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>
94 #include <linux/prefetch.h>
96 #include <net/net_namespace.h>
97 #include <net/protocol.h>
99 #include <net/route.h>
100 #include <net/inetpeer.h>
101 #include <net/sock.h>
102 #include <net/ip_fib.h>
105 #include <net/icmp.h>
106 #include <net/xfrm.h>
107 #include <net/netevent.h>
108 #include <net/rtnetlink.h>
110 #include <linux/sysctl.h>
112 #include <net/secure_seq.h>
114 #define RT_FL_TOS(oldflp4) \
115 ((u32)(oldflp4->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
117 #define IP_MAX_MTU 0xFFF0
119 #define RT_GC_TIMEOUT (300*HZ)
121 static int ip_rt_max_size;
122 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
123 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
124 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
125 static int ip_rt_redirect_number __read_mostly = 9;
126 static int ip_rt_redirect_load __read_mostly = HZ / 50;
127 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
128 static int ip_rt_error_cost __read_mostly = HZ;
129 static int ip_rt_error_burst __read_mostly = 5 * HZ;
130 static int ip_rt_gc_elasticity __read_mostly = 8;
131 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
132 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
133 static int ip_rt_min_advmss __read_mostly = 256;
134 static int rt_chain_length_max __read_mostly = 20;
136 static struct delayed_work expires_work;
137 static unsigned long expires_ljiffies;
140 * Interface to generic destination cache.
143 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
144 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
145 static unsigned int ipv4_default_mtu(const struct dst_entry *dst);
146 static void ipv4_dst_destroy(struct dst_entry *dst);
147 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
148 static void ipv4_link_failure(struct sk_buff *skb);
149 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
150 static int rt_garbage_collect(struct dst_ops *ops);
152 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
157 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
159 struct rtable *rt = (struct rtable *) dst;
160 struct inet_peer *peer;
164 rt_bind_peer(rt, rt->rt_dst, 1);
168 u32 *old_p = __DST_METRICS_PTR(old);
169 unsigned long prev, new;
172 if (inet_metrics_new(peer))
173 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
175 new = (unsigned long) p;
176 prev = cmpxchg(&dst->_metrics, old, new);
179 p = __DST_METRICS_PTR(prev);
180 if (prev & DST_METRICS_READ_ONLY)
184 fib_info_put(rt->fi);
192 static struct dst_ops ipv4_dst_ops = {
194 .protocol = cpu_to_be16(ETH_P_IP),
195 .gc = rt_garbage_collect,
196 .check = ipv4_dst_check,
197 .default_advmss = ipv4_default_advmss,
198 .default_mtu = ipv4_default_mtu,
199 .cow_metrics = ipv4_cow_metrics,
200 .destroy = ipv4_dst_destroy,
201 .ifdown = ipv4_dst_ifdown,
202 .negative_advice = ipv4_negative_advice,
203 .link_failure = ipv4_link_failure,
204 .update_pmtu = ip_rt_update_pmtu,
205 .local_out = __ip_local_out,
208 #define ECN_OR_COST(class) TC_PRIO_##class
210 const __u8 ip_tos2prio[16] = {
212 ECN_OR_COST(BESTEFFORT),
214 ECN_OR_COST(BESTEFFORT),
220 ECN_OR_COST(INTERACTIVE),
222 ECN_OR_COST(INTERACTIVE),
223 TC_PRIO_INTERACTIVE_BULK,
224 ECN_OR_COST(INTERACTIVE_BULK),
225 TC_PRIO_INTERACTIVE_BULK,
226 ECN_OR_COST(INTERACTIVE_BULK)
234 /* The locking scheme is rather straight forward:
236 * 1) Read-Copy Update protects the buckets of the central route hash.
237 * 2) Only writers remove entries, and they hold the lock
238 * as they look at rtable reference counts.
239 * 3) Only readers acquire references to rtable entries,
240 * they do so with atomic increments and with the
244 struct rt_hash_bucket {
245 struct rtable __rcu *chain;
248 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
249 defined(CONFIG_PROVE_LOCKING)
251 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
252 * The size of this table is a power of two and depends on the number of CPUS.
253 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
255 #ifdef CONFIG_LOCKDEP
256 # define RT_HASH_LOCK_SZ 256
259 # define RT_HASH_LOCK_SZ 4096
261 # define RT_HASH_LOCK_SZ 2048
263 # define RT_HASH_LOCK_SZ 1024
265 # define RT_HASH_LOCK_SZ 512
267 # define RT_HASH_LOCK_SZ 256
271 static spinlock_t *rt_hash_locks;
272 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
274 static __init void rt_hash_lock_init(void)
278 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
281 panic("IP: failed to allocate rt_hash_locks\n");
283 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
284 spin_lock_init(&rt_hash_locks[i]);
287 # define rt_hash_lock_addr(slot) NULL
289 static inline void rt_hash_lock_init(void)
294 static struct rt_hash_bucket *rt_hash_table __read_mostly;
295 static unsigned rt_hash_mask __read_mostly;
296 static unsigned int rt_hash_log __read_mostly;
298 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
299 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
301 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
304 return jhash_3words((__force u32)daddr, (__force u32)saddr,
309 static inline int rt_genid(struct net *net)
311 return atomic_read(&net->ipv4.rt_genid);
314 #ifdef CONFIG_PROC_FS
315 struct rt_cache_iter_state {
316 struct seq_net_private p;
321 static struct rtable *rt_cache_get_first(struct seq_file *seq)
323 struct rt_cache_iter_state *st = seq->private;
324 struct rtable *r = NULL;
326 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
327 if (!rcu_dereference_raw(rt_hash_table[st->bucket].chain))
330 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
332 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
333 r->rt_genid == st->genid)
335 r = rcu_dereference_bh(r->dst.rt_next);
337 rcu_read_unlock_bh();
342 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
345 struct rt_cache_iter_state *st = seq->private;
347 r = rcu_dereference_bh(r->dst.rt_next);
349 rcu_read_unlock_bh();
351 if (--st->bucket < 0)
353 } while (!rcu_dereference_raw(rt_hash_table[st->bucket].chain));
355 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
360 static struct rtable *rt_cache_get_next(struct seq_file *seq,
363 struct rt_cache_iter_state *st = seq->private;
364 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
365 if (dev_net(r->dst.dev) != seq_file_net(seq))
367 if (r->rt_genid == st->genid)
373 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
375 struct rtable *r = rt_cache_get_first(seq);
378 while (pos && (r = rt_cache_get_next(seq, r)))
380 return pos ? NULL : r;
383 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
385 struct rt_cache_iter_state *st = seq->private;
387 return rt_cache_get_idx(seq, *pos - 1);
388 st->genid = rt_genid(seq_file_net(seq));
389 return SEQ_START_TOKEN;
392 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
396 if (v == SEQ_START_TOKEN)
397 r = rt_cache_get_first(seq);
399 r = rt_cache_get_next(seq, v);
404 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
406 if (v && v != SEQ_START_TOKEN)
407 rcu_read_unlock_bh();
410 static int rt_cache_seq_show(struct seq_file *seq, void *v)
412 if (v == SEQ_START_TOKEN)
413 seq_printf(seq, "%-127s\n",
414 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
415 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
418 struct rtable *r = v;
423 n = dst_get_neighbour(&r->dst);
424 HHUptod = (n && (n->nud_state & NUD_CONNECTED)) ? 1 : 0;
427 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
428 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
429 r->dst.dev ? r->dst.dev->name : "*",
430 (__force u32)r->rt_dst,
431 (__force u32)r->rt_gateway,
432 r->rt_flags, atomic_read(&r->dst.__refcnt),
433 r->dst.__use, 0, (__force u32)r->rt_src,
434 dst_metric_advmss(&r->dst) + 40,
435 dst_metric(&r->dst, RTAX_WINDOW),
436 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
437 dst_metric(&r->dst, RTAX_RTTVAR)),
439 r->dst.hh ? atomic_read(&r->dst.hh->hh_refcnt) : -1,
441 r->rt_spec_dst, &len);
443 seq_printf(seq, "%*s\n", 127 - len, "");
448 static const struct seq_operations rt_cache_seq_ops = {
449 .start = rt_cache_seq_start,
450 .next = rt_cache_seq_next,
451 .stop = rt_cache_seq_stop,
452 .show = rt_cache_seq_show,
455 static int rt_cache_seq_open(struct inode *inode, struct file *file)
457 return seq_open_net(inode, file, &rt_cache_seq_ops,
458 sizeof(struct rt_cache_iter_state));
461 static const struct file_operations rt_cache_seq_fops = {
462 .owner = THIS_MODULE,
463 .open = rt_cache_seq_open,
466 .release = seq_release_net,
470 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
475 return SEQ_START_TOKEN;
477 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
478 if (!cpu_possible(cpu))
481 return &per_cpu(rt_cache_stat, cpu);
486 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
490 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
491 if (!cpu_possible(cpu))
494 return &per_cpu(rt_cache_stat, cpu);
500 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
505 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
507 struct rt_cache_stat *st = v;
509 if (v == SEQ_START_TOKEN) {
510 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");
514 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
515 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
516 dst_entries_get_slow(&ipv4_dst_ops),
539 static const struct seq_operations rt_cpu_seq_ops = {
540 .start = rt_cpu_seq_start,
541 .next = rt_cpu_seq_next,
