2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * ROUTE - implementation of the IP router.
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
65 #include <linux/module.h>
66 #include <asm/uaccess.h>
67 #include <asm/system.h>
68 #include <linux/bitops.h>
69 #include <linux/types.h>
70 #include <linux/kernel.h>
72 #include <linux/bootmem.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/workqueue.h>
83 #include <linux/skbuff.h>
84 #include <linux/inetdevice.h>
85 #include <linux/igmp.h>
86 #include <linux/pkt_sched.h>
87 #include <linux/mroute.h>
88 #include <linux/netfilter_ipv4.h>
89 #include <linux/random.h>
90 #include <linux/jhash.h>
91 #include <linux/rcupdate.h>
92 #include <linux/times.h>
93 #include <linux/slab.h>
95 #include <net/net_namespace.h>
96 #include <net/protocol.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/netevent.h>
107 #include <net/rtnetlink.h>
109 #include <linux/sysctl.h>
112 #define RT_FL_TOS(oldflp4) \
113 ((u32)(oldflp4->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
115 #define IP_MAX_MTU 0xFFF0
117 #define RT_GC_TIMEOUT (300*HZ)
119 static int ip_rt_max_size;
120 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
121 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
122 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
123 static int ip_rt_redirect_number __read_mostly = 9;
124 static int ip_rt_redirect_load __read_mostly = HZ / 50;
125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly = HZ;
127 static int ip_rt_error_burst __read_mostly = 5 * HZ;
128 static int ip_rt_gc_elasticity __read_mostly = 8;
129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
130 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly = 256;
132 static int rt_chain_length_max __read_mostly = 20;
135 * Interface to generic destination cache.
138 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
139 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
140 static unsigned int ipv4_default_mtu(const struct dst_entry *dst);
141 static void ipv4_dst_destroy(struct dst_entry *dst);
142 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
143 static void ipv4_link_failure(struct sk_buff *skb);
144 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
145 static int rt_garbage_collect(struct dst_ops *ops);
147 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
152 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
154 struct rtable *rt = (struct rtable *) dst;
155 struct inet_peer *peer;
163 u32 *old_p = __DST_METRICS_PTR(old);
164 unsigned long prev, new;
167 if (inet_metrics_new(peer))
168 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
170 new = (unsigned long) p;
171 prev = cmpxchg(&dst->_metrics, old, new);
174 p = __DST_METRICS_PTR(prev);
175 if (prev & DST_METRICS_READ_ONLY)
179 fib_info_put(rt->fi);
187 static struct dst_ops ipv4_dst_ops = {
189 .protocol = cpu_to_be16(ETH_P_IP),
190 .gc = rt_garbage_collect,
191 .check = ipv4_dst_check,
192 .default_advmss = ipv4_default_advmss,
193 .default_mtu = ipv4_default_mtu,
194 .cow_metrics = ipv4_cow_metrics,
195 .destroy = ipv4_dst_destroy,
196 .ifdown = ipv4_dst_ifdown,
197 .negative_advice = ipv4_negative_advice,
198 .link_failure = ipv4_link_failure,
199 .update_pmtu = ip_rt_update_pmtu,
200 .local_out = __ip_local_out,
203 #define ECN_OR_COST(class) TC_PRIO_##class
205 const __u8 ip_tos2prio[16] = {
207 ECN_OR_COST(BESTEFFORT),
209 ECN_OR_COST(BESTEFFORT),
215 ECN_OR_COST(INTERACTIVE),
217 ECN_OR_COST(INTERACTIVE),
218 TC_PRIO_INTERACTIVE_BULK,
219 ECN_OR_COST(INTERACTIVE_BULK),
220 TC_PRIO_INTERACTIVE_BULK,
221 ECN_OR_COST(INTERACTIVE_BULK)
229 /* The locking scheme is rather straight forward:
231 * 1) Read-Copy Update protects the buckets of the central route hash.
232 * 2) Only writers remove entries, and they hold the lock
233 * as they look at rtable reference counts.
234 * 3) Only readers acquire references to rtable entries,
235 * they do so with atomic increments and with the
239 struct rt_hash_bucket {
240 struct rtable __rcu *chain;
243 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
244 defined(CONFIG_PROVE_LOCKING)
246 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
247 * The size of this table is a power of two and depends on the number of CPUS.
248 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
250 #ifdef CONFIG_LOCKDEP
251 # define RT_HASH_LOCK_SZ 256
254 # define RT_HASH_LOCK_SZ 4096
256 # define RT_HASH_LOCK_SZ 2048
258 # define RT_HASH_LOCK_SZ 1024
260 # define RT_HASH_LOCK_SZ 512
262 # define RT_HASH_LOCK_SZ 256
266 static spinlock_t *rt_hash_locks;
267 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
269 static __init void rt_hash_lock_init(void)
273 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
276 panic("IP: failed to allocate rt_hash_locks\n");
278 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
279 spin_lock_init(&rt_hash_locks[i]);
282 # define rt_hash_lock_addr(slot) NULL
284 static inline void rt_hash_lock_init(void)
289 static struct rt_hash_bucket *rt_hash_table __read_mostly;
290 static unsigned rt_hash_mask __read_mostly;
291 static unsigned int rt_hash_log __read_mostly;
293 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
294 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
296 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
299 return jhash_3words((__force u32)daddr, (__force u32)saddr,
304 static inline int rt_genid(struct net *net)
306 return atomic_read(&net->ipv4.rt_genid);
309 #ifdef CONFIG_PROC_FS
310 struct rt_cache_iter_state {
311 struct seq_net_private p;
316 static struct rtable *rt_cache_get_first(struct seq_file *seq)
318 struct rt_cache_iter_state *st = seq->private;
319 struct rtable *r = NULL;
321 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
322 if (!rcu_dereference_raw(rt_hash_table[st->bucket].chain))
325 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
327 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
328 r->rt_genid == st->genid)
330 r = rcu_dereference_bh(r->dst.rt_next);
332 rcu_read_unlock_bh();
337 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
340 struct rt_cache_iter_state *st = seq->private;
342 r = rcu_dereference_bh(r->dst.rt_next);
344 rcu_read_unlock_bh();
346 if (--st->bucket < 0)
348 } while (!rcu_dereference_raw(rt_hash_table[st->bucket].chain));
350 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
355 static struct rtable *rt_cache_get_next(struct seq_file *seq,
358 struct rt_cache_iter_state *st = seq->private;
359 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
360 if (dev_net(r->dst.dev) != seq_file_net(seq))
362 if (r->rt_genid == st->genid)
368 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
370 struct rtable *r = rt_cache_get_first(seq);
373 while (pos && (r = rt_cache_get_next(seq, r)))
375 return pos ? NULL : r;
378 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
380 struct rt_cache_iter_state *st = seq->private;
382 return rt_cache_get_idx(seq, *pos - 1);
383 st->genid = rt_genid(seq_file_net(seq));
384 return SEQ_START_TOKEN;
387 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
391 if (v == SEQ_START_TOKEN)
392 r = rt_cache_get_first(seq);
394 r = rt_cache_get_next(seq, v);
399 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
401 if (v && v != SEQ_START_TOKEN)
402 rcu_read_unlock_bh();
405 static int rt_cache_seq_show(struct seq_file *seq, void *v)
407 if (v == SEQ_START_TOKEN)
408 seq_printf(seq, "%-127s\n",
409 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
410 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
413 struct rtable *r = v;
416 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
417 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
418 r->dst.dev ? r->dst.dev->name : "*",
419 (__force u32)r->rt_dst,
420 (__force u32)r->rt_gateway,
421 r->rt_flags, atomic_read(&r->dst.__refcnt),
422 r->dst.__use, 0, (__force u32)r->rt_src,
423 dst_metric_advmss(&r->dst) + 40,
424 dst_metric(&r->dst, RTAX_WINDOW),
425 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
426 dst_metric(&r->dst, RTAX_RTTVAR)),
428 r->dst.hh ? atomic_read(&r->dst.hh->hh_refcnt) : -1,
429 r->dst.hh ? (r->dst.hh->hh_output ==
431 r->rt_spec_dst, &len);
433 seq_printf(seq, "%*s\n", 127 - len, "");
438 static const struct seq_operations rt_cache_seq_ops = {
439 .start = rt_cache_seq_start,
440 .next = rt_cache_seq_next,
441 .stop = rt_cache_seq_stop,
442 .show = rt_cache_seq_show,
445 static int rt_cache_seq_open(struct inode *inode, struct file *file)
447 return seq_open_net(inode, file, &rt_cache_seq_ops,
448 sizeof(struct rt_cache_iter_state));
451 static const struct file_operations rt_cache_seq_fops = {
452 .owner = THIS_MODULE,
453 .open = rt_cache_seq_open,
456 .release = seq_release_net,
460 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
465 return SEQ_START_TOKEN;
467 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
468 if (!cpu_possible(cpu))
471 return &per_cpu(rt_cache_stat, cpu);
476 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
480 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
481 if (!cpu_possible(cpu))
484 return &per_cpu(rt_cache_stat, cpu);
490 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
495 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
497 struct rt_cache_stat *st = v;
499 if (v == SEQ_START_TOKEN) {
500 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");
504 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
