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[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/dst_metadata.h>
95 #include <net/net_namespace.h>
96 #include <net/protocol.h>
97 #include <net/ip.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
102 #include <net/arp.h>
103 #include <net/tcp.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/lwtunnel.h>
107 #include <net/netevent.h>
108 #include <net/rtnetlink.h>
109 #ifdef CONFIG_SYSCTL
110 #include <linux/sysctl.h>
111 #include <linux/kmemleak.h>
112 #endif
113 #include <net/secure_seq.h>
114 #include <net/ip_tunnels.h>
115 #include <net/l3mdev.h>
116
117 #define RT_FL_TOS(oldflp4) \
118 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
119
120 #define RT_GC_TIMEOUT (300*HZ)
121
122 static int ip_rt_max_size;
123 static int ip_rt_redirect_number __read_mostly = 9;
124 static int ip_rt_redirect_load __read_mostly = HZ / 50;
125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly = HZ;
127 static int ip_rt_error_burst __read_mostly = 5 * HZ;
128 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
129 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
130 static int ip_rt_min_advmss __read_mostly = 256;
131
132 /*
133 * Interface to generic destination cache.
134 */
135
136 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
137 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
138 static unsigned int ipv4_mtu(const struct dst_entry *dst);
139 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
140 static void ipv4_link_failure(struct sk_buff *skb);
141 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
142 struct sk_buff *skb, u32 mtu);
143 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
144 struct sk_buff *skb);
145 static void ipv4_dst_destroy(struct dst_entry *dst);
146
147 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
148 {
149 WARN_ON(1);
150 return NULL;
151 }
152
153 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
154 struct sk_buff *skb,
155 const void *daddr);
156
157 static struct dst_ops ipv4_dst_ops = {
158 .family = AF_INET,
159 .check = ipv4_dst_check,
160 .default_advmss = ipv4_default_advmss,
161 .mtu = ipv4_mtu,
162 .cow_metrics = ipv4_cow_metrics,
163 .destroy = ipv4_dst_destroy,
164 .negative_advice = ipv4_negative_advice,
165 .link_failure = ipv4_link_failure,
166 .update_pmtu = ip_rt_update_pmtu,
167 .redirect = ip_do_redirect,
168 .local_out = __ip_local_out,
169 .neigh_lookup = ipv4_neigh_lookup,
170 };
171
172 #define ECN_OR_COST(class) TC_PRIO_##class
173
174 const __u8 ip_tos2prio[16] = {
175 TC_PRIO_BESTEFFORT,
176 ECN_OR_COST(BESTEFFORT),
177 TC_PRIO_BESTEFFORT,
178 ECN_OR_COST(BESTEFFORT),
179 TC_PRIO_BULK,
180 ECN_OR_COST(BULK),
181 TC_PRIO_BULK,
182 ECN_OR_COST(BULK),
183 TC_PRIO_INTERACTIVE,
184 ECN_OR_COST(INTERACTIVE),
185 TC_PRIO_INTERACTIVE,
186 ECN_OR_COST(INTERACTIVE),
187 TC_PRIO_INTERACTIVE_BULK,
188 ECN_OR_COST(INTERACTIVE_BULK),
189 TC_PRIO_INTERACTIVE_BULK,
190 ECN_OR_COST(INTERACTIVE_BULK)
191 };
192 EXPORT_SYMBOL(ip_tos2prio);
193
194 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
195 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
196
197 #ifdef CONFIG_PROC_FS
198 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
199 {
200 if (*pos)
201 return NULL;
202 return SEQ_START_TOKEN;
203 }
204
205 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
206 {
207 ++*pos;
208 return NULL;
209 }
210
211 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
212 {
213 }
214
215 static int rt_cache_seq_show(struct seq_file *seq, void *v)
216 {
217 if (v == SEQ_START_TOKEN)
218 seq_printf(seq, "%-127s\n",
219 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
220 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
221 "HHUptod\tSpecDst");
222 return 0;
223 }
224
225 static const struct seq_operations rt_cache_seq_ops = {
226 .start = rt_cache_seq_start,
227 .next = rt_cache_seq_next,
228 .stop = rt_cache_seq_stop,
229 .show = rt_cache_seq_show,
230 };
231
232 static int rt_cache_seq_open(struct inode *inode, struct file *file)
233 {
234 return seq_open(file, &rt_cache_seq_ops);
235 }
236
237 static const struct file_operations rt_cache_seq_fops = {
238 .owner = THIS_MODULE,
239 .open = rt_cache_seq_open,
240 .read = seq_read,
241 .llseek = seq_lseek,
242 .release = seq_release,
243 };
244
245
246 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
247 {
248 int cpu;
249
250 if (*pos == 0)
251 return SEQ_START_TOKEN;
252
253 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
254 if (!cpu_possible(cpu))
255 continue;
256 *pos = cpu+1;
257 return &per_cpu(rt_cache_stat, cpu);
258 }
259 return NULL;
260 }
261
262 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
263 {
264 int cpu;
265
266 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
267 if (!cpu_possible(cpu))
268 continue;
269 *pos = cpu+1;
270 return &per_cpu(rt_cache_stat, cpu);
271 }
272 return NULL;
273
274 }
275
276 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
277 {
278
279 }
280
281 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
282 {
283 struct rt_cache_stat *st = v;
284
285 if (v == SEQ_START_TOKEN) {
286 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");
287 return 0;
288 }
289
290 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
291 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
292 dst_entries_get_slow(&ipv4_dst_ops),
293 0, /* st->in_hit */
294 st->in_slow_tot,
295 st->in_slow_mc,
296 st->in_no_route,
297 st->in_brd,
298 st->in_martian_dst,
299 st->in_martian_src,
300
301 0, /* st->out_hit */
302 st->out_slow_tot,
303 st->out_slow_mc,
304
305 0, /* st->gc_total */
306 0, /* st->gc_ignored */
307 0, /* st->gc_goal_miss */
308 0, /* st->gc_dst_overflow */
309 0, /* st->in_hlist_search */
310 0 /* st->out_hlist_search */
311 );
312 return 0;
313 }
314
315 static const struct seq_operations rt_cpu_seq_ops = {
316 .start = rt_cpu_seq_start,
317 .next = rt_cpu_seq_next,
318 .stop = rt_cpu_seq_stop,
319 .show = rt_cpu_seq_show,
320 };
321
322
323 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
324 {
325 return seq_open(file, &rt_cpu_seq_ops);
326 }
327
328 static const struct file_operations rt_cpu_seq_fops = {
329 .owner = THIS_MODULE,
330 .open = rt_cpu_seq_open,
331 .read = seq_read,
332 .llseek = seq_lseek,
333 .release = seq_release,
334 };
335
336 #ifdef CONFIG_IP_ROUTE_CLASSID
337 static int rt_acct_proc_show(struct seq_file *m, void *v)
338 {
339 struct ip_rt_acct *dst, *src;
340 unsigned int i, j;
341
342 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
343 if (!dst)
344 return -ENOMEM;
345
346 for_each_possible_cpu(i) {
347 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
348 for (j = 0; j < 256; j++) {
349 dst[j].o_bytes += src[j].o_bytes;
350 dst[j].o_packets += src[j].o_packets;
351 dst[j].i_bytes += src[j].i_bytes;
352 dst[j].i_packets += src[j].i_packets;
353 }
354 }
355
356 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
357 kfree(dst);
358 return 0;
359 }
360
361 static int rt_acct_proc_open(struct inode *inode, struct file *file)
362 {
363 return single_open(file, rt_acct_proc_show, NULL);
364 }
365
366 static const struct file_operations rt_acct_proc_fops = {
367 .owner = THIS_MODULE,
368 .open = rt_acct_proc_open,
369 .read = seq_read,
370 .llseek = seq_lseek,
371 .release = single_release,
372 };
373 #endif
374
375 static int __net_init ip_rt_do_proc_init(struct net *net)
376 {
377 struct proc_dir_entry *pde;
378
379 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
380 &rt_cache_seq_fops);
381 if (!pde)
382 goto err1;
383
384 pde = proc_create("rt_cache", S_IRUGO,
385 net->proc_net_stat, &rt_cpu_seq_fops);
386 if (!pde)
387 goto err2;
388
389 #ifdef CONFIG_IP_ROUTE_CLASSID
390 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
391 if (!pde)
392 goto err3;
393 #endif
394 return 0;
395
396 #ifdef CONFIG_IP_ROUTE_CLASSID
397 err3:
398 remove_proc_entry("rt_cache", net->proc_net_stat);
399 #endif
400 err2:
401 remove_proc_entry("rt_cache", net->proc_net);
402 err1:
403 return -ENOMEM;
404 }
405
406 static void __net_exit ip_rt_do_proc_exit(struct net *net)
407 {
408 remove_proc_entry("rt_cache", net->proc_net_stat);
409 remove_proc_entry("rt_cache", net->proc_net);
410 #ifdef CONFIG_IP_ROUTE_CLASSID
411 remove_proc_entry("rt_acct", net->proc_net);
412 #endif
413 }
414
415 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
416 .init = ip_rt_do_proc_init,
417 .exit = ip_rt_do_proc_exit,
418 };
419
420 static int __init ip_rt_proc_init(void)
421 {
422 return register_pernet_subsys(&ip_rt_proc_ops);
423 }
424
425 #else
426 static inline int ip_rt_proc_init(void)
427 {
428 return 0;
429 }
430 #endif /* CONFIG_PROC_FS */
431
432 static inline bool rt_is_expired(const struct rtable *rth)
433 {
434 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
435 }
436
437 void rt_cache_flush(struct net *net)
438 {
439 rt_genid_bump_ipv4(net);
440 }
441
442 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
443 struct sk_buff *skb,
444 const void *daddr)
445 {
446 struct net_device *dev = dst->dev;
447 const __be32 *pkey = daddr;
448 const struct rtable *rt;
449 struct neighbour *n;
450
451 rt = (const struct rtable *) dst;
452 if (rt->rt_gateway)
453 pkey = (const __be32 *) &rt->rt_gateway;
454 else if (skb)
455 pkey = &ip_hdr(skb)->daddr;
456
457 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
458 if (n)
459 return n;
460 return neigh_create(&arp_tbl, pkey, dev);
461 }
462
463 #define IP_IDENTS_SZ 2048u
464
465 static atomic_t *ip_idents __read_mostly;
