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_tree(net->ipv4.peers);
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();
1344 * Peer allocation may fail only in serious out-of-memory conditions. However
1345 * we still can generate some output.
1346 * Random ID selection looks a bit dangerous because we have no chances to
1347 * select ID being unique in a reasonable period of time.
1348 * But broken packet identifier may be better than no packet at all.
1350 static void ip_select_fb_ident(struct iphdr *iph)
1352 static DEFINE_SPINLOCK(ip_fb_id_lock);
1353 static u32 ip_fallback_id;
1356 spin_lock_bh(&ip_fb_id_lock);
1357 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1358 iph->id = htons(salt & 0xFFFF);
1359 ip_fallback_id = salt;
1360 spin_unlock_bh(&ip_fb_id_lock);
1363 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1365 struct rtable *rt = (struct rtable *) dst;
1367 if (rt && !(rt->dst.flags & DST_NOPEER)) {
1368 struct inet_peer *peer = rt_get_peer_create(rt, rt->rt_dst);
1370 /* If peer is attached to destination, it is never detached,
1371 so that we need not to grab a lock to dereference it.
1374 iph->id = htons(inet_getid(peer, more));
1378 pr_debug("rt_bind_peer(0) @%p\n", __builtin_return_address(0));
1380 ip_select_fb_ident(iph);
1382 EXPORT_SYMBOL(__ip_select_ident);
1384 static void rt_del(unsigned int hash, struct rtable *rt)
1386 struct rtable __rcu **rthp;
1389 rthp = &rt_hash_table[hash].chain;
1390 spin_lock_bh(rt_hash_lock_addr(hash));
1392 while ((aux = rcu_dereference_protected(*rthp,
1393 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1394 if (aux == rt || rt_is_expired(aux)) {
1395 *rthp = aux->dst.rt_next;
1399 rthp = &aux->dst.rt_next;
1401 spin_unlock_bh(rt_hash_lock_addr(hash));
1404 static void check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1406 struct rtable *rt = (struct rtable *) dst;
1407 __be32 orig_gw = rt->rt_gateway;
1408 struct neighbour *n, *old_n;
1410 dst_confirm(&rt->dst);
1412 rt->rt_gateway = peer->redirect_learned.a4;
1414 n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
1416 rt->rt_gateway = orig_gw;
1419 old_n = xchg(&rt->dst._neighbour, n);
1421 neigh_release(old_n);
1422 if (!(n->nud_state & NUD_VALID)) {
1423 neigh_event_send(n, NULL);
1425 rt->rt_flags |= RTCF_REDIRECTED;
1426 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
1430 /* called in rcu_read_lock() section */
1431 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1432 __be32 saddr, struct net_device *dev)
1435 struct in_device *in_dev = __in_dev_get_rcu(dev);
1436 __be32 skeys[2] = { saddr, 0 };
1437 int ikeys[2] = { dev->ifindex, 0 };
1438 struct inet_peer *peer;
1445 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1446 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1447 ipv4_is_zeronet(new_gw))
1448 goto reject_redirect;
1450 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1451 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1452 goto reject_redirect;
1453 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1454 goto reject_redirect;
1456 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1457 goto reject_redirect;
1460 for (s = 0; s < 2; s++) {
1461 for (i = 0; i < 2; i++) {
1463 struct rtable __rcu **rthp;
1466 hash = rt_hash(daddr, skeys[s], ikeys[i], rt_genid(net));
1468 rthp = &rt_hash_table[hash].chain;
1470 while ((rt = rcu_dereference(*rthp)) != NULL) {
1471 rthp = &rt->dst.rt_next;
1473 if (rt->rt_key_dst != daddr ||
1474 rt->rt_key_src != skeys[s] ||
1475 rt->rt_oif != ikeys[i] ||
1476 rt_is_input_route(rt) ||
1477 rt_is_expired(rt) ||
1478 !net_eq(dev_net(rt->dst.dev), net) ||
1480 rt->dst.dev != dev ||
1481 rt->rt_gateway != old_gw)
1484 peer = rt_get_peer_create(rt, rt->rt_dst);
1486 if (peer->redirect_learned.a4 != new_gw) {
1487 peer->redirect_learned.a4 = new_gw;
1488 atomic_inc(&__rt_peer_genid);
1490 check_peer_redir(&rt->dst, peer);
1498 #ifdef CONFIG_IP_ROUTE_VERBOSE
1499 if (IN_DEV_LOG_MARTIANS(in_dev))
1500 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
1501 " Advised path = %pI4 -> %pI4\n",
1502 &old_gw, dev->name, &new_gw,
1508 static bool peer_pmtu_expired(struct inet_peer *peer)
1510 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1513 time_after_eq(jiffies, orig) &&
1514 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1517 static bool peer_pmtu_cleaned(struct inet_peer *peer)
1519 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1522 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1525 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1527 struct rtable *rt = (struct rtable *)dst;
1528 struct dst_entry *ret = dst;
1531 if (dst->obsolete > 0) {
1534 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1535 unsigned int hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1537 rt_genid(dev_net(dst->dev)));
1540 } else if (rt_has_peer(rt)) {
1541 struct inet_peer *peer = rt_peer_ptr(rt);
1542 if (peer_pmtu_expired(peer))
1543 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1551 * 1. The first ip_rt_redirect_number redirects are sent
1552 * with exponential backoff, then we stop sending them at all,
1553 * assuming that the host ignores our redirects.
1554 * 2. If we did not see packets requiring redirects
1555 * during ip_rt_redirect_silence, we assume that the host
1556 * forgot redirected route and start to send redirects again.
1558 * This algorithm is much cheaper and more intelligent than dumb load limiting
1561 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1562 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1565 void ip_rt_send_redirect(struct sk_buff *skb)
1567 struct rtable *rt = skb_rtable(skb);
1568 struct in_device *in_dev;
1569 struct inet_peer *peer;
1573 in_dev = __in_dev_get_rcu(rt->dst.dev);
1574 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1578 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1581 peer = rt_get_peer_create(rt, rt->rt_dst);
1583 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1587 /* No redirected packets during ip_rt_redirect_silence;
1588 * reset the algorithm.
