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ipv4: Properly purge netdev references on uncached routes.
[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/bootmem.h>
74 #include <linux/string.h>
75 #include <linux/socket.h>
76 #include <linux/sockios.h>
77 #include <linux/errno.h>
78 #include <linux/in.h>
79 #include <linux/inet.h>
80 #include <linux/netdevice.h>
81 #include <linux/proc_fs.h>
82 #include <linux/init.h>
83 #include <linux/workqueue.h>
84 #include <linux/skbuff.h>
85 #include <linux/inetdevice.h>
86 #include <linux/igmp.h>
87 #include <linux/pkt_sched.h>
88 #include <linux/mroute.h>
89 #include <linux/netfilter_ipv4.h>
90 #include <linux/random.h>
91 #include <linux/jhash.h>
92 #include <linux/rcupdate.h>
93 #include <linux/times.h>
94 #include <linux/slab.h>
95 #include <linux/prefetch.h>
96 #include <net/dst.h>
97 #include <net/net_namespace.h>
98 #include <net/protocol.h>
99 #include <net/ip.h>
100 #include <net/route.h>
101 #include <net/inetpeer.h>
102 #include <net/sock.h>
103 #include <net/ip_fib.h>
104 #include <net/arp.h>
105 #include <net/tcp.h>
106 #include <net/icmp.h>
107 #include <net/xfrm.h>
108 #include <net/netevent.h>
109 #include <net/rtnetlink.h>
110 #ifdef CONFIG_SYSCTL
111 #include <linux/sysctl.h>
112 #include <linux/kmemleak.h>
113 #endif
114 #include <net/secure_seq.h>
115
116 #define RT_FL_TOS(oldflp4) \
117 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
118
119 #define IP_MAX_MTU 0xFFF0
120
121 #define RT_GC_TIMEOUT (300*HZ)
122
123 static int ip_rt_max_size;
124 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
125 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
126 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
127 static int ip_rt_redirect_number __read_mostly = 9;
128 static int ip_rt_redirect_load __read_mostly = HZ / 50;
129 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
130 static int ip_rt_error_cost __read_mostly = HZ;
131 static int ip_rt_error_burst __read_mostly = 5 * HZ;
132 static int ip_rt_gc_elasticity __read_mostly = 8;
133 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
134 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
135 static int ip_rt_min_advmss __read_mostly = 256;
136
137 /*
138 * Interface to generic destination cache.
139 */
140
141 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
142 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
143 static unsigned int ipv4_mtu(const struct dst_entry *dst);
144 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
145 static void ipv4_link_failure(struct sk_buff *skb);
146 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
147 struct sk_buff *skb, u32 mtu);
148 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
149 struct sk_buff *skb);
150 static void ipv4_dst_destroy(struct dst_entry *dst);
151
152 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
153 int how)
154 {
155 }
156
157 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
158 {
159 WARN_ON(1);
160 return NULL;
161 }
162
163 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
164 struct sk_buff *skb,
165 const void *daddr);
166
167 static struct dst_ops ipv4_dst_ops = {
168 .family = AF_INET,
169 .protocol = cpu_to_be16(ETH_P_IP),
170 .check = ipv4_dst_check,
171 .default_advmss = ipv4_default_advmss,
172 .mtu = ipv4_mtu,
173 .cow_metrics = ipv4_cow_metrics,
174 .destroy = ipv4_dst_destroy,
175 .ifdown = ipv4_dst_ifdown,
176 .negative_advice = ipv4_negative_advice,
177 .link_failure = ipv4_link_failure,
178 .update_pmtu = ip_rt_update_pmtu,
179 .redirect = ip_do_redirect,
180 .local_out = __ip_local_out,
181 .neigh_lookup = ipv4_neigh_lookup,
182 };
183
184 #define ECN_OR_COST(class) TC_PRIO_##class
185
186 const __u8 ip_tos2prio[16] = {
187 TC_PRIO_BESTEFFORT,
188 ECN_OR_COST(BESTEFFORT),
189 TC_PRIO_BESTEFFORT,
190 ECN_OR_COST(BESTEFFORT),
191 TC_PRIO_BULK,
192 ECN_OR_COST(BULK),
193 TC_PRIO_BULK,
194 ECN_OR_COST(BULK),
195 TC_PRIO_INTERACTIVE,
196 ECN_OR_COST(INTERACTIVE),
197 TC_PRIO_INTERACTIVE,
198 ECN_OR_COST(INTERACTIVE),
199 TC_PRIO_INTERACTIVE_BULK,
200 ECN_OR_COST(INTERACTIVE_BULK),
201 TC_PRIO_INTERACTIVE_BULK,
202 ECN_OR_COST(INTERACTIVE_BULK)
203 };
204 EXPORT_SYMBOL(ip_tos2prio);
205
206 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
207 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
208
209 static inline int rt_genid(struct net *net)
210 {
211 return atomic_read(&net->ipv4.rt_genid);
212 }
213
214 #ifdef CONFIG_PROC_FS
215 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
216 {
217 if (*pos)
218 return NULL;
219 return SEQ_START_TOKEN;
220 }
221
222 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
223 {
224 ++*pos;
225 return NULL;
226 }
227
228 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
229 {
230 }
231
232 static int rt_cache_seq_show(struct seq_file *seq, void *v)
233 {
234 if (v == SEQ_START_TOKEN)
235 seq_printf(seq, "%-127s\n",
236 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
237 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
238 "HHUptod\tSpecDst");
239 return 0;
240 }
241
242 static const struct seq_operations rt_cache_seq_ops = {
243 .start = rt_cache_seq_start,
244 .next = rt_cache_seq_next,
245 .stop = rt_cache_seq_stop,
246 .show = rt_cache_seq_show,
247 };
248
249 static int rt_cache_seq_open(struct inode *inode, struct file *file)
250 {
251 return seq_open(file, &rt_cache_seq_ops);
252 }
253
254 static const struct file_operations rt_cache_seq_fops = {
255 .owner = THIS_MODULE,
256 .open = rt_cache_seq_open,
257 .read = seq_read,
258 .llseek = seq_lseek,
259 .release = seq_release,
260 };
261
262
263 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
264 {
265 int cpu;
266
267 if (*pos == 0)
268 return SEQ_START_TOKEN;
269
270 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
271 if (!cpu_possible(cpu))
272 continue;
273 *pos = cpu+1;
274 return &per_cpu(rt_cache_stat, cpu);
275 }
276 return NULL;
277 }
278
279 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
280 {
281 int cpu;
282
283 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
284 if (!cpu_possible(cpu))
285 continue;
286 *pos = cpu+1;
287 return &per_cpu(rt_cache_stat, cpu);
288 }
289 return NULL;
290
291 }
292
293 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
294 {
295
296 }
297
298 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
299 {
300 struct rt_cache_stat *st = v;
301
302 if (v == SEQ_START_TOKEN) {
303 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");
304 return 0;
305 }
306
307 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
308 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
309 dst_entries_get_slow(&ipv4_dst_ops),
310 st->in_hit,
311 st->in_slow_tot,
312 st->in_slow_mc,
313 st->in_no_route,
314 st->in_brd,
315 st->in_martian_dst,
316 st->in_martian_src,
317
318 st->out_hit,
319 st->out_slow_tot,
320 st->out_slow_mc,
321
322 st->gc_total,
323 st->gc_ignored,
324 st->gc_goal_miss,
325 st->gc_dst_overflow,
326 st->in_hlist_search,
327 st->out_hlist_search
328 );
329 return 0;
330 }
331
332 static const struct seq_operations rt_cpu_seq_ops = {
333 .start = rt_cpu_seq_start,
334 .next = rt_cpu_seq_next,
335 .stop = rt_cpu_seq_stop,
336 .show = rt_cpu_seq_show,
337 };
338
339
340 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
341 {
342 return seq_open(file, &rt_cpu_seq_ops);
343 }
344
345 static const struct file_operations rt_cpu_seq_fops = {
346 .owner = THIS_MODULE,
347 .open = rt_cpu_seq_open,
348 .read = seq_read,
349 .llseek = seq_lseek,
350 .release = seq_release,
351 };
352
353 #ifdef CONFIG_IP_ROUTE_CLASSID
354 static int rt_acct_proc_show(struct seq_file *m, void *v)
355 {
356 struct ip_rt_acct *dst, *src;
357 unsigned int i, j;
358
359 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
360 if (!dst)
361 return -ENOMEM;
362
363 for_each_possible_cpu(i) {
364 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
365 for (j = 0; j < 256; j++) {
366 dst[j].o_bytes += src[j].o_bytes;
367 dst[j].o_packets += src[j].o_packets;
368 dst[j].i_bytes += src[j].i_bytes;
369 dst[j].i_packets += src[j].i_packets;
370 }
371 }
372
373 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
374 kfree(dst);
375 return 0;
376 }
377
378 static int rt_acct_proc_open(struct inode *inode, struct file *file)
379 {
380 return single_open(file, rt_acct_proc_show, NULL);
381 }
382
383 static const struct file_operations rt_acct_proc_fops = {
384 .owner = THIS_MODULE,
385 .open = rt_acct_proc_open,
386 .read = seq_read,
387 .llseek = seq_lseek,
388 .release = single_release,
389 };
390 #endif
391
392 static int __net_init ip_rt_do_proc_init(struct net *net)
393 {
394 struct proc_dir_entry *pde;
395
396 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
397 &rt_cache_seq_fops);
398 if (!pde)
399 goto err1;
400
401 pde = proc_create("rt_cache", S_IRUGO,
402 net->proc_net_stat, &rt_cpu_seq_fops);
403 if (!pde)
404 goto err2;
405
406 #ifdef CONFIG_IP_ROUTE_CLASSID
407 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
408 if (!pde)
409 goto err3;
410 #endif
411 return 0;
412
413 #ifdef CONFIG_IP_ROUTE_CLASSID
414 err3:
415 remove_proc_entry("rt_cache", net->proc_net_stat);
416 #endif
417 err2:
418 remove_proc_entry("rt_cache", net->proc_net);
419 err1:
420 return -ENOMEM;
421 }
422
423 static void __net_exit ip_rt_do_proc_exit(struct net *net)
424 {
425 remove_proc_entry("rt_cache", net->proc_net_stat);
426 remove_proc_entry("rt_cache", net->proc_net);
427 #ifdef CONFIG_IP_ROUTE_CLASSID
428 remove_proc_entry("rt_acct", net->proc_net);
429 #endif
430 }
431
432 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
433 .init = ip_rt_do_proc_init,
434 .exit = ip_rt_do_proc_exit,
435 };
436
437 static int __init ip_rt_proc_init(void)
438 {
439 return register_pernet_subsys(&ip_rt_proc_ops);
440 }
441
442 #else
443 static inline int ip_rt_proc_init(void)
444 {
445 return 0;
446 }
447 #endif /* CONFIG_PROC_FS */
448
449 static inline bool rt_is_expired(const struct rtable *rth)
450 {
451 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
452 }
453
454 /*
455 * Perturbation of rt_genid by a small quantity [1..256]
456 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
457 * many times (2^24) without giving recent rt_genid.
