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Merge remote-tracking branch 'iommu/next'
[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 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
133 /*
134 * Interface to generic destination cache.
135 */
136
137 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
138 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
139 static unsigned int ipv4_mtu(const struct dst_entry *dst);
140 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
141 static void ipv4_link_failure(struct sk_buff *skb);
142 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
143 struct sk_buff *skb, u32 mtu);
144 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
145 struct sk_buff *skb);
146 static void ipv4_dst_destroy(struct dst_entry *dst);
147
148 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
149 {
150 WARN_ON(1);
151 return NULL;
152 }
153
154 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
155 struct sk_buff *skb,
156 const void *daddr);
157
158 static struct dst_ops ipv4_dst_ops = {
159 .family = AF_INET,
160 .check = ipv4_dst_check,
161 .default_advmss = ipv4_default_advmss,
162 .mtu = ipv4_mtu,
163 .cow_metrics = ipv4_cow_metrics,
164 .destroy = ipv4_dst_destroy,
165 .negative_advice = ipv4_negative_advice,
166 .link_failure = ipv4_link_failure,
167 .update_pmtu = ip_rt_update_pmtu,
168 .redirect = ip_do_redirect,
169 .local_out = __ip_local_out,
170 .neigh_lookup = ipv4_neigh_lookup,
171 };
172
173 #define ECN_OR_COST(class) TC_PRIO_##class
174
175 const __u8 ip_tos2prio[16] = {
176 TC_PRIO_BESTEFFORT,
177 ECN_OR_COST(BESTEFFORT),
178 TC_PRIO_BESTEFFORT,
179 ECN_OR_COST(BESTEFFORT),
180 TC_PRIO_BULK,
181 ECN_OR_COST(BULK),
182 TC_PRIO_BULK,
183 ECN_OR_COST(BULK),
184 TC_PRIO_INTERACTIVE,
185 ECN_OR_COST(INTERACTIVE),
186 TC_PRIO_INTERACTIVE,
187 ECN_OR_COST(INTERACTIVE),
188 TC_PRIO_INTERACTIVE_BULK,
189 ECN_OR_COST(INTERACTIVE_BULK),
190 TC_PRIO_INTERACTIVE_BULK,
191 ECN_OR_COST(INTERACTIVE_BULK)
192 };
193 EXPORT_SYMBOL(ip_tos2prio);
194
195 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
196 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
197
198 #ifdef CONFIG_PROC_FS
199 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
200 {
201 if (*pos)
202 return NULL;
203 return SEQ_START_TOKEN;
204 }
205
206 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
207 {
208 ++*pos;
209 return NULL;
210 }
211
212 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
213 {
214 }
215
216 static int rt_cache_seq_show(struct seq_file *seq, void *v)
217 {
218 if (v == SEQ_START_TOKEN)
219 seq_printf(seq, "%-127s\n",
220 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
221 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
222 "HHUptod\tSpecDst");
223 return 0;
224 }
225
226 static const struct seq_operations rt_cache_seq_ops = {
227 .start = rt_cache_seq_start,
228 .next = rt_cache_seq_next,
229 .stop = rt_cache_seq_stop,
230 .show = rt_cache_seq_show,
231 };
232
233 static int rt_cache_seq_open(struct inode *inode, struct file *file)
234 {
235 return seq_open(file, &rt_cache_seq_ops);
236 }
237
238 static const struct file_operations rt_cache_seq_fops = {
239 .owner = THIS_MODULE,
240 .open = rt_cache_seq_open,
241 .read = seq_read,
242 .llseek = seq_lseek,
243 .release = seq_release,
244 };
245
246
247 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
248 {
249 int cpu;
250
251 if (*pos == 0)
252 return SEQ_START_TOKEN;
253
254 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
255 if (!cpu_possible(cpu))
256 continue;
257 *pos = cpu+1;
258 return &per_cpu(rt_cache_stat, cpu);
259 }
260 return NULL;
261 }
262
263 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
264 {
265 int cpu;
266
267 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
268 if (!cpu_possible(cpu))
269 continue;
270 *pos = cpu+1;
271 return &per_cpu(rt_cache_stat, cpu);
272 }
273 return NULL;
274
275 }
276
277 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
278 {
279
280 }
281
282 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
283 {
284 struct rt_cache_stat *st = v;
285
286 if (v == SEQ_START_TOKEN) {
287 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");
288 return 0;
289 }
290
291 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
292 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
293 dst_entries_get_slow(&ipv4_dst_ops),
294 0, /* st->in_hit */
295 st->in_slow_tot,
296 st->in_slow_mc,
297 st->in_no_route,
298 st->in_brd,
299 st->in_martian_dst,
300 st->in_martian_src,
301
302 0, /* st->out_hit */
303 st->out_slow_tot,
304 st->out_slow_mc,
305
306 0, /* st->gc_total */
307 0, /* st->gc_ignored */
308 0, /* st->gc_goal_miss */
309 0, /* st->gc_dst_overflow */
310 0, /* st->in_hlist_search */
311 0 /* st->out_hlist_search */
312 );
313 return 0;
314 }
315
316 static const struct seq_operations rt_cpu_seq_ops = {
317 .start = rt_cpu_seq_start,
318 .next = rt_cpu_seq_next,
319 .stop = rt_cpu_seq_stop,
320 .show = rt_cpu_seq_show,
321 };
322
323
324 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
325 {
326 return seq_open(file, &rt_cpu_seq_ops);
327 }
328
329 static const struct file_operations rt_cpu_seq_fops = {
330 .owner = THIS_MODULE,
331 .open = rt_cpu_seq_open,
332 .read = seq_read,
333 .llseek = seq_lseek,
334 .release = seq_release,
335 };
336
337 #ifdef CONFIG_IP_ROUTE_CLASSID
338 static int rt_acct_proc_show(struct seq_file *m, void *v)
339 {
340 struct ip_rt_acct *dst, *src;
341 unsigned int i, j;
342
343 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
344 if (!dst)
345 return -ENOMEM;
346
347 for_each_possible_cpu(i) {
348 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
349 for (j = 0; j < 256; j++) {
350 dst[j].o_bytes += src[j].o_bytes;
351 dst[j].o_packets += src[j].o_packets;
352 dst[j].i_bytes += src[j].i_bytes;
353 dst[j].i_packets += src[j].i_packets;
354 }
355 }
356
357 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
358 kfree(dst);
359 return 0;
360 }
361
362 static int rt_acct_proc_open(struct inode *inode, struct file *file)
363 {
364 return single_open(file, rt_acct_proc_show, NULL);
365 }
366
367 static const struct file_operations rt_acct_proc_fops = {
368 .owner = THIS_MODULE,
369 .open = rt_acct_proc_open,
370 .read = seq_read,
371 .llseek = seq_lseek,
372 .release = single_release,
373 };
374 #endif
375
376 static int __net_init ip_rt_do_proc_init(struct net *net)
377 {
378 struct proc_dir_entry *pde;
379
380 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
381 &rt_cache_seq_fops);
382 if (!pde)
383 goto err1;
384
385 pde = proc_create("rt_cache", S_IRUGO,
386 net->proc_net_stat, &rt_cpu_seq_fops);
387 if (!pde)
388 goto err2;
389
390 #ifdef CONFIG_IP_ROUTE_CLASSID
391 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
392 if (!pde)
393 goto err3;
394 #endif
395 return 0;
396
397 #ifdef CONFIG_IP_ROUTE_CLASSID
398 err3:
399 remove_proc_entry("rt_cache", net->proc_net_stat);
400 #endif
401 err2:
402 remove_proc_entry("rt_cache", net->proc_net);
403 err1:
404 return -ENOMEM;
405 }
406
407 static void __net_exit ip_rt_do_proc_exit(struct net *net)
408 {
409 remove_proc_entry("rt_cache", net->proc_net_stat);
410 remove_proc_entry("rt_cache", net->proc_net);
411 #ifdef CONFIG_IP_ROUTE_CLASSID
412 remove_proc_entry("rt_acct", net->proc_net);
413 #endif
414 }
415
416 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
417 .init = ip_rt_do_proc_init,
418 .exit = ip_rt_do_proc_exit,
419 };
420
421 static int __init ip_rt_proc_init(void)
422 {
423 return register_pernet_subsys(&ip_rt_proc_ops);
424 }
425
426 #else
427 static inline int ip_rt_proc_init(void)
428 {
429 return 0;
430 }
431 #endif /* CONFIG_PROC_FS */
432
433 static inline bool rt_is_expired(const struct rtable *rth)
434 {
435 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
436 }
437
438 void rt_cache_flush(struct net *net)
439 {
440 rt_genid_bump_ipv4(net);
441 }
442
443 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
444 struct sk_buff *skb,
445 const void *daddr)
446 {
447 struct net_device *dev = dst->dev;
448 const __be32 *pkey = daddr;
449 const struct rtable *rt;
450 struct neighbour *n;
451
452 rt = (const struct rtable *) dst;
453 if (rt->rt_gateway)
454 pkey = (const __be32 *) &rt->rt_gateway;
455 else if (skb)
456 pkey = &ip_hdr(skb)->daddr;
457
458 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
459 if (n)
460 return n;
461 return neigh_create(&arp_tbl, pkey, dev);
462 }
463
464 #define IP_IDENTS_SZ 2048u
465
466 static atomic_t *ip_idents __read_mostly;
467 static u32 *ip_tstamps __read_mostly;
468
469 /* In order to protect privacy, we add a perturbation to identifiers
470 * if one generator is seldom used. This makes hard for an attacker
471 * to infer how many packets were sent between two points in time.
