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 <linux/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/dst_metadata.h>
95 #include <net/net_namespace.h>
96 #include <net/protocol.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/lwtunnel.h>
107 #include <net/netevent.h>
108 #include <net/rtnetlink.h>
110 #include <linux/sysctl.h>
112 #include <net/secure_seq.h>
113 #include <net/ip_tunnels.h>
114 #include <net/l3mdev.h>
116 #include "fib_lookup.h"
118 #define RT_FL_TOS(oldflp4) \
119 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
121 #define RT_GC_TIMEOUT (300*HZ)
123 static int ip_rt_max_size;
124 static int ip_rt_redirect_number __read_mostly = 9;
125 static int ip_rt_redirect_load __read_mostly = HZ / 50;
126 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
127 static int ip_rt_error_cost __read_mostly = HZ;
128 static int ip_rt_error_burst __read_mostly = 5 * HZ;
129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
130 static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly = 256;
133 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
136 * Interface to generic destination cache.
139 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
140 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
141 static unsigned int ipv4_mtu(const struct dst_entry *dst);
142 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
143 static void ipv4_link_failure(struct sk_buff *skb);
144 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
145 struct sk_buff *skb, u32 mtu);
146 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
147 struct sk_buff *skb);
148 static void ipv4_dst_destroy(struct dst_entry *dst);
150 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
156 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
159 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr);
161 static struct dst_ops ipv4_dst_ops = {
163 .check = ipv4_dst_check,
164 .default_advmss = ipv4_default_advmss,
166 .cow_metrics = ipv4_cow_metrics,
167 .destroy = ipv4_dst_destroy,
168 .negative_advice = ipv4_negative_advice,
169 .link_failure = ipv4_link_failure,
170 .update_pmtu = ip_rt_update_pmtu,
171 .redirect = ip_do_redirect,
172 .local_out = __ip_local_out,
173 .neigh_lookup = ipv4_neigh_lookup,
174 .confirm_neigh = ipv4_confirm_neigh,
177 #define ECN_OR_COST(class) TC_PRIO_##class
179 const __u8 ip_tos2prio[16] = {
181 ECN_OR_COST(BESTEFFORT),
183 ECN_OR_COST(BESTEFFORT),
189 ECN_OR_COST(INTERACTIVE),
191 ECN_OR_COST(INTERACTIVE),
192 TC_PRIO_INTERACTIVE_BULK,
193 ECN_OR_COST(INTERACTIVE_BULK),
194 TC_PRIO_INTERACTIVE_BULK,
195 ECN_OR_COST(INTERACTIVE_BULK)
197 EXPORT_SYMBOL(ip_tos2prio);
199 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
200 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
202 #ifdef CONFIG_PROC_FS
203 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
207 return SEQ_START_TOKEN;
210 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
216 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
220 static int rt_cache_seq_show(struct seq_file *seq, void *v)
222 if (v == SEQ_START_TOKEN)
223 seq_printf(seq, "%-127s\n",
224 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
225 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
230 static const struct seq_operations rt_cache_seq_ops = {
231 .start = rt_cache_seq_start,
232 .next = rt_cache_seq_next,
233 .stop = rt_cache_seq_stop,
234 .show = rt_cache_seq_show,
237 static int rt_cache_seq_open(struct inode *inode, struct file *file)
239 return seq_open(file, &rt_cache_seq_ops);
242 static const struct file_operations rt_cache_seq_fops = {
243 .open = rt_cache_seq_open,
246 .release = seq_release,
250 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
255 return SEQ_START_TOKEN;
257 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
258 if (!cpu_possible(cpu))
261 return &per_cpu(rt_cache_stat, cpu);
266 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
270 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
271 if (!cpu_possible(cpu))
274 return &per_cpu(rt_cache_stat, cpu);
280 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
285 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
287 struct rt_cache_stat *st = v;
289 if (v == SEQ_START_TOKEN) {
290 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
294 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
295 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
296 dst_entries_get_slow(&ipv4_dst_ops),
309 0, /* st->gc_total */
310 0, /* st->gc_ignored */
311 0, /* st->gc_goal_miss */
312 0, /* st->gc_dst_overflow */
313 0, /* st->in_hlist_search */
314 0 /* st->out_hlist_search */
319 static const struct seq_operations rt_cpu_seq_ops = {
320 .start = rt_cpu_seq_start,
321 .next = rt_cpu_seq_next,
322 .stop = rt_cpu_seq_stop,
323 .show = rt_cpu_seq_show,
327 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
329 return seq_open(file, &rt_cpu_seq_ops);
332 static const struct file_operations rt_cpu_seq_fops = {
333 .open = rt_cpu_seq_open,
336 .release = seq_release,
339 #ifdef CONFIG_IP_ROUTE_CLASSID
340 static int rt_acct_proc_show(struct seq_file *m, void *v)
342 struct ip_rt_acct *dst, *src;
345 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
349 for_each_possible_cpu(i) {
350 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
351 for (j = 0; j < 256; j++) {
352 dst[j].o_bytes += src[j].o_bytes;
353 dst[j].o_packets += src[j].o_packets;
354 dst[j].i_bytes += src[j].i_bytes;
355 dst[j].i_packets += src[j].i_packets;
359 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
365 static int __net_init ip_rt_do_proc_init(struct net *net)
367 struct proc_dir_entry *pde;
369 pde = proc_create("rt_cache", 0444, net->proc_net,
374 pde = proc_create("rt_cache", 0444,
375 net->proc_net_stat, &rt_cpu_seq_fops);
379 #ifdef CONFIG_IP_ROUTE_CLASSID
380 pde = proc_create_single("rt_acct", 0, net->proc_net,
387 #ifdef CONFIG_IP_ROUTE_CLASSID
389 remove_proc_entry("rt_cache", net->proc_net_stat);
392 remove_proc_entry("rt_cache", net->proc_net);
397 static void __net_exit ip_rt_do_proc_exit(struct net *net)
399 remove_proc_entry("rt_cache", net->proc_net_stat);
400 remove_proc_entry("rt_cache", net->proc_net);
401 #ifdef CONFIG_IP_ROUTE_CLASSID
402 remove_proc_entry("rt_acct", net->proc_net);
406 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
407 .init = ip_rt_do_proc_init,
408 .exit = ip_rt_do_proc_exit,
411 static int __init ip_rt_proc_init(void)
413 return register_pernet_subsys(&ip_rt_proc_ops);
417 static inline int ip_rt_proc_init(void)
421 #endif /* CONFIG_PROC_FS */
423 static inline bool rt_is_expired(const struct rtable *rth)
425 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
428 void rt_cache_flush(struct net *net)
430 rt_genid_bump_ipv4(net);
433 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
437 struct net_device *dev = dst->dev;
438 const __be32 *pkey = daddr;
439 const struct rtable *rt;
442 rt = (const struct rtable *) dst;
444 pkey = (const __be32 *) &rt->rt_gateway;
446 pkey = &ip_hdr(skb)->daddr;
448 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
451 return neigh_create(&arp_tbl, pkey, dev);
454 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr)
456 struct net_device *dev = dst->dev;
457 const __be32 *pkey = daddr;
458 const struct rtable *rt;
460 rt = (const struct rtable *)dst;
462 pkey = (const __be32 *)&rt->rt_gateway;
465 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL)))
468 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey);
471 #define IP_IDENTS_SZ 2048u
473 static atomic_t *ip_idents __read_mostly;
474 static u32 *ip_tstamps __read_mostly;
476 /* In order to protect privacy, we add a perturbation to identifiers
477 * if one generator is seldom used. This makes hard for an attacker
478 * to infer how many packets were sent between two points in time.
