2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * ROUTE - implementation of the IP router.
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
65 #define pr_fmt(fmt) "IPv4: " fmt
67 #include <linux/module.h>
68 #include <asm/uaccess.h>
69 #include <linux/bitops.h>
70 #include <linux/types.h>
71 #include <linux/kernel.h>
73 #include <linux/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/skbuff.h>
83 #include <linux/inetdevice.h>
84 #include <linux/igmp.h>
85 #include <linux/pkt_sched.h>
86 #include <linux/mroute.h>
87 #include <linux/netfilter_ipv4.h>
88 #include <linux/random.h>
89 #include <linux/rcupdate.h>
90 #include <linux/times.h>
91 #include <linux/slab.h>
93 #include <net/net_namespace.h>
94 #include <net/protocol.h>
96 #include <net/route.h>
97 #include <net/inetpeer.h>
99 #include <net/ip_fib.h>
102 #include <net/icmp.h>
103 #include <net/xfrm.h>
104 #include <net/netevent.h>
105 #include <net/rtnetlink.h>
107 #include <linux/sysctl.h>
108 #include <linux/kmemleak.h>
110 #include <net/secure_seq.h>
112 #define RT_FL_TOS(oldflp4) \
113 ((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_redirect_number __read_mostly = 9;
121 static int ip_rt_redirect_load __read_mostly = HZ / 50;
122 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
123 static int ip_rt_error_cost __read_mostly = HZ;
124 static int ip_rt_error_burst __read_mostly = 5 * HZ;
125 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
126 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
127 static int ip_rt_min_advmss __read_mostly = 256;
130 * Interface to generic destination cache.
133 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
134 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
135 static unsigned int ipv4_mtu(const struct dst_entry *dst);
136 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
137 static void ipv4_link_failure(struct sk_buff *skb);
138 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
139 struct sk_buff *skb, u32 mtu);
140 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
141 struct sk_buff *skb);
142 static void ipv4_dst_destroy(struct dst_entry *dst);
144 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
149 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
155 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
159 static struct dst_ops ipv4_dst_ops = {
161 .protocol = cpu_to_be16(ETH_P_IP),
162 .check = ipv4_dst_check,
163 .default_advmss = ipv4_default_advmss,
165 .cow_metrics = ipv4_cow_metrics,
166 .destroy = ipv4_dst_destroy,
167 .ifdown = ipv4_dst_ifdown,
168 .negative_advice = ipv4_negative_advice,
169 .link_failure = ipv4_link_failure,
170 .update_pmtu = ip_rt_update_pmtu,
171 .redirect = ip_do_redirect,
172 .local_out = __ip_local_out,
173 .neigh_lookup = ipv4_neigh_lookup,
176 #define ECN_OR_COST(class) TC_PRIO_##class
178 const __u8 ip_tos2prio[16] = {
180 ECN_OR_COST(BESTEFFORT),
182 ECN_OR_COST(BESTEFFORT),
188 ECN_OR_COST(INTERACTIVE),
190 ECN_OR_COST(INTERACTIVE),
191 TC_PRIO_INTERACTIVE_BULK,
192 ECN_OR_COST(INTERACTIVE_BULK),
193 TC_PRIO_INTERACTIVE_BULK,
194 ECN_OR_COST(INTERACTIVE_BULK)
196 EXPORT_SYMBOL(ip_tos2prio);
198 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
199 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
201 #ifdef CONFIG_PROC_FS
202 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
206 return SEQ_START_TOKEN;
209 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
215 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
219 static int rt_cache_seq_show(struct seq_file *seq, void *v)
221 if (v == SEQ_START_TOKEN)
222 seq_printf(seq, "%-127s\n",
223 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
224 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
229 static const struct seq_operations rt_cache_seq_ops = {
230 .start = rt_cache_seq_start,
231 .next = rt_cache_seq_next,
232 .stop = rt_cache_seq_stop,
233 .show = rt_cache_seq_show,
236 static int rt_cache_seq_open(struct inode *inode, struct file *file)
238 return seq_open(file, &rt_cache_seq_ops);
241 static const struct file_operations rt_cache_seq_fops = {
242 .owner = THIS_MODULE,
243 .open = rt_cache_seq_open,
246 .release = seq_release,
250 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
255 return SEQ_START_TOKEN;
257 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
258 if (!cpu_possible(cpu))
261 return &per_cpu(rt_cache_stat, cpu);
266 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
270 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
271 if (!cpu_possible(cpu))
274 return &per_cpu(rt_cache_stat, cpu);
280 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
285 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
287 struct rt_cache_stat *st = v;
289 if (v == SEQ_START_TOKEN) {
290 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");
294 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
295 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
296 dst_entries_get_slow(&ipv4_dst_ops),
319 static const struct seq_operations rt_cpu_seq_ops = {
320 .start = rt_cpu_seq_start,
321 .next = rt_cpu_seq_next,
322 .stop = rt_cpu_seq_stop,
323 .show = rt_cpu_seq_show,
327 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
329 return seq_open(file, &rt_cpu_seq_ops);
332 static const struct file_operations rt_cpu_seq_fops = {
333 .owner = THIS_MODULE,
334 .open = rt_cpu_seq_open,
337 .release = seq_release,
340 #ifdef CONFIG_IP_ROUTE_CLASSID
341 static int rt_acct_proc_show(struct seq_file *m, void *v)
343 struct ip_rt_acct *dst, *src;
346 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
350 for_each_possible_cpu(i) {
351 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
352 for (j = 0; j < 256; j++) {
353 dst[j].o_bytes += src[j].o_bytes;
354 dst[j].o_packets += src[j].o_packets;
355 dst[j].i_bytes += src[j].i_bytes;
356 dst[j].i_packets += src[j].i_packets;
360 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
365 static int rt_acct_proc_open(struct inode *inode, struct file *file)
367 return single_open(file, rt_acct_proc_show, NULL);
370 static const struct file_operations rt_acct_proc_fops = {
371 .owner = THIS_MODULE,
372 .open = rt_acct_proc_open,
375 .release = single_release,
379 static int __net_init ip_rt_do_proc_init(struct net *net)
381 struct proc_dir_entry *pde;
383 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
388 pde = proc_create("rt_cache", S_IRUGO,
389 net->proc_net_stat, &rt_cpu_seq_fops);
393 #ifdef CONFIG_IP_ROUTE_CLASSID
394 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
400 #ifdef CONFIG_IP_ROUTE_CLASSID
402 remove_proc_entry("rt_cache", net->proc_net_stat);
405 remove_proc_entry("rt_cache", net->proc_net);
410 static void __net_exit ip_rt_do_proc_exit(struct net *net)
412 remove_proc_entry("rt_cache", net->proc_net_stat);
413 remove_proc_entry("rt_cache", net->proc_net);
414 #ifdef CONFIG_IP_ROUTE_CLASSID
415 remove_proc_entry("rt_acct", net->proc_net);
419 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
420 .init = ip_rt_do_proc_init,
421 .exit = ip_rt_do_proc_exit,
424 static int __init ip_rt_proc_init(void)
426 return register_pernet_subsys(&ip_rt_proc_ops);
430 static inline int ip_rt_proc_init(void)
434 #endif /* CONFIG_PROC_FS */
436 static inline bool rt_is_expired(const struct rtable *rth)
438 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
441 void rt_cache_flush(struct net *net)
446 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
450 struct net_device *dev = dst->dev;
451 const __be32 *pkey = daddr;
452 const struct rtable *rt;
455 rt = (const struct rtable *) dst;
457 pkey = (const __be32 *) &rt->rt_gateway;
459 pkey = &ip_hdr(skb)->daddr;
461 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
464 return neigh_create(&arp_tbl, pkey, dev);
468 * Peer allocation may fail only in serious out-of-memory conditions. However
469 * we still can generate some output.
