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>
94 #include <net/net_namespace.h>
95 #include <net/protocol.h>
97 #include <net/route.h>
98 #include <net/inetpeer.h>
100 #include <net/ip_fib.h>
103 #include <net/icmp.h>
104 #include <net/xfrm.h>
105 #include <net/netevent.h>
106 #include <net/rtnetlink.h>
108 #include <linux/sysctl.h>
111 #define RT_FL_TOS(oldflp) \
112 ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
114 #define IP_MAX_MTU 0xFFF0
116 #define RT_GC_TIMEOUT (300*HZ)
118 static int ip_rt_max_size;
119 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
120 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
121 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
122 static int ip_rt_redirect_number __read_mostly = 9;
123 static int ip_rt_redirect_load __read_mostly = HZ / 50;
124 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
125 static int ip_rt_error_cost __read_mostly = HZ;
126 static int ip_rt_error_burst __read_mostly = 5 * HZ;
127 static int ip_rt_gc_elasticity __read_mostly = 8;
128 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
129 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
130 static int ip_rt_min_advmss __read_mostly = 256;
131 static int ip_rt_secret_interval __read_mostly = 10 * 60 * HZ;
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,
162 .entries = ATOMIC_INIT(0),
165 #define ECN_OR_COST(class) TC_PRIO_##class
167 const __u8 ip_tos2prio[16] = {
171 ECN_OR_COST(BESTEFFORT),
177 ECN_OR_COST(INTERACTIVE),
179 ECN_OR_COST(INTERACTIVE),
180 TC_PRIO_INTERACTIVE_BULK,
181 ECN_OR_COST(INTERACTIVE_BULK),
182 TC_PRIO_INTERACTIVE_BULK,
183 ECN_OR_COST(INTERACTIVE_BULK)
191 /* The locking scheme is rather straight forward:
193 * 1) Read-Copy Update protects the buckets of the central route hash.
194 * 2) Only writers remove entries, and they hold the lock
195 * as they look at rtable reference counts.
196 * 3) Only readers acquire references to rtable entries,
197 * they do so with atomic increments and with the
201 struct rt_hash_bucket {
202 struct rtable *chain;
205 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
206 defined(CONFIG_PROVE_LOCKING)
208 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
209 * The size of this table is a power of two and depends on the number of CPUS.
210 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
212 #ifdef CONFIG_LOCKDEP
213 # define RT_HASH_LOCK_SZ 256
216 # define RT_HASH_LOCK_SZ 4096
218 # define RT_HASH_LOCK_SZ 2048
220 # define RT_HASH_LOCK_SZ 1024
222 # define RT_HASH_LOCK_SZ 512
224 # define RT_HASH_LOCK_SZ 256
228 static spinlock_t *rt_hash_locks;
229 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
231 static __init void rt_hash_lock_init(void)
235 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
238 panic("IP: failed to allocate rt_hash_locks\n");
240 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
241 spin_lock_init(&rt_hash_locks[i]);
244 # define rt_hash_lock_addr(slot) NULL
246 static inline void rt_hash_lock_init(void)
251 static struct rt_hash_bucket *rt_hash_table __read_mostly;
252 static unsigned rt_hash_mask __read_mostly;
253 static unsigned int rt_hash_log __read_mostly;
255 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
256 #define RT_CACHE_STAT_INC(field) \
257 (__raw_get_cpu_var(rt_cache_stat).field++)
259 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
262 return jhash_3words((__force u32)(__be32)(daddr),
263 (__force u32)(__be32)(saddr),
268 static inline int rt_genid(struct net *net)
270 return atomic_read(&net->ipv4.rt_genid);
273 #ifdef CONFIG_PROC_FS
274 struct rt_cache_iter_state {
275 struct seq_net_private p;
280 static struct rtable *rt_cache_get_first(struct seq_file *seq)
282 struct rt_cache_iter_state *st = seq->private;
283 struct rtable *r = NULL;
285 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
286 if (!rt_hash_table[st->bucket].chain)
289 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
291 if (dev_net(r->u.dst.dev) == seq_file_net(seq) &&
292 r->rt_genid == st->genid)
294 r = rcu_dereference_bh(r->u.dst.rt_next);
296 rcu_read_unlock_bh();
301 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
304 struct rt_cache_iter_state *st = seq->private;
306 r = r->u.dst.rt_next;
308 rcu_read_unlock_bh();
310 if (--st->bucket < 0)
312 } while (!rt_hash_table[st->bucket].chain);
314 r = rt_hash_table[st->bucket].chain;
316 return rcu_dereference_bh(r);
319 static struct rtable *rt_cache_get_next(struct seq_file *seq,
322 struct rt_cache_iter_state *st = seq->private;
323 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
324 if (dev_net(r->u.dst.dev) != seq_file_net(seq))
326 if (r->rt_genid == st->genid)
332 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
334 struct rtable *r = rt_cache_get_first(seq);
337 while (pos && (r = rt_cache_get_next(seq, r)))
339 return pos ? NULL : r;
342 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
344 struct rt_cache_iter_state *st = seq->private;
346 return rt_cache_get_idx(seq, *pos - 1);
347 st->genid = rt_genid(seq_file_net(seq));
348 return SEQ_START_TOKEN;
351 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
355 if (v == SEQ_START_TOKEN)
356 r = rt_cache_get_first(seq);
358 r = rt_cache_get_next(seq, v);
363 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
365 if (v && v != SEQ_START_TOKEN)
366 rcu_read_unlock_bh();
369 static int rt_cache_seq_show(struct seq_file *seq, void *v)
371 if (v == SEQ_START_TOKEN)
372 seq_printf(seq, "%-127s\n",
373 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
374 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
377 struct rtable *r = v;
380 seq_printf(seq, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
381 "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
382 r->u.dst.dev ? r->u.dst.dev->name : "*",
383 (unsigned long)r->rt_dst, (unsigned long)r->rt_gateway,
384 r->rt_flags, atomic_read(&r->u.dst.__refcnt),
385 r->u.dst.__use, 0, (unsigned long)r->rt_src,
386 (dst_metric(&r->u.dst, RTAX_ADVMSS) ?
387 (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0),
388 dst_metric(&r->u.dst, RTAX_WINDOW),
389 (int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) +
390 dst_metric(&r->u.dst, RTAX_RTTVAR)),
392 r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1,
393 r->u.dst.hh ? (r->u.dst.hh->hh_output ==
395 r->rt_spec_dst, &len);
397 seq_printf(seq, "%*s\n", 127 - len, "");
402 static const struct seq_operations rt_cache_seq_ops = {
403 .start = rt_cache_seq_start,
404 .next = rt_cache_seq_next,
405 .stop = rt_cache_seq_stop,
406 .show = rt_cache_seq_show,
409 static int rt_cache_seq_open(struct inode *inode, struct file *file)
411 return seq_open_net(inode, file, &rt_cache_seq_ops,
412 sizeof(struct rt_cache_iter_state));
415 static const struct file_operations rt_cache_seq_fops = {
416 .owner = THIS_MODULE,
417 .open = rt_cache_seq_open,
420 .release = seq_release_net,
424 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
429 return SEQ_START_TOKEN;
431 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
432 if (!cpu_possible(cpu))
435 return &per_cpu(rt_cache_stat, cpu);
440 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
444 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
445 if (!cpu_possible(cpu))
448 return &per_cpu(rt_cache_stat, cpu);
454 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
459 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
461 struct rt_cache_stat *st = v;
463 if (v == SEQ_START_TOKEN) {
464 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");
468 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
469 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
470 atomic_read(&ipv4_dst_ops.entries),
493 static const struct seq_operations rt_cpu_seq_ops = {
494 .start = rt_cpu_seq_start,
495 .next = rt_cpu_seq_next,
496 .stop = rt_cpu_seq_stop,
497 .show = rt_cpu_seq_show,
501 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
503 return seq_open(file, &rt_cpu_seq_ops);
506 static const struct file_operations rt_cpu_seq_fops = {
507 .owner = THIS_MODULE,
508 .open = rt_cpu_seq_open,
511 .release = seq_release,
514 #ifdef CONFIG_NET_CLS_ROUTE
515 static int rt_acct_proc_show(struct seq_file *m, void *v)
517 struct ip_rt_acct *dst, *src;
520 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
524 for_each_possible_cpu(i) {
525 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
526 for (j = 0; j < 256; j++) {
527 dst[j].o_bytes += src[j].o_bytes;
528 dst[j].o_packets += src[j].o_packets;
529 dst[j].i_bytes += src[j].i_bytes;
530 dst[j].i_packets += src[j].i_packets;
534 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
539 static int rt_acct_proc_open(struct inode *inode, struct file *file)
541 return single_open(file, rt_acct_proc_show, NULL);
544 static const struct file_operations rt_acct_proc_fops = {
545 .owner = THIS_MODULE,
546 .open = rt_acct_proc_open,
549 .release = single_release,
553 static int __net_init ip_rt_do_proc_init(struct net *net)
555 struct proc_dir_entry *pde;
557 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
562 pde = proc_create("rt_cache", S_IRUGO,
563 net->proc_net_stat, &rt_cpu_seq_fops);
567 #ifdef CONFIG_NET_CLS_ROUTE
568 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
574 #ifdef CONFIG_NET_CLS_ROUTE
576 remove_proc_entry("rt_cache", net->proc_net_stat);
579 remove_proc_entry("rt_cache", net->proc_net);
584 static void __net_exit ip_rt_do_proc_exit(struct net *net)
586 remove_proc_entry("rt_cache", net->proc_net_stat);
587 remove_proc_entry("rt_cache", net->proc_net);
588 #ifdef CONFIG_NET_CLS_ROUTE
589 remove_proc_entry("rt_acct", net->proc_net);
593 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
594 .init = ip_rt_do_proc_init,
595 .exit = ip_rt_do_proc_exit,
598 static int __init ip_rt_proc_init(void)
600 return register_pernet_subsys(&ip_rt_proc_ops);
604 static inline int ip_rt_proc_init(void)
608 #endif /* CONFIG_PROC_FS */
610 static inline void rt_free(struct rtable *rt)
612 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
615 static inline void rt_drop(struct rtable *rt)
618 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
621 static inline int rt_fast_clean(struct rtable *rth)
623 /* Kill broadcast/multicast entries very aggresively, if they
624 collide in hash table with more useful entries */
625 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
626 rth->fl.iif && rth->u.dst.rt_next;
629 static inline int rt_valuable(struct rtable *rth)
631 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
635 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
640 if (atomic_read(&rth->u.dst.__refcnt))
644 if (rth->u.dst.expires &&
645 time_after_eq(jiffies, rth->u.dst.expires))
648 age = jiffies - rth->u.dst.lastuse;
650 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
651 (age <= tmo2 && rt_valuable(rth)))
657 /* Bits of score are:
659 * 30: not quite useless
660 * 29..0: usage counter
662 static inline u32 rt_score(struct rtable *rt)
664 u32 score = jiffies - rt->u.dst.lastuse;
666 score = ~score & ~(3<<30);
672 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
678 static inline bool rt_caching(const struct net *net)
680 return net->ipv4.current_rt_cache_rebuild_count <=
681 net->ipv4.sysctl_rt_cache_rebuild_count;
684 static inline bool compare_hash_inputs(const struct flowi *fl1,
685 const struct flowi *fl2)
687 return (__force u32)(((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
688 (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr) |
689 (fl1->iif ^ fl2->iif)) == 0);
692 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
694 return ((__force u32)((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
695 (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr)) |
696 (fl1->mark ^ fl2->mark) |
697 (*(u16 *)&fl1->nl_u.ip4_u.tos ^
698 *(u16 *)&fl2->nl_u.ip4_u.tos) |
699 (fl1->oif ^ fl2->oif) |
700 (fl1->iif ^ fl2->iif)) == 0;
703 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
705 return net_eq(dev_net(rt1->u.dst.dev), dev_net(rt2->u.dst.dev));
708 static inline int rt_is_expired(struct rtable *rth)
710 return rth->rt_genid != rt_genid(dev_net(rth->u.dst.dev));
714 * Perform a full scan of hash table and free all entries.