466 static u32 *ip_tstamps __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 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
475 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
476 u32 old = ACCESS_ONCE(*p_tstamp);
477 u32 now = (u32)jiffies;
478 u32 delta = 0;
479
480 if (old != now && cmpxchg(p_tstamp, old, now) == old)
481 delta = prandom_u32_max(now - old);
482
483 return atomic_add_return(segs + delta, p_id) - segs;
484 }
485 EXPORT_SYMBOL(ip_idents_reserve);
486
487 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
488 {
489 static u32 ip_idents_hashrnd __read_mostly;
490 u32 hash, id;
491
492 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
493
494 hash = jhash_3words((__force u32)iph->daddr,
495 (__force u32)iph->saddr,
496 iph->protocol ^ net_hash_mix(net),
497 ip_idents_hashrnd);
498 id = ip_idents_reserve(hash, segs);
499 iph->id = htons(id);
500 }
501 EXPORT_SYMBOL(__ip_select_ident);
502
503 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
504 const struct iphdr *iph,
505 int oif, u8 tos,
506 u8 prot, u32 mark, int flow_flags)
507 {
508 if (sk) {
509 const struct inet_sock *inet = inet_sk(sk);
510
511 oif = sk->sk_bound_dev_if;
512 mark = sk->sk_mark;
513 tos = RT_CONN_FLAGS(sk);
514 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
515 }
516 flowi4_init_output(fl4, oif, mark, tos,
517 RT_SCOPE_UNIVERSE, prot,
518 flow_flags,
519 iph->daddr, iph->saddr, 0, 0);
520 }
521
522 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
523 const struct sock *sk)
524 {
525 const struct iphdr *iph = ip_hdr(skb);
526 int oif = skb->dev->ifindex;
527 u8 tos = RT_TOS(iph->tos);
528 u8 prot = iph->protocol;
529 u32 mark = skb->mark;
530
531 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
532 }
533
534 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
535 {
536 const struct inet_sock *inet = inet_sk(sk);
537 const struct ip_options_rcu *inet_opt;
538 __be32 daddr = inet->inet_daddr;
539
540 rcu_read_lock();
541 inet_opt = rcu_dereference(inet->inet_opt);
542 if (inet_opt && inet_opt->opt.srr)
543 daddr = inet_opt->opt.faddr;
544 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
545 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
546 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
547 inet_sk_flowi_flags(sk),
548 daddr, inet->inet_saddr, 0, 0);
549 rcu_read_unlock();
550 }
551
552 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
553 const struct sk_buff *skb)
554 {
555 if (skb)
556 build_skb_flow_key(fl4, skb, sk);
557 else
558 build_sk_flow_key(fl4, sk);
559 }
560
561 static inline void rt_free(struct rtable *rt)
562 {
563 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
564 }
565
566 static DEFINE_SPINLOCK(fnhe_lock);
567
568 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
569 {
570 struct rtable *rt;
571
572 rt = rcu_dereference(fnhe->fnhe_rth_input);
573 if (rt) {
574 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
575 rt_free(rt);
576 }
577 rt = rcu_dereference(fnhe->fnhe_rth_output);
578 if (rt) {
579 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
580 rt_free(rt);
581 }
582 }
583
584 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
585 {
586 struct fib_nh_exception *fnhe, *oldest;
587
588 oldest = rcu_dereference(hash->chain);
589 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
590 fnhe = rcu_dereference(fnhe->fnhe_next)) {
591 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
592 oldest = fnhe;
593 }
594 fnhe_flush_routes(oldest);
595 return oldest;
596 }
597
598 static inline u32 fnhe_hashfun(__be32 daddr)
599 {
600 static u32 fnhe_hashrnd __read_mostly;
601 u32 hval;
602
603 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
604 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
605 return hash_32(hval, FNHE_HASH_SHIFT);
606 }
607
608 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
609 {
610 rt->rt_pmtu = fnhe->fnhe_pmtu;
611 rt->dst.expires = fnhe->fnhe_expires;
612
613 if (fnhe->fnhe_gw) {
614 rt->rt_flags |= RTCF_REDIRECTED;
615 rt->rt_gateway = fnhe->fnhe_gw;
616 rt->rt_uses_gateway = 1;
617 }
618 }
619
620 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
621 u32 pmtu, unsigned long expires)
622 {
623 struct fnhe_hash_bucket *hash;
624 struct fib_nh_exception *fnhe;
625 struct rtable *rt;
626 unsigned int i;
627 int depth;
628 u32 hval = fnhe_hashfun(daddr);
629
630 spin_lock_bh(&fnhe_lock);
631
632 hash = rcu_dereference(nh->nh_exceptions);
633 if (!hash) {
634 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
635 if (!hash)
636 goto out_unlock;
637 rcu_assign_pointer(nh->nh_exceptions, hash);
638 }
639
640 hash += hval;
641
642 depth = 0;
643 for (fnhe = rcu_dereference(hash->chain); fnhe;
644 fnhe = rcu_dereference(fnhe->fnhe_next)) {
645 if (fnhe->fnhe_daddr == daddr)
646 break;
647 depth++;
648 }
649
650 if (fnhe) {
651 if (gw)
652 fnhe->fnhe_gw = gw;
653 if (pmtu) {
654 fnhe->fnhe_pmtu = pmtu;
655 fnhe->fnhe_expires = max(1UL, expires);
656 }
657 /* Update all cached dsts too */
658 rt = rcu_dereference(fnhe->fnhe_rth_input);
659 if (rt)
660 fill_route_from_fnhe(rt, fnhe);
661 rt = rcu_dereference(fnhe->fnhe_rth_output);
662 if (rt)
663 fill_route_from_fnhe(rt, fnhe);
664 } else {
665 if (depth > FNHE_RECLAIM_DEPTH)
666 fnhe = fnhe_oldest(hash);
667 else {
668 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
669 if (!fnhe)
670 goto out_unlock;
671
672 fnhe->fnhe_next = hash->chain;
673 rcu_assign_pointer(hash->chain, fnhe);
674 }
675 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
676 fnhe->fnhe_daddr = daddr;
677 fnhe->fnhe_gw = gw;
678 fnhe->fnhe_pmtu = pmtu;
679 fnhe->fnhe_expires = expires;
680
681 /* Exception created; mark the cached routes for the nexthop
682 * stale, so anyone caching it rechecks if this exception
683 * applies to them.
684 */
685 rt = rcu_dereference(nh->nh_rth_input);
686 if (rt)
687 rt->dst.obsolete = DST_OBSOLETE_KILL;
688
689 for_each_possible_cpu(i) {
690 struct rtable __rcu **prt;
691 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
692 rt = rcu_dereference(*prt);
693 if (rt)
694 rt->dst.obsolete = DST_OBSOLETE_KILL;
695 }
696 }
697
698 fnhe->fnhe_stamp = jiffies;
699
700 out_unlock:
701 spin_unlock_bh(&fnhe_lock);
702 }
703
704 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
705 bool kill_route)
706 {
707 __be32 new_gw = icmp_hdr(skb)->un.gateway;
708 __be32 old_gw = ip_hdr(skb)->saddr;
709 struct net_device *dev = skb->dev;
710 struct in_device *in_dev;
711 struct fib_result res;
712 struct neighbour *n;
713 struct net *net;
714
715 switch (icmp_hdr(skb)->code & 7) {
716 case ICMP_REDIR_NET:
717 case ICMP_REDIR_NETTOS:
718 case ICMP_REDIR_HOST:
719 case ICMP_REDIR_HOSTTOS:
720 break;
721
722 default:
723 return;
724 }
725
726 if (rt->rt_gateway != old_gw)
727 return;
728
729 in_dev = __in_dev_get_rcu(dev);
730 if (!in_dev)
731 return;
732
733 net = dev_net(dev);
734 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
735 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
736 ipv4_is_zeronet(new_gw))
737 goto reject_redirect;
738
739 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
740 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
741 goto reject_redirect;
742 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
743 goto reject_redirect;
744 } else {
745 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
746 goto reject_redirect;
747 }
748
749 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
750 if (!IS_ERR(n)) {
751 if (!(n->nud_state & NUD_VALID)) {
752 neigh_event_send(n, NULL);
753 } else {
754 if (fib_lookup(net, fl4, &res, 0) == 0) {
755 struct fib_nh *nh = &FIB_RES_NH(res);
756
757 update_or_create_fnhe(nh, fl4->daddr, new_gw,
758 0, 0);
759 }
760 if (kill_route)
761 rt->dst.obsolete = DST_OBSOLETE_KILL;
762 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
763 }
764 neigh_release(n);
765 }
766 return;
767
768 reject_redirect:
769 #ifdef CONFIG_IP_ROUTE_VERBOSE
770 if (IN_DEV_LOG_MARTIANS(in_dev)) {
771 const struct iphdr *iph = (const struct iphdr *) skb->data;
772 __be32 daddr = iph->daddr;
773 __be32 saddr = iph->saddr;
774
775 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
776 " Advised path = %pI4 -> %pI4\n",
777 &old_gw, dev->name, &new_gw,
778 &saddr, &daddr);
779 }
780 #endif
781 ;
782 }
783
784 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
785 {
786 struct rtable *rt;
787 struct flowi4 fl4;
788 const struct iphdr *iph = (const struct iphdr *) skb->data;
789 int oif = skb->dev->ifindex;
790 u8 tos = RT_TOS(iph->tos);
791 u8 prot = iph->protocol;
792 u32 mark = skb->mark;
793
794 rt = (struct rtable *) dst;
795
796 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
797 __ip_do_redirect(rt, skb, &fl4, true);
798 }
799
800 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
801 {
802 struct rtable *rt = (struct rtable *)dst;
803 struct dst_entry *ret = dst;
804
805 if (rt) {
806 if (dst->obsolete > 0) {
807 ip_rt_put(rt);
808 ret = NULL;
809 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
810 rt->dst.expires) {
811 ip_rt_put(rt);
812 ret = NULL;
813 }
814 }
815 return ret;
816 }
817
818 /*
819 * Algorithm:
820 * 1. The first ip_rt_redirect_number redirects are sent
821 * with exponential backoff, then we stop sending them at all,
822 * assuming that the host ignores our redirects.
823 * 2. If we did not see packets requiring redirects
824 * during ip_rt_redirect_silence, we assume that the host
825 * forgot redirected route and start to send redirects again.