470 * Random ID selection looks a bit dangerous because we have no chances to
471 * select ID being unique in a reasonable period of time.
472 * But broken packet identifier may be better than no packet at all.
474 static void ip_select_fb_ident(struct iphdr *iph)
476 static DEFINE_SPINLOCK(ip_fb_id_lock);
477 static u32 ip_fallback_id;
480 spin_lock_bh(&ip_fb_id_lock);
481 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
482 iph->id = htons(salt & 0xFFFF);
483 ip_fallback_id = salt;
484 spin_unlock_bh(&ip_fb_id_lock);
487 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
489 struct net *net = dev_net(dst->dev);
490 struct inet_peer *peer;
492 peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1);
494 iph->id = htons(inet_getid(peer, more));
499 ip_select_fb_ident(iph);
501 EXPORT_SYMBOL(__ip_select_ident);
503 static void __build_flow_key(struct flowi4 *fl4, struct sock *sk,
504 const struct iphdr *iph,
506 u8 prot, u32 mark, int flow_flags)
509 const struct inet_sock *inet = inet_sk(sk);
511 oif = sk->sk_bound_dev_if;
513 tos = RT_CONN_FLAGS(sk);
514 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
516 flowi4_init_output(fl4, oif, mark, tos,
517 RT_SCOPE_UNIVERSE, prot,
519 iph->daddr, iph->saddr, 0, 0,
520 sk ? sock_i_uid(sk) : 0);
523 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
526 const struct iphdr *iph = ip_hdr(skb);
527 int oif = skb->dev->ifindex;
528 u8 tos = RT_TOS(iph->tos);
529 u8 prot = iph->protocol;
530 u32 mark = skb->mark;
532 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
535 static void build_sk_flow_key(struct flowi4 *fl4, struct sock *sk)
537 const struct inet_sock *inet = inet_sk(sk);
538 const struct ip_options_rcu *inet_opt;
539 __be32 daddr = inet->inet_daddr;
542 inet_opt = rcu_dereference(inet->inet_opt);
543 if (inet_opt && inet_opt->opt.srr)
544 daddr = inet_opt->opt.faddr;
545 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
546 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
547 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
548 inet_sk_flowi_flags(sk),
549 daddr, inet->inet_saddr, 0, 0,
554 static void ip_rt_build_flow_key(struct flowi4 *fl4, struct sock *sk,
555 const struct sk_buff *skb)
558 build_skb_flow_key(fl4, skb, sk);
560 build_sk_flow_key(fl4, sk);
563 static inline void rt_free(struct rtable *rt)
565 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
568 static DEFINE_SPINLOCK(fnhe_lock);
570 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
572 struct fib_nh_exception *fnhe, *oldest;
575 oldest = rcu_dereference(hash->chain);
576 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
577 fnhe = rcu_dereference(fnhe->fnhe_next)) {
578 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
581 orig = rcu_dereference(oldest->fnhe_rth);
583 RCU_INIT_POINTER(oldest->fnhe_rth, NULL);
589 static inline u32 fnhe_hashfun(__be32 daddr)
593 hval = (__force u32) daddr;
594 hval ^= (hval >> 11) ^ (hval >> 22);
596 return hval & (FNHE_HASH_SIZE - 1);
599 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
600 u32 pmtu, unsigned long expires)
602 struct fnhe_hash_bucket *hash;
603 struct fib_nh_exception *fnhe;
605 u32 hval = fnhe_hashfun(daddr);
607 spin_lock_bh(&fnhe_lock);
609 hash = nh->nh_exceptions;
611 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
614 nh->nh_exceptions = hash;
620 for (fnhe = rcu_dereference(hash->chain); fnhe;
621 fnhe = rcu_dereference(fnhe->fnhe_next)) {
622 if (fnhe->fnhe_daddr == daddr)
631 fnhe->fnhe_pmtu = pmtu;
632 fnhe->fnhe_expires = expires;
635 if (depth > FNHE_RECLAIM_DEPTH)
636 fnhe = fnhe_oldest(hash);
638 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
642 fnhe->fnhe_next = hash->chain;
643 rcu_assign_pointer(hash->chain, fnhe);
645 fnhe->fnhe_daddr = daddr;
647 fnhe->fnhe_pmtu = pmtu;
648 fnhe->fnhe_expires = expires;
651 fnhe->fnhe_stamp = jiffies;
654 spin_unlock_bh(&fnhe_lock);
658 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
661 __be32 new_gw = icmp_hdr(skb)->un.gateway;
662 __be32 old_gw = ip_hdr(skb)->saddr;
663 struct net_device *dev = skb->dev;
664 struct in_device *in_dev;
665 struct fib_result res;
669 switch (icmp_hdr(skb)->code & 7) {
671 case ICMP_REDIR_NETTOS:
672 case ICMP_REDIR_HOST:
673 case ICMP_REDIR_HOSTTOS:
680 if (rt->rt_gateway != old_gw)
683 in_dev = __in_dev_get_rcu(dev);
688 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
689 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
690 ipv4_is_zeronet(new_gw))
691 goto reject_redirect;
693 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
694 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
695 goto reject_redirect;
696 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
697 goto reject_redirect;
699 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
700 goto reject_redirect;
703 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
705 if (!(n->nud_state & NUD_VALID)) {
706 neigh_event_send(n, NULL);
708 if (fib_lookup(net, fl4, &res) == 0) {
709 struct fib_nh *nh = &FIB_RES_NH(res);
711 update_or_create_fnhe(nh, fl4->daddr, new_gw,
715 rt->dst.obsolete = DST_OBSOLETE_KILL;
716 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
723 #ifdef CONFIG_IP_ROUTE_VERBOSE
724 if (IN_DEV_LOG_MARTIANS(in_dev)) {
725 const struct iphdr *iph = (const struct iphdr *) skb->data;
726 __be32 daddr = iph->daddr;
727 __be32 saddr = iph->saddr;
729 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
730 " Advised path = %pI4 -> %pI4\n",
731 &old_gw, dev->name, &new_gw,
738 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
742 const struct iphdr *iph = (const struct iphdr *) skb->data;
743 int oif = skb->dev->ifindex;
744 u8 tos = RT_TOS(iph->tos);
745 u8 prot = iph->protocol;
746 u32 mark = skb->mark;
748 rt = (struct rtable *) dst;
750 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
751 __ip_do_redirect(rt, skb, &fl4, true);
754 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
756 struct rtable *rt = (struct rtable *)dst;
757 struct dst_entry *ret = dst;
760 if (dst->obsolete > 0) {
763 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
774 * 1. The first ip_rt_redirect_number redirects are sent
775 * with exponential backoff, then we stop sending them at all,
776 * assuming that the host ignores our redirects.
