2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * ROUTE - implementation of the IP router.
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
65 #include <linux/module.h>
66 #include <asm/uaccess.h>
67 #include <asm/system.h>
68 #include <linux/bitops.h>
69 #include <linux/types.h>
70 #include <linux/kernel.h>
72 #include <linux/bootmem.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/workqueue.h>
83 #include <linux/skbuff.h>
84 #include <linux/inetdevice.h>
85 #include <linux/igmp.h>
86 #include <linux/pkt_sched.h>
87 #include <linux/mroute.h>
88 #include <linux/netfilter_ipv4.h>
89 #include <linux/random.h>
90 #include <linux/jhash.h>
91 #include <linux/rcupdate.h>
92 #include <linux/times.h>
93 #include <linux/slab.h>
95 #include <net/net_namespace.h>
96 #include <net/protocol.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/netevent.h>
107 #include <net/rtnetlink.h>
109 #include <linux/sysctl.h>
112 #define RT_FL_TOS(oldflp4) \
113 ((u32)(oldflp4->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
115 #define IP_MAX_MTU 0xFFF0
117 #define RT_GC_TIMEOUT (300*HZ)
119 static int ip_rt_max_size
;
120 static int ip_rt_gc_timeout __read_mostly
= RT_GC_TIMEOUT
;
121 static int ip_rt_gc_interval __read_mostly
= 60 * HZ
;
122 static int ip_rt_gc_min_interval __read_mostly
= HZ
/ 2;
123 static int ip_rt_redirect_number __read_mostly
= 9;
124 static int ip_rt_redirect_load __read_mostly
= HZ
/ 50;
125 static int ip_rt_redirect_silence __read_mostly
= ((HZ
/ 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly
= HZ
;
127 static int ip_rt_error_burst __read_mostly
= 5 * HZ
;
128 static int ip_rt_gc_elasticity __read_mostly
= 8;
129 static int ip_rt_mtu_expires __read_mostly
= 10 * 60 * HZ
;
130 static int ip_rt_min_pmtu __read_mostly
= 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly
= 256;
132 static int rt_chain_length_max __read_mostly
= 20;
135 * Interface to generic destination cache.
138 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
);
139 static unsigned int ipv4_default_advmss(const struct dst_entry
*dst
);
140 static unsigned int ipv4_default_mtu(const struct dst_entry
*dst
);
141 static void ipv4_dst_destroy(struct dst_entry
*dst
);
142 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
);
143 static void ipv4_link_failure(struct sk_buff
*skb
);
144 static void ip_rt_update_pmtu(struct dst_entry
*dst
, u32 mtu
);
145 static int rt_garbage_collect(struct dst_ops
*ops
);
147 static void ipv4_dst_ifdown(struct dst_entry
*dst
, struct net_device
*dev
,
152 static u32
*ipv4_cow_metrics(struct dst_entry
*dst
, unsigned long old
)
154 struct rtable
*rt
= (struct rtable
*) dst
;
155 struct inet_peer
*peer
;
163 u32
*old_p
= __DST_METRICS_PTR(old
);
164 unsigned long prev
, new;
167 if (inet_metrics_new(peer
))
168 memcpy(p
, old_p
, sizeof(u32
) * RTAX_MAX
);
170 new = (unsigned long) p
;
171 prev
= cmpxchg(&dst
->_metrics
, old
, new);
174 p
= __DST_METRICS_PTR(prev
);
175 if (prev
& DST_METRICS_READ_ONLY
)
179 fib_info_put(rt
->fi
);
187 static struct dst_ops ipv4_dst_ops
= {
189 .protocol
= cpu_to_be16(ETH_P_IP
),
190 .gc
= rt_garbage_collect
,
191 .check
= ipv4_dst_check
,
192 .default_advmss
= ipv4_default_advmss
,
193 .default_mtu
= ipv4_default_mtu
,
194 .cow_metrics
= ipv4_cow_metrics
,
195 .destroy
= ipv4_dst_destroy
,
196 .ifdown
= ipv4_dst_ifdown
,
197 .negative_advice
= ipv4_negative_advice
,
198 .link_failure
= ipv4_link_failure
,
199 .update_pmtu
= ip_rt_update_pmtu
,
200 .local_out
= __ip_local_out
,
203 #define ECN_OR_COST(class) TC_PRIO_##class
205 const __u8 ip_tos2prio
[16] = {
207 ECN_OR_COST(BESTEFFORT
),
209 ECN_OR_COST(BESTEFFORT
),
215 ECN_OR_COST(INTERACTIVE
),
217 ECN_OR_COST(INTERACTIVE
),
218 TC_PRIO_INTERACTIVE_BULK
,
219 ECN_OR_COST(INTERACTIVE_BULK
),
220 TC_PRIO_INTERACTIVE_BULK
,
221 ECN_OR_COST(INTERACTIVE_BULK
)
229 /* The locking scheme is rather straight forward:
231 * 1) Read-Copy Update protects the buckets of the central route hash.
232 * 2) Only writers remove entries, and they hold the lock
233 * as they look at rtable reference counts.
234 * 3) Only readers acquire references to rtable entries,
235 * they do so with atomic increments and with the
239 struct rt_hash_bucket
{
240 struct rtable __rcu
*chain
;
243 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
244 defined(CONFIG_PROVE_LOCKING)
246 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
247 * The size of this table is a power of two and depends on the number of CPUS.
248 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
250 #ifdef CONFIG_LOCKDEP
251 # define RT_HASH_LOCK_SZ 256
254 # define RT_HASH_LOCK_SZ 4096
256 # define RT_HASH_LOCK_SZ 2048
258 # define RT_HASH_LOCK_SZ 1024
260 # define RT_HASH_LOCK_SZ 512
262 # define RT_HASH_LOCK_SZ 256
266 static spinlock_t
*rt_hash_locks
;
267 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
269 static __init
void rt_hash_lock_init(void)
273 rt_hash_locks
= kmalloc(sizeof(spinlock_t
) * RT_HASH_LOCK_SZ
,
276 panic("IP: failed to allocate rt_hash_locks\n");
278 for (i
= 0; i
< RT_HASH_LOCK_SZ
; i
++)
279 spin_lock_init(&rt_hash_locks
[i
]);
282 # define rt_hash_lock_addr(slot) NULL
284 static inline void rt_hash_lock_init(void)
289 static struct rt_hash_bucket
*rt_hash_table __read_mostly
;
290 static unsigned rt_hash_mask __read_mostly
;
291 static unsigned int rt_hash_log __read_mostly
;
293 static DEFINE_PER_CPU(struct rt_cache_stat
, rt_cache_stat
);
294 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
296 static inline unsigned int rt_hash(__be32 daddr
, __be32 saddr
, int idx
,
299 return jhash_3words((__force u32
)daddr
, (__force u32
)saddr
,
304 static inline int rt_genid(struct net
*net
)
306 return atomic_read(&net
->ipv4
.rt_genid
);
309 #ifdef CONFIG_PROC_FS
310 struct rt_cache_iter_state
{
311 struct seq_net_private p
;
316 static struct rtable
*rt_cache_get_first(struct seq_file
*seq
)
318 struct rt_cache_iter_state
*st
= seq
->private;
319 struct rtable
*r
= NULL
;
321 for (st
->bucket
= rt_hash_mask
; st
->bucket
>= 0; --st
->bucket
) {
322 if (!rcu_dereference_raw(rt_hash_table
[st
->bucket
].chain
))
325 r
= rcu_dereference_bh(rt_hash_table
[st
->bucket
].chain
);
327 if (dev_net(r
->dst
.dev
) == seq_file_net(seq
) &&
328 r
->rt_genid
== st
->genid
)
330 r
= rcu_dereference_bh(r
->dst
.rt_next
);
332 rcu_read_unlock_bh();
337 static struct rtable
*__rt_cache_get_next(struct seq_file
*seq
,
340 struct rt_cache_iter_state
*st
= seq
->private;
342 r
= rcu_dereference_bh(r
->dst
.rt_next
);
344 rcu_read_unlock_bh();
346 if (--st
->bucket
< 0)
348 } while (!rcu_dereference_raw(rt_hash_table
[st
->bucket
].chain
));
350 r
= rcu_dereference_bh(rt_hash_table
[st
->bucket
].chain
);
355 static struct rtable
*rt_cache_get_next(struct seq_file
*seq
,
358 struct rt_cache_iter_state
*st
= seq
->private;
359 while ((r
= __rt_cache_get_next(seq
, r
)) != NULL
) {
360 if (dev_net(r
->dst
.dev
) != seq_file_net(seq
))
362 if (r
->rt_genid
== st
->genid
)
368 static struct rtable
*rt_cache_get_idx(struct seq_file
*seq
, loff_t pos
)
370 struct rtable
*r
= rt_cache_get_first(seq
);
373 while (pos
&& (r
= rt_cache_get_next(seq
, r
)))
375 return pos
? NULL
: r
;
378 static void *rt_cache_seq_start(struct seq_file
*seq
, loff_t
*pos
)
380 struct rt_cache_iter_state
*st
= seq
->private;
382 return rt_cache_get_idx(seq
, *pos
- 1);
383 st
->genid
= rt_genid(seq_file_net(seq
));
384 return SEQ_START_TOKEN
;
387 static void *rt_cache_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
391 if (v
== SEQ_START_TOKEN
)
392 r
= rt_cache_get_first(seq
);
394 r
= rt_cache_get_next(seq
, v
);
399 static void rt_cache_seq_stop(struct seq_file
*seq
, void *v
)
401 if (v
&& v
!= SEQ_START_TOKEN
)
402 rcu_read_unlock_bh();
405 static int rt_cache_seq_show(struct seq_file
*seq
, void *v
)
407 if (v
== SEQ_START_TOKEN
)
408 seq_printf(seq
, "%-127s\n",
409 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
410 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
413 struct rtable
*r
= v
;
416 seq_printf(seq
, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
417 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
418 r
->dst
.dev
? r
->dst
.dev
->name
: "*",
419 (__force u32
)r
->rt_dst
,
420 (__force u32
)r
->rt_gateway
,
421 r
->rt_flags
, atomic_read(&r
->dst
.__refcnt
),
422 r
->dst
.__use
, 0, (__force u32
)r
->rt_src
,
423 dst_metric_advmss(&r
->dst
) + 40,
424 dst_metric(&r
->dst
, RTAX_WINDOW
),
425 (int)((dst_metric(&r
->dst
, RTAX_RTT
) >> 3) +
426 dst_metric(&r
->dst
, RTAX_RTTVAR
)),
428 r
->dst
.hh
? atomic_read(&r
->dst
.hh
->hh_refcnt
) : -1,
429 r
->dst
.hh
? (r
->dst
.hh
->hh_output
==
431 r
->rt_spec_dst
, &len
);
433 seq_printf(seq
, "%*s\n", 127 - len
, "");
438 static const struct seq_operations rt_cache_seq_ops
= {
439 .start
= rt_cache_seq_start
,
440 .next
= rt_cache_seq_next
,
441 .stop
= rt_cache_seq_stop
,
442 .show
= rt_cache_seq_show
,
445 static int rt_cache_seq_open(struct inode
*inode
, struct file
*file
)
447 return seq_open_net(inode
, file
, &rt_cache_seq_ops
,
448 sizeof(struct rt_cache_iter_state
));
451 static const struct file_operations rt_cache_seq_fops
= {
452 .owner
= THIS_MODULE
,
453 .open
= rt_cache_seq_open
,
456 .release
= seq_release_net
,
460 static void *rt_cpu_seq_start(struct seq_file
*seq
, loff_t
*pos
)
465 return SEQ_START_TOKEN
;
467 for (cpu
= *pos
-1; cpu
< nr_cpu_ids
; ++cpu
) {
468 if (!cpu_possible(cpu
))
471 return &per_cpu(rt_cache_stat
, cpu
);
476 static void *rt_cpu_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
480 for (cpu
= *pos
; cpu
< nr_cpu_ids
; ++cpu
) {
481 if (!cpu_possible(cpu
))
484 return &per_cpu(rt_cache_stat
, cpu
);
490 static void rt_cpu_seq_stop(struct seq_file
*seq
, void *v
)
495 static int rt_cpu_seq_show(struct seq_file
*seq
, void *v
)
497 struct rt_cache_stat
*st
= v
;
499 if (v
== SEQ_START_TOKEN
) {
500 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");
