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
, struct sock
*sk
,
152 struct sk_buff
*skb
, u32 mtu
);
153 static void ip_do_redirect(struct dst_entry
*dst
, struct sock
*sk
,
154 struct sk_buff
*skb
);
155 static int rt_garbage_collect(struct dst_ops
*ops
);
157 static void ipv4_dst_ifdown(struct dst_entry
*dst
, struct net_device
*dev
,
162 static u32
*ipv4_cow_metrics(struct dst_entry
*dst
, unsigned long old
)
168 static struct neighbour
*ipv4_neigh_lookup(const struct dst_entry
*dst
,
172 static struct dst_ops ipv4_dst_ops
= {
174 .protocol
= cpu_to_be16(ETH_P_IP
),
175 .gc
= rt_garbage_collect
,
176 .check
= ipv4_dst_check
,
177 .default_advmss
= ipv4_default_advmss
,
179 .cow_metrics
= ipv4_cow_metrics
,
180 .destroy
= ipv4_dst_destroy
,
181 .ifdown
= ipv4_dst_ifdown
,
182 .negative_advice
= ipv4_negative_advice
,
183 .link_failure
= ipv4_link_failure
,
184 .update_pmtu
= ip_rt_update_pmtu
,
185 .redirect
= ip_do_redirect
,
186 .local_out
= __ip_local_out
,
187 .neigh_lookup
= ipv4_neigh_lookup
,
190 #define ECN_OR_COST(class) TC_PRIO_##class
192 const __u8 ip_tos2prio
[16] = {
194 ECN_OR_COST(BESTEFFORT
),
196 ECN_OR_COST(BESTEFFORT
),
202 ECN_OR_COST(INTERACTIVE
),
204 ECN_OR_COST(INTERACTIVE
),
205 TC_PRIO_INTERACTIVE_BULK
,
206 ECN_OR_COST(INTERACTIVE_BULK
),
207 TC_PRIO_INTERACTIVE_BULK
,
208 ECN_OR_COST(INTERACTIVE_BULK
)
210 EXPORT_SYMBOL(ip_tos2prio
);
216 /* The locking scheme is rather straight forward:
218 * 1) Read-Copy Update protects the buckets of the central route hash.
219 * 2) Only writers remove entries, and they hold the lock
220 * as they look at rtable reference counts.
221 * 3) Only readers acquire references to rtable entries,
222 * they do so with atomic increments and with the
226 struct rt_hash_bucket
{
227 struct rtable __rcu
*chain
;
230 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
231 defined(CONFIG_PROVE_LOCKING)
233 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
234 * The size of this table is a power of two and depends on the number of CPUS.
235 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
237 #ifdef CONFIG_LOCKDEP
238 # define RT_HASH_LOCK_SZ 256
241 # define RT_HASH_LOCK_SZ 4096
243 # define RT_HASH_LOCK_SZ 2048
245 # define RT_HASH_LOCK_SZ 1024
247 # define RT_HASH_LOCK_SZ 512
249 # define RT_HASH_LOCK_SZ 256
253 static spinlock_t
*rt_hash_locks
;
254 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
256 static __init
void rt_hash_lock_init(void)
260 rt_hash_locks
= kmalloc(sizeof(spinlock_t
) * RT_HASH_LOCK_SZ
,
263 panic("IP: failed to allocate rt_hash_locks\n");
265 for (i
= 0; i
< RT_HASH_LOCK_SZ
; i
++)
266 spin_lock_init(&rt_hash_locks
[i
]);
269 # define rt_hash_lock_addr(slot) NULL
271 static inline void rt_hash_lock_init(void)
276 static struct rt_hash_bucket
*rt_hash_table __read_mostly
;
277 static unsigned int rt_hash_mask __read_mostly
;
278 static unsigned int rt_hash_log __read_mostly
;
280 static DEFINE_PER_CPU(struct rt_cache_stat
, rt_cache_stat
);
281 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
283 static inline unsigned int rt_hash(__be32 daddr
, __be32 saddr
, int idx
,
286 return jhash_3words((__force u32
)daddr
, (__force u32
)saddr
,
291 static inline int rt_genid(struct net
*net
)
293 return atomic_read(&net
->ipv4
.rt_genid
);
296 #ifdef CONFIG_PROC_FS
297 struct rt_cache_iter_state
{
298 struct seq_net_private p
;
303 static struct rtable
*rt_cache_get_first(struct seq_file
*seq
)
305 struct rt_cache_iter_state
*st
= seq
->private;
306 struct rtable
*r
= NULL
;
308 for (st
->bucket
= rt_hash_mask
; st
->bucket
>= 0; --st
->bucket
) {
309 if (!rcu_access_pointer(rt_hash_table
[st
->bucket
].chain
))
312 r
= rcu_dereference_bh(rt_hash_table
[st
->bucket
].chain
);
314 if (dev_net(r
->dst
.dev
) == seq_file_net(seq
) &&
315 r
->rt_genid
== st
->genid
)
317 r
= rcu_dereference_bh(r
->dst
.rt_next
);
319 rcu_read_unlock_bh();
324 static struct rtable
*__rt_cache_get_next(struct seq_file
*seq
,
327 struct rt_cache_iter_state
*st
= seq
->private;
329 r
= rcu_dereference_bh(r
->dst
.rt_next
);
331 rcu_read_unlock_bh();
333 if (--st
->bucket
< 0)
335 } while (!rcu_access_pointer(rt_hash_table
[st
->bucket
].chain
));
337 r
= rcu_dereference_bh(rt_hash_table
[st
->bucket
].chain
);
342 static struct rtable
*rt_cache_get_next(struct seq_file
*seq
,
345 struct rt_cache_iter_state
*st
= seq
->private;
346 while ((r
= __rt_cache_get_next(seq
, r
)) != NULL
) {
347 if (dev_net(r
->dst
.dev
) != seq_file_net(seq
))
349 if (r
->rt_genid
== st
->genid
)
355 static struct rtable
*rt_cache_get_idx(struct seq_file
*seq
, loff_t pos
)
357 struct rtable
*r
= rt_cache_get_first(seq
);
360 while (pos
&& (r
= rt_cache_get_next(seq
, r
)))
362 return pos
? NULL
: r
;
365 static void *rt_cache_seq_start(struct seq_file
*seq
, loff_t
*pos
)
367 struct rt_cache_iter_state
*st
= seq
->private;
369 return rt_cache_get_idx(seq
, *pos
- 1);
370 st
->genid
= rt_genid(seq_file_net(seq
));
371 return SEQ_START_TOKEN
;
374 static void *rt_cache_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
378 if (v
== SEQ_START_TOKEN
)
379 r
= rt_cache_get_first(seq
);
381 r
= rt_cache_get_next(seq
, v
);
386 static void rt_cache_seq_stop(struct seq_file
*seq
, void *v
)
388 if (v
&& v
!= SEQ_START_TOKEN
)
389 rcu_read_unlock_bh();
392 static int rt_cache_seq_show(struct seq_file
*seq
, void *v
)
394 if (v
== SEQ_START_TOKEN
)
395 seq_printf(seq
, "%-127s\n",
396 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
397 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
400 struct rtable
*r
= v
;
403 seq_printf(seq
, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
404 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
405 r
->dst
.dev
? r
->dst
.dev
->name
: "*",
406 (__force u32
)r
->rt_dst
,
407 (__force u32
)r
->rt_gateway
,
408 r
->rt_flags
, atomic_read(&r
->dst
.__refcnt
),
409 r
->dst
.__use
, 0, (__force u32
)r
->rt_src
,
410 dst_metric_advmss(&r
->dst
) + 40,
411 dst_metric(&r
->dst
, RTAX_WINDOW
), 0,
415 seq_printf(seq
, "%*s\n", 127 - len
, "");
420 static const struct seq_operations rt_cache_seq_ops
= {
421 .start
= rt_cache_seq_start
,
422 .next
= rt_cache_seq_next
,
423 .stop
= rt_cache_seq_stop
,
424 .show
= rt_cache_seq_show
,
427 static int rt_cache_seq_open(struct inode
*inode
, struct file
*file
)
429 return seq_open_net(inode
, file
, &rt_cache_seq_ops
,
430 sizeof(struct rt_cache_iter_state
));
433 static const struct file_operations rt_cache_seq_fops
= {
434 .owner
= THIS_MODULE
,
435 .open
= rt_cache_seq_open
,
438 .release
= seq_release_net
,
442 static void *rt_cpu_seq_start(struct seq_file
*seq
, loff_t
*pos
)
447 return SEQ_START_TOKEN
;
449 for (cpu
= *pos
-1; cpu
< nr_cpu_ids
; ++cpu
) {
450 if (!cpu_possible(cpu
))
453 return &per_cpu(rt_cache_stat
, cpu
);
458 static void *rt_cpu_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
462 for (cpu
= *pos
; cpu
< nr_cpu_ids
; ++cpu
) {
463 if (!cpu_possible(cpu
))
466 return &per_cpu(rt_cache_stat
, cpu
);
472 static void rt_cpu_seq_stop(struct seq_file
*seq
, void *v
)
477 static int rt_cpu_seq_show(struct seq_file
*seq
, void *v
)
479 struct rt_cache_stat
*st
= v
;
481 if (v
== SEQ_START_TOKEN
) {
482 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");
486 seq_printf(seq
,"%08x %08x %08x %08x %08x %08x %08x %08x "
487 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
488 dst_entries_get_slow(&ipv4_dst_ops
),
511 static const struct seq_operations rt_cpu_seq_ops
= {
512 .start
= rt_cpu_seq_start
,
513 .next
= rt_cpu_seq_next
,
514 .stop
= rt_cpu_seq_stop
,
515 .show
= rt_cpu_seq_show
,
519 static int rt_cpu_seq_open(struct inode
*inode
, struct file
*file
)
521 return seq_open(file
, &rt_cpu_seq_ops
);
524 static const struct file_operations rt_cpu_seq_fops
= {
525 .owner
= THIS_MODULE
,
526 .open
= rt_cpu_seq_open
,
529 .release
= seq_release
,
532 #ifdef CONFIG_IP_ROUTE_CLASSID
533 static int rt_acct_proc_show(struct seq_file
*m
, void *v
)
535 struct ip_rt_acct
*dst
, *src
;
538 dst
= kcalloc(256, sizeof(struct ip_rt_acct
), GFP_KERNEL
);
542 for_each_possible_cpu(i
) {
543 src
= (struct ip_rt_acct
*)per_cpu_ptr(ip_rt_acct
, i
);
544 for (j
= 0; j
< 256; j
++) {
545 dst
[j
].o_bytes
+= src
[j
].o_bytes
;
546 dst
[j
].o_packets
+= src
[j
].o_packets
;
547 dst
[j
].i_bytes
+= src
[j
].i_bytes
;
548 dst
[j
].i_packets
+= src
[j
].i_packets
;
552 seq_write(m
, dst
, 256 * sizeof(struct ip_rt_acct
));
557 static int rt_acct_proc_open(struct inode
*inode
, struct file
*file
)
559 return single_open(file
, rt_acct_proc_show
, NULL
);
562 static const struct file_operations rt_acct_proc_fops
= {
563 .owner
= THIS_MODULE
,
564 .open
= rt_acct_proc_open
,
567 .release
= single_release
,
571 static int __net_init
ip_rt_do_proc_init(struct net
*net
)
573 struct proc_dir_entry
*pde
;
575 pde
= proc_net_fops_create(net
, "rt_cache", S_IRUGO
,
580 pde
= proc_create("rt_cache", S_IRUGO
,
581 net
->proc_net_stat
, &rt_cpu_seq_fops
);
585 #ifdef CONFIG_IP_ROUTE_CLASSID
586 pde
= proc_create("rt_acct", 0, net
->proc_net
, &rt_acct_proc_fops
);
592 #ifdef CONFIG_IP_ROUTE_CLASSID
594 remove_proc_entry("rt_cache", net
->proc_net_stat
);
597 remove_proc_entry("rt_cache", net
->proc_net
);
602 static void __net_exit
ip_rt_do_proc_exit(struct net
*net
)
604 remove_proc_entry("rt_cache", net
->proc_net_stat
);
605 remove_proc_entry("rt_cache", net
->proc_net
);
606 #ifdef CONFIG_IP_ROUTE_CLASSID
607 remove_proc_entry("rt_acct", net
->proc_net
);
611 static struct pernet_operations ip_rt_proc_ops __net_initdata
= {
612 .init
= ip_rt_do_proc_init
,
613 .exit
= ip_rt_do_proc_exit
,
616 static int __init
ip_rt_proc_init(void)
618 return register_pernet_subsys(&ip_rt_proc_ops
);
622 static inline int ip_rt_proc_init(void)
626 #endif /* CONFIG_PROC_FS */
628 static inline void rt_free(struct rtable
*rt
)
630 call_rcu_bh(&rt
->dst
.rcu_head
, dst_rcu_free
);
633 static inline void rt_drop(struct rtable
*rt
)
636 call_rcu_bh(&rt
->dst
.rcu_head
, dst_rcu_free
);
639 static inline int rt_fast_clean(struct rtable
*rth
)
641 /* Kill broadcast/multicast entries very aggresively, if they
642 collide in hash table with more useful entries */
643 return (rth
->rt_flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) &&
644 rt_is_input_route(rth
) && rth
->dst
.rt_next
;
647 static inline int rt_valuable(struct rtable
*rth
)
649 return (rth
->rt_flags
& (RTCF_REDIRECTED
| RTCF_NOTIFY
)) ||
653 static int rt_may_expire(struct rtable
*rth
, unsigned long tmo1
, unsigned long tmo2
)
658 if (atomic_read(&rth
->dst
.__refcnt
))
661 age
= jiffies
- rth
->dst
.lastuse
;
662 if ((age
<= tmo1
&& !rt_fast_clean(rth
)) ||
663 (age
<= tmo2
&& rt_valuable(rth
)))
669 /* Bits of score are:
671 * 30: not quite useless
672 * 29..0: usage counter
674 static inline u32
rt_score(struct rtable
*rt
)
676 u32 score
= jiffies
- rt
->dst
.lastuse
;
678 score
= ~score
& ~(3<<30);
683 if (rt_is_output_route(rt
) ||
684 !(rt
->rt_flags
& (RTCF_BROADCAST
|RTCF_MULTICAST
|RTCF_LOCAL
)))
690 static inline bool rt_caching(const struct net
*net
)
692 return net
->ipv4
.current_rt_cache_rebuild_count
<=
693 net
->ipv4
.sysctl_rt_cache_rebuild_count
;
696 static inline bool compare_hash_inputs(const struct rtable
*rt1
,
697 const struct rtable
*rt2
)
699 return ((((__force u32
)rt1
->rt_key_dst
^ (__force u32
)rt2
->rt_key_dst
) |
700 ((__force u32
)rt1
->rt_key_src
^ (__force u32
)rt2
->rt_key_src
) |
701 (rt1
->rt_route_iif
^ rt2
->rt_route_iif
)) == 0);
704 static inline int compare_keys(struct rtable
*rt1
, struct rtable
*rt2
)
706 return (((__force u32
)rt1
->rt_key_dst
^ (__force u32
)rt2
->rt_key_dst
) |
707 ((__force u32
)rt1
->rt_key_src
^ (__force u32
)rt2
->rt_key_src
) |
708 (rt1
->rt_mark
^ rt2
->rt_mark
) |
709 (rt1
->rt_key_tos
^ rt2
->rt_key_tos
) |
710 (rt1
->rt_route_iif
^ rt2
->rt_route_iif
) |
711 (rt1
->rt_oif
^ rt2
->rt_oif
)) == 0;
714 static inline int compare_netns(struct rtable
*rt1
, struct rtable
*rt2
)
716 return net_eq(dev_net(rt1
->dst
.dev
), dev_net(rt2
->dst
.dev
));
719 static inline int rt_is_expired(struct rtable
*rth
)
721 return rth
->rt_genid
!= rt_genid(dev_net(rth
->dst
.dev
));
725 * Perform a full scan of hash table and free all entries.
