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Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[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/vrf.h>
116
117 #define RT_FL_TOS(oldflp4) \
118 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
119
120 #define RT_GC_TIMEOUT (300*HZ)
121
122 static int ip_rt_max_size;
123 static int ip_rt_redirect_number __read_mostly = 9;
124 static int ip_rt_redirect_load __read_mostly = HZ / 50;
125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly = HZ;
127 static int ip_rt_error_burst __read_mostly = 5 * HZ;
128 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
129 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
130 static int ip_rt_min_advmss __read_mostly = 256;
131
132 /*
133 * Interface to generic destination cache.
134 */
135
136 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
137 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
138 static unsigned int ipv4_mtu(const struct dst_entry *dst);
139 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
140 static void ipv4_link_failure(struct sk_buff *skb);
141 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
142 struct sk_buff *skb, u32 mtu);
143 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
144 struct sk_buff *skb);
145 static void ipv4_dst_destroy(struct dst_entry *dst);
146
147 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
148 {
149 WARN_ON(1);
150 return NULL;
151 }
152
153 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
154 struct sk_buff *skb,
155 const void *daddr);
156
157 static struct dst_ops ipv4_dst_ops = {
158 .family = AF_INET,
159 .check = ipv4_dst_check,
160 .default_advmss = ipv4_default_advmss,
161 .mtu = ipv4_mtu,
162 .cow_metrics = ipv4_cow_metrics,
163 .destroy = ipv4_dst_destroy,
164 .negative_advice = ipv4_negative_advice,
165 .link_failure = ipv4_link_failure,
166 .update_pmtu = ip_rt_update_pmtu,
167 .redirect = ip_do_redirect,
168 .local_out = __ip_local_out,
169 .neigh_lookup = ipv4_neigh_lookup,
170 };
171
172 #define ECN_OR_COST(class) TC_PRIO_##class
173
174 const __u8 ip_tos2prio[16] = {
175 TC_PRIO_BESTEFFORT,
176 ECN_OR_COST(BESTEFFORT),
177 TC_PRIO_BESTEFFORT,
178 ECN_OR_COST(BESTEFFORT),
179 TC_PRIO_BULK,
180 ECN_OR_COST(BULK),
181 TC_PRIO_BULK,
182 ECN_OR_COST(BULK),
183 TC_PRIO_INTERACTIVE,
184 ECN_OR_COST(INTERACTIVE),
185 TC_PRIO_INTERACTIVE,
186 ECN_OR_COST(INTERACTIVE),
187 TC_PRIO_INTERACTIVE_BULK,
188 ECN_OR_COST(INTERACTIVE_BULK),
189 TC_PRIO_INTERACTIVE_BULK,
190 ECN_OR_COST(INTERACTIVE_BULK)
191 };
192 EXPORT_SYMBOL(ip_tos2prio);
193
194 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
195 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
196
197 #ifdef CONFIG_PROC_FS
198 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
199 {
200 if (*pos)
201 return NULL;
202 return SEQ_START_TOKEN;
203 }
204
205 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
206 {
207 ++*pos;
208 return NULL;
209 }
210
211 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
212 {
213 }
214
215 static int rt_cache_seq_show(struct seq_file *seq, void *v)
216 {
217 if (v == SEQ_START_TOKEN)
218 seq_printf(seq, "%-127s\n",
219 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
220 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
221 "HHUptod\tSpecDst");
222 return 0;
223 }
224
225 static const struct seq_operations rt_cache_seq_ops = {
226 .start = rt_cache_seq_start,
227 .next = rt_cache_seq_next,
228 .stop = rt_cache_seq_stop,
229 .show = rt_cache_seq_show,
230 };
231
232 static int rt_cache_seq_open(struct inode *inode, struct file *file)
233 {
234 return seq_open(file, &rt_cache_seq_ops);
235 }
236
237 static const struct file_operations rt_cache_seq_fops = {
238 .owner = THIS_MODULE,
239 .open = rt_cache_seq_open,