458 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
459 */
460 static void rt_cache_invalidate(struct net *net)
461 {
462 unsigned char shuffle;
463
464 get_random_bytes(&shuffle, sizeof(shuffle));
465 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
466 }
467
468 /*
469 * delay < 0 : invalidate cache (fast : entries will be deleted later)
470 * delay >= 0 : invalidate & flush cache (can be long)
471 */
472 void rt_cache_flush(struct net *net, int delay)
473 {
474 rt_cache_invalidate(net);
475 }
476
477 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
478 struct sk_buff *skb,
479 const void *daddr)
480 {
481 struct net_device *dev = dst->dev;
482 const __be32 *pkey = daddr;
483 const struct rtable *rt;
484 struct neighbour *n;
485
486 rt = (const struct rtable *) dst;
487 if (rt->rt_gateway)
488 pkey = (const __be32 *) &rt->rt_gateway;
489 else if (skb)
490 pkey = &ip_hdr(skb)->daddr;
491
492 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
493 if (n)
494 return n;
495 return neigh_create(&arp_tbl, pkey, dev);
496 }
497
498 /*
499 * Peer allocation may fail only in serious out-of-memory conditions. However
500 * we still can generate some output.
501 * Random ID selection looks a bit dangerous because we have no chances to
502 * select ID being unique in a reasonable period of time.
503 * But broken packet identifier may be better than no packet at all.
504 */
505 static void ip_select_fb_ident(struct iphdr *iph)
506 {
507 static DEFINE_SPINLOCK(ip_fb_id_lock);
508 static u32 ip_fallback_id;
509 u32 salt;
510
511 spin_lock_bh(&ip_fb_id_lock);
512 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
513 iph->id = htons(salt & 0xFFFF);
514 ip_fallback_id = salt;
515 spin_unlock_bh(&ip_fb_id_lock);
516 }
517
518 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
519 {
520 struct net *net = dev_net(dst->dev);
521 struct inet_peer *peer;
522
523 peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1);
524 if (peer) {
525 iph->id = htons(inet_getid(peer, more));
526 inet_putpeer(peer);
527 return;
528 }
529
530 ip_select_fb_ident(iph);
531 }
532 EXPORT_SYMBOL(__ip_select_ident);
533
534 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
535 const struct iphdr *iph,
536 int oif, u8 tos,
537 u8 prot, u32 mark, int flow_flags)
538 {
539 if (sk) {
540 const struct inet_sock *inet = inet_sk(sk);
541
542 oif = sk->sk_bound_dev_if;
543 mark = sk->sk_mark;
544 tos = RT_CONN_FLAGS(sk);
545 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
546 }
547 flowi4_init_output(fl4, oif, mark, tos,
548 RT_SCOPE_UNIVERSE, prot,
549 flow_flags,
550 iph->daddr, iph->saddr, 0, 0);
551 }
552
553 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
554 const struct sock *sk)
555 {
556 const struct iphdr *iph = ip_hdr(skb);
557 int oif = skb->dev->ifindex;
558 u8 tos = RT_TOS(iph->tos);
559 u8 prot = iph->protocol;
560 u32 mark = skb->mark;
561
562 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
563 }
564
565 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
566 {
567 const struct inet_sock *inet = inet_sk(sk);
568 const struct ip_options_rcu *inet_opt;
569 __be32 daddr = inet->inet_daddr;
570
571 rcu_read_lock();
572 inet_opt = rcu_dereference(inet->inet_opt);
573 if (inet_opt && inet_opt->opt.srr)
574 daddr = inet_opt->opt.faddr;
575 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
576 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
577 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
578 inet_sk_flowi_flags(sk),
579 daddr, inet->inet_saddr, 0, 0);
580 rcu_read_unlock();
581 }
582
583 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
584 const struct sk_buff *skb)
585 {
586 if (skb)
587 build_skb_flow_key(fl4, skb, sk);
588 else
589 build_sk_flow_key(fl4, sk);
590 }
591
592 static inline void rt_free(struct rtable *rt)
593 {
594 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
595 }
596
597 static DEFINE_SPINLOCK(fnhe_lock);
598
599 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
600 {
601 struct fib_nh_exception *fnhe, *oldest;
602 struct rtable *orig;
603
604 oldest = rcu_dereference(hash->chain);
605 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
606 fnhe = rcu_dereference(fnhe->fnhe_next)) {
607 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
608 oldest = fnhe;
609 }
610 orig = rcu_dereference(oldest->fnhe_rth);
611 if (orig) {
612 RCU_INIT_POINTER(oldest->fnhe_rth, NULL);
613 rt_free(orig);
614 }
615 return oldest;
616 }
617
618 static inline u32 fnhe_hashfun(__be32 daddr)
619 {
620 u32 hval;
621
622 hval = (__force u32) daddr;
623 hval ^= (hval >> 11) ^ (hval >> 22);
624
625 return hval & (FNHE_HASH_SIZE - 1);
626 }
627
628 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
629 u32 pmtu, unsigned long expires)
630 {
631 struct fnhe_hash_bucket *hash;
632 struct fib_nh_exception *fnhe;
633 int depth;
634 u32 hval = fnhe_hashfun(daddr);
635
636 spin_lock_bh(&fnhe_lock);
637
638 hash = nh->nh_exceptions;
639 if (!hash) {
640 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
641 if (!hash)
642 goto out_unlock;
643 nh->nh_exceptions = hash;
644 }
645
646 hash += hval;
647
648 depth = 0;
649 for (fnhe = rcu_dereference(hash->chain); fnhe;
650 fnhe = rcu_dereference(fnhe->fnhe_next)) {
651 if (fnhe->fnhe_daddr == daddr)
652 break;
653 depth++;
654 }
655
656 if (fnhe) {
657 if (gw)
658 fnhe->fnhe_gw = gw;
659 if (pmtu) {
660 fnhe->fnhe_pmtu = pmtu;
661 fnhe->fnhe_expires = expires;
662 }
663 } else {
664 if (depth > FNHE_RECLAIM_DEPTH)
665 fnhe = fnhe_oldest(hash);
666 else {
667 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
668 if (!fnhe)
669 goto out_unlock;
670
671 fnhe->fnhe_next = hash->chain;
672 rcu_assign_pointer(hash->chain, fnhe);
673 }
674 fnhe->fnhe_daddr = daddr;
675 fnhe->fnhe_gw = gw;
676 fnhe->fnhe_pmtu = pmtu;
677 fnhe->fnhe_expires = expires;
678 }
679
680 fnhe->fnhe_stamp = jiffies;
681
682 out_unlock:
683 spin_unlock_bh(&fnhe_lock);
684 return;
685 }
686
687 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
688 bool kill_route)
689 {
690 __be32 new_gw = icmp_hdr(skb)->un.gateway;
691 __be32 old_gw = ip_hdr(skb)->saddr;
692 struct net_device *dev = skb->dev;
693 struct in_device *in_dev;
694 struct fib_result res;
695 struct neighbour *n;
696 struct net *net;
697
698 switch (icmp_hdr(skb)->code & 7) {
699 case ICMP_REDIR_NET:
700 case ICMP_REDIR_NETTOS:
701 case ICMP_REDIR_HOST:
702 case ICMP_REDIR_HOSTTOS:
703 break;
704
705 default:
706 return;
707 }
708
709 if (rt->rt_gateway != old_gw)
710 return;
711
712 in_dev = __in_dev_get_rcu(dev);
713 if (!in_dev)
714 return;
715
716 net = dev_net(dev);
717 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
718 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
719 ipv4_is_zeronet(new_gw))
720 goto reject_redirect;
721
722 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
723 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
724 goto reject_redirect;
725 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
726 goto reject_redirect;
727 } else {
728 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
729 goto reject_redirect;
730 }
731
732 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
733 if (n) {
734 if (!(n->nud_state & NUD_VALID)) {
735 neigh_event_send(n, NULL);
736 } else {
737 if (fib_lookup(net, fl4, &res) == 0) {
738 struct fib_nh *nh = &FIB_RES_NH(res);
739
740 update_or_create_fnhe(nh, fl4->daddr, new_gw,
741 0, 0);
742 }
743 if (kill_route)
744 rt->dst.obsolete = DST_OBSOLETE_KILL;
745 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
746 }
747 neigh_release(n);
748 }
749 return;
750
751 reject_redirect:
752 #ifdef CONFIG_IP_ROUTE_VERBOSE
753 if (IN_DEV_LOG_MARTIANS(in_dev)) {
754 const struct iphdr *iph = (const struct iphdr *) skb->data;
755 __be32 daddr = iph->daddr;
756 __be32 saddr = iph->saddr;
757
758 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
759 " Advised path = %pI4 -> %pI4\n",
760 &old_gw, dev->name, &new_gw,
761 &saddr, &daddr);
762 }
763 #endif
764 ;
765 }
766
767 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
768 {
769 struct rtable *rt;
770 struct flowi4 fl4;
771
772 rt = (struct rtable *) dst;
773
774 ip_rt_build_flow_key(&fl4, sk, skb);
775 __ip_do_redirect(rt, skb, &fl4, true);
776 }
777
778 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
779 {
780 struct rtable *rt = (struct rtable *)dst;
781 struct dst_entry *ret = dst;
782
783 if (rt) {
784 if (dst->obsolete > 0) {
785 ip_rt_put(rt);
786 ret = NULL;
787 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
788 rt->dst.expires) {
789 ip_rt_put(rt);
790 ret = NULL;
791 }
792 }
793 return ret;
794 }
795
796 /*
797 * Algorithm:
798 * 1. The first ip_rt_redirect_number redirects are sent
799 * with exponential backoff, then we stop sending them at all,
800 * assuming that the host ignores our redirects.
