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_init_metrics(struct rtable *rt, struct fib_info *fi)
1862 if (!(rt->fl.flags & FLOWI_FLAG_PRECOW_METRICS)) {
1864 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1866 atomic_inc(&fi->fib_clntref);
1868 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1870 struct inet_peer *peer;
1873 rt_bind_peer(rt, 1);
1877 if (inet_metrics_new(peer))
1878 memcpy(peer->metrics, fi->fib_metrics,
1879 sizeof(u32) * RTAX_MAX);
1880 dst_init_metrics(&rt->dst, peer->metrics, false);
1884 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
1886 struct dst_entry *dst = &rt->dst;
1887 struct fib_info *fi = res->fi;
1890 if (FIB_RES_GW(*res) &&
1891 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1892 rt->rt_gateway = FIB_RES_GW(*res);
1893 rt_init_metrics(rt, fi);
1894 #ifdef CONFIG_IP_ROUTE_CLASSID
1895 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1899 if (dst_mtu(dst) > IP_MAX_MTU)
1900 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1901 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1902 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1904 #ifdef CONFIG_IP_ROUTE_CLASSID
1905 #ifdef CONFIG_IP_MULTIPLE_TABLES
1906 set_class_tag(rt, fib_rules_tclass(res));
1908 set_class_tag(rt, itag);
1910 rt->rt_type = res->type;
1913 /* called in rcu_read_lock() section */
1914 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1915 u8 tos, struct net_device *dev, int our)
1920 struct in_device *in_dev = __in_dev_get_rcu(dev);
1924 /* Primary sanity checks. */
1929 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1930 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1933 if (ipv4_is_zeronet(saddr)) {
1934 if (!ipv4_is_local_multicast(daddr))
1936 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1938 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
1943 rth = dst_alloc(&ipv4_dst_ops);
1947 rth->dst.output = ip_rt_bug;
1948 rth->dst.obsolete = -1;
1950 atomic_set(&rth->dst.__refcnt, 1);
1951 rth->dst.flags= DST_HOST;
1952 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1953 rth->dst.flags |= DST_NOPOLICY;
1954 rth->fl.fl4_dst = daddr;
1955 rth->rt_dst = daddr;
1956 rth->fl.fl4_tos = tos;
1957 rth->fl.mark = skb->mark;
1958 rth->fl.fl4_src = saddr;
1959 rth->rt_src = saddr;
1960 #ifdef CONFIG_IP_ROUTE_CLASSID
1961 rth->dst.tclassid = itag;
1964 rth->fl.iif = dev->ifindex;
1965 rth->dst.dev = init_net.loopback_dev;
1966 dev_hold(rth->dst.dev);
1968 rth->rt_gateway = daddr;
1969 rth->rt_spec_dst= spec_dst;
1970 rth->rt_genid = rt_genid(dev_net(dev));
1971 rth->rt_flags = RTCF_MULTICAST;
1972 rth->rt_type = RTN_MULTICAST;
1974 rth->dst.input= ip_local_deliver;
1975 rth->rt_flags |= RTCF_LOCAL;
1978 #ifdef CONFIG_IP_MROUTE
1979 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1980 rth->dst.input = ip_mr_input;
1982 RT_CACHE_STAT_INC(in_slow_mc);
1984 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1985 return rt_intern_hash(hash, rth, NULL, skb, dev->ifindex);
1996 static void ip_handle_martian_source(struct net_device *dev,
1997 struct in_device *in_dev,
1998 struct sk_buff *skb,
2002 RT_CACHE_STAT_INC(in_martian_src);
2003 #ifdef CONFIG_IP_ROUTE_VERBOSE
2004 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
2006 * RFC1812 recommendation, if source is martian,
2007 * the only hint is MAC header.
2009 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
2010 &daddr, &saddr, dev->name);
2011 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
2013 const unsigned char *p = skb_mac_header(skb);
2014 printk(KERN_WARNING "ll header: ");
2015 for (i = 0; i < dev->hard_header_len; i++, p++) {
2017 if (i < (dev->hard_header_len - 1))
2026 /* called in rcu_read_lock() section */
2027 static int __mkroute_input(struct sk_buff *skb,
2028 struct fib_result *res,
2029 struct in_device *in_dev,
2030 __be32 daddr, __be32 saddr, u32 tos,
2031 struct rtable **result)
2035 struct in_device *out_dev;
2036 unsigned int flags = 0;
2040 /* get a working reference to the output device */
2041 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
2042 if (out_dev == NULL) {
2043 if (net_ratelimit())
2044 printk(KERN_CRIT "Bug in ip_route_input" \
2045 "_slow(). Please, report\n");
2050 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
2051 in_dev->dev, &spec_dst, &itag, skb->mark);
2053 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2060 flags |= RTCF_DIRECTSRC;
2062 if (out_dev == in_dev && err &&
2063 (IN_DEV_SHARED_MEDIA(out_dev) ||
2064 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2065 flags |= RTCF_DOREDIRECT;
2067 if (skb->protocol != htons(ETH_P_IP)) {
2068 /* Not IP (i.e. ARP). Do not create route, if it is
2069 * invalid for proxy arp. DNAT routes are always valid.
