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MAINTAINERS: EDAC: add Mauro and Borislav as interim patch collectors
[linux-2.6/btrfs-unstable.git] / net / ipv4 / route.c
blob4c011ec69ed43efacdf692592a849d691ca93d2d
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 RT_GC_TIMEOUT (300*HZ)
116
117 static int ip_rt_max_size;
118 static int ip_rt_redirect_number __read_mostly = 9;
119 static int ip_rt_redirect_load __read_mostly = HZ / 50;
120 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
121 static int ip_rt_error_cost __read_mostly = HZ;
122 static int ip_rt_error_burst __read_mostly = 5 * HZ;
123 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
124 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
125 static int ip_rt_min_advmss __read_mostly = 256;
126
127 /*
128 * Interface to generic destination cache.
129 */
130
131 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
132 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
133 static unsigned int ipv4_mtu(const struct dst_entry *dst);
134 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
135 static void ipv4_link_failure(struct sk_buff *skb);
136 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
137 struct sk_buff *skb, u32 mtu);
138 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
139 struct sk_buff *skb);
140 static void ipv4_dst_destroy(struct dst_entry *dst);
141
142 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
143 int how)
144 {
145 }
146
147 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
148 {
149 WARN_ON(1);
150 return NULL;
151 }
152
153 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
154 struct sk_buff *skb,
155 const void *daddr);
156
157 static struct dst_ops ipv4_dst_ops = {
158 .family = AF_INET,
159 .protocol = cpu_to_be16(ETH_P_IP),
160 .check = ipv4_dst_check,
161 .default_advmss = ipv4_default_advmss,
162 .mtu = ipv4_mtu,
163 .cow_metrics = ipv4_cow_metrics,
164 .destroy = ipv4_dst_destroy,
165 .ifdown = ipv4_dst_ifdown,
166 .negative_advice = ipv4_negative_advice,
167 .link_failure = ipv4_link_failure,
168 .update_pmtu = ip_rt_update_pmtu,
169 .redirect = ip_do_redirect,
170 .local_out = __ip_local_out,
171 .neigh_lookup = ipv4_neigh_lookup,
172 };
173
174 #define ECN_OR_COST(class) TC_PRIO_##class
175
176 const __u8 ip_tos2prio[16] = {
177 TC_PRIO_BESTEFFORT,
178 ECN_OR_COST(BESTEFFORT),
179 TC_PRIO_BESTEFFORT,
180 ECN_OR_COST(BESTEFFORT),
181 TC_PRIO_BULK,
182 ECN_OR_COST(BULK),
183 TC_PRIO_BULK,
184 ECN_OR_COST(BULK),
185 TC_PRIO_INTERACTIVE,
186 ECN_OR_COST(INTERACTIVE),
187 TC_PRIO_INTERACTIVE,
188 ECN_OR_COST(INTERACTIVE),
189 TC_PRIO_INTERACTIVE_BULK,
190 ECN_OR_COST(INTERACTIVE_BULK),
191 TC_PRIO_INTERACTIVE_BULK,
192 ECN_OR_COST(INTERACTIVE_BULK)
193 };
194 EXPORT_SYMBOL(ip_tos2prio);
195
196 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
197 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
198
199 #ifdef CONFIG_PROC_FS
200 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
201 {
202 if (*pos)
203 return NULL;
204 return SEQ_START_TOKEN;
205 }
206
207 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
208 {
209 ++*pos;
210 return NULL;
211 }
212
213 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
214 {
215 }
216
217 static int rt_cache_seq_show(struct seq_file *seq, void *v)
218 {
219 if (v == SEQ_START_TOKEN)
220 seq_printf(seq, "%-127s\n",
221 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
222 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
223 "HHUptod\tSpecDst");
224 return 0;
225 }
226
227 static const struct seq_operations rt_cache_seq_ops = {
228 .start = rt_cache_seq_start,
229 .next = rt_cache_seq_next,
230 .stop = rt_cache_seq_stop,
231 .show = rt_cache_seq_show,
232 };
233
234 static int rt_cache_seq_open(struct inode *inode, struct file *file)
235 {
236 return seq_open(file, &rt_cache_seq_ops);
237 }
238
239 static const struct file_operations rt_cache_seq_fops = {
240 .owner = THIS_MODULE,
241 .open = rt_cache_seq_open,
242 .read = seq_read,
243 .llseek = seq_lseek,
244 .release = seq_release,
245 };
246
247
248 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
249 {
250 int cpu;
251
252 if (*pos == 0)
253 return SEQ_START_TOKEN;
254
255 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
256 if (!cpu_possible(cpu))
257 continue;
258 *pos = cpu+1;
259 return &per_cpu(rt_cache_stat, cpu);
260 }
261 return NULL;
262 }
263
264 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
265 {
266 int cpu;
267
268 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
269 if (!cpu_possible(cpu))
270 continue;
271 *pos = cpu+1;
272 return &per_cpu(rt_cache_stat, cpu);
273 }
274 return NULL;
275
276 }
277
278 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
279 {
280
281 }
282
283 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
284 {
285 struct rt_cache_stat *st = v;
286
287 if (v == SEQ_START_TOKEN) {
288 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");
289 return 0;
290 }
291
292 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
293 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
294 dst_entries_get_slow(&ipv4_dst_ops),
295 0, /* st->in_hit */
296 st->in_slow_tot,
297 st->in_slow_mc,
298 st->in_no_route,
299 st->in_brd,
300 st->in_martian_dst,
301 st->in_martian_src,
302
303 0, /* st->out_hit */
304 st->out_slow_tot,
305 st->out_slow_mc,
306
307 0, /* st->gc_total */
308 0, /* st->gc_ignored */
309 0, /* st->gc_goal_miss */
310 0, /* st->gc_dst_overflow */
311 0, /* st->in_hlist_search */
312 0 /* st->out_hlist_search */
313 );
314 return 0;
315 }
316
317 static const struct seq_operations rt_cpu_seq_ops = {
318 .start = rt_cpu_seq_start,
319 .next = rt_cpu_seq_next,
320 .stop = rt_cpu_seq_stop,
321 .show = rt_cpu_seq_show,
322 };
323
324
325 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
326 {
327 return seq_open(file, &rt_cpu_seq_ops);
328 }
329
330 static const struct file_operations rt_cpu_seq_fops = {
331 .owner = THIS_MODULE,
332 .open = rt_cpu_seq_open,
333 .read = seq_read,
334 .llseek = seq_lseek,
335 .release = seq_release,
336 };
337
338 #ifdef CONFIG_IP_ROUTE_CLASSID
339 static int rt_acct_proc_show(struct seq_file *m, void *v)
340 {
341 struct ip_rt_acct *dst, *src;
342 unsigned int i, j;
343
344 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
345 if (!dst)
346 return -ENOMEM;
347
348 for_each_possible_cpu(i) {
349 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
350 for (j = 0; j < 256; j++) {
351 dst[j].o_bytes += src[j].o_bytes;
352 dst[j].o_packets += src[j].o_packets;
353 dst[j].i_bytes += src[j].i_bytes;
354 dst[j].i_packets += src[j].i_packets;
355 }
356 }
357
358 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
359 kfree(dst);
360 return 0;
361 }
362
363 static int rt_acct_proc_open(struct inode *inode, struct file *file)
364 {
365 return single_open(file, rt_acct_proc_show, NULL);
366 }
367
368 static const struct file_operations rt_acct_proc_fops = {
369 .owner = THIS_MODULE,
370 .open = rt_acct_proc_open,
371 .read = seq_read,
372 .llseek = seq_lseek,
373 .release = single_release,
374 };
375 #endif
376
377 static int __net_init ip_rt_do_proc_init(struct net *net)
378 {
379 struct proc_dir_entry *pde;
380
381 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
382 &rt_cache_seq_fops);
383 if (!pde)
384 goto err1;
385
386 pde = proc_create("rt_cache", S_IRUGO,
387 net->proc_net_stat, &rt_cpu_seq_fops);
388 if (!pde)
389 goto err2;
390
391 #ifdef CONFIG_IP_ROUTE_CLASSID
392 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
393 if (!pde)
394 goto err3;
395 #endif
396 return 0;
397
398 #ifdef CONFIG_IP_ROUTE_CLASSID
399 err3:
400 remove_proc_entry("rt_cache", net->proc_net_stat);
401 #endif
402 err2:
403 remove_proc_entry("rt_cache", net->proc_net);
404 err1:
405 return -ENOMEM;
406 }
407
408 static void __net_exit ip_rt_do_proc_exit(struct net *net)
409 {
410 remove_proc_entry("rt_cache", net->proc_net_stat);
411 remove_proc_entry("rt_cache", net->proc_net);
412 #ifdef CONFIG_IP_ROUTE_CLASSID
413 remove_proc_entry("rt_acct", net->proc_net);
414 #endif
415 }
416
417 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
418 .init = ip_rt_do_proc_init,
419 .exit = ip_rt_do_proc_exit,
420 };
421
422 static int __init ip_rt_proc_init(void)
423 {
424 return register_pernet_subsys(&ip_rt_proc_ops);
425 }
426
427 #else
428 static inline int ip_rt_proc_init(void)
429 {
430 return 0;
431 }
432 #endif /* CONFIG_PROC_FS */
433
434 static inline bool rt_is_expired(const struct rtable *rth)
435 {
436 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
437 }
438
439 void rt_cache_flush(struct net *net)
440 {
441 rt_genid_bump_ipv4(net);
442 }
443
444 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
445 struct sk_buff *skb,
446 const void *daddr)
447 {
448 struct net_device *dev = dst->dev;
449 const __be32 *pkey = daddr;
450 const struct rtable *rt;
451 struct neighbour *n;
452
453 rt = (const struct rtable *) dst;
454 if (rt->rt_gateway)
455 pkey = (const __be32 *) &rt->rt_gateway;
456 else if (skb)
457 pkey = &ip_hdr(skb)->daddr;
458
459 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
460 if (n)
461 return n;
462 return neigh_create(&arp_tbl, pkey, dev);
463 }
464
465 /*
466 * Peer allocation may fail only in serious out-of-memory conditions. However
467 * we still can generate some output.