801 * 2. If we did not see packets requiring redirects
802 * during ip_rt_redirect_silence, we assume that the host
803 * forgot redirected route and start to send redirects again.
804 *
805 * This algorithm is much cheaper and more intelligent than dumb load limiting
806 * in icmp.c.
807 *
808 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
809 * and "frag. need" (breaks PMTU discovery) in icmp.c.
810 */
811
812 void ip_rt_send_redirect(struct sk_buff *skb)
813 {
814 struct rtable *rt = skb_rtable(skb);
815 struct in_device *in_dev;
816 struct inet_peer *peer;
817 struct net *net;
818 int log_martians;
819
820 rcu_read_lock();
821 in_dev = __in_dev_get_rcu(rt->dst.dev);
822 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
823 rcu_read_unlock();
824 return;
825 }
826 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
827 rcu_read_unlock();
828
829 net = dev_net(rt->dst.dev);
830 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
831 if (!peer) {
832 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
833 return;
834 }
835
836 /* No redirected packets during ip_rt_redirect_silence;
837 * reset the algorithm.
838 */
839 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
840 peer->rate_tokens = 0;
841
842 /* Too many ignored redirects; do not send anything
843 * set dst.rate_last to the last seen redirected packet.
844 */
845 if (peer->rate_tokens >= ip_rt_redirect_number) {
846 peer->rate_last = jiffies;
847 goto out_put_peer;
848 }
849
850 /* Check for load limit; set rate_last to the latest sent
851 * redirect.
852 */
853 if (peer->rate_tokens == 0 ||
854 time_after(jiffies,
855 (peer->rate_last +
856 (ip_rt_redirect_load << peer->rate_tokens)))) {
857 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
858 peer->rate_last = jiffies;
859 ++peer->rate_tokens;
860 #ifdef CONFIG_IP_ROUTE_VERBOSE
861 if (log_martians &&
862 peer->rate_tokens == ip_rt_redirect_number)
863 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
864 &ip_hdr(skb)->saddr, inet_iif(skb),
865 &ip_hdr(skb)->daddr, &rt->rt_gateway);
866 #endif
867 }
868 out_put_peer:
869 inet_putpeer(peer);
870 }
871
872 static int ip_error(struct sk_buff *skb)
873 {
874 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
875 struct rtable *rt = skb_rtable(skb);
876 struct inet_peer *peer;
877 unsigned long now;
878 struct net *net;
879 bool send;
880 int code;
881
882 net = dev_net(rt->dst.dev);
883 if (!IN_DEV_FORWARD(in_dev)) {
884 switch (rt->dst.error) {
885 case EHOSTUNREACH:
886 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
887 break;
888
889 case ENETUNREACH:
890 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
891 break;
892 }
893 goto out;
894 }
895
896 switch (rt->dst.error) {
897 case EINVAL:
898 default:
899 goto out;
900 case EHOSTUNREACH:
901 code = ICMP_HOST_UNREACH;
902 break;
903 case ENETUNREACH:
904 code = ICMP_NET_UNREACH;
905 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
906 break;
907 case EACCES:
908 code = ICMP_PKT_FILTERED;
909 break;
910 }
911
912 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
913
914 send = true;
915 if (peer) {
916 now = jiffies;
917 peer->rate_tokens += now - peer->rate_last;
918 if (peer->rate_tokens > ip_rt_error_burst)
919 peer->rate_tokens = ip_rt_error_burst;
920 peer->rate_last = now;
921 if (peer->rate_tokens >= ip_rt_error_cost)
922 peer->rate_tokens -= ip_rt_error_cost;
923 else
924 send = false;
925 inet_putpeer(peer);
926 }
927 if (send)
928 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
929
930 out: kfree_skb(skb);
931 return 0;
932 }
933
934 static u32 __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
935 {
936 struct fib_result res;
937
938 if (mtu < ip_rt_min_pmtu)
939 mtu = ip_rt_min_pmtu;
940
941 if (fib_lookup(dev_net(rt->dst.dev), fl4, &res) == 0) {
942 struct fib_nh *nh = &FIB_RES_NH(res);
943
944 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
945 jiffies + ip_rt_mtu_expires);
946 }
947 return mtu;
948 }
949
950 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
951 struct sk_buff *skb, u32 mtu)
952 {
953 struct rtable *rt = (struct rtable *) dst;
954 struct flowi4 fl4;
955
956 ip_rt_build_flow_key(&fl4, sk, skb);
957 mtu = __ip_rt_update_pmtu(rt, &fl4, mtu);
958
959 if (!rt->rt_pmtu) {
960 dst->obsolete = DST_OBSOLETE_KILL;
961 } else {
962 rt->rt_pmtu = mtu;
963 dst_set_expires(&rt->dst, ip_rt_mtu_expires);
964 }
965 }
966
967 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
968 int oif, u32 mark, u8 protocol, int flow_flags)
969 {
970 const struct iphdr *iph = (const struct iphdr *) skb->data;
971 struct flowi4 fl4;
972 struct rtable *rt;
973
974 __build_flow_key(&fl4, NULL, iph, oif,
975 RT_TOS(iph->tos), protocol, mark, flow_flags);
976 rt = __ip_route_output_key(net, &fl4);
977 if (!IS_ERR(rt)) {
978 __ip_rt_update_pmtu(rt, &fl4, mtu);
979 ip_rt_put(rt);
980 }
981 }
982 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
983
984 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
985 {
986 const struct iphdr *iph = (const struct iphdr *) skb->data;
987 struct flowi4 fl4;
988 struct rtable *rt;
989
990 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
991 rt = __ip_route_output_key(sock_net(sk), &fl4);
992 if (!IS_ERR(rt)) {
993 __ip_rt_update_pmtu(rt, &fl4, mtu);
994 ip_rt_put(rt);
995 }
996 }
997 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
998
999 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1000 int oif, u32 mark, u8 protocol, int flow_flags)
1001 {
1002 const struct iphdr *iph = (const struct iphdr *) skb->data;
1003 struct flowi4 fl4;
1004 struct rtable *rt;
1005
1006 __build_flow_key(&fl4, NULL, iph, oif,
1007 RT_TOS(iph->tos), protocol, mark, flow_flags);
1008 rt = __ip_route_output_key(net, &fl4);
1009 if (!IS_ERR(rt)) {
1010 __ip_do_redirect(rt, skb, &fl4, false);
1011 ip_rt_put(rt);
1012 }
1013 }
1014 EXPORT_SYMBOL_GPL(ipv4_redirect);
1015
1016 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1017 {
1018 const struct iphdr *iph = (const struct iphdr *) skb->data;
1019 struct flowi4 fl4;
1020 struct rtable *rt;
1021
1022 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1023 rt = __ip_route_output_key(sock_net(sk), &fl4);
1024 if (!IS_ERR(rt)) {
1025 __ip_do_redirect(rt, skb, &fl4, false);
1026 ip_rt_put(rt);
1027 }
1028 }
1029 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1030
1031 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1032 {
1033 struct rtable *rt = (struct rtable *) dst;
1034
1035 /* All IPV4 dsts are created with ->obsolete set to the value
1036 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1037 * into this function always.
1038 *
1039 * When a PMTU/redirect information update invalidates a
1040 * route, this is indicated by setting obsolete to
1041 * DST_OBSOLETE_KILL.
1042 */
1043 if (dst->obsolete == DST_OBSOLETE_KILL || rt_is_expired(rt))
1044 return NULL;
1045 return dst;
1046 }
1047
1048 static void ipv4_link_failure(struct sk_buff *skb)
1049 {
1050 struct rtable *rt;
1051
1052 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1053
1054 rt = skb_rtable(skb);
1055 if (rt)
1056 dst_set_expires(&rt->dst, 0);
1057 }
1058
1059 static int ip_rt_bug(struct sk_buff *skb)
1060 {
1061 pr_debug("%s: %pI4 -> %pI4, %s\n",
1062 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1063 skb->dev ? skb->dev->name : "?");
1064 kfree_skb(skb);
1065 WARN_ON(1);
1066 return 0;
1067 }
1068
1069 /*
1070 We do not cache source address of outgoing interface,
1071 because it is used only by IP RR, TS and SRR options,
1072 so that it out of fast path.
1073
1074 BTW remember: "addr" is allowed to be not aligned
1075 in IP options!
