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173e7ea54c7016d43e81a269571049ca4b55199d
[deliverable/linux.git] / net / ipv4 / route.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65 #define pr_fmt(fmt) "IPv4: " fmt
66
67 #include <linux/module.h>
68 #include <asm/uaccess.h>
69 #include <linux/bitops.h>
70 #include <linux/types.h>
71 #include <linux/kernel.h>
72 #include <linux/mm.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
77 #include <linux/in.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/skbuff.h>
83 #include <linux/inetdevice.h>
84 #include <linux/igmp.h>
85 #include <linux/pkt_sched.h>
86 #include <linux/mroute.h>
87 #include <linux/netfilter_ipv4.h>
88 #include <linux/random.h>
89 #include <linux/rcupdate.h>
90 #include <linux/times.h>
91 #include <linux/slab.h>
92 #include <linux/jhash.h>
93 #include <net/dst.h>
94 #include <net/net_namespace.h>
95 #include <net/protocol.h>
96 #include <net/ip.h>
97 #include <net/route.h>
98 #include <net/inetpeer.h>
99 #include <net/sock.h>
100 #include <net/ip_fib.h>
101 #include <net/arp.h>
102 #include <net/tcp.h>
103 #include <net/icmp.h>
104 #include <net/xfrm.h>
105 #include <net/netevent.h>
106 #include <net/rtnetlink.h>
107 #ifdef CONFIG_SYSCTL
108 #include <linux/sysctl.h>
109 #include <linux/kmemleak.h>
110 #endif
111 #include <net/secure_seq.h>
112
113 #define RT_FL_TOS(oldflp4) \
114 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
115
116 #define RT_GC_TIMEOUT (300*HZ)
117
118 static int ip_rt_max_size;
119 static int ip_rt_redirect_number __read_mostly = 9;
120 static int ip_rt_redirect_load __read_mostly = HZ / 50;
121 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
122 static int ip_rt_error_cost __read_mostly = HZ;
123 static int ip_rt_error_burst __read_mostly = 5 * HZ;
124 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
125 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
126 static int ip_rt_min_advmss __read_mostly = 256;
127
128 /*
129 * Interface to generic destination cache.
130 */
131
132 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
133 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
134 static unsigned int ipv4_mtu(const struct dst_entry *dst);
135 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
136 static void ipv4_link_failure(struct sk_buff *skb);
137 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
138 struct sk_buff *skb, u32 mtu);
139 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
140 struct sk_buff *skb);
141 static void ipv4_dst_destroy(struct dst_entry *dst);
142
143 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
144 {
145 WARN_ON(1);
146 return NULL;
147 }
148
149 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
150 struct sk_buff *skb,
151 const void *daddr);
152
153 static struct dst_ops ipv4_dst_ops = {
154 .family = AF_INET,
155 .protocol = cpu_to_be16(ETH_P_IP),
156 .check = ipv4_dst_check,
157 .default_advmss = ipv4_default_advmss,
158 .mtu = ipv4_mtu,
159 .cow_metrics = ipv4_cow_metrics,
160 .destroy = ipv4_dst_destroy,
161 .negative_advice = ipv4_negative_advice,
162 .link_failure = ipv4_link_failure,
163 .update_pmtu = ip_rt_update_pmtu,
164 .redirect = ip_do_redirect,
165 .local_out = __ip_local_out,
166 .neigh_lookup = ipv4_neigh_lookup,
167 };
168
169 #define ECN_OR_COST(class) TC_PRIO_##class
170
171 const __u8 ip_tos2prio[16] = {
172 TC_PRIO_BESTEFFORT,
173 ECN_OR_COST(BESTEFFORT),
174 TC_PRIO_BESTEFFORT,
175 ECN_OR_COST(BESTEFFORT),
176 TC_PRIO_BULK,
177 ECN_OR_COST(BULK),
178 TC_PRIO_BULK,
179 ECN_OR_COST(BULK),
180 TC_PRIO_INTERACTIVE,
181 ECN_OR_COST(INTERACTIVE),
182 TC_PRIO_INTERACTIVE,
183 ECN_OR_COST(INTERACTIVE),
184 TC_PRIO_INTERACTIVE_BULK,
185 ECN_OR_COST(INTERACTIVE_BULK),
186 TC_PRIO_INTERACTIVE_BULK,
187 ECN_OR_COST(INTERACTIVE_BULK)
188 };
189 EXPORT_SYMBOL(ip_tos2prio);
190
191 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
192 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
193
194 #ifdef CONFIG_PROC_FS
195 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
196 {
197 if (*pos)
198 return NULL;
199 return SEQ_START_TOKEN;
200 }
201
202 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
203 {
204 ++*pos;
205 return NULL;
206 }
207
208 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
209 {
210 }
211
212 static int rt_cache_seq_show(struct seq_file *seq, void *v)
213 {
214 if (v == SEQ_START_TOKEN)
215 seq_printf(seq, "%-127s\n",
216 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
217 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
218 "HHUptod\tSpecDst");
219 return 0;
220 }
221
222 static const struct seq_operations rt_cache_seq_ops = {
223 .start = rt_cache_seq_start,
224 .next = rt_cache_seq_next,
225 .stop = rt_cache_seq_stop,
226 .show = rt_cache_seq_show,
227 };
228
229 static int rt_cache_seq_open(struct inode *inode, struct file *file)
230 {
231 return seq_open(file, &rt_cache_seq_ops);
232 }
233
234 static const struct file_operations rt_cache_seq_fops = {
235 .owner = THIS_MODULE,
236 .open = rt_cache_seq_open,
237 .read = seq_read,
238 .llseek = seq_lseek,
239 .release = seq_release,
240 };
241
242
243 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
244 {
245 int cpu;
246
247 if (*pos == 0)
248 return SEQ_START_TOKEN;
249
250 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
251 if (!cpu_possible(cpu))
252 continue;
253 *pos = cpu+1;
254 return &per_cpu(rt_cache_stat, cpu);
255 }
256 return NULL;
257 }
258
259 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
260 {
261 int cpu;
262
263 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
264 if (!cpu_possible(cpu))
265 continue;
266 *pos = cpu+1;
267 return &per_cpu(rt_cache_stat, cpu);
268 }
269 return NULL;
270
271 }
272
273 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
274 {
275
276 }
277
278 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
279 {
280 struct rt_cache_stat *st = v;
281
282 if (v == SEQ_START_TOKEN) {
283 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");
284 return 0;
285 }
286
287 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
288 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
289 dst_entries_get_slow(&ipv4_dst_ops),
290 0, /* st->in_hit */
291 st->in_slow_tot,
292 st->in_slow_mc,
293 st->in_no_route,
294 st->in_brd,
295 st->in_martian_dst,
296 st->in_martian_src,
297
298 0, /* st->out_hit */
299 st->out_slow_tot,
300 st->out_slow_mc,
301
302 0, /* st->gc_total */
303 0, /* st->gc_ignored */
304 0, /* st->gc_goal_miss */
305 0, /* st->gc_dst_overflow */
306 0, /* st->in_hlist_search */
307 0 /* st->out_hlist_search */
308 );
309 return 0;
310 }
311
312 static const struct seq_operations rt_cpu_seq_ops = {
313 .start = rt_cpu_seq_start,
314 .next = rt_cpu_seq_next,
315 .stop = rt_cpu_seq_stop,
316 .show = rt_cpu_seq_show,
317 };
318
319
320 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
321 {
322 return seq_open(file, &rt_cpu_seq_ops);
323 }
324
325 static const struct file_operations rt_cpu_seq_fops = {
326 .owner = THIS_MODULE,
327 .open = rt_cpu_seq_open,
328 .read = seq_read,
329 .llseek = seq_lseek,
330 .release = seq_release,
331 };
332
333 #ifdef CONFIG_IP_ROUTE_CLASSID
334 static int rt_acct_proc_show(struct seq_file *m, void *v)
335 {
336 struct ip_rt_acct *dst, *src;
337 unsigned int i, j;
338
339 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
340 if (!dst)
341 return -ENOMEM;
342
343 for_each_possible_cpu(i) {
344 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
345 for (j = 0; j < 256; j++) {
346 dst[j].o_bytes += src[j].o_bytes;
347 dst[j].o_packets += src[j].o_packets;
348 dst[j].i_bytes += src[j].i_bytes;
349 dst[j].i_packets += src[j].i_packets;
350 }
351 }
352
353 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
354 kfree(dst);
355 return 0;
356 }
357
358 static int rt_acct_proc_open(struct inode *inode, struct file *file)
359 {
360 return single_open(file, rt_acct_proc_show, NULL);
361 }
362
363 static const struct file_operations rt_acct_proc_fops = {
364 .owner = THIS_MODULE,
365 .open = rt_acct_proc_open,
366 .read = seq_read,
367 .llseek = seq_lseek,
368 .release = single_release,
