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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide
[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 atomic_t *ip_idents __read_mostly;
461 EXPORT_SYMBOL(ip_idents);
462
463 void __ip_select_ident(struct iphdr *iph, int segs)
464 {
465 static u32 ip_idents_hashrnd __read_mostly;
466 u32 hash, id;
467
468 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
469
470 hash = jhash_1word((__force u32)iph->daddr, ip_idents_hashrnd);
471 id = ip_idents_reserve(hash, segs);
472 iph->id = htons(id);
473 }
474 EXPORT_SYMBOL(__ip_select_ident);
475
476 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
477 const struct iphdr *iph,
478 int oif, u8 tos,
479 u8 prot, u32 mark, int flow_flags)
480 {
481 if (sk) {
482 const struct inet_sock *inet = inet_sk(sk);
483
484 oif = sk->sk_bound_dev_if;
485 mark = sk->sk_mark;
486 tos = RT_CONN_FLAGS(sk);
487 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
488 }
489 flowi4_init_output(fl4, oif, mark, tos,
490 RT_SCOPE_UNIVERSE, prot,
491 flow_flags,
492 iph->daddr, iph->saddr, 0, 0);
493 }
494
495 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
496 const struct sock *sk)
497 {
498 const struct iphdr *iph = ip_hdr(skb);
499 int oif = skb->dev->ifindex;
500 u8 tos = RT_TOS(iph->tos);
501 u8 prot = iph->protocol;
502 u32 mark = skb->mark;
503
504 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
505 }
506
507 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
508 {
509 const struct inet_sock *inet = inet_sk(sk);
510 const struct ip_options_rcu *inet_opt;
511 __be32 daddr = inet->inet_daddr;
512
513 rcu_read_lock();
514 inet_opt = rcu_dereference(inet->inet_opt);
515 if (inet_opt && inet_opt->opt.srr)
516 daddr = inet_opt->opt.faddr;
517 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
518 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
519 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
520 inet_sk_flowi_flags(sk),
521 daddr, inet->inet_saddr, 0, 0);
522 rcu_read_unlock();
523 }
524
525 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
526 const struct sk_buff *skb)
527 {
528 if (skb)
529 build_skb_flow_key(fl4, skb, sk);
530 else
531 build_sk_flow_key(fl4, sk);
532 }
533
534 static inline void rt_free(struct rtable *rt)
535 {
536 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
537 }
538
539 static DEFINE_SPINLOCK(fnhe_lock);
540
541 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
542 {
543 struct rtable *rt;
544
545 rt = rcu_dereference(fnhe->fnhe_rth_input);
546 if (rt) {
547 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
548 rt_free(rt);
549 }
550 rt = rcu_dereference(fnhe->fnhe_rth_output);
551 if (rt) {
552 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
553 rt_free(rt);
554 }
555 }
556
557 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
558 {
559 struct fib_nh_exception *fnhe, *oldest;
560
561 oldest = rcu_dereference(hash->chain);
562 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
563 fnhe = rcu_dereference(fnhe->fnhe_next)) {
564 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
565 oldest = fnhe;
566 }
567 fnhe_flush_routes(oldest);
568 return oldest;
569 }
570
571 static inline u32 fnhe_hashfun(__be32 daddr)
572 {
573 u32 hval;
574
575 hval = (__force u32) daddr;
576 hval ^= (hval >> 11) ^ (hval >> 22);
577
578 return hval & (FNHE_HASH_SIZE - 1);
579 }
580
581 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
582 {
583 rt->rt_pmtu = fnhe->fnhe_pmtu;
584 rt->dst.expires = fnhe->fnhe_expires;
585
586 if (fnhe->fnhe_gw) {
587 rt->rt_flags |= RTCF_REDIRECTED;
588 rt->rt_gateway = fnhe->fnhe_gw;
589 rt->rt_uses_gateway = 1;
590 }
591 }
592
593 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
594 u32 pmtu, unsigned long expires)
595 {
596 struct fnhe_hash_bucket *hash;
597 struct fib_nh_exception *fnhe;
598 struct rtable *rt;
599 unsigned int i;
600 int depth;
601 u32 hval = fnhe_hashfun(daddr);
602
603 spin_lock_bh(&fnhe_lock);
604
605 hash = nh->nh_exceptions;
606 if (!hash) {
607 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
608 if (!hash)
609 goto out_unlock;
610 nh->nh_exceptions = hash;
611 }
612
613 hash += hval;
614
615 depth = 0;
616 for (fnhe = rcu_dereference(hash->chain); fnhe;
617 fnhe = rcu_dereference(fnhe->fnhe_next)) {
618 if (fnhe->fnhe_daddr == daddr)
619 break;
620 depth++;
621 }
622
623 if (fnhe) {
624 if (gw)
625 fnhe->fnhe_gw = gw;
626 if (pmtu) {
627 fnhe->fnhe_pmtu = pmtu;
628 fnhe->fnhe_expires = max(1UL, expires);
629 }
630 /* Update all cached dsts too */
631 rt = rcu_dereference(fnhe->fnhe_rth_input);
632 if (rt)
633 fill_route_from_fnhe(rt, fnhe);
634 rt = rcu_dereference(fnhe->fnhe_rth_output);
635 if (rt)
636 fill_route_from_fnhe(rt, fnhe);
637 } else {
638 if (depth > FNHE_RECLAIM_DEPTH)
639 fnhe = fnhe_oldest(hash);
640 else {
641 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
642 if (!fnhe)
643 goto out_unlock;
644
645 fnhe->fnhe_next = hash->chain;
646 rcu_assign_pointer(hash->chain, fnhe);
647 }
648 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
649 fnhe->fnhe_daddr = daddr;
650 fnhe->fnhe_gw = gw;
651 fnhe->fnhe_pmtu = pmtu;
652 fnhe->fnhe_expires = expires;
653
654 /* Exception created; mark the cached routes for the nexthop
655 * stale, so anyone caching it rechecks if this exception
656 * applies to them.
657 */
658 rt = rcu_dereference(nh->nh_rth_input);
659 if (rt)
660 rt->dst.obsolete = DST_OBSOLETE_KILL;
661
662 for_each_possible_cpu(i) {
663 struct rtable __rcu **prt;
664 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
665 rt = rcu_dereference(*prt);
666 if (rt)
667 rt->dst.obsolete = DST_OBSOLETE_KILL;
668 }
669 }
670
671 fnhe->fnhe_stamp = jiffies;
672
673 out_unlock:
674 spin_unlock_bh(&fnhe_lock);
675 }
676
677 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
678 bool kill_route)
679 {
680 __be32 new_gw = icmp_hdr(skb)->un.gateway;
681 __be32 old_gw = ip_hdr(skb)->saddr;
682 struct net_device *dev = skb->dev;
683 struct in_device *in_dev;
684 struct fib_result res;
685 struct neighbour *n;
686 struct net *net;
687
688 switch (icmp_hdr(skb)->code & 7) {
689 case ICMP_REDIR_NET:
690 case ICMP_REDIR_NETTOS:
691 case ICMP_REDIR_HOST:
692 case ICMP_REDIR_HOSTTOS:
693 break;
694
695 default:
696 return;
697 }
698
699 if (rt->rt_gateway != old_gw)
700 return;
701
702 in_dev = __in_dev_get_rcu(dev);
703 if (!in_dev)
704 return;
705
706 net = dev_net(dev);
707 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
708 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
709 ipv4_is_zeronet(new_gw))
710 goto reject_redirect;
711
712 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
713 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
714 goto reject_redirect;
715 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
716 goto reject_redirect;
717 } else {
718 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
719 goto reject_redirect;
720 }
721
722 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
723 if (n) {
724 if (!(n->nud_state & NUD_VALID)) {
725 neigh_event_send(n, NULL);
726 } else {
727 if (fib_lookup(net, fl4, &res) == 0) {
728 struct fib_nh *nh = &FIB_RES_NH(res);
729
730 update_or_create_fnhe(nh, fl4->daddr, new_gw,
731 0, 0);
732 }
733 if (kill_route)
734 rt->dst.obsolete = DST_OBSOLETE_KILL;
735 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
736 }
737 neigh_release(n);
738 }
739 return;
740
741 reject_redirect:
742 #ifdef CONFIG_IP_ROUTE_VERBOSE
743 if (IN_DEV_LOG_MARTIANS(in_dev)) {
744 const struct iphdr *iph = (const struct iphdr *) skb->data;
745 __be32 daddr = iph->daddr;
746 __be32 saddr = iph->saddr;
747
748 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
749 " Advised path = %pI4 -> %pI4\n",
750 &old_gw, dev->name, &new_gw,
751 &saddr, &daddr);
752 }
753 #endif
754 ;
755 }
756
757 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
758 {
759 struct rtable *rt;
760 struct flowi4 fl4;
761 const struct iphdr *iph = (const struct iphdr *) skb->data;
762 int oif = skb->dev->ifindex;
763 u8 tos = RT_TOS(iph->tos);
764 u8 prot = iph->protocol;
765 u32 mark = skb->mark;
766
767 rt = (struct rtable *) dst;
768
769 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
770 __ip_do_redirect(rt, skb, &fl4, true);
771 }
772
773 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
774 {
775 struct rtable *rt = (struct rtable *)dst;
776 struct dst_entry *ret = dst;
777
778 if (rt) {
779 if (dst->obsolete > 0) {
780 ip_rt_put(rt);
781 ret = NULL;
782 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
783 rt->dst.expires) {
784 ip_rt_put(rt);
785 ret = NULL;
786 }
787 }
788 return ret;
789 }
790
791 /*
792 * Algorithm:
793 * 1. The first ip_rt_redirect_number redirects are sent
794 * with exponential backoff, then we stop sending them at all,
795 * assuming that the host ignores our redirects.
