1099 rt_bind_peer(rt
, 1);
1101 /* If peer is attached to destination, it is never detached,
1102 so that we need not to grab a lock to dereference it.
1105 iph
->id
= htons(inet_getid(rt
->peer
, more
));
1109 printk(KERN_DEBUG
"rt_bind_peer(0) @%p\n",
1110 __builtin_return_address(0));
1112 ip_select_fb_ident(iph
);
1115 static void rt_del(unsigned hash
, struct rtable
*rt
)
1117 struct rtable
**rthp
;
1119 spin_lock_bh(rt_hash_lock_addr(hash
));
1121 for (rthp
= &rt_hash_table
[hash
].chain
; *rthp
;
1122 rthp
= &(*rthp
)->u
.rt_next
)
1124 *rthp
= rt
->u
.rt_next
;
1128 spin_unlock_bh(rt_hash_lock_addr(hash
));
1131 void ip_rt_redirect(__be32 old_gw
, __be32 daddr
, __be32 new_gw
,
1132 __be32 saddr
, struct net_device
*dev
)
1135 struct in_device
*in_dev
= in_dev_get(dev
);
1136 struct rtable
*rth
, **rthp
;
1137 __be32 skeys
[2] = { saddr
, 0 };
1138 int ikeys
[2] = { dev
->ifindex
, 0 };
1139 struct netevent_redirect netevent
;
1144 if (new_gw
== old_gw
|| !IN_DEV_RX_REDIRECTS(in_dev
)
1145 || MULTICAST(new_gw
) || BADCLASS(new_gw
) || ZERONET(new_gw
))
1146 goto reject_redirect
;
1148 if (!IN_DEV_SHARED_MEDIA(in_dev
)) {
1149 if (!inet_addr_onlink(in_dev
, new_gw
, old_gw
))
1150 goto reject_redirect
;
1151 if (IN_DEV_SEC_REDIRECTS(in_dev
) && ip_fib_check_default(new_gw
, dev
))
1152 goto reject_redirect
;
1154 if (inet_addr_type(new_gw
) != RTN_UNICAST
)
1155 goto reject_redirect
;
1158 for (i
= 0; i
< 2; i
++) {
1159 for (k
= 0; k
< 2; k
++) {
1160 unsigned hash
= rt_hash(daddr
, skeys
[i
], ikeys
[k
]);
1162 rthp
=&rt_hash_table
[hash
].chain
;
1165 while ((rth
= rcu_dereference(*rthp
)) != NULL
) {
1168 if (rth
->fl
.fl4_dst
!= daddr
||
1169 rth
->fl
.fl4_src
!= skeys
[i
] ||
1170 rth
->fl
.oif
!= ikeys
[k
] ||
1172 rthp
= &rth
->u
.rt_next
;
1176 if (rth
->rt_dst
!= daddr
||
1177 rth
->rt_src
!= saddr
||
1179 rth
->rt_gateway
!= old_gw
||
1180 rth
->u
.dst
.dev
!= dev
)
1183 dst_hold(&rth
->u
.dst
);
1186 rt
= dst_alloc(&ipv4_dst_ops
);
1193 /* Copy all the information. */
1195 INIT_RCU_HEAD(&rt
->u
.dst
.rcu_head
);
1196 rt
->u
.dst
.__use
= 1;
1197 atomic_set(&rt
->u
.dst
.__refcnt
, 1);
1198 rt
->u
.dst
.child
= NULL
;
1200 dev_hold(rt
->u
.dst
.dev
);
1202 in_dev_hold(rt
->idev
);
1203 rt
->u
.dst
.obsolete
= 0;
1204 rt
->u
.dst
.lastuse
= jiffies
;
1205 rt
->u
.dst
.path
= &rt
->u
.dst
;
1206 rt
->u
.dst
.neighbour
= NULL
;
1207 rt
->u
.dst
.hh
= NULL
;
1208 rt
->u
.dst
.xfrm
= NULL
;
1210 rt
->rt_flags
|= RTCF_REDIRECTED
;
1212 /* Gateway is different ... */
1213 rt
->rt_gateway
= new_gw
;
1215 /* Redirect received -> path was valid */
1216 dst_confirm(&rth
->u
.dst
);
1219 atomic_inc(&rt
->peer
->refcnt
);
1221 if (arp_bind_neighbour(&rt
->u
.dst
) ||
1222 !(rt
->u
.dst
.neighbour
->nud_state
&
1224 if (rt
->u
.dst
.neighbour
)
1225 neigh_event_send(rt
->u
.dst
.neighbour
, NULL
);
1231 netevent
.old
= &rth
->u
.dst
;
1232 netevent
.new = &rt
->u
.dst
;
1233 call_netevent_notifiers(NETEVENT_REDIRECT
,
1237 if (!rt_intern_hash(hash
, rt
, &rt
))
1250 #ifdef CONFIG_IP_ROUTE_VERBOSE
1251 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit())
1252 printk(KERN_INFO
"Redirect from %u.%u.%u.%u on %s about "
1253 "%u.%u.%u.%u ignored.\n"
1254 " Advised path = %u.%u.%u.%u -> %u.%u.%u.%u\n",
1255 NIPQUAD(old_gw
), dev
->name
, NIPQUAD(new_gw
),
1256 NIPQUAD(saddr
), NIPQUAD(daddr
));
1261 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
)
1263 struct rtable
*rt
= (struct rtable
*)dst
;
1264 struct dst_entry
*ret
= dst
;
1267 if (dst
->obsolete
) {
1270 } else if ((rt
->rt_flags
& RTCF_REDIRECTED
) ||
1271 rt
->u
.dst
.expires
) {
1272 unsigned hash
= rt_hash(rt
->fl
.fl4_dst
, rt
->fl
.fl4_src
,
1274 #if RT_CACHE_DEBUG >= 1
1275 printk(KERN_DEBUG
"ip_rt_advice: redirect to "
1276 "%u.%u.%u.%u/%02x dropped\n",
1277 NIPQUAD(rt
->rt_dst
), rt
->fl
.fl4_tos
);
1288 * 1. The first ip_rt_redirect_number redirects are sent
1289 * with exponential backoff, then we stop sending them at all,
1290 * assuming that the host ignores our redirects.
1291 * 2. If we did not see packets requiring redirects
1292 * during ip_rt_redirect_silence, we assume that the host
1293 * forgot redirected route and start to send redirects again.
1295 * This algorithm is much cheaper and more intelligent than dumb load limiting
1298 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1299 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1302 void ip_rt_send_redirect(struct sk_buff
*skb
)
1304 struct rtable
*rt
= (struct rtable
*)skb
->dst
;
1305 struct in_device
*in_dev
= in_dev_get(rt
->u
.dst
.dev
);
1310 if (!IN_DEV_TX_REDIRECTS(in_dev
))
1313 /* No redirected packets during ip_rt_redirect_silence;
1314 * reset the algorithm.
1316 if (time_after(jiffies
, rt
->u
.dst
.rate_last
+ ip_rt_redirect_silence
))
1317 rt
->u
.dst
.rate_tokens
= 0;
1319 /* Too many ignored redirects; do not send anything
1320 * set u.dst.rate_last to the last seen redirected packet.
1322 if (rt
->u
.dst
.rate_tokens
>= ip_rt_redirect_number
) {
1323 rt
->u
.dst
.rate_last
= jiffies
;
1327 /* Check for load limit; set rate_last to the latest sent
1330 if (time_after(jiffies
,
1331 (rt
->u
.dst
.rate_last
+
1332 (ip_rt_redirect_load
<< rt
->u
.dst
.rate_tokens
)))) {
1333 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, rt
->rt_gateway
);
1334 rt
->u
.dst
.rate_last
= jiffies
;
1335 ++rt
->u
.dst
.rate_tokens
;
1336 #ifdef CONFIG_IP_ROUTE_VERBOSE
1337 if (IN_DEV_LOG_MARTIANS(in_dev
) &&
1338 rt
->u
.dst
.rate_tokens
== ip_rt_redirect_number
&&
1340 printk(KERN_WARNING
"host %u.%u.%u.%u/if%d ignores "
1341 "redirects for %u.%u.%u.%u to %u.%u.%u.%u.\n",
1342 NIPQUAD(rt
->rt_src
), rt
->rt_iif
,
1343 NIPQUAD(rt
->rt_dst
), NIPQUAD(rt
->rt_gateway
));
1350 static int ip_error(struct sk_buff
*skb
)
1352 struct rtable
*rt
= (struct rtable
*)skb
->dst
;
1356 switch (rt
->u
.dst
.error
) {
1361 code
= ICMP_HOST_UNREACH
;
1364 code
= ICMP_NET_UNREACH
;
1367 code
= ICMP_PKT_FILTERED
;
1372 rt
->u
.dst
.rate_tokens
+= now
- rt
->u
.dst
.rate_last
;
1373 if (rt
->u
.dst
.rate_tokens
> ip_rt_error_burst
)
1374 rt
->u
.dst
.rate_tokens
= ip_rt_error_burst
;
1375 rt
->u
.dst
.rate_last
= now
;
1376 if (rt
->u
.dst
.rate_tokens
>= ip_rt_error_cost
) {
1377 rt
->u
.dst
.rate_tokens
-= ip_rt_error_cost
;
1378 icmp_send(skb
, ICMP_DEST_UNREACH
, code
, 0);
1381 out
: kfree_skb(skb
);
1386 * The last two values are not from the RFC but
1387 * are needed for AMPRnet AX.25 paths.