777 * 2. If we did not see packets requiring redirects
778 * during ip_rt_redirect_silence, we assume that the host
779 * forgot redirected route and start to send redirects again.
781 * This algorithm is much cheaper and more intelligent than dumb load limiting
784 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
785 * and "frag. need" (breaks PMTU discovery) in icmp.c.
788 void ip_rt_send_redirect(struct sk_buff *skb)
790 struct rtable *rt = skb_rtable(skb);
791 struct in_device *in_dev;
792 struct inet_peer *peer;
797 in_dev = __in_dev_get_rcu(rt->dst.dev);
798 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
802 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
805 net = dev_net(rt->dst.dev);
806 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
808 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
809 rt_nexthop(rt, ip_hdr(skb)->daddr));
813 /* No redirected packets during ip_rt_redirect_silence;
814 * reset the algorithm.
816 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
817 peer->rate_tokens = 0;
819 /* Too many ignored redirects; do not send anything
820 * set dst.rate_last to the last seen redirected packet.
822 if (peer->rate_tokens >= ip_rt_redirect_number) {
823 peer->rate_last = jiffies;
827 /* Check for load limit; set rate_last to the latest sent
830 if (peer->rate_tokens == 0 ||
833 (ip_rt_redirect_load << peer->rate_tokens)))) {
834 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
836 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
837 peer->rate_last = jiffies;
839 #ifdef CONFIG_IP_ROUTE_VERBOSE
841 peer->rate_tokens == ip_rt_redirect_number)
842 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
843 &ip_hdr(skb)->saddr, inet_iif(skb),
844 &ip_hdr(skb)->daddr, &gw);
851 static int ip_error(struct sk_buff *skb)
853 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
854 struct rtable *rt = skb_rtable(skb);
855 struct inet_peer *peer;
861 net = dev_net(rt->dst.dev);
862 if (!IN_DEV_FORWARD(in_dev)) {
863 switch (rt->dst.error) {
865 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
869 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
875 switch (rt->dst.error) {
880 code = ICMP_HOST_UNREACH;
883 code = ICMP_NET_UNREACH;
884 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
887 code = ICMP_PKT_FILTERED;
891 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
896 peer->rate_tokens += now - peer->rate_last;
897 if (peer->rate_tokens > ip_rt_error_burst)
898 peer->rate_tokens = ip_rt_error_burst;
899 peer->rate_last = now;
900 if (peer->rate_tokens >= ip_rt_error_cost)
901 peer->rate_tokens -= ip_rt_error_cost;
907 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
913 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
915 struct dst_entry *dst = &rt->dst;
916 struct fib_result res;
918 if (dst_metric_locked(dst, RTAX_MTU))
921 if (dst->dev->mtu < mtu)
924 if (mtu < ip_rt_min_pmtu)
925 mtu = ip_rt_min_pmtu;
928 dst->obsolete = DST_OBSOLETE_KILL;
931 dst->expires = max(1UL, jiffies + ip_rt_mtu_expires);
935 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
936 struct fib_nh *nh = &FIB_RES_NH(res);
938 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
939 jiffies + ip_rt_mtu_expires);
944 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
945 struct sk_buff *skb, u32 mtu)
947 struct rtable *rt = (struct rtable *) dst;
950 ip_rt_build_flow_key(&fl4, sk, skb);
951 __ip_rt_update_pmtu(rt, &fl4, mtu);
954 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
955 int oif, u32 mark, u8 protocol, int flow_flags)
957 const struct iphdr *iph = (const struct iphdr *) skb->data;
962 mark = IP4_REPLY_MARK(net, skb->mark);
964 __build_flow_key(&fl4, NULL, iph, oif,
965 RT_TOS(iph->tos), protocol, mark, flow_flags);
966 rt = __ip_route_output_key(net, &fl4);
968 __ip_rt_update_pmtu(rt, &fl4, mtu);
972 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
974 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
976 const struct iphdr *iph = (const struct iphdr *) skb->data;
980 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
982 if (!fl4.flowi4_mark)
983 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
985 rt = __ip_route_output_key(sock_net(sk), &fl4);
987 __ip_rt_update_pmtu(rt, &fl4, mtu);
992 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
994 const struct iphdr *iph = (const struct iphdr *) skb->data;
997 struct dst_entry *dst;
1001 rt = (struct rtable *) __sk_dst_get(sk);
1003 if (sock_owned_by_user(sk) || !rt) {
1004 __ipv4_sk_update_pmtu(skb, sk, mtu);
1008 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1010 if (!__sk_dst_check(sk, 0)) {
1011 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1018 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1020 dst = dst_check(&rt->dst, 0);
1023 dst_release(&rt->dst);
1025 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1033 __sk_dst_set(sk, &rt->dst);
1038 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1040 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1041 int oif, u32 mark, u8 protocol, int flow_flags)
1043 const struct iphdr *iph = (const struct iphdr *) skb->data;
1047 __build_flow_key(&fl4, NULL, iph, oif,
1048 RT_TOS(iph->tos), protocol, mark, flow_flags);
1049 rt = __ip_route_output_key(net, &fl4);
1051 __ip_do_redirect(rt, skb, &fl4, false);
1055 EXPORT_SYMBOL_GPL(ipv4_redirect);
1057 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1059 const struct iphdr *iph = (const struct iphdr *) skb->data;
1063 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1064 rt = __ip_route_output_key(sock_net(sk), &fl4);
1066 __ip_do_redirect(rt, skb, &fl4, false);
1070 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1072 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1074 struct rtable *rt = (struct rtable *) dst;
1076 /* All IPV4 dsts are created with ->obsolete set to the value
1077 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1078 * into this function always.
1080 * When a PMTU/redirect information update invalidates a
1081 * route, this is indicated by setting obsolete to
1082 * DST_OBSOLETE_KILL.
1084 if (dst->obsolete == DST_OBSOLETE_KILL || rt_is_expired(rt))
1089 static void ipv4_link_failure(struct sk_buff *skb)
1093 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1095 rt = skb_rtable(skb);
1097 dst_set_expires(&rt->dst, 0);
1100 static int ip_rt_bug(struct sk_buff *skb)
1102 pr_debug("%s: %pI4 -> %pI4, %s\n",
1103 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1104 skb->dev ? skb->dev->name : "?");
1111 We do not cache source address of outgoing interface,
1112 because it is used only by IP RR, TS and SRR options,
1113 so that it out of fast path.