505 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
506 dst_entries_get_slow(&ipv4_dst_ops),
529 static const struct seq_operations rt_cpu_seq_ops = {
530 .start = rt_cpu_seq_start,
531 .next = rt_cpu_seq_next,
532 .stop = rt_cpu_seq_stop,
533 .show = rt_cpu_seq_show,
537 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
539 return seq_open(file, &rt_cpu_seq_ops);
542 static const struct file_operations rt_cpu_seq_fops = {
543 .owner = THIS_MODULE,
544 .open = rt_cpu_seq_open,
547 .release = seq_release,
550 #ifdef CONFIG_IP_ROUTE_CLASSID
551 static int rt_acct_proc_show(struct seq_file *m, void *v)
553 struct ip_rt_acct *dst, *src;
556 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
560 for_each_possible_cpu(i) {
561 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
562 for (j = 0; j < 256; j++) {
563 dst[j].o_bytes += src[j].o_bytes;
564 dst[j].o_packets += src[j].o_packets;
565 dst[j].i_bytes += src[j].i_bytes;
566 dst[j].i_packets += src[j].i_packets;
570 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
575 static int rt_acct_proc_open(struct inode *inode, struct file *file)
577 return single_open(file, rt_acct_proc_show, NULL);
580 static const struct file_operations rt_acct_proc_fops = {
581 .owner = THIS_MODULE,
582 .open = rt_acct_proc_open,
585 .release = single_release,
589 static int __net_init ip_rt_do_proc_init(struct net *net)
591 struct proc_dir_entry *pde;
593 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
598 pde = proc_create("rt_cache", S_IRUGO,
599 net->proc_net_stat, &rt_cpu_seq_fops);
603 #ifdef CONFIG_IP_ROUTE_CLASSID
604 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
610 #ifdef CONFIG_IP_ROUTE_CLASSID
612 remove_proc_entry("rt_cache", net->proc_net_stat);
615 remove_proc_entry("rt_cache", net->proc_net);
620 static void __net_exit ip_rt_do_proc_exit(struct net *net)
622 remove_proc_entry("rt_cache", net->proc_net_stat);
623 remove_proc_entry("rt_cache", net->proc_net);
624 #ifdef CONFIG_IP_ROUTE_CLASSID
625 remove_proc_entry("rt_acct", net->proc_net);
629 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
630 .init = ip_rt_do_proc_init,
631 .exit = ip_rt_do_proc_exit,
634 static int __init ip_rt_proc_init(void)
636 return register_pernet_subsys(&ip_rt_proc_ops);
640 static inline int ip_rt_proc_init(void)
644 #endif /* CONFIG_PROC_FS */
646 static inline void rt_free(struct rtable *rt)
648 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
651 static inline void rt_drop(struct rtable *rt)
654 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
657 static inline int rt_fast_clean(struct rtable *rth)
659 /* Kill broadcast/multicast entries very aggresively, if they
660 collide in hash table with more useful entries */
661 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
662 rt_is_input_route(rth) && rth->dst.rt_next;
665 static inline int rt_valuable(struct rtable *rth)
667 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
668 (rth->peer && rth->peer->pmtu_expires);
671 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
676 if (atomic_read(&rth->dst.__refcnt))
679 age = jiffies - rth->dst.lastuse;
680 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
681 (age <= tmo2 && rt_valuable(rth)))
687 /* Bits of score are:
689 * 30: not quite useless
690 * 29..0: usage counter
692 static inline u32 rt_score(struct rtable *rt)
694 u32 score = jiffies - rt->dst.lastuse;
696 score = ~score & ~(3<<30);
701 if (rt_is_output_route(rt) ||
702 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
708 static inline bool rt_caching(const struct net *net)
710 return net->ipv4.current_rt_cache_rebuild_count <=
711 net->ipv4.sysctl_rt_cache_rebuild_count;
714 static inline bool compare_hash_inputs(const struct rtable *rt1,
715 const struct rtable *rt2)
717 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
718 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
719 (rt1->rt_iif ^ rt2->rt_iif)) == 0);
722 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
724 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
725 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
726 (rt1->rt_mark ^ rt2->rt_mark) |
727 (rt1->rt_key_tos ^ rt2->rt_key_tos) |
728 (rt1->rt_oif ^ rt2->rt_oif) |
729 (rt1->rt_iif ^ rt2->rt_iif)) == 0;
732 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
734 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
737 static inline int rt_is_expired(struct rtable *rth)
739 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
743 * Perform a full scan of hash table and free all entries.
744 * Can be called by a softirq or a process.
745 * In the later case, we want to be reschedule if necessary
747 static void rt_do_flush(struct net *net, int process_context)
750 struct rtable *rth, *next;
752 for (i = 0; i <= rt_hash_mask; i++) {
753 struct rtable __rcu **pprev;
756 if (process_context && need_resched())
758 rth = rcu_dereference_raw(rt_hash_table[i].chain);
762 spin_lock_bh(rt_hash_lock_addr(i));
765 pprev = &rt_hash_table[i].chain;
766 rth = rcu_dereference_protected(*pprev,
767 lockdep_is_held(rt_hash_lock_addr(i)));
770 next = rcu_dereference_protected(rth->dst.rt_next,
771 lockdep_is_held(rt_hash_lock_addr(i)));
774 net_eq(dev_net(rth->dst.dev), net)) {
775 rcu_assign_pointer(*pprev, next);
776 rcu_assign_pointer(rth->dst.rt_next, list);
779 pprev = &rth->dst.rt_next;
784 spin_unlock_bh(rt_hash_lock_addr(i));
786 for (; list; list = next) {
787 next = rcu_dereference_protected(list->dst.rt_next, 1);
794 * While freeing expired entries, we compute average chain length
795 * and standard deviation, using fixed-point arithmetic.
796 * This to have an estimation of rt_chain_length_max
797 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
798 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
802 #define ONE (1UL << FRACT_BITS)
805 * Given a hash chain and an item in this hash chain,
806 * find if a previous entry has the same hash_inputs
807 * (but differs on tos, mark or oif)
808 * Returns 0 if an alias is found.
809 * Returns ONE if rth has no alias before itself.
811 static int has_noalias(const struct rtable *head, const struct rtable *rth)
813 const struct rtable *aux = head;
816 if (compare_hash_inputs(aux, rth))
818 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
824 * Perturbation of rt_genid by a small quantity [1..256]
825 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
826 * many times (2^24) without giving recent rt_genid.
827 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
829 static void rt_cache_invalidate(struct net *net)
831 unsigned char shuffle;
833 get_random_bytes(&shuffle, sizeof(shuffle));
834 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
838 * delay < 0 : invalidate cache (fast : entries will be deleted later)
839 * delay >= 0 : invalidate & flush cache (can be long)
841 void rt_cache_flush(struct net *net, int delay)
843 rt_cache_invalidate(net);
845 rt_do_flush(net, !in_softirq());
848 /* Flush previous cache invalidated entries from the cache */
849 void rt_cache_flush_batch(struct net *net)
851 rt_do_flush(net, !in_softirq());
854 static void rt_emergency_hash_rebuild(struct net *net)
857 printk(KERN_WARNING "Route hash chain too long!\n");
858 rt_cache_invalidate(net);
862 Short description of GC goals.
864 We want to build algorithm, which will keep routing cache
865 at some equilibrium point, when number of aged off entries
866 is kept approximately equal to newly generated ones.
868 Current expiration strength is variable "expire".
869 We try to adjust it dynamically, so that if networking
870 is idle expires is large enough to keep enough of warm entries,
871 and when load increases it reduces to limit cache size.
874 static int rt_garbage_collect(struct dst_ops *ops)
876 static unsigned long expire = RT_GC_TIMEOUT;
877 static unsigned long last_gc;
879 static int equilibrium;
881 struct rtable __rcu **rthp;
882 unsigned long now = jiffies;
884 int entries = dst_entries_get_fast(&ipv4_dst_ops);
887 * Garbage collection is pretty expensive,
888 * do not make it too frequently.
891 RT_CACHE_STAT_INC(gc_total);
893 if (now - last_gc < ip_rt_gc_min_interval &&
894 entries < ip_rt_max_size) {
895 RT_CACHE_STAT_INC(gc_ignored);
899 entries = dst_entries_get_slow(&ipv4_dst_ops);
900 /* Calculate number of entries, which we want to expire now. */
901 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
903 if (equilibrium < ipv4_dst_ops.gc_thresh)
904 equilibrium = ipv4_dst_ops.gc_thresh;
905 goal = entries - equilibrium;
907 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
908 goal = entries - equilibrium;
911 /* We are in dangerous area. Try to reduce cache really
914 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
915 equilibrium = entries - goal;
918 if (now - last_gc >= ip_rt_gc_min_interval)
929 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
930 unsigned long tmo = expire;
932 k = (k + 1) & rt_hash_mask;
933 rthp = &rt_hash_table[k].chain;
934 spin_lock_bh(rt_hash_lock_addr(k));
935 while ((rth = rcu_dereference_protected(*rthp,
936 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
937 if (!rt_is_expired(rth) &&
938 !rt_may_expire(rth, tmo, expire)) {
940 rthp = &rth->dst.rt_next;
943 *rthp = rth->dst.rt_next;
947 spin_unlock_bh(rt_hash_lock_addr(k));
956 /* Goal is not achieved. We stop process if:
958 - if expire reduced to zero. Otherwise, expire is halfed.
