2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * ROUTE - implementation of the IP router.
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
65 #include <linux/module.h>
66 #include <asm/uaccess.h>
67 #include <asm/system.h>
68 #include <linux/bitops.h>
69 #include <linux/types.h>
70 #include <linux/kernel.h>
72 #include <linux/bootmem.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/workqueue.h>
83 #include <linux/skbuff.h>
84 #include <linux/inetdevice.h>
85 #include <linux/igmp.h>
86 #include <linux/pkt_sched.h>
87 #include <linux/mroute.h>
88 #include <linux/netfilter_ipv4.h>
89 #include <linux/random.h>
90 #include <linux/jhash.h>
91 #include <linux/rcupdate.h>
92 #include <linux/times.h>
93 #include <linux/slab.h>
95 #include <net/net_namespace.h>
96 #include <net/protocol.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/netevent.h>
107 #include <net/rtnetlink.h>
109 #include <linux/sysctl.h>
112 #define RT_FL_TOS(oldflp) \
113 ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
115 #define IP_MAX_MTU 0xFFF0
117 #define RT_GC_TIMEOUT (300*HZ)
119 static int ip_rt_max_size
;
120 static int ip_rt_gc_timeout __read_mostly
= RT_GC_TIMEOUT
;
121 static int ip_rt_gc_interval __read_mostly
= 60 * HZ
;
122 static int ip_rt_gc_min_interval __read_mostly
= HZ
/ 2;
123 static int ip_rt_redirect_number __read_mostly
= 9;
124 static int ip_rt_redirect_load __read_mostly
= HZ
/ 50;
125 static int ip_rt_redirect_silence __read_mostly
= ((HZ
/ 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly
= HZ
;
127 static int ip_rt_error_burst __read_mostly
= 5 * HZ
;
128 static int ip_rt_gc_elasticity __read_mostly
= 8;
129 static int ip_rt_mtu_expires __read_mostly
= 10 * 60 * HZ
;
130 static int ip_rt_min_pmtu __read_mostly
= 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly
= 256;
132 static int rt_chain_length_max __read_mostly
= 20;
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] = {
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 flowi
*fl1
,
715 const struct flowi
*fl2
)
717 return ((((__force u32
)fl1
->fl4_dst
^ (__force u32
)fl2
->fl4_dst
) |
718 ((__force u32
)fl1
->fl4_src
^ (__force u32
)fl2
->fl4_src
) |
719 (fl1
->iif
^ fl2
->iif
)) == 0);
722 static inline int compare_keys(struct flowi
*fl1
, struct flowi
*fl2
)
724 return (((__force u32
)fl1
->fl4_dst
^ (__force u32
)fl2
->fl4_dst
) |
725 ((__force u32
)fl1
->fl4_src
^ (__force u32
)fl2
->fl4_src
) |
726 (fl1
->mark
^ fl2
->mark
) |
727 (*(u16
*)&fl1
->fl4_tos
^ *(u16
*)&fl2
->fl4_tos
) |
728 (fl1
->oif
^ fl2
->oif
) |
729 (fl1
->iif
^ fl2
->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
->fl
, &rth
->fl
))
818 aux
= rcu_dereference_protected(aux
->dst
.rt_next
, 1);
824 * Pertubation 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
);
971 #if RT_CACHE_DEBUG >= 2
972 printk(KERN_DEBUG
"expire>> %u %d %d %d\n", expire
,
973 dst_entries_get_fast(&ipv4_dst_ops
), goal
, i
);
976 if (dst_entries_get_fast(&ipv4_dst_ops
) < ip_rt_max_size
)
978 } while (!in_softirq() && time_before_eq(jiffies
, now
));
980 if (dst_entries_get_fast(&ipv4_dst_ops
) < ip_rt_max_size
)
982 if (dst_entries_get_slow(&ipv4_dst_ops
) < ip_rt_max_size
)
985 printk(KERN_WARNING
"dst cache overflow\n");
986 RT_CACHE_STAT_INC(gc_dst_overflow
);
990 expire
+= ip_rt_gc_min_interval
;
991 if (expire
> ip_rt_gc_timeout
||
992 dst_entries_get_fast(&ipv4_dst_ops
) < ipv4_dst_ops
.gc_thresh
||
993 dst_entries_get_slow(&ipv4_dst_ops
) < ipv4_dst_ops
.gc_thresh
)
994 expire
= ip_rt_gc_timeout
;
995 #if RT_CACHE_DEBUG >= 2
996 printk(KERN_DEBUG
"expire++ %u %d %d %d\n", expire
,
997 dst_entries_get_fast(&ipv4_dst_ops
), goal
, rover
);
1003 * Returns number of entries in a hash chain that have different hash_inputs
1005 static int slow_chain_length(const struct rtable
*head
)
1008 const struct rtable
*rth
= head
;
1011 length
+= has_noalias(head
, rth
);
1012 rth
= rcu_dereference_protected(rth
->dst
.rt_next
, 1);
1014 return length
>> FRACT_BITS
;
1017 static int rt_intern_hash(unsigned hash
, struct rtable
*rt
,
1018 struct rtable
**rp
, struct sk_buff
*skb
, int ifindex
)
1020 struct rtable
*rth
, *cand
;
1021 struct rtable __rcu
**rthp
, **candp
;
1025 int attempts
= !in_softirq();
1029 min_score
= ~(u32
)0;
1034 if (!rt_caching(dev_net(rt
->dst
.dev
))) {
1036 * If we're not caching, just tell the caller we
1037 * were successful and don't touch the route. The
1038 * caller hold the sole reference to the cache entry, and
1039 * it will be released when the caller is done with it.
1040 * If we drop it here, the callers have no way to resolve routes
1041 * when we're not caching. Instead, just point *rp at rt, so
1042 * the caller gets a single use out of the route
1043 * Note that we do rt_free on this new route entry, so that
1044 * once its refcount hits zero, we are still able to reap it
1046 * Note: To avoid expensive rcu stuff for this uncached dst,
1047 * we set DST_NOCACHE so that dst_release() can free dst without
1048 * waiting a grace period.
1051 rt
->dst
.flags
|= DST_NOCACHE
;
1052 if (rt
->rt_type
== RTN_UNICAST
|| rt_is_output_route(rt
)) {
1053 int err
= arp_bind_neighbour(&rt
->dst
);
1055 if (net_ratelimit())
1057 "Neighbour table failure & not caching routes.\n");
1066 rthp
= &rt_hash_table
[hash
].chain
;
1068 spin_lock_bh(rt_hash_lock_addr(hash
));
1069 while ((rth
= rcu_dereference_protected(*rthp
,
1070 lockdep_is_held(rt_hash_lock_addr(hash
)))) != NULL
) {
1071 if (rt_is_expired(rth
)) {
1072 *rthp
= rth
->dst
.rt_next
;
1076 if (compare_keys(&rth
->fl
, &rt
->fl
) && compare_netns(rth
, rt
)) {
1078 *rthp
= rth
->dst
.rt_next
;
1080 * Since lookup is lockfree, the deletion
1081 * must be visible to another weakly ordered CPU before
1082 * the insertion at the start of the hash chain.
1084 rcu_assign_pointer(rth
->dst
.rt_next
,
1085 rt_hash_table
[hash
].chain
);
1087 * Since lookup is lockfree, the update writes
1088 * must be ordered for consistency on SMP.
1090 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rth
);
1092 dst_use(&rth
->dst
, now
);
1093 spin_unlock_bh(rt_hash_lock_addr(hash
));
1099 skb_dst_set(skb
, &rth
->dst
);
1103 if (!atomic_read(&rth
->dst
.__refcnt
)) {
1104 u32 score
= rt_score(rth
);
1106 if (score
<= min_score
) {
1115 rthp
= &rth
->dst
.rt_next
;
1119 /* ip_rt_gc_elasticity used to be average length of chain
1120 * length, when exceeded gc becomes really aggressive.
1122 * The second limit is less certain. At the moment it allows
1123 * only 2 entries per bucket. We will see.
1125 if (chain_length
> ip_rt_gc_elasticity
) {
1126 *candp
= cand
->dst
.rt_next
;
1130 if (chain_length
> rt_chain_length_max
&&
1131 slow_chain_length(rt_hash_table
[hash
].chain
) > rt_chain_length_max
) {
1132 struct net
*net
= dev_net(rt
->dst
.dev
);
1133 int num
= ++net
->ipv4
.current_rt_cache_rebuild_count
;
1134 if (!rt_caching(net
)) {
1135 printk(KERN_WARNING
"%s: %d rebuilds is over limit, route caching disabled\n",
1136 rt
->dst
.dev
->name
, num
);
1138 rt_emergency_hash_rebuild(net
);
1139 spin_unlock_bh(rt_hash_lock_addr(hash
));
1141 hash
= rt_hash(rt
->fl
.fl4_dst
, rt
->fl
.fl4_src
,
1142 ifindex
, rt_genid(net
));
1147 /* Try to bind route to arp only if it is output
1148 route or unicast forwarding path.
1150 if (rt
->rt_type
== RTN_UNICAST
|| rt_is_output_route(rt
)) {
1151 int err
= arp_bind_neighbour(&rt
->dst
);
1153 spin_unlock_bh(rt_hash_lock_addr(hash
));
1155 if (err
!= -ENOBUFS
) {
1160 /* Neighbour tables are full and nothing
1161 can be released. Try to shrink route cache,
1162 it is most likely it holds some neighbour records.
