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>
111 #include <net/atmclip.h>
113 #define RT_FL_TOS(oldflp4) \
114 ((u32)(oldflp4->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
116 #define IP_MAX_MTU 0xFFF0
118 #define RT_GC_TIMEOUT (300*HZ)
120 static int ip_rt_max_size
;
121 static int ip_rt_gc_timeout __read_mostly
= RT_GC_TIMEOUT
;
122 static int ip_rt_gc_interval __read_mostly
= 60 * HZ
;
123 static int ip_rt_gc_min_interval __read_mostly
= HZ
/ 2;
124 static int ip_rt_redirect_number __read_mostly
= 9;
125 static int ip_rt_redirect_load __read_mostly
= HZ
/ 50;
126 static int ip_rt_redirect_silence __read_mostly
= ((HZ
/ 50) << (9 + 1));
127 static int ip_rt_error_cost __read_mostly
= HZ
;
128 static int ip_rt_error_burst __read_mostly
= 5 * HZ
;
129 static int ip_rt_gc_elasticity __read_mostly
= 8;
130 static int ip_rt_mtu_expires __read_mostly
= 10 * 60 * HZ
;
131 static int ip_rt_min_pmtu __read_mostly
= 512 + 20 + 20;
132 static int ip_rt_min_advmss __read_mostly
= 256;
133 static int rt_chain_length_max __read_mostly
= 20;
136 * Interface to generic destination cache.
139 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
);
140 static unsigned int ipv4_default_advmss(const struct dst_entry
*dst
);
141 static unsigned int ipv4_default_mtu(const struct dst_entry
*dst
);
142 static void ipv4_dst_destroy(struct dst_entry
*dst
);
143 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
);
144 static void ipv4_link_failure(struct sk_buff
*skb
);
145 static void ip_rt_update_pmtu(struct dst_entry
*dst
, u32 mtu
);
146 static int rt_garbage_collect(struct dst_ops
*ops
);
148 static void ipv4_dst_ifdown(struct dst_entry
*dst
, struct net_device
*dev
,
153 static u32
*ipv4_cow_metrics(struct dst_entry
*dst
, unsigned long old
)
155 struct rtable
*rt
= (struct rtable
*) dst
;
156 struct inet_peer
*peer
;
160 rt_bind_peer(rt
, rt
->rt_dst
, 1);
164 u32
*old_p
= __DST_METRICS_PTR(old
);
165 unsigned long prev
, new;
168 if (inet_metrics_new(peer
))
169 memcpy(p
, old_p
, sizeof(u32
) * RTAX_MAX
);
171 new = (unsigned long) p
;
172 prev
= cmpxchg(&dst
->_metrics
, old
, new);
175 p
= __DST_METRICS_PTR(prev
);
176 if (prev
& DST_METRICS_READ_ONLY
)
180 fib_info_put(rt
->fi
);
188 static struct dst_ops ipv4_dst_ops
= {
190 .protocol
= cpu_to_be16(ETH_P_IP
),
191 .gc
= rt_garbage_collect
,
192 .check
= ipv4_dst_check
,
193 .default_advmss
= ipv4_default_advmss
,
194 .default_mtu
= ipv4_default_mtu
,
195 .cow_metrics
= ipv4_cow_metrics
,
196 .destroy
= ipv4_dst_destroy
,
197 .ifdown
= ipv4_dst_ifdown
,
198 .negative_advice
= ipv4_negative_advice
,
199 .link_failure
= ipv4_link_failure
,
200 .update_pmtu
= ip_rt_update_pmtu
,
201 .local_out
= __ip_local_out
,
204 #define ECN_OR_COST(class) TC_PRIO_##class
206 const __u8 ip_tos2prio
[16] = {
208 ECN_OR_COST(BESTEFFORT
),
210 ECN_OR_COST(BESTEFFORT
),
216 ECN_OR_COST(INTERACTIVE
),
218 ECN_OR_COST(INTERACTIVE
),
219 TC_PRIO_INTERACTIVE_BULK
,
220 ECN_OR_COST(INTERACTIVE_BULK
),
221 TC_PRIO_INTERACTIVE_BULK
,
222 ECN_OR_COST(INTERACTIVE_BULK
)
230 /* The locking scheme is rather straight forward:
232 * 1) Read-Copy Update protects the buckets of the central route hash.
233 * 2) Only writers remove entries, and they hold the lock
234 * as they look at rtable reference counts.
235 * 3) Only readers acquire references to rtable entries,
236 * they do so with atomic increments and with the
240 struct rt_hash_bucket
{
241 struct rtable __rcu
*chain
;
244 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
245 defined(CONFIG_PROVE_LOCKING)
247 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
248 * The size of this table is a power of two and depends on the number of CPUS.
249 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
251 #ifdef CONFIG_LOCKDEP
252 # define RT_HASH_LOCK_SZ 256
255 # define RT_HASH_LOCK_SZ 4096
257 # define RT_HASH_LOCK_SZ 2048
259 # define RT_HASH_LOCK_SZ 1024
261 # define RT_HASH_LOCK_SZ 512
263 # define RT_HASH_LOCK_SZ 256
267 static spinlock_t
*rt_hash_locks
;
268 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
270 static __init
void rt_hash_lock_init(void)
274 rt_hash_locks
= kmalloc(sizeof(spinlock_t
) * RT_HASH_LOCK_SZ
,
277 panic("IP: failed to allocate rt_hash_locks\n");
279 for (i
= 0; i
< RT_HASH_LOCK_SZ
; i
++)
280 spin_lock_init(&rt_hash_locks
[i
]);
283 # define rt_hash_lock_addr(slot) NULL
285 static inline void rt_hash_lock_init(void)
290 static struct rt_hash_bucket
*rt_hash_table __read_mostly
;
291 static unsigned rt_hash_mask __read_mostly
;
292 static unsigned int rt_hash_log __read_mostly
;
294 static DEFINE_PER_CPU(struct rt_cache_stat
, rt_cache_stat
);
295 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
297 static inline unsigned int rt_hash(__be32 daddr
, __be32 saddr
, int idx
,
300 return jhash_3words((__force u32
)daddr
, (__force u32
)saddr
,
305 static inline int rt_genid(struct net
*net
)
307 return atomic_read(&net
->ipv4
.rt_genid
);
310 #ifdef CONFIG_PROC_FS
311 struct rt_cache_iter_state
{
312 struct seq_net_private p
;
317 static struct rtable
*rt_cache_get_first(struct seq_file
*seq
)
319 struct rt_cache_iter_state
*st
= seq
->private;
320 struct rtable
*r
= NULL
;
322 for (st
->bucket
= rt_hash_mask
; st
->bucket
>= 0; --st
->bucket
) {
323 if (!rcu_dereference_raw(rt_hash_table
[st
->bucket
].chain
))
326 r
= rcu_dereference_bh(rt_hash_table
[st
->bucket
].chain
);
328 if (dev_net(r
->dst
.dev
) == seq_file_net(seq
) &&
329 r
->rt_genid
== st
->genid
)
331 r
= rcu_dereference_bh(r
->dst
.rt_next
);
333 rcu_read_unlock_bh();
338 static struct rtable
*__rt_cache_get_next(struct seq_file
*seq
,
341 struct rt_cache_iter_state
*st
= seq
->private;
343 r
= rcu_dereference_bh(r
->dst
.rt_next
);
345 rcu_read_unlock_bh();
347 if (--st
->bucket
< 0)
349 } while (!rcu_dereference_raw(rt_hash_table
[st
->bucket
].chain
));
351 r
= rcu_dereference_bh(rt_hash_table
[st
->bucket
].chain
);
356 static struct rtable
*rt_cache_get_next(struct seq_file
*seq
,
359 struct rt_cache_iter_state
*st
= seq
->private;
360 while ((r
= __rt_cache_get_next(seq
, r
)) != NULL
) {
361 if (dev_net(r
->dst
.dev
) != seq_file_net(seq
))
363 if (r
->rt_genid
== st
->genid
)
369 static struct rtable
*rt_cache_get_idx(struct seq_file
*seq
, loff_t pos
)
371 struct rtable
*r
= rt_cache_get_first(seq
);
374 while (pos
&& (r
= rt_cache_get_next(seq
, r
)))
376 return pos
? NULL
: r
;
379 static void *rt_cache_seq_start(struct seq_file
*seq
, loff_t
*pos
)
381 struct rt_cache_iter_state
*st
= seq
->private;
383 return rt_cache_get_idx(seq
, *pos
- 1);
384 st
->genid
= rt_genid(seq_file_net(seq
));
385 return SEQ_START_TOKEN
;
388 static void *rt_cache_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
392 if (v
== SEQ_START_TOKEN
)
393 r
= rt_cache_get_first(seq
);
395 r
= rt_cache_get_next(seq
, v
);
400 static void rt_cache_seq_stop(struct seq_file
*seq
, void *v
)
402 if (v
&& v
!= SEQ_START_TOKEN
)
403 rcu_read_unlock_bh();
406 static int rt_cache_seq_show(struct seq_file
*seq
, void *v
)
408 if (v
== SEQ_START_TOKEN
)
409 seq_printf(seq
, "%-127s\n",
410 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
411 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
414 struct rtable
*r
= v
;
417 seq_printf(seq
, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
418 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
419 r
->dst
.dev
? r
->dst
.dev
->name
: "*",
420 (__force u32
)r
->rt_dst
,
421 (__force u32
)r
->rt_gateway
,
422 r
->rt_flags
, atomic_read(&r
->dst
.__refcnt
),
423 r
->dst
.__use
, 0, (__force u32
)r
->rt_src
,
424 dst_metric_advmss(&r
->dst
) + 40,
425 dst_metric(&r
->dst
, RTAX_WINDOW
),
426 (int)((dst_metric(&r
->dst
, RTAX_RTT
) >> 3) +
427 dst_metric(&r
->dst
, RTAX_RTTVAR
)),
431 (r
->dst
.neighbour
->hh
.hh_output
==
432 dev_queue_xmit
) : 0),
433 r
->rt_spec_dst
, &len
);
435 seq_printf(seq
, "%*s\n", 127 - len
, "");
440 static const struct seq_operations rt_cache_seq_ops
= {
441 .start
= rt_cache_seq_start
,
442 .next
= rt_cache_seq_next
,
443 .stop
= rt_cache_seq_stop
,
444 .show
= rt_cache_seq_show
,
447 static int rt_cache_seq_open(struct inode
*inode
, struct file
*file
)
449 return seq_open_net(inode
, file
, &rt_cache_seq_ops
,
450 sizeof(struct rt_cache_iter_state
));
453 static const struct file_operations rt_cache_seq_fops
= {
454 .owner
= THIS_MODULE
,
455 .open
= rt_cache_seq_open
,
458 .release
= seq_release_net
,
462 static void *rt_cpu_seq_start(struct seq_file
*seq
, loff_t
*pos
)
467 return SEQ_START_TOKEN
;
469 for (cpu
= *pos
-1; cpu
< nr_cpu_ids
; ++cpu
) {
470 if (!cpu_possible(cpu
))
473 return &per_cpu(rt_cache_stat
, cpu
);
478 static void *rt_cpu_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
482 for (cpu
= *pos
; cpu
< nr_cpu_ids
; ++cpu
) {
483 if (!cpu_possible(cpu
))
486 return &per_cpu(rt_cache_stat
, cpu
);
492 static void rt_cpu_seq_stop(struct seq_file
*seq
, void *v
)
497 static int rt_cpu_seq_show(struct seq_file
*seq
, void *v
)
499 struct rt_cache_stat
*st
= v
;
501 if (v
== SEQ_START_TOKEN
) {
502 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");
506 seq_printf(seq
,"%08x %08x %08x %08x %08x %08x %08x %08x "
507 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
508 dst_entries_get_slow(&ipv4_dst_ops
),
531 static const struct seq_operations rt_cpu_seq_ops
= {
532 .start
= rt_cpu_seq_start
,
533 .next
= rt_cpu_seq_next
,
534 .stop
= rt_cpu_seq_stop
,
535 .show
= rt_cpu_seq_show
,
539 static int rt_cpu_seq_open(struct inode
*inode
, struct file
*file
)
541 return seq_open(file
, &rt_cpu_seq_ops
);
