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>
92 #include <linux/jhash.h>
94 #include <net/net_namespace.h>
95 #include <net/protocol.h>
97 #include <net/route.h>
98 #include <net/inetpeer.h>
100 #include <net/ip_fib.h>
103 #include <net/icmp.h>
104 #include <net/xfrm.h>
105 #include <net/netevent.h>
106 #include <net/rtnetlink.h>
108 #include <linux/sysctl.h>
109 #include <linux/kmemleak.h>
111 #include <net/secure_seq.h>
113 #define RT_FL_TOS(oldflp4) \
114 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
116 #define IP_MAX_MTU 0xFFF0
118 #define RT_GC_TIMEOUT (300*HZ)
120 static int ip_rt_max_size;
121 static int ip_rt_redirect_number __read_mostly = 9;
122 static int ip_rt_redirect_load __read_mostly = HZ / 50;
123 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
124 static int ip_rt_error_cost __read_mostly = HZ;
125 static int ip_rt_error_burst __read_mostly = 5 * HZ;
126 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
127 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
128 static int ip_rt_min_advmss __read_mostly = 256;
131 * Interface to generic destination cache.
134 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
135 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
136 static unsigned int ipv4_mtu(const struct dst_entry *dst);
137 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
138 static void ipv4_link_failure(struct sk_buff *skb);
139 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
140 struct sk_buff *skb, u32 mtu);
141 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
142 struct sk_buff *skb);
143 static void ipv4_dst_destroy(struct dst_entry *dst);
145 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
150 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
156 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
160 static struct dst_ops ipv4_dst_ops = {
162 .protocol = cpu_to_be16(ETH_P_IP),
163 .check = ipv4_dst_check,
164 .default_advmss = ipv4_default_advmss,
166 .cow_metrics = ipv4_cow_metrics,
167 .destroy = ipv4_dst_destroy,
168 .ifdown = ipv4_dst_ifdown,
169 .negative_advice = ipv4_negative_advice,
170 .link_failure = ipv4_link_failure,
171 .update_pmtu = ip_rt_update_pmtu,
172 .redirect = ip_do_redirect,
173 .local_out = __ip_local_out,
174 .neigh_lookup = ipv4_neigh_lookup,
177 #define ECN_OR_COST(class) TC_PRIO_##class
179 const __u8 ip_tos2prio[16] = {
181 ECN_OR_COST(BESTEFFORT),
183 ECN_OR_COST(BESTEFFORT),
189 ECN_OR_COST(INTERACTIVE),
191 ECN_OR_COST(INTERACTIVE),
192 TC_PRIO_INTERACTIVE_BULK,
193 ECN_OR_COST(INTERACTIVE_BULK),
194 TC_PRIO_INTERACTIVE_BULK,
195 ECN_OR_COST(INTERACTIVE_BULK)
197 EXPORT_SYMBOL(ip_tos2prio);
199 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
200 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
202 #ifdef CONFIG_PROC_FS
203 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
207 return SEQ_START_TOKEN;
210 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
216 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
220 static int rt_cache_seq_show(struct seq_file *seq, void *v)
222 if (v == SEQ_START_TOKEN)
223 seq_printf(seq, "%-127s\n",
224 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
225 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
230 static const struct seq_operations rt_cache_seq_ops = {
231 .start = rt_cache_seq_start,
232 .next = rt_cache_seq_next,
233 .stop = rt_cache_seq_stop,
234 .show = rt_cache_seq_show,
237 static int rt_cache_seq_open(struct inode *inode, struct file *file)
239 return seq_open(file, &rt_cache_seq_ops);
242 static const struct file_operations rt_cache_seq_fops = {
243 .owner = THIS_MODULE,
244 .open = rt_cache_seq_open,
247 .release = seq_release,
251 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
256 return SEQ_START_TOKEN;
258 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
259 if (!cpu_possible(cpu))
262 return &per_cpu(rt_cache_stat, cpu);
267 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
271 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
272 if (!cpu_possible(cpu))
275 return &per_cpu(rt_cache_stat, cpu);
281 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
286 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
288 struct rt_cache_stat *st = v;
290 if (v == SEQ_START_TOKEN) {
291 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");
295 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
296 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
297 dst_entries_get_slow(&ipv4_dst_ops),
320 static const struct seq_operations rt_cpu_seq_ops = {
321 .start = rt_cpu_seq_start,
322 .next = rt_cpu_seq_next,
323 .stop = rt_cpu_seq_stop,
324 .show = rt_cpu_seq_show,
328 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
330 return seq_open(file, &rt_cpu_seq_ops);
333 static const struct file_operations rt_cpu_seq_fops = {
334 .owner = THIS_MODULE,
335 .open = rt_cpu_seq_open,
338 .release = seq_release,
341 #ifdef CONFIG_IP_ROUTE_CLASSID
342 static int rt_acct_proc_show(struct seq_file *m, void *v)
344 struct ip_rt_acct *dst, *src;
347 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
351 for_each_possible_cpu(i) {
352 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
353 for (j = 0; j < 256; j++) {
354 dst[j].o_bytes += src[j].o_bytes;
355 dst[j].o_packets += src[j].o_packets;
356 dst[j].i_bytes += src[j].i_bytes;
357 dst[j].i_packets += src[j].i_packets;
361 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
366 static int rt_acct_proc_open(struct inode *inode, struct file *file)
368 return single_open(file, rt_acct_proc_show, NULL);
371 static const struct file_operations rt_acct_proc_fops = {
372 .owner = THIS_MODULE,
373 .open = rt_acct_proc_open,
376 .release = single_release,
380 static int __net_init ip_rt_do_proc_init(struct net *net)
382 struct proc_dir_entry *pde;
384 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
389 pde = proc_create("rt_cache", S_IRUGO,
390 net->proc_net_stat, &rt_cpu_seq_fops);
394 #ifdef CONFIG_IP_ROUTE_CLASSID
395 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
401 #ifdef CONFIG_IP_ROUTE_CLASSID
403 remove_proc_entry("rt_cache", net->proc_net_stat);
406 remove_proc_entry("rt_cache", net->proc_net);
411 static void __net_exit ip_rt_do_proc_exit(struct net *net)
413 remove_proc_entry("rt_cache", net->proc_net_stat);
414 remove_proc_entry("rt_cache", net->proc_net);
415 #ifdef CONFIG_IP_ROUTE_CLASSID
416 remove_proc_entry("rt_acct", net->proc_net);
420 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
421 .init = ip_rt_do_proc_init,
422 .exit = ip_rt_do_proc_exit,
425 static int __init ip_rt_proc_init(void)
427 return register_pernet_subsys(&ip_rt_proc_ops);
431 static inline int ip_rt_proc_init(void)
435 #endif /* CONFIG_PROC_FS */
437 static inline bool rt_is_expired(const struct rtable *rth)
439 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
442 void rt_cache_flush(struct net *net)
447 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
451 struct net_device *dev = dst->dev;
452 const __be32 *pkey = daddr;
453 const struct rtable *rt;
456 rt = (const struct rtable *) dst;
458 pkey = (const __be32 *) &rt->rt_gateway;
460 pkey = &ip_hdr(skb)->daddr;
462 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
465 return neigh_create(&arp_tbl, pkey, dev);
468 #define IP_IDENTS_SZ 2048u
469 struct ip_ident_bucket {
474 static struct ip_ident_bucket *ip_idents __read_mostly;
476 /* In order to protect privacy, we add a perturbation to identifiers
477 * if one generator is seldom used. This makes hard for an attacker
478 * to infer how many packets were sent between two points in time.
