2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * ROUTE - implementation of the IP router.
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
65 #include <linux/module.h>
66 #include <asm/uaccess.h>
67 #include <asm/system.h>
68 #include <linux/bitops.h>
69 #include <linux/types.h>
70 #include <linux/kernel.h>
72 #include <linux/bootmem.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/workqueue.h>
83 #include <linux/skbuff.h>
84 #include <linux/inetdevice.h>
85 #include <linux/igmp.h>
86 #include <linux/pkt_sched.h>
87 #include <linux/mroute.h>
88 #include <linux/netfilter_ipv4.h>
89 #include <linux/random.h>
90 #include <linux/jhash.h>
91 #include <linux/rcupdate.h>
92 #include <linux/times.h>
93 #include <linux/slab.h>
95 #include <net/net_namespace.h>
96 #include <net/protocol.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/netevent.h>
107 #include <net/rtnetlink.h>
109 #include <linux/sysctl.h>
112 #define RT_FL_TOS(oldflp) \
113 ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
115 #define IP_MAX_MTU 0xFFF0
117 #define RT_GC_TIMEOUT (300*HZ)
119 static int ip_rt_max_size;
120 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
121 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
122 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
123 static int ip_rt_redirect_number __read_mostly = 9;
124 static int ip_rt_redirect_load __read_mostly = HZ / 50;
125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly = HZ;
127 static int ip_rt_error_burst __read_mostly = 5 * HZ;
128 static int ip_rt_gc_elasticity __read_mostly = 8;
129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
130 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly = 256;
132 static int rt_chain_length_max __read_mostly = 20;
134 static struct delayed_work expires_work;
135 static unsigned long expires_ljiffies;
138 * Interface to generic destination cache.
141 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
142 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
143 static unsigned int ipv4_default_mtu(const struct dst_entry *dst);
144 static void ipv4_dst_destroy(struct dst_entry *dst);
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);
150 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
155 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
157 struct rtable *rt = (struct rtable *) dst;
158 struct inet_peer *peer;
166 u32 *old_p = __DST_METRICS_PTR(old);
167 unsigned long prev, new;
170 if (inet_metrics_new(peer))
171 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
173 new = (unsigned long) p;
174 prev = cmpxchg(&dst->_metrics, old, new);
177 p = __DST_METRICS_PTR(prev);
178 if (prev & DST_METRICS_READ_ONLY)
182 fib_info_put(rt->fi);
190 static struct dst_ops ipv4_dst_ops = {
192 .protocol = cpu_to_be16(ETH_P_IP),
193 .gc = rt_garbage_collect,
194 .check = ipv4_dst_check,
195 .default_advmss = ipv4_default_advmss,
196 .default_mtu = ipv4_default_mtu,
197 .cow_metrics = ipv4_cow_metrics,
198 .destroy = ipv4_dst_destroy,
199 .ifdown = ipv4_dst_ifdown,
200 .negative_advice = ipv4_negative_advice,
201 .link_failure = ipv4_link_failure,
202 .update_pmtu = ip_rt_update_pmtu,
203 .local_out = __ip_local_out,
206 #define ECN_OR_COST(class) TC_PRIO_##class
208 const __u8 ip_tos2prio[16] = {
212 ECN_OR_COST(BESTEFFORT),
218 ECN_OR_COST(INTERACTIVE),
220 ECN_OR_COST(INTERACTIVE),
221 TC_PRIO_INTERACTIVE_BULK,
222 ECN_OR_COST(INTERACTIVE_BULK),
223 TC_PRIO_INTERACTIVE_BULK,
224 ECN_OR_COST(INTERACTIVE_BULK)
232 /* The locking scheme is rather straight forward:
234 * 1) Read-Copy Update protects the buckets of the central route hash.
235 * 2) Only writers remove entries, and they hold the lock
236 * as they look at rtable reference counts.
237 * 3) Only readers acquire references to rtable entries,
238 * they do so with atomic increments and with the
242 struct rt_hash_bucket {
243 struct rtable __rcu *chain;
246 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
247 defined(CONFIG_PROVE_LOCKING)
249 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
250 * The size of this table is a power of two and depends on the number of CPUS.
251 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
253 #ifdef CONFIG_LOCKDEP
254 # define RT_HASH_LOCK_SZ 256
257 # define RT_HASH_LOCK_SZ 4096
259 # define RT_HASH_LOCK_SZ 2048
261 # define RT_HASH_LOCK_SZ 1024
263 # define RT_HASH_LOCK_SZ 512
265 # define RT_HASH_LOCK_SZ 256
269 static spinlock_t *rt_hash_locks;
270 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
272 static __init void rt_hash_lock_init(void)
276 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
279 panic("IP: failed to allocate rt_hash_locks\n");
281 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
282 spin_lock_init(&rt_hash_locks[i]);
285 # define rt_hash_lock_addr(slot) NULL
287 static inline void rt_hash_lock_init(void)
292 static struct rt_hash_bucket *rt_hash_table __read_mostly;
293 static unsigned rt_hash_mask __read_mostly;
294 static unsigned int rt_hash_log __read_mostly;
296 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
297 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
299 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
302 return jhash_3words((__force u32)daddr, (__force u32)saddr,
307 static inline int rt_genid(struct net *net)
309 return atomic_read(&net->ipv4.rt_genid);
312 #ifdef CONFIG_PROC_FS
313 struct rt_cache_iter_state {
314 struct seq_net_private p;
319 static struct rtable *rt_cache_get_first(struct seq_file *seq)
321 struct rt_cache_iter_state *st = seq->private;
322 struct rtable *r = NULL;
324 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
325 if (!rcu_dereference_raw(rt_hash_table[st->bucket].chain))
328 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
330 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
331 r->rt_genid == st->genid)
333 r = rcu_dereference_bh(r->dst.rt_next);
335 rcu_read_unlock_bh();
340 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
343 struct rt_cache_iter_state *st = seq->private;
345 r = rcu_dereference_bh(r->dst.rt_next);
347 rcu_read_unlock_bh();
349 if (--st->bucket < 0)
351 } while (!rcu_dereference_raw(rt_hash_table[st->bucket].chain));
353 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
358 static struct rtable *rt_cache_get_next(struct seq_file *seq,
361 struct rt_cache_iter_state *st = seq->private;
362 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
363 if (dev_net(r->dst.dev) != seq_file_net(seq))
365 if (r->rt_genid == st->genid)
371 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
373 struct rtable *r = rt_cache_get_first(seq);
376 while (pos && (r = rt_cache_get_next(seq, r)))
378 return pos ? NULL : r;
381 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
383 struct rt_cache_iter_state *st = seq->private;
385 return rt_cache_get_idx(seq, *pos - 1);
386 st->genid = rt_genid(seq_file_net(seq));
387 return SEQ_START_TOKEN;
390 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
394 if (v == SEQ_START_TOKEN)
395 r = rt_cache_get_first(seq);
397 r = rt_cache_get_next(seq, v);
402 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
404 if (v && v != SEQ_START_TOKEN)
405 rcu_read_unlock_bh();
408 static int rt_cache_seq_show(struct seq_file *seq, void *v)
410 if (v == SEQ_START_TOKEN)
411 seq_printf(seq, "%-127s\n",
412 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
413 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
416 struct rtable *r = v;
419 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
420 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
421 r->dst.dev ? r->dst.dev->name : "*",
422 (__force u32)r->rt_dst,
423 (__force u32)r->rt_gateway,
424 r->rt_flags, atomic_read(&r->dst.__refcnt),
425 r->dst.__use, 0, (__force u32)r->rt_src,
426 dst_metric_advmss(&r->dst) + 40,
427 dst_metric(&r->dst, RTAX_WINDOW),
428 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
429 dst_metric(&r->dst, RTAX_RTTVAR)),
431 r->dst.hh ? atomic_read(&r->dst.hh->hh_refcnt) : -1,
432 r->dst.hh ? (r->dst.hh->hh_output ==
434 r->rt_spec_dst, &len);
436 seq_printf(seq, "%*s\n", 127 - len, "");
441 static const struct seq_operations rt_cache_seq_ops = {
442 .start = rt_cache_seq_start,
443 .next = rt_cache_seq_next,
444 .stop = rt_cache_seq_stop,
445 .show = rt_cache_seq_show,
448 static int rt_cache_seq_open(struct inode *inode, struct file *file)
450 return seq_open_net(inode, file, &rt_cache_seq_ops,
451 sizeof(struct rt_cache_iter_state));
454 static const struct file_operations rt_cache_seq_fops = {
455 .owner = THIS_MODULE,
456 .open = rt_cache_seq_open,
459 .release = seq_release_net,
463 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
468 return SEQ_START_TOKEN;
470 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
471 if (!cpu_possible(cpu))
474 return &per_cpu(rt_cache_stat, cpu);
479 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
483 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
484 if (!cpu_possible(cpu))
487 return &per_cpu(rt_cache_stat, cpu);
493 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
498 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
500 struct rt_cache_stat *st = v;
502 if (v == SEQ_START_TOKEN) {
503 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");
507 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
508 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
509 dst_entries_get_slow(&ipv4_dst_ops),
