2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * ROUTE - implementation of the IP router.
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
65 #include <linux/module.h>
66 #include <asm/uaccess.h>
67 #include <asm/system.h>
68 #include <linux/bitops.h>
69 #include <linux/types.h>
70 #include <linux/kernel.h>
72 #include <linux/bootmem.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/workqueue.h>
83 #include <linux/skbuff.h>
84 #include <linux/inetdevice.h>
85 #include <linux/igmp.h>
86 #include <linux/pkt_sched.h>
87 #include <linux/mroute.h>
88 #include <linux/netfilter_ipv4.h>
89 #include <linux/random.h>
90 #include <linux/jhash.h>
91 #include <linux/rcupdate.h>
92 #include <linux/times.h>
93 #include <linux/slab.h>
95 #include <net/net_namespace.h>
96 #include <net/protocol.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/netevent.h>
107 #include <net/rtnetlink.h>
109 #include <linux/sysctl.h>
112 #define RT_FL_TOS(oldflp) \
113 ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
115 #define IP_MAX_MTU 0xFFF0
117 #define RT_GC_TIMEOUT (300*HZ)
119 static int ip_rt_max_size;
120 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
121 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
122 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
123 static int ip_rt_redirect_number __read_mostly = 9;
124 static int ip_rt_redirect_load __read_mostly = HZ / 50;
125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly = HZ;
127 static int ip_rt_error_burst __read_mostly = 5 * HZ;
128 static int ip_rt_gc_elasticity __read_mostly = 8;
129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
130 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly = 256;
132 static int rt_chain_length_max __read_mostly = 20;
134 static struct delayed_work expires_work;
135 static unsigned long expires_ljiffies;
138 * Interface to generic destination cache.
141 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
142 static void ipv4_dst_destroy(struct dst_entry *dst);
143 static void ipv4_dst_ifdown(struct dst_entry *dst,
144 struct net_device *dev, int how);
145 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
146 static void ipv4_link_failure(struct sk_buff *skb);
147 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
148 static int rt_garbage_collect(struct dst_ops *ops);
151 static struct dst_ops ipv4_dst_ops = {
153 .protocol = cpu_to_be16(ETH_P_IP),
154 .gc = rt_garbage_collect,
155 .check = ipv4_dst_check,
156 .destroy = ipv4_dst_destroy,
157 .ifdown = ipv4_dst_ifdown,
158 .negative_advice = ipv4_negative_advice,
159 .link_failure = ipv4_link_failure,
160 .update_pmtu = ip_rt_update_pmtu,
161 .local_out = __ip_local_out,
164 #define ECN_OR_COST(class) TC_PRIO_##class
166 const __u8 ip_tos2prio[16] = {
170 ECN_OR_COST(BESTEFFORT),
176 ECN_OR_COST(INTERACTIVE),
178 ECN_OR_COST(INTERACTIVE),
179 TC_PRIO_INTERACTIVE_BULK,
180 ECN_OR_COST(INTERACTIVE_BULK),
181 TC_PRIO_INTERACTIVE_BULK,
182 ECN_OR_COST(INTERACTIVE_BULK)
190 /* The locking scheme is rather straight forward:
192 * 1) Read-Copy Update protects the buckets of the central route hash.
193 * 2) Only writers remove entries, and they hold the lock
194 * as they look at rtable reference counts.
195 * 3) Only readers acquire references to rtable entries,
196 * they do so with atomic increments and with the
200 struct rt_hash_bucket {
201 struct rtable __rcu *chain;
204 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
205 defined(CONFIG_PROVE_LOCKING)
207 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
208 * The size of this table is a power of two and depends on the number of CPUS.
209 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
211 #ifdef CONFIG_LOCKDEP
212 # define RT_HASH_LOCK_SZ 256
215 # define RT_HASH_LOCK_SZ 4096
217 # define RT_HASH_LOCK_SZ 2048
219 # define RT_HASH_LOCK_SZ 1024
221 # define RT_HASH_LOCK_SZ 512
223 # define RT_HASH_LOCK_SZ 256
227 static spinlock_t *rt_hash_locks;
228 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
230 static __init void rt_hash_lock_init(void)
234 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
237 panic("IP: failed to allocate rt_hash_locks\n");
239 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
240 spin_lock_init(&rt_hash_locks[i]);
243 # define rt_hash_lock_addr(slot) NULL
245 static inline void rt_hash_lock_init(void)
250 static struct rt_hash_bucket *rt_hash_table __read_mostly;
251 static unsigned rt_hash_mask __read_mostly;
252 static unsigned int rt_hash_log __read_mostly;
254 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
255 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
257 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
260 return jhash_3words((__force u32)daddr, (__force u32)saddr,
265 static inline int rt_genid(struct net *net)
267 return atomic_read(&net->ipv4.rt_genid);
270 #ifdef CONFIG_PROC_FS
271 struct rt_cache_iter_state {
272 struct seq_net_private p;
277 static struct rtable *rt_cache_get_first(struct seq_file *seq)
279 struct rt_cache_iter_state *st = seq->private;
280 struct rtable *r = NULL;
282 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
283 if (!rcu_dereference_raw(rt_hash_table[st->bucket].chain))
286 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
288 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
289 r->rt_genid == st->genid)
291 r = rcu_dereference_bh(r->dst.rt_next);
293 rcu_read_unlock_bh();
298 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
301 struct rt_cache_iter_state *st = seq->private;
303 r = rcu_dereference_bh(r->dst.rt_next);
305 rcu_read_unlock_bh();
307 if (--st->bucket < 0)
309 } while (!rcu_dereference_raw(rt_hash_table[st->bucket].chain));
311 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
316 static struct rtable *rt_cache_get_next(struct seq_file *seq,
319 struct rt_cache_iter_state *st = seq->private;
320 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
321 if (dev_net(r->dst.dev) != seq_file_net(seq))
323 if (r->rt_genid == st->genid)
329 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
331 struct rtable *r = rt_cache_get_first(seq);
334 while (pos && (r = rt_cache_get_next(seq, r)))
336 return pos ? NULL : r;
339 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
341 struct rt_cache_iter_state *st = seq->private;
343 return rt_cache_get_idx(seq, *pos - 1);
344 st->genid = rt_genid(seq_file_net(seq));
345 return SEQ_START_TOKEN;
348 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
352 if (v == SEQ_START_TOKEN)
353 r = rt_cache_get_first(seq);
355 r = rt_cache_get_next(seq, v);
360 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
362 if (v && v != SEQ_START_TOKEN)
363 rcu_read_unlock_bh();
366 static int rt_cache_seq_show(struct seq_file *seq, void *v)
368 if (v == SEQ_START_TOKEN)
369 seq_printf(seq, "%-127s\n",
370 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
371 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
374 struct rtable *r = v;
377 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
378 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
379 r->dst.dev ? r->dst.dev->name : "*",
380 (__force u32)r->rt_dst,
381 (__force u32)r->rt_gateway,
382 r->rt_flags, atomic_read(&r->dst.__refcnt),
383 r->dst.__use, 0, (__force u32)r->rt_src,
384 (dst_metric(&r->dst, RTAX_ADVMSS) ?
