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netlink: Fix bugs in nlmsg_end() conversions.
[deliverable/linux.git] / net / ipv4 / route.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65 #define pr_fmt(fmt) "IPv4: " fmt
66
67 #include <linux/module.h>
68 #include <asm/uaccess.h>
69 #include <linux/bitops.h>
70 #include <linux/types.h>
71 #include <linux/kernel.h>
72 #include <linux/mm.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
77 #include <linux/in.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/skbuff.h>
83 #include <linux/inetdevice.h>
84 #include <linux/igmp.h>
85 #include <linux/pkt_sched.h>
86 #include <linux/mroute.h>
87 #include <linux/netfilter_ipv4.h>
88 #include <linux/random.h>
89 #include <linux/rcupdate.h>
90 #include <linux/times.h>
91 #include <linux/slab.h>
92 #include <linux/jhash.h>
93 #include <net/dst.h>
94 #include <net/net_namespace.h>
95 #include <net/protocol.h>
96 #include <net/ip.h>
97 #include <net/route.h>
98 #include <net/inetpeer.h>
99 #include <net/sock.h>
100 #include <net/ip_fib.h>
101 #include <net/arp.h>
102 #include <net/tcp.h>
103 #include <net/icmp.h>
104 #include <net/xfrm.h>
105 #include <net/netevent.h>
106 #include <net/rtnetlink.h>
107 #ifdef CONFIG_SYSCTL
108 #include <linux/sysctl.h>
109 #include <linux/kmemleak.h>
110 #endif
111 #include <net/secure_seq.h>
112
113 #define RT_FL_TOS(oldflp4) \
114 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
115
116 #define RT_GC_TIMEOUT (300*HZ)
117
118 static int ip_rt_max_size;
119 static int ip_rt_redirect_number __read_mostly = 9;
120 static int ip_rt_redirect_load __read_mostly = HZ / 50;
121 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
122 static int ip_rt_error_cost __read_mostly = HZ;
123 static int ip_rt_error_burst __read_mostly = 5 * HZ;
124 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
125 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
126 static int ip_rt_min_advmss __read_mostly = 256;
127
128 /*
129 * Interface to generic destination cache.
130 */
131
132 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
133 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
134 static unsigned int ipv4_mtu(const struct dst_entry *dst);
135 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
136 static void ipv4_link_failure(struct sk_buff *skb);
137 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
138 struct sk_buff *skb, u32 mtu);
139 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
140 struct sk_buff *skb);
141 static void ipv4_dst_destroy(struct dst_entry *dst);
142
143 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
144 {
145 WARN_ON(1);
146 return NULL;
147 }
148
149 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
150 struct sk_buff *skb,
151 const void *daddr);
152
153 static struct dst_ops ipv4_dst_ops = {
154 .family = AF_INET,
155 .protocol = cpu_to_be16(ETH_P_IP),
156 .check = ipv4_dst_check,
157 .default_advmss = ipv4_default_advmss,
158 .mtu = ipv4_mtu,
159 .cow_metrics = ipv4_cow_metrics,
160 .destroy = ipv4_dst_destroy,
161 .negative_advice = ipv4_negative_advice,
162 .link_failure = ipv4_link_failure,
163 .update_pmtu = ip_rt_update_pmtu,
164 .redirect = ip_do_redirect,
165 .local_out = __ip_local_out,
166 .neigh_lookup = ipv4_neigh_lookup,
167 };
168
169 #define ECN_OR_COST(class) TC_PRIO_##class
170
171 const __u8 ip_tos2prio[16] = {
172 TC_PRIO_BESTEFFORT,
173 ECN_OR_COST(BESTEFFORT),
174 TC_PRIO_BESTEFFORT,
175 ECN_OR_COST(BESTEFFORT),
176 TC_PRIO_BULK,
177 ECN_OR_COST(BULK),
178 TC_PRIO_BULK,
179 ECN_OR_COST(BULK),
180 TC_PRIO_INTERACTIVE,
181 ECN_OR_COST(INTERACTIVE),
182 TC_PRIO_INTERACTIVE,
183 ECN_OR_COST(INTERACTIVE),
184 TC_PRIO_INTERACTIVE_BULK,
185 ECN_OR_COST(INTERACTIVE_BULK),
186 TC_PRIO_INTERACTIVE_BULK,
187 ECN_OR_COST(INTERACTIVE_BULK)
188 };
189 EXPORT_SYMBOL(ip_tos2prio);
190
191 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
192 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
193
194 #ifdef CONFIG_PROC_FS
195 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
196 {
197 if (*pos)
198 return NULL;
199 return SEQ_START_TOKEN;
200 }
201
202 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
203 {
204 ++*pos;
205 return NULL;
206 }
207
208 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
209 {
210 }
211
212 static int rt_cache_seq_show(struct seq_file *seq, void *v)
213 {
214 if (v == SEQ_START_TOKEN)
215 seq_printf(seq, "%-127s\n",
216 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
217 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
218 "HHUptod\tSpecDst");
219 return 0;
220 }
221
222 static const struct seq_operations rt_cache_seq_ops = {
223 .start = rt_cache_seq_start,
224 .next = rt_cache_seq_next,
225 .stop = rt_cache_seq_stop,
226 .show = rt_cache_seq_show,
227 };
228
229 static int rt_cache_seq_open(struct inode *inode, struct file *file)
230 {
231 return seq_open(file, &rt_cache_seq_ops);
232 }
233
234 static const struct file_operations rt_cache_seq_fops = {
235 .owner = THIS_MODULE,
236 .open = rt_cache_seq_open,
237 .read = seq_read,
238 .llseek = seq_lseek,
239 .release = seq_release,
240 };
241
242
243 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
244 {
245 int cpu;
246
247 if (*pos == 0)
248 return SEQ_START_TOKEN;
249
250 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
251 if (!cpu_possible(cpu))
252 continue;
253 *pos = cpu+1;
254 return &per_cpu(rt_cache_stat, cpu);
255 }
256 return NULL;
257 }
258
259 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
260 {
261 int cpu;
262
263 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
264 if (!cpu_possible(cpu))
265 continue;
266 *pos = cpu+1;
267 return &per_cpu(rt_cache_stat, cpu);
268 }
269 return NULL;
270
271 }
272
273 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
274 {
275
276 }
277
278 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
279 {
280 struct rt_cache_stat *st = v;
281
282 if (v == SEQ_START_TOKEN) {
283 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
284 return 0;
285 }
286
287 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
288 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
289 dst_entries_get_slow(&ipv4_dst_ops),
290 0, /* st->in_hit */
291 st->in_slow_tot,
292 st->in_slow_mc,
293 st->in_no_route,
294 st->in_brd,
295 st->in_martian_dst,
296 st->in_martian_src,
297
298 0, /* st->out_hit */
299 st->out_slow_tot,
300 st->out_slow_mc,
301
302 0, /* st->gc_total */
303 0, /* st->gc_ignored */
304 0, /* st->gc_goal_miss */
305 0, /* st->gc_dst_overflow */
306 0, /* st->in_hlist_search */
307 0 /* st->out_hlist_search */
308 );
309 return 0;
310 }
311
312 static const struct seq_operations rt_cpu_seq_ops = {
313 .start = rt_cpu_seq_start,
314 .next = rt_cpu_seq_next,
315 .stop = rt_cpu_seq_stop,
316 .show = rt_cpu_seq_show,
317 };
318
319
320 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
321 {
322 return seq_open(file, &rt_cpu_seq_ops);
323 }
324
325 static const struct file_operations rt_cpu_seq_fops = {
326 .owner = THIS_MODULE,
327 .open = rt_cpu_seq_open,
328 .read = seq_read,
329 .llseek = seq_lseek,
330 .release = seq_release,
331 };
332
333 #ifdef CONFIG_IP_ROUTE_CLASSID
334 static int rt_acct_proc_show(struct seq_file *m, void *v)
335 {
336 struct ip_rt_acct *dst, *src;
337 unsigned int i, j;
338
339 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
340 if (!dst)
341 return -ENOMEM;
342
343 for_each_possible_cpu(i) {
344 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
345 for (j = 0; j < 256; j++) {
346 dst[j].o_bytes += src[j].o_bytes;
347 dst[j].o_packets += src[j].o_packets;
348 dst[j].i_bytes += src[j].i_bytes;
349 dst[j].i_packets += src[j].i_packets;
350 }
351 }
352
353 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
354 kfree(dst);
355 return 0;
356 }
357
358 static int rt_acct_proc_open(struct inode *inode, struct file *file)
359 {
360 return single_open(file, rt_acct_proc_show, NULL);
361 }
362
363 static const struct file_operations rt_acct_proc_fops = {
364 .owner = THIS_MODULE,
365 .open = rt_acct_proc_open,
366 .read = seq_read,
367 .llseek = seq_lseek,
368 .release = single_release,
369 };
370 #endif
371
372 static int __net_init ip_rt_do_proc_init(struct net *net)
373 {
374 struct proc_dir_entry *pde;
375
376 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
377 &rt_cache_seq_fops);
378 if (!pde)
379 goto err1;
380
381 pde = proc_create("rt_cache", S_IRUGO,
382 net->proc_net_stat, &rt_cpu_seq_fops);
383 if (!pde)
384 goto err2;
385
386 #ifdef CONFIG_IP_ROUTE_CLASSID
387 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
388 if (!pde)
389 goto err3;
390 #endif
391 return 0;
392
393 #ifdef CONFIG_IP_ROUTE_CLASSID
394 err3:
395 remove_proc_entry("rt_cache", net->proc_net_stat);
396 #endif
397 err2:
398 remove_proc_entry("rt_cache", net->proc_net);
399 err1:
400 return -ENOMEM;
401 }
402
403 static void __net_exit ip_rt_do_proc_exit(struct net *net)
404 {
405 remove_proc_entry("rt_cache", net->proc_net_stat);
406 remove_proc_entry("rt_cache", net->proc_net);
407 #ifdef CONFIG_IP_ROUTE_CLASSID
408 remove_proc_entry("rt_acct", net->proc_net);
409 #endif
410 }
411
412 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
413 .init = ip_rt_do_proc_init,
414 .exit = ip_rt_do_proc_exit,
415 };
416
417 static int __init ip_rt_proc_init(void)
418 {
419 return register_pernet_subsys(&ip_rt_proc_ops);
420 }
421
422 #else
423 static inline int ip_rt_proc_init(void)
424 {
425 return 0;
426 }
427 #endif /* CONFIG_PROC_FS */
428
429 static inline bool rt_is_expired(const struct rtable *rth)
430 {
431 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
432 }
433
434 void rt_cache_flush(struct net *net)
435 {
436 rt_genid_bump_ipv4(net);
437 }
438
439 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
440 struct sk_buff *skb,
441 const void *daddr)
442 {
443 struct net_device *dev = dst->dev;
444 const __be32 *pkey = daddr;
445 const struct rtable *rt;
446 struct neighbour *n;
447
448 rt = (const struct rtable *) dst;
449 if (rt->rt_gateway)
450 pkey = (const __be32 *) &rt->rt_gateway;
451 else if (skb)
452 pkey = &ip_hdr(skb)->daddr;
453
454 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
455 if (n)
456 return n;
457 return neigh_create(&arp_tbl, pkey, dev);
458 }
459
460 #define IP_IDENTS_SZ 2048u
461 struct ip_ident_bucket {
462 atomic_t id;
463 u32 stamp32;
464 };
465
466 static struct ip_ident_bucket *ip_idents __read_mostly;
467
468 /* In order to protect privacy, we add a perturbation to identifiers
469 * if one generator is seldom used. This makes hard for an attacker
470 * to infer how many packets were sent between two points in time.