796 * 2. If we did not see packets requiring redirects
797 * during ip_rt_redirect_silence, we assume that the host
798 * forgot redirected route and start to send redirects again.
799 *
800 * This algorithm is much cheaper and more intelligent than dumb load limiting
801 * in icmp.c.
802 *
803 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
804 * and "frag. need" (breaks PMTU discovery) in icmp.c.
805 */
806
807 void ip_rt_send_redirect(struct sk_buff *skb)
808 {
809 struct rtable *rt = skb_rtable(skb);
810 struct in_device *in_dev;
811 struct inet_peer *peer;
812 struct net *net;
813 int log_martians;
814
815 rcu_read_lock();
816 in_dev = __in_dev_get_rcu(rt->dst.dev);
817 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
818 rcu_read_unlock();
819 return;
820 }
821 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
822 rcu_read_unlock();
823
824 net = dev_net(rt->dst.dev);
825 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
826 if (!peer) {
827 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
828 rt_nexthop(rt, ip_hdr(skb)->daddr));
829 return;
830 }
831
832 /* No redirected packets during ip_rt_redirect_silence;
833 * reset the algorithm.
834 */
835 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
836 peer->rate_tokens = 0;
837
838 /* Too many ignored redirects; do not send anything
839 * set dst.rate_last to the last seen redirected packet.
840 */
841 if (peer->rate_tokens >= ip_rt_redirect_number) {
842 peer->rate_last = jiffies;
843 goto out_put_peer;
844 }
845
846 /* Check for load limit; set rate_last to the latest sent
847 * redirect.
848 */
849 if (peer->rate_tokens == 0 ||
850 time_after(jiffies,
851 (peer->rate_last +
852 (ip_rt_redirect_load << peer->rate_tokens)))) {
853 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
854
855 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
856 peer->rate_last = jiffies;
857 ++peer->rate_tokens;
858 #ifdef CONFIG_IP_ROUTE_VERBOSE
859 if (log_martians &&
860 peer->rate_tokens == ip_rt_redirect_number)
861 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
862 &ip_hdr(skb)->saddr, inet_iif(skb),
863 &ip_hdr(skb)->daddr, &gw);
864 #endif
865 }
866 out_put_peer:
867 inet_putpeer(peer);
868 }
869
870 static int ip_error(struct sk_buff *skb)
871 {
872 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
873 struct rtable *rt = skb_rtable(skb);
874 struct inet_peer *peer;
875 unsigned long now;
876 struct net *net;
877 bool send;
878 int code;
879
880 net = dev_net(rt->dst.dev);
881 if (!IN_DEV_FORWARD(in_dev)) {
882 switch (rt->dst.error) {
883 case EHOSTUNREACH:
884 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
885 break;
886
887 case ENETUNREACH:
888 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
889 break;
890 }
891 goto out;
892 }
893
894 switch (rt->dst.error) {
895 case EINVAL:
896 default:
897 goto out;
898 case EHOSTUNREACH:
899 code = ICMP_HOST_UNREACH;
900 break;
901 case ENETUNREACH:
902 code = ICMP_NET_UNREACH;
903 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
904 break;
905 case EACCES:
906 code = ICMP_PKT_FILTERED;
907 break;
908 }
909
910 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
911
912 send = true;
913 if (peer) {
914 now = jiffies;
915 peer->rate_tokens += now - peer->rate_last;
916 if (peer->rate_tokens > ip_rt_error_burst)
917 peer->rate_tokens = ip_rt_error_burst;
918 peer->rate_last = now;
919 if (peer->rate_tokens >= ip_rt_error_cost)
920 peer->rate_tokens -= ip_rt_error_cost;
921 else
922 send = false;
923 inet_putpeer(peer);
924 }
925 if (send)
926 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
927
928 out: kfree_skb(skb);
929 return 0;
930 }
931
932 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
933 {
934 struct dst_entry *dst = &rt->dst;
935 struct fib_result res;
936
937 if (dst_metric_locked(dst, RTAX_MTU))
938 return;
939
940 if (dst->dev->mtu < mtu)
941 return;
942
943 if (mtu < ip_rt_min_pmtu)
944 mtu = ip_rt_min_pmtu;
945
946 if (rt->rt_pmtu == mtu &&
947 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
948 return;
949
950 rcu_read_lock();
951 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
952 struct fib_nh *nh = &FIB_RES_NH(res);
953
954 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
955 jiffies + ip_rt_mtu_expires);
956 }
957 rcu_read_unlock();
958 }
959
960 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
961 struct sk_buff *skb, u32 mtu)
962 {
963 struct rtable *rt = (struct rtable *) dst;
964 struct flowi4 fl4;
965
966 ip_rt_build_flow_key(&fl4, sk, skb);
967 __ip_rt_update_pmtu(rt, &fl4, mtu);
968 }
969
970 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
971 int oif, u32 mark, u8 protocol, int flow_flags)
972 {
973 const struct iphdr *iph = (const struct iphdr *) skb->data;
974 struct flowi4 fl4;
975 struct rtable *rt;
976
977 if (!mark)
978 mark = IP4_REPLY_MARK(net, skb->mark);
979
980 __build_flow_key(&fl4, NULL, iph, oif,
981 RT_TOS(iph->tos), protocol, mark, flow_flags);
982 rt = __ip_route_output_key(net, &fl4);
983 if (!IS_ERR(rt)) {
984 __ip_rt_update_pmtu(rt, &fl4, mtu);
985 ip_rt_put(rt);
986 }
987 }
988 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
989
990 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
991 {
992 const struct iphdr *iph = (const struct iphdr *) skb->data;
993 struct flowi4 fl4;
994 struct rtable *rt;
995
996 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
997
998 if (!fl4.flowi4_mark)
999 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1000
1001 rt = __ip_route_output_key(sock_net(sk), &fl4);
1002 if (!IS_ERR(rt)) {
1003 __ip_rt_update_pmtu(rt, &fl4, mtu);
1004 ip_rt_put(rt);
1005 }
1006 }
1007
1008 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1009 {
1010 const struct iphdr *iph = (const struct iphdr *) skb->data;
1011 struct flowi4 fl4;
1012 struct rtable *rt;
1013 struct dst_entry *odst = NULL;
1014 bool new = false;
1015
1016 bh_lock_sock(sk);
1017
1018 if (!ip_sk_accept_pmtu(sk))
1019 goto out;
1020
1021 odst = sk_dst_get(sk);
1022
1023 if (sock_owned_by_user(sk) || !odst) {
1024 __ipv4_sk_update_pmtu(skb, sk, mtu);
1025 goto out;
1026 }
1027
1028 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1029
1030 rt = (struct rtable *)odst;
1031 if (odst->obsolete && odst->ops->check(odst, 0) == NULL) {
1032 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1033 if (IS_ERR(rt))
1034 goto out;
1035
1036 new = true;
1037 }
1038
1039 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1040
1041 if (!dst_check(&rt->dst, 0)) {
1042 if (new)
1043 dst_release(&rt->dst);
1044
1045 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1046 if (IS_ERR(rt))
1047 goto out;
1048
1049 new = true;
1050 }
1051
1052 if (new)
1053 sk_dst_set(sk, &rt->dst);
1054
1055 out:
1056 bh_unlock_sock(sk);
1057 dst_release(odst);
1058 }
1059 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1060
1061 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1062 int oif, u32 mark, u8 protocol, int flow_flags)
1063 {
1064 const struct iphdr *iph = (const struct iphdr *) skb->data;
1065 struct flowi4 fl4;
1066 struct rtable *rt;
1067
1068 __build_flow_key(&fl4, NULL, iph, oif,
1069 RT_TOS(iph->tos), protocol, mark, flow_flags);
1070 rt = __ip_route_output_key(net, &fl4);
1071 if (!IS_ERR(rt)) {
1072 __ip_do_redirect(rt, skb, &fl4, false);
1073 ip_rt_put(rt);
1074 }
1075 }
1076 EXPORT_SYMBOL_GPL(ipv4_redirect);
1077
1078 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1079 {
1080 const struct iphdr *iph = (const struct iphdr *) skb->data;
1081 struct flowi4 fl4;
1082 struct rtable *rt;
1083
1084 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1085 rt = __ip_route_output_key(sock_net(sk), &fl4);
1086 if (!IS_ERR(rt)) {
1087 __ip_do_redirect(rt, skb, &fl4, false);
1088 ip_rt_put(rt);
1089 }
1090 }
1091 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1092
1093 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1094 {
1095 struct rtable *rt = (struct rtable *) dst;
1096
1097 /* All IPV4 dsts are created with ->obsolete set to the value
1098 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1099 * into this function always.