385 (int)dst_metric(&r->dst, RTAX_ADVMSS) + 40 : 0),
386 dst_metric(&r->dst, RTAX_WINDOW),
387 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
388 dst_metric(&r->dst, RTAX_RTTVAR)),
390 r->dst.hh ? atomic_read(&r->dst.hh->hh_refcnt) : -1,
391 r->dst.hh ? (r->dst.hh->hh_output ==
393 r->rt_spec_dst, &len);
395 seq_printf(seq, "%*s\n", 127 - len, "");
400 static const struct seq_operations rt_cache_seq_ops = {
401 .start = rt_cache_seq_start,
402 .next = rt_cache_seq_next,
403 .stop = rt_cache_seq_stop,
404 .show = rt_cache_seq_show,
407 static int rt_cache_seq_open(struct inode *inode, struct file *file)
409 return seq_open_net(inode, file, &rt_cache_seq_ops,
410 sizeof(struct rt_cache_iter_state));
413 static const struct file_operations rt_cache_seq_fops = {
414 .owner = THIS_MODULE,
415 .open = rt_cache_seq_open,
418 .release = seq_release_net,
422 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
427 return SEQ_START_TOKEN;
429 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
430 if (!cpu_possible(cpu))
433 return &per_cpu(rt_cache_stat, cpu);
438 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
442 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
443 if (!cpu_possible(cpu))
446 return &per_cpu(rt_cache_stat, cpu);
452 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
457 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
459 struct rt_cache_stat *st = v;
461 if (v == SEQ_START_TOKEN) {
462 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");
466 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
467 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
468 dst_entries_get_slow(&ipv4_dst_ops),
491 static const struct seq_operations rt_cpu_seq_ops = {
492 .start = rt_cpu_seq_start,
493 .next = rt_cpu_seq_next,
494 .stop = rt_cpu_seq_stop,
495 .show = rt_cpu_seq_show,
499 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
501 return seq_open(file, &rt_cpu_seq_ops);
504 static const struct file_operations rt_cpu_seq_fops = {
505 .owner = THIS_MODULE,
506 .open = rt_cpu_seq_open,
509 .release = seq_release,
512 #ifdef CONFIG_NET_CLS_ROUTE
513 static int rt_acct_proc_show(struct seq_file *m, void *v)
515 struct ip_rt_acct *dst, *src;
518 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
522 for_each_possible_cpu(i) {
523 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
524 for (j = 0; j < 256; j++) {
525 dst[j].o_bytes += src[j].o_bytes;
526 dst[j].o_packets += src[j].o_packets;
527 dst[j].i_bytes += src[j].i_bytes;
528 dst[j].i_packets += src[j].i_packets;
532 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
537 static int rt_acct_proc_open(struct inode *inode, struct file *file)
539 return single_open(file, rt_acct_proc_show, NULL);
542 static const struct file_operations rt_acct_proc_fops = {
543 .owner = THIS_MODULE,
544 .open = rt_acct_proc_open,
547 .release = single_release,
551 static int __net_init ip_rt_do_proc_init(struct net *net)
553 struct proc_dir_entry *pde;
555 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
560 pde = proc_create("rt_cache", S_IRUGO,
561 net->proc_net_stat, &rt_cpu_seq_fops);
565 #ifdef CONFIG_NET_CLS_ROUTE
566 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
572 #ifdef CONFIG_NET_CLS_ROUTE
574 remove_proc_entry("rt_cache", net->proc_net_stat);
577 remove_proc_entry("rt_cache", net->proc_net);
582 static void __net_exit ip_rt_do_proc_exit(struct net *net)
584 remove_proc_entry("rt_cache", net->proc_net_stat);
585 remove_proc_entry("rt_cache", net->proc_net);
586 #ifdef CONFIG_NET_CLS_ROUTE
587 remove_proc_entry("rt_acct", net->proc_net);
591 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
592 .init = ip_rt_do_proc_init,
593 .exit = ip_rt_do_proc_exit,
596 static int __init ip_rt_proc_init(void)
598 return register_pernet_subsys(&ip_rt_proc_ops);
602 static inline int ip_rt_proc_init(void)
606 #endif /* CONFIG_PROC_FS */
608 static inline void rt_free(struct rtable *rt)
610 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
613 static inline void rt_drop(struct rtable *rt)
616 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
619 static inline int rt_fast_clean(struct rtable *rth)
621 /* Kill broadcast/multicast entries very aggresively, if they
622 collide in hash table with more useful entries */
623 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
624 rth->fl.iif && rth->dst.rt_next;
627 static inline int rt_valuable(struct rtable *rth)
629 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
633 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
638 if (atomic_read(&rth->dst.__refcnt))
642 if (rth->dst.expires &&
643 time_after_eq(jiffies, rth->dst.expires))
646 age = jiffies - rth->dst.lastuse;
648 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
649 (age <= tmo2 && rt_valuable(rth)))
655 /* Bits of score are:
657 * 30: not quite useless
658 * 29..0: usage counter
660 static inline u32 rt_score(struct rtable *rt)
662 u32 score = jiffies - rt->dst.lastuse;
664 score = ~score & ~(3<<30);
670 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
676 static inline bool rt_caching(const struct net *net)
678 return net->ipv4.current_rt_cache_rebuild_count <=
679 net->ipv4.sysctl_rt_cache_rebuild_count;
682 static inline bool compare_hash_inputs(const struct flowi *fl1,
683 const struct flowi *fl2)
685 return ((((__force u32)fl1->nl_u.ip4_u.daddr ^ (__force u32)fl2->nl_u.ip4_u.daddr) |
686 ((__force u32)fl1->nl_u.ip4_u.saddr ^ (__force u32)fl2->nl_u.ip4_u.saddr) |
687 (fl1->iif ^ fl2->iif)) == 0);
690 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
692 return (((__force u32)fl1->nl_u.ip4_u.daddr ^ (__force u32)fl2->nl_u.ip4_u.daddr) |
693 ((__force u32)fl1->nl_u.ip4_u.saddr ^ (__force u32)fl2->nl_u.ip4_u.saddr) |
694 (fl1->mark ^ fl2->mark) |
695 (*(u16 *)&fl1->nl_u.ip4_u.tos ^ *(u16 *)&fl2->nl_u.ip4_u.tos) |
696 (fl1->oif ^ fl2->oif) |
697 (fl1->iif ^ fl2->iif)) == 0;
700 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
702 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
705 static inline int rt_is_expired(struct rtable *rth)
707 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
711 * Perform a full scan of hash table and free all entries.
712 * Can be called by a softirq or a process.
713 * In the later case, we want to be reschedule if necessary
715 static void rt_do_flush(int process_context)
718 struct rtable *rth, *next;
719 struct rtable * tail;
721 for (i = 0; i <= rt_hash_mask; i++) {
722 if (process_context && need_resched())
724 rth = rcu_dereference_raw(rt_hash_table[i].chain);
728 spin_lock_bh(rt_hash_lock_addr(i));
731 struct rtable __rcu **prev;
734 rth = rcu_dereference_protected(rt_hash_table[i].chain,
735 lockdep_is_held(rt_hash_lock_addr(i)));
737 /* defer releasing the head of the list after spin_unlock */
738 for (tail = rth; tail;
739 tail = rcu_dereference_protected(tail->dst.rt_next,
740 lockdep_is_held(rt_hash_lock_addr(i))))
741 if (!rt_is_expired(tail))
744 rt_hash_table[i].chain = tail;
746 /* call rt_free on entries after the tail requiring flush */
747 prev = &rt_hash_table[i].chain;
748 for (p = rcu_dereference_protected(*prev,
749 lockdep_is_held(rt_hash_lock_addr(i)));
752 next = rcu_dereference_protected(p->dst.rt_next,
753 lockdep_is_held(rt_hash_lock_addr(i)));
754 if (!rt_is_expired(p)) {
755 prev = &p->dst.rt_next;
763 rth = rcu_dereference_protected(rt_hash_table[i].chain,
764 lockdep_is_held(rt_hash_lock_addr(i)));
765 rcu_assign_pointer(rt_hash_table[i].chain, NULL);
768 spin_unlock_bh(rt_hash_lock_addr(i));
770 for (; rth != tail; rth = next) {
771 next = rcu_dereference_protected(rth->dst.rt_next, 1);
778 * While freeing expired entries, we compute average chain length
779 * and standard deviation, using fixed-point arithmetic.
780 * This to have an estimation of rt_chain_length_max
781 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
782 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
786 #define ONE (1UL << FRACT_BITS)
789 * Given a hash chain and an item in this hash chain,
790 * find if a previous entry has the same hash_inputs
791 * (but differs on tos, mark or oif)
792 * Returns 0 if an alias is found.
793 * Returns ONE if rth has no alias before itself.
795 static int has_noalias(const struct rtable *head, const struct rtable *rth)
797 const struct rtable *aux = head;
800 if (compare_hash_inputs(&aux->fl, &rth->fl))
802 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
807 static void rt_check_expire(void)
809 static unsigned int rover;
810 unsigned int i = rover, goal;
812 struct rtable __rcu **rthp;
813 unsigned long samples = 0;
814 unsigned long sum = 0, sum2 = 0;
818 delta = jiffies - expires_ljiffies;
819 expires_ljiffies = jiffies;
820 mult = ((u64)delta) << rt_hash_log;
821 if (ip_rt_gc_timeout > 1)
822 do_div(mult, ip_rt_gc_timeout);
823 goal = (unsigned int)mult;
824 if (goal > rt_hash_mask)
825 goal = rt_hash_mask + 1;
826 for (; goal > 0; goal--) {
827 unsigned long tmo = ip_rt_gc_timeout;
828 unsigned long length;
830 i = (i + 1) & rt_hash_mask;
831 rthp = &rt_hash_table[i].chain;
838 if (rcu_dereference_raw(*rthp) == NULL)
841 spin_lock_bh(rt_hash_lock_addr(i));
842 while ((rth = rcu_dereference_protected(*rthp,
843 lockdep_is_held(rt_hash_lock_addr(i)))) != NULL) {
844 prefetch(rth->dst.rt_next);
845 if (rt_is_expired(rth)) {
846 *rthp = rth->dst.rt_next;
850 if (rth->dst.expires) {
851 /* Entry is expired even if it is in use */
852 if (time_before_eq(jiffies, rth->dst.expires)) {
855 rthp = &rth->dst.rt_next;
857 * We only count entries on
858 * a chain with equal hash inputs once
859 * so that entries for different QOS
860 * levels, and other non-hash input
861 * attributes don't unfairly skew
862 * the length computation
864 length += has_noalias(rt_hash_table[i].chain, rth);
867 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout))
870 /* Cleanup aged off entries. */
871 *rthp = rth->dst.rt_next;
874 spin_unlock_bh(rt_hash_lock_addr(i));
876 sum2 += length*length;
879 unsigned long avg = sum / samples;
880 unsigned long sd = int_sqrt(sum2 / samples - avg*avg);
881 rt_chain_length_max = max_t(unsigned long,
883 (avg + 4*sd) >> FRACT_BITS);
889 * rt_worker_func() is run in process context.
890 * we call rt_check_expire() to scan part of the hash table
892 static void rt_worker_func(struct work_struct *work)
895 schedule_delayed_work(&expires_work, ip_rt_gc_interval);
899 * Pertubation of rt_genid by a small quantity [1..256]
900 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
901 * many times (2^24) without giving recent rt_genid.
902 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
904 static void rt_cache_invalidate(struct net *net)
906 unsigned char shuffle;
908 get_random_bytes(&shuffle, sizeof(shuffle));
909 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
913 * delay < 0 : invalidate cache (fast : entries will be deleted later)
914 * delay >= 0 : invalidate & flush cache (can be long)
916 void rt_cache_flush(struct net *net, int delay)
918 rt_cache_invalidate(net);
920 rt_do_flush(!in_softirq());
923 /* Flush previous cache invalidated entries from the cache */
924 void rt_cache_flush_batch(void)
926 rt_do_flush(!in_softirq());
929 static void rt_emergency_hash_rebuild(struct net *net)
932 printk(KERN_WARNING "Route hash chain too long!\n");
933 rt_cache_invalidate(net);
937 Short description of GC goals.
939 We want to build algorithm, which will keep routing cache
940 at some equilibrium point, when number of aged off entries
941 is kept approximately equal to newly generated ones.
