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/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>
111 #include <linux/kmemleak.h>
113 #include <net/secure_seq.h>
114 #include <net/ip_tunnels.h>
115 #include <net/l3mdev.h>
117 #define RT_FL_TOS(oldflp4) \
118 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
120 #define RT_GC_TIMEOUT (300*HZ)
122 static int ip_rt_max_size;
123 static int ip_rt_redirect_number __read_mostly = 9;
124 static int ip_rt_redirect_load __read_mostly = HZ / 50;
125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly = HZ;
127 static int ip_rt_error_burst __read_mostly = 5 * HZ;
128 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
129 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
130 static int ip_rt_min_advmss __read_mostly = 256;
133 * Interface to generic destination cache.
136 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
137 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
138 static unsigned int ipv4_mtu(const struct dst_entry *dst);
139 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
140 static void ipv4_link_failure(struct sk_buff *skb);
141 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
142 struct sk_buff *skb, u32 mtu);
143 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
144 struct sk_buff *skb);
145 static void ipv4_dst_destroy(struct dst_entry *dst);
147 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
153 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
157 static struct dst_ops ipv4_dst_ops = {
159 .check = ipv4_dst_check,
160 .default_advmss = ipv4_default_advmss,
162 .cow_metrics = ipv4_cow_metrics,
163 .destroy = ipv4_dst_destroy,
164 .negative_advice = ipv4_negative_advice,
165 .link_failure = ipv4_link_failure,
166 .update_pmtu = ip_rt_update_pmtu,
167 .redirect = ip_do_redirect,
168 .local_out = __ip_local_out,
169 .neigh_lookup = ipv4_neigh_lookup,
172 #define ECN_OR_COST(class) TC_PRIO_##class
174 const __u8 ip_tos2prio[16] = {
176 ECN_OR_COST(BESTEFFORT),
178 ECN_OR_COST(BESTEFFORT),
184 ECN_OR_COST(INTERACTIVE),
186 ECN_OR_COST(INTERACTIVE),
187 TC_PRIO_INTERACTIVE_BULK,
188 ECN_OR_COST(INTERACTIVE_BULK),
189 TC_PRIO_INTERACTIVE_BULK,
190 ECN_OR_COST(INTERACTIVE_BULK)
192 EXPORT_SYMBOL(ip_tos2prio);
194 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
195 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
197 #ifdef CONFIG_PROC_FS
198 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
202 return SEQ_START_TOKEN;
205 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
211 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
215 static int rt_cache_seq_show(struct seq_file *seq, void *v)
217 if (v == SEQ_START_TOKEN)
218 seq_printf(seq, "%-127s\n",
219 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
220 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
225 static const struct seq_operations rt_cache_seq_ops = {
226 .start = rt_cache_seq_start,
227 .next = rt_cache_seq_next,
228 .stop = rt_cache_seq_stop,
229 .show = rt_cache_seq_show,
232 static int rt_cache_seq_open(struct inode *inode, struct file *file)
234 return seq_open(file, &rt_cache_seq_ops);
237 static const struct file_operations rt_cache_seq_fops = {
238 .owner = THIS_MODULE,
239 .open = rt_cache_seq_open,
242 .release = seq_release,
246 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
251 return SEQ_START_TOKEN;
253 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
254 if (!cpu_possible(cpu))
257 return &per_cpu(rt_cache_stat, cpu);
262 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
266 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
267 if (!cpu_possible(cpu))
270 return &per_cpu(rt_cache_stat, cpu);
276 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
281 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
283 struct rt_cache_stat *st = v;
285 if (v == SEQ_START_TOKEN) {
286 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");
290 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
291 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
292 dst_entries_get_slow(&ipv4_dst_ops),
305 0, /* st->gc_total */
306 0, /* st->gc_ignored */
307 0, /* st->gc_goal_miss */
308 0, /* st->gc_dst_overflow */
309 0, /* st->in_hlist_search */
310 0 /* st->out_hlist_search */
315 static const struct seq_operations rt_cpu_seq_ops = {
316 .start = rt_cpu_seq_start,
317 .next = rt_cpu_seq_next,
318 .stop = rt_cpu_seq_stop,
319 .show = rt_cpu_seq_show,
323 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
325 return seq_open(file, &rt_cpu_seq_ops);
328 static const struct file_operations rt_cpu_seq_fops = {
329 .owner = THIS_MODULE,
330 .open = rt_cpu_seq_open,
333 .release = seq_release,
336 #ifdef CONFIG_IP_ROUTE_CLASSID
337 static int rt_acct_proc_show(struct seq_file *m, void *v)
339 struct ip_rt_acct *dst, *src;
342 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
346 for_each_possible_cpu(i) {
347 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
348 for (j = 0; j < 256; j++) {
349 dst[j].o_bytes += src[j].o_bytes;
350 dst[j].o_packets += src[j].o_packets;
351 dst[j].i_bytes += src[j].i_bytes;
352 dst[j].i_packets += src[j].i_packets;
356 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
361 static int rt_acct_proc_open(struct inode *inode, struct file *file)
363 return single_open(file, rt_acct_proc_show, NULL);
366 static const struct file_operations rt_acct_proc_fops = {
367 .owner = THIS_MODULE,
368 .open = rt_acct_proc_open,
371 .release = single_release,
375 static int __net_init ip_rt_do_proc_init(struct net *net)
377 struct proc_dir_entry *pde;
379 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
384 pde = proc_create("rt_cache", S_IRUGO,
385 net->proc_net_stat, &rt_cpu_seq_fops);
389 #ifdef CONFIG_IP_ROUTE_CLASSID
390 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
396 #ifdef CONFIG_IP_ROUTE_CLASSID
398 remove_proc_entry("rt_cache", net->proc_net_stat);
401 remove_proc_entry("rt_cache", net->proc_net);
406 static void __net_exit ip_rt_do_proc_exit(struct net *net)
408 remove_proc_entry("rt_cache", net->proc_net_stat);
409 remove_proc_entry("rt_cache", net->proc_net);
410 #ifdef CONFIG_IP_ROUTE_CLASSID
411 remove_proc_entry("rt_acct", net->proc_net);
415 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
416 .init = ip_rt_do_proc_init,
417 .exit = ip_rt_do_proc_exit,
420 static int __init ip_rt_proc_init(void)
422 return register_pernet_subsys(&ip_rt_proc_ops);
426 static inline int ip_rt_proc_init(void)
430 #endif /* CONFIG_PROC_FS */
432 static inline bool rt_is_expired(const struct rtable *rth)
434 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
437 void rt_cache_flush(struct net *net)
439 rt_genid_bump_ipv4(net);
442 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
446 struct net_device *dev = dst->dev;
447 const __be32 *pkey = daddr;
448 const struct rtable *rt;
451 rt = (const struct rtable *) dst;
453 pkey = (const __be32 *) &rt->rt_gateway;
455 pkey = &ip_hdr(skb)->daddr;
457 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
460 return neigh_create(&arp_tbl, pkey, dev);
463 #define IP_IDENTS_SZ 2048u
465 static atomic_t *ip_idents __read_mostly;
466 static u32 *ip_tstamps __read_mostly;
468 /* In order to protect privacy, we add a perturbation to identifiers
469 * if one generator is seldom used. This makes hard for an attacker
470 * to infer how many packets were sent between two points in time.