1100 *
1101 * When a PMTU/redirect information update invalidates a route,
1102 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1103 * DST_OBSOLETE_DEAD by dst_free().
1104 */
1105 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1106 return NULL;
1107 return dst;
1108 }
1109
1110 static void ipv4_link_failure(struct sk_buff *skb)
1111 {
1112 struct rtable *rt;
1113
1114 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1115
1116 rt = skb_rtable(skb);
1117 if (rt)
1118 dst_set_expires(&rt->dst, 0);
1119 }
1120
1121 static int ip_rt_bug(struct sock *sk, struct sk_buff *skb)
1122 {
1123 pr_debug("%s: %pI4 -> %pI4, %s\n",
1124 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1125 skb->dev ? skb->dev->name : "?");
1126 kfree_skb(skb);
1127 WARN_ON(1);
1128 return 0;
1129 }
1130
1131 /*
1132 We do not cache source address of outgoing interface,
1133 because it is used only by IP RR, TS and SRR options,
1134 so that it out of fast path.
1135
1136 BTW remember: "addr" is allowed to be not aligned
1137 in IP options!
1138 */
1139
1140 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1141 {
1142 __be32 src;
1143
1144 if (rt_is_output_route(rt))
1145 src = ip_hdr(skb)->saddr;
1146 else {
1147 struct fib_result res;
1148 struct flowi4 fl4;
1149 struct iphdr *iph;
1150
1151 iph = ip_hdr(skb);
1152
1153 memset(&fl4, 0, sizeof(fl4));
1154 fl4.daddr = iph->daddr;
1155 fl4.saddr = iph->saddr;
1156 fl4.flowi4_tos = RT_TOS(iph->tos);
1157 fl4.flowi4_oif = rt->dst.dev->ifindex;
1158 fl4.flowi4_iif = skb->dev->ifindex;
1159 fl4.flowi4_mark = skb->mark;
1160
1161 rcu_read_lock();
1162 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1163 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1164 else
1165 src = inet_select_addr(rt->dst.dev,
1166 rt_nexthop(rt, iph->daddr),
1167 RT_SCOPE_UNIVERSE);
1168 rcu_read_unlock();
1169 }
1170 memcpy(addr, &src, 4);
1171 }
1172
1173 #ifdef CONFIG_IP_ROUTE_CLASSID
1174 static void set_class_tag(struct rtable *rt, u32 tag)
1175 {
1176 if (!(rt->dst.tclassid & 0xFFFF))
1177 rt->dst.tclassid |= tag & 0xFFFF;
1178 if (!(rt->dst.tclassid & 0xFFFF0000))
1179 rt->dst.tclassid |= tag & 0xFFFF0000;
1180 }
1181 #endif
1182
1183 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1184 {
1185 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1186
1187 if (advmss == 0) {
1188 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1189 ip_rt_min_advmss);
1190 if (advmss > 65535 - 40)
1191 advmss = 65535 - 40;
1192 }
1193 return advmss;
1194 }
1195
1196 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1197 {
1198 const struct rtable *rt = (const struct rtable *) dst;
1199 unsigned int mtu = rt->rt_pmtu;
1200
1201 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1202 mtu = dst_metric_raw(dst, RTAX_MTU);
1203
1204 if (mtu)
1205 return mtu;
1206
1207 mtu = dst->dev->mtu;
1208
1209 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1210 if (rt->rt_uses_gateway && mtu > 576)
1211 mtu = 576;
1212 }
1213
1214 return min_t(unsigned int, mtu, IP_MAX_MTU);
1215 }
1216
1217 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1218 {
1219 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1220 struct fib_nh_exception *fnhe;
1221 u32 hval;
1222
1223 if (!hash)
1224 return NULL;
1225
1226 hval = fnhe_hashfun(daddr);
1227
1228 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1229 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1230 if (fnhe->fnhe_daddr == daddr)
1231 return fnhe;
1232 }
1233 return NULL;
1234 }
1235
1236 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1237 __be32 daddr)
1238 {
1239 bool ret = false;
1240
1241 spin_lock_bh(&fnhe_lock);
1242
1243 if (daddr == fnhe->fnhe_daddr) {
1244 struct rtable __rcu **porig;
1245 struct rtable *orig;
1246 int genid = fnhe_genid(dev_net(rt->dst.dev));
1247
1248 if (rt_is_input_route(rt))
1249 porig = &fnhe->fnhe_rth_input;
1250 else
1251 porig = &fnhe->fnhe_rth_output;
1252 orig = rcu_dereference(*porig);
1253
1254 if (fnhe->fnhe_genid != genid) {
1255 fnhe->fnhe_genid = genid;
1256 fnhe->fnhe_gw = 0;
1257 fnhe->fnhe_pmtu = 0;
1258 fnhe->fnhe_expires = 0;
1259 fnhe_flush_routes(fnhe);
1260 orig = NULL;
1261 }
1262 fill_route_from_fnhe(rt, fnhe);
1263 if (!rt->rt_gateway)
1264 rt->rt_gateway = daddr;
1265
1266 if (!(rt->dst.flags & DST_NOCACHE)) {
1267 rcu_assign_pointer(*porig, rt);
1268 if (orig)
1269 rt_free(orig);
1270 ret = true;
1271 }
1272
1273 fnhe->fnhe_stamp = jiffies;
1274 }
1275 spin_unlock_bh(&fnhe_lock);
1276
1277 return ret;
1278 }
1279
1280 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1281 {
1282 struct rtable *orig, *prev, **p;
1283 bool ret = true;
1284
1285 if (rt_is_input_route(rt)) {
1286 p = (struct rtable **)&nh->nh_rth_input;
1287 } else {
1288 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1289 }
1290 orig = *p;
1291
1292 prev = cmpxchg(p, orig, rt);
1293 if (prev == orig) {
1294 if (orig)
1295 rt_free(orig);
1296 } else
1297 ret = false;
1298
1299 return ret;
1300 }
1301
1302 static DEFINE_SPINLOCK(rt_uncached_lock);
1303 static LIST_HEAD(rt_uncached_list);
1304
1305 static void rt_add_uncached_list(struct rtable *rt)
1306 {
1307 spin_lock_bh(&rt_uncached_lock);
1308 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1309 spin_unlock_bh(&rt_uncached_lock);
1310 }
1311
1312 static void ipv4_dst_destroy(struct dst_entry *dst)
1313 {
1314 struct rtable *rt = (struct rtable *) dst;
1315
1316 if (!list_empty(&rt->rt_uncached)) {
1317 spin_lock_bh(&rt_uncached_lock);
1318 list_del(&rt->rt_uncached);
1319 spin_unlock_bh(&rt_uncached_lock);
1320 }
1321 }
1322
1323 void rt_flush_dev(struct net_device *dev)
1324 {
1325 if (!list_empty(&rt_uncached_list)) {
1326 struct net *net = dev_net(dev);
1327 struct rtable *rt;
1328
1329 spin_lock_bh(&rt_uncached_lock);
1330 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1331 if (rt->dst.dev != dev)
1332 continue;
1333 rt->dst.dev = net->loopback_dev;
1334 dev_hold(rt->dst.dev);
1335 dev_put(dev);
1336 }
1337 spin_unlock_bh(&rt_uncached_lock);
1338 }
1339 }
1340
1341 static bool rt_cache_valid(const struct rtable *rt)
1342 {
1343 return rt &&
1344 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1345 !rt_is_expired(rt);
1346 }
1347
1348 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1349 const struct fib_result *res,
1350 struct fib_nh_exception *fnhe,
1351 struct fib_info *fi, u16 type, u32 itag)
1352 {
1353 bool cached = false;
1354
1355 if (fi) {
1356 struct fib_nh *nh = &FIB_RES_NH(*res);
1357
1358 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1359 rt->rt_gateway = nh->nh_gw;
1360 rt->rt_uses_gateway = 1;
1361 }
1362 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1363 #ifdef CONFIG_IP_ROUTE_CLASSID
1364 rt->dst.tclassid = nh->nh_tclassid;
1365 #endif
1366 if (unlikely(fnhe))
1367 cached = rt_bind_exception(rt, fnhe, daddr);
1368 else if (!(rt->dst.flags & DST_NOCACHE))
1369 cached = rt_cache_route(nh, rt);
1370 if (unlikely(!cached)) {
1371 /* Routes we intend to cache in nexthop exception or
1372 * FIB nexthop have the DST_NOCACHE bit clear.
