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Merge tag 'drm-intel-fixes-2015-06-05' of git://anongit.freedesktop.org/drm-intel...
[deliverable/linux.git] / net / ipv4 / route.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65 #define pr_fmt(fmt) "IPv4: " fmt
66
67 #include <linux/module.h>
68 #include <asm/uaccess.h>
69 #include <linux/bitops.h>
70 #include <linux/types.h>
71 #include <linux/kernel.h>
72 #include <linux/mm.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
77 #include <linux/in.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/skbuff.h>
83 #include <linux/inetdevice.h>
84 #include <linux/igmp.h>
85 #include <linux/pkt_sched.h>
86 #include <linux/mroute.h>
87 #include <linux/netfilter_ipv4.h>
88 #include <linux/random.h>
89 #include <linux/rcupdate.h>
90 #include <linux/times.h>
91 #include <linux/slab.h>
92 #include <linux/jhash.h>
93 #include <net/dst.h>
94 #include <net/net_namespace.h>
95 #include <net/protocol.h>
96 #include <net/ip.h>
97 #include <net/route.h>
98 #include <net/inetpeer.h>
99 #include <net/sock.h>
100 #include <net/ip_fib.h>
101 #include <net/arp.h>
102 #include <net/tcp.h>
103 #include <net/icmp.h>
104 #include <net/xfrm.h>
105 #include <net/netevent.h>
106 #include <net/rtnetlink.h>
107 #ifdef CONFIG_SYSCTL
108 #include <linux/sysctl.h>
109 #include <linux/kmemleak.h>
110 #endif
111 #include <net/secure_seq.h>
112
113 #define RT_FL_TOS(oldflp4) \
114 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
115
116 #define RT_GC_TIMEOUT (300*HZ)
117
118 static int ip_rt_max_size;
119 static int ip_rt_redirect_number __read_mostly = 9;
120 static int ip_rt_redirect_load __read_mostly = HZ / 50;
121 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
122 static int ip_rt_error_cost __read_mostly = HZ;
123 static int ip_rt_error_burst __read_mostly = 5 * HZ;
124 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
125 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
126 static int ip_rt_min_advmss __read_mostly = 256;
127
128 /*
129 * Interface to generic destination cache.
130 */
131
132 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
133 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
134 static unsigned int ipv4_mtu(const struct dst_entry *dst);
135 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
136 static void ipv4_link_failure(struct sk_buff *skb);
137 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
138 struct sk_buff *skb, u32 mtu);
139 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
140 struct sk_buff *skb);
141 static void ipv4_dst_destroy(struct dst_entry *dst);
142
143 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
144 {
145 WARN_ON(1);
146 return NULL;
147 }
148
149 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
150 struct sk_buff *skb,
151 const void *daddr);
152
153 static struct dst_ops ipv4_dst_ops = {
154 .family = AF_INET,
155 .check = ipv4_dst_check,
156 .default_advmss = ipv4_default_advmss,
157 .mtu = ipv4_mtu,
158 .cow_metrics = ipv4_cow_metrics,
159 .destroy = ipv4_dst_destroy,
160 .negative_advice = ipv4_negative_advice,
161 .link_failure = ipv4_link_failure,
162 .update_pmtu = ip_rt_update_pmtu,
163 .redirect = ip_do_redirect,
164 .local_out = __ip_local_out,
165 .neigh_lookup = ipv4_neigh_lookup,
166 };
167
168 #define ECN_OR_COST(class) TC_PRIO_##class
169
170 const __u8 ip_tos2prio[16] = {
171 TC_PRIO_BESTEFFORT,
172 ECN_OR_COST(BESTEFFORT),
173 TC_PRIO_BESTEFFORT,
174 ECN_OR_COST(BESTEFFORT),
175 TC_PRIO_BULK,
176 ECN_OR_COST(BULK),
177 TC_PRIO_BULK,
178 ECN_OR_COST(BULK),
179 TC_PRIO_INTERACTIVE,
180 ECN_OR_COST(INTERACTIVE),
181 TC_PRIO_INTERACTIVE,
182 ECN_OR_COST(INTERACTIVE),
183 TC_PRIO_INTERACTIVE_BULK,
184 ECN_OR_COST(INTERACTIVE_BULK),
185 TC_PRIO_INTERACTIVE_BULK,
186 ECN_OR_COST(INTERACTIVE_BULK)
187 };
188 EXPORT_SYMBOL(ip_tos2prio);
189
190 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
191 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
192
193 #ifdef CONFIG_PROC_FS
194 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
195 {
196 if (*pos)
197 return NULL;
198 return SEQ_START_TOKEN;
199 }
200
201 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
202 {
203 ++*pos;
204 return NULL;
205 }
206
207 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
208 {
209 }
210
211 static int rt_cache_seq_show(struct seq_file *seq, void *v)
212 {
213 if (v == SEQ_START_TOKEN)
214 seq_printf(seq, "%-127s\n",
215 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
216 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
217 "HHUptod\tSpecDst");
218 return 0;
219 }
220
221 static const struct seq_operations rt_cache_seq_ops = {
222 .start = rt_cache_seq_start,
223 .next = rt_cache_seq_next,
224 .stop = rt_cache_seq_stop,
225 .show = rt_cache_seq_show,
226 };
227
228 static int rt_cache_seq_open(struct inode *inode, struct file *file)
229 {
230 return seq_open(file, &rt_cache_seq_ops);
231 }
232
233 static const struct file_operations rt_cache_seq_fops = {
234 .owner = THIS_MODULE,
235 .open = rt_cache_seq_open,
236 .read = seq_read,
237 .llseek = seq_lseek,
238 .release = seq_release,
239 };
240
241
242 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
243 {
244 int cpu;
245
246 if (*pos == 0)
247 return SEQ_START_TOKEN;
248
249 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
250 if (!cpu_possible(cpu))
251 continue;
252 *pos = cpu+1;
253 return &per_cpu(rt_cache_stat, cpu);
254 }
255 return NULL;
256 }
257
258 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
259 {
260 int cpu;
261
262 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
263 if (!cpu_possible(cpu))
264 continue;
265 *pos = cpu+1;
266 return &per_cpu(rt_cache_stat, cpu);
267 }
268 return NULL;
269
270 }
271
272 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
273 {
274
275 }
276
277 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
278 {
279 struct rt_cache_stat *st = v;
280
281 if (v == SEQ_START_TOKEN) {
282 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
283 return 0;
284 }
285
286 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
287 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
288 dst_entries_get_slow(&ipv4_dst_ops),
289 0, /* st->in_hit */
290 st->in_slow_tot,
291 st->in_slow_mc,
292 st->in_no_route,
293 st->in_brd,
294 st->in_martian_dst,
295 st->in_martian_src,
296
297 0, /* st->out_hit */
298 st->out_slow_tot,
299 st->out_slow_mc,
300
301 0, /* st->gc_total */
302 0, /* st->gc_ignored */
303 0, /* st->gc_goal_miss */
304 0, /* st->gc_dst_overflow */
305 0, /* st->in_hlist_search */
306 0 /* st->out_hlist_search */
307 );
308 return 0;
309 }
310
311 static const struct seq_operations rt_cpu_seq_ops = {
312 .start = rt_cpu_seq_start,
313 .next = rt_cpu_seq_next,
314 .stop = rt_cpu_seq_stop,
315 .show = rt_cpu_seq_show,
316 };
317
318
319 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
320 {
321 return seq_open(file, &rt_cpu_seq_ops);
322 }
323
324 static const struct file_operations rt_cpu_seq_fops = {
325 .owner = THIS_MODULE,
326 .open = rt_cpu_seq_open,
327 .read = seq_read,
328 .llseek = seq_lseek,
329 .release = seq_release,
330 };
331
332 #ifdef CONFIG_IP_ROUTE_CLASSID
333 static int rt_acct_proc_show(struct seq_file *m, void *v)
334 {
335 struct ip_rt_acct *dst, *src;
336 unsigned int i, j;
337
338 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
339 if (!dst)
340 return -ENOMEM;
341
342 for_each_possible_cpu(i) {
343 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
344 for (j = 0; j < 256; j++) {
345 dst[j].o_bytes += src[j].o_bytes;
346 dst[j].o_packets += src[j].o_packets;
347 dst[j].i_bytes += src[j].i_bytes;
348 dst[j].i_packets += src[j].i_packets;
349 }
350 }
351
352 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
353 kfree(dst);
354 return 0;
355 }
356
357 static int rt_acct_proc_open(struct inode *inode, struct file *file)
358 {
359 return single_open(file, rt_acct_proc_show, NULL);
360 }
361
362 static const struct file_operations rt_acct_proc_fops = {
363 .owner = THIS_MODULE,
364 .open = rt_acct_proc_open,
365 .read = seq_read,
366 .llseek = seq_lseek,
367 .release = single_release,
368 };
369 #endif
370
371 static int __net_init ip_rt_do_proc_init(struct net *net)
372 {
373 struct proc_dir_entry *pde;
374
375 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
376 &rt_cache_seq_fops);
377 if (!pde)
378 goto err1;
379
380 pde = proc_create("rt_cache", S_IRUGO,
381 net->proc_net_stat, &rt_cpu_seq_fops);
382 if (!pde)
383 goto err2;
384
385 #ifdef CONFIG_IP_ROUTE_CLASSID
386 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
387 if (!pde)
388 goto err3;
389 #endif
390 return 0;
391
392 #ifdef CONFIG_IP_ROUTE_CLASSID
393 err3:
394 remove_proc_entry("rt_cache", net->proc_net_stat);
395 #endif
396 err2:
397 remove_proc_entry("rt_cache", net->proc_net);
398 err1:
399 return -ENOMEM;
400 }
401
402 static void __net_exit ip_rt_do_proc_exit(struct net *net)
403 {
404 remove_proc_entry("rt_cache", net->proc_net_stat);
405 remove_proc_entry("rt_cache", net->proc_net);
406 #ifdef CONFIG_IP_ROUTE_CLASSID
407 remove_proc_entry("rt_acct", net->proc_net);
408 #endif
409 }
410
411 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
412 .init = ip_rt_do_proc_init,
413 .exit = ip_rt_do_proc_exit,
414 };
415
416 static int __init ip_rt_proc_init(void)
417 {
418 return register_pernet_subsys(&ip_rt_proc_ops);
419 }
420
421 #else
422 static inline int ip_rt_proc_init(void)
423 {
424 return 0;
425 }
426 #endif /* CONFIG_PROC_FS */
427
428 static inline bool rt_is_expired(const struct rtable *rth)
429 {
430 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
431 }
432
433 void rt_cache_flush(struct net *net)
434 {
435 rt_genid_bump_ipv4(net);
436 }
437
438 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
439 struct sk_buff *skb,
440 const void *daddr)
441 {
442 struct net_device *dev = dst->dev;
443 const __be32 *pkey = daddr;
444 const struct rtable *rt;
445 struct neighbour *n;
446
447 rt = (const struct rtable *) dst;
448 if (rt->rt_gateway)
449 pkey = (const __be32 *) &rt->rt_gateway;
450 else if (skb)
451 pkey = &ip_hdr(skb)->daddr;
452
453 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
454 if (n)
455 return n;
456 return neigh_create(&arp_tbl, pkey, dev);
457 }
458
459 #define IP_IDENTS_SZ 2048u
460 struct ip_ident_bucket {
461 atomic_t id;
462 u32 stamp32;
463 };
464
465 static struct ip_ident_bucket *ip_idents __read_mostly;
466
467 /* In order to protect privacy, we add a perturbation to identifiers
468 * if one generator is seldom used. This makes hard for an attacker
469 * to infer how many packets were sent between two points in time.
