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65#define pr_fmt(fmt) "IPv4: " fmt
66
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>
72#include <linux/mm.h>
73#include <linux/string.h>
74#include <linux/socket.h>
75#include <linux/sockios.h>
76#include <linux/errno.h>
77#include <linux/in.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>
93#include <net/dst.h>
94#include <net/net_namespace.h>
95#include <net/protocol.h>
96#include <net/ip.h>
97#include <net/route.h>
98#include <net/inetpeer.h>
99#include <net/sock.h>
100#include <net/ip_fib.h>
101#include <net/arp.h>
102#include <net/tcp.h>
103#include <net/icmp.h>
104#include <net/xfrm.h>
105#include <net/netevent.h>
106#include <net/rtnetlink.h>
107#ifdef CONFIG_SYSCTL
108#include <linux/sysctl.h>
109#include <linux/kmemleak.h>
110#endif
111#include <net/secure_seq.h>
112
113#define RT_FL_TOS(oldflp4) \
114 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
115
116#define RT_GC_TIMEOUT (300*HZ)
117
118static int ip_rt_max_size;
119static int ip_rt_redirect_number __read_mostly = 9;
120static int ip_rt_redirect_load __read_mostly = HZ / 50;
121static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
122static int ip_rt_error_cost __read_mostly = HZ;
123static int ip_rt_error_burst __read_mostly = 5 * HZ;
124static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
125static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
126static int ip_rt_min_advmss __read_mostly = 256;
127
128
129
130
131
132static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
133static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
134static unsigned int ipv4_mtu(const struct dst_entry *dst);
135static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
136static void ipv4_link_failure(struct sk_buff *skb);
137static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
138 struct sk_buff *skb, u32 mtu);
139static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
140 struct sk_buff *skb);
141static void ipv4_dst_destroy(struct dst_entry *dst);
142
143static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
144{
145 WARN_ON(1);
146 return NULL;
147}
148
149static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
150 struct sk_buff *skb,
151 const void *daddr);
152
153static struct dst_ops ipv4_dst_ops = {
154 .family = AF_INET,
155 .check = ipv4_dst_check,
156 .default_advmss = ipv4_default_advmss,
157 .mtu = ipv4_mtu,
158 .cow_metrics = ipv4_cow_metrics,
159 .destroy = ipv4_dst_destroy,
160 .negative_advice = ipv4_negative_advice,
161 .link_failure = ipv4_link_failure,
162 .update_pmtu = ip_rt_update_pmtu,
163 .redirect = ip_do_redirect,
164 .local_out = __ip_local_out,
165 .neigh_lookup = ipv4_neigh_lookup,
166};
167
168#define ECN_OR_COST(class) TC_PRIO_##class
169
170const __u8 ip_tos2prio[16] = {
171 TC_PRIO_BESTEFFORT,
172 ECN_OR_COST(BESTEFFORT),
173 TC_PRIO_BESTEFFORT,
174 ECN_OR_COST(BESTEFFORT),
175 TC_PRIO_BULK,
176 ECN_OR_COST(BULK),
177 TC_PRIO_BULK,
178 ECN_OR_COST(BULK),
179 TC_PRIO_INTERACTIVE,
180 ECN_OR_COST(INTERACTIVE),
181 TC_PRIO_INTERACTIVE,
182 ECN_OR_COST(INTERACTIVE),
183 TC_PRIO_INTERACTIVE_BULK,
184 ECN_OR_COST(INTERACTIVE_BULK),
185 TC_PRIO_INTERACTIVE_BULK,
186 ECN_OR_COST(INTERACTIVE_BULK)
187};
188EXPORT_SYMBOL(ip_tos2prio);
189
190static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
191#define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
192
193#ifdef CONFIG_PROC_FS
194static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
195{
196 if (*pos)
197 return NULL;
198 return SEQ_START_TOKEN;
199}
200
201static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
202{
203 ++*pos;
204 return NULL;
205}
206
207static void rt_cache_seq_stop(struct seq_file *seq, void *v)
208{
209}
210
211static int rt_cache_seq_show(struct seq_file *seq, void *v)
212{
213 if (v == SEQ_START_TOKEN)
214 seq_printf(seq, "%-127s\n",
215 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
216 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
217 "HHUptod\tSpecDst");
218 return 0;
219}
220
221static const struct seq_operations rt_cache_seq_ops = {
222 .start = rt_cache_seq_start,
223 .next = rt_cache_seq_next,
224 .stop = rt_cache_seq_stop,
225 .show = rt_cache_seq_show,
226};
227
228static int rt_cache_seq_open(struct inode *inode, struct file *file)
229{
230 return seq_open(file, &rt_cache_seq_ops);
231}
232
233static const struct file_operations rt_cache_seq_fops = {
234 .owner = THIS_MODULE,
235 .open = rt_cache_seq_open,
236 .read = seq_read,
237 .llseek = seq_lseek,
238 .release = seq_release,
239};
240
241
242static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
243{
244 int cpu;
245
246 if (*pos == 0)
247 return SEQ_START_TOKEN;
248
249 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
250 if (!cpu_possible(cpu))
251 continue;
252 *pos = cpu+1;
253 return &per_cpu(rt_cache_stat, cpu);
254 }
255 return NULL;
256}
257
258static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
259{
260 int cpu;
261
262 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
263 if (!cpu_possible(cpu))
264 continue;
265 *pos = cpu+1;
266 return &per_cpu(rt_cache_stat, cpu);
267 }
268 return NULL;
269
270}
271
272static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
273{
274
275}
276
277static int rt_cpu_seq_show(struct seq_file *seq, void *v)
278{
279 struct rt_cache_stat *st = v;
280
281 if (v == SEQ_START_TOKEN) {
282 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
283 return 0;
284 }
285
286 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
287 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
288 dst_entries_get_slow(&ipv4_dst_ops),
289 0,
290 st->in_slow_tot,
291 st->in_slow_mc,
292 st->in_no_route,
293 st->in_brd,
294 st->in_martian_dst,
295 st->in_martian_src,
296
297 0,
298 st->out_slow_tot,
299 st->out_slow_mc,
300
301 0,
302 0,
303 0,
304 0,
305 0,
306 0
307 );
308 return 0;
309}
310
311static const struct seq_operations rt_cpu_seq_ops = {
312 .start = rt_cpu_seq_start,
313 .next = rt_cpu_seq_next,
314 .stop = rt_cpu_seq_stop,
315 .show = rt_cpu_seq_show,
316};
317
318
319static int rt_cpu_seq_open(struct inode *inode, struct file *file)
320{
321 return seq_open(file, &rt_cpu_seq_ops);
322}
323
324static const struct file_operations rt_cpu_seq_fops = {
325 .owner = THIS_MODULE,
326 .open = rt_cpu_seq_open,
327 .read = seq_read,
328 .llseek = seq_lseek,
329 .release = seq_release,
330};
331
332#ifdef CONFIG_IP_ROUTE_CLASSID
333static int rt_acct_proc_show(struct seq_file *m, void *v)
334{
335 struct ip_rt_acct *dst, *src;
336 unsigned int i, j;
337
338 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
339 if (!dst)
340 return -ENOMEM;
341
342 for_each_possible_cpu(i) {
343 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
344 for (j = 0; j < 256; j++) {
345 dst[j].o_bytes += src[j].o_bytes;
346 dst[j].o_packets += src[j].o_packets;
347 dst[j].i_bytes += src[j].i_bytes;
348 dst[j].i_packets += src[j].i_packets;
349 }
350 }
351
352 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
353 kfree(dst);
354 return 0;
355}
356
357static int rt_acct_proc_open(struct inode *inode, struct file *file)
358{
359 return single_open(file, rt_acct_proc_show, NULL);
360}
361
362static const struct file_operations rt_acct_proc_fops = {
363 .owner = THIS_MODULE,
364 .open = rt_acct_proc_open,
365 .read = seq_read,
366 .llseek = seq_lseek,
367 .release = single_release,
368};
369#endif
370
371static int __net_init ip_rt_do_proc_init(struct net *net)
372{
373 struct proc_dir_entry *pde;
374
375 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
376 &rt_cache_seq_fops);
377 if (!pde)
378 goto err1;
379
380 pde = proc_create("rt_cache", S_IRUGO,
381 net->proc_net_stat, &rt_cpu_seq_fops);
382 if (!pde)
383 goto err2;
384
385#ifdef CONFIG_IP_ROUTE_CLASSID
386 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
387 if (!pde)
388 goto err3;
389#endif
390 return 0;
391
392#ifdef CONFIG_IP_ROUTE_CLASSID
393err3:
394 remove_proc_entry("rt_cache", net->proc_net_stat);
395#endif
396err2:
397 remove_proc_entry("rt_cache", net->proc_net);
398err1:
399 return -ENOMEM;
400}
401
402static void __net_exit ip_rt_do_proc_exit(struct net *net)
403{
404 remove_proc_entry("rt_cache", net->proc_net_stat);
