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 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,
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 (dst->dev->mtu < mtu)
968 if (rt->rt_pmtu && rt->rt_pmtu < mtu)
971 if (mtu < ip_rt_min_pmtu)
972 mtu = ip_rt_min_pmtu;
974 if (rt->rt_pmtu == mtu &&
975 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
979 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
980 struct fib_nh *nh = &FIB_RES_NH(res);
982 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
983 jiffies + ip_rt_mtu_expires);
988 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
989 struct sk_buff *skb, u32 mtu)
991 struct rtable *rt = (struct rtable *) dst;
994 ip_rt_build_flow_key(&fl4, sk, skb);
995 __ip_rt_update_pmtu(rt, &fl4, mtu);
998 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
999 int oif, u32 mark, u8 protocol, int flow_flags)
1001 const struct iphdr *iph = (const struct iphdr *) skb->data;
1006 mark = IP4_REPLY_MARK(net, skb->mark);
1008 __build_flow_key(&fl4, NULL, iph, oif,
1009 RT_TOS(iph->tos), protocol, mark, flow_flags);
1010 rt = __ip_route_output_key(net, &fl4);
1012 __ip_rt_update_pmtu(rt, &fl4, mtu);
1016 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1018 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1020 const struct iphdr *iph = (const struct iphdr *) skb->data;
1024 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1026 if (!fl4.flowi4_mark)
1027 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1029 rt = __ip_route_output_key(sock_net(sk), &fl4);
1031 __ip_rt_update_pmtu(rt, &fl4, mtu);
1036 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1038 const struct iphdr *iph = (const struct iphdr *) skb->data;
1041 struct dst_entry *odst = NULL;
1046 if (!ip_sk_accept_pmtu(sk))
1049 odst = sk_dst_get(sk);
1051 if (sock_owned_by_user(sk) || !odst) {
1052 __ipv4_sk_update_pmtu(skb, sk, mtu);
1056 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1058 rt = (struct rtable *)odst;
1059 if (odst->obsolete && odst->ops->check(odst, 0) == NULL) {
1060 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1067 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1069 if (!dst_check(&rt->dst, 0)) {
1071 dst_release(&rt->dst);
1073 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1081 sk_dst_set(sk, &rt->dst);
1087 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1089 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1090 int oif, u32 mark, u8 protocol, int flow_flags)
1092 const struct iphdr *iph = (const struct iphdr *) skb->data;
1096 __build_flow_key(&fl4, NULL, iph, oif,
1097 RT_TOS(iph->tos), protocol, mark, flow_flags);
1098 rt = __ip_route_output_key(net, &fl4);
1100 __ip_do_redirect(rt, skb, &fl4, false);
1104 EXPORT_SYMBOL_GPL(ipv4_redirect);
1106 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1108 const struct iphdr *iph = (const struct iphdr *) skb->data;
1112 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1113 rt = __ip_route_output_key(sock_net(sk), &fl4);
1115 __ip_do_redirect(rt, skb, &fl4, false);
1119 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1121 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1123 struct rtable *rt = (struct rtable *) dst;
1125 /* All IPV4 dsts are created with ->obsolete set to the value
1126 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1127 * into this function always.
1129 * When a PMTU/redirect information update invalidates a route,
1130 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1131 * DST_OBSOLETE_DEAD by dst_free().
1133 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1138 static void ipv4_link_failure(struct sk_buff *skb)
1142 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1144 rt = skb_rtable(skb);
1146 dst_set_expires(&rt->dst, 0);
1149 static int ip_rt_bug(struct sock *sk, struct sk_buff *skb)
1151 pr_debug("%s: %pI4 -> %pI4, %s\n",
1152 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1153 skb->dev ? skb->dev->name : "?");
1160 We do not cache source address of outgoing interface,
1161 because it is used only by IP RR, TS and SRR options,
1162 so that it out of fast path.