2071 * Proxy arp feature have been extended to allow, ARP
2072 * replies back to the same interface, to support
2073 * Private VLAN switch technologies. See arp.c.
2075 if (out_dev == in_dev &&
2076 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2083 rth = dst_alloc(&ipv4_dst_ops);
2089 atomic_set(&rth->dst.__refcnt, 1);
2090 rth->dst.flags= DST_HOST;
2091 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2092 rth->dst.flags |= DST_NOPOLICY;
2093 if (IN_DEV_CONF_GET(out_dev, NOXFRM))
2094 rth->dst.flags |= DST_NOXFRM;
2095 rth->fl.fl4_dst = daddr;
2096 rth->rt_dst = daddr;
2097 rth->fl.fl4_tos = tos;
2098 rth->fl.mark = skb->mark;
2099 rth->fl.fl4_src = saddr;
2100 rth->rt_src = saddr;
2101 rth->rt_gateway = daddr;
2103 rth->fl.iif = in_dev->dev->ifindex;
2104 rth->dst.dev = (out_dev)->dev;
2105 dev_hold(rth->dst.dev);
2107 rth->rt_spec_dst= spec_dst;
2109 rth->dst.obsolete = -1;
2110 rth->dst.input = ip_forward;
2111 rth->dst.output = ip_output;
2112 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2114 rt_set_nexthop(rth, res, itag);
2116 rth->rt_flags = flags;
2124 static int ip_mkroute_input(struct sk_buff *skb,
2125 struct fib_result *res,
2126 const struct flowi *fl,
2127 struct in_device *in_dev,
2128 __be32 daddr, __be32 saddr, u32 tos)
2130 struct rtable* rth = NULL;
2134 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2135 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
2136 fib_select_multipath(fl, res);
2139 /* create a routing cache entry */
2140 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2144 /* put it into the cache */
2145 hash = rt_hash(daddr, saddr, fl->iif,
2146 rt_genid(dev_net(rth->dst.dev)));
2147 return rt_intern_hash(hash, rth, NULL, skb, fl->iif);
2151 * NOTE. We drop all the packets that has local source
2152 * addresses, because every properly looped back packet
2153 * must have correct destination already attached by output routine.
2155 * Such approach solves two big problems:
2156 * 1. Not simplex devices are handled properly.
2157 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2158 * called with rcu_read_lock()
2161 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2162 u8 tos, struct net_device *dev)
2164 struct fib_result res;
2165 struct in_device *in_dev = __in_dev_get_rcu(dev);
2166 struct flowi fl = { .fl4_dst = daddr,
2169 .fl4_scope = RT_SCOPE_UNIVERSE,
2171 .iif = dev->ifindex };
2174 struct rtable * rth;
2178 struct net * net = dev_net(dev);
2180 /* IP on this device is disabled. */
2185 /* Check for the most weird martians, which can be not detected
2189 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2190 ipv4_is_loopback(saddr))
2191 goto martian_source;
2193 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2196 /* Accept zero addresses only to limited broadcast;
2197 * I even do not know to fix it or not. Waiting for complains :-)
2199 if (ipv4_is_zeronet(saddr))
2200 goto martian_source;
2202 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2203 goto martian_destination;
2206 * Now we are ready to route packet.