405 remove_proc_entry("rt_cache", net->proc_net);
406#ifdef CONFIG_IP_ROUTE_CLASSID
407 remove_proc_entry("rt_acct", net->proc_net);
408#endif
409}
410
411static struct pernet_operations ip_rt_proc_ops __net_initdata = {
412 .init = ip_rt_do_proc_init,
413 .exit = ip_rt_do_proc_exit,
414};
415
416static int __init ip_rt_proc_init(void)
417{
418 return register_pernet_subsys(&ip_rt_proc_ops);
419}
420
421#else
422static inline int ip_rt_proc_init(void)
423{
424 return 0;
425}
426#endif
427
428static inline bool rt_is_expired(const struct rtable *rth)
429{
430 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
431}
432
433void rt_cache_flush(struct net *net)
434{
435 rt_genid_bump_ipv4(net);
436}
437
438static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
439 struct sk_buff *skb,
440 const void *daddr)
441{
442 struct net_device *dev = dst->dev;
443 const __be32 *pkey = daddr;
444 const struct rtable *rt;
445 struct neighbour *n;
446
447 rt = (const struct rtable *) dst;
448 if (rt->rt_gateway)
449 pkey = (const __be32 *) &rt->rt_gateway;
450 else if (skb)
451 pkey = &ip_hdr(skb)->daddr;
452
453 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
454 if (n)
455 return n;
456 return neigh_create(&arp_tbl, pkey, dev);
457}
458
459#define IP_IDENTS_SZ 2048u
460struct ip_ident_bucket {
461 atomic_t id;
462 u32 stamp32;
463};
464
465static struct ip_ident_bucket *ip_idents __read_mostly;
466
467
468
469
470
471u32 ip_idents_reserve(u32 hash, int segs)
472{
473 struct ip_ident_bucket *bucket = ip_idents + hash % IP_IDENTS_SZ;
474 u32 old = ACCESS_ONCE(bucket->stamp32);
475 u32 now = (u32)jiffies;
476 u32 delta = 0;
477
478 if (old != now && cmpxchg(&bucket->stamp32, old, now) == old)
479 delta = prandom_u32_max(now - old);
480
481 return atomic_add_return(segs + delta, &bucket->id) - segs;
482}
483EXPORT_SYMBOL(ip_idents_reserve);
484
485void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
486{
487 static u32 ip_idents_hashrnd __read_mostly;
488 u32 hash, id;
489
490 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
491
492 hash = jhash_3words((__force u32)iph->daddr,
493 (__force u32)iph->saddr,
494 iph->protocol ^ net_hash_mix(net),
495 ip_idents_hashrnd);
496 id = ip_idents_reserve(hash, segs);
497 iph->id = htons(id);
498}
499EXPORT_SYMBOL(__ip_select_ident);
500
501static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
502 const struct iphdr *iph,
503 int oif, u8 tos,
504 u8 prot, u32 mark, int flow_flags)
505{
506 if (sk) {
507 const struct inet_sock *inet = inet_sk(sk);
508
509 oif = sk->sk_bound_dev_if;
510 mark = sk->sk_mark;
511 tos = RT_CONN_FLAGS(sk);
512 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
513 }
514 flowi4_init_output(fl4, oif, mark, tos,
515 RT_SCOPE_UNIVERSE, prot,
516 flow_flags,
517 iph->daddr, iph->saddr, 0, 0);
518}
519
520static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
521 const struct sock *sk)
522{
523 const struct iphdr *iph = ip_hdr(skb);
524 int oif = skb->dev->ifindex;
525 u8 tos = RT_TOS(iph->tos);
526 u8 prot = iph->protocol;
527 u32 mark = skb->mark;
528
529 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
530}
531
532static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
533{
534 const struct inet_sock *inet = inet_sk(sk);
535 const struct ip_options_rcu *inet_opt;
536 __be32 daddr = inet->inet_daddr;
537
538 rcu_read_lock();
539 inet_opt = rcu_dereference(inet->inet_opt);
540 if (inet_opt && inet_opt->opt.srr)
541 daddr = inet_opt->opt.faddr;
542 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
543 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
544 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
545 inet_sk_flowi_flags(sk),
546 daddr, inet->inet_saddr, 0, 0);
547 rcu_read_unlock();
548}
549
550static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
551 const struct sk_buff *skb)
552{
553 if (skb)
554 build_skb_flow_key(fl4, skb, sk);
555 else
556 build_sk_flow_key(fl4, sk);
557}
558
559static inline void rt_free(struct rtable *rt)
560{
561 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
562}
563
564static DEFINE_SPINLOCK(fnhe_lock);
565
566static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
567{
568 struct rtable *rt;
569
570 rt = rcu_dereference(fnhe->fnhe_rth_input);
571 if (rt) {
572 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
573 rt_free(rt);
574 }
575 rt = rcu_dereference(fnhe->fnhe_rth_output);
576 if (rt) {
577 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
578 rt_free(rt);
579 }
580}
581
582static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
583{
584 struct fib_nh_exception *fnhe, *oldest;
585
586 oldest = rcu_dereference(hash->chain);
587 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
588 fnhe = rcu_dereference(fnhe->fnhe_next)) {
589 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
590 oldest = fnhe;
591 }
592 fnhe_flush_routes(oldest);
593 return oldest;
594}
595
596static inline u32 fnhe_hashfun(__be32 daddr)
597{
598 static u32 fnhe_hashrnd __read_mostly;
599 u32 hval;
600
601 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
602 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
603 return hash_32(hval, FNHE_HASH_SHIFT);
604}
605
606static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
607{
608 rt->rt_pmtu = fnhe->fnhe_pmtu;
609 rt->dst.expires = fnhe->fnhe_expires;
610
611 if (fnhe->fnhe_gw) {
612 rt->rt_flags |= RTCF_REDIRECTED;
613 rt->rt_gateway = fnhe->fnhe_gw;
614 rt->rt_uses_gateway = 1;
615 }
616}
617
618static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
619 u32 pmtu, unsigned long expires)
620{
621 struct fnhe_hash_bucket *hash;
622 struct fib_nh_exception *fnhe;
623 struct rtable *rt;
624 unsigned int i;
625 int depth;
626 u32 hval = fnhe_hashfun(daddr);
627
628 spin_lock_bh(&fnhe_lock);
629
630 hash = rcu_dereference(nh->nh_exceptions);
631 if (!hash) {
632 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
633 if (!hash)
634 goto out_unlock;
635 rcu_assign_pointer(nh->nh_exceptions, hash);
636 }
637
638 hash += hval;
639
640 depth = 0;
641 for (fnhe = rcu_dereference(hash->chain); fnhe;
642 fnhe = rcu_dereference(fnhe->fnhe_next)) {
643 if (fnhe->fnhe_daddr == daddr)
644 break;
645 depth++;
646 }
647
648 if (fnhe) {
649 if (gw)
650 fnhe->fnhe_gw = gw;
651 if (pmtu) {
652 fnhe->fnhe_pmtu = pmtu;
653 fnhe->fnhe_expires = max(1UL, expires);
654 }
655
656 rt = rcu_dereference(fnhe->fnhe_rth_input);
657 if (rt)
658 fill_route_from_fnhe(rt, fnhe);
659 rt = rcu_dereference(fnhe->fnhe_rth_output);
660 if (rt)
661 fill_route_from_fnhe(rt, fnhe);
662 } else {
663 if (depth > FNHE_RECLAIM_DEPTH)
664 fnhe = fnhe_oldest(hash);
665 else {
666 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
667 if (!fnhe)
668 goto out_unlock;
669
670 fnhe->fnhe_next = hash->chain;
671 rcu_assign_pointer(hash->chain, fnhe);
672 }
673 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
674 fnhe->fnhe_daddr = daddr;
675 fnhe->fnhe_gw = gw;
676 fnhe->fnhe_pmtu = pmtu;
677 fnhe->fnhe_expires = expires;
678
679
680
681
682
683 rt = rcu_dereference(nh->nh_rth_input);
684 if (rt)
685 rt->dst.obsolete = DST_OBSOLETE_KILL;
686
687 for_each_possible_cpu(i) {
688 struct rtable __rcu **prt;
689 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
690 rt = rcu_dereference(*prt);
691 if (rt)
692 rt->dst.obsolete = DST_OBSOLETE_KILL;
693 }
694 }
695
696 fnhe->fnhe_stamp = jiffies;
697
698out_unlock:
699 spin_unlock_bh(&fnhe_lock);
700}
701
702static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
703 bool kill_route)
704{
705 __be32 new_gw = icmp_hdr(skb)->un.gateway;
706 __be32 old_gw = ip_hdr(skb)->saddr;
707 struct net_device *dev = skb->dev;
708 struct in_device *in_dev;
709 struct fib_result res;
710 struct neighbour *n;
711 struct net *net;
712
713 switch (icmp_hdr(skb)->code & 7) {
714 case ICMP_REDIR_NET:
715 case ICMP_REDIR_NETTOS:
716 case ICMP_REDIR_HOST:
717 case ICMP_REDIR_HOSTTOS:
718 break;
719
720 default:
721 return;
722 }
723
724 if (rt->rt_gateway != old_gw)
725 return;
726
727 in_dev = __in_dev_get_rcu(dev);
728 if (!in_dev)
729 return;
730
731 net = dev_net(dev);
732 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
733 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
