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 #define pr_fmt(fmt) "IPv4: " fmt
67 #include <linux/module.h>
68 #include <asm/uaccess.h>
69 #include <linux/bitops.h>
70 #include <linux/types.h>
71 #include <linux/kernel.h>
73 #include <linux/bootmem.h>
74 #include <linux/string.h>
75 #include <linux/socket.h>
76 #include <linux/sockios.h>
77 #include <linux/errno.h>
79 #include <linux/inet.h>
80 #include <linux/netdevice.h>
81 #include <linux/proc_fs.h>
82 #include <linux/init.h>
83 #include <linux/workqueue.h>
84 #include <linux/skbuff.h>
85 #include <linux/inetdevice.h>
86 #include <linux/igmp.h>
87 #include <linux/pkt_sched.h>
88 #include <linux/mroute.h>
89 #include <linux/netfilter_ipv4.h>
90 #include <linux/random.h>
91 #include <linux/jhash.h>
92 #include <linux/rcupdate.h>
93 #include <linux/times.h>
94 #include <linux/slab.h>
95 #include <linux/prefetch.h>
97 #include <net/net_namespace.h>
98 #include <net/protocol.h>
100 #include <net/route.h>
101 #include <net/inetpeer.h>
102 #include <net/sock.h>
103 #include <net/ip_fib.h>
106 #include <net/icmp.h>
107 #include <net/xfrm.h>
108 #include <net/netevent.h>
109 #include <net/rtnetlink.h>
111 #include <linux/sysctl.h>
112 #include <linux/kmemleak.h>
114 #include <net/secure_seq.h>
116 #define RT_FL_TOS(oldflp4) \
117 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
119 #define IP_MAX_MTU 0xFFF0
121 #define RT_GC_TIMEOUT (300*HZ)
123 static int ip_rt_max_size;
124 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
125 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
126 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
127 static int ip_rt_redirect_number __read_mostly = 9;
128 static int ip_rt_redirect_load __read_mostly = HZ / 50;
129 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
130 static int ip_rt_error_cost __read_mostly = HZ;
131 static int ip_rt_error_burst __read_mostly = 5 * HZ;
132 static int ip_rt_gc_elasticity __read_mostly = 8;
133 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
134 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
135 static int ip_rt_min_advmss __read_mostly = 256;
136 static int rt_chain_length_max __read_mostly = 20;
138 static struct delayed_work expires_work;
139 static unsigned long expires_ljiffies;
142 * Interface to generic destination cache.
145 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
146 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
147 static unsigned int ipv4_mtu(const struct dst_entry *dst);
148 static void ipv4_dst_destroy(struct dst_entry *dst);
149 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
150 static void ipv4_link_failure(struct sk_buff *skb);
151 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
152 static int rt_garbage_collect(struct dst_ops *ops);
154 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
159 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
161 struct rtable *rt = (struct rtable *) dst;
162 struct inet_peer *peer;
165 peer = rt_get_peer_create(rt, rt->rt_dst);
167 u32 *old_p = __DST_METRICS_PTR(old);
168 unsigned long prev, new;
171 if (inet_metrics_new(peer))
172 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
174 new = (unsigned long) p;
175 prev = cmpxchg(&dst->_metrics, old, new);
178 p = __DST_METRICS_PTR(prev);
179 if (prev & DST_METRICS_READ_ONLY)
183 fib_info_put(rt->fi);
191 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr);
193 static struct dst_ops ipv4_dst_ops = {
195 .protocol = cpu_to_be16(ETH_P_IP),
196 .gc = rt_garbage_collect,
197 .check = ipv4_dst_check,
198 .default_advmss = ipv4_default_advmss,
200 .cow_metrics = ipv4_cow_metrics,
201 .destroy = ipv4_dst_destroy,
202 .ifdown = ipv4_dst_ifdown,
203 .negative_advice = ipv4_negative_advice,
204 .link_failure = ipv4_link_failure,
205 .update_pmtu = ip_rt_update_pmtu,
206 .local_out = __ip_local_out,
207 .neigh_lookup = ipv4_neigh_lookup,
210 #define ECN_OR_COST(class) TC_PRIO_##class
212 const __u8 ip_tos2prio[16] = {
214 ECN_OR_COST(BESTEFFORT),
216 ECN_OR_COST(BESTEFFORT),
222 ECN_OR_COST(INTERACTIVE),
224 ECN_OR_COST(INTERACTIVE),
225 TC_PRIO_INTERACTIVE_BULK,
226 ECN_OR_COST(INTERACTIVE_BULK),
227 TC_PRIO_INTERACTIVE_BULK,
228 ECN_OR_COST(INTERACTIVE_BULK)
230 EXPORT_SYMBOL(ip_tos2prio);
236 /* The locking scheme is rather straight forward:
238 * 1) Read-Copy Update protects the buckets of the central route hash.
239 * 2) Only writers remove entries, and they hold the lock
240 * as they look at rtable reference counts.
241 * 3) Only readers acquire references to rtable entries,
242 * they do so with atomic increments and with the
246 struct rt_hash_bucket {
247 struct rtable __rcu *chain;
250 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
251 defined(CONFIG_PROVE_LOCKING)
253 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
254 * The size of this table is a power of two and depends on the number of CPUS.
255 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
257 #ifdef CONFIG_LOCKDEP
258 # define RT_HASH_LOCK_SZ 256
261 # define RT_HASH_LOCK_SZ 4096
263 # define RT_HASH_LOCK_SZ 2048
265 # define RT_HASH_LOCK_SZ 1024
267 # define RT_HASH_LOCK_SZ 512
269 # define RT_HASH_LOCK_SZ 256
273 static spinlock_t *rt_hash_locks;
274 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
276 static __init void rt_hash_lock_init(void)
280 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
283 panic("IP: failed to allocate rt_hash_locks\n");
285 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
286 spin_lock_init(&rt_hash_locks[i]);
289 # define rt_hash_lock_addr(slot) NULL
291 static inline void rt_hash_lock_init(void)
296 static struct rt_hash_bucket *rt_hash_table __read_mostly;
297 static unsigned int rt_hash_mask __read_mostly;
298 static unsigned int rt_hash_log __read_mostly;
300 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
301 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
303 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
306 return jhash_3words((__force u32)daddr, (__force u32)saddr,
311 static inline int rt_genid(struct net *net)
313 return atomic_read(&net->ipv4.rt_genid);
316 #ifdef CONFIG_PROC_FS
317 struct rt_cache_iter_state {
318 struct seq_net_private p;
323 static struct rtable *rt_cache_get_first(struct seq_file *seq)
325 struct rt_cache_iter_state *st = seq->private;
326 struct rtable *r = NULL;
328 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
329 if (!rcu_access_pointer(rt_hash_table[st->bucket].chain))
332 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
334 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
335 r->rt_genid == st->genid)
337 r = rcu_dereference_bh(r->dst.rt_next);
339 rcu_read_unlock_bh();
344 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
347 struct rt_cache_iter_state *st = seq->private;
349 r = rcu_dereference_bh(r->dst.rt_next);
351 rcu_read_unlock_bh();
353 if (--st->bucket < 0)
355 } while (!rcu_access_pointer(rt_hash_table[st->bucket].chain));
357 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
362 static struct rtable *rt_cache_get_next(struct seq_file *seq,
365 struct rt_cache_iter_state *st = seq->private;
366 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
367 if (dev_net(r->dst.dev) != seq_file_net(seq))
369 if (r->rt_genid == st->genid)
375 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
377 struct rtable *r = rt_cache_get_first(seq);
380 while (pos && (r = rt_cache_get_next(seq, r)))
382 return pos ? NULL : r;
385 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
387 struct rt_cache_iter_state *st = seq->private;
389 return rt_cache_get_idx(seq, *pos - 1);
390 st->genid = rt_genid(seq_file_net(seq));
391 return SEQ_START_TOKEN;
394 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
398 if (v == SEQ_START_TOKEN)
399 r = rt_cache_get_first(seq);
401 r = rt_cache_get_next(seq, v);
406 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
408 if (v && v != SEQ_START_TOKEN)
409 rcu_read_unlock_bh();
412 static int rt_cache_seq_show(struct seq_file *seq, void *v)
414 if (v == SEQ_START_TOKEN)
415 seq_printf(seq, "%-127s\n",
416 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
417 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
420 struct rtable *r = v;
425 n = dst_get_neighbour_noref(&r->dst);
426 HHUptod = (n && (n->nud_state & NUD_CONNECTED)) ? 1 : 0;
429 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
430 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
431 r->dst.dev ? r->dst.dev->name : "*",
432 (__force u32)r->rt_dst,
433 (__force u32)r->rt_gateway,
434 r->rt_flags, atomic_read(&r->dst.__refcnt),
435 r->dst.__use, 0, (__force u32)r->rt_src,
436 dst_metric_advmss(&r->dst) + 40,
437 dst_metric(&r->dst, RTAX_WINDOW),
438 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
439 dst_metric(&r->dst, RTAX_RTTVAR)),
443 r->rt_spec_dst, &len);
445 seq_printf(seq, "%*s\n", 127 - len, "");
450 static const struct seq_operations rt_cache_seq_ops = {
451 .start = rt_cache_seq_start,
452 .next = rt_cache_seq_next,
453 .stop = rt_cache_seq_stop,
454 .show = rt_cache_seq_show,
457 static int rt_cache_seq_open(struct inode *inode, struct file *file)
459 return seq_open_net(inode, file, &rt_cache_seq_ops,
460 sizeof(struct rt_cache_iter_state));
463 static const struct file_operations rt_cache_seq_fops = {
464 .owner = THIS_MODULE,
465 .open = rt_cache_seq_open,
468 .release = seq_release_net,
472 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
477 return SEQ_START_TOKEN;
479 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
480 if (!cpu_possible(cpu))
483 return &per_cpu(rt_cache_stat, cpu);
488 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
492 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
493 if (!cpu_possible(cpu))
496 return &per_cpu(rt_cache_stat, cpu);