959 - if table is not full.
960 - if we are called from interrupt.
961 - jiffies check is just fallback/debug loop breaker.
962 We will not spin here for long time in any case.
965 RT_CACHE_STAT_INC(gc_goal_miss);
971 #if RT_CACHE_DEBUG >= 2
972 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
973 dst_entries_get_fast(&ipv4_dst_ops), goal, i);
976 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
978 } while (!in_softirq() && time_before_eq(jiffies, now));
980 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
982 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
985 printk(KERN_WARNING "dst cache overflow\n");
986 RT_CACHE_STAT_INC(gc_dst_overflow);
990 expire += ip_rt_gc_min_interval;
991 if (expire > ip_rt_gc_timeout ||
992 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
993 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
994 expire = ip_rt_gc_timeout;
995 #if RT_CACHE_DEBUG >= 2
996 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
997 dst_entries_get_fast(&ipv4_dst_ops), goal, rover);
1003 * Returns number of entries in a hash chain that have different hash_inputs
1005 static int slow_chain_length(const struct rtable *head)
1008 const struct rtable *rth = head;
1011 length += has_noalias(head, rth);
1012 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1014 return length >> FRACT_BITS;
1017 static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,
1018 struct sk_buff *skb, int ifindex)
1020 struct rtable *rth, *cand;
1021 struct rtable __rcu **rthp, **candp;
1025 int attempts = !in_softirq();
1029 min_score = ~(u32)0;
1034 if (!rt_caching(dev_net(rt->dst.dev))) {
1036 * If we're not caching, just tell the caller we
1037 * were successful and don't touch the route. The
1038 * caller hold the sole reference to the cache entry, and
1039 * it will be released when the caller is done with it.
1040 * If we drop it here, the callers have no way to resolve routes
1041 * when we're not caching. Instead, just point *rp at rt, so
1042 * the caller gets a single use out of the route
1043 * Note that we do rt_free on this new route entry, so that
1044 * once its refcount hits zero, we are still able to reap it
1046 * Note: To avoid expensive rcu stuff for this uncached dst,
1047 * we set DST_NOCACHE so that dst_release() can free dst without
1048 * waiting a grace period.
1051 rt->dst.flags |= DST_NOCACHE;
1052 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1053 int err = arp_bind_neighbour(&rt->dst);
1055 if (net_ratelimit())
1057 "Neighbour table failure & not caching routes.\n");
1059 return ERR_PTR(err);
1066 rthp = &rt_hash_table[hash].chain;
1068 spin_lock_bh(rt_hash_lock_addr(hash));
1069 while ((rth = rcu_dereference_protected(*rthp,
1070 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1071 if (rt_is_expired(rth)) {
1072 *rthp = rth->dst.rt_next;
1076 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1078 *rthp = rth->dst.rt_next;
1080 * Since lookup is lockfree, the deletion
1081 * must be visible to another weakly ordered CPU before
1082 * the insertion at the start of the hash chain.
1084 rcu_assign_pointer(rth->dst.rt_next,
1085 rt_hash_table[hash].chain);
1087 * Since lookup is lockfree, the update writes
1088 * must be ordered for consistency on SMP.
1090 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1092 dst_use(&rth->dst, now);
1093 spin_unlock_bh(rt_hash_lock_addr(hash));
1097 skb_dst_set(skb, &rth->dst);
1101 if (!atomic_read(&rth->dst.__refcnt)) {
1102 u32 score = rt_score(rth);
1104 if (score <= min_score) {
1113 rthp = &rth->dst.rt_next;
1117 /* ip_rt_gc_elasticity used to be average length of chain
1118 * length, when exceeded gc becomes really aggressive.
1120 * The second limit is less certain. At the moment it allows
1121 * only 2 entries per bucket. We will see.
1123 if (chain_length > ip_rt_gc_elasticity) {
1124 *candp = cand->dst.rt_next;
1128 if (chain_length > rt_chain_length_max &&
1129 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1130 struct net *net = dev_net(rt->dst.dev);
1131 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1132 if (!rt_caching(net)) {
1133 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1134 rt->dst.dev->name, num);
1136 rt_emergency_hash_rebuild(net);
1137 spin_unlock_bh(rt_hash_lock_addr(hash));
1139 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1140 ifindex, rt_genid(net));
1145 /* Try to bind route to arp only if it is output
1146 route or unicast forwarding path.
1148 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1149 int err = arp_bind_neighbour(&rt->dst);
1151 spin_unlock_bh(rt_hash_lock_addr(hash));
1153 if (err != -ENOBUFS) {
1155 return ERR_PTR(err);
1158 /* Neighbour tables are full and nothing
1159 can be released. Try to shrink route cache,
1160 it is most likely it holds some neighbour records.
1162 if (attempts-- > 0) {
1163 int saved_elasticity = ip_rt_gc_elasticity;
1164 int saved_int = ip_rt_gc_min_interval;
1165 ip_rt_gc_elasticity = 1;
1166 ip_rt_gc_min_interval = 0;
1167 rt_garbage_collect(&ipv4_dst_ops);
1168 ip_rt_gc_min_interval = saved_int;
1169 ip_rt_gc_elasticity = saved_elasticity;
1173 if (net_ratelimit())
1174 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1176 return ERR_PTR(-ENOBUFS);
1180 rt->dst.rt_next = rt_hash_table[hash].chain;
1182 #if RT_CACHE_DEBUG >= 2
1183 if (rt->dst.rt_next) {
1185 printk(KERN_DEBUG "rt_cache @%02x: %pI4",
1187 for (trt = rt->dst.rt_next; trt; trt = trt->dst.rt_next)
1188 printk(" . %pI4", &trt->rt_dst);
1193 * Since lookup is lockfree, we must make sure
1194 * previous writes to rt are committed to memory
1195 * before making rt visible to other CPUS.
1197 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1199 spin_unlock_bh(rt_hash_lock_addr(hash));
1203 skb_dst_set(skb, &rt->dst);
1207 static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1209 static u32 rt_peer_genid(void)
1211 return atomic_read(&__rt_peer_genid);
1214 void rt_bind_peer(struct rtable *rt, int create)
1216 struct inet_peer *peer;
1218 peer = inet_getpeer_v4(rt->rt_dst, create);
1220 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1223 rt->rt_peer_genid = rt_peer_genid();
1227 * Peer allocation may fail only in serious out-of-memory conditions. However
1228 * we still can generate some output.
1229 * Random ID selection looks a bit dangerous because we have no chances to
1230 * select ID being unique in a reasonable period of time.
1231 * But broken packet identifier may be better than no packet at all.
1233 static void ip_select_fb_ident(struct iphdr *iph)
1235 static DEFINE_SPINLOCK(ip_fb_id_lock);
1236 static u32 ip_fallback_id;
1239 spin_lock_bh(&ip_fb_id_lock);
1240 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1241 iph->id = htons(salt & 0xFFFF);
1242 ip_fallback_id = salt;
1243 spin_unlock_bh(&ip_fb_id_lock);
1246 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1248 struct rtable *rt = (struct rtable *) dst;
1251 if (rt->peer == NULL)
1252 rt_bind_peer(rt, 1);
1254 /* If peer is attached to destination, it is never detached,
1255 so that we need not to grab a lock to dereference it.
1258 iph->id = htons(inet_getid(rt->peer, more));
1262 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1263 __builtin_return_address(0));
1265 ip_select_fb_ident(iph);
1267 EXPORT_SYMBOL(__ip_select_ident);
1269 static void rt_del(unsigned hash, struct rtable *rt)
1271 struct rtable __rcu **rthp;
1274 rthp = &rt_hash_table[hash].chain;
1275 spin_lock_bh(rt_hash_lock_addr(hash));
1277 while ((aux = rcu_dereference_protected(*rthp,
1278 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1279 if (aux == rt || rt_is_expired(aux)) {
1280 *rthp = aux->dst.rt_next;
1284 rthp = &aux->dst.rt_next;
1286 spin_unlock_bh(rt_hash_lock_addr(hash));
1289 /* called in rcu_read_lock() section */
1290 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1291 __be32 saddr, struct net_device *dev)
1293 struct in_device *in_dev = __in_dev_get_rcu(dev);
1294 struct inet_peer *peer;
1301 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1302 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1303 ipv4_is_zeronet(new_gw))
1304 goto reject_redirect;
1306 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1307 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1308 goto reject_redirect;
1309 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1310 goto reject_redirect;
1312 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1313 goto reject_redirect;
1316 peer = inet_getpeer_v4(daddr, 1);
1318 peer->redirect_learned.a4 = new_gw;
1322 atomic_inc(&__rt_peer_genid);
1327 #ifdef CONFIG_IP_ROUTE_VERBOSE
1328 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1329 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1330 " Advised path = %pI4 -> %pI4\n",
1331 &old_gw, dev->name, &new_gw,
1337 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1339 struct rtable *rt = (struct rtable *)dst;
1340 struct dst_entry *ret = dst;
1343 if (dst->obsolete > 0) {
1346 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1347 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1349 rt_genid(dev_net(dst->dev)));
1350 #if RT_CACHE_DEBUG >= 1
1351 printk(KERN_DEBUG "ipv4_negative_advice: redirect to %pI4/%02x dropped\n",
1352 &rt->rt_dst, rt->rt_key_tos);
1356 } else if (rt->peer &&
1357 rt->peer->pmtu_expires &&
1358 time_after_eq(jiffies, rt->peer->pmtu_expires)) {
1359 unsigned long orig = rt->peer->pmtu_expires;
1361 if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig)
1362 dst_metric_set(dst, RTAX_MTU,
1363 rt->peer->pmtu_orig);
1371 * 1. The first ip_rt_redirect_number redirects are sent
1372 * with exponential backoff, then we stop sending them at all,
1373 * assuming that the host ignores our redirects.