1164 BTW remember: "addr" is allowed to be not aligned
1168 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1172 if (rt_is_output_route(rt))
1173 src = ip_hdr(skb)->saddr;
1175 struct fib_result res;
1181 memset(&fl4, 0, sizeof(fl4));
1182 fl4.daddr = iph->daddr;
1183 fl4.saddr = iph->saddr;
1184 fl4.flowi4_tos = RT_TOS(iph->tos);
1185 fl4.flowi4_oif = rt->dst.dev->ifindex;
1186 fl4.flowi4_iif = skb->dev->ifindex;
1187 fl4.flowi4_mark = skb->mark;
1190 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1191 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1193 src = inet_select_addr(rt->dst.dev,
1194 rt_nexthop(rt, iph->daddr),
1198 memcpy(addr, &src, 4);
1201 #ifdef CONFIG_IP_ROUTE_CLASSID
1202 static void set_class_tag(struct rtable *rt, u32 tag)
1204 if (!(rt->dst.tclassid & 0xFFFF))
1205 rt->dst.tclassid |= tag & 0xFFFF;
1206 if (!(rt->dst.tclassid & 0xFFFF0000))
1207 rt->dst.tclassid |= tag & 0xFFFF0000;
1211 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1213 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1216 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1218 if (advmss > 65535 - 40)
1219 advmss = 65535 - 40;
1224 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1226 const struct rtable *rt = (const struct rtable *) dst;
1227 unsigned int mtu = rt->rt_pmtu;
1229 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1230 mtu = dst_metric_raw(dst, RTAX_MTU);
1235 mtu = dst->dev->mtu;
1237 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1238 if (rt->rt_uses_gateway && mtu > 576)
1242 return min_t(unsigned int, mtu, IP_MAX_MTU);
1245 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1247 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1248 struct fib_nh_exception *fnhe;
1254 hval = fnhe_hashfun(daddr);
1256 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1257 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1258 if (fnhe->fnhe_daddr == daddr)
1264 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1269 spin_lock_bh(&fnhe_lock);
1271 if (daddr == fnhe->fnhe_daddr) {
1272 struct rtable __rcu **porig;
1273 struct rtable *orig;
1274 int genid = fnhe_genid(dev_net(rt->dst.dev));
1276 if (rt_is_input_route(rt))
1277 porig = &fnhe->fnhe_rth_input;
1279 porig = &fnhe->fnhe_rth_output;
1280 orig = rcu_dereference(*porig);
1282 if (fnhe->fnhe_genid != genid) {
1283 fnhe->fnhe_genid = genid;
1285 fnhe->fnhe_pmtu = 0;
1286 fnhe->fnhe_expires = 0;
1287 fnhe_flush_routes(fnhe);
1290 fill_route_from_fnhe(rt, fnhe);
1291 if (!rt->rt_gateway)
1292 rt->rt_gateway = daddr;
1294 if (!(rt->dst.flags & DST_NOCACHE)) {
1295 rcu_assign_pointer(*porig, rt);
1301 fnhe->fnhe_stamp = jiffies;
1303 spin_unlock_bh(&fnhe_lock);
1308 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1310 struct rtable *orig, *prev, **p;
1313 if (rt_is_input_route(rt)) {
1314 p = (struct rtable **)&nh->nh_rth_input;
1316 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1320 prev = cmpxchg(p, orig, rt);
1330 struct uncached_list {
1332 struct list_head head;
1335 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1337 static void rt_add_uncached_list(struct rtable *rt)
1339 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1341 rt->rt_uncached_list = ul;
1343 spin_lock_bh(&ul->lock);
1344 list_add_tail(&rt->rt_uncached, &ul->head);
1345 spin_unlock_bh(&ul->lock);
1348 static void ipv4_dst_destroy(struct dst_entry *dst)
1350 struct rtable *rt = (struct rtable *) dst;
1352 if (!list_empty(&rt->rt_uncached)) {
1353 struct uncached_list *ul = rt->rt_uncached_list;
1355 spin_lock_bh(&ul->lock);
1356 list_del(&rt->rt_uncached);
1357 spin_unlock_bh(&ul->lock);
1361 void rt_flush_dev(struct net_device *dev)
1363 struct net *net = dev_net(dev);
1367 for_each_possible_cpu(cpu) {
1368 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1370 spin_lock_bh(&ul->lock);
1371 list_for_each_entry(rt, &ul->head, rt_uncached) {
1372 if (rt->dst.dev != dev)
1374 rt->dst.dev = net->loopback_dev;
1375 dev_hold(rt->dst.dev);
1378 spin_unlock_bh(&ul->lock);
1382 static bool rt_cache_valid(const struct rtable *rt)
1385 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1389 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1390 const struct fib_result *res,
1391 struct fib_nh_exception *fnhe,
1392 struct fib_info *fi, u16 type, u32 itag)
1394 bool cached = false;
1397 struct fib_nh *nh = &FIB_RES_NH(*res);
1399 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1400 rt->rt_gateway = nh->nh_gw;
1401 rt->rt_uses_gateway = 1;
1403 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1404 #ifdef CONFIG_IP_ROUTE_CLASSID
1405 rt->dst.tclassid = nh->nh_tclassid;
1408 cached = rt_bind_exception(rt, fnhe, daddr);
1409 else if (!(rt->dst.flags & DST_NOCACHE))
1410 cached = rt_cache_route(nh, rt);
1411 if (unlikely(!cached)) {
1412 /* Routes we intend to cache in nexthop exception or
1413 * FIB nexthop have the DST_NOCACHE bit clear.
1414 * However, if we are unsuccessful at storing this
1415 * route into the cache we really need to set it.