471 */
472 u32 ip_idents_reserve(u32 hash, int segs)
473 {
474 struct ip_ident_bucket *bucket = ip_idents + hash % IP_IDENTS_SZ;
475 u32 old = ACCESS_ONCE(bucket->stamp32);
476 u32 now = (u32)jiffies;
477 u32 delta = 0;
478
479 if (old != now && cmpxchg(&bucket->stamp32, old, now) == old)
480 delta = prandom_u32_max(now - old);
481
482 return atomic_add_return(segs + delta, &bucket->id) - segs;
483 }
484 EXPORT_SYMBOL(ip_idents_reserve);
485
486 void __ip_select_ident(struct iphdr *iph, int segs)
487 {
488 static u32 ip_idents_hashrnd __read_mostly;
489 u32 hash, id;
490
491 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
492
493 hash = jhash_3words((__force u32)iph->daddr,
494 (__force u32)iph->saddr,
495 iph->protocol,
496 ip_idents_hashrnd);
497 id = ip_idents_reserve(hash, segs);
498 iph->id = htons(id);
499 }
500 EXPORT_SYMBOL(__ip_select_ident);
501
502 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
503 const struct iphdr *iph,
504 int oif, u8 tos,
505 u8 prot, u32 mark, int flow_flags)
506 {
507 if (sk) {
508 const struct inet_sock *inet = inet_sk(sk);
509
510 oif = sk->sk_bound_dev_if;
511 mark = sk->sk_mark;
512 tos = RT_CONN_FLAGS(sk);
513 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
514 }
515 flowi4_init_output(fl4, oif, mark, tos,
516 RT_SCOPE_UNIVERSE, prot,
517 flow_flags,
518 iph->daddr, iph->saddr, 0, 0);
519 }
520
521 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
522 const struct sock *sk)
523 {
524 const struct iphdr *iph = ip_hdr(skb);
525 int oif = skb->dev->ifindex;
526 u8 tos = RT_TOS(iph->tos);
527 u8 prot = iph->protocol;
528 u32 mark = skb->mark;
529
530 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
531 }
532
533 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
534 {
535 const struct inet_sock *inet = inet_sk(sk);
536 const struct ip_options_rcu *inet_opt;
537 __be32 daddr = inet->inet_daddr;
538
539 rcu_read_lock();
540 inet_opt = rcu_dereference(inet->inet_opt);
541 if (inet_opt && inet_opt->opt.srr)
542 daddr = inet_opt->opt.faddr;
543 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
544 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
545 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
546 inet_sk_flowi_flags(sk),
547 daddr, inet->inet_saddr, 0, 0);
548 rcu_read_unlock();
549 }
550
551 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
552 const struct sk_buff *skb)
553 {
554 if (skb)
555 build_skb_flow_key(fl4, skb, sk);
556 else
557 build_sk_flow_key(fl4, sk);
558 }
559
560 static inline void rt_free(struct rtable *rt)
561 {
562 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
563 }
564
565 static DEFINE_SPINLOCK(fnhe_lock);
566
567 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
568 {
569 struct rtable *rt;
570
571 rt = rcu_dereference(fnhe->fnhe_rth_input);
572 if (rt) {
573 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
574 rt_free(rt);
575 }
576 rt = rcu_dereference(fnhe->fnhe_rth_output);
577 if (rt) {
578 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
579 rt_free(rt);
580 }
581 }
582
583 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
584 {
585 struct fib_nh_exception *fnhe, *oldest;
586
587 oldest = rcu_dereference(hash->chain);
588 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
589 fnhe = rcu_dereference(fnhe->fnhe_next)) {
590 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
591 oldest = fnhe;
592 }
593 fnhe_flush_routes(oldest);
594 return oldest;
595 }
596
597 static inline u32 fnhe_hashfun(__be32 daddr)
598 {
599 static u32 fnhe_hashrnd __read_mostly;
600 u32 hval;
601
602 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
603 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
604 return hash_32(hval, FNHE_HASH_SHIFT);
605 }
606
607 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
608 {
609 rt->rt_pmtu = fnhe->fnhe_pmtu;
610 rt->dst.expires = fnhe->fnhe_expires;
611
612 if (fnhe->fnhe_gw) {
613 rt->rt_flags |= RTCF_REDIRECTED;
614 rt->rt_gateway = fnhe->fnhe_gw;
615 rt->rt_uses_gateway = 1;
616 }
617 }
618
619 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
620 u32 pmtu, unsigned long expires)
621 {
622 struct fnhe_hash_bucket *hash;
623 struct fib_nh_exception *fnhe;
624 struct rtable *rt;
625 unsigned int i;
626 int depth;
627 u32 hval = fnhe_hashfun(daddr);
628
629 spin_lock_bh(&fnhe_lock);
630
631 hash = rcu_dereference(nh->nh_exceptions);
632 if (!hash) {
633 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
634 if (!hash)
635 goto out_unlock;
636 rcu_assign_pointer(nh->nh_exceptions, hash);
637 }
638
639 hash += hval;
640
641 depth = 0;
642 for (fnhe = rcu_dereference(hash->chain); fnhe;
643 fnhe = rcu_dereference(fnhe->fnhe_next)) {
644 if (fnhe->fnhe_daddr == daddr)
645 break;
646 depth++;
647 }
648
649 if (fnhe) {
650 if (gw)
651 fnhe->fnhe_gw = gw;
652 if (pmtu) {
653 fnhe->fnhe_pmtu = pmtu;
654 fnhe->fnhe_expires = max(1UL, expires);
655 }
656 /* Update all cached dsts too */
657 rt = rcu_dereference(fnhe->fnhe_rth_input);
658 if (rt)
659 fill_route_from_fnhe(rt, fnhe);
660 rt = rcu_dereference(fnhe->fnhe_rth_output);
661 if (rt)
662 fill_route_from_fnhe(rt, fnhe);
663 } else {
664 if (depth > FNHE_RECLAIM_DEPTH)
665 fnhe = fnhe_oldest(hash);
666 else {
667 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
668 if (!fnhe)
669 goto out_unlock;
670
671 fnhe->fnhe_next = hash->chain;
672 rcu_assign_pointer(hash->chain, fnhe);
673 }
674 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
675 fnhe->fnhe_daddr = daddr;
676 fnhe->fnhe_gw = gw;
677 fnhe->fnhe_pmtu = pmtu;
678 fnhe->fnhe_expires = expires;
679
680 /* Exception created; mark the cached routes for the nexthop
681 * stale, so anyone caching it rechecks if this exception
682 * applies to them.
683 */
684 rt = rcu_dereference(nh->nh_rth_input);
685 if (rt)
686 rt->dst.obsolete = DST_OBSOLETE_KILL;
687
688 for_each_possible_cpu(i) {
689 struct rtable __rcu **prt;
690 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
691 rt = rcu_dereference(*prt);
692 if (rt)
693 rt->dst.obsolete = DST_OBSOLETE_KILL;
694 }
695 }
696
697 fnhe->fnhe_stamp = jiffies;
698
699 out_unlock:
700 spin_unlock_bh(&fnhe_lock);
701 }
702
703 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
704 bool kill_route)
705 {
706 __be32 new_gw = icmp_hdr(skb)->un.gateway;
707 __be32 old_gw = ip_hdr(skb)->saddr;
708 struct net_device *dev = skb->dev;
709 struct in_device *in_dev;
710 struct fib_result res;
711 struct neighbour *n;
712 struct net *net;
713
714 switch (icmp_hdr(skb)->code & 7) {
715 case ICMP_REDIR_NET:
716 case ICMP_REDIR_NETTOS:
717 case ICMP_REDIR_HOST:
718 case ICMP_REDIR_HOSTTOS:
719 break;
720
721 default:
722 return;
723 }
724
725 if (rt->rt_gateway != old_gw)
726 return;
727
728 in_dev = __in_dev_get_rcu(dev);
729 if (!in_dev)
730 return;
731
732 net = dev_net(dev);
733 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
734 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
735 ipv4_is_zeronet(new_gw))
736 goto reject_redirect;
737
738 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
739 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
740 goto reject_redirect;
741 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
742 goto reject_redirect;
743 } else {
744 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
745 goto reject_redirect;
746 }
747
748 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
749 if (!IS_ERR(n)) {
750 if (!(n->nud_state & NUD_VALID)) {
751 neigh_event_send(n, NULL);
752 } else {
753 if (fib_lookup(net, fl4, &res) == 0) {
754 struct fib_nh *nh = &FIB_RES_NH(res);
755
756 update_or_create_fnhe(nh, fl4->daddr, new_gw,
757 0, 0);
758 }
759 if (kill_route)
760 rt->dst.obsolete = DST_OBSOLETE_KILL;
761 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
762 }
763 neigh_release(n);
764 }
765 return;
766
767 reject_redirect:
768 #ifdef CONFIG_IP_ROUTE_VERBOSE
769 if (IN_DEV_LOG_MARTIANS(in_dev)) {
770 const struct iphdr *iph = (const struct iphdr *) skb->data;
771 __be32 daddr = iph->daddr;
772 __be32 saddr = iph->saddr;
773
774 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
775 " Advised path = %pI4 -> %pI4\n",
776 &old_gw, dev->name, &new_gw,
777 &saddr, &daddr);
778 }
779 #endif
780 ;
781 }
782
783 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
784 {
785 struct rtable *rt;
786 struct flowi4 fl4;
787 const struct iphdr *iph = (const struct iphdr *) skb->data;
788 int oif = skb->dev->ifindex;
789 u8 tos = RT_TOS(iph->tos);
790 u8 prot = iph->protocol;
791 u32 mark = skb->mark;
792
793 rt = (struct rtable *) dst;
794
795 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
796 __ip_do_redirect(rt, skb, &fl4, true);
797 }
798
799 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
800 {
801 struct rtable *rt = (struct rtable *)dst;
802 struct dst_entry *ret = dst;
803
804 if (rt) {
805 if (dst->obsolete > 0) {
806 ip_rt_put(rt);
807 ret = NULL;
808 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
809 rt->dst.expires) {
810 ip_rt_put(rt);
811 ret = NULL;
812 }
813 }
814 return ret;
815 }
816
817 /*
818 * Algorithm:
819 * 1. The first ip_rt_redirect_number redirects are sent
820 * with exponential backoff, then we stop sending them at all,
821 * assuming that the host ignores our redirects.