468 * Random ID selection looks a bit dangerous because we have no chances to
469 * select ID being unique in a reasonable period of time.
470 * But broken packet identifier may be better than no packet at all.
471 */
472 static void ip_select_fb_ident(struct iphdr *iph)
473 {
474 static DEFINE_SPINLOCK(ip_fb_id_lock);
475 static u32 ip_fallback_id;
476 u32 salt;
477
478 spin_lock_bh(&ip_fb_id_lock);
479 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
480 iph->id = htons(salt & 0xFFFF);
481 ip_fallback_id = salt;
482 spin_unlock_bh(&ip_fb_id_lock);
483 }
484
485 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
486 {
487 struct net *net = dev_net(dst->dev);
488 struct inet_peer *peer;
489
490 peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1);
491 if (peer) {
492 iph->id = htons(inet_getid(peer, more));
493 inet_putpeer(peer);
494 return;
495 }
496
497 ip_select_fb_ident(iph);
498 }
499 EXPORT_SYMBOL(__ip_select_ident);
500
501 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
502 const struct iphdr *iph,
503 int oif, u8 tos,
504 u8 prot, u32 mark, int flow_flags)
505 {
506 if (sk) {
507 const struct inet_sock *inet = inet_sk(sk);
508
509 oif = sk->sk_bound_dev_if;
510 mark = sk->sk_mark;
511 tos = RT_CONN_FLAGS(sk);
512 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
513 }
514 flowi4_init_output(fl4, oif, mark, tos,
515 RT_SCOPE_UNIVERSE, prot,
516 flow_flags,
517 iph->daddr, iph->saddr, 0, 0);
518 }
519
520 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
521 const struct sock *sk)
522 {
523 const struct iphdr *iph = ip_hdr(skb);
524 int oif = skb->dev->ifindex;
525 u8 tos = RT_TOS(iph->tos);
526 u8 prot = iph->protocol;
527 u32 mark = skb->mark;
528
529 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
530 }
531
532 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
533 {
534 const struct inet_sock *inet = inet_sk(sk);
535 const struct ip_options_rcu *inet_opt;
536 __be32 daddr = inet->inet_daddr;
537
538 rcu_read_lock();
539 inet_opt = rcu_dereference(inet->inet_opt);
540 if (inet_opt && inet_opt->opt.srr)
541 daddr = inet_opt->opt.faddr;
542 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
543 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
544 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
545 inet_sk_flowi_flags(sk),
546 daddr, inet->inet_saddr, 0, 0);
547 rcu_read_unlock();
548 }
549
550 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
551 const struct sk_buff *skb)
552 {
553 if (skb)
554 build_skb_flow_key(fl4, skb, sk);
555 else
556 build_sk_flow_key(fl4, sk);
557 }
558
559 static inline void rt_free(struct rtable *rt)
560 {
561 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
562 }
563
564 static DEFINE_SPINLOCK(fnhe_lock);
565
566 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
567 {
568 struct rtable *rt;
569
570 rt = rcu_dereference(fnhe->fnhe_rth_input);
571 if (rt) {
572 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
573 rt_free(rt);
574 }
575 rt = rcu_dereference(fnhe->fnhe_rth_output);
576 if (rt) {
577 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
578 rt_free(rt);
579 }
580 }
581
582 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
583 {
584 struct fib_nh_exception *fnhe, *oldest;
585
586 oldest = rcu_dereference(hash->chain);
587 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
588 fnhe = rcu_dereference(fnhe->fnhe_next)) {
589 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
590 oldest = fnhe;
591 }
592 fnhe_flush_routes(oldest);
593 return oldest;
594 }
595
596 static inline u32 fnhe_hashfun(__be32 daddr)
597 {
598 u32 hval;
599
600 hval = (__force u32) daddr;
601 hval ^= (hval >> 11) ^ (hval >> 22);
602
603 return hval & (FNHE_HASH_SIZE - 1);
604 }
605
606 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
607 {
608 rt->rt_pmtu = fnhe->fnhe_pmtu;
609 rt->dst.expires = fnhe->fnhe_expires;
610
611 if (fnhe->fnhe_gw) {
612 rt->rt_flags |= RTCF_REDIRECTED;
613 rt->rt_gateway = fnhe->fnhe_gw;
614 rt->rt_uses_gateway = 1;
615 }
616 }
617
618 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
619 u32 pmtu, unsigned long expires)
620 {
621 struct fnhe_hash_bucket *hash;
622 struct fib_nh_exception *fnhe;
623 struct rtable *rt;
624 unsigned int i;
625 int depth;
626 u32 hval = fnhe_hashfun(daddr);
627
628 spin_lock_bh(&fnhe_lock);
629
630 hash = nh->nh_exceptions;
631 if (!hash) {
632 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
633 if (!hash)
634 goto out_unlock;
635 nh->nh_exceptions = hash;
636 }
637
638 hash += hval;
639
640 depth = 0;
641 for (fnhe = rcu_dereference(hash->chain); fnhe;
642 fnhe = rcu_dereference(fnhe->fnhe_next)) {
643 if (fnhe->fnhe_daddr == daddr)
644 break;
645 depth++;
646 }
647
648 if (fnhe) {
649 if (gw)
650 fnhe->fnhe_gw = gw;
651 if (pmtu) {
652 fnhe->fnhe_pmtu = pmtu;
653 fnhe->fnhe_expires = max(1UL, expires);
654 }
655 /* Update all cached dsts too */
656 rt = rcu_dereference(fnhe->fnhe_rth_input);
657 if (rt)
658 fill_route_from_fnhe(rt, fnhe);
659 rt = rcu_dereference(fnhe->fnhe_rth_output);
660 if (rt)
661 fill_route_from_fnhe(rt, fnhe);
662 } else {
663 if (depth > FNHE_RECLAIM_DEPTH)
664 fnhe = fnhe_oldest(hash);
665 else {
666 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
667 if (!fnhe)
668 goto out_unlock;
669
670 fnhe->fnhe_next = hash->chain;
671 rcu_assign_pointer(hash->chain, fnhe);
672 }
673 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
674 fnhe->fnhe_daddr = daddr;
675 fnhe->fnhe_gw = gw;
676 fnhe->fnhe_pmtu = pmtu;
677 fnhe->fnhe_expires = expires;
678
679 /* Exception created; mark the cached routes for the nexthop
680 * stale, so anyone caching it rechecks if this exception
681 * applies to them.
682 */
683 rt = rcu_dereference(nh->nh_rth_input);
684 if (rt)
685 rt->dst.obsolete = DST_OBSOLETE_KILL;
686
687 for_each_possible_cpu(i) {
688 struct rtable __rcu **prt;
689 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
690 rt = rcu_dereference(*prt);
691 if (rt)
692 rt->dst.obsolete = DST_OBSOLETE_KILL;
693 }
694 }
695
696 fnhe->fnhe_stamp = jiffies;
697
698 out_unlock:
699 spin_unlock_bh(&fnhe_lock);
700 return;
701 }
702
703 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
704 bool kill_route)
705 {
706 __be32 new_gw = icmp_hdr(skb)->un.gateway;
707 __be32 old_gw = ip_hdr(skb)->saddr;
708 struct net_device *dev = skb->dev;
709 struct in_device *in_dev;
710 struct fib_result res;
711 struct neighbour *n;
712 struct net *net;
713
714 switch (icmp_hdr(skb)->code & 7) {
715 case ICMP_REDIR_NET:
716 case ICMP_REDIR_NETTOS:
717 case ICMP_REDIR_HOST:
718 case ICMP_REDIR_HOSTTOS:
719 break;
720
721 default:
722 return;
723 }
724
725 if (rt->rt_gateway != old_gw)
726 return;
727
728 in_dev = __in_dev_get_rcu(dev);
729 if (!in_dev)
730 return;
731
732 net = dev_net(dev);
733 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
734 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
735 ipv4_is_zeronet(new_gw))
736 goto reject_redirect;
737
738 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
739 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
740 goto reject_redirect;
741 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
742 goto reject_redirect;
743 } else {
744 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
745 goto reject_redirect;
746 }
747
748 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
749 if (n) {
750 if (!(n->nud_state & NUD_VALID)) {
751 neigh_event_send(n, NULL);
752 } else {
753 if (fib_lookup(net, fl4, &res) == 0) {
754 struct fib_nh *nh = &FIB_RES_NH(res);
755
756 update_or_create_fnhe(nh, fl4->daddr, new_gw,
757 0, 0);
758 }
759 if (kill_route)
760 rt->dst.obsolete = DST_OBSOLETE_KILL;
761 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
762 }
763 neigh_release(n);
764 }
765 return;
766
767 reject_redirect:
768 #ifdef CONFIG_IP_ROUTE_VERBOSE
769 if (IN_DEV_LOG_MARTIANS(in_dev)) {
770 const struct iphdr *iph = (const struct iphdr *) skb->data;
771 __be32 daddr = iph->daddr;
772 __be32 saddr = iph->saddr;
773
774 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
775 " Advised path = %pI4 -> %pI4\n",
776 &old_gw, dev->name, &new_gw,
777 &saddr, &daddr);
778 }
779 #endif
780 ;
781 }
782
783 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
784 {
785 struct rtable *rt;
786 struct flowi4 fl4;
787 const struct iphdr *iph = (const struct iphdr *) skb->data;
788 int oif = skb->dev->ifindex;
789 u8 tos = RT_TOS(iph->tos);
790 u8 prot = iph->protocol;
791 u32 mark = skb->mark;
792
793 rt = (struct rtable *) dst;
794
795 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
796 __ip_do_redirect(rt, skb, &fl4, true);
797 }
798
799 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
800 {
801 struct rtable *rt = (struct rtable *)dst;
802 struct dst_entry *ret = dst;
803
804 if (rt) {
805 if (dst->obsolete > 0) {
806 ip_rt_put(rt);
807 ret = NULL;
808 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
809 rt->dst.expires) {
810 ip_rt_put(rt);
811 ret = NULL;
812 }
813 }
814 return ret;
815 }
816
817 /*
818 * Algorithm:
819 * 1. The first ip_rt_redirect_number redirects are sent
820 * with exponential backoff, then we stop sending them at all,
821 * assuming that the host ignores our redirects.