472 */
473 u32 ip_idents_reserve(u32 hash, int segs)
474 {
475 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
476 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
477 u32 old = ACCESS_ONCE(*p_tstamp);
478 u32 now = (u32)jiffies;
479 u32 delta = 0;
480
481 if (old != now && cmpxchg(p_tstamp, old, now) == old)
482 delta = prandom_u32_max(now - old);
483
484 return atomic_add_return(segs + delta, p_id) - segs;
485 }
486 EXPORT_SYMBOL(ip_idents_reserve);
487
488 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
489 {
490 static u32 ip_idents_hashrnd __read_mostly;
491 u32 hash, id;
492
493 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
494
495 hash = jhash_3words((__force u32)iph->daddr,
496 (__force u32)iph->saddr,
497 iph->protocol ^ net_hash_mix(net),
498 ip_idents_hashrnd);
499 id = ip_idents_reserve(hash, segs);
500 iph->id = htons(id);
501 }
502 EXPORT_SYMBOL(__ip_select_ident);
503
504 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
505 const struct iphdr *iph,
506 int oif, u8 tos,
507 u8 prot, u32 mark, int flow_flags)
508 {
509 if (sk) {
510 const struct inet_sock *inet = inet_sk(sk);
511
512 oif = sk->sk_bound_dev_if;
513 mark = sk->sk_mark;
514 tos = RT_CONN_FLAGS(sk);
515 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
516 }
517 flowi4_init_output(fl4, oif, mark, tos,
518 RT_SCOPE_UNIVERSE, prot,
519 flow_flags,
520 iph->daddr, iph->saddr, 0, 0);
521 }
522
523 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
524 const struct sock *sk)
525 {
526 const struct iphdr *iph = ip_hdr(skb);
527 int oif = skb->dev->ifindex;
528 u8 tos = RT_TOS(iph->tos);
529 u8 prot = iph->protocol;
530 u32 mark = skb->mark;
531
532 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
533 }
534
535 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
536 {
537 const struct inet_sock *inet = inet_sk(sk);
538 const struct ip_options_rcu *inet_opt;
539 __be32 daddr = inet->inet_daddr;
540
541 rcu_read_lock();
542 inet_opt = rcu_dereference(inet->inet_opt);
543 if (inet_opt && inet_opt->opt.srr)
544 daddr = inet_opt->opt.faddr;
545 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
546 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
547 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
548 inet_sk_flowi_flags(sk),
549 daddr, inet->inet_saddr, 0, 0);
550 rcu_read_unlock();
551 }
552
553 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
554 const struct sk_buff *skb)
555 {
556 if (skb)
557 build_skb_flow_key(fl4, skb, sk);
558 else
559 build_sk_flow_key(fl4, sk);
560 }
561
562 static inline void rt_free(struct rtable *rt)
563 {
564 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
565 }
566
567 static DEFINE_SPINLOCK(fnhe_lock);
568
569 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
570 {
571 struct rtable *rt;
572
573 rt = rcu_dereference(fnhe->fnhe_rth_input);
574 if (rt) {
575 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
576 rt_free(rt);
577 }
578 rt = rcu_dereference(fnhe->fnhe_rth_output);
579 if (rt) {
580 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
581 rt_free(rt);
582 }
583 }
584
585 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
586 {
587 struct fib_nh_exception *fnhe, *oldest;
588
589 oldest = rcu_dereference(hash->chain);
590 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
591 fnhe = rcu_dereference(fnhe->fnhe_next)) {
592 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
593 oldest = fnhe;
594 }
595 fnhe_flush_routes(oldest);
596 return oldest;
597 }
598
599 static inline u32 fnhe_hashfun(__be32 daddr)
600 {
601 static u32 fnhe_hashrnd __read_mostly;
602 u32 hval;
603
604 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
605 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
606 return hash_32(hval, FNHE_HASH_SHIFT);
607 }
608
609 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
610 {
611 rt->rt_pmtu = fnhe->fnhe_pmtu;
612 rt->dst.expires = fnhe->fnhe_expires;
613
614 if (fnhe->fnhe_gw) {
615 rt->rt_flags |= RTCF_REDIRECTED;
616 rt->rt_gateway = fnhe->fnhe_gw;
617 rt->rt_uses_gateway = 1;
618 }
619 }
620
621 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
622 u32 pmtu, unsigned long expires)
623 {
624 struct fnhe_hash_bucket *hash;
625 struct fib_nh_exception *fnhe;
626 struct rtable *rt;
627 unsigned int i;
628 int depth;
629 u32 hval = fnhe_hashfun(daddr);
630
631 spin_lock_bh(&fnhe_lock);
632
633 hash = rcu_dereference(nh->nh_exceptions);
634 if (!hash) {
635 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
636 if (!hash)
637 goto out_unlock;
638 rcu_assign_pointer(nh->nh_exceptions, hash);
639 }
640
641 hash += hval;
642
643 depth = 0;
644 for (fnhe = rcu_dereference(hash->chain); fnhe;
645 fnhe = rcu_dereference(fnhe->fnhe_next)) {
646 if (fnhe->fnhe_daddr == daddr)
647 break;
648 depth++;
649 }
650
651 if (fnhe) {
652 if (gw)
653 fnhe->fnhe_gw = gw;
654 if (pmtu) {
655 fnhe->fnhe_pmtu = pmtu;
656 fnhe->fnhe_expires = max(1UL, expires);
657 }
658 /* Update all cached dsts too */
659 rt = rcu_dereference(fnhe->fnhe_rth_input);
660 if (rt)
661 fill_route_from_fnhe(rt, fnhe);
662 rt = rcu_dereference(fnhe->fnhe_rth_output);
663 if (rt)
664 fill_route_from_fnhe(rt, fnhe);
665 } else {
666 if (depth > FNHE_RECLAIM_DEPTH)
667 fnhe = fnhe_oldest(hash);
668 else {
669 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
670 if (!fnhe)
671 goto out_unlock;
672
673 fnhe->fnhe_next = hash->chain;
674 rcu_assign_pointer(hash->chain, fnhe);
675 }
676 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
677 fnhe->fnhe_daddr = daddr;
678 fnhe->fnhe_gw = gw;
679 fnhe->fnhe_pmtu = pmtu;
680 fnhe->fnhe_expires = expires;
681
682 /* Exception created; mark the cached routes for the nexthop
683 * stale, so anyone caching it rechecks if this exception
684 * applies to them.
685 */
686 rt = rcu_dereference(nh->nh_rth_input);
687 if (rt)
688 rt->dst.obsolete = DST_OBSOLETE_KILL;
689
690 for_each_possible_cpu(i) {
691 struct rtable __rcu **prt;
692 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
693 rt = rcu_dereference(*prt);
694 if (rt)
695 rt->dst.obsolete = DST_OBSOLETE_KILL;
696 }
697 }
698
699 fnhe->fnhe_stamp = jiffies;
700
701 out_unlock:
702 spin_unlock_bh(&fnhe_lock);
703 }
704
705 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
706 bool kill_route)
707 {
708 __be32 new_gw = icmp_hdr(skb)->un.gateway;
709 __be32 old_gw = ip_hdr(skb)->saddr;
710 struct net_device *dev = skb->dev;
711 struct in_device *in_dev;
712 struct fib_result res;
713 struct neighbour *n;
714 struct net *net;
715
716 switch (icmp_hdr(skb)->code & 7) {
717 case ICMP_REDIR_NET:
718 case ICMP_REDIR_NETTOS:
719 case ICMP_REDIR_HOST:
720 case ICMP_REDIR_HOSTTOS:
721 break;
722
723 default:
724 return;
725 }
726
727 if (rt->rt_gateway != old_gw)
728 return;
729
730 in_dev = __in_dev_get_rcu(dev);
731 if (!in_dev)
732 return;
733
734 net = dev_net(dev);
735 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
736 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
737 ipv4_is_zeronet(new_gw))
738 goto reject_redirect;
739
740 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
741 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
742 goto reject_redirect;
743 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
744 goto reject_redirect;
745 } else {
746 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
747 goto reject_redirect;
748 }
749
750 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
751 if (!IS_ERR(n)) {
752 if (!(n->nud_state & NUD_VALID)) {
753 neigh_event_send(n, NULL);
754 } else {
755 if (fib_lookup(net, fl4, &res, 0) == 0) {
756 struct fib_nh *nh = &FIB_RES_NH(res);
757
758 update_or_create_fnhe(nh, fl4->daddr, new_gw,
759 0, jiffies + ip_rt_gc_timeout);
760 }
761 if (kill_route)
762 rt->dst.obsolete = DST_OBSOLETE_KILL;
763 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
764 }
765 neigh_release(n);
766 }
767 return;
768
769 reject_redirect:
770 #ifdef CONFIG_IP_ROUTE_VERBOSE
771 if (IN_DEV_LOG_MARTIANS(in_dev)) {
772 const struct iphdr *iph = (const struct iphdr *) skb->data;
773 __be32 daddr = iph->daddr;
774 __be32 saddr = iph->saddr;
775
776 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
777 " Advised path = %pI4 -> %pI4\n",
778 &old_gw, dev->name, &new_gw,
779 &saddr, &daddr);
780 }
781 #endif
782 ;
783 }
784
785 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
786 {
787 struct rtable *rt;
788 struct flowi4 fl4;
789 const struct iphdr *iph = (const struct iphdr *) skb->data;
790 int oif = skb->dev->ifindex;
791 u8 tos = RT_TOS(iph->tos);
792 u8 prot = iph->protocol;
793 u32 mark = skb->mark;
794
795 rt = (struct rtable *) dst;
796
797 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
798 __ip_do_redirect(rt, skb, &fl4, true);
799 }
800
801 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
802 {
803 struct rtable *rt = (struct rtable *)dst;
804 struct dst_entry *ret = dst;
805
806 if (rt) {
807 if (dst->obsolete > 0) {
808 ip_rt_put(rt);
809 ret = NULL;
810 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
811 rt->dst.expires) {
812 ip_rt_put(rt);
813 ret = NULL;
814 }
815 }
816 return ret;
817 }
818
819 /*
820 * Algorithm:
821 * 1. The first ip_rt_redirect_number redirects are sent
822 * with exponential backoff, then we stop sending them at all,
823 * assuming that the host ignores our redirects.
824 * 2. If we did not see packets requiring redirects
825 * during ip_rt_redirect_silence, we assume that the host
826 * forgot redirected route and start to send redirects again.
827 *
828 * This algorithm is much cheaper and more intelligent than dumb load limiting
829 * in icmp.c.
830 *
831 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
832 * and "frag. need" (breaks PMTU discovery) in icmp.c.
833 */
834
835 void ip_rt_send_redirect(struct sk_buff *skb)
836 {
837 struct rtable *rt = skb_rtable(skb);
838 struct in_device *in_dev;
839 struct inet_peer *peer;
840 struct net *net;
841 int log_martians;
842 int vif;
843
844 rcu_read_lock();
845 in_dev = __in_dev_get_rcu(rt->dst.dev);
846 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
847 rcu_read_unlock();
848 return;
849 }
850 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
851 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
852 rcu_read_unlock();
853
854 net = dev_net(rt->dst.dev);
855 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
856 if (!peer) {
857 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
858 rt_nexthop(rt, ip_hdr(skb)->daddr));
859 return;
860 }
861
862 /* No redirected packets during ip_rt_redirect_silence;
863 * reset the algorithm.