532 static const struct seq_operations rt_cpu_seq_ops = {
533 .start = rt_cpu_seq_start,
534 .next = rt_cpu_seq_next,
535 .stop = rt_cpu_seq_stop,
536 .show = rt_cpu_seq_show,
540 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
542 return seq_open(file, &rt_cpu_seq_ops);
545 static const struct file_operations rt_cpu_seq_fops = {
546 .owner = THIS_MODULE,
547 .open = rt_cpu_seq_open,
550 .release = seq_release,
553 #ifdef CONFIG_IP_ROUTE_CLASSID
554 static int rt_acct_proc_show(struct seq_file *m, void *v)
556 struct ip_rt_acct *dst, *src;
559 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
563 for_each_possible_cpu(i) {
564 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
565 for (j = 0; j < 256; j++) {
566 dst[j].o_bytes += src[j].o_bytes;
567 dst[j].o_packets += src[j].o_packets;
568 dst[j].i_bytes += src[j].i_bytes;
569 dst[j].i_packets += src[j].i_packets;
573 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
578 static int rt_acct_proc_open(struct inode *inode, struct file *file)
580 return single_open(file, rt_acct_proc_show, NULL);
583 static const struct file_operations rt_acct_proc_fops = {
584 .owner = THIS_MODULE,
585 .open = rt_acct_proc_open,
588 .release = single_release,
592 static int __net_init ip_rt_do_proc_init(struct net *net)
594 struct proc_dir_entry *pde;
596 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
601 pde = proc_create("rt_cache", S_IRUGO,
602 net->proc_net_stat, &rt_cpu_seq_fops);
606 #ifdef CONFIG_IP_ROUTE_CLASSID
607 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
613 #ifdef CONFIG_IP_ROUTE_CLASSID
615 remove_proc_entry("rt_cache", net->proc_net_stat);
618 remove_proc_entry("rt_cache", net->proc_net);
623 static void __net_exit ip_rt_do_proc_exit(struct net *net)
625 remove_proc_entry("rt_cache", net->proc_net_stat);
626 remove_proc_entry("rt_cache", net->proc_net);
627 #ifdef CONFIG_IP_ROUTE_CLASSID
628 remove_proc_entry("rt_acct", net->proc_net);
632 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
633 .init = ip_rt_do_proc_init,
634 .exit = ip_rt_do_proc_exit,
637 static int __init ip_rt_proc_init(void)
639 return register_pernet_subsys(&ip_rt_proc_ops);
643 static inline int ip_rt_proc_init(void)
647 #endif /* CONFIG_PROC_FS */
649 static inline void rt_free(struct rtable *rt)
651 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
654 static inline void rt_drop(struct rtable *rt)
657 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
660 static inline int rt_fast_clean(struct rtable *rth)
662 /* Kill broadcast/multicast entries very aggresively, if they
663 collide in hash table with more useful entries */
664 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
665 rt_is_input_route(rth) && rth->dst.rt_next;
668 static inline int rt_valuable(struct rtable *rth)
670 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
674 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
679 if (atomic_read(&rth->dst.__refcnt))
683 if (rth->dst.expires &&
684 time_after_eq(jiffies, rth->dst.expires))
687 age = jiffies - rth->dst.lastuse;
689 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
690 (age <= tmo2 && rt_valuable(rth)))
696 /* Bits of score are:
698 * 30: not quite useless
699 * 29..0: usage counter
701 static inline u32 rt_score(struct rtable *rt)
703 u32 score = jiffies - rt->dst.lastuse;
705 score = ~score & ~(3<<30);
710 if (rt_is_output_route(rt) ||
711 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
717 static inline bool rt_caching(const struct net *net)
719 return net->ipv4.current_rt_cache_rebuild_count <=
720 net->ipv4.sysctl_rt_cache_rebuild_count;
723 static inline bool compare_hash_inputs(const struct flowi *fl1,
724 const struct flowi *fl2)
726 return ((((__force u32)fl1->fl4_dst ^ (__force u32)fl2->fl4_dst) |
727 ((__force u32)fl1->fl4_src ^ (__force u32)fl2->fl4_src) |
728 (fl1->iif ^ fl2->iif)) == 0);
731 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
733 return (((__force u32)fl1->fl4_dst ^ (__force u32)fl2->fl4_dst) |
734 ((__force u32)fl1->fl4_src ^ (__force u32)fl2->fl4_src) |
735 (fl1->mark ^ fl2->mark) |
736 (*(u16 *)&fl1->fl4_tos ^ *(u16 *)&fl2->fl4_tos) |
737 (fl1->oif ^ fl2->oif) |
738 (fl1->iif ^ fl2->iif)) == 0;
741 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
743 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
746 static inline int rt_is_expired(struct rtable *rth)
748 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
752 * Perform a full scan of hash table and free all entries.
753 * Can be called by a softirq or a process.
754 * In the later case, we want to be reschedule if necessary
756 static void rt_do_flush(struct net *net, int process_context)
759 struct rtable *rth, *next;
761 for (i = 0; i <= rt_hash_mask; i++) {
762 struct rtable __rcu **pprev;
765 if (process_context && need_resched())
767 rth = rcu_dereference_raw(rt_hash_table[i].chain);
771 spin_lock_bh(rt_hash_lock_addr(i));
774 pprev = &rt_hash_table[i].chain;
775 rth = rcu_dereference_protected(*pprev,
776 lockdep_is_held(rt_hash_lock_addr(i)));
779 next = rcu_dereference_protected(rth->dst.rt_next,
780 lockdep_is_held(rt_hash_lock_addr(i)));
783 net_eq(dev_net(rth->dst.dev), net)) {
784 rcu_assign_pointer(*pprev, next);
785 rcu_assign_pointer(rth->dst.rt_next, list);
788 pprev = &rth->dst.rt_next;
793 spin_unlock_bh(rt_hash_lock_addr(i));
795 for (; list; list = next) {
796 next = rcu_dereference_protected(list->dst.rt_next, 1);
803 * While freeing expired entries, we compute average chain length
804 * and standard deviation, using fixed-point arithmetic.
805 * This to have an estimation of rt_chain_length_max
806 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
807 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
811 #define ONE (1UL << FRACT_BITS)
814 * Given a hash chain and an item in this hash chain,
815 * find if a previous entry has the same hash_inputs
816 * (but differs on tos, mark or oif)
817 * Returns 0 if an alias is found.
818 * Returns ONE if rth has no alias before itself.
820 static int has_noalias(const struct rtable *head, const struct rtable *rth)
822 const struct rtable *aux = head;
825 if (compare_hash_inputs(&aux->fl, &rth->fl))
827 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
832 static void rt_check_expire(void)
834 static unsigned int rover;
835 unsigned int i = rover, goal;
837 struct rtable __rcu **rthp;
838 unsigned long samples = 0;
839 unsigned long sum = 0, sum2 = 0;
843 delta = jiffies - expires_ljiffies;
844 expires_ljiffies = jiffies;
845 mult = ((u64)delta) << rt_hash_log;
846 if (ip_rt_gc_timeout > 1)
847 do_div(mult, ip_rt_gc_timeout);
848 goal = (unsigned int)mult;
849 if (goal > rt_hash_mask)
850 goal = rt_hash_mask + 1;
851 for (; goal > 0; goal--) {
852 unsigned long tmo = ip_rt_gc_timeout;
853 unsigned long length;
855 i = (i + 1) & rt_hash_mask;
856 rthp = &rt_hash_table[i].chain;
863 if (rcu_dereference_raw(*rthp) == NULL)
866 spin_lock_bh(rt_hash_lock_addr(i));
867 while ((rth = rcu_dereference_protected(*rthp,
868 lockdep_is_held(rt_hash_lock_addr(i)))) != NULL) {
869 prefetch(rth->dst.rt_next);
870 if (rt_is_expired(rth)) {
871 *rthp = rth->dst.rt_next;
875 if (rth->dst.expires) {
876 /* Entry is expired even if it is in use */
877 if (time_before_eq(jiffies, rth->dst.expires)) {
880 rthp = &rth->dst.rt_next;
882 * We only count entries on
883 * a chain with equal hash inputs once
884 * so that entries for different QOS
885 * levels, and other non-hash input
886 * attributes don't unfairly skew
887 * the length computation
889 length += has_noalias(rt_hash_table[i].chain, rth);
892 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout))
895 /* Cleanup aged off entries. */
896 *rthp = rth->dst.rt_next;
899 spin_unlock_bh(rt_hash_lock_addr(i));
901 sum2 += length*length;
904 unsigned long avg = sum / samples;
905 unsigned long sd = int_sqrt(sum2 / samples - avg*avg);
906 rt_chain_length_max = max_t(unsigned long,
908 (avg + 4*sd) >> FRACT_BITS);
914 * rt_worker_func() is run in process context.
915 * we call rt_check_expire() to scan part of the hash table
917 static void rt_worker_func(struct work_struct *work)
920 schedule_delayed_work(&expires_work, ip_rt_gc_interval);
924 * Pertubation of rt_genid by a small quantity [1..256]
925 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
926 * many times (2^24) without giving recent rt_genid.
927 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
929 static void rt_cache_invalidate(struct net *net)
931 unsigned char shuffle;
933 get_random_bytes(&shuffle, sizeof(shuffle));
934 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
938 * delay < 0 : invalidate cache (fast : entries will be deleted later)
939 * delay >= 0 : invalidate & flush cache (can be long)
941 void rt_cache_flush(struct net *net, int delay)
943 rt_cache_invalidate(net);
945 rt_do_flush(net, !in_softirq());
948 /* Flush previous cache invalidated entries from the cache */
949 void rt_cache_flush_batch(struct net *net)
951 rt_do_flush(net, !in_softirq());
954 static void rt_emergency_hash_rebuild(struct net *net)
957 printk(KERN_WARNING "Route hash chain too long!\n");
958 rt_cache_invalidate(net);
962 Short description of GC goals.
964 We want to build algorithm, which will keep routing cache
965 at some equilibrium point, when number of aged off entries
966 is kept approximately equal to newly generated ones.