822 * 2. If we did not see packets requiring redirects
823 * during ip_rt_redirect_silence, we assume that the host
824 * forgot redirected route and start to send redirects again.
825 *
826 * This algorithm is much cheaper and more intelligent than dumb load limiting
827 * in icmp.c.
828 *
829 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
830 * and "frag. need" (breaks PMTU discovery) in icmp.c.
831 */
832
833 void ip_rt_send_redirect(struct sk_buff *skb)
834 {
835 struct rtable *rt = skb_rtable(skb);
836 struct in_device *in_dev;
837 struct inet_peer *peer;
838 struct net *net;
839 int log_martians;
840
841 rcu_read_lock();
842 in_dev = __in_dev_get_rcu(rt->dst.dev);
843 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
844 rcu_read_unlock();
845 return;
846 }
847 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
848 rcu_read_unlock();
849
850 net = dev_net(rt->dst.dev);
851 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
852 if (!peer) {
853 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
854 rt_nexthop(rt, ip_hdr(skb)->daddr));
855 return;
856 }
857
858 /* No redirected packets during ip_rt_redirect_silence;
859 * reset the algorithm.
860 */
861 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
862 peer->rate_tokens = 0;
863
864 /* Too many ignored redirects; do not send anything
865 * set dst.rate_last to the last seen redirected packet.
866 */
867 if (peer->rate_tokens >= ip_rt_redirect_number) {
868 peer->rate_last = jiffies;
869 goto out_put_peer;
870 }
871
872 /* Check for load limit; set rate_last to the latest sent
873 * redirect.
874 */
875 if (peer->rate_tokens == 0 ||
876 time_after(jiffies,
877 (peer->rate_last +
878 (ip_rt_redirect_load << peer->rate_tokens)))) {
879 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
880
881 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
882 peer->rate_last = jiffies;
883 ++peer->rate_tokens;
884 #ifdef CONFIG_IP_ROUTE_VERBOSE
885 if (log_martians &&
886 peer->rate_tokens == ip_rt_redirect_number)
887 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
888 &ip_hdr(skb)->saddr, inet_iif(skb),
889 &ip_hdr(skb)->daddr, &gw);
890 #endif
891 }
892 out_put_peer:
893 inet_putpeer(peer);
894 }
895
896 static int ip_error(struct sk_buff *skb)
897 {
898 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
899 struct rtable *rt = skb_rtable(skb);
900 struct inet_peer *peer;
901 unsigned long now;
902 struct net *net;
903 bool send;
904 int code;
905
906 net = dev_net(rt->dst.dev);
907 if (!IN_DEV_FORWARD(in_dev)) {
908 switch (rt->dst.error) {
909 case EHOSTUNREACH:
910 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
911 break;
912
913 case ENETUNREACH:
914 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
915 break;
916 }
917 goto out;
918 }
919
920 switch (rt->dst.error) {
921 case EINVAL:
922 default:
923 goto out;
924 case EHOSTUNREACH:
925 code = ICMP_HOST_UNREACH;
926 break;
927 case ENETUNREACH:
928 code = ICMP_NET_UNREACH;
929 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
930 break;
931 case EACCES:
932 code = ICMP_PKT_FILTERED;
933 break;
934 }
935
936 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
937
938 send = true;
939 if (peer) {
940 now = jiffies;
941 peer->rate_tokens += now - peer->rate_last;
942 if (peer->rate_tokens > ip_rt_error_burst)
943 peer->rate_tokens = ip_rt_error_burst;
944 peer->rate_last = now;
945 if (peer->rate_tokens >= ip_rt_error_cost)
946 peer->rate_tokens -= ip_rt_error_cost;
947 else
948 send = false;
949 inet_putpeer(peer);
950 }
951 if (send)
952 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
953
954 out: kfree_skb(skb);
955 return 0;
956 }
957
958 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
959 {
960 struct dst_entry *dst = &rt->dst;
961 struct fib_result res;
962
963 if (dst_metric_locked(dst, RTAX_MTU))
964 return;
965
966 if (dst->dev->mtu < mtu)
967 return;
968
969 if (mtu < ip_rt_min_pmtu)
970 mtu = ip_rt_min_pmtu;
971
972 if (rt->rt_pmtu == mtu &&
973 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
974 return;
975
976 rcu_read_lock();
977 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
978 struct fib_nh *nh = &FIB_RES_NH(res);
979
980 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
981 jiffies + ip_rt_mtu_expires);
982 }
983 rcu_read_unlock();
984 }
985
986 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
987 struct sk_buff *skb, u32 mtu)
988 {
989 struct rtable *rt = (struct rtable *) dst;
990 struct flowi4 fl4;
991
992 ip_rt_build_flow_key(&fl4, sk, skb);
993 __ip_rt_update_pmtu(rt, &fl4, mtu);
994 }
995
996 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
997 int oif, u32 mark, u8 protocol, int flow_flags)
998 {
999 const struct iphdr *iph = (const struct iphdr *) skb->data;
1000 struct flowi4 fl4;
1001 struct rtable *rt;
1002
1003 __build_flow_key(&fl4, NULL, iph, oif,
1004 RT_TOS(iph->tos), protocol, mark, flow_flags);
1005 rt = __ip_route_output_key(net, &fl4);
1006 if (!IS_ERR(rt)) {
1007 __ip_rt_update_pmtu(rt, &fl4, mtu);
1008 ip_rt_put(rt);
1009 }
1010 }
1011 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1012
1013 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1014 {
1015 const struct iphdr *iph = (const struct iphdr *) skb->data;
1016 struct flowi4 fl4;
1017 struct rtable *rt;
1018
1019 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1020 rt = __ip_route_output_key(sock_net(sk), &fl4);
1021 if (!IS_ERR(rt)) {
1022 __ip_rt_update_pmtu(rt, &fl4, mtu);
1023 ip_rt_put(rt);
1024 }
1025 }
1026
1027 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1028 {
1029 const struct iphdr *iph = (const struct iphdr *) skb->data;
1030 struct flowi4 fl4;
1031 struct rtable *rt;
1032 struct dst_entry *dst;
1033 bool new = false;
1034
1035 bh_lock_sock(sk);
1036
1037 if (!ip_sk_accept_pmtu(sk))
1038 goto out;
1039
1040 rt = (struct rtable *) __sk_dst_get(sk);
1041
1042 if (sock_owned_by_user(sk) || !rt) {
1043 __ipv4_sk_update_pmtu(skb, sk, mtu);
1044 goto out;
1045 }
1046
1047 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1048
1049 if (!__sk_dst_check(sk, 0)) {
1050 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1051 if (IS_ERR(rt))
1052 goto out;
1053
1054 new = true;
1055 }
1056
1057 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1058
1059 dst = dst_check(&rt->dst, 0);
1060 if (!dst) {
1061 if (new)
1062 dst_release(&rt->dst);
1063
1064 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1065 if (IS_ERR(rt))
1066 goto out;
1067
1068 new = true;
1069 }
1070
1071 if (new)
1072 __sk_dst_set(sk, &rt->dst);
1073
1074 out:
1075 bh_unlock_sock(sk);
1076 }
1077 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1078
1079 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1080 int oif, u32 mark, u8 protocol, int flow_flags)
1081 {
1082 const struct iphdr *iph = (const struct iphdr *) skb->data;
1083 struct flowi4 fl4;
1084 struct rtable *rt;
1085
1086 __build_flow_key(&fl4, NULL, iph, oif,
1087 RT_TOS(iph->tos), protocol, mark, flow_flags);
1088 rt = __ip_route_output_key(net, &fl4);
1089 if (!IS_ERR(rt)) {
1090 __ip_do_redirect(rt, skb, &fl4, false);
1091 ip_rt_put(rt);
1092 }
1093 }
1094 EXPORT_SYMBOL_GPL(ipv4_redirect);
1095
1096 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1097 {
1098 const struct iphdr *iph = (const struct iphdr *) skb->data;
1099 struct flowi4 fl4;
1100 struct rtable *rt;
1101
1102 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1103 rt = __ip_route_output_key(sock_net(sk), &fl4);
1104 if (!IS_ERR(rt)) {
1105 __ip_do_redirect(rt, skb, &fl4, false);
1106 ip_rt_put(rt);
1107 }
1108 }
1109 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1110
1111 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1112 {
1113 struct rtable *rt = (struct rtable *) dst;
1114
1115 /* All IPV4 dsts are created with ->obsolete set to the value
1116 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1117 * into this function always.