1373 * However, if we are unsuccessful at storing this
1374 * route into the cache we really need to set it.
1375 */
1376 rt->dst.flags |= DST_NOCACHE;
1377 if (!rt->rt_gateway)
1378 rt->rt_gateway = daddr;
1379 rt_add_uncached_list(rt);
1380 }
1381 } else
1382 rt_add_uncached_list(rt);
1383
1384 #ifdef CONFIG_IP_ROUTE_CLASSID
1385 #ifdef CONFIG_IP_MULTIPLE_TABLES
1386 set_class_tag(rt, res->tclassid);
1387 #endif
1388 set_class_tag(rt, itag);
1389 #endif
1390 }
1391
1392 static struct rtable *rt_dst_alloc(struct net_device *dev,
1393 bool nopolicy, bool noxfrm, bool will_cache)
1394 {
1395 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1396 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1397 (nopolicy ? DST_NOPOLICY : 0) |
1398 (noxfrm ? DST_NOXFRM : 0));
1399 }
1400
1401 /* called in rcu_read_lock() section */
1402 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1403 u8 tos, struct net_device *dev, int our)
1404 {
1405 struct rtable *rth;
1406 struct in_device *in_dev = __in_dev_get_rcu(dev);
1407 u32 itag = 0;
1408 int err;
1409
1410 /* Primary sanity checks. */
1411
1412 if (in_dev == NULL)
1413 return -EINVAL;
1414
1415 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1416 skb->protocol != htons(ETH_P_IP))
1417 goto e_inval;
1418
1419 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1420 if (ipv4_is_loopback(saddr))
1421 goto e_inval;
1422
1423 if (ipv4_is_zeronet(saddr)) {
1424 if (!ipv4_is_local_multicast(daddr))
1425 goto e_inval;
1426 } else {
1427 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1428 in_dev, &itag);
1429 if (err < 0)
1430 goto e_err;
1431 }
1432 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1433 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1434 if (!rth)
1435 goto e_nobufs;
1436
1437 #ifdef CONFIG_IP_ROUTE_CLASSID
1438 rth->dst.tclassid = itag;
1439 #endif
1440 rth->dst.output = ip_rt_bug;
1441
1442 rth->rt_genid = rt_genid_ipv4(dev_net(dev));
1443 rth->rt_flags = RTCF_MULTICAST;
1444 rth->rt_type = RTN_MULTICAST;
1445 rth->rt_is_input= 1;
1446 rth->rt_iif = 0;
1447 rth->rt_pmtu = 0;
1448 rth->rt_gateway = 0;
1449 rth->rt_uses_gateway = 0;
1450 INIT_LIST_HEAD(&rth->rt_uncached);
1451 if (our) {
1452 rth->dst.input= ip_local_deliver;
1453 rth->rt_flags |= RTCF_LOCAL;
1454 }
1455
1456 #ifdef CONFIG_IP_MROUTE
1457 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1458 rth->dst.input = ip_mr_input;
1459 #endif
1460 RT_CACHE_STAT_INC(in_slow_mc);
1461
1462 skb_dst_set(skb, &rth->dst);
1463 return 0;
1464
1465 e_nobufs:
1466 return -ENOBUFS;
1467 e_inval:
1468 return -EINVAL;
1469 e_err:
1470 return err;
1471 }
1472
1473
1474 static void ip_handle_martian_source(struct net_device *dev,
1475 struct in_device *in_dev,
1476 struct sk_buff *skb,
1477 __be32 daddr,
1478 __be32 saddr)
1479 {
1480 RT_CACHE_STAT_INC(in_martian_src);
1481 #ifdef CONFIG_IP_ROUTE_VERBOSE
1482 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1483 /*
1484 * RFC1812 recommendation, if source is martian,
1485 * the only hint is MAC header.
1486 */
1487 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1488 &daddr, &saddr, dev->name);
1489 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1490 print_hex_dump(KERN_WARNING, "ll header: ",
1491 DUMP_PREFIX_OFFSET, 16, 1,
1492 skb_mac_header(skb),
1493 dev->hard_header_len, true);
1494 }
1495 }
1496 #endif
1497 }
1498
1499 /* called in rcu_read_lock() section */
1500 static int __mkroute_input(struct sk_buff *skb,
1501 const struct fib_result *res,
1502 struct in_device *in_dev,
1503 __be32 daddr, __be32 saddr, u32 tos)
1504 {
1505 struct fib_nh_exception *fnhe;
1506 struct rtable *rth;
1507 int err;
1508 struct in_device *out_dev;
1509 unsigned int flags = 0;
1510 bool do_cache;
1511 u32 itag = 0;
1512
1513 /* get a working reference to the output device */
1514 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1515 if (out_dev == NULL) {
1516 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1517 return -EINVAL;
1518 }
1519
1520 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1521 in_dev->dev, in_dev, &itag);
1522 if (err < 0) {
1523 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1524 saddr);
1525
1526 goto cleanup;
1527 }
1528
1529 do_cache = res->fi && !itag;
1530 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1531 (IN_DEV_SHARED_MEDIA(out_dev) ||
1532 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) {
1533 flags |= RTCF_DOREDIRECT;
1534 do_cache = false;
1535 }
1536
1537 if (skb->protocol != htons(ETH_P_IP)) {
1538 /* Not IP (i.e. ARP). Do not create route, if it is
1539 * invalid for proxy arp. DNAT routes are always valid.
1540 *
1541 * Proxy arp feature have been extended to allow, ARP
1542 * replies back to the same interface, to support
1543 * Private VLAN switch technologies. See arp.c.
1544 */
1545 if (out_dev == in_dev &&
1546 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1547 err = -EINVAL;
1548 goto cleanup;
1549 }
1550 }
1551
1552 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1553 if (do_cache) {
1554 if (fnhe != NULL)
1555 rth = rcu_dereference(fnhe->fnhe_rth_input);
1556 else
1557 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1558
1559 if (rt_cache_valid(rth)) {
1560 skb_dst_set_noref(skb, &rth->dst);
1561 goto out;
1562 }
1563 }
1564
1565 rth = rt_dst_alloc(out_dev->dev,
1566 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1567 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1568 if (!rth) {
1569 err = -ENOBUFS;
1570 goto cleanup;
1571 }
1572
1573 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev));
1574 rth->rt_flags = flags;
1575 rth->rt_type = res->type;
1576 rth->rt_is_input = 1;
1577 rth->rt_iif = 0;
1578 rth->rt_pmtu = 0;
1579 rth->rt_gateway = 0;
1580 rth->rt_uses_gateway = 0;
1581 INIT_LIST_HEAD(&rth->rt_uncached);
1582 RT_CACHE_STAT_INC(in_slow_tot);
1583
1584 rth->dst.input = ip_forward;
1585 rth->dst.output = ip_output;
1586
1587 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1588 skb_dst_set(skb, &rth->dst);
1589 out:
1590 err = 0;
1591 cleanup:
1592 return err;
1593 }
1594
1595 static int ip_mkroute_input(struct sk_buff *skb,
1596 struct fib_result *res,
1597 const struct flowi4 *fl4,
1598 struct in_device *in_dev,
1599 __be32 daddr, __be32 saddr, u32 tos)
1600 {
1601 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1602 if (res->fi && res->fi->fib_nhs > 1)
1603 fib_select_multipath(res);
1604 #endif
1605
1606 /* create a routing cache entry */
1607 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1608 }
1609
1610 /*
1611 * NOTE. We drop all the packets that has local source
1612 * addresses, because every properly looped back packet
1613 * must have correct destination already attached by output routine.
1614 *
1615 * Such approach solves two big problems:
1616 * 1. Not simplex devices are handled properly.
1617 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1618 * called with rcu_read_lock()
1619 */
1620
1621 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1622 u8 tos, struct net_device *dev)
1623 {
1624 struct fib_result res;
1625 struct in_device *in_dev = __in_dev_get_rcu(dev);
1626 struct flowi4 fl4;
1627 unsigned int flags = 0;
1628 u32 itag = 0;
1629 struct rtable *rth;
1630 int err = -EINVAL;
1631 struct net *net = dev_net(dev);
1632 bool do_cache;
1633
1634 /* IP on this device is disabled. */
1635
1636 if (!in_dev)
1637 goto out;
1638
1639 /* Check for the most weird martians, which can be not detected
1640 by fib_lookup.