1590 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1591 peer->rate_tokens = 0;
1593 /* Too many ignored redirects; do not send anything
1594 * set dst.rate_last to the last seen redirected packet.
1596 if (peer->rate_tokens >= ip_rt_redirect_number) {
1597 peer->rate_last = jiffies;
1601 /* Check for load limit; set rate_last to the latest sent
1604 if (peer->rate_tokens == 0 ||
1607 (ip_rt_redirect_load << peer->rate_tokens)))) {
1608 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1609 peer->rate_last = jiffies;
1610 ++peer->rate_tokens;
1611 #ifdef CONFIG_IP_ROUTE_VERBOSE
1613 peer->rate_tokens == ip_rt_redirect_number)
1614 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
1615 &ip_hdr(skb)->saddr, rt->rt_iif,
1616 &rt->rt_dst, &rt->rt_gateway);
1621 static int ip_error(struct sk_buff *skb)
1623 struct rtable *rt = skb_rtable(skb);
1624 struct inet_peer *peer;
1629 switch (rt->dst.error) {
1634 code = ICMP_HOST_UNREACH;
1637 code = ICMP_NET_UNREACH;
1638 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1639 IPSTATS_MIB_INNOROUTES);
1642 code = ICMP_PKT_FILTERED;
1646 peer = rt_get_peer_create(rt, rt->rt_dst);
1651 peer->rate_tokens += now - peer->rate_last;
1652 if (peer->rate_tokens > ip_rt_error_burst)
1653 peer->rate_tokens = ip_rt_error_burst;
1654 peer->rate_last = now;
1655 if (peer->rate_tokens >= ip_rt_error_cost)
1656 peer->rate_tokens -= ip_rt_error_cost;
1661 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1663 out: kfree_skb(skb);
1667 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1669 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires);
1673 if (time_before(jiffies, expires)) {
1674 u32 orig_dst_mtu = dst_mtu(dst);
1675 if (peer->pmtu_learned < orig_dst_mtu) {
1676 if (!peer->pmtu_orig)
1677 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1678 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1680 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1681 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1684 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1686 struct rtable *rt = (struct rtable *) dst;
1687 struct inet_peer *peer;
1691 peer = rt_get_peer_create(rt, rt->rt_dst);
1693 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires);
1695 if (mtu < ip_rt_min_pmtu)
1696 mtu = ip_rt_min_pmtu;
1697 if (!pmtu_expires || mtu < peer->pmtu_learned) {
1699 pmtu_expires = jiffies + ip_rt_mtu_expires;
1703 peer->pmtu_learned = mtu;
1704 peer->pmtu_expires = pmtu_expires;
1706 atomic_inc(&__rt_peer_genid);
1707 rt->rt_peer_genid = rt_peer_genid();
1709 check_peer_pmtu(dst, peer);
1714 static void ipv4_validate_peer(struct rtable *rt)
1716 if (rt->rt_peer_genid != rt_peer_genid()) {
1717 struct inet_peer *peer = rt_get_peer(rt, rt->rt_dst);
1720 check_peer_pmtu(&rt->dst, peer);
1722 if (peer->redirect_learned.a4 &&
1723 peer->redirect_learned.a4 != rt->rt_gateway)
1724 check_peer_redir(&rt->dst, peer);
1727 rt->rt_peer_genid = rt_peer_genid();
1731 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1733 struct rtable *rt = (struct rtable *) dst;
1735 if (rt_is_expired(rt))
1737 ipv4_validate_peer(rt);
1741 static void ipv4_dst_destroy(struct dst_entry *dst)
1743 struct rtable *rt = (struct rtable *) dst;
1746 fib_info_put(rt->fi);
1749 if (rt_has_peer(rt)) {
1750 struct inet_peer *peer = rt_peer_ptr(rt);
1756 static void ipv4_link_failure(struct sk_buff *skb)
1760 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1762 rt = skb_rtable(skb);
1763 if (rt && rt_has_peer(rt)) {
1764 struct inet_peer *peer = rt_peer_ptr(rt);
1765 if (peer_pmtu_cleaned(peer))
1766 dst_metric_set(&rt->dst, RTAX_MTU, peer->pmtu_orig);
1770 static int ip_rt_bug(struct sk_buff *skb)
1772 pr_debug("%s: %pI4 -> %pI4, %s\n",
1773 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1774 skb->dev ? skb->dev->name : "?");
1781 We do not cache source address of outgoing interface,
1782 because it is used only by IP RR, TS and SRR options,
1783 so that it out of fast path.
1785 BTW remember: "addr" is allowed to be not aligned
1789 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1793 if (rt_is_output_route(rt))
1794 src = ip_hdr(skb)->saddr;
1796 struct fib_result res;
1802 memset(&fl4, 0, sizeof(fl4));
1803 fl4.daddr = iph->daddr;
1804 fl4.saddr = iph->saddr;
1805 fl4.flowi4_tos = RT_TOS(iph->tos);
1806 fl4.flowi4_oif = rt->dst.dev->ifindex;
1807 fl4.flowi4_iif = skb->dev->ifindex;
1808 fl4.flowi4_mark = skb->mark;
1811 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1812 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1814 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1818 memcpy(addr, &src, 4);
1821 #ifdef CONFIG_IP_ROUTE_CLASSID
1822 static void set_class_tag(struct rtable *rt, u32 tag)
1824 if (!(rt->dst.tclassid & 0xFFFF))
1825 rt->dst.tclassid |= tag & 0xFFFF;
1826 if (!(rt->dst.tclassid & 0xFFFF0000))
1827 rt->dst.tclassid |= tag & 0xFFFF0000;
1831 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1833 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1836 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1838 if (advmss > 65535 - 40)
1839 advmss = 65535 - 40;
1844 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1846 const struct rtable *rt = (const struct rtable *) dst;
1847 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
1849 if (mtu && rt_is_output_route(rt))
1852 mtu = dst->dev->mtu;
1854 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1856 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1860 if (mtu > IP_MAX_MTU)
1866 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1867 struct fib_info *fi)
1869 struct inet_peer_base *base;
1870 struct inet_peer *peer;
1873 /* If a peer entry exists for this destination, we must hook
1874 * it up in order to get at cached metrics.
