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Merge branch 'for-3.11' of git://linux-nfs.org/~bfields/linux
[linux-2.6.git] / net / ipv4 / route.c
bloba9a54a2368323243be30f536d45646d48ec6c42d
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_redirect_number __read_mostly = 9;
121 static int ip_rt_redirect_load __read_mostly = HZ / 50;
122 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
123 static int ip_rt_error_cost __read_mostly = HZ;
124 static int ip_rt_error_burst __read_mostly = 5 * HZ;
125 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
126 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
127 static int ip_rt_min_advmss __read_mostly = 256;
128
129 /*
130 * Interface to generic destination cache.
131 */
132
133 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
134 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
135 static unsigned int ipv4_mtu(const struct dst_entry *dst);
136 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
137 static void ipv4_link_failure(struct sk_buff *skb);
138 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
139 struct sk_buff *skb, u32 mtu);
140 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
141 struct sk_buff *skb);
142 static void ipv4_dst_destroy(struct dst_entry *dst);
143
144 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
145 int how)
146 {
147 }
148
149 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
150 {
151 WARN_ON(1);
152 return NULL;
153 }
154
155 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
156 struct sk_buff *skb,
157 const void *daddr);
158
159 static struct dst_ops ipv4_dst_ops = {
160 .family = AF_INET,
161 .protocol = cpu_to_be16(ETH_P_IP),
162 .check = ipv4_dst_check,
163 .default_advmss = ipv4_default_advmss,
164 .mtu = ipv4_mtu,
165 .cow_metrics = ipv4_cow_metrics,
166 .destroy = ipv4_dst_destroy,
167 .ifdown = ipv4_dst_ifdown,
168 .negative_advice = ipv4_negative_advice,
169 .link_failure = ipv4_link_failure,
170 .update_pmtu = ip_rt_update_pmtu,
171 .redirect = ip_do_redirect,
172 .local_out = __ip_local_out,
173 .neigh_lookup = ipv4_neigh_lookup,
174 };
175
176 #define ECN_OR_COST(class) TC_PRIO_##class
177
178 const __u8 ip_tos2prio[16] = {
179 TC_PRIO_BESTEFFORT,
180 ECN_OR_COST(BESTEFFORT),
181 TC_PRIO_BESTEFFORT,
182 ECN_OR_COST(BESTEFFORT),
183 TC_PRIO_BULK,
184 ECN_OR_COST(BULK),
185 TC_PRIO_BULK,
186 ECN_OR_COST(BULK),
187 TC_PRIO_INTERACTIVE,
188 ECN_OR_COST(INTERACTIVE),
189 TC_PRIO_INTERACTIVE,
190 ECN_OR_COST(INTERACTIVE),
191 TC_PRIO_INTERACTIVE_BULK,
192 ECN_OR_COST(INTERACTIVE_BULK),
193 TC_PRIO_INTERACTIVE_BULK,
194 ECN_OR_COST(INTERACTIVE_BULK)
195 };
196 EXPORT_SYMBOL(ip_tos2prio);
197
198 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
199 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
200
201 #ifdef CONFIG_PROC_FS
202 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
203 {
204 if (*pos)
205 return NULL;
206 return SEQ_START_TOKEN;
207 }
208
209 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
210 {
211 ++*pos;
212 return NULL;
213 }
214
215 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
216 {
217 }
218
219 static int rt_cache_seq_show(struct seq_file *seq, void *v)
220 {
221 if (v == SEQ_START_TOKEN)
222 seq_printf(seq, "%-127s\n",
223 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
224 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
225 "HHUptod\tSpecDst");
226 return 0;
227 }
228
229 static const struct seq_operations rt_cache_seq_ops = {
230 .start = rt_cache_seq_start,
231 .next = rt_cache_seq_next,
232 .stop = rt_cache_seq_stop,
233 .show = rt_cache_seq_show,
234 };
235
236 static int rt_cache_seq_open(struct inode *inode, struct file *file)
237 {
238 return seq_open(file, &rt_cache_seq_ops);
239 }
240
241 static const struct file_operations rt_cache_seq_fops = {
242 .owner = THIS_MODULE,
243 .open = rt_cache_seq_open,
244 .read = seq_read,
245 .llseek = seq_lseek,
246 .release = seq_release,
247 };
248
249
250 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
251 {
252 int cpu;
253
254 if (*pos == 0)
255 return SEQ_START_TOKEN;
256
257 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
258 if (!cpu_possible(cpu))
259 continue;
260 *pos = cpu+1;
261 return &per_cpu(rt_cache_stat, cpu);
262 }
263 return NULL;
264 }
265
266 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
267 {
268 int cpu;
269
270 for (cpu = *pos; 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
280 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
281 {
282
283 }
284
285 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
286 {
287 struct rt_cache_stat *st = v;
288
289 if (v == SEQ_START_TOKEN) {
290 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");
291 return 0;
292 }
293
294 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
295 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
296 dst_entries_get_slow(&ipv4_dst_ops),
297 st->in_hit,
298 st->in_slow_tot,
299 st->in_slow_mc,
300 st->in_no_route,
301 st->in_brd,
302 st->in_martian_dst,
303 st->in_martian_src,
304
305 st->out_hit,
306 st->out_slow_tot,
307 st->out_slow_mc,
308
309 st->gc_total,
310 st->gc_ignored,
311 st->gc_goal_miss,
312 st->gc_dst_overflow,
313 st->in_hlist_search,
314 st->out_hlist_search
315 );
316 return 0;
317 }
318
319 static const struct seq_operations rt_cpu_seq_ops = {
320 .start = rt_cpu_seq_start,
321 .next = rt_cpu_seq_next,
322 .stop = rt_cpu_seq_stop,
323 .show = rt_cpu_seq_show,
324 };
325
326
327 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
328 {
329 return seq_open(file, &rt_cpu_seq_ops);
330 }
331
332 static const struct file_operations rt_cpu_seq_fops = {
333 .owner = THIS_MODULE,
334 .open = rt_cpu_seq_open,
335 .read = seq_read,
336 .llseek = seq_lseek,
337 .release = seq_release,
338 };
339
340 #ifdef CONFIG_IP_ROUTE_CLASSID
341 static int rt_acct_proc_show(struct seq_file *m, void *v)
342 {
343 struct ip_rt_acct *dst, *src;
344 unsigned int i, j;
345
346 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
347 if (!dst)
348 return -ENOMEM;
349
350 for_each_possible_cpu(i) {
351 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
352 for (j = 0; j < 256; j++) {
353 dst[j].o_bytes += src[j].o_bytes;
354 dst[j].o_packets += src[j].o_packets;
355 dst[j].i_bytes += src[j].i_bytes;
356 dst[j].i_packets += src[j].i_packets;
357 }
358 }
359
360 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
361 kfree(dst);
362 return 0;
363 }
364
365 static int rt_acct_proc_open(struct inode *inode, struct file *file)
366 {
367 return single_open(file, rt_acct_proc_show, NULL);
368 }
369
370 static const struct file_operations rt_acct_proc_fops = {
371 .owner = THIS_MODULE,
372 .open = rt_acct_proc_open,
373 .read = seq_read,
374 .llseek = seq_lseek,
375 .release = single_release,
376 };
377 #endif
378
379 static int __net_init ip_rt_do_proc_init(struct net *net)
380 {
381 struct proc_dir_entry *pde;
382
383 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
384 &rt_cache_seq_fops);
385 if (!pde)
386 goto err1;
387
388 pde = proc_create("rt_cache", S_IRUGO,
389 net->proc_net_stat, &rt_cpu_seq_fops);
390 if (!pde)
391 goto err2;
392
393 #ifdef CONFIG_IP_ROUTE_CLASSID
394 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
395 if (!pde)
396 goto err3;
397 #endif
398 return 0;
399
400 #ifdef CONFIG_IP_ROUTE_CLASSID
401 err3:
402 remove_proc_entry("rt_cache", net->proc_net_stat);
403 #endif
404 err2:
405 remove_proc_entry("rt_cache", net->proc_net);
406 err1:
407 return -ENOMEM;
408 }
409
410 static void __net_exit ip_rt_do_proc_exit(struct net *net)
411 {
412 remove_proc_entry("rt_cache", net->proc_net_stat);
413 remove_proc_entry("rt_cache", net->proc_net);
414 #ifdef CONFIG_IP_ROUTE_CLASSID
415 remove_proc_entry("rt_acct", net->proc_net);
416 #endif
417 }
418
419 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
420 .init = ip_rt_do_proc_init,
421 .exit = ip_rt_do_proc_exit,
422 };
423
424 static int __init ip_rt_proc_init(void)
425 {
426 return register_pernet_subsys(&ip_rt_proc_ops);
427 }
428
429 #else
430 static inline int ip_rt_proc_init(void)
431 {
432 return 0;
433 }
434 #endif /* CONFIG_PROC_FS */
435
436 static inline bool rt_is_expired(const struct rtable *rth)
437 {
438 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
439 }
440
441 void rt_cache_flush(struct net *net)
442 {
443 rt_genid_bump(net);
444 }
445
446 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
447 struct sk_buff *skb,
448 const void *daddr)
449 {
450 struct net_device *dev = dst->dev;
451 const __be32 *pkey = daddr;
452 const struct rtable *rt;
453 struct neighbour *n;
454
455 rt = (const struct rtable *) dst;
456 if (rt->rt_gateway)
457 pkey = (const __be32 *) &rt->rt_gateway;
458 else if (skb)
459 pkey = &ip_hdr(skb)->daddr;
460
461 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
462 if (n)
463 return n;
464 return neigh_create(&arp_tbl, pkey, dev);
465 }
466
467 /*
468 * Peer allocation may fail only in serious out-of-memory conditions. However
469 * we still can generate some output.
470 * Random ID selection looks a bit dangerous because we have no chances to
471 * select ID being unique in a reasonable period of time.
472 * But broken packet identifier may be better than no packet at all.