470 */
471 u32 ip_idents_reserve(u32 hash, int segs)
472 {
473 struct ip_ident_bucket *bucket = ip_idents + hash % IP_IDENTS_SZ;
474 u32 old = ACCESS_ONCE(bucket->stamp32);
475 u32 now = (u32)jiffies;
476 u32 delta = 0;
477
478 if (old != now && cmpxchg(&bucket->stamp32, old, now) == old)
479 delta = prandom_u32_max(now - old);
480
481 return atomic_add_return(segs + delta, &bucket->id) - segs;
482 }
483 EXPORT_SYMBOL(ip_idents_reserve);
484
485 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
486 {
487 static u32 ip_idents_hashrnd __read_mostly;
488 u32 hash, id;
489
490 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
491
492 hash = jhash_3words((__force u32)iph->daddr,
493 (__force u32)iph->saddr,
494 iph->protocol ^ net_hash_mix(net),
495 ip_idents_hashrnd);
496 id = ip_idents_reserve(hash, segs);
497 iph->id = htons(id);
498 }
499 EXPORT_SYMBOL(__ip_select_ident);
500
501 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
502 const struct iphdr *iph,
503 int oif, u8 tos,
504 u8 prot, u32 mark, int flow_flags)
505 {
506 if (sk) {
507 const struct inet_sock *inet = inet_sk(sk);
508
509 oif = sk->sk_bound_dev_if;
510 mark = sk->sk_mark;
511 tos = RT_CONN_FLAGS(sk);
512 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
513 }
514 flowi4_init_output(fl4, oif, mark, tos,
515 RT_SCOPE_UNIVERSE, prot,
516 flow_flags,
517 iph->daddr, iph->saddr, 0, 0);
518 }
519
520 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
521 const struct sock *sk)
522 {
523 const struct iphdr *iph = ip_hdr(skb);
524 int oif = skb->dev->ifindex;
525 u8 tos = RT_TOS(iph->tos);
526 u8 prot = iph->protocol;
527 u32 mark = skb->mark;
528
529 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
530 }
531
532 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
533 {
534 const struct inet_sock *inet = inet_sk(sk);
535 const struct ip_options_rcu *inet_opt;
536 __be32 daddr = inet->inet_daddr;
537
538 rcu_read_lock();
539 inet_opt = rcu_dereference(inet->inet_opt);
540 if (inet_opt && inet_opt->opt.srr)
541 daddr = inet_opt->opt.faddr;
542 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
543 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
544 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
545 inet_sk_flowi_flags(sk),
546 daddr, inet->inet_saddr, 0, 0);
547 rcu_read_unlock();
548 }
549
550 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
551 const struct sk_buff *skb)
552 {
553 if (skb)
554 build_skb_flow_key(fl4, skb, sk);
555 else
556 build_sk_flow_key(fl4, sk);
557 }
558
559 static inline void rt_free(struct rtable *rt)
560 {
561 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
562 }
563
564 static DEFINE_SPINLOCK(fnhe_lock);
565
566 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
567 {
568 struct rtable *rt;
569
570 rt = rcu_dereference(fnhe->fnhe_rth_input);
571 if (rt) {
572 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
573 rt_free(rt);
574 }
575 rt = rcu_dereference(fnhe->fnhe_rth_output);
576 if (rt) {
577 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
578 rt_free(rt);
579 }
580 }
581
582 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
583 {
584 struct fib_nh_exception *fnhe, *oldest;
585
586 oldest = rcu_dereference(hash->chain);
587 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
588 fnhe = rcu_dereference(fnhe->fnhe_next)) {
589 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
590 oldest = fnhe;
591 }
592 fnhe_flush_routes(oldest);
593 return oldest;
594 }
595
596 static inline u32 fnhe_hashfun(__be32 daddr)
597 {
598 static u32 fnhe_hashrnd __read_mostly;
599 u32 hval;
600
601 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
602 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
603 return hash_32(hval, FNHE_HASH_SHIFT);
604 }
605
606 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
607 {
608 rt->rt_pmtu = fnhe->fnhe_pmtu;
609 rt->dst.expires = fnhe->fnhe_expires;
610
611 if (fnhe->fnhe_gw) {
612 rt->rt_flags |= RTCF_REDIRECTED;
613 rt->rt_gateway = fnhe->fnhe_gw;
614 rt->rt_uses_gateway = 1;
615 }
616 }
617
618 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
619 u32 pmtu, unsigned long expires)
620 {
621 struct fnhe_hash_bucket *hash;
622 struct fib_nh_exception *fnhe;
623 struct rtable *rt;
624 unsigned int i;
625 int depth;
626 u32 hval = fnhe_hashfun(daddr);
627
628 spin_lock_bh(&fnhe_lock);
629
630 hash = rcu_dereference(nh->nh_exceptions);
631 if (!hash) {
632 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
633 if (!hash)
634 goto out_unlock;
635 rcu_assign_pointer(nh->nh_exceptions, hash);
636 }
637
638 hash += hval;
639
640 depth = 0;
641 for (fnhe = rcu_dereference(hash->chain); fnhe;
642 fnhe = rcu_dereference(fnhe->fnhe_next)) {
643 if (fnhe->fnhe_daddr == daddr)
644 break;
645 depth++;
646 }
647
648 if (fnhe) {
649 if (gw)
650 fnhe->fnhe_gw = gw;
651 if (pmtu) {
652 fnhe->fnhe_pmtu = pmtu;
653 fnhe->fnhe_expires = max(1UL, expires);
654 }
655 /* Update all cached dsts too */
656 rt = rcu_dereference(fnhe->fnhe_rth_input);
657 if (rt)
658 fill_route_from_fnhe(rt, fnhe);
659 rt = rcu_dereference(fnhe->fnhe_rth_output);
660 if (rt)
661 fill_route_from_fnhe(rt, fnhe);
662 } else {
663 if (depth > FNHE_RECLAIM_DEPTH)
664 fnhe = fnhe_oldest(hash);
665 else {
666 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
667 if (!fnhe)
668 goto out_unlock;
669
670 fnhe->fnhe_next = hash->chain;
671 rcu_assign_pointer(hash->chain, fnhe);
672 }
673 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
674 fnhe->fnhe_daddr = daddr;
675 fnhe->fnhe_gw = gw;
676 fnhe->fnhe_pmtu = pmtu;
677 fnhe->fnhe_expires = expires;
678
679 /* Exception created; mark the cached routes for the nexthop
680 * stale, so anyone caching it rechecks if this exception
681 * applies to them.
682 */
683 rt = rcu_dereference(nh->nh_rth_input);
684 if (rt)
685 rt->dst.obsolete = DST_OBSOLETE_KILL;
686
687 for_each_possible_cpu(i) {
688 struct rtable __rcu **prt;
689 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
690 rt = rcu_dereference(*prt);
691 if (rt)
692 rt->dst.obsolete = DST_OBSOLETE_KILL;
693 }
694 }
695
696 fnhe->fnhe_stamp = jiffies;
697
698 out_unlock:
699 spin_unlock_bh(&fnhe_lock);
700 }
701
702 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
703 bool kill_route)
704 {
705 __be32 new_gw = icmp_hdr(skb)->un.gateway;
706 __be32 old_gw = ip_hdr(skb)->saddr;
707 struct net_device *dev = skb->dev;
708 struct in_device *in_dev;
709 struct fib_result res;
710 struct neighbour *n;
711 struct net *net;
712
713 switch (icmp_hdr(skb)->code & 7) {
714 case ICMP_REDIR_NET:
715 case ICMP_REDIR_NETTOS:
716 case ICMP_REDIR_HOST:
717 case ICMP_REDIR_HOSTTOS:
718 break;
719
720 default:
721 return;
722 }
723
724 if (rt->rt_gateway != old_gw)
725 return;
726
727 in_dev = __in_dev_get_rcu(dev);
728 if (!in_dev)
729 return;
730
731 net = dev_net(dev);
732 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
733 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
734 ipv4_is_zeronet(new_gw))
735 goto reject_redirect;
736
737 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
738 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
739 goto reject_redirect;
740 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
741 goto reject_redirect;
742 } else {
743 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
744 goto reject_redirect;
745 }
746
747 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
748 if (!IS_ERR(n)) {
749 if (!(n->nud_state & NUD_VALID)) {
750 neigh_event_send(n, NULL);
751 } else {
752 if (fib_lookup(net, fl4, &res) == 0) {
753 struct fib_nh *nh = &FIB_RES_NH(res);
754
755 update_or_create_fnhe(nh, fl4->daddr, new_gw,
756 0, 0);
757 }
758 if (kill_route)
759 rt->dst.obsolete = DST_OBSOLETE_KILL;
760 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
761 }
762 neigh_release(n);
763 }
764 return;
765
766 reject_redirect:
767 #ifdef CONFIG_IP_ROUTE_VERBOSE
768 if (IN_DEV_LOG_MARTIANS(in_dev)) {
769 const struct iphdr *iph = (const struct iphdr *) skb->data;
770 __be32 daddr = iph->daddr;
771 __be32 saddr = iph->saddr;
772
773 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
774 " Advised path = %pI4 -> %pI4\n",
775 &old_gw, dev->name, &new_gw,
776 &saddr, &daddr);
777 }
778 #endif
779 ;
780 }
781
782 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
783 {
784 struct rtable *rt;
785 struct flowi4 fl4;
786 const struct iphdr *iph = (const struct iphdr *) skb->data;
787 int oif = skb->dev->ifindex;
788 u8 tos = RT_TOS(iph->tos);
789 u8 prot = iph->protocol;
790 u32 mark = skb->mark;
791
792 rt = (struct rtable *) dst;
793
794 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
795 __ip_do_redirect(rt, skb, &fl4, true);
796 }
797
798 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
799 {
800 struct rtable *rt = (struct rtable *)dst;
801 struct dst_entry *ret = dst;
802
803 if (rt) {
804 if (dst->obsolete > 0) {
805 ip_rt_put(rt);
806 ret = NULL;
807 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
808 rt->dst.expires) {
809 ip_rt_put(rt);
810 ret = NULL;
811 }
812 }
813 return ret;
814 }
815
816 /*
817 * Algorithm:
818 * 1. The first ip_rt_redirect_number redirects are sent
819 * with exponential backoff, then we stop sending them at all,
820 * assuming that the host ignores our redirects.