715 * Can be called by a softirq or a process.
716 * In the later case, we want to be reschedule if necessary
718 static void rt_do_flush(int process_context)
721 struct rtable *rth, *next;
722 struct rtable * tail;
724 for (i = 0; i <= rt_hash_mask; i++) {
725 if (process_context && need_resched())
727 rth = rt_hash_table[i].chain;
731 spin_lock_bh(rt_hash_lock_addr(i));
734 struct rtable ** prev, * p;
736 rth = rt_hash_table[i].chain;
738 /* defer releasing the head of the list after spin_unlock */
739 for (tail = rth; tail; tail = tail->u.dst.rt_next)
740 if (!rt_is_expired(tail))
743 rt_hash_table[i].chain = tail;
745 /* call rt_free on entries after the tail requiring flush */
746 prev = &rt_hash_table[i].chain;
747 for (p = *prev; p; p = next) {
748 next = p->u.dst.rt_next;
749 if (!rt_is_expired(p)) {
750 prev = &p->u.dst.rt_next;
758 rth = rt_hash_table[i].chain;
759 rt_hash_table[i].chain = NULL;
762 spin_unlock_bh(rt_hash_lock_addr(i));
764 for (; rth != tail; rth = next) {
765 next = rth->u.dst.rt_next;
772 * While freeing expired entries, we compute average chain length
773 * and standard deviation, using fixed-point arithmetic.
774 * This to have an estimation of rt_chain_length_max
775 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
776 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
780 #define ONE (1UL << FRACT_BITS)
783 * Given a hash chain and an item in this hash chain,
784 * find if a previous entry has the same hash_inputs
785 * (but differs on tos, mark or oif)
786 * Returns 0 if an alias is found.
787 * Returns ONE if rth has no alias before itself.
789 static int has_noalias(const struct rtable *head, const struct rtable *rth)
791 const struct rtable *aux = head;
794 if (compare_hash_inputs(&aux->fl, &rth->fl))
796 aux = aux->u.dst.rt_next;
801 static void rt_check_expire(void)
803 static unsigned int rover;
804 unsigned int i = rover, goal;
805 struct rtable *rth, **rthp;
806 unsigned long samples = 0;
807 unsigned long sum = 0, sum2 = 0;
811 delta = jiffies - expires_ljiffies;
812 expires_ljiffies = jiffies;
813 mult = ((u64)delta) << rt_hash_log;
814 if (ip_rt_gc_timeout > 1)
815 do_div(mult, ip_rt_gc_timeout);
816 goal = (unsigned int)mult;
817 if (goal > rt_hash_mask)
818 goal = rt_hash_mask + 1;
819 for (; goal > 0; goal--) {
820 unsigned long tmo = ip_rt_gc_timeout;
821 unsigned long length;
823 i = (i + 1) & rt_hash_mask;
824 rthp = &rt_hash_table[i].chain;
834 spin_lock_bh(rt_hash_lock_addr(i));
835 while ((rth = *rthp) != NULL) {
836 prefetch(rth->u.dst.rt_next);
837 if (rt_is_expired(rth)) {
838 *rthp = rth->u.dst.rt_next;
842 if (rth->u.dst.expires) {
843 /* Entry is expired even if it is in use */
844 if (time_before_eq(jiffies, rth->u.dst.expires)) {
847 rthp = &rth->u.dst.rt_next;
849 * We only count entries on
850 * a chain with equal hash inputs once
851 * so that entries for different QOS
852 * levels, and other non-hash input
853 * attributes don't unfairly skew
854 * the length computation
856 length += has_noalias(rt_hash_table[i].chain, rth);
859 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout))
862 /* Cleanup aged off entries. */
863 *rthp = rth->u.dst.rt_next;
866 spin_unlock_bh(rt_hash_lock_addr(i));
868 sum2 += length*length;
871 unsigned long avg = sum / samples;
872 unsigned long sd = int_sqrt(sum2 / samples - avg*avg);
873 rt_chain_length_max = max_t(unsigned long,
875 (avg + 4*sd) >> FRACT_BITS);
881 * rt_worker_func() is run in process context.
882 * we call rt_check_expire() to scan part of the hash table
884 static void rt_worker_func(struct work_struct *work)
887 schedule_delayed_work(&expires_work, ip_rt_gc_interval);
891 * Pertubation of rt_genid by a small quantity [1..256]
892 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
893 * many times (2^24) without giving recent rt_genid.
894 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
896 static void rt_cache_invalidate(struct net *net)
898 unsigned char shuffle;
900 get_random_bytes(&shuffle, sizeof(shuffle));
901 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
905 * delay < 0 : invalidate cache (fast : entries will be deleted later)
906 * delay >= 0 : invalidate & flush cache (can be long)
908 void rt_cache_flush(struct net *net, int delay)
910 rt_cache_invalidate(net);
912 rt_do_flush(!in_softirq());
915 /* Flush previous cache invalidated entries from the cache */
916 void rt_cache_flush_batch(void)
918 rt_do_flush(!in_softirq());
922 * We change rt_genid and let gc do the cleanup
924 static void rt_secret_rebuild(unsigned long __net)
926 struct net *net = (struct net *)__net;
927 rt_cache_invalidate(net);
928 mod_timer(&net->ipv4.rt_secret_timer, jiffies + ip_rt_secret_interval);
931 static void rt_secret_rebuild_oneshot(struct net *net)
933 del_timer_sync(&net->ipv4.rt_secret_timer);
934 rt_cache_invalidate(net);
935 if (ip_rt_secret_interval)
936 mod_timer(&net->ipv4.rt_secret_timer, jiffies + ip_rt_secret_interval);
939 static void rt_emergency_hash_rebuild(struct net *net)
941 if (net_ratelimit()) {
942 printk(KERN_WARNING "Route hash chain too long!\n");
943 printk(KERN_WARNING "Adjust your secret_interval!\n");
946 rt_secret_rebuild_oneshot(net);
950 Short description of GC goals.
952 We want to build algorithm, which will keep routing cache
953 at some equilibrium point, when number of aged off entries
954 is kept approximately equal to newly generated ones.
956 Current expiration strength is variable "expire".
957 We try to adjust it dynamically, so that if networking
958 is idle expires is large enough to keep enough of warm entries,
959 and when load increases it reduces to limit cache size.
962 static int rt_garbage_collect(struct dst_ops *ops)
964 static unsigned long expire = RT_GC_TIMEOUT;
965 static unsigned long last_gc;
967 static int equilibrium;
968 struct rtable *rth, **rthp;
969 unsigned long now = jiffies;
973 * Garbage collection is pretty expensive,
974 * do not make it too frequently.