943 Current expiration strength is variable "expire".
944 We try to adjust it dynamically, so that if networking
945 is idle expires is large enough to keep enough of warm entries,
946 and when load increases it reduces to limit cache size.
949 static int rt_garbage_collect(struct dst_ops *ops)
951 static unsigned long expire = RT_GC_TIMEOUT;
952 static unsigned long last_gc;
954 static int equilibrium;
956 struct rtable __rcu **rthp;
957 unsigned long now = jiffies;
959 int entries = dst_entries_get_fast(&ipv4_dst_ops);
962 * Garbage collection is pretty expensive,
963 * do not make it too frequently.
966 RT_CACHE_STAT_INC(gc_total);
968 if (now - last_gc < ip_rt_gc_min_interval &&
969 entries < ip_rt_max_size) {
970 RT_CACHE_STAT_INC(gc_ignored);
974 entries = dst_entries_get_slow(&ipv4_dst_ops);
975 /* Calculate number of entries, which we want to expire now. */
976 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
978 if (equilibrium < ipv4_dst_ops.gc_thresh)
979 equilibrium = ipv4_dst_ops.gc_thresh;
980 goal = entries - equilibrium;
982 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
983 goal = entries - equilibrium;
986 /* We are in dangerous area. Try to reduce cache really
989 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
990 equilibrium = entries - goal;
993 if (now - last_gc >= ip_rt_gc_min_interval)
1004 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
1005 unsigned long tmo = expire;
1007 k = (k + 1) & rt_hash_mask;
1008 rthp = &rt_hash_table[k].chain;
1009 spin_lock_bh(rt_hash_lock_addr(k));
1010 while ((rth = rcu_dereference_protected(*rthp,
1011 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
1012 if (!rt_is_expired(rth) &&
1013 !rt_may_expire(rth, tmo, expire)) {
1015 rthp = &rth->dst.rt_next;
1018 *rthp = rth->dst.rt_next;
1022 spin_unlock_bh(rt_hash_lock_addr(k));
1031 /* Goal is not achieved. We stop process if:
1033 - if expire reduced to zero. Otherwise, expire is halfed.
1034 - if table is not full.
1035 - if we are called from interrupt.
1036 - jiffies check is just fallback/debug loop breaker.
1037 We will not spin here for long time in any case.
1040 RT_CACHE_STAT_INC(gc_goal_miss);
1046 #if RT_CACHE_DEBUG >= 2
1047 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
1048 dst_entries_get_fast(&ipv4_dst_ops), goal, i);
1051 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
1053 } while (!in_softirq() && time_before_eq(jiffies, now));
1055 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
1057 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
1059 if (net_ratelimit())
1060 printk(KERN_WARNING "dst cache overflow\n");
1061 RT_CACHE_STAT_INC(gc_dst_overflow);
1065 expire += ip_rt_gc_min_interval;
1066 if (expire > ip_rt_gc_timeout ||
1067 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
1068 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
1069 expire = ip_rt_gc_timeout;
1070 #if RT_CACHE_DEBUG >= 2
1071 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
1072 dst_entries_get_fast(&ipv4_dst_ops), goal, rover);
1078 * Returns number of entries in a hash chain that have different hash_inputs
1080 static int slow_chain_length(const struct rtable *head)
1083 const struct rtable *rth = head;
1086 length += has_noalias(head, rth);
1087 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1089 return length >> FRACT_BITS;
1092 static int rt_intern_hash(unsigned hash, struct rtable *rt,
1093 struct rtable **rp, struct sk_buff *skb, int ifindex)
1095 struct rtable *rth, *cand;
1096 struct rtable __rcu **rthp, **candp;
1100 int attempts = !in_softirq();
1104 min_score = ~(u32)0;
1109 if (!rt_caching(dev_net(rt->dst.dev))) {
1111 * If we're not caching, just tell the caller we
1112 * were successful and don't touch the route. The
1113 * caller hold the sole reference to the cache entry, and
1114 * it will be released when the caller is done with it.
1115 * If we drop it here, the callers have no way to resolve routes
1116 * when we're not caching. Instead, just point *rp at rt, so
1117 * the caller gets a single use out of the route
1118 * Note that we do rt_free on this new route entry, so that
1119 * once its refcount hits zero, we are still able to reap it
1121 * Note: To avoid expensive rcu stuff for this uncached dst,
1122 * we set DST_NOCACHE so that dst_release() can free dst without
1123 * waiting a grace period.
1126 rt->dst.flags |= DST_NOCACHE;
1127 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1128 int err = arp_bind_neighbour(&rt->dst);
1130 if (net_ratelimit())
1132 "Neighbour table failure & not caching routes.\n");
1141 rthp = &rt_hash_table[hash].chain;
1143 spin_lock_bh(rt_hash_lock_addr(hash));
1144 while ((rth = rcu_dereference_protected(*rthp,
1145 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1146 if (rt_is_expired(rth)) {
1147 *rthp = rth->dst.rt_next;
1151 if (compare_keys(&rth->fl, &rt->fl) && compare_netns(rth, rt)) {
1153 *rthp = rth->dst.rt_next;
1155 * Since lookup is lockfree, the deletion
1156 * must be visible to another weakly ordered CPU before
1157 * the insertion at the start of the hash chain.
1159 rcu_assign_pointer(rth->dst.rt_next,
1160 rt_hash_table[hash].chain);
1162 * Since lookup is lockfree, the update writes
1163 * must be ordered for consistency on SMP.
1165 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1167 dst_use(&rth->dst, now);
1168 spin_unlock_bh(rt_hash_lock_addr(hash));
1174 skb_dst_set(skb, &rth->dst);
1178 if (!atomic_read(&rth->dst.__refcnt)) {
1179 u32 score = rt_score(rth);
1181 if (score <= min_score) {
1190 rthp = &rth->dst.rt_next;
1194 /* ip_rt_gc_elasticity used to be average length of chain
1195 * length, when exceeded gc becomes really aggressive.
1197 * The second limit is less certain. At the moment it allows
1198 * only 2 entries per bucket. We will see.
1200 if (chain_length > ip_rt_gc_elasticity) {
1201 *candp = cand->dst.rt_next;
1205 if (chain_length > rt_chain_length_max &&
1206 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1207 struct net *net = dev_net(rt->dst.dev);
1208 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1209 if (!rt_caching(net)) {
1210 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1211 rt->dst.dev->name, num);
1213 rt_emergency_hash_rebuild(net);
1214 spin_unlock_bh(rt_hash_lock_addr(hash));
1216 hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1217 ifindex, rt_genid(net));
1222 /* Try to bind route to arp only if it is output
1223 route or unicast forwarding path.
1225 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1226 int err = arp_bind_neighbour(&rt->dst);
1228 spin_unlock_bh(rt_hash_lock_addr(hash));
1230 if (err != -ENOBUFS) {
1235 /* Neighbour tables are full and nothing
1236 can be released. Try to shrink route cache,
1237 it is most likely it holds some neighbour records.
1239 if (attempts-- > 0) {
1240 int saved_elasticity = ip_rt_gc_elasticity;
1241 int saved_int = ip_rt_gc_min_interval;
1242 ip_rt_gc_elasticity = 1;
1243 ip_rt_gc_min_interval = 0;
1244 rt_garbage_collect(&ipv4_dst_ops);
1245 ip_rt_gc_min_interval = saved_int;
1246 ip_rt_gc_elasticity = saved_elasticity;
1250 if (net_ratelimit())
1251 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1257 rt->dst.rt_next = rt_hash_table[hash].chain;
1259 #if RT_CACHE_DEBUG >= 2
1260 if (rt->dst.rt_next) {
1262 printk(KERN_DEBUG "rt_cache @%02x: %pI4",
1264 for (trt = rt->dst.rt_next; trt; trt = trt->dst.rt_next)
1265 printk(" . %pI4", &trt->rt_dst);
1270 * Since lookup is lockfree, we must make sure
1271 * previous writes to rt are comitted to memory
1272 * before making rt visible to other CPUS.
1274 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1276 spin_unlock_bh(rt_hash_lock_addr(hash));
1282 skb_dst_set(skb, &rt->dst);
1286 void rt_bind_peer(struct rtable *rt, int create)
1288 struct inet_peer *peer;
1290 peer = inet_getpeer(rt->rt_dst, create);
1292 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1297 * Peer allocation may fail only in serious out-of-memory conditions. However
1298 * we still can generate some output.
1299 * Random ID selection looks a bit dangerous because we have no chances to
1300 * select ID being unique in a reasonable period of time.
1301 * But broken packet identifier may be better than no packet at all.
1303 static void ip_select_fb_ident(struct iphdr *iph)
1305 static DEFINE_SPINLOCK(ip_fb_id_lock);
1306 static u32 ip_fallback_id;
1309 spin_lock_bh(&ip_fb_id_lock);
1310 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1311 iph->id = htons(salt & 0xFFFF);
1312 ip_fallback_id = salt;
1313 spin_unlock_bh(&ip_fb_id_lock);
1316 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1318 struct rtable *rt = (struct rtable *) dst;
1321 if (rt->peer == NULL)
1322 rt_bind_peer(rt, 1);
1324 /* If peer is attached to destination, it is never detached,
1325 so that we need not to grab a lock to dereference it.
