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 #define pr_fmt(fmt) "IPv4: " fmt
67 #include <linux/module.h>
68 #include <asm/uaccess.h>
69 #include <linux/bitops.h>
70 #include <linux/types.h>
71 #include <linux/kernel.h>
73 #include <linux/bootmem.h>
74 #include <linux/string.h>
75 #include <linux/socket.h>
76 #include <linux/sockios.h>
77 #include <linux/errno.h>
79 #include <linux/inet.h>
80 #include <linux/netdevice.h>
81 #include <linux/proc_fs.h>
82 #include <linux/init.h>
83 #include <linux/workqueue.h>
84 #include <linux/skbuff.h>
85 #include <linux/inetdevice.h>
86 #include <linux/igmp.h>
87 #include <linux/pkt_sched.h>
88 #include <linux/mroute.h>
89 #include <linux/netfilter_ipv4.h>
90 #include <linux/random.h>
91 #include <linux/jhash.h>
92 #include <linux/rcupdate.h>
93 #include <linux/times.h>
94 #include <linux/slab.h>
95 #include <linux/prefetch.h>
97 #include <net/net_namespace.h>
98 #include <net/protocol.h>
100 #include <net/route.h>
101 #include <net/inetpeer.h>
102 #include <net/sock.h>
103 #include <net/ip_fib.h>
106 #include <net/icmp.h>
107 #include <net/xfrm.h>
108 #include <net/netevent.h>
109 #include <net/rtnetlink.h>
111 #include <linux/sysctl.h>
112 #include <linux/kmemleak.h>
114 #include <net/secure_seq.h>
116 #define RT_FL_TOS(oldflp4) \
117 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
119 #define IP_MAX_MTU 0xFFF0
121 #define RT_GC_TIMEOUT (300*HZ)
123 static int ip_rt_max_size
;
124 static int ip_rt_gc_timeout __read_mostly
= RT_GC_TIMEOUT
;
125 static int ip_rt_gc_interval __read_mostly
= 60 * HZ
;
126 static int ip_rt_gc_min_interval __read_mostly
= HZ
/ 2;
127 static int ip_rt_redirect_number __read_mostly
= 9;
128 static int ip_rt_redirect_load __read_mostly
= HZ
/ 50;
129 static int ip_rt_redirect_silence __read_mostly
= ((HZ
/ 50) << (9 + 1));
130 static int ip_rt_error_cost __read_mostly
= HZ
;
131 static int ip_rt_error_burst __read_mostly
= 5 * HZ
;
132 static int ip_rt_gc_elasticity __read_mostly
= 8;
133 static int ip_rt_mtu_expires __read_mostly
= 10 * 60 * HZ
;
134 static int ip_rt_min_pmtu __read_mostly
= 512 + 20 + 20;
135 static int ip_rt_min_advmss __read_mostly
= 256;
136 static int rt_chain_length_max __read_mostly
= 20;
138 static struct delayed_work expires_work
;
139 static unsigned long expires_ljiffies
;
142 * Interface to generic destination cache.
145 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
);
146 static unsigned int ipv4_default_advmss(const struct dst_entry
*dst
);
147 static unsigned int ipv4_mtu(const struct dst_entry
*dst
);
148 static void ipv4_dst_destroy(struct dst_entry
*dst
);
149 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
);
150 static void ipv4_link_failure(struct sk_buff
*skb
);
151 static void ip_rt_update_pmtu(struct dst_entry
*dst
, u32 mtu
);
152 static int rt_garbage_collect(struct dst_ops
*ops
);
154 static void ipv4_dst_ifdown(struct dst_entry
*dst
, struct net_device
*dev
,
159 static u32
*ipv4_cow_metrics(struct dst_entry
*dst
, unsigned long old
)
161 struct rtable
*rt
= (struct rtable
*) dst
;
162 struct inet_peer
*peer
;
165 peer
= rt_get_peer_create(rt
, rt
->rt_dst
);
167 u32
*old_p
= __DST_METRICS_PTR(old
);
168 unsigned long prev
, new;
171 if (inet_metrics_new(peer
))
172 memcpy(p
, old_p
, sizeof(u32
) * RTAX_MAX
);
174 new = (unsigned long) p
;
175 prev
= cmpxchg(&dst
->_metrics
, old
, new);
178 p
= __DST_METRICS_PTR(prev
);
179 if (prev
& DST_METRICS_READ_ONLY
)
183 fib_info_put(rt
->fi
);
191 static struct neighbour
*ipv4_neigh_lookup(const struct dst_entry
*dst
,
195 static struct dst_ops ipv4_dst_ops
= {
197 .protocol
= cpu_to_be16(ETH_P_IP
),
198 .gc
= rt_garbage_collect
,
199 .check
= ipv4_dst_check
,
200 .default_advmss
= ipv4_default_advmss
,
202 .cow_metrics
= ipv4_cow_metrics
,
203 .destroy
= ipv4_dst_destroy
,
204 .ifdown
= ipv4_dst_ifdown
,
205 .negative_advice
= ipv4_negative_advice
,
206 .link_failure
= ipv4_link_failure
,
207 .update_pmtu
= ip_rt_update_pmtu
,
208 .local_out
= __ip_local_out
,
209 .neigh_lookup
= ipv4_neigh_lookup
,
212 #define ECN_OR_COST(class) TC_PRIO_##class
214 const __u8 ip_tos2prio
[16] = {
216 ECN_OR_COST(BESTEFFORT
),
218 ECN_OR_COST(BESTEFFORT
),
224 ECN_OR_COST(INTERACTIVE
),
226 ECN_OR_COST(INTERACTIVE
),
227 TC_PRIO_INTERACTIVE_BULK
,
228 ECN_OR_COST(INTERACTIVE_BULK
),
229 TC_PRIO_INTERACTIVE_BULK
,
230 ECN_OR_COST(INTERACTIVE_BULK
)
232 EXPORT_SYMBOL(ip_tos2prio
);
238 /* The locking scheme is rather straight forward:
240 * 1) Read-Copy Update protects the buckets of the central route hash.
241 * 2) Only writers remove entries, and they hold the lock
242 * as they look at rtable reference counts.
243 * 3) Only readers acquire references to rtable entries,
244 * they do so with atomic increments and with the
248 struct rt_hash_bucket
{
249 struct rtable __rcu
*chain
;
252 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
253 defined(CONFIG_PROVE_LOCKING)
255 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
256 * The size of this table is a power of two and depends on the number of CPUS.
257 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
259 #ifdef CONFIG_LOCKDEP
260 # define RT_HASH_LOCK_SZ 256
263 # define RT_HASH_LOCK_SZ 4096
265 # define RT_HASH_LOCK_SZ 2048
267 # define RT_HASH_LOCK_SZ 1024
269 # define RT_HASH_LOCK_SZ 512
271 # define RT_HASH_LOCK_SZ 256
275 static spinlock_t
*rt_hash_locks
;
276 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
278 static __init
void rt_hash_lock_init(void)
282 rt_hash_locks
= kmalloc(sizeof(spinlock_t
) * RT_HASH_LOCK_SZ
,
285 panic("IP: failed to allocate rt_hash_locks\n");
287 for (i
= 0; i
< RT_HASH_LOCK_SZ
; i
++)
288 spin_lock_init(&rt_hash_locks
[i
]);
291 # define rt_hash_lock_addr(slot) NULL
293 static inline void rt_hash_lock_init(void)
298 static struct rt_hash_bucket
*rt_hash_table __read_mostly
;
299 static unsigned int rt_hash_mask __read_mostly
;
300 static unsigned int rt_hash_log __read_mostly
;
302 static DEFINE_PER_CPU(struct rt_cache_stat
, rt_cache_stat
);
303 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
305 static inline unsigned int rt_hash(__be32 daddr
, __be32 saddr
, int idx
,
308 return jhash_3words((__force u32
)daddr
, (__force u32
)saddr
,
313 static inline int rt_genid(struct net
*net
)
315 return atomic_read(&net
->ipv4
.rt_genid
);
318 #ifdef CONFIG_PROC_FS
319 struct rt_cache_iter_state
{
320 struct seq_net_private p
;
325 static struct rtable
*rt_cache_get_first(struct seq_file
*seq
)
327 struct rt_cache_iter_state
*st
= seq
->private;
328 struct rtable
*r
= NULL
;
330 for (st
->bucket
= rt_hash_mask
; st
->bucket
>= 0; --st
->bucket
) {
331 if (!rcu_access_pointer(rt_hash_table
[st
->bucket
].chain
))
334 r
= rcu_dereference_bh(rt_hash_table
[st
->bucket
].chain
);
336 if (dev_net(r
->dst
.dev
) == seq_file_net(seq
) &&
337 r
->rt_genid
== st
->genid
)
339 r
= rcu_dereference_bh(r
->dst
.rt_next
);
341 rcu_read_unlock_bh();
346 static struct rtable
*__rt_cache_get_next(struct seq_file
*seq
,
349 struct rt_cache_iter_state
*st
= seq
->private;
351 r
= rcu_dereference_bh(r
->dst
.rt_next
);
353 rcu_read_unlock_bh();
355 if (--st
->bucket
< 0)
357 } while (!rcu_access_pointer(rt_hash_table
[st
->bucket
].chain
));
359 r
= rcu_dereference_bh(rt_hash_table
[st
->bucket
].chain
);
364 static struct rtable
*rt_cache_get_next(struct seq_file
*seq
,
367 struct rt_cache_iter_state
*st
= seq
->private;
368 while ((r
= __rt_cache_get_next(seq
, r
)) != NULL
) {
369 if (dev_net(r
->dst
.dev
) != seq_file_net(seq
))
371 if (r
->rt_genid
== st
->genid
)
377 static struct rtable
*rt_cache_get_idx(struct seq_file
*seq
, loff_t pos
)
379 struct rtable
*r
= rt_cache_get_first(seq
);
382 while (pos
&& (r
= rt_cache_get_next(seq
, r
)))
384 return pos
? NULL
: r
;
387 static void *rt_cache_seq_start(struct seq_file
*seq
, loff_t
*pos
)
389 struct rt_cache_iter_state
*st
= seq
->private;
391 return rt_cache_get_idx(seq
, *pos
- 1);
392 st
->genid
= rt_genid(seq_file_net(seq
));
393 return SEQ_START_TOKEN
;
396 static void *rt_cache_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
400 if (v
== SEQ_START_TOKEN
)
401 r
= rt_cache_get_first(seq
);
403 r
= rt_cache_get_next(seq
, v
);
408 static void rt_cache_seq_stop(struct seq_file
*seq
, void *v
)
410 if (v
&& v
!= SEQ_START_TOKEN
)
411 rcu_read_unlock_bh();
414 static int rt_cache_seq_show(struct seq_file
*seq
, void *v
)
416 if (v
== SEQ_START_TOKEN
)
417 seq_printf(seq
, "%-127s\n",
418 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
419 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
422 struct rtable
*r
= v
;
425 seq_printf(seq
, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
426 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
427 r
->dst
.dev
? r
->dst
.dev
->name
: "*",
428 (__force u32
)r
->rt_dst
,
429 (__force u32
)r
->rt_gateway
,
430 r
->rt_flags
, atomic_read(&r
->dst
.__refcnt
),
431 r
->dst
.__use
, 0, (__force u32
)r
->rt_src
,
432 dst_metric_advmss(&r
->dst
) + 40,
433 dst_metric(&r
->dst
, RTAX_WINDOW
), 0,
437 seq_printf(seq
, "%*s\n", 127 - len
, "");
442 static const struct seq_operations rt_cache_seq_ops
= {
443 .start
= rt_cache_seq_start
,
444 .next
= rt_cache_seq_next
,
445 .stop
= rt_cache_seq_stop
,
446 .show
= rt_cache_seq_show
,
449 static int rt_cache_seq_open(struct inode
*inode
, struct file
*file
)
451 return seq_open_net(inode
, file
, &rt_cache_seq_ops
,
452 sizeof(struct rt_cache_iter_state
));
455 static const struct file_operations rt_cache_seq_fops
