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 RT_GC_TIMEOUT (300*HZ)
118 static int ip_rt_max_size;
119 static int ip_rt_redirect_number __read_mostly = 9;
120 static int ip_rt_redirect_load __read_mostly = HZ / 50;
121 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
122 static int ip_rt_error_cost __read_mostly = HZ;
123 static int ip_rt_error_burst __read_mostly = 5 * HZ;
124 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
125 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
126 static int ip_rt_min_advmss __read_mostly = 256;
129 * Interface to generic destination cache.
132 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
133 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
134 static unsigned int ipv4_mtu(const struct dst_entry *dst);
135 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
136 static void ipv4_link_failure(struct sk_buff *skb);
137 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
138 struct sk_buff *skb, u32 mtu);
139 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
140 struct sk_buff *skb);
141 static void ipv4_dst_destroy(struct dst_entry *dst);
143 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
149 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
153 static struct dst_ops ipv4_dst_ops = {
155 .check = ipv4_dst_check,
156 .default_advmss = ipv4_default_advmss,
158 .cow_metrics = ipv4_cow_metrics,
159 .destroy = ipv4_dst_destroy,
160 .negative_advice = ipv4_negative_advice,
161 .link_failure = ipv4_link_failure,
162 .update_pmtu = ip_rt_update_pmtu,
163 .redirect = ip_do_redirect,
164 .local_out = __ip_local_out,
165 .neigh_lookup = ipv4_neigh_lookup,
168 #define ECN_OR_COST(class) TC_PRIO_##class
170 const __u8 ip_tos2prio[16] = {
172 ECN_OR_COST(BESTEFFORT),
174 ECN_OR_COST(BESTEFFORT),
180 ECN_OR_COST(INTERACTIVE),
182 ECN_OR_COST(INTERACTIVE),
183 TC_PRIO_INTERACTIVE_BULK,
184 ECN_OR_COST(INTERACTIVE_BULK),
185 TC_PRIO_INTERACTIVE_BULK,
186 ECN_OR_COST(INTERACTIVE_BULK)
188 EXPORT_SYMBOL(ip_tos2prio);
190 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
191 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
193 #ifdef CONFIG_PROC_FS
194 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
198 return SEQ_START_TOKEN;
201 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
207 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
211 static int rt_cache_seq_show(struct seq_file *seq, void *v)
213 if (v == SEQ_START_TOKEN)
214 seq_printf(seq, "%-127s\n",
215 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
216 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
221 static const struct seq_operations rt_cache_seq_ops = {
222 .start = rt_cache_seq_start,
223 .next = rt_cache_seq_next,
224 .stop = rt_cache_seq_stop,
225 .show = rt_cache_seq_show,
228 static int rt_cache_seq_open(struct inode *inode, struct file *file)
230 return seq_open(file, &rt_cache_seq_ops);
233 static const struct file_operations rt_cache_seq_fops = {
234 .owner = THIS_MODULE,
235 .open = rt_cache_seq_open,
238 .release = seq_release,
242 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
247 return SEQ_START_TOKEN;
249 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
250 if (!cpu_possible(cpu))
253 return &per_cpu(rt_cache_stat, cpu);
258 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
262 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
263 if (!cpu_possible(cpu))
266 return &per_cpu(rt_cache_stat, cpu);
272 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
277 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
279 struct rt_cache_stat *st = v;
281 if (v == SEQ_START_TOKEN) {
282 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");
286 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
287 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
288 dst_entries_get_slow(&ipv4_dst_ops),
301 0, /* st->gc_total */
302 0, /* st->gc_ignored */
303 0, /* st->gc_goal_miss */
304 0, /* st->gc_dst_overflow */
305 0, /* st->in_hlist_search */
306 0 /* st->out_hlist_search */
311 static const struct seq_operations rt_cpu_seq_ops = {
312 .start = rt_cpu_seq_start,
313 .next = rt_cpu_seq_next,
314 .stop = rt_cpu_seq_stop,
315 .show = rt_cpu_seq_show,
319 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
321 return seq_open(file, &rt_cpu_seq_ops);
324 static const struct file_operations rt_cpu_seq_fops = {
325 .owner = THIS_MODULE,
326 .open = rt_cpu_seq_open,
329 .release = seq_release,
332 #ifdef CONFIG_IP_ROUTE_CLASSID
333 static int rt_acct_proc_show(struct seq_file *m, void *v)
335 struct ip_rt_acct *dst, *src;
338 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
342 for_each_possible_cpu(i) {
343 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
344 for (j = 0; j < 256; j++) {
345 dst[j].o_bytes += src[j].o_bytes;
346 dst[j].o_packets += src[j].o_packets;
347 dst[j].i_bytes += src[j].i_bytes;
348 dst[j].i_packets += src[j].i_packets;
352 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
357 static int rt_acct_proc_open(struct inode *inode, struct file *file)
359 return single_open(file, rt_acct_proc_show, NULL);
362 static const struct file_operations rt_acct_proc_fops = {
363 .owner = THIS_MODULE,
364 .open = rt_acct_proc_open,
367 .release = single_release,
371 static int __net_init ip_rt_do_proc_init(struct net *net)
373 struct proc_dir_entry *pde;
375 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
380 pde = proc_create("rt_cache", S_IRUGO,
381 net->proc_net_stat, &rt_cpu_seq_fops);
385 #ifdef CONFIG_IP_ROUTE_CLASSID
386 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
392 #ifdef CONFIG_IP_ROUTE_CLASSID
394 remove_proc_entry("rt_cache", net->proc_net_stat);
397 remove_proc_entry("rt_cache", net->proc_net);
402 static void __net_exit ip_rt_do_proc_exit(struct net *net)
404 remove_proc_entry("rt_cache", net->proc_net_stat);
405 remove_proc_entry("rt_cache", net->proc_net);
406 #ifdef CONFIG_IP_ROUTE_CLASSID
407 remove_proc_entry("rt_acct", net->proc_net);
411 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
412 .init = ip_rt_do_proc_init,
413 .exit = ip_rt_do_proc_exit,
416 static int __init ip_rt_proc_init(void)
418 return register_pernet_subsys(&ip_rt_proc_ops);
422 static inline int ip_rt_proc_init(void)
426 #endif /* CONFIG_PROC_FS */
428 static inline bool rt_is_expired(const struct rtable *rth)
430 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
433 void rt_cache_flush(struct net *net)
435 rt_genid_bump_ipv4(net);
438 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
442 struct net_device *dev = dst->dev;
443 const __be32 *pkey = daddr;
444 const struct rtable *rt;
447 rt = (const struct rtable *) dst;
449 pkey = (const __be32 *) &rt->rt_gateway;
451 pkey = &ip_hdr(skb)->daddr;
453 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
456 return neigh_create(&arp_tbl, pkey, dev);
459 #define IP_IDENTS_SZ 2048u
460 struct ip_ident_bucket {
465 static struct ip_ident_bucket *ip_idents __read_mostly;
467 /* In order to protect privacy, we add a perturbation to identifiers
468 * if one generator is seldom used. This makes hard for an attacker
469 * to infer how many packets were sent between two points in time.