472 u32 ip_idents_reserve(u32 hash, int segs)
474 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
475 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
476 u32 old = ACCESS_ONCE(*p_tstamp);
477 u32 now = (u32)jiffies;
480 if (old != now && cmpxchg(p_tstamp, old, now) == old)
481 delta = prandom_u32_max(now - old);
483 return atomic_add_return(segs + delta, p_id) - segs;
485 EXPORT_SYMBOL(ip_idents_reserve);
487 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
489 static u32 ip_idents_hashrnd __read_mostly;
492 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
494 hash = jhash_3words((__force u32)iph->daddr,
495 (__force u32)iph->saddr,
496 iph->protocol ^ net_hash_mix(net),
498 id = ip_idents_reserve(hash, segs);
501 EXPORT_SYMBOL(__ip_select_ident);
503 static void __build_flow_key(struct flowi4 *fl4, struct sock *sk,
504 const struct iphdr *iph,
506 u8 prot, u32 mark, int flow_flags)
509 const struct inet_sock *inet = inet_sk(sk);
511 oif = sk->sk_bound_dev_if;
513 tos = RT_CONN_FLAGS(sk);
514 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
516 flowi4_init_output(fl4, oif, mark, tos,
517 RT_SCOPE_UNIVERSE, prot,
519 iph->daddr, iph->saddr, 0, 0,
520 sk ? sock_i_uid(sk) : GLOBAL_ROOT_UID);
523 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
526 const struct iphdr *iph = ip_hdr(skb);
527 int oif = skb->dev->ifindex;
528 u8 tos = RT_TOS(iph->tos);
529 u8 prot = iph->protocol;
530 u32 mark = skb->mark;
532 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
535 static void build_sk_flow_key(struct flowi4 *fl4, struct sock *sk)
537 const struct inet_sock *inet = inet_sk(sk);
538 const struct ip_options_rcu *inet_opt;
539 __be32 daddr = inet->inet_daddr;
542 inet_opt = rcu_dereference(inet->inet_opt);
543 if (inet_opt && inet_opt->opt.srr)
544 daddr = inet_opt->opt.faddr;
545 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
546 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
547 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
548 inet_sk_flowi_flags(sk),
549 daddr, inet->inet_saddr, 0, 0,
554 static void ip_rt_build_flow_key(struct flowi4 *fl4, struct sock *sk,
555 const struct sk_buff *skb)
558 build_skb_flow_key(fl4, skb, sk);
560 build_sk_flow_key(fl4, sk);
563 static inline void rt_free(struct rtable *rt)
565 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
568 static DEFINE_SPINLOCK(fnhe_lock);
570 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
574 rt = rcu_dereference(fnhe->fnhe_rth_input);
576 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
579 rt = rcu_dereference(fnhe->fnhe_rth_output);
581 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
586 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
588 struct fib_nh_exception *fnhe, *oldest;
590 oldest = rcu_dereference(hash->chain);
591 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
592 fnhe = rcu_dereference(fnhe->fnhe_next)) {
593 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
596 fnhe_flush_routes(oldest);
600 static inline u32 fnhe_hashfun(__be32 daddr)
602 static u32 fnhe_hashrnd __read_mostly;
605 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
606 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
607 return hash_32(hval, FNHE_HASH_SHIFT);
610 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
612 rt->rt_pmtu = fnhe->fnhe_pmtu;
613 rt->dst.expires = fnhe->fnhe_expires;
616 rt->rt_flags |= RTCF_REDIRECTED;
617 rt->rt_gateway = fnhe->fnhe_gw;
618 rt->rt_uses_gateway = 1;
622 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
623 u32 pmtu, unsigned long expires)
625 struct fnhe_hash_bucket *hash;
626 struct fib_nh_exception *fnhe;
630 u32 hval = fnhe_hashfun(daddr);
632 spin_lock_bh(&fnhe_lock);
634 hash = rcu_dereference(nh->nh_exceptions);
636 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
639 rcu_assign_pointer(nh->nh_exceptions, hash);
645 for (fnhe = rcu_dereference(hash->chain); fnhe;
646 fnhe = rcu_dereference(fnhe->fnhe_next)) {
647 if (fnhe->fnhe_daddr == daddr)
656 fnhe->fnhe_pmtu = pmtu;
657 fnhe->fnhe_expires = max(1UL, expires);
659 /* Update all cached dsts too */
660 rt = rcu_dereference(fnhe->fnhe_rth_input);
662 fill_route_from_fnhe(rt, fnhe);
663 rt = rcu_dereference(fnhe->fnhe_rth_output);
665 fill_route_from_fnhe(rt, fnhe);
667 if (depth > FNHE_RECLAIM_DEPTH)
668 fnhe = fnhe_oldest(hash);
670 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
674 fnhe->fnhe_next = hash->chain;
675 rcu_assign_pointer(hash->chain, fnhe);
677 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
678 fnhe->fnhe_daddr = daddr;
680 fnhe->fnhe_pmtu = pmtu;
681 fnhe->fnhe_expires = expires;
683 /* Exception created; mark the cached routes for the nexthop
684 * stale, so anyone caching it rechecks if this exception
687 rt = rcu_dereference(nh->nh_rth_input);
689 rt->dst.obsolete = DST_OBSOLETE_KILL;
691 for_each_possible_cpu(i) {
692 struct rtable __rcu **prt;
693 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
694 rt = rcu_dereference(*prt);
696 rt->dst.obsolete = DST_OBSOLETE_KILL;
700 fnhe->fnhe_stamp = jiffies;
703 spin_unlock_bh(&fnhe_lock);
706 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
709 __be32 new_gw = icmp_hdr(skb)->un.gateway;
710 __be32 old_gw = ip_hdr(skb)->saddr;
711 struct net_device *dev = skb->dev;
712 struct in_device *in_dev;
713 struct fib_result res;
717 switch (icmp_hdr(skb)->code & 7) {
719 case ICMP_REDIR_NETTOS:
720 case ICMP_REDIR_HOST:
721 case ICMP_REDIR_HOSTTOS:
728 if (rt->rt_gateway != old_gw)
731 in_dev = __in_dev_get_rcu(dev);
736 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
737 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
738 ipv4_is_zeronet(new_gw))
739 goto reject_redirect;
741 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
742 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
743 goto reject_redirect;
744 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
745 goto reject_redirect;
747 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
748 goto reject_redirect;
751 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
753 if (!(n->nud_state & NUD_VALID)) {
754 neigh_event_send(n, NULL);
756 if (fib_lookup(net, fl4, &res, 0) == 0) {
757 struct fib_nh *nh = &FIB_RES_NH(res);
759 update_or_create_fnhe(nh, fl4->daddr, new_gw,
763 rt->dst.obsolete = DST_OBSOLETE_KILL;
764 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
771 #ifdef CONFIG_IP_ROUTE_VERBOSE
772 if (IN_DEV_LOG_MARTIANS(in_dev)) {
773 const struct iphdr *iph = (const struct iphdr *) skb->data;
774 __be32 daddr = iph->daddr;
775 __be32 saddr = iph->saddr;
777 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
778 " Advised path = %pI4 -> %pI4\n",
779 &old_gw, dev->name, &new_gw,
786 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
790 const struct iphdr *iph = (const struct iphdr *) skb->data;
791 int oif = skb->dev->ifindex;
792 u8 tos = RT_TOS(iph->tos);
793 u8 prot = iph->protocol;
794 u32 mark = skb->mark;
796 rt = (struct rtable *) dst;
798 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
799 __ip_do_redirect(rt, skb, &fl4, true);
802 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
804 struct rtable *rt = (struct rtable *)dst;
805 struct dst_entry *ret = dst;
808 if (dst->obsolete > 0) {
811 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
822 * 1. The first ip_rt_redirect_number redirects are sent
823 * with exponential backoff, then we stop sending them at all,
824 * assuming that the host ignores our redirects.
