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iommu/exynos: Fix checkpatch warning
[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 <net/dst.h>
93 #include <net/net_namespace.h>
94 #include <net/protocol.h>
95 #include <net/ip.h>
96 #include <net/route.h>
97 #include <net/inetpeer.h>
98 #include <net/sock.h>
99 #include <net/ip_fib.h>
100 #include <net/arp.h>
101 #include <net/tcp.h>
102 #include <net/icmp.h>
103 #include <net/xfrm.h>
104 #include <net/netevent.h>
105 #include <net/rtnetlink.h>
106 #ifdef CONFIG_SYSCTL
107 #include <linux/sysctl.h>
108 #include <linux/kmemleak.h>
109 #endif
110 #include <net/secure_seq.h>
111
112 #define RT_FL_TOS(oldflp4) \
113 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
114
115 #define RT_GC_TIMEOUT (300*HZ)
116
117 static int ip_rt_max_size;
118 static int ip_rt_redirect_number __read_mostly = 9;
119 static int ip_rt_redirect_load __read_mostly = HZ / 50;
120 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
121 static int ip_rt_error_cost __read_mostly = HZ;
122 static int ip_rt_error_burst __read_mostly = 5 * HZ;
123 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
124 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
125 static int ip_rt_min_advmss __read_mostly = 256;
126
127 /*
128 * Interface to generic destination cache.
129 */
130
131 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
132 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
133 static unsigned int ipv4_mtu(const struct dst_entry *dst);
134 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
135 static void ipv4_link_failure(struct sk_buff *skb);
136 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
137 struct sk_buff *skb, u32 mtu);
138 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
139 struct sk_buff *skb);
140 static void ipv4_dst_destroy(struct dst_entry *dst);
141
142 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
143 {
144 WARN_ON(1);
145 return NULL;
146 }
147
148 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
149 struct sk_buff *skb,
150 const void *daddr);
151
152 static struct dst_ops ipv4_dst_ops = {
153 .family = AF_INET,
154 .protocol = cpu_to_be16(ETH_P_IP),
155 .check = ipv4_dst_check,
156 .default_advmss = ipv4_default_advmss,
157 .mtu = ipv4_mtu,
158 .cow_metrics = ipv4_cow_metrics,
159 .destroy = ipv4_dst_destroy,
160 .negative_advice = ipv4_negative_advice,
161 .link_failure = ipv4_link_failure,
162 .update_pmtu = ip_rt_update_pmtu,
163 .redirect = ip_do_redirect,
164 .local_out = __ip_local_out,
165 .neigh_lookup = ipv4_neigh_lookup,
166 };
167
168 #define ECN_OR_COST(class) TC_PRIO_##class
169
170 const __u8 ip_tos2prio[16] = {
171 TC_PRIO_BESTEFFORT,
172 ECN_OR_COST(BESTEFFORT),
173 TC_PRIO_BESTEFFORT,
174 ECN_OR_COST(BESTEFFORT),
175 TC_PRIO_BULK,
176 ECN_OR_COST(BULK),
177 TC_PRIO_BULK,
178 ECN_OR_COST(BULK),
179 TC_PRIO_INTERACTIVE,
180 ECN_OR_COST(INTERACTIVE),
181 TC_PRIO_INTERACTIVE,
182 ECN_OR_COST(INTERACTIVE),
183 TC_PRIO_INTERACTIVE_BULK,
184 ECN_OR_COST(INTERACTIVE_BULK),
185 TC_PRIO_INTERACTIVE_BULK,
186 ECN_OR_COST(INTERACTIVE_BULK)
187 };
188 EXPORT_SYMBOL(ip_tos2prio);
189
190 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
191 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
192
193 #ifdef CONFIG_PROC_FS
194 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
195 {
196 if (*pos)
197 return NULL;
198 return SEQ_START_TOKEN;
199 }
200
201 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
202 {
203 ++*pos;
204 return NULL;
205 }
206
207 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
208 {
209 }
210
211 static int rt_cache_seq_show(struct seq_file *seq, void *v)
212 {
213 if (v == SEQ_START_TOKEN)
214 seq_printf(seq, "%-127s\n",
215 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
216 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
217 "HHUptod\tSpecDst");
218 return 0;
219 }
220
221 static const struct seq_operations rt_cache_seq_ops = {
222 .start = rt_cache_seq_start,
223 .next = rt_cache_seq_next,
224 .stop = rt_cache_seq_stop,
225 .show = rt_cache_seq_show,
226 };
227
228 static int rt_cache_seq_open(struct inode *inode, struct file *file)
229 {
230 return seq_open(file, &rt_cache_seq_ops);
231 }
232
233 static const struct file_operations rt_cache_seq_fops = {
234 .owner = THIS_MODULE,
235 .open = rt_cache_seq_open,
236 .read = seq_read,
237 .llseek = seq_lseek,
238 .release = seq_release,
239 };
240
241
242 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
243 {
244 int cpu;
245
246 if (*pos == 0)
247 return SEQ_START_TOKEN;
248
249 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
250 if (!cpu_possible(cpu))
251 continue;
252 *pos = cpu+1;
253 return &per_cpu(rt_cache_stat, cpu);
254 }
255 return NULL;
256 }
257
258 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
259 {
260 int cpu;
261
262 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
263 if (!cpu_possible(cpu))
264 continue;
265 *pos = cpu+1;
266 return &per_cpu(rt_cache_stat, cpu);
267 }
268 return NULL;
269
270 }
271
272 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
273 {
274
275 }
276
277 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
278 {
279 struct rt_cache_stat *st = v;
280
281 if (v == SEQ_START_TOKEN) {
282 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");
283 return 0;
284 }
285
286 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
287 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
288 dst_entries_get_slow(&ipv4_dst_ops),
289 0, /* st->in_hit */
290 st->in_slow_tot,
291 st->in_slow_mc,
292 st->in_no_route,
293 st->in_brd,
294 st->in_martian_dst,
295 st->in_martian_src,
296
297 0, /* st->out_hit */
298 st->out_slow_tot,
299 st->out_slow_mc,
300
301 0, /* st->gc_total */
302 0, /* st->gc_ignored */
303 0, /* st->gc_goal_miss */
304 0, /* st->gc_dst_overflow */
305 0, /* st->in_hlist_search */
306 0 /* st->out_hlist_search */
307 );
308 return 0;
309 }
310
311 static const struct seq_operations rt_cpu_seq_ops = {
312 .start = rt_cpu_seq_start,
313 .next = rt_cpu_seq_next,
314 .stop = rt_cpu_seq_stop,
315 .show = rt_cpu_seq_show,
316 };
317
318
319 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
320 {
321 return seq_open(file, &rt_cpu_seq_ops);
322 }
323
324 static const struct file_operations rt_cpu_seq_fops = {
325 .owner = THIS_MODULE,
326 .open = rt_cpu_seq_open,
327 .read = seq_read,
328 .llseek = seq_lseek,
329 .release = seq_release,
330 };
331
332 #ifdef CONFIG_IP_ROUTE_CLASSID
333 static int rt_acct_proc_show(struct seq_file *m, void *v)
334 {
335 struct ip_rt_acct *dst, *src;
336 unsigned int i, j;
337
338 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
339 if (!dst)
340 return -ENOMEM;
341
342 for_each_possible_cpu(i) {
343 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
344 for (j = 0; j < 256; j++) {
345 dst[j].o_bytes += src[j].o_bytes;
346 dst[j].o_packets += src[j].o_packets;
347 dst[j].i_bytes += src[j].i_bytes;
348 dst[j].i_packets += src[j].i_packets;
349 }
350 }
351
352 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
353 kfree(dst);
354 return 0;
355 }
356
357 static int rt_acct_proc_open(struct inode *inode, struct file *file)
358 {
359 return single_open(file, rt_acct_proc_show, NULL);
360 }
361
362 static const struct file_operations rt_acct_proc_fops = {
363 .owner = THIS_MODULE,
364 .open = rt_acct_proc_open,
365 .read = seq_read,
366 .llseek = seq_lseek,
367 .release = single_release,
368 };
369 #endif
370
371 static int __net_init ip_rt_do_proc_init(struct net *net)
372 {
373 struct proc_dir_entry *pde;
374
375 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
376 &rt_cache_seq_fops);
377 if (!pde)
378 goto err1;
379
380 pde = proc_create("rt_cache", S_IRUGO,
381 net->proc_net_stat, &rt_cpu_seq_fops);
382 if (!pde)
383 goto err2;
384
385 #ifdef CONFIG_IP_ROUTE_CLASSID
386 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
387 if (!pde)
388 goto err3;
389 #endif
390 return 0;
391
392 #ifdef CONFIG_IP_ROUTE_CLASSID
393 err3:
394 remove_proc_entry("rt_cache", net->proc_net_stat);
395 #endif
396 err2:
397 remove_proc_entry("rt_cache", net->proc_net);
398 err1:
399 return -ENOMEM;
400 }
401
402 static void __net_exit ip_rt_do_proc_exit(struct net *net)
403 {
404 remove_proc_entry("rt_cache", net->proc_net_stat);
405 remove_proc_entry("rt_cache", net->proc_net);
406 #ifdef CONFIG_IP_ROUTE_CLASSID
407 remove_proc_entry("rt_acct", net->proc_net);
408 #endif
409 }
410
411 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
412 .init = ip_rt_do_proc_init,
413 .exit = ip_rt_do_proc_exit,
414 };
415
416 static int __init ip_rt_proc_init(void)
417 {
418 return register_pernet_subsys(&ip_rt_proc_ops);
419 }
420
421 #else
422 static inline int ip_rt_proc_init(void)
423 {
424 return 0;
425 }
426 #endif /* CONFIG_PROC_FS */
427
428 static inline bool rt_is_expired(const struct rtable *rth)
429 {
430 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
431 }
432
433 void rt_cache_flush(struct net *net)
434 {
435 rt_genid_bump_ipv4(net);
436 }
437
438 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
439 struct sk_buff *skb,
440 const void *daddr)
441 {
442 struct net_device *dev = dst->dev;
443 const __be32 *pkey = daddr;
444 const struct rtable *rt;
445 struct neighbour *n;
446
447 rt = (const struct rtable *) dst;
448 if (rt->rt_gateway)
449 pkey = (const __be32 *) &rt->rt_gateway;
450 else if (skb)
451 pkey = &ip_hdr(skb)->daddr;
452
453 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
454 if (n)
455 return n;
456 return neigh_create(&arp_tbl, pkey, dev);
457 }
458
459 /*
460 * Peer allocation may fail only in serious out-of-memory conditions. However
461 * we still can generate some output.