864 */
865 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
866 peer->rate_tokens = 0;
867
868 /* Too many ignored redirects; do not send anything
869 * set dst.rate_last to the last seen redirected packet.
870 */
871 if (peer->rate_tokens >= ip_rt_redirect_number) {
872 peer->rate_last = jiffies;
873 goto out_put_peer;
874 }
875
876 /* Check for load limit; set rate_last to the latest sent
877 * redirect.
878 */
879 if (peer->rate_tokens == 0 ||
880 time_after(jiffies,
881 (peer->rate_last +
882 (ip_rt_redirect_load << peer->rate_tokens)))) {
883 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
884
885 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
886 peer->rate_last = jiffies;
887 ++peer->rate_tokens;
888 #ifdef CONFIG_IP_ROUTE_VERBOSE
889 if (log_martians &&
890 peer->rate_tokens == ip_rt_redirect_number)
891 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
892 &ip_hdr(skb)->saddr, inet_iif(skb),
893 &ip_hdr(skb)->daddr, &gw);
894 #endif
895 }
896 out_put_peer:
897 inet_putpeer(peer);
898 }
899
900 static int ip_error(struct sk_buff *skb)
901 {
902 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
903 struct rtable *rt = skb_rtable(skb);
904 struct inet_peer *peer;
905 unsigned long now;
906 struct net *net;
907 bool send;
908 int code;
909
910 /* IP on this device is disabled. */
911 if (!in_dev)
912 goto out;
913
914 net = dev_net(rt->dst.dev);
915 if (!IN_DEV_FORWARD(in_dev)) {
916 switch (rt->dst.error) {
917 case EHOSTUNREACH:
918 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS);
919 break;
920
921 case ENETUNREACH:
922 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
923 break;
924 }
925 goto out;
926 }
927
928 switch (rt->dst.error) {
929 case EINVAL:
930 default:
931 goto out;
932 case EHOSTUNREACH:
933 code = ICMP_HOST_UNREACH;
934 break;
935 case ENETUNREACH:
936 code = ICMP_NET_UNREACH;
937 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
938 break;
939 case EACCES:
940 code = ICMP_PKT_FILTERED;
941 break;
942 }
943
944 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
945 l3mdev_master_ifindex(skb->dev), 1);
946
947 send = true;
948 if (peer) {
949 now = jiffies;
950 peer->rate_tokens += now - peer->rate_last;
951 if (peer->rate_tokens > ip_rt_error_burst)
952 peer->rate_tokens = ip_rt_error_burst;
953 peer->rate_last = now;
954 if (peer->rate_tokens >= ip_rt_error_cost)
955 peer->rate_tokens -= ip_rt_error_cost;
956 else
957 send = false;
958 inet_putpeer(peer);
959 }
960 if (send)
961 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
962
963 out: kfree_skb(skb);
964 return 0;
965 }
966
967 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
968 {
969 struct dst_entry *dst = &rt->dst;
970 struct fib_result res;
971
972 if (dst_metric_locked(dst, RTAX_MTU))
973 return;
974
975 if (ipv4_mtu(dst) < mtu)
976 return;
977
978 if (mtu < ip_rt_min_pmtu)
979 mtu = ip_rt_min_pmtu;
980
981 if (rt->rt_pmtu == mtu &&
982 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
983 return;
984
985 rcu_read_lock();
986 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
987 struct fib_nh *nh = &FIB_RES_NH(res);
988
989 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
990 jiffies + ip_rt_mtu_expires);
991 }
992 rcu_read_unlock();
993 }
994
995 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
996 struct sk_buff *skb, u32 mtu)
997 {
998 struct rtable *rt = (struct rtable *) dst;
999 struct flowi4 fl4;
1000
1001 ip_rt_build_flow_key(&fl4, sk, skb);
1002 __ip_rt_update_pmtu(rt, &fl4, mtu);
1003 }
1004
1005 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1006 int oif, u32 mark, u8 protocol, int flow_flags)
1007 {
1008 const struct iphdr *iph = (const struct iphdr *) skb->data;
1009 struct flowi4 fl4;
1010 struct rtable *rt;
1011
1012 if (!mark)
1013 mark = IP4_REPLY_MARK(net, skb->mark);
1014
1015 __build_flow_key(&fl4, NULL, iph, oif,
1016 RT_TOS(iph->tos), protocol, mark, flow_flags);
1017 rt = __ip_route_output_key(net, &fl4);
1018 if (!IS_ERR(rt)) {
1019 __ip_rt_update_pmtu(rt, &fl4, mtu);
1020 ip_rt_put(rt);
1021 }
1022 }
1023 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1024
1025 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1026 {
1027 const struct iphdr *iph = (const struct iphdr *) skb->data;
1028 struct flowi4 fl4;
1029 struct rtable *rt;
1030
1031 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1032
1033 if (!fl4.flowi4_mark)
1034 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1035
1036 rt = __ip_route_output_key(sock_net(sk), &fl4);
1037 if (!IS_ERR(rt)) {
1038 __ip_rt_update_pmtu(rt, &fl4, mtu);
1039 ip_rt_put(rt);
1040 }
1041 }
1042
1043 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1044 {
1045 const struct iphdr *iph = (const struct iphdr *) skb->data;
1046 struct flowi4 fl4;
1047 struct rtable *rt;
1048 struct dst_entry *odst = NULL;
1049 bool new = false;
1050
1051 bh_lock_sock(sk);
1052
1053 if (!ip_sk_accept_pmtu(sk))
1054 goto out;
1055
1056 odst = sk_dst_get(sk);
1057
1058 if (sock_owned_by_user(sk) || !odst) {
1059 __ipv4_sk_update_pmtu(skb, sk, mtu);
1060 goto out;
1061 }
1062
1063 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1064
1065 rt = (struct rtable *)odst;
1066 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1067 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1068 if (IS_ERR(rt))
1069 goto out;
1070
1071 new = true;
1072 }
1073
1074 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1075
1076 if (!dst_check(&rt->dst, 0)) {
1077 if (new)
1078 dst_release(&rt->dst);
1079
1080 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1081 if (IS_ERR(rt))
1082 goto out;
1083
1084 new = true;
1085 }
1086
1087 if (new)
1088 sk_dst_set(sk, &rt->dst);
1089
1090 out:
1091 bh_unlock_sock(sk);
1092 dst_release(odst);
1093 }
1094 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1095
1096 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1097 int oif, u32 mark, u8 protocol, int flow_flags)
1098 {
1099 const struct iphdr *iph = (const struct iphdr *) skb->data;
1100 struct flowi4 fl4;
1101 struct rtable *rt;
1102
1103 __build_flow_key(&fl4, NULL, iph, oif,
1104 RT_TOS(iph->tos), protocol, mark, flow_flags);
1105 rt = __ip_route_output_key(net, &fl4);
1106 if (!IS_ERR(rt)) {
1107 __ip_do_redirect(rt, skb, &fl4, false);
1108 ip_rt_put(rt);
1109 }
1110 }
1111 EXPORT_SYMBOL_GPL(ipv4_redirect);
1112
1113 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1114 {
1115 const struct iphdr *iph = (const struct iphdr *) skb->data;
1116 struct flowi4 fl4;
1117 struct rtable *rt;
1118
1119 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1120 rt = __ip_route_output_key(sock_net(sk), &fl4);
1121 if (!IS_ERR(rt)) {
1122 __ip_do_redirect(rt, skb, &fl4, false);
1123 ip_rt_put(rt);
1124 }
1125 }
1126 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1127
1128 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1129 {
1130 struct rtable *rt = (struct rtable *) dst;
1131
1132 /* All IPV4 dsts are created with ->obsolete set to the value
1133 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1134 * into this function always.
1135 *
1136 * When a PMTU/redirect information update invalidates a route,
1137 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1138 * DST_OBSOLETE_DEAD by dst_free().
1139 */
1140 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1141 return NULL;
1142 return dst;
1143 }
1144
1145 static void ipv4_link_failure(struct sk_buff *skb)
1146 {
1147 struct rtable *rt;
1148
1149 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1150
1151 rt = skb_rtable(skb);
1152 if (rt)
1153 dst_set_expires(&rt->dst, 0);
1154 }
1155
1156 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1157 {
1158 pr_debug("%s: %pI4 -> %pI4, %s\n",
1159 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1160 skb->dev ? skb->dev->name : "?");
1161 kfree_skb(skb);
1162 WARN_ON(1);
1163 return 0;
1164 }
1165
1166 /*
1167 We do not cache source address of outgoing interface,
1168 because it is used only by IP RR, TS and SRR options,
1169 so that it out of fast path.
1170
1171 BTW remember: "addr" is allowed to be not aligned
1172 in IP options!