826 *
827 * This algorithm is much cheaper and more intelligent than dumb load limiting
828 * in icmp.c.
829 *
830 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
831 * and "frag. need" (breaks PMTU discovery) in icmp.c.
832 */
833
834 void ip_rt_send_redirect(struct sk_buff *skb)
835 {
836 struct rtable *rt = skb_rtable(skb);
837 struct in_device *in_dev;
838 struct inet_peer *peer;
839 struct net *net;
840 int log_martians;
841 int vif;
842
843 rcu_read_lock();
844 in_dev = __in_dev_get_rcu(rt->dst.dev);
845 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
846 rcu_read_unlock();
847 return;
848 }
849 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
850 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
851 rcu_read_unlock();
852
853 net = dev_net(rt->dst.dev);
854 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
855 if (!peer) {
856 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
857 rt_nexthop(rt, ip_hdr(skb)->daddr));
858 return;
859 }
860
861 /* No redirected packets during ip_rt_redirect_silence;
862 * reset the algorithm.
863 */
864 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
865 peer->rate_tokens = 0;
866
867 /* Too many ignored redirects; do not send anything
868 * set dst.rate_last to the last seen redirected packet.
869 */
870 if (peer->rate_tokens >= ip_rt_redirect_number) {
871 peer->rate_last = jiffies;
872 goto out_put_peer;
873 }
874
875 /* Check for load limit; set rate_last to the latest sent
876 * redirect.
877 */
878 if (peer->rate_tokens == 0 ||
879 time_after(jiffies,
880 (peer->rate_last +
881 (ip_rt_redirect_load << peer->rate_tokens)))) {
882 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
883
884 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
885 peer->rate_last = jiffies;
886 ++peer->rate_tokens;
887 #ifdef CONFIG_IP_ROUTE_VERBOSE
888 if (log_martians &&
889 peer->rate_tokens == ip_rt_redirect_number)
890 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
891 &ip_hdr(skb)->saddr, inet_iif(skb),
892 &ip_hdr(skb)->daddr, &gw);
893 #endif
894 }
895 out_put_peer:
896 inet_putpeer(peer);
897 }
898
899 static int ip_error(struct sk_buff *skb)
900 {
901 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
902 struct rtable *rt = skb_rtable(skb);
903 struct inet_peer *peer;
904 unsigned long now;
905 struct net *net;
906 bool send;
907 int code;
908
909 /* IP on this device is disabled. */
910 if (!in_dev)
911 goto out;
912
913 net = dev_net(rt->dst.dev);
914 if (!IN_DEV_FORWARD(in_dev)) {
915 switch (rt->dst.error) {
916 case EHOSTUNREACH:
917 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
918 break;
919
920 case ENETUNREACH:
921 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
922 break;
923 }
924 goto out;
925 }
926
927 switch (rt->dst.error) {
928 case EINVAL:
929 default:
930 goto out;
931 case EHOSTUNREACH:
932 code = ICMP_HOST_UNREACH;
933 break;
934 case ENETUNREACH:
935 code = ICMP_NET_UNREACH;
936 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
937 break;
938 case EACCES:
939 code = ICMP_PKT_FILTERED;
940 break;
941 }
942
943 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
944 l3mdev_master_ifindex(skb->dev), 1);
945
946 send = true;
947 if (peer) {
948 now = jiffies;
949 peer->rate_tokens += now - peer->rate_last;
950 if (peer->rate_tokens > ip_rt_error_burst)
951 peer->rate_tokens = ip_rt_error_burst;
952 peer->rate_last = now;
953 if (peer->rate_tokens >= ip_rt_error_cost)
954 peer->rate_tokens -= ip_rt_error_cost;
955 else
956 send = false;
957 inet_putpeer(peer);
958 }
959 if (send)
960 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
961
962 out: kfree_skb(skb);
963 return 0;
964 }
965
966 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
967 {
968 struct dst_entry *dst = &rt->dst;
969 struct fib_result res;
970
971 if (dst_metric_locked(dst, RTAX_MTU))
972 return;
973
974 if (ipv4_mtu(dst) < mtu)
975 return;
976
977 if (mtu < ip_rt_min_pmtu)
978 mtu = ip_rt_min_pmtu;
979
980 if (rt->rt_pmtu == mtu &&
981 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
982 return;
983
984 rcu_read_lock();
985 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
986 struct fib_nh *nh = &FIB_RES_NH(res);
987
988 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
989 jiffies + ip_rt_mtu_expires);
990 }
991 rcu_read_unlock();
992 }
993
994 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
995 struct sk_buff *skb, u32 mtu)
996 {
997 struct rtable *rt = (struct rtable *) dst;
998 struct flowi4 fl4;
999
1000 ip_rt_build_flow_key(&fl4, sk, skb);
1001 __ip_rt_update_pmtu(rt, &fl4, mtu);
1002 }
1003
1004 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1005 int oif, u32 mark, u8 protocol, int flow_flags)
1006 {
1007 const struct iphdr *iph = (const struct iphdr *) skb->data;
1008 struct flowi4 fl4;
1009 struct rtable *rt;
1010
1011 if (!mark)
1012 mark = IP4_REPLY_MARK(net, skb->mark);
1013
1014 __build_flow_key(&fl4, NULL, iph, oif,
1015 RT_TOS(iph->tos), protocol, mark, flow_flags);
1016 rt = __ip_route_output_key(net, &fl4);
1017 if (!IS_ERR(rt)) {
1018 __ip_rt_update_pmtu(rt, &fl4, mtu);
1019 ip_rt_put(rt);
1020 }
1021 }
1022 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1023
1024 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1025 {
1026 const struct iphdr *iph = (const struct iphdr *) skb->data;
1027 struct flowi4 fl4;
1028 struct rtable *rt;
1029
1030 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1031
1032 if (!fl4.flowi4_mark)
1033 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1034
1035 rt = __ip_route_output_key(sock_net(sk), &fl4);
1036 if (!IS_ERR(rt)) {
1037 __ip_rt_update_pmtu(rt, &fl4, mtu);
1038 ip_rt_put(rt);
1039 }
1040 }
1041
1042 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1043 {
1044 const struct iphdr *iph = (const struct iphdr *) skb->data;
1045 struct flowi4 fl4;
1046 struct rtable *rt;
1047 struct dst_entry *odst = NULL;
1048 bool new = false;
1049
1050 bh_lock_sock(sk);
1051
1052 if (!ip_sk_accept_pmtu(sk))
1053 goto out;
1054
1055 odst = sk_dst_get(sk);
1056
1057 if (sock_owned_by_user(sk) || !odst) {
1058 __ipv4_sk_update_pmtu(skb, sk, mtu);
1059 goto out;
1060 }
1061
1062 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1063
1064 rt = (struct rtable *)odst;
1065 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1066 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1067 if (IS_ERR(rt))
1068 goto out;
1069
1070 new = true;
1071 }
1072
1073 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1074
1075 if (!dst_check(&rt->dst, 0)) {
1076 if (new)
1077 dst_release(&rt->dst);
1078
1079 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1080 if (IS_ERR(rt))
1081 goto out;
1082
1083 new = true;
1084 }
1085
1086 if (new)
1087 sk_dst_set(sk, &rt->dst);
1088
1089 out:
1090 bh_unlock_sock(sk);
1091 dst_release(odst);
1092 }
1093 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1094
1095 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1096 int oif, u32 mark, u8 protocol, int flow_flags)
1097 {
1098 const struct iphdr *iph = (const struct iphdr *) skb->data;
1099 struct flowi4 fl4;
1100 struct rtable *rt;
1101
1102 __build_flow_key(&fl4, NULL, iph, oif,
1103 RT_TOS(iph->tos), protocol, mark, flow_flags);
1104 rt = __ip_route_output_key(net, &fl4);
1105 if (!IS_ERR(rt)) {
1106 __ip_do_redirect(rt, skb, &fl4, false);
1107 ip_rt_put(rt);
1108 }
1109 }
1110 EXPORT_SYMBOL_GPL(ipv4_redirect);
1111
1112 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1113 {
1114 const struct iphdr *iph = (const struct iphdr *) skb->data;
1115 struct flowi4 fl4;
1116 struct rtable *rt;
1117
1118 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1119 rt = __ip_route_output_key(sock_net(sk), &fl4);
1120 if (!IS_ERR(rt)) {
1121 __ip_do_redirect(rt, skb, &fl4, false);
1122 ip_rt_put(rt);
1123 }
1124 }
1125 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1126
1127 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1128 {
1129 struct rtable *rt = (struct rtable *) dst;
1130
1131 /* All IPV4 dsts are created with ->obsolete set to the value
1132 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1133 * into this function always.
1134 *
1135 * When a PMTU/redirect information update invalidates a route,
1136 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1137 * DST_OBSOLETE_DEAD by dst_free().
1138 */
1139 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1140 return NULL;
1141 return dst;
1142 }
1143
1144 static void ipv4_link_failure(struct sk_buff *skb)
1145 {
1146 struct rtable *rt;
1147
1148 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1149
1150 rt = skb_rtable(skb);
1151 if (rt)
1152 dst_set_expires(&rt->dst, 0);
1153 }
1154
1155 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1156 {
1157 pr_debug("%s: %pI4 -> %pI4, %s\n",
1158 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1159 skb->dev ? skb->dev->name : "?");
1160 kfree_skb(skb);
1161 WARN_ON(1);
1162 return 0;
1163 }
1164
1165 /*
1166 We do not cache source address of outgoing interface,
1167 because it is used only by IP RR, TS and SRR options,
1168 so that it out of fast path.
1169
1170 BTW remember: "addr" is allowed to be not aligned
1171 in IP options!