1641 */
1642
1643 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1644 goto martian_source;
1645
1646 res.fi = NULL;
1647 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1648 goto brd_input;
1649
1650 /* Accept zero addresses only to limited broadcast;
1651 * I even do not know to fix it or not. Waiting for complains :-)
1652 */
1653 if (ipv4_is_zeronet(saddr))
1654 goto martian_source;
1655
1656 if (ipv4_is_zeronet(daddr))
1657 goto martian_destination;
1658
1659 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1660 * and call it once if daddr or/and saddr are loopback addresses
1661 */
1662 if (ipv4_is_loopback(daddr)) {
1663 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1664 goto martian_destination;
1665 } else if (ipv4_is_loopback(saddr)) {
1666 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1667 goto martian_source;
1668 }
1669
1670 /*
1671 * Now we are ready to route packet.
1672 */
1673 fl4.flowi4_oif = 0;
1674 fl4.flowi4_iif = dev->ifindex;
1675 fl4.flowi4_mark = skb->mark;
1676 fl4.flowi4_tos = tos;
1677 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1678 fl4.daddr = daddr;
1679 fl4.saddr = saddr;
1680 err = fib_lookup(net, &fl4, &res);
1681 if (err != 0) {
1682 if (!IN_DEV_FORWARD(in_dev))
1683 err = -EHOSTUNREACH;
1684 goto no_route;
1685 }
1686
1687 if (res.type == RTN_BROADCAST)
1688 goto brd_input;
1689
1690 if (res.type == RTN_LOCAL) {
1691 err = fib_validate_source(skb, saddr, daddr, tos,
1692 0, dev, in_dev, &itag);
1693 if (err < 0)
1694 goto martian_source_keep_err;
1695 goto local_input;
1696 }
1697
1698 if (!IN_DEV_FORWARD(in_dev)) {
1699 err = -EHOSTUNREACH;
1700 goto no_route;
1701 }
1702 if (res.type != RTN_UNICAST)
1703 goto martian_destination;
1704
1705 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1706 out: return err;
1707
1708 brd_input:
1709 if (skb->protocol != htons(ETH_P_IP))
1710 goto e_inval;
1711
1712 if (!ipv4_is_zeronet(saddr)) {
1713 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1714 in_dev, &itag);
1715 if (err < 0)
1716 goto martian_source_keep_err;
1717 }
1718 flags |= RTCF_BROADCAST;
1719 res.type = RTN_BROADCAST;
1720 RT_CACHE_STAT_INC(in_brd);
1721
1722 local_input:
1723 do_cache = false;
1724 if (res.fi) {
1725 if (!itag) {
1726 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1727 if (rt_cache_valid(rth)) {
1728 skb_dst_set_noref(skb, &rth->dst);
1729 err = 0;
1730 goto out;
1731 }
1732 do_cache = true;
1733 }
1734 }
1735
1736 rth = rt_dst_alloc(net->loopback_dev,
1737 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1738 if (!rth)
1739 goto e_nobufs;
1740
1741 rth->dst.input= ip_local_deliver;
1742 rth->dst.output= ip_rt_bug;
1743 #ifdef CONFIG_IP_ROUTE_CLASSID
1744 rth->dst.tclassid = itag;
1745 #endif
1746
1747 rth->rt_genid = rt_genid_ipv4(net);
1748 rth->rt_flags = flags|RTCF_LOCAL;
1749 rth->rt_type = res.type;
1750 rth->rt_is_input = 1;
1751 rth->rt_iif = 0;
1752 rth->rt_pmtu = 0;
1753 rth->rt_gateway = 0;
1754 rth->rt_uses_gateway = 0;
1755 INIT_LIST_HEAD(&rth->rt_uncached);
1756 RT_CACHE_STAT_INC(in_slow_tot);
1757 if (res.type == RTN_UNREACHABLE) {
1758 rth->dst.input= ip_error;
1759 rth->dst.error= -err;
1760 rth->rt_flags &= ~RTCF_LOCAL;
1761 }
1762 if (do_cache) {
1763 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1764 rth->dst.flags |= DST_NOCACHE;
1765 rt_add_uncached_list(rth);
1766 }
1767 }
1768 skb_dst_set(skb, &rth->dst);
1769 err = 0;
1770 goto out;
1771
1772 no_route:
1773 RT_CACHE_STAT_INC(in_no_route);
1774 res.type = RTN_UNREACHABLE;
1775 if (err == -ESRCH)
1776 err = -ENETUNREACH;
1777 goto local_input;
1778
1779 /*
1780 * Do not cache martian addresses: they should be logged (RFC1812)
1781 */
1782 martian_destination:
1783 RT_CACHE_STAT_INC(in_martian_dst);
1784 #ifdef CONFIG_IP_ROUTE_VERBOSE
1785 if (IN_DEV_LOG_MARTIANS(in_dev))
1786 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1787 &daddr, &saddr, dev->name);
1788 #endif
1789
1790 e_inval:
1791 err = -EINVAL;
1792 goto out;
1793
1794 e_nobufs:
1795 err = -ENOBUFS;
1796 goto out;
1797
1798 martian_source:
1799 err = -EINVAL;
1800 martian_source_keep_err:
1801 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1802 goto out;
1803 }
1804
1805 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1806 u8 tos, struct net_device *dev)
1807 {
1808 int res;
1809
1810 rcu_read_lock();
1811
1812 /* Multicast recognition logic is moved from route cache to here.
1813 The problem was that too many Ethernet cards have broken/missing
1814 hardware multicast filters :-( As result the host on multicasting
1815 network acquires a lot of useless route cache entries, sort of
1816 SDR messages from all the world. Now we try to get rid of them.
1817 Really, provided software IP multicast filter is organized
1818 reasonably (at least, hashed), it does not result in a slowdown
1819 comparing with route cache reject entries.
1820 Note, that multicast routers are not affected, because
1821 route cache entry is created eventually.
1822 */
1823 if (ipv4_is_multicast(daddr)) {
1824 struct in_device *in_dev = __in_dev_get_rcu(dev);
1825
1826 if (in_dev) {
1827 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1828 ip_hdr(skb)->protocol);
1829 if (our
1830 #ifdef CONFIG_IP_MROUTE
1831 ||
1832 (!ipv4_is_local_multicast(daddr) &&
1833 IN_DEV_MFORWARD(in_dev))
1834 #endif
1835 ) {
1836 int res = ip_route_input_mc(skb, daddr, saddr,
1837 tos, dev, our);
1838 rcu_read_unlock();
1839 return res;
1840 }
1841 }
1842 rcu_read_unlock();
1843 return -EINVAL;
1844 }
1845 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1846 rcu_read_unlock();
1847 return res;
1848 }
1849 EXPORT_SYMBOL(ip_route_input_noref);
1850
1851 /* called with rcu_read_lock() */
1852 static struct rtable *__mkroute_output(const struct fib_result *res,
1853 const struct flowi4 *fl4, int orig_oif,
1854 struct net_device *dev_out,
1855 unsigned int flags)
1856 {
1857 struct fib_info *fi = res->fi;
1858 struct fib_nh_exception *fnhe;
1859 struct in_device *in_dev;
1860 u16 type = res->type;
1861 struct rtable *rth;
1862 bool do_cache;
1863
1864 in_dev = __in_dev_get_rcu(dev_out);
1865 if (!in_dev)
1866 return ERR_PTR(-EINVAL);
1867
1868 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1869 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1870 return ERR_PTR(-EINVAL);
1871
1872 if (ipv4_is_lbcast(fl4->daddr))
1873 type = RTN_BROADCAST;
1874 else if (ipv4_is_multicast(fl4->daddr))
1875 type = RTN_MULTICAST;
1876 else if (ipv4_is_zeronet(fl4->daddr))
1877 return ERR_PTR(-EINVAL);
1878
1879 if (dev_out->flags & IFF_LOOPBACK)
1880 flags |= RTCF_LOCAL;
1881
1882 do_cache = true;
1883 if (type == RTN_BROADCAST) {
1884 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1885 fi = NULL;
1886 } else if (type == RTN_MULTICAST) {
1887 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1888 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1889 fl4->flowi4_proto))
1890 flags &= ~RTCF_LOCAL;
1891 else
1892 do_cache = false;
1893 /* If multicast route do not exist use
1894 * default one, but do not gateway in this case.
1895 * Yes, it is hack.