977 RT_CACHE_STAT_INC(gc_total);
979 if (now - last_gc < ip_rt_gc_min_interval &&
980 atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
981 RT_CACHE_STAT_INC(gc_ignored);
985 /* Calculate number of entries, which we want to expire now. */
986 goal = atomic_read(&ipv4_dst_ops.entries) -
987 (ip_rt_gc_elasticity << rt_hash_log);
989 if (equilibrium < ipv4_dst_ops.gc_thresh)
990 equilibrium = ipv4_dst_ops.gc_thresh;
991 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
993 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
994 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
997 /* We are in dangerous area. Try to reduce cache really
1000 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
1001 equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
1004 if (now - last_gc >= ip_rt_gc_min_interval)
1008 equilibrium += goal;
1015 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
1016 unsigned long tmo = expire;
1018 k = (k + 1) & rt_hash_mask;
1019 rthp = &rt_hash_table[k].chain;
1020 spin_lock_bh(rt_hash_lock_addr(k));
1021 while ((rth = *rthp) != NULL) {
1022 if (!rt_is_expired(rth) &&
1023 !rt_may_expire(rth, tmo, expire)) {
1025 rthp = &rth->u.dst.rt_next;
1028 *rthp = rth->u.dst.rt_next;
1032 spin_unlock_bh(rt_hash_lock_addr(k));
1041 /* Goal is not achieved. We stop process if:
1043 - if expire reduced to zero. Otherwise, expire is halfed.
1044 - if table is not full.
1045 - if we are called from interrupt.
1046 - jiffies check is just fallback/debug loop breaker.
1047 We will not spin here for long time in any case.
1050 RT_CACHE_STAT_INC(gc_goal_miss);
1056 #if RT_CACHE_DEBUG >= 2
1057 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
1058 atomic_read(&ipv4_dst_ops.entries), goal, i);
1061 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
1063 } while (!in_softirq() && time_before_eq(jiffies, now));
1065 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
1067 if (net_ratelimit())
1068 printk(KERN_WARNING "dst cache overflow\n");
1069 RT_CACHE_STAT_INC(gc_dst_overflow);
1073 expire += ip_rt_gc_min_interval;
1074 if (expire > ip_rt_gc_timeout ||
1075 atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
1076 expire = ip_rt_gc_timeout;
1077 #if RT_CACHE_DEBUG >= 2
1078 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
1079 atomic_read(&ipv4_dst_ops.entries), goal, rover);
1085 * Returns number of entries in a hash chain that have different hash_inputs
1087 static int slow_chain_length(const struct rtable *head)
1090 const struct rtable *rth = head;
1093 length += has_noalias(head, rth);
1094 rth = rth->u.dst.rt_next;
1096 return length >> FRACT_BITS;
1099 static int rt_intern_hash(unsigned hash, struct rtable *rt,
1100 struct rtable **rp, struct sk_buff *skb)
1102 struct rtable *rth, **rthp;
1104 struct rtable *cand, **candp;
1107 int attempts = !in_softirq();
1111 min_score = ~(u32)0;
1116 if (!rt_caching(dev_net(rt->u.dst.dev))) {
1118 * If we're not caching, just tell the caller we
1119 * were successful and don't touch the route. The
1120 * caller hold the sole reference to the cache entry, and
1121 * it will be released when the caller is done with it.
1122 * If we drop it here, the callers have no way to resolve routes
1123 * when we're not caching. Instead, just point *rp at rt, so
1124 * the caller gets a single use out of the route
1125 * Note that we do rt_free on this new route entry, so that
1126 * once its refcount hits zero, we are still able to reap it
1128 * Note also the rt_free uses call_rcu. We don't actually
1129 * need rcu protection here, this is just our path to get
1130 * on the route gc list.
1133 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1134 int err = arp_bind_neighbour(&rt->u.dst);
1136 if (net_ratelimit())
1138 "Neighbour table failure & not caching routes.\n");
1148 rthp = &rt_hash_table[hash].chain;
1150 spin_lock_bh(rt_hash_lock_addr(hash));
1151 while ((rth = *rthp) != NULL) {
1152 if (rt_is_expired(rth)) {
1153 *rthp = rth->u.dst.rt_next;
1157 if (compare_keys(&rth->fl, &rt->fl) && compare_netns(rth, rt)) {
1159 *rthp = rth->u.dst.rt_next;
1161 * Since lookup is lockfree, the deletion
1162 * must be visible to another weakly ordered CPU before
1163 * the insertion at the start of the hash chain.
1165 rcu_assign_pointer(rth->u.dst.rt_next,
1166 rt_hash_table[hash].chain);
1168 * Since lookup is lockfree, the update writes
1169 * must be ordered for consistency on SMP.
1171 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1173 dst_use(&rth->u.dst, now);
1174 spin_unlock_bh(rt_hash_lock_addr(hash));
1180 skb_dst_set(skb, &rth->u.dst);
1184 if (!atomic_read(&rth->u.dst.__refcnt)) {
1185 u32 score = rt_score(rth);
1187 if (score <= min_score) {
1196 rthp = &rth->u.dst.rt_next;
1200 /* ip_rt_gc_elasticity used to be average length of chain
1201 * length, when exceeded gc becomes really aggressive.
1203 * The second limit is less certain. At the moment it allows
1204 * only 2 entries per bucket. We will see.
1206 if (chain_length > ip_rt_gc_elasticity) {
1207 *candp = cand->u.dst.rt_next;
1211 if (chain_length > rt_chain_length_max &&
1212 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1213 struct net *net = dev_net(rt->u.dst.dev);
1214 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1215 if (!rt_caching(dev_net(rt->u.dst.dev))) {
1216 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1217 rt->u.dst.dev->name, num);
1219 rt_emergency_hash_rebuild(dev_net(rt->u.dst.dev));
1223 /* Try to bind route to arp only if it is output
1224 route or unicast forwarding path.
1226 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1227 int err = arp_bind_neighbour(&rt->u.dst);
1229 spin_unlock_bh(rt_hash_lock_addr(hash));
1231 if (err != -ENOBUFS) {
1236 /* Neighbour tables are full and nothing
1237 can be released. Try to shrink route cache,
1238 it is most likely it holds some neighbour records.
1240 if (attempts-- > 0) {
1241 int saved_elasticity = ip_rt_gc_elasticity;
1242 int saved_int = ip_rt_gc_min_interval;
1243 ip_rt_gc_elasticity = 1;
1244 ip_rt_gc_min_interval = 0;
1245 rt_garbage_collect(&ipv4_dst_ops);
1246 ip_rt_gc_min_interval = saved_int;
1247 ip_rt_gc_elasticity = saved_elasticity;
1251 if (net_ratelimit())
1252 printk(KERN_WARNING "Neighbour table overflow.\n");
1258 rt->u.dst.rt_next = rt_hash_table[hash].chain;
1260 #if RT_CACHE_DEBUG >= 2
1261 if (rt->u.dst.rt_next) {
1263 printk(KERN_DEBUG "rt_cache @%02x: %pI4",
1265 for (trt = rt->u.dst.rt_next; trt; trt = trt->u.dst.rt_next)
1266 printk(" . %pI4", &trt->rt_dst);
1271 * Since lookup is lockfree, we must make sure
1272 * previous writes to rt are comitted to memory
1273 * before making rt visible to other CPUS.
1275 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1277 spin_unlock_bh(rt_hash_lock_addr(hash));
1283 skb_dst_set(skb, &rt->u.dst);
1287 void rt_bind_peer(struct rtable *rt, int create)
1289 static DEFINE_SPINLOCK(rt_peer_lock);
1290 struct inet_peer *peer;
1292 peer = inet_getpeer(rt->rt_dst, create);
1294 spin_lock_bh(&rt_peer_lock);
1295 if (rt->peer == NULL) {
1299 spin_unlock_bh(&rt_peer_lock);
1305 * Peer allocation may fail only in serious out-of-memory conditions. However
1306 * we still can generate some output.
1307 * Random ID selection looks a bit dangerous because we have no chances to
1308 * select ID being unique in a reasonable period of time.
1309 * But broken packet identifier may be better than no packet at all.
1311 static void ip_select_fb_ident(struct iphdr *iph)
1313 static DEFINE_SPINLOCK(ip_fb_id_lock);
1314 static u32 ip_fallback_id;
1317 spin_lock_bh(&ip_fb_id_lock);
1318 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1319 iph->id = htons(salt & 0xFFFF);
1320 ip_fallback_id = salt;
1321 spin_unlock_bh(&ip_fb_id_lock);
1324 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1326 struct rtable *rt = (struct rtable *) dst;
1329 if (rt->peer == NULL)
1330 rt_bind_peer(rt, 1);
1332 /* If peer is attached to destination, it is never detached,
1333 so that we need not to grab a lock to dereference it.
