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Merge tag 'usb-3.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
[deliverable/linux.git] / net / ipv4 / route.c
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 static inline int rt_genid(struct net *net)
206 {
207 return atomic_read(&net->ipv4.rt_genid);
208 }
209
210 #ifdef CONFIG_PROC_FS
211 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
212 {
213 if (*pos)
214 return NULL;
215 return SEQ_START_TOKEN;
216 }
217
218 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
219 {
220 ++*pos;
221 return NULL;
222 }
223
224 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
225 {
226 }
227
228 static int rt_cache_seq_show(struct seq_file *seq, void *v)
229 {
230 if (v == SEQ_START_TOKEN)
231 seq_printf(seq, "%-127s\n",
232 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
233 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
234 "HHUptod\tSpecDst");
235 return 0;
236 }
237
238 static const struct seq_operations rt_cache_seq_ops = {
239 .start = rt_cache_seq_start,
240 .next = rt_cache_seq_next,
241 .stop = rt_cache_seq_stop,
242 .show = rt_cache_seq_show,
243 };
244
245 static int rt_cache_seq_open(struct inode *inode, struct file *file)
246 {
247 return seq_open(file, &rt_cache_seq_ops);
248 }
249
250 static const struct file_operations rt_cache_seq_fops = {
251 .owner = THIS_MODULE,
252 .open = rt_cache_seq_open,
253 .read = seq_read,
254 .llseek = seq_lseek,
255 .release = seq_release,
256 };
257
258
259 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
260 {
261 int cpu;
262
263 if (*pos == 0)
264 return SEQ_START_TOKEN;
265
266 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
267 if (!cpu_possible(cpu))
268 continue;
269 *pos = cpu+1;
270 return &per_cpu(rt_cache_stat, cpu);
271 }
272 return NULL;
273 }
274
275 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
276 {
277 int cpu;
278
279 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
280 if (!cpu_possible(cpu))
281 continue;
282 *pos = cpu+1;
283 return &per_cpu(rt_cache_stat, cpu);
284 }
285 return NULL;
286
287 }
288
289 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
290 {
291
292 }
293
294 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
295 {
296 struct rt_cache_stat *st = v;
297
298 if (v == SEQ_START_TOKEN) {
299 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");
300 return 0;
301 }
302
303 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
304 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
305 dst_entries_get_slow(&ipv4_dst_ops),
306 st->in_hit,
307 st->in_slow_tot,
308 st->in_slow_mc,
309 st->in_no_route,
310 st->in_brd,
311 st->in_martian_dst,
312 st->in_martian_src,
313
314 st->out_hit,
315 st->out_slow_tot,
316 st->out_slow_mc,
317
318 st->gc_total,
319 st->gc_ignored,
320 st->gc_goal_miss,
321 st->gc_dst_overflow,
322 st->in_hlist_search,
323 st->out_hlist_search
324 );
325 return 0;
326 }
327
328 static const struct seq_operations rt_cpu_seq_ops = {
329 .start = rt_cpu_seq_start,
330 .next = rt_cpu_seq_next,
331 .stop = rt_cpu_seq_stop,
332 .show = rt_cpu_seq_show,
333 };
334
335
336 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
337 {
338 return seq_open(file, &rt_cpu_seq_ops);
339 }
340
341 static const struct file_operations rt_cpu_seq_fops = {
342 .owner = THIS_MODULE,
343 .open = rt_cpu_seq_open,
344 .read = seq_read,
345 .llseek = seq_lseek,
346 .release = seq_release,
347 };
348
349 #ifdef CONFIG_IP_ROUTE_CLASSID
350 static int rt_acct_proc_show(struct seq_file *m, void *v)
351 {
352 struct ip_rt_acct *dst, *src;
353 unsigned int i, j;
354
355 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
356 if (!dst)
357 return -ENOMEM;
358
359 for_each_possible_cpu(i) {
360 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
361 for (j = 0; j < 256; j++) {
362 dst[j].o_bytes += src[j].o_bytes;
363 dst[j].o_packets += src[j].o_packets;
364 dst[j].i_bytes += src[j].i_bytes;
365 dst[j].i_packets += src[j].i_packets;
366 }
367 }
368
369 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
370 kfree(dst);
371 return 0;
372 }
373
374 static int rt_acct_proc_open(struct inode *inode, struct file *file)
375 {
376 return single_open(file, rt_acct_proc_show, NULL);
377 }
378
379 static const struct file_operations rt_acct_proc_fops = {
380 .owner = THIS_MODULE,
381 .open = rt_acct_proc_open,
382 .read = seq_read,
383 .llseek = seq_lseek,
384 .release = single_release,
385 };
386 #endif
387
388 static int __net_init ip_rt_do_proc_init(struct net *net)
389 {
390 struct proc_dir_entry *pde;
391
392 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
393 &rt_cache_seq_fops);
394 if (!pde)
395 goto err1;
396
397 pde = proc_create("rt_cache", S_IRUGO,
398 net->proc_net_stat, &rt_cpu_seq_fops);
399 if (!pde)
400 goto err2;
401
402 #ifdef CONFIG_IP_ROUTE_CLASSID
403 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
404 if (!pde)
405 goto err3;
406 #endif
407 return 0;
408
409 #ifdef CONFIG_IP_ROUTE_CLASSID
410 err3:
411 remove_proc_entry("rt_cache", net->proc_net_stat);
412 #endif
413 err2:
414 remove_proc_entry("rt_cache", net->proc_net);
415 err1:
416 return -ENOMEM;
417 }
418
419 static void __net_exit ip_rt_do_proc_exit(struct net *net)
420 {
421 remove_proc_entry("rt_cache", net->proc_net_stat);
422 remove_proc_entry("rt_cache", net->proc_net);
423 #ifdef CONFIG_IP_ROUTE_CLASSID
424 remove_proc_entry("rt_acct", net->proc_net);
425 #endif
426 }
427
428 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
429 .init = ip_rt_do_proc_init,
430 .exit = ip_rt_do_proc_exit,
431 };
432
433 static int __init ip_rt_proc_init(void)
434 {
435 return register_pernet_subsys(&ip_rt_proc_ops);
436 }
437
438 #else
439 static inline int ip_rt_proc_init(void)
440 {
441 return 0;
442 }
443 #endif /* CONFIG_PROC_FS */
444
445 static inline bool rt_is_expired(const struct rtable *rth)
446 {
447 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
448 }
449
450 /*
451 * Perturbation of rt_genid by a small quantity [1..256]
452 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
453 * many times (2^24) without giving recent rt_genid.
454 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
455 */
456 static void rt_cache_invalidate(struct net *net)
457 {
458 unsigned char shuffle;
459
460 get_random_bytes(&shuffle, sizeof(shuffle));
461 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
462 }
463
464 /*
465 * delay < 0 : invalidate cache (fast : entries will be deleted later)
466 * delay >= 0 : invalidate & flush cache (can be long)
467 */
468 void rt_cache_flush(struct net *net, int delay)
469 {
470 rt_cache_invalidate(net);
471 }
472
473 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
474 struct sk_buff *skb,
475 const void *daddr)
476 {
477 struct net_device *dev = dst->dev;
478 const __be32 *pkey = daddr;
479 const struct rtable *rt;
480 struct neighbour *n;
481
482 rt = (const struct rtable *) dst;
483 if (rt->rt_gateway)
484 pkey = (const __be32 *) &rt->rt_gateway;
485 else if (skb)
486 pkey = &ip_hdr(skb)->daddr;
487
488 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
489 if (n)
490 return n;
491 return neigh_create(&arp_tbl, pkey, dev);
492 }
493
494 /*
495 * Peer allocation may fail only in serious out-of-memory conditions. However
496 * we still can generate some output.
497 * Random ID selection looks a bit dangerous because we have no chances to
498 * select ID being unique in a reasonable period of time.
499 * But broken packet identifier may be better than no packet at all.