542 .stop = rt_cpu_seq_stop,
543 .show = rt_cpu_seq_show,
547 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
549 return seq_open(file, &rt_cpu_seq_ops);
552 static const struct file_operations rt_cpu_seq_fops = {
553 .owner = THIS_MODULE,
554 .open = rt_cpu_seq_open,
557 .release = seq_release,
560 #ifdef CONFIG_IP_ROUTE_CLASSID
561 static int rt_acct_proc_show(struct seq_file *m, void *v)
563 struct ip_rt_acct *dst, *src;
566 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
570 for_each_possible_cpu(i) {
571 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
572 for (j = 0; j < 256; j++) {
573 dst[j].o_bytes += src[j].o_bytes;
574 dst[j].o_packets += src[j].o_packets;
575 dst[j].i_bytes += src[j].i_bytes;
576 dst[j].i_packets += src[j].i_packets;
580 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
585 static int rt_acct_proc_open(struct inode *inode, struct file *file)
587 return single_open(file, rt_acct_proc_show, NULL);
590 static const struct file_operations rt_acct_proc_fops = {
591 .owner = THIS_MODULE,
592 .open = rt_acct_proc_open,
595 .release = single_release,
599 static int __net_init ip_rt_do_proc_init(struct net *net)
601 struct proc_dir_entry *pde;
603 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
608 pde = proc_create("rt_cache", S_IRUGO,
609 net->proc_net_stat, &rt_cpu_seq_fops);
613 #ifdef CONFIG_IP_ROUTE_CLASSID
614 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
620 #ifdef CONFIG_IP_ROUTE_CLASSID
622 remove_proc_entry("rt_cache", net->proc_net_stat);
625 remove_proc_entry("rt_cache", net->proc_net);
630 static void __net_exit ip_rt_do_proc_exit(struct net *net)
632 remove_proc_entry("rt_cache", net->proc_net_stat);
633 remove_proc_entry("rt_cache", net->proc_net);
634 #ifdef CONFIG_IP_ROUTE_CLASSID
635 remove_proc_entry("rt_acct", net->proc_net);
639 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
640 .init = ip_rt_do_proc_init,
641 .exit = ip_rt_do_proc_exit,
644 static int __init ip_rt_proc_init(void)
646 return register_pernet_subsys(&ip_rt_proc_ops);
650 static inline int ip_rt_proc_init(void)
654 #endif /* CONFIG_PROC_FS */
656 static inline void rt_free(struct rtable *rt)
658 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
661 static inline void rt_drop(struct rtable *rt)
664 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
667 static inline int rt_fast_clean(struct rtable *rth)
669 /* Kill broadcast/multicast entries very aggresively, if they
670 collide in hash table with more useful entries */
671 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
672 rt_is_input_route(rth) && rth->dst.rt_next;
675 static inline int rt_valuable(struct rtable *rth)
677 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
678 (rth->peer && rth->peer->pmtu_expires);
681 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
686 if (atomic_read(&rth->dst.__refcnt))
689 age = jiffies - rth->dst.lastuse;
690 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
691 (age <= tmo2 && rt_valuable(rth)))
697 /* Bits of score are:
699 * 30: not quite useless
700 * 29..0: usage counter
702 static inline u32 rt_score(struct rtable *rt)
704 u32 score = jiffies - rt->dst.lastuse;
706 score = ~score & ~(3<<30);
711 if (rt_is_output_route(rt) ||
712 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
718 static inline bool rt_caching(const struct net *net)
720 return net->ipv4.current_rt_cache_rebuild_count <=
721 net->ipv4.sysctl_rt_cache_rebuild_count;
724 static inline bool compare_hash_inputs(const struct rtable *rt1,
725 const struct rtable *rt2)
727 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
728 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
729 (rt1->rt_route_iif ^ rt2->rt_route_iif)) == 0);
732 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
734 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
735 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
736 (rt1->rt_mark ^ rt2->rt_mark) |
737 (rt1->rt_key_tos ^ rt2->rt_key_tos) |
738 (rt1->rt_route_iif ^ rt2->rt_route_iif) |
739 (rt1->rt_oif ^ rt2->rt_oif)) == 0;
742 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
744 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
747 static inline int rt_is_expired(struct rtable *rth)
749 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
753 * Perform a full scan of hash table and free all entries.
754 * Can be called by a softirq or a process.
755 * In the later case, we want to be reschedule if necessary
757 static void rt_do_flush(struct net *net, int process_context)
760 struct rtable *rth, *next;
762 for (i = 0; i <= rt_hash_mask; i++) {
763 struct rtable __rcu **pprev;
766 if (process_context && need_resched())
768 rth = rcu_dereference_raw(rt_hash_table[i].chain);
772 spin_lock_bh(rt_hash_lock_addr(i));
775 pprev = &rt_hash_table[i].chain;
776 rth = rcu_dereference_protected(*pprev,
777 lockdep_is_held(rt_hash_lock_addr(i)));
780 next = rcu_dereference_protected(rth->dst.rt_next,
781 lockdep_is_held(rt_hash_lock_addr(i)));
784 net_eq(dev_net(rth->dst.dev), net)) {
785 rcu_assign_pointer(*pprev, next);
786 rcu_assign_pointer(rth->dst.rt_next, list);
789 pprev = &rth->dst.rt_next;
794 spin_unlock_bh(rt_hash_lock_addr(i));
796 for (; list; list = next) {
797 next = rcu_dereference_protected(list->dst.rt_next, 1);
804 * While freeing expired entries, we compute average chain length
805 * and standard deviation, using fixed-point arithmetic.
806 * This to have an estimation of rt_chain_length_max
807 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
808 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
812 #define ONE (1UL << FRACT_BITS)
815 * Given a hash chain and an item in this hash chain,
816 * find if a previous entry has the same hash_inputs
817 * (but differs on tos, mark or oif)
818 * Returns 0 if an alias is found.
819 * Returns ONE if rth has no alias before itself.
821 static int has_noalias(const struct rtable *head, const struct rtable *rth)
823 const struct rtable *aux = head;
826 if (compare_hash_inputs(aux, rth))
828 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
833 static void rt_check_expire(void)
835 static unsigned int rover;
836 unsigned int i = rover, goal;
838 struct rtable __rcu **rthp;
839 unsigned long samples = 0;
840 unsigned long sum = 0, sum2 = 0;
844 delta = jiffies - expires_ljiffies;
845 expires_ljiffies = jiffies;
846 mult = ((u64)delta) << rt_hash_log;
847 if (ip_rt_gc_timeout > 1)
848 do_div(mult, ip_rt_gc_timeout);
849 goal = (unsigned int)mult;
850 if (goal > rt_hash_mask)
851 goal = rt_hash_mask + 1;
852 for (; goal > 0; goal--) {
853 unsigned long tmo = ip_rt_gc_timeout;
854 unsigned long length;
856 i = (i + 1) & rt_hash_mask;
857 rthp = &rt_hash_table[i].chain;
864 if (rcu_dereference_raw(*rthp) == NULL)
867 spin_lock_bh(rt_hash_lock_addr(i));
868 while ((rth = rcu_dereference_protected(*rthp,
869 lockdep_is_held(rt_hash_lock_addr(i)))) != NULL) {
870 prefetch(rth->dst.rt_next);
871 if (rt_is_expired(rth)) {
872 *rthp = rth->dst.rt_next;
876 if (rth->dst.expires) {
877 /* Entry is expired even if it is in use */
878 if (time_before_eq(jiffies, rth->dst.expires)) {
881 rthp = &rth->dst.rt_next;
883 * We only count entries on
884 * a chain with equal hash inputs once
885 * so that entries for different QOS
886 * levels, and other non-hash input
887 * attributes don't unfairly skew
888 * the length computation
890 length += has_noalias(rt_hash_table[i].chain, rth);
893 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout))
896 /* Cleanup aged off entries. */
897 *rthp = rth->dst.rt_next;
900 spin_unlock_bh(rt_hash_lock_addr(i));
902 sum2 += length*length;
905 unsigned long avg = sum / samples;
906 unsigned long sd = int_sqrt(sum2 / samples - avg*avg);
907 rt_chain_length_max = max_t(unsigned long,
909 (avg + 4*sd) >> FRACT_BITS);
915 * rt_worker_func() is run in process context.
916 * we call rt_check_expire() to scan part of the hash table
918 static void rt_worker_func(struct work_struct *work)
921 schedule_delayed_work(&expires_work, ip_rt_gc_interval);
925 * Perturbation of rt_genid by a small quantity [1..256]
926 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
927 * many times (2^24) without giving recent rt_genid.
928 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
930 static void rt_cache_invalidate(struct net *net)
932 unsigned char shuffle;
934 get_random_bytes(&shuffle, sizeof(shuffle));
935 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
939 * delay < 0 : invalidate cache (fast : entries will be deleted later)
940 * delay >= 0 : invalidate & flush cache (can be long)
942 void rt_cache_flush(struct net *net, int delay)
944 rt_cache_invalidate(net);
946 rt_do_flush(net, !in_softirq());
949 /* Flush previous cache invalidated entries from the cache */
950 void rt_cache_flush_batch(struct net *net)
952 rt_do_flush(net, !in_softirq());
955 static void rt_emergency_hash_rebuild(struct net *net)
958 printk(KERN_WARNING "Route hash chain too long!\n");
959 rt_cache_invalidate(net);
963 Short description of GC goals.
965 We want to build algorithm, which will keep routing cache
966 at some equilibrium point, when number of aged off entries
967 is kept approximately equal to newly generated ones.
969 Current expiration strength is variable "expire".
970 We try to adjust it dynamically, so that if networking
971 is idle expires is large enough to keep enough of warm entries,
972 and when load increases it reduces to limit cache size.