1896 */
1897 if (fi && res->prefixlen < 4)
1898 fi = NULL;
1899 }
1900
1901 fnhe = NULL;
1902 do_cache &= fi != NULL;
1903 if (do_cache) {
1904 struct rtable __rcu **prth;
1905 struct fib_nh *nh = &FIB_RES_NH(*res);
1906
1907 fnhe = find_exception(nh, fl4->daddr);
1908 if (fnhe)
1909 prth = &fnhe->fnhe_rth_output;
1910 else {
1911 if (unlikely(fl4->flowi4_flags &
1912 FLOWI_FLAG_KNOWN_NH &&
1913 !(nh->nh_gw &&
1914 nh->nh_scope == RT_SCOPE_LINK))) {
1915 do_cache = false;
1916 goto add;
1917 }
1918 prth = __this_cpu_ptr(nh->nh_pcpu_rth_output);
1919 }
1920 rth = rcu_dereference(*prth);
1921 if (rt_cache_valid(rth)) {
1922 dst_hold(&rth->dst);
1923 return rth;
1924 }
1925 }
1926
1927 add:
1928 rth = rt_dst_alloc(dev_out,
1929 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1930 IN_DEV_CONF_GET(in_dev, NOXFRM),
1931 do_cache);
1932 if (!rth)
1933 return ERR_PTR(-ENOBUFS);
1934
1935 rth->dst.output = ip_output;
1936
1937 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out));
1938 rth->rt_flags = flags;
1939 rth->rt_type = type;
1940 rth->rt_is_input = 0;
1941 rth->rt_iif = orig_oif ? : 0;
1942 rth->rt_pmtu = 0;
1943 rth->rt_gateway = 0;
1944 rth->rt_uses_gateway = 0;
1945 INIT_LIST_HEAD(&rth->rt_uncached);
1946
1947 RT_CACHE_STAT_INC(out_slow_tot);
1948
1949 if (flags & RTCF_LOCAL)
1950 rth->dst.input = ip_local_deliver;
1951 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1952 if (flags & RTCF_LOCAL &&
1953 !(dev_out->flags & IFF_LOOPBACK)) {
1954 rth->dst.output = ip_mc_output;
1955 RT_CACHE_STAT_INC(out_slow_mc);
1956 }
1957 #ifdef CONFIG_IP_MROUTE
1958 if (type == RTN_MULTICAST) {
1959 if (IN_DEV_MFORWARD(in_dev) &&
1960 !ipv4_is_local_multicast(fl4->daddr)) {
1961 rth->dst.input = ip_mr_input;
1962 rth->dst.output = ip_mc_output;
1963 }
1964 }
1965 #endif
1966 }
1967
1968 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1969
1970 return rth;
1971 }
1972
1973 /*
1974 * Major route resolver routine.
1975 */
1976
1977 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1978 {
1979 struct net_device *dev_out = NULL;
1980 __u8 tos = RT_FL_TOS(fl4);
1981 unsigned int flags = 0;
1982 struct fib_result res;
1983 struct rtable *rth;
1984 int orig_oif;
1985
1986 res.tclassid = 0;
1987 res.fi = NULL;
1988 res.table = NULL;
1989
1990 orig_oif = fl4->flowi4_oif;
1991
1992 fl4->flowi4_iif = LOOPBACK_IFINDEX;
1993 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
1994 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
1995 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
1996
1997 rcu_read_lock();
1998 if (fl4->saddr) {
1999 rth = ERR_PTR(-EINVAL);
2000 if (ipv4_is_multicast(fl4->saddr) ||
2001 ipv4_is_lbcast(fl4->saddr) ||
2002 ipv4_is_zeronet(fl4->saddr))
2003 goto out;
2004
2005 /* I removed check for oif == dev_out->oif here.
2006 It was wrong for two reasons:
2007 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2008 is assigned to multiple interfaces.
2009 2. Moreover, we are allowed to send packets with saddr
2010 of another iface. --ANK
2011 */
2012
2013 if (fl4->flowi4_oif == 0 &&
2014 (ipv4_is_multicast(fl4->daddr) ||
2015 ipv4_is_lbcast(fl4->daddr))) {
2016 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2017 dev_out = __ip_dev_find(net, fl4->saddr, false);
2018 if (dev_out == NULL)
2019 goto out;
2020
2021 /* Special hack: user can direct multicasts
2022 and limited broadcast via necessary interface
2023 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2024 This hack is not just for fun, it allows
2025 vic,vat and friends to work.
2026 They bind socket to loopback, set ttl to zero
2027 and expect that it will work.
2028 From the viewpoint of routing cache they are broken,
2029 because we are not allowed to build multicast path
2030 with loopback source addr (look, routing cache
2031 cannot know, that ttl is zero, so that packet
2032 will not leave this host and route is valid).
2033 Luckily, this hack is good workaround.
2034 */
2035
2036 fl4->flowi4_oif = dev_out->ifindex;
2037 goto make_route;
2038 }
2039
2040 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2041 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2042 if (!__ip_dev_find(net, fl4->saddr, false))
2043 goto out;
2044 }
2045 }
2046
2047
2048 if (fl4->flowi4_oif) {
2049 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2050 rth = ERR_PTR(-ENODEV);
2051 if (dev_out == NULL)
2052 goto out;
2053
2054 /* RACE: Check return value of inet_select_addr instead. */
2055 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2056 rth = ERR_PTR(-ENETUNREACH);
2057 goto out;
2058 }
2059 if (ipv4_is_local_multicast(fl4->daddr) ||
2060 ipv4_is_lbcast(fl4->daddr)) {
2061 if (!fl4->saddr)
2062 fl4->saddr = inet_select_addr(dev_out, 0,
2063 RT_SCOPE_LINK);
2064 goto make_route;
2065 }
2066 if (!fl4->saddr) {
2067 if (ipv4_is_multicast(fl4->daddr))
2068 fl4->saddr = inet_select_addr(dev_out, 0,
2069 fl4->flowi4_scope);
2070 else if (!fl4->daddr)
2071 fl4->saddr = inet_select_addr(dev_out, 0,
2072 RT_SCOPE_HOST);
2073 }
2074 }
2075
2076 if (!fl4->daddr) {
2077 fl4->daddr = fl4->saddr;
2078 if (!fl4->daddr)
2079 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2080 dev_out = net->loopback_dev;
2081 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2082 res.type = RTN_LOCAL;
2083 flags |= RTCF_LOCAL;
2084 goto make_route;
2085 }
2086
2087 if (fib_lookup(net, fl4, &res)) {
2088 res.fi = NULL;
2089 res.table = NULL;
2090 if (fl4->flowi4_oif) {
2091 /* Apparently, routing tables are wrong. Assume,
2092 that the destination is on link.
2093
2094 WHY? DW.
2095 Because we are allowed to send to iface
2096 even if it has NO routes and NO assigned
2097 addresses. When oif is specified, routing
2098 tables are looked up with only one purpose:
2099 to catch if destination is gatewayed, rather than
2100 direct. Moreover, if MSG_DONTROUTE is set,
2101 we send packet, ignoring both routing tables
2102 and ifaddr state. --ANK
2103
2104
2105 We could make it even if oif is unknown,
2106 likely IPv6, but we do not.
