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1 /*
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.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
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>
13 *
14 * Fixes:
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
24 * clamper.
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.
39 *
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
58 *
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.
63 */
64
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 <net/dst.h>
93 #include <net/net_namespace.h>
94 #include <net/protocol.h>
95 #include <net/ip.h>
96 #include <net/route.h>
97 #include <net/inetpeer.h>
98 #include <net/sock.h>
99 #include <net/ip_fib.h>
100 #include <net/arp.h>
101 #include <net/tcp.h>
102 #include <net/icmp.h>
103 #include <net/xfrm.h>
104 #include <net/netevent.h>
105 #include <net/rtnetlink.h>
106 #ifdef CONFIG_SYSCTL
107 #include <linux/sysctl.h>
108 #include <linux/kmemleak.h>
109 #endif
110 #include <net/secure_seq.h>
111
112 #define RT_FL_TOS(oldflp4) \
113 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
114
115 #define IP_MAX_MTU 0xFFF0
116
117 #define RT_GC_TIMEOUT (300*HZ)
118
119 static int ip_rt_max_size;
120 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
121 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
122 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
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_gc_elasticity __read_mostly = 8;
129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
130 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly = 256;
132
133 /*
134 * Interface to generic destination cache.
135 */
136
137 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
138 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
139 static unsigned int ipv4_mtu(const struct dst_entry *dst);
140 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
141 static void ipv4_link_failure(struct sk_buff *skb);
142 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
143 struct sk_buff *skb, u32 mtu);
144 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
145 struct sk_buff *skb);
146 static void ipv4_dst_destroy(struct dst_entry *dst);
147
148 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
149 int how)
150 {
151 }
152
153 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
154 {
155 WARN_ON(1);
156 return NULL;
157 }
158
159 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
160 struct sk_buff *skb,
161 const void *daddr);
162
163 static struct dst_ops ipv4_dst_ops = {
164 .family = AF_INET,
165 .protocol = cpu_to_be16(ETH_P_IP),
166 .check = ipv4_dst_check,
167 .default_advmss = ipv4_default_advmss,
168 .mtu = ipv4_mtu,
169 .cow_metrics = ipv4_cow_metrics,
170 .destroy = ipv4_dst_destroy,
171 .ifdown = ipv4_dst_ifdown,
172 .negative_advice = ipv4_negative_advice,
173 .link_failure = ipv4_link_failure,
174 .update_pmtu = ip_rt_update_pmtu,
175 .redirect = ip_do_redirect,
176 .local_out = __ip_local_out,
177 .neigh_lookup = ipv4_neigh_lookup,
178 };
179
180 #define ECN_OR_COST(class) TC_PRIO_##class
181
182 const __u8 ip_tos2prio[16] = {
183 TC_PRIO_BESTEFFORT,
184 ECN_OR_COST(BESTEFFORT),
185 TC_PRIO_BESTEFFORT,
186 ECN_OR_COST(BESTEFFORT),
187 TC_PRIO_BULK,
188 ECN_OR_COST(BULK),
189 TC_PRIO_BULK,
190 ECN_OR_COST(BULK),
191 TC_PRIO_INTERACTIVE,
192 ECN_OR_COST(INTERACTIVE),
193 TC_PRIO_INTERACTIVE,
194 ECN_OR_COST(INTERACTIVE),
195 TC_PRIO_INTERACTIVE_BULK,
196 ECN_OR_COST(INTERACTIVE_BULK),
197 TC_PRIO_INTERACTIVE_BULK,
198 ECN_OR_COST(INTERACTIVE_BULK)
199 };
200 EXPORT_SYMBOL(ip_tos2prio);
201
202 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
203 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
204
205 #ifdef CONFIG_PROC_FS
206 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
207 {
208 if (*pos)
209 return NULL;
210 return SEQ_START_TOKEN;
211 }
212
213 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
214 {
215 ++*pos;
216 return NULL;
217 }
218
219 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
220 {
221 }
222
223 static int rt_cache_seq_show(struct seq_file *seq, void *v)
224 {
225 if (v == SEQ_START_TOKEN)
226 seq_printf(seq, "%-127s\n",
227 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
228 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
229 "HHUptod\tSpecDst");
230 return 0;
231 }
232
233 static const struct seq_operations rt_cache_seq_ops = {
234 .start = rt_cache_seq_start,
235 .next = rt_cache_seq_next,
236 .stop = rt_cache_seq_stop,
237 .show = rt_cache_seq_show,
238 };
239
240 static int rt_cache_seq_open(struct inode *inode, struct file *file)
241 {
242 return seq_open(file, &rt_cache_seq_ops);
243 }
244
245 static const struct file_operations rt_cache_seq_fops = {
246 .owner = THIS_MODULE,
247 .open = rt_cache_seq_open,
248 .read = seq_read,
249 .llseek = seq_lseek,
250 .release = seq_release,
251 };
252
253
254 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
255 {
256 int cpu;
257
258 if (*pos == 0)
259 return SEQ_START_TOKEN;
260
261 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
262 if (!cpu_possible(cpu))
263 continue;
264 *pos = cpu+1;
265 return &per_cpu(rt_cache_stat, cpu);
266 }
267 return NULL;
268 }
269
270 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
271 {
272 int cpu;
273
274 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
275 if (!cpu_possible(cpu))
276 continue;
277 *pos = cpu+1;
278 return &per_cpu(rt_cache_stat, cpu);
279 }
280 return NULL;
281
282 }
283
284 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
285 {
286
287 }
288
289 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
290 {
291 struct rt_cache_stat *st = v;
292
293 if (v == SEQ_START_TOKEN) {
294 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");
295 return 0;
296 }
297
298 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
299 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
300 dst_entries_get_slow(&ipv4_dst_ops),
301 st->in_hit,
302 st->in_slow_tot,
303 st->in_slow_mc,
304 st->in_no_route,
305 st->in_brd,
306 st->in_martian_dst,
307 st->in_martian_src,
308
309 st->out_hit,
310 st->out_slow_tot,
311 st->out_slow_mc,
312
313 st->gc_total,
314 st->gc_ignored,
315 st->gc_goal_miss,
316 st->gc_dst_overflow,
317 st->in_hlist_search,
318 st->out_hlist_search
319 );
320 return 0;
321 }
322
323 static const struct seq_operations rt_cpu_seq_ops = {
324 .start = rt_cpu_seq_start,
325 .next = rt_cpu_seq_next,
326 .stop = rt_cpu_seq_stop,
327 .show = rt_cpu_seq_show,
328 };
329
330
331 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
332 {
333 return seq_open(file, &rt_cpu_seq_ops);
334 }
335
336 static const struct file_operations rt_cpu_seq_fops = {
337 .owner = THIS_MODULE,
338 .open = rt_cpu_seq_open,
339 .read = seq_read,
340 .llseek = seq_lseek,
341 .release = seq_release,
342 };
343
344 #ifdef CONFIG_IP_ROUTE_CLASSID
345 static int rt_acct_proc_show(struct seq_file *m, void *v)
346 {
347 struct ip_rt_acct *dst, *src;
348 unsigned int i, j;
349
350 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
351 if (!dst)
352 return -ENOMEM;
353
354 for_each_possible_cpu(i) {
355 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
356 for (j = 0; j < 256; j++) {
357 dst[j].o_bytes += src[j].o_bytes;
358 dst[j].o_packets += src[j].o_packets;
359 dst[j].i_bytes += src[j].i_bytes;
360 dst[j].i_packets += src[j].i_packets;
361 }
362 }
363
364 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
365 kfree(dst);
366 return 0;
367 }
368
369 static int rt_acct_proc_open(struct inode *inode, struct file *file)
370 {
371 return single_open(file, rt_acct_proc_show, NULL);
372 }
373
374 static const struct file_operations rt_acct_proc_fops = {
375 .owner = THIS_MODULE,
376 .open = rt_acct_proc_open,
377 .read = seq_read,
378 .llseek = seq_lseek,
379 .release = single_release,
380 };
381 #endif
382
383 static int __net_init ip_rt_do_proc_init(struct net *net)
384 {
385 struct proc_dir_entry *pde;
386
387 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
388 &rt_cache_seq_fops);
389 if (!pde)
390 goto err1;
391
392 pde = proc_create("rt_cache", S_IRUGO,
393 net->proc_net_stat, &rt_cpu_seq_fops);
394 if (!pde)
395 goto err2;
396
397 #ifdef CONFIG_IP_ROUTE_CLASSID
398 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
399 if (!pde)
400 goto err3;
401 #endif
402 return 0;
403
404 #ifdef CONFIG_IP_ROUTE_CLASSID
405 err3:
406 remove_proc_entry("rt_cache", net->proc_net_stat);
407 #endif
408 err2:
409 remove_proc_entry("rt_cache", net->proc_net);
410 err1:
411 return -ENOMEM;
412 }
413
414 static void __net_exit ip_rt_do_proc_exit(struct net *net)
415 {
416 remove_proc_entry("rt_cache", net->proc_net_stat);
417 remove_proc_entry("rt_cache", net->proc_net);
418 #ifdef CONFIG_IP_ROUTE_CLASSID
419 remove_proc_entry("rt_acct", net->proc_net);
420 #endif
421 }
422
423 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
424 .init = ip_rt_do_proc_init,
425 .exit = ip_rt_do_proc_exit,
426 };
427
428 static int __init ip_rt_proc_init(void)
429 {
430 return register_pernet_subsys(&ip_rt_proc_ops);
431 }
432
433 #else
434 static inline int ip_rt_proc_init(void)
435 {
436 return 0;
437 }
438 #endif /* CONFIG_PROC_FS */
439
440 static inline bool rt_is_expired(const struct rtable *rth)
441 {
442 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
443 }
444
445 void rt_cache_flush(struct net *net)
446 {
447 rt_genid_bump(net);
448 }
449
450 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
451 struct sk_buff *skb,
452 const void *daddr)
453 {
454 struct net_device *dev = dst->dev;
455 const __be32 *pkey = daddr;
456 const struct rtable *rt;
457 struct neighbour *n;
458
459 rt = (const struct rtable *) dst;
460 if (rt->rt_gateway)
461 pkey = (const __be32 *) &rt->rt_gateway;
462 else if (skb)
463 pkey = &ip_hdr(skb)->daddr;
464
465 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
466 if (n)
467 return n;
468 return neigh_create(&arp_tbl, pkey, dev);
469 }
470
471 /*
472 * Peer allocation may fail only in serious out-of-memory conditions. However
473 * we still can generate some output.