1164 if (attempts
-- > 0) {
1165 int saved_elasticity
= ip_rt_gc_elasticity
;
1166 int saved_int
= ip_rt_gc_min_interval
;
1167 ip_rt_gc_elasticity
= 1;
1168 ip_rt_gc_min_interval
= 0;
1169 rt_garbage_collect(&ipv4_dst_ops
);
1170 ip_rt_gc_min_interval
= saved_int
;
1171 ip_rt_gc_elasticity
= saved_elasticity
;
1175 if (net_ratelimit())
1176 printk(KERN_WARNING
"ipv4: Neighbour table overflow.\n");
1182 rt
->dst
.rt_next
= rt_hash_table
[hash
].chain
;
1184 #if RT_CACHE_DEBUG >= 2
1185 if (rt
->dst
.rt_next
) {
1187 printk(KERN_DEBUG
"rt_cache @%02x: %pI4",
1189 for (trt
= rt
->dst
.rt_next
; trt
; trt
= trt
->dst
.rt_next
)
1190 printk(" . %pI4", &trt
->rt_dst
);
1195 * Since lookup is lockfree, we must make sure
1196 * previous writes to rt are comitted to memory
1197 * before making rt visible to other CPUS.
1199 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rt
);
1201 spin_unlock_bh(rt_hash_lock_addr(hash
));
1207 skb_dst_set(skb
, &rt
->dst
);
1211 static atomic_t __rt_peer_genid
= ATOMIC_INIT(0);
1213 static u32
rt_peer_genid(void)
1215 return atomic_read(&__rt_peer_genid
);
1218 void rt_bind_peer(struct rtable
*rt
, int create
)
1220 struct inet_peer
*peer
;
1222 peer
= inet_getpeer_v4(rt
->rt_dst
, create
);
1224 if (peer
&& cmpxchg(&rt
->peer
, NULL
, peer
) != NULL
)
1227 rt
->rt_peer_genid
= rt_peer_genid();
1231 * Peer allocation may fail only in serious out-of-memory conditions. However
1232 * we still can generate some output.
1233 * Random ID selection looks a bit dangerous because we have no chances to
1234 * select ID being unique in a reasonable period of time.
1235 * But broken packet identifier may be better than no packet at all.
1237 static void ip_select_fb_ident(struct iphdr
*iph
)
1239 static DEFINE_SPINLOCK(ip_fb_id_lock
);
1240 static u32 ip_fallback_id
;
1243 spin_lock_bh(&ip_fb_id_lock
);
1244 salt
= secure_ip_id((__force __be32
)ip_fallback_id
^ iph
->daddr
);
1245 iph
->id
= htons(salt
& 0xFFFF);
1246 ip_fallback_id
= salt
;
1247 spin_unlock_bh(&ip_fb_id_lock
);
1250 void __ip_select_ident(struct iphdr
*iph
, struct dst_entry
*dst
, int more
)
1252 struct rtable
*rt
= (struct rtable
*) dst
;
1255 if (rt
->peer
== NULL
)
1256 rt_bind_peer(rt
, 1);
1258 /* If peer is attached to destination, it is never detached,
1259 so that we need not to grab a lock to dereference it.
1262 iph
->id
= htons(inet_getid(rt
->peer
, more
));
1266 printk(KERN_DEBUG
"rt_bind_peer(0) @%p\n",
1267 __builtin_return_address(0));
1269 ip_select_fb_ident(iph
);
1271 EXPORT_SYMBOL(__ip_select_ident
);
1273 static void rt_del(unsigned hash
, struct rtable
*rt
)
1275 struct rtable __rcu
**rthp
;
1278 rthp
= &rt_hash_table
[hash
].chain
;
1279 spin_lock_bh(rt_hash_lock_addr(hash
));
1281 while ((aux
= rcu_dereference_protected(*rthp
,
1282 lockdep_is_held(rt_hash_lock_addr(hash
)))) != NULL
) {
1283 if (aux
== rt
|| rt_is_expired(aux
)) {
1284 *rthp
= aux
->dst
.rt_next
;
1288 rthp
= &aux
->dst
.rt_next
;
1290 spin_unlock_bh(rt_hash_lock_addr(hash
));
1293 /* called in rcu_read_lock() section */
1294 void ip_rt_redirect(__be32 old_gw
, __be32 daddr
, __be32 new_gw
,
1295 __be32 saddr
, struct net_device
*dev
)
1297 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
1298 struct inet_peer
*peer
;
1305 if (new_gw
== old_gw
|| !IN_DEV_RX_REDIRECTS(in_dev
) ||
1306 ipv4_is_multicast(new_gw
) || ipv4_is_lbcast(new_gw
) ||
1307 ipv4_is_zeronet(new_gw
))
1308 goto reject_redirect
;
1310 if (!IN_DEV_SHARED_MEDIA(in_dev
)) {
1311 if (!inet_addr_onlink(in_dev
, new_gw
, old_gw
))
1312 goto reject_redirect
;
1313 if (IN_DEV_SEC_REDIRECTS(in_dev
) && ip_fib_check_default(new_gw
, dev
))
1314 goto reject_redirect
;
1316 if (inet_addr_type(net
, new_gw
) != RTN_UNICAST
)
1317 goto reject_redirect
;
1320 peer
= inet_getpeer_v4(daddr
, 1);
1322 peer
->redirect_learned
.a4
= new_gw
;
1326 atomic_inc(&__rt_peer_genid
);
1331 #ifdef CONFIG_IP_ROUTE_VERBOSE
1332 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit())
1333 printk(KERN_INFO
"Redirect from %pI4 on %s about %pI4 ignored.\n"
1334 " Advised path = %pI4 -> %pI4\n",
1335 &old_gw
, dev
->name
, &new_gw
,
1341 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
)
1343 struct rtable
*rt
= (struct rtable
*)dst
;
1344 struct dst_entry
*ret
= dst
;
1347 if (dst
->obsolete
> 0) {
1350 } else if (rt
->rt_flags
& RTCF_REDIRECTED
) {
1351 unsigned hash
= rt_hash(rt
->fl
.fl4_dst
, rt
->fl
.fl4_src
,
1353 rt_genid(dev_net(dst
->dev
)));
1354 #if RT_CACHE_DEBUG >= 1
1355 printk(KERN_DEBUG
"ipv4_negative_advice: redirect to %pI4/%02x dropped\n",
1356 &rt
->rt_dst
, rt
->fl
.fl4_tos
);
1360 } else if (rt
->peer
&&
1361 rt
->peer
->pmtu_expires
&&
1362 time_after_eq(jiffies
, rt
->peer
->pmtu_expires
)) {
1363 unsigned long orig
= rt
->peer
->pmtu_expires
;
1365 if (cmpxchg(&rt
->peer
->pmtu_expires
, orig
, 0) == orig
)
1366 dst_metric_set(dst
, RTAX_MTU
,
1367 rt
->peer
->pmtu_orig
);
1375 * 1. The first ip_rt_redirect_number redirects are sent
1376 * with exponential backoff, then we stop sending them at all,
1377 * assuming that the host ignores our redirects.
1378 * 2. If we did not see packets requiring redirects
1379 * during ip_rt_redirect_silence, we assume that the host
1380 * forgot redirected route and start to send redirects again.
1382 * This algorithm is much cheaper and more intelligent than dumb load limiting
1385 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1386 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1389 void ip_rt_send_redirect(struct sk_buff
*skb
)
1391 struct rtable
*rt
= skb_rtable(skb
);
1392 struct in_device
*in_dev
;
1393 struct inet_peer
*peer
;
1397 in_dev
= __in_dev_get_rcu(rt
->dst
.dev
);
1398 if (!in_dev
|| !IN_DEV_TX_REDIRECTS(in_dev
)) {
1402 log_martians
= IN_DEV_LOG_MARTIANS(in_dev
);
1406 rt_bind_peer(rt
, 1);
1409 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, rt
->rt_gateway
);
1413 /* No redirected packets during ip_rt_redirect_silence;
1414 * reset the algorithm.
1416 if (time_after(jiffies
, peer
->rate_last
+ ip_rt_redirect_silence
))
1417 peer
->rate_tokens
= 0;
1419 /* Too many ignored redirects; do not send anything
1420 * set dst.rate_last to the last seen redirected packet.
1422 if (peer
->rate_tokens
>= ip_rt_redirect_number
) {
1423 peer
->rate_last
= jiffies
;
1427 /* Check for load limit; set rate_last to the latest sent
1430 if (peer
->rate_tokens
== 0 ||
1433 (ip_rt_redirect_load
<< peer
->rate_tokens
)))) {
1434 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, rt
->rt_gateway
);
1435 peer
->rate_last
= jiffies
;
1436 ++peer
->rate_tokens
;
1437 #ifdef CONFIG_IP_ROUTE_VERBOSE
1439 peer
->rate_tokens
== ip_rt_redirect_number
&&
1441 printk(KERN_WARNING
"host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1442 &rt
->rt_src
, rt
->rt_iif
,
1443 &rt
->rt_dst
, &rt
->rt_gateway
);
1448 static int ip_error(struct sk_buff
*skb
)
1450 struct rtable
*rt
= skb_rtable(skb
);
1451 struct inet_peer
*peer
;
1456 switch (rt
->dst
.error
) {
1461 code
= ICMP_HOST_UNREACH
;
1464 code
= ICMP_NET_UNREACH
;
1465 IP_INC_STATS_BH(dev_net(rt
->dst
.dev
),
1466 IPSTATS_MIB_INNOROUTES
);
1469 code
= ICMP_PKT_FILTERED
;
1474 rt_bind_peer(rt
, 1);
1480 peer
->rate_tokens
+= now
- peer
->rate_last
;
1481 if (peer
->rate_tokens
> ip_rt_error_burst
)
1482 peer
->rate_tokens
= ip_rt_error_burst
;
1483 peer
->rate_last
= now
;
1484 if (peer
->rate_tokens
>= ip_rt_error_cost
)
1485 peer
->rate_tokens
-= ip_rt_error_cost
;
1490 icmp_send(skb
, ICMP_DEST_UNREACH
, code
, 0);
1492 out
: kfree_skb(skb
);
1497 * The last two values are not from the RFC but
1498 * are needed for AMPRnet AX.25 paths.