= {
456 .owner
= THIS_MODULE
,
457 .open
= rt_cache_seq_open
,
460 .release
= seq_release_net
,
464 static void *rt_cpu_seq_start(struct seq_file
*seq
, loff_t
*pos
)
469 return SEQ_START_TOKEN
;
471 for (cpu
= *pos
-1; cpu
< nr_cpu_ids
; ++cpu
) {
472 if (!cpu_possible(cpu
))
475 return &per_cpu(rt_cache_stat
, cpu
);
480 static void *rt_cpu_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
484 for (cpu
= *pos
; cpu
< nr_cpu_ids
; ++cpu
) {
485 if (!cpu_possible(cpu
))
488 return &per_cpu(rt_cache_stat
, cpu
);
494 static void rt_cpu_seq_stop(struct seq_file
*seq
, void *v
)
499 static int rt_cpu_seq_show(struct seq_file
*seq
, void *v
)
501 struct rt_cache_stat
*st
= v
;
503 if (v
== SEQ_START_TOKEN
) {
504 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");
508 seq_printf(seq
,"%08x %08x %08x %08x %08x %08x %08x %08x "
509 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
510 dst_entries_get_slow(&ipv4_dst_ops
),
533 static const struct seq_operations rt_cpu_seq_ops
= {
534 .start
= rt_cpu_seq_start
,
535 .next
= rt_cpu_seq_next
,
536 .stop
= rt_cpu_seq_stop
,
537 .show
= rt_cpu_seq_show
,
541 static int rt_cpu_seq_open(struct inode
*inode
, struct file
*file
)
543 return seq_open(file
, &rt_cpu_seq_ops
);
546 static const struct file_operations rt_cpu_seq_fops
= {
547 .owner
= THIS_MODULE
,
548 .open
= rt_cpu_seq_open
,
551 .release
= seq_release
,
554 #ifdef CONFIG_IP_ROUTE_CLASSID
555 static int rt_acct_proc_show(struct seq_file
*m
, void *v
)
557 struct ip_rt_acct
*dst
, *src
;
560 dst
= kcalloc(256, sizeof(struct ip_rt_acct
), GFP_KERNEL
);
564 for_each_possible_cpu(i
) {
565 src
= (struct ip_rt_acct
*)per_cpu_ptr(ip_rt_acct
, i
);
566 for (j
= 0; j
< 256; j
++) {
567 dst
[j
].o_bytes
+= src
[j
].o_bytes
;
568 dst
[j
].o_packets
+= src
[j
].o_packets
;
569 dst
[j
].i_bytes
+= src
[j
].i_bytes
;
570 dst
[j
].i_packets
+= src
[j
].i_packets
;
574 seq_write(m
, dst
, 256 * sizeof(struct ip_rt_acct
));
579 static int rt_acct_proc_open(struct inode
*inode
, struct file
*file
)
581 return single_open(file
, rt_acct_proc_show
, NULL
);
584 static const struct file_operations rt_acct_proc_fops
= {
585 .owner
= THIS_MODULE
,
586 .open
= rt_acct_proc_open
,
589 .release
= single_release
,
593 static int __net_init
ip_rt_do_proc_init(struct net
*net
)
595 struct proc_dir_entry
*pde
;
597 pde
= proc_net_fops_create(net
, "rt_cache", S_IRUGO
,
602 pde
= proc_create("rt_cache", S_IRUGO
,
603 net
->proc_net_stat
, &rt_cpu_seq_fops
);
607 #ifdef CONFIG_IP_ROUTE_CLASSID
608 pde
= proc_create("rt_acct", 0, net
->proc_net
, &rt_acct_proc_fops
);
614 #ifdef CONFIG_IP_ROUTE_CLASSID
616 remove_proc_entry("rt_cache", net
->proc_net_stat
);
619 remove_proc_entry("rt_cache", net
->proc_net
);
624 static void __net_exit
ip_rt_do_proc_exit(struct net
*net
)
626 remove_proc_entry("rt_cache", net
->proc_net_stat
);
627 remove_proc_entry("rt_cache", net
->proc_net
);
628 #ifdef CONFIG_IP_ROUTE_CLASSID
629 remove_proc_entry("rt_acct", net
->proc_net
);
633 static struct pernet_operations ip_rt_proc_ops __net_initdata
= {
634 .init
= ip_rt_do_proc_init
,
635 .exit
= ip_rt_do_proc_exit
,
638 static int __init
ip_rt_proc_init(void)
640 return register_pernet_subsys(&ip_rt_proc_ops
);
644 static inline int ip_rt_proc_init(void)
648 #endif /* CONFIG_PROC_FS */
650 static inline void rt_free(struct rtable
*rt
)
652 call_rcu_bh(&rt
->dst
.rcu_head
, dst_rcu_free
);
655 static inline void rt_drop(struct rtable
*rt
)
658 call_rcu_bh(&rt
->dst
.rcu_head
, dst_rcu_free
);
661 static inline int rt_fast_clean(struct rtable
*rth
)
663 /* Kill broadcast/multicast entries very aggresively, if they
664 collide in hash table with more useful entries */
665 return (rth
->rt_flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) &&
666 rt_is_input_route(rth
) && rth
->dst
.rt_next
;
669 static inline int rt_valuable(struct rtable
*rth
)
671 return (rth
->rt_flags
& (RTCF_REDIRECTED
| RTCF_NOTIFY
)) ||
675 static int rt_may_expire(struct rtable
*rth
, unsigned long tmo1
, unsigned long tmo2
)
680 if (atomic_read(&rth
->dst
.__refcnt
))
683 age
= jiffies
- rth
->dst
.lastuse
;
684 if ((age
<= tmo1
&& !rt_fast_clean(rth
)) ||
685 (age
<= tmo2
&& rt_valuable(rth
)))
691 /* Bits of score are:
693 * 30: not quite useless
694 * 29..0: usage counter
696 static inline u32
rt_score(struct rtable
*rt
)
698 u32 score
= jiffies
- rt
->dst
.lastuse
;
700 score
= ~score
& ~(3<<30);
705 if (rt_is_output_route(rt
) ||
706 !(rt
->rt_flags
& (RTCF_BROADCAST
|RTCF_MULTICAST
|RTCF_LOCAL
)))
712 static inline bool rt_caching(const struct net
*net
)
714 return net
->ipv4
.current_rt_cache_rebuild_count
<=
715 net
->ipv4
.sysctl_rt_cache_rebuild_count
;
718 static inline bool compare_hash_inputs(const struct rtable
*rt1
,
719 const struct rtable
*rt2
)
721 return ((((__force u32
)rt1
->rt_key_dst
^ (__force u32
)rt2
->rt_key_dst
) |
722 ((__force u32
)rt1
->rt_key_src
^ (__force u32
)rt2
->rt_key_src
) |
723 (rt1
->rt_route_iif
^ rt2
->rt_route_iif
)) == 0);
726 static inline int compare_keys(struct rtable
*rt1
, struct rtable
*rt2
)
728 return (((__force u32
)rt1
->rt_key_dst
^ (__force u32
)rt2
->rt_key_dst
) |
729 ((__force u32
)rt1
->rt_key_src
^ (__force u32
)rt2
->rt_key_src
) |
730 (rt1
->rt_mark
^ rt2
->rt_mark
) |
731 (rt1
->rt_key_tos
^ rt2
->rt_key_tos
) |
732 (rt1
->rt_route_iif
^ rt2
->rt_route_iif
) |
733 (rt1
->rt_oif
^ rt2
->rt_oif
)) == 0;
736 static inline int compare_netns(struct rtable
*rt1
, struct rtable
*rt2
)
738 return net_eq(dev_net(rt1
->dst
.dev
), dev_net(rt2
->dst
.dev
));
741 static inline int rt_is_expired(struct rtable
*rth
)
743 return rth
->rt_genid
!= rt_genid(dev_net(rth
->dst
.dev
));
747 * Perform a full scan of hash table and free all entries.
748 * Can be called by a softirq or a process.
749 * In the later case, we want to be reschedule if necessary
751 static void rt_do_flush(struct net
*net
, int process_context
)
754 struct rtable
*rth
, *next
;
756 for (i
= 0; i
<= rt_hash_mask
; i
++) {
757 struct rtable __rcu
**pprev
;
760 if (process_context
&& need_resched())
762 rth
= rcu_access_pointer(rt_hash_table
[i
].chain
);
766 spin_lock_bh(rt_hash_lock_addr(i
));
769 pprev
= &rt_hash_table
[i
].chain
;
770 rth
= rcu_dereference_protected(*pprev
,
771 lockdep_is_held(rt_hash_lock_addr(i
)));
774 next
= rcu_dereference_protected(rth
->dst
.rt_next
,
775 lockdep_is_held(rt_hash_lock_addr(i
)));
778 net_eq(dev_net(rth
->dst
.dev
), net
)) {
779 rcu_assign_pointer(*pprev
, next
);
780 rcu_assign_pointer(rth
->dst
.rt_next
, list
);
783 pprev
= &rth
->dst
.rt_next
;
788 spin_unlock_bh(rt_hash_lock_addr(i
));
790 for (; list
; list
= next
) {
791 next
= rcu_dereference_protected(list
->dst
.rt_next
, 1);
798 * While freeing expired entries, we compute average chain length
799 * and standard deviation, using fixed-point arithmetic.
800 * This to have an estimation of rt_chain_length_max
801 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
802 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
806 #define ONE (1UL << FRACT_BITS)
809 * Given a hash chain and an item in this hash chain,
810 * find if a previous entry has the same hash_inputs
811 * (but differs on tos, mark or oif)
812 * Returns 0 if an alias is found.
813 * Returns ONE if rth has no alias before itself.
815 static int has_noalias(const struct rtable
*head
, const struct rtable
*rth
)
817 const struct rtable
*aux
= head
;
820 if (compare_hash_inputs(aux
, rth
))
822 aux
= rcu_dereference_protected(aux
->dst
.rt_next
, 1);
827 static void rt_check_expire(void)
829 static unsigned int rover
;
830 unsigned int i
= rover
, goal
;
832 struct rtable __rcu
**rthp
;
833 unsigned long samples
= 0;
834 unsigned long sum
= 0, sum2
= 0;
838 delta
= jiffies
- expires_ljiffies
;
839 expires_ljiffies
= jiffies
;
840 mult
= ((u64
)delta
) << rt_hash_log
;
841 if (ip_rt_gc_timeout
> 1)
842 do_div(mult
, ip_rt_gc_timeout
);
843 goal
= (unsigned int)mult
;
844 if (goal
> rt_hash_mask
)
845 goal
= rt_hash_mask
+ 1;
846 for (; goal
> 0; goal
--) {
847 unsigned long tmo
= ip_rt_gc_timeout
;
848 unsigned long length
;
850 i
= (i
+ 1) & rt_hash_mask
;
851 rthp
= &rt_hash_table
[i
].chain
;
858 if (rcu_dereference_raw(*rthp
) == NULL
)
861 spin_lock_bh(rt_hash_lock_addr(i
));
862 while ((rth
= rcu_dereference_protected(*rthp
,
863 lockdep_is_held(rt_hash_lock_addr(i
)))) != NULL
) {
864 prefetch(rth
->dst
.rt_next
);
865 if (rt_is_expired(rth
) ||
866 rt_may_expire(rth
, tmo
, ip_rt_gc_timeout
)) {
867 *rthp
= rth
->dst
.rt_next
;
872 /* We only count entries on a chain with equal
873 * hash inputs once so that entries for
874 * different QOS levels, and other non-hash
875 * input attributes don't unfairly skew the
879 rthp
= &rth
->dst
.rt_next
;
880 length
+= has_noalias(rt_hash_table
[i
].chain
, rth
);
882 spin_unlock_bh(rt_hash_lock_addr(i
));
884 sum2
+= length
*length
;
887 unsigned long avg
= sum
/ samples
;
888 unsigned long sd
= int_sqrt(sum2
/ samples
- avg
*avg
);
889 rt_chain_length_max
= max_t(unsigned long,
891 (avg
+ 4*sd
) >> FRACT_BITS
);
897 * rt_worker_func() is run in process context.
898 * we call rt_check_expire() to scan part of the hash table
900 static void rt_worker_func(struct work_struct
*work
)
903 schedule_delayed_work(&expires_work
, ip_rt_gc_interval
);
907 * Perturbation of rt_genid by a small quantity [1..256]
908 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
909 * many times (2^24) without giving recent rt_genid.