734 ipv4_is_zeronet(new_gw))
735 goto reject_redirect;
736
737 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
738 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
739 goto reject_redirect;
740 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
741 goto reject_redirect;
742 } else {
743 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
744 goto reject_redirect;
745 }
746
747 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
748 if (!IS_ERR(n)) {
749 if (!(n->nud_state & NUD_VALID)) {
750 neigh_event_send(n, NULL);
751 } else {
752 if (fib_lookup(net, fl4, &res) == 0) {
753 struct fib_nh *nh = &FIB_RES_NH(res);
754
755 update_or_create_fnhe(nh, fl4->daddr, new_gw,
756 0, 0);
757 }
758 if (kill_route)
759 rt->dst.obsolete = DST_OBSOLETE_KILL;
760 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
761 }
762 neigh_release(n);
763 }
764 return;
765
766reject_redirect:
767#ifdef CONFIG_IP_ROUTE_VERBOSE
768 if (IN_DEV_LOG_MARTIANS(in_dev)) {
769 const struct iphdr *iph = (const struct iphdr *) skb->data;
770 __be32 daddr = iph->daddr;
771 __be32 saddr = iph->saddr;
772
773 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
774 " Advised path = %pI4 -> %pI4\n",
775 &old_gw, dev->name, &new_gw,
776 &saddr, &daddr);
777 }
778#endif
779 ;
780}
781
782static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
783{
784 struct rtable *rt;
785 struct flowi4 fl4;
786 const struct iphdr *iph = (const struct iphdr *) skb->data;
787 int oif = skb->dev->ifindex;
788 u8 tos = RT_TOS(iph->tos);
789 u8 prot = iph->protocol;
790 u32 mark = skb->mark;
791
792 rt = (struct rtable *) dst;
793
794 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
795 __ip_do_redirect(rt, skb, &fl4, true);
796}
797
798static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
799{
800 struct rtable *rt = (struct rtable *)dst;
801 struct dst_entry *ret = dst;
802
803 if (rt) {
804 if (dst->obsolete > 0) {
805 ip_rt_put(rt);
806 ret = NULL;
807 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
808 rt->dst.expires) {
809 ip_rt_put(rt);
810 ret = NULL;
811 }
812 }
813 return ret;
814}
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832void ip_rt_send_redirect(struct sk_buff *skb)
833{
834 struct rtable *rt = skb_rtable(skb);
835 struct in_device *in_dev;
836 struct inet_peer *peer;
837 struct net *net;
838 int log_martians;
839
840 rcu_read_lock();
841 in_dev = __in_dev_get_rcu(rt->dst.dev);
842 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
843 rcu_read_unlock();
844 return;
845 }
846 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
847 rcu_read_unlock();
848
849 net = dev_net(rt->dst.dev);
850 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
851 if (!peer) {
852 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
853 rt_nexthop(rt, ip_hdr(skb)->daddr));
854 return;
855 }
856
857
858
859
860 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
861 peer->rate_tokens = 0;
862
863
864
865
866 if (peer->rate_tokens >= ip_rt_redirect_number) {
867 peer->rate_last = jiffies;
868 goto out_put_peer;
869 }
870
871
872
873
874 if (peer->rate_tokens == 0 ||
875 time_after(jiffies,
876 (peer->rate_last +
877 (ip_rt_redirect_load << peer->rate_tokens)))) {
878 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
879
880 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
881 peer->rate_last = jiffies;
882 ++peer->rate_tokens;
883#ifdef CONFIG_IP_ROUTE_VERBOSE
884 if (log_martians &&
885 peer->rate_tokens == ip_rt_redirect_number)
886 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
887 &ip_hdr(skb)->saddr, inet_iif(skb),
888 &ip_hdr(skb)->daddr, &gw);
889#endif
890 }
891out_put_peer:
892 inet_putpeer(peer);
893}
894
895static int ip_error(struct sk_buff *skb)
896{
897 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
898 struct rtable *rt = skb_rtable(skb);
899 struct inet_peer *peer;
900 unsigned long now;
901 struct net *net;
902 bool send;
903 int code;
904
905
906 if (!in_dev)
907 goto out;
908
909 net = dev_net(rt->dst.dev);
910 if (!IN_DEV_FORWARD(in_dev)) {
911 switch (rt->dst.error) {
912 case EHOSTUNREACH:
913 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
914 break;
915
916 case ENETUNREACH:
917 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
918 break;
919 }
920 goto out;
921 }
922
923 switch (rt->dst.error) {
924 case EINVAL:
925 default:
926 goto out;
927 case EHOSTUNREACH:
928 code = ICMP_HOST_UNREACH;
929 break;
930 case ENETUNREACH:
931 code = ICMP_NET_UNREACH;
932 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
933 break;
934 case EACCES:
935 code = ICMP_PKT_FILTERED;
936 break;
937 }
938
939 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
940
941 send = true;
942 if (peer) {
943 now = jiffies;
944 peer->rate_tokens += now - peer->rate_last;
945 if (peer->rate_tokens > ip_rt_error_burst)
946 peer->rate_tokens = ip_rt_error_burst;
947 peer->rate_last = now;
948 if (peer->rate_tokens >= ip_rt_error_cost)
949 peer->rate_tokens -= ip_rt_error_cost;
950 else
951 send = false;
952 inet_putpeer(peer);
953 }
954 if (send)
955 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
956
957out: kfree_skb(skb);
958 return 0;
959}
960
961static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
962{
963 struct dst_entry *dst = &rt->dst;
964 struct fib_result res;
965
966 if (dst_metric_locked(dst, RTAX_MTU))
967 return;
968
969 if (ipv4_mtu(dst) < mtu)
970 return;
971
972 if (mtu < ip_rt_min_pmtu)
973 mtu = ip_rt_min_pmtu;
974
975 if (rt->rt_pmtu == mtu &&
976 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
977 return;
978
979 rcu_read_lock();
980 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
981 struct fib_nh *nh = &FIB_RES_NH(res);
982
983 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
984 jiffies + ip_rt_mtu_expires);
985 }
986 rcu_read_unlock();
987}
988
989static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
990 struct sk_buff *skb, u32 mtu)
991{
992 struct rtable *rt = (struct rtable *) dst;
993 struct flowi4 fl4;
994
995 ip_rt_build_flow_key(&fl4, sk, skb);
996 __ip_rt_update_pmtu(rt, &fl4, mtu);
997}
998
999void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1000 int oif, u32 mark, u8 protocol, int flow_flags)
1001{
1002 const struct iphdr *iph = (const struct iphdr *) skb->data;
1003 struct flowi4 fl4;
1004 struct rtable *rt;
1005
1006 if (!mark)
1007 mark = IP4_REPLY_MARK(net, skb->mark);
1008
1009 __build_flow_key(&fl4, NULL, iph, oif,
1010 RT_TOS(iph->tos), protocol, mark, flow_flags);
1011 rt = __ip_route_output_key(net, &fl4);
1012 if (!IS_ERR(rt)) {
1013 __ip_rt_update_pmtu(rt, &fl4, mtu);
1014 ip_rt_put(rt);
1015 }
1016}
1017EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1018
1019static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1020{
1021 const struct iphdr *iph = (const struct iphdr *) skb->data;
1022 struct flowi4 fl4;
1023 struct rtable *rt;
1024
1025 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1026
1027 if (!fl4.flowi4_mark)
1028 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1029
1030 rt = __ip_route_output_key(sock_net(sk), &fl4);
1031 if (!IS_ERR(rt)) {
1032 __ip_rt_update_pmtu(rt, &fl4, mtu);
1033 ip_rt_put(rt);
1034 }
1035}
1036
1037void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1038{
1039 const struct iphdr *iph = (const struct iphdr *) skb->data;
1040 struct flowi4 fl4;
1041 struct rtable *rt;
1042 struct dst_entry *odst = NULL;
1043 bool new = false;
1044
1045 bh_lock_sock(sk);
1046
1047 if (!ip_sk_accept_pmtu(sk))
1048 goto out;
1049
1050 odst = sk_dst_get(sk);
1051
1052 if (sock_owned_by_user(sk) || !odst) {
1053 __ipv4_sk_update_pmtu(skb, sk, mtu);
1054 goto out;
1055 }
1056
1057 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1058
1059 rt = (struct rtable *)odst;
1060 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1061 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1062 if (IS_ERR(rt))
1063 goto out;
1064
1065 new = true;
1066 }
1067
1068 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1069
1070 if (!dst_check(&rt->dst, 0)) {
1071 if (new)
1072 dst_release(&rt->dst);
1073
1074 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1075 if (IS_ERR(rt))
1076 goto out;
1077
1078 new = true;
1079 }
1080