1417 rt->dst.flags |= DST_NOCACHE;
1418 if (!rt->rt_gateway)
1419 rt->rt_gateway = daddr;
1420 rt_add_uncached_list(rt);
1423 rt_add_uncached_list(rt);
1425 #ifdef CONFIG_IP_ROUTE_CLASSID
1426 #ifdef CONFIG_IP_MULTIPLE_TABLES
1427 set_class_tag(rt, res->tclassid);
1429 set_class_tag(rt, itag);
1433 static struct rtable *rt_dst_alloc(struct net_device *dev,
1434 bool nopolicy, bool noxfrm, bool will_cache)
1436 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1437 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1438 (nopolicy ? DST_NOPOLICY : 0) |
1439 (noxfrm ? DST_NOXFRM : 0));
1442 /* called in rcu_read_lock() section */
1443 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1444 u8 tos, struct net_device *dev, int our)
1447 struct in_device *in_dev = __in_dev_get_rcu(dev);
1451 /* Primary sanity checks. */
1456 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1457 skb->protocol != htons(ETH_P_IP))
1460 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1461 if (ipv4_is_loopback(saddr))
1464 if (ipv4_is_zeronet(saddr)) {
1465 if (!ipv4_is_local_multicast(daddr))
1468 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1473 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1474 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1478 #ifdef CONFIG_IP_ROUTE_CLASSID
1479 rth->dst.tclassid = itag;
1481 rth->dst.output = ip_rt_bug;
1483 rth->rt_genid = rt_genid_ipv4(dev_net(dev));
1484 rth->rt_flags = RTCF_MULTICAST;
1485 rth->rt_type = RTN_MULTICAST;
1486 rth->rt_is_input= 1;
1489 rth->rt_gateway = 0;
1490 rth->rt_uses_gateway = 0;
1491 INIT_LIST_HEAD(&rth->rt_uncached);
1493 rth->dst.input= ip_local_deliver;
1494 rth->rt_flags |= RTCF_LOCAL;
1497 #ifdef CONFIG_IP_MROUTE
1498 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1499 rth->dst.input = ip_mr_input;
1501 RT_CACHE_STAT_INC(in_slow_mc);
1503 skb_dst_set(skb, &rth->dst);
1515 static void ip_handle_martian_source(struct net_device *dev,
1516 struct in_device *in_dev,
1517 struct sk_buff *skb,
1521 RT_CACHE_STAT_INC(in_martian_src);
1522 #ifdef CONFIG_IP_ROUTE_VERBOSE
1523 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1525 * RFC1812 recommendation, if source is martian,
1526 * the only hint is MAC header.
1528 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1529 &daddr, &saddr, dev->name);
1530 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1531 print_hex_dump(KERN_WARNING, "ll header: ",
1532 DUMP_PREFIX_OFFSET, 16, 1,
1533 skb_mac_header(skb),
1534 dev->hard_header_len, true);
1540 /* called in rcu_read_lock() section */
1541 static int __mkroute_input(struct sk_buff *skb,
1542 const struct fib_result *res,
1543 struct in_device *in_dev,
1544 __be32 daddr, __be32 saddr, u32 tos)
1546 struct fib_nh_exception *fnhe;
1549 struct in_device *out_dev;
1550 unsigned int flags = 0;
1554 /* get a working reference to the output device */
1555 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1556 if (out_dev == NULL) {
1557 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1561 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1562 in_dev->dev, in_dev, &itag);
1564 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1570 do_cache = res->fi && !itag;
1571 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1572 skb->protocol == htons(ETH_P_IP) &&
1573 (IN_DEV_SHARED_MEDIA(out_dev) ||
1574 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1575 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1577 if (skb->protocol != htons(ETH_P_IP)) {
1578 /* Not IP (i.e. ARP). Do not create route, if it is
1579 * invalid for proxy arp. DNAT routes are always valid.
1581 * Proxy arp feature have been extended to allow, ARP
1582 * replies back to the same interface, to support
1583 * Private VLAN switch technologies. See arp.c.
1585 if (out_dev == in_dev &&
1586 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1592 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1595 rth = rcu_dereference(fnhe->fnhe_rth_input);
1597 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1599 if (rt_cache_valid(rth)) {
1600 skb_dst_set_noref(skb, &rth->dst);
1605 rth = rt_dst_alloc(out_dev->dev,
1606 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1607 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1613 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev));
1614 rth->rt_flags = flags;
1615 rth->rt_type = res->type;
1616 rth->rt_is_input = 1;
1619 rth->rt_gateway = 0;
1620 rth->rt_uses_gateway = 0;
1621 INIT_LIST_HEAD(&rth->rt_uncached);
1622 RT_CACHE_STAT_INC(in_slow_tot);
1624 rth->dst.input = ip_forward;
1625 rth->dst.output = ip_output;
1627 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1628 skb_dst_set(skb, &rth->dst);
1635 static int ip_mkroute_input(struct sk_buff *skb,
1636 struct fib_result *res,
1637 const struct flowi4 *fl4,
1638 struct in_device *in_dev,
1639 __be32 daddr, __be32 saddr, u32 tos)
1641 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1642 if (res->fi && res->fi->fib_nhs > 1)
1643 fib_select_multipath(res);
1646 /* create a routing cache entry */
1647 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1651 * NOTE. We drop all the packets that has local source
1652 * addresses, because every properly looped back packet
1653 * must have correct destination already attached by output routine.
1655 * Such approach solves two big problems:
1656 * 1. Not simplex devices are handled properly.