910 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
912 static void rt_cache_invalidate(struct net
*net
)
914 unsigned char shuffle
;
916 get_random_bytes(&shuffle
, sizeof(shuffle
));
917 atomic_add(shuffle
+ 1U, &net
->ipv4
.rt_genid
);
918 inetpeer_invalidate_family(AF_INET
);
922 * delay < 0 : invalidate cache (fast : entries will be deleted later)
923 * delay >= 0 : invalidate & flush cache (can be long)
925 void rt_cache_flush(struct net
*net
, int delay
)
927 rt_cache_invalidate(net
);
929 rt_do_flush(net
, !in_softirq());
932 /* Flush previous cache invalidated entries from the cache */
933 void rt_cache_flush_batch(struct net
*net
)
935 rt_do_flush(net
, !in_softirq());
938 static void rt_emergency_hash_rebuild(struct net
*net
)
940 net_warn_ratelimited("Route hash chain too long!\n");
941 rt_cache_invalidate(net
);
945 Short description of GC goals.
947 We want to build algorithm, which will keep routing cache
948 at some equilibrium point, when number of aged off entries
949 is kept approximately equal to newly generated ones.
951 Current expiration strength is variable "expire".
952 We try to adjust it dynamically, so that if networking
953 is idle expires is large enough to keep enough of warm entries,
954 and when load increases it reduces to limit cache size.
957 static int rt_garbage_collect(struct dst_ops
*ops
)
959 static unsigned long expire
= RT_GC_TIMEOUT
;
960 static unsigned long last_gc
;
962 static int equilibrium
;
964 struct rtable __rcu
**rthp
;
965 unsigned long now
= jiffies
;
967 int entries
= dst_entries_get_fast(&ipv4_dst_ops
);
970 * Garbage collection is pretty expensive,
971 * do not make it too frequently.
974 RT_CACHE_STAT_INC(gc_total
);
976 if (now
- last_gc
< ip_rt_gc_min_interval
&&
977 entries
< ip_rt_max_size
) {
978 RT_CACHE_STAT_INC(gc_ignored
);
982 entries
= dst_entries_get_slow(&ipv4_dst_ops
);
983 /* Calculate number of entries, which we want to expire now. */
984 goal
= entries
- (ip_rt_gc_elasticity
<< rt_hash_log
);
986 if (equilibrium
< ipv4_dst_ops
.gc_thresh
)
987 equilibrium
= ipv4_dst_ops
.gc_thresh
;
988 goal
= entries
- equilibrium
;
990 equilibrium
+= min_t(unsigned int, goal
>> 1, rt_hash_mask
+ 1);
991 goal
= entries
- equilibrium
;
994 /* We are in dangerous area. Try to reduce cache really
997 goal
= max_t(unsigned int, goal
>> 1, rt_hash_mask
+ 1);
998 equilibrium
= entries
- goal
;
1001 if (now
- last_gc
>= ip_rt_gc_min_interval
)
1005 equilibrium
+= goal
;
1012 for (i
= rt_hash_mask
, k
= rover
; i
>= 0; i
--) {
1013 unsigned long tmo
= expire
;
1015 k
= (k
+ 1) & rt_hash_mask
;
1016 rthp
= &rt_hash_table
[k
].chain
;
1017 spin_lock_bh(rt_hash_lock_addr(k
));
1018 while ((rth
= rcu_dereference_protected(*rthp
,
1019 lockdep_is_held(rt_hash_lock_addr(k
)))) != NULL
) {
1020 if (!rt_is_expired(rth
) &&
1021 !rt_may_expire(rth
, tmo
, expire
)) {
1023 rthp
= &rth
->dst
.rt_next
;
1026 *rthp
= rth
->dst
.rt_next
;
1030 spin_unlock_bh(rt_hash_lock_addr(k
));
1039 /* Goal is not achieved. We stop process if:
1041 - if expire reduced to zero. Otherwise, expire is halfed.
1042 - if table is not full.
1043 - if we are called from interrupt.
1044 - jiffies check is just fallback/debug loop breaker.
1045 We will not spin here for long time in any case.
1048 RT_CACHE_STAT_INC(gc_goal_miss
);
1055 if (dst_entries_get_fast(&ipv4_dst_ops
) < ip_rt_max_size
)
1057 } while (!in_softirq() && time_before_eq(jiffies
, now
));
1059 if (dst_entries_get_fast(&ipv4_dst_ops
) < ip_rt_max_size
)
1061 if (dst_entries_get_slow(&ipv4_dst_ops
) < ip_rt_max_size
)
1063 net_warn_ratelimited("dst cache overflow\n");
1064 RT_CACHE_STAT_INC(gc_dst_overflow
);
1068 expire
+= ip_rt_gc_min_interval
;
1069 if (expire
> ip_rt_gc_timeout
||
1070 dst_entries_get_fast(&ipv4_dst_ops
) < ipv4_dst_ops
.gc_thresh
||
1071 dst_entries_get_slow(&ipv4_dst_ops
) < ipv4_dst_ops
.gc_thresh
)
1072 expire
= ip_rt_gc_timeout
;
1077 * Returns number of entries in a hash chain that have different hash_inputs
1079 static int slow_chain_length(const struct rtable
*head
)
1082 const struct rtable
*rth
= head
;
1085 length
+= has_noalias(head
, rth
);
1086 rth
= rcu_dereference_protected(rth
->dst
.rt_next
, 1);
1088 return length
>> FRACT_BITS
;
1091 static struct neighbour
*ipv4_neigh_lookup(const struct dst_entry
*dst
,
1092 struct sk_buff
*skb
,
1095 struct net_device
*dev
= dst
->dev
;
1096 const __be32
*pkey
= daddr
;
1097 const struct rtable
*rt
;
1098 struct neighbour
*n
;
1100 rt
= (const struct rtable
*) dst
;
1102 pkey
= (const __be32
*) &rt
->rt_gateway
;
1104 pkey
= &ip_hdr(skb
)->daddr
;
1106 n
= __ipv4_neigh_lookup(dev
, *(__force u32
*)pkey
);
1109 return neigh_create(&arp_tbl
, pkey
, dev
);
1112 static struct rtable
*rt_intern_hash(unsigned int hash
, struct rtable
*rt
,
1113 struct sk_buff
*skb
, int ifindex
)
1115 struct rtable
*rth
, *cand
;
1116 struct rtable __rcu
**rthp
, **candp
;
1123 min_score
= ~(u32
)0;
1128 if (!rt_caching(dev_net(rt
->dst
.dev
)) || (rt
->dst
.flags
& DST_NOCACHE
)) {
1130 * If we're not caching, just tell the caller we
1131 * were successful and don't touch the route. The
1132 * caller hold the sole reference to the cache entry, and
1133 * it will be released when the caller is done with it.
1134 * If we drop it here, the callers have no way to resolve routes
1135 * when we're not caching. Instead, just point *rp at rt, so
1136 * the caller gets a single use out of the route
1137 * Note that we do rt_free on this new route entry, so that
1138 * once its refcount hits zero, we are still able to reap it
1140 * Note: To avoid expensive rcu stuff for this uncached dst,
1141 * we set DST_NOCACHE so that dst_release() can free dst without
1142 * waiting a grace period.
1145 rt
->dst
.flags
|= DST_NOCACHE
;
1149 rthp
= &rt_hash_table
[hash
].chain
;
1151 spin_lock_bh(rt_hash_lock_addr(hash
));
1152 while ((rth
= rcu_dereference_protected(*rthp
,
1153 lockdep_is_held(rt_hash_lock_addr(hash
)))) != NULL
) {
1154 if (rt_is_expired(rth
)) {
1155 *rthp
= rth
->dst
.rt_next
;
1159 if (compare_keys(rth
, rt
) && compare_netns(rth
, rt
)) {
1161 *rthp
= rth
->dst
.rt_next
;
1163 * Since lookup is lockfree, the deletion
1164 * must be visible to another weakly ordered CPU before
1165 * the insertion at the start of the hash chain.
1167 rcu_assign_pointer(rth
->dst
.rt_next
,
1168 rt_hash_table
[hash
].chain
);
1170 * Since lookup is lockfree, the update writes
1171 * must be ordered for consistency on SMP.
1173 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rth
);
1175 dst_use(&rth
->dst
, now
);
1176 spin_unlock_bh(rt_hash_lock_addr(hash
));
1180 skb_dst_set(skb
, &rth
->dst
);
1184 if (!atomic_read(&rth
->dst
.__refcnt
)) {
1185 u32 score
= rt_score(rth
);
1187 if (score
<= min_score
) {
1196 rthp
= &rth
->dst
.rt_next
;
1200 /* ip_rt_gc_elasticity used to be average length of chain
1201 * length, when exceeded gc becomes really aggressive.
1203 * The second limit is less certain. At the moment it allows
1204 * only 2 entries per bucket. We will see.
1206 if (chain_length
> ip_rt_gc_elasticity
) {
1207 *candp
= cand
->dst
.rt_next
;
1211 if (chain_length
> rt_chain_length_max
&&
1212 slow_chain_length(rt_hash_table
[hash
].chain
) > rt_chain_length_max
) {
1213 struct net
*net
= dev_net(rt
->dst
.dev
);
1214 int num
= ++net
->ipv4
.current_rt_cache_rebuild_count
;
1215 if (!rt_caching(net
)) {
1216 pr_warn("%s: %d rebuilds is over limit, route caching disabled\n",
1217 rt
->dst
.dev
->name
, num
);
1219 rt_emergency_hash_rebuild(net
);
1220 spin_unlock_bh(rt_hash_lock_addr(hash
));
1222 hash
= rt_hash(rt
->rt_key_dst
, rt
->rt_key_src
,
1223 ifindex
, rt_genid(net
));
1228 rt
->dst
.rt_next
= rt_hash_table
[hash
].chain
;
1231 * Since lookup is lockfree, we must make sure
1232 * previous writes to rt are committed to memory
1233 * before making rt visible to other CPUS.
1235 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rt
);
1237 spin_unlock_bh(rt_hash_lock_addr(hash
));
1241 skb_dst_set(skb
, &rt
->dst
);
1245 void rt_bind_peer(struct rtable
*rt
, __be32 daddr
, int create
)
1247 struct inet_peer_base
*base
;
1248 struct inet_peer
*peer
;
1250 base
= inetpeer_base_ptr(rt
->_peer
);
1254 peer
= inet_getpeer_v4(base
, daddr
, create
);
1256 if (!rt_set_peer(rt
, peer
))
1262 * Peer allocation may fail only in serious out-of-memory conditions. However
1263 * we still can generate some output.
1264 * Random ID selection looks a bit dangerous because we have no chances to
1265 * select ID being unique in a reasonable period of time.
1266 * But broken packet identifier may be better than no packet at all.