2107 */
2108
2109 if (fl4->saddr == 0)
2110 fl4->saddr = inet_select_addr(dev_out, 0,
2111 RT_SCOPE_LINK);
2112 res.type = RTN_UNICAST;
2113 goto make_route;
2114 }
2115 rth = ERR_PTR(-ENETUNREACH);
2116 goto out;
2117 }
2118
2119 if (res.type == RTN_LOCAL) {
2120 if (!fl4->saddr) {
2121 if (res.fi->fib_prefsrc)
2122 fl4->saddr = res.fi->fib_prefsrc;
2123 else
2124 fl4->saddr = fl4->daddr;
2125 }
2126 dev_out = net->loopback_dev;
2127 fl4->flowi4_oif = dev_out->ifindex;
2128 flags |= RTCF_LOCAL;
2129 goto make_route;
2130 }
2131
2132 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2133 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2134 fib_select_multipath(&res);
2135 else
2136 #endif
2137 if (!res.prefixlen &&
2138 res.table->tb_num_default > 1 &&
2139 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2140 fib_select_default(&res);
2141
2142 if (!fl4->saddr)
2143 fl4->saddr = FIB_RES_PREFSRC(net, res);
2144
2145 dev_out = FIB_RES_DEV(res);
2146 fl4->flowi4_oif = dev_out->ifindex;
2147
2148
2149 make_route:
2150 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2151
2152 out:
2153 rcu_read_unlock();
2154 return rth;
2155 }
2156 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2157
2158 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2159 {
2160 return NULL;
2161 }
2162
2163 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2164 {
2165 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2166
2167 return mtu ? : dst->dev->mtu;
2168 }
2169
2170 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2171 struct sk_buff *skb, u32 mtu)
2172 {
2173 }
2174
2175 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2176 struct sk_buff *skb)
2177 {
2178 }
2179
2180 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2181 unsigned long old)
2182 {
2183 return NULL;
2184 }
2185
2186 static struct dst_ops ipv4_dst_blackhole_ops = {
2187 .family = AF_INET,
2188 .protocol = cpu_to_be16(ETH_P_IP),
2189 .check = ipv4_blackhole_dst_check,
2190 .mtu = ipv4_blackhole_mtu,
2191 .default_advmss = ipv4_default_advmss,
2192 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2193 .redirect = ipv4_rt_blackhole_redirect,
2194 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2195 .neigh_lookup = ipv4_neigh_lookup,
2196 };
2197
2198 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2199 {
2200 struct rtable *ort = (struct rtable *) dst_orig;
2201 struct rtable *rt;
2202
2203 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2204 if (rt) {
2205 struct dst_entry *new = &rt->dst;
2206
2207 new->__use = 1;
2208 new->input = dst_discard;
2209 new->output = dst_discard_sk;
2210
2211 new->dev = ort->dst.dev;
2212 if (new->dev)
2213 dev_hold(new->dev);
2214
2215 rt->rt_is_input = ort->rt_is_input;
2216 rt->rt_iif = ort->rt_iif;
2217 rt->rt_pmtu = ort->rt_pmtu;
2218
2219 rt->rt_genid = rt_genid_ipv4(net);
2220 rt->rt_flags = ort->rt_flags;
2221 rt->rt_type = ort->rt_type;
2222 rt->rt_gateway = ort->rt_gateway;
2223 rt->rt_uses_gateway = ort->rt_uses_gateway;
2224
2225 INIT_LIST_HEAD(&rt->rt_uncached);
2226
2227 dst_free(new);
2228 }
2229
2230 dst_release(dst_orig);
2231
2232 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2233 }
2234
2235 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2236 struct sock *sk)
2237 {
2238 struct rtable *rt = __ip_route_output_key(net, flp4);
2239
2240 if (IS_ERR(rt))
2241 return rt;
2242
2243 if (flp4->flowi4_proto)
2244 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2245 flowi4_to_flowi(flp4),
2246 sk, 0);
2247
2248 return rt;
2249 }
2250 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2251
2252 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2253 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2254 u32 seq, int event, int nowait, unsigned int flags)
2255 {
2256 struct rtable *rt = skb_rtable(skb);
2257 struct rtmsg *r;
2258 struct nlmsghdr *nlh;
2259 unsigned long expires = 0;
2260 u32 error;
2261 u32 metrics[RTAX_MAX];
2262
2263 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2264 if (nlh == NULL)
2265 return -EMSGSIZE;
2266
2267 r = nlmsg_data(nlh);
2268 r->rtm_family = AF_INET;
2269 r->rtm_dst_len = 32;
2270 r->rtm_src_len = 0;
2271 r->rtm_tos = fl4->flowi4_tos;
2272 r->rtm_table = RT_TABLE_MAIN;
2273 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2274 goto nla_put_failure;
2275 r->rtm_type = rt->rt_type;
2276 r->rtm_scope = RT_SCOPE_UNIVERSE;
2277 r->rtm_protocol = RTPROT_UNSPEC;
2278 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2279 if (rt->rt_flags & RTCF_NOTIFY)
2280 r->rtm_flags |= RTM_F_NOTIFY;
2281
2282 if (nla_put_be32(skb, RTA_DST, dst))
2283 goto nla_put_failure;
2284 if (src) {
2285 r->rtm_src_len = 32;
2286 if (nla_put_be32(skb, RTA_SRC, src))
2287 goto nla_put_failure;
2288 }
2289 if (rt->dst.dev &&
2290 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2291 goto nla_put_failure;
2292 #ifdef CONFIG_IP_ROUTE_CLASSID
2293 if (rt->dst.tclassid &&
2294 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2295 goto nla_put_failure;
2296 #endif
2297 if (!rt_is_input_route(rt) &&
2298 fl4->saddr != src) {
2299 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2300 goto nla_put_failure;
2301 }
2302 if (rt->rt_uses_gateway &&
2303 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2304 goto nla_put_failure;
2305
2306 expires = rt->dst.expires;
2307 if (expires) {
2308 unsigned long now = jiffies;
2309
2310 if (time_before(now, expires))
2311 expires -= now;
2312 else
2313 expires = 0;
2314 }
2315
2316 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2317 if (rt->rt_pmtu && expires)
2318 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2319 if (rtnetlink_put_metrics(skb, metrics) < 0)
2320 goto nla_put_failure;
2321
2322 if (fl4->flowi4_mark &&
2323 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2324 goto nla_put_failure;
2325
2326 error = rt->dst.error;
2327
2328 if (rt_is_input_route(rt)) {
2329 #ifdef CONFIG_IP_MROUTE
2330 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2331 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2332 int err = ipmr_get_route(net, skb,
2333 fl4->saddr, fl4->daddr,
2334 r, nowait);
2335 if (err <= 0) {
2336 if (!nowait) {
2337 if (err == 0)
2338 return 0;
2339 goto nla_put_failure;
2340 } else {
2341 if (err == -EMSGSIZE)
2342 goto nla_put_failure;
2343 error = err;
2344 }
2345 }
2346 } else
2347 #endif
2348 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2349 goto nla_put_failure;
2350 }
2351
2352 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2353 goto nla_put_failure;
2354
2355 return nlmsg_end(skb, nlh);
2356
2357 nla_put_failure:
2358 nlmsg_cancel(skb, nlh);
2359 return -EMSGSIZE;
2360 }
2361
2362 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2363 {
2364 struct net *net = sock_net(in_skb->sk);
2365 struct rtmsg *rtm;
2366 struct nlattr *tb[RTA_MAX+1];
2367 struct rtable *rt = NULL;
2368 struct flowi4 fl4;
2369 __be32 dst = 0;
2370 __be32 src = 0;
2371 u32 iif;
2372 int err;
2373 int mark;
2374 struct sk_buff *skb;
2375
2376 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2377 if (err < 0)
2378 goto errout;
2379
2380 rtm = nlmsg_data(nlh);
2381
2382 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2383 if (skb == NULL) {
2384 err = -ENOBUFS;
2385 goto errout;
2386 }
2387
2388 /* Reserve room for dummy headers, this skb can pass
2389 through good chunk of routing engine.