1118 *
1119 * When a PMTU/redirect information update invalidates a route,
1120 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1121 * DST_OBSOLETE_DEAD by dst_free().
1122 */
1123 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1124 return NULL;
1125 return dst;
1126 }
1127
1128 static void ipv4_link_failure(struct sk_buff *skb)
1129 {
1130 struct rtable *rt;
1131
1132 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1133
1134 rt = skb_rtable(skb);
1135 if (rt)
1136 dst_set_expires(&rt->dst, 0);
1137 }
1138
1139 static int ip_rt_bug(struct sk_buff *skb)
1140 {
1141 pr_debug("%s: %pI4 -> %pI4, %s\n",
1142 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1143 skb->dev ? skb->dev->name : "?");
1144 kfree_skb(skb);
1145 WARN_ON(1);
1146 return 0;
1147 }
1148
1149 /*
1150 We do not cache source address of outgoing interface,
1151 because it is used only by IP RR, TS and SRR options,
1152 so that it out of fast path.
1153
1154 BTW remember: "addr" is allowed to be not aligned
1155 in IP options!
1156 */
1157
1158 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1159 {
1160 __be32 src;
1161
1162 if (rt_is_output_route(rt))
1163 src = ip_hdr(skb)->saddr;
1164 else {
1165 struct fib_result res;
1166 struct flowi4 fl4;
1167 struct iphdr *iph;
1168
1169 iph = ip_hdr(skb);
1170
1171 memset(&fl4, 0, sizeof(fl4));
1172 fl4.daddr = iph->daddr;
1173 fl4.saddr = iph->saddr;
1174 fl4.flowi4_tos = RT_TOS(iph->tos);
1175 fl4.flowi4_oif = rt->dst.dev->ifindex;
1176 fl4.flowi4_iif = skb->dev->ifindex;
1177 fl4.flowi4_mark = skb->mark;
1178
1179 rcu_read_lock();
1180 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1181 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1182 else
1183 src = inet_select_addr(rt->dst.dev,
1184 rt_nexthop(rt, iph->daddr),
1185 RT_SCOPE_UNIVERSE);
1186 rcu_read_unlock();
1187 }
1188 memcpy(addr, &src, 4);
1189 }
1190
1191 #ifdef CONFIG_IP_ROUTE_CLASSID
1192 static void set_class_tag(struct rtable *rt, u32 tag)
1193 {
1194 if (!(rt->dst.tclassid & 0xFFFF))
1195 rt->dst.tclassid |= tag & 0xFFFF;
1196 if (!(rt->dst.tclassid & 0xFFFF0000))
1197 rt->dst.tclassid |= tag & 0xFFFF0000;
1198 }
1199 #endif
1200
1201 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1202 {
1203 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1204
1205 if (advmss == 0) {
1206 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1207 ip_rt_min_advmss);
1208 if (advmss > 65535 - 40)
1209 advmss = 65535 - 40;
1210 }
1211 return advmss;
1212 }
1213
1214 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1215 {
1216 const struct rtable *rt = (const struct rtable *) dst;
1217 unsigned int mtu = rt->rt_pmtu;
1218
1219 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1220 mtu = dst_metric_raw(dst, RTAX_MTU);
1221
1222 if (mtu)
1223 return mtu;
1224
1225 mtu = dst->dev->mtu;
1226
1227 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1228 if (rt->rt_uses_gateway && mtu > 576)
1229 mtu = 576;
1230 }
1231
1232 return min_t(unsigned int, mtu, IP_MAX_MTU);
1233 }
1234
1235 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1236 {
1237 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1238 struct fib_nh_exception *fnhe;
1239 u32 hval;
1240
1241 if (!hash)
1242 return NULL;
1243
1244 hval = fnhe_hashfun(daddr);
1245
1246 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1247 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1248 if (fnhe->fnhe_daddr == daddr)
1249 return fnhe;
1250 }
1251 return NULL;
1252 }
1253
1254 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1255 __be32 daddr)
1256 {
1257 bool ret = false;
1258
1259 spin_lock_bh(&fnhe_lock);
1260
1261 if (daddr == fnhe->fnhe_daddr) {
1262 struct rtable __rcu **porig;
1263 struct rtable *orig;
1264 int genid = fnhe_genid(dev_net(rt->dst.dev));
1265
1266 if (rt_is_input_route(rt))
1267 porig = &fnhe->fnhe_rth_input;
1268 else
1269 porig = &fnhe->fnhe_rth_output;
1270 orig = rcu_dereference(*porig);
1271
1272 if (fnhe->fnhe_genid != genid) {
1273 fnhe->fnhe_genid = genid;
1274 fnhe->fnhe_gw = 0;
1275 fnhe->fnhe_pmtu = 0;
1276 fnhe->fnhe_expires = 0;
1277 fnhe_flush_routes(fnhe);
1278 orig = NULL;
1279 }
1280 fill_route_from_fnhe(rt, fnhe);
1281 if (!rt->rt_gateway)
1282 rt->rt_gateway = daddr;
1283
1284 if (!(rt->dst.flags & DST_NOCACHE)) {
1285 rcu_assign_pointer(*porig, rt);
1286 if (orig)
1287 rt_free(orig);
1288 ret = true;
1289 }
1290
1291 fnhe->fnhe_stamp = jiffies;
1292 }
1293 spin_unlock_bh(&fnhe_lock);
1294
1295 return ret;
1296 }
1297
1298 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1299 {
1300 struct rtable *orig, *prev, **p;
1301 bool ret = true;
1302
1303 if (rt_is_input_route(rt)) {
1304 p = (struct rtable **)&nh->nh_rth_input;
1305 } else {
1306 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1307 }
1308 orig = *p;
1309
1310 prev = cmpxchg(p, orig, rt);
1311 if (prev == orig) {
1312 if (orig)
1313 rt_free(orig);
1314 } else
1315 ret = false;
1316
1317 return ret;
1318 }
1319
1320 static DEFINE_SPINLOCK(rt_uncached_lock);
1321 static LIST_HEAD(rt_uncached_list);
1322
1323 static void rt_add_uncached_list(struct rtable *rt)
1324 {
1325 spin_lock_bh(&rt_uncached_lock);
1326 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1327 spin_unlock_bh(&rt_uncached_lock);
1328 }
1329
1330 static void ipv4_dst_destroy(struct dst_entry *dst)
1331 {
1332 struct rtable *rt = (struct rtable *) dst;
1333
1334 if (!list_empty(&rt->rt_uncached)) {
1335 spin_lock_bh(&rt_uncached_lock);
1336 list_del(&rt->rt_uncached);
1337 spin_unlock_bh(&rt_uncached_lock);
1338 }
1339 }
1340
1341 void rt_flush_dev(struct net_device *dev)
1342 {
1343 if (!list_empty(&rt_uncached_list)) {
1344 struct net *net = dev_net(dev);
1345 struct rtable *rt;
1346
1347 spin_lock_bh(&rt_uncached_lock);
1348 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1349 if (rt->dst.dev != dev)
1350 continue;
1351 rt->dst.dev = net->loopback_dev;
1352 dev_hold(rt->dst.dev);
1353 dev_put(dev);
1354 }
1355 spin_unlock_bh(&rt_uncached_lock);
1356 }
1357 }
1358
1359 static bool rt_cache_valid(const struct rtable *rt)
1360 {
1361 return rt &&
1362 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1363 !rt_is_expired(rt);
1364 }
1365
1366 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1367 const struct fib_result *res,
1368 struct fib_nh_exception *fnhe,
1369 struct fib_info *fi, u16 type, u32 itag)
1370 {
1371 bool cached = false;
1372
1373 if (fi) {
1374 struct fib_nh *nh = &FIB_RES_NH(*res);
1375
1376 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1377 rt->rt_gateway = nh->nh_gw;
1378 rt->rt_uses_gateway = 1;
1379 }
1380 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1381 #ifdef CONFIG_IP_ROUTE_CLASSID
1382 rt->dst.tclassid = nh->nh_tclassid;
1383 #endif
1384 if (unlikely(fnhe))
1385 cached = rt_bind_exception(rt, fnhe, daddr);
1386 else if (!(rt->dst.flags & DST_NOCACHE))
1387 cached = rt_cache_route(nh, rt);
1388 if (unlikely(!cached)) {
1389 /* Routes we intend to cache in nexthop exception or
1390 * FIB nexthop have the DST_NOCACHE bit clear.
1391 * However, if we are unsuccessful at storing this
1392 * route into the cache we really need to set it.