480 u32 ip_idents_reserve(u32 hash, int segs)
482 struct ip_ident_bucket *bucket = ip_idents + hash % IP_IDENTS_SZ;
483 u32 old = ACCESS_ONCE(bucket->stamp32);
484 u32 now = (u32)jiffies;
487 if (old != now && cmpxchg(&bucket->stamp32, old, now) == old) {
488 u64 x = prandom_u32();
491 delta = (u32)(x >> 32);
494 return atomic_add_return(segs + delta, &bucket->id) - segs;
496 EXPORT_SYMBOL(ip_idents_reserve);
498 void __ip_select_ident(struct iphdr *iph, int segs)
500 static u32 ip_idents_hashrnd __read_mostly;
501 static bool hashrnd_initialized = false;
504 if (unlikely(!hashrnd_initialized)) {
505 hashrnd_initialized = true;
506 get_random_bytes(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
509 hash = jhash_3words((__force u32)iph->daddr,
510 (__force u32)iph->saddr,
513 id = ip_idents_reserve(hash, segs);
516 EXPORT_SYMBOL(__ip_select_ident);
518 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
519 const struct iphdr *iph,
521 u8 prot, u32 mark, int flow_flags)
524 const struct inet_sock *inet = inet_sk(sk);
526 oif = sk->sk_bound_dev_if;
528 tos = RT_CONN_FLAGS(sk);
529 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
531 flowi4_init_output(fl4, oif, mark, tos,
532 RT_SCOPE_UNIVERSE, prot,
534 iph->daddr, iph->saddr, 0, 0);
537 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
538 const struct sock *sk)
540 const struct iphdr *iph = ip_hdr(skb);
541 int oif = skb->dev->ifindex;
542 u8 tos = RT_TOS(iph->tos);
543 u8 prot = iph->protocol;
544 u32 mark = skb->mark;
546 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
549 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
551 const struct inet_sock *inet = inet_sk(sk);
552 const struct ip_options_rcu *inet_opt;
553 __be32 daddr = inet->inet_daddr;
556 inet_opt = rcu_dereference(inet->inet_opt);
557 if (inet_opt && inet_opt->opt.srr)
558 daddr = inet_opt->opt.faddr;
559 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
560 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
561 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
562 inet_sk_flowi_flags(sk),
563 daddr, inet->inet_saddr, 0, 0);
567 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
568 const struct sk_buff *skb)
571 build_skb_flow_key(fl4, skb, sk);
573 build_sk_flow_key(fl4, sk);
576 static inline void rt_free(struct rtable *rt)
578 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
581 static DEFINE_SPINLOCK(fnhe_lock);
583 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
585 struct fib_nh_exception *fnhe, *oldest;
588 oldest = rcu_dereference(hash->chain);
589 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
590 fnhe = rcu_dereference(fnhe->fnhe_next)) {
591 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
594 orig = rcu_dereference(oldest->fnhe_rth);
596 RCU_INIT_POINTER(oldest->fnhe_rth, NULL);
602 static inline u32 fnhe_hashfun(__be32 daddr)
606 hval = (__force u32) daddr;
607 hval ^= (hval >> 11) ^ (hval >> 22);
609 return hval & (FNHE_HASH_SIZE - 1);
612 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
613 u32 pmtu, unsigned long expires)
615 struct fnhe_hash_bucket *hash;
616 struct fib_nh_exception *fnhe;
618 u32 hval = fnhe_hashfun(daddr);
620 spin_lock_bh(&fnhe_lock);
622 hash = nh->nh_exceptions;
624 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
627 nh->nh_exceptions = hash;
633 for (fnhe = rcu_dereference(hash->chain); fnhe;
634 fnhe = rcu_dereference(fnhe->fnhe_next)) {
635 if (fnhe->fnhe_daddr == daddr)
644 fnhe->fnhe_pmtu = pmtu;
645 fnhe->fnhe_expires = expires;
648 if (depth > FNHE_RECLAIM_DEPTH)
649 fnhe = fnhe_oldest(hash);
651 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
655 fnhe->fnhe_next = hash->chain;
656 rcu_assign_pointer(hash->chain, fnhe);
658 fnhe->fnhe_daddr = daddr;
660 fnhe->fnhe_pmtu = pmtu;
661 fnhe->fnhe_expires = expires;
664 fnhe->fnhe_stamp = jiffies;
667 spin_unlock_bh(&fnhe_lock);
671 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
674 __be32 new_gw = icmp_hdr(skb)->un.gateway;
675 __be32 old_gw = ip_hdr(skb)->saddr;
676 struct net_device *dev = skb->dev;
677 struct in_device *in_dev;
678 struct fib_result res;
682 switch (icmp_hdr(skb)->code & 7) {
684 case ICMP_REDIR_NETTOS:
685 case ICMP_REDIR_HOST:
686 case ICMP_REDIR_HOSTTOS:
693 if (rt->rt_gateway != old_gw)
696 in_dev = __in_dev_get_rcu(dev);
701 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
702 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
703 ipv4_is_zeronet(new_gw))
704 goto reject_redirect;
706 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
707 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
708 goto reject_redirect;
709 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
710 goto reject_redirect;
712 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
713 goto reject_redirect;
716 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
718 if (!(n->nud_state & NUD_VALID)) {
719 neigh_event_send(n, NULL);
721 if (fib_lookup(net, fl4, &res) == 0) {
722 struct fib_nh *nh = &FIB_RES_NH(res);
724 update_or_create_fnhe(nh, fl4->daddr, new_gw,
728 rt->dst.obsolete = DST_OBSOLETE_KILL;
729 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
736 #ifdef CONFIG_IP_ROUTE_VERBOSE
737 if (IN_DEV_LOG_MARTIANS(in_dev)) {
738 const struct iphdr *iph = (const struct iphdr *) skb->data;
739 __be32 daddr = iph->daddr;
740 __be32 saddr = iph->saddr;
742 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
743 " Advised path = %pI4 -> %pI4\n",
744 &old_gw, dev->name, &new_gw,
751 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
755 const struct iphdr *iph = (const struct iphdr *) skb->data;
756 int oif = skb->dev->ifindex;
757 u8 tos = RT_TOS(iph->tos);
758 u8 prot = iph->protocol;
759 u32 mark = skb->mark;
761 rt = (struct rtable *) dst;
763 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
764 __ip_do_redirect(rt, skb, &fl4, true);
767 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
769 struct rtable *rt = (struct rtable *)dst;
770 struct dst_entry *ret = dst;
773 if (dst->obsolete > 0) {
776 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
787 * 1. The first ip_rt_redirect_number redirects are sent
788 * with exponential backoff, then we stop sending them at all,
789 * assuming that the host ignores our redirects.