726 * Can be called by a softirq or a process.
727 * In the later case, we want to be reschedule if necessary
729 static void rt_do_flush(struct net
*net
, int process_context
)
732 struct rtable
*rth
, *next
;
734 for (i
= 0; i
<= rt_hash_mask
; i
++) {
735 struct rtable __rcu
**pprev
;
738 if (process_context
&& need_resched())
740 rth
= rcu_access_pointer(rt_hash_table
[i
].chain
);
744 spin_lock_bh(rt_hash_lock_addr(i
));
747 pprev
= &rt_hash_table
[i
].chain
;
748 rth
= rcu_dereference_protected(*pprev
,
749 lockdep_is_held(rt_hash_lock_addr(i
)));
752 next
= rcu_dereference_protected(rth
->dst
.rt_next
,
753 lockdep_is_held(rt_hash_lock_addr(i
)));
756 net_eq(dev_net(rth
->dst
.dev
), net
)) {
757 rcu_assign_pointer(*pprev
, next
);
758 rcu_assign_pointer(rth
->dst
.rt_next
, list
);
761 pprev
= &rth
->dst
.rt_next
;
766 spin_unlock_bh(rt_hash_lock_addr(i
));
768 for (; list
; list
= next
) {
769 next
= rcu_dereference_protected(list
->dst
.rt_next
, 1);
776 * While freeing expired entries, we compute average chain length
777 * and standard deviation, using fixed-point arithmetic.
778 * This to have an estimation of rt_chain_length_max
779 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
780 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
784 #define ONE (1UL << FRACT_BITS)
787 * Given a hash chain and an item in this hash chain,
788 * find if a previous entry has the same hash_inputs
789 * (but differs on tos, mark or oif)
790 * Returns 0 if an alias is found.
791 * Returns ONE if rth has no alias before itself.
793 static int has_noalias(const struct rtable
*head
, const struct rtable
*rth
)
795 const struct rtable
*aux
= head
;
798 if (compare_hash_inputs(aux
, rth
))
800 aux
= rcu_dereference_protected(aux
->dst
.rt_next
, 1);
805 static void rt_check_expire(void)
807 static unsigned int rover
;
808 unsigned int i
= rover
, goal
;
810 struct rtable __rcu
**rthp
;
811 unsigned long samples
= 0;
812 unsigned long sum
= 0, sum2
= 0;
816 delta
= jiffies
- expires_ljiffies
;
817 expires_ljiffies
= jiffies
;
818 mult
= ((u64
)delta
) << rt_hash_log
;
819 if (ip_rt_gc_timeout
> 1)
820 do_div(mult
, ip_rt_gc_timeout
);
821 goal
= (unsigned int)mult
;
822 if (goal
> rt_hash_mask
)
823 goal
= rt_hash_mask
+ 1;
824 for (; goal
> 0; goal
--) {
825 unsigned long tmo
= ip_rt_gc_timeout
;
826 unsigned long length
;
828 i
= (i
+ 1) & rt_hash_mask
;
829 rthp
= &rt_hash_table
[i
].chain
;
836 if (rcu_dereference_raw(*rthp
) == NULL
)
839 spin_lock_bh(rt_hash_lock_addr(i
));
840 while ((rth
= rcu_dereference_protected(*rthp
,
841 lockdep_is_held(rt_hash_lock_addr(i
)))) != NULL
) {
842 prefetch(rth
->dst
.rt_next
);
843 if (rt_is_expired(rth
) ||
844 rt_may_expire(rth
, tmo
, ip_rt_gc_timeout
)) {
845 *rthp
= rth
->dst
.rt_next
;
850 /* We only count entries on a chain with equal
851 * hash inputs once so that entries for
852 * different QOS levels, and other non-hash
853 * input attributes don't unfairly skew the
857 rthp
= &rth
->dst
.rt_next
;
858 length
+= has_noalias(rt_hash_table
[i
].chain
, rth
);
860 spin_unlock_bh(rt_hash_lock_addr(i
));
862 sum2
+= length
*length
;
865 unsigned long avg
= sum
/ samples
;
866 unsigned long sd
= int_sqrt(sum2
/ samples
- avg
*avg
);
867 rt_chain_length_max
= max_t(unsigned long,
869 (avg
+ 4*sd
) >> FRACT_BITS
);
875 * rt_worker_func() is run in process context.
876 * we call rt_check_expire() to scan part of the hash table
878 static void rt_worker_func(struct work_struct
*work
)
881 schedule_delayed_work(&expires_work
, ip_rt_gc_interval
);
885 * Perturbation of rt_genid by a small quantity [1..256]
886 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
887 * many times (2^24) without giving recent rt_genid.
888 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
890 static void rt_cache_invalidate(struct net
*net
)
892 unsigned char shuffle
;
894 get_random_bytes(&shuffle
, sizeof(shuffle
));
895 atomic_add(shuffle
+ 1U, &net
->ipv4
.rt_genid
);
899 * delay < 0 : invalidate cache (fast : entries will be deleted later)
900 * delay >= 0 : invalidate & flush cache (can be long)
902 void rt_cache_flush(struct net
*net
, int delay
)
904 rt_cache_invalidate(net
);
906 rt_do_flush(net
, !in_softirq());
909 /* Flush previous cache invalidated entries from the cache */
910 void rt_cache_flush_batch(struct net
*net
)
912 rt_do_flush(net
, !in_softirq());
915 static void rt_emergency_hash_rebuild(struct net
*net
)
917 net_warn_ratelimited("Route hash chain too long!\n");
918 rt_cache_invalidate(net
);
922 Short description of GC goals.
924 We want to build algorithm, which will keep routing cache
925 at some equilibrium point, when number of aged off entries
926 is kept approximately equal to newly generated ones.
928 Current expiration strength is variable "expire".
929 We try to adjust it dynamically, so that if networking
930 is idle expires is large enough to keep enough of warm entries,
931 and when load increases it reduces to limit cache size.
934 static int rt_garbage_collect(struct dst_ops
*ops
)
936 static unsigned long expire
= RT_GC_TIMEOUT
;
937 static unsigned long last_gc
;
939 static int equilibrium
;
941 struct rtable __rcu
**rthp
;
942 unsigned long now
= jiffies
;
944 int entries
= dst_entries_get_fast(&ipv4_dst_ops
);
947 * Garbage collection is pretty expensive,
948 * do not make it too frequently.
951 RT_CACHE_STAT_INC(gc_total
);
953 if (now
- last_gc
< ip_rt_gc_min_interval
&&
954 entries
< ip_rt_max_size
) {
955 RT_CACHE_STAT_INC(gc_ignored
);
959 entries
= dst_entries_get_slow(&ipv4_dst_ops
);
960 /* Calculate number of entries, which we want to expire now. */
961 goal
= entries
- (ip_rt_gc_elasticity
<< rt_hash_log
);
963 if (equilibrium
< ipv4_dst_ops
.gc_thresh
)
964 equilibrium
= ipv4_dst_ops
.gc_thresh
;
965 goal
= entries
- equilibrium
;
967 equilibrium
+= min_t(unsigned int, goal
>> 1, rt_hash_mask
+ 1);
968 goal
= entries
- equilibrium
;
971 /* We are in dangerous area. Try to reduce cache really
974 goal
= max_t(unsigned int, goal
>> 1, rt_hash_mask
+ 1);
975 equilibrium
= entries
- goal
;
978 if (now
- last_gc
>= ip_rt_gc_min_interval
)
989 for (i
= rt_hash_mask
, k
= rover
; i
>= 0; i
--) {
990 unsigned long tmo
= expire
;
992 k
= (k
+ 1) & rt_hash_mask
;
993 rthp
= &rt_hash_table
[k
].chain
;
994 spin_lock_bh(rt_hash_lock_addr(k
));
995 while ((rth
= rcu_dereference_protected(*rthp
,
996 lockdep_is_held(rt_hash_lock_addr(k
)))) != NULL
) {
997 if (!rt_is_expired(rth
) &&
998 !rt_may_expire(rth
, tmo
, expire
)) {
1000 rthp
= &rth
->dst
.rt_next
;
1003 *rthp
= rth
->dst
.rt_next
;
1007 spin_unlock_bh(rt_hash_lock_addr(k
));
1016 /* Goal is not achieved. We stop process if:
1018 - if expire reduced to zero. Otherwise, expire is halfed.
1019 - if table is not full.
1020 - if we are called from interrupt.
1021 - jiffies check is just fallback/debug loop breaker.
