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>
111 #include <net/atmclip.h>
112 #include <net/secure_seq.h>
114 #define RT_FL_TOS(oldflp4) \
115 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
117 #define IP_MAX_MTU 0xFFF0
119 #define RT_GC_TIMEOUT (300*HZ)
121 static int ip_rt_max_size;
122 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
123 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
124 static int ip_rt_redirect_number __read_mostly = 9;
125 static int ip_rt_redirect_load __read_mostly = HZ / 50;
126 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
127 static int ip_rt_error_cost __read_mostly = HZ;
128 static int ip_rt_error_burst __read_mostly = 5 * HZ;
129 static int ip_rt_gc_elasticity __read_mostly = 8;
130 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
131 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
132 static int ip_rt_min_advmss __read_mostly = 256;
133 static int rt_chain_length_max __read_mostly = 20;
134 static int redirect_genid;
137 * Interface to generic destination cache.
140 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
141 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
142 static unsigned int ipv4_mtu(const struct dst_entry *dst);
143 static void ipv4_dst_destroy(struct dst_entry *dst);
144 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
145 static void ipv4_link_failure(struct sk_buff *skb);
146 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
147 static int rt_garbage_collect(struct dst_ops *ops);
149 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
154 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
156 struct rtable *rt = (struct rtable *) dst;
157 struct inet_peer *peer;
161 rt_bind_peer(rt, rt->rt_dst, 1);
165 u32 *old_p = __DST_METRICS_PTR(old);
166 unsigned long prev, new;
169 if (inet_metrics_new(peer))
170 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
172 new = (unsigned long) p;
173 prev = cmpxchg(&dst->_metrics, old, new);
176 p = __DST_METRICS_PTR(prev);
177 if (prev & DST_METRICS_READ_ONLY)
181 fib_info_put(rt->fi);
189 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr);
191 static struct dst_ops ipv4_dst_ops = {
193 .protocol = cpu_to_be16(ETH_P_IP),
194 .gc = rt_garbage_collect,
195 .check = ipv4_dst_check,
196 .default_advmss = ipv4_default_advmss,
198 .cow_metrics = ipv4_cow_metrics,
199 .destroy = ipv4_dst_destroy,
200 .ifdown = ipv4_dst_ifdown,
201 .negative_advice = ipv4_negative_advice,
202 .link_failure = ipv4_link_failure,
203 .update_pmtu = ip_rt_update_pmtu,
204 .local_out = __ip_local_out,
205 .neigh_lookup = ipv4_neigh_lookup,
208 #define ECN_OR_COST(class) TC_PRIO_##class
210 const __u8 ip_tos2prio[16] = {
212 ECN_OR_COST(BESTEFFORT),
214 ECN_OR_COST(BESTEFFORT),
220 ECN_OR_COST(INTERACTIVE),
222 ECN_OR_COST(INTERACTIVE),
223 TC_PRIO_INTERACTIVE_BULK,
224 ECN_OR_COST(INTERACTIVE_BULK),
225 TC_PRIO_INTERACTIVE_BULK,
226 ECN_OR_COST(INTERACTIVE_BULK)
234 /* The locking scheme is rather straight forward:
236 * 1) Read-Copy Update protects the buckets of the central route hash.
237 * 2) Only writers remove entries, and they hold the lock
238 * as they look at rtable reference counts.
239 * 3) Only readers acquire references to rtable entries,
240 * they do so with atomic increments and with the
244 struct rt_hash_bucket {
245 struct rtable __rcu *chain;
248 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
249 defined(CONFIG_PROVE_LOCKING)
251 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
252 * The size of this table is a power of two and depends on the number of CPUS.
253 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
255 #ifdef CONFIG_LOCKDEP
256 # define RT_HASH_LOCK_SZ 256
259 # define RT_HASH_LOCK_SZ 4096
261 # define RT_HASH_LOCK_SZ 2048
263 # define RT_HASH_LOCK_SZ 1024
265 # define RT_HASH_LOCK_SZ 512
267 # define RT_HASH_LOCK_SZ 256
271 static spinlock_t *rt_hash_locks;
272 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
274 static __init void rt_hash_lock_init(void)
278 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
281 panic("IP: failed to allocate rt_hash_locks\n");
283 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
284 spin_lock_init(&rt_hash_locks[i]);
287 # define rt_hash_lock_addr(slot) NULL
289 static inline void rt_hash_lock_init(void)
294 static struct rt_hash_bucket *rt_hash_table __read_mostly;
295 static unsigned rt_hash_mask __read_mostly;
296 static unsigned int rt_hash_log __read_mostly;
298 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
299 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
301 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
304 return jhash_3words((__force u32)daddr, (__force u32)saddr,
309 static inline int rt_genid(struct net *net)
311 return atomic_read(&net->ipv4.rt_genid);
314 #ifdef CONFIG_PROC_FS
315 struct rt_cache_iter_state {
316 struct seq_net_private p;
321 static struct rtable *rt_cache_get_first(struct seq_file *seq)
323 struct rt_cache_iter_state *st = seq->private;
324 struct rtable *r = NULL;
326 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
327 if (!rcu_access_pointer(rt_hash_table[st->bucket].chain))
330 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
332 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
333 r->rt_genid == st->genid)
335 r = rcu_dereference_bh(r->dst.rt_next);
337 rcu_read_unlock_bh();
342 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
345 struct rt_cache_iter_state *st = seq->private;
347 r = rcu_dereference_bh(r->dst.rt_next);
349 rcu_read_unlock_bh();
351 if (--st->bucket < 0)
353 } while (!rcu_access_pointer(rt_hash_table[st->bucket].chain));
355 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
360 static struct rtable *rt_cache_get_next(struct seq_file *seq,
363 struct rt_cache_iter_state *st = seq->private;
364 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
365 if (dev_net(r->dst.dev) != seq_file_net(seq))
367 if (r->rt_genid == st->genid)
373 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
375 struct rtable *r = rt_cache_get_first(seq);
378 while (pos && (r = rt_cache_get_next(seq, r)))
380 return pos ? NULL : r;
383 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
385 struct rt_cache_iter_state *st = seq->private;
387 return rt_cache_get_idx(seq, *pos - 1);
388 st->genid = rt_genid(seq_file_net(seq));
389 return SEQ_START_TOKEN;
392 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
396 if (v == SEQ_START_TOKEN)
397 r = rt_cache_get_first(seq);
399 r = rt_cache_get_next(seq, v);
404 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
406 if (v && v != SEQ_START_TOKEN)
407 rcu_read_unlock_bh();
410 static int rt_cache_seq_show(struct seq_file *seq, void *v)
412 if (v == SEQ_START_TOKEN)
413 seq_printf(seq, "%-127s\n",
414 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
415 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
418 struct rtable *r = v;
423 n = dst_get_neighbour(&r->dst);
424 HHUptod = (n && (n->nud_state & NUD_CONNECTED)) ? 1 : 0;
427 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
428 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
429 r->dst.dev ? r->dst.dev->name : "*",
430 (__force u32)r->rt_dst,
431 (__force u32)r->rt_gateway,
432 r->rt_flags, atomic_read(&r->dst.__refcnt),
433 r->dst.__use, 0, (__force u32)r->rt_src,
434 dst_metric_advmss(&r->dst) + 40,
435 dst_metric(&r->dst, RTAX_WINDOW),
436 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
437 dst_metric(&r->dst, RTAX_RTTVAR)),
441 r->rt_spec_dst, &len);
443 seq_printf(seq, "%*s\n", 127 - len, "");
448 static const struct seq_operations rt_cache_seq_ops = {
449 .start = rt_cache_seq_start,
450 .next = rt_cache_seq_next,
451 .stop = rt_cache_seq_stop,
452 .show = rt_cache_seq_show,
455 static int rt_cache_seq_open(struct inode *inode, struct file *file)
457 return seq_open_net(inode, file, &rt_cache_seq_ops,
458 sizeof(struct rt_cache_iter_state));
461 static const struct file_operations rt_cache_seq_fops = {
462 .owner = THIS_MODULE,
463 .open = rt_cache_seq_open,
466 .release = seq_release_net,
470 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
475 return SEQ_START_TOKEN;
477 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
478 if (!cpu_possible(cpu))
481 return &per_cpu(rt_cache_stat, cpu);
486 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
490 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
491 if (!cpu_possible(cpu))
494 return &per_cpu(rt_cache_stat, cpu);
500 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
505 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
507 struct rt_cache_stat *st = v;
509 if (v == SEQ_START_TOKEN) {
510 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
514 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
515 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
516 dst_entries_get_slow(&ipv4_dst_ops),
539 static const struct seq_operations rt_cpu_seq_ops = {
540 .start = rt_cpu_seq_start,
541 .next = rt_cpu_seq_next,
542 .stop = rt_cpu_seq_stop,
543 .show = rt_cpu_seq_show,
547 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
549 return seq_open(file, &rt_cpu_seq_ops);