471 u32 ip_idents_reserve(u32 hash, int segs)
473 struct ip_ident_bucket *bucket = ip_idents + hash % IP_IDENTS_SZ;
474 u32 old = ACCESS_ONCE(bucket->stamp32);
475 u32 now = (u32)jiffies;
478 if (old != now && cmpxchg(&bucket->stamp32, old, now) == old)
479 delta = prandom_u32_max(now - old);
481 return atomic_add_return(segs + delta, &bucket->id) - segs;
483 EXPORT_SYMBOL(ip_idents_reserve);
485 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
487 static u32 ip_idents_hashrnd __read_mostly;
490 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
492 hash = jhash_3words((__force u32)iph->daddr,
493 (__force u32)iph->saddr,
494 iph->protocol ^ net_hash_mix(net),
496 id = ip_idents_reserve(hash, segs);
499 EXPORT_SYMBOL(__ip_select_ident);
501 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
502 const struct iphdr *iph,
504 u8 prot, u32 mark, int flow_flags)
507 const struct inet_sock *inet = inet_sk(sk);
509 oif = sk->sk_bound_dev_if;
511 tos = RT_CONN_FLAGS(sk);
512 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
514 flowi4_init_output(fl4, oif, mark, tos,
515 RT_SCOPE_UNIVERSE, prot,
517 iph->daddr, iph->saddr, 0, 0);
520 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
521 const struct sock *sk)
523 const struct iphdr *iph = ip_hdr(skb);
524 int oif = skb->dev->ifindex;
525 u8 tos = RT_TOS(iph->tos);
526 u8 prot = iph->protocol;
527 u32 mark = skb->mark;
529 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
532 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
534 const struct inet_sock *inet = inet_sk(sk);
535 const struct ip_options_rcu *inet_opt;
536 __be32 daddr = inet->inet_daddr;
539 inet_opt = rcu_dereference(inet->inet_opt);
540 if (inet_opt && inet_opt->opt.srr)
541 daddr = inet_opt->opt.faddr;
542 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
543 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
544 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
545 inet_sk_flowi_flags(sk),
546 daddr, inet->inet_saddr, 0, 0);
550 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
551 const struct sk_buff *skb)
554 build_skb_flow_key(fl4, skb, sk);
556 build_sk_flow_key(fl4, sk);
559 static inline void rt_free(struct rtable *rt)
561 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
564 static DEFINE_SPINLOCK(fnhe_lock);
566 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
570 rt = rcu_dereference(fnhe->fnhe_rth_input);
572 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
575 rt = rcu_dereference(fnhe->fnhe_rth_output);
577 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
582 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
584 struct fib_nh_exception *fnhe, *oldest;
586 oldest = rcu_dereference(hash->chain);
587 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
588 fnhe = rcu_dereference(fnhe->fnhe_next)) {
589 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
592 fnhe_flush_routes(oldest);
596 static inline u32 fnhe_hashfun(__be32 daddr)
598 static u32 fnhe_hashrnd __read_mostly;
601 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
602 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
603 return hash_32(hval, FNHE_HASH_SHIFT);
606 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
608 rt->rt_pmtu = fnhe->fnhe_pmtu;
609 rt->dst.expires = fnhe->fnhe_expires;
612 rt->rt_flags |= RTCF_REDIRECTED;
613 rt->rt_gateway = fnhe->fnhe_gw;
614 rt->rt_uses_gateway = 1;
618 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
619 u32 pmtu, unsigned long expires)
621 struct fnhe_hash_bucket *hash;
622 struct fib_nh_exception *fnhe;
626 u32 hval = fnhe_hashfun(daddr);
628 spin_lock_bh(&fnhe_lock);
630 hash = rcu_dereference(nh->nh_exceptions);
632 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
635 rcu_assign_pointer(nh->nh_exceptions, hash);
641 for (fnhe = rcu_dereference(hash->chain); fnhe;
642 fnhe = rcu_dereference(fnhe->fnhe_next)) {
643 if (fnhe->fnhe_daddr == daddr)
652 fnhe->fnhe_pmtu = pmtu;
653 fnhe->fnhe_expires = max(1UL, expires);
655 /* Update all cached dsts too */
656 rt = rcu_dereference(fnhe->fnhe_rth_input);
658 fill_route_from_fnhe(rt, fnhe);
659 rt = rcu_dereference(fnhe->fnhe_rth_output);
661 fill_route_from_fnhe(rt, fnhe);
663 if (depth > FNHE_RECLAIM_DEPTH)
664 fnhe = fnhe_oldest(hash);
666 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
670 fnhe->fnhe_next = hash->chain;
671 rcu_assign_pointer(hash->chain, fnhe);
673 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
674 fnhe->fnhe_daddr = daddr;
676 fnhe->fnhe_pmtu = pmtu;
677 fnhe->fnhe_expires = expires;
679 /* Exception created; mark the cached routes for the nexthop
680 * stale, so anyone caching it rechecks if this exception
683 rt = rcu_dereference(nh->nh_rth_input);
685 rt->dst.obsolete = DST_OBSOLETE_KILL;
687 for_each_possible_cpu(i) {
688 struct rtable __rcu **prt;
689 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
690 rt = rcu_dereference(*prt);
692 rt->dst.obsolete = DST_OBSOLETE_KILL;
696 fnhe->fnhe_stamp = jiffies;
699 spin_unlock_bh(&fnhe_lock);
702 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
705 __be32 new_gw = icmp_hdr(skb)->un.gateway;
706 __be32 old_gw = ip_hdr(skb)->saddr;
707 struct net_device *dev = skb->dev;
708 struct in_device *in_dev;
709 struct fib_result res;
713 switch (icmp_hdr(skb)->code & 7) {
715 case ICMP_REDIR_NETTOS:
716 case ICMP_REDIR_HOST:
717 case ICMP_REDIR_HOSTTOS:
724 if (rt->rt_gateway != old_gw)
727 in_dev = __in_dev_get_rcu(dev);
732 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
733 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
734 ipv4_is_zeronet(new_gw))
735 goto reject_redirect;
737 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
738 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
739 goto reject_redirect;
740 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
741 goto reject_redirect;
743 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
744 goto reject_redirect;
747 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
749 if (!(n->nud_state & NUD_VALID)) {
750 neigh_event_send(n, NULL);
752 if (fib_lookup(net, fl4, &res) == 0) {
753 struct fib_nh *nh = &FIB_RES_NH(res);
755 update_or_create_fnhe(nh, fl4->daddr, new_gw,
759 rt->dst.obsolete = DST_OBSOLETE_KILL;
760 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
767 #ifdef CONFIG_IP_ROUTE_VERBOSE
768 if (IN_DEV_LOG_MARTIANS(in_dev)) {
769 const struct iphdr *iph = (const struct iphdr *) skb->data;
770 __be32 daddr = iph->daddr;
771 __be32 saddr = iph->saddr;
773 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
774 " Advised path = %pI4 -> %pI4\n",
775 &old_gw, dev->name, &new_gw,
782 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
786 const struct iphdr *iph = (const struct iphdr *) skb->data;
787 int oif = skb->dev->ifindex;
788 u8 tos = RT_TOS(iph->tos);
789 u8 prot = iph->protocol;
790 u32 mark = skb->mark;
792 rt = (struct rtable *) dst;
794 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
795 __ip_do_redirect(rt, skb, &fl4, true);
798 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
800 struct rtable *rt = (struct rtable *)dst;
801 struct dst_entry *ret = dst;
804 if (dst->obsolete > 0) {
807 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
818 * 1. The first ip_rt_redirect_number redirects are sent
819 * with exponential backoff, then we stop sending them at all,
820 * assuming that the host ignores our redirects.
