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 net->ipv4.rt_secret_timer.expires += ip_rt_secret_interval;
937 add_timer(&net->ipv4.rt_secret_timer);
941 static void rt_emergency_hash_rebuild(struct net *net)
943 if (net_ratelimit()) {
944 printk(KERN_WARNING "Route hash chain too long!\n");
945 printk(KERN_WARNING "Adjust your secret_interval!\n");
948 rt_secret_rebuild_oneshot(net);
952 Short description of GC goals.
954 We want to build algorithm, which will keep routing cache
955 at some equilibrium point, when number of aged off entries
956 is kept approximately equal to newly generated ones.
958 Current expiration strength is variable "expire".
959 We try to adjust it dynamically, so that if networking
960 is idle expires is large enough to keep enough of warm entries,
961 and when load increases it reduces to limit cache size.
964 static int rt_garbage_collect(struct dst_ops *ops)
966 static unsigned long expire = RT_GC_TIMEOUT;
967 static unsigned long last_gc;
969 static int equilibrium;
970 struct rtable *rth, **rthp;
971 unsigned long now = jiffies;
975 * Garbage collection is pretty expensive,
976 * do not make it too frequently.
979 RT_CACHE_STAT_INC(gc_total);
981 if (now - last_gc < ip_rt_gc_min_interval &&
982 atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
983 RT_CACHE_STAT_INC(gc_ignored);
987 /* Calculate number of entries, which we want to expire now. */
988 goal = atomic_read(&ipv4_dst_ops.entries) -
989 (ip_rt_gc_elasticity << rt_hash_log);
991 if (equilibrium < ipv4_dst_ops.gc_thresh)
992 equilibrium = ipv4_dst_ops.gc_thresh;
993 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
995 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
996 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
999 /* We are in dangerous area. Try to reduce cache really
1002 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
1003 equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
1006 if (now - last_gc >= ip_rt_gc_min_interval)
1010 equilibrium += goal;
1017 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
1018 unsigned long tmo = expire;
1020 k = (k + 1) & rt_hash_mask;
1021 rthp = &rt_hash_table[k].chain;
1022 spin_lock_bh(rt_hash_lock_addr(k));
1023 while ((rth = *rthp) != NULL) {
1024 if (!rt_is_expired(rth) &&
1025 !rt_may_expire(rth, tmo, expire)) {
1027 rthp = &rth->u.dst.rt_next;
1030 *rthp = rth->u.dst.rt_next;
1034 spin_unlock_bh(rt_hash_lock_addr(k));
1043 /* Goal is not achieved. We stop process if:
1045 - if expire reduced to zero. Otherwise, expire is halfed.
1046 - if table is not full.
1047 - if we are called from interrupt.
1048 - jiffies check is just fallback/debug loop breaker.
1049 We will not spin here for long time in any case.
1052 RT_CACHE_STAT_INC(gc_goal_miss);
1058 #if RT_CACHE_DEBUG >= 2
1059 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
1060 atomic_read(&ipv4_dst_ops.entries), goal, i);
1063 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
1065 } while (!in_softirq() && time_before_eq(jiffies, now));
1067 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
1069 if (net_ratelimit())
1070 printk(KERN_WARNING "dst cache overflow\n");
1071 RT_CACHE_STAT_INC(gc_dst_overflow);
1075 expire += ip_rt_gc_min_interval;
1076 if (expire > ip_rt_gc_timeout ||
1077 atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
1078 expire = ip_rt_gc_timeout;
1079 #if RT_CACHE_DEBUG >= 2
1080 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
1081 atomic_read(&ipv4_dst_ops.entries), goal, rover);
1087 * Returns number of entries in a hash chain that have different hash_inputs
1089 static int slow_chain_length(const struct rtable *head)
1092 const struct rtable *rth = head;
1095 length += has_noalias(head, rth);
1096 rth = rth->u.dst.rt_next;
1098 return length >> FRACT_BITS;
1101 static int rt_intern_hash(unsigned hash, struct rtable *rt,
1102 struct rtable **rp, struct sk_buff *skb)
1104 struct rtable *rth, **rthp;
1106 struct rtable *cand, **candp;
1109 int attempts = !in_softirq();
1113 min_score = ~(u32)0;
1118 if (!rt_caching(dev_net(rt->u.dst.dev))) {
1120 * If we're not caching, just tell the caller we
1121 * were successful and don't touch the route. The
1122 * caller hold the sole reference to the cache entry, and
1123 * it will be released when the caller is done with it.
1124 * If we drop it here, the callers have no way to resolve routes
1125 * when we're not caching. Instead, just point *rp at rt, so
1126 * the caller gets a single use out of the route
1127 * Note that we do rt_free on this new route entry, so that
1128 * once its refcount hits zero, we are still able to reap it
1130 * Note also the rt_free uses call_rcu. We don't actually
1131 * need rcu protection here, this is just our path to get
1132 * on the route gc list.
1135 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1136 int err = arp_bind_neighbour(&rt->u.dst);
1138 if (net_ratelimit())
1140 "Neighbour table failure & not caching routes.\n");
1150 rthp = &rt_hash_table[hash].chain;
1152 spin_lock_bh(rt_hash_lock_addr(hash));
1153 while ((rth = *rthp) != NULL) {
1154 if (rt_is_expired(rth)) {
1155 *rthp = rth->u.dst.rt_next;
1159 if (compare_keys(&rth->fl, &rt->fl) && compare_netns(rth, rt)) {
1161 *rthp = rth->u.dst.rt_next;
1163 * Since lookup is lockfree, the deletion
1164 * must be visible to another weakly ordered CPU before
1165 * the insertion at the start of the hash chain.
1167 rcu_assign_pointer(rth->u.dst.rt_next,
1168 rt_hash_table[hash].chain);
1170 * Since lookup is lockfree, the update writes
1171 * must be ordered for consistency on SMP.
1173 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1175 dst_use(&rth->u.dst, now);
1176 spin_unlock_bh(rt_hash_lock_addr(hash));
1182 skb_dst_set(skb, &rth->u.dst);
1186 if (!atomic_read(&rth->u.dst.__refcnt)) {
1187 u32 score = rt_score(rth);
1189 if (score <= min_score) {
1198 rthp = &rth->u.dst.rt_next;
1202 /* ip_rt_gc_elasticity used to be average length of chain
1203 * length, when exceeded gc becomes really aggressive.
1205 * The second limit is less certain. At the moment it allows
1206 * only 2 entries per bucket. We will see.
1208 if (chain_length > ip_rt_gc_elasticity) {
1209 *candp = cand->u.dst.rt_next;
1213 if (chain_length > rt_chain_length_max &&
1214 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1215 struct net *net = dev_net(rt->u.dst.dev);
1216 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1217 if (!rt_caching(dev_net(rt->u.dst.dev))) {
1218 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1219 rt->u.dst.dev->name, num);
1221 rt_emergency_hash_rebuild(dev_net(rt->u.dst.dev));
1225 /* Try to bind route to arp only if it is output
1226 route or unicast forwarding path.