1328 iph->id = htons(inet_getid(rt->peer, more));
1332 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1333 __builtin_return_address(0));
1335 ip_select_fb_ident(iph);
1337 EXPORT_SYMBOL(__ip_select_ident);
1339 static void rt_del(unsigned hash, struct rtable *rt)
1341 struct rtable __rcu **rthp;
1344 rthp = &rt_hash_table[hash].chain;
1345 spin_lock_bh(rt_hash_lock_addr(hash));
1347 while ((aux = rcu_dereference_protected(*rthp,
1348 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1349 if (aux == rt || rt_is_expired(aux)) {
1350 *rthp = aux->dst.rt_next;
1354 rthp = &aux->dst.rt_next;
1356 spin_unlock_bh(rt_hash_lock_addr(hash));
1359 /* called in rcu_read_lock() section */
1360 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1361 __be32 saddr, struct net_device *dev)
1364 struct in_device *in_dev = __in_dev_get_rcu(dev);
1366 struct rtable __rcu **rthp;
1367 __be32 skeys[2] = { saddr, 0 };
1368 int ikeys[2] = { dev->ifindex, 0 };
1369 struct netevent_redirect netevent;
1376 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1377 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1378 ipv4_is_zeronet(new_gw))
1379 goto reject_redirect;
1381 if (!rt_caching(net))
1382 goto reject_redirect;
1384 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1385 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1386 goto reject_redirect;
1387 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1388 goto reject_redirect;
1390 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1391 goto reject_redirect;
1394 for (i = 0; i < 2; i++) {
1395 for (k = 0; k < 2; k++) {
1396 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1399 rthp = &rt_hash_table[hash].chain;
1401 while ((rth = rcu_dereference(*rthp)) != NULL) {
1404 if (rth->fl.fl4_dst != daddr ||
1405 rth->fl.fl4_src != skeys[i] ||
1406 rth->fl.oif != ikeys[k] ||
1408 rt_is_expired(rth) ||
1409 !net_eq(dev_net(rth->dst.dev), net)) {
1410 rthp = &rth->dst.rt_next;
1414 if (rth->rt_dst != daddr ||
1415 rth->rt_src != saddr ||
1417 rth->rt_gateway != old_gw ||
1418 rth->dst.dev != dev)
1421 dst_hold(&rth->dst);
1423 rt = dst_alloc(&ipv4_dst_ops);
1429 /* Copy all the information. */
1432 atomic_set(&rt->dst.__refcnt, 1);
1433 rt->dst.child = NULL;
1435 dev_hold(rt->dst.dev);
1437 in_dev_hold(rt->idev);
1438 rt->dst.obsolete = -1;
1439 rt->dst.lastuse = jiffies;
1440 rt->dst.path = &rt->dst;
1441 rt->dst.neighbour = NULL;
1444 rt->dst.xfrm = NULL;
1446 rt->rt_genid = rt_genid(net);
1447 rt->rt_flags |= RTCF_REDIRECTED;
1449 /* Gateway is different ... */
1450 rt->rt_gateway = new_gw;
1452 /* Redirect received -> path was valid */
1453 dst_confirm(&rth->dst);
1456 atomic_inc(&rt->peer->refcnt);
1458 if (arp_bind_neighbour(&rt->dst) ||
1459 !(rt->dst.neighbour->nud_state &
1461 if (rt->dst.neighbour)
1462 neigh_event_send(rt->dst.neighbour, NULL);
1468 netevent.old = &rth->dst;
1469 netevent.new = &rt->dst;
1470 call_netevent_notifiers(NETEVENT_REDIRECT,
1474 if (!rt_intern_hash(hash, rt, &rt, NULL, rt->fl.oif))
1485 #ifdef CONFIG_IP_ROUTE_VERBOSE
1486 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1487 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1488 " Advised path = %pI4 -> %pI4\n",
1489 &old_gw, dev->name, &new_gw,
1495 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1497 struct rtable *rt = (struct rtable *)dst;
1498 struct dst_entry *ret = dst;
1501 if (dst->obsolete > 0) {
1504 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
1506 time_after_eq(jiffies, rt->dst.expires))) {
1507 unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1509 rt_genid(dev_net(dst->dev)));
1510 #if RT_CACHE_DEBUG >= 1
1511 printk(KERN_DEBUG "ipv4_negative_advice: redirect to %pI4/%02x dropped\n",
1512 &rt->rt_dst, rt->fl.fl4_tos);
1523 * 1. The first ip_rt_redirect_number redirects are sent
1524 * with exponential backoff, then we stop sending them at all,
1525 * assuming that the host ignores our redirects.
1526 * 2. If we did not see packets requiring redirects
1527 * during ip_rt_redirect_silence, we assume that the host
1528 * forgot redirected route and start to send redirects again.
1530 * This algorithm is much cheaper and more intelligent than dumb load limiting
1533 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1534 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1537 void ip_rt_send_redirect(struct sk_buff *skb)
1539 struct rtable *rt = skb_rtable(skb);
1540 struct in_device *in_dev;
1544 in_dev = __in_dev_get_rcu(rt->dst.dev);
1545 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1549 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1552 /* No redirected packets during ip_rt_redirect_silence;
1553 * reset the algorithm.
1555 if (time_after(jiffies, rt->dst.rate_last + ip_rt_redirect_silence))
1556 rt->dst.rate_tokens = 0;
1558 /* Too many ignored redirects; do not send anything
1559 * set dst.rate_last to the last seen redirected packet.
1561 if (rt->dst.rate_tokens >= ip_rt_redirect_number) {
1562 rt->dst.rate_last = jiffies;
1566 /* Check for load limit; set rate_last to the latest sent
1569 if (rt->dst.rate_tokens == 0 ||
1571 (rt->dst.rate_last +
1572 (ip_rt_redirect_load << rt->dst.rate_tokens)))) {
1573 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1574 rt->dst.rate_last = jiffies;
1575 ++rt->dst.rate_tokens;
1576 #ifdef CONFIG_IP_ROUTE_VERBOSE
1578 rt->dst.rate_tokens == ip_rt_redirect_number &&
1580 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1581 &rt->rt_src, rt->rt_iif,
1582 &rt->rt_dst, &rt->rt_gateway);
1587 static int ip_error(struct sk_buff *skb)
1589 struct rtable *rt = skb_rtable(skb);
1593 switch (rt->dst.error) {
1598 code = ICMP_HOST_UNREACH;
1601 code = ICMP_NET_UNREACH;
1602 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1603 IPSTATS_MIB_INNOROUTES);
1606 code = ICMP_PKT_FILTERED;
1611 rt->dst.rate_tokens += now - rt->dst.rate_last;
1612 if (rt->dst.rate_tokens > ip_rt_error_burst)
1613 rt->dst.rate_tokens = ip_rt_error_burst;
1614 rt->dst.rate_last = now;
1615 if (rt->dst.rate_tokens >= ip_rt_error_cost) {
1616 rt->dst.rate_tokens -= ip_rt_error_cost;
1617 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1620 out: kfree_skb(skb);
1625 * The last two values are not from the RFC but
1626 * are needed for AMPRnet AX.25 paths.
1629 static const unsigned short mtu_plateau[] =
1630 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1632 static inline unsigned short guess_mtu(unsigned short old_mtu)
1636 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1637 if (old_mtu > mtu_plateau[i])
1638 return mtu_plateau[i];
1642 unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
1643 unsigned short new_mtu,
1644 struct net_device *dev)
1647 unsigned short old_mtu = ntohs(iph->tot_len);
1649 int ikeys[2] = { dev->ifindex, 0 };
1650 __be32 skeys[2] = { iph->saddr, 0, };
1651 __be32 daddr = iph->daddr;
1652 unsigned short est_mtu = 0;
1654 for (k = 0; k < 2; k++) {
1655 for (i = 0; i < 2; i++) {
1656 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1660 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1661 rth = rcu_dereference(rth->dst.rt_next)) {
1662 unsigned short mtu = new_mtu;
1664 if (rth->fl.fl4_dst != daddr ||
1665 rth->fl.fl4_src != skeys[i] ||
1666 rth->rt_dst != daddr ||
1667 rth->rt_src != iph->saddr ||
1668 rth->fl.oif != ikeys[k] ||
1670 dst_metric_locked(&rth->dst, RTAX_MTU) ||
1671 !net_eq(dev_net(rth->dst.dev), net) ||
1675 if (new_mtu < 68 || new_mtu >= old_mtu) {
1677 /* BSD 4.2 compatibility hack :-( */
1679 old_mtu >= dst_mtu(&rth->dst) &&
1680 old_mtu >= 68 + (iph->ihl << 2))
1681 old_mtu -= iph->ihl << 2;
1683 mtu = guess_mtu(old_mtu);
1685 if (mtu <= dst_mtu(&rth->dst)) {
1686 if (mtu < dst_mtu(&rth->dst)) {
1687 dst_confirm(&rth->dst);
1688 if (mtu < ip_rt_min_pmtu) {
1689 mtu = ip_rt_min_pmtu;
1690 rth->dst.metrics[RTAX_LOCK-1] |=
1693 rth->dst.metrics[RTAX_MTU-1] = mtu;
1694 dst_set_expires(&rth->dst,
1703 return est_mtu ? : new_mtu;
1706 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1708 if (dst_mtu(dst) > mtu && mtu >= 68 &&
1709 !(dst_metric_locked(dst, RTAX_MTU))) {
1710 if (mtu < ip_rt_min_pmtu) {
1711 mtu = ip_rt_min_pmtu;
1712 dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
1714 dst->metrics[RTAX_MTU-1] = mtu;
1715 dst_set_expires(dst, ip_rt_mtu_expires);
1716 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
1720 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1722 if (rt_is_expired((struct rtable *)dst))
1727 static void ipv4_dst_destroy(struct dst_entry *dst)
1729 struct rtable *rt = (struct rtable *) dst;
1730 struct inet_peer *peer = rt->peer;
1731 struct in_device *idev = rt->idev;
1744 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
1747 struct rtable *rt = (struct rtable *) dst;
1748 struct in_device *idev = rt->idev;
1749 if (dev != dev_net(dev)->loopback_dev && idev && idev->dev == dev) {
1750 struct in_device *loopback_idev =
1751 in_dev_get(dev_net(dev)->loopback_dev);
1752 if (loopback_idev) {
1753 rt->idev = loopback_idev;
1759 static void ipv4_link_failure(struct sk_buff *skb)
1763 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1765 rt = skb_rtable(skb);
1767 dst_set_expires(&rt->dst, 0);
1770 static int ip_rt_bug(struct sk_buff *skb)
1772 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1773 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1774 skb->dev ? skb->dev->name : "?");
1780 We do not cache source address of outgoing interface,
1781 because it is used only by IP RR, TS and SRR options,
1782 so that it out of fast path.