1393 */
1394 rt->dst.flags |= DST_NOCACHE;
1395 if (!rt->rt_gateway)
1396 rt->rt_gateway = daddr;
1397 rt_add_uncached_list(rt);
1398 }
1399 } else
1400 rt_add_uncached_list(rt);
1401
1402 #ifdef CONFIG_IP_ROUTE_CLASSID
1403 #ifdef CONFIG_IP_MULTIPLE_TABLES
1404 set_class_tag(rt, res->tclassid);
1405 #endif
1406 set_class_tag(rt, itag);
1407 #endif
1408 }
1409
1410 static struct rtable *rt_dst_alloc(struct net_device *dev,
1411 bool nopolicy, bool noxfrm, bool will_cache)
1412 {
1413 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1414 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1415 (nopolicy ? DST_NOPOLICY : 0) |
1416 (noxfrm ? DST_NOXFRM : 0));
1417 }
1418
1419 /* called in rcu_read_lock() section */
1420 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1421 u8 tos, struct net_device *dev, int our)
1422 {
1423 struct rtable *rth;
1424 struct in_device *in_dev = __in_dev_get_rcu(dev);
1425 u32 itag = 0;
1426 int err;
1427
1428 /* Primary sanity checks. */
1429
1430 if (in_dev == NULL)
1431 return -EINVAL;
1432
1433 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1434 skb->protocol != htons(ETH_P_IP))
1435 goto e_inval;
1436
1437 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1438 if (ipv4_is_loopback(saddr))
1439 goto e_inval;
1440
1441 if (ipv4_is_zeronet(saddr)) {
1442 if (!ipv4_is_local_multicast(daddr))
1443 goto e_inval;
1444 } else {
1445 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1446 in_dev, &itag);
1447 if (err < 0)
1448 goto e_err;
1449 }
1450 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1451 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1452 if (!rth)
1453 goto e_nobufs;
1454
1455 #ifdef CONFIG_IP_ROUTE_CLASSID
1456 rth->dst.tclassid = itag;
1457 #endif
1458 rth->dst.output = ip_rt_bug;
1459
1460 rth->rt_genid = rt_genid_ipv4(dev_net(dev));
1461 rth->rt_flags = RTCF_MULTICAST;
1462 rth->rt_type = RTN_MULTICAST;
1463 rth->rt_is_input= 1;
1464 rth->rt_iif = 0;
1465 rth->rt_pmtu = 0;
1466 rth->rt_gateway = 0;
1467 rth->rt_uses_gateway = 0;
1468 INIT_LIST_HEAD(&rth->rt_uncached);
1469 if (our) {
1470 rth->dst.input= ip_local_deliver;
1471 rth->rt_flags |= RTCF_LOCAL;
1472 }
1473
1474 #ifdef CONFIG_IP_MROUTE
1475 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1476 rth->dst.input = ip_mr_input;
1477 #endif
1478 RT_CACHE_STAT_INC(in_slow_mc);
1479
1480 skb_dst_set(skb, &rth->dst);
1481 return 0;
1482
1483 e_nobufs:
1484 return -ENOBUFS;
1485 e_inval:
1486 return -EINVAL;
1487 e_err:
1488 return err;
1489 }
1490
1491
1492 static void ip_handle_martian_source(struct net_device *dev,
1493 struct in_device *in_dev,
1494 struct sk_buff *skb,
1495 __be32 daddr,
1496 __be32 saddr)
1497 {
1498 RT_CACHE_STAT_INC(in_martian_src);
1499 #ifdef CONFIG_IP_ROUTE_VERBOSE
1500 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1501 /*
1502 * RFC1812 recommendation, if source is martian,
1503 * the only hint is MAC header.
1504 */
1505 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1506 &daddr, &saddr, dev->name);
1507 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1508 print_hex_dump(KERN_WARNING, "ll header: ",
1509 DUMP_PREFIX_OFFSET, 16, 1,
1510 skb_mac_header(skb),
1511 dev->hard_header_len, true);
1512 }
1513 }
1514 #endif
1515 }
1516
1517 /* called in rcu_read_lock() section */
1518 static int __mkroute_input(struct sk_buff *skb,
1519 const struct fib_result *res,
1520 struct in_device *in_dev,
1521 __be32 daddr, __be32 saddr, u32 tos)
1522 {
1523 struct fib_nh_exception *fnhe;
1524 struct rtable *rth;
1525 int err;
1526 struct in_device *out_dev;
1527 unsigned int flags = 0;
1528 bool do_cache;
1529 u32 itag;
1530
1531 /* get a working reference to the output device */
1532 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1533 if (out_dev == NULL) {
1534 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1535 return -EINVAL;
1536 }
1537
1538 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1539 in_dev->dev, in_dev, &itag);
1540 if (err < 0) {
1541 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1542 saddr);
1543
1544 goto cleanup;
1545 }
1546
1547 do_cache = res->fi && !itag;
1548 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1549 (IN_DEV_SHARED_MEDIA(out_dev) ||
1550 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) {
1551 flags |= RTCF_DOREDIRECT;
1552 do_cache = false;
1553 }
1554
1555 if (skb->protocol != htons(ETH_P_IP)) {
1556 /* Not IP (i.e. ARP). Do not create route, if it is
1557 * invalid for proxy arp. DNAT routes are always valid.
1558 *
1559 * Proxy arp feature have been extended to allow, ARP
1560 * replies back to the same interface, to support
1561 * Private VLAN switch technologies. See arp.c.
1562 */
1563 if (out_dev == in_dev &&
1564 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1565 err = -EINVAL;
1566 goto cleanup;
1567 }
1568 }
1569
1570 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1571 if (do_cache) {
1572 if (fnhe != NULL)
1573 rth = rcu_dereference(fnhe->fnhe_rth_input);
1574 else
1575 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1576
1577 if (rt_cache_valid(rth)) {
1578 skb_dst_set_noref(skb, &rth->dst);
1579 goto out;
1580 }
1581 }
1582
1583 rth = rt_dst_alloc(out_dev->dev,
1584 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1585 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1586 if (!rth) {
1587 err = -ENOBUFS;
1588 goto cleanup;
1589 }
1590
1591 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev));
1592 rth->rt_flags = flags;
1593 rth->rt_type = res->type;
1594 rth->rt_is_input = 1;
1595 rth->rt_iif = 0;
1596 rth->rt_pmtu = 0;
1597 rth->rt_gateway = 0;
1598 rth->rt_uses_gateway = 0;
1599 INIT_LIST_HEAD(&rth->rt_uncached);
1600 RT_CACHE_STAT_INC(in_slow_tot);
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 if (!IN_DEV_FORWARD(in_dev))
1701 err = -EHOSTUNREACH;
1702 goto no_route;
1703 }
1704
1705 if (res.type == RTN_BROADCAST)
1706 goto brd_input;
1707
1708 if (res.type == RTN_LOCAL) {
1709 err = fib_validate_source(skb, saddr, daddr, tos,
1710 LOOPBACK_IFINDEX,
1711 dev, in_dev, &itag);
1712 if (err < 0)
1713 goto martian_source_keep_err;
1714 goto local_input;
1715 }
1716
1717 if (!IN_DEV_FORWARD(in_dev)) {
1718 err = -EHOSTUNREACH;
1719 goto no_route;
1720 }
1721 if (res.type != RTN_UNICAST)
1722 goto martian_destination;
1723
1724 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1725 out: return err;
1726
1727 brd_input:
1728 if (skb->protocol != htons(ETH_P_IP))
1729 goto e_inval;
1730
1731 if (!ipv4_is_zeronet(saddr)) {
1732 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1733 in_dev, &itag);
1734 if (err < 0)
1735 goto martian_source_keep_err;
1736 }
1737 flags |= RTCF_BROADCAST;
1738 res.type = RTN_BROADCAST;
1739 RT_CACHE_STAT_INC(in_brd);
1740
1741 local_input:
1742 do_cache = false;
1743 if (res.fi) {
1744 if (!itag) {
1745 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1746 if (rt_cache_valid(rth)) {
1747 skb_dst_set_noref(skb, &rth->dst);
1748 err = 0;
1749 goto out;
1750 }
1751 do_cache = true;
1752 }
1753 }
1754
1755 rth = rt_dst_alloc(net->loopback_dev,
1756 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1757 if (!rth)
1758 goto e_nobufs;
1759
1760 rth->dst.input= ip_local_deliver;
1761 rth->dst.output= ip_rt_bug;
1762 #ifdef CONFIG_IP_ROUTE_CLASSID
1763 rth->dst.tclassid = itag;
1764 #endif
1765
1766 rth->rt_genid = rt_genid_ipv4(net);
1767 rth->rt_flags = flags|RTCF_LOCAL;
1768 rth->rt_type = res.type;
1769 rth->rt_is_input = 1;
1770 rth->rt_iif = 0;
1771 rth->rt_pmtu = 0;
1772 rth->rt_gateway = 0;
1773 rth->rt_uses_gateway = 0;
1774 INIT_LIST_HEAD(&rth->rt_uncached);
1775 RT_CACHE_STAT_INC(in_slow_tot);
1776 if (res.type == RTN_UNREACHABLE) {
1777 rth->dst.input= ip_error;
1778 rth->dst.error= -err;
1779 rth->rt_flags &= ~RTCF_LOCAL;
1780 }
1781 if (do_cache) {
1782 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1783 rth->dst.flags |= DST_NOCACHE;
1784 rt_add_uncached_list(rth);
1785 }
1786 }
1787 skb_dst_set(skb, &rth->dst);
1788 err = 0;
1789 goto out;
1790
1791 no_route:
1792 RT_CACHE_STAT_INC(in_no_route);
1793 res.type = RTN_UNREACHABLE;
1794 if (err == -ESRCH)
1795 err = -ENETUNREACH;
1796 goto local_input;
1797
1798 /*
1799 * Do not cache martian addresses: they should be logged (RFC1812)
1800 */
1801 martian_destination:
1802 RT_CACHE_STAT_INC(in_martian_dst);
1803 #ifdef CONFIG_IP_ROUTE_VERBOSE
1804 if (IN_DEV_LOG_MARTIANS(in_dev))
1805 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1806 &daddr, &saddr, dev->name);
1807 #endif
1808
1809 e_inval:
1810 err = -EINVAL;
1811 goto out;
1812
1813 e_nobufs:
1814 err = -ENOBUFS;
1815 goto out;
1816
1817 martian_source:
1818 err = -EINVAL;
1819 martian_source_keep_err:
1820 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1821 goto out;
1822 }
1823
1824 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1825 u8 tos, struct net_device *dev)
1826 {
1827 int res;
1828
1829 rcu_read_lock();
1830
1831 /* Multicast recognition logic is moved from route cache to here.