504 seq_printf(seq
,"%08x %08x %08x %08x %08x %08x %08x %08x "
505 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
506 dst_entries_get_slow(&ipv4_dst_ops
),
529 static const struct seq_operations rt_cpu_seq_ops
= {
530 .start
= rt_cpu_seq_start
,
531 .next
= rt_cpu_seq_next
,
532 .stop
= rt_cpu_seq_stop
,
533 .show
= rt_cpu_seq_show
,
537 static int rt_cpu_seq_open(struct inode
*inode
, struct file
*file
)
539 return seq_open(file
, &rt_cpu_seq_ops
);
542 static const struct file_operations rt_cpu_seq_fops
= {
543 .owner
= THIS_MODULE
,
544 .open
= rt_cpu_seq_open
,
547 .release
= seq_release
,
550 #ifdef CONFIG_IP_ROUTE_CLASSID
551 static int rt_acct_proc_show(struct seq_file
*m
, void *v
)
553 struct ip_rt_acct
*dst
, *src
;
556 dst
= kcalloc(256, sizeof(struct ip_rt_acct
), GFP_KERNEL
);
560 for_each_possible_cpu(i
) {
561 src
= (struct ip_rt_acct
*)per_cpu_ptr(ip_rt_acct
, i
);
562 for (j
= 0; j
< 256; j
++) {
563 dst
[j
].o_bytes
+= src
[j
].o_bytes
;
564 dst
[j
].o_packets
+= src
[j
].o_packets
;
565 dst
[j
].i_bytes
+= src
[j
].i_bytes
;
566 dst
[j
].i_packets
+= src
[j
].i_packets
;
570 seq_write(m
, dst
, 256 * sizeof(struct ip_rt_acct
));
575 static int rt_acct_proc_open(struct inode
*inode
, struct file
*file
)
577 return single_open(file
, rt_acct_proc_show
, NULL
);
580 static const struct file_operations rt_acct_proc_fops
= {
581 .owner
= THIS_MODULE
,
582 .open
= rt_acct_proc_open
,
585 .release
= single_release
,
589 static int __net_init
ip_rt_do_proc_init(struct net
*net
)
591 struct proc_dir_entry
*pde
;
593 pde
= proc_net_fops_create(net
, "rt_cache", S_IRUGO
,
598 pde
= proc_create("rt_cache", S_IRUGO
,
599 net
->proc_net_stat
, &rt_cpu_seq_fops
);
603 #ifdef CONFIG_IP_ROUTE_CLASSID
604 pde
= proc_create("rt_acct", 0, net
->proc_net
, &rt_acct_proc_fops
);
610 #ifdef CONFIG_IP_ROUTE_CLASSID
612 remove_proc_entry("rt_cache", net
->proc_net_stat
);
615 remove_proc_entry("rt_cache", net
->proc_net
);
620 static void __net_exit
ip_rt_do_proc_exit(struct net
*net
)
622 remove_proc_entry("rt_cache", net
->proc_net_stat
);
623 remove_proc_entry("rt_cache", net
->proc_net
);
624 #ifdef CONFIG_IP_ROUTE_CLASSID
625 remove_proc_entry("rt_acct", net
->proc_net
);
629 static struct pernet_operations ip_rt_proc_ops __net_initdata
= {
630 .init
= ip_rt_do_proc_init
,
631 .exit
= ip_rt_do_proc_exit
,
634 static int __init
ip_rt_proc_init(void)
636 return register_pernet_subsys(&ip_rt_proc_ops
);
640 static inline int ip_rt_proc_init(void)
644 #endif /* CONFIG_PROC_FS */
646 static inline void rt_free(struct rtable
*rt
)
648 call_rcu_bh(&rt
->dst
.rcu_head
, dst_rcu_free
);
651 static inline void rt_drop(struct rtable
*rt
)
654 call_rcu_bh(&rt
->dst
.rcu_head
, dst_rcu_free
);
657 static inline int rt_fast_clean(struct rtable
*rth
)
659 /* Kill broadcast/multicast entries very aggresively, if they
660 collide in hash table with more useful entries */
661 return (rth
->rt_flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) &&
662 rt_is_input_route(rth
) && rth
->dst
.rt_next
;
665 static inline int rt_valuable(struct rtable
*rth
)
667 return (rth
->rt_flags
& (RTCF_REDIRECTED
| RTCF_NOTIFY
)) ||
668 (rth
->peer
&& rth
->peer
->pmtu_expires
);
671 static int rt_may_expire(struct rtable
*rth
, unsigned long tmo1
, unsigned long tmo2
)
676 if (atomic_read(&rth
->dst
.__refcnt
))
679 age
= jiffies
- rth
->dst
.lastuse
;
680 if ((age
<= tmo1
&& !rt_fast_clean(rth
)) ||
681 (age
<= tmo2
&& rt_valuable(rth
)))
687 /* Bits of score are:
689 * 30: not quite useless
690 * 29..0: usage counter
692 static inline u32
rt_score(struct rtable
*rt
)
694 u32 score
= jiffies
- rt
->dst
.lastuse
;
696 score
= ~score
& ~(3<<30);
701 if (rt_is_output_route(rt
) ||
702 !(rt
->rt_flags
& (RTCF_BROADCAST
|RTCF_MULTICAST
|RTCF_LOCAL
)))
708 static inline bool rt_caching(const struct net
*net
)
710 return net
->ipv4
.current_rt_cache_rebuild_count
<=
711 net
->ipv4
.sysctl_rt_cache_rebuild_count
;
714 static inline bool compare_hash_inputs(const struct rtable
*rt1
,
715 const struct rtable
*rt2
)
717 return ((((__force u32
)rt1
->rt_key_dst
^ (__force u32
)rt2
->rt_key_dst
) |
718 ((__force u32
)rt1
->rt_key_src
^ (__force u32
)rt2
->rt_key_src
) |
719 (rt1
->rt_iif
^ rt2
->rt_iif
)) == 0);
722 static inline int compare_keys(struct rtable
*rt1
, struct rtable
*rt2
)
724 return (((__force u32
)rt1
->rt_key_dst
^ (__force u32
)rt2
->rt_key_dst
) |
725 ((__force u32
)rt1
->rt_key_src
^ (__force u32
)rt2
->rt_key_src
) |
726 (rt1
->rt_mark
^ rt2
->rt_mark
) |
727 (rt1
->rt_key_tos
^ rt2
->rt_key_tos
) |
728 (rt1
->rt_oif
^ rt2
->rt_oif
) |
729 (rt1
->rt_iif
^ rt2
->rt_iif
)) == 0;
732 static inline int compare_netns(struct rtable
*rt1
, struct rtable
*rt2
)
734 return net_eq(dev_net(rt1
->dst
.dev
), dev_net(rt2
->dst
.dev
));
737 static inline int rt_is_expired(struct rtable
*rth
)
739 return rth
->rt_genid
!= rt_genid(dev_net(rth
->dst
.dev
));
743 * Perform a full scan of hash table and free all entries.
744 * Can be called by a softirq or a process.
745 * In the later case, we want to be reschedule if necessary
747 static void rt_do_flush(struct net
*net
, int process_context
)
750 struct rtable
*rth
, *next
;
752 for (i
= 0; i
<= rt_hash_mask
; i
++) {
753 struct rtable __rcu
**pprev
;
756 if (process_context
&& need_resched())
758 rth
= rcu_dereference_raw(rt_hash_table
[i
].chain
);
762 spin_lock_bh(rt_hash_lock_addr(i
));
765 pprev
= &rt_hash_table
[i
].chain
;
766 rth
= rcu_dereference_protected(*pprev
,
767 lockdep_is_held(rt_hash_lock_addr(i
)));
770 next
= rcu_dereference_protected(rth
->dst
.rt_next
,
771 lockdep_is_held(rt_hash_lock_addr(i
)));
774 net_eq(dev_net(rth
->dst
.dev
), net
)) {
775 rcu_assign_pointer(*pprev
, next
);
776 rcu_assign_pointer(rth
->dst
.rt_next
, list
);
779 pprev
= &rth
->dst
.rt_next
;
784 spin_unlock_bh(rt_hash_lock_addr(i
));
786 for (; list
; list
= next
) {
787 next
= rcu_dereference_protected(list
->dst
.rt_next
, 1);
794 * While freeing expired entries, we compute average chain length
795 * and standard deviation, using fixed-point arithmetic.
796 * This to have an estimation of rt_chain_length_max
797 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
798 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
802 #define ONE (1UL << FRACT_BITS)
805 * Given a hash chain and an item in this hash chain,
806 * find if a previous entry has the same hash_inputs
807 * (but differs on tos, mark or oif)
808 * Returns 0 if an alias is found.
809 * Returns ONE if rth has no alias before itself.
811 static int has_noalias(const struct rtable
*head
, const struct rtable
*rth
)
813 const struct rtable
*aux
= head
;
816 if (compare_hash_inputs(aux
, rth
))
818 aux
= rcu_dereference_protected(aux
->dst
.rt_next
, 1);
824 * Perturbation of rt_genid by a small quantity [1..256]
825 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
826 * many times (2^24) without giving recent rt_genid.
827 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
829 static void rt_cache_invalidate(struct net
*net
)
831 unsigned char shuffle
;
833 get_random_bytes(&shuffle
, sizeof(shuffle
));
834 atomic_add(shuffle
+ 1U, &net
->ipv4
.rt_genid
);
838 * delay < 0 : invalidate cache (fast : entries will be deleted later)
839 * delay >= 0 : invalidate & flush cache (can be long)
841 void rt_cache_flush(struct net
*net
, int delay
)
843 rt_cache_invalidate(net
);
845 rt_do_flush(net
, !in_softirq());
848 /* Flush previous cache invalidated entries from the cache */
849 void rt_cache_flush_batch(struct net
*net
)
851 rt_do_flush(net
, !in_softirq());
854 static void rt_emergency_hash_rebuild(struct net
*net
)
857 printk(KERN_WARNING
"Route hash chain too long!\n");
858 rt_cache_invalidate(net
);
862 Short description of GC goals.
864 We want to build algorithm, which will keep routing cache
865 at some equilibrium point, when number of aged off entries
866 is kept approximately equal to newly generated ones.
868 Current expiration strength is variable "expire".
869 We try to adjust it dynamically, so that if networking
870 is idle expires is large enough to keep enough of warm entries,
871 and when load increases it reduces to limit cache size.
874 static int rt_garbage_collect(struct dst_ops
*ops
)
876 static unsigned long expire
= RT_GC_TIMEOUT
;
877 static unsigned long last_gc
;
879 static int equilibrium
;
881 struct rtable __rcu
**rthp
;
882 unsigned long now
= jiffies
;
884 int entries
= dst_entries_get_fast(&ipv4_dst_ops
);
887 * Garbage collection is pretty expensive,
888 * do not make it too frequently.
891 RT_CACHE_STAT_INC(gc_total
);
893 if (now
- last_gc
< ip_rt_gc_min_interval
&&
894 entries
< ip_rt_max_size
) {
895 RT_CACHE_STAT_INC(gc_ignored
);
899 entries
= dst_entries_get_slow(&ipv4_dst_ops
);
900 /* Calculate number of entries, which we want to expire now. */
901 goal
= entries
- (ip_rt_gc_elasticity
<< rt_hash_log
);
903 if (equilibrium
< ipv4_dst_ops
.gc_thresh
)
904 equilibrium
= ipv4_dst_ops
.gc_thresh
;
905 goal
= entries
- equilibrium
;
907 equilibrium
+= min_t(unsigned int, goal
>> 1, rt_hash_mask
+ 1);
908 goal
= entries
- equilibrium
;
911 /* We are in dangerous area. Try to reduce cache really
914 goal
= max_t(unsigned int, goal
>> 1, rt_hash_mask
+ 1);
915 equilibrium
= entries
- goal
;
918 if (now
- last_gc
>= ip_rt_gc_min_interval
)
929 for (i
= rt_hash_mask
, k
= rover
; i
>= 0; i
--) {
930 unsigned long tmo
= expire
;
932 k
= (k
+ 1) & rt_hash_mask
;
933 rthp
= &rt_hash_table
[k
].chain
;
934 spin_lock_bh(rt_hash_lock_addr(k
));
935 while ((rth
= rcu_dereference_protected(*rthp
,
936 lockdep_is_held(rt_hash_lock_addr(k
)))) != NULL
) {
937 if (!rt_is_expired(rth
) &&
938 !rt_may_expire(rth
, tmo
, expire
)) {
940 rthp
= &rth
->dst
.rt_next
;
943 *rthp
= rth
->dst
.rt_next
;
947 spin_unlock_bh(rt_hash_lock_addr(k
));
956 /* Goal is not achieved. We stop process if:
958 - if expire reduced to zero. Otherwise, expire is halfed.