544 static const struct file_operations rt_cpu_seq_fops
= {
545 .owner
= THIS_MODULE
,
546 .open
= rt_cpu_seq_open
,
549 .release
= seq_release
,
552 #ifdef CONFIG_IP_ROUTE_CLASSID
553 static int rt_acct_proc_show(struct seq_file
*m
, void *v
)
555 struct ip_rt_acct
*dst
, *src
;
558 dst
= kcalloc(256, sizeof(struct ip_rt_acct
), GFP_KERNEL
);
562 for_each_possible_cpu(i
) {
563 src
= (struct ip_rt_acct
*)per_cpu_ptr(ip_rt_acct
, i
);
564 for (j
= 0; j
< 256; j
++) {
565 dst
[j
].o_bytes
+= src
[j
].o_bytes
;
566 dst
[j
].o_packets
+= src
[j
].o_packets
;
567 dst
[j
].i_bytes
+= src
[j
].i_bytes
;
568 dst
[j
].i_packets
+= src
[j
].i_packets
;
572 seq_write(m
, dst
, 256 * sizeof(struct ip_rt_acct
));
577 static int rt_acct_proc_open(struct inode
*inode
, struct file
*file
)
579 return single_open(file
, rt_acct_proc_show
, NULL
);
582 static const struct file_operations rt_acct_proc_fops
= {
583 .owner
= THIS_MODULE
,
584 .open
= rt_acct_proc_open
,
587 .release
= single_release
,
591 static int __net_init
ip_rt_do_proc_init(struct net
*net
)
593 struct proc_dir_entry
*pde
;
595 pde
= proc_net_fops_create(net
, "rt_cache", S_IRUGO
,
600 pde
= proc_create("rt_cache", S_IRUGO
,
601 net
->proc_net_stat
, &rt_cpu_seq_fops
);
605 #ifdef CONFIG_IP_ROUTE_CLASSID
606 pde
= proc_create("rt_acct", 0, net
->proc_net
, &rt_acct_proc_fops
);
612 #ifdef CONFIG_IP_ROUTE_CLASSID
614 remove_proc_entry("rt_cache", net
->proc_net_stat
);
617 remove_proc_entry("rt_cache", net
->proc_net
);
622 static void __net_exit
ip_rt_do_proc_exit(struct net
*net
)
624 remove_proc_entry("rt_cache", net
->proc_net_stat
);
625 remove_proc_entry("rt_cache", net
->proc_net
);
626 #ifdef CONFIG_IP_ROUTE_CLASSID
627 remove_proc_entry("rt_acct", net
->proc_net
);
631 static struct pernet_operations ip_rt_proc_ops __net_initdata
= {
632 .init
= ip_rt_do_proc_init
,
633 .exit
= ip_rt_do_proc_exit
,
636 static int __init
ip_rt_proc_init(void)
638 return register_pernet_subsys(&ip_rt_proc_ops
);
642 static inline int ip_rt_proc_init(void)
646 #endif /* CONFIG_PROC_FS */
648 static inline void rt_free(struct rtable
*rt
)
650 call_rcu_bh(&rt
->dst
.rcu_head
, dst_rcu_free
);
653 static inline void rt_drop(struct rtable
*rt
)
656 call_rcu_bh(&rt
->dst
.rcu_head
, dst_rcu_free
);
659 static inline int rt_fast_clean(struct rtable
*rth
)
661 /* Kill broadcast/multicast entries very aggresively, if they
662 collide in hash table with more useful entries */
663 return (rth
->rt_flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) &&
664 rt_is_input_route(rth
) && rth
->dst
.rt_next
;
667 static inline int rt_valuable(struct rtable
*rth
)
669 return (rth
->rt_flags
& (RTCF_REDIRECTED
| RTCF_NOTIFY
)) ||
670 (rth
->peer
&& rth
->peer
->pmtu_expires
);
673 static int rt_may_expire(struct rtable
*rth
, unsigned long tmo1
, unsigned long tmo2
)
678 if (atomic_read(&rth
->dst
.__refcnt
))
681 age
= jiffies
- rth
->dst
.lastuse
;
682 if ((age
<= tmo1
&& !rt_fast_clean(rth
)) ||
683 (age
<= tmo2
&& rt_valuable(rth
)))
689 /* Bits of score are:
691 * 30: not quite useless
692 * 29..0: usage counter
694 static inline u32
rt_score(struct rtable
*rt
)
696 u32 score
= jiffies
- rt
->dst
.lastuse
;
698 score
= ~score
& ~(3<<30);
703 if (rt_is_output_route(rt
) ||
704 !(rt
->rt_flags
& (RTCF_BROADCAST
|RTCF_MULTICAST
|RTCF_LOCAL
)))
710 static inline bool rt_caching(const struct net
*net
)
712 return net
->ipv4
.current_rt_cache_rebuild_count
<=
713 net
->ipv4
.sysctl_rt_cache_rebuild_count
;
716 static inline bool compare_hash_inputs(const struct rtable
*rt1
,
717 const struct rtable
*rt2
)
719 return ((((__force u32
)rt1
->rt_key_dst
^ (__force u32
)rt2
->rt_key_dst
) |
720 ((__force u32
)rt1
->rt_key_src
^ (__force u32
)rt2
->rt_key_src
) |
721 (rt1
->rt_iif
^ rt2
->rt_iif
)) == 0);
724 static inline int compare_keys(struct rtable
*rt1
, struct rtable
*rt2
)
726 return (((__force u32
)rt1
->rt_key_dst
^ (__force u32
)rt2
->rt_key_dst
) |
727 ((__force u32
)rt1
->rt_key_src
^ (__force u32
)rt2
->rt_key_src
) |
728 (rt1
->rt_mark
^ rt2
->rt_mark
) |
729 (rt1
->rt_key_tos
^ rt2
->rt_key_tos
) |
730 (rt1
->rt_oif
^ rt2
->rt_oif
) |
731 (rt1
->rt_iif
^ rt2
->rt_iif
)) == 0;
734 static inline int compare_netns(struct rtable
*rt1
, struct rtable
*rt2
)
736 return net_eq(dev_net(rt1
->dst
.dev
), dev_net(rt2
->dst
.dev
));
739 static inline int rt_is_expired(struct rtable
*rth
)
741 return rth
->rt_genid
!= rt_genid(dev_net(rth
->dst
.dev
));
745 * Perform a full scan of hash table and free all entries.
746 * Can be called by a softirq or a process.
747 * In the later case, we want to be reschedule if necessary
749 static void rt_do_flush(struct net
*net
, int process_context
)
752 struct rtable
*rth
, *next
;
754 for (i
= 0; i
<= rt_hash_mask
; i
++) {
755 struct rtable __rcu
**pprev
;
758 if (process_context
&& need_resched())
760 rth
= rcu_dereference_raw(rt_hash_table
[i
].chain
);
764 spin_lock_bh(rt_hash_lock_addr(i
));
767 pprev
= &rt_hash_table
[i
].chain
;
768 rth
= rcu_dereference_protected(*pprev
,
769 lockdep_is_held(rt_hash_lock_addr(i
)));
772 next
= rcu_dereference_protected(rth
->dst
.rt_next
,
773 lockdep_is_held(rt_hash_lock_addr(i
)));
776 net_eq(dev_net(rth
->dst
.dev
), net
)) {
777 rcu_assign_pointer(*pprev
, next
);
778 rcu_assign_pointer(rth
->dst
.rt_next
, list
);
781 pprev
= &rth
->dst
.rt_next
;
786 spin_unlock_bh(rt_hash_lock_addr(i
));
788 for (; list
; list
= next
) {
789 next
= rcu_dereference_protected(list
->dst
.rt_next
, 1);
796 * While freeing expired entries, we compute average chain length
797 * and standard deviation, using fixed-point arithmetic.
798 * This to have an estimation of rt_chain_length_max
799 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
800 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
804 #define ONE (1UL << FRACT_BITS)
807 * Given a hash chain and an item in this hash chain,
808 * find if a previous entry has the same hash_inputs
809 * (but differs on tos, mark or oif)
810 * Returns 0 if an alias is found.
811 * Returns ONE if rth has no alias before itself.
813 static int has_noalias(const struct rtable
*head
, const struct rtable
*rth
)
815 const struct rtable
*aux
= head
;
818 if (compare_hash_inputs(aux
, rth
))
820 aux
= rcu_dereference_protected(aux
->dst
.rt_next
, 1);
826 * Perturbation of rt_genid by a small quantity [1..256]
827 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
828 * many times (2^24) without giving recent rt_genid.
829 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
831 static void rt_cache_invalidate(struct net
*net
)
833 unsigned char shuffle
;
835 get_random_bytes(&shuffle
, sizeof(shuffle
));
836 atomic_add(shuffle
+ 1U, &net
->ipv4
.rt_genid
);
840 * delay < 0 : invalidate cache (fast : entries will be deleted later)
841 * delay >= 0 : invalidate & flush cache (can be long)
843 void rt_cache_flush(struct net
*net
, int delay
)
845 rt_cache_invalidate(net
);
847 rt_do_flush(net
, !in_softirq());
850 /* Flush previous cache invalidated entries from the cache */
851 void rt_cache_flush_batch(struct net
*net
)
853 rt_do_flush(net
, !in_softirq());
856 static void rt_emergency_hash_rebuild(struct net
*net
)
859 printk(KERN_WARNING
"Route hash chain too long!\n");
860 rt_cache_invalidate(net
);
864 Short description of GC goals.
866 We want to build algorithm, which will keep routing cache
867 at some equilibrium point, when number of aged off entries
868 is kept approximately equal to newly generated ones.
870 Current expiration strength is variable "expire".
871 We try to adjust it dynamically, so that if networking
872 is idle expires is large enough to keep enough of warm entries,
873 and when load increases it reduces to limit cache size.
876 static int rt_garbage_collect(struct dst_ops
*ops
)
878 static unsigned long expire
= RT_GC_TIMEOUT
;
879 static unsigned long last_gc
;
881 static int equilibrium
;
883 struct rtable __rcu
**rthp
;
884 unsigned long now
= jiffies
;
886 int entries
= dst_entries_get_fast(&ipv4_dst_ops
);
889 * Garbage collection is pretty expensive,
890 * do not make it too frequently.
893 RT_CACHE_STAT_INC(gc_total
);
895 if (now
- last_gc
< ip_rt_gc_min_interval
&&
896 entries
< ip_rt_max_size
) {
897 RT_CACHE_STAT_INC(gc_ignored
);
901 entries
= dst_entries_get_slow(&ipv4_dst_ops
);
902 /* Calculate number of entries, which we want to expire now. */
903 goal
= entries
- (ip_rt_gc_elasticity
<< rt_hash_log
);
905 if (equilibrium
< ipv4_dst_ops
.gc_thresh
)
906 equilibrium
= ipv4_dst_ops
.gc_thresh
;
907 goal
= entries
- equilibrium
;
909 equilibrium
+= min_t(unsigned int, goal
>> 1, rt_hash_mask
+ 1);
910 goal
= entries
- equilibrium
;
913 /* We are in dangerous area. Try to reduce cache really
916 goal
= max_t(unsigned int, goal
>> 1, rt_hash_mask
+ 1);
917 equilibrium
= entries
- goal
;
920 if (now
- last_gc
>= ip_rt_gc_min_interval
)
931 for (i
= rt_hash_mask
, k
= rover
; i
>= 0; i
--) {
932 unsigned long tmo
= expire
;
934 k
= (k
+ 1) & rt_hash_mask
;
935 rthp
= &rt_hash_table
[k
].chain
;
936 spin_lock_bh(rt_hash_lock_addr(k
));
937 while ((rth
= rcu_dereference_protected(*rthp
,
938 lockdep_is_held(rt_hash_lock_addr(k
)))) != NULL
) {
939 if (!rt_is_expired(rth
) &&
940 !rt_may_expire(rth
, tmo
, expire
)) {
942 rthp
= &rth
->dst
.rt_next
;
945 *rthp
= rth
->dst
.rt_next
;
949 spin_unlock_bh(rt_hash_lock_addr(k
));
958 /* Goal is not achieved. We stop process if:
960 - if expire reduced to zero. Otherwise, expire is halfed.
961 - if table is not full.
962 - if we are called from interrupt.
963 - jiffies check is just fallback/debug loop breaker.