1228 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1229 int err = arp_bind_neighbour(&rt->u.dst);
1231 spin_unlock_bh(rt_hash_lock_addr(hash));
1233 if (err != -ENOBUFS) {
1238 /* Neighbour tables are full and nothing
1239 can be released. Try to shrink route cache,
1240 it is most likely it holds some neighbour records.
1242 if (attempts-- > 0) {
1243 int saved_elasticity = ip_rt_gc_elasticity;
1244 int saved_int = ip_rt_gc_min_interval;
1245 ip_rt_gc_elasticity = 1;
1246 ip_rt_gc_min_interval = 0;
1247 rt_garbage_collect(&ipv4_dst_ops);
1248 ip_rt_gc_min_interval = saved_int;
1249 ip_rt_gc_elasticity = saved_elasticity;
1253 if (net_ratelimit())
1254 printk(KERN_WARNING "Neighbour table overflow.\n");
1260 rt->u.dst.rt_next = rt_hash_table[hash].chain;
1262 #if RT_CACHE_DEBUG >= 2
1263 if (rt->u.dst.rt_next) {
1265 printk(KERN_DEBUG "rt_cache @%02x: %pI4",
1267 for (trt = rt->u.dst.rt_next; trt; trt = trt->u.dst.rt_next)
1268 printk(" . %pI4", &trt->rt_dst);
1273 * Since lookup is lockfree, we must make sure
1274 * previous writes to rt are comitted to memory
1275 * before making rt visible to other CPUS.
1277 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1279 spin_unlock_bh(rt_hash_lock_addr(hash));
1285 skb_dst_set(skb, &rt->u.dst);
1289 void rt_bind_peer(struct rtable *rt, int create)
1291 static DEFINE_SPINLOCK(rt_peer_lock);
1292 struct inet_peer *peer;
1294 peer = inet_getpeer(rt->rt_dst, create);
1296 spin_lock_bh(&rt_peer_lock);
1297 if (rt->peer == NULL) {
1301 spin_unlock_bh(&rt_peer_lock);
1307 * Peer allocation may fail only in serious out-of-memory conditions. However
1308 * we still can generate some output.
1309 * Random ID selection looks a bit dangerous because we have no chances to
1310 * select ID being unique in a reasonable period of time.
1311 * But broken packet identifier may be better than no packet at all.
1313 static void ip_select_fb_ident(struct iphdr *iph)
1315 static DEFINE_SPINLOCK(ip_fb_id_lock);
1316 static u32 ip_fallback_id;
1319 spin_lock_bh(&ip_fb_id_lock);
1320 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1321 iph->id = htons(salt & 0xFFFF);
1322 ip_fallback_id = salt;
1323 spin_unlock_bh(&ip_fb_id_lock);
1326 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1328 struct rtable *rt = (struct rtable *) dst;
1331 if (rt->peer == NULL)
1332 rt_bind_peer(rt, 1);
1334 /* If peer is attached to destination, it is never detached,
1335 so that we need not to grab a lock to dereference it.
1338 iph->id = htons(inet_getid(rt->peer, more));
1342 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1343 __builtin_return_address(0));
1345 ip_select_fb_ident(iph);
1348 static void rt_del(unsigned hash, struct rtable *rt)
1350 struct rtable **rthp, *aux;
1352 rthp = &rt_hash_table[hash].chain;
1353 spin_lock_bh(rt_hash_lock_addr(hash));
1355 while ((aux = *rthp) != NULL) {
1356 if (aux == rt || rt_is_expired(aux)) {
1357 *rthp = aux->u.dst.rt_next;
1361 rthp = &aux->u.dst.rt_next;
1363 spin_unlock_bh(rt_hash_lock_addr(hash));
1366 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1367 __be32 saddr, struct net_device *dev)
1370 struct in_device *in_dev = in_dev_get(dev);
1371 struct rtable *rth, **rthp;
1372 __be32 skeys[2] = { saddr, 0 };
1373 int ikeys[2] = { dev->ifindex, 0 };
1374 struct netevent_redirect netevent;
1381 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1382 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1383 ipv4_is_zeronet(new_gw))
1384 goto reject_redirect;
1386 if (!rt_caching(net))
1387 goto reject_redirect;
1389 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1390 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1391 goto reject_redirect;
1392 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1393 goto reject_redirect;
1395 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1396 goto reject_redirect;
1399 for (i = 0; i < 2; i++) {
1400 for (k = 0; k < 2; k++) {
1401 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1404 rthp=&rt_hash_table[hash].chain;
1407 while ((rth = rcu_dereference(*rthp)) != NULL) {
1410 if (rth->fl.fl4_dst != daddr ||
1411 rth->fl.fl4_src != skeys[i] ||
1412 rth->fl.oif != ikeys[k] ||
1414 rt_is_expired(rth) ||
1415 !net_eq(dev_net(rth->u.dst.dev), net)) {
1416 rthp = &rth->u.dst.rt_next;
1420 if (rth->rt_dst != daddr ||
1421 rth->rt_src != saddr ||
1423 rth->rt_gateway != old_gw ||
1424 rth->u.dst.dev != dev)
1427 dst_hold(&rth->u.dst);
1430 rt = dst_alloc(&ipv4_dst_ops);
1437 /* Copy all the information. */
1439 rt->u.dst.__use = 1;
1440 atomic_set(&rt->u.dst.__refcnt, 1);
1441 rt->u.dst.child = NULL;
1443 dev_hold(rt->u.dst.dev);
1445 in_dev_hold(rt->idev);
1446 rt->u.dst.obsolete = 0;
1447 rt->u.dst.lastuse = jiffies;
1448 rt->u.dst.path = &rt->u.dst;
1449 rt->u.dst.neighbour = NULL;
1450 rt->u.dst.hh = NULL;
1452 rt->u.dst.xfrm = NULL;
1454 rt->rt_genid = rt_genid(net);
1455 rt->rt_flags |= RTCF_REDIRECTED;
1457 /* Gateway is different ... */
1458 rt->rt_gateway = new_gw;
1460 /* Redirect received -> path was valid */
1461 dst_confirm(&rth->u.dst);
1464 atomic_inc(&rt->peer->refcnt);
1466 if (arp_bind_neighbour(&rt->u.dst) ||
1467 !(rt->u.dst.neighbour->nud_state &
1469 if (rt->u.dst.neighbour)
1470 neigh_event_send(rt->u.dst.neighbour, NULL);
1476 netevent.old = &rth->u.dst;
1477 netevent.new = &rt->u.dst;
1478 call_netevent_notifiers(NETEVENT_REDIRECT,
1482 if (!rt_intern_hash(hash, rt, &rt, NULL))
1495 #ifdef CONFIG_IP_ROUTE_VERBOSE
1496 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1497 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1498 " Advised path = %pI4 -> %pI4\n",
1499 &old_gw, dev->name, &new_gw,
1505 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1507 struct rtable *rt = (struct rtable *)dst;
1508 struct dst_entry *ret = dst;
1511 if (dst->obsolete) {
1514 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
1515 rt->u.dst.expires) {
1516 unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1518 rt_genid(dev_net(dst->dev)));
1519 #if RT_CACHE_DEBUG >= 1
1520 printk(KERN_DEBUG "ipv4_negative_advice: redirect to %pI4/%02x dropped\n",
1521 &rt->rt_dst, rt->fl.fl4_tos);
1532 * 1. The first ip_rt_redirect_number redirects are sent
1533 * with exponential backoff, then we stop sending them at all,
1534 * assuming that the host ignores our redirects.