821 * 2. If we did not see packets requiring redirects
822 * during ip_rt_redirect_silence, we assume that the host
823 * forgot redirected route and start to send redirects again.
824 *
825 * This algorithm is much cheaper and more intelligent than dumb load limiting
826 * in icmp.c.
827 *
828 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
829 * and "frag. need" (breaks PMTU discovery) in icmp.c.
830 */
831
832 void ip_rt_send_redirect(struct sk_buff *skb)
833 {
834 struct rtable *rt = skb_rtable(skb);
835 struct in_device *in_dev;
836 struct inet_peer *peer;
837 struct net *net;
838 int log_martians;
839
840 rcu_read_lock();
841 in_dev = __in_dev_get_rcu(rt->dst.dev);
842 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
843 rcu_read_unlock();
844 return;
845 }
846 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
847 rcu_read_unlock();
848
849 net = dev_net(rt->dst.dev);
850 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
851 if (!peer) {
852 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
853 rt_nexthop(rt, ip_hdr(skb)->daddr));
854 return;
855 }
856
857 /* No redirected packets during ip_rt_redirect_silence;
858 * reset the algorithm.
859 */
860 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
861 peer->rate_tokens = 0;
862
863 /* Too many ignored redirects; do not send anything
864 * set dst.rate_last to the last seen redirected packet.
865 */
866 if (peer->rate_tokens >= ip_rt_redirect_number) {
867 peer->rate_last = jiffies;
868 goto out_put_peer;
869 }
870
871 /* Check for load limit; set rate_last to the latest sent
872 * redirect.
873 */
874 if (peer->rate_tokens == 0 ||
875 time_after(jiffies,
876 (peer->rate_last +
877 (ip_rt_redirect_load << peer->rate_tokens)))) {
878 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
879
880 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
881 peer->rate_last = jiffies;
882 ++peer->rate_tokens;
883 #ifdef CONFIG_IP_ROUTE_VERBOSE
884 if (log_martians &&
885 peer->rate_tokens == ip_rt_redirect_number)
886 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
887 &ip_hdr(skb)->saddr, inet_iif(skb),
888 &ip_hdr(skb)->daddr, &gw);
889 #endif
890 }
891 out_put_peer:
892 inet_putpeer(peer);
893 }
894
895 static int ip_error(struct sk_buff *skb)
896 {
897 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
898 struct rtable *rt = skb_rtable(skb);
899 struct inet_peer *peer;
900 unsigned long now;
901 struct net *net;
902 bool send;
903 int code;
904
905 /* IP on this device is disabled. */
906 if (!in_dev)
907 goto out;
908
909 net = dev_net(rt->dst.dev);
910 if (!IN_DEV_FORWARD(in_dev)) {
911 switch (rt->dst.error) {
912 case EHOSTUNREACH:
913 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
914 break;
915
916 case ENETUNREACH:
917 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
918 break;
919 }
920 goto out;
921 }
922
923 switch (rt->dst.error) {
924 case EINVAL:
925 default:
926 goto out;
927 case EHOSTUNREACH:
928 code = ICMP_HOST_UNREACH;
929 break;
930 case ENETUNREACH:
931 code = ICMP_NET_UNREACH;
932 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
933 break;
934 case EACCES:
935 code = ICMP_PKT_FILTERED;
936 break;
937 }
938
939 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
940
941 send = true;
942 if (peer) {
943 now = jiffies;
944 peer->rate_tokens += now - peer->rate_last;
945 if (peer->rate_tokens > ip_rt_error_burst)
946 peer->rate_tokens = ip_rt_error_burst;
947 peer->rate_last = now;
948 if (peer->rate_tokens >= ip_rt_error_cost)
949 peer->rate_tokens -= ip_rt_error_cost;
950 else
951 send = false;
952 inet_putpeer(peer);
953 }
954 if (send)
955 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
956
957 out: kfree_skb(skb);
958 return 0;
959 }
960
961 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
962 {
963 struct dst_entry *dst = &rt->dst;
964 struct fib_result res;
965
966 if (dst_metric_locked(dst, RTAX_MTU))
967 return;
968
969 if (ipv4_mtu(dst) < mtu)
970 return;
971
972 if (mtu < ip_rt_min_pmtu)
973 mtu = ip_rt_min_pmtu;
974
975 if (rt->rt_pmtu == mtu &&
976 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
977 return;
978
979 rcu_read_lock();
980 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
981 struct fib_nh *nh = &FIB_RES_NH(res);
982
983 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
984 jiffies + ip_rt_mtu_expires);
985 }
986 rcu_read_unlock();
987 }
988
989 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
990 struct sk_buff *skb, u32 mtu)
991 {
992 struct rtable *rt = (struct rtable *) dst;
993 struct flowi4 fl4;
994
995 ip_rt_build_flow_key(&fl4, sk, skb);
996 __ip_rt_update_pmtu(rt, &fl4, mtu);
997 }
998
999 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1000 int oif, u32 mark, u8 protocol, int flow_flags)
1001 {
1002 const struct iphdr *iph = (const struct iphdr *) skb->data;
1003 struct flowi4 fl4;
1004 struct rtable *rt;
1005
1006 if (!mark)
1007 mark = IP4_REPLY_MARK(net, skb->mark);
1008
1009 __build_flow_key(&fl4, NULL, iph, oif,
1010 RT_TOS(iph->tos), protocol, mark, flow_flags);
1011 rt = __ip_route_output_key(net, &fl4);
1012 if (!IS_ERR(rt)) {
1013 __ip_rt_update_pmtu(rt, &fl4, mtu);
1014 ip_rt_put(rt);
1015 }
1016 }
1017 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1018
1019 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1020 {
1021 const struct iphdr *iph = (const struct iphdr *) skb->data;
1022 struct flowi4 fl4;
1023 struct rtable *rt;
1024
1025 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1026
1027 if (!fl4.flowi4_mark)
1028 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1029
1030 rt = __ip_route_output_key(sock_net(sk), &fl4);
1031 if (!IS_ERR(rt)) {
1032 __ip_rt_update_pmtu(rt, &fl4, mtu);
1033 ip_rt_put(rt);
1034 }
1035 }
1036
1037 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1038 {
1039 const struct iphdr *iph = (const struct iphdr *) skb->data;
1040 struct flowi4 fl4;
1041 struct rtable *rt;
1042 struct dst_entry *odst = NULL;
1043 bool new = false;
1044
1045 bh_lock_sock(sk);
1046
1047 if (!ip_sk_accept_pmtu(sk))
1048 goto out;
1049
1050 odst = sk_dst_get(sk);
1051
1052 if (sock_owned_by_user(sk) || !odst) {
1053 __ipv4_sk_update_pmtu(skb, sk, mtu);
1054 goto out;
1055 }
1056
1057 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1058
1059 rt = (struct rtable *)odst;
1060 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1061 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1062 if (IS_ERR(rt))
1063 goto out;
1064
1065 new = true;
1066 }
1067
1068 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1069
1070 if (!dst_check(&rt->dst, 0)) {
1071 if (new)
1072 dst_release(&rt->dst);
1073
1074 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1075 if (IS_ERR(rt))
1076 goto out;
1077
1078 new = true;
1079 }
1080
1081 if (new)
1082 sk_dst_set(sk, &rt->dst);
1083
1084 out:
1085 bh_unlock_sock(sk);
1086 dst_release(odst);
1087 }
1088 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1089
1090 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1091 int oif, u32 mark, u8 protocol, int flow_flags)
1092 {
1093 const struct iphdr *iph = (const struct iphdr *) skb->data;
1094 struct flowi4 fl4;
1095 struct rtable *rt;
1096
1097 __build_flow_key(&fl4, NULL, iph, oif,
1098 RT_TOS(iph->tos), protocol, mark, flow_flags);
1099 rt = __ip_route_output_key(net, &fl4);
1100 if (!IS_ERR(rt)) {
1101 __ip_do_redirect(rt, skb, &fl4, false);
1102 ip_rt_put(rt);
1103 }
1104 }
1105 EXPORT_SYMBOL_GPL(ipv4_redirect);
1106
1107 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1108 {
1109 const struct iphdr *iph = (const struct iphdr *) skb->data;
1110 struct flowi4 fl4;
1111 struct rtable *rt;
1112
1113 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1114 rt = __ip_route_output_key(sock_net(sk), &fl4);
1115 if (!IS_ERR(rt)) {
1116 __ip_do_redirect(rt, skb, &fl4, false);
1117 ip_rt_put(rt);
1118 }
1119 }
1120 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1121
1122 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1123 {
1124 struct rtable *rt = (struct rtable *) dst;
1125
1126 /* All IPV4 dsts are created with ->obsolete set to the value
1127 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1128 * into this function always.
1129 *
1130 * When a PMTU/redirect information update invalidates a route,
1131 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1132 * DST_OBSOLETE_DEAD by dst_free().