825 * 2. If we did not see packets requiring redirects
826 * during ip_rt_redirect_silence, we assume that the host
827 * forgot redirected route and start to send redirects again.
829 * This algorithm is much cheaper and more intelligent than dumb load limiting
832 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
833 * and "frag. need" (breaks PMTU discovery) in icmp.c.
836 void ip_rt_send_redirect(struct sk_buff *skb)
838 struct rtable *rt = skb_rtable(skb);
839 struct in_device *in_dev;
840 struct inet_peer *peer;
846 in_dev = __in_dev_get_rcu(rt->dst.dev);
847 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
851 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
852 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
855 net = dev_net(rt->dst.dev);
856 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
858 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
859 rt_nexthop(rt, ip_hdr(skb)->daddr));
863 /* No redirected packets during ip_rt_redirect_silence;
864 * reset the algorithm.
866 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
867 peer->rate_tokens = 0;
869 /* Too many ignored redirects; do not send anything
870 * set dst.rate_last to the last seen redirected packet.
872 if (peer->rate_tokens >= ip_rt_redirect_number) {
873 peer->rate_last = jiffies;
877 /* Check for load limit; set rate_last to the latest sent
880 if (peer->rate_tokens == 0 ||
883 (ip_rt_redirect_load << peer->rate_tokens)))) {
884 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
886 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
887 peer->rate_last = jiffies;
889 #ifdef CONFIG_IP_ROUTE_VERBOSE
891 peer->rate_tokens == ip_rt_redirect_number)
892 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
893 &ip_hdr(skb)->saddr, inet_iif(skb),
894 &ip_hdr(skb)->daddr, &gw);
901 static int ip_error(struct sk_buff *skb)
903 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
904 struct rtable *rt = skb_rtable(skb);
905 struct inet_peer *peer;
911 /* IP on this device is disabled. */
915 net = dev_net(rt->dst.dev);
916 if (!IN_DEV_FORWARD(in_dev)) {
917 switch (rt->dst.error) {
919 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
923 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
929 switch (rt->dst.error) {
934 code = ICMP_HOST_UNREACH;
937 code = ICMP_NET_UNREACH;
938 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
941 code = ICMP_PKT_FILTERED;
945 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
946 l3mdev_master_ifindex(skb->dev), 1);
951 peer->rate_tokens += now - peer->rate_last;
952 if (peer->rate_tokens > ip_rt_error_burst)
953 peer->rate_tokens = ip_rt_error_burst;
954 peer->rate_last = now;
955 if (peer->rate_tokens >= ip_rt_error_cost)
956 peer->rate_tokens -= ip_rt_error_cost;
962 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
968 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
970 struct dst_entry *dst = &rt->dst;
971 struct fib_result res;
973 if (dst_metric_locked(dst, RTAX_MTU))
976 if (ipv4_mtu(dst) < mtu)
979 if (mtu < ip_rt_min_pmtu)
980 mtu = ip_rt_min_pmtu;
982 if (rt->rt_pmtu == mtu &&
983 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
987 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
988 struct fib_nh *nh = &FIB_RES_NH(res);
990 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
991 jiffies + ip_rt_mtu_expires);
996 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
997 struct sk_buff *skb, u32 mtu)
999 struct rtable *rt = (struct rtable *) dst;
1002 ip_rt_build_flow_key(&fl4, sk, skb);
1003 __ip_rt_update_pmtu(rt, &fl4, mtu);
1006 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1007 int oif, u32 mark, u8 protocol, int flow_flags)
1009 const struct iphdr *iph = (const struct iphdr *) skb->data;
1014 mark = IP4_REPLY_MARK(net, skb->mark);
1016 __build_flow_key(&fl4, NULL, iph, oif,
1017 RT_TOS(iph->tos), protocol, mark, flow_flags);
1018 rt = __ip_route_output_key(net, &fl4);
1020 __ip_rt_update_pmtu(rt, &fl4, mtu);
1024 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1026 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1028 const struct iphdr *iph = (const struct iphdr *) skb->data;
1032 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1034 if (!fl4.flowi4_mark)
1035 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1037 rt = __ip_route_output_key(sock_net(sk), &fl4);
1039 __ip_rt_update_pmtu(rt, &fl4, mtu);
1044 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1046 const struct iphdr *iph = (const struct iphdr *) skb->data;
1049 struct dst_entry *odst = NULL;
1054 if (!ip_sk_accept_pmtu(sk))
1057 odst = sk_dst_get(sk);
1059 if (sock_owned_by_user(sk) || !odst) {
1060 __ipv4_sk_update_pmtu(skb, sk, mtu);
1064 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1066 rt = (struct rtable *)odst;
1067 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1068 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1075 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1077 if (!dst_check(&rt->dst, 0)) {
1079 dst_release(&rt->dst);
1081 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1089 sk_dst_set(sk, &rt->dst);
1095 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1097 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1098 int oif, u32 mark, u8 protocol, int flow_flags)
1100 const struct iphdr *iph = (const struct iphdr *) skb->data;
1104 __build_flow_key(&fl4, NULL, iph, oif,
1105 RT_TOS(iph->tos), protocol, mark, flow_flags);
1106 rt = __ip_route_output_key(net, &fl4);
1108 __ip_do_redirect(rt, skb, &fl4, false);
1112 EXPORT_SYMBOL_GPL(ipv4_redirect);
1114 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1116 const struct iphdr *iph = (const struct iphdr *) skb->data;
1120 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1121 rt = __ip_route_output_key(sock_net(sk), &fl4);
1123 __ip_do_redirect(rt, skb, &fl4, false);
1127 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1129 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1131 struct rtable *rt = (struct rtable *) dst;
1133 /* All IPV4 dsts are created with ->obsolete set to the value
1134 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1135 * into this function always.
1137 * When a PMTU/redirect information update invalidates a route,
1138 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1139 * DST_OBSOLETE_DEAD by dst_free().
1141 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1146 static void ipv4_link_failure(struct sk_buff *skb)
1150 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1152 rt = skb_rtable(skb);
1154 dst_set_expires(&rt->dst, 0);
1157 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1159 pr_debug("%s: %pI4 -> %pI4, %s\n",
1160 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1161 skb->dev ? skb->dev->name : "?");
1168 We do not cache source address of outgoing interface,
1169 because it is used only by IP RR, TS and SRR options,
1170 so that it out of fast path.