1657 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1658 * called with rcu_read_lock()
1661 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1662 u8 tos, struct net_device *dev)
1664 struct fib_result res;
1665 struct in_device *in_dev = __in_dev_get_rcu(dev);
1667 unsigned int flags = 0;
1671 struct net *net = dev_net(dev);
1674 /* IP on this device is disabled. */
1679 /* Check for the most weird martians, which can be not detected
1683 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1684 goto martian_source;
1687 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1690 /* Accept zero addresses only to limited broadcast;
1691 * I even do not know to fix it or not. Waiting for complains :-)
1693 if (ipv4_is_zeronet(saddr))
1694 goto martian_source;
1696 if (ipv4_is_zeronet(daddr))
1697 goto martian_destination;
1699 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1700 * and call it once if daddr or/and saddr are loopback addresses
1702 if (ipv4_is_loopback(daddr)) {
1703 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1704 goto martian_destination;
1705 } else if (ipv4_is_loopback(saddr)) {
1706 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1707 goto martian_source;
1711 * Now we are ready to route packet.
1714 fl4.flowi4_iif = dev->ifindex;
1715 fl4.flowi4_mark = skb->mark;
1716 fl4.flowi4_tos = tos;
1717 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1720 err = fib_lookup(net, &fl4, &res);
1722 if (!IN_DEV_FORWARD(in_dev))
1723 err = -EHOSTUNREACH;
1727 if (res.type == RTN_BROADCAST)
1730 if (res.type == RTN_LOCAL) {
1731 err = fib_validate_source(skb, saddr, daddr, tos,
1732 0, dev, in_dev, &itag);
1734 goto martian_source_keep_err;
1738 if (!IN_DEV_FORWARD(in_dev)) {
1739 err = -EHOSTUNREACH;
1742 if (res.type != RTN_UNICAST)
1743 goto martian_destination;
1745 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1749 if (skb->protocol != htons(ETH_P_IP))
1752 if (!ipv4_is_zeronet(saddr)) {
1753 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1756 goto martian_source_keep_err;
1758 flags |= RTCF_BROADCAST;
1759 res.type = RTN_BROADCAST;
1760 RT_CACHE_STAT_INC(in_brd);
1766 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1767 if (rt_cache_valid(rth)) {
1768 skb_dst_set_noref(skb, &rth->dst);
1776 rth = rt_dst_alloc(net->loopback_dev,
1777 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1781 rth->dst.input= ip_local_deliver;
1782 rth->dst.output= ip_rt_bug;
1783 #ifdef CONFIG_IP_ROUTE_CLASSID
1784 rth->dst.tclassid = itag;
1787 rth->rt_genid = rt_genid_ipv4(net);
1788 rth->rt_flags = flags|RTCF_LOCAL;
1789 rth->rt_type = res.type;
1790 rth->rt_is_input = 1;
1793 rth->rt_gateway = 0;
1794 rth->rt_uses_gateway = 0;
1795 INIT_LIST_HEAD(&rth->rt_uncached);
1796 RT_CACHE_STAT_INC(in_slow_tot);
1797 if (res.type == RTN_UNREACHABLE) {
1798 rth->dst.input= ip_error;
1799 rth->dst.error= -err;
1800 rth->rt_flags &= ~RTCF_LOCAL;
1803 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1804 rth->dst.flags |= DST_NOCACHE;
1805 rt_add_uncached_list(rth);
1808 skb_dst_set(skb, &rth->dst);
1813 RT_CACHE_STAT_INC(in_no_route);
1814 res.type = RTN_UNREACHABLE;
1819 * Do not cache martian addresses: they should be logged (RFC1812)
1821 martian_destination:
1822 RT_CACHE_STAT_INC(in_martian_dst);
1823 #ifdef CONFIG_IP_ROUTE_VERBOSE
1824 if (IN_DEV_LOG_MARTIANS(in_dev))
1825 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1826 &daddr, &saddr, dev->name);
1839 martian_source_keep_err:
1840 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1844 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1845 u8 tos, struct net_device *dev)
1851 /* Multicast recognition logic is moved from route cache to here.
1852 The problem was that too many Ethernet cards have broken/missing
1853 hardware multicast filters :-( As result the host on multicasting
1854 network acquires a lot of useless route cache entries, sort of
1855 SDR messages from all the world. Now we try to get rid of them.
1856 Really, provided software IP multicast filter is organized
1857 reasonably (at least, hashed), it does not result in a slowdown
1858 comparing with route cache reject entries.
1859 Note, that multicast routers are not affected, because
1860 route cache entry is created eventually.