2208 err = fib_lookup(net, &fl, &res);
2210 if (!IN_DEV_FORWARD(in_dev))
2215 RT_CACHE_STAT_INC(in_slow_tot);
2217 if (res.type == RTN_BROADCAST)
2220 if (res.type == RTN_LOCAL) {
2221 err = fib_validate_source(saddr, daddr, tos,
2222 net->loopback_dev->ifindex,
2223 dev, &spec_dst, &itag, skb->mark);
2225 goto martian_source_keep_err;
2227 flags |= RTCF_DIRECTSRC;
2232 if (!IN_DEV_FORWARD(in_dev))
2234 if (res.type != RTN_UNICAST)
2235 goto martian_destination;
2237 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
2241 if (skb->protocol != htons(ETH_P_IP))
2244 if (ipv4_is_zeronet(saddr))
2245 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2247 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
2250 goto martian_source_keep_err;
2252 flags |= RTCF_DIRECTSRC;
2254 flags |= RTCF_BROADCAST;
2255 res.type = RTN_BROADCAST;
2256 RT_CACHE_STAT_INC(in_brd);
2259 rth = dst_alloc(&ipv4_dst_ops);
2263 rth->dst.output= ip_rt_bug;
2264 rth->dst.obsolete = -1;
2265 rth->rt_genid = rt_genid(net);
2267 atomic_set(&rth->dst.__refcnt, 1);
2268 rth->dst.flags= DST_HOST;
2269 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2270 rth->dst.flags |= DST_NOPOLICY;
2271 rth->fl.fl4_dst = daddr;
2272 rth->rt_dst = daddr;
2273 rth->fl.fl4_tos = tos;
2274 rth->fl.mark = skb->mark;
2275 rth->fl.fl4_src = saddr;
2276 rth->rt_src = saddr;
2277 #ifdef CONFIG_IP_ROUTE_CLASSID
2278 rth->dst.tclassid = itag;
2281 rth->fl.iif = dev->ifindex;
2282 rth->dst.dev = net->loopback_dev;
2283 dev_hold(rth->dst.dev);
2284 rth->rt_gateway = daddr;
2285 rth->rt_spec_dst= spec_dst;
2286 rth->dst.input= ip_local_deliver;
2287 rth->rt_flags = flags|RTCF_LOCAL;
2288 if (res.type == RTN_UNREACHABLE) {
2289 rth->dst.input= ip_error;
2290 rth->dst.error= -err;
2291 rth->rt_flags &= ~RTCF_LOCAL;
2293 rth->rt_type = res.type;
2294 hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
2295 err = rt_intern_hash(hash, rth, NULL, skb, fl.iif);
2299 RT_CACHE_STAT_INC(in_no_route);
2300 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2301 res.type = RTN_UNREACHABLE;
2307 * Do not cache martian addresses: they should be logged (RFC1812)
2309 martian_destination:
2310 RT_CACHE_STAT_INC(in_martian_dst);
2311 #ifdef CONFIG_IP_ROUTE_VERBOSE
2312 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2313 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2314 &daddr, &saddr, dev->name);
2318 err = -EHOSTUNREACH;
2331 martian_source_keep_err:
2332 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2336 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2337 u8 tos, struct net_device *dev, bool noref)
2339 struct rtable * rth;
2341 int iif = dev->ifindex;
2349 if (!rt_caching(net))
2352 tos &= IPTOS_RT_MASK;
2353 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2355 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2356 rth = rcu_dereference(rth->dst.rt_next)) {
2357 if ((((__force u32)rth->fl.fl4_dst ^ (__force u32)daddr) |
2358 ((__force u32)rth->fl.fl4_src ^ (__force u32)saddr) |
2359 (rth->fl.iif ^ iif) |
2361 (rth->fl.fl4_tos ^ tos)) == 0 &&
2362 rth->fl.mark == skb->mark &&
2363 net_eq(dev_net(rth->dst.dev), net) &&
2364 !rt_is_expired(rth)) {
2366 dst_use_noref(&rth->dst, jiffies);
2367 skb_dst_set_noref(skb, &rth->dst);
2369 dst_use(&rth->dst, jiffies);
2370 skb_dst_set(skb, &rth->dst);
2372 RT_CACHE_STAT_INC(in_hit);
2376 RT_CACHE_STAT_INC(in_hlist_search);
2380 /* Multicast recognition logic is moved from route cache to here.
2381 The problem was that too many Ethernet cards have broken/missing
2382 hardware multicast filters :-( As result the host on multicasting
2383 network acquires a lot of useless route cache entries, sort of
2384 SDR messages from all the world. Now we try to get rid of them.
2385 Really, provided software IP multicast filter is organized
2386 reasonably (at least, hashed), it does not result in a slowdown
2387 comparing with route cache reject entries.
2388 Note, that multicast routers are not affected, because
2389 route cache entry is created eventually.