822 * 2. If we did not see packets requiring redirects
823 * during ip_rt_redirect_silence, we assume that the host
824 * forgot redirected route and start to send redirects again.
825 *
826 * This algorithm is much cheaper and more intelligent than dumb load limiting
827 * in icmp.c.
828 *
829 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
830 * and "frag. need" (breaks PMTU discovery) in icmp.c.
831 */
832
833 void ip_rt_send_redirect(struct sk_buff *skb)
834 {
835 struct rtable *rt = skb_rtable(skb);
836 struct in_device *in_dev;
837 struct inet_peer *peer;
838 struct net *net;
839 int log_martians;
840
841 rcu_read_lock();
842 in_dev = __in_dev_get_rcu(rt->dst.dev);
843 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
844 rcu_read_unlock();
845 return;
846 }
847 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
848 rcu_read_unlock();
849
850 net = dev_net(rt->dst.dev);
851 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
852 if (!peer) {
853 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
854 rt_nexthop(rt, ip_hdr(skb)->daddr));
855 return;
856 }
857
858 /* No redirected packets during ip_rt_redirect_silence;
859 * reset the algorithm.
860 */
861 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
862 peer->rate_tokens = 0;
863
864 /* Too many ignored redirects; do not send anything
865 * set dst.rate_last to the last seen redirected packet.
866 */
867 if (peer->rate_tokens >= ip_rt_redirect_number) {
868 peer->rate_last = jiffies;
869 goto out_put_peer;
870 }
871
872 /* Check for load limit; set rate_last to the latest sent
873 * redirect.
874 */
875 if (peer->rate_tokens == 0 ||
876 time_after(jiffies,
877 (peer->rate_last +
878 (ip_rt_redirect_load << peer->rate_tokens)))) {
879 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
880
881 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
882 peer->rate_last = jiffies;
883 ++peer->rate_tokens;
884 #ifdef CONFIG_IP_ROUTE_VERBOSE
885 if (log_martians &&
886 peer->rate_tokens == ip_rt_redirect_number)
887 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
888 &ip_hdr(skb)->saddr, inet_iif(skb),
889 &ip_hdr(skb)->daddr, &gw);
890 #endif
891 }
892 out_put_peer:
893 inet_putpeer(peer);
894 }
895
896 static int ip_error(struct sk_buff *skb)
897 {
898 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
899 struct rtable *rt = skb_rtable(skb);
900 struct inet_peer *peer;
901 unsigned long now;
902 struct net *net;
903 bool send;
904 int code;
905
906 net = dev_net(rt->dst.dev);
907 if (!IN_DEV_FORWARD(in_dev)) {
908 switch (rt->dst.error) {
909 case EHOSTUNREACH:
910 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
911 break;
912
913 case ENETUNREACH:
914 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
915 break;
916 }
917 goto out;
918 }
919
920 switch (rt->dst.error) {
921 case EINVAL:
922 default:
923 goto out;
924 case EHOSTUNREACH:
925 code = ICMP_HOST_UNREACH;
926 break;
927 case ENETUNREACH:
928 code = ICMP_NET_UNREACH;
929 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
930 break;
931 case EACCES:
932 code = ICMP_PKT_FILTERED;
933 break;
934 }
935
936 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
937
938 send = true;
939 if (peer) {
940 now = jiffies;
941 peer->rate_tokens += now - peer->rate_last;
942 if (peer->rate_tokens > ip_rt_error_burst)
943 peer->rate_tokens = ip_rt_error_burst;
944 peer->rate_last = now;
945 if (peer->rate_tokens >= ip_rt_error_cost)
946 peer->rate_tokens -= ip_rt_error_cost;
947 else
948 send = false;
949 inet_putpeer(peer);
950 }
951 if (send)
952 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
953
954 out: kfree_skb(skb);
955 return 0;
956 }
957
958 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
959 {
960 struct dst_entry *dst = &rt->dst;
961 struct fib_result res;
962
963 if (dst_metric_locked(dst, RTAX_MTU))
964 return;
965
966 if (dst->dev->mtu < mtu)
967 return;
968
969 if (mtu < ip_rt_min_pmtu)
970 mtu = ip_rt_min_pmtu;
971
972 if (rt->rt_pmtu == mtu &&
973 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
974 return;
975
976 rcu_read_lock();
977 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
978 struct fib_nh *nh = &FIB_RES_NH(res);
979
980 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
981 jiffies + ip_rt_mtu_expires);
982 }
983 rcu_read_unlock();
984 }
985
986 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
987 struct sk_buff *skb, u32 mtu)
988 {
989 struct rtable *rt = (struct rtable *) dst;
990 struct flowi4 fl4;
991
992 ip_rt_build_flow_key(&fl4, sk, skb);
993 __ip_rt_update_pmtu(rt, &fl4, mtu);
994 }
995
996 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
997 int oif, u32 mark, u8 protocol, int flow_flags)
998 {
999 const struct iphdr *iph = (const struct iphdr *) skb->data;
1000 struct flowi4 fl4;
1001 struct rtable *rt;
1002
1003 if (!mark)
1004 mark = IP4_REPLY_MARK(net, skb->mark);
1005
1006 __build_flow_key(&fl4, NULL, iph, oif,
1007 RT_TOS(iph->tos), protocol, mark, flow_flags);
1008 rt = __ip_route_output_key(net, &fl4);
1009 if (!IS_ERR(rt)) {
1010 __ip_rt_update_pmtu(rt, &fl4, mtu);
1011 ip_rt_put(rt);
1012 }
1013 }
1014 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1015
1016 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1017 {
1018 const struct iphdr *iph = (const struct iphdr *) skb->data;
1019 struct flowi4 fl4;
1020 struct rtable *rt;
1021
1022 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1023
1024 if (!fl4.flowi4_mark)
1025 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1026
1027 rt = __ip_route_output_key(sock_net(sk), &fl4);
1028 if (!IS_ERR(rt)) {
1029 __ip_rt_update_pmtu(rt, &fl4, mtu);
1030 ip_rt_put(rt);
1031 }
1032 }
1033
1034 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1035 {
1036 const struct iphdr *iph = (const struct iphdr *) skb->data;
1037 struct flowi4 fl4;
1038 struct rtable *rt;
1039 struct dst_entry *odst = NULL;
1040 bool new = false;
1041
1042 bh_lock_sock(sk);
1043
1044 if (!ip_sk_accept_pmtu(sk))
1045 goto out;
1046
1047 odst = sk_dst_get(sk);
1048
1049 if (sock_owned_by_user(sk) || !odst) {
1050 __ipv4_sk_update_pmtu(skb, sk, mtu);
1051 goto out;
1052 }
1053
1054 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1055
1056 rt = (struct rtable *)odst;
1057 if (odst->obsolete && odst->ops->check(odst, 0) == NULL) {
1058 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1059 if (IS_ERR(rt))
1060 goto out;
1061
1062 new = true;
1063 }
1064
1065 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1066
1067 if (!dst_check(&rt->dst, 0)) {
1068 if (new)
1069 dst_release(&rt->dst);
1070
1071 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1072 if (IS_ERR(rt))
1073 goto out;
1074
1075 new = true;
1076 }
1077
1078 if (new)
1079 sk_dst_set(sk, &rt->dst);
1080
1081 out:
1082 bh_unlock_sock(sk);
1083 dst_release(odst);
1084 }
1085 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1086
1087 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1088 int oif, u32 mark, u8 protocol, int flow_flags)
1089 {
1090 const struct iphdr *iph = (const struct iphdr *) skb->data;
1091 struct flowi4 fl4;
1092 struct rtable *rt;
1093
1094 __build_flow_key(&fl4, NULL, iph, oif,
1095 RT_TOS(iph->tos), protocol, mark, flow_flags);
1096 rt = __ip_route_output_key(net, &fl4);
1097 if (!IS_ERR(rt)) {
1098 __ip_do_redirect(rt, skb, &fl4, false);
1099 ip_rt_put(rt);
1100 }
1101 }
1102 EXPORT_SYMBOL_GPL(ipv4_redirect);
1103
1104 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1105 {
1106 const struct iphdr *iph = (const struct iphdr *) skb->data;
1107 struct flowi4 fl4;
1108 struct rtable *rt;
1109
1110 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1111 rt = __ip_route_output_key(sock_net(sk), &fl4);
1112 if (!IS_ERR(rt)) {
1113 __ip_do_redirect(rt, skb, &fl4, false);
1114 ip_rt_put(rt);
1115 }
1116 }
1117 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1118
1119 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1120 {
1121 struct rtable *rt = (struct rtable *) dst;
1122
1123 /* All IPV4 dsts are created with ->obsolete set to the value
1124 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1125 * into this function always.
1126 *
1127 * When a PMTU/redirect information update invalidates a route,
1128 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1129 * DST_OBSOLETE_DEAD by dst_free().