552 static const struct file_operations rt_cpu_seq_fops = {
553 .owner = THIS_MODULE,
554 .open = rt_cpu_seq_open,
557 .release = seq_release,
560 #ifdef CONFIG_IP_ROUTE_CLASSID
561 static int rt_acct_proc_show(struct seq_file *m, void *v)
563 struct ip_rt_acct *dst, *src;
566 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
570 for_each_possible_cpu(i) {
571 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
572 for (j = 0; j < 256; j++) {
573 dst[j].o_bytes += src[j].o_bytes;
574 dst[j].o_packets += src[j].o_packets;
575 dst[j].i_bytes += src[j].i_bytes;
576 dst[j].i_packets += src[j].i_packets;
580 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
585 static int rt_acct_proc_open(struct inode *inode, struct file *file)
587 return single_open(file, rt_acct_proc_show, NULL);
590 static const struct file_operations rt_acct_proc_fops = {
591 .owner = THIS_MODULE,
592 .open = rt_acct_proc_open,
595 .release = single_release,
599 static int __net_init ip_rt_do_proc_init(struct net *net)
601 struct proc_dir_entry *pde;
603 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
608 pde = proc_create("rt_cache", S_IRUGO,
609 net->proc_net_stat, &rt_cpu_seq_fops);
613 #ifdef CONFIG_IP_ROUTE_CLASSID
614 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
620 #ifdef CONFIG_IP_ROUTE_CLASSID
622 remove_proc_entry("rt_cache", net->proc_net_stat);
625 remove_proc_entry("rt_cache", net->proc_net);
630 static void __net_exit ip_rt_do_proc_exit(struct net *net)
632 remove_proc_entry("rt_cache", net->proc_net_stat);
633 remove_proc_entry("rt_cache", net->proc_net);
634 #ifdef CONFIG_IP_ROUTE_CLASSID
635 remove_proc_entry("rt_acct", net->proc_net);
639 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
640 .init = ip_rt_do_proc_init,
641 .exit = ip_rt_do_proc_exit,
644 static int __init ip_rt_proc_init(void)
646 return register_pernet_subsys(&ip_rt_proc_ops);
650 static inline int ip_rt_proc_init(void)
654 #endif /* CONFIG_PROC_FS */
656 static inline void rt_free(struct rtable *rt)
658 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
661 static inline void rt_drop(struct rtable *rt)
664 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
667 static inline int rt_fast_clean(struct rtable *rth)
669 /* Kill broadcast/multicast entries very aggresively, if they
670 collide in hash table with more useful entries */
671 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
672 rt_is_input_route(rth) && rth->dst.rt_next;
675 static inline int rt_valuable(struct rtable *rth)
677 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
678 (rth->peer && rth->peer->pmtu_expires);
681 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
686 if (atomic_read(&rth->dst.__refcnt))
689 age = jiffies - rth->dst.lastuse;
690 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
691 (age <= tmo2 && rt_valuable(rth)))
697 /* Bits of score are:
699 * 30: not quite useless
700 * 29..0: usage counter
702 static inline u32 rt_score(struct rtable *rt)
704 u32 score = jiffies - rt->dst.lastuse;
706 score = ~score & ~(3<<30);
711 if (rt_is_output_route(rt) ||
712 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
718 static inline bool rt_caching(const struct net *net)
720 return net->ipv4.current_rt_cache_rebuild_count <=
721 net->ipv4.sysctl_rt_cache_rebuild_count;
724 static inline bool compare_hash_inputs(const struct rtable *rt1,
725 const struct rtable *rt2)
727 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
728 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
729 (rt1->rt_route_iif ^ rt2->rt_route_iif)) == 0);
732 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
734 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
735 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
736 (rt1->rt_mark ^ rt2->rt_mark) |
737 (rt1->rt_key_tos ^ rt2->rt_key_tos) |
738 (rt1->rt_route_iif ^ rt2->rt_route_iif) |
739 (rt1->rt_oif ^ rt2->rt_oif)) == 0;
742 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
744 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
747 static inline int rt_is_expired(struct rtable *rth)
749 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
753 * Perform a full scan of hash table and free all entries.
754 * Can be called by a softirq or a process.
755 * In the later case, we want to be reschedule if necessary
757 static void rt_do_flush(struct net *net, int process_context)
760 struct rtable *rth, *next;
762 for (i = 0; i <= rt_hash_mask; i++) {
763 struct rtable __rcu **pprev;
766 if (process_context && need_resched())
768 rth = rcu_access_pointer(rt_hash_table[i].chain);
772 spin_lock_bh(rt_hash_lock_addr(i));
775 pprev = &rt_hash_table[i].chain;
776 rth = rcu_dereference_protected(*pprev,
777 lockdep_is_held(rt_hash_lock_addr(i)));
780 next = rcu_dereference_protected(rth->dst.rt_next,
781 lockdep_is_held(rt_hash_lock_addr(i)));
784 net_eq(dev_net(rth->dst.dev), net)) {
785 rcu_assign_pointer(*pprev, next);
786 rcu_assign_pointer(rth->dst.rt_next, list);
789 pprev = &rth->dst.rt_next;
794 spin_unlock_bh(rt_hash_lock_addr(i));
796 for (; list; list = next) {
797 next = rcu_dereference_protected(list->dst.rt_next, 1);
804 * While freeing expired entries, we compute average chain length
805 * and standard deviation, using fixed-point arithmetic.
806 * This to have an estimation of rt_chain_length_max
807 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
808 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
812 #define ONE (1UL << FRACT_BITS)
815 * Given a hash chain and an item in this hash chain,
816 * find if a previous entry has the same hash_inputs
817 * (but differs on tos, mark or oif)
818 * Returns 0 if an alias is found.
819 * Returns ONE if rth has no alias before itself.
821 static int has_noalias(const struct rtable *head, const struct rtable *rth)
823 const struct rtable *aux = head;
826 if (compare_hash_inputs(aux, rth))
828 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
834 * Perturbation of rt_genid by a small quantity [1..256]
835 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
836 * many times (2^24) without giving recent rt_genid.
837 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
839 static void rt_cache_invalidate(struct net *net)
841 unsigned char shuffle;
843 get_random_bytes(&shuffle, sizeof(shuffle));
844 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
849 * delay < 0 : invalidate cache (fast : entries will be deleted later)
850 * delay >= 0 : invalidate & flush cache (can be long)
852 void rt_cache_flush(struct net *net, int delay)
854 rt_cache_invalidate(net);
856 rt_do_flush(net, !in_softirq());
859 /* Flush previous cache invalidated entries from the cache */
860 void rt_cache_flush_batch(struct net *net)
862 rt_do_flush(net, !in_softirq());
865 static void rt_emergency_hash_rebuild(struct net *net)
868 printk(KERN_WARNING "Route hash chain too long!\n");
869 rt_cache_invalidate(net);
873 Short description of GC goals.
875 We want to build algorithm, which will keep routing cache
876 at some equilibrium point, when number of aged off entries
877 is kept approximately equal to newly generated ones.
879 Current expiration strength is variable "expire".
880 We try to adjust it dynamically, so that if networking
881 is idle expires is large enough to keep enough of warm entries,
882 and when load increases it reduces to limit cache size.
885 static int rt_garbage_collect(struct dst_ops *ops)
887 static unsigned long expire = RT_GC_TIMEOUT;
888 static unsigned long last_gc;
890 static int equilibrium;
892 struct rtable __rcu **rthp;
893 unsigned long now = jiffies;
895 int entries = dst_entries_get_fast(&ipv4_dst_ops);
898 * Garbage collection is pretty expensive,
899 * do not make it too frequently.
902 RT_CACHE_STAT_INC(gc_total);
904 if (now - last_gc < ip_rt_gc_min_interval &&
905 entries < ip_rt_max_size) {
906 RT_CACHE_STAT_INC(gc_ignored);
910 entries = dst_entries_get_slow(&ipv4_dst_ops);
911 /* Calculate number of entries, which we want to expire now. */
912 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
914 if (equilibrium < ipv4_dst_ops.gc_thresh)
915 equilibrium = ipv4_dst_ops.gc_thresh;
916 goal = entries - equilibrium;
918 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
919 goal = entries - equilibrium;
922 /* We are in dangerous area. Try to reduce cache really
925 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
926 equilibrium = entries - goal;
929 if (now - last_gc >= ip_rt_gc_min_interval)
940 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
941 unsigned long tmo = expire;
943 k = (k + 1) & rt_hash_mask;
944 rthp = &rt_hash_table[k].chain;
945 spin_lock_bh(rt_hash_lock_addr(k));
946 while ((rth = rcu_dereference_protected(*rthp,
947 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
948 if (!rt_is_expired(rth) &&
949 !rt_may_expire(rth, tmo, expire)) {
951 rthp = &rth->dst.rt_next;
954 *rthp = rth->dst.rt_next;
958 spin_unlock_bh(rt_hash_lock_addr(k));
967 /* Goal is not achieved. We stop process if:
969 - if expire reduced to zero. Otherwise, expire is halfed.
970 - if table is not full.
971 - if we are called from interrupt.
972 - jiffies check is just fallback/debug loop breaker.