2391 if (ipv4_is_multicast(daddr)) {
2392 struct in_device *in_dev = __in_dev_get_rcu(dev);
2395 int our = ip_check_mc(in_dev, daddr, saddr,
2396 ip_hdr(skb)->protocol);
2398 #ifdef CONFIG_IP_MROUTE
2400 (!ipv4_is_local_multicast(daddr) &&
2401 IN_DEV_MFORWARD(in_dev))
2404 int res = ip_route_input_mc(skb, daddr, saddr,
2413 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2417 EXPORT_SYMBOL(ip_route_input_common);
2419 /* called with rcu_read_lock() */
2420 static int __mkroute_output(struct rtable **result,
2421 struct fib_result *res,
2422 const struct flowi *fl,
2423 const struct flowi *oldflp,
2424 struct net_device *dev_out,
2428 struct in_device *in_dev;
2429 u32 tos = RT_FL_TOS(oldflp);
2431 if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags & IFF_LOOPBACK))
2434 if (ipv4_is_lbcast(fl->fl4_dst))
2435 res->type = RTN_BROADCAST;
2436 else if (ipv4_is_multicast(fl->fl4_dst))
2437 res->type = RTN_MULTICAST;
2438 else if (ipv4_is_zeronet(fl->fl4_dst))
2441 if (dev_out->flags & IFF_LOOPBACK)
2442 flags |= RTCF_LOCAL;
2444 in_dev = __in_dev_get_rcu(dev_out);
2448 if (res->type == RTN_BROADCAST) {
2449 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2451 } else if (res->type == RTN_MULTICAST) {
2452 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2453 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2455 flags &= ~RTCF_LOCAL;
2456 /* If multicast route do not exist use
2457 * default one, but do not gateway in this case.
2460 if (res->fi && res->prefixlen < 4)
2465 rth = dst_alloc(&ipv4_dst_ops);
2469 atomic_set(&rth->dst.__refcnt, 1);
2470 rth->dst.flags= DST_HOST;
2471 if (IN_DEV_CONF_GET(in_dev, NOXFRM))
2472 rth->dst.flags |= DST_NOXFRM;
2473 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2474 rth->dst.flags |= DST_NOPOLICY;
2476 rth->fl.fl4_dst = oldflp->fl4_dst;
2477 rth->fl.fl4_tos = tos;
2478 rth->fl.fl4_src = oldflp->fl4_src;
2479 rth->fl.oif = oldflp->oif;
2480 rth->fl.mark = oldflp->mark;
2481 rth->rt_dst = fl->fl4_dst;
2482 rth->rt_src = fl->fl4_src;
2483 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2484 /* get references to the devices that are to be hold by the routing
2486 rth->dst.dev = dev_out;
2488 rth->rt_gateway = fl->fl4_dst;
2489 rth->rt_spec_dst= fl->fl4_src;
2491 rth->dst.output=ip_output;
2492 rth->dst.obsolete = -1;
2493 rth->rt_genid = rt_genid(dev_net(dev_out));
2495 RT_CACHE_STAT_INC(out_slow_tot);
2497 if (flags & RTCF_LOCAL) {
2498 rth->dst.input = ip_local_deliver;
2499 rth->rt_spec_dst = fl->fl4_dst;
2501 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2502 rth->rt_spec_dst = fl->fl4_src;
2503 if (flags & RTCF_LOCAL &&
2504 !(dev_out->flags & IFF_LOOPBACK)) {
2505 rth->dst.output = ip_mc_output;
2506 RT_CACHE_STAT_INC(out_slow_mc);
2508 #ifdef CONFIG_IP_MROUTE
2509 if (res->type == RTN_MULTICAST) {
2510 if (IN_DEV_MFORWARD(in_dev) &&
2511 !ipv4_is_local_multicast(oldflp->fl4_dst)) {
2512 rth->dst.input = ip_mr_input;
2513 rth->dst.output = ip_mc_output;
2519 rt_set_nexthop(rth, res, 0);
2521 rth->rt_flags = flags;
2526 /* called with rcu_read_lock() */
2527 static int ip_mkroute_output(struct rtable **rp,
2528 struct fib_result *res,
2529 const struct flowi *fl,
2530 const struct flowi *oldflp,
2531 struct net_device *dev_out,
2534 struct rtable *rth = NULL;
2535 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
2538 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
2539 rt_genid(dev_net(dev_out)));
2540 err = rt_intern_hash(hash, rth, rp, NULL, oldflp->oif);
2547 * Major route resolver routine.
2548 * called with rcu_read_lock();
2551 static int ip_route_output_slow(struct net *net, struct rtable **rp,
2552 const struct flowi *oldflp)
2554 u32 tos = RT_FL_TOS(oldflp);
2555 struct flowi fl = { .fl4_dst = oldflp->fl4_dst,
2556 .fl4_src = oldflp->fl4_src,
2557 .fl4_tos = tos & IPTOS_RT_MASK,
2558 .fl4_scope = ((tos & RTO_ONLINK) ?
2559 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE),
2560 .mark = oldflp->mark,
2561 .iif = net->loopback_dev->ifindex,
2562 .oif = oldflp->oif };
2563 struct fib_result res;
2564 unsigned int flags = 0;
2565 struct net_device *dev_out = NULL;
2570 #ifdef CONFIG_IP_MULTIPLE_TABLES
2574 if (oldflp->fl4_src) {
2576 if (ipv4_is_multicast(oldflp->fl4_src) ||
2577 ipv4_is_lbcast(oldflp->fl4_src) ||
2578 ipv4_is_zeronet(oldflp->fl4_src))
2581 /* I removed check for oif == dev_out->oif here.