240 .read = seq_read,
241 .llseek = seq_lseek,
242 .release = seq_release,
243 };
244
245
246 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
247 {
248 int cpu;
249
250 if (*pos == 0)
251 return SEQ_START_TOKEN;
252
253 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
254 if (!cpu_possible(cpu))
255 continue;
256 *pos = cpu+1;
257 return &per_cpu(rt_cache_stat, cpu);
258 }
259 return NULL;
260 }
261
262 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
263 {
264 int cpu;
265
266 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
267 if (!cpu_possible(cpu))
268 continue;
269 *pos = cpu+1;
270 return &per_cpu(rt_cache_stat, cpu);
271 }
272 return NULL;
273
274 }
275
276 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
277 {
278
279 }
280
281 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
282 {
283 struct rt_cache_stat *st = v;
284
285 if (v == SEQ_START_TOKEN) {
286 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
287 return 0;
288 }
289
290 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
291 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
292 dst_entries_get_slow(&ipv4_dst_ops),
293 0, /* st->in_hit */
294 st->in_slow_tot,
295 st->in_slow_mc,
296 st->in_no_route,
297 st->in_brd,
298 st->in_martian_dst,
299 st->in_martian_src,
300
301 0, /* st->out_hit */
302 st->out_slow_tot,
303 st->out_slow_mc,
304
305 0, /* st->gc_total */
306 0, /* st->gc_ignored */
307 0, /* st->gc_goal_miss */
308 0, /* st->gc_dst_overflow */
309 0, /* st->in_hlist_search */
310 0 /* st->out_hlist_search */
311 );
312 return 0;
313 }
314
315 static const struct seq_operations rt_cpu_seq_ops = {
316 .start = rt_cpu_seq_start,
317 .next = rt_cpu_seq_next,
318 .stop = rt_cpu_seq_stop,
319 .show = rt_cpu_seq_show,
320 };
321
322
323 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
324 {
325 return seq_open(file, &rt_cpu_seq_ops);
326 }
327
328 static const struct file_operations rt_cpu_seq_fops = {
329 .owner = THIS_MODULE,
330 .open = rt_cpu_seq_open,
331 .read = seq_read,
332 .llseek = seq_lseek,
333 .release = seq_release,
334 };
335
336 #ifdef CONFIG_IP_ROUTE_CLASSID
337 static int rt_acct_proc_show(struct seq_file *m, void *v)
338 {
339 struct ip_rt_acct *dst, *src;
340 unsigned int i, j;
341
342 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
343 if (!dst)
344 return -ENOMEM;
345
346 for_each_possible_cpu(i) {
347 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
348 for (j = 0; j < 256; j++) {
349 dst[j].o_bytes += src[j].o_bytes;
350 dst[j].o_packets += src[j].o_packets;
351 dst[j].i_bytes += src[j].i_bytes;
352 dst[j].i_packets += src[j].i_packets;
353 }
354 }
355
356 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
357 kfree(dst);
358 return 0;
359 }
360
361 static int rt_acct_proc_open(struct inode *inode, struct file *file)
362 {
363 return single_open(file, rt_acct_proc_show, NULL);
364 }
365
366 static const struct file_operations rt_acct_proc_fops = {
367 .owner = THIS_MODULE,
368 .open = rt_acct_proc_open,
369 .read = seq_read,
370 .llseek = seq_lseek,
371 .release = single_release,
372 };
373 #endif
374
375 static int __net_init ip_rt_do_proc_init(struct net *net)
376 {
377 struct proc_dir_entry *pde;
378
379 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
380 &rt_cache_seq_fops);
381 if (!pde)
382 goto err1;
383
384 pde = proc_create("rt_cache", S_IRUGO,
385 net->proc_net_stat, &rt_cpu_seq_fops);
386 if (!pde)
387 goto err2;
388
389 #ifdef CONFIG_IP_ROUTE_CLASSID
390 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
391 if (!pde)
392 goto err3;
393 #endif
394 return 0;
395
396 #ifdef CONFIG_IP_ROUTE_CLASSID
397 err3:
398 remove_proc_entry("rt_cache", net->proc_net_stat);
399 #endif
400 err2:
401 remove_proc_entry("rt_cache", net->proc_net);
402 err1:
403 return -ENOMEM;
404 }
405
406 static void __net_exit ip_rt_do_proc_exit(struct net *net)
407 {
408 remove_proc_entry("rt_cache", net->proc_net_stat);
409 remove_proc_entry("rt_cache", net->proc_net);
410 #ifdef CONFIG_IP_ROUTE_CLASSID
411 remove_proc_entry("rt_acct", net->proc_net);
412 #endif
413 }
414
415 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
416 .init = ip_rt_do_proc_init,
417 .exit = ip_rt_do_proc_exit,
418 };
419
420 static int __init ip_rt_proc_init(void)
421 {
422 return register_pernet_subsys(&ip_rt_proc_ops);
423 }
424
425 #else
426 static inline int ip_rt_proc_init(void)
427 {
428 return 0;
429 }
430 #endif /* CONFIG_PROC_FS */
431
432 static inline bool rt_is_expired(const struct rtable *rth)
433 {
434 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
435 }
436
437 void rt_cache_flush(struct net *net)
438 {
439 rt_genid_bump_ipv4(net);
440 }
441
442 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
443 struct sk_buff *skb,
444 const void *daddr)
445 {
446 struct net_device *dev = dst->dev;
447 const __be32 *pkey = daddr;
448 const struct rtable *rt;
449 struct neighbour *n;
450
451 rt = (const struct rtable *) dst;
452 if (rt->rt_gateway)
453 pkey = (const __be32 *) &rt->rt_gateway;
454 else if (skb)
455 pkey = &ip_hdr(skb)->daddr;
456
457 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
458 if (n)
459 return n;
460 return neigh_create(&arp_tbl, pkey, dev);
461 }
462
463 #define IP_IDENTS_SZ 2048u
464
465 static atomic_t *ip_idents __read_mostly;
466 static u32 *ip_tstamps __read_mostly;
467
468 /* In order to protect privacy, we add a perturbation to identifiers
469 * if one generator is seldom used. This makes hard for an attacker
470 * to infer how many packets were sent between two points in time.
471 */
472 u32 ip_idents_reserve(u32 hash, int segs)
473 {
474 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
475 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
476 u32 old = ACCESS_ONCE(*p_tstamp);
477 u32 now = (u32)jiffies;
478 u32 delta = 0;
479
480 if (old != now && cmpxchg(p_tstamp, old, now) == old)
481 delta = prandom_u32_max(now - old);
482
483 return atomic_add_return(segs + delta, p_id) - segs;
484 }
485 EXPORT_SYMBOL(ip_idents_reserve);
486
487 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
488 {
489 static u32 ip_idents_hashrnd __read_mostly;
490 u32 hash, id;
491
492 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
493
494 hash = jhash_3words((__force u32)iph->daddr,
495 (__force u32)iph->saddr,
496 iph->protocol ^ net_hash_mix(net),
497 ip_idents_hashrnd);
498 id = ip_idents_reserve(hash, segs);
499 iph->id = htons(id);
500 }
501 EXPORT_SYMBOL(__ip_select_ident);
502
503 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
504 const struct iphdr *iph,
505 int oif, u8 tos,
506 u8 prot, u32 mark, int flow_flags)
507 {
508 if (sk) {
509 const struct inet_sock *inet = inet_sk(sk);
510
511 oif = sk->sk_bound_dev_if;
512 mark = sk->sk_mark;
513 tos = RT_CONN_FLAGS(sk);
514 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
515 }
516 flowi4_init_output(fl4, oif, mark, tos,
517 RT_SCOPE_UNIVERSE, prot,
518 flow_flags,
519 iph->daddr, iph->saddr, 0, 0);
520 }
521
522 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
523 const struct sock *sk)
524 {
525 const struct iphdr *iph = ip_hdr(skb);
526 int oif = skb->dev->ifindex;
527 u8 tos = RT_TOS(iph->tos);
528 u8 prot = iph->protocol;
529 u32 mark = skb->mark;
530
531 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
532 }
533
534 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
535 {
536 const struct inet_sock *inet = inet_sk(sk);
537 const struct ip_options_rcu *inet_opt;
538 __be32 daddr = inet->inet_daddr;
539
540 rcu_read_lock();
541 inet_opt = rcu_dereference(inet->inet_opt);