474 * Random ID selection looks a bit dangerous because we have no chances to
475 * select ID being unique in a reasonable period of time.
476 * But broken packet identifier may be better than no packet at all.
477 */
478 static void ip_select_fb_ident(struct iphdr *iph)
479 {
480 static DEFINE_SPINLOCK(ip_fb_id_lock);
481 static u32 ip_fallback_id;
482 u32 salt;
483
484 spin_lock_bh(&ip_fb_id_lock);
485 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
486 iph->id = htons(salt & 0xFFFF);
487 ip_fallback_id = salt;
488 spin_unlock_bh(&ip_fb_id_lock);
489 }
490
491 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
492 {
493 struct net *net = dev_net(dst->dev);
494 struct inet_peer *peer;
495
496 peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1);
497 if (peer) {
498 iph->id = htons(inet_getid(peer, more));
499 inet_putpeer(peer);
500 return;
501 }
502
503 ip_select_fb_ident(iph);
504 }
505 EXPORT_SYMBOL(__ip_select_ident);
506
507 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
508 const struct iphdr *iph,
509 int oif, u8 tos,
510 u8 prot, u32 mark, int flow_flags)
511 {
512 if (sk) {
513 const struct inet_sock *inet = inet_sk(sk);
514
515 oif = sk->sk_bound_dev_if;
516 mark = sk->sk_mark;
517 tos = RT_CONN_FLAGS(sk);
518 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
519 }
520 flowi4_init_output(fl4, oif, mark, tos,
521 RT_SCOPE_UNIVERSE, prot,
522 flow_flags,
523 iph->daddr, iph->saddr, 0, 0);
524 }
525
526 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
527 const struct sock *sk)
528 {
529 const struct iphdr *iph = ip_hdr(skb);
530 int oif = skb->dev->ifindex;
531 u8 tos = RT_TOS(iph->tos);
532 u8 prot = iph->protocol;
533 u32 mark = skb->mark;
534
535 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
536 }
537
538 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
539 {
540 const struct inet_sock *inet = inet_sk(sk);
541 const struct ip_options_rcu *inet_opt;
542 __be32 daddr = inet->inet_daddr;
543
544 rcu_read_lock();
545 inet_opt = rcu_dereference(inet->inet_opt);
546 if (inet_opt && inet_opt->opt.srr)
547 daddr = inet_opt->opt.faddr;
548 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
549 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
550 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
551 inet_sk_flowi_flags(sk),
552 daddr, inet->inet_saddr, 0, 0);
553 rcu_read_unlock();
554 }
555
556 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
557 const struct sk_buff *skb)
558 {
559 if (skb)
560 build_skb_flow_key(fl4, skb, sk);
561 else
562 build_sk_flow_key(fl4, sk);
563 }
564
565 static inline void rt_free(struct rtable *rt)
566 {
567 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
568 }
569
570 static DEFINE_SPINLOCK(fnhe_lock);
571
572 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
573 {
574 struct fib_nh_exception *fnhe, *oldest;
575 struct rtable *orig;
576
577 oldest = rcu_dereference(hash->chain);
578 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
579 fnhe = rcu_dereference(fnhe->fnhe_next)) {
580 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
581 oldest = fnhe;
582 }
583 orig = rcu_dereference(oldest->fnhe_rth);
584 if (orig) {
585 RCU_INIT_POINTER(oldest->fnhe_rth, NULL);
586 rt_free(orig);
587 }
588 return oldest;
589 }
590
591 static inline u32 fnhe_hashfun(__be32 daddr)
592 {
593 u32 hval;
594
595 hval = (__force u32) daddr;
596 hval ^= (hval >> 11) ^ (hval >> 22);
597
598 return hval & (FNHE_HASH_SIZE - 1);
599 }
600
601 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
602 u32 pmtu, unsigned long expires)
603 {
604 struct fnhe_hash_bucket *hash;
605 struct fib_nh_exception *fnhe;
606 int depth;
607 u32 hval = fnhe_hashfun(daddr);
608
609 spin_lock_bh(&fnhe_lock);
610
611 hash = nh->nh_exceptions;
612 if (!hash) {
613 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
614 if (!hash)
615 goto out_unlock;
616 nh->nh_exceptions = hash;
617 }
618
619 hash += hval;
620
621 depth = 0;
622 for (fnhe = rcu_dereference(hash->chain); fnhe;
623 fnhe = rcu_dereference(fnhe->fnhe_next)) {
624 if (fnhe->fnhe_daddr == daddr)
625 break;
626 depth++;
627 }
628
629 if (fnhe) {
630 if (gw)
631 fnhe->fnhe_gw = gw;
632 if (pmtu) {
633 fnhe->fnhe_pmtu = pmtu;
634 fnhe->fnhe_expires = expires;
635 }
636 } else {
637 if (depth > FNHE_RECLAIM_DEPTH)
638 fnhe = fnhe_oldest(hash);
639 else {
640 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
641 if (!fnhe)
642 goto out_unlock;
643
644 fnhe->fnhe_next = hash->chain;
645 rcu_assign_pointer(hash->chain, fnhe);
646 }
647 fnhe->fnhe_daddr = daddr;
648 fnhe->fnhe_gw = gw;
649 fnhe->fnhe_pmtu = pmtu;
650 fnhe->fnhe_expires = expires;
651 }
652
653 fnhe->fnhe_stamp = jiffies;
654
655 out_unlock:
656 spin_unlock_bh(&fnhe_lock);
657 return;
658 }
659
660 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
661 bool kill_route)
662 {
663 __be32 new_gw = icmp_hdr(skb)->un.gateway;
664 __be32 old_gw = ip_hdr(skb)->saddr;
665 struct net_device *dev = skb->dev;
666 struct in_device *in_dev;
667 struct fib_result res;
668 struct neighbour *n;
669 struct net *net;
670
671 switch (icmp_hdr(skb)->code & 7) {
672 case ICMP_REDIR_NET:
673 case ICMP_REDIR_NETTOS:
674 case ICMP_REDIR_HOST:
675 case ICMP_REDIR_HOSTTOS:
676 break;
677
678 default:
679 return;
680 }
681
682 if (rt->rt_gateway != old_gw)
683 return;
684
685 in_dev = __in_dev_get_rcu(dev);
686 if (!in_dev)
687 return;
688
689 net = dev_net(dev);
690 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
691 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
692 ipv4_is_zeronet(new_gw))
693 goto reject_redirect;
694
695 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
696 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
697 goto reject_redirect;
698 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
699 goto reject_redirect;
700 } else {
701 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
702 goto reject_redirect;
703 }
704
705 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
706 if (n) {
707 if (!(n->nud_state & NUD_VALID)) {
708 neigh_event_send(n, NULL);
709 } else {
710 if (fib_lookup(net, fl4, &res) == 0) {
711 struct fib_nh *nh = &FIB_RES_NH(res);
712
713 update_or_create_fnhe(nh, fl4->daddr, new_gw,
714 0, 0);
715 }
716 if (kill_route)
717 rt->dst.obsolete = DST_OBSOLETE_KILL;
718 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
719 }
720 neigh_release(n);
721 }
722 return;
723
724 reject_redirect:
725 #ifdef CONFIG_IP_ROUTE_VERBOSE
726 if (IN_DEV_LOG_MARTIANS(in_dev)) {
727 const struct iphdr *iph = (const struct iphdr *) skb->data;
728 __be32 daddr = iph->daddr;
729 __be32 saddr = iph->saddr;
730
731 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
732 " Advised path = %pI4 -> %pI4\n",
733 &old_gw, dev->name, &new_gw,
734 &saddr, &daddr);
735 }
736 #endif
737 ;
738 }
739
740 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
741 {
742 struct rtable *rt;
743 struct flowi4 fl4;
744
745 rt = (struct rtable *) dst;
746
747 ip_rt_build_flow_key(&fl4, sk, skb);
748 __ip_do_redirect(rt, skb, &fl4, true);
749 }
750
751 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
752 {
753 struct rtable *rt = (struct rtable *)dst;
754 struct dst_entry *ret = dst;
755
756 if (rt) {
757 if (dst->obsolete > 0) {
758 ip_rt_put(rt);
759 ret = NULL;
760 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
761 rt->dst.expires) {
762 ip_rt_put(rt);
763 ret = NULL;
764 }
765 }
766 return ret;
767 }
768
769 /*
770 * Algorithm:
771 * 1. The first ip_rt_redirect_number redirects are sent
772 * with exponential backoff, then we stop sending them at all,
773 * assuming that the host ignores our redirects.