473 */
474 static void ip_select_fb_ident(struct iphdr *iph)
475 {
476 static DEFINE_SPINLOCK(ip_fb_id_lock);
477 static u32 ip_fallback_id;
478 u32 salt;
479
480 spin_lock_bh(&ip_fb_id_lock);
481 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
482 iph->id = htons(salt & 0xFFFF);
483 ip_fallback_id = salt;
484 spin_unlock_bh(&ip_fb_id_lock);
485 }
486
487 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
488 {
489 struct net *net = dev_net(dst->dev);
490 struct inet_peer *peer;
491
492 peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1);
493 if (peer) {
494 iph->id = htons(inet_getid(peer, more));
495 inet_putpeer(peer);
496 return;
497 }
498
499 ip_select_fb_ident(iph);
500 }
501 EXPORT_SYMBOL(__ip_select_ident);
502
503 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
504 const struct iphdr *iph,
505 int oif, u8 tos,
506 u8 prot, u32 mark, int flow_flags)
507 {
508 if (sk) {
509 const struct inet_sock *inet = inet_sk(sk);
510
511 oif = sk->sk_bound_dev_if;
512 mark = sk->sk_mark;
513 tos = RT_CONN_FLAGS(sk);
514 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
515 }
516 flowi4_init_output(fl4, oif, mark, tos,
517 RT_SCOPE_UNIVERSE, prot,
518 flow_flags,
519 iph->daddr, iph->saddr, 0, 0);
520 }
521
522 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
523 const struct sock *sk)
524 {
525 const struct iphdr *iph = ip_hdr(skb);
526 int oif = skb->dev->ifindex;
527 u8 tos = RT_TOS(iph->tos);
528 u8 prot = iph->protocol;
529 u32 mark = skb->mark;
530
531 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
532 }
533
534 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
535 {
536 const struct inet_sock *inet = inet_sk(sk);
537 const struct ip_options_rcu *inet_opt;
538 __be32 daddr = inet->inet_daddr;
539
540 rcu_read_lock();
541 inet_opt = rcu_dereference(inet->inet_opt);
542 if (inet_opt && inet_opt->opt.srr)
543 daddr = inet_opt->opt.faddr;
544 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
545 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
546 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
547 inet_sk_flowi_flags(sk),
548 daddr, inet->inet_saddr, 0, 0);
549 rcu_read_unlock();
550 }
551
552 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
553 const struct sk_buff *skb)
554 {
555 if (skb)
556 build_skb_flow_key(fl4, skb, sk);
557 else
558 build_sk_flow_key(fl4, sk);
559 }
560
561 static inline void rt_free(struct rtable *rt)
562 {
563 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
564 }
565
566 static DEFINE_SPINLOCK(fnhe_lock);
567
568 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
569 {
570 struct rtable *rt;
571
572 rt = rcu_dereference(fnhe->fnhe_rth_input);
573 if (rt) {
574 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
575 rt_free(rt);
576 }
577 rt = rcu_dereference(fnhe->fnhe_rth_output);
578 if (rt) {
579 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
580 rt_free(rt);
581 }
582 }
583
584 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
585 {
586 struct fib_nh_exception *fnhe, *oldest;
587
588 oldest = rcu_dereference(hash->chain);
589 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
590 fnhe = rcu_dereference(fnhe->fnhe_next)) {
591 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
592 oldest = fnhe;
593 }
594 fnhe_flush_routes(oldest);
595 return oldest;
596 }
597
598 static inline u32 fnhe_hashfun(__be32 daddr)
599 {
600 u32 hval;
601
602 hval = (__force u32) daddr;
603 hval ^= (hval >> 11) ^ (hval >> 22);
604
605 return hval & (FNHE_HASH_SIZE - 1);
606 }
607
608 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
609 {
610 rt->rt_pmtu = fnhe->fnhe_pmtu;
611 rt->dst.expires = fnhe->fnhe_expires;
612
613 if (fnhe->fnhe_gw) {
614 rt->rt_flags |= RTCF_REDIRECTED;
615 rt->rt_gateway = fnhe->fnhe_gw;
616 rt->rt_uses_gateway = 1;
617 }
618 }
619
620 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
621 u32 pmtu, unsigned long expires)
622 {
623 struct fnhe_hash_bucket *hash;
624 struct fib_nh_exception *fnhe;
625 struct rtable *rt;
626 unsigned int i;
627 int depth;
628 u32 hval = fnhe_hashfun(daddr);
629
630 spin_lock_bh(&fnhe_lock);
631
632 hash = nh->nh_exceptions;
633 if (!hash) {
634 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
635 if (!hash)
636 goto out_unlock;
637 nh->nh_exceptions = hash;
638 }
639
640 hash += hval;
641
642 depth = 0;
643 for (fnhe = rcu_dereference(hash->chain); fnhe;
644 fnhe = rcu_dereference(fnhe->fnhe_next)) {
645 if (fnhe->fnhe_daddr == daddr)
646 break;
647 depth++;
648 }
649
650 if (fnhe) {
651 if (gw)
652 fnhe->fnhe_gw = gw;
653 if (pmtu) {
654 fnhe->fnhe_pmtu = pmtu;
655 fnhe->fnhe_expires = max(1UL, expires);
656 }
657 /* Update all cached dsts too */
658 rt = rcu_dereference(fnhe->fnhe_rth_input);
659 if (rt)
660 fill_route_from_fnhe(rt, fnhe);
661 rt = rcu_dereference(fnhe->fnhe_rth_output);
662 if (rt)
663 fill_route_from_fnhe(rt, fnhe);
664 } else {
665 if (depth > FNHE_RECLAIM_DEPTH)
666 fnhe = fnhe_oldest(hash);
667 else {
668 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
669 if (!fnhe)
670 goto out_unlock;
671
672 fnhe->fnhe_next = hash->chain;
673 rcu_assign_pointer(hash->chain, fnhe);
674 }
675 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
676 fnhe->fnhe_daddr = daddr;
677 fnhe->fnhe_gw = gw;
678 fnhe->fnhe_pmtu = pmtu;
679 fnhe->fnhe_expires = expires;
680
681 /* Exception created; mark the cached routes for the nexthop
682 * stale, so anyone caching it rechecks if this exception
683 * applies to them.
684 */
685 rt = rcu_dereference(nh->nh_rth_input);
686 if (rt)
687 rt->dst.obsolete = DST_OBSOLETE_KILL;
688
689 for_each_possible_cpu(i) {
690 struct rtable __rcu **prt;
691 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
692 rt = rcu_dereference(*prt);
693 if (rt)
694 rt->dst.obsolete = DST_OBSOLETE_KILL;
695 }
696 }
697
698 fnhe->fnhe_stamp = jiffies;
699
700 out_unlock:
701 spin_unlock_bh(&fnhe_lock);
702 return;
703 }
704
705 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
706 bool kill_route)
707 {
708 __be32 new_gw = icmp_hdr(skb)->un.gateway;
709 __be32 old_gw = ip_hdr(skb)->saddr;
710 struct net_device *dev = skb->dev;
711 struct in_device *in_dev;
712 struct fib_result res;
713 struct neighbour *n;
714 struct net *net;
715
716 switch (icmp_hdr(skb)->code & 7) {
717 case ICMP_REDIR_NET:
718 case ICMP_REDIR_NETTOS:
719 case ICMP_REDIR_HOST:
720 case ICMP_REDIR_HOSTTOS:
721 break;
722
723 default:
724 return;
725 }
726
727 if (rt->rt_gateway != old_gw)
728 return;
729
730 in_dev = __in_dev_get_rcu(dev);
731 if (!in_dev)
732 return;
733
734 net = dev_net(dev);
735 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
736 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
737 ipv4_is_zeronet(new_gw))
738 goto reject_redirect;
739
740 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
741 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
742 goto reject_redirect;
743 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
744 goto reject_redirect;
745 } else {
746 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
747 goto reject_redirect;
748 }
749
750 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
751 if (n) {
752 if (!(n->nud_state & NUD_VALID)) {
753 neigh_event_send(n, NULL);
754 } else {
755 if (fib_lookup(net, fl4, &res) == 0) {
756 struct fib_nh *nh = &FIB_RES_NH(res);
757
758 update_or_create_fnhe(nh, fl4->daddr, new_gw,
759 0, 0);
760 }
761 if (kill_route)
762 rt->dst.obsolete = DST_OBSOLETE_KILL;
763 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
764 }
765 neigh_release(n);
766 }
767 return;
768
769 reject_redirect:
770 #ifdef CONFIG_IP_ROUTE_VERBOSE
771 if (IN_DEV_LOG_MARTIANS(in_dev)) {
772 const struct iphdr *iph = (const struct iphdr *) skb->data;
773 __be32 daddr = iph->daddr;
774 __be32 saddr = iph->saddr;
775
776 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
777 " Advised path = %pI4 -> %pI4\n",
778 &old_gw, dev->name, &new_gw,
779 &saddr, &daddr);
780 }
781 #endif
782 ;
783 }
784
785 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
786 {
787 struct rtable *rt;
788 struct flowi4 fl4;
789 const struct iphdr *iph = (const struct iphdr *) skb->data;
790 int oif = skb->dev->ifindex;
791 u8 tos = RT_TOS(iph->tos);
792 u8 prot = iph->protocol;
793 u32 mark = skb->mark;
794
795 rt = (struct rtable *) dst;
796
797 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
798 __ip_do_redirect(rt, skb, &fl4, true);
799 }
800
801 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
802 {
803 struct rtable *rt = (struct rtable *)dst;
804 struct dst_entry *ret = dst;
805
806 if (rt) {
807 if (dst->obsolete > 0) {
808 ip_rt_put(rt);
809 ret = NULL;
810 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
811 rt->dst.expires) {
812 ip_rt_put(rt);
813 ret = NULL;
814 }
815 }
816 return ret;
817 }
818
819 /*
820 * Algorithm:
821 * 1. The first ip_rt_redirect_number redirects are sent
822 * with exponential backoff, then we stop sending them at all,
823 * assuming that the host ignores our redirects.