1784 BTW remember: "addr" is allowed to be not aligned
1788 void ip_rt_get_source(u8 *addr, struct rtable *rt)
1791 struct fib_result res;
1793 if (rt->fl.iif == 0)
1797 if (fib_lookup(dev_net(rt->dst.dev), &rt->fl, &res) == 0)
1798 src = FIB_RES_PREFSRC(res);
1800 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1804 memcpy(addr, &src, 4);
1807 #ifdef CONFIG_NET_CLS_ROUTE
1808 static void set_class_tag(struct rtable *rt, u32 tag)
1810 if (!(rt->dst.tclassid & 0xFFFF))
1811 rt->dst.tclassid |= tag & 0xFFFF;
1812 if (!(rt->dst.tclassid & 0xFFFF0000))
1813 rt->dst.tclassid |= tag & 0xFFFF0000;
1817 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
1819 struct fib_info *fi = res->fi;
1822 if (FIB_RES_GW(*res) &&
1823 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1824 rt->rt_gateway = FIB_RES_GW(*res);
1825 memcpy(rt->dst.metrics, fi->fib_metrics,
1826 sizeof(rt->dst.metrics));
1827 if (fi->fib_mtu == 0) {
1828 rt->dst.metrics[RTAX_MTU-1] = rt->dst.dev->mtu;
1829 if (dst_metric_locked(&rt->dst, RTAX_MTU) &&
1830 rt->rt_gateway != rt->rt_dst &&
1831 rt->dst.dev->mtu > 576)
1832 rt->dst.metrics[RTAX_MTU-1] = 576;
1834 #ifdef CONFIG_NET_CLS_ROUTE
1835 rt->dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
1838 rt->dst.metrics[RTAX_MTU-1]= rt->dst.dev->mtu;
1840 if (dst_metric(&rt->dst, RTAX_HOPLIMIT) == 0)
1841 rt->dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
1842 if (dst_mtu(&rt->dst) > IP_MAX_MTU)
1843 rt->dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
1844 if (dst_metric(&rt->dst, RTAX_ADVMSS) == 0)
1845 rt->dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->dst.dev->mtu - 40,
1847 if (dst_metric(&rt->dst, RTAX_ADVMSS) > 65535 - 40)
1848 rt->dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
1850 #ifdef CONFIG_NET_CLS_ROUTE
1851 #ifdef CONFIG_IP_MULTIPLE_TABLES
1852 set_class_tag(rt, fib_rules_tclass(res));
1854 set_class_tag(rt, itag);
1856 rt->rt_type = res->type;
1859 /* called in rcu_read_lock() section */
1860 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1861 u8 tos, struct net_device *dev, int our)
1866 struct in_device *in_dev = __in_dev_get_rcu(dev);
1870 /* Primary sanity checks. */
1875 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1876 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1879 if (ipv4_is_zeronet(saddr)) {
1880 if (!ipv4_is_local_multicast(daddr))
1882 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1884 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
1889 rth = dst_alloc(&ipv4_dst_ops);
1893 rth->dst.output = ip_rt_bug;
1894 rth->dst.obsolete = -1;
1896 atomic_set(&rth->dst.__refcnt, 1);
1897 rth->dst.flags= DST_HOST;
1898 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1899 rth->dst.flags |= DST_NOPOLICY;
1900 rth->fl.fl4_dst = daddr;
1901 rth->rt_dst = daddr;
1902 rth->fl.fl4_tos = tos;
1903 rth->fl.mark = skb->mark;
1904 rth->fl.fl4_src = saddr;
1905 rth->rt_src = saddr;
1906 #ifdef CONFIG_NET_CLS_ROUTE
1907 rth->dst.tclassid = itag;
1910 rth->fl.iif = dev->ifindex;
1911 rth->dst.dev = init_net.loopback_dev;
1912 dev_hold(rth->dst.dev);
1913 rth->idev = in_dev_get(rth->dst.dev);
1915 rth->rt_gateway = daddr;
1916 rth->rt_spec_dst= spec_dst;
1917 rth->rt_genid = rt_genid(dev_net(dev));
1918 rth->rt_flags = RTCF_MULTICAST;
1919 rth->rt_type = RTN_MULTICAST;
1921 rth->dst.input= ip_local_deliver;
1922 rth->rt_flags |= RTCF_LOCAL;
1925 #ifdef CONFIG_IP_MROUTE
1926 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1927 rth->dst.input = ip_mr_input;
1929 RT_CACHE_STAT_INC(in_slow_mc);
1931 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1932 return rt_intern_hash(hash, rth, NULL, skb, dev->ifindex);
1943 static void ip_handle_martian_source(struct net_device *dev,
1944 struct in_device *in_dev,
1945 struct sk_buff *skb,
1949 RT_CACHE_STAT_INC(in_martian_src);
1950 #ifdef CONFIG_IP_ROUTE_VERBOSE
1951 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1953 * RFC1812 recommendation, if source is martian,
1954 * the only hint is MAC header.
1956 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1957 &daddr, &saddr, dev->name);
1958 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1960 const unsigned char *p = skb_mac_header(skb);
1961 printk(KERN_WARNING "ll header: ");
1962 for (i = 0; i < dev->hard_header_len; i++, p++) {
1964 if (i < (dev->hard_header_len - 1))
1973 /* called in rcu_read_lock() section */
1974 static int __mkroute_input(struct sk_buff *skb,
1975 struct fib_result *res,
1976 struct in_device *in_dev,
1977 __be32 daddr, __be32 saddr, u32 tos,
1978 struct rtable **result)
1982 struct in_device *out_dev;
1983 unsigned int flags = 0;
1987 /* get a working reference to the output device */
1988 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1989 if (out_dev == NULL) {
1990 if (net_ratelimit())
1991 printk(KERN_CRIT "Bug in ip_route_input" \
1992 "_slow(). Please, report\n");
1997 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
1998 in_dev->dev, &spec_dst, &itag, skb->mark);
2000 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2007 flags |= RTCF_DIRECTSRC;
2009 if (out_dev == in_dev && err &&
2010 (IN_DEV_SHARED_MEDIA(out_dev) ||
2011 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2012 flags |= RTCF_DOREDIRECT;
2014 if (skb->protocol != htons(ETH_P_IP)) {
2015 /* Not IP (i.e. ARP). Do not create route, if it is
2016 * invalid for proxy arp. DNAT routes are always valid.
2018 * Proxy arp feature have been extended to allow, ARP
2019 * replies back to the same interface, to support
2020 * Private VLAN switch technologies. See arp.c.
2022 if (out_dev == in_dev &&
2023 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2030 rth = dst_alloc(&ipv4_dst_ops);
2036 atomic_set(&rth->dst.__refcnt, 1);
2037 rth->dst.flags= DST_HOST;
2038 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2039 rth->dst.flags |= DST_NOPOLICY;
2040 if (IN_DEV_CONF_GET(out_dev, NOXFRM))
2041 rth->dst.flags |= DST_NOXFRM;
2042 rth->fl.fl4_dst = daddr;
2043 rth->rt_dst = daddr;
2044 rth->fl.fl4_tos = tos;
2045 rth->fl.mark = skb->mark;
2046 rth->fl.fl4_src = saddr;
2047 rth->rt_src = saddr;
2048 rth->rt_gateway = daddr;
2050 rth->fl.iif = in_dev->dev->ifindex;
2051 rth->dst.dev = (out_dev)->dev;
2052 dev_hold(rth->dst.dev);
2053 rth->idev = in_dev_get(rth->dst.dev);
2055 rth->rt_spec_dst= spec_dst;
2057 rth->dst.obsolete = -1;
2058 rth->dst.input = ip_forward;
2059 rth->dst.output = ip_output;
2060 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2062 rt_set_nexthop(rth, res, itag);
2064 rth->rt_flags = flags;
2072 static int ip_mkroute_input(struct sk_buff *skb,
2073 struct fib_result *res,
2074 const struct flowi *fl,
2075 struct in_device *in_dev,
2076 __be32 daddr, __be32 saddr, u32 tos)
2078 struct rtable* rth = NULL;
2082 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2083 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
2084 fib_select_multipath(fl, res);
2087 /* create a routing cache entry */
2088 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2092 /* put it into the cache */
2093 hash = rt_hash(daddr, saddr, fl->iif,
2094 rt_genid(dev_net(rth->dst.dev)));
2095 return rt_intern_hash(hash, rth, NULL, skb, fl->iif);
2099 * NOTE. We drop all the packets that has local source
2100 * addresses, because every properly looped back packet
2101 * must have correct destination already attached by output routine.
2103 * Such approach solves two big problems:
2104 * 1. Not simplex devices are handled properly.