959 - if table is not full.
960 - if we are called from interrupt.
961 - jiffies check is just fallback/debug loop breaker.
962 We will not spin here for long time in any case.
965 RT_CACHE_STAT_INC(gc_goal_miss
);
972 if (dst_entries_get_fast(&ipv4_dst_ops
) < ip_rt_max_size
)
974 } while (!in_softirq() && time_before_eq(jiffies
, now
));
976 if (dst_entries_get_fast(&ipv4_dst_ops
) < ip_rt_max_size
)
978 if (dst_entries_get_slow(&ipv4_dst_ops
) < ip_rt_max_size
)
981 printk(KERN_WARNING
"dst cache overflow\n");
982 RT_CACHE_STAT_INC(gc_dst_overflow
);
986 expire
+= ip_rt_gc_min_interval
;
987 if (expire
> ip_rt_gc_timeout
||
988 dst_entries_get_fast(&ipv4_dst_ops
) < ipv4_dst_ops
.gc_thresh
||
989 dst_entries_get_slow(&ipv4_dst_ops
) < ipv4_dst_ops
.gc_thresh
)
990 expire
= ip_rt_gc_timeout
;
995 * Returns number of entries in a hash chain that have different hash_inputs
997 static int slow_chain_length(const struct rtable
*head
)
1000 const struct rtable
*rth
= head
;
1003 length
+= has_noalias(head
, rth
);
1004 rth
= rcu_dereference_protected(rth
->dst
.rt_next
, 1);
1006 return length
>> FRACT_BITS
;
1009 static struct rtable
*rt_intern_hash(unsigned hash
, struct rtable
*rt
,
1010 struct sk_buff
*skb
, int ifindex
)
1012 struct rtable
*rth
, *cand
;
1013 struct rtable __rcu
**rthp
, **candp
;
1017 int attempts
= !in_softirq();
1021 min_score
= ~(u32
)0;
1026 if (!rt_caching(dev_net(rt
->dst
.dev
))) {
1028 * If we're not caching, just tell the caller we
1029 * were successful and don't touch the route. The
1030 * caller hold the sole reference to the cache entry, and
1031 * it will be released when the caller is done with it.
1032 * If we drop it here, the callers have no way to resolve routes
1033 * when we're not caching. Instead, just point *rp at rt, so
1034 * the caller gets a single use out of the route
1035 * Note that we do rt_free on this new route entry, so that
1036 * once its refcount hits zero, we are still able to reap it
1038 * Note: To avoid expensive rcu stuff for this uncached dst,
1039 * we set DST_NOCACHE so that dst_release() can free dst without
1040 * waiting a grace period.
1043 rt
->dst
.flags
|= DST_NOCACHE
;
1044 if (rt
->rt_type
== RTN_UNICAST
|| rt_is_output_route(rt
)) {
1045 int err
= arp_bind_neighbour(&rt
->dst
);
1047 if (net_ratelimit())
1049 "Neighbour table failure & not caching routes.\n");
1051 return ERR_PTR(err
);
1058 rthp
= &rt_hash_table
[hash
].chain
;
1060 spin_lock_bh(rt_hash_lock_addr(hash
));
1061 while ((rth
= rcu_dereference_protected(*rthp
,
1062 lockdep_is_held(rt_hash_lock_addr(hash
)))) != NULL
) {
1063 if (rt_is_expired(rth
)) {
1064 *rthp
= rth
->dst
.rt_next
;
1068 if (compare_keys(rth
, rt
) && compare_netns(rth
, rt
)) {
1070 *rthp
= rth
->dst
.rt_next
;
1072 * Since lookup is lockfree, the deletion
1073 * must be visible to another weakly ordered CPU before
1074 * the insertion at the start of the hash chain.
1076 rcu_assign_pointer(rth
->dst
.rt_next
,
1077 rt_hash_table
[hash
].chain
);
1079 * Since lookup is lockfree, the update writes
1080 * must be ordered for consistency on SMP.
1082 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rth
);
1084 dst_use(&rth
->dst
, now
);
1085 spin_unlock_bh(rt_hash_lock_addr(hash
));
1089 skb_dst_set(skb
, &rth
->dst
);
1093 if (!atomic_read(&rth
->dst
.__refcnt
)) {
1094 u32 score
= rt_score(rth
);
1096 if (score
<= min_score
) {
1105 rthp
= &rth
->dst
.rt_next
;
1109 /* ip_rt_gc_elasticity used to be average length of chain
1110 * length, when exceeded gc becomes really aggressive.
1112 * The second limit is less certain. At the moment it allows
1113 * only 2 entries per bucket. We will see.
1115 if (chain_length
> ip_rt_gc_elasticity
) {
1116 *candp
= cand
->dst
.rt_next
;
1120 if (chain_length
> rt_chain_length_max
&&
1121 slow_chain_length(rt_hash_table
[hash
].chain
) > rt_chain_length_max
) {
1122 struct net
*net
= dev_net(rt
->dst
.dev
);
1123 int num
= ++net
->ipv4
.current_rt_cache_rebuild_count
;
1124 if (!rt_caching(net
)) {
1125 printk(KERN_WARNING
"%s: %d rebuilds is over limit, route caching disabled\n",
1126 rt
->dst
.dev
->name
, num
);
1128 rt_emergency_hash_rebuild(net
);
1129 spin_unlock_bh(rt_hash_lock_addr(hash
));
1131 hash
= rt_hash(rt
->rt_key_dst
, rt
->rt_key_src
,
1132 ifindex
, rt_genid(net
));
1137 /* Try to bind route to arp only if it is output
1138 route or unicast forwarding path.
1140 if (rt
->rt_type
== RTN_UNICAST
|| rt_is_output_route(rt
)) {
1141 int err
= arp_bind_neighbour(&rt
->dst
);
1143 spin_unlock_bh(rt_hash_lock_addr(hash
));
1145 if (err
!= -ENOBUFS
) {
1147 return ERR_PTR(err
);
1150 /* Neighbour tables are full and nothing
1151 can be released. Try to shrink route cache,
1152 it is most likely it holds some neighbour records.
1154 if (attempts
-- > 0) {
1155 int saved_elasticity
= ip_rt_gc_elasticity
;
1156 int saved_int
= ip_rt_gc_min_interval
;
1157 ip_rt_gc_elasticity
= 1;
1158 ip_rt_gc_min_interval
= 0;
1159 rt_garbage_collect(&ipv4_dst_ops
);
1160 ip_rt_gc_min_interval
= saved_int
;
1161 ip_rt_gc_elasticity
= saved_elasticity
;
1165 if (net_ratelimit())
1166 printk(KERN_WARNING
"ipv4: Neighbour table overflow.\n");
1168 return ERR_PTR(-ENOBUFS
);
1172 rt
->dst
.rt_next
= rt_hash_table
[hash
].chain
;
1175 * Since lookup is lockfree, we must make sure
1176 * previous writes to rt are committed to memory
1177 * before making rt visible to other CPUS.
1179 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rt
);
1181 spin_unlock_bh(rt_hash_lock_addr(hash
));
1185 skb_dst_set(skb
, &rt
->dst
);
1189 static atomic_t __rt_peer_genid
= ATOMIC_INIT(0);
1191 static u32
rt_peer_genid(void)
1193 return atomic_read(&__rt_peer_genid
);
1196 void rt_bind_peer(struct rtable
*rt
, int create
)
1198 struct inet_peer
*peer
;
1200 peer
= inet_getpeer_v4(rt
->rt_dst
, create
);
1202 if (peer
&& cmpxchg(&rt
->peer
, NULL
, peer
) != NULL
)
1205 rt
->rt_peer_genid
= rt_peer_genid();
1209 * Peer allocation may fail only in serious out-of-memory conditions. However
1210 * we still can generate some output.
1211 * Random ID selection looks a bit dangerous because we have no chances to
1212 * select ID being unique in a reasonable period of time.
1213 * But broken packet identifier may be better than no packet at all.
1215 static void ip_select_fb_ident(struct iphdr
*iph
)
1217 static DEFINE_SPINLOCK(ip_fb_id_lock
);
1218 static u32 ip_fallback_id
;
1221 spin_lock_bh(&ip_fb_id_lock
);
1222 salt
= secure_ip_id((__force __be32
)ip_fallback_id
^ iph
->daddr
);
1223 iph
->id
= htons(salt
& 0xFFFF);
1224 ip_fallback_id
= salt
;
1225 spin_unlock_bh(&ip_fb_id_lock
);
1228 void __ip_select_ident(struct iphdr
*iph
, struct dst_entry
*dst
, int more
)
1230 struct rtable
*rt
= (struct rtable
*) dst
;
1233 if (rt
->peer
== NULL
)
1234 rt_bind_peer(rt
, 1);
1236 /* If peer is attached to destination, it is never detached,
1237 so that we need not to grab a lock to dereference it.
1240 iph
->id
= htons(inet_getid(rt
->peer
, more
));
1244 printk(KERN_DEBUG
"rt_bind_peer(0) @%p\n",
1245 __builtin_return_address(0));
1247 ip_select_fb_ident(iph
);
1249 EXPORT_SYMBOL(__ip_select_ident
);
1251 static void rt_del(unsigned hash
, struct rtable
*rt
)
1253 struct rtable __rcu
**rthp
;
1256 rthp
= &rt_hash_table
[hash
].chain
;
1257 spin_lock_bh(rt_hash_lock_addr(hash
));
1259 while ((aux
= rcu_dereference_protected(*rthp
,
1260 lockdep_is_held(rt_hash_lock_addr(hash
)))) != NULL
) {
1261 if (aux
== rt
|| rt_is_expired(aux
)) {
1262 *rthp
= aux
->dst
.rt_next
;
1266 rthp
= &aux
->dst
.rt_next
;
1268 spin_unlock_bh(rt_hash_lock_addr(hash
));
1271 /* called in rcu_read_lock() section */
1272 void ip_rt_redirect(__be32 old_gw
, __be32 daddr
, __be32 new_gw
,
1273 __be32 saddr
, struct net_device
*dev
)
1275 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
1276 struct inet_peer
*peer
;
1283 if (new_gw
== old_gw
|| !IN_DEV_RX_REDIRECTS(in_dev
) ||
1284 ipv4_is_multicast(new_gw
) || ipv4_is_lbcast(new_gw
) ||
1285 ipv4_is_zeronet(new_gw
))
1286 goto reject_redirect
;
1288 if (!IN_DEV_SHARED_MEDIA(in_dev
)) {
1289 if (!inet_addr_onlink(in_dev
, new_gw
, old_gw
))
1290 goto reject_redirect
;
1291 if (IN_DEV_SEC_REDIRECTS(in_dev
) && ip_fib_check_default(new_gw
, dev
))
1292 goto reject_redirect
;
1294 if (inet_addr_type(net
, new_gw
) != RTN_UNICAST
)
1295 goto reject_redirect
;
1298 peer
= inet_getpeer_v4(daddr
, 1);
1300 peer
->redirect_learned
.a4
= new_gw
;
1304 atomic_inc(&__rt_peer_genid
);
1309 #ifdef CONFIG_IP_ROUTE_VERBOSE
1310 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit())
1311 printk(KERN_INFO
"Redirect from %pI4 on %s about %pI4 ignored.\n"
1312 " Advised path = %pI4 -> %pI4\n",
1313 &old_gw
, dev
->name
, &new_gw
,
1319 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
)
1321 struct rtable
*rt
= (struct rtable
*)dst
;
1322 struct dst_entry
*ret
= dst
;
1325 if (dst
->obsolete
> 0) {
1328 } else if (rt
->rt_flags
& RTCF_REDIRECTED
) {
1329 unsigned hash
= rt_hash(rt
->rt_key_dst
, rt
->rt_key_src
,
1331 rt_genid(dev_net(dst
->dev
)));
1334 } else if (rt
->peer
&&
1335 rt
->peer
->pmtu_expires
&&
1336 time_after_eq(jiffies
, rt
->peer
->pmtu_expires
)) {
1337 unsigned long orig
= rt
->peer
->pmtu_expires
;
1339 if (cmpxchg(&rt
->peer
->pmtu_expires
, orig
, 0) == orig
)
1340 dst_metric_set(dst
, RTAX_MTU
,
1341 rt
->peer
->pmtu_orig
);
1349 * 1. The first ip_rt_redirect_number redirects are sent
1350 * with exponential backoff, then we stop sending them at all,
1351 * assuming that the host ignores our redirects.