968 Current expiration strength is variable "expire".
969 We try to adjust it dynamically, so that if networking
970 is idle expires is large enough to keep enough of warm entries,
971 and when load increases it reduces to limit cache size.
974 static int rt_garbage_collect(struct dst_ops *ops)
976 static unsigned long expire = RT_GC_TIMEOUT;
977 static unsigned long last_gc;
979 static int equilibrium;
981 struct rtable __rcu **rthp;
982 unsigned long now = jiffies;
984 int entries = dst_entries_get_fast(&ipv4_dst_ops);
987 * Garbage collection is pretty expensive,
988 * do not make it too frequently.
991 RT_CACHE_STAT_INC(gc_total);
993 if (now - last_gc < ip_rt_gc_min_interval &&
994 entries < ip_rt_max_size) {
995 RT_CACHE_STAT_INC(gc_ignored);
999 entries = dst_entries_get_slow(&ipv4_dst_ops);
1000 /* Calculate number of entries, which we want to expire now. */
1001 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
1003 if (equilibrium < ipv4_dst_ops.gc_thresh)
1004 equilibrium = ipv4_dst_ops.gc_thresh;
1005 goal = entries - equilibrium;
1007 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
1008 goal = entries - equilibrium;
1011 /* We are in dangerous area. Try to reduce cache really
1014 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
1015 equilibrium = entries - goal;
1018 if (now - last_gc >= ip_rt_gc_min_interval)
1022 equilibrium += goal;
1029 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
1030 unsigned long tmo = expire;
1032 k = (k + 1) & rt_hash_mask;
1033 rthp = &rt_hash_table[k].chain;
1034 spin_lock_bh(rt_hash_lock_addr(k));
1035 while ((rth = rcu_dereference_protected(*rthp,
1036 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
1037 if (!rt_is_expired(rth) &&
1038 !rt_may_expire(rth, tmo, expire)) {
1040 rthp = &rth->dst.rt_next;
1043 *rthp = rth->dst.rt_next;
1047 spin_unlock_bh(rt_hash_lock_addr(k));
1056 /* Goal is not achieved. We stop process if:
1058 - if expire reduced to zero. Otherwise, expire is halfed.
1059 - if table is not full.
1060 - if we are called from interrupt.
1061 - jiffies check is just fallback/debug loop breaker.
1062 We will not spin here for long time in any case.
1065 RT_CACHE_STAT_INC(gc_goal_miss);
1071 #if RT_CACHE_DEBUG >= 2
1072 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
1073 dst_entries_get_fast(&ipv4_dst_ops), goal, i);
1076 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
1078 } while (!in_softirq() && time_before_eq(jiffies, now));
1080 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
1082 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
1084 if (net_ratelimit())
1085 printk(KERN_WARNING "dst cache overflow\n");
1086 RT_CACHE_STAT_INC(gc_dst_overflow);
1090 expire += ip_rt_gc_min_interval;
1091 if (expire > ip_rt_gc_timeout ||
1092 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
1093 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
1094 expire = ip_rt_gc_timeout;
1095 #if RT_CACHE_DEBUG >= 2
1096 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
1097 dst_entries_get_fast(&ipv4_dst_ops), goal, rover);
1103 * Returns number of entries in a hash chain that have different hash_inputs
1105 static int slow_chain_length(const struct rtable *head)
1108 const struct rtable *rth = head;
1111 length += has_noalias(head, rth);
1112 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1114 return length >> FRACT_BITS;
1117 static int rt_intern_hash(unsigned hash, struct rtable *rt,
1118 struct rtable **rp, struct sk_buff *skb, int ifindex)
1120 struct rtable *rth, *cand;
1121 struct rtable __rcu **rthp, **candp;
1125 int attempts = !in_softirq();
1129 min_score = ~(u32)0;
1134 if (!rt_caching(dev_net(rt->dst.dev))) {
1136 * If we're not caching, just tell the caller we
1137 * were successful and don't touch the route. The
1138 * caller hold the sole reference to the cache entry, and
1139 * it will be released when the caller is done with it.
1140 * If we drop it here, the callers have no way to resolve routes
1141 * when we're not caching. Instead, just point *rp at rt, so
1142 * the caller gets a single use out of the route
1143 * Note that we do rt_free on this new route entry, so that
1144 * once its refcount hits zero, we are still able to reap it
1146 * Note: To avoid expensive rcu stuff for this uncached dst,
1147 * we set DST_NOCACHE so that dst_release() can free dst without
1148 * waiting a grace period.
1151 rt->dst.flags |= DST_NOCACHE;
1152 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1153 int err = arp_bind_neighbour(&rt->dst);
1155 if (net_ratelimit())
1157 "Neighbour table failure & not caching routes.\n");
1166 rthp = &rt_hash_table[hash].chain;
1168 spin_lock_bh(rt_hash_lock_addr(hash));
1169 while ((rth = rcu_dereference_protected(*rthp,
1170 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1171 if (rt_is_expired(rth)) {
1172 *rthp = rth->dst.rt_next;
1176 if (compare_keys(&rth->fl, &rt->fl) && compare_netns(rth, rt)) {
1178 *rthp = rth->dst.rt_next;
1180 * Since lookup is lockfree, the deletion
1181 * must be visible to another weakly ordered CPU before
1182 * the insertion at the start of the hash chain.
1184 rcu_assign_pointer(rth->dst.rt_next,
1185 rt_hash_table[hash].chain);
1187 * Since lookup is lockfree, the update writes
1188 * must be ordered for consistency on SMP.
1190 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1192 dst_use(&rth->dst, now);
1193 spin_unlock_bh(rt_hash_lock_addr(hash));
1199 skb_dst_set(skb, &rth->dst);
1203 if (!atomic_read(&rth->dst.__refcnt)) {
1204 u32 score = rt_score(rth);
1206 if (score <= min_score) {
1215 rthp = &rth->dst.rt_next;
1219 /* ip_rt_gc_elasticity used to be average length of chain
1220 * length, when exceeded gc becomes really aggressive.
1222 * The second limit is less certain. At the moment it allows
1223 * only 2 entries per bucket. We will see.
1225 if (chain_length > ip_rt_gc_elasticity) {
1226 *candp = cand->dst.rt_next;
1230 if (chain_length > rt_chain_length_max &&
1231 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1232 struct net *net = dev_net(rt->dst.dev);
1233 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1234 if (!rt_caching(net)) {
1235 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1236 rt->dst.dev->name, num);
1238 rt_emergency_hash_rebuild(net);
1239 spin_unlock_bh(rt_hash_lock_addr(hash));
1241 hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1242 ifindex, rt_genid(net));
1247 /* Try to bind route to arp only if it is output
1248 route or unicast forwarding path.
1250 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1251 int err = arp_bind_neighbour(&rt->dst);
1253 spin_unlock_bh(rt_hash_lock_addr(hash));
1255 if (err != -ENOBUFS) {
1260 /* Neighbour tables are full and nothing
1261 can be released. Try to shrink route cache,
1262 it is most likely it holds some neighbour records.
1264 if (attempts-- > 0) {
1265 int saved_elasticity = ip_rt_gc_elasticity;
1266 int saved_int = ip_rt_gc_min_interval;
1267 ip_rt_gc_elasticity = 1;
1268 ip_rt_gc_min_interval = 0;
1269 rt_garbage_collect(&ipv4_dst_ops);
1270 ip_rt_gc_min_interval = saved_int;
1271 ip_rt_gc_elasticity = saved_elasticity;
1275 if (net_ratelimit())
1276 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1282 rt->dst.rt_next = rt_hash_table[hash].chain;
1284 #if RT_CACHE_DEBUG >= 2
1285 if (rt->dst.rt_next) {
1287 printk(KERN_DEBUG "rt_cache @%02x: %pI4",
1289 for (trt = rt->dst.rt_next; trt; trt = trt->dst.rt_next)
1290 printk(" . %pI4", &trt->rt_dst);
1295 * Since lookup is lockfree, we must make sure
1296 * previous writes to rt are comitted to memory
1297 * before making rt visible to other CPUS.
1299 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1301 spin_unlock_bh(rt_hash_lock_addr(hash));
1307 skb_dst_set(skb, &rt->dst);
1311 void rt_bind_peer(struct rtable *rt, int create)
1313 struct inet_peer *peer;
1315 peer = inet_getpeer_v4(rt->rt_dst, create);
1317 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1322 * Peer allocation may fail only in serious out-of-memory conditions. However
1323 * we still can generate some output.
1324 * Random ID selection looks a bit dangerous because we have no chances to
1325 * select ID being unique in a reasonable period of time.
1326 * But broken packet identifier may be better than no packet at all.
1328 static void ip_select_fb_ident(struct iphdr *iph)
1330 static DEFINE_SPINLOCK(ip_fb_id_lock);
1331 static u32 ip_fallback_id;
1334 spin_lock_bh(&ip_fb_id_lock);
1335 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1336 iph->id = htons(salt & 0xFFFF);
1337 ip_fallback_id = salt;
1338 spin_unlock_bh(&ip_fb_id_lock);
1341 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1343 struct rtable *rt = (struct rtable *) dst;
1346 if (rt->peer == NULL)
1347 rt_bind_peer(rt, 1);
1349 /* If peer is attached to destination, it is never detached,
1350 so that we need not to grab a lock to dereference it.