1081 if (new)
1082 sk_dst_set(sk, &rt->dst);
1083
1084out:
1085 bh_unlock_sock(sk);
1086 dst_release(odst);
1087}
1088EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1089
1090void ipv4_redirect(struct sk_buff *skb, struct net *net,
1091 int oif, u32 mark, u8 protocol, int flow_flags)
1092{
1093 const struct iphdr *iph = (const struct iphdr *) skb->data;
1094 struct flowi4 fl4;
1095 struct rtable *rt;
1096
1097 __build_flow_key(&fl4, NULL, iph, oif,
1098 RT_TOS(iph->tos), protocol, mark, flow_flags);
1099 rt = __ip_route_output_key(net, &fl4);
1100 if (!IS_ERR(rt)) {
1101 __ip_do_redirect(rt, skb, &fl4, false);
1102 ip_rt_put(rt);
1103 }
1104}
1105EXPORT_SYMBOL_GPL(ipv4_redirect);
1106
1107void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1108{
1109 const struct iphdr *iph = (const struct iphdr *) skb->data;
1110 struct flowi4 fl4;
1111 struct rtable *rt;
1112
1113 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1114 rt = __ip_route_output_key(sock_net(sk), &fl4);
1115 if (!IS_ERR(rt)) {
1116 __ip_do_redirect(rt, skb, &fl4, false);
1117 ip_rt_put(rt);
1118 }
1119}
1120EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1121
1122static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1123{
1124 struct rtable *rt = (struct rtable *) dst;
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1135 return NULL;
1136 return dst;
1137}
1138
1139static void ipv4_link_failure(struct sk_buff *skb)
1140{
1141 struct rtable *rt;
1142
1143 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1144
1145 rt = skb_rtable(skb);
1146 if (rt)
1147 dst_set_expires(&rt->dst, 0);
1148}
1149
1150static int ip_rt_bug(struct sock *sk, struct sk_buff *skb)
1151{
1152 pr_debug("%s: %pI4 -> %pI4, %s\n",
1153 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1154 skb->dev ? skb->dev->name : "?");
1155 kfree_skb(skb);
1156 WARN_ON(1);
1157 return 0;
1158}
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1170{
1171 __be32 src;
1172
1173 if (rt_is_output_route(rt))
1174 src = ip_hdr(skb)->saddr;
1175 else {
1176 struct fib_result res;
1177 struct flowi4 fl4;
1178 struct iphdr *iph;
1179
1180 iph = ip_hdr(skb);
1181
1182 memset(&fl4, 0, sizeof(fl4));
1183 fl4.daddr = iph->daddr;
1184 fl4.saddr = iph->saddr;
1185 fl4.flowi4_tos = RT_TOS(iph->tos);
1186 fl4.flowi4_oif = rt->dst.dev->ifindex;
1187 fl4.flowi4_iif = skb->dev->ifindex;
1188 fl4.flowi4_mark = skb->mark;
1189
1190 rcu_read_lock();
1191 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1192 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1193 else
1194 src = inet_select_addr(rt->dst.dev,
1195 rt_nexthop(rt, iph->daddr),
1196 RT_SCOPE_UNIVERSE);
1197 rcu_read_unlock();
1198 }
1199 memcpy(addr, &src, 4);
1200}
1201
1202#ifdef CONFIG_IP_ROUTE_CLASSID
1203static void set_class_tag(struct rtable *rt, u32 tag)
1204{
1205 if (!(rt->dst.tclassid & 0xFFFF))
1206 rt->dst.tclassid |= tag & 0xFFFF;
1207 if (!(rt->dst.tclassid & 0xFFFF0000))
1208 rt->dst.tclassid |= tag & 0xFFFF0000;
1209}
1210#endif
1211
1212static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1213{
1214 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1215
1216 if (advmss == 0) {
1217 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1218 ip_rt_min_advmss);
1219 if (advmss > 65535 - 40)
1220 advmss = 65535 - 40;
1221 }
1222 return advmss;
1223}
1224
1225static unsigned int ipv4_mtu(const struct dst_entry *dst)
1226{
1227 const struct rtable *rt = (const struct rtable *) dst;
1228 unsigned int mtu = rt->rt_pmtu;
1229
1230 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1231 mtu = dst_metric_raw(dst, RTAX_MTU);
1232
1233 if (mtu)
1234 return mtu;
1235
1236 mtu = dst->dev->mtu;
1237
1238 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1239 if (rt->rt_uses_gateway && mtu > 576)
1240 mtu = 576;
1241 }
1242
1243 return min_t(unsigned int, mtu, IP_MAX_MTU);
1244}
1245
1246static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1247{
1248 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1249 struct fib_nh_exception *fnhe;
1250 u32 hval;
1251
1252 if (!hash)
1253 return NULL;
1254
1255 hval = fnhe_hashfun(daddr);
1256
1257 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1258 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1259 if (fnhe->fnhe_daddr == daddr)
1260 return fnhe;
1261 }
1262 return NULL;
1263}
1264
1265static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1266 __be32 daddr)
1267{
1268 bool ret = false;
1269
1270 spin_lock_bh(&fnhe_lock);
1271
1272 if (daddr == fnhe->fnhe_daddr) {
1273 struct rtable __rcu **porig;
1274 struct rtable *orig;
1275 int genid = fnhe_genid(dev_net(rt->dst.dev));
1276
1277 if (rt_is_input_route(rt))
1278 porig = &fnhe->fnhe_rth_input;
1279 else
1280 porig = &fnhe->fnhe_rth_output;
1281 orig = rcu_dereference(*porig);
1282
1283 if (fnhe->fnhe_genid != genid) {
1284 fnhe->fnhe_genid = genid;
1285 fnhe->fnhe_gw = 0;
1286 fnhe->fnhe_pmtu = 0;
1287 fnhe->fnhe_expires = 0;
1288 fnhe_flush_routes(fnhe);
1289 orig = NULL;
1290 }
1291 fill_route_from_fnhe(rt, fnhe);
1292 if (!rt->rt_gateway)
1293 rt->rt_gateway = daddr;
1294
1295 if (!(rt->dst.flags & DST_NOCACHE)) {
1296 rcu_assign_pointer(*porig, rt);
1297 if (orig)
1298 rt_free(orig);
1299 ret = true;
1300 }
1301
1302 fnhe->fnhe_stamp = jiffies;
1303 }
1304 spin_unlock_bh(&fnhe_lock);
1305
1306 return ret;
1307}
1308
1309static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1310{
1311 struct rtable *orig, *prev, **p;
1312 bool ret = true;
1313
1314 if (rt_is_input_route(rt)) {
1315 p = (struct rtable **)&nh->nh_rth_input;
1316 } else {
1317 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1318 }
1319 orig = *p;
1320
1321 prev = cmpxchg(p, orig, rt);
1322 if (prev == orig) {
1323 if (orig)
1324 rt_free(orig);
1325 } else
1326 ret = false;
1327
1328 return ret;
1329}
1330
1331struct uncached_list {
1332 spinlock_t lock;
1333 struct list_head head;
1334};
1335
1336static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1337
1338static void rt_add_uncached_list(struct rtable *rt)
1339{
1340 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1341
1342 rt->rt_uncached_list = ul;
1343
1344 spin_lock_bh(&ul->lock);
1345 list_add_tail(&rt->rt_uncached, &ul->head);
1346 spin_unlock_bh(&ul->lock);
1347}
1348
1349static void ipv4_dst_destroy(struct dst_entry *dst)
1350{
1351 struct rtable *rt = (struct rtable *) dst;
1352
1353 if (!list_empty(&rt->rt_uncached)) {
1354 struct uncached_list *ul = rt->rt_uncached_list;
1355
1356 spin_lock_bh(&ul->lock);
1357 list_del(&rt->rt_uncached);
1358 spin_unlock_bh(&ul->lock);
1359 }
1360}
1361
1362void rt_flush_dev(struct net_device *dev)
1363{
1364 struct net *net = dev_net(dev);
1365 struct rtable *rt;
1366 int cpu;
1367
1368 for_each_possible_cpu(cpu) {
1369 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1370
1371 spin_lock_bh(&ul->lock);
1372 list_for_each_entry(rt, &ul->head, rt_uncached) {
1373 if (rt->dst.dev != dev)
1374 continue;
1375 rt->dst.dev = net->loopback_dev;
1376 dev_hold(rt->dst.dev);
1377 dev_put(dev);
1378 }
1379 spin_unlock_bh(&ul->lock);
1380 }
1381}
1382
1383static bool rt_cache_valid(const struct rtable *rt)
1384{
1385 return rt &&
1386 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1387 !rt_is_expired(rt);
1388}
1389
1390static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1391 const struct fib_result *res,
1392 struct fib_nh_exception *fnhe,
1393 struct fib_info *fi, u16 type, u32 itag)
1394{
1395 bool cached = false;
1396
1397 if (fi) {
1398 struct fib_nh *nh = &FIB_RES_NH(*res);
1399
1400 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1401 rt->rt_gateway = nh->nh_gw;
1402 rt->rt_uses_gateway = 1;
1403 }
1404 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1405#ifdef CONFIG_IP_ROUTE_CLASSID
1406 rt->dst.tclassid = nh->nh_tclassid;
1407#endif
1408 if (unlikely(fnhe))
1409 cached = rt_bind_exception(rt, fnhe, daddr);
1410 else if (!(rt->dst.flags & DST_NOCACHE))
1411 cached = rt_cache_route(nh, rt);
1412 if (unlikely(!cached)) {
1413
1414
1415
1416
1417
1418 rt->dst.flags |= DST_NOCACHE;
1419 if (!rt->rt_gateway)
1420 rt->rt_gateway = daddr;
1421 rt_add_uncached_list(rt);
1422 }
1423 } else
1424 rt_add_uncached_list(rt);
1425
1426#ifdef CONFIG_IP_ROUTE_CLASSID