975 static int rt_garbage_collect(struct dst_ops *ops)
977 static unsigned long expire = RT_GC_TIMEOUT;
978 static unsigned long last_gc;
980 static int equilibrium;
982 struct rtable __rcu **rthp;
983 unsigned long now = jiffies;
985 int entries = dst_entries_get_fast(&ipv4_dst_ops);
988 * Garbage collection is pretty expensive,
989 * do not make it too frequently.
992 RT_CACHE_STAT_INC(gc_total);
994 if (now - last_gc < ip_rt_gc_min_interval &&
995 entries < ip_rt_max_size) {
996 RT_CACHE_STAT_INC(gc_ignored);
1000 entries = dst_entries_get_slow(&ipv4_dst_ops);
1001 /* Calculate number of entries, which we want to expire now. */
1002 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
1004 if (equilibrium < ipv4_dst_ops.gc_thresh)
1005 equilibrium = ipv4_dst_ops.gc_thresh;
1006 goal = entries - equilibrium;
1008 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
1009 goal = entries - equilibrium;
1012 /* We are in dangerous area. Try to reduce cache really
1015 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
1016 equilibrium = entries - goal;
1019 if (now - last_gc >= ip_rt_gc_min_interval)
1023 equilibrium += goal;
1030 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
1031 unsigned long tmo = expire;
1033 k = (k + 1) & rt_hash_mask;
1034 rthp = &rt_hash_table[k].chain;
1035 spin_lock_bh(rt_hash_lock_addr(k));
1036 while ((rth = rcu_dereference_protected(*rthp,
1037 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
1038 if (!rt_is_expired(rth) &&
1039 !rt_may_expire(rth, tmo, expire)) {
1041 rthp = &rth->dst.rt_next;
1044 *rthp = rth->dst.rt_next;
1048 spin_unlock_bh(rt_hash_lock_addr(k));
1057 /* Goal is not achieved. We stop process if:
1059 - if expire reduced to zero. Otherwise, expire is halfed.
1060 - if table is not full.
1061 - if we are called from interrupt.
1062 - jiffies check is just fallback/debug loop breaker.
1063 We will not spin here for long time in any case.
1066 RT_CACHE_STAT_INC(gc_goal_miss);
1073 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
1075 } while (!in_softirq() && time_before_eq(jiffies, now));
1077 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
1079 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
1081 if (net_ratelimit())
1082 printk(KERN_WARNING "dst cache overflow\n");
1083 RT_CACHE_STAT_INC(gc_dst_overflow);
1087 expire += ip_rt_gc_min_interval;
1088 if (expire > ip_rt_gc_timeout ||
1089 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
1090 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
1091 expire = ip_rt_gc_timeout;
1096 * Returns number of entries in a hash chain that have different hash_inputs
1098 static int slow_chain_length(const struct rtable *head)
1101 const struct rtable *rth = head;
1104 length += has_noalias(head, rth);
1105 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1107 return length >> FRACT_BITS;
1110 static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,
1111 struct sk_buff *skb, int ifindex)
1113 struct rtable *rth, *cand;
1114 struct rtable __rcu **rthp, **candp;
1118 int attempts = !in_softirq();
1122 min_score = ~(u32)0;
1127 if (!rt_caching(dev_net(rt->dst.dev))) {
1129 * If we're not caching, just tell the caller we
1130 * were successful and don't touch the route. The
1131 * caller hold the sole reference to the cache entry, and
1132 * it will be released when the caller is done with it.
1133 * If we drop it here, the callers have no way to resolve routes
1134 * when we're not caching. Instead, just point *rp at rt, so
1135 * the caller gets a single use out of the route
1136 * Note that we do rt_free on this new route entry, so that
1137 * once its refcount hits zero, we are still able to reap it
1139 * Note: To avoid expensive rcu stuff for this uncached dst,
1140 * we set DST_NOCACHE so that dst_release() can free dst without
1141 * waiting a grace period.
1144 rt->dst.flags |= DST_NOCACHE;
1145 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1146 int err = arp_bind_neighbour(&rt->dst);
1148 if (net_ratelimit())
1150 "Neighbour table failure & not caching routes.\n");
1152 return ERR_PTR(err);
1159 rthp = &rt_hash_table[hash].chain;
1161 spin_lock_bh(rt_hash_lock_addr(hash));
1162 while ((rth = rcu_dereference_protected(*rthp,
1163 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1164 if (rt_is_expired(rth)) {
1165 *rthp = rth->dst.rt_next;
1169 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1171 *rthp = rth->dst.rt_next;
1173 * Since lookup is lockfree, the deletion
1174 * must be visible to another weakly ordered CPU before
1175 * the insertion at the start of the hash chain.
1177 rcu_assign_pointer(rth->dst.rt_next,
1178 rt_hash_table[hash].chain);
1180 * Since lookup is lockfree, the update writes
1181 * must be ordered for consistency on SMP.
1183 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1185 dst_use(&rth->dst, now);
1186 spin_unlock_bh(rt_hash_lock_addr(hash));
1190 skb_dst_set(skb, &rth->dst);
1194 if (!atomic_read(&rth->dst.__refcnt)) {
1195 u32 score = rt_score(rth);
1197 if (score <= min_score) {
1206 rthp = &rth->dst.rt_next;
1210 /* ip_rt_gc_elasticity used to be average length of chain
1211 * length, when exceeded gc becomes really aggressive.
1213 * The second limit is less certain. At the moment it allows
1214 * only 2 entries per bucket. We will see.
1216 if (chain_length > ip_rt_gc_elasticity) {
1217 *candp = cand->dst.rt_next;
1221 if (chain_length > rt_chain_length_max &&
1222 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1223 struct net *net = dev_net(rt->dst.dev);
1224 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1225 if (!rt_caching(net)) {
1226 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1227 rt->dst.dev->name, num);
1229 rt_emergency_hash_rebuild(net);
1230 spin_unlock_bh(rt_hash_lock_addr(hash));
1232 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1233 ifindex, rt_genid(net));
1238 /* Try to bind route to arp only if it is output
1239 route or unicast forwarding path.
1241 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1242 int err = arp_bind_neighbour(&rt->dst);
1244 spin_unlock_bh(rt_hash_lock_addr(hash));
1246 if (err != -ENOBUFS) {
1248 return ERR_PTR(err);
1251 /* Neighbour tables are full and nothing
1252 can be released. Try to shrink route cache,
1253 it is most likely it holds some neighbour records.
1255 if (attempts-- > 0) {
1256 int saved_elasticity = ip_rt_gc_elasticity;
1257 int saved_int = ip_rt_gc_min_interval;
1258 ip_rt_gc_elasticity = 1;
1259 ip_rt_gc_min_interval = 0;
1260 rt_garbage_collect(&ipv4_dst_ops);
1261 ip_rt_gc_min_interval = saved_int;
1262 ip_rt_gc_elasticity = saved_elasticity;
1266 if (net_ratelimit())
1267 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1269 return ERR_PTR(-ENOBUFS);
1273 rt->dst.rt_next = rt_hash_table[hash].chain;
1276 * Since lookup is lockfree, we must make sure
1277 * previous writes to rt are committed to memory
1278 * before making rt visible to other CPUS.
1280 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1282 spin_unlock_bh(rt_hash_lock_addr(hash));
1286 skb_dst_set(skb, &rt->dst);
1290 static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1292 static u32 rt_peer_genid(void)
1294 return atomic_read(&__rt_peer_genid);
1297 void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
1299 struct inet_peer *peer;
1301 peer = inet_getpeer_v4(daddr, create);
1303 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1306 rt->rt_peer_genid = rt_peer_genid();
1310 * Peer allocation may fail only in serious out-of-memory conditions. However
1311 * we still can generate some output.
1312 * Random ID selection looks a bit dangerous because we have no chances to
1313 * select ID being unique in a reasonable period of time.
1314 * But broken packet identifier may be better than no packet at all.
1316 static void ip_select_fb_ident(struct iphdr *iph)
1318 static DEFINE_SPINLOCK(ip_fb_id_lock);
1319 static u32 ip_fallback_id;
1322 spin_lock_bh(&ip_fb_id_lock);
1323 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1324 iph->id = htons(salt & 0xFFFF);
1325 ip_fallback_id = salt;
1326 spin_unlock_bh(&ip_fb_id_lock);
1329 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1331 struct rtable *rt = (struct rtable *) dst;
1334 if (rt->peer == NULL)
1335 rt_bind_peer(rt, rt->rt_dst, 1);
1337 /* If peer is attached to destination, it is never detached,
1338 so that we need not to grab a lock to dereference it.