369 };
370 #endif
371
372 static int __net_init ip_rt_do_proc_init(struct net *net)
373 {
374 struct proc_dir_entry *pde;
375
376 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
377 &rt_cache_seq_fops);
378 if (!pde)
379 goto err1;
380
381 pde = proc_create("rt_cache", S_IRUGO,
382 net->proc_net_stat, &rt_cpu_seq_fops);
383 if (!pde)
384 goto err2;
385
386 #ifdef CONFIG_IP_ROUTE_CLASSID
387 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
388 if (!pde)
389 goto err3;
390 #endif
391 return 0;
392
393 #ifdef CONFIG_IP_ROUTE_CLASSID
394 err3:
395 remove_proc_entry("rt_cache", net->proc_net_stat);
396 #endif
397 err2:
398 remove_proc_entry("rt_cache", net->proc_net);
399 err1:
400 return -ENOMEM;
401 }
402
403 static void __net_exit ip_rt_do_proc_exit(struct net *net)
404 {
405 remove_proc_entry("rt_cache", net->proc_net_stat);
406 remove_proc_entry("rt_cache", net->proc_net);
407 #ifdef CONFIG_IP_ROUTE_CLASSID
408 remove_proc_entry("rt_acct", net->proc_net);
409 #endif
410 }
411
412 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
413 .init = ip_rt_do_proc_init,
414 .exit = ip_rt_do_proc_exit,
415 };
416
417 static int __init ip_rt_proc_init(void)
418 {
419 return register_pernet_subsys(&ip_rt_proc_ops);
420 }
421
422 #else
423 static inline int ip_rt_proc_init(void)
424 {
425 return 0;
426 }
427 #endif /* CONFIG_PROC_FS */
428
429 static inline bool rt_is_expired(const struct rtable *rth)
430 {
431 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
432 }
433
434 void rt_cache_flush(struct net *net)
435 {
436 rt_genid_bump_ipv4(net);
437 }
438
439 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
440 struct sk_buff *skb,
441 const void *daddr)
442 {
443 struct net_device *dev = dst->dev;
444 const __be32 *pkey = daddr;
445 const struct rtable *rt;
446 struct neighbour *n;
447
448 rt = (const struct rtable *) dst;
449 if (rt->rt_gateway)
450 pkey = (const __be32 *) &rt->rt_gateway;
451 else if (skb)
452 pkey = &ip_hdr(skb)->daddr;
453
454 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
455 if (n)
456 return n;
457 return neigh_create(&arp_tbl, pkey, dev);
458 }
459
460 #define IP_IDENTS_SZ 2048u
461 struct ip_ident_bucket {
462 atomic_t id;
463 u32 stamp32;
464 };
465
466 static struct ip_ident_bucket *ip_idents __read_mostly;
467
468 /* In order to protect privacy, we add a perturbation to identifiers
469 * if one generator is seldom used. This makes hard for an attacker
470 * to infer how many packets were sent between two points in time.
471 */
472 u32 ip_idents_reserve(u32 hash, int segs)
473 {
474 struct ip_ident_bucket *bucket = ip_idents + hash % IP_IDENTS_SZ;
475 u32 old = ACCESS_ONCE(bucket->stamp32);
476 u32 now = (u32)jiffies;
477 u32 delta = 0;
478
479 if (old != now && cmpxchg(&bucket->stamp32, old, now) == old)
480 delta = prandom_u32_max(now - old);
481
482 return atomic_add_return(segs + delta, &bucket->id) - segs;
483 }
484 EXPORT_SYMBOL(ip_idents_reserve);
485
486 void __ip_select_ident(struct iphdr *iph, int segs)
487 {
488 static u32 ip_idents_hashrnd __read_mostly;
489 u32 hash, id;
490
491 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
492
493 hash = jhash_3words((__force u32)iph->daddr,
494 (__force u32)iph->saddr,
495 iph->protocol,
496 ip_idents_hashrnd);
497 id = ip_idents_reserve(hash, segs);
498 iph->id = htons(id);
499 }
500 EXPORT_SYMBOL(__ip_select_ident);
501
502 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
503 const struct iphdr *iph,
504 int oif, u8 tos,
505 u8 prot, u32 mark, int flow_flags)
506 {
507 if (sk) {
508 const struct inet_sock *inet = inet_sk(sk);
509
510 oif = sk->sk_bound_dev_if;
511 mark = sk->sk_mark;
512 tos = RT_CONN_FLAGS(sk);
513 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
514 }
515 flowi4_init_output(fl4, oif, mark, tos,
516 RT_SCOPE_UNIVERSE, prot,
517 flow_flags,
518 iph->daddr, iph->saddr, 0, 0);
519 }
520
521 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
522 const struct sock *sk)
523 {
524 const struct iphdr *iph = ip_hdr(skb);
525 int oif = skb->dev->ifindex;
526 u8 tos = RT_TOS(iph->tos);
527 u8 prot = iph->protocol;
528 u32 mark = skb->mark;
529
530 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
531 }
532
533 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
534 {
535 const struct inet_sock *inet = inet_sk(sk);
536 const struct ip_options_rcu *inet_opt;
537 __be32 daddr = inet->inet_daddr;
538
539 rcu_read_lock();
540 inet_opt = rcu_dereference(inet->inet_opt);
541 if (inet_opt && inet_opt->opt.srr)
542 daddr = inet_opt->opt.faddr;
543 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
544 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
545 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
546 inet_sk_flowi_flags(sk),
547 daddr, inet->inet_saddr, 0, 0);
548 rcu_read_unlock();
549 }
550
551 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
552 const struct sk_buff *skb)
553 {
554 if (skb)
555 build_skb_flow_key(fl4, skb, sk);
556 else
557 build_sk_flow_key(fl4, sk);
558 }
559
560 static inline void rt_free(struct rtable *rt)
561 {
562 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
563 }
564
565 static DEFINE_SPINLOCK(fnhe_lock);
566
567 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
568 {
569 struct rtable *rt;
570
571 rt = rcu_dereference(fnhe->fnhe_rth_input);
572 if (rt) {
573 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
574 rt_free(rt);
575 }
576 rt = rcu_dereference(fnhe->fnhe_rth_output);
577 if (rt) {
578 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
579 rt_free(rt);
580 }
581 }
582
583 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
584 {
585 struct fib_nh_exception *fnhe, *oldest;
586
587 oldest = rcu_dereference(hash->chain);
588 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
589 fnhe = rcu_dereference(fnhe->fnhe_next)) {
590 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
591 oldest = fnhe;
592 }
593 fnhe_flush_routes(oldest);
594 return oldest;
595 }
596
597 static inline u32 fnhe_hashfun(__be32 daddr)
598 {
599 u32 hval;
600
601 hval = (__force u32) daddr;
602 hval ^= (hval >> 11) ^ (hval >> 22);
603
604 return hval & (FNHE_HASH_SIZE - 1);
605 }
606
607 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
608 {
609 rt->rt_pmtu = fnhe->fnhe_pmtu;
610 rt->dst.expires = fnhe->fnhe_expires;
611
612 if (fnhe->fnhe_gw) {
613 rt->rt_flags |= RTCF_REDIRECTED;
614 rt->rt_gateway = fnhe->fnhe_gw;
615 rt->rt_uses_gateway = 1;
616 }
617 }
618
619 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
620 u32 pmtu, unsigned long expires)
621 {
622 struct fnhe_hash_bucket *hash;
623 struct fib_nh_exception *fnhe;
624 struct rtable *rt;
625 unsigned int i;
626 int depth;
627 u32 hval = fnhe_hashfun(daddr);
628
629 spin_lock_bh(&fnhe_lock);
630
631 hash = nh->nh_exceptions;
632 if (!hash) {
633 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
634 if (!hash)
635 goto out_unlock;
636 nh->nh_exceptions = hash;
637 }
638
639 hash += hval;
640
641 depth = 0;
642 for (fnhe = rcu_dereference(hash->chain); fnhe;
643 fnhe = rcu_dereference(fnhe->fnhe_next)) {
644 if (fnhe->fnhe_daddr == daddr)
645 break;
646 depth++;
647 }
648
649 if (fnhe) {
650 if (gw)
651 fnhe->fnhe_gw = gw;
652 if (pmtu) {
653 fnhe->fnhe_pmtu = pmtu;
654 fnhe->fnhe_expires = max(1UL, expires);
655 }
656 /* Update all cached dsts too */
657 rt = rcu_dereference(fnhe->fnhe_rth_input);
658 if (rt)
659 fill_route_from_fnhe(rt, fnhe);
660 rt = rcu_dereference(fnhe->fnhe_rth_output);
661 if (rt)
662 fill_route_from_fnhe(rt, fnhe);
663 } else {
664 if (depth > FNHE_RECLAIM_DEPTH)
665 fnhe = fnhe_oldest(hash);
666 else {
667 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
668 if (!fnhe)
669 goto out_unlock;
670
671 fnhe->fnhe_next = hash->chain;
672 rcu_assign_pointer(hash->chain, fnhe);
673 }
674 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
675 fnhe->fnhe_daddr = daddr;
676 fnhe->fnhe_gw = gw;
677 fnhe->fnhe_pmtu = pmtu;
678 fnhe->fnhe_expires = expires;
679
680 /* Exception created; mark the cached routes for the nexthop
681 * stale, so anyone caching it rechecks if this exception
682 * applies to them.