1022 We will not spin here for long time in any case.
1025 RT_CACHE_STAT_INC(gc_goal_miss
);
1032 if (dst_entries_get_fast(&ipv4_dst_ops
) < ip_rt_max_size
)
1034 } while (!in_softirq() && time_before_eq(jiffies
, now
));
1036 if (dst_entries_get_fast(&ipv4_dst_ops
) < ip_rt_max_size
)
1038 if (dst_entries_get_slow(&ipv4_dst_ops
) < ip_rt_max_size
)
1040 net_warn_ratelimited("dst cache overflow\n");
1041 RT_CACHE_STAT_INC(gc_dst_overflow
);
1045 expire
+= ip_rt_gc_min_interval
;
1046 if (expire
> ip_rt_gc_timeout
||
1047 dst_entries_get_fast(&ipv4_dst_ops
) < ipv4_dst_ops
.gc_thresh
||
1048 dst_entries_get_slow(&ipv4_dst_ops
) < ipv4_dst_ops
.gc_thresh
)
1049 expire
= ip_rt_gc_timeout
;
1054 * Returns number of entries in a hash chain that have different hash_inputs
1056 static int slow_chain_length(const struct rtable
*head
)
1059 const struct rtable
*rth
= head
;
1062 length
+= has_noalias(head
, rth
);
1063 rth
= rcu_dereference_protected(rth
->dst
.rt_next
, 1);
1065 return length
>> FRACT_BITS
;
1068 static struct neighbour
*ipv4_neigh_lookup(const struct dst_entry
*dst
,
1069 struct sk_buff
*skb
,
1072 struct net_device
*dev
= dst
->dev
;
1073 const __be32
*pkey
= daddr
;
1074 const struct rtable
*rt
;
1075 struct neighbour
*n
;
1077 rt
= (const struct rtable
*) dst
;
1079 pkey
= (const __be32
*) &rt
->rt_gateway
;
1081 pkey
= &ip_hdr(skb
)->daddr
;
1083 n
= __ipv4_neigh_lookup(dev
, *(__force u32
*)pkey
);
1086 return neigh_create(&arp_tbl
, pkey
, dev
);
1089 static struct rtable
*rt_intern_hash(unsigned int hash
, struct rtable
*rt
,
1090 struct sk_buff
*skb
, int ifindex
)
1092 struct rtable
*rth
, *cand
;
1093 struct rtable __rcu
**rthp
, **candp
;
1100 min_score
= ~(u32
)0;
1105 if (!rt_caching(dev_net(rt
->dst
.dev
)) || (rt
->dst
.flags
& DST_NOCACHE
)) {
1107 * If we're not caching, just tell the caller we
1108 * were successful and don't touch the route. The
1109 * caller hold the sole reference to the cache entry, and
1110 * it will be released when the caller is done with it.
1111 * If we drop it here, the callers have no way to resolve routes
1112 * when we're not caching. Instead, just point *rp at rt, so
1113 * the caller gets a single use out of the route
1114 * Note that we do rt_free on this new route entry, so that
1115 * once its refcount hits zero, we are still able to reap it
1117 * Note: To avoid expensive rcu stuff for this uncached dst,
1118 * we set DST_NOCACHE so that dst_release() can free dst without
1119 * waiting a grace period.
1122 rt
->dst
.flags
|= DST_NOCACHE
;
1126 rthp
= &rt_hash_table
[hash
].chain
;
1128 spin_lock_bh(rt_hash_lock_addr(hash
));
1129 while ((rth
= rcu_dereference_protected(*rthp
,
1130 lockdep_is_held(rt_hash_lock_addr(hash
)))) != NULL
) {
1131 if (rt_is_expired(rth
)) {
1132 *rthp
= rth
->dst
.rt_next
;
1136 if (compare_keys(rth
, rt
) && compare_netns(rth
, rt
)) {
1138 *rthp
= rth
->dst
.rt_next
;
1140 * Since lookup is lockfree, the deletion
1141 * must be visible to another weakly ordered CPU before
1142 * the insertion at the start of the hash chain.
1144 rcu_assign_pointer(rth
->dst
.rt_next
,
1145 rt_hash_table
[hash
].chain
);
1147 * Since lookup is lockfree, the update writes
1148 * must be ordered for consistency on SMP.
1150 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rth
);
1152 dst_use(&rth
->dst
, now
);
1153 spin_unlock_bh(rt_hash_lock_addr(hash
));
1157 skb_dst_set(skb
, &rth
->dst
);
1161 if (!atomic_read(&rth
->dst
.__refcnt
)) {
1162 u32 score
= rt_score(rth
);
1164 if (score
<= min_score
) {
1173 rthp
= &rth
->dst
.rt_next
;
1177 /* ip_rt_gc_elasticity used to be average length of chain
1178 * length, when exceeded gc becomes really aggressive.
1180 * The second limit is less certain. At the moment it allows
1181 * only 2 entries per bucket. We will see.
1183 if (chain_length
> ip_rt_gc_elasticity
) {
1184 *candp
= cand
->dst
.rt_next
;
1188 if (chain_length
> rt_chain_length_max
&&
1189 slow_chain_length(rt_hash_table
[hash
].chain
) > rt_chain_length_max
) {
1190 struct net
*net
= dev_net(rt
->dst
.dev
);
1191 int num
= ++net
->ipv4
.current_rt_cache_rebuild_count
;
1192 if (!rt_caching(net
)) {
1193 pr_warn("%s: %d rebuilds is over limit, route caching disabled\n",
1194 rt
->dst
.dev
->name
, num
);
1196 rt_emergency_hash_rebuild(net
);
1197 spin_unlock_bh(rt_hash_lock_addr(hash
));
1199 hash
= rt_hash(rt
->rt_key_dst
, rt
->rt_key_src
,
1200 ifindex
, rt_genid(net
));
1205 rt
->dst
.rt_next
= rt_hash_table
[hash
].chain
;
1208 * Since lookup is lockfree, we must make sure
1209 * previous writes to rt are committed to memory
1210 * before making rt visible to other CPUS.
1212 rcu_assign_pointer(rt_hash_table
[hash
].chain
, rt
);
1214 spin_unlock_bh(rt_hash_lock_addr(hash
));
1218 skb_dst_set(skb
, &rt
->dst
);
1223 * Peer allocation may fail only in serious out-of-memory conditions. However
1224 * we still can generate some output.
1225 * Random ID selection looks a bit dangerous because we have no chances to
1226 * select ID being unique in a reasonable period of time.
1227 * But broken packet identifier may be better than no packet at all.
1229 static void ip_select_fb_ident(struct iphdr
*iph
)
1231 static DEFINE_SPINLOCK(ip_fb_id_lock
);
1232 static u32 ip_fallback_id
;
1235 spin_lock_bh(&ip_fb_id_lock
);
1236 salt
= secure_ip_id((__force __be32
)ip_fallback_id
^ iph
->daddr
);
1237 iph
->id
= htons(salt
& 0xFFFF);
1238 ip_fallback_id
= salt
;
1239 spin_unlock_bh(&ip_fb_id_lock
);
1242 void __ip_select_ident(struct iphdr
*iph
, struct dst_entry
*dst
, int more
)
1244 struct net
*net
= dev_net(dst
->dev
);
1245 struct inet_peer
*peer
;
1247 peer
= inet_getpeer_v4(net
->ipv4
.peers
, iph
->daddr
, 1);
1249 iph
->id
= htons(inet_getid(peer
, more
));
1254 ip_select_fb_ident(iph
);
1256 EXPORT_SYMBOL(__ip_select_ident
);
1258 static void rt_del(unsigned int hash
, struct rtable
*rt
)
1260 struct rtable __rcu
**rthp
;
1263 rthp
= &rt_hash_table
[hash
].chain
;
1264 spin_lock_bh(rt_hash_lock_addr(hash
));
1266 while ((aux
= rcu_dereference_protected(*rthp
,
1267 lockdep_is_held(rt_hash_lock_addr(hash
)))) != NULL
) {
1268 if (aux
== rt
|| rt_is_expired(aux
)) {
1269 *rthp
= aux
->dst
.rt_next
;
1273 rthp
= &aux
->dst
.rt_next
;
1275 spin_unlock_bh(rt_hash_lock_addr(hash
));
1278 static void __build_flow_key(struct flowi4
*fl4
, struct sock
*sk
,
1279 const struct iphdr
*iph
,
1281 u8 prot
, u32 mark
, int flow_flags
)
1284 const struct inet_sock
*inet
= inet_sk(sk
);
1286 oif
= sk
->sk_bound_dev_if
;
1288 tos
= RT_CONN_FLAGS(sk
);
1289 prot
= inet
->hdrincl
? IPPROTO_RAW
: sk
->sk_protocol
;
1291 flowi4_init_output(fl4
, oif
, mark
, tos
,
1292 RT_SCOPE_UNIVERSE
, prot
,
1294 iph
->daddr
, iph
->saddr
, 0, 0);
1297 static void build_skb_flow_key(struct flowi4
*fl4
, struct sk_buff
*skb
, struct sock
*sk
)
1299 const struct iphdr
*iph
= ip_hdr(skb
);
1300 int oif
= skb
->dev
->ifindex
;
1301 u8 tos
= RT_TOS(iph
->tos
);
1302 u8 prot
= iph
->protocol
;
1303 u32 mark
= skb
->mark
;
1305 __build_flow_key(fl4
, sk
, iph
, oif
, tos
, prot
, mark
, 0);
1308 static void build_sk_flow_key(struct flowi4
*fl4
, struct sock
*sk
)
1310 const struct inet_sock
*inet
= inet_sk(sk
);
1311 struct ip_options_rcu
*inet_opt
;
1312 __be32 daddr
= inet
->inet_daddr
;
1315 inet_opt
= rcu_dereference(inet
->inet_opt
);
1316 if (inet_opt
&& inet_opt
->opt
.srr
)
1317 daddr
= inet_opt
->opt
.faddr
;
1318 flowi4_init_output(fl4
, sk
->sk_bound_dev_if
, sk
->sk_mark
,
1319 RT_CONN_FLAGS(sk
), RT_SCOPE_UNIVERSE
,
1320 inet
->hdrincl
? IPPROTO_RAW
: sk
->sk_protocol
,
1321 inet_sk_flowi_flags(sk
),
1322 daddr
, inet
->inet_saddr
, 0, 0);
1326 static void ip_rt_build_flow_key(struct flowi4
*fl4
, struct sock
*sk
,
1327 struct sk_buff
*skb
)
1330 build_skb_flow_key(fl4
, skb
, sk
);
1332 build_sk_flow_key(fl4
, sk
);
1335 static DEFINE_SPINLOCK(fnhe_lock
);
1337 static struct fib_nh_exception
*fnhe_oldest(struct fnhe_hash_bucket
*hash
, __be32 daddr
)
1339 struct fib_nh_exception
*fnhe
, *oldest
;
1341 oldest
= rcu_dereference(hash
->chain
);
1342 for (fnhe
= rcu_dereference(oldest
->fnhe_next
); fnhe
;
1343 fnhe
= rcu_dereference(fnhe
->fnhe_next
)) {
1344 if (time_before(fnhe
->fnhe_stamp
, oldest
->fnhe_stamp
))
1350 static inline u32
fnhe_hashfun(__be32 daddr
)
1354 hval
= (__force u32
) daddr
;
1355 hval
^= (hval
>> 11) ^ (hval
>> 22);
1357 return hval
& (FNHE_HASH_SIZE
- 1);
1360 static struct fib_nh_exception
*find_or_create_fnhe(struct fib_nh
*nh
, __be32 daddr
)
1362 struct fnhe_hash_bucket
*hash
= nh
->nh_exceptions
;
1363 struct fib_nh_exception
*fnhe
;
1368 hash
= nh
->nh_exceptions
= kzalloc(FNHE_HASH_SIZE
* sizeof(*hash
),
1374 hval
= fnhe_hashfun(daddr
);
1378 for (fnhe
= rcu_dereference(hash
->chain
); fnhe
;
1379 fnhe
= rcu_dereference(fnhe
->fnhe_next
)) {
1380 if (fnhe
->fnhe_daddr
== daddr
)
1385 if (depth
> FNHE_RECLAIM_DEPTH
) {
1386 fnhe
= fnhe_oldest(hash
+ hval
, daddr
);
1389 fnhe
= kzalloc(sizeof(*fnhe
), GFP_ATOMIC
);
1393 fnhe
->fnhe_next
= hash
->chain
;
1394 rcu_assign_pointer(hash
->chain
, fnhe
);
1397 fnhe
->fnhe_daddr
= daddr
;
1399 fnhe
->fnhe_stamp
= jiffies
;
1403 static void __ip_do_redirect(struct rtable
*rt
, struct sk_buff
*skb
, struct flowi4
*fl4
)
1405 __be32 new_gw
= icmp_hdr(skb
)->un
.gateway
;
1406 __be32 old_gw
= ip_hdr(skb
)->saddr
;
1407 struct net_device
*dev
= skb
->dev
;
1408 struct in_device
*in_dev
;
1409 struct fib_result res
;
1410 struct neighbour
*n
;
1413 switch (icmp_hdr(skb
)->code
& 7) {
1414 case ICMP_REDIR_NET
:
1415 case ICMP_REDIR_NETTOS
:
1416 case ICMP_REDIR_HOST
:
1417 case ICMP_REDIR_HOSTTOS
:
1424 if (rt
->rt_gateway
!= old_gw
)
1427 in_dev
= __in_dev_get_rcu(dev
);
1432 if (new_gw
== old_gw
|| !IN_DEV_RX_REDIRECTS(in_dev
) ||
1433 ipv4_is_multicast(new_gw
) || ipv4_is_lbcast(new_gw
) ||
1434 ipv4_is_zeronet(new_gw
))
1435 goto reject_redirect
;
1437 if (!IN_DEV_SHARED_MEDIA(in_dev
)) {
1438 if (!inet_addr_onlink(in_dev
, new_gw
, old_gw
))
1439 goto reject_redirect
;
1440 if (IN_DEV_SEC_REDIRECTS(in_dev
) && ip_fib_check_default(new_gw
, dev
))
1441 goto reject_redirect
;
1443 if (inet_addr_type(net
, new_gw
) != RTN_UNICAST
)
1444 goto reject_redirect
;
1447 n
= ipv4_neigh_lookup(&rt
->dst
, NULL
, &new_gw
);
1449 if (!(n
->nud_state
& NUD_VALID
)) {
1450 neigh_event_send(n
, NULL
);
1452 if (fib_lookup(net
, fl4
, &res
) == 0) {
1453 struct fib_nh
*nh
= &FIB_RES_NH(res
);
1454 struct fib_nh_exception
*fnhe
;
1456 spin_lock_bh(&fnhe_lock
);
1457 fnhe
= find_or_create_fnhe(nh
, fl4
->daddr
);
1459 fnhe
->fnhe_gw
= new_gw
;
1460 spin_unlock_bh(&fnhe_lock
);
1462 rt
->rt_gateway
= new_gw
;
1463 rt
->rt_flags
|= RTCF_REDIRECTED
;
1464 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE
, n
);
1471 #ifdef CONFIG_IP_ROUTE_VERBOSE
1472 if (IN_DEV_LOG_MARTIANS(in_dev
)) {
1473 const struct iphdr
*iph
= (const struct iphdr
*) skb
->data
;
1474 __be32 daddr
= iph
->daddr
;
1475 __be32 saddr
= iph
->saddr
;
1477 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
1478 " Advised path = %pI4 -> %pI4\n",
1479 &old_gw
, dev
->name
, &new_gw
,
1486 static void ip_do_redirect(struct dst_entry
*dst
, struct sock
*sk
, struct sk_buff
*skb
)
1491 rt
= (struct rtable
*) dst
;
1493 ip_rt_build_flow_key(&fl4
, sk
, skb
);
1494 __ip_do_redirect(rt
, skb
, &fl4
);
1497 static struct dst_entry
*ipv4_negative_advice(struct dst_entry
*dst
)
1499 struct rtable
*rt
= (struct rtable
*)dst
;
1500 struct dst_entry
*ret
= dst
;
1503 if (dst
->obsolete
> 0) {
1506 } else if ((rt
->rt_flags
& RTCF_REDIRECTED
) ||
1508 unsigned int hash
= rt_hash(rt
->rt_key_dst
, rt
->rt_key_src
,
1510 rt_genid(dev_net(dst
->dev
)));
1520 * 1. The first ip_rt_redirect_number redirects are sent
1521 * with exponential backoff, then we stop sending them at all,
1522 * assuming that the host ignores our redirects.