774 * 2. If we did not see packets requiring redirects
775 * during ip_rt_redirect_silence, we assume that the host
776 * forgot redirected route and start to send redirects again.
777 *
778 * This algorithm is much cheaper and more intelligent than dumb load limiting
779 * in icmp.c.
780 *
781 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
782 * and "frag. need" (breaks PMTU discovery) in icmp.c.
783 */
784
785 void ip_rt_send_redirect(struct sk_buff *skb)
786 {
787 struct rtable *rt = skb_rtable(skb);
788 struct in_device *in_dev;
789 struct inet_peer *peer;
790 struct net *net;
791 int log_martians;
792
793 rcu_read_lock();
794 in_dev = __in_dev_get_rcu(rt->dst.dev);
795 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
796 rcu_read_unlock();
797 return;
798 }
799 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
800 rcu_read_unlock();
801
802 net = dev_net(rt->dst.dev);
803 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
804 if (!peer) {
805 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
806 rt_nexthop(rt, ip_hdr(skb)->daddr));
807 return;
808 }
809
810 /* No redirected packets during ip_rt_redirect_silence;
811 * reset the algorithm.
812 */
813 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
814 peer->rate_tokens = 0;
815
816 /* Too many ignored redirects; do not send anything
817 * set dst.rate_last to the last seen redirected packet.
818 */
819 if (peer->rate_tokens >= ip_rt_redirect_number) {
820 peer->rate_last = jiffies;
821 goto out_put_peer;
822 }
823
824 /* Check for load limit; set rate_last to the latest sent
825 * redirect.
826 */
827 if (peer->rate_tokens == 0 ||
828 time_after(jiffies,
829 (peer->rate_last +
830 (ip_rt_redirect_load << peer->rate_tokens)))) {
831 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
832
833 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
834 peer->rate_last = jiffies;
835 ++peer->rate_tokens;
836 #ifdef CONFIG_IP_ROUTE_VERBOSE
837 if (log_martians &&
838 peer->rate_tokens == ip_rt_redirect_number)
839 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
840 &ip_hdr(skb)->saddr, inet_iif(skb),
841 &ip_hdr(skb)->daddr, &gw);
842 #endif
843 }
844 out_put_peer:
845 inet_putpeer(peer);
846 }
847
848 static int ip_error(struct sk_buff *skb)
849 {
850 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
851 struct rtable *rt = skb_rtable(skb);
852 struct inet_peer *peer;
853 unsigned long now;
854 struct net *net;
855 bool send;
856 int code;
857
858 net = dev_net(rt->dst.dev);
859 if (!IN_DEV_FORWARD(in_dev)) {
860 switch (rt->dst.error) {
861 case EHOSTUNREACH:
862 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
863 break;
864
865 case ENETUNREACH:
866 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
867 break;
868 }
869 goto out;
870 }
871
872 switch (rt->dst.error) {
873 case EINVAL:
874 default:
875 goto out;
876 case EHOSTUNREACH:
877 code = ICMP_HOST_UNREACH;
878 break;
879 case ENETUNREACH:
880 code = ICMP_NET_UNREACH;
881 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
882 break;
883 case EACCES:
884 code = ICMP_PKT_FILTERED;
885 break;
886 }
887
888 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
889
890 send = true;
891 if (peer) {
892 now = jiffies;
893 peer->rate_tokens += now - peer->rate_last;
894 if (peer->rate_tokens > ip_rt_error_burst)
895 peer->rate_tokens = ip_rt_error_burst;
896 peer->rate_last = now;
897 if (peer->rate_tokens >= ip_rt_error_cost)
898 peer->rate_tokens -= ip_rt_error_cost;
899 else
900 send = false;
901 inet_putpeer(peer);
902 }
903 if (send)
904 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
905
906 out: kfree_skb(skb);
907 return 0;
908 }
909
910 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
911 {
912 struct dst_entry *dst = &rt->dst;
913 struct fib_result res;
914
915 if (dst->dev->mtu < mtu)
916 return;
917
918 if (mtu < ip_rt_min_pmtu)
919 mtu = ip_rt_min_pmtu;
920
921 if (!rt->rt_pmtu) {
922 dst->obsolete = DST_OBSOLETE_KILL;
923 } else {
924 rt->rt_pmtu = mtu;
925 dst->expires = max(1UL, jiffies + ip_rt_mtu_expires);
926 }
927
928 rcu_read_lock();
929 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
930 struct fib_nh *nh = &FIB_RES_NH(res);
931
932 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
933 jiffies + ip_rt_mtu_expires);
934 }
935 rcu_read_unlock();
936 }
937
938 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
939 struct sk_buff *skb, u32 mtu)
940 {
941 struct rtable *rt = (struct rtable *) dst;
942 struct flowi4 fl4;
943
944 ip_rt_build_flow_key(&fl4, sk, skb);
945 __ip_rt_update_pmtu(rt, &fl4, mtu);
946 }
947
948 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
949 int oif, u32 mark, u8 protocol, int flow_flags)
950 {
951 const struct iphdr *iph = (const struct iphdr *) skb->data;
952 struct flowi4 fl4;
953 struct rtable *rt;
954
955 __build_flow_key(&fl4, NULL, iph, oif,
956 RT_TOS(iph->tos), protocol, mark, flow_flags);
957 rt = __ip_route_output_key(net, &fl4);
958 if (!IS_ERR(rt)) {
959 __ip_rt_update_pmtu(rt, &fl4, mtu);
960 ip_rt_put(rt);
961 }
962 }
963 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
964
965 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
966 {
967 const struct iphdr *iph = (const struct iphdr *) skb->data;
968 struct flowi4 fl4;
969 struct rtable *rt;
970
971 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
972 rt = __ip_route_output_key(sock_net(sk), &fl4);
973 if (!IS_ERR(rt)) {
974 __ip_rt_update_pmtu(rt, &fl4, mtu);
975 ip_rt_put(rt);
976 }
977 }
978 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
979
980 void ipv4_redirect(struct sk_buff *skb, struct net *net,
981 int oif, u32 mark, u8 protocol, int flow_flags)
982 {
983 const struct iphdr *iph = (const struct iphdr *) skb->data;
984 struct flowi4 fl4;
985 struct rtable *rt;
986
987 __build_flow_key(&fl4, NULL, iph, oif,
988 RT_TOS(iph->tos), protocol, mark, flow_flags);
989 rt = __ip_route_output_key(net, &fl4);
990 if (!IS_ERR(rt)) {
991 __ip_do_redirect(rt, skb, &fl4, false);
992 ip_rt_put(rt);
993 }
994 }
995 EXPORT_SYMBOL_GPL(ipv4_redirect);
996
997 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
998 {
999 const struct iphdr *iph = (const struct iphdr *) skb->data;
1000 struct flowi4 fl4;
1001 struct rtable *rt;
1002
1003 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1004 rt = __ip_route_output_key(sock_net(sk), &fl4);
1005 if (!IS_ERR(rt)) {
1006 __ip_do_redirect(rt, skb, &fl4, false);
1007 ip_rt_put(rt);
1008 }
1009 }
1010 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1011
1012 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1013 {
1014 struct rtable *rt = (struct rtable *) dst;
1015
1016 /* All IPV4 dsts are created with ->obsolete set to the value
1017 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1018 * into this function always.
1019 *
1020 * When a PMTU/redirect information update invalidates a
1021 * route, this is indicated by setting obsolete to
1022 * DST_OBSOLETE_KILL.
1023 */
1024 if (dst->obsolete == DST_OBSOLETE_KILL || rt_is_expired(rt))
1025 return NULL;
1026 return dst;
1027 }
1028
1029 static void ipv4_link_failure(struct sk_buff *skb)
1030 {
1031 struct rtable *rt;
1032
1033 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1034
1035 rt = skb_rtable(skb);
1036 if (rt)
1037 dst_set_expires(&rt->dst, 0);
1038 }
1039
1040 static int ip_rt_bug(struct sk_buff *skb)
1041 {
1042 pr_debug("%s: %pI4 -> %pI4, %s\n",
1043 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1044 skb->dev ? skb->dev->name : "?");
1045 kfree_skb(skb);
1046 WARN_ON(1);
1047 return 0;
1048 }
1049
1050 /*
1051 We do not cache source address of outgoing interface,
1052 because it is used only by IP RR, TS and SRR options,
1053 so that it out of fast path.
1054
1055 BTW remember: "addr" is allowed to be not aligned
1056 in IP options!