1862 if (ipv4_is_multicast(daddr)) {
1863 struct in_device *in_dev = __in_dev_get_rcu(dev);
1866 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1867 ip_hdr(skb)->protocol);
1869 #ifdef CONFIG_IP_MROUTE
1871 (!ipv4_is_local_multicast(daddr) &&
1872 IN_DEV_MFORWARD(in_dev))
1875 int res = ip_route_input_mc(skb, daddr, saddr,
1884 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1888 EXPORT_SYMBOL(ip_route_input_noref);
1890 /* called with rcu_read_lock() */
1891 static struct rtable *__mkroute_output(const struct fib_result *res,
1892 const struct flowi4 *fl4, int orig_oif,
1893 struct net_device *dev_out,
1896 struct fib_info *fi = res->fi;
1897 struct fib_nh_exception *fnhe;
1898 struct in_device *in_dev;
1899 u16 type = res->type;
1903 in_dev = __in_dev_get_rcu(dev_out);
1905 return ERR_PTR(-EINVAL);
1907 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1908 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1909 return ERR_PTR(-EINVAL);
1911 if (ipv4_is_lbcast(fl4->daddr))
1912 type = RTN_BROADCAST;
1913 else if (ipv4_is_multicast(fl4->daddr))
1914 type = RTN_MULTICAST;
1915 else if (ipv4_is_zeronet(fl4->daddr))
1916 return ERR_PTR(-EINVAL);
1918 if (dev_out->flags & IFF_LOOPBACK)
1919 flags |= RTCF_LOCAL;
1922 if (type == RTN_BROADCAST) {
1923 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1925 } else if (type == RTN_MULTICAST) {
1926 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1927 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1929 flags &= ~RTCF_LOCAL;
1932 /* If multicast route do not exist use
1933 * default one, but do not gateway in this case.
1936 if (fi && res->prefixlen < 4)
1941 do_cache &= fi != NULL;
1943 struct rtable __rcu **prth;
1944 struct fib_nh *nh = &FIB_RES_NH(*res);
1946 fnhe = find_exception(nh, fl4->daddr);
1948 prth = &fnhe->fnhe_rth_output;
1950 if (unlikely(fl4->flowi4_flags &
1951 FLOWI_FLAG_KNOWN_NH &&
1953 nh->nh_scope == RT_SCOPE_LINK))) {
1957 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
1959 rth = rcu_dereference(*prth);
1960 if (rt_cache_valid(rth)) {
1961 dst_hold(&rth->dst);
1967 rth = rt_dst_alloc(dev_out,
1968 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1969 IN_DEV_CONF_GET(in_dev, NOXFRM),
1972 return ERR_PTR(-ENOBUFS);
1974 rth->dst.output = ip_output;
1976 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out));
1977 rth->rt_flags = flags;
1978 rth->rt_type = type;
1979 rth->rt_is_input = 0;
1980 rth->rt_iif = orig_oif ? : 0;
1982 rth->rt_gateway = 0;
1983 rth->rt_uses_gateway = 0;
1984 INIT_LIST_HEAD(&rth->rt_uncached);
1986 RT_CACHE_STAT_INC(out_slow_tot);
1988 if (flags & RTCF_LOCAL)
1989 rth->dst.input = ip_local_deliver;
1990 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1991 if (flags & RTCF_LOCAL &&
1992 !(dev_out->flags & IFF_LOOPBACK)) {
1993 rth->dst.output = ip_mc_output;
1994 RT_CACHE_STAT_INC(out_slow_mc);
1996 #ifdef CONFIG_IP_MROUTE
1997 if (type == RTN_MULTICAST) {
1998 if (IN_DEV_MFORWARD(in_dev) &&
1999 !ipv4_is_local_multicast(fl4->daddr)) {
2000 rth->dst.input = ip_mr_input;
2001 rth->dst.output = ip_mc_output;
2007 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
2013 * Major route resolver routine.
2016 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
2018 struct net_device *dev_out = NULL;
2019 __u8 tos = RT_FL_TOS(fl4);
2020 unsigned int flags = 0;
2021 struct fib_result res;
2029 orig_oif = fl4->flowi4_oif;
2031 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2032 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2033 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2034 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2038 rth = ERR_PTR(-EINVAL);
2039 if (ipv4_is_multicast(fl4->saddr) ||
2040 ipv4_is_lbcast(fl4->saddr) ||
2041 ipv4_is_zeronet(fl4->saddr))
2044 /* I removed check for oif == dev_out->oif here.
2045 It was wrong for two reasons:
2046 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2047 is assigned to multiple interfaces.
2048 2. Moreover, we are allowed to send packets with saddr
2049 of another iface. --ANK
2052 if (fl4->flowi4_oif == 0 &&
2053 (ipv4_is_multicast(fl4->daddr) ||
2054 ipv4_is_lbcast(fl4->daddr))) {
2055 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2056 dev_out = __ip_dev_find(net, fl4->saddr, false);
2057 if (dev_out == NULL)
2060 /* Special hack: user can direct multicasts
2061 and limited broadcast via necessary interface
2062 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2063 This hack is not just for fun, it allows
2064 vic,vat and friends to work.
2065 They bind socket to loopback, set ttl to zero
2066 and expect that it will work.
2067 From the viewpoint of routing cache they are broken,
2068 because we are not allowed to build multicast path
2069 with loopback source addr (look, routing cache
2070 cannot know, that ttl is zero, so that packet
2071 will not leave this host and route is valid).