1352 * 2. If we did not see packets requiring redirects
1353 * during ip_rt_redirect_silence, we assume that the host
1354 * forgot redirected route and start to send redirects again.
1356 * This algorithm is much cheaper and more intelligent than dumb load limiting
1359 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1360 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1363 void ip_rt_send_redirect(struct sk_buff
*skb
)
1365 struct rtable
*rt
= skb_rtable(skb
);
1366 struct in_device
*in_dev
;
1367 struct inet_peer
*peer
;
1371 in_dev
= __in_dev_get_rcu(rt
->dst
.dev
);
1372 if (!in_dev
|| !IN_DEV_TX_REDIRECTS(in_dev
)) {
1376 log_martians
= IN_DEV_LOG_MARTIANS(in_dev
);
1380 rt_bind_peer(rt
, 1);
1383 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, rt
->rt_gateway
);
1387 /* No redirected packets during ip_rt_redirect_silence;
1388 * reset the algorithm.
1390 if (time_after(jiffies
, peer
->rate_last
+ ip_rt_redirect_silence
))
1391 peer
->rate_tokens
= 0;
1393 /* Too many ignored redirects; do not send anything
1394 * set dst.rate_last to the last seen redirected packet.
1396 if (peer
->rate_tokens
>= ip_rt_redirect_number
) {
1397 peer
->rate_last
= jiffies
;
1401 /* Check for load limit; set rate_last to the latest sent
1404 if (peer
->rate_tokens
== 0 ||
1407 (ip_rt_redirect_load
<< peer
->rate_tokens
)))) {
1408 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, rt
->rt_gateway
);
1409 peer
->rate_last
= jiffies
;
1410 ++peer
->rate_tokens
;
1411 #ifdef CONFIG_IP_ROUTE_VERBOSE
1413 peer
->rate_tokens
== ip_rt_redirect_number
&&
1415 printk(KERN_WARNING
"host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1416 &ip_hdr(skb
)->saddr
, rt
->rt_iif
,
1417 &rt
->rt_dst
, &rt
->rt_gateway
);
1422 static int ip_error(struct sk_buff
*skb
)
1424 struct rtable
*rt
= skb_rtable(skb
);
1425 struct inet_peer
*peer
;
1430 switch (rt
->dst
.error
) {
1435 code
= ICMP_HOST_UNREACH
;
1438 code
= ICMP_NET_UNREACH
;
1439 IP_INC_STATS_BH(dev_net(rt
->dst
.dev
),
1440 IPSTATS_MIB_INNOROUTES
);
1443 code
= ICMP_PKT_FILTERED
;
1448 rt_bind_peer(rt
, 1);
1454 peer
->rate_tokens
+= now
- peer
->rate_last
;
1455 if (peer
->rate_tokens
> ip_rt_error_burst
)
1456 peer
->rate_tokens
= ip_rt_error_burst
;
1457 peer
->rate_last
= now
;
1458 if (peer
->rate_tokens
>= ip_rt_error_cost
)
1459 peer
->rate_tokens
-= ip_rt_error_cost
;
1464 icmp_send(skb
, ICMP_DEST_UNREACH
, code
, 0);
1466 out
: kfree_skb(skb
);
1471 * The last two values are not from the RFC but
1472 * are needed for AMPRnet AX.25 paths.
1475 static const unsigned short mtu_plateau
[] =
1476 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1478 static inline unsigned short guess_mtu(unsigned short old_mtu
)
1482 for (i
= 0; i
< ARRAY_SIZE(mtu_plateau
); i
++)
1483 if (old_mtu
> mtu_plateau
[i
])
1484 return mtu_plateau
[i
];
1488 unsigned short ip_rt_frag_needed(struct net
*net
, const struct iphdr
*iph
,
1489 unsigned short new_mtu
,
1490 struct net_device
*dev
)
1492 unsigned short old_mtu
= ntohs(iph
->tot_len
);
1493 unsigned short est_mtu
= 0;
1494 struct inet_peer
*peer
;
1496 peer
= inet_getpeer_v4(iph
->daddr
, 1);
1498 unsigned short mtu
= new_mtu
;
1500 if (new_mtu
< 68 || new_mtu
>= old_mtu
) {
1501 /* BSD 4.2 derived systems incorrectly adjust
1502 * tot_len by the IP header length, and report
1503 * a zero MTU in the ICMP message.
1506 old_mtu
>= 68 + (iph
->ihl
<< 2))
1507 old_mtu
-= iph
->ihl
<< 2;
1508 mtu
= guess_mtu(old_mtu
);
1511 if (mtu
< ip_rt_min_pmtu
)
1512 mtu
= ip_rt_min_pmtu
;
1513 if (!peer
->pmtu_expires
|| mtu
< peer
->pmtu_learned
) {
1514 unsigned long pmtu_expires
;
1516 pmtu_expires
= jiffies
+ ip_rt_mtu_expires
;
1521 peer
->pmtu_learned
= mtu
;
1522 peer
->pmtu_expires
= pmtu_expires
;
1527 atomic_inc(&__rt_peer_genid
);
1529 return est_mtu
? : new_mtu
;
1532 static void check_peer_pmtu(struct dst_entry
*dst
, struct inet_peer
*peer
)
1534 unsigned long expires
= peer
->pmtu_expires
;
1536 if (time_before(jiffies
, expires
)) {
1537 u32 orig_dst_mtu
= dst_mtu(dst
);
1538 if (peer
->pmtu_learned
< orig_dst_mtu
) {
1539 if (!peer
->pmtu_orig
)
1540 peer
->pmtu_orig
= dst_metric_raw(dst
, RTAX_MTU
);
1541 dst_metric_set(dst
, RTAX_MTU
, peer
->pmtu_learned
);
1543 } else if (cmpxchg(&peer
->pmtu_expires
, expires
, 0) == expires
)
1544 dst_metric_set(dst
, RTAX_MTU
, peer
->pmtu_orig
);
1547 static void ip_rt_update_pmtu(struct dst_entry
*dst
, u32 mtu
)
1549 struct rtable
*rt
= (struct rtable
*) dst
;
1550 struct inet_peer
*peer
;
1555 rt_bind_peer(rt
, 1);
1558 if (mtu
< ip_rt_min_pmtu
)
1559 mtu
= ip_rt_min_pmtu
;
1560 if (!peer
->pmtu_expires
|| mtu
< peer
->pmtu_learned
) {
1561 unsigned long pmtu_expires
;
1563 pmtu_expires
= jiffies
+ ip_rt_mtu_expires
;
1567 peer
->pmtu_learned
= mtu
;
1568 peer
->pmtu_expires
= pmtu_expires
;
1570 atomic_inc(&__rt_peer_genid
);
1571 rt
->rt_peer_genid
= rt_peer_genid();
1573 check_peer_pmtu(dst
, peer
);
1577 static int check_peer_redir(struct dst_entry
*dst
, struct inet_peer
*peer
)
1579 struct rtable
*rt
= (struct rtable
*) dst
;
1580 __be32 orig_gw
= rt
->rt_gateway
;
1582 dst_confirm(&rt
->dst
);
1584 neigh_release(rt
->dst
.neighbour
);
1585 rt
->dst
.neighbour
= NULL
;
1587 rt
->rt_gateway
= peer
->redirect_learned
.a4
;
1588 if (arp_bind_neighbour(&rt
->dst
) ||
1589 !(rt
->dst
.neighbour
->nud_state
& NUD_VALID
)) {
1590 if (rt
->dst
.neighbour
)
1591 neigh_event_send(rt
->dst
.neighbour
, NULL
);
1592 rt
->rt_gateway
= orig_gw
;
1595 rt
->rt_flags
|= RTCF_REDIRECTED
;
1596 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE
,
1602 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
)
1604 struct rtable
*rt
= (struct rtable
*) dst
;
1606 if (rt_is_expired(rt
))
1608 if (rt
->rt_peer_genid
!= rt_peer_genid()) {
1609 struct inet_peer
*peer
;
1612 rt_bind_peer(rt
, 0);
1615 if (peer
&& peer
->pmtu_expires
)
1616 check_peer_pmtu(dst
, peer
);
1618 if (peer
&& peer
->redirect_learned
.a4
&&
1619 peer
->redirect_learned
.a4
!= rt
->rt_gateway
) {
1620 if (check_peer_redir(dst
, peer
))
1624 rt
->rt_peer_genid
= rt_peer_genid();
1629 static void ipv4_dst_destroy(struct dst_entry
*dst
)
1631 struct rtable
*rt
= (struct rtable
*) dst
;
1632 struct inet_peer
*peer
= rt
->peer
;
1635 fib_info_put(rt
->fi
);
1645 static void ipv4_link_failure(struct sk_buff
*skb
)
1649 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_HOST_UNREACH
, 0);
1651 rt
= skb_rtable(skb
);
1654 rt
->peer
->pmtu_expires
) {
1655 unsigned long orig
= rt
->peer
->pmtu_expires
;
1657 if (cmpxchg(&rt
->peer
->pmtu_expires
, orig
, 0) == orig
)
1658 dst_metric_set(&rt
->dst
, RTAX_MTU
, rt
->peer
->pmtu_orig
);
1662 static int ip_rt_bug(struct sk_buff
*skb
)
1664 printk(KERN_DEBUG
"ip_rt_bug: %pI4 -> %pI4, %s\n",
1665 &ip_hdr(skb
)->saddr
, &ip_hdr(skb
)->daddr
,
1666 skb
->dev
? skb
->dev
->name
: "?");
1672 We do not cache source address of outgoing interface,
1673 because it is used only by IP RR, TS and SRR options,
1674 so that it out of fast path.
1676 BTW remember: "addr" is allowed to be not aligned
1680 void ip_rt_get_source(u8
*addr
, struct sk_buff
*skb
, struct rtable
*rt
)
1684 if (rt_is_output_route(rt
))
1685 src
= ip_hdr(skb
)->saddr
;
1687 struct fib_result res
;
1693 memset(&fl4
, 0, sizeof(fl4
));
1694 fl4
.daddr
= iph
->daddr
;
1695 fl4
.saddr
= iph
->saddr
;
1696 fl4
.flowi4_tos
= iph
->tos
;
1697 fl4
.flowi4_oif
= rt
->dst
.dev
->ifindex
;
1698 fl4
.flowi4_iif
= skb
->dev
->ifindex
;
1699 fl4
.flowi4_mark
= skb
->mark
;
1702 if (fib_lookup(dev_net(rt
->dst
.dev
), &fl4
, &res
) == 0)
1703 src
= FIB_RES_PREFSRC(dev_net(rt
->dst
.dev
), res
);
1705 src
= inet_select_addr(rt
->dst
.dev
, rt
->rt_gateway
,
1709 memcpy(addr
, &src
, 4);
1712 #ifdef CONFIG_IP_ROUTE_CLASSID
1713 static void set_class_tag(struct rtable
*rt
, u32 tag
)
1715 if (!(rt
->dst
.tclassid
& 0xFFFF))
1716 rt
->dst
.tclassid
|= tag
& 0xFFFF;
1717 if (!(rt
->dst
.tclassid
& 0xFFFF0000))
1718 rt
->dst
.tclassid
|= tag
& 0xFFFF0000;
1722 static unsigned int ipv4_default_advmss(const struct dst_entry
*dst
)
1724 unsigned int advmss
= dst_metric_raw(dst
, RTAX_ADVMSS
);
1727 advmss
= max_t(unsigned int, dst
->dev
->mtu
- 40,
1729 if (advmss
> 65535 - 40)
1730 advmss
= 65535 - 40;
1735 static unsigned int ipv4_default_mtu(const struct dst_entry
*dst
)
1737 unsigned int mtu
= dst
->dev
->mtu
;
1739 if (unlikely(dst_metric_locked(dst
, RTAX_MTU
))) {
1740 const struct rtable
*rt
= (const struct rtable
*) dst
;
1742 if (rt
->rt_gateway
!= rt
->rt_dst
&& mtu
> 576)
1746 if (mtu
> IP_MAX_MTU
)
1752 static void rt_init_metrics(struct rtable
*rt
, const struct flowi4
*fl4
,
1753 struct fib_info
*fi
)
1755 struct inet_peer
*peer
;
1758 /* If a peer entry exists for this destination, we must hook
1759 * it up in order to get at cached metrics.