1523 * 2. If we did not see packets requiring redirects
1524 * during ip_rt_redirect_silence, we assume that the host
1525 * forgot redirected route and start to send redirects again.
1527 * This algorithm is much cheaper and more intelligent than dumb load limiting
1530 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1531 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1534 void ip_rt_send_redirect(struct sk_buff
*skb
)
1536 struct rtable
*rt
= skb_rtable(skb
);
1537 struct in_device
*in_dev
;
1538 struct inet_peer
*peer
;
1543 in_dev
= __in_dev_get_rcu(rt
->dst
.dev
);
1544 if (!in_dev
|| !IN_DEV_TX_REDIRECTS(in_dev
)) {
1548 log_martians
= IN_DEV_LOG_MARTIANS(in_dev
);
1551 net
= dev_net(rt
->dst
.dev
);
1552 peer
= inet_getpeer_v4(net
->ipv4
.peers
, ip_hdr(skb
)->saddr
, 1);
1554 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, rt
->rt_gateway
);
1558 /* No redirected packets during ip_rt_redirect_silence;
1559 * reset the algorithm.
1561 if (time_after(jiffies
, peer
->rate_last
+ ip_rt_redirect_silence
))
1562 peer
->rate_tokens
= 0;
1564 /* Too many ignored redirects; do not send anything
1565 * set dst.rate_last to the last seen redirected packet.
1567 if (peer
->rate_tokens
>= ip_rt_redirect_number
) {
1568 peer
->rate_last
= jiffies
;
1572 /* Check for load limit; set rate_last to the latest sent
1575 if (peer
->rate_tokens
== 0 ||
1578 (ip_rt_redirect_load
<< peer
->rate_tokens
)))) {
1579 icmp_send(skb
, ICMP_REDIRECT
, ICMP_REDIR_HOST
, rt
->rt_gateway
);
1580 peer
->rate_last
= jiffies
;
1581 ++peer
->rate_tokens
;
1582 #ifdef CONFIG_IP_ROUTE_VERBOSE
1584 peer
->rate_tokens
== ip_rt_redirect_number
)
1585 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
1586 &ip_hdr(skb
)->saddr
, rt
->rt_iif
,
1587 &rt
->rt_dst
, &rt
->rt_gateway
);
1594 static int ip_error(struct sk_buff
*skb
)
1596 struct in_device
*in_dev
= __in_dev_get_rcu(skb
->dev
);
1597 struct rtable
*rt
= skb_rtable(skb
);
1598 struct inet_peer
*peer
;
1604 net
= dev_net(rt
->dst
.dev
);
1605 if (!IN_DEV_FORWARD(in_dev
)) {
1606 switch (rt
->dst
.error
) {
1608 IP_INC_STATS_BH(net
, IPSTATS_MIB_INADDRERRORS
);
1612 IP_INC_STATS_BH(net
, IPSTATS_MIB_INNOROUTES
);
1618 switch (rt
->dst
.error
) {
1623 code
= ICMP_HOST_UNREACH
;
1626 code
= ICMP_NET_UNREACH
;
1627 IP_INC_STATS_BH(net
, IPSTATS_MIB_INNOROUTES
);
1630 code
= ICMP_PKT_FILTERED
;
1634 peer
= inet_getpeer_v4(net
->ipv4
.peers
, ip_hdr(skb
)->saddr
, 1);
1639 peer
->rate_tokens
+= now
- peer
->rate_last
;
1640 if (peer
->rate_tokens
> ip_rt_error_burst
)
1641 peer
->rate_tokens
= ip_rt_error_burst
;
1642 peer
->rate_last
= now
;
1643 if (peer
->rate_tokens
>= ip_rt_error_cost
)
1644 peer
->rate_tokens
-= ip_rt_error_cost
;
1650 icmp_send(skb
, ICMP_DEST_UNREACH
, code
, 0);
1652 out
: kfree_skb(skb
);
1656 static void __ip_rt_update_pmtu(struct rtable
*rt
, struct flowi4
*fl4
, u32 mtu
)
1658 struct fib_result res
;
1660 if (mtu
< ip_rt_min_pmtu
)
1661 mtu
= ip_rt_min_pmtu
;
1663 if (fib_lookup(dev_net(rt
->dst
.dev
), fl4
, &res
) == 0) {
1664 struct fib_nh
*nh
= &FIB_RES_NH(res
);
1665 struct fib_nh_exception
*fnhe
;
1667 spin_lock_bh(&fnhe_lock
);
1668 fnhe
= find_or_create_fnhe(nh
, fl4
->daddr
);
1670 fnhe
->fnhe_pmtu
= mtu
;
1671 fnhe
->fnhe_expires
= jiffies
+ ip_rt_mtu_expires
;
1673 spin_unlock_bh(&fnhe_lock
);
1676 dst_set_expires(&rt
->dst
, ip_rt_mtu_expires
);
1679 static void ip_rt_update_pmtu(struct dst_entry
*dst
, struct sock
*sk
,
1680 struct sk_buff
*skb
, u32 mtu
)
1682 struct rtable
*rt
= (struct rtable
*) dst
;
1685 ip_rt_build_flow_key(&fl4
, sk
, skb
);
1686 __ip_rt_update_pmtu(rt
, &fl4
, mtu
);
1689 void ipv4_update_pmtu(struct sk_buff
*skb
, struct net
*net
, u32 mtu
,
1690 int oif
, u32 mark
, u8 protocol
, int flow_flags
)
1692 const struct iphdr
*iph
= (const struct iphdr
*) skb
->data
;
1696 __build_flow_key(&fl4
, NULL
, iph
, oif
,
1697 RT_TOS(iph
->tos
), protocol
, mark
, flow_flags
);
1698 rt
= __ip_route_output_key(net
, &fl4
);
1700 __ip_rt_update_pmtu(rt
, &fl4
, mtu
);
1704 EXPORT_SYMBOL_GPL(ipv4_update_pmtu
);
1706 void ipv4_sk_update_pmtu(struct sk_buff
*skb
, struct sock
*sk
, u32 mtu
)
1708 const struct iphdr
*iph
= (const struct iphdr
*) skb
->data
;
1712 __build_flow_key(&fl4
, sk
, iph
, 0, 0, 0, 0, 0);
1713 rt
= __ip_route_output_key(sock_net(sk
), &fl4
);
1715 __ip_rt_update_pmtu(rt
, &fl4
, mtu
);
1719 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu
);
1721 void ipv4_redirect(struct sk_buff
*skb
, struct net
*net
,
1722 int oif
, u32 mark
, u8 protocol
, int flow_flags
)
1724 const struct iphdr
*iph
= (const struct iphdr
*) skb
->data
;
1728 __build_flow_key(&fl4
, NULL
, iph
, oif
,
1729 RT_TOS(iph
->tos
), protocol
, mark
, flow_flags
);
1730 rt
= __ip_route_output_key(net
, &fl4
);
1732 __ip_do_redirect(rt
, skb
, &fl4
);
1736 EXPORT_SYMBOL_GPL(ipv4_redirect
);
1738 void ipv4_sk_redirect(struct sk_buff
*skb
, struct sock
*sk
)
1740 const struct iphdr
*iph
= (const struct iphdr
*) skb
->data
;
1744 __build_flow_key(&fl4
, sk
, iph
, 0, 0, 0, 0, 0);
1745 rt
= __ip_route_output_key(sock_net(sk
), &fl4
);
1747 __ip_do_redirect(rt
, skb
, &fl4
);
1751 EXPORT_SYMBOL_GPL(ipv4_sk_redirect
);
1753 static struct dst_entry
*ipv4_dst_check(struct dst_entry
*dst
, u32 cookie
)
1755 struct rtable
*rt
= (struct rtable
*) dst
;
1757 if (rt_is_expired(rt
))
1762 static void ipv4_dst_destroy(struct dst_entry
*dst
)
1764 struct rtable
*rt
= (struct rtable
*) dst
;
1767 fib_info_put(rt
->fi
);
1773 static void ipv4_link_failure(struct sk_buff
*skb
)
1777 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_HOST_UNREACH
, 0);
1779 rt
= skb_rtable(skb
);
1781 dst_set_expires(&rt
->dst
, 0);
1784 static int ip_rt_bug(struct sk_buff
*skb
)
1786 pr_debug("%s: %pI4 -> %pI4, %s\n",
1787 __func__
, &ip_hdr(skb
)->saddr
, &ip_hdr(skb
)->daddr
,
1788 skb
->dev
? skb
->dev
->name
: "?");
1795 We do not cache source address of outgoing interface,
1796 because it is used only by IP RR, TS and SRR options,
1797 so that it out of fast path.