1172 BTW remember: "addr" is allowed to be not aligned
1176 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1180 if (rt_is_output_route(rt))
1181 src = ip_hdr(skb)->saddr;
1183 struct fib_result res;
1189 memset(&fl4, 0, sizeof(fl4));
1190 fl4.daddr = iph->daddr;
1191 fl4.saddr = iph->saddr;
1192 fl4.flowi4_tos = RT_TOS(iph->tos);
1193 fl4.flowi4_oif = rt->dst.dev->ifindex;
1194 fl4.flowi4_iif = skb->dev->ifindex;
1195 fl4.flowi4_mark = skb->mark;
1198 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1199 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1201 src = inet_select_addr(rt->dst.dev,
1202 rt_nexthop(rt, iph->daddr),
1206 memcpy(addr, &src, 4);
1209 #ifdef CONFIG_IP_ROUTE_CLASSID
1210 static void set_class_tag(struct rtable *rt, u32 tag)
1212 if (!(rt->dst.tclassid & 0xFFFF))
1213 rt->dst.tclassid |= tag & 0xFFFF;
1214 if (!(rt->dst.tclassid & 0xFFFF0000))
1215 rt->dst.tclassid |= tag & 0xFFFF0000;
1219 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1221 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1224 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1226 if (advmss > 65535 - 40)
1227 advmss = 65535 - 40;
1232 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1234 const struct rtable *rt = (const struct rtable *) dst;
1235 unsigned int mtu = rt->rt_pmtu;
1237 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1238 mtu = dst_metric_raw(dst, RTAX_MTU);
1243 mtu = dst->dev->mtu;
1245 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1246 if (rt->rt_uses_gateway && mtu > 576)
1250 return min_t(unsigned int, mtu, IP_MAX_MTU);
1253 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1255 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1256 struct fib_nh_exception *fnhe;
1262 hval = fnhe_hashfun(daddr);
1264 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1265 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1266 if (fnhe->fnhe_daddr == daddr)
1272 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1277 spin_lock_bh(&fnhe_lock);
1279 if (daddr == fnhe->fnhe_daddr) {
1280 struct rtable __rcu **porig;
1281 struct rtable *orig;
1282 int genid = fnhe_genid(dev_net(rt->dst.dev));
1284 if (rt_is_input_route(rt))
1285 porig = &fnhe->fnhe_rth_input;
1287 porig = &fnhe->fnhe_rth_output;
1288 orig = rcu_dereference(*porig);
1290 if (fnhe->fnhe_genid != genid) {
1291 fnhe->fnhe_genid = genid;
1293 fnhe->fnhe_pmtu = 0;
1294 fnhe->fnhe_expires = 0;
1295 fnhe_flush_routes(fnhe);
1298 fill_route_from_fnhe(rt, fnhe);
1299 if (!rt->rt_gateway)
1300 rt->rt_gateway = daddr;
1302 if (!(rt->dst.flags & DST_NOCACHE)) {
1303 rcu_assign_pointer(*porig, rt);
1309 fnhe->fnhe_stamp = jiffies;
1311 spin_unlock_bh(&fnhe_lock);
1316 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1318 struct rtable *orig, *prev, **p;
1321 if (rt_is_input_route(rt)) {
1322 p = (struct rtable **)&nh->nh_rth_input;
1324 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1328 prev = cmpxchg(p, orig, rt);
1338 struct uncached_list {
1340 struct list_head head;
1343 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1345 static void rt_add_uncached_list(struct rtable *rt)
1347 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1349 rt->rt_uncached_list = ul;
1351 spin_lock_bh(&ul->lock);
1352 list_add_tail(&rt->rt_uncached, &ul->head);
1353 spin_unlock_bh(&ul->lock);
1356 static void ipv4_dst_destroy(struct dst_entry *dst)
1358 struct rtable *rt = (struct rtable *) dst;
1360 if (!list_empty(&rt->rt_uncached)) {
1361 struct uncached_list *ul = rt->rt_uncached_list;
1363 spin_lock_bh(&ul->lock);
1364 list_del(&rt->rt_uncached);
1365 spin_unlock_bh(&ul->lock);
1369 void rt_flush_dev(struct net_device *dev)
1371 struct net *net = dev_net(dev);
1375 for_each_possible_cpu(cpu) {
1376 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1378 spin_lock_bh(&ul->lock);
1379 list_for_each_entry(rt, &ul->head, rt_uncached) {
1380 if (rt->dst.dev != dev)
1382 rt->dst.dev = net->loopback_dev;
1383 dev_hold(rt->dst.dev);
1386 spin_unlock_bh(&ul->lock);
1390 static bool rt_cache_valid(const struct rtable *rt)
1393 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1397 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1398 const struct fib_result *res,
1399 struct fib_nh_exception *fnhe,
1400 struct fib_info *fi, u16 type, u32 itag)
1402 bool cached = false;
1405 struct fib_nh *nh = &FIB_RES_NH(*res);
1407 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1408 rt->rt_gateway = nh->nh_gw;
1409 rt->rt_uses_gateway = 1;
1411 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1412 #ifdef CONFIG_IP_ROUTE_CLASSID
1413 rt->dst.tclassid = nh->nh_tclassid;
1415 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
1417 cached = rt_bind_exception(rt, fnhe, daddr);
1418 else if (!(rt->dst.flags & DST_NOCACHE))
1419 cached = rt_cache_route(nh, rt);
1420 if (unlikely(!cached)) {
1421 /* Routes we intend to cache in nexthop exception or
1422 * FIB nexthop have the DST_NOCACHE bit clear.
1423 * However, if we are unsuccessful at storing this
1424 * route into the cache we really need to set it.
1426 rt->dst.flags |= DST_NOCACHE;
1427 if (!rt->rt_gateway)
1428 rt->rt_gateway = daddr;
1429 rt_add_uncached_list(rt);
1432 rt_add_uncached_list(rt);
1434 #ifdef CONFIG_IP_ROUTE_CLASSID
1435 #ifdef CONFIG_IP_MULTIPLE_TABLES
1436 set_class_tag(rt, res->tclassid);
1438 set_class_tag(rt, itag);
1442 static struct rtable *rt_dst_alloc(struct net_device *dev,
1443 unsigned int flags, u16 type,
1444 bool nopolicy, bool noxfrm, bool will_cache)
1448 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1449 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1450 (nopolicy ? DST_NOPOLICY : 0) |
1451 (noxfrm ? DST_NOXFRM : 0));
1454 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1455 rt->rt_flags = flags;
1457 rt->rt_is_input = 0;
1461 rt->rt_uses_gateway = 0;
1462 rt->rt_table_id = 0;
1463 INIT_LIST_HEAD(&rt->rt_uncached);
1465 rt->dst.output = ip_output;
1466 if (flags & RTCF_LOCAL)
1467 rt->dst.input = ip_local_deliver;
1473 /* called in rcu_read_lock() section */
1474 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1475 u8 tos, struct net_device *dev, int our)
1478 struct in_device *in_dev = __in_dev_get_rcu(dev);
1479 unsigned int flags = RTCF_MULTICAST;
1483 /* Primary sanity checks. */
1488 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1489 skb->protocol != htons(ETH_P_IP))
1492 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1495 if (ipv4_is_zeronet(saddr)) {
1496 if (!ipv4_is_local_multicast(daddr))
1499 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1505 flags |= RTCF_LOCAL;
1507 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1508 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1512 #ifdef CONFIG_IP_ROUTE_CLASSID
1513 rth->dst.tclassid = itag;
1515 rth->dst.output = ip_rt_bug;
1516 rth->rt_is_input= 1;
1518 #ifdef CONFIG_IP_MROUTE
1519 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1520 rth->dst.input = ip_mr_input;
1522 RT_CACHE_STAT_INC(in_slow_mc);
1524 skb_dst_set(skb, &rth->dst);
1536 static void ip_handle_martian_source(struct net_device *dev,
1537 struct in_device *in_dev,
1538 struct sk_buff *skb,
1542 RT_CACHE_STAT_INC(in_martian_src);
1543 #ifdef CONFIG_IP_ROUTE_VERBOSE
1544 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1546 * RFC1812 recommendation, if source is martian,
1547 * the only hint is MAC header.