1336 iph->id = htons(inet_getid(rt->peer, more));
1340 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1341 __builtin_return_address(0));
1343 ip_select_fb_ident(iph);
1346 static void rt_del(unsigned hash, struct rtable *rt)
1348 struct rtable **rthp, *aux;
1350 rthp = &rt_hash_table[hash].chain;
1351 spin_lock_bh(rt_hash_lock_addr(hash));
1353 while ((aux = *rthp) != NULL) {
1354 if (aux == rt || rt_is_expired(aux)) {
1355 *rthp = aux->u.dst.rt_next;
1359 rthp = &aux->u.dst.rt_next;
1361 spin_unlock_bh(rt_hash_lock_addr(hash));
1364 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1365 __be32 saddr, struct net_device *dev)
1368 struct in_device *in_dev = in_dev_get(dev);
1369 struct rtable *rth, **rthp;
1370 __be32 skeys[2] = { saddr, 0 };
1371 int ikeys[2] = { dev->ifindex, 0 };
1372 struct netevent_redirect netevent;
1379 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1380 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1381 ipv4_is_zeronet(new_gw))
1382 goto reject_redirect;
1384 if (!rt_caching(net))
1385 goto reject_redirect;
1387 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1388 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1389 goto reject_redirect;
1390 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1391 goto reject_redirect;
1393 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1394 goto reject_redirect;
1397 for (i = 0; i < 2; i++) {
1398 for (k = 0; k < 2; k++) {
1399 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1402 rthp=&rt_hash_table[hash].chain;
1405 while ((rth = rcu_dereference(*rthp)) != NULL) {
1408 if (rth->fl.fl4_dst != daddr ||
1409 rth->fl.fl4_src != skeys[i] ||
1410 rth->fl.oif != ikeys[k] ||
1412 rt_is_expired(rth) ||
1413 !net_eq(dev_net(rth->u.dst.dev), net)) {
1414 rthp = &rth->u.dst.rt_next;
1418 if (rth->rt_dst != daddr ||
1419 rth->rt_src != saddr ||
1421 rth->rt_gateway != old_gw ||
1422 rth->u.dst.dev != dev)
1425 dst_hold(&rth->u.dst);
1428 rt = dst_alloc(&ipv4_dst_ops);
1435 /* Copy all the information. */
1437 rt->u.dst.__use = 1;
1438 atomic_set(&rt->u.dst.__refcnt, 1);
1439 rt->u.dst.child = NULL;
1441 dev_hold(rt->u.dst.dev);
1443 in_dev_hold(rt->idev);
1444 rt->u.dst.obsolete = -1;
1445 rt->u.dst.lastuse = jiffies;
1446 rt->u.dst.path = &rt->u.dst;
1447 rt->u.dst.neighbour = NULL;
1448 rt->u.dst.hh = NULL;
1450 rt->u.dst.xfrm = NULL;
1452 rt->rt_genid = rt_genid(net);
1453 rt->rt_flags |= RTCF_REDIRECTED;
1455 /* Gateway is different ... */
1456 rt->rt_gateway = new_gw;
1458 /* Redirect received -> path was valid */
1459 dst_confirm(&rth->u.dst);
1462 atomic_inc(&rt->peer->refcnt);
1464 if (arp_bind_neighbour(&rt->u.dst) ||
1465 !(rt->u.dst.neighbour->nud_state &
1467 if (rt->u.dst.neighbour)
1468 neigh_event_send(rt->u.dst.neighbour, NULL);
1474 netevent.old = &rth->u.dst;
1475 netevent.new = &rt->u.dst;
1476 call_netevent_notifiers(NETEVENT_REDIRECT,
1480 if (!rt_intern_hash(hash, rt, &rt, NULL))
1493 #ifdef CONFIG_IP_ROUTE_VERBOSE
1494 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1495 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1496 " Advised path = %pI4 -> %pI4\n",
1497 &old_gw, dev->name, &new_gw,
1503 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1505 struct rtable *rt = (struct rtable *)dst;
1506 struct dst_entry *ret = dst;
1509 if (dst->obsolete > 0) {
1512 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
1513 rt->u.dst.expires) {
1514 unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1516 rt_genid(dev_net(dst->dev)));
1517 #if RT_CACHE_DEBUG >= 1
1518 printk(KERN_DEBUG "ipv4_negative_advice: redirect to %pI4/%02x dropped\n",
1519 &rt->rt_dst, rt->fl.fl4_tos);
1530 * 1. The first ip_rt_redirect_number redirects are sent
1531 * with exponential backoff, then we stop sending them at all,
1532 * assuming that the host ignores our redirects.
1533 * 2. If we did not see packets requiring redirects
1534 * during ip_rt_redirect_silence, we assume that the host
1535 * forgot redirected route and start to send redirects again.
1537 * This algorithm is much cheaper and more intelligent than dumb load limiting
1540 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1541 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1544 void ip_rt_send_redirect(struct sk_buff *skb)
1546 struct rtable *rt = skb_rtable(skb);
1547 struct in_device *in_dev;
1551 in_dev = __in_dev_get_rcu(rt->u.dst.dev);
1552 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1556 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1559 /* No redirected packets during ip_rt_redirect_silence;
1560 * reset the algorithm.
1562 if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
1563 rt->u.dst.rate_tokens = 0;
1565 /* Too many ignored redirects; do not send anything
1566 * set u.dst.rate_last to the last seen redirected packet.
1568 if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) {
1569 rt->u.dst.rate_last = jiffies;
1573 /* Check for load limit; set rate_last to the latest sent
1576 if (rt->u.dst.rate_tokens == 0 ||
1578 (rt->u.dst.rate_last +
1579 (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
1580 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1581 rt->u.dst.rate_last = jiffies;
1582 ++rt->u.dst.rate_tokens;
1583 #ifdef CONFIG_IP_ROUTE_VERBOSE
1585 rt->u.dst.rate_tokens == ip_rt_redirect_number &&
1587 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1588 &rt->rt_src, rt->rt_iif,
1589 &rt->rt_dst, &rt->rt_gateway);
1594 static int ip_error(struct sk_buff *skb)
1596 struct rtable *rt = skb_rtable(skb);
1600 switch (rt->u.dst.error) {
1605 code = ICMP_HOST_UNREACH;
1608 code = ICMP_NET_UNREACH;
1609 IP_INC_STATS_BH(dev_net(rt->u.dst.dev),
1610 IPSTATS_MIB_INNOROUTES);
1613 code = ICMP_PKT_FILTERED;
1618 rt->u.dst.rate_tokens += now - rt->u.dst.rate_last;
1619 if (rt->u.dst.rate_tokens > ip_rt_error_burst)
1620 rt->u.dst.rate_tokens = ip_rt_error_burst;
1621 rt->u.dst.rate_last = now;
1622 if (rt->u.dst.rate_tokens >= ip_rt_error_cost) {
1623 rt->u.dst.rate_tokens -= ip_rt_error_cost;
1624 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1627 out: kfree_skb(skb);
1632 * The last two values are not from the RFC but
1633 * are needed for AMPRnet AX.25 paths.
1636 static const unsigned short mtu_plateau[] =
1637 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1639 static inline unsigned short guess_mtu(unsigned short old_mtu)
1643 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1644 if (old_mtu > mtu_plateau[i])
1645 return mtu_plateau[i];
1649 unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
1650 unsigned short new_mtu,
1651 struct net_device *dev)
1654 unsigned short old_mtu = ntohs(iph->tot_len);
1656 int ikeys[2] = { dev->ifindex, 0 };
1657 __be32 skeys[2] = { iph->saddr, 0, };
1658 __be32 daddr = iph->daddr;
1659 unsigned short est_mtu = 0;
1661 for (k = 0; k < 2; k++) {
1662 for (i = 0; i < 2; i++) {
1663 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1667 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1668 rth = rcu_dereference(rth->u.dst.rt_next)) {
1669 unsigned short mtu = new_mtu;
1671 if (rth->fl.fl4_dst != daddr ||
1672 rth->fl.fl4_src != skeys[i] ||
1673 rth->rt_dst != daddr ||
1674 rth->rt_src != iph->saddr ||
1675 rth->fl.oif != ikeys[k] ||
1677 dst_metric_locked(&rth->u.dst, RTAX_MTU) ||
1678 !net_eq(dev_net(rth->u.dst.dev), net) ||
1682 if (new_mtu < 68 || new_mtu >= old_mtu) {
1684 /* BSD 4.2 compatibility hack :-( */
1686 old_mtu >= dst_mtu(&rth->u.dst) &&
1687 old_mtu >= 68 + (iph->ihl << 2))
1688 old_mtu -= iph->ihl << 2;
1690 mtu = guess_mtu(old_mtu);
1692 if (mtu <= dst_mtu(&rth->u.dst)) {
1693 if (mtu < dst_mtu(&rth->u.dst)) {
1694 dst_confirm(&rth->u.dst);
1695 if (mtu < ip_rt_min_pmtu) {
1696 mtu = ip_rt_min_pmtu;
1697 rth->u.dst.metrics[RTAX_LOCK-1] |=
1700 rth->u.dst.metrics[RTAX_MTU-1] = mtu;
1701 dst_set_expires(&rth->u.dst,
1710 return est_mtu ? : new_mtu;
1713 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1715 if (dst_mtu(dst) > mtu && mtu >= 68 &&
1716 !(dst_metric_locked(dst, RTAX_MTU))) {
1717 if (mtu < ip_rt_min_pmtu) {
1718 mtu = ip_rt_min_pmtu;
1719 dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
1721 dst->metrics[RTAX_MTU-1] = mtu;
1722 dst_set_expires(dst, ip_rt_mtu_expires);
1723 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
1727 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1729 if (rt_is_expired((struct rtable *)dst))
1734 static void ipv4_dst_destroy(struct dst_entry *dst)
1736 struct rtable *rt = (struct rtable *) dst;
1737 struct inet_peer *peer = rt->peer;
1738 struct in_device *idev = rt->idev;
1751 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
1754 struct rtable *rt = (struct rtable *) dst;
1755 struct in_device *idev = rt->idev;
1756 if (dev != dev_net(dev)->loopback_dev && idev && idev->dev == dev) {
1757 struct in_device *loopback_idev =
1758 in_dev_get(dev_net(dev)->loopback_dev);
1759 if (loopback_idev) {
1760 rt->idev = loopback_idev;
1766 static void ipv4_link_failure(struct sk_buff *skb)
1770 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1772 rt = skb_rtable(skb);
1774 dst_set_expires(&rt->u.dst, 0);
1777 static int ip_rt_bug(struct sk_buff *skb)
1779 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1780 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1781 skb->dev ? skb->dev->name : "?");
1787 We do not cache source address of outgoing interface,
1788 because it is used only by IP RR, TS and SRR options,
1789 so that it out of fast path.