1799 BTW remember: "addr" is allowed to be not aligned
1803 void ip_rt_get_source(u8
*addr
, struct sk_buff
*skb
, struct rtable
*rt
)
1807 if (rt_is_output_route(rt
))
1808 src
= ip_hdr(skb
)->saddr
;
1810 struct fib_result res
;
1816 memset(&fl4
, 0, sizeof(fl4
));
1817 fl4
.daddr
= iph
->daddr
;
1818 fl4
.saddr
= iph
->saddr
;
1819 fl4
.flowi4_tos
= RT_TOS(iph
->tos
);
1820 fl4
.flowi4_oif
= rt
->dst
.dev
->ifindex
;
1821 fl4
.flowi4_iif
= skb
->dev
->ifindex
;
1822 fl4
.flowi4_mark
= skb
->mark
;
1825 if (fib_lookup(dev_net(rt
->dst
.dev
), &fl4
, &res
) == 0)
1826 src
= FIB_RES_PREFSRC(dev_net(rt
->dst
.dev
), res
);
1828 src
= inet_select_addr(rt
->dst
.dev
, rt
->rt_gateway
,
1832 memcpy(addr
, &src
, 4);
1835 #ifdef CONFIG_IP_ROUTE_CLASSID
1836 static void set_class_tag(struct rtable
*rt
, u32 tag
)
1838 if (!(rt
->dst
.tclassid
& 0xFFFF))
1839 rt
->dst
.tclassid
|= tag
& 0xFFFF;
1840 if (!(rt
->dst
.tclassid
& 0xFFFF0000))
1841 rt
->dst
.tclassid
|= tag
& 0xFFFF0000;
1845 static unsigned int ipv4_default_advmss(const struct dst_entry
*dst
)
1847 unsigned int advmss
= dst_metric_raw(dst
, RTAX_ADVMSS
);
1850 advmss
= max_t(unsigned int, dst
->dev
->mtu
- 40,
1852 if (advmss
> 65535 - 40)
1853 advmss
= 65535 - 40;
1858 static unsigned int ipv4_mtu(const struct dst_entry
*dst
)
1860 const struct rtable
*rt
= (const struct rtable
*) dst
;
1861 unsigned int mtu
= rt
->rt_pmtu
;
1863 if (mtu
&& time_after_eq(jiffies
, rt
->dst
.expires
))
1867 mtu
= dst_metric_raw(dst
, RTAX_MTU
);
1869 if (mtu
&& rt_is_output_route(rt
))
1872 mtu
= dst
->dev
->mtu
;
1874 if (unlikely(dst_metric_locked(dst
, RTAX_MTU
))) {
1876 if (rt
->rt_gateway
!= rt
->rt_dst
&& mtu
> 576)
1880 if (mtu
> IP_MAX_MTU
)
1886 static void rt_init_metrics(struct rtable
*rt
, const struct flowi4
*fl4
,
1887 struct fib_info
*fi
)
1889 if (fi
->fib_metrics
!= (u32
*) dst_default_metrics
) {
1891 atomic_inc(&fi
->fib_clntref
);
1893 dst_init_metrics(&rt
->dst
, fi
->fib_metrics
, true);
1896 static void rt_bind_exception(struct rtable
*rt
, struct fib_nh
*nh
, __be32 daddr
)
1898 struct fnhe_hash_bucket
*hash
= nh
->nh_exceptions
;
1899 struct fib_nh_exception
*fnhe
;
1902 hval
= fnhe_hashfun(daddr
);
1904 for (fnhe
= rcu_dereference(hash
[hval
].chain
); fnhe
;
1905 fnhe
= rcu_dereference(fnhe
->fnhe_next
)) {
1906 if (fnhe
->fnhe_daddr
== daddr
) {
1907 if (fnhe
->fnhe_pmtu
) {
1908 unsigned long expires
= fnhe
->fnhe_expires
;
1909 unsigned long diff
= jiffies
- expires
;
1911 if (time_before(jiffies
, expires
)) {
1912 rt
->rt_pmtu
= fnhe
->fnhe_pmtu
;
1913 dst_set_expires(&rt
->dst
, diff
);
1917 rt
->rt_gateway
= fnhe
->fnhe_gw
;
1918 fnhe
->fnhe_stamp
= jiffies
;
1924 static void rt_set_nexthop(struct rtable
*rt
, const struct flowi4
*fl4
,
1925 const struct fib_result
*res
,
1926 struct fib_info
*fi
, u16 type
, u32 itag
)
1929 struct fib_nh
*nh
= &FIB_RES_NH(*res
);
1931 if (nh
->nh_gw
&& nh
->nh_scope
== RT_SCOPE_LINK
)
1932 rt
->rt_gateway
= nh
->nh_gw
;
1933 if (unlikely(nh
->nh_exceptions
))
1934 rt_bind_exception(rt
, nh
, fl4
->daddr
);
1935 rt_init_metrics(rt
, fl4
, fi
);
1936 #ifdef CONFIG_IP_ROUTE_CLASSID
1937 rt
->dst
.tclassid
= FIB_RES_NH(*res
).nh_tclassid
;
1941 #ifdef CONFIG_IP_ROUTE_CLASSID
1942 #ifdef CONFIG_IP_MULTIPLE_TABLES
1943 set_class_tag(rt
, res
->tclassid
);
1945 set_class_tag(rt
, itag
);
1949 static struct rtable
*rt_dst_alloc(struct net_device
*dev
,
1950 bool nopolicy
, bool noxfrm
)
1952 return dst_alloc(&ipv4_dst_ops
, dev
, 1, -1,
1954 (nopolicy
? DST_NOPOLICY
: 0) |
1955 (noxfrm
? DST_NOXFRM
: 0));
1958 /* called in rcu_read_lock() section */
1959 static int ip_route_input_mc(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
1960 u8 tos
, struct net_device
*dev
, int our
)
1964 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
1968 /* Primary sanity checks. */
1973 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
) ||
1974 skb
->protocol
!= htons(ETH_P_IP
))
1977 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev
)))
1978 if (ipv4_is_loopback(saddr
))
1981 if (ipv4_is_zeronet(saddr
)) {
1982 if (!ipv4_is_local_multicast(daddr
))
1985 err
= fib_validate_source(skb
, saddr
, 0, tos
, 0, dev
,
1990 rth
= rt_dst_alloc(dev_net(dev
)->loopback_dev
,
1991 IN_DEV_CONF_GET(in_dev
, NOPOLICY
), false);
1995 #ifdef CONFIG_IP_ROUTE_CLASSID
1996 rth
->dst
.tclassid
= itag
;
1998 rth
->dst
.output
= ip_rt_bug
;
2000 rth
->rt_key_dst
= daddr
;
2001 rth
->rt_key_src
= saddr
;
2002 rth
->rt_genid
= rt_genid(dev_net(dev
));
2003 rth
->rt_flags
= RTCF_MULTICAST
;
2004 rth
->rt_type
= RTN_MULTICAST
;
2005 rth
->rt_key_tos
= tos
;
2006 rth
->rt_dst
= daddr
;
2007 rth
->rt_src
= saddr
;
2008 rth
->rt_route_iif
= dev
->ifindex
;
2009 rth
->rt_iif
= dev
->ifindex
;
2011 rth
->rt_mark
= skb
->mark
;
2013 rth
->rt_gateway
= daddr
;
2016 rth
->dst
.input
= ip_local_deliver
;
2017 rth
->rt_flags
|= RTCF_LOCAL
;
2020 #ifdef CONFIG_IP_MROUTE
2021 if (!ipv4_is_local_multicast(daddr
) && IN_DEV_MFORWARD(in_dev
))
2022 rth
->dst
.input
= ip_mr_input
;
2024 RT_CACHE_STAT_INC(in_slow_mc
);
2026 hash
= rt_hash(daddr
, saddr
, dev
->ifindex
, rt_genid(dev_net(dev
)));
2027 rth
= rt_intern_hash(hash
, rth
, skb
, dev
->ifindex
);
2028 return IS_ERR(rth
) ? PTR_ERR(rth
) : 0;
2039 static void ip_handle_martian_source(struct net_device
*dev
,
2040 struct in_device
*in_dev
,
2041 struct sk_buff
*skb
,
2045 RT_CACHE_STAT_INC(in_martian_src
);
2046 #ifdef CONFIG_IP_ROUTE_VERBOSE
2047 if (IN_DEV_LOG_MARTIANS(in_dev
) && net_ratelimit()) {
2049 * RFC1812 recommendation, if source is martian,
2050 * the only hint is MAC header.
2052 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
2053 &daddr
, &saddr
, dev
->name
);
2054 if (dev
->hard_header_len
&& skb_mac_header_was_set(skb
)) {
2055 print_hex_dump(KERN_WARNING
, "ll header: ",
2056 DUMP_PREFIX_OFFSET
, 16, 1,
2057 skb_mac_header(skb
),
2058 dev
->hard_header_len
, true);
2064 /* called in rcu_read_lock() section */
2065 static int __mkroute_input(struct sk_buff
*skb
,
2066 const struct fib_result
*res
,
2067 struct in_device
*in_dev
,
2068 __be32 daddr
, __be32 saddr
, u32 tos
,
2069 struct rtable
**result
)
2073 struct in_device
*out_dev
;
2074 unsigned int flags
= 0;
2077 /* get a working reference to the output device */
2078 out_dev
= __in_dev_get_rcu(FIB_RES_DEV(*res
));
2079 if (out_dev
== NULL
) {
2080 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
2085 err
= fib_validate_source(skb
, saddr
, daddr
, tos
, FIB_RES_OIF(*res
),
2086 in_dev
->dev
, in_dev
, &itag
);
2088 ip_handle_martian_source(in_dev
->dev
, in_dev
, skb
, daddr
,
2095 flags
|= RTCF_DIRECTSRC
;
2097 if (out_dev
== in_dev
&& err
&&
2098 (IN_DEV_SHARED_MEDIA(out_dev
) ||
2099 inet_addr_onlink(out_dev
, saddr
, FIB_RES_GW(*res
))))
2100 flags
|= RTCF_DOREDIRECT
;
2102 if (skb
->protocol
!= htons(ETH_P_IP
)) {
2103 /* Not IP (i.e. ARP). Do not create route, if it is
2104 * invalid for proxy arp. DNAT routes are always valid.
2106 * Proxy arp feature have been extended to allow, ARP
2107 * replies back to the same interface, to support
2108 * Private VLAN switch technologies. See arp.c.
2110 if (out_dev
== in_dev
&&
2111 IN_DEV_PROXY_ARP_PVLAN(in_dev
) == 0) {
2117 rth
= rt_dst_alloc(out_dev
->dev
,
2118 IN_DEV_CONF_GET(in_dev
, NOPOLICY
),
2119 IN_DEV_CONF_GET(out_dev
, NOXFRM
));
2125 rth
->rt_key_dst
= daddr
;
2126 rth
->rt_key_src
= saddr
;
2127 rth
->rt_genid
= rt_genid(dev_net(rth
->dst
.dev
));
2128 rth
->rt_flags
= flags
;
2129 rth
->rt_type
= res
->type
;
2130 rth
->rt_key_tos
= tos
;
2131 rth
->rt_dst
= daddr
;
2132 rth
->rt_src
= saddr
;
2133 rth
->rt_route_iif
= in_dev
->dev
->ifindex
;
2134 rth
->rt_iif
= in_dev
->dev
->ifindex
;
2136 rth
->rt_mark
= skb
->mark
;
2138 rth
->rt_gateway
= daddr
;
2141 rth
->dst
.input
= ip_forward
;
2142 rth
->dst
.output
= ip_output
;
2144 rt_set_nexthop(rth
, NULL
, res
, res
->fi
, res
->type
, itag
);
2152 static int ip_mkroute_input(struct sk_buff
*skb
,
2153 struct fib_result
*res
,
2154 const struct flowi4
*fl4
,
2155 struct in_device
*in_dev
,
2156 __be32 daddr
, __be32 saddr
, u32 tos
)
2158 struct rtable
*rth
= NULL
;
2162 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2163 if (res
->fi
&& res
->fi
->fib_nhs
> 1)
2164 fib_select_multipath(res
);
2167 /* create a routing cache entry */
2168 err
= __mkroute_input(skb
, res
, in_dev
, daddr
, saddr
, tos
, &rth
);
2172 /* put it into the cache */
2173 hash
= rt_hash(daddr
, saddr
, fl4
->flowi4_iif
,
2174 rt_genid(dev_net(rth
->dst
.dev
)));
2175 rth
= rt_intern_hash(hash
, rth
, skb
, fl4
->flowi4_iif
);
2177 return PTR_ERR(rth
);
2182 * NOTE. We drop all the packets that has local source
2183 * addresses, because every properly looped back packet
2184 * must have correct destination already attached by output routine.
2186 * Such approach solves two big problems:
2187 * 1. Not simplex devices are handled properly.
2188 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2189 * called with rcu_read_lock()
2192 static int ip_route_input_slow(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2193 u8 tos
, struct net_device
*dev
)
2195 struct fib_result res
;
2196 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
2198 unsigned int flags
= 0;
2203 struct net
*net
= dev_net(dev
);
2205 /* IP on this device is disabled. */
2210 /* Check for the most weird martians, which can be not detected
2214 if (ipv4_is_multicast(saddr
) || ipv4_is_lbcast(saddr
))
2215 goto martian_source
;
2217 if (ipv4_is_lbcast(daddr
) || (saddr
== 0 && daddr
== 0))
2220 /* Accept zero addresses only to limited broadcast;
2221 * I even do not know to fix it or not. Waiting for complains :-)
2223 if (ipv4_is_zeronet(saddr
))
2224 goto martian_source
;
2226 if (ipv4_is_zeronet(daddr
))
2227 goto martian_destination
;
2229 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev
))) {
2230 if (ipv4_is_loopback(daddr
))
2231 goto martian_destination
;
2233 if (ipv4_is_loopback(saddr
))
2234 goto martian_source
;
2238 * Now we are ready to route packet.