1501 static const unsigned short mtu_plateau
[] =
1502 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1504 static inline unsigned short guess_mtu(unsigned short old_mtu
)
1508 for (i
= 0; i
< ARRAY_SIZE(mtu_plateau
); i
++)
1509 if (old_mtu
> mtu_plateau
[i
])
1510 return mtu_plateau
[i
];
1514 unsigned short ip_rt_frag_needed(struct net
*net
, struct iphdr
*iph
,
1515 unsigned short new_mtu
,
1516 struct net_device
*dev
)
1518 unsigned short old_mtu
= ntohs(iph
->tot_len
);
1519 unsigned short est_mtu
= 0;
1520 struct inet_peer
*peer
;
1522 peer
= inet_getpeer_v4(iph
->daddr
, 1);
1524 unsigned short mtu
= new_mtu
;
1526 if (new_mtu
< 68 || new_mtu
>= old_mtu
) {
1527 /* BSD 4.2 derived systems incorrectly adjust
1528 * tot_len by the IP header length, and report
1529 * a zero MTU in the ICMP message.
1532 old_mtu
>= 68 + (iph
->ihl
<< 2))
1533 old_mtu
-= iph
->ihl
<< 2;
1534 mtu
= guess_mtu(old_mtu
);
1537 if (mtu
< ip_rt_min_pmtu
)
1538 mtu
= ip_rt_min_pmtu
;
1539 if (!peer
->pmtu_expires
|| mtu
< peer
->pmtu_learned
) {
1541 peer
->pmtu_learned
= mtu
;
1542 peer
->pmtu_expires
= jiffies
+ ip_rt_mtu_expires
;
1547 atomic_inc(&__rt_peer_genid
);
1549 return est_mtu
? : new_mtu
;
1552 static void check_peer_pmtu(struct dst_entry
*dst
, struct inet_peer
*peer
)
1554 unsigned long expires
= peer
->pmtu_expires
;
1556 if (time_before(expires
, jiffies
)) {
1557 u32 orig_dst_mtu
= dst_mtu(dst
);
1558 if (peer
->pmtu_learned
< orig_dst_mtu
) {
1559 if (!peer
->pmtu_orig
)
1560 peer
->pmtu_orig
= dst_metric_raw(dst
, RTAX_MTU
);
1561 dst_metric_set(dst
, RTAX_MTU
, peer
->pmtu_learned
);
1563 } else if (cmpxchg(&peer
->pmtu_expires
, expires
, 0) == expires
)
1564 dst_metric_set(dst
, RTAX_MTU
, peer
->pmtu_orig
);
1567 static void ip_rt_update_pmtu(struct dst_entry
*dst
, u32 mtu
)
1569 struct rtable
*rt
= (struct rtable
*) dst
;
1570 struct inet_peer
*peer
;
1575 rt_bind_peer(rt
, 1);
1578 if (mtu
< ip_rt_min_pmtu
)
1579 mtu
= ip_rt_min_pmtu
;
1580 if (!peer
->pmtu_expires
|| mtu
< peer
->pmtu_learned
) {
1581 peer
->pmtu_learned
= mtu
;
1582 peer
->pmtu_expires
= jiffies
+ ip_rt_mtu_expires
;
1584 atomic_inc(&__rt_peer_genid
);
1585 rt
->rt_peer_genid
= rt_peer_genid();
1587 check_peer_pmtu(dst
, peer
);
1593 static int check_peer_redir(struct dst_entry
*dst
, struct inet_peer
*peer
)
1595 struct rtable
*rt
= (struct rtable
*) dst
;
1596 __be32 orig_gw
= rt
->rt_gateway
;
1598 dst_confirm(&rt
->dst
);
1600 neigh_release(rt
->dst
.neighbour
);
1601 rt
->dst
.neighbour
= NULL
;
1603 rt
->rt_gateway
= peer
->redirect_learned
.a4
;
1604 if (arp_bind_neighbour(&rt
->dst
) ||
1605 !(rt
->dst
.neighbour
->nud_state
& NUD_VALID
)) {
1606 if (rt
->dst
.neighbour
)
1607 neigh_event_send(rt
->dst
.neighbour
, NULL
);
1608 rt
->rt_gateway
= orig_gw
;
1611 rt
->rt_flags
|= RTCF_REDIRECTED
;
1612 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE
,
1618 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
)
1620 struct rtable
*rt
= (struct rtable
*) dst
;
1622 if (rt_is_expired(rt
))
1624 if (rt
->rt_peer_genid
!= rt_peer_genid()) {
1625 struct inet_peer
*peer
;
1628 rt_bind_peer(rt
, 0);
1631 if (peer
&& peer
->pmtu_expires
)
1632 check_peer_pmtu(dst
, peer
);
1634 if (peer
&& peer
->redirect_learned
.a4
&&
1635 peer
->redirect_learned
.a4
!= rt
->rt_gateway
) {
1636 if (check_peer_redir(dst
, peer
))
1640 rt
->rt_peer_genid
= rt_peer_genid();
1645 static void ipv4_dst_destroy(struct dst_entry
*dst
)
1647 struct rtable
*rt
= (struct rtable
*) dst
;
1648 struct inet_peer
*peer
= rt
->peer
;
1651 fib_info_put(rt
->fi
);
1661 static void ipv4_link_failure(struct sk_buff
*skb
)
1665 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_HOST_UNREACH
, 0);
1667 rt
= skb_rtable(skb
);
1670 rt
->peer
->pmtu_expires
) {
1671 unsigned long orig
= rt
->peer
->pmtu_expires
;
1673 if (cmpxchg(&rt
->peer
->pmtu_expires
, orig
, 0) == orig
)
1674 dst_metric_set(&rt
->dst
, RTAX_MTU
, rt
->peer
->pmtu_orig
);
1678 static int ip_rt_bug(struct sk_buff
*skb
)
1680 printk(KERN_DEBUG
"ip_rt_bug: %pI4 -> %pI4, %s\n",
1681 &ip_hdr(skb
)->saddr
, &ip_hdr(skb
)->daddr
,
1682 skb
->dev
? skb
->dev
->name
: "?");
1688 We do not cache source address of outgoing interface,
1689 because it is used only by IP RR, TS and SRR options,
1690 so that it out of fast path.
1692 BTW remember: "addr" is allowed to be not aligned
1696 void ip_rt_get_source(u8
*addr
, struct rtable
*rt
)
1699 struct fib_result res
;
1701 if (rt_is_output_route(rt
))
1705 if (fib_lookup(dev_net(rt
->dst
.dev
), &rt
->fl
, &res
) == 0)
1706 src
= FIB_RES_PREFSRC(res
);
1708 src
= inet_select_addr(rt
->dst
.dev
, rt
->rt_gateway
,
1712 memcpy(addr
, &src
, 4);
1715 #ifdef CONFIG_IP_ROUTE_CLASSID
1716 static void set_class_tag(struct rtable
*rt
, u32 tag
)
1718 if (!(rt
->dst
.tclassid
& 0xFFFF))
1719 rt
->dst
.tclassid
|= tag
& 0xFFFF;
1720 if (!(rt
->dst
.tclassid
& 0xFFFF0000))
1721 rt
->dst
.tclassid
|= tag
& 0xFFFF0000;
1725 static unsigned int ipv4_default_advmss(const struct dst_entry
*dst
)
1727 unsigned int advmss
= dst_metric_raw(dst
, RTAX_ADVMSS
);
1730 advmss
= max_t(unsigned int, dst
->dev
->mtu
- 40,
1732 if (advmss
> 65535 - 40)
1733 advmss
= 65535 - 40;
1738 static unsigned int ipv4_default_mtu(const struct dst_entry
*dst
)
1740 unsigned int mtu
= dst
->dev
->mtu
;
1742 if (unlikely(dst_metric_locked(dst
, RTAX_MTU
))) {
1743 const struct rtable
*rt
= (const struct rtable
*) dst
;
1745 if (rt
->rt_gateway
!= rt
->rt_dst
&& mtu
> 576)
1749 if (mtu
> IP_MAX_MTU
)
1755 static void rt_init_metrics(struct rtable
*rt
, struct fib_info
*fi
)
1757 struct inet_peer
*peer
;
1760 /* If a peer entry exists for this destination, we must hook
1761 * it up in order to get at cached metrics.