500 */
501 static void ip_select_fb_ident(struct iphdr *iph)
502 {
503 static DEFINE_SPINLOCK(ip_fb_id_lock);
504 static u32 ip_fallback_id;
505 u32 salt;
506
507 spin_lock_bh(&ip_fb_id_lock);
508 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
509 iph->id = htons(salt & 0xFFFF);
510 ip_fallback_id = salt;
511 spin_unlock_bh(&ip_fb_id_lock);
512 }
513
514 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
515 {
516 struct net *net = dev_net(dst->dev);
517 struct inet_peer *peer;
518
519 peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1);
520 if (peer) {
521 iph->id = htons(inet_getid(peer, more));
522 inet_putpeer(peer);
523 return;
524 }
525
526 ip_select_fb_ident(iph);
527 }
528 EXPORT_SYMBOL(__ip_select_ident);
529
530 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
531 const struct iphdr *iph,
532 int oif, u8 tos,
533 u8 prot, u32 mark, int flow_flags)
534 {
535 if (sk) {
536 const struct inet_sock *inet = inet_sk(sk);
537
538 oif = sk->sk_bound_dev_if;
539 mark = sk->sk_mark;
540 tos = RT_CONN_FLAGS(sk);
541 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
542 }
543 flowi4_init_output(fl4, oif, mark, tos,
544 RT_SCOPE_UNIVERSE, prot,
545 flow_flags,
546 iph->daddr, iph->saddr, 0, 0);
547 }
548
549 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
550 const struct sock *sk)
551 {
552 const struct iphdr *iph = ip_hdr(skb);
553 int oif = skb->dev->ifindex;
554 u8 tos = RT_TOS(iph->tos);
555 u8 prot = iph->protocol;
556 u32 mark = skb->mark;
557
558 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
559 }
560
561 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
562 {
563 const struct inet_sock *inet = inet_sk(sk);
564 const struct ip_options_rcu *inet_opt;
565 __be32 daddr = inet->inet_daddr;
566
567 rcu_read_lock();
568 inet_opt = rcu_dereference(inet->inet_opt);
569 if (inet_opt && inet_opt->opt.srr)
570 daddr = inet_opt->opt.faddr;
571 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
572 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
573 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
574 inet_sk_flowi_flags(sk),
575 daddr, inet->inet_saddr, 0, 0);
576 rcu_read_unlock();
577 }
578
579 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
580 const struct sk_buff *skb)
581 {
582 if (skb)
583 build_skb_flow_key(fl4, skb, sk);
584 else
585 build_sk_flow_key(fl4, sk);
586 }
587
588 static inline void rt_free(struct rtable *rt)
589 {
590 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
591 }
592
593 static DEFINE_SPINLOCK(fnhe_lock);
594
595 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
596 {
597 struct fib_nh_exception *fnhe, *oldest;
598 struct rtable *orig;
599
600 oldest = rcu_dereference(hash->chain);
601 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
602 fnhe = rcu_dereference(fnhe->fnhe_next)) {
603 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
604 oldest = fnhe;
605 }
606 orig = rcu_dereference(oldest->fnhe_rth);
607 if (orig) {
608 RCU_INIT_POINTER(oldest->fnhe_rth, NULL);
609 rt_free(orig);
610 }
611 return oldest;
612 }
613
614 static inline u32 fnhe_hashfun(__be32 daddr)
615 {
616 u32 hval;
617
618 hval = (__force u32) daddr;
619 hval ^= (hval >> 11) ^ (hval >> 22);
620
621 return hval & (FNHE_HASH_SIZE - 1);
622 }
623
624 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
625 u32 pmtu, unsigned long expires)
626 {
627 struct fnhe_hash_bucket *hash;
628 struct fib_nh_exception *fnhe;
629 int depth;
630 u32 hval = fnhe_hashfun(daddr);
631
632 spin_lock_bh(&fnhe_lock);
633
634 hash = nh->nh_exceptions;
635 if (!hash) {
636 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
637 if (!hash)
638 goto out_unlock;
639 nh->nh_exceptions = hash;
640 }
641
642 hash += hval;
643
644 depth = 0;
645 for (fnhe = rcu_dereference(hash->chain); fnhe;
646 fnhe = rcu_dereference(fnhe->fnhe_next)) {
647 if (fnhe->fnhe_daddr == daddr)
648 break;
649 depth++;
650 }
651
652 if (fnhe) {
653 if (gw)
654 fnhe->fnhe_gw = gw;
655 if (pmtu) {
656 fnhe->fnhe_pmtu = pmtu;
657 fnhe->fnhe_expires = expires;
658 }
659 } else {
660 if (depth > FNHE_RECLAIM_DEPTH)
661 fnhe = fnhe_oldest(hash);
662 else {
663 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
664 if (!fnhe)
665 goto out_unlock;
666
667 fnhe->fnhe_next = hash->chain;
668 rcu_assign_pointer(hash->chain, fnhe);
669 }
670 fnhe->fnhe_daddr = daddr;
671 fnhe->fnhe_gw = gw;
672 fnhe->fnhe_pmtu = pmtu;
673 fnhe->fnhe_expires = expires;
674 }
675
676 fnhe->fnhe_stamp = jiffies;
677
678 out_unlock:
679 spin_unlock_bh(&fnhe_lock);
680 return;
681 }
682
683 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
684 bool kill_route)
685 {
686 __be32 new_gw = icmp_hdr(skb)->un.gateway;
687 __be32 old_gw = ip_hdr(skb)->saddr;
688 struct net_device *dev = skb->dev;
689 struct in_device *in_dev;
690 struct fib_result res;
691 struct neighbour *n;
692 struct net *net;
693
694 switch (icmp_hdr(skb)->code & 7) {
695 case ICMP_REDIR_NET:
696 case ICMP_REDIR_NETTOS:
697 case ICMP_REDIR_HOST:
698 case ICMP_REDIR_HOSTTOS:
699 break;
700
701 default:
702 return;
703 }
704
705 if (rt->rt_gateway != old_gw)
706 return;
707
708 in_dev = __in_dev_get_rcu(dev);
709 if (!in_dev)
710 return;
711
712 net = dev_net(dev);
713 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
714 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
715 ipv4_is_zeronet(new_gw))
716 goto reject_redirect;
717
718 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
719 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
720 goto reject_redirect;
721 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
722 goto reject_redirect;
723 } else {
724 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
725 goto reject_redirect;
726 }
727
728 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
729 if (n) {
730 if (!(n->nud_state & NUD_VALID)) {
731 neigh_event_send(n, NULL);
732 } else {
733 if (fib_lookup(net, fl4, &res) == 0) {
734 struct fib_nh *nh = &FIB_RES_NH(res);
735
736 update_or_create_fnhe(nh, fl4->daddr, new_gw,
737 0, 0);
738 }
739 if (kill_route)
740 rt->dst.obsolete = DST_OBSOLETE_KILL;
741 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
742 }
743 neigh_release(n);
744 }
745 return;
746
747 reject_redirect:
748 #ifdef CONFIG_IP_ROUTE_VERBOSE
749 if (IN_DEV_LOG_MARTIANS(in_dev)) {
750 const struct iphdr *iph = (const struct iphdr *) skb->data;
751 __be32 daddr = iph->daddr;
752 __be32 saddr = iph->saddr;
753
754 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
755 " Advised path = %pI4 -> %pI4\n",
756 &old_gw, dev->name, &new_gw,
757 &saddr, &daddr);
758 }
759 #endif
760 ;
761 }
762
763 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
764 {
765 struct rtable *rt;
766 struct flowi4 fl4;
767
768 rt = (struct rtable *) dst;
769
770 ip_rt_build_flow_key(&fl4, sk, skb);
771 __ip_do_redirect(rt, skb, &fl4, true);
772 }
773
774 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
775 {
776 struct rtable *rt = (struct rtable *)dst;
777 struct dst_entry *ret = dst;
778
779 if (rt) {
780 if (dst->obsolete > 0) {
781 ip_rt_put(rt);
782 ret = NULL;
783 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
784 rt->dst.expires) {
785 ip_rt_put(rt);
786 ret = NULL;
787 }
788 }
789 return ret;
790 }
791
792 /*
793 * Algorithm:
794 * 1. The first ip_rt_redirect_number redirects are sent
795 * with exponential backoff, then we stop sending them at all,
796 * assuming that the host ignores our redirects.
797 * 2. If we did not see packets requiring redirects
798 * during ip_rt_redirect_silence, we assume that the host
799 * forgot redirected route and start to send redirects again.
800 *
801 * This algorithm is much cheaper and more intelligent than dumb load limiting
802 * in icmp.c.
803 *
804 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
805 * and "frag. need" (breaks PMTU discovery) in icmp.c.
806 */
807
808 void ip_rt_send_redirect(struct sk_buff *skb)
809 {
810 struct rtable *rt = skb_rtable(skb);
811 struct in_device *in_dev;
812 struct inet_peer *peer;
813 struct net *net;
814 int log_martians;
815
816 rcu_read_lock();
817 in_dev = __in_dev_get_rcu(rt->dst.dev);
818 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
819 rcu_read_unlock();
820 return;
821 }
822 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
823 rcu_read_unlock();
824
825 net = dev_net(rt->dst.dev);
826 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
827 if (!peer) {
828 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
829 return;
830 }
831
832 /* No redirected packets during ip_rt_redirect_silence;
833 * reset the algorithm.
834 */
835 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
836 peer->rate_tokens = 0;
837
838 /* Too many ignored redirects; do not send anything
839 * set dst.rate_last to the last seen redirected packet.
840 */
841 if (peer->rate_tokens >= ip_rt_redirect_number) {
842 peer->rate_last = jiffies;
843 goto out_put_peer;
844 }
845
846 /* Check for load limit; set rate_last to the latest sent
847 * redirect.