1353 iph->id = htons(inet_getid(rt->peer, more));
1357 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1358 __builtin_return_address(0));
1360 ip_select_fb_ident(iph);
1362 EXPORT_SYMBOL(__ip_select_ident);
1364 static void rt_del(unsigned hash, struct rtable *rt)
1366 struct rtable __rcu **rthp;
1369 rthp = &rt_hash_table[hash].chain;
1370 spin_lock_bh(rt_hash_lock_addr(hash));
1372 while ((aux = rcu_dereference_protected(*rthp,
1373 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1374 if (aux == rt || rt_is_expired(aux)) {
1375 *rthp = aux->dst.rt_next;
1379 rthp = &aux->dst.rt_next;
1381 spin_unlock_bh(rt_hash_lock_addr(hash));
1384 /* called in rcu_read_lock() section */
1385 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1386 __be32 saddr, struct net_device *dev)
1389 struct in_device *in_dev = __in_dev_get_rcu(dev);
1391 struct rtable __rcu **rthp;
1392 __be32 skeys[2] = { saddr, 0 };
1393 int ikeys[2] = { dev->ifindex, 0 };
1394 struct netevent_redirect netevent;
1401 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1402 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1403 ipv4_is_zeronet(new_gw))
1404 goto reject_redirect;
1406 if (!rt_caching(net))
1407 goto reject_redirect;
1409 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1410 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1411 goto reject_redirect;
1412 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1413 goto reject_redirect;
1415 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1416 goto reject_redirect;
1419 for (i = 0; i < 2; i++) {
1420 for (k = 0; k < 2; k++) {
1421 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1424 rthp = &rt_hash_table[hash].chain;
1426 while ((rth = rcu_dereference(*rthp)) != NULL) {
1429 if (rth->fl.fl4_dst != daddr ||
1430 rth->fl.fl4_src != skeys[i] ||
1431 rth->fl.oif != ikeys[k] ||
1432 rt_is_input_route(rth) ||
1433 rt_is_expired(rth) ||
1434 !net_eq(dev_net(rth->dst.dev), net)) {
1435 rthp = &rth->dst.rt_next;
1439 if (rth->rt_dst != daddr ||
1440 rth->rt_src != saddr ||
1442 rth->rt_gateway != old_gw ||
1443 rth->dst.dev != dev)
1446 dst_hold(&rth->dst);
1448 rt = dst_alloc(&ipv4_dst_ops);
1454 /* Copy all the information. */
1457 atomic_set(&rt->dst.__refcnt, 1);
1458 rt->dst.child = NULL;
1460 dev_hold(rt->dst.dev);
1461 rt->dst.obsolete = -1;
1462 rt->dst.lastuse = jiffies;
1463 rt->dst.path = &rt->dst;
1464 rt->dst.neighbour = NULL;
1467 rt->dst.xfrm = NULL;
1469 rt->rt_genid = rt_genid(net);
1470 rt->rt_flags |= RTCF_REDIRECTED;
1472 /* Gateway is different ... */
1473 rt->rt_gateway = new_gw;
1475 /* Redirect received -> path was valid */
1476 dst_confirm(&rth->dst);
1479 atomic_inc(&rt->peer->refcnt);
1481 atomic_inc(&rt->fi->fib_clntref);
1483 if (arp_bind_neighbour(&rt->dst) ||
1484 !(rt->dst.neighbour->nud_state &
1486 if (rt->dst.neighbour)
1487 neigh_event_send(rt->dst.neighbour, NULL);
1493 netevent.old = &rth->dst;
1494 netevent.new = &rt->dst;
1495 call_netevent_notifiers(NETEVENT_REDIRECT,
1499 if (!rt_intern_hash(hash, rt, &rt, NULL, rt->fl.oif))
1510 #ifdef CONFIG_IP_ROUTE_VERBOSE
1511 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1512 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1513 " Advised path = %pI4 -> %pI4\n",
1514 &old_gw, dev->name, &new_gw,
1520 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1522 struct rtable *rt = (struct rtable *)dst;
1523 struct dst_entry *ret = dst;
1526 if (dst->obsolete > 0) {
1529 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
1531 time_after_eq(jiffies, rt->dst.expires))) {
1532 unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1534 rt_genid(dev_net(dst->dev)));
1535 #if RT_CACHE_DEBUG >= 1
1536 printk(KERN_DEBUG "ipv4_negative_advice: redirect to %pI4/%02x dropped\n",
1537 &rt->rt_dst, rt->fl.fl4_tos);
1548 * 1. The first ip_rt_redirect_number redirects are sent
1549 * with exponential backoff, then we stop sending them at all,
1550 * assuming that the host ignores our redirects.
1551 * 2. If we did not see packets requiring redirects
1552 * during ip_rt_redirect_silence, we assume that the host
1553 * forgot redirected route and start to send redirects again.
1555 * This algorithm is much cheaper and more intelligent than dumb load limiting
1558 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1559 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1562 void ip_rt_send_redirect(struct sk_buff *skb)
1564 struct rtable *rt = skb_rtable(skb);
1565 struct in_device *in_dev;
1569 in_dev = __in_dev_get_rcu(rt->dst.dev);
1570 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1574 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1577 /* No redirected packets during ip_rt_redirect_silence;
1578 * reset the algorithm.
1580 if (time_after(jiffies, rt->dst.rate_last + ip_rt_redirect_silence))
1581 rt->dst.rate_tokens = 0;
1583 /* Too many ignored redirects; do not send anything
1584 * set dst.rate_last to the last seen redirected packet.
1586 if (rt->dst.rate_tokens >= ip_rt_redirect_number) {
1587 rt->dst.rate_last = jiffies;
1591 /* Check for load limit; set rate_last to the latest sent
1594 if (rt->dst.rate_tokens == 0 ||
1596 (rt->dst.rate_last +
1597 (ip_rt_redirect_load << rt->dst.rate_tokens)))) {
1598 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1599 rt->dst.rate_last = jiffies;
1600 ++rt->dst.rate_tokens;
1601 #ifdef CONFIG_IP_ROUTE_VERBOSE
1603 rt->dst.rate_tokens == ip_rt_redirect_number &&
1605 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1606 &rt->rt_src, rt->rt_iif,
1607 &rt->rt_dst, &rt->rt_gateway);
1612 static int ip_error(struct sk_buff *skb)
1614 struct rtable *rt = skb_rtable(skb);
1618 switch (rt->dst.error) {
1623 code = ICMP_HOST_UNREACH;
1626 code = ICMP_NET_UNREACH;
1627 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1628 IPSTATS_MIB_INNOROUTES);
1631 code = ICMP_PKT_FILTERED;
1636 rt->dst.rate_tokens += now - rt->dst.rate_last;
1637 if (rt->dst.rate_tokens > ip_rt_error_burst)
1638 rt->dst.rate_tokens = ip_rt_error_burst;
1639 rt->dst.rate_last = now;
1640 if (rt->dst.rate_tokens >= ip_rt_error_cost) {
1641 rt->dst.rate_tokens -= ip_rt_error_cost;
1642 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1645 out: kfree_skb(skb);
1650 * The last two values are not from the RFC but
1651 * are needed for AMPRnet AX.25 paths.
1654 static const unsigned short mtu_plateau[] =
1655 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1657 static inline unsigned short guess_mtu(unsigned short old_mtu)
1661 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1662 if (old_mtu > mtu_plateau[i])
1663 return mtu_plateau[i];
1667 unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
1668 unsigned short new_mtu,
1669 struct net_device *dev)
1672 unsigned short old_mtu = ntohs(iph->tot_len);
1674 int ikeys[2] = { dev->ifindex, 0 };
1675 __be32 skeys[2] = { iph->saddr, 0, };
1676 __be32 daddr = iph->daddr;
1677 unsigned short est_mtu = 0;
1679 for (k = 0; k < 2; k++) {
1680 for (i = 0; i < 2; i++) {
1681 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1685 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1686 rth = rcu_dereference(rth->dst.rt_next)) {
1687 unsigned short mtu = new_mtu;
1689 if (rth->fl.fl4_dst != daddr ||
1690 rth->fl.fl4_src != skeys[i] ||
1691 rth->rt_dst != daddr ||
1692 rth->rt_src != iph->saddr ||
1693 rth->fl.oif != ikeys[k] ||
1694 rt_is_input_route(rth) ||
1695 dst_metric_locked(&rth->dst, RTAX_MTU) ||
1696 !net_eq(dev_net(rth->dst.dev), net) ||
1700 if (new_mtu < 68 || new_mtu >= old_mtu) {
1702 /* BSD 4.2 compatibility hack :-( */
1704 old_mtu >= dst_mtu(&rth->dst) &&
1705 old_mtu >= 68 + (iph->ihl << 2))
1706 old_mtu -= iph->ihl << 2;
1708 mtu = guess_mtu(old_mtu);
1710 if (mtu <= dst_mtu(&rth->dst)) {
1711 if (mtu < dst_mtu(&rth->dst)) {
1712 dst_confirm(&rth->dst);
1713 if (mtu < ip_rt_min_pmtu) {
1714 u32 lock = dst_metric(&rth->dst,
1716 mtu = ip_rt_min_pmtu;
1717 lock |= (1 << RTAX_MTU);
1718 dst_metric_set(&rth->dst, RTAX_LOCK,
1721 dst_metric_set(&rth->dst, RTAX_MTU, mtu);
1722 dst_set_expires(&rth->dst,
1731 return est_mtu ? : new_mtu;
1734 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1736 if (dst_mtu(dst) > mtu && mtu >= 68 &&
1737 !(dst_metric_locked(dst, RTAX_MTU))) {
1738 if (mtu < ip_rt_min_pmtu) {
1739 u32 lock = dst_metric(dst, RTAX_LOCK);
1740 mtu = ip_rt_min_pmtu;
1741 dst_metric_set(dst, RTAX_LOCK, lock | (1 << RTAX_MTU));
1743 dst_metric_set(dst, RTAX_MTU, mtu);
1744 dst_set_expires(dst, ip_rt_mtu_expires);
1745 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
1749 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1751 if (rt_is_expired((struct rtable *)dst))
1756 static void ipv4_dst_destroy(struct dst_entry *dst)
1758 struct rtable *rt = (struct rtable *) dst;
1759 struct inet_peer *peer = rt->peer;
1762 fib_info_put(rt->fi);
1772 static void ipv4_link_failure(struct sk_buff *skb)
1776 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1778 rt = skb_rtable(skb);
1780 dst_set_expires(&rt->dst, 0);
1783 static int ip_rt_bug(struct sk_buff *skb)
1785 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1786 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1787 skb->dev ? skb->dev->name : "?");
1793 We do not cache source address of outgoing interface,
1794 because it is used only by IP RR, TS and SRR options,
1795 so that it out of fast path.