1761 if (fl4
&& (fl4
->flowi4_flags
& FLOWI_FLAG_PRECOW_METRICS
))
1764 rt
->peer
= peer
= inet_getpeer_v4(rt
->rt_dst
, create
);
1766 rt
->rt_peer_genid
= rt_peer_genid();
1767 if (inet_metrics_new(peer
))
1768 memcpy(peer
->metrics
, fi
->fib_metrics
,
1769 sizeof(u32
) * RTAX_MAX
);
1770 dst_init_metrics(&rt
->dst
, peer
->metrics
, false);
1772 if (peer
->pmtu_expires
)
1773 check_peer_pmtu(&rt
->dst
, peer
);
1774 if (peer
->redirect_learned
.a4
&&
1775 peer
->redirect_learned
.a4
!= rt
->rt_gateway
) {
1776 rt
->rt_gateway
= peer
->redirect_learned
.a4
;
1777 rt
->rt_flags
|= RTCF_REDIRECTED
;
1780 if (fi
->fib_metrics
!= (u32
*) dst_default_metrics
) {
1782 atomic_inc(&fi
->fib_clntref
);
1784 dst_init_metrics(&rt
->dst
, fi
->fib_metrics
, true);
1788 static void rt_set_nexthop(struct rtable
*rt
, const struct flowi4
*fl4
,
1789 const struct fib_result
*res
,
1790 struct fib_info
*fi
, u16 type
, u32 itag
)
1792 struct dst_entry
*dst
= &rt
->dst
;
1795 if (FIB_RES_GW(*res
) &&
1796 FIB_RES_NH(*res
).nh_scope
== RT_SCOPE_LINK
)
1797 rt
->rt_gateway
= FIB_RES_GW(*res
);
1798 rt_init_metrics(rt
, fl4
, fi
);
1799 #ifdef CONFIG_IP_ROUTE_CLASSID
1800 dst
->tclassid
= FIB_RES_NH(*res
).nh_tclassid
;
1804 if (dst_mtu(dst
) > IP_MAX_MTU
)
1805 dst_metric_set(dst
, RTAX_MTU
, IP_MAX_MTU
);
1806 if (dst_metric_raw(dst
, RTAX_ADVMSS
) > 65535 - 40)
1807 dst_metric_set(dst
, RTAX_ADVMSS
, 65535 - 40);
1809 #ifdef CONFIG_IP_ROUTE_CLASSID
1810 #ifdef CONFIG_IP_MULTIPLE_TABLES
1811 set_class_tag(rt
, fib_rules_tclass(res
));
1813 set_class_tag(rt
, itag
);
1817 static struct rtable
*rt_dst_alloc(struct net_device
*dev
,
1818 bool nopolicy
, bool noxfrm
)
1820 return dst_alloc(&ipv4_dst_ops
, dev
, 1, -1,
1822 (nopolicy
? DST_NOPOLICY
: 0) |
1823 (noxfrm
? DST_NOXFRM
: 0));
1826 /* called in rcu_read_lock() section */
1827 static int ip_route_input_mc(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
1828 u8 tos
, struct net_device
*dev
, int our
)
1833 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
1837 /* Primary sanity checks. */
1842 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
) ||
1843 ipv4_is_loopback(saddr
) || skb
->protocol
!= htons(ETH_P_IP
))
1846 if (ipv4_is_zeronet(saddr
)) {
1847 if (!ipv4_is_local_multicast(daddr
))
1849 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_LINK
);
1851 err
= fib_validate_source(skb
, saddr
, 0, tos
, 0, dev
, &spec_dst
,
1856 rth
= rt_dst_alloc(init_net
.loopback_dev
,
1857 IN_DEV_CONF_GET(in_dev
, NOPOLICY
), false);
1861 #ifdef CONFIG_IP_ROUTE_CLASSID
1862 rth
->dst
.tclassid
= itag
;
1864 rth
->dst
.output
= ip_rt_bug
;
1866 rth
->rt_key_dst
= daddr
;
1867 rth
->rt_key_src
= saddr
;
1868 rth
->rt_genid
= rt_genid(dev_net(dev
));
1869 rth
->rt_flags
= RTCF_MULTICAST
;
1870 rth
->rt_type
= RTN_MULTICAST
;
1871 rth
->rt_key_tos
= tos
;
1872 rth
->rt_dst
= daddr
;
1873 rth
->rt_src
= saddr
;
1874 rth
->rt_route_iif
= dev
->ifindex
;
1875 rth
->rt_iif
= dev
->ifindex
;
1877 rth
->rt_mark
= skb
->mark
;
1878 rth
->rt_gateway
= daddr
;
1879 rth
->rt_spec_dst
= spec_dst
;
1880 rth
->rt_peer_genid
= 0;
1884 rth
->dst
.input
= ip_local_deliver
;
1885 rth
->rt_flags
|= RTCF_LOCAL
;
1888 #ifdef CONFIG_IP_MROUTE
1889 if (!ipv4_is_local_multicast(daddr
) && IN_DEV_MFORWARD(in_dev
))
1890 rth
->dst
.input
= ip_mr_input
;
1892 RT_CACHE_STAT_INC(in_slow_mc
);
1894 hash
= rt_hash(daddr
, saddr
, dev
->ifindex
, rt_genid(dev_net(dev
)));
1895 rth
= rt_intern_hash(hash
, rth
, skb
, dev
->ifindex
);
1909 static void ip_handle_martian_source(struct net_device
*dev
,
1910 struct in_device
*in_dev
,
1911 struct sk_buff
*skb
,
1915 RT_CACHE_STAT_INC(in_martian_src
);
1916 #ifdef CONFIG_IP_ROUTE_VERBOSE
1917 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit()) {
1919 * RFC1812 recommendation, if source is martian,
1920 * the only hint is MAC header.
1922 printk(KERN_WARNING
"martian source %pI4 from %pI4, on dev %s\n",
1923 &daddr
, &saddr
, dev
->name
);
1924 if (dev
->hard_header_len
&& skb_mac_header_was_set(skb
)) {
1926 const unsigned char *p
= skb_mac_header(skb
);
1927 printk(KERN_WARNING
"ll header: ");
1928 for (i
= 0; i
< dev
->hard_header_len
; i
++, p
++) {
1930 if (i
< (dev
->hard_header_len
- 1))
1939 /* called in rcu_read_lock() section */
1940 static int __mkroute_input(struct sk_buff
*skb
,
1941 const struct fib_result
*res
,
1942 struct in_device
*in_dev
,
1943 __be32 daddr
, __be32 saddr
, u32 tos
,
1944 struct rtable
**result
)
1948 struct in_device
*out_dev
;
1949 unsigned int flags
= 0;
1953 /* get a working reference to the output device */
1954 out_dev
= __in_dev_get_rcu(FIB_RES_DEV(*res
));
1955 if (out_dev
== NULL
) {
1956 if (net_ratelimit())
1957 printk(KERN_CRIT
"Bug in ip_route_input" \
1958 "_slow(). Please, report\n");
1963 err
= fib_validate_source(skb
, saddr
, daddr
, tos
, FIB_RES_OIF(*res
),
1964 in_dev
->dev
, &spec_dst
, &itag
);
1966 ip_handle_martian_source(in_dev
->dev
, in_dev
, skb
, daddr
,
1973 flags
|= RTCF_DIRECTSRC
;
1975 if (out_dev
== in_dev
&& err
&&
1976 (IN_DEV_SHARED_MEDIA(out_dev
) ||
1977 inet_addr_onlink(out_dev
, saddr
, FIB_RES_GW(*res
))))
1978 flags
|= RTCF_DOREDIRECT
;
1980 if (skb
->protocol
!= htons(ETH_P_IP
)) {
1981 /* Not IP (i.e. ARP). Do not create route, if it is
1982 * invalid for proxy arp. DNAT routes are always valid.
1984 * Proxy arp feature have been extended to allow, ARP
1985 * replies back to the same interface, to support
1986 * Private VLAN switch technologies. See arp.c.
1988 if (out_dev
== in_dev
&&
1989 IN_DEV_PROXY_ARP_PVLAN(in_dev
) == 0) {
1995 rth
= rt_dst_alloc(out_dev
->dev
,
1996 IN_DEV_CONF_GET(in_dev
, NOPOLICY
),
1997 IN_DEV_CONF_GET(out_dev
, NOXFRM
));
2003 rth
->rt_key_dst
= daddr
;
2004 rth
->rt_key_src
= saddr
;
2005 rth
->rt_genid
= rt_genid(dev_net(rth
->dst
.dev
));
2006 rth
->rt_flags
= flags
;
2007 rth
->rt_type
= res
->type
;
2008 rth
->rt_key_tos
= tos
;
2009 rth
->rt_dst
= daddr
;
2010 rth
->rt_src
= saddr
;
2011 rth
->rt_route_iif
= in_dev
->dev
->ifindex
;
2012 rth
->rt_iif
= in_dev
->dev
->ifindex
;
2014 rth
->rt_mark
= skb
->mark
;
2015 rth
->rt_gateway
= daddr
;
2016 rth
->rt_spec_dst
= spec_dst
;
2017 rth
->rt_peer_genid
= 0;
2021 rth
->dst
.input
= ip_forward
;
2022 rth
->dst
.output
= ip_output
;
2024 rt_set_nexthop(rth
, NULL
, res
, res
->fi
, res
->type
, itag
);
2032 static int ip_mkroute_input(struct sk_buff
*skb
,
2033 struct fib_result
*res
,
2034 const struct flowi4
*fl4
,
2035 struct in_device
*in_dev
,
2036 __be32 daddr
, __be32 saddr
, u32 tos
)
2038 struct rtable
* rth
= NULL
;
2042 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2043 if (res
->fi
&& res
->fi
->fib_nhs
> 1)
2044 fib_select_multipath(res
);
2047 /* create a routing cache entry */
2048 err
= __mkroute_input(skb
, res
, in_dev
, daddr
, saddr
, tos
, &rth
);
2052 /* put it into the cache */
2053 hash
= rt_hash(daddr
, saddr
, fl4
->flowi4_iif
,
2054 rt_genid(dev_net(rth
->dst
.dev
)));
2055 rth
= rt_intern_hash(hash
, rth
, skb
, fl4
->flowi4_iif
);
2057 return PTR_ERR(rth
);
2062 * NOTE. We drop all the packets that has local source
2063 * addresses, because every properly looped back packet
2064 * must have correct destination already attached by output routine.
2066 * Such approach solves two big problems:
2067 * 1. Not simplex devices are handled properly.
2068 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2069 * called with rcu_read_lock()
2072 static int ip_route_input_slow(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2073 u8 tos
, struct net_device
*dev
)
2075 struct fib_result res
;
2076 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
2080 struct rtable
* rth
;
2084 struct net
* net
= dev_net(dev
);
2086 /* IP on this device is disabled. */
2091 /* Check for the most weird martians, which can be not detected
2095 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
) ||
2096 ipv4_is_loopback(saddr
))
2097 goto martian_source
;
2099 if (ipv4_is_lbcast(daddr
) || (saddr
== 0 && daddr
== 0))
2102 /* Accept zero addresses only to limited broadcast;
2103 * I even do not know to fix it or not. Waiting for complains :-)
2105 if (ipv4_is_zeronet(saddr
))
2106 goto martian_source
;
2108 if (ipv4_is_zeronet(daddr
) || ipv4_is_loopback(daddr
))
2109 goto martian_destination
;
2112 * Now we are ready to route packet.