542 if (inet_opt && inet_opt->opt.srr)
543 daddr = inet_opt->opt.faddr;
544 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
545 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
546 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
547 inet_sk_flowi_flags(sk),
548 daddr, inet->inet_saddr, 0, 0);
549 rcu_read_unlock();
550 }
551
552 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
553 const struct sk_buff *skb)
554 {
555 if (skb)
556 build_skb_flow_key(fl4, skb, sk);
557 else
558 build_sk_flow_key(fl4, sk);
559 }
560
561 static inline void rt_free(struct rtable *rt)
562 {
563 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
564 }
565
566 static DEFINE_SPINLOCK(fnhe_lock);
567
568 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
569 {
570 struct rtable *rt;
571
572 rt = rcu_dereference(fnhe->fnhe_rth_input);
573 if (rt) {
574 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
575 rt_free(rt);
576 }
577 rt = rcu_dereference(fnhe->fnhe_rth_output);
578 if (rt) {
579 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
580 rt_free(rt);
581 }
582 }
583
584 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
585 {
586 struct fib_nh_exception *fnhe, *oldest;
587
588 oldest = rcu_dereference(hash->chain);
589 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
590 fnhe = rcu_dereference(fnhe->fnhe_next)) {
591 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
592 oldest = fnhe;
593 }
594 fnhe_flush_routes(oldest);
595 return oldest;
596 }
597
598 static inline u32 fnhe_hashfun(__be32 daddr)
599 {
600 static u32 fnhe_hashrnd __read_mostly;
601 u32 hval;
602
603 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
604 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
605 return hash_32(hval, FNHE_HASH_SHIFT);
606 }
607
608 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
609 {
610 rt->rt_pmtu = fnhe->fnhe_pmtu;
611 rt->dst.expires = fnhe->fnhe_expires;
612
613 if (fnhe->fnhe_gw) {
614 rt->rt_flags |= RTCF_REDIRECTED;
615 rt->rt_gateway = fnhe->fnhe_gw;
616 rt->rt_uses_gateway = 1;
617 }
618 }
619
620 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
621 u32 pmtu, unsigned long expires)
622 {
623 struct fnhe_hash_bucket *hash;
624 struct fib_nh_exception *fnhe;
625 struct rtable *rt;
626 unsigned int i;
627 int depth;
628 u32 hval = fnhe_hashfun(daddr);
629
630 spin_lock_bh(&fnhe_lock);
631
632 hash = rcu_dereference(nh->nh_exceptions);
633 if (!hash) {
634 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
635 if (!hash)
636 goto out_unlock;
637 rcu_assign_pointer(nh->nh_exceptions, hash);
638 }
639
640 hash += hval;
641
642 depth = 0;
643 for (fnhe = rcu_dereference(hash->chain); fnhe;
644 fnhe = rcu_dereference(fnhe->fnhe_next)) {
645 if (fnhe->fnhe_daddr == daddr)
646 break;
647 depth++;
648 }
649
650 if (fnhe) {
651 if (gw)
652 fnhe->fnhe_gw = gw;
653 if (pmtu) {
654 fnhe->fnhe_pmtu = pmtu;
655 fnhe->fnhe_expires = max(1UL, expires);
656 }
657 /* Update all cached dsts too */
658 rt = rcu_dereference(fnhe->fnhe_rth_input);
659 if (rt)
660 fill_route_from_fnhe(rt, fnhe);
661 rt = rcu_dereference(fnhe->fnhe_rth_output);
662 if (rt)
663 fill_route_from_fnhe(rt, fnhe);
664 } else {
665 if (depth > FNHE_RECLAIM_DEPTH)
666 fnhe = fnhe_oldest(hash);
667 else {
668 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
669 if (!fnhe)
670 goto out_unlock;
671
672 fnhe->fnhe_next = hash->chain;
673 rcu_assign_pointer(hash->chain, fnhe);
674 }
675 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
676 fnhe->fnhe_daddr = daddr;
677 fnhe->fnhe_gw = gw;
678 fnhe->fnhe_pmtu = pmtu;
679 fnhe->fnhe_expires = expires;
680
681 /* Exception created; mark the cached routes for the nexthop
682 * stale, so anyone caching it rechecks if this exception
683 * applies to them.