1390 static const unsigned short mtu_plateau
[] =
1391 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1393 static __inline__
unsigned short guess_mtu(unsigned short old_mtu
)
1397 for (i
= 0; i
< ARRAY_SIZE(mtu_plateau
); i
++)
1398 if (old_mtu
> mtu_plateau
[i
])
1399 return mtu_plateau
[i
];
1403 unsigned short ip_rt_frag_needed(struct iphdr
*iph
, unsigned short new_mtu
)
1406 unsigned short old_mtu
= ntohs(iph
->tot_len
);
1408 __be32 skeys
[2] = { iph
->saddr
, 0, };
1409 __be32 daddr
= iph
->daddr
;
1410 unsigned short est_mtu
= 0;
1412 if (ipv4_config
.no_pmtu_disc
)
1415 for (i
= 0; i
< 2; i
++) {
1416 unsigned hash
= rt_hash(daddr
, skeys
[i
], 0);
1419 for (rth
= rcu_dereference(rt_hash_table
[hash
].chain
); rth
;
1420 rth
= rcu_dereference(rth
->u
.rt_next
)) {
1421 if (rth
->fl
.fl4_dst
== daddr
&&
1422 rth
->fl
.fl4_src
== skeys
[i
] &&
1423 rth
->rt_dst
== daddr
&&
1424 rth
->rt_src
== iph
->saddr
&&
1426 !(dst_metric_locked(&rth
->u
.dst
, RTAX_MTU
))) {
1427 unsigned short mtu
= new_mtu
;
1429 if (new_mtu
< 68 || new_mtu
>= old_mtu
) {
1431 /* BSD 4.2 compatibility hack :-( */
1433 old_mtu
>= rth
->u
.dst
.metrics
[RTAX_MTU
-1] &&
1434 old_mtu
>= 68 + (iph
->ihl
<< 2))
1435 old_mtu
-= iph
->ihl
<< 2;
1437 mtu
= guess_mtu(old_mtu
);
1439 if (mtu
<= rth
->u
.dst
.metrics
[RTAX_MTU
-1]) {
1440 if (mtu
< rth
->u
.dst
.metrics
[RTAX_MTU
-1]) {
1441 dst_confirm(&rth
->u
.dst
);
1442 if (mtu
< ip_rt_min_pmtu
) {
1443 mtu
= ip_rt_min_pmtu
;
1444 rth
->u
.dst
.metrics
[RTAX_LOCK
-1] |=
1447 rth
->u
.dst
.metrics
[RTAX_MTU
-1] = mtu
;
1448 dst_set_expires(&rth
->u
.dst
,
1457 return est_mtu
? : new_mtu
;
1460 static void ip_rt_update_pmtu(struct dst_entry
*dst
, u32 mtu
)
1462 if (dst
->metrics
[RTAX_MTU
-1] > mtu
&& mtu
>= 68 &&
1463 !(dst_metric_locked(dst
, RTAX_MTU
))) {
1464 if (mtu
< ip_rt_min_pmtu
) {
1465 mtu
= ip_rt_min_pmtu
;
1466 dst
->metrics
[RTAX_LOCK
-1] |= (1 << RTAX_MTU
);
1468 dst
->metrics
[RTAX_MTU
-1] = mtu
;
1469 dst_set_expires(dst
, ip_rt_mtu_expires
);
1470 call_netevent_notifiers(NETEVENT_PMTU_UPDATE
, dst
);
1474 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
)
1479 static void ipv4_dst_destroy(struct dst_entry
*dst
)
1481 struct rtable
*rt
= (struct rtable
*) dst
;
1482 struct inet_peer
*peer
= rt
->peer
;
1483 struct in_device
*idev
= rt
->idev
;
1496 static void ipv4_dst_ifdown(struct dst_entry
*dst
, struct net_device
*dev
,
1499 struct rtable
*rt
= (struct rtable
*) dst
;
1500 struct in_device
*idev
= rt
->idev
;
1501 if (dev
!= &loopback_dev
&& idev
&& idev
->dev
== dev
) {
1502 struct in_device
*loopback_idev
= in_dev_get(&loopback_dev
);
1503 if (loopback_idev
) {
1504 rt
->idev
= loopback_idev
;
1510 static void ipv4_link_failure(struct sk_buff
*skb
)
1514 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_HOST_UNREACH
, 0);
1516 rt
= (struct rtable
*) skb
->dst
;
1518 dst_set_expires(&rt
->u
.dst
, 0);
1521 static int ip_rt_bug(struct sk_buff
*skb
)
1523 printk(KERN_DEBUG
"ip_rt_bug: %u.%u.%u.%u -> %u.%u.%u.%u, %s\n",
1524 NIPQUAD(skb
->nh
.iph
->saddr
), NIPQUAD(skb
->nh
.iph
->daddr
),
1525 skb
->dev
? skb
->dev
->name
: "?");
1531 We do not cache source address of outgoing interface,
1532 because it is used only by IP RR, TS and SRR options,
1533 so that it out of fast path.
1535 BTW remember: "addr" is allowed to be not aligned
1539 void ip_rt_get_source(u8
*addr
, struct rtable
*rt
)
1542 struct fib_result res
;
1544 if (rt
->fl
.iif
== 0)
1546 else if (fib_lookup(&rt
->fl
, &res
) == 0) {
1547 src
= FIB_RES_PREFSRC(res
);
1550 src
= inet_select_addr(rt
->u
.dst
.dev
, rt
->rt_gateway
,
1552 memcpy(addr
, &src
, 4);
1555 #ifdef CONFIG_NET_CLS_ROUTE
1556 static void set_class_tag(struct rtable
*rt
, u32 tag
)
1558 if (!(rt
->u
.dst
.tclassid
& 0xFFFF))
1559 rt
->u
.dst
.tclassid
|= tag
& 0xFFFF;
1560 if (!(rt
->u
.dst
.tclassid
& 0xFFFF0000))
1561 rt
->u
.dst
.tclassid
|= tag
& 0xFFFF0000;
1565 static void rt_set_nexthop(struct rtable
*rt
, struct fib_result
*res
, u32 itag
)
1567 struct fib_info
*fi
= res
->fi
;
1570 if (FIB_RES_GW(*res
) &&
1571 FIB_RES_NH(*res
).nh_scope
== RT_SCOPE_LINK
)
1572 rt
->rt_gateway
= FIB_RES_GW(*res
);
1573 memcpy(rt
->u
.dst
.metrics
, fi
->fib_metrics
,
1574 sizeof(rt
->u
.dst
.metrics
));
1575 if (fi
->fib_mtu
== 0) {
1576 rt
->u
.dst
.metrics
[RTAX_MTU
-1] = rt
->u
.dst
.dev
->mtu
;
1577 if (rt
->u
.dst
.metrics
[RTAX_LOCK
-1] & (1 << RTAX_MTU
) &&
1578 rt
->rt_gateway
!= rt
->rt_dst
&&
1579 rt
->u
.dst
.dev
->mtu
> 576)
1580 rt
->u
.dst
.metrics
[RTAX_MTU
-1] = 576;
1582 #ifdef CONFIG_NET_CLS_ROUTE
1583 rt
->u
.dst
.tclassid
= FIB_RES_NH(*res
).nh_tclassid
;
1586 rt
->u
.dst
.metrics
[RTAX_MTU
-1]= rt
->u
.dst
.dev
->mtu
;
1588 if (rt
->u
.dst
.metrics
[RTAX_HOPLIMIT
-1] == 0)
1589 rt
->u
.dst
.metrics
[RTAX_HOPLIMIT
-1] = sysctl_ip_default_ttl
;
1590 if (rt
->u
.dst
.metrics
[RTAX_MTU
-1] > IP_MAX_MTU
)
1591 rt
->u
.dst
.metrics
[RTAX_MTU
-1] = IP_MAX_MTU
;
1592 if (rt
->u
.dst
.metrics
[RTAX_ADVMSS
-1] == 0)
1593 rt
->u
.dst
.metrics
[RTAX_ADVMSS
-1] = max_t(unsigned int, rt
->u
.dst
.dev
->mtu
- 40,
1595 if (rt
->u
.dst
.metrics
[RTAX_ADVMSS
-1] > 65535 - 40)
1596 rt
->u
.dst
.metrics
[RTAX_ADVMSS
-1] = 65535 - 40;
1598 #ifdef CONFIG_NET_CLS_ROUTE
1599 #ifdef CONFIG_IP_MULTIPLE_TABLES
1600 set_class_tag(rt
, fib_rules_tclass(res
));
1602 set_class_tag(rt
, itag
);
1604 rt
->rt_type
= res
->type
;
1607 static int ip_route_input_mc(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
1608 u8 tos
, struct net_device
*dev
, int our
)
1613 struct in_device
*in_dev
= in_dev_get(dev
);
1616 /* Primary sanity checks. */
1621 if (MULTICAST(saddr
) || BADCLASS(saddr
) || LOOPBACK(saddr
) ||
1622 skb
->protocol
!= htons(ETH_P_IP
))
1625 if (ZERONET(saddr
)) {
1626 if (!LOCAL_MCAST(daddr
))
1628 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_LINK
);
1629 } else if (fib_validate_source(saddr
, 0, tos
, 0,
1630 dev
, &spec_dst
, &itag
) < 0)
1633 rth
= dst_alloc(&ipv4_dst_ops
);
1637 rth
->u
.dst
.output
= ip_rt_bug
;
1639 atomic_set(&rth
->u
.dst
.__refcnt
, 1);
1640 rth
->u
.dst
.flags
= DST_HOST
;
1641 if (in_dev
->cnf