821 * 2. If we did not see packets requiring redirects
822 * during ip_rt_redirect_silence, we assume that the host
823 * forgot redirected route and start to send redirects again.
825 * This algorithm is much cheaper and more intelligent than dumb load limiting
828 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
829 * and "frag. need" (breaks PMTU discovery) in icmp.c.
832 void ip_rt_send_redirect(struct sk_buff *skb)
834 struct rtable *rt = skb_rtable(skb);
835 struct in_device *in_dev;
836 struct inet_peer *peer;
841 in_dev = __in_dev_get_rcu(rt->dst.dev);
842 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
846 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
849 net = dev_net(rt->dst.dev);
850 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
852 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
853 rt_nexthop(rt, ip_hdr(skb)->daddr));
857 /* No redirected packets during ip_rt_redirect_silence;
858 * reset the algorithm.
860 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
861 peer->rate_tokens = 0;
863 /* Too many ignored redirects; do not send anything
864 * set dst.rate_last to the last seen redirected packet.
866 if (peer->rate_tokens >= ip_rt_redirect_number) {
867 peer->rate_last = jiffies;
871 /* Check for load limit; set rate_last to the latest sent
874 if (peer->rate_tokens == 0 ||
877 (ip_rt_redirect_load << peer->rate_tokens)))) {
878 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
880 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
881 peer->rate_last = jiffies;
883 #ifdef CONFIG_IP_ROUTE_VERBOSE
885 peer->rate_tokens == ip_rt_redirect_number)
886 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
887 &ip_hdr(skb)->saddr, inet_iif(skb),
888 &ip_hdr(skb)->daddr, &gw);
895 static int ip_error(struct sk_buff *skb)
897 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
898 struct rtable *rt = skb_rtable(skb);
899 struct inet_peer *peer;
905 net = dev_net(rt->dst.dev);
906 if (!IN_DEV_FORWARD(in_dev)) {
907 switch (rt->dst.error) {
909 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
913 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
919 switch (rt->dst.error) {
924 code = ICMP_HOST_UNREACH;
927 code = ICMP_NET_UNREACH;
928 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
931 code = ICMP_PKT_FILTERED;
935 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
940 peer->rate_tokens += now - peer->rate_last;
941 if (peer->rate_tokens > ip_rt_error_burst)
942 peer->rate_tokens = ip_rt_error_burst;
943 peer->rate_last = now;
944 if (peer->rate_tokens >= ip_rt_error_cost)
945 peer->rate_tokens -= ip_rt_error_cost;
951 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
957 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
959 struct dst_entry *dst = &rt->dst;
960 struct fib_result res;
962 if (dst_metric_locked(dst, RTAX_MTU))
965 if (ipv4_mtu(dst) < mtu)
968 if (mtu < ip_rt_min_pmtu)
969 mtu = ip_rt_min_pmtu;
971 if (rt->rt_pmtu == mtu &&
972 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
976 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
977 struct fib_nh *nh = &FIB_RES_NH(res);
979 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
980 jiffies + ip_rt_mtu_expires);
985 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
986 struct sk_buff *skb, u32 mtu)
988 struct rtable *rt = (struct rtable *) dst;
991 ip_rt_build_flow_key(&fl4, sk, skb);
992 __ip_rt_update_pmtu(rt, &fl4, mtu);
995 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
996 int oif, u32 mark, u8 protocol, int flow_flags)
998 const struct iphdr *iph = (const struct iphdr *) skb->data;
1003 mark = IP4_REPLY_MARK(net, skb->mark);
1005 __build_flow_key(&fl4, NULL, iph, oif,
1006 RT_TOS(iph->tos), protocol, mark, flow_flags);
1007 rt = __ip_route_output_key(net, &fl4);
1009 __ip_rt_update_pmtu(rt, &fl4, mtu);
1013 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1015 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1017 const struct iphdr *iph = (const struct iphdr *) skb->data;
1021 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1023 if (!fl4.flowi4_mark)
1024 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1026 rt = __ip_route_output_key(sock_net(sk), &fl4);
1028 __ip_rt_update_pmtu(rt, &fl4, mtu);
1033 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1035 const struct iphdr *iph = (const struct iphdr *) skb->data;
1038 struct dst_entry *odst = NULL;
1043 if (!ip_sk_accept_pmtu(sk))
1046 odst = sk_dst_get(sk);
1048 if (sock_owned_by_user(sk) || !odst) {
1049 __ipv4_sk_update_pmtu(skb, sk, mtu);
1053 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1055 rt = (struct rtable *)odst;
1056 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1057 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1064 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1066 if (!dst_check(&rt->dst, 0)) {
1068 dst_release(&rt->dst);
1070 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1078 sk_dst_set(sk, &rt->dst);
1084 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1086 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1087 int oif, u32 mark, u8 protocol, int flow_flags)
1089 const struct iphdr *iph = (const struct iphdr *) skb->data;
1093 __build_flow_key(&fl4, NULL, iph, oif,
1094 RT_TOS(iph->tos), protocol, mark, flow_flags);
1095 rt = __ip_route_output_key(net, &fl4);
1097 __ip_do_redirect(rt, skb, &fl4, false);
1101 EXPORT_SYMBOL_GPL(ipv4_redirect);
1103 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1105 const struct iphdr *iph = (const struct iphdr *) skb->data;
1109 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1110 rt = __ip_route_output_key(sock_net(sk), &fl4);
1112 __ip_do_redirect(rt, skb, &fl4, false);
1116 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1118 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1120 struct rtable *rt = (struct rtable *) dst;
1122 /* All IPV4 dsts are created with ->obsolete set to the value
1123 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1124 * into this function always.
1126 * When a PMTU/redirect information update invalidates a route,
1127 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1128 * DST_OBSOLETE_DEAD by dst_free().
1130 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1135 static void ipv4_link_failure(struct sk_buff *skb)
1139 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1141 rt = skb_rtable(skb);
1143 dst_set_expires(&rt->dst, 0);
1146 static int ip_rt_bug(struct sock *sk, struct sk_buff *skb)
1148 pr_debug("%s: %pI4 -> %pI4, %s\n",
1149 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1150 skb->dev ? skb->dev->name : "?");
1157 We do not cache source address of outgoing interface,
1158 because it is used only by IP RR, TS and SRR options,
1159 so that it out of fast path.