502 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
507 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
509 struct rt_cache_stat *st = v;
511 if (v == SEQ_START_TOKEN) {
512 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");
516 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
517 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
518 dst_entries_get_slow(&ipv4_dst_ops),
541 static const struct seq_operations rt_cpu_seq_ops = {
542 .start = rt_cpu_seq_start,
543 .next = rt_cpu_seq_next,
544 .stop = rt_cpu_seq_stop,
545 .show = rt_cpu_seq_show,
549 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
551 return seq_open(file, &rt_cpu_seq_ops);
554 static const struct file_operations rt_cpu_seq_fops = {
555 .owner = THIS_MODULE,
556 .open = rt_cpu_seq_open,
559 .release = seq_release,
562 #ifdef CONFIG_IP_ROUTE_CLASSID
563 static int rt_acct_proc_show(struct seq_file *m, void *v)
565 struct ip_rt_acct *dst, *src;
568 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
572 for_each_possible_cpu(i) {
573 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
574 for (j = 0; j < 256; j++) {
575 dst[j].o_bytes += src[j].o_bytes;
576 dst[j].o_packets += src[j].o_packets;
577 dst[j].i_bytes += src[j].i_bytes;
578 dst[j].i_packets += src[j].i_packets;
582 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
587 static int rt_acct_proc_open(struct inode *inode, struct file *file)
589 return single_open(file, rt_acct_proc_show, NULL);
592 static const struct file_operations rt_acct_proc_fops = {
593 .owner = THIS_MODULE,
594 .open = rt_acct_proc_open,
597 .release = single_release,
601 static int __net_init ip_rt_do_proc_init(struct net *net)
603 struct proc_dir_entry *pde;
605 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
610 pde = proc_create("rt_cache", S_IRUGO,
611 net->proc_net_stat, &rt_cpu_seq_fops);
615 #ifdef CONFIG_IP_ROUTE_CLASSID
616 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
622 #ifdef CONFIG_IP_ROUTE_CLASSID
624 remove_proc_entry("rt_cache", net->proc_net_stat);
627 remove_proc_entry("rt_cache", net->proc_net);
632 static void __net_exit ip_rt_do_proc_exit(struct net *net)
634 remove_proc_entry("rt_cache", net->proc_net_stat);
635 remove_proc_entry("rt_cache", net->proc_net);
636 #ifdef CONFIG_IP_ROUTE_CLASSID
637 remove_proc_entry("rt_acct", net->proc_net);
641 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
642 .init = ip_rt_do_proc_init,
643 .exit = ip_rt_do_proc_exit,
646 static int __init ip_rt_proc_init(void)
648 return register_pernet_subsys(&ip_rt_proc_ops);
652 static inline int ip_rt_proc_init(void)
656 #endif /* CONFIG_PROC_FS */
658 static inline void rt_free(struct rtable *rt)
660 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
663 static inline void rt_drop(struct rtable *rt)
666 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
669 static inline int rt_fast_clean(struct rtable *rth)
671 /* Kill broadcast/multicast entries very aggresively, if they
672 collide in hash table with more useful entries */
673 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
674 rt_is_input_route(rth) && rth->dst.rt_next;
677 static inline int rt_valuable(struct rtable *rth)
679 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
680 (rt_has_peer(rth) && rt_peer_ptr(rth)->pmtu_expires);
683 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
688 if (atomic_read(&rth->dst.__refcnt))
691 age = jiffies - rth->dst.lastuse;
692 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
693 (age <= tmo2 && rt_valuable(rth)))
699 /* Bits of score are:
701 * 30: not quite useless
702 * 29..0: usage counter
704 static inline u32 rt_score(struct rtable *rt)
706 u32 score = jiffies - rt->dst.lastuse;
708 score = ~score & ~(3<<30);
713 if (rt_is_output_route(rt) ||
714 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
720 static inline bool rt_caching(const struct net *net)
722 return net->ipv4.current_rt_cache_rebuild_count <=
723 net->ipv4.sysctl_rt_cache_rebuild_count;
726 static inline bool compare_hash_inputs(const struct rtable *rt1,
727 const struct rtable *rt2)
729 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
730 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
731 (rt1->rt_route_iif ^ rt2->rt_route_iif)) == 0);
734 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
736 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
737 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
738 (rt1->rt_mark ^ rt2->rt_mark) |
739 (rt1->rt_key_tos ^ rt2->rt_key_tos) |
740 (rt1->rt_route_iif ^ rt2->rt_route_iif) |
741 (rt1->rt_oif ^ rt2->rt_oif)) == 0;
744 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
746 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
749 static inline int rt_is_expired(struct rtable *rth)
751 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
755 * Perform a full scan of hash table and free all entries.
756 * Can be called by a softirq or a process.
757 * In the later case, we want to be reschedule if necessary
759 static void rt_do_flush(struct net *net, int process_context)
762 struct rtable *rth, *next;
764 for (i = 0; i <= rt_hash_mask; i++) {
765 struct rtable __rcu **pprev;
768 if (process_context && need_resched())
770 rth = rcu_access_pointer(rt_hash_table[i].chain);
774 spin_lock_bh(rt_hash_lock_addr(i));
777 pprev = &rt_hash_table[i].chain;
778 rth = rcu_dereference_protected(*pprev,
779 lockdep_is_held(rt_hash_lock_addr(i)));
782 next = rcu_dereference_protected(rth->dst.rt_next,
783 lockdep_is_held(rt_hash_lock_addr(i)));
786 net_eq(dev_net(rth->dst.dev), net)) {
787 rcu_assign_pointer(*pprev, next);
788 rcu_assign_pointer(rth->dst.rt_next, list);
791 pprev = &rth->dst.rt_next;
796 spin_unlock_bh(rt_hash_lock_addr(i));
798 for (; list; list = next) {
799 next = rcu_dereference_protected(list->dst.rt_next, 1);
806 * While freeing expired entries, we compute average chain length
807 * and standard deviation, using fixed-point arithmetic.
808 * This to have an estimation of rt_chain_length_max
809 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
810 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
814 #define ONE (1UL << FRACT_BITS)
817 * Given a hash chain and an item in this hash chain,
818 * find if a previous entry has the same hash_inputs
819 * (but differs on tos, mark or oif)
820 * Returns 0 if an alias is found.
821 * Returns ONE if rth has no alias before itself.
823 static int has_noalias(const struct rtable *head, const struct rtable *rth)
825 const struct rtable *aux = head;
828 if (compare_hash_inputs(aux, rth))
830 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
835 static void rt_check_expire(void)
837 static unsigned int rover;
838 unsigned int i = rover, goal;
840 struct rtable __rcu **rthp;
841 unsigned long samples = 0;
842 unsigned long sum = 0, sum2 = 0;
846 delta = jiffies - expires_ljiffies;
847 expires_ljiffies = jiffies;
848 mult = ((u64)delta) << rt_hash_log;
849 if (ip_rt_gc_timeout > 1)
850 do_div(mult, ip_rt_gc_timeout);
851 goal = (unsigned int)mult;
852 if (goal > rt_hash_mask)
853 goal = rt_hash_mask + 1;
854 for (; goal > 0; goal--) {
855 unsigned long tmo = ip_rt_gc_timeout;
856 unsigned long length;
858 i = (i + 1) & rt_hash_mask;
859 rthp = &rt_hash_table[i].chain;
866 if (rcu_dereference_raw(*rthp) == NULL)
869 spin_lock_bh(rt_hash_lock_addr(i));
870 while ((rth = rcu_dereference_protected(*rthp,
871 lockdep_is_held(rt_hash_lock_addr(i)))) != NULL) {
872 prefetch(rth->dst.rt_next);
873 if (rt_is_expired(rth)) {
874 *rthp = rth->dst.rt_next;
878 if (rth->dst.expires) {
879 /* Entry is expired even if it is in use */
880 if (time_before_eq(jiffies, rth->dst.expires)) {
883 rthp = &rth->dst.rt_next;
885 * We only count entries on
886 * a chain with equal hash inputs once
887 * so that entries for different QOS
888 * levels, and other non-hash input
889 * attributes don't unfairly skew
890 * the length computation
892 length += has_noalias(rt_hash_table[i].chain, rth);
895 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout))
898 /* Cleanup aged off entries. */
899 *rthp = rth->dst.rt_next;
902 spin_unlock_bh(rt_hash_lock_addr(i));
904 sum2 += length*length;
907 unsigned long avg = sum / samples;
908 unsigned long sd = int_sqrt(sum2 / samples - avg*avg);
909 rt_chain_length_max = max_t(unsigned long,
911 (avg + 4*sd) >> FRACT_BITS);
917 * rt_worker_func() is run in process context.
918 * we call rt_check_expire() to scan part of the hash table
920 static void rt_worker_func(struct work_struct *work)
923 schedule_delayed_work(&expires_work, ip_rt_gc_interval);
927 * Perturbation of rt_genid by a small quantity [1..256]
928 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
929 * many times (2^24) without giving recent rt_genid.
930 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
932 static void rt_cache_invalidate(struct net *net)
934 unsigned char shuffle;
936 get_random_bytes(&shuffle, sizeof(shuffle));
937 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
938 inetpeer_invalidate_family(AF_INET);
942 * delay < 0 : invalidate cache (fast : entries will be deleted later)
943 * delay >= 0 : invalidate & flush cache (can be long)
945 void rt_cache_flush(struct net *net, int delay)
947 rt_cache_invalidate(net);
949 rt_do_flush(net, !in_softirq());
952 /* Flush previous cache invalidated entries from the cache */
953 void rt_cache_flush_batch(struct net *net)
955 rt_do_flush(net, !in_softirq());
958 static void rt_emergency_hash_rebuild(struct net *net)
960 net_warn_ratelimited("Route hash chain too long!\n");
961 rt_cache_invalidate(net);
965 Short description of GC goals.
967 We want to build algorithm, which will keep routing cache
968 at some equilibrium point, when number of aged off entries
969 is kept approximately equal to newly generated ones.