1130 */
1131 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1132 return NULL;
1133 return dst;
1134 }
1135
1136 static void ipv4_link_failure(struct sk_buff *skb)
1137 {
1138 struct rtable *rt;
1139
1140 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1141
1142 rt = skb_rtable(skb);
1143 if (rt)
1144 dst_set_expires(&rt->dst, 0);
1145 }
1146
1147 static int ip_rt_bug(struct sock *sk, struct sk_buff *skb)
1148 {
1149 pr_debug("%s: %pI4 -> %pI4, %s\n",
1150 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1151 skb->dev ? skb->dev->name : "?");
1152 kfree_skb(skb);
1153 WARN_ON(1);
1154 return 0;
1155 }
1156
1157 /*
1158 We do not cache source address of outgoing interface,
1159 because it is used only by IP RR, TS and SRR options,
1160 so that it out of fast path.
1161
1162 BTW remember: "addr" is allowed to be not aligned
1163 in IP options!
1164 */
1165
1166 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1167 {
1168 __be32 src;
1169
1170 if (rt_is_output_route(rt))
1171 src = ip_hdr(skb)->saddr;
1172 else {
1173 struct fib_result res;
1174 struct flowi4 fl4;
1175 struct iphdr *iph;
1176
1177 iph = ip_hdr(skb);
1178
1179 memset(&fl4, 0, sizeof(fl4));
1180 fl4.daddr = iph->daddr;
1181 fl4.saddr = iph->saddr;
1182 fl4.flowi4_tos = RT_TOS(iph->tos);
1183 fl4.flowi4_oif = rt->dst.dev->ifindex;
1184 fl4.flowi4_iif = skb->dev->ifindex;
1185 fl4.flowi4_mark = skb->mark;
1186
1187 rcu_read_lock();
1188 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1189 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1190 else
1191 src = inet_select_addr(rt->dst.dev,
1192 rt_nexthop(rt, iph->daddr),
1193 RT_SCOPE_UNIVERSE);
1194 rcu_read_unlock();
1195 }
1196 memcpy(addr, &src, 4);
1197 }
1198
1199 #ifdef CONFIG_IP_ROUTE_CLASSID
1200 static void set_class_tag(struct rtable *rt, u32 tag)
1201 {
1202 if (!(rt->dst.tclassid & 0xFFFF))
1203 rt->dst.tclassid |= tag & 0xFFFF;
1204 if (!(rt->dst.tclassid & 0xFFFF0000))
1205 rt->dst.tclassid |= tag & 0xFFFF0000;
1206 }
1207 #endif
1208
1209 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1210 {
1211 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1212
1213 if (advmss == 0) {
1214 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1215 ip_rt_min_advmss);
1216 if (advmss > 65535 - 40)
1217 advmss = 65535 - 40;
1218 }
1219 return advmss;
1220 }
1221
1222 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1223 {
1224 const struct rtable *rt = (const struct rtable *) dst;
1225 unsigned int mtu = rt->rt_pmtu;
1226
1227 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1228 mtu = dst_metric_raw(dst, RTAX_MTU);
1229
1230 if (mtu)
1231 return mtu;
1232
1233 mtu = dst->dev->mtu;
1234
1235 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1236 if (rt->rt_uses_gateway && mtu > 576)
1237 mtu = 576;
1238 }
1239
1240 return min_t(unsigned int, mtu, IP_MAX_MTU);
1241 }
1242
1243 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1244 {
1245 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1246 struct fib_nh_exception *fnhe;
1247 u32 hval;
1248
1249 if (!hash)
1250 return NULL;
1251
1252 hval = fnhe_hashfun(daddr);
1253
1254 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1255 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1256 if (fnhe->fnhe_daddr == daddr)
1257 return fnhe;
1258 }
1259 return NULL;
1260 }
1261
1262 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1263 __be32 daddr)
1264 {
1265 bool ret = false;
1266
1267 spin_lock_bh(&fnhe_lock);
1268
1269 if (daddr == fnhe->fnhe_daddr) {
1270 struct rtable __rcu **porig;
1271 struct rtable *orig;
1272 int genid = fnhe_genid(dev_net(rt->dst.dev));
1273
1274 if (rt_is_input_route(rt))
1275 porig = &fnhe->fnhe_rth_input;
1276 else
1277 porig = &fnhe->fnhe_rth_output;
1278 orig = rcu_dereference(*porig);
1279
1280 if (fnhe->fnhe_genid != genid) {
1281 fnhe->fnhe_genid = genid;
1282 fnhe->fnhe_gw = 0;
1283 fnhe->fnhe_pmtu = 0;
1284 fnhe->fnhe_expires = 0;
1285 fnhe_flush_routes(fnhe);
1286 orig = NULL;
1287 }
1288 fill_route_from_fnhe(rt, fnhe);
1289 if (!rt->rt_gateway)
1290 rt->rt_gateway = daddr;
1291
1292 if (!(rt->dst.flags & DST_NOCACHE)) {
1293 rcu_assign_pointer(*porig, rt);
1294 if (orig)
1295 rt_free(orig);
1296 ret = true;
1297 }
1298
1299 fnhe->fnhe_stamp = jiffies;
1300 }
1301 spin_unlock_bh(&fnhe_lock);
1302
1303 return ret;
1304 }
1305
1306 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1307 {
1308 struct rtable *orig, *prev, **p;
1309 bool ret = true;
1310
1311 if (rt_is_input_route(rt)) {
1312 p = (struct rtable **)&nh->nh_rth_input;
1313 } else {
1314 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1315 }
1316 orig = *p;
1317
1318 prev = cmpxchg(p, orig, rt);
1319 if (prev == orig) {
1320 if (orig)
1321 rt_free(orig);
1322 } else
1323 ret = false;
1324
1325 return ret;
1326 }
1327
1328 struct uncached_list {
1329 spinlock_t lock;
1330 struct list_head head;
1331 };
1332
1333 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1334
1335 static void rt_add_uncached_list(struct rtable *rt)
1336 {
1337 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1338
1339 rt->rt_uncached_list = ul;
1340
1341 spin_lock_bh(&ul->lock);
1342 list_add_tail(&rt->rt_uncached, &ul->head);
1343 spin_unlock_bh(&ul->lock);
1344 }
1345
1346 static void ipv4_dst_destroy(struct dst_entry *dst)
1347 {
1348 struct rtable *rt = (struct rtable *) dst;
1349
1350 if (!list_empty(&rt->rt_uncached)) {
1351 struct uncached_list *ul = rt->rt_uncached_list;
1352
1353 spin_lock_bh(&ul->lock);
1354 list_del(&rt->rt_uncached);
1355 spin_unlock_bh(&ul->lock);
1356 }
1357 }
1358
1359 void rt_flush_dev(struct net_device *dev)
1360 {
1361 struct net *net = dev_net(dev);
1362 struct rtable *rt;
1363 int cpu;
1364
1365 for_each_possible_cpu(cpu) {
1366 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1367
1368 spin_lock_bh(&ul->lock);
1369 list_for_each_entry(rt, &ul->head, rt_uncached) {
1370 if (rt->dst.dev != dev)
1371 continue;
1372 rt->dst.dev = net->loopback_dev;
1373 dev_hold(rt->dst.dev);
1374 dev_put(dev);
1375 }
1376 spin_unlock_bh(&ul->lock);
1377 }
1378 }
1379
1380 static bool rt_cache_valid(const struct rtable *rt)
1381 {
1382 return rt &&
1383 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1384 !rt_is_expired(rt);
1385 }
1386
1387 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1388 const struct fib_result *res,
1389 struct fib_nh_exception *fnhe,
1390 struct fib_info *fi, u16 type, u32 itag)
1391 {
1392 bool cached = false;
1393
1394 if (fi) {
1395 struct fib_nh *nh = &FIB_RES_NH(*res);
1396
1397 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1398 rt->rt_gateway = nh->nh_gw;
1399 rt->rt_uses_gateway = 1;
1400 }
1401 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1402 #ifdef CONFIG_IP_ROUTE_CLASSID
1403 rt->dst.tclassid = nh->nh_tclassid;
1404 #endif
1405 if (unlikely(fnhe))
1406 cached = rt_bind_exception(rt, fnhe, daddr);
1407 else if (!(rt->dst.flags & DST_NOCACHE))
1408 cached = rt_cache_route(nh, rt);
1409 if (unlikely(!cached)) {
1410 /* Routes we intend to cache in nexthop exception or
1411 * FIB nexthop have the DST_NOCACHE bit clear.
1412 * However, if we are unsuccessful at storing this
1413 * route into the cache we really need to set it.