964 We will not spin here for long time in any case.
967 RT_CACHE_STAT_INC(gc_goal_miss
);
974 if (dst_entries_get_fast(&ipv4_dst_ops
) < ip_rt_max_size
)
976 } while (!in_softirq() && time_before_eq(jiffies
, now
));
978 if (dst_entries_get_fast(&ipv4_dst_ops
) < ip_rt_max_size
)
980 if (dst_entries_get_slow(&ipv4_dst_ops
) < ip_rt_max_size
)
983 printk(KERN_WARNING
"dst cache overflow\n");
984 RT_CACHE_STAT_INC(gc_dst_overflow
);
988 expire
+= ip_rt_gc_min_interval
;
989 if (expire
> ip_rt_gc_timeout
||
990 dst_entries_get_fast(&ipv4_dst_ops
) < ipv4_dst_ops
.gc_thresh
||
991 dst_entries_get_slow(&ipv4_dst_ops
) < ipv4_dst_ops
.gc_thresh
)
992 expire
= ip_rt_gc_timeout
;
997 * Returns number of entries in a hash chain that have different hash_inputs
999 static int slow_chain_length(const struct rtable
*head
)
1002 const struct rtable
*rth
= head
;
1005 length
+= has_noalias(head
, rth
);
1006 rth
= rcu_dereference_protected(rth
->dst
.rt_next
, 1);
1008 return length
>> FRACT_BITS
;
1011 static int rt_bind_neighbour(struct rtable
*rt
)
1013 static const __be32 inaddr_any
= 0;
1014 struct net_device
*dev
= rt
->dst
.dev
;
1015 struct neigh_table
*tbl
= &arp_tbl
;
1016 const __be32
*nexthop
;
1017 struct neighbour
*n
;
1019 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
1020 if (dev
->type
== ARPHRD_ATM
)
1021 tbl
= clip_tbl_hook
;
1023 nexthop
= &rt
->rt_gateway
;
1024 if (dev
->flags
& (IFF_LOOPBACK
| IFF_POINTOPOINT
))
1025 nexthop
= &inaddr_any
;
1026 n
= ipv4_neigh_lookup(tbl
, dev
, nexthop
);
1029 rt
->dst
.neighbour
= n
;
1034 static struct rtable
*rt_intern_hash(unsigned hash
, struct rtable
*rt
,
1035 struct sk_buff
*skb
, int ifindex
)
1037 struct rtable
*rth
, *cand
;
1038 struct rtable __rcu
**rthp
, **candp
;
1042 int attempts
= !in_softirq();
1046 min_score
= ~(u32
)0;
1051 if (!rt_caching(dev_net(rt
->dst
.dev
))) {
1053 * If we're not caching, just tell the caller we
1054 * were successful and don't touch the route. The
1055 * caller hold the sole reference to the cache entry, and
1056 * it will be released when the caller is done with it.
1057 * If we drop it here, the callers have no way to resolve routes
1058 * when we're not caching. Instead, just point *rp at rt, so
1059 * the caller gets a single use out of the route
1060 * Note that we do rt_free on this new route entry, so that
1061 * once its refcount hits zero, we are still able to reap it
1063 * Note: To avoid expensive rcu stuff for this uncached dst,
1064 * we set DST_NOCACHE so that dst_release() can free dst without
1065 * waiting a grace period.
1068 rt
->dst
.flags
|= DST_NOCACHE
;
1069 if (rt
->rt_type
== RTN_UNICAST
|| rt_is_output_route(rt
)) {
1070 int err
= rt_bind_neighbour(rt
);
1072 if (net_ratelimit())
1074 "Neighbour table failure & not caching routes.\n");
1076 return ERR_PTR(err
);
1083 rthp
= &rt_hash_table
[hash
].chain
;
1085 spin_lock_bh(rt_hash_lock_addr(hash
));
1086 while ((rth
= rcu_dereference_protected(*rthp
,
1087 lockdep_is_held(rt_hash_lock_addr(hash
)))) != NULL
) {
1088 if (rt_is_expired(rth
)) {
1089 *rthp
= rth
->dst
.rt_next
;
1093 if (compare_keys(rth
, rt
) && compare_netns(rth
, rt
)) {
1095 *rthp
= rth
->dst
.rt_next
;
1097 * Since lookup is lockfree, the deletion
1098 * must be visible to another weakly ordered CPU before
1099 * the insertion at the start of the hash chain.
1101 rcu_assign_pointer(rth
->dst
.rt_next
,
1102 rt_hash_table
[hash
].chain
);
1104 * Since lookup is lockfree, the update writes
1105 * must be ordered for consistency on SMP.
1107 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rth
);
1109 dst_use(&rth
->dst
, now
);
1110 spin_unlock_bh(rt_hash_lock_addr(hash
));
1114 skb_dst_set(skb
, &rth
->dst
);
1118 if (!atomic_read(&rth
->dst
.__refcnt
)) {
1119 u32 score
= rt_score(rth
);
1121 if (score
<= min_score
) {
1130 rthp
= &rth
->dst
.rt_next
;
1134 /* ip_rt_gc_elasticity used to be average length of chain
1135 * length, when exceeded gc becomes really aggressive.
1137 * The second limit is less certain. At the moment it allows
1138 * only 2 entries per bucket. We will see.
1140 if (chain_length
> ip_rt_gc_elasticity
) {
1141 *candp
= cand
->dst
.rt_next
;
1145 if (chain_length
> rt_chain_length_max
&&
1146 slow_chain_length(rt_hash_table
[hash
].chain
) > rt_chain_length_max
) {
1147 struct net
*net
= dev_net(rt
->dst
.dev
);
1148 int num
= ++net
->ipv4
.current_rt_cache_rebuild_count
;
1149 if (!rt_caching(net
)) {
1150 printk(KERN_WARNING
"%s: %d rebuilds is over limit, route caching disabled\n",
1151 rt
->dst
.dev
->name
, num
);
1153 rt_emergency_hash_rebuild(net
);
1154 spin_unlock_bh(rt_hash_lock_addr(hash
));
1156 hash
= rt_hash(rt
->rt_key_dst
, rt
->rt_key_src
,
1157 ifindex
, rt_genid(net
));
1162 /* Try to bind route to arp only if it is output
1163 route or unicast forwarding path.
1165 if (rt
->rt_type
== RTN_UNICAST
|| rt_is_output_route(rt
)) {
1166 int err
= rt_bind_neighbour(rt
);
1168 spin_unlock_bh(rt_hash_lock_addr(hash
));
1170 if (err
!= -ENOBUFS
) {
1172 return ERR_PTR(err
);
1175 /* Neighbour tables are full and nothing
1176 can be released. Try to shrink route cache,
1177 it is most likely it holds some neighbour records.
1179 if (attempts
-- > 0) {
1180 int saved_elasticity
= ip_rt_gc_elasticity
;
1181 int saved_int
= ip_rt_gc_min_interval
;
1182 ip_rt_gc_elasticity
= 1;
1183 ip_rt_gc_min_interval
= 0;
1184 rt_garbage_collect(&ipv4_dst_ops
);
1185 ip_rt_gc_min_interval
= saved_int
;
1186 ip_rt_gc_elasticity
= saved_elasticity
;
1190 if (net_ratelimit())
1191 printk(KERN_WARNING
"ipv4: Neighbour table overflow.\n");
1193 return ERR_PTR(-ENOBUFS
);
1197 rt
->dst
.rt_next
= rt_hash_table
[hash
].chain
;
1200 * Since lookup is lockfree, we must make sure
1201 * previous writes to rt are committed to memory
1202 * before making rt visible to other CPUS.
1204 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rt
);
1206 spin_unlock_bh(rt_hash_lock_addr(hash
));
1210 skb_dst_set(skb
, &rt
->dst
);
1214 static atomic_t __rt_peer_genid
= ATOMIC_INIT(0);
1216 static u32
rt_peer_genid(void)
1218 return atomic_read(&__rt_peer_genid
);
1221 void rt_bind_peer(struct rtable
*rt
, __be32 daddr
, int create
)
1223 struct inet_peer
*peer
;
1225 peer
= inet_getpeer_v4(daddr
, create
);
1227 if (peer
&& cmpxchg(&rt
->peer
, NULL
, peer
) != NULL
)
1230 rt
->rt_peer_genid
= rt_peer_genid();
1234 * Peer allocation may fail only in serious out-of-memory conditions. However
1235 * we still can generate some output.
1236 * Random ID selection looks a bit dangerous because we have no chances to
1237 * select ID being unique in a reasonable period of time.
1238 * But broken packet identifier may be better than no packet at all.
1240 static void ip_select_fb_ident(struct iphdr
*iph
)
1242 static DEFINE_SPINLOCK(ip_fb_id_lock
);
1243 static u32 ip_fallback_id
;
1246 spin_lock_bh(&ip_fb_id_lock
);
1247 salt
= secure_ip_id((__force __be32
)ip_fallback_id
^ iph
->daddr
);
1248 iph
->id
= htons(salt
& 0xFFFF);
1249 ip_fallback_id
= salt
;
1250 spin_unlock_bh(&ip_fb_id_lock
);
1253 void __ip_select_ident(struct iphdr
*iph
, struct dst_entry
*dst
, int more
)
1255 struct rtable
*rt
= (struct rtable
*) dst
;
1258 if (rt
->peer
== NULL
)
1259 rt_bind_peer(rt
, rt
->rt_dst
, 1);
1261 /* If peer is attached to destination, it is never detached,
1262 so that we need not to grab a lock to dereference it.
1265 iph
->id
= htons(inet_getid(rt
->peer
, more
));
1269 printk(KERN_DEBUG
"rt_bind_peer(0) @%p\n",
1270 __builtin_return_address(0));
1272 ip_select_fb_ident(iph
);
1274 EXPORT_SYMBOL(__ip_select_ident
);
1276 static void rt_del(unsigned hash
, struct rtable
*rt
)
1278 struct rtable __rcu
**rthp
;
1281 rthp
= &rt_hash_table
[hash
].chain
;
1282 spin_lock_bh(rt_hash_lock_addr(hash
));
1284 while ((aux
= rcu_dereference_protected(*rthp
,
1285 lockdep_is_held(rt_hash_lock_addr(hash
)))) != NULL
) {
1286 if (aux
== rt
|| rt_is_expired(aux
)) {
1287 *rthp
= aux
->dst
.rt_next
;
1291 rthp
= &aux
->dst
.rt_next
;
1293 spin_unlock_bh(rt_hash_lock_addr(hash
));
1296 /* called in rcu_read_lock() section */
1297 void ip_rt_redirect(__be32 old_gw
, __be32 daddr
, __be32 new_gw
,
1298 __be32 saddr
, struct net_device
*dev
)
1300 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
1301 struct inet_peer
*peer
;
1308 if (new_gw
== old_gw
|| !IN_DEV_RX_REDIRECTS(in_dev
) ||
1309 ipv4_is_multicast(new_gw
) || ipv4_is_lbcast(new_gw
) ||
1310 ipv4_is_zeronet(new_gw
))
1311 goto reject_redirect
;
1313 if (!IN_DEV_SHARED_MEDIA(in_dev
)) {
1314 if (!inet_addr_onlink(in_dev
, new_gw
, old_gw
))
1315 goto reject_redirect
;
1316 if (IN_DEV_SEC_REDIRECTS(in_dev
) && ip_fib_check_default(new_gw
, dev
))
1317 goto reject_redirect
;
1319 if (inet_addr_type(net
, new_gw
) != RTN_UNICAST
)
1320 goto reject_redirect
;
1323 peer
= inet_getpeer_v4(daddr
, 1);
1325 peer
->redirect_learned
.a4
= new_gw
;
1329 atomic_inc(&__rt_peer_genid
);
1334 #ifdef CONFIG_IP_ROUTE_VERBOSE
1335 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit())
1336 printk(KERN_INFO
"Redirect from %pI4 on %s about %pI4 ignored.\n"
1337 " Advised path = %pI4 -> %pI4\n",
1338 &old_gw
, dev
->name
, &new_gw
,
1344 static bool peer_pmtu_expired(struct inet_peer
*peer
)
1346 unsigned long orig
= ACCESS_ONCE(peer
->pmtu_expires
);
1349 time_after_eq(jiffies
, orig
) &&
1350 cmpxchg(&peer
->pmtu_expires
, orig
, 0) == orig
;
1353 static bool peer_pmtu_cleaned(struct inet_peer
*peer
)
1355 unsigned long orig
= ACCESS_ONCE(peer
->pmtu_expires
);
1358 cmpxchg(&peer
->pmtu_expires
, orig
, 0) == orig
;
1361 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
)
1363 struct rtable
*rt
= (struct rtable
*)dst
;
1364 struct dst_entry
*ret
= dst
;
1367 if (dst
->obsolete
> 0) {
1370 } else if (rt
->rt_flags
& RTCF_REDIRECTED
) {
1371 unsigned hash
= rt_hash(rt
->rt_key_dst
, rt
->rt_key_src
,
1373 rt_genid(dev_net(dst
->dev
)));
1376 } else if (rt
->peer
&& peer_pmtu_expired(rt
->peer
)) {
1377 dst_metric_set(dst
, RTAX_MTU
, rt
->peer
->pmtu_orig
);
1385 * 1. The first ip_rt_redirect_number redirects are sent
1386 * with exponential backoff, then we stop sending them at all,
1387 * assuming that the host ignores our redirects.