1374 * 2. If we did not see packets requiring redirects
1375 * during ip_rt_redirect_silence, we assume that the host
1376 * forgot redirected route and start to send redirects again.
1378 * This algorithm is much cheaper and more intelligent than dumb load limiting
1381 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1382 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1385 void ip_rt_send_redirect(struct sk_buff *skb)
1387 struct rtable *rt = skb_rtable(skb);
1388 struct in_device *in_dev;
1389 struct inet_peer *peer;
1393 in_dev = __in_dev_get_rcu(rt->dst.dev);
1394 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1398 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1402 rt_bind_peer(rt, 1);
1405 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1409 /* No redirected packets during ip_rt_redirect_silence;
1410 * reset the algorithm.
1412 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1413 peer->rate_tokens = 0;
1415 /* Too many ignored redirects; do not send anything
1416 * set dst.rate_last to the last seen redirected packet.
1418 if (peer->rate_tokens >= ip_rt_redirect_number) {
1419 peer->rate_last = jiffies;
1423 /* Check for load limit; set rate_last to the latest sent
1426 if (peer->rate_tokens == 0 ||
1429 (ip_rt_redirect_load << peer->rate_tokens)))) {
1430 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1431 peer->rate_last = jiffies;
1432 ++peer->rate_tokens;
1433 #ifdef CONFIG_IP_ROUTE_VERBOSE
1435 peer->rate_tokens == ip_rt_redirect_number &&
1437 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1438 &rt->rt_src, rt->rt_iif,
1439 &rt->rt_dst, &rt->rt_gateway);
1444 static int ip_error(struct sk_buff *skb)
1446 struct rtable *rt = skb_rtable(skb);
1447 struct inet_peer *peer;
1452 switch (rt->dst.error) {
1457 code = ICMP_HOST_UNREACH;
1460 code = ICMP_NET_UNREACH;
1461 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1462 IPSTATS_MIB_INNOROUTES);
1465 code = ICMP_PKT_FILTERED;
1470 rt_bind_peer(rt, 1);
1476 peer->rate_tokens += now - peer->rate_last;
1477 if (peer->rate_tokens > ip_rt_error_burst)
1478 peer->rate_tokens = ip_rt_error_burst;
1479 peer->rate_last = now;
1480 if (peer->rate_tokens >= ip_rt_error_cost)
1481 peer->rate_tokens -= ip_rt_error_cost;
1486 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1488 out: kfree_skb(skb);
1493 * The last two values are not from the RFC but
1494 * are needed for AMPRnet AX.25 paths.
1497 static const unsigned short mtu_plateau[] =
1498 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1500 static inline unsigned short guess_mtu(unsigned short old_mtu)
1504 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1505 if (old_mtu > mtu_plateau[i])
1506 return mtu_plateau[i];
1510 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
1511 unsigned short new_mtu,
1512 struct net_device *dev)
1514 unsigned short old_mtu = ntohs(iph->tot_len);
1515 unsigned short est_mtu = 0;
1516 struct inet_peer *peer;
1518 peer = inet_getpeer_v4(iph->daddr, 1);
1520 unsigned short mtu = new_mtu;
1522 if (new_mtu < 68 || new_mtu >= old_mtu) {
1523 /* BSD 4.2 derived systems incorrectly adjust
1524 * tot_len by the IP header length, and report
1525 * a zero MTU in the ICMP message.
1528 old_mtu >= 68 + (iph->ihl << 2))
1529 old_mtu -= iph->ihl << 2;
1530 mtu = guess_mtu(old_mtu);
1533 if (mtu < ip_rt_min_pmtu)
1534 mtu = ip_rt_min_pmtu;
1535 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1536 unsigned long pmtu_expires;
1538 pmtu_expires = jiffies + ip_rt_mtu_expires;
1543 peer->pmtu_learned = mtu;
1544 peer->pmtu_expires = pmtu_expires;
1549 atomic_inc(&__rt_peer_genid);
1551 return est_mtu ? : new_mtu;
1554 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1556 unsigned long expires = peer->pmtu_expires;
1558 if (time_before(jiffies, expires)) {
1559 u32 orig_dst_mtu = dst_mtu(dst);
1560 if (peer->pmtu_learned < orig_dst_mtu) {
1561 if (!peer->pmtu_orig)
1562 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1563 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1565 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1566 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1569 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1571 struct rtable *rt = (struct rtable *) dst;
1572 struct inet_peer *peer;
1577 rt_bind_peer(rt, 1);
1580 if (mtu < ip_rt_min_pmtu)
1581 mtu = ip_rt_min_pmtu;
1582 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1583 unsigned long pmtu_expires;
1585 pmtu_expires = jiffies + ip_rt_mtu_expires;
1589 peer->pmtu_learned = mtu;
1590 peer->pmtu_expires = pmtu_expires;
1592 atomic_inc(&__rt_peer_genid);
1593 rt->rt_peer_genid = rt_peer_genid();
1595 check_peer_pmtu(dst, peer);
1599 static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1601 struct rtable *rt = (struct rtable *) dst;
1602 __be32 orig_gw = rt->rt_gateway;
1604 dst_confirm(&rt->dst);
1606 neigh_release(rt->dst.neighbour);
1607 rt->dst.neighbour = NULL;
1609 rt->rt_gateway = peer->redirect_learned.a4;
1610 if (arp_bind_neighbour(&rt->dst) ||
1611 !(rt->dst.neighbour->nud_state & NUD_VALID)) {
1612 if (rt->dst.neighbour)
1613 neigh_event_send(rt->dst.neighbour, NULL);
1614 rt->rt_gateway = orig_gw;
1617 rt->rt_flags |= RTCF_REDIRECTED;
1618 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE,
1624 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1626 struct rtable *rt = (struct rtable *) dst;
1628 if (rt_is_expired(rt))
1630 if (rt->rt_peer_genid != rt_peer_genid()) {
1631 struct inet_peer *peer;
1634 rt_bind_peer(rt, 0);
1637 if (peer && peer->pmtu_expires)
1638 check_peer_pmtu(dst, peer);
1640 if (peer && peer->redirect_learned.a4 &&
1641 peer->redirect_learned.a4 != rt->rt_gateway) {
1642 if (check_peer_redir(dst, peer))
1646 rt->rt_peer_genid = rt_peer_genid();
1651 static void ipv4_dst_destroy(struct dst_entry *dst)
1653 struct rtable *rt = (struct rtable *) dst;
1654 struct inet_peer *peer = rt->peer;
1657 fib_info_put(rt->fi);
1667 static void ipv4_link_failure(struct sk_buff *skb)
1671 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1673 rt = skb_rtable(skb);
1676 rt->peer->pmtu_expires) {
1677 unsigned long orig = rt->peer->pmtu_expires;
1679 if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig)
1680 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1684 static int ip_rt_bug(struct sk_buff *skb)
1686 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1687 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1688 skb->dev ? skb->dev->name : "?");
1694 We do not cache source address of outgoing interface,
1695 because it is used only by IP RR, TS and SRR options,
1696 so that it out of fast path.