971 Current expiration strength is variable "expire".
972 We try to adjust it dynamically, so that if networking
973 is idle expires is large enough to keep enough of warm entries,
974 and when load increases it reduces to limit cache size.
977 static int rt_garbage_collect(struct dst_ops *ops)
979 static unsigned long expire = RT_GC_TIMEOUT;
980 static unsigned long last_gc;
982 static int equilibrium;
984 struct rtable __rcu **rthp;
985 unsigned long now = jiffies;
987 int entries = dst_entries_get_fast(&ipv4_dst_ops);
990 * Garbage collection is pretty expensive,
991 * do not make it too frequently.
994 RT_CACHE_STAT_INC(gc_total);
996 if (now - last_gc < ip_rt_gc_min_interval &&
997 entries < ip_rt_max_size) {
998 RT_CACHE_STAT_INC(gc_ignored);
1002 entries = dst_entries_get_slow(&ipv4_dst_ops);
1003 /* Calculate number of entries, which we want to expire now. */
1004 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
1006 if (equilibrium < ipv4_dst_ops.gc_thresh)
1007 equilibrium = ipv4_dst_ops.gc_thresh;
1008 goal = entries - equilibrium;
1010 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
1011 goal = entries - equilibrium;
1014 /* We are in dangerous area. Try to reduce cache really
1017 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
1018 equilibrium = entries - goal;
1021 if (now - last_gc >= ip_rt_gc_min_interval)
1025 equilibrium += goal;
1032 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
1033 unsigned long tmo = expire;
1035 k = (k + 1) & rt_hash_mask;
1036 rthp = &rt_hash_table[k].chain;
1037 spin_lock_bh(rt_hash_lock_addr(k));
1038 while ((rth = rcu_dereference_protected(*rthp,
1039 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
1040 if (!rt_is_expired(rth) &&
1041 !rt_may_expire(rth, tmo, expire)) {
1043 rthp = &rth->dst.rt_next;
1046 *rthp = rth->dst.rt_next;
1050 spin_unlock_bh(rt_hash_lock_addr(k));
1059 /* Goal is not achieved. We stop process if:
1061 - if expire reduced to zero. Otherwise, expire is halfed.
1062 - if table is not full.
1063 - if we are called from interrupt.
1064 - jiffies check is just fallback/debug loop breaker.
1065 We will not spin here for long time in any case.
1068 RT_CACHE_STAT_INC(gc_goal_miss);
1075 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
1077 } while (!in_softirq() && time_before_eq(jiffies, now));
1079 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
1081 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
1083 net_warn_ratelimited("dst cache overflow\n");
1084 RT_CACHE_STAT_INC(gc_dst_overflow);
1088 expire += ip_rt_gc_min_interval;
1089 if (expire > ip_rt_gc_timeout ||
1090 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
1091 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
1092 expire = ip_rt_gc_timeout;
1097 * Returns number of entries in a hash chain that have different hash_inputs
1099 static int slow_chain_length(const struct rtable *head)
1102 const struct rtable *rth = head;
1105 length += has_noalias(head, rth);
1106 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1108 return length >> FRACT_BITS;
1111 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr)
1113 static const __be32 inaddr_any = 0;
1114 struct net_device *dev = dst->dev;
1115 const __be32 *pkey = daddr;
1116 const struct rtable *rt;
1117 struct neighbour *n;
1119 rt = (const struct rtable *) dst;
1121 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
1123 else if (rt->rt_gateway)
1124 pkey = (const __be32 *) &rt->rt_gateway;
1126 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
1129 return neigh_create(&arp_tbl, pkey, dev);
1132 static int rt_bind_neighbour(struct rtable *rt)
1134 struct neighbour *n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
1137 dst_set_neighbour(&rt->dst, n);
1142 static struct rtable *rt_intern_hash(unsigned int hash, struct rtable *rt,
1143 struct sk_buff *skb, int ifindex)
1145 struct rtable *rth, *cand;
1146 struct rtable __rcu **rthp, **candp;
1150 int attempts = !in_softirq();
1154 min_score = ~(u32)0;
1159 if (!rt_caching(dev_net(rt->dst.dev))) {
1161 * If we're not caching, just tell the caller we
1162 * were successful and don't touch the route. The
1163 * caller hold the sole reference to the cache entry, and
1164 * it will be released when the caller is done with it.
1165 * If we drop it here, the callers have no way to resolve routes
1166 * when we're not caching. Instead, just point *rp at rt, so
1167 * the caller gets a single use out of the route
1168 * Note that we do rt_free on this new route entry, so that
1169 * once its refcount hits zero, we are still able to reap it
1171 * Note: To avoid expensive rcu stuff for this uncached dst,
1172 * we set DST_NOCACHE so that dst_release() can free dst without
1173 * waiting a grace period.
1176 rt->dst.flags |= DST_NOCACHE;
1177 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1178 int err = rt_bind_neighbour(rt);
1180 net_warn_ratelimited("Neighbour table failure & not caching routes\n");
1182 return ERR_PTR(err);
1189 rthp = &rt_hash_table[hash].chain;
1191 spin_lock_bh(rt_hash_lock_addr(hash));
1192 while ((rth = rcu_dereference_protected(*rthp,
1193 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1194 if (rt_is_expired(rth)) {
1195 *rthp = rth->dst.rt_next;
1199 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1201 *rthp = rth->dst.rt_next;
1203 * Since lookup is lockfree, the deletion
1204 * must be visible to another weakly ordered CPU before
1205 * the insertion at the start of the hash chain.
1207 rcu_assign_pointer(rth->dst.rt_next,
1208 rt_hash_table[hash].chain);
1210 * Since lookup is lockfree, the update writes
1211 * must be ordered for consistency on SMP.
1213 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1215 dst_use(&rth->dst, now);
1216 spin_unlock_bh(rt_hash_lock_addr(hash));
1220 skb_dst_set(skb, &rth->dst);
1224 if (!atomic_read(&rth->dst.__refcnt)) {
1225 u32 score = rt_score(rth);
1227 if (score <= min_score) {
1236 rthp = &rth->dst.rt_next;
1240 /* ip_rt_gc_elasticity used to be average length of chain
1241 * length, when exceeded gc becomes really aggressive.
1243 * The second limit is less certain. At the moment it allows
1244 * only 2 entries per bucket. We will see.
1246 if (chain_length > ip_rt_gc_elasticity) {
1247 *candp = cand->dst.rt_next;
1251 if (chain_length > rt_chain_length_max &&
1252 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1253 struct net *net = dev_net(rt->dst.dev);
1254 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1255 if (!rt_caching(net)) {
1256 pr_warn("%s: %d rebuilds is over limit, route caching disabled\n",
1257 rt->dst.dev->name, num);
1259 rt_emergency_hash_rebuild(net);
1260 spin_unlock_bh(rt_hash_lock_addr(hash));
1262 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1263 ifindex, rt_genid(net));
1268 /* Try to bind route to arp only if it is output
1269 route or unicast forwarding path.
1271 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1272 int err = rt_bind_neighbour(rt);
1274 spin_unlock_bh(rt_hash_lock_addr(hash));
1276 if (err != -ENOBUFS) {
1278 return ERR_PTR(err);
1281 /* Neighbour tables are full and nothing
1282 can be released. Try to shrink route cache,
1283 it is most likely it holds some neighbour records.
1285 if (attempts-- > 0) {
1286 int saved_elasticity = ip_rt_gc_elasticity;
1287 int saved_int = ip_rt_gc_min_interval;
1288 ip_rt_gc_elasticity = 1;
1289 ip_rt_gc_min_interval = 0;
1290 rt_garbage_collect(&ipv4_dst_ops);
1291 ip_rt_gc_min_interval = saved_int;
1292 ip_rt_gc_elasticity = saved_elasticity;
1296 net_warn_ratelimited("Neighbour table overflow\n");
1298 return ERR_PTR(-ENOBUFS);
1302 rt->dst.rt_next = rt_hash_table[hash].chain;
1305 * Since lookup is lockfree, we must make sure
1306 * previous writes to rt are committed to memory
1307 * before making rt visible to other CPUS.
1309 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1311 spin_unlock_bh(rt_hash_lock_addr(hash));
1315 skb_dst_set(skb, &rt->dst);
1319 static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1321 static u32 rt_peer_genid(void)
1323 return atomic_read(&__rt_peer_genid);
1326 void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
1328 struct inet_peer_base *base;
1329 struct inet_peer *peer;
1331 base = inetpeer_base_ptr(rt->_peer);
1335 peer = inet_getpeer_v4(base, daddr, create);
1337 if (!rt_set_peer(rt, peer))
1340 rt->rt_peer_genid = rt_peer_genid();
1345 * Peer allocation may fail only in serious out-of-memory conditions. However
1346 * we still can generate some output.
1347 * Random ID selection looks a bit dangerous because we have no chances to
1348 * select ID being unique in a reasonable period of time.
1349 * But broken packet identifier may be better than no packet at all.
1351 static void ip_select_fb_ident(struct iphdr *iph)
1353 static DEFINE_SPINLOCK(ip_fb_id_lock);
1354 static u32 ip_fallback_id;
1357 spin_lock_bh(&ip_fb_id_lock);
1358 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1359 iph->id = htons(salt & 0xFFFF);
1360 ip_fallback_id = salt;
1361 spin_unlock_bh(&ip_fb_id_lock);
1364 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1366 struct rtable *rt = (struct rtable *) dst;
1368 if (rt && !(rt->dst.flags & DST_NOPEER)) {
1369 struct inet_peer *peer = rt_get_peer_create(rt, rt->rt_dst);
1371 /* If peer is attached to destination, it is never detached,
1372 so that we need not to grab a lock to dereference it.