1876 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1879 base = inetpeer_base_ptr(rt->_peer);
1882 peer = inet_getpeer_v4(base, rt->rt_dst, create);
1884 __rt_set_peer(rt, peer);
1885 rt->rt_peer_genid = rt_peer_genid();
1886 if (inet_metrics_new(peer))
1887 memcpy(peer->metrics, fi->fib_metrics,
1888 sizeof(u32) * RTAX_MAX);
1889 dst_init_metrics(&rt->dst, peer->metrics, false);
1891 check_peer_pmtu(&rt->dst, peer);
1893 if (peer->redirect_learned.a4 &&
1894 peer->redirect_learned.a4 != rt->rt_gateway) {
1895 rt->rt_gateway = peer->redirect_learned.a4;
1896 rt->rt_flags |= RTCF_REDIRECTED;
1899 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1901 atomic_inc(&fi->fib_clntref);
1903 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1907 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1908 const struct fib_result *res,
1909 struct fib_info *fi, u16 type, u32 itag)
1911 struct dst_entry *dst = &rt->dst;
1914 if (FIB_RES_GW(*res) &&
1915 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1916 rt->rt_gateway = FIB_RES_GW(*res);
1917 rt_init_metrics(rt, fl4, fi);
1918 #ifdef CONFIG_IP_ROUTE_CLASSID
1919 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1923 if (dst_mtu(dst) > IP_MAX_MTU)
1924 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1925 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1926 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1928 #ifdef CONFIG_IP_ROUTE_CLASSID
1929 #ifdef CONFIG_IP_MULTIPLE_TABLES
1930 set_class_tag(rt, fib_rules_tclass(res));
1932 set_class_tag(rt, itag);
1936 static struct rtable *rt_dst_alloc(struct net_device *dev,
1937 bool nopolicy, bool noxfrm)
1939 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
1941 (nopolicy ? DST_NOPOLICY : 0) |
1942 (noxfrm ? DST_NOXFRM : 0));
1945 /* called in rcu_read_lock() section */
1946 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1947 u8 tos, struct net_device *dev, int our)
1952 struct in_device *in_dev = __in_dev_get_rcu(dev);
1956 /* Primary sanity checks. */
1961 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1962 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1965 if (ipv4_is_zeronet(saddr)) {
1966 if (!ipv4_is_local_multicast(daddr))
1968 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1970 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
1975 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1976 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1980 #ifdef CONFIG_IP_ROUTE_CLASSID
1981 rth->dst.tclassid = itag;
1983 rth->dst.output = ip_rt_bug;
1985 rth->rt_key_dst = daddr;
1986 rth->rt_key_src = saddr;
1987 rth->rt_genid = rt_genid(dev_net(dev));
1988 rth->rt_flags = RTCF_MULTICAST;
1989 rth->rt_type = RTN_MULTICAST;
1990 rth->rt_key_tos = tos;
1991 rth->rt_dst = daddr;
1992 rth->rt_src = saddr;
1993 rth->rt_route_iif = dev->ifindex;
1994 rth->rt_iif = dev->ifindex;
1996 rth->rt_mark = skb->mark;
1997 rth->rt_gateway = daddr;
1998 rth->rt_spec_dst= spec_dst;
1999 rth->rt_peer_genid = 0;
2000 rt_init_peer(rth, dev_net(dev)->ipv4.peers);
2003 rth->dst.input= ip_local_deliver;
2004 rth->rt_flags |= RTCF_LOCAL;
2007 #ifdef CONFIG_IP_MROUTE
2008 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
2009 rth->dst.input = ip_mr_input;
2011 RT_CACHE_STAT_INC(in_slow_mc);
2013 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
2014 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
2015 return IS_ERR(rth) ? PTR_ERR(rth) : 0;
2026 static void ip_handle_martian_source(struct net_device *dev,
2027 struct in_device *in_dev,
2028 struct sk_buff *skb,
2032 RT_CACHE_STAT_INC(in_martian_src);
2033 #ifdef CONFIG_IP_ROUTE_VERBOSE
2034 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
2036 * RFC1812 recommendation, if source is martian,
2037 * the only hint is MAC header.
2039 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
2040 &daddr, &saddr, dev->name);
2041 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
2042 print_hex_dump(KERN_WARNING, "ll header: ",
2043 DUMP_PREFIX_OFFSET, 16, 1,
2044 skb_mac_header(skb),
2045 dev->hard_header_len, true);
2051 /* called in rcu_read_lock() section */
2052 static int __mkroute_input(struct sk_buff *skb,
2053 const struct fib_result *res,
2054 struct in_device *in_dev,
2055 __be32 daddr, __be32 saddr, u32 tos,
2056 struct rtable **result)
2060 struct in_device *out_dev;
2061 unsigned int flags = 0;
2065 /* get a working reference to the output device */
2066 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
2067 if (out_dev == NULL) {
2068 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
2073 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
2074 in_dev->dev, &spec_dst, &itag);
2076 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2083 flags |= RTCF_DIRECTSRC;
2085 if (out_dev == in_dev && err &&
2086 (IN_DEV_SHARED_MEDIA(out_dev) ||
2087 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2088 flags |= RTCF_DOREDIRECT;
2090 if (skb->protocol != htons(ETH_P_IP)) {
2091 /* Not IP (i.e. ARP). Do not create route, if it is
2092 * invalid for proxy arp. DNAT routes are always valid.
2094 * Proxy arp feature have been extended to allow, ARP
2095 * replies back to the same interface, to support
2096 * Private VLAN switch technologies. See arp.c.