1698 BTW remember: "addr" is allowed to be not aligned
1702 void ip_rt_get_source(u8 *addr, struct rtable *rt)
1705 struct fib_result res;
1707 if (rt_is_output_route(rt))
1710 struct flowi4 fl4 = {
1711 .daddr = rt->rt_key_dst,
1712 .saddr = rt->rt_key_src,
1713 .flowi4_tos = rt->rt_key_tos,
1714 .flowi4_oif = rt->rt_oif,
1715 .flowi4_iif = rt->rt_iif,
1716 .flowi4_mark = rt->rt_mark,
1720 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1721 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1723 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1727 memcpy(addr, &src, 4);
1730 #ifdef CONFIG_IP_ROUTE_CLASSID
1731 static void set_class_tag(struct rtable *rt, u32 tag)
1733 if (!(rt->dst.tclassid & 0xFFFF))
1734 rt->dst.tclassid |= tag & 0xFFFF;
1735 if (!(rt->dst.tclassid & 0xFFFF0000))
1736 rt->dst.tclassid |= tag & 0xFFFF0000;
1740 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1742 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1745 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1747 if (advmss > 65535 - 40)
1748 advmss = 65535 - 40;
1753 static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
1755 unsigned int mtu = dst->dev->mtu;
1757 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1758 const struct rtable *rt = (const struct rtable *) dst;
1760 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1764 if (mtu > IP_MAX_MTU)
1770 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1771 struct fib_info *fi)
1773 struct inet_peer *peer;
1776 /* If a peer entry exists for this destination, we must hook
1777 * it up in order to get at cached metrics.
1779 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1782 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1784 rt->rt_peer_genid = rt_peer_genid();
1785 if (inet_metrics_new(peer))
1786 memcpy(peer->metrics, fi->fib_metrics,
1787 sizeof(u32) * RTAX_MAX);
1788 dst_init_metrics(&rt->dst, peer->metrics, false);
1790 if (peer->pmtu_expires)
1791 check_peer_pmtu(&rt->dst, peer);
1792 if (peer->redirect_learned.a4 &&
1793 peer->redirect_learned.a4 != rt->rt_gateway) {
1794 rt->rt_gateway = peer->redirect_learned.a4;
1795 rt->rt_flags |= RTCF_REDIRECTED;
1798 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1800 atomic_inc(&fi->fib_clntref);
1802 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1806 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1807 const struct fib_result *res,
1808 struct fib_info *fi, u16 type, u32 itag)
1810 struct dst_entry *dst = &rt->dst;
1813 if (FIB_RES_GW(*res) &&
1814 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1815 rt->rt_gateway = FIB_RES_GW(*res);
1816 rt_init_metrics(rt, fl4, fi);
1817 #ifdef CONFIG_IP_ROUTE_CLASSID
1818 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1822 if (dst_mtu(dst) > IP_MAX_MTU)
1823 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1824 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1825 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1827 #ifdef CONFIG_IP_ROUTE_CLASSID
1828 #ifdef CONFIG_IP_MULTIPLE_TABLES
1829 set_class_tag(rt, fib_rules_tclass(res));
1831 set_class_tag(rt, itag);
1835 static struct rtable *rt_dst_alloc(struct net_device *dev,
1836 bool nopolicy, bool noxfrm)
1838 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
1840 (nopolicy ? DST_NOPOLICY : 0) |
1841 (noxfrm ? DST_NOXFRM : 0));
1844 /* called in rcu_read_lock() section */
1845 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1846 u8 tos, struct net_device *dev, int our)
1851 struct in_device *in_dev = __in_dev_get_rcu(dev);
1855 /* Primary sanity checks. */
1860 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1861 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1864 if (ipv4_is_zeronet(saddr)) {
1865 if (!ipv4_is_local_multicast(daddr))
1867 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1869 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
1874 rth = rt_dst_alloc(init_net.loopback_dev,
1875 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1879 #ifdef CONFIG_IP_ROUTE_CLASSID
1880 rth->dst.tclassid = itag;
1882 rth->dst.output = ip_rt_bug;
1884 rth->rt_key_dst = daddr;
1885 rth->rt_key_src = saddr;
1886 rth->rt_genid = rt_genid(dev_net(dev));
1887 rth->rt_flags = RTCF_MULTICAST;
1888 rth->rt_type = RTN_MULTICAST;
1889 rth->rt_key_tos = tos;
1890 rth->rt_dst = daddr;
1891 rth->rt_src = saddr;
1892 rth->rt_route_iif = dev->ifindex;
1893 rth->rt_iif = dev->ifindex;
1895 rth->rt_mark = skb->mark;
1896 rth->rt_gateway = daddr;
1897 rth->rt_spec_dst= spec_dst;
1898 rth->rt_peer_genid = 0;
1902 rth->dst.input= ip_local_deliver;
1903 rth->rt_flags |= RTCF_LOCAL;
1906 #ifdef CONFIG_IP_MROUTE
1907 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1908 rth->dst.input = ip_mr_input;
1910 RT_CACHE_STAT_INC(in_slow_mc);
1912 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1913 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
1927 static void ip_handle_martian_source(struct net_device *dev,
1928 struct in_device *in_dev,
1929 struct sk_buff *skb,
1933 RT_CACHE_STAT_INC(in_martian_src);
1934 #ifdef CONFIG_IP_ROUTE_VERBOSE
1935 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1937 * RFC1812 recommendation, if source is martian,
1938 * the only hint is MAC header.
1940 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1941 &daddr, &saddr, dev->name);
1942 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1944 const unsigned char *p = skb_mac_header(skb);
1945 printk(KERN_WARNING "ll header: ");
1946 for (i = 0; i < dev->hard_header_len; i++, p++) {
1948 if (i < (dev->hard_header_len - 1))
1957 /* called in rcu_read_lock() section */
1958 static int __mkroute_input(struct sk_buff *skb,
1959 const struct fib_result *res,
1960 struct in_device *in_dev,
1961 __be32 daddr, __be32 saddr, u32 tos,
1962 struct rtable **result)
1966 struct in_device *out_dev;
1967 unsigned int flags = 0;
1971 /* get a working reference to the output device */
1972 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1973 if (out_dev == NULL) {
1974 if (net_ratelimit())
1975 printk(KERN_CRIT "Bug in ip_route_input" \
1976 "_slow(). Please, report\n");
1981 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1982 in_dev->dev, &spec_dst, &itag);
1984 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1991 flags |= RTCF_DIRECTSRC;
1993 if (out_dev == in_dev && err &&
1994 (IN_DEV_SHARED_MEDIA(out_dev) ||
1995 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1996 flags |= RTCF_DOREDIRECT;
1998 if (skb->protocol != htons(ETH_P_IP)) {
1999 /* Not IP (i.e. ARP). Do not create route, if it is
2000 * invalid for proxy arp. DNAT routes are always valid.
2002 * Proxy arp feature have been extended to allow, ARP
2003 * replies back to the same interface, to support
2004 * Private VLAN switch technologies. See arp.c.
2006 if (out_dev == in_dev &&
2007 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2013 rth = rt_dst_alloc(out_dev->dev,
2014 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2015 IN_DEV_CONF_GET(out_dev, NOXFRM));
2021 rth->rt_key_dst = daddr;
2022 rth->rt_key_src = saddr;
2023 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2024 rth->rt_flags = flags;
2025 rth->rt_type = res->type;
2026 rth->rt_key_tos = tos;
2027 rth->rt_dst = daddr;
2028 rth->rt_src = saddr;
2029 rth->rt_route_iif = in_dev->dev->ifindex;
2030 rth->rt_iif = in_dev->dev->ifindex;
2032 rth->rt_mark = skb->mark;
2033 rth->rt_gateway = daddr;
2034 rth->rt_spec_dst= spec_dst;
2035 rth->rt_peer_genid = 0;
2039 rth->dst.input = ip_forward;
2040 rth->dst.output = ip_output;
2042 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2050 static int ip_mkroute_input(struct sk_buff *skb,
2051 struct fib_result *res,
2052 const struct flowi4 *fl4,
2053 struct in_device *in_dev,
2054 __be32 daddr, __be32 saddr, u32 tos)
2056 struct rtable* rth = NULL;
2060 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2061 if (res->fi && res->fi->fib_nhs > 1)
2062 fib_select_multipath(res);
2065 /* create a routing cache entry */
2066 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2070 /* put it into the cache */
2071 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2072 rt_genid(dev_net(rth->dst.dev)));
2073 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2075 return PTR_ERR(rth);
2080 * NOTE. We drop all the packets that has local source
2081 * addresses, because every properly looped back packet
2082 * must have correct destination already attached by output routine.
2084 * Such approach solves two big problems:
2085 * 1. Not simplex devices are handled properly.
2086 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2087 * called with rcu_read_lock()
2090 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2091 u8 tos, struct net_device *dev)
2093 struct fib_result res;
2094 struct in_device *in_dev = __in_dev_get_rcu(dev);
2098 struct rtable * rth;
2102 struct net * net = dev_net(dev);
2104 /* IP on this device is disabled. */
2109 /* Check for the most weird martians, which can be not detected
2113 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2114 ipv4_is_loopback(saddr))
2115 goto martian_source;
2117 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2120 /* Accept zero addresses only to limited broadcast;
2121 * I even do not know to fix it or not. Waiting for complains :-)
2123 if (ipv4_is_zeronet(saddr))
2124 goto martian_source;
2126 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2127 goto martian_destination;
2130 * Now we are ready to route packet.