683 */
684 rt = rcu_dereference(nh->nh_rth_input);
685 if (rt)
686 rt->dst.obsolete = DST_OBSOLETE_KILL;
687
688 for_each_possible_cpu(i) {
689 struct rtable __rcu **prt;
690 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
691 rt = rcu_dereference(*prt);
692 if (rt)
693 rt->dst.obsolete = DST_OBSOLETE_KILL;
694 }
695 }
696
697 fnhe->fnhe_stamp = jiffies;
698
699 out_unlock:
700 spin_unlock_bh(&fnhe_lock);
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 if (!mark)
1004 mark = IP4_REPLY_MARK(net, skb->mark);
1005
1006 __build_flow_key(&fl4, NULL, iph, oif,
1007 RT_TOS(iph->tos), protocol, mark, flow_flags);
1008 rt = __ip_route_output_key(net, &fl4);
1009 if (!IS_ERR(rt)) {
1010 __ip_rt_update_pmtu(rt, &fl4, mtu);
1011 ip_rt_put(rt);
1012 }
1013 }
1014 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1015
1016 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1017 {
1018 const struct iphdr *iph = (const struct iphdr *) skb->data;
1019 struct flowi4 fl4;
1020 struct rtable *rt;
1021
1022 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1023
1024 if (!fl4.flowi4_mark)
1025 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1026
1027 rt = __ip_route_output_key(sock_net(sk), &fl4);
1028 if (!IS_ERR(rt)) {
1029 __ip_rt_update_pmtu(rt, &fl4, mtu);
1030 ip_rt_put(rt);
1031 }
1032 }
1033
1034 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1035 {
1036 const struct iphdr *iph = (const struct iphdr *) skb->data;
1037 struct flowi4 fl4;
1038 struct rtable *rt;
1039 struct dst_entry *odst = NULL;
1040 bool new = false;
1041
1042 bh_lock_sock(sk);
1043
1044 if (!ip_sk_accept_pmtu(sk))
1045 goto out;
1046
1047 odst = sk_dst_get(sk);
1048
1049 if (sock_owned_by_user(sk) || !odst) {
1050 __ipv4_sk_update_pmtu(skb, sk, mtu);
1051 goto out;
1052 }
1053
1054 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1055
1056 rt = (struct rtable *)odst;
1057 if (odst->obsolete && odst->ops->check(odst, 0) == NULL) {
1058 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1059 if (IS_ERR(rt))
1060 goto out;
1061
1062 new = true;
1063 }
1064
1065 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1066
1067 if (!dst_check(&rt->dst, 0)) {
1068 if (new)
1069 dst_release(&rt->dst);
1070
1071 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1072 if (IS_ERR(rt))
1073 goto out;
1074
1075 new = true;
1076 }
1077
1078 if (new)
1079 sk_dst_set(sk, &rt->dst);
1080
1081 out:
1082 bh_unlock_sock(sk);
1083 dst_release(odst);
1084 }
1085 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1086
1087 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1088 int oif, u32 mark, u8 protocol, int flow_flags)
1089 {
1090 const struct iphdr *iph = (const struct iphdr *) skb->data;
1091 struct flowi4 fl4;
1092 struct rtable *rt;
1093
1094 __build_flow_key(&fl4, NULL, iph, oif,
1095 RT_TOS(iph->tos), protocol, mark, flow_flags);
1096 rt = __ip_route_output_key(net, &fl4);
1097 if (!IS_ERR(rt)) {
1098 __ip_do_redirect(rt, skb, &fl4, false);
1099 ip_rt_put(rt);
1100 }
1101 }
1102 EXPORT_SYMBOL_GPL(ipv4_redirect);
1103
1104 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1105 {
1106 const struct iphdr *iph = (const struct iphdr *) skb->data;
1107 struct flowi4 fl4;
1108 struct rtable *rt;
1109
1110 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1111 rt = __ip_route_output_key(sock_net(sk), &fl4);
1112 if (!IS_ERR(rt)) {
1113 __ip_do_redirect(rt, skb, &fl4, false);
1114 ip_rt_put(rt);
1115 }
1116 }
1117 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1118
1119 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1120 {
1121 struct rtable *rt = (struct rtable *) dst;
1122
1123 /* All IPV4 dsts are created with ->obsolete set to the value
1124 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1125 * into this function always.
1126 *
1127 * When a PMTU/redirect information update invalidates a route,
1128 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1129 * DST_OBSOLETE_DEAD by dst_free().
1130 */
1131 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1132 return NULL;
1133 return dst;
1134 }
1135
1136 static void ipv4_link_failure(struct sk_buff *skb)
1137 {
1138 struct rtable *rt;
1139
1140 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1141
1142 rt = skb_rtable(skb);
1143 if (rt)
1144 dst_set_expires(&rt->dst, 0);
1145 }
1146
1147 static int ip_rt_bug(struct sock *sk, struct sk_buff *skb)
1148 {
1149 pr_debug("%s: %pI4 -> %pI4, %s\n",
1150 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1151 skb->dev ? skb->dev->name : "?");
1152 kfree_skb(skb);
1153 WARN_ON(1);
1154 return 0;
1155 }
1156
1157 /*
1158 We do not cache source address of outgoing interface,
1159 because it is used only by IP RR, TS and SRR options,
1160 so that it out of fast path.
1161
1162 BTW remember: "addr" is allowed to be not aligned
1163 in IP options!