1427#ifdef CONFIG_IP_MULTIPLE_TABLES
1428 set_class_tag(rt, res->tclassid);
1429#endif
1430 set_class_tag(rt, itag);
1431#endif
1432}
1433
1434static struct rtable *rt_dst_alloc(struct net_device *dev,
1435 bool nopolicy, bool noxfrm, bool will_cache)
1436{
1437 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1438 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1439 (nopolicy ? DST_NOPOLICY : 0) |
1440 (noxfrm ? DST_NOXFRM : 0));
1441}
1442
1443
1444static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1445 u8 tos, struct net_device *dev, int our)
1446{
1447 struct rtable *rth;
1448 struct in_device *in_dev = __in_dev_get_rcu(dev);
1449 u32 itag = 0;
1450 int err;
1451
1452
1453
1454 if (!in_dev)
1455 return -EINVAL;
1456
1457 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1458 skb->protocol != htons(ETH_P_IP))
1459 goto e_inval;
1460
1461 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1462 if (ipv4_is_loopback(saddr))
1463 goto e_inval;
1464
1465 if (ipv4_is_zeronet(saddr)) {
1466 if (!ipv4_is_local_multicast(daddr))
1467 goto e_inval;
1468 } else {
1469 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1470 in_dev, &itag);
1471 if (err < 0)
1472 goto e_err;
1473 }
1474 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1475 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1476 if (!rth)
1477 goto e_nobufs;
1478
1479#ifdef CONFIG_IP_ROUTE_CLASSID
1480 rth->dst.tclassid = itag;
1481#endif
1482 rth->dst.output = ip_rt_bug;
1483
1484 rth->rt_genid = rt_genid_ipv4(dev_net(dev));
1485 rth->rt_flags = RTCF_MULTICAST;
1486 rth->rt_type = RTN_MULTICAST;
1487 rth->rt_is_input= 1;
1488 rth->rt_iif = 0;
1489 rth->rt_pmtu = 0;
1490 rth->rt_gateway = 0;
1491 rth->rt_uses_gateway = 0;
1492 INIT_LIST_HEAD(&rth->rt_uncached);
1493 if (our) {
1494 rth->dst.input= ip_local_deliver;
1495 rth->rt_flags |= RTCF_LOCAL;
1496 }
1497
1498#ifdef CONFIG_IP_MROUTE
1499 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1500 rth->dst.input = ip_mr_input;
1501#endif
1502 RT_CACHE_STAT_INC(in_slow_mc);
1503
1504 skb_dst_set(skb, &rth->dst);
1505 return 0;
1506
1507e_nobufs:
1508 return -ENOBUFS;
1509e_inval:
1510 return -EINVAL;
1511e_err:
1512 return err;
1513}
1514
1515
1516static void ip_handle_martian_source(struct net_device *dev,
1517 struct in_device *in_dev,
1518 struct sk_buff *skb,
1519 __be32 daddr,
1520 __be32 saddr)
1521{
1522 RT_CACHE_STAT_INC(in_martian_src);
1523#ifdef CONFIG_IP_ROUTE_VERBOSE
1524 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1525
1526
1527
1528
1529 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1530 &daddr, &saddr, dev->name);
1531 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1532 print_hex_dump(KERN_WARNING, "ll header: ",
1533 DUMP_PREFIX_OFFSET, 16, 1,
1534 skb_mac_header(skb),
1535 dev->hard_header_len, true);
1536 }
1537 }
1538#endif
1539}
1540
1541
1542static int __mkroute_input(struct sk_buff *skb,
1543 const struct fib_result *res,
1544 struct in_device *in_dev,
1545 __be32 daddr, __be32 saddr, u32 tos)
1546{
1547 struct fib_nh_exception *fnhe;
1548 struct rtable *rth;
1549 int err;
1550 struct in_device *out_dev;
1551 unsigned int flags = 0;
1552 bool do_cache;
1553 u32 itag = 0;
1554
1555
1556 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1557 if (!out_dev) {
1558 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1559 return -EINVAL;
1560 }
1561
1562 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1563 in_dev->dev, in_dev, &itag);
1564 if (err < 0) {
1565 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1566 saddr);
1567
1568 goto cleanup;
1569 }
1570
1571 do_cache = res->fi && !itag;
1572 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1573 skb->protocol == htons(ETH_P_IP) &&
1574 (IN_DEV_SHARED_MEDIA(out_dev) ||
1575 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1576 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1577
1578 if (skb->protocol != htons(ETH_P_IP)) {
1579
1580
1581
1582
1583
1584
1585
1586 if (out_dev == in_dev &&
1587 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1588 err = -EINVAL;
1589 goto cleanup;
1590 }
1591 }
1592
1593 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1594 if (do_cache) {
1595 if (fnhe)
1596 rth = rcu_dereference(fnhe->fnhe_rth_input);
1597 else
1598 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1599
1600 if (rt_cache_valid(rth)) {
1601 skb_dst_set_noref(skb, &rth->dst);
1602 goto out;
1603 }
1604 }
1605
1606 rth = rt_dst_alloc(out_dev->dev,
1607 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1608 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1609 if (!rth) {
1610 err = -ENOBUFS;
1611 goto cleanup;
1612 }
1613
1614 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev));
1615 rth->rt_flags = flags;
1616 rth->rt_type = res->type;
1617 rth->rt_is_input = 1;
1618 rth->rt_iif = 0;
1619 rth->rt_pmtu = 0;
1620 rth->rt_gateway = 0;
1621 rth->rt_uses_gateway = 0;
1622 INIT_LIST_HEAD(&rth->rt_uncached);
1623 RT_CACHE_STAT_INC(in_slow_tot);
1624
1625 rth->dst.input = ip_forward;
1626 rth->dst.output = ip_output;
1627
1628 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1629 skb_dst_set(skb, &rth->dst);
1630out:
1631 err = 0;
1632 cleanup:
1633 return err;
1634}
1635
1636static int ip_mkroute_input(struct sk_buff *skb,
1637 struct fib_result *res,
1638 const struct flowi4 *fl4,
1639 struct in_device *in_dev,
1640 __be32 daddr, __be32 saddr, u32 tos)
1641{
1642#ifdef CONFIG_IP_ROUTE_MULTIPATH
1643 if (res->fi && res->fi->fib_nhs > 1)
1644 fib_select_multipath(res);
1645#endif
1646
1647
1648 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1649}
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1663 u8 tos, struct net_device *dev)
1664{
1665 struct fib_result res;
1666 struct in_device *in_dev = __in_dev_get_rcu(dev);
1667 struct flowi4 fl4;
1668 unsigned int flags = 0;
1669 u32 itag = 0;
1670 struct rtable *rth;
1671 int err = -EINVAL;
1672 struct net *net = dev_net(dev);
1673 bool do_cache;
1674
1675
1676
1677 if (!in_dev)
1678 goto out;
1679
1680
1681
1682
1683
1684 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1685 goto martian_source;
1686
1687 res.fi = NULL;
1688 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1689 goto brd_input;
1690
1691
1692
1693
1694 if (ipv4_is_zeronet(saddr))
1695 goto martian_source;
1696
1697 if (ipv4_is_zeronet(daddr))
1698 goto martian_destination;
1699
1700
1701
1702
1703 if (ipv4_is_loopback(daddr)) {
1704 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1705 goto martian_destination;
1706 } else if (ipv4_is_loopback(saddr)) {
1707 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1708 goto martian_source;
1709 }
1710
1711
1712
1713
1714 fl4.flowi4_oif = 0;
1715 fl4.flowi4_iif = dev->ifindex;
1716 fl4.flowi4_mark = skb->mark;
1717 fl4.flowi4_tos = tos;
1718 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1719 fl4.daddr = daddr;
1720 fl4.saddr = saddr;
1721 err = fib_lookup(net, &fl4, &res);
1722 if (err != 0) {
1723 if (!IN_DEV_FORWARD(in_dev))
1724 err = -EHOSTUNREACH;
1725 goto no_route;
1726 }
1727
1728 if (res.type == RTN_BROADCAST)
1729 goto brd_input;
1730
1731 if (res.type == RTN_LOCAL) {
1732 err = fib_validate_source(skb, saddr, daddr, tos,
1733 0, dev, in_dev, &itag);
1734 if (err < 0)
1735 goto martian_source_keep_err;
1736 goto local_input;
1737 }
1738
1739 if (!IN_DEV_FORWARD(in_dev)) {
1740 err = -EHOSTUNREACH;
1741 goto no_route;
1742 }
1743 if (res.type != RTN_UNICAST)
1744 goto martian_destination;
1745
1746 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1747out: return err;
1748
1749brd_input:
1750 if (skb->protocol != htons(ETH_P_IP))
1751 goto e_inval;
1752
1753 if (!ipv4_is_zeronet(saddr)) {
1754 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1755 in_dev, &itag);
1756 if (err < 0)
1757 goto martian_source_keep_err;
1758 }
1759 flags |= RTCF_BROADCAST;
1760 res.type = RTN_BROADCAST;
1761 RT_CACHE_STAT_INC(in_brd);
1762
1763local_input:
1764 do_cache = false;
1765 if (res.fi) {
1766 if (!itag) {
1767 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1768 if (rt_cache_valid(rth)) {
1769 skb_dst_set_noref(skb, &rth->dst);
1770 err = 0;
1771 goto out;
1772 }
1773 do_cache = true;
1774 }
1775 }
1776