1115 BTW remember: "addr" is allowed to be not aligned
1119 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1123 if (rt_is_output_route(rt))
1124 src = ip_hdr(skb)->saddr;
1126 struct fib_result res;
1132 memset(&fl4, 0, sizeof(fl4));
1133 fl4.daddr = iph->daddr;
1134 fl4.saddr = iph->saddr;
1135 fl4.flowi4_tos = RT_TOS(iph->tos);
1136 fl4.flowi4_oif = rt->dst.dev->ifindex;
1137 fl4.flowi4_iif = skb->dev->ifindex;
1138 fl4.flowi4_mark = skb->mark;
1141 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1142 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1144 src = inet_select_addr(rt->dst.dev,
1145 rt_nexthop(rt, iph->daddr),
1149 memcpy(addr, &src, 4);
1152 #ifdef CONFIG_IP_ROUTE_CLASSID
1153 static void set_class_tag(struct rtable *rt, u32 tag)
1155 if (!(rt->dst.tclassid & 0xFFFF))
1156 rt->dst.tclassid |= tag & 0xFFFF;
1157 if (!(rt->dst.tclassid & 0xFFFF0000))
1158 rt->dst.tclassid |= tag & 0xFFFF0000;
1162 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1164 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1167 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1169 if (advmss > 65535 - 40)
1170 advmss = 65535 - 40;
1175 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1177 const struct rtable *rt = (const struct rtable *) dst;
1178 unsigned int mtu = rt->rt_pmtu;
1180 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1181 mtu = dst_metric_raw(dst, RTAX_MTU);
1186 mtu = dst->dev->mtu;
1188 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1189 if (rt->rt_uses_gateway && mtu > 576)
1193 if (mtu > IP_MAX_MTU)
1199 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1201 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1202 struct fib_nh_exception *fnhe;
1208 hval = fnhe_hashfun(daddr);
1210 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1211 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1212 if (fnhe->fnhe_daddr == daddr)
1218 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1223 spin_lock_bh(&fnhe_lock);
1225 if (daddr == fnhe->fnhe_daddr) {
1226 struct rtable *orig = rcu_dereference(fnhe->fnhe_rth);
1227 if (orig && rt_is_expired(orig)) {
1229 fnhe->fnhe_pmtu = 0;
1230 fnhe->fnhe_expires = 0;
1232 if (fnhe->fnhe_pmtu) {
1233 unsigned long expires = fnhe->fnhe_expires;
1234 unsigned long diff = expires - jiffies;
1236 if (time_before(jiffies, expires)) {
1237 rt->rt_pmtu = fnhe->fnhe_pmtu;
1238 dst_set_expires(&rt->dst, diff);
1241 if (fnhe->fnhe_gw) {
1242 rt->rt_flags |= RTCF_REDIRECTED;
1243 rt->rt_gateway = fnhe->fnhe_gw;
1244 rt->rt_uses_gateway = 1;
1245 } else if (!rt->rt_gateway)
1246 rt->rt_gateway = daddr;
1248 rcu_assign_pointer(fnhe->fnhe_rth, rt);
1252 fnhe->fnhe_stamp = jiffies;
1255 spin_unlock_bh(&fnhe_lock);
1260 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1262 struct rtable *orig, *prev, **p;
1265 if (rt_is_input_route(rt)) {
1266 p = (struct rtable **)&nh->nh_rth_input;
1268 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1272 prev = cmpxchg(p, orig, rt);
1282 static DEFINE_SPINLOCK(rt_uncached_lock);
1283 static LIST_HEAD(rt_uncached_list);
1285 static void rt_add_uncached_list(struct rtable *rt)
1287 spin_lock_bh(&rt_uncached_lock);
1288 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1289 spin_unlock_bh(&rt_uncached_lock);
1292 static void ipv4_dst_destroy(struct dst_entry *dst)
1294 struct rtable *rt = (struct rtable *) dst;
1296 if (!list_empty(&rt->rt_uncached)) {
1297 spin_lock_bh(&rt_uncached_lock);
1298 list_del(&rt->rt_uncached);
1299 spin_unlock_bh(&rt_uncached_lock);
1303 void rt_flush_dev(struct net_device *dev)
1305 if (!list_empty(&rt_uncached_list)) {
1306 struct net *net = dev_net(dev);
1309 spin_lock_bh(&rt_uncached_lock);
1310 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1311 if (rt->dst.dev != dev)
1313 rt->dst.dev = net->loopback_dev;
1314 dev_hold(rt->dst.dev);
1317 spin_unlock_bh(&rt_uncached_lock);
1321 static bool rt_cache_valid(const struct rtable *rt)
1324 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1328 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1329 const struct fib_result *res,
1330 struct fib_nh_exception *fnhe,
1331 struct fib_info *fi, u16 type, u32 itag)
1333 bool cached = false;
1336 struct fib_nh *nh = &FIB_RES_NH(*res);
1338 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1339 rt->rt_gateway = nh->nh_gw;
1340 rt->rt_uses_gateway = 1;
1342 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1343 #ifdef CONFIG_IP_ROUTE_CLASSID
1344 rt->dst.tclassid = nh->nh_tclassid;
1347 cached = rt_bind_exception(rt, fnhe, daddr);
1348 else if (!(rt->dst.flags & DST_NOCACHE))
1349 cached = rt_cache_route(nh, rt);
1350 if (unlikely(!cached)) {
1351 /* Routes we intend to cache in nexthop exception or
1352 * FIB nexthop have the DST_NOCACHE bit clear.
1353 * However, if we are unsuccessful at storing this
1354 * route into the cache we really need to set it.
1356 rt->dst.flags |= DST_NOCACHE;
1357 if (!rt->rt_gateway)
1358 rt->rt_gateway = daddr;
1359 rt_add_uncached_list(rt);
1362 rt_add_uncached_list(rt);
1364 #ifdef CONFIG_IP_ROUTE_CLASSID
1365 #ifdef CONFIG_IP_MULTIPLE_TABLES
1366 set_class_tag(rt, res->tclassid);
1368 set_class_tag(rt, itag);
1372 static struct rtable *rt_dst_alloc(struct net_device *dev,
1373 bool nopolicy, bool noxfrm, bool will_cache)
1375 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1376 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1377 (nopolicy ? DST_NOPOLICY : 0) |
1378 (noxfrm ? DST_NOXFRM : 0));
1381 /* called in rcu_read_lock() section */
1382 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1383 u8 tos, struct net_device *dev, int our)
1386 struct in_device *in_dev = __in_dev_get_rcu(dev);
1390 /* Primary sanity checks. */
1395 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1396 skb->protocol != htons(ETH_P_IP))
1399 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1400 if (ipv4_is_loopback(saddr))
1403 if (ipv4_is_zeronet(saddr)) {
1404 if (!ipv4_is_local_multicast(daddr))
1407 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1412 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1413 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1417 #ifdef CONFIG_IP_ROUTE_CLASSID
1418 rth->dst.tclassid = itag;
1420 rth->dst.output = ip_rt_bug;
1422 rth->rt_genid = rt_genid(dev_net(dev));
1423 rth->rt_flags = RTCF_MULTICAST;
1424 rth->rt_type = RTN_MULTICAST;
1425 rth->rt_is_input= 1;
1428 rth->rt_gateway = 0;
1429 rth->rt_uses_gateway = 0;
1430 INIT_LIST_HEAD(&rth->rt_uncached);
1432 rth->dst.input= ip_local_deliver;
1433 rth->rt_flags |= RTCF_LOCAL;
1436 #ifdef CONFIG_IP_MROUTE
1437 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1438 rth->dst.input = ip_mr_input;
1440 RT_CACHE_STAT_INC(in_slow_mc);
1442 skb_dst_set(skb, &rth->dst);
1454 static void ip_handle_martian_source(struct net_device *dev,
1455 struct in_device *in_dev,
1456 struct sk_buff *skb,
1460 RT_CACHE_STAT_INC(in_martian_src);
1461 #ifdef CONFIG_IP_ROUTE_VERBOSE
1462 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1464 * RFC1812 recommendation, if source is martian,
1465 * the only hint is MAC header.