848 */
849 if (peer->rate_tokens == 0 ||
850 time_after(jiffies,
851 (peer->rate_last +
852 (ip_rt_redirect_load << peer->rate_tokens)))) {
853 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
854 peer->rate_last = jiffies;
855 ++peer->rate_tokens;
856 #ifdef CONFIG_IP_ROUTE_VERBOSE
857 if (log_martians &&
858 peer->rate_tokens == ip_rt_redirect_number)
859 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
860 &ip_hdr(skb)->saddr, inet_iif(skb),
861 &ip_hdr(skb)->daddr, &rt->rt_gateway);
862 #endif
863 }
864 out_put_peer:
865 inet_putpeer(peer);
866 }
867
868 static int ip_error(struct sk_buff *skb)
869 {
870 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
871 struct rtable *rt = skb_rtable(skb);
872 struct inet_peer *peer;
873 unsigned long now;
874 struct net *net;
875 bool send;
876 int code;
877
878 net = dev_net(rt->dst.dev);
879 if (!IN_DEV_FORWARD(in_dev)) {
880 switch (rt->dst.error) {
881 case EHOSTUNREACH:
882 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
883 break;
884
885 case ENETUNREACH:
886 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
887 break;
888 }
889 goto out;
890 }
891
892 switch (rt->dst.error) {
893 case EINVAL:
894 default:
895 goto out;
896 case EHOSTUNREACH:
897 code = ICMP_HOST_UNREACH;
898 break;
899 case ENETUNREACH:
900 code = ICMP_NET_UNREACH;
901 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
902 break;
903 case EACCES:
904 code = ICMP_PKT_FILTERED;
905 break;
906 }
907
908 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
909
910 send = true;
911 if (peer) {
912 now = jiffies;
913 peer->rate_tokens += now - peer->rate_last;
914 if (peer->rate_tokens > ip_rt_error_burst)
915 peer->rate_tokens = ip_rt_error_burst;
916 peer->rate_last = now;
917 if (peer->rate_tokens >= ip_rt_error_cost)
918 peer->rate_tokens -= ip_rt_error_cost;
919 else
920 send = false;
921 inet_putpeer(peer);
922 }
923 if (send)
924 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
925
926 out: kfree_skb(skb);
927 return 0;
928 }
929
930 static u32 __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
931 {
932 struct fib_result res;
933
934 if (mtu < ip_rt_min_pmtu)
935 mtu = ip_rt_min_pmtu;
936
937 rcu_read_lock();
938 if (fib_lookup(dev_net(rt->dst.dev), fl4, &res) == 0) {
939 struct fib_nh *nh = &FIB_RES_NH(res);
940
941 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
942 jiffies + ip_rt_mtu_expires);
943 }
944 rcu_read_unlock();
945 return mtu;
946 }
947
948 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
949 struct sk_buff *skb, u32 mtu)
950 {
951 struct rtable *rt = (struct rtable *) dst;
952 struct flowi4 fl4;
953
954 ip_rt_build_flow_key(&fl4, sk, skb);
955 mtu = __ip_rt_update_pmtu(rt, &fl4, mtu);
956
957 if (!rt->rt_pmtu) {
958 dst->obsolete = DST_OBSOLETE_KILL;
959 } else {
960 rt->rt_pmtu = mtu;
961 rt->dst.expires = max(1UL, jiffies + ip_rt_mtu_expires);
962 }
963 }
964
965 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
966 int oif, u32 mark, u8 protocol, int flow_flags)
967 {
968 const struct iphdr *iph = (const struct iphdr *) skb->data;
969 struct flowi4 fl4;
970 struct rtable *rt;
971
972 __build_flow_key(&fl4, NULL, iph, oif,
973 RT_TOS(iph->tos), protocol, mark, flow_flags);
974 rt = __ip_route_output_key(net, &fl4);
975 if (!IS_ERR(rt)) {
976 __ip_rt_update_pmtu(rt, &fl4, mtu);
977 ip_rt_put(rt);
978 }
979 }
980 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
981
982 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
983 {
984 const struct iphdr *iph = (const struct iphdr *) skb->data;
985 struct flowi4 fl4;
986 struct rtable *rt;
987
988 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
989 rt = __ip_route_output_key(sock_net(sk), &fl4);
990 if (!IS_ERR(rt)) {
991 __ip_rt_update_pmtu(rt, &fl4, mtu);
992 ip_rt_put(rt);
993 }
994 }
995 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
996
997 void ipv4_redirect(struct sk_buff *skb, struct net *net,
998 int oif, u32 mark, u8 protocol, int flow_flags)
999 {
1000 const struct iphdr *iph = (const struct iphdr *) skb->data;
1001 struct flowi4 fl4;
1002 struct rtable *rt;
1003
1004 __build_flow_key(&fl4, NULL, iph, oif,
1005 RT_TOS(iph->tos), protocol, mark, flow_flags);
1006 rt = __ip_route_output_key(net, &fl4);
1007 if (!IS_ERR(rt)) {
1008 __ip_do_redirect(rt, skb, &fl4, false);
1009 ip_rt_put(rt);
1010 }
1011 }
1012 EXPORT_SYMBOL_GPL(ipv4_redirect);
1013
1014 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1015 {
1016 const struct iphdr *iph = (const struct iphdr *) skb->data;
1017 struct flowi4 fl4;
1018 struct rtable *rt;
1019
1020 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1021 rt = __ip_route_output_key(sock_net(sk), &fl4);
1022 if (!IS_ERR(rt)) {
1023 __ip_do_redirect(rt, skb, &fl4, false);
1024 ip_rt_put(rt);
1025 }
1026 }
1027 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1028
1029 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1030 {
1031 struct rtable *rt = (struct rtable *) dst;
1032
1033 /* All IPV4 dsts are created with ->obsolete set to the value
1034 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1035 * into this function always.
1036 *
1037 * When a PMTU/redirect information update invalidates a
1038 * route, this is indicated by setting obsolete to
1039 * DST_OBSOLETE_KILL.
1040 */
1041 if (dst->obsolete == DST_OBSOLETE_KILL || rt_is_expired(rt))
1042 return NULL;
1043 return dst;
1044 }
1045
1046 static void ipv4_link_failure(struct sk_buff *skb)
1047 {
1048 struct rtable *rt;
1049
1050 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1051
1052 rt = skb_rtable(skb);
1053 if (rt)
1054 dst_set_expires(&rt->dst, 0);
1055 }
1056
1057 static int ip_rt_bug(struct sk_buff *skb)
1058 {
1059 pr_debug("%s: %pI4 -> %pI4, %s\n",
1060 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1061 skb->dev ? skb->dev->name : "?");
1062 kfree_skb(skb);
1063 WARN_ON(1);
1064 return 0;
1065 }
1066
1067 /*
1068 We do not cache source address of outgoing interface,
1069 because it is used only by IP RR, TS and SRR options,
1070 so that it out of fast path.
1071
1072 BTW remember: "addr" is allowed to be not aligned
1073 in IP options!
1074 */
1075
1076 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1077 {
1078 __be32 src;
1079
1080 if (rt_is_output_route(rt))
1081 src = ip_hdr(skb)->saddr;
1082 else {
1083 struct fib_result res;
1084 struct flowi4 fl4;
1085 struct iphdr *iph;
1086
1087 iph = ip_hdr(skb);
1088
1089 memset(&fl4, 0, sizeof(fl4));
1090 fl4.daddr = iph->daddr;
1091 fl4.saddr = iph->saddr;
1092 fl4.flowi4_tos = RT_TOS(iph->tos);
1093 fl4.flowi4_oif = rt->dst.dev->ifindex;
1094 fl4.flowi4_iif = skb->dev->ifindex;
1095 fl4.flowi4_mark = skb->mark;
1096
1097 rcu_read_lock();
1098 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1099 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1100 else
1101 src = inet_select_addr(rt->dst.dev,
1102 rt_nexthop(rt, iph->daddr),
1103 RT_SCOPE_UNIVERSE);
1104 rcu_read_unlock();
1105 }
1106 memcpy(addr, &src, 4);
1107 }
1108
1109 #ifdef CONFIG_IP_ROUTE_CLASSID
1110 static void set_class_tag(struct rtable *rt, u32 tag)
1111 {
1112 if (!(rt->dst.tclassid & 0xFFFF))
1113 rt->dst.tclassid |= tag & 0xFFFF;
1114 if (!(rt->dst.tclassid & 0xFFFF0000))
1115 rt->dst.tclassid |= tag & 0xFFFF0000;
1116 }
1117 #endif
1118
1119 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1120 {
1121 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1122
1123 if (advmss == 0) {
1124 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1125 ip_rt_min_advmss);
1126 if (advmss > 65535 - 40)
1127 advmss = 65535 - 40;
1128 }
1129 return advmss;
1130 }
1131
1132 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1133 {
1134 const struct rtable *rt = (const struct rtable *) dst;
1135 unsigned int mtu = rt->rt_pmtu;
1136
1137 if (mtu && time_after_eq(jiffies, rt->dst.expires))
1138 mtu = 0;
1139
1140 if (!mtu)
1141 mtu = dst_metric_raw(dst, RTAX_MTU);
1142
1143 if (mtu && rt_is_output_route(rt))
1144 return mtu;
1145
1146 mtu = dst->dev->mtu;
1147
1148 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1149 if (rt->rt_gateway && mtu > 576)
1150 mtu = 576;
1151 }
1152
1153 if (mtu > IP_MAX_MTU)
1154 mtu = IP_MAX_MTU;
1155
1156 return mtu;
1157 }
1158
1159 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1160 {
1161 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1162 struct fib_nh_exception *fnhe;
1163 u32 hval;
1164
1165 if (!hash)
1166 return NULL;
1167
1168 hval = fnhe_hashfun(daddr);
1169
1170 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1171 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1172 if (fnhe->fnhe_daddr == daddr)
1173 return fnhe;
1174 }
1175 return NULL;
1176 }
1177
1178 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1179 __be32 daddr)
1180 {
1181 bool ret = false;
1182
1183 spin_lock_bh(&fnhe_lock);
1184
1185 if (daddr == fnhe->fnhe_daddr) {
1186 struct rtable *orig;
1187
1188 if (fnhe->fnhe_pmtu) {
1189 unsigned long expires = fnhe->fnhe_expires;
1190 unsigned long diff = expires - jiffies;
1191
1192 if (time_before(jiffies, expires)) {
1193 rt->rt_pmtu = fnhe->fnhe_pmtu;
1194 dst_set_expires(&rt->dst, diff);
1195 }
1196 }
1197 if (fnhe->fnhe_gw) {
1198 rt->rt_flags |= RTCF_REDIRECTED;
1199 rt->rt_gateway = fnhe->fnhe_gw;
1200 }
1201
1202 orig = rcu_dereference(fnhe->fnhe_rth);
1203 rcu_assign_pointer(fnhe->fnhe_rth, rt);
1204 if (orig)
1205 rt_free(orig);
1206
1207 fnhe->fnhe_stamp = jiffies;
1208 ret = true;
1209 } else {
1210 /* Routes we intend to cache in nexthop exception have
1211 * the DST_NOCACHE bit clear. However, if we are
1212 * unsuccessful at storing this route into the cache
1213 * we really need to set it.