1375 iph->id = htons(inet_getid(peer, more));
1379 pr_debug("rt_bind_peer(0) @%p\n", __builtin_return_address(0));
1381 ip_select_fb_ident(iph);
1383 EXPORT_SYMBOL(__ip_select_ident);
1385 static void rt_del(unsigned int hash, struct rtable *rt)
1387 struct rtable __rcu **rthp;
1390 rthp = &rt_hash_table[hash].chain;
1391 spin_lock_bh(rt_hash_lock_addr(hash));
1393 while ((aux = rcu_dereference_protected(*rthp,
1394 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1395 if (aux == rt || rt_is_expired(aux)) {
1396 *rthp = aux->dst.rt_next;
1400 rthp = &aux->dst.rt_next;
1402 spin_unlock_bh(rt_hash_lock_addr(hash));
1405 static void check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1407 struct rtable *rt = (struct rtable *) dst;
1408 __be32 orig_gw = rt->rt_gateway;
1409 struct neighbour *n, *old_n;
1411 dst_confirm(&rt->dst);
1413 rt->rt_gateway = peer->redirect_learned.a4;
1415 n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
1417 rt->rt_gateway = orig_gw;
1420 old_n = xchg(&rt->dst._neighbour, n);
1422 neigh_release(old_n);
1423 if (!(n->nud_state & NUD_VALID)) {
1424 neigh_event_send(n, NULL);
1426 rt->rt_flags |= RTCF_REDIRECTED;
1427 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
1431 /* called in rcu_read_lock() section */
1432 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1433 __be32 saddr, struct net_device *dev)
1436 struct in_device *in_dev = __in_dev_get_rcu(dev);
1437 __be32 skeys[2] = { saddr, 0 };
1438 int ikeys[2] = { dev->ifindex, 0 };
1439 struct inet_peer *peer;
1446 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1447 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1448 ipv4_is_zeronet(new_gw))
1449 goto reject_redirect;
1451 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1452 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1453 goto reject_redirect;
1454 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1455 goto reject_redirect;
1457 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1458 goto reject_redirect;
1461 for (s = 0; s < 2; s++) {
1462 for (i = 0; i < 2; i++) {
1464 struct rtable __rcu **rthp;
1467 hash = rt_hash(daddr, skeys[s], ikeys[i], rt_genid(net));
1469 rthp = &rt_hash_table[hash].chain;
1471 while ((rt = rcu_dereference(*rthp)) != NULL) {
1472 rthp = &rt->dst.rt_next;
1474 if (rt->rt_key_dst != daddr ||
1475 rt->rt_key_src != skeys[s] ||
1476 rt->rt_oif != ikeys[i] ||
1477 rt_is_input_route(rt) ||
1478 rt_is_expired(rt) ||
1479 !net_eq(dev_net(rt->dst.dev), net) ||
1481 rt->dst.dev != dev ||
1482 rt->rt_gateway != old_gw)
1485 peer = rt_get_peer_create(rt, rt->rt_dst);
1487 if (peer->redirect_learned.a4 != new_gw) {
1488 peer->redirect_learned.a4 = new_gw;
1489 atomic_inc(&__rt_peer_genid);
1491 check_peer_redir(&rt->dst, peer);
1499 #ifdef CONFIG_IP_ROUTE_VERBOSE
1500 if (IN_DEV_LOG_MARTIANS(in_dev))
1501 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
1502 " Advised path = %pI4 -> %pI4\n",
1503 &old_gw, dev->name, &new_gw,
1509 static bool peer_pmtu_expired(struct inet_peer *peer)
1511 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1514 time_after_eq(jiffies, orig) &&
1515 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1518 static bool peer_pmtu_cleaned(struct inet_peer *peer)
1520 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1523 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1526 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1528 struct rtable *rt = (struct rtable *)dst;
1529 struct dst_entry *ret = dst;
1532 if (dst->obsolete > 0) {
1535 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1536 unsigned int hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1538 rt_genid(dev_net(dst->dev)));
1541 } else if (rt_has_peer(rt)) {
1542 struct inet_peer *peer = rt_peer_ptr(rt);
1543 if (peer_pmtu_expired(peer))
1544 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1552 * 1. The first ip_rt_redirect_number redirects are sent
1553 * with exponential backoff, then we stop sending them at all,
1554 * assuming that the host ignores our redirects.
1555 * 2. If we did not see packets requiring redirects
1556 * during ip_rt_redirect_silence, we assume that the host
1557 * forgot redirected route and start to send redirects again.
1559 * This algorithm is much cheaper and more intelligent than dumb load limiting
1562 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1563 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1566 void ip_rt_send_redirect(struct sk_buff *skb)
1568 struct rtable *rt = skb_rtable(skb);
1569 struct in_device *in_dev;
1570 struct inet_peer *peer;
1574 in_dev = __in_dev_get_rcu(rt->dst.dev);
1575 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1579 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1582 peer = rt_get_peer_create(rt, rt->rt_dst);
1584 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1588 /* No redirected packets during ip_rt_redirect_silence;
1589 * reset the algorithm.
1591 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1592 peer->rate_tokens = 0;
1594 /* Too many ignored redirects; do not send anything
1595 * set dst.rate_last to the last seen redirected packet.
1597 if (peer->rate_tokens >= ip_rt_redirect_number) {
1598 peer->rate_last = jiffies;
1602 /* Check for load limit; set rate_last to the latest sent
1605 if (peer->rate_tokens == 0 ||
1608 (ip_rt_redirect_load << peer->rate_tokens)))) {
1609 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1610 peer->rate_last = jiffies;
1611 ++peer->rate_tokens;
1612 #ifdef CONFIG_IP_ROUTE_VERBOSE
1614 peer->rate_tokens == ip_rt_redirect_number)
1615 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
1616 &ip_hdr(skb)->saddr, rt->rt_iif,
1617 &rt->rt_dst, &rt->rt_gateway);
1622 static int ip_error(struct sk_buff *skb)
1624 struct rtable *rt = skb_rtable(skb);
1625 struct inet_peer *peer;
1630 switch (rt->dst.error) {
1635 code = ICMP_HOST_UNREACH;
1638 code = ICMP_NET_UNREACH;
1639 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1640 IPSTATS_MIB_INNOROUTES);
1643 code = ICMP_PKT_FILTERED;
1647 peer = rt_get_peer_create(rt, rt->rt_dst);
1652 peer->rate_tokens += now - peer->rate_last;
1653 if (peer->rate_tokens > ip_rt_error_burst)
1654 peer->rate_tokens = ip_rt_error_burst;
1655 peer->rate_last = now;
1656 if (peer->rate_tokens >= ip_rt_error_cost)
1657 peer->rate_tokens -= ip_rt_error_cost;
1662 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1664 out: kfree_skb(skb);
1668 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1670 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires);
1674 if (time_before(jiffies, expires)) {
1675 u32 orig_dst_mtu = dst_mtu(dst);
1676 if (peer->pmtu_learned < orig_dst_mtu) {
1677 if (!peer->pmtu_orig)
1678 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1679 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1681 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1682 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1685 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1687 struct rtable *rt = (struct rtable *) dst;
1688 struct inet_peer *peer;
1692 peer = rt_get_peer_create(rt, rt->rt_dst);
1694 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires);
1696 if (mtu < ip_rt_min_pmtu)
1697 mtu = ip_rt_min_pmtu;
1698 if (!pmtu_expires || mtu < peer->pmtu_learned) {
1700 pmtu_expires = jiffies + ip_rt_mtu_expires;
1704 peer->pmtu_learned = mtu;
1705 peer->pmtu_expires = pmtu_expires;
1707 atomic_inc(&__rt_peer_genid);
1708 rt->rt_peer_genid = rt_peer_genid();
1710 check_peer_pmtu(dst, peer);
1714 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1715 int oif, u32 mark, u8 protocol, int flow_flags)
1717 const struct iphdr *iph = (const struct iphdr *)skb->data;
1721 flowi4_init_output(&fl4, oif, mark, RT_TOS(iph->tos), RT_SCOPE_UNIVERSE,
1722 protocol, flow_flags | FLOWI_FLAG_PRECOW_METRICS,
1723 iph->daddr, iph->saddr, 0, 0);
1724 rt = __ip_route_output_key(net, &fl4);
1726 ip_rt_update_pmtu(&rt->dst, mtu);
1730 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1732 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1734 const struct inet_sock *inet = inet_sk(sk);
1736 return ipv4_update_pmtu(skb, sock_net(sk), mtu,
1737 sk->sk_bound_dev_if, sk->sk_mark,
1738 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
1739 inet_sk_flowi_flags(sk));
1741 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1743 static void ipv4_validate_peer(struct rtable *rt)
1745 if (rt->rt_peer_genid != rt_peer_genid()) {
1746 struct inet_peer *peer = rt_get_peer(rt, rt->rt_dst);
1749 check_peer_pmtu(&rt->dst, peer);
1751 if (peer->redirect_learned.a4 &&
1752 peer->redirect_learned.a4 != rt->rt_gateway)
1753 check_peer_redir(&rt->dst, peer);
1756 rt->rt_peer_genid = rt_peer_genid();
1760 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1762 struct rtable *rt = (struct rtable *) dst;
1764 if (rt_is_expired(rt))
1766 ipv4_validate_peer(rt);
1770 static void ipv4_dst_destroy(struct dst_entry *dst)
1772 struct rtable *rt = (struct rtable *) dst;
1775 fib_info_put(rt->fi);
1778 if (rt_has_peer(rt)) {
1779 struct inet_peer *peer = rt_peer_ptr(rt);
1785 static void ipv4_link_failure(struct sk_buff *skb)
1789 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1791 rt = skb_rtable(skb);
1792 if (rt && rt_has_peer(rt)) {
1793 struct inet_peer *peer = rt_peer_ptr(rt);
1794 if (peer_pmtu_cleaned(peer))
1795 dst_metric_set(&rt->dst, RTAX_MTU, peer->pmtu_orig);
1799 static int ip_rt_bug(struct sk_buff *skb)
1801 pr_debug("%s: %pI4 -> %pI4, %s\n",
1802 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1803 skb->dev ? skb->dev->name : "?");
1810 We do not cache source address of outgoing interface,
1811 because it is used only by IP RR, TS and SRR options,
1812 so that it out of fast path.