462 * Random ID selection looks a bit dangerous because we have no chances to
463 * select ID being unique in a reasonable period of time.
464 * But broken packet identifier may be better than no packet at all.
465 */
466 static void ip_select_fb_ident(struct iphdr *iph)
467 {
468 static DEFINE_SPINLOCK(ip_fb_id_lock);
469 static u32 ip_fallback_id;
470 u32 salt;
471
472 spin_lock_bh(&ip_fb_id_lock);
473 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
474 iph->id = htons(salt & 0xFFFF);
475 ip_fallback_id = salt;
476 spin_unlock_bh(&ip_fb_id_lock);
477 }
478
479 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
480 {
481 struct net *net = dev_net(dst->dev);
482 struct inet_peer *peer;
483
484 peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1);
485 if (peer) {
486 iph->id = htons(inet_getid(peer, more));
487 inet_putpeer(peer);
488 return;
489 }
490
491 ip_select_fb_ident(iph);
492 }
493 EXPORT_SYMBOL(__ip_select_ident);
494
495 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
496 const struct iphdr *iph,
497 int oif, u8 tos,
498 u8 prot, u32 mark, int flow_flags)
499 {
500 if (sk) {
501 const struct inet_sock *inet = inet_sk(sk);
502
503 oif = sk->sk_bound_dev_if;
504 mark = sk->sk_mark;
505 tos = RT_CONN_FLAGS(sk);
506 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
507 }
508 flowi4_init_output(fl4, oif, mark, tos,
509 RT_SCOPE_UNIVERSE, prot,
510 flow_flags,
511 iph->daddr, iph->saddr, 0, 0);
512 }
513
514 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
515 const struct sock *sk)
516 {
517 const struct iphdr *iph = ip_hdr(skb);
518 int oif = skb->dev->ifindex;
519 u8 tos = RT_TOS(iph->tos);
520 u8 prot = iph->protocol;
521 u32 mark = skb->mark;
522
523 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
524 }
525
526 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
527 {
528 const struct inet_sock *inet = inet_sk(sk);
529 const struct ip_options_rcu *inet_opt;
530 __be32 daddr = inet->inet_daddr;
531
532 rcu_read_lock();
533 inet_opt = rcu_dereference(inet->inet_opt);
534 if (inet_opt && inet_opt->opt.srr)
535 daddr = inet_opt->opt.faddr;
536 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
537 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
538 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
539 inet_sk_flowi_flags(sk),
540 daddr, inet->inet_saddr, 0, 0);
541 rcu_read_unlock();
542 }
543
544 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
545 const struct sk_buff *skb)
546 {
547 if (skb)
548 build_skb_flow_key(fl4, skb, sk);
549 else
550 build_sk_flow_key(fl4, sk);
551 }
552
553 static inline void rt_free(struct rtable *rt)
554 {
555 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
556 }
557
558 static DEFINE_SPINLOCK(fnhe_lock);
559
560 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
561 {
562 struct rtable *rt;
563
564 rt = rcu_dereference(fnhe->fnhe_rth_input);
565 if (rt) {
566 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
567 rt_free(rt);
568 }
569 rt = rcu_dereference(fnhe->fnhe_rth_output);
570 if (rt) {
571 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
572 rt_free(rt);
573 }
574 }
575
576 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
577 {
578 struct fib_nh_exception *fnhe, *oldest;
579
580 oldest = rcu_dereference(hash->chain);
581 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
582 fnhe = rcu_dereference(fnhe->fnhe_next)) {
583 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
584 oldest = fnhe;
585 }
586 fnhe_flush_routes(oldest);
587 return oldest;
588 }
589
590 static inline u32 fnhe_hashfun(__be32 daddr)
591 {
592 u32 hval;
593
594 hval = (__force u32) daddr;
595 hval ^= (hval >> 11) ^ (hval >> 22);
596
597 return hval & (FNHE_HASH_SIZE - 1);
598 }
599
600 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
601 {
602 rt->rt_pmtu = fnhe->fnhe_pmtu;
603 rt->dst.expires = fnhe->fnhe_expires;
604
605 if (fnhe->fnhe_gw) {
606 rt->rt_flags |= RTCF_REDIRECTED;
607 rt->rt_gateway = fnhe->fnhe_gw;
608 rt->rt_uses_gateway = 1;
609 }
610 }
611
612 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
613 u32 pmtu, unsigned long expires)
614 {
615 struct fnhe_hash_bucket *hash;
616 struct fib_nh_exception *fnhe;
617 struct rtable *rt;
618 unsigned int i;
619 int depth;
620 u32 hval = fnhe_hashfun(daddr);
621
622 spin_lock_bh(&fnhe_lock);
623
624 hash = nh->nh_exceptions;
625 if (!hash) {
626 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
627 if (!hash)
628 goto out_unlock;
629 nh->nh_exceptions = hash;
630 }
631
632 hash += hval;
633
634 depth = 0;
635 for (fnhe = rcu_dereference(hash->chain); fnhe;
636 fnhe = rcu_dereference(fnhe->fnhe_next)) {
637 if (fnhe->fnhe_daddr == daddr)
638 break;
639 depth++;
640 }
641
642 if (fnhe) {
643 if (gw)
644 fnhe->fnhe_gw = gw;
645 if (pmtu) {
646 fnhe->fnhe_pmtu = pmtu;
647 fnhe->fnhe_expires = max(1UL, expires);
648 }
649 /* Update all cached dsts too */
650 rt = rcu_dereference(fnhe->fnhe_rth_input);
651 if (rt)
652 fill_route_from_fnhe(rt, fnhe);
653 rt = rcu_dereference(fnhe->fnhe_rth_output);
654 if (rt)
655 fill_route_from_fnhe(rt, fnhe);
656 } else {
657 if (depth > FNHE_RECLAIM_DEPTH)
658 fnhe = fnhe_oldest(hash);
659 else {
660 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
661 if (!fnhe)
662 goto out_unlock;
663
664 fnhe->fnhe_next = hash->chain;
665 rcu_assign_pointer(hash->chain, fnhe);
666 }
667 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
668 fnhe->fnhe_daddr = daddr;
669 fnhe->fnhe_gw = gw;
670 fnhe->fnhe_pmtu = pmtu;
671 fnhe->fnhe_expires = expires;
672
673 /* Exception created; mark the cached routes for the nexthop
674 * stale, so anyone caching it rechecks if this exception
675 * applies to them.
676 */
677 rt = rcu_dereference(nh->nh_rth_input);
678 if (rt)
679 rt->dst.obsolete = DST_OBSOLETE_KILL;
680
681 for_each_possible_cpu(i) {
682 struct rtable __rcu **prt;
683 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
684 rt = rcu_dereference(*prt);
685 if (rt)
686 rt->dst.obsolete = DST_OBSOLETE_KILL;
687 }
688 }
689
690 fnhe->fnhe_stamp = jiffies;
691
692 out_unlock:
693 spin_unlock_bh(&fnhe_lock);
694 }
695
696 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
697 bool kill_route)
698 {
699 __be32 new_gw = icmp_hdr(skb)->un.gateway;
700 __be32 old_gw = ip_hdr(skb)->saddr;
701 struct net_device *dev = skb->dev;
702 struct in_device *in_dev;
703 struct fib_result res;
704 struct neighbour *n;
705 struct net *net;
706
707 switch (icmp_hdr(skb)->code & 7) {
708 case ICMP_REDIR_NET:
709 case ICMP_REDIR_NETTOS:
710 case ICMP_REDIR_HOST:
711 case ICMP_REDIR_HOSTTOS:
712 break;
713
714 default:
715 return;
716 }
717
718 if (rt->rt_gateway != old_gw)
719 return;
720
721 in_dev = __in_dev_get_rcu(dev);
722 if (!in_dev)
723 return;
724
725 net = dev_net(dev);
726 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
727 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
728 ipv4_is_zeronet(new_gw))
729 goto reject_redirect;
730
731 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
732 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
733 goto reject_redirect;
734 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
735 goto reject_redirect;
736 } else {
737 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
738 goto reject_redirect;
739 }
740
741 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
742 if (n) {
743 if (!(n->nud_state & NUD_VALID)) {
744 neigh_event_send(n, NULL);
745 } else {
746 if (fib_lookup(net, fl4, &res) == 0) {
747 struct fib_nh *nh = &FIB_RES_NH(res);
748
749 update_or_create_fnhe(nh, fl4->daddr, new_gw,
750 0, 0);
751 }
752 if (kill_route)
753 rt->dst.obsolete = DST_OBSOLETE_KILL;
754 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
755 }
756 neigh_release(n);
757 }
758 return;
759
760 reject_redirect:
761 #ifdef CONFIG_IP_ROUTE_VERBOSE
762 if (IN_DEV_LOG_MARTIANS(in_dev)) {
763 const struct iphdr *iph = (const struct iphdr *) skb->data;
764 __be32 daddr = iph->daddr;
765 __be32 saddr = iph->saddr;
766
767 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
768 " Advised path = %pI4 -> %pI4\n",
769 &old_gw, dev->name, &new_gw,
770 &saddr, &daddr);
771 }
772 #endif
773 ;
774 }
775
776 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
777 {
778 struct rtable *rt;
779 struct flowi4 fl4;
780 const struct iphdr *iph = (const struct iphdr *) skb->data;
781 int oif = skb->dev->ifindex;
782 u8 tos = RT_TOS(iph->tos);
783 u8 prot = iph->protocol;
784 u32 mark = skb->mark;
785
786 rt = (struct rtable *) dst;
787
788 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
789 __ip_do_redirect(rt, skb, &fl4, true);
790 }
791
792 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
793 {
794 struct rtable *rt = (struct rtable *)dst;
795 struct dst_entry *ret = dst;
796
797 if (rt) {
798 if (dst->obsolete > 0) {
799 ip_rt_put(rt);
800 ret = NULL;
801 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
802 rt->dst.expires) {
803 ip_rt_put(rt);
804 ret = NULL;
805 }
806 }
807 return ret;
808 }
809
810 /*
811 * Algorithm:
812 * 1. The first ip_rt_redirect_number redirects are sent
813 * with exponential backoff, then we stop sending them at all,
814 * assuming that the host ignores our redirects.