1214 */
1215 rt->dst.flags |= DST_NOCACHE;
1216 }
1217 spin_unlock_bh(&fnhe_lock);
1218
1219 return ret;
1220 }
1221
1222 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1223 {
1224 struct rtable *orig, *prev, **p;
1225 bool ret = true;
1226
1227 if (rt_is_input_route(rt)) {
1228 p = (struct rtable **)&nh->nh_rth_input;
1229 } else {
1230 if (!nh->nh_pcpu_rth_output)
1231 goto nocache;
1232 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1233 }
1234 orig = *p;
1235
1236 prev = cmpxchg(p, orig, rt);
1237 if (prev == orig) {
1238 if (orig)
1239 rt_free(orig);
1240 } else {
1241 /* Routes we intend to cache in the FIB nexthop have
1242 * the DST_NOCACHE bit clear. However, if we are
1243 * unsuccessful at storing this route into the cache
1244 * we really need to set it.
1245 */
1246 nocache:
1247 rt->dst.flags |= DST_NOCACHE;
1248 ret = false;
1249 }
1250
1251 return ret;
1252 }
1253
1254 static DEFINE_SPINLOCK(rt_uncached_lock);
1255 static LIST_HEAD(rt_uncached_list);
1256
1257 static void rt_add_uncached_list(struct rtable *rt)
1258 {
1259 spin_lock_bh(&rt_uncached_lock);
1260 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1261 spin_unlock_bh(&rt_uncached_lock);
1262 }
1263
1264 static void ipv4_dst_destroy(struct dst_entry *dst)
1265 {
1266 struct rtable *rt = (struct rtable *) dst;
1267
1268 if (!list_empty(&rt->rt_uncached)) {
1269 spin_lock_bh(&rt_uncached_lock);
1270 list_del(&rt->rt_uncached);
1271 spin_unlock_bh(&rt_uncached_lock);
1272 }
1273 }
1274
1275 void rt_flush_dev(struct net_device *dev)
1276 {
1277 if (!list_empty(&rt_uncached_list)) {
1278 struct net *net = dev_net(dev);
1279 struct rtable *rt;
1280
1281 spin_lock_bh(&rt_uncached_lock);
1282 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1283 if (rt->dst.dev != dev)
1284 continue;
1285 rt->dst.dev = net->loopback_dev;
1286 dev_hold(rt->dst.dev);
1287 dev_put(dev);
1288 }
1289 spin_unlock_bh(&rt_uncached_lock);
1290 }
1291 }
1292
1293 static bool rt_cache_valid(const struct rtable *rt)
1294 {
1295 return rt &&
1296 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1297 !rt_is_expired(rt);
1298 }
1299
1300 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1301 const struct fib_result *res,
1302 struct fib_nh_exception *fnhe,
1303 struct fib_info *fi, u16 type, u32 itag)
1304 {
1305 bool cached = false;
1306
1307 if (fi) {
1308 struct fib_nh *nh = &FIB_RES_NH(*res);
1309
1310 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK)
1311 rt->rt_gateway = nh->nh_gw;
1312 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1313 #ifdef CONFIG_IP_ROUTE_CLASSID
1314 rt->dst.tclassid = nh->nh_tclassid;
1315 #endif
1316 if (unlikely(fnhe))
1317 cached = rt_bind_exception(rt, fnhe, daddr);
1318 else if (!(rt->dst.flags & DST_NOCACHE))
1319 cached = rt_cache_route(nh, rt);
1320 }
1321 if (unlikely(!cached))
1322 rt_add_uncached_list(rt);
1323
1324 #ifdef CONFIG_IP_ROUTE_CLASSID
1325 #ifdef CONFIG_IP_MULTIPLE_TABLES
1326 set_class_tag(rt, res->tclassid);
1327 #endif
1328 set_class_tag(rt, itag);
1329 #endif
1330 }
1331
1332 static struct rtable *rt_dst_alloc(struct net_device *dev,
1333 bool nopolicy, bool noxfrm, bool will_cache)
1334 {
1335 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1336 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1337 (nopolicy ? DST_NOPOLICY : 0) |
1338 (noxfrm ? DST_NOXFRM : 0));
1339 }
1340
1341 /* called in rcu_read_lock() section */
1342 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1343 u8 tos, struct net_device *dev, int our)
1344 {
1345 struct rtable *rth;
1346 struct in_device *in_dev = __in_dev_get_rcu(dev);
1347 u32 itag = 0;
1348 int err;
1349
1350 /* Primary sanity checks. */
1351
1352 if (in_dev == NULL)
1353 return -EINVAL;
1354
1355 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1356 skb->protocol != htons(ETH_P_IP))
1357 goto e_inval;
1358
1359 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1360 if (ipv4_is_loopback(saddr))
1361 goto e_inval;
1362
1363 if (ipv4_is_zeronet(saddr)) {
1364 if (!ipv4_is_local_multicast(daddr))
1365 goto e_inval;
1366 } else {
1367 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1368 in_dev, &itag);
1369 if (err < 0)
1370 goto e_err;
1371 }
1372 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1373 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1374 if (!rth)
1375 goto e_nobufs;
1376
1377 #ifdef CONFIG_IP_ROUTE_CLASSID
1378 rth->dst.tclassid = itag;
1379 #endif
1380 rth->dst.output = ip_rt_bug;
1381
1382 rth->rt_genid = rt_genid(dev_net(dev));
1383 rth->rt_flags = RTCF_MULTICAST;
1384 rth->rt_type = RTN_MULTICAST;
1385 rth->rt_is_input= 1;
1386 rth->rt_iif = 0;
1387 rth->rt_pmtu = 0;
1388 rth->rt_gateway = 0;
1389 INIT_LIST_HEAD(&rth->rt_uncached);
1390 if (our) {
1391 rth->dst.input= ip_local_deliver;
1392 rth->rt_flags |= RTCF_LOCAL;
1393 }
1394
1395 #ifdef CONFIG_IP_MROUTE
1396 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1397 rth->dst.input = ip_mr_input;
1398 #endif
1399 RT_CACHE_STAT_INC(in_slow_mc);
1400
1401 skb_dst_set(skb, &rth->dst);
1402 return 0;
1403
1404 e_nobufs:
1405 return -ENOBUFS;
1406 e_inval:
1407 return -EINVAL;
1408 e_err:
1409 return err;
1410 }
1411
1412
1413 static void ip_handle_martian_source(struct net_device *dev,
1414 struct in_device *in_dev,
1415 struct sk_buff *skb,
1416 __be32 daddr,
1417 __be32 saddr)
1418 {
1419 RT_CACHE_STAT_INC(in_martian_src);
1420 #ifdef CONFIG_IP_ROUTE_VERBOSE
1421 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1422 /*
1423 * RFC1812 recommendation, if source is martian,
1424 * the only hint is MAC header.
1425 */
1426 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1427 &daddr, &saddr, dev->name);
1428 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1429 print_hex_dump(KERN_WARNING, "ll header: ",
1430 DUMP_PREFIX_OFFSET, 16, 1,
1431 skb_mac_header(skb),
1432 dev->hard_header_len, true);
1433 }
1434 }
1435 #endif
1436 }
1437
1438 /* called in rcu_read_lock() section */
1439 static int __mkroute_input(struct sk_buff *skb,
1440 const struct fib_result *res,
1441 struct in_device *in_dev,
1442 __be32 daddr, __be32 saddr, u32 tos)
1443 {
1444 struct rtable *rth;
1445 int err;
1446 struct in_device *out_dev;
1447 unsigned int flags = 0;
1448 bool do_cache;
1449 u32 itag;
1450
1451 /* get a working reference to the output device */
1452 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1453 if (out_dev == NULL) {
1454 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1455 return -EINVAL;
1456 }
1457
1458
1459 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1460 in_dev->dev, in_dev, &itag);
1461 if (err < 0) {
1462 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1463 saddr);
1464
1465 goto cleanup;
1466 }
1467
1468 if (out_dev == in_dev && err &&
1469 (IN_DEV_SHARED_MEDIA(out_dev) ||
1470 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1471 flags |= RTCF_DOREDIRECT;
1472
1473 if (skb->protocol != htons(ETH_P_IP)) {
1474 /* Not IP (i.e. ARP). Do not create route, if it is
1475 * invalid for proxy arp. DNAT routes are always valid.