1172 */
1173
1174 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1175 {
1176 __be32 src;
1177
1178 if (rt_is_output_route(rt))
1179 src = ip_hdr(skb)->saddr;
1180 else {
1181 struct fib_result res;
1182 struct flowi4 fl4;
1183 struct iphdr *iph;
1184
1185 iph = ip_hdr(skb);
1186
1187 memset(&fl4, 0, sizeof(fl4));
1188 fl4.daddr = iph->daddr;
1189 fl4.saddr = iph->saddr;
1190 fl4.flowi4_tos = RT_TOS(iph->tos);
1191 fl4.flowi4_oif = rt->dst.dev->ifindex;
1192 fl4.flowi4_iif = skb->dev->ifindex;
1193 fl4.flowi4_mark = skb->mark;
1194
1195 rcu_read_lock();
1196 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1197 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1198 else
1199 src = inet_select_addr(rt->dst.dev,
1200 rt_nexthop(rt, iph->daddr),
1201 RT_SCOPE_UNIVERSE);
1202 rcu_read_unlock();
1203 }
1204 memcpy(addr, &src, 4);
1205 }
1206
1207 #ifdef CONFIG_IP_ROUTE_CLASSID
1208 static void set_class_tag(struct rtable *rt, u32 tag)
1209 {
1210 if (!(rt->dst.tclassid & 0xFFFF))
1211 rt->dst.tclassid |= tag & 0xFFFF;
1212 if (!(rt->dst.tclassid & 0xFFFF0000))
1213 rt->dst.tclassid |= tag & 0xFFFF0000;
1214 }
1215 #endif
1216
1217 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1218 {
1219 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1220
1221 if (advmss == 0) {
1222 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1223 ip_rt_min_advmss);
1224 if (advmss > 65535 - 40)
1225 advmss = 65535 - 40;
1226 }
1227 return advmss;
1228 }
1229
1230 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1231 {
1232 const struct rtable *rt = (const struct rtable *) dst;
1233 unsigned int mtu = rt->rt_pmtu;
1234
1235 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1236 mtu = dst_metric_raw(dst, RTAX_MTU);
1237
1238 if (mtu)
1239 return mtu;
1240
1241 mtu = dst->dev->mtu;
1242
1243 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1244 if (rt->rt_uses_gateway && mtu > 576)
1245 mtu = 576;
1246 }
1247
1248 return min_t(unsigned int, mtu, IP_MAX_MTU);
1249 }
1250
1251 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1252 {
1253 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1254 struct fib_nh_exception *fnhe;
1255 u32 hval;
1256
1257 if (!hash)
1258 return NULL;
1259
1260 hval = fnhe_hashfun(daddr);
1261
1262 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1263 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1264 if (fnhe->fnhe_daddr == daddr)
1265 return fnhe;
1266 }
1267 return NULL;
1268 }
1269
1270 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1271 __be32 daddr)
1272 {
1273 bool ret = false;
1274
1275 spin_lock_bh(&fnhe_lock);
1276
1277 if (daddr == fnhe->fnhe_daddr) {
1278 struct rtable __rcu **porig;
1279 struct rtable *orig;
1280 int genid = fnhe_genid(dev_net(rt->dst.dev));
1281
1282 if (rt_is_input_route(rt))
1283 porig = &fnhe->fnhe_rth_input;
1284 else
1285 porig = &fnhe->fnhe_rth_output;
1286 orig = rcu_dereference(*porig);
1287
1288 if (fnhe->fnhe_genid != genid) {
1289 fnhe->fnhe_genid = genid;
1290 fnhe->fnhe_gw = 0;
1291 fnhe->fnhe_pmtu = 0;
1292 fnhe->fnhe_expires = 0;
1293 fnhe_flush_routes(fnhe);
1294 orig = NULL;
1295 }
1296 fill_route_from_fnhe(rt, fnhe);
1297 if (!rt->rt_gateway)
1298 rt->rt_gateway = daddr;
1299
1300 if (!(rt->dst.flags & DST_NOCACHE)) {
1301 rcu_assign_pointer(*porig, rt);
1302 if (orig)
1303 rt_free(orig);
1304 ret = true;
1305 }
1306
1307 fnhe->fnhe_stamp = jiffies;
1308 }
1309 spin_unlock_bh(&fnhe_lock);
1310
1311 return ret;
1312 }
1313
1314 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1315 {
1316 struct rtable *orig, *prev, **p;
1317 bool ret = true;
1318
1319 if (rt_is_input_route(rt)) {
1320 p = (struct rtable **)&nh->nh_rth_input;
1321 } else {
1322 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1323 }
1324 orig = *p;
1325
1326 prev = cmpxchg(p, orig, rt);
1327 if (prev == orig) {
1328 if (orig)
1329 rt_free(orig);
1330 } else
1331 ret = false;
1332
1333 return ret;
1334 }
1335
1336 struct uncached_list {
1337 spinlock_t lock;
1338 struct list_head head;
1339 };
1340
1341 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1342
1343 static void rt_add_uncached_list(struct rtable *rt)
1344 {
1345 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1346
1347 rt->rt_uncached_list = ul;
1348
1349 spin_lock_bh(&ul->lock);
1350 list_add_tail(&rt->rt_uncached, &ul->head);
1351 spin_unlock_bh(&ul->lock);
1352 }
1353
1354 static void ipv4_dst_destroy(struct dst_entry *dst)
1355 {
1356 struct rtable *rt = (struct rtable *) dst;
1357
1358 if (!list_empty(&rt->rt_uncached)) {
1359 struct uncached_list *ul = rt->rt_uncached_list;
1360
1361 spin_lock_bh(&ul->lock);
1362 list_del(&rt->rt_uncached);
1363 spin_unlock_bh(&ul->lock);
1364 }
1365 }
1366
1367 void rt_flush_dev(struct net_device *dev)
1368 {
1369 struct net *net = dev_net(dev);
1370 struct rtable *rt;
1371 int cpu;
1372
1373 for_each_possible_cpu(cpu) {
1374 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1375
1376 spin_lock_bh(&ul->lock);
1377 list_for_each_entry(rt, &ul->head, rt_uncached) {
1378 if (rt->dst.dev != dev)
1379 continue;
1380 rt->dst.dev = net->loopback_dev;
1381 dev_hold(rt->dst.dev);
1382 dev_put(dev);
1383 }
1384 spin_unlock_bh(&ul->lock);
1385 }
1386 }
1387
1388 static bool rt_cache_valid(const struct rtable *rt)
1389 {
1390 return rt &&
1391 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1392 !rt_is_expired(rt);
1393 }
1394
1395 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1396 const struct fib_result *res,
1397 struct fib_nh_exception *fnhe,
1398 struct fib_info *fi, u16 type, u32 itag)
1399 {
1400 bool cached = false;
1401
1402 if (fi) {
1403 struct fib_nh *nh = &FIB_RES_NH(*res);
1404
1405 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1406 rt->rt_gateway = nh->nh_gw;
1407 rt->rt_uses_gateway = 1;
1408 }
1409 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1410 #ifdef CONFIG_IP_ROUTE_CLASSID
1411 rt->dst.tclassid = nh->nh_tclassid;
1412 #endif
1413 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
1414 if (unlikely(fnhe))
1415 cached = rt_bind_exception(rt, fnhe, daddr);
1416 else if (!(rt->dst.flags & DST_NOCACHE))
1417 cached = rt_cache_route(nh, rt);
1418 if (unlikely(!cached)) {
1419 /* Routes we intend to cache in nexthop exception or
1420 * FIB nexthop have the DST_NOCACHE bit clear.
1421 * However, if we are unsuccessful at storing this
1422 * route into the cache we really need to set it.
1423 */
1424 rt->dst.flags |= DST_NOCACHE;
1425 if (!rt->rt_gateway)
1426 rt->rt_gateway = daddr;
1427 rt_add_uncached_list(rt);
1428 }
1429 } else
1430 rt_add_uncached_list(rt);
1431
1432 #ifdef CONFIG_IP_ROUTE_CLASSID
1433 #ifdef CONFIG_IP_MULTIPLE_TABLES
1434 set_class_tag(rt, res->tclassid);
1435 #endif
1436 set_class_tag(rt, itag);
1437 #endif
1438 }
1439
1440 static struct rtable *rt_dst_alloc(struct net_device *dev,
1441 unsigned int flags, u16 type,
1442 bool nopolicy, bool noxfrm, bool will_cache)
1443 {
1444 struct rtable *rt;
1445
1446 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1447 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1448 (nopolicy ? DST_NOPOLICY : 0) |
1449 (noxfrm ? DST_NOXFRM : 0));
1450
1451 if (rt) {
1452 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1453 rt->rt_flags = flags;
1454 rt->rt_type = type;
1455 rt->rt_is_input = 0;
1456 rt->rt_iif = 0;
1457 rt->rt_pmtu = 0;
1458 rt->rt_gateway = 0;
1459 rt->rt_uses_gateway = 0;
1460 rt->rt_table_id = 0;
1461 INIT_LIST_HEAD(&rt->rt_uncached);
1462
1463 rt->dst.output = ip_output;
1464 if (flags & RTCF_LOCAL)
1465 rt->dst.input = ip_local_deliver;
1466 }
1467
1468 return rt;
1469 }
1470
1471 /* called in rcu_read_lock() section */
1472 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1473 u8 tos, struct net_device *dev, int our)
1474 {
1475 struct rtable *rth;
1476 struct in_device *in_dev = __in_dev_get_rcu(dev);
1477 unsigned int flags = RTCF_MULTICAST;
1478 u32 itag = 0;
1479 int err;
1480
1481 /* Primary sanity checks. */
1482
1483 if (!in_dev)
1484 return -EINVAL;
1485
1486 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1487 skb->protocol != htons(ETH_P_IP))
1488 goto e_inval;
1489
1490 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1491 goto e_inval;
1492
1493 if (ipv4_is_zeronet(saddr)) {
1494 if (!ipv4_is_local_multicast(daddr))
1495 goto e_inval;
1496 } else {
1497 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1498 in_dev, &itag);
1499 if (err < 0)
1500 goto e_err;
1501 }
1502 if (our)
1503 flags |= RTCF_LOCAL;
1504
1505 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1506 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1507 if (!rth)
1508 goto e_nobufs;
1509
1510 #ifdef CONFIG_IP_ROUTE_CLASSID
1511 rth->dst.tclassid = itag;
1512 #endif
1513 rth->dst.output = ip_rt_bug;
1514 rth->rt_is_input= 1;
1515
1516 #ifdef CONFIG_IP_MROUTE
1517 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1518 rth->dst.input = ip_mr_input;
1519 #endif
1520 RT_CACHE_STAT_INC(in_slow_mc);
1521
1522 skb_dst_set(skb, &rth->dst);
1523 return 0;
1524
1525 e_nobufs:
1526 return -ENOBUFS;
1527 e_inval:
1528 return -EINVAL;
1529 e_err:
1530 return err;
1531 }
1532
1533
1534 static void ip_handle_martian_source(struct net_device *dev,
1535 struct in_device *in_dev,
1536 struct sk_buff *skb,
1537 __be32 daddr,
1538 __be32 saddr)
1539 {
1540 RT_CACHE_STAT_INC(in_martian_src);
1541 #ifdef CONFIG_IP_ROUTE_VERBOSE
1542 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1543 /*
1544 * RFC1812 recommendation, if source is martian,
1545 * the only hint is MAC header.