1057 */
1058
1059 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1060 {
1061 __be32 src;
1062
1063 if (rt_is_output_route(rt))
1064 src = ip_hdr(skb)->saddr;
1065 else {
1066 struct fib_result res;
1067 struct flowi4 fl4;
1068 struct iphdr *iph;
1069
1070 iph = ip_hdr(skb);
1071
1072 memset(&fl4, 0, sizeof(fl4));
1073 fl4.daddr = iph->daddr;
1074 fl4.saddr = iph->saddr;
1075 fl4.flowi4_tos = RT_TOS(iph->tos);
1076 fl4.flowi4_oif = rt->dst.dev->ifindex;
1077 fl4.flowi4_iif = skb->dev->ifindex;
1078 fl4.flowi4_mark = skb->mark;
1079
1080 rcu_read_lock();
1081 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1082 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1083 else
1084 src = inet_select_addr(rt->dst.dev,
1085 rt_nexthop(rt, iph->daddr),
1086 RT_SCOPE_UNIVERSE);
1087 rcu_read_unlock();
1088 }
1089 memcpy(addr, &src, 4);
1090 }
1091
1092 #ifdef CONFIG_IP_ROUTE_CLASSID
1093 static void set_class_tag(struct rtable *rt, u32 tag)
1094 {
1095 if (!(rt->dst.tclassid & 0xFFFF))
1096 rt->dst.tclassid |= tag & 0xFFFF;
1097 if (!(rt->dst.tclassid & 0xFFFF0000))
1098 rt->dst.tclassid |= tag & 0xFFFF0000;
1099 }
1100 #endif
1101
1102 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1103 {
1104 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1105
1106 if (advmss == 0) {
1107 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1108 ip_rt_min_advmss);
1109 if (advmss > 65535 - 40)
1110 advmss = 65535 - 40;
1111 }
1112 return advmss;
1113 }
1114
1115 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1116 {
1117 const struct rtable *rt = (const struct rtable *) dst;
1118 unsigned int mtu = rt->rt_pmtu;
1119
1120 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1121 mtu = dst_metric_raw(dst, RTAX_MTU);
1122
1123 if (mtu && rt_is_output_route(rt))
1124 return mtu;
1125
1126 mtu = dst->dev->mtu;
1127
1128 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1129 if (rt->rt_uses_gateway && mtu > 576)
1130 mtu = 576;
1131 }
1132
1133 if (mtu > IP_MAX_MTU)
1134 mtu = IP_MAX_MTU;
1135
1136 return mtu;
1137 }
1138
1139 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1140 {
1141 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1142 struct fib_nh_exception *fnhe;
1143 u32 hval;
1144
1145 if (!hash)
1146 return NULL;
1147
1148 hval = fnhe_hashfun(daddr);
1149
1150 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1151 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1152 if (fnhe->fnhe_daddr == daddr)
1153 return fnhe;
1154 }
1155 return NULL;
1156 }
1157
1158 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1159 __be32 daddr)
1160 {
1161 bool ret = false;
1162
1163 spin_lock_bh(&fnhe_lock);
1164
1165 if (daddr == fnhe->fnhe_daddr) {
1166 struct rtable *orig;
1167
1168 if (fnhe->fnhe_pmtu) {
1169 unsigned long expires = fnhe->fnhe_expires;
1170 unsigned long diff = expires - jiffies;
1171
1172 if (time_before(jiffies, expires)) {
1173 rt->rt_pmtu = fnhe->fnhe_pmtu;
1174 dst_set_expires(&rt->dst, diff);
1175 }
1176 }
1177 if (fnhe->fnhe_gw) {
1178 rt->rt_flags |= RTCF_REDIRECTED;
1179 rt->rt_gateway = fnhe->fnhe_gw;
1180 rt->rt_uses_gateway = 1;
1181 } else if (!rt->rt_gateway)
1182 rt->rt_gateway = daddr;
1183
1184 orig = rcu_dereference(fnhe->fnhe_rth);
1185 rcu_assign_pointer(fnhe->fnhe_rth, rt);
1186 if (orig)
1187 rt_free(orig);
1188
1189 fnhe->fnhe_stamp = jiffies;
1190 ret = true;
1191 }
1192 spin_unlock_bh(&fnhe_lock);
1193
1194 return ret;
1195 }
1196
1197 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1198 {
1199 struct rtable *orig, *prev, **p;
1200 bool ret = true;
1201
1202 if (rt_is_input_route(rt)) {
1203 p = (struct rtable **)&nh->nh_rth_input;
1204 } else {
1205 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1206 }
1207 orig = *p;
1208
1209 prev = cmpxchg(p, orig, rt);
1210 if (prev == orig) {
1211 if (orig)
1212 rt_free(orig);
1213 } else
1214 ret = false;
1215
1216 return ret;
1217 }
1218
1219 static DEFINE_SPINLOCK(rt_uncached_lock);
1220 static LIST_HEAD(rt_uncached_list);
1221
1222 static void rt_add_uncached_list(struct rtable *rt)
1223 {
1224 spin_lock_bh(&rt_uncached_lock);
1225 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1226 spin_unlock_bh(&rt_uncached_lock);
1227 }
1228
1229 static void ipv4_dst_destroy(struct dst_entry *dst)
1230 {
1231 struct rtable *rt = (struct rtable *) dst;
1232
1233 if (!list_empty(&rt->rt_uncached)) {
1234 spin_lock_bh(&rt_uncached_lock);
1235 list_del(&rt->rt_uncached);
1236 spin_unlock_bh(&rt_uncached_lock);
1237 }
1238 }
1239
1240 void rt_flush_dev(struct net_device *dev)
1241 {
1242 if (!list_empty(&rt_uncached_list)) {
1243 struct net *net = dev_net(dev);
1244 struct rtable *rt;
1245
1246 spin_lock_bh(&rt_uncached_lock);
1247 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1248 if (rt->dst.dev != dev)
1249 continue;
1250 rt->dst.dev = net->loopback_dev;
1251 dev_hold(rt->dst.dev);
1252 dev_put(dev);
1253 }
1254 spin_unlock_bh(&rt_uncached_lock);
1255 }
1256 }
1257
1258 static bool rt_cache_valid(const struct rtable *rt)
1259 {
1260 return rt &&
1261 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1262 !rt_is_expired(rt);
1263 }
1264
1265 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1266 const struct fib_result *res,
1267 struct fib_nh_exception *fnhe,
1268 struct fib_info *fi, u16 type, u32 itag)
1269 {
1270 bool cached = false;
1271
1272 if (fi) {
1273 struct fib_nh *nh = &FIB_RES_NH(*res);
1274
1275 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1276 rt->rt_gateway = nh->nh_gw;
1277 rt->rt_uses_gateway = 1;
1278 }
1279 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1280 #ifdef CONFIG_IP_ROUTE_CLASSID
1281 rt->dst.tclassid = nh->nh_tclassid;
1282 #endif
1283 if (unlikely(fnhe))
1284 cached = rt_bind_exception(rt, fnhe, daddr);
1285 else if (!(rt->dst.flags & DST_NOCACHE))
1286 cached = rt_cache_route(nh, rt);
1287 if (unlikely(!cached)) {
1288 /* Routes we intend to cache in nexthop exception or
1289 * FIB nexthop have the DST_NOCACHE bit clear.
1290 * However, if we are unsuccessful at storing this
1291 * route into the cache we really need to set it.
1292 */
1293 rt->dst.flags |= DST_NOCACHE;
1294 if (!rt->rt_gateway)
1295 rt->rt_gateway = daddr;
1296 rt_add_uncached_list(rt);
1297 }
1298 } else
1299 rt_add_uncached_list(rt);
1300
1301 #ifdef CONFIG_IP_ROUTE_CLASSID
1302 #ifdef CONFIG_IP_MULTIPLE_TABLES
1303 set_class_tag(rt, res->tclassid);
1304 #endif
1305 set_class_tag(rt, itag);
1306 #endif
1307 }
1308
1309 static struct rtable *rt_dst_alloc(struct net_device *dev,
1310 bool nopolicy, bool noxfrm, bool will_cache)
1311 {
1312 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1313 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1314 (nopolicy ? DST_NOPOLICY : 0) |
1315 (noxfrm ? DST_NOXFRM : 0));
1316 }
1317
1318 /* called in rcu_read_lock() section */
1319 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1320 u8 tos, struct net_device *dev, int our)
1321 {
1322 struct rtable *rth;
1323 struct in_device *in_dev = __in_dev_get_rcu(dev);
1324 u32 itag = 0;
1325 int err;
1326
1327 /* Primary sanity checks. */
1328
1329 if (in_dev == NULL)
1330 return -EINVAL;
1331
1332 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1333 skb->protocol != htons(ETH_P_IP))
1334 goto e_inval;
1335
1336 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1337 if (ipv4_is_loopback(saddr))
1338 goto e_inval;
1339
1340 if (ipv4_is_zeronet(saddr)) {
1341 if (!ipv4_is_local_multicast(daddr))
1342 goto e_inval;
1343 } else {
1344 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1345 in_dev, &itag);
1346 if (err < 0)
1347 goto e_err;
1348 }
1349 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1350 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1351 if (!rth)
1352 goto e_nobufs;
1353
1354 #ifdef CONFIG_IP_ROUTE_CLASSID
1355 rth->dst.tclassid = itag;
1356 #endif
1357 rth->dst.output = ip_rt_bug;
1358
1359 rth->rt_genid = rt_genid(dev_net(dev));
1360 rth->rt_flags = RTCF_MULTICAST;
1361 rth->rt_type = RTN_MULTICAST;
1362 rth->rt_is_input= 1;
1363 rth->rt_iif = 0;
1364 rth->rt_pmtu = 0;
1365 rth->rt_gateway = 0;
1366 rth->rt_uses_gateway = 0;
1367 INIT_LIST_HEAD(&rth->rt_uncached);
1368 if (our) {
1369 rth->dst.input= ip_local_deliver;
1370 rth->rt_flags |= RTCF_LOCAL;
1371 }
1372
1373 #ifdef CONFIG_IP_MROUTE
1374 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1375 rth->dst.input = ip_mr_input;
1376 #endif
1377 RT_CACHE_STAT_INC(in_slow_mc);
1378
1379 skb_dst_set(skb, &rth->dst);
1380 return 0;
1381
1382 e_nobufs:
1383 return -ENOBUFS;
1384 e_inval:
1385 return -EINVAL;
1386 e_err:
1387 return err;
1388 }
1389
1390
1391 static void ip_handle_martian_source(struct net_device *dev,
1392 struct in_device *in_dev,
1393 struct sk_buff *skb,
1394 __be32 daddr,
1395 __be32 saddr)
1396 {
1397 RT_CACHE_STAT_INC(in_martian_src);
1398 #ifdef CONFIG_IP_ROUTE_VERBOSE
1399 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1400 /*
1401 * RFC1812 recommendation, if source is martian,
1402 * the only hint is MAC header.