973 We will not spin here for long time in any case.
976 RT_CACHE_STAT_INC(gc_goal_miss);
983 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
985 } while (!in_softirq() && time_before_eq(jiffies, now));
987 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
989 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
992 printk(KERN_WARNING "dst cache overflow\n");
993 RT_CACHE_STAT_INC(gc_dst_overflow);
997 expire += ip_rt_gc_min_interval;
998 if (expire > ip_rt_gc_timeout ||
999 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
1000 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
1001 expire = ip_rt_gc_timeout;
1006 * Returns number of entries in a hash chain that have different hash_inputs
1008 static int slow_chain_length(const struct rtable *head)
1011 const struct rtable *rth = head;
1014 length += has_noalias(head, rth);
1015 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1017 return length >> FRACT_BITS;
1020 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr)
1022 struct neigh_table *tbl = &arp_tbl;
1023 static const __be32 inaddr_any = 0;
1024 struct net_device *dev = dst->dev;
1025 const __be32 *pkey = daddr;
1026 struct neighbour *n;
1028 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
1029 if (dev->type == ARPHRD_ATM)
1030 tbl = clip_tbl_hook;
1032 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
1035 n = __ipv4_neigh_lookup(tbl, dev, *(__force u32 *)pkey);
1038 return neigh_create(tbl, pkey, dev);
1041 static int rt_bind_neighbour(struct rtable *rt)
1043 struct neighbour *n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
1046 dst_set_neighbour(&rt->dst, n);
1051 static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,
1052 struct sk_buff *skb, int ifindex)
1054 struct rtable *rth, *cand;
1055 struct rtable __rcu **rthp, **candp;
1059 int attempts = !in_softirq();
1063 min_score = ~(u32)0;
1068 if (!rt_caching(dev_net(rt->dst.dev))) {
1070 * If we're not caching, just tell the caller we
1071 * were successful and don't touch the route. The
1072 * caller hold the sole reference to the cache entry, and
1073 * it will be released when the caller is done with it.
1074 * If we drop it here, the callers have no way to resolve routes
1075 * when we're not caching. Instead, just point *rp at rt, so
1076 * the caller gets a single use out of the route
1077 * Note that we do rt_free on this new route entry, so that
1078 * once its refcount hits zero, we are still able to reap it
1080 * Note: To avoid expensive rcu stuff for this uncached dst,
1081 * we set DST_NOCACHE so that dst_release() can free dst without
1082 * waiting a grace period.
1085 rt->dst.flags |= DST_NOCACHE;
1086 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1087 int err = rt_bind_neighbour(rt);
1089 if (net_ratelimit())
1091 "Neighbour table failure & not caching routes.\n");
1093 return ERR_PTR(err);
1100 rthp = &rt_hash_table[hash].chain;
1102 spin_lock_bh(rt_hash_lock_addr(hash));
1103 while ((rth = rcu_dereference_protected(*rthp,
1104 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1105 if (rt_is_expired(rth)) {
1106 *rthp = rth->dst.rt_next;
1110 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1112 *rthp = rth->dst.rt_next;
1114 * Since lookup is lockfree, the deletion
1115 * must be visible to another weakly ordered CPU before
1116 * the insertion at the start of the hash chain.
1118 rcu_assign_pointer(rth->dst.rt_next,
1119 rt_hash_table[hash].chain);
1121 * Since lookup is lockfree, the update writes
1122 * must be ordered for consistency on SMP.
1124 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1126 dst_use(&rth->dst, now);
1127 spin_unlock_bh(rt_hash_lock_addr(hash));
1131 skb_dst_set(skb, &rth->dst);
1135 if (!atomic_read(&rth->dst.__refcnt)) {
1136 u32 score = rt_score(rth);
1138 if (score <= min_score) {
1147 rthp = &rth->dst.rt_next;
1151 /* ip_rt_gc_elasticity used to be average length of chain
1152 * length, when exceeded gc becomes really aggressive.
1154 * The second limit is less certain. At the moment it allows
1155 * only 2 entries per bucket. We will see.
1157 if (chain_length > ip_rt_gc_elasticity) {
1158 *candp = cand->dst.rt_next;
1162 if (chain_length > rt_chain_length_max &&
1163 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1164 struct net *net = dev_net(rt->dst.dev);
1165 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1166 if (!rt_caching(net)) {
1167 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1168 rt->dst.dev->name, num);
1170 rt_emergency_hash_rebuild(net);
1171 spin_unlock_bh(rt_hash_lock_addr(hash));
1173 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1174 ifindex, rt_genid(net));
1179 /* Try to bind route to arp only if it is output
1180 route or unicast forwarding path.
1182 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1183 int err = rt_bind_neighbour(rt);
1185 spin_unlock_bh(rt_hash_lock_addr(hash));
1187 if (err != -ENOBUFS) {
1189 return ERR_PTR(err);
1192 /* Neighbour tables are full and nothing
1193 can be released. Try to shrink route cache,
1194 it is most likely it holds some neighbour records.
1196 if (attempts-- > 0) {
1197 int saved_elasticity = ip_rt_gc_elasticity;
1198 int saved_int = ip_rt_gc_min_interval;
1199 ip_rt_gc_elasticity = 1;
1200 ip_rt_gc_min_interval = 0;
1201 rt_garbage_collect(&ipv4_dst_ops);
1202 ip_rt_gc_min_interval = saved_int;
1203 ip_rt_gc_elasticity = saved_elasticity;
1207 if (net_ratelimit())
1208 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1210 return ERR_PTR(-ENOBUFS);
1214 rt->dst.rt_next = rt_hash_table[hash].chain;
1217 * Since lookup is lockfree, we must make sure
1218 * previous writes to rt are committed to memory
1219 * before making rt visible to other CPUS.
1221 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1223 spin_unlock_bh(rt_hash_lock_addr(hash));
1227 skb_dst_set(skb, &rt->dst);
1231 static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1233 static u32 rt_peer_genid(void)
1235 return atomic_read(&__rt_peer_genid);
1238 void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
1240 struct inet_peer *peer;
1242 peer = inet_getpeer_v4(daddr, create);
1244 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1247 rt->rt_peer_genid = rt_peer_genid();
1251 * Peer allocation may fail only in serious out-of-memory conditions. However
1252 * we still can generate some output.
1253 * Random ID selection looks a bit dangerous because we have no chances to
1254 * select ID being unique in a reasonable period of time.
1255 * But broken packet identifier may be better than no packet at all.
1257 static void ip_select_fb_ident(struct iphdr *iph)
1259 static DEFINE_SPINLOCK(ip_fb_id_lock);
1260 static u32 ip_fallback_id;
1263 spin_lock_bh(&ip_fb_id_lock);
1264 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1265 iph->id = htons(salt & 0xFFFF);
1266 ip_fallback_id = salt;
1267 spin_unlock_bh(&ip_fb_id_lock);
1270 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1272 struct rtable *rt = (struct rtable *) dst;
1275 if (rt->peer == NULL)
1276 rt_bind_peer(rt, rt->rt_dst, 1);
1278 /* If peer is attached to destination, it is never detached,
1279 so that we need not to grab a lock to dereference it.
1282 iph->id = htons(inet_getid(rt->peer, more));
1286 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1287 __builtin_return_address(0));
1289 ip_select_fb_ident(iph);
1291 EXPORT_SYMBOL(__ip_select_ident);
1293 static void rt_del(unsigned hash, struct rtable *rt)
1295 struct rtable __rcu **rthp;
1298 rthp = &rt_hash_table[hash].chain;
1299 spin_lock_bh(rt_hash_lock_addr(hash));
1301 while ((aux = rcu_dereference_protected(*rthp,
1302 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1303 if (aux == rt || rt_is_expired(aux)) {
1304 *rthp = aux->dst.rt_next;
1308 rthp = &aux->dst.rt_next;
1310 spin_unlock_bh(rt_hash_lock_addr(hash));
1313 static void check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1315 struct rtable *rt = (struct rtable *) dst;
1316 __be32 orig_gw = rt->rt_gateway;
1317 struct neighbour *n, *old_n;
1319 dst_confirm(&rt->dst);
1321 rt->rt_gateway = peer->redirect_learned.a4;
1323 n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
1325 rt->rt_gateway = orig_gw;
1328 old_n = xchg(&rt->dst._neighbour, n);
1330 neigh_release(old_n);
1331 if (!(n->nud_state & NUD_VALID)) {
1332 neigh_event_send(n, NULL);
1334 rt->rt_flags |= RTCF_REDIRECTED;
1335 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
1339 /* called in rcu_read_lock() section */
1340 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1341 __be32 saddr, struct net_device *dev)
1344 struct in_device *in_dev = __in_dev_get_rcu(dev);
1345 __be32 skeys[2] = { saddr, 0 };
1346 int ikeys[2] = { dev->ifindex, 0 };
1347 struct inet_peer *peer;
1354 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1355 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1356 ipv4_is_zeronet(new_gw))
1357 goto reject_redirect;
1359 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1360 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1361 goto reject_redirect;
1362 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1363 goto reject_redirect;
1365 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1366 goto reject_redirect;
1369 for (s = 0; s < 2; s++) {
1370 for (i = 0; i < 2; i++) {
1372 struct rtable __rcu **rthp;
1375 hash = rt_hash(daddr, skeys[s], ikeys[i], rt_genid(net));
1377 rthp = &rt_hash_table[hash].chain;
1379 while ((rt = rcu_dereference(*rthp)) != NULL) {
1380 rthp = &rt->dst.rt_next;
1382 if (rt->rt_key_dst != daddr ||
1383 rt->rt_key_src != skeys[s] ||
1384 rt->rt_oif != ikeys[i] ||
1385 rt_is_input_route(rt) ||
1386 rt_is_expired(rt) ||
1387 !net_eq(dev_net(rt->dst.dev), net) ||
1389 rt->dst.dev != dev ||
1390 rt->rt_gateway != old_gw)
1394 rt_bind_peer(rt, rt->rt_dst, 1);
1398 if (peer->redirect_learned.a4 != new_gw ||
1399 peer->redirect_genid != redirect_genid) {
1400 peer->redirect_learned.a4 = new_gw;
1401 peer->redirect_genid = redirect_genid;
1402 atomic_inc(&__rt_peer_genid);
1404 check_peer_redir(&rt->dst, peer);
1412 #ifdef CONFIG_IP_ROUTE_VERBOSE
1413 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1414 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1415 " Advised path = %pI4 -> %pI4\n",
1416 &old_gw, dev->name, &new_gw,
1422 static bool peer_pmtu_expired(struct inet_peer *peer)
1424 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1427 time_after_eq(jiffies, orig) &&
1428 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1431 static bool peer_pmtu_cleaned(struct inet_peer *peer)
1433 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1436 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1439 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1441 struct rtable *rt = (struct rtable *)dst;
1442 struct dst_entry *ret = dst;
1445 if (dst->obsolete > 0) {
1448 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1449 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1451 rt_genid(dev_net(dst->dev)));
1454 } else if (rt->peer && peer_pmtu_expired(rt->peer)) {
1455 dst_metric_set(dst, RTAX_MTU, rt->peer->pmtu_orig);
1463 * 1. The first ip_rt_redirect_number redirects are sent
1464 * with exponential backoff, then we stop sending them at all,
1465 * assuming that the host ignores our redirects.