2241 fl4
.flowi4_iif
= dev
->ifindex
;
2242 fl4
.flowi4_mark
= skb
->mark
;
2243 fl4
.flowi4_tos
= tos
;
2244 fl4
.flowi4_scope
= RT_SCOPE_UNIVERSE
;
2247 err
= fib_lookup(net
, &fl4
, &res
);
2251 RT_CACHE_STAT_INC(in_slow_tot
);
2253 if (res
.type
== RTN_BROADCAST
)
2256 if (res
.type
== RTN_LOCAL
) {
2257 err
= fib_validate_source(skb
, saddr
, daddr
, tos
,
2258 net
->loopback_dev
->ifindex
,
2259 dev
, in_dev
, &itag
);
2261 goto martian_source_keep_err
;
2263 flags
|= RTCF_DIRECTSRC
;
2267 if (!IN_DEV_FORWARD(in_dev
))
2269 if (res
.type
!= RTN_UNICAST
)
2270 goto martian_destination
;
2272 err
= ip_mkroute_input(skb
, &res
, &fl4
, in_dev
, daddr
, saddr
, tos
);
2276 if (skb
->protocol
!= htons(ETH_P_IP
))
2279 if (!ipv4_is_zeronet(saddr
)) {
2280 err
= fib_validate_source(skb
, saddr
, 0, tos
, 0, dev
,
2283 goto martian_source_keep_err
;
2285 flags
|= RTCF_DIRECTSRC
;
2287 flags
|= RTCF_BROADCAST
;
2288 res
.type
= RTN_BROADCAST
;
2289 RT_CACHE_STAT_INC(in_brd
);
2292 rth
= rt_dst_alloc(net
->loopback_dev
,
2293 IN_DEV_CONF_GET(in_dev
, NOPOLICY
), false);
2297 rth
->dst
.input
= ip_local_deliver
;
2298 rth
->dst
.output
= ip_rt_bug
;
2299 #ifdef CONFIG_IP_ROUTE_CLASSID
2300 rth
->dst
.tclassid
= itag
;
2303 rth
->rt_key_dst
= daddr
;
2304 rth
->rt_key_src
= saddr
;
2305 rth
->rt_genid
= rt_genid(net
);
2306 rth
->rt_flags
= flags
|RTCF_LOCAL
;
2307 rth
->rt_type
= res
.type
;
2308 rth
->rt_key_tos
= tos
;
2309 rth
->rt_dst
= daddr
;
2310 rth
->rt_src
= saddr
;
2311 rth
->rt_route_iif
= dev
->ifindex
;
2312 rth
->rt_iif
= dev
->ifindex
;
2314 rth
->rt_mark
= skb
->mark
;
2316 rth
->rt_gateway
= daddr
;
2318 if (res
.type
== RTN_UNREACHABLE
) {
2319 rth
->dst
.input
= ip_error
;
2320 rth
->dst
.error
= -err
;
2321 rth
->rt_flags
&= ~RTCF_LOCAL
;
2323 hash
= rt_hash(daddr
, saddr
, fl4
.flowi4_iif
, rt_genid(net
));
2324 rth
= rt_intern_hash(hash
, rth
, skb
, fl4
.flowi4_iif
);
2331 RT_CACHE_STAT_INC(in_no_route
);
2332 res
.type
= RTN_UNREACHABLE
;
2338 * Do not cache martian addresses: they should be logged (RFC1812)
2340 martian_destination
:
2341 RT_CACHE_STAT_INC(in_martian_dst
);
2342 #ifdef CONFIG_IP_ROUTE_VERBOSE
2343 if (IN_DEV_LOG_MARTIANS(in_dev
))
2344 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2345 &daddr
, &saddr
, dev
->name
);
2358 martian_source_keep_err
:
2359 ip_handle_martian_source(dev
, in_dev
, skb
, daddr
, saddr
);
2363 int ip_route_input_common(struct sk_buff
*skb
, __be32 daddr
, __be32 saddr
,
2364 u8 tos
, struct net_device
*dev
, bool noref
)
2368 int iif
= dev
->ifindex
;
2376 if (!rt_caching(net
))
2379 tos
&= IPTOS_RT_MASK
;
2380 hash
= rt_hash(daddr
, saddr
, iif
, rt_genid(net
));
2382 for (rth
= rcu_dereference(rt_hash_table
[hash
].chain
); rth
;
2383 rth
= rcu_dereference(rth
->dst
.rt_next
)) {
2384 if ((((__force u32
)rth
->rt_key_dst
^ (__force u32
)daddr
) |
2385 ((__force u32
)rth
->rt_key_src
^ (__force u32
)saddr
) |
2386 (rth
->rt_route_iif
^ iif
) |
2387 (rth
->rt_key_tos
^ tos
)) == 0 &&
2388 rth
->rt_mark
== skb
->mark
&&
2389 net_eq(dev_net(rth
->dst
.dev
), net
) &&
2390 !rt_is_expired(rth
)) {
2392 dst_use_noref(&rth
->dst
, jiffies
);
2393 skb_dst_set_noref(skb
, &rth
->dst
);
2395 dst_use(&rth
->dst
, jiffies
);
2396 skb_dst_set(skb
, &rth
->dst
);
2398 RT_CACHE_STAT_INC(in_hit
);
2402 RT_CACHE_STAT_INC(in_hlist_search
);
2406 /* Multicast recognition logic is moved from route cache to here.
2407 The problem was that too many Ethernet cards have broken/missing
2408 hardware multicast filters :-( As result the host on multicasting
2409 network acquires a lot of useless route cache entries, sort of
2410 SDR messages from all the world. Now we try to get rid of them.
2411 Really, provided software IP multicast filter is organized
2412 reasonably (at least, hashed), it does not result in a slowdown
2413 comparing with route cache reject entries.
2414 Note, that multicast routers are not affected, because
2415 route cache entry is created eventually.
2417 if (ipv4_is_multicast(daddr
)) {
2418 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
2421 int our
= ip_check_mc_rcu(in_dev
, daddr
, saddr
,
2422 ip_hdr(skb
)->protocol
);
2424 #ifdef CONFIG_IP_MROUTE
2426 (!ipv4_is_local_multicast(daddr
) &&
2427 IN_DEV_MFORWARD(in_dev
))
2430 int res
= ip_route_input_mc(skb
, daddr
, saddr
,
2439 res
= ip_route_input_slow(skb
, daddr
, saddr
, tos
, dev
);
2443 EXPORT_SYMBOL(ip_route_input_common
);
2445 /* called with rcu_read_lock() */
2446 static struct rtable
*__mkroute_output(const struct fib_result
*res
,
2447 const struct flowi4
*fl4
,
2448 __be32 orig_daddr
, __be32 orig_saddr
,
2449 int orig_oif
, __u8 orig_rtos
,
2450 struct net_device
*dev_out
,
2453 struct fib_info
*fi
= res
->fi
;
2454 struct in_device
*in_dev
;
2455 u16 type
= res
->type
;
2458 in_dev
= __in_dev_get_rcu(dev_out
);
2460 return ERR_PTR(-EINVAL
);
2462 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev
)))
2463 if (ipv4_is_loopback(fl4
->saddr
) && !(dev_out
->flags
& IFF_LOOPBACK
))
2464 return ERR_PTR(-EINVAL
);
2466 if (ipv4_is_lbcast(fl4
->daddr
))
2467 type
= RTN_BROADCAST
;
2468 else if (ipv4_is_multicast(fl4
->daddr
))
2469 type
= RTN_MULTICAST
;
2470 else if (ipv4_is_zeronet(fl4
->daddr
))
2471 return ERR_PTR(-EINVAL
);
2473 if (dev_out
->flags
& IFF_LOOPBACK
)
2474 flags
|= RTCF_LOCAL
;
2476 if (type
== RTN_BROADCAST
) {
2477 flags
|= RTCF_BROADCAST
| RTCF_LOCAL
;
2479 } else if (type
== RTN_MULTICAST
) {
2480 flags
|= RTCF_MULTICAST
| RTCF_LOCAL
;
2481 if (!ip_check_mc_rcu(in_dev
, fl4
->daddr
, fl4
->saddr
,
2483 flags
&= ~RTCF_LOCAL
;
2484 /* If multicast route do not exist use
2485 * default one, but do not gateway in this case.
2488 if (fi
&& res
->prefixlen
< 4)
2492 rth
= rt_dst_alloc(dev_out
,
2493 IN_DEV_CONF_GET(in_dev
, NOPOLICY
),
2494 IN_DEV_CONF_GET(in_dev
, NOXFRM
));
2496 return ERR_PTR(-ENOBUFS
);
2498 rth
->dst
.output
= ip_output
;
2500 rth
->rt_key_dst
= orig_daddr
;
2501 rth
->rt_key_src
= orig_saddr
;
2502 rth
->rt_genid
= rt_genid(dev_net(dev_out
));
2503 rth
->rt_flags
= flags
;
2504 rth
->rt_type
= type
;
2505 rth
->rt_key_tos
= orig_rtos
;
2506 rth
->rt_dst
= fl4
->daddr
;
2507 rth
->rt_src
= fl4
->saddr
;
2508 rth
->rt_route_iif
= 0;
2509 rth
->rt_iif
= orig_oif
? : dev_out
->ifindex
;
2510 rth
->rt_oif
= orig_oif
;
2511 rth
->rt_mark
= fl4
->flowi4_mark
;
2513 rth
->rt_gateway
= fl4
->daddr
;
2516 RT_CACHE_STAT_INC(out_slow_tot
);
2518 if (flags
& RTCF_LOCAL
)
2519 rth
->dst
.input
= ip_local_deliver
;
2520 if (flags
& (RTCF_BROADCAST
| RTCF_MULTICAST
)) {
2521 if (flags
& RTCF_LOCAL
&&
2522 !(dev_out
->flags
& IFF_LOOPBACK
)) {
2523 rth
->dst
.output
= ip_mc_output
;
2524 RT_CACHE_STAT_INC(out_slow_mc
);
2526 #ifdef CONFIG_IP_MROUTE
2527 if (type
== RTN_MULTICAST
) {
2528 if (IN_DEV_MFORWARD(in_dev
) &&
2529 !ipv4_is_local_multicast(fl4
->daddr
)) {
2530 rth
->dst
.input
= ip_mr_input
;
2531 rth
->dst
.output
= ip_mc_output
;
2537 rt_set_nexthop(rth
, fl4
, res
, fi
, type
, 0);
2539 if (fl4
->flowi4_flags
& FLOWI_FLAG_RT_NOCACHE
)
2540 rth
->dst
.flags
|= DST_NOCACHE
;
2546 * Major route resolver routine.
2547 * called with rcu_read_lock();
2550 static struct rtable
*ip_route_output_slow(struct net
*net
, struct flowi4
*fl4
)
2552 struct net_device
*dev_out
= NULL
;
2553 __u8 tos
= RT_FL_TOS(fl4
);
2554 unsigned int flags
= 0;
2555 struct fib_result res
;
2565 orig_daddr
= fl4
->daddr
;
2566 orig_saddr
= fl4
->saddr
;
2567 orig_oif
= fl4
->flowi4_oif
;
2569 fl4
->flowi4_iif
= net
->loopback_dev
->ifindex
;
2570 fl4
->flowi4_tos
= tos
& IPTOS_RT_MASK
;
2571 fl4
->flowi4_scope
= ((tos
& RTO_ONLINK
) ?
2572 RT_SCOPE_LINK
: RT_SCOPE_UNIVERSE
);
2576 rth
= ERR_PTR(-EINVAL
);
2577 if (ipv4_is_multicast(fl4
->saddr
) ||
2578 ipv4_is_lbcast(fl4
->saddr
) ||
2579 ipv4_is_zeronet(fl4
->saddr
))
2582 /* I removed check for oif == dev_out->oif here.
2583 It was wrong for two reasons:
2584 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2585 is assigned to multiple interfaces.
2586 2. Moreover, we are allowed to send packets with saddr
2587 of another iface. --ANK
2590 if (fl4
->flowi4_oif
== 0 &&
2591 (ipv4_is_multicast(fl4
->daddr
) ||
2592 ipv4_is_lbcast(fl4
->daddr
))) {
2593 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2594 dev_out
= __ip_dev_find(net
, fl4
->saddr
, false);
2595 if (dev_out
== NULL
)
2598 /* Special hack: user can direct multicasts
2599 and limited broadcast via necessary interface
2600 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2601 This hack is not just for fun, it allows
2602 vic,vat and friends to work.
2603 They bind socket to loopback, set ttl to zero
2604 and expect that it will work.
2605 From the viewpoint of routing cache they are broken,
2606 because we are not allowed to build multicast path
2607 with loopback source addr (look, routing cache
2608 cannot know, that ttl is zero, so that packet
2609 will not leave this host and route is valid).