2105 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2106 * called with rcu_read_lock()
2109 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2110 u8 tos, struct net_device *dev)
2112 struct fib_result res;
2113 struct in_device *in_dev = __in_dev_get_rcu(dev);
2114 struct flowi fl = { .nl_u = { .ip4_u =
2118 .scope = RT_SCOPE_UNIVERSE,
2121 .iif = dev->ifindex };
2124 struct rtable * rth;
2128 struct net * net = dev_net(dev);
2130 /* IP on this device is disabled. */
2135 /* Check for the most weird martians, which can be not detected
2139 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2140 ipv4_is_loopback(saddr))
2141 goto martian_source;
2143 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2146 /* Accept zero addresses only to limited broadcast;
2147 * I even do not know to fix it or not. Waiting for complains :-)
2149 if (ipv4_is_zeronet(saddr))
2150 goto martian_source;
2152 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2153 goto martian_destination;
2156 * Now we are ready to route packet.
2158 err = fib_lookup(net, &fl, &res);
2160 if (!IN_DEV_FORWARD(in_dev))
2165 RT_CACHE_STAT_INC(in_slow_tot);
2167 if (res.type == RTN_BROADCAST)
2170 if (res.type == RTN_LOCAL) {
2171 err = fib_validate_source(saddr, daddr, tos,
2172 net->loopback_dev->ifindex,
2173 dev, &spec_dst, &itag, skb->mark);
2175 goto martian_source_keep_err;
2177 flags |= RTCF_DIRECTSRC;
2182 if (!IN_DEV_FORWARD(in_dev))
2184 if (res.type != RTN_UNICAST)
2185 goto martian_destination;
2187 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
2191 if (skb->protocol != htons(ETH_P_IP))
2194 if (ipv4_is_zeronet(saddr))
2195 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2197 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
2200 goto martian_source_keep_err;
2202 flags |= RTCF_DIRECTSRC;
2204 flags |= RTCF_BROADCAST;
2205 res.type = RTN_BROADCAST;
2206 RT_CACHE_STAT_INC(in_brd);
2209 rth = dst_alloc(&ipv4_dst_ops);
2213 rth->dst.output= ip_rt_bug;
2214 rth->dst.obsolete = -1;
2215 rth->rt_genid = rt_genid(net);
2217 atomic_set(&rth->dst.__refcnt, 1);
2218 rth->dst.flags= DST_HOST;
2219 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2220 rth->dst.flags |= DST_NOPOLICY;
2221 rth->fl.fl4_dst = daddr;
2222 rth->rt_dst = daddr;
2223 rth->fl.fl4_tos = tos;
2224 rth->fl.mark = skb->mark;
2225 rth->fl.fl4_src = saddr;
2226 rth->rt_src = saddr;
2227 #ifdef CONFIG_NET_CLS_ROUTE
2228 rth->dst.tclassid = itag;
2231 rth->fl.iif = dev->ifindex;
2232 rth->dst.dev = net->loopback_dev;
2233 dev_hold(rth->dst.dev);
2234 rth->idev = in_dev_get(rth->dst.dev);
2235 rth->rt_gateway = daddr;
2236 rth->rt_spec_dst= spec_dst;
2237 rth->dst.input= ip_local_deliver;
2238 rth->rt_flags = flags|RTCF_LOCAL;
2239 if (res.type == RTN_UNREACHABLE) {
2240 rth->dst.input= ip_error;
2241 rth->dst.error= -err;
2242 rth->rt_flags &= ~RTCF_LOCAL;
2244 rth->rt_type = res.type;
2245 hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
2246 err = rt_intern_hash(hash, rth, NULL, skb, fl.iif);
2250 RT_CACHE_STAT_INC(in_no_route);
2251 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2252 res.type = RTN_UNREACHABLE;
2258 * Do not cache martian addresses: they should be logged (RFC1812)
2260 martian_destination:
2261 RT_CACHE_STAT_INC(in_martian_dst);
2262 #ifdef CONFIG_IP_ROUTE_VERBOSE
2263 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2264 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2265 &daddr, &saddr, dev->name);
2269 err = -EHOSTUNREACH;
2282 martian_source_keep_err:
2283 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2287 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2288 u8 tos, struct net_device *dev, bool noref)
2290 struct rtable * rth;
2292 int iif = dev->ifindex;
2300 if (!rt_caching(net))
2303 tos &= IPTOS_RT_MASK;
2304 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2306 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2307 rth = rcu_dereference(rth->dst.rt_next)) {
2308 if ((((__force u32)rth->fl.fl4_dst ^ (__force u32)daddr) |
2309 ((__force u32)rth->fl.fl4_src ^ (__force u32)saddr) |
2310 (rth->fl.iif ^ iif) |
2312 (rth->fl.fl4_tos ^ tos)) == 0 &&
2313 rth->fl.mark == skb->mark &&
2314 net_eq(dev_net(rth->dst.dev), net) &&
2315 !rt_is_expired(rth)) {
2317 dst_use_noref(&rth->dst, jiffies);
2318 skb_dst_set_noref(skb, &rth->dst);
2320 dst_use(&rth->dst, jiffies);
2321 skb_dst_set(skb, &rth->dst);
2323 RT_CACHE_STAT_INC(in_hit);
2327 RT_CACHE_STAT_INC(in_hlist_search);
2331 /* Multicast recognition logic is moved from route cache to here.
2332 The problem was that too many Ethernet cards have broken/missing
2333 hardware multicast filters :-( As result the host on multicasting
2334 network acquires a lot of useless route cache entries, sort of
2335 SDR messages from all the world. Now we try to get rid of them.
2336 Really, provided software IP multicast filter is organized
2337 reasonably (at least, hashed), it does not result in a slowdown
2338 comparing with route cache reject entries.
2339 Note, that multicast routers are not affected, because
2340 route cache entry is created eventually.
2342 if (ipv4_is_multicast(daddr)) {
2343 struct in_device *in_dev = __in_dev_get_rcu(dev);
2346 int our = ip_check_mc(in_dev, daddr, saddr,
2347 ip_hdr(skb)->protocol);
2349 #ifdef CONFIG_IP_MROUTE
2351 (!ipv4_is_local_multicast(daddr) &&
2352 IN_DEV_MFORWARD(in_dev))
2355 int res = ip_route_input_mc(skb, daddr, saddr,
2364 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2368 EXPORT_SYMBOL(ip_route_input_common);
2370 /* called with rcu_read_lock() */
2371 static int __mkroute_output(struct rtable **result,
2372 struct fib_result *res,
2373 const struct flowi *fl,
2374 const struct flowi *oldflp,
2375 struct net_device *dev_out,
2379 struct in_device *in_dev;
2380 u32 tos = RT_FL_TOS(oldflp);
2382 if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags & IFF_LOOPBACK))
2385 if (ipv4_is_lbcast(fl->fl4_dst))
2386 res->type = RTN_BROADCAST;
2387 else if (ipv4_is_multicast(fl->fl4_dst))
2388 res->type = RTN_MULTICAST;
2389 else if (ipv4_is_zeronet(fl->fl4_dst))
2392 if (dev_out->flags & IFF_LOOPBACK)
2393 flags |= RTCF_LOCAL;
2395 in_dev = __in_dev_get_rcu(dev_out);
2399 if (res->type == RTN_BROADCAST) {
2400 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2402 } else if (res->type == RTN_MULTICAST) {
2403 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2404 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2406 flags &= ~RTCF_LOCAL;
2407 /* If multicast route do not exist use
2408 * default one, but do not gateway in this case.
2411 if (res->fi && res->prefixlen < 4)
2416 rth = dst_alloc(&ipv4_dst_ops);
2420 in_dev_hold(in_dev);
2423 atomic_set(&rth->dst.__refcnt, 1);
2424 rth->dst.flags= DST_HOST;
2425 if (IN_DEV_CONF_GET(in_dev, NOXFRM))
2426 rth->dst.flags |= DST_NOXFRM;
2427 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2428 rth->dst.flags |= DST_NOPOLICY;
2430 rth->fl.fl4_dst = oldflp->fl4_dst;
2431 rth->fl.fl4_tos = tos;
2432 rth->fl.fl4_src = oldflp->fl4_src;
2433 rth->fl.oif = oldflp->oif;
2434 rth->fl.mark = oldflp->mark;
2435 rth->rt_dst = fl->fl4_dst;
2436 rth->rt_src = fl->fl4_src;
2437 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2438 /* get references to the devices that are to be hold by the routing
2440 rth->dst.dev = dev_out;
2442 rth->rt_gateway = fl->fl4_dst;
2443 rth->rt_spec_dst= fl->fl4_src;
2445 rth->dst.output=ip_output;
2446 rth->dst.obsolete = -1;
2447 rth->rt_genid = rt_genid(dev_net(dev_out));
2449 RT_CACHE_STAT_INC(out_slow_tot);
2451 if (flags & RTCF_LOCAL) {
2452 rth->dst.input = ip_local_deliver;
2453 rth->rt_spec_dst = fl->fl4_dst;
2455 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2456 rth->rt_spec_dst = fl->fl4_src;
2457 if (flags & RTCF_LOCAL &&
2458 !(dev_out->flags & IFF_LOOPBACK)) {
2459 rth->dst.output = ip_mc_output;
2460 RT_CACHE_STAT_INC(out_slow_mc);
2462 #ifdef CONFIG_IP_MROUTE
2463 if (res->type == RTN_MULTICAST) {
2464 if (IN_DEV_MFORWARD(in_dev) &&
2465 !ipv4_is_local_multicast(oldflp->fl4_dst)) {
2466 rth->dst.input = ip_mr_input;
2467 rth->dst.output = ip_mc_output;
2473 rt_set_nexthop(rth, res, 0);
2475 rth->rt_flags = flags;
2480 /* called with rcu_read_lock() */
2481 static int ip_mkroute_output(struct rtable **rp,
2482 struct fib_result *res,
2483 const struct flowi *fl,
2484 const struct flowi *oldflp,
2485 struct net_device *dev_out,
2488 struct rtable *rth = NULL;
2489 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
2492 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
2493 rt_genid(dev_net(dev_out)));
2494 err = rt_intern_hash(hash, rth, rp, NULL, oldflp->oif);
2501 * Major route resolver routine.