1763 if (rt
->fl
.flags
& FLOWI_FLAG_PRECOW_METRICS
)
1766 rt_bind_peer(rt
, create
);
1769 if (inet_metrics_new(peer
))
1770 memcpy(peer
->metrics
, fi
->fib_metrics
,
1771 sizeof(u32
) * RTAX_MAX
);
1772 dst_init_metrics(&rt
->dst
, peer
->metrics
, false);
1774 if (peer
->pmtu_expires
)
1775 check_peer_pmtu(&rt
->dst
, peer
);
1776 if (peer
->redirect_learned
.a4
&&
1777 peer
->redirect_learned
.a4
!= rt
->rt_gateway
) {
1778 rt
->rt_gateway
= peer
->redirect_learned
.a4
;
1779 rt
->rt_flags
|= RTCF_REDIRECTED
;
1782 if (fi
->fib_metrics
!= (u32
*) dst_default_metrics
) {
1784 atomic_inc(&fi
->fib_clntref
);
1786 dst_init_metrics(&rt
->dst
, fi
->fib_metrics
, true);
1790 static void rt_set_nexthop(struct rtable
*rt
, const struct fib_result
*res
,
1791 struct fib_info
*fi
, u16 type
, u32 itag
)
1793 struct dst_entry
*dst
= &rt
->dst
;
1796 if (FIB_RES_GW(*res
) &&
1797 FIB_RES_NH(*res
).nh_scope
== RT_SCOPE_LINK
)
1798 rt
->rt_gateway
= FIB_RES_GW(*res
);
1799 rt_init_metrics(rt
, fi
);
1800 #ifdef CONFIG_IP_ROUTE_CLASSID
1801 dst
->tclassid
= FIB_RES_NH(*res
).nh_tclassid
;
1805 if (dst_mtu(dst
) > IP_MAX_MTU
)
1806 dst_metric_set(dst
, RTAX_MTU
, IP_MAX_MTU
);
1807 if (dst_metric_raw(dst
, RTAX_ADVMSS
) > 65535 - 40)
1808 dst_metric_set(dst
, RTAX_ADVMSS
, 65535 - 40);
1810 #ifdef CONFIG_IP_ROUTE_CLASSID
1811 #ifdef CONFIG_IP_MULTIPLE_TABLES
1812 set_class_tag(rt
, fib_rules_tclass(res
));
1814 set_class_tag(rt
, itag
);
1819 static struct rtable
*rt_dst_alloc(bool nopolicy
, bool noxfrm
)
1821 struct rtable
*rt
= dst_alloc(&ipv4_dst_ops
, 1);
1823 rt
->dst
.obsolete
= -1;
1825 rt
->dst
.flags
= DST_HOST
|
1826 (nopolicy
? DST_NOPOLICY
: 0) |
1827 (noxfrm
? DST_NOXFRM
: 0);
1832 /* called in rcu_read_lock() section */
1833 static int ip_route_input_mc(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
1834 u8 tos
, struct net_device
*dev
, int our
)
1839 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
1843 /* Primary sanity checks. */
1848 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
) ||
1849 ipv4_is_loopback(saddr
) || skb
->protocol
!= htons(ETH_P_IP
))
1852 if (ipv4_is_zeronet(saddr
)) {
1853 if (!ipv4_is_local_multicast(daddr
))
1855 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_LINK
);
1857 err
= fib_validate_source(saddr
, 0, tos
, 0, dev
, &spec_dst
,
1862 rth
= rt_dst_alloc(IN_DEV_CONF_GET(in_dev
, NOPOLICY
), false);
1866 rth
->dst
.output
= ip_rt_bug
;
1868 rth
->fl
.fl4_dst
= daddr
;
1869 rth
->rt_dst
= daddr
;
1870 rth
->fl
.fl4_tos
= tos
;
1871 rth
->fl
.mark
= skb
->mark
;
1872 rth
->fl
.fl4_src
= saddr
;
1873 rth
->rt_src
= saddr
;
1874 #ifdef CONFIG_IP_ROUTE_CLASSID
1875 rth
->dst
.tclassid
= itag
;
1878 rth
->fl
.iif
= dev
->ifindex
;
1879 rth
->dst
.dev
= init_net
.loopback_dev
;
1880 dev_hold(rth
->dst
.dev
);
1882 rth
->rt_gateway
= daddr
;
1883 rth
->rt_spec_dst
= spec_dst
;
1884 rth
->rt_genid
= rt_genid(dev_net(dev
));
1885 rth
->rt_flags
= RTCF_MULTICAST
;
1886 rth
->rt_type
= RTN_MULTICAST
;
1888 rth
->dst
.input
= ip_local_deliver
;
1889 rth
->rt_flags
|= RTCF_LOCAL
;
1892 #ifdef CONFIG_IP_MROUTE
1893 if (!ipv4_is_local_multicast(daddr
) && IN_DEV_MFORWARD(in_dev
))
1894 rth
->dst
.input
= ip_mr_input
;
1896 RT_CACHE_STAT_INC(in_slow_mc
);
1898 hash
= rt_hash(daddr
, saddr
, dev
->ifindex
, rt_genid(dev_net(dev
)));
1899 return rt_intern_hash(hash
, rth
, NULL
, skb
, dev
->ifindex
);
1910 static void ip_handle_martian_source(struct net_device
*dev
,
1911 struct in_device
*in_dev
,
1912 struct sk_buff
*skb
,
1916 RT_CACHE_STAT_INC(in_martian_src
);
1917 #ifdef CONFIG_IP_ROUTE_VERBOSE
1918 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit()) {
1920 * RFC1812 recommendation, if source is martian,
1921 * the only hint is MAC header.
1923 printk(KERN_WARNING
"martian source %pI4 from %pI4, on dev %s\n",
1924 &daddr
, &saddr
, dev
->name
);
1925 if (dev
->hard_header_len
&& skb_mac_header_was_set(skb
)) {
1927 const unsigned char *p
= skb_mac_header(skb
);
1928 printk(KERN_WARNING
"ll header: ");
1929 for (i
= 0; i
< dev
->hard_header_len
; i
++, p
++) {
1931 if (i
< (dev
->hard_header_len
- 1))
1940 /* called in rcu_read_lock() section */
1941 static int __mkroute_input(struct sk_buff
*skb
,
1942 const struct fib_result
*res
,
1943 struct in_device
*in_dev
,
1944 __be32 daddr
, __be32 saddr
, u32 tos
,
1945 struct rtable
**result
)
1949 struct in_device
*out_dev
;
1950 unsigned int flags
= 0;
1954 /* get a working reference to the output device */
1955 out_dev
= __in_dev_get_rcu(FIB_RES_DEV(*res
));
1956 if (out_dev
== NULL
) {
1957 if (net_ratelimit())
1958 printk(KERN_CRIT
"Bug in ip_route_input" \
1959 "_slow(). Please, report\n");
1964 err
= fib_validate_source(saddr
, daddr
, tos
, FIB_RES_OIF(*res
),
1965 in_dev
->dev
, &spec_dst
, &itag
, skb
->mark
);
1967 ip_handle_martian_source(in_dev
->dev
, in_dev
, skb
, daddr
,
1974 flags
|= RTCF_DIRECTSRC
;
1976 if (out_dev
== in_dev
&& err
&&
1977 (IN_DEV_SHARED_MEDIA(out_dev
) ||
1978 inet_addr_onlink(out_dev
, saddr
, FIB_RES_GW(*res
))))
1979 flags
|= RTCF_DOREDIRECT
;
1981 if (skb
->protocol
!= htons(ETH_P_IP
)) {
1982 /* Not IP (i.e. ARP). Do not create route, if it is
1983 * invalid for proxy arp. DNAT routes are always valid.
1985 * Proxy arp feature have been extended to allow, ARP
1986 * replies back to the same interface, to support
1987 * Private VLAN switch technologies. See arp.c.
1989 if (out_dev
== in_dev
&&
1990 IN_DEV_PROXY_ARP_PVLAN(in_dev
) == 0) {
1996 rth
= rt_dst_alloc(IN_DEV_CONF_GET(in_dev
, NOPOLICY
),
1997 IN_DEV_CONF_GET(out_dev
, NOXFRM
));
2003 rth
->fl
.fl4_dst
= daddr
;
2004 rth
->rt_dst
= daddr
;
2005 rth
->fl
.fl4_tos
= tos
;
2006 rth
->fl
.mark
= skb
->mark
;
2007 rth
->fl
.fl4_src
= saddr
;
2008 rth
->rt_src
= saddr
;
2009 rth
->rt_gateway
= daddr
;
2011 rth
->fl
.iif
= in_dev
->dev
->ifindex
;
2012 rth
->dst
.dev
= (out_dev
)->dev
;
2013 dev_hold(rth
->dst
.dev
);
2015 rth
->rt_spec_dst
= spec_dst
;
2017 rth
->dst
.input
= ip_forward
;
2018 rth
->dst
.output
= ip_output
;
2019 rth
->rt_genid
= rt_genid(dev_net(rth
->dst
.dev
));
2021 rt_set_nexthop(rth
, res
, res
->fi
, res
->type
, itag
);
2023 rth
->rt_flags
= flags
;
2031 static int ip_mkroute_input(struct sk_buff
*skb
,
2032 struct fib_result
*res
,
2033 const struct flowi
*fl
,
2034 struct in_device
*in_dev
,
2035 __be32 daddr
, __be32 saddr
, u32 tos
)
2037 struct rtable
* rth
= NULL
;
2041 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2042 if (res
->fi
&& res
->fi
->fib_nhs
> 1 && fl
->oif
== 0)
2043 fib_select_multipath(fl
, res
);
2046 /* create a routing cache entry */
2047 err
= __mkroute_input(skb
, res
, in_dev
, daddr
, saddr
, tos
, &rth
);
2051 /* put it into the cache */
2052 hash
= rt_hash(daddr
, saddr
, fl
->iif
,
2053 rt_genid(dev_net(rth
->dst
.dev
)));
2054 return rt_intern_hash(hash
, rth
, NULL
, skb
, fl
->iif
);
2058 * NOTE. We drop all the packets that has local source
2059 * addresses, because every properly looped back packet
2060 * must have correct destination already attached by output routine.
2062 * Such approach solves two big problems:
2063 * 1. Not simplex devices are handled properly.