1549 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1550 &daddr, &saddr, dev->name);
1551 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1552 print_hex_dump(KERN_WARNING, "ll header: ",
1553 DUMP_PREFIX_OFFSET, 16, 1,
1554 skb_mac_header(skb),
1555 dev->hard_header_len, true);
1561 /* called in rcu_read_lock() section */
1562 static int __mkroute_input(struct sk_buff *skb,
1563 const struct fib_result *res,
1564 struct in_device *in_dev,
1565 __be32 daddr, __be32 saddr, u32 tos)
1567 struct fib_nh_exception *fnhe;
1570 struct in_device *out_dev;
1574 /* get a working reference to the output device */
1575 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1577 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1581 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1582 in_dev->dev, in_dev, &itag);
1584 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1590 do_cache = res->fi && !itag;
1591 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1592 skb->protocol == htons(ETH_P_IP) &&
1593 (IN_DEV_SHARED_MEDIA(out_dev) ||
1594 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1595 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1597 if (skb->protocol != htons(ETH_P_IP)) {
1598 /* Not IP (i.e. ARP). Do not create route, if it is
1599 * invalid for proxy arp. DNAT routes are always valid.
1601 * Proxy arp feature have been extended to allow, ARP
1602 * replies back to the same interface, to support
1603 * Private VLAN switch technologies. See arp.c.
1605 if (out_dev == in_dev &&
1606 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1612 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1615 rth = rcu_dereference(fnhe->fnhe_rth_input);
1617 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1619 if (rt_cache_valid(rth)) {
1620 skb_dst_set_noref(skb, &rth->dst);
1625 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1626 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1627 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1633 rth->rt_is_input = 1;
1635 rth->rt_table_id = res->table->tb_id;
1636 RT_CACHE_STAT_INC(in_slow_tot);
1638 rth->dst.input = ip_forward;
1640 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1641 if (lwtunnel_output_redirect(rth->dst.lwtstate)) {
1642 rth->dst.lwtstate->orig_output = rth->dst.output;
1643 rth->dst.output = lwtunnel_output;
1645 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
1646 rth->dst.lwtstate->orig_input = rth->dst.input;
1647 rth->dst.input = lwtunnel_input;
1649 skb_dst_set(skb, &rth->dst);
1656 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1658 /* To make ICMP packets follow the right flow, the multipath hash is
1659 * calculated from the inner IP addresses in reverse order.
1661 static int ip_multipath_icmp_hash(struct sk_buff *skb)
1663 const struct iphdr *outer_iph = ip_hdr(skb);
1664 struct icmphdr _icmph;
1665 const struct icmphdr *icmph;
1666 struct iphdr _inner_iph;
1667 const struct iphdr *inner_iph;
1669 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1672 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1677 if (icmph->type != ICMP_DEST_UNREACH &&
1678 icmph->type != ICMP_REDIRECT &&
1679 icmph->type != ICMP_TIME_EXCEEDED &&
1680 icmph->type != ICMP_PARAMETERPROB) {
1684 inner_iph = skb_header_pointer(skb,
1685 outer_iph->ihl * 4 + sizeof(_icmph),
1686 sizeof(_inner_iph), &_inner_iph);
1690 return fib_multipath_hash(inner_iph->daddr, inner_iph->saddr);
1693 return fib_multipath_hash(outer_iph->saddr, outer_iph->daddr);
1696 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
1698 static int ip_mkroute_input(struct sk_buff *skb,
1699 struct fib_result *res,
1700 const struct flowi4 *fl4,
1701 struct in_device *in_dev,
1702 __be32 daddr, __be32 saddr, u32 tos)
1704 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1705 if (res->fi && res->fi->fib_nhs > 1) {
1708 if (unlikely(ip_hdr(skb)->protocol == IPPROTO_ICMP))
1709 h = ip_multipath_icmp_hash(skb);
1711 h = fib_multipath_hash(saddr, daddr);
1712 fib_select_multipath(res, h);
1716 /* create a routing cache entry */
1717 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1721 * NOTE. We drop all the packets that has local source
1722 * addresses, because every properly looped back packet
1723 * must have correct destination already attached by output routine.
1725 * Such approach solves two big problems:
1726 * 1. Not simplex devices are handled properly.
1727 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1728 * called with rcu_read_lock()
1731 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1732 u8 tos, struct net_device *dev)
1734 struct fib_result res;
1735 struct in_device *in_dev = __in_dev_get_rcu(dev);
1736 struct ip_tunnel_info *tun_info;
1738 unsigned int flags = 0;
1742 struct net *net = dev_net(dev);
1745 /* IP on this device is disabled. */
1750 /* Check for the most weird martians, which can be not detected
1754 tun_info = skb_tunnel_info(skb);
1755 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
1756 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
1758 fl4.flowi4_tun_key.tun_id = 0;
1761 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1762 goto martian_source;
1766 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1769 /* Accept zero addresses only to limited broadcast;
1770 * I even do not know to fix it or not. Waiting for complains :-)
1772 if (ipv4_is_zeronet(saddr))
1773 goto martian_source;
1775 if (ipv4_is_zeronet(daddr))
1776 goto martian_destination;
1778 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1779 * and call it once if daddr or/and saddr are loopback addresses
1781 if (ipv4_is_loopback(daddr)) {
1782 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1783 goto martian_destination;
1784 } else if (ipv4_is_loopback(saddr)) {
1785 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1786 goto martian_source;
1790 * Now we are ready to route packet.
1793 fl4.flowi4_iif = l3mdev_fib_oif_rcu(dev);
1794 fl4.flowi4_mark = skb->mark;
1795 fl4.flowi4_tos = tos;
1796 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1797 fl4.flowi4_flags = 0;
1800 err = fib_lookup(net, &fl4, &res, 0);
1802 if (!IN_DEV_FORWARD(in_dev))
1803 err = -EHOSTUNREACH;
1807 if (res.type == RTN_BROADCAST)
1810 if (res.type == RTN_LOCAL) {
1811 err = fib_validate_source(skb, saddr, daddr, tos,
1812 0, dev, in_dev, &itag);
1814 goto martian_source;
1818 if (!IN_DEV_FORWARD(in_dev)) {
1819 err = -EHOSTUNREACH;
1822 if (res.type != RTN_UNICAST)
1823 goto martian_destination;
1825 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1829 if (skb->protocol != htons(ETH_P_IP))
1832 if (!ipv4_is_zeronet(saddr)) {
1833 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1836 goto martian_source;
1838 flags |= RTCF_BROADCAST;
1839 res.type = RTN_BROADCAST;
1840 RT_CACHE_STAT_INC(in_brd);
1846 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1847 if (rt_cache_valid(rth)) {
1848 skb_dst_set_noref(skb, &rth->dst);
1856 rth = rt_dst_alloc(net->loopback_dev, flags | RTCF_LOCAL, res.type,
1857 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1861 rth->dst.output= ip_rt_bug;
1862 #ifdef CONFIG_IP_ROUTE_CLASSID
1863 rth->dst.tclassid = itag;
1865 rth->rt_is_input = 1;
1867 rth->rt_table_id = res.table->tb_id;
1869 RT_CACHE_STAT_INC(in_slow_tot);
1870 if (res.type == RTN_UNREACHABLE) {
1871 rth->dst.input= ip_error;
1872 rth->dst.error= -err;
1873 rth->rt_flags &= ~RTCF_LOCAL;
1876 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1877 rth->dst.flags |= DST_NOCACHE;
1878 rt_add_uncached_list(rth);
1881 skb_dst_set(skb, &rth->dst);
1886 RT_CACHE_STAT_INC(in_no_route);
1887 res.type = RTN_UNREACHABLE;
1893 * Do not cache martian addresses: they should be logged (RFC1812)
1895 martian_destination:
1896 RT_CACHE_STAT_INC(in_martian_dst);
1897 #ifdef CONFIG_IP_ROUTE_VERBOSE
1898 if (IN_DEV_LOG_MARTIANS(in_dev))
1899 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1900 &daddr, &saddr, dev->name);
1912 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1916 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1917 u8 tos, struct net_device *dev)
1923 /* Multicast recognition logic is moved from route cache to here.