1467 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1468 &daddr, &saddr, dev->name);
1469 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1470 print_hex_dump(KERN_WARNING, "ll header: ",
1471 DUMP_PREFIX_OFFSET, 16, 1,
1472 skb_mac_header(skb),
1473 dev->hard_header_len, true);
1479 /* called in rcu_read_lock() section */
1480 static int __mkroute_input(struct sk_buff *skb,
1481 const struct fib_result *res,
1482 struct in_device *in_dev,
1483 __be32 daddr, __be32 saddr, u32 tos)
1487 struct in_device *out_dev;
1488 unsigned int flags = 0;
1492 /* get a working reference to the output device */
1493 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1494 if (out_dev == NULL) {
1495 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1499 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1500 in_dev->dev, in_dev, &itag);
1502 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1508 do_cache = res->fi && !itag;
1509 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1510 (IN_DEV_SHARED_MEDIA(out_dev) ||
1511 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) {
1512 flags |= RTCF_DOREDIRECT;
1516 if (skb->protocol != htons(ETH_P_IP)) {
1517 /* Not IP (i.e. ARP). Do not create route, if it is
1518 * invalid for proxy arp. DNAT routes are always valid.
1520 * Proxy arp feature have been extended to allow, ARP
1521 * replies back to the same interface, to support
1522 * Private VLAN switch technologies. See arp.c.
1524 if (out_dev == in_dev &&
1525 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1532 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1533 if (rt_cache_valid(rth)) {
1534 skb_dst_set_noref(skb, &rth->dst);
1539 rth = rt_dst_alloc(out_dev->dev,
1540 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1541 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1547 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
1548 rth->rt_flags = flags;
1549 rth->rt_type = res->type;
1550 rth->rt_is_input = 1;
1553 rth->rt_gateway = 0;
1554 rth->rt_uses_gateway = 0;
1555 INIT_LIST_HEAD(&rth->rt_uncached);
1557 rth->dst.input = ip_forward;
1558 rth->dst.output = ip_output;
1560 rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag);
1561 skb_dst_set(skb, &rth->dst);
1568 static int ip_mkroute_input(struct sk_buff *skb,
1569 struct fib_result *res,
1570 const struct flowi4 *fl4,
1571 struct in_device *in_dev,
1572 __be32 daddr, __be32 saddr, u32 tos)
1574 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1575 if (res->fi && res->fi->fib_nhs > 1)
1576 fib_select_multipath(res);
1579 /* create a routing cache entry */
1580 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1584 * NOTE. We drop all the packets that has local source
1585 * addresses, because every properly looped back packet
1586 * must have correct destination already attached by output routine.
1588 * Such approach solves two big problems:
1589 * 1. Not simplex devices are handled properly.
1590 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1591 * called with rcu_read_lock()
1594 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1595 u8 tos, struct net_device *dev)
1597 struct fib_result res;
1598 struct in_device *in_dev = __in_dev_get_rcu(dev);
1600 unsigned int flags = 0;
1604 struct net *net = dev_net(dev);
1607 /* IP on this device is disabled. */
1612 /* Check for the most weird martians, which can be not detected
1616 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1617 goto martian_source;
1620 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1623 /* Accept zero addresses only to limited broadcast;
1624 * I even do not know to fix it or not. Waiting for complains :-)
1626 if (ipv4_is_zeronet(saddr))
1627 goto martian_source;
1629 if (ipv4_is_zeronet(daddr))
1630 goto martian_destination;
1632 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1633 * and call it once if daddr or/and saddr are loopback addresses
1635 if (ipv4_is_loopback(daddr)) {
1636 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1637 goto martian_destination;
1638 } else if (ipv4_is_loopback(saddr)) {
1639 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1640 goto martian_source;
1644 * Now we are ready to route packet.
1647 fl4.flowi4_iif = dev->ifindex;
1648 fl4.flowi4_mark = skb->mark;
1649 fl4.flowi4_tos = tos;
1650 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1653 err = fib_lookup(net, &fl4, &res);
1657 RT_CACHE_STAT_INC(in_slow_tot);
1659 if (res.type == RTN_BROADCAST)
1662 if (res.type == RTN_LOCAL) {
1663 err = fib_validate_source(skb, saddr, daddr, tos,
1665 dev, in_dev, &itag);
1667 goto martian_source_keep_err;
1671 if (!IN_DEV_FORWARD(in_dev))
1673 if (res.type != RTN_UNICAST)
1674 goto martian_destination;
1676 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1680 if (skb->protocol != htons(ETH_P_IP))
1683 if (!ipv4_is_zeronet(saddr)) {
1684 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1687 goto martian_source_keep_err;
1689 flags |= RTCF_BROADCAST;
1690 res.type = RTN_BROADCAST;
1691 RT_CACHE_STAT_INC(in_brd);
1697 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1698 if (rt_cache_valid(rth)) {
1699 skb_dst_set_noref(skb, &rth->dst);
1707 rth = rt_dst_alloc(net->loopback_dev,
1708 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1712 rth->dst.input= ip_local_deliver;
1713 rth->dst.output= ip_rt_bug;
1714 #ifdef CONFIG_IP_ROUTE_CLASSID
1715 rth->dst.tclassid = itag;
1718 rth->rt_genid = rt_genid(net);
1719 rth->rt_flags = flags|RTCF_LOCAL;
1720 rth->rt_type = res.type;
1721 rth->rt_is_input = 1;
1724 rth->rt_gateway = 0;
1725 rth->rt_uses_gateway = 0;
1726 INIT_LIST_HEAD(&rth->rt_uncached);
1727 if (res.type == RTN_UNREACHABLE) {
1728 rth->dst.input= ip_error;
1729 rth->dst.error= -err;
1730 rth->rt_flags &= ~RTCF_LOCAL;
1733 rt_cache_route(&FIB_RES_NH(res), rth);
1734 skb_dst_set(skb, &rth->dst);
1739 RT_CACHE_STAT_INC(in_no_route);
1740 res.type = RTN_UNREACHABLE;
1746 * Do not cache martian addresses: they should be logged (RFC1812)
1748 martian_destination:
1749 RT_CACHE_STAT_INC(in_martian_dst);
1750 #ifdef CONFIG_IP_ROUTE_VERBOSE
1751 if (IN_DEV_LOG_MARTIANS(in_dev))
1752 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1753 &daddr, &saddr, dev->name);
1766 martian_source_keep_err:
1767 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1771 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1772 u8 tos, struct net_device *dev)
1778 /* Multicast recognition logic is moved from route cache to here.