480 u32 ip_idents_reserve(u32 hash, int segs)
482 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
483 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
484 u32 old = READ_ONCE(*p_tstamp);
485 u32 now = (u32)jiffies;
488 if (old != now && cmpxchg(p_tstamp, old, now) == old)
489 delta = prandom_u32_max(now - old);
491 /* Do not use atomic_add_return() as it makes UBSAN unhappy */
493 old = (u32)atomic_read(p_id);
494 new = old + delta + segs;
495 } while (atomic_cmpxchg(p_id, old, new) != old);
499 EXPORT_SYMBOL(ip_idents_reserve);
501 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
503 static u32 ip_idents_hashrnd __read_mostly;
506 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
508 hash = jhash_3words((__force u32)iph->daddr,
509 (__force u32)iph->saddr,
510 iph->protocol ^ net_hash_mix(net),
512 id = ip_idents_reserve(hash, segs);
515 EXPORT_SYMBOL(__ip_select_ident);
517 static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
518 const struct sock *sk,
519 const struct iphdr *iph,
521 u8 prot, u32 mark, int flow_flags)
524 const struct inet_sock *inet = inet_sk(sk);
526 oif = sk->sk_bound_dev_if;
528 tos = RT_CONN_FLAGS(sk);
529 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
531 flowi4_init_output(fl4, oif, mark, tos,
532 RT_SCOPE_UNIVERSE, prot,
534 iph->daddr, iph->saddr, 0, 0,
535 sock_net_uid(net, sk));
538 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
539 const struct sock *sk)
541 const struct net *net = dev_net(skb->dev);
542 const struct iphdr *iph = ip_hdr(skb);
543 int oif = skb->dev->ifindex;
544 u8 tos = RT_TOS(iph->tos);
545 u8 prot = iph->protocol;
546 u32 mark = skb->mark;
548 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0);
551 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
553 const struct inet_sock *inet = inet_sk(sk);
554 const struct ip_options_rcu *inet_opt;
555 __be32 daddr = inet->inet_daddr;
558 inet_opt = rcu_dereference(inet->inet_opt);
559 if (inet_opt && inet_opt->opt.srr)
560 daddr = inet_opt->opt.faddr;
561 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
562 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
563 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
564 inet_sk_flowi_flags(sk),
565 daddr, inet->inet_saddr, 0, 0, sk->sk_uid);
569 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
570 const struct sk_buff *skb)
573 build_skb_flow_key(fl4, skb, sk);
575 build_sk_flow_key(fl4, sk);
578 static DEFINE_SPINLOCK(fnhe_lock);
580 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
584 rt = rcu_dereference(fnhe->fnhe_rth_input);
586 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
587 dst_dev_put(&rt->dst);
588 dst_release(&rt->dst);
590 rt = rcu_dereference(fnhe->fnhe_rth_output);
592 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
593 dst_dev_put(&rt->dst);
594 dst_release(&rt->dst);
598 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
600 struct fib_nh_exception *fnhe, *oldest;
602 oldest = rcu_dereference(hash->chain);
603 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
604 fnhe = rcu_dereference(fnhe->fnhe_next)) {
605 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
608 fnhe_flush_routes(oldest);
612 static inline u32 fnhe_hashfun(__be32 daddr)
614 static u32 fnhe_hashrnd __read_mostly;
617 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
618 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
619 return hash_32(hval, FNHE_HASH_SHIFT);
622 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
624 rt->rt_pmtu = fnhe->fnhe_pmtu;
625 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked;
626 rt->dst.expires = fnhe->fnhe_expires;
629 rt->rt_flags |= RTCF_REDIRECTED;
630 rt->rt_gateway = fnhe->fnhe_gw;
631 rt->rt_uses_gateway = 1;
635 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
636 u32 pmtu, bool lock, unsigned long expires)
638 struct fnhe_hash_bucket *hash;
639 struct fib_nh_exception *fnhe;
645 genid = fnhe_genid(dev_net(nh->nh_dev));
646 hval = fnhe_hashfun(daddr);
648 spin_lock_bh(&fnhe_lock);
650 hash = rcu_dereference(nh->nh_exceptions);
652 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC);
655 rcu_assign_pointer(nh->nh_exceptions, hash);
661 for (fnhe = rcu_dereference(hash->chain); fnhe;
662 fnhe = rcu_dereference(fnhe->fnhe_next)) {
663 if (fnhe->fnhe_daddr == daddr)
669 if (fnhe->fnhe_genid != genid)
670 fnhe->fnhe_genid = genid;
674 fnhe->fnhe_pmtu = pmtu;
675 fnhe->fnhe_mtu_locked = lock;
677 fnhe->fnhe_expires = max(1UL, expires);
678 /* Update all cached dsts too */
679 rt = rcu_dereference(fnhe->fnhe_rth_input);
681 fill_route_from_fnhe(rt, fnhe);
682 rt = rcu_dereference(fnhe->fnhe_rth_output);
684 fill_route_from_fnhe(rt, fnhe);
686 if (depth > FNHE_RECLAIM_DEPTH)
687 fnhe = fnhe_oldest(hash);
689 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
693 fnhe->fnhe_next = hash->chain;
694 rcu_assign_pointer(hash->chain, fnhe);
696 fnhe->fnhe_genid = genid;
697 fnhe->fnhe_daddr = daddr;
699 fnhe->fnhe_pmtu = pmtu;
700 fnhe->fnhe_mtu_locked = lock;
701 fnhe->fnhe_expires = max(1UL, expires);
703 /* Exception created; mark the cached routes for the nexthop
704 * stale, so anyone caching it rechecks if this exception
707 rt = rcu_dereference(nh->nh_rth_input);
709 rt->dst.obsolete = DST_OBSOLETE_KILL;
711 for_each_possible_cpu(i) {
712 struct rtable __rcu **prt;
713 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
714 rt = rcu_dereference(*prt);
716 rt->dst.obsolete = DST_OBSOLETE_KILL;
720 fnhe->fnhe_stamp = jiffies;
723 spin_unlock_bh(&fnhe_lock);
726 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
729 __be32 new_gw = icmp_hdr(skb)->un.gateway;
730 __be32 old_gw = ip_hdr(skb)->saddr;
731 struct net_device *dev = skb->dev;
732 struct in_device *in_dev;
733 struct fib_result res;
737 switch (icmp_hdr(skb)->code & 7) {
739 case ICMP_REDIR_NETTOS:
740 case ICMP_REDIR_HOST:
741 case ICMP_REDIR_HOSTTOS:
748 if (rt->rt_gateway != old_gw)
751 in_dev = __in_dev_get_rcu(dev);
756 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
757 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
758 ipv4_is_zeronet(new_gw))
759 goto reject_redirect;
761 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
762 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
763 goto reject_redirect;
764 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
765 goto reject_redirect;
767 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
768 goto reject_redirect;
771 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw);
773 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev);
775 if (!(n->nud_state & NUD_VALID)) {
776 neigh_event_send(n, NULL);
778 if (fib_lookup(net, fl4, &res, 0) == 0) {
779 struct fib_nh *nh = &FIB_RES_NH(res);
781 update_or_create_fnhe(nh, fl4->daddr, new_gw,
783 jiffies + ip_rt_gc_timeout);
786 rt->dst.obsolete = DST_OBSOLETE_KILL;
787 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
794 #ifdef CONFIG_IP_ROUTE_VERBOSE
795 if (IN_DEV_LOG_MARTIANS(in_dev)) {
796 const struct iphdr *iph = (const struct iphdr *) skb->data;
797 __be32 daddr = iph->daddr;
798 __be32 saddr = iph->saddr;
800 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
801 " Advised path = %pI4 -> %pI4\n",
802 &old_gw, dev->name, &new_gw,
809 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
813 const struct iphdr *iph = (const struct iphdr *) skb->data;
814 struct net *net = dev_net(skb->dev);
815 int oif = skb->dev->ifindex;
816 u8 tos = RT_TOS(iph->tos);
817 u8 prot = iph->protocol;
818 u32 mark = skb->mark;
820 rt = (struct rtable *) dst;
822 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0);
823 __ip_do_redirect(rt, skb, &fl4, true);
826 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
828 struct rtable *rt = (struct rtable *)dst;
829 struct dst_entry *ret = dst;
832 if (dst->obsolete > 0) {
835 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
846 * 1. The first ip_rt_redirect_number redirects are sent
847 * with exponential backoff, then we stop sending them at all,
848 * assuming that the host ignores our redirects.
849 * 2. If we did not see packets requiring redirects
850 * during ip_rt_redirect_silence, we assume that the host
851 * forgot redirected route and start to send redirects again.
853 * This algorithm is much cheaper and more intelligent than dumb load limiting
856 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
857 * and "frag. need" (breaks PMTU discovery) in icmp.c.
860 void ip_rt_send_redirect(struct sk_buff *skb)
862 struct rtable *rt = skb_rtable(skb);
863 struct in_device *in_dev;
864 struct inet_peer *peer;
870 in_dev = __in_dev_get_rcu(rt->dst.dev);
871 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
875 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
876 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
879 net = dev_net(rt->dst.dev);
880 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
882 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
883 rt_nexthop(rt, ip_hdr(skb)->daddr));
887 /* No redirected packets during ip_rt_redirect_silence;
888 * reset the algorithm.
890 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) {
891 peer->rate_tokens = 0;
892 peer->n_redirects = 0;
895 /* Too many ignored redirects; do not send anything
896 * set dst.rate_last to the last seen redirected packet.