.no_policy
)
1642 rth
->u
.dst
.flags
|= DST_NOPOLICY
;
1643 rth
->fl
.fl4_dst
= daddr
;
1644 rth
->rt_dst
= daddr
;
1645 rth
->fl
.fl4_tos
= tos
;
1646 #ifdef CONFIG_IP_ROUTE_FWMARK
1647 rth
->fl
.fl4_fwmark
= skb
->mark
;
1649 rth
->fl
.fl4_src
= saddr
;
1650 rth
->rt_src
= saddr
;
1651 #ifdef CONFIG_NET_CLS_ROUTE
1652 rth
->u
.dst
.tclassid
= itag
;
1655 rth
->fl
.iif
= dev
->ifindex
;
1656 rth
->u
.dst
.dev
= &loopback_dev
;
1657 dev_hold(rth
->u
.dst
.dev
);
1658 rth
->idev
= in_dev_get(rth
->u
.dst
.dev
);
1660 rth
->rt_gateway
= daddr
;
1661 rth
->rt_spec_dst
= spec_dst
;
1662 rth
->rt_type
= RTN_MULTICAST
;
1663 rth
->rt_flags
= RTCF_MULTICAST
;
1665 rth
->u
.dst
.input
= ip_local_deliver
;
1666 rth
->rt_flags
|= RTCF_LOCAL
;
1669 #ifdef CONFIG_IP_MROUTE
1670 if (!LOCAL_MCAST(daddr
) && IN_DEV_MFORWARD(in_dev
))
1671 rth
->u
.dst
.input
= ip_mr_input
;
1673 RT_CACHE_STAT_INC(in_slow_mc
);
1676 hash
= rt_hash(daddr
, saddr
, dev
->ifindex
);
1677 return rt_intern_hash(hash
, rth
, (struct rtable
**) &skb
->dst
);
1689 static void ip_handle_martian_source(struct net_device
*dev
,
1690 struct in_device
*in_dev
,
1691 struct sk_buff
*skb
,
1695 RT_CACHE_STAT_INC(in_martian_src
);
1696 #ifdef CONFIG_IP_ROUTE_VERBOSE
1697 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit()) {
1699 * RFC1812 recommendation, if source is martian,
1700 * the only hint is MAC header.
1702 printk(KERN_WARNING
"martian source %u.%u.%u.%u from "
1703 "%u.%u.%u.%u, on dev %s\n",
1704 NIPQUAD(daddr
), NIPQUAD(saddr
), dev
->name
);
1705 if (dev
->hard_header_len
&& skb
->mac
.raw
) {
1707 unsigned char *p
= skb
->mac
.raw
;
1708 printk(KERN_WARNING
"ll header: ");
1709 for (i
= 0; i
< dev
->hard_header_len
; i
++, p
++) {
1711 if (i
< (dev
->hard_header_len
- 1))
1720 static inline int __mkroute_input(struct sk_buff
*skb
,
1721 struct fib_result
* res
,
1722 struct in_device
*in_dev
,
1723 __be32 daddr
, __be32 saddr
, u32 tos
,
1724 struct rtable
**result
)
1729 struct in_device
*out_dev
;
1734 /* get a working reference to the output device */
1735 out_dev
= in_dev_get(FIB_RES_DEV(*res
));
1736 if (out_dev
== NULL
) {
1737 if (net_ratelimit())
1738 printk(KERN_CRIT
"Bug in ip_route_input" \
1739 "_slow(). Please, report\n");
1744 err
= fib_validate_source(saddr
, daddr
, tos
, FIB_RES_OIF(*res
),
1745 in_dev
->dev
, &spec_dst
, &itag
);
1747 ip_handle_martian_source(in_dev
->dev
, in_dev
, skb
, daddr
,
1755 flags
|= RTCF_DIRECTSRC
;
1757 if (out_dev
== in_dev
&& err
&& !(flags
& (RTCF_NAT
| RTCF_MASQ
)) &&
1758 (IN_DEV_SHARED_MEDIA(out_dev
) ||
1759 inet_addr_onlink(out_dev
, saddr
, FIB_RES_GW(*res
))))
1760 flags
|= RTCF_DOREDIRECT
;
1762 if (skb
->protocol
!= htons(ETH_P_IP
)) {
1763 /* Not IP (i.e. ARP). Do not create route, if it is
1764 * invalid for proxy arp. DNAT routes are always valid.
1766 if (out_dev
== in_dev
&& !(flags
& RTCF_DNAT
)) {
1773 rth
= dst_alloc(&ipv4_dst_ops
);
1779 atomic_set(&rth
->u
.dst
.__refcnt
, 1);
1780 rth
->u
.dst
.flags
= DST_HOST
;
1781 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
1782 if (res
->fi
->fib_nhs
> 1)
1783 rth
->u
.dst
.flags
|= DST_BALANCED
;
1785 if (in_dev
->cnf
.no_policy
)
1786 rth
->u
.dst
.flags
|= DST_NOPOLICY
;
1787 if (in_dev
->cnf
.no_xfrm
)
1788 rth
->u
.dst
.flags
|= DST_NOXFRM
;
1789 rth
->fl
.fl4_dst
= daddr
;
1790 rth
->rt_dst
= daddr
;
1791 rth
->fl
.fl4_tos
= tos
;
1792 #ifdef CONFIG_IP_ROUTE_FWMARK
1793 rth
->fl
.fl4_fwmark
= skb
->mark
;
1795 rth
->fl
.fl4_src
= saddr
;
1796 rth
->rt_src
= saddr
;
1797 rth
->rt_gateway
= daddr
;
1799 rth
->fl
.iif
= in_dev
->dev
->ifindex
;
1800 rth
->u
.dst
.dev
= (out_dev
)->dev
;
1801 dev_hold(rth
->u
.dst
.dev
);
1802 rth
->idev
= in_dev_get(rth
->u
.dst
.dev
);
1804 rth
->rt_spec_dst
= spec_dst
;
1806 rth
->u
.dst
.input
= ip_forward
;
1807 rth
->u
.dst
.output
= ip_output
;
1809 rt_set_nexthop(rth
, res
, itag
);
1811 rth
->rt_flags
= flags
;
1816 /* release the working reference to the output device */
1817 in_dev_put(out_dev
);
1821 static inline int ip_mkroute_input_def(struct sk_buff
*skb
,
1822 struct fib_result
* res
,
1823 const struct flowi
*fl
,
1824 struct in_device
*in_dev
,
1825 __be32 daddr
, __be32 saddr
, u32 tos
)
1827 struct rtable
* rth
= NULL
;
1831 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1832 if (res
->fi
&& res
->fi
->fib_nhs
> 1 && fl
->oif
== 0)
1833 fib_select_multipath(fl
, res
);
1836 /* create a routing cache entry */
1837 err
= __mkroute_input(skb
, res
, in_dev
, daddr
, saddr
, tos
, &rth
);
1841 /* put it into the cache */
1842 hash
= rt_hash(daddr
, saddr
, fl
->iif
);
1843 return rt_intern_hash(hash
, rth
, (struct rtable
**)&skb
->dst
);
1846 static inline int ip_mkroute_input(struct sk_buff
*skb
,
1847 struct fib_result
* res
,
1848 const struct flowi
*fl
,
1849 struct in_device
*in_dev
,
1850 __be32 daddr
, __be32 saddr
, u32 tos
)
1852 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
1853 struct rtable
* rth
= NULL
, *rtres
;
1854 unsigned char hop
, hopcount
;
1859 hopcount
= res
->fi
->fib_nhs
;
1863 /* distinguish between multipath and singlepath */
1865 return ip_mkroute_input_def(skb
, res
, fl
, in_dev
, daddr
,
1868 /* add all alternatives to the routing cache */
1869 for (hop
= 0; hop
< hopcount
; hop
++) {
1872 /* put reference to previous result */
1876 /* create a routing cache entry */
1877 err
= __mkroute_input(skb
, res
, in_dev
, daddr
, saddr
, tos
,
1882 /* put it into the cache */
1883 hash
= rt_hash(daddr
, saddr
, fl
->iif
);
1884 err
= rt_intern_hash(hash
, rth
, &rtres
);
1888 /* forward hop information to multipath impl. */
1889 multipath_set_nhinfo(rth
,
1890 FIB_RES_NETWORK(*res
),
1891 FIB_RES_NETMASK(*res
),
1895 skb
->dst
= &rtres
->u
.dst
;
1897 #else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
1898 return ip_mkroute_input_def(skb
, res
, fl
, in_dev
, daddr
, saddr
, tos
);
1899 #endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
1904 * NOTE. We drop all the packets that has local source
1905 * addresses, because every properly looped back packet
1906 * must have correct destination already attached by output routine.