1076 */
1077
1078 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1079 {
1080 __be32 src;
1081
1082 if (rt_is_output_route(rt))
1083 src = ip_hdr(skb)->saddr;
1084 else {
1085 struct fib_result res;
1086 struct flowi4 fl4;
1087 struct iphdr *iph;
1088
1089 iph = ip_hdr(skb);
1090
1091 memset(&fl4, 0, sizeof(fl4));
1092 fl4.daddr = iph->daddr;
1093 fl4.saddr = iph->saddr;
1094 fl4.flowi4_tos = RT_TOS(iph->tos);
1095 fl4.flowi4_oif = rt->dst.dev->ifindex;
1096 fl4.flowi4_iif = skb->dev->ifindex;
1097 fl4.flowi4_mark = skb->mark;
1098
1099 rcu_read_lock();
1100 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1101 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1102 else
1103 src = inet_select_addr(rt->dst.dev,
1104 rt_nexthop(rt, iph->daddr),
1105 RT_SCOPE_UNIVERSE);
1106 rcu_read_unlock();
1107 }
1108 memcpy(addr, &src, 4);
1109 }
1110
1111 #ifdef CONFIG_IP_ROUTE_CLASSID
1112 static void set_class_tag(struct rtable *rt, u32 tag)
1113 {
1114 if (!(rt->dst.tclassid & 0xFFFF))
1115 rt->dst.tclassid |= tag & 0xFFFF;
1116 if (!(rt->dst.tclassid & 0xFFFF0000))
1117 rt->dst.tclassid |= tag & 0xFFFF0000;
1118 }
1119 #endif
1120
1121 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1122 {
1123 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1124
1125 if (advmss == 0) {
1126 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1127 ip_rt_min_advmss);
1128 if (advmss > 65535 - 40)
1129 advmss = 65535 - 40;
1130 }
1131 return advmss;
1132 }
1133
1134 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1135 {
1136 const struct rtable *rt = (const struct rtable *) dst;
1137 unsigned int mtu = rt->rt_pmtu;
1138
1139 if (mtu && time_after_eq(jiffies, rt->dst.expires))
1140 mtu = 0;
1141
1142 if (!mtu)
1143 mtu = dst_metric_raw(dst, RTAX_MTU);
1144
1145 if (mtu && rt_is_output_route(rt))
1146 return mtu;
1147
1148 mtu = dst->dev->mtu;
1149
1150 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1151 if (rt->rt_gateway && mtu > 576)
1152 mtu = 576;
1153 }
1154
1155 if (mtu > IP_MAX_MTU)
1156 mtu = IP_MAX_MTU;
1157
1158 return mtu;
1159 }
1160
1161 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1162 {
1163 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1164 struct fib_nh_exception *fnhe;
1165 u32 hval;
1166
1167 if (!hash)
1168 return NULL;
1169
1170 hval = fnhe_hashfun(daddr);
1171
1172 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1173 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1174 if (fnhe->fnhe_daddr == daddr)
1175 return fnhe;
1176 }
1177 return NULL;
1178 }
1179
1180 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1181 __be32 daddr)
1182 {
1183 bool ret = false;
1184
1185 spin_lock_bh(&fnhe_lock);
1186
1187 if (daddr == fnhe->fnhe_daddr) {
1188 struct rtable *orig;
1189
1190 if (fnhe->fnhe_pmtu) {
1191 unsigned long expires = fnhe->fnhe_expires;
1192 unsigned long diff = expires - jiffies;
1193
1194 if (time_before(jiffies, expires)) {
1195 rt->rt_pmtu = fnhe->fnhe_pmtu;
1196 dst_set_expires(&rt->dst, diff);
1197 }
1198 }
1199 if (fnhe->fnhe_gw) {
1200 rt->rt_flags |= RTCF_REDIRECTED;
1201 rt->rt_gateway = fnhe->fnhe_gw;
1202 }
1203
1204 orig = rcu_dereference(fnhe->fnhe_rth);
1205 rcu_assign_pointer(fnhe->fnhe_rth, rt);
1206 if (orig)
1207 rt_free(orig);
1208
1209 fnhe->fnhe_stamp = jiffies;
1210 ret = true;
1211 } else {
1212 /* Routes we intend to cache in nexthop exception have
1213 * the DST_NOCACHE bit clear. However, if we are
1214 * unsuccessful at storing this route into the cache
1215 * we really need to set it.
1216 */
1217 rt->dst.flags |= DST_NOCACHE;
1218 }
1219 spin_unlock_bh(&fnhe_lock);
1220
1221 return ret;
1222 }
1223
1224 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1225 {
1226 struct rtable *orig, *prev, **p;
1227 bool ret = true;
1228
1229 if (rt_is_input_route(rt)) {
1230 p = (struct rtable **)&nh->nh_rth_input;
1231 } else {
1232 if (!nh->nh_pcpu_rth_output)
1233 goto nocache;
1234 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1235 }
1236 orig = *p;
1237
1238 prev = cmpxchg(p, orig, rt);
1239 if (prev == orig) {
1240 if (orig)
1241 rt_free(orig);
1242 } else {
1243 /* Routes we intend to cache in the FIB nexthop have
1244 * the DST_NOCACHE bit clear. However, if we are
1245 * unsuccessful at storing this route into the cache
1246 * we really need to set it.
1247 */
1248 nocache:
1249 rt->dst.flags |= DST_NOCACHE;
1250 ret = false;
1251 }
1252
1253 return ret;
1254 }
1255
1256 static DEFINE_SPINLOCK(rt_uncached_lock);
1257 static LIST_HEAD(rt_uncached_list);
1258
1259 static void rt_add_uncached_list(struct rtable *rt)
1260 {
1261 spin_lock_bh(&rt_uncached_lock);
1262 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1263 spin_unlock_bh(&rt_uncached_lock);
1264 }
1265
1266 static void ipv4_dst_destroy(struct dst_entry *dst)
1267 {
1268 struct rtable *rt = (struct rtable *) dst;
1269
1270 if (dst->flags & DST_NOCACHE) {
1271 spin_lock_bh(&rt_uncached_lock);
1272 list_del(&rt->rt_uncached);
1273 spin_unlock_bh(&rt_uncached_lock);
1274 }
1275 }
1276
1277 void rt_flush_dev(struct net_device *dev)
1278 {
1279 if (!list_empty(&rt_uncached_list)) {
1280 struct net *net = dev_net(dev);
1281 struct rtable *rt;
1282
1283 spin_lock_bh(&rt_uncached_lock);
1284 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1285 if (rt->dst.dev != dev)
1286 continue;
1287 rt->dst.dev = net->loopback_dev;
1288 dev_hold(rt->dst.dev);
1289 dev_put(dev);
1290 }
1291 spin_unlock_bh(&rt_uncached_lock);
1292 }
1293 }
1294
1295 static bool rt_cache_valid(const struct rtable *rt)
1296 {
1297 return rt &&
1298 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1299 !rt_is_expired(rt);
1300 }
1301
1302 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1303 const struct fib_result *res,
1304 struct fib_nh_exception *fnhe,
1305 struct fib_info *fi, u16 type, u32 itag)
1306 {
1307 bool cached = false;
1308
1309 if (fi) {
1310 struct fib_nh *nh = &FIB_RES_NH(*res);
1311
1312 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK)
1313 rt->rt_gateway = nh->nh_gw;
1314 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1315 #ifdef CONFIG_IP_ROUTE_CLASSID
1316 rt->dst.tclassid = nh->nh_tclassid;
1317 #endif
1318 if (unlikely(fnhe))
1319 cached = rt_bind_exception(rt, fnhe, daddr);
1320 else if (!(rt->dst.flags & DST_NOCACHE))
1321 cached = rt_cache_route(nh, rt);
1322 }
1323 if (unlikely(!cached))
1324 rt_add_uncached_list(rt);
1325
1326 #ifdef CONFIG_IP_ROUTE_CLASSID
1327 #ifdef CONFIG_IP_MULTIPLE_TABLES
1328 set_class_tag(rt, res->tclassid);
1329 #endif
1330 set_class_tag(rt, itag);
1331 #endif
1332 }
1333
1334 static struct rtable *rt_dst_alloc(struct net_device *dev,
1335 bool nopolicy, bool noxfrm, bool will_cache)
1336 {
1337 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1338 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1339 (nopolicy ? DST_NOPOLICY : 0) |
1340 (noxfrm ? DST_NOXFRM : 0));
1341 }
1342
1343 /* called in rcu_read_lock() section */
1344 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1345 u8 tos, struct net_device *dev, int our)
1346 {
1347 struct rtable *rth;
1348 struct in_device *in_dev = __in_dev_get_rcu(dev);
1349 u32 itag = 0;
1350 int err;
1351
1352 /* Primary sanity checks. */
1353
1354 if (in_dev == NULL)
1355 return -EINVAL;
1356
1357 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1358 skb->protocol != htons(ETH_P_IP))
1359 goto e_inval;
1360
1361 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1362 if (ipv4_is_loopback(saddr))
1363 goto e_inval;
1364
1365 if (ipv4_is_zeronet(saddr)) {
1366 if (!ipv4_is_local_multicast(daddr))
1367 goto e_inval;
1368 } else {
1369 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1370 in_dev, &itag);
1371 if (err < 0)
1372 goto e_err;
1373 }
1374 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1375 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1376 if (!rth)
1377 goto e_nobufs;
1378
1379 #ifdef CONFIG_IP_ROUTE_CLASSID
1380 rth->dst.tclassid = itag;
1381 #endif
1382 rth->dst.output = ip_rt_bug;
1383
1384 rth->rt_genid = rt_genid(dev_net(dev));
1385 rth->rt_flags = RTCF_MULTICAST;
1386 rth->rt_type = RTN_MULTICAST;
1387 rth->rt_is_input= 1;
1388 rth->rt_iif = 0;
1389 rth->rt_pmtu = 0;
1390 rth->rt_gateway = 0;
1391 INIT_LIST_HEAD(&rth->rt_uncached);
1392 if (our) {
1393 rth->dst.input= ip_local_deliver;
1394 rth->rt_flags |= RTCF_LOCAL;
1395 }
1396
1397 #ifdef CONFIG_IP_MROUTE
1398 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1399 rth->dst.input = ip_mr_input;
1400 #endif
1401 RT_CACHE_STAT_INC(in_slow_mc);
1402
1403 skb_dst_set(skb, &rth->dst);
1404 return 0;
1405
1406 e_nobufs:
1407 return -ENOBUFS;
1408 e_inval:
1409 return -EINVAL;
1410 e_err:
1411 return err;
1412 }
1413
1414
1415 static void ip_handle_martian_source(struct net_device *dev,
1416 struct in_device *in_dev,
1417 struct sk_buff *skb,
1418 __be32 daddr,
1419 __be32 saddr)
1420 {
1421 RT_CACHE_STAT_INC(in_martian_src);
1422 #ifdef CONFIG_IP_ROUTE_VERBOSE
1423 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1424 /*
1425 * RFC1812 recommendation, if source is martian,
1426 * the only hint is MAC header.