898 if (peer->n_redirects >= ip_rt_redirect_number) {
899 peer->rate_last = jiffies;
903 /* Check for load limit; set rate_last to the latest sent
906 if (peer->rate_tokens == 0 ||
909 (ip_rt_redirect_load << peer->rate_tokens)))) {
910 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
912 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
913 peer->rate_last = jiffies;
916 #ifdef CONFIG_IP_ROUTE_VERBOSE
918 peer->rate_tokens == ip_rt_redirect_number)
919 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
920 &ip_hdr(skb)->saddr, inet_iif(skb),
921 &ip_hdr(skb)->daddr, &gw);
928 static int ip_error(struct sk_buff *skb)
930 struct rtable *rt = skb_rtable(skb);
931 struct net_device *dev = skb->dev;
932 struct in_device *in_dev;
933 struct inet_peer *peer;
939 if (netif_is_l3_master(skb->dev)) {
940 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
945 in_dev = __in_dev_get_rcu(dev);
947 /* IP on this device is disabled. */
951 net = dev_net(rt->dst.dev);
952 if (!IN_DEV_FORWARD(in_dev)) {
953 switch (rt->dst.error) {
955 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS);
959 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
965 switch (rt->dst.error) {
970 code = ICMP_HOST_UNREACH;
973 code = ICMP_NET_UNREACH;
974 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
977 code = ICMP_PKT_FILTERED;
981 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
982 l3mdev_master_ifindex(skb->dev), 1);
987 peer->rate_tokens += now - peer->rate_last;
988 if (peer->rate_tokens > ip_rt_error_burst)
989 peer->rate_tokens = ip_rt_error_burst;
990 peer->rate_last = now;
991 if (peer->rate_tokens >= ip_rt_error_cost)
992 peer->rate_tokens -= ip_rt_error_cost;
998 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1000 out: kfree_skb(skb);
1004 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
1006 struct dst_entry *dst = &rt->dst;
1007 u32 old_mtu = ipv4_mtu(dst);
1008 struct fib_result res;
1011 if (ip_mtu_locked(dst))
1017 if (mtu < ip_rt_min_pmtu) {
1019 mtu = min(old_mtu, ip_rt_min_pmtu);
1022 if (rt->rt_pmtu == mtu && !lock &&
1023 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
1027 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
1028 struct fib_nh *nh = &FIB_RES_NH(res);
1030 update_or_create_fnhe(nh, fl4->daddr, 0, mtu, lock,
1031 jiffies + ip_rt_mtu_expires);
1036 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1037 struct sk_buff *skb, u32 mtu)
1039 struct rtable *rt = (struct rtable *) dst;
1042 ip_rt_build_flow_key(&fl4, sk, skb);
1043 __ip_rt_update_pmtu(rt, &fl4, mtu);
1046 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1047 int oif, u8 protocol)
1049 const struct iphdr *iph = (const struct iphdr *) skb->data;
1052 u32 mark = IP4_REPLY_MARK(net, skb->mark);
1054 __build_flow_key(net, &fl4, NULL, iph, oif,
1055 RT_TOS(iph->tos), protocol, mark, 0);
1056 rt = __ip_route_output_key(net, &fl4);
1058 __ip_rt_update_pmtu(rt, &fl4, mtu);
1062 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1064 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1066 const struct iphdr *iph = (const struct iphdr *) skb->data;
1070 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0);
1072 if (!fl4.flowi4_mark)
1073 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1075 rt = __ip_route_output_key(sock_net(sk), &fl4);
1077 __ip_rt_update_pmtu(rt, &fl4, mtu);
1082 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1084 const struct iphdr *iph = (const struct iphdr *) skb->data;
1087 struct dst_entry *odst = NULL;
1089 struct net *net = sock_net(sk);
1093 if (!ip_sk_accept_pmtu(sk))
1096 odst = sk_dst_get(sk);
1098 if (sock_owned_by_user(sk) || !odst) {
1099 __ipv4_sk_update_pmtu(skb, sk, mtu);
1103 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1105 rt = (struct rtable *)odst;
1106 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1107 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1114 __ip_rt_update_pmtu((struct rtable *) xfrm_dst_path(&rt->dst), &fl4, mtu);
1116 if (!dst_check(&rt->dst, 0)) {
1118 dst_release(&rt->dst);
1120 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1128 sk_dst_set(sk, &rt->dst);
1134 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1136 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1137 int oif, u8 protocol)
1139 const struct iphdr *iph = (const struct iphdr *) skb->data;
1143 __build_flow_key(net, &fl4, NULL, iph, oif,
1144 RT_TOS(iph->tos), protocol, 0, 0);
1145 rt = __ip_route_output_key(net, &fl4);
1147 __ip_do_redirect(rt, skb, &fl4, false);
1151 EXPORT_SYMBOL_GPL(ipv4_redirect);
1153 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1155 const struct iphdr *iph = (const struct iphdr *) skb->data;
1158 struct net *net = sock_net(sk);
1160 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1161 rt = __ip_route_output_key(net, &fl4);
1163 __ip_do_redirect(rt, skb, &fl4, false);
1167 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1169 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1171 struct rtable *rt = (struct rtable *) dst;
1173 /* All IPV4 dsts are created with ->obsolete set to the value
1174 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1175 * into this function always.
1177 * When a PMTU/redirect information update invalidates a route,
1178 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1179 * DST_OBSOLETE_DEAD by dst_free().
1181 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1186 static void ipv4_send_dest_unreach(struct sk_buff *skb)
1188 struct ip_options opt;
1191 /* Recompile ip options since IPCB may not be valid anymore.
1192 * Also check we have a reasonable ipv4 header.
1194 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) ||
1195 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5)
1198 memset(&opt, 0, sizeof(opt));
1199 if (ip_hdr(skb)->ihl > 5) {
1200 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4))
1202 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr);
1205 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL);
1211 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt);
1214 static void ipv4_link_failure(struct sk_buff *skb)
1218 ipv4_send_dest_unreach(skb);
1220 rt = skb_rtable(skb);
1222 dst_set_expires(&rt->dst, 0);
1225 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1227 pr_debug("%s: %pI4 -> %pI4, %s\n",
1228 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1229 skb->dev ? skb->dev->name : "?");
1236 We do not cache source address of outgoing interface,
1237 because it is used only by IP RR, TS and SRR options,
1238 so that it out of fast path.
1240 BTW remember: "addr" is allowed to be not aligned
1244 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1248 if (rt_is_output_route(rt))
1249 src = ip_hdr(skb)->saddr;
1251 struct fib_result res;
1252 struct iphdr *iph = ip_hdr(skb);
1253 struct flowi4 fl4 = {
1254 .daddr = iph->daddr,
1255 .saddr = iph->saddr,
1256 .flowi4_tos = RT_TOS(iph->tos),
1257 .flowi4_oif = rt->dst.dev->ifindex,
1258 .flowi4_iif = skb->dev->ifindex,
1259 .flowi4_mark = skb->mark,
1263 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1264 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1266 src = inet_select_addr(rt->dst.dev,
1267 rt_nexthop(rt, iph->daddr),
1271 memcpy(addr, &src, 4);
1274 #ifdef CONFIG_IP_ROUTE_CLASSID
1275 static void set_class_tag(struct rtable *rt, u32 tag)
1277 if (!(rt->dst.tclassid & 0xFFFF))
1278 rt->dst.tclassid |= tag & 0xFFFF;
1279 if (!(rt->dst.tclassid & 0xFFFF0000))
1280 rt->dst.tclassid |= tag & 0xFFFF0000;
1284 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1286 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
1287 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
1290 return min(advmss, IPV4_MAX_PMTU - header_size);
1293 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1295 const struct rtable *rt = (const struct rtable *) dst;
1296 unsigned int mtu = rt->rt_pmtu;
1298 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1299 mtu = dst_metric_raw(dst, RTAX_MTU);
1304 mtu = READ_ONCE(dst->dev->mtu);
1306 if (unlikely(ip_mtu_locked(dst))) {
1307 if (rt->rt_uses_gateway && mtu > 576)
1311 mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
1313 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
1316 static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr)
1318 struct fnhe_hash_bucket *hash;
1319 struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1320 u32 hval = fnhe_hashfun(daddr);
1322 spin_lock_bh(&fnhe_lock);
1324 hash = rcu_dereference_protected(nh->nh_exceptions,
1325 lockdep_is_held(&fnhe_lock));
1328 fnhe_p = &hash->chain;
1329 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1331 if (fnhe->fnhe_daddr == daddr) {
1332 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1333 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1334 /* set fnhe_daddr to 0 to ensure it won't bind with
1335 * new dsts in rt_bind_exception().