1164 */
1165
1166 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1167 {
1168 __be32 src;
1169
1170 if (rt_is_output_route(rt))
1171 src = ip_hdr(skb)->saddr;
1172 else {
1173 struct fib_result res;
1174 struct flowi4 fl4;
1175 struct iphdr *iph;
1176
1177 iph = ip_hdr(skb);
1178
1179 memset(&fl4, 0, sizeof(fl4));
1180 fl4.daddr = iph->daddr;
1181 fl4.saddr = iph->saddr;
1182 fl4.flowi4_tos = RT_TOS(iph->tos);
1183 fl4.flowi4_oif = rt->dst.dev->ifindex;
1184 fl4.flowi4_iif = skb->dev->ifindex;
1185 fl4.flowi4_mark = skb->mark;
1186
1187 rcu_read_lock();
1188 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1189 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1190 else
1191 src = inet_select_addr(rt->dst.dev,
1192 rt_nexthop(rt, iph->daddr),
1193 RT_SCOPE_UNIVERSE);
1194 rcu_read_unlock();
1195 }
1196 memcpy(addr, &src, 4);
1197 }
1198
1199 #ifdef CONFIG_IP_ROUTE_CLASSID
1200 static void set_class_tag(struct rtable *rt, u32 tag)
1201 {
1202 if (!(rt->dst.tclassid & 0xFFFF))
1203 rt->dst.tclassid |= tag & 0xFFFF;
1204 if (!(rt->dst.tclassid & 0xFFFF0000))
1205 rt->dst.tclassid |= tag & 0xFFFF0000;
1206 }
1207 #endif
1208
1209 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1210 {
1211 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1212
1213 if (advmss == 0) {
1214 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1215 ip_rt_min_advmss);
1216 if (advmss > 65535 - 40)
1217 advmss = 65535 - 40;
1218 }
1219 return advmss;
1220 }
1221
1222 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1223 {
1224 const struct rtable *rt = (const struct rtable *) dst;
1225 unsigned int mtu = rt->rt_pmtu;
1226
1227 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1228 mtu = dst_metric_raw(dst, RTAX_MTU);
1229
1230 if (mtu)
1231 return mtu;
1232
1233 mtu = dst->dev->mtu;
1234
1235 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1236 if (rt->rt_uses_gateway && mtu > 576)
1237 mtu = 576;
1238 }
1239
1240 return min_t(unsigned int, mtu, IP_MAX_MTU);
1241 }
1242
1243 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1244 {
1245 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1246 struct fib_nh_exception *fnhe;
1247 u32 hval;
1248
1249 if (!hash)
1250 return NULL;
1251
1252 hval = fnhe_hashfun(daddr);
1253
1254 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1255 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1256 if (fnhe->fnhe_daddr == daddr)
1257 return fnhe;
1258 }
1259 return NULL;
1260 }
1261
1262 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1263 __be32 daddr)
1264 {
1265 bool ret = false;
1266
1267 spin_lock_bh(&fnhe_lock);
1268
1269 if (daddr == fnhe->fnhe_daddr) {
1270 struct rtable __rcu **porig;
1271 struct rtable *orig;
1272 int genid = fnhe_genid(dev_net(rt->dst.dev));
1273
1274 if (rt_is_input_route(rt))
1275 porig = &fnhe->fnhe_rth_input;
1276 else
1277 porig = &fnhe->fnhe_rth_output;
1278 orig = rcu_dereference(*porig);
1279
1280 if (fnhe->fnhe_genid != genid) {
1281 fnhe->fnhe_genid = genid;
1282 fnhe->fnhe_gw = 0;
1283 fnhe->fnhe_pmtu = 0;
1284 fnhe->fnhe_expires = 0;
1285 fnhe_flush_routes(fnhe);
1286 orig = NULL;
1287 }
1288 fill_route_from_fnhe(rt, fnhe);
1289 if (!rt->rt_gateway)
1290 rt->rt_gateway = daddr;
1291
1292 if (!(rt->dst.flags & DST_NOCACHE)) {
1293 rcu_assign_pointer(*porig, rt);
1294 if (orig)
1295 rt_free(orig);
1296 ret = true;
1297 }
1298
1299 fnhe->fnhe_stamp = jiffies;
1300 }
1301 spin_unlock_bh(&fnhe_lock);
1302
1303 return ret;
1304 }
1305
1306 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1307 {
1308 struct rtable *orig, *prev, **p;
1309 bool ret = true;
1310
1311 if (rt_is_input_route(rt)) {
1312 p = (struct rtable **)&nh->nh_rth_input;
1313 } else {
1314 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1315 }
1316 orig = *p;
1317
1318 prev = cmpxchg(p, orig, rt);
1319 if (prev == orig) {
1320 if (orig)
1321 rt_free(orig);
1322 } else
1323 ret = false;
1324
1325 return ret;
1326 }
1327
1328 static DEFINE_SPINLOCK(rt_uncached_lock);
1329 static LIST_HEAD(rt_uncached_list);
1330
1331 static void rt_add_uncached_list(struct rtable *rt)
1332 {
1333 spin_lock_bh(&rt_uncached_lock);
1334 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1335 spin_unlock_bh(&rt_uncached_lock);
1336 }
1337
1338 static void ipv4_dst_destroy(struct dst_entry *dst)
1339 {
1340 struct rtable *rt = (struct rtable *) dst;
1341
1342 if (!list_empty(&rt->rt_uncached)) {
1343 spin_lock_bh(&rt_uncached_lock);
1344 list_del(&rt->rt_uncached);
1345 spin_unlock_bh(&rt_uncached_lock);
1346 }
1347 }
1348
1349 void rt_flush_dev(struct net_device *dev)
1350 {
1351 if (!list_empty(&rt_uncached_list)) {
1352 struct net *net = dev_net(dev);
1353 struct rtable *rt;
1354
1355 spin_lock_bh(&rt_uncached_lock);
1356 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1357 if (rt->dst.dev != dev)
1358 continue;
1359 rt->dst.dev = net->loopback_dev;
1360 dev_hold(rt->dst.dev);
1361 dev_put(dev);
1362 }
1363 spin_unlock_bh(&rt_uncached_lock);
1364 }
1365 }
1366
1367 static bool rt_cache_valid(const struct rtable *rt)
1368 {
1369 return rt &&
1370 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1371 !rt_is_expired(rt);
1372 }
1373
1374 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1375 const struct fib_result *res,
1376 struct fib_nh_exception *fnhe,
1377 struct fib_info *fi, u16 type, u32 itag)
1378 {
1379 bool cached = false;
1380
1381 if (fi) {
1382 struct fib_nh *nh = &FIB_RES_NH(*res);
1383
1384 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1385 rt->rt_gateway = nh->nh_gw;
1386 rt->rt_uses_gateway = 1;
1387 }
1388 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1389 #ifdef CONFIG_IP_ROUTE_CLASSID
1390 rt->dst.tclassid = nh->nh_tclassid;
1391 #endif
1392 if (unlikely(fnhe))
1393 cached = rt_bind_exception(rt, fnhe, daddr);
1394 else if (!(rt->dst.flags & DST_NOCACHE))
1395 cached = rt_cache_route(nh, rt);
1396 if (unlikely(!cached)) {
1397 /* Routes we intend to cache in nexthop exception or
1398 * FIB nexthop have the DST_NOCACHE bit clear.
1399 * However, if we are unsuccessful at storing this
1400 * route into the cache we really need to set it.
1401 */
1402 rt->dst.flags |= DST_NOCACHE;
1403 if (!rt->rt_gateway)
1404 rt->rt_gateway = daddr;
1405 rt_add_uncached_list(rt);
1406 }
1407 } else
1408 rt_add_uncached_list(rt);
1409
1410 #ifdef CONFIG_IP_ROUTE_CLASSID
1411 #ifdef CONFIG_IP_MULTIPLE_TABLES
1412 set_class_tag(rt, res->tclassid);
1413 #endif
1414 set_class_tag(rt, itag);
1415 #endif
1416 }
1417
1418 static struct rtable *rt_dst_alloc(struct net_device *dev,
1419 bool nopolicy, bool noxfrm, bool will_cache)
1420 {
1421 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1422 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1423 (nopolicy ? DST_NOPOLICY : 0) |
1424 (noxfrm ? DST_NOXFRM : 0));
1425 }
1426
1427 /* called in rcu_read_lock() section */
1428 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1429 u8 tos, struct net_device *dev, int our)
1430 {
1431 struct rtable *rth;
1432 struct in_device *in_dev = __in_dev_get_rcu(dev);
1433 u32 itag = 0;
1434 int err;
1435
1436 /* Primary sanity checks. */
1437
1438 if (in_dev == NULL)
1439 return -EINVAL;
1440
1441 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1442 skb->protocol != htons(ETH_P_IP))
1443 goto e_inval;
1444
1445 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1446 if (ipv4_is_loopback(saddr))
1447 goto e_inval;
1448
1449 if (ipv4_is_zeronet(saddr)) {
1450 if (!ipv4_is_local_multicast(daddr))
1451 goto e_inval;
1452 } else {
1453 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1454 in_dev, &itag);
1455 if (err < 0)
1456 goto e_err;
1457 }
1458 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1459 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1460 if (!rth)
1461 goto e_nobufs;
1462
1463 #ifdef CONFIG_IP_ROUTE_CLASSID
1464 rth->dst.tclassid = itag;
1465 #endif
1466 rth->dst.output = ip_rt_bug;
1467
1468 rth->rt_genid = rt_genid_ipv4(dev_net(dev));
1469 rth->rt_flags = RTCF_MULTICAST;
1470 rth->rt_type = RTN_MULTICAST;
1471 rth->rt_is_input= 1;
1472 rth->rt_iif = 0;
1473 rth->rt_pmtu = 0;
1474 rth->rt_gateway = 0;
1475 rth->rt_uses_gateway = 0;
1476 INIT_LIST_HEAD(&rth->rt_uncached);
1477 if (our) {
1478 rth->dst.input= ip_local_deliver;
1479 rth->rt_flags |= RTCF_LOCAL;
1480 }
1481
1482 #ifdef CONFIG_IP_MROUTE
1483 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1484 rth->dst.input = ip_mr_input;
1485 #endif
1486 RT_CACHE_STAT_INC(in_slow_mc);
1487
1488 skb_dst_set(skb, &rth->dst);
1489 return 0;
1490
1491 e_nobufs:
1492 return -ENOBUFS;
1493 e_inval:
1494 return -EINVAL;
1495 e_err:
1496 return err;
1497 }
1498
1499
1500 static void ip_handle_martian_source(struct net_device *dev,
1501 struct in_device *in_dev,
1502 struct sk_buff *skb,
1503 __be32 daddr,
1504 __be32 saddr)
1505 {
1506 RT_CACHE_STAT_INC(in_martian_src);
1507 #ifdef CONFIG_IP_ROUTE_VERBOSE
1508 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1509 /*
1510 * RFC1812 recommendation, if source is martian,
1511 * the only hint is MAC header.