815 * 2. If we did not see packets requiring redirects
816 * during ip_rt_redirect_silence, we assume that the host
817 * forgot redirected route and start to send redirects again.
818 *
819 * This algorithm is much cheaper and more intelligent than dumb load limiting
820 * in icmp.c.
821 *
822 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
823 * and "frag. need" (breaks PMTU discovery) in icmp.c.
824 */
825
826 void ip_rt_send_redirect(struct sk_buff *skb)
827 {
828 struct rtable *rt = skb_rtable(skb);
829 struct in_device *in_dev;
830 struct inet_peer *peer;
831 struct net *net;
832 int log_martians;
833
834 rcu_read_lock();
835 in_dev = __in_dev_get_rcu(rt->dst.dev);
836 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
837 rcu_read_unlock();
838 return;
839 }
840 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
841 rcu_read_unlock();
842
843 net = dev_net(rt->dst.dev);
844 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
845 if (!peer) {
846 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
847 rt_nexthop(rt, ip_hdr(skb)->daddr));
848 return;
849 }
850
851 /* No redirected packets during ip_rt_redirect_silence;
852 * reset the algorithm.
853 */
854 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
855 peer->rate_tokens = 0;
856
857 /* Too many ignored redirects; do not send anything
858 * set dst.rate_last to the last seen redirected packet.
859 */
860 if (peer->rate_tokens >= ip_rt_redirect_number) {
861 peer->rate_last = jiffies;
862 goto out_put_peer;
863 }
864
865 /* Check for load limit; set rate_last to the latest sent
866 * redirect.
867 */
868 if (peer->rate_tokens == 0 ||
869 time_after(jiffies,
870 (peer->rate_last +
871 (ip_rt_redirect_load << peer->rate_tokens)))) {
872 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
873
874 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
875 peer->rate_last = jiffies;
876 ++peer->rate_tokens;
877 #ifdef CONFIG_IP_ROUTE_VERBOSE
878 if (log_martians &&
879 peer->rate_tokens == ip_rt_redirect_number)
880 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
881 &ip_hdr(skb)->saddr, inet_iif(skb),
882 &ip_hdr(skb)->daddr, &gw);
883 #endif
884 }
885 out_put_peer:
886 inet_putpeer(peer);
887 }
888
889 static int ip_error(struct sk_buff *skb)
890 {
891 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
892 struct rtable *rt = skb_rtable(skb);
893 struct inet_peer *peer;
894 unsigned long now;
895 struct net *net;
896 bool send;
897 int code;
898
899 net = dev_net(rt->dst.dev);
900 if (!IN_DEV_FORWARD(in_dev)) {
901 switch (rt->dst.error) {
902 case EHOSTUNREACH:
903 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
904 break;
905
906 case ENETUNREACH:
907 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
908 break;
909 }
910 goto out;
911 }
912
913 switch (rt->dst.error) {
914 case EINVAL:
915 default:
916 goto out;
917 case EHOSTUNREACH:
918 code = ICMP_HOST_UNREACH;
919 break;
920 case ENETUNREACH:
921 code = ICMP_NET_UNREACH;
922 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
923 break;
924 case EACCES:
925 code = ICMP_PKT_FILTERED;
926 break;
927 }
928
929 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
930
931 send = true;
932 if (peer) {
933 now = jiffies;
934 peer->rate_tokens += now - peer->rate_last;
935 if (peer->rate_tokens > ip_rt_error_burst)
936 peer->rate_tokens = ip_rt_error_burst;
937 peer->rate_last = now;
938 if (peer->rate_tokens >= ip_rt_error_cost)
939 peer->rate_tokens -= ip_rt_error_cost;
940 else
941 send = false;
942 inet_putpeer(peer);
943 }
944 if (send)
945 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
946
947 out: kfree_skb(skb);
948 return 0;
949 }
950
951 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
952 {
953 struct dst_entry *dst = &rt->dst;
954 struct fib_result res;
955
956 if (dst_metric_locked(dst, RTAX_MTU))
957 return;
958
959 if (dst->dev->mtu < mtu)
960 return;
961
962 if (mtu < ip_rt_min_pmtu)
963 mtu = ip_rt_min_pmtu;
964
965 if (rt->rt_pmtu == mtu &&
966 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
967 return;
968
969 rcu_read_lock();
970 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
971 struct fib_nh *nh = &FIB_RES_NH(res);
972
973 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
974 jiffies + ip_rt_mtu_expires);
975 }
976 rcu_read_unlock();
977 }
978
979 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
980 struct sk_buff *skb, u32 mtu)
981 {
982 struct rtable *rt = (struct rtable *) dst;
983 struct flowi4 fl4;
984
985 ip_rt_build_flow_key(&fl4, sk, skb);
986 __ip_rt_update_pmtu(rt, &fl4, mtu);
987 }
988
989 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
990 int oif, u32 mark, u8 protocol, int flow_flags)
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, NULL, iph, oif,
997 RT_TOS(iph->tos), protocol, mark, flow_flags);
998 rt = __ip_route_output_key(net, &fl4);
999 if (!IS_ERR(rt)) {
1000 __ip_rt_update_pmtu(rt, &fl4, mtu);
1001 ip_rt_put(rt);
1002 }
1003 }
1004 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1005
1006 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1007 {
1008 const struct iphdr *iph = (const struct iphdr *) skb->data;
1009 struct flowi4 fl4;
1010 struct rtable *rt;
1011
1012 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1013 rt = __ip_route_output_key(sock_net(sk), &fl4);
1014 if (!IS_ERR(rt)) {
1015 __ip_rt_update_pmtu(rt, &fl4, mtu);
1016 ip_rt_put(rt);
1017 }
1018 }
1019
1020 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1021 {
1022 const struct iphdr *iph = (const struct iphdr *) skb->data;
1023 struct flowi4 fl4;
1024 struct rtable *rt;
1025 struct dst_entry *dst;
1026 bool new = false;
1027
1028 bh_lock_sock(sk);
1029
1030 if (!ip_sk_accept_pmtu(sk))
1031 goto out;
1032
1033 rt = (struct rtable *) __sk_dst_get(sk);
1034
1035 if (sock_owned_by_user(sk) || !rt) {
1036 __ipv4_sk_update_pmtu(skb, sk, mtu);
1037 goto out;
1038 }
1039
1040 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1041
1042 if (!__sk_dst_check(sk, 0)) {
1043 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1044 if (IS_ERR(rt))
1045 goto out;
1046
1047 new = true;
1048 }
1049
1050 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1051
1052 dst = dst_check(&rt->dst, 0);
1053 if (!dst) {
1054 if (new)
1055 dst_release(&rt->dst);
1056
1057 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1058 if (IS_ERR(rt))
1059 goto out;
1060
1061 new = true;
1062 }
1063
1064 if (new)
1065 __sk_dst_set(sk, &rt->dst);
1066
1067 out:
1068 bh_unlock_sock(sk);
1069 }
1070 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1071
1072 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1073 int oif, u32 mark, u8 protocol, int flow_flags)
1074 {
1075 const struct iphdr *iph = (const struct iphdr *) skb->data;
1076 struct flowi4 fl4;
1077 struct rtable *rt;
1078
1079 __build_flow_key(&fl4, NULL, iph, oif,
1080 RT_TOS(iph->tos), protocol, mark, flow_flags);
1081 rt = __ip_route_output_key(net, &fl4);
1082 if (!IS_ERR(rt)) {
1083 __ip_do_redirect(rt, skb, &fl4, false);
1084 ip_rt_put(rt);
1085 }
1086 }
1087 EXPORT_SYMBOL_GPL(ipv4_redirect);
1088
1089 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1090 {
1091 const struct iphdr *iph = (const struct iphdr *) skb->data;
1092 struct flowi4 fl4;
1093 struct rtable *rt;
1094
1095 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1096 rt = __ip_route_output_key(sock_net(sk), &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_sk_redirect);
1103
1104 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1105 {
1106 struct rtable *rt = (struct rtable *) dst;
1107
1108 /* All IPV4 dsts are created with ->obsolete set to the value
1109 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1110 * into this function always.
1111 *
1112 * When a PMTU/redirect information update invalidates a route,
1113 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1114 * DST_OBSOLETE_DEAD by dst_free().
1115 */
1116 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1117 return NULL;
1118 return dst;
1119 }
1120
1121 static void ipv4_link_failure(struct sk_buff *skb)
1122 {
1123 struct rtable *rt;
1124
1125 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1126
1127 rt = skb_rtable(skb);
1128 if (rt)
1129 dst_set_expires(&rt->dst, 0);
1130 }
1131
1132 static int ip_rt_bug(struct sock *sk, struct sk_buff *skb)
1133 {
1134 pr_debug("%s: %pI4 -> %pI4, %s\n",
1135 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1136 skb->dev ? skb->dev->name : "?");
1137 kfree_skb(skb);
1138 WARN_ON(1);
1139 return 0;
1140 }
1141
1142 /*
1143 We do not cache source address of outgoing interface,
1144 because it is used only by IP RR, TS and SRR options,
1145 so that it out of fast path.
1146
1147 BTW remember: "addr" is allowed to be not aligned
1148 in IP options!