2502 * called with rcu_read_lock();
2505 static int ip_route_output_slow(struct net *net, struct rtable **rp,
2506 const struct flowi *oldflp)
2508 u32 tos = RT_FL_TOS(oldflp);
2509 struct flowi fl = { .nl_u = { .ip4_u =
2510 { .daddr = oldflp->fl4_dst,
2511 .saddr = oldflp->fl4_src,
2512 .tos = tos & IPTOS_RT_MASK,
2513 .scope = ((tos & RTO_ONLINK) ?
2517 .mark = oldflp->mark,
2518 .iif = net->loopback_dev->ifindex,
2519 .oif = oldflp->oif };
2520 struct fib_result res;
2521 unsigned int flags = 0;
2522 struct net_device *dev_out = NULL;
2527 #ifdef CONFIG_IP_MULTIPLE_TABLES
2531 if (oldflp->fl4_src) {
2533 if (ipv4_is_multicast(oldflp->fl4_src) ||
2534 ipv4_is_lbcast(oldflp->fl4_src) ||
2535 ipv4_is_zeronet(oldflp->fl4_src))
2538 /* I removed check for oif == dev_out->oif here.
2539 It was wrong for two reasons:
2540 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2541 is assigned to multiple interfaces.
2542 2. Moreover, we are allowed to send packets with saddr
2543 of another iface. --ANK
2546 if (oldflp->oif == 0 &&
2547 (ipv4_is_multicast(oldflp->fl4_dst) ||
2548 ipv4_is_lbcast(oldflp->fl4_dst))) {
2549 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2550 dev_out = __ip_dev_find(net, oldflp->fl4_src, false);
2551 if (dev_out == NULL)
2554 /* Special hack: user can direct multicasts
2555 and limited broadcast via necessary interface
2556 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2557 This hack is not just for fun, it allows
2558 vic,vat and friends to work.
2559 They bind socket to loopback, set ttl to zero
2560 and expect that it will work.
2561 From the viewpoint of routing cache they are broken,
2562 because we are not allowed to build multicast path
2563 with loopback source addr (look, routing cache
2564 cannot know, that ttl is zero, so that packet
2565 will not leave this host and route is valid).
2566 Luckily, this hack is good workaround.
2569 fl.oif = dev_out->ifindex;
2573 if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
2574 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2575 if (!__ip_dev_find(net, oldflp->fl4_src, false))
2582 dev_out = dev_get_by_index_rcu(net, oldflp->oif);
2584 if (dev_out == NULL)
2587 /* RACE: Check return value of inet_select_addr instead. */
2588 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2592 if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
2593 ipv4_is_lbcast(oldflp->fl4_dst)) {
2595 fl.fl4_src = inet_select_addr(dev_out, 0,
2600 if (ipv4_is_multicast(oldflp->fl4_dst))
2601 fl.fl4_src = inet_select_addr(dev_out, 0,
2603 else if (!oldflp->fl4_dst)
2604 fl.fl4_src = inet_select_addr(dev_out, 0,
2610 fl.fl4_dst = fl.fl4_src;
2612 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2613 dev_out = net->loopback_dev;
2614 fl.oif = net->loopback_dev->ifindex;
2615 res.type = RTN_LOCAL;
2616 flags |= RTCF_LOCAL;
2620 if (fib_lookup(net, &fl, &res)) {
2623 /* Apparently, routing tables are wrong. Assume,
2624 that the destination is on link.
2627 Because we are allowed to send to iface
2628 even if it has NO routes and NO assigned
2629 addresses. When oif is specified, routing
2630 tables are looked up with only one purpose:
2631 to catch if destination is gatewayed, rather than
2632 direct. Moreover, if MSG_DONTROUTE is set,
2633 we send packet, ignoring both routing tables
2634 and ifaddr state. --ANK
2637 We could make it even if oif is unknown,
2638 likely IPv6, but we do not.
2641 if (fl.fl4_src == 0)
2642 fl.fl4_src = inet_select_addr(dev_out, 0,
2644 res.type = RTN_UNICAST;
2651 if (res.type == RTN_LOCAL) {
2653 if (res.fi->fib_prefsrc)
2654 fl.fl4_src = res.fi->fib_prefsrc;
2656 fl.fl4_src = fl.fl4_dst;
2658 dev_out = net->loopback_dev;
2659 fl.oif = dev_out->ifindex;
2661 flags |= RTCF_LOCAL;
2665 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2666 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2667 fib_select_multipath(&fl, &res);
2670 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2671 fib_select_default(net, &fl, &res);
2674 fl.fl4_src = FIB_RES_PREFSRC(res);
2676 dev_out = FIB_RES_DEV(res);
2677 fl.oif = dev_out->ifindex;
2681 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
2686 int __ip_route_output_key(struct net *net, struct rtable **rp,
2687 const struct flowi *flp)
2693 if (!rt_caching(net))
2696 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net));
2699 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2700 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2701 if (rth->fl.fl4_dst == flp->fl4_dst &&
2702 rth->fl.fl4_src == flp->fl4_src &&
2704 rth->fl.oif == flp->oif &&
2705 rth->fl.mark == flp->mark &&
2706 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2707 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2708 net_eq(dev_net(rth->dst.dev), net) &&
2709 !rt_is_expired(rth)) {
2710 dst_use(&rth->dst, jiffies);
2711 RT_CACHE_STAT_INC(out_hit);
2712 rcu_read_unlock_bh();
2716 RT_CACHE_STAT_INC(out_hlist_search);
2718 rcu_read_unlock_bh();
2722 res = ip_route_output_slow(net, rp, flp);
2726 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2728 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2733 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2737 static struct dst_ops ipv4_dst_blackhole_ops = {
2739 .protocol = cpu_to_be16(ETH_P_IP),
2740 .destroy = ipv4_dst_destroy,
2741 .check = ipv4_blackhole_dst_check,
2742 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2746 static int ipv4_dst_blackhole(struct net *net, struct rtable **rp, struct flowi *flp)
2748 struct rtable *ort = *rp;
2749 struct rtable *rt = (struct rtable *)
2750 dst_alloc(&ipv4_dst_blackhole_ops);
2753 struct dst_entry *new = &rt->dst;
2755 atomic_set(&new->__refcnt, 1);
2757 new->input = dst_discard;
2758 new->output = dst_discard;
2759 memcpy(new->metrics, ort->dst.metrics, RTAX_MAX*sizeof(u32));
2761 new->dev = ort->dst.dev;
2767 rt->idev = ort->idev;
2769 in_dev_hold(rt->idev);
2770 rt->rt_genid = rt_genid(net);
2771 rt->rt_flags = ort->rt_flags;
2772 rt->rt_type = ort->rt_type;
2773 rt->rt_dst = ort->rt_dst;
2774 rt->rt_src = ort->rt_src;
2775 rt->rt_iif = ort->rt_iif;
2776 rt->rt_gateway = ort->rt_gateway;
2777 rt->rt_spec_dst = ort->rt_spec_dst;
2778 rt->peer = ort->peer;
2780 atomic_inc(&rt->peer->refcnt);
2785 dst_release(&(*rp)->dst);
2787 return rt ? 0 : -ENOMEM;
2790 int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
2791 struct sock *sk, int flags)
2795 if ((err = __ip_route_output_key(net, rp, flp)) != 0)
2800 flp->fl4_src = (*rp)->rt_src;
2802 flp->fl4_dst = (*rp)->rt_dst;
2803 err = __xfrm_lookup(net, (struct dst_entry **)rp, flp, sk,
2804 flags ? XFRM_LOOKUP_WAIT : 0);
2805 if (err == -EREMOTE)
2806 err = ipv4_dst_blackhole(net, rp, flp);
2813 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2815 int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp)
2817 return ip_route_output_flow(net, rp, flp, NULL, 0);
2819 EXPORT_SYMBOL(ip_route_output_key);
2821 static int rt_fill_info(struct net *net,
2822 struct sk_buff *skb, u32 pid, u32 seq, int event,
2823 int nowait, unsigned int flags)
2825 struct rtable *rt = skb_rtable(skb);
2827 struct nlmsghdr *nlh;
2829 u32 id = 0, ts = 0, tsage = 0, error;
2831 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2835 r = nlmsg_data(nlh);
2836 r->rtm_family = AF_INET;
2837 r->rtm_dst_len = 32;
2839 r->rtm_tos = rt->fl.fl4_tos;
2840 r->rtm_table = RT_TABLE_MAIN;
2841 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2842 r->rtm_type = rt->rt_type;
2843 r->rtm_scope = RT_SCOPE_UNIVERSE;
2844 r->rtm_protocol = RTPROT_UNSPEC;
2845 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2846 if (rt->rt_flags & RTCF_NOTIFY)
2847 r->rtm_flags |= RTM_F_NOTIFY;
2849 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2851 if (rt->fl.fl4_src) {
2852 r->rtm_src_len = 32;
2853 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
2856 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2857 #ifdef CONFIG_NET_CLS_ROUTE
2858 if (rt->dst.tclassid)
2859 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2862 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2863 else if (rt->rt_src != rt->fl.fl4_src)
2864 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2866 if (rt->rt_dst != rt->rt_gateway)
2867 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2869 if (rtnetlink_put_metrics(skb, rt->dst.metrics) < 0)
2870 goto nla_put_failure;
2873 NLA_PUT_BE32(skb, RTA_MARK, rt->fl.mark);
2875 error = rt->dst.error;
2876 expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
2878 inet_peer_refcheck(rt->peer);
2879 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2880 if (rt->peer->tcp_ts_stamp) {
2881 ts = rt->peer->tcp_ts;
2882 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2887 #ifdef CONFIG_IP_MROUTE
2888 __be32 dst = rt->rt_dst;
2890 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2891 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2892 int err = ipmr_get_route(net, skb, r, nowait);
2897 goto nla_put_failure;
2899 if (err == -EMSGSIZE)
2900 goto nla_put_failure;
2906 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
2909 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2910 expires, error) < 0)
2911 goto nla_put_failure;
2913 return nlmsg_end(skb, nlh);
2916 nlmsg_cancel(skb, nlh);
2920 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2922 struct net *net = sock_net(in_skb->sk);
2924 struct nlattr *tb[RTA_MAX+1];
2925 struct rtable *rt = NULL;
2931 struct sk_buff *skb;
2933 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2937 rtm = nlmsg_data(nlh);
2939 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2945 /* Reserve room for dummy headers, this skb can pass
2946 through good chunk of routing engine.