1777 rth = rt_dst_alloc(net->loopback_dev,
1778 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1779 if (!rth)
1780 goto e_nobufs;
1781
1782 rth->dst.input= ip_local_deliver;
1783 rth->dst.output= ip_rt_bug;
1784#ifdef CONFIG_IP_ROUTE_CLASSID
1785 rth->dst.tclassid = itag;
1786#endif
1787
1788 rth->rt_genid = rt_genid_ipv4(net);
1789 rth->rt_flags = flags|RTCF_LOCAL;
1790 rth->rt_type = res.type;
1791 rth->rt_is_input = 1;
1792 rth->rt_iif = 0;
1793 rth->rt_pmtu = 0;
1794 rth->rt_gateway = 0;
1795 rth->rt_uses_gateway = 0;
1796 INIT_LIST_HEAD(&rth->rt_uncached);
1797 RT_CACHE_STAT_INC(in_slow_tot);
1798 if (res.type == RTN_UNREACHABLE) {
1799 rth->dst.input= ip_error;
1800 rth->dst.error= -err;
1801 rth->rt_flags &= ~RTCF_LOCAL;
1802 }
1803 if (do_cache) {
1804 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1805 rth->dst.flags |= DST_NOCACHE;
1806 rt_add_uncached_list(rth);
1807 }
1808 }
1809 skb_dst_set(skb, &rth->dst);
1810 err = 0;
1811 goto out;
1812
1813no_route:
1814 RT_CACHE_STAT_INC(in_no_route);
1815 res.type = RTN_UNREACHABLE;
1816 res.fi = NULL;
1817 goto local_input;
1818
1819
1820
1821
1822martian_destination:
1823 RT_CACHE_STAT_INC(in_martian_dst);
1824#ifdef CONFIG_IP_ROUTE_VERBOSE
1825 if (IN_DEV_LOG_MARTIANS(in_dev))
1826 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1827 &daddr, &saddr, dev->name);
1828#endif
1829
1830e_inval:
1831 err = -EINVAL;
1832 goto out;
1833
1834e_nobufs:
1835 err = -ENOBUFS;
1836 goto out;
1837
1838martian_source:
1839 err = -EINVAL;
1840martian_source_keep_err:
1841 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1842 goto out;
1843}
1844
1845int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1846 u8 tos, struct net_device *dev)
1847{
1848 int res;
1849
1850 rcu_read_lock();
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863 if (ipv4_is_multicast(daddr)) {
1864 struct in_device *in_dev = __in_dev_get_rcu(dev);
1865
1866 if (in_dev) {
1867 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1868 ip_hdr(skb)->protocol);
1869 if (our
1870#ifdef CONFIG_IP_MROUTE
1871 ||
1872 (!ipv4_is_local_multicast(daddr) &&
1873 IN_DEV_MFORWARD(in_dev))
1874#endif
1875 ) {
1876 int res = ip_route_input_mc(skb, daddr, saddr,
1877 tos, dev, our);
1878 rcu_read_unlock();
1879 return res;
1880 }
1881 }
1882 rcu_read_unlock();
1883 return -EINVAL;
1884 }
1885 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1886 rcu_read_unlock();
1887 return res;
1888}
1889EXPORT_SYMBOL(ip_route_input_noref);
1890
1891
1892static struct rtable *__mkroute_output(const struct fib_result *res,
1893 const struct flowi4 *fl4, int orig_oif,
1894 struct net_device *dev_out,
1895 unsigned int flags)
1896{
1897 struct fib_info *fi = res->fi;
1898 struct fib_nh_exception *fnhe;
1899 struct in_device *in_dev;
1900 u16 type = res->type;
1901 struct rtable *rth;
1902 bool do_cache;
1903
1904 in_dev = __in_dev_get_rcu(dev_out);
1905 if (!in_dev)
1906 return ERR_PTR(-EINVAL);
1907
1908 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1909 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1910 return ERR_PTR(-EINVAL);
1911
1912 if (ipv4_is_lbcast(fl4->daddr))
1913 type = RTN_BROADCAST;
1914 else if (ipv4_is_multicast(fl4->daddr))
1915 type = RTN_MULTICAST;
1916 else if (ipv4_is_zeronet(fl4->daddr))
1917 return ERR_PTR(-EINVAL);
1918
1919 if (dev_out->flags & IFF_LOOPBACK)
1920 flags |= RTCF_LOCAL;
1921
1922 do_cache = true;
1923 if (type == RTN_BROADCAST) {
1924 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1925 fi = NULL;
1926 } else if (type == RTN_MULTICAST) {
1927 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1928 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1929 fl4->flowi4_proto))
1930 flags &= ~RTCF_LOCAL;
1931 else
1932 do_cache = false;
1933
1934
1935
1936
1937 if (fi && res->prefixlen < 4)
1938 fi = NULL;
1939 }
1940
1941 fnhe = NULL;
1942 do_cache &= fi != NULL;
1943 if (do_cache) {
1944 struct rtable __rcu **prth;
1945 struct fib_nh *nh = &FIB_RES_NH(*res);
1946
1947 fnhe = find_exception(nh, fl4->daddr);
1948 if (fnhe)
1949 prth = &fnhe->fnhe_rth_output;
1950 else {
1951 if (unlikely(fl4->flowi4_flags &
1952 FLOWI_FLAG_KNOWN_NH &&
1953 !(nh->nh_gw &&
1954 nh->nh_scope == RT_SCOPE_LINK))) {
1955 do_cache = false;
1956 goto add;
1957 }
1958 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
1959 }
1960 rth = rcu_dereference(*prth);
1961 if (rt_cache_valid(rth)) {
1962 dst_hold(&rth->dst);
1963 return rth;
1964 }
1965 }
1966
1967add:
1968 rth = rt_dst_alloc(dev_out,
1969 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1970 IN_DEV_CONF_GET(in_dev, NOXFRM),
1971 do_cache);
1972 if (!rth)
1973 return ERR_PTR(-ENOBUFS);
1974
1975 rth->dst.output = ip_output;
1976
1977 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out));
1978 rth->rt_flags = flags;
1979 rth->rt_type = type;
1980 rth->rt_is_input = 0;
1981 rth->rt_iif = orig_oif ? : 0;
1982 rth->rt_pmtu = 0;
1983 rth->rt_gateway = 0;
1984 rth->rt_uses_gateway = 0;
1985 INIT_LIST_HEAD(&rth->rt_uncached);
1986
1987 RT_CACHE_STAT_INC(out_slow_tot);
1988
1989 if (flags & RTCF_LOCAL)
1990 rth->dst.input = ip_local_deliver;
1991 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1992 if (flags & RTCF_LOCAL &&
1993 !(dev_out->flags & IFF_LOOPBACK)) {
1994 rth->dst.output = ip_mc_output;
1995 RT_CACHE_STAT_INC(out_slow_mc);
1996 }
1997#ifdef CONFIG_IP_MROUTE
1998 if (type == RTN_MULTICAST) {
1999 if (IN_DEV_MFORWARD(in_dev) &&
2000 !ipv4_is_local_multicast(fl4->daddr)) {
2001 rth->dst.input = ip_mr_input;
2002 rth->dst.output = ip_mc_output;
2003 }
2004 }
2005#endif
2006 }
2007
2008 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
2009
2010 return rth;
2011}
2012
2013
2014
2015
2016
2017struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
2018{
2019 struct net_device *dev_out = NULL;
2020 __u8 tos = RT_FL_TOS(fl4);
2021 unsigned int flags = 0;
2022 struct fib_result res;
2023 struct rtable *rth;
2024 int orig_oif;
2025
2026 res.tclassid = 0;
2027 res.fi = NULL;
2028 res.table = NULL;
2029
2030 orig_oif = fl4->flowi4_oif;
2031
2032 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2033 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2034 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2035 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2036
2037 rcu_read_lock();
2038 if (fl4->saddr) {
2039 rth = ERR_PTR(-EINVAL);
2040 if (ipv4_is_multicast(fl4->saddr) ||
2041 ipv4_is_lbcast(fl4->saddr) ||
2042 ipv4_is_zeronet(fl4->saddr))
2043 goto out;
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053 if (fl4->flowi4_oif == 0 &&
2054 (ipv4_is_multicast(fl4->daddr) ||
2055 ipv4_is_lbcast(fl4->daddr))) {
2056
2057 dev_out = __ip_dev_find(net, fl4->saddr, false);
2058 if (!dev_out)
2059 goto out;
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076 fl4->flowi4_oif = dev_out->ifindex;
2077 goto make_route;
2078 }
2079
2080 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2081
2082 if (!__ip_dev_find(net, fl4->saddr, false))
2083 goto out;
2084 }
2085 }
2086
2087
2088 if (fl4->flowi4_oif) {
2089 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2090 rth = ERR_PTR(-ENODEV);
2091 if (!dev_out)
2092 goto out;
2093
2094
2095 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2096 rth = ERR_PTR(-ENETUNREACH);
2097 goto out;
2098 }
2099 if (ipv4_is_local_multicast(fl4->daddr) ||
2100 ipv4_is_lbcast(fl4->daddr)) {
2101 if (!fl4->saddr)
2102 fl4->saddr = inet_select_addr(dev_out, 0,
2103 RT_SCOPE_LINK);
2104 goto make_route;
2105 }
2106 if (!fl4->saddr) {
2107 if (ipv4_is_multicast(fl4->daddr))
2108 fl4->saddr = inet_select_addr(dev_out, 0,
2109 fl4->flowi4_scope);
2110 else if (!fl4->daddr)
2111 fl4->saddr = inet_select_addr(dev_out, 0,
2112 RT_SCOPE_HOST);
2113 }
2114 }
2115
2116 if (!fl4->daddr) {
2117 fl4->daddr = fl4->saddr;
2118 if (!fl4->daddr)
2119 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2120 dev_out = net->loopback_dev;
2121 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2122 res.type = RTN_LOCAL;
2123 flags |= RTCF_LOCAL;
2124 goto make_route;
2125 }
2126
2127 if (fib_lookup(net, fl4, &res)) {
2128 res.fi = NULL;
2129 res.table = NULL;
2130 if (fl4->flowi4_oif) {
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149 if (fl4->saddr == 0)