1476 *
1477 * Proxy arp feature have been extended to allow, ARP
1478 * replies back to the same interface, to support
1479 * Private VLAN switch technologies. See arp.c.
1480 */
1481 if (out_dev == in_dev &&
1482 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1483 err = -EINVAL;
1484 goto cleanup;
1485 }
1486 }
1487
1488 do_cache = false;
1489 if (res->fi) {
1490 if (!itag) {
1491 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1492 if (rt_cache_valid(rth)) {
1493 skb_dst_set_noref(skb, &rth->dst);
1494 goto out;
1495 }
1496 do_cache = true;
1497 }
1498 }
1499
1500 rth = rt_dst_alloc(out_dev->dev,
1501 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1502 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1503 if (!rth) {
1504 err = -ENOBUFS;
1505 goto cleanup;
1506 }
1507
1508 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
1509 rth->rt_flags = flags;
1510 rth->rt_type = res->type;
1511 rth->rt_is_input = 1;
1512 rth->rt_iif = 0;
1513 rth->rt_pmtu = 0;
1514 rth->rt_gateway = 0;
1515 INIT_LIST_HEAD(&rth->rt_uncached);
1516
1517 rth->dst.input = ip_forward;
1518 rth->dst.output = ip_output;
1519
1520 rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag);
1521 skb_dst_set(skb, &rth->dst);
1522 out:
1523 err = 0;
1524 cleanup:
1525 return err;
1526 }
1527
1528 static int ip_mkroute_input(struct sk_buff *skb,
1529 struct fib_result *res,
1530 const struct flowi4 *fl4,
1531 struct in_device *in_dev,
1532 __be32 daddr, __be32 saddr, u32 tos)
1533 {
1534 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1535 if (res->fi && res->fi->fib_nhs > 1)
1536 fib_select_multipath(res);
1537 #endif
1538
1539 /* create a routing cache entry */
1540 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1541 }
1542
1543 /*
1544 * NOTE. We drop all the packets that has local source
1545 * addresses, because every properly looped back packet
1546 * must have correct destination already attached by output routine.
1547 *
1548 * Such approach solves two big problems:
1549 * 1. Not simplex devices are handled properly.
1550 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1551 * called with rcu_read_lock()
1552 */
1553
1554 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1555 u8 tos, struct net_device *dev)
1556 {
1557 struct fib_result res;
1558 struct in_device *in_dev = __in_dev_get_rcu(dev);
1559 struct flowi4 fl4;
1560 unsigned int flags = 0;
1561 u32 itag = 0;
1562 struct rtable *rth;
1563 int err = -EINVAL;
1564 struct net *net = dev_net(dev);
1565 bool do_cache;
1566
1567 /* IP on this device is disabled. */
1568
1569 if (!in_dev)
1570 goto out;
1571
1572 /* Check for the most weird martians, which can be not detected
1573 by fib_lookup.
1574 */
1575
1576 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1577 goto martian_source;
1578
1579 res.fi = NULL;
1580 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1581 goto brd_input;
1582
1583 /* Accept zero addresses only to limited broadcast;
1584 * I even do not know to fix it or not. Waiting for complains :-)
1585 */
1586 if (ipv4_is_zeronet(saddr))
1587 goto martian_source;
1588
1589 if (ipv4_is_zeronet(daddr))
1590 goto martian_destination;
1591
1592 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) {
1593 if (ipv4_is_loopback(daddr))
1594 goto martian_destination;
1595
1596 if (ipv4_is_loopback(saddr))
1597 goto martian_source;
1598 }
1599
1600 /*
1601 * Now we are ready to route packet.
1602 */
1603 fl4.flowi4_oif = 0;
1604 fl4.flowi4_iif = dev->ifindex;
1605 fl4.flowi4_mark = skb->mark;
1606 fl4.flowi4_tos = tos;
1607 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1608 fl4.daddr = daddr;
1609 fl4.saddr = saddr;
1610 err = fib_lookup(net, &fl4, &res);
1611 if (err != 0)
1612 goto no_route;
1613
1614 RT_CACHE_STAT_INC(in_slow_tot);
1615
1616 if (res.type == RTN_BROADCAST)
1617 goto brd_input;
1618
1619 if (res.type == RTN_LOCAL) {
1620 err = fib_validate_source(skb, saddr, daddr, tos,
1621 net->loopback_dev->ifindex,
1622 dev, in_dev, &itag);
1623 if (err < 0)
1624 goto martian_source_keep_err;
1625 goto local_input;
1626 }
1627
1628 if (!IN_DEV_FORWARD(in_dev))
1629 goto no_route;
1630 if (res.type != RTN_UNICAST)
1631 goto martian_destination;
1632
1633 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1634 out: return err;
1635
1636 brd_input:
1637 if (skb->protocol != htons(ETH_P_IP))
1638 goto e_inval;
1639
1640 if (!ipv4_is_zeronet(saddr)) {
1641 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1642 in_dev, &itag);
1643 if (err < 0)
1644 goto martian_source_keep_err;
1645 }
1646 flags |= RTCF_BROADCAST;
1647 res.type = RTN_BROADCAST;
1648 RT_CACHE_STAT_INC(in_brd);
1649
1650 local_input:
1651 do_cache = false;
1652 if (res.fi) {
1653 if (!itag) {
1654 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1655 if (rt_cache_valid(rth)) {
1656 skb_dst_set_noref(skb, &rth->dst);
1657 err = 0;
1658 goto out;
1659 }
1660 do_cache = true;
1661 }
1662 }
1663
1664 rth = rt_dst_alloc(net->loopback_dev,
1665 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1666 if (!rth)
1667 goto e_nobufs;
1668
1669 rth->dst.input= ip_local_deliver;
1670 rth->dst.output= ip_rt_bug;
1671 #ifdef CONFIG_IP_ROUTE_CLASSID
1672 rth->dst.tclassid = itag;
1673 #endif
1674
1675 rth->rt_genid = rt_genid(net);
1676 rth->rt_flags = flags|RTCF_LOCAL;
1677 rth->rt_type = res.type;
1678 rth->rt_is_input = 1;
1679 rth->rt_iif = 0;
1680 rth->rt_pmtu = 0;
1681 rth->rt_gateway = 0;
1682 INIT_LIST_HEAD(&rth->rt_uncached);
1683 if (res.type == RTN_UNREACHABLE) {
1684 rth->dst.input= ip_error;
1685 rth->dst.error= -err;
1686 rth->rt_flags &= ~RTCF_LOCAL;
1687 }
1688 if (do_cache)
1689 rt_cache_route(&FIB_RES_NH(res), rth);
1690 skb_dst_set(skb, &rth->dst);
1691 err = 0;
1692 goto out;
1693
1694 no_route:
1695 RT_CACHE_STAT_INC(in_no_route);
1696 res.type = RTN_UNREACHABLE;
1697 if (err == -ESRCH)
1698 err = -ENETUNREACH;
1699 goto local_input;
1700
1701 /*
1702 * Do not cache martian addresses: they should be logged (RFC1812)
1703 */
1704 martian_destination:
1705 RT_CACHE_STAT_INC(in_martian_dst);
1706 #ifdef CONFIG_IP_ROUTE_VERBOSE
1707 if (IN_DEV_LOG_MARTIANS(in_dev))
1708 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1709 &daddr, &saddr, dev->name);
1710 #endif
1711
1712 e_inval:
1713 err = -EINVAL;
1714 goto out;
1715
1716 e_nobufs:
1717 err = -ENOBUFS;
1718 goto out;
1719
1720 martian_source:
1721 err = -EINVAL;
1722 martian_source_keep_err:
1723 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1724 goto out;
1725 }
1726
1727 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1728 u8 tos, struct net_device *dev)
1729 {
1730 int res;
1731
1732 rcu_read_lock();
1733
1734 /* Multicast recognition logic is moved from route cache to here.
1735 The problem was that too many Ethernet cards have broken/missing
1736 hardware multicast filters :-( As result the host on multicasting
1737 network acquires a lot of useless route cache entries, sort of
1738 SDR messages from all the world. Now we try to get rid of them.
1739 Really, provided software IP multicast filter is organized
1740 reasonably (at least, hashed), it does not result in a slowdown
1741 comparing with route cache reject entries.
1742 Note, that multicast routers are not affected, because
1743 route cache entry is created eventually.