1427 */
1428 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1429 &daddr, &saddr, dev->name);
1430 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1431 print_hex_dump(KERN_WARNING, "ll header: ",
1432 DUMP_PREFIX_OFFSET, 16, 1,
1433 skb_mac_header(skb),
1434 dev->hard_header_len, true);
1435 }
1436 }
1437 #endif
1438 }
1439
1440 /* called in rcu_read_lock() section */
1441 static int __mkroute_input(struct sk_buff *skb,
1442 const struct fib_result *res,
1443 struct in_device *in_dev,
1444 __be32 daddr, __be32 saddr, u32 tos)
1445 {
1446 struct rtable *rth;
1447 int err;
1448 struct in_device *out_dev;
1449 unsigned int flags = 0;
1450 bool do_cache;
1451 u32 itag;
1452
1453 /* get a working reference to the output device */
1454 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1455 if (out_dev == NULL) {
1456 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1457 return -EINVAL;
1458 }
1459
1460
1461 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1462 in_dev->dev, in_dev, &itag);
1463 if (err < 0) {
1464 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1465 saddr);
1466
1467 goto cleanup;
1468 }
1469
1470 if (out_dev == in_dev && err &&
1471 (IN_DEV_SHARED_MEDIA(out_dev) ||
1472 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1473 flags |= RTCF_DOREDIRECT;
1474
1475 if (skb->protocol != htons(ETH_P_IP)) {
1476 /* Not IP (i.e. ARP). Do not create route, if it is
1477 * invalid for proxy arp. DNAT routes are always valid.
1478 *
1479 * Proxy arp feature have been extended to allow, ARP
1480 * replies back to the same interface, to support
1481 * Private VLAN switch technologies. See arp.c.
1482 */
1483 if (out_dev == in_dev &&
1484 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1485 err = -EINVAL;
1486 goto cleanup;
1487 }
1488 }
1489
1490 do_cache = false;
1491 if (res->fi) {
1492 if (!itag) {
1493 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1494 if (rt_cache_valid(rth)) {
1495 skb_dst_set_noref(skb, &rth->dst);
1496 goto out;
1497 }
1498 do_cache = true;
1499 }
1500 }
1501
1502 rth = rt_dst_alloc(out_dev->dev,
1503 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1504 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1505 if (!rth) {
1506 err = -ENOBUFS;
1507 goto cleanup;
1508 }
1509
1510 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
1511 rth->rt_flags = flags;
1512 rth->rt_type = res->type;
1513 rth->rt_is_input = 1;
1514 rth->rt_iif = 0;
1515 rth->rt_pmtu = 0;
1516 rth->rt_gateway = 0;
1517 INIT_LIST_HEAD(&rth->rt_uncached);
1518
1519 rth->dst.input = ip_forward;
1520 rth->dst.output = ip_output;
1521
1522 rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag);
1523 skb_dst_set(skb, &rth->dst);
1524 out:
1525 err = 0;
1526 cleanup:
1527 return err;
1528 }
1529
1530 static int ip_mkroute_input(struct sk_buff *skb,
1531 struct fib_result *res,
1532 const struct flowi4 *fl4,
1533 struct in_device *in_dev,
1534 __be32 daddr, __be32 saddr, u32 tos)
1535 {
1536 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1537 if (res->fi && res->fi->fib_nhs > 1)
1538 fib_select_multipath(res);
1539 #endif
1540
1541 /* create a routing cache entry */
1542 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1543 }
1544
1545 /*
1546 * NOTE. We drop all the packets that has local source
1547 * addresses, because every properly looped back packet
1548 * must have correct destination already attached by output routine.
1549 *
1550 * Such approach solves two big problems:
1551 * 1. Not simplex devices are handled properly.
1552 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1553 * called with rcu_read_lock()
1554 */
1555
1556 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1557 u8 tos, struct net_device *dev)
1558 {
1559 struct fib_result res;
1560 struct in_device *in_dev = __in_dev_get_rcu(dev);
1561 struct flowi4 fl4;
1562 unsigned int flags = 0;
1563 u32 itag = 0;
1564 struct rtable *rth;
1565 int err = -EINVAL;
1566 struct net *net = dev_net(dev);
1567 bool do_cache;
1568
1569 /* IP on this device is disabled. */
1570
1571 if (!in_dev)
1572 goto out;
1573
1574 /* Check for the most weird martians, which can be not detected
1575 by fib_lookup.
1576 */
1577
1578 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1579 goto martian_source;
1580
1581 res.fi = NULL;
1582 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1583 goto brd_input;
1584
1585 /* Accept zero addresses only to limited broadcast;
1586 * I even do not know to fix it or not. Waiting for complains :-)
1587 */
1588 if (ipv4_is_zeronet(saddr))
1589 goto martian_source;
1590
1591 if (ipv4_is_zeronet(daddr))
1592 goto martian_destination;
1593
1594 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) {
1595 if (ipv4_is_loopback(daddr))
1596 goto martian_destination;
1597
1598 if (ipv4_is_loopback(saddr))
1599 goto martian_source;
1600 }
1601
1602 /*
1603 * Now we are ready to route packet.
1604 */
1605 fl4.flowi4_oif = 0;
1606 fl4.flowi4_iif = dev->ifindex;
1607 fl4.flowi4_mark = skb->mark;
1608 fl4.flowi4_tos = tos;
1609 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1610 fl4.daddr = daddr;
1611 fl4.saddr = saddr;
1612 err = fib_lookup(net, &fl4, &res);
1613 if (err != 0)
1614 goto no_route;
1615
1616 RT_CACHE_STAT_INC(in_slow_tot);
1617
1618 if (res.type == RTN_BROADCAST)
1619 goto brd_input;
1620
1621 if (res.type == RTN_LOCAL) {
1622 err = fib_validate_source(skb, saddr, daddr, tos,
1623 net->loopback_dev->ifindex,
1624 dev, in_dev, &itag);
1625 if (err < 0)
1626 goto martian_source_keep_err;
1627 goto local_input;
1628 }
1629
1630 if (!IN_DEV_FORWARD(in_dev))
1631 goto no_route;
1632 if (res.type != RTN_UNICAST)
1633 goto martian_destination;
1634
1635 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1636 out: return err;
1637
1638 brd_input:
1639 if (skb->protocol != htons(ETH_P_IP))
1640 goto e_inval;
1641
1642 if (!ipv4_is_zeronet(saddr)) {
1643 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1644 in_dev, &itag);
1645 if (err < 0)
1646 goto martian_source_keep_err;
1647 }
1648 flags |= RTCF_BROADCAST;
1649 res.type = RTN_BROADCAST;
1650 RT_CACHE_STAT_INC(in_brd);
1651
1652 local_input:
1653 do_cache = false;
1654 if (res.fi) {
1655 if (!itag) {
1656 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1657 if (rt_cache_valid(rth)) {
1658 skb_dst_set_noref(skb, &rth->dst);
1659 err = 0;
1660 goto out;
1661 }
1662 do_cache = true;
1663 }
1664 }
1665
1666 rth = rt_dst_alloc(net->loopback_dev,
1667 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1668 if (!rth)
1669 goto e_nobufs;
1670
1671 rth->dst.input= ip_local_deliver;
1672 rth->dst.output= ip_rt_bug;
1673 #ifdef CONFIG_IP_ROUTE_CLASSID
1674 rth->dst.tclassid = itag;
1675 #endif
1676
1677 rth->rt_genid = rt_genid(net);
1678 rth->rt_flags = flags|RTCF_LOCAL;
1679 rth->rt_type = res.type;
1680 rth->rt_is_input = 1;
1681 rth->rt_iif = 0;
1682 rth->rt_pmtu = 0;
1683 rth->rt_gateway = 0;
1684 INIT_LIST_HEAD(&rth->rt_uncached);
1685 if (res.type == RTN_UNREACHABLE) {
1686 rth->dst.input= ip_error;
1687 rth->dst.error= -err;
1688 rth->rt_flags &= ~RTCF_LOCAL;
1689 }
1690 if (do_cache)
1691 rt_cache_route(&FIB_RES_NH(res), rth);
1692 skb_dst_set(skb, &rth->dst);
1693 err = 0;
1694 goto out;
1695
1696 no_route:
1697 RT_CACHE_STAT_INC(in_no_route);
1698 res.type = RTN_UNREACHABLE;
1699 if (err == -ESRCH)
1700 err = -ENETUNREACH;
1701 goto local_input;
1702
1703 /*
1704 * Do not cache martian addresses: they should be logged (RFC1812)
1705 */
1706 martian_destination:
1707 RT_CACHE_STAT_INC(in_martian_dst);
1708 #ifdef CONFIG_IP_ROUTE_VERBOSE
1709 if (IN_DEV_LOG_MARTIANS(in_dev))
1710 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1711 &daddr, &saddr, dev->name);
1712 #endif
1713
1714 e_inval:
1715 err = -EINVAL;
1716 goto out;
1717
1718 e_nobufs:
1719 err = -ENOBUFS;
1720 goto out;
1721
1722 martian_source:
1723 err = -EINVAL;
1724 martian_source_keep_err:
1725 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1726 goto out;
1727 }
1728
1729 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1730 u8 tos, struct net_device *dev)
1731 {
1732 int res;
1733
1734 rcu_read_lock();
1735
1736 /* Multicast recognition logic is moved from route cache to here.