1173 */
1174
1175 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1176 {
1177 __be32 src;
1178
1179 if (rt_is_output_route(rt))
1180 src = ip_hdr(skb)->saddr;
1181 else {
1182 struct fib_result res;
1183 struct flowi4 fl4;
1184 struct iphdr *iph;
1185
1186 iph = ip_hdr(skb);
1187
1188 memset(&fl4, 0, sizeof(fl4));
1189 fl4.daddr = iph->daddr;
1190 fl4.saddr = iph->saddr;
1191 fl4.flowi4_tos = RT_TOS(iph->tos);
1192 fl4.flowi4_oif = rt->dst.dev->ifindex;
1193 fl4.flowi4_iif = skb->dev->ifindex;
1194 fl4.flowi4_mark = skb->mark;
1195
1196 rcu_read_lock();
1197 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1198 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1199 else
1200 src = inet_select_addr(rt->dst.dev,
1201 rt_nexthop(rt, iph->daddr),
1202 RT_SCOPE_UNIVERSE);
1203 rcu_read_unlock();
1204 }
1205 memcpy(addr, &src, 4);
1206 }
1207
1208 #ifdef CONFIG_IP_ROUTE_CLASSID
1209 static void set_class_tag(struct rtable *rt, u32 tag)
1210 {
1211 if (!(rt->dst.tclassid & 0xFFFF))
1212 rt->dst.tclassid |= tag & 0xFFFF;
1213 if (!(rt->dst.tclassid & 0xFFFF0000))
1214 rt->dst.tclassid |= tag & 0xFFFF0000;
1215 }
1216 #endif
1217
1218 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1219 {
1220 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1221
1222 if (advmss == 0) {
1223 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1224 ip_rt_min_advmss);
1225 if (advmss > 65535 - 40)
1226 advmss = 65535 - 40;
1227 }
1228 return advmss;
1229 }
1230
1231 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1232 {
1233 const struct rtable *rt = (const struct rtable *) dst;
1234 unsigned int mtu = rt->rt_pmtu;
1235
1236 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1237 mtu = dst_metric_raw(dst, RTAX_MTU);
1238
1239 if (mtu)
1240 return mtu;
1241
1242 mtu = dst->dev->mtu;
1243
1244 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1245 if (rt->rt_uses_gateway && mtu > 576)
1246 mtu = 576;
1247 }
1248
1249 mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
1250
1251 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
1252 }
1253
1254 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1255 {
1256 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1257 struct fib_nh_exception *fnhe;
1258 u32 hval;
1259
1260 if (!hash)
1261 return NULL;
1262
1263 hval = fnhe_hashfun(daddr);
1264
1265 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1266 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1267 if (fnhe->fnhe_daddr == daddr)
1268 return fnhe;
1269 }
1270 return NULL;
1271 }
1272
1273 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1274 __be32 daddr)
1275 {
1276 bool ret = false;
1277
1278 spin_lock_bh(&fnhe_lock);
1279
1280 if (daddr == fnhe->fnhe_daddr) {
1281 struct rtable __rcu **porig;
1282 struct rtable *orig;
1283 int genid = fnhe_genid(dev_net(rt->dst.dev));
1284
1285 if (rt_is_input_route(rt))
1286 porig = &fnhe->fnhe_rth_input;
1287 else
1288 porig = &fnhe->fnhe_rth_output;
1289 orig = rcu_dereference(*porig);
1290
1291 if (fnhe->fnhe_genid != genid) {
1292 fnhe->fnhe_genid = genid;
1293 fnhe->fnhe_gw = 0;
1294 fnhe->fnhe_pmtu = 0;
1295 fnhe->fnhe_expires = 0;
1296 fnhe_flush_routes(fnhe);
1297 orig = NULL;
1298 }
1299 fill_route_from_fnhe(rt, fnhe);
1300 if (!rt->rt_gateway)
1301 rt->rt_gateway = daddr;
1302
1303 if (!(rt->dst.flags & DST_NOCACHE)) {
1304 rcu_assign_pointer(*porig, rt);
1305 if (orig)
1306 rt_free(orig);
1307 ret = true;
1308 }
1309
1310 fnhe->fnhe_stamp = jiffies;
1311 }
1312 spin_unlock_bh(&fnhe_lock);
1313
1314 return ret;
1315 }
1316
1317 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1318 {
1319 struct rtable *orig, *prev, **p;
1320 bool ret = true;
1321
1322 if (rt_is_input_route(rt)) {
1323 p = (struct rtable **)&nh->nh_rth_input;
1324 } else {
1325 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1326 }
1327 orig = *p;
1328
1329 prev = cmpxchg(p, orig, rt);
1330 if (prev == orig) {
1331 if (orig)
1332 rt_free(orig);
1333 } else
1334 ret = false;
1335
1336 return ret;
1337 }
1338
1339 struct uncached_list {
1340 spinlock_t lock;
1341 struct list_head head;
1342 };
1343
1344 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1345
1346 static void rt_add_uncached_list(struct rtable *rt)
1347 {
1348 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1349
1350 rt->rt_uncached_list = ul;
1351
1352 spin_lock_bh(&ul->lock);
1353 list_add_tail(&rt->rt_uncached, &ul->head);
1354 spin_unlock_bh(&ul->lock);
1355 }
1356
1357 static void ipv4_dst_destroy(struct dst_entry *dst)
1358 {
1359 struct rtable *rt = (struct rtable *) dst;
1360
1361 if (!list_empty(&rt->rt_uncached)) {
1362 struct uncached_list *ul = rt->rt_uncached_list;
1363
1364 spin_lock_bh(&ul->lock);
1365 list_del(&rt->rt_uncached);
1366 spin_unlock_bh(&ul->lock);
1367 }
1368 }
1369
1370 void rt_flush_dev(struct net_device *dev)
1371 {
1372 struct net *net = dev_net(dev);
1373 struct rtable *rt;
1374 int cpu;
1375
1376 for_each_possible_cpu(cpu) {
1377 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1378
1379 spin_lock_bh(&ul->lock);
1380 list_for_each_entry(rt, &ul->head, rt_uncached) {
1381 if (rt->dst.dev != dev)
1382 continue;
1383 rt->dst.dev = net->loopback_dev;
1384 dev_hold(rt->dst.dev);
1385 dev_put(dev);
1386 }
1387 spin_unlock_bh(&ul->lock);
1388 }
1389 }
1390
1391 static bool rt_cache_valid(const struct rtable *rt)
1392 {
1393 return rt &&
1394 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1395 !rt_is_expired(rt);
1396 }
1397
1398 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1399 const struct fib_result *res,
1400 struct fib_nh_exception *fnhe,
1401 struct fib_info *fi, u16 type, u32 itag)
1402 {
1403 bool cached = false;
1404
1405 if (fi) {
1406 struct fib_nh *nh = &FIB_RES_NH(*res);
1407
1408 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1409 rt->rt_gateway = nh->nh_gw;
1410 rt->rt_uses_gateway = 1;
1411 }
1412 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1413 #ifdef CONFIG_IP_ROUTE_CLASSID
1414 rt->dst.tclassid = nh->nh_tclassid;
1415 #endif
1416 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
1417 if (unlikely(fnhe))
1418 cached = rt_bind_exception(rt, fnhe, daddr);
1419 else if (!(rt->dst.flags & DST_NOCACHE))
1420 cached = rt_cache_route(nh, rt);
1421 if (unlikely(!cached)) {
1422 /* Routes we intend to cache in nexthop exception or
1423 * FIB nexthop have the DST_NOCACHE bit clear.
1424 * However, if we are unsuccessful at storing this
1425 * route into the cache we really need to set it.
1426 */
1427 rt->dst.flags |= DST_NOCACHE;
1428 if (!rt->rt_gateway)
1429 rt->rt_gateway = daddr;
1430 rt_add_uncached_list(rt);
1431 }
1432 } else
1433 rt_add_uncached_list(rt);
1434
1435 #ifdef CONFIG_IP_ROUTE_CLASSID
1436 #ifdef CONFIG_IP_MULTIPLE_TABLES
1437 set_class_tag(rt, res->tclassid);
1438 #endif
1439 set_class_tag(rt, itag);
1440 #endif
1441 }
1442
1443 struct rtable *rt_dst_alloc(struct net_device *dev,
1444 unsigned int flags, u16 type,
1445 bool nopolicy, bool noxfrm, bool will_cache)
1446 {
1447 struct rtable *rt;
1448
1449 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1450 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1451 (nopolicy ? DST_NOPOLICY : 0) |
1452 (noxfrm ? DST_NOXFRM : 0));
1453
1454 if (rt) {
1455 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1456 rt->rt_flags = flags;
1457 rt->rt_type = type;
1458 rt->rt_is_input = 0;
1459 rt->rt_iif = 0;
1460 rt->rt_pmtu = 0;
1461 rt->rt_gateway = 0;
1462 rt->rt_uses_gateway = 0;
1463 rt->rt_table_id = 0;
1464 INIT_LIST_HEAD(&rt->rt_uncached);
1465
1466 rt->dst.output = ip_output;
1467 if (flags & RTCF_LOCAL)
1468 rt->dst.input = ip_local_deliver;
1469 }
1470
1471 return rt;
1472 }
1473 EXPORT_SYMBOL(rt_dst_alloc);
1474
1475 /* called in rcu_read_lock() section */
1476 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1477 u8 tos, struct net_device *dev, int our)
1478 {
1479 struct rtable *rth;
1480 struct in_device *in_dev = __in_dev_get_rcu(dev);
1481 unsigned int flags = RTCF_MULTICAST;
1482 u32 itag = 0;
1483 int err;
1484
1485 /* Primary sanity checks. */
1486
1487 if (!in_dev)
1488 return -EINVAL;
1489
1490 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1491 skb->protocol != htons(ETH_P_IP))
1492 goto e_inval;
1493
1494 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1495 goto e_inval;
1496
1497 if (ipv4_is_zeronet(saddr)) {
1498 if (!ipv4_is_local_multicast(daddr))
1499 goto e_inval;
1500 } else {
1501 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1502 in_dev, &itag);
1503 if (err < 0)
1504 goto e_err;
1505 }
1506 if (our)
1507 flags |= RTCF_LOCAL;
1508
1509 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1510 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1511 if (!rth)
1512 goto e_nobufs;
1513
1514 #ifdef CONFIG_IP_ROUTE_CLASSID
1515 rth->dst.tclassid = itag;
1516 #endif
1517 rth->dst.output = ip_rt_bug;
1518 rth->rt_is_input= 1;
1519
1520 #ifdef CONFIG_IP_MROUTE
1521 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1522 rth->dst.input = ip_mr_input;
1523 #endif
1524 RT_CACHE_STAT_INC(in_slow_mc);
1525
1526 skb_dst_set(skb, &rth->dst);
1527 return 0;
1528
1529 e_nobufs:
1530 return -ENOBUFS;
1531 e_inval:
1532 return -EINVAL;
1533 e_err:
1534 return err;
1535 }
1536
1537
1538 static void ip_handle_martian_source(struct net_device *dev,
1539 struct in_device *in_dev,
1540 struct sk_buff *skb,
1541 __be32 daddr,
1542 __be32 saddr)
1543 {
1544 RT_CACHE_STAT_INC(in_martian_src);
1545 #ifdef CONFIG_IP_ROUTE_VERBOSE
1546 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1547 /*
1548 * RFC1812 recommendation, if source is martian,
1549 * the only hint is MAC header.