1814 BTW remember: "addr" is allowed to be not aligned
1818 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1822 if (rt_is_output_route(rt))
1823 src = ip_hdr(skb)->saddr;
1825 struct fib_result res;
1831 memset(&fl4, 0, sizeof(fl4));
1832 fl4.daddr = iph->daddr;
1833 fl4.saddr = iph->saddr;
1834 fl4.flowi4_tos = RT_TOS(iph->tos);
1835 fl4.flowi4_oif = rt->dst.dev->ifindex;
1836 fl4.flowi4_iif = skb->dev->ifindex;
1837 fl4.flowi4_mark = skb->mark;
1840 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1841 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1843 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1847 memcpy(addr, &src, 4);
1850 #ifdef CONFIG_IP_ROUTE_CLASSID
1851 static void set_class_tag(struct rtable *rt, u32 tag)
1853 if (!(rt->dst.tclassid & 0xFFFF))
1854 rt->dst.tclassid |= tag & 0xFFFF;
1855 if (!(rt->dst.tclassid & 0xFFFF0000))
1856 rt->dst.tclassid |= tag & 0xFFFF0000;
1860 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1862 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1865 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1867 if (advmss > 65535 - 40)
1868 advmss = 65535 - 40;
1873 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1875 const struct rtable *rt = (const struct rtable *) dst;
1876 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
1878 if (mtu && rt_is_output_route(rt))
1881 mtu = dst->dev->mtu;
1883 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1885 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1889 if (mtu > IP_MAX_MTU)
1895 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1896 struct fib_info *fi)
1898 struct inet_peer_base *base;
1899 struct inet_peer *peer;
1902 /* If a peer entry exists for this destination, we must hook
1903 * it up in order to get at cached metrics.
1905 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1908 base = inetpeer_base_ptr(rt->_peer);
1911 peer = inet_getpeer_v4(base, rt->rt_dst, create);
1913 __rt_set_peer(rt, peer);
1914 rt->rt_peer_genid = rt_peer_genid();
1915 if (inet_metrics_new(peer))
1916 memcpy(peer->metrics, fi->fib_metrics,
1917 sizeof(u32) * RTAX_MAX);
1918 dst_init_metrics(&rt->dst, peer->metrics, false);
1920 check_peer_pmtu(&rt->dst, peer);
1922 if (peer->redirect_learned.a4 &&
1923 peer->redirect_learned.a4 != rt->rt_gateway) {
1924 rt->rt_gateway = peer->redirect_learned.a4;
1925 rt->rt_flags |= RTCF_REDIRECTED;
1928 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1930 atomic_inc(&fi->fib_clntref);
1932 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1936 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1937 const struct fib_result *res,
1938 struct fib_info *fi, u16 type, u32 itag)
1940 struct dst_entry *dst = &rt->dst;
1943 if (FIB_RES_GW(*res) &&
1944 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1945 rt->rt_gateway = FIB_RES_GW(*res);
1946 rt_init_metrics(rt, fl4, fi);
1947 #ifdef CONFIG_IP_ROUTE_CLASSID
1948 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1952 if (dst_mtu(dst) > IP_MAX_MTU)
1953 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1954 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1955 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1957 #ifdef CONFIG_IP_ROUTE_CLASSID
1958 #ifdef CONFIG_IP_MULTIPLE_TABLES
1959 set_class_tag(rt, fib_rules_tclass(res));
1961 set_class_tag(rt, itag);
1965 static struct rtable *rt_dst_alloc(struct net_device *dev,
1966 bool nopolicy, bool noxfrm)
1968 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
1970 (nopolicy ? DST_NOPOLICY : 0) |
1971 (noxfrm ? DST_NOXFRM : 0));
1974 /* called in rcu_read_lock() section */
1975 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1976 u8 tos, struct net_device *dev, int our)
1981 struct in_device *in_dev = __in_dev_get_rcu(dev);
1985 /* Primary sanity checks. */
1990 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1991 skb->protocol != htons(ETH_P_IP))
1994 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1995 if (ipv4_is_loopback(saddr))
1998 if (ipv4_is_zeronet(saddr)) {
1999 if (!ipv4_is_local_multicast(daddr))
2001 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2003 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2008 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
2009 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2013 #ifdef CONFIG_IP_ROUTE_CLASSID
2014 rth->dst.tclassid = itag;
2016 rth->dst.output = ip_rt_bug;
2018 rth->rt_key_dst = daddr;
2019 rth->rt_key_src = saddr;
2020 rth->rt_genid = rt_genid(dev_net(dev));
2021 rth->rt_flags = RTCF_MULTICAST;
2022 rth->rt_type = RTN_MULTICAST;
2023 rth->rt_key_tos = tos;
2024 rth->rt_dst = daddr;
2025 rth->rt_src = saddr;
2026 rth->rt_route_iif = dev->ifindex;
2027 rth->rt_iif = dev->ifindex;
2029 rth->rt_mark = skb->mark;
2030 rth->rt_gateway = daddr;
2031 rth->rt_spec_dst= spec_dst;
2032 rth->rt_peer_genid = 0;
2033 rt_init_peer(rth, dev_net(dev)->ipv4.peers);
2036 rth->dst.input= ip_local_deliver;
2037 rth->rt_flags |= RTCF_LOCAL;
2040 #ifdef CONFIG_IP_MROUTE
2041 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
2042 rth->dst.input = ip_mr_input;
2044 RT_CACHE_STAT_INC(in_slow_mc);
2046 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
2047 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
2048 return IS_ERR(rth) ? PTR_ERR(rth) : 0;
2059 static void ip_handle_martian_source(struct net_device *dev,
2060 struct in_device *in_dev,
2061 struct sk_buff *skb,
2065 RT_CACHE_STAT_INC(in_martian_src);
2066 #ifdef CONFIG_IP_ROUTE_VERBOSE
2067 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
2069 * RFC1812 recommendation, if source is martian,
2070 * the only hint is MAC header.
2072 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
2073 &daddr, &saddr, dev->name);
2074 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
2075 print_hex_dump(KERN_WARNING, "ll header: ",
2076 DUMP_PREFIX_OFFSET, 16, 1,
2077 skb_mac_header(skb),
2078 dev->hard_header_len, true);
2084 /* called in rcu_read_lock() section */
2085 static int __mkroute_input(struct sk_buff *skb,
2086 const struct fib_result *res,
2087 struct in_device *in_dev,
2088 __be32 daddr, __be32 saddr, u32 tos,
2089 struct rtable **result)
2093 struct in_device *out_dev;
2094 unsigned int flags = 0;
2098 /* get a working reference to the output device */
2099 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
2100 if (out_dev == NULL) {
2101 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
2106 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
2107 in_dev->dev, &spec_dst, &itag);
2109 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2116 flags |= RTCF_DIRECTSRC;
2118 if (out_dev == in_dev && err &&
2119 (IN_DEV_SHARED_MEDIA(out_dev) ||
2120 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2121 flags |= RTCF_DOREDIRECT;
2123 if (skb->protocol != htons(ETH_P_IP)) {
2124 /* Not IP (i.e. ARP). Do not create route, if it is
2125 * invalid for proxy arp. DNAT routes are always valid.
2127 * Proxy arp feature have been extended to allow, ARP
2128 * replies back to the same interface, to support
2129 * Private VLAN switch technologies. See arp.c.
2131 if (out_dev == in_dev &&
2132 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2138 rth = rt_dst_alloc(out_dev->dev,
2139 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2140 IN_DEV_CONF_GET(out_dev, NOXFRM));
2146 rth->rt_key_dst = daddr;
2147 rth->rt_key_src = saddr;
2148 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2149 rth->rt_flags = flags;
2150 rth->rt_type = res->type;
2151 rth->rt_key_tos = tos;
2152 rth->rt_dst = daddr;
2153 rth->rt_src = saddr;
2154 rth->rt_route_iif = in_dev->dev->ifindex;
2155 rth->rt_iif = in_dev->dev->ifindex;
2157 rth->rt_mark = skb->mark;
2158 rth->rt_gateway = daddr;
2159 rth->rt_spec_dst= spec_dst;
2160 rth->rt_peer_genid = 0;
2161 rt_init_peer(rth, &res->table->tb_peers);
2164 rth->dst.input = ip_forward;
2165 rth->dst.output = ip_output;
2167 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2175 static int ip_mkroute_input(struct sk_buff *skb,
2176 struct fib_result *res,
2177 const struct flowi4 *fl4,
2178 struct in_device *in_dev,
2179 __be32 daddr, __be32 saddr, u32 tos)
2181 struct rtable *rth = NULL;
2185 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2186 if (res->fi && res->fi->fib_nhs > 1)
2187 fib_select_multipath(res);
2190 /* create a routing cache entry */
2191 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2195 /* put it into the cache */
2196 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2197 rt_genid(dev_net(rth->dst.dev)));
2198 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2200 return PTR_ERR(rth);
2205 * NOTE. We drop all the packets that has local source
2206 * addresses, because every properly looped back packet
2207 * must have correct destination already attached by output routine.
2209 * Such approach solves two big problems:
2210 * 1. Not simplex devices are handled properly.