1924 The problem was that too many Ethernet cards have broken/missing
1925 hardware multicast filters :-( As result the host on multicasting
1926 network acquires a lot of useless route cache entries, sort of
1927 SDR messages from all the world. Now we try to get rid of them.
1928 Really, provided software IP multicast filter is organized
1929 reasonably (at least, hashed), it does not result in a slowdown
1930 comparing with route cache reject entries.
1931 Note, that multicast routers are not affected, because
1932 route cache entry is created eventually.
1934 if (ipv4_is_multicast(daddr)) {
1935 struct in_device *in_dev = __in_dev_get_rcu(dev);
1938 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1939 ip_hdr(skb)->protocol);
1941 #ifdef CONFIG_IP_MROUTE
1943 (!ipv4_is_local_multicast(daddr) &&
1944 IN_DEV_MFORWARD(in_dev))
1947 int res = ip_route_input_mc(skb, daddr, saddr,
1956 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1960 EXPORT_SYMBOL(ip_route_input_noref);
1962 /* called with rcu_read_lock() */
1963 static struct rtable *__mkroute_output(const struct fib_result *res,
1964 const struct flowi4 *fl4, int orig_oif,
1965 struct net_device *dev_out,
1968 struct fib_info *fi = res->fi;
1969 struct fib_nh_exception *fnhe;
1970 struct in_device *in_dev;
1971 u16 type = res->type;
1975 in_dev = __in_dev_get_rcu(dev_out);
1977 return ERR_PTR(-EINVAL);
1979 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1980 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1981 return ERR_PTR(-EINVAL);
1983 if (ipv4_is_lbcast(fl4->daddr))
1984 type = RTN_BROADCAST;
1985 else if (ipv4_is_multicast(fl4->daddr))
1986 type = RTN_MULTICAST;
1987 else if (ipv4_is_zeronet(fl4->daddr))
1988 return ERR_PTR(-EINVAL);
1990 if (dev_out->flags & IFF_LOOPBACK)
1991 flags |= RTCF_LOCAL;
1994 if (type == RTN_BROADCAST) {
1995 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1997 } else if (type == RTN_MULTICAST) {
1998 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1999 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2001 flags &= ~RTCF_LOCAL;
2004 /* If multicast route do not exist use
2005 * default one, but do not gateway in this case.
2008 if (fi && res->prefixlen < 4)
2013 do_cache &= fi != NULL;
2015 struct rtable __rcu **prth;
2016 struct fib_nh *nh = &FIB_RES_NH(*res);
2018 fnhe = find_exception(nh, fl4->daddr);
2020 prth = &fnhe->fnhe_rth_output;
2022 if (unlikely(fl4->flowi4_flags &
2023 FLOWI_FLAG_KNOWN_NH &&
2025 nh->nh_scope == RT_SCOPE_LINK))) {
2029 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
2031 rth = rcu_dereference(*prth);
2032 if (rt_cache_valid(rth)) {
2033 dst_hold(&rth->dst);
2039 rth = rt_dst_alloc(dev_out, flags, type,
2040 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2041 IN_DEV_CONF_GET(in_dev, NOXFRM),
2044 return ERR_PTR(-ENOBUFS);
2046 rth->rt_iif = orig_oif ? : 0;
2048 rth->rt_table_id = res->table->tb_id;
2050 RT_CACHE_STAT_INC(out_slow_tot);
2052 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2053 if (flags & RTCF_LOCAL &&
2054 !(dev_out->flags & IFF_LOOPBACK)) {
2055 rth->dst.output = ip_mc_output;
2056 RT_CACHE_STAT_INC(out_slow_mc);
2058 #ifdef CONFIG_IP_MROUTE
2059 if (type == RTN_MULTICAST) {
2060 if (IN_DEV_MFORWARD(in_dev) &&
2061 !ipv4_is_local_multicast(fl4->daddr)) {
2062 rth->dst.input = ip_mr_input;
2063 rth->dst.output = ip_mc_output;
2069 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
2070 if (lwtunnel_output_redirect(rth->dst.lwtstate))
2071 rth->dst.output = lwtunnel_output;
2077 * Major route resolver routine.
2080 struct rtable *__ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2083 struct net_device *dev_out = NULL;
2084 __u8 tos = RT_FL_TOS(fl4);
2085 unsigned int flags = 0;
2086 struct fib_result res;
2089 int err = -ENETUNREACH;
2095 orig_oif = fl4->flowi4_oif;
2097 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2098 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2099 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2100 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2104 rth = ERR_PTR(-EINVAL);
2105 if (ipv4_is_multicast(fl4->saddr) ||
2106 ipv4_is_lbcast(fl4->saddr) ||
2107 ipv4_is_zeronet(fl4->saddr))
2110 /* I removed check for oif == dev_out->oif here.
2111 It was wrong for two reasons:
2112 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2113 is assigned to multiple interfaces.
2114 2. Moreover, we are allowed to send packets with saddr
2115 of another iface. --ANK
2118 if (fl4->flowi4_oif == 0 &&
2119 (ipv4_is_multicast(fl4->daddr) ||
2120 ipv4_is_lbcast(fl4->daddr))) {
2121 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2122 dev_out = __ip_dev_find(net, fl4->saddr, false);
2126 /* Special hack: user can direct multicasts
2127 and limited broadcast via necessary interface
2128 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2129 This hack is not just for fun, it allows
2130 vic,vat and friends to work.
2131 They bind socket to loopback, set ttl to zero
2132 and expect that it will work.
2133 From the viewpoint of routing cache they are broken,
2134 because we are not allowed to build multicast path
2135 with loopback source addr (look, routing cache
2136 cannot know, that ttl is zero, so that packet
2137 will not leave this host and route is valid).
2138 Luckily, this hack is good workaround.
2141 fl4->flowi4_oif = dev_out->ifindex;
2145 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2146 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2147 if (!__ip_dev_find(net, fl4->saddr, false))
2153 if (fl4->flowi4_oif) {
2154 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2155 rth = ERR_PTR(-ENODEV);
2159 /* RACE: Check return value of inet_select_addr instead. */
2160 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2161 rth = ERR_PTR(-ENETUNREACH);
2164 if (ipv4_is_local_multicast(fl4->daddr) ||
2165 ipv4_is_lbcast(fl4->daddr) ||
2166 fl4->flowi4_proto == IPPROTO_IGMP) {
2168 fl4->saddr = inet_select_addr(dev_out, 0,
2173 if (ipv4_is_multicast(fl4->daddr))
2174 fl4->saddr = inet_select_addr(dev_out, 0,
2176 else if (!fl4->daddr)
2177 fl4->saddr = inet_select_addr(dev_out, 0,
2181 rth = l3mdev_get_rtable(dev_out, fl4);
2187 fl4->daddr = fl4->saddr;
2189 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2190 dev_out = net->loopback_dev;
2191 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2192 res.type = RTN_LOCAL;
2193 flags |= RTCF_LOCAL;
2197 err = fib_lookup(net, fl4, &res, 0);
2201 if (fl4->flowi4_oif &&
2202 !netif_index_is_l3_master(net, fl4->flowi4_oif)) {
2203 /* Apparently, routing tables are wrong. Assume,
2204 that the destination is on link.