2390 */
2391 skb_reset_mac_header(skb);
2392 skb_reset_network_header(skb);
2393
2394 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2395 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2396 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2397
2398 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2399 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2400 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2401 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2402
2403 memset(&fl4, 0, sizeof(fl4));
2404 fl4.daddr = dst;
2405 fl4.saddr = src;
2406 fl4.flowi4_tos = rtm->rtm_tos;
2407 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2408 fl4.flowi4_mark = mark;
2409
2410 if (iif) {
2411 struct net_device *dev;
2412
2413 dev = __dev_get_by_index(net, iif);
2414 if (dev == NULL) {
2415 err = -ENODEV;
2416 goto errout_free;
2417 }
2418
2419 skb->protocol = htons(ETH_P_IP);
2420 skb->dev = dev;
2421 skb->mark = mark;
2422 local_bh_disable();
2423 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2424 local_bh_enable();
2425
2426 rt = skb_rtable(skb);
2427 if (err == 0 && rt->dst.error)
2428 err = -rt->dst.error;
2429 } else {
2430 rt = ip_route_output_key(net, &fl4);
2431
2432 err = 0;
2433 if (IS_ERR(rt))
2434 err = PTR_ERR(rt);
2435 }
2436
2437 if (err)
2438 goto errout_free;
2439
2440 skb_dst_set(skb, &rt->dst);
2441 if (rtm->rtm_flags & RTM_F_NOTIFY)
2442 rt->rt_flags |= RTCF_NOTIFY;
2443
2444 err = rt_fill_info(net, dst, src, &fl4, skb,
2445 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2446 RTM_NEWROUTE, 0, 0);
2447 if (err <= 0)
2448 goto errout_free;
2449
2450 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2451 errout:
2452 return err;
2453
2454 errout_free:
2455 kfree_skb(skb);
2456 goto errout;
2457 }
2458
2459 void ip_rt_multicast_event(struct in_device *in_dev)
2460 {
2461 rt_cache_flush(dev_net(in_dev->dev));
2462 }
2463
2464 #ifdef CONFIG_SYSCTL
2465 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2466 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2467 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2468 static int ip_rt_gc_elasticity __read_mostly = 8;
2469
2470 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2471 void __user *buffer,
2472 size_t *lenp, loff_t *ppos)
2473 {
2474 struct net *net = (struct net *)__ctl->extra1;
2475
2476 if (write) {
2477 rt_cache_flush(net);
2478 fnhe_genid_bump(net);
2479 return 0;
2480 }
2481
2482 return -EINVAL;
2483 }
2484
2485 static struct ctl_table ipv4_route_table[] = {
2486 {
2487 .procname = "gc_thresh",
2488 .data = &ipv4_dst_ops.gc_thresh,
2489 .maxlen = sizeof(int),
2490 .mode = 0644,
2491 .proc_handler = proc_dointvec,
2492 },
2493 {
2494 .procname = "max_size",
2495 .data = &ip_rt_max_size,
2496 .maxlen = sizeof(int),
2497 .mode = 0644,
2498 .proc_handler = proc_dointvec,
2499 },
2500 {
2501 /* Deprecated. Use gc_min_interval_ms */
2502
2503 .procname = "gc_min_interval",
2504 .data = &ip_rt_gc_min_interval,
2505 .maxlen = sizeof(int),
2506 .mode = 0644,
2507 .proc_handler = proc_dointvec_jiffies,
2508 },
2509 {
2510 .procname = "gc_min_interval_ms",
2511 .data = &ip_rt_gc_min_interval,
2512 .maxlen = sizeof(int),
2513 .mode = 0644,
2514 .proc_handler = proc_dointvec_ms_jiffies,
2515 },
2516 {
2517 .procname = "gc_timeout",
2518 .data = &ip_rt_gc_timeout,
2519 .maxlen = sizeof(int),
2520 .mode = 0644,
2521 .proc_handler = proc_dointvec_jiffies,
2522 },
2523 {
2524 .procname = "gc_interval",
2525 .data = &ip_rt_gc_interval,
2526 .maxlen = sizeof(int),
2527 .mode = 0644,
2528 .proc_handler = proc_dointvec_jiffies,
2529 },
2530 {
2531 .procname = "redirect_load",
2532 .data = &ip_rt_redirect_load,
2533 .maxlen = sizeof(int),
2534 .mode = 0644,
2535 .proc_handler = proc_dointvec,
2536 },
2537 {
2538 .procname = "redirect_number",
2539 .data = &ip_rt_redirect_number,
2540 .maxlen = sizeof(int),
2541 .mode = 0644,
2542 .proc_handler = proc_dointvec,
2543 },
2544 {
2545 .procname = "redirect_silence",
2546 .data = &ip_rt_redirect_silence,
2547 .maxlen = sizeof(int),
2548 .mode = 0644,
2549 .proc_handler = proc_dointvec,
2550 },
2551 {
2552 .procname = "error_cost",
2553 .data = &ip_rt_error_cost,
2554 .maxlen = sizeof(int),
2555 .mode = 0644,
2556 .proc_handler = proc_dointvec,
2557 },
2558 {
2559 .procname = "error_burst",
2560 .data = &ip_rt_error_burst,
2561 .maxlen = sizeof(int),
2562 .mode = 0644,
2563 .proc_handler = proc_dointvec,
2564 },
2565 {
2566 .procname = "gc_elasticity",
2567 .data = &ip_rt_gc_elasticity,
2568 .maxlen = sizeof(int),
2569 .mode = 0644,
2570 .proc_handler = proc_dointvec,
2571 },
2572 {
2573 .procname = "mtu_expires",
2574 .data = &ip_rt_mtu_expires,
2575 .maxlen = sizeof(int),
2576 .mode = 0644,
2577 .proc_handler = proc_dointvec_jiffies,
2578 },
2579 {
2580 .procname = "min_pmtu",
2581 .data = &ip_rt_min_pmtu,
2582 .maxlen = sizeof(int),
2583 .mode = 0644,
2584 .proc_handler = proc_dointvec,
2585 },
2586 {
2587 .procname = "min_adv_mss",
2588 .data = &ip_rt_min_advmss,
2589 .maxlen = sizeof(int),
2590 .mode = 0644,
2591 .proc_handler = proc_dointvec,
2592 },
2593 { }
2594 };
2595
2596 static struct ctl_table ipv4_route_flush_table[] = {
2597 {
2598 .procname = "flush",
2599 .maxlen = sizeof(int),
2600 .mode = 0200,
2601 .proc_handler = ipv4_sysctl_rtcache_flush,
2602 },
2603 { },
2604 };
2605
2606 static __net_init int sysctl_route_net_init(struct net *net)
2607 {
2608 struct ctl_table *tbl;
2609
2610 tbl = ipv4_route_flush_table;
2611 if (!net_eq(net, &init_net)) {
2612 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2613 if (tbl == NULL)
2614 goto err_dup;
2615
2616 /* Don't export sysctls to unprivileged users */
2617 if (net->user_ns != &init_user_ns)
2618 tbl[0].procname = NULL;
2619 }
2620 tbl[0].extra1 = net;
2621
2622 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2623 if (net->ipv4.route_hdr == NULL)
2624 goto err_reg;
2625 return 0;
2626
2627 err_reg:
2628 if (tbl != ipv4_route_flush_table)
2629 kfree(tbl);
2630 err_dup:
2631 return -ENOMEM;
2632 }
2633
2634 static __net_exit void sysctl_route_net_exit(struct net *net)
2635 {
2636 struct ctl_table *tbl;
2637
2638 tbl = net->ipv4.route_hdr->ctl_table_arg;
2639 unregister_net_sysctl_table(net->ipv4.route_hdr);
2640 BUG_ON(tbl == ipv4_route_flush_table);
2641 kfree(tbl);
2642 }
2643
2644 static __net_initdata struct pernet_operations sysctl_route_ops = {
2645 .init = sysctl_route_net_init,
2646 .exit = sysctl_route_net_exit,
2647 };
2648 #endif
2649
2650 static __net_init int rt_genid_init(struct net *net)
2651 {
2652 atomic_set(&net->ipv4.rt_genid, 0);
2653 atomic_set(&net->fnhe_genid, 0);
2654 get_random_bytes(&net->ipv4.dev_addr_genid,
2655 sizeof(net->ipv4.dev_addr_genid));
2656 return 0;
2657 }
2658
2659 static __net_initdata struct pernet_operations rt_genid_ops = {
2660 .init = rt_genid_init,
2661 };
2662
2663 static int __net_init ipv4_inetpeer_init(struct net *net)
2664 {
2665 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2666
2667 if (!bp)
2668 return -ENOMEM;
2669 inet_peer_base_init(bp);
2670 net->ipv4.peers = bp;
2671 return 0;
2672 }
2673
2674 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2675 {
2676 struct inet_peer_base *bp = net->ipv4.peers;
2677
2678 net->ipv4.peers = NULL;
2679 inetpeer_invalidate_tree(bp);
2680 kfree(bp);
2681 }
2682
2683 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2684 .init = ipv4_inetpeer_init,
2685 .exit = ipv4_inetpeer_exit,
2686 };
2687
2688 #ifdef CONFIG_IP_ROUTE_CLASSID
2689 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2690 #endif /* CONFIG_IP_ROUTE_CLASSID */
2691
2692 int __init ip_rt_init(void)
2693 {
2694 int rc = 0;
2695
2696 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2697 if (!ip_idents)
2698 panic("IP: failed to allocate ip_idents\n");
2699
2700 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2701
2702 #ifdef CONFIG_IP_ROUTE_CLASSID
2703 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2704 if (!ip_rt_acct)
2705 panic("IP: failed to allocate ip_rt_acct\n");
2706 #endif
2707
2708 ipv4_dst_ops.kmem_cachep =
2709 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2710 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2711
2712 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2713
2714 if (dst_entries_init(&ipv4_dst_ops) < 0)
2715 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2716
2717 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2718 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2719
2720 ipv4_dst_ops.gc_thresh = ~0;
2721 ip_rt_max_size = INT_MAX;
2722
2723 devinet_init();
2724 ip_fib_init();
2725
2726 if (ip_rt_proc_init())
2727 pr_err("Unable to create route proc files\n");
2728 #ifdef CONFIG_XFRM
2729 xfrm_init();
2730 xfrm4_init();
2731 #endif
2732 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2733
2734 #ifdef CONFIG_SYSCTL
2735 register_pernet_subsys(&sysctl_route_ops);
2736 #endif
2737 register_pernet_subsys(&rt_genid_ops);
2738 register_pernet_subsys(&ipv4_inetpeer_ops);
2739 return rc;
2740 }
2741
2742 #ifdef CONFIG_SYSCTL
2743 /*
2744 * We really need to sanitize the damn ipv4 init order, then all
2745 * this nonsense will go away.
2746 */
2747 void __init ip_static_sysctl_init(void)
2748 {
2749 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2750 }
2751 #endif
Linux kernel - Deliverables
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