1908 * Such approach solves two big problems:
1909 * 1. Not simplex devices are handled properly.
1910 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1913 static int ip_route_input_slow(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
1914 u8 tos
, struct net_device
*dev
)
1916 struct fib_result res
;
1917 struct in_device
*in_dev
= in_dev_get(dev
);
1918 struct flowi fl
= { .nl_u
= { .ip4_u
=
1922 .scope
= RT_SCOPE_UNIVERSE
,
1923 #ifdef CONFIG_IP_ROUTE_FWMARK
1927 .iif
= dev
->ifindex
};
1930 struct rtable
* rth
;
1936 /* IP on this device is disabled. */
1941 /* Check for the most weird martians, which can be not detected
1945 if (MULTICAST(saddr
) || BADCLASS(saddr
) || LOOPBACK(saddr
))
1946 goto martian_source
;
1948 if (daddr
== htonl(0xFFFFFFFF) || (saddr
== 0 && daddr
== 0))
1951 /* Accept zero addresses only to limited broadcast;
1952 * I even do not know to fix it or not. Waiting for complains :-)
1955 goto martian_source
;
1957 if (BADCLASS(daddr
) || ZERONET(daddr
) || LOOPBACK(daddr
))
1958 goto martian_destination
;
1961 * Now we are ready to route packet.
1963 if ((err
= fib_lookup(&fl
, &res
)) != 0) {
1964 if (!IN_DEV_FORWARD(in_dev
))
1970 RT_CACHE_STAT_INC(in_slow_tot
);
1972 if (res
.type
== RTN_BROADCAST
)
1975 if (res
.type
== RTN_LOCAL
) {
1977 result
= fib_validate_source(saddr
, daddr
, tos
,
1978 loopback_dev
.ifindex
,
1979 dev
, &spec_dst
, &itag
);
1981 goto martian_source
;
1983 flags
|= RTCF_DIRECTSRC
;
1988 if (!IN_DEV_FORWARD(in_dev
))
1990 if (res
.type
!= RTN_UNICAST
)
1991 goto martian_destination
;
1993 err
= ip_mkroute_input(skb
, &res
, &fl
, in_dev
, daddr
, saddr
, tos
);
1994 if (err
== -ENOBUFS
)
2006 if (skb
->protocol
!= htons(ETH_P_IP
))
2010 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_LINK
);
2012 err
= fib_validate_source(saddr
, 0, tos
, 0, dev
, &spec_dst
,
2015 goto martian_source
;
2017 flags
|= RTCF_DIRECTSRC
;
2019 flags
|= RTCF_BROADCAST
;
2020 res
.type
= RTN_BROADCAST
;
2021 RT_CACHE_STAT_INC(in_brd
);
2024 rth
= dst_alloc(&ipv4_dst_ops
);
2028 rth
->u
.dst
.output
= ip_rt_bug
;
2030 atomic_set(&rth
->u
.dst
.__refcnt
, 1);
2031 rth
->u
.dst
.flags
= DST_HOST
;
2032 if (in_dev
->cnf
.no_policy
)
2033 rth
->u
.dst
.flags
|= DST_NOPOLICY
;
2034 rth
->fl
.fl4_dst
= daddr
;
2035 rth
->rt_dst
= daddr
;
2036 rth
->fl
.fl4_tos
= tos
;
2037 #ifdef CONFIG_IP_ROUTE_FWMARK
2038 rth
->fl
.fl4_fwmark
= skb
->mark
;
2040 rth
->fl
.fl4_src
= saddr
;
2041 rth
->rt_src
= saddr
;
2042 #ifdef CONFIG_NET_CLS_ROUTE
2043 rth
->u
.dst
.tclassid
= itag
;
2046 rth
->fl
.iif
= dev
->ifindex
;
2047 rth
->u
.dst
.dev
= &loopback_dev
;
2048 dev_hold(rth
->u
.dst
.dev
);
2049 rth
->idev
= in_dev_get(rth
->u
.dst
.dev
);
2050 rth
->rt_gateway
= daddr
;
2051 rth
->rt_spec_dst
= spec_dst
;
2052 rth
->u
.dst
.input
= ip_local_deliver
;
2053 rth
->rt_flags
= flags
|RTCF_LOCAL
;
2054 if (res
.type
== RTN_UNREACHABLE
) {
2055 rth
->u
.dst
.input
= ip_error
;
2056 rth
->u
.dst
.error
= -err
;
2057 rth
->rt_flags
&= ~RTCF_LOCAL
;
2059 rth
->rt_type
= res
.type
;
2060 hash
= rt_hash(daddr
, saddr
, fl
.iif
);
2061 err
= rt_intern_hash(hash
, rth
, (struct rtable
**)&skb
->dst
);
2065 RT_CACHE_STAT_INC(in_no_route
);
2066 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_UNIVERSE
);
2067 res
.type
= RTN_UNREACHABLE
;
2071 * Do not cache martian addresses: they should be logged (RFC1812)
2073 martian_destination
:
2074 RT_CACHE_STAT_INC(in_martian_dst
);
2075 #ifdef CONFIG_IP_ROUTE_VERBOSE
2076 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit())
2077 printk(KERN_WARNING
"martian destination %u.%u.%u.%u from "
2078 "%u.%u.%u.%u, dev %s\n",
2079 NIPQUAD(daddr
), NIPQUAD(saddr
), dev
->name
);
2083 err
= -EHOSTUNREACH
;
2095 ip_handle_martian_source(dev
, in_dev
, skb
, daddr
, saddr
);
2099 int ip_route_input(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2100 u8 tos
, struct net_device
*dev
)
2102 struct rtable
* rth
;
2104 int iif
= dev
->ifindex
;
2106 tos
&= IPTOS_RT_MASK
;
2107 hash
= rt_hash(daddr
, saddr
, iif
);
2110 for (rth
= rcu_dereference(rt_hash_table
[hash
].chain
); rth
;
2111 rth
= rcu_dereference(rth
->u
.rt_next
)) {
2112 if (rth
->fl
.fl4_dst
== daddr
&&
2113 rth
->fl
.fl4_src
== saddr
&&
2114 rth
->fl
.iif
== iif
&&
2116 #ifdef CONFIG_IP_ROUTE_FWMARK
2117 rth
->fl
.fl4_fwmark
== skb
->mark
&&
2119 rth
->fl
.fl4_tos
== tos
) {
2120 rth
->u
.dst
.lastuse
= jiffies
;
2121 dst_hold(&rth
->u
.dst
);
2123 RT_CACHE_STAT_INC(in_hit
);
2125 skb
->dst
= (struct dst_entry
*)rth
;
2128 RT_CACHE_STAT_INC(in_hlist_search
);
2132 /* Multicast recognition logic is moved from route cache to here.
2133 The problem was that too many Ethernet cards have broken/missing
2134 hardware multicast filters :-( As result the host on multicasting
2135 network acquires a lot of useless route cache entries, sort of
2136 SDR messages from all the world. Now we try to get rid of them.
2137 Really, provided software IP multicast filter is organized
2138 reasonably (at least, hashed), it does not result in a slowdown
2139 comparing with route cache reject entries.
2140 Note, that multicast routers are not affected, because
2141 route cache entry is created eventually.