1744 */
1745 if (ipv4_is_multicast(daddr)) {
1746 struct in_device *in_dev = __in_dev_get_rcu(dev);
1747
1748 if (in_dev) {
1749 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1750 ip_hdr(skb)->protocol);
1751 if (our
1752 #ifdef CONFIG_IP_MROUTE
1753 ||
1754 (!ipv4_is_local_multicast(daddr) &&
1755 IN_DEV_MFORWARD(in_dev))
1756 #endif
1757 ) {
1758 int res = ip_route_input_mc(skb, daddr, saddr,
1759 tos, dev, our);
1760 rcu_read_unlock();
1761 return res;
1762 }
1763 }
1764 rcu_read_unlock();
1765 return -EINVAL;
1766 }
1767 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1768 rcu_read_unlock();
1769 return res;
1770 }
1771 EXPORT_SYMBOL(ip_route_input_noref);
1772
1773 /* called with rcu_read_lock() */
1774 static struct rtable *__mkroute_output(const struct fib_result *res,
1775 const struct flowi4 *fl4, int orig_oif,
1776 struct net_device *dev_out,
1777 unsigned int flags)
1778 {
1779 struct fib_info *fi = res->fi;
1780 struct fib_nh_exception *fnhe;
1781 struct in_device *in_dev;
1782 u16 type = res->type;
1783 struct rtable *rth;
1784
1785 in_dev = __in_dev_get_rcu(dev_out);
1786 if (!in_dev)
1787 return ERR_PTR(-EINVAL);
1788
1789 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1790 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1791 return ERR_PTR(-EINVAL);
1792
1793 if (ipv4_is_lbcast(fl4->daddr))
1794 type = RTN_BROADCAST;
1795 else if (ipv4_is_multicast(fl4->daddr))
1796 type = RTN_MULTICAST;
1797 else if (ipv4_is_zeronet(fl4->daddr))
1798 return ERR_PTR(-EINVAL);
1799
1800 if (dev_out->flags & IFF_LOOPBACK)
1801 flags |= RTCF_LOCAL;
1802
1803 if (type == RTN_BROADCAST) {
1804 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1805 fi = NULL;
1806 } else if (type == RTN_MULTICAST) {
1807 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1808 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1809 fl4->flowi4_proto))
1810 flags &= ~RTCF_LOCAL;
1811 /* If multicast route do not exist use
1812 * default one, but do not gateway in this case.
1813 * Yes, it is hack.
1814 */
1815 if (fi && res->prefixlen < 4)
1816 fi = NULL;
1817 }
1818
1819 fnhe = NULL;
1820 if (fi) {
1821 struct rtable __rcu **prth;
1822
1823 fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr);
1824 if (fnhe)
1825 prth = &fnhe->fnhe_rth;
1826 else
1827 prth = __this_cpu_ptr(FIB_RES_NH(*res).nh_pcpu_rth_output);
1828 rth = rcu_dereference(*prth);
1829 if (rt_cache_valid(rth)) {
1830 dst_hold(&rth->dst);
1831 return rth;
1832 }
1833 }
1834 rth = rt_dst_alloc(dev_out,
1835 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1836 IN_DEV_CONF_GET(in_dev, NOXFRM),
1837 fi);
1838 if (!rth)
1839 return ERR_PTR(-ENOBUFS);
1840
1841 rth->dst.output = ip_output;
1842
1843 rth->rt_genid = rt_genid(dev_net(dev_out));
1844 rth->rt_flags = flags;
1845 rth->rt_type = type;
1846 rth->rt_is_input = 0;
1847 rth->rt_iif = orig_oif ? : 0;
1848 rth->rt_pmtu = 0;
1849 rth->rt_gateway = 0;
1850 INIT_LIST_HEAD(&rth->rt_uncached);
1851
1852 RT_CACHE_STAT_INC(out_slow_tot);
1853
1854 if (flags & RTCF_LOCAL)
1855 rth->dst.input = ip_local_deliver;
1856 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1857 if (flags & RTCF_LOCAL &&
1858 !(dev_out->flags & IFF_LOOPBACK)) {
1859 rth->dst.output = ip_mc_output;
1860 RT_CACHE_STAT_INC(out_slow_mc);
1861 }
1862 #ifdef CONFIG_IP_MROUTE
1863 if (type == RTN_MULTICAST) {
1864 if (IN_DEV_MFORWARD(in_dev) &&
1865 !ipv4_is_local_multicast(fl4->daddr)) {
1866 rth->dst.input = ip_mr_input;
1867 rth->dst.output = ip_mc_output;
1868 }
1869 }
1870 #endif
1871 }
1872
1873 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1874
1875 return rth;
1876 }
1877
1878 /*
1879 * Major route resolver routine.
1880 */
1881
1882 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1883 {
1884 struct net_device *dev_out = NULL;
1885 __u8 tos = RT_FL_TOS(fl4);
1886 unsigned int flags = 0;
1887 struct fib_result res;
1888 struct rtable *rth;
1889 int orig_oif;
1890
1891 res.tclassid = 0;
1892 res.fi = NULL;
1893 res.table = NULL;
1894
1895 orig_oif = fl4->flowi4_oif;
1896
1897 fl4->flowi4_iif = net->loopback_dev->ifindex;
1898 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
1899 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
1900 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
1901
1902 rcu_read_lock();
1903 if (fl4->saddr) {
1904 rth = ERR_PTR(-EINVAL);
1905 if (ipv4_is_multicast(fl4->saddr) ||
1906 ipv4_is_lbcast(fl4->saddr) ||
1907 ipv4_is_zeronet(fl4->saddr))
1908 goto out;
1909
1910 /* I removed check for oif == dev_out->oif here.
1911 It was wrong for two reasons:
1912 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
1913 is assigned to multiple interfaces.
1914 2. Moreover, we are allowed to send packets with saddr
1915 of another iface. --ANK
1916 */
1917
1918 if (fl4->flowi4_oif == 0 &&
1919 (ipv4_is_multicast(fl4->daddr) ||
1920 ipv4_is_lbcast(fl4->daddr))) {
1921 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1922 dev_out = __ip_dev_find(net, fl4->saddr, false);
1923 if (dev_out == NULL)
1924 goto out;
1925
1926 /* Special hack: user can direct multicasts
1927 and limited broadcast via necessary interface
1928 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
1929 This hack is not just for fun, it allows
1930 vic,vat and friends to work.
1931 They bind socket to loopback, set ttl to zero
1932 and expect that it will work.
1933 From the viewpoint of routing cache they are broken,
1934 because we are not allowed to build multicast path
1935 with loopback source addr (look, routing cache
1936 cannot know, that ttl is zero, so that packet
1937 will not leave this host and route is valid).
1938 Luckily, this hack is good workaround.
1939 */
1940
1941 fl4->flowi4_oif = dev_out->ifindex;
1942 goto make_route;
1943 }
1944
1945 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
1946 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1947 if (!__ip_dev_find(net, fl4->saddr, false))
1948 goto out;
1949 }
1950 }
1951
1952
1953 if (fl4->flowi4_oif) {
1954 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
1955 rth = ERR_PTR(-ENODEV);
1956 if (dev_out == NULL)
1957 goto out;
1958
1959 /* RACE: Check return value of inet_select_addr instead. */
1960 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
1961 rth = ERR_PTR(-ENETUNREACH);
1962 goto out;
1963 }
1964 if (ipv4_is_local_multicast(fl4->daddr) ||
1965 ipv4_is_lbcast(fl4->daddr)) {
1966 if (!fl4->saddr)
1967 fl4->saddr = inet_select_addr(dev_out, 0,
1968 RT_SCOPE_LINK);
1969 goto make_route;
1970 }
1971 if (fl4->saddr) {
1972 if (ipv4_is_multicast(fl4->daddr))
1973 fl4->saddr = inet_select_addr(dev_out, 0,
1974 fl4->flowi4_scope);
1975 else if (!fl4->daddr)
1976 fl4->saddr = inet_select_addr(dev_out, 0,
1977 RT_SCOPE_HOST);
1978 }
1979 }
1980
1981 if (!fl4->daddr) {
1982 fl4->daddr = fl4->saddr;
1983 if (!fl4->daddr)
1984 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
1985 dev_out = net->loopback_dev;
1986 fl4->flowi4_oif = net->loopback_dev->ifindex;
1987 res.type = RTN_LOCAL;
1988 flags |= RTCF_LOCAL;
1989 goto make_route;
1990 }
1991
1992 if (fib_lookup(net, fl4, &res)) {
1993 res.fi = NULL;
1994 res.table = NULL;
1995 if (fl4->flowi4_oif) {
1996 /* Apparently, routing tables are wrong. Assume,
1997 that the destination is on link.
1998
1999 WHY? DW.
2000 Because we are allowed to send to iface
2001 even if it has NO routes and NO assigned
2002 addresses. When oif is specified, routing
2003 tables are looked up with only one purpose:
2004 to catch if destination is gatewayed, rather than
2005 direct. Moreover, if MSG_DONTROUTE is set,
2006 we send packet, ignoring both routing tables
2007 and ifaddr state. --ANK
2008
2009
2010 We could make it even if oif is unknown,
2011 likely IPv6, but we do not.