1535 * 2. If we did not see packets requiring redirects
1536 * during ip_rt_redirect_silence, we assume that the host
1537 * forgot redirected route and start to send redirects again.
1539 * This algorithm is much cheaper and more intelligent than dumb load limiting
1542 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1543 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1546 void ip_rt_send_redirect(struct sk_buff *skb)
1548 struct rtable *rt = skb_rtable(skb);
1549 struct in_device *in_dev;
1553 in_dev = __in_dev_get_rcu(rt->u.dst.dev);
1554 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1558 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1561 /* No redirected packets during ip_rt_redirect_silence;
1562 * reset the algorithm.
1564 if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
1565 rt->u.dst.rate_tokens = 0;
1567 /* Too many ignored redirects; do not send anything
1568 * set u.dst.rate_last to the last seen redirected packet.
1570 if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) {
1571 rt->u.dst.rate_last = jiffies;
1575 /* Check for load limit; set rate_last to the latest sent
1578 if (rt->u.dst.rate_tokens == 0 ||
1580 (rt->u.dst.rate_last +
1581 (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
1582 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1583 rt->u.dst.rate_last = jiffies;
1584 ++rt->u.dst.rate_tokens;
1585 #ifdef CONFIG_IP_ROUTE_VERBOSE
1587 rt->u.dst.rate_tokens == ip_rt_redirect_number &&
1589 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1590 &rt->rt_src, rt->rt_iif,
1591 &rt->rt_dst, &rt->rt_gateway);
1596 static int ip_error(struct sk_buff *skb)
1598 struct rtable *rt = skb_rtable(skb);
1602 switch (rt->u.dst.error) {
1607 code = ICMP_HOST_UNREACH;
1610 code = ICMP_NET_UNREACH;
1611 IP_INC_STATS_BH(dev_net(rt->u.dst.dev),
1612 IPSTATS_MIB_INNOROUTES);
1615 code = ICMP_PKT_FILTERED;
1620 rt->u.dst.rate_tokens += now - rt->u.dst.rate_last;
1621 if (rt->u.dst.rate_tokens > ip_rt_error_burst)
1622 rt->u.dst.rate_tokens = ip_rt_error_burst;
1623 rt->u.dst.rate_last = now;
1624 if (rt->u.dst.rate_tokens >= ip_rt_error_cost) {
1625 rt->u.dst.rate_tokens -= ip_rt_error_cost;
1626 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1629 out: kfree_skb(skb);
1634 * The last two values are not from the RFC but
1635 * are needed for AMPRnet AX.25 paths.
1638 static const unsigned short mtu_plateau[] =
1639 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1641 static inline unsigned short guess_mtu(unsigned short old_mtu)
1645 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1646 if (old_mtu > mtu_plateau[i])
1647 return mtu_plateau[i];
1651 unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
1652 unsigned short new_mtu,
1653 struct net_device *dev)
1656 unsigned short old_mtu = ntohs(iph->tot_len);
1658 int ikeys[2] = { dev->ifindex, 0 };
1659 __be32 skeys[2] = { iph->saddr, 0, };
1660 __be32 daddr = iph->daddr;
1661 unsigned short est_mtu = 0;
1663 for (k = 0; k < 2; k++) {
1664 for (i = 0; i < 2; i++) {
1665 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1669 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1670 rth = rcu_dereference(rth->u.dst.rt_next)) {
1671 unsigned short mtu = new_mtu;
1673 if (rth->fl.fl4_dst != daddr ||
1674 rth->fl.fl4_src != skeys[i] ||
1675 rth->rt_dst != daddr ||
1676 rth->rt_src != iph->saddr ||
1677 rth->fl.oif != ikeys[k] ||
1679 dst_metric_locked(&rth->u.dst, RTAX_MTU) ||
1680 !net_eq(dev_net(rth->u.dst.dev), net) ||
1684 if (new_mtu < 68 || new_mtu >= old_mtu) {
1686 /* BSD 4.2 compatibility hack :-( */
1688 old_mtu >= dst_mtu(&rth->u.dst) &&
1689 old_mtu >= 68 + (iph->ihl << 2))
1690 old_mtu -= iph->ihl << 2;
1692 mtu = guess_mtu(old_mtu);
1694 if (mtu <= dst_mtu(&rth->u.dst)) {
1695 if (mtu < dst_mtu(&rth->u.dst)) {
1696 dst_confirm(&rth->u.dst);
1697 if (mtu < ip_rt_min_pmtu) {
1698 mtu = ip_rt_min_pmtu;
1699 rth->u.dst.metrics[RTAX_LOCK-1] |=
1702 rth->u.dst.metrics[RTAX_MTU-1] = mtu;
1703 dst_set_expires(&rth->u.dst,
1712 return est_mtu ? : new_mtu;
1715 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1717 if (dst_mtu(dst) > mtu && mtu >= 68 &&
1718 !(dst_metric_locked(dst, RTAX_MTU))) {
1719 if (mtu < ip_rt_min_pmtu) {
1720 mtu = ip_rt_min_pmtu;
1721 dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
1723 dst->metrics[RTAX_MTU-1] = mtu;
1724 dst_set_expires(dst, ip_rt_mtu_expires);
1725 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
1729 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
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;
1895 atomic_set(&rth->u.dst.__refcnt, 1);
1896 rth->u.dst.flags= DST_HOST;
1897 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1898 rth->u.dst.flags |= DST_NOPOLICY;
1899 rth->fl.fl4_dst = daddr;
1900 rth->rt_dst = daddr;
1901 rth->fl.fl4_tos = tos;
1902 rth->fl.mark = skb->mark;
1903 rth->fl.fl4_src = saddr;
1904 rth->rt_src = saddr;
1905 #ifdef CONFIG_NET_CLS_ROUTE
1906 rth->u.dst.tclassid = itag;
1909 rth->fl.iif = dev->ifindex;
1910 rth->u.dst.dev = init_net.loopback_dev;
1911 dev_hold(rth->u.dst.dev);
1912 rth->idev = in_dev_get(rth->u.dst.dev);
1914 rth->rt_gateway = daddr;
1915 rth->rt_spec_dst= spec_dst;
1916 rth->rt_genid = rt_genid(dev_net(dev));
1917 rth->rt_flags = RTCF_MULTICAST;
1918 rth->rt_type = RTN_MULTICAST;
1920 rth->u.dst.input= ip_local_deliver;
1921 rth->rt_flags |= RTCF_LOCAL;
1924 #ifdef CONFIG_IP_MROUTE
1925 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1926 rth->u.dst.input = ip_mr_input;
1928 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);
1944 static void ip_handle_martian_source(struct net_device *dev,
1945 struct in_device *in_dev,
1946 struct sk_buff *skb,
1950 RT_CACHE_STAT_INC(in_martian_src);
1951 #ifdef CONFIG_IP_ROUTE_VERBOSE
1952 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1954 * RFC1812 recommendation, if source is martian,
1955 * the only hint is MAC header.