1737 The problem was that too many Ethernet cards have broken/missing
1738 hardware multicast filters :-( As result the host on multicasting
1739 network acquires a lot of useless route cache entries, sort of
1740 SDR messages from all the world. Now we try to get rid of them.
1741 Really, provided software IP multicast filter is organized
1742 reasonably (at least, hashed), it does not result in a slowdown
1743 comparing with route cache reject entries.
1744 Note, that multicast routers are not affected, because
1745 route cache entry is created eventually.
1746 */
1747 if (ipv4_is_multicast(daddr)) {
1748 struct in_device *in_dev = __in_dev_get_rcu(dev);
1749
1750 if (in_dev) {
1751 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1752 ip_hdr(skb)->protocol);
1753 if (our
1754 #ifdef CONFIG_IP_MROUTE
1755 ||
1756 (!ipv4_is_local_multicast(daddr) &&
1757 IN_DEV_MFORWARD(in_dev))
1758 #endif
1759 ) {
1760 int res = ip_route_input_mc(skb, daddr, saddr,
1761 tos, dev, our);
1762 rcu_read_unlock();
1763 return res;
1764 }
1765 }
1766 rcu_read_unlock();
1767 return -EINVAL;
1768 }
1769 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1770 rcu_read_unlock();
1771 return res;
1772 }
1773 EXPORT_SYMBOL(ip_route_input_noref);
1774
1775 /* called with rcu_read_lock() */
1776 static struct rtable *__mkroute_output(const struct fib_result *res,
1777 const struct flowi4 *fl4, int orig_oif,
1778 struct net_device *dev_out,
1779 unsigned int flags)
1780 {
1781 struct fib_info *fi = res->fi;
1782 struct fib_nh_exception *fnhe;
1783 struct in_device *in_dev;
1784 u16 type = res->type;
1785 struct rtable *rth;
1786
1787 in_dev = __in_dev_get_rcu(dev_out);
1788 if (!in_dev)
1789 return ERR_PTR(-EINVAL);
1790
1791 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1792 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1793 return ERR_PTR(-EINVAL);
1794
1795 if (ipv4_is_lbcast(fl4->daddr))
1796 type = RTN_BROADCAST;
1797 else if (ipv4_is_multicast(fl4->daddr))
1798 type = RTN_MULTICAST;
1799 else if (ipv4_is_zeronet(fl4->daddr))
1800 return ERR_PTR(-EINVAL);
1801
1802 if (dev_out->flags & IFF_LOOPBACK)
1803 flags |= RTCF_LOCAL;
1804
1805 if (type == RTN_BROADCAST) {
1806 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1807 fi = NULL;
1808 } else if (type == RTN_MULTICAST) {
1809 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1810 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1811 fl4->flowi4_proto))
1812 flags &= ~RTCF_LOCAL;
1813 /* If multicast route do not exist use
1814 * default one, but do not gateway in this case.
1815 * Yes, it is hack.
1816 */
1817 if (fi && res->prefixlen < 4)
1818 fi = NULL;
1819 }
1820
1821 fnhe = NULL;
1822 if (fi) {
1823 struct rtable __rcu **prth;
1824
1825 fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr);
1826 if (fnhe)
1827 prth = &fnhe->fnhe_rth;
1828 else
1829 prth = __this_cpu_ptr(FIB_RES_NH(*res).nh_pcpu_rth_output);
1830 rth = rcu_dereference(*prth);
1831 if (rt_cache_valid(rth)) {
1832 dst_hold(&rth->dst);
1833 return rth;
1834 }
1835 }
1836 rth = rt_dst_alloc(dev_out,
1837 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1838 IN_DEV_CONF_GET(in_dev, NOXFRM),
1839 fi);
1840 if (!rth)
1841 return ERR_PTR(-ENOBUFS);
1842
1843 rth->dst.output = ip_output;
1844
1845 rth->rt_genid = rt_genid(dev_net(dev_out));
1846 rth->rt_flags = flags;
1847 rth->rt_type = type;
1848 rth->rt_is_input = 0;
1849 rth->rt_iif = orig_oif ? : 0;
1850 rth->rt_pmtu = 0;
1851 rth->rt_gateway = 0;
1852 INIT_LIST_HEAD(&rth->rt_uncached);
1853
1854 RT_CACHE_STAT_INC(out_slow_tot);
1855
1856 if (flags & RTCF_LOCAL)
1857 rth->dst.input = ip_local_deliver;
1858 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1859 if (flags & RTCF_LOCAL &&
1860 !(dev_out->flags & IFF_LOOPBACK)) {
1861 rth->dst.output = ip_mc_output;
1862 RT_CACHE_STAT_INC(out_slow_mc);
1863 }
1864 #ifdef CONFIG_IP_MROUTE
1865 if (type == RTN_MULTICAST) {
1866 if (IN_DEV_MFORWARD(in_dev) &&
1867 !ipv4_is_local_multicast(fl4->daddr)) {
1868 rth->dst.input = ip_mr_input;
1869 rth->dst.output = ip_mc_output;
1870 }
1871 }
1872 #endif
1873 }
1874
1875 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1876
1877 return rth;
1878 }
1879
1880 /*
1881 * Major route resolver routine.
1882 */
1883
1884 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1885 {
1886 struct net_device *dev_out = NULL;
1887 __u8 tos = RT_FL_TOS(fl4);
1888 unsigned int flags = 0;
1889 struct fib_result res;
1890 struct rtable *rth;
1891 int orig_oif;
1892
1893 res.tclassid = 0;
1894 res.fi = NULL;
1895 res.table = NULL;
1896
1897 orig_oif = fl4->flowi4_oif;
1898
1899 fl4->flowi4_iif = net->loopback_dev->ifindex;
1900 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
1901 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
1902 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
1903
1904 rcu_read_lock();
1905 if (fl4->saddr) {
1906 rth = ERR_PTR(-EINVAL);
1907 if (ipv4_is_multicast(fl4->saddr) ||
1908 ipv4_is_lbcast(fl4->saddr) ||
1909 ipv4_is_zeronet(fl4->saddr))
1910 goto out;
1911
1912 /* I removed check for oif == dev_out->oif here.
1913 It was wrong for two reasons:
1914 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
1915 is assigned to multiple interfaces.
1916 2. Moreover, we are allowed to send packets with saddr
1917 of another iface. --ANK
1918 */
1919
1920 if (fl4->flowi4_oif == 0 &&
1921 (ipv4_is_multicast(fl4->daddr) ||
1922 ipv4_is_lbcast(fl4->daddr))) {
1923 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1924 dev_out = __ip_dev_find(net, fl4->saddr, false);
1925 if (dev_out == NULL)
1926 goto out;
1927
1928 /* Special hack: user can direct multicasts
1929 and limited broadcast via necessary interface
1930 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
1931 This hack is not just for fun, it allows
1932 vic,vat and friends to work.
1933 They bind socket to loopback, set ttl to zero
1934 and expect that it will work.
1935 From the viewpoint of routing cache they are broken,
1936 because we are not allowed to build multicast path
1937 with loopback source addr (look, routing cache
1938 cannot know, that ttl is zero, so that packet
1939 will not leave this host and route is valid).
1940 Luckily, this hack is good workaround.
1941 */
1942
1943 fl4->flowi4_oif = dev_out->ifindex;
1944 goto make_route;
1945 }
1946
1947 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
1948 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1949 if (!__ip_dev_find(net, fl4->saddr, false))
1950 goto out;
1951 }
1952 }
1953
1954
1955 if (fl4->flowi4_oif) {
1956 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
1957 rth = ERR_PTR(-ENODEV);
1958 if (dev_out == NULL)
1959 goto out;
1960
1961 /* RACE: Check return value of inet_select_addr instead. */
1962 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
1963 rth = ERR_PTR(-ENETUNREACH);
1964 goto out;
1965 }
1966 if (ipv4_is_local_multicast(fl4->daddr) ||
1967 ipv4_is_lbcast(fl4->daddr)) {
1968 if (!fl4->saddr)
1969 fl4->saddr = inet_select_addr(dev_out, 0,
1970 RT_SCOPE_LINK);
1971 goto make_route;
1972 }
1973 if (fl4->saddr) {
1974 if (ipv4_is_multicast(fl4->daddr))
1975 fl4->saddr = inet_select_addr(dev_out, 0,
1976 fl4->flowi4_scope);
1977 else if (!fl4->daddr)
1978 fl4->saddr = inet_select_addr(dev_out, 0,
1979 RT_SCOPE_HOST);
1980 }
1981 }
1982
1983 if (!fl4->daddr) {
1984 fl4->daddr = fl4->saddr;
1985 if (!fl4->daddr)
1986 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
1987 dev_out = net->loopback_dev;
1988 fl4->flowi4_oif = net->loopback_dev->ifindex;
1989 res.type = RTN_LOCAL;
1990 flags |= RTCF_LOCAL;
1991 goto make_route;
1992 }
1993
1994 if (fib_lookup(net, fl4, &res)) {
1995 res.fi = NULL;
1996 res.table = NULL;
1997 if (fl4->flowi4_oif) {
1998 /* Apparently, routing tables are wrong. Assume,
1999 that the destination is on link.