1268 static void ip_select_fb_ident(struct iphdr
*iph
)
1270 static DEFINE_SPINLOCK(ip_fb_id_lock
);
1271 static u32 ip_fallback_id
;
1274 spin_lock_bh(&ip_fb_id_lock
);
1275 salt
= secure_ip_id((__force __be32
)ip_fallback_id
^ iph
->daddr
);
1276 iph
->id
= htons(salt
& 0xFFFF);
1277 ip_fallback_id
= salt
;
1278 spin_unlock_bh(&ip_fb_id_lock
);
1281 void __ip_select_ident(struct iphdr
*iph
, struct dst_entry
*dst
, int more
)
1283 struct net
*net
= dev_net(dst
->dev
);
1284 struct inet_peer
*peer
;
1286 peer
= inet_getpeer_v4(net
->ipv4
.peers
, iph
->daddr
, 1);
1288 iph
->id
= htons(inet_getid(peer
, more
));
1293 ip_select_fb_ident(iph
);
1295 EXPORT_SYMBOL(__ip_select_ident
);
1297 static void rt_del(unsigned int hash
, struct rtable
*rt
)
1299 struct rtable __rcu
**rthp
;
1302 rthp
= &rt_hash_table
[hash
].chain
;
1303 spin_lock_bh(rt_hash_lock_addr(hash
));
1305 while ((aux
= rcu_dereference_protected(*rthp
,
1306 lockdep_is_held(rt_hash_lock_addr(hash
)))) != NULL
) {
1307 if (aux
== rt
|| rt_is_expired(aux
)) {
1308 *rthp
= aux
->dst
.rt_next
;
1312 rthp
= &aux
->dst
.rt_next
;
1314 spin_unlock_bh(rt_hash_lock_addr(hash
));
1317 /* called in rcu_read_lock() section */
1318 void ip_rt_redirect(__be32 old_gw
, __be32 daddr
, __be32 new_gw
,
1319 __be32 saddr
, struct net_device
*dev
)
1322 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
1323 __be32 skeys
[2] = { saddr
, 0 };
1324 int ikeys
[2] = { dev
->ifindex
, 0 };
1331 if (new_gw
== old_gw
|| !IN_DEV_RX_REDIRECTS(in_dev
) ||
1332 ipv4_is_multicast(new_gw
) || ipv4_is_lbcast(new_gw
) ||
1333 ipv4_is_zeronet(new_gw
))
1334 goto reject_redirect
;
1336 if (!IN_DEV_SHARED_MEDIA(in_dev
)) {
1337 if (!inet_addr_onlink(in_dev
, new_gw
, old_gw
))
1338 goto reject_redirect
;
1339 if (IN_DEV_SEC_REDIRECTS(in_dev
) && ip_fib_check_default(new_gw
, dev
))
1340 goto reject_redirect
;
1342 if (inet_addr_type(net
, new_gw
) != RTN_UNICAST
)
1343 goto reject_redirect
;
1346 for (s
= 0; s
< 2; s
++) {
1347 for (i
= 0; i
< 2; i
++) {
1349 struct rtable __rcu
**rthp
;
1352 hash
= rt_hash(daddr
, skeys
[s
], ikeys
[i
], rt_genid(net
));
1354 rthp
= &rt_hash_table
[hash
].chain
;
1356 while ((rt
= rcu_dereference(*rthp
)) != NULL
) {
1357 struct neighbour
*n
;
1359 rthp
= &rt
->dst
.rt_next
;
1361 if (rt
->rt_key_dst
!= daddr
||
1362 rt
->rt_key_src
!= skeys
[s
] ||
1363 rt
->rt_oif
!= ikeys
[i
] ||
1364 rt_is_input_route(rt
) ||
1365 rt_is_expired(rt
) ||
1366 !net_eq(dev_net(rt
->dst
.dev
), net
) ||
1368 rt
->dst
.dev
!= dev
||
1369 rt
->rt_gateway
!= old_gw
)
1372 n
= ipv4_neigh_lookup(&rt
->dst
, NULL
, &new_gw
);
1374 if (!(n
->nud_state
& NUD_VALID
)) {
1375 neigh_event_send(n
, NULL
);
1377 rt
->rt_gateway
= new_gw
;
1378 rt
->rt_flags
|= RTCF_REDIRECTED
;
1379 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE
, n
);
1389 #ifdef CONFIG_IP_ROUTE_VERBOSE
1390 if (IN_DEV_LOG_MARTIANS(in_dev
))
1391 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
1392 " Advised path = %pI4 -> %pI4\n",
1393 &old_gw
, dev
->name
, &new_gw
,
1399 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
)
1401 struct rtable
*rt
= (struct rtable
*)dst
;
1402 struct dst_entry
*ret
= dst
;
1405 if (dst
->obsolete
> 0) {
1408 } else if ((rt
->rt_flags
& RTCF_REDIRECTED
) ||
1410 unsigned int hash
= rt_hash(rt
->rt_key_dst
, rt
->rt_key_src
,
1412 rt_genid(dev_net(dst
->dev
)));
1422 * 1. The first ip_rt_redirect_number redirects are sent
1423 * with exponential backoff, then we stop sending them at all,
1424 * assuming that the host ignores our redirects.
1425 * 2. If we did not see packets requiring redirects
1426 * during ip_rt_redirect_silence, we assume that the host
1427 * forgot redirected route and start to send redirects again.
1429 * This algorithm is much cheaper and more intelligent than dumb load limiting
1432 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1433 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1436 void ip_rt_send_redirect(struct sk_buff
*skb
)
1438 struct rtable
*rt
= skb_rtable(skb
);
1439 struct in_device
*in_dev
;
1440 struct inet_peer
*peer
;
1445 in_dev
= __in_dev_get_rcu(rt
->dst
.dev
);
1446 if (!in_dev
|| !IN_DEV_TX_REDIRECTS(in_dev
)) {
1450 log_martians
= IN_DEV_LOG_MARTIANS(in_dev
);
1453 net
= dev_net(rt
->dst
.dev
);
1454 peer
= inet_getpeer_v4(net
->ipv4
.peers
, ip_hdr(skb
)->saddr
, 1);
1456 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, rt
->rt_gateway
);
1460 /* No redirected packets during ip_rt_redirect_silence;
1461 * reset the algorithm.
1463 if (time_after(jiffies
, peer
->rate_last
+ ip_rt_redirect_silence
))
1464 peer
->rate_tokens
= 0;
1466 /* Too many ignored redirects; do not send anything
1467 * set dst.rate_last to the last seen redirected packet.
1469 if (peer
->rate_tokens
>= ip_rt_redirect_number
) {
1470 peer
->rate_last
= jiffies
;
1474 /* Check for load limit; set rate_last to the latest sent
1477 if (peer
->rate_tokens
== 0 ||
1480 (ip_rt_redirect_load
<< peer
->rate_tokens
)))) {
1481 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, rt
->rt_gateway
);
1482 peer
->rate_last
= jiffies
;
1483 ++peer
->rate_tokens
;
1484 #ifdef CONFIG_IP_ROUTE_VERBOSE
1486 peer
->rate_tokens
== ip_rt_redirect_number
)
1487 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
1488 &ip_hdr(skb
)->saddr
, rt
->rt_iif
,
1489 &rt
->rt_dst
, &rt
->rt_gateway
);
1496 static int ip_error(struct sk_buff
*skb
)
1498 struct in_device
*in_dev
= __in_dev_get_rcu(skb
->dev
);
1499 struct rtable
*rt
= skb_rtable(skb
);
1500 struct inet_peer
*peer
;
1506 net
= dev_net(rt
->dst
.dev
);
1507 if (!IN_DEV_FORWARD(in_dev
)) {
1508 switch (rt
->dst
.error
) {
1510 IP_INC_STATS_BH(net
, IPSTATS_MIB_INADDRERRORS
);
1514 IP_INC_STATS_BH(net
, IPSTATS_MIB_INNOROUTES
);
1520 switch (rt
->dst
.error
) {
1525 code
= ICMP_HOST_UNREACH
;
1528 code
= ICMP_NET_UNREACH
;
1529 IP_INC_STATS_BH(net
, IPSTATS_MIB_INNOROUTES
);
1532 code
= ICMP_PKT_FILTERED
;
1536 peer
= inet_getpeer_v4(net
->ipv4
.peers
, ip_hdr(skb
)->saddr
, 1);
1541 peer
->rate_tokens
+= now
- peer
->rate_last
;
1542 if (peer
->rate_tokens
> ip_rt_error_burst
)
1543 peer
->rate_tokens
= ip_rt_error_burst
;
1544 peer
->rate_last
= now
;
1545 if (peer
->rate_tokens
>= ip_rt_error_cost
)
1546 peer
->rate_tokens
-= ip_rt_error_cost
;
1552 icmp_send(skb
, ICMP_DEST_UNREACH
, code
, 0);
1554 out
: kfree_skb(skb
);
1558 static void ip_rt_update_pmtu(struct dst_entry
*dst
, u32 mtu
)
1560 struct rtable
*rt
= (struct rtable
*) dst
;
1564 if (mtu
< ip_rt_min_pmtu
)
1565 mtu
= ip_rt_min_pmtu
;
1568 dst_set_expires(&rt
->dst
, ip_rt_mtu_expires
);
1571 void ipv4_update_pmtu(struct sk_buff
*skb
, struct net
*net
, u32 mtu
,
1572 int oif
, u32 mark
, u8 protocol
, int flow_flags
)
1574 const struct iphdr
*iph
= (const struct iphdr
*)skb
->data
;
1578 flowi4_init_output(&fl4
, oif
, mark
, RT_TOS(iph
->tos
), RT_SCOPE_UNIVERSE
,
1579 protocol
, flow_flags
,
1580 iph
->daddr
, iph
->saddr
, 0, 0);
1581 rt
= __ip_route_output_key(net
, &fl4
);
1583 ip_rt_update_pmtu(&rt
->dst
, mtu
);
1587 EXPORT_SYMBOL_GPL(ipv4_update_pmtu
);
1589 void ipv4_sk_update_pmtu(struct sk_buff
*skb
, struct sock
*sk
, u32 mtu
)
1591 const struct inet_sock
*inet
= inet_sk(sk
);
1593 return ipv4_update_pmtu(skb
, sock_net(sk
), mtu
,
1594 sk
->sk_bound_dev_if
, sk
->sk_mark
,
1595 inet
->hdrincl
? IPPROTO_RAW
: sk
->sk_protocol
,
1596 inet_sk_flowi_flags(sk
));
1598 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu
);
1600 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
)
1602 struct rtable
*rt
= (struct rtable
*) dst
;
1604 if (rt_is_expired(rt
))
1609 static void ipv4_dst_destroy(struct dst_entry
*dst
)
1611 struct rtable
*rt
= (struct rtable
*) dst
;
1614 fib_info_put(rt
->fi
);
1617 if (rt_has_peer(rt
)) {
1618 struct inet_peer
*peer
= rt_peer_ptr(rt
);
1624 static void ipv4_link_failure(struct sk_buff
*skb
)
1628 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_HOST_UNREACH
, 0);
1630 rt
= skb_rtable(skb
);
1632 dst_set_expires(&rt
->dst
, 0);
1635 static int ip_rt_bug(struct sk_buff
*skb
)
1637 pr_debug("%s: %pI4 -> %pI4, %s\n",
1638 __func__
, &ip_hdr(skb
)->saddr
, &ip_hdr(skb
)->daddr
,
1639 skb
->dev
? skb
->dev
->name
: "?");
1646 We do not cache source address of outgoing interface,
1647 because it is used only by IP RR, TS and SRR options,
1648 so that it out of fast path.