1791 BTW remember: "addr" is allowed to be not aligned
1795 void ip_rt_get_source(u8 *addr, struct rtable *rt)
1798 struct fib_result res;
1800 if (rt->fl.iif == 0)
1802 else if (fib_lookup(dev_net(rt->u.dst.dev), &rt->fl, &res) == 0) {
1803 src = FIB_RES_PREFSRC(res);
1806 src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway,
1808 memcpy(addr, &src, 4);
1811 #ifdef CONFIG_NET_CLS_ROUTE
1812 static void set_class_tag(struct rtable *rt, u32 tag)
1814 if (!(rt->u.dst.tclassid & 0xFFFF))
1815 rt->u.dst.tclassid |= tag & 0xFFFF;
1816 if (!(rt->u.dst.tclassid & 0xFFFF0000))
1817 rt->u.dst.tclassid |= tag & 0xFFFF0000;
1821 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
1823 struct fib_info *fi = res->fi;
1826 if (FIB_RES_GW(*res) &&
1827 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1828 rt->rt_gateway = FIB_RES_GW(*res);
1829 memcpy(rt->u.dst.metrics, fi->fib_metrics,
1830 sizeof(rt->u.dst.metrics));
1831 if (fi->fib_mtu == 0) {
1832 rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
1833 if (dst_metric_locked(&rt->u.dst, RTAX_MTU) &&
1834 rt->rt_gateway != rt->rt_dst &&
1835 rt->u.dst.dev->mtu > 576)
1836 rt->u.dst.metrics[RTAX_MTU-1] = 576;
1838 #ifdef CONFIG_NET_CLS_ROUTE
1839 rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
1842 rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu;
1844 if (dst_metric(&rt->u.dst, RTAX_HOPLIMIT) == 0)
1845 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
1846 if (dst_mtu(&rt->u.dst) > IP_MAX_MTU)
1847 rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
1848 if (dst_metric(&rt->u.dst, RTAX_ADVMSS) == 0)
1849 rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40,
1851 if (dst_metric(&rt->u.dst, RTAX_ADVMSS) > 65535 - 40)
1852 rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
1854 #ifdef CONFIG_NET_CLS_ROUTE
1855 #ifdef CONFIG_IP_MULTIPLE_TABLES
1856 set_class_tag(rt, fib_rules_tclass(res));
1858 set_class_tag(rt, itag);
1860 rt->rt_type = res->type;
1863 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1864 u8 tos, struct net_device *dev, int our)
1869 struct in_device *in_dev = in_dev_get(dev);
1872 /* Primary sanity checks. */
1877 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1878 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1881 if (ipv4_is_zeronet(saddr)) {
1882 if (!ipv4_is_local_multicast(daddr))
1884 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1885 } else if (fib_validate_source(saddr, 0, tos, 0,
1886 dev, &spec_dst, &itag, 0) < 0)
1889 rth = dst_alloc(&ipv4_dst_ops);
1893 rth->u.dst.output = ip_rt_bug;
1894 rth->u.dst.obsolete = -1;
1896 atomic_set(&rth->u.dst.__refcnt, 1);
1897 rth->u.dst.flags= DST_HOST;
1898 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1899 rth->u.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->u.dst.tclassid = itag;
1910 rth->fl.iif = dev->ifindex;
1911 rth->u.dst.dev = init_net.loopback_dev;
1912 dev_hold(rth->u.dst.dev);
1913 rth->idev = in_dev_get(rth->u.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->u.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->u.dst.input = ip_mr_input;
1929 RT_CACHE_STAT_INC(in_slow_mc);
1932 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1933 return rt_intern_hash(hash, rth, NULL, skb);
1945 static void ip_handle_martian_source(struct net_device *dev,
1946 struct in_device *in_dev,
1947 struct sk_buff *skb,
1951 RT_CACHE_STAT_INC(in_martian_src);
1952 #ifdef CONFIG_IP_ROUTE_VERBOSE
1953 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1955 * RFC1812 recommendation, if source is martian,
1956 * the only hint is MAC header.
1958 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1959 &daddr, &saddr, dev->name);
1960 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1962 const unsigned char *p = skb_mac_header(skb);
1963 printk(KERN_WARNING "ll header: ");
1964 for (i = 0; i < dev->hard_header_len; i++, p++) {
1966 if (i < (dev->hard_header_len - 1))
1975 static int __mkroute_input(struct sk_buff *skb,
1976 struct fib_result *res,
1977 struct in_device *in_dev,
1978 __be32 daddr, __be32 saddr, u32 tos,
1979 struct rtable **result)
1984 struct in_device *out_dev;
1989 /* get a working reference to the output device */
1990 out_dev = in_dev_get(FIB_RES_DEV(*res));
1991 if (out_dev == NULL) {
1992 if (net_ratelimit())
1993 printk(KERN_CRIT "Bug in ip_route_input" \
1994 "_slow(). Please, report\n");
1999 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
2000 in_dev->dev, &spec_dst, &itag, skb->mark);
2002 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2010 flags |= RTCF_DIRECTSRC;
2012 if (out_dev == in_dev && err &&
2013 (IN_DEV_SHARED_MEDIA(out_dev) ||
2014 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2015 flags |= RTCF_DOREDIRECT;
2017 if (skb->protocol != htons(ETH_P_IP)) {
2018 /* Not IP (i.e. ARP). Do not create route, if it is
2019 * invalid for proxy arp. DNAT routes are always valid.
2021 * Proxy arp feature have been extended to allow, ARP
2022 * replies back to the same interface, to support
2023 * Private VLAN switch technologies. See arp.c.
2025 if (out_dev == in_dev &&
2026 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2033 rth = dst_alloc(&ipv4_dst_ops);
2039 atomic_set(&rth->u.dst.__refcnt, 1);
2040 rth->u.dst.flags= DST_HOST;
2041 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2042 rth->u.dst.flags |= DST_NOPOLICY;
2043 if (IN_DEV_CONF_GET(out_dev, NOXFRM))
2044 rth->u.dst.flags |= DST_NOXFRM;
2045 rth->fl.fl4_dst = daddr;
2046 rth->rt_dst = daddr;
2047 rth->fl.fl4_tos = tos;
2048 rth->fl.mark = skb->mark;
2049 rth->fl.fl4_src = saddr;
2050 rth->rt_src = saddr;
2051 rth->rt_gateway = daddr;
2053 rth->fl.iif = in_dev->dev->ifindex;
2054 rth->u.dst.dev = (out_dev)->dev;
2055 dev_hold(rth->u.dst.dev);
2056 rth->idev = in_dev_get(rth->u.dst.dev);
2058 rth->rt_spec_dst= spec_dst;
2060 rth->u.dst.obsolete = -1;
2061 rth->u.dst.input = ip_forward;
2062 rth->u.dst.output = ip_output;
2063 rth->rt_genid = rt_genid(dev_net(rth->u.dst.dev));
2065 rt_set_nexthop(rth, res, itag);
2067 rth->rt_flags = flags;
2072 /* release the working reference to the output device */
2073 in_dev_put(out_dev);
2077 static int ip_mkroute_input(struct sk_buff *skb,
2078 struct fib_result *res,
2079 const struct flowi *fl,
2080 struct in_device *in_dev,
2081 __be32 daddr, __be32 saddr, u32 tos)
2083 struct rtable* rth = NULL;
2087 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2088 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
2089 fib_select_multipath(fl, res);
2092 /* create a routing cache entry */
2093 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2097 /* put it into the cache */
2098 hash = rt_hash(daddr, saddr, fl->iif,
2099 rt_genid(dev_net(rth->u.dst.dev)));
2100 return rt_intern_hash(hash, rth, NULL, skb);
2104 * NOTE. We drop all the packets that has local source
2105 * addresses, because every properly looped back packet
2106 * must have correct destination already attached by output routine.
2108 * Such approach solves two big problems:
2109 * 1. Not simplex devices are handled properly.
2110 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2113 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2114 u8 tos, struct net_device *dev)
2116 struct fib_result res;
2117 struct in_device *in_dev = in_dev_get(dev);
2118 struct flowi fl = { .nl_u = { .ip4_u =
2122 .scope = RT_SCOPE_UNIVERSE,
2125 .iif = dev->ifindex };
2128 struct rtable * rth;
2133 struct net * net = dev_net(dev);
2135 /* IP on this device is disabled. */
2140 /* Check for the most weird martians, which can be not detected
2144 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2145 ipv4_is_loopback(saddr))
2146 goto martian_source;
2148 if (daddr == htonl(0xFFFFFFFF) || (saddr == 0 && daddr == 0))
2151 /* Accept zero addresses only to limited broadcast;
2152 * I even do not know to fix it or not. Waiting for complains :-)
2154 if (ipv4_is_zeronet(saddr))
2155 goto martian_source;
2157 if (ipv4_is_lbcast(daddr) || ipv4_is_zeronet(daddr) ||
2158 ipv4_is_loopback(daddr))
2159 goto martian_destination;
2162 * Now we are ready to route packet.