1149 */
1150
1151 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1152 {
1153 __be32 src;
1154
1155 if (rt_is_output_route(rt))
1156 src = ip_hdr(skb)->saddr;
1157 else {
1158 struct fib_result res;
1159 struct flowi4 fl4;
1160 struct iphdr *iph;
1161
1162 iph = ip_hdr(skb);
1163
1164 memset(&fl4, 0, sizeof(fl4));
1165 fl4.daddr = iph->daddr;
1166 fl4.saddr = iph->saddr;
1167 fl4.flowi4_tos = RT_TOS(iph->tos);
1168 fl4.flowi4_oif = rt->dst.dev->ifindex;
1169 fl4.flowi4_iif = skb->dev->ifindex;
1170 fl4.flowi4_mark = skb->mark;
1171
1172 rcu_read_lock();
1173 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1174 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1175 else
1176 src = inet_select_addr(rt->dst.dev,
1177 rt_nexthop(rt, iph->daddr),
1178 RT_SCOPE_UNIVERSE);
1179 rcu_read_unlock();
1180 }
1181 memcpy(addr, &src, 4);
1182 }
1183
1184 #ifdef CONFIG_IP_ROUTE_CLASSID
1185 static void set_class_tag(struct rtable *rt, u32 tag)
1186 {
1187 if (!(rt->dst.tclassid & 0xFFFF))
1188 rt->dst.tclassid |= tag & 0xFFFF;
1189 if (!(rt->dst.tclassid & 0xFFFF0000))
1190 rt->dst.tclassid |= tag & 0xFFFF0000;
1191 }
1192 #endif
1193
1194 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1195 {
1196 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1197
1198 if (advmss == 0) {
1199 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1200 ip_rt_min_advmss);
1201 if (advmss > 65535 - 40)
1202 advmss = 65535 - 40;
1203 }
1204 return advmss;
1205 }
1206
1207 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1208 {
1209 const struct rtable *rt = (const struct rtable *) dst;
1210 unsigned int mtu = rt->rt_pmtu;
1211
1212 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1213 mtu = dst_metric_raw(dst, RTAX_MTU);
1214
1215 if (mtu)
1216 return mtu;
1217
1218 mtu = dst->dev->mtu;
1219
1220 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1221 if (rt->rt_uses_gateway && mtu > 576)
1222 mtu = 576;
1223 }
1224
1225 return min_t(unsigned int, mtu, IP_MAX_MTU);
1226 }
1227
1228 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1229 {
1230 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1231 struct fib_nh_exception *fnhe;
1232 u32 hval;
1233
1234 if (!hash)
1235 return NULL;
1236
1237 hval = fnhe_hashfun(daddr);
1238
1239 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1240 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1241 if (fnhe->fnhe_daddr == daddr)
1242 return fnhe;
1243 }
1244 return NULL;
1245 }
1246
1247 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1248 __be32 daddr)
1249 {
1250 bool ret = false;
1251
1252 spin_lock_bh(&fnhe_lock);
1253
1254 if (daddr == fnhe->fnhe_daddr) {
1255 struct rtable __rcu **porig;
1256 struct rtable *orig;
1257 int genid = fnhe_genid(dev_net(rt->dst.dev));
1258
1259 if (rt_is_input_route(rt))
1260 porig = &fnhe->fnhe_rth_input;
1261 else
1262 porig = &fnhe->fnhe_rth_output;
1263 orig = rcu_dereference(*porig);
1264
1265 if (fnhe->fnhe_genid != genid) {
1266 fnhe->fnhe_genid = genid;
1267 fnhe->fnhe_gw = 0;
1268 fnhe->fnhe_pmtu = 0;
1269 fnhe->fnhe_expires = 0;
1270 fnhe_flush_routes(fnhe);
1271 orig = NULL;
1272 }
1273 fill_route_from_fnhe(rt, fnhe);
1274 if (!rt->rt_gateway)
1275 rt->rt_gateway = daddr;
1276
1277 if (!(rt->dst.flags & DST_NOCACHE)) {
1278 rcu_assign_pointer(*porig, rt);
1279 if (orig)
1280 rt_free(orig);
1281 ret = true;
1282 }
1283
1284 fnhe->fnhe_stamp = jiffies;
1285 }
1286 spin_unlock_bh(&fnhe_lock);
1287
1288 return ret;
1289 }
1290
1291 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1292 {
1293 struct rtable *orig, *prev, **p;
1294 bool ret = true;
1295
1296 if (rt_is_input_route(rt)) {
1297 p = (struct rtable **)&nh->nh_rth_input;
1298 } else {
1299 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1300 }
1301 orig = *p;
1302
1303 prev = cmpxchg(p, orig, rt);
1304 if (prev == orig) {
1305 if (orig)
1306 rt_free(orig);
1307 } else
1308 ret = false;
1309
1310 return ret;
1311 }
1312
1313 static DEFINE_SPINLOCK(rt_uncached_lock);
1314 static LIST_HEAD(rt_uncached_list);
1315
1316 static void rt_add_uncached_list(struct rtable *rt)
1317 {
1318 spin_lock_bh(&rt_uncached_lock);
1319 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1320 spin_unlock_bh(&rt_uncached_lock);
1321 }
1322
1323 static void ipv4_dst_destroy(struct dst_entry *dst)
1324 {
1325 struct rtable *rt = (struct rtable *) dst;
1326
1327 if (!list_empty(&rt->rt_uncached)) {
1328 spin_lock_bh(&rt_uncached_lock);
1329 list_del(&rt->rt_uncached);
1330 spin_unlock_bh(&rt_uncached_lock);
1331 }
1332 }
1333
1334 void rt_flush_dev(struct net_device *dev)
1335 {
1336 if (!list_empty(&rt_uncached_list)) {
1337 struct net *net = dev_net(dev);
1338 struct rtable *rt;
1339
1340 spin_lock_bh(&rt_uncached_lock);
1341 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1342 if (rt->dst.dev != dev)
1343 continue;
1344 rt->dst.dev = net->loopback_dev;
1345 dev_hold(rt->dst.dev);
1346 dev_put(dev);
1347 }
1348 spin_unlock_bh(&rt_uncached_lock);
1349 }
1350 }
1351
1352 static bool rt_cache_valid(const struct rtable *rt)
1353 {
1354 return rt &&
1355 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1356 !rt_is_expired(rt);
1357 }
1358
1359 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1360 const struct fib_result *res,
1361 struct fib_nh_exception *fnhe,
1362 struct fib_info *fi, u16 type, u32 itag)
1363 {
1364 bool cached = false;
1365
1366 if (fi) {
1367 struct fib_nh *nh = &FIB_RES_NH(*res);
1368
1369 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1370 rt->rt_gateway = nh->nh_gw;
1371 rt->rt_uses_gateway = 1;
1372 }
1373 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1374 #ifdef CONFIG_IP_ROUTE_CLASSID
1375 rt->dst.tclassid = nh->nh_tclassid;
1376 #endif
1377 if (unlikely(fnhe))
1378 cached = rt_bind_exception(rt, fnhe, daddr);
1379 else if (!(rt->dst.flags & DST_NOCACHE))
1380 cached = rt_cache_route(nh, rt);
1381 if (unlikely(!cached)) {
1382 /* Routes we intend to cache in nexthop exception or
1383 * FIB nexthop have the DST_NOCACHE bit clear.
1384 * However, if we are unsuccessful at storing this
1385 * route into the cache we really need to set it.
1386 */
1387 rt->dst.flags |= DST_NOCACHE;
1388 if (!rt->rt_gateway)
1389 rt->rt_gateway = daddr;
1390 rt_add_uncached_list(rt);
1391 }
1392 } else
1393 rt_add_uncached_list(rt);
1394
1395 #ifdef CONFIG_IP_ROUTE_CLASSID
1396 #ifdef CONFIG_IP_MULTIPLE_TABLES
1397 set_class_tag(rt, res->tclassid);
1398 #endif
1399 set_class_tag(rt, itag);
1400 #endif
1401 }
1402
1403 static struct rtable *rt_dst_alloc(struct net_device *dev,
1404 bool nopolicy, bool noxfrm, bool will_cache)
1405 {
1406 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1407 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1408 (nopolicy ? DST_NOPOLICY : 0) |
1409 (noxfrm ? DST_NOXFRM : 0));
1410 }
1411
1412 /* called in rcu_read_lock() section */
1413 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1414 u8 tos, struct net_device *dev, int our)
1415 {
1416 struct rtable *rth;
1417 struct in_device *in_dev = __in_dev_get_rcu(dev);
1418 u32 itag = 0;
1419 int err;
1420
1421 /* Primary sanity checks. */
1422
1423 if (in_dev == NULL)
1424 return -EINVAL;
1425
1426 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1427 skb->protocol != htons(ETH_P_IP))
1428 goto e_inval;
1429
1430 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1431 if (ipv4_is_loopback(saddr))
1432 goto e_inval;
1433
1434 if (ipv4_is_zeronet(saddr)) {
1435 if (!ipv4_is_local_multicast(daddr))
1436 goto e_inval;
1437 } else {
1438 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1439 in_dev, &itag);
1440 if (err < 0)
1441 goto e_err;
1442 }
1443 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1444 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1445 if (!rth)
1446 goto e_nobufs;
1447
1448 #ifdef CONFIG_IP_ROUTE_CLASSID
1449 rth->dst.tclassid = itag;
1450 #endif
1451 rth->dst.output = ip_rt_bug;
1452
1453 rth->rt_genid = rt_genid_ipv4(dev_net(dev));
1454 rth->rt_flags = RTCF_MULTICAST;
1455 rth->rt_type = RTN_MULTICAST;
1456 rth->rt_is_input= 1;
1457 rth->rt_iif = 0;
1458 rth->rt_pmtu = 0;
1459 rth->rt_gateway = 0;
1460 rth->rt_uses_gateway = 0;
1461 INIT_LIST_HEAD(&rth->rt_uncached);
1462 if (our) {
1463 rth->dst.input= ip_local_deliver;
1464 rth->rt_flags |= RTCF_LOCAL;
1465 }
1466
1467 #ifdef CONFIG_IP_MROUTE
1468 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1469 rth->dst.input = ip_mr_input;
1470 #endif
1471 RT_CACHE_STAT_INC(in_slow_mc);
1472
1473 skb_dst_set(skb, &rth->dst);
1474 return 0;
1475
1476 e_nobufs:
1477 return -ENOBUFS;
1478 e_inval:
1479 return -EINVAL;
1480 e_err:
1481 return err;
1482 }
1483
1484
1485 static void ip_handle_martian_source(struct net_device *dev,
1486 struct in_device *in_dev,
1487 struct sk_buff *skb,
1488 __be32 daddr,
1489 __be32 saddr)
1490 {
1491 RT_CACHE_STAT_INC(in_martian_src);
1492 #ifdef CONFIG_IP_ROUTE_VERBOSE
1493 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1494 /*
1495 * RFC1812 recommendation, if source is martian,
1496 * the only hint is MAC header.