1650 BTW remember: "addr" is allowed to be not aligned
1654 void ip_rt_get_source(u8
*addr
, struct sk_buff
*skb
, struct rtable
*rt
)
1658 if (rt_is_output_route(rt
))
1659 src
= ip_hdr(skb
)->saddr
;
1661 struct fib_result res
;
1667 memset(&fl4
, 0, sizeof(fl4
));
1668 fl4
.daddr
= iph
->daddr
;
1669 fl4
.saddr
= iph
->saddr
;
1670 fl4
.flowi4_tos
= RT_TOS(iph
->tos
);
1671 fl4
.flowi4_oif
= rt
->dst
.dev
->ifindex
;
1672 fl4
.flowi4_iif
= skb
->dev
->ifindex
;
1673 fl4
.flowi4_mark
= skb
->mark
;
1676 if (fib_lookup(dev_net(rt
->dst
.dev
), &fl4
, &res
) == 0)
1677 src
= FIB_RES_PREFSRC(dev_net(rt
->dst
.dev
), res
);
1679 src
= inet_select_addr(rt
->dst
.dev
, rt
->rt_gateway
,
1683 memcpy(addr
, &src
, 4);
1686 #ifdef CONFIG_IP_ROUTE_CLASSID
1687 static void set_class_tag(struct rtable
*rt
, u32 tag
)
1689 if (!(rt
->dst
.tclassid
& 0xFFFF))
1690 rt
->dst
.tclassid
|= tag
& 0xFFFF;
1691 if (!(rt
->dst
.tclassid
& 0xFFFF0000))
1692 rt
->dst
.tclassid
|= tag
& 0xFFFF0000;
1696 static unsigned int ipv4_default_advmss(const struct dst_entry
*dst
)
1698 unsigned int advmss
= dst_metric_raw(dst
, RTAX_ADVMSS
);
1701 advmss
= max_t(unsigned int, dst
->dev
->mtu
- 40,
1703 if (advmss
> 65535 - 40)
1704 advmss
= 65535 - 40;
1709 static unsigned int ipv4_mtu(const struct dst_entry
*dst
)
1711 const struct rtable
*rt
= (const struct rtable
*) dst
;
1712 unsigned int mtu
= rt
->rt_pmtu
;
1714 if (mtu
&& time_after_eq(jiffies
, rt
->dst
.expires
))
1718 mtu
= dst_metric_raw(dst
, RTAX_MTU
);
1720 if (mtu
&& rt_is_output_route(rt
))
1723 mtu
= dst
->dev
->mtu
;
1725 if (unlikely(dst_metric_locked(dst
, RTAX_MTU
))) {
1727 if (rt
->rt_gateway
!= rt
->rt_dst
&& mtu
> 576)
1731 if (mtu
> IP_MAX_MTU
)
1737 static void rt_init_metrics(struct rtable
*rt
, const struct flowi4
*fl4
,
1738 struct fib_info
*fi
)
1740 struct inet_peer_base
*base
;
1741 struct inet_peer
*peer
;
1743 base
= inetpeer_base_ptr(rt
->_peer
);
1746 peer
= inet_getpeer_v4(base
, rt
->rt_dst
, 0);
1748 __rt_set_peer(rt
, peer
);
1749 if (inet_metrics_new(peer
))
1750 memcpy(peer
->metrics
, fi
->fib_metrics
,
1751 sizeof(u32
) * RTAX_MAX
);
1752 dst_init_metrics(&rt
->dst
, peer
->metrics
, false);
1754 if (fi
->fib_metrics
!= (u32
*) dst_default_metrics
) {
1756 atomic_inc(&fi
->fib_clntref
);
1758 dst_init_metrics(&rt
->dst
, fi
->fib_metrics
, true);
1762 static void rt_set_nexthop(struct rtable
*rt
, const struct flowi4
*fl4
,
1763 const struct fib_result
*res
,
1764 struct fib_info
*fi
, u16 type
, u32 itag
)
1767 if (FIB_RES_GW(*res
) &&
1768 FIB_RES_NH(*res
).nh_scope
== RT_SCOPE_LINK
)
1769 rt
->rt_gateway
= FIB_RES_GW(*res
);
1770 rt_init_metrics(rt
, fl4
, fi
);
1771 #ifdef CONFIG_IP_ROUTE_CLASSID
1772 rt
->dst
.tclassid
= FIB_RES_NH(*res
).nh_tclassid
;
1776 #ifdef CONFIG_IP_ROUTE_CLASSID
1777 #ifdef CONFIG_IP_MULTIPLE_TABLES
1778 set_class_tag(rt
, fib_rules_tclass(res
));
1780 set_class_tag(rt
, itag
);
1784 static struct rtable
*rt_dst_alloc(struct net_device
*dev
,
1785 bool nopolicy
, bool noxfrm
)
1787 return dst_alloc(&ipv4_dst_ops
, dev
, 1, -1,
1789 (nopolicy
? DST_NOPOLICY
: 0) |
1790 (noxfrm
? DST_NOXFRM
: 0));
1793 /* called in rcu_read_lock() section */
1794 static int ip_route_input_mc(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
1795 u8 tos
, struct net_device
*dev
, int our
)
1799 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
1803 /* Primary sanity checks. */
1808 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
) ||
1809 skb
->protocol
!= htons(ETH_P_IP
))
1812 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev
)))
1813 if (ipv4_is_loopback(saddr
))
1816 if (ipv4_is_zeronet(saddr
)) {
1817 if (!ipv4_is_local_multicast(daddr
))
1820 err
= fib_validate_source(skb
, saddr
, 0, tos
, 0, dev
,
1825 rth
= rt_dst_alloc(dev_net(dev
)->loopback_dev
,
1826 IN_DEV_CONF_GET(in_dev
, NOPOLICY
), false);
1830 #ifdef CONFIG_IP_ROUTE_CLASSID
1831 rth
->dst
.tclassid
= itag
;
1833 rth
->dst
.output
= ip_rt_bug
;
1835 rth
->rt_key_dst
= daddr
;
1836 rth
->rt_key_src
= saddr
;
1837 rth
->rt_genid
= rt_genid(dev_net(dev
));
1838 rth
->rt_flags
= RTCF_MULTICAST
;
1839 rth
->rt_type
= RTN_MULTICAST
;
1840 rth
->rt_key_tos
= tos
;
1841 rth
->rt_dst
= daddr
;
1842 rth
->rt_src
= saddr
;
1843 rth
->rt_route_iif
= dev
->ifindex
;
1844 rth
->rt_iif
= dev
->ifindex
;
1846 rth
->rt_mark
= skb
->mark
;
1848 rth
->rt_gateway
= daddr
;
1849 rt_init_peer(rth
, dev_net(dev
)->ipv4
.peers
);
1852 rth
->dst
.input
= ip_local_deliver
;
1853 rth
->rt_flags
|= RTCF_LOCAL
;
1856 #ifdef CONFIG_IP_MROUTE
1857 if (!ipv4_is_local_multicast(daddr
) && IN_DEV_MFORWARD(in_dev
))
1858 rth
->dst
.input
= ip_mr_input
;
1860 RT_CACHE_STAT_INC(in_slow_mc
);
1862 hash
= rt_hash(daddr
, saddr
, dev
->ifindex
, rt_genid(dev_net(dev
)));
1863 rth
= rt_intern_hash(hash
, rth
, skb
, dev
->ifindex
);
1864 return IS_ERR(rth
) ? PTR_ERR(rth
) : 0;
1875 static void ip_handle_martian_source(struct net_device
*dev
,
1876 struct in_device
*in_dev
,
1877 struct sk_buff
*skb
,
1881 RT_CACHE_STAT_INC(in_martian_src
);
1882 #ifdef CONFIG_IP_ROUTE_VERBOSE
1883 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit()) {
1885 * RFC1812 recommendation, if source is martian,
1886 * the only hint is MAC header.
1888 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1889 &daddr
, &saddr
, dev
->name
);
1890 if (dev
->hard_header_len
&& skb_mac_header_was_set(skb
)) {
1891 print_hex_dump(KERN_WARNING
, "ll header: ",
1892 DUMP_PREFIX_OFFSET
, 16, 1,
1893 skb_mac_header(skb
),
1894 dev
->hard_header_len
, true);
1900 /* called in rcu_read_lock() section */
1901 static int __mkroute_input(struct sk_buff
*skb
,
1902 const struct fib_result
*res
,
1903 struct in_device
*in_dev
,
1904 __be32 daddr
, __be32 saddr
, u32 tos
,
1905 struct rtable
**result
)
1909 struct in_device
*out_dev
;
1910 unsigned int flags
= 0;
1913 /* get a working reference to the output device */
1914 out_dev
= __in_dev_get_rcu(FIB_RES_DEV(*res
));
1915 if (out_dev
== NULL
) {
1916 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1921 err
= fib_validate_source(skb
, saddr
, daddr
, tos
, FIB_RES_OIF(*res
),
1922 in_dev
->dev
, in_dev
, &itag
);
1924 ip_handle_martian_source(in_dev
->dev
, in_dev
, skb
, daddr
,
1931 flags
|= RTCF_DIRECTSRC
;
1933 if (out_dev
== in_dev
&& err
&&
1934 (IN_DEV_SHARED_MEDIA(out_dev
) ||
1935 inet_addr_onlink(out_dev
, saddr
, FIB_RES_GW(*res
))))
1936 flags
|= RTCF_DOREDIRECT
;
1938 if (skb
->protocol
!= htons(ETH_P_IP
)) {
1939 /* Not IP (i.e. ARP). Do not create route, if it is
1940 * invalid for proxy arp. DNAT routes are always valid.
1942 * Proxy arp feature have been extended to allow, ARP
1943 * replies back to the same interface, to support
1944 * Private VLAN switch technologies. See arp.c.
1946 if (out_dev
== in_dev
&&
1947 IN_DEV_PROXY_ARP_PVLAN(in_dev
) == 0) {
1953 rth
= rt_dst_alloc(out_dev
->dev
,
1954 IN_DEV_CONF_GET(in_dev
, NOPOLICY
),
1955 IN_DEV_CONF_GET(out_dev
, NOXFRM
));
1961 rth
->rt_key_dst
= daddr
;
1962 rth
->rt_key_src
= saddr
;
1963 rth
->rt_genid
= rt_genid(dev_net(rth
->dst
.dev
));
1964 rth
->rt_flags
= flags
;
1965 rth
->rt_type
= res
->type
;
1966 rth
->rt_key_tos
= tos
;
1967 rth
->rt_dst
= daddr
;
1968 rth
->rt_src
= saddr
;
1969 rth
->rt_route_iif
= in_dev
->dev
->ifindex
;
1970 rth
->rt_iif
= in_dev
->dev
->ifindex
;
1972 rth
->rt_mark
= skb
->mark
;
1974 rth
->rt_gateway
= daddr
;
1975 rt_init_peer(rth
, &res
->table
->tb_peers
);
1978 rth
->dst
.input
= ip_forward
;
1979 rth
->dst
.output
= ip_output
;
1981 rt_set_nexthop(rth
, NULL
, res
, res
->fi
, res
->type
, itag
);
1989 static int ip_mkroute_input(struct sk_buff
*skb
,
1990 struct fib_result
*res
,
1991 const struct flowi4
*fl4
,
1992 struct in_device
*in_dev
,
1993 __be32 daddr
, __be32 saddr
, u32 tos
)
1995 struct rtable
*rth
= NULL
;
1999 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2000 if (res
->fi
&& res
->fi
->fib_nhs
> 1)
2001 fib_select_multipath(res
);
2004 /* create a routing cache entry */
2005 err
= __mkroute_input(skb
, res
, in_dev
, daddr
, saddr
, tos
, &rth
);
2009 /* put it into the cache */
2010 hash
= rt_hash(daddr
, saddr
, fl4
->flowi4_iif
,
2011 rt_genid(dev_net(rth
->dst
.dev
)));
2012 rth
= rt_intern_hash(hash
, rth
, skb
, fl4
->flowi4_iif
);
2014 return PTR_ERR(rth
);
2019 * NOTE. We drop all the packets that has local source
2020 * addresses, because every properly looped back packet
2021 * must have correct destination already attached by output routine.
2023 * Such approach solves two big problems:
2024 * 1. Not simplex devices are handled properly.
2025 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2026 * called with rcu_read_lock()
2029 static int ip_route_input_slow(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2030 u8 tos
, struct net_device
*dev
)
2032 struct fib_result res
;
2033 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
2035 unsigned int flags
= 0;
2040 struct net
*net
= dev_net(dev
);
2042 /* IP on this device is disabled. */
2047 /* Check for the most weird martians, which can be not detected
2051 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
))
2052 goto martian_source
;
2054 if (ipv4_is_lbcast(daddr
) || (saddr
== 0 && daddr
== 0))
2057 /* Accept zero addresses only to limited broadcast;
2058 * I even do not know to fix it or not. Waiting for complains :-)
2060 if (ipv4_is_zeronet(saddr
))
2061 goto martian_source
;
2063 if (ipv4_is_zeronet(daddr
))
2064 goto martian_destination
;
2066 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev
))) {
2067 if (ipv4_is_loopback(daddr
))
2068 goto martian_destination
;
2070 if (ipv4_is_loopback(saddr
))
2071 goto martian_source
;
2075 * Now we are ready to route packet.