790 * 2. If we did not see packets requiring redirects
791 * during ip_rt_redirect_silence, we assume that the host
792 * forgot redirected route and start to send redirects again.
794 * This algorithm is much cheaper and more intelligent than dumb load limiting
797 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
798 * and "frag. need" (breaks PMTU discovery) in icmp.c.
801 void ip_rt_send_redirect(struct sk_buff *skb)
803 struct rtable *rt = skb_rtable(skb);
804 struct in_device *in_dev;
805 struct inet_peer *peer;
810 in_dev = __in_dev_get_rcu(rt->dst.dev);
811 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
815 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
818 net = dev_net(rt->dst.dev);
819 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
821 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
822 rt_nexthop(rt, ip_hdr(skb)->daddr));
826 /* No redirected packets during ip_rt_redirect_silence;
827 * reset the algorithm.
829 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
830 peer->rate_tokens = 0;
832 /* Too many ignored redirects; do not send anything
833 * set dst.rate_last to the last seen redirected packet.
835 if (peer->rate_tokens >= ip_rt_redirect_number) {
836 peer->rate_last = jiffies;
840 /* Check for load limit; set rate_last to the latest sent
843 if (peer->rate_tokens == 0 ||
846 (ip_rt_redirect_load << peer->rate_tokens)))) {
847 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
849 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
850 peer->rate_last = jiffies;
852 #ifdef CONFIG_IP_ROUTE_VERBOSE
854 peer->rate_tokens == ip_rt_redirect_number)
855 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
856 &ip_hdr(skb)->saddr, inet_iif(skb),
857 &ip_hdr(skb)->daddr, &gw);
864 static int ip_error(struct sk_buff *skb)
866 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
867 struct rtable *rt = skb_rtable(skb);
868 struct inet_peer *peer;
874 net = dev_net(rt->dst.dev);
875 if (!IN_DEV_FORWARD(in_dev)) {
876 switch (rt->dst.error) {
878 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
882 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
888 switch (rt->dst.error) {
893 code = ICMP_HOST_UNREACH;
896 code = ICMP_NET_UNREACH;
897 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
900 code = ICMP_PKT_FILTERED;
904 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
909 peer->rate_tokens += now - peer->rate_last;
910 if (peer->rate_tokens > ip_rt_error_burst)
911 peer->rate_tokens = ip_rt_error_burst;
912 peer->rate_last = now;
913 if (peer->rate_tokens >= ip_rt_error_cost)
914 peer->rate_tokens -= ip_rt_error_cost;
920 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
926 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
928 struct dst_entry *dst = &rt->dst;
929 struct fib_result res;
931 if (dst_metric_locked(dst, RTAX_MTU))
934 if (dst->dev->mtu < mtu)
937 if (mtu < ip_rt_min_pmtu)
938 mtu = ip_rt_min_pmtu;
941 dst->obsolete = DST_OBSOLETE_KILL;
944 dst->expires = max(1UL, jiffies + ip_rt_mtu_expires);
948 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
949 struct fib_nh *nh = &FIB_RES_NH(res);
951 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
952 jiffies + ip_rt_mtu_expires);
957 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
958 struct sk_buff *skb, u32 mtu)
960 struct rtable *rt = (struct rtable *) dst;
963 ip_rt_build_flow_key(&fl4, sk, skb);
964 __ip_rt_update_pmtu(rt, &fl4, mtu);
967 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
968 int oif, u32 mark, u8 protocol, int flow_flags)
970 const struct iphdr *iph = (const struct iphdr *) skb->data;
974 __build_flow_key(&fl4, NULL, iph, oif,
975 RT_TOS(iph->tos), protocol, mark, flow_flags);
976 rt = __ip_route_output_key(net, &fl4);
978 __ip_rt_update_pmtu(rt, &fl4, mtu);
982 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
984 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
986 const struct iphdr *iph = (const struct iphdr *) skb->data;
990 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
991 rt = __ip_route_output_key(sock_net(sk), &fl4);
993 __ip_rt_update_pmtu(rt, &fl4, mtu);
998 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1000 const struct iphdr *iph = (const struct iphdr *) skb->data;
1003 struct dst_entry *odst = NULL;
1007 odst = sk_dst_get(sk);
1009 if (sock_owned_by_user(sk) || !odst) {
1010 __ipv4_sk_update_pmtu(skb, sk, mtu);
1014 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1016 rt = (struct rtable *)odst;
1017 if (odst->obsolete && odst->ops->check(odst, 0) == NULL) {
1018 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1025 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1027 if (!dst_check(&rt->dst, 0)) {
1029 dst_release(&rt->dst);
1031 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1039 sk_dst_set(sk, &rt->dst);
1045 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1047 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1048 int oif, u32 mark, u8 protocol, int flow_flags)
1050 const struct iphdr *iph = (const struct iphdr *) skb->data;
1054 __build_flow_key(&fl4, NULL, iph, oif,
1055 RT_TOS(iph->tos), protocol, mark, flow_flags);
1056 rt = __ip_route_output_key(net, &fl4);
1058 __ip_do_redirect(rt, skb, &fl4, false);
1062 EXPORT_SYMBOL_GPL(ipv4_redirect);
1064 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1066 const struct iphdr *iph = (const struct iphdr *) skb->data;
1070 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1071 rt = __ip_route_output_key(sock_net(sk), &fl4);
1073 __ip_do_redirect(rt, skb, &fl4, false);
1077 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1079 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1081 struct rtable *rt = (struct rtable *) dst;
1083 /* All IPV4 dsts are created with ->obsolete set to the value
1084 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1085 * into this function always.
1087 * When a PMTU/redirect information update invalidates a
1088 * route, this is indicated by setting obsolete to
1089 * DST_OBSOLETE_KILL.
1091 if (dst->obsolete == DST_OBSOLETE_KILL || rt_is_expired(rt))
1096 static void ipv4_link_failure(struct sk_buff *skb)
1100 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1102 rt = skb_rtable(skb);
1104 dst_set_expires(&rt->dst, 0);
1107 static int ip_rt_bug(struct sk_buff *skb)
1109 pr_debug("%s: %pI4 -> %pI4, %s\n",
1110 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1111 skb->dev ? skb->dev->name : "?");
1118 We do not cache source address of outgoing interface,
1119 because it is used only by IP RR, TS and SRR options,
1120 so that it out of fast path.