2143 if (MULTICAST(daddr
)) {
2144 struct in_device
*in_dev
;
2147 if ((in_dev
= __in_dev_get_rcu(dev
)) != NULL
) {
2148 int our
= ip_check_mc(in_dev
, daddr
, saddr
,
2149 skb
->nh
.iph
->protocol
);
2151 #ifdef CONFIG_IP_MROUTE
2152 || (!LOCAL_MCAST(daddr
) && IN_DEV_MFORWARD(in_dev
))
2156 return ip_route_input_mc(skb
, daddr
, saddr
,
2163 return ip_route_input_slow(skb
, daddr
, saddr
, tos
, dev
);
2166 static inline int __mkroute_output(struct rtable
**result
,
2167 struct fib_result
* res
,
2168 const struct flowi
*fl
,
2169 const struct flowi
*oldflp
,
2170 struct net_device
*dev_out
,
2174 struct in_device
*in_dev
;
2175 u32 tos
= RT_FL_TOS(oldflp
);
2178 if (LOOPBACK(fl
->fl4_src
) && !(dev_out
->flags
&IFF_LOOPBACK
))
2181 if (fl
->fl4_dst
== htonl(0xFFFFFFFF))
2182 res
->type
= RTN_BROADCAST
;
2183 else if (MULTICAST(fl
->fl4_dst
))
2184 res
->type
= RTN_MULTICAST
;
2185 else if (BADCLASS(fl
->fl4_dst
) || ZERONET(fl
->fl4_dst
))
2188 if (dev_out
->flags
& IFF_LOOPBACK
)
2189 flags
|= RTCF_LOCAL
;
2191 /* get work reference to inet device */
2192 in_dev
= in_dev_get(dev_out
);
2196 if (res
->type
== RTN_BROADCAST
) {
2197 flags
|= RTCF_BROADCAST
| RTCF_LOCAL
;
2199 fib_info_put(res
->fi
);
2202 } else if (res
->type
== RTN_MULTICAST
) {
2203 flags
|= RTCF_MULTICAST
|RTCF_LOCAL
;
2204 if (!ip_check_mc(in_dev
, oldflp
->fl4_dst
, oldflp
->fl4_src
,
2206 flags
&= ~RTCF_LOCAL
;
2207 /* If multicast route do not exist use
2208 default one, but do not gateway in this case.
2211 if (res
->fi
&& res
->prefixlen
< 4) {
2212 fib_info_put(res
->fi
);
2218 rth
= dst_alloc(&ipv4_dst_ops
);
2224 atomic_set(&rth
->u
.dst
.__refcnt
, 1);
2225 rth
->u
.dst
.flags
= DST_HOST
;
2226 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
2228 rth
->rt_multipath_alg
= res
->fi
->fib_mp_alg
;
2229 if (res
->fi
->fib_nhs
> 1)
2230 rth
->u
.dst
.flags
|= DST_BALANCED
;
2233 if (in_dev
->cnf
.no_xfrm
)
2234 rth
->u
.dst
.flags
|= DST_NOXFRM
;
2235 if (in_dev
->cnf
.no_policy
)
2236 rth
->u
.dst
.flags
|= DST_NOPOLICY
;
2238 rth
->fl
.fl4_dst
= oldflp
->fl4_dst
;
2239 rth
->fl
.fl4_tos
= tos
;
2240 rth
->fl
.fl4_src
= oldflp
->fl4_src
;
2241 rth
->fl
.oif
= oldflp
->oif
;
2242 #ifdef CONFIG_IP_ROUTE_FWMARK
2243 rth
->fl
.fl4_fwmark
= oldflp
->fl4_fwmark
;
2245 rth
->rt_dst
= fl
->fl4_dst
;
2246 rth
->rt_src
= fl
->fl4_src
;
2247 rth
->rt_iif
= oldflp
->oif
? : dev_out
->ifindex
;
2248 /* get references to the devices that are to be hold by the routing
2250 rth
->u
.dst
.dev
= dev_out
;
2252 rth
->idev
= in_dev_get(dev_out
);
2253 rth
->rt_gateway
= fl
->fl4_dst
;
2254 rth
->rt_spec_dst
= fl
->fl4_src
;
2256 rth
->u
.dst
.output
=ip_output
;
2258 RT_CACHE_STAT_INC(out_slow_tot
);
2260 if (flags
& RTCF_LOCAL
) {
2261 rth
->u
.dst
.input
= ip_local_deliver
;
2262 rth
->rt_spec_dst
= fl
->fl4_dst
;
2264 if (flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) {
2265 rth
->rt_spec_dst
= fl
->fl4_src
;
2266 if (flags
& RTCF_LOCAL
&&
2267 !(dev_out
->flags
& IFF_LOOPBACK
)) {
2268 rth
->u
.dst
.output
= ip_mc_output
;
2269 RT_CACHE_STAT_INC(out_slow_mc
);
2271 #ifdef CONFIG_IP_MROUTE
2272 if (res
->type
== RTN_MULTICAST
) {
2273 if (IN_DEV_MFORWARD(in_dev
) &&
2274 !LOCAL_MCAST(oldflp
->fl4_dst
)) {
2275 rth
->u
.dst
.input
= ip_mr_input
;
2276 rth
->u
.dst
.output
= ip_mc_output
;
2282 rt_set_nexthop(rth
, res
, 0);
2284 rth
->rt_flags
= flags
;
2288 /* release work reference to inet device */
2294 static inline int ip_mkroute_output_def(struct rtable
**rp
,
2295 struct fib_result
* res
,
2296 const struct flowi
*fl
,
2297 const struct flowi
*oldflp
,
2298 struct net_device
*dev_out
,
2301 struct rtable
*rth
= NULL
;
2302 int err
= __mkroute_output(&rth
, res
, fl
, oldflp
, dev_out
, flags
);
2305 hash
= rt_hash(oldflp
->fl4_dst
, oldflp
->fl4_src
, oldflp
->oif
);
2306 err
= rt_intern_hash(hash
, rth
, rp
);
2312 static inline int ip_mkroute_output(struct rtable
** rp
,
2313 struct fib_result
* res
,
2314 const struct flowi
*fl
,
2315 const struct flowi
*oldflp
,
2316 struct net_device
*dev_out
,
2319 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
2323 struct rtable
*rth
= NULL
;
2325 if (res
->fi
&& res
->fi
->fib_nhs
> 1) {
2326 unsigned char hopcount
= res
->fi
->fib_nhs
;
2328 for (hop
= 0; hop
< hopcount
; hop
++) {
2329 struct net_device
*dev2nexthop
;
2333 /* hold a work reference to the output device */
2334 dev2nexthop
= FIB_RES_DEV(*res
);
2335 dev_hold(dev2nexthop
);
2337 /* put reference to previous result */
2341 err
= __mkroute_output(&rth
, res
, fl
, oldflp
,
2342 dev2nexthop
, flags
);
2347 hash
= rt_hash(oldflp
->fl4_dst
, oldflp
->fl4_src
,
2349 err
= rt_intern_hash(hash
, rth
, rp
);
2351 /* forward hop information to multipath impl. */
2352 multipath_set_nhinfo(rth
,
2353 FIB_RES_NETWORK(*res
),
2354 FIB_RES_NETMASK(*res
),
2358 /* release work reference to output device */
2359 dev_put(dev2nexthop
);
2366 return ip_mkroute_output_def(rp
, res
, fl
, oldflp
, dev_out
,
2369 #else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
2370 return ip_mkroute_output_def(rp
, res
, fl
, oldflp
, dev_out
, flags
);
2375 * Major route resolver routine.
2378 static int ip_route_output_slow(struct rtable
**rp
, const struct flowi
*oldflp
)
2380 u32 tos
= RT_FL_TOS(oldflp
);
2381 struct flowi fl
= { .nl_u
= { .ip4_u
=
2382 { .daddr
= oldflp
->fl4_dst
,
2383 .saddr
= oldflp
->fl4_src
,
2384 .tos
= tos
& IPTOS_RT_MASK
,
2385 .scope
= ((tos
& RTO_ONLINK
) ?
2388 #ifdef CONFIG_IP_ROUTE_FWMARK
2389 .fwmark
= oldflp
->fl4_fwmark
2392 .iif
= loopback_dev
.ifindex
,
2393 .oif
= oldflp
->oif
};
2394 struct fib_result res
;
2396 struct net_device
*dev_out
= NULL
;
2402 #ifdef CONFIG_IP_MULTIPLE_TABLES
2406 if (oldflp
->fl4_src
) {
2408 if (MULTICAST(oldflp
->fl4_src
) ||
2409 BADCLASS(oldflp
->fl4_src
) ||
2410 ZERONET(oldflp
->fl4_src
))
2413 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2414 dev_out
= ip_dev_find(oldflp
->fl4_src
);
2415 if (dev_out
== NULL
)
2418 /* I removed check for oif == dev_out->oif here.