1341 iph->id = htons(inet_getid(rt->peer, more));
1345 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1346 __builtin_return_address(0));
1348 ip_select_fb_ident(iph);
1350 EXPORT_SYMBOL(__ip_select_ident);
1352 static void rt_del(unsigned hash, struct rtable *rt)
1354 struct rtable __rcu **rthp;
1357 rthp = &rt_hash_table[hash].chain;
1358 spin_lock_bh(rt_hash_lock_addr(hash));
1360 while ((aux = rcu_dereference_protected(*rthp,
1361 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1362 if (aux == rt || rt_is_expired(aux)) {
1363 *rthp = aux->dst.rt_next;
1367 rthp = &aux->dst.rt_next;
1369 spin_unlock_bh(rt_hash_lock_addr(hash));
1372 static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1374 struct rtable *rt = (struct rtable *) dst;
1375 __be32 orig_gw = rt->rt_gateway;
1376 struct neighbour *n, *old_n;
1377 struct hh_cache *old_hh;
1379 dst_confirm(&rt->dst);
1381 rt->rt_gateway = peer->redirect_learned.a4;
1382 n = __arp_bind_neighbour(&rt->dst, rt->rt_gateway);
1385 old_hh = xchg(&rt->dst.hh, NULL);
1387 hh_cache_put(old_hh);
1388 old_n = xchg(&rt->dst._neighbour, n);
1390 neigh_release(old_n);
1391 if (!n || !(n->nud_state & NUD_VALID)) {
1393 neigh_event_send(n, NULL);
1394 rt->rt_gateway = orig_gw;
1397 rt->rt_flags |= RTCF_REDIRECTED;
1398 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
1403 /* called in rcu_read_lock() section */
1404 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1405 __be32 saddr, struct net_device *dev)
1408 struct in_device *in_dev = __in_dev_get_rcu(dev);
1409 __be32 skeys[2] = { saddr, 0 };
1410 int ikeys[2] = { dev->ifindex, 0 };
1411 struct inet_peer *peer;
1418 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1419 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1420 ipv4_is_zeronet(new_gw))
1421 goto reject_redirect;
1423 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1424 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1425 goto reject_redirect;
1426 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1427 goto reject_redirect;
1429 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1430 goto reject_redirect;
1433 for (s = 0; s < 2; s++) {
1434 for (i = 0; i < 2; i++) {
1436 struct rtable __rcu **rthp;
1439 hash = rt_hash(daddr, skeys[s], ikeys[i], rt_genid(net));
1441 rthp = &rt_hash_table[hash].chain;
1443 while ((rt = rcu_dereference(*rthp)) != NULL) {
1444 rthp = &rt->dst.rt_next;
1446 if (rt->rt_key_dst != daddr ||
1447 rt->rt_key_src != skeys[s] ||
1448 rt->rt_oif != ikeys[i] ||
1449 rt_is_input_route(rt) ||
1450 rt_is_expired(rt) ||
1451 !net_eq(dev_net(rt->dst.dev), net) ||
1453 rt->dst.dev != dev ||
1454 rt->rt_gateway != old_gw)
1458 rt_bind_peer(rt, rt->rt_dst, 1);
1462 if (peer->redirect_learned.a4 != new_gw) {
1463 peer->redirect_learned.a4 = new_gw;
1464 atomic_inc(&__rt_peer_genid);
1466 check_peer_redir(&rt->dst, peer);
1474 #ifdef CONFIG_IP_ROUTE_VERBOSE
1475 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1476 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1477 " Advised path = %pI4 -> %pI4\n",
1478 &old_gw, dev->name, &new_gw,
1484 static bool peer_pmtu_expired(struct inet_peer *peer)
1486 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1489 time_after_eq(jiffies, orig) &&
1490 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1493 static bool peer_pmtu_cleaned(struct inet_peer *peer)
1495 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1498 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1501 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1503 struct rtable *rt = (struct rtable *)dst;
1504 struct dst_entry *ret = dst;
1507 if (dst->obsolete > 0) {
1510 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1511 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1513 rt_genid(dev_net(dst->dev)));
1516 } else if (rt->peer && peer_pmtu_expired(rt->peer)) {
1517 dst_metric_set(dst, RTAX_MTU, rt->peer->pmtu_orig);
1525 * 1. The first ip_rt_redirect_number redirects are sent
1526 * with exponential backoff, then we stop sending them at all,
1527 * assuming that the host ignores our redirects.
1528 * 2. If we did not see packets requiring redirects
1529 * during ip_rt_redirect_silence, we assume that the host
1530 * forgot redirected route and start to send redirects again.
1532 * This algorithm is much cheaper and more intelligent than dumb load limiting
1535 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1536 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1539 void ip_rt_send_redirect(struct sk_buff *skb)
1541 struct rtable *rt = skb_rtable(skb);
1542 struct in_device *in_dev;
1543 struct inet_peer *peer;
1547 in_dev = __in_dev_get_rcu(rt->dst.dev);
1548 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1552 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1556 rt_bind_peer(rt, rt->rt_dst, 1);
1559 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1563 /* No redirected packets during ip_rt_redirect_silence;
1564 * reset the algorithm.
1566 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1567 peer->rate_tokens = 0;
1569 /* Too many ignored redirects; do not send anything
1570 * set dst.rate_last to the last seen redirected packet.
1572 if (peer->rate_tokens >= ip_rt_redirect_number) {
1573 peer->rate_last = jiffies;
1577 /* Check for load limit; set rate_last to the latest sent
1580 if (peer->rate_tokens == 0 ||
1583 (ip_rt_redirect_load << peer->rate_tokens)))) {
1584 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1585 peer->rate_last = jiffies;
1586 ++peer->rate_tokens;
1587 #ifdef CONFIG_IP_ROUTE_VERBOSE
1589 peer->rate_tokens == ip_rt_redirect_number &&
1591 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1592 &ip_hdr(skb)->saddr, rt->rt_iif,
1593 &rt->rt_dst, &rt->rt_gateway);
1598 static int ip_error(struct sk_buff *skb)
1600 struct rtable *rt = skb_rtable(skb);
1601 struct inet_peer *peer;
1606 switch (rt->dst.error) {
1611 code = ICMP_HOST_UNREACH;
1614 code = ICMP_NET_UNREACH;
1615 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1616 IPSTATS_MIB_INNOROUTES);
1619 code = ICMP_PKT_FILTERED;
1624 rt_bind_peer(rt, rt->rt_dst, 1);
1630 peer->rate_tokens += now - peer->rate_last;
1631 if (peer->rate_tokens > ip_rt_error_burst)
1632 peer->rate_tokens = ip_rt_error_burst;
1633 peer->rate_last = now;
1634 if (peer->rate_tokens >= ip_rt_error_cost)
1635 peer->rate_tokens -= ip_rt_error_cost;
1640 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1642 out: kfree_skb(skb);
1647 * The last two values are not from the RFC but
1648 * are needed for AMPRnet AX.25 paths.
1651 static const unsigned short mtu_plateau[] =
1652 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1654 static inline unsigned short guess_mtu(unsigned short old_mtu)
1658 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1659 if (old_mtu > mtu_plateau[i])
1660 return mtu_plateau[i];
1664 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
1665 unsigned short new_mtu,
1666 struct net_device *dev)
1668 unsigned short old_mtu = ntohs(iph->tot_len);
1669 unsigned short est_mtu = 0;
1670 struct inet_peer *peer;
1672 peer = inet_getpeer_v4(iph->daddr, 1);
1674 unsigned short mtu = new_mtu;
1676 if (new_mtu < 68 || new_mtu >= old_mtu) {
1677 /* BSD 4.2 derived systems incorrectly adjust
1678 * tot_len by the IP header length, and report
1679 * a zero MTU in the ICMP message.
1682 old_mtu >= 68 + (iph->ihl << 2))
1683 old_mtu -= iph->ihl << 2;
1684 mtu = guess_mtu(old_mtu);
1687 if (mtu < ip_rt_min_pmtu)
1688 mtu = ip_rt_min_pmtu;
1689 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1690 unsigned long pmtu_expires;
1692 pmtu_expires = jiffies + ip_rt_mtu_expires;
1697 peer->pmtu_learned = mtu;
1698 peer->pmtu_expires = pmtu_expires;
1703 atomic_inc(&__rt_peer_genid);
1705 return est_mtu ? : new_mtu;
1708 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1710 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires);
1714 if (time_before(jiffies, expires)) {
1715 u32 orig_dst_mtu = dst_mtu(dst);
1716 if (peer->pmtu_learned < orig_dst_mtu) {
1717 if (!peer->pmtu_orig)
1718 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1719 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1721 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1722 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1725 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1727 struct rtable *rt = (struct rtable *) dst;
1728 struct inet_peer *peer;
1733 rt_bind_peer(rt, rt->rt_dst, 1);
1736 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires);
1738 if (mtu < ip_rt_min_pmtu)
1739 mtu = ip_rt_min_pmtu;
1740 if (!pmtu_expires || mtu < peer->pmtu_learned) {
1742 pmtu_expires = jiffies + ip_rt_mtu_expires;
1746 peer->pmtu_learned = mtu;
1747 peer->pmtu_expires = pmtu_expires;
1749 atomic_inc(&__rt_peer_genid);
1750 rt->rt_peer_genid = rt_peer_genid();
1752 check_peer_pmtu(dst, peer);
1756 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1758 struct rtable *rt = (struct rtable *) dst;
1760 if (rt_is_expired(rt))
1762 if (rt->rt_peer_genid != rt_peer_genid()) {
1763 struct inet_peer *peer;
1766 rt_bind_peer(rt, rt->rt_dst, 0);
1770 check_peer_pmtu(dst, peer);
1772 if (peer->redirect_learned.a4 &&
1773 peer->redirect_learned.a4 != rt->rt_gateway) {
1774 if (check_peer_redir(dst, peer))
1779 rt->rt_peer_genid = rt_peer_genid();
1784 static void ipv4_dst_destroy(struct dst_entry *dst)
1786 struct rtable *rt = (struct rtable *) dst;
1787 struct inet_peer *peer = rt->peer;
1790 fib_info_put(rt->fi);
1800 static void ipv4_link_failure(struct sk_buff *skb)
1804 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1806 rt = skb_rtable(skb);
1807 if (rt && rt->peer && peer_pmtu_cleaned(rt->peer))
1808 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1811 static int ip_rt_bug(struct sk_buff *skb)
1813 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1814 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1815 skb->dev ? skb->dev->name : "?");
1822 We do not cache source address of outgoing interface,
1823 because it is used only by IP RR, TS and SRR options,
1824 so that it out of fast path.