2164 if ((err = fib_lookup(net, &fl, &res)) != 0) {
2165 if (!IN_DEV_FORWARD(in_dev))
2171 RT_CACHE_STAT_INC(in_slow_tot);
2173 if (res.type == RTN_BROADCAST)
2176 if (res.type == RTN_LOCAL) {
2178 result = fib_validate_source(saddr, daddr, tos,
2179 net->loopback_dev->ifindex,
2180 dev, &spec_dst, &itag, skb->mark);
2182 goto martian_source;
2184 flags |= RTCF_DIRECTSRC;
2189 if (!IN_DEV_FORWARD(in_dev))
2191 if (res.type != RTN_UNICAST)
2192 goto martian_destination;
2194 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
2202 if (skb->protocol != htons(ETH_P_IP))
2205 if (ipv4_is_zeronet(saddr))
2206 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2208 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
2211 goto martian_source;
2213 flags |= RTCF_DIRECTSRC;
2215 flags |= RTCF_BROADCAST;
2216 res.type = RTN_BROADCAST;
2217 RT_CACHE_STAT_INC(in_brd);
2220 rth = dst_alloc(&ipv4_dst_ops);
2224 rth->u.dst.output= ip_rt_bug;
2225 rth->u.dst.obsolete = -1;
2226 rth->rt_genid = rt_genid(net);
2228 atomic_set(&rth->u.dst.__refcnt, 1);
2229 rth->u.dst.flags= DST_HOST;
2230 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2231 rth->u.dst.flags |= DST_NOPOLICY;
2232 rth->fl.fl4_dst = daddr;
2233 rth->rt_dst = daddr;
2234 rth->fl.fl4_tos = tos;
2235 rth->fl.mark = skb->mark;
2236 rth->fl.fl4_src = saddr;
2237 rth->rt_src = saddr;
2238 #ifdef CONFIG_NET_CLS_ROUTE
2239 rth->u.dst.tclassid = itag;
2242 rth->fl.iif = dev->ifindex;
2243 rth->u.dst.dev = net->loopback_dev;
2244 dev_hold(rth->u.dst.dev);
2245 rth->idev = in_dev_get(rth->u.dst.dev);
2246 rth->rt_gateway = daddr;
2247 rth->rt_spec_dst= spec_dst;
2248 rth->u.dst.input= ip_local_deliver;
2249 rth->rt_flags = flags|RTCF_LOCAL;
2250 if (res.type == RTN_UNREACHABLE) {
2251 rth->u.dst.input= ip_error;
2252 rth->u.dst.error= -err;
2253 rth->rt_flags &= ~RTCF_LOCAL;
2255 rth->rt_type = res.type;
2256 hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
2257 err = rt_intern_hash(hash, rth, NULL, skb);
2261 RT_CACHE_STAT_INC(in_no_route);
2262 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2263 res.type = RTN_UNREACHABLE;
2269 * Do not cache martian addresses: they should be logged (RFC1812)
2271 martian_destination:
2272 RT_CACHE_STAT_INC(in_martian_dst);
2273 #ifdef CONFIG_IP_ROUTE_VERBOSE
2274 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2275 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2276 &daddr, &saddr, dev->name);
2280 err = -EHOSTUNREACH;
2292 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2296 int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2297 u8 tos, struct net_device *dev)
2299 struct rtable * rth;
2301 int iif = dev->ifindex;
2306 if (!rt_caching(net))
2309 tos &= IPTOS_RT_MASK;
2310 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2313 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2314 rth = rcu_dereference(rth->u.dst.rt_next)) {
2315 if (((rth->fl.fl4_dst ^ daddr) |
2316 (rth->fl.fl4_src ^ saddr) |
2317 (rth->fl.iif ^ iif) |
2319 (rth->fl.fl4_tos ^ tos)) == 0 &&
2320 rth->fl.mark == skb->mark &&
2321 net_eq(dev_net(rth->u.dst.dev), net) &&
2322 !rt_is_expired(rth)) {
2323 dst_use(&rth->u.dst, jiffies);
2324 RT_CACHE_STAT_INC(in_hit);
2326 skb_dst_set(skb, &rth->u.dst);
2329 RT_CACHE_STAT_INC(in_hlist_search);
2334 /* Multicast recognition logic is moved from route cache to here.
2335 The problem was that too many Ethernet cards have broken/missing
2336 hardware multicast filters :-( As result the host on multicasting
2337 network acquires a lot of useless route cache entries, sort of
2338 SDR messages from all the world. Now we try to get rid of them.
2339 Really, provided software IP multicast filter is organized
2340 reasonably (at least, hashed), it does not result in a slowdown
2341 comparing with route cache reject entries.
2342 Note, that multicast routers are not affected, because
2343 route cache entry is created eventually.
2345 if (ipv4_is_multicast(daddr)) {
2346 struct in_device *in_dev;
2349 if ((in_dev = __in_dev_get_rcu(dev)) != NULL) {
2350 int our = ip_check_mc(in_dev, daddr, saddr,
2351 ip_hdr(skb)->protocol);
2353 #ifdef CONFIG_IP_MROUTE
2355 (!ipv4_is_local_multicast(daddr) &&
2356 IN_DEV_MFORWARD(in_dev))
2360 return ip_route_input_mc(skb, daddr, saddr,
2367 return ip_route_input_slow(skb, daddr, saddr, tos, dev);
2370 static int __mkroute_output(struct rtable **result,
2371 struct fib_result *res,
2372 const struct flowi *fl,
2373 const struct flowi *oldflp,
2374 struct net_device *dev_out,
2378 struct in_device *in_dev;
2379 u32 tos = RT_FL_TOS(oldflp);
2382 if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
2385 if (fl->fl4_dst == htonl(0xFFFFFFFF))
2386 res->type = RTN_BROADCAST;
2387 else if (ipv4_is_multicast(fl->fl4_dst))
2388 res->type = RTN_MULTICAST;
2389 else if (ipv4_is_lbcast(fl->fl4_dst) || ipv4_is_zeronet(fl->fl4_dst))
2392 if (dev_out->flags & IFF_LOOPBACK)
2393 flags |= RTCF_LOCAL;
2395 /* get work reference to inet device */
2396 in_dev = in_dev_get(dev_out);
2400 if (res->type == RTN_BROADCAST) {
2401 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2403 fib_info_put(res->fi);
2406 } else if (res->type == RTN_MULTICAST) {
2407 flags |= RTCF_MULTICAST|RTCF_LOCAL;
2408 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2410 flags &= ~RTCF_LOCAL;
2411 /* If multicast route do not exist use
2412 default one, but do not gateway in this case.
2415 if (res->fi && res->prefixlen < 4) {
2416 fib_info_put(res->fi);
2422 rth = dst_alloc(&ipv4_dst_ops);
2428 atomic_set(&rth->u.dst.__refcnt, 1);
2429 rth->u.dst.flags= DST_HOST;
2430 if (IN_DEV_CONF_GET(in_dev, NOXFRM))
2431 rth->u.dst.flags |= DST_NOXFRM;
2432 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2433 rth->u.dst.flags |= DST_NOPOLICY;
2435 rth->fl.fl4_dst = oldflp->fl4_dst;
2436 rth->fl.fl4_tos = tos;
2437 rth->fl.fl4_src = oldflp->fl4_src;
2438 rth->fl.oif = oldflp->oif;
2439 rth->fl.mark = oldflp->mark;
2440 rth->rt_dst = fl->fl4_dst;
2441 rth->rt_src = fl->fl4_src;
2442 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2443 /* get references to the devices that are to be hold by the routing
2445 rth->u.dst.dev = dev_out;
2447 rth->idev = in_dev_get(dev_out);
2448 rth->rt_gateway = fl->fl4_dst;
2449 rth->rt_spec_dst= fl->fl4_src;
2451 rth->u.dst.output=ip_output;
2452 rth->u.dst.obsolete = -1;
2453 rth->rt_genid = rt_genid(dev_net(dev_out));
2455 RT_CACHE_STAT_INC(out_slow_tot);
2457 if (flags & RTCF_LOCAL) {
2458 rth->u.dst.input = ip_local_deliver;
2459 rth->rt_spec_dst = fl->fl4_dst;
2461 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2462 rth->rt_spec_dst = fl->fl4_src;
2463 if (flags & RTCF_LOCAL &&
2464 !(dev_out->flags & IFF_LOOPBACK)) {
2465 rth->u.dst.output = ip_mc_output;
2466 RT_CACHE_STAT_INC(out_slow_mc);
2468 #ifdef CONFIG_IP_MROUTE
2469 if (res->type == RTN_MULTICAST) {
2470 if (IN_DEV_MFORWARD(in_dev) &&
2471 !ipv4_is_local_multicast(oldflp->fl4_dst)) {
2472 rth->u.dst.input = ip_mr_input;
2473 rth->u.dst.output = ip_mc_output;
2479 rt_set_nexthop(rth, res, 0);
2481 rth->rt_flags = flags;
2485 /* release work reference to inet device */
2491 static int ip_mkroute_output(struct rtable **rp,
2492 struct fib_result *res,
2493 const struct flowi *fl,
2494 const struct flowi *oldflp,
2495 struct net_device *dev_out,
2498 struct rtable *rth = NULL;
2499 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
2502 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
2503 rt_genid(dev_net(dev_out)));
2504 err = rt_intern_hash(hash, rth, rp, NULL);
2511 * Major route resolver routine.
2514 static int ip_route_output_slow(struct net *net, struct rtable **rp,
2515 const struct flowi *oldflp)
2517 u32 tos = RT_FL_TOS(oldflp);
2518 struct flowi fl = { .nl_u = { .ip4_u =
2519 { .daddr = oldflp->fl4_dst,
2520 .saddr = oldflp->fl4_src,
2521 .tos = tos & IPTOS_RT_MASK,
2522 .scope = ((tos & RTO_ONLINK) ?
2526 .mark = oldflp->mark,
2527 .iif = net->loopback_dev->ifindex,
2528 .oif = oldflp->oif };
2529 struct fib_result res;
2531 struct net_device *dev_out = NULL;
2537 #ifdef CONFIG_IP_MULTIPLE_TABLES
2541 if (oldflp->fl4_src) {
2543 if (ipv4_is_multicast(oldflp->fl4_src) ||
2544 ipv4_is_lbcast(oldflp->fl4_src) ||
2545 ipv4_is_zeronet(oldflp->fl4_src))
2548 /* I removed check for oif == dev_out->oif here.
2549 It was wrong for two reasons:
2550 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2551 is assigned to multiple interfaces.
2552 2. Moreover, we are allowed to send packets with saddr
2553 of another iface. --ANK
2556 if (oldflp->oif == 0 &&
2557 (ipv4_is_multicast(oldflp->fl4_dst) ||
2558 oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
2559 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2560 dev_out = ip_dev_find(net, oldflp->fl4_src);
2561 if (dev_out == NULL)
2564 /* Special hack: user can direct multicasts
2565 and limited broadcast via necessary interface
2566 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2567 This hack is not just for fun, it allows
2568 vic,vat and friends to work.