1414 */
1415 rt->dst.flags |= DST_NOCACHE;
1416 if (!rt->rt_gateway)
1417 rt->rt_gateway = daddr;
1418 rt_add_uncached_list(rt);
1419 }
1420 } else
1421 rt_add_uncached_list(rt);
1422
1423 #ifdef CONFIG_IP_ROUTE_CLASSID
1424 #ifdef CONFIG_IP_MULTIPLE_TABLES
1425 set_class_tag(rt, res->tclassid);
1426 #endif
1427 set_class_tag(rt, itag);
1428 #endif
1429 }
1430
1431 static struct rtable *rt_dst_alloc(struct net_device *dev,
1432 bool nopolicy, bool noxfrm, bool will_cache)
1433 {
1434 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1435 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1436 (nopolicy ? DST_NOPOLICY : 0) |
1437 (noxfrm ? DST_NOXFRM : 0));
1438 }
1439
1440 /* called in rcu_read_lock() section */
1441 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1442 u8 tos, struct net_device *dev, int our)
1443 {
1444 struct rtable *rth;
1445 struct in_device *in_dev = __in_dev_get_rcu(dev);
1446 u32 itag = 0;
1447 int err;
1448
1449 /* Primary sanity checks. */
1450
1451 if (in_dev == NULL)
1452 return -EINVAL;
1453
1454 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1455 skb->protocol != htons(ETH_P_IP))
1456 goto e_inval;
1457
1458 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1459 if (ipv4_is_loopback(saddr))
1460 goto e_inval;
1461
1462 if (ipv4_is_zeronet(saddr)) {
1463 if (!ipv4_is_local_multicast(daddr))
1464 goto e_inval;
1465 } else {
1466 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1467 in_dev, &itag);
1468 if (err < 0)
1469 goto e_err;
1470 }
1471 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1472 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1473 if (!rth)
1474 goto e_nobufs;
1475
1476 #ifdef CONFIG_IP_ROUTE_CLASSID
1477 rth->dst.tclassid = itag;
1478 #endif
1479 rth->dst.output = ip_rt_bug;
1480
1481 rth->rt_genid = rt_genid_ipv4(dev_net(dev));
1482 rth->rt_flags = RTCF_MULTICAST;
1483 rth->rt_type = RTN_MULTICAST;
1484 rth->rt_is_input= 1;
1485 rth->rt_iif = 0;
1486 rth->rt_pmtu = 0;
1487 rth->rt_gateway = 0;
1488 rth->rt_uses_gateway = 0;
1489 INIT_LIST_HEAD(&rth->rt_uncached);
1490 if (our) {
1491 rth->dst.input= ip_local_deliver;
1492 rth->rt_flags |= RTCF_LOCAL;
1493 }
1494
1495 #ifdef CONFIG_IP_MROUTE
1496 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1497 rth->dst.input = ip_mr_input;
1498 #endif
1499 RT_CACHE_STAT_INC(in_slow_mc);
1500
1501 skb_dst_set(skb, &rth->dst);
1502 return 0;
1503
1504 e_nobufs:
1505 return -ENOBUFS;
1506 e_inval:
1507 return -EINVAL;
1508 e_err:
1509 return err;
1510 }
1511
1512
1513 static void ip_handle_martian_source(struct net_device *dev,
1514 struct in_device *in_dev,
1515 struct sk_buff *skb,
1516 __be32 daddr,
1517 __be32 saddr)
1518 {
1519 RT_CACHE_STAT_INC(in_martian_src);
1520 #ifdef CONFIG_IP_ROUTE_VERBOSE
1521 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1522 /*
1523 * RFC1812 recommendation, if source is martian,
1524 * the only hint is MAC header.
1525 */
1526 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1527 &daddr, &saddr, dev->name);
1528 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1529 print_hex_dump(KERN_WARNING, "ll header: ",
1530 DUMP_PREFIX_OFFSET, 16, 1,
1531 skb_mac_header(skb),
1532 dev->hard_header_len, true);
1533 }
1534 }
1535 #endif
1536 }
1537
1538 /* called in rcu_read_lock() section */
1539 static int __mkroute_input(struct sk_buff *skb,
1540 const struct fib_result *res,
1541 struct in_device *in_dev,
1542 __be32 daddr, __be32 saddr, u32 tos)
1543 {
1544 struct fib_nh_exception *fnhe;
1545 struct rtable *rth;
1546 int err;
1547 struct in_device *out_dev;
1548 unsigned int flags = 0;
1549 bool do_cache;
1550 u32 itag = 0;
1551
1552 /* get a working reference to the output device */
1553 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1554 if (out_dev == NULL) {
1555 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1556 return -EINVAL;
1557 }
1558
1559 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1560 in_dev->dev, in_dev, &itag);
1561 if (err < 0) {
1562 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1563 saddr);
1564
1565 goto cleanup;
1566 }
1567
1568 do_cache = res->fi && !itag;
1569 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1570 (IN_DEV_SHARED_MEDIA(out_dev) ||
1571 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) {
1572 flags |= RTCF_DOREDIRECT;
1573 do_cache = false;
1574 }
1575
1576 if (skb->protocol != htons(ETH_P_IP)) {
1577 /* Not IP (i.e. ARP). Do not create route, if it is
1578 * invalid for proxy arp. DNAT routes are always valid.
1579 *
1580 * Proxy arp feature have been extended to allow, ARP
1581 * replies back to the same interface, to support
1582 * Private VLAN switch technologies. See arp.c.
1583 */
1584 if (out_dev == in_dev &&
1585 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1586 err = -EINVAL;
1587 goto cleanup;
1588 }
1589 }
1590
1591 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1592 if (do_cache) {
1593 if (fnhe != NULL)
1594 rth = rcu_dereference(fnhe->fnhe_rth_input);
1595 else
1596 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1597
1598 if (rt_cache_valid(rth)) {
1599 skb_dst_set_noref(skb, &rth->dst);
1600 goto out;
1601 }
1602 }
1603
1604 rth = rt_dst_alloc(out_dev->dev,
1605 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1606 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1607 if (!rth) {
1608 err = -ENOBUFS;
1609 goto cleanup;
1610 }
1611
1612 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev));
1613 rth->rt_flags = flags;
1614 rth->rt_type = res->type;
1615 rth->rt_is_input = 1;
1616 rth->rt_iif = 0;
1617 rth->rt_pmtu = 0;
1618 rth->rt_gateway = 0;
1619 rth->rt_uses_gateway = 0;
1620 INIT_LIST_HEAD(&rth->rt_uncached);
1621 RT_CACHE_STAT_INC(in_slow_tot);
1622
1623 rth->dst.input = ip_forward;
1624 rth->dst.output = ip_output;
1625
1626 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1627 skb_dst_set(skb, &rth->dst);
1628 out:
1629 err = 0;
1630 cleanup:
1631 return err;
1632 }
1633
1634 static int ip_mkroute_input(struct sk_buff *skb,
1635 struct fib_result *res,
1636 const struct flowi4 *fl4,
1637 struct in_device *in_dev,
1638 __be32 daddr, __be32 saddr, u32 tos)
1639 {
1640 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1641 if (res->fi && res->fi->fib_nhs > 1)
1642 fib_select_multipath(res);
1643 #endif
1644
1645 /* create a routing cache entry */
1646 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1647 }
1648
1649 /*
1650 * NOTE. We drop all the packets that has local source
1651 * addresses, because every properly looped back packet
1652 * must have correct destination already attached by output routine.
1653 *
1654 * Such approach solves two big problems:
1655 * 1. Not simplex devices are handled properly.
1656 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1657 * called with rcu_read_lock()
1658 */
1659
1660 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1661 u8 tos, struct net_device *dev)
1662 {
1663 struct fib_result res;
1664 struct in_device *in_dev = __in_dev_get_rcu(dev);
1665 struct flowi4 fl4;
1666 unsigned int flags = 0;
1667 u32 itag = 0;
1668 struct rtable *rth;
1669 int err = -EINVAL;
1670 struct net *net = dev_net(dev);
1671 bool do_cache;
1672
1673 /* IP on this device is disabled. */
1674
1675 if (!in_dev)
1676 goto out;
1677
1678 /* Check for the most weird martians, which can be not detected
1679 by fib_lookup.
1680 */
1681
1682 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1683 goto martian_source;
1684
1685 res.fi = NULL;
1686 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1687 goto brd_input;
1688
1689 /* Accept zero addresses only to limited broadcast;
1690 * I even do not know to fix it or not. Waiting for complains :-)
1691 */
1692 if (ipv4_is_zeronet(saddr))
1693 goto martian_source;
1694
1695 if (ipv4_is_zeronet(daddr))
1696 goto martian_destination;
1697
1698 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1699 * and call it once if daddr or/and saddr are loopback addresses
1700 */
1701 if (ipv4_is_loopback(daddr)) {
1702 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1703 goto martian_destination;
1704 } else if (ipv4_is_loopback(saddr)) {
1705 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1706 goto martian_source;
1707 }
1708
1709 /*
1710 * Now we are ready to route packet.
1711 */
1712 fl4.flowi4_oif = 0;
1713 fl4.flowi4_iif = dev->ifindex;
1714 fl4.flowi4_mark = skb->mark;
1715 fl4.flowi4_tos = tos;
1716 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1717 fl4.daddr = daddr;
1718 fl4.saddr = saddr;
1719 err = fib_lookup(net, &fl4, &res);
1720 if (err != 0) {
1721 if (!IN_DEV_FORWARD(in_dev))
1722 err = -EHOSTUNREACH;
1723 goto no_route;
1724 }
1725
1726 if (res.type == RTN_BROADCAST)
1727 goto brd_input;
1728
1729 if (res.type == RTN_LOCAL) {
1730 err = fib_validate_source(skb, saddr, daddr, tos,
1731 0, dev, in_dev, &itag);
1732 if (err < 0)
1733 goto martian_source_keep_err;
1734 goto local_input;
1735 }
1736
1737 if (!IN_DEV_FORWARD(in_dev)) {
1738 err = -EHOSTUNREACH;
1739 goto no_route;
1740 }
1741 if (res.type != RTN_UNICAST)
1742 goto martian_destination;
1743
1744 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1745 out: return err;
1746
1747 brd_input:
1748 if (skb->protocol != htons(ETH_P_IP))
1749 goto e_inval;
1750
1751 if (!ipv4_is_zeronet(saddr)) {
1752 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1753 in_dev, &itag);
1754 if (err < 0)
1755 goto martian_source_keep_err;
1756 }
1757 flags |= RTCF_BROADCAST;
1758 res.type = RTN_BROADCAST;
1759 RT_CACHE_STAT_INC(in_brd);
1760
1761 local_input:
1762 do_cache = false;
1763 if (res.fi) {
1764 if (!itag) {
1765 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1766 if (rt_cache_valid(rth)) {
1767 skb_dst_set_noref(skb, &rth->dst);
1768 err = 0;
1769 goto out;
1770 }
1771 do_cache = true;
1772 }
1773 }
1774
1775 rth = rt_dst_alloc(net->loopback_dev,
1776 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1777 if (!rth)
1778 goto e_nobufs;
1779
1780 rth->dst.input= ip_local_deliver;
1781 rth->dst.output= ip_rt_bug;
1782 #ifdef CONFIG_IP_ROUTE_CLASSID
1783 rth->dst.tclassid = itag;
1784 #endif
1785
1786 rth->rt_genid = rt_genid_ipv4(net);
1787 rth->rt_flags = flags|RTCF_LOCAL;
1788 rth->rt_type = res.type;
1789 rth->rt_is_input = 1;
1790 rth->rt_iif = 0;
1791 rth->rt_pmtu = 0;
1792 rth->rt_gateway = 0;
1793 rth->rt_uses_gateway = 0;
1794 INIT_LIST_HEAD(&rth->rt_uncached);
1795 RT_CACHE_STAT_INC(in_slow_tot);
1796 if (res.type == RTN_UNREACHABLE) {
1797 rth->dst.input= ip_error;
1798 rth->dst.error= -err;
1799 rth->rt_flags &= ~RTCF_LOCAL;
1800 }
1801 if (do_cache) {
1802 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1803 rth->dst.flags |= DST_NOCACHE;
1804 rt_add_uncached_list(rth);
1805 }
1806 }
1807 skb_dst_set(skb, &rth->dst);
1808 err = 0;
1809 goto out;
1810
1811 no_route:
1812 RT_CACHE_STAT_INC(in_no_route);
1813 res.type = RTN_UNREACHABLE;
1814 res.fi = NULL;
1815 goto local_input;
1816
1817 /*
1818 * Do not cache martian addresses: they should be logged (RFC1812)
1819 */
1820 martian_destination:
1821 RT_CACHE_STAT_INC(in_martian_dst);
1822 #ifdef CONFIG_IP_ROUTE_VERBOSE
1823 if (IN_DEV_LOG_MARTIANS(in_dev))
1824 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1825 &daddr, &saddr, dev->name);
1826 #endif
1827
1828 e_inval:
1829 err = -EINVAL;
1830 goto out;
1831
1832 e_nobufs:
1833 err = -ENOBUFS;
1834 goto out;
1835
1836 martian_source:
1837 err = -EINVAL;
1838 martian_source_keep_err:
1839 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1840 goto out;
1841 }
1842
1843 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1844 u8 tos, struct net_device *dev)
1845 {
1846 int res;
1847
1848 rcu_read_lock();
1849
1850 /* Multicast recognition logic is moved from route cache to here.