1161 BTW remember: "addr" is allowed to be not aligned
1165 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1169 if (rt_is_output_route(rt))
1170 src = ip_hdr(skb)->saddr;
1172 struct fib_result res;
1178 memset(&fl4, 0, sizeof(fl4));
1179 fl4.daddr = iph->daddr;
1180 fl4.saddr = iph->saddr;
1181 fl4.flowi4_tos = RT_TOS(iph->tos);
1182 fl4.flowi4_oif = rt->dst.dev->ifindex;
1183 fl4.flowi4_iif = skb->dev->ifindex;
1184 fl4.flowi4_mark = skb->mark;
1187 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1188 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1190 src = inet_select_addr(rt->dst.dev,
1191 rt_nexthop(rt, iph->daddr),
1195 memcpy(addr, &src, 4);
1198 #ifdef CONFIG_IP_ROUTE_CLASSID
1199 static void set_class_tag(struct rtable *rt, u32 tag)
1201 if (!(rt->dst.tclassid & 0xFFFF))
1202 rt->dst.tclassid |= tag & 0xFFFF;
1203 if (!(rt->dst.tclassid & 0xFFFF0000))
1204 rt->dst.tclassid |= tag & 0xFFFF0000;
1208 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1210 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1213 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1215 if (advmss > 65535 - 40)
1216 advmss = 65535 - 40;
1221 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1223 const struct rtable *rt = (const struct rtable *) dst;
1224 unsigned int mtu = rt->rt_pmtu;
1226 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1227 mtu = dst_metric_raw(dst, RTAX_MTU);
1232 mtu = dst->dev->mtu;
1234 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1235 if (rt->rt_uses_gateway && mtu > 576)
1239 return min_t(unsigned int, mtu, IP_MAX_MTU);
1242 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1244 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1245 struct fib_nh_exception *fnhe;
1251 hval = fnhe_hashfun(daddr);
1253 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1254 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1255 if (fnhe->fnhe_daddr == daddr)
1261 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1266 spin_lock_bh(&fnhe_lock);
1268 if (daddr == fnhe->fnhe_daddr) {
1269 struct rtable __rcu **porig;
1270 struct rtable *orig;
1271 int genid = fnhe_genid(dev_net(rt->dst.dev));
1273 if (rt_is_input_route(rt))
1274 porig = &fnhe->fnhe_rth_input;
1276 porig = &fnhe->fnhe_rth_output;
1277 orig = rcu_dereference(*porig);
1279 if (fnhe->fnhe_genid != genid) {
1280 fnhe->fnhe_genid = genid;
1282 fnhe->fnhe_pmtu = 0;
1283 fnhe->fnhe_expires = 0;
1284 fnhe_flush_routes(fnhe);
1287 fill_route_from_fnhe(rt, fnhe);
1288 if (!rt->rt_gateway)
1289 rt->rt_gateway = daddr;
1291 if (!(rt->dst.flags & DST_NOCACHE)) {
1292 rcu_assign_pointer(*porig, rt);
1298 fnhe->fnhe_stamp = jiffies;
1300 spin_unlock_bh(&fnhe_lock);
1305 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1307 struct rtable *orig, *prev, **p;
1310 if (rt_is_input_route(rt)) {
1311 p = (struct rtable **)&nh->nh_rth_input;
1313 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1317 prev = cmpxchg(p, orig, rt);
1327 struct uncached_list {
1329 struct list_head head;
1332 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1334 static void rt_add_uncached_list(struct rtable *rt)
1336 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1338 rt->rt_uncached_list = ul;
1340 spin_lock_bh(&ul->lock);
1341 list_add_tail(&rt->rt_uncached, &ul->head);
1342 spin_unlock_bh(&ul->lock);
1345 static void ipv4_dst_destroy(struct dst_entry *dst)
1347 struct rtable *rt = (struct rtable *) dst;
1349 if (!list_empty(&rt->rt_uncached)) {
1350 struct uncached_list *ul = rt->rt_uncached_list;
1352 spin_lock_bh(&ul->lock);
1353 list_del(&rt->rt_uncached);
1354 spin_unlock_bh(&ul->lock);
1358 void rt_flush_dev(struct net_device *dev)
1360 struct net *net = dev_net(dev);
1364 for_each_possible_cpu(cpu) {
1365 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1367 spin_lock_bh(&ul->lock);
1368 list_for_each_entry(rt, &ul->head, rt_uncached) {
1369 if (rt->dst.dev != dev)
1371 rt->dst.dev = net->loopback_dev;
1372 dev_hold(rt->dst.dev);
1375 spin_unlock_bh(&ul->lock);
1379 static bool rt_cache_valid(const struct rtable *rt)
1382 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1386 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1387 const struct fib_result *res,
1388 struct fib_nh_exception *fnhe,
1389 struct fib_info *fi, u16 type, u32 itag)
1391 bool cached = false;
1394 struct fib_nh *nh = &FIB_RES_NH(*res);
1396 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1397 rt->rt_gateway = nh->nh_gw;
1398 rt->rt_uses_gateway = 1;
1400 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1401 #ifdef CONFIG_IP_ROUTE_CLASSID
1402 rt->dst.tclassid = nh->nh_tclassid;
1405 cached = rt_bind_exception(rt, fnhe, daddr);
1406 else if (!(rt->dst.flags & DST_NOCACHE))
1407 cached = rt_cache_route(nh, rt);
1408 if (unlikely(!cached)) {
1409 /* Routes we intend to cache in nexthop exception or
1410 * FIB nexthop have the DST_NOCACHE bit clear.
1411 * However, if we are unsuccessful at storing this
1412 * route into the cache we really need to set it.
1414 rt->dst.flags |= DST_NOCACHE;
1415 if (!rt->rt_gateway)
1416 rt->rt_gateway = daddr;
1417 rt_add_uncached_list(rt);
1420 rt_add_uncached_list(rt);
1422 #ifdef CONFIG_IP_ROUTE_CLASSID
1423 #ifdef CONFIG_IP_MULTIPLE_TABLES
1424 set_class_tag(rt, res->tclassid);
1426 set_class_tag(rt, itag);
1430 static struct rtable *rt_dst_alloc(struct net_device *dev,
1431 bool nopolicy, bool noxfrm, bool will_cache)
1433 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1434 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1435 (nopolicy ? DST_NOPOLICY : 0) |
1436 (noxfrm ? DST_NOXFRM : 0));
1439 /* called in rcu_read_lock() section */
1440 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1441 u8 tos, struct net_device *dev, int our)
1444 struct in_device *in_dev = __in_dev_get_rcu(dev);
1448 /* Primary sanity checks. */
1453 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1454 skb->protocol != htons(ETH_P_IP))
1457 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1458 if (ipv4_is_loopback(saddr))
1461 if (ipv4_is_zeronet(saddr)) {
1462 if (!ipv4_is_local_multicast(daddr))
1465 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1470 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1471 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1475 #ifdef CONFIG_IP_ROUTE_CLASSID
1476 rth->dst.tclassid = itag;
1478 rth->dst.output = ip_rt_bug;
1480 rth->rt_genid = rt_genid_ipv4(dev_net(dev));
1481 rth->rt_flags = RTCF_MULTICAST;
1482 rth->rt_type = RTN_MULTICAST;
1483 rth->rt_is_input= 1;
1486 rth->rt_gateway = 0;
1487 rth->rt_uses_gateway = 0;
1488 INIT_LIST_HEAD(&rth->rt_uncached);
1490 rth->dst.input= ip_local_deliver;
1491 rth->rt_flags |= RTCF_LOCAL;
1494 #ifdef CONFIG_IP_MROUTE
1495 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1496 rth->dst.input = ip_mr_input;
1498 RT_CACHE_STAT_INC(in_slow_mc);
1500 skb_dst_set(skb, &rth->dst);
1512 static void ip_handle_martian_source(struct net_device *dev,
1513 struct in_device *in_dev,
1514 struct sk_buff *skb,
1518 RT_CACHE_STAT_INC(in_martian_src);
1519 #ifdef CONFIG_IP_ROUTE_VERBOSE
1520 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1522 * RFC1812 recommendation, if source is martian,
1523 * the only hint is MAC header.