824 * 2. If we did not see packets requiring redirects
825 * during ip_rt_redirect_silence, we assume that the host
826 * forgot redirected route and start to send redirects again.
827 *
828 * This algorithm is much cheaper and more intelligent than dumb load limiting
829 * in icmp.c.
830 *
831 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
832 * and "frag. need" (breaks PMTU discovery) in icmp.c.
833 */
834
835 void ip_rt_send_redirect(struct sk_buff *skb)
836 {
837 struct rtable *rt = skb_rtable(skb);
838 struct in_device *in_dev;
839 struct inet_peer *peer;
840 struct net *net;
841 int log_martians;
842
843 rcu_read_lock();
844 in_dev = __in_dev_get_rcu(rt->dst.dev);
845 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
846 rcu_read_unlock();
847 return;
848 }
849 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
850 rcu_read_unlock();
851
852 net = dev_net(rt->dst.dev);
853 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
854 if (!peer) {
855 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
856 rt_nexthop(rt, ip_hdr(skb)->daddr));
857 return;
858 }
859
860 /* No redirected packets during ip_rt_redirect_silence;
861 * reset the algorithm.
862 */
863 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
864 peer->rate_tokens = 0;
865
866 /* Too many ignored redirects; do not send anything
867 * set dst.rate_last to the last seen redirected packet.
868 */
869 if (peer->rate_tokens >= ip_rt_redirect_number) {
870 peer->rate_last = jiffies;
871 goto out_put_peer;
872 }
873
874 /* Check for load limit; set rate_last to the latest sent
875 * redirect.
876 */
877 if (peer->rate_tokens == 0 ||
878 time_after(jiffies,
879 (peer->rate_last +
880 (ip_rt_redirect_load << peer->rate_tokens)))) {
881 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
882
883 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
884 peer->rate_last = jiffies;
885 ++peer->rate_tokens;
886 #ifdef CONFIG_IP_ROUTE_VERBOSE
887 if (log_martians &&
888 peer->rate_tokens == ip_rt_redirect_number)
889 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
890 &ip_hdr(skb)->saddr, inet_iif(skb),
891 &ip_hdr(skb)->daddr, &gw);
892 #endif
893 }
894 out_put_peer:
895 inet_putpeer(peer);
896 }
897
898 static int ip_error(struct sk_buff *skb)
899 {
900 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
901 struct rtable *rt = skb_rtable(skb);
902 struct inet_peer *peer;
903 unsigned long now;
904 struct net *net;
905 bool send;
906 int code;
907
908 net = dev_net(rt->dst.dev);
909 if (!IN_DEV_FORWARD(in_dev)) {
910 switch (rt->dst.error) {
911 case EHOSTUNREACH:
912 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
913 break;
914
915 case ENETUNREACH:
916 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
917 break;
918 }
919 goto out;
920 }
921
922 switch (rt->dst.error) {
923 case EINVAL:
924 default:
925 goto out;
926 case EHOSTUNREACH:
927 code = ICMP_HOST_UNREACH;
928 break;
929 case ENETUNREACH:
930 code = ICMP_NET_UNREACH;
931 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
932 break;
933 case EACCES:
934 code = ICMP_PKT_FILTERED;
935 break;
936 }
937
938 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
939
940 send = true;
941 if (peer) {
942 now = jiffies;
943 peer->rate_tokens += now - peer->rate_last;
944 if (peer->rate_tokens > ip_rt_error_burst)
945 peer->rate_tokens = ip_rt_error_burst;
946 peer->rate_last = now;
947 if (peer->rate_tokens >= ip_rt_error_cost)
948 peer->rate_tokens -= ip_rt_error_cost;
949 else
950 send = false;
951 inet_putpeer(peer);
952 }
953 if (send)
954 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
955
956 out: kfree_skb(skb);
957 return 0;
958 }
959
960 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
961 {
962 struct dst_entry *dst = &rt->dst;
963 struct fib_result res;
964
965 if (dst_metric_locked(dst, RTAX_MTU))
966 return;
967
968 if (dst->dev->mtu < mtu)
969 return;
970
971 if (mtu < ip_rt_min_pmtu)
972 mtu = ip_rt_min_pmtu;
973
974 if (rt->rt_pmtu == mtu &&
975 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
976 return;
977
978 rcu_read_lock();
979 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
980 struct fib_nh *nh = &FIB_RES_NH(res);
981
982 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
983 jiffies + ip_rt_mtu_expires);
984 }
985 rcu_read_unlock();
986 }
987
988 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
989 struct sk_buff *skb, u32 mtu)
990 {
991 struct rtable *rt = (struct rtable *) dst;
992 struct flowi4 fl4;
993
994 ip_rt_build_flow_key(&fl4, sk, skb);
995 __ip_rt_update_pmtu(rt, &fl4, mtu);
996 }
997
998 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
999 int oif, u32 mark, u8 protocol, int flow_flags)
1000 {
1001 const struct iphdr *iph = (const struct iphdr *) skb->data;
1002 struct flowi4 fl4;
1003 struct rtable *rt;
1004
1005 __build_flow_key(&fl4, NULL, iph, oif,
1006 RT_TOS(iph->tos), protocol, mark, flow_flags);
1007 rt = __ip_route_output_key(net, &fl4);
1008 if (!IS_ERR(rt)) {
1009 __ip_rt_update_pmtu(rt, &fl4, mtu);
1010 ip_rt_put(rt);
1011 }
1012 }
1013 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1014
1015 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1016 {
1017 const struct iphdr *iph = (const struct iphdr *) skb->data;
1018 struct flowi4 fl4;
1019 struct rtable *rt;
1020
1021 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1022 rt = __ip_route_output_key(sock_net(sk), &fl4);
1023 if (!IS_ERR(rt)) {
1024 __ip_rt_update_pmtu(rt, &fl4, mtu);
1025 ip_rt_put(rt);
1026 }
1027 }
1028
1029 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1030 {
1031 const struct iphdr *iph = (const struct iphdr *) skb->data;
1032 struct flowi4 fl4;
1033 struct rtable *rt;
1034 struct dst_entry *dst;
1035 bool new = false;
1036
1037 bh_lock_sock(sk);
1038 rt = (struct rtable *) __sk_dst_get(sk);
1039
1040 if (sock_owned_by_user(sk) || !rt) {
1041 __ipv4_sk_update_pmtu(skb, sk, mtu);
1042 goto out;
1043 }
1044
1045 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1046
1047 if (!__sk_dst_check(sk, 0)) {
1048 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1049 if (IS_ERR(rt))
1050 goto out;
1051
1052 new = true;
1053 }
1054
1055 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1056
1057 dst = dst_check(&rt->dst, 0);
1058 if (!dst) {
1059 if (new)
1060 dst_release(&rt->dst);
1061
1062 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1063 if (IS_ERR(rt))
1064 goto out;
1065
1066 new = true;
1067 }
1068
1069 if (new)
1070 __sk_dst_set(sk, &rt->dst);
1071
1072 out:
1073 bh_unlock_sock(sk);
1074 }
1075 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1076
1077 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1078 int oif, u32 mark, u8 protocol, int flow_flags)
1079 {
1080 const struct iphdr *iph = (const struct iphdr *) skb->data;
1081 struct flowi4 fl4;
1082 struct rtable *rt;
1083
1084 __build_flow_key(&fl4, NULL, iph, oif,
1085 RT_TOS(iph->tos), protocol, mark, flow_flags);
1086 rt = __ip_route_output_key(net, &fl4);
1087 if (!IS_ERR(rt)) {
1088 __ip_do_redirect(rt, skb, &fl4, false);
1089 ip_rt_put(rt);
1090 }
1091 }
1092 EXPORT_SYMBOL_GPL(ipv4_redirect);
1093
1094 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1095 {
1096 const struct iphdr *iph = (const struct iphdr *) skb->data;
1097 struct flowi4 fl4;
1098 struct rtable *rt;
1099
1100 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1101 rt = __ip_route_output_key(sock_net(sk), &fl4);
1102 if (!IS_ERR(rt)) {
1103 __ip_do_redirect(rt, skb, &fl4, false);
1104 ip_rt_put(rt);
1105 }
1106 }
1107 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1108
1109 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1110 {
1111 struct rtable *rt = (struct rtable *) dst;
1112
1113 /* All IPV4 dsts are created with ->obsolete set to the value
1114 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1115 * into this function always.
1116 *
1117 * When a PMTU/redirect information update invalidates a route,
1118 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1119 * DST_OBSOLETE_DEAD by dst_free().
1120 */
1121 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1122 return NULL;
1123 return dst;
1124 }
1125
1126 static void ipv4_link_failure(struct sk_buff *skb)
1127 {
1128 struct rtable *rt;
1129
1130 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1131
1132 rt = skb_rtable(skb);
1133 if (rt)
1134 dst_set_expires(&rt->dst, 0);
1135 }
1136
1137 static int ip_rt_bug(struct sk_buff *skb)
1138 {
1139 pr_debug("%s: %pI4 -> %pI4, %s\n",
1140 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1141 skb->dev ? skb->dev->name : "?");
1142 kfree_skb(skb);
1143 WARN_ON(1);
1144 return 0;
1145 }
1146
1147 /*
1148 We do not cache source address of outgoing interface,
1149 because it is used only by IP RR, TS and SRR options,
1150 so that it out of fast path.
1151
1152 BTW remember: "addr" is allowed to be not aligned
1153 in IP options!