2012 */
2013
2014 if (fl4->saddr == 0)
2015 fl4->saddr = inet_select_addr(dev_out, 0,
2016 RT_SCOPE_LINK);
2017 res.type = RTN_UNICAST;
2018 goto make_route;
2019 }
2020 rth = ERR_PTR(-ENETUNREACH);
2021 goto out;
2022 }
2023
2024 if (res.type == RTN_LOCAL) {
2025 if (!fl4->saddr) {
2026 if (res.fi->fib_prefsrc)
2027 fl4->saddr = res.fi->fib_prefsrc;
2028 else
2029 fl4->saddr = fl4->daddr;
2030 }
2031 dev_out = net->loopback_dev;
2032 fl4->flowi4_oif = dev_out->ifindex;
2033 flags |= RTCF_LOCAL;
2034 goto make_route;
2035 }
2036
2037 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2038 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2039 fib_select_multipath(&res);
2040 else
2041 #endif
2042 if (!res.prefixlen &&
2043 res.table->tb_num_default > 1 &&
2044 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2045 fib_select_default(&res);
2046
2047 if (!fl4->saddr)
2048 fl4->saddr = FIB_RES_PREFSRC(net, res);
2049
2050 dev_out = FIB_RES_DEV(res);
2051 fl4->flowi4_oif = dev_out->ifindex;
2052
2053
2054 make_route:
2055 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2056
2057 out:
2058 rcu_read_unlock();
2059 return rth;
2060 }
2061 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2062
2063 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2064 {
2065 return NULL;
2066 }
2067
2068 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2069 {
2070 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2071
2072 return mtu ? : dst->dev->mtu;
2073 }
2074
2075 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2076 struct sk_buff *skb, u32 mtu)
2077 {
2078 }
2079
2080 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2081 struct sk_buff *skb)
2082 {
2083 }
2084
2085 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2086 unsigned long old)
2087 {
2088 return NULL;
2089 }
2090
2091 static struct dst_ops ipv4_dst_blackhole_ops = {
2092 .family = AF_INET,
2093 .protocol = cpu_to_be16(ETH_P_IP),
2094 .check = ipv4_blackhole_dst_check,
2095 .mtu = ipv4_blackhole_mtu,
2096 .default_advmss = ipv4_default_advmss,
2097 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2098 .redirect = ipv4_rt_blackhole_redirect,
2099 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2100 .neigh_lookup = ipv4_neigh_lookup,
2101 };
2102
2103 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2104 {
2105 struct rtable *ort = (struct rtable *) dst_orig;
2106 struct rtable *rt;
2107
2108 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2109 if (rt) {
2110 struct dst_entry *new = &rt->dst;
2111
2112 new->__use = 1;
2113 new->input = dst_discard;
2114 new->output = dst_discard;
2115
2116 new->dev = ort->dst.dev;
2117 if (new->dev)
2118 dev_hold(new->dev);
2119
2120 rt->rt_is_input = ort->rt_is_input;
2121 rt->rt_iif = ort->rt_iif;
2122 rt->rt_pmtu = ort->rt_pmtu;
2123
2124 rt->rt_genid = rt_genid(net);
2125 rt->rt_flags = ort->rt_flags;
2126 rt->rt_type = ort->rt_type;
2127 rt->rt_gateway = ort->rt_gateway;
2128
2129 INIT_LIST_HEAD(&rt->rt_uncached);
2130
2131 dst_free(new);
2132 }
2133
2134 dst_release(dst_orig);
2135
2136 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2137 }
2138
2139 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2140 struct sock *sk)
2141 {
2142 struct rtable *rt = __ip_route_output_key(net, flp4);
2143
2144 if (IS_ERR(rt))
2145 return rt;
2146
2147 if (flp4->flowi4_proto)
2148 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2149 flowi4_to_flowi(flp4),
2150 sk, 0);
2151
2152 return rt;
2153 }
2154 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2155
2156 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2157 struct flowi4 *fl4, struct sk_buff *skb, u32 pid,
2158 u32 seq, int event, int nowait, unsigned int flags)
2159 {
2160 struct rtable *rt = skb_rtable(skb);
2161 struct rtmsg *r;
2162 struct nlmsghdr *nlh;
2163 unsigned long expires = 0;
2164 u32 error;
2165 u32 metrics[RTAX_MAX];
2166
2167 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2168 if (nlh == NULL)
2169 return -EMSGSIZE;
2170
2171 r = nlmsg_data(nlh);
2172 r->rtm_family = AF_INET;
2173 r->rtm_dst_len = 32;
2174 r->rtm_src_len = 0;
2175 r->rtm_tos = fl4->flowi4_tos;
2176 r->rtm_table = RT_TABLE_MAIN;
2177 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2178 goto nla_put_failure;
2179 r->rtm_type = rt->rt_type;
2180 r->rtm_scope = RT_SCOPE_UNIVERSE;
2181 r->rtm_protocol = RTPROT_UNSPEC;
2182 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2183 if (rt->rt_flags & RTCF_NOTIFY)
2184 r->rtm_flags |= RTM_F_NOTIFY;
2185
2186 if (nla_put_be32(skb, RTA_DST, dst))
2187 goto nla_put_failure;
2188 if (src) {
2189 r->rtm_src_len = 32;
2190 if (nla_put_be32(skb, RTA_SRC, src))
2191 goto nla_put_failure;
2192 }
2193 if (rt->dst.dev &&
2194 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2195 goto nla_put_failure;
2196 #ifdef CONFIG_IP_ROUTE_CLASSID
2197 if (rt->dst.tclassid &&
2198 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2199 goto nla_put_failure;
2200 #endif
2201 if (!rt_is_input_route(rt) &&
2202 fl4->saddr != src) {
2203 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2204 goto nla_put_failure;
2205 }
2206 if (rt->rt_gateway &&
2207 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2208 goto nla_put_failure;
2209
2210 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2211 if (rt->rt_pmtu)
2212 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2213 if (rtnetlink_put_metrics(skb, metrics) < 0)
2214 goto nla_put_failure;
2215
2216 if (fl4->flowi4_mark &&
2217 nla_put_be32(skb, RTA_MARK, fl4->flowi4_mark))
2218 goto nla_put_failure;
2219
2220 error = rt->dst.error;
2221 expires = rt->dst.expires;
2222 if (expires) {
2223 if (time_before(jiffies, expires))
2224 expires -= jiffies;
2225 else
2226 expires = 0;
2227 }
2228
2229 if (rt_is_input_route(rt)) {
2230 if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
2231 goto nla_put_failure;
2232 }
2233
2234 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2235 goto nla_put_failure;
2236
2237 return nlmsg_end(skb, nlh);
2238
2239 nla_put_failure:
2240 nlmsg_cancel(skb, nlh);
2241 return -EMSGSIZE;
2242 }
2243
2244 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
2245 {
2246 struct net *net = sock_net(in_skb->sk);
2247 struct rtmsg *rtm;
2248 struct nlattr *tb[RTA_MAX+1];
2249 struct rtable *rt = NULL;
2250 struct flowi4 fl4;
2251 __be32 dst = 0;
2252 __be32 src = 0;
2253 u32 iif;
2254 int err;
2255 int mark;
2256 struct sk_buff *skb;
2257
2258 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2259 if (err < 0)
2260 goto errout;
2261
2262 rtm = nlmsg_data(nlh);
2263
2264 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2265 if (skb == NULL) {
2266 err = -ENOBUFS;
2267 goto errout;
2268 }
2269
2270 /* Reserve room for dummy headers, this skb can pass
2271 through good chunk of routing engine.