1512 */
1513 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1514 &daddr, &saddr, dev->name);
1515 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1516 print_hex_dump(KERN_WARNING, "ll header: ",
1517 DUMP_PREFIX_OFFSET, 16, 1,
1518 skb_mac_header(skb),
1519 dev->hard_header_len, true);
1520 }
1521 }
1522 #endif
1523 }
1524
1525 /* called in rcu_read_lock() section */
1526 static int __mkroute_input(struct sk_buff *skb,
1527 const struct fib_result *res,
1528 struct in_device *in_dev,
1529 __be32 daddr, __be32 saddr, u32 tos)
1530 {
1531 struct fib_nh_exception *fnhe;
1532 struct rtable *rth;
1533 int err;
1534 struct in_device *out_dev;
1535 unsigned int flags = 0;
1536 bool do_cache;
1537 u32 itag = 0;
1538
1539 /* get a working reference to the output device */
1540 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1541 if (out_dev == NULL) {
1542 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1543 return -EINVAL;
1544 }
1545
1546 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1547 in_dev->dev, in_dev, &itag);
1548 if (err < 0) {
1549 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1550 saddr);
1551
1552 goto cleanup;
1553 }
1554
1555 do_cache = res->fi && !itag;
1556 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1557 (IN_DEV_SHARED_MEDIA(out_dev) ||
1558 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) {
1559 flags |= RTCF_DOREDIRECT;
1560 do_cache = false;
1561 }
1562
1563 if (skb->protocol != htons(ETH_P_IP)) {
1564 /* Not IP (i.e. ARP). Do not create route, if it is
1565 * invalid for proxy arp. DNAT routes are always valid.
1566 *
1567 * Proxy arp feature have been extended to allow, ARP
1568 * replies back to the same interface, to support
1569 * Private VLAN switch technologies. See arp.c.
1570 */
1571 if (out_dev == in_dev &&
1572 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1573 err = -EINVAL;
1574 goto cleanup;
1575 }
1576 }
1577
1578 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1579 if (do_cache) {
1580 if (fnhe != NULL)
1581 rth = rcu_dereference(fnhe->fnhe_rth_input);
1582 else
1583 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1584
1585 if (rt_cache_valid(rth)) {
1586 skb_dst_set_noref(skb, &rth->dst);
1587 goto out;
1588 }
1589 }
1590
1591 rth = rt_dst_alloc(out_dev->dev,
1592 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1593 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1594 if (!rth) {
1595 err = -ENOBUFS;
1596 goto cleanup;
1597 }
1598
1599 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev));
1600 rth->rt_flags = flags;
1601 rth->rt_type = res->type;
1602 rth->rt_is_input = 1;
1603 rth->rt_iif = 0;
1604 rth->rt_pmtu = 0;
1605 rth->rt_gateway = 0;
1606 rth->rt_uses_gateway = 0;
1607 INIT_LIST_HEAD(&rth->rt_uncached);
1608 RT_CACHE_STAT_INC(in_slow_tot);
1609
1610 rth->dst.input = ip_forward;
1611 rth->dst.output = ip_output;
1612
1613 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1614 skb_dst_set(skb, &rth->dst);
1615 out:
1616 err = 0;
1617 cleanup:
1618 return err;
1619 }
1620
1621 static int ip_mkroute_input(struct sk_buff *skb,
1622 struct fib_result *res,
1623 const struct flowi4 *fl4,
1624 struct in_device *in_dev,
1625 __be32 daddr, __be32 saddr, u32 tos)
1626 {
1627 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1628 if (res->fi && res->fi->fib_nhs > 1)
1629 fib_select_multipath(res);
1630 #endif
1631
1632 /* create a routing cache entry */
1633 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1634 }
1635
1636 /*
1637 * NOTE. We drop all the packets that has local source
1638 * addresses, because every properly looped back packet
1639 * must have correct destination already attached by output routine.
1640 *
1641 * Such approach solves two big problems:
1642 * 1. Not simplex devices are handled properly.
1643 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1644 * called with rcu_read_lock()
1645 */
1646
1647 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1648 u8 tos, struct net_device *dev)
1649 {
1650 struct fib_result res;
1651 struct in_device *in_dev = __in_dev_get_rcu(dev);
1652 struct flowi4 fl4;
1653 unsigned int flags = 0;
1654 u32 itag = 0;
1655 struct rtable *rth;
1656 int err = -EINVAL;
1657 struct net *net = dev_net(dev);
1658 bool do_cache;
1659
1660 /* IP on this device is disabled. */
1661
1662 if (!in_dev)
1663 goto out;
1664
1665 /* Check for the most weird martians, which can be not detected
1666 by fib_lookup.
1667 */
1668
1669 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1670 goto martian_source;
1671
1672 res.fi = NULL;
1673 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1674 goto brd_input;
1675
1676 /* Accept zero addresses only to limited broadcast;
1677 * I even do not know to fix it or not. Waiting for complains :-)
1678 */
1679 if (ipv4_is_zeronet(saddr))
1680 goto martian_source;
1681
1682 if (ipv4_is_zeronet(daddr))
1683 goto martian_destination;
1684
1685 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1686 * and call it once if daddr or/and saddr are loopback addresses
1687 */
1688 if (ipv4_is_loopback(daddr)) {
1689 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1690 goto martian_destination;
1691 } else if (ipv4_is_loopback(saddr)) {
1692 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1693 goto martian_source;
1694 }
1695
1696 /*
1697 * Now we are ready to route packet.