1779 The problem was that too many Ethernet cards have broken/missing
1780 hardware multicast filters :-( As result the host on multicasting
1781 network acquires a lot of useless route cache entries, sort of
1782 SDR messages from all the world. Now we try to get rid of them.
1783 Really, provided software IP multicast filter is organized
1784 reasonably (at least, hashed), it does not result in a slowdown
1785 comparing with route cache reject entries.
1786 Note, that multicast routers are not affected, because
1787 route cache entry is created eventually.
1789 if (ipv4_is_multicast(daddr)) {
1790 struct in_device *in_dev = __in_dev_get_rcu(dev);
1793 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1794 ip_hdr(skb)->protocol);
1796 #ifdef CONFIG_IP_MROUTE
1798 (!ipv4_is_local_multicast(daddr) &&
1799 IN_DEV_MFORWARD(in_dev))
1802 int res = ip_route_input_mc(skb, daddr, saddr,
1811 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1815 EXPORT_SYMBOL(ip_route_input_noref);
1817 /* called with rcu_read_lock() */
1818 static struct rtable *__mkroute_output(const struct fib_result *res,
1819 const struct flowi4 *fl4, int orig_oif,
1820 struct net_device *dev_out,
1823 struct fib_info *fi = res->fi;
1824 struct fib_nh_exception *fnhe;
1825 struct in_device *in_dev;
1826 u16 type = res->type;
1830 in_dev = __in_dev_get_rcu(dev_out);
1832 return ERR_PTR(-EINVAL);
1834 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1835 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1836 return ERR_PTR(-EINVAL);
1838 if (ipv4_is_lbcast(fl4->daddr))
1839 type = RTN_BROADCAST;
1840 else if (ipv4_is_multicast(fl4->daddr))
1841 type = RTN_MULTICAST;
1842 else if (ipv4_is_zeronet(fl4->daddr))
1843 return ERR_PTR(-EINVAL);
1845 if (dev_out->flags & IFF_LOOPBACK)
1846 flags |= RTCF_LOCAL;
1849 if (type == RTN_BROADCAST) {
1850 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1852 } else if (type == RTN_MULTICAST) {
1853 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1854 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1856 flags &= ~RTCF_LOCAL;
1859 /* If multicast route do not exist use
1860 * default one, but do not gateway in this case.
1863 if (fi && res->prefixlen < 4)
1868 do_cache &= fi != NULL;
1870 struct rtable __rcu **prth;
1871 struct fib_nh *nh = &FIB_RES_NH(*res);
1873 fnhe = find_exception(nh, fl4->daddr);
1875 prth = &fnhe->fnhe_rth;
1877 if (unlikely(fl4->flowi4_flags &
1878 FLOWI_FLAG_KNOWN_NH &&
1880 nh->nh_scope == RT_SCOPE_LINK))) {
1884 prth = __this_cpu_ptr(nh->nh_pcpu_rth_output);
1886 rth = rcu_dereference(*prth);
1887 if (rt_cache_valid(rth)) {
1888 dst_hold(&rth->dst);
1894 rth = rt_dst_alloc(dev_out,
1895 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1896 IN_DEV_CONF_GET(in_dev, NOXFRM),
1899 return ERR_PTR(-ENOBUFS);
1901 rth->dst.output = ip_output;
1903 rth->rt_genid = rt_genid(dev_net(dev_out));
1904 rth->rt_flags = flags;
1905 rth->rt_type = type;
1906 rth->rt_is_input = 0;
1907 rth->rt_iif = orig_oif ? : 0;
1909 rth->rt_gateway = 0;
1910 rth->rt_uses_gateway = 0;
1911 INIT_LIST_HEAD(&rth->rt_uncached);
1913 RT_CACHE_STAT_INC(out_slow_tot);
1915 if (flags & RTCF_LOCAL)
1916 rth->dst.input = ip_local_deliver;
1917 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1918 if (flags & RTCF_LOCAL &&
1919 !(dev_out->flags & IFF_LOOPBACK)) {
1920 rth->dst.output = ip_mc_output;
1921 RT_CACHE_STAT_INC(out_slow_mc);
1923 #ifdef CONFIG_IP_MROUTE
1924 if (type == RTN_MULTICAST) {
1925 if (IN_DEV_MFORWARD(in_dev) &&
1926 !ipv4_is_local_multicast(fl4->daddr)) {
1927 rth->dst.input = ip_mr_input;
1928 rth->dst.output = ip_mc_output;
1934 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1940 * Major route resolver routine.
1943 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1945 struct net_device *dev_out = NULL;
1946 __u8 tos = RT_FL_TOS(fl4);
1947 unsigned int flags = 0;
1948 struct fib_result res;
1956 orig_oif = fl4->flowi4_oif;
1958 fl4->flowi4_iif = LOOPBACK_IFINDEX;
1959 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
1960 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
1961 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
1965 rth = ERR_PTR(-EINVAL);
1966 if (ipv4_is_multicast(fl4->saddr) ||
1967 ipv4_is_lbcast(fl4->saddr) ||
1968 ipv4_is_zeronet(fl4->saddr))
1971 /* I removed check for oif == dev_out->oif here.
1972 It was wrong for two reasons:
1973 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
1974 is assigned to multiple interfaces.
1975 2. Moreover, we are allowed to send packets with saddr
1976 of another iface. --ANK
1979 if (fl4->flowi4_oif == 0 &&
1980 (ipv4_is_multicast(fl4->daddr) ||
1981 ipv4_is_lbcast(fl4->daddr))) {
1982 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1983 dev_out = __ip_dev_find(net, fl4->saddr, false);
1984 if (dev_out == NULL)
1987 /* Special hack: user can direct multicasts
1988 and limited broadcast via necessary interface
1989 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
1990 This hack is not just for fun, it allows
1991 vic,vat and friends to work.
1992 They bind socket to loopback, set ttl to zero
1993 and expect that it will work.
1994 From the viewpoint of routing cache they are broken,
1995 because we are not allowed to build multicast path
1996 with loopback source addr (look, routing cache
1997 cannot know, that ttl is zero, so that packet
1998 will not leave this host and route is valid).
1999 Luckily, this hack is good workaround.
2002 fl4->flowi4_oif = dev_out->ifindex;
2006 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2007 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2008 if (!__ip_dev_find(net, fl4->saddr, false))
2014 if (fl4->flowi4_oif) {
2015 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2016 rth = ERR_PTR(-ENODEV);
2017 if (dev_out == NULL)
2020 /* RACE: Check return value of inet_select_addr instead. */
2021 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2022 rth = ERR_PTR(-ENETUNREACH);
2025 if (ipv4_is_local_multicast(fl4->daddr) ||
2026 ipv4_is_lbcast(fl4->daddr)) {
2028 fl4->saddr = inet_select_addr(dev_out, 0,
2033 if (ipv4_is_multicast(fl4->daddr))
2034 fl4->saddr = inet_select_addr(dev_out, 0,
2036 else if (!fl4->daddr)
2037 fl4->saddr = inet_select_addr(dev_out, 0,
2043 fl4->daddr = fl4->saddr;
2045 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2046 dev_out = net->loopback_dev;
2047 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2048 res.type = RTN_LOCAL;
2049 flags |= RTCF_LOCAL;
2053 if (fib_lookup(net, fl4, &res)) {
2056 if (fl4->flowi4_oif) {
2057 /* Apparently, routing tables are wrong. Assume,
2058 that the destination is on link.