2064 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2065 * called with rcu_read_lock()
2068 static int ip_route_input_slow(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2069 u8 tos
, struct net_device
*dev
)
2071 struct fib_result res
;
2072 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
2073 struct flowi fl
= { .fl4_dst
= daddr
,
2076 .fl4_scope
= RT_SCOPE_UNIVERSE
,
2078 .iif
= dev
->ifindex
};
2081 struct rtable
* rth
;
2085 struct net
* net
= dev_net(dev
);
2087 /* IP on this device is disabled. */
2092 /* Check for the most weird martians, which can be not detected
2096 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
) ||
2097 ipv4_is_loopback(saddr
))
2098 goto martian_source
;
2100 if (ipv4_is_lbcast(daddr
) || (saddr
== 0 && daddr
== 0))
2103 /* Accept zero addresses only to limited broadcast;
2104 * I even do not know to fix it or not. Waiting for complains :-)
2106 if (ipv4_is_zeronet(saddr
))
2107 goto martian_source
;
2109 if (ipv4_is_zeronet(daddr
) || ipv4_is_loopback(daddr
))
2110 goto martian_destination
;
2113 * Now we are ready to route packet.
2115 err
= fib_lookup(net
, &fl
, &res
);
2117 if (!IN_DEV_FORWARD(in_dev
))
2122 RT_CACHE_STAT_INC(in_slow_tot
);
2124 if (res
.type
== RTN_BROADCAST
)
2127 if (res
.type
== RTN_LOCAL
) {
2128 err
= fib_validate_source(saddr
, daddr
, tos
,
2129 net
->loopback_dev
->ifindex
,
2130 dev
, &spec_dst
, &itag
, skb
->mark
);
2132 goto martian_source_keep_err
;
2134 flags
|= RTCF_DIRECTSRC
;
2139 if (!IN_DEV_FORWARD(in_dev
))
2141 if (res
.type
!= RTN_UNICAST
)
2142 goto martian_destination
;
2144 err
= ip_mkroute_input(skb
, &res
, &fl
, in_dev
, daddr
, saddr
, tos
);
2148 if (skb
->protocol
!= htons(ETH_P_IP
))
2151 if (ipv4_is_zeronet(saddr
))
2152 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_LINK
);
2154 err
= fib_validate_source(saddr
, 0, tos
, 0, dev
, &spec_dst
,
2157 goto martian_source_keep_err
;
2159 flags
|= RTCF_DIRECTSRC
;
2161 flags
|= RTCF_BROADCAST
;
2162 res
.type
= RTN_BROADCAST
;
2163 RT_CACHE_STAT_INC(in_brd
);
2166 rth
= rt_dst_alloc(IN_DEV_CONF_GET(in_dev
, NOPOLICY
), false);
2170 rth
->dst
.output
= ip_rt_bug
;
2171 rth
->rt_genid
= rt_genid(net
);
2173 rth
->fl
.fl4_dst
= daddr
;
2174 rth
->rt_dst
= daddr
;
2175 rth
->fl
.fl4_tos
= tos
;
2176 rth
->fl
.mark
= skb
->mark
;
2177 rth
->fl
.fl4_src
= saddr
;
2178 rth
->rt_src
= saddr
;
2179 #ifdef CONFIG_IP_ROUTE_CLASSID
2180 rth
->dst
.tclassid
= itag
;
2183 rth
->fl
.iif
= dev
->ifindex
;
2184 rth
->dst
.dev
= net
->loopback_dev
;
2185 dev_hold(rth
->dst
.dev
);
2186 rth
->rt_gateway
= daddr
;
2187 rth
->rt_spec_dst
= spec_dst
;
2188 rth
->dst
.input
= ip_local_deliver
;
2189 rth
->rt_flags
= flags
|RTCF_LOCAL
;
2190 if (res
.type
== RTN_UNREACHABLE
) {
2191 rth
->dst
.input
= ip_error
;
2192 rth
->dst
.error
= -err
;
2193 rth
->rt_flags
&= ~RTCF_LOCAL
;
2195 rth
->rt_type
= res
.type
;
2196 hash
= rt_hash(daddr
, saddr
, fl
.iif
, rt_genid(net
));
2197 err
= rt_intern_hash(hash
, rth
, NULL
, skb
, fl
.iif
);
2201 RT_CACHE_STAT_INC(in_no_route
);
2202 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_UNIVERSE
);
2203 res
.type
= RTN_UNREACHABLE
;
2209 * Do not cache martian addresses: they should be logged (RFC1812)
2211 martian_destination
:
2212 RT_CACHE_STAT_INC(in_martian_dst
);
2213 #ifdef CONFIG_IP_ROUTE_VERBOSE
2214 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit())
2215 printk(KERN_WARNING
"martian destination %pI4 from %pI4, dev %s\n",
2216 &daddr
, &saddr
, dev
->name
);
2220 err
= -EHOSTUNREACH
;
2233 martian_source_keep_err
:
2234 ip_handle_martian_source(dev
, in_dev
, skb
, daddr
, saddr
);
2238 int ip_route_input_common(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2239 u8 tos
, struct net_device
*dev
, bool noref
)
2241 struct rtable
* rth
;
2243 int iif
= dev
->ifindex
;
2251 if (!rt_caching(net
))
2254 tos
&= IPTOS_RT_MASK
;
2255 hash
= rt_hash(daddr
, saddr
, iif
, rt_genid(net
));
2257 for (rth
= rcu_dereference(rt_hash_table
[hash
].chain
); rth
;
2258 rth
= rcu_dereference(rth
->dst
.rt_next
)) {
2259 if ((((__force u32
)rth
->fl
.fl4_dst
^ (__force u32
)daddr
) |
2260 ((__force u32
)rth
->fl
.fl4_src
^ (__force u32
)saddr
) |
2261 (rth
->fl
.iif
^ iif
) |
2263 (rth
->fl
.fl4_tos
^ tos
)) == 0 &&
2264 rth
->fl
.mark
== skb
->mark
&&
2265 net_eq(dev_net(rth
->dst
.dev
), net
) &&
2266 !rt_is_expired(rth
)) {
2268 dst_use_noref(&rth
->dst
, jiffies
);
2269 skb_dst_set_noref(skb
, &rth
->dst
);
2271 dst_use(&rth
->dst
, jiffies
);
2272 skb_dst_set(skb
, &rth
->dst
);
2274 RT_CACHE_STAT_INC(in_hit
);
2278 RT_CACHE_STAT_INC(in_hlist_search
);
2282 /* Multicast recognition logic is moved from route cache to here.
2283 The problem was that too many Ethernet cards have broken/missing
2284 hardware multicast filters :-( As result the host on multicasting
2285 network acquires a lot of useless route cache entries, sort of
2286 SDR messages from all the world. Now we try to get rid of them.
2287 Really, provided software IP multicast filter is organized
2288 reasonably (at least, hashed), it does not result in a slowdown
2289 comparing with route cache reject entries.
2290 Note, that multicast routers are not affected, because
2291 route cache entry is created eventually.
2293 if (ipv4_is_multicast(daddr
)) {
2294 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
2297 int our
= ip_check_mc(in_dev
, daddr
, saddr
,
2298 ip_hdr(skb
)->protocol
);
2300 #ifdef CONFIG_IP_MROUTE
2302 (!ipv4_is_local_multicast(daddr
) &&
2303 IN_DEV_MFORWARD(in_dev
))
2306 int res
= ip_route_input_mc(skb
, daddr
, saddr
,
2315 res
= ip_route_input_slow(skb
, daddr
, saddr
, tos
, dev
);
2319 EXPORT_SYMBOL(ip_route_input_common
);
2321 /* called with rcu_read_lock() */
2322 static struct rtable
*__mkroute_output(const struct fib_result
*res
,
2323 const struct flowi
*fl
,
2324 const struct flowi
*oldflp
,
2325 struct net_device
*dev_out
,
2328 struct fib_info
*fi
= res
->fi
;
2329 u32 tos
= RT_FL_TOS(oldflp
);
2330 struct in_device
*in_dev
;
2331 u16 type
= res
->type
;
2334 if (ipv4_is_loopback(fl
->fl4_src
) && !(dev_out
->flags
& IFF_LOOPBACK
))
2335 return ERR_PTR(-EINVAL
);
2337 if (ipv4_is_lbcast(fl
->fl4_dst
))
2338 type
= RTN_BROADCAST
;
2339 else if (ipv4_is_multicast(fl
->fl4_dst
))
2340 type
= RTN_MULTICAST
;
2341 else if (ipv4_is_zeronet(fl
->fl4_dst
))
2342 return ERR_PTR(-EINVAL
);
2344 if (dev_out
->flags
& IFF_LOOPBACK
)
2345 flags
|= RTCF_LOCAL
;
2347 in_dev
= __in_dev_get_rcu(dev_out
);
2349 return ERR_PTR(-EINVAL
);
2351 if (type
== RTN_BROADCAST
) {
2352 flags
|= RTCF_BROADCAST
| RTCF_LOCAL
;
2354 } else if (type
== RTN_MULTICAST
) {
2355 flags
|= RTCF_MULTICAST
| RTCF_LOCAL
;
2356 if (!ip_check_mc(in_dev
, oldflp
->fl4_dst
, oldflp
->fl4_src
,
2358 flags
&= ~RTCF_LOCAL
;
2359 /* If multicast route do not exist use
2360 * default one, but do not gateway in this case.