2133 fl4.flowi4_iif = dev->ifindex;
2134 fl4.flowi4_mark = skb->mark;
2135 fl4.flowi4_tos = tos;
2136 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2139 err = fib_lookup(net, &fl4, &res);
2141 if (!IN_DEV_FORWARD(in_dev))
2146 RT_CACHE_STAT_INC(in_slow_tot);
2148 if (res.type == RTN_BROADCAST)
2151 if (res.type == RTN_LOCAL) {
2152 err = fib_validate_source(skb, saddr, daddr, tos,
2153 net->loopback_dev->ifindex,
2154 dev, &spec_dst, &itag);
2156 goto martian_source_keep_err;
2158 flags |= RTCF_DIRECTSRC;
2163 if (!IN_DEV_FORWARD(in_dev))
2165 if (res.type != RTN_UNICAST)
2166 goto martian_destination;
2168 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2172 if (skb->protocol != htons(ETH_P_IP))
2175 if (ipv4_is_zeronet(saddr))
2176 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2178 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2181 goto martian_source_keep_err;
2183 flags |= RTCF_DIRECTSRC;
2185 flags |= RTCF_BROADCAST;
2186 res.type = RTN_BROADCAST;
2187 RT_CACHE_STAT_INC(in_brd);
2190 rth = rt_dst_alloc(net->loopback_dev,
2191 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2195 rth->dst.input= ip_local_deliver;
2196 rth->dst.output= ip_rt_bug;
2197 #ifdef CONFIG_IP_ROUTE_CLASSID
2198 rth->dst.tclassid = itag;
2201 rth->rt_key_dst = daddr;
2202 rth->rt_key_src = saddr;
2203 rth->rt_genid = rt_genid(net);
2204 rth->rt_flags = flags|RTCF_LOCAL;
2205 rth->rt_type = res.type;
2206 rth->rt_key_tos = tos;
2207 rth->rt_dst = daddr;
2208 rth->rt_src = saddr;
2209 #ifdef CONFIG_IP_ROUTE_CLASSID
2210 rth->dst.tclassid = itag;
2212 rth->rt_route_iif = dev->ifindex;
2213 rth->rt_iif = dev->ifindex;
2215 rth->rt_mark = skb->mark;
2216 rth->rt_gateway = daddr;
2217 rth->rt_spec_dst= spec_dst;
2218 rth->rt_peer_genid = 0;
2221 if (res.type == RTN_UNREACHABLE) {
2222 rth->dst.input= ip_error;
2223 rth->dst.error= -err;
2224 rth->rt_flags &= ~RTCF_LOCAL;
2226 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2227 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2234 RT_CACHE_STAT_INC(in_no_route);
2235 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2236 res.type = RTN_UNREACHABLE;
2242 * Do not cache martian addresses: they should be logged (RFC1812)
2244 martian_destination:
2245 RT_CACHE_STAT_INC(in_martian_dst);
2246 #ifdef CONFIG_IP_ROUTE_VERBOSE
2247 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2248 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2249 &daddr, &saddr, dev->name);
2253 err = -EHOSTUNREACH;
2266 martian_source_keep_err:
2267 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2271 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2272 u8 tos, struct net_device *dev, bool noref)
2274 struct rtable * rth;
2276 int iif = dev->ifindex;
2284 if (!rt_caching(net))
2287 tos &= IPTOS_RT_MASK;
2288 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2290 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2291 rth = rcu_dereference(rth->dst.rt_next)) {
2292 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2293 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2294 (rth->rt_iif ^ iif) |
2296 (rth->rt_key_tos ^ tos)) == 0 &&
2297 rth->rt_mark == skb->mark &&
2298 net_eq(dev_net(rth->dst.dev), net) &&
2299 !rt_is_expired(rth)) {
2301 dst_use_noref(&rth->dst, jiffies);
2302 skb_dst_set_noref(skb, &rth->dst);
2304 dst_use(&rth->dst, jiffies);
2305 skb_dst_set(skb, &rth->dst);
2307 RT_CACHE_STAT_INC(in_hit);
2311 RT_CACHE_STAT_INC(in_hlist_search);
2315 /* Multicast recognition logic is moved from route cache to here.
2316 The problem was that too many Ethernet cards have broken/missing
2317 hardware multicast filters :-( As result the host on multicasting
2318 network acquires a lot of useless route cache entries, sort of
2319 SDR messages from all the world. Now we try to get rid of them.
2320 Really, provided software IP multicast filter is organized
2321 reasonably (at least, hashed), it does not result in a slowdown
2322 comparing with route cache reject entries.
2323 Note, that multicast routers are not affected, because
2324 route cache entry is created eventually.
2326 if (ipv4_is_multicast(daddr)) {
2327 struct in_device *in_dev = __in_dev_get_rcu(dev);
2330 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2331 ip_hdr(skb)->protocol);
2333 #ifdef CONFIG_IP_MROUTE
2335 (!ipv4_is_local_multicast(daddr) &&
2336 IN_DEV_MFORWARD(in_dev))
2339 int res = ip_route_input_mc(skb, daddr, saddr,
2348 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2352 EXPORT_SYMBOL(ip_route_input_common);
2354 /* called with rcu_read_lock() */
2355 static struct rtable *__mkroute_output(const struct fib_result *res,
2356 const struct flowi4 *fl4,
2357 __be32 orig_daddr, __be32 orig_saddr,
2358 int orig_oif, struct net_device *dev_out,
2361 struct fib_info *fi = res->fi;
2362 u32 tos = RT_FL_TOS(fl4);
2363 struct in_device *in_dev;
2364 u16 type = res->type;
2367 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2368 return ERR_PTR(-EINVAL);
2370 if (ipv4_is_lbcast(fl4->daddr))
2371 type = RTN_BROADCAST;
2372 else if (ipv4_is_multicast(fl4->daddr))
2373 type = RTN_MULTICAST;
2374 else if (ipv4_is_zeronet(fl4->daddr))
2375 return ERR_PTR(-EINVAL);
2377 if (dev_out->flags & IFF_LOOPBACK)
2378 flags |= RTCF_LOCAL;
2380 in_dev = __in_dev_get_rcu(dev_out);
2382 return ERR_PTR(-EINVAL);
2384 if (type == RTN_BROADCAST) {
2385 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2387 } else if (type == RTN_MULTICAST) {
2388 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2389 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2391 flags &= ~RTCF_LOCAL;
2392 /* If multicast route do not exist use
2393 * default one, but do not gateway in this case.
2396 if (fi && res->prefixlen < 4)
2400 rth = rt_dst_alloc(dev_out,
2401 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2402 IN_DEV_CONF_GET(in_dev, NOXFRM));
2404 return ERR_PTR(-ENOBUFS);
2406 rth->dst.output = ip_output;
2408 rth->rt_key_dst = orig_daddr;
2409 rth->rt_key_src = orig_saddr;
2410 rth->rt_genid = rt_genid(dev_net(dev_out));
2411 rth->rt_flags = flags;
2412 rth->rt_type = type;
2413 rth->rt_key_tos = tos;
2414 rth->rt_dst = fl4->daddr;
2415 rth->rt_src = fl4->saddr;
2416 rth->rt_route_iif = 0;
2417 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2418 rth->rt_oif = orig_oif;
2419 rth->rt_mark = fl4->flowi4_mark;
2420 rth->rt_gateway = fl4->daddr;
2421 rth->rt_spec_dst= fl4->saddr;
2422 rth->rt_peer_genid = 0;
2426 RT_CACHE_STAT_INC(out_slow_tot);
2428 if (flags & RTCF_LOCAL) {
2429 rth->dst.input = ip_local_deliver;
2430 rth->rt_spec_dst = fl4->daddr;
2432 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2433 rth->rt_spec_dst = fl4->saddr;
2434 if (flags & RTCF_LOCAL &&
2435 !(dev_out->flags & IFF_LOOPBACK)) {
2436 rth->dst.output = ip_mc_output;
2437 RT_CACHE_STAT_INC(out_slow_mc);
2439 #ifdef CONFIG_IP_MROUTE
2440 if (type == RTN_MULTICAST) {
2441 if (IN_DEV_MFORWARD(in_dev) &&
2442 !ipv4_is_local_multicast(fl4->daddr)) {
2443 rth->dst.input = ip_mr_input;
2444 rth->dst.output = ip_mc_output;
2450 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2456 * Major route resolver routine.
2457 * called with rcu_read_lock();
2460 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2462 struct net_device *dev_out = NULL;
2463 u32 tos = RT_FL_TOS(fl4);
2464 unsigned int flags = 0;
2465 struct fib_result res;
2472 #ifdef CONFIG_IP_MULTIPLE_TABLES
2476 orig_daddr = fl4->daddr;
2477 orig_saddr = fl4->saddr;
2478 orig_oif = fl4->flowi4_oif;
2480 fl4->flowi4_iif = net->loopback_dev->ifindex;
2481 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2482 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2483 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2487 rth = ERR_PTR(-EINVAL);
2488 if (ipv4_is_multicast(fl4->saddr) ||
2489 ipv4_is_lbcast(fl4->saddr) ||
2490 ipv4_is_zeronet(fl4->saddr))
2493 /* I removed check for oif == dev_out->oif here.
2494 It was wrong for two reasons:
2495 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2496 is assigned to multiple interfaces.