2061 Because we are allowed to send to iface
2062 even if it has NO routes and NO assigned
2063 addresses. When oif is specified, routing
2064 tables are looked up with only one purpose:
2065 to catch if destination is gatewayed, rather than
2066 direct. Moreover, if MSG_DONTROUTE is set,
2067 we send packet, ignoring both routing tables
2068 and ifaddr state. --ANK
2071 We could make it even if oif is unknown,
2072 likely IPv6, but we do not.
2075 if (fl4->saddr == 0)
2076 fl4->saddr = inet_select_addr(dev_out, 0,
2078 res.type = RTN_UNICAST;
2081 rth = ERR_PTR(-ENETUNREACH);
2085 if (res.type == RTN_LOCAL) {
2087 if (res.fi->fib_prefsrc)
2088 fl4->saddr = res.fi->fib_prefsrc;
2090 fl4->saddr = fl4->daddr;
2092 dev_out = net->loopback_dev;
2093 fl4->flowi4_oif = dev_out->ifindex;
2094 flags |= RTCF_LOCAL;
2098 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2099 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2100 fib_select_multipath(&res);
2103 if (!res.prefixlen &&
2104 res.table->tb_num_default > 1 &&
2105 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2106 fib_select_default(&res);
2109 fl4->saddr = FIB_RES_PREFSRC(net, res);
2111 dev_out = FIB_RES_DEV(res);
2112 fl4->flowi4_oif = dev_out->ifindex;
2116 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2122 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2124 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2129 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2131 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2133 return mtu ? : dst->dev->mtu;
2136 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2137 struct sk_buff *skb, u32 mtu)
2141 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2142 struct sk_buff *skb)
2146 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2152 static struct dst_ops ipv4_dst_blackhole_ops = {
2154 .protocol = cpu_to_be16(ETH_P_IP),
2155 .check = ipv4_blackhole_dst_check,
2156 .mtu = ipv4_blackhole_mtu,
2157 .default_advmss = ipv4_default_advmss,
2158 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2159 .redirect = ipv4_rt_blackhole_redirect,
2160 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2161 .neigh_lookup = ipv4_neigh_lookup,
2164 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2166 struct rtable *ort = (struct rtable *) dst_orig;
2169 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2171 struct dst_entry *new = &rt->dst;
2174 new->input = dst_discard;
2175 new->output = dst_discard;
2177 new->dev = ort->dst.dev;
2181 rt->rt_is_input = ort->rt_is_input;
2182 rt->rt_iif = ort->rt_iif;
2183 rt->rt_pmtu = ort->rt_pmtu;
2185 rt->rt_genid = rt_genid(net);
2186 rt->rt_flags = ort->rt_flags;
2187 rt->rt_type = ort->rt_type;
2188 rt->rt_gateway = ort->rt_gateway;
2189 rt->rt_uses_gateway = ort->rt_uses_gateway;
2191 INIT_LIST_HEAD(&rt->rt_uncached);
2196 dst_release(dst_orig);
2198 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2201 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2204 struct rtable *rt = __ip_route_output_key(net, flp4);
2209 if (flp4->flowi4_proto)
2210 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2211 flowi4_to_flowi(flp4),
2216 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2218 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2219 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2220 u32 seq, int event, int nowait, unsigned int flags)
2222 struct rtable *rt = skb_rtable(skb);
2224 struct nlmsghdr *nlh;
2225 unsigned long expires = 0;
2227 u32 metrics[RTAX_MAX];
2229 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2233 r = nlmsg_data(nlh);
2234 r->rtm_family = AF_INET;
2235 r->rtm_dst_len = 32;
2237 r->rtm_tos = fl4->flowi4_tos;
2238 r->rtm_table = RT_TABLE_MAIN;
2239 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2240 goto nla_put_failure;
2241 r->rtm_type = rt->rt_type;
2242 r->rtm_scope = RT_SCOPE_UNIVERSE;
2243 r->rtm_protocol = RTPROT_UNSPEC;
2244 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2245 if (rt->rt_flags & RTCF_NOTIFY)
2246 r->rtm_flags |= RTM_F_NOTIFY;
2248 if (nla_put_be32(skb, RTA_DST, dst))
2249 goto nla_put_failure;
2251 r->rtm_src_len = 32;
2252 if (nla_put_be32(skb, RTA_SRC, src))
2253 goto nla_put_failure;
2256 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2257 goto nla_put_failure;
2258 #ifdef CONFIG_IP_ROUTE_CLASSID
2259 if (rt->dst.tclassid &&
2260 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2261 goto nla_put_failure;
2263 if (!rt_is_input_route(rt) &&
2264 fl4->saddr != src) {
2265 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2266 goto nla_put_failure;
2268 if (rt->rt_uses_gateway &&
2269 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2270 goto nla_put_failure;
2272 expires = rt->dst.expires;
2274 unsigned long now = jiffies;
2276 if (time_before(now, expires))
2282 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2283 if (rt->rt_pmtu && expires)
2284 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2285 if (rtnetlink_put_metrics(skb, metrics) < 0)
2286 goto nla_put_failure;
2288 if (fl4->flowi4_mark &&
2289 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2290 goto nla_put_failure;
2292 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
2293 nla_put_u32(skb, RTA_UID,
2294 from_kuid_munged(current_user_ns(), fl4->flowi4_uid)))
2295 goto nla_put_failure;
2297 error = rt->dst.error;
2299 if (rt_is_input_route(rt)) {
2300 #ifdef CONFIG_IP_MROUTE
2301 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2302 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2303 int err = ipmr_get_route(net, skb,
2304 fl4->saddr, fl4->daddr,
2310 goto nla_put_failure;
2312 if (err == -EMSGSIZE)
2313 goto nla_put_failure;
2319 if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
2320 goto nla_put_failure;
2323 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2324 goto nla_put_failure;
2326 return nlmsg_end(skb, nlh);
2329 nlmsg_cancel(skb, nlh);
2333 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2335 struct net *net = sock_net(in_skb->sk);
2337 struct nlattr *tb[RTA_MAX+1];
2338 struct rtable *rt = NULL;
2345 struct sk_buff *skb;
2348 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2352 rtm = nlmsg_data(nlh);
2354 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2360 /* Reserve room for dummy headers, this skb can pass
2361 through good chunk of routing engine.