1122 BTW remember: "addr" is allowed to be not aligned
1126 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1130 if (rt_is_output_route(rt))
1131 src = ip_hdr(skb)->saddr;
1133 struct fib_result res;
1139 memset(&fl4, 0, sizeof(fl4));
1140 fl4.daddr = iph->daddr;
1141 fl4.saddr = iph->saddr;
1142 fl4.flowi4_tos = RT_TOS(iph->tos);
1143 fl4.flowi4_oif = rt->dst.dev->ifindex;
1144 fl4.flowi4_iif = skb->dev->ifindex;
1145 fl4.flowi4_mark = skb->mark;
1148 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1149 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1151 src = inet_select_addr(rt->dst.dev,
1152 rt_nexthop(rt, iph->daddr),
1156 memcpy(addr, &src, 4);
1159 #ifdef CONFIG_IP_ROUTE_CLASSID
1160 static void set_class_tag(struct rtable *rt, u32 tag)
1162 if (!(rt->dst.tclassid & 0xFFFF))
1163 rt->dst.tclassid |= tag & 0xFFFF;
1164 if (!(rt->dst.tclassid & 0xFFFF0000))
1165 rt->dst.tclassid |= tag & 0xFFFF0000;
1169 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1171 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1174 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1176 if (advmss > 65535 - 40)
1177 advmss = 65535 - 40;
1182 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1184 const struct rtable *rt = (const struct rtable *) dst;
1185 unsigned int mtu = rt->rt_pmtu;
1187 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1188 mtu = dst_metric_raw(dst, RTAX_MTU);
1193 mtu = dst->dev->mtu;
1195 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1196 if (rt->rt_uses_gateway && mtu > 576)
1200 if (mtu > IP_MAX_MTU)
1206 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1208 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1209 struct fib_nh_exception *fnhe;
1215 hval = fnhe_hashfun(daddr);
1217 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1218 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1219 if (fnhe->fnhe_daddr == daddr)
1225 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1230 spin_lock_bh(&fnhe_lock);
1232 if (daddr == fnhe->fnhe_daddr) {
1233 struct rtable *orig = rcu_dereference(fnhe->fnhe_rth);
1234 if (orig && rt_is_expired(orig)) {
1236 fnhe->fnhe_pmtu = 0;
1237 fnhe->fnhe_expires = 0;
1239 if (fnhe->fnhe_pmtu) {
1240 unsigned long expires = fnhe->fnhe_expires;
1241 unsigned long diff = expires - jiffies;
1243 if (time_before(jiffies, expires)) {
1244 rt->rt_pmtu = fnhe->fnhe_pmtu;
1245 dst_set_expires(&rt->dst, diff);
1248 if (fnhe->fnhe_gw) {
1249 rt->rt_flags |= RTCF_REDIRECTED;
1250 rt->rt_gateway = fnhe->fnhe_gw;
1251 rt->rt_uses_gateway = 1;
1252 } else if (!rt->rt_gateway)
1253 rt->rt_gateway = daddr;
1255 rcu_assign_pointer(fnhe->fnhe_rth, rt);
1259 fnhe->fnhe_stamp = jiffies;
1262 spin_unlock_bh(&fnhe_lock);
1267 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1269 struct rtable *orig, *prev, **p;
1272 if (rt_is_input_route(rt)) {
1273 p = (struct rtable **)&nh->nh_rth_input;
1275 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1279 prev = cmpxchg(p, orig, rt);
1289 static DEFINE_SPINLOCK(rt_uncached_lock);
1290 static LIST_HEAD(rt_uncached_list);
1292 static void rt_add_uncached_list(struct rtable *rt)
1294 spin_lock_bh(&rt_uncached_lock);
1295 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1296 spin_unlock_bh(&rt_uncached_lock);
1299 static void ipv4_dst_destroy(struct dst_entry *dst)
1301 struct rtable *rt = (struct rtable *) dst;
1303 if (!list_empty(&rt->rt_uncached)) {
1304 spin_lock_bh(&rt_uncached_lock);
1305 list_del(&rt->rt_uncached);
1306 spin_unlock_bh(&rt_uncached_lock);
1310 void rt_flush_dev(struct net_device *dev)
1312 if (!list_empty(&rt_uncached_list)) {
1313 struct net *net = dev_net(dev);
1316 spin_lock_bh(&rt_uncached_lock);
1317 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1318 if (rt->dst.dev != dev)
1320 rt->dst.dev = net->loopback_dev;
1321 dev_hold(rt->dst.dev);
1324 spin_unlock_bh(&rt_uncached_lock);
1328 static bool rt_cache_valid(const struct rtable *rt)
1331 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1335 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1336 const struct fib_result *res,
1337 struct fib_nh_exception *fnhe,
1338 struct fib_info *fi, u16 type, u32 itag)
1340 bool cached = false;
1343 struct fib_nh *nh = &FIB_RES_NH(*res);
1345 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1346 rt->rt_gateway = nh->nh_gw;
1347 rt->rt_uses_gateway = 1;
1349 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1350 #ifdef CONFIG_IP_ROUTE_CLASSID
1351 rt->dst.tclassid = nh->nh_tclassid;
1354 cached = rt_bind_exception(rt, fnhe, daddr);
1355 else if (!(rt->dst.flags & DST_NOCACHE))
1356 cached = rt_cache_route(nh, rt);
1357 if (unlikely(!cached)) {
1358 /* Routes we intend to cache in nexthop exception or
1359 * FIB nexthop have the DST_NOCACHE bit clear.
1360 * However, if we are unsuccessful at storing this
1361 * route into the cache we really need to set it.
1363 rt->dst.flags |= DST_NOCACHE;
1364 if (!rt->rt_gateway)
1365 rt->rt_gateway = daddr;
1366 rt_add_uncached_list(rt);
1369 rt_add_uncached_list(rt);
1371 #ifdef CONFIG_IP_ROUTE_CLASSID
1372 #ifdef CONFIG_IP_MULTIPLE_TABLES
1373 set_class_tag(rt, res->tclassid);
1375 set_class_tag(rt, itag);
1379 static struct rtable *rt_dst_alloc(struct net_device *dev,
1380 bool nopolicy, bool noxfrm, bool will_cache)
1382 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1383 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1384 (nopolicy ? DST_NOPOLICY : 0) |
1385 (noxfrm ? DST_NOXFRM : 0));
1388 /* called in rcu_read_lock() section */
1389 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1390 u8 tos, struct net_device *dev, int our)
1393 struct in_device *in_dev = __in_dev_get_rcu(dev);
1397 /* Primary sanity checks. */
1402 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1403 skb->protocol != htons(ETH_P_IP))
1406 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1407 if (ipv4_is_loopback(saddr))
1410 if (ipv4_is_zeronet(saddr)) {
1411 if (!ipv4_is_local_multicast(daddr))
1414 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1419 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1420 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1424 #ifdef CONFIG_IP_ROUTE_CLASSID
1425 rth->dst.tclassid = itag;
1427 rth->dst.output = ip_rt_bug;
1429 rth->rt_genid = rt_genid(dev_net(dev));
1430 rth->rt_flags = RTCF_MULTICAST;
1431 rth->rt_type = RTN_MULTICAST;
1432 rth->rt_is_input= 1;
1435 rth->rt_gateway = 0;
1436 rth->rt_uses_gateway = 0;
1437 INIT_LIST_HEAD(&rth->rt_uncached);
1439 rth->dst.input= ip_local_deliver;
1440 rth->rt_flags |= RTCF_LOCAL;
1443 #ifdef CONFIG_IP_MROUTE
1444 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1445 rth->dst.input = ip_mr_input;
1447 RT_CACHE_STAT_INC(in_slow_mc);
1449 skb_dst_set(skb, &rth->dst);
1461 static void ip_handle_martian_source(struct net_device *dev,
1462 struct in_device *in_dev,
1463 struct sk_buff *skb,
1467 RT_CACHE_STAT_INC(in_martian_src);
1468 #ifdef CONFIG_IP_ROUTE_VERBOSE
1469 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1471 * RFC1812 recommendation, if source is martian,
1472 * the only hint is MAC header.