2098 if (out_dev == in_dev &&
2099 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2105 rth = rt_dst_alloc(out_dev->dev,
2106 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2107 IN_DEV_CONF_GET(out_dev, NOXFRM));
2113 rth->rt_key_dst = daddr;
2114 rth->rt_key_src = saddr;
2115 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2116 rth->rt_flags = flags;
2117 rth->rt_type = res->type;
2118 rth->rt_key_tos = tos;
2119 rth->rt_dst = daddr;
2120 rth->rt_src = saddr;
2121 rth->rt_route_iif = in_dev->dev->ifindex;
2122 rth->rt_iif = in_dev->dev->ifindex;
2124 rth->rt_mark = skb->mark;
2125 rth->rt_gateway = daddr;
2126 rth->rt_spec_dst= spec_dst;
2127 rth->rt_peer_genid = 0;
2128 rt_init_peer(rth, dev_net(rth->dst.dev)->ipv4.peers);
2131 rth->dst.input = ip_forward;
2132 rth->dst.output = ip_output;
2134 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2142 static int ip_mkroute_input(struct sk_buff *skb,
2143 struct fib_result *res,
2144 const struct flowi4 *fl4,
2145 struct in_device *in_dev,
2146 __be32 daddr, __be32 saddr, u32 tos)
2148 struct rtable *rth = NULL;
2152 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2153 if (res->fi && res->fi->fib_nhs > 1)
2154 fib_select_multipath(res);
2157 /* create a routing cache entry */
2158 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2162 /* put it into the cache */
2163 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2164 rt_genid(dev_net(rth->dst.dev)));
2165 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2167 return PTR_ERR(rth);
2172 * NOTE. We drop all the packets that has local source
2173 * addresses, because every properly looped back packet
2174 * must have correct destination already attached by output routine.
2176 * Such approach solves two big problems:
2177 * 1. Not simplex devices are handled properly.
2178 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2179 * called with rcu_read_lock()
2182 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2183 u8 tos, struct net_device *dev)
2185 struct fib_result res;
2186 struct in_device *in_dev = __in_dev_get_rcu(dev);
2188 unsigned int flags = 0;
2194 struct net *net = dev_net(dev);
2196 /* IP on this device is disabled. */
2201 /* Check for the most weird martians, which can be not detected
2205 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2206 ipv4_is_loopback(saddr))
2207 goto martian_source;
2209 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2212 /* Accept zero addresses only to limited broadcast;
2213 * I even do not know to fix it or not. Waiting for complains :-)
2215 if (ipv4_is_zeronet(saddr))
2216 goto martian_source;
2218 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2219 goto martian_destination;
2222 * Now we are ready to route packet.
2225 fl4.flowi4_iif = dev->ifindex;
2226 fl4.flowi4_mark = skb->mark;
2227 fl4.flowi4_tos = tos;
2228 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2231 err = fib_lookup(net, &fl4, &res);
2233 if (!IN_DEV_FORWARD(in_dev))
2238 RT_CACHE_STAT_INC(in_slow_tot);
2240 if (res.type == RTN_BROADCAST)
2243 if (res.type == RTN_LOCAL) {
2244 err = fib_validate_source(skb, saddr, daddr, tos,
2245 net->loopback_dev->ifindex,
2246 dev, &spec_dst, &itag);
2248 goto martian_source_keep_err;
2250 flags |= RTCF_DIRECTSRC;
2255 if (!IN_DEV_FORWARD(in_dev))
2257 if (res.type != RTN_UNICAST)
2258 goto martian_destination;
2260 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2264 if (skb->protocol != htons(ETH_P_IP))
2267 if (ipv4_is_zeronet(saddr))
2268 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2270 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2273 goto martian_source_keep_err;
2275 flags |= RTCF_DIRECTSRC;
2277 flags |= RTCF_BROADCAST;
2278 res.type = RTN_BROADCAST;
2279 RT_CACHE_STAT_INC(in_brd);
2282 rth = rt_dst_alloc(net->loopback_dev,
2283 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2287 rth->dst.input= ip_local_deliver;
2288 rth->dst.output= ip_rt_bug;
2289 #ifdef CONFIG_IP_ROUTE_CLASSID
2290 rth->dst.tclassid = itag;
2293 rth->rt_key_dst = daddr;
2294 rth->rt_key_src = saddr;
2295 rth->rt_genid = rt_genid(net);
2296 rth->rt_flags = flags|RTCF_LOCAL;
2297 rth->rt_type = res.type;
2298 rth->rt_key_tos = tos;
2299 rth->rt_dst = daddr;
2300 rth->rt_src = saddr;
2301 #ifdef CONFIG_IP_ROUTE_CLASSID
2302 rth->dst.tclassid = itag;
2304 rth->rt_route_iif = dev->ifindex;
2305 rth->rt_iif = dev->ifindex;
2307 rth->rt_mark = skb->mark;
2308 rth->rt_gateway = daddr;
2309 rth->rt_spec_dst= spec_dst;
2310 rth->rt_peer_genid = 0;
2311 rt_init_peer(rth, net->ipv4.peers);
2313 if (res.type == RTN_UNREACHABLE) {
2314 rth->dst.input= ip_error;
2315 rth->dst.error= -err;
2316 rth->rt_flags &= ~RTCF_LOCAL;
2318 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2319 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2326 RT_CACHE_STAT_INC(in_no_route);
2327 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2328 res.type = RTN_UNREACHABLE;
2334 * Do not cache martian addresses: they should be logged (RFC1812)
2336 martian_destination:
2337 RT_CACHE_STAT_INC(in_martian_dst);
2338 #ifdef CONFIG_IP_ROUTE_VERBOSE
2339 if (IN_DEV_LOG_MARTIANS(in_dev))
2340 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2341 &daddr, &saddr, dev->name);
2345 err = -EHOSTUNREACH;
2358 martian_source_keep_err:
2359 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2363 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2364 u8 tos, struct net_device *dev, bool noref)
2368 int iif = dev->ifindex;
2376 if (!rt_caching(net))
2379 tos &= IPTOS_RT_MASK;
2380 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2382 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2383 rth = rcu_dereference(rth->dst.rt_next)) {
2384 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2385 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2386 (rth->rt_route_iif ^ iif) |
2387 (rth->rt_key_tos ^ tos)) == 0 &&
2388 rth->rt_mark == skb->mark &&
2389 net_eq(dev_net(rth->dst.dev), net) &&
2390 !rt_is_expired(rth)) {
2391 ipv4_validate_peer(rth);
2393 dst_use_noref(&rth->dst, jiffies);
2394 skb_dst_set_noref(skb, &rth->dst);
2396 dst_use(&rth->dst, jiffies);
2397 skb_dst_set(skb, &rth->dst);
2399 RT_CACHE_STAT_INC(in_hit);
2403 RT_CACHE_STAT_INC(in_hlist_search);
2407 /* Multicast recognition logic is moved from route cache to here.