2419 It was wrong for two reasons:
2420 1. ip_dev_find(saddr) can return wrong iface, if saddr is
2421 assigned to multiple interfaces.
2422 2. Moreover, we are allowed to send packets with saddr
2423 of another iface. --ANK
2426 if (oldflp
->oif
== 0
2427 && (MULTICAST(oldflp
->fl4_dst
) || oldflp
->fl4_dst
== htonl(0xFFFFFFFF))) {
2428 /* Special hack: user can direct multicasts
2429 and limited broadcast via necessary interface
2430 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2431 This hack is not just for fun, it allows
2432 vic,vat and friends to work.
2433 They bind socket to loopback, set ttl to zero
2434 and expect that it will work.
2435 From the viewpoint of routing cache they are broken,
2436 because we are not allowed to build multicast path
2437 with loopback source addr (look, routing cache
2438 cannot know, that ttl is zero, so that packet
2439 will not leave this host and route is valid).
2440 Luckily, this hack is good workaround.
2443 fl
.oif
= dev_out
->ifindex
;
2453 dev_out
= dev_get_by_index(oldflp
->oif
);
2455 if (dev_out
== NULL
)
2458 /* RACE: Check return value of inet_select_addr instead. */
2459 if (__in_dev_get_rtnl(dev_out
) == NULL
) {
2461 goto out
; /* Wrong error code */
2464 if (LOCAL_MCAST(oldflp
->fl4_dst
) || oldflp
->fl4_dst
== htonl(0xFFFFFFFF)) {
2466 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2471 if (MULTICAST(oldflp
->fl4_dst
))
2472 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2474 else if (!oldflp
->fl4_dst
)
2475 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2481 fl
.fl4_dst
= fl
.fl4_src
;
2483 fl
.fl4_dst
= fl
.fl4_src
= htonl(INADDR_LOOPBACK
);
2486 dev_out
= &loopback_dev
;
2488 fl
.oif
= loopback_dev
.ifindex
;
2489 res
.type
= RTN_LOCAL
;
2490 flags
|= RTCF_LOCAL
;
2494 if (fib_lookup(&fl
, &res
)) {
2497 /* Apparently, routing tables are wrong. Assume,
2498 that the destination is on link.
2501 Because we are allowed to send to iface
2502 even if it has NO routes and NO assigned
2503 addresses. When oif is specified, routing
2504 tables are looked up with only one purpose:
2505 to catch if destination is gatewayed, rather than
2506 direct. Moreover, if MSG_DONTROUTE is set,
2507 we send packet, ignoring both routing tables
2508 and ifaddr state. --ANK
2511 We could make it even if oif is unknown,
2512 likely IPv6, but we do not.
2515 if (fl
.fl4_src
== 0)
2516 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2518 res
.type
= RTN_UNICAST
;
2528 if (res
.type
== RTN_LOCAL
) {
2530 fl
.fl4_src
= fl
.fl4_dst
;
2533 dev_out
= &loopback_dev
;
2535 fl
.oif
= dev_out
->ifindex
;
2537 fib_info_put(res
.fi
);
2539 flags
|= RTCF_LOCAL
;
2543 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2544 if (res
.fi
->fib_nhs
> 1 && fl
.oif
== 0)
2545 fib_select_multipath(&fl
, &res
);
2548 if (!res
.prefixlen
&& res
.type
== RTN_UNICAST
&& !fl
.oif
)
2549 fib_select_default(&fl
, &res
);
2552 fl
.fl4_src
= FIB_RES_PREFSRC(res
);
2556 dev_out
= FIB_RES_DEV(res
);
2558 fl
.oif
= dev_out
->ifindex
;
2562 err
= ip_mkroute_output(rp
, &res
, &fl
, oldflp
, dev_out
, flags
);
2572 int __ip_route_output_key(struct rtable
**rp
, const struct flowi
*flp
)
2577 hash
= rt_hash(flp
->fl4_dst
, flp
->fl4_src
, flp
->oif
);
2580 for (rth
= rcu_dereference(rt_hash_table
[hash
].chain
); rth
;
2581 rth
= rcu_dereference(rth
->u
.rt_next
)) {
2582 if (rth
->fl
.fl4_dst
== flp
->fl4_dst
&&
2583 rth
->fl
.fl4_src
== flp
->fl4_src
&&
2585 rth
->fl
.oif
== flp
->oif
&&
2586 #ifdef CONFIG_IP_ROUTE_FWMARK
2587 rth
->fl
.fl4_fwmark
== flp
->fl4_fwmark
&&
2589 !((rth
->fl
.fl4_tos
^ flp
->fl4_tos
) &
2590 (IPTOS_RT_MASK
| RTO_ONLINK
))) {
2592 /* check for multipath routes and choose one if
2595 if (multipath_select_route(flp
, rth
, rp
)) {
2596 dst_hold(&(*rp
)->u
.dst
);
2597 RT_CACHE_STAT_INC(out_hit
);
2598 rcu_read_unlock_bh();
2602 rth
->u
.dst
.lastuse
= jiffies
;
2603 dst_hold(&rth
->u
.dst
);
2605 RT_CACHE_STAT_INC(out_hit
);
2606 rcu_read_unlock_bh();
2610 RT_CACHE_STAT_INC(out_hlist_search
);
2612 rcu_read_unlock_bh();
2614 return ip_route_output_slow(rp
, flp
);
2617 EXPORT_SYMBOL_GPL(__ip_route_output_key
);
2619 int ip_route_output_flow(struct rtable
**rp
, struct flowi
*flp
, struct sock
*sk
, int flags
)
2623 if ((err
= __ip_route_output_key(rp
, flp
)) != 0)
2628 flp
->fl4_src
= (*rp
)->rt_src
;
2630 flp
->fl4_dst
= (*rp
)->rt_dst
;
2631 return xfrm_lookup((struct dst_entry
**)rp
, flp
, sk
, flags
);
2637 EXPORT_SYMBOL_GPL(ip_route_output_flow
);
2639 int ip_route_output_key(struct rtable
**rp
, struct flowi
*flp
)
2641 return ip_route_output_flow(rp
, flp
, NULL
, 0);
2644 static int rt_fill_info(struct sk_buff
*skb
, u32 pid
, u32 seq
, int event
,
2645 int nowait
, unsigned int flags
)
2647 struct rtable
*rt
= (struct rtable
*)skb
->dst
;
2649 struct nlmsghdr
*nlh
;
2650 struct rta_cacheinfo ci
;
2652 nlh
= nlmsg_put(skb
, pid
, seq
, event
, sizeof(*r
), flags
);
2656 r
= nlmsg_data(nlh
);
2657 r
->rtm_family
= AF_INET
;
2658 r
->rtm_dst_len
= 32;
2660 r
->rtm_tos
= rt
->fl
.fl4_tos
;
2661 r
->rtm_table
= RT_TABLE_MAIN
;
2662 NLA_PUT_U32(skb
, RTA_TABLE
, RT_TABLE_MAIN
);
2663 r
->rtm_type
= rt
->rt_type
;
2664 r
->rtm_scope
= RT_SCOPE_UNIVERSE
;
2665 r
->rtm_protocol
= RTPROT_UNSPEC
;
2666 r
->rtm_flags
= (rt
->rt_flags
& ~0xFFFF) | RTM_F_CLONED
;
2667 if (rt
->rt_flags
& RTCF_NOTIFY
)
2668 r
->rtm_flags
|= RTM_F_NOTIFY
;
2670 NLA_PUT_BE32(skb
, RTA_DST
, rt
->rt_dst
);
2672 if (rt
->fl
.fl4_src
) {
2673 r
->rtm_src_len
= 32;
2674 NLA_PUT_BE32(skb
, RTA_SRC
, rt
->fl
.fl4_src
);
2677 NLA_PUT_U32(skb
, RTA_OIF
, rt
->u
.dst
.dev
->ifindex
);
2678 #ifdef CONFIG_NET_CLS_ROUTE
2679 if (rt
->u
.dst
.tclassid
)
2680 NLA_PUT_U32(skb
, RTA_FLOW
, rt
->u
.dst
.tclassid
);
2682 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