2497 2. Moreover, we are allowed to send packets with saddr
2498 of another iface. --ANK
2501 if (fl4->flowi4_oif == 0 &&
2502 (ipv4_is_multicast(fl4->daddr) ||
2503 ipv4_is_lbcast(fl4->daddr))) {
2504 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2505 dev_out = __ip_dev_find(net, fl4->saddr, false);
2506 if (dev_out == NULL)
2509 /* Special hack: user can direct multicasts
2510 and limited broadcast via necessary interface
2511 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2512 This hack is not just for fun, it allows
2513 vic,vat and friends to work.
2514 They bind socket to loopback, set ttl to zero
2515 and expect that it will work.
2516 From the viewpoint of routing cache they are broken,
2517 because we are not allowed to build multicast path
2518 with loopback source addr (look, routing cache
2519 cannot know, that ttl is zero, so that packet
2520 will not leave this host and route is valid).
2521 Luckily, this hack is good workaround.
2524 fl4->flowi4_oif = dev_out->ifindex;
2528 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2529 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2530 if (!__ip_dev_find(net, fl4->saddr, false))
2536 if (fl4->flowi4_oif) {
2537 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2538 rth = ERR_PTR(-ENODEV);
2539 if (dev_out == NULL)
2542 /* RACE: Check return value of inet_select_addr instead. */
2543 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2544 rth = ERR_PTR(-ENETUNREACH);
2547 if (ipv4_is_local_multicast(fl4->daddr) ||
2548 ipv4_is_lbcast(fl4->daddr)) {
2550 fl4->saddr = inet_select_addr(dev_out, 0,
2555 if (ipv4_is_multicast(fl4->daddr))
2556 fl4->saddr = inet_select_addr(dev_out, 0,
2558 else if (!fl4->daddr)
2559 fl4->saddr = inet_select_addr(dev_out, 0,
2565 fl4->daddr = fl4->saddr;
2567 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2568 dev_out = net->loopback_dev;
2569 fl4->flowi4_oif = net->loopback_dev->ifindex;
2570 res.type = RTN_LOCAL;
2571 flags |= RTCF_LOCAL;
2575 if (fib_lookup(net, fl4, &res)) {
2577 if (fl4->flowi4_oif) {
2578 /* Apparently, routing tables are wrong. Assume,
2579 that the destination is on link.
2582 Because we are allowed to send to iface
2583 even if it has NO routes and NO assigned
2584 addresses. When oif is specified, routing
2585 tables are looked up with only one purpose:
2586 to catch if destination is gatewayed, rather than
2587 direct. Moreover, if MSG_DONTROUTE is set,
2588 we send packet, ignoring both routing tables
2589 and ifaddr state. --ANK
2592 We could make it even if oif is unknown,
2593 likely IPv6, but we do not.
2596 if (fl4->saddr == 0)
2597 fl4->saddr = inet_select_addr(dev_out, 0,
2599 res.type = RTN_UNICAST;
2602 rth = ERR_PTR(-ENETUNREACH);
2606 if (res.type == RTN_LOCAL) {
2608 if (res.fi->fib_prefsrc)
2609 fl4->saddr = res.fi->fib_prefsrc;
2611 fl4->saddr = fl4->daddr;
2613 dev_out = net->loopback_dev;
2614 fl4->flowi4_oif = dev_out->ifindex;
2616 flags |= RTCF_LOCAL;
2620 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2621 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2622 fib_select_multipath(&res);
2625 if (!res.prefixlen &&
2626 res.table->tb_num_default > 1 &&
2627 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2628 fib_select_default(&res);
2631 fl4->saddr = FIB_RES_PREFSRC(net, res);
2633 dev_out = FIB_RES_DEV(res);
2634 fl4->flowi4_oif = dev_out->ifindex;
2638 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2643 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2644 rt_genid(dev_net(dev_out)));
2645 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2653 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2658 if (!rt_caching(net))
2661 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2664 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2665 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2666 if (rth->rt_key_dst == flp4->daddr &&
2667 rth->rt_key_src == flp4->saddr &&
2668 rt_is_output_route(rth) &&
2669 rth->rt_oif == flp4->flowi4_oif &&
2670 rth->rt_mark == flp4->flowi4_mark &&
2671 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2672 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2673 net_eq(dev_net(rth->dst.dev), net) &&
2674 !rt_is_expired(rth)) {
2675 dst_use(&rth->dst, jiffies);
2676 RT_CACHE_STAT_INC(out_hit);
2677 rcu_read_unlock_bh();
2679 flp4->saddr = rth->rt_src;
2681 flp4->daddr = rth->rt_dst;
2684 RT_CACHE_STAT_INC(out_hlist_search);
2686 rcu_read_unlock_bh();
2689 return ip_route_output_slow(net, flp4);
2691 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2693 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2698 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst)
2703 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2707 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2713 static struct dst_ops ipv4_dst_blackhole_ops = {
2715 .protocol = cpu_to_be16(ETH_P_IP),
2716 .destroy = ipv4_dst_destroy,
2717 .check = ipv4_blackhole_dst_check,
2718 .default_mtu = ipv4_blackhole_default_mtu,
2719 .default_advmss = ipv4_default_advmss,
2720 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2721 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2724 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2726 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2727 struct rtable *ort = (struct rtable *) dst_orig;
2730 struct dst_entry *new = &rt->dst;
2733 new->input = dst_discard;
2734 new->output = dst_discard;
2735 dst_copy_metrics(new, &ort->dst);
2737 new->dev = ort->dst.dev;
2741 rt->rt_key_dst = ort->rt_key_dst;
2742 rt->rt_key_src = ort->rt_key_src;
2743 rt->rt_key_tos = ort->rt_key_tos;
2744 rt->rt_route_iif = ort->rt_route_iif;
2745 rt->rt_iif = ort->rt_iif;
2746 rt->rt_oif = ort->rt_oif;
2747 rt->rt_mark = ort->rt_mark;
2749 rt->rt_genid = rt_genid(net);
2750 rt->rt_flags = ort->rt_flags;
2751 rt->rt_type = ort->rt_type;
2752 rt->rt_dst = ort->rt_dst;
2753 rt->rt_src = ort->rt_src;
2754 rt->rt_gateway = ort->rt_gateway;
2755 rt->rt_spec_dst = ort->rt_spec_dst;
2756 rt->peer = ort->peer;
2758 atomic_inc(&rt->peer->refcnt);
2761 atomic_inc(&rt->fi->fib_clntref);
2766 dst_release(dst_orig);
2768 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2771 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2774 struct rtable *rt = __ip_route_output_key(net, flp4);
2779 if (flp4->flowi4_proto)
2780 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2781 flowi4_to_flowi(flp4),
2786 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2788 static int rt_fill_info(struct net *net,
2789 struct sk_buff *skb, u32 pid, u32 seq, int event,
2790 int nowait, unsigned int flags)
2792 struct rtable *rt = skb_rtable(skb);
2794 struct nlmsghdr *nlh;
2796 u32 id = 0, ts = 0, tsage = 0, error;
2798 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2802 r = nlmsg_data(nlh);
2803 r->rtm_family = AF_INET;
2804 r->rtm_dst_len = 32;
2806 r->rtm_tos = rt->rt_key_tos;
2807 r->rtm_table = RT_TABLE_MAIN;
2808 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2809 r->rtm_type = rt->rt_type;
2810 r->rtm_scope = RT_SCOPE_UNIVERSE;
2811 r->rtm_protocol = RTPROT_UNSPEC;
2812 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2813 if (rt->rt_flags & RTCF_NOTIFY)
2814 r->rtm_flags |= RTM_F_NOTIFY;
2816 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2818 if (rt->rt_key_src) {
2819 r->rtm_src_len = 32;
2820 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2823 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2824 #ifdef CONFIG_IP_ROUTE_CLASSID
2825 if (rt->dst.tclassid)
2826 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2828 if (rt_is_input_route(rt))
2829 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2830 else if (rt->rt_src != rt->rt_key_src)
2831 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2833 if (rt->rt_dst != rt->rt_gateway)
2834 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2836 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2837 goto nla_put_failure;
2840 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
2842 error = rt->dst.error;
2843 expires = (rt->peer && rt->peer->pmtu_expires) ?
2844 rt->peer->pmtu_expires - jiffies : 0;
2846 inet_peer_refcheck(rt->peer);
2847 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2848 if (rt->peer->tcp_ts_stamp) {
2849 ts = rt->peer->tcp_ts;
2850 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2854 if (rt_is_input_route(rt)) {
2855 #ifdef CONFIG_IP_MROUTE
2856 __be32 dst = rt->rt_dst;
2858 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2859 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2860 int err = ipmr_get_route(net, skb,
2861 rt->rt_src, rt->rt_dst,
2867 goto nla_put_failure;
2869 if (err == -EMSGSIZE)
2870 goto nla_put_failure;
2876 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
2879 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2880 expires, error) < 0)
2881 goto nla_put_failure;
2883 return nlmsg_end(skb, nlh);
2886 nlmsg_cancel(skb, nlh);
2890 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2892 struct net *net = sock_net(in_skb->sk);
2894 struct nlattr *tb[RTA_MAX+1];
2895 struct rtable *rt = NULL;
2901 struct sk_buff *skb;
2903 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2907 rtm = nlmsg_data(nlh);
2909 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2915 /* Reserve room for dummy headers, this skb can pass
2916 through good chunk of routing engine.