1466 * 2. If we did not see packets requiring redirects
1467 * during ip_rt_redirect_silence, we assume that the host
1468 * forgot redirected route and start to send redirects again.
1470 * This algorithm is much cheaper and more intelligent than dumb load limiting
1473 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1474 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1477 void ip_rt_send_redirect(struct sk_buff *skb)
1479 struct rtable *rt = skb_rtable(skb);
1480 struct in_device *in_dev;
1481 struct inet_peer *peer;
1485 in_dev = __in_dev_get_rcu(rt->dst.dev);
1486 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1490 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1494 rt_bind_peer(rt, rt->rt_dst, 1);
1497 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1501 /* No redirected packets during ip_rt_redirect_silence;
1502 * reset the algorithm.
1504 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1505 peer->rate_tokens = 0;
1507 /* Too many ignored redirects; do not send anything
1508 * set dst.rate_last to the last seen redirected packet.
1510 if (peer->rate_tokens >= ip_rt_redirect_number) {
1511 peer->rate_last = jiffies;
1515 /* Check for load limit; set rate_last to the latest sent
1518 if (peer->rate_tokens == 0 ||
1521 (ip_rt_redirect_load << peer->rate_tokens)))) {
1522 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1523 peer->rate_last = jiffies;
1524 ++peer->rate_tokens;
1525 #ifdef CONFIG_IP_ROUTE_VERBOSE
1527 peer->rate_tokens == ip_rt_redirect_number &&
1529 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1530 &ip_hdr(skb)->saddr, rt->rt_iif,
1531 &rt->rt_dst, &rt->rt_gateway);
1536 static int ip_error(struct sk_buff *skb)
1538 struct rtable *rt = skb_rtable(skb);
1539 struct inet_peer *peer;
1544 switch (rt->dst.error) {
1549 code = ICMP_HOST_UNREACH;
1552 code = ICMP_NET_UNREACH;
1553 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1554 IPSTATS_MIB_INNOROUTES);
1557 code = ICMP_PKT_FILTERED;
1562 rt_bind_peer(rt, rt->rt_dst, 1);
1568 peer->rate_tokens += now - peer->rate_last;
1569 if (peer->rate_tokens > ip_rt_error_burst)
1570 peer->rate_tokens = ip_rt_error_burst;
1571 peer->rate_last = now;
1572 if (peer->rate_tokens >= ip_rt_error_cost)
1573 peer->rate_tokens -= ip_rt_error_cost;
1578 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1580 out: kfree_skb(skb);
1585 * The last two values are not from the RFC but
1586 * are needed for AMPRnet AX.25 paths.
1589 static const unsigned short mtu_plateau[] =
1590 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1592 static inline unsigned short guess_mtu(unsigned short old_mtu)
1596 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1597 if (old_mtu > mtu_plateau[i])
1598 return mtu_plateau[i];
1602 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
1603 unsigned short new_mtu,
1604 struct net_device *dev)
1606 unsigned short old_mtu = ntohs(iph->tot_len);
1607 unsigned short est_mtu = 0;
1608 struct inet_peer *peer;
1610 peer = inet_getpeer_v4(iph->daddr, 1);
1612 unsigned short mtu = new_mtu;
1614 if (new_mtu < 68 || new_mtu >= old_mtu) {
1615 /* BSD 4.2 derived systems incorrectly adjust
1616 * tot_len by the IP header length, and report
1617 * a zero MTU in the ICMP message.
1620 old_mtu >= 68 + (iph->ihl << 2))
1621 old_mtu -= iph->ihl << 2;
1622 mtu = guess_mtu(old_mtu);
1625 if (mtu < ip_rt_min_pmtu)
1626 mtu = ip_rt_min_pmtu;
1627 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1628 unsigned long pmtu_expires;
1630 pmtu_expires = jiffies + ip_rt_mtu_expires;
1635 peer->pmtu_learned = mtu;
1636 peer->pmtu_expires = pmtu_expires;
1637 atomic_inc(&__rt_peer_genid);
1642 return est_mtu ? : new_mtu;
1645 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1647 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires);
1651 if (time_before(jiffies, expires)) {
1652 u32 orig_dst_mtu = dst_mtu(dst);
1653 if (peer->pmtu_learned < orig_dst_mtu) {
1654 if (!peer->pmtu_orig)
1655 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1656 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1658 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1659 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1662 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1664 struct rtable *rt = (struct rtable *) dst;
1665 struct inet_peer *peer;
1670 rt_bind_peer(rt, rt->rt_dst, 1);
1673 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires);
1675 if (mtu < ip_rt_min_pmtu)
1676 mtu = ip_rt_min_pmtu;
1677 if (!pmtu_expires || mtu < peer->pmtu_learned) {
1679 pmtu_expires = jiffies + ip_rt_mtu_expires;
1683 peer->pmtu_learned = mtu;
1684 peer->pmtu_expires = pmtu_expires;
1686 atomic_inc(&__rt_peer_genid);
1687 rt->rt_peer_genid = rt_peer_genid();
1689 check_peer_pmtu(dst, peer);
1694 static void ipv4_validate_peer(struct rtable *rt)
1696 if (rt->rt_peer_genid != rt_peer_genid()) {
1697 struct inet_peer *peer;
1700 rt_bind_peer(rt, rt->rt_dst, 0);
1704 check_peer_pmtu(&rt->dst, peer);
1706 if (peer->redirect_genid != redirect_genid)
1707 peer->redirect_learned.a4 = 0;
1708 if (peer->redirect_learned.a4 &&
1709 peer->redirect_learned.a4 != rt->rt_gateway)
1710 check_peer_redir(&rt->dst, peer);
1713 rt->rt_peer_genid = rt_peer_genid();
1717 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1719 struct rtable *rt = (struct rtable *) dst;
1721 if (rt_is_expired(rt))
1723 ipv4_validate_peer(rt);
1727 static void ipv4_dst_destroy(struct dst_entry *dst)
1729 struct rtable *rt = (struct rtable *) dst;
1730 struct inet_peer *peer = rt->peer;
1733 fib_info_put(rt->fi);
1743 static void ipv4_link_failure(struct sk_buff *skb)
1747 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1749 rt = skb_rtable(skb);
1750 if (rt && rt->peer && peer_pmtu_cleaned(rt->peer))
1751 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1754 static int ip_rt_bug(struct sk_buff *skb)
1756 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1757 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1758 skb->dev ? skb->dev->name : "?");
1765 We do not cache source address of outgoing interface,
1766 because it is used only by IP RR, TS and SRR options,
1767 so that it out of fast path.