2683 if (rt
->rt_multipath_alg
!= IP_MP_ALG_NONE
)
2684 NLA_PUT_U32(skb
, RTA_MP_ALGO
, rt
->rt_multipath_alg
);
2687 NLA_PUT_BE32(skb
, RTA_PREFSRC
, rt
->rt_spec_dst
);
2688 else if (rt
->rt_src
!= rt
->fl
.fl4_src
)
2689 NLA_PUT_BE32(skb
, RTA_PREFSRC
, rt
->rt_src
);
2691 if (rt
->rt_dst
!= rt
->rt_gateway
)
2692 NLA_PUT_BE32(skb
, RTA_GATEWAY
, rt
->rt_gateway
);
2694 if (rtnetlink_put_metrics(skb
, rt
->u
.dst
.metrics
) < 0)
2695 goto nla_put_failure
;
2697 ci
.rta_lastuse
= jiffies_to_clock_t(jiffies
- rt
->u
.dst
.lastuse
);
2698 ci
.rta_used
= rt
->u
.dst
.__use
;
2699 ci
.rta_clntref
= atomic_read(&rt
->u
.dst
.__refcnt
);
2700 if (rt
->u
.dst
.expires
)
2701 ci
.rta_expires
= jiffies_to_clock_t(rt
->u
.dst
.expires
- jiffies
);
2704 ci
.rta_error
= rt
->u
.dst
.error
;
2705 ci
.rta_id
= ci
.rta_ts
= ci
.rta_tsage
= 0;
2707 ci
.rta_id
= rt
->peer
->ip_id_count
;
2708 if (rt
->peer
->tcp_ts_stamp
) {
2709 ci
.rta_ts
= rt
->peer
->tcp_ts
;
2710 ci
.rta_tsage
= xtime
.tv_sec
- rt
->peer
->tcp_ts_stamp
;
2715 #ifdef CONFIG_IP_MROUTE
2716 __be32 dst
= rt
->rt_dst
;
2718 if (MULTICAST(dst
) && !LOCAL_MCAST(dst
) &&
2719 ipv4_devconf
.mc_forwarding
) {
2720 int err
= ipmr_get_route(skb
, r
, nowait
);
2725 goto nla_put_failure
;
2727 if (err
== -EMSGSIZE
)
2728 goto nla_put_failure
;
2734 NLA_PUT_U32(skb
, RTA_IIF
, rt
->fl
.iif
);
2737 NLA_PUT(skb
, RTA_CACHEINFO
, sizeof(ci
), &ci
);
2739 return nlmsg_end(skb
, nlh
);
2742 return nlmsg_cancel(skb
, nlh
);
2745 int inet_rtm_getroute(struct sk_buff
*in_skb
, struct nlmsghdr
* nlh
, void *arg
)
2748 struct nlattr
*tb
[RTA_MAX
+1];
2749 struct rtable
*rt
= NULL
;
2754 struct sk_buff
*skb
;
2756 err
= nlmsg_parse(nlh
, sizeof(*rtm
), tb
, RTA_MAX
, rtm_ipv4_policy
);
2760 rtm
= nlmsg_data(nlh
);
2762 skb
= alloc_skb(NLMSG_GOODSIZE
, GFP_KERNEL
);
2768 /* Reserve room for dummy headers, this skb can pass
2769 through good chunk of routing engine.
2771 skb
->mac
.raw
= skb
->nh
.raw
= skb
->data
;
2773 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2774 skb
->nh
.iph
->protocol
= IPPROTO_ICMP
;
2775 skb_reserve(skb
, MAX_HEADER
+ sizeof(struct iphdr
));
2777 src
= tb
[RTA_SRC
] ? nla_get_be32(tb
[RTA_SRC
]) : 0;
2778 dst
= tb
[RTA_DST
] ? nla_get_be32(tb
[RTA_DST
]) : 0;
2779 iif
= tb
[RTA_IIF
] ? nla_get_u32(tb
[RTA_IIF
]) : 0;
2782 struct net_device
*dev
;
2784 dev
= __dev_get_by_index(iif
);
2790 skb
->protocol
= htons(ETH_P_IP
);
2793 err
= ip_route_input(skb
, dst
, src
, rtm
->rtm_tos
, dev
);
2796 rt
= (struct rtable
*) skb
->dst
;
2797 if (err
== 0 && rt
->u
.dst
.error
)
2798 err
= -rt
->u
.dst
.error
;
2805 .tos
= rtm
->rtm_tos
,
2808 .oif
= tb
[RTA_OIF
] ? nla_get_u32(tb
[RTA_OIF
]) : 0,
2810 err
= ip_route_output_key(&rt
, &fl
);
2816 skb
->dst
= &rt
->u
.dst
;
2817 if (rtm
->rtm_flags
& RTM_F_NOTIFY
)
2818 rt
->rt_flags
|= RTCF_NOTIFY
;
2820 err
= rt_fill_info(skb
, NETLINK_CB(in_skb
).pid
, nlh
->nlmsg_seq
,
2821 RTM_NEWROUTE
, 0, 0);
2825 err
= rtnl_unicast(skb
, NETLINK_CB(in_skb
).pid
);
2834 int ip_rt_dump(struct sk_buff
*skb
, struct netlink_callback
*cb
)
2841 s_idx
= idx
= cb
->args
[1];
2842 for (h
= 0; h
<= rt_hash_mask
; h
++) {
2843 if (h
< s_h
) continue;
2847 for (rt
= rcu_dereference(rt_hash_table
[h
].chain
), idx
= 0; rt
;
2848 rt
= rcu_dereference(rt
->u
.rt_next
), idx
++) {
2851 skb
->dst
= dst_clone(&rt
->u
.dst
);
2852 if (rt_fill_info(skb
, NETLINK_CB(cb
->skb
).pid
,
2853 cb
->nlh
->nlmsg_seq
, RTM_NEWROUTE
,
2854 1, NLM_F_MULTI
) <= 0) {
2855 dst_release(xchg(&skb
->dst
, NULL
));
2856 rcu_read_unlock_bh();
2859 dst_release(xchg(&skb
->dst
, NULL
));
2861 rcu_read_unlock_bh();
2870 void ip_rt_multicast_event(struct in_device
*in_dev
)
2875 #ifdef CONFIG_SYSCTL
2876 static int flush_delay
;
2878 static int ipv4_sysctl_rtcache_flush(ctl_table
*ctl
, int write
,
2879 struct file
*filp
, void __user
*buffer
,
2880 size_t *lenp
, loff_t
*ppos
)
2883 proc_dointvec(ctl
, write
, filp
, buffer
, lenp
, ppos
);
2884 rt_cache_flush(flush_delay
);
2891 static int ipv4_sysctl_rtcache_flush_strategy(ctl_table
*table
,
2894 void __user
*oldval
,
2895 size_t __user
*oldlenp
,
2896 void __user
*newval
,
2901 if (newlen
!= sizeof(int))
2903 if (get_user(delay
, (int __user
*)newval
))
2905 rt_cache_flush(delay
);
2909 ctl_table ipv4_route_table
[] = {
2911 .ctl_name
= NET_IPV4_ROUTE_FLUSH
,
2912 .procname
= "flush",
2913 .data
= &flush_delay
,
2914 .maxlen
= sizeof(int),
2916 .proc_handler
= &ipv4_sysctl_rtcache_flush
,
2917 .strategy
= &ipv4_sysctl_rtcache_flush_strategy
,
2920 .ctl_name
= NET_IPV4_ROUTE_MIN_DELAY
,
2921 .procname
= "min_delay",
2922 .data
= &ip_rt_min_delay
,
2923 .maxlen
= sizeof(int),
2925 .proc_handler
= &proc_dointvec_jiffies
,
2926 .strategy
= &sysctl_jiffies
,
2929 .ctl_name
= NET_IPV4_ROUTE_MAX_DELAY
,
2930 .procname
= "max_delay",
2931 .data
= &ip_rt_max_delay
,
2932 .maxlen
= sizeof(int),
2934 .proc_handler
= &proc_dointvec_jiffies
,
2935 .strategy
= &sysctl_jiffies
,
2938 .ctl_name
= NET_IPV4_ROUTE_GC_THRESH
,
2939 .procname
= "gc_thresh",
2940 .data
= &ipv4_dst_ops
.gc_thresh
,
2941 .maxlen
= sizeof(int),
2943 .proc_handler
= &proc_dointvec
,
2946 .ctl_name
= NET_IPV4_ROUTE_MAX_SIZE
,
2947 .procname
= "max_size",
2948 .data
= &ip_rt_max_size
,
2949 .maxlen
= sizeof(int),
2951 .proc_handler
= &proc_dointvec
,
2954 /* Deprecated. Use gc_min_interval_ms */
2956 .ctl_name
= NET_IPV4_ROUTE_GC_MIN_INTERVAL
,
2957 .procname
= "gc_min_interval",
2958 .data
= &ip_rt_gc_min_interval
,
2959 .maxlen
= sizeof(int),
2961 .proc_handler
= &proc_dointvec_jiffies
,
2962 .strategy
= &sysctl_jiffies
,
2965 .ctl_name
= NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS
,
2966 .procname
= "gc_min_interval_ms",
2967 .data
= &ip_rt_gc_min_interval
,
2968 .maxlen
= sizeof(int),