2582 It was wrong for two reasons:
2583 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2584 is assigned to multiple interfaces.
2585 2. Moreover, we are allowed to send packets with saddr
2586 of another iface. --ANK
2589 if (oldflp->oif == 0 &&
2590 (ipv4_is_multicast(oldflp->fl4_dst) ||
2591 ipv4_is_lbcast(oldflp->fl4_dst))) {
2592 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2593 dev_out = __ip_dev_find(net, oldflp->fl4_src, false);
2594 if (dev_out == NULL)
2597 /* Special hack: user can direct multicasts
2598 and limited broadcast via necessary interface
2599 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2600 This hack is not just for fun, it allows
2601 vic,vat and friends to work.
2602 They bind socket to loopback, set ttl to zero
2603 and expect that it will work.
2604 From the viewpoint of routing cache they are broken,
2605 because we are not allowed to build multicast path
2606 with loopback source addr (look, routing cache
2607 cannot know, that ttl is zero, so that packet
2608 will not leave this host and route is valid).
2609 Luckily, this hack is good workaround.
2612 fl.oif = dev_out->ifindex;
2616 if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
2617 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2618 if (!__ip_dev_find(net, oldflp->fl4_src, false))
2625 dev_out = dev_get_by_index_rcu(net, oldflp->oif);
2627 if (dev_out == NULL)
2630 /* RACE: Check return value of inet_select_addr instead. */
2631 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2635 if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
2636 ipv4_is_lbcast(oldflp->fl4_dst)) {
2638 fl.fl4_src = inet_select_addr(dev_out, 0,
2643 if (ipv4_is_multicast(oldflp->fl4_dst))
2644 fl.fl4_src = inet_select_addr(dev_out, 0,
2646 else if (!oldflp->fl4_dst)
2647 fl.fl4_src = inet_select_addr(dev_out, 0,
2653 fl.fl4_dst = fl.fl4_src;
2655 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2656 dev_out = net->loopback_dev;
2657 fl.oif = net->loopback_dev->ifindex;
2658 res.type = RTN_LOCAL;
2659 flags |= RTCF_LOCAL;
2663 if (fib_lookup(net, &fl, &res)) {
2666 /* Apparently, routing tables are wrong. Assume,
2667 that the destination is on link.
2670 Because we are allowed to send to iface
2671 even if it has NO routes and NO assigned
2672 addresses. When oif is specified, routing
2673 tables are looked up with only one purpose:
2674 to catch if destination is gatewayed, rather than
2675 direct. Moreover, if MSG_DONTROUTE is set,
2676 we send packet, ignoring both routing tables
2677 and ifaddr state. --ANK
2680 We could make it even if oif is unknown,
2681 likely IPv6, but we do not.
2684 if (fl.fl4_src == 0)
2685 fl.fl4_src = inet_select_addr(dev_out, 0,
2687 res.type = RTN_UNICAST;
2694 if (res.type == RTN_LOCAL) {
2696 if (res.fi->fib_prefsrc)
2697 fl.fl4_src = res.fi->fib_prefsrc;
2699 fl.fl4_src = fl.fl4_dst;
2701 dev_out = net->loopback_dev;
2702 fl.oif = dev_out->ifindex;
2704 flags |= RTCF_LOCAL;
2708 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2709 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2710 fib_select_multipath(&fl, &res);
2713 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2714 fib_select_default(&res);
2717 fl.fl4_src = FIB_RES_PREFSRC(res);
2719 dev_out = FIB_RES_DEV(res);
2720 fl.oif = dev_out->ifindex;
2724 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
2729 int __ip_route_output_key(struct net *net, struct rtable **rp,
2730 const struct flowi *flp)
2736 if (!rt_caching(net))
2739 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net));
2742 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2743 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2744 if (rth->fl.fl4_dst == flp->fl4_dst &&
2745 rth->fl.fl4_src == flp->fl4_src &&
2746 rt_is_output_route(rth) &&
2747 rth->fl.oif == flp->oif &&
2748 rth->fl.mark == flp->mark &&
2749 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2750 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2751 net_eq(dev_net(rth->dst.dev), net) &&
2752 !rt_is_expired(rth)) {
2753 dst_use(&rth->dst, jiffies);
2754 RT_CACHE_STAT_INC(out_hit);
2755 rcu_read_unlock_bh();
2759 RT_CACHE_STAT_INC(out_hlist_search);
2761 rcu_read_unlock_bh();
2765 res = ip_route_output_slow(net, rp, flp);
2769 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2771 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2776 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst)
2781 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2785 static struct dst_ops ipv4_dst_blackhole_ops = {