1337 fnhe->fnhe_daddr = 0;
1338 fnhe_flush_routes(fnhe);
1339 kfree_rcu(fnhe, rcu);
1342 fnhe_p = &fnhe->fnhe_next;
1343 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1344 lockdep_is_held(&fnhe_lock));
1347 spin_unlock_bh(&fnhe_lock);
1350 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1352 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1353 struct fib_nh_exception *fnhe;
1359 hval = fnhe_hashfun(daddr);
1361 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1362 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1363 if (fnhe->fnhe_daddr == daddr) {
1364 if (fnhe->fnhe_expires &&
1365 time_after(jiffies, fnhe->fnhe_expires)) {
1366 ip_del_fnhe(nh, daddr);
1376 * 1. mtu on route is locked - use it
1377 * 2. mtu from nexthop exception
1378 * 3. mtu from egress device
1381 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr)
1383 struct fib_info *fi = res->fi;
1384 struct fib_nh *nh = &fi->fib_nh[res->nh_sel];
1385 struct net_device *dev = nh->nh_dev;
1388 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu ||
1389 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU))
1393 struct fib_nh_exception *fnhe;
1395 fnhe = find_exception(nh, daddr);
1396 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires))
1397 mtu = fnhe->fnhe_pmtu;
1401 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU);
1403 return mtu - lwtunnel_headroom(nh->nh_lwtstate, mtu);
1406 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1407 __be32 daddr, const bool do_cache)
1411 spin_lock_bh(&fnhe_lock);
1413 if (daddr == fnhe->fnhe_daddr) {
1414 struct rtable __rcu **porig;
1415 struct rtable *orig;
1416 int genid = fnhe_genid(dev_net(rt->dst.dev));
1418 if (rt_is_input_route(rt))
1419 porig = &fnhe->fnhe_rth_input;
1421 porig = &fnhe->fnhe_rth_output;
1422 orig = rcu_dereference(*porig);
1424 if (fnhe->fnhe_genid != genid) {
1425 fnhe->fnhe_genid = genid;
1427 fnhe->fnhe_pmtu = 0;
1428 fnhe->fnhe_expires = 0;
1429 fnhe->fnhe_mtu_locked = false;
1430 fnhe_flush_routes(fnhe);
1433 fill_route_from_fnhe(rt, fnhe);
1434 if (!rt->rt_gateway)
1435 rt->rt_gateway = daddr;
1439 rcu_assign_pointer(*porig, rt);
1441 dst_dev_put(&orig->dst);
1442 dst_release(&orig->dst);
1447 fnhe->fnhe_stamp = jiffies;
1449 spin_unlock_bh(&fnhe_lock);
1454 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1456 struct rtable *orig, *prev, **p;
1459 if (rt_is_input_route(rt)) {
1460 p = (struct rtable **)&nh->nh_rth_input;
1462 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1466 /* hold dst before doing cmpxchg() to avoid race condition
1470 prev = cmpxchg(p, orig, rt);
1473 dst_dev_put(&orig->dst);
1474 dst_release(&orig->dst);
1477 dst_release(&rt->dst);
1484 struct uncached_list {
1486 struct list_head head;
1489 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1491 void rt_add_uncached_list(struct rtable *rt)
1493 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1495 rt->rt_uncached_list = ul;
1497 spin_lock_bh(&ul->lock);
1498 list_add_tail(&rt->rt_uncached, &ul->head);
1499 spin_unlock_bh(&ul->lock);
1502 void rt_del_uncached_list(struct rtable *rt)
1504 if (!list_empty(&rt->rt_uncached)) {
1505 struct uncached_list *ul = rt->rt_uncached_list;
1507 spin_lock_bh(&ul->lock);
1508 list_del(&rt->rt_uncached);
1509 spin_unlock_bh(&ul->lock);
1513 static void ipv4_dst_destroy(struct dst_entry *dst)
1515 struct rtable *rt = (struct rtable *)dst;
1517 ip_dst_metrics_put(dst);
1518 rt_del_uncached_list(rt);
1521 void rt_flush_dev(struct net_device *dev)
1523 struct net *net = dev_net(dev);
1527 for_each_possible_cpu(cpu) {
1528 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1530 spin_lock_bh(&ul->lock);
1531 list_for_each_entry(rt, &ul->head, rt_uncached) {
1532 if (rt->dst.dev != dev)
1534 rt->dst.dev = net->loopback_dev;
1535 dev_hold(rt->dst.dev);
1538 spin_unlock_bh(&ul->lock);
1542 static bool rt_cache_valid(const struct rtable *rt)
1545 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1549 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1550 const struct fib_result *res,
1551 struct fib_nh_exception *fnhe,
1552 struct fib_info *fi, u16 type, u32 itag,
1553 const bool do_cache)
1555 bool cached = false;
1558 struct fib_nh *nh = &FIB_RES_NH(*res);
1560 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1561 rt->rt_gateway = nh->nh_gw;
1562 rt->rt_uses_gateway = 1;
1564 ip_dst_init_metrics(&rt->dst, fi->fib_metrics);
1566 #ifdef CONFIG_IP_ROUTE_CLASSID
1567 rt->dst.tclassid = nh->nh_tclassid;
1569 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
1571 cached = rt_bind_exception(rt, fnhe, daddr, do_cache);
1573 cached = rt_cache_route(nh, rt);
1574 if (unlikely(!cached)) {
1575 /* Routes we intend to cache in nexthop exception or
1576 * FIB nexthop have the DST_NOCACHE bit clear.
1577 * However, if we are unsuccessful at storing this
1578 * route into the cache we really need to set it.
1580 if (!rt->rt_gateway)
1581 rt->rt_gateway = daddr;
1582 rt_add_uncached_list(rt);
1585 rt_add_uncached_list(rt);
1587 #ifdef CONFIG_IP_ROUTE_CLASSID
1588 #ifdef CONFIG_IP_MULTIPLE_TABLES
1589 set_class_tag(rt, res->tclassid);
1591 set_class_tag(rt, itag);
1595 struct rtable *rt_dst_alloc(struct net_device *dev,
1596 unsigned int flags, u16 type,
1597 bool nopolicy, bool noxfrm, bool will_cache)
1601 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1602 (will_cache ? 0 : DST_HOST) |
1603 (nopolicy ? DST_NOPOLICY : 0) |
1604 (noxfrm ? DST_NOXFRM : 0));
1607 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1608 rt->rt_flags = flags;
1610 rt->rt_is_input = 0;
1613 rt->rt_mtu_locked = 0;
1615 rt->rt_uses_gateway = 0;
1616 INIT_LIST_HEAD(&rt->rt_uncached);
1618 rt->dst.output = ip_output;
1619 if (flags & RTCF_LOCAL)
1620 rt->dst.input = ip_local_deliver;
1625 EXPORT_SYMBOL(rt_dst_alloc);
1627 /* called in rcu_read_lock() section */
1628 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1629 u8 tos, struct net_device *dev,
1630 struct in_device *in_dev, u32 *itag)
1634 /* Primary sanity checks. */
1638 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1639 skb->protocol != htons(ETH_P_IP))
1642 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1645 if (ipv4_is_zeronet(saddr)) {
1646 if (!ipv4_is_local_multicast(daddr) &&
1647 ip_hdr(skb)->protocol != IPPROTO_IGMP)
1650 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1658 /* called in rcu_read_lock() section */
1659 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1660 u8 tos, struct net_device *dev, int our)
1662 struct in_device *in_dev = __in_dev_get_rcu(dev);
1663 unsigned int flags = RTCF_MULTICAST;
1668 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag);
1673 flags |= RTCF_LOCAL;
1675 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1676 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1680 #ifdef CONFIG_IP_ROUTE_CLASSID
1681 rth->dst.tclassid = itag;
1683 rth->dst.output = ip_rt_bug;
1684 rth->rt_is_input= 1;
1686 #ifdef CONFIG_IP_MROUTE
1687 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1688 rth->dst.input = ip_mr_input;
1690 RT_CACHE_STAT_INC(in_slow_mc);
1692 skb_dst_set(skb, &rth->dst);
1697 static void ip_handle_martian_source(struct net_device *dev,
1698 struct in_device *in_dev,
1699 struct sk_buff *skb,
1703 RT_CACHE_STAT_INC(in_martian_src);
1704 #ifdef CONFIG_IP_ROUTE_VERBOSE
1705 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1707 * RFC1812 recommendation, if source is martian,
1708 * the only hint is MAC header.
1710 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1711 &daddr, &saddr, dev->name);
1712 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1713 print_hex_dump(KERN_WARNING, "ll header: ",
1714 DUMP_PREFIX_OFFSET, 16, 1,
1715 skb_mac_header(skb),
1716 dev->hard_header_len, false);
1722 /* called in rcu_read_lock() section */
1723 static int __mkroute_input(struct sk_buff *skb,
1724 const struct fib_result *res,
1725 struct in_device *in_dev,
1726 __be32 daddr, __be32 saddr, u32 tos)
1728 struct fib_nh_exception *fnhe;
1731 struct in_device *out_dev;
1735 /* get a working reference to the output device */
1736 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1738 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1742 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1743 in_dev->dev, in_dev, &itag);
1745 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1751 do_cache = res->fi && !itag;
1752 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1753 skb->protocol == htons(ETH_P_IP) &&
1754 (IN_DEV_SHARED_MEDIA(out_dev) ||
1755 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1756 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1758 if (skb->protocol != htons(ETH_P_IP)) {
1759 /* Not IP (i.e. ARP). Do not create route, if it is
1760 * invalid for proxy arp. DNAT routes are always valid.