1769 BTW remember: "addr" is allowed to be not aligned
1773 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1777 if (rt_is_output_route(rt))
1778 src = ip_hdr(skb)->saddr;
1780 struct fib_result res;
1786 memset(&fl4, 0, sizeof(fl4));
1787 fl4.daddr = iph->daddr;
1788 fl4.saddr = iph->saddr;
1789 fl4.flowi4_tos = RT_TOS(iph->tos);
1790 fl4.flowi4_oif = rt->dst.dev->ifindex;
1791 fl4.flowi4_iif = skb->dev->ifindex;
1792 fl4.flowi4_mark = skb->mark;
1795 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1796 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1798 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1802 memcpy(addr, &src, 4);
1805 #ifdef CONFIG_IP_ROUTE_CLASSID
1806 static void set_class_tag(struct rtable *rt, u32 tag)
1808 if (!(rt->dst.tclassid & 0xFFFF))
1809 rt->dst.tclassid |= tag & 0xFFFF;
1810 if (!(rt->dst.tclassid & 0xFFFF0000))
1811 rt->dst.tclassid |= tag & 0xFFFF0000;
1815 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1817 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1820 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1822 if (advmss > 65535 - 40)
1823 advmss = 65535 - 40;
1828 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1830 const struct rtable *rt = (const struct rtable *) dst;
1831 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
1833 if (mtu && rt_is_output_route(rt))
1836 mtu = dst->dev->mtu;
1838 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1840 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1844 if (mtu > IP_MAX_MTU)
1850 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1851 struct fib_info *fi)
1853 struct inet_peer *peer;
1856 /* If a peer entry exists for this destination, we must hook
1857 * it up in order to get at cached metrics.
1859 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1862 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1864 rt->rt_peer_genid = rt_peer_genid();
1865 if (inet_metrics_new(peer))
1866 memcpy(peer->metrics, fi->fib_metrics,
1867 sizeof(u32) * RTAX_MAX);
1868 dst_init_metrics(&rt->dst, peer->metrics, false);
1870 check_peer_pmtu(&rt->dst, peer);
1871 if (peer->redirect_genid != redirect_genid)
1872 peer->redirect_learned.a4 = 0;
1873 if (peer->redirect_learned.a4 &&
1874 peer->redirect_learned.a4 != rt->rt_gateway) {
1875 rt->rt_gateway = peer->redirect_learned.a4;
1876 rt->rt_flags |= RTCF_REDIRECTED;
1879 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1881 atomic_inc(&fi->fib_clntref);
1883 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1887 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1888 const struct fib_result *res,
1889 struct fib_info *fi, u16 type, u32 itag)
1891 struct dst_entry *dst = &rt->dst;
1894 if (FIB_RES_GW(*res) &&
1895 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1896 rt->rt_gateway = FIB_RES_GW(*res);
1897 rt_init_metrics(rt, fl4, fi);
1898 #ifdef CONFIG_IP_ROUTE_CLASSID
1899 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1903 if (dst_mtu(dst) > IP_MAX_MTU)
1904 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1905 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1906 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1908 #ifdef CONFIG_IP_ROUTE_CLASSID
1909 #ifdef CONFIG_IP_MULTIPLE_TABLES
1910 set_class_tag(rt, fib_rules_tclass(res));
1912 set_class_tag(rt, itag);
1916 static struct rtable *rt_dst_alloc(struct net_device *dev,
1917 bool nopolicy, bool noxfrm)
1919 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
1921 (nopolicy ? DST_NOPOLICY : 0) |
1922 (noxfrm ? DST_NOXFRM : 0));
1925 /* called in rcu_read_lock() section */
1926 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1927 u8 tos, struct net_device *dev, int our)
1932 struct in_device *in_dev = __in_dev_get_rcu(dev);
1936 /* Primary sanity checks. */
1941 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1942 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1945 if (ipv4_is_zeronet(saddr)) {
1946 if (!ipv4_is_local_multicast(daddr))
1948 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1950 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
1955 rth = rt_dst_alloc(init_net.loopback_dev,
1956 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1960 #ifdef CONFIG_IP_ROUTE_CLASSID
1961 rth->dst.tclassid = itag;
1963 rth->dst.output = ip_rt_bug;
1965 rth->rt_key_dst = daddr;
1966 rth->rt_key_src = saddr;
1967 rth->rt_genid = rt_genid(dev_net(dev));
1968 rth->rt_flags = RTCF_MULTICAST;
1969 rth->rt_type = RTN_MULTICAST;
1970 rth->rt_key_tos = tos;
1971 rth->rt_dst = daddr;
1972 rth->rt_src = saddr;
1973 rth->rt_route_iif = dev->ifindex;
1974 rth->rt_iif = dev->ifindex;
1976 rth->rt_mark = skb->mark;
1977 rth->rt_gateway = daddr;
1978 rth->rt_spec_dst= spec_dst;
1979 rth->rt_peer_genid = 0;
1983 rth->dst.input= ip_local_deliver;
1984 rth->rt_flags |= RTCF_LOCAL;
1987 #ifdef CONFIG_IP_MROUTE
1988 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1989 rth->dst.input = ip_mr_input;
1991 RT_CACHE_STAT_INC(in_slow_mc);
1993 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1994 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
1995 return IS_ERR(rth) ? PTR_ERR(rth) : 0;
2006 static void ip_handle_martian_source(struct net_device *dev,
2007 struct in_device *in_dev,
2008 struct sk_buff *skb,
2012 RT_CACHE_STAT_INC(in_martian_src);
2013 #ifdef CONFIG_IP_ROUTE_VERBOSE
2014 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
2016 * RFC1812 recommendation, if source is martian,
2017 * the only hint is MAC header.
2019 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
2020 &daddr, &saddr, dev->name);
2021 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
2023 const unsigned char *p = skb_mac_header(skb);
2024 printk(KERN_WARNING "ll header: ");
2025 for (i = 0; i < dev->hard_header_len; i++, p++) {
2027 if (i < (dev->hard_header_len - 1))
2036 /* called in rcu_read_lock() section */
2037 static int __mkroute_input(struct sk_buff *skb,
2038 const struct fib_result *res,
2039 struct in_device *in_dev,
2040 __be32 daddr, __be32 saddr, u32 tos,
2041 struct rtable **result)
2045 struct in_device *out_dev;
2046 unsigned int flags = 0;
2050 /* get a working reference to the output device */
2051 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
2052 if (out_dev == NULL) {
2053 if (net_ratelimit())
2054 printk(KERN_CRIT "Bug in ip_route_input" \
2055 "_slow(). Please, report\n");
2060 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
2061 in_dev->dev, &spec_dst, &itag);
2063 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2070 flags |= RTCF_DIRECTSRC;
2072 if (out_dev == in_dev && err &&
2073 (IN_DEV_SHARED_MEDIA(out_dev) ||
2074 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2075 flags |= RTCF_DOREDIRECT;
2077 if (skb->protocol != htons(ETH_P_IP)) {
2078 /* Not IP (i.e. ARP). Do not create route, if it is
2079 * invalid for proxy arp. DNAT routes are always valid.
2081 * Proxy arp feature have been extended to allow, ARP
2082 * replies back to the same interface, to support
2083 * Private VLAN switch technologies. See arp.c.
2085 if (out_dev == in_dev &&
2086 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2092 rth = rt_dst_alloc(out_dev->dev,
2093 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2094 IN_DEV_CONF_GET(out_dev, NOXFRM));
2100 rth->rt_key_dst = daddr;
2101 rth->rt_key_src = saddr;
2102 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2103 rth->rt_flags = flags;
2104 rth->rt_type = res->type;
2105 rth->rt_key_tos = tos;
2106 rth->rt_dst = daddr;
2107 rth->rt_src = saddr;
2108 rth->rt_route_iif = in_dev->dev->ifindex;
2109 rth->rt_iif = in_dev->dev->ifindex;
2111 rth->rt_mark = skb->mark;
2112 rth->rt_gateway = daddr;
2113 rth->rt_spec_dst= spec_dst;
2114 rth->rt_peer_genid = 0;
2118 rth->dst.input = ip_forward;
2119 rth->dst.output = ip_output;
2121 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2129 static int ip_mkroute_input(struct sk_buff *skb,
2130 struct fib_result *res,
2131 const struct flowi4 *fl4,
2132 struct in_device *in_dev,
2133 __be32 daddr, __be32 saddr, u32 tos)
2135 struct rtable* rth = NULL;
2139 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2140 if (res->fi && res->fi->fib_nhs > 1)
2141 fib_select_multipath(res);
2144 /* create a routing cache entry */
2145 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2149 /* put it into the cache */
2150 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2151 rt_genid(dev_net(rth->dst.dev)));
2152 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2154 return PTR_ERR(rth);
2159 * NOTE. We drop all the packets that has local source
2160 * addresses, because every properly looped back packet
2161 * must have correct destination already attached by output routine.
2163 * Such approach solves two big problems:
2164 * 1. Not simplex devices are handled properly.
2165 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2166 * called with rcu_read_lock()
2169 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2170 u8 tos, struct net_device *dev)
2172 struct fib_result res;
2173 struct in_device *in_dev = __in_dev_get_rcu(dev);
2177 struct rtable * rth;
2181 struct net * net = dev_net(dev);
2183 /* IP on this device is disabled. */
2188 /* Check for the most weird martians, which can be not detected
2192 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2193 ipv4_is_loopback(saddr))
2194 goto martian_source;
2196 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2199 /* Accept zero addresses only to limited broadcast;
2200 * I even do not know to fix it or not. Waiting for complains :-)
2202 if (ipv4_is_zeronet(saddr))
2203 goto martian_source;
2205 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2206 goto martian_destination;
2209 * Now we are ready to route packet.