1133 */
1134 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1135 return NULL;
1136 return dst;
1137 }
1138
1139 static void ipv4_link_failure(struct sk_buff *skb)
1140 {
1141 struct rtable *rt;
1142
1143 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1144
1145 rt = skb_rtable(skb);
1146 if (rt)
1147 dst_set_expires(&rt->dst, 0);
1148 }
1149
1150 static int ip_rt_bug(struct sock *sk, struct sk_buff *skb)
1151 {
1152 pr_debug("%s: %pI4 -> %pI4, %s\n",
1153 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1154 skb->dev ? skb->dev->name : "?");
1155 kfree_skb(skb);
1156 WARN_ON(1);
1157 return 0;
1158 }
1159
1160 /*
1161 We do not cache source address of outgoing interface,
1162 because it is used only by IP RR, TS and SRR options,
1163 so that it out of fast path.
1164
1165 BTW remember: "addr" is allowed to be not aligned
1166 in IP options!
1167 */
1168
1169 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1170 {
1171 __be32 src;
1172
1173 if (rt_is_output_route(rt))
1174 src = ip_hdr(skb)->saddr;
1175 else {
1176 struct fib_result res;
1177 struct flowi4 fl4;
1178 struct iphdr *iph;
1179
1180 iph = ip_hdr(skb);
1181
1182 memset(&fl4, 0, sizeof(fl4));
1183 fl4.daddr = iph->daddr;
1184 fl4.saddr = iph->saddr;
1185 fl4.flowi4_tos = RT_TOS(iph->tos);
1186 fl4.flowi4_oif = rt->dst.dev->ifindex;
1187 fl4.flowi4_iif = skb->dev->ifindex;
1188 fl4.flowi4_mark = skb->mark;
1189
1190 rcu_read_lock();
1191 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1192 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1193 else
1194 src = inet_select_addr(rt->dst.dev,
1195 rt_nexthop(rt, iph->daddr),
1196 RT_SCOPE_UNIVERSE);
1197 rcu_read_unlock();
1198 }
1199 memcpy(addr, &src, 4);
1200 }
1201
1202 #ifdef CONFIG_IP_ROUTE_CLASSID
1203 static void set_class_tag(struct rtable *rt, u32 tag)
1204 {
1205 if (!(rt->dst.tclassid & 0xFFFF))
1206 rt->dst.tclassid |= tag & 0xFFFF;
1207 if (!(rt->dst.tclassid & 0xFFFF0000))
1208 rt->dst.tclassid |= tag & 0xFFFF0000;
1209 }
1210 #endif
1211
1212 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1213 {
1214 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1215
1216 if (advmss == 0) {
1217 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1218 ip_rt_min_advmss);
1219 if (advmss > 65535 - 40)
1220 advmss = 65535 - 40;
1221 }
1222 return advmss;
1223 }
1224
1225 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1226 {
1227 const struct rtable *rt = (const struct rtable *) dst;
1228 unsigned int mtu = rt->rt_pmtu;
1229
1230 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1231 mtu = dst_metric_raw(dst, RTAX_MTU);
1232
1233 if (mtu)
1234 return mtu;
1235
1236 mtu = dst->dev->mtu;
1237
1238 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1239 if (rt->rt_uses_gateway && mtu > 576)
1240 mtu = 576;
1241 }
1242
1243 return min_t(unsigned int, mtu, IP_MAX_MTU);
1244 }
1245
1246 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1247 {
1248 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1249 struct fib_nh_exception *fnhe;
1250 u32 hval;
1251
1252 if (!hash)
1253 return NULL;
1254
1255 hval = fnhe_hashfun(daddr);
1256
1257 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1258 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1259 if (fnhe->fnhe_daddr == daddr)
1260 return fnhe;
1261 }
1262 return NULL;
1263 }
1264
1265 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1266 __be32 daddr)
1267 {
1268 bool ret = false;
1269
1270 spin_lock_bh(&fnhe_lock);
1271
1272 if (daddr == fnhe->fnhe_daddr) {
1273 struct rtable __rcu **porig;
1274 struct rtable *orig;
1275 int genid = fnhe_genid(dev_net(rt->dst.dev));
1276
1277 if (rt_is_input_route(rt))
1278 porig = &fnhe->fnhe_rth_input;
1279 else
1280 porig = &fnhe->fnhe_rth_output;
1281 orig = rcu_dereference(*porig);
1282
1283 if (fnhe->fnhe_genid != genid) {
1284 fnhe->fnhe_genid = genid;
1285 fnhe->fnhe_gw = 0;
1286 fnhe->fnhe_pmtu = 0;
1287 fnhe->fnhe_expires = 0;
1288 fnhe_flush_routes(fnhe);
1289 orig = NULL;
1290 }
1291 fill_route_from_fnhe(rt, fnhe);
1292 if (!rt->rt_gateway)
1293 rt->rt_gateway = daddr;
1294
1295 if (!(rt->dst.flags & DST_NOCACHE)) {
1296 rcu_assign_pointer(*porig, rt);
1297 if (orig)
1298 rt_free(orig);
1299 ret = true;
1300 }
1301
1302 fnhe->fnhe_stamp = jiffies;
1303 }
1304 spin_unlock_bh(&fnhe_lock);
1305
1306 return ret;
1307 }
1308
1309 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1310 {
1311 struct rtable *orig, *prev, **p;
1312 bool ret = true;
1313
1314 if (rt_is_input_route(rt)) {
1315 p = (struct rtable **)&nh->nh_rth_input;
1316 } else {
1317 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1318 }
1319 orig = *p;
1320
1321 prev = cmpxchg(p, orig, rt);
1322 if (prev == orig) {
1323 if (orig)
1324 rt_free(orig);
1325 } else
1326 ret = false;
1327
1328 return ret;
1329 }
1330
1331 struct uncached_list {
1332 spinlock_t lock;
1333 struct list_head head;
1334 };
1335
1336 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1337
1338 static void rt_add_uncached_list(struct rtable *rt)
1339 {
1340 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1341
1342 rt->rt_uncached_list = ul;
1343
1344 spin_lock_bh(&ul->lock);
1345 list_add_tail(&rt->rt_uncached, &ul->head);
1346 spin_unlock_bh(&ul->lock);
1347 }
1348
1349 static void ipv4_dst_destroy(struct dst_entry *dst)
1350 {
1351 struct rtable *rt = (struct rtable *) dst;
1352
1353 if (!list_empty(&rt->rt_uncached)) {
1354 struct uncached_list *ul = rt->rt_uncached_list;
1355
1356 spin_lock_bh(&ul->lock);
1357 list_del(&rt->rt_uncached);
1358 spin_unlock_bh(&ul->lock);
1359 }
1360 }
1361
1362 void rt_flush_dev(struct net_device *dev)
1363 {
1364 struct net *net = dev_net(dev);
1365 struct rtable *rt;
1366 int cpu;
1367
1368 for_each_possible_cpu(cpu) {
1369 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1370
1371 spin_lock_bh(&ul->lock);
1372 list_for_each_entry(rt, &ul->head, rt_uncached) {
1373 if (rt->dst.dev != dev)
1374 continue;
1375 rt->dst.dev = net->loopback_dev;
1376 dev_hold(rt->dst.dev);
1377 dev_put(dev);
1378 }
1379 spin_unlock_bh(&ul->lock);
1380 }
1381 }
1382
1383 static bool rt_cache_valid(const struct rtable *rt)
1384 {
1385 return rt &&
1386 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1387 !rt_is_expired(rt);
1388 }
1389
1390 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1391 const struct fib_result *res,
1392 struct fib_nh_exception *fnhe,
1393 struct fib_info *fi, u16 type, u32 itag)
1394 {
1395 bool cached = false;
1396
1397 if (fi) {
1398 struct fib_nh *nh = &FIB_RES_NH(*res);
1399
1400 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1401 rt->rt_gateway = nh->nh_gw;
1402 rt->rt_uses_gateway = 1;
1403 }
1404 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1405 #ifdef CONFIG_IP_ROUTE_CLASSID
1406 rt->dst.tclassid = nh->nh_tclassid;
1407 #endif
1408 if (unlikely(fnhe))
1409 cached = rt_bind_exception(rt, fnhe, daddr);
1410 else if (!(rt->dst.flags & DST_NOCACHE))
1411 cached = rt_cache_route(nh, rt);
1412 if (unlikely(!cached)) {
1413 /* Routes we intend to cache in nexthop exception or
1414 * FIB nexthop have the DST_NOCACHE bit clear.
1415 * However, if we are unsuccessful at storing this
1416 * route into the cache we really need to set it.