2115 fl4
.flowi4_iif
= dev
->ifindex
;
2116 fl4
.flowi4_mark
= skb
->mark
;
2117 fl4
.flowi4_tos
= tos
;
2118 fl4
.flowi4_scope
= RT_SCOPE_UNIVERSE
;
2121 err
= fib_lookup(net
, &fl4
, &res
);
2123 if (!IN_DEV_FORWARD(in_dev
))
2128 RT_CACHE_STAT_INC(in_slow_tot
);
2130 if (res
.type
== RTN_BROADCAST
)
2133 if (res
.type
== RTN_LOCAL
) {
2134 err
= fib_validate_source(skb
, saddr
, daddr
, tos
,
2135 net
->loopback_dev
->ifindex
,
2136 dev
, &spec_dst
, &itag
);
2138 goto martian_source_keep_err
;
2140 flags
|= RTCF_DIRECTSRC
;
2145 if (!IN_DEV_FORWARD(in_dev
))
2147 if (res
.type
!= RTN_UNICAST
)
2148 goto martian_destination
;
2150 err
= ip_mkroute_input(skb
, &res
, &fl4
, in_dev
, daddr
, saddr
, tos
);
2154 if (skb
->protocol
!= htons(ETH_P_IP
))
2157 if (ipv4_is_zeronet(saddr
))
2158 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_LINK
);
2160 err
= fib_validate_source(skb
, saddr
, 0, tos
, 0, dev
, &spec_dst
,
2163 goto martian_source_keep_err
;
2165 flags
|= RTCF_DIRECTSRC
;
2167 flags
|= RTCF_BROADCAST
;
2168 res
.type
= RTN_BROADCAST
;
2169 RT_CACHE_STAT_INC(in_brd
);
2172 rth
= rt_dst_alloc(net
->loopback_dev
,
2173 IN_DEV_CONF_GET(in_dev
, NOPOLICY
), false);
2177 rth
->dst
.input
= ip_local_deliver
;
2178 rth
->dst
.output
= ip_rt_bug
;
2179 #ifdef CONFIG_IP_ROUTE_CLASSID
2180 rth
->dst
.tclassid
= itag
;
2183 rth
->rt_key_dst
= daddr
;
2184 rth
->rt_key_src
= saddr
;
2185 rth
->rt_genid
= rt_genid(net
);
2186 rth
->rt_flags
= flags
|RTCF_LOCAL
;
2187 rth
->rt_type
= res
.type
;
2188 rth
->rt_key_tos
= tos
;
2189 rth
->rt_dst
= daddr
;
2190 rth
->rt_src
= saddr
;
2191 #ifdef CONFIG_IP_ROUTE_CLASSID
2192 rth
->dst
.tclassid
= itag
;
2194 rth
->rt_route_iif
= dev
->ifindex
;
2195 rth
->rt_iif
= dev
->ifindex
;
2197 rth
->rt_mark
= skb
->mark
;
2198 rth
->rt_gateway
= daddr
;
2199 rth
->rt_spec_dst
= spec_dst
;
2200 rth
->rt_peer_genid
= 0;
2203 if (res
.type
== RTN_UNREACHABLE
) {
2204 rth
->dst
.input
= ip_error
;
2205 rth
->dst
.error
= -err
;
2206 rth
->rt_flags
&= ~RTCF_LOCAL
;
2208 hash
= rt_hash(daddr
, saddr
, fl4
.flowi4_iif
, rt_genid(net
));
2209 rth
= rt_intern_hash(hash
, rth
, skb
, fl4
.flowi4_iif
);
2216 RT_CACHE_STAT_INC(in_no_route
);
2217 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_UNIVERSE
);
2218 res
.type
= RTN_UNREACHABLE
;
2224 * Do not cache martian addresses: they should be logged (RFC1812)
2226 martian_destination
:
2227 RT_CACHE_STAT_INC(in_martian_dst
);
2228 #ifdef CONFIG_IP_ROUTE_VERBOSE
2229 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit())
2230 printk(KERN_WARNING
"martian destination %pI4 from %pI4, dev %s\n",
2231 &daddr
, &saddr
, dev
->name
);
2235 err
= -EHOSTUNREACH
;
2248 martian_source_keep_err
:
2249 ip_handle_martian_source(dev
, in_dev
, skb
, daddr
, saddr
);
2253 int ip_route_input_common(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2254 u8 tos
, struct net_device
*dev
, bool noref
)
2256 struct rtable
* rth
;
2258 int iif
= dev
->ifindex
;
2266 if (!rt_caching(net
))
2269 tos
&= IPTOS_RT_MASK
;
2270 hash
= rt_hash(daddr
, saddr
, iif
, rt_genid(net
));
2272 for (rth
= rcu_dereference(rt_hash_table
[hash
].chain
); rth
;
2273 rth
= rcu_dereference(rth
->dst
.rt_next
)) {
2274 if ((((__force u32
)rth
->rt_key_dst
^ (__force u32
)daddr
) |
2275 ((__force u32
)rth
->rt_key_src
^ (__force u32
)saddr
) |
2276 (rth
->rt_iif
^ iif
) |
2278 (rth
->rt_key_tos
^ tos
)) == 0 &&
2279 rth
->rt_mark
== skb
->mark
&&
2280 net_eq(dev_net(rth
->dst
.dev
), net
) &&
2281 !rt_is_expired(rth
)) {
2283 dst_use_noref(&rth
->dst
, jiffies
);
2284 skb_dst_set_noref(skb
, &rth
->dst
);
2286 dst_use(&rth
->dst
, jiffies
);
2287 skb_dst_set(skb
, &rth
->dst
);
2289 RT_CACHE_STAT_INC(in_hit
);
2293 RT_CACHE_STAT_INC(in_hlist_search
);
2297 /* Multicast recognition logic is moved from route cache to here.
2298 The problem was that too many Ethernet cards have broken/missing
2299 hardware multicast filters :-( As result the host on multicasting
2300 network acquires a lot of useless route cache entries, sort of
2301 SDR messages from all the world. Now we try to get rid of them.
2302 Really, provided software IP multicast filter is organized
2303 reasonably (at least, hashed), it does not result in a slowdown
2304 comparing with route cache reject entries.
2305 Note, that multicast routers are not affected, because
2306 route cache entry is created eventually.
2308 if (ipv4_is_multicast(daddr
)) {
2309 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
2312 int our
= ip_check_mc_rcu(in_dev
, daddr
, saddr
,
2313 ip_hdr(skb
)->protocol
);
2315 #ifdef CONFIG_IP_MROUTE
2317 (!ipv4_is_local_multicast(daddr
) &&
2318 IN_DEV_MFORWARD(in_dev
))
2321 int res
= ip_route_input_mc(skb
, daddr
, saddr
,
2330 res
= ip_route_input_slow(skb
, daddr
, saddr
, tos
, dev
);
2334 EXPORT_SYMBOL(ip_route_input_common
);
2336 /* called with rcu_read_lock() */
2337 static struct rtable
*__mkroute_output(const struct fib_result
*res
,
2338 const struct flowi4
*fl4
,
2339 __be32 orig_daddr
, __be32 orig_saddr
,
2340 int orig_oif
, struct net_device
*dev_out
,
2343 struct fib_info
*fi
= res
->fi
;
2344 u32 tos
= RT_FL_TOS(fl4
);
2345 struct in_device
*in_dev
;
2346 u16 type
= res
->type
;
2349 if (ipv4_is_loopback(fl4
->saddr
) && !(dev_out
->flags
& IFF_LOOPBACK
))
2350 return ERR_PTR(-EINVAL
);
2352 if (ipv4_is_lbcast(fl4
->daddr
))
2353 type
= RTN_BROADCAST
;
2354 else if (ipv4_is_multicast(fl4
->daddr
))
2355 type
= RTN_MULTICAST
;
2356 else if (ipv4_is_zeronet(fl4
->daddr
))
2357 return ERR_PTR(-EINVAL
);
2359 if (dev_out
->flags
& IFF_LOOPBACK
)
2360 flags
|= RTCF_LOCAL
;
2362 in_dev
= __in_dev_get_rcu(dev_out
);
2364 return ERR_PTR(-EINVAL
);
2366 if (type
== RTN_BROADCAST
) {
2367 flags
|= RTCF_BROADCAST
| RTCF_LOCAL
;
2369 } else if (type
== RTN_MULTICAST
) {
2370 flags
|= RTCF_MULTICAST
| RTCF_LOCAL
;
2371 if (!ip_check_mc_rcu(in_dev
, fl4
->daddr
, fl4
->saddr
,
2373 flags
&= ~RTCF_LOCAL
;
2374 /* If multicast route do not exist use
2375 * default one, but do not gateway in this case.
2378 if (fi
&& res
->prefixlen
< 4)
2382 rth
= rt_dst_alloc(dev_out
,
2383 IN_DEV_CONF_GET(in_dev
, NOPOLICY
),
2384 IN_DEV_CONF_GET(in_dev
, NOXFRM
));
2386 return ERR_PTR(-ENOBUFS
);
2388 rth
->dst
.output
= ip_output
;
2390 rth
->rt_key_dst
= orig_daddr
;
2391 rth
->rt_key_src
= orig_saddr
;
2392 rth
->rt_genid
= rt_genid(dev_net(dev_out
));
2393 rth
->rt_flags
= flags
;
2394 rth
->rt_type
= type
;
2395 rth
->rt_key_tos
= tos
;
2396 rth
->rt_dst
= fl4
->daddr
;
2397 rth
->rt_src
= fl4
->saddr
;
2398 rth
->rt_route_iif
= 0;
2399 rth
->rt_iif
= orig_oif
? : dev_out
->ifindex
;
2400 rth
->rt_oif
= orig_oif
;
2401 rth
->rt_mark
= fl4
->flowi4_mark
;
2402 rth
->rt_gateway
= fl4
->daddr
;
2403 rth
->rt_spec_dst
= fl4
->saddr
;
2404 rth
->rt_peer_genid
= 0;
2408 RT_CACHE_STAT_INC(out_slow_tot
);
2410 if (flags
& RTCF_LOCAL
) {
2411 rth
->dst
.input
= ip_local_deliver
;
2412 rth
->rt_spec_dst
= fl4
->daddr
;
2414 if (flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) {
2415 rth
->rt_spec_dst
= fl4
->saddr
;
2416 if (flags
& RTCF_LOCAL
&&
2417 !(dev_out
->flags
& IFF_LOOPBACK
)) {
2418 rth
->dst
.output
= ip_mc_output
;
2419 RT_CACHE_STAT_INC(out_slow_mc
);
2421 #ifdef CONFIG_IP_MROUTE
2422 if (type
== RTN_MULTICAST
) {
2423 if (IN_DEV_MFORWARD(in_dev
) &&
2424 !ipv4_is_local_multicast(fl4
->daddr
)) {
2425 rth
->dst
.input
= ip_mr_input
;
2426 rth
->dst
.output
= ip_mc_output
;
2432 rt_set_nexthop(rth
, fl4
, res
, fi
, type
, 0);
2438 * Major route resolver routine.
2439 * called with rcu_read_lock();
2442 static struct rtable
*ip_route_output_slow(struct net
*net
, struct flowi4
*fl4
)
2444 struct net_device
*dev_out
= NULL
;
2445 u32 tos
= RT_FL_TOS(fl4
);
2446 unsigned int flags
= 0;
2447 struct fib_result res
;
2454 #ifdef CONFIG_IP_MULTIPLE_TABLES
2458 orig_daddr
= fl4
->daddr
;
2459 orig_saddr
= fl4
->saddr
;
2460 orig_oif
= fl4
->flowi4_oif
;
2462 fl4
->flowi4_iif
= net
->loopback_dev
->ifindex
;
2463 fl4
->flowi4_tos
= tos
& IPTOS_RT_MASK
;
2464 fl4
->flowi4_scope
= ((tos
& RTO_ONLINK
) ?
2465 RT_SCOPE_LINK
: RT_SCOPE_UNIVERSE
);
2469 rth
= ERR_PTR(-EINVAL
);
2470 if (ipv4_is_multicast(fl4
->saddr
) ||
2471 ipv4_is_lbcast(fl4
->saddr
) ||
2472 ipv4_is_zeronet(fl4
->saddr
))
2475 /* I removed check for oif == dev_out->oif here.
2476 It was wrong for two reasons:
2477 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2478 is assigned to multiple interfaces.
2479 2. Moreover, we are allowed to send packets with saddr
2480 of another iface. --ANK
2483 if (fl4
->flowi4_oif
== 0 &&
2484 (ipv4_is_multicast(fl4
->daddr
) ||
2485 ipv4_is_lbcast(fl4
->daddr
))) {
2486 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2487 dev_out
= __ip_dev_find(net
, fl4
->saddr
, false);
2488 if (dev_out
== NULL
)
2491 /* Special hack: user can direct multicasts
2492 and limited broadcast via necessary interface
2493 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2494 This hack is not just for fun, it allows
2495 vic,vat and friends to work.
2496 They bind socket to loopback, set ttl to zero
2497 and expect that it will work.
2498 From the viewpoint of routing cache they are broken,
2499 because we are not allowed to build multicast path
2500 with loopback source addr (look, routing cache
2501 cannot know, that ttl is zero, so that packet
2502 will not leave this host and route is valid).