1546 */
1547 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1548 &daddr, &saddr, dev->name);
1549 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1550 print_hex_dump(KERN_WARNING, "ll header: ",
1551 DUMP_PREFIX_OFFSET, 16, 1,
1552 skb_mac_header(skb),
1553 dev->hard_header_len, true);
1554 }
1555 }
1556 #endif
1557 }
1558
1559 /* called in rcu_read_lock() section */
1560 static int __mkroute_input(struct sk_buff *skb,
1561 const struct fib_result *res,
1562 struct in_device *in_dev,
1563 __be32 daddr, __be32 saddr, u32 tos)
1564 {
1565 struct fib_nh_exception *fnhe;
1566 struct rtable *rth;
1567 int err;
1568 struct in_device *out_dev;
1569 bool do_cache;
1570 u32 itag = 0;
1571
1572 /* get a working reference to the output device */
1573 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1574 if (!out_dev) {
1575 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1576 return -EINVAL;
1577 }
1578
1579 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1580 in_dev->dev, in_dev, &itag);
1581 if (err < 0) {
1582 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1583 saddr);
1584
1585 goto cleanup;
1586 }
1587
1588 do_cache = res->fi && !itag;
1589 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1590 skb->protocol == htons(ETH_P_IP) &&
1591 (IN_DEV_SHARED_MEDIA(out_dev) ||
1592 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1593 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1594
1595 if (skb->protocol != htons(ETH_P_IP)) {
1596 /* Not IP (i.e. ARP). Do not create route, if it is
1597 * invalid for proxy arp. DNAT routes are always valid.
1598 *
1599 * Proxy arp feature have been extended to allow, ARP
1600 * replies back to the same interface, to support
1601 * Private VLAN switch technologies. See arp.c.
1602 */
1603 if (out_dev == in_dev &&
1604 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1605 err = -EINVAL;
1606 goto cleanup;
1607 }
1608 }
1609
1610 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1611 if (do_cache) {
1612 if (fnhe)
1613 rth = rcu_dereference(fnhe->fnhe_rth_input);
1614 else
1615 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1616
1617 if (rt_cache_valid(rth)) {
1618 skb_dst_set_noref(skb, &rth->dst);
1619 goto out;
1620 }
1621 }
1622
1623 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1624 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1625 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1626 if (!rth) {
1627 err = -ENOBUFS;
1628 goto cleanup;
1629 }
1630
1631 rth->rt_is_input = 1;
1632 if (res->table)
1633 rth->rt_table_id = res->table->tb_id;
1634 RT_CACHE_STAT_INC(in_slow_tot);
1635
1636 rth->dst.input = ip_forward;
1637
1638 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1639 if (lwtunnel_output_redirect(rth->dst.lwtstate)) {
1640 rth->dst.lwtstate->orig_output = rth->dst.output;
1641 rth->dst.output = lwtunnel_output;
1642 }
1643 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
1644 rth->dst.lwtstate->orig_input = rth->dst.input;
1645 rth->dst.input = lwtunnel_input;
1646 }
1647 skb_dst_set(skb, &rth->dst);
1648 out:
1649 err = 0;
1650 cleanup:
1651 return err;
1652 }
1653
1654 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1655
1656 /* To make ICMP packets follow the right flow, the multipath hash is
1657 * calculated from the inner IP addresses in reverse order.
1658 */
1659 static int ip_multipath_icmp_hash(struct sk_buff *skb)
1660 {
1661 const struct iphdr *outer_iph = ip_hdr(skb);
1662 struct icmphdr _icmph;
1663 const struct icmphdr *icmph;
1664 struct iphdr _inner_iph;
1665 const struct iphdr *inner_iph;
1666
1667 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1668 goto standard_hash;
1669
1670 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1671 &_icmph);
1672 if (!icmph)
1673 goto standard_hash;
1674
1675 if (icmph->type != ICMP_DEST_UNREACH &&
1676 icmph->type != ICMP_REDIRECT &&
1677 icmph->type != ICMP_TIME_EXCEEDED &&
1678 icmph->type != ICMP_PARAMETERPROB) {
1679 goto standard_hash;
1680 }
1681
1682 inner_iph = skb_header_pointer(skb,
1683 outer_iph->ihl * 4 + sizeof(_icmph),
1684 sizeof(_inner_iph), &_inner_iph);
1685 if (!inner_iph)
1686 goto standard_hash;
1687
1688 return fib_multipath_hash(inner_iph->daddr, inner_iph->saddr);
1689
1690 standard_hash:
1691 return fib_multipath_hash(outer_iph->saddr, outer_iph->daddr);
1692 }
1693
1694 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
1695
1696 static int ip_mkroute_input(struct sk_buff *skb,
1697 struct fib_result *res,
1698 const struct flowi4 *fl4,
1699 struct in_device *in_dev,
1700 __be32 daddr, __be32 saddr, u32 tos)
1701 {
1702 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1703 if (res->fi && res->fi->fib_nhs > 1) {
1704 int h;
1705
1706 if (unlikely(ip_hdr(skb)->protocol == IPPROTO_ICMP))
1707 h = ip_multipath_icmp_hash(skb);
1708 else
1709 h = fib_multipath_hash(saddr, daddr);
1710 fib_select_multipath(res, h);
1711 }
1712 #endif
1713
1714 /* create a routing cache entry */
1715 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1716 }
1717
1718 /*
1719 * NOTE. We drop all the packets that has local source
1720 * addresses, because every properly looped back packet
1721 * must have correct destination already attached by output routine.
1722 *
1723 * Such approach solves two big problems:
1724 * 1. Not simplex devices are handled properly.
1725 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1726 * called with rcu_read_lock()
1727 */
1728
1729 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1730 u8 tos, struct net_device *dev)
1731 {
1732 struct fib_result res;
1733 struct in_device *in_dev = __in_dev_get_rcu(dev);
1734 struct ip_tunnel_info *tun_info;
1735 struct flowi4 fl4;
1736 unsigned int flags = 0;
1737 u32 itag = 0;
1738 struct rtable *rth;
1739 int err = -EINVAL;
1740 struct net *net = dev_net(dev);
1741 bool do_cache;
1742
1743 /* IP on this device is disabled. */
1744
1745 if (!in_dev)
1746 goto out;
1747
1748 /* Check for the most weird martians, which can be not detected
1749 by fib_lookup.
1750 */
1751
1752 tun_info = skb_tunnel_info(skb);
1753 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
1754 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
1755 else
1756 fl4.flowi4_tun_key.tun_id = 0;
1757 skb_dst_drop(skb);
1758
1759 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1760 goto martian_source;
1761
1762 res.fi = NULL;
1763 res.table = NULL;
1764 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1765 goto brd_input;
1766
1767 /* Accept zero addresses only to limited broadcast;
1768 * I even do not know to fix it or not. Waiting for complains :-)
1769 */
1770 if (ipv4_is_zeronet(saddr))
1771 goto martian_source;
1772
1773 if (ipv4_is_zeronet(daddr))
1774 goto martian_destination;
1775
1776 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1777 * and call it once if daddr or/and saddr are loopback addresses
1778 */
1779 if (ipv4_is_loopback(daddr)) {
1780 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1781 goto martian_destination;
1782 } else if (ipv4_is_loopback(saddr)) {
1783 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1784 goto martian_source;
1785 }
1786
1787 /*
1788 * Now we are ready to route packet.
1789 */
1790 fl4.flowi4_oif = 0;
1791 fl4.flowi4_iif = l3mdev_fib_oif_rcu(dev);
1792 fl4.flowi4_mark = skb->mark;
1793 fl4.flowi4_tos = tos;
1794 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1795 fl4.flowi4_flags = 0;
1796 fl4.daddr = daddr;
1797 fl4.saddr = saddr;
1798 err = fib_lookup(net, &fl4, &res, 0);
1799 if (err != 0) {
1800 if (!IN_DEV_FORWARD(in_dev))
1801 err = -EHOSTUNREACH;
1802 goto no_route;
1803 }
1804
1805 if (res.type == RTN_BROADCAST)
1806 goto brd_input;
1807
1808 if (res.type == RTN_LOCAL) {
1809 err = fib_validate_source(skb, saddr, daddr, tos,
1810 0, dev, in_dev, &itag);
1811 if (err < 0)
1812 goto martian_source;
1813 goto local_input;
1814 }
1815
1816 if (!IN_DEV_FORWARD(in_dev)) {
1817 err = -EHOSTUNREACH;
1818 goto no_route;
1819 }
1820 if (res.type != RTN_UNICAST)
1821 goto martian_destination;
1822
1823 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1824 out: return err;
1825
1826 brd_input:
1827 if (skb->protocol != htons(ETH_P_IP))
1828 goto e_inval;
1829
1830 if (!ipv4_is_zeronet(saddr)) {
1831 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1832 in_dev, &itag);
1833 if (err < 0)
1834 goto martian_source;
1835 }
1836 flags |= RTCF_BROADCAST;
1837 res.type = RTN_BROADCAST;
1838 RT_CACHE_STAT_INC(in_brd);
1839
1840 local_input:
1841 do_cache = false;
1842 if (res.fi) {
1843 if (!itag) {
1844 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1845 if (rt_cache_valid(rth)) {
1846 skb_dst_set_noref(skb, &rth->dst);
1847 err = 0;
1848 goto out;
1849 }
1850 do_cache = true;
1851 }
1852 }
1853
1854 rth = rt_dst_alloc(net->loopback_dev, flags | RTCF_LOCAL, res.type,
1855 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1856 if (!rth)
1857 goto e_nobufs;
1858
1859 rth->dst.output= ip_rt_bug;
1860 #ifdef CONFIG_IP_ROUTE_CLASSID
1861 rth->dst.tclassid = itag;
1862 #endif
1863 rth->rt_is_input = 1;
1864 if (res.table)
1865 rth->rt_table_id = res.table->tb_id;
1866
1867 RT_CACHE_STAT_INC(in_slow_tot);
1868 if (res.type == RTN_UNREACHABLE) {
1869 rth->dst.input= ip_error;
1870 rth->dst.error= -err;
1871 rth->rt_flags &= ~RTCF_LOCAL;
1872 }
1873 if (do_cache) {
1874 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1875 rth->dst.flags |= DST_NOCACHE;
1876 rt_add_uncached_list(rth);
1877 }
1878 }
1879 skb_dst_set(skb, &rth->dst);
1880 err = 0;
1881 goto out;
1882
1883 no_route:
1884 RT_CACHE_STAT_INC(in_no_route);
1885 res.type = RTN_UNREACHABLE;
1886 res.fi = NULL;
1887 res.table = NULL;
1888 goto local_input;
1889
1890 /*
1891 * Do not cache martian addresses: they should be logged (RFC1812)
1892 */
1893 martian_destination:
1894 RT_CACHE_STAT_INC(in_martian_dst);
1895 #ifdef CONFIG_IP_ROUTE_VERBOSE
1896 if (IN_DEV_LOG_MARTIANS(in_dev))
1897 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1898 &daddr, &saddr, dev->name);
1899 #endif
1900
1901 e_inval:
1902 err = -EINVAL;
1903 goto out;
1904
1905 e_nobufs:
1906 err = -ENOBUFS;
1907 goto out;
1908
1909 martian_source:
1910 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1911 goto out;
1912 }
1913
1914 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1915 u8 tos, struct net_device *dev)
1916 {
1917 int res;
1918
1919 rcu_read_lock();
1920
1921 /* Multicast recognition logic is moved from route cache to here.