1698 */
1699 fl4.flowi4_oif = 0;
1700 fl4.flowi4_iif = dev->ifindex;
1701 fl4.flowi4_mark = skb->mark;
1702 fl4.flowi4_tos = tos;
1703 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1704 fl4.daddr = daddr;
1705 fl4.saddr = saddr;
1706 err = fib_lookup(net, &fl4, &res);
1707 if (err != 0) {
1708 if (!IN_DEV_FORWARD(in_dev))
1709 err = -EHOSTUNREACH;
1710 goto no_route;
1711 }
1712
1713 if (res.type == RTN_BROADCAST)
1714 goto brd_input;
1715
1716 if (res.type == RTN_LOCAL) {
1717 err = fib_validate_source(skb, saddr, daddr, tos,
1718 0, dev, in_dev, &itag);
1719 if (err < 0)
1720 goto martian_source_keep_err;
1721 goto local_input;
1722 }
1723
1724 if (!IN_DEV_FORWARD(in_dev)) {
1725 err = -EHOSTUNREACH;
1726 goto no_route;
1727 }
1728 if (res.type != RTN_UNICAST)
1729 goto martian_destination;
1730
1731 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1732 out: return err;
1733
1734 brd_input:
1735 if (skb->protocol != htons(ETH_P_IP))
1736 goto e_inval;
1737
1738 if (!ipv4_is_zeronet(saddr)) {
1739 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1740 in_dev, &itag);
1741 if (err < 0)
1742 goto martian_source_keep_err;
1743 }
1744 flags |= RTCF_BROADCAST;
1745 res.type = RTN_BROADCAST;
1746 RT_CACHE_STAT_INC(in_brd);
1747
1748 local_input:
1749 do_cache = false;
1750 if (res.fi) {
1751 if (!itag) {
1752 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1753 if (rt_cache_valid(rth)) {
1754 skb_dst_set_noref(skb, &rth->dst);
1755 err = 0;
1756 goto out;
1757 }
1758 do_cache = true;
1759 }
1760 }
1761
1762 rth = rt_dst_alloc(net->loopback_dev,
1763 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1764 if (!rth)
1765 goto e_nobufs;
1766
1767 rth->dst.input= ip_local_deliver;
1768 rth->dst.output= ip_rt_bug;
1769 #ifdef CONFIG_IP_ROUTE_CLASSID
1770 rth->dst.tclassid = itag;
1771 #endif
1772
1773 rth->rt_genid = rt_genid_ipv4(net);
1774 rth->rt_flags = flags|RTCF_LOCAL;
1775 rth->rt_type = res.type;
1776 rth->rt_is_input = 1;
1777 rth->rt_iif = 0;
1778 rth->rt_pmtu = 0;
1779 rth->rt_gateway = 0;
1780 rth->rt_uses_gateway = 0;
1781 INIT_LIST_HEAD(&rth->rt_uncached);
1782 RT_CACHE_STAT_INC(in_slow_tot);
1783 if (res.type == RTN_UNREACHABLE) {
1784 rth->dst.input= ip_error;
1785 rth->dst.error= -err;
1786 rth->rt_flags &= ~RTCF_LOCAL;
1787 }
1788 if (do_cache) {
1789 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1790 rth->dst.flags |= DST_NOCACHE;
1791 rt_add_uncached_list(rth);
1792 }
1793 }
1794 skb_dst_set(skb, &rth->dst);
1795 err = 0;
1796 goto out;
1797
1798 no_route:
1799 RT_CACHE_STAT_INC(in_no_route);
1800 res.type = RTN_UNREACHABLE;
1801 goto local_input;
1802
1803 /*
1804 * Do not cache martian addresses: they should be logged (RFC1812)
1805 */
1806 martian_destination:
1807 RT_CACHE_STAT_INC(in_martian_dst);
1808 #ifdef CONFIG_IP_ROUTE_VERBOSE
1809 if (IN_DEV_LOG_MARTIANS(in_dev))
1810 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1811 &daddr, &saddr, dev->name);
1812 #endif
1813
1814 e_inval:
1815 err = -EINVAL;
1816 goto out;
1817
1818 e_nobufs:
1819 err = -ENOBUFS;
1820 goto out;
1821
1822 martian_source:
1823 err = -EINVAL;
1824 martian_source_keep_err:
1825 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1826 goto out;
1827 }
1828
1829 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1830 u8 tos, struct net_device *dev)
1831 {
1832 int res;
1833
1834 rcu_read_lock();
1835
1836 /* Multicast recognition logic is moved from route cache to here.
1837 The problem was that too many Ethernet cards have broken/missing
1838 hardware multicast filters :-( As result the host on multicasting
1839 network acquires a lot of useless route cache entries, sort of
1840 SDR messages from all the world. Now we try to get rid of them.
1841 Really, provided software IP multicast filter is organized
1842 reasonably (at least, hashed), it does not result in a slowdown
1843 comparing with route cache reject entries.
1844 Note, that multicast routers are not affected, because
1845 route cache entry is created eventually.
1846 */
1847 if (ipv4_is_multicast(daddr)) {
1848 struct in_device *in_dev = __in_dev_get_rcu(dev);
1849
1850 if (in_dev) {
1851 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1852 ip_hdr(skb)->protocol);
1853 if (our
1854 #ifdef CONFIG_IP_MROUTE
1855 ||
1856 (!ipv4_is_local_multicast(daddr) &&
1857 IN_DEV_MFORWARD(in_dev))
1858 #endif
1859 ) {
1860 int res = ip_route_input_mc(skb, daddr, saddr,
1861 tos, dev, our);
1862 rcu_read_unlock();
1863 return res;
1864 }
1865 }
1866 rcu_read_unlock();
1867 return -EINVAL;
1868 }
1869 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1870 rcu_read_unlock();
1871 return res;
1872 }
1873 EXPORT_SYMBOL(ip_route_input_noref);
1874
1875 /* called with rcu_read_lock() */
1876 static struct rtable *__mkroute_output(const struct fib_result *res,
1877 const struct flowi4 *fl4, int orig_oif,
1878 struct net_device *dev_out,
1879 unsigned int flags)
1880 {
1881 struct fib_info *fi = res->fi;
1882 struct fib_nh_exception *fnhe;
1883 struct in_device *in_dev;
1884 u16 type = res->type;
1885 struct rtable *rth;
1886 bool do_cache;
1887
1888 in_dev = __in_dev_get_rcu(dev_out);
1889 if (!in_dev)
1890 return ERR_PTR(-EINVAL);
1891
1892 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1893 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1894 return ERR_PTR(-EINVAL);
1895
1896 if (ipv4_is_lbcast(fl4->daddr))
1897 type = RTN_BROADCAST;
1898 else if (ipv4_is_multicast(fl4->daddr))
1899 type = RTN_MULTICAST;
1900 else if (ipv4_is_zeronet(fl4->daddr))
1901 return ERR_PTR(-EINVAL);
1902
1903 if (dev_out->flags & IFF_LOOPBACK)
1904 flags |= RTCF_LOCAL;
1905
1906 do_cache = true;
1907 if (type == RTN_BROADCAST) {
1908 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1909 fi = NULL;
1910 } else if (type == RTN_MULTICAST) {
1911 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1912 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1913 fl4->flowi4_proto))
1914 flags &= ~RTCF_LOCAL;
1915 else
1916 do_cache = false;
1917 /* If multicast route do not exist use
1918 * default one, but do not gateway in this case.
1919 * Yes, it is hack.
1920 */
1921 if (fi && res->prefixlen < 4)
1922 fi = NULL;
1923 }
1924
1925 fnhe = NULL;
1926 do_cache &= fi != NULL;
1927 if (do_cache) {
1928 struct rtable __rcu **prth;
1929 struct fib_nh *nh = &FIB_RES_NH(*res);
1930
1931 fnhe = find_exception(nh, fl4->daddr);
1932 if (fnhe)
1933 prth = &fnhe->fnhe_rth_output;
1934 else {
1935 if (unlikely(fl4->flowi4_flags &
1936 FLOWI_FLAG_KNOWN_NH &&
1937 !(nh->nh_gw &&
1938 nh->nh_scope == RT_SCOPE_LINK))) {
1939 do_cache = false;
1940 goto add;
1941 }
1942 prth = __this_cpu_ptr(nh->nh_pcpu_rth_output);
1943 }
1944 rth = rcu_dereference(*prth);
1945 if (rt_cache_valid(rth)) {
1946 dst_hold(&rth->dst);
1947 return rth;
1948 }
1949 }
1950
1951 add:
1952 rth = rt_dst_alloc(dev_out,
1953 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1954 IN_DEV_CONF_GET(in_dev, NOXFRM),
1955 do_cache);
1956 if (!rth)
1957 return ERR_PTR(-ENOBUFS);
1958
1959 rth->dst.output = ip_output;
1960
1961 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out));
1962 rth->rt_flags = flags;
1963 rth->rt_type = type;
1964 rth->rt_is_input = 0;
1965 rth->rt_iif = orig_oif ? : 0;
1966 rth->rt_pmtu = 0;
1967 rth->rt_gateway = 0;
1968 rth->rt_uses_gateway = 0;
1969 INIT_LIST_HEAD(&rth->rt_uncached);
1970
1971 RT_CACHE_STAT_INC(out_slow_tot);
1972
1973 if (flags & RTCF_LOCAL)
1974 rth->dst.input = ip_local_deliver;
1975 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1976 if (flags & RTCF_LOCAL &&
1977 !(dev_out->flags & IFF_LOOPBACK)) {
1978 rth->dst.output = ip_mc_output;
1979 RT_CACHE_STAT_INC(out_slow_mc);
1980 }
1981 #ifdef CONFIG_IP_MROUTE
1982 if (type == RTN_MULTICAST) {
1983 if (IN_DEV_MFORWARD(in_dev) &&
1984 !ipv4_is_local_multicast(fl4->daddr)) {
1985 rth->dst.input = ip_mr_input;
1986 rth->dst.output = ip_mc_output;
1987 }
1988 }
1989 #endif
1990 }
1991
1992 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1993
1994 return rth;
1995 }
1996
1997 /*
1998 * Major route resolver routine.