2211 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2212 * called with rcu_read_lock()
2215 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2216 u8 tos, struct net_device *dev)
2218 struct fib_result res;
2219 struct in_device *in_dev = __in_dev_get_rcu(dev);
2221 unsigned int flags = 0;
2227 struct net *net = dev_net(dev);
2229 /* IP on this device is disabled. */
2234 /* Check for the most weird martians, which can be not detected
2238 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
2239 goto martian_source;
2241 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2244 /* Accept zero addresses only to limited broadcast;
2245 * I even do not know to fix it or not. Waiting for complains :-)
2247 if (ipv4_is_zeronet(saddr))
2248 goto martian_source;
2250 if (ipv4_is_zeronet(daddr))
2251 goto martian_destination;
2253 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) {
2254 if (ipv4_is_loopback(daddr))
2255 goto martian_destination;
2257 if (ipv4_is_loopback(saddr))
2258 goto martian_source;
2262 * Now we are ready to route packet.
2265 fl4.flowi4_iif = dev->ifindex;
2266 fl4.flowi4_mark = skb->mark;
2267 fl4.flowi4_tos = tos;
2268 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2271 err = fib_lookup(net, &fl4, &res);
2273 if (!IN_DEV_FORWARD(in_dev))
2278 RT_CACHE_STAT_INC(in_slow_tot);
2280 if (res.type == RTN_BROADCAST)
2283 if (res.type == RTN_LOCAL) {
2284 err = fib_validate_source(skb, saddr, daddr, tos,
2285 net->loopback_dev->ifindex,
2286 dev, &spec_dst, &itag);
2288 goto martian_source_keep_err;
2290 flags |= RTCF_DIRECTSRC;
2295 if (!IN_DEV_FORWARD(in_dev))
2297 if (res.type != RTN_UNICAST)
2298 goto martian_destination;
2300 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2304 if (skb->protocol != htons(ETH_P_IP))
2307 if (ipv4_is_zeronet(saddr))
2308 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2310 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2313 goto martian_source_keep_err;
2315 flags |= RTCF_DIRECTSRC;
2317 flags |= RTCF_BROADCAST;
2318 res.type = RTN_BROADCAST;
2319 RT_CACHE_STAT_INC(in_brd);
2322 rth = rt_dst_alloc(net->loopback_dev,
2323 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2327 rth->dst.input= ip_local_deliver;
2328 rth->dst.output= ip_rt_bug;
2329 #ifdef CONFIG_IP_ROUTE_CLASSID
2330 rth->dst.tclassid = itag;
2333 rth->rt_key_dst = daddr;
2334 rth->rt_key_src = saddr;
2335 rth->rt_genid = rt_genid(net);
2336 rth->rt_flags = flags|RTCF_LOCAL;
2337 rth->rt_type = res.type;
2338 rth->rt_key_tos = tos;
2339 rth->rt_dst = daddr;
2340 rth->rt_src = saddr;
2341 #ifdef CONFIG_IP_ROUTE_CLASSID
2342 rth->dst.tclassid = itag;
2344 rth->rt_route_iif = dev->ifindex;
2345 rth->rt_iif = dev->ifindex;
2347 rth->rt_mark = skb->mark;
2348 rth->rt_gateway = daddr;
2349 rth->rt_spec_dst= spec_dst;
2350 rth->rt_peer_genid = 0;
2351 rt_init_peer(rth, net->ipv4.peers);
2353 if (res.type == RTN_UNREACHABLE) {
2354 rth->dst.input= ip_error;
2355 rth->dst.error= -err;
2356 rth->rt_flags &= ~RTCF_LOCAL;
2358 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2359 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2366 RT_CACHE_STAT_INC(in_no_route);
2367 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2368 res.type = RTN_UNREACHABLE;
2374 * Do not cache martian addresses: they should be logged (RFC1812)
2376 martian_destination:
2377 RT_CACHE_STAT_INC(in_martian_dst);
2378 #ifdef CONFIG_IP_ROUTE_VERBOSE
2379 if (IN_DEV_LOG_MARTIANS(in_dev))
2380 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2381 &daddr, &saddr, dev->name);
2385 err = -EHOSTUNREACH;
2398 martian_source_keep_err:
2399 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2403 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2404 u8 tos, struct net_device *dev, bool noref)
2408 int iif = dev->ifindex;
2416 if (!rt_caching(net))
2419 tos &= IPTOS_RT_MASK;
2420 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2422 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2423 rth = rcu_dereference(rth->dst.rt_next)) {
2424 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2425 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2426 (rth->rt_route_iif ^ iif) |
2427 (rth->rt_key_tos ^ tos)) == 0 &&
2428 rth->rt_mark == skb->mark &&
2429 net_eq(dev_net(rth->dst.dev), net) &&
2430 !rt_is_expired(rth)) {
2431 ipv4_validate_peer(rth);
2433 dst_use_noref(&rth->dst, jiffies);
2434 skb_dst_set_noref(skb, &rth->dst);
2436 dst_use(&rth->dst, jiffies);
2437 skb_dst_set(skb, &rth->dst);
2439 RT_CACHE_STAT_INC(in_hit);
2443 RT_CACHE_STAT_INC(in_hlist_search);
2447 /* Multicast recognition logic is moved from route cache to here.
2448 The problem was that too many Ethernet cards have broken/missing
2449 hardware multicast filters :-( As result the host on multicasting
2450 network acquires a lot of useless route cache entries, sort of
2451 SDR messages from all the world. Now we try to get rid of them.
2452 Really, provided software IP multicast filter is organized
2453 reasonably (at least, hashed), it does not result in a slowdown
2454 comparing with route cache reject entries.
2455 Note, that multicast routers are not affected, because
2456 route cache entry is created eventually.
2458 if (ipv4_is_multicast(daddr)) {
2459 struct in_device *in_dev = __in_dev_get_rcu(dev);
2462 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2463 ip_hdr(skb)->protocol);
2465 #ifdef CONFIG_IP_MROUTE
2467 (!ipv4_is_local_multicast(daddr) &&
2468 IN_DEV_MFORWARD(in_dev))
2471 int res = ip_route_input_mc(skb, daddr, saddr,
2480 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2484 EXPORT_SYMBOL(ip_route_input_common);
2486 /* called with rcu_read_lock() */
2487 static struct rtable *__mkroute_output(const struct fib_result *res,
2488 const struct flowi4 *fl4,
2489 __be32 orig_daddr, __be32 orig_saddr,
2490 int orig_oif, __u8 orig_rtos,
2491 struct net_device *dev_out,
2494 struct fib_info *fi = res->fi;
2495 struct in_device *in_dev;
2496 u16 type = res->type;
2499 in_dev = __in_dev_get_rcu(dev_out);
2501 return ERR_PTR(-EINVAL);
2503 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2504 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2505 return ERR_PTR(-EINVAL);
2507 if (ipv4_is_lbcast(fl4->daddr))
2508 type = RTN_BROADCAST;
2509 else if (ipv4_is_multicast(fl4->daddr))
2510 type = RTN_MULTICAST;
2511 else if (ipv4_is_zeronet(fl4->daddr))
2512 return ERR_PTR(-EINVAL);
2514 if (dev_out->flags & IFF_LOOPBACK)
2515 flags |= RTCF_LOCAL;
2517 if (type == RTN_BROADCAST) {
2518 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2520 } else if (type == RTN_MULTICAST) {
2521 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2522 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2524 flags &= ~RTCF_LOCAL;
2525 /* If multicast route do not exist use
2526 * default one, but do not gateway in this case.
2529 if (fi && res->prefixlen < 4)
2533 rth = rt_dst_alloc(dev_out,
2534 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2535 IN_DEV_CONF_GET(in_dev, NOXFRM));
2537 return ERR_PTR(-ENOBUFS);
2539 rth->dst.output = ip_output;
2541 rth->rt_key_dst = orig_daddr;
2542 rth->rt_key_src = orig_saddr;
2543 rth->rt_genid = rt_genid(dev_net(dev_out));
2544 rth->rt_flags = flags;
2545 rth->rt_type = type;
2546 rth->rt_key_tos = orig_rtos;
2547 rth->rt_dst = fl4->daddr;
2548 rth->rt_src = fl4->saddr;
2549 rth->rt_route_iif = 0;
2550 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2551 rth->rt_oif = orig_oif;
2552 rth->rt_mark = fl4->flowi4_mark;
2553 rth->rt_gateway = fl4->daddr;
2554 rth->rt_spec_dst= fl4->saddr;
2555 rth->rt_peer_genid = 0;
2556 rt_init_peer(rth, (res->table ?
2557 &res->table->tb_peers :
2558 dev_net(dev_out)->ipv4.peers));
2561 RT_CACHE_STAT_INC(out_slow_tot);
2563 if (flags & RTCF_LOCAL) {
2564 rth->dst.input = ip_local_deliver;
2565 rth->rt_spec_dst = fl4->daddr;
2567 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2568 rth->rt_spec_dst = fl4->saddr;
2569 if (flags & RTCF_LOCAL &&
2570 !(dev_out->flags & IFF_LOOPBACK)) {
2571 rth->dst.output = ip_mc_output;
2572 RT_CACHE_STAT_INC(out_slow_mc);
2574 #ifdef CONFIG_IP_MROUTE
2575 if (type == RTN_MULTICAST) {
2576 if (IN_DEV_MFORWARD(in_dev) &&
2577 !ipv4_is_local_multicast(fl4->daddr)) {
2578 rth->dst.input = ip_mr_input;
2579 rth->dst.output = ip_mc_output;
2585 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2591 * Major route resolver routine.
2592 * called with rcu_read_lock();
2595 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2597 struct net_device *dev_out = NULL;
2598 __u8 tos = RT_FL_TOS(fl4);
2599 unsigned int flags = 0;
2600 struct fib_result res;
2608 #ifdef CONFIG_IP_MULTIPLE_TABLES
2612 orig_daddr = fl4->daddr;
2613 orig_saddr = fl4->saddr;
2614 orig_oif = fl4->flowi4_oif;
2616 fl4->flowi4_iif = net->loopback_dev->ifindex;
2617 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2618 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2619 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2623 rth = ERR_PTR(-EINVAL);
2624 if (ipv4_is_multicast(fl4->saddr) ||
2625 ipv4_is_lbcast(fl4->saddr) ||
2626 ipv4_is_zeronet(fl4->saddr))
2629 /* I removed check for oif == dev_out->oif here.