1832 The problem was that too many Ethernet cards have broken/missing
1833 hardware multicast filters :-( As result the host on multicasting
1834 network acquires a lot of useless route cache entries, sort of
1835 SDR messages from all the world. Now we try to get rid of them.
1836 Really, provided software IP multicast filter is organized
1837 reasonably (at least, hashed), it does not result in a slowdown
1838 comparing with route cache reject entries.
1839 Note, that multicast routers are not affected, because
1840 route cache entry is created eventually.
1841 */
1842 if (ipv4_is_multicast(daddr)) {
1843 struct in_device *in_dev = __in_dev_get_rcu(dev);
1844
1845 if (in_dev) {
1846 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1847 ip_hdr(skb)->protocol);
1848 if (our
1849 #ifdef CONFIG_IP_MROUTE
1850 ||
1851 (!ipv4_is_local_multicast(daddr) &&
1852 IN_DEV_MFORWARD(in_dev))
1853 #endif
1854 ) {
1855 int res = ip_route_input_mc(skb, daddr, saddr,
1856 tos, dev, our);
1857 rcu_read_unlock();
1858 return res;
1859 }
1860 }
1861 rcu_read_unlock();
1862 return -EINVAL;
1863 }
1864 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1865 rcu_read_unlock();
1866 return res;
1867 }
1868 EXPORT_SYMBOL(ip_route_input_noref);
1869
1870 /* called with rcu_read_lock() */
1871 static struct rtable *__mkroute_output(const struct fib_result *res,
1872 const struct flowi4 *fl4, int orig_oif,
1873 struct net_device *dev_out,
1874 unsigned int flags)
1875 {
1876 struct fib_info *fi = res->fi;
1877 struct fib_nh_exception *fnhe;
1878 struct in_device *in_dev;
1879 u16 type = res->type;
1880 struct rtable *rth;
1881 bool do_cache;
1882
1883 in_dev = __in_dev_get_rcu(dev_out);
1884 if (!in_dev)
1885 return ERR_PTR(-EINVAL);
1886
1887 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1888 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1889 return ERR_PTR(-EINVAL);
1890
1891 if (ipv4_is_lbcast(fl4->daddr))
1892 type = RTN_BROADCAST;
1893 else if (ipv4_is_multicast(fl4->daddr))
1894 type = RTN_MULTICAST;
1895 else if (ipv4_is_zeronet(fl4->daddr))
1896 return ERR_PTR(-EINVAL);
1897
1898 if (dev_out->flags & IFF_LOOPBACK)
1899 flags |= RTCF_LOCAL;
1900
1901 do_cache = true;
1902 if (type == RTN_BROADCAST) {
1903 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1904 fi = NULL;
1905 } else if (type == RTN_MULTICAST) {
1906 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1907 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1908 fl4->flowi4_proto))
1909 flags &= ~RTCF_LOCAL;
1910 else
1911 do_cache = false;
1912 /* If multicast route do not exist use
1913 * default one, but do not gateway in this case.
1914 * Yes, it is hack.
1915 */
1916 if (fi && res->prefixlen < 4)
1917 fi = NULL;
1918 }
1919
1920 fnhe = NULL;
1921 do_cache &= fi != NULL;
1922 if (do_cache) {
1923 struct rtable __rcu **prth;
1924 struct fib_nh *nh = &FIB_RES_NH(*res);
1925
1926 fnhe = find_exception(nh, fl4->daddr);
1927 if (fnhe)
1928 prth = &fnhe->fnhe_rth_output;
1929 else {
1930 if (unlikely(fl4->flowi4_flags &
1931 FLOWI_FLAG_KNOWN_NH &&
1932 !(nh->nh_gw &&
1933 nh->nh_scope == RT_SCOPE_LINK))) {
1934 do_cache = false;
1935 goto add;
1936 }
1937 prth = __this_cpu_ptr(nh->nh_pcpu_rth_output);
1938 }
1939 rth = rcu_dereference(*prth);
1940 if (rt_cache_valid(rth)) {
1941 dst_hold(&rth->dst);
1942 return rth;
1943 }
1944 }
1945
1946 add:
1947 rth = rt_dst_alloc(dev_out,
1948 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1949 IN_DEV_CONF_GET(in_dev, NOXFRM),
1950 do_cache);
1951 if (!rth)
1952 return ERR_PTR(-ENOBUFS);
1953
1954 rth->dst.output = ip_output;
1955
1956 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out));
1957 rth->rt_flags = flags;
1958 rth->rt_type = type;
1959 rth->rt_is_input = 0;
1960 rth->rt_iif = orig_oif ? : 0;
1961 rth->rt_pmtu = 0;
1962 rth->rt_gateway = 0;
1963 rth->rt_uses_gateway = 0;
1964 INIT_LIST_HEAD(&rth->rt_uncached);
1965
1966 RT_CACHE_STAT_INC(out_slow_tot);
1967
1968 if (flags & RTCF_LOCAL)
1969 rth->dst.input = ip_local_deliver;
1970 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1971 if (flags & RTCF_LOCAL &&
1972 !(dev_out->flags & IFF_LOOPBACK)) {
1973 rth->dst.output = ip_mc_output;
1974 RT_CACHE_STAT_INC(out_slow_mc);
1975 }
1976 #ifdef CONFIG_IP_MROUTE
1977 if (type == RTN_MULTICAST) {
1978 if (IN_DEV_MFORWARD(in_dev) &&
1979 !ipv4_is_local_multicast(fl4->daddr)) {
1980 rth->dst.input = ip_mr_input;
1981 rth->dst.output = ip_mc_output;
1982 }
1983 }
1984 #endif
1985 }
1986
1987 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1988
1989 return rth;
1990 }
1991
1992 /*
1993 * Major route resolver routine.
1994 */
1995
1996 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1997 {
1998 struct net_device *dev_out = NULL;
1999 __u8 tos = RT_FL_TOS(fl4);
2000 unsigned int flags = 0;
2001 struct fib_result res;
2002 struct rtable *rth;
2003 int orig_oif;
2004
2005 res.tclassid = 0;
2006 res.fi = NULL;
2007 res.table = NULL;
2008
2009 orig_oif = fl4->flowi4_oif;
2010
2011 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2012 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2013 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2014 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2015
2016 rcu_read_lock();
2017 if (fl4->saddr) {
2018 rth = ERR_PTR(-EINVAL);
2019 if (ipv4_is_multicast(fl4->saddr) ||
2020 ipv4_is_lbcast(fl4->saddr) ||
2021 ipv4_is_zeronet(fl4->saddr))
2022 goto out;
2023
2024 /* I removed check for oif == dev_out->oif here.
2025 It was wrong for two reasons:
2026 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2027 is assigned to multiple interfaces.
2028 2. Moreover, we are allowed to send packets with saddr
2029 of another iface. --ANK
2030 */
2031
2032 if (fl4->flowi4_oif == 0 &&
2033 (ipv4_is_multicast(fl4->daddr) ||
2034 ipv4_is_lbcast(fl4->daddr))) {
2035 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2036 dev_out = __ip_dev_find(net, fl4->saddr, false);
2037 if (dev_out == NULL)
2038 goto out;
2039
2040 /* Special hack: user can direct multicasts
2041 and limited broadcast via necessary interface
2042 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2043 This hack is not just for fun, it allows
2044 vic,vat and friends to work.
2045 They bind socket to loopback, set ttl to zero
2046 and expect that it will work.
2047 From the viewpoint of routing cache they are broken,
2048 because we are not allowed to build multicast path
2049 with loopback source addr (look, routing cache
2050 cannot know, that ttl is zero, so that packet
2051 will not leave this host and route is valid).
2052 Luckily, this hack is good workaround.
2053 */
2054
2055 fl4->flowi4_oif = dev_out->ifindex;
2056 goto make_route;
2057 }
2058
2059 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2060 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2061 if (!__ip_dev_find(net, fl4->saddr, false))
2062 goto out;
2063 }
2064 }
2065
2066
2067 if (fl4->flowi4_oif) {
2068 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2069 rth = ERR_PTR(-ENODEV);
2070 if (dev_out == NULL)
2071 goto out;
2072
2073 /* RACE: Check return value of inet_select_addr instead. */
2074 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2075 rth = ERR_PTR(-ENETUNREACH);
2076 goto out;
2077 }
2078 if (ipv4_is_local_multicast(fl4->daddr) ||
2079 ipv4_is_lbcast(fl4->daddr)) {
2080 if (!fl4->saddr)
2081 fl4->saddr = inet_select_addr(dev_out, 0,
2082 RT_SCOPE_LINK);
2083 goto make_route;
2084 }
2085 if (!fl4->saddr) {
2086 if (ipv4_is_multicast(fl4->daddr))
2087 fl4->saddr = inet_select_addr(dev_out, 0,
2088 fl4->flowi4_scope);
2089 else if (!fl4->daddr)
2090 fl4->saddr = inet_select_addr(dev_out, 0,
2091 RT_SCOPE_HOST);
2092 }
2093 }
2094
2095 if (!fl4->daddr) {
2096 fl4->daddr = fl4->saddr;
2097 if (!fl4->daddr)
2098 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2099 dev_out = net->loopback_dev;
2100 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2101 res.type = RTN_LOCAL;
2102 flags |= RTCF_LOCAL;
2103 goto make_route;
2104 }
2105
2106 if (fib_lookup(net, fl4, &res)) {
2107 res.fi = NULL;
2108 res.table = NULL;
2109 if (fl4->flowi4_oif) {
2110 /* Apparently, routing tables are wrong. Assume,
2111 that the destination is on link.