1154 */
1155
1156 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1157 {
1158 __be32 src;
1159
1160 if (rt_is_output_route(rt))
1161 src = ip_hdr(skb)->saddr;
1162 else {
1163 struct fib_result res;
1164 struct flowi4 fl4;
1165 struct iphdr *iph;
1166
1167 iph = ip_hdr(skb);
1168
1169 memset(&fl4, 0, sizeof(fl4));
1170 fl4.daddr = iph->daddr;
1171 fl4.saddr = iph->saddr;
1172 fl4.flowi4_tos = RT_TOS(iph->tos);
1173 fl4.flowi4_oif = rt->dst.dev->ifindex;
1174 fl4.flowi4_iif = skb->dev->ifindex;
1175 fl4.flowi4_mark = skb->mark;
1176
1177 rcu_read_lock();
1178 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1179 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1180 else
1181 src = inet_select_addr(rt->dst.dev,
1182 rt_nexthop(rt, iph->daddr),
1183 RT_SCOPE_UNIVERSE);
1184 rcu_read_unlock();
1185 }
1186 memcpy(addr, &src, 4);
1187 }
1188
1189 #ifdef CONFIG_IP_ROUTE_CLASSID
1190 static void set_class_tag(struct rtable *rt, u32 tag)
1191 {
1192 if (!(rt->dst.tclassid & 0xFFFF))
1193 rt->dst.tclassid |= tag & 0xFFFF;
1194 if (!(rt->dst.tclassid & 0xFFFF0000))
1195 rt->dst.tclassid |= tag & 0xFFFF0000;
1196 }
1197 #endif
1198
1199 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1200 {
1201 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1202
1203 if (advmss == 0) {
1204 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1205 ip_rt_min_advmss);
1206 if (advmss > 65535 - 40)
1207 advmss = 65535 - 40;
1208 }
1209 return advmss;
1210 }
1211
1212 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1213 {
1214 const struct rtable *rt = (const struct rtable *) dst;
1215 unsigned int mtu = rt->rt_pmtu;
1216
1217 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1218 mtu = dst_metric_raw(dst, RTAX_MTU);
1219
1220 if (mtu)
1221 return mtu;
1222
1223 mtu = dst->dev->mtu;
1224
1225 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1226 if (rt->rt_uses_gateway && mtu > 576)
1227 mtu = 576;
1228 }
1229
1230 if (mtu > IP_MAX_MTU)
1231 mtu = IP_MAX_MTU;
1232
1233 return mtu;
1234 }
1235
1236 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1237 {
1238 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1239 struct fib_nh_exception *fnhe;
1240 u32 hval;
1241
1242 if (!hash)
1243 return NULL;
1244
1245 hval = fnhe_hashfun(daddr);
1246
1247 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1248 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1249 if (fnhe->fnhe_daddr == daddr)
1250 return fnhe;
1251 }
1252 return NULL;
1253 }
1254
1255 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1256 __be32 daddr)
1257 {
1258 bool ret = false;
1259
1260 spin_lock_bh(&fnhe_lock);
1261
1262 if (daddr == fnhe->fnhe_daddr) {
1263 struct rtable __rcu **porig;
1264 struct rtable *orig;
1265 int genid = fnhe_genid(dev_net(rt->dst.dev));
1266
1267 if (rt_is_input_route(rt))
1268 porig = &fnhe->fnhe_rth_input;
1269 else
1270 porig = &fnhe->fnhe_rth_output;
1271 orig = rcu_dereference(*porig);
1272
1273 if (fnhe->fnhe_genid != genid) {
1274 fnhe->fnhe_genid = genid;
1275 fnhe->fnhe_gw = 0;
1276 fnhe->fnhe_pmtu = 0;
1277 fnhe->fnhe_expires = 0;
1278 fnhe_flush_routes(fnhe);
1279 orig = NULL;
1280 }
1281 fill_route_from_fnhe(rt, fnhe);
1282 if (!rt->rt_gateway)
1283 rt->rt_gateway = daddr;
1284
1285 if (!(rt->dst.flags & DST_NOCACHE)) {
1286 rcu_assign_pointer(*porig, rt);
1287 if (orig)
1288 rt_free(orig);
1289 ret = true;
1290 }
1291
1292 fnhe->fnhe_stamp = jiffies;
1293 }
1294 spin_unlock_bh(&fnhe_lock);
1295
1296 return ret;
1297 }
1298
1299 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1300 {
1301 struct rtable *orig, *prev, **p;
1302 bool ret = true;
1303
1304 if (rt_is_input_route(rt)) {
1305 p = (struct rtable **)&nh->nh_rth_input;
1306 } else {
1307 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1308 }
1309 orig = *p;
1310
1311 prev = cmpxchg(p, orig, rt);
1312 if (prev == orig) {
1313 if (orig)
1314 rt_free(orig);
1315 } else
1316 ret = false;
1317
1318 return ret;
1319 }
1320
1321 static DEFINE_SPINLOCK(rt_uncached_lock);
1322 static LIST_HEAD(rt_uncached_list);
1323
1324 static void rt_add_uncached_list(struct rtable *rt)
1325 {
1326 spin_lock_bh(&rt_uncached_lock);
1327 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1328 spin_unlock_bh(&rt_uncached_lock);
1329 }
1330
1331 static void ipv4_dst_destroy(struct dst_entry *dst)
1332 {
1333 struct rtable *rt = (struct rtable *) dst;
1334
1335 if (!list_empty(&rt->rt_uncached)) {
1336 spin_lock_bh(&rt_uncached_lock);
1337 list_del(&rt->rt_uncached);
1338 spin_unlock_bh(&rt_uncached_lock);
1339 }
1340 }
1341
1342 void rt_flush_dev(struct net_device *dev)
1343 {
1344 if (!list_empty(&rt_uncached_list)) {
1345 struct net *net = dev_net(dev);
1346 struct rtable *rt;
1347
1348 spin_lock_bh(&rt_uncached_lock);
1349 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1350 if (rt->dst.dev != dev)
1351 continue;
1352 rt->dst.dev = net->loopback_dev;
1353 dev_hold(rt->dst.dev);
1354 dev_put(dev);
1355 }
1356 spin_unlock_bh(&rt_uncached_lock);
1357 }
1358 }
1359
1360 static bool rt_cache_valid(const struct rtable *rt)
1361 {
1362 return rt &&
1363 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1364 !rt_is_expired(rt);
1365 }
1366
1367 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1368 const struct fib_result *res,
1369 struct fib_nh_exception *fnhe,
1370 struct fib_info *fi, u16 type, u32 itag)
1371 {
1372 bool cached = false;
1373
1374 if (fi) {
1375 struct fib_nh *nh = &FIB_RES_NH(*res);
1376
1377 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1378 rt->rt_gateway = nh->nh_gw;
1379 rt->rt_uses_gateway = 1;
1380 }
1381 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1382 #ifdef CONFIG_IP_ROUTE_CLASSID
1383 rt->dst.tclassid = nh->nh_tclassid;
1384 #endif
1385 if (unlikely(fnhe))
1386 cached = rt_bind_exception(rt, fnhe, daddr);
1387 else if (!(rt->dst.flags & DST_NOCACHE))
1388 cached = rt_cache_route(nh, rt);
1389 if (unlikely(!cached)) {
1390 /* Routes we intend to cache in nexthop exception or
1391 * FIB nexthop have the DST_NOCACHE bit clear.
1392 * However, if we are unsuccessful at storing this
1393 * route into the cache we really need to set it.
1394 */
1395 rt->dst.flags |= DST_NOCACHE;
1396 if (!rt->rt_gateway)
1397 rt->rt_gateway = daddr;
1398 rt_add_uncached_list(rt);
1399 }
1400 } else
1401 rt_add_uncached_list(rt);
1402
1403 #ifdef CONFIG_IP_ROUTE_CLASSID
1404 #ifdef CONFIG_IP_MULTIPLE_TABLES
1405 set_class_tag(rt, res->tclassid);
1406 #endif
1407 set_class_tag(rt, itag);
1408 #endif
1409 }
1410
1411 static struct rtable *rt_dst_alloc(struct net_device *dev,
1412 bool nopolicy, bool noxfrm, bool will_cache)
1413 {
1414 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1415 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1416 (nopolicy ? DST_NOPOLICY : 0) |
1417 (noxfrm ? DST_NOXFRM : 0));
1418 }
1419
1420 /* called in rcu_read_lock() section */
1421 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1422 u8 tos, struct net_device *dev, int our)
1423 {
1424 struct rtable *rth;
1425 struct in_device *in_dev = __in_dev_get_rcu(dev);
1426 u32 itag = 0;
1427 int err;
1428
1429 /* Primary sanity checks. */
1430
1431 if (in_dev == NULL)
1432 return -EINVAL;
1433
1434 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1435 skb->protocol != htons(ETH_P_IP))
1436 goto e_inval;
1437
1438 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1439 if (ipv4_is_loopback(saddr))
1440 goto e_inval;
1441
1442 if (ipv4_is_zeronet(saddr)) {
1443 if (!ipv4_is_local_multicast(daddr))
1444 goto e_inval;
1445 } else {
1446 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1447 in_dev, &itag);
1448 if (err < 0)
1449 goto e_err;
1450 }
1451 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1452 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1453 if (!rth)
1454 goto e_nobufs;
1455
1456 #ifdef CONFIG_IP_ROUTE_CLASSID
1457 rth->dst.tclassid = itag;
1458 #endif
1459 rth->dst.output = ip_rt_bug;
1460
1461 rth->rt_genid = rt_genid(dev_net(dev));
1462 rth->rt_flags = RTCF_MULTICAST;
1463 rth->rt_type = RTN_MULTICAST;
1464 rth->rt_is_input= 1;
1465 rth->rt_iif = 0;
1466 rth->rt_pmtu = 0;
1467 rth->rt_gateway = 0;
1468 rth->rt_uses_gateway = 0;
1469 INIT_LIST_HEAD(&rth->rt_uncached);
1470 if (our) {
1471 rth->dst.input= ip_local_deliver;
1472 rth->rt_flags |= RTCF_LOCAL;
1473 }
1474
1475 #ifdef CONFIG_IP_MROUTE
1476 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1477 rth->dst.input = ip_mr_input;
1478 #endif
1479 RT_CACHE_STAT_INC(in_slow_mc);
1480
1481 skb_dst_set(skb, &rth->dst);
1482 return 0;
1483
1484 e_nobufs:
1485 return -ENOBUFS;
1486 e_inval:
1487 return -EINVAL;
1488 e_err:
1489 return err;
1490 }
1491
1492
1493 static void ip_handle_martian_source(struct net_device *dev,
1494 struct in_device *in_dev,
1495 struct sk_buff *skb,
1496 __be32 daddr,
1497 __be32 saddr)
1498 {
1499 RT_CACHE_STAT_INC(in_martian_src);
1500 #ifdef CONFIG_IP_ROUTE_VERBOSE
1501 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1502 /*
1503 * RFC1812 recommendation, if source is martian,
1504 * the only hint is MAC header.