1957 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1958 &daddr, &saddr, dev->name);
1959 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1961 const unsigned char *p = skb_mac_header(skb);
1962 printk(KERN_WARNING "ll header: ");
1963 for (i = 0; i < dev->hard_header_len; i++, p++) {
1965 if (i < (dev->hard_header_len - 1))
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)
1983 struct in_device *out_dev;
1988 /* get a working reference to the output device */
1989 out_dev = in_dev_get(FIB_RES_DEV(*res));
1990 if (out_dev == NULL) {
1991 if (net_ratelimit())
1992 printk(KERN_CRIT "Bug in ip_route_input" \
1993 "_slow(). Please, report\n");
1998 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
1999 in_dev->dev, &spec_dst, &itag, skb->mark);
2001 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2009 flags |= RTCF_DIRECTSRC;
2011 if (out_dev == in_dev && err &&
2012 (IN_DEV_SHARED_MEDIA(out_dev) ||
2013 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2014 flags |= RTCF_DOREDIRECT;
2016 if (skb->protocol != htons(ETH_P_IP)) {
2017 /* Not IP (i.e. ARP). Do not create route, if it is
2018 * invalid for proxy arp. DNAT routes are always valid.
2020 * Proxy arp feature have been extended to allow, ARP
2021 * replies back to the same interface, to support
2022 * Private VLAN switch technologies. See arp.c.
2024 if (out_dev == in_dev &&
2025 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2032 rth = dst_alloc(&ipv4_dst_ops);
2038 atomic_set(&rth->u.dst.__refcnt, 1);
2039 rth->u.dst.flags= DST_HOST;
2040 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2041 rth->u.dst.flags |= DST_NOPOLICY;
2042 if (IN_DEV_CONF_GET(out_dev, NOXFRM))
2043 rth->u.dst.flags |= DST_NOXFRM;
2044 rth->fl.fl4_dst = daddr;
2045 rth->rt_dst = daddr;
2046 rth->fl.fl4_tos = tos;
2047 rth->fl.mark = skb->mark;
2048 rth->fl.fl4_src = saddr;
2049 rth->rt_src = saddr;
2050 rth->rt_gateway = daddr;
2052 rth->fl.iif = in_dev->dev->ifindex;
2053 rth->u.dst.dev = (out_dev)->dev;
2054 dev_hold(rth->u.dst.dev);
2055 rth->idev = in_dev_get(rth->u.dst.dev);
2057 rth->rt_spec_dst= spec_dst;
2059 rth->u.dst.input = ip_forward;
2060 rth->u.dst.output = ip_output;
2061 rth->rt_genid = rt_genid(dev_net(rth->u.dst.dev));
2063 rt_set_nexthop(rth, res, itag);
2065 rth->rt_flags = flags;
2070 /* release the working reference to the output device */
2071 in_dev_put(out_dev);
2075 static int ip_mkroute_input(struct sk_buff *skb,
2076 struct fib_result *res,
2077 const struct flowi *fl,
2078 struct in_device *in_dev,
2079 __be32 daddr, __be32 saddr, u32 tos)
2081 struct rtable* rth = NULL;
2085 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2086 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
2087 fib_select_multipath(fl, res);
2090 /* create a routing cache entry */
2091 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2095 /* put it into the cache */
2096 hash = rt_hash(daddr, saddr, fl->iif,
2097 rt_genid(dev_net(rth->u.dst.dev)));
2098 return rt_intern_hash(hash, rth, NULL, skb);
2102 * NOTE. We drop all the packets that has local source
2103 * addresses, because every properly looped back packet
2104 * must have correct destination already attached by output routine.
2106 * Such approach solves two big problems:
2107 * 1. Not simplex devices are handled properly.
2108 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2111 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2112 u8 tos, struct net_device *dev)
2114 struct fib_result res;
2115 struct in_device *in_dev = in_dev_get(dev);
2116 struct flowi fl = { .nl_u = { .ip4_u =
2120 .scope = RT_SCOPE_UNIVERSE,
2123 .iif = dev->ifindex };
2126 struct rtable * rth;
2131 struct net * net = dev_net(dev);
2133 /* IP on this device is disabled. */
2138 /* Check for the most weird martians, which can be not detected
2142 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2143 ipv4_is_loopback(saddr))
2144 goto martian_source;
2146 if (daddr == htonl(0xFFFFFFFF) || (saddr == 0 && daddr == 0))
2149 /* Accept zero addresses only to limited broadcast;
2150 * I even do not know to fix it or not. Waiting for complains :-)
2152 if (ipv4_is_zeronet(saddr))
2153 goto martian_source;
2155 if (ipv4_is_lbcast(daddr) || ipv4_is_zeronet(daddr) ||
2156 ipv4_is_loopback(daddr))
2157 goto martian_destination;
2160 * Now we are ready to route packet.