1525 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1526 &daddr, &saddr, dev->name);
1527 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1528 print_hex_dump(KERN_WARNING, "ll header: ",
1529 DUMP_PREFIX_OFFSET, 16, 1,
1530 skb_mac_header(skb),
1531 dev->hard_header_len, true);
1537 /* called in rcu_read_lock() section */
1538 static int __mkroute_input(struct sk_buff *skb,
1539 const struct fib_result *res,
1540 struct in_device *in_dev,
1541 __be32 daddr, __be32 saddr, u32 tos)
1543 struct fib_nh_exception *fnhe;
1546 struct in_device *out_dev;
1547 unsigned int flags = 0;
1551 /* get a working reference to the output device */
1552 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1554 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1558 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1559 in_dev->dev, in_dev, &itag);
1561 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1567 do_cache = res->fi && !itag;
1568 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1569 skb->protocol == htons(ETH_P_IP) &&
1570 (IN_DEV_SHARED_MEDIA(out_dev) ||
1571 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1572 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1574 if (skb->protocol != htons(ETH_P_IP)) {
1575 /* Not IP (i.e. ARP). Do not create route, if it is
1576 * invalid for proxy arp. DNAT routes are always valid.
1578 * Proxy arp feature have been extended to allow, ARP
1579 * replies back to the same interface, to support
1580 * Private VLAN switch technologies. See arp.c.
1582 if (out_dev == in_dev &&
1583 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1589 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1592 rth = rcu_dereference(fnhe->fnhe_rth_input);
1594 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1596 if (rt_cache_valid(rth)) {
1597 skb_dst_set_noref(skb, &rth->dst);
1602 rth = rt_dst_alloc(out_dev->dev,
1603 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1604 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1610 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev));
1611 rth->rt_flags = flags;
1612 rth->rt_type = res->type;
1613 rth->rt_is_input = 1;
1616 rth->rt_gateway = 0;
1617 rth->rt_uses_gateway = 0;
1618 INIT_LIST_HEAD(&rth->rt_uncached);
1619 RT_CACHE_STAT_INC(in_slow_tot);
1621 rth->dst.input = ip_forward;
1622 rth->dst.output = ip_output;
1624 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1625 skb_dst_set(skb, &rth->dst);
1632 static int ip_mkroute_input(struct sk_buff *skb,
1633 struct fib_result *res,
1634 const struct flowi4 *fl4,
1635 struct in_device *in_dev,
1636 __be32 daddr, __be32 saddr, u32 tos)
1638 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1639 if (res->fi && res->fi->fib_nhs > 1)
1640 fib_select_multipath(res);
1643 /* create a routing cache entry */
1644 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1648 * NOTE. We drop all the packets that has local source
1649 * addresses, because every properly looped back packet
1650 * must have correct destination already attached by output routine.
1652 * Such approach solves two big problems:
1653 * 1. Not simplex devices are handled properly.
1654 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1655 * called with rcu_read_lock()
1658 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1659 u8 tos, struct net_device *dev)
1661 struct fib_result res;
1662 struct in_device *in_dev = __in_dev_get_rcu(dev);
1664 unsigned int flags = 0;
1668 struct net *net = dev_net(dev);
1671 /* IP on this device is disabled. */
1676 /* Check for the most weird martians, which can be not detected
1680 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1681 goto martian_source;
1684 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1687 /* Accept zero addresses only to limited broadcast;
1688 * I even do not know to fix it or not. Waiting for complains :-)
1690 if (ipv4_is_zeronet(saddr))
1691 goto martian_source;
1693 if (ipv4_is_zeronet(daddr))
1694 goto martian_destination;
1696 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1697 * and call it once if daddr or/and saddr are loopback addresses
1699 if (ipv4_is_loopback(daddr)) {
1700 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1701 goto martian_destination;
1702 } else if (ipv4_is_loopback(saddr)) {
1703 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1704 goto martian_source;
1708 * Now we are ready to route packet.
1711 fl4.flowi4_iif = dev->ifindex;
1712 fl4.flowi4_mark = skb->mark;
1713 fl4.flowi4_tos = tos;
1714 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1717 err = fib_lookup(net, &fl4, &res);
1719 if (!IN_DEV_FORWARD(in_dev))
1720 err = -EHOSTUNREACH;
1724 if (res.type == RTN_BROADCAST)
1727 if (res.type == RTN_LOCAL) {
1728 err = fib_validate_source(skb, saddr, daddr, tos,
1729 0, dev, in_dev, &itag);
1731 goto martian_source_keep_err;
1735 if (!IN_DEV_FORWARD(in_dev)) {
1736 err = -EHOSTUNREACH;
1739 if (res.type != RTN_UNICAST)
1740 goto martian_destination;
1742 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1746 if (skb->protocol != htons(ETH_P_IP))
1749 if (!ipv4_is_zeronet(saddr)) {
1750 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1753 goto martian_source_keep_err;
1755 flags |= RTCF_BROADCAST;
1756 res.type = RTN_BROADCAST;
1757 RT_CACHE_STAT_INC(in_brd);
1763 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1764 if (rt_cache_valid(rth)) {
1765 skb_dst_set_noref(skb, &rth->dst);
1773 rth = rt_dst_alloc(net->loopback_dev,
1774 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1778 rth->dst.input= ip_local_deliver;
1779 rth->dst.output= ip_rt_bug;
1780 #ifdef CONFIG_IP_ROUTE_CLASSID
1781 rth->dst.tclassid = itag;
1784 rth->rt_genid = rt_genid_ipv4(net);
1785 rth->rt_flags = flags|RTCF_LOCAL;
1786 rth->rt_type = res.type;
1787 rth->rt_is_input = 1;
1790 rth->rt_gateway = 0;
1791 rth->rt_uses_gateway = 0;
1792 INIT_LIST_HEAD(&rth->rt_uncached);
1793 RT_CACHE_STAT_INC(in_slow_tot);
1794 if (res.type == RTN_UNREACHABLE) {
1795 rth->dst.input= ip_error;
1796 rth->dst.error= -err;
1797 rth->rt_flags &= ~RTCF_LOCAL;
1800 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1801 rth->dst.flags |= DST_NOCACHE;
1802 rt_add_uncached_list(rth);
1805 skb_dst_set(skb, &rth->dst);
1810 RT_CACHE_STAT_INC(in_no_route);
1811 res.type = RTN_UNREACHABLE;
1816 * Do not cache martian addresses: they should be logged (RFC1812)
1818 martian_destination:
1819 RT_CACHE_STAT_INC(in_martian_dst);
1820 #ifdef CONFIG_IP_ROUTE_VERBOSE
1821 if (IN_DEV_LOG_MARTIANS(in_dev))
1822 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1823 &daddr, &saddr, dev->name);
1836 martian_source_keep_err:
1837 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1841 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1842 u8 tos, struct net_device *dev)
1848 /* Multicast recognition logic is moved from route cache to here.