1497 */
1498 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1499 &daddr, &saddr, dev->name);
1500 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1501 print_hex_dump(KERN_WARNING, "ll header: ",
1502 DUMP_PREFIX_OFFSET, 16, 1,
1503 skb_mac_header(skb),
1504 dev->hard_header_len, true);
1505 }
1506 }
1507 #endif
1508 }
1509
1510 /* called in rcu_read_lock() section */
1511 static int __mkroute_input(struct sk_buff *skb,
1512 const struct fib_result *res,
1513 struct in_device *in_dev,
1514 __be32 daddr, __be32 saddr, u32 tos)
1515 {
1516 struct fib_nh_exception *fnhe;
1517 struct rtable *rth;
1518 int err;
1519 struct in_device *out_dev;
1520 unsigned int flags = 0;
1521 bool do_cache;
1522 u32 itag;
1523
1524 /* get a working reference to the output device */
1525 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1526 if (out_dev == NULL) {
1527 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1528 return -EINVAL;
1529 }
1530
1531 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1532 in_dev->dev, in_dev, &itag);
1533 if (err < 0) {
1534 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1535 saddr);
1536
1537 goto cleanup;
1538 }
1539
1540 do_cache = res->fi && !itag;
1541 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1542 (IN_DEV_SHARED_MEDIA(out_dev) ||
1543 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) {
1544 flags |= RTCF_DOREDIRECT;
1545 do_cache = false;
1546 }
1547
1548 if (skb->protocol != htons(ETH_P_IP)) {
1549 /* Not IP (i.e. ARP). Do not create route, if it is
1550 * invalid for proxy arp. DNAT routes are always valid.
1551 *
1552 * Proxy arp feature have been extended to allow, ARP
1553 * replies back to the same interface, to support
1554 * Private VLAN switch technologies. See arp.c.
1555 */
1556 if (out_dev == in_dev &&
1557 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1558 err = -EINVAL;
1559 goto cleanup;
1560 }
1561 }
1562
1563 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1564 if (do_cache) {
1565 if (fnhe != NULL)
1566 rth = rcu_dereference(fnhe->fnhe_rth_input);
1567 else
1568 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1569
1570 if (rt_cache_valid(rth)) {
1571 skb_dst_set_noref(skb, &rth->dst);
1572 goto out;
1573 }
1574 }
1575
1576 rth = rt_dst_alloc(out_dev->dev,
1577 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1578 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1579 if (!rth) {
1580 err = -ENOBUFS;
1581 goto cleanup;
1582 }
1583
1584 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev));
1585 rth->rt_flags = flags;
1586 rth->rt_type = res->type;
1587 rth->rt_is_input = 1;
1588 rth->rt_iif = 0;
1589 rth->rt_pmtu = 0;
1590 rth->rt_gateway = 0;
1591 rth->rt_uses_gateway = 0;
1592 INIT_LIST_HEAD(&rth->rt_uncached);
1593 RT_CACHE_STAT_INC(in_slow_tot);
1594
1595 rth->dst.input = ip_forward;
1596 rth->dst.output = ip_output;
1597
1598 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1599 skb_dst_set(skb, &rth->dst);
1600 out:
1601 err = 0;
1602 cleanup:
1603 return err;
1604 }
1605
1606 static int ip_mkroute_input(struct sk_buff *skb,
1607 struct fib_result *res,
1608 const struct flowi4 *fl4,
1609 struct in_device *in_dev,
1610 __be32 daddr, __be32 saddr, u32 tos)
1611 {
1612 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1613 if (res->fi && res->fi->fib_nhs > 1)
1614 fib_select_multipath(res);
1615 #endif
1616
1617 /* create a routing cache entry */
1618 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1619 }
1620
1621 /*
1622 * NOTE. We drop all the packets that has local source
1623 * addresses, because every properly looped back packet
1624 * must have correct destination already attached by output routine.
1625 *
1626 * Such approach solves two big problems:
1627 * 1. Not simplex devices are handled properly.
1628 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1629 * called with rcu_read_lock()
1630 */
1631
1632 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1633 u8 tos, struct net_device *dev)
1634 {
1635 struct fib_result res;
1636 struct in_device *in_dev = __in_dev_get_rcu(dev);
1637 struct flowi4 fl4;
1638 unsigned int flags = 0;
1639 u32 itag = 0;
1640 struct rtable *rth;
1641 int err = -EINVAL;
1642 struct net *net = dev_net(dev);
1643 bool do_cache;
1644
1645 /* IP on this device is disabled. */
1646
1647 if (!in_dev)
1648 goto out;
1649
1650 /* Check for the most weird martians, which can be not detected
1651 by fib_lookup.
1652 */
1653
1654 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1655 goto martian_source;
1656
1657 res.fi = NULL;
1658 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1659 goto brd_input;
1660
1661 /* Accept zero addresses only to limited broadcast;
1662 * I even do not know to fix it or not. Waiting for complains :-)
1663 */
1664 if (ipv4_is_zeronet(saddr))
1665 goto martian_source;
1666
1667 if (ipv4_is_zeronet(daddr))
1668 goto martian_destination;
1669
1670 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1671 * and call it once if daddr or/and saddr are loopback addresses
1672 */
1673 if (ipv4_is_loopback(daddr)) {
1674 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1675 goto martian_destination;
1676 } else if (ipv4_is_loopback(saddr)) {
1677 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1678 goto martian_source;
1679 }
1680
1681 /*
1682 * Now we are ready to route packet.
1683 */
1684 fl4.flowi4_oif = 0;
1685 fl4.flowi4_iif = dev->ifindex;
1686 fl4.flowi4_mark = skb->mark;
1687 fl4.flowi4_tos = tos;
1688 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1689 fl4.daddr = daddr;
1690 fl4.saddr = saddr;
1691 err = fib_lookup(net, &fl4, &res);
1692 if (err != 0) {
1693 if (!IN_DEV_FORWARD(in_dev))
1694 err = -EHOSTUNREACH;
1695 goto no_route;
1696 }
1697
1698 if (res.type == RTN_BROADCAST)
1699 goto brd_input;
1700
1701 if (res.type == RTN_LOCAL) {
1702 err = fib_validate_source(skb, saddr, daddr, tos,
1703 0, dev, in_dev, &itag);
1704 if (err < 0)
1705 goto martian_source_keep_err;
1706 goto local_input;
1707 }
1708
1709 if (!IN_DEV_FORWARD(in_dev)) {
1710 err = -EHOSTUNREACH;
1711 goto no_route;
1712 }
1713 if (res.type != RTN_UNICAST)
1714 goto martian_destination;
1715
1716 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1717 out: return err;
1718
1719 brd_input:
1720 if (skb->protocol != htons(ETH_P_IP))
1721 goto e_inval;
1722
1723 if (!ipv4_is_zeronet(saddr)) {
1724 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1725 in_dev, &itag);
1726 if (err < 0)
1727 goto martian_source_keep_err;
1728 }
1729 flags |= RTCF_BROADCAST;
1730 res.type = RTN_BROADCAST;
1731 RT_CACHE_STAT_INC(in_brd);
1732
1733 local_input:
1734 do_cache = false;
1735 if (res.fi) {
1736 if (!itag) {
1737 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1738 if (rt_cache_valid(rth)) {
1739 skb_dst_set_noref(skb, &rth->dst);
1740 err = 0;
1741 goto out;
1742 }
1743 do_cache = true;
1744 }
1745 }
1746
1747 rth = rt_dst_alloc(net->loopback_dev,
1748 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1749 if (!rth)
1750 goto e_nobufs;
1751
1752 rth->dst.input= ip_local_deliver;
1753 rth->dst.output= ip_rt_bug;
1754 #ifdef CONFIG_IP_ROUTE_CLASSID
1755 rth->dst.tclassid = itag;
1756 #endif
1757
1758 rth->rt_genid = rt_genid_ipv4(net);
1759 rth->rt_flags = flags|RTCF_LOCAL;
1760 rth->rt_type = res.type;
1761 rth->rt_is_input = 1;
1762 rth->rt_iif = 0;
1763 rth->rt_pmtu = 0;
1764 rth->rt_gateway = 0;
1765 rth->rt_uses_gateway = 0;
1766 INIT_LIST_HEAD(&rth->rt_uncached);
1767 RT_CACHE_STAT_INC(in_slow_tot);
1768 if (res.type == RTN_UNREACHABLE) {
1769 rth->dst.input= ip_error;
1770 rth->dst.error= -err;
1771 rth->rt_flags &= ~RTCF_LOCAL;
1772 }
1773 if (do_cache) {
1774 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1775 rth->dst.flags |= DST_NOCACHE;
1776 rt_add_uncached_list(rth);
1777 }
1778 }
1779 skb_dst_set(skb, &rth->dst);
1780 err = 0;
1781 goto out;
1782
1783 no_route:
1784 RT_CACHE_STAT_INC(in_no_route);
1785 res.type = RTN_UNREACHABLE;
1786 if (err == -ESRCH)
1787 err = -ENETUNREACH;
1788 goto local_input;
1789
1790 /*
1791 * Do not cache martian addresses: they should be logged (RFC1812)
1792 */
1793 martian_destination:
1794 RT_CACHE_STAT_INC(in_martian_dst);
1795 #ifdef CONFIG_IP_ROUTE_VERBOSE
1796 if (IN_DEV_LOG_MARTIANS(in_dev))
1797 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1798 &daddr, &saddr, dev->name);
1799 #endif
1800
1801 e_inval:
1802 err = -EINVAL;
1803 goto out;
1804
1805 e_nobufs:
1806 err = -ENOBUFS;
1807 goto out;
1808
1809 martian_source:
1810 err = -EINVAL;
1811 martian_source_keep_err:
1812 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1813 goto out;
1814 }
1815
1816 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1817 u8 tos, struct net_device *dev)
1818 {
1819 int res;
1820
1821 rcu_read_lock();
1822
1823 /* Multicast recognition logic is moved from route cache to here.