1388 * 2. If we did not see packets requiring redirects
1389 * during ip_rt_redirect_silence, we assume that the host
1390 * forgot redirected route and start to send redirects again.
1392 * This algorithm is much cheaper and more intelligent than dumb load limiting
1395 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1396 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1399 void ip_rt_send_redirect(struct sk_buff
*skb
)
1401 struct rtable
*rt
= skb_rtable(skb
);
1402 struct in_device
*in_dev
;
1403 struct inet_peer
*peer
;
1407 in_dev
= __in_dev_get_rcu(rt
->dst
.dev
);
1408 if (!in_dev
|| !IN_DEV_TX_REDIRECTS(in_dev
)) {
1412 log_martians
= IN_DEV_LOG_MARTIANS(in_dev
);
1416 rt_bind_peer(rt
, rt
->rt_dst
, 1);
1419 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, rt
->rt_gateway
);
1423 /* No redirected packets during ip_rt_redirect_silence;
1424 * reset the algorithm.
1426 if (time_after(jiffies
, peer
->rate_last
+ ip_rt_redirect_silence
))
1427 peer
->rate_tokens
= 0;
1429 /* Too many ignored redirects; do not send anything
1430 * set dst.rate_last to the last seen redirected packet.
1432 if (peer
->rate_tokens
>= ip_rt_redirect_number
) {
1433 peer
->rate_last
= jiffies
;
1437 /* Check for load limit; set rate_last to the latest sent
1440 if (peer
->rate_tokens
== 0 ||
1443 (ip_rt_redirect_load
<< peer
->rate_tokens
)))) {
1444 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, rt
->rt_gateway
);
1445 peer
->rate_last
= jiffies
;
1446 ++peer
->rate_tokens
;
1447 #ifdef CONFIG_IP_ROUTE_VERBOSE
1449 peer
->rate_tokens
== ip_rt_redirect_number
&&
1451 printk(KERN_WARNING
"host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1452 &ip_hdr(skb
)->saddr
, rt
->rt_iif
,
1453 &rt
->rt_dst
, &rt
->rt_gateway
);
1458 static int ip_error(struct sk_buff
*skb
)
1460 struct rtable
*rt
= skb_rtable(skb
);
1461 struct inet_peer
*peer
;
1466 switch (rt
->dst
.error
) {
1471 code
= ICMP_HOST_UNREACH
;
1474 code
= ICMP_NET_UNREACH
;
1475 IP_INC_STATS_BH(dev_net(rt
->dst
.dev
),
1476 IPSTATS_MIB_INNOROUTES
);
1479 code
= ICMP_PKT_FILTERED
;
1484 rt_bind_peer(rt
, rt
->rt_dst
, 1);
1490 peer
->rate_tokens
+= now
- peer
->rate_last
;
1491 if (peer
->rate_tokens
> ip_rt_error_burst
)
1492 peer
->rate_tokens
= ip_rt_error_burst
;
1493 peer
->rate_last
= now
;
1494 if (peer
->rate_tokens
>= ip_rt_error_cost
)
1495 peer
->rate_tokens
-= ip_rt_error_cost
;
1500 icmp_send(skb
, ICMP_DEST_UNREACH
, code
, 0);
1502 out
: kfree_skb(skb
);
1507 * The last two values are not from the RFC but
1508 * are needed for AMPRnet AX.25 paths.
1511 static const unsigned short mtu_plateau
[] =
1512 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1514 static inline unsigned short guess_mtu(unsigned short old_mtu
)
1518 for (i
= 0; i
< ARRAY_SIZE(mtu_plateau
); i
++)
1519 if (old_mtu
> mtu_plateau
[i
])
1520 return mtu_plateau
[i
];
1524 unsigned short ip_rt_frag_needed(struct net
*net
, const struct iphdr
*iph
,
1525 unsigned short new_mtu
,
1526 struct net_device
*dev
)
1528 unsigned short old_mtu
= ntohs(iph
->tot_len
);
1529 unsigned short est_mtu
= 0;
1530 struct inet_peer
*peer
;
1532 peer
= inet_getpeer_v4(iph
->daddr
, 1);
1534 unsigned short mtu
= new_mtu
;
1536 if (new_mtu
< 68 || new_mtu
>= old_mtu
) {
1537 /* BSD 4.2 derived systems incorrectly adjust
1538 * tot_len by the IP header length, and report
1539 * a zero MTU in the ICMP message.
1542 old_mtu
>= 68 + (iph
->ihl
<< 2))
1543 old_mtu
-= iph
->ihl
<< 2;
1544 mtu
= guess_mtu(old_mtu
);
1547 if (mtu
< ip_rt_min_pmtu
)
1548 mtu
= ip_rt_min_pmtu
;
1549 if (!peer
->pmtu_expires
|| mtu
< peer
->pmtu_learned
) {
1550 unsigned long pmtu_expires
;
1552 pmtu_expires
= jiffies
+ ip_rt_mtu_expires
;
1557 peer
->pmtu_learned
= mtu
;
1558 peer
->pmtu_expires
= pmtu_expires
;
1563 atomic_inc(&__rt_peer_genid
);
1565 return est_mtu
? : new_mtu
;
1568 static void check_peer_pmtu(struct dst_entry
*dst
, struct inet_peer
*peer
)
1570 unsigned long expires
= ACCESS_ONCE(peer
->pmtu_expires
);
1574 if (time_before(jiffies
, expires
)) {
1575 u32 orig_dst_mtu
= dst_mtu(dst
);
1576 if (peer
->pmtu_learned
< orig_dst_mtu
) {
1577 if (!peer
->pmtu_orig
)
1578 peer
->pmtu_orig
= dst_metric_raw(dst
, RTAX_MTU
);
1579 dst_metric_set(dst
, RTAX_MTU
, peer
->pmtu_learned
);
1581 } else if (cmpxchg(&peer
->pmtu_expires
, expires
, 0) == expires
)
1582 dst_metric_set(dst
, RTAX_MTU
, peer
->pmtu_orig
);
1585 static void ip_rt_update_pmtu(struct dst_entry
*dst
, u32 mtu
)
1587 struct rtable
*rt
= (struct rtable
*) dst
;
1588 struct inet_peer
*peer
;
1593 rt_bind_peer(rt
, rt
->rt_dst
, 1);
1596 unsigned long pmtu_expires
= ACCESS_ONCE(peer
->pmtu_expires
);
1598 if (mtu
< ip_rt_min_pmtu
)
1599 mtu
= ip_rt_min_pmtu
;
1600 if (!pmtu_expires
|| mtu
< peer
->pmtu_learned
) {
1602 pmtu_expires
= jiffies
+ ip_rt_mtu_expires
;
1606 peer
->pmtu_learned
= mtu
;
1607 peer
->pmtu_expires
= pmtu_expires
;
1609 atomic_inc(&__rt_peer_genid
);
1610 rt
->rt_peer_genid
= rt_peer_genid();
1612 check_peer_pmtu(dst
, peer
);
1616 static int check_peer_redir(struct dst_entry
*dst
, struct inet_peer
*peer
)
1618 struct rtable
*rt
= (struct rtable
*) dst
;
1619 __be32 orig_gw
= rt
->rt_gateway
;
1621 dst_confirm(&rt
->dst
);
1623 neigh_release(rt
->dst
.neighbour
);
1624 rt
->dst
.neighbour
= NULL
;
1626 rt
->rt_gateway
= peer
->redirect_learned
.a4
;
1627 if (rt_bind_neighbour(rt
) ||
1628 !(rt
->dst
.neighbour
->nud_state
& NUD_VALID
)) {
1629 if (rt
->dst
.neighbour
)
1630 neigh_event_send(rt
->dst
.neighbour
, NULL
);
1631 rt
->rt_gateway
= orig_gw
;
1634 rt
->rt_flags
|= RTCF_REDIRECTED
;
1635 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE
,
1641 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
)
1643 struct rtable
*rt
= (struct rtable
*) dst
;
1645 if (rt_is_expired(rt
))
1647 if (rt
->rt_peer_genid
!= rt_peer_genid()) {
1648 struct inet_peer
*peer
;
1651 rt_bind_peer(rt
, rt
->rt_dst
, 0);
1655 check_peer_pmtu(dst
, peer
);
1657 if (peer
->redirect_learned
.a4
&&
1658 peer
->redirect_learned
.a4
!= rt
->rt_gateway
) {
1659 if (check_peer_redir(dst
, peer
))
1664 rt
->rt_peer_genid
= rt_peer_genid();
1669 static void ipv4_dst_destroy(struct dst_entry
*dst
)
1671 struct rtable
*rt
= (struct rtable
*) dst
;
1672 struct inet_peer
*peer
= rt
->peer
;
1675 fib_info_put(rt
->fi
);
1685 static void ipv4_link_failure(struct sk_buff
*skb
)
1689 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_HOST_UNREACH
, 0);
1691 rt
= skb_rtable(skb
);
1692 if (rt
&& rt
->peer
&& peer_pmtu_cleaned(rt
->peer
))
1693 dst_metric_set(&rt
->dst
, RTAX_MTU
, rt
->peer
->pmtu_orig
);
1696 static int ip_rt_bug(struct sk_buff
*skb
)
1698 printk(KERN_DEBUG
"ip_rt_bug: %pI4 -> %pI4, %s\n",
1699 &ip_hdr(skb
)->saddr
, &ip_hdr(skb
)->daddr
,
1700 skb
->dev
? skb
->dev
->name
: "?");
1707 We do not cache source address of outgoing interface,
1708 because it is used only by IP RR, TS and SRR options,
1709 so that it out of fast path.
1711 BTW remember: "addr" is allowed to be not aligned
1715 void ip_rt_get_source(u8
*addr
, struct sk_buff
*skb
, struct rtable
*rt
)
1719 if (rt_is_output_route(rt
))
1720 src
= ip_hdr(skb
)->saddr
;
1722 struct fib_result res
;
1728 memset(&fl4
, 0, sizeof(fl4
));
1729 fl4
.daddr
= iph
->daddr
;
1730 fl4
.saddr
= iph
->saddr
;
1731 fl4
.flowi4_tos
= iph
->tos
;
1732 fl4
.flowi4_oif
= rt
->dst
.dev
->ifindex
;
1733 fl4
.flowi4_iif
= skb
->dev
->ifindex
;
1734 fl4
.flowi4_mark
= skb
->mark
;
1737 if (fib_lookup(dev_net(rt
->dst
.dev
), &fl4
, &res
) == 0)
1738 src
= FIB_RES_PREFSRC(dev_net(rt
->dst
.dev
), res
);
1740 src
= inet_select_addr(rt
->dst
.dev
, rt
->rt_gateway
,
1744 memcpy(addr
, &src
, 4);
1747 #ifdef CONFIG_IP_ROUTE_CLASSID
1748 static void set_class_tag(struct rtable
*rt
, u32 tag
)
1750 if (!(rt
->dst
.tclassid
& 0xFFFF))
1751 rt
->dst
.tclassid
|= tag
& 0xFFFF;
1752 if (!(rt
->dst
.tclassid
& 0xFFFF0000))
1753 rt
->dst
.tclassid
|= tag
& 0xFFFF0000;
1757 static unsigned int ipv4_default_advmss(const struct dst_entry
*dst
)
1759 unsigned int advmss
= dst_metric_raw(dst
, RTAX_ADVMSS
);
1762 advmss
= max_t(unsigned int, dst
->dev
->mtu
- 40,
1764 if (advmss
> 65535 - 40)
1765 advmss
= 65535 - 40;
1770 static unsigned int ipv4_default_mtu(const struct dst_entry
*dst
)
1772 unsigned int mtu
= dst
->dev
->mtu
;
1774 if (unlikely(dst_metric_locked(dst
, RTAX_MTU
))) {
1775 const struct rtable
*rt
= (const struct rtable
*) dst
;
1777 if (rt
->rt_gateway
!= rt
->rt_dst
&& mtu
> 576)
1781 if (mtu
> IP_MAX_MTU
)
1787 static void rt_init_metrics(struct rtable
*rt
, const struct flowi4
*fl4
,
1788 struct fib_info
*fi
)
1790 struct inet_peer
*peer
;
1793 /* If a peer entry exists for this destination, we must hook
1794 * it up in order to get at cached metrics.