2162 if ((err = fib_lookup(net, &fl, &res)) != 0) {
2163 if (!IN_DEV_FORWARD(in_dev))
2169 RT_CACHE_STAT_INC(in_slow_tot);
2171 if (res.type == RTN_BROADCAST)
2174 if (res.type == RTN_LOCAL) {
2176 result = fib_validate_source(saddr, daddr, tos,
2177 net->loopback_dev->ifindex,
2178 dev, &spec_dst, &itag, skb->mark);
2180 goto martian_source;
2182 flags |= RTCF_DIRECTSRC;
2187 if (!IN_DEV_FORWARD(in_dev))
2189 if (res.type != RTN_UNICAST)
2190 goto martian_destination;
2192 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
2200 if (skb->protocol != htons(ETH_P_IP))
2203 if (ipv4_is_zeronet(saddr))
2204 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2206 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
2209 goto martian_source;
2211 flags |= RTCF_DIRECTSRC;
2213 flags |= RTCF_BROADCAST;
2214 res.type = RTN_BROADCAST;
2215 RT_CACHE_STAT_INC(in_brd);
2218 rth = dst_alloc(&ipv4_dst_ops);
2222 rth->u.dst.output= ip_rt_bug;
2223 rth->rt_genid = rt_genid(net);
2225 atomic_set(&rth->u.dst.__refcnt, 1);
2226 rth->u.dst.flags= DST_HOST;
2227 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2228 rth->u.dst.flags |= DST_NOPOLICY;
2229 rth->fl.fl4_dst = daddr;
2230 rth->rt_dst = daddr;
2231 rth->fl.fl4_tos = tos;
2232 rth->fl.mark = skb->mark;
2233 rth->fl.fl4_src = saddr;
2234 rth->rt_src = saddr;
2235 #ifdef CONFIG_NET_CLS_ROUTE
2236 rth->u.dst.tclassid = itag;
2239 rth->fl.iif = dev->ifindex;
2240 rth->u.dst.dev = net->loopback_dev;
2241 dev_hold(rth->u.dst.dev);
2242 rth->idev = in_dev_get(rth->u.dst.dev);
2243 rth->rt_gateway = daddr;
2244 rth->rt_spec_dst= spec_dst;
2245 rth->u.dst.input= ip_local_deliver;
2246 rth->rt_flags = flags|RTCF_LOCAL;
2247 if (res.type == RTN_UNREACHABLE) {
2248 rth->u.dst.input= ip_error;
2249 rth->u.dst.error= -err;
2250 rth->rt_flags &= ~RTCF_LOCAL;
2252 rth->rt_type = res.type;
2253 hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
2254 err = rt_intern_hash(hash, rth, NULL, skb);
2258 RT_CACHE_STAT_INC(in_no_route);
2259 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2260 res.type = RTN_UNREACHABLE;
2266 * Do not cache martian addresses: they should be logged (RFC1812)
2268 martian_destination:
2269 RT_CACHE_STAT_INC(in_martian_dst);
2270 #ifdef CONFIG_IP_ROUTE_VERBOSE
2271 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2272 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2273 &daddr, &saddr, dev->name);
2277 err = -EHOSTUNREACH;
2289 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2293 int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2294 u8 tos, struct net_device *dev)
2296 struct rtable * rth;
2298 int iif = dev->ifindex;
2303 if (!rt_caching(net))
2306 tos &= IPTOS_RT_MASK;
2307 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2310 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2311 rth = rcu_dereference(rth->u.dst.rt_next)) {
2312 if (((rth->fl.fl4_dst ^ daddr) |
2313 (rth->fl.fl4_src ^ saddr) |
2314 (rth->fl.iif ^ iif) |
2316 (rth->fl.fl4_tos ^ tos)) == 0 &&
2317 rth->fl.mark == skb->mark &&
2318 net_eq(dev_net(rth->u.dst.dev), net) &&
2319 !rt_is_expired(rth)) {
2320 dst_use(&rth->u.dst, jiffies);
2321 RT_CACHE_STAT_INC(in_hit);
2323 skb_dst_set(skb, &rth->u.dst);
2326 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;
2346 if ((in_dev = __in_dev_get_rcu(dev)) != NULL) {
2347 int our = ip_check_mc(in_dev, daddr, saddr,
2348 ip_hdr(skb)->protocol);
2350 #ifdef CONFIG_IP_MROUTE
2352 (!ipv4_is_local_multicast(daddr) &&
2353 IN_DEV_MFORWARD(in_dev))
2357 return ip_route_input_mc(skb, daddr, saddr,
2364 return ip_route_input_slow(skb, daddr, saddr, tos, dev);
2367 static int __mkroute_output(struct rtable **result,
2368 struct fib_result *res,
2369 const struct flowi *fl,
2370 const struct flowi *oldflp,
2371 struct net_device *dev_out,
2375 struct in_device *in_dev;
2376 u32 tos = RT_FL_TOS(oldflp);
2379 if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
2382 if (fl->fl4_dst == htonl(0xFFFFFFFF))
2383 res->type = RTN_BROADCAST;
2384 else if (ipv4_is_multicast(fl->fl4_dst))
2385 res->type = RTN_MULTICAST;
2386 else if (ipv4_is_lbcast(fl->fl4_dst) || ipv4_is_zeronet(fl->fl4_dst))
2389 if (dev_out->flags & IFF_LOOPBACK)
2390 flags |= RTCF_LOCAL;
2392 /* get work reference to inet device */
2393 in_dev = in_dev_get(dev_out);
2397 if (res->type == RTN_BROADCAST) {
2398 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2400 fib_info_put(res->fi);
2403 } else if (res->type == RTN_MULTICAST) {
2404 flags |= RTCF_MULTICAST|RTCF_LOCAL;
2405 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2407 flags &= ~RTCF_LOCAL;
2408 /* If multicast route do not exist use
2409 default one, but do not gateway in this case.
2412 if (res->fi && res->prefixlen < 4) {
2413 fib_info_put(res->fi);
2419 rth = dst_alloc(&ipv4_dst_ops);
2425 atomic_set(&rth->u.dst.__refcnt, 1);
2426 rth->u.dst.flags= DST_HOST;
2427 if (IN_DEV_CONF_GET(in_dev, NOXFRM))
2428 rth->u.dst.flags |= DST_NOXFRM;
2429 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2430 rth->u.dst.flags |= DST_NOPOLICY;
2432 rth->fl.fl4_dst = oldflp->fl4_dst;
2433 rth->fl.fl4_tos = tos;
2434 rth->fl.fl4_src = oldflp->fl4_src;
2435 rth->fl.oif = oldflp->oif;
2436 rth->fl.mark = oldflp->mark;
2437 rth->rt_dst = fl->fl4_dst;
2438 rth->rt_src = fl->fl4_src;
2439 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2440 /* get references to the devices that are to be hold by the routing
2442 rth->u.dst.dev = dev_out;
2444 rth->idev = in_dev_get(dev_out);
2445 rth->rt_gateway = fl->fl4_dst;
2446 rth->rt_spec_dst= fl->fl4_src;
2448 rth->u.dst.output=ip_output;
2449 rth->rt_genid = rt_genid(dev_net(dev_out));
2451 RT_CACHE_STAT_INC(out_slow_tot);
2453 if (flags & RTCF_LOCAL) {
2454 rth->u.dst.input = ip_local_deliver;
2455 rth->rt_spec_dst = fl->fl4_dst;
2457 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2458 rth->rt_spec_dst = fl->fl4_src;
2459 if (flags & RTCF_LOCAL &&
2460 !(dev_out->flags & IFF_LOOPBACK)) {
2461 rth->u.dst.output = ip_mc_output;
2462 RT_CACHE_STAT_INC(out_slow_mc);
2464 #ifdef CONFIG_IP_MROUTE
2465 if (res->type == RTN_MULTICAST) {
2466 if (IN_DEV_MFORWARD(in_dev) &&
2467 !ipv4_is_local_multicast(oldflp->fl4_dst)) {
2468 rth->u.dst.input = ip_mr_input;
2469 rth->u.dst.output = ip_mc_output;
2475 rt_set_nexthop(rth, res, 0);
2477 rth->rt_flags = flags;
2481 /* release work reference to inet device */
2487 static int ip_mkroute_output(struct rtable **rp,
2488 struct fib_result *res,
2489 const struct flowi *fl,
2490 const struct flowi *oldflp,
2491 struct net_device *dev_out,
2494 struct rtable *rth = NULL;
2495 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
2498 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
2499 rt_genid(dev_net(dev_out)));
2500 err = rt_intern_hash(hash, rth, rp, NULL);
2507 * Major route resolver routine.
2510 static int ip_route_output_slow(struct net *net, struct rtable **rp,
2511 const struct flowi *oldflp)
2513 u32 tos = RT_FL_TOS(oldflp);
2514 struct flowi fl = { .nl_u = { .ip4_u =
2515 { .daddr = oldflp->fl4_dst,
2516 .saddr = oldflp->fl4_src,
2517 .tos = tos & IPTOS_RT_MASK,
2518 .scope = ((tos & RTO_ONLINK) ?