1762 * Proxy arp feature have been extended to allow, ARP
1763 * replies back to the same interface, to support
1764 * Private VLAN switch technologies. See arp.c.
1766 if (out_dev == in_dev &&
1767 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1773 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1776 rth = rcu_dereference(fnhe->fnhe_rth_input);
1778 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1779 if (rt_cache_valid(rth)) {
1780 skb_dst_set_noref(skb, &rth->dst);
1785 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1786 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1787 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1793 rth->rt_is_input = 1;
1794 RT_CACHE_STAT_INC(in_slow_tot);
1796 rth->dst.input = ip_forward;
1798 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag,
1800 lwtunnel_set_redirect(&rth->dst);
1801 skb_dst_set(skb, &rth->dst);
1808 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1809 /* To make ICMP packets follow the right flow, the multipath hash is
1810 * calculated from the inner IP addresses.
1812 static void ip_multipath_l3_keys(const struct sk_buff *skb,
1813 struct flow_keys *hash_keys)
1815 const struct iphdr *outer_iph = ip_hdr(skb);
1816 const struct iphdr *key_iph = outer_iph;
1817 const struct iphdr *inner_iph;
1818 const struct icmphdr *icmph;
1819 struct iphdr _inner_iph;
1820 struct icmphdr _icmph;
1822 if (likely(outer_iph->protocol != IPPROTO_ICMP))
1825 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1828 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1833 if (icmph->type != ICMP_DEST_UNREACH &&
1834 icmph->type != ICMP_REDIRECT &&
1835 icmph->type != ICMP_TIME_EXCEEDED &&
1836 icmph->type != ICMP_PARAMETERPROB)
1839 inner_iph = skb_header_pointer(skb,
1840 outer_iph->ihl * 4 + sizeof(_icmph),
1841 sizeof(_inner_iph), &_inner_iph);
1845 key_iph = inner_iph;
1847 hash_keys->addrs.v4addrs.src = key_iph->saddr;
1848 hash_keys->addrs.v4addrs.dst = key_iph->daddr;
1851 /* if skb is set it will be used and fl4 can be NULL */
1852 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
1853 const struct sk_buff *skb, struct flow_keys *flkeys)
1855 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0;
1856 struct flow_keys hash_keys;
1859 switch (net->ipv4.sysctl_fib_multipath_hash_policy) {
1861 memset(&hash_keys, 0, sizeof(hash_keys));
1862 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1864 ip_multipath_l3_keys(skb, &hash_keys);
1866 hash_keys.addrs.v4addrs.src = fl4->saddr;
1867 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1871 /* skb is currently provided only when forwarding */
1873 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
1874 struct flow_keys keys;
1876 /* short-circuit if we already have L4 hash present */
1878 return skb_get_hash_raw(skb) >> 1;
1880 memset(&hash_keys, 0, sizeof(hash_keys));
1883 skb_flow_dissect_flow_keys(skb, &keys, flag);
1887 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1888 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
1889 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
1890 hash_keys.ports.src = flkeys->ports.src;
1891 hash_keys.ports.dst = flkeys->ports.dst;
1892 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
1894 memset(&hash_keys, 0, sizeof(hash_keys));
1895 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1896 hash_keys.addrs.v4addrs.src = fl4->saddr;
1897 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1898 hash_keys.ports.src = fl4->fl4_sport;
1899 hash_keys.ports.dst = fl4->fl4_dport;
1900 hash_keys.basic.ip_proto = fl4->flowi4_proto;
1904 mhash = flow_hash_from_keys(&hash_keys);
1907 mhash = jhash_2words(mhash, multipath_hash, 0);
1911 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
1913 static int ip_mkroute_input(struct sk_buff *skb,
1914 struct fib_result *res,
1915 struct in_device *in_dev,
1916 __be32 daddr, __be32 saddr, u32 tos,
1917 struct flow_keys *hkeys)
1919 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1920 if (res->fi && res->fi->fib_nhs > 1) {
1921 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys);
1923 fib_select_multipath(res, h);
1927 /* create a routing cache entry */
1928 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1932 * NOTE. We drop all the packets that has local source
1933 * addresses, because every properly looped back packet
1934 * must have correct destination already attached by output routine.
1936 * Such approach solves two big problems:
1937 * 1. Not simplex devices are handled properly.
1938 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1939 * called with rcu_read_lock()
1942 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1943 u8 tos, struct net_device *dev,
1944 struct fib_result *res)
1946 struct in_device *in_dev = __in_dev_get_rcu(dev);
1947 struct flow_keys *flkeys = NULL, _flkeys;
1948 struct net *net = dev_net(dev);
1949 struct ip_tunnel_info *tun_info;
1951 unsigned int flags = 0;
1957 /* IP on this device is disabled. */
1962 /* Check for the most weird martians, which can be not detected
1966 tun_info = skb_tunnel_info(skb);
1967 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
1968 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
1970 fl4.flowi4_tun_key.tun_id = 0;
1973 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1974 goto martian_source;
1978 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1981 /* Accept zero addresses only to limited broadcast;
1982 * I even do not know to fix it or not. Waiting for complains :-)
1984 if (ipv4_is_zeronet(saddr))
1985 goto martian_source;
1987 if (ipv4_is_zeronet(daddr))
1988 goto martian_destination;
1990 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1991 * and call it once if daddr or/and saddr are loopback addresses
1993 if (ipv4_is_loopback(daddr)) {
1994 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1995 goto martian_destination;
1996 } else if (ipv4_is_loopback(saddr)) {
1997 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1998 goto martian_source;
2002 * Now we are ready to route packet.
2005 fl4.flowi4_iif = dev->ifindex;
2006 fl4.flowi4_mark = skb->mark;
2007 fl4.flowi4_tos = tos;
2008 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2009 fl4.flowi4_flags = 0;
2012 fl4.flowi4_uid = sock_net_uid(net, NULL);
2014 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) {
2017 fl4.flowi4_proto = 0;
2022 err = fib_lookup(net, &fl4, res, 0);
2024 if (!IN_DEV_FORWARD(in_dev))
2025 err = -EHOSTUNREACH;
2029 if (res->type == RTN_BROADCAST) {
2030 if (IN_DEV_BFORWARD(in_dev))
2035 if (res->type == RTN_LOCAL) {
2036 err = fib_validate_source(skb, saddr, daddr, tos,
2037 0, dev, in_dev, &itag);
2039 goto martian_source;
2043 if (!IN_DEV_FORWARD(in_dev)) {
2044 err = -EHOSTUNREACH;
2047 if (res->type != RTN_UNICAST)
2048 goto martian_destination;
2051 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys);
2055 if (skb->protocol != htons(ETH_P_IP))
2058 if (!ipv4_is_zeronet(saddr)) {
2059 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
2062 goto martian_source;
2064 flags |= RTCF_BROADCAST;
2065 res->type = RTN_BROADCAST;
2066 RT_CACHE_STAT_INC(in_brd);
2072 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
2073 if (rt_cache_valid(rth)) {
2074 skb_dst_set_noref(skb, &rth->dst);
2082 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev,
2083 flags | RTCF_LOCAL, res->type,
2084 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
2088 rth->dst.output= ip_rt_bug;
2089 #ifdef CONFIG_IP_ROUTE_CLASSID
2090 rth->dst.tclassid = itag;
2092 rth->rt_is_input = 1;
2094 RT_CACHE_STAT_INC(in_slow_tot);
2095 if (res->type == RTN_UNREACHABLE) {
2096 rth->dst.input= ip_error;
2097 rth->dst.error= -err;
2098 rth->rt_flags &= ~RTCF_LOCAL;
2102 struct fib_nh *nh = &FIB_RES_NH(*res);
2104 rth->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
2105 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
2106 WARN_ON(rth->dst.input == lwtunnel_input);
2107 rth->dst.lwtstate->orig_input = rth->dst.input;
2108 rth->dst.input = lwtunnel_input;
2111 if (unlikely(!rt_cache_route(nh, rth)))
2112 rt_add_uncached_list(rth);
2114 skb_dst_set(skb, &rth->dst);
2119 RT_CACHE_STAT_INC(in_no_route);
2120 res->type = RTN_UNREACHABLE;
2126 * Do not cache martian addresses: they should be logged (RFC1812)
2128 martian_destination:
2129 RT_CACHE_STAT_INC(in_martian_dst);
2130 #ifdef CONFIG_IP_ROUTE_VERBOSE
2131 if (IN_DEV_LOG_MARTIANS(in_dev))
2132 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2133 &daddr, &saddr, dev->name);
2145 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2149 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2150 u8 tos, struct net_device *dev)
2152 struct fib_result res;
2155 tos &= IPTOS_RT_MASK;
2157 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res);
2162 EXPORT_SYMBOL(ip_route_input_noref);
2164 /* called with rcu_read_lock held */
2165 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2166 u8 tos, struct net_device *dev, struct fib_result *res)
2168 /* Multicast recognition logic is moved from route cache to here.