2212 fl4.flowi4_iif = dev->ifindex;
2213 fl4.flowi4_mark = skb->mark;
2214 fl4.flowi4_tos = tos;
2215 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2218 err = fib_lookup(net, &fl4, &res);
2220 if (!IN_DEV_FORWARD(in_dev))
2225 RT_CACHE_STAT_INC(in_slow_tot);
2227 if (res.type == RTN_BROADCAST)
2230 if (res.type == RTN_LOCAL) {
2231 err = fib_validate_source(skb, saddr, daddr, tos,
2232 net->loopback_dev->ifindex,
2233 dev, &spec_dst, &itag);
2235 goto martian_source_keep_err;
2237 flags |= RTCF_DIRECTSRC;
2242 if (!IN_DEV_FORWARD(in_dev))
2244 if (res.type != RTN_UNICAST)
2245 goto martian_destination;
2247 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2251 if (skb->protocol != htons(ETH_P_IP))
2254 if (ipv4_is_zeronet(saddr))
2255 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2257 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2260 goto martian_source_keep_err;
2262 flags |= RTCF_DIRECTSRC;
2264 flags |= RTCF_BROADCAST;
2265 res.type = RTN_BROADCAST;
2266 RT_CACHE_STAT_INC(in_brd);
2269 rth = rt_dst_alloc(net->loopback_dev,
2270 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2274 rth->dst.input= ip_local_deliver;
2275 rth->dst.output= ip_rt_bug;
2276 #ifdef CONFIG_IP_ROUTE_CLASSID
2277 rth->dst.tclassid = itag;
2280 rth->rt_key_dst = daddr;
2281 rth->rt_key_src = saddr;
2282 rth->rt_genid = rt_genid(net);
2283 rth->rt_flags = flags|RTCF_LOCAL;
2284 rth->rt_type = res.type;
2285 rth->rt_key_tos = tos;
2286 rth->rt_dst = daddr;
2287 rth->rt_src = saddr;
2288 #ifdef CONFIG_IP_ROUTE_CLASSID
2289 rth->dst.tclassid = itag;
2291 rth->rt_route_iif = dev->ifindex;
2292 rth->rt_iif = dev->ifindex;
2294 rth->rt_mark = skb->mark;
2295 rth->rt_gateway = daddr;
2296 rth->rt_spec_dst= spec_dst;
2297 rth->rt_peer_genid = 0;
2300 if (res.type == RTN_UNREACHABLE) {
2301 rth->dst.input= ip_error;
2302 rth->dst.error= -err;
2303 rth->rt_flags &= ~RTCF_LOCAL;
2305 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2306 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2313 RT_CACHE_STAT_INC(in_no_route);
2314 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2315 res.type = RTN_UNREACHABLE;
2321 * Do not cache martian addresses: they should be logged (RFC1812)
2323 martian_destination:
2324 RT_CACHE_STAT_INC(in_martian_dst);
2325 #ifdef CONFIG_IP_ROUTE_VERBOSE
2326 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2327 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2328 &daddr, &saddr, dev->name);
2332 err = -EHOSTUNREACH;
2345 martian_source_keep_err:
2346 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2350 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2351 u8 tos, struct net_device *dev, bool noref)
2353 struct rtable * rth;
2355 int iif = dev->ifindex;
2363 if (!rt_caching(net))
2366 tos &= IPTOS_RT_MASK;
2367 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2369 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2370 rth = rcu_dereference(rth->dst.rt_next)) {
2371 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2372 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2373 (rth->rt_route_iif ^ iif) |
2374 (rth->rt_key_tos ^ tos)) == 0 &&
2375 rth->rt_mark == skb->mark &&
2376 net_eq(dev_net(rth->dst.dev), net) &&
2377 !rt_is_expired(rth)) {
2378 ipv4_validate_peer(rth);
2380 dst_use_noref(&rth->dst, jiffies);
2381 skb_dst_set_noref(skb, &rth->dst);
2383 dst_use(&rth->dst, jiffies);
2384 skb_dst_set(skb, &rth->dst);
2386 RT_CACHE_STAT_INC(in_hit);
2390 RT_CACHE_STAT_INC(in_hlist_search);
2394 /* Multicast recognition logic is moved from route cache to here.
2395 The problem was that too many Ethernet cards have broken/missing
2396 hardware multicast filters :-( As result the host on multicasting
2397 network acquires a lot of useless route cache entries, sort of
2398 SDR messages from all the world. Now we try to get rid of them.
2399 Really, provided software IP multicast filter is organized
2400 reasonably (at least, hashed), it does not result in a slowdown
2401 comparing with route cache reject entries.
2402 Note, that multicast routers are not affected, because
2403 route cache entry is created eventually.
2405 if (ipv4_is_multicast(daddr)) {
2406 struct in_device *in_dev = __in_dev_get_rcu(dev);
2409 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2410 ip_hdr(skb)->protocol);
2412 #ifdef CONFIG_IP_MROUTE
2414 (!ipv4_is_local_multicast(daddr) &&
2415 IN_DEV_MFORWARD(in_dev))
2418 int res = ip_route_input_mc(skb, daddr, saddr,
2427 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2431 EXPORT_SYMBOL(ip_route_input_common);
2433 /* called with rcu_read_lock() */
2434 static struct rtable *__mkroute_output(const struct fib_result *res,
2435 const struct flowi4 *fl4,
2436 __be32 orig_daddr, __be32 orig_saddr,
2437 int orig_oif, __u8 orig_rtos,
2438 struct net_device *dev_out,
2441 struct fib_info *fi = res->fi;
2442 struct in_device *in_dev;
2443 u16 type = res->type;
2446 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2447 return ERR_PTR(-EINVAL);
2449 if (ipv4_is_lbcast(fl4->daddr))
2450 type = RTN_BROADCAST;
2451 else if (ipv4_is_multicast(fl4->daddr))
2452 type = RTN_MULTICAST;
2453 else if (ipv4_is_zeronet(fl4->daddr))
2454 return ERR_PTR(-EINVAL);
2456 if (dev_out->flags & IFF_LOOPBACK)
2457 flags |= RTCF_LOCAL;
2459 in_dev = __in_dev_get_rcu(dev_out);
2461 return ERR_PTR(-EINVAL);
2463 if (type == RTN_BROADCAST) {
2464 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2466 } else if (type == RTN_MULTICAST) {
2467 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2468 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2470 flags &= ~RTCF_LOCAL;
2471 /* If multicast route do not exist use
2472 * default one, but do not gateway in this case.
2475 if (fi && res->prefixlen < 4)
2479 rth = rt_dst_alloc(dev_out,
2480 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2481 IN_DEV_CONF_GET(in_dev, NOXFRM));
2483 return ERR_PTR(-ENOBUFS);
2485 rth->dst.output = ip_output;
2487 rth->rt_key_dst = orig_daddr;
2488 rth->rt_key_src = orig_saddr;
2489 rth->rt_genid = rt_genid(dev_net(dev_out));
2490 rth->rt_flags = flags;
2491 rth->rt_type = type;
2492 rth->rt_key_tos = orig_rtos;
2493 rth->rt_dst = fl4->daddr;
2494 rth->rt_src = fl4->saddr;
2495 rth->rt_route_iif = 0;
2496 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2497 rth->rt_oif = orig_oif;
2498 rth->rt_mark = fl4->flowi4_mark;
2499 rth->rt_gateway = fl4->daddr;
2500 rth->rt_spec_dst= fl4->saddr;
2501 rth->rt_peer_genid = 0;
2505 RT_CACHE_STAT_INC(out_slow_tot);
2507 if (flags & RTCF_LOCAL) {
2508 rth->dst.input = ip_local_deliver;
2509 rth->rt_spec_dst = fl4->daddr;
2511 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2512 rth->rt_spec_dst = fl4->saddr;
2513 if (flags & RTCF_LOCAL &&
2514 !(dev_out->flags & IFF_LOOPBACK)) {
2515 rth->dst.output = ip_mc_output;
2516 RT_CACHE_STAT_INC(out_slow_mc);
2518 #ifdef CONFIG_IP_MROUTE
2519 if (type == RTN_MULTICAST) {
2520 if (IN_DEV_MFORWARD(in_dev) &&
2521 !ipv4_is_local_multicast(fl4->daddr)) {
2522 rth->dst.input = ip_mr_input;
2523 rth->dst.output = ip_mc_output;
2529 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2535 * Major route resolver routine.
2536 * called with rcu_read_lock();
2539 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2541 struct net_device *dev_out = NULL;
2542 __u8 tos = RT_FL_TOS(fl4);
2543 unsigned int flags = 0;
2544 struct fib_result res;
2551 #ifdef CONFIG_IP_MULTIPLE_TABLES
2555 orig_daddr = fl4->daddr;
2556 orig_saddr = fl4->saddr;
2557 orig_oif = fl4->flowi4_oif;
2559 fl4->flowi4_iif = net->loopback_dev->ifindex;
2560 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2561 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2562 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2566 rth = ERR_PTR(-EINVAL);
2567 if (ipv4_is_multicast(fl4->saddr) ||
2568 ipv4_is_lbcast(fl4->saddr) ||
2569 ipv4_is_zeronet(fl4->saddr))
2572 /* I removed check for oif == dev_out->oif here.
2573 It was wrong for two reasons:
2574 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2575 is assigned to multiple interfaces.