1851 The problem was that too many Ethernet cards have broken/missing
1852 hardware multicast filters :-( As result the host on multicasting
1853 network acquires a lot of useless route cache entries, sort of
1854 SDR messages from all the world. Now we try to get rid of them.
1855 Really, provided software IP multicast filter is organized
1856 reasonably (at least, hashed), it does not result in a slowdown
1857 comparing with route cache reject entries.
1858 Note, that multicast routers are not affected, because
1859 route cache entry is created eventually.
1860 */
1861 if (ipv4_is_multicast(daddr)) {
1862 struct in_device *in_dev = __in_dev_get_rcu(dev);
1863
1864 if (in_dev) {
1865 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1866 ip_hdr(skb)->protocol);
1867 if (our
1868 #ifdef CONFIG_IP_MROUTE
1869 ||
1870 (!ipv4_is_local_multicast(daddr) &&
1871 IN_DEV_MFORWARD(in_dev))
1872 #endif
1873 ) {
1874 int res = ip_route_input_mc(skb, daddr, saddr,
1875 tos, dev, our);
1876 rcu_read_unlock();
1877 return res;
1878 }
1879 }
1880 rcu_read_unlock();
1881 return -EINVAL;
1882 }
1883 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1884 rcu_read_unlock();
1885 return res;
1886 }
1887 EXPORT_SYMBOL(ip_route_input_noref);
1888
1889 /* called with rcu_read_lock() */
1890 static struct rtable *__mkroute_output(const struct fib_result *res,
1891 const struct flowi4 *fl4, int orig_oif,
1892 struct net_device *dev_out,
1893 unsigned int flags)
1894 {
1895 struct fib_info *fi = res->fi;
1896 struct fib_nh_exception *fnhe;
1897 struct in_device *in_dev;
1898 u16 type = res->type;
1899 struct rtable *rth;
1900 bool do_cache;
1901
1902 in_dev = __in_dev_get_rcu(dev_out);
1903 if (!in_dev)
1904 return ERR_PTR(-EINVAL);
1905
1906 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1907 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1908 return ERR_PTR(-EINVAL);
1909
1910 if (ipv4_is_lbcast(fl4->daddr))
1911 type = RTN_BROADCAST;
1912 else if (ipv4_is_multicast(fl4->daddr))
1913 type = RTN_MULTICAST;
1914 else if (ipv4_is_zeronet(fl4->daddr))
1915 return ERR_PTR(-EINVAL);
1916
1917 if (dev_out->flags & IFF_LOOPBACK)
1918 flags |= RTCF_LOCAL;
1919
1920 do_cache = true;
1921 if (type == RTN_BROADCAST) {
1922 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1923 fi = NULL;
1924 } else if (type == RTN_MULTICAST) {
1925 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1926 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1927 fl4->flowi4_proto))
1928 flags &= ~RTCF_LOCAL;
1929 else
1930 do_cache = false;
1931 /* If multicast route do not exist use
1932 * default one, but do not gateway in this case.
1933 * Yes, it is hack.
1934 */
1935 if (fi && res->prefixlen < 4)
1936 fi = NULL;
1937 }
1938
1939 fnhe = NULL;
1940 do_cache &= fi != NULL;
1941 if (do_cache) {
1942 struct rtable __rcu **prth;
1943 struct fib_nh *nh = &FIB_RES_NH(*res);
1944
1945 fnhe = find_exception(nh, fl4->daddr);
1946 if (fnhe)
1947 prth = &fnhe->fnhe_rth_output;
1948 else {
1949 if (unlikely(fl4->flowi4_flags &
1950 FLOWI_FLAG_KNOWN_NH &&
1951 !(nh->nh_gw &&
1952 nh->nh_scope == RT_SCOPE_LINK))) {
1953 do_cache = false;
1954 goto add;
1955 }
1956 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
1957 }
1958 rth = rcu_dereference(*prth);
1959 if (rt_cache_valid(rth)) {
1960 dst_hold(&rth->dst);
1961 return rth;
1962 }
1963 }
1964
1965 add:
1966 rth = rt_dst_alloc(dev_out,
1967 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1968 IN_DEV_CONF_GET(in_dev, NOXFRM),
1969 do_cache);
1970 if (!rth)
1971 return ERR_PTR(-ENOBUFS);
1972
1973 rth->dst.output = ip_output;
1974
1975 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out));
1976 rth->rt_flags = flags;
1977 rth->rt_type = type;
1978 rth->rt_is_input = 0;
1979 rth->rt_iif = orig_oif ? : 0;
1980 rth->rt_pmtu = 0;
1981 rth->rt_gateway = 0;
1982 rth->rt_uses_gateway = 0;
1983 INIT_LIST_HEAD(&rth->rt_uncached);
1984
1985 RT_CACHE_STAT_INC(out_slow_tot);
1986
1987 if (flags & RTCF_LOCAL)
1988 rth->dst.input = ip_local_deliver;
1989 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1990 if (flags & RTCF_LOCAL &&
1991 !(dev_out->flags & IFF_LOOPBACK)) {
1992 rth->dst.output = ip_mc_output;
1993 RT_CACHE_STAT_INC(out_slow_mc);
1994 }
1995 #ifdef CONFIG_IP_MROUTE
1996 if (type == RTN_MULTICAST) {
1997 if (IN_DEV_MFORWARD(in_dev) &&
1998 !ipv4_is_local_multicast(fl4->daddr)) {
1999 rth->dst.input = ip_mr_input;
2000 rth->dst.output = ip_mc_output;
2001 }
2002 }
2003 #endif
2004 }
2005
2006 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
2007
2008 return rth;
2009 }
2010
2011 /*
2012 * Major route resolver routine.
2013 */
2014
2015 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
2016 {
2017 struct net_device *dev_out = NULL;
2018 __u8 tos = RT_FL_TOS(fl4);
2019 unsigned int flags = 0;
2020 struct fib_result res;
2021 struct rtable *rth;
2022 int orig_oif;
2023
2024 res.tclassid = 0;
2025 res.fi = NULL;
2026 res.table = NULL;
2027
2028 orig_oif = fl4->flowi4_oif;
2029
2030 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2031 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2032 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2033 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2034
2035 rcu_read_lock();
2036 if (fl4->saddr) {
2037 rth = ERR_PTR(-EINVAL);
2038 if (ipv4_is_multicast(fl4->saddr) ||
2039 ipv4_is_lbcast(fl4->saddr) ||
2040 ipv4_is_zeronet(fl4->saddr))
2041 goto out;
2042
2043 /* I removed check for oif == dev_out->oif here.
2044 It was wrong for two reasons:
2045 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2046 is assigned to multiple interfaces.
2047 2. Moreover, we are allowed to send packets with saddr
2048 of another iface. --ANK
2049 */
2050
2051 if (fl4->flowi4_oif == 0 &&
2052 (ipv4_is_multicast(fl4->daddr) ||
2053 ipv4_is_lbcast(fl4->daddr))) {
2054 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2055 dev_out = __ip_dev_find(net, fl4->saddr, false);
2056 if (dev_out == NULL)
2057 goto out;
2058
2059 /* Special hack: user can direct multicasts
2060 and limited broadcast via necessary interface
2061 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2062 This hack is not just for fun, it allows
2063 vic,vat and friends to work.
2064 They bind socket to loopback, set ttl to zero
2065 and expect that it will work.
2066 From the viewpoint of routing cache they are broken,
2067 because we are not allowed to build multicast path
2068 with loopback source addr (look, routing cache
2069 cannot know, that ttl is zero, so that packet
2070 will not leave this host and route is valid).
2071 Luckily, this hack is good workaround.
2072 */
2073
2074 fl4->flowi4_oif = dev_out->ifindex;
2075 goto make_route;
2076 }
2077
2078 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2079 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2080 if (!__ip_dev_find(net, fl4->saddr, false))
2081 goto out;
2082 }
2083 }
2084
2085
2086 if (fl4->flowi4_oif) {
2087 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2088 rth = ERR_PTR(-ENODEV);
2089 if (dev_out == NULL)
2090 goto out;
2091
2092 /* RACE: Check return value of inet_select_addr instead. */
2093 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2094 rth = ERR_PTR(-ENETUNREACH);
2095 goto out;
2096 }
2097 if (ipv4_is_local_multicast(fl4->daddr) ||
2098 ipv4_is_lbcast(fl4->daddr)) {
2099 if (!fl4->saddr)
2100 fl4->saddr = inet_select_addr(dev_out, 0,
2101 RT_SCOPE_LINK);
2102 goto make_route;
2103 }
2104 if (!fl4->saddr) {
2105 if (ipv4_is_multicast(fl4->daddr))
2106 fl4->saddr = inet_select_addr(dev_out, 0,
2107 fl4->flowi4_scope);
2108 else if (!fl4->daddr)
2109 fl4->saddr = inet_select_addr(dev_out, 0,
2110 RT_SCOPE_HOST);
2111 }
2112 }
2113
2114 if (!fl4->daddr) {
2115 fl4->daddr = fl4->saddr;
2116 if (!fl4->daddr)
2117 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2118 dev_out = net->loopback_dev;
2119 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2120 res.type = RTN_LOCAL;
2121 flags |= RTCF_LOCAL;
2122 goto make_route;
2123 }
2124
2125 if (fib_lookup(net, fl4, &res)) {
2126 res.fi = NULL;
2127 res.table = NULL;
2128 if (fl4->flowi4_oif) {
2129 /* Apparently, routing tables are wrong. Assume,
2130 that the destination is on link.