2169 The problem was that too many Ethernet cards have broken/missing
2170 hardware multicast filters :-( As result the host on multicasting
2171 network acquires a lot of useless route cache entries, sort of
2172 SDR messages from all the world. Now we try to get rid of them.
2173 Really, provided software IP multicast filter is organized
2174 reasonably (at least, hashed), it does not result in a slowdown
2175 comparing with route cache reject entries.
2176 Note, that multicast routers are not affected, because
2177 route cache entry is created eventually.
2179 if (ipv4_is_multicast(daddr)) {
2180 struct in_device *in_dev = __in_dev_get_rcu(dev);
2186 our = ip_check_mc_rcu(in_dev, daddr, saddr,
2187 ip_hdr(skb)->protocol);
2189 /* check l3 master if no match yet */
2190 if (!our && netif_is_l3_slave(dev)) {
2191 struct in_device *l3_in_dev;
2193 l3_in_dev = __in_dev_get_rcu(skb->dev);
2195 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr,
2196 ip_hdr(skb)->protocol);
2200 #ifdef CONFIG_IP_MROUTE
2202 (!ipv4_is_local_multicast(daddr) &&
2203 IN_DEV_MFORWARD(in_dev))
2206 err = ip_route_input_mc(skb, daddr, saddr,
2212 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
2215 /* called with rcu_read_lock() */
2216 static struct rtable *__mkroute_output(const struct fib_result *res,
2217 const struct flowi4 *fl4, int orig_oif,
2218 struct net_device *dev_out,
2221 struct fib_info *fi = res->fi;
2222 struct fib_nh_exception *fnhe;
2223 struct in_device *in_dev;
2224 u16 type = res->type;
2228 in_dev = __in_dev_get_rcu(dev_out);
2230 return ERR_PTR(-EINVAL);
2232 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2233 if (ipv4_is_loopback(fl4->saddr) &&
2234 !(dev_out->flags & IFF_LOOPBACK) &&
2235 !netif_is_l3_master(dev_out))
2236 return ERR_PTR(-EINVAL);
2238 if (ipv4_is_lbcast(fl4->daddr))
2239 type = RTN_BROADCAST;
2240 else if (ipv4_is_multicast(fl4->daddr))
2241 type = RTN_MULTICAST;
2242 else if (ipv4_is_zeronet(fl4->daddr))
2243 return ERR_PTR(-EINVAL);
2245 if (dev_out->flags & IFF_LOOPBACK)
2246 flags |= RTCF_LOCAL;
2249 if (type == RTN_BROADCAST) {
2250 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2252 } else if (type == RTN_MULTICAST) {
2253 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2254 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2256 flags &= ~RTCF_LOCAL;
2259 /* If multicast route do not exist use
2260 * default one, but do not gateway in this case.
2263 if (fi && res->prefixlen < 4)
2265 } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2266 (orig_oif != dev_out->ifindex)) {
2267 /* For local routes that require a particular output interface
2268 * we do not want to cache the result. Caching the result
2269 * causes incorrect behaviour when there are multiple source
2270 * addresses on the interface, the end result being that if the
2271 * intended recipient is waiting on that interface for the
2272 * packet he won't receive it because it will be delivered on
2273 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2274 * be set to the loopback interface as well.
2280 do_cache &= fi != NULL;
2282 struct rtable __rcu **prth;
2283 struct fib_nh *nh = &FIB_RES_NH(*res);
2285 fnhe = find_exception(nh, fl4->daddr);
2289 prth = &fnhe->fnhe_rth_output;
2291 if (unlikely(fl4->flowi4_flags &
2292 FLOWI_FLAG_KNOWN_NH &&
2294 nh->nh_scope == RT_SCOPE_LINK))) {
2298 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
2300 rth = rcu_dereference(*prth);
2301 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst))
2306 rth = rt_dst_alloc(dev_out, flags, type,
2307 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2308 IN_DEV_CONF_GET(in_dev, NOXFRM),
2311 return ERR_PTR(-ENOBUFS);
2313 rth->rt_iif = orig_oif;
2315 RT_CACHE_STAT_INC(out_slow_tot);
2317 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2318 if (flags & RTCF_LOCAL &&
2319 !(dev_out->flags & IFF_LOOPBACK)) {
2320 rth->dst.output = ip_mc_output;
2321 RT_CACHE_STAT_INC(out_slow_mc);
2323 #ifdef CONFIG_IP_MROUTE
2324 if (type == RTN_MULTICAST) {
2325 if (IN_DEV_MFORWARD(in_dev) &&
2326 !ipv4_is_local_multicast(fl4->daddr)) {
2327 rth->dst.input = ip_mr_input;
2328 rth->dst.output = ip_mc_output;
2334 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache);
2335 lwtunnel_set_redirect(&rth->dst);
2341 * Major route resolver routine.
2344 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2345 const struct sk_buff *skb)
2347 __u8 tos = RT_FL_TOS(fl4);
2348 struct fib_result res = {
2356 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2357 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2358 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2359 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2362 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);
2367 EXPORT_SYMBOL_GPL(ip_route_output_key_hash);
2369 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
2370 struct fib_result *res,
2371 const struct sk_buff *skb)
2373 struct net_device *dev_out = NULL;
2374 int orig_oif = fl4->flowi4_oif;
2375 unsigned int flags = 0;
2377 int err = -ENETUNREACH;
2380 rth = ERR_PTR(-EINVAL);
2381 if (ipv4_is_multicast(fl4->saddr) ||
2382 ipv4_is_lbcast(fl4->saddr) ||
2383 ipv4_is_zeronet(fl4->saddr))
2386 /* I removed check for oif == dev_out->oif here.
2387 It was wrong for two reasons:
2388 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2389 is assigned to multiple interfaces.
2390 2. Moreover, we are allowed to send packets with saddr
2391 of another iface. --ANK
2394 if (fl4->flowi4_oif == 0 &&
2395 (ipv4_is_multicast(fl4->daddr) ||
2396 ipv4_is_lbcast(fl4->daddr))) {
2397 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2398 dev_out = __ip_dev_find(net, fl4->saddr, false);
2402 /* Special hack: user can direct multicasts
2403 and limited broadcast via necessary interface
2404 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2405 This hack is not just for fun, it allows
2406 vic,vat and friends to work.
2407 They bind socket to loopback, set ttl to zero
2408 and expect that it will work.
2409 From the viewpoint of routing cache they are broken,
2410 because we are not allowed to build multicast path
2411 with loopback source addr (look, routing cache
2412 cannot know, that ttl is zero, so that packet
2413 will not leave this host and route is valid).
2414 Luckily, this hack is good workaround.
2417 fl4->flowi4_oif = dev_out->ifindex;
2421 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2422 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2423 if (!__ip_dev_find(net, fl4->saddr, false))
2429 if (fl4->flowi4_oif) {
2430 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2431 rth = ERR_PTR(-ENODEV);
2435 /* RACE: Check return value of inet_select_addr instead. */
2436 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2437 rth = ERR_PTR(-ENETUNREACH);
2440 if (ipv4_is_local_multicast(fl4->daddr) ||
2441 ipv4_is_lbcast(fl4->daddr) ||
2442 fl4->flowi4_proto == IPPROTO_IGMP) {
2444 fl4->saddr = inet_select_addr(dev_out, 0,
2449 if (ipv4_is_multicast(fl4->daddr))
2450 fl4->saddr = inet_select_addr(dev_out, 0,
2452 else if (!fl4->daddr)
2453 fl4->saddr = inet_select_addr(dev_out, 0,
2459 fl4->daddr = fl4->saddr;
2461 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2462 dev_out = net->loopback_dev;
2463 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2464 res->type = RTN_LOCAL;
2465 flags |= RTCF_LOCAL;
2469 err = fib_lookup(net, fl4, res, 0);
2473 if (fl4->flowi4_oif &&
2474 (ipv4_is_multicast(fl4->daddr) ||
2475 !netif_index_is_l3_master(net, fl4->flowi4_oif))) {
2476 /* Apparently, routing tables are wrong. Assume,
2477 that the destination is on link.
2480 Because we are allowed to send to iface
2481 even if it has NO routes and NO assigned
2482 addresses. When oif is specified, routing
2483 tables are looked up with only one purpose:
2484 to catch if destination is gatewayed, rather than
2485 direct. Moreover, if MSG_DONTROUTE is set,
2486 we send packet, ignoring both routing tables
2487 and ifaddr state. --ANK
2490 We could make it even if oif is unknown,
2491 likely IPv6, but we do not.