1796 if (fl4
&& (fl4
->flowi4_flags
& FLOWI_FLAG_PRECOW_METRICS
))
1799 rt
->peer
= peer
= inet_getpeer_v4(rt
->rt_dst
, create
);
1801 rt
->rt_peer_genid
= rt_peer_genid();
1802 if (inet_metrics_new(peer
))
1803 memcpy(peer
->metrics
, fi
->fib_metrics
,
1804 sizeof(u32
) * RTAX_MAX
);
1805 dst_init_metrics(&rt
->dst
, peer
->metrics
, false);
1807 check_peer_pmtu(&rt
->dst
, peer
);
1808 if (peer
->redirect_learned
.a4
&&
1809 peer
->redirect_learned
.a4
!= rt
->rt_gateway
) {
1810 rt
->rt_gateway
= peer
->redirect_learned
.a4
;
1811 rt
->rt_flags
|= RTCF_REDIRECTED
;
1814 if (fi
->fib_metrics
!= (u32
*) dst_default_metrics
) {
1816 atomic_inc(&fi
->fib_clntref
);
1818 dst_init_metrics(&rt
->dst
, fi
->fib_metrics
, true);
1822 static void rt_set_nexthop(struct rtable
*rt
, const struct flowi4
*fl4
,
1823 const struct fib_result
*res
,
1824 struct fib_info
*fi
, u16 type
, u32 itag
)
1826 struct dst_entry
*dst
= &rt
->dst
;
1829 if (FIB_RES_GW(*res
) &&
1830 FIB_RES_NH(*res
).nh_scope
== RT_SCOPE_LINK
)
1831 rt
->rt_gateway
= FIB_RES_GW(*res
);
1832 rt_init_metrics(rt
, fl4
, fi
);
1833 #ifdef CONFIG_IP_ROUTE_CLASSID
1834 dst
->tclassid
= FIB_RES_NH(*res
).nh_tclassid
;
1838 if (dst_mtu(dst
) > IP_MAX_MTU
)
1839 dst_metric_set(dst
, RTAX_MTU
, IP_MAX_MTU
);
1840 if (dst_metric_raw(dst
, RTAX_ADVMSS
) > 65535 - 40)
1841 dst_metric_set(dst
, RTAX_ADVMSS
, 65535 - 40);
1843 #ifdef CONFIG_IP_ROUTE_CLASSID
1844 #ifdef CONFIG_IP_MULTIPLE_TABLES
1845 set_class_tag(rt
, fib_rules_tclass(res
));
1847 set_class_tag(rt
, itag
);
1851 static struct rtable
*rt_dst_alloc(struct net_device
*dev
,
1852 bool nopolicy
, bool noxfrm
)
1854 return dst_alloc(&ipv4_dst_ops
, dev
, 1, -1,
1856 (nopolicy
? DST_NOPOLICY
: 0) |
1857 (noxfrm
? DST_NOXFRM
: 0));
1860 /* called in rcu_read_lock() section */
1861 static int ip_route_input_mc(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
1862 u8 tos
, struct net_device
*dev
, int our
)
1867 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
1871 /* Primary sanity checks. */
1876 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
) ||
1877 ipv4_is_loopback(saddr
) || skb
->protocol
!= htons(ETH_P_IP
))
1880 if (ipv4_is_zeronet(saddr
)) {
1881 if (!ipv4_is_local_multicast(daddr
))
1883 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_LINK
);
1885 err
= fib_validate_source(skb
, saddr
, 0, tos
, 0, dev
, &spec_dst
,
1890 rth
= rt_dst_alloc(init_net
.loopback_dev
,
1891 IN_DEV_CONF_GET(in_dev
, NOPOLICY
), false);
1895 #ifdef CONFIG_IP_ROUTE_CLASSID
1896 rth
->dst
.tclassid
= itag
;
1898 rth
->dst
.output
= ip_rt_bug
;
1900 rth
->rt_key_dst
= daddr
;
1901 rth
->rt_key_src
= saddr
;
1902 rth
->rt_genid
= rt_genid(dev_net(dev
));
1903 rth
->rt_flags
= RTCF_MULTICAST
;
1904 rth
->rt_type
= RTN_MULTICAST
;
1905 rth
->rt_key_tos
= tos
;
1906 rth
->rt_dst
= daddr
;
1907 rth
->rt_src
= saddr
;
1908 rth
->rt_route_iif
= dev
->ifindex
;
1909 rth
->rt_iif
= dev
->ifindex
;
1911 rth
->rt_mark
= skb
->mark
;
1912 rth
->rt_gateway
= daddr
;
1913 rth
->rt_spec_dst
= spec_dst
;
1914 rth
->rt_peer_genid
= 0;
1918 rth
->dst
.input
= ip_local_deliver
;
1919 rth
->rt_flags
|= RTCF_LOCAL
;
1922 #ifdef CONFIG_IP_MROUTE
1923 if (!ipv4_is_local_multicast(daddr
) && IN_DEV_MFORWARD(in_dev
))
1924 rth
->dst
.input
= ip_mr_input
;
1926 RT_CACHE_STAT_INC(in_slow_mc
);
1928 hash
= rt_hash(daddr
, saddr
, dev
->ifindex
, rt_genid(dev_net(dev
)));
1929 rth
= rt_intern_hash(hash
, rth
, skb
, dev
->ifindex
);
1930 return IS_ERR(rth
) ? PTR_ERR(rth
) : 0;
1941 static void ip_handle_martian_source(struct net_device
*dev
,
1942 struct in_device
*in_dev
,
1943 struct sk_buff
*skb
,
1947 RT_CACHE_STAT_INC(in_martian_src
);
1948 #ifdef CONFIG_IP_ROUTE_VERBOSE
1949 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit()) {
1951 * RFC1812 recommendation, if source is martian,
1952 * the only hint is MAC header.
1954 printk(KERN_WARNING
"martian source %pI4 from %pI4, on dev %s\n",
1955 &daddr
, &saddr
, dev
->name
);
1956 if (dev
->hard_header_len
&& skb_mac_header_was_set(skb
)) {
1958 const unsigned char *p
= skb_mac_header(skb
);
1959 printk(KERN_WARNING
"ll header: ");
1960 for (i
= 0; i
< dev
->hard_header_len
; i
++, p
++) {
1962 if (i
< (dev
->hard_header_len
- 1))
1971 /* called in rcu_read_lock() section */
1972 static int __mkroute_input(struct sk_buff
*skb
,
1973 const struct fib_result
*res
,
1974 struct in_device
*in_dev
,
1975 __be32 daddr
, __be32 saddr
, u32 tos
,
1976 struct rtable
**result
)
1980 struct in_device
*out_dev
;
1981 unsigned int flags
= 0;
1985 /* get a working reference to the output device */
1986 out_dev
= __in_dev_get_rcu(FIB_RES_DEV(*res
));
1987 if (out_dev
== NULL
) {
1988 if (net_ratelimit())
1989 printk(KERN_CRIT
"Bug in ip_route_input" \
1990 "_slow(). Please, report\n");
1995 err
= fib_validate_source(skb
, saddr
, daddr
, tos
, FIB_RES_OIF(*res
),
1996 in_dev
->dev
, &spec_dst
, &itag
);
1998 ip_handle_martian_source(in_dev
->dev
, in_dev
, skb
, daddr
,
2005 flags
|= RTCF_DIRECTSRC
;
2007 if (out_dev
== in_dev
&& err
&&
2008 (IN_DEV_SHARED_MEDIA(out_dev
) ||
2009 inet_addr_onlink(out_dev
, saddr
, FIB_RES_GW(*res
))))
2010 flags
|= RTCF_DOREDIRECT
;
2012 if (skb
->protocol
!= htons(ETH_P_IP
)) {
2013 /* Not IP (i.e. ARP). Do not create route, if it is
2014 * invalid for proxy arp. DNAT routes are always valid.
2016 * Proxy arp feature have been extended to allow, ARP
2017 * replies back to the same interface, to support
2018 * Private VLAN switch technologies. See arp.c.
2020 if (out_dev
== in_dev
&&
2021 IN_DEV_PROXY_ARP_PVLAN(in_dev
) == 0) {
2027 rth
= rt_dst_alloc(out_dev
->dev
,
2028 IN_DEV_CONF_GET(in_dev
, NOPOLICY
),
2029 IN_DEV_CONF_GET(out_dev
, NOXFRM
));
2035 rth
->rt_key_dst
= daddr
;
2036 rth
->rt_key_src
= saddr
;
2037 rth
->rt_genid
= rt_genid(dev_net(rth
->dst
.dev
));
2038 rth
->rt_flags
= flags
;
2039 rth
->rt_type
= res
->type
;
2040 rth
->rt_key_tos
= tos
;
2041 rth
->rt_dst
= daddr
;
2042 rth
->rt_src
= saddr
;
2043 rth
->rt_route_iif
= in_dev
->dev
->ifindex
;
2044 rth
->rt_iif
= in_dev
->dev
->ifindex
;
2046 rth
->rt_mark
= skb
->mark
;
2047 rth
->rt_gateway
= daddr
;
2048 rth
->rt_spec_dst
= spec_dst
;
2049 rth
->rt_peer_genid
= 0;
2053 rth
->dst
.input
= ip_forward
;
2054 rth
->dst
.output
= ip_output
;
2056 rt_set_nexthop(rth
, NULL
, res
, res
->fi
, res
->type
, itag
);
2064 static int ip_mkroute_input(struct sk_buff
*skb
,
2065 struct fib_result
*res
,
2066 const struct flowi4
*fl4
,
2067 struct in_device
*in_dev
,
2068 __be32 daddr
, __be32 saddr
, u32 tos
)
2070 struct rtable
* rth
= NULL
;
2074 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2075 if (res
->fi
&& res
->fi
->fib_nhs
> 1)
2076 fib_select_multipath(res
);
2079 /* create a routing cache entry */
2080 err
= __mkroute_input(skb
, res
, in_dev
, daddr
, saddr
, tos
, &rth
);
2084 /* put it into the cache */
2085 hash
= rt_hash(daddr
, saddr
, fl4
->flowi4_iif
,
2086 rt_genid(dev_net(rth
->dst
.dev
)));
2087 rth
= rt_intern_hash(hash
, rth
, skb
, fl4
->flowi4_iif
);
2089 return PTR_ERR(rth
);
2094 * NOTE. We drop all the packets that has local source
2095 * addresses, because every properly looped back packet
2096 * must have correct destination already attached by output routine.
2098 * Such approach solves two big problems:
2099 * 1. Not simplex devices are handled properly.
2100 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2101 * called with rcu_read_lock()
2104 static int ip_route_input_slow(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2105 u8 tos
, struct net_device
*dev
)
2107 struct fib_result res
;
2108 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
2112 struct rtable
* rth
;
2116 struct net
* net
= dev_net(dev
);
2118 /* IP on this device is disabled. */
2123 /* Check for the most weird martians, which can be not detected
2127 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
) ||
2128 ipv4_is_loopback(saddr
))
2129 goto martian_source
;
2131 if (ipv4_is_lbcast(daddr
) || (saddr
== 0 && daddr
== 0))
2134 /* Accept zero addresses only to limited broadcast;
2135 * I even do not know to fix it or not. Waiting for complains :-)
2137 if (ipv4_is_zeronet(saddr
))
2138 goto martian_source
;
2140 if (ipv4_is_zeronet(daddr
) || ipv4_is_loopback(daddr
))
2141 goto martian_destination
;
2144 * Now we are ready to route packet.