2787 .protocol = cpu_to_be16(ETH_P_IP),
2788 .destroy = ipv4_dst_destroy,
2789 .check = ipv4_blackhole_dst_check,
2790 .default_mtu = ipv4_blackhole_default_mtu,
2791 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2795 static int ipv4_dst_blackhole(struct net *net, struct rtable **rp, struct flowi *flp)
2797 struct rtable *ort = *rp;
2798 struct rtable *rt = (struct rtable *)
2799 dst_alloc(&ipv4_dst_blackhole_ops);
2802 struct dst_entry *new = &rt->dst;
2804 atomic_set(&new->__refcnt, 1);
2806 new->input = dst_discard;
2807 new->output = dst_discard;
2808 dst_copy_metrics(new, &ort->dst);
2810 new->dev = ort->dst.dev;
2816 rt->rt_genid = rt_genid(net);
2817 rt->rt_flags = ort->rt_flags;
2818 rt->rt_type = ort->rt_type;
2819 rt->rt_dst = ort->rt_dst;
2820 rt->rt_src = ort->rt_src;
2821 rt->rt_iif = ort->rt_iif;
2822 rt->rt_gateway = ort->rt_gateway;
2823 rt->rt_spec_dst = ort->rt_spec_dst;
2824 rt->peer = ort->peer;
2826 atomic_inc(&rt->peer->refcnt);
2829 atomic_inc(&rt->fi->fib_clntref);
2834 dst_release(&(*rp)->dst);
2836 return rt ? 0 : -ENOMEM;
2839 int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
2840 struct sock *sk, int flags)
2844 if ((err = __ip_route_output_key(net, rp, flp)) != 0)
2849 flp->fl4_src = (*rp)->rt_src;
2851 flp->fl4_dst = (*rp)->rt_dst;
2852 err = __xfrm_lookup(net, (struct dst_entry **)rp, flp, sk,
2853 flags ? XFRM_LOOKUP_WAIT : 0);
2854 if (err == -EREMOTE)
2855 err = ipv4_dst_blackhole(net, rp, flp);
2862 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2864 int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp)
2866 return ip_route_output_flow(net, rp, flp, NULL, 0);
2868 EXPORT_SYMBOL(ip_route_output_key);
2870 static int rt_fill_info(struct net *net,
2871 struct sk_buff *skb, u32 pid, u32 seq, int event,
2872 int nowait, unsigned int flags)
2874 struct rtable *rt = skb_rtable(skb);
2876 struct nlmsghdr *nlh;
2878 u32 id = 0, ts = 0, tsage = 0, error;
2880 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2884 r = nlmsg_data(nlh);
2885 r->rtm_family = AF_INET;
2886 r->rtm_dst_len = 32;
2888 r->rtm_tos = rt->fl.fl4_tos;
2889 r->rtm_table = RT_TABLE_MAIN;
2890 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2891 r->rtm_type = rt->rt_type;
2892 r->rtm_scope = RT_SCOPE_UNIVERSE;
2893 r->rtm_protocol = RTPROT_UNSPEC;
2894 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2895 if (rt->rt_flags & RTCF_NOTIFY)
2896 r->rtm_flags |= RTM_F_NOTIFY;
2898 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2900 if (rt->fl.fl4_src) {
2901 r->rtm_src_len = 32;
2902 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
2905 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2906 #ifdef CONFIG_IP_ROUTE_CLASSID
2907 if (rt->dst.tclassid)
2908 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2910 if (rt_is_input_route(rt))
2911 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2912 else if (rt->rt_src != rt->fl.fl4_src)
2913 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2915 if (rt->rt_dst != rt->rt_gateway)
2916 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2918 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2919 goto nla_put_failure;
2922 NLA_PUT_BE32(skb, RTA_MARK, rt->fl.mark);
2924 error = rt->dst.error;
2925 expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
2927 inet_peer_refcheck(rt->peer);
2928 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2929 if (rt->peer->tcp_ts_stamp) {
2930 ts = rt->peer->tcp_ts;
2931 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2935 if (rt_is_input_route(rt)) {
2936 #ifdef CONFIG_IP_MROUTE
2937 __be32 dst = rt->rt_dst;
2939 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2940 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2941 int err = ipmr_get_route(net, skb, r, nowait);
2946 goto nla_put_failure;
2948 if (err == -EMSGSIZE)
2949 goto nla_put_failure;
2955 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
2958 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2959 expires, error) < 0)
2960 goto nla_put_failure;
2962 return nlmsg_end(skb, nlh);
2965 nlmsg_cancel(skb, nlh);
2969 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2971 struct net *net = sock_net(in_skb->sk);
2973 struct nlattr *tb[RTA_MAX+1];
2974 struct rtable *rt = NULL;
2980 struct sk_buff *skb;
2982 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2986 rtm = nlmsg_data(nlh);
2988 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2994 /* Reserve room for dummy headers, this skb can pass
2995 through good chunk of routing engine.