2569 They bind socket to loopback, set ttl to zero
2570 and expect that it will work.
2571 From the viewpoint of routing cache they are broken,
2572 because we are not allowed to build multicast path
2573 with loopback source addr (look, routing cache
2574 cannot know, that ttl is zero, so that packet
2575 will not leave this host and route is valid).
2576 Luckily, this hack is good workaround.
2579 fl.oif = dev_out->ifindex;
2583 if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
2584 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2585 dev_out = ip_dev_find(net, oldflp->fl4_src);
2586 if (dev_out == NULL)
2595 dev_out = dev_get_by_index(net, oldflp->oif);
2597 if (dev_out == NULL)
2600 /* RACE: Check return value of inet_select_addr instead. */
2601 if (__in_dev_get_rtnl(dev_out) == NULL) {
2603 goto out; /* Wrong error code */
2606 if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
2607 oldflp->fl4_dst == htonl(0xFFFFFFFF)) {
2609 fl.fl4_src = inet_select_addr(dev_out, 0,
2614 if (ipv4_is_multicast(oldflp->fl4_dst))
2615 fl.fl4_src = inet_select_addr(dev_out, 0,
2617 else if (!oldflp->fl4_dst)
2618 fl.fl4_src = inet_select_addr(dev_out, 0,
2624 fl.fl4_dst = fl.fl4_src;
2626 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2629 dev_out = net->loopback_dev;
2631 fl.oif = net->loopback_dev->ifindex;
2632 res.type = RTN_LOCAL;
2633 flags |= RTCF_LOCAL;
2637 if (fib_lookup(net, &fl, &res)) {
2640 /* Apparently, routing tables are wrong. Assume,
2641 that the destination is on link.
2644 Because we are allowed to send to iface
2645 even if it has NO routes and NO assigned
2646 addresses. When oif is specified, routing
2647 tables are looked up with only one purpose:
2648 to catch if destination is gatewayed, rather than
2649 direct. Moreover, if MSG_DONTROUTE is set,
2650 we send packet, ignoring both routing tables
2651 and ifaddr state. --ANK
2654 We could make it even if oif is unknown,
2655 likely IPv6, but we do not.
2658 if (fl.fl4_src == 0)
2659 fl.fl4_src = inet_select_addr(dev_out, 0,
2661 res.type = RTN_UNICAST;
2671 if (res.type == RTN_LOCAL) {
2673 fl.fl4_src = fl.fl4_dst;
2676 dev_out = net->loopback_dev;
2678 fl.oif = dev_out->ifindex;
2680 fib_info_put(res.fi);
2682 flags |= RTCF_LOCAL;
2686 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2687 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2688 fib_select_multipath(&fl, &res);
2691 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2692 fib_select_default(net, &fl, &res);
2695 fl.fl4_src = FIB_RES_PREFSRC(res);
2699 dev_out = FIB_RES_DEV(res);
2701 fl.oif = dev_out->ifindex;
2705 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
2715 int __ip_route_output_key(struct net *net, struct rtable **rp,
2716 const struct flowi *flp)
2721 if (!rt_caching(net))
2724 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net));
2727 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2728 rth = rcu_dereference_bh(rth->u.dst.rt_next)) {
2729 if (rth->fl.fl4_dst == flp->fl4_dst &&
2730 rth->fl.fl4_src == flp->fl4_src &&
2732 rth->fl.oif == flp->oif &&
2733 rth->fl.mark == flp->mark &&
2734 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2735 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2736 net_eq(dev_net(rth->u.dst.dev), net) &&
2737 !rt_is_expired(rth)) {
2738 dst_use(&rth->u.dst, jiffies);
2739 RT_CACHE_STAT_INC(out_hit);
2740 rcu_read_unlock_bh();
2744 RT_CACHE_STAT_INC(out_hlist_search);
2746 rcu_read_unlock_bh();
2749 return ip_route_output_slow(net, rp, flp);
2752 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2754 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2758 static struct dst_ops ipv4_dst_blackhole_ops = {
2760 .protocol = cpu_to_be16(ETH_P_IP),
2761 .destroy = ipv4_dst_destroy,
2762 .check = ipv4_dst_check,
2763 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2764 .entries = ATOMIC_INIT(0),
2768 static int ipv4_dst_blackhole(struct net *net, struct rtable **rp, struct flowi *flp)
2770 struct rtable *ort = *rp;
2771 struct rtable *rt = (struct rtable *)
2772 dst_alloc(&ipv4_dst_blackhole_ops);
2775 struct dst_entry *new = &rt->u.dst;
2777 atomic_set(&new->__refcnt, 1);
2779 new->input = dst_discard;
2780 new->output = dst_discard;
2781 memcpy(new->metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));
2783 new->dev = ort->u.dst.dev;
2789 rt->idev = ort->idev;
2791 in_dev_hold(rt->idev);
2792 rt->rt_genid = rt_genid(net);
2793 rt->rt_flags = ort->rt_flags;
2794 rt->rt_type = ort->rt_type;
2795 rt->rt_dst = ort->rt_dst;
2796 rt->rt_src = ort->rt_src;
2797 rt->rt_iif = ort->rt_iif;
2798 rt->rt_gateway = ort->rt_gateway;
2799 rt->rt_spec_dst = ort->rt_spec_dst;
2800 rt->peer = ort->peer;
2802 atomic_inc(&rt->peer->refcnt);
2807 dst_release(&(*rp)->u.dst);
2809 return (rt ? 0 : -ENOMEM);
2812 int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
2813 struct sock *sk, int flags)
2817 if ((err = __ip_route_output_key(net, rp, flp)) != 0)
2822 flp->fl4_src = (*rp)->rt_src;
2824 flp->fl4_dst = (*rp)->rt_dst;
2825 err = __xfrm_lookup(net, (struct dst_entry **)rp, flp, sk,
2826 flags ? XFRM_LOOKUP_WAIT : 0);
2827 if (err == -EREMOTE)
2828 err = ipv4_dst_blackhole(net, rp, flp);
2836 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2838 int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp)
2840 return ip_route_output_flow(net, rp, flp, NULL, 0);
2843 static int rt_fill_info(struct net *net,
2844 struct sk_buff *skb, u32 pid, u32 seq, int event,
2845 int nowait, unsigned int flags)
2847 struct rtable *rt = skb_rtable(skb);
2849 struct nlmsghdr *nlh;
2851 u32 id = 0, ts = 0, tsage = 0, error;
2853 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2857 r = nlmsg_data(nlh);
2858 r->rtm_family = AF_INET;
2859 r->rtm_dst_len = 32;
2861 r->rtm_tos = rt->fl.fl4_tos;
2862 r->rtm_table = RT_TABLE_MAIN;
2863 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2864 r->rtm_type = rt->rt_type;
2865 r->rtm_scope = RT_SCOPE_UNIVERSE;
2866 r->rtm_protocol = RTPROT_UNSPEC;
2867 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2868 if (rt->rt_flags & RTCF_NOTIFY)
2869 r->rtm_flags |= RTM_F_NOTIFY;
2871 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2873 if (rt->fl.fl4_src) {
2874 r->rtm_src_len = 32;
2875 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
2878 NLA_PUT_U32(skb, RTA_OIF, rt->u.dst.dev->ifindex);
2879 #ifdef CONFIG_NET_CLS_ROUTE
2880 if (rt->u.dst.tclassid)
2881 NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid);
2884 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2885 else if (rt->rt_src != rt->fl.fl4_src)
2886 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2888 if (rt->rt_dst != rt->rt_gateway)
2889 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2891 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
2892 goto nla_put_failure;
2894 error = rt->u.dst.error;
2895 expires = rt->u.dst.expires ? rt->u.dst.expires - jiffies : 0;
2897 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2898 if (rt->peer->tcp_ts_stamp) {
2899 ts = rt->peer->tcp_ts;
2900 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2905 #ifdef CONFIG_IP_MROUTE
2906 __be32 dst = rt->rt_dst;
2908 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2909 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2910 int err = ipmr_get_route(net, skb, r, nowait);
2915 goto nla_put_failure;
2917 if (err == -EMSGSIZE)
2918 goto nla_put_failure;
2924 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
2927 if (rtnl_put_cacheinfo(skb, &rt->u.dst, id, ts, tsage,
2928 expires, error) < 0)
2929 goto nla_put_failure;
2931 return nlmsg_end(skb, nlh);
2934 nlmsg_cancel(skb, nlh);
2938 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2940 struct net *net = sock_net(in_skb->sk);
2942 struct nlattr *tb[RTA_MAX+1];
2943 struct rtable *rt = NULL;
2948 struct sk_buff *skb;
2950 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2954 rtm = nlmsg_data(nlh);
2956 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2962 /* Reserve room for dummy headers, this skb can pass
2963 through good chunk of routing engine.