2112
2113 WHY? DW.
2114 Because we are allowed to send to iface
2115 even if it has NO routes and NO assigned
2116 addresses. When oif is specified, routing
2117 tables are looked up with only one purpose:
2118 to catch if destination is gatewayed, rather than
2119 direct. Moreover, if MSG_DONTROUTE is set,
2120 we send packet, ignoring both routing tables
2121 and ifaddr state. --ANK
2122
2123
2124 We could make it even if oif is unknown,
2125 likely IPv6, but we do not.
2126 */
2127
2128 if (fl4->saddr == 0)
2129 fl4->saddr = inet_select_addr(dev_out, 0,
2130 RT_SCOPE_LINK);
2131 res.type = RTN_UNICAST;
2132 goto make_route;
2133 }
2134 rth = ERR_PTR(-ENETUNREACH);
2135 goto out;
2136 }
2137
2138 if (res.type == RTN_LOCAL) {
2139 if (!fl4->saddr) {
2140 if (res.fi->fib_prefsrc)
2141 fl4->saddr = res.fi->fib_prefsrc;
2142 else
2143 fl4->saddr = fl4->daddr;
2144 }
2145 dev_out = net->loopback_dev;
2146 fl4->flowi4_oif = dev_out->ifindex;
2147 flags |= RTCF_LOCAL;
2148 goto make_route;
2149 }
2150
2151 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2152 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2153 fib_select_multipath(&res);
2154 else
2155 #endif
2156 if (!res.prefixlen &&
2157 res.table->tb_num_default > 1 &&
2158 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2159 fib_select_default(&res);
2160
2161 if (!fl4->saddr)
2162 fl4->saddr = FIB_RES_PREFSRC(net, res);
2163
2164 dev_out = FIB_RES_DEV(res);
2165 fl4->flowi4_oif = dev_out->ifindex;
2166
2167
2168 make_route:
2169 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2170
2171 out:
2172 rcu_read_unlock();
2173 return rth;
2174 }
2175 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2176
2177 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2178 {
2179 return NULL;
2180 }
2181
2182 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2183 {
2184 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2185
2186 return mtu ? : dst->dev->mtu;
2187 }
2188
2189 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2190 struct sk_buff *skb, u32 mtu)
2191 {
2192 }
2193
2194 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2195 struct sk_buff *skb)
2196 {
2197 }
2198
2199 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2200 unsigned long old)
2201 {
2202 return NULL;
2203 }
2204
2205 static struct dst_ops ipv4_dst_blackhole_ops = {
2206 .family = AF_INET,
2207 .protocol = cpu_to_be16(ETH_P_IP),
2208 .check = ipv4_blackhole_dst_check,
2209 .mtu = ipv4_blackhole_mtu,
2210 .default_advmss = ipv4_default_advmss,
2211 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2212 .redirect = ipv4_rt_blackhole_redirect,
2213 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2214 .neigh_lookup = ipv4_neigh_lookup,
2215 };
2216
2217 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2218 {
2219 struct rtable *ort = (struct rtable *) dst_orig;
2220 struct rtable *rt;
2221
2222 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2223 if (rt) {
2224 struct dst_entry *new = &rt->dst;
2225
2226 new->__use = 1;
2227 new->input = dst_discard;
2228 new->output = dst_discard;
2229
2230 new->dev = ort->dst.dev;
2231 if (new->dev)
2232 dev_hold(new->dev);
2233
2234 rt->rt_is_input = ort->rt_is_input;
2235 rt->rt_iif = ort->rt_iif;
2236 rt->rt_pmtu = ort->rt_pmtu;
2237
2238 rt->rt_genid = rt_genid_ipv4(net);
2239 rt->rt_flags = ort->rt_flags;
2240 rt->rt_type = ort->rt_type;
2241 rt->rt_gateway = ort->rt_gateway;
2242 rt->rt_uses_gateway = ort->rt_uses_gateway;
2243
2244 INIT_LIST_HEAD(&rt->rt_uncached);
2245
2246 dst_free(new);
2247 }
2248
2249 dst_release(dst_orig);
2250
2251 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2252 }
2253
2254 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2255 struct sock *sk)
2256 {
2257 struct rtable *rt = __ip_route_output_key(net, flp4);
2258
2259 if (IS_ERR(rt))
2260 return rt;
2261
2262 if (flp4->flowi4_proto)
2263 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2264 flowi4_to_flowi(flp4),
2265 sk, 0);
2266
2267 return rt;
2268 }
2269 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2270
2271 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2272 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2273 u32 seq, int event, int nowait, unsigned int flags)
2274 {
2275 struct rtable *rt = skb_rtable(skb);
2276 struct rtmsg *r;
2277 struct nlmsghdr *nlh;
2278 unsigned long expires = 0;
2279 u32 error;
2280 u32 metrics[RTAX_MAX];
2281
2282 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2283 if (nlh == NULL)
2284 return -EMSGSIZE;
2285
2286 r = nlmsg_data(nlh);
2287 r->rtm_family = AF_INET;
2288 r->rtm_dst_len = 32;
2289 r->rtm_src_len = 0;
2290 r->rtm_tos = fl4->flowi4_tos;
2291 r->rtm_table = RT_TABLE_MAIN;
2292 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2293 goto nla_put_failure;
2294 r->rtm_type = rt->rt_type;
2295 r->rtm_scope = RT_SCOPE_UNIVERSE;
2296 r->rtm_protocol = RTPROT_UNSPEC;
2297 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2298 if (rt->rt_flags & RTCF_NOTIFY)
2299 r->rtm_flags |= RTM_F_NOTIFY;
2300
2301 if (nla_put_be32(skb, RTA_DST, dst))
2302 goto nla_put_failure;
2303 if (src) {
2304 r->rtm_src_len = 32;
2305 if (nla_put_be32(skb, RTA_SRC, src))
2306 goto nla_put_failure;
2307 }
2308 if (rt->dst.dev &&
2309 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2310 goto nla_put_failure;
2311 #ifdef CONFIG_IP_ROUTE_CLASSID
2312 if (rt->dst.tclassid &&
2313 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2314 goto nla_put_failure;
2315 #endif
2316 if (!rt_is_input_route(rt) &&
2317 fl4->saddr != src) {
2318 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2319 goto nla_put_failure;
2320 }
2321 if (rt->rt_uses_gateway &&
2322 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2323 goto nla_put_failure;
2324
2325 expires = rt->dst.expires;
2326 if (expires) {
2327 unsigned long now = jiffies;
2328
2329 if (time_before(now, expires))
2330 expires -= now;
2331 else
2332 expires = 0;
2333 }
2334
2335 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2336 if (rt->rt_pmtu && expires)
2337 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2338 if (rtnetlink_put_metrics(skb, metrics) < 0)
2339 goto nla_put_failure;
2340
2341 if (fl4->flowi4_mark &&
2342 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2343 goto nla_put_failure;
2344
2345 error = rt->dst.error;
2346
2347 if (rt_is_input_route(rt)) {
2348 #ifdef CONFIG_IP_MROUTE
2349 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2350 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2351 int err = ipmr_get_route(net, skb,
2352 fl4->saddr, fl4->daddr,
2353 r, nowait);
2354 if (err <= 0) {
2355 if (!nowait) {
2356 if (err == 0)
2357 return 0;
2358 goto nla_put_failure;
2359 } else {
2360 if (err == -EMSGSIZE)
2361 goto nla_put_failure;
2362 error = err;
2363 }
2364 }
2365 } else
2366 #endif
2367 if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
2368 goto nla_put_failure;
2369 }
2370
2371 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2372 goto nla_put_failure;
2373
2374 return nlmsg_end(skb, nlh);
2375
2376 nla_put_failure:
2377 nlmsg_cancel(skb, nlh);
2378 return -EMSGSIZE;
2379 }
2380
2381 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2382 {
2383 struct net *net = sock_net(in_skb->sk);
2384 struct rtmsg *rtm;
2385 struct nlattr *tb[RTA_MAX+1];
2386 struct rtable *rt = NULL;
2387 struct flowi4 fl4;
2388 __be32 dst = 0;
2389 __be32 src = 0;
2390 u32 iif;
2391 int err;
2392 int mark;
2393 struct sk_buff *skb;
2394
2395 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2396 if (err < 0)
2397 goto errout;
2398
2399 rtm = nlmsg_data(nlh);
2400
2401 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2402 if (skb == NULL) {
2403 err = -ENOBUFS;
2404 goto errout;
2405 }
2406
2407 /* Reserve room for dummy headers, this skb can pass
2408 through good chunk of routing engine.