2503 Luckily, this hack is good workaround.
2506 fl4
->flowi4_oif
= dev_out
->ifindex
;
2510 if (!(fl4
->flowi4_flags
& FLOWI_FLAG_ANYSRC
)) {
2511 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2512 if (!__ip_dev_find(net
, fl4
->saddr
, false))
2518 if (fl4
->flowi4_oif
) {
2519 dev_out
= dev_get_by_index_rcu(net
, fl4
->flowi4_oif
);
2520 rth
= ERR_PTR(-ENODEV
);
2521 if (dev_out
== NULL
)
2524 /* RACE: Check return value of inet_select_addr instead. */
2525 if (!(dev_out
->flags
& IFF_UP
) || !__in_dev_get_rcu(dev_out
)) {
2526 rth
= ERR_PTR(-ENETUNREACH
);
2529 if (ipv4_is_local_multicast(fl4
->daddr
) ||
2530 ipv4_is_lbcast(fl4
->daddr
)) {
2532 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2537 if (ipv4_is_multicast(fl4
->daddr
))
2538 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2540 else if (!fl4
->daddr
)
2541 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2547 fl4
->daddr
= fl4
->saddr
;
2549 fl4
->daddr
= fl4
->saddr
= htonl(INADDR_LOOPBACK
);
2550 dev_out
= net
->loopback_dev
;
2551 fl4
->flowi4_oif
= net
->loopback_dev
->ifindex
;
2552 res
.type
= RTN_LOCAL
;
2553 flags
|= RTCF_LOCAL
;
2557 if (fib_lookup(net
, fl4
, &res
)) {
2559 if (fl4
->flowi4_oif
) {
2560 /* Apparently, routing tables are wrong. Assume,
2561 that the destination is on link.
2564 Because we are allowed to send to iface
2565 even if it has NO routes and NO assigned
2566 addresses. When oif is specified, routing
2567 tables are looked up with only one purpose:
2568 to catch if destination is gatewayed, rather than
2569 direct. Moreover, if MSG_DONTROUTE is set,
2570 we send packet, ignoring both routing tables
2571 and ifaddr state. --ANK
2574 We could make it even if oif is unknown,
2575 likely IPv6, but we do not.
2578 if (fl4
->saddr
== 0)
2579 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2581 res
.type
= RTN_UNICAST
;
2584 rth
= ERR_PTR(-ENETUNREACH
);
2588 if (res
.type
== RTN_LOCAL
) {
2590 if (res
.fi
->fib_prefsrc
)
2591 fl4
->saddr
= res
.fi
->fib_prefsrc
;
2593 fl4
->saddr
= fl4
->daddr
;
2595 dev_out
= net
->loopback_dev
;
2596 fl4
->flowi4_oif
= dev_out
->ifindex
;
2598 flags
|= RTCF_LOCAL
;
2602 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2603 if (res
.fi
->fib_nhs
> 1 && fl4
->flowi4_oif
== 0)
2604 fib_select_multipath(&res
);
2607 if (!res
.prefixlen
&&
2608 res
.table
->tb_num_default
> 1 &&
2609 res
.type
== RTN_UNICAST
&& !fl4
->flowi4_oif
)
2610 fib_select_default(&res
);
2613 fl4
->saddr
= FIB_RES_PREFSRC(net
, res
);
2615 dev_out
= FIB_RES_DEV(res
);
2616 fl4
->flowi4_oif
= dev_out
->ifindex
;
2620 rth
= __mkroute_output(&res
, fl4
, orig_daddr
, orig_saddr
, orig_oif
,
2625 hash
= rt_hash(orig_daddr
, orig_saddr
, orig_oif
,
2626 rt_genid(dev_net(dev_out
)));
2627 rth
= rt_intern_hash(hash
, rth
, NULL
, orig_oif
);
2635 struct rtable
*__ip_route_output_key(struct net
*net
, struct flowi4
*flp4
)
2640 if (!rt_caching(net
))
2643 hash
= rt_hash(flp4
->daddr
, flp4
->saddr
, flp4
->flowi4_oif
, rt_genid(net
));
2646 for (rth
= rcu_dereference_bh(rt_hash_table
[hash
].chain
); rth
;
2647 rth
= rcu_dereference_bh(rth
->dst
.rt_next
)) {
2648 if (rth
->rt_key_dst
== flp4
->daddr
&&
2649 rth
->rt_key_src
== flp4
->saddr
&&
2650 rt_is_output_route(rth
) &&
2651 rth
->rt_oif
== flp4
->flowi4_oif
&&
2652 rth
->rt_mark
== flp4
->flowi4_mark
&&
2653 !((rth
->rt_key_tos
^ flp4
->flowi4_tos
) &
2654 (IPTOS_RT_MASK
| RTO_ONLINK
)) &&
2655 net_eq(dev_net(rth
->dst
.dev
), net
) &&
2656 !rt_is_expired(rth
)) {
2657 dst_use(&rth
->dst
, jiffies
);
2658 RT_CACHE_STAT_INC(out_hit
);
2659 rcu_read_unlock_bh();
2661 flp4
->saddr
= rth
->rt_src
;
2663 flp4
->daddr
= rth
->rt_dst
;
2666 RT_CACHE_STAT_INC(out_hlist_search
);
2668 rcu_read_unlock_bh();
2671 return ip_route_output_slow(net
, flp4
);
2673 EXPORT_SYMBOL_GPL(__ip_route_output_key
);
2675 static struct dst_entry
*ipv4_blackhole_dst_check(struct dst_entry
*dst
, u32 cookie
)
2680 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry
*dst
)
2685 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry
*dst
, u32 mtu
)
2689 static u32
*ipv4_rt_blackhole_cow_metrics(struct dst_entry
*dst
,
2695 static struct dst_ops ipv4_dst_blackhole_ops
= {
2697 .protocol
= cpu_to_be16(ETH_P_IP
),
2698 .destroy
= ipv4_dst_destroy
,
2699 .check
= ipv4_blackhole_dst_check
,
2700 .default_mtu
= ipv4_blackhole_default_mtu
,
2701 .default_advmss
= ipv4_default_advmss
,
2702 .update_pmtu
= ipv4_rt_blackhole_update_pmtu
,
2703 .cow_metrics
= ipv4_rt_blackhole_cow_metrics
,
2706 struct dst_entry
*ipv4_blackhole_route(struct net
*net
, struct dst_entry
*dst_orig
)
2708 struct rtable
*rt
= dst_alloc(&ipv4_dst_blackhole_ops
, NULL
, 1, 0, 0);
2709 struct rtable
*ort
= (struct rtable
*) dst_orig
;
2712 struct dst_entry
*new = &rt
->dst
;
2715 new->input
= dst_discard
;
2716 new->output
= dst_discard
;
2717 dst_copy_metrics(new, &ort
->dst
);
2719 new->dev
= ort
->dst
.dev
;
2723 rt
->rt_key_dst
= ort
->rt_key_dst
;
2724 rt
->rt_key_src
= ort
->rt_key_src
;
2725 rt
->rt_key_tos
= ort
->rt_key_tos
;
2726 rt
->rt_route_iif
= ort
->rt_route_iif
;
2727 rt
->rt_iif
= ort
->rt_iif
;
2728 rt
->rt_oif
= ort
->rt_oif
;
2729 rt
->rt_mark
= ort
->rt_mark
;
2731 rt
->rt_genid
= rt_genid(net
);
2732 rt
->rt_flags
= ort
->rt_flags
;
2733 rt
->rt_type
= ort
->rt_type
;
2734 rt
->rt_dst
= ort
->rt_dst
;
2735 rt
->rt_src
= ort
->rt_src
;
2736 rt
->rt_gateway
= ort
->rt_gateway
;
2737 rt
->rt_spec_dst
= ort
->rt_spec_dst
;
2738 rt
->peer
= ort
->peer
;
2740 atomic_inc(&rt
->peer
->refcnt
);
2743 atomic_inc(&rt
->fi
->fib_clntref
);
2748 dst_release(dst_orig
);
2750 return rt
? &rt
->dst
: ERR_PTR(-ENOMEM
);
2753 struct rtable
*ip_route_output_flow(struct net
*net
, struct flowi4
*flp4
,
2756 struct rtable
*rt
= __ip_route_output_key(net
, flp4
);
2761 if (flp4
->flowi4_proto
)
2762 rt
= (struct rtable
*) xfrm_lookup(net
, &rt
->dst
,
2763 flowi4_to_flowi(flp4
),
2768 EXPORT_SYMBOL_GPL(ip_route_output_flow
);
2770 static int rt_fill_info(struct net
*net
,
2771 struct sk_buff
*skb
, u32 pid
, u32 seq
, int event
,
2772 int nowait
, unsigned int flags
)
2774 struct rtable
*rt
= skb_rtable(skb
);
2776 struct nlmsghdr
*nlh
;
2778 u32 id
= 0, ts
= 0, tsage
= 0, error
;
2780 nlh
= nlmsg_put(skb
, pid
, seq
, event
, sizeof(*r
), flags
);
2784 r
= nlmsg_data(nlh
);
2785 r
->rtm_family
= AF_INET
;
2786 r
->rtm_dst_len
= 32;
2788 r
->rtm_tos
= rt
->rt_key_tos
;
2789 r
->rtm_table
= RT_TABLE_MAIN
;
2790 NLA_PUT_U32(skb
, RTA_TABLE
, RT_TABLE_MAIN
);
2791 r
->rtm_type
= rt
->rt_type
;
2792 r
->rtm_scope
= RT_SCOPE_UNIVERSE
;
2793 r
->rtm_protocol
= RTPROT_UNSPEC
;
2794 r
->rtm_flags
= (rt
->rt_flags
& ~0xFFFF) | RTM_F_CLONED
;
2795 if (rt
->rt_flags
& RTCF_NOTIFY
)
2796 r
->rtm_flags
|= RTM_F_NOTIFY
;
2798 NLA_PUT_BE32(skb
, RTA_DST
, rt
->rt_dst
);
2800 if (rt
->rt_key_src
) {
2801 r
->rtm_src_len
= 32;
2802 NLA_PUT_BE32(skb
, RTA_SRC
, rt
->rt_key_src
);
2805 NLA_PUT_U32(skb
, RTA_OIF
, rt
->dst
.dev
->ifindex
);
2806 #ifdef CONFIG_IP_ROUTE_CLASSID
2807 if (rt
->dst
.tclassid
)
2808 NLA_PUT_U32(skb
, RTA_FLOW
, rt
->dst
.tclassid
);
2810 if (rt_is_input_route(rt
))
2811 NLA_PUT_BE32(skb
, RTA_PREFSRC
, rt
->rt_spec_dst
);
2812 else if (rt
->rt_src
!= rt
->rt_key_src
)
2813 NLA_PUT_BE32(skb
, RTA_PREFSRC
, rt
->rt_src
);
2815 if (rt
->rt_dst
!= rt
->rt_gateway
)
2816 NLA_PUT_BE32(skb
, RTA_GATEWAY
, rt
->rt_gateway
);
2818 if (rtnetlink_put_metrics(skb
, dst_metrics_ptr(&rt
->dst
)) < 0)
2819 goto nla_put_failure
;
2822 NLA_PUT_BE32(skb
, RTA_MARK
, rt
->rt_mark
);
2824 error
= rt
->dst
.error
;
2825 expires
= (rt
->peer
&& rt
->peer
->pmtu_expires
) ?
2826 rt
->peer
->pmtu_expires
- jiffies
: 0;
2828 inet_peer_refcheck(rt
->peer
);
2829 id
= atomic_read(&rt
->peer
->ip_id_count
) & 0xffff;
2830 if (rt
->peer
->tcp_ts_stamp
) {
2831 ts
= rt
->peer
->tcp_ts
;
2832 tsage
= get_seconds() - rt
->peer
->tcp_ts_stamp
;
2836 if (rt_is_input_route(rt
)) {
2837 #ifdef CONFIG_IP_MROUTE
2838 __be32 dst
= rt
->rt_dst
;
2840 if (ipv4_is_multicast(dst
) && !ipv4_is_local_multicast(dst
) &&
2841 IPV4_DEVCONF_ALL(net
, MC_FORWARDING
)) {
2842 int err
= ipmr_get_route(net
, skb
,
2843 rt
->rt_src
, rt
->rt_dst
,
2849 goto nla_put_failure
;
2851 if (err
== -EMSGSIZE
)
2852 goto nla_put_failure
;
2858 NLA_PUT_U32(skb
, RTA_IIF
, rt
->rt_iif
);
2861 if (rtnl_put_cacheinfo(skb
, &rt
->dst
, id
, ts
, tsage
,
2862 expires
, error
) < 0)
2863 goto nla_put_failure
;
2865 return nlmsg_end(skb
, nlh
);
2868 nlmsg_cancel(skb
, nlh
);
2872 static int inet_rtm_getroute(struct sk_buff
*in_skb
, struct nlmsghdr
* nlh
, void *arg
)
2874 struct net
*net
= sock_net(in_skb
->sk
);
2876 struct nlattr
*tb
[RTA_MAX
+1];
2877 struct rtable
*rt
= NULL
;
2883 struct sk_buff
*skb
;
2885 err
= nlmsg_parse(nlh
, sizeof(*rtm
), tb
, RTA_MAX
, rtm_ipv4_policy
);
2889 rtm
= nlmsg_data(nlh
);
2891 skb
= alloc_skb(NLMSG_GOODSIZE
, GFP_KERNEL
);
2897 /* Reserve room for dummy headers, this skb can pass
2898 through good chunk of routing engine.