1922 The problem was that too many Ethernet cards have broken/missing
1923 hardware multicast filters :-( As result the host on multicasting
1924 network acquires a lot of useless route cache entries, sort of
1925 SDR messages from all the world. Now we try to get rid of them.
1926 Really, provided software IP multicast filter is organized
1927 reasonably (at least, hashed), it does not result in a slowdown
1928 comparing with route cache reject entries.
1929 Note, that multicast routers are not affected, because
1930 route cache entry is created eventually.
1931 */
1932 if (ipv4_is_multicast(daddr)) {
1933 struct in_device *in_dev = __in_dev_get_rcu(dev);
1934
1935 if (in_dev) {
1936 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1937 ip_hdr(skb)->protocol);
1938 if (our
1939 #ifdef CONFIG_IP_MROUTE
1940 ||
1941 (!ipv4_is_local_multicast(daddr) &&
1942 IN_DEV_MFORWARD(in_dev))
1943 #endif
1944 ) {
1945 int res = ip_route_input_mc(skb, daddr, saddr,
1946 tos, dev, our);
1947 rcu_read_unlock();
1948 return res;
1949 }
1950 }
1951 rcu_read_unlock();
1952 return -EINVAL;
1953 }
1954 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1955 rcu_read_unlock();
1956 return res;
1957 }
1958 EXPORT_SYMBOL(ip_route_input_noref);
1959
1960 /* called with rcu_read_lock() */
1961 static struct rtable *__mkroute_output(const struct fib_result *res,
1962 const struct flowi4 *fl4, int orig_oif,
1963 struct net_device *dev_out,
1964 unsigned int flags)
1965 {
1966 struct fib_info *fi = res->fi;
1967 struct fib_nh_exception *fnhe;
1968 struct in_device *in_dev;
1969 u16 type = res->type;
1970 struct rtable *rth;
1971 bool do_cache;
1972
1973 in_dev = __in_dev_get_rcu(dev_out);
1974 if (!in_dev)
1975 return ERR_PTR(-EINVAL);
1976
1977 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1978 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1979 return ERR_PTR(-EINVAL);
1980
1981 if (ipv4_is_lbcast(fl4->daddr))
1982 type = RTN_BROADCAST;
1983 else if (ipv4_is_multicast(fl4->daddr))
1984 type = RTN_MULTICAST;
1985 else if (ipv4_is_zeronet(fl4->daddr))
1986 return ERR_PTR(-EINVAL);
1987
1988 if (dev_out->flags & IFF_LOOPBACK)
1989 flags |= RTCF_LOCAL;
1990
1991 do_cache = true;
1992 if (type == RTN_BROADCAST) {
1993 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1994 fi = NULL;
1995 } else if (type == RTN_MULTICAST) {
1996 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1997 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1998 fl4->flowi4_proto))
1999 flags &= ~RTCF_LOCAL;
2000 else
2001 do_cache = false;
2002 /* If multicast route do not exist use
2003 * default one, but do not gateway in this case.
2004 * Yes, it is hack.
2005 */
2006 if (fi && res->prefixlen < 4)
2007 fi = NULL;
2008 }
2009
2010 fnhe = NULL;
2011 do_cache &= fi != NULL;
2012 if (do_cache) {
2013 struct rtable __rcu **prth;
2014 struct fib_nh *nh = &FIB_RES_NH(*res);
2015
2016 fnhe = find_exception(nh, fl4->daddr);
2017 if (fnhe)
2018 prth = &fnhe->fnhe_rth_output;
2019 else {
2020 if (unlikely(fl4->flowi4_flags &
2021 FLOWI_FLAG_KNOWN_NH &&
2022 !(nh->nh_gw &&
2023 nh->nh_scope == RT_SCOPE_LINK))) {
2024 do_cache = false;
2025 goto add;
2026 }
2027 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
2028 }
2029 rth = rcu_dereference(*prth);
2030 if (rt_cache_valid(rth)) {
2031 dst_hold(&rth->dst);
2032 return rth;
2033 }
2034 }
2035
2036 add:
2037 rth = rt_dst_alloc(dev_out, flags, type,
2038 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2039 IN_DEV_CONF_GET(in_dev, NOXFRM),
2040 do_cache);
2041 if (!rth)
2042 return ERR_PTR(-ENOBUFS);
2043
2044 rth->rt_iif = orig_oif ? : 0;
2045 if (res->table)
2046 rth->rt_table_id = res->table->tb_id;
2047
2048 RT_CACHE_STAT_INC(out_slow_tot);
2049
2050 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2051 if (flags & RTCF_LOCAL &&
2052 !(dev_out->flags & IFF_LOOPBACK)) {
2053 rth->dst.output = ip_mc_output;
2054 RT_CACHE_STAT_INC(out_slow_mc);
2055 }
2056 #ifdef CONFIG_IP_MROUTE
2057 if (type == RTN_MULTICAST) {
2058 if (IN_DEV_MFORWARD(in_dev) &&
2059 !ipv4_is_local_multicast(fl4->daddr)) {
2060 rth->dst.input = ip_mr_input;
2061 rth->dst.output = ip_mc_output;
2062 }
2063 }
2064 #endif
2065 }
2066
2067 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
2068 if (lwtunnel_output_redirect(rth->dst.lwtstate))
2069 rth->dst.output = lwtunnel_output;
2070
2071 return rth;
2072 }
2073
2074 /*
2075 * Major route resolver routine.
2076 */
2077
2078 struct rtable *__ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2079 int mp_hash)
2080 {
2081 struct net_device *dev_out = NULL;
2082 __u8 tos = RT_FL_TOS(fl4);
2083 unsigned int flags = 0;
2084 struct fib_result res;
2085 struct rtable *rth;
2086 int orig_oif;
2087 int err = -ENETUNREACH;
2088
2089 res.tclassid = 0;
2090 res.fi = NULL;
2091 res.table = NULL;
2092
2093 orig_oif = fl4->flowi4_oif;
2094
2095 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2096 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2097 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2098 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2099
2100 rcu_read_lock();
2101 if (fl4->saddr) {
2102 rth = ERR_PTR(-EINVAL);
2103 if (ipv4_is_multicast(fl4->saddr) ||
2104 ipv4_is_lbcast(fl4->saddr) ||
2105 ipv4_is_zeronet(fl4->saddr))
2106 goto out;
2107
2108 /* I removed check for oif == dev_out->oif here.
2109 It was wrong for two reasons:
2110 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2111 is assigned to multiple interfaces.
2112 2. Moreover, we are allowed to send packets with saddr
2113 of another iface. --ANK
2114 */
2115
2116 if (fl4->flowi4_oif == 0 &&
2117 (ipv4_is_multicast(fl4->daddr) ||
2118 ipv4_is_lbcast(fl4->daddr))) {
2119 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2120 dev_out = __ip_dev_find(net, fl4->saddr, false);
2121 if (!dev_out)
2122 goto out;
2123
2124 /* Special hack: user can direct multicasts
2125 and limited broadcast via necessary interface
2126 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2127 This hack is not just for fun, it allows
2128 vic,vat and friends to work.
2129 They bind socket to loopback, set ttl to zero
2130 and expect that it will work.
2131 From the viewpoint of routing cache they are broken,
2132 because we are not allowed to build multicast path
2133 with loopback source addr (look, routing cache
2134 cannot know, that ttl is zero, so that packet
2135 will not leave this host and route is valid).
2136 Luckily, this hack is good workaround.
2137 */
2138
2139 fl4->flowi4_oif = dev_out->ifindex;
2140 goto make_route;
2141 }
2142
2143 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2144 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2145 if (!__ip_dev_find(net, fl4->saddr, false))
2146 goto out;
2147 }
2148 }
2149
2150
2151 if (fl4->flowi4_oif) {
2152 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2153 rth = ERR_PTR(-ENODEV);
2154 if (!dev_out)
2155 goto out;
2156
2157 /* RACE: Check return value of inet_select_addr instead. */
2158 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2159 rth = ERR_PTR(-ENETUNREACH);
2160 goto out;
2161 }
2162 if (ipv4_is_local_multicast(fl4->daddr) ||
2163 ipv4_is_lbcast(fl4->daddr) ||
2164 fl4->flowi4_proto == IPPROTO_IGMP) {
2165 if (!fl4->saddr)
2166 fl4->saddr = inet_select_addr(dev_out, 0,
2167 RT_SCOPE_LINK);
2168 goto make_route;
2169 }
2170 if (!fl4->saddr) {
2171 if (ipv4_is_multicast(fl4->daddr))
2172 fl4->saddr = inet_select_addr(dev_out, 0,
2173 fl4->flowi4_scope);
2174 else if (!fl4->daddr)
2175 fl4->saddr = inet_select_addr(dev_out, 0,
2176 RT_SCOPE_HOST);
2177 }
2178
2179 rth = l3mdev_get_rtable(dev_out, fl4);
2180 if (rth)
2181 goto out;
2182 }
2183
2184 if (!fl4->daddr) {
2185 fl4->daddr = fl4->saddr;
2186 if (!fl4->daddr)
2187 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2188 dev_out = net->loopback_dev;
2189 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2190 res.type = RTN_LOCAL;
2191 flags |= RTCF_LOCAL;
2192 goto make_route;
2193 }
2194
2195 err = fib_lookup(net, fl4, &res, 0);
2196 if (err) {
2197 res.fi = NULL;
2198 res.table = NULL;
2199 if (fl4->flowi4_oif &&
2200 !netif_index_is_l3_master(net, fl4->flowi4_oif)) {
2201 /* Apparently, routing tables are wrong. Assume,
2202 that the destination is on link.