2610 Luckily, this hack is good workaround.
2613 fl4
->flowi4_oif
= dev_out
->ifindex
;
2617 if (!(fl4
->flowi4_flags
& FLOWI_FLAG_ANYSRC
)) {
2618 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2619 if (!__ip_dev_find(net
, fl4
->saddr
, false))
2625 if (fl4
->flowi4_oif
) {
2626 dev_out
= dev_get_by_index_rcu(net
, fl4
->flowi4_oif
);
2627 rth
= ERR_PTR(-ENODEV
);
2628 if (dev_out
== NULL
)
2631 /* RACE: Check return value of inet_select_addr instead. */
2632 if (!(dev_out
->flags
& IFF_UP
) || !__in_dev_get_rcu(dev_out
)) {
2633 rth
= ERR_PTR(-ENETUNREACH
);
2636 if (ipv4_is_local_multicast(fl4
->daddr
) ||
2637 ipv4_is_lbcast(fl4
->daddr
)) {
2639 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2644 if (ipv4_is_multicast(fl4
->daddr
))
2645 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2647 else if (!fl4
->daddr
)
2648 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2654 fl4
->daddr
= fl4
->saddr
;
2656 fl4
->daddr
= fl4
->saddr
= htonl(INADDR_LOOPBACK
);
2657 dev_out
= net
->loopback_dev
;
2658 fl4
->flowi4_oif
= net
->loopback_dev
->ifindex
;
2659 res
.type
= RTN_LOCAL
;
2660 flags
|= RTCF_LOCAL
;
2664 if (fib_lookup(net
, fl4
, &res
)) {
2667 if (fl4
->flowi4_oif
) {
2668 /* Apparently, routing tables are wrong. Assume,
2669 that the destination is on link.
2672 Because we are allowed to send to iface
2673 even if it has NO routes and NO assigned
2674 addresses. When oif is specified, routing
2675 tables are looked up with only one purpose:
2676 to catch if destination is gatewayed, rather than
2677 direct. Moreover, if MSG_DONTROUTE is set,
2678 we send packet, ignoring both routing tables
2679 and ifaddr state. --ANK
2682 We could make it even if oif is unknown,
2683 likely IPv6, but we do not.
2686 if (fl4
->saddr
== 0)
2687 fl4
->saddr
= inet_select_addr(dev_out
, 0,
2689 res
.type
= RTN_UNICAST
;
2692 rth
= ERR_PTR(-ENETUNREACH
);
2696 if (res
.type
== RTN_LOCAL
) {
2698 if (res
.fi
->fib_prefsrc
)
2699 fl4
->saddr
= res
.fi
->fib_prefsrc
;
2701 fl4
->saddr
= fl4
->daddr
;
2703 dev_out
= net
->loopback_dev
;
2704 fl4
->flowi4_oif
= dev_out
->ifindex
;
2706 flags
|= RTCF_LOCAL
;
2710 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2711 if (res
.fi
->fib_nhs
> 1 && fl4
->flowi4_oif
== 0)
2712 fib_select_multipath(&res
);
2715 if (!res
.prefixlen
&&
2716 res
.table
->tb_num_default
> 1 &&
2717 res
.type
== RTN_UNICAST
&& !fl4
->flowi4_oif
)
2718 fib_select_default(&res
);
2721 fl4
->saddr
= FIB_RES_PREFSRC(net
, res
);
2723 dev_out
= FIB_RES_DEV(res
);
2724 fl4
->flowi4_oif
= dev_out
->ifindex
;
2728 rth
= __mkroute_output(&res
, fl4
, orig_daddr
, orig_saddr
, orig_oif
,
2729 tos
, dev_out
, flags
);
2733 hash
= rt_hash(orig_daddr
, orig_saddr
, orig_oif
,
2734 rt_genid(dev_net(dev_out
)));
2735 rth
= rt_intern_hash(hash
, rth
, NULL
, orig_oif
);
2743 struct rtable
*__ip_route_output_key(struct net
*net
, struct flowi4
*flp4
)
2748 if (!rt_caching(net
))
2751 hash
= rt_hash(flp4
->daddr
, flp4
->saddr
, flp4
->flowi4_oif
, rt_genid(net
));
2754 for (rth
= rcu_dereference_bh(rt_hash_table
[hash
].chain
); rth
;
2755 rth
= rcu_dereference_bh(rth
->dst
.rt_next
)) {
2756 if (rth
->rt_key_dst
== flp4
->daddr
&&
2757 rth
->rt_key_src
== flp4
->saddr
&&
2758 rt_is_output_route(rth
) &&
2759 rth
->rt_oif
== flp4
->flowi4_oif
&&
2760 rth
->rt_mark
== flp4
->flowi4_mark
&&
2761 !((rth
->rt_key_tos
^ flp4
->flowi4_tos
) &
2762 (IPTOS_RT_MASK
| RTO_ONLINK
)) &&
2763 net_eq(dev_net(rth
->dst
.dev
), net
) &&
2764 !rt_is_expired(rth
)) {
2765 dst_use(&rth
->dst
, jiffies
);
2766 RT_CACHE_STAT_INC(out_hit
);
2767 rcu_read_unlock_bh();
2769 flp4
->saddr
= rth
->rt_src
;
2771 flp4
->daddr
= rth
->rt_dst
;
2774 RT_CACHE_STAT_INC(out_hlist_search
);
2776 rcu_read_unlock_bh();
2779 return ip_route_output_slow(net
, flp4
);
2781 EXPORT_SYMBOL_GPL(__ip_route_output_key
);
2783 static struct dst_entry
*ipv4_blackhole_dst_check(struct dst_entry
*dst
, u32 cookie
)
2788 static unsigned int ipv4_blackhole_mtu(const struct dst_entry
*dst
)
2790 unsigned int mtu
= dst_metric_raw(dst
, RTAX_MTU
);
2792 return mtu
? : dst
->dev
->mtu
;
2795 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry
*dst
, struct sock
*sk
,
2796 struct sk_buff
*skb
, u32 mtu
)
2800 static void ipv4_rt_blackhole_redirect(struct dst_entry
*dst
, struct sock
*sk
,
2801 struct sk_buff
*skb
)
2805 static u32
*ipv4_rt_blackhole_cow_metrics(struct dst_entry
*dst
,
2811 static struct dst_ops ipv4_dst_blackhole_ops
= {
2813 .protocol
= cpu_to_be16(ETH_P_IP
),
2814 .destroy
= ipv4_dst_destroy
,
2815 .check
= ipv4_blackhole_dst_check
,
2816 .mtu
= ipv4_blackhole_mtu
,
2817 .default_advmss
= ipv4_default_advmss
,
2818 .update_pmtu
= ipv4_rt_blackhole_update_pmtu
,
2819 .redirect
= ipv4_rt_blackhole_redirect
,
2820 .cow_metrics
= ipv4_rt_blackhole_cow_metrics
,
2821 .neigh_lookup
= ipv4_neigh_lookup
,
2824 struct dst_entry
*ipv4_blackhole_route(struct net
*net
, struct dst_entry
*dst_orig
)
2826 struct rtable
*rt
= dst_alloc(&ipv4_dst_blackhole_ops
, NULL
, 1, 0, 0);
2827 struct rtable
*ort
= (struct rtable
*) dst_orig
;
2830 struct dst_entry
*new = &rt
->dst
;
2833 new->input
= dst_discard
;
2834 new->output
= dst_discard
;
2836 new->dev
= ort
->dst
.dev
;
2840 rt
->rt_key_dst
= ort
->rt_key_dst
;
2841 rt
->rt_key_src
= ort
->rt_key_src
;
2842 rt
->rt_key_tos
= ort
->rt_key_tos
;
2843 rt
->rt_route_iif
= ort
->rt_route_iif
;
2844 rt
->rt_iif
= ort
->rt_iif
;
2845 rt
->rt_oif
= ort
->rt_oif
;
2846 rt
->rt_mark
= ort
->rt_mark
;
2847 rt
->rt_pmtu
= ort
->rt_pmtu
;
2849 rt
->rt_genid
= rt_genid(net
);
2850 rt
->rt_flags
= ort
->rt_flags
;
2851 rt
->rt_type
= ort
->rt_type
;
2852 rt
->rt_dst
= ort
->rt_dst
;
2853 rt
->rt_src
= ort
->rt_src
;
2854 rt
->rt_gateway
= ort
->rt_gateway
;
2857 atomic_inc(&rt
->fi
->fib_clntref
);
2862 dst_release(dst_orig
);
2864 return rt
? &rt
->dst
: ERR_PTR(-ENOMEM
);
2867 struct rtable
*ip_route_output_flow(struct net
*net
, struct flowi4
*flp4
,
2870 struct rtable
*rt
= __ip_route_output_key(net
, flp4
);
2875 if (flp4
->flowi4_proto
)
2876 rt
= (struct rtable
*) xfrm_lookup(net
, &rt
->dst
,
2877 flowi4_to_flowi(flp4
),
2882 EXPORT_SYMBOL_GPL(ip_route_output_flow
);
2884 static int rt_fill_info(struct net
*net
,
2885 struct sk_buff
*skb
, u32 pid
, u32 seq
, int event
,
2886 int nowait
, unsigned int flags
)
2888 struct rtable
*rt
= skb_rtable(skb
);
2890 struct nlmsghdr
*nlh
;
2891 unsigned long expires
= 0;
2894 nlh
= nlmsg_put(skb
, pid
, seq
, event
, sizeof(*r
), flags
);
2898 r
= nlmsg_data(nlh
);
2899 r
->rtm_family
= AF_INET
;
2900 r
->rtm_dst_len
= 32;
2902 r
->rtm_tos
= rt
->rt_key_tos
;
2903 r
->rtm_table
= RT_TABLE_MAIN
;
2904 if (nla_put_u32(skb
, RTA_TABLE
, RT_TABLE_MAIN
))
2905 goto nla_put_failure
;
2906 r
->rtm_type
= rt
->rt_type
;
2907 r
->rtm_scope
= RT_SCOPE_UNIVERSE
;
2908 r
->rtm_protocol
= RTPROT_UNSPEC
;
2909 r
->rtm_flags
= (rt
->rt_flags
& ~0xFFFF) | RTM_F_CLONED
;
2910 if (rt
->rt_flags
& RTCF_NOTIFY
)
2911 r
->rtm_flags
|= RTM_F_NOTIFY
;
2913 if (nla_put_be32(skb
, RTA_DST
, rt
->rt_dst
))
2914 goto nla_put_failure
;
2915 if (rt
->rt_key_src
) {
2916 r
->rtm_src_len
= 32;
2917 if (nla_put_be32(skb
, RTA_SRC
, rt
->rt_key_src
))
2918 goto nla_put_failure
;
2921 nla_put_u32(skb
, RTA_OIF
, rt
->dst
.dev
->ifindex
))
2922 goto nla_put_failure
;
2923 #ifdef CONFIG_IP_ROUTE_CLASSID
2924 if (rt
->dst
.tclassid
&&
2925 nla_put_u32(skb
, RTA_FLOW
, rt
->dst
.tclassid
))
2926 goto nla_put_failure
;
2928 if (!rt_is_input_route(rt
) &&
2929 rt
->rt_src
!= rt
->rt_key_src
) {
2930 if (nla_put_be32(skb
, RTA_PREFSRC
, rt
->rt_src
))
2931 goto nla_put_failure
;
2933 if (rt
->rt_dst
!= rt
->rt_gateway
&&
2934 nla_put_be32(skb
, RTA_GATEWAY
, rt
->rt_gateway
))
2935 goto nla_put_failure
;
2937 if (rtnetlink_put_metrics(skb
, dst_metrics_ptr(&rt
->dst
)) < 0)
2938 goto nla_put_failure
;
2941 nla_put_be32(skb
, RTA_MARK
, rt
->rt_mark
))
2942 goto nla_put_failure
;
2944 error
= rt
->dst
.error
;
2945 expires
= rt
->dst
.expires
;
2947 if (time_before(jiffies
, expires
))
2953 if (rt_is_input_route(rt
)) {
2954 #ifdef CONFIG_IP_MROUTE
2955 __be32 dst
= rt
->rt_dst
;
2957 if (ipv4_is_multicast(dst
) && !ipv4_is_local_multicast(dst
) &&
2958 IPV4_DEVCONF_ALL(net
, MC_FORWARDING
)) {
2959 int err
= ipmr_get_route(net
, skb
,
2960 rt
->rt_src
, rt
->rt_dst
,
2966 goto nla_put_failure
;
2968 if (err
== -EMSGSIZE
)
2969 goto nla_put_failure
;
2975 if (nla_put_u32(skb
, RTA_IIF
, rt
->rt_iif
))
2976 goto nla_put_failure
;
2979 if (rtnl_put_cacheinfo(skb
, &rt
->dst
, 0, expires
, error
) < 0)
2980 goto nla_put_failure
;
2982 return nlmsg_end(skb
, nlh
);
2985 nlmsg_cancel(skb
, nlh
);
2989 static int inet_rtm_getroute(struct sk_buff
*in_skb
, struct nlmsghdr
*nlh
, void *arg
)
2991 struct net
*net
= sock_net(in_skb
->sk
);
2993 struct nlattr
*tb
[RTA_MAX
+1];
2994 struct rtable
*rt
= NULL
;
3000 struct sk_buff
*skb
;
3002 err
= nlmsg_parse(nlh
, sizeof(*rtm
), tb
, RTA_MAX
, rtm_ipv4_policy
);
3006 rtm
= nlmsg_data(nlh
);
3008 skb
= alloc_skb(NLMSG_GOODSIZE
, GFP_KERNEL
);
3014 /* Reserve room for dummy headers, this skb can pass
3015 through good chunk of routing engine.