2494 if (fl4->saddr == 0)
2495 fl4->saddr = inet_select_addr(dev_out, 0,
2497 res->type = RTN_UNICAST;
2504 if (res->type == RTN_LOCAL) {
2506 if (res->fi->fib_prefsrc)
2507 fl4->saddr = res->fi->fib_prefsrc;
2509 fl4->saddr = fl4->daddr;
2512 /* L3 master device is the loopback for that domain */
2513 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
2516 /* make sure orig_oif points to fib result device even
2517 * though packet rx/tx happens over loopback or l3mdev
2519 orig_oif = FIB_RES_OIF(*res);
2521 fl4->flowi4_oif = dev_out->ifindex;
2522 flags |= RTCF_LOCAL;
2526 fib_select_path(net, res, fl4, skb);
2528 dev_out = FIB_RES_DEV(*res);
2529 fl4->flowi4_oif = dev_out->ifindex;
2533 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);
2539 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2544 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2546 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2548 return mtu ? : dst->dev->mtu;
2551 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2552 struct sk_buff *skb, u32 mtu)
2556 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2557 struct sk_buff *skb)
2561 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2567 static struct dst_ops ipv4_dst_blackhole_ops = {
2569 .check = ipv4_blackhole_dst_check,
2570 .mtu = ipv4_blackhole_mtu,
2571 .default_advmss = ipv4_default_advmss,
2572 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2573 .redirect = ipv4_rt_blackhole_redirect,
2574 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2575 .neigh_lookup = ipv4_neigh_lookup,
2578 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2580 struct rtable *ort = (struct rtable *) dst_orig;
2583 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0);
2585 struct dst_entry *new = &rt->dst;
2588 new->input = dst_discard;
2589 new->output = dst_discard_out;
2591 new->dev = net->loopback_dev;
2595 rt->rt_is_input = ort->rt_is_input;
2596 rt->rt_iif = ort->rt_iif;
2597 rt->rt_pmtu = ort->rt_pmtu;
2598 rt->rt_mtu_locked = ort->rt_mtu_locked;
2600 rt->rt_genid = rt_genid_ipv4(net);
2601 rt->rt_flags = ort->rt_flags;
2602 rt->rt_type = ort->rt_type;
2603 rt->rt_gateway = ort->rt_gateway;
2604 rt->rt_uses_gateway = ort->rt_uses_gateway;
2606 INIT_LIST_HEAD(&rt->rt_uncached);
2609 dst_release(dst_orig);
2611 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2614 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2615 const struct sock *sk)
2617 struct rtable *rt = __ip_route_output_key(net, flp4);
2622 if (flp4->flowi4_proto)
2623 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2624 flowi4_to_flowi(flp4),
2629 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2631 /* called with rcu_read_lock held */
2632 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2633 struct rtable *rt, u32 table_id, struct flowi4 *fl4,
2634 struct sk_buff *skb, u32 portid, u32 seq)
2637 struct nlmsghdr *nlh;
2638 unsigned long expires = 0;
2640 u32 metrics[RTAX_MAX];
2642 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), 0);
2646 r = nlmsg_data(nlh);
2647 r->rtm_family = AF_INET;
2648 r->rtm_dst_len = 32;
2650 r->rtm_tos = fl4->flowi4_tos;
2651 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT;
2652 if (nla_put_u32(skb, RTA_TABLE, table_id))
2653 goto nla_put_failure;
2654 r->rtm_type = rt->rt_type;
2655 r->rtm_scope = RT_SCOPE_UNIVERSE;
2656 r->rtm_protocol = RTPROT_UNSPEC;
2657 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2658 if (rt->rt_flags & RTCF_NOTIFY)
2659 r->rtm_flags |= RTM_F_NOTIFY;
2660 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2661 r->rtm_flags |= RTCF_DOREDIRECT;
2663 if (nla_put_in_addr(skb, RTA_DST, dst))
2664 goto nla_put_failure;
2666 r->rtm_src_len = 32;
2667 if (nla_put_in_addr(skb, RTA_SRC, src))
2668 goto nla_put_failure;
2671 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2672 goto nla_put_failure;
2673 #ifdef CONFIG_IP_ROUTE_CLASSID
2674 if (rt->dst.tclassid &&
2675 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2676 goto nla_put_failure;
2678 if (!rt_is_input_route(rt) &&
2679 fl4->saddr != src) {
2680 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2681 goto nla_put_failure;
2683 if (rt->rt_uses_gateway &&
2684 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2685 goto nla_put_failure;
2687 expires = rt->dst.expires;
2689 unsigned long now = jiffies;
2691 if (time_before(now, expires))
2697 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2698 if (rt->rt_pmtu && expires)
2699 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2700 if (rt->rt_mtu_locked && expires)
2701 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU);
2702 if (rtnetlink_put_metrics(skb, metrics) < 0)
2703 goto nla_put_failure;
2705 if (fl4->flowi4_mark &&
2706 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2707 goto nla_put_failure;
2709 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
2710 nla_put_u32(skb, RTA_UID,
2711 from_kuid_munged(current_user_ns(), fl4->flowi4_uid)))
2712 goto nla_put_failure;
2714 error = rt->dst.error;
2716 if (rt_is_input_route(rt)) {
2717 #ifdef CONFIG_IP_MROUTE
2718 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2719 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2720 int err = ipmr_get_route(net, skb,
2721 fl4->saddr, fl4->daddr,
2727 goto nla_put_failure;
2731 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif))
2732 goto nla_put_failure;
2735 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2736 goto nla_put_failure;
2738 nlmsg_end(skb, nlh);
2742 nlmsg_cancel(skb, nlh);
2746 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst,
2747 u8 ip_proto, __be16 sport,
2750 struct sk_buff *skb;
2753 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2757 /* Reserve room for dummy headers, this skb can pass
2758 * through good chunk of routing engine.
2760 skb_reset_mac_header(skb);
2761 skb_reset_network_header(skb);
2762 skb->protocol = htons(ETH_P_IP);
2763 iph = skb_put(skb, sizeof(struct iphdr));
2764 iph->protocol = ip_proto;
2770 skb_set_transport_header(skb, skb->len);
2772 switch (iph->protocol) {
2774 struct udphdr *udph;
2776 udph = skb_put_zero(skb, sizeof(struct udphdr));
2777 udph->source = sport;
2779 udph->len = sizeof(struct udphdr);
2784 struct tcphdr *tcph;
2786 tcph = skb_put_zero(skb, sizeof(struct tcphdr));
2787 tcph->source = sport;
2789 tcph->doff = sizeof(struct tcphdr) / 4;
2791 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr),
2795 case IPPROTO_ICMP: {
2796 struct icmphdr *icmph;
2798 icmph = skb_put_zero(skb, sizeof(struct icmphdr));
2799 icmph->type = ICMP_ECHO;
2807 static int inet_rtm_valid_getroute_req(struct sk_buff *skb,
2808 const struct nlmsghdr *nlh,
2810 struct netlink_ext_ack *extack)
2815 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2816 NL_SET_ERR_MSG(extack,
2817 "ipv4: Invalid header for route get request");
2821 if (!netlink_strict_get_check(skb))
2822 return nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX,
2823 rtm_ipv4_policy, extack);
2825 rtm = nlmsg_data(nlh);
2826 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
2827 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
2828 rtm->rtm_table || rtm->rtm_protocol ||
2829 rtm->rtm_scope || rtm->rtm_type) {
2830 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request");
2834 if (rtm->rtm_flags & ~(RTM_F_NOTIFY |
2835 RTM_F_LOOKUP_TABLE |
2837 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request");
2841 err = nlmsg_parse_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2842 rtm_ipv4_policy, extack);
2846 if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
2847 (tb[RTA_DST] && !rtm->rtm_dst_len)) {
2848 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
2852 for (i = 0; i <= RTA_MAX; i++) {
2868 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request");
2876 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2877 struct netlink_ext_ack *extack)
2879 struct net *net = sock_net(in_skb->sk);
2880 struct nlattr *tb[RTA_MAX+1];
2881 u32 table_id = RT_TABLE_MAIN;
2882 __be16 sport = 0, dport = 0;
2883 struct fib_result res = {};
2884 u8 ip_proto = IPPROTO_UDP;
2885 struct rtable *rt = NULL;
2886 struct sk_buff *skb;
2888 struct flowi4 fl4 = {};
2896 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
2900 rtm = nlmsg_data(nlh);