1999 */
2000
2001 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
2002 {
2003 struct net_device *dev_out = NULL;
2004 __u8 tos = RT_FL_TOS(fl4);
2005 unsigned int flags = 0;
2006 struct fib_result res;
2007 struct rtable *rth;
2008 int orig_oif;
2009
2010 res.tclassid = 0;
2011 res.fi = NULL;
2012 res.table = NULL;
2013
2014 orig_oif = fl4->flowi4_oif;
2015
2016 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2017 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2018 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2019 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2020
2021 rcu_read_lock();
2022 if (fl4->saddr) {
2023 rth = ERR_PTR(-EINVAL);
2024 if (ipv4_is_multicast(fl4->saddr) ||
2025 ipv4_is_lbcast(fl4->saddr) ||
2026 ipv4_is_zeronet(fl4->saddr))
2027 goto out;
2028
2029 /* I removed check for oif == dev_out->oif here.
2030 It was wrong for two reasons:
2031 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2032 is assigned to multiple interfaces.
2033 2. Moreover, we are allowed to send packets with saddr
2034 of another iface. --ANK
2035 */
2036
2037 if (fl4->flowi4_oif == 0 &&
2038 (ipv4_is_multicast(fl4->daddr) ||
2039 ipv4_is_lbcast(fl4->daddr))) {
2040 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2041 dev_out = __ip_dev_find(net, fl4->saddr, false);
2042 if (dev_out == NULL)
2043 goto out;
2044
2045 /* Special hack: user can direct multicasts
2046 and limited broadcast via necessary interface
2047 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2048 This hack is not just for fun, it allows
2049 vic,vat and friends to work.
2050 They bind socket to loopback, set ttl to zero
2051 and expect that it will work.
2052 From the viewpoint of routing cache they are broken,
2053 because we are not allowed to build multicast path
2054 with loopback source addr (look, routing cache
2055 cannot know, that ttl is zero, so that packet
2056 will not leave this host and route is valid).
2057 Luckily, this hack is good workaround.
2058 */
2059
2060 fl4->flowi4_oif = dev_out->ifindex;
2061 goto make_route;
2062 }
2063
2064 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2065 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2066 if (!__ip_dev_find(net, fl4->saddr, false))
2067 goto out;
2068 }
2069 }
2070
2071
2072 if (fl4->flowi4_oif) {
2073 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2074 rth = ERR_PTR(-ENODEV);
2075 if (dev_out == NULL)
2076 goto out;
2077
2078 /* RACE: Check return value of inet_select_addr instead. */
2079 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2080 rth = ERR_PTR(-ENETUNREACH);
2081 goto out;
2082 }
2083 if (ipv4_is_local_multicast(fl4->daddr) ||
2084 ipv4_is_lbcast(fl4->daddr)) {
2085 if (!fl4->saddr)
2086 fl4->saddr = inet_select_addr(dev_out, 0,
2087 RT_SCOPE_LINK);
2088 goto make_route;
2089 }
2090 if (!fl4->saddr) {
2091 if (ipv4_is_multicast(fl4->daddr))
2092 fl4->saddr = inet_select_addr(dev_out, 0,
2093 fl4->flowi4_scope);
2094 else if (!fl4->daddr)
2095 fl4->saddr = inet_select_addr(dev_out, 0,
2096 RT_SCOPE_HOST);
2097 }
2098 }
2099
2100 if (!fl4->daddr) {
2101 fl4->daddr = fl4->saddr;
2102 if (!fl4->daddr)
2103 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2104 dev_out = net->loopback_dev;
2105 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2106 res.type = RTN_LOCAL;
2107 flags |= RTCF_LOCAL;
2108 goto make_route;
2109 }
2110
2111 if (fib_lookup(net, fl4, &res)) {
2112 res.fi = NULL;
2113 res.table = NULL;
2114 if (fl4->flowi4_oif) {
2115 /* Apparently, routing tables are wrong. Assume,
2116 that the destination is on link.
2117
2118 WHY? DW.
2119 Because we are allowed to send to iface
2120 even if it has NO routes and NO assigned
2121 addresses. When oif is specified, routing
2122 tables are looked up with only one purpose:
2123 to catch if destination is gatewayed, rather than
2124 direct. Moreover, if MSG_DONTROUTE is set,
2125 we send packet, ignoring both routing tables
2126 and ifaddr state. --ANK
2127
2128
2129 We could make it even if oif is unknown,
2130 likely IPv6, but we do not.
2131 */
2132
2133 if (fl4->saddr == 0)
2134 fl4->saddr = inet_select_addr(dev_out, 0,
2135 RT_SCOPE_LINK);
2136 res.type = RTN_UNICAST;
2137 goto make_route;
2138 }
2139 rth = ERR_PTR(-ENETUNREACH);
2140 goto out;
2141 }
2142
2143 if (res.type == RTN_LOCAL) {
2144 if (!fl4->saddr) {
2145 if (res.fi->fib_prefsrc)
2146 fl4->saddr = res.fi->fib_prefsrc;
2147 else
2148 fl4->saddr = fl4->daddr;
2149 }
2150 dev_out = net->loopback_dev;
2151 fl4->flowi4_oif = dev_out->ifindex;
2152 flags |= RTCF_LOCAL;
2153 goto make_route;
2154 }
2155
2156 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2157 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2158 fib_select_multipath(&res);
2159 else
2160 #endif
2161 if (!res.prefixlen &&
2162 res.table->tb_num_default > 1 &&
2163 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2164 fib_select_default(&res);
2165
2166 if (!fl4->saddr)
2167 fl4->saddr = FIB_RES_PREFSRC(net, res);
2168
2169 dev_out = FIB_RES_DEV(res);
2170 fl4->flowi4_oif = dev_out->ifindex;
2171
2172
2173 make_route:
2174 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2175
2176 out:
2177 rcu_read_unlock();
2178 return rth;
2179 }
2180 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2181
2182 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2183 {
2184 return NULL;
2185 }
2186
2187 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2188 {
2189 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2190
2191 return mtu ? : dst->dev->mtu;
2192 }
2193
2194 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2195 struct sk_buff *skb, u32 mtu)
2196 {
2197 }
2198
2199 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2200 struct sk_buff *skb)
2201 {
2202 }
2203
2204 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2205 unsigned long old)
2206 {
2207 return NULL;
2208 }
2209
2210 static struct dst_ops ipv4_dst_blackhole_ops = {
2211 .family = AF_INET,
2212 .protocol = cpu_to_be16(ETH_P_IP),
2213 .check = ipv4_blackhole_dst_check,
2214 .mtu = ipv4_blackhole_mtu,
2215 .default_advmss = ipv4_default_advmss,
2216 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2217 .redirect = ipv4_rt_blackhole_redirect,
2218 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2219 .neigh_lookup = ipv4_neigh_lookup,
2220 };
2221
2222 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2223 {
2224 struct rtable *ort = (struct rtable *) dst_orig;
2225 struct rtable *rt;
2226
2227 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2228 if (rt) {
2229 struct dst_entry *new = &rt->dst;
2230
2231 new->__use = 1;
2232 new->input = dst_discard;
2233 new->output = dst_discard_sk;
2234
2235 new->dev = ort->dst.dev;
2236 if (new->dev)
2237 dev_hold(new->dev);
2238
2239 rt->rt_is_input = ort->rt_is_input;
2240 rt->rt_iif = ort->rt_iif;
2241 rt->rt_pmtu = ort->rt_pmtu;
2242
2243 rt->rt_genid = rt_genid_ipv4(net);
2244 rt->rt_flags = ort->rt_flags;
2245 rt->rt_type = ort->rt_type;
2246 rt->rt_gateway = ort->rt_gateway;
2247 rt->rt_uses_gateway = ort->rt_uses_gateway;
2248
2249 INIT_LIST_HEAD(&rt->rt_uncached);
2250
2251 dst_free(new);
2252 }
2253
2254 dst_release(dst_orig);
2255
2256 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2257 }
2258
2259 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2260 struct sock *sk)
2261 {
2262 struct rtable *rt = __ip_route_output_key(net, flp4);
2263
2264 if (IS_ERR(rt))
2265 return rt;
2266
2267 if (flp4->flowi4_proto)