1403 */
1404 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1405 &daddr, &saddr, dev->name);
1406 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1407 print_hex_dump(KERN_WARNING, "ll header: ",
1408 DUMP_PREFIX_OFFSET, 16, 1,
1409 skb_mac_header(skb),
1410 dev->hard_header_len, true);
1411 }
1412 }
1413 #endif
1414 }
1415
1416 /* called in rcu_read_lock() section */
1417 static int __mkroute_input(struct sk_buff *skb,
1418 const struct fib_result *res,
1419 struct in_device *in_dev,
1420 __be32 daddr, __be32 saddr, u32 tos)
1421 {
1422 struct rtable *rth;
1423 int err;
1424 struct in_device *out_dev;
1425 unsigned int flags = 0;
1426 bool do_cache;
1427 u32 itag;
1428
1429 /* get a working reference to the output device */
1430 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1431 if (out_dev == NULL) {
1432 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1433 return -EINVAL;
1434 }
1435
1436 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1437 in_dev->dev, in_dev, &itag);
1438 if (err < 0) {
1439 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1440 saddr);
1441
1442 goto cleanup;
1443 }
1444
1445 do_cache = res->fi && !itag;
1446 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1447 (IN_DEV_SHARED_MEDIA(out_dev) ||
1448 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) {
1449 flags |= RTCF_DOREDIRECT;
1450 do_cache = false;
1451 }
1452
1453 if (skb->protocol != htons(ETH_P_IP)) {
1454 /* Not IP (i.e. ARP). Do not create route, if it is
1455 * invalid for proxy arp. DNAT routes are always valid.
1456 *
1457 * Proxy arp feature have been extended to allow, ARP
1458 * replies back to the same interface, to support
1459 * Private VLAN switch technologies. See arp.c.
1460 */
1461 if (out_dev == in_dev &&
1462 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1463 err = -EINVAL;
1464 goto cleanup;
1465 }
1466 }
1467
1468 if (do_cache) {
1469 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1470 if (rt_cache_valid(rth)) {
1471 skb_dst_set_noref(skb, &rth->dst);
1472 goto out;
1473 }
1474 }
1475
1476 rth = rt_dst_alloc(out_dev->dev,
1477 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1478 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1479 if (!rth) {
1480 err = -ENOBUFS;
1481 goto cleanup;
1482 }
1483
1484 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
1485 rth->rt_flags = flags;
1486 rth->rt_type = res->type;
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
1494 rth->dst.input = ip_forward;
1495 rth->dst.output = ip_output;
1496
1497 rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag);
1498 skb_dst_set(skb, &rth->dst);
1499 out:
1500 err = 0;
1501 cleanup:
1502 return err;
1503 }
1504
1505 static int ip_mkroute_input(struct sk_buff *skb,
1506 struct fib_result *res,
1507 const struct flowi4 *fl4,
1508 struct in_device *in_dev,
1509 __be32 daddr, __be32 saddr, u32 tos)
1510 {
1511 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1512 if (res->fi && res->fi->fib_nhs > 1)
1513 fib_select_multipath(res);
1514 #endif
1515
1516 /* create a routing cache entry */
1517 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1518 }
1519
1520 /*
1521 * NOTE. We drop all the packets that has local source
1522 * addresses, because every properly looped back packet
1523 * must have correct destination already attached by output routine.
1524 *
1525 * Such approach solves two big problems:
1526 * 1. Not simplex devices are handled properly.
1527 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1528 * called with rcu_read_lock()
1529 */
1530
1531 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1532 u8 tos, struct net_device *dev)
1533 {
1534 struct fib_result res;
1535 struct in_device *in_dev = __in_dev_get_rcu(dev);
1536 struct flowi4 fl4;
1537 unsigned int flags = 0;
1538 u32 itag = 0;
1539 struct rtable *rth;
1540 int err = -EINVAL;
1541 struct net *net = dev_net(dev);
1542 bool do_cache;
1543
1544 /* IP on this device is disabled. */
1545
1546 if (!in_dev)
1547 goto out;
1548
1549 /* Check for the most weird martians, which can be not detected
1550 by fib_lookup.
1551 */
1552
1553 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1554 goto martian_source;
1555
1556 res.fi = NULL;
1557 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1558 goto brd_input;
1559
1560 /* Accept zero addresses only to limited broadcast;
1561 * I even do not know to fix it or not. Waiting for complains :-)
1562 */
1563 if (ipv4_is_zeronet(saddr))
1564 goto martian_source;
1565
1566 if (ipv4_is_zeronet(daddr))
1567 goto martian_destination;
1568
1569 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1570 * and call it once if daddr or/and saddr are loopback addresses
1571 */
1572 if (ipv4_is_loopback(daddr)) {
1573 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1574 goto martian_destination;
1575 } else if (ipv4_is_loopback(saddr)) {
1576 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1577 goto martian_source;
1578 }
1579
1580 /*
1581 * Now we are ready to route packet.
1582 */
1583 fl4.flowi4_oif = 0;
1584 fl4.flowi4_iif = dev->ifindex;
1585 fl4.flowi4_mark = skb->mark;
1586 fl4.flowi4_tos = tos;
1587 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1588 fl4.daddr = daddr;
1589 fl4.saddr = saddr;
1590 err = fib_lookup(net, &fl4, &res);
1591 if (err != 0)
1592 goto no_route;
1593
1594 RT_CACHE_STAT_INC(in_slow_tot);
1595
1596 if (res.type == RTN_BROADCAST)
1597 goto brd_input;
1598
1599 if (res.type == RTN_LOCAL) {
1600 err = fib_validate_source(skb, saddr, daddr, tos,
1601 LOOPBACK_IFINDEX,
1602 dev, in_dev, &itag);
1603 if (err < 0)
1604 goto martian_source_keep_err;
1605 goto local_input;
1606 }
1607
1608 if (!IN_DEV_FORWARD(in_dev))
1609 goto no_route;
1610 if (res.type != RTN_UNICAST)
1611 goto martian_destination;
1612
1613 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1614 out: return err;
1615
1616 brd_input:
1617 if (skb->protocol != htons(ETH_P_IP))
1618 goto e_inval;
1619
1620 if (!ipv4_is_zeronet(saddr)) {
1621 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1622 in_dev, &itag);
1623 if (err < 0)
1624 goto martian_source_keep_err;
1625 }
1626 flags |= RTCF_BROADCAST;
1627 res.type = RTN_BROADCAST;
1628 RT_CACHE_STAT_INC(in_brd);
1629
1630 local_input:
1631 do_cache = false;
1632 if (res.fi) {
1633 if (!itag) {
1634 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1635 if (rt_cache_valid(rth)) {
1636 skb_dst_set_noref(skb, &rth->dst);
1637 err = 0;
1638 goto out;
1639 }
1640 do_cache = true;
1641 }
1642 }
1643
1644 rth = rt_dst_alloc(net->loopback_dev,
1645 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1646 if (!rth)
1647 goto e_nobufs;
1648
1649 rth->dst.input= ip_local_deliver;
1650 rth->dst.output= ip_rt_bug;
1651 #ifdef CONFIG_IP_ROUTE_CLASSID
1652 rth->dst.tclassid = itag;
1653 #endif
1654
1655 rth->rt_genid = rt_genid(net);
1656 rth->rt_flags = flags|RTCF_LOCAL;
1657 rth->rt_type = res.type;
1658 rth->rt_is_input = 1;
1659 rth->rt_iif = 0;
1660 rth->rt_pmtu = 0;
1661 rth->rt_gateway = 0;
1662 rth->rt_uses_gateway = 0;
1663 INIT_LIST_HEAD(&rth->rt_uncached);
1664 if (res.type == RTN_UNREACHABLE) {
1665 rth->dst.input= ip_error;
1666 rth->dst.error= -err;
1667 rth->rt_flags &= ~RTCF_LOCAL;
1668 }
1669 if (do_cache)
1670 rt_cache_route(&FIB_RES_NH(res), rth);
1671 skb_dst_set(skb, &rth->dst);
1672 err = 0;
1673 goto out;
1674
1675 no_route:
1676 RT_CACHE_STAT_INC(in_no_route);
1677 res.type = RTN_UNREACHABLE;
1678 if (err == -ESRCH)
1679 err = -ENETUNREACH;
1680 goto local_input;
1681
1682 /*
1683 * Do not cache martian addresses: they should be logged (RFC1812)
1684 */
1685 martian_destination:
1686 RT_CACHE_STAT_INC(in_martian_dst);
1687 #ifdef CONFIG_IP_ROUTE_VERBOSE
1688 if (IN_DEV_LOG_MARTIANS(in_dev))
1689 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1690 &daddr, &saddr, dev->name);
1691 #endif
1692
1693 e_inval:
1694 err = -EINVAL;
1695 goto out;
1696
1697 e_nobufs:
1698 err = -ENOBUFS;
1699 goto out;
1700
1701 martian_source:
1702 err = -EINVAL;
1703 martian_source_keep_err:
1704 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1705 goto out;
1706 }
1707
1708 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1709 u8 tos, struct net_device *dev)
1710 {
1711 int res;
1712
1713 rcu_read_lock();
1714
1715 /* Multicast recognition logic is moved from route cache to here.