2918 skb_reset_mac_header(skb);
2919 skb_reset_network_header(skb);
2921 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2922 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2923 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2925 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2926 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2927 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2928 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2931 struct net_device *dev;
2933 dev = __dev_get_by_index(net, iif);
2939 skb->protocol = htons(ETH_P_IP);
2943 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2946 rt = skb_rtable(skb);
2947 if (err == 0 && rt->dst.error)
2948 err = -rt->dst.error;
2950 struct flowi4 fl4 = {
2953 .flowi4_tos = rtm->rtm_tos,
2954 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2955 .flowi4_mark = mark,
2957 rt = ip_route_output_key(net, &fl4);
2967 skb_dst_set(skb, &rt->dst);
2968 if (rtm->rtm_flags & RTM_F_NOTIFY)
2969 rt->rt_flags |= RTCF_NOTIFY;
2971 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2972 RTM_NEWROUTE, 0, 0);
2976 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2985 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2992 net = sock_net(skb->sk);
2997 s_idx = idx = cb->args[1];
2998 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
2999 if (!rt_hash_table[h].chain)
3002 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3003 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3004 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3006 if (rt_is_expired(rt))
3008 skb_dst_set_noref(skb, &rt->dst);
3009 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3010 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3011 1, NLM_F_MULTI) <= 0) {
3013 rcu_read_unlock_bh();
3018 rcu_read_unlock_bh();
3027 void ip_rt_multicast_event(struct in_device *in_dev)
3029 rt_cache_flush(dev_net(in_dev->dev), 0);
3032 #ifdef CONFIG_SYSCTL
3033 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3034 void __user *buffer,
3035 size_t *lenp, loff_t *ppos)
3042 memcpy(&ctl, __ctl, sizeof(ctl));
3043 ctl.data = &flush_delay;
3044 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3046 net = (struct net *)__ctl->extra1;
3047 rt_cache_flush(net, flush_delay);
3054 static ctl_table ipv4_route_table[] = {
3056 .procname = "gc_thresh",
3057 .data = &ipv4_dst_ops.gc_thresh,
3058 .maxlen = sizeof(int),
3060 .proc_handler = proc_dointvec,
3063 .procname = "max_size",
3064 .data = &ip_rt_max_size,
3065 .maxlen = sizeof(int),
3067 .proc_handler = proc_dointvec,
3070 /* Deprecated. Use gc_min_interval_ms */
3072 .procname = "gc_min_interval",
3073 .data = &ip_rt_gc_min_interval,
3074 .maxlen = sizeof(int),
3076 .proc_handler = proc_dointvec_jiffies,
3079 .procname = "gc_min_interval_ms",
3080 .data = &ip_rt_gc_min_interval,
3081 .maxlen = sizeof(int),
3083 .proc_handler = proc_dointvec_ms_jiffies,
3086 .procname = "gc_timeout",
3087 .data = &ip_rt_gc_timeout,
3088 .maxlen = sizeof(int),
3090 .proc_handler = proc_dointvec_jiffies,
3093 .procname = "gc_interval",
3094 .data = &ip_rt_gc_interval,
3095 .maxlen = sizeof(int),
3097 .proc_handler = proc_dointvec_jiffies,
3100 .procname = "redirect_load",
3101 .data = &ip_rt_redirect_load,
3102 .maxlen = sizeof(int),
3104 .proc_handler = proc_dointvec,
3107 .procname = "redirect_number",
3108 .data = &ip_rt_redirect_number,
3109 .maxlen = sizeof(int),
3111 .proc_handler = proc_dointvec,
3114 .procname = "redirect_silence",
3115 .data = &ip_rt_redirect_silence,
3116 .maxlen = sizeof(int),
3118 .proc_handler = proc_dointvec,
3121 .procname = "error_cost",
3122 .data = &ip_rt_error_cost,
3123 .maxlen = sizeof(int),
3125 .proc_handler = proc_dointvec,
3128 .procname = "error_burst",
3129 .data = &ip_rt_error_burst,
3130 .maxlen = sizeof(int),
3132 .proc_handler = proc_dointvec,
3135 .procname = "gc_elasticity",
3136 .data = &ip_rt_gc_elasticity,
3137 .maxlen = sizeof(int),
3139 .proc_handler = proc_dointvec,
3142 .procname = "mtu_expires",
3143 .data = &ip_rt_mtu_expires,
3144 .maxlen = sizeof(int),
3146 .proc_handler = proc_dointvec_jiffies,
3149 .procname = "min_pmtu",
3150 .data = &ip_rt_min_pmtu,
3151 .maxlen = sizeof(int),
3153 .proc_handler = proc_dointvec,
3156 .procname = "min_adv_mss",
3157 .data = &ip_rt_min_advmss,
3158 .maxlen = sizeof(int),
3160 .proc_handler = proc_dointvec,
3165 static struct ctl_table empty[1];
3167 static struct ctl_table ipv4_skeleton[] =
3169 { .procname = "route",
3170 .mode = 0555, .child = ipv4_route_table},
3171 { .procname = "neigh",
3172 .mode = 0555, .child = empty},
3176 static __net_initdata struct ctl_path ipv4_path[] = {
3177 { .procname = "net", },
3178 { .procname = "ipv4", },
3182 static struct ctl_table ipv4_route_flush_table[] = {
3184 .procname = "flush",
3185 .maxlen = sizeof(int),
3187 .proc_handler = ipv4_sysctl_rtcache_flush,
3192 static __net_initdata struct ctl_path ipv4_route_path[] = {
3193 { .procname = "net", },
3194 { .procname = "ipv4", },
3195 { .procname = "route", },
3199 static __net_init int sysctl_route_net_init(struct net *net)
3201 struct ctl_table *tbl;
3203 tbl = ipv4_route_flush_table;
3204 if (!net_eq(net, &init_net)) {
3205 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3209 tbl[0].extra1 = net;
3211 net->ipv4.route_hdr =
3212 register_net_sysctl_table(net, ipv4_route_path, tbl);
3213 if (net->ipv4.route_hdr == NULL)
3218 if (tbl != ipv4_route_flush_table)
3224 static __net_exit void sysctl_route_net_exit(struct net *net)
3226 struct ctl_table *tbl;
3228 tbl = net->ipv4.route_hdr->ctl_table_arg;
3229 unregister_net_sysctl_table(net->ipv4.route_hdr);
3230 BUG_ON(tbl == ipv4_route_flush_table);
3234 static __net_initdata struct pernet_operations sysctl_route_ops = {
3235 .init = sysctl_route_net_init,
3236 .exit = sysctl_route_net_exit,
3240 static __net_init int rt_genid_init(struct net *net)
3242 get_random_bytes(&net->ipv4.rt_genid,
3243 sizeof(net->ipv4.rt_genid));
3244 get_random_bytes(&net->ipv4.dev_addr_genid,
3245 sizeof(net->ipv4.dev_addr_genid));
3249 static __net_initdata struct pernet_operations rt_genid_ops = {
3250 .init = rt_genid_init,
3254 #ifdef CONFIG_IP_ROUTE_CLASSID
3255 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3256 #endif /* CONFIG_IP_ROUTE_CLASSID */
3258 static __initdata unsigned long rhash_entries;
3259 static int __init set_rhash_entries(char *str)
3263 rhash_entries = simple_strtoul(str, &str, 0);
3266 __setup("rhash_entries=", set_rhash_entries);
3268 int __init ip_rt_init(void)
3272 #ifdef CONFIG_IP_ROUTE_CLASSID
3273 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3275 panic("IP: failed to allocate ip_rt_acct\n");
3278 ipv4_dst_ops.kmem_cachep =
3279 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3280 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3282 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3284 if (dst_entries_init(&ipv4_dst_ops) < 0)
3285 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3287 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3288 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3290 rt_hash_table = (struct rt_hash_bucket *)
3291 alloc_large_system_hash("IP route cache",
3292 sizeof(struct rt_hash_bucket),
3294 (totalram_pages >= 128 * 1024) ?
3299 rhash_entries ? 0 : 512 * 1024);
3300 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3301 rt_hash_lock_init();
3303 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3304 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3309 if (ip_rt_proc_init())
3310 printk(KERN_ERR "Unable to create route proc files\n");
3313 xfrm4_init(ip_rt_max_size);
3315 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3317 #ifdef CONFIG_SYSCTL
3318 register_pernet_subsys(&sysctl_route_ops);
3320 register_pernet_subsys(&rt_genid_ops);
3324 #ifdef CONFIG_SYSCTL
3326 * We really need to sanitize the damn ipv4 init order, then all
3327 * this nonsense will go away.
3329 void __init ip_static_sysctl_init(void)
3331 register_sysctl_paths(ipv4_path, ipv4_skeleton);