2150 fl4->saddr = inet_select_addr(dev_out, 0,
2151 RT_SCOPE_LINK);
2152 res.type = RTN_UNICAST;
2153 goto make_route;
2154 }
2155 rth = ERR_PTR(-ENETUNREACH);
2156 goto out;
2157 }
2158
2159 if (res.type == RTN_LOCAL) {
2160 if (!fl4->saddr) {
2161 if (res.fi->fib_prefsrc)
2162 fl4->saddr = res.fi->fib_prefsrc;
2163 else
2164 fl4->saddr = fl4->daddr;
2165 }
2166 dev_out = net->loopback_dev;
2167 fl4->flowi4_oif = dev_out->ifindex;
2168 flags |= RTCF_LOCAL;
2169 goto make_route;
2170 }
2171
2172#ifdef CONFIG_IP_ROUTE_MULTIPATH
2173 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2174 fib_select_multipath(&res);
2175 else
2176#endif
2177 if (!res.prefixlen &&
2178 res.table->tb_num_default > 1 &&
2179 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2180 fib_select_default(&res);
2181
2182 if (!fl4->saddr)
2183 fl4->saddr = FIB_RES_PREFSRC(net, res);
2184
2185 dev_out = FIB_RES_DEV(res);
2186 fl4->flowi4_oif = dev_out->ifindex;
2187
2188
2189make_route:
2190 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2191
2192out:
2193 rcu_read_unlock();
2194 return rth;
2195}
2196EXPORT_SYMBOL_GPL(__ip_route_output_key);
2197
2198static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2199{
2200 return NULL;
2201}
2202
2203static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2204{
2205 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2206
2207 return mtu ? : dst->dev->mtu;
2208}
2209
2210static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2211 struct sk_buff *skb, u32 mtu)
2212{
2213}
2214
2215static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2216 struct sk_buff *skb)
2217{
2218}
2219
2220static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2221 unsigned long old)
2222{
2223 return NULL;
2224}
2225
2226static struct dst_ops ipv4_dst_blackhole_ops = {
2227 .family = AF_INET,
2228 .check = ipv4_blackhole_dst_check,
2229 .mtu = ipv4_blackhole_mtu,
2230 .default_advmss = ipv4_default_advmss,
2231 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2232 .redirect = ipv4_rt_blackhole_redirect,
2233 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2234 .neigh_lookup = ipv4_neigh_lookup,
2235};
2236
2237struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2238{
2239 struct rtable *ort = (struct rtable *) dst_orig;
2240 struct rtable *rt;
2241
2242 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2243 if (rt) {
2244 struct dst_entry *new = &rt->dst;
2245
2246 new->__use = 1;
2247 new->input = dst_discard;
2248 new->output = dst_discard_sk;
2249
2250 new->dev = ort->dst.dev;
2251 if (new->dev)
2252 dev_hold(new->dev);
2253
2254 rt->rt_is_input = ort->rt_is_input;
2255 rt->rt_iif = ort->rt_iif;
2256 rt->rt_pmtu = ort->rt_pmtu;
2257
2258 rt->rt_genid = rt_genid_ipv4(net);
2259 rt->rt_flags = ort->rt_flags;
2260 rt->rt_type = ort->rt_type;
2261 rt->rt_gateway = ort->rt_gateway;
2262 rt->rt_uses_gateway = ort->rt_uses_gateway;
2263
2264 INIT_LIST_HEAD(&rt->rt_uncached);
2265
2266 dst_free(new);
2267 }
2268
2269 dst_release(dst_orig);
2270
2271 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2272}
2273
2274struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2275 struct sock *sk)
2276{
2277 struct rtable *rt = __ip_route_output_key(net, flp4);
2278
2279 if (IS_ERR(rt))
2280 return rt;
2281
2282 if (flp4->flowi4_proto)
2283 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2284 flowi4_to_flowi(flp4),
2285 sk, 0);
2286
2287 return rt;
2288}
2289EXPORT_SYMBOL_GPL(ip_route_output_flow);
2290
2291static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2292 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2293 u32 seq, int event, int nowait, unsigned int flags)
2294{
2295 struct rtable *rt = skb_rtable(skb);
2296 struct rtmsg *r;
2297 struct nlmsghdr *nlh;
2298 unsigned long expires = 0;
2299 u32 error;
2300 u32 metrics[RTAX_MAX];
2301
2302 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2303 if (!nlh)
2304 return -EMSGSIZE;
2305
2306 r = nlmsg_data(nlh);
2307 r->rtm_family = AF_INET;
2308 r->rtm_dst_len = 32;
2309 r->rtm_src_len = 0;
2310 r->rtm_tos = fl4->flowi4_tos;
2311 r->rtm_table = RT_TABLE_MAIN;
2312 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2313 goto nla_put_failure;
2314 r->rtm_type = rt->rt_type;
2315 r->rtm_scope = RT_SCOPE_UNIVERSE;
2316 r->rtm_protocol = RTPROT_UNSPEC;
2317 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2318 if (rt->rt_flags & RTCF_NOTIFY)
2319 r->rtm_flags |= RTM_F_NOTIFY;
2320 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2321 r->rtm_flags |= RTCF_DOREDIRECT;
2322
2323 if (nla_put_in_addr(skb, RTA_DST, dst))
2324 goto nla_put_failure;
2325 if (src) {
2326 r->rtm_src_len = 32;
2327 if (nla_put_in_addr(skb, RTA_SRC, src))
2328 goto nla_put_failure;
2329 }
2330 if (rt->dst.dev &&
2331 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2332 goto nla_put_failure;
2333#ifdef CONFIG_IP_ROUTE_CLASSID
2334 if (rt->dst.tclassid &&
2335 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2336 goto nla_put_failure;
2337#endif
2338 if (!rt_is_input_route(rt) &&
2339 fl4->saddr != src) {
2340 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2341 goto nla_put_failure;
2342 }
2343 if (rt->rt_uses_gateway &&
2344 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2345 goto nla_put_failure;
2346
2347 expires = rt->dst.expires;
2348 if (expires) {
2349 unsigned long now = jiffies;
2350
2351 if (time_before(now, expires))
2352 expires -= now;
2353 else
2354 expires = 0;
2355 }
2356
2357 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2358 if (rt->rt_pmtu && expires)
2359 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2360 if (rtnetlink_put_metrics(skb, metrics) < 0)
2361 goto nla_put_failure;
2362
2363 if (fl4->flowi4_mark &&
2364 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2365 goto nla_put_failure;
2366
2367 error = rt->dst.error;
2368
2369 if (rt_is_input_route(rt)) {
2370#ifdef CONFIG_IP_MROUTE
2371 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2372 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2373 int err = ipmr_get_route(net, skb,
2374 fl4->saddr, fl4->daddr,
2375 r, nowait);
2376 if (err <= 0) {
2377 if (!nowait) {
2378 if (err == 0)
2379 return 0;
2380 goto nla_put_failure;
2381 } else {
2382 if (err == -EMSGSIZE)
2383 goto nla_put_failure;
2384 error = err;
2385 }
2386 }
2387 } else
2388#endif
2389 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2390 goto nla_put_failure;
2391 }
2392
2393 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2394 goto nla_put_failure;
2395
2396 nlmsg_end(skb, nlh);
2397 return 0;
2398
2399nla_put_failure:
2400 nlmsg_cancel(skb, nlh);
2401 return -EMSGSIZE;
2402}
2403
2404static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2405{
2406 struct net *net = sock_net(in_skb->sk);
2407 struct rtmsg *rtm;
2408 struct nlattr *tb[RTA_MAX+1];
2409 struct rtable *rt = NULL;
2410 struct flowi4 fl4;
2411 __be32 dst = 0;
2412 __be32 src = 0;
2413 u32 iif;
2414 int err;
2415 int mark;
2416 struct sk_buff *skb;
2417
2418 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2419 if (err < 0)
2420 goto errout;
2421
2422 rtm = nlmsg_data(nlh);
2423
2424 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2425 if (!skb) {
2426 err = -ENOBUFS;
2427 goto errout;
2428 }
2429
2430
2431
2432
2433 skb_reset_mac_header(skb);
2434 skb_reset_network_header(skb);
2435
2436
2437 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2438 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2439
2440 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2441 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2442 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2443 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2444
2445 memset(&fl4, 0, sizeof(fl4));
2446 fl4.daddr = dst;
2447 fl4.saddr = src;
2448 fl4.flowi4_tos = rtm->rtm_tos;
2449 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2450 fl4.flowi4_mark = mark;
2451
2452 if (iif) {
2453 struct net_device *dev;
2454
2455 dev = __dev_get_by_index(net, iif);
2456 if (!dev) {
2457 err = -ENODEV;
2458 goto errout_free;
2459 }
2460
2461 skb->protocol = htons(ETH_P_IP);
2462 skb->dev = dev;
2463 skb->mark = mark;
2464 local_bh_disable();