2900 skb_reset_mac_header(skb
);
2901 skb_reset_network_header(skb
);
2903 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2904 ip_hdr(skb
)->protocol
= IPPROTO_ICMP
;
2905 skb_reserve(skb
, MAX_HEADER
+ sizeof(struct iphdr
));
2907 src
= tb
[RTA_SRC
] ? nla_get_be32(tb
[RTA_SRC
]) : 0;
2908 dst
= tb
[RTA_DST
] ? nla_get_be32(tb
[RTA_DST
]) : 0;
2909 iif
= tb
[RTA_IIF
] ? nla_get_u32(tb
[RTA_IIF
]) : 0;
2910 mark
= tb
[RTA_MARK
] ? nla_get_u32(tb
[RTA_MARK
]) : 0;
2913 struct net_device
*dev
;
2915 dev
= __dev_get_by_index(net
, iif
);
2921 skb
->protocol
= htons(ETH_P_IP
);
2925 err
= ip_route_input(skb
, dst
, src
, rtm
->rtm_tos
, dev
);
2928 rt
= skb_rtable(skb
);
2929 if (err
== 0 && rt
->dst
.error
)
2930 err
= -rt
->dst
.error
;
2932 struct flowi4 fl4
= {
2935 .flowi4_tos
= rtm
->rtm_tos
,
2936 .flowi4_oif
= tb
[RTA_OIF
] ? nla_get_u32(tb
[RTA_OIF
]) : 0,
2937 .flowi4_mark
= mark
,
2939 rt
= ip_route_output_key(net
, &fl4
);
2949 skb_dst_set(skb
, &rt
->dst
);
2950 if (rtm
->rtm_flags
& RTM_F_NOTIFY
)
2951 rt
->rt_flags
|= RTCF_NOTIFY
;
2953 err
= rt_fill_info(net
, skb
, NETLINK_CB(in_skb
).pid
, nlh
->nlmsg_seq
,
2954 RTM_NEWROUTE
, 0, 0);
2958 err
= rtnl_unicast(skb
, net
, NETLINK_CB(in_skb
).pid
);
2967 int ip_rt_dump(struct sk_buff
*skb
, struct netlink_callback
*cb
)
2974 net
= sock_net(skb
->sk
);
2979 s_idx
= idx
= cb
->args
[1];
2980 for (h
= s_h
; h
<= rt_hash_mask
; h
++, s_idx
= 0) {
2981 if (!rt_hash_table
[h
].chain
)
2984 for (rt
= rcu_dereference_bh(rt_hash_table
[h
].chain
), idx
= 0; rt
;
2985 rt
= rcu_dereference_bh(rt
->dst
.rt_next
), idx
++) {
2986 if (!net_eq(dev_net(rt
->dst
.dev
), net
) || idx
< s_idx
)
2988 if (rt_is_expired(rt
))
2990 skb_dst_set_noref(skb
, &rt
->dst
);
2991 if (rt_fill_info(net
, skb
, NETLINK_CB(cb
->skb
).pid
,
2992 cb
->nlh
->nlmsg_seq
, RTM_NEWROUTE
,
2993 1, NLM_F_MULTI
) <= 0) {
2995 rcu_read_unlock_bh();
3000 rcu_read_unlock_bh();
3009 void ip_rt_multicast_event(struct in_device
*in_dev
)
3011 rt_cache_flush(dev_net(in_dev
->dev
), 0);
3014 #ifdef CONFIG_SYSCTL
3015 static int ipv4_sysctl_rtcache_flush(ctl_table
*__ctl
, int write
,
3016 void __user
*buffer
,
3017 size_t *lenp
, loff_t
*ppos
)
3024 memcpy(&ctl
, __ctl
, sizeof(ctl
));
3025 ctl
.data
= &flush_delay
;
3026 proc_dointvec(&ctl
, write
, buffer
, lenp
, ppos
);
3028 net
= (struct net
*)__ctl
->extra1
;
3029 rt_cache_flush(net
, flush_delay
);
3036 static ctl_table ipv4_route_table
[] = {
3038 .procname
= "gc_thresh",
3039 .data
= &ipv4_dst_ops
.gc_thresh
,
3040 .maxlen
= sizeof(int),
3042 .proc_handler
= proc_dointvec
,
3045 .procname
= "max_size",
3046 .data
= &ip_rt_max_size
,
3047 .maxlen
= sizeof(int),
3049 .proc_handler
= proc_dointvec
,
3052 /* Deprecated. Use gc_min_interval_ms */
3054 .procname
= "gc_min_interval",
3055 .data
= &ip_rt_gc_min_interval
,
3056 .maxlen
= sizeof(int),
3058 .proc_handler
= proc_dointvec_jiffies
,
3061 .procname
= "gc_min_interval_ms",
3062 .data
= &ip_rt_gc_min_interval
,
3063 .maxlen
= sizeof(int),
3065 .proc_handler
= proc_dointvec_ms_jiffies
,
3068 .procname
= "gc_timeout",
3069 .data
= &ip_rt_gc_timeout
,
3070 .maxlen
= sizeof(int),
3072 .proc_handler
= proc_dointvec_jiffies
,
3075 .procname
= "gc_interval",
3076 .data
= &ip_rt_gc_interval
,
3077 .maxlen
= sizeof(int),
3079 .proc_handler
= proc_dointvec_jiffies
,
3082 .procname
= "redirect_load",
3083 .data
= &ip_rt_redirect_load
,
3084 .maxlen
= sizeof(int),
3086 .proc_handler
= proc_dointvec
,
3089 .procname
= "redirect_number",
3090 .data
= &ip_rt_redirect_number
,
3091 .maxlen
= sizeof(int),
3093 .proc_handler
= proc_dointvec
,
3096 .procname
= "redirect_silence",
3097 .data
= &ip_rt_redirect_silence
,
3098 .maxlen
= sizeof(int),
3100 .proc_handler
= proc_dointvec
,
3103 .procname
= "error_cost",
3104 .data
= &ip_rt_error_cost
,
3105 .maxlen
= sizeof(int),
3107 .proc_handler
= proc_dointvec
,
3110 .procname
= "error_burst",
3111 .data
= &ip_rt_error_burst
,
3112 .maxlen
= sizeof(int),
3114 .proc_handler
= proc_dointvec
,
3117 .procname
= "gc_elasticity",
3118 .data
= &ip_rt_gc_elasticity
,
3119 .maxlen
= sizeof(int),
3121 .proc_handler
= proc_dointvec
,
3124 .procname
= "mtu_expires",
3125 .data
= &ip_rt_mtu_expires
,
3126 .maxlen
= sizeof(int),
3128 .proc_handler
= proc_dointvec_jiffies
,
3131 .procname
= "min_pmtu",
3132 .data
= &ip_rt_min_pmtu
,
3133 .maxlen
= sizeof(int),
3135 .proc_handler
= proc_dointvec
,
3138 .procname
= "min_adv_mss",
3139 .data
= &ip_rt_min_advmss
,
3140 .maxlen
= sizeof(int),
3142 .proc_handler
= proc_dointvec
,
3147 static struct ctl_table empty
[1];
3149 static struct ctl_table ipv4_skeleton
[] =
3151 { .procname
= "route",
3152 .mode
= 0555, .child
= ipv4_route_table
},
3153 { .procname
= "neigh",
3154 .mode
= 0555, .child
= empty
},
3158 static __net_initdata
struct ctl_path ipv4_path
[] = {
3159 { .procname
= "net", },
3160 { .procname
= "ipv4", },
3164 static struct ctl_table ipv4_route_flush_table
[] = {
3166 .procname
= "flush",
3167 .maxlen
= sizeof(int),
3169 .proc_handler
= ipv4_sysctl_rtcache_flush
,
3174 static __net_initdata
struct ctl_path ipv4_route_path
[] = {
3175 { .procname
= "net", },
3176 { .procname
= "ipv4", },
3177 { .procname
= "route", },
3181 static __net_init
int sysctl_route_net_init(struct net
*net
)
3183 struct ctl_table
*tbl
;
3185 tbl
= ipv4_route_flush_table
;
3186 if (!net_eq(net
, &init_net
)) {
3187 tbl
= kmemdup(tbl
, sizeof(ipv4_route_flush_table
), GFP_KERNEL
);
3191 tbl
[0].extra1
= net
;
3193 net
->ipv4
.route_hdr
=
3194 register_net_sysctl_table(net
, ipv4_route_path
, tbl
);
3195 if (net
->ipv4
.route_hdr
== NULL
)
3200 if (tbl
!= ipv4_route_flush_table
)
3206 static __net_exit
void sysctl_route_net_exit(struct net
*net
)
3208 struct ctl_table
*tbl
;
3210 tbl
= net
->ipv4
.route_hdr
->ctl_table_arg
;
3211 unregister_net_sysctl_table(net
->ipv4
.route_hdr
);
3212 BUG_ON(tbl
== ipv4_route_flush_table
);
3216 static __net_initdata
struct pernet_operations sysctl_route_ops
= {
3217 .init
= sysctl_route_net_init
,
3218 .exit
= sysctl_route_net_exit
,
3222 static __net_init
int rt_genid_init(struct net
*net
)
3224 get_random_bytes(&net
->ipv4
.rt_genid
,
3225 sizeof(net
->ipv4
.rt_genid
));
3226 get_random_bytes(&net
->ipv4
.dev_addr_genid
,
3227 sizeof(net
->ipv4
.dev_addr_genid
));
3231 static __net_initdata
struct pernet_operations rt_genid_ops
= {
3232 .init
= rt_genid_init
,
3236 #ifdef CONFIG_IP_ROUTE_CLASSID
3237 struct ip_rt_acct __percpu
*ip_rt_acct __read_mostly
;
3238 #endif /* CONFIG_IP_ROUTE_CLASSID */
3240 static __initdata
unsigned long rhash_entries
;
3241 static int __init
set_rhash_entries(char *str
)
3245 rhash_entries
= simple_strtoul(str
, &str
, 0);
3248 __setup("rhash_entries=", set_rhash_entries
);
3250 int __init
ip_rt_init(void)
3254 #ifdef CONFIG_IP_ROUTE_CLASSID
3255 ip_rt_acct
= __alloc_percpu(256 * sizeof(struct ip_rt_acct
), __alignof__(struct ip_rt_acct
));
3257 panic("IP: failed to allocate ip_rt_acct\n");
3260 ipv4_dst_ops
.kmem_cachep
=
3261 kmem_cache_create("ip_dst_cache", sizeof(struct rtable
), 0,
3262 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3264 ipv4_dst_blackhole_ops
.kmem_cachep
= ipv4_dst_ops
.kmem_cachep
;
3266 if (dst_entries_init(&ipv4_dst_ops
) < 0)
3267 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3269 if (dst_entries_init(&ipv4_dst_blackhole_ops
) < 0)
3270 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3272 rt_hash_table
= (struct rt_hash_bucket
*)
3273 alloc_large_system_hash("IP route cache",
3274 sizeof(struct rt_hash_bucket
),
3276 (totalram_pages
>= 128 * 1024) ?
3281 rhash_entries
? 0 : 512 * 1024);
3282 memset(rt_hash_table
, 0, (rt_hash_mask
+ 1) * sizeof(struct rt_hash_bucket
));
3283 rt_hash_lock_init();
3285 ipv4_dst_ops
.gc_thresh
= (rt_hash_mask
+ 1);
3286 ip_rt_max_size
= (rt_hash_mask
+ 1) * 16;
3291 if (ip_rt_proc_init())
3292 printk(KERN_ERR
"Unable to create route proc files\n");
3295 xfrm4_init(ip_rt_max_size
);
3297 rtnl_register(PF_INET
, RTM_GETROUTE
, inet_rtm_getroute
, NULL
);
3299 #ifdef CONFIG_SYSCTL
3300 register_pernet_subsys(&sysctl_route_ops
);
3302 register_pernet_subsys(&rt_genid_ops
);
3306 #ifdef CONFIG_SYSCTL
3308 * We really need to sanitize the damn ipv4 init order, then all
3309 * this nonsense will go away.
3311 void __init
ip_static_sysctl_init(void)
3313 register_sysctl_paths(ipv4_path
, ipv4_skeleton
);