2970 .proc_handler
= &proc_dointvec_ms_jiffies
,
2971 .strategy
= &sysctl_ms_jiffies
,
2974 .ctl_name
= NET_IPV4_ROUTE_GC_TIMEOUT
,
2975 .procname
= "gc_timeout",
2976 .data
= &ip_rt_gc_timeout
,
2977 .maxlen
= sizeof(int),
2979 .proc_handler
= &proc_dointvec_jiffies
,
2980 .strategy
= &sysctl_jiffies
,
2983 .ctl_name
= NET_IPV4_ROUTE_GC_INTERVAL
,
2984 .procname
= "gc_interval",
2985 .data
= &ip_rt_gc_interval
,
2986 .maxlen
= sizeof(int),
2988 .proc_handler
= &proc_dointvec_jiffies
,
2989 .strategy
= &sysctl_jiffies
,
2992 .ctl_name
= NET_IPV4_ROUTE_REDIRECT_LOAD
,
2993 .procname
= "redirect_load",
2994 .data
= &ip_rt_redirect_load
,
2995 .maxlen
= sizeof(int),
2997 .proc_handler
= &proc_dointvec
,
3000 .ctl_name
= NET_IPV4_ROUTE_REDIRECT_NUMBER
,
3001 .procname
= "redirect_number",
3002 .data
= &ip_rt_redirect_number
,
3003 .maxlen
= sizeof(int),
3005 .proc_handler
= &proc_dointvec
,
3008 .ctl_name
= NET_IPV4_ROUTE_REDIRECT_SILENCE
,
3009 .procname
= "redirect_silence",
3010 .data
= &ip_rt_redirect_silence
,
3011 .maxlen
= sizeof(int),
3013 .proc_handler
= &proc_dointvec
,
3016 .ctl_name
= NET_IPV4_ROUTE_ERROR_COST
,
3017 .procname
= "error_cost",
3018 .data
= &ip_rt_error_cost
,
3019 .maxlen
= sizeof(int),
3021 .proc_handler
= &proc_dointvec
,
3024 .ctl_name
= NET_IPV4_ROUTE_ERROR_BURST
,
3025 .procname
= "error_burst",
3026 .data
= &ip_rt_error_burst
,
3027 .maxlen
= sizeof(int),
3029 .proc_handler
= &proc_dointvec
,
3032 .ctl_name
= NET_IPV4_ROUTE_GC_ELASTICITY
,
3033 .procname
= "gc_elasticity",
3034 .data
= &ip_rt_gc_elasticity
,
3035 .maxlen
= sizeof(int),
3037 .proc_handler
= &proc_dointvec
,
3040 .ctl_name
= NET_IPV4_ROUTE_MTU_EXPIRES
,
3041 .procname
= "mtu_expires",
3042 .data
= &ip_rt_mtu_expires
,
3043 .maxlen
= sizeof(int),
3045 .proc_handler
= &proc_dointvec_jiffies
,
3046 .strategy
= &sysctl_jiffies
,
3049 .ctl_name
= NET_IPV4_ROUTE_MIN_PMTU
,
3050 .procname
= "min_pmtu",
3051 .data
= &ip_rt_min_pmtu
,
3052 .maxlen
= sizeof(int),
3054 .proc_handler
= &proc_dointvec
,
3057 .ctl_name
= NET_IPV4_ROUTE_MIN_ADVMSS
,
3058 .procname
= "min_adv_mss",
3059 .data
= &ip_rt_min_advmss
,
3060 .maxlen
= sizeof(int),
3062 .proc_handler
= &proc_dointvec
,
3065 .ctl_name
= NET_IPV4_ROUTE_SECRET_INTERVAL
,
3066 .procname
= "secret_interval",
3067 .data
= &ip_rt_secret_interval
,
3068 .maxlen
= sizeof(int),
3070 .proc_handler
= &proc_dointvec_jiffies
,
3071 .strategy
= &sysctl_jiffies
,
3077 #ifdef CONFIG_NET_CLS_ROUTE
3078 struct ip_rt_acct
*ip_rt_acct
;
3080 /* This code sucks. But you should have seen it before! --RR */
3082 /* IP route accounting ptr for this logical cpu number. */
3083 #define IP_RT_ACCT_CPU(i) (ip_rt_acct + i * 256)
3085 #ifdef CONFIG_PROC_FS
3086 static int ip_rt_acct_read(char *buffer
, char **start
, off_t offset
,
3087 int length
, int *eof
, void *data
)
3091 if ((offset
& 3) || (length
& 3))
3094 if (offset
>= sizeof(struct ip_rt_acct
) * 256) {
3099 if (offset
+ length
>= sizeof(struct ip_rt_acct
) * 256) {
3100 length
= sizeof(struct ip_rt_acct
) * 256 - offset
;
3104 offset
/= sizeof(u32
);
3107 u32
*src
= ((u32
*) IP_RT_ACCT_CPU(0)) + offset
;
3108 u32
*dst
= (u32
*) buffer
;
3110 /* Copy first cpu. */
3112 memcpy(dst
, src
, length
);
3114 /* Add the other cpus in, one int at a time */
3115 for_each_possible_cpu(i
) {
3118 src
= ((u32
*) IP_RT_ACCT_CPU(i
)) + offset
;
3120 for (j
= 0; j
< length
/4; j
++)
3126 #endif /* CONFIG_PROC_FS */
3127 #endif /* CONFIG_NET_CLS_ROUTE */
3129 static __initdata
unsigned long rhash_entries
;
3130 static int __init
set_rhash_entries(char *str
)
3134 rhash_entries
= simple_strtoul(str
, &str
, 0);
3137 __setup("rhash_entries=", set_rhash_entries
);
3139 int __init
ip_rt_init(void)
3143 rt_hash_rnd
= (int) ((num_physpages
^ (num_physpages
>>8)) ^
3144 (jiffies
^ (jiffies
>> 7)));
3146 #ifdef CONFIG_NET_CLS_ROUTE
3150 (PAGE_SIZE
<< order
) < 256 * sizeof(struct ip_rt_acct
) * NR_CPUS
; order
++)
3152 ip_rt_acct
= (struct ip_rt_acct
*)__get_free_pages(GFP_KERNEL
, order
);
3154 panic("IP: failed to allocate ip_rt_acct\n");
3155 memset(ip_rt_acct
, 0, PAGE_SIZE
<< order
);
3159 ipv4_dst_ops
.kmem_cachep
=
3160 kmem_cache_create("ip_dst_cache", sizeof(struct rtable
), 0,
3161 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
, NULL
);
3163 rt_hash_table
= (struct rt_hash_bucket
*)
3164 alloc_large_system_hash("IP route cache",
3165 sizeof(struct rt_hash_bucket
),
3167 (num_physpages
>= 128 * 1024) ?
3173 memset(rt_hash_table
, 0, (rt_hash_mask
+ 1) * sizeof(struct rt_hash_bucket
));
3174 rt_hash_lock_init();
3176 ipv4_dst_ops
.gc_thresh
= (rt_hash_mask
+ 1);
3177 ip_rt_max_size
= (rt_hash_mask
+ 1) * 16;
3182 init_timer(&rt_flush_timer
);
3183 rt_flush_timer
.function
= rt_run_flush
;
3184 init_timer(&rt_periodic_timer
);
3185 rt_periodic_timer
.function
= rt_check_expire
;
3186 init_timer(&rt_secret_timer
);
3187 rt_secret_timer
.function
= rt_secret_rebuild
;
3189 /* All the timers, started at system startup tend
3190 to synchronize. Perturb it a bit.
3192 rt_periodic_timer
.expires
= jiffies
+ net_random() % ip_rt_gc_interval
+
3194 add_timer(&rt_periodic_timer
);
3196 rt_secret_timer
.expires
= jiffies
+ net_random() % ip_rt_secret_interval
+
3197 ip_rt_secret_interval
;
3198 add_timer(&rt_secret_timer
);
3200 #ifdef CONFIG_PROC_FS
3202 struct proc_dir_entry
*rtstat_pde
= NULL
; /* keep gcc happy */
3203 if (!proc_net_fops_create("rt_cache", S_IRUGO
, &rt_cache_seq_fops
) ||
3204 !(rtstat_pde
= create_proc_entry("rt_cache", S_IRUGO
,
3208 rtstat_pde
->proc_fops
= &rt_cpu_seq_fops
;
3210 #ifdef CONFIG_NET_CLS_ROUTE
3211 create_proc_read_entry("rt_acct", 0, proc_net
, ip_rt_acct_read
, NULL
);
3221 EXPORT_SYMBOL(__ip_select_ident
);
3222 EXPORT_SYMBOL(ip_route_input
);
3223 EXPORT_SYMBOL(ip_route_output_key
);