2268 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2269 flowi4_to_flowi(flp4),
2270 sk, 0);
2271
2272 return rt;
2273 }
2274 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2275
2276 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2277 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2278 u32 seq, int event, int nowait, unsigned int flags)
2279 {
2280 struct rtable *rt = skb_rtable(skb);
2281 struct rtmsg *r;
2282 struct nlmsghdr *nlh;
2283 unsigned long expires = 0;
2284 u32 error;
2285 u32 metrics[RTAX_MAX];
2286
2287 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2288 if (nlh == NULL)
2289 return -EMSGSIZE;
2290
2291 r = nlmsg_data(nlh);
2292 r->rtm_family = AF_INET;
2293 r->rtm_dst_len = 32;
2294 r->rtm_src_len = 0;
2295 r->rtm_tos = fl4->flowi4_tos;
2296 r->rtm_table = RT_TABLE_MAIN;
2297 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2298 goto nla_put_failure;
2299 r->rtm_type = rt->rt_type;
2300 r->rtm_scope = RT_SCOPE_UNIVERSE;
2301 r->rtm_protocol = RTPROT_UNSPEC;
2302 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2303 if (rt->rt_flags & RTCF_NOTIFY)
2304 r->rtm_flags |= RTM_F_NOTIFY;
2305
2306 if (nla_put_be32(skb, RTA_DST, dst))
2307 goto nla_put_failure;
2308 if (src) {
2309 r->rtm_src_len = 32;
2310 if (nla_put_be32(skb, RTA_SRC, src))
2311 goto nla_put_failure;
2312 }
2313 if (rt->dst.dev &&
2314 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2315 goto nla_put_failure;
2316 #ifdef CONFIG_IP_ROUTE_CLASSID
2317 if (rt->dst.tclassid &&
2318 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2319 goto nla_put_failure;
2320 #endif
2321 if (!rt_is_input_route(rt) &&
2322 fl4->saddr != src) {
2323 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2324 goto nla_put_failure;
2325 }
2326 if (rt->rt_uses_gateway &&
2327 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2328 goto nla_put_failure;
2329
2330 expires = rt->dst.expires;
2331 if (expires) {
2332 unsigned long now = jiffies;
2333
2334 if (time_before(now, expires))
2335 expires -= now;
2336 else
2337 expires = 0;
2338 }
2339
2340 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2341 if (rt->rt_pmtu && expires)
2342 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2343 if (rtnetlink_put_metrics(skb, metrics) < 0)
2344 goto nla_put_failure;
2345
2346 if (fl4->flowi4_mark &&
2347 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2348 goto nla_put_failure;
2349
2350 error = rt->dst.error;
2351
2352 if (rt_is_input_route(rt)) {
2353 #ifdef CONFIG_IP_MROUTE
2354 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2355 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2356 int err = ipmr_get_route(net, skb,
2357 fl4->saddr, fl4->daddr,
2358 r, nowait);
2359 if (err <= 0) {
2360 if (!nowait) {
2361 if (err == 0)
2362 return 0;
2363 goto nla_put_failure;
2364 } else {
2365 if (err == -EMSGSIZE)
2366 goto nla_put_failure;
2367 error = err;
2368 }
2369 }
2370 } else
2371 #endif
2372 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2373 goto nla_put_failure;
2374 }
2375
2376 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2377 goto nla_put_failure;
2378
2379 return nlmsg_end(skb, nlh);
2380
2381 nla_put_failure:
2382 nlmsg_cancel(skb, nlh);
2383 return -EMSGSIZE;
2384 }
2385
2386 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2387 {
2388 struct net *net = sock_net(in_skb->sk);
2389 struct rtmsg *rtm;
2390 struct nlattr *tb[RTA_MAX+1];
2391 struct rtable *rt = NULL;
2392 struct flowi4 fl4;
2393 __be32 dst = 0;
2394 __be32 src = 0;
2395 u32 iif;
2396 int err;
2397 int mark;
2398 struct sk_buff *skb;
2399
2400 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2401 if (err < 0)
2402 goto errout;
2403
2404 rtm = nlmsg_data(nlh);
2405
2406 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2407 if (skb == NULL) {
2408 err = -ENOBUFS;
2409 goto errout;
2410 }
2411
2412 /* Reserve room for dummy headers, this skb can pass
2413 through good chunk of routing engine.
2414 */
2415 skb_reset_mac_header(skb);
2416 skb_reset_network_header(skb);
2417
2418 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2419 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2420 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2421
2422 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2423 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2424 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2425 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2426
2427 memset(&fl4, 0, sizeof(fl4));
2428 fl4.daddr = dst;
2429 fl4.saddr = src;
2430 fl4.flowi4_tos = rtm->rtm_tos;
2431 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2432 fl4.flowi4_mark = mark;
2433
2434 if (iif) {
2435 struct net_device *dev;
2436
2437 dev = __dev_get_by_index(net, iif);
2438 if (dev == NULL) {
2439 err = -ENODEV;
2440 goto errout_free;
2441 }
2442
2443 skb->protocol = htons(ETH_P_IP);
2444 skb->dev = dev;
2445 skb->mark = mark;
2446 local_bh_disable();
2447 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2448 local_bh_enable();
2449
2450 rt = skb_rtable(skb);
2451 if (err == 0 && rt->dst.error)
2452 err = -rt->dst.error;
2453 } else {
2454 rt = ip_route_output_key(net, &fl4);
2455
2456 err = 0;
2457 if (IS_ERR(rt))
2458 err = PTR_ERR(rt);
2459 }
2460
2461 if (err)
2462 goto errout_free;
2463
2464 skb_dst_set(skb, &rt->dst);
2465 if (rtm->rtm_flags & RTM_F_NOTIFY)
2466 rt->rt_flags |= RTCF_NOTIFY;
2467
2468 err = rt_fill_info(net, dst, src, &fl4, skb,
2469 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2470 RTM_NEWROUTE, 0, 0);
2471 if (err <= 0)
2472 goto errout_free;
2473
2474 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2475 errout:
2476 return err;
2477
2478 errout_free:
2479 kfree_skb(skb);
2480 goto errout;
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 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2721 if (!ip_idents)
2722 panic("IP: failed to allocate ip_idents\n");
2723
2724 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2725
2726 #ifdef CONFIG_IP_ROUTE_CLASSID
2727 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2728 if (!ip_rt_acct)
2729 panic("IP: failed to allocate ip_rt_acct\n");
2730 #endif
2731
2732 ipv4_dst_ops.kmem_cachep =
2733 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2734 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2735
2736 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2737
2738 if (dst_entries_init(&ipv4_dst_ops) < 0)
2739 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2740
2741 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2742 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2743
2744 ipv4_dst_ops.gc_thresh = ~0;
2745 ip_rt_max_size = INT_MAX;
2746
2747 devinet_init();
2748 ip_fib_init();
2749
2750 if (ip_rt_proc_init())
2751 pr_err("Unable to create route proc files\n");
2752 #ifdef CONFIG_XFRM
2753 xfrm_init();
2754 xfrm4_init();
2755 #endif
2756 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2757
2758 #ifdef CONFIG_SYSCTL
2759 register_pernet_subsys(&sysctl_route_ops);
2760 #endif
2761 register_pernet_subsys(&rt_genid_ops);
2762 register_pernet_subsys(&ipv4_inetpeer_ops);
2763 return rc;
2764 }
2765
2766 #ifdef CONFIG_SYSCTL
2767 /*
2768 * We really need to sanitize the damn ipv4 init order, then all
2769 * this nonsense will go away.
2770 */
2771 void __init ip_static_sysctl_init(void)
2772 {
2773 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2774 }
2775 #endif
Linux kernel - Deliverables
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