1716 The problem was that too many Ethernet cards have broken/missing
1717 hardware multicast filters :-( As result the host on multicasting
1718 network acquires a lot of useless route cache entries, sort of
1719 SDR messages from all the world. Now we try to get rid of them.
1720 Really, provided software IP multicast filter is organized
1721 reasonably (at least, hashed), it does not result in a slowdown
1722 comparing with route cache reject entries.
1723 Note, that multicast routers are not affected, because
1724 route cache entry is created eventually.
1725 */
1726 if (ipv4_is_multicast(daddr)) {
1727 struct in_device *in_dev = __in_dev_get_rcu(dev);
1728
1729 if (in_dev) {
1730 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1731 ip_hdr(skb)->protocol);
1732 if (our
1733 #ifdef CONFIG_IP_MROUTE
1734 ||
1735 (!ipv4_is_local_multicast(daddr) &&
1736 IN_DEV_MFORWARD(in_dev))
1737 #endif
1738 ) {
1739 int res = ip_route_input_mc(skb, daddr, saddr,
1740 tos, dev, our);
1741 rcu_read_unlock();
1742 return res;
1743 }
1744 }
1745 rcu_read_unlock();
1746 return -EINVAL;
1747 }
1748 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1749 rcu_read_unlock();
1750 return res;
1751 }
1752 EXPORT_SYMBOL(ip_route_input_noref);
1753
1754 /* called with rcu_read_lock() */
1755 static struct rtable *__mkroute_output(const struct fib_result *res,
1756 const struct flowi4 *fl4, int orig_oif,
1757 struct net_device *dev_out,
1758 unsigned int flags)
1759 {
1760 struct fib_info *fi = res->fi;
1761 struct fib_nh_exception *fnhe;
1762 struct in_device *in_dev;
1763 u16 type = res->type;
1764 struct rtable *rth;
1765 bool do_cache;
1766
1767 in_dev = __in_dev_get_rcu(dev_out);
1768 if (!in_dev)
1769 return ERR_PTR(-EINVAL);
1770
1771 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1772 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1773 return ERR_PTR(-EINVAL);
1774
1775 if (ipv4_is_lbcast(fl4->daddr))
1776 type = RTN_BROADCAST;
1777 else if (ipv4_is_multicast(fl4->daddr))
1778 type = RTN_MULTICAST;
1779 else if (ipv4_is_zeronet(fl4->daddr))
1780 return ERR_PTR(-EINVAL);
1781
1782 if (dev_out->flags & IFF_LOOPBACK)
1783 flags |= RTCF_LOCAL;
1784
1785 if (type == RTN_BROADCAST) {
1786 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1787 fi = NULL;
1788 } else if (type == RTN_MULTICAST) {
1789 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1790 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1791 fl4->flowi4_proto))
1792 flags &= ~RTCF_LOCAL;
1793 /* If multicast route do not exist use
1794 * default one, but do not gateway in this case.
1795 * Yes, it is hack.
1796 */
1797 if (fi && res->prefixlen < 4)
1798 fi = NULL;
1799 }
1800
1801 fnhe = NULL;
1802 do_cache = fi != NULL;
1803 if (fi) {
1804 struct rtable __rcu **prth;
1805 struct fib_nh *nh = &FIB_RES_NH(*res);
1806
1807 fnhe = find_exception(nh, fl4->daddr);
1808 if (fnhe)
1809 prth = &fnhe->fnhe_rth;
1810 else {
1811 if (unlikely(fl4->flowi4_flags &
1812 FLOWI_FLAG_KNOWN_NH &&
1813 !(nh->nh_gw &&
1814 nh->nh_scope == RT_SCOPE_LINK))) {
1815 do_cache = false;
1816 goto add;
1817 }
1818 prth = __this_cpu_ptr(nh->nh_pcpu_rth_output);
1819 }
1820 rth = rcu_dereference(*prth);
1821 if (rt_cache_valid(rth)) {
1822 dst_hold(&rth->dst);
1823 return rth;
1824 }
1825 }
1826
1827 add:
1828 rth = rt_dst_alloc(dev_out,
1829 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1830 IN_DEV_CONF_GET(in_dev, NOXFRM),
1831 do_cache);
1832 if (!rth)
1833 return ERR_PTR(-ENOBUFS);
1834
1835 rth->dst.output = ip_output;
1836
1837 rth->rt_genid = rt_genid(dev_net(dev_out));
1838 rth->rt_flags = flags;
1839 rth->rt_type = type;
1840 rth->rt_is_input = 0;
1841 rth->rt_iif = orig_oif ? : 0;
1842 rth->rt_pmtu = 0;
1843 rth->rt_gateway = 0;
1844 rth->rt_uses_gateway = 0;
1845 INIT_LIST_HEAD(&rth->rt_uncached);
1846
1847 RT_CACHE_STAT_INC(out_slow_tot);
1848
1849 if (flags & RTCF_LOCAL)
1850 rth->dst.input = ip_local_deliver;
1851 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1852 if (flags & RTCF_LOCAL &&
1853 !(dev_out->flags & IFF_LOOPBACK)) {
1854 rth->dst.output = ip_mc_output;
1855 RT_CACHE_STAT_INC(out_slow_mc);
1856 }
1857 #ifdef CONFIG_IP_MROUTE
1858 if (type == RTN_MULTICAST) {
1859 if (IN_DEV_MFORWARD(in_dev) &&
1860 !ipv4_is_local_multicast(fl4->daddr)) {
1861 rth->dst.input = ip_mr_input;
1862 rth->dst.output = ip_mc_output;
1863 }
1864 }
1865 #endif
1866 }
1867
1868 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1869
1870 return rth;
1871 }
1872
1873 /*
1874 * Major route resolver routine.
1875 */
1876
1877 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1878 {
1879 struct net_device *dev_out = NULL;
1880 __u8 tos = RT_FL_TOS(fl4);
1881 unsigned int flags = 0;
1882 struct fib_result res;
1883 struct rtable *rth;
1884 int orig_oif;
1885
1886 res.tclassid = 0;
1887 res.fi = NULL;
1888 res.table = NULL;
1889
1890 orig_oif = fl4->flowi4_oif;
1891
1892 fl4->flowi4_iif = LOOPBACK_IFINDEX;
1893 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
1894 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
1895 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
1896
1897 rcu_read_lock();
1898 if (fl4->saddr) {
1899 rth = ERR_PTR(-EINVAL);
1900 if (ipv4_is_multicast(fl4->saddr) ||
1901 ipv4_is_lbcast(fl4->saddr) ||
1902 ipv4_is_zeronet(fl4->saddr))
1903 goto out;
1904
1905 /* I removed check for oif == dev_out->oif here.
1906 It was wrong for two reasons:
1907 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
1908 is assigned to multiple interfaces.
1909 2. Moreover, we are allowed to send packets with saddr
1910 of another iface. --ANK
1911 */
1912
1913 if (fl4->flowi4_oif == 0 &&
1914 (ipv4_is_multicast(fl4->daddr) ||
1915 ipv4_is_lbcast(fl4->daddr))) {
1916 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1917 dev_out = __ip_dev_find(net, fl4->saddr, false);
1918 if (dev_out == NULL)
1919 goto out;
1920
1921 /* Special hack: user can direct multicasts
1922 and limited broadcast via necessary interface
1923 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
1924 This hack is not just for fun, it allows
1925 vic,vat and friends to work.
1926 They bind socket to loopback, set ttl to zero
1927 and expect that it will work.
1928 From the viewpoint of routing cache they are broken,
1929 because we are not allowed to build multicast path
1930 with loopback source addr (look, routing cache
1931 cannot know, that ttl is zero, so that packet
1932 will not leave this host and route is valid).
1933 Luckily, this hack is good workaround.
1934 */
1935
1936 fl4->flowi4_oif = dev_out->ifindex;
1937 goto make_route;
1938 }
1939
1940 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
1941 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1942 if (!__ip_dev_find(net, fl4->saddr, false))
1943 goto out;
1944 }
1945 }
1946
1947
1948 if (fl4->flowi4_oif) {
1949 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
1950 rth = ERR_PTR(-ENODEV);
1951 if (dev_out == NULL)
1952 goto out;
1953
1954 /* RACE: Check return value of inet_select_addr instead. */
1955 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
1956 rth = ERR_PTR(-ENETUNREACH);
1957 goto out;
1958 }
1959 if (ipv4_is_local_multicast(fl4->daddr) ||
1960 ipv4_is_lbcast(fl4->daddr)) {
1961 if (!fl4->saddr)
1962 fl4->saddr = inet_select_addr(dev_out, 0,
1963 RT_SCOPE_LINK);
1964 goto make_route;
1965 }
1966 if (fl4->saddr) {
1967 if (ipv4_is_multicast(fl4->daddr))
1968 fl4->saddr = inet_select_addr(dev_out, 0,
1969 fl4->flowi4_scope);
1970 else if (!fl4->daddr)
1971 fl4->saddr = inet_select_addr(dev_out, 0,
1972 RT_SCOPE_HOST);
1973 }
1974 }
1975
1976 if (!fl4->daddr) {
1977 fl4->daddr = fl4->saddr;
1978 if (!fl4->daddr)
1979 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
1980 dev_out = net->loopback_dev;
1981 fl4->flowi4_oif = LOOPBACK_IFINDEX;
1982 res.type = RTN_LOCAL;
1983 flags |= RTCF_LOCAL;
1984 goto make_route;
1985 }
1986
1987 if (fib_lookup(net, fl4, &res)) {
1988 res.fi = NULL;
1989 res.table = NULL;
1990 if (fl4->flowi4_oif) {
1991 /* Apparently, routing tables are wrong. Assume,
1992 that the destination is on link.