1824 The problem was that too many Ethernet cards have broken/missing
1825 hardware multicast filters :-( As result the host on multicasting
1826 network acquires a lot of useless route cache entries, sort of
1827 SDR messages from all the world. Now we try to get rid of them.
1828 Really, provided software IP multicast filter is organized
1829 reasonably (at least, hashed), it does not result in a slowdown
1830 comparing with route cache reject entries.
1831 Note, that multicast routers are not affected, because
1832 route cache entry is created eventually.
1833 */
1834 if (ipv4_is_multicast(daddr)) {
1835 struct in_device *in_dev = __in_dev_get_rcu(dev);
1836
1837 if (in_dev) {
1838 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1839 ip_hdr(skb)->protocol);
1840 if (our
1841 #ifdef CONFIG_IP_MROUTE
1842 ||
1843 (!ipv4_is_local_multicast(daddr) &&
1844 IN_DEV_MFORWARD(in_dev))
1845 #endif
1846 ) {
1847 int res = ip_route_input_mc(skb, daddr, saddr,
1848 tos, dev, our);
1849 rcu_read_unlock();
1850 return res;
1851 }
1852 }
1853 rcu_read_unlock();
1854 return -EINVAL;
1855 }
1856 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1857 rcu_read_unlock();
1858 return res;
1859 }
1860 EXPORT_SYMBOL(ip_route_input_noref);
1861
1862 /* called with rcu_read_lock() */
1863 static struct rtable *__mkroute_output(const struct fib_result *res,
1864 const struct flowi4 *fl4, int orig_oif,
1865 struct net_device *dev_out,
1866 unsigned int flags)
1867 {
1868 struct fib_info *fi = res->fi;
1869 struct fib_nh_exception *fnhe;
1870 struct in_device *in_dev;
1871 u16 type = res->type;
1872 struct rtable *rth;
1873 bool do_cache;
1874
1875 in_dev = __in_dev_get_rcu(dev_out);
1876 if (!in_dev)
1877 return ERR_PTR(-EINVAL);
1878
1879 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1880 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1881 return ERR_PTR(-EINVAL);
1882
1883 if (ipv4_is_lbcast(fl4->daddr))
1884 type = RTN_BROADCAST;
1885 else if (ipv4_is_multicast(fl4->daddr))
1886 type = RTN_MULTICAST;
1887 else if (ipv4_is_zeronet(fl4->daddr))
1888 return ERR_PTR(-EINVAL);
1889
1890 if (dev_out->flags & IFF_LOOPBACK)
1891 flags |= RTCF_LOCAL;
1892
1893 do_cache = true;
1894 if (type == RTN_BROADCAST) {
1895 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1896 fi = NULL;
1897 } else if (type == RTN_MULTICAST) {
1898 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1899 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1900 fl4->flowi4_proto))
1901 flags &= ~RTCF_LOCAL;
1902 else
1903 do_cache = false;
1904 /* If multicast route do not exist use
1905 * default one, but do not gateway in this case.
1906 * Yes, it is hack.
1907 */
1908 if (fi && res->prefixlen < 4)
1909 fi = NULL;
1910 }
1911
1912 fnhe = NULL;
1913 do_cache &= fi != NULL;
1914 if (do_cache) {
1915 struct rtable __rcu **prth;
1916 struct fib_nh *nh = &FIB_RES_NH(*res);
1917
1918 fnhe = find_exception(nh, fl4->daddr);
1919 if (fnhe)
1920 prth = &fnhe->fnhe_rth_output;
1921 else {
1922 if (unlikely(fl4->flowi4_flags &
1923 FLOWI_FLAG_KNOWN_NH &&
1924 !(nh->nh_gw &&
1925 nh->nh_scope == RT_SCOPE_LINK))) {
1926 do_cache = false;
1927 goto add;
1928 }
1929 prth = __this_cpu_ptr(nh->nh_pcpu_rth_output);
1930 }
1931 rth = rcu_dereference(*prth);
1932 if (rt_cache_valid(rth)) {
1933 dst_hold(&rth->dst);
1934 return rth;
1935 }
1936 }
1937
1938 add:
1939 rth = rt_dst_alloc(dev_out,
1940 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1941 IN_DEV_CONF_GET(in_dev, NOXFRM),
1942 do_cache);
1943 if (!rth)
1944 return ERR_PTR(-ENOBUFS);
1945
1946 rth->dst.output = ip_output;
1947
1948 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out));
1949 rth->rt_flags = flags;
1950 rth->rt_type = type;
1951 rth->rt_is_input = 0;
1952 rth->rt_iif = orig_oif ? : 0;
1953 rth->rt_pmtu = 0;
1954 rth->rt_gateway = 0;
1955 rth->rt_uses_gateway = 0;
1956 INIT_LIST_HEAD(&rth->rt_uncached);
1957
1958 RT_CACHE_STAT_INC(out_slow_tot);
1959
1960 if (flags & RTCF_LOCAL)
1961 rth->dst.input = ip_local_deliver;
1962 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1963 if (flags & RTCF_LOCAL &&
1964 !(dev_out->flags & IFF_LOOPBACK)) {
1965 rth->dst.output = ip_mc_output;
1966 RT_CACHE_STAT_INC(out_slow_mc);
1967 }
1968 #ifdef CONFIG_IP_MROUTE
1969 if (type == RTN_MULTICAST) {
1970 if (IN_DEV_MFORWARD(in_dev) &&
1971 !ipv4_is_local_multicast(fl4->daddr)) {
1972 rth->dst.input = ip_mr_input;
1973 rth->dst.output = ip_mc_output;
1974 }
1975 }
1976 #endif
1977 }
1978
1979 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1980
1981 return rth;
1982 }
1983
1984 /*
1985 * Major route resolver routine.
1986 */
1987
1988 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1989 {
1990 struct net_device *dev_out = NULL;
1991 __u8 tos = RT_FL_TOS(fl4);
1992 unsigned int flags = 0;
1993 struct fib_result res;
1994 struct rtable *rth;
1995 int orig_oif;
1996
1997 res.tclassid = 0;
1998 res.fi = NULL;
1999 res.table = NULL;
2000
2001 orig_oif = fl4->flowi4_oif;
2002
2003 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2004 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2005 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2006 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2007
2008 rcu_read_lock();
2009 if (fl4->saddr) {
2010 rth = ERR_PTR(-EINVAL);
2011 if (ipv4_is_multicast(fl4->saddr) ||
2012 ipv4_is_lbcast(fl4->saddr) ||
2013 ipv4_is_zeronet(fl4->saddr))
2014 goto out;
2015
2016 /* I removed check for oif == dev_out->oif here.
2017 It was wrong for two reasons:
2018 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2019 is assigned to multiple interfaces.
2020 2. Moreover, we are allowed to send packets with saddr
2021 of another iface. --ANK
2022 */
2023
2024 if (fl4->flowi4_oif == 0 &&
2025 (ipv4_is_multicast(fl4->daddr) ||
2026 ipv4_is_lbcast(fl4->daddr))) {
2027 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2028 dev_out = __ip_dev_find(net, fl4->saddr, false);
2029 if (dev_out == NULL)
2030 goto out;
2031
2032 /* Special hack: user can direct multicasts
2033 and limited broadcast via necessary interface
2034 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2035 This hack is not just for fun, it allows
2036 vic,vat and friends to work.
2037 They bind socket to loopback, set ttl to zero
2038 and expect that it will work.
2039 From the viewpoint of routing cache they are broken,
2040 because we are not allowed to build multicast path
2041 with loopback source addr (look, routing cache
2042 cannot know, that ttl is zero, so that packet
2043 will not leave this host and route is valid).
2044 Luckily, this hack is good workaround.
2045 */
2046
2047 fl4->flowi4_oif = dev_out->ifindex;
2048 goto make_route;
2049 }
2050
2051 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2052 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2053 if (!__ip_dev_find(net, fl4->saddr, false))
2054 goto out;
2055 }
2056 }
2057
2058
2059 if (fl4->flowi4_oif) {
2060 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2061 rth = ERR_PTR(-ENODEV);
2062 if (dev_out == NULL)
2063 goto out;
2064
2065 /* RACE: Check return value of inet_select_addr instead. */
2066 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2067 rth = ERR_PTR(-ENETUNREACH);
2068 goto out;
2069 }
2070 if (ipv4_is_local_multicast(fl4->daddr) ||
2071 ipv4_is_lbcast(fl4->daddr)) {
2072 if (!fl4->saddr)
2073 fl4->saddr = inet_select_addr(dev_out, 0,
2074 RT_SCOPE_LINK);
2075 goto make_route;
2076 }
2077 if (!fl4->saddr) {
2078 if (ipv4_is_multicast(fl4->daddr))
2079 fl4->saddr = inet_select_addr(dev_out, 0,
2080 fl4->flowi4_scope);
2081 else if (!fl4->daddr)
2082 fl4->saddr = inet_select_addr(dev_out, 0,
2083 RT_SCOPE_HOST);
2084 }
2085 }
2086
2087 if (!fl4->daddr) {
2088 fl4->daddr = fl4->saddr;
2089 if (!fl4->daddr)
2090 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2091 dev_out = net->loopback_dev;
2092 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2093 res.type = RTN_LOCAL;
2094 flags |= RTCF_LOCAL;
2095 goto make_route;
2096 }
2097
2098 if (fib_lookup(net, fl4, &res)) {
2099 res.fi = NULL;
2100 res.table = NULL;
2101 if (fl4->flowi4_oif) {
2102 /* Apparently, routing tables are wrong. Assume,
2103 that the destination is on link.