1849 The problem was that too many Ethernet cards have broken/missing
1850 hardware multicast filters :-( As result the host on multicasting
1851 network acquires a lot of useless route cache entries, sort of
1852 SDR messages from all the world. Now we try to get rid of them.
1853 Really, provided software IP multicast filter is organized
1854 reasonably (at least, hashed), it does not result in a slowdown
1855 comparing with route cache reject entries.
1856 Note, that multicast routers are not affected, because
1857 route cache entry is created eventually.
1859 if (ipv4_is_multicast(daddr)) {
1860 struct in_device *in_dev = __in_dev_get_rcu(dev);
1863 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1864 ip_hdr(skb)->protocol);
1866 #ifdef CONFIG_IP_MROUTE
1868 (!ipv4_is_local_multicast(daddr) &&
1869 IN_DEV_MFORWARD(in_dev))
1872 int res = ip_route_input_mc(skb, daddr, saddr,
1881 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1885 EXPORT_SYMBOL(ip_route_input_noref);
1887 /* called with rcu_read_lock() */
1888 static struct rtable *__mkroute_output(const struct fib_result *res,
1889 const struct flowi4 *fl4, int orig_oif,
1890 struct net_device *dev_out,
1893 struct fib_info *fi = res->fi;
1894 struct fib_nh_exception *fnhe;
1895 struct in_device *in_dev;
1896 u16 type = res->type;
1900 in_dev = __in_dev_get_rcu(dev_out);
1902 return ERR_PTR(-EINVAL);
1904 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1905 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1906 return ERR_PTR(-EINVAL);
1908 if (ipv4_is_lbcast(fl4->daddr))
1909 type = RTN_BROADCAST;
1910 else if (ipv4_is_multicast(fl4->daddr))
1911 type = RTN_MULTICAST;
1912 else if (ipv4_is_zeronet(fl4->daddr))
1913 return ERR_PTR(-EINVAL);
1915 if (dev_out->flags & IFF_LOOPBACK)
1916 flags |= RTCF_LOCAL;
1919 if (type == RTN_BROADCAST) {
1920 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1922 } else if (type == RTN_MULTICAST) {
1923 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1924 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1926 flags &= ~RTCF_LOCAL;
1929 /* If multicast route do not exist use
1930 * default one, but do not gateway in this case.
1933 if (fi && res->prefixlen < 4)
1938 do_cache &= fi != NULL;
1940 struct rtable __rcu **prth;
1941 struct fib_nh *nh = &FIB_RES_NH(*res);
1943 fnhe = find_exception(nh, fl4->daddr);
1945 prth = &fnhe->fnhe_rth_output;
1947 if (unlikely(fl4->flowi4_flags &
1948 FLOWI_FLAG_KNOWN_NH &&
1950 nh->nh_scope == RT_SCOPE_LINK))) {
1954 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
1956 rth = rcu_dereference(*prth);
1957 if (rt_cache_valid(rth)) {
1958 dst_hold(&rth->dst);
1964 rth = rt_dst_alloc(dev_out,
1965 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1966 IN_DEV_CONF_GET(in_dev, NOXFRM),
1969 return ERR_PTR(-ENOBUFS);
1971 rth->dst.output = ip_output;
1973 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out));
1974 rth->rt_flags = flags;
1975 rth->rt_type = type;
1976 rth->rt_is_input = 0;
1977 rth->rt_iif = orig_oif ? : 0;
1979 rth->rt_gateway = 0;
1980 rth->rt_uses_gateway = 0;
1981 INIT_LIST_HEAD(&rth->rt_uncached);
1983 RT_CACHE_STAT_INC(out_slow_tot);
1985 if (flags & RTCF_LOCAL)
1986 rth->dst.input = ip_local_deliver;
1987 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1988 if (flags & RTCF_LOCAL &&
1989 !(dev_out->flags & IFF_LOOPBACK)) {
1990 rth->dst.output = ip_mc_output;
1991 RT_CACHE_STAT_INC(out_slow_mc);
1993 #ifdef CONFIG_IP_MROUTE
1994 if (type == RTN_MULTICAST) {
1995 if (IN_DEV_MFORWARD(in_dev) &&
1996 !ipv4_is_local_multicast(fl4->daddr)) {
1997 rth->dst.input = ip_mr_input;
1998 rth->dst.output = ip_mc_output;
2004 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
2010 * Major route resolver routine.
2013 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
2015 struct net_device *dev_out = NULL;
2016 __u8 tos = RT_FL_TOS(fl4);
2017 unsigned int flags = 0;
2018 struct fib_result res;
2026 orig_oif = fl4->flowi4_oif;
2028 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2029 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2030 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2031 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2035 rth = ERR_PTR(-EINVAL);
2036 if (ipv4_is_multicast(fl4->saddr) ||
2037 ipv4_is_lbcast(fl4->saddr) ||
2038 ipv4_is_zeronet(fl4->saddr))
2041 /* I removed check for oif == dev_out->oif here.
2042 It was wrong for two reasons:
2043 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2044 is assigned to multiple interfaces.
2045 2. Moreover, we are allowed to send packets with saddr
2046 of another iface. --ANK
2049 if (fl4->flowi4_oif == 0 &&
2050 (ipv4_is_multicast(fl4->daddr) ||
2051 ipv4_is_lbcast(fl4->daddr))) {
2052 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2053 dev_out = __ip_dev_find(net, fl4->saddr, false);
2057 /* Special hack: user can direct multicasts
2058 and limited broadcast via necessary interface
2059 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2060 This hack is not just for fun, it allows
2061 vic,vat and friends to work.
2062 They bind socket to loopback, set ttl to zero
2063 and expect that it will work.
2064 From the viewpoint of routing cache they are broken,
2065 because we are not allowed to build multicast path
2066 with loopback source addr (look, routing cache
2067 cannot know, that ttl is zero, so that packet
2068 will not leave this host and route is valid).
2069 Luckily, this hack is good workaround.
2072 fl4->flowi4_oif = dev_out->ifindex;
2076 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2077 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2078 if (!__ip_dev_find(net, fl4->saddr, false))
2084 if (fl4->flowi4_oif) {
2085 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2086 rth = ERR_PTR(-ENODEV);
2090 /* RACE: Check return value of inet_select_addr instead. */
2091 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2092 rth = ERR_PTR(-ENETUNREACH);
2095 if (ipv4_is_local_multicast(fl4->daddr) ||
2096 ipv4_is_lbcast(fl4->daddr)) {
2098 fl4->saddr = inet_select_addr(dev_out, 0,
2103 if (ipv4_is_multicast(fl4->daddr))
2104 fl4->saddr = inet_select_addr(dev_out, 0,
2106 else if (!fl4->daddr)
2107 fl4->saddr = inet_select_addr(dev_out, 0,
2113 fl4->daddr = fl4->saddr;
2115 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2116 dev_out = net->loopback_dev;
2117 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2118 res.type = RTN_LOCAL;
2119 flags |= RTCF_LOCAL;
2123 if (fib_lookup(net, fl4, &res)) {
2126 if (fl4->flowi4_oif) {
2127 /* Apparently, routing tables are wrong. Assume,
2128 that the destination is on link.