2408 The problem was that too many Ethernet cards have broken/missing
2409 hardware multicast filters :-( As result the host on multicasting
2410 network acquires a lot of useless route cache entries, sort of
2411 SDR messages from all the world. Now we try to get rid of them.
2412 Really, provided software IP multicast filter is organized
2413 reasonably (at least, hashed), it does not result in a slowdown
2414 comparing with route cache reject entries.
2415 Note, that multicast routers are not affected, because
2416 route cache entry is created eventually.
2418 if (ipv4_is_multicast(daddr)) {
2419 struct in_device *in_dev = __in_dev_get_rcu(dev);
2422 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2423 ip_hdr(skb)->protocol);
2425 #ifdef CONFIG_IP_MROUTE
2427 (!ipv4_is_local_multicast(daddr) &&
2428 IN_DEV_MFORWARD(in_dev))
2431 int res = ip_route_input_mc(skb, daddr, saddr,
2440 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2444 EXPORT_SYMBOL(ip_route_input_common);
2446 /* called with rcu_read_lock() */
2447 static struct rtable *__mkroute_output(const struct fib_result *res,
2448 const struct flowi4 *fl4,
2449 __be32 orig_daddr, __be32 orig_saddr,
2450 int orig_oif, __u8 orig_rtos,
2451 struct net_device *dev_out,
2454 struct fib_info *fi = res->fi;
2455 struct in_device *in_dev;
2456 u16 type = res->type;
2459 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2460 return ERR_PTR(-EINVAL);
2462 if (ipv4_is_lbcast(fl4->daddr))
2463 type = RTN_BROADCAST;
2464 else if (ipv4_is_multicast(fl4->daddr))
2465 type = RTN_MULTICAST;
2466 else if (ipv4_is_zeronet(fl4->daddr))
2467 return ERR_PTR(-EINVAL);
2469 if (dev_out->flags & IFF_LOOPBACK)
2470 flags |= RTCF_LOCAL;
2472 in_dev = __in_dev_get_rcu(dev_out);
2474 return ERR_PTR(-EINVAL);
2476 if (type == RTN_BROADCAST) {
2477 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2479 } else if (type == RTN_MULTICAST) {
2480 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2481 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2483 flags &= ~RTCF_LOCAL;
2484 /* If multicast route do not exist use
2485 * default one, but do not gateway in this case.
2488 if (fi && res->prefixlen < 4)
2492 rth = rt_dst_alloc(dev_out,
2493 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2494 IN_DEV_CONF_GET(in_dev, NOXFRM));
2496 return ERR_PTR(-ENOBUFS);
2498 rth->dst.output = ip_output;
2500 rth->rt_key_dst = orig_daddr;
2501 rth->rt_key_src = orig_saddr;
2502 rth->rt_genid = rt_genid(dev_net(dev_out));
2503 rth->rt_flags = flags;
2504 rth->rt_type = type;
2505 rth->rt_key_tos = orig_rtos;
2506 rth->rt_dst = fl4->daddr;
2507 rth->rt_src = fl4->saddr;
2508 rth->rt_route_iif = 0;
2509 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2510 rth->rt_oif = orig_oif;
2511 rth->rt_mark = fl4->flowi4_mark;
2512 rth->rt_gateway = fl4->daddr;
2513 rth->rt_spec_dst= fl4->saddr;
2514 rth->rt_peer_genid = 0;
2515 rt_init_peer(rth, dev_net(dev_out)->ipv4.peers);
2518 RT_CACHE_STAT_INC(out_slow_tot);
2520 if (flags & RTCF_LOCAL) {
2521 rth->dst.input = ip_local_deliver;
2522 rth->rt_spec_dst = fl4->daddr;
2524 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2525 rth->rt_spec_dst = fl4->saddr;
2526 if (flags & RTCF_LOCAL &&
2527 !(dev_out->flags & IFF_LOOPBACK)) {
2528 rth->dst.output = ip_mc_output;
2529 RT_CACHE_STAT_INC(out_slow_mc);
2531 #ifdef CONFIG_IP_MROUTE
2532 if (type == RTN_MULTICAST) {
2533 if (IN_DEV_MFORWARD(in_dev) &&
2534 !ipv4_is_local_multicast(fl4->daddr)) {
2535 rth->dst.input = ip_mr_input;
2536 rth->dst.output = ip_mc_output;
2542 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2548 * Major route resolver routine.
2549 * called with rcu_read_lock();
2552 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2554 struct net_device *dev_out = NULL;
2555 __u8 tos = RT_FL_TOS(fl4);
2556 unsigned int flags = 0;
2557 struct fib_result res;
2564 #ifdef CONFIG_IP_MULTIPLE_TABLES
2568 orig_daddr = fl4->daddr;
2569 orig_saddr = fl4->saddr;
2570 orig_oif = fl4->flowi4_oif;
2572 fl4->flowi4_iif = net->loopback_dev->ifindex;
2573 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2574 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2575 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2579 rth = ERR_PTR(-EINVAL);
2580 if (ipv4_is_multicast(fl4->saddr) ||
2581 ipv4_is_lbcast(fl4->saddr) ||
2582 ipv4_is_zeronet(fl4->saddr))
2585 /* I removed check for oif == dev_out->oif here.
2586 It was wrong for two reasons:
2587 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2588 is assigned to multiple interfaces.
2589 2. Moreover, we are allowed to send packets with saddr
2590 of another iface. --ANK
2593 if (fl4->flowi4_oif == 0 &&
2594 (ipv4_is_multicast(fl4->daddr) ||
2595 ipv4_is_lbcast(fl4->daddr))) {
2596 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2597 dev_out = __ip_dev_find(net, fl4->saddr, false);
2598 if (dev_out == NULL)
2601 /* Special hack: user can direct multicasts
2602 and limited broadcast via necessary interface
2603 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2604 This hack is not just for fun, it allows
2605 vic,vat and friends to work.
2606 They bind socket to loopback, set ttl to zero
2607 and expect that it will work.
2608 From the viewpoint of routing cache they are broken,
2609 because we are not allowed to build multicast path
2610 with loopback source addr (look, routing cache
2611 cannot know, that ttl is zero, so that packet
2612 will not leave this host and route is valid).