1550 */
1551 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1552 &daddr, &saddr, dev->name);
1553 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1554 print_hex_dump(KERN_WARNING, "ll header: ",
1555 DUMP_PREFIX_OFFSET, 16, 1,
1556 skb_mac_header(skb),
1557 dev->hard_header_len, true);
1558 }
1559 }
1560 #endif
1561 }
1562
1563 static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr)
1564 {
1565 struct fnhe_hash_bucket *hash;
1566 struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1567 u32 hval = fnhe_hashfun(daddr);
1568
1569 spin_lock_bh(&fnhe_lock);
1570
1571 hash = rcu_dereference_protected(nh->nh_exceptions,
1572 lockdep_is_held(&fnhe_lock));
1573 hash += hval;
1574
1575 fnhe_p = &hash->chain;
1576 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1577 while (fnhe) {
1578 if (fnhe->fnhe_daddr == daddr) {
1579 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1580 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1581 fnhe_flush_routes(fnhe);
1582 kfree_rcu(fnhe, rcu);
1583 break;
1584 }
1585 fnhe_p = &fnhe->fnhe_next;
1586 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1587 lockdep_is_held(&fnhe_lock));
1588 }
1589
1590 spin_unlock_bh(&fnhe_lock);
1591 }
1592
1593 /* called in rcu_read_lock() section */
1594 static int __mkroute_input(struct sk_buff *skb,
1595 const struct fib_result *res,
1596 struct in_device *in_dev,
1597 __be32 daddr, __be32 saddr, u32 tos)
1598 {
1599 struct fib_nh_exception *fnhe;
1600 struct rtable *rth;
1601 int err;
1602 struct in_device *out_dev;
1603 bool do_cache;
1604 u32 itag = 0;
1605
1606 /* get a working reference to the output device */
1607 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1608 if (!out_dev) {
1609 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1610 return -EINVAL;
1611 }
1612
1613 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1614 in_dev->dev, in_dev, &itag);
1615 if (err < 0) {
1616 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1617 saddr);
1618
1619 goto cleanup;
1620 }
1621
1622 do_cache = res->fi && !itag;
1623 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1624 skb->protocol == htons(ETH_P_IP) &&
1625 (IN_DEV_SHARED_MEDIA(out_dev) ||
1626 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1627 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1628
1629 if (skb->protocol != htons(ETH_P_IP)) {
1630 /* Not IP (i.e. ARP). Do not create route, if it is
1631 * invalid for proxy arp. DNAT routes are always valid.
1632 *
1633 * Proxy arp feature have been extended to allow, ARP
1634 * replies back to the same interface, to support
1635 * Private VLAN switch technologies. See arp.c.
1636 */
1637 if (out_dev == in_dev &&
1638 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1639 err = -EINVAL;
1640 goto cleanup;
1641 }
1642 }
1643
1644 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1645 if (do_cache) {
1646 if (fnhe) {
1647 rth = rcu_dereference(fnhe->fnhe_rth_input);
1648 if (rth && rth->dst.expires &&
1649 time_after(jiffies, rth->dst.expires)) {
1650 ip_del_fnhe(&FIB_RES_NH(*res), daddr);
1651 fnhe = NULL;
1652 } else {
1653 goto rt_cache;
1654 }
1655 }
1656
1657 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1658
1659 rt_cache:
1660 if (rt_cache_valid(rth)) {
1661 skb_dst_set_noref(skb, &rth->dst);
1662 goto out;
1663 }
1664 }
1665
1666 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1667 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1668 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1669 if (!rth) {
1670 err = -ENOBUFS;
1671 goto cleanup;
1672 }
1673
1674 rth->rt_is_input = 1;
1675 if (res->table)
1676 rth->rt_table_id = res->table->tb_id;
1677 RT_CACHE_STAT_INC(in_slow_tot);
1678
1679 rth->dst.input = ip_forward;
1680
1681 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1682 if (lwtunnel_output_redirect(rth->dst.lwtstate)) {
1683 rth->dst.lwtstate->orig_output = rth->dst.output;
1684 rth->dst.output = lwtunnel_output;
1685 }
1686 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
1687 rth->dst.lwtstate->orig_input = rth->dst.input;
1688 rth->dst.input = lwtunnel_input;
1689 }
1690 skb_dst_set(skb, &rth->dst);
1691 out:
1692 err = 0;
1693 cleanup:
1694 return err;
1695 }
1696
1697 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1698
1699 /* To make ICMP packets follow the right flow, the multipath hash is
1700 * calculated from the inner IP addresses in reverse order.
1701 */
1702 static int ip_multipath_icmp_hash(struct sk_buff *skb)
1703 {
1704 const struct iphdr *outer_iph = ip_hdr(skb);
1705 struct icmphdr _icmph;
1706 const struct icmphdr *icmph;
1707 struct iphdr _inner_iph;
1708 const struct iphdr *inner_iph;
1709
1710 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1711 goto standard_hash;
1712
1713 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1714 &_icmph);
1715 if (!icmph)
1716 goto standard_hash;
1717
1718 if (icmph->type != ICMP_DEST_UNREACH &&
1719 icmph->type != ICMP_REDIRECT &&
1720 icmph->type != ICMP_TIME_EXCEEDED &&
1721 icmph->type != ICMP_PARAMETERPROB) {
1722 goto standard_hash;
1723 }
1724
1725 inner_iph = skb_header_pointer(skb,
1726 outer_iph->ihl * 4 + sizeof(_icmph),
1727 sizeof(_inner_iph), &_inner_iph);
1728 if (!inner_iph)
1729 goto standard_hash;
1730
1731 return fib_multipath_hash(inner_iph->daddr, inner_iph->saddr);
1732
1733 standard_hash:
1734 return fib_multipath_hash(outer_iph->saddr, outer_iph->daddr);
1735 }
1736
1737 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
1738
1739 static int ip_mkroute_input(struct sk_buff *skb,
1740 struct fib_result *res,
1741 const struct flowi4 *fl4,
1742 struct in_device *in_dev,
1743 __be32 daddr, __be32 saddr, u32 tos)
1744 {
1745 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1746 if (res->fi && res->fi->fib_nhs > 1) {
1747 int h;
1748
1749 if (unlikely(ip_hdr(skb)->protocol == IPPROTO_ICMP))
1750 h = ip_multipath_icmp_hash(skb);
1751 else
1752 h = fib_multipath_hash(saddr, daddr);
1753 fib_select_multipath(res, h);
1754 }
1755 #endif
1756
1757 /* create a routing cache entry */
1758 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1759 }
1760
1761 /*
1762 * NOTE. We drop all the packets that has local source
1763 * addresses, because every properly looped back packet
1764 * must have correct destination already attached by output routine.
1765 *
1766 * Such approach solves two big problems:
1767 * 1. Not simplex devices are handled properly.
1768 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1769 * called with rcu_read_lock()
1770 */
1771
1772 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1773 u8 tos, struct net_device *dev)
1774 {
1775 struct fib_result res;
1776 struct in_device *in_dev = __in_dev_get_rcu(dev);
1777 struct ip_tunnel_info *tun_info;
1778 struct flowi4 fl4;
1779 unsigned int flags = 0;
1780 u32 itag = 0;
1781 struct rtable *rth;
1782 int err = -EINVAL;
1783 struct net *net = dev_net(dev);
1784 bool do_cache;
1785
1786 /* IP on this device is disabled. */
1787
1788 if (!in_dev)
1789 goto out;
1790
1791 /* Check for the most weird martians, which can be not detected
1792 by fib_lookup.
1793 */
1794
1795 tun_info = skb_tunnel_info(skb);
1796 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
1797 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
1798 else
1799 fl4.flowi4_tun_key.tun_id = 0;
1800 skb_dst_drop(skb);
1801
1802 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1803 goto martian_source;
1804
1805 res.fi = NULL;
1806 res.table = NULL;
1807 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1808 goto brd_input;
1809
1810 /* Accept zero addresses only to limited broadcast;
1811 * I even do not know to fix it or not. Waiting for complains :-)
1812 */
1813 if (ipv4_is_zeronet(saddr))
1814 goto martian_source;
1815
1816 if (ipv4_is_zeronet(daddr))
1817 goto martian_destination;
1818
1819 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1820 * and call it once if daddr or/and saddr are loopback addresses
1821 */
1822 if (ipv4_is_loopback(daddr)) {
1823 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1824 goto martian_destination;
1825 } else if (ipv4_is_loopback(saddr)) {
1826 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1827 goto martian_source;
1828 }
1829
1830 /*
1831 * Now we are ready to route packet.
1832 */
1833 fl4.flowi4_oif = 0;
1834 fl4.flowi4_iif = dev->ifindex;
1835 fl4.flowi4_mark = skb->mark;
1836 fl4.flowi4_tos = tos;
1837 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1838 fl4.flowi4_flags = 0;
1839 fl4.daddr = daddr;
1840 fl4.saddr = saddr;
1841 err = fib_lookup(net, &fl4, &res, 0);
1842 if (err != 0) {
1843 if (!IN_DEV_FORWARD(in_dev))
1844 err = -EHOSTUNREACH;
1845 goto no_route;
1846 }
1847
1848 if (res.type == RTN_BROADCAST)
1849 goto brd_input;
1850
1851 if (res.type == RTN_LOCAL) {
1852 err = fib_validate_source(skb, saddr, daddr, tos,
1853 0, dev, in_dev, &itag);
1854 if (err < 0)
1855 goto martian_source;
1856 goto local_input;
1857 }
1858
1859 if (!IN_DEV_FORWARD(in_dev)) {
1860 err = -EHOSTUNREACH;
1861 goto no_route;
1862 }
1863 if (res.type != RTN_UNICAST)
1864 goto martian_destination;
1865
1866 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1867 out: return err;
1868
1869 brd_input:
1870 if (skb->protocol != htons(ETH_P_IP))
1871 goto e_inval;
1872
1873 if (!ipv4_is_zeronet(saddr)) {
1874 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1875 in_dev, &itag);
1876 if (err < 0)
1877 goto martian_source;
1878 }
1879 flags |= RTCF_BROADCAST;
1880 res.type = RTN_BROADCAST;
1881 RT_CACHE_STAT_INC(in_brd);
1882
1883 local_input:
1884 do_cache = false;
1885 if (res.fi) {
1886 if (!itag) {
1887 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1888 if (rt_cache_valid(rth)) {
1889 skb_dst_set_noref(skb, &rth->dst);
1890 err = 0;
1891 goto out;
1892 }
1893 do_cache = true;
1894 }
1895 }
1896
1897 rth = rt_dst_alloc(net->loopback_dev, flags | RTCF_LOCAL, res.type,
1898 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1899 if (!rth)
1900 goto e_nobufs;
1901
1902 rth->dst.output= ip_rt_bug;
1903 #ifdef CONFIG_IP_ROUTE_CLASSID
1904 rth->dst.tclassid = itag;
1905 #endif
1906 rth->rt_is_input = 1;
1907 if (res.table)
1908 rth->rt_table_id = res.table->tb_id;
1909
1910 RT_CACHE_STAT_INC(in_slow_tot);
1911 if (res.type == RTN_UNREACHABLE) {
1912 rth->dst.input= ip_error;
1913 rth->dst.error= -err;
1914 rth->rt_flags &= ~RTCF_LOCAL;
1915 }
1916 if (do_cache) {
1917 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1918 rth->dst.flags |= DST_NOCACHE;
1919 rt_add_uncached_list(rth);
1920 }
1921 }
1922 skb_dst_set(skb, &rth->dst);
1923 err = 0;
1924 goto out;
1925
1926 no_route:
1927 RT_CACHE_STAT_INC(in_no_route);
1928 res.type = RTN_UNREACHABLE;
1929 res.fi = NULL;
1930 res.table = NULL;
1931 goto local_input;
1932
1933 /*
1934 * Do not cache martian addresses: they should be logged (RFC1812)
1935 */
1936 martian_destination:
1937 RT_CACHE_STAT_INC(in_martian_dst);
1938 #ifdef CONFIG_IP_ROUTE_VERBOSE
1939 if (IN_DEV_LOG_MARTIANS(in_dev))
1940 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1941 &daddr, &saddr, dev->name);
1942 #endif
1943
1944 e_inval:
1945 err = -EINVAL;
1946 goto out;
1947
1948 e_nobufs:
1949 err = -ENOBUFS;
1950 goto out;
1951
1952 martian_source:
1953 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1954 goto out;
1955 }
1956
1957 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1958 u8 tos, struct net_device *dev)
1959 {
1960 int res;
1961
1962 rcu_read_lock();
1963
1964 /* Multicast recognition logic is moved from route cache to here.