2409 */
2410 skb_reset_mac_header(skb);
2411 skb_reset_network_header(skb);
2412
2413 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2414 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2415 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2416
2417 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2418 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2419 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2420 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2421
2422 memset(&fl4, 0, sizeof(fl4));
2423 fl4.daddr = dst;
2424 fl4.saddr = src;
2425 fl4.flowi4_tos = rtm->rtm_tos;
2426 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2427 fl4.flowi4_mark = mark;
2428
2429 if (iif) {
2430 struct net_device *dev;
2431
2432 dev = __dev_get_by_index(net, iif);
2433 if (dev == NULL) {
2434 err = -ENODEV;
2435 goto errout_free;
2436 }
2437
2438 skb->protocol = htons(ETH_P_IP);
2439 skb->dev = dev;
2440 skb->mark = mark;
2441 local_bh_disable();
2442 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2443 local_bh_enable();
2444
2445 rt = skb_rtable(skb);
2446 if (err == 0 && rt->dst.error)
2447 err = -rt->dst.error;
2448 } else {
2449 rt = ip_route_output_key(net, &fl4);
2450
2451 err = 0;
2452 if (IS_ERR(rt))
2453 err = PTR_ERR(rt);
2454 }
2455
2456 if (err)
2457 goto errout_free;
2458
2459 skb_dst_set(skb, &rt->dst);
2460 if (rtm->rtm_flags & RTM_F_NOTIFY)
2461 rt->rt_flags |= RTCF_NOTIFY;
2462
2463 err = rt_fill_info(net, dst, src, &fl4, skb,
2464 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2465 RTM_NEWROUTE, 0, 0);
2466 if (err <= 0)
2467 goto errout_free;
2468
2469 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2470 errout:
2471 return err;
2472
2473 errout_free:
2474 kfree_skb(skb);
2475 goto errout;
2476 }
2477
2478 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2479 {
2480 return skb->len;
2481 }
2482
2483 void ip_rt_multicast_event(struct in_device *in_dev)
2484 {
2485 rt_cache_flush(dev_net(in_dev->dev));
2486 }
2487
2488 #ifdef CONFIG_SYSCTL
2489 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2490 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2491 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2492 static int ip_rt_gc_elasticity __read_mostly = 8;
2493
2494 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2495 void __user *buffer,
2496 size_t *lenp, loff_t *ppos)
2497 {
2498 struct net *net = (struct net *)__ctl->extra1;
2499
2500 if (write) {
2501 rt_cache_flush(net);
2502 fnhe_genid_bump(net);
2503 return 0;
2504 }
2505
2506 return -EINVAL;
2507 }
2508
2509 static struct ctl_table ipv4_route_table[] = {
2510 {
2511 .procname = "gc_thresh",
2512 .data = &ipv4_dst_ops.gc_thresh,
2513 .maxlen = sizeof(int),
2514 .mode = 0644,
2515 .proc_handler = proc_dointvec,
2516 },
2517 {
2518 .procname = "max_size",
2519 .data = &ip_rt_max_size,
2520 .maxlen = sizeof(int),
2521 .mode = 0644,
2522 .proc_handler = proc_dointvec,
2523 },
2524 {
2525 /* Deprecated. Use gc_min_interval_ms */
2526
2527 .procname = "gc_min_interval",
2528 .data = &ip_rt_gc_min_interval,
2529 .maxlen = sizeof(int),
2530 .mode = 0644,
2531 .proc_handler = proc_dointvec_jiffies,
2532 },
2533 {
2534 .procname = "gc_min_interval_ms",
2535 .data = &ip_rt_gc_min_interval,
2536 .maxlen = sizeof(int),
2537 .mode = 0644,
2538 .proc_handler = proc_dointvec_ms_jiffies,
2539 },
2540 {
2541 .procname = "gc_timeout",
2542 .data = &ip_rt_gc_timeout,
2543 .maxlen = sizeof(int),
2544 .mode = 0644,
2545 .proc_handler = proc_dointvec_jiffies,
2546 },
2547 {
2548 .procname = "gc_interval",
2549 .data = &ip_rt_gc_interval,
2550 .maxlen = sizeof(int),
2551 .mode = 0644,
2552 .proc_handler = proc_dointvec_jiffies,
2553 },
2554 {
2555 .procname = "redirect_load",
2556 .data = &ip_rt_redirect_load,
2557 .maxlen = sizeof(int),
2558 .mode = 0644,
2559 .proc_handler = proc_dointvec,
2560 },
2561 {
2562 .procname = "redirect_number",
2563 .data = &ip_rt_redirect_number,
2564 .maxlen = sizeof(int),
2565 .mode = 0644,
2566 .proc_handler = proc_dointvec,
2567 },
2568 {
2569 .procname = "redirect_silence",
2570 .data = &ip_rt_redirect_silence,
2571 .maxlen = sizeof(int),
2572 .mode = 0644,
2573 .proc_handler = proc_dointvec,
2574 },
2575 {
2576 .procname = "error_cost",
2577 .data = &ip_rt_error_cost,
2578 .maxlen = sizeof(int),
2579 .mode = 0644,
2580 .proc_handler = proc_dointvec,
2581 },
2582 {
2583 .procname = "error_burst",
2584 .data = &ip_rt_error_burst,
2585 .maxlen = sizeof(int),
2586 .mode = 0644,
2587 .proc_handler = proc_dointvec,
2588 },
2589 {
2590 .procname = "gc_elasticity",
2591 .data = &ip_rt_gc_elasticity,
2592 .maxlen = sizeof(int),
2593 .mode = 0644,
2594 .proc_handler = proc_dointvec,
2595 },
2596 {
2597 .procname = "mtu_expires",
2598 .data = &ip_rt_mtu_expires,
2599 .maxlen = sizeof(int),
2600 .mode = 0644,
2601 .proc_handler = proc_dointvec_jiffies,
2602 },
2603 {
2604 .procname = "min_pmtu",
2605 .data = &ip_rt_min_pmtu,
2606 .maxlen = sizeof(int),
2607 .mode = 0644,
2608 .proc_handler = proc_dointvec,
2609 },
2610 {
2611 .procname = "min_adv_mss",
2612 .data = &ip_rt_min_advmss,
2613 .maxlen = sizeof(int),
2614 .mode = 0644,
2615 .proc_handler = proc_dointvec,
2616 },
2617 { }
2618 };
2619
2620 static struct ctl_table ipv4_route_flush_table[] = {
2621 {
2622 .procname = "flush",
2623 .maxlen = sizeof(int),
2624 .mode = 0200,
2625 .proc_handler = ipv4_sysctl_rtcache_flush,
2626 },
2627 { },
2628 };
2629
2630 static __net_init int sysctl_route_net_init(struct net *net)
2631 {
2632 struct ctl_table *tbl;
2633
2634 tbl = ipv4_route_flush_table;
2635 if (!net_eq(net, &init_net)) {
2636 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2637 if (tbl == NULL)
2638 goto err_dup;
2639
2640 /* Don't export sysctls to unprivileged users */
2641 if (net->user_ns != &init_user_ns)
2642 tbl[0].procname = NULL;
2643 }
2644 tbl[0].extra1 = net;
2645
2646 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2647 if (net->ipv4.route_hdr == NULL)
2648 goto err_reg;
2649 return 0;
2650
2651 err_reg:
2652 if (tbl != ipv4_route_flush_table)
2653 kfree(tbl);
2654 err_dup:
2655 return -ENOMEM;
2656 }
2657
2658 static __net_exit void sysctl_route_net_exit(struct net *net)
2659 {
2660 struct ctl_table *tbl;
2661
2662 tbl = net->ipv4.route_hdr->ctl_table_arg;
2663 unregister_net_sysctl_table(net->ipv4.route_hdr);
2664 BUG_ON(tbl == ipv4_route_flush_table);
2665 kfree(tbl);
2666 }
2667
2668 static __net_initdata struct pernet_operations sysctl_route_ops = {
2669 .init = sysctl_route_net_init,
2670 .exit = sysctl_route_net_exit,
2671 };
2672 #endif
2673
2674 static __net_init int rt_genid_init(struct net *net)
2675 {
2676 atomic_set(&net->ipv4.rt_genid, 0);
2677 atomic_set(&net->fnhe_genid, 0);
2678 get_random_bytes(&net->ipv4.dev_addr_genid,
2679 sizeof(net->ipv4.dev_addr_genid));
2680 return 0;
2681 }
2682
2683 static __net_initdata struct pernet_operations rt_genid_ops = {
2684 .init = rt_genid_init,
2685 };
2686
2687 static int __net_init ipv4_inetpeer_init(struct net *net)
2688 {
2689 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2690
2691 if (!bp)
2692 return -ENOMEM;
2693 inet_peer_base_init(bp);
2694 net->ipv4.peers = bp;
2695 return 0;
2696 }
2697
2698 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2699 {
2700 struct inet_peer_base *bp = net->ipv4.peers;
2701
2702 net->ipv4.peers = NULL;
2703 inetpeer_invalidate_tree(bp);
2704 kfree(bp);
2705 }
2706
2707 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2708 .init = ipv4_inetpeer_init,
2709 .exit = ipv4_inetpeer_exit,
2710 };
2711
2712 #ifdef CONFIG_IP_ROUTE_CLASSID
2713 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2714 #endif /* CONFIG_IP_ROUTE_CLASSID */
2715
2716 int __init ip_rt_init(void)
2717 {
2718 int rc = 0;
2719
2720 #ifdef CONFIG_IP_ROUTE_CLASSID
2721 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2722 if (!ip_rt_acct)
2723 panic("IP: failed to allocate ip_rt_acct\n");
2724 #endif
2725
2726 ipv4_dst_ops.kmem_cachep =
2727 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2728 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2729
2730 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2731
2732 if (dst_entries_init(&ipv4_dst_ops) < 0)
2733 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2734
2735 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2736 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2737
2738 ipv4_dst_ops.gc_thresh = ~0;
2739 ip_rt_max_size = INT_MAX;
2740
2741 devinet_init();
2742 ip_fib_init();
2743
2744 if (ip_rt_proc_init())
2745 pr_err("Unable to create route proc files\n");
2746 #ifdef CONFIG_XFRM
2747 xfrm_init();
2748 xfrm4_init();
2749 #endif
2750 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2751
2752 #ifdef CONFIG_SYSCTL
2753 register_pernet_subsys(&sysctl_route_ops);
2754 #endif
2755 register_pernet_subsys(&rt_genid_ops);
2756 register_pernet_subsys(&ipv4_inetpeer_ops);
2757 return rc;
2758 }
2759
2760 #ifdef CONFIG_SYSCTL
2761 /*
2762 * We really need to sanitize the damn ipv4 init order, then all
2763 * this nonsense will go away.
2764 */
2765 void __init ip_static_sysctl_init(void)
2766 {
2767 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2768 }
2769 #endif
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