2613 Luckily, this hack is good workaround.
2616 fl4->flowi4_oif = dev_out->ifindex;
2620 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2621 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2622 if (!__ip_dev_find(net, fl4->saddr, false))
2628 if (fl4->flowi4_oif) {
2629 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2630 rth = ERR_PTR(-ENODEV);
2631 if (dev_out == NULL)
2634 /* RACE: Check return value of inet_select_addr instead. */
2635 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2636 rth = ERR_PTR(-ENETUNREACH);
2639 if (ipv4_is_local_multicast(fl4->daddr) ||
2640 ipv4_is_lbcast(fl4->daddr)) {
2642 fl4->saddr = inet_select_addr(dev_out, 0,
2647 if (ipv4_is_multicast(fl4->daddr))
2648 fl4->saddr = inet_select_addr(dev_out, 0,
2650 else if (!fl4->daddr)
2651 fl4->saddr = inet_select_addr(dev_out, 0,
2657 fl4->daddr = fl4->saddr;
2659 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2660 dev_out = net->loopback_dev;
2661 fl4->flowi4_oif = net->loopback_dev->ifindex;
2662 res.type = RTN_LOCAL;
2663 flags |= RTCF_LOCAL;
2667 if (fib_lookup(net, fl4, &res)) {
2669 if (fl4->flowi4_oif) {
2670 /* Apparently, routing tables are wrong. Assume,
2671 that the destination is on link.
2674 Because we are allowed to send to iface
2675 even if it has NO routes and NO assigned
2676 addresses. When oif is specified, routing
2677 tables are looked up with only one purpose:
2678 to catch if destination is gatewayed, rather than
2679 direct. Moreover, if MSG_DONTROUTE is set,
2680 we send packet, ignoring both routing tables
2681 and ifaddr state. --ANK
2684 We could make it even if oif is unknown,
2685 likely IPv6, but we do not.
2688 if (fl4->saddr == 0)
2689 fl4->saddr = inet_select_addr(dev_out, 0,
2691 res.type = RTN_UNICAST;
2694 rth = ERR_PTR(-ENETUNREACH);
2698 if (res.type == RTN_LOCAL) {
2700 if (res.fi->fib_prefsrc)
2701 fl4->saddr = res.fi->fib_prefsrc;
2703 fl4->saddr = fl4->daddr;
2705 dev_out = net->loopback_dev;
2706 fl4->flowi4_oif = dev_out->ifindex;
2708 flags |= RTCF_LOCAL;
2712 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2713 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2714 fib_select_multipath(&res);
2717 if (!res.prefixlen &&
2718 res.table->tb_num_default > 1 &&
2719 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2720 fib_select_default(&res);
2723 fl4->saddr = FIB_RES_PREFSRC(net, res);
2725 dev_out = FIB_RES_DEV(res);
2726 fl4->flowi4_oif = dev_out->ifindex;
2730 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2731 tos, dev_out, flags);
2735 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2736 rt_genid(dev_net(dev_out)));
2737 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2745 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2750 if (!rt_caching(net))
2753 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2756 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2757 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2758 if (rth->rt_key_dst == flp4->daddr &&
2759 rth->rt_key_src == flp4->saddr &&
2760 rt_is_output_route(rth) &&
2761 rth->rt_oif == flp4->flowi4_oif &&
2762 rth->rt_mark == flp4->flowi4_mark &&
2763 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2764 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2765 net_eq(dev_net(rth->dst.dev), net) &&
2766 !rt_is_expired(rth)) {
2767 ipv4_validate_peer(rth);
2768 dst_use(&rth->dst, jiffies);
2769 RT_CACHE_STAT_INC(out_hit);
2770 rcu_read_unlock_bh();
2772 flp4->saddr = rth->rt_src;
2774 flp4->daddr = rth->rt_dst;
2777 RT_CACHE_STAT_INC(out_hlist_search);
2779 rcu_read_unlock_bh();
2782 return ip_route_output_slow(net, flp4);
2784 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2786 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2791 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2793 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2795 return mtu ? : dst->dev->mtu;
2798 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2802 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2808 static struct dst_ops ipv4_dst_blackhole_ops = {
2810 .protocol = cpu_to_be16(ETH_P_IP),
2811 .destroy = ipv4_dst_destroy,
2812 .check = ipv4_blackhole_dst_check,
2813 .mtu = ipv4_blackhole_mtu,
2814 .default_advmss = ipv4_default_advmss,
2815 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2816 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2817 .neigh_lookup = ipv4_neigh_lookup,
2820 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2822 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2823 struct rtable *ort = (struct rtable *) dst_orig;
2826 struct dst_entry *new = &rt->dst;
2829 new->input = dst_discard;
2830 new->output = dst_discard;
2831 dst_copy_metrics(new, &ort->dst);
2833 new->dev = ort->dst.dev;
2837 rt->rt_key_dst = ort->rt_key_dst;
2838 rt->rt_key_src = ort->rt_key_src;
2839 rt->rt_key_tos = ort->rt_key_tos;
2840 rt->rt_route_iif = ort->rt_route_iif;
2841 rt->rt_iif = ort->rt_iif;
2842 rt->rt_oif = ort->rt_oif;
2843 rt->rt_mark = ort->rt_mark;
2845 rt->rt_genid = rt_genid(net);
2846 rt->rt_flags = ort->rt_flags;
2847 rt->rt_type = ort->rt_type;
2848 rt->rt_dst = ort->rt_dst;
2849 rt->rt_src = ort->rt_src;
2850 rt->rt_gateway = ort->rt_gateway;
2851 rt->rt_spec_dst = ort->rt_spec_dst;
2852 rt_transfer_peer(rt, ort);
2855 atomic_inc(&rt->fi->fib_clntref);
2860 dst_release(dst_orig);
2862 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2865 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2868 struct rtable *rt = __ip_route_output_key(net, flp4);
2873 if (flp4->flowi4_proto)
2874 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2875 flowi4_to_flowi(flp4),
2880 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2882 static int rt_fill_info(struct net *net,