1826 BTW remember: "addr" is allowed to be not aligned
1830 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1834 if (rt_is_output_route(rt))
1835 src = ip_hdr(skb)->saddr;
1837 struct fib_result res;
1843 memset(&fl4, 0, sizeof(fl4));
1844 fl4.daddr = iph->daddr;
1845 fl4.saddr = iph->saddr;
1846 fl4.flowi4_tos = RT_TOS(iph->tos);
1847 fl4.flowi4_oif = rt->dst.dev->ifindex;
1848 fl4.flowi4_iif = skb->dev->ifindex;
1849 fl4.flowi4_mark = skb->mark;
1852 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1853 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1855 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1859 memcpy(addr, &src, 4);
1862 #ifdef CONFIG_IP_ROUTE_CLASSID
1863 static void set_class_tag(struct rtable *rt, u32 tag)
1865 if (!(rt->dst.tclassid & 0xFFFF))
1866 rt->dst.tclassid |= tag & 0xFFFF;
1867 if (!(rt->dst.tclassid & 0xFFFF0000))
1868 rt->dst.tclassid |= tag & 0xFFFF0000;
1872 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1874 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1877 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1879 if (advmss > 65535 - 40)
1880 advmss = 65535 - 40;
1885 static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
1887 unsigned int mtu = dst->dev->mtu;
1889 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1890 const struct rtable *rt = (const struct rtable *) dst;
1892 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1896 if (mtu > IP_MAX_MTU)
1902 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1903 struct fib_info *fi)
1905 struct inet_peer *peer;
1908 /* If a peer entry exists for this destination, we must hook
1909 * it up in order to get at cached metrics.
1911 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1914 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1916 rt->rt_peer_genid = rt_peer_genid();
1917 if (inet_metrics_new(peer))
1918 memcpy(peer->metrics, fi->fib_metrics,
1919 sizeof(u32) * RTAX_MAX);
1920 dst_init_metrics(&rt->dst, peer->metrics, false);
1922 check_peer_pmtu(&rt->dst, peer);
1923 if (peer->redirect_learned.a4 &&
1924 peer->redirect_learned.a4 != rt->rt_gateway) {
1925 rt->rt_gateway = peer->redirect_learned.a4;
1926 rt->rt_flags |= RTCF_REDIRECTED;
1929 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1931 atomic_inc(&fi->fib_clntref);
1933 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1937 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1938 const struct fib_result *res,
1939 struct fib_info *fi, u16 type, u32 itag)
1941 struct dst_entry *dst = &rt->dst;
1944 if (FIB_RES_GW(*res) &&
1945 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1946 rt->rt_gateway = FIB_RES_GW(*res);
1947 rt_init_metrics(rt, fl4, fi);
1948 #ifdef CONFIG_IP_ROUTE_CLASSID
1949 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1953 if (dst_mtu(dst) > IP_MAX_MTU)
1954 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1955 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1956 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1958 #ifdef CONFIG_IP_ROUTE_CLASSID
1959 #ifdef CONFIG_IP_MULTIPLE_TABLES
1960 set_class_tag(rt, fib_rules_tclass(res));
1962 set_class_tag(rt, itag);
1966 static struct rtable *rt_dst_alloc(struct net_device *dev,
1967 bool nopolicy, bool noxfrm)
1969 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
1971 (nopolicy ? DST_NOPOLICY : 0) |
1972 (noxfrm ? DST_NOXFRM : 0));
1975 /* called in rcu_read_lock() section */
1976 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1977 u8 tos, struct net_device *dev, int our)
1982 struct in_device *in_dev = __in_dev_get_rcu(dev);
1986 /* Primary sanity checks. */
1991 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1992 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1995 if (ipv4_is_zeronet(saddr)) {
1996 if (!ipv4_is_local_multicast(daddr))
1998 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2000 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2005 rth = rt_dst_alloc(init_net.loopback_dev,
2006 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2010 #ifdef CONFIG_IP_ROUTE_CLASSID
2011 rth->dst.tclassid = itag;
2013 rth->dst.output = ip_rt_bug;
2015 rth->rt_key_dst = daddr;
2016 rth->rt_key_src = saddr;
2017 rth->rt_genid = rt_genid(dev_net(dev));
2018 rth->rt_flags = RTCF_MULTICAST;
2019 rth->rt_type = RTN_MULTICAST;
2020 rth->rt_key_tos = tos;
2021 rth->rt_dst = daddr;
2022 rth->rt_src = saddr;
2023 rth->rt_route_iif = dev->ifindex;
2024 rth->rt_iif = dev->ifindex;
2026 rth->rt_mark = skb->mark;
2027 rth->rt_gateway = daddr;
2028 rth->rt_spec_dst= spec_dst;
2029 rth->rt_peer_genid = 0;
2033 rth->dst.input= ip_local_deliver;
2034 rth->rt_flags |= RTCF_LOCAL;
2037 #ifdef CONFIG_IP_MROUTE
2038 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
2039 rth->dst.input = ip_mr_input;
2041 RT_CACHE_STAT_INC(in_slow_mc);
2043 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
2044 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
2045 return IS_ERR(rth) ? PTR_ERR(rth) : 0;
2056 static void ip_handle_martian_source(struct net_device *dev,
2057 struct in_device *in_dev,
2058 struct sk_buff *skb,
2062 RT_CACHE_STAT_INC(in_martian_src);
2063 #ifdef CONFIG_IP_ROUTE_VERBOSE
2064 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
2066 * RFC1812 recommendation, if source is martian,
2067 * the only hint is MAC header.
2069 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
2070 &daddr, &saddr, dev->name);
2071 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
2073 const unsigned char *p = skb_mac_header(skb);
2074 printk(KERN_WARNING "ll header: ");
2075 for (i = 0; i < dev->hard_header_len; i++, p++) {
2077 if (i < (dev->hard_header_len - 1))
2086 /* called in rcu_read_lock() section */
2087 static int __mkroute_input(struct sk_buff *skb,
2088 const struct fib_result *res,
2089 struct in_device *in_dev,
2090 __be32 daddr, __be32 saddr, u32 tos,
2091 struct rtable **result)
2095 struct in_device *out_dev;
2096 unsigned int flags = 0;
2100 /* get a working reference to the output device */
2101 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
2102 if (out_dev == NULL) {
2103 if (net_ratelimit())
2104 printk(KERN_CRIT "Bug in ip_route_input" \
2105 "_slow(). Please, report\n");
2110 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
2111 in_dev->dev, &spec_dst, &itag);
2113 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2120 flags |= RTCF_DIRECTSRC;
2122 if (out_dev == in_dev && err &&
2123 (IN_DEV_SHARED_MEDIA(out_dev) ||
2124 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2125 flags |= RTCF_DOREDIRECT;
2127 if (skb->protocol != htons(ETH_P_IP)) {
2128 /* Not IP (i.e. ARP). Do not create route, if it is
2129 * invalid for proxy arp. DNAT routes are always valid.
2131 * Proxy arp feature have been extended to allow, ARP
2132 * replies back to the same interface, to support
2133 * Private VLAN switch technologies. See arp.c.
2135 if (out_dev == in_dev &&
2136 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2142 rth = rt_dst_alloc(out_dev->dev,
2143 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2144 IN_DEV_CONF_GET(out_dev, NOXFRM));
2150 rth->rt_key_dst = daddr;
2151 rth->rt_key_src = saddr;
2152 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2153 rth->rt_flags = flags;
2154 rth->rt_type = res->type;
2155 rth->rt_key_tos = tos;
2156 rth->rt_dst = daddr;
2157 rth->rt_src = saddr;
2158 rth->rt_route_iif = in_dev->dev->ifindex;
2159 rth->rt_iif = in_dev->dev->ifindex;
2161 rth->rt_mark = skb->mark;
2162 rth->rt_gateway = daddr;
2163 rth->rt_spec_dst= spec_dst;
2164 rth->rt_peer_genid = 0;
2168 rth->dst.input = ip_forward;
2169 rth->dst.output = ip_output;
2171 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2179 static int ip_mkroute_input(struct sk_buff *skb,
2180 struct fib_result *res,
2181 const struct flowi4 *fl4,
2182 struct in_device *in_dev,
2183 __be32 daddr, __be32 saddr, u32 tos)
2185 struct rtable* rth = NULL;
2189 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2190 if (res->fi && res->fi->fib_nhs > 1)
2191 fib_select_multipath(res);
2194 /* create a routing cache entry */
2195 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2199 /* put it into the cache */
2200 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2201 rt_genid(dev_net(rth->dst.dev)));
2202 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2204 return PTR_ERR(rth);
2209 * NOTE. We drop all the packets that has local source
2210 * addresses, because every properly looped back packet
2211 * must have correct destination already attached by output routine.
2213 * Such approach solves two big problems:
2214 * 1. Not simplex devices are handled properly.