3017 skb_reset_mac_header(skb
);
3018 skb_reset_network_header(skb
);
3020 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
3021 ip_hdr(skb
)->protocol
= IPPROTO_ICMP
;
3022 skb_reserve(skb
, MAX_HEADER
+ sizeof(struct iphdr
));
3024 src
= tb
[RTA_SRC
] ? nla_get_be32(tb
[RTA_SRC
]) : 0;
3025 dst
= tb
[RTA_DST
] ? nla_get_be32(tb
[RTA_DST
]) : 0;
3026 iif
= tb
[RTA_IIF
] ? nla_get_u32(tb
[RTA_IIF
]) : 0;
3027 mark
= tb
[RTA_MARK
] ? nla_get_u32(tb
[RTA_MARK
]) : 0;
3030 struct net_device
*dev
;
3032 dev
= __dev_get_by_index(net
, iif
);
3038 skb
->protocol
= htons(ETH_P_IP
);
3042 err
= ip_route_input(skb
, dst
, src
, rtm
->rtm_tos
, dev
);
3045 rt
= skb_rtable(skb
);
3046 if (err
== 0 && rt
->dst
.error
)
3047 err
= -rt
->dst
.error
;
3049 struct flowi4 fl4
= {
3052 .flowi4_tos
= rtm
->rtm_tos
,
3053 .flowi4_oif
= tb
[RTA_OIF
] ? nla_get_u32(tb
[RTA_OIF
]) : 0,
3054 .flowi4_mark
= mark
,
3056 rt
= ip_route_output_key(net
, &fl4
);
3066 skb_dst_set(skb
, &rt
->dst
);
3067 if (rtm
->rtm_flags
& RTM_F_NOTIFY
)
3068 rt
->rt_flags
|= RTCF_NOTIFY
;
3070 err
= rt_fill_info(net
, skb
, NETLINK_CB(in_skb
).pid
, nlh
->nlmsg_seq
,
3071 RTM_NEWROUTE
, 0, 0);
3075 err
= rtnl_unicast(skb
, net
, NETLINK_CB(in_skb
).pid
);
3084 int ip_rt_dump(struct sk_buff
*skb
, struct netlink_callback
*cb
)
3091 net
= sock_net(skb
->sk
);
3096 s_idx
= idx
= cb
->args
[1];
3097 for (h
= s_h
; h
<= rt_hash_mask
; h
++, s_idx
= 0) {
3098 if (!rt_hash_table
[h
].chain
)
3101 for (rt
= rcu_dereference_bh(rt_hash_table
[h
].chain
), idx
= 0; rt
;
3102 rt
= rcu_dereference_bh(rt
->dst
.rt_next
), idx
++) {
3103 if (!net_eq(dev_net(rt
->dst
.dev
), net
) || idx
< s_idx
)
3105 if (rt_is_expired(rt
))
3107 skb_dst_set_noref(skb
, &rt
->dst
);
3108 if (rt_fill_info(net
, skb
, NETLINK_CB(cb
->skb
).pid
,
3109 cb
->nlh
->nlmsg_seq
, RTM_NEWROUTE
,
3110 1, NLM_F_MULTI
) <= 0) {
3112 rcu_read_unlock_bh();
3117 rcu_read_unlock_bh();
3126 void ip_rt_multicast_event(struct in_device
*in_dev
)
3128 rt_cache_flush(dev_net(in_dev
->dev
), 0);
3131 #ifdef CONFIG_SYSCTL
3132 static int ipv4_sysctl_rtcache_flush(ctl_table
*__ctl
, int write
,
3133 void __user
*buffer
,
3134 size_t *lenp
, loff_t
*ppos
)
3141 memcpy(&ctl
, __ctl
, sizeof(ctl
));
3142 ctl
.data
= &flush_delay
;
3143 proc_dointvec(&ctl
, write
, buffer
, lenp
, ppos
);
3145 net
= (struct net
*)__ctl
->extra1
;
3146 rt_cache_flush(net
, flush_delay
);
3153 static ctl_table ipv4_route_table
[] = {
3155 .procname
= "gc_thresh",
3156 .data
= &ipv4_dst_ops
.gc_thresh
,
3157 .maxlen
= sizeof(int),
3159 .proc_handler
= proc_dointvec
,
3162 .procname
= "max_size",
3163 .data
= &ip_rt_max_size
,
3164 .maxlen
= sizeof(int),
3166 .proc_handler
= proc_dointvec
,
3169 /* Deprecated. Use gc_min_interval_ms */
3171 .procname
= "gc_min_interval",
3172 .data
= &ip_rt_gc_min_interval
,
3173 .maxlen
= sizeof(int),
3175 .proc_handler
= proc_dointvec_jiffies
,
3178 .procname
= "gc_min_interval_ms",
3179 .data
= &ip_rt_gc_min_interval
,
3180 .maxlen
= sizeof(int),
3182 .proc_handler
= proc_dointvec_ms_jiffies
,
3185 .procname
= "gc_timeout",
3186 .data
= &ip_rt_gc_timeout
,
3187 .maxlen
= sizeof(int),
3189 .proc_handler
= proc_dointvec_jiffies
,
3192 .procname
= "gc_interval",
3193 .data
= &ip_rt_gc_interval
,
3194 .maxlen
= sizeof(int),
3196 .proc_handler
= proc_dointvec_jiffies
,
3199 .procname
= "redirect_load",
3200 .data
= &ip_rt_redirect_load
,
3201 .maxlen
= sizeof(int),
3203 .proc_handler
= proc_dointvec
,
3206 .procname
= "redirect_number",
3207 .data
= &ip_rt_redirect_number
,
3208 .maxlen
= sizeof(int),
3210 .proc_handler
= proc_dointvec
,
3213 .procname
= "redirect_silence",
3214 .data
= &ip_rt_redirect_silence
,
3215 .maxlen
= sizeof(int),
3217 .proc_handler
= proc_dointvec
,
3220 .procname
= "error_cost",
3221 .data
= &ip_rt_error_cost
,
3222 .maxlen
= sizeof(int),
3224 .proc_handler
= proc_dointvec
,
3227 .procname
= "error_burst",
3228 .data
= &ip_rt_error_burst
,
3229 .maxlen
= sizeof(int),
3231 .proc_handler
= proc_dointvec
,
3234 .procname
= "gc_elasticity",
3235 .data
= &ip_rt_gc_elasticity
,
3236 .maxlen
= sizeof(int),
3238 .proc_handler
= proc_dointvec
,
3241 .procname
= "mtu_expires",
3242 .data
= &ip_rt_mtu_expires
,
3243 .maxlen
= sizeof(int),
3245 .proc_handler
= proc_dointvec_jiffies
,
3248 .procname
= "min_pmtu",
3249 .data
= &ip_rt_min_pmtu
,
3250 .maxlen
= sizeof(int),
3252 .proc_handler
= proc_dointvec
,
3255 .procname
= "min_adv_mss",
3256 .data
= &ip_rt_min_advmss
,
3257 .maxlen
= sizeof(int),
3259 .proc_handler
= proc_dointvec
,
3264 static struct ctl_table ipv4_route_flush_table
[] = {
3266 .procname
= "flush",
3267 .maxlen
= sizeof(int),
3269 .proc_handler
= ipv4_sysctl_rtcache_flush
,
3274 static __net_init
int sysctl_route_net_init(struct net
*net
)
3276 struct ctl_table
*tbl
;
3278 tbl
= ipv4_route_flush_table
;
3279 if (!net_eq(net
, &init_net
)) {
3280 tbl
= kmemdup(tbl
, sizeof(ipv4_route_flush_table
), GFP_KERNEL
);
3284 tbl
[0].extra1
= net
;
3286 net
->ipv4
.route_hdr
= register_net_sysctl(net
, "net/ipv4/route", tbl
);
3287 if (net
->ipv4
.route_hdr
== NULL
)
3292 if (tbl
!= ipv4_route_flush_table
)
3298 static __net_exit
void sysctl_route_net_exit(struct net
*net
)
3300 struct ctl_table
*tbl
;
3302 tbl
= net
->ipv4
.route_hdr
->ctl_table_arg
;
3303 unregister_net_sysctl_table(net
->ipv4
.route_hdr
);
3304 BUG_ON(tbl
== ipv4_route_flush_table
);
3308 static __net_initdata
struct pernet_operations sysctl_route_ops
= {
3309 .init
= sysctl_route_net_init
,
3310 .exit
= sysctl_route_net_exit
,
3314 static __net_init
int rt_genid_init(struct net
*net
)
3316 get_random_bytes(&net
->ipv4
.rt_genid
,
3317 sizeof(net
->ipv4
.rt_genid
));
3318 get_random_bytes(&net
->ipv4
.dev_addr_genid
,
3319 sizeof(net
->ipv4
.dev_addr_genid
));
3323 static __net_initdata
struct pernet_operations rt_genid_ops
= {
3324 .init
= rt_genid_init
,
3327 static int __net_init
ipv4_inetpeer_init(struct net
*net
)
3329 struct inet_peer_base
*bp
= kmalloc(sizeof(*bp
), GFP_KERNEL
);
3333 inet_peer_base_init(bp
);
3334 net
->ipv4
.peers
= bp
;
3338 static void __net_exit
ipv4_inetpeer_exit(struct net
*net
)
3340 struct inet_peer_base
*bp
= net
->ipv4
.peers
;
3342 net
->ipv4
.peers
= NULL
;
3343 inetpeer_invalidate_tree(bp
);
3347 static __net_initdata
struct pernet_operations ipv4_inetpeer_ops
= {
3348 .init
= ipv4_inetpeer_init
,
3349 .exit
= ipv4_inetpeer_exit
,
3352 #ifdef CONFIG_IP_ROUTE_CLASSID
3353 struct ip_rt_acct __percpu
*ip_rt_acct __read_mostly
;
3354 #endif /* CONFIG_IP_ROUTE_CLASSID */
3356 static __initdata
unsigned long rhash_entries
;
3357 static int __init
set_rhash_entries(char *str
)
3364 ret
= kstrtoul(str
, 0, &rhash_entries
);
3370 __setup("rhash_entries=", set_rhash_entries
);
3372 int __init
ip_rt_init(void)
3376 #ifdef CONFIG_IP_ROUTE_CLASSID
3377 ip_rt_acct
= __alloc_percpu(256 * sizeof(struct ip_rt_acct
), __alignof__(struct ip_rt_acct
));
3379 panic("IP: failed to allocate ip_rt_acct\n");
3382 ipv4_dst_ops
.kmem_cachep
=
3383 kmem_cache_create("ip_dst_cache", sizeof(struct rtable
), 0,
3384 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
3386 ipv4_dst_blackhole_ops
.kmem_cachep
= ipv4_dst_ops
.kmem_cachep
;
3388 if (dst_entries_init(&ipv4_dst_ops
) < 0)
3389 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3391 if (dst_entries_init(&ipv4_dst_blackhole_ops
) < 0)
3392 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3394 rt_hash_table
= (struct rt_hash_bucket
*)
3395 alloc_large_system_hash("IP route cache",
3396 sizeof(struct rt_hash_bucket
),
3398 (totalram_pages
>= 128 * 1024) ?
3404 rhash_entries
? 0 : 512 * 1024);
3405 memset(rt_hash_table
, 0, (rt_hash_mask
+ 1) * sizeof(struct rt_hash_bucket
));
3406 rt_hash_lock_init();
3408 ipv4_dst_ops
.gc_thresh
= (rt_hash_mask
+ 1);
3409 ip_rt_max_size
= (rt_hash_mask
+ 1) * 16;
3414 INIT_DELAYED_WORK_DEFERRABLE(&expires_work
, rt_worker_func
);
3415 expires_ljiffies
= jiffies
;
3416 schedule_delayed_work(&expires_work
,
3417 net_random() % ip_rt_gc_interval
+ ip_rt_gc_interval
);
3419 if (ip_rt_proc_init())
3420 pr_err("Unable to create route proc files\n");
3423 xfrm4_init(ip_rt_max_size
);
3425 rtnl_register(PF_INET
, RTM_GETROUTE
, inet_rtm_getroute
, NULL
, NULL
);
3427 #ifdef CONFIG_SYSCTL
3428 register_pernet_subsys(&sysctl_route_ops
);
3430 register_pernet_subsys(&rt_genid_ops
);
3431 register_pernet_subsys(&ipv4_inetpeer_ops
);
3435 #ifdef CONFIG_SYSCTL
3437 * We really need to sanitize the damn ipv4 init order, then all
3438 * this nonsense will go away.
3440 void __init
ip_static_sysctl_init(void)
3442 register_net_sysctl(&init_net
, "net/ipv4/route", ipv4_route_table
);