1965 The problem was that too many Ethernet cards have broken/missing
1966 hardware multicast filters :-( As result the host on multicasting
1967 network acquires a lot of useless route cache entries, sort of
1968 SDR messages from all the world. Now we try to get rid of them.
1969 Really, provided software IP multicast filter is organized
1970 reasonably (at least, hashed), it does not result in a slowdown
1971 comparing with route cache reject entries.
1972 Note, that multicast routers are not affected, because
1973 route cache entry is created eventually.
1974 */
1975 if (ipv4_is_multicast(daddr)) {
1976 struct in_device *in_dev = __in_dev_get_rcu(dev);
1977
1978 if (in_dev) {
1979 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1980 ip_hdr(skb)->protocol);
1981 if (our
1982 #ifdef CONFIG_IP_MROUTE
1983 ||
1984 (!ipv4_is_local_multicast(daddr) &&
1985 IN_DEV_MFORWARD(in_dev))
1986 #endif
1987 ) {
1988 int res = ip_route_input_mc(skb, daddr, saddr,
1989 tos, dev, our);
1990 rcu_read_unlock();
1991 return res;
1992 }
1993 }
1994 rcu_read_unlock();
1995 return -EINVAL;
1996 }
1997 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1998 rcu_read_unlock();
1999 return res;
2000 }
2001 EXPORT_SYMBOL(ip_route_input_noref);
2002
2003 /* called with rcu_read_lock() */
2004 static struct rtable *__mkroute_output(const struct fib_result *res,
2005 const struct flowi4 *fl4, int orig_oif,
2006 struct net_device *dev_out,
2007 unsigned int flags)
2008 {
2009 struct fib_info *fi = res->fi;
2010 struct fib_nh_exception *fnhe;
2011 struct in_device *in_dev;
2012 u16 type = res->type;
2013 struct rtable *rth;
2014 bool do_cache;
2015
2016 in_dev = __in_dev_get_rcu(dev_out);
2017 if (!in_dev)
2018 return ERR_PTR(-EINVAL);
2019
2020 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2021 if (ipv4_is_loopback(fl4->saddr) &&
2022 !(dev_out->flags & IFF_LOOPBACK) &&
2023 !netif_is_l3_master(dev_out))
2024 return ERR_PTR(-EINVAL);
2025
2026 if (ipv4_is_lbcast(fl4->daddr))
2027 type = RTN_BROADCAST;
2028 else if (ipv4_is_multicast(fl4->daddr))
2029 type = RTN_MULTICAST;
2030 else if (ipv4_is_zeronet(fl4->daddr))
2031 return ERR_PTR(-EINVAL);
2032
2033 if (dev_out->flags & IFF_LOOPBACK)
2034 flags |= RTCF_LOCAL;
2035
2036 do_cache = true;
2037 if (type == RTN_BROADCAST) {
2038 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2039 fi = NULL;
2040 } else if (type == RTN_MULTICAST) {
2041 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2042 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2043 fl4->flowi4_proto))
2044 flags &= ~RTCF_LOCAL;
2045 else
2046 do_cache = false;
2047 /* If multicast route do not exist use
2048 * default one, but do not gateway in this case.
2049 * Yes, it is hack.
2050 */
2051 if (fi && res->prefixlen < 4)
2052 fi = NULL;
2053 } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2054 (orig_oif != dev_out->ifindex)) {
2055 /* For local routes that require a particular output interface
2056 * we do not want to cache the result. Caching the result
2057 * causes incorrect behaviour when there are multiple source
2058 * addresses on the interface, the end result being that if the
2059 * intended recipient is waiting on that interface for the
2060 * packet he won't receive it because it will be delivered on
2061 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2062 * be set to the loopback interface as well.
2063 */
2064 fi = NULL;
2065 }
2066
2067 fnhe = NULL;
2068 do_cache &= fi != NULL;
2069 if (do_cache) {
2070 struct rtable __rcu **prth;
2071 struct fib_nh *nh = &FIB_RES_NH(*res);
2072
2073 fnhe = find_exception(nh, fl4->daddr);
2074 if (fnhe) {
2075 prth = &fnhe->fnhe_rth_output;
2076 rth = rcu_dereference(*prth);
2077 if (rth && rth->dst.expires &&
2078 time_after(jiffies, rth->dst.expires)) {
2079 ip_del_fnhe(nh, fl4->daddr);
2080 fnhe = NULL;
2081 } else {
2082 goto rt_cache;
2083 }
2084 }
2085
2086 if (unlikely(fl4->flowi4_flags &
2087 FLOWI_FLAG_KNOWN_NH &&
2088 !(nh->nh_gw &&
2089 nh->nh_scope == RT_SCOPE_LINK))) {
2090 do_cache = false;
2091 goto add;
2092 }
2093 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
2094 rth = rcu_dereference(*prth);
2095
2096 rt_cache:
2097 if (rt_cache_valid(rth)) {
2098 dst_hold(&rth->dst);
2099 return rth;
2100 }
2101 }
2102
2103 add:
2104 rth = rt_dst_alloc(dev_out, flags, type,
2105 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2106 IN_DEV_CONF_GET(in_dev, NOXFRM),
2107 do_cache);
2108 if (!rth)
2109 return ERR_PTR(-ENOBUFS);
2110
2111 rth->rt_iif = orig_oif ? : 0;
2112 if (res->table)
2113 rth->rt_table_id = res->table->tb_id;
2114
2115 RT_CACHE_STAT_INC(out_slow_tot);
2116
2117 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2118 if (flags & RTCF_LOCAL &&
2119 !(dev_out->flags & IFF_LOOPBACK)) {
2120 rth->dst.output = ip_mc_output;
2121 RT_CACHE_STAT_INC(out_slow_mc);
2122 }
2123 #ifdef CONFIG_IP_MROUTE
2124 if (type == RTN_MULTICAST) {
2125 if (IN_DEV_MFORWARD(in_dev) &&
2126 !ipv4_is_local_multicast(fl4->daddr)) {
2127 rth->dst.input = ip_mr_input;
2128 rth->dst.output = ip_mc_output;
2129 }
2130 }
2131 #endif
2132 }
2133
2134 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
2135 if (lwtunnel_output_redirect(rth->dst.lwtstate))
2136 rth->dst.output = lwtunnel_output;
2137
2138 return rth;
2139 }
2140
2141 /*
2142 * Major route resolver routine.
2143 */
2144
2145 struct rtable *__ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2146 int mp_hash)
2147 {
2148 struct net_device *dev_out = NULL;
2149 __u8 tos = RT_FL_TOS(fl4);
2150 unsigned int flags = 0;
2151 struct fib_result res;
2152 struct rtable *rth;
2153 int orig_oif;
2154 int err = -ENETUNREACH;
2155
2156 res.tclassid = 0;
2157 res.fi = NULL;
2158 res.table = NULL;
2159
2160 orig_oif = fl4->flowi4_oif;
2161
2162 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2163 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2164 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2165 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2166
2167 rcu_read_lock();
2168 if (fl4->saddr) {
2169 rth = ERR_PTR(-EINVAL);
2170 if (ipv4_is_multicast(fl4->saddr) ||
2171 ipv4_is_lbcast(fl4->saddr) ||
2172 ipv4_is_zeronet(fl4->saddr))
2173 goto out;
2174
2175 /* I removed check for oif == dev_out->oif here.
2176 It was wrong for two reasons:
2177 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2178 is assigned to multiple interfaces.
2179 2. Moreover, we are allowed to send packets with saddr
2180 of another iface. --ANK
2181 */
2182
2183 if (fl4->flowi4_oif == 0 &&
2184 (ipv4_is_multicast(fl4->daddr) ||
2185 ipv4_is_lbcast(fl4->daddr))) {
2186 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2187 dev_out = __ip_dev_find(net, fl4->saddr, false);
2188 if (!dev_out)
2189 goto out;
2190
2191 /* Special hack: user can direct multicasts
2192 and limited broadcast via necessary interface
2193 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2194 This hack is not just for fun, it allows
2195 vic,vat and friends to work.
2196 They bind socket to loopback, set ttl to zero
2197 and expect that it will work.
2198 From the viewpoint of routing cache they are broken,
2199 because we are not allowed to build multicast path
2200 with loopback source addr (look, routing cache
2201 cannot know, that ttl is zero, so that packet
2202 will not leave this host and route is valid).