2883 struct sk_buff *skb, u32 pid, u32 seq, int event,
2884 int nowait, unsigned int flags)
2886 struct rtable *rt = skb_rtable(skb);
2888 struct nlmsghdr *nlh;
2889 unsigned long expires = 0;
2890 u32 id = 0, ts = 0, tsage = 0, error;
2892 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2896 r = nlmsg_data(nlh);
2897 r->rtm_family = AF_INET;
2898 r->rtm_dst_len = 32;
2900 r->rtm_tos = rt->rt_key_tos;
2901 r->rtm_table = RT_TABLE_MAIN;
2902 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2903 goto nla_put_failure;
2904 r->rtm_type = rt->rt_type;
2905 r->rtm_scope = RT_SCOPE_UNIVERSE;
2906 r->rtm_protocol = RTPROT_UNSPEC;
2907 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2908 if (rt->rt_flags & RTCF_NOTIFY)
2909 r->rtm_flags |= RTM_F_NOTIFY;
2911 if (nla_put_be32(skb, RTA_DST, rt->rt_dst))
2912 goto nla_put_failure;
2913 if (rt->rt_key_src) {
2914 r->rtm_src_len = 32;
2915 if (nla_put_be32(skb, RTA_SRC, rt->rt_key_src))
2916 goto nla_put_failure;
2919 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2920 goto nla_put_failure;
2921 #ifdef CONFIG_IP_ROUTE_CLASSID
2922 if (rt->dst.tclassid &&
2923 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2924 goto nla_put_failure;
2926 if (rt_is_input_route(rt)) {
2927 if (nla_put_be32(skb, RTA_PREFSRC, rt->rt_spec_dst))
2928 goto nla_put_failure;
2929 } else if (rt->rt_src != rt->rt_key_src) {
2930 if (nla_put_be32(skb, RTA_PREFSRC, rt->rt_src))
2931 goto nla_put_failure;
2933 if (rt->rt_dst != rt->rt_gateway &&
2934 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2935 goto nla_put_failure;
2937 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2938 goto nla_put_failure;
2941 nla_put_be32(skb, RTA_MARK, rt->rt_mark))
2942 goto nla_put_failure;
2944 error = rt->dst.error;
2945 if (rt_has_peer(rt)) {
2946 const struct inet_peer *peer = rt_peer_ptr(rt);
2947 inet_peer_refcheck(peer);
2948 id = atomic_read(&peer->ip_id_count) & 0xffff;
2949 if (peer->tcp_ts_stamp) {
2951 tsage = get_seconds() - peer->tcp_ts_stamp;
2953 expires = ACCESS_ONCE(peer->pmtu_expires);
2955 if (time_before(jiffies, expires))
2962 if (rt_is_input_route(rt)) {
2963 #ifdef CONFIG_IP_MROUTE
2964 __be32 dst = rt->rt_dst;
2966 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2967 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2968 int err = ipmr_get_route(net, skb,
2969 rt->rt_src, rt->rt_dst,
2975 goto nla_put_failure;
2977 if (err == -EMSGSIZE)
2978 goto nla_put_failure;
2984 if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
2985 goto nla_put_failure;
2988 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2989 expires, error) < 0)
2990 goto nla_put_failure;
2992 return nlmsg_end(skb, nlh);
2995 nlmsg_cancel(skb, nlh);
2999 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
3001 struct net *net = sock_net(in_skb->sk);
3003 struct nlattr *tb[RTA_MAX+1];
3004 struct rtable *rt = NULL;
3010 struct sk_buff *skb;
3012 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
3016 rtm = nlmsg_data(nlh);
3018 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3024 /* Reserve room for dummy headers, this skb can pass
3025 through good chunk of routing engine.
3027 skb_reset_mac_header(skb);
3028 skb_reset_network_header(skb);
3030 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
3031 ip_hdr(skb)->protocol = IPPROTO_ICMP;
3032 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
3034 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
3035 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
3036 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
3037 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
3040 struct net_device *dev;
3042 dev = __dev_get_by_index(net, iif);
3048 skb->protocol = htons(ETH_P_IP);
3052 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
3055 rt = skb_rtable(skb);
3056 if (err == 0 && rt->dst.error)
3057 err = -rt->dst.error;
3059 struct flowi4 fl4 = {
3062 .flowi4_tos = rtm->rtm_tos,
3063 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
3064 .flowi4_mark = mark,
3066 rt = ip_route_output_key(net, &fl4);
3076 skb_dst_set(skb, &rt->dst);
3077 if (rtm->rtm_flags & RTM_F_NOTIFY)
3078 rt->rt_flags |= RTCF_NOTIFY;
3080 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3081 RTM_NEWROUTE, 0, 0);
3085 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3094 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3101 net = sock_net(skb->sk);
3106 s_idx = idx = cb->args[1];
3107 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3108 if (!rt_hash_table[h].chain)
3111 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3112 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3113 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3115 if (rt_is_expired(rt))
3117 skb_dst_set_noref(skb, &rt->dst);
3118 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3119 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3120 1, NLM_F_MULTI) <= 0) {
3122 rcu_read_unlock_bh();
3127 rcu_read_unlock_bh();
3136 void ip_rt_multicast_event(struct in_device *in_dev)
3138 rt_cache_flush(dev_net(in_dev->dev), 0);
3141 #ifdef CONFIG_SYSCTL
3142 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3143 void __user *buffer,
3144 size_t *lenp, loff_t *ppos)
3151 memcpy(&ctl, __ctl, sizeof(ctl));
3152 ctl.data = &flush_delay;
3153 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3155 net = (struct net *)__ctl->extra1;
3156 rt_cache_flush(net, flush_delay);
3163 static ctl_table ipv4_route_table[] = {
3165 .procname = "gc_thresh",
3166 .data = &ipv4_dst_ops.gc_thresh,
3167 .maxlen = sizeof(int),
3169 .proc_handler = proc_dointvec,
3172 .procname = "max_size",
3173 .data = &ip_rt_max_size,