1797 BTW remember: "addr" is allowed to be not aligned
1801 void ip_rt_get_source(u8 *addr, struct rtable *rt)
1804 struct fib_result res;
1806 if (rt_is_output_route(rt))
1810 if (fib_lookup(dev_net(rt->dst.dev), &rt->fl, &res) == 0)
1811 src = FIB_RES_PREFSRC(res);
1813 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1817 memcpy(addr, &src, 4);
1820 #ifdef CONFIG_IP_ROUTE_CLASSID
1821 static void set_class_tag(struct rtable *rt, u32 tag)
1823 if (!(rt->dst.tclassid & 0xFFFF))
1824 rt->dst.tclassid |= tag & 0xFFFF;
1825 if (!(rt->dst.tclassid & 0xFFFF0000))
1826 rt->dst.tclassid |= tag & 0xFFFF0000;
1830 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1832 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1835 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1837 if (advmss > 65535 - 40)
1838 advmss = 65535 - 40;
1843 static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
1845 unsigned int mtu = dst->dev->mtu;
1847 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1848 const struct rtable *rt = (const struct rtable *) dst;
1850 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1854 if (mtu > IP_MAX_MTU)
1860 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
1862 struct dst_entry *dst = &rt->dst;
1863 struct fib_info *fi = res->fi;
1866 if (FIB_RES_GW(*res) &&
1867 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1868 rt->rt_gateway = FIB_RES_GW(*res);
1870 atomic_inc(&fi->fib_clntref);
1871 dst_init_metrics(dst, fi->fib_metrics, true);
1872 #ifdef CONFIG_IP_ROUTE_CLASSID
1873 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1877 if (dst_mtu(dst) > IP_MAX_MTU)
1878 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1879 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1880 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1882 #ifdef CONFIG_IP_ROUTE_CLASSID
1883 #ifdef CONFIG_IP_MULTIPLE_TABLES
1884 set_class_tag(rt, fib_rules_tclass(res));
1886 set_class_tag(rt, itag);
1888 rt->rt_type = res->type;
1891 /* called in rcu_read_lock() section */
1892 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1893 u8 tos, struct net_device *dev, int our)
1898 struct in_device *in_dev = __in_dev_get_rcu(dev);
1902 /* Primary sanity checks. */
1907 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1908 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1911 if (ipv4_is_zeronet(saddr)) {
1912 if (!ipv4_is_local_multicast(daddr))
1914 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1916 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
1921 rth = dst_alloc(&ipv4_dst_ops);
1925 rth->dst.output = ip_rt_bug;
1926 rth->dst.obsolete = -1;
1928 atomic_set(&rth->dst.__refcnt, 1);
1929 rth->dst.flags= DST_HOST;
1930 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1931 rth->dst.flags |= DST_NOPOLICY;
1932 rth->fl.fl4_dst = daddr;
1933 rth->rt_dst = daddr;
1934 rth->fl.fl4_tos = tos;
1935 rth->fl.mark = skb->mark;
1936 rth->fl.fl4_src = saddr;
1937 rth->rt_src = saddr;
1938 #ifdef CONFIG_IP_ROUTE_CLASSID
1939 rth->dst.tclassid = itag;
1942 rth->fl.iif = dev->ifindex;
1943 rth->dst.dev = init_net.loopback_dev;
1944 dev_hold(rth->dst.dev);
1946 rth->rt_gateway = daddr;
1947 rth->rt_spec_dst= spec_dst;
1948 rth->rt_genid = rt_genid(dev_net(dev));
1949 rth->rt_flags = RTCF_MULTICAST;
1950 rth->rt_type = RTN_MULTICAST;
1952 rth->dst.input= ip_local_deliver;
1953 rth->rt_flags |= RTCF_LOCAL;
1956 #ifdef CONFIG_IP_MROUTE
1957 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1958 rth->dst.input = ip_mr_input;
1960 RT_CACHE_STAT_INC(in_slow_mc);
1962 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1963 return rt_intern_hash(hash, rth, NULL, skb, dev->ifindex);
1974 static void ip_handle_martian_source(struct net_device *dev,
1975 struct in_device *in_dev,
1976 struct sk_buff *skb,
1980 RT_CACHE_STAT_INC(in_martian_src);
1981 #ifdef CONFIG_IP_ROUTE_VERBOSE
1982 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1984 * RFC1812 recommendation, if source is martian,
1985 * the only hint is MAC header.
1987 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1988 &daddr, &saddr, dev->name);
1989 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1991 const unsigned char *p = skb_mac_header(skb);
1992 printk(KERN_WARNING "ll header: ");
1993 for (i = 0; i < dev->hard_header_len; i++, p++) {
1995 if (i < (dev->hard_header_len - 1))
2004 /* called in rcu_read_lock() section */
2005 static int __mkroute_input(struct sk_buff *skb,
2006 struct fib_result *res,
2007 struct in_device *in_dev,
2008 __be32 daddr, __be32 saddr, u32 tos,
2009 struct rtable **result)
2013 struct in_device *out_dev;
2014 unsigned int flags = 0;
2018 /* get a working reference to the output device */
2019 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
2020 if (out_dev == NULL) {
2021 if (net_ratelimit())
2022 printk(KERN_CRIT "Bug in ip_route_input" \
2023 "_slow(). Please, report\n");
2028 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
2029 in_dev->dev, &spec_dst, &itag, skb->mark);
2031 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2038 flags |= RTCF_DIRECTSRC;
2040 if (out_dev == in_dev && err &&
2041 (IN_DEV_SHARED_MEDIA(out_dev) ||
2042 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2043 flags |= RTCF_DOREDIRECT;
2045 if (skb->protocol != htons(ETH_P_IP)) {
2046 /* Not IP (i.e. ARP). Do not create route, if it is
2047 * invalid for proxy arp. DNAT routes are always valid.
2049 * Proxy arp feature have been extended to allow, ARP
2050 * replies back to the same interface, to support
2051 * Private VLAN switch technologies. See arp.c.
2053 if (out_dev == in_dev &&
2054 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2061 rth = dst_alloc(&ipv4_dst_ops);
2067 atomic_set(&rth->dst.__refcnt, 1);
2068 rth->dst.flags= DST_HOST;
2069 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2070 rth->dst.flags |= DST_NOPOLICY;
2071 if (IN_DEV_CONF_GET(out_dev, NOXFRM))
2072 rth->dst.flags |= DST_NOXFRM;
2073 rth->fl.fl4_dst = daddr;
2074 rth->rt_dst = daddr;
2075 rth->fl.fl4_tos = tos;
2076 rth->fl.mark = skb->mark;
2077 rth->fl.fl4_src = saddr;
2078 rth->rt_src = saddr;
2079 rth->rt_gateway = daddr;
2081 rth->fl.iif = in_dev->dev->ifindex;
2082 rth->dst.dev = (out_dev)->dev;
2083 dev_hold(rth->dst.dev);
2085 rth->rt_spec_dst= spec_dst;
2087 rth->dst.obsolete = -1;
2088 rth->dst.input = ip_forward;
2089 rth->dst.output = ip_output;
2090 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2092 rt_set_nexthop(rth, res, itag);
2094 rth->rt_flags = flags;
2102 static int ip_mkroute_input(struct sk_buff *skb,
2103 struct fib_result *res,
2104 const struct flowi *fl,
2105 struct in_device *in_dev,
2106 __be32 daddr, __be32 saddr, u32 tos)
2108 struct rtable* rth = NULL;
2112 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2113 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
2114 fib_select_multipath(fl, res);
2117 /* create a routing cache entry */
2118 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2122 /* put it into the cache */
2123 hash = rt_hash(daddr, saddr, fl->iif,
2124 rt_genid(dev_net(rth->dst.dev)));
2125 return rt_intern_hash(hash, rth, NULL, skb, fl->iif);
2129 * NOTE. We drop all the packets that has local source
2130 * addresses, because every properly looped back packet
2131 * must have correct destination already attached by output routine.
2133 * Such approach solves two big problems:
2134 * 1. Not simplex devices are handled properly.