1505 */
1506 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1507 &daddr, &saddr, dev->name);
1508 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1509 print_hex_dump(KERN_WARNING, "ll header: ",
1510 DUMP_PREFIX_OFFSET, 16, 1,
1511 skb_mac_header(skb),
1512 dev->hard_header_len, true);
1513 }
1514 }
1515 #endif
1516 }
1517
1518 /* called in rcu_read_lock() section */
1519 static int __mkroute_input(struct sk_buff *skb,
1520 const struct fib_result *res,
1521 struct in_device *in_dev,
1522 __be32 daddr, __be32 saddr, u32 tos)
1523 {
1524 struct fib_nh_exception *fnhe;
1525 struct rtable *rth;
1526 int err;
1527 struct in_device *out_dev;
1528 unsigned int flags = 0;
1529 bool do_cache;
1530 u32 itag;
1531
1532 /* get a working reference to the output device */
1533 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1534 if (out_dev == NULL) {
1535 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1536 return -EINVAL;
1537 }
1538
1539 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1540 in_dev->dev, in_dev, &itag);
1541 if (err < 0) {
1542 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1543 saddr);
1544
1545 goto cleanup;
1546 }
1547
1548 do_cache = res->fi && !itag;
1549 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1550 (IN_DEV_SHARED_MEDIA(out_dev) ||
1551 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) {
1552 flags |= RTCF_DOREDIRECT;
1553 do_cache = false;
1554 }
1555
1556 if (skb->protocol != htons(ETH_P_IP)) {
1557 /* Not IP (i.e. ARP). Do not create route, if it is
1558 * invalid for proxy arp. DNAT routes are always valid.
1559 *
1560 * Proxy arp feature have been extended to allow, ARP
1561 * replies back to the same interface, to support
1562 * Private VLAN switch technologies. See arp.c.
1563 */
1564 if (out_dev == in_dev &&
1565 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1566 err = -EINVAL;
1567 goto cleanup;
1568 }
1569 }
1570
1571 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1572 if (do_cache) {
1573 if (fnhe != NULL)
1574 rth = rcu_dereference(fnhe->fnhe_rth_input);
1575 else
1576 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1577
1578 if (rt_cache_valid(rth)) {
1579 skb_dst_set_noref(skb, &rth->dst);
1580 goto out;
1581 }
1582 }
1583
1584 rth = rt_dst_alloc(out_dev->dev,
1585 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1586 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1587 if (!rth) {
1588 err = -ENOBUFS;
1589 goto cleanup;
1590 }
1591
1592 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
1593 rth->rt_flags = flags;
1594 rth->rt_type = res->type;
1595 rth->rt_is_input = 1;
1596 rth->rt_iif = 0;
1597 rth->rt_pmtu = 0;
1598 rth->rt_gateway = 0;
1599 rth->rt_uses_gateway = 0;
1600 INIT_LIST_HEAD(&rth->rt_uncached);
1601
1602 rth->dst.input = ip_forward;
1603 rth->dst.output = ip_output;
1604
1605 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1606 skb_dst_set(skb, &rth->dst);
1607 out:
1608 err = 0;
1609 cleanup:
1610 return err;
1611 }
1612
1613 static int ip_mkroute_input(struct sk_buff *skb,
1614 struct fib_result *res,
1615 const struct flowi4 *fl4,
1616 struct in_device *in_dev,
1617 __be32 daddr, __be32 saddr, u32 tos)
1618 {
1619 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1620 if (res->fi && res->fi->fib_nhs > 1)
1621 fib_select_multipath(res);
1622 #endif
1623
1624 /* create a routing cache entry */
1625 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1626 }
1627
1628 /*
1629 * NOTE. We drop all the packets that has local source
1630 * addresses, because every properly looped back packet
1631 * must have correct destination already attached by output routine.
1632 *
1633 * Such approach solves two big problems:
1634 * 1. Not simplex devices are handled properly.
1635 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1636 * called with rcu_read_lock()
1637 */
1638
1639 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1640 u8 tos, struct net_device *dev)
1641 {
1642 struct fib_result res;
1643 struct in_device *in_dev = __in_dev_get_rcu(dev);
1644 struct flowi4 fl4;
1645 unsigned int flags = 0;
1646 u32 itag = 0;
1647 struct rtable *rth;
1648 int err = -EINVAL;
1649 struct net *net = dev_net(dev);
1650 bool do_cache;
1651
1652 /* IP on this device is disabled. */
1653
1654 if (!in_dev)
1655 goto out;
1656
1657 /* Check for the most weird martians, which can be not detected
1658 by fib_lookup.
1659 */
1660
1661 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1662 goto martian_source;
1663
1664 res.fi = NULL;
1665 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1666 goto brd_input;
1667
1668 /* Accept zero addresses only to limited broadcast;
1669 * I even do not know to fix it or not. Waiting for complains :-)
1670 */
1671 if (ipv4_is_zeronet(saddr))
1672 goto martian_source;
1673
1674 if (ipv4_is_zeronet(daddr))
1675 goto martian_destination;
1676
1677 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1678 * and call it once if daddr or/and saddr are loopback addresses
1679 */
1680 if (ipv4_is_loopback(daddr)) {
1681 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1682 goto martian_destination;
1683 } else if (ipv4_is_loopback(saddr)) {
1684 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1685 goto martian_source;
1686 }
1687
1688 /*
1689 * Now we are ready to route packet.
1690 */
1691 fl4.flowi4_oif = 0;
1692 fl4.flowi4_iif = dev->ifindex;
1693 fl4.flowi4_mark = skb->mark;
1694 fl4.flowi4_tos = tos;
1695 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1696 fl4.daddr = daddr;
1697 fl4.saddr = saddr;
1698 err = fib_lookup(net, &fl4, &res);
1699 if (err != 0)
1700 goto no_route;
1701
1702 RT_CACHE_STAT_INC(in_slow_tot);
1703
1704 if (res.type == RTN_BROADCAST)
1705 goto brd_input;
1706
1707 if (res.type == RTN_LOCAL) {
1708 err = fib_validate_source(skb, saddr, daddr, tos,
1709 LOOPBACK_IFINDEX,
1710 dev, in_dev, &itag);
1711 if (err < 0)
1712 goto martian_source_keep_err;
1713 goto local_input;
1714 }
1715
1716 if (!IN_DEV_FORWARD(in_dev))
1717 goto no_route;
1718 if (res.type != RTN_UNICAST)
1719 goto martian_destination;
1720
1721 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1722 out: return err;
1723
1724 brd_input:
1725 if (skb->protocol != htons(ETH_P_IP))
1726 goto e_inval;
1727
1728 if (!ipv4_is_zeronet(saddr)) {
1729 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1730 in_dev, &itag);
1731 if (err < 0)
1732 goto martian_source_keep_err;
1733 }
1734 flags |= RTCF_BROADCAST;
1735 res.type = RTN_BROADCAST;
1736 RT_CACHE_STAT_INC(in_brd);
1737
1738 local_input:
1739 do_cache = false;
1740 if (res.fi) {
1741 if (!itag) {
1742 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1743 if (rt_cache_valid(rth)) {
1744 skb_dst_set_noref(skb, &rth->dst);
1745 err = 0;
1746 goto out;
1747 }
1748 do_cache = true;
1749 }
1750 }
1751
1752 rth = rt_dst_alloc(net->loopback_dev,
1753 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1754 if (!rth)
1755 goto e_nobufs;
1756
1757 rth->dst.input= ip_local_deliver;
1758 rth->dst.output= ip_rt_bug;
1759 #ifdef CONFIG_IP_ROUTE_CLASSID
1760 rth->dst.tclassid = itag;
1761 #endif
1762
1763 rth->rt_genid = rt_genid(net);
1764 rth->rt_flags = flags|RTCF_LOCAL;
1765 rth->rt_type = res.type;
1766 rth->rt_is_input = 1;
1767 rth->rt_iif = 0;
1768 rth->rt_pmtu = 0;
1769 rth->rt_gateway = 0;
1770 rth->rt_uses_gateway = 0;
1771 INIT_LIST_HEAD(&rth->rt_uncached);
1772 if (res.type == RTN_UNREACHABLE) {
1773 rth->dst.input= ip_error;
1774 rth->dst.error= -err;
1775 rth->rt_flags &= ~RTCF_LOCAL;
1776 }
1777 if (do_cache)
1778 rt_cache_route(&FIB_RES_NH(res), rth);
1779 skb_dst_set(skb, &rth->dst);
1780 err = 0;
1781 goto out;
1782
1783 no_route:
1784 RT_CACHE_STAT_INC(in_no_route);
1785 res.type = RTN_UNREACHABLE;
1786 if (err == -ESRCH)
1787 err = -ENETUNREACH;
1788 goto local_input;
1789
1790 /*
1791 * Do not cache martian addresses: they should be logged (RFC1812)
1792 */
1793 martian_destination:
1794 RT_CACHE_STAT_INC(in_martian_dst);
1795 #ifdef CONFIG_IP_ROUTE_VERBOSE
1796 if (IN_DEV_LOG_MARTIANS(in_dev))
1797 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1798 &daddr, &saddr, dev->name);
1799 #endif
1800
1801 e_inval:
1802 err = -EINVAL;
1803 goto out;
1804
1805 e_nobufs:
1806 err = -ENOBUFS;
1807 goto out;
1808
1809 martian_source:
1810 err = -EINVAL;
1811 martian_source_keep_err:
1812 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1813 goto out;
1814 }
1815
1816 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1817 u8 tos, struct net_device *dev)
1818 {
1819 int res;
1820
1821 rcu_read_lock();
1822
1823 /* Multicast recognition logic is moved from route cache to here.