2363 if (fi
&& res
->prefixlen
< 4)
2367 rth
= rt_dst_alloc(IN_DEV_CONF_GET(in_dev
, NOPOLICY
),
2368 IN_DEV_CONF_GET(in_dev
, NOXFRM
));
2370 return ERR_PTR(-ENOBUFS
);
2372 rth
->fl
.fl4_dst
= oldflp
->fl4_dst
;
2373 rth
->fl
.fl4_tos
= tos
;
2374 rth
->fl
.fl4_src
= oldflp
->fl4_src
;
2375 rth
->fl
.oif
= oldflp
->oif
;
2376 rth
->fl
.mark
= oldflp
->mark
;
2377 rth
->rt_dst
= fl
->fl4_dst
;
2378 rth
->rt_src
= fl
->fl4_src
;
2379 rth
->rt_iif
= oldflp
->oif
? : dev_out
->ifindex
;
2380 /* get references to the devices that are to be hold by the routing
2382 rth
->dst
.dev
= dev_out
;
2384 rth
->rt_gateway
= fl
->fl4_dst
;
2385 rth
->rt_spec_dst
= fl
->fl4_src
;
2387 rth
->dst
.output
=ip_output
;
2388 rth
->rt_genid
= rt_genid(dev_net(dev_out
));
2390 RT_CACHE_STAT_INC(out_slow_tot
);
2392 if (flags
& RTCF_LOCAL
) {
2393 rth
->dst
.input
= ip_local_deliver
;
2394 rth
->rt_spec_dst
= fl
->fl4_dst
;
2396 if (flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) {
2397 rth
->rt_spec_dst
= fl
->fl4_src
;
2398 if (flags
& RTCF_LOCAL
&&
2399 !(dev_out
->flags
& IFF_LOOPBACK
)) {
2400 rth
->dst
.output
= ip_mc_output
;
2401 RT_CACHE_STAT_INC(out_slow_mc
);
2403 #ifdef CONFIG_IP_MROUTE
2404 if (type
== RTN_MULTICAST
) {
2405 if (IN_DEV_MFORWARD(in_dev
) &&
2406 !ipv4_is_local_multicast(oldflp
->fl4_dst
)) {
2407 rth
->dst
.input
= ip_mr_input
;
2408 rth
->dst
.output
= ip_mc_output
;
2414 rt_set_nexthop(rth
, res
, fi
, type
, 0);
2416 rth
->rt_flags
= flags
;
2421 * Major route resolver routine.
2422 * called with rcu_read_lock();
2425 static int ip_route_output_slow(struct net
*net
, struct rtable
**rp
,
2426 const struct flowi
*oldflp
)
2428 u32 tos
= RT_FL_TOS(oldflp
);
2429 struct flowi fl
= { .fl4_dst
= oldflp
->fl4_dst
,
2430 .fl4_src
= oldflp
->fl4_src
,
2431 .fl4_tos
= tos
& IPTOS_RT_MASK
,
2432 .fl4_scope
= ((tos
& RTO_ONLINK
) ?
2433 RT_SCOPE_LINK
: RT_SCOPE_UNIVERSE
),
2434 .mark
= oldflp
->mark
,
2435 .iif
= net
->loopback_dev
->ifindex
,
2436 .oif
= oldflp
->oif
};
2437 struct fib_result res
;
2438 unsigned int flags
= 0;
2439 struct net_device
*dev_out
= NULL
;
2445 #ifdef CONFIG_IP_MULTIPLE_TABLES
2450 if (oldflp
->fl4_src
) {
2452 if (ipv4_is_multicast(oldflp
->fl4_src
) ||
2453 ipv4_is_lbcast(oldflp
->fl4_src
) ||
2454 ipv4_is_zeronet(oldflp
->fl4_src
))
2457 /* I removed check for oif == dev_out->oif here.
2458 It was wrong for two reasons:
2459 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2460 is assigned to multiple interfaces.
2461 2. Moreover, we are allowed to send packets with saddr
2462 of another iface. --ANK
2465 if (oldflp
->oif
== 0 &&
2466 (ipv4_is_multicast(oldflp
->fl4_dst
) ||
2467 ipv4_is_lbcast(oldflp
->fl4_dst
))) {
2468 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2469 dev_out
= __ip_dev_find(net
, oldflp
->fl4_src
, false);
2470 if (dev_out
== NULL
)
2473 /* Special hack: user can direct multicasts
2474 and limited broadcast via necessary interface
2475 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2476 This hack is not just for fun, it allows
2477 vic,vat and friends to work.
2478 They bind socket to loopback, set ttl to zero
2479 and expect that it will work.
2480 From the viewpoint of routing cache they are broken,
2481 because we are not allowed to build multicast path
2482 with loopback source addr (look, routing cache
2483 cannot know, that ttl is zero, so that packet
2484 will not leave this host and route is valid).
2485 Luckily, this hack is good workaround.
2488 fl
.oif
= dev_out
->ifindex
;
2492 if (!(oldflp
->flags
& FLOWI_FLAG_ANYSRC
)) {
2493 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2494 if (!__ip_dev_find(net
, oldflp
->fl4_src
, false))
2501 dev_out
= dev_get_by_index_rcu(net
, oldflp
->oif
);
2503 if (dev_out
== NULL
)
2506 /* RACE: Check return value of inet_select_addr instead. */
2507 if (!(dev_out
->flags
& IFF_UP
) || !__in_dev_get_rcu(dev_out
)) {
2511 if (ipv4_is_local_multicast(oldflp
->fl4_dst
) ||
2512 ipv4_is_lbcast(oldflp
->fl4_dst
)) {
2514 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2519 if (ipv4_is_multicast(oldflp
->fl4_dst
))
2520 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2522 else if (!oldflp
->fl4_dst
)
2523 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2529 fl
.fl4_dst
= fl
.fl4_src
;
2531 fl
.fl4_dst
= fl
.fl4_src
= htonl(INADDR_LOOPBACK
);
2532 dev_out
= net
->loopback_dev
;
2533 fl
.oif
= net
->loopback_dev
->ifindex
;
2534 res
.type
= RTN_LOCAL
;
2535 flags
|= RTCF_LOCAL
;
2539 if (fib_lookup(net
, &fl
, &res
)) {
2542 /* Apparently, routing tables are wrong. Assume,
2543 that the destination is on link.
2546 Because we are allowed to send to iface
2547 even if it has NO routes and NO assigned
2548 addresses. When oif is specified, routing
2549 tables are looked up with only one purpose:
2550 to catch if destination is gatewayed, rather than
2551 direct. Moreover, if MSG_DONTROUTE is set,
2552 we send packet, ignoring both routing tables
2553 and ifaddr state. --ANK
2556 We could make it even if oif is unknown,
2557 likely IPv6, but we do not.
2560 if (fl
.fl4_src
== 0)
2561 fl
.fl4_src
= inet_select_addr(dev_out
, 0,
2563 res
.type
= RTN_UNICAST
;
2570 if (res
.type
== RTN_LOCAL
) {
2572 if (res
.fi
->fib_prefsrc
)
2573 fl
.fl4_src
= res
.fi
->fib_prefsrc
;
2575 fl
.fl4_src
= fl
.fl4_dst
;
2577 dev_out
= net
->loopback_dev
;
2578 fl
.oif
= dev_out
->ifindex
;
2580 flags
|= RTCF_LOCAL
;
2584 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2585 if (res
.fi
->fib_nhs
> 1 && fl
.oif
== 0)
2586 fib_select_multipath(&fl
, &res
);
2589 if (!res
.prefixlen
&& res
.type
== RTN_UNICAST
&& !fl
.oif
)
2590 fib_select_default(&res
);
2593 fl
.fl4_src
= FIB_RES_PREFSRC(res
);
2595 dev_out
= FIB_RES_DEV(res
);
2596 fl
.oif
= dev_out
->ifindex
;
2600 rth
= __mkroute_output(&res
, &fl
, oldflp
, dev_out
, flags
);
2606 hash
= rt_hash(oldflp
->fl4_dst
, oldflp
->fl4_src
, oldflp
->oif
,
2607 rt_genid(dev_net(dev_out
)));
2608 err
= rt_intern_hash(hash
, rth
, rp
, NULL
, oldflp