1417 */
1418 rt->dst.flags |= DST_NOCACHE;
1419 if (!rt->rt_gateway)
1420 rt->rt_gateway = daddr;
1421 rt_add_uncached_list(rt);
1422 }
1423 } else
1424 rt_add_uncached_list(rt);
1425
1426 #ifdef CONFIG_IP_ROUTE_CLASSID
1427 #ifdef CONFIG_IP_MULTIPLE_TABLES
1428 set_class_tag(rt, res->tclassid);
1429 #endif
1430 set_class_tag(rt, itag);
1431 #endif
1432 }
1433
1434 static struct rtable *rt_dst_alloc(struct net_device *dev,
1435 bool nopolicy, bool noxfrm, bool will_cache)
1436 {
1437 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1438 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1439 (nopolicy ? DST_NOPOLICY : 0) |
1440 (noxfrm ? DST_NOXFRM : 0));
1441 }
1442
1443 /* called in rcu_read_lock() section */
1444 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1445 u8 tos, struct net_device *dev, int our)
1446 {
1447 struct rtable *rth;
1448 struct in_device *in_dev = __in_dev_get_rcu(dev);
1449 u32 itag = 0;
1450 int err;
1451
1452 /* Primary sanity checks. */
1453
1454 if (!in_dev)
1455 return -EINVAL;
1456
1457 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1458 skb->protocol != htons(ETH_P_IP))
1459 goto e_inval;
1460
1461 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1462 if (ipv4_is_loopback(saddr))
1463 goto e_inval;
1464
1465 if (ipv4_is_zeronet(saddr)) {
1466 if (!ipv4_is_local_multicast(daddr))
1467 goto e_inval;
1468 } else {
1469 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1470 in_dev, &itag);
1471 if (err < 0)
1472 goto e_err;
1473 }
1474 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1475 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1476 if (!rth)
1477 goto e_nobufs;
1478
1479 #ifdef CONFIG_IP_ROUTE_CLASSID
1480 rth->dst.tclassid = itag;
1481 #endif
1482 rth->dst.output = ip_rt_bug;
1483
1484 rth->rt_genid = rt_genid_ipv4(dev_net(dev));
1485 rth->rt_flags = RTCF_MULTICAST;
1486 rth->rt_type = RTN_MULTICAST;
1487 rth->rt_is_input= 1;
1488 rth->rt_iif = 0;
1489 rth->rt_pmtu = 0;
1490 rth->rt_gateway = 0;
1491 rth->rt_uses_gateway = 0;
1492 INIT_LIST_HEAD(&rth->rt_uncached);
1493 if (our) {
1494 rth->dst.input= ip_local_deliver;
1495 rth->rt_flags |= RTCF_LOCAL;
1496 }
1497
1498 #ifdef CONFIG_IP_MROUTE
1499 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1500 rth->dst.input = ip_mr_input;
1501 #endif
1502 RT_CACHE_STAT_INC(in_slow_mc);
1503
1504 skb_dst_set(skb, &rth->dst);
1505 return 0;
1506
1507 e_nobufs:
1508 return -ENOBUFS;
1509 e_inval:
1510 return -EINVAL;
1511 e_err:
1512 return err;
1513 }
1514
1515
1516 static void ip_handle_martian_source(struct net_device *dev,
1517 struct in_device *in_dev,
1518 struct sk_buff *skb,
1519 __be32 daddr,
1520 __be32 saddr)
1521 {
1522 RT_CACHE_STAT_INC(in_martian_src);
1523 #ifdef CONFIG_IP_ROUTE_VERBOSE
1524 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1525 /*
1526 * RFC1812 recommendation, if source is martian,
1527 * the only hint is MAC header.
1528 */
1529 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1530 &daddr, &saddr, dev->name);
1531 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1532 print_hex_dump(KERN_WARNING, "ll header: ",
1533 DUMP_PREFIX_OFFSET, 16, 1,
1534 skb_mac_header(skb),
1535 dev->hard_header_len, true);
1536 }
1537 }
1538 #endif
1539 }
1540
1541 /* called in rcu_read_lock() section */
1542 static int __mkroute_input(struct sk_buff *skb,
1543 const struct fib_result *res,
1544 struct in_device *in_dev,
1545 __be32 daddr, __be32 saddr, u32 tos)
1546 {
1547 struct fib_nh_exception *fnhe;
1548 struct rtable *rth;
1549 int err;
1550 struct in_device *out_dev;
1551 unsigned int flags = 0;
1552 bool do_cache;
1553 u32 itag = 0;
1554
1555 /* get a working reference to the output device */
1556 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1557 if (!out_dev) {
1558 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1559 return -EINVAL;
1560 }
1561
1562 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1563 in_dev->dev, in_dev, &itag);
1564 if (err < 0) {
1565 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1566 saddr);
1567
1568 goto cleanup;
1569 }
1570
1571 do_cache = res->fi && !itag;
1572 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1573 skb->protocol == htons(ETH_P_IP) &&
1574 (IN_DEV_SHARED_MEDIA(out_dev) ||
1575 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1576 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1577
1578 if (skb->protocol != htons(ETH_P_IP)) {
1579 /* Not IP (i.e. ARP). Do not create route, if it is
1580 * invalid for proxy arp. DNAT routes are always valid.
1581 *
1582 * Proxy arp feature have been extended to allow, ARP
1583 * replies back to the same interface, to support
1584 * Private VLAN switch technologies. See arp.c.
1585 */
1586 if (out_dev == in_dev &&
1587 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1588 err = -EINVAL;
1589 goto cleanup;
1590 }
1591 }
1592
1593 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1594 if (do_cache) {
1595 if (fnhe)
1596 rth = rcu_dereference(fnhe->fnhe_rth_input);
1597 else
1598 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1599
1600 if (rt_cache_valid(rth)) {
1601 skb_dst_set_noref(skb, &rth->dst);
1602 goto out;
1603 }
1604 }
1605
1606 rth = rt_dst_alloc(out_dev->dev,
1607 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1608 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1609 if (!rth) {
1610 err = -ENOBUFS;
1611 goto cleanup;
1612 }
1613
1614 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev));
1615 rth->rt_flags = flags;
1616 rth->rt_type = res->type;
1617 rth->rt_is_input = 1;
1618 rth->rt_iif = 0;
1619 rth->rt_pmtu = 0;
1620 rth->rt_gateway = 0;
1621 rth->rt_uses_gateway = 0;
1622 INIT_LIST_HEAD(&rth->rt_uncached);
1623 RT_CACHE_STAT_INC(in_slow_tot);
1624
1625 rth->dst.input = ip_forward;
1626 rth->dst.output = ip_output;
1627
1628 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1629 skb_dst_set(skb, &rth->dst);
1630 out:
1631 err = 0;
1632 cleanup:
1633 return err;
1634 }
1635
1636 static int ip_mkroute_input(struct sk_buff *skb,
1637 struct fib_result *res,
1638 const struct flowi4 *fl4,
1639 struct in_device *in_dev,
1640 __be32 daddr, __be32 saddr, u32 tos)
1641 {
1642 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1643 if (res->fi && res->fi->fib_nhs > 1)
1644 fib_select_multipath(res);
1645 #endif
1646
1647 /* create a routing cache entry */
1648 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1649 }
1650
1651 /*
1652 * NOTE. We drop all the packets that has local source
1653 * addresses, because every properly looped back packet
1654 * must have correct destination already attached by output routine.
1655 *
1656 * Such approach solves two big problems:
1657 * 1. Not simplex devices are handled properly.
1658 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1659 * called with rcu_read_lock()
1660 */
1661
1662 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1663 u8 tos, struct net_device *dev)
1664 {
1665 struct fib_result res;
1666 struct in_device *in_dev = __in_dev_get_rcu(dev);
1667 struct flowi4 fl4;
1668 unsigned int flags = 0;
1669 u32 itag = 0;
1670 struct rtable *rth;
1671 int err = -EINVAL;
1672 struct net *net = dev_net(dev);
1673 bool do_cache;
1674
1675 /* IP on this device is disabled. */
1676
1677 if (!in_dev)
1678 goto out;
1679
1680 /* Check for the most weird martians, which can be not detected
1681 by fib_lookup.
1682 */
1683
1684 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1685 goto martian_source;
1686
1687 res.fi = NULL;
1688 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1689 goto brd_input;
1690
1691 /* Accept zero addresses only to limited broadcast;
1692 * I even do not know to fix it or not. Waiting for complains :-)
1693 */
1694 if (ipv4_is_zeronet(saddr))
1695 goto martian_source;
1696
1697 if (ipv4_is_zeronet(daddr))
1698 goto martian_destination;
1699
1700 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1701 * and call it once if daddr or/and saddr are loopback addresses
1702 */
1703 if (ipv4_is_loopback(daddr)) {
1704 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1705 goto martian_destination;
1706 } else if (ipv4_is_loopback(saddr)) {
1707 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1708 goto martian_source;
1709 }
1710
1711 /*
1712 * Now we are ready to route packet.
1713 */
1714 fl4.flowi4_oif = 0;
1715 fl4.flowi4_iif = dev->ifindex;
1716 fl4.flowi4_mark = skb->mark;
1717 fl4.flowi4_tos = tos;
1718 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1719 fl4.daddr = daddr;
1720 fl4.saddr = saddr;
1721 err = fib_lookup(net, &fl4, &res);
1722 if (err != 0) {
1723 if (!IN_DEV_FORWARD(in_dev))
1724 err = -EHOSTUNREACH;
1725 goto no_route;
1726 }
1727
1728 if (res.type == RTN_BROADCAST)
1729 goto brd_input;
1730
1731 if (res.type == RTN_LOCAL) {
1732 err = fib_validate_source(skb, saddr, daddr, tos,
1733 0, dev, in_dev, &itag);
1734 if (err < 0)
1735 goto martian_source_keep_err;
1736 goto local_input;
1737 }
1738
1739 if (!IN_DEV_FORWARD(in_dev)) {
1740 err = -EHOSTUNREACH;
1741 goto no_route;
1742 }
1743 if (res.type != RTN_UNICAST)
1744 goto martian_destination;
1745
1746 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1747 out: return err;
1748
1749 brd_input:
1750 if (skb->protocol != htons(ETH_P_IP))
1751 goto e_inval;
1752
1753 if (!ipv4_is_zeronet(saddr)) {
1754 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1755 in_dev, &itag);
1756 if (err < 0)
1757 goto martian_source_keep_err;
1758 }
1759 flags |= RTCF_BROADCAST;
1760 res.type = RTN_BROADCAST;
1761 RT_CACHE_STAT_INC(in_brd);
1762
1763 local_input:
1764 do_cache = false;
1765 if (res.fi) {
1766 if (!itag) {
1767 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1768 if (rt_cache_valid(rth)) {
1769 skb_dst_set_noref(skb, &rth->dst);
1770 err = 0;
1771 goto out;
1772 }
1773 do_cache = true;
1774 }
1775 }
1776
1777 rth = rt_dst_alloc(net->loopback_dev,
1778 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1779 if (!rth)
1780 goto e_nobufs;
1781
1782 rth->dst.input= ip_local_deliver;
1783 rth->dst.output= ip_rt_bug;
1784 #ifdef CONFIG_IP_ROUTE_CLASSID
1785 rth->dst.tclassid = itag;
1786 #endif
1787
1788 rth->rt_genid = rt_genid_ipv4(net);
1789 rth->rt_flags = flags|RTCF_LOCAL;
1790 rth->rt_type = res.type;
1791 rth->rt_is_input = 1;
1792 rth->rt_iif = 0;
1793 rth->rt_pmtu = 0;
1794 rth->rt_gateway = 0;
1795 rth->rt_uses_gateway = 0;
1796 INIT_LIST_HEAD(&rth->rt_uncached);
1797 RT_CACHE_STAT_INC(in_slow_tot);
1798 if (res.type == RTN_UNREACHABLE) {
1799 rth->dst.input= ip_error;
1800 rth->dst.error= -err;
1801 rth->rt_flags &= ~RTCF_LOCAL;
1802 }
1803 if (do_cache) {
1804 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1805 rth->dst.flags |= DST_NOCACHE;
1806 rt_add_uncached_list(rth);
1807 }
1808 }
1809 skb_dst_set(skb, &rth->dst);
1810 err = 0;
1811 goto out;
1812
1813 no_route:
1814 RT_CACHE_STAT_INC(in_no_route);
1815 res.type = RTN_UNREACHABLE;
1816 res.fi = NULL;
1817 goto local_input;
1818
1819 /*
1820 * Do not cache martian addresses: they should be logged (RFC1812)
1821 */
1822 martian_destination:
1823 RT_CACHE_STAT_INC(in_martian_dst);
1824 #ifdef CONFIG_IP_ROUTE_VERBOSE
1825 if (IN_DEV_LOG_MARTIANS(in_dev))
1826 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1827 &daddr, &saddr, dev->name);
1828 #endif
1829
1830 e_inval:
1831 err = -EINVAL;
1832 goto out;
1833
1834 e_nobufs:
1835 err = -ENOBUFS;
1836 goto out;
1837
1838 martian_source:
1839 err = -EINVAL;
1840 martian_source_keep_err:
1841 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1842 goto out;
1843 }
1844
1845 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1846 u8 tos, struct net_device *dev)
1847 {
1848 int res;
1849
1850 rcu_read_lock();
1851
1852 /* Multicast recognition logic is moved from route cache to here.