2203
2204 WHY? DW.
2205 Because we are allowed to send to iface
2206 even if it has NO routes and NO assigned
2207 addresses. When oif is specified, routing
2208 tables are looked up with only one purpose:
2209 to catch if destination is gatewayed, rather than
2210 direct. Moreover, if MSG_DONTROUTE is set,
2211 we send packet, ignoring both routing tables
2212 and ifaddr state. --ANK
2213
2214
2215 We could make it even if oif is unknown,
2216 likely IPv6, but we do not.
2217 */
2218
2219 if (fl4->saddr == 0)
2220 fl4->saddr = inet_select_addr(dev_out, 0,
2221 RT_SCOPE_LINK);
2222 res.type = RTN_UNICAST;
2223 goto make_route;
2224 }
2225 rth = ERR_PTR(err);
2226 goto out;
2227 }
2228
2229 if (res.type == RTN_LOCAL) {
2230 if (!fl4->saddr) {
2231 if (res.fi->fib_prefsrc)
2232 fl4->saddr = res.fi->fib_prefsrc;
2233 else
2234 fl4->saddr = fl4->daddr;
2235 }
2236 dev_out = net->loopback_dev;
2237 fl4->flowi4_oif = dev_out->ifindex;
2238 flags |= RTCF_LOCAL;
2239 goto make_route;
2240 }
2241
2242 fib_select_path(net, &res, fl4, mp_hash);
2243
2244 dev_out = FIB_RES_DEV(res);
2245 fl4->flowi4_oif = dev_out->ifindex;
2246
2247
2248 make_route:
2249 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2250
2251 out:
2252 rcu_read_unlock();
2253 return rth;
2254 }
2255 EXPORT_SYMBOL_GPL(__ip_route_output_key_hash);
2256
2257 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2258 {
2259 return NULL;
2260 }
2261
2262 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2263 {
2264 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2265
2266 return mtu ? : dst->dev->mtu;
2267 }
2268
2269 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2270 struct sk_buff *skb, u32 mtu)
2271 {
2272 }
2273
2274 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2275 struct sk_buff *skb)
2276 {
2277 }
2278
2279 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2280 unsigned long old)
2281 {
2282 return NULL;
2283 }
2284
2285 static struct dst_ops ipv4_dst_blackhole_ops = {
2286 .family = AF_INET,
2287 .check = ipv4_blackhole_dst_check,
2288 .mtu = ipv4_blackhole_mtu,
2289 .default_advmss = ipv4_default_advmss,
2290 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2291 .redirect = ipv4_rt_blackhole_redirect,
2292 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2293 .neigh_lookup = ipv4_neigh_lookup,
2294 };
2295
2296 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2297 {
2298 struct rtable *ort = (struct rtable *) dst_orig;
2299 struct rtable *rt;
2300
2301 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2302 if (rt) {
2303 struct dst_entry *new = &rt->dst;
2304
2305 new->__use = 1;
2306 new->input = dst_discard;
2307 new->output = dst_discard_out;
2308
2309 new->dev = ort->dst.dev;
2310 if (new->dev)
2311 dev_hold(new->dev);
2312
2313 rt->rt_is_input = ort->rt_is_input;
2314 rt->rt_iif = ort->rt_iif;
2315 rt->rt_pmtu = ort->rt_pmtu;
2316
2317 rt->rt_genid = rt_genid_ipv4(net);
2318 rt->rt_flags = ort->rt_flags;
2319 rt->rt_type = ort->rt_type;
2320 rt->rt_gateway = ort->rt_gateway;
2321 rt->rt_uses_gateway = ort->rt_uses_gateway;
2322
2323 INIT_LIST_HEAD(&rt->rt_uncached);
2324 dst_free(new);
2325 }
2326
2327 dst_release(dst_orig);
2328
2329 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2330 }
2331
2332 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2333 const struct sock *sk)
2334 {
2335 struct rtable *rt = __ip_route_output_key(net, flp4);
2336
2337 if (IS_ERR(rt))
2338 return rt;
2339
2340 if (flp4->flowi4_proto)
2341 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2342 flowi4_to_flowi(flp4),
2343 sk, 0);
2344
2345 return rt;
2346 }
2347 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2348
2349 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, u32 table_id,
2350 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2351 u32 seq, int event, int nowait, unsigned int flags)
2352 {
2353 struct rtable *rt = skb_rtable(skb);
2354 struct rtmsg *r;
2355 struct nlmsghdr *nlh;
2356 unsigned long expires = 0;
2357 u32 error;
2358 u32 metrics[RTAX_MAX];
2359
2360 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2361 if (!nlh)
2362 return -EMSGSIZE;
2363
2364 r = nlmsg_data(nlh);
2365 r->rtm_family = AF_INET;
2366 r->rtm_dst_len = 32;
2367 r->rtm_src_len = 0;
2368 r->rtm_tos = fl4->flowi4_tos;
2369 r->rtm_table = table_id;
2370 if (nla_put_u32(skb, RTA_TABLE, table_id))
2371 goto nla_put_failure;
2372 r->rtm_type = rt->rt_type;
2373 r->rtm_scope = RT_SCOPE_UNIVERSE;
2374 r->rtm_protocol = RTPROT_UNSPEC;
2375 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2376 if (rt->rt_flags & RTCF_NOTIFY)
2377 r->rtm_flags |= RTM_F_NOTIFY;
2378 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2379 r->rtm_flags |= RTCF_DOREDIRECT;
2380
2381 if (nla_put_in_addr(skb, RTA_DST, dst))
2382 goto nla_put_failure;
2383 if (src) {
2384 r->rtm_src_len = 32;
2385 if (nla_put_in_addr(skb, RTA_SRC, src))
2386 goto nla_put_failure;
2387 }
2388 if (rt->dst.dev &&
2389 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2390 goto nla_put_failure;
2391 #ifdef CONFIG_IP_ROUTE_CLASSID
2392 if (rt->dst.tclassid &&
2393 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2394 goto nla_put_failure;
2395 #endif
2396 if (!rt_is_input_route(rt) &&
2397 fl4->saddr != src) {
2398 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2399 goto nla_put_failure;
2400 }
2401 if (rt->rt_uses_gateway &&
2402 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2403 goto nla_put_failure;
2404
2405 expires = rt->dst.expires;
2406 if (expires) {
2407 unsigned long now = jiffies;
2408
2409 if (time_before(now, expires))
2410 expires -= now;
2411 else
2412 expires = 0;
2413 }
2414
2415 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2416 if (rt->rt_pmtu && expires)
2417 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2418 if (rtnetlink_put_metrics(skb, metrics) < 0)
2419 goto nla_put_failure;
2420
2421 if (fl4->flowi4_mark &&
2422 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2423 goto nla_put_failure;
2424
2425 error = rt->dst.error;
2426
2427 if (rt_is_input_route(rt)) {
2428 #ifdef CONFIG_IP_MROUTE
2429 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2430 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2431 int err = ipmr_get_route(net, skb,
2432 fl4->saddr, fl4->daddr,
2433 r, nowait);
2434 if (err <= 0) {
2435 if (!nowait) {
2436 if (err == 0)
2437 return 0;
2438 goto nla_put_failure;
2439 } else {
2440 if (err == -EMSGSIZE)
2441 goto nla_put_failure;
2442 error = err;
2443 }
2444 }
2445 } else
2446 #endif
2447 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2448 goto nla_put_failure;
2449 }
2450
2451 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2452 goto nla_put_failure;
2453
2454 nlmsg_end(skb, nlh);
2455 return 0;
2456
2457 nla_put_failure:
2458 nlmsg_cancel(skb, nlh);
2459 return -EMSGSIZE;
2460 }
2461
2462 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2463 {
2464 struct net *net = sock_net(in_skb->sk);
2465 struct rtmsg *rtm;
2466 struct nlattr *tb[RTA_MAX+1];
2467 struct rtable *rt = NULL;
2468 struct flowi4 fl4;
2469 __be32 dst = 0;
2470 __be32 src = 0;
2471 u32 iif;
2472 int err;
2473 int mark;
2474 struct sk_buff *skb;
2475 u32 table_id = RT_TABLE_MAIN;
2476
2477 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2478 if (err < 0)
2479 goto errout;
2480
2481 rtm = nlmsg_data(nlh);
2482
2483 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2484 if (!skb) {
2485 err = -ENOBUFS;
2486 goto errout;
2487 }
2488
2489 /* Reserve room for dummy headers, this skb can pass
2490 through good chunk of routing engine.