2078 fl4
.flowi4_iif
= dev
->ifindex
;
2079 fl4
.flowi4_mark
= skb
->mark
;
2080 fl4
.flowi4_tos
= tos
;
2081 fl4
.flowi4_scope
= RT_SCOPE_UNIVERSE
;
2084 err
= fib_lookup(net
, &fl4
, &res
);
2088 RT_CACHE_STAT_INC(in_slow_tot
);
2090 if (res
.type
== RTN_BROADCAST
)
2093 if (res
.type
== RTN_LOCAL
) {
2094 err
= fib_validate_source(skb
, saddr
, daddr
, tos
,
2095 net
->loopback_dev
->ifindex
,
2096 dev
, in_dev
, &itag
);
2098 goto martian_source_keep_err
;
2100 flags
|= RTCF_DIRECTSRC
;
2104 if (!IN_DEV_FORWARD(in_dev
))
2106 if (res
.type
!= RTN_UNICAST
)
2107 goto martian_destination
;
2109 err
= ip_mkroute_input(skb
, &res
, &fl4
, in_dev
, daddr
, saddr
, tos
);
2113 if (skb
->protocol
!= htons(ETH_P_IP
))
2116 if (!ipv4_is_zeronet(saddr
)) {
2117 err
= fib_validate_source(skb
, saddr
, 0, tos
, 0, dev
,
2120 goto martian_source_keep_err
;
2122 flags
|= RTCF_DIRECTSRC
;
2124 flags
|= RTCF_BROADCAST
;
2125 res
.type
= RTN_BROADCAST
;
2126 RT_CACHE_STAT_INC(in_brd
);
2129 rth
= rt_dst_alloc(net
->loopback_dev
,
2130 IN_DEV_CONF_GET(in_dev
, NOPOLICY
), false);
2134 rth
->dst
.input
= ip_local_deliver
;
2135 rth
->dst
.output
= ip_rt_bug
;
2136 #ifdef CONFIG_IP_ROUTE_CLASSID
2137 rth
->dst
.tclassid
= itag
;
2140 rth
->rt_key_dst
= daddr
;
2141 rth
->rt_key_src
= saddr
;
2142 rth
->rt_genid
= rt_genid(net
);
2143 rth
->rt_flags
= flags
|RTCF_LOCAL
;
2144 rth
->rt_type
= res
.type
;
2145 rth
->rt_key_tos
= tos
;
2146 rth
->rt_dst
= daddr
;
2147 rth
->rt_src
= saddr
;
2148 rth
->rt_route_iif
= dev
->ifindex
;
2149 rth
->rt_iif
= dev
->ifindex
;
2151 rth
->rt_mark
= skb
->mark
;
2153 rth
->rt_gateway
= daddr
;
2154 rt_init_peer(rth
, net
->ipv4
.peers
);
2156 if (res
.type
== RTN_UNREACHABLE
) {
2157 rth
->dst
.input
= ip_error
;
2158 rth
->dst
.error
= -err
;
2159 rth
->rt_flags
&= ~RTCF_LOCAL
;
2161 hash
= rt_hash(daddr
, saddr
, fl4
.flowi4_iif
, rt_genid(net
));
2162 rth
= rt_intern_hash(hash
, rth
, skb
, fl4
.flowi4_iif
);
2169 RT_CACHE_STAT_INC(in_no_route
);
2170 res
.type
= RTN_UNREACHABLE
;
2176 * Do not cache martian addresses: they should be logged (RFC1812)
2178 martian_destination
:
2179 RT_CACHE_STAT_INC(in_martian_dst
);
2180 #ifdef CONFIG_IP_ROUTE_VERBOSE
2181 if (IN_DEV_LOG_MARTIANS(in_dev
))
2182 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2183 &daddr
, &saddr
, dev
->name
);
2196 martian_source_keep_err
:
2197 ip_handle_martian_source(dev
, in_dev
, skb
, daddr
, saddr
);
2201 int ip_route_input_common(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2202 u8 tos
, struct net_device
*dev
, bool noref
)
2206 int iif
= dev
->ifindex
;
2214 if (!rt_caching(net
))
2217 tos
&= IPTOS_RT_MASK
;
2218 hash
= rt_hash(daddr
, saddr
, iif
, rt_genid(net
));
2220 for (rth
= rcu_dereference(rt_hash_table
[hash
].chain
); rth
;
2221 rth
= rcu_dereference(rth
->dst
.rt_next
)) {
2222 if ((((__force u32
)rth
->rt_key_dst
^ (__force u32
)daddr
) |
2223 ((__force u32
)rth
->rt_key_src
^ (__force u32
)saddr
) |
2224 (rth
->rt_route_iif
^ iif
) |
2225 (rth
->rt_key_tos
^ tos
)) == 0 &&
2226 rth
->rt_mark
== skb
->mark
&&
2227 net_eq(dev_net(rth
->dst
.dev
), net
) &&
2228 !rt_is_expired(rth
)) {
2230 dst_use_noref(&rth
->dst
, jiffies
);
2231 skb_dst_set_noref(skb
, &rth
->dst
);
2233 dst_use(&rth
->dst
, jiffies
);
2234 skb_dst_set(skb
, &rth
->dst
);
2236 RT_CACHE_STAT_INC(in_hit
);
2240 RT_CACHE_STAT_INC(in_hlist_search
);
2244 /* Multicast recognition logic is moved from route cache to here.
2245 The problem was that too many Ethernet cards have broken/missing
2246 hardware multicast filters :-( As result the host on multicasting
2247 network acquires a lot of useless route cache entries, sort of
2248 SDR messages from all the world. Now we try to get rid of them.
2249 Really, provided software IP multicast filter is organized
2250 reasonably (at least, hashed), it does not result in a slowdown
2251 comparing with route cache reject entries.
2252 Note, that multicast routers are not affected, because
2253 route cache entry is created eventually.
2255 if (ipv4_is_multicast(daddr
)) {
2256 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
2259 int our
= ip_check_mc_rcu(in_dev
, daddr
, saddr
,
2260 ip_hdr(skb
)->protocol
);
2262 #ifdef CONFIG_IP_MROUTE
2264 (!ipv4_is_local_multicast(daddr
) &&
2265 IN_DEV_MFORWARD(in_dev
))
2268 int res
= ip_route_input_mc(skb
, daddr
, saddr
,
2277 res
= ip_route_input_slow(skb
, daddr
, saddr
, tos
, dev
);
2281 EXPORT_SYMBOL(ip_route_input_common
);
2283 /* called with rcu_read_lock() */
2284 static struct rtable
*__mkroute_output(const struct fib_result
*res
,
2285 const struct flowi4
*fl4
,
2286 __be32 orig_daddr
, __be32 orig_saddr
,
2287 int orig_oif
, __u8 orig_rtos
,
2288 struct net_device
*dev_out
,
2291 struct fib_info
*fi
= res
->fi
;
2292 struct in_device
*in_dev
;
2293 u16 type
= res
->type
;
2296 in_dev
= __in_dev_get_rcu(dev_out
);
2298 return ERR_PTR(-EINVAL
);
2300 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev
)))
2301 if (ipv4_is_loopback(fl4
->saddr
) && !(dev_out
->flags
& IFF_LOOPBACK
))
2302 return ERR_PTR(-EINVAL
);
2304 if (ipv4_is_lbcast(fl4
->daddr
))
2305 type
= RTN_BROADCAST
;
2306 else if (ipv4_is_multicast(fl4
->daddr
))
2307 type
= RTN_MULTICAST
;
2308 else if (ipv4_is_zeronet(fl4
->daddr
))
2309 return ERR_PTR(-EINVAL
);
2311 if (dev_out
->flags
& IFF_LOOPBACK
)
2312 flags
|= RTCF_LOCAL
;
2314 if (type
== RTN_BROADCAST
) {
2315 flags
|= RTCF_BROADCAST
| RTCF_LOCAL
;
2317 } else if (type
== RTN_MULTICAST
) {
2318 flags
|= RTCF_MULTICAST
| RTCF_LOCAL
;
2319 if (!ip_check_mc_rcu(in_dev
, fl4
->daddr
, fl4
->saddr
,
2321 flags
&= ~RTCF_LOCAL
;
2322 /* If multicast route do not exist use
2323 * default one, but do not gateway in this case.
2326 if (fi
&& res
->prefixlen
< 4)
2330 rth
= rt_dst_alloc(dev_out
,
2331 IN_DEV_CONF_GET(in_dev
, NOPOLICY
),
2332 IN_DEV_CONF_GET(in_dev
, NOXFRM
));
2334 return ERR_PTR(-ENOBUFS
);
2336 rth
->dst
.output
= ip_output
;
2338 rth
->rt_key_dst
= orig_daddr
;
2339 rth
->rt_key_src
= orig_saddr
;
2340 rth
->rt_genid
= rt_genid(dev_net(dev_out
));
2341 rth
->rt_flags
= flags
;
2342 rth
->rt_type
= type
;
2343 rth
->rt_key_tos
= orig_rtos
;
2344 rth
->rt_dst
= fl4
->daddr
;
2345 rth
->rt_src
= fl4
->saddr
;
2346 rth
->rt_route_iif
= 0;
2347 rth
->rt_iif
= orig_oif
? : dev_out
->ifindex
;
2348 rth
->rt_oif
= orig_oif
;
2349 rth
->rt_mark
= fl4
->flowi4_mark
;
2351 rth
->rt_gateway
= fl4
->daddr
;
2352 rt_init_peer(rth
, (res
->table
?
2353 &res
->table
->tb_peers
:
2354 dev_net(dev_out
)->ipv4
.peers
));
2357 RT_CACHE_STAT_INC(out_slow_tot
);
2359 if (flags
& RTCF_LOCAL
)
2360 rth
->dst
.input
= ip_local_deliver
;
2361 if (flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) {
2362 if (flags
& RTCF_LOCAL
&&
2363 !(dev_out
->flags
& IFF_LOOPBACK
)) {
2364 rth
->dst
.output
= ip_mc_output
;
2365 RT_CACHE_STAT_INC(out_slow_mc
);
2367 #ifdef CONFIG_IP_MROUTE
2368 if (type
== RTN_MULTICAST
) {
2369 if (IN_DEV_MFORWARD(in_dev
) &&
2370 !ipv4_is_local_multicast(fl4
->daddr
)) {
2371 rth
->dst
.input
= ip_mr_input
;
2372 rth
->dst
.output
= ip_mc_output
;
2378 rt_set_nexthop(rth
, fl4
, res
, fi
, type
, 0);
2380 if (fl4
->flowi4_flags
& FLOWI_FLAG_RT_NOCACHE
)
2381 rth
->dst
.flags
|= DST_NOCACHE
;
2387 * Major route resolver routine.
2388 * called with rcu_read_lock();
2391 static struct rtable
*ip_route_output_slow(struct net
*net
, struct flowi4
*fl4
)
2393 struct net_device
*dev_out
= NULL
;
2394 __u8 tos
= RT_FL_TOS(fl4
);
2395 unsigned int flags
= 0;
2396 struct fib_result res
;
2404 #ifdef CONFIG_IP_MULTIPLE_TABLES
2408 orig_daddr
= fl4
->daddr
;
2409 orig_saddr
= fl4
->saddr
;
2410 orig_oif
= fl4
->flowi4_oif
;
2412 fl4
->flowi4_iif
= net
->loopback_dev
->ifindex
;
2413 fl4
->flowi4_tos
= tos
& IPTOS_RT_MASK
;
2414 fl4
->flowi4_scope
= ((tos
& RTO_ONLINK
) ?
2415 RT_SCOPE_LINK
: RT_SCOPE_UNIVERSE
);
2419 rth
= ERR_PTR(-EINVAL
);
2420 if (ipv4_is_multicast(fl4
->saddr
) ||
2421 ipv4_is_lbcast(fl4
->saddr
) ||
2422 ipv4_is_zeronet(fl4
->saddr
))
2425 /* I removed check for oif == dev_out->oif here.
2426 It was wrong for two reasons:
2427 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2428 is assigned to multiple interfaces.
2429 2. Moreover, we are allowed to send packets with saddr
2430 of another iface. --ANK
2433 if (fl4
->flowi4_oif
== 0 &&
2434 (ipv4_is_multicast(fl4
->daddr
) ||
2435 ipv4_is_lbcast(fl4
->daddr
))) {
2436 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2437 dev_out
= __ip_dev_find(net
, fl4
->saddr
, false);
2438 if (dev_out
== NULL
)
2441 /* Special hack: user can direct multicasts
2442 and limited broadcast via necessary interface
2443 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2444 This hack is not just for fun, it allows
2445 vic,vat and friends to work.
2446 They bind socket to loopback, set ttl to zero
2447 and expect that it will work.
2448 From the viewpoint of routing cache they are broken,
2449 because we are not allowed to build multicast path
2450 with loopback source addr (look, routing cache
2451 cannot know, that ttl is zero, so that packet
2452 will not leave this host and route is valid).
2453 Luckily, this hack is good workaround.
2456 fl4
->flowi4_oif
= dev_out
->ifindex
;
2460 if (!(fl4
->flowi4_flags
& FLOWI_FLAG_ANYSRC
)) {
2461 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2462 if (!__ip_dev_find(net
, fl4
->saddr
, false))
2468 if (fl4
->flowi4_oif
) {
2469 dev_out
= dev_get_by_index_rcu(net
, fl4
->flowi4_oif
);
2470 rth
= ERR_PTR(-ENODEV
);
2471 if (dev_out
== NULL
)
2474 /* RACE: Check return value of inet_select_addr instead. */
2475 if (!(dev_out
->flags
& IFF_UP
) || !__in_dev_get_rcu(dev_out
)) {
2476 rth
= ERR_PTR(-ENETUNREACH
);
2479 if (ipv4_is_local_multicast(fl4
->daddr
) ||
2480 ipv4_is_lbcast(fl4
->daddr
)) {
2482 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2487 if (ipv4_is_multicast(fl4
->daddr
))
2488 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2490 else if (!fl4
->daddr
)
2491 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2497 fl4
->daddr
= fl4
->saddr
;
2499 fl4
->daddr
= fl4
->saddr
= htonl(INADDR_LOOPBACK
);
2500 dev_out
= net
->loopback_dev
;
2501 fl4
->flowi4_oif
= net
->loopback_dev
->ifindex
;
2502 res
.type
= RTN_LOCAL
;
2503 flags
|= RTCF_LOCAL
;
2507 if (fib_lookup(net
, fl4
, &res
)) {
2510 if (fl4
->flowi4_oif
) {
2511 /* Apparently, routing tables are wrong. Assume,
2512 that the destination is on link.