2104
2105 WHY? DW.
2106 Because we are allowed to send to iface
2107 even if it has NO routes and NO assigned
2108 addresses. When oif is specified, routing
2109 tables are looked up with only one purpose:
2110 to catch if destination is gatewayed, rather than
2111 direct. Moreover, if MSG_DONTROUTE is set,
2112 we send packet, ignoring both routing tables
2113 and ifaddr state. --ANK
2114
2115
2116 We could make it even if oif is unknown,
2117 likely IPv6, but we do not.
2118 */
2119
2120 if (fl4->saddr == 0)
2121 fl4->saddr = inet_select_addr(dev_out, 0,
2122 RT_SCOPE_LINK);
2123 res.type = RTN_UNICAST;
2124 goto make_route;
2125 }
2126 rth = ERR_PTR(-ENETUNREACH);
2127 goto out;
2128 }
2129
2130 if (res.type == RTN_LOCAL) {
2131 if (!fl4->saddr) {
2132 if (res.fi->fib_prefsrc)
2133 fl4->saddr = res.fi->fib_prefsrc;
2134 else
2135 fl4->saddr = fl4->daddr;
2136 }
2137 dev_out = net->loopback_dev;
2138 fl4->flowi4_oif = dev_out->ifindex;
2139 flags |= RTCF_LOCAL;
2140 goto make_route;
2141 }
2142
2143 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2144 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2145 fib_select_multipath(&res);
2146 else
2147 #endif
2148 if (!res.prefixlen &&
2149 res.table->tb_num_default > 1 &&
2150 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2151 fib_select_default(&res);
2152
2153 if (!fl4->saddr)
2154 fl4->saddr = FIB_RES_PREFSRC(net, res);
2155
2156 dev_out = FIB_RES_DEV(res);
2157 fl4->flowi4_oif = dev_out->ifindex;
2158
2159
2160 make_route:
2161 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2162
2163 out:
2164 rcu_read_unlock();
2165 return rth;
2166 }
2167 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2168
2169 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2170 {
2171 return NULL;
2172 }
2173
2174 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2175 {
2176 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2177
2178 return mtu ? : dst->dev->mtu;
2179 }
2180
2181 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2182 struct sk_buff *skb, u32 mtu)
2183 {
2184 }
2185
2186 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2187 struct sk_buff *skb)
2188 {
2189 }
2190
2191 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2192 unsigned long old)
2193 {
2194 return NULL;
2195 }
2196
2197 static struct dst_ops ipv4_dst_blackhole_ops = {
2198 .family = AF_INET,
2199 .protocol = cpu_to_be16(ETH_P_IP),
2200 .check = ipv4_blackhole_dst_check,
2201 .mtu = ipv4_blackhole_mtu,
2202 .default_advmss = ipv4_default_advmss,
2203 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2204 .redirect = ipv4_rt_blackhole_redirect,
2205 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2206 .neigh_lookup = ipv4_neigh_lookup,
2207 };
2208
2209 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2210 {
2211 struct rtable *ort = (struct rtable *) dst_orig;
2212 struct rtable *rt;
2213
2214 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2215 if (rt) {
2216 struct dst_entry *new = &rt->dst;
2217
2218 new->__use = 1;
2219 new->input = dst_discard;
2220 new->output = dst_discard_sk;
2221
2222 new->dev = ort->dst.dev;
2223 if (new->dev)
2224 dev_hold(new->dev);
2225
2226 rt->rt_is_input = ort->rt_is_input;
2227 rt->rt_iif = ort->rt_iif;
2228 rt->rt_pmtu = ort->rt_pmtu;
2229
2230 rt->rt_genid = rt_genid_ipv4(net);
2231 rt->rt_flags = ort->rt_flags;
2232 rt->rt_type = ort->rt_type;
2233 rt->rt_gateway = ort->rt_gateway;
2234 rt->rt_uses_gateway = ort->rt_uses_gateway;
2235
2236 INIT_LIST_HEAD(&rt->rt_uncached);
2237
2238 dst_free(new);
2239 }
2240
2241 dst_release(dst_orig);
2242
2243 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2244 }
2245
2246 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2247 struct sock *sk)
2248 {
2249 struct rtable *rt = __ip_route_output_key(net, flp4);
2250
2251 if (IS_ERR(rt))
2252 return rt;
2253
2254 if (flp4->flowi4_proto)
2255 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2256 flowi4_to_flowi(flp4),
2257 sk, 0);
2258
2259 return rt;
2260 }
2261 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2262
2263 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2264 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2265 u32 seq, int event, int nowait, unsigned int flags)
2266 {
2267 struct rtable *rt = skb_rtable(skb);
2268 struct rtmsg *r;
2269 struct nlmsghdr *nlh;
2270 unsigned long expires = 0;
2271 u32 error;
2272 u32 metrics[RTAX_MAX];
2273
2274 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2275 if (nlh == NULL)
2276 return -EMSGSIZE;
2277
2278 r = nlmsg_data(nlh);
2279 r->rtm_family = AF_INET;
2280 r->rtm_dst_len = 32;
2281 r->rtm_src_len = 0;
2282 r->rtm_tos = fl4->flowi4_tos;
2283 r->rtm_table = RT_TABLE_MAIN;
2284 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2285 goto nla_put_failure;
2286 r->rtm_type = rt->rt_type;
2287 r->rtm_scope = RT_SCOPE_UNIVERSE;
2288 r->rtm_protocol = RTPROT_UNSPEC;
2289 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2290 if (rt->rt_flags & RTCF_NOTIFY)
2291 r->rtm_flags |= RTM_F_NOTIFY;
2292
2293 if (nla_put_be32(skb, RTA_DST, dst))
2294 goto nla_put_failure;
2295 if (src) {
2296 r->rtm_src_len = 32;
2297 if (nla_put_be32(skb, RTA_SRC, src))
2298 goto nla_put_failure;
2299 }
2300 if (rt->dst.dev &&
2301 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2302 goto nla_put_failure;
2303 #ifdef CONFIG_IP_ROUTE_CLASSID
2304 if (rt->dst.tclassid &&
2305 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2306 goto nla_put_failure;
2307 #endif
2308 if (!rt_is_input_route(rt) &&
2309 fl4->saddr != src) {
2310 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2311 goto nla_put_failure;
2312 }
2313 if (rt->rt_uses_gateway &&
2314 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2315 goto nla_put_failure;
2316
2317 expires = rt->dst.expires;
2318 if (expires) {
2319 unsigned long now = jiffies;
2320
2321 if (time_before(now, expires))
2322 expires -= now;
2323 else
2324 expires = 0;
2325 }
2326
2327 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2328 if (rt->rt_pmtu && expires)
2329 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2330 if (rtnetlink_put_metrics(skb, metrics) < 0)
2331 goto nla_put_failure;
2332
2333 if (fl4->flowi4_mark &&
2334 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2335 goto nla_put_failure;
2336
2337 error = rt->dst.error;
2338
2339 if (rt_is_input_route(rt)) {
2340 #ifdef CONFIG_IP_MROUTE
2341 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2342 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2343 int err = ipmr_get_route(net, skb,
2344 fl4->saddr, fl4->daddr,
2345 r, nowait);
2346 if (err <= 0) {
2347 if (!nowait) {
2348 if (err == 0)
2349 return 0;
2350 goto nla_put_failure;
2351 } else {
2352 if (err == -EMSGSIZE)
2353 goto nla_put_failure;
2354 error = err;
2355 }
2356 }
2357 } else
2358 #endif
2359 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2360 goto nla_put_failure;
2361 }
2362
2363 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2364 goto nla_put_failure;
2365
2366 return nlmsg_end(skb, nlh);
2367
2368 nla_put_failure:
2369 nlmsg_cancel(skb, nlh);
2370 return -EMSGSIZE;
2371 }
2372
2373 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2374 {
2375 struct net *net = sock_net(in_skb->sk);
2376 struct rtmsg *rtm;
2377 struct nlattr *tb[RTA_MAX+1];
2378 struct rtable *rt = NULL;
2379 struct flowi4 fl4;
2380 __be32 dst = 0;
2381 __be32 src = 0;
2382 u32 iif;
2383 int err;
2384 int mark;
2385 struct sk_buff *skb;
2386
2387 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2388 if (err < 0)
2389 goto errout;
2390
2391 rtm = nlmsg_data(nlh);
2392
2393 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2394 if (skb == NULL) {
2395 err = -ENOBUFS;
2396 goto errout;
2397 }
2398
2399 /* Reserve room for dummy headers, this skb can pass
2400 through good chunk of routing engine.