2491 */
2492 skb_reset_mac_header(skb);
2493 skb_reset_network_header(skb);
2494
2495 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2496 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2497 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2498
2499 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2500 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2501 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2502 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2503
2504 memset(&fl4, 0, sizeof(fl4));
2505 fl4.daddr = dst;
2506 fl4.saddr = src;
2507 fl4.flowi4_tos = rtm->rtm_tos;
2508 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2509 fl4.flowi4_mark = mark;
2510
2511 if (netif_index_is_l3_master(net, fl4.flowi4_oif))
2512 fl4.flowi4_flags = FLOWI_FLAG_L3MDEV_SRC | FLOWI_FLAG_SKIP_NH_OIF;
2513
2514 if (iif) {
2515 struct net_device *dev;
2516
2517 dev = __dev_get_by_index(net, iif);
2518 if (!dev) {
2519 err = -ENODEV;
2520 goto errout_free;
2521 }
2522
2523 skb->protocol = htons(ETH_P_IP);
2524 skb->dev = dev;
2525 skb->mark = mark;
2526 local_bh_disable();
2527 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2528 local_bh_enable();
2529
2530 rt = skb_rtable(skb);
2531 if (err == 0 && rt->dst.error)
2532 err = -rt->dst.error;
2533 } else {
2534 rt = ip_route_output_key(net, &fl4);
2535
2536 err = 0;
2537 if (IS_ERR(rt))
2538 err = PTR_ERR(rt);
2539 }
2540
2541 if (err)
2542 goto errout_free;
2543
2544 skb_dst_set(skb, &rt->dst);
2545 if (rtm->rtm_flags & RTM_F_NOTIFY)
2546 rt->rt_flags |= RTCF_NOTIFY;
2547
2548 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
2549 table_id = rt->rt_table_id;
2550
2551 err = rt_fill_info(net, dst, src, table_id, &fl4, skb,
2552 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2553 RTM_NEWROUTE, 0, 0);
2554 if (err < 0)
2555 goto errout_free;
2556
2557 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2558 errout:
2559 return err;
2560
2561 errout_free:
2562 kfree_skb(skb);
2563 goto errout;
2564 }
2565
2566 void ip_rt_multicast_event(struct in_device *in_dev)
2567 {
2568 rt_cache_flush(dev_net(in_dev->dev));
2569 }
2570
2571 #ifdef CONFIG_SYSCTL
2572 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2573 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2574 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2575 static int ip_rt_gc_elasticity __read_mostly = 8;
2576
2577 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2578 void __user *buffer,
2579 size_t *lenp, loff_t *ppos)
2580 {
2581 struct net *net = (struct net *)__ctl->extra1;
2582
2583 if (write) {
2584 rt_cache_flush(net);
2585 fnhe_genid_bump(net);
2586 return 0;
2587 }
2588
2589 return -EINVAL;
2590 }
2591
2592 static struct ctl_table ipv4_route_table[] = {
2593 {
2594 .procname = "gc_thresh",
2595 .data = &ipv4_dst_ops.gc_thresh,
2596 .maxlen = sizeof(int),
2597 .mode = 0644,
2598 .proc_handler = proc_dointvec,
2599 },
2600 {
2601 .procname = "max_size",
2602 .data = &ip_rt_max_size,
2603 .maxlen = sizeof(int),
2604 .mode = 0644,
2605 .proc_handler = proc_dointvec,
2606 },
2607 {
2608 /* Deprecated. Use gc_min_interval_ms */
2609
2610 .procname = "gc_min_interval",
2611 .data = &ip_rt_gc_min_interval,
2612 .maxlen = sizeof(int),
2613 .mode = 0644,
2614 .proc_handler = proc_dointvec_jiffies,
2615 },
2616 {
2617 .procname = "gc_min_interval_ms",
2618 .data = &ip_rt_gc_min_interval,
2619 .maxlen = sizeof(int),
2620 .mode = 0644,
2621 .proc_handler = proc_dointvec_ms_jiffies,
2622 },
2623 {
2624 .procname = "gc_timeout",
2625 .data = &ip_rt_gc_timeout,
2626 .maxlen = sizeof(int),
2627 .mode = 0644,
2628 .proc_handler = proc_dointvec_jiffies,
2629 },
2630 {
2631 .procname = "gc_interval",
2632 .data = &ip_rt_gc_interval,
2633 .maxlen = sizeof(int),
2634 .mode = 0644,
2635 .proc_handler = proc_dointvec_jiffies,
2636 },
2637 {
2638 .procname = "redirect_load",
2639 .data = &ip_rt_redirect_load,
2640 .maxlen = sizeof(int),
2641 .mode = 0644,
2642 .proc_handler = proc_dointvec,
2643 },
2644 {
2645 .procname = "redirect_number",
2646 .data = &ip_rt_redirect_number,
2647 .maxlen = sizeof(int),
2648 .mode = 0644,
2649 .proc_handler = proc_dointvec,
2650 },
2651 {
2652 .procname = "redirect_silence",
2653 .data = &ip_rt_redirect_silence,
2654 .maxlen = sizeof(int),
2655 .mode = 0644,
2656 .proc_handler = proc_dointvec,
2657 },
2658 {
2659 .procname = "error_cost",
2660 .data = &ip_rt_error_cost,
2661 .maxlen = sizeof(int),
2662 .mode = 0644,
2663 .proc_handler = proc_dointvec,
2664 },
2665 {
2666 .procname = "error_burst",
2667 .data = &ip_rt_error_burst,
2668 .maxlen = sizeof(int),
2669 .mode = 0644,
2670 .proc_handler = proc_dointvec,
2671 },
2672 {
2673 .procname = "gc_elasticity",
2674 .data = &ip_rt_gc_elasticity,
2675 .maxlen = sizeof(int),
2676 .mode = 0644,
2677 .proc_handler = proc_dointvec,
2678 },
2679 {
2680 .procname = "mtu_expires",
2681 .data = &ip_rt_mtu_expires,
2682 .maxlen = sizeof(int),
2683 .mode = 0644,
2684 .proc_handler = proc_dointvec_jiffies,
2685 },
2686 {
2687 .procname = "min_pmtu",
2688 .data = &ip_rt_min_pmtu,
2689 .maxlen = sizeof(int),
2690 .mode = 0644,
2691 .proc_handler = proc_dointvec,
2692 },
2693 {
2694 .procname = "min_adv_mss",
2695 .data = &ip_rt_min_advmss,
2696 .maxlen = sizeof(int),
2697 .mode = 0644,
2698 .proc_handler = proc_dointvec,
2699 },
2700 { }
2701 };
2702
2703 static struct ctl_table ipv4_route_flush_table[] = {
2704 {
2705 .procname = "flush",
2706 .maxlen = sizeof(int),
2707 .mode = 0200,
2708 .proc_handler = ipv4_sysctl_rtcache_flush,
2709 },
2710 { },
2711 };
2712
2713 static __net_init int sysctl_route_net_init(struct net *net)
2714 {
2715 struct ctl_table *tbl;
2716
2717 tbl = ipv4_route_flush_table;
2718 if (!net_eq(net, &init_net)) {
2719 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2720 if (!tbl)
2721 goto err_dup;
2722
2723 /* Don't export sysctls to unprivileged users */
2724 if (net->user_ns != &init_user_ns)
2725 tbl[0].procname = NULL;
2726 }
2727 tbl[0].extra1 = net;
2728
2729 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2730 if (!net->ipv4.route_hdr)
2731 goto err_reg;
2732 return 0;
2733
2734 err_reg:
2735 if (tbl != ipv4_route_flush_table)
2736 kfree(tbl);
2737 err_dup:
2738 return -ENOMEM;
2739 }
2740
2741 static __net_exit void sysctl_route_net_exit(struct net *net)
2742 {
2743 struct ctl_table *tbl;
2744
2745 tbl = net->ipv4.route_hdr->ctl_table_arg;
2746 unregister_net_sysctl_table(net->ipv4.route_hdr);
2747 BUG_ON(tbl == ipv4_route_flush_table);
2748 kfree(tbl);
2749 }
2750
2751 static __net_initdata struct pernet_operations sysctl_route_ops = {
2752 .init = sysctl_route_net_init,
2753 .exit = sysctl_route_net_exit,
2754 };
2755 #endif
2756
2757 static __net_init int rt_genid_init(struct net *net)
2758 {
2759 atomic_set(&net->ipv4.rt_genid, 0);
2760 atomic_set(&net->fnhe_genid, 0);
2761 get_random_bytes(&net->ipv4.dev_addr_genid,
2762 sizeof(net->ipv4.dev_addr_genid));
2763 return 0;
2764 }
2765
2766 static __net_initdata struct pernet_operations rt_genid_ops = {
2767 .init = rt_genid_init,
2768 };
2769
2770 static int __net_init ipv4_inetpeer_init(struct net *net)
2771 {
2772 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2773
2774 if (!bp)
2775 return -ENOMEM;
2776 inet_peer_base_init(bp);
2777 net->ipv4.peers = bp;
2778 return 0;
2779 }
2780
2781 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2782 {
2783 struct inet_peer_base *bp = net->ipv4.peers;
2784
2785 net->ipv4.peers = NULL;
2786 inetpeer_invalidate_tree(bp);
2787 kfree(bp);
2788 }
2789
2790 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2791 .init = ipv4_inetpeer_init,
2792 .exit = ipv4_inetpeer_exit,
2793 };
2794
2795 #ifdef CONFIG_IP_ROUTE_CLASSID
2796 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2797 #endif /* CONFIG_IP_ROUTE_CLASSID */
2798
2799 int __init ip_rt_init(void)
2800 {
2801 int rc = 0;
2802 int cpu;
2803
2804 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2805 if (!ip_idents)
2806 panic("IP: failed to allocate ip_idents\n");
2807
2808 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2809
2810 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
2811 if (!ip_tstamps)
2812 panic("IP: failed to allocate ip_tstamps\n");
2813
2814 for_each_possible_cpu(cpu) {
2815 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
2816
2817 INIT_LIST_HEAD(&ul->head);
2818 spin_lock_init(&ul->lock);
2819 }
2820 #ifdef CONFIG_IP_ROUTE_CLASSID
2821 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2822 if (!ip_rt_acct)
2823 panic("IP: failed to allocate ip_rt_acct\n");
2824 #endif
2825
2826 ipv4_dst_ops.kmem_cachep =
2827 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2828 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2829
2830 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2831
2832 if (dst_entries_init(&ipv4_dst_ops) < 0)
2833 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2834
2835 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2836 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2837
2838 ipv4_dst_ops.gc_thresh = ~0;
2839 ip_rt_max_size = INT_MAX;
2840
2841 devinet_init();
2842 ip_fib_init();
2843
2844 if (ip_rt_proc_init())
2845 pr_err("Unable to create route proc files\n");
2846 #ifdef CONFIG_XFRM
2847 xfrm_init();
2848 xfrm4_init();
2849 #endif
2850 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2851
2852 #ifdef CONFIG_SYSCTL
2853 register_pernet_subsys(&sysctl_route_ops);
2854 #endif
2855 register_pernet_subsys(&rt_genid_ops);
2856 register_pernet_subsys(&ipv4_inetpeer_ops);
2857 return rc;
2858 }
2859
2860 #ifdef CONFIG_SYSCTL
2861 /*
2862 * We really need to sanitize the damn ipv4 init order, then all
2863 * this nonsense will go away.
2864 */
2865 void __init ip_static_sysctl_init(void)
2866 {
2867 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2868 }
2869 #endif
Linux kernel - Deliverables
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