2131 Because we are allowed to send to iface
2132 even if it has NO routes and NO assigned
2133 addresses. When oif is specified, routing
2134 tables are looked up with only one purpose:
2135 to catch if destination is gatewayed, rather than
2136 direct. Moreover, if MSG_DONTROUTE is set,
2137 we send packet, ignoring both routing tables
2138 and ifaddr state. --ANK
2141 We could make it even if oif is unknown,
2142 likely IPv6, but we do not.
2145 if (fl4->saddr == 0)
2146 fl4->saddr = inet_select_addr(dev_out, 0,
2148 res.type = RTN_UNICAST;
2151 rth = ERR_PTR(-ENETUNREACH);
2155 if (res.type == RTN_LOCAL) {
2157 if (res.fi->fib_prefsrc)
2158 fl4->saddr = res.fi->fib_prefsrc;
2160 fl4->saddr = fl4->daddr;
2162 dev_out = net->loopback_dev;
2163 fl4->flowi4_oif = dev_out->ifindex;
2164 flags |= RTCF_LOCAL;
2168 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2169 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2170 fib_select_multipath(&res);
2173 if (!res.prefixlen &&
2174 res.table->tb_num_default > 1 &&
2175 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2176 fib_select_default(&res);
2179 fl4->saddr = FIB_RES_PREFSRC(net, res);
2181 dev_out = FIB_RES_DEV(res);
2182 fl4->flowi4_oif = dev_out->ifindex;
2186 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2192 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2194 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2199 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2201 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2203 return mtu ? : dst->dev->mtu;
2206 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2207 struct sk_buff *skb, u32 mtu)
2211 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2212 struct sk_buff *skb)
2216 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2222 static struct dst_ops ipv4_dst_blackhole_ops = {
2224 .check = ipv4_blackhole_dst_check,
2225 .mtu = ipv4_blackhole_mtu,
2226 .default_advmss = ipv4_default_advmss,
2227 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2228 .redirect = ipv4_rt_blackhole_redirect,
2229 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2230 .neigh_lookup = ipv4_neigh_lookup,
2233 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2235 struct rtable *ort = (struct rtable *) dst_orig;
2238 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2240 struct dst_entry *new = &rt->dst;
2243 new->input = dst_discard;
2244 new->output = dst_discard_sk;
2246 new->dev = ort->dst.dev;
2250 rt->rt_is_input = ort->rt_is_input;
2251 rt->rt_iif = ort->rt_iif;
2252 rt->rt_pmtu = ort->rt_pmtu;
2254 rt->rt_genid = rt_genid_ipv4(net);
2255 rt->rt_flags = ort->rt_flags;
2256 rt->rt_type = ort->rt_type;
2257 rt->rt_gateway = ort->rt_gateway;
2258 rt->rt_uses_gateway = ort->rt_uses_gateway;
2260 INIT_LIST_HEAD(&rt->rt_uncached);
2265 dst_release(dst_orig);
2267 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2270 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2273 struct rtable *rt = __ip_route_output_key(net, flp4);
2278 if (flp4->flowi4_proto)
2279 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2280 flowi4_to_flowi(flp4),
2285 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2287 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2288 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2289 u32 seq, int event, int nowait, unsigned int flags)
2291 struct rtable *rt = skb_rtable(skb);
2293 struct nlmsghdr *nlh;
2294 unsigned long expires = 0;
2296 u32 metrics[RTAX_MAX];
2298 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2302 r = nlmsg_data(nlh);
2303 r->rtm_family = AF_INET;
2304 r->rtm_dst_len = 32;
2306 r->rtm_tos = fl4->flowi4_tos;
2307 r->rtm_table = RT_TABLE_MAIN;
2308 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2309 goto nla_put_failure;
2310 r->rtm_type = rt->rt_type;
2311 r->rtm_scope = RT_SCOPE_UNIVERSE;
2312 r->rtm_protocol = RTPROT_UNSPEC;
2313 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2314 if (rt->rt_flags & RTCF_NOTIFY)
2315 r->rtm_flags |= RTM_F_NOTIFY;
2316 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2317 r->rtm_flags |= RTCF_DOREDIRECT;
2319 if (nla_put_in_addr(skb, RTA_DST, dst))
2320 goto nla_put_failure;
2322 r->rtm_src_len = 32;
2323 if (nla_put_in_addr(skb, RTA_SRC, src))
2324 goto nla_put_failure;
2327 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2328 goto nla_put_failure;
2329 #ifdef CONFIG_IP_ROUTE_CLASSID
2330 if (rt->dst.tclassid &&
2331 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2332 goto nla_put_failure;
2334 if (!rt_is_input_route(rt) &&
2335 fl4->saddr != src) {
2336 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2337 goto nla_put_failure;
2339 if (rt->rt_uses_gateway &&
2340 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2341 goto nla_put_failure;
2343 expires = rt->dst.expires;
2345 unsigned long now = jiffies;
2347 if (time_before(now, expires))
2353 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2354 if (rt->rt_pmtu && expires)
2355 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2356 if (rtnetlink_put_metrics(skb, metrics) < 0)
2357 goto nla_put_failure;
2359 if (fl4->flowi4_mark &&
2360 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2361 goto nla_put_failure;
2363 error = rt->dst.error;
2365 if (rt_is_input_route(rt)) {
2366 #ifdef CONFIG_IP_MROUTE
2367 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2368 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2369 int err = ipmr_get_route(net, skb,
2370 fl4->saddr, fl4->daddr,
2376 goto nla_put_failure;
2378 if (err == -EMSGSIZE)
2379 goto nla_put_failure;
2385 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2386 goto nla_put_failure;
2389 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2390 goto nla_put_failure;
2392 nlmsg_end(skb, nlh);
2396 nlmsg_cancel(skb, nlh);
2400 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2402 struct net *net = sock_net(in_skb->sk);
2404 struct nlattr *tb[RTA_MAX+1];
2405 struct rtable *rt = NULL;
2412 struct sk_buff *skb;
2414 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2418 rtm = nlmsg_data(nlh);
2420 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2426 /* Reserve room for dummy headers, this skb can pass
2427 through good chunk of routing engine.