2135 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2136 * called with rcu_read_lock()
2139 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2140 u8 tos, struct net_device *dev)
2142 struct fib_result res;
2143 struct in_device *in_dev = __in_dev_get_rcu(dev);
2144 struct flowi fl = { .fl4_dst = daddr,
2147 .fl4_scope = RT_SCOPE_UNIVERSE,
2149 .iif = dev->ifindex };
2152 struct rtable * rth;
2156 struct net * net = dev_net(dev);
2158 /* IP on this device is disabled. */
2163 /* Check for the most weird martians, which can be not detected
2167 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2168 ipv4_is_loopback(saddr))
2169 goto martian_source;
2171 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2174 /* Accept zero addresses only to limited broadcast;
2175 * I even do not know to fix it or not. Waiting for complains :-)
2177 if (ipv4_is_zeronet(saddr))
2178 goto martian_source;
2180 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2181 goto martian_destination;
2184 * Now we are ready to route packet.
2186 err = fib_lookup(net, &fl, &res);
2188 if (!IN_DEV_FORWARD(in_dev))
2193 RT_CACHE_STAT_INC(in_slow_tot);
2195 if (res.type == RTN_BROADCAST)
2198 if (res.type == RTN_LOCAL) {
2199 err = fib_validate_source(saddr, daddr, tos,
2200 net->loopback_dev->ifindex,
2201 dev, &spec_dst, &itag, skb->mark);
2203 goto martian_source_keep_err;
2205 flags |= RTCF_DIRECTSRC;
2210 if (!IN_DEV_FORWARD(in_dev))
2212 if (res.type != RTN_UNICAST)
2213 goto martian_destination;
2215 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
2219 if (skb->protocol != htons(ETH_P_IP))
2222 if (ipv4_is_zeronet(saddr))
2223 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2225 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
2228 goto martian_source_keep_err;
2230 flags |= RTCF_DIRECTSRC;
2232 flags |= RTCF_BROADCAST;
2233 res.type = RTN_BROADCAST;
2234 RT_CACHE_STAT_INC(in_brd);
2237 rth = dst_alloc(&ipv4_dst_ops);
2241 rth->dst.output= ip_rt_bug;
2242 rth->dst.obsolete = -1;
2243 rth->rt_genid = rt_genid(net);
2245 atomic_set(&rth->dst.__refcnt, 1);
2246 rth->dst.flags= DST_HOST;
2247 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2248 rth->dst.flags |= DST_NOPOLICY;
2249 rth->fl.fl4_dst = daddr;
2250 rth->rt_dst = daddr;
2251 rth->fl.fl4_tos = tos;
2252 rth->fl.mark = skb->mark;
2253 rth->fl.fl4_src = saddr;
2254 rth->rt_src = saddr;
2255 #ifdef CONFIG_IP_ROUTE_CLASSID
2256 rth->dst.tclassid = itag;
2259 rth->fl.iif = dev->ifindex;
2260 rth->dst.dev = net->loopback_dev;
2261 dev_hold(rth->dst.dev);
2262 rth->rt_gateway = daddr;
2263 rth->rt_spec_dst= spec_dst;
2264 rth->dst.input= ip_local_deliver;
2265 rth->rt_flags = flags|RTCF_LOCAL;
2266 if (res.type == RTN_UNREACHABLE) {
2267 rth->dst.input= ip_error;
2268 rth->dst.error= -err;
2269 rth->rt_flags &= ~RTCF_LOCAL;
2271 rth->rt_type = res.type;
2272 hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
2273 err = rt_intern_hash(hash, rth, NULL, skb, fl.iif);
2277 RT_CACHE_STAT_INC(in_no_route);
2278 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2279 res.type = RTN_UNREACHABLE;
2285 * Do not cache martian addresses: they should be logged (RFC1812)
2287 martian_destination:
2288 RT_CACHE_STAT_INC(in_martian_dst);
2289 #ifdef CONFIG_IP_ROUTE_VERBOSE
2290 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2291 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2292 &daddr, &saddr, dev->name);
2296 err = -EHOSTUNREACH;
2309 martian_source_keep_err:
2310 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2314 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2315 u8 tos, struct net_device *dev, bool noref)
2317 struct rtable * rth;
2319 int iif = dev->ifindex;
2327 if (!rt_caching(net))
2330 tos &= IPTOS_RT_MASK;
2331 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2333 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2334 rth = rcu_dereference(rth->dst.rt_next)) {
2335 if ((((__force u32)rth->fl.fl4_dst ^ (__force u32)daddr) |
2336 ((__force u32)rth->fl.fl4_src ^ (__force u32)saddr) |
2337 (rth->fl.iif ^ iif) |
2339 (rth->fl.fl4_tos ^ tos)) == 0 &&
2340 rth->fl.mark == skb->mark &&
2341 net_eq(dev_net(rth->dst.dev), net) &&
2342 !rt_is_expired(rth)) {
2344 dst_use_noref(&rth->dst, jiffies);
2345 skb_dst_set_noref(skb, &rth->dst);
2347 dst_use(&rth->dst, jiffies);
2348 skb_dst_set(skb, &rth->dst);
2350 RT_CACHE_STAT_INC(in_hit);
2354 RT_CACHE_STAT_INC(in_hlist_search);
2358 /* Multicast recognition logic is moved from route cache to here.
2359 The problem was that too many Ethernet cards have broken/missing
2360 hardware multicast filters :-( As result the host on multicasting
2361 network acquires a lot of useless route cache entries, sort of
2362 SDR messages from all the world. Now we try to get rid of them.
2363 Really, provided software IP multicast filter is organized
2364 reasonably (at least, hashed), it does not result in a slowdown
2365 comparing with route cache reject entries.
2366 Note, that multicast routers are not affected, because
2367 route cache entry is created eventually.
2369 if (ipv4_is_multicast(daddr)) {
2370 struct in_device *in_dev = __in_dev_get_rcu(dev);
2373 int our = ip_check_mc(in_dev, daddr, saddr,
2374 ip_hdr(skb)->protocol);
2376 #ifdef CONFIG_IP_MROUTE
2378 (!ipv4_is_local_multicast(daddr) &&
2379 IN_DEV_MFORWARD(in_dev))
2382 int res = ip_route_input_mc(skb, daddr, saddr,
2391 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2395 EXPORT_SYMBOL(ip_route_input_common);
2397 /* called with rcu_read_lock() */
2398 static int __mkroute_output(struct rtable **result,
2399 struct fib_result *res,
2400 const struct flowi *fl,
2401 const struct flowi *oldflp,
2402 struct net_device *dev_out,
2406 struct in_device *in_dev;
2407 u32 tos = RT_FL_TOS(oldflp);
2409 if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags & IFF_LOOPBACK))
2412 if (ipv4_is_lbcast(fl->fl4_dst))
2413 res->type = RTN_BROADCAST;
2414 else if (ipv4_is_multicast(fl->fl4_dst))
2415 res->type = RTN_MULTICAST;
2416 else if (ipv4_is_zeronet(fl->fl4_dst))
2419 if (dev_out->flags & IFF_LOOPBACK)
2420 flags |= RTCF_LOCAL;
2422 in_dev = __in_dev_get_rcu(dev_out);
2426 if (res->type == RTN_BROADCAST) {
2427 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2429 } else if (res->type == RTN_MULTICAST) {
2430 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2431 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2433 flags &= ~RTCF_LOCAL;
2434 /* If multicast route do not exist use
2435 * default one, but do not gateway in this case.
2438 if (res->fi && res->prefixlen < 4)
2443 rth = dst_alloc(&ipv4_dst_ops);
2447 atomic_set(&rth->dst.__refcnt, 1);
2448 rth->dst.flags= DST_HOST;
2449 if (IN_DEV_CONF_GET(in_dev, NOXFRM))
2450 rth->dst.flags |= DST_NOXFRM;
2451 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2452 rth->dst.flags |= DST_NOPOLICY;
2454 rth->fl.fl4_dst = oldflp->fl4_dst;
2455 rth->fl.fl4_tos = tos;
2456 rth->fl.fl4_src = oldflp->fl4_src;
2457 rth->fl.oif = oldflp->oif;
2458 rth->fl.mark = oldflp->mark;
2459 rth->rt_dst = fl->fl4_dst;
2460 rth->rt_src = fl->fl4_src;
2461 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2462 /* get references to the devices that are to be hold by the routing
2464 rth->dst.dev = dev_out;
2466 rth->rt_gateway = fl->fl4_dst;
2467 rth->rt_spec_dst= fl->fl4_src;
2469 rth->dst.output=ip_output;
2470 rth->dst.obsolete = -1;
2471 rth->rt_genid = rt_genid(dev_net(dev_out));
2473 RT_CACHE_STAT_INC(out_slow_tot);
2475 if (flags & RTCF_LOCAL) {
2476 rth->dst.input = ip_local_deliver;
2477 rth->rt_spec_dst = fl->fl4_dst;
2479 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2480 rth->rt_spec_dst = fl->fl4_src;
2481 if (flags & RTCF_LOCAL &&
2482 !(dev_out->flags & IFF_LOOPBACK)) {
2483 rth->dst.output = ip_mc_output;
2484 RT_CACHE_STAT_INC(out_slow_mc);
2486 #ifdef CONFIG_IP_MROUTE
2487 if (res->type == RTN_MULTICAST) {
2488 if (IN_DEV_MFORWARD(in_dev) &&
2489 !ipv4_is_local_multicast(oldflp->fl4_dst)) {
2490 rth->dst.input = ip_mr_input;
2491 rth->dst.output = ip_mc_output;
2497 rt_set_nexthop(rth, res, 0);
2499 rth->rt_flags = flags;
2504 /* called with rcu_read_lock() */
2505 static int ip_mkroute_output(struct rtable **rp,
2506 struct fib_result *res,
2507 const struct flowi *fl,
2508 const struct flowi *oldflp,
2509 struct net_device *dev_out,
2512 struct rtable *rth = NULL;
2513 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
2516 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
2517 rt_genid(dev_net(dev_out)));
2518 err = rt_intern_hash(hash, rth, rp, NULL, oldflp->oif);
2525 * Major route resolver routine.