2901 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2902 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2903 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2904 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2906 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
2908 uid = (iif ? INVALID_UID : current_uid());
2910 if (tb[RTA_IP_PROTO]) {
2911 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
2912 &ip_proto, AF_INET, extack);
2918 sport = nla_get_be16(tb[RTA_SPORT]);
2921 dport = nla_get_be16(tb[RTA_DPORT]);
2923 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport);
2929 fl4.flowi4_tos = rtm->rtm_tos;
2930 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2931 fl4.flowi4_mark = mark;
2932 fl4.flowi4_uid = uid;
2934 fl4.fl4_sport = sport;
2936 fl4.fl4_dport = dport;
2937 fl4.flowi4_proto = ip_proto;
2942 struct net_device *dev;
2944 dev = dev_get_by_index_rcu(net, iif);
2950 fl4.flowi4_iif = iif; /* for rt_fill_info */
2953 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos,
2956 rt = skb_rtable(skb);
2957 if (err == 0 && rt->dst.error)
2958 err = -rt->dst.error;
2960 fl4.flowi4_iif = LOOPBACK_IFINDEX;
2961 skb->dev = net->loopback_dev;
2962 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb);
2967 skb_dst_set(skb, &rt->dst);
2973 if (rtm->rtm_flags & RTM_F_NOTIFY)
2974 rt->rt_flags |= RTCF_NOTIFY;
2976 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
2977 table_id = res.table ? res.table->tb_id : 0;
2979 /* reset skb for netlink reply msg */
2981 skb_reset_network_header(skb);
2982 skb_reset_transport_header(skb);
2983 skb_reset_mac_header(skb);
2985 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2987 err = fib_props[res.type].error;
2989 err = -EHOSTUNREACH;
2992 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
2993 nlh->nlmsg_seq, RTM_NEWROUTE, table_id,
2994 rt->rt_type, res.prefix, res.prefixlen,
2995 fl4.flowi4_tos, res.fi, 0);
2997 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb,
2998 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq);
3005 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3015 void ip_rt_multicast_event(struct in_device *in_dev)
3017 rt_cache_flush(dev_net(in_dev->dev));
3020 #ifdef CONFIG_SYSCTL
3021 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
3022 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
3023 static int ip_rt_gc_elasticity __read_mostly = 8;
3024 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU;
3026 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
3027 void __user *buffer,
3028 size_t *lenp, loff_t *ppos)
3030 struct net *net = (struct net *)__ctl->extra1;
3033 rt_cache_flush(net);
3034 fnhe_genid_bump(net);
3041 static struct ctl_table ipv4_route_table[] = {
3043 .procname = "gc_thresh",
3044 .data = &ipv4_dst_ops.gc_thresh,
3045 .maxlen = sizeof(int),
3047 .proc_handler = proc_dointvec,
3050 .procname = "max_size",
3051 .data = &ip_rt_max_size,
3052 .maxlen = sizeof(int),
3054 .proc_handler = proc_dointvec,
3057 /* Deprecated. Use gc_min_interval_ms */
3059 .procname = "gc_min_interval",
3060 .data = &ip_rt_gc_min_interval,
3061 .maxlen = sizeof(int),
3063 .proc_handler = proc_dointvec_jiffies,
3066 .procname = "gc_min_interval_ms",
3067 .data = &ip_rt_gc_min_interval,
3068 .maxlen = sizeof(int),
3070 .proc_handler = proc_dointvec_ms_jiffies,
3073 .procname = "gc_timeout",
3074 .data = &ip_rt_gc_timeout,
3075 .maxlen = sizeof(int),
3077 .proc_handler = proc_dointvec_jiffies,
3080 .procname = "gc_interval",
3081 .data = &ip_rt_gc_interval,
3082 .maxlen = sizeof(int),
3084 .proc_handler = proc_dointvec_jiffies,
3087 .procname = "redirect_load",
3088 .data = &ip_rt_redirect_load,
3089 .maxlen = sizeof(int),
3091 .proc_handler = proc_dointvec,
3094 .procname = "redirect_number",
3095 .data = &ip_rt_redirect_number,
3096 .maxlen = sizeof(int),
3098 .proc_handler = proc_dointvec,
3101 .procname = "redirect_silence",
3102 .data = &ip_rt_redirect_silence,
3103 .maxlen = sizeof(int),
3105 .proc_handler = proc_dointvec,
3108 .procname = "error_cost",
3109 .data = &ip_rt_error_cost,
3110 .maxlen = sizeof(int),
3112 .proc_handler = proc_dointvec,
3115 .procname = "error_burst",
3116 .data = &ip_rt_error_burst,
3117 .maxlen = sizeof(int),
3119 .proc_handler = proc_dointvec,
3122 .procname = "gc_elasticity",
3123 .data = &ip_rt_gc_elasticity,
3124 .maxlen = sizeof(int),
3126 .proc_handler = proc_dointvec,
3129 .procname = "mtu_expires",
3130 .data = &ip_rt_mtu_expires,
3131 .maxlen = sizeof(int),
3133 .proc_handler = proc_dointvec_jiffies,
3136 .procname = "min_pmtu",
3137 .data = &ip_rt_min_pmtu,
3138 .maxlen = sizeof(int),
3140 .proc_handler = proc_dointvec_minmax,
3141 .extra1 = &ip_min_valid_pmtu,
3144 .procname = "min_adv_mss",
3145 .data = &ip_rt_min_advmss,
3146 .maxlen = sizeof(int),
3148 .proc_handler = proc_dointvec,
3153 static struct ctl_table ipv4_route_flush_table[] = {
3155 .procname = "flush",
3156 .maxlen = sizeof(int),
3158 .proc_handler = ipv4_sysctl_rtcache_flush,
3163 static __net_init int sysctl_route_net_init(struct net *net)
3165 struct ctl_table *tbl;
3167 tbl = ipv4_route_flush_table;
3168 if (!net_eq(net, &init_net)) {
3169 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3173 /* Don't export sysctls to unprivileged users */
3174 if (net->user_ns != &init_user_ns)
3175 tbl[0].procname = NULL;
3177 tbl[0].extra1 = net;
3179 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
3180 if (!net->ipv4.route_hdr)
3185 if (tbl != ipv4_route_flush_table)
3191 static __net_exit void sysctl_route_net_exit(struct net *net)
3193 struct ctl_table *tbl;
3195 tbl = net->ipv4.route_hdr->ctl_table_arg;
3196 unregister_net_sysctl_table(net->ipv4.route_hdr);
3197 BUG_ON(tbl == ipv4_route_flush_table);
3201 static __net_initdata struct pernet_operations sysctl_route_ops = {
3202 .init = sysctl_route_net_init,
3203 .exit = sysctl_route_net_exit,
3207 static __net_init int rt_genid_init(struct net *net)
3209 atomic_set(&net->ipv4.rt_genid, 0);
3210 atomic_set(&net->fnhe_genid, 0);
3211 atomic_set(&net->ipv4.dev_addr_genid, get_random_int());
3215 static __net_initdata struct pernet_operations rt_genid_ops = {
3216 .init = rt_genid_init,
3219 static int __net_init ipv4_inetpeer_init(struct net *net)
3221 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3225 inet_peer_base_init(bp);
3226 net->ipv4.peers = bp;
3230 static void __net_exit ipv4_inetpeer_exit(struct net *net)
3232 struct inet_peer_base *bp = net->ipv4.peers;
3234 net->ipv4.peers = NULL;
3235 inetpeer_invalidate_tree(bp);
3239 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
3240 .init = ipv4_inetpeer_init,
3241 .exit = ipv4_inetpeer_exit,
3244 #ifdef CONFIG_IP_ROUTE_CLASSID
3245 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3246 #endif /* CONFIG_IP_ROUTE_CLASSID */
3248 int __init ip_rt_init(void)
3252 ip_idents = kmalloc_array(IP_IDENTS_SZ, sizeof(*ip_idents),
3255 panic("IP: failed to allocate ip_idents\n");
3257 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
3259 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
3261 panic("IP: failed to allocate ip_tstamps\n");
3263 for_each_possible_cpu(cpu) {
3264 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
3266 INIT_LIST_HEAD(&ul->head);
3267 spin_lock_init(&ul->lock);
3269 #ifdef CONFIG_IP_ROUTE_CLASSID
3270 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3272 panic("IP: failed to allocate ip_rt_acct\n");
3275 ipv4_dst_ops.kmem_cachep =
3276 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3277 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3279 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3281 if (dst_entries_init(&ipv4_dst_ops) < 0)
3282 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3284 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3285 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3287 ipv4_dst_ops.gc_thresh = ~0;
3288 ip_rt_max_size = INT_MAX;
3293 if (ip_rt_proc_init())
3294 pr_err("Unable to create route proc files\n");
3299 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL,
3300 RTNL_FLAG_DOIT_UNLOCKED);
3302 #ifdef CONFIG_SYSCTL
3303 register_pernet_subsys(&sysctl_route_ops);
3305 register_pernet_subsys(&rt_genid_ops);
3306 register_pernet_subsys(&ipv4_inetpeer_ops);
3310 #ifdef CONFIG_SYSCTL
3312 * We really need to sanitize the damn ipv4 init order, then all
3313 * this nonsense will go away.
3315 void __init ip_static_sysctl_init(void)
3317 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);