1474 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1475 &daddr, &saddr, dev->name);
1476 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1477 print_hex_dump(KERN_WARNING, "ll header: ",
1478 DUMP_PREFIX_OFFSET, 16, 1,
1479 skb_mac_header(skb),
1480 dev->hard_header_len, true);
1486 /* called in rcu_read_lock() section */
1487 static int __mkroute_input(struct sk_buff *skb,
1488 const struct fib_result *res,
1489 struct in_device *in_dev,
1490 __be32 daddr, __be32 saddr, u32 tos)
1494 struct in_device *out_dev;
1495 unsigned int flags = 0;
1499 /* get a working reference to the output device */
1500 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1501 if (out_dev == NULL) {
1502 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1506 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1507 in_dev->dev, in_dev, &itag);
1509 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1515 do_cache = res->fi && !itag;
1516 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1517 skb->protocol == htons(ETH_P_IP) &&
1518 (IN_DEV_SHARED_MEDIA(out_dev) ||
1519 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1520 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1522 if (skb->protocol != htons(ETH_P_IP)) {
1523 /* Not IP (i.e. ARP). Do not create route, if it is
1524 * invalid for proxy arp. DNAT routes are always valid.
1526 * Proxy arp feature have been extended to allow, ARP
1527 * replies back to the same interface, to support
1528 * Private VLAN switch technologies. See arp.c.
1530 if (out_dev == in_dev &&
1531 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1538 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1539 if (rt_cache_valid(rth)) {
1540 skb_dst_set_noref(skb, &rth->dst);
1545 rth = rt_dst_alloc(out_dev->dev,
1546 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1547 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1553 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
1554 rth->rt_flags = flags;
1555 rth->rt_type = res->type;
1556 rth->rt_is_input = 1;
1559 rth->rt_gateway = 0;
1560 rth->rt_uses_gateway = 0;
1561 INIT_LIST_HEAD(&rth->rt_uncached);
1562 RT_CACHE_STAT_INC(in_slow_tot);
1564 rth->dst.input = ip_forward;
1565 rth->dst.output = ip_output;
1567 rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag);
1568 skb_dst_set(skb, &rth->dst);
1575 static int ip_mkroute_input(struct sk_buff *skb,
1576 struct fib_result *res,
1577 const struct flowi4 *fl4,
1578 struct in_device *in_dev,
1579 __be32 daddr, __be32 saddr, u32 tos)
1581 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1582 if (res->fi && res->fi->fib_nhs > 1)
1583 fib_select_multipath(res);
1586 /* create a routing cache entry */
1587 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1591 * NOTE. We drop all the packets that has local source
1592 * addresses, because every properly looped back packet
1593 * must have correct destination already attached by output routine.
1595 * Such approach solves two big problems:
1596 * 1. Not simplex devices are handled properly.
1597 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1598 * called with rcu_read_lock()
1601 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1602 u8 tos, struct net_device *dev)
1604 struct fib_result res;
1605 struct in_device *in_dev = __in_dev_get_rcu(dev);
1607 unsigned int flags = 0;
1611 struct net *net = dev_net(dev);
1614 /* IP on this device is disabled. */
1619 /* Check for the most weird martians, which can be not detected
1623 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1624 goto martian_source;
1627 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1630 /* Accept zero addresses only to limited broadcast;
1631 * I even do not know to fix it or not. Waiting for complains :-)
1633 if (ipv4_is_zeronet(saddr))
1634 goto martian_source;
1636 if (ipv4_is_zeronet(daddr))
1637 goto martian_destination;
1639 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1640 * and call it once if daddr or/and saddr are loopback addresses
1642 if (ipv4_is_loopback(daddr)) {
1643 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1644 goto martian_destination;
1645 } else if (ipv4_is_loopback(saddr)) {
1646 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1647 goto martian_source;
1651 * Now we are ready to route packet.
1654 fl4.flowi4_iif = dev->ifindex;
1655 fl4.flowi4_mark = skb->mark;
1656 fl4.flowi4_tos = tos;
1657 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1660 err = fib_lookup(net, &fl4, &res);
1664 if (res.type == RTN_BROADCAST)
1667 if (res.type == RTN_LOCAL) {
1668 err = fib_validate_source(skb, saddr, daddr, tos,
1670 dev, in_dev, &itag);
1672 goto martian_source_keep_err;
1676 if (!IN_DEV_FORWARD(in_dev))
1678 if (res.type != RTN_UNICAST)
1679 goto martian_destination;
1681 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1685 if (skb->protocol != htons(ETH_P_IP))
1688 if (!ipv4_is_zeronet(saddr)) {
1689 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1692 goto martian_source_keep_err;
1694 flags |= RTCF_BROADCAST;
1695 res.type = RTN_BROADCAST;
1696 RT_CACHE_STAT_INC(in_brd);
1702 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1703 if (rt_cache_valid(rth)) {
1704 skb_dst_set_noref(skb, &rth->dst);
1712 rth = rt_dst_alloc(net->loopback_dev,
1713 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1717 rth->dst.input= ip_local_deliver;
1718 rth->dst.output= ip_rt_bug;
1719 #ifdef CONFIG_IP_ROUTE_CLASSID
1720 rth->dst.tclassid = itag;
1723 rth->rt_genid = rt_genid(net);
1724 rth->rt_flags = flags|RTCF_LOCAL;
1725 rth->rt_type = res.type;
1726 rth->rt_is_input = 1;
1729 rth->rt_gateway = 0;
1730 rth->rt_uses_gateway = 0;
1731 INIT_LIST_HEAD(&rth->rt_uncached);
1732 RT_CACHE_STAT_INC(in_slow_tot);
1733 if (res.type == RTN_UNREACHABLE) {
1734 rth->dst.input= ip_error;
1735 rth->dst.error= -err;
1736 rth->rt_flags &= ~RTCF_LOCAL;
1739 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1740 rth->dst.flags |= DST_NOCACHE;
1741 rt_add_uncached_list(rth);
1744 skb_dst_set(skb, &rth->dst);
1749 RT_CACHE_STAT_INC(in_no_route);
1750 res.type = RTN_UNREACHABLE;
1756 * Do not cache martian addresses: they should be logged (RFC1812)
1758 martian_destination:
1759 RT_CACHE_STAT_INC(in_martian_dst);
1760 #ifdef CONFIG_IP_ROUTE_VERBOSE
1761 if (IN_DEV_LOG_MARTIANS(in_dev))
1762 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1763 &daddr, &saddr, dev->name);
1776 martian_source_keep_err:
1777 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1781 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1782 u8 tos, struct net_device *dev)
1788 /* Multicast recognition logic is moved from route cache to here.