2576 2. Moreover, we are allowed to send packets with saddr
2577 of another iface. --ANK
2580 if (fl4->flowi4_oif == 0 &&
2581 (ipv4_is_multicast(fl4->daddr) ||
2582 ipv4_is_lbcast(fl4->daddr))) {
2583 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2584 dev_out = __ip_dev_find(net, fl4->saddr, false);
2585 if (dev_out == NULL)
2588 /* Special hack: user can direct multicasts
2589 and limited broadcast via necessary interface
2590 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2591 This hack is not just for fun, it allows
2592 vic,vat and friends to work.
2593 They bind socket to loopback, set ttl to zero
2594 and expect that it will work.
2595 From the viewpoint of routing cache they are broken,
2596 because we are not allowed to build multicast path
2597 with loopback source addr (look, routing cache
2598 cannot know, that ttl is zero, so that packet
2599 will not leave this host and route is valid).
2600 Luckily, this hack is good workaround.
2603 fl4->flowi4_oif = dev_out->ifindex;
2607 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2608 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2609 if (!__ip_dev_find(net, fl4->saddr, false))
2615 if (fl4->flowi4_oif) {
2616 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2617 rth = ERR_PTR(-ENODEV);
2618 if (dev_out == NULL)
2621 /* RACE: Check return value of inet_select_addr instead. */
2622 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2623 rth = ERR_PTR(-ENETUNREACH);
2626 if (ipv4_is_local_multicast(fl4->daddr) ||
2627 ipv4_is_lbcast(fl4->daddr)) {
2629 fl4->saddr = inet_select_addr(dev_out, 0,
2634 if (ipv4_is_multicast(fl4->daddr))
2635 fl4->saddr = inet_select_addr(dev_out, 0,
2637 else if (!fl4->daddr)
2638 fl4->saddr = inet_select_addr(dev_out, 0,
2644 fl4->daddr = fl4->saddr;
2646 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2647 dev_out = net->loopback_dev;
2648 fl4->flowi4_oif = net->loopback_dev->ifindex;
2649 res.type = RTN_LOCAL;
2650 flags |= RTCF_LOCAL;
2654 if (fib_lookup(net, fl4, &res)) {
2656 if (fl4->flowi4_oif) {
2657 /* Apparently, routing tables are wrong. Assume,
2658 that the destination is on link.
2661 Because we are allowed to send to iface
2662 even if it has NO routes and NO assigned
2663 addresses. When oif is specified, routing
2664 tables are looked up with only one purpose:
2665 to catch if destination is gatewayed, rather than
2666 direct. Moreover, if MSG_DONTROUTE is set,
2667 we send packet, ignoring both routing tables
2668 and ifaddr state. --ANK
2671 We could make it even if oif is unknown,
2672 likely IPv6, but we do not.
2675 if (fl4->saddr == 0)
2676 fl4->saddr = inet_select_addr(dev_out, 0,
2678 res.type = RTN_UNICAST;
2681 rth = ERR_PTR(-ENETUNREACH);
2685 if (res.type == RTN_LOCAL) {
2687 if (res.fi->fib_prefsrc)
2688 fl4->saddr = res.fi->fib_prefsrc;
2690 fl4->saddr = fl4->daddr;
2692 dev_out = net->loopback_dev;
2693 fl4->flowi4_oif = dev_out->ifindex;
2695 flags |= RTCF_LOCAL;
2699 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2700 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2701 fib_select_multipath(&res);
2704 if (!res.prefixlen &&
2705 res.table->tb_num_default > 1 &&
2706 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2707 fib_select_default(&res);
2710 fl4->saddr = FIB_RES_PREFSRC(net, res);
2712 dev_out = FIB_RES_DEV(res);
2713 fl4->flowi4_oif = dev_out->ifindex;
2717 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2718 tos, dev_out, flags);
2722 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2723 rt_genid(dev_net(dev_out)));
2724 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2732 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2737 if (!rt_caching(net))
2740 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2743 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2744 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2745 if (rth->rt_key_dst == flp4->daddr &&
2746 rth->rt_key_src == flp4->saddr &&
2747 rt_is_output_route(rth) &&
2748 rth->rt_oif == flp4->flowi4_oif &&
2749 rth->rt_mark == flp4->flowi4_mark &&
2750 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2751 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2752 net_eq(dev_net(rth->dst.dev), net) &&
2753 !rt_is_expired(rth)) {
2754 ipv4_validate_peer(rth);
2755 dst_use(&rth->dst, jiffies);
2756 RT_CACHE_STAT_INC(out_hit);
2757 rcu_read_unlock_bh();
2759 flp4->saddr = rth->rt_src;
2761 flp4->daddr = rth->rt_dst;
2764 RT_CACHE_STAT_INC(out_hlist_search);
2766 rcu_read_unlock_bh();
2769 return ip_route_output_slow(net, flp4);
2771 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2773 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2778 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2780 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2782 return mtu ? : dst->dev->mtu;
2785 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2789 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2795 static struct dst_ops ipv4_dst_blackhole_ops = {
2797 .protocol = cpu_to_be16(ETH_P_IP),
2798 .destroy = ipv4_dst_destroy,
2799 .check = ipv4_blackhole_dst_check,
2800 .mtu = ipv4_blackhole_mtu,
2801 .default_advmss = ipv4_default_advmss,
2802 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2803 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2804 .neigh_lookup = ipv4_neigh_lookup,
2807 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2809 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2810 struct rtable *ort = (struct rtable *) dst_orig;
2813 struct dst_entry *new = &rt->dst;
2816 new->input = dst_discard;
2817 new->output = dst_discard;
2818 dst_copy_metrics(new, &ort->dst);
2820 new->dev = ort->dst.dev;
2824 rt->rt_key_dst = ort->rt_key_dst;
2825 rt->rt_key_src = ort->rt_key_src;
2826 rt->rt_key_tos = ort->rt_key_tos;
2827 rt->rt_route_iif = ort->rt_route_iif;
2828 rt->rt_iif = ort->rt_iif;
2829 rt->rt_oif = ort->rt_oif;
2830 rt->rt_mark = ort->rt_mark;
2832 rt->rt_genid = rt_genid(net);
2833 rt->rt_flags = ort->rt_flags;
2834 rt->rt_type = ort->rt_type;
2835 rt->rt_dst = ort->rt_dst;
2836 rt->rt_src = ort->rt_src;
2837 rt->rt_gateway = ort->rt_gateway;
2838 rt->rt_spec_dst = ort->rt_spec_dst;
2839 rt->peer = ort->peer;
2841 atomic_inc(&rt->peer->refcnt);
2844 atomic_inc(&rt->fi->fib_clntref);
2849 dst_release(dst_orig);
2851 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2854 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2857 struct rtable *rt = __ip_route_output_key(net, flp4);
2862 if (flp4->flowi4_proto)
2863 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2864 flowi4_to_flowi(flp4),
2869 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2871 static int rt_fill_info(struct net *net,
2872 struct sk_buff *skb, u32 pid, u32 seq, int event,
2873 int nowait, unsigned int flags)
2875 struct rtable *rt = skb_rtable(skb);
2877 struct nlmsghdr *nlh;
2878 unsigned long expires = 0;
2879 const struct inet_peer *peer = rt->peer;
2880 u32 id = 0, ts = 0, tsage = 0, error;
2882 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2886 r = nlmsg_data(nlh);
2887 r->rtm_family = AF_INET;
2888 r->rtm_dst_len = 32;
2890 r->rtm_tos = rt->rt_key_tos;
2891 r->rtm_table = RT_TABLE_MAIN;
2892 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2893 r->rtm_type = rt->rt_type;
2894 r->rtm_scope = RT_SCOPE_UNIVERSE;
2895 r->rtm_protocol = RTPROT_UNSPEC;
2896 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2897 if (rt->rt_flags & RTCF_NOTIFY)
2898 r->rtm_flags |= RTM_F_NOTIFY;
2900 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2902 if (rt->rt_key_src) {
2903 r->rtm_src_len = 32;
2904 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2907 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2908 #ifdef CONFIG_IP_ROUTE_CLASSID
2909 if (rt->dst.tclassid)
2910 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2912 if (rt_is_input_route(rt))
2913 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2914 else if (rt->rt_src != rt->rt_key_src)
2915 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2917 if (rt->rt_dst != rt->rt_gateway)
2918 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2920 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2921 goto nla_put_failure;
2924 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
2926 error = rt->dst.error;
2928 inet_peer_refcheck(rt->peer);
2929 id = atomic_read(&peer->ip_id_count) & 0xffff;
2930 if (peer->tcp_ts_stamp) {
2932 tsage = get_seconds() - peer->tcp_ts_stamp;
2934 expires = ACCESS_ONCE(peer->pmtu_expires);
2936 if (time_before(jiffies, expires))
2943 if (rt_is_input_route(rt)) {
2944 #ifdef CONFIG_IP_MROUTE
2945 __be32 dst = rt->rt_dst;
2947 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2948 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2949 int err = ipmr_get_route(net, skb,
2950 rt->rt_src, rt->rt_dst,
2956 goto nla_put_failure;
2958 if (err == -EMSGSIZE)
2959 goto nla_put_failure;
2965 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
2968 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2969 expires, error) < 0)
2970 goto nla_put_failure;
2972 return nlmsg_end(skb, nlh);
2975 nlmsg_cancel(skb, nlh);
2979 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2981 struct net *net = sock_net(in_skb->sk);
2983 struct nlattr *tb[RTA_MAX+1];
2984 struct rtable *rt = NULL;
2990 struct sk_buff *skb;
2992 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2996 rtm = nlmsg_data(nlh);
2998 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3004 /* Reserve room for dummy headers, this skb can pass
3005 through good chunk of routing engine.