2997 skb_reset_mac_header(skb);
2998 skb_reset_network_header(skb);
3000 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
3001 ip_hdr(skb)->protocol = IPPROTO_ICMP;
3002 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
3004 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
3005 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
3006 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
3007 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
3010 struct net_device *dev;
3012 dev = __dev_get_by_index(net, iif);
3018 skb->protocol = htons(ETH_P_IP);
3022 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
3025 rt = skb_rtable(skb);
3026 if (err == 0 && rt->dst.error)
3027 err = -rt->dst.error;
3032 .fl4_tos = rtm->rtm_tos,
3033 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
3036 err = ip_route_output_key(net, &rt, &fl);
3042 skb_dst_set(skb, &rt->dst);
3043 if (rtm->rtm_flags & RTM_F_NOTIFY)
3044 rt->rt_flags |= RTCF_NOTIFY;
3046 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3047 RTM_NEWROUTE, 0, 0);
3051 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3060 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3067 net = sock_net(skb->sk);
3072 s_idx = idx = cb->args[1];
3073 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3074 if (!rt_hash_table[h].chain)
3077 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3078 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3079 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3081 if (rt_is_expired(rt))
3083 skb_dst_set_noref(skb, &rt->dst);
3084 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3085 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3086 1, NLM_F_MULTI) <= 0) {
3088 rcu_read_unlock_bh();
3093 rcu_read_unlock_bh();
3102 void ip_rt_multicast_event(struct in_device *in_dev)
3104 rt_cache_flush(dev_net(in_dev->dev), 0);
3107 #ifdef CONFIG_SYSCTL
3108 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3109 void __user *buffer,
3110 size_t *lenp, loff_t *ppos)
3117 memcpy(&ctl, __ctl, sizeof(ctl));
3118 ctl.data = &flush_delay;
3119 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3121 net = (struct net *)__ctl->extra1;
3122 rt_cache_flush(net, flush_delay);
3129 static ctl_table ipv4_route_table[] = {
3131 .procname = "gc_thresh",
3132 .data = &ipv4_dst_ops.gc_thresh,
3133 .maxlen = sizeof(int),
3135 .proc_handler = proc_dointvec,
3138 .procname = "max_size",
3139 .data = &ip_rt_max_size,
3140 .maxlen = sizeof(int),
3142 .proc_handler = proc_dointvec,
3145 /* Deprecated. Use gc_min_interval_ms */
3147 .procname = "gc_min_interval",
3148 .data = &ip_rt_gc_min_interval,
3149 .maxlen = sizeof(int),
3151 .proc_handler = proc_dointvec_jiffies,
3154 .procname = "gc_min_interval_ms",
3155 .data = &ip_rt_gc_min_interval,
3156 .maxlen = sizeof(int),
3158 .proc_handler = proc_dointvec_ms_jiffies,
3161 .procname = "gc_timeout",
3162 .data = &ip_rt_gc_timeout,
3163 .maxlen = sizeof(int),
3165 .proc_handler = proc_dointvec_jiffies,
3168 .procname = "gc_interval",
3169 .data = &ip_rt_gc_interval,
3170 .maxlen = sizeof(int),
3172 .proc_handler = proc_dointvec_jiffies,
3175 .procname = "redirect_load",
3176 .data = &ip_rt_redirect_load,
3177 .maxlen = sizeof(int),
3179 .proc_handler = proc_dointvec,
3182 .procname = "redirect_number",
3183 .data = &ip_rt_redirect_number,
3184 .maxlen = sizeof(int),
3186 .proc_handler = proc_dointvec,
3189 .procname = "redirect_silence",
3190 .data = &ip_rt_redirect_silence,
3191 .maxlen = sizeof(int),
3193 .proc_handler = proc_dointvec,
3196 .procname = "error_cost",
3197 .data = &ip_rt_error_cost,
3198 .maxlen = sizeof(int),
3200 .proc_handler = proc_dointvec,
3203 .procname = "error_burst",
3204 .data = &ip_rt_error_burst,
3205 .maxlen = sizeof(int),
3207 .proc_handler = proc_dointvec,
3210 .procname = "gc_elasticity",
3211 .data = &ip_rt_gc_elasticity,
3212 .maxlen = sizeof(int),
3214 .proc_handler = proc_dointvec,
3217 .procname = "mtu_expires",
3218 .data = &ip_rt_mtu_expires,
3219 .maxlen = sizeof(int),
3221 .proc_handler = proc_dointvec_jiffies,
3224 .procname = "min_pmtu",