1824 The problem was that too many Ethernet cards have broken/missing
1825 hardware multicast filters :-( As result the host on multicasting
1826 network acquires a lot of useless route cache entries, sort of
1827 SDR messages from all the world. Now we try to get rid of them.
1828 Really, provided software IP multicast filter is organized
1829 reasonably (at least, hashed), it does not result in a slowdown
1830 comparing with route cache reject entries.
1831 Note, that multicast routers are not affected, because
1832 route cache entry is created eventually.
1833 */
1834 if (ipv4_is_multicast(daddr)) {
1835 struct in_device *in_dev = __in_dev_get_rcu(dev);
1836
1837 if (in_dev) {
1838 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1839 ip_hdr(skb)->protocol);
1840 if (our
1841 #ifdef CONFIG_IP_MROUTE
1842 ||
1843 (!ipv4_is_local_multicast(daddr) &&
1844 IN_DEV_MFORWARD(in_dev))
1845 #endif
1846 ) {
1847 int res = ip_route_input_mc(skb, daddr, saddr,
1848 tos, dev, our);
1849 rcu_read_unlock();
1850 return res;
1851 }
1852 }
1853 rcu_read_unlock();
1854 return -EINVAL;
1855 }
1856 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1857 rcu_read_unlock();
1858 return res;
1859 }
1860 EXPORT_SYMBOL(ip_route_input_noref);
1861
1862 /* called with rcu_read_lock() */
1863 static struct rtable *__mkroute_output(const struct fib_result *res,
1864 const struct flowi4 *fl4, int orig_oif,
1865 struct net_device *dev_out,
1866 unsigned int flags)
1867 {
1868 struct fib_info *fi = res->fi;
1869 struct fib_nh_exception *fnhe;
1870 struct in_device *in_dev;
1871 u16 type = res->type;
1872 struct rtable *rth;
1873 bool do_cache;
1874
1875 in_dev = __in_dev_get_rcu(dev_out);
1876 if (!in_dev)
1877 return ERR_PTR(-EINVAL);
1878
1879 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1880 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1881 return ERR_PTR(-EINVAL);
1882
1883 if (ipv4_is_lbcast(fl4->daddr))
1884 type = RTN_BROADCAST;
1885 else if (ipv4_is_multicast(fl4->daddr))
1886 type = RTN_MULTICAST;
1887 else if (ipv4_is_zeronet(fl4->daddr))
1888 return ERR_PTR(-EINVAL);
1889
1890 if (dev_out->flags & IFF_LOOPBACK)
1891 flags |= RTCF_LOCAL;
1892
1893 do_cache = true;
1894 if (type == RTN_BROADCAST) {
1895 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1896 fi = NULL;
1897 } else if (type == RTN_MULTICAST) {
1898 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1899 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1900 fl4->flowi4_proto))
1901 flags &= ~RTCF_LOCAL;
1902 else
1903 do_cache = false;
1904 /* If multicast route do not exist use
1905 * default one, but do not gateway in this case.
1906 * Yes, it is hack.
1907 */
1908 if (fi && res->prefixlen < 4)
1909 fi = NULL;
1910 }
1911
1912 fnhe = NULL;
1913 do_cache &= fi != NULL;
1914 if (do_cache) {
1915 struct rtable __rcu **prth;
1916 struct fib_nh *nh = &FIB_RES_NH(*res);
1917
1918 fnhe = find_exception(nh, fl4->daddr);
1919 if (fnhe)
1920 prth = &fnhe->fnhe_rth_output;
1921 else {
1922 if (unlikely(fl4->flowi4_flags &
1923 FLOWI_FLAG_KNOWN_NH &&
1924 !(nh->nh_gw &&
1925 nh->nh_scope == RT_SCOPE_LINK))) {
1926 do_cache = false;
1927 goto add;
1928 }
1929 prth = __this_cpu_ptr(nh->nh_pcpu_rth_output);
1930 }
1931 rth = rcu_dereference(*prth);
1932 if (rt_cache_valid(rth)) {
1933 dst_hold(&rth->dst);
1934 return rth;
1935 }
1936 }
1937
1938 add:
1939 rth = rt_dst_alloc(dev_out,
1940 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1941 IN_DEV_CONF_GET(in_dev, NOXFRM),
1942 do_cache);
1943 if (!rth)
1944 return ERR_PTR(-ENOBUFS);
1945
1946 rth->dst.output = ip_output;
1947
1948 rth->rt_genid = rt_genid(dev_net(dev_out));
1949 rth->rt_flags = flags;
1950 rth->rt_type = type;
1951 rth->rt_is_input = 0;
1952 rth->rt_iif = orig_oif ? : 0;
1953 rth->rt_pmtu = 0;
1954 rth->rt_gateway = 0;
1955 rth->rt_uses_gateway = 0;
1956 INIT_LIST_HEAD(&rth->rt_uncached);
1957
1958 RT_CACHE_STAT_INC(out_slow_tot);
1959
1960 if (flags & RTCF_LOCAL)
1961 rth->dst.input = ip_local_deliver;
1962 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1963 if (flags & RTCF_LOCAL &&
1964 !(dev_out->flags & IFF_LOOPBACK)) {
1965 rth->dst.output = ip_mc_output;
1966 RT_CACHE_STAT_INC(out_slow_mc);
1967 }
1968 #ifdef CONFIG_IP_MROUTE
1969 if (type == RTN_MULTICAST) {
1970 if (IN_DEV_MFORWARD(in_dev) &&
1971 !ipv4_is_local_multicast(fl4->daddr)) {
1972 rth->dst.input = ip_mr_input;
1973 rth->dst.output = ip_mc_output;
1974 }
1975 }
1976 #endif
1977 }
1978
1979 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1980
1981 return rth;
1982 }
1983
1984 /*
1985 * Major route resolver routine.
1986 */
1987
1988 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1989 {
1990 struct net_device *dev_out = NULL;
1991 __u8 tos = RT_FL_TOS(fl4);
1992 unsigned int flags = 0;
1993 struct fib_result res;
1994 struct rtable *rth;
1995 int orig_oif;
1996
1997 res.tclassid = 0;
1998 res.fi = NULL;
1999 res.table = NULL;
2000
2001 orig_oif = fl4->flowi4_oif;
2002
2003 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2004 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2005 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2006 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2007
2008 rcu_read_lock();
2009 if (fl4->saddr) {
2010 rth = ERR_PTR(-EINVAL);
2011 if (ipv4_is_multicast(fl4->saddr) ||
2012 ipv4_is_lbcast(fl4->saddr) ||
2013 ipv4_is_zeronet(fl4->saddr))
2014 goto out;
2015
2016 /* I removed check for oif == dev_out->oif here.
2017 It was wrong for two reasons:
2018 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2019 is assigned to multiple interfaces.
2020 2. Moreover, we are allowed to send packets with saddr
2021 of another iface. --ANK
2022 */
2023
2024 if (fl4->flowi4_oif == 0 &&
2025 (ipv4_is_multicast(fl4->daddr) ||
2026 ipv4_is_lbcast(fl4->daddr))) {
2027 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2028 dev_out = __ip_dev_find(net, fl4->saddr, false);
2029 if (dev_out == NULL)
2030 goto out;
2031
2032 /* Special hack: user can direct multicasts
2033 and limited broadcast via necessary interface
2034 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2035 This hack is not just for fun, it allows
2036 vic,vat and friends to work.
2037 They bind socket to loopback, set ttl to zero
2038 and expect that it will work.
2039 From the viewpoint of routing cache they are broken,
2040 because we are not allowed to build multicast path
2041 with loopback source addr (look, routing cache
2042 cannot know, that ttl is zero, so that packet
2043 will not leave this host and route is valid).
2044 Luckily, this hack is good workaround.
2045 */
2046
2047 fl4->flowi4_oif = dev_out->ifindex;
2048 goto make_route;
2049 }
2050
2051 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2052 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2053 if (!__ip_dev_find(net, fl4->saddr, false))
2054 goto out;
2055 }
2056 }
2057
2058
2059 if (fl4->flowi4_oif) {
2060 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2061 rth = ERR_PTR(-ENODEV);
2062 if (dev_out == NULL)
2063 goto out;
2064
2065 /* RACE: Check return value of inet_select_addr instead. */
2066 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2067 rth = ERR_PTR(-ENETUNREACH);
2068 goto out;
2069 }
2070 if (ipv4_is_local_multicast(fl4->daddr) ||
2071 ipv4_is_lbcast(fl4->daddr)) {
2072 if (!fl4->saddr)
2073 fl4->saddr = inet_select_addr(dev_out, 0,
2074 RT_SCOPE_LINK);
2075 goto make_route;
2076 }
2077 if (fl4->saddr) {
2078 if (ipv4_is_multicast(fl4->daddr))
2079 fl4->saddr = inet_select_addr(dev_out, 0,
2080 fl4->flowi4_scope);
2081 else if (!fl4->daddr)
2082 fl4->saddr = inet_select_addr(dev_out, 0,
2083 RT_SCOPE_HOST);
2084 }
2085 }
2086
2087 if (!fl4->daddr) {
2088 fl4->daddr = fl4->saddr;
2089 if (!fl4->daddr)
2090 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2091 dev_out = net->loopback_dev;
2092 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2093 res.type = RTN_LOCAL;
2094 flags |= RTCF_LOCAL;
2095 goto make_route;
2096 }
2097
2098 if (fib_lookup(net, fl4, &res)) {
2099 res.fi = NULL;
2100 res.table = NULL;
2101 if (fl4->flowi4_oif) {
2102 /* Apparently, routing tables are wrong. Assume,
2103 that the destination is on link.