1853 The problem was that too many Ethernet cards have broken/missing
1854 hardware multicast filters :-( As result the host on multicasting
1855 network acquires a lot of useless route cache entries, sort of
1856 SDR messages from all the world. Now we try to get rid of them.
1857 Really, provided software IP multicast filter is organized
1858 reasonably (at least, hashed), it does not result in a slowdown
1859 comparing with route cache reject entries.
1860 Note, that multicast routers are not affected, because
1861 route cache entry is created eventually.
1862 */
1863 if (ipv4_is_multicast(daddr)) {
1864 struct in_device *in_dev = __in_dev_get_rcu(dev);
1865
1866 if (in_dev) {
1867 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1868 ip_hdr(skb)->protocol);
1869 if (our
1870 #ifdef CONFIG_IP_MROUTE
1871 ||
1872 (!ipv4_is_local_multicast(daddr) &&
1873 IN_DEV_MFORWARD(in_dev))
1874 #endif
1875 ) {
1876 int res = ip_route_input_mc(skb, daddr, saddr,
1877 tos, dev, our);
1878 rcu_read_unlock();
1879 return res;
1880 }
1881 }
1882 rcu_read_unlock();
1883 return -EINVAL;
1884 }
1885 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1886 rcu_read_unlock();
1887 return res;
1888 }
1889 EXPORT_SYMBOL(ip_route_input_noref);
1890
1891 /* called with rcu_read_lock() */
1892 static struct rtable *__mkroute_output(const struct fib_result *res,
1893 const struct flowi4 *fl4, int orig_oif,
1894 struct net_device *dev_out,
1895 unsigned int flags)
1896 {
1897 struct fib_info *fi = res->fi;
1898 struct fib_nh_exception *fnhe;
1899 struct in_device *in_dev;
1900 u16 type = res->type;
1901 struct rtable *rth;
1902 bool do_cache;
1903
1904 in_dev = __in_dev_get_rcu(dev_out);
1905 if (!in_dev)
1906 return ERR_PTR(-EINVAL);
1907
1908 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1909 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1910 return ERR_PTR(-EINVAL);
1911
1912 if (ipv4_is_lbcast(fl4->daddr))
1913 type = RTN_BROADCAST;
1914 else if (ipv4_is_multicast(fl4->daddr))
1915 type = RTN_MULTICAST;
1916 else if (ipv4_is_zeronet(fl4->daddr))
1917 return ERR_PTR(-EINVAL);
1918
1919 if (dev_out->flags & IFF_LOOPBACK)
1920 flags |= RTCF_LOCAL;
1921
1922 do_cache = true;
1923 if (type == RTN_BROADCAST) {
1924 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1925 fi = NULL;
1926 } else if (type == RTN_MULTICAST) {
1927 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1928 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1929 fl4->flowi4_proto))
1930 flags &= ~RTCF_LOCAL;
1931 else
1932 do_cache = false;
1933 /* If multicast route do not exist use
1934 * default one, but do not gateway in this case.
1935 * Yes, it is hack.
1936 */
1937 if (fi && res->prefixlen < 4)
1938 fi = NULL;
1939 }
1940
1941 fnhe = NULL;
1942 do_cache &= fi != NULL;
1943 if (do_cache) {
1944 struct rtable __rcu **prth;
1945 struct fib_nh *nh = &FIB_RES_NH(*res);
1946
1947 fnhe = find_exception(nh, fl4->daddr);
1948 if (fnhe)
1949 prth = &fnhe->fnhe_rth_output;
1950 else {
1951 if (unlikely(fl4->flowi4_flags &
1952 FLOWI_FLAG_KNOWN_NH &&
1953 !(nh->nh_gw &&
1954 nh->nh_scope == RT_SCOPE_LINK))) {
1955 do_cache = false;
1956 goto add;
1957 }
1958 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
1959 }
1960 rth = rcu_dereference(*prth);
1961 if (rt_cache_valid(rth)) {
1962 dst_hold(&rth->dst);
1963 return rth;
1964 }
1965 }
1966
1967 add:
1968 rth = rt_dst_alloc(dev_out,
1969 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1970 IN_DEV_CONF_GET(in_dev, NOXFRM),
1971 do_cache);
1972 if (!rth)
1973 return ERR_PTR(-ENOBUFS);
1974
1975 rth->dst.output = ip_output;
1976
1977 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out));
1978 rth->rt_flags = flags;
1979 rth->rt_type = type;
1980 rth->rt_is_input = 0;
1981 rth->rt_iif = orig_oif ? : 0;
1982 rth->rt_pmtu = 0;
1983 rth->rt_gateway = 0;
1984 rth->rt_uses_gateway = 0;
1985 INIT_LIST_HEAD(&rth->rt_uncached);
1986
1987 RT_CACHE_STAT_INC(out_slow_tot);
1988
1989 if (flags & RTCF_LOCAL)
1990 rth->dst.input = ip_local_deliver;
1991 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1992 if (flags & RTCF_LOCAL &&
1993 !(dev_out->flags & IFF_LOOPBACK)) {
1994 rth->dst.output = ip_mc_output;
1995 RT_CACHE_STAT_INC(out_slow_mc);
1996 }
1997 #ifdef CONFIG_IP_MROUTE
1998 if (type == RTN_MULTICAST) {
1999 if (IN_DEV_MFORWARD(in_dev) &&
2000 !ipv4_is_local_multicast(fl4->daddr)) {
2001 rth->dst.input = ip_mr_input;
2002 rth->dst.output = ip_mc_output;
2003 }
2004 }
2005 #endif
2006 }
2007
2008 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
2009
2010 return rth;
2011 }
2012
2013 /*
2014 * Major route resolver routine.
2015 */
2016
2017 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
2018 {
2019 struct net_device *dev_out = NULL;
2020 __u8 tos = RT_FL_TOS(fl4);
2021 unsigned int flags = 0;
2022 struct fib_result res;
2023 struct rtable *rth;
2024 int orig_oif;
2025
2026 res.tclassid = 0;
2027 res.fi = NULL;
2028 res.table = NULL;
2029
2030 orig_oif = fl4->flowi4_oif;
2031
2032 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2033 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2034 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2035 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2036
2037 rcu_read_lock();
2038 if (fl4->saddr) {
2039 rth = ERR_PTR(-EINVAL);
2040 if (ipv4_is_multicast(fl4->saddr) ||
2041 ipv4_is_lbcast(fl4->saddr) ||
2042 ipv4_is_zeronet(fl4->saddr))
2043 goto out;
2044
2045 /* I removed check for oif == dev_out->oif here.
2046 It was wrong for two reasons:
2047 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2048 is assigned to multiple interfaces.
2049 2. Moreover, we are allowed to send packets with saddr
2050 of another iface. --ANK
2051 */
2052
2053 if (fl4->flowi4_oif == 0 &&
2054 (ipv4_is_multicast(fl4->daddr) ||
2055 ipv4_is_lbcast(fl4->daddr))) {
2056 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2057 dev_out = __ip_dev_find(net, fl4->saddr, false);
2058 if (!dev_out)
2059 goto out;
2060
2061 /* Special hack: user can direct multicasts
2062 and limited broadcast via necessary interface
2063 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2064 This hack is not just for fun, it allows
2065 vic,vat and friends to work.
2066 They bind socket to loopback, set ttl to zero
2067 and expect that it will work.
2068 From the viewpoint of routing cache they are broken,
2069 because we are not allowed to build multicast path
2070 with loopback source addr (look, routing cache
2071 cannot know, that ttl is zero, so that packet
2072 will not leave this host and route is valid).
2073 Luckily, this hack is good workaround.
2074 */
2075
2076 fl4->flowi4_oif = dev_out->ifindex;
2077 goto make_route;
2078 }
2079
2080 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2081 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2082 if (!__ip_dev_find(net, fl4->saddr, false))
2083 goto out;
2084 }
2085 }
2086
2087
2088 if (fl4->flowi4_oif) {
2089 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2090 rth = ERR_PTR(-ENODEV);
2091 if (!dev_out)
2092 goto out;
2093
2094 /* RACE: Check return value of inet_select_addr instead. */
2095 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2096 rth = ERR_PTR(-ENETUNREACH);
2097 goto out;
2098 }
2099 if (ipv4_is_local_multicast(fl4->daddr) ||
2100 ipv4_is_lbcast(fl4->daddr)) {
2101 if (!fl4->saddr)
2102 fl4->saddr = inet_select_addr(dev_out, 0,
2103 RT_SCOPE_LINK);
2104 goto make_route;
2105 }
2106 if (!fl4->saddr) {
2107 if (ipv4_is_multicast(fl4->daddr))
2108 fl4->saddr = inet_select_addr(dev_out, 0,
2109 fl4->flowi4_scope);
2110 else if (!fl4->daddr)
2111 fl4->saddr = inet_select_addr(dev_out, 0,
2112 RT_SCOPE_HOST);
2113 }
2114 }
2115
2116 if (!fl4->daddr) {
2117 fl4->daddr = fl4->saddr;
2118 if (!fl4->daddr)
2119 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2120 dev_out = net->loopback_dev;
2121 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2122 res.type = RTN_LOCAL;
2123 flags |= RTCF_LOCAL;
2124 goto make_route;
2125 }
2126
2127 if (fib_lookup(net, fl4, &res)) {
2128 res.fi = NULL;
2129 res.table = NULL;
2130 if (fl4->flowi4_oif) {
2131 /* Apparently, routing tables are wrong. Assume,
2132 that the destination is on link.