1789 The problem was that too many Ethernet cards have broken/missing
1790 hardware multicast filters :-( As result the host on multicasting
1791 network acquires a lot of useless route cache entries, sort of
1792 SDR messages from all the world. Now we try to get rid of them.
1793 Really, provided software IP multicast filter is organized
1794 reasonably (at least, hashed), it does not result in a slowdown
1795 comparing with route cache reject entries.
1796 Note, that multicast routers are not affected, because
1797 route cache entry is created eventually.
1799 if (ipv4_is_multicast(daddr)) {
1800 struct in_device *in_dev = __in_dev_get_rcu(dev);
1803 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1804 ip_hdr(skb)->protocol);
1806 #ifdef CONFIG_IP_MROUTE
1808 (!ipv4_is_local_multicast(daddr) &&
1809 IN_DEV_MFORWARD(in_dev))
1812 int res = ip_route_input_mc(skb, daddr, saddr,
1821 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1825 EXPORT_SYMBOL(ip_route_input_noref);
1827 /* called with rcu_read_lock() */
1828 static struct rtable *__mkroute_output(const struct fib_result *res,
1829 const struct flowi4 *fl4, int orig_oif,
1830 struct net_device *dev_out,
1833 struct fib_info *fi = res->fi;
1834 struct fib_nh_exception *fnhe;
1835 struct in_device *in_dev;
1836 u16 type = res->type;
1840 in_dev = __in_dev_get_rcu(dev_out);
1842 return ERR_PTR(-EINVAL);
1844 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1845 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1846 return ERR_PTR(-EINVAL);
1848 if (ipv4_is_lbcast(fl4->daddr))
1849 type = RTN_BROADCAST;
1850 else if (ipv4_is_multicast(fl4->daddr))
1851 type = RTN_MULTICAST;
1852 else if (ipv4_is_zeronet(fl4->daddr))
1853 return ERR_PTR(-EINVAL);
1855 if (dev_out->flags & IFF_LOOPBACK)
1856 flags |= RTCF_LOCAL;
1859 if (type == RTN_BROADCAST) {
1860 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1862 } else if (type == RTN_MULTICAST) {
1863 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1864 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1866 flags &= ~RTCF_LOCAL;
1869 /* If multicast route do not exist use
1870 * default one, but do not gateway in this case.
1873 if (fi && res->prefixlen < 4)
1878 do_cache &= fi != NULL;
1880 struct rtable __rcu **prth;
1881 struct fib_nh *nh = &FIB_RES_NH(*res);
1883 fnhe = find_exception(nh, fl4->daddr);
1885 prth = &fnhe->fnhe_rth;
1887 if (unlikely(fl4->flowi4_flags &
1888 FLOWI_FLAG_KNOWN_NH &&
1890 nh->nh_scope == RT_SCOPE_LINK))) {
1894 prth = __this_cpu_ptr(nh->nh_pcpu_rth_output);
1896 rth = rcu_dereference(*prth);
1897 if (rt_cache_valid(rth)) {
1898 dst_hold(&rth->dst);
1904 rth = rt_dst_alloc(dev_out,
1905 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1906 IN_DEV_CONF_GET(in_dev, NOXFRM),
1909 return ERR_PTR(-ENOBUFS);
1911 rth->dst.output = ip_output;
1913 rth->rt_genid = rt_genid(dev_net(dev_out));
1914 rth->rt_flags = flags;
1915 rth->rt_type = type;
1916 rth->rt_is_input = 0;
1917 rth->rt_iif = orig_oif ? : 0;
1919 rth->rt_gateway = 0;
1920 rth->rt_uses_gateway = 0;
1921 INIT_LIST_HEAD(&rth->rt_uncached);
1923 RT_CACHE_STAT_INC(out_slow_tot);
1925 if (flags & RTCF_LOCAL)
1926 rth->dst.input = ip_local_deliver;
1927 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1928 if (flags & RTCF_LOCAL &&
1929 !(dev_out->flags & IFF_LOOPBACK)) {
1930 rth->dst.output = ip_mc_output;
1931 RT_CACHE_STAT_INC(out_slow_mc);
1933 #ifdef CONFIG_IP_MROUTE
1934 if (type == RTN_MULTICAST) {
1935 if (IN_DEV_MFORWARD(in_dev) &&
1936 !ipv4_is_local_multicast(fl4->daddr)) {
1937 rth->dst.input = ip_mr_input;
1938 rth->dst.output = ip_mc_output;
1944 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1950 * Major route resolver routine.
1953 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1955 struct net_device *dev_out = NULL;
1956 __u8 tos = RT_FL_TOS(fl4);
1957 unsigned int flags = 0;
1958 struct fib_result res;
1966 orig_oif = fl4->flowi4_oif;
1968 fl4->flowi4_iif = LOOPBACK_IFINDEX;
1969 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
1970 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
1971 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
1975 rth = ERR_PTR(-EINVAL);
1976 if (ipv4_is_multicast(fl4->saddr) ||
1977 ipv4_is_lbcast(fl4->saddr) ||
1978 ipv4_is_zeronet(fl4->saddr))
1981 /* I removed check for oif == dev_out->oif here.
1982 It was wrong for two reasons:
1983 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
1984 is assigned to multiple interfaces.
1985 2. Moreover, we are allowed to send packets with saddr
1986 of another iface. --ANK
1989 if (fl4->flowi4_oif == 0 &&
1990 (ipv4_is_multicast(fl4->daddr) ||
1991 ipv4_is_lbcast(fl4->daddr))) {
1992 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1993 dev_out = __ip_dev_find(net, fl4->saddr, false);
1994 if (dev_out == NULL)
1997 /* Special hack: user can direct multicasts
1998 and limited broadcast via necessary interface
1999 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2000 This hack is not just for fun, it allows
2001 vic,vat and friends to work.
2002 They bind socket to loopback, set ttl to zero
2003 and expect that it will work.
2004 From the viewpoint of routing cache they are broken,
2005 because we are not allowed to build multicast path
2006 with loopback source addr (look, routing cache
2007 cannot know, that ttl is zero, so that packet
2008 will not leave this host and route is valid).
2009 Luckily, this hack is good workaround.
2012 fl4->flowi4_oif = dev_out->ifindex;
2016 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2017 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2018 if (!__ip_dev_find(net, fl4->saddr, false))
2024 if (fl4->flowi4_oif) {
2025 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2026 rth = ERR_PTR(-ENODEV);
2027 if (dev_out == NULL)
2030 /* RACE: Check return value of inet_select_addr instead. */
2031 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2032 rth = ERR_PTR(-ENETUNREACH);
2035 if (ipv4_is_local_multicast(fl4->daddr) ||
2036 ipv4_is_lbcast(fl4->daddr)) {
2038 fl4->saddr = inet_select_addr(dev_out, 0,
2043 if (ipv4_is_multicast(fl4->daddr))
2044 fl4->saddr = inet_select_addr(dev_out, 0,
2046 else if (!fl4->daddr)
2047 fl4->saddr = inet_select_addr(dev_out, 0,
2053 fl4->daddr = fl4->saddr;
2055 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2056 dev_out = net->loopback_dev;
2057 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2058 res.type = RTN_LOCAL;
2059 flags |= RTCF_LOCAL;
2063 if (fib_lookup(net, fl4, &res)) {
2066 if (fl4->flowi4_oif) {
2067 /* Apparently, routing tables are wrong. Assume,
2068 that the destination is on link.