2104
2105 WHY? DW.
2106 Because we are allowed to send to iface
2107 even if it has NO routes and NO assigned
2108 addresses. When oif is specified, routing
2109 tables are looked up with only one purpose:
2110 to catch if destination is gatewayed, rather than
2111 direct. Moreover, if MSG_DONTROUTE is set,
2112 we send packet, ignoring both routing tables
2113 and ifaddr state. --ANK
2114
2115
2116 We could make it even if oif is unknown,
2117 likely IPv6, but we do not.
2118 */
2119
2120 if (fl4->saddr == 0)
2121 fl4->saddr = inet_select_addr(dev_out, 0,
2122 RT_SCOPE_LINK);
2123 res.type = RTN_UNICAST;
2124 goto make_route;
2125 }
2126 rth = ERR_PTR(-ENETUNREACH);
2127 goto out;
2128 }
2129
2130 if (res.type == RTN_LOCAL) {
2131 if (!fl4->saddr) {
2132 if (res.fi->fib_prefsrc)
2133 fl4->saddr = res.fi->fib_prefsrc;
2134 else
2135 fl4->saddr = fl4->daddr;
2136 }
2137 dev_out = net->loopback_dev;
2138 fl4->flowi4_oif = dev_out->ifindex;
2139 flags |= RTCF_LOCAL;
2140 goto make_route;
2141 }
2142
2143 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2144 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2145 fib_select_multipath(&res);
2146 else
2147 #endif
2148 if (!res.prefixlen &&
2149 res.table->tb_num_default > 1 &&
2150 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2151 fib_select_default(&res);
2152
2153 if (!fl4->saddr)
2154 fl4->saddr = FIB_RES_PREFSRC(net, res);
2155
2156 dev_out = FIB_RES_DEV(res);
2157 fl4->flowi4_oif = dev_out->ifindex;
2158
2159
2160 make_route:
2161 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2162
2163 out:
2164 rcu_read_unlock();
2165 return rth;
2166 }
2167 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2168
2169 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2170 {
2171 return NULL;
2172 }
2173
2174 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2175 {
2176 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2177
2178 return mtu ? : dst->dev->mtu;
2179 }
2180
2181 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2182 struct sk_buff *skb, u32 mtu)
2183 {
2184 }
2185
2186 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2187 struct sk_buff *skb)
2188 {
2189 }
2190
2191 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2192 unsigned long old)
2193 {
2194 return NULL;
2195 }
2196
2197 static struct dst_ops ipv4_dst_blackhole_ops = {
2198 .family = AF_INET,
2199 .protocol = cpu_to_be16(ETH_P_IP),
2200 .check = ipv4_blackhole_dst_check,
2201 .mtu = ipv4_blackhole_mtu,
2202 .default_advmss = ipv4_default_advmss,
2203 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2204 .redirect = ipv4_rt_blackhole_redirect,
2205 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2206 .neigh_lookup = ipv4_neigh_lookup,
2207 };
2208
2209 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2210 {
2211 struct rtable *ort = (struct rtable *) dst_orig;
2212 struct rtable *rt;
2213
2214 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2215 if (rt) {
2216 struct dst_entry *new = &rt->dst;
2217
2218 new->__use = 1;
2219 new->input = dst_discard;
2220 new->output = dst_discard;
2221
2222 new->dev = ort->dst.dev;
2223 if (new->dev)
2224 dev_hold(new->dev);
2225
2226 rt->rt_is_input = ort->rt_is_input;
2227 rt->rt_iif = ort->rt_iif;
2228 rt->rt_pmtu = ort->rt_pmtu;
2229
2230 rt->rt_genid = rt_genid(net);
2231 rt->rt_flags = ort->rt_flags;
2232 rt->rt_type = ort->rt_type;
2233 rt->rt_gateway = ort->rt_gateway;
2234 rt->rt_uses_gateway = ort->rt_uses_gateway;
2235
2236 INIT_LIST_HEAD(&rt->rt_uncached);
2237
2238 dst_free(new);
2239 }
2240
2241 dst_release(dst_orig);
2242
2243 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2244 }
2245
2246 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2247 struct sock *sk)
2248 {
2249 struct rtable *rt = __ip_route_output_key(net, flp4);
2250
2251 if (IS_ERR(rt))
2252 return rt;
2253
2254 if (flp4->flowi4_proto)
2255 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2256 flowi4_to_flowi(flp4),
2257 sk, 0);
2258
2259 return rt;
2260 }
2261 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2262
2263 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2264 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2265 u32 seq, int event, int nowait, unsigned int flags)
2266 {
2267 struct rtable *rt = skb_rtable(skb);
2268 struct rtmsg *r;
2269 struct nlmsghdr *nlh;
2270 unsigned long expires = 0;
2271 u32 error;
2272 u32 metrics[RTAX_MAX];
2273
2274 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2275 if (nlh == NULL)
2276 return -EMSGSIZE;
2277
2278 r = nlmsg_data(nlh);
2279 r->rtm_family = AF_INET;
2280 r->rtm_dst_len = 32;
2281 r->rtm_src_len = 0;
2282 r->rtm_tos = fl4->flowi4_tos;
2283 r->rtm_table = RT_TABLE_MAIN;
2284 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2285 goto nla_put_failure;
2286 r->rtm_type = rt->rt_type;
2287 r->rtm_scope = RT_SCOPE_UNIVERSE;
2288 r->rtm_protocol = RTPROT_UNSPEC;
2289 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2290 if (rt->rt_flags & RTCF_NOTIFY)
2291 r->rtm_flags |= RTM_F_NOTIFY;
2292
2293 if (nla_put_be32(skb, RTA_DST, dst))
2294 goto nla_put_failure;
2295 if (src) {
2296 r->rtm_src_len = 32;
2297 if (nla_put_be32(skb, RTA_SRC, src))
2298 goto nla_put_failure;
2299 }
2300 if (rt->dst.dev &&
2301 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2302 goto nla_put_failure;
2303 #ifdef CONFIG_IP_ROUTE_CLASSID
2304 if (rt->dst.tclassid &&
2305 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2306 goto nla_put_failure;
2307 #endif
2308 if (!rt_is_input_route(rt) &&
2309 fl4->saddr != src) {
2310 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2311 goto nla_put_failure;
2312 }
2313 if (rt->rt_uses_gateway &&
2314 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2315 goto nla_put_failure;
2316
2317 expires = rt->dst.expires;
2318 if (expires) {
2319 unsigned long now = jiffies;
2320
2321 if (time_before(now, expires))
2322 expires -= now;
2323 else
2324 expires = 0;
2325 }
2326
2327 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2328 if (rt->rt_pmtu && expires)
2329 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2330 if (rtnetlink_put_metrics(skb, metrics) < 0)
2331 goto nla_put_failure;
2332
2333 if (fl4->flowi4_mark &&
2334 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2335 goto nla_put_failure;
2336
2337 error = rt->dst.error;
2338
2339 if (rt_is_input_route(rt)) {
2340 #ifdef CONFIG_IP_MROUTE
2341 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2342 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2343 int err = ipmr_get_route(net, skb,
2344 fl4->saddr, fl4->daddr,
2345 r, nowait);
2346 if (err <= 0) {
2347 if (!nowait) {
2348 if (err == 0)
2349 return 0;
2350 goto nla_put_failure;
2351 } else {
2352 if (err == -EMSGSIZE)
2353 goto nla_put_failure;
2354 error = err;
2355 }
2356 }
2357 } else
2358 #endif
2359 if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
2360 goto nla_put_failure;
2361 }
2362
2363 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2364 goto nla_put_failure;
2365
2366 return nlmsg_end(skb, nlh);
2367
2368 nla_put_failure:
2369 nlmsg_cancel(skb, nlh);
2370 return -EMSGSIZE;
2371 }
2372
2373 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2374 {
2375 struct net *net = sock_net(in_skb->sk);
2376 struct rtmsg *rtm;
2377 struct nlattr *tb[RTA_MAX+1];
2378 struct rtable *rt = NULL;
2379 struct flowi4 fl4;
2380 __be32 dst = 0;
2381 __be32 src = 0;
2382 u32 iif;
2383 int err;
2384 int mark;
2385 struct sk_buff *skb;
2386
2387 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2388 if (err < 0)
2389 goto errout;
2390
2391 rtm = nlmsg_data(nlh);
2392
2393 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2394 if (skb == NULL) {
2395 err = -ENOBUFS;
2396 goto errout;
2397 }
2398
2399 /* Reserve room for dummy headers, this skb can pass
2400 through good chunk of routing engine.