2522 .mark = oldflp->mark,
2523 .iif = net->loopback_dev->ifindex,
2524 .oif = oldflp->oif };
2525 struct fib_result res;
2527 struct net_device *dev_out = NULL;
2533 #ifdef CONFIG_IP_MULTIPLE_TABLES
2537 if (oldflp->fl4_src) {
2539 if (ipv4_is_multicast(oldflp->fl4_src) ||
2540 ipv4_is_lbcast(oldflp->fl4_src) ||
2541 ipv4_is_zeronet(oldflp->fl4_src))
2544 /* I removed check for oif == dev_out->oif here.
2545 It was wrong for two reasons:
2546 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2547 is assigned to multiple interfaces.
2548 2. Moreover, we are allowed to send packets with saddr
2549 of another iface. --ANK
2552 if (oldflp->oif == 0 &&
2553 (ipv4_is_multicast(oldflp->fl4_dst) ||
2554 oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
2555 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2556 dev_out = ip_dev_find(net, oldflp->fl4_src);
2557 if (dev_out == NULL)
2560 /* Special hack: user can direct multicasts
2561 and limited broadcast via necessary interface
2562 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2563 This hack is not just for fun, it allows
2564 vic,vat and friends to work.
2565 They bind socket to loopback, set ttl to zero
2566 and expect that it will work.
2567 From the viewpoint of routing cache they are broken,
2568 because we are not allowed to build multicast path
2569 with loopback source addr (look, routing cache
2570 cannot know, that ttl is zero, so that packet
2571 will not leave this host and route is valid).
2572 Luckily, this hack is good workaround.
2575 fl.oif = dev_out->ifindex;
2579 if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
2580 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2581 dev_out = ip_dev_find(net, oldflp->fl4_src);
2582 if (dev_out == NULL)
2591 dev_out = dev_get_by_index(net, oldflp->oif);
2593 if (dev_out == NULL)
2596 /* RACE: Check return value of inet_select_addr instead. */
2597 if (__in_dev_get_rtnl(dev_out) == NULL) {
2599 goto out; /* Wrong error code */
2602 if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
2603 oldflp->fl4_dst == htonl(0xFFFFFFFF)) {
2605 fl.fl4_src = inet_select_addr(dev_out, 0,
2610 if (ipv4_is_multicast(oldflp->fl4_dst))
2611 fl.fl4_src = inet_select_addr(dev_out, 0,
2613 else if (!oldflp->fl4_dst)
2614 fl.fl4_src = inet_select_addr(dev_out, 0,
2620 fl.fl4_dst = fl.fl4_src;
2622 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2625 dev_out = net->loopback_dev;
2627 fl.oif = net->loopback_dev->ifindex;
2628 res.type = RTN_LOCAL;
2629 flags |= RTCF_LOCAL;
2633 if (fib_lookup(net, &fl, &res)) {
2636 /* Apparently, routing tables are wrong. Assume,
2637 that the destination is on link.
2640 Because we are allowed to send to iface
2641 even if it has NO routes and NO assigned
2642 addresses. When oif is specified, routing
2643 tables are looked up with only one purpose:
2644 to catch if destination is gatewayed, rather than
2645 direct. Moreover, if MSG_DONTROUTE is set,
2646 we send packet, ignoring both routing tables
2647 and ifaddr state. --ANK
2650 We could make it even if oif is unknown,
2651 likely IPv6, but we do not.
2654 if (fl.fl4_src == 0)
2655 fl.fl4_src = inet_select_addr(dev_out, 0,
2657 res.type = RTN_UNICAST;
2667 if (res.type == RTN_LOCAL) {
2669 fl.fl4_src = fl.fl4_dst;
2672 dev_out = net->loopback_dev;
2674 fl.oif = dev_out->ifindex;
2676 fib_info_put(res.fi);
2678 flags |= RTCF_LOCAL;
2682 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2683 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2684 fib_select_multipath(&fl, &res);
2687 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2688 fib_select_default(net, &fl, &res);
2691 fl.fl4_src = FIB_RES_PREFSRC(res);
2695 dev_out = FIB_RES_DEV(res);
2697 fl.oif = dev_out->ifindex;
2701 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
2711 int __ip_route_output_key(struct net *net, struct rtable **rp,
2712 const struct flowi *flp)
2717 if (!rt_caching(net))
2720 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net));
2723 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2724 rth = rcu_dereference_bh(rth->u.dst.rt_next)) {
2725 if (rth->fl.fl4_dst == flp->fl4_dst &&
2726 rth->fl.fl4_src == flp->fl4_src &&
2728 rth->fl.oif == flp->oif &&
2729 rth->fl.mark == flp->mark &&
2730 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2731 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2732 net_eq(dev_net(rth->u.dst.dev), net) &&
2733 !rt_is_expired(rth)) {
2734 dst_use(&rth->u.dst, jiffies);
2735 RT_CACHE_STAT_INC(out_hit);
2736 rcu_read_unlock_bh();
2740 RT_CACHE_STAT_INC(out_hlist_search);
2742 rcu_read_unlock_bh();
2745 return ip_route_output_slow(net, rp, flp);
2748 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2750 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2754 static struct dst_ops ipv4_dst_blackhole_ops = {
2756 .protocol = cpu_to_be16(ETH_P_IP),
2757 .destroy = ipv4_dst_destroy,
2758 .check = ipv4_dst_check,
2759 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2760 .entries = ATOMIC_INIT(0),
2764 static int ipv4_dst_blackhole(struct net *net, struct rtable **rp, struct flowi *flp)
2766 struct rtable *ort = *rp;
2767 struct rtable *rt = (struct rtable *)
2768 dst_alloc(&ipv4_dst_blackhole_ops);
2771 struct dst_entry *new = &rt->u.dst;
2773 atomic_set(&new->__refcnt, 1);
2775 new->input = dst_discard;
2776 new->output = dst_discard;
2777 memcpy(new->metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));
2779 new->dev = ort->u.dst.dev;
2785 rt->idev = ort->idev;
2787 in_dev_hold(rt->idev);
2788 rt->rt_genid = rt_genid(net);
2789 rt->rt_flags = ort->rt_flags;
2790 rt->rt_type = ort->rt_type;
2791 rt->rt_dst = ort->rt_dst;
2792 rt->rt_src = ort->rt_src;
2793 rt->rt_iif = ort->rt_iif;
2794 rt->rt_gateway = ort->rt_gateway;
2795 rt->rt_spec_dst = ort->rt_spec_dst;
2796 rt->peer = ort->peer;
2798 atomic_inc(&rt->peer->refcnt);
2803 dst_release(&(*rp)->u.dst);
2805 return (rt ? 0 : -ENOMEM);
2808 int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
2809 struct sock *sk, int flags)
2813 if ((err = __ip_route_output_key(net, rp, flp)) != 0)
2818 flp->fl4_src = (*rp)->rt_src;
2820 flp->fl4_dst = (*rp)->rt_dst;
2821 err = __xfrm_lookup(net, (struct dst_entry **)rp, flp, sk,
2822 flags ? XFRM_LOOKUP_WAIT : 0);