->oif
);
2616 int __ip_route_output_key(struct net
*net
, struct rtable
**rp
,
2617 const struct flowi
*flp
)
2622 if (!rt_caching(net
))
2625 hash
= rt_hash(flp
->fl4_dst
, flp
->fl4_src
, flp
->oif
, rt_genid(net
));
2628 for (rth
= rcu_dereference_bh(rt_hash_table
[hash
].chain
); rth
;
2629 rth
= rcu_dereference_bh(rth
->dst
.rt_next
)) {
2630 if (rth
->fl
.fl4_dst
== flp
->fl4_dst
&&
2631 rth
->fl
.fl4_src
== flp
->fl4_src
&&
2632 rt_is_output_route(rth
) &&
2633 rth
->fl
.oif
== flp
->oif
&&
2634 rth
->fl
.mark
== flp
->mark
&&
2635 !((rth
->fl
.fl4_tos
^ flp
->fl4_tos
) &
2636 (IPTOS_RT_MASK
| RTO_ONLINK
)) &&
2637 net_eq(dev_net(rth
->dst
.dev
), net
) &&
2638 !rt_is_expired(rth
)) {
2639 dst_use(&rth
->dst
, jiffies
);
2640 RT_CACHE_STAT_INC(out_hit
);
2641 rcu_read_unlock_bh();
2645 RT_CACHE_STAT_INC(out_hlist_search
);
2647 rcu_read_unlock_bh();
2650 return ip_route_output_slow(net
, rp
, flp
);
2652 EXPORT_SYMBOL_GPL(__ip_route_output_key
);
2654 static struct dst_entry
*ipv4_blackhole_dst_check(struct dst_entry
*dst
, u32 cookie
)
2659 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry
*dst
)
2664 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry
*dst
, u32 mtu
)
2668 static struct dst_ops ipv4_dst_blackhole_ops
= {
2670 .protocol
= cpu_to_be16(ETH_P_IP
),
2671 .destroy
= ipv4_dst_destroy
,
2672 .check
= ipv4_blackhole_dst_check
,
2673 .default_mtu
= ipv4_blackhole_default_mtu
,
2674 .default_advmss
= ipv4_default_advmss
,
2675 .update_pmtu
= ipv4_rt_blackhole_update_pmtu
,
2679 static int ipv4_dst_blackhole(struct net
*net
, struct rtable
**rp
, struct flowi
*flp
)
2681 struct rtable
*ort
= *rp
;
2682 struct rtable
*rt
= (struct rtable
*)
2683 dst_alloc(&ipv4_dst_blackhole_ops
, 1);
2686 struct dst_entry
*new = &rt
->dst
;
2689 new->input
= dst_discard
;
2690 new->output
= dst_discard
;
2691 dst_copy_metrics(new, &ort
->dst
);
2693 new->dev
= ort
->dst
.dev
;
2699 rt
->rt_genid
= rt_genid(net
);
2700 rt
->rt_flags
= ort
->rt_flags
;
2701 rt
->rt_type
= ort
->rt_type
;
2702 rt
->rt_dst
= ort
->rt_dst
;
2703 rt
->rt_src
= ort
->rt_src
;
2704 rt
->rt_iif
= ort
->rt_iif
;
2705 rt
->rt_gateway
= ort
->rt_gateway
;
2706 rt
->rt_spec_dst
= ort
->rt_spec_dst
;
2707 rt
->peer
= ort
->peer
;
2709 atomic_inc(&rt
->peer
->refcnt
);
2712 atomic_inc(&rt
->fi
->fib_clntref
);
2717 dst_release(&(*rp
)->dst
);
2719 return rt
? 0 : -ENOMEM
;
2722 int ip_route_output_flow(struct net
*net
, struct rtable
**rp
, struct flowi
*flp
,
2727 if ((err
= __ip_route_output_key(net
, rp
, flp
)) != 0)
2732 flp
->fl4_src
= (*rp
)->rt_src
;
2734 flp
->fl4_dst
= (*rp
)->rt_dst
;
2735 err
= __xfrm_lookup(net
, (struct dst_entry
**)rp
, flp
, sk
, 0);
2736 if (err
== -EREMOTE
)
2737 err
= ipv4_dst_blackhole(net
, rp
, flp
);
2744 EXPORT_SYMBOL_GPL(ip_route_output_flow
);
2746 int ip_route_output_key(struct net
*net
, struct rtable
**rp
, struct flowi
*flp
)
2748 return ip_route_output_flow(net
, rp
, flp
, NULL
);
2750 EXPORT_SYMBOL(ip_route_output_key
);
2752 static int rt_fill_info(struct net
*net
,
2753 struct sk_buff
*skb
, u32 pid
, u32 seq
, int event
,
2754 int nowait
, unsigned int flags
)
2756 struct rtable
*rt
= skb_rtable(skb
);
2758 struct nlmsghdr
*nlh
;
2760 u32 id
= 0, ts
= 0, tsage
= 0, error
;
2762 nlh
= nlmsg_put(skb
, pid
, seq
, event
, sizeof(*r
), flags
);
2766 r
= nlmsg_data(nlh
);
2767 r
->rtm_family
= AF_INET
;
2768 r
->rtm_dst_len
= 32;
2770 r
->rtm_tos
= rt
->fl
.fl4_tos
;
2771 r
->rtm_table
= RT_TABLE_MAIN
;
2772 NLA_PUT_U32(skb
, RTA_TABLE
, RT_TABLE_MAIN
);
2773 r
->rtm_type
= rt
->rt_type
;
2774 r
->rtm_scope
= RT_SCOPE_UNIVERSE
;
2775 r
->rtm_protocol
= RTPROT_UNSPEC
;
2776 r
->rtm_flags
= (rt
->rt_flags
& ~0xFFFF) | RTM_F_CLONED
;
2777 if (rt
->rt_flags
& RTCF_NOTIFY
)
2778 r
->rtm_flags
|= RTM_F_NOTIFY
;
2780 NLA_PUT_BE32(skb
, RTA_DST
, rt
->rt_dst
);
2782 if (rt
->fl
.fl4_src
) {
2783 r
->rtm_src_len
= 32;
2784 NLA_PUT_BE32(skb
, RTA_SRC
, rt
->fl
.fl4_src
);
2787 NLA_PUT_U32(skb
, RTA_OIF
, rt
->dst
.dev
->ifindex
);
2788 #ifdef CONFIG_IP_ROUTE_CLASSID
2789 if (rt
->dst
.tclassid
)
2790 NLA_PUT_U32(skb
, RTA_FLOW
, rt
->dst
.tclassid
);
2792 if (rt_is_input_route(rt
))
2793 NLA_PUT_BE32(skb
, RTA_PREFSRC
, rt
->rt_spec_dst
);
2794 else if (rt
->rt_src
!= rt
->fl
.fl4_src
)
2795 NLA_PUT_BE32(skb
, RTA_PREFSRC
, rt
->rt_src
);
2797 if (rt
->rt_dst
!= rt
->rt_gateway
)
2798 NLA_PUT_BE32(skb
, RTA_GATEWAY
, rt
->rt_gateway
);
2800 if (rtnetlink_put_metrics(skb
, dst_metrics_ptr(&rt
->dst
)) < 0)
2801 goto nla_put_failure
;
2804 NLA_PUT_BE32(skb
, RTA_MARK
, rt
->fl
.mark
);
2806 error
= rt
->dst
.error
;
2807 expires
= (rt
->peer
&& rt
->peer
->pmtu_expires
) ?
2808 rt
->peer
->pmtu_expires
- jiffies
: 0;
2810 inet_peer_refcheck(rt
->peer
);
2811 id
= atomic_read(&rt
->peer
->ip_id_count
) & 0xffff;
2812 if (rt
->peer
->tcp_ts_stamp
) {
2813 ts
= rt
->peer
->tcp_ts
;
2814 tsage
= get_seconds() - rt
->peer
->tcp_ts_stamp
;
2818 if (rt_is_input_route(rt
)) {
2819 #ifdef CONFIG_IP_MROUTE
2820 __be32 dst
= rt
->rt_dst
;
2822 if (ipv4_is_multicast(dst
) && !ipv4_is_local_multicast(dst
) &&
2823 IPV4_DEVCONF_ALL(net
, MC_FORWARDING
)) {
2824 int err
= ipmr_get_route(net
, skb
, r
, nowait
);
2829 goto nla_put_failure
;
2831 if (err
== -EMSGSIZE
)
2832 goto nla_put_failure
;
2838 NLA_PUT_U32(skb
, RTA_IIF
, rt
->fl
.iif
);
2841 if (rtnl_put_cacheinfo(skb
, &rt
->dst
, id
, ts
, tsage
,
2842 expires
, error
) < 0)
2843 goto nla_put_failure
;
2845 return nlmsg_end(skb
, nlh
);
2848 nlmsg_cancel(skb
, nlh
);
2852 static int inet_rtm_getroute(struct sk_buff
*in_skb
, struct nlmsghdr
* nlh
, void *arg
)
2854 struct net
*net
= sock_net(in_skb
->sk
);
2856 struct nlattr
*tb
[RTA_MAX
+1];
2857 struct rtable
*rt
= NULL
;
2863 struct sk_buff
*skb
;
2865 err
= nlmsg_parse(nlh
, sizeof(*rtm
), tb
, RTA_MAX
, rtm_ipv4_policy
);
2869 rtm
= nlmsg_data(nlh
);
2871 skb
= alloc_skb(NLMSG_GOODSIZE
, GFP_KERNEL
);
2877 /* Reserve room for dummy headers, this skb can pass
2878 through good chunk of routing engine.