2515 Because we are allowed to send to iface
2516 even if it has NO routes and NO assigned
2517 addresses. When oif is specified, routing
2518 tables are looked up with only one purpose:
2519 to catch if destination is gatewayed, rather than
2520 direct. Moreover, if MSG_DONTROUTE is set,
2521 we send packet, ignoring both routing tables
2522 and ifaddr state. --ANK
2525 We could make it even if oif is unknown,
2526 likely IPv6, but we do not.
2529 if (fl4
->saddr
== 0)
2530 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2532 res
.type
= RTN_UNICAST
;
2535 rth
= ERR_PTR(-ENETUNREACH
);
2539 if (res
.type
== RTN_LOCAL
) {
2541 if (res
.fi
->fib_prefsrc
)
2542 fl4
->saddr
= res
.fi
->fib_prefsrc
;
2544 fl4
->saddr
= fl4
->daddr
;
2546 dev_out
= net
->loopback_dev
;
2547 fl4
->flowi4_oif
= dev_out
->ifindex
;
2549 flags
|= RTCF_LOCAL
;
2553 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2554 if (res
.fi
->fib_nhs
> 1 && fl4
->flowi4_oif
== 0)
2555 fib_select_multipath(&res
);
2558 if (!res
.prefixlen
&&
2559 res
.table
->tb_num_default
> 1 &&
2560 res
.type
== RTN_UNICAST
&& !fl4
->flowi4_oif
)
2561 fib_select_default(&res
);
2564 fl4
->saddr
= FIB_RES_PREFSRC(net
, res
);
2566 dev_out
= FIB_RES_DEV(res
);
2567 fl4
->flowi4_oif
= dev_out
->ifindex
;
2571 rth
= __mkroute_output(&res
, fl4
, orig_daddr
, orig_saddr
, orig_oif
,
2572 tos
, dev_out
, flags
);
2576 hash
= rt_hash(orig_daddr
, orig_saddr
, orig_oif
,
2577 rt_genid(dev_net(dev_out
)));
2578 rth
= rt_intern_hash(hash
, rth
, NULL
, orig_oif
);
2586 struct rtable
*__ip_route_output_key(struct net
*net
, struct flowi4
*flp4
)
2591 if (!rt_caching(net
))
2594 hash
= rt_hash(flp4
->daddr
, flp4
->saddr
, flp4
->flowi4_oif
, rt_genid(net
));
2597 for (rth
= rcu_dereference_bh(rt_hash_table
[hash
].chain
); rth
;
2598 rth
= rcu_dereference_bh(rth
->dst
.rt_next
)) {
2599 if (rth
->rt_key_dst
== flp4
->daddr
&&
2600 rth
->rt_key_src
== flp4
->saddr
&&
2601 rt_is_output_route(rth
) &&
2602 rth
->rt_oif
== flp4
->flowi4_oif
&&
2603 rth
->rt_mark
== flp4
->flowi4_mark
&&
2604 !((rth
->rt_key_tos
^ flp4
->flowi4_tos
) &
2605 (IPTOS_RT_MASK
| RTO_ONLINK
)) &&
2606 net_eq(dev_net(rth
->dst
.dev
), net
) &&
2607 !rt_is_expired(rth
)) {
2608 dst_use(&rth
->dst
, jiffies
);
2609 RT_CACHE_STAT_INC(out_hit
);
2610 rcu_read_unlock_bh();
2612 flp4
->saddr
= rth
->rt_src
;
2614 flp4
->daddr
= rth
->rt_dst
;
2617 RT_CACHE_STAT_INC(out_hlist_search
);
2619 rcu_read_unlock_bh();
2622 return ip_route_output_slow(net
, flp4
);
2624 EXPORT_SYMBOL_GPL(__ip_route_output_key
);
2626 static struct dst_entry
*ipv4_blackhole_dst_check(struct dst_entry
*dst
, u32 cookie
)
2631 static unsigned int ipv4_blackhole_mtu(const struct dst_entry
*dst
)
2633 unsigned int mtu
= dst_metric_raw(dst
, RTAX_MTU
);
2635 return mtu
? : dst
->dev
->mtu
;
2638 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry
*dst
, u32 mtu
)
2642 static u32
*ipv4_rt_blackhole_cow_metrics(struct dst_entry
*dst
,
2648 static struct dst_ops ipv4_dst_blackhole_ops
= {
2650 .protocol
= cpu_to_be16(ETH_P_IP
),
2651 .destroy
= ipv4_dst_destroy
,
2652 .check
= ipv4_blackhole_dst_check
,
2653 .mtu
= ipv4_blackhole_mtu
,
2654 .default_advmss
= ipv4_default_advmss
,
2655 .update_pmtu
= ipv4_rt_blackhole_update_pmtu
,
2656 .cow_metrics
= ipv4_rt_blackhole_cow_metrics
,
2657 .neigh_lookup
= ipv4_neigh_lookup
,
2660 struct dst_entry
*ipv4_blackhole_route(struct net
*net
, struct dst_entry
*dst_orig
)
2662 struct rtable
*rt
= dst_alloc(&ipv4_dst_blackhole_ops
, NULL
, 1, 0, 0);
2663 struct rtable
*ort
= (struct rtable
*) dst_orig
;
2666 struct dst_entry
*new = &rt
->dst
;
2669 new->input
= dst_discard
;
2670 new->output
= dst_discard
;
2671 dst_copy_metrics(new, &ort
->dst
);
2673 new->dev
= ort
->dst
.dev
;
2677 rt
->rt_key_dst
= ort
->rt_key_dst
;
2678 rt
->rt_key_src
= ort
->rt_key_src
;
2679 rt
->rt_key_tos
= ort
->rt_key_tos
;
2680 rt
->rt_route_iif
= ort
->rt_route_iif
;
2681 rt
->rt_iif
= ort
->rt_iif
;
2682 rt
->rt_oif
= ort
->rt_oif
;
2683 rt
->rt_mark
= ort
->rt_mark
;
2684 rt
->rt_pmtu
= ort
->rt_pmtu
;
2686 rt
->rt_genid
= rt_genid(net
);
2687 rt
->rt_flags
= ort
->rt_flags
;
2688 rt
->rt_type
= ort
->rt_type
;
2689 rt
->rt_dst
= ort
->rt_dst
;
2690 rt
->rt_src
= ort
->rt_src
;
2691 rt
->rt_gateway
= ort
->rt_gateway
;
2692 rt_transfer_peer(rt
, ort
);
2695 atomic_inc(&rt
->fi
->fib_clntref
);
2700 dst_release(dst_orig
);
2702 return rt
? &rt
->dst
: ERR_PTR(-ENOMEM
);
2705 struct rtable
*ip_route_output_flow(struct net
*net
, struct flowi4
*flp4
,
2708 struct rtable
*rt
= __ip_route_output_key(net
, flp4
);
2713 if (flp4
->flowi4_proto
)
2714 rt
= (struct rtable
*) xfrm_lookup(net
, &rt
->dst
,
2715 flowi4_to_flowi(flp4
),
2720 EXPORT_SYMBOL_GPL(ip_route_output_flow
);
2722 static int rt_fill_info(struct net
*net
,
2723 struct sk_buff
*skb
, u32 pid
, u32 seq
, int event
,
2724 int nowait
, unsigned int flags
)
2726 struct rtable
*rt
= skb_rtable(skb
);
2728 struct nlmsghdr
*nlh
;
2729 unsigned long expires
= 0;
2732 nlh
= nlmsg_put(skb
, pid
, seq
, event
, sizeof(*r
), flags
);
2736 r
= nlmsg_data(nlh
);
2737 r
->rtm_family
= AF_INET
;
2738 r
->rtm_dst_len
= 32;
2740 r
->rtm_tos
= rt
->rt_key_tos
;
2741 r
->rtm_table
= RT_TABLE_MAIN
;
2742 if (nla_put_u32(skb
, RTA_TABLE
, RT_TABLE_MAIN
))
2743 goto nla_put_failure
;
2744 r
->rtm_type
= rt
->rt_type
;
2745 r
->rtm_scope
= RT_SCOPE_UNIVERSE
;
2746 r
->rtm_protocol
= RTPROT_UNSPEC
;
2747 r
->rtm_flags
= (rt
->rt_flags
& ~0xFFFF) | RTM_F_CLONED
;
2748 if (rt
->rt_flags
& RTCF_NOTIFY
)
2749 r
->rtm_flags
|= RTM_F_NOTIFY
;
2751 if (nla_put_be32(skb
, RTA_DST
, rt
->rt_dst
))
2752 goto nla_put_failure
;
2753 if (rt
->rt_key_src
) {
2754 r
->rtm_src_len
= 32;
2755 if (nla_put_be32(skb
, RTA_SRC
, rt
->rt_key_src
))
2756 goto nla_put_failure
;
2759 nla_put_u32(skb
, RTA_OIF
, rt
->dst
.dev
->ifindex
))
2760 goto nla_put_failure
;
2761 #ifdef CONFIG_IP_ROUTE_CLASSID
2762 if (rt
->dst
.tclassid
&&
2763 nla_put_u32(skb
, RTA_FLOW
, rt
->dst
.tclassid
))
2764 goto nla_put_failure
;
2766 if (!rt_is_input_route(rt
) &&
2767 rt
->rt_src
!= rt
->rt_key_src
) {
2768 if (nla_put_be32(skb
, RTA_PREFSRC
, rt
->rt_src
))
2769 goto nla_put_failure
;
2771 if (rt
->rt_dst
!= rt
->rt_gateway
&&
2772 nla_put_be32(skb
, RTA_GATEWAY
, rt
->rt_gateway
))
2773 goto nla_put_failure
;
2775 if (rtnetlink_put_metrics(skb
, dst_metrics_ptr(&rt
->dst
)) < 0)
2776 goto nla_put_failure
;
2779 nla_put_be32(skb
, RTA_MARK
, rt
->rt_mark
))
2780 goto nla_put_failure
;
2782 error
= rt
->dst
.error
;
2783 if (rt_has_peer(rt
)) {
2784 const struct inet_peer
*peer
= rt_peer_ptr(rt
);
2785 inet_peer_refcheck(peer
);
2786 id
= atomic_read(&peer
->ip_id_count
) & 0xffff;
2788 expires
= rt
->dst
.expires
;
2790 if (time_before(jiffies
, expires
))
2796 if (rt_is_input_route(rt
)) {
2797 #ifdef CONFIG_IP_MROUTE
2798 __be32 dst
= rt
->rt_dst
;
2800 if (ipv4_is_multicast(dst
) && !ipv4_is_local_multicast(dst
) &&
2801 IPV4_DEVCONF_ALL(net
, MC_FORWARDING
)) {
2802 int err
= ipmr_get_route(net
, skb
,
2803 rt
->rt_src
, rt
->rt_dst
,
2809 goto nla_put_failure
;
2811 if (err
== -EMSGSIZE
)
2812 goto nla_put_failure
;
2818 if (nla_put_u32(skb
, RTA_IIF
, rt
->rt_iif
))
2819 goto nla_put_failure
;
2822 if (rtnl_put_cacheinfo(skb
, &rt
->dst
, id
, expires
, error
) < 0)
2823 goto nla_put_failure
;
2825 return nlmsg_end(skb
, nlh
);
2828 nlmsg_cancel(skb
, nlh
);
2832 static int inet_rtm_getroute(struct sk_buff
*in_skb
, struct nlmsghdr
*nlh
, void *arg
)
2834 struct net
*net
= sock_net(in_skb
->sk
);
2836 struct nlattr
*tb
[RTA_MAX
+1];
2837 struct rtable
*rt
= NULL
;
2843 struct sk_buff
*skb
;
2845 err
= nlmsg_parse(nlh
, sizeof(*rtm
), tb
, RTA_MAX
, rtm_ipv4_policy
);
2849 rtm
= nlmsg_data(nlh
);
2851 skb
= alloc_skb(NLMSG_GOODSIZE
, GFP_KERNEL
);
2857 /* Reserve room for dummy headers, this skb can pass
2858 through good chunk of routing engine.