2429 skb_reset_mac_header(skb);
2430 skb_reset_network_header(skb);
2432 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2433 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2434 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2436 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2437 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2438 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2439 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2441 memset(&fl4, 0, sizeof(fl4));
2444 fl4.flowi4_tos = rtm->rtm_tos;
2445 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2446 fl4.flowi4_mark = mark;
2449 struct net_device *dev;
2451 dev = __dev_get_by_index(net, iif);
2457 skb->protocol = htons(ETH_P_IP);
2461 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2464 rt = skb_rtable(skb);
2465 if (err == 0 && rt->dst.error)
2466 err = -rt->dst.error;
2468 rt = ip_route_output_key(net, &fl4);
2478 skb_dst_set(skb, &rt->dst);
2479 if (rtm->rtm_flags & RTM_F_NOTIFY)
2480 rt->rt_flags |= RTCF_NOTIFY;
2482 err = rt_fill_info(net, dst, src, &fl4, skb,
2483 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2484 RTM_NEWROUTE, 0, 0);
2488 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2497 void ip_rt_multicast_event(struct in_device *in_dev)
2499 rt_cache_flush(dev_net(in_dev->dev));
2502 #ifdef CONFIG_SYSCTL
2503 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2504 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2505 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2506 static int ip_rt_gc_elasticity __read_mostly = 8;
2508 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2509 void __user *buffer,
2510 size_t *lenp, loff_t *ppos)
2512 struct net *net = (struct net *)__ctl->extra1;
2515 rt_cache_flush(net);
2516 fnhe_genid_bump(net);
2523 static struct ctl_table ipv4_route_table[] = {
2525 .procname = "gc_thresh",
2526 .data = &ipv4_dst_ops.gc_thresh,
2527 .maxlen = sizeof(int),
2529 .proc_handler = proc_dointvec,
2532 .procname = "max_size",
2533 .data = &ip_rt_max_size,
2534 .maxlen = sizeof(int),
2536 .proc_handler = proc_dointvec,
2539 /* Deprecated. Use gc_min_interval_ms */
2541 .procname = "gc_min_interval",
2542 .data = &ip_rt_gc_min_interval,
2543 .maxlen = sizeof(int),
2545 .proc_handler = proc_dointvec_jiffies,
2548 .procname = "gc_min_interval_ms",
2549 .data = &ip_rt_gc_min_interval,
2550 .maxlen = sizeof(int),
2552 .proc_handler = proc_dointvec_ms_jiffies,
2555 .procname = "gc_timeout",
2556 .data = &ip_rt_gc_timeout,
2557 .maxlen = sizeof(int),
2559 .proc_handler = proc_dointvec_jiffies,
2562 .procname = "gc_interval",
2563 .data = &ip_rt_gc_interval,
2564 .maxlen = sizeof(int),
2566 .proc_handler = proc_dointvec_jiffies,
2569 .procname = "redirect_load",
2570 .data = &ip_rt_redirect_load,
2571 .maxlen = sizeof(int),
2573 .proc_handler = proc_dointvec,
2576 .procname = "redirect_number",
2577 .data = &ip_rt_redirect_number,
2578 .maxlen = sizeof(int),
2580 .proc_handler = proc_dointvec,
2583 .procname = "redirect_silence",
2584 .data = &ip_rt_redirect_silence,
2585 .maxlen = sizeof(int),
2587 .proc_handler = proc_dointvec,
2590 .procname = "error_cost",
2591 .data = &ip_rt_error_cost,
2592 .maxlen = sizeof(int),
2594 .proc_handler = proc_dointvec,
2597 .procname = "error_burst",
2598 .data = &ip_rt_error_burst,
2599 .maxlen = sizeof(int),
2601 .proc_handler = proc_dointvec,
2604 .procname = "gc_elasticity",
2605 .data = &ip_rt_gc_elasticity,
2606 .maxlen = sizeof(int),
2608 .proc_handler = proc_dointvec,
2611 .procname = "mtu_expires",
2612 .data = &ip_rt_mtu_expires,
2613 .maxlen = sizeof(int),
2615 .proc_handler = proc_dointvec_jiffies,
2618 .procname = "min_pmtu",
2619 .data = &ip_rt_min_pmtu,
2620 .maxlen = sizeof(int),
2622 .proc_handler = proc_dointvec,
2625 .procname = "min_adv_mss",
2626 .data = &ip_rt_min_advmss,
2627 .maxlen = sizeof(int),
2629 .proc_handler = proc_dointvec,
2634 static struct ctl_table ipv4_route_flush_table[] = {
2636 .procname = "flush",
2637 .maxlen = sizeof(int),
2639 .proc_handler = ipv4_sysctl_rtcache_flush,
2644 static __net_init int sysctl_route_net_init(struct net *net)
2646 struct ctl_table *tbl;
2648 tbl = ipv4_route_flush_table;
2649 if (!net_eq(net, &init_net)) {
2650 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2654 /* Don't export sysctls to unprivileged users */
2655 if (net->user_ns != &init_user_ns)
2656 tbl[0].procname = NULL;
2658 tbl[0].extra1 = net;
2660 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2661 if (!net->ipv4.route_hdr)
2666 if (tbl != ipv4_route_flush_table)
2672 static __net_exit void sysctl_route_net_exit(struct net *net)
2674 struct ctl_table *tbl;
2676 tbl = net->ipv4.route_hdr->ctl_table_arg;
2677 unregister_net_sysctl_table(net->ipv4.route_hdr);
2678 BUG_ON(tbl == ipv4_route_flush_table);
2682 static __net_initdata struct pernet_operations sysctl_route_ops = {
2683 .init = sysctl_route_net_init,
2684 .exit = sysctl_route_net_exit,
2688 static __net_init int rt_genid_init(struct net *net)
2690 atomic_set(&net->ipv4.rt_genid, 0);
2691 atomic_set(&net->fnhe_genid, 0);
2692 get_random_bytes(&net->ipv4.dev_addr_genid,
2693 sizeof(net->ipv4.dev_addr_genid));
2697 static __net_initdata struct pernet_operations rt_genid_ops = {
2698 .init = rt_genid_init,
2701 static int __net_init ipv4_inetpeer_init(struct net *net)
2703 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2707 inet_peer_base_init(bp);
2708 net->ipv4.peers = bp;
2712 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2714 struct inet_peer_base *bp = net->ipv4.peers;
2716 net->ipv4.peers = NULL;
2717 inetpeer_invalidate_tree(bp);
2721 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2722 .init = ipv4_inetpeer_init,
2723 .exit = ipv4_inetpeer_exit,
2726 #ifdef CONFIG_IP_ROUTE_CLASSID
2727 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2728 #endif /* CONFIG_IP_ROUTE_CLASSID */
2730 int __init ip_rt_init(void)
2735 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2737 panic("IP: failed to allocate ip_idents\n");
2739 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2741 for_each_possible_cpu(cpu) {
2742 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
2744 INIT_LIST_HEAD(&ul->head);
2745 spin_lock_init(&ul->lock);
2747 #ifdef CONFIG_IP_ROUTE_CLASSID
2748 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2750 panic("IP: failed to allocate ip_rt_acct\n");
2753 ipv4_dst_ops.kmem_cachep =
2754 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2755 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2757 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2759 if (dst_entries_init(&ipv4_dst_ops) < 0)
2760 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2762 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2763 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2765 ipv4_dst_ops.gc_thresh = ~0;
2766 ip_rt_max_size = INT_MAX;
2771 if (ip_rt_proc_init())
2772 pr_err("Unable to create route proc files\n");
2777 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2779 #ifdef CONFIG_SYSCTL
2780 register_pernet_subsys(&sysctl_route_ops);
2782 register_pernet_subsys(&rt_genid_ops);
2783 register_pernet_subsys(&ipv4_inetpeer_ops);
2787 #ifdef CONFIG_SYSCTL
2789 * We really need to sanitize the damn ipv4 init order, then all
2790 * this nonsense will go away.
2792 void __init ip_static_sysctl_init(void)
2794 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);