2147 fl4
.flowi4_iif
= dev
->ifindex
;
2148 fl4
.flowi4_mark
= skb
->mark
;
2149 fl4
.flowi4_tos
= tos
;
2150 fl4
.flowi4_scope
= RT_SCOPE_UNIVERSE
;
2153 err
= fib_lookup(net
, &fl4
, &res
);
2155 if (!IN_DEV_FORWARD(in_dev
))
2160 RT_CACHE_STAT_INC(in_slow_tot
);
2162 if (res
.type
== RTN_BROADCAST
)
2165 if (res
.type
== RTN_LOCAL
) {
2166 err
= fib_validate_source(skb
, saddr
, daddr
, tos
,
2167 net
->loopback_dev
->ifindex
,
2168 dev
, &spec_dst
, &itag
);
2170 goto martian_source_keep_err
;
2172 flags
|= RTCF_DIRECTSRC
;
2177 if (!IN_DEV_FORWARD(in_dev
))
2179 if (res
.type
!= RTN_UNICAST
)
2180 goto martian_destination
;
2182 err
= ip_mkroute_input(skb
, &res
, &fl4
, in_dev
, daddr
, saddr
, tos
);
2186 if (skb
->protocol
!= htons(ETH_P_IP
))
2189 if (ipv4_is_zeronet(saddr
))
2190 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_LINK
);
2192 err
= fib_validate_source(skb
, saddr
, 0, tos
, 0, dev
, &spec_dst
,
2195 goto martian_source_keep_err
;
2197 flags
|= RTCF_DIRECTSRC
;
2199 flags
|= RTCF_BROADCAST
;
2200 res
.type
= RTN_BROADCAST
;
2201 RT_CACHE_STAT_INC(in_brd
);
2204 rth
= rt_dst_alloc(net
->loopback_dev
,
2205 IN_DEV_CONF_GET(in_dev
, NOPOLICY
), false);
2209 rth
->dst
.input
= ip_local_deliver
;
2210 rth
->dst
.output
= ip_rt_bug
;
2211 #ifdef CONFIG_IP_ROUTE_CLASSID
2212 rth
->dst
.tclassid
= itag
;
2215 rth
->rt_key_dst
= daddr
;
2216 rth
->rt_key_src
= saddr
;
2217 rth
->rt_genid
= rt_genid(net
);
2218 rth
->rt_flags
= flags
|RTCF_LOCAL
;
2219 rth
->rt_type
= res
.type
;
2220 rth
->rt_key_tos
= tos
;
2221 rth
->rt_dst
= daddr
;
2222 rth
->rt_src
= saddr
;
2223 #ifdef CONFIG_IP_ROUTE_CLASSID
2224 rth
->dst
.tclassid
= itag
;
2226 rth
->rt_route_iif
= dev
->ifindex
;
2227 rth
->rt_iif
= dev
->ifindex
;
2229 rth
->rt_mark
= skb
->mark
;
2230 rth
->rt_gateway
= daddr
;
2231 rth
->rt_spec_dst
= spec_dst
;
2232 rth
->rt_peer_genid
= 0;
2235 if (res
.type
== RTN_UNREACHABLE
) {
2236 rth
->dst
.input
= ip_error
;
2237 rth
->dst
.error
= -err
;
2238 rth
->rt_flags
&= ~RTCF_LOCAL
;
2240 hash
= rt_hash(daddr
, saddr
, fl4
.flowi4_iif
, rt_genid(net
));
2241 rth
= rt_intern_hash(hash
, rth
, skb
, fl4
.flowi4_iif
);
2248 RT_CACHE_STAT_INC(in_no_route
);
2249 spec_dst
= inet_select_addr(dev
, 0, RT_SCOPE_UNIVERSE
);
2250 res
.type
= RTN_UNREACHABLE
;
2256 * Do not cache martian addresses: they should be logged (RFC1812)
2258 martian_destination
:
2259 RT_CACHE_STAT_INC(in_martian_dst
);
2260 #ifdef CONFIG_IP_ROUTE_VERBOSE
2261 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit())
2262 printk(KERN_WARNING
"martian destination %pI4 from %pI4, dev %s\n",
2263 &daddr
, &saddr
, dev
->name
);
2267 err
= -EHOSTUNREACH
;
2280 martian_source_keep_err
:
2281 ip_handle_martian_source(dev
, in_dev
, skb
, daddr
, saddr
);
2285 int ip_route_input_common(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2286 u8 tos
, struct net_device
*dev
, bool noref
)
2288 struct rtable
* rth
;
2290 int iif
= dev
->ifindex
;
2298 if (!rt_caching(net
))
2301 tos
&= IPTOS_RT_MASK
;
2302 hash
= rt_hash(daddr
, saddr
, iif
, rt_genid(net
));
2304 for (rth
= rcu_dereference(rt_hash_table
[hash
].chain
); rth
;
2305 rth
= rcu_dereference(rth
->dst
.rt_next
)) {
2306 if ((((__force u32
)rth
->rt_key_dst
^ (__force u32
)daddr
) |
2307 ((__force u32
)rth
->rt_key_src
^ (__force u32
)saddr
) |
2308 (rth
->rt_iif
^ iif
) |
2310 (rth
->rt_key_tos
^ tos
)) == 0 &&
2311 rth
->rt_mark
== skb
->mark
&&
2312 net_eq(dev_net(rth
->dst
.dev
), net
) &&
2313 !rt_is_expired(rth
)) {
2315 dst_use_noref(&rth
->dst
, jiffies
);
2316 skb_dst_set_noref(skb
, &rth
->dst
);
2318 dst_use(&rth
->dst
, jiffies
);
2319 skb_dst_set(skb
, &rth
->dst
);
2321 RT_CACHE_STAT_INC(in_hit
);
2325 RT_CACHE_STAT_INC(in_hlist_search
);
2329 /* Multicast recognition logic is moved from route cache to here.
2330 The problem was that too many Ethernet cards have broken/missing
2331 hardware multicast filters :-( As result the host on multicasting
2332 network acquires a lot of useless route cache entries, sort of
2333 SDR messages from all the world. Now we try to get rid of them.
2334 Really, provided software IP multicast filter is organized
2335 reasonably (at least, hashed), it does not result in a slowdown
2336 comparing with route cache reject entries.
2337 Note, that multicast routers are not affected, because
2338 route cache entry is created eventually.
2340 if (ipv4_is_multicast(daddr
)) {
2341 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
2344 int our
= ip_check_mc_rcu(in_dev
, daddr
, saddr
,
2345 ip_hdr(skb
)->protocol
);
2347 #ifdef CONFIG_IP_MROUTE
2349 (!ipv4_is_local_multicast(daddr
) &&
2350 IN_DEV_MFORWARD(in_dev
))
2353 int res
= ip_route_input_mc(skb
, daddr
, saddr
,
2362 res
= ip_route_input_slow(skb
, daddr
, saddr
, tos
, dev
);
2366 EXPORT_SYMBOL(ip_route_input_common
);
2368 /* called with rcu_read_lock() */
2369 static struct rtable
*__mkroute_output(const struct fib_result
*res
,
2370 const struct flowi4
*fl4
,
2371 __be32 orig_daddr
, __be32 orig_saddr
,
2372 int orig_oif
, struct net_device
*dev_out
,
2375 struct fib_info
*fi
= res
->fi
;
2376 u32 tos
= RT_FL_TOS(fl4
);
2377 struct in_device
*in_dev
;
2378 u16 type
= res
->type
;
2381 if (ipv4_is_loopback(fl4
->saddr
) && !(dev_out
->flags
& IFF_LOOPBACK
))
2382 return ERR_PTR(-EINVAL
);
2384 if (ipv4_is_lbcast(fl4
->daddr
))
2385 type
= RTN_BROADCAST
;
2386 else if (ipv4_is_multicast(fl4
->daddr
))
2387 type
= RTN_MULTICAST
;
2388 else if (ipv4_is_zeronet(fl4
->daddr
))
2389 return ERR_PTR(-EINVAL
);
2391 if (dev_out
->flags
& IFF_LOOPBACK
)
2392 flags
|= RTCF_LOCAL
;
2394 in_dev
= __in_dev_get_rcu(dev_out
);
2396 return ERR_PTR(-EINVAL
);
2398 if (type
== RTN_BROADCAST
) {
2399 flags
|= RTCF_BROADCAST
| RTCF_LOCAL
;
2401 } else if (type
== RTN_MULTICAST
) {
2402 flags
|= RTCF_MULTICAST
| RTCF_LOCAL
;
2403 if (!ip_check_mc_rcu(in_dev
, fl4
->daddr
, fl4
->saddr
,
2405 flags
&= ~RTCF_LOCAL
;
2406 /* If multicast route do not exist use
2407 * default one, but do not gateway in this case.
2410 if (fi
&& res
->prefixlen
< 4)
2414 rth
= rt_dst_alloc(dev_out
,
2415 IN_DEV_CONF_GET(in_dev
, NOPOLICY
),
2416 IN_DEV_CONF_GET(in_dev
, NOXFRM
));
2418 return ERR_PTR(-ENOBUFS
);
2420 rth
->dst
.output
= ip_output
;
2422 rth
->rt_key_dst
= orig_daddr
;
2423 rth
->rt_key_src
= orig_saddr
;
2424 rth
->rt_genid
= rt_genid(dev_net(dev_out
));
2425 rth
->rt_flags
= flags
;
2426 rth
->rt_type
= type
;
2427 rth
->rt_key_tos
= tos
;
2428 rth
->rt_dst
= fl4
->daddr
;
2429 rth
->rt_src
= fl4
->saddr
;
2430 rth
->rt_route_iif
= 0;
2431 rth
->rt_iif
= orig_oif
? : dev_out
->ifindex
;
2432 rth
->rt_oif
= orig_oif
;
2433 rth
->rt_mark
= fl4
->flowi4_mark
;
2434 rth
->rt_gateway
= fl4
->daddr
;
2435 rth
->rt_spec_dst
= fl4
->saddr
;
2436 rth
->rt_peer_genid
= 0;
2440 RT_CACHE_STAT_INC(out_slow_tot
);
2442 if (flags
& RTCF_LOCAL
) {
2443 rth
->dst
.input
= ip_local_deliver
;
2444 rth
->rt_spec_dst
= fl4
->daddr
;
2446 if (flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) {
2447 rth
->rt_spec_dst
= fl4
->saddr
;
2448 if (flags
& RTCF_LOCAL
&&
2449 !(dev_out
->flags
& IFF_LOOPBACK
)) {
2450 rth
->dst
.output
= ip_mc_output
;
2451 RT_CACHE_STAT_INC(out_slow_mc
);
2453 #ifdef CONFIG_IP_MROUTE
2454 if (type
== RTN_MULTICAST
) {
2455 if (IN_DEV_MFORWARD(in_dev
) &&
2456 !ipv4_is_local_multicast(fl4
->daddr
)) {
2457 rth
->dst
.input
= ip_mr_input
;
2458 rth
->dst
.output
= ip_mc_output
;
2464 rt_set_nexthop(rth
, fl4
, res
, fi
, type
, 0);
2470 * Major route resolver routine.
2471 * called with rcu_read_lock();
2474 static struct rtable
*ip_route_output_slow(struct net
*net
, struct flowi4
*fl4
)
2476 struct net_device
*dev_out
= NULL
;
2477 u32 tos
= RT_FL_TOS(fl4
);
2478 unsigned int flags
= 0;
2479 struct fib_result res
;
2486 #ifdef CONFIG_IP_MULTIPLE_TABLES
2490 orig_daddr
= fl4
->daddr
;
2491 orig_saddr
= fl4
->saddr
;
2492 orig_oif
= fl4
->flowi4_oif
;
2494 fl4
->flowi4_iif
= net
->loopback_dev
->ifindex
;
2495 fl4
->flowi4_tos
= tos
& IPTOS_RT_MASK
;
2496 fl4
->flowi4_scope
= ((tos
& RTO_ONLINK
) ?
2497 RT_SCOPE_LINK
: RT_SCOPE_UNIVERSE
);
2501 rth
= ERR_PTR(-EINVAL
);
2502 if (ipv4_is_multicast(fl4
->saddr
) ||
2503 ipv4_is_lbcast(fl4
->saddr
) ||
2504 ipv4_is_zeronet(fl4
->saddr
))
2507 /* I removed check for oif == dev_out->oif here.
2508 It was wrong for two reasons:
2509 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2510 is assigned to multiple interfaces.
2511 2. Moreover, we are allowed to send packets with saddr
2512 of another iface. --ANK
2515 if (fl4
->flowi4_oif
== 0 &&
2516 (ipv4_is_multicast(fl4
->daddr
) ||
2517 ipv4_is_lbcast(fl4
->daddr
))) {
2518 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2519 dev_out
= __ip_dev_find(net
, fl4
->saddr
, false);
2520 if (dev_out
== NULL
)
2523 /* Special hack: user can direct multicasts
2524 and limited broadcast via necessary interface
2525 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2526 This hack is not just for fun, it allows
2527 vic,vat and friends to work.
2528 They bind socket to loopback, set ttl to zero
2529 and expect that it will work.
2530 From the viewpoint of routing cache they are broken,
2531 because we are not allowed to build multicast path
2532 with loopback source addr (look, routing cache
2533 cannot know, that ttl is zero, so that packet
2534 will not leave this host and route is valid).