2071 Because we are allowed to send to iface
2072 even if it has NO routes and NO assigned
2073 addresses. When oif is specified, routing
2074 tables are looked up with only one purpose:
2075 to catch if destination is gatewayed, rather than
2076 direct. Moreover, if MSG_DONTROUTE is set,
2077 we send packet, ignoring both routing tables
2078 and ifaddr state. --ANK
2081 We could make it even if oif is unknown,
2082 likely IPv6, but we do not.
2085 if (fl4->saddr == 0)
2086 fl4->saddr = inet_select_addr(dev_out, 0,
2088 res.type = RTN_UNICAST;
2091 rth = ERR_PTR(-ENETUNREACH);
2095 if (res.type == RTN_LOCAL) {
2097 if (res.fi->fib_prefsrc)
2098 fl4->saddr = res.fi->fib_prefsrc;
2100 fl4->saddr = fl4->daddr;
2102 dev_out = net->loopback_dev;
2103 fl4->flowi4_oif = dev_out->ifindex;
2104 flags |= RTCF_LOCAL;
2108 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2109 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2110 fib_select_multipath(&res);
2113 if (!res.prefixlen &&
2114 res.table->tb_num_default > 1 &&
2115 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2116 fib_select_default(&res);
2119 fl4->saddr = FIB_RES_PREFSRC(net, res);
2121 dev_out = FIB_RES_DEV(res);
2122 fl4->flowi4_oif = dev_out->ifindex;
2126 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2132 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2134 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2139 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2141 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2143 return mtu ? : dst->dev->mtu;
2146 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2147 struct sk_buff *skb, u32 mtu)
2151 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2152 struct sk_buff *skb)
2156 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2162 static struct dst_ops ipv4_dst_blackhole_ops = {
2164 .protocol = cpu_to_be16(ETH_P_IP),
2165 .check = ipv4_blackhole_dst_check,
2166 .mtu = ipv4_blackhole_mtu,
2167 .default_advmss = ipv4_default_advmss,
2168 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2169 .redirect = ipv4_rt_blackhole_redirect,
2170 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2171 .neigh_lookup = ipv4_neigh_lookup,
2174 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2176 struct rtable *ort = (struct rtable *) dst_orig;
2179 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2181 struct dst_entry *new = &rt->dst;
2184 new->input = dst_discard;
2185 new->output = dst_discard;
2187 new->dev = ort->dst.dev;
2191 rt->rt_is_input = ort->rt_is_input;
2192 rt->rt_iif = ort->rt_iif;
2193 rt->rt_pmtu = ort->rt_pmtu;
2195 rt->rt_genid = rt_genid(net);
2196 rt->rt_flags = ort->rt_flags;
2197 rt->rt_type = ort->rt_type;
2198 rt->rt_gateway = ort->rt_gateway;
2199 rt->rt_uses_gateway = ort->rt_uses_gateway;
2201 INIT_LIST_HEAD(&rt->rt_uncached);
2206 dst_release(dst_orig);
2208 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2211 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2214 struct rtable *rt = __ip_route_output_key(net, flp4);
2219 if (flp4->flowi4_proto)
2220 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2221 flowi4_to_flowi(flp4),
2226 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2228 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2229 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2230 u32 seq, int event, int nowait, unsigned int flags)
2232 struct rtable *rt = skb_rtable(skb);
2234 struct nlmsghdr *nlh;
2235 unsigned long expires = 0;
2237 u32 metrics[RTAX_MAX];
2239 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2243 r = nlmsg_data(nlh);
2244 r->rtm_family = AF_INET;
2245 r->rtm_dst_len = 32;
2247 r->rtm_tos = fl4->flowi4_tos;
2248 r->rtm_table = RT_TABLE_MAIN;
2249 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2250 goto nla_put_failure;
2251 r->rtm_type = rt->rt_type;
2252 r->rtm_scope = RT_SCOPE_UNIVERSE;
2253 r->rtm_protocol = RTPROT_UNSPEC;
2254 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2255 if (rt->rt_flags & RTCF_NOTIFY)
2256 r->rtm_flags |= RTM_F_NOTIFY;
2257 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2258 r->rtm_flags |= RTCF_DOREDIRECT;
2260 if (nla_put_be32(skb, RTA_DST, dst))
2261 goto nla_put_failure;
2263 r->rtm_src_len = 32;
2264 if (nla_put_be32(skb, RTA_SRC, src))
2265 goto nla_put_failure;
2268 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2269 goto nla_put_failure;
2270 #ifdef CONFIG_IP_ROUTE_CLASSID
2271 if (rt->dst.tclassid &&
2272 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2273 goto nla_put_failure;
2275 if (!rt_is_input_route(rt) &&
2276 fl4->saddr != src) {
2277 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2278 goto nla_put_failure;
2280 if (rt->rt_uses_gateway &&
2281 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2282 goto nla_put_failure;
2284 expires = rt->dst.expires;
2286 unsigned long now = jiffies;
2288 if (time_before(now, expires))
2294 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2295 if (rt->rt_pmtu && expires)
2296 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2297 if (rtnetlink_put_metrics(skb, metrics) < 0)
2298 goto nla_put_failure;
2300 if (fl4->flowi4_mark &&
2301 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2302 goto nla_put_failure;
2304 error = rt->dst.error;
2306 if (rt_is_input_route(rt)) {
2307 #ifdef CONFIG_IP_MROUTE
2308 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2309 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2310 int err = ipmr_get_route(net, skb,
2311 fl4->saddr, fl4->daddr,
2317 goto nla_put_failure;
2319 if (err == -EMSGSIZE)
2320 goto nla_put_failure;
2326 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2327 goto nla_put_failure;
2330 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2331 goto nla_put_failure;
2333 return nlmsg_end(skb, nlh);
2336 nlmsg_cancel(skb, nlh);
2340 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2342 struct net *net = sock_net(in_skb->sk);
2344 struct nlattr *tb[RTA_MAX+1];
2345 struct rtable *rt = NULL;
2352 struct sk_buff *skb;
2354 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2358 rtm = nlmsg_data(nlh);
2360 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2366 /* Reserve room for dummy headers, this skb can pass
2367 through good chunk of routing engine.