2203 Luckily, this hack is good workaround.
2204 */
2205
2206 fl4->flowi4_oif = dev_out->ifindex;
2207 goto make_route;
2208 }
2209
2210 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2211 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2212 if (!__ip_dev_find(net, fl4->saddr, false))
2213 goto out;
2214 }
2215 }
2216
2217
2218 if (fl4->flowi4_oif) {
2219 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2220 rth = ERR_PTR(-ENODEV);
2221 if (!dev_out)
2222 goto out;
2223
2224 /* RACE: Check return value of inet_select_addr instead. */
2225 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2226 rth = ERR_PTR(-ENETUNREACH);
2227 goto out;
2228 }
2229 if (ipv4_is_local_multicast(fl4->daddr) ||
2230 ipv4_is_lbcast(fl4->daddr) ||
2231 fl4->flowi4_proto == IPPROTO_IGMP) {
2232 if (!fl4->saddr)
2233 fl4->saddr = inet_select_addr(dev_out, 0,
2234 RT_SCOPE_LINK);
2235 goto make_route;
2236 }
2237 if (!fl4->saddr) {
2238 if (ipv4_is_multicast(fl4->daddr))
2239 fl4->saddr = inet_select_addr(dev_out, 0,
2240 fl4->flowi4_scope);
2241 else if (!fl4->daddr)
2242 fl4->saddr = inet_select_addr(dev_out, 0,
2243 RT_SCOPE_HOST);
2244 }
2245 }
2246
2247 if (!fl4->daddr) {
2248 fl4->daddr = fl4->saddr;
2249 if (!fl4->daddr)
2250 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2251 dev_out = net->loopback_dev;
2252 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2253 res.type = RTN_LOCAL;
2254 flags |= RTCF_LOCAL;
2255 goto make_route;
2256 }
2257
2258 err = fib_lookup(net, fl4, &res, 0);
2259 if (err) {
2260 res.fi = NULL;
2261 res.table = NULL;
2262 if (fl4->flowi4_oif) {
2263 /* Apparently, routing tables are wrong. Assume,
2264 that the destination is on link.
2265
2266 WHY? DW.
2267 Because we are allowed to send to iface
2268 even if it has NO routes and NO assigned
2269 addresses. When oif is specified, routing
2270 tables are looked up with only one purpose:
2271 to catch if destination is gatewayed, rather than
2272 direct. Moreover, if MSG_DONTROUTE is set,
2273 we send packet, ignoring both routing tables
2274 and ifaddr state. --ANK
2275
2276
2277 We could make it even if oif is unknown,
2278 likely IPv6, but we do not.
2279 */
2280
2281 if (fl4->saddr == 0)
2282 fl4->saddr = inet_select_addr(dev_out, 0,
2283 RT_SCOPE_LINK);
2284 res.type = RTN_UNICAST;
2285 goto make_route;
2286 }
2287 rth = ERR_PTR(err);
2288 goto out;
2289 }
2290
2291 if (res.type == RTN_LOCAL) {
2292 if (!fl4->saddr) {
2293 if (res.fi->fib_prefsrc)
2294 fl4->saddr = res.fi->fib_prefsrc;
2295 else
2296 fl4->saddr = fl4->daddr;
2297 }
2298
2299 /* L3 master device is the loopback for that domain */
2300 dev_out = l3mdev_master_dev_rcu(dev_out) ? : net->loopback_dev;
2301 fl4->flowi4_oif = dev_out->ifindex;
2302 flags |= RTCF_LOCAL;
2303 goto make_route;
2304 }
2305
2306 fib_select_path(net, &res, fl4, mp_hash);
2307
2308 dev_out = FIB_RES_DEV(res);
2309 fl4->flowi4_oif = dev_out->ifindex;
2310
2311
2312 make_route:
2313 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2314
2315 out:
2316 rcu_read_unlock();
2317 return rth;
2318 }
2319 EXPORT_SYMBOL_GPL(__ip_route_output_key_hash);
2320
2321 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2322 {
2323 return NULL;
2324 }
2325
2326 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2327 {
2328 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2329
2330 return mtu ? : dst->dev->mtu;
2331 }
2332
2333 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2334 struct sk_buff *skb, u32 mtu)
2335 {
2336 }
2337
2338 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2339 struct sk_buff *skb)
2340 {
2341 }
2342
2343 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2344 unsigned long old)
2345 {
2346 return NULL;
2347 }
2348
2349 static struct dst_ops ipv4_dst_blackhole_ops = {
2350 .family = AF_INET,
2351 .check = ipv4_blackhole_dst_check,
2352 .mtu = ipv4_blackhole_mtu,
2353 .default_advmss = ipv4_default_advmss,
2354 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2355 .redirect = ipv4_rt_blackhole_redirect,
2356 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2357 .neigh_lookup = ipv4_neigh_lookup,
2358 };
2359
2360 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2361 {
2362 struct rtable *ort = (struct rtable *) dst_orig;
2363 struct rtable *rt;
2364
2365 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2366 if (rt) {
2367 struct dst_entry *new = &rt->dst;
2368
2369 new->__use = 1;
2370 new->input = dst_discard;
2371 new->output = dst_discard_out;
2372
2373 new->dev = ort->dst.dev;
2374 if (new->dev)
2375 dev_hold(new->dev);
2376
2377 rt->rt_is_input = ort->rt_is_input;
2378 rt->rt_iif = ort->rt_iif;
2379 rt->rt_pmtu = ort->rt_pmtu;
2380
2381 rt->rt_genid = rt_genid_ipv4(net);
2382 rt->rt_flags = ort->rt_flags;
2383 rt->rt_type = ort->rt_type;
2384 rt->rt_gateway = ort->rt_gateway;
2385 rt->rt_uses_gateway = ort->rt_uses_gateway;
2386
2387 INIT_LIST_HEAD(&rt->rt_uncached);
2388 dst_free(new);
2389 }
2390
2391 dst_release(dst_orig);
2392
2393 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2394 }
2395
2396 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2397 const struct sock *sk)
2398 {
2399 struct rtable *rt = __ip_route_output_key(net, flp4);
2400
2401 if (IS_ERR(rt))
2402 return rt;
2403
2404 if (flp4->flowi4_proto)
2405 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2406 flowi4_to_flowi(flp4),
2407 sk, 0);
2408
2409 return rt;
2410 }
2411 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2412
2413 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, u32 table_id,
2414 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2415 u32 seq, int event, int nowait, unsigned int flags)
2416 {
2417 struct rtable *rt = skb_rtable(skb);
2418 struct rtmsg *r;
2419 struct nlmsghdr *nlh;
2420 unsigned long expires = 0;
2421 u32 error;
2422 u32 metrics[RTAX_MAX];
2423
2424 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2425 if (!nlh)
2426 return -EMSGSIZE;
2427
2428 r = nlmsg_data(nlh);
2429 r->rtm_family = AF_INET;
2430 r->rtm_dst_len = 32;
2431 r->rtm_src_len = 0;
2432 r->rtm_tos = fl4->flowi4_tos;
2433 r->rtm_table = table_id;
2434 if (nla_put_u32(skb, RTA_TABLE, table_id))
2435 goto nla_put_failure;
2436 r->rtm_type = rt->rt_type;
2437 r->rtm_scope = RT_SCOPE_UNIVERSE;
2438 r->rtm_protocol = RTPROT_UNSPEC;
2439 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2440 if (rt->rt_flags & RTCF_NOTIFY)
2441 r->rtm_flags |= RTM_F_NOTIFY;
2442 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2443 r->rtm_flags |= RTCF_DOREDIRECT;
2444
2445 if (nla_put_in_addr(skb, RTA_DST, dst))
2446 goto nla_put_failure;
2447 if (src) {
2448 r->rtm_src_len = 32;
2449 if (nla_put_in_addr(skb, RTA_SRC, src))
2450 goto nla_put_failure;
2451 }
2452 if (rt->dst.dev &&
2453 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2454 goto nla_put_failure;
2455 #ifdef CONFIG_IP_ROUTE_CLASSID
2456 if (rt->dst.tclassid &&
2457 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2458 goto nla_put_failure;
2459 #endif
2460 if (!rt_is_input_route(rt) &&
2461 fl4->saddr != src) {
2462 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2463 goto nla_put_failure;
2464 }
2465 if (rt->rt_uses_gateway &&
2466 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2467 goto nla_put_failure;
2468
2469 expires = rt->dst.expires;
2470 if (expires) {
2471 unsigned long now = jiffies;
2472
2473 if (time_before(now, expires))
2474 expires -= now;
2475 else
2476 expires = 0;
2477 }
2478
2479 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2480 if (rt->rt_pmtu && expires)
2481 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2482 if (rtnetlink_put_metrics(skb, metrics) < 0)
2483 goto nla_put_failure;
2484
2485 if (fl4->flowi4_mark &&
2486 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2487 goto nla_put_failure;
2488
2489 error = rt->dst.error;
2490
2491 if (rt_is_input_route(rt)) {
2492 #ifdef CONFIG_IP_MROUTE
2493 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2494 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2495 int err = ipmr_get_route(net, skb,
2496 fl4->saddr, fl4->daddr,
2497 r, nowait);
2498 if (err <= 0) {
2499 if (!nowait) {
2500 if (err == 0)
2501 return 0;
2502 goto nla_put_failure;
2503 } else {
2504 if (err == -EMSGSIZE)
2505 goto nla_put_failure;
2506 error = err;
2507 }
2508 }
2509 } else
2510 #endif
2511 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2512 goto nla_put_failure;
2513 }
2514
2515 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2516 goto nla_put_failure;
2517
2518 nlmsg_end(skb, nlh);
2519 return 0;
2520
2521 nla_put_failure:
2522 nlmsg_cancel(skb, nlh);
2523 return -EMSGSIZE;
2524 }
2525
2526 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2527 {
2528 struct net *net = sock_net(in_skb->sk);
2529 struct rtmsg *rtm;
2530 struct nlattr *tb[RTA_MAX+1];
2531 struct rtable *rt = NULL;
2532 struct flowi4 fl4;
2533 __be32 dst = 0;
2534 __be32 src = 0;
2535 u32 iif;
2536 int err;
2537 int mark;
2538 struct sk_buff *skb;
2539 u32 table_id = RT_TABLE_MAIN;
2540
2541 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2542 if (err < 0)
2543 goto errout;
2544
2545 rtm = nlmsg_data(nlh);
2546
2547 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2548 if (!skb) {
2549 err = -ENOBUFS;
2550 goto errout;
2551 }
2552
2553 /* Reserve room for dummy headers, this skb can pass
2554 through good chunk of routing engine.