2133
2134 WHY? DW.
2135 Because we are allowed to send to iface
2136 even if it has NO routes and NO assigned
2137 addresses. When oif is specified, routing
2138 tables are looked up with only one purpose:
2139 to catch if destination is gatewayed, rather than
2140 direct. Moreover, if MSG_DONTROUTE is set,
2141 we send packet, ignoring both routing tables
2142 and ifaddr state. --ANK
2143
2144
2145 We could make it even if oif is unknown,
2146 likely IPv6, but we do not.
2147 */
2148
2149 if (fl4->saddr == 0)
2150 fl4->saddr = inet_select_addr(dev_out, 0,
2151 RT_SCOPE_LINK);
2152 res.type = RTN_UNICAST;
2153 goto make_route;
2154 }
2155 rth = ERR_PTR(-ENETUNREACH);
2156 goto out;
2157 }
2158
2159 if (res.type == RTN_LOCAL) {
2160 if (!fl4->saddr) {
2161 if (res.fi->fib_prefsrc)
2162 fl4->saddr = res.fi->fib_prefsrc;
2163 else
2164 fl4->saddr = fl4->daddr;
2165 }
2166 dev_out = net->loopback_dev;
2167 fl4->flowi4_oif = dev_out->ifindex;
2168 flags |= RTCF_LOCAL;
2169 goto make_route;
2170 }
2171
2172 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2173 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2174 fib_select_multipath(&res);
2175 else
2176 #endif
2177 if (!res.prefixlen &&
2178 res.table->tb_num_default > 1 &&
2179 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2180 fib_select_default(&res);
2181
2182 if (!fl4->saddr)
2183 fl4->saddr = FIB_RES_PREFSRC(net, res);
2184
2185 dev_out = FIB_RES_DEV(res);
2186 fl4->flowi4_oif = dev_out->ifindex;
2187
2188
2189 make_route:
2190 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2191
2192 out:
2193 rcu_read_unlock();
2194 return rth;
2195 }
2196 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2197
2198 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2199 {
2200 return NULL;
2201 }
2202
2203 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2204 {
2205 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2206
2207 return mtu ? : dst->dev->mtu;
2208 }
2209
2210 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2211 struct sk_buff *skb, u32 mtu)
2212 {
2213 }
2214
2215 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2216 struct sk_buff *skb)
2217 {
2218 }
2219
2220 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2221 unsigned long old)
2222 {
2223 return NULL;
2224 }
2225
2226 static struct dst_ops ipv4_dst_blackhole_ops = {
2227 .family = AF_INET,
2228 .check = ipv4_blackhole_dst_check,
2229 .mtu = ipv4_blackhole_mtu,
2230 .default_advmss = ipv4_default_advmss,
2231 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2232 .redirect = ipv4_rt_blackhole_redirect,
2233 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2234 .neigh_lookup = ipv4_neigh_lookup,
2235 };
2236
2237 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2238 {
2239 struct rtable *ort = (struct rtable *) dst_orig;
2240 struct rtable *rt;
2241
2242 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2243 if (rt) {
2244 struct dst_entry *new = &rt->dst;
2245
2246 new->__use = 1;
2247 new->input = dst_discard;
2248 new->output = dst_discard_sk;
2249
2250 new->dev = ort->dst.dev;
2251 if (new->dev)
2252 dev_hold(new->dev);
2253
2254 rt->rt_is_input = ort->rt_is_input;
2255 rt->rt_iif = ort->rt_iif;
2256 rt->rt_pmtu = ort->rt_pmtu;
2257
2258 rt->rt_genid = rt_genid_ipv4(net);
2259 rt->rt_flags = ort->rt_flags;
2260 rt->rt_type = ort->rt_type;
2261 rt->rt_gateway = ort->rt_gateway;
2262 rt->rt_uses_gateway = ort->rt_uses_gateway;
2263
2264 INIT_LIST_HEAD(&rt->rt_uncached);
2265
2266 dst_free(new);
2267 }
2268
2269 dst_release(dst_orig);
2270
2271 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2272 }
2273
2274 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2275 struct sock *sk)
2276 {
2277 struct rtable *rt = __ip_route_output_key(net, flp4);
2278
2279 if (IS_ERR(rt))
2280 return rt;
2281
2282 if (flp4->flowi4_proto)
2283 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2284 flowi4_to_flowi(flp4),
2285 sk, 0);
2286
2287 return rt;
2288 }
2289 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2290
2291 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2292 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2293 u32 seq, int event, int nowait, unsigned int flags)
2294 {
2295 struct rtable *rt = skb_rtable(skb);
2296 struct rtmsg *r;
2297 struct nlmsghdr *nlh;
2298 unsigned long expires = 0;
2299 u32 error;
2300 u32 metrics[RTAX_MAX];
2301
2302 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2303 if (!nlh)
2304 return -EMSGSIZE;
2305
2306 r = nlmsg_data(nlh);
2307 r->rtm_family = AF_INET;
2308 r->rtm_dst_len = 32;
2309 r->rtm_src_len = 0;
2310 r->rtm_tos = fl4->flowi4_tos;
2311 r->rtm_table = RT_TABLE_MAIN;
2312 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2313 goto nla_put_failure;
2314 r->rtm_type = rt->rt_type;
2315 r->rtm_scope = RT_SCOPE_UNIVERSE;
2316 r->rtm_protocol = RTPROT_UNSPEC;
2317 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2318 if (rt->rt_flags & RTCF_NOTIFY)
2319 r->rtm_flags |= RTM_F_NOTIFY;
2320 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2321 r->rtm_flags |= RTCF_DOREDIRECT;
2322
2323 if (nla_put_in_addr(skb, RTA_DST, dst))
2324 goto nla_put_failure;
2325 if (src) {
2326 r->rtm_src_len = 32;
2327 if (nla_put_in_addr(skb, RTA_SRC, src))
2328 goto nla_put_failure;
2329 }
2330 if (rt->dst.dev &&
2331 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2332 goto nla_put_failure;
2333 #ifdef CONFIG_IP_ROUTE_CLASSID
2334 if (rt->dst.tclassid &&
2335 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2336 goto nla_put_failure;
2337 #endif
2338 if (!rt_is_input_route(rt) &&
2339 fl4->saddr != src) {
2340 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2341 goto nla_put_failure;
2342 }
2343 if (rt->rt_uses_gateway &&
2344 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2345 goto nla_put_failure;
2346
2347 expires = rt->dst.expires;
2348 if (expires) {
2349 unsigned long now = jiffies;
2350
2351 if (time_before(now, expires))
2352 expires -= now;
2353 else
2354 expires = 0;
2355 }
2356
2357 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2358 if (rt->rt_pmtu && expires)
2359 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2360 if (rtnetlink_put_metrics(skb, metrics) < 0)
2361 goto nla_put_failure;
2362
2363 if (fl4->flowi4_mark &&
2364 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2365 goto nla_put_failure;
2366
2367 error = rt->dst.error;
2368
2369 if (rt_is_input_route(rt)) {
2370 #ifdef CONFIG_IP_MROUTE
2371 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2372 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2373 int err = ipmr_get_route(net, skb,
2374 fl4->saddr, fl4->daddr,
2375 r, nowait);
2376 if (err <= 0) {
2377 if (!nowait) {
2378 if (err == 0)
2379 return 0;
2380 goto nla_put_failure;
2381 } else {
2382 if (err == -EMSGSIZE)
2383 goto nla_put_failure;
2384 error = err;
2385 }
2386 }
2387 } else
2388 #endif
2389 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2390 goto nla_put_failure;
2391 }
2392
2393 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2394 goto nla_put_failure;
2395
2396 nlmsg_end(skb, nlh);
2397 return 0;
2398
2399 nla_put_failure:
2400 nlmsg_cancel(skb, nlh);
2401 return -EMSGSIZE;
2402 }
2403
2404 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2405 {
2406 struct net *net = sock_net(in_skb->sk);
2407 struct rtmsg *rtm;
2408 struct nlattr *tb[RTA_MAX+1];
2409 struct rtable *rt = NULL;
2410 struct flowi4 fl4;
2411 __be32 dst = 0;
2412 __be32 src = 0;
2413 u32 iif;
2414 int err;
2415 int mark;
2416 struct sk_buff *skb;
2417
2418 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2419 if (err < 0)
2420 goto errout;
2421
2422 rtm = nlmsg_data(nlh);
2423
2424 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2425 if (!skb) {
2426 err = -ENOBUFS;
2427 goto errout;
2428 }
2429
2430 /* Reserve room for dummy headers, this skb can pass
2431 through good chunk of routing engine.