2965 skb_reset_mac_header(skb);
2966 skb_reset_network_header(skb);
2968 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2969 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2970 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2972 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2973 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2974 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2977 struct net_device *dev;
2979 dev = __dev_get_by_index(net, iif);
2985 skb->protocol = htons(ETH_P_IP);
2988 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2991 rt = skb_rtable(skb);
2992 if (err == 0 && rt->u.dst.error)
2993 err = -rt->u.dst.error;
3000 .tos = rtm->rtm_tos,
3003 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
3005 err = ip_route_output_key(net, &rt, &fl);
3011 skb_dst_set(skb, &rt->u.dst);
3012 if (rtm->rtm_flags & RTM_F_NOTIFY)
3013 rt->rt_flags |= RTCF_NOTIFY;
3015 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3016 RTM_NEWROUTE, 0, 0);
3020 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3029 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3036 net = sock_net(skb->sk);
3041 s_idx = idx = cb->args[1];
3042 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3043 if (!rt_hash_table[h].chain)
3046 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3047 rt = rcu_dereference_bh(rt->u.dst.rt_next), idx++) {
3048 if (!net_eq(dev_net(rt->u.dst.dev), net) || idx < s_idx)
3050 if (rt_is_expired(rt))
3052 skb_dst_set(skb, dst_clone(&rt->u.dst));
3053 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3054 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3055 1, NLM_F_MULTI) <= 0) {
3057 rcu_read_unlock_bh();
3062 rcu_read_unlock_bh();
3071 void ip_rt_multicast_event(struct in_device *in_dev)
3073 rt_cache_flush(dev_net(in_dev->dev), 0);
3076 #ifdef CONFIG_SYSCTL
3077 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3078 void __user *buffer,
3079 size_t *lenp, loff_t *ppos)
3086 memcpy(&ctl, __ctl, sizeof(ctl));
3087 ctl.data = &flush_delay;
3088 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3090 net = (struct net *)__ctl->extra1;
3091 rt_cache_flush(net, flush_delay);
3098 static void rt_secret_reschedule(int old)
3101 int new = ip_rt_secret_interval;
3102 int diff = new - old;
3109 int deleted = del_timer_sync(&net->ipv4.rt_secret_timer);
3116 time = net->ipv4.rt_secret_timer.expires - jiffies;
3118 if (time <= 0 || (time += diff) <= 0)
3123 mod_timer(&net->ipv4.rt_secret_timer, jiffies + time);
3128 static int ipv4_sysctl_rt_secret_interval(ctl_table *ctl, int write,
3129 void __user *buffer, size_t *lenp,
3132 int old = ip_rt_secret_interval;
3133 int ret = proc_dointvec_jiffies(ctl, write, buffer, lenp, ppos);
3135 rt_secret_reschedule(old);
3140 static ctl_table ipv4_route_table[] = {
3142 .procname = "gc_thresh",
3143 .data = &ipv4_dst_ops.gc_thresh,
3144 .maxlen = sizeof(int),
3146 .proc_handler = proc_dointvec,
3149 .procname = "max_size",
3150 .data = &ip_rt_max_size,
3151 .maxlen = sizeof(int),
3153 .proc_handler = proc_dointvec,
3156 /* Deprecated. Use gc_min_interval_ms */
3158 .procname = "gc_min_interval",
3159 .data = &ip_rt_gc_min_interval,
3160 .maxlen = sizeof(int),
3162 .proc_handler = proc_dointvec_jiffies,
3165 .procname = "gc_min_interval_ms",
3166 .data = &ip_rt_gc_min_interval,
3167 .maxlen = sizeof(int),
3169 .proc_handler = proc_dointvec_ms_jiffies,
3172 .procname = "gc_timeout",
3173 .data = &ip_rt_gc_timeout,
3174 .maxlen = sizeof(int),
3176 .proc_handler = proc_dointvec_jiffies,
3179 .procname = "gc_interval",
3180 .data = &ip_rt_gc_interval,
3181 .maxlen = sizeof(int),
3183 .proc_handler = proc_dointvec_jiffies,
3186 .procname = "redirect_load",
3187 .data = &ip_rt_redirect_load,
3188 .maxlen = sizeof(int),
3190 .proc_handler = proc_dointvec,
3193 .procname = "redirect_number",
3194 .data = &ip_rt_redirect_number,
3195 .maxlen = sizeof(int),
3197 .proc_handler = proc_dointvec,
3200 .procname = "redirect_silence",
3201 .data = &ip_rt_redirect_silence,
3202 .maxlen = sizeof(int),
3204 .proc_handler = proc_dointvec,
3207 .procname = "error_cost",
3208 .data = &ip_rt_error_cost,
3209 .maxlen = sizeof(int),
3211 .proc_handler = proc_dointvec,
3214 .procname = "error_burst",
3215 .data = &ip_rt_error_burst,
3216 .maxlen = sizeof(int),
3218 .proc_handler = proc_dointvec,
3221 .procname = "gc_elasticity",
3222 .data = &ip_rt_gc_elasticity,
3223 .maxlen = sizeof(int),
3225 .proc_handler = proc_dointvec,
3228 .procname = "mtu_expires",
3229 .data = &ip_rt_mtu_expires,
3230 .maxlen = sizeof(int),
3232 .proc_handler = proc_dointvec_jiffies,
3235 .procname = "min_pmtu",
3236 .data = &ip_rt_min_pmtu,
3237 .maxlen = sizeof(int),
3239 .proc_handler = proc_dointvec,
3242 .procname = "min_adv_mss",
3243 .data = &ip_rt_min_advmss,
3244 .maxlen = sizeof(int),
3246 .proc_handler = proc_dointvec,
3249 .procname = "secret_interval",
3250 .data = &ip_rt_secret_interval,
3251 .maxlen = sizeof(int),
3253 .proc_handler = ipv4_sysctl_rt_secret_interval,
3258 static struct ctl_table empty[1];
3260 static struct ctl_table ipv4_skeleton[] =
3262 { .procname = "route",
3263 .mode = 0555, .child = ipv4_route_table},
3264 { .procname = "neigh",
3265 .mode = 0555, .child = empty},
3269 static __net_initdata struct ctl_path ipv4_path[] = {
3270 { .procname = "net", },
3271 { .procname = "ipv4", },
3275 static struct ctl_table ipv4_route_flush_table[] = {
3277 .procname = "flush",
3278 .maxlen = sizeof(int),
3280 .proc_handler = ipv4_sysctl_rtcache_flush,
3285 static __net_initdata struct ctl_path ipv4_route_path[] = {
3286 { .procname = "net", },
3287 { .procname = "ipv4", },
3288 { .procname = "route", },
3292 static __net_init int sysctl_route_net_init(struct net *net)
3294 struct ctl_table *tbl;
3296 tbl = ipv4_route_flush_table;
3297 if (!net_eq(net, &init_net)) {
3298 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3302 tbl[0].extra1 = net;
3304 net->ipv4.route_hdr =
3305 register_net_sysctl_table(net, ipv4_route_path, tbl);
3306 if (net->ipv4.route_hdr == NULL)
3311 if (tbl != ipv4_route_flush_table)
3317 static __net_exit void sysctl_route_net_exit(struct net *net)
3319 struct ctl_table *tbl;
3321 tbl = net->ipv4.route_hdr->ctl_table_arg;
3322 unregister_net_sysctl_table(net->ipv4.route_hdr);
3323 BUG_ON(tbl == ipv4_route_flush_table);
3327 static __net_initdata struct pernet_operations sysctl_route_ops = {
3328 .init = sysctl_route_net_init,
3329 .exit = sysctl_route_net_exit,
3334 static __net_init int rt_secret_timer_init(struct net *net)
3336 atomic_set(&net->ipv4.rt_genid,
3337 (int) ((num_physpages ^ (num_physpages>>8)) ^
3338 (jiffies ^ (jiffies >> 7))));
3340 net->ipv4.rt_secret_timer.function = rt_secret_rebuild;
3341 net->ipv4.rt_secret_timer.data = (unsigned long)net;
3342 init_timer_deferrable(&net->ipv4.rt_secret_timer);
3344 if (ip_rt_secret_interval) {
3345 net->ipv4.rt_secret_timer.expires =
3346 jiffies + net_random() % ip_rt_secret_interval +
3347 ip_rt_secret_interval;
3348 add_timer(&net->ipv4.rt_secret_timer);
3353 static __net_exit void rt_secret_timer_exit(struct net *net)
3355 del_timer_sync(&net->ipv4.rt_secret_timer);
3358 static __net_initdata struct pernet_operations rt_secret_timer_ops = {
3359 .init = rt_secret_timer_init,
3360 .exit = rt_secret_timer_exit,
3364 #ifdef CONFIG_NET_CLS_ROUTE
3365 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3366 #endif /* CONFIG_NET_CLS_ROUTE */
3368 static __initdata unsigned long rhash_entries;
3369 static int __init set_rhash_entries(char *str)
3373 rhash_entries = simple_strtoul(str, &str, 0);
3376 __setup("rhash_entries=", set_rhash_entries);
3378 int __init ip_rt_init(void)
3382 #ifdef CONFIG_NET_CLS_ROUTE
3383 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3385 panic("IP: failed to allocate ip_rt_acct\n");
3388 ipv4_dst_ops.kmem_cachep =
3389 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3390 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3392 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
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) ?
3403 rhash_entries ? 0 : 512 * 1024);
3404 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3405 rt_hash_lock_init();
3407 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3408 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3413 /* All the timers, started at system startup tend
3414 to synchronize. Perturb it a bit.
3416 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func);
3417 expires_ljiffies = jiffies;
3418 schedule_delayed_work(&expires_work,
3419 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3421 if (register_pernet_subsys(&rt_secret_timer_ops))
3422 printk(KERN_ERR "Unable to setup rt_secret_timer\n");
3424 if (ip_rt_proc_init())
3425 printk(KERN_ERR "Unable to create route proc files\n");
3428 xfrm4_init(ip_rt_max_size);
3430 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3432 #ifdef CONFIG_SYSCTL
3433 register_pernet_subsys(&sysctl_route_ops);
3438 #ifdef CONFIG_SYSCTL
3440 * We really need to sanitize the damn ipv4 init order, then all
3441 * this nonsense will go away.
3443 void __init ip_static_sysctl_init(void)
3445 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3449 EXPORT_SYMBOL(__ip_select_ident);
3450 EXPORT_SYMBOL(ip_route_input);
3451 EXPORT_SYMBOL(ip_route_output_key);