2823 if (err == -EREMOTE)
2824 err = ipv4_dst_blackhole(net, rp, flp);
2832 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2834 int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp)
2836 return ip_route_output_flow(net, rp, flp, NULL, 0);
2839 static int rt_fill_info(struct net *net,
2840 struct sk_buff *skb, u32 pid, u32 seq, int event,
2841 int nowait, unsigned int flags)
2843 struct rtable *rt = skb_rtable(skb);
2845 struct nlmsghdr *nlh;
2847 u32 id = 0, ts = 0, tsage = 0, error;
2849 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2853 r = nlmsg_data(nlh);
2854 r->rtm_family = AF_INET;
2855 r->rtm_dst_len = 32;
2857 r->rtm_tos = rt->fl.fl4_tos;
2858 r->rtm_table = RT_TABLE_MAIN;
2859 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2860 r->rtm_type = rt->rt_type;
2861 r->rtm_scope = RT_SCOPE_UNIVERSE;
2862 r->rtm_protocol = RTPROT_UNSPEC;
2863 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2864 if (rt->rt_flags & RTCF_NOTIFY)
2865 r->rtm_flags |= RTM_F_NOTIFY;
2867 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2869 if (rt->fl.fl4_src) {
2870 r->rtm_src_len = 32;
2871 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
2874 NLA_PUT_U32(skb, RTA_OIF, rt->u.dst.dev->ifindex);
2875 #ifdef CONFIG_NET_CLS_ROUTE
2876 if (rt->u.dst.tclassid)
2877 NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid);
2880 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2881 else if (rt->rt_src != rt->fl.fl4_src)
2882 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2884 if (rt->rt_dst != rt->rt_gateway)
2885 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2887 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
2888 goto nla_put_failure;
2890 error = rt->u.dst.error;
2891 expires = rt->u.dst.expires ? rt->u.dst.expires - jiffies : 0;
2893 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2894 if (rt->peer->tcp_ts_stamp) {
2895 ts = rt->peer->tcp_ts;
2896 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2901 #ifdef CONFIG_IP_MROUTE
2902 __be32 dst = rt->rt_dst;
2904 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2905 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2906 int err = ipmr_get_route(net, skb, r, nowait);
2911 goto nla_put_failure;
2913 if (err == -EMSGSIZE)
2914 goto nla_put_failure;
2920 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
2923 if (rtnl_put_cacheinfo(skb, &rt->u.dst, id, ts, tsage,
2924 expires, error) < 0)
2925 goto nla_put_failure;
2927 return nlmsg_end(skb, nlh);
2930 nlmsg_cancel(skb, nlh);
2934 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2936 struct net *net = sock_net(in_skb->sk);
2938 struct nlattr *tb[RTA_MAX+1];
2939 struct rtable *rt = NULL;
2944 struct sk_buff *skb;
2946 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2950 rtm = nlmsg_data(nlh);
2952 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2958 /* Reserve room for dummy headers, this skb can pass
2959 through good chunk of routing engine.
2961 skb_reset_mac_header(skb);
2962 skb_reset_network_header(skb);
2964 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2965 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2966 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2968 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2969 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2970 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2973 struct net_device *dev;
2975 dev = __dev_get_by_index(net, iif);
2981 skb->protocol = htons(ETH_P_IP);
2984 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2987 rt = skb_rtable(skb);
2988 if (err == 0 && rt->u.dst.error)
2989 err = -rt->u.dst.error;
2996 .tos = rtm->rtm_tos,
2999 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
3001 err = ip_route_output_key(net, &rt, &fl);
3007 skb_dst_set(skb, &rt->u.dst);
3008 if (rtm->rtm_flags & RTM_F_NOTIFY)
3009 rt->rt_flags |= RTCF_NOTIFY;
3011 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3012 RTM_NEWROUTE, 0, 0);
3016 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3025 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3032 net = sock_net(skb->sk);
3037 s_idx = idx = cb->args[1];
3038 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3039 if (!rt_hash_table[h].chain)
3042 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3043 rt = rcu_dereference_bh(rt->u.dst.rt_next), idx++) {
3044 if (!net_eq(dev_net(rt->u.dst.dev), net) || idx < s_idx)
3046 if (rt_is_expired(rt))
3048 skb_dst_set(skb, dst_clone(&rt->u.dst));
3049 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3050 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3051 1, NLM_F_MULTI) <= 0) {
3053 rcu_read_unlock_bh();
3058 rcu_read_unlock_bh();
3067 void ip_rt_multicast_event(struct in_device *in_dev)
3069 rt_cache_flush(dev_net(in_dev->dev), 0);
3072 #ifdef CONFIG_SYSCTL
3073 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3074 void __user *buffer,
3075 size_t *lenp, loff_t *ppos)
3082 memcpy(&ctl, __ctl, sizeof(ctl));
3083 ctl.data = &flush_delay;
3084 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3086 net = (struct net *)__ctl->extra1;
3087 rt_cache_flush(net, flush_delay);
3094 static void rt_secret_reschedule(int old)
3097 int new = ip_rt_secret_interval;
3098 int diff = new - old;
3105 int deleted = del_timer_sync(&net->ipv4.rt_secret_timer);
3111 long time = net->ipv4.rt_secret_timer.expires - jiffies;
3113 if (time <= 0 || (time += diff) <= 0)
3116 net->ipv4.rt_secret_timer.expires = time;
3118 net->ipv4.rt_secret_timer.expires = new;
3120 net->ipv4.rt_secret_timer.expires += jiffies;
3121 add_timer(&net->ipv4.rt_secret_timer);
3126 static int ipv4_sysctl_rt_secret_interval(ctl_table *ctl, int write,
3127 void __user *buffer, size_t *lenp,
3130 int old = ip_rt_secret_interval;
3131 int ret = proc_dointvec_jiffies(ctl, write, buffer, lenp, ppos);
3133 rt_secret_reschedule(old);
3138 static ctl_table ipv4_route_table[] = {
3140 .procname = "gc_thresh",
3141 .data = &ipv4_dst_ops.gc_thresh,
3142 .maxlen = sizeof(int),
3144 .proc_handler = proc_dointvec,
3147 .procname = "max_size",
3148 .data = &ip_rt_max_size,
3149 .maxlen = sizeof(int),
3151 .proc_handler = proc_dointvec,
3154 /* Deprecated. Use gc_min_interval_ms */
3156 .procname = "gc_min_interval",
3157 .data = &ip_rt_gc_min_interval,