2630 It was wrong for two reasons:
2631 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2632 is assigned to multiple interfaces.
2633 2. Moreover, we are allowed to send packets with saddr
2634 of another iface. --ANK
2637 if (fl4->flowi4_oif == 0 &&
2638 (ipv4_is_multicast(fl4->daddr) ||
2639 ipv4_is_lbcast(fl4->daddr))) {
2640 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2641 dev_out = __ip_dev_find(net, fl4->saddr, false);
2642 if (dev_out == NULL)
2645 /* Special hack: user can direct multicasts
2646 and limited broadcast via necessary interface
2647 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2648 This hack is not just for fun, it allows
2649 vic,vat and friends to work.
2650 They bind socket to loopback, set ttl to zero
2651 and expect that it will work.
2652 From the viewpoint of routing cache they are broken,
2653 because we are not allowed to build multicast path
2654 with loopback source addr (look, routing cache
2655 cannot know, that ttl is zero, so that packet
2656 will not leave this host and route is valid).
2657 Luckily, this hack is good workaround.
2660 fl4->flowi4_oif = dev_out->ifindex;
2664 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2665 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2666 if (!__ip_dev_find(net, fl4->saddr, false))
2672 if (fl4->flowi4_oif) {
2673 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2674 rth = ERR_PTR(-ENODEV);
2675 if (dev_out == NULL)
2678 /* RACE: Check return value of inet_select_addr instead. */
2679 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2680 rth = ERR_PTR(-ENETUNREACH);
2683 if (ipv4_is_local_multicast(fl4->daddr) ||
2684 ipv4_is_lbcast(fl4->daddr)) {
2686 fl4->saddr = inet_select_addr(dev_out, 0,
2691 if (ipv4_is_multicast(fl4->daddr))
2692 fl4->saddr = inet_select_addr(dev_out, 0,
2694 else if (!fl4->daddr)
2695 fl4->saddr = inet_select_addr(dev_out, 0,
2701 fl4->daddr = fl4->saddr;
2703 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2704 dev_out = net->loopback_dev;
2705 fl4->flowi4_oif = net->loopback_dev->ifindex;
2706 res.type = RTN_LOCAL;
2707 flags |= RTCF_LOCAL;
2711 if (fib_lookup(net, fl4, &res)) {
2714 if (fl4->flowi4_oif) {
2715 /* Apparently, routing tables are wrong. Assume,
2716 that the destination is on link.
2719 Because we are allowed to send to iface
2720 even if it has NO routes and NO assigned
2721 addresses. When oif is specified, routing
2722 tables are looked up with only one purpose:
2723 to catch if destination is gatewayed, rather than
2724 direct. Moreover, if MSG_DONTROUTE is set,
2725 we send packet, ignoring both routing tables
2726 and ifaddr state. --ANK
2729 We could make it even if oif is unknown,
2730 likely IPv6, but we do not.
2733 if (fl4->saddr == 0)
2734 fl4->saddr = inet_select_addr(dev_out, 0,
2736 res.type = RTN_UNICAST;
2739 rth = ERR_PTR(-ENETUNREACH);
2743 if (res.type == RTN_LOCAL) {
2745 if (res.fi->fib_prefsrc)
2746 fl4->saddr = res.fi->fib_prefsrc;
2748 fl4->saddr = fl4->daddr;
2750 dev_out = net->loopback_dev;
2751 fl4->flowi4_oif = dev_out->ifindex;
2753 flags |= RTCF_LOCAL;
2757 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2758 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2759 fib_select_multipath(&res);
2762 if (!res.prefixlen &&
2763 res.table->tb_num_default > 1 &&
2764 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2765 fib_select_default(&res);
2768 fl4->saddr = FIB_RES_PREFSRC(net, res);
2770 dev_out = FIB_RES_DEV(res);
2771 fl4->flowi4_oif = dev_out->ifindex;
2775 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2776 tos, dev_out, flags);
2780 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2781 rt_genid(dev_net(dev_out)));
2782 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2790 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2795 if (!rt_caching(net))
2798 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2801 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2802 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2803 if (rth->rt_key_dst == flp4->daddr &&
2804 rth->rt_key_src == flp4->saddr &&
2805 rt_is_output_route(rth) &&
2806 rth->rt_oif == flp4->flowi4_oif &&
2807 rth->rt_mark == flp4->flowi4_mark &&
2808 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2809 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2810 net_eq(dev_net(rth->dst.dev), net) &&
2811 !rt_is_expired(rth)) {
2812 ipv4_validate_peer(rth);
2813 dst_use(&rth->dst, jiffies);
2814 RT_CACHE_STAT_INC(out_hit);
2815 rcu_read_unlock_bh();
2817 flp4->saddr = rth->rt_src;
2819 flp4->daddr = rth->rt_dst;
2822 RT_CACHE_STAT_INC(out_hlist_search);
2824 rcu_read_unlock_bh();
2827 return ip_route_output_slow(net, flp4);
2829 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2831 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2836 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2838 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2840 return mtu ? : dst->dev->mtu;
2843 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2847 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2853 static struct dst_ops ipv4_dst_blackhole_ops = {
2855 .protocol = cpu_to_be16(ETH_P_IP),
2856 .destroy = ipv4_dst_destroy,
2857 .check = ipv4_blackhole_dst_check,
2858 .mtu = ipv4_blackhole_mtu,
2859 .default_advmss = ipv4_default_advmss,
2860 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2861 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2862 .neigh_lookup = ipv4_neigh_lookup,
2865 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2867 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2868 struct rtable *ort = (struct rtable *) dst_orig;
2871 struct dst_entry *new = &rt->dst;
2874 new->input = dst_discard;
2875 new->output = dst_discard;
2876 dst_copy_metrics(new, &ort->dst);
2878 new->dev = ort->dst.dev;
2882 rt->rt_key_dst = ort->rt_key_dst;
2883 rt->rt_key_src = ort->rt_key_src;
2884 rt->rt_key_tos = ort->rt_key_tos;
2885 rt->rt_route_iif = ort->rt_route_iif;
2886 rt->rt_iif = ort->rt_iif;
2887 rt->rt_oif = ort->rt_oif;
2888 rt->rt_mark = ort->rt_mark;
2890 rt->rt_genid = rt_genid(net);
2891 rt->rt_flags = ort->rt_flags;
2892 rt->rt_type = ort->rt_type;
2893 rt->rt_dst = ort->rt_dst;
2894 rt->rt_src = ort->rt_src;
2895 rt->rt_gateway = ort->rt_gateway;
2896 rt->rt_spec_dst = ort->rt_spec_dst;
2897 rt_transfer_peer(rt, ort);
2900 atomic_inc(&rt->fi->fib_clntref);
2905 dst_release(dst_orig);
2907 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2910 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2913 struct rtable *rt = __ip_route_output_key(net, flp4);
2918 if (flp4->flowi4_proto)
2919 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2920 flowi4_to_flowi(flp4),
2925 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2927 static int rt_fill_info(struct net *net,
2928 struct sk_buff *skb, u32 pid, u32 seq, int event,
2929 int nowait, unsigned int flags)
2931 struct rtable *rt = skb_rtable(skb);
2933 struct nlmsghdr *nlh;
2934 unsigned long expires = 0;
2935 u32 id = 0, ts = 0, tsage = 0, error;
2937 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2941 r = nlmsg_data(nlh);
2942 r->rtm_family = AF_INET;
2943 r->rtm_dst_len = 32;
2945 r->rtm_tos = rt->rt_key_tos;
2946 r->rtm_table = RT_TABLE_MAIN;
2947 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2948 goto nla_put_failure;
2949 r->rtm_type = rt->rt_type;
2950 r->rtm_scope = RT_SCOPE_UNIVERSE;
2951 r->rtm_protocol = RTPROT_UNSPEC;
2952 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2953 if (rt->rt_flags & RTCF_NOTIFY)
2954 r->rtm_flags |= RTM_F_NOTIFY;
2956 if (nla_put_be32(skb, RTA_DST, rt->rt_dst))
2957 goto nla_put_failure;
2958 if (rt->rt_key_src) {
2959 r->rtm_src_len = 32;
2960 if (nla_put_be32(skb, RTA_SRC, rt->rt_key_src))
2961 goto nla_put_failure;
2964 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2965 goto nla_put_failure;
2966 #ifdef CONFIG_IP_ROUTE_CLASSID
2967 if (rt->dst.tclassid &&
2968 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2969 goto nla_put_failure;
2971 if (rt_is_input_route(rt)) {
2972 if (nla_put_be32(skb, RTA_PREFSRC, rt->rt_spec_dst))
2973 goto nla_put_failure;
2974 } else if (rt->rt_src != rt->rt_key_src) {
2975 if (nla_put_be32(skb, RTA_PREFSRC, rt->rt_src))
2976 goto nla_put_failure;
2978 if (rt->rt_dst != rt->rt_gateway &&
2979 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2980 goto nla_put_failure;
2982 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2983 goto nla_put_failure;
2986 nla_put_be32(skb, RTA_MARK, rt->rt_mark))
2987 goto nla_put_failure;
2989 error = rt->dst.error;
2990 if (rt_has_peer(rt)) {
2991 const struct inet_peer *peer = rt_peer_ptr(rt);
2992 inet_peer_refcheck(peer);
2993 id = atomic_read(&peer->ip_id_count) & 0xffff;
2994 if (peer->tcp_ts_stamp) {
2996 tsage = get_seconds() - peer->tcp_ts_stamp;
2998 expires = ACCESS_ONCE(peer->pmtu_expires);
3000 if (time_before(jiffies, expires))
3007 if (rt_is_input_route(rt)) {
3008 #ifdef CONFIG_IP_MROUTE
3009 __be32 dst = rt->rt_dst;
3011 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
3012 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
3013 int err = ipmr_get_route(net, skb,
3014 rt->rt_src, rt->rt_dst,
3020 goto nla_put_failure;
3022 if (err == -EMSGSIZE)
3023 goto nla_put_failure;
3029 if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
3030 goto nla_put_failure;
3033 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
3034 expires, error) < 0)
3035 goto nla_put_failure;
3037 return nlmsg_end(skb, nlh);
3040 nlmsg_cancel(skb, nlh);
3044 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
3046 struct net *net = sock_net(in_skb->sk);
3048 struct nlattr *tb[RTA_MAX+1];
3049 struct rtable *rt = NULL;
3055 struct sk_buff *skb;
3057 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
3061 rtm = nlmsg_data(nlh);
3063 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3069 /* Reserve room for dummy headers, this skb can pass
3070 through good chunk of routing engine.