2465 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2466 local_bh_enable();
2467
2468 rt = skb_rtable(skb);
2469 if (err == 0 && rt->dst.error)
2470 err = -rt->dst.error;
2471 } else {
2472 rt = ip_route_output_key(net, &fl4);
2473
2474 err = 0;
2475 if (IS_ERR(rt))
2476 err = PTR_ERR(rt);
2477 }
2478
2479 if (err)
2480 goto errout_free;
2481
2482 skb_dst_set(skb, &rt->dst);
2483 if (rtm->rtm_flags & RTM_F_NOTIFY)
2484 rt->rt_flags |= RTCF_NOTIFY;
2485
2486 err = rt_fill_info(net, dst, src, &fl4, skb,
2487 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2488 RTM_NEWROUTE, 0, 0);
2489 if (err < 0)
2490 goto errout_free;
2491
2492 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2493errout:
2494 return err;
2495
2496errout_free:
2497 kfree_skb(skb);
2498 goto errout;
2499}
2500
2501void ip_rt_multicast_event(struct in_device *in_dev)
2502{
2503 rt_cache_flush(dev_net(in_dev->dev));
2504}
2505
2506#ifdef CONFIG_SYSCTL
2507static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2508static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2509static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2510static int ip_rt_gc_elasticity __read_mostly = 8;
2511
2512static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2513 void __user *buffer,
2514 size_t *lenp, loff_t *ppos)
2515{
2516 struct net *net = (struct net *)__ctl->extra1;
2517
2518 if (write) {
2519 rt_cache_flush(net);
2520 fnhe_genid_bump(net);
2521 return 0;
2522 }
2523
2524 return -EINVAL;
2525}
2526
2527static struct ctl_table ipv4_route_table[] = {
2528 {
2529 .procname = "gc_thresh",
2530 .data = &ipv4_dst_ops.gc_thresh,
2531 .maxlen = sizeof(int),
2532 .mode = 0644,
2533 .proc_handler = proc_dointvec,
2534 },
2535 {
2536 .procname = "max_size",
2537 .data = &ip_rt_max_size,
2538 .maxlen = sizeof(int),
2539 .mode = 0644,
2540 .proc_handler = proc_dointvec,
2541 },
2542 {
2543
2544
2545 .procname = "gc_min_interval",
2546 .data = &ip_rt_gc_min_interval,
2547 .maxlen = sizeof(int),
2548 .mode = 0644,
2549 .proc_handler = proc_dointvec_jiffies,
2550 },
2551 {
2552 .procname = "gc_min_interval_ms",
2553 .data = &ip_rt_gc_min_interval,
2554 .maxlen = sizeof(int),
2555 .mode = 0644,
2556 .proc_handler = proc_dointvec_ms_jiffies,
2557 },
2558 {
2559 .procname = "gc_timeout",
2560 .data = &ip_rt_gc_timeout,
2561 .maxlen = sizeof(int),
2562 .mode = 0644,
2563 .proc_handler = proc_dointvec_jiffies,
2564 },
2565 {
2566 .procname = "gc_interval",
2567 .data = &ip_rt_gc_interval,
2568 .maxlen = sizeof(int),
2569 .mode = 0644,
2570 .proc_handler = proc_dointvec_jiffies,
2571 },
2572 {
2573 .procname = "redirect_load",
2574 .data = &ip_rt_redirect_load,
2575 .maxlen = sizeof(int),
2576 .mode = 0644,
2577 .proc_handler = proc_dointvec,
2578 },
2579 {
2580 .procname = "redirect_number",
2581 .data = &ip_rt_redirect_number,
2582 .maxlen = sizeof(int),
2583 .mode = 0644,
2584 .proc_handler = proc_dointvec,
2585 },
2586 {
2587 .procname = "redirect_silence",
2588 .data = &ip_rt_redirect_silence,
2589 .maxlen = sizeof(int),
2590 .mode = 0644,
2591 .proc_handler = proc_dointvec,
2592 },
2593 {
2594 .procname = "error_cost",
2595 .data = &ip_rt_error_cost,
2596 .maxlen = sizeof(int),
2597 .mode = 0644,
2598 .proc_handler = proc_dointvec,
2599 },
2600 {
2601 .procname = "error_burst",
2602 .data = &ip_rt_error_burst,
2603 .maxlen = sizeof(int),
2604 .mode = 0644,
2605 .proc_handler = proc_dointvec,
2606 },
2607 {
2608 .procname = "gc_elasticity",
2609 .data = &ip_rt_gc_elasticity,
2610 .maxlen = sizeof(int),
2611 .mode = 0644,
2612 .proc_handler = proc_dointvec,
2613 },
2614 {
2615 .procname = "mtu_expires",
2616 .data = &ip_rt_mtu_expires,
2617 .maxlen = sizeof(int),
2618 .mode = 0644,
2619 .proc_handler = proc_dointvec_jiffies,
2620 },
2621 {
2622 .procname = "min_pmtu",
2623 .data = &ip_rt_min_pmtu,
2624 .maxlen = sizeof(int),
2625 .mode = 0644,
2626 .proc_handler = proc_dointvec,
2627 },
2628 {
2629 .procname = "min_adv_mss",
2630 .data = &ip_rt_min_advmss,
2631 .maxlen = sizeof(int),
2632 .mode = 0644,
2633 .proc_handler = proc_dointvec,
2634 },
2635 { }
2636};
2637
2638static struct ctl_table ipv4_route_flush_table[] = {
2639 {
2640 .procname = "flush",
2641 .maxlen = sizeof(int),
2642 .mode = 0200,
2643 .proc_handler = ipv4_sysctl_rtcache_flush,
2644 },
2645 { },
2646};
2647
2648static __net_init int sysctl_route_net_init(struct net *net)
2649{
2650 struct ctl_table *tbl;
2651
2652 tbl = ipv4_route_flush_table;
2653 if (!net_eq(net, &init_net)) {
2654 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2655 if (!tbl)
2656 goto err_dup;
2657
2658
2659 if (net->user_ns != &init_user_ns)
2660 tbl[0].procname = NULL;
2661 }
2662 tbl[0].extra1 = net;
2663
2664 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2665 if (!net->ipv4.route_hdr)
2666 goto err_reg;
2667 return 0;
2668
2669err_reg:
2670 if (tbl != ipv4_route_flush_table)
2671 kfree(tbl);
2672err_dup:
2673 return -ENOMEM;
2674}
2675
2676static __net_exit void sysctl_route_net_exit(struct net *net)
2677{
2678 struct ctl_table *tbl;
2679
2680 tbl = net->ipv4.route_hdr->ctl_table_arg;
2681 unregister_net_sysctl_table(net->ipv4.route_hdr);
2682 BUG_ON(tbl == ipv4_route_flush_table);
2683 kfree(tbl);
2684}
2685
2686static __net_initdata struct pernet_operations sysctl_route_ops = {
2687 .init = sysctl_route_net_init,
2688 .exit = sysctl_route_net_exit,
2689};
2690#endif
2691
2692static __net_init int rt_genid_init(struct net *net)
2693{
2694 atomic_set(&net->ipv4.rt_genid, 0);
2695 atomic_set(&net->fnhe_genid, 0);
2696 get_random_bytes(&net->ipv4.dev_addr_genid,
2697 sizeof(net->ipv4.dev_addr_genid));
2698 return 0;
2699}
2700
2701static __net_initdata struct pernet_operations rt_genid_ops = {
2702 .init = rt_genid_init,
2703};
2704
2705static int __net_init ipv4_inetpeer_init(struct net *net)
2706{
2707 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2708
2709 if (!bp)
2710 return -ENOMEM;
2711 inet_peer_base_init(bp);
2712 net->ipv4.peers = bp;
2713 return 0;
2714}
2715
2716static void __net_exit ipv4_inetpeer_exit(struct net *net)
2717{
2718 struct inet_peer_base *bp = net->ipv4.peers;
2719
2720 net->ipv4.peers = NULL;
2721 inetpeer_invalidate_tree(bp);
2722 kfree(bp);
2723}
2724
2725static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2726 .init = ipv4_inetpeer_init,
2727 .exit = ipv4_inetpeer_exit,
2728};
2729
2730#ifdef CONFIG_IP_ROUTE_CLASSID
2731struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2732#endif
2733
2734int __init ip_rt_init(void)
2735{
2736 int rc = 0;
2737 int cpu;
2738
2739 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2740 if (!ip_idents)
2741 panic("IP: failed to allocate ip_idents\n");
2742
2743 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2744
2745 for_each_possible_cpu(cpu) {
2746 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
2747
2748 INIT_LIST_HEAD(&ul->head);
2749 spin_lock_init(&ul->lock);
2750 }
2751#ifdef CONFIG_IP_ROUTE_CLASSID
2752 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2753 if (!ip_rt_acct)
2754 panic("IP: failed to allocate ip_rt_acct\n");
2755#endif
2756
2757 ipv4_dst_ops.kmem_cachep =
2758 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2759 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2760
2761 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2762
2763 if (dst_entries_init(&ipv4_dst_ops) < 0)
2764 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2765
2766 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2767 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2768
2769 ipv4_dst_ops.gc_thresh = ~0;
2770 ip_rt_max_size = INT_MAX;
2771
2772 devinet_init();
2773 ip_fib_init();
2774
2775 if (ip_rt_proc_init())
2776 pr_err("Unable to create route proc files\n");
2777#ifdef CONFIG_XFRM
2778 xfrm_init();
2779 xfrm4_init();
2780#endif
2781 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2782
2783#ifdef CONFIG_SYSCTL
2784 register_pernet_subsys(&sysctl_route_ops);
2785#endif
2786 register_pernet_subsys(&rt_genid_ops);
2787 register_pernet_subsys(&ipv4_inetpeer_ops);
2788 return rc;
2789}
2790
2791#ifdef CONFIG_SYSCTL
2792
2793
2794
2795
2796void __init ip_static_sysctl_init(void)
2797{
2798 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2799}
2800#endif
2801