2215 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2216 * called with rcu_read_lock()
2219 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2220 u8 tos, struct net_device *dev)
2222 struct fib_result res;
2223 struct in_device *in_dev = __in_dev_get_rcu(dev);
2227 struct rtable * rth;
2231 struct net * net = dev_net(dev);
2233 /* IP on this device is disabled. */
2238 /* Check for the most weird martians, which can be not detected
2242 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2243 ipv4_is_loopback(saddr))
2244 goto martian_source;
2246 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2249 /* Accept zero addresses only to limited broadcast;
2250 * I even do not know to fix it or not. Waiting for complains :-)
2252 if (ipv4_is_zeronet(saddr))
2253 goto martian_source;
2255 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2256 goto martian_destination;
2259 * Now we are ready to route packet.
2262 fl4.flowi4_iif = dev->ifindex;
2263 fl4.flowi4_mark = skb->mark;
2264 fl4.flowi4_tos = tos;
2265 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2268 err = fib_lookup(net, &fl4, &res);
2270 if (!IN_DEV_FORWARD(in_dev))
2275 RT_CACHE_STAT_INC(in_slow_tot);
2277 if (res.type == RTN_BROADCAST)
2280 if (res.type == RTN_LOCAL) {
2281 err = fib_validate_source(skb, saddr, daddr, tos,
2282 net->loopback_dev->ifindex,
2283 dev, &spec_dst, &itag);
2285 goto martian_source_keep_err;
2287 flags |= RTCF_DIRECTSRC;
2292 if (!IN_DEV_FORWARD(in_dev))
2294 if (res.type != RTN_UNICAST)
2295 goto martian_destination;
2297 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2301 if (skb->protocol != htons(ETH_P_IP))
2304 if (ipv4_is_zeronet(saddr))
2305 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2307 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2310 goto martian_source_keep_err;
2312 flags |= RTCF_DIRECTSRC;
2314 flags |= RTCF_BROADCAST;
2315 res.type = RTN_BROADCAST;
2316 RT_CACHE_STAT_INC(in_brd);
2319 rth = rt_dst_alloc(net->loopback_dev,
2320 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2324 rth->dst.input= ip_local_deliver;
2325 rth->dst.output= ip_rt_bug;
2326 #ifdef CONFIG_IP_ROUTE_CLASSID
2327 rth->dst.tclassid = itag;
2330 rth->rt_key_dst = daddr;
2331 rth->rt_key_src = saddr;
2332 rth->rt_genid = rt_genid(net);
2333 rth->rt_flags = flags|RTCF_LOCAL;
2334 rth->rt_type = res.type;
2335 rth->rt_key_tos = tos;
2336 rth->rt_dst = daddr;
2337 rth->rt_src = saddr;
2338 #ifdef CONFIG_IP_ROUTE_CLASSID
2339 rth->dst.tclassid = itag;
2341 rth->rt_route_iif = dev->ifindex;
2342 rth->rt_iif = dev->ifindex;
2344 rth->rt_mark = skb->mark;
2345 rth->rt_gateway = daddr;
2346 rth->rt_spec_dst= spec_dst;
2347 rth->rt_peer_genid = 0;
2350 if (res.type == RTN_UNREACHABLE) {
2351 rth->dst.input= ip_error;
2352 rth->dst.error= -err;
2353 rth->rt_flags &= ~RTCF_LOCAL;
2355 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2356 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2363 RT_CACHE_STAT_INC(in_no_route);
2364 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2365 res.type = RTN_UNREACHABLE;
2371 * Do not cache martian addresses: they should be logged (RFC1812)
2373 martian_destination:
2374 RT_CACHE_STAT_INC(in_martian_dst);
2375 #ifdef CONFIG_IP_ROUTE_VERBOSE
2376 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2377 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2378 &daddr, &saddr, dev->name);
2382 err = -EHOSTUNREACH;
2395 martian_source_keep_err:
2396 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2400 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2401 u8 tos, struct net_device *dev, bool noref)
2403 struct rtable * rth;
2405 int iif = dev->ifindex;
2413 if (!rt_caching(net))
2416 tos &= IPTOS_RT_MASK;
2417 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2419 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2420 rth = rcu_dereference(rth->dst.rt_next)) {
2421 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2422 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2423 (rth->rt_route_iif ^ iif) |
2424 (rth->rt_key_tos ^ tos)) == 0 &&
2425 rth->rt_mark == skb->mark &&
2426 net_eq(dev_net(rth->dst.dev), net) &&
2427 !rt_is_expired(rth)) {
2429 dst_use_noref(&rth->dst, jiffies);
2430 skb_dst_set_noref(skb, &rth->dst);
2432 dst_use(&rth->dst, jiffies);
2433 skb_dst_set(skb, &rth->dst);
2435 RT_CACHE_STAT_INC(in_hit);
2439 RT_CACHE_STAT_INC(in_hlist_search);
2443 /* Multicast recognition logic is moved from route cache to here.
2444 The problem was that too many Ethernet cards have broken/missing
2445 hardware multicast filters :-( As result the host on multicasting
2446 network acquires a lot of useless route cache entries, sort of
2447 SDR messages from all the world. Now we try to get rid of them.
2448 Really, provided software IP multicast filter is organized
2449 reasonably (at least, hashed), it does not result in a slowdown
2450 comparing with route cache reject entries.
2451 Note, that multicast routers are not affected, because
2452 route cache entry is created eventually.
2454 if (ipv4_is_multicast(daddr)) {
2455 struct in_device *in_dev = __in_dev_get_rcu(dev);
2458 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2459 ip_hdr(skb)->protocol);
2461 #ifdef CONFIG_IP_MROUTE
2463 (!ipv4_is_local_multicast(daddr) &&
2464 IN_DEV_MFORWARD(in_dev))
2467 int res = ip_route_input_mc(skb, daddr, saddr,
2476 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2480 EXPORT_SYMBOL(ip_route_input_common);
2482 /* called with rcu_read_lock() */
2483 static struct rtable *__mkroute_output(const struct fib_result *res,
2484 const struct flowi4 *fl4,
2485 __be32 orig_daddr, __be32 orig_saddr,
2486 int orig_oif, struct net_device *dev_out,
2489 struct fib_info *fi = res->fi;
2490 u32 tos = RT_FL_TOS(fl4);
2491 struct in_device *in_dev;
2492 u16 type = res->type;
2495 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2496 return ERR_PTR(-EINVAL);
2498 if (ipv4_is_lbcast(fl4->daddr))
2499 type = RTN_BROADCAST;
2500 else if (ipv4_is_multicast(fl4->daddr))
2501 type = RTN_MULTICAST;
2502 else if (ipv4_is_zeronet(fl4->daddr))
2503 return ERR_PTR(-EINVAL);
2505 if (dev_out->flags & IFF_LOOPBACK)
2506 flags |= RTCF_LOCAL;
2508 in_dev = __in_dev_get_rcu(dev_out);
2510 return ERR_PTR(-EINVAL);
2512 if (type == RTN_BROADCAST) {
2513 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2515 } else if (type == RTN_MULTICAST) {
2516 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2517 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2519 flags &= ~RTCF_LOCAL;
2520 /* If multicast route do not exist use
2521 * default one, but do not gateway in this case.
2524 if (fi && res->prefixlen < 4)
2528 rth = rt_dst_alloc(dev_out,
2529 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2530 IN_DEV_CONF_GET(in_dev, NOXFRM));
2532 return ERR_PTR(-ENOBUFS);
2534 rth->dst.output = ip_output;
2536 rth->rt_key_dst = orig_daddr;
2537 rth->rt_key_src = orig_saddr;
2538 rth->rt_genid = rt_genid(dev_net(dev_out));
2539 rth->rt_flags = flags;
2540 rth->rt_type = type;
2541 rth->rt_key_tos = tos;
2542 rth->rt_dst = fl4->daddr;
2543 rth->rt_src = fl4->saddr;
2544 rth->rt_route_iif = 0;
2545 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2546 rth->rt_oif = orig_oif;
2547 rth->rt_mark = fl4->flowi4_mark;
2548 rth->rt_gateway = fl4->daddr;
2549 rth->rt_spec_dst= fl4->saddr;
2550 rth->rt_peer_genid = 0;
2554 RT_CACHE_STAT_INC(out_slow_tot);
2556 if (flags & RTCF_LOCAL) {
2557 rth->dst.input = ip_local_deliver;
2558 rth->rt_spec_dst = fl4->daddr;
2560 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2561 rth->rt_spec_dst = fl4->saddr;
2562 if (flags & RTCF_LOCAL &&
2563 !(dev_out->flags & IFF_LOOPBACK)) {
2564 rth->dst.output = ip_mc_output;
2565 RT_CACHE_STAT_INC(out_slow_mc);
2567 #ifdef CONFIG_IP_MROUTE
2568 if (type == RTN_MULTICAST) {
2569 if (IN_DEV_MFORWARD(in_dev) &&
2570 !ipv4_is_local_multicast(fl4->daddr)) {
2571 rth->dst.input = ip_mr_input;
2572 rth->dst.output = ip_mc_output;
2578 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2584 * Major route resolver routine.
2585 * called with rcu_read_lock();
2588 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2590 struct net_device *dev_out = NULL;
2591 u32 tos = RT_FL_TOS(fl4);
2592 unsigned int flags = 0;
2593 struct fib_result res;
2600 #ifdef CONFIG_IP_MULTIPLE_TABLES
2604 orig_daddr = fl4->daddr;
2605 orig_saddr = fl4->saddr;
2606 orig_oif = fl4->flowi4_oif;
2608 fl4->flowi4_iif = net->loopback_dev->ifindex;
2609 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2610 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2611 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2615 rth = ERR_PTR(-EINVAL);
2616 if (ipv4_is_multicast(fl4->saddr) ||
2617 ipv4_is_lbcast(fl4->saddr) ||
2618 ipv4_is_zeronet(fl4->saddr))
2621 /* I removed check for oif == dev_out->oif here.