2948 skb_reset_mac_header(skb);
2949 skb_reset_network_header(skb);
2951 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2952 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2953 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2955 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2956 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2957 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2958 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2961 struct net_device *dev;
2963 dev = __dev_get_by_index(net, iif);
2969 skb->protocol = htons(ETH_P_IP);
2973 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2976 rt = skb_rtable(skb);
2977 if (err == 0 && rt->dst.error)
2978 err = -rt->dst.error;
2985 .tos = rtm->rtm_tos,
2988 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2991 err = ip_route_output_key(net, &rt, &fl);
2997 skb_dst_set(skb, &rt->dst);
2998 if (rtm->rtm_flags & RTM_F_NOTIFY)
2999 rt->rt_flags |= RTCF_NOTIFY;
3001 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3002 RTM_NEWROUTE, 0, 0);
3006 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3015 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3022 net = sock_net(skb->sk);
3027 s_idx = idx = cb->args[1];
3028 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3029 if (!rt_hash_table[h].chain)
3032 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3033 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3034 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3036 if (rt_is_expired(rt))
3038 skb_dst_set_noref(skb, &rt->dst);
3039 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3040 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3041 1, NLM_F_MULTI) <= 0) {
3043 rcu_read_unlock_bh();
3048 rcu_read_unlock_bh();
3057 void ip_rt_multicast_event(struct in_device *in_dev)
3059 rt_cache_flush(dev_net(in_dev->dev), 0);
3062 #ifdef CONFIG_SYSCTL
3063 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3064 void __user *buffer,
3065 size_t *lenp, loff_t *ppos)
3072 memcpy(&ctl, __ctl, sizeof(ctl));
3073 ctl.data = &flush_delay;
3074 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3076 net = (struct net *)__ctl->extra1;
3077 rt_cache_flush(net, flush_delay);
3084 static ctl_table ipv4_route_table[] = {
3086 .procname = "gc_thresh",
3087 .data = &ipv4_dst_ops.gc_thresh,
3088 .maxlen = sizeof(int),
3090 .proc_handler = proc_dointvec,
3093 .procname = "max_size",
3094 .data = &ip_rt_max_size,
3095 .maxlen = sizeof(int),
3097 .proc_handler = proc_dointvec,
3100 /* Deprecated. Use gc_min_interval_ms */
3102 .procname = "gc_min_interval",
3103 .data = &ip_rt_gc_min_interval,
3104 .maxlen = sizeof(int),
3106 .proc_handler = proc_dointvec_jiffies,
3109 .procname = "gc_min_interval_ms",
3110 .data = &ip_rt_gc_min_interval,
3111 .maxlen = sizeof(int),
3113 .proc_handler = proc_dointvec_ms_jiffies,
3116 .procname = "gc_timeout",
3117 .data = &ip_rt_gc_timeout,
3118 .maxlen = sizeof(int),
3120 .proc_handler = proc_dointvec_jiffies,
3123 .procname = "gc_interval",
3124 .data = &ip_rt_gc_interval,
3125 .maxlen = sizeof(int),
3127 .proc_handler = proc_dointvec_jiffies,
3130 .procname = "redirect_load",
3131 .data = &ip_rt_redirect_load,
3132 .maxlen = sizeof(int),
3134 .proc_handler = proc_dointvec,
3137 .procname = "redirect_number",
3138 .data = &ip_rt_redirect_number,
3139 .maxlen = sizeof(int),
3141 .proc_handler = proc_dointvec,
3144 .procname = "redirect_silence",
3145 .data = &ip_rt_redirect_silence,
3146 .maxlen = sizeof(int),
3148 .proc_handler = proc_dointvec,
3151 .procname = "error_cost",
3152 .data = &ip_rt_error_cost,
3153 .maxlen = sizeof(int),
3155 .proc_handler = proc_dointvec,
3158 .procname = "error_burst",
3159 .data = &ip_rt_error_burst,
3160 .maxlen = sizeof(int),
3162 .proc_handler = proc_dointvec,
3165 .procname = "gc_elasticity",
3166 .data = &ip_rt_gc_elasticity,
3167 .maxlen = sizeof(int),
3169 .proc_handler = proc_dointvec,
3172 .procname = "mtu_expires",
3173 .data = &ip_rt_mtu_expires,
3174 .maxlen = sizeof(int),
3176 .proc_handler = proc_dointvec_jiffies,
3179 .procname = "min_pmtu",
3180 .data = &ip_rt_min_pmtu,
3181 .maxlen = sizeof(int),
3183 .proc_handler = proc_dointvec,
3186 .procname = "min_adv_mss",
3187 .data = &ip_rt_min_advmss,
3188 .maxlen = sizeof(int),
3190 .proc_handler = proc_dointvec,
3195 static struct ctl_table empty[1];
3197 static struct ctl_table ipv4_skeleton[] =
3199 { .procname = "route",
3200 .mode = 0555, .child = ipv4_route_table},
3201 { .procname = "neigh",
3202 .mode = 0555, .child = empty},
3206 static __net_initdata struct ctl_path ipv4_path[] = {
3207 { .procname = "net", },
3208 { .procname = "ipv4", },
3212 static struct ctl_table ipv4_route_flush_table[] = {
3214 .procname = "flush",
3215 .maxlen = sizeof(int),
3217 .proc_handler = ipv4_sysctl_rtcache_flush,
3222 static __net_initdata struct ctl_path ipv4_route_path[] = {
3223 { .procname = "net", },
3224 { .procname = "ipv4", },
3225 { .procname = "route", },
3229 static __net_init int sysctl_route_net_init(struct net *net)
3231 struct ctl_table *tbl;
3233 tbl = ipv4_route_flush_table;
3234 if (!net_eq(net, &init_net)) {
3235 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3239 tbl[0].extra1 = net;
3241 net->ipv4.route_hdr =
3242 register_net_sysctl_table(net, ipv4_route_path, tbl);
3243 if (net->ipv4.route_hdr == NULL)
3248 if (tbl != ipv4_route_flush_table)
3254 static __net_exit void sysctl_route_net_exit(struct net *net)
3256 struct ctl_table *tbl;
3258 tbl = net->ipv4.route_hdr->ctl_table_arg;
3259 unregister_net_sysctl_table(net->ipv4.route_hdr);
3260 BUG_ON(tbl == ipv4_route_flush_table);
3264 static __net_initdata struct pernet_operations sysctl_route_ops = {
3265 .init = sysctl_route_net_init,
3266 .exit = sysctl_route_net_exit,
3270 static __net_init int rt_genid_init(struct net *net)
3272 get_random_bytes(&net->ipv4.rt_genid,
3273 sizeof(net->ipv4.rt_genid));
3277 static __net_initdata struct pernet_operations rt_genid_ops = {
3278 .init = rt_genid_init,
3282 #ifdef CONFIG_NET_CLS_ROUTE
3283 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3284 #endif /* CONFIG_NET_CLS_ROUTE */
3286 static __initdata unsigned long rhash_entries;
3287 static int __init set_rhash_entries(char *str)
3291 rhash_entries = simple_strtoul(str, &str, 0);
3294 __setup("rhash_entries=", set_rhash_entries);
3296 int __init ip_rt_init(void)
3300 #ifdef CONFIG_NET_CLS_ROUTE
3301 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3303 panic("IP: failed to allocate ip_rt_acct\n");
3306 ipv4_dst_ops.kmem_cachep =
3307 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3308 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3310 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3312 if (dst_entries_init(&ipv4_dst_ops) < 0)
3313 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3315 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3316 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3318 rt_hash_table = (struct rt_hash_bucket *)
3319 alloc_large_system_hash("IP route cache",
3320 sizeof(struct rt_hash_bucket),
3322 (totalram_pages >= 128 * 1024) ?
3327 rhash_entries ? 0 : 512 * 1024);
3328 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3329 rt_hash_lock_init();
3331 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3332 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3337 /* All the timers, started at system startup tend
3338 to synchronize. Perturb it a bit.
3340 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func);
3341 expires_ljiffies = jiffies;
3342 schedule_delayed_work(&expires_work,
3343 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3345 if (ip_rt_proc_init())
3346 printk(KERN_ERR "Unable to create route proc files\n");
3349 xfrm4_init(ip_rt_max_size);
3351 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3353 #ifdef CONFIG_SYSCTL
3354 register_pernet_subsys(&sysctl_route_ops);
3356 register_pernet_subsys(&rt_genid_ops);
3360 #ifdef CONFIG_SYSCTL
3362 * We really need to sanitize the damn ipv4 init order, then all
3363 * this nonsense will go away.
3365 void __init ip_static_sysctl_init(void)
3367 register_sysctl_paths(ipv4_path, ipv4_skeleton);