2401 */
2402 skb_reset_mac_header(skb);
2403 skb_reset_network_header(skb);
2404
2405 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2406 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2407 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2408
2409 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2410 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2411 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2412 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2413
2414 memset(&fl4, 0, sizeof(fl4));
2415 fl4.daddr = dst;
2416 fl4.saddr = src;
2417 fl4.flowi4_tos = rtm->rtm_tos;
2418 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2419 fl4.flowi4_mark = mark;
2420
2421 if (iif) {
2422 struct net_device *dev;
2423
2424 dev = __dev_get_by_index(net, iif);
2425 if (dev == NULL) {
2426 err = -ENODEV;
2427 goto errout_free;
2428 }
2429
2430 skb->protocol = htons(ETH_P_IP);
2431 skb->dev = dev;
2432 skb->mark = mark;
2433 local_bh_disable();
2434 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2435 local_bh_enable();
2436
2437 rt = skb_rtable(skb);
2438 if (err == 0 && rt->dst.error)
2439 err = -rt->dst.error;
2440 } else {
2441 rt = ip_route_output_key(net, &fl4);
2442
2443 err = 0;
2444 if (IS_ERR(rt))
2445 err = PTR_ERR(rt);
2446 }
2447
2448 if (err)
2449 goto errout_free;
2450
2451 skb_dst_set(skb, &rt->dst);
2452 if (rtm->rtm_flags & RTM_F_NOTIFY)
2453 rt->rt_flags |= RTCF_NOTIFY;
2454
2455 err = rt_fill_info(net, dst, src, &fl4, skb,
2456 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2457 RTM_NEWROUTE, 0, 0);
2458 if (err <= 0)
2459 goto errout_free;
2460
2461 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2462 errout:
2463 return err;
2464
2465 errout_free:
2466 kfree_skb(skb);
2467 goto errout;
2468 }
2469
2470 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2471 {
2472 return skb->len;
2473 }
2474
2475 void ip_rt_multicast_event(struct in_device *in_dev)
2476 {
2477 rt_cache_flush(dev_net(in_dev->dev));
2478 }
2479
2480 #ifdef CONFIG_SYSCTL
2481 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2482 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2483 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2484 static int ip_rt_gc_elasticity __read_mostly = 8;
2485
2486 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2487 void __user *buffer,
2488 size_t *lenp, loff_t *ppos)
2489 {
2490 struct net *net = (struct net *)__ctl->extra1;
2491
2492 if (write) {
2493 rt_cache_flush(net);
2494 fnhe_genid_bump(net);
2495 return 0;
2496 }
2497
2498 return -EINVAL;
2499 }
2500
2501 static struct ctl_table ipv4_route_table[] = {
2502 {
2503 .procname = "gc_thresh",
2504 .data = &ipv4_dst_ops.gc_thresh,
2505 .maxlen = sizeof(int),
2506 .mode = 0644,
2507 .proc_handler = proc_dointvec,
2508 },
2509 {
2510 .procname = "max_size",
2511 .data = &ip_rt_max_size,
2512 .maxlen = sizeof(int),
2513 .mode = 0644,
2514 .proc_handler = proc_dointvec,
2515 },
2516 {
2517 /* Deprecated. Use gc_min_interval_ms */
2518
2519 .procname = "gc_min_interval",
2520 .data = &ip_rt_gc_min_interval,
2521 .maxlen = sizeof(int),
2522 .mode = 0644,
2523 .proc_handler = proc_dointvec_jiffies,
2524 },
2525 {
2526 .procname = "gc_min_interval_ms",
2527 .data = &ip_rt_gc_min_interval,
2528 .maxlen = sizeof(int),
2529 .mode = 0644,
2530 .proc_handler = proc_dointvec_ms_jiffies,
2531 },
2532 {
2533 .procname = "gc_timeout",
2534 .data = &ip_rt_gc_timeout,
2535 .maxlen = sizeof(int),
2536 .mode = 0644,
2537 .proc_handler = proc_dointvec_jiffies,
2538 },
2539 {
2540 .procname = "gc_interval",
2541 .data = &ip_rt_gc_interval,
2542 .maxlen = sizeof(int),
2543 .mode = 0644,
2544 .proc_handler = proc_dointvec_jiffies,
2545 },
2546 {
2547 .procname = "redirect_load",
2548 .data = &ip_rt_redirect_load,
2549 .maxlen = sizeof(int),
2550 .mode = 0644,
2551 .proc_handler = proc_dointvec,
2552 },
2553 {
2554 .procname = "redirect_number",
2555 .data = &ip_rt_redirect_number,
2556 .maxlen = sizeof(int),
2557 .mode = 0644,
2558 .proc_handler = proc_dointvec,
2559 },
2560 {
2561 .procname = "redirect_silence",
2562 .data = &ip_rt_redirect_silence,
2563 .maxlen = sizeof(int),
2564 .mode = 0644,
2565 .proc_handler = proc_dointvec,
2566 },
2567 {
2568 .procname = "error_cost",
2569 .data = &ip_rt_error_cost,
2570 .maxlen = sizeof(int),
2571 .mode = 0644,
2572 .proc_handler = proc_dointvec,
2573 },
2574 {
2575 .procname = "error_burst",
2576 .data = &ip_rt_error_burst,
2577 .maxlen = sizeof(int),
2578 .mode = 0644,
2579 .proc_handler = proc_dointvec,
2580 },
2581 {
2582 .procname = "gc_elasticity",
2583 .data = &ip_rt_gc_elasticity,
2584 .maxlen = sizeof(int),
2585 .mode = 0644,
2586 .proc_handler = proc_dointvec,
2587 },
2588 {
2589 .procname = "mtu_expires",
2590 .data = &ip_rt_mtu_expires,
2591 .maxlen = sizeof(int),
2592 .mode = 0644,
2593 .proc_handler = proc_dointvec_jiffies,
2594 },
2595 {
2596 .procname = "min_pmtu",
2597 .data = &ip_rt_min_pmtu,
2598 .maxlen = sizeof(int),
2599 .mode = 0644,
2600 .proc_handler = proc_dointvec,
2601 },
2602 {
2603 .procname = "min_adv_mss",
2604 .data = &ip_rt_min_advmss,
2605 .maxlen = sizeof(int),
2606 .mode = 0644,
2607 .proc_handler = proc_dointvec,
2608 },
2609 { }
2610 };
2611
2612 static struct ctl_table ipv4_route_flush_table[] = {
2613 {
2614 .procname = "flush",
2615 .maxlen = sizeof(int),
2616 .mode = 0200,
2617 .proc_handler = ipv4_sysctl_rtcache_flush,
2618 },
2619 { },
2620 };
2621
2622 static __net_init int sysctl_route_net_init(struct net *net)
2623 {
2624 struct ctl_table *tbl;
2625
2626 tbl = ipv4_route_flush_table;
2627 if (!net_eq(net, &init_net)) {
2628 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2629 if (tbl == NULL)
2630 goto err_dup;
2631
2632 /* Don't export sysctls to unprivileged users */
2633 if (net->user_ns != &init_user_ns)
2634 tbl[0].procname = NULL;
2635 }
2636 tbl[0].extra1 = net;
2637
2638 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2639 if (net->ipv4.route_hdr == NULL)
2640 goto err_reg;
2641 return 0;
2642
2643 err_reg:
2644 if (tbl != ipv4_route_flush_table)
2645 kfree(tbl);
2646 err_dup:
2647 return -ENOMEM;
2648 }
2649
2650 static __net_exit void sysctl_route_net_exit(struct net *net)
2651 {
2652 struct ctl_table *tbl;
2653
2654 tbl = net->ipv4.route_hdr->ctl_table_arg;
2655 unregister_net_sysctl_table(net->ipv4.route_hdr);
2656 BUG_ON(tbl == ipv4_route_flush_table);
2657 kfree(tbl);
2658 }
2659
2660 static __net_initdata struct pernet_operations sysctl_route_ops = {
2661 .init = sysctl_route_net_init,
2662 .exit = sysctl_route_net_exit,
2663 };
2664 #endif
2665
2666 static __net_init int rt_genid_init(struct net *net)
2667 {
2668 atomic_set(&net->rt_genid, 0);
2669 atomic_set(&net->fnhe_genid, 0);
2670 get_random_bytes(&net->ipv4.dev_addr_genid,
2671 sizeof(net->ipv4.dev_addr_genid));
2672 return 0;
2673 }
2674
2675 static __net_initdata struct pernet_operations rt_genid_ops = {
2676 .init = rt_genid_init,
2677 };
2678
2679 static int __net_init ipv4_inetpeer_init(struct net *net)
2680 {
2681 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2682
2683 if (!bp)
2684 return -ENOMEM;
2685 inet_peer_base_init(bp);
2686 net->ipv4.peers = bp;
2687 return 0;
2688 }
2689
2690 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2691 {
2692 struct inet_peer_base *bp = net->ipv4.peers;
2693
2694 net->ipv4.peers = NULL;
2695 inetpeer_invalidate_tree(bp);
2696 kfree(bp);
2697 }
2698
2699 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2700 .init = ipv4_inetpeer_init,
2701 .exit = ipv4_inetpeer_exit,
2702 };
2703
2704 #ifdef CONFIG_IP_ROUTE_CLASSID
2705 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2706 #endif /* CONFIG_IP_ROUTE_CLASSID */
2707
2708 int __init ip_rt_init(void)
2709 {
2710 int rc = 0;
2711
2712 #ifdef CONFIG_IP_ROUTE_CLASSID
2713 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2714 if (!ip_rt_acct)
2715 panic("IP: failed to allocate ip_rt_acct\n");
2716 #endif
2717
2718 ipv4_dst_ops.kmem_cachep =
2719 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2720 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2721
2722 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2723
2724 if (dst_entries_init(&ipv4_dst_ops) < 0)
2725 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2726
2727 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2728 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2729
2730 ipv4_dst_ops.gc_thresh = ~0;
2731 ip_rt_max_size = INT_MAX;
2732
2733 devinet_init();
2734 ip_fib_init();
2735
2736 if (ip_rt_proc_init())
2737 pr_err("Unable to create route proc files\n");
2738 #ifdef CONFIG_XFRM
2739 xfrm_init();
2740 xfrm4_init();
2741 #endif
2742 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2743
2744 #ifdef CONFIG_SYSCTL
2745 register_pernet_subsys(&sysctl_route_ops);
2746 #endif
2747 register_pernet_subsys(&rt_genid_ops);
2748 register_pernet_subsys(&ipv4_inetpeer_ops);
2749 return rc;
2750 }
2751
2752 #ifdef CONFIG_SYSCTL
2753 /*
2754 * We really need to sanitize the damn ipv4 init order, then all
2755 * this nonsense will go away.
2756 */
2757 void __init ip_static_sysctl_init(void)
2758 {
2759 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2760 }
2761 #endif
Linus' kernel tree