2272 */
2273 skb_reset_mac_header(skb);
2274 skb_reset_network_header(skb);
2275
2276 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2277 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2278 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2279
2280 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2281 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2282 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2283 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2284
2285 memset(&fl4, 0, sizeof(fl4));
2286 fl4.daddr = dst;
2287 fl4.saddr = src;
2288 fl4.flowi4_tos = rtm->rtm_tos;
2289 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2290 fl4.flowi4_mark = mark;
2291
2292 if (iif) {
2293 struct net_device *dev;
2294
2295 dev = __dev_get_by_index(net, iif);
2296 if (dev == NULL) {
2297 err = -ENODEV;
2298 goto errout_free;
2299 }
2300
2301 skb->protocol = htons(ETH_P_IP);
2302 skb->dev = dev;
2303 skb->mark = mark;
2304 local_bh_disable();
2305 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2306 local_bh_enable();
2307
2308 rt = skb_rtable(skb);
2309 if (err == 0 && rt->dst.error)
2310 err = -rt->dst.error;
2311 } else {
2312 rt = ip_route_output_key(net, &fl4);
2313
2314 err = 0;
2315 if (IS_ERR(rt))
2316 err = PTR_ERR(rt);
2317 }
2318
2319 if (err)
2320 goto errout_free;
2321
2322 skb_dst_set(skb, &rt->dst);
2323 if (rtm->rtm_flags & RTM_F_NOTIFY)
2324 rt->rt_flags |= RTCF_NOTIFY;
2325
2326 err = rt_fill_info(net, dst, src, &fl4, skb,
2327 NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2328 RTM_NEWROUTE, 0, 0);
2329 if (err <= 0)
2330 goto errout_free;
2331
2332 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2333 errout:
2334 return err;
2335
2336 errout_free:
2337 kfree_skb(skb);
2338 goto errout;
2339 }
2340
2341 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2342 {
2343 return skb->len;
2344 }
2345
2346 void ip_rt_multicast_event(struct in_device *in_dev)
2347 {
2348 rt_cache_flush(dev_net(in_dev->dev), 0);
2349 }
2350
2351 #ifdef CONFIG_SYSCTL
2352 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
2353 void __user *buffer,
2354 size_t *lenp, loff_t *ppos)
2355 {
2356 if (write) {
2357 int flush_delay;
2358 ctl_table ctl;
2359 struct net *net;
2360
2361 memcpy(&ctl, __ctl, sizeof(ctl));
2362 ctl.data = &flush_delay;
2363 proc_dointvec(&ctl, write, buffer, lenp, ppos);
2364
2365 net = (struct net *)__ctl->extra1;
2366 rt_cache_flush(net, flush_delay);
2367 return 0;
2368 }
2369
2370 return -EINVAL;
2371 }
2372
2373 static ctl_table ipv4_route_table[] = {
2374 {
2375 .procname = "gc_thresh",
2376 .data = &ipv4_dst_ops.gc_thresh,
2377 .maxlen = sizeof(int),
2378 .mode = 0644,
2379 .proc_handler = proc_dointvec,
2380 },
2381 {
2382 .procname = "max_size",
2383 .data = &ip_rt_max_size,
2384 .maxlen = sizeof(int),
2385 .mode = 0644,
2386 .proc_handler = proc_dointvec,
2387 },
2388 {
2389 /* Deprecated. Use gc_min_interval_ms */
2390
2391 .procname = "gc_min_interval",
2392 .data = &ip_rt_gc_min_interval,
2393 .maxlen = sizeof(int),
2394 .mode = 0644,
2395 .proc_handler = proc_dointvec_jiffies,
2396 },
2397 {
2398 .procname = "gc_min_interval_ms",
2399 .data = &ip_rt_gc_min_interval,
2400 .maxlen = sizeof(int),
2401 .mode = 0644,
2402 .proc_handler = proc_dointvec_ms_jiffies,
2403 },
2404 {
2405 .procname = "gc_timeout",
2406 .data = &ip_rt_gc_timeout,
2407 .maxlen = sizeof(int),
2408 .mode = 0644,
2409 .proc_handler = proc_dointvec_jiffies,
2410 },
2411 {
2412 .procname = "gc_interval",
2413 .data = &ip_rt_gc_interval,
2414 .maxlen = sizeof(int),
2415 .mode = 0644,
2416 .proc_handler = proc_dointvec_jiffies,
2417 },
2418 {
2419 .procname = "redirect_load",
2420 .data = &ip_rt_redirect_load,
2421 .maxlen = sizeof(int),
2422 .mode = 0644,
2423 .proc_handler = proc_dointvec,
2424 },
2425 {
2426 .procname = "redirect_number",
2427 .data = &ip_rt_redirect_number,
2428 .maxlen = sizeof(int),
2429 .mode = 0644,
2430 .proc_handler = proc_dointvec,
2431 },
2432 {
2433 .procname = "redirect_silence",
2434 .data = &ip_rt_redirect_silence,
2435 .maxlen = sizeof(int),
2436 .mode = 0644,
2437 .proc_handler = proc_dointvec,
2438 },
2439 {
2440 .procname = "error_cost",
2441 .data = &ip_rt_error_cost,
2442 .maxlen = sizeof(int),
2443 .mode = 0644,
2444 .proc_handler = proc_dointvec,
2445 },
2446 {
2447 .procname = "error_burst",
2448 .data = &ip_rt_error_burst,
2449 .maxlen = sizeof(int),
2450 .mode = 0644,
2451 .proc_handler = proc_dointvec,
2452 },
2453 {
2454 .procname = "gc_elasticity",
2455 .data = &ip_rt_gc_elasticity,
2456 .maxlen = sizeof(int),
2457 .mode = 0644,
2458 .proc_handler = proc_dointvec,
2459 },
2460 {
2461 .procname = "mtu_expires",
2462 .data = &ip_rt_mtu_expires,
2463 .maxlen = sizeof(int),
2464 .mode = 0644,
2465 .proc_handler = proc_dointvec_jiffies,
2466 },
2467 {
2468 .procname = "min_pmtu",
2469 .data = &ip_rt_min_pmtu,
2470 .maxlen = sizeof(int),
2471 .mode = 0644,
2472 .proc_handler = proc_dointvec,
2473 },
2474 {
2475 .procname = "min_adv_mss",
2476 .data = &ip_rt_min_advmss,
2477 .maxlen = sizeof(int),
2478 .mode = 0644,
2479 .proc_handler = proc_dointvec,
2480 },
2481 { }
2482 };
2483
2484 static struct ctl_table ipv4_route_flush_table[] = {
2485 {
2486 .procname = "flush",
2487 .maxlen = sizeof(int),
2488 .mode = 0200,
2489 .proc_handler = ipv4_sysctl_rtcache_flush,
2490 },
2491 { },
2492 };
2493
2494 static __net_init int sysctl_route_net_init(struct net *net)
2495 {
2496 struct ctl_table *tbl;
2497
2498 tbl = ipv4_route_flush_table;
2499 if (!net_eq(net, &init_net)) {
2500 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2501 if (tbl == NULL)
2502 goto err_dup;
2503 }
2504 tbl[0].extra1 = net;
2505
2506 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2507 if (net->ipv4.route_hdr == NULL)
2508 goto err_reg;
2509 return 0;
2510
2511 err_reg:
2512 if (tbl != ipv4_route_flush_table)
2513 kfree(tbl);
2514 err_dup:
2515 return -ENOMEM;
2516 }
2517
2518 static __net_exit void sysctl_route_net_exit(struct net *net)
2519 {
2520 struct ctl_table *tbl;
2521
2522 tbl = net->ipv4.route_hdr->ctl_table_arg;
2523 unregister_net_sysctl_table(net->ipv4.route_hdr);
2524 BUG_ON(tbl == ipv4_route_flush_table);
2525 kfree(tbl);
2526 }
2527
2528 static __net_initdata struct pernet_operations sysctl_route_ops = {
2529 .init = sysctl_route_net_init,
2530 .exit = sysctl_route_net_exit,
2531 };
2532 #endif
2533
2534 static __net_init int rt_genid_init(struct net *net)
2535 {
2536 get_random_bytes(&net->ipv4.rt_genid,
2537 sizeof(net->ipv4.rt_genid));
2538 get_random_bytes(&net->ipv4.dev_addr_genid,
2539 sizeof(net->ipv4.dev_addr_genid));
2540 return 0;
2541 }
2542
2543 static __net_initdata struct pernet_operations rt_genid_ops = {
2544 .init = rt_genid_init,
2545 };
2546
2547 static int __net_init ipv4_inetpeer_init(struct net *net)
2548 {
2549 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2550
2551 if (!bp)
2552 return -ENOMEM;
2553 inet_peer_base_init(bp);
2554 net->ipv4.peers = bp;
2555 return 0;
2556 }
2557
2558 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2559 {
2560 struct inet_peer_base *bp = net->ipv4.peers;
2561
2562 net->ipv4.peers = NULL;
2563 inetpeer_invalidate_tree(bp);
2564 kfree(bp);
2565 }
2566
2567 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2568 .init = ipv4_inetpeer_init,
2569 .exit = ipv4_inetpeer_exit,
2570 };
2571
2572 #ifdef CONFIG_IP_ROUTE_CLASSID
2573 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2574 #endif /* CONFIG_IP_ROUTE_CLASSID */
2575
2576 int __init ip_rt_init(void)
2577 {
2578 int rc = 0;
2579
2580 #ifdef CONFIG_IP_ROUTE_CLASSID
2581 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2582 if (!ip_rt_acct)
2583 panic("IP: failed to allocate ip_rt_acct\n");
2584 #endif
2585
2586 ipv4_dst_ops.kmem_cachep =
2587 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2588 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2589
2590 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2591
2592 if (dst_entries_init(&ipv4_dst_ops) < 0)
2593 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2594
2595 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2596 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2597
2598 ipv4_dst_ops.gc_thresh = ~0;
2599 ip_rt_max_size = INT_MAX;
2600
2601 devinet_init();
2602 ip_fib_init();
2603
2604 if (ip_rt_proc_init())
2605 pr_err("Unable to create route proc files\n");
2606 #ifdef CONFIG_XFRM
2607 xfrm_init();
2608 xfrm4_init(ip_rt_max_size);
2609 #endif
2610 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2611
2612 #ifdef CONFIG_SYSCTL
2613 register_pernet_subsys(&sysctl_route_ops);
2614 #endif
2615 register_pernet_subsys(&rt_genid_ops);
2616 register_pernet_subsys(&ipv4_inetpeer_ops);
2617 return rc;
2618 }
2619
2620 #ifdef CONFIG_SYSCTL
2621 /*
2622 * We really need to sanitize the damn ipv4 init order, then all
2623 * this nonsense will go away.
2624 */
2625 void __init ip_static_sysctl_init(void)
2626 {
2627 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2628 }
2629 #endif
Linux kernel - Deliverables
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