2526 * called with rcu_read_lock();
2529 static int ip_route_output_slow(struct net *net, struct rtable **rp,
2530 const struct flowi *oldflp)
2532 u32 tos = RT_FL_TOS(oldflp);
2533 struct flowi fl = { .fl4_dst = oldflp->fl4_dst,
2534 .fl4_src = oldflp->fl4_src,
2535 .fl4_tos = tos & IPTOS_RT_MASK,
2536 .fl4_scope = ((tos & RTO_ONLINK) ?
2537 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE),
2538 .mark = oldflp->mark,
2539 .iif = net->loopback_dev->ifindex,
2540 .oif = oldflp->oif };
2541 struct fib_result res;
2542 unsigned int flags = 0;
2543 struct net_device *dev_out = NULL;
2548 #ifdef CONFIG_IP_MULTIPLE_TABLES
2552 if (oldflp->fl4_src) {
2554 if (ipv4_is_multicast(oldflp->fl4_src) ||
2555 ipv4_is_lbcast(oldflp->fl4_src) ||
2556 ipv4_is_zeronet(oldflp->fl4_src))
2559 /* I removed check for oif == dev_out->oif here.
2560 It was wrong for two reasons:
2561 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2562 is assigned to multiple interfaces.
2563 2. Moreover, we are allowed to send packets with saddr
2564 of another iface. --ANK
2567 if (oldflp->oif == 0 &&
2568 (ipv4_is_multicast(oldflp->fl4_dst) ||
2569 ipv4_is_lbcast(oldflp->fl4_dst))) {
2570 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2571 dev_out = __ip_dev_find(net, oldflp->fl4_src, false);
2572 if (dev_out == NULL)
2575 /* Special hack: user can direct multicasts
2576 and limited broadcast via necessary interface
2577 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2578 This hack is not just for fun, it allows
2579 vic,vat and friends to work.
2580 They bind socket to loopback, set ttl to zero
2581 and expect that it will work.
2582 From the viewpoint of routing cache they are broken,
2583 because we are not allowed to build multicast path
2584 with loopback source addr (look, routing cache
2585 cannot know, that ttl is zero, so that packet
2586 will not leave this host and route is valid).
2587 Luckily, this hack is good workaround.
2590 fl.oif = dev_out->ifindex;
2594 if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
2595 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2596 if (!__ip_dev_find(net, oldflp->fl4_src, false))
2603 dev_out = dev_get_by_index_rcu(net, oldflp->oif);
2605 if (dev_out == NULL)
2608 /* RACE: Check return value of inet_select_addr instead. */
2609 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2613 if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
2614 ipv4_is_lbcast(oldflp->fl4_dst)) {
2616 fl.fl4_src = inet_select_addr(dev_out, 0,
2621 if (ipv4_is_multicast(oldflp->fl4_dst))
2622 fl.fl4_src = inet_select_addr(dev_out, 0,
2624 else if (!oldflp->fl4_dst)
2625 fl.fl4_src = inet_select_addr(dev_out, 0,
2631 fl.fl4_dst = fl.fl4_src;
2633 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2634 dev_out = net->loopback_dev;
2635 fl.oif = net->loopback_dev->ifindex;
2636 res.type = RTN_LOCAL;
2637 flags |= RTCF_LOCAL;
2641 if (fib_lookup(net, &fl, &res)) {
2644 /* Apparently, routing tables are wrong. Assume,
2645 that the destination is on link.
2648 Because we are allowed to send to iface
2649 even if it has NO routes and NO assigned
2650 addresses. When oif is specified, routing
2651 tables are looked up with only one purpose:
2652 to catch if destination is gatewayed, rather than
2653 direct. Moreover, if MSG_DONTROUTE is set,
2654 we send packet, ignoring both routing tables
2655 and ifaddr state. --ANK
2658 We could make it even if oif is unknown,
2659 likely IPv6, but we do not.
2662 if (fl.fl4_src == 0)
2663 fl.fl4_src = inet_select_addr(dev_out, 0,
2665 res.type = RTN_UNICAST;
2672 if (res.type == RTN_LOCAL) {
2674 if (res.fi->fib_prefsrc)
2675 fl.fl4_src = res.fi->fib_prefsrc;
2677 fl.fl4_src = fl.fl4_dst;
2679 dev_out = net->loopback_dev;
2680 fl.oif = dev_out->ifindex;
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);
2697 dev_out = FIB_RES_DEV(res);
2698 fl.oif = dev_out->ifindex;
2702 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
2707 int __ip_route_output_key(struct net *net, struct rtable **rp,
2708 const struct flowi *flp)
2714 if (!rt_caching(net))
2717 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net));
2720 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2721 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2722 if (rth->fl.fl4_dst == flp->fl4_dst &&
2723 rth->fl.fl4_src == flp->fl4_src &&
2724 rt_is_output_route(rth) &&
2725 rth->fl.oif == flp->oif &&
2726 rth->fl.mark == flp->mark &&
2727 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2728 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2729 net_eq(dev_net(rth->dst.dev), net) &&
2730 !rt_is_expired(rth)) {
2731 dst_use(&rth->dst, jiffies);
2732 RT_CACHE_STAT_INC(out_hit);
2733 rcu_read_unlock_bh();
2737 RT_CACHE_STAT_INC(out_hlist_search);
2739 rcu_read_unlock_bh();
2743 res = ip_route_output_slow(net, rp, flp);
2747 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2749 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
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_blackhole_dst_check,
2763 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2767 static int ipv4_dst_blackhole(struct net *net, struct rtable **rp, struct flowi *flp)
2769 struct rtable *ort = *rp;
2770 struct rtable *rt = (struct rtable *)
2771 dst_alloc(&ipv4_dst_blackhole_ops);
2774 struct dst_entry *new = &rt->dst;
2776 atomic_set(&new->__refcnt, 1);
2778 new->input = dst_discard;
2779 new->output = dst_discard;
2780 dst_copy_metrics(new, &ort->dst);
2782 new->dev = ort->dst.dev;
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);
2801 atomic_inc(&rt->fi->fib_clntref);
2806 dst_release(&(*rp)->dst);
2808 return rt ? 0 : -ENOMEM;
2811 int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
2812 struct sock *sk, int flags)
2816 if ((err = __ip_route_output_key(net, rp, flp)) != 0)
2821 flp->fl4_src = (*rp)->rt_src;
2823 flp->fl4_dst = (*rp)->rt_dst;
2824 err = __xfrm_lookup(net, (struct dst_entry **)rp, flp, sk,
2825 flags ? XFRM_LOOKUP_WAIT : 0);
2826 if (err == -EREMOTE)
2827 err = ipv4_dst_blackhole(net, rp, flp);
2834 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2836 int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp)
2838 return ip_route_output_flow(net, rp, flp, NULL, 0);
2840 EXPORT_SYMBOL(ip_route_output_key);
2842 static int rt_fill_info(struct net *net,
2843 struct sk_buff *skb, u32 pid, u32 seq, int event,
2844 int nowait, unsigned int flags)
2846 struct rtable *rt = skb_rtable(skb);
2848 struct nlmsghdr *nlh;
2850 u32 id = 0, ts = 0, tsage = 0, error;
2852 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2856 r = nlmsg_data(nlh);
2857 r->rtm_family = AF_INET;
2858 r->rtm_dst_len = 32;
2860 r->rtm_tos = rt->fl.fl4_tos;
2861 r->rtm_table = RT_TABLE_MAIN;
2862 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2863 r->rtm_type = rt->rt_type;
2864 r->rtm_scope = RT_SCOPE_UNIVERSE;
2865 r->rtm_protocol = RTPROT_UNSPEC;
2866 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2867 if (rt->rt_flags & RTCF_NOTIFY)
2868 r->rtm_flags |= RTM_F_NOTIFY;
2870 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2872 if (rt->fl.fl4_src) {
2873 r->rtm_src_len = 32;
2874 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
2877 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2878 #ifdef CONFIG_IP_ROUTE_CLASSID
2879 if (rt->dst.tclassid)
2880 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2882 if (rt_is_input_route(rt))
2883 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2884 else if (rt->rt_src != rt->fl.fl4_src)
2885 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2887 if (rt->rt_dst != rt->rt_gateway)
2888 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2890 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2891 goto nla_put_failure;
2894 NLA_PUT_BE32(skb, RTA_MARK, rt->fl.mark);
2896 error = rt->dst.error;
2897 expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
2899 inet_peer_refcheck(rt->peer);
2900 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2901 if (rt->peer->tcp_ts_stamp) {
2902 ts = rt->peer->tcp_ts;
2903 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2907 if (rt_is_input_route(rt)) {
2908 #ifdef CONFIG_IP_MROUTE
2909 __be32 dst = rt->rt_dst;
2911 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2912 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2913 int err = ipmr_get_route(net, skb, r, nowait);
2918 goto nla_put_failure;
2920 if (err == -EMSGSIZE)
2921 goto nla_put_failure;
2927 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
2930 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2931 expires, error) < 0)
2932 goto nla_put_failure;
2934 return nlmsg_end(skb, nlh);
2937 nlmsg_cancel(skb, nlh);
2941 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2943 struct net *net = sock_net(in_skb->sk);
2945 struct nlattr *tb[RTA_MAX+1];
2946 struct rtable *rt = NULL;
2952 struct sk_buff *skb;
2954 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2958 rtm = nlmsg_data(nlh);
2960 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2966 /* Reserve room for dummy headers, this skb can pass
2967 through good chunk of routing engine.