3225 .data = &ip_rt_min_pmtu,
3226 .maxlen = sizeof(int),
3228 .proc_handler = proc_dointvec,
3231 .procname = "min_adv_mss",
3232 .data = &ip_rt_min_advmss,
3233 .maxlen = sizeof(int),
3235 .proc_handler = proc_dointvec,
3240 static struct ctl_table empty[1];
3242 static struct ctl_table ipv4_skeleton[] =
3244 { .procname = "route",
3245 .mode = 0555, .child = ipv4_route_table},
3246 { .procname = "neigh",
3247 .mode = 0555, .child = empty},
3251 static __net_initdata struct ctl_path ipv4_path[] = {
3252 { .procname = "net", },
3253 { .procname = "ipv4", },
3257 static struct ctl_table ipv4_route_flush_table[] = {
3259 .procname = "flush",
3260 .maxlen = sizeof(int),
3262 .proc_handler = ipv4_sysctl_rtcache_flush,
3267 static __net_initdata struct ctl_path ipv4_route_path[] = {
3268 { .procname = "net", },
3269 { .procname = "ipv4", },
3270 { .procname = "route", },
3274 static __net_init int sysctl_route_net_init(struct net *net)
3276 struct ctl_table *tbl;
3278 tbl = ipv4_route_flush_table;
3279 if (!net_eq(net, &init_net)) {
3280 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3284 tbl[0].extra1 = net;
3286 net->ipv4.route_hdr =
3287 register_net_sysctl_table(net, ipv4_route_path, tbl);
3288 if (net->ipv4.route_hdr == NULL)
3293 if (tbl != ipv4_route_flush_table)
3299 static __net_exit void sysctl_route_net_exit(struct net *net)
3301 struct ctl_table *tbl;
3303 tbl = net->ipv4.route_hdr->ctl_table_arg;
3304 unregister_net_sysctl_table(net->ipv4.route_hdr);
3305 BUG_ON(tbl == ipv4_route_flush_table);
3309 static __net_initdata struct pernet_operations sysctl_route_ops = {
3310 .init = sysctl_route_net_init,
3311 .exit = sysctl_route_net_exit,
3315 static __net_init int rt_genid_init(struct net *net)
3317 get_random_bytes(&net->ipv4.rt_genid,
3318 sizeof(net->ipv4.rt_genid));
3322 static __net_initdata struct pernet_operations rt_genid_ops = {
3323 .init = rt_genid_init,
3327 #ifdef CONFIG_IP_ROUTE_CLASSID
3328 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3329 #endif /* CONFIG_IP_ROUTE_CLASSID */
3331 static __initdata unsigned long rhash_entries;
3332 static int __init set_rhash_entries(char *str)
3336 rhash_entries = simple_strtoul(str, &str, 0);
3339 __setup("rhash_entries=", set_rhash_entries);
3341 int __init ip_rt_init(void)
3345 #ifdef CONFIG_IP_ROUTE_CLASSID
3346 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3348 panic("IP: failed to allocate ip_rt_acct\n");
3351 ipv4_dst_ops.kmem_cachep =
3352 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3353 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3355 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3357 if (dst_entries_init(&ipv4_dst_ops) < 0)
3358 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3360 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3361 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3363 rt_hash_table = (struct rt_hash_bucket *)
3364 alloc_large_system_hash("IP route cache",
3365 sizeof(struct rt_hash_bucket),
3367 (totalram_pages >= 128 * 1024) ?
3372 rhash_entries ? 0 : 512 * 1024);
3373 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3374 rt_hash_lock_init();
3376 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3377 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3382 /* All the timers, started at system startup tend
3383 to synchronize. Perturb it a bit.
3385 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func);
3386 expires_ljiffies = jiffies;
3387 schedule_delayed_work(&expires_work,
3388 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3390 if (ip_rt_proc_init())
3391 printk(KERN_ERR "Unable to create route proc files\n");
3394 xfrm4_init(ip_rt_max_size);
3396 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3398 #ifdef CONFIG_SYSCTL
3399 register_pernet_subsys(&sysctl_route_ops);
3401 register_pernet_subsys(&rt_genid_ops);
3405 #ifdef CONFIG_SYSCTL
3407 * We really need to sanitize the damn ipv4 init order, then all
3408 * this nonsense will go away.
3410 void __init ip_static_sysctl_init(void)
3412 register_sysctl_paths(ipv4_path, ipv4_skeleton);