1993
1994 WHY? DW.
1995 Because we are allowed to send to iface
1996 even if it has NO routes and NO assigned
1997 addresses. When oif is specified, routing
1998 tables are looked up with only one purpose:
1999 to catch if destination is gatewayed, rather than
2000 direct. Moreover, if MSG_DONTROUTE is set,
2001 we send packet, ignoring both routing tables
2002 and ifaddr state. --ANK
2003
2004
2005 We could make it even if oif is unknown,
2006 likely IPv6, but we do not.
2007 */
2008
2009 if (fl4->saddr == 0)
2010 fl4->saddr = inet_select_addr(dev_out, 0,
2011 RT_SCOPE_LINK);
2012 res.type = RTN_UNICAST;
2013 goto make_route;
2014 }
2015 rth = ERR_PTR(-ENETUNREACH);
2016 goto out;
2017 }
2018
2019 if (res.type == RTN_LOCAL) {
2020 if (!fl4->saddr) {
2021 if (res.fi->fib_prefsrc)
2022 fl4->saddr = res.fi->fib_prefsrc;
2023 else
2024 fl4->saddr = fl4->daddr;
2025 }
2026 dev_out = net->loopback_dev;
2027 fl4->flowi4_oif = dev_out->ifindex;
2028 flags |= RTCF_LOCAL;
2029 goto make_route;
2030 }
2031
2032 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2033 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2034 fib_select_multipath(&res);
2035 else
2036 #endif
2037 if (!res.prefixlen &&
2038 res.table->tb_num_default > 1 &&
2039 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2040 fib_select_default(&res);
2041
2042 if (!fl4->saddr)
2043 fl4->saddr = FIB_RES_PREFSRC(net, res);
2044
2045 dev_out = FIB_RES_DEV(res);
2046 fl4->flowi4_oif = dev_out->ifindex;
2047
2048
2049 make_route:
2050 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2051
2052 out:
2053 rcu_read_unlock();
2054 return rth;
2055 }
2056 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2057
2058 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2059 {
2060 return NULL;
2061 }
2062
2063 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2064 {
2065 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2066
2067 return mtu ? : dst->dev->mtu;
2068 }
2069
2070 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2071 struct sk_buff *skb, u32 mtu)
2072 {
2073 }
2074
2075 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2076 struct sk_buff *skb)
2077 {
2078 }
2079
2080 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2081 unsigned long old)
2082 {
2083 return NULL;
2084 }
2085
2086 static struct dst_ops ipv4_dst_blackhole_ops = {
2087 .family = AF_INET,
2088 .protocol = cpu_to_be16(ETH_P_IP),
2089 .check = ipv4_blackhole_dst_check,
2090 .mtu = ipv4_blackhole_mtu,
2091 .default_advmss = ipv4_default_advmss,
2092 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2093 .redirect = ipv4_rt_blackhole_redirect,
2094 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2095 .neigh_lookup = ipv4_neigh_lookup,
2096 };
2097
2098 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2099 {
2100 struct rtable *ort = (struct rtable *) dst_orig;
2101 struct rtable *rt;
2102
2103 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2104 if (rt) {
2105 struct dst_entry *new = &rt->dst;
2106
2107 new->__use = 1;
2108 new->input = dst_discard;
2109 new->output = dst_discard;
2110
2111 new->dev = ort->dst.dev;
2112 if (new->dev)
2113 dev_hold(new->dev);
2114
2115 rt->rt_is_input = ort->rt_is_input;
2116 rt->rt_iif = ort->rt_iif;
2117 rt->rt_pmtu = ort->rt_pmtu;
2118
2119 rt->rt_genid = rt_genid(net);
2120 rt->rt_flags = ort->rt_flags;
2121 rt->rt_type = ort->rt_type;
2122 rt->rt_gateway = ort->rt_gateway;
2123 rt->rt_uses_gateway = ort->rt_uses_gateway;
2124
2125 INIT_LIST_HEAD(&rt->rt_uncached);
2126
2127 dst_free(new);
2128 }
2129
2130 dst_release(dst_orig);
2131
2132 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2133 }
2134
2135 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2136 struct sock *sk)
2137 {
2138 struct rtable *rt = __ip_route_output_key(net, flp4);
2139
2140 if (IS_ERR(rt))
2141 return rt;
2142
2143 if (flp4->flowi4_proto)
2144 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2145 flowi4_to_flowi(flp4),
2146 sk, 0);
2147
2148 return rt;
2149 }
2150 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2151
2152 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2153 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2154 u32 seq, int event, int nowait, unsigned int flags)
2155 {
2156 struct rtable *rt = skb_rtable(skb);
2157 struct rtmsg *r;
2158 struct nlmsghdr *nlh;
2159 unsigned long expires = 0;
2160 u32 error;
2161 u32 metrics[RTAX_MAX];
2162
2163 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2164 if (nlh == NULL)
2165 return -EMSGSIZE;
2166
2167 r = nlmsg_data(nlh);
2168 r->rtm_family = AF_INET;
2169 r->rtm_dst_len = 32;
2170 r->rtm_src_len = 0;
2171 r->rtm_tos = fl4->flowi4_tos;
2172 r->rtm_table = RT_TABLE_MAIN;
2173 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2174 goto nla_put_failure;
2175 r->rtm_type = rt->rt_type;
2176 r->rtm_scope = RT_SCOPE_UNIVERSE;
2177 r->rtm_protocol = RTPROT_UNSPEC;
2178 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2179 if (rt->rt_flags & RTCF_NOTIFY)
2180 r->rtm_flags |= RTM_F_NOTIFY;
2181
2182 if (nla_put_be32(skb, RTA_DST, dst))
2183 goto nla_put_failure;
2184 if (src) {
2185 r->rtm_src_len = 32;
2186 if (nla_put_be32(skb, RTA_SRC, src))
2187 goto nla_put_failure;
2188 }
2189 if (rt->dst.dev &&
2190 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2191 goto nla_put_failure;
2192 #ifdef CONFIG_IP_ROUTE_CLASSID
2193 if (rt->dst.tclassid &&
2194 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2195 goto nla_put_failure;
2196 #endif
2197 if (!rt_is_input_route(rt) &&
2198 fl4->saddr != src) {
2199 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2200 goto nla_put_failure;
2201 }
2202 if (rt->rt_uses_gateway &&
2203 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2204 goto nla_put_failure;
2205
2206 expires = rt->dst.expires;
2207 if (expires) {
2208 unsigned long now = jiffies;
2209
2210 if (time_before(now, expires))
2211 expires -= now;
2212 else
2213 expires = 0;
2214 }
2215
2216 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2217 if (rt->rt_pmtu && expires)
2218 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2219 if (rtnetlink_put_metrics(skb, metrics) < 0)
2220 goto nla_put_failure;
2221
2222 if (fl4->flowi4_mark &&
2223 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2224 goto nla_put_failure;
2225
2226 error = rt->dst.error;
2227
2228 if (rt_is_input_route(rt)) {
2229 if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
2230 goto nla_put_failure;
2231 }
2232
2233 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2234 goto nla_put_failure;
2235
2236 return nlmsg_end(skb, nlh);
2237
2238 nla_put_failure:
2239 nlmsg_cancel(skb, nlh);
2240 return -EMSGSIZE;
2241 }
2242
2243 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
2244 {
2245 struct net *net = sock_net(in_skb->sk);
2246 struct rtmsg *rtm;
2247 struct nlattr *tb[RTA_MAX+1];
2248 struct rtable *rt = NULL;
2249 struct flowi4 fl4;
2250 __be32 dst = 0;
2251 __be32 src = 0;
2252 u32 iif;
2253 int err;
2254 int mark;
2255 struct sk_buff *skb;
2256
2257 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2258 if (err < 0)
2259 goto errout;
2260
2261 rtm = nlmsg_data(nlh);
2262
2263 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2264 if (skb == NULL) {
2265 err = -ENOBUFS;
2266 goto errout;
2267 }
2268
2269 /* Reserve room for dummy headers, this skb can pass
2270 through good chunk of routing engine.