2860 skb_reset_mac_header(skb
);
2861 skb_reset_network_header(skb
);
2863 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2864 ip_hdr(skb
)->protocol
= IPPROTO_ICMP
;
2865 skb_reserve(skb
, MAX_HEADER
+ sizeof(struct iphdr
));
2867 src
= tb
[RTA_SRC
] ? nla_get_be32(tb
[RTA_SRC
]) : 0;
2868 dst
= tb
[RTA_DST
] ? nla_get_be32(tb
[RTA_DST
]) : 0;
2869 iif
= tb
[RTA_IIF
] ? nla_get_u32(tb
[RTA_IIF
]) : 0;
2870 mark
= tb
[RTA_MARK
] ? nla_get_u32(tb
[RTA_MARK
]) : 0;
2873 struct net_device
*dev
;
2875 dev
= __dev_get_by_index(net
, iif
);
2881 skb
->protocol
= htons(ETH_P_IP
);
2885 err
= ip_route_input(skb
, dst
, src
, rtm
->rtm_tos
, dev
);
2888 rt
= skb_rtable(skb
);
2889 if (err
== 0 && rt
->dst
.error
)
2890 err
= -rt
->dst
.error
;
2892 struct flowi4 fl4
= {
2895 .flowi4_tos
= rtm
->rtm_tos
,
2896 .flowi4_oif
= tb
[RTA_OIF
] ? nla_get_u32(tb
[RTA_OIF
]) : 0,
2897 .flowi4_mark
= mark
,
2899 rt
= ip_route_output_key(net
, &fl4
);
2909 skb_dst_set(skb
, &rt
->dst
);
2910 if (rtm
->rtm_flags
& RTM_F_NOTIFY
)
2911 rt
->rt_flags
|= RTCF_NOTIFY
;
2913 err
= rt_fill_info(net
, skb
, NETLINK_CB(in_skb
).pid
, nlh
->nlmsg_seq
,
2914 RTM_NEWROUTE
, 0, 0);
2918 err
= rtnl_unicast(skb
, net
, NETLINK_CB(in_skb
).pid
);
2927 int ip_rt_dump(struct sk_buff
*skb
, struct netlink_callback
*cb
)
2934 net
= sock_net(skb
->sk
);
2939 s_idx
= idx
= cb
->args
[1];
2940 for (h
= s_h
; h
<= rt_hash_mask
; h
++, s_idx
= 0) {
2941 if (!rt_hash_table
[h
].chain
)
2944 for (rt
= rcu_dereference_bh(rt_hash_table
[h
].chain
), idx
= 0; rt
;
2945 rt
= rcu_dereference_bh(rt
->dst
.rt_next
), idx
++) {
2946 if (!net_eq(dev_net(rt
->dst
.dev
), net
) || idx
< s_idx
)
2948 if (rt_is_expired(rt
))
2950 skb_dst_set_noref(skb
, &rt
->dst
);
2951 if (rt_fill_info(net
, skb
, NETLINK_CB(cb
->skb
).pid
,
2952 cb
->nlh
->nlmsg_seq
, RTM_NEWROUTE
,
2953 1, NLM_F_MULTI
) <= 0) {
2955 rcu_read_unlock_bh();
2960 rcu_read_unlock_bh();
2969 void ip_rt_multicast_event(struct in_device
*in_dev
)
2971 rt_cache_flush(dev_net(in_dev
->dev
), 0);
2974 #ifdef CONFIG_SYSCTL
2975 static int ipv4_sysctl_rtcache_flush(ctl_table
*__ctl
, int write
,
2976 void __user
*buffer
,
2977 size_t *lenp
, loff_t
*ppos
)
2984 memcpy(&ctl
, __ctl
, sizeof(ctl
));
2985 ctl
.data
= &flush_delay
;
2986 proc_dointvec(&ctl
, write
, buffer
, lenp
, ppos
);
2988 net
= (struct net
*)__ctl
->extra1
;
2989 rt_cache_flush(net
, flush_delay
);
2996 static ctl_table ipv4_route_table
[] = {
2998 .procname
= "gc_thresh",
2999 .data
= &ipv4_dst_ops
.gc_thresh
,
3000 .maxlen
= sizeof(int),
3002 .proc_handler
= proc_dointvec
,
3005 .procname
= "max_size",
3006 .data
= &ip_rt_max_size
,
3007 .maxlen
= sizeof(int),
3009 .proc_handler
= proc_dointvec
,
3012 /* Deprecated. Use gc_min_interval_ms */
3014 .procname
= "gc_min_interval",
3015 .data
= &ip_rt_gc_min_interval
,
3016 .maxlen
= sizeof(int),
3018 .proc_handler
= proc_dointvec_jiffies
,
3021 .procname
= "gc_min_interval_ms",
3022 .data
= &ip_rt_gc_min_interval
,
3023 .maxlen
= sizeof(int),
3025 .proc_handler
= proc_dointvec_ms_jiffies
,
3028 .procname
= "gc_timeout",
3029 .data
= &ip_rt_gc_timeout
,
3030 .maxlen
= sizeof(int),
3032 .proc_handler
= proc_dointvec_jiffies
,
3035 .procname
= "gc_interval",
3036 .data
= &ip_rt_gc_interval
,
3037 .maxlen
= sizeof(int),
3039 .proc_handler
= proc_dointvec_jiffies
,
3042 .procname
= "redirect_load",
3043 .data
= &ip_rt_redirect_load
,
3044 .maxlen
= sizeof(int),
3046 .proc_handler
= proc_dointvec
,
3049 .procname
= "redirect_number",
3050 .data
= &ip_rt_redirect_number
,
3051 .maxlen
= sizeof(int),
3053 .proc_handler
= proc_dointvec
,
3056 .procname
= "redirect_silence",
3057 .data
= &ip_rt_redirect_silence
,
3058 .maxlen
= sizeof(int),
3060 .proc_handler
= proc_dointvec
,
3063 .procname
= "error_cost",
3064 .data
= &ip_rt_error_cost
,
3065 .maxlen
= sizeof(int),
3067 .proc_handler
= proc_dointvec
,
3070 .procname
= "error_burst",
3071 .data
= &ip_rt_error_burst
,
3072 .maxlen
= sizeof(int),
3074 .proc_handler
= proc_dointvec
,
3077 .procname
= "gc_elasticity",
3078 .data
= &ip_rt_gc_elasticity
,
3079 .maxlen
= sizeof(int),
3081 .proc_handler
= proc_dointvec
,
3084 .procname
= "mtu_expires",
3085 .data
= &ip_rt_mtu_expires
,
3086 .maxlen
= sizeof(int),
3088 .proc_handler
= proc_dointvec_jiffies
,
3091 .procname
= "min_pmtu",
3092 .data
= &ip_rt_min_pmtu
,
3093 .maxlen
= sizeof(int),
3095 .proc_handler
= proc_dointvec
,
3098 .procname
= "min_adv_mss",
3099 .data
= &ip_rt_min_advmss
,
3100 .maxlen
= sizeof(int),
3102 .proc_handler
= proc_dointvec
,
3107 static struct ctl_table ipv4_route_flush_table
[] = {
3109 .procname
= "flush",
3110 .maxlen
= sizeof(int),
3112 .proc_handler
= ipv4_sysctl_rtcache_flush
,
3117 static __net_init
int sysctl_route_net_init(struct net
*net
)
3119 struct ctl_table
*tbl
;
3121 tbl
= ipv4_route_flush_table
;
3122 if (!net_eq(net
, &init_net
)) {
3123 tbl
= kmemdup(tbl
, sizeof(ipv4_route_flush_table
), GFP_KERNEL
);
3127 tbl
[0].extra1
= net
;
3129 net
->ipv4
.route_hdr
= register_net_sysctl(net
, "net/ipv4/route", tbl
);
3130 if (net
->ipv4
.route_hdr
== NULL
)
3135 if (tbl
!= ipv4_route_flush_table
)
3141 static __net_exit
void sysctl_route_net_exit(struct net
*net
)
3143 struct ctl_table
*tbl
;
3145 tbl
= net
->ipv4
.route_hdr
->ctl_table_arg
;
3146 unregister_net_sysctl_table(net
->ipv4
.route_hdr
);
3147 BUG_ON(tbl
== ipv4_route_flush_table
);
3151 static __net_initdata
struct pernet_operations sysctl_route_ops
= {
3152 .init
= sysctl_route_net_init
,
3153 .exit
= sysctl_route_net_exit
,
3157 static __net_init
int rt_genid_init(struct net
*net
)
3159 get_random_bytes(&net
->ipv4
.rt_genid
,
3160 sizeof(net
->ipv4
.rt_genid
));
3161 get_random_bytes(&net
->ipv4
.dev_addr_genid
,
3162 sizeof(net
->ipv4
.dev_addr_genid
));
3166 static __net_initdata
struct pernet_operations rt_genid_ops
= {
3167 .init
= rt_genid_init
,
3170 static int __net_init
ipv4_inetpeer_init(struct net
*net
)
3172 struct inet_peer_base
*bp
= kmalloc(sizeof(*bp
), GFP_KERNEL
);
3176 inet_peer_base_init(bp
);
3177 net
->ipv4
.peers
= bp
;
3181 static void __net_exit
ipv4_inetpeer_exit(struct net
*net
)
3183 struct inet_peer_base
*bp
= net
->ipv4
.peers
;
3185 net
->ipv4
.peers
= NULL
;
3186 inetpeer_invalidate_tree(bp
);
3190 static __net_initdata
struct pernet_operations ipv4_inetpeer_ops
= {
3191 .init
= ipv4_inetpeer_init
,
3192 .exit
= ipv4_inetpeer_exit
,
3195 #ifdef CONFIG_IP_ROUTE_CLASSID
3196 struct ip_rt_acct __percpu
*ip_rt_acct __read_mostly
;
3197 #endif /* CONFIG_IP_ROUTE_CLASSID */
3199 static __initdata
unsigned long rhash_entries
;
3200 static int __init
set_rhash_entries(char *str
)
3207 ret
= kstrtoul(str
, 0, &rhash_entries
);
3213 __setup("rhash_entries=", set_rhash_entries
);
3215 int __init
ip_rt_init(void)
3219 #ifdef CONFIG_IP_ROUTE_CLASSID
3220 ip_rt_acct
= __alloc_percpu(256 * sizeof(struct ip_rt_acct
), __alignof__(struct ip_rt_acct
));
3222 panic("IP: failed to allocate ip_rt_acct\n");
3225 ipv4_dst_ops
.kmem_cachep
=
3226 kmem_cache_create("ip_dst_cache", sizeof(struct rtable
), 0,
3227 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3229 ipv4_dst_blackhole_ops
.kmem_cachep
= ipv4_dst_ops
.kmem_cachep
;
3231 if (dst_entries_init(&ipv4_dst_ops
) < 0)
3232 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3234 if (dst_entries_init(&ipv4_dst_blackhole_ops
) < 0)
3235 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3237 rt_hash_table
= (struct rt_hash_bucket
*)
3238 alloc_large_system_hash("IP route cache",
3239 sizeof(struct rt_hash_bucket
),
3241 (totalram_pages
>= 128 * 1024) ?
3247 rhash_entries
? 0 : 512 * 1024);
3248 memset(rt_hash_table
, 0, (rt_hash_mask
+ 1) * sizeof(struct rt_hash_bucket
));
3249 rt_hash_lock_init();
3251 ipv4_dst_ops
.gc_thresh
= (rt_hash_mask
+ 1);
3252 ip_rt_max_size
= (rt_hash_mask
+ 1) * 16;
3257 INIT_DELAYED_WORK_DEFERRABLE(&expires_work
, rt_worker_func
);
3258 expires_ljiffies
= jiffies
;
3259 schedule_delayed_work(&expires_work
,
3260 net_random() % ip_rt_gc_interval
+ ip_rt_gc_interval
);
3262 if (ip_rt_proc_init())
3263 pr_err("Unable to create route proc files\n");
3266 xfrm4_init(ip_rt_max_size
);
3268 rtnl_register(PF_INET
, RTM_GETROUTE
, inet_rtm_getroute
, NULL
, NULL
);
3270 #ifdef CONFIG_SYSCTL
3271 register_pernet_subsys(&sysctl_route_ops
);
3273 register_pernet_subsys(&rt_genid_ops
);
3274 register_pernet_subsys(&ipv4_inetpeer_ops
);
3278 #ifdef CONFIG_SYSCTL
3280 * We really need to sanitize the damn ipv4 init order, then all
3281 * this nonsense will go away.
3283 void __init
ip_static_sysctl_init(void)
3285 register_net_sysctl(&init_net
, "net/ipv4/route", ipv4_route_table
);