3158 .maxlen = sizeof(int),
3160 .proc_handler = proc_dointvec_jiffies,
3163 .procname = "gc_min_interval_ms",
3164 .data = &ip_rt_gc_min_interval,
3165 .maxlen = sizeof(int),
3167 .proc_handler = proc_dointvec_ms_jiffies,
3170 .procname = "gc_timeout",
3171 .data = &ip_rt_gc_timeout,
3172 .maxlen = sizeof(int),
3174 .proc_handler = proc_dointvec_jiffies,
3177 .procname = "gc_interval",
3178 .data = &ip_rt_gc_interval,
3179 .maxlen = sizeof(int),
3181 .proc_handler = proc_dointvec_jiffies,
3184 .procname = "redirect_load",
3185 .data = &ip_rt_redirect_load,
3186 .maxlen = sizeof(int),
3188 .proc_handler = proc_dointvec,
3191 .procname = "redirect_number",
3192 .data = &ip_rt_redirect_number,
3193 .maxlen = sizeof(int),
3195 .proc_handler = proc_dointvec,
3198 .procname = "redirect_silence",
3199 .data = &ip_rt_redirect_silence,
3200 .maxlen = sizeof(int),
3202 .proc_handler = proc_dointvec,
3205 .procname = "error_cost",
3206 .data = &ip_rt_error_cost,
3207 .maxlen = sizeof(int),
3209 .proc_handler = proc_dointvec,
3212 .procname = "error_burst",
3213 .data = &ip_rt_error_burst,
3214 .maxlen = sizeof(int),
3216 .proc_handler = proc_dointvec,
3219 .procname = "gc_elasticity",
3220 .data = &ip_rt_gc_elasticity,
3221 .maxlen = sizeof(int),
3223 .proc_handler = proc_dointvec,
3226 .procname = "mtu_expires",
3227 .data = &ip_rt_mtu_expires,
3228 .maxlen = sizeof(int),
3230 .proc_handler = proc_dointvec_jiffies,
3233 .procname = "min_pmtu",
3234 .data = &ip_rt_min_pmtu,
3235 .maxlen = sizeof(int),
3237 .proc_handler = proc_dointvec,
3240 .procname = "min_adv_mss",
3241 .data = &ip_rt_min_advmss,
3242 .maxlen = sizeof(int),
3244 .proc_handler = proc_dointvec,
3247 .procname = "secret_interval",
3248 .data = &ip_rt_secret_interval,
3249 .maxlen = sizeof(int),
3251 .proc_handler = ipv4_sysctl_rt_secret_interval,
3256 static struct ctl_table empty[1];
3258 static struct ctl_table ipv4_skeleton[] =
3260 { .procname = "route",
3261 .mode = 0555, .child = ipv4_route_table},
3262 { .procname = "neigh",
3263 .mode = 0555, .child = empty},
3267 static __net_initdata struct ctl_path ipv4_path[] = {
3268 { .procname = "net", },
3269 { .procname = "ipv4", },
3273 static struct ctl_table ipv4_route_flush_table[] = {
3275 .procname = "flush",
3276 .maxlen = sizeof(int),
3278 .proc_handler = ipv4_sysctl_rtcache_flush,
3283 static __net_initdata struct ctl_path ipv4_route_path[] = {
3284 { .procname = "net", },
3285 { .procname = "ipv4", },
3286 { .procname = "route", },
3290 static __net_init int sysctl_route_net_init(struct net *net)
3292 struct ctl_table *tbl;
3294 tbl = ipv4_route_flush_table;
3295 if (!net_eq(net, &init_net)) {
3296 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3300 tbl[0].extra1 = net;
3302 net->ipv4.route_hdr =
3303 register_net_sysctl_table(net, ipv4_route_path, tbl);
3304 if (net->ipv4.route_hdr == NULL)
3309 if (tbl != ipv4_route_flush_table)
3315 static __net_exit void sysctl_route_net_exit(struct net *net)
3317 struct ctl_table *tbl;
3319 tbl = net->ipv4.route_hdr->ctl_table_arg;
3320 unregister_net_sysctl_table(net->ipv4.route_hdr);
3321 BUG_ON(tbl == ipv4_route_flush_table);
3325 static __net_initdata struct pernet_operations sysctl_route_ops = {
3326 .init = sysctl_route_net_init,
3327 .exit = sysctl_route_net_exit,
3332 static __net_init int rt_secret_timer_init(struct net *net)
3334 atomic_set(&net->ipv4.rt_genid,
3335 (int) ((num_physpages ^ (num_physpages>>8)) ^
3336 (jiffies ^ (jiffies >> 7))));
3338 net->ipv4.rt_secret_timer.function = rt_secret_rebuild;
3339 net->ipv4.rt_secret_timer.data = (unsigned long)net;
3340 init_timer_deferrable(&net->ipv4.rt_secret_timer);
3342 if (ip_rt_secret_interval) {
3343 net->ipv4.rt_secret_timer.expires =
3344 jiffies + net_random() % ip_rt_secret_interval +
3345 ip_rt_secret_interval;
3346 add_timer(&net->ipv4.rt_secret_timer);
3351 static __net_exit void rt_secret_timer_exit(struct net *net)
3353 del_timer_sync(&net->ipv4.rt_secret_timer);
3356 static __net_initdata struct pernet_operations rt_secret_timer_ops = {
3357 .init = rt_secret_timer_init,
3358 .exit = rt_secret_timer_exit,
3362 #ifdef CONFIG_NET_CLS_ROUTE
3363 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3364 #endif /* CONFIG_NET_CLS_ROUTE */
3366 static __initdata unsigned long rhash_entries;
3367 static int __init set_rhash_entries(char *str)
3371 rhash_entries = simple_strtoul(str, &str, 0);
3374 __setup("rhash_entries=", set_rhash_entries);
3376 int __init ip_rt_init(void)
3380 #ifdef CONFIG_NET_CLS_ROUTE
3381 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3383 panic("IP: failed to allocate ip_rt_acct\n");
3386 ipv4_dst_ops.kmem_cachep =
3387 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3388 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3390 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3392 rt_hash_table = (struct rt_hash_bucket *)
3393 alloc_large_system_hash("IP route cache",
3394 sizeof(struct rt_hash_bucket),
3396 (totalram_pages >= 128 * 1024) ?
3401 rhash_entries ? 0 : 512 * 1024);
3402 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3403 rt_hash_lock_init();
3405 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3406 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3411 /* All the timers, started at system startup tend
3412 to synchronize. Perturb it a bit.
3414 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func);
3415 expires_ljiffies = jiffies;
3416 schedule_delayed_work(&expires_work,
3417 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3419 if (register_pernet_subsys(&rt_secret_timer_ops))
3420 printk(KERN_ERR "Unable to setup rt_secret_timer\n");
3422 if (ip_rt_proc_init())
3423 printk(KERN_ERR "Unable to create route proc files\n");
3426 xfrm4_init(ip_rt_max_size);
3428 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3430 #ifdef CONFIG_SYSCTL
3431 register_pernet_subsys(&sysctl_route_ops);
3436 #ifdef CONFIG_SYSCTL
3438 * We really need to sanitize the damn ipv4 init order, then all
3439 * this nonsense will go away.
3441 void __init ip_static_sysctl_init(void)
3443 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3447 EXPORT_SYMBOL(__ip_select_ident);
3448 EXPORT_SYMBOL(ip_route_input);
3449 EXPORT_SYMBOL(ip_route_output_key);