3007 skb_reset_mac_header(skb);
3008 skb_reset_network_header(skb);
3010 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
3011 ip_hdr(skb)->protocol = IPPROTO_ICMP;
3012 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
3014 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
3015 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
3016 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
3017 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
3020 struct net_device *dev;
3022 dev = __dev_get_by_index(net, iif);
3028 skb->protocol = htons(ETH_P_IP);
3032 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
3035 rt = skb_rtable(skb);
3036 if (err == 0 && rt->dst.error)
3037 err = -rt->dst.error;
3039 struct flowi4 fl4 = {
3042 .flowi4_tos = rtm->rtm_tos,
3043 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
3044 .flowi4_mark = mark,
3046 rt = ip_route_output_key(net, &fl4);
3056 skb_dst_set(skb, &rt->dst);
3057 if (rtm->rtm_flags & RTM_F_NOTIFY)
3058 rt->rt_flags |= RTCF_NOTIFY;
3060 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3061 RTM_NEWROUTE, 0, 0);
3065 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3074 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3081 net = sock_net(skb->sk);
3086 s_idx = idx = cb->args[1];
3087 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3088 if (!rt_hash_table[h].chain)
3091 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3092 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3093 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3095 if (rt_is_expired(rt))
3097 skb_dst_set_noref(skb, &rt->dst);
3098 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3099 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3100 1, NLM_F_MULTI) <= 0) {
3102 rcu_read_unlock_bh();
3107 rcu_read_unlock_bh();
3116 void ip_rt_multicast_event(struct in_device *in_dev)
3118 rt_cache_flush(dev_net(in_dev->dev), 0);
3121 #ifdef CONFIG_SYSCTL
3122 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3123 void __user *buffer,
3124 size_t *lenp, loff_t *ppos)
3131 memcpy(&ctl, __ctl, sizeof(ctl));
3132 ctl.data = &flush_delay;
3133 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3135 net = (struct net *)__ctl->extra1;
3136 rt_cache_flush(net, flush_delay);
3143 static ctl_table ipv4_route_table[] = {
3145 .procname = "gc_thresh",
3146 .data = &ipv4_dst_ops.gc_thresh,
3147 .maxlen = sizeof(int),
3149 .proc_handler = proc_dointvec,
3152 .procname = "max_size",
3153 .data = &ip_rt_max_size,
3154 .maxlen = sizeof(int),
3156 .proc_handler = proc_dointvec,
3159 /* Deprecated. Use gc_min_interval_ms */
3161 .procname = "gc_min_interval",
3162 .data = &ip_rt_gc_min_interval,
3163 .maxlen = sizeof(int),
3165 .proc_handler = proc_dointvec_jiffies,
3168 .procname = "gc_min_interval_ms",
3169 .data = &ip_rt_gc_min_interval,
3170 .maxlen = sizeof(int),
3172 .proc_handler = proc_dointvec_ms_jiffies,
3175 .procname = "gc_timeout",
3176 .data = &ip_rt_gc_timeout,
3177 .maxlen = sizeof(int),
3179 .proc_handler = proc_dointvec_jiffies,
3182 .procname = "redirect_load",
3183 .data = &ip_rt_redirect_load,
3184 .maxlen = sizeof(int),
3186 .proc_handler = proc_dointvec,
3189 .procname = "redirect_number",
3190 .data = &ip_rt_redirect_number,
3191 .maxlen = sizeof(int),
3193 .proc_handler = proc_dointvec,
3196 .procname = "redirect_silence",
3197 .data = &ip_rt_redirect_silence,
3198 .maxlen = sizeof(int),
3200 .proc_handler = proc_dointvec,
3203 .procname = "error_cost",
3204 .data = &ip_rt_error_cost,
3205 .maxlen = sizeof(int),
3207 .proc_handler = proc_dointvec,
3210 .procname = "error_burst",
3211 .data = &ip_rt_error_burst,
3212 .maxlen = sizeof(int),
3214 .proc_handler = proc_dointvec,
3217 .procname = "gc_elasticity",
3218 .data = &ip_rt_gc_elasticity,
3219 .maxlen = sizeof(int),
3221 .proc_handler = proc_dointvec,
3224 .procname = "mtu_expires",
3225 .data = &ip_rt_mtu_expires,
3226 .maxlen = sizeof(int),
3228 .proc_handler = proc_dointvec_jiffies,
3231 .procname = "min_pmtu",
3232 .data = &ip_rt_min_pmtu,
3233 .maxlen = sizeof(int),
3235 .proc_handler = proc_dointvec,
3238 .procname = "min_adv_mss",
3239 .data = &ip_rt_min_advmss,
3240 .maxlen = sizeof(int),
3242 .proc_handler = proc_dointvec,
3247 static struct ctl_table empty[1];
3249 static struct ctl_table ipv4_skeleton[] =
3251 { .procname = "route",
3252 .mode = 0555, .child = ipv4_route_table},
3253 { .procname = "neigh",
3254 .mode = 0555, .child = empty},
3258 static __net_initdata struct ctl_path ipv4_path[] = {
3259 { .procname = "net", },
3260 { .procname = "ipv4", },
3264 static struct ctl_table ipv4_route_flush_table[] = {
3266 .procname = "flush",
3267 .maxlen = sizeof(int),
3269 .proc_handler = ipv4_sysctl_rtcache_flush,
3274 static __net_initdata struct ctl_path ipv4_route_path[] = {
3275 { .procname = "net", },
3276 { .procname = "ipv4", },
3277 { .procname = "route", },
3281 static __net_init int sysctl_route_net_init(struct net *net)
3283 struct ctl_table *tbl;
3285 tbl = ipv4_route_flush_table;
3286 if (!net_eq(net, &init_net)) {
3287 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3291 tbl[0].extra1 = net;
3293 net->ipv4.route_hdr =
3294 register_net_sysctl_table(net, ipv4_route_path, tbl);
3295 if (net->ipv4.route_hdr == NULL)
3300 if (tbl != ipv4_route_flush_table)
3306 static __net_exit void sysctl_route_net_exit(struct net *net)
3308 struct ctl_table *tbl;
3310 tbl = net->ipv4.route_hdr->ctl_table_arg;
3311 unregister_net_sysctl_table(net->ipv4.route_hdr);
3312 BUG_ON(tbl == ipv4_route_flush_table);
3316 static __net_initdata struct pernet_operations sysctl_route_ops = {
3317 .init = sysctl_route_net_init,
3318 .exit = sysctl_route_net_exit,
3322 static __net_init int rt_genid_init(struct net *net)
3324 get_random_bytes(&net->ipv4.rt_genid,
3325 sizeof(net->ipv4.rt_genid));
3326 get_random_bytes(&net->ipv4.dev_addr_genid,
3327 sizeof(net->ipv4.dev_addr_genid));
3331 static __net_initdata struct pernet_operations rt_genid_ops = {
3332 .init = rt_genid_init,
3336 #ifdef CONFIG_IP_ROUTE_CLASSID
3337 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3338 #endif /* CONFIG_IP_ROUTE_CLASSID */
3340 static __initdata unsigned long rhash_entries;
3341 static int __init set_rhash_entries(char *str)
3345 rhash_entries = simple_strtoul(str, &str, 0);
3348 __setup("rhash_entries=", set_rhash_entries);
3350 int __init ip_rt_init(void)
3354 #ifdef CONFIG_IP_ROUTE_CLASSID
3355 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3357 panic("IP: failed to allocate ip_rt_acct\n");
3360 ipv4_dst_ops.kmem_cachep =
3361 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3362 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3364 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3366 if (dst_entries_init(&ipv4_dst_ops) < 0)
3367 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3369 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3370 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3372 rt_hash_table = (struct rt_hash_bucket *)
3373 alloc_large_system_hash("IP route cache",
3374 sizeof(struct rt_hash_bucket),
3376 (totalram_pages >= 128 * 1024) ?
3381 rhash_entries ? 0 : 512 * 1024);
3382 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3383 rt_hash_lock_init();
3385 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3386 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3391 if (ip_rt_proc_init())
3392 printk(KERN_ERR "Unable to create route proc files\n");
3395 xfrm4_init(ip_rt_max_size);
3397 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
3399 #ifdef CONFIG_SYSCTL
3400 register_pernet_subsys(&sysctl_route_ops);
3402 register_pernet_subsys(&rt_genid_ops);
3406 #ifdef CONFIG_SYSCTL
3408 * We really need to sanitize the damn ipv4 init order, then all
3409 * this nonsense will go away.
3411 void __init ip_static_sysctl_init(void)
3413 register_sysctl_paths(ipv4_path, ipv4_skeleton);