2363 skb_reset_mac_header(skb);
2364 skb_reset_network_header(skb);
2366 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2367 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2368 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2370 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2371 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2372 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2373 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2375 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
2377 uid = (iif ? INVALID_UID : current_uid());
2379 memset(&fl4, 0, sizeof(fl4));
2382 fl4.flowi4_tos = rtm->rtm_tos;
2383 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2384 fl4.flowi4_mark = mark;
2385 fl4.flowi4_uid = uid;
2388 struct net_device *dev;
2390 dev = __dev_get_by_index(net, iif);
2396 skb->protocol = htons(ETH_P_IP);
2400 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2403 rt = skb_rtable(skb);
2404 if (err == 0 && rt->dst.error)
2405 err = -rt->dst.error;
2407 rt = ip_route_output_key(net, &fl4);
2417 skb_dst_set(skb, &rt->dst);
2418 if (rtm->rtm_flags & RTM_F_NOTIFY)
2419 rt->rt_flags |= RTCF_NOTIFY;
2421 err = rt_fill_info(net, dst, src, &fl4, skb,
2422 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2423 RTM_NEWROUTE, 0, 0);
2427 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2436 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2441 void ip_rt_multicast_event(struct in_device *in_dev)
2443 rt_cache_flush(dev_net(in_dev->dev));
2446 #ifdef CONFIG_SYSCTL
2447 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2448 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2449 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2450 static int ip_rt_gc_elasticity __read_mostly = 8;
2452 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
2453 void __user *buffer,
2454 size_t *lenp, loff_t *ppos)
2457 rt_cache_flush((struct net *)__ctl->extra1);
2464 static ctl_table ipv4_route_table[] = {
2466 .procname = "gc_thresh",
2467 .data = &ipv4_dst_ops.gc_thresh,
2468 .maxlen = sizeof(int),
2470 .proc_handler = proc_dointvec,
2473 .procname = "max_size",
2474 .data = &ip_rt_max_size,
2475 .maxlen = sizeof(int),
2477 .proc_handler = proc_dointvec,
2480 /* Deprecated. Use gc_min_interval_ms */
2482 .procname = "gc_min_interval",
2483 .data = &ip_rt_gc_min_interval,
2484 .maxlen = sizeof(int),
2486 .proc_handler = proc_dointvec_jiffies,
2489 .procname = "gc_min_interval_ms",
2490 .data = &ip_rt_gc_min_interval,
2491 .maxlen = sizeof(int),
2493 .proc_handler = proc_dointvec_ms_jiffies,
2496 .procname = "gc_timeout",
2497 .data = &ip_rt_gc_timeout,
2498 .maxlen = sizeof(int),
2500 .proc_handler = proc_dointvec_jiffies,
2503 .procname = "gc_interval",
2504 .data = &ip_rt_gc_interval,
2505 .maxlen = sizeof(int),
2507 .proc_handler = proc_dointvec_jiffies,
2510 .procname = "redirect_load",
2511 .data = &ip_rt_redirect_load,
2512 .maxlen = sizeof(int),
2514 .proc_handler = proc_dointvec,
2517 .procname = "redirect_number",
2518 .data = &ip_rt_redirect_number,
2519 .maxlen = sizeof(int),
2521 .proc_handler = proc_dointvec,
2524 .procname = "redirect_silence",
2525 .data = &ip_rt_redirect_silence,
2526 .maxlen = sizeof(int),
2528 .proc_handler = proc_dointvec,
2531 .procname = "error_cost",
2532 .data = &ip_rt_error_cost,
2533 .maxlen = sizeof(int),
2535 .proc_handler = proc_dointvec,
2538 .procname = "error_burst",
2539 .data = &ip_rt_error_burst,
2540 .maxlen = sizeof(int),
2542 .proc_handler = proc_dointvec,
2545 .procname = "gc_elasticity",
2546 .data = &ip_rt_gc_elasticity,
2547 .maxlen = sizeof(int),
2549 .proc_handler = proc_dointvec,
2552 .procname = "mtu_expires",
2553 .data = &ip_rt_mtu_expires,
2554 .maxlen = sizeof(int),
2556 .proc_handler = proc_dointvec_jiffies,
2559 .procname = "min_pmtu",
2560 .data = &ip_rt_min_pmtu,
2561 .maxlen = sizeof(int),
2563 .proc_handler = proc_dointvec,
2566 .procname = "min_adv_mss",
2567 .data = &ip_rt_min_advmss,
2568 .maxlen = sizeof(int),
2570 .proc_handler = proc_dointvec,
2575 static struct ctl_table ipv4_route_flush_table[] = {
2577 .procname = "flush",
2578 .maxlen = sizeof(int),
2580 .proc_handler = ipv4_sysctl_rtcache_flush,
2585 static __net_init int sysctl_route_net_init(struct net *net)
2587 struct ctl_table *tbl;
2589 tbl = ipv4_route_flush_table;
2590 if (!net_eq(net, &init_net)) {
2591 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2595 /* Don't export sysctls to unprivileged users */
2596 if (net->user_ns != &init_user_ns)
2597 tbl[0].procname = NULL;
2599 tbl[0].extra1 = net;
2601 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2602 if (net->ipv4.route_hdr == NULL)
2607 if (tbl != ipv4_route_flush_table)
2613 static __net_exit void sysctl_route_net_exit(struct net *net)
2615 struct ctl_table *tbl;
2617 tbl = net->ipv4.route_hdr->ctl_table_arg;
2618 unregister_net_sysctl_table(net->ipv4.route_hdr);
2619 BUG_ON(tbl == ipv4_route_flush_table);
2623 static __net_initdata struct pernet_operations sysctl_route_ops = {
2624 .init = sysctl_route_net_init,
2625 .exit = sysctl_route_net_exit,
2629 static __net_init int rt_genid_init(struct net *net)
2631 atomic_set(&net->rt_genid, 0);
2632 get_random_bytes(&net->ipv4.dev_addr_genid,
2633 sizeof(net->ipv4.dev_addr_genid));
2637 static __net_initdata struct pernet_operations rt_genid_ops = {
2638 .init = rt_genid_init,
2641 static int __net_init ipv4_inetpeer_init(struct net *net)
2643 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2647 inet_peer_base_init(bp);
2648 net->ipv4.peers = bp;
2652 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2654 struct inet_peer_base *bp = net->ipv4.peers;
2656 net->ipv4.peers = NULL;
2657 inetpeer_invalidate_tree(bp);
2661 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2662 .init = ipv4_inetpeer_init,
2663 .exit = ipv4_inetpeer_exit,
2666 #ifdef CONFIG_IP_ROUTE_CLASSID
2667 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2668 #endif /* CONFIG_IP_ROUTE_CLASSID */
2670 int __init ip_rt_init(void)
2674 #ifdef CONFIG_IP_ROUTE_CLASSID
2675 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2677 panic("IP: failed to allocate ip_rt_acct\n");
2680 ipv4_dst_ops.kmem_cachep =
2681 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2682 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2684 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2686 if (dst_entries_init(&ipv4_dst_ops) < 0)
2687 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2689 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2690 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2692 ipv4_dst_ops.gc_thresh = ~0;
2693 ip_rt_max_size = INT_MAX;
2698 if (ip_rt_proc_init())
2699 pr_err("Unable to create route proc files\n");
2704 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2706 #ifdef CONFIG_SYSCTL
2707 register_pernet_subsys(&sysctl_route_ops);
2709 register_pernet_subsys(&rt_genid_ops);
2710 register_pernet_subsys(&ipv4_inetpeer_ops);
2714 #ifdef CONFIG_SYSCTL
2716 * We really need to sanitize the damn ipv4 init order, then all
2717 * this nonsense will go away.
2719 void __init ip_static_sysctl_init(void)
2721 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);