684 */
685 rt = rcu_dereference(nh->nh_rth_input);
686 if (rt)
687 rt->dst.obsolete = DST_OBSOLETE_KILL;
688
689 for_each_possible_cpu(i) {
690 struct rtable __rcu **prt;
691 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
692 rt = rcu_dereference(*prt);
693 if (rt)
694 rt->dst.obsolete = DST_OBSOLETE_KILL;
695 }
696 }
697
698 fnhe->fnhe_stamp = jiffies;
699
700 out_unlock:
701 spin_unlock_bh(&fnhe_lock);
702 }
703
704 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
705 bool kill_route)
706 {
707 __be32 new_gw = icmp_hdr(skb)->un.gateway;
708 __be32 old_gw = ip_hdr(skb)->saddr;
709 struct net_device *dev = skb->dev;
710 struct in_device *in_dev;
711 struct fib_result res;
712 struct neighbour *n;
713 struct net *net;
714
715 switch (icmp_hdr(skb)->code & 7) {
716 case ICMP_REDIR_NET:
717 case ICMP_REDIR_NETTOS:
718 case ICMP_REDIR_HOST:
719 case ICMP_REDIR_HOSTTOS:
720 break;
721
722 default:
723 return;
724 }
725
726 if (rt->rt_gateway != old_gw)
727 return;
728
729 in_dev = __in_dev_get_rcu(dev);
730 if (!in_dev)
731 return;
732
733 net = dev_net(dev);
734 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
735 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
736 ipv4_is_zeronet(new_gw))
737 goto reject_redirect;
738
739 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
740 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
741 goto reject_redirect;
742 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
743 goto reject_redirect;
744 } else {
745 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
746 goto reject_redirect;
747 }
748
749 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
750 if (!IS_ERR(n)) {
751 if (!(n->nud_state & NUD_VALID)) {
752 neigh_event_send(n, NULL);
753 } else {
754 if (fib_lookup(net, fl4, &res, 0) == 0) {
755 struct fib_nh *nh = &FIB_RES_NH(res);
756
757 update_or_create_fnhe(nh, fl4->daddr, new_gw,
758 0, 0);
759 }
760 if (kill_route)
761 rt->dst.obsolete = DST_OBSOLETE_KILL;
762 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
763 }
764 neigh_release(n);
765 }
766 return;
767
768 reject_redirect:
769 #ifdef CONFIG_IP_ROUTE_VERBOSE
770 if (IN_DEV_LOG_MARTIANS(in_dev)) {
771 const struct iphdr *iph = (const struct iphdr *) skb->data;
772 __be32 daddr = iph->daddr;
773 __be32 saddr = iph->saddr;
774
775 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
776 " Advised path = %pI4 -> %pI4\n",
777 &old_gw, dev->name, &new_gw,
778 &saddr, &daddr);
779 }
780 #endif
781 ;
782 }
783
784 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
785 {
786 struct rtable *rt;
787 struct flowi4 fl4;
788 const struct iphdr *iph = (const struct iphdr *) skb->data;
789 int oif = skb->dev->ifindex;
790 u8 tos = RT_TOS(iph->tos);
791 u8 prot = iph->protocol;
792 u32 mark = skb->mark;
793
794 rt = (struct rtable *) dst;
795
796 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
797 __ip_do_redirect(rt, skb, &fl4, true);
798 }
799
800 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
801 {
802 struct rtable *rt = (struct rtable *)dst;
803 struct dst_entry *ret = dst;
804
805 if (rt) {
806 if (dst->obsolete > 0) {
807 ip_rt_put(rt);
808 ret = NULL;
809 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
810 rt->dst.expires) {
811 ip_rt_put(rt);
812 ret = NULL;
813 }
814 }
815 return ret;
816 }
817
818 /*
819 * Algorithm:
820 * 1. The first ip_rt_redirect_number redirects are sent
821 * with exponential backoff, then we stop sending them at all,
822 * assuming that the host ignores our redirects.
823 * 2. If we did not see packets requiring redirects
824 * during ip_rt_redirect_silence, we assume that the host
825 * forgot redirected route and start to send redirects again.
826 *
827 * This algorithm is much cheaper and more intelligent than dumb load limiting
828 * in icmp.c.
829 *
830 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
831 * and "frag. need" (breaks PMTU discovery) in icmp.c.
832 */
833
834 void ip_rt_send_redirect(struct sk_buff *skb)
835 {
836 struct rtable *rt = skb_rtable(skb);
837 struct in_device *in_dev;
838 struct inet_peer *peer;
839 struct net *net;
840 int log_martians;
841 int vif;
842
843 rcu_read_lock();
844 in_dev = __in_dev_get_rcu(rt->dst.dev);
845 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
846 rcu_read_unlock();
847 return;
848 }
849 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
850 vif = vrf_master_ifindex_rcu(rt->dst.dev);
851 rcu_read_unlock();
852
853 net = dev_net(rt->dst.dev);
854 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
855 if (!peer) {
856 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
857 rt_nexthop(rt, ip_hdr(skb)->daddr));
858 return;
859 }
860
861 /* No redirected packets during ip_rt_redirect