2072 Luckily, this hack is good workaround.
2075 fl4->flowi4_oif = dev_out->ifindex;
2079 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2080 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2081 if (!__ip_dev_find(net, fl4->saddr, false))
2087 if (fl4->flowi4_oif) {
2088 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2089 rth = ERR_PTR(-ENODEV);
2090 if (dev_out == NULL)
2093 /* RACE: Check return value of inet_select_addr instead. */
2094 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2095 rth = ERR_PTR(-ENETUNREACH);
2098 if (ipv4_is_local_multicast(fl4->daddr) ||
2099 ipv4_is_lbcast(fl4->daddr)) {
2101 fl4->saddr = inet_select_addr(dev_out, 0,
2106 if (ipv4_is_multicast(fl4->daddr))
2107 fl4->saddr = inet_select_addr(dev_out, 0,
2109 else if (!fl4->daddr)
2110 fl4->saddr = inet_select_addr(dev_out, 0,
2116 fl4->daddr = fl4->saddr;
2118 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2119 dev_out = net->loopback_dev;
2120 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2121 res.type = RTN_LOCAL;
2122 flags |= RTCF_LOCAL;
2126 if (fib_lookup(net, fl4, &res)) {
2129 if (fl4->flowi4_oif) {
2130 /* Apparently, routing tables are wrong. Assume,
2131 that the destination is on link.
2134 Because we are allowed to send to iface
2135 even if it has NO routes and NO assigned
2136 addresses. When oif is specified, routing
2137 tables are looked up with only one purpose:
2138 to catch if destination is gatewayed, rather than
2139 direct. Moreover, if MSG_DONTROUTE is set,
2140 we send packet, ignoring both routing tables
2141 and ifaddr state. --ANK
2144 We could make it even if oif is unknown,
2145 likely IPv6, but we do not.
2148 if (fl4->saddr == 0)
2149 fl4->saddr = inet_select_addr(dev_out, 0,
2151 res.type = RTN_UNICAST;
2154 rth = ERR_PTR(-ENETUNREACH);
2158 if (res.type == RTN_LOCAL) {
2160 if (res.fi->fib_prefsrc)
2161 fl4->saddr = res.fi->fib_prefsrc;
2163 fl4->saddr = fl4->daddr;
2165 dev_out = net->loopback_dev;
2166 fl4->flowi4_oif = dev_out->ifindex;
2167 flags |= RTCF_LOCAL;
2171 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2172 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2173 fib_select_multipath(&res);
2176 if (!res.prefixlen &&
2177 res.table->tb_num_default > 1 &&
2178 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2179 fib_select_default(&res);
2182 fl4->saddr = FIB_RES_PREFSRC(net, res);
2184 dev_out = FIB_RES_DEV(res);
2185 fl4->flowi4_oif = dev_out->ifindex;
2189 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2195 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2197 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2202 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2204 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2206 return mtu ? : dst->dev->mtu;
2209 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2210 struct sk_buff *skb, u32 mtu)
2214 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2215 struct sk_buff *skb)
2219 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2225 static struct dst_ops ipv4_dst_blackhole_ops = {
2227 .check = ipv4_blackhole_dst_check,
2228 .mtu = ipv4_blackhole_mtu,
2229 .default_advmss = ipv4_default_advmss,
2230 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2231 .redirect = ipv4_rt_blackhole_redirect,
2232 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2233 .neigh_lookup = ipv4_neigh_lookup,
2236 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2238 struct rtable *ort = (struct rtable *) dst_orig;
2241 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2243 struct dst_entry *new = &rt->dst;
2246 new->input = dst_discard;
2247 new->output = dst_discard_sk;
2249 new->dev = ort->dst.dev;
2253 rt->rt_is_input = ort->rt_is_input;
2254 rt->rt_iif = ort->rt_iif;
2255 rt->rt_pmtu = ort->rt_pmtu;
2257 rt->rt_genid = rt_genid_ipv4(net);
2258 rt->rt_flags = ort->rt_flags;
2259 rt->rt_type = ort->rt_type;
2260 rt->rt_gateway = ort->rt_gateway;
2261 rt->rt_uses_gateway = ort->rt_uses_gateway;
2263 INIT_LIST_HEAD(&rt->rt_uncached);
2268 dst_release(dst_orig);
2270 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2273 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2276 struct rtable *rt = __ip_route_output_key(net, flp4);
2281 if (flp4->flowi4_proto)
2282 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2283 flowi4_to_flowi(flp4),
2288 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2290 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2291 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2292 u32 seq, int event, int nowait, unsigned int flags)
2294 struct rtable *rt = skb_rtable(skb);
2296 struct nlmsghdr *nlh;
2297 unsigned long expires = 0;
2299 u32 metrics[RTAX_MAX];
2301 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2305 r = nlmsg_data(nlh);
2306 r->rtm_family = AF_INET;
2307 r->rtm_dst_len = 32;
2309 r->rtm_tos = fl4->flowi4_tos;
2310 r->rtm_table = RT_TABLE_MAIN;