2969 skb_reset_mac_header(skb);
2970 skb_reset_network_header(skb);
2972 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2973 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2974 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2976 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2977 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2978 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2979 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2982 struct net_device *dev;
2984 dev = __dev_get_by_index(net, iif);
2990 skb->protocol = htons(ETH_P_IP);
2994 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2997 rt = skb_rtable(skb);
2998 if (err == 0 && rt->dst.error)
2999 err = -rt->dst.error;
3004 .fl4_tos = rtm->rtm_tos,
3005 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
3008 err = ip_route_output_key(net, &rt, &fl);
3014 skb_dst_set(skb, &rt->dst);
3015 if (rtm->rtm_flags & RTM_F_NOTIFY)
3016 rt->rt_flags |= RTCF_NOTIFY;
3018 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3019 RTM_NEWROUTE, 0, 0);
3023 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3032 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3039 net = sock_net(skb->sk);
3044 s_idx = idx = cb->args[1];
3045 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3046 if (!rt_hash_table[h].chain)
3049 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3050 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3051 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3053 if (rt_is_expired(rt))
3055 skb_dst_set_noref(skb, &rt->dst);
3056 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3057 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3058 1, NLM_F_MULTI) <= 0) {
3060 rcu_read_unlock_bh();
3065 rcu_read_unlock_bh();
3074 void ip_rt_multicast_event(struct in_device *in_dev)
3076 rt_cache_flush(dev_net(in_dev->dev), 0);
3079 #ifdef CONFIG_SYSCTL
3080 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3081 void __user *buffer,
3082 size_t *lenp, loff_t *ppos)
3089 memcpy(&ctl, __ctl, sizeof(ctl));
3090 ctl.data = &flush_delay;
3091 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3093 net = (struct net *)__ctl->extra1;
3094 rt_cache_flush(net, flush_delay);
3101 static ctl_table ipv4_route_table[] = {
3103 .procname = "gc_thresh",
3104 .data = &ipv4_dst_ops.gc_thresh,
3105 .maxlen = sizeof(int),
3107 .proc_handler = proc_dointvec,
3110 .procname = "max_size",
3111 .data = &ip_rt_max_size,
3112 .maxlen = sizeof(int),
3114 .proc_handler = proc_dointvec,
3117 /* Deprecated. Use gc_min_interval_ms */
3119 .procname = "gc_min_interval",
3120 .data = &ip_rt_gc_min_interval,
3121 .maxlen = sizeof(int),
3123 .proc_handler = proc_dointvec_jiffies,
3126 .procname = "gc_min_interval_ms",
3127 .data = &ip_rt_gc_min_interval,
3128 .maxlen = sizeof(int),
3130 .proc_handler = proc_dointvec_ms_jiffies,
3133 .procname = "gc_timeout",
3134 .data = &ip_rt_gc_timeout,
3135 .maxlen = sizeof(int),
3137 .proc_handler = proc_dointvec_jiffies,
3140 .procname = "gc_interval",
3141 .data = &ip_rt_gc_interval,
3142 .maxlen = sizeof(int),
3144 .proc_handler = proc_dointvec_jiffies,
3147 .procname = "redirect_load",
3148 .data = &ip_rt_redirect_load,
3149 .maxlen = sizeof(int),
3151 .proc_handler = proc_dointvec,
3154 .procname = "redirect_number",
3155 .data = &ip_rt_redirect_number,
3156 .maxlen = sizeof(int),
3158 .proc_handler = proc_dointvec,
3161 .procname = "redirect_silence",
3162 .data = &ip_rt_redirect_silence,
3163 .maxlen = sizeof(int),
3165 .proc_handler = proc_dointvec,
3168 .procname = "error_cost",
3169 .data = &ip_rt_error_cost,
3170 .maxlen = sizeof(int),
3172 .proc_handler = proc_dointvec,
3175 .procname = "error_burst",
3176 .data = &ip_rt_error_burst,
3177 .maxlen = sizeof(int),
3179 .proc_handler = proc_dointvec,
3182 .procname = "gc_elasticity",
3183 .data = &ip_rt_gc_elasticity,
3184 .maxlen = sizeof(int),
3186 .proc_handler = proc_dointvec,
3189 .procname = "mtu_expires",
3190 .data = &ip_rt_mtu_expires,
3191 .maxlen = sizeof(int),
3193 .proc_handler = proc_dointvec_jiffies,
3196 .procname = "min_pmtu",
3197 .data = &ip_rt_min_pmtu,
3198 .maxlen = sizeof(int),
3200 .proc_handler = proc_dointvec,
3203 .procname = "min_adv_mss",
3204 .data = &ip_rt_min_advmss,
3205 .maxlen = sizeof(int),
3207 .proc_handler = proc_dointvec,
3212 static struct ctl_table empty[1];
3214 static struct ctl_table ipv4_skeleton[] =
3216 { .procname = "route",
3217 .mode = 0555, .child = ipv4_route_table},
3218 { .procname = "neigh",
3219 .mode = 0555, .child = empty},
3223 static __net_initdata struct ctl_path ipv4_path[] = {
3224 { .procname = "net", },
3225 { .procname = "ipv4", },
3229 static struct ctl_table ipv4_route_flush_table[] = {
3231 .procname = "flush",
3232 .maxlen = sizeof(int),
3234 .proc_handler = ipv4_sysctl_rtcache_flush,
3239 static __net_initdata struct ctl_path ipv4_route_path[] = {
3240 { .procname = "net", },
3241 { .procname = "ipv4", },
3242 { .procname = "route", },
3246 static __net_init int sysctl_route_net_init(struct net *net)
3248 struct ctl_table *tbl;
3250 tbl = ipv4_route_flush_table;
3251 if (!net_eq(net, &init_net)) {
3252 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3256 tbl[0].extra1 = net;
3258 net->ipv4.route_hdr =
3259 register_net_sysctl_table(net, ipv4_route_path, tbl);
3260 if (net->ipv4.route_hdr == NULL)
3265 if (tbl != ipv4_route_flush_table)
3271 static __net_exit void sysctl_route_net_exit(struct net *net)
3273 struct ctl_table *tbl;
3275 tbl = net->ipv4.route_hdr->ctl_table_arg;
3276 unregister_net_sysctl_table(net->ipv4.route_hdr);
3277 BUG_ON(tbl == ipv4_route_flush_table);
3281 static __net_initdata struct pernet_operations sysctl_route_ops = {
3282 .init = sysctl_route_net_init,
3283 .exit = sysctl_route_net_exit,
3287 static __net_init int rt_genid_init(struct net *net)
3289 get_random_bytes(&net->ipv4.rt_genid,
3290 sizeof(net->ipv4.rt_genid));
3294 static __net_initdata struct pernet_operations rt_genid_ops = {
3295 .init = rt_genid_init,
3299 #ifdef CONFIG_IP_ROUTE_CLASSID
3300 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3301 #endif /* CONFIG_IP_ROUTE_CLASSID */
3303 static __initdata unsigned long rhash_entries;
3304 static int __init set_rhash_entries(char *str)
3308 rhash_entries = simple_strtoul(str, &str, 0);
3311 __setup("rhash_entries=", set_rhash_entries);
3313 int __init ip_rt_init(void)
3317 #ifdef CONFIG_IP_ROUTE_CLASSID
3318 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3320 panic("IP: failed to allocate ip_rt_acct\n");
3323 ipv4_dst_ops.kmem_cachep =
3324 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3325 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3327 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3329 if (dst_entries_init(&ipv4_dst_ops) < 0)
3330 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3332 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3333 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3335 rt_hash_table = (struct rt_hash_bucket *)
3336 alloc_large_system_hash("IP route cache",
3337 sizeof(struct rt_hash_bucket),
3339 (totalram_pages >= 128 * 1024) ?
3344 rhash_entries ? 0 : 512 * 1024);
3345 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3346 rt_hash_lock_init();
3348 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3349 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3354 /* All the timers, started at system startup tend
3355 to synchronize. Perturb it a bit.
3357 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func);
3358 expires_ljiffies = jiffies;
3359 schedule_delayed_work(&expires_work,
3360 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3362 if (ip_rt_proc_init())
3363 printk(KERN_ERR "Unable to create route proc files\n");
3366 xfrm4_init(ip_rt_max_size);
3368 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3370 #ifdef CONFIG_SYSCTL
3371 register_pernet_subsys(&sysctl_route_ops);
3373 register_pernet_subsys(&rt_genid_ops);
3377 #ifdef CONFIG_SYSCTL
3379 * We really need to sanitize the damn ipv4 init order, then all
3380 * this nonsense will go away.
3382 void __init ip_static_sysctl_init(void)
3384 register_sysctl_paths(ipv4_path, ipv4_skeleton);