2401 */
2402 skb_reset_mac_header(skb);
2403 skb_reset_network_header(skb);
2404
2405 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2406 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2407 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2408
2409 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2410 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2411 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2412 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2413
2414 memset(&fl4, 0, sizeof(fl4));
2415 fl4.daddr = dst;
2416 fl4.saddr = src;
2417 fl4.flowi4_tos = rtm->rtm_tos;
2418 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2419 fl4.flowi4_mark = mark;
2420
2421 if (iif) {
2422 struct net_device *dev;
2423
2424 dev = __dev_get_by_index(net, iif);
2425 if (dev == NULL) {
2426 err = -ENODEV;
2427 goto errout_free;
2428 }
2429
2430 skb->protocol = htons(ETH_P_IP);
2431 skb->dev = dev;
2432 skb->mark = mark;
2433 local_bh_disable();
2434 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2435 local_bh_enable();
2436
2437 rt = skb_rtable(skb);
2438 if (err == 0 && rt->dst.error)
2439 err = -rt->dst.error;
2440 } else {
2441 rt = ip_route_output_key(net, &fl4);
2442
2443 err = 0;
2444 if (IS_ERR(rt))
2445 err = PTR_ERR(rt);
2446 }
2447
2448 if (err)
2449 goto errout_free;
2450
2451 skb_dst_set(skb, &rt->dst);
2452 if (rtm->rtm_flags & RTM_F_NOTIFY)
2453 rt->rt_flags |= RTCF_NOTIFY;
2454
2455 err = rt_fill_info(net, dst, src, &fl4, skb,
2456 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2457 RTM_NEWROUTE, 0, 0);
2458 if (err <= 0)
2459 goto errout_free;
2460
2461 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2462 errout:
2463 return err;
2464
2465 errout_free:
2466 kfree_skb(skb);
2467 goto errout;
2468 }
2469
2470 void ip_rt_multicast_event(struct in_device *in_dev)
2471 {
2472 rt_cache_flush(dev_net(in_dev->dev));
2473 }
2474
2475 #ifdef CONFIG_SYSCTL
2476 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2477 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2478 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2479 static int ip_rt_gc_elasticity __read_mostly = 8;
2480
2481 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2482 void __user *buffer,
2483 size_t *lenp, loff_t *ppos)
2484 {
2485 struct net *net = (struct net *)__ctl->extra1;
2486
2487 if (write) {
2488 rt_cache_flush(net);
2489 fnhe_genid_bump(net);
2490 return 0;
2491 }
2492
2493 return -EINVAL;
2494 }
2495
2496 static struct ctl_table ipv4_route_table[] = {
2497 {
2498 .procname = "gc_thresh",
2499 .data = &ipv4_dst_ops.gc_thresh,
2500 .maxlen = sizeof(int),
2501 .mode = 0644,
2502 .proc_handler = proc_dointvec,
2503 },
2504 {
2505 .procname = "max_size",
2506 .data = &ip_rt_max_size,
2507 .maxlen = sizeof(int),
2508 .mode = 0644,
2509 .proc_handler = proc_dointvec,
2510 },
2511 {
2512 /* Deprecated. Use gc_min_interval_ms */
2513
2514 .procname = "gc_min_interval",
2515 .data = &ip_rt_gc_min_interval,
2516 .maxlen = sizeof(int),
2517 .mode = 0644,
2518 .proc_handler = proc_dointvec_jiffies,
2519 },
2520 {
2521 .procname = "gc_min_interval_ms",
2522 .data = &ip_rt_gc_min_interval,
2523 .maxlen = sizeof(int),
2524 .mode = 0644,
2525 .proc_handler = proc_dointvec_ms_jiffies,
2526 },
2527 {
2528 .procname = "gc_timeout",
2529 .data = &ip_rt_gc_timeout,
2530 .maxlen = sizeof(int),
2531 .mode = 0644,
2532 .proc_handler = proc_dointvec_jiffies,
2533 },
2534 {
2535 .procname = "gc_interval",
2536 .data = &ip_rt_gc_interval,
2537 .maxlen = sizeof(int),
2538 .mode = 0644,
2539 .proc_handler = proc_dointvec_jiffies,
2540 },
2541 {
2542 .procname = "redirect_load",
2543 .data = &ip_rt_redirect_load,
2544 .maxlen = sizeof(int),
2545 .mode = 0644,
2546 .proc_handler = proc_dointvec,
2547 },
2548 {
2549 .procname = "redirect_number",
2550 .data = &ip_rt_redirect_number,
2551 .maxlen = sizeof(int),
2552 .mode = 0644,
2553 .proc_handler = proc_dointvec,
2554 },
2555 {
2556 .procname = "redirect_silence",
2557 .data = &ip_rt_redirect_silence,
2558 .maxlen = sizeof(int),
2559 .mode = 0644,
2560 .proc_handler = proc_dointvec,
2561 },
2562 {
2563 .procname = "error_cost",
2564 .data = &ip_rt_error_cost,
2565 .maxlen = sizeof(int),
2566 .mode = 0644,
2567 .proc_handler = proc_dointvec,
2568 },
2569 {
2570 .procname = "error_burst",
2571 .data = &ip_rt_error_burst,
2572 .maxlen = sizeof(int),
2573 .mode = 0644,
2574 .proc_handler = proc_dointvec,
2575 },
2576 {
2577 .procname = "gc_elasticity",
2578 .data = &ip_rt_gc_elasticity,
2579 .maxlen = sizeof(int),
2580 .mode = 0644,
2581 .proc_handler = proc_dointvec,
2582 },
2583 {
2584 .procname = "mtu_expires",
2585 .data = &ip_rt_mtu_expires,
2586 .maxlen = sizeof(int),
2587 .mode = 0644,
2588 .proc_handler = proc_dointvec_jiffies,
2589 },
2590 {
2591 .procname = "min_pmtu",
2592 .data = &ip_rt_min_pmtu,
2593 .maxlen = sizeof(int),
2594 .mode = 0644,
2595 .proc_handler = proc_dointvec,
2596 },
2597 {
2598 .procname = "min_adv_mss",
2599 .data = &ip_rt_min_advmss,
2600 .maxlen = sizeof(int),
2601 .mode = 0644,
2602 .proc_handler = proc_dointvec,
2603 },
2604 { }
2605 };
2606
2607 static struct ctl_table ipv4_route_flush_table[] = {
2608 {
2609 .procname = "flush",
2610 .maxlen = sizeof(int),
2611 .mode = 0200,
2612 .proc_handler = ipv4_sysctl_rtcache_flush,
2613 },
2614 { },
2615 };
2616
2617 static __net_init int sysctl_route_net_init(struct net *net)
2618 {
2619 struct ctl_table *tbl;
2620
2621 tbl = ipv4_route_flush_table;
2622 if (!net_eq(net, &init_net)) {
2623 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2624 if (tbl == NULL)
2625 goto err_dup;
2626
2627 /* Don't export sysctls to unprivileged users */
2628 if (net->user_ns != &init_user_ns)
2629 tbl[0].procname = NULL;
2630 }
2631 tbl[0].extra1 = net;
2632
2633 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2634 if (net->ipv4.route_hdr == NULL)
2635 goto err_reg;
2636 return 0;
2637
2638 err_reg:
2639 if (tbl != ipv4_route_flush_table)
2640 kfree(tbl);
2641 err_dup:
2642 return -ENOMEM;
2643 }
2644
2645 static __net_exit void sysctl_route_net_exit(struct net *net)
2646 {
2647 struct ctl_table *tbl;
2648
2649 tbl = net->ipv4.route_hdr->ctl_table_arg;
2650 unregister_net_sysctl_table(net->ipv4.route_hdr);
2651 BUG_ON(tbl == ipv4_route_flush_table);
2652 kfree(tbl);
2653 }
2654
2655 static __net_initdata struct pernet_operations sysctl_route_ops = {
2656 .init = sysctl_route_net_init,
2657 .exit = sysctl_route_net_exit,
2658 };
2659 #endif
2660
2661 static __net_init int rt_genid_init(struct net *net)
2662 {
2663 atomic_set(&net->ipv4.rt_genid, 0);
2664 atomic_set(&net->fnhe_genid, 0);
2665 get_random_bytes(&net->ipv4.dev_addr_genid,
2666 sizeof(net->ipv4.dev_addr_genid));
2667 return 0;
2668 }
2669
2670 static __net_initdata struct pernet_operations rt_genid_ops = {
2671 .init = rt_genid_init,
2672 };
2673
2674 static int __net_init ipv4_inetpeer_init(struct net *net)
2675 {
2676 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2677
2678 if (!bp)
2679 return -ENOMEM;
2680 inet_peer_base_init(bp);
2681 net->ipv4.peers = bp;
2682 return 0;
2683 }
2684
2685 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2686 {
2687 struct inet_peer_base *bp = net->ipv4.peers;
2688
2689 net->ipv4.peers = NULL;
2690 inetpeer_invalidate_tree(bp);
2691 kfree(bp);
2692 }
2693
2694 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2695 .init = ipv4_inetpeer_init,
2696 .exit = ipv4_inetpeer_exit,
2697 };
2698
2699 #ifdef CONFIG_IP_ROUTE_CLASSID
2700 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2701 #endif /* CONFIG_IP_ROUTE_CLASSID */
2702
2703 int __init ip_rt_init(void)
2704 {
2705 int rc = 0;
2706
2707 #ifdef CONFIG_IP_ROUTE_CLASSID
2708 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2709 if (!ip_rt_acct)
2710 panic("IP: failed to allocate ip_rt_acct\n");
2711 #endif
2712
2713 ipv4_dst_ops.kmem_cachep =
2714 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2715 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2716
2717 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2718
2719 if (dst_entries_init(&ipv4_dst_ops) < 0)
2720 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2721
2722 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2723 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2724
2725 ipv4_dst_ops.gc_thresh = ~0;
2726 ip_rt_max_size = INT_MAX;
2727
2728 devinet_init();
2729 ip_fib_init();
2730
2731 if (ip_rt_proc_init())
2732 pr_err("Unable to create route proc files\n");
2733 #ifdef CONFIG_XFRM
2734 xfrm_init();
2735 xfrm4_init();
2736 #endif
2737 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2738
2739 #ifdef CONFIG_SYSCTL
2740 register_pernet_subsys(&sysctl_route_ops);
2741 #endif
2742 register_pernet_subsys(&rt_genid_ops);
2743 register_pernet_subsys(&ipv4_inetpeer_ops);
2744 return rc;
2745 }
2746
2747 #ifdef CONFIG_SYSCTL
2748 /*
2749 * We really need to sanitize the damn ipv4 init order, then all
2750 * this nonsense will go away.
2751 */
2752 void __init ip_static_sysctl_init(void)
2753 {
2754 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2755 }
2756 #endif
Linux kernel - Deliverables
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