2622 It was wrong for two reasons:
2623 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2624 is assigned to multiple interfaces.
2625 2. Moreover, we are allowed to send packets with saddr
2626 of another iface. --ANK
2629 if (fl4->flowi4_oif == 0 &&
2630 (ipv4_is_multicast(fl4->daddr) ||
2631 ipv4_is_lbcast(fl4->daddr))) {
2632 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2633 dev_out = __ip_dev_find(net, fl4->saddr, false);
2634 if (dev_out == NULL)
2637 /* Special hack: user can direct multicasts
2638 and limited broadcast via necessary interface
2639 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2640 This hack is not just for fun, it allows
2641 vic,vat and friends to work.
2642 They bind socket to loopback, set ttl to zero
2643 and expect that it will work.
2644 From the viewpoint of routing cache they are broken,
2645 because we are not allowed to build multicast path
2646 with loopback source addr (look, routing cache
2647 cannot know, that ttl is zero, so that packet
2648 will not leave this host and route is valid).
2649 Luckily, this hack is good workaround.
2652 fl4->flowi4_oif = dev_out->ifindex;
2656 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2657 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2658 if (!__ip_dev_find(net, fl4->saddr, false))
2664 if (fl4->flowi4_oif) {
2665 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2666 rth = ERR_PTR(-ENODEV);
2667 if (dev_out == NULL)
2670 /* RACE: Check return value of inet_select_addr instead. */
2671 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2672 rth = ERR_PTR(-ENETUNREACH);
2675 if (ipv4_is_local_multicast(fl4->daddr) ||
2676 ipv4_is_lbcast(fl4->daddr)) {
2678 fl4->saddr = inet_select_addr(dev_out, 0,
2683 if (ipv4_is_multicast(fl4->daddr))
2684 fl4->saddr = inet_select_addr(dev_out, 0,
2686 else if (!fl4->daddr)
2687 fl4->saddr = inet_select_addr(dev_out, 0,
2693 fl4->daddr = fl4->saddr;
2695 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2696 dev_out = net->loopback_dev;
2697 fl4->flowi4_oif = net->loopback_dev->ifindex;
2698 res.type = RTN_LOCAL;
2699 flags |= RTCF_LOCAL;
2703 if (fib_lookup(net, fl4, &res)) {
2705 if (fl4->flowi4_oif) {
2706 /* Apparently, routing tables are wrong. Assume,
2707 that the destination is on link.
2710 Because we are allowed to send to iface
2711 even if it has NO routes and NO assigned
2712 addresses. When oif is specified, routing
2713 tables are looked up with only one purpose:
2714 to catch if destination is gatewayed, rather than
2715 direct. Moreover, if MSG_DONTROUTE is set,
2716 we send packet, ignoring both routing tables
2717 and ifaddr state. --ANK
2720 We could make it even if oif is unknown,
2721 likely IPv6, but we do not.
2724 if (fl4->saddr == 0)
2725 fl4->saddr = inet_select_addr(dev_out, 0,
2727 res.type = RTN_UNICAST;
2730 rth = ERR_PTR(-ENETUNREACH);
2734 if (res.type == RTN_LOCAL) {
2736 if (res.fi->fib_prefsrc)
2737 fl4->saddr = res.fi->fib_prefsrc;
2739 fl4->saddr = fl4->daddr;
2741 dev_out = net->loopback_dev;
2742 fl4->flowi4_oif = dev_out->ifindex;
2744 flags |= RTCF_LOCAL;
2748 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2749 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2750 fib_select_multipath(&res);
2753 if (!res.prefixlen &&
2754 res.table->tb_num_default > 1 &&
2755 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2756 fib_select_default(&res);
2758 dev_out = FIB_RES_DEV(res);
2759 if (dev_out == NULL) {
2760 rth = ERR_PTR(-ENODEV);
2765 fl4->saddr = FIB_RES_PREFSRC(net, res);
2767 fl4->flowi4_oif = dev_out->ifindex;
2771 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2776 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2777 rt_genid(dev_net(dev_out)));
2778 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2786 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2791 if (!rt_caching(net))
2794 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2797 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2798 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2799 if (rth->rt_key_dst == flp4->daddr &&
2800 rth->rt_key_src == flp4->saddr &&
2801 rt_is_output_route(rth) &&
2802 rth->rt_oif == flp4->flowi4_oif &&
2803 rth->rt_mark == flp4->flowi4_mark &&
2804 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2805 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2806 net_eq(dev_net(rth->dst.dev), net) &&
2807 !rt_is_expired(rth)) {
2808 dst_use(&rth->dst, jiffies);
2809 RT_CACHE_STAT_INC(out_hit);
2810 rcu_read_unlock_bh();
2812 flp4->saddr = rth->rt_src;
2814 flp4->daddr = rth->rt_dst;
2817 RT_CACHE_STAT_INC(out_hlist_search);
2819 rcu_read_unlock_bh();
2822 return ip_route_output_slow(net, flp4);
2824 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2826 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2831 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst)
2836 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2840 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2846 static struct dst_ops ipv4_dst_blackhole_ops = {
2848 .protocol = cpu_to_be16(ETH_P_IP),
2849 .destroy = ipv4_dst_destroy,
2850 .check = ipv4_blackhole_dst_check,
2851 .default_mtu = ipv4_blackhole_default_mtu,
2852 .default_advmss = ipv4_default_advmss,
2853 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2854 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2857 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2859 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2860 struct rtable *ort = (struct rtable *) dst_orig;
2863 struct dst_entry *new = &rt->dst;
2866 new->input = dst_discard;
2867 new->output = dst_discard;
2868 dst_copy_metrics(new, &ort->dst);
2870 new->dev = ort->dst.dev;
2874 rt->rt_key_dst = ort->rt_key_dst;
2875 rt->rt_key_src = ort->rt_key_src;
2876 rt->rt_key_tos = ort->rt_key_tos;
2877 rt->rt_route_iif = ort->rt_route_iif;
2878 rt->rt_iif = ort->rt_iif;
2879 rt->rt_oif = ort->rt_oif;
2880 rt->rt_mark = ort->rt_mark;
2882 rt->rt_genid = rt_genid(net);
2883 rt->rt_flags = ort->rt_flags;
2884 rt->rt_type = ort->rt_type;
2885 rt->rt_dst = ort->rt_dst;
2886 rt->rt_src = ort->rt_src;
2887 rt->rt_gateway = ort->rt_gateway;
2888 rt->rt_spec_dst = ort->rt_spec_dst;
2889 rt->peer = ort->peer;
2891 atomic_inc(&rt->peer->refcnt);
2894 atomic_inc(&rt->fi->fib_clntref);
2899 dst_release(dst_orig);
2901 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2904 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2907 struct rtable *rt = __ip_route_output_key(net, flp4);
2912 if (flp4->flowi4_proto)
2913 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2914 flowi4_to_flowi(flp4),
2919 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2921 static int rt_fill_info(struct net *net,
2922 struct sk_buff *skb, u32 pid, u32 seq, int event,
2923 int nowait, unsigned int flags)
2925 struct rtable *rt = skb_rtable(skb);
2927 struct nlmsghdr *nlh;
2929 const struct inet_peer *peer = rt->peer;
2930 u32 id = 0, ts = 0, tsage = 0, error;
2932 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2936 r = nlmsg_data(nlh);
2937 r->rtm_family = AF_INET;
2938 r->rtm_dst_len = 32;
2940 r->rtm_tos = rt->rt_key_tos;
2941 r->rtm_table = RT_TABLE_MAIN;
2942 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2943 r->rtm_type = rt->rt_type;
2944 r->rtm_scope = RT_SCOPE_UNIVERSE;
2945 r->rtm_protocol = RTPROT_UNSPEC;
2946 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2947 if (rt->rt_flags & RTCF_NOTIFY)
2948 r->rtm_flags |= RTM_F_NOTIFY;
2950 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2952 if (rt->rt_key_src) {
2953 r->rtm_src_len = 32;
2954 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2957 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2958 #ifdef CONFIG_IP_ROUTE_CLASSID
2959 if (rt->dst.tclassid)
2960 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2962 if (rt_is_input_route(rt))
2963 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2964 else if (rt->rt_src != rt->rt_key_src)
2965 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2967 if (rt->rt_dst != rt->rt_gateway)
2968 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2970 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2971 goto nla_put_failure;
2974 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
2976 error = rt->dst.error;
2978 inet_peer_refcheck(rt->peer);
2979 id = atomic_read(&peer->ip_id_count) & 0xffff;
2980 if (peer->tcp_ts_stamp) {
2982 tsage = get_seconds() - peer->tcp_ts_stamp;
2984 expires = ACCESS_ONCE(peer->pmtu_expires);
2989 if (rt_is_input_route(rt)) {
2990 #ifdef CONFIG_IP_MROUTE
2991 __be32 dst = rt->rt_dst;
2993 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2994 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2995 int err = ipmr_get_route(net, skb,
2996 rt->rt_src, rt->rt_dst,
3002 goto nla_put_failure;
3004 if (err == -EMSGSIZE)
3005 goto nla_put_failure;
3011 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
3014 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
3015 expires, error) < 0)
3016 goto nla_put_failure;
3018 return nlmsg_end(skb, nlh);
3021 nlmsg_cancel(skb, nlh);
3025 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
3027 struct net *net = sock_net(in_skb->sk);
3029 struct nlattr *tb[RTA_MAX+1];
3030 struct rtable *rt = NULL;
3036 struct sk_buff *skb;
3038 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
3042 rtm = nlmsg_data(nlh);
3044 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3050 /* Reserve room for dummy headers, this skb can pass
3051 through good chunk of routing engine.