2207 Because we are allowed to send to iface
2208 even if it has NO routes and NO assigned
2209 addresses. When oif is specified, routing
2210 tables are looked up with only one purpose:
2211 to catch if destination is gatewayed, rather than
2212 direct. Moreover, if MSG_DONTROUTE is set,
2213 we send packet, ignoring both routing tables
2214 and ifaddr state. --ANK
2217 We could make it even if oif is unknown,
2218 likely IPv6, but we do not.
2221 if (fl4->saddr == 0)
2222 fl4->saddr = inet_select_addr(dev_out, 0,
2224 res.type = RTN_UNICAST;
2231 if (res.type == RTN_LOCAL) {
2233 if (res.fi->fib_prefsrc)
2234 fl4->saddr = res.fi->fib_prefsrc;
2236 fl4->saddr = fl4->daddr;
2238 dev_out = net->loopback_dev;
2239 fl4->flowi4_oif = dev_out->ifindex;
2240 flags |= RTCF_LOCAL;
2244 fib_select_path(net, &res, fl4, mp_hash);
2246 dev_out = FIB_RES_DEV(res);
2247 fl4->flowi4_oif = dev_out->ifindex;
2251 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2257 EXPORT_SYMBOL_GPL(__ip_route_output_key_hash);
2259 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2264 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2266 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2268 return mtu ? : dst->dev->mtu;
2271 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2272 struct sk_buff *skb, u32 mtu)
2276 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2277 struct sk_buff *skb)
2281 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2287 static struct dst_ops ipv4_dst_blackhole_ops = {
2289 .check = ipv4_blackhole_dst_check,
2290 .mtu = ipv4_blackhole_mtu,
2291 .default_advmss = ipv4_default_advmss,
2292 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2293 .redirect = ipv4_rt_blackhole_redirect,
2294 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2295 .neigh_lookup = ipv4_neigh_lookup,
2298 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2300 struct rtable *ort = (struct rtable *) dst_orig;
2303 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2305 struct dst_entry *new = &rt->dst;
2308 new->input = dst_discard;
2309 new->output = dst_discard_out;
2311 new->dev = ort->dst.dev;
2315 rt->rt_is_input = ort->rt_is_input;
2316 rt->rt_iif = ort->rt_iif;
2317 rt->rt_pmtu = ort->rt_pmtu;
2319 rt->rt_genid = rt_genid_ipv4(net);
2320 rt->rt_flags = ort->rt_flags;
2321 rt->rt_type = ort->rt_type;
2322 rt->rt_gateway = ort->rt_gateway;
2323 rt->rt_uses_gateway = ort->rt_uses_gateway;
2325 INIT_LIST_HEAD(&rt->rt_uncached);
2329 dst_release(dst_orig);
2331 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2334 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2335 const struct sock *sk)
2337 struct rtable *rt = __ip_route_output_key(net, flp4);
2342 if (flp4->flowi4_proto)
2343 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2344 flowi4_to_flowi(flp4),
2349 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2351 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, u32 table_id,
2352 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2353 u32 seq, int event, int nowait, unsigned int flags)
2355 struct rtable *rt = skb_rtable(skb);
2357 struct nlmsghdr *nlh;
2358 unsigned long expires = 0;
2360 u32 metrics[RTAX_MAX];
2362 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2366 r = nlmsg_data(nlh);
2367 r->rtm_family = AF_INET;
2368 r->rtm_dst_len = 32;
2370 r->rtm_tos = fl4->flowi4_tos;
2371 r->rtm_table = table_id;
2372 if (nla_put_u32(skb, RTA_TABLE, table_id))
2373 goto nla_put_failure;
2374 r->rtm_type = rt->rt_type;
2375 r->rtm_scope = RT_SCOPE_UNIVERSE;
2376 r->rtm_protocol = RTPROT_UNSPEC;
2377 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2378 if (rt->rt_flags & RTCF_NOTIFY)
2379 r->rtm_flags |= RTM_F_NOTIFY;
2380 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2381 r->rtm_flags |= RTCF_DOREDIRECT;
2383 if (nla_put_in_addr(skb, RTA_DST, dst))
2384 goto nla_put_failure;
2386 r->rtm_src_len = 32;
2387 if (nla_put_in_addr(skb, RTA_SRC, src))
2388 goto nla_put_failure;
2391 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2392 goto nla_put_failure;
2393 #ifdef CONFIG_IP_ROUTE_CLASSID
2394 if (rt->dst.tclassid &&
2395 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2396 goto nla_put_failure;
2398 if (!rt_is_input_route(rt) &&
2399 fl4->saddr != src) {
2400 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2401 goto nla_put_failure;
2403 if (rt->rt_uses_gateway &&
2404 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2405 goto nla_put_failure;
2407 expires = rt->dst.expires;
2409 unsigned long now = jiffies;
2411 if (time_before(now, expires))
2417 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2418 if (rt->rt_pmtu && expires)
2419 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2420 if (rtnetlink_put_metrics(skb, metrics) < 0)
2421 goto nla_put_failure;
2423 if (fl4->flowi4_mark &&
2424 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2425 goto nla_put_failure;
2427 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
2428 nla_put_u32(skb, RTA_UID,
2429 from_kuid_munged(current_user_ns(), fl4->flowi4_uid)))
2430 goto nla_put_failure;
2432 error = rt->dst.error;
2434 if (rt_is_input_route(rt)) {
2435 #ifdef CONFIG_IP_MROUTE
2436 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2437 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2438 int err = ipmr_get_route(net, skb,
2439 fl4->saddr, fl4->daddr,
2445 goto nla_put_failure;
2447 if (err == -EMSGSIZE)
2448 goto nla_put_failure;
2454 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2455 goto nla_put_failure;
2458 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2459 goto nla_put_failure;
2461 nlmsg_end(skb, nlh);
2465 nlmsg_cancel(skb, nlh);
2469 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2471 struct net *net = sock_net(in_skb->sk);
2473 struct nlattr *tb[RTA_MAX+1];
2474 struct rtable *rt = NULL;
2481 struct sk_buff *skb;
2482 u32 table_id = RT_TABLE_MAIN;
2485 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2489 rtm = nlmsg_data(nlh);
2491 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2497 /* Reserve room for dummy headers, this skb can pass
2498 through good chunk of routing engine.