2131
2132 WHY? DW.
2133 Because we are allowed to send to iface
2134 even if it has NO routes and NO assigned
2135 addresses. When oif is specified, routing
2136 tables are looked up with only one purpose:
2137 to catch if destination is gatewayed, rather than
2138 direct. Moreover, if MSG_DONTROUTE is set,
2139 we send packet, ignoring both routing tables
2140 and ifaddr state. --ANK
2141
2142
2143 We could make it even if oif is unknown,
2144 likely IPv6, but we do not.
2145 */
2146
2147 if (fl4->saddr == 0)
2148 fl4->saddr = inet_select_addr(dev_out, 0,
2149 RT_SCOPE_LINK);
2150 res.type = RTN_UNICAST;
2151 goto make_route;
2152 }
2153 rth = ERR_PTR(-ENETUNREACH);
2154 goto out;
2155 }
2156
2157 if (res.type == RTN_LOCAL) {
2158 if (!fl4->saddr) {
2159 if (res.fi->fib_prefsrc)
2160 fl4->saddr = res.fi->fib_prefsrc;
2161 else
2162 fl4->saddr = fl4->daddr;
2163 }
2164 dev_out = net->loopback_dev;
2165 fl4->flowi4_oif = dev_out->ifindex;
2166 flags |= RTCF_LOCAL;
2167 goto make_route;
2168 }
2169
2170 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2171 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2172 fib_select_multipath(&res);
2173 else
2174 #endif
2175 if (!res.prefixlen &&
2176 res.table->tb_num_default > 1 &&
2177 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2178 fib_select_default(&res);
2179
2180 if (!fl4->saddr)
2181 fl4->saddr = FIB_RES_PREFSRC(net, res);
2182
2183 dev_out = FIB_RES_DEV(res);
2184 fl4->flowi4_oif = dev_out->ifindex;
2185
2186
2187 make_route:
2188 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2189
2190 out:
2191 rcu_read_unlock();
2192 return rth;
2193 }
2194 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2195
2196 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2197 {
2198 return NULL;
2199 }
2200
2201 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2202 {
2203 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2204
2205 return mtu ? : dst->dev->mtu;
2206 }
2207
2208 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2209 struct sk_buff *skb, u32 mtu)
2210 {
2211 }
2212
2213 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2214 struct sk_buff *skb)
2215 {
2216 }
2217
2218 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2219 unsigned long old)
2220 {
2221 return NULL;
2222 }
2223
2224 static struct dst_ops ipv4_dst_blackhole_ops = {
2225 .family = AF_INET,
2226 .protocol = cpu_to_be16(ETH_P_IP),
2227 .check = ipv4_blackhole_dst_check,
2228 .mtu = ipv4_blackhole_mtu,
2229 .default_advmss = ipv4_default_advmss,
2230 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2231 .redirect = ipv4_rt_blackhole_redirect,
2232 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2233 .neigh_lookup = ipv4_neigh_lookup,
2234 };
2235
2236 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2237 {
2238 struct rtable *ort = (struct rtable *) dst_orig;
2239 struct rtable *rt;
2240
2241 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2242 if (rt) {
2243 struct dst_entry *new = &rt->dst;
2244
2245 new->__use = 1;
2246 new->input = dst_discard;
2247 new->output = dst_discard_sk;
2248
2249 new->dev = ort->dst.dev;
2250 if (new->dev)
2251 dev_hold(new->dev);
2252
2253 rt->rt_is_input = ort->rt_is_input;
2254 rt->rt_iif = ort->rt_iif;
2255 rt->rt_pmtu = ort->rt_pmtu;
2256
2257 rt->rt_genid = rt_genid_ipv4(net);
2258 rt->rt_flags = ort->rt_flags;
2259 rt->rt_type = ort->rt_type;
2260 rt->rt_gateway = ort->rt_gateway;
2261 rt->rt_uses_gateway = ort->rt_uses_gateway;
2262
2263 INIT_LIST_HEAD(&rt->rt_uncached);
2264
2265 dst_free(new);
2266 }
2267
2268 dst_release(dst_orig);
2269
2270 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2271 }
2272
2273 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2274 struct sock *sk)
2275 {
2276 struct rtable *rt = __ip_route_output_key(net, flp4);
2277
2278 if (IS_ERR(rt))
2279 return rt;
2280
2281 if (flp4->flowi4_proto)
2282 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2283 flowi4_to_flowi(flp4),
2284 sk, 0);
2285
2286 return rt;
2287 }
2288 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2289
2290 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2291 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2292 u32 seq, int event, int nowait, unsigned int flags)
2293 {
2294 struct rtable *rt = skb_rtable(skb);
2295 struct rtmsg *r;
2296 struct nlmsghdr *nlh;
2297 unsigned long expires = 0;
2298 u32 error;
2299 u32 metrics[RTAX_MAX];
2300
2301 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2302 if (nlh == NULL)
2303 return -EMSGSIZE;
2304
2305 r = nlmsg_data(nlh);
2306 r->rtm_family = AF_INET;
2307 r->rtm_dst_len = 32;
2308 r->rtm_src_len = 0;
2309 r->rtm_tos = fl4->flowi4_tos;
2310 r->rtm_table = RT_TABLE_MAIN;
2311 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2312 goto nla_put_failure;
2313 r->rtm_type = rt->rt_type;
2314 r->rtm_scope = RT_SCOPE_UNIVERSE;
2315 r->rtm_protocol = RTPROT_UNSPEC;
2316 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2317 if (rt->rt_flags & RTCF_NOTIFY)
2318 r->rtm_flags |= RTM_F_NOTIFY;
2319
2320 if (nla_put_be32(skb, RTA_DST, dst))
2321 goto nla_put_failure;
2322 if (src) {
2323 r->rtm_src_len = 32;
2324 if (nla_put_be32(skb, RTA_SRC, src))
2325 goto nla_put_failure;
2326 }
2327 if (rt->dst.dev &&
2328 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2329 goto nla_put_failure;
2330 #ifdef CONFIG_IP_ROUTE_CLASSID
2331 if (rt->dst.tclassid &&
2332 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2333 goto nla_put_failure;
2334 #endif
2335 if (!rt_is_input_route(rt) &&
2336 fl4->saddr != src) {
2337 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2338 goto nla_put_failure;
2339 }
2340 if (rt->rt_uses_gateway &&
2341 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2342 goto nla_put_failure;
2343
2344 expires = rt->dst.expires;
2345 if (expires) {
2346 unsigned long now = jiffies;
2347
2348 if (time_before(now, expires))
2349 expires -= now;
2350 else
2351 expires = 0;
2352 }
2353
2354 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2355 if (rt->rt_pmtu && expires)
2356 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2357 if (rtnetlink_put_metrics(skb, metrics) < 0)
2358 goto nla_put_failure;
2359
2360 if (fl4->flowi4_mark &&
2361 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2362 goto nla_put_failure;
2363
2364 error = rt->dst.error;
2365
2366 if (rt_is_input_route(rt)) {
2367 #ifdef CONFIG_IP_MROUTE
2368 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2369 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2370 int err = ipmr_get_route(net, skb,
2371 fl4->saddr, fl4->daddr,
2372 r, nowait);
2373 if (err <= 0) {
2374 if (!nowait) {
2375 if (err == 0)
2376 return 0;
2377 goto nla_put_failure;
2378 } else {
2379 if (err == -EMSGSIZE)
2380 goto nla_put_failure;
2381 error = err;
2382 }
2383 }
2384 } else
2385 #endif
2386 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2387 goto nla_put_failure;
2388 }
2389
2390 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2391 goto nla_put_failure;
2392
2393 nlmsg_end(skb, nlh);
2394 return 0;
2395
2396 nla_put_failure:
2397 nlmsg_cancel(skb, nlh);
2398 return -EMSGSIZE;
2399 }
2400
2401 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2402 {
2403 struct net *net = sock_net(in_skb->sk);
2404 struct rtmsg *rtm;
2405 struct nlattr *tb[RTA_MAX+1];
2406 struct rtable *rt = NULL;
2407 struct flowi4 fl4;
2408 __be32 dst = 0;
2409 __be32 src = 0;
2410 u32 iif;
2411 int err;
2412 int mark;
2413 struct sk_buff *skb;
2414
2415 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2416 if (err < 0)
2417 goto errout;
2418
2419 rtm = nlmsg_data(nlh);
2420
2421 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2422 if (skb == NULL) {
2423 err = -ENOBUFS;
2424 goto errout;
2425 }
2426
2427 /* Reserve room for dummy headers, this skb can pass
2428 through good chunk of routing engine.