2880 skb_reset_mac_header(skb
);
2881 skb_reset_network_header(skb
);
2883 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2884 ip_hdr(skb
)->protocol
= IPPROTO_ICMP
;
2885 skb_reserve(skb
, MAX_HEADER
+ sizeof(struct iphdr
));
2887 src
= tb
[RTA_SRC
] ? nla_get_be32(tb
[RTA_SRC
]) : 0;
2888 dst
= tb
[RTA_DST
] ? nla_get_be32(tb
[RTA_DST
]) : 0;
2889 iif
= tb
[RTA_IIF
] ? nla_get_u32(tb
[RTA_IIF
]) : 0;
2890 mark
= tb
[RTA_MARK
] ? nla_get_u32(tb
[RTA_MARK
]) : 0;
2893 struct net_device
*dev
;
2895 dev
= __dev_get_by_index(net
, iif
);
2901 skb
->protocol
= htons(ETH_P_IP
);
2905 err
= ip_route_input(skb
, dst
, src
, rtm
->rtm_tos
, dev
);
2908 rt
= skb_rtable(skb
);
2909 if (err
== 0 && rt
->dst
.error
)
2910 err
= -rt
->dst
.error
;
2915 .fl4_tos
= rtm
->rtm_tos
,
2916 .oif
= tb
[RTA_OIF
] ? nla_get_u32(tb
[RTA_OIF
]) : 0,
2919 err
= ip_route_output_key(net
, &rt
, &fl
);
2925 skb_dst_set(skb
, &rt
->dst
);
2926 if (rtm
->rtm_flags
& RTM_F_NOTIFY
)
2927 rt
->rt_flags
|= RTCF_NOTIFY
;
2929 err
= rt_fill_info(net
, skb
, NETLINK_CB(in_skb
).pid
, nlh
->nlmsg_seq
,
2930 RTM_NEWROUTE
, 0, 0);
2934 err
= rtnl_unicast(skb
, net
, NETLINK_CB(in_skb
).pid
);
2943 int ip_rt_dump(struct sk_buff
*skb
, struct netlink_callback
*cb
)
2950 net
= sock_net(skb
->sk
);
2955 s_idx
= idx
= cb
->args
[1];
2956 for (h
= s_h
; h
<= rt_hash_mask
; h
++, s_idx
= 0) {
2957 if (!rt_hash_table
[h
].chain
)
2960 for (rt
= rcu_dereference_bh(rt_hash_table
[h
].chain
), idx
= 0; rt
;
2961 rt
= rcu_dereference_bh(rt
->dst
.rt_next
), idx
++) {
2962 if (!net_eq(dev_net(rt
->dst
.dev
), net
) || idx
< s_idx
)
2964 if (rt_is_expired(rt
))
2966 skb_dst_set_noref(skb
, &rt
->dst
);
2967 if (rt_fill_info(net
, skb
, NETLINK_CB(cb
->skb
).pid
,
2968 cb
->nlh
->nlmsg_seq
, RTM_NEWROUTE
,
2969 1, NLM_F_MULTI
) <= 0) {
2971 rcu_read_unlock_bh();
2976 rcu_read_unlock_bh();
2985 void ip_rt_multicast_event(struct in_device
*in_dev
)
2987 rt_cache_flush(dev_net(in_dev
->dev
), 0);
2990 #ifdef CONFIG_SYSCTL
2991 static int ipv4_sysctl_rtcache_flush(ctl_table
*__ctl
, int write
,
2992 void __user
*buffer
,
2993 size_t *lenp
, loff_t
*ppos
)
3000 memcpy(&ctl
, __ctl
, sizeof(ctl
));
3001 ctl
.data
= &flush_delay
;
3002 proc_dointvec(&ctl
, write
, buffer
, lenp
, ppos
);
3004 net
= (struct net
*)__ctl
->extra1
;
3005 rt_cache_flush(net
, flush_delay
);
3012 static ctl_table ipv4_route_table
[] = {
3014 .procname
= "gc_thresh",
3015 .data
= &ipv4_dst_ops
.gc_thresh
,
3016 .maxlen
= sizeof(int),
3018 .proc_handler
= proc_dointvec
,
3021 .procname
= "max_size",
3022 .data
= &ip_rt_max_size
,
3023 .maxlen
= sizeof(int),
3025 .proc_handler
= proc_dointvec
,
3028 /* Deprecated. Use gc_min_interval_ms */
3030 .procname
= "gc_min_interval",
3031 .data
= &ip_rt_gc_min_interval
,
3032 .maxlen
= sizeof(int),
3034 .proc_handler
= proc_dointvec_jiffies
,
3037 .procname
= "gc_min_interval_ms",
3038 .data
= &ip_rt_gc_min_interval
,
3039 .maxlen
= sizeof(int),
3041 .proc_handler
= proc_dointvec_ms_jiffies
,
3044 .procname
= "gc_timeout",
3045 .data
= &ip_rt_gc_timeout
,
3046 .maxlen
= sizeof(int),
3048 .proc_handler
= proc_dointvec_jiffies
,
3051 .procname
= "gc_interval",
3052 .data
= &ip_rt_gc_interval
,
3053 .maxlen
= sizeof(int),
3055 .proc_handler
= proc_dointvec_jiffies
,
3058 .procname
= "redirect_load",
3059 .data
= &ip_rt_redirect_load
,
3060 .maxlen
= sizeof(int),
3062 .proc_handler
= proc_dointvec
,
3065 .procname
= "redirect_number",
3066 .data
= &ip_rt_redirect_number
,
3067 .maxlen
= sizeof(int),
3069 .proc_handler
= proc_dointvec
,
3072 .procname
= "redirect_silence",
3073 .data
= &ip_rt_redirect_silence
,
3074 .maxlen
= sizeof(int),
3076 .proc_handler
= proc_dointvec
,
3079 .procname
= "error_cost",
3080 .data
= &ip_rt_error_cost
,
3081 .maxlen
= sizeof(int),
3083 .proc_handler
= proc_dointvec
,
3086 .procname
= "error_burst",
3087 .data
= &ip_rt_error_burst
,
3088 .maxlen
= sizeof(int),
3090 .proc_handler
= proc_dointvec
,
3093 .procname
= "gc_elasticity",
3094 .data
= &ip_rt_gc_elasticity
,
3095 .maxlen
= sizeof(int),
3097 .proc_handler
= proc_dointvec
,
3100 .procname
= "mtu_expires",
3101 .data
= &ip_rt_mtu_expires
,
3102 .maxlen
= sizeof(int),
3104 .proc_handler
= proc_dointvec_jiffies
,
3107 .procname
= "min_pmtu",
3108 .data
= &ip_rt_min_pmtu
,
3109 .maxlen
= sizeof(int),
3111 .proc_handler
= proc_dointvec
,
3114 .procname
= "min_adv_mss",
3115 .data
= &ip_rt_min_advmss
,
3116 .maxlen
= sizeof(int),
3118 .proc_handler
= proc_dointvec
,
3123 static struct ctl_table empty
[1];
3125 static struct ctl_table ipv4_skeleton
[] =
3127 { .procname
= "route",
3128 .mode
= 0555, .child
= ipv4_route_table
},
3129 { .procname
= "neigh",
3130 .mode
= 0555, .child
= empty
},
3134 static __net_initdata
struct ctl_path ipv4_path
[] = {
3135 { .procname
= "net", },
3136 { .procname
= "ipv4", },
3140 static struct ctl_table ipv4_route_flush_table
[] = {
3142 .procname
= "flush",
3143 .maxlen
= sizeof(int),
3145 .proc_handler
= ipv4_sysctl_rtcache_flush
,
3150 static __net_initdata
struct ctl_path ipv4_route_path
[] = {
3151 { .procname
= "net", },
3152 { .procname
= "ipv4", },
3153 { .procname
= "route", },
3157 static __net_init
int sysctl_route_net_init(struct net
*net
)
3159 struct ctl_table
*tbl
;
3161 tbl
= ipv4_route_flush_table
;
3162 if (!net_eq(net
, &init_net
)) {
3163 tbl
= kmemdup(tbl
, sizeof(ipv4_route_flush_table
), GFP_KERNEL
);
3167 tbl
[0].extra1
= net
;
3169 net
->ipv4
.route_hdr
=
3170 register_net_sysctl_table(net
, ipv4_route_path
, tbl
);
3171 if (net
->ipv4
.route_hdr
== NULL
)
3176 if (tbl
!= ipv4_route_flush_table
)
3182 static __net_exit
void sysctl_route_net_exit(struct net
*net
)
3184 struct ctl_table
*tbl
;
3186 tbl
= net
->ipv4
.route_hdr
->ctl_table_arg
;
3187 unregister_net_sysctl_table(net
->ipv4
.route_hdr
);
3188 BUG_ON(tbl
== ipv4_route_flush_table
);
3192 static __net_initdata
struct pernet_operations sysctl_route_ops
= {
3193 .init
= sysctl_route_net_init
,
3194 .exit
= sysctl_route_net_exit
,
3198 static __net_init
int rt_genid_init(struct net
*net
)
3200 get_random_bytes(&net
->ipv4
.rt_genid
,
3201 sizeof(net
->ipv4
.rt_genid
));
3205 static __net_initdata
struct pernet_operations rt_genid_ops
= {
3206 .init
= rt_genid_init
,
3210 #ifdef CONFIG_IP_ROUTE_CLASSID
3211 struct ip_rt_acct __percpu
*ip_rt_acct __read_mostly
;
3212 #endif /* CONFIG_IP_ROUTE_CLASSID */
3214 static __initdata
unsigned long rhash_entries
;
3215 static int __init
set_rhash_entries(char *str
)
3219 rhash_entries
= simple_strtoul(str
, &str
, 0);
3222 __setup("rhash_entries=", set_rhash_entries
);
3224 int __init
ip_rt_init(void)
3228 #ifdef CONFIG_IP_ROUTE_CLASSID
3229 ip_rt_acct
= __alloc_percpu(256 * sizeof(struct ip_rt_acct
), __alignof__(struct ip_rt_acct
));
3231 panic("IP: failed to allocate ip_rt_acct\n");
3234 ipv4_dst_ops
.kmem_cachep
=
3235 kmem_cache_create("ip_dst_cache", sizeof(struct rtable
), 0,
3236 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3238 ipv4_dst_blackhole_ops
.kmem_cachep
= ipv4_dst_ops
.kmem_cachep
;
3240 if (dst_entries_init(&ipv4_dst_ops
) < 0)
3241 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3243 if (dst_entries_init(&ipv4_dst_blackhole_ops
) < 0)
3244 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3246 rt_hash_table
= (struct rt_hash_bucket
*)
3247 alloc_large_system_hash("IP route cache",
3248 sizeof(struct rt_hash_bucket
),
3250 (totalram_pages
>= 128 * 1024) ?
3255 rhash_entries
? 0 : 512 * 1024);
3256 memset(rt_hash_table
, 0, (rt_hash_mask
+ 1) * sizeof(struct rt_hash_bucket
));
3257 rt_hash_lock_init();
3259 ipv4_dst_ops
.gc_thresh
= (rt_hash_mask
+ 1);
3260 ip_rt_max_size
= (rt_hash_mask
+ 1) * 16;
3265 if (ip_rt_proc_init())
3266 printk(KERN_ERR
"Unable to create route proc files\n");
3269 xfrm4_init(ip_rt_max_size
);
3271 rtnl_register(PF_INET
, RTM_GETROUTE
, inet_rtm_getroute
, NULL
);
3273 #ifdef CONFIG_SYSCTL
3274 register_pernet_subsys(&sysctl_route_ops
);
3276 register_pernet_subsys(&rt_genid_ops
);
3280 #ifdef CONFIG_SYSCTL
3282 * We really need to sanitize the damn ipv4 init order, then all
3283 * this nonsense will go away.
3285 void __init
ip_static_sysctl_init(void)
3287 register_sysctl_paths(ipv4_path
, ipv4_skeleton
);