2369 skb_reset_mac_header(skb);
2370 skb_reset_network_header(skb);
2372 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2373 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2374 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2376 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2377 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2378 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2379 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2381 memset(&fl4, 0, sizeof(fl4));
2384 fl4.flowi4_tos = rtm->rtm_tos;
2385 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2386 fl4.flowi4_mark = mark;
2389 struct net_device *dev;
2391 dev = __dev_get_by_index(net, iif);
2397 skb->protocol = htons(ETH_P_IP);
2401 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2404 rt = skb_rtable(skb);
2405 if (err == 0 && rt->dst.error)
2406 err = -rt->dst.error;
2408 rt = ip_route_output_key(net, &fl4);
2418 skb_dst_set(skb, &rt->dst);
2419 if (rtm->rtm_flags & RTM_F_NOTIFY)
2420 rt->rt_flags |= RTCF_NOTIFY;
2422 err = rt_fill_info(net, dst, src, &fl4, skb,
2423 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2424 RTM_NEWROUTE, 0, 0);
2428 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2437 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2442 void ip_rt_multicast_event(struct in_device *in_dev)
2444 rt_cache_flush(dev_net(in_dev->dev));
2447 #ifdef CONFIG_SYSCTL
2448 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2449 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2450 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2451 static int ip_rt_gc_elasticity __read_mostly = 8;
2453 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
2454 void __user *buffer,
2455 size_t *lenp, loff_t *ppos)
2458 rt_cache_flush((struct net *)__ctl->extra1);
2465 static ctl_table ipv4_route_table[] = {
2467 .procname = "gc_thresh",
2468 .data = &ipv4_dst_ops.gc_thresh,
2469 .maxlen = sizeof(int),
2471 .proc_handler = proc_dointvec,
2474 .procname = "max_size",
2475 .data = &ip_rt_max_size,
2476 .maxlen = sizeof(int),
2478 .proc_handler = proc_dointvec,
2481 /* Deprecated. Use gc_min_interval_ms */
2483 .procname = "gc_min_interval",
2484 .data = &ip_rt_gc_min_interval,
2485 .maxlen = sizeof(int),
2487 .proc_handler = proc_dointvec_jiffies,
2490 .procname = "gc_min_interval_ms",
2491 .data = &ip_rt_gc_min_interval,
2492 .maxlen = sizeof(int),
2494 .proc_handler = proc_dointvec_ms_jiffies,
2497 .procname = "gc_timeout",
2498 .data = &ip_rt_gc_timeout,
2499 .maxlen = sizeof(int),
2501 .proc_handler = proc_dointvec_jiffies,
2504 .procname = "gc_interval",
2505 .data = &ip_rt_gc_interval,
2506 .maxlen = sizeof(int),
2508 .proc_handler = proc_dointvec_jiffies,
2511 .procname = "redirect_load",
2512 .data = &ip_rt_redirect_load,
2513 .maxlen = sizeof(int),
2515 .proc_handler = proc_dointvec,
2518 .procname = "redirect_number",
2519 .data = &ip_rt_redirect_number,
2520 .maxlen = sizeof(int),
2522 .proc_handler = proc_dointvec,
2525 .procname = "redirect_silence",
2526 .data = &ip_rt_redirect_silence,
2527 .maxlen = sizeof(int),
2529 .proc_handler = proc_dointvec,
2532 .procname = "error_cost",
2533 .data = &ip_rt_error_cost,
2534 .maxlen = sizeof(int),
2536 .proc_handler = proc_dointvec,
2539 .procname = "error_burst",
2540 .data = &ip_rt_error_burst,
2541 .maxlen = sizeof(int),
2543 .proc_handler = proc_dointvec,
2546 .procname = "gc_elasticity",
2547 .data = &ip_rt_gc_elasticity,
2548 .maxlen = sizeof(int),
2550 .proc_handler = proc_dointvec,
2553 .procname = "mtu_expires",
2554 .data = &ip_rt_mtu_expires,
2555 .maxlen = sizeof(int),
2557 .proc_handler = proc_dointvec_jiffies,
2560 .procname = "min_pmtu",
2561 .data = &ip_rt_min_pmtu,
2562 .maxlen = sizeof(int),
2564 .proc_handler = proc_dointvec,
2567 .procname = "min_adv_mss",
2568 .data = &ip_rt_min_advmss,
2569 .maxlen = sizeof(int),
2571 .proc_handler = proc_dointvec,
2576 static struct ctl_table ipv4_route_flush_table[] = {
2578 .procname = "flush",
2579 .maxlen = sizeof(int),
2581 .proc_handler = ipv4_sysctl_rtcache_flush,
2586 static __net_init int sysctl_route_net_init(struct net *net)
2588 struct ctl_table *tbl;
2590 tbl = ipv4_route_flush_table;
2591 if (!net_eq(net, &init_net)) {
2592 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2596 /* Don't export sysctls to unprivileged users */
2597 if (net->user_ns != &init_user_ns)
2598 tbl[0].procname = NULL;
2600 tbl[0].extra1 = net;
2602 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2603 if (net->ipv4.route_hdr == NULL)
2608 if (tbl != ipv4_route_flush_table)
2614 static __net_exit void sysctl_route_net_exit(struct net *net)
2616 struct ctl_table *tbl;
2618 tbl = net->ipv4.route_hdr->ctl_table_arg;
2619 unregister_net_sysctl_table(net->ipv4.route_hdr);
2620 BUG_ON(tbl == ipv4_route_flush_table);
2624 static __net_initdata struct pernet_operations sysctl_route_ops = {
2625 .init = sysctl_route_net_init,
2626 .exit = sysctl_route_net_exit,
2630 static __net_init int rt_genid_init(struct net *net)
2632 atomic_set(&net->rt_genid, 0);
2633 get_random_bytes(&net->ipv4.dev_addr_genid,
2634 sizeof(net->ipv4.dev_addr_genid));
2638 static __net_initdata struct pernet_operations rt_genid_ops = {
2639 .init = rt_genid_init,
2642 static int __net_init ipv4_inetpeer_init(struct net *net)
2644 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2648 inet_peer_base_init(bp);
2649 net->ipv4.peers = bp;
2653 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2655 struct inet_peer_base *bp = net->ipv4.peers;
2657 net->ipv4.peers = NULL;
2658 inetpeer_invalidate_tree(bp);
2662 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2663 .init = ipv4_inetpeer_init,
2664 .exit = ipv4_inetpeer_exit,
2667 #ifdef CONFIG_IP_ROUTE_CLASSID
2668 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2669 #endif /* CONFIG_IP_ROUTE_CLASSID */
2671 int __init ip_rt_init(void)
2675 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2677 panic("IP: failed to allocate ip_idents\n");
2679 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2681 #ifdef CONFIG_IP_ROUTE_CLASSID
2682 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2684 panic("IP: failed to allocate ip_rt_acct\n");
2687 ipv4_dst_ops.kmem_cachep =
2688 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2689 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2691 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2693 if (dst_entries_init(&ipv4_dst_ops) < 0)
2694 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2696 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2697 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2699 ipv4_dst_ops.gc_thresh = ~0;
2700 ip_rt_max_size = INT_MAX;
2705 if (ip_rt_proc_init())
2706 pr_err("Unable to create route proc files\n");
2711 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2713 #ifdef CONFIG_SYSCTL
2714 register_pernet_subsys(&sysctl_route_ops);
2716 register_pernet_subsys(&rt_genid_ops);
2717 register_pernet_subsys(&ipv4_inetpeer_ops);
2721 #ifdef CONFIG_SYSCTL
2723 * We really need to sanitize the damn ipv4 init order, then all
2724 * this nonsense will go away.
2726 void __init ip_static_sysctl_init(void)
2728 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);