2000
2001 WHY? DW.
2002 Because we are allowed to send to iface
2003 even if it has NO routes and NO assigned
2004 addresses. When oif is specified, routing
2005 tables are looked up with only one purpose:
2006 to catch if destination is gatewayed, rather than
2007 direct. Moreover, if MSG_DONTROUTE is set,
2008 we send packet, ignoring both routing tables
2009 and ifaddr state. --ANK
2010
2011
2012 We could make it even if oif is unknown,
2013 likely IPv6, but we do not.
2014 */
2015
2016 if (fl4->saddr == 0)
2017 fl4->saddr = inet_select_addr(dev_out, 0,
2018 RT_SCOPE_LINK);
2019 res.type = RTN_UNICAST;
2020 goto make_route;
2021 }
2022 rth = ERR_PTR(-ENETUNREACH);
2023 goto out;
2024 }
2025
2026 if (res.type == RTN_LOCAL) {
2027 if (!fl4->saddr) {
2028 if (res.fi->fib_prefsrc)
2029 fl4->saddr = res.fi->fib_prefsrc;
2030 else
2031 fl4->saddr = fl4->daddr;
2032 }
2033 dev_out = net->loopback_dev;
2034 fl4->flowi4_oif = dev_out->ifindex;
2035 res.fi = NULL;
2036 flags |= RTCF_LOCAL;
2037 goto make_route;
2038 }
2039
2040 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2041 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2042 fib_select_multipath(&res);
2043 else
2044 #endif
2045 if (!res.prefixlen &&
2046 res.table->tb_num_default > 1 &&
2047 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2048 fib_select_default(&res);
2049
2050 if (!fl4->saddr)
2051 fl4->saddr = FIB_RES_PREFSRC(net, res);
2052
2053 dev_out = FIB_RES_DEV(res);
2054 fl4->flowi4_oif = dev_out->ifindex;
2055
2056
2057 make_route:
2058 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2059
2060 out:
2061 rcu_read_unlock();
2062 return rth;
2063 }
2064 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2065
2066 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2067 {
2068 return NULL;
2069 }
2070
2071 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2072 {
2073 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2074
2075 return mtu ? : dst->dev->mtu;
2076 }
2077
2078 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2079 struct sk_buff *skb, u32 mtu)
2080 {
2081 }
2082
2083 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2084 struct sk_buff *skb)
2085 {
2086 }
2087
2088 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2089 unsigned long old)
2090 {
2091 return NULL;
2092 }
2093
2094 static struct dst_ops ipv4_dst_blackhole_ops = {
2095 .family = AF_INET,
2096 .protocol = cpu_to_be16(ETH_P_IP),
2097 .check = ipv4_blackhole_dst_check,
2098 .mtu = ipv4_blackhole_mtu,
2099 .default_advmss = ipv4_default_advmss,
2100 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2101 .redirect = ipv4_rt_blackhole_redirect,
2102 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2103 .neigh_lookup = ipv4_neigh_lookup,
2104 };
2105
2106 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2107 {
2108 struct rtable *ort = (struct rtable *) dst_orig;
2109 struct rtable *rt;
2110
2111 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2112 if (rt) {
2113 struct dst_entry *new = &rt->dst;
2114
2115 new->__use = 1;
2116 new->input = dst_discard;
2117 new->output = dst_discard;
2118
2119 new->dev = ort->dst.dev;
2120 if (new->dev)
2121 dev_hold(new->dev);
2122
2123 rt->rt_is_input = ort->rt_is_input;
2124 rt->rt_iif = ort->rt_iif;
2125 rt->rt_pmtu = ort->rt_pmtu;
2126
2127 rt->rt_genid = rt_genid(net);
2128 rt->rt_flags = ort->rt_flags;
2129 rt->rt_type = ort->rt_type;
2130 rt->rt_gateway = ort->rt_gateway;
2131
2132 INIT_LIST_HEAD(&rt->rt_uncached);
2133
2134 dst_free(new);
2135 }
2136
2137 dst_release(dst_orig);
2138
2139 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2140 }
2141
2142 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2143 struct sock *sk)
2144 {
2145 struct rtable *rt = __ip_route_output_key(net, flp4);
2146
2147 if (IS_ERR(rt))
2148 return rt;
2149
2150 if (flp4->flowi4_proto)
2151 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2152 flowi4_to_flowi(flp4),
2153 sk, 0);
2154
2155 return rt;
2156 }
2157 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2158
2159 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2160 struct flowi4 *fl4, struct sk_buff *skb, u32 pid,
2161 u32 seq, int event, int nowait, unsigned int flags)
2162 {
2163 struct rtable *rt = skb_rtable(skb);
2164 struct rtmsg *r;
2165 struct nlmsghdr *nlh;
2166 unsigned long expires = 0;
2167 u32 error;
2168 u32 metrics[RTAX_MAX];
2169
2170 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2171 if (nlh == NULL)
2172 return -EMSGSIZE;
2173
2174 r = nlmsg_data(nlh);
2175 r->rtm_family = AF_INET;
2176 r->rtm_dst_len = 32;
2177 r->rtm_src_len = 0;
2178 r->rtm_tos = fl4->flowi4_tos;
2179 r->rtm_table = RT_TABLE_MAIN;
2180 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2181 goto nla_put_failure;
2182 r->rtm_type = rt->rt_type;
2183 r->rtm_scope = RT_SCOPE_UNIVERSE;
2184 r->rtm_protocol = RTPROT_UNSPEC;
2185 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2186 if (rt->rt_flags & RTCF_NOTIFY)
2187 r->rtm_flags |= RTM_F_NOTIFY;
2188
2189 if (nla_put_be32(skb, RTA_DST, dst))
2190 goto nla_put_failure;
2191 if (src) {
2192 r->rtm_src_len = 32;
2193 if (nla_put_be32(skb, RTA_SRC, src))
2194 goto nla_put_failure;
2195 }
2196 if (rt->dst.dev &&
2197 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2198 goto nla_put_failure;
2199 #ifdef CONFIG_IP_ROUTE_CLASSID
2200 if (rt->dst.tclassid &&
2201 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2202 goto nla_put_failure;
2203 #endif
2204 if (!rt_is_input_route(rt) &&
2205 fl4->saddr != src) {
2206 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2207 goto nla_put_failure;
2208 }
2209 if (rt->rt_gateway &&
2210 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2211 goto nla_put_failure;
2212
2213 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2214 if (rt->rt_pmtu)
2215 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2216 if (rtnetlink_put_metrics(skb, metrics) < 0)
2217 goto nla_put_failure;
2218
2219 if (fl4->flowi4_mark &&
2220 nla_put_be32(skb, RTA_MARK, fl4->flowi4_mark))
2221 goto nla_put_failure;
2222
2223 error = rt->dst.error;
2224 expires = rt->dst.expires;
2225 if (expires) {
2226 if (time_before(jiffies, expires))
2227 expires -= jiffies;
2228 else
2229 expires = 0;
2230 }
2231
2232 if (rt_is_input_route(rt)) {
2233 if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
2234 goto nla_put_failure;
2235 }
2236
2237 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2238 goto nla_put_failure;
2239
2240 return nlmsg_end(skb, nlh);
2241
2242 nla_put_failure:
2243 nlmsg_cancel(skb, nlh);
2244 return -EMSGSIZE;
2245 }
2246
2247 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
2248 {
2249 struct net *net = sock_net(in_skb->sk);
2250 struct rtmsg *rtm;
2251 struct nlattr *tb[RTA_MAX+1];
2252 struct rtable *rt = NULL;
2253 struct flowi4 fl4;
2254 __be32 dst = 0;
2255 __be32 src = 0;
2256 u32 iif;
2257 int err;
2258 int mark;
2259 struct sk_buff *skb;
2260
2261 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2262 if (err < 0)
2263 goto errout;
2264
2265 rtm = nlmsg_data(nlh);
2266
2267 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2268 if (skb == NULL) {
2269 err = -ENOBUFS;
2270 goto errout;
2271 }
2272
2273 /* Reserve room for dummy headers, this skb can pass
2274 through good chunk of routing engine.