3053 skb_reset_mac_header(skb);
3054 skb_reset_network_header(skb);
3056 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
3057 ip_hdr(skb)->protocol = IPPROTO_ICMP;
3058 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
3060 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
3061 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
3062 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
3063 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
3066 struct net_device *dev;
3068 dev = __dev_get_by_index(net, iif);
3074 skb->protocol = htons(ETH_P_IP);
3078 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
3081 rt = skb_rtable(skb);
3082 if (err == 0 && rt->dst.error)
3083 err = -rt->dst.error;
3085 struct flowi4 fl4 = {
3088 .flowi4_tos = rtm->rtm_tos,
3089 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
3090 .flowi4_mark = mark,
3092 rt = ip_route_output_key(net, &fl4);
3102 skb_dst_set(skb, &rt->dst);
3103 if (rtm->rtm_flags & RTM_F_NOTIFY)
3104 rt->rt_flags |= RTCF_NOTIFY;
3106 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3107 RTM_NEWROUTE, 0, 0);
3111 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3120 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3127 net = sock_net(skb->sk);
3132 s_idx = idx = cb->args[1];
3133 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3134 if (!rt_hash_table[h].chain)
3137 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3138 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3139 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3141 if (rt_is_expired(rt))
3143 skb_dst_set_noref(skb, &rt->dst);
3144 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3145 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3146 1, NLM_F_MULTI) <= 0) {
3148 rcu_read_unlock_bh();
3153 rcu_read_unlock_bh();
3162 void ip_rt_multicast_event(struct in_device *in_dev)
3164 rt_cache_flush(dev_net(in_dev->dev), 0);
3167 #ifdef CONFIG_SYSCTL
3168 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3169 void __user *buffer,
3170 size_t *lenp, loff_t *ppos)
3177 memcpy(&ctl, __ctl, sizeof(ctl));
3178 ctl.data = &flush_delay;
3179 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3181 net = (struct net *)__ctl->extra1;
3182 rt_cache_flush(net, flush_delay);
3189 static ctl_table ipv4_route_table[] = {
3191 .procname = "gc_thresh",
3192 .data = &ipv4_dst_ops.gc_thresh,
3193 .maxlen = sizeof(int),
3195 .proc_handler = proc_dointvec,
3198 .procname = "max_size",
3199 .data = &ip_rt_max_size,
3200 .maxlen = sizeof(int),
3202 .proc_handler = proc_dointvec,
3205 /* Deprecated. Use gc_min_interval_ms */
3207 .procname = "gc_min_interval",
3208 .data = &ip_rt_gc_min_interval,
3209 .maxlen = sizeof(int),
3211 .proc_handler = proc_dointvec_jiffies,
3214 .procname = "gc_min_interval_ms",
3215 .data = &ip_rt_gc_min_interval,
3216 .maxlen = sizeof(int),
3218 .proc_handler = proc_dointvec_ms_jiffies,
3221 .procname = "gc_timeout",
3222 .data = &ip_rt_gc_timeout,
3223 .maxlen = sizeof(int),
3225 .proc_handler = proc_dointvec_jiffies,
3228 .procname = "gc_interval",
3229 .data = &ip_rt_gc_interval,
3230 .maxlen = sizeof(int),
3232 .proc_handler = proc_dointvec_jiffies,
3235 .procname = "gc_interval",
3236 .data = &ip_rt_gc_interval,
3237 .maxlen = sizeof(int),
3239 .proc_handler = proc_dointvec_jiffies,
3242 .procname = "redirect_load",
3243 .data = &ip_rt_redirect_load,
3244 .maxlen = sizeof(int),
3246 .proc_handler = proc_dointvec,
3249 .procname = "redirect_number",
3250 .data = &ip_rt_redirect_number,
3251 .maxlen = sizeof(int),
3253 .proc_handler = proc_dointvec,
3256 .procname = "redirect_silence",
3257 .data = &ip_rt_redirect_silence,
3258 .maxlen = sizeof(int),
3260 .proc_handler = proc_dointvec,
3263 .procname = "error_cost",
3264 .data = &ip_rt_error_cost,
3265 .maxlen = sizeof(int),
3267 .proc_handler = proc_dointvec,
3270 .procname = "error_burst",
3271 .data = &ip_rt_error_burst,
3272 .maxlen = sizeof(int),
3274 .proc_handler = proc_dointvec,
3277 .procname = "gc_elasticity",
3278 .data = &ip_rt_gc_elasticity,
3279 .maxlen = sizeof(int),
3281 .proc_handler = proc_dointvec,
3284 .procname = "mtu_expires",
3285 .data = &ip_rt_mtu_expires,
3286 .maxlen = sizeof(int),
3288 .proc_handler = proc_dointvec_jiffies,
3291 .procname = "min_pmtu",
3292 .data = &ip_rt_min_pmtu,
3293 .maxlen = sizeof(int),
3295 .proc_handler = proc_dointvec,
3298 .procname = "min_adv_mss",
3299 .data = &ip_rt_min_advmss,
3300 .maxlen = sizeof(int),
3302 .proc_handler = proc_dointvec,
3307 static struct ctl_table empty[1];
3309 static struct ctl_table ipv4_skeleton[] =
3311 { .procname = "route",
3312 .mode = 0555, .child = ipv4_route_table},
3313 { .procname = "neigh",
3314 .mode = 0555, .child = empty},
3318 static __net_initdata struct ctl_path ipv4_path[] = {
3319 { .procname = "net", },
3320 { .procname = "ipv4", },
3324 static struct ctl_table ipv4_route_flush_table[] = {
3326 .procname = "flush",
3327 .maxlen = sizeof(int),
3329 .proc_handler = ipv4_sysctl_rtcache_flush,
3334 static __net_initdata struct ctl_path ipv4_route_path[] = {
3335 { .procname = "net", },
3336 { .procname = "ipv4", },
3337 { .procname = "route", },
3341 static __net_init int sysctl_route_net_init(struct net *net)
3343 struct ctl_table *tbl;
3345 tbl = ipv4_route_flush_table;
3346 if (!net_eq(net, &init_net)) {
3347 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3351 tbl[0].extra1 = net;
3353 net->ipv4.route_hdr =
3354 register_net_sysctl_table(net, ipv4_route_path, tbl);
3355 if (net->ipv4.route_hdr == NULL)
3360 if (tbl != ipv4_route_flush_table)
3366 static __net_exit void sysctl_route_net_exit(struct net *net)
3368 struct ctl_table *tbl;
3370 tbl = net->ipv4.route_hdr->ctl_table_arg;
3371 unregister_net_sysctl_table(net->ipv4.route_hdr);
3372 BUG_ON(tbl == ipv4_route_flush_table);
3376 static __net_initdata struct pernet_operations sysctl_route_ops = {
3377 .init = sysctl_route_net_init,
3378 .exit = sysctl_route_net_exit,
3382 static __net_init int rt_genid_init(struct net *net)
3384 get_random_bytes(&net->ipv4.rt_genid,
3385 sizeof(net->ipv4.rt_genid));
3386 get_random_bytes(&net->ipv4.dev_addr_genid,
3387 sizeof(net->ipv4.dev_addr_genid));
3391 static __net_initdata struct pernet_operations rt_genid_ops = {
3392 .init = rt_genid_init,
3396 #ifdef CONFIG_IP_ROUTE_CLASSID
3397 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3398 #endif /* CONFIG_IP_ROUTE_CLASSID */
3400 static __initdata unsigned long rhash_entries;
3401 static int __init set_rhash_entries(char *str)
3405 rhash_entries = simple_strtoul(str, &str, 0);
3408 __setup("rhash_entries=", set_rhash_entries);
3410 int __init ip_rt_init(void)
3414 #ifdef CONFIG_IP_ROUTE_CLASSID
3415 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3417 panic("IP: failed to allocate ip_rt_acct\n");
3420 ipv4_dst_ops.kmem_cachep =
3421 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3422 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3424 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3426 if (dst_entries_init(&ipv4_dst_ops) < 0)
3427 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3429 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3430 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3432 rt_hash_table = (struct rt_hash_bucket *)
3433 alloc_large_system_hash("IP route cache",
3434 sizeof(struct rt_hash_bucket),
3436 (totalram_pages >= 128 * 1024) ?
3441 rhash_entries ? 0 : 512 * 1024);
3442 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3443 rt_hash_lock_init();
3445 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3446 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3451 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func);
3452 expires_ljiffies = jiffies;
3453 schedule_delayed_work(&expires_work,
3454 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3456 if (ip_rt_proc_init())
3457 printk(KERN_ERR "Unable to create route proc files\n");
3460 xfrm4_init(ip_rt_max_size);
3462 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
3464 #ifdef CONFIG_SYSCTL
3465 register_pernet_subsys(&sysctl_route_ops);
3467 register_pernet_subsys(&rt_genid_ops);
3471 #ifdef CONFIG_SYSCTL
3473 * We really need to sanitize the damn ipv4 init order, then all
3474 * this nonsense will go away.
3476 void __init ip_static_sysctl_init(void)
3478 register_sysctl_paths(ipv4_path, ipv4_skeleton);