2500 skb_reset_mac_header(skb);
2501 skb_reset_network_header(skb);
2503 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2504 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2505 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2507 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2508 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2509 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2510 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2512 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
2514 uid = (iif ? INVALID_UID : current_uid());
2516 memset(&fl4, 0, sizeof(fl4));
2519 fl4.flowi4_tos = rtm->rtm_tos;
2520 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2521 fl4.flowi4_mark = mark;
2522 fl4.flowi4_uid = uid;
2524 if (netif_index_is_l3_master(net, fl4.flowi4_oif))
2525 fl4.flowi4_flags = FLOWI_FLAG_L3MDEV_SRC | FLOWI_FLAG_SKIP_NH_OIF;
2528 struct net_device *dev;
2530 dev = __dev_get_by_index(net, iif);
2536 skb->protocol = htons(ETH_P_IP);
2540 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2543 rt = skb_rtable(skb);
2544 if (err == 0 && rt->dst.error)
2545 err = -rt->dst.error;
2547 rt = ip_route_output_key(net, &fl4);
2557 skb_dst_set(skb, &rt->dst);
2558 if (rtm->rtm_flags & RTM_F_NOTIFY)
2559 rt->rt_flags |= RTCF_NOTIFY;
2561 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
2562 table_id = rt->rt_table_id;
2564 err = rt_fill_info(net, dst, src, table_id, &fl4, skb,
2565 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2566 RTM_NEWROUTE, 0, 0);
2570 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2579 void ip_rt_multicast_event(struct in_device *in_dev)
2581 rt_cache_flush(dev_net(in_dev->dev));
2584 #ifdef CONFIG_SYSCTL
2585 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2586 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2587 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2588 static int ip_rt_gc_elasticity __read_mostly = 8;
2590 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2591 void __user *buffer,
2592 size_t *lenp, loff_t *ppos)
2594 struct net *net = (struct net *)__ctl->extra1;
2597 rt_cache_flush(net);
2598 fnhe_genid_bump(net);
2605 static struct ctl_table ipv4_route_table[] = {
2607 .procname = "gc_thresh",
2608 .data = &ipv4_dst_ops.gc_thresh,
2609 .maxlen = sizeof(int),
2611 .proc_handler = proc_dointvec,
2614 .procname = "max_size",
2615 .data = &ip_rt_max_size,
2616 .maxlen = sizeof(int),
2618 .proc_handler = proc_dointvec,
2621 /* Deprecated. Use gc_min_interval_ms */
2623 .procname = "gc_min_interval",
2624 .data = &ip_rt_gc_min_interval,
2625 .maxlen = sizeof(int),
2627 .proc_handler = proc_dointvec_jiffies,
2630 .procname = "gc_min_interval_ms",
2631 .data = &ip_rt_gc_min_interval,
2632 .maxlen = sizeof(int),
2634 .proc_handler = proc_dointvec_ms_jiffies,
2637 .procname = "gc_timeout",
2638 .data = &ip_rt_gc_timeout,
2639 .maxlen = sizeof(int),
2641 .proc_handler = proc_dointvec_jiffies,
2644 .procname = "gc_interval",
2645 .data = &ip_rt_gc_interval,
2646 .maxlen = sizeof(int),
2648 .proc_handler = proc_dointvec_jiffies,
2651 .procname = "redirect_load",
2652 .data = &ip_rt_redirect_load,
2653 .maxlen = sizeof(int),
2655 .proc_handler = proc_dointvec,
2658 .procname = "redirect_number",
2659 .data = &ip_rt_redirect_number,
2660 .maxlen = sizeof(int),
2662 .proc_handler = proc_dointvec,
2665 .procname = "redirect_silence",
2666 .data = &ip_rt_redirect_silence,
2667 .maxlen = sizeof(int),
2669 .proc_handler = proc_dointvec,
2672 .procname = "error_cost",
2673 .data = &ip_rt_error_cost,
2674 .maxlen = sizeof(int),
2676 .proc_handler = proc_dointvec,
2679 .procname = "error_burst",
2680 .data = &ip_rt_error_burst,
2681 .maxlen = sizeof(int),
2683 .proc_handler = proc_dointvec,
2686 .procname = "gc_elasticity",
2687 .data = &ip_rt_gc_elasticity,
2688 .maxlen = sizeof(int),
2690 .proc_handler = proc_dointvec,
2693 .procname = "mtu_expires",
2694 .data = &ip_rt_mtu_expires,
2695 .maxlen = sizeof(int),
2697 .proc_handler = proc_dointvec_jiffies,
2700 .procname = "min_pmtu",
2701 .data = &ip_rt_min_pmtu,
2702 .maxlen = sizeof(int),
2704 .proc_handler = proc_dointvec,
2707 .procname = "min_adv_mss",
2708 .data = &ip_rt_min_advmss,
2709 .maxlen = sizeof(int),
2711 .proc_handler = proc_dointvec,
2716 static struct ctl_table ipv4_route_flush_table[] = {
2718 .procname = "flush",
2719 .maxlen = sizeof(int),
2721 .proc_handler = ipv4_sysctl_rtcache_flush,
2726 static __net_init int sysctl_route_net_init(struct net *net)
2728 struct ctl_table *tbl;
2730 tbl = ipv4_route_flush_table;
2731 if (!net_eq(net, &init_net)) {
2732 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2736 /* Don't export sysctls to unprivileged users */
2737 if (net->user_ns != &init_user_ns)
2738 tbl[0].procname = NULL;
2740 tbl[0].extra1 = net;
2742 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2743 if (!net->ipv4.route_hdr)
2748 if (tbl != ipv4_route_flush_table)
2754 static __net_exit void sysctl_route_net_exit(struct net *net)
2756 struct ctl_table *tbl;
2758 tbl = net->ipv4.route_hdr->ctl_table_arg;
2759 unregister_net_sysctl_table(net->ipv4.route_hdr);
2760 BUG_ON(tbl == ipv4_route_flush_table);
2764 static __net_initdata struct pernet_operations sysctl_route_ops = {
2765 .init = sysctl_route_net_init,
2766 .exit = sysctl_route_net_exit,
2770 static __net_init int rt_genid_init(struct net *net)
2772 atomic_set(&net->ipv4.rt_genid, 0);
2773 atomic_set(&net->fnhe_genid, 0);
2774 get_random_bytes(&net->ipv4.dev_addr_genid,
2775 sizeof(net->ipv4.dev_addr_genid));
2779 static __net_initdata struct pernet_operations rt_genid_ops = {
2780 .init = rt_genid_init,
2783 static int __net_init ipv4_inetpeer_init(struct net *net)
2785 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2789 inet_peer_base_init(bp);
2790 net->ipv4.peers = bp;
2794 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2796 struct inet_peer_base *bp = net->ipv4.peers;
2798 net->ipv4.peers = NULL;
2799 inetpeer_invalidate_tree(bp);
2803 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2804 .init = ipv4_inetpeer_init,
2805 .exit = ipv4_inetpeer_exit,
2808 #ifdef CONFIG_IP_ROUTE_CLASSID
2809 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2810 #endif /* CONFIG_IP_ROUTE_CLASSID */
2812 int __init ip_rt_init(void)
2817 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2819 panic("IP: failed to allocate ip_idents\n");
2821 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2823 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
2825 panic("IP: failed to allocate ip_tstamps\n");
2827 for_each_possible_cpu(cpu) {
2828 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
2830 INIT_LIST_HEAD(&ul->head);
2831 spin_lock_init(&ul->lock);
2833 #ifdef CONFIG_IP_ROUTE_CLASSID
2834 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2836 panic("IP: failed to allocate ip_rt_acct\n");
2839 ipv4_dst_ops.kmem_cachep =
2840 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2841 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2843 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2845 if (dst_entries_init(&ipv4_dst_ops) < 0)
2846 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2848 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2849 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2851 ipv4_dst_ops.gc_thresh = ~0;
2852 ip_rt_max_size = INT_MAX;
2857 if (ip_rt_proc_init())
2858 pr_err("Unable to create route proc files\n");
2863 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2865 #ifdef CONFIG_SYSCTL
2866 register_pernet_subsys(&sysctl_route_ops);
2868 register_pernet_subsys(&rt_genid_ops);
2869 register_pernet_subsys(&ipv4_inetpeer_ops);
2873 #ifdef CONFIG_SYSCTL
2875 * We really need to sanitize the damn ipv4 init order, then all
2876 * this nonsense will go away.
2878 void __init ip_static_sysctl_init(void)
2880 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);