2535 Luckily, this hack is good workaround.
2538 fl4
->flowi4_oif
= dev_out
->ifindex
;
2542 if (!(fl4
->flowi4_flags
& FLOWI_FLAG_ANYSRC
)) {
2543 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2544 if (!__ip_dev_find(net
, fl4
->saddr
, false))
2550 if (fl4
->flowi4_oif
) {
2551 dev_out
= dev_get_by_index_rcu(net
, fl4
->flowi4_oif
);
2552 rth
= ERR_PTR(-ENODEV
);
2553 if (dev_out
== NULL
)
2556 /* RACE: Check return value of inet_select_addr instead. */
2557 if (!(dev_out
->flags
& IFF_UP
) || !__in_dev_get_rcu(dev_out
)) {
2558 rth
= ERR_PTR(-ENETUNREACH
);
2561 if (ipv4_is_local_multicast(fl4
->daddr
) ||
2562 ipv4_is_lbcast(fl4
->daddr
)) {
2564 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2569 if (ipv4_is_multicast(fl4
->daddr
))
2570 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2572 else if (!fl4
->daddr
)
2573 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2579 fl4
->daddr
= fl4
->saddr
;
2581 fl4
->daddr
= fl4
->saddr
= htonl(INADDR_LOOPBACK
);
2582 dev_out
= net
->loopback_dev
;
2583 fl4
->flowi4_oif
= net
->loopback_dev
->ifindex
;
2584 res
.type
= RTN_LOCAL
;
2585 flags
|= RTCF_LOCAL
;
2589 if (fib_lookup(net
, fl4
, &res
)) {
2591 if (fl4
->flowi4_oif
) {
2592 /* Apparently, routing tables are wrong. Assume,
2593 that the destination is on link.
2596 Because we are allowed to send to iface
2597 even if it has NO routes and NO assigned
2598 addresses. When oif is specified, routing
2599 tables are looked up with only one purpose:
2600 to catch if destination is gatewayed, rather than
2601 direct. Moreover, if MSG_DONTROUTE is set,
2602 we send packet, ignoring both routing tables
2603 and ifaddr state. --ANK
2606 We could make it even if oif is unknown,
2607 likely IPv6, but we do not.
2610 if (fl4
->saddr
== 0)
2611 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2613 res
.type
= RTN_UNICAST
;
2616 rth
= ERR_PTR(-ENETUNREACH
);
2620 if (res
.type
== RTN_LOCAL
) {
2622 if (res
.fi
->fib_prefsrc
)
2623 fl4
->saddr
= res
.fi
->fib_prefsrc
;
2625 fl4
->saddr
= fl4
->daddr
;
2627 dev_out
= net
->loopback_dev
;
2628 fl4
->flowi4_oif
= dev_out
->ifindex
;
2630 flags
|= RTCF_LOCAL
;
2634 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2635 if (res
.fi
->fib_nhs
> 1 && fl4
->flowi4_oif
== 0)
2636 fib_select_multipath(&res
);
2639 if (!res
.prefixlen
&&
2640 res
.table
->tb_num_default
> 1 &&
2641 res
.type
== RTN_UNICAST
&& !fl4
->flowi4_oif
)
2642 fib_select_default(&res
);
2645 fl4
->saddr
= FIB_RES_PREFSRC(net
, res
);
2647 dev_out
= FIB_RES_DEV(res
);
2648 fl4
->flowi4_oif
= dev_out
->ifindex
;
2652 rth
= __mkroute_output(&res
, fl4
, orig_daddr
, orig_saddr
, orig_oif
,
2657 hash
= rt_hash(orig_daddr
, orig_saddr
, orig_oif
,
2658 rt_genid(dev_net(dev_out
)));
2659 rth
= rt_intern_hash(hash
, rth
, NULL
, orig_oif
);
2667 struct rtable
*__ip_route_output_key(struct net
*net
, struct flowi4
*flp4
)
2672 if (!rt_caching(net
))
2675 hash
= rt_hash(flp4
->daddr
, flp4
->saddr
, flp4
->flowi4_oif
, rt_genid(net
));
2678 for (rth
= rcu_dereference_bh(rt_hash_table
[hash
].chain
); rth
;
2679 rth
= rcu_dereference_bh(rth
->dst
.rt_next
)) {
2680 if (rth
->rt_key_dst
== flp4
->daddr
&&
2681 rth
->rt_key_src
== flp4
->saddr
&&
2682 rt_is_output_route(rth
) &&
2683 rth
->rt_oif
== flp4
->flowi4_oif
&&
2684 rth
->rt_mark
== flp4
->flowi4_mark
&&
2685 !((rth
->rt_key_tos
^ flp4
->flowi4_tos
) &
2686 (IPTOS_RT_MASK
| RTO_ONLINK
)) &&
2687 net_eq(dev_net(rth
->dst
.dev
), net
) &&
2688 !rt_is_expired(rth
)) {
2689 dst_use(&rth
->dst
, jiffies
);
2690 RT_CACHE_STAT_INC(out_hit
);
2691 rcu_read_unlock_bh();
2693 flp4
->saddr
= rth
->rt_src
;
2695 flp4
->daddr
= rth
->rt_dst
;
2698 RT_CACHE_STAT_INC(out_hlist_search
);
2700 rcu_read_unlock_bh();
2703 return ip_route_output_slow(net
, flp4
);
2705 EXPORT_SYMBOL_GPL(__ip_route_output_key
);
2707 static struct dst_entry
*ipv4_blackhole_dst_check(struct dst_entry
*dst
, u32 cookie
)
2712 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry
*dst
)
2717 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry
*dst
, u32 mtu
)
2721 static u32
*ipv4_rt_blackhole_cow_metrics(struct dst_entry
*dst
,
2727 static struct dst_ops ipv4_dst_blackhole_ops
= {
2729 .protocol
= cpu_to_be16(ETH_P_IP
),
2730 .destroy
= ipv4_dst_destroy
,
2731 .check
= ipv4_blackhole_dst_check
,
2732 .default_mtu
= ipv4_blackhole_default_mtu
,
2733 .default_advmss
= ipv4_default_advmss
,
2734 .update_pmtu
= ipv4_rt_blackhole_update_pmtu
,
2735 .cow_metrics
= ipv4_rt_blackhole_cow_metrics
,
2738 struct dst_entry
*ipv4_blackhole_route(struct net
*net
, struct dst_entry
*dst_orig
)
2740 struct rtable
*rt
= dst_alloc(&ipv4_dst_blackhole_ops
, NULL
, 1, 0, 0);
2741 struct rtable
*ort
= (struct rtable
*) dst_orig
;
2744 struct dst_entry
*new = &rt
->dst
;
2747 new->input
= dst_discard
;
2748 new->output
= dst_discard
;
2749 dst_copy_metrics(new, &ort
->dst
);
2751 new->dev
= ort
->dst
.dev
;
2755 rt
->rt_key_dst
= ort
->rt_key_dst
;
2756 rt
->rt_key_src
= ort
->rt_key_src
;
2757 rt
->rt_key_tos
= ort
->rt_key_tos
;
2758 rt
->rt_route_iif
= ort
->rt_route_iif
;
2759 rt
->rt_iif
= ort
->rt_iif
;
2760 rt
->rt_oif
= ort
->rt_oif
;
2761 rt
->rt_mark
= ort
->rt_mark
;
2763 rt
->rt_genid
= rt_genid(net
);
2764 rt
->rt_flags
= ort
->rt_flags
;
2765 rt
->rt_type
= ort
->rt_type
;
2766 rt
->rt_dst
= ort
->rt_dst
;
2767 rt
->rt_src
= ort
->rt_src
;
2768 rt
->rt_gateway
= ort
->rt_gateway
;
2769 rt
->rt_spec_dst
= ort
->rt_spec_dst
;
2770 rt
->peer
= ort
->peer
;
2772 atomic_inc(&rt
->peer
->refcnt
);
2775 atomic_inc(&rt
->fi
->fib_clntref
);
2780 dst_release(dst_orig
);
2782 return rt
? &rt
->dst
: ERR_PTR(-ENOMEM
);
2785 struct rtable
*ip_route_output_flow(struct net
*net
, struct flowi4
*flp4
,
2788 struct rtable
*rt
= __ip_route_output_key(net
, flp4
);
2793 if (flp4
->flowi4_proto
)
2794 rt
= (struct rtable
*) xfrm_lookup(net
, &rt
->dst
,
2795 flowi4_to_flowi(flp4
),
2800 EXPORT_SYMBOL_GPL(ip_route_output_flow
);
2802 static int rt_fill_info(struct net
*net
,
2803 struct sk_buff
*skb
, u32 pid
, u32 seq
, int event
,
2804 int nowait
, unsigned int flags
)
2806 struct rtable
*rt
= skb_rtable(skb
);
2808 struct nlmsghdr
*nlh
;
2810 const struct inet_peer
*peer
= rt
->peer
;
2811 u32 id
= 0, ts
= 0, tsage
= 0, error
;
2813 nlh
= nlmsg_put(skb
, pid
, seq
, event
, sizeof(*r
), flags
);
2817 r
= nlmsg_data(nlh
);
2818 r
->rtm_family
= AF_INET
;
2819 r
->rtm_dst_len
= 32;
2821 r
->rtm_tos
= rt
->rt_key_tos
;
2822 r
->rtm_table
= RT_TABLE_MAIN
;
2823 NLA_PUT_U32(skb
, RTA_TABLE
, RT_TABLE_MAIN
);
2824 r
->rtm_type
= rt
->rt_type
;
2825 r
->rtm_scope
= RT_SCOPE_UNIVERSE
;
2826 r
->rtm_protocol
= RTPROT_UNSPEC
;
2827 r
->rtm_flags
= (rt
->rt_flags
& ~0xFFFF) | RTM_F_CLONED
;
2828 if (rt
->rt_flags
& RTCF_NOTIFY
)
2829 r
->rtm_flags
|= RTM_F_NOTIFY
;
2831 NLA_PUT_BE32(skb
, RTA_DST
, rt
->rt_dst
);
2833 if (rt
->rt_key_src
) {
2834 r
->rtm_src_len
= 32;
2835 NLA_PUT_BE32(skb
, RTA_SRC
, rt
->rt_key_src
);
2838 NLA_PUT_U32(skb
, RTA_OIF
, rt
->dst
.dev
->ifindex
);
2839 #ifdef CONFIG_IP_ROUTE_CLASSID
2840 if (rt
->dst
.tclassid
)
2841 NLA_PUT_U32(skb
, RTA_FLOW
, rt
->dst
.tclassid
);
2843 if (rt_is_input_route(rt
))
2844 NLA_PUT_BE32(skb
, RTA_PREFSRC
, rt
->rt_spec_dst
);
2845 else if (rt
->rt_src
!= rt
->rt_key_src
)
2846 NLA_PUT_BE32(skb
, RTA_PREFSRC
, rt
->rt_src
);
2848 if (rt
->rt_dst
!= rt
->rt_gateway
)
2849 NLA_PUT_BE32(skb
, RTA_GATEWAY
, rt
->rt_gateway
);
2851 if (rtnetlink_put_metrics(skb
, dst_metrics_ptr(&rt
->dst
)) < 0)
2852 goto nla_put_failure
;
2855 NLA_PUT_BE32(skb
, RTA_MARK
, rt
->rt_mark
);
2857 error
= rt
->dst
.error
;
2859 inet_peer_refcheck(rt
->peer
);
2860 id
= atomic_read(&peer
->ip_id_count
) & 0xffff;
2861 if (peer
->tcp_ts_stamp
) {
2863 tsage
= get_seconds() - peer
->tcp_ts_stamp
;
2865 expires
= ACCESS_ONCE(peer
->pmtu_expires
);
2870 if (rt_is_input_route(rt
)) {
2871 #ifdef CONFIG_IP_MROUTE
2872 __be32 dst
= rt
->rt_dst
;
2874 if (ipv4_is_multicast(dst
) && !ipv4_is_local_multicast(dst
) &&
2875 IPV4_DEVCONF_ALL(net
, MC_FORWARDING
)) {
2876 int err
= ipmr_get_route(net
, skb
,
2877 rt
->rt_src
, rt
->rt_dst
,
2883 goto nla_put_failure
;
2885 if (err
== -EMSGSIZE
)
2886 goto nla_put_failure
;
2892 NLA_PUT_U32(skb
, RTA_IIF
, rt
->rt_iif
);
2895 if (rtnl_put_cacheinfo(skb
, &rt
->dst
, id
, ts
, tsage
,
2896 expires
, error
) < 0)
2897 goto nla_put_failure
;
2899 return nlmsg_end(skb
, nlh
);
2902 nlmsg_cancel(skb
, nlh
);
2906 static int inet_rtm_getroute(struct sk_buff
*in_skb
, struct nlmsghdr
* nlh
, void *arg
)
2908 struct net
*net
= sock_net(in_skb
->sk
);
2910 struct nlattr
*tb
[RTA_MAX
+1];
2911 struct rtable
*rt
= NULL
;
2917 struct sk_buff
*skb
;
2919 err
= nlmsg_parse(nlh
, sizeof(*rtm
), tb
, RTA_MAX
, rtm_ipv4_policy
);
2923 rtm
= nlmsg_data(nlh
);
2925 skb
= alloc_skb(NLMSG_GOODSIZE
, GFP_KERNEL
);
2931 /* Reserve room for dummy headers, this skb can pass
2932 through good chunk of routing engine.