2275 */
2276 skb_reset_mac_header(skb);
2277 skb_reset_network_header(skb);
2278
2279 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2280 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2281 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2282
2283 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2284 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2285 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2286 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2287
2288 memset(&fl4, 0, sizeof(fl4));
2289 fl4.daddr = dst;
2290 fl4.saddr = src;
2291 fl4.flowi4_tos = rtm->rtm_tos;
2292 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2293 fl4.flowi4_mark = mark;
2294
2295 if (iif) {
2296 struct net_device *dev;
2297
2298 dev = __dev_get_by_index(net, iif);
2299 if (dev == NULL) {
2300 err = -ENODEV;
2301 goto errout_free;
2302 }
2303
2304 skb->protocol = htons(ETH_P_IP);
2305 skb->dev = dev;
2306 skb->mark = mark;
2307 local_bh_disable();
2308 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2309 local_bh_enable();
2310
2311 rt = skb_rtable(skb);
2312 if (err == 0 && rt->dst.error)
2313 err = -rt->dst.error;
2314 } else {
2315 rt = ip_route_output_key(net, &fl4);
2316
2317 err = 0;
2318 if (IS_ERR(rt))
2319 err = PTR_ERR(rt);
2320 }
2321
2322 if (err)
2323 goto errout_free;
2324
2325 skb_dst_set(skb, &rt->dst);
2326 if (rtm->rtm_flags & RTM_F_NOTIFY)
2327 rt->rt_flags |= RTCF_NOTIFY;
2328
2329 err = rt_fill_info(net, dst, src, &fl4, skb,
2330 NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2331 RTM_NEWROUTE, 0, 0);
2332 if (err <= 0)
2333 goto errout_free;
2334
2335 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2336 errout:
2337 return err;
2338
2339 errout_free:
2340 kfree_skb(skb);
2341 goto errout;
2342 }
2343
2344 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2345 {
2346 return skb->len;
2347 }
2348
2349 void ip_rt_multicast_event(struct in_device *in_dev)
2350 {
2351 rt_cache_flush(dev_net(in_dev->dev), 0);
2352 }
2353
2354 #ifdef CONFIG_SYSCTL
2355 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
2356 void __user *buffer,
2357 size_t *lenp, loff_t *ppos)
2358 {
2359 if (write) {
2360 int flush_delay;
2361 ctl_table ctl;
2362 struct net *net;
2363
2364 memcpy(&ctl, __ctl, sizeof(ctl));
2365 ctl.data = &flush_delay;
2366 proc_dointvec(&ctl, write, buffer, lenp, ppos);
2367
2368 net = (struct net *)__ctl->extra1;
2369 rt_cache_flush(net, flush_delay);
2370 return 0;
2371 }
2372
2373 return -EINVAL;
2374 }
2375
2376 static ctl_table ipv4_route_table[] = {
2377 {
2378 .procname = "gc_thresh",
2379 .data = &ipv4_dst_ops.gc_thresh,
2380 .maxlen = sizeof(int),
2381 .mode = 0644,
2382 .proc_handler = proc_dointvec,
2383 },
2384 {
2385 .procname = "max_size",
2386 .data = &ip_rt_max_size,
2387 .maxlen = sizeof(int),
2388 .mode = 0644,
2389 .proc_handler = proc_dointvec,
2390 },
2391 {
2392 /* Deprecated. Use gc_min_interval_ms */
2393
2394 .procname = "gc_min_interval",
2395 .data = &ip_rt_gc_min_interval,
2396 .maxlen = sizeof(int),
2397 .mode = 0644,
2398 .proc_handler = proc_dointvec_jiffies,
2399 },
2400 {
2401 .procname = "gc_min_interval_ms",
2402 .data = &ip_rt_gc_min_interval,
2403 .maxlen = sizeof(int),
2404 .mode = 0644,
2405 .proc_handler = proc_dointvec_ms_jiffies,
2406 },
2407 {
2408 .procname = "gc_timeout",
2409 .data = &ip_rt_gc_timeout,
2410 .maxlen = sizeof(int),
2411 .mode = 0644,
2412 .proc_handler = proc_dointvec_jiffies,
2413 },
2414 {
2415 .procname = "gc_interval",
2416 .data = &ip_rt_gc_interval,
2417 .maxlen = sizeof(int),
2418 .mode = 0644,
2419 .proc_handler = proc_dointvec_jiffies,
2420 },
2421 {
2422 .procname = "redirect_load",
2423 .data = &ip_rt_redirect_load,
2424 .maxlen = sizeof(int),
2425 .mode = 0644,
2426 .proc_handler = proc_dointvec,
2427 },
2428 {
2429 .procname = "redirect_number",
2430 .data = &ip_rt_redirect_number,
2431 .maxlen = sizeof(int),
2432 .mode = 0644,
2433 .proc_handler = proc_dointvec,
2434 },
2435 {
2436 .procname = "redirect_silence",
2437 .data = &ip_rt_redirect_silence,
2438 .maxlen = sizeof(int),
2439 .mode = 0644,
2440 .proc_handler = proc_dointvec,
2441 },
2442 {
2443 .procname = "error_cost",
2444 .data = &ip_rt_error_cost,
2445 .maxlen = sizeof(int),
2446 .mode = 0644,
2447 .proc_handler = proc_dointvec,
2448 },
2449 {
2450 .procname = "error_burst",
2451 .data = &ip_rt_error_burst,
2452 .maxlen = sizeof(int),
2453 .mode = 0644,
2454 .proc_handler = proc_dointvec,
2455 },
2456 {
2457 .procname = "gc_elasticity",
2458 .data = &ip_rt_gc_elasticity,
2459 .maxlen = sizeof(int),
2460 .mode = 0644,
2461 .proc_handler = proc_dointvec,
2462 },
2463 {
2464 .procname = "mtu_expires",
2465 .data = &ip_rt_mtu_expires,
2466 .maxlen = sizeof(int),
2467 .mode = 0644,
2468 .proc_handler = proc_dointvec_jiffies,
2469 },
2470 {
2471 .procname = "min_pmtu",
2472 .data = &ip_rt_min_pmtu,
2473 .maxlen = sizeof(int),
2474 .mode = 0644,
2475 .proc_handler = proc_dointvec,
2476 },
2477 {
2478 .procname = "min_adv_mss",
2479 .data = &ip_rt_min_advmss,
2480 .maxlen = sizeof(int),
2481 .mode = 0644,
2482 .proc_handler = proc_dointvec,
2483 },
2484 { }
2485 };
2486
2487 static struct ctl_table ipv4_route_flush_table[] = {
2488 {
2489 .procname = "flush",
2490 .maxlen = sizeof(int),
2491 .mode = 0200,
2492 .proc_handler = ipv4_sysctl_rtcache_flush,
2493 },
2494 { },
2495 };
2496
2497 static __net_init int sysctl_route_net_init(struct net *net)
2498 {
2499 struct ctl_table *tbl;
2500
2501 tbl = ipv4_route_flush_table;
2502 if (!net_eq(net, &init_net)) {
2503 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2504 if (tbl == NULL)
2505 goto err_dup;
2506 }
2507 tbl[0].extra1 = net;
2508
2509 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2510 if (net->ipv4.route_hdr == NULL)
2511 goto err_reg;
2512 return 0;
2513
2514 err_reg:
2515 if (tbl != ipv4_route_flush_table)
2516 kfree(tbl);
2517 err_dup:
2518 return -ENOMEM;
2519 }
2520
2521 static __net_exit void sysctl_route_net_exit(struct net *net)
2522 {
2523 struct ctl_table *tbl;
2524
2525 tbl = net->ipv4.route_hdr->ctl_table_arg;
2526 unregister_net_sysctl_table(net->ipv4.route_hdr);
2527 BUG_ON(tbl == ipv4_route_flush_table);
2528 kfree(tbl);
2529 }
2530
2531 static __net_initdata struct pernet_operations sysctl_route_ops = {
2532 .init = sysctl_route_net_init,
2533 .exit = sysctl_route_net_exit,
2534 };
2535 #endif
2536
2537 static __net_init int rt_genid_init(struct net *net)
2538 {
2539 get_random_bytes(&net->ipv4.rt_genid,
2540 sizeof(net->ipv4.rt_genid));
2541 get_random_bytes(&net->ipv4.dev_addr_genid,
2542 sizeof(net->ipv4.dev_addr_genid));
2543 return 0;
2544 }
2545
2546 static __net_initdata struct pernet_operations rt_genid_ops = {
2547 .init = rt_genid_init,
2548 };
2549
2550 static int __net_init ipv4_inetpeer_init(struct net *net)
2551 {
2552 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2553
2554 if (!bp)
2555 return -ENOMEM;
2556 inet_peer_base_init(bp);
2557 net->ipv4.peers = bp;
2558 return 0;
2559 }
2560
2561 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2562 {
2563 struct inet_peer_base *bp = net->ipv4.peers;
2564
2565 net->ipv4.peers = NULL;
2566 inetpeer_invalidate_tree(bp);
2567 kfree(bp);
2568 }
2569
2570 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2571 .init = ipv4_inetpeer_init,
2572 .exit = ipv4_inetpeer_exit,
2573 };
2574
2575 #ifdef CONFIG_IP_ROUTE_CLASSID
2576 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2577 #endif /* CONFIG_IP_ROUTE_CLASSID */
2578
2579 int __init ip_rt_init(void)
2580 {
2581 int rc = 0;
2582
2583 #ifdef CONFIG_IP_ROUTE_CLASSID
2584 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2585 if (!ip_rt_acct)
2586 panic("IP: failed to allocate ip_rt_acct\n");
2587 #endif
2588
2589 ipv4_dst_ops.kmem_cachep =
2590 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2591 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2592
2593 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2594
2595 if (dst_entries_init(&ipv4_dst_ops) < 0)
2596 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2597
2598 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2599 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2600
2601 ipv4_dst_ops.gc_thresh = ~0;
2602 ip_rt_max_size = INT_MAX;
2603
2604 devinet_init();
2605 ip_fib_init();
2606
2607 if (ip_rt_proc_init())
2608 pr_err("Unable to create route proc files\n");
2609 #ifdef CONFIG_XFRM
2610 xfrm_init();
2611 xfrm4_init(ip_rt_max_size);
2612 #endif
2613 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2614
2615 #ifdef CONFIG_SYSCTL
2616 register_pernet_subsys(&sysctl_route_ops);
2617 #endif
2618 register_pernet_subsys(&rt_genid_ops);
2619 register_pernet_subsys(&ipv4_inetpeer_ops);
2620 return rc;
2621 }
2622
2623 #ifdef CONFIG_SYSCTL
2624 /*
2625 * We really need to sanitize the damn ipv4 init order, then all
2626 * this nonsense will go away.
2627 */
2628 void __init ip_static_sysctl_init(void)
2629 {
2630 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2631 }
2632 #endif
Linux kernel - Deliverables
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