2271 */
2272 skb_reset_mac_header(skb);
2273 skb_reset_network_header(skb);
2274
2275 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2276 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2277 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2278
2279 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2280 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2281 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2282 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2283
2284 memset(&fl4, 0, sizeof(fl4));
2285 fl4.daddr = dst;
2286 fl4.saddr = src;
2287 fl4.flowi4_tos = rtm->rtm_tos;
2288 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2289 fl4.flowi4_mark = mark;
2290
2291 if (iif) {
2292 struct net_device *dev;
2293
2294 dev = __dev_get_by_index(net, iif);
2295 if (dev == NULL) {
2296 err = -ENODEV;
2297 goto errout_free;
2298 }
2299
2300 skb->protocol = htons(ETH_P_IP);
2301 skb->dev = dev;
2302 skb->mark = mark;
2303 local_bh_disable();
2304 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2305 local_bh_enable();
2306
2307 rt = skb_rtable(skb);
2308 if (err == 0 && rt->dst.error)
2309 err = -rt->dst.error;
2310 } else {
2311 rt = ip_route_output_key(net, &fl4);
2312
2313 err = 0;
2314 if (IS_ERR(rt))
2315 err = PTR_ERR(rt);
2316 }
2317
2318 if (err)
2319 goto errout_free;
2320
2321 skb_dst_set(skb, &rt->dst);
2322 if (rtm->rtm_flags & RTM_F_NOTIFY)
2323 rt->rt_flags |= RTCF_NOTIFY;
2324
2325 err = rt_fill_info(net, dst, src, &fl4, skb,
2326 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2327 RTM_NEWROUTE, 0, 0);
2328 if (err <= 0)
2329 goto errout_free;
2330
2331 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2332 errout:
2333 return err;
2334
2335 errout_free:
2336 kfree_skb(skb);
2337 goto errout;
2338 }
2339
2340 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2341 {
2342 return skb->len;
2343 }
2344
2345 void ip_rt_multicast_event(struct in_device *in_dev)
2346 {
2347 rt_cache_flush(dev_net(in_dev->dev));
2348 }
2349
2350 #ifdef CONFIG_SYSCTL
2351 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
2352 void __user *buffer,
2353 size_t *lenp, loff_t *ppos)
2354 {
2355 if (write) {
2356 rt_cache_flush((struct net *)__ctl->extra1);
2357 return 0;
2358 }
2359
2360 return -EINVAL;
2361 }
2362
2363 static ctl_table ipv4_route_table[] = {
2364 {
2365 .procname = "gc_thresh",
2366 .data = &ipv4_dst_ops.gc_thresh,
2367 .maxlen = sizeof(int),
2368 .mode = 0644,
2369 .proc_handler = proc_dointvec,
2370 },
2371 {
2372 .procname = "max_size",
2373 .data = &ip_rt_max_size,
2374 .maxlen = sizeof(int),
2375 .mode = 0644,
2376 .proc_handler = proc_dointvec,
2377 },
2378 {
2379 /* Deprecated. Use gc_min_interval_ms */
2380
2381 .procname = "gc_min_interval",
2382 .data = &ip_rt_gc_min_interval,
2383 .maxlen = sizeof(int),
2384 .mode = 0644,
2385 .proc_handler = proc_dointvec_jiffies,
2386 },
2387 {
2388 .procname = "gc_min_interval_ms",
2389 .data = &ip_rt_gc_min_interval,
2390 .maxlen = sizeof(int),
2391 .mode = 0644,
2392 .proc_handler = proc_dointvec_ms_jiffies,
2393 },
2394 {
2395 .procname = "gc_timeout",
2396 .data = &ip_rt_gc_timeout,
2397 .maxlen = sizeof(int),
2398 .mode = 0644,
2399 .proc_handler = proc_dointvec_jiffies,
2400 },
2401 {
2402 .procname = "gc_interval",
2403 .data = &ip_rt_gc_interval,
2404 .maxlen = sizeof(int),
2405 .mode = 0644,
2406 .proc_handler = proc_dointvec_jiffies,
2407 },
2408 {
2409 .procname = "redirect_load",
2410 .data = &ip_rt_redirect_load,
2411 .maxlen = sizeof(int),
2412 .mode = 0644,
2413 .proc_handler = proc_dointvec,
2414 },
2415 {
2416 .procname = "redirect_number",
2417 .data = &ip_rt_redirect_number,
2418 .maxlen = sizeof(int),
2419 .mode = 0644,
2420 .proc_handler = proc_dointvec,
2421 },
2422 {
2423 .procname = "redirect_silence",
2424 .data = &ip_rt_redirect_silence,
2425 .maxlen = sizeof(int),
2426 .mode = 0644,
2427 .proc_handler = proc_dointvec,
2428 },
2429 {
2430 .procname = "error_cost",
2431 .data = &ip_rt_error_cost,
2432 .maxlen = sizeof(int),
2433 .mode = 0644,
2434 .proc_handler = proc_dointvec,
2435 },
2436 {
2437 .procname = "error_burst",
2438 .data = &ip_rt_error_burst,
2439 .maxlen = sizeof(int),
2440 .mode = 0644,
2441 .proc_handler = proc_dointvec,
2442 },
2443 {
2444 .procname = "gc_elasticity",
2445 .data = &ip_rt_gc_elasticity,
2446 .maxlen = sizeof(int),
2447 .mode = 0644,
2448 .proc_handler = proc_dointvec,
2449 },
2450 {
2451 .procname = "mtu_expires",
2452 .data = &ip_rt_mtu_expires,
2453 .maxlen = sizeof(int),
2454 .mode = 0644,
2455 .proc_handler = proc_dointvec_jiffies,
2456 },
2457 {
2458 .procname = "min_pmtu",
2459 .data = &ip_rt_min_pmtu,
2460 .maxlen = sizeof(int),
2461 .mode = 0644,
2462 .proc_handler = proc_dointvec,
2463 },
2464 {
2465 .procname = "min_adv_mss",
2466 .data = &ip_rt_min_advmss,
2467 .maxlen = sizeof(int),
2468 .mode = 0644,
2469 .proc_handler = proc_dointvec,
2470 },
2471 { }
2472 };
2473
2474 static struct ctl_table ipv4_route_flush_table[] = {
2475 {
2476 .procname = "flush",
2477 .maxlen = sizeof(int),
2478 .mode = 0200,
2479 .proc_handler = ipv4_sysctl_rtcache_flush,
2480 },
2481 { },
2482 };
2483
2484 static __net_init int sysctl_route_net_init(struct net *net)
2485 {
2486 struct ctl_table *tbl;
2487
2488 tbl = ipv4_route_flush_table;
2489 if (!net_eq(net, &init_net)) {
2490 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2491 if (tbl == NULL)
2492 goto err_dup;
2493 }
2494 tbl[0].extra1 = net;
2495
2496 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2497 if (net->ipv4.route_hdr == NULL)
2498 goto err_reg;
2499 return 0;
2500
2501 err_reg:
2502 if (tbl != ipv4_route_flush_table)
2503 kfree(tbl);
2504 err_dup:
2505 return -ENOMEM;
2506 }
2507
2508 static __net_exit void sysctl_route_net_exit(struct net *net)
2509 {
2510 struct ctl_table *tbl;
2511
2512 tbl = net->ipv4.route_hdr->ctl_table_arg;
2513 unregister_net_sysctl_table(net->ipv4.route_hdr);
2514 BUG_ON(tbl == ipv4_route_flush_table);
2515 kfree(tbl);
2516 }
2517
2518 static __net_initdata struct pernet_operations sysctl_route_ops = {
2519 .init = sysctl_route_net_init,
2520 .exit = sysctl_route_net_exit,
2521 };
2522 #endif
2523
2524 static __net_init int rt_genid_init(struct net *net)
2525 {
2526 atomic_set(&net->rt_genid, 0);
2527 get_random_bytes(&net->ipv4.dev_addr_genid,
2528 sizeof(net->ipv4.dev_addr_genid));
2529 return 0;
2530 }
2531
2532 static __net_initdata struct pernet_operations rt_genid_ops = {
2533 .init = rt_genid_init,
2534 };
2535
2536 static int __net_init ipv4_inetpeer_init(struct net *net)
2537 {
2538 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2539
2540 if (!bp)
2541 return -ENOMEM;
2542 inet_peer_base_init(bp);
2543 net->ipv4.peers = bp;
2544 return 0;
2545 }
2546
2547 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2548 {
2549 struct inet_peer_base *bp = net->ipv4.peers;
2550
2551 net->ipv4.peers = NULL;
2552 inetpeer_invalidate_tree(bp);
2553 kfree(bp);
2554 }
2555
2556 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2557 .init = ipv4_inetpeer_init,
2558 .exit = ipv4_inetpeer_exit,
2559 };
2560
2561 #ifdef CONFIG_IP_ROUTE_CLASSID
2562 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2563 #endif /* CONFIG_IP_ROUTE_CLASSID */
2564
2565 int __init ip_rt_init(void)
2566 {
2567 int rc = 0;
2568
2569 #ifdef CONFIG_IP_ROUTE_CLASSID
2570 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2571 if (!ip_rt_acct)
2572 panic("IP: failed to allocate ip_rt_acct\n");
2573 #endif
2574
2575 ipv4_dst_ops.kmem_cachep =
2576 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2577 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2578
2579 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2580
2581 if (dst_entries_init(&ipv4_dst_ops) < 0)
2582 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2583
2584 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2585 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2586
2587 ipv4_dst_ops.gc_thresh = ~0;
2588 ip_rt_max_size = INT_MAX;
2589
2590 devinet_init();
2591 ip_fib_init();
2592
2593 if (ip_rt_proc_init())
2594 pr_err("Unable to create route proc files\n");
2595 #ifdef CONFIG_XFRM
2596 xfrm_init();
2597 xfrm4_init(ip_rt_max_size);
2598 #endif
2599 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2600
2601 #ifdef CONFIG_SYSCTL
2602 register_pernet_subsys(&sysctl_route_ops);
2603 #endif
2604 register_pernet_subsys(&rt_genid_ops);
2605 register_pernet_subsys(&ipv4_inetpeer_ops);
2606 return rc;
2607 }
2608
2609 #ifdef CONFIG_SYSCTL
2610 /*
2611 * We really need to sanitize the damn ipv4 init order, then all
2612 * this nonsense will go away.
2613 */
2614 void __init ip_static_sysctl_init(void)
2615 {
2616 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2617 }
2618 #endif
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