2555 */
2556 skb_reset_mac_header(skb);
2557 skb_reset_network_header(skb);
2558
2559 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2560 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2561 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2562
2563 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2564 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2565 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2566 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2567
2568 memset(&fl4, 0, sizeof(fl4));
2569 fl4.daddr = dst;
2570 fl4.saddr = src;
2571 fl4.flowi4_tos = rtm->rtm_tos;
2572 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2573 fl4.flowi4_mark = mark;
2574
2575 if (iif) {
2576 struct net_device *dev;
2577
2578 dev = __dev_get_by_index(net, iif);
2579 if (!dev) {
2580 err = -ENODEV;
2581 goto errout_free;
2582 }
2583
2584 skb->protocol = htons(ETH_P_IP);
2585 skb->dev = dev;
2586 skb->mark = mark;
2587 local_bh_disable();
2588 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2589 local_bh_enable();
2590
2591 rt = skb_rtable(skb);
2592 if (err == 0 && rt->dst.error)
2593 err = -rt->dst.error;
2594 } else {
2595 rt = ip_route_output_key(net, &fl4);
2596
2597 err = 0;
2598 if (IS_ERR(rt))
2599 err = PTR_ERR(rt);
2600 }
2601
2602 if (err)
2603 goto errout_free;
2604
2605 skb_dst_set(skb, &rt->dst);
2606 if (rtm->rtm_flags & RTM_F_NOTIFY)
2607 rt->rt_flags |= RTCF_NOTIFY;
2608
2609 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
2610 table_id = rt->rt_table_id;
2611
2612 err = rt_fill_info(net, dst, src, table_id, &fl4, skb,
2613 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2614 RTM_NEWROUTE, 0, 0);
2615 if (err < 0)
2616 goto errout_free;
2617
2618 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2619 errout:
2620 return err;
2621
2622 errout_free:
2623 kfree_skb(skb);
2624 goto errout;
2625 }
2626
2627 void ip_rt_multicast_event(struct in_device *in_dev)
2628 {
2629 rt_cache_flush(dev_net(in_dev->dev));
2630 }
2631
2632 #ifdef CONFIG_SYSCTL
2633 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2634 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2635 static int ip_rt_gc_elasticity __read_mostly = 8;
2636
2637 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2638 void __user *buffer,
2639 size_t *lenp, loff_t *ppos)
2640 {
2641 struct net *net = (struct net *)__ctl->extra1;
2642
2643 if (write) {
2644 rt_cache_flush(net);
2645 fnhe_genid_bump(net);
2646 return 0;
2647 }
2648
2649 return -EINVAL;
2650 }
2651
2652 static struct ctl_table ipv4_route_table[] = {
2653 {
2654 .procname = "gc_thresh",
2655 .data = &ipv4_dst_ops.gc_thresh,
2656 .maxlen = sizeof(int),
2657 .mode = 0644,
2658 .proc_handler = proc_dointvec,
2659 },
2660 {
2661 .procname = "max_size",
2662 .data = &ip_rt_max_size,
2663 .maxlen = sizeof(int),
2664 .mode = 0644,
2665 .proc_handler = proc_dointvec,
2666 },
2667 {
2668 /* Deprecated. Use gc_min_interval_ms */
2669
2670 .procname = "gc_min_interval",
2671 .data = &ip_rt_gc_min_interval,
2672 .maxlen = sizeof(int),
2673 .mode = 0644,
2674 .proc_handler = proc_dointvec_jiffies,
2675 },
2676 {
2677 .procname = "gc_min_interval_ms",
2678 .data = &ip_rt_gc_min_interval,
2679 .maxlen = sizeof(int),
2680 .mode = 0644,
2681 .proc_handler = proc_dointvec_ms_jiffies,
2682 },
2683 {
2684 .procname = "gc_timeout",
2685 .data = &ip_rt_gc_timeout,
2686 .maxlen = sizeof(int),
2687 .mode = 0644,
2688 .proc_handler = proc_dointvec_jiffies,
2689 },
2690 {
2691 .procname = "gc_interval",
2692 .data = &ip_rt_gc_interval,
2693 .maxlen = sizeof(int),
2694 .mode = 0644,
2695 .proc_handler = proc_dointvec_jiffies,
2696 },
2697 {
2698 .procname = "redirect_load",
2699 .data = &ip_rt_redirect_load,
2700 .maxlen = sizeof(int),
2701 .mode = 0644,
2702 .proc_handler = proc_dointvec,
2703 },
2704 {
2705 .procname = "redirect_number",
2706 .data = &ip_rt_redirect_number,
2707 .maxlen = sizeof(int),
2708 .mode = 0644,
2709 .proc_handler = proc_dointvec,
2710 },
2711 {
2712 .procname = "redirect_silence",
2713 .data = &ip_rt_redirect_silence,
2714 .maxlen = sizeof(int),
2715 .mode = 0644,
2716 .proc_handler = proc_dointvec,
2717 },
2718 {
2719 .procname = "error_cost",
2720 .data = &ip_rt_error_cost,
2721 .maxlen = sizeof(int),
2722 .mode = 0644,
2723 .proc_handler = proc_dointvec,
2724 },
2725 {
2726 .procname = "error_burst",
2727 .data = &ip_rt_error_burst,
2728 .maxlen = sizeof(int),
2729 .mode = 0644,
2730 .proc_handler = proc_dointvec,
2731 },
2732 {
2733 .procname = "gc_elasticity",
2734 .data = &ip_rt_gc_elasticity,
2735 .maxlen = sizeof(int),
2736 .mode = 0644,
2737 .proc_handler = proc_dointvec,
2738 },
2739 {
2740 .procname = "mtu_expires",
2741 .data = &ip_rt_mtu_expires,
2742 .maxlen = sizeof(int),
2743 .mode = 0644,
2744 .proc_handler = proc_dointvec_jiffies,
2745 },
2746 {
2747 .procname = "min_pmtu",
2748 .data = &ip_rt_min_pmtu,
2749 .maxlen = sizeof(int),
2750 .mode = 0644,
2751 .proc_handler = proc_dointvec,
2752 },
2753 {
2754 .procname = "min_adv_mss",
2755 .data = &ip_rt_min_advmss,
2756 .maxlen = sizeof(int),
2757 .mode = 0644,
2758 .proc_handler = proc_dointvec,
2759 },
2760 { }
2761 };
2762
2763 static struct ctl_table ipv4_route_flush_table[] = {
2764 {
2765 .procname = "flush",
2766 .maxlen = sizeof(int),
2767 .mode = 0200,
2768 .proc_handler = ipv4_sysctl_rtcache_flush,
2769 },
2770 { },
2771 };
2772
2773 static __net_init int sysctl_route_net_init(struct net *net)
2774 {
2775 struct ctl_table *tbl;
2776
2777 tbl = ipv4_route_flush_table;
2778 if (!net_eq(net, &init_net)) {
2779 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2780 if (!tbl)
2781 goto err_dup;
2782
2783 /* Don't export sysctls to unprivileged users */
2784 if (net->user_ns != &init_user_ns)
2785 tbl[0].procname = NULL;
2786 }
2787 tbl[0].extra1 = net;
2788
2789 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2790 if (!net->ipv4.route_hdr)
2791 goto err_reg;
2792 return 0;
2793
2794 err_reg:
2795 if (tbl != ipv4_route_flush_table)
2796 kfree(tbl);
2797 err_dup:
2798 return -ENOMEM;
2799 }
2800
2801 static __net_exit void sysctl_route_net_exit(struct net *net)
2802 {
2803 struct ctl_table *tbl;
2804
2805 tbl = net->ipv4.route_hdr->ctl_table_arg;
2806 unregister_net_sysctl_table(net->ipv4.route_hdr);
2807 BUG_ON(tbl == ipv4_route_flush_table);
2808 kfree(tbl);
2809 }
2810
2811 static __net_initdata struct pernet_operations sysctl_route_ops = {
2812 .init = sysctl_route_net_init,
2813 .exit = sysctl_route_net_exit,
2814 };
2815 #endif
2816
2817 static __net_init int rt_genid_init(struct net *net)
2818 {
2819 atomic_set(&net->ipv4.rt_genid, 0);
2820 atomic_set(&net->fnhe_genid, 0);
2821 get_random_bytes(&net->ipv4.dev_addr_genid,
2822 sizeof(net->ipv4.dev_addr_genid));
2823 return 0;
2824 }
2825
2826 static __net_initdata struct pernet_operations rt_genid_ops = {
2827 .init = rt_genid_init,
2828 };
2829
2830 static int __net_init ipv4_inetpeer_init(struct net *net)
2831 {
2832 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2833
2834 if (!bp)
2835 return -ENOMEM;
2836 inet_peer_base_init(bp);
2837 net->ipv4.peers = bp;
2838 return 0;
2839 }
2840
2841 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2842 {
2843 struct inet_peer_base *bp = net->ipv4.peers;
2844
2845 net->ipv4.peers = NULL;
2846 inetpeer_invalidate_tree(bp);
2847 kfree(bp);
2848 }
2849
2850 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2851 .init = ipv4_inetpeer_init,
2852 .exit = ipv4_inetpeer_exit,
2853 };
2854
2855 #ifdef CONFIG_IP_ROUTE_CLASSID
2856 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2857 #endif /* CONFIG_IP_ROUTE_CLASSID */
2858
2859 int __init ip_rt_init(void)
2860 {
2861 int rc = 0;
2862 int cpu;
2863
2864 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2865 if (!ip_idents)
2866 panic("IP: failed to allocate ip_idents\n");
2867
2868 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2869
2870 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
2871 if (!ip_tstamps)
2872 panic("IP: failed to allocate ip_tstamps\n");
2873
2874 for_each_possible_cpu(cpu) {
2875 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
2876
2877 INIT_LIST_HEAD(&ul->head);
2878 spin_lock_init(&ul->lock);
2879 }
2880 #ifdef CONFIG_IP_ROUTE_CLASSID
2881 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2882 if (!ip_rt_acct)
2883 panic("IP: failed to allocate ip_rt_acct\n");
2884 #endif
2885
2886 ipv4_dst_ops.kmem_cachep =
2887 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2888 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2889
2890 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2891
2892 if (dst_entries_init(&ipv4_dst_ops) < 0)
2893 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2894
2895 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2896 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2897
2898 ipv4_dst_ops.gc_thresh = ~0;
2899 ip_rt_max_size = INT_MAX;
2900
2901 devinet_init();
2902 ip_fib_init();
2903
2904 if (ip_rt_proc_init())
2905 pr_err("Unable to create route proc files\n");
2906 #ifdef CONFIG_XFRM
2907 xfrm_init();
2908 xfrm4_init();
2909 #endif
2910 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2911
2912 #ifdef CONFIG_SYSCTL
2913 register_pernet_subsys(&sysctl_route_ops);
2914 #endif
2915 register_pernet_subsys(&rt_genid_ops);
2916 register_pernet_subsys(&ipv4_inetpeer_ops);
2917 return rc;
2918 }
2919
2920 #ifdef CONFIG_SYSCTL
2921 /*
2922 * We really need to sanitize the damn ipv4 init order, then all
2923 * this nonsense will go away.
2924 */
2925 void __init ip_static_sysctl_init(void)
2926 {
2927 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2928 }
2929 #endif
Linux kernel - Deliverables
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