2432 */
2433 skb_reset_mac_header(skb);
2434 skb_reset_network_header(skb);
2435
2436 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2437 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2438 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2439
2440 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2441 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2442 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2443 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2444
2445 memset(&fl4, 0, sizeof(fl4));
2446 fl4.daddr = dst;
2447 fl4.saddr = src;
2448 fl4.flowi4_tos = rtm->rtm_tos;
2449 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2450 fl4.flowi4_mark = mark;
2451
2452 if (iif) {
2453 struct net_device *dev;
2454
2455 dev = __dev_get_by_index(net, iif);
2456 if (!dev) {
2457 err = -ENODEV;
2458 goto errout_free;
2459 }
2460
2461 skb->protocol = htons(ETH_P_IP);
2462 skb->dev = dev;
2463 skb->mark = mark;
2464 local_bh_disable();
2465 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2466 local_bh_enable();
2467
2468 rt = skb_rtable(skb);
2469 if (err == 0 && rt->dst.error)
2470 err = -rt->dst.error;
2471 } else {
2472 rt = ip_route_output_key(net, &fl4);
2473
2474 err = 0;
2475 if (IS_ERR(rt))
2476 err = PTR_ERR(rt);
2477 }
2478
2479 if (err)
2480 goto errout_free;
2481
2482 skb_dst_set(skb, &rt->dst);
2483 if (rtm->rtm_flags & RTM_F_NOTIFY)
2484 rt->rt_flags |= RTCF_NOTIFY;
2485
2486 err = rt_fill_info(net, dst, src, &fl4, skb,
2487 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2488 RTM_NEWROUTE, 0, 0);
2489 if (err < 0)
2490 goto errout_free;
2491
2492 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2493 errout:
2494 return err;
2495
2496 errout_free:
2497 kfree_skb(skb);
2498 goto errout;
2499 }
2500
2501 void ip_rt_multicast_event(struct in_device *in_dev)
2502 {
2503 rt_cache_flush(dev_net(in_dev->dev));
2504 }
2505
2506 #ifdef CONFIG_SYSCTL
2507 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2508 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2509 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2510 static int ip_rt_gc_elasticity __read_mostly = 8;
2511
2512 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2513 void __user *buffer,
2514 size_t *lenp, loff_t *ppos)
2515 {
2516 struct net *net = (struct net *)__ctl->extra1;
2517
2518 if (write) {
2519 rt_cache_flush(net);
2520 fnhe_genid_bump(net);
2521 return 0;
2522 }
2523
2524 return -EINVAL;
2525 }
2526
2527 static struct ctl_table ipv4_route_table[] = {
2528 {
2529 .procname = "gc_thresh",
2530 .data = &ipv4_dst_ops.gc_thresh,
2531 .maxlen = sizeof(int),
2532 .mode = 0644,
2533 .proc_handler = proc_dointvec,
2534 },
2535 {
2536 .procname = "max_size",
2537 .data = &ip_rt_max_size,
2538 .maxlen = sizeof(int),
2539 .mode = 0644,
2540 .proc_handler = proc_dointvec,
2541 },
2542 {
2543 /* Deprecated. Use gc_min_interval_ms */
2544
2545 .procname = "gc_min_interval",
2546 .data = &ip_rt_gc_min_interval,
2547 .maxlen = sizeof(int),
2548 .mode = 0644,
2549 .proc_handler = proc_dointvec_jiffies,
2550 },
2551 {
2552 .procname = "gc_min_interval_ms",
2553 .data = &ip_rt_gc_min_interval,
2554 .maxlen = sizeof(int),
2555 .mode = 0644,
2556 .proc_handler = proc_dointvec_ms_jiffies,
2557 },
2558 {
2559 .procname = "gc_timeout",
2560 .data = &ip_rt_gc_timeout,
2561 .maxlen = sizeof(int),
2562 .mode = 0644,
2563 .proc_handler = proc_dointvec_jiffies,
2564 },
2565 {
2566 .procname = "gc_interval",
2567 .data = &ip_rt_gc_interval,
2568 .maxlen = sizeof(int),
2569 .mode = 0644,
2570 .proc_handler = proc_dointvec_jiffies,
2571 },
2572 {
2573 .procname = "redirect_load",
2574 .data = &ip_rt_redirect_load,
2575 .maxlen = sizeof(int),
2576 .mode = 0644,
2577 .proc_handler = proc_dointvec,
2578 },
2579 {
2580 .procname = "redirect_number",
2581 .data = &ip_rt_redirect_number,
2582 .maxlen = sizeof(int),
2583 .mode = 0644,
2584 .proc_handler = proc_dointvec,
2585 },
2586 {
2587 .procname = "redirect_silence",
2588 .data = &ip_rt_redirect_silence,
2589 .maxlen = sizeof(int),
2590 .mode = 0644,
2591 .proc_handler = proc_dointvec,
2592 },
2593 {
2594 .procname = "error_cost",
2595 .data = &ip_rt_error_cost,
2596 .maxlen = sizeof(int),
2597 .mode = 0644,
2598 .proc_handler = proc_dointvec,
2599 },
2600 {
2601 .procname = "error_burst",
2602 .data = &ip_rt_error_burst,
2603 .maxlen = sizeof(int),
2604 .mode = 0644,
2605 .proc_handler = proc_dointvec,
2606 },
2607 {
2608 .procname = "gc_elasticity",
2609 .data = &ip_rt_gc_elasticity,
2610 .maxlen = sizeof(int),
2611 .mode = 0644,
2612 .proc_handler = proc_dointvec,
2613 },
2614 {
2615 .procname = "mtu_expires",
2616 .data = &ip_rt_mtu_expires,
2617 .maxlen = sizeof(int),
2618 .mode = 0644,
2619 .proc_handler = proc_dointvec_jiffies,
2620 },
2621 {
2622 .procname = "min_pmtu",
2623 .data = &ip_rt_min_pmtu,
2624 .maxlen = sizeof(int),
2625 .mode = 0644,
2626 .proc_handler = proc_dointvec,
2627 },
2628 {
2629 .procname = "min_adv_mss",
2630 .data = &ip_rt_min_advmss,
2631 .maxlen = sizeof(int),
2632 .mode = 0644,
2633 .proc_handler = proc_dointvec,
2634 },
2635 { }
2636 };
2637
2638 static struct ctl_table ipv4_route_flush_table[] = {
2639 {
2640 .procname = "flush",
2641 .maxlen = sizeof(int),
2642 .mode = 0200,
2643 .proc_handler = ipv4_sysctl_rtcache_flush,
2644 },
2645 { },
2646 };
2647
2648 static __net_init int sysctl_route_net_init(struct net *net)
2649 {
2650 struct ctl_table *tbl;
2651
2652 tbl = ipv4_route_flush_table;
2653 if (!net_eq(net, &init_net)) {
2654 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2655 if (!tbl)
2656 goto err_dup;
2657
2658 /* Don't export sysctls to unprivileged users */
2659 if (net->user_ns != &init_user_ns)
2660 tbl[0].procname = NULL;
2661 }
2662 tbl[0].extra1 = net;
2663
2664 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2665 if (!net->ipv4.route_hdr)
2666 goto err_reg;
2667 return 0;
2668
2669 err_reg:
2670 if (tbl != ipv4_route_flush_table)
2671 kfree(tbl);
2672 err_dup:
2673 return -ENOMEM;
2674 }
2675
2676 static __net_exit void sysctl_route_net_exit(struct net *net)
2677 {
2678 struct ctl_table *tbl;
2679
2680 tbl = net->ipv4.route_hdr->ctl_table_arg;
2681 unregister_net_sysctl_table(net->ipv4.route_hdr);
2682 BUG_ON(tbl == ipv4_route_flush_table);
2683 kfree(tbl);
2684 }
2685
2686 static __net_initdata struct pernet_operations sysctl_route_ops = {
2687 .init = sysctl_route_net_init,
2688 .exit = sysctl_route_net_exit,
2689 };
2690 #endif
2691
2692 static __net_init int rt_genid_init(struct net *net)
2693 {
2694 atomic_set(&net->ipv4.rt_genid, 0);
2695 atomic_set(&net->fnhe_genid, 0);
2696 get_random_bytes(&net->ipv4.dev_addr_genid,
2697 sizeof(net->ipv4.dev_addr_genid));
2698 return 0;
2699 }
2700
2701 static __net_initdata struct pernet_operations rt_genid_ops = {
2702 .init = rt_genid_init,
2703 };
2704
2705 static int __net_init ipv4_inetpeer_init(struct net *net)
2706 {
2707 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2708
2709 if (!bp)
2710 return -ENOMEM;
2711 inet_peer_base_init(bp);
2712 net->ipv4.peers = bp;
2713 return 0;
2714 }
2715
2716 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2717 {
2718 struct inet_peer_base *bp = net->ipv4.peers;
2719
2720 net->ipv4.peers = NULL;
2721 inetpeer_invalidate_tree(bp);
2722 kfree(bp);
2723 }
2724
2725 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2726 .init = ipv4_inetpeer_init,
2727 .exit = ipv4_inetpeer_exit,
2728 };
2729
2730 #ifdef CONFIG_IP_ROUTE_CLASSID
2731 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2732 #endif /* CONFIG_IP_ROUTE_CLASSID */
2733
2734 int __init ip_rt_init(void)
2735 {
2736 int rc = 0;
2737 int cpu;
2738
2739 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2740 if (!ip_idents)
2741 panic("IP: failed to allocate ip_idents\n");
2742
2743 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2744
2745 for_each_possible_cpu(cpu) {
2746 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
2747
2748 INIT_LIST_HEAD(&ul->head);
2749 spin_lock_init(&ul->lock);
2750 }
2751 #ifdef CONFIG_IP_ROUTE_CLASSID
2752 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2753 if (!ip_rt_acct)
2754 panic("IP: failed to allocate ip_rt_acct\n");
2755 #endif
2756
2757 ipv4_dst_ops.kmem_cachep =
2758 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2759 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2760
2761 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2762
2763 if (dst_entries_init(&ipv4_dst_ops) < 0)
2764 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2765
2766 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2767 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2768
2769 ipv4_dst_ops.gc_thresh = ~0;
2770 ip_rt_max_size = INT_MAX;
2771
2772 devinet_init();
2773 ip_fib_init();
2774
2775 if (ip_rt_proc_init())
2776 pr_err("Unable to create route proc files\n");
2777 #ifdef CONFIG_XFRM
2778 xfrm_init();
2779 xfrm4_init();
2780 #endif
2781 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2782
2783 #ifdef CONFIG_SYSCTL
2784 register_pernet_subsys(&sysctl_route_ops);
2785 #endif
2786 register_pernet_subsys(&rt_genid_ops);
2787 register_pernet_subsys(&ipv4_inetpeer_ops);
2788 return rc;
2789 }
2790
2791 #ifdef CONFIG_SYSCTL
2792 /*
2793 * We really need to sanitize the damn ipv4 init order, then all
2794 * this nonsense will go away.
2795 */
2796 void __init ip_static_sysctl_init(void)
2797 {
2798 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2799 }
2800 #endif
Linux kernel - Deliverables
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