2934 skb_reset_mac_header(skb
);
2935 skb_reset_network_header(skb
);
2937 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2938 ip_hdr(skb
)->protocol
= IPPROTO_ICMP
;
2939 skb_reserve(skb
, MAX_HEADER
+ sizeof(struct iphdr
));
2941 src
= tb
[RTA_SRC
] ? nla_get_be32(tb
[RTA_SRC
]) : 0;
2942 dst
= tb
[RTA_DST
] ? nla_get_be32(tb
[RTA_DST
]) : 0;
2943 iif
= tb
[RTA_IIF
] ? nla_get_u32(tb
[RTA_IIF
]) : 0;
2944 mark
= tb
[RTA_MARK
] ? nla_get_u32(tb
[RTA_MARK
]) : 0;
2947 struct net_device
*dev
;
2949 dev
= __dev_get_by_index(net
, iif
);
2955 skb
->protocol
= htons(ETH_P_IP
);
2959 err
= ip_route_input(skb
, dst
, src
, rtm
->rtm_tos
, dev
);
2962 rt
= skb_rtable(skb
);
2963 if (err
== 0 && rt
->dst
.error
)
2964 err
= -rt
->dst
.error
;
2966 struct flowi4 fl4
= {
2969 .flowi4_tos
= rtm
->rtm_tos
,
2970 .flowi4_oif
= tb
[RTA_OIF
] ? nla_get_u32(tb
[RTA_OIF
]) : 0,
2971 .flowi4_mark
= mark
,
2973 rt
= ip_route_output_key(net
, &fl4
);
2983 skb_dst_set(skb
, &rt
->dst
);
2984 if (rtm
->rtm_flags
& RTM_F_NOTIFY
)
2985 rt
->rt_flags
|= RTCF_NOTIFY
;
2987 err
= rt_fill_info(net
, skb
, NETLINK_CB(in_skb
).pid
, nlh
->nlmsg_seq
,
2988 RTM_NEWROUTE
, 0, 0);
2992 err
= rtnl_unicast(skb
, net
, NETLINK_CB(in_skb
).pid
);
3001 int ip_rt_dump(struct sk_buff
*skb
, struct netlink_callback
*cb
)
3008 net
= sock_net(skb
->sk
);
3013 s_idx
= idx
= cb
->args
[1];
3014 for (h
= s_h
; h
<= rt_hash_mask
; h
++, s_idx
= 0) {
3015 if (!rt_hash_table
[h
].chain
)
3018 for (rt
= rcu_dereference_bh(rt_hash_table
[h
].chain
), idx
= 0; rt
;
3019 rt
= rcu_dereference_bh(rt
->dst
.rt_next
), idx
++) {
3020 if (!net_eq(dev_net(rt
->dst
.dev
), net
) || idx
< s_idx
)
3022 if (rt_is_expired(rt
))
3024 skb_dst_set_noref(skb
, &rt
->dst
);
3025 if (rt_fill_info(net
, skb
, NETLINK_CB(cb
->skb
).pid
,
3026 cb
->nlh
->nlmsg_seq
, RTM_NEWROUTE
,
3027 1, NLM_F_MULTI
) <= 0) {
3029 rcu_read_unlock_bh();
3034 rcu_read_unlock_bh();
3043 void ip_rt_multicast_event(struct in_device
*in_dev
)
3045 rt_cache_flush(dev_net(in_dev
->dev
), 0);
3048 #ifdef CONFIG_SYSCTL
3049 static int ipv4_sysctl_rtcache_flush(ctl_table
*__ctl
, int write
,
3050 void __user
*buffer
,
3051 size_t *lenp
, loff_t
*ppos
)
3058 memcpy(&ctl
, __ctl
, sizeof(ctl
));
3059 ctl
.data
= &flush_delay
;
3060 proc_dointvec(&ctl
, write
, buffer
, lenp
, ppos
);
3062 net
= (struct net
*)__ctl
->extra1
;
3063 rt_cache_flush(net
, flush_delay
);
3070 static ctl_table ipv4_route_table
[] = {
3072 .procname
= "gc_thresh",
3073 .data
= &ipv4_dst_ops
.gc_thresh
,
3074 .maxlen
= sizeof(int),
3076 .proc_handler
= proc_dointvec
,
3079 .procname
= "max_size",
3080 .data
= &ip_rt_max_size
,
3081 .maxlen
= sizeof(int),
3083 .proc_handler
= proc_dointvec
,
3086 /* Deprecated. Use gc_min_interval_ms */
3088 .procname
= "gc_min_interval",
3089 .data
= &ip_rt_gc_min_interval
,
3090 .maxlen
= sizeof(int),
3092 .proc_handler
= proc_dointvec_jiffies
,
3095 .procname
= "gc_min_interval_ms",
3096 .data
= &ip_rt_gc_min_interval
,
3097 .maxlen
= sizeof(int),
3099 .proc_handler
= proc_dointvec_ms_jiffies
,
3102 .procname
= "gc_timeout",
3103 .data
= &ip_rt_gc_timeout
,
3104 .maxlen
= sizeof(int),
3106 .proc_handler
= proc_dointvec_jiffies
,
3109 .procname
= "gc_interval",
3110 .data
= &ip_rt_gc_interval
,
3111 .maxlen
= sizeof(int),
3113 .proc_handler
= proc_dointvec_jiffies
,
3116 .procname
= "redirect_load",
3117 .data
= &ip_rt_redirect_load
,
3118 .maxlen
= sizeof(int),
3120 .proc_handler
= proc_dointvec
,
3123 .procname
= "redirect_number",
3124 .data
= &ip_rt_redirect_number
,
3125 .maxlen
= sizeof(int),
3127 .proc_handler
= proc_dointvec
,
3130 .procname
= "redirect_silence",
3131 .data
= &ip_rt_redirect_silence
,
3132 .maxlen
= sizeof(int),
3134 .proc_handler
= proc_dointvec
,
3137 .procname
= "error_cost",
3138 .data
= &ip_rt_error_cost
,
3139 .maxlen
= sizeof(int),
3141 .proc_handler
= proc_dointvec
,
3144 .procname
= "error_burst",
3145 .data
= &ip_rt_error_burst
,
3146 .maxlen
= sizeof(int),
3148 .proc_handler
= proc_dointvec
,
3151 .procname
= "gc_elasticity",
3152 .data
= &ip_rt_gc_elasticity
,
3153 .maxlen
= sizeof(int),
3155 .proc_handler
= proc_dointvec
,
3158 .procname
= "mtu_expires",
3159 .data
= &ip_rt_mtu_expires
,
3160 .maxlen
= sizeof(int),
3162 .proc_handler
= proc_dointvec_jiffies
,
3165 .procname
= "min_pmtu",
3166 .data
= &ip_rt_min_pmtu
,
3167 .maxlen
= sizeof(int),
3169 .proc_handler
= proc_dointvec
,
3172 .procname
= "min_adv_mss",
3173 .data
= &ip_rt_min_advmss
,
3174 .maxlen
= sizeof(int),
3176 .proc_handler
= proc_dointvec
,
3181 static struct ctl_table empty
[1];
3183 static struct ctl_table ipv4_skeleton
[] =
3185 { .procname
= "route",
3186 .mode
= 0555, .child
= ipv4_route_table
},
3187 { .procname
= "neigh",
3188 .mode
= 0555, .child
= empty
},
3192 static __net_initdata
struct ctl_path ipv4_path
[] = {
3193 { .procname
= "net", },
3194 { .procname
= "ipv4", },
3198 static struct ctl_table ipv4_route_flush_table
[] = {
3200 .procname
= "flush",
3201 .maxlen
= sizeof(int),
3203 .proc_handler
= ipv4_sysctl_rtcache_flush
,
3208 static __net_initdata
struct ctl_path ipv4_route_path
[] = {
3209 { .procname
= "net", },
3210 { .procname
= "ipv4", },
3211 { .procname
= "route", },
3215 static __net_init
int sysctl_route_net_init(struct net
*net
)
3217 struct ctl_table
*tbl
;
3219 tbl
= ipv4_route_flush_table
;
3220 if (!net_eq(net
, &init_net
)) {
3221 tbl
= kmemdup(tbl
, sizeof(ipv4_route_flush_table
), GFP_KERNEL
);
3225 tbl
[0].extra1
= net
;
3227 net
->ipv4
.route_hdr
=
3228 register_net_sysctl_table(net
, ipv4_route_path
, tbl
);
3229 if (net
->ipv4
.route_hdr
== NULL
)
3234 if (tbl
!= ipv4_route_flush_table
)
3240 static __net_exit
void sysctl_route_net_exit(struct net
*net
)
3242 struct ctl_table
*tbl
;
3244 tbl
= net
->ipv4
.route_hdr
->ctl_table_arg
;
3245 unregister_net_sysctl_table(net
->ipv4
.route_hdr
);
3246 BUG_ON(tbl
== ipv4_route_flush_table
);
3250 static __net_initdata
struct pernet_operations sysctl_route_ops
= {
3251 .init
= sysctl_route_net_init
,
3252 .exit
= sysctl_route_net_exit
,
3256 static __net_init
int rt_genid_init(struct net
*net
)
3258 get_random_bytes(&net
->ipv4
.rt_genid
,
3259 sizeof(net
->ipv4
.rt_genid
));
3260 get_random_bytes(&net
->ipv4
.dev_addr_genid
,
3261 sizeof(net
->ipv4
.dev_addr_genid
));
3265 static __net_initdata
struct pernet_operations rt_genid_ops
= {
3266 .init
= rt_genid_init
,
3270 #ifdef CONFIG_IP_ROUTE_CLASSID
3271 struct ip_rt_acct __percpu
*ip_rt_acct __read_mostly
;
3272 #endif /* CONFIG_IP_ROUTE_CLASSID */
3274 static __initdata
unsigned long rhash_entries
;
3275 static int __init
set_rhash_entries(char *str
)
3279 rhash_entries
= simple_strtoul(str
, &str
, 0);
3282 __setup("rhash_entries=", set_rhash_entries
);
3284 int __init
ip_rt_init(void)
3288 #ifdef CONFIG_IP_ROUTE_CLASSID
3289 ip_rt_acct
= __alloc_percpu(256 * sizeof(struct ip_rt_acct
), __alignof__(struct ip_rt_acct
));
3291 panic("IP: failed to allocate ip_rt_acct\n");
3294 ipv4_dst_ops
.kmem_cachep
=
3295 kmem_cache_create("ip_dst_cache", sizeof(struct rtable
), 0,
3296 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3298 ipv4_dst_blackhole_ops
.kmem_cachep
= ipv4_dst_ops
.kmem_cachep
;
3300 if (dst_entries_init(&ipv4_dst_ops
) < 0)
3301 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3303 if (dst_entries_init(&ipv4_dst_blackhole_ops
) < 0)
3304 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3306 rt_hash_table
= (struct rt_hash_bucket
*)
3307 alloc_large_system_hash("IP route cache",
3308 sizeof(struct rt_hash_bucket
),
3310 (totalram_pages
>= 128 * 1024) ?
3315 rhash_entries
? 0 : 512 * 1024);
3316 memset(rt_hash_table
, 0, (rt_hash_mask
+ 1) * sizeof(struct rt_hash_bucket
));
3317 rt_hash_lock_init();
3319 ipv4_dst_ops
.gc_thresh
= (rt_hash_mask
+ 1);
3320 ip_rt_max_size
= (rt_hash_mask
+ 1) * 16;
3325 if (ip_rt_proc_init())
3326 printk(KERN_ERR
"Unable to create route proc files\n");
3329 xfrm4_init(ip_rt_max_size
);
3331 rtnl_register(PF_INET
, RTM_GETROUTE
, inet_rtm_getroute
, NULL
, NULL
);
3333 #ifdef CONFIG_SYSCTL
3334 register_pernet_subsys(&sysctl_route_ops
);
3336 register_pernet_subsys(&rt_genid_ops
);
3340 #ifdef CONFIG_SYSCTL
3342 * We really need to sanitize the damn ipv4 init order, then all
3343 * this nonsense will go away.
3345 void __init
ip_static_sysctl_init(void)
3347 register_sysctl_paths(ipv4_path
, ipv4_skeleton
);