2429 */
2430 skb_reset_mac_header(skb);
2431 skb_reset_network_header(skb);
2432
2433 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2434 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2435 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2436
2437 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2438 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2439 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2440 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2441
2442 memset(&fl4, 0, sizeof(fl4));
2443 fl4.daddr = dst;
2444 fl4.saddr = src;
2445 fl4.flowi4_tos = rtm->rtm_tos;
2446 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2447 fl4.flowi4_mark = mark;
2448
2449 if (iif) {
2450 struct net_device *dev;
2451
2452 dev = __dev_get_by_index(net, iif);
2453 if (dev == NULL) {
2454 err = -ENODEV;
2455 goto errout_free;
2456 }
2457
2458 skb->protocol = htons(ETH_P_IP);
2459 skb->dev = dev;
2460 skb->mark = mark;
2461 local_bh_disable();
2462 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2463 local_bh_enable();
2464
2465 rt = skb_rtable(skb);
2466 if (err == 0 && rt->dst.error)
2467 err = -rt->dst.error;
2468 } else {
2469 rt = ip_route_output_key(net, &fl4);
2470
2471 err = 0;
2472 if (IS_ERR(rt))
2473 err = PTR_ERR(rt);
2474 }
2475
2476 if (err)
2477 goto errout_free;
2478
2479 skb_dst_set(skb, &rt->dst);
2480 if (rtm->rtm_flags & RTM_F_NOTIFY)
2481 rt->rt_flags |= RTCF_NOTIFY;
2482
2483 err = rt_fill_info(net, dst, src, &fl4, skb,
2484 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2485 RTM_NEWROUTE, 0, 0);
2486 if (err < 0)
2487 goto errout_free;
2488
2489 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2490 errout:
2491 return err;
2492
2493 errout_free:
2494 kfree_skb(skb);
2495 goto errout;
2496 }
2497
2498 void ip_rt_multicast_event(struct in_device *in_dev)
2499 {
2500 rt_cache_flush(dev_net(in_dev->dev));
2501 }
2502
2503 #ifdef CONFIG_SYSCTL
2504 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2505 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2506 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2507 static int ip_rt_gc_elasticity __read_mostly = 8;
2508
2509 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2510 void __user *buffer,
2511 size_t *lenp, loff_t *ppos)
2512 {
2513 struct net *net = (struct net *)__ctl->extra1;
2514
2515 if (write) {
2516 rt_cache_flush(net);
2517 fnhe_genid_bump(net);
2518 return 0;
2519 }
2520
2521 return -EINVAL;
2522 }
2523
2524 static struct ctl_table ipv4_route_table[] = {
2525 {
2526 .procname = "gc_thresh",
2527 .data = &ipv4_dst_ops.gc_thresh,
2528 .maxlen = sizeof(int),
2529 .mode = 0644,
2530 .proc_handler = proc_dointvec,
2531 },
2532 {
2533 .procname = "max_size",
2534 .data = &ip_rt_max_size,
2535 .maxlen = sizeof(int),
2536 .mode = 0644,
2537 .proc_handler = proc_dointvec,
2538 },
2539 {
2540 /* Deprecated. Use gc_min_interval_ms */
2541
2542 .procname = "gc_min_interval",
2543 .data = &ip_rt_gc_min_interval,
2544 .maxlen = sizeof(int),
2545 .mode = 0644,
2546 .proc_handler = proc_dointvec_jiffies,
2547 },
2548 {
2549 .procname = "gc_min_interval_ms",
2550 .data = &ip_rt_gc_min_interval,
2551 .maxlen = sizeof(int),
2552 .mode = 0644,
2553 .proc_handler = proc_dointvec_ms_jiffies,
2554 },
2555 {
2556 .procname = "gc_timeout",
2557 .data = &ip_rt_gc_timeout,
2558 .maxlen = sizeof(int),
2559 .mode = 0644,
2560 .proc_handler = proc_dointvec_jiffies,
2561 },
2562 {
2563 .procname = "gc_interval",
2564 .data = &ip_rt_gc_interval,
2565 .maxlen = sizeof(int),
2566 .mode = 0644,
2567 .proc_handler = proc_dointvec_jiffies,
2568 },
2569 {
2570 .procname = "redirect_load",
2571 .data = &ip_rt_redirect_load,
2572 .maxlen = sizeof(int),
2573 .mode = 0644,
2574 .proc_handler = proc_dointvec,
2575 },
2576 {
2577 .procname = "redirect_number",
2578 .data = &ip_rt_redirect_number,
2579 .maxlen = sizeof(int),
2580 .mode = 0644,
2581 .proc_handler = proc_dointvec,
2582 },
2583 {
2584 .procname = "redirect_silence",
2585 .data = &ip_rt_redirect_silence,
2586 .maxlen = sizeof(int),
2587 .mode = 0644,
2588 .proc_handler = proc_dointvec,
2589 },
2590 {
2591 .procname = "error_cost",
2592 .data = &ip_rt_error_cost,
2593 .maxlen = sizeof(int),
2594 .mode = 0644,
2595 .proc_handler = proc_dointvec,
2596 },
2597 {
2598 .procname = "error_burst",
2599 .data = &ip_rt_error_burst,
2600 .maxlen = sizeof(int),
2601 .mode = 0644,
2602 .proc_handler = proc_dointvec,
2603 },
2604 {
2605 .procname = "gc_elasticity",
2606 .data = &ip_rt_gc_elasticity,
2607 .maxlen = sizeof(int),
2608 .mode = 0644,
2609 .proc_handler = proc_dointvec,
2610 },
2611 {
2612 .procname = "mtu_expires",
2613 .data = &ip_rt_mtu_expires,
2614 .maxlen = sizeof(int),
2615 .mode = 0644,
2616 .proc_handler = proc_dointvec_jiffies,
2617 },
2618 {
2619 .procname = "min_pmtu",
2620 .data = &ip_rt_min_pmtu,
2621 .maxlen = sizeof(int),
2622 .mode = 0644,
2623 .proc_handler = proc_dointvec,
2624 },
2625 {
2626 .procname = "min_adv_mss",
2627 .data = &ip_rt_min_advmss,
2628 .maxlen = sizeof(int),
2629 .mode = 0644,
2630 .proc_handler = proc_dointvec,
2631 },
2632 { }
2633 };
2634
2635 static struct ctl_table ipv4_route_flush_table[] = {
2636 {
2637 .procname = "flush",
2638 .maxlen = sizeof(int),
2639 .mode = 0200,
2640 .proc_handler = ipv4_sysctl_rtcache_flush,
2641 },
2642 { },
2643 };
2644
2645 static __net_init int sysctl_route_net_init(struct net *net)
2646 {
2647 struct ctl_table *tbl;
2648
2649 tbl = ipv4_route_flush_table;
2650 if (!net_eq(net, &init_net)) {
2651 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2652 if (tbl == NULL)
2653 goto err_dup;
2654
2655 /* Don't export sysctls to unprivileged users */
2656 if (net->user_ns != &init_user_ns)
2657 tbl[0].procname = NULL;
2658 }
2659 tbl[0].extra1 = net;
2660
2661 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2662 if (net->ipv4.route_hdr == NULL)
2663 goto err_reg;
2664 return 0;
2665
2666 err_reg:
2667 if (tbl != ipv4_route_flush_table)
2668 kfree(tbl);
2669 err_dup:
2670 return -ENOMEM;
2671 }
2672
2673 static __net_exit void sysctl_route_net_exit(struct net *net)
2674 {
2675 struct ctl_table *tbl;
2676
2677 tbl = net->ipv4.route_hdr->ctl_table_arg;
2678 unregister_net_sysctl_table(net->ipv4.route_hdr);
2679 BUG_ON(tbl == ipv4_route_flush_table);
2680 kfree(tbl);
2681 }
2682
2683 static __net_initdata struct pernet_operations sysctl_route_ops = {
2684 .init = sysctl_route_net_init,
2685 .exit = sysctl_route_net_exit,
2686 };
2687 #endif
2688
2689 static __net_init int rt_genid_init(struct net *net)
2690 {
2691 atomic_set(&net->ipv4.rt_genid, 0);
2692 atomic_set(&net->fnhe_genid, 0);
2693 get_random_bytes(&net->ipv4.dev_addr_genid,
2694 sizeof(net->ipv4.dev_addr_genid));
2695 return 0;
2696 }
2697
2698 static __net_initdata struct pernet_operations rt_genid_ops = {
2699 .init = rt_genid_init,
2700 };
2701
2702 static int __net_init ipv4_inetpeer_init(struct net *net)
2703 {
2704 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2705
2706 if (!bp)
2707 return -ENOMEM;
2708 inet_peer_base_init(bp);
2709 net->ipv4.peers = bp;
2710 return 0;
2711 }
2712
2713 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2714 {
2715 struct inet_peer_base *bp = net->ipv4.peers;
2716
2717 net->ipv4.peers = NULL;
2718 inetpeer_invalidate_tree(bp);
2719 kfree(bp);
2720 }
2721
2722 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2723 .init = ipv4_inetpeer_init,
2724 .exit = ipv4_inetpeer_exit,
2725 };
2726
2727 #ifdef CONFIG_IP_ROUTE_CLASSID
2728 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2729 #endif /* CONFIG_IP_ROUTE_CLASSID */
2730
2731 int __init ip_rt_init(void)
2732 {
2733 int rc = 0;
2734 int cpu;
2735
2736 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2737 if (!ip_idents)
2738 panic("IP: failed to allocate ip_idents\n");
2739
2740 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2741
2742 for_each_possible_cpu(cpu) {
2743 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
2744
2745 INIT_LIST_HEAD(&ul->head);
2746 spin_lock_init(&ul->lock);
2747 }
2748 #ifdef CONFIG_IP_ROUTE_CLASSID
2749 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2750 if (!ip_rt_acct)
2751 panic("IP: failed to allocate ip_rt_acct\n");
2752 #endif
2753
2754 ipv4_dst_ops.kmem_cachep =
2755 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2756 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2757
2758 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2759
2760 if (dst_entries_init(&ipv4_dst_ops) < 0)
2761 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2762
2763 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2764 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2765
2766 ipv4_dst_ops.gc_thresh = ~0;
2767 ip_rt_max_size = INT_MAX;
2768
2769 devinet_init();
2770 ip_fib_init();
2771
2772 if (ip_rt_proc_init())
2773 pr_err("Unable to create route proc files\n");
2774 #ifdef CONFIG_XFRM
2775 xfrm_init();
2776 xfrm4_init();
2777 #endif
2778 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2779
2780 #ifdef CONFIG_SYSCTL
2781 register_pernet_subsys(&sysctl_route_ops);
2782 #endif
2783 register_pernet_subsys(&rt_genid_ops);
2784 register_pernet_subsys(&ipv4_inetpeer_ops);
2785 return rc;
2786 }
2787
2788 #ifdef CONFIG_SYSCTL
2789 /*
2790 * We really need to sanitize the damn ipv4 init order, then all
2791 * this nonsense will go away.
2792 */
2793 void __init ip_static_sysctl_init(void)
2794 {
2795 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2796 }
2797 #endif
Linux kernel - Deliverables
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