3072 skb_reset_mac_header(skb);
3073 skb_reset_network_header(skb);
3075 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
3076 ip_hdr(skb)->protocol = IPPROTO_ICMP;
3077 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
3079 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
3080 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
3081 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
3082 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
3085 struct net_device *dev;
3087 dev = __dev_get_by_index(net, iif);
3093 skb->protocol = htons(ETH_P_IP);
3097 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
3100 rt = skb_rtable(skb);
3101 if (err == 0 && rt->dst.error)
3102 err = -rt->dst.error;
3104 struct flowi4 fl4 = {
3107 .flowi4_tos = rtm->rtm_tos,
3108 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
3109 .flowi4_mark = mark,
3111 rt = ip_route_output_key(net, &fl4);
3121 skb_dst_set(skb, &rt->dst);
3122 if (rtm->rtm_flags & RTM_F_NOTIFY)
3123 rt->rt_flags |= RTCF_NOTIFY;
3125 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3126 RTM_NEWROUTE, 0, 0);
3130 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3139 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3146 net = sock_net(skb->sk);
3151 s_idx = idx = cb->args[1];
3152 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3153 if (!rt_hash_table[h].chain)
3156 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3157 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3158 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3160 if (rt_is_expired(rt))
3162 skb_dst_set_noref(skb, &rt->dst);
3163 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3164 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3165 1, NLM_F_MULTI) <= 0) {
3167 rcu_read_unlock_bh();
3172 rcu_read_unlock_bh();
3181 void ip_rt_multicast_event(struct in_device *in_dev)
3183 rt_cache_flush(dev_net(in_dev->dev), 0);
3186 #ifdef CONFIG_SYSCTL
3187 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3188 void __user *buffer,
3189 size_t *lenp, loff_t *ppos)
3196 memcpy(&ctl, __ctl, sizeof(ctl));
3197 ctl.data = &flush_delay;
3198 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3200 net = (struct net *)__ctl->extra1;
3201 rt_cache_flush(net, flush_delay);
3208 static ctl_table ipv4_route_table[] = {
3210 .procname = "gc_thresh",
3211 .data = &ipv4_dst_ops.gc_thresh,
3212 .maxlen = sizeof(int),
3214 .proc_handler = proc_dointvec,
3217 .procname = "max_size",
3218 .data = &ip_rt_max_size,
3219 .maxlen = sizeof(int),
3221 .proc_handler = proc_dointvec,
3224 /* Deprecated. Use gc_min_interval_ms */
3226 .procname = "gc_min_interval",
3227 .data = &ip_rt_gc_min_interval,
3228 .maxlen = sizeof(int),
3230 .proc_handler = proc_dointvec_jiffies,
3233 .procname = "gc_min_interval_ms",
3234 .data = &ip_rt_gc_min_interval,
3235 .maxlen = sizeof(int),
3237 .proc_handler = proc_dointvec_ms_jiffies,
3240 .procname = "gc_timeout",
3241 .data = &ip_rt_gc_timeout,
3242 .maxlen = sizeof(int),
3244 .proc_handler = proc_dointvec_jiffies,
3247 .procname = "gc_interval",
3248 .data = &ip_rt_gc_interval,
3249 .maxlen = sizeof(int),
3251 .proc_handler = proc_dointvec_jiffies,
3254 .procname = "redirect_load",
3255 .data = &ip_rt_redirect_load,
3256 .maxlen = sizeof(int),
3258 .proc_handler = proc_dointvec,
3261 .procname = "redirect_number",
3262 .data = &ip_rt_redirect_number,
3263 .maxlen = sizeof(int),
3265 .proc_handler = proc_dointvec,
3268 .procname = "redirect_silence",
3269 .data = &ip_rt_redirect_silence,
3270 .maxlen = sizeof(int),
3272 .proc_handler = proc_dointvec,
3275 .procname = "error_cost",
3276 .data = &ip_rt_error_cost,
3277 .maxlen = sizeof(int),
3279 .proc_handler = proc_dointvec,
3282 .procname = "error_burst",
3283 .data = &ip_rt_error_burst,
3284 .maxlen = sizeof(int),
3286 .proc_handler = proc_dointvec,
3289 .procname = "gc_elasticity",
3290 .data = &ip_rt_gc_elasticity,
3291 .maxlen = sizeof(int),
3293 .proc_handler = proc_dointvec,
3296 .procname = "mtu_expires",
3297 .data = &ip_rt_mtu_expires,
3298 .maxlen = sizeof(int),
3300 .proc_handler = proc_dointvec_jiffies,
3303 .procname = "min_pmtu",
3304 .data = &ip_rt_min_pmtu,
3305 .maxlen = sizeof(int),
3307 .proc_handler = proc_dointvec,
3310 .procname = "min_adv_mss",
3311 .data = &ip_rt_min_advmss,
3312 .maxlen = sizeof(int),
3314 .proc_handler = proc_dointvec,
3319 static struct ctl_table ipv4_route_flush_table[] = {
3321 .procname = "flush",
3322 .maxlen = sizeof(int),
3324 .proc_handler = ipv4_sysctl_rtcache_flush,
3329 static __net_init int sysctl_route_net_init(struct net *net)
3331 struct ctl_table *tbl;
3333 tbl = ipv4_route_flush_table;
3334 if (!net_eq(net, &init_net)) {
3335 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3339 tbl[0].extra1 = net;
3341 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
3342 if (net->ipv4.route_hdr == NULL)
3347 if (tbl != ipv4_route_flush_table)
3353 static __net_exit void sysctl_route_net_exit(struct net *net)
3355 struct ctl_table *tbl;
3357 tbl = net->ipv4.route_hdr->ctl_table_arg;
3358 unregister_net_sysctl_table(net->ipv4.route_hdr);
3359 BUG_ON(tbl == ipv4_route_flush_table);
3363 static __net_initdata struct pernet_operations sysctl_route_ops = {
3364 .init = sysctl_route_net_init,
3365 .exit = sysctl_route_net_exit,
3369 static __net_init int rt_genid_init(struct net *net)
3371 get_random_bytes(&net->ipv4.rt_genid,
3372 sizeof(net->ipv4.rt_genid));
3373 get_random_bytes(&net->ipv4.dev_addr_genid,
3374 sizeof(net->ipv4.dev_addr_genid));
3378 static __net_initdata struct pernet_operations rt_genid_ops = {
3379 .init = rt_genid_init,
3382 static int __net_init ipv4_inetpeer_init(struct net *net)
3384 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3388 inet_peer_base_init(bp);
3389 net->ipv4.peers = bp;
3393 static void __net_exit ipv4_inetpeer_exit(struct net *net)
3395 struct inet_peer_base *bp = net->ipv4.peers;
3397 net->ipv4.peers = NULL;
3398 inetpeer_invalidate_tree(bp);
3402 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
3403 .init = ipv4_inetpeer_init,
3404 .exit = ipv4_inetpeer_exit,
3407 #ifdef CONFIG_IP_ROUTE_CLASSID
3408 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3409 #endif /* CONFIG_IP_ROUTE_CLASSID */
3411 static __initdata unsigned long rhash_entries;
3412 static int __init set_rhash_entries(char *str)
3419 ret = kstrtoul(str, 0, &rhash_entries);
3425 __setup("rhash_entries=", set_rhash_entries);
3427 int __init ip_rt_init(void)
3431 #ifdef CONFIG_IP_ROUTE_CLASSID
3432 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3434 panic("IP: failed to allocate ip_rt_acct\n");
3437 ipv4_dst_ops.kmem_cachep =
3438 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3439 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3441 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3443 if (dst_entries_init(&ipv4_dst_ops) < 0)
3444 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3446 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3447 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3449 rt_hash_table = (struct rt_hash_bucket *)
3450 alloc_large_system_hash("IP route cache",
3451 sizeof(struct rt_hash_bucket),
3453 (totalram_pages >= 128 * 1024) ?
3459 rhash_entries ? 0 : 512 * 1024);
3460 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3461 rt_hash_lock_init();
3463 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3464 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3469 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func);
3470 expires_ljiffies = jiffies;
3471 schedule_delayed_work(&expires_work,
3472 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3474 if (ip_rt_proc_init())
3475 pr_err("Unable to create route proc files\n");
3478 xfrm4_init(ip_rt_max_size);
3480 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
3482 #ifdef CONFIG_SYSCTL
3483 register_pernet_subsys(&sysctl_route_ops);
3485 register_pernet_subsys(&rt_genid_ops);
3486 register_pernet_subsys(&ipv4_inetpeer_ops);
3490 #ifdef CONFIG_SYSCTL
3492 * We really need to sanitize the damn ipv4 init order, then all
3493 * this nonsense will go away.
3495 void __init ip_static_sysctl_init(void)
3497 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);