2311 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2312 goto nla_put_failure;
2313 r->rtm_type = rt->rt_type;
2314 r->rtm_scope = RT_SCOPE_UNIVERSE;
2315 r->rtm_protocol = RTPROT_UNSPEC;
2316 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2317 if (rt->rt_flags & RTCF_NOTIFY)
2318 r->rtm_flags |= RTM_F_NOTIFY;
2319 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2320 r->rtm_flags |= RTCF_DOREDIRECT;
2322 if (nla_put_be32(skb, RTA_DST, dst))
2323 goto nla_put_failure;
2325 r->rtm_src_len = 32;
2326 if (nla_put_be32(skb, RTA_SRC, src))
2327 goto nla_put_failure;
2330 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2331 goto nla_put_failure;
2332 #ifdef CONFIG_IP_ROUTE_CLASSID
2333 if (rt->dst.tclassid &&
2334 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2335 goto nla_put_failure;
2337 if (!rt_is_input_route(rt) &&
2338 fl4->saddr != src) {
2339 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2340 goto nla_put_failure;
2342 if (rt->rt_uses_gateway &&
2343 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2344 goto nla_put_failure;
2346 expires = rt->dst.expires;
2348 unsigned long now = jiffies;
2350 if (time_before(now, expires))
2356 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2357 if (rt->rt_pmtu && expires)
2358 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2359 if (rtnetlink_put_metrics(skb, metrics) < 0)
2360 goto nla_put_failure;
2362 if (fl4->flowi4_mark &&
2363 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2364 goto nla_put_failure;
2366 error = rt->dst.error;
2368 if (rt_is_input_route(rt)) {
2369 #ifdef CONFIG_IP_MROUTE
2370 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2371 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2372 int err = ipmr_get_route(net, skb,
2373 fl4->saddr, fl4->daddr,
2379 goto nla_put_failure;
2381 if (err == -EMSGSIZE)
2382 goto nla_put_failure;
2388 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2389 goto nla_put_failure;
2392 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2393 goto nla_put_failure;
2395 nlmsg_end(skb, nlh);
2399 nlmsg_cancel(skb, nlh);
2403 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2405 struct net *net = sock_net(in_skb->sk);
2407 struct nlattr *tb[RTA_MAX+1];
2408 struct rtable *rt = NULL;
2415 struct sk_buff *skb;
2417 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2421 rtm = nlmsg_data(nlh);
2423 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2429 /* Reserve room for dummy headers, this skb can pass
2430 through good chunk of routing engine.
2432 skb_reset_mac_header(skb);
2433 skb_reset_network_header(skb);
2435 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2436 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2437 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2439 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2440 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2441 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2442 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2444 memset(&fl4, 0, sizeof(fl4));
2447 fl4.flowi4_tos = rtm->rtm_tos;
2448 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2449 fl4.flowi4_mark = mark;
2452 struct net_device *dev;
2454 dev = __dev_get_by_index(net, iif);
2460 skb->protocol = htons(ETH_P_IP);
2464 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2467 rt = skb_rtable(skb);
2468 if (err == 0 && rt->dst.error)
2469 err = -rt->dst.error;
2471 rt = ip_route_output_key(net, &fl4);
2481 skb_dst_set(skb, &rt->dst);
2482 if (rtm->rtm_flags & RTM_F_NOTIFY)
2483 rt->rt_flags |= RTCF_NOTIFY;
2485 err = rt_fill_info(net, dst, src, &fl4, skb,
2486 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2487 RTM_NEWROUTE, 0, 0);
2491 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2500 void ip_rt_multicast_event(struct in_device *in_dev)
2502 rt_cache_flush(dev_net(in_dev->dev));
2505 #ifdef CONFIG_SYSCTL
2506 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2507 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2508 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2509 static int ip_rt_gc_elasticity __read_mostly = 8;
2511 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2512 void __user *buffer,
2513 size_t *lenp, loff_t *ppos)
2515 struct net *net = (struct net *)__ctl->extra1;
2518 rt_cache_flush(net);
2519 fnhe_genid_bump(net);
2526 static struct ctl_table ipv4_route_table[] = {
2528 .procname = "gc_thresh",
2529 .data = &ipv4_dst_ops.gc_thresh,
2530 .maxlen = sizeof(int),
2532 .proc_handler = proc_dointvec,
2535 .procname = "max_size",
2536 .data = &ip_rt_max_size,
2537 .maxlen = sizeof(int),
2539 .proc_handler = proc_dointvec,
2542 /* Deprecated. Use gc_min_interval_ms */
2544 .procname = "gc_min_interval",
2545 .data = &ip_rt_gc_min_interval,
2546 .maxlen = sizeof(int),
2548 .proc_handler = proc_dointvec_jiffies,
2551 .procname = "gc_min_interval_ms",
2552 .data = &ip_rt_gc_min_interval,
2553 .maxlen = sizeof(int),
2555 .proc_handler = proc_dointvec_ms_jiffies,