3174 .maxlen = sizeof(int),
3176 .proc_handler = proc_dointvec,
3179 /* Deprecated. Use gc_min_interval_ms */
3181 .procname = "gc_min_interval",
3182 .data = &ip_rt_gc_min_interval,
3183 .maxlen = sizeof(int),
3185 .proc_handler = proc_dointvec_jiffies,
3188 .procname = "gc_min_interval_ms",
3189 .data = &ip_rt_gc_min_interval,
3190 .maxlen = sizeof(int),
3192 .proc_handler = proc_dointvec_ms_jiffies,
3195 .procname = "gc_timeout",
3196 .data = &ip_rt_gc_timeout,
3197 .maxlen = sizeof(int),
3199 .proc_handler = proc_dointvec_jiffies,
3202 .procname = "gc_interval",
3203 .data = &ip_rt_gc_interval,
3204 .maxlen = sizeof(int),
3206 .proc_handler = proc_dointvec_jiffies,
3209 .procname = "redirect_load",
3210 .data = &ip_rt_redirect_load,
3211 .maxlen = sizeof(int),
3213 .proc_handler = proc_dointvec,
3216 .procname = "redirect_number",
3217 .data = &ip_rt_redirect_number,
3218 .maxlen = sizeof(int),
3220 .proc_handler = proc_dointvec,
3223 .procname = "redirect_silence",
3224 .data = &ip_rt_redirect_silence,
3225 .maxlen = sizeof(int),
3227 .proc_handler = proc_dointvec,
3230 .procname = "error_cost",
3231 .data = &ip_rt_error_cost,
3232 .maxlen = sizeof(int),
3234 .proc_handler = proc_dointvec,
3237 .procname = "error_burst",
3238 .data = &ip_rt_error_burst,
3239 .maxlen = sizeof(int),
3241 .proc_handler = proc_dointvec,
3244 .procname = "gc_elasticity",
3245 .data = &ip_rt_gc_elasticity,
3246 .maxlen = sizeof(int),
3248 .proc_handler = proc_dointvec,
3251 .procname = "mtu_expires",
3252 .data = &ip_rt_mtu_expires,
3253 .maxlen = sizeof(int),
3255 .proc_handler = proc_dointvec_jiffies,
3258 .procname = "min_pmtu",
3259 .data = &ip_rt_min_pmtu,
3260 .maxlen = sizeof(int),
3262 .proc_handler = proc_dointvec,
3265 .procname = "min_adv_mss",
3266 .data = &ip_rt_min_advmss,
3267 .maxlen = sizeof(int),
3269 .proc_handler = proc_dointvec,
3274 static struct ctl_table ipv4_route_flush_table[] = {
3276 .procname = "flush",
3277 .maxlen = sizeof(int),
3279 .proc_handler = ipv4_sysctl_rtcache_flush,
3284 static __net_init int sysctl_route_net_init(struct net *net)
3286 struct ctl_table *tbl;
3288 tbl = ipv4_route_flush_table;
3289 if (!net_eq(net, &init_net)) {
3290 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3294 tbl[0].extra1 = net;
3296 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
3297 if (net->ipv4.route_hdr == NULL)
3302 if (tbl != ipv4_route_flush_table)
3308 static __net_exit void sysctl_route_net_exit(struct net *net)
3310 struct ctl_table *tbl;
3312 tbl = net->ipv4.route_hdr->ctl_table_arg;
3313 unregister_net_sysctl_table(net->ipv4.route_hdr);
3314 BUG_ON(tbl == ipv4_route_flush_table);
3318 static __net_initdata struct pernet_operations sysctl_route_ops = {
3319 .init = sysctl_route_net_init,
3320 .exit = sysctl_route_net_exit,
3324 static __net_init int rt_genid_init(struct net *net)
3326 get_random_bytes(&net->ipv4.rt_genid,
3327 sizeof(net->ipv4.rt_genid));
3328 get_random_bytes(&net->ipv4.dev_addr_genid,
3329 sizeof(net->ipv4.dev_addr_genid));
3333 static __net_initdata struct pernet_operations rt_genid_ops = {
3334 .init = rt_genid_init,
3337 static int __net_init ipv4_inetpeer_init(struct net *net)
3339 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3343 inet_peer_base_init(bp);
3344 net->ipv4.peers = bp;
3348 static void __net_exit ipv4_inetpeer_exit(struct net *net)
3350 struct inet_peer_base *bp = net->ipv4.peers;
3352 net->ipv4.peers = NULL;
3353 inetpeer_invalidate_tree(bp);
3357 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
3358 .init = ipv4_inetpeer_init,
3359 .exit = ipv4_inetpeer_exit,
3362 #ifdef CONFIG_IP_ROUTE_CLASSID
3363 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3364 #endif /* CONFIG_IP_ROUTE_CLASSID */
3366 static __initdata unsigned long rhash_entries;
3367 static int __init set_rhash_entries(char *str)
3374 ret = kstrtoul(str, 0, &rhash_entries);
3380 __setup("rhash_entries=", set_rhash_entries);
3382 int __init ip_rt_init(void)
3386 #ifdef CONFIG_IP_ROUTE_CLASSID
3387 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3389 panic("IP: failed to allocate ip_rt_acct\n");
3392 ipv4_dst_ops.kmem_cachep =
3393 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3394 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3396 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3398 if (dst_entries_init(&ipv4_dst_ops) < 0)
3399 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3401 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3402 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3404 rt_hash_table = (struct rt_hash_bucket *)
3405 alloc_large_system_hash("IP route cache",
3406 sizeof(struct rt_hash_bucket),
3408 (totalram_pages >= 128 * 1024) ?
3414 rhash_entries ? 0 : 512 * 1024);
3415 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3416 rt_hash_lock_init();
3418 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3419 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3424 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func);
3425 expires_ljiffies = jiffies;
3426 schedule_delayed_work(&expires_work,
3427 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3429 if (ip_rt_proc_init())
3430 pr_err("Unable to create route proc files\n");
3433 xfrm4_init(ip_rt_max_size);
3435 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
3437 #ifdef CONFIG_SYSCTL
3438 register_pernet_subsys(&sysctl_route_ops);
3440 register_pernet_subsys(&rt_genid_ops);
3441 register_pernet_subsys(&ipv4_inetpeer_ops);
3445 #ifdef CONFIG_SYSCTL
3447 * We really need to sanitize the damn ipv4 init order, then all
3448 * this nonsense will go away.
3450 void __init ip_static_sysctl_init(void)
3452 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);