2558 .procname = "gc_timeout",
2559 .data = &ip_rt_gc_timeout,
2560 .maxlen = sizeof(int),
2562 .proc_handler = proc_dointvec_jiffies,
2565 .procname = "gc_interval",
2566 .data = &ip_rt_gc_interval,
2567 .maxlen = sizeof(int),
2569 .proc_handler = proc_dointvec_jiffies,
2572 .procname = "redirect_load",
2573 .data = &ip_rt_redirect_load,
2574 .maxlen = sizeof(int),
2576 .proc_handler = proc_dointvec,
2579 .procname = "redirect_number",
2580 .data = &ip_rt_redirect_number,
2581 .maxlen = sizeof(int),
2583 .proc_handler = proc_dointvec,
2586 .procname = "redirect_silence",
2587 .data = &ip_rt_redirect_silence,
2588 .maxlen = sizeof(int),
2590 .proc_handler = proc_dointvec,
2593 .procname = "error_cost",
2594 .data = &ip_rt_error_cost,
2595 .maxlen = sizeof(int),
2597 .proc_handler = proc_dointvec,
2600 .procname = "error_burst",
2601 .data = &ip_rt_error_burst,
2602 .maxlen = sizeof(int),
2604 .proc_handler = proc_dointvec,
2607 .procname = "gc_elasticity",
2608 .data = &ip_rt_gc_elasticity,
2609 .maxlen = sizeof(int),
2611 .proc_handler = proc_dointvec,
2614 .procname = "mtu_expires",
2615 .data = &ip_rt_mtu_expires,
2616 .maxlen = sizeof(int),
2618 .proc_handler = proc_dointvec_jiffies,
2621 .procname = "min_pmtu",
2622 .data = &ip_rt_min_pmtu,
2623 .maxlen = sizeof(int),
2625 .proc_handler = proc_dointvec,
2628 .procname = "min_adv_mss",
2629 .data = &ip_rt_min_advmss,
2630 .maxlen = sizeof(int),
2632 .proc_handler = proc_dointvec,
2637 static struct ctl_table ipv4_route_flush_table[] = {
2639 .procname = "flush",
2640 .maxlen = sizeof(int),
2642 .proc_handler = ipv4_sysctl_rtcache_flush,
2647 static __net_init int sysctl_route_net_init(struct net *net)
2649 struct ctl_table *tbl;
2651 tbl = ipv4_route_flush_table;
2652 if (!net_eq(net, &init_net)) {
2653 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2657 /* Don't export sysctls to unprivileged users */
2658 if (net->user_ns != &init_user_ns)
2659 tbl[0].procname = NULL;
2661 tbl[0].extra1 = net;
2663 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2664 if (net->ipv4.route_hdr == NULL)
2669 if (tbl != ipv4_route_flush_table)
2675 static __net_exit void sysctl_route_net_exit(struct net *net)
2677 struct ctl_table *tbl;
2679 tbl = net->ipv4.route_hdr->ctl_table_arg;
2680 unregister_net_sysctl_table(net->ipv4.route_hdr);
2681 BUG_ON(tbl == ipv4_route_flush_table);
2685 static __net_initdata struct pernet_operations sysctl_route_ops = {
2686 .init = sysctl_route_net_init,
2687 .exit = sysctl_route_net_exit,
2691 static __net_init int rt_genid_init(struct net *net)
2693 atomic_set(&net->ipv4.rt_genid, 0);
2694 atomic_set(&net->fnhe_genid, 0);
2695 get_random_bytes(&net->ipv4.dev_addr_genid,
2696 sizeof(net->ipv4.dev_addr_genid));
2700 static __net_initdata struct pernet_operations rt_genid_ops = {
2701 .init = rt_genid_init,
2704 static int __net_init ipv4_inetpeer_init(struct net *net)
2706 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2710 inet_peer_base_init(bp);
2711 net->ipv4.peers = bp;
2715 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2717 struct inet_peer_base *bp = net->ipv4.peers;
2719 net->ipv4.peers = NULL;
2720 inetpeer_invalidate_tree(bp);
2724 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2725 .init = ipv4_inetpeer_init,
2726 .exit = ipv4_inetpeer_exit,
2729 #ifdef CONFIG_IP_ROUTE_CLASSID
2730 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2731 #endif /* CONFIG_IP_ROUTE_CLASSID */
2733 int __init ip_rt_init(void)
2738 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2740 panic("IP: failed to allocate ip_idents\n");
2742 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2744 for_each_possible_cpu(cpu) {
2745 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
2747 INIT_LIST_HEAD(&ul->head);
2748 spin_lock_init(&ul->lock);
2750 #ifdef CONFIG_IP_ROUTE_CLASSID
2751 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2753 panic("IP: failed to allocate ip_rt_acct\n");
2756 ipv4_dst_ops.kmem_cachep =
2757 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2758 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2760 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2762 if (dst_entries_init(&ipv4_dst_ops) < 0)
2763 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2765 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2766 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2768 ipv4_dst_ops.gc_thresh = ~0;
2769 ip_rt_max_size = INT_MAX;
2774 if (ip_rt_proc_init())
2775 pr_err("Unable to create route proc files\n");
2780 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2782 #ifdef CONFIG_SYSCTL
2783 register_pernet_subsys(&sysctl_route_ops);
2785 register_pernet_subsys(&rt_genid_ops);
2786 register_pernet_subsys(&ipv4_inetpeer_ops);
2790 #ifdef CONFIG_SYSCTL
2792 * We really need to sanitize the damn ipv4 init order, then all
2793 * this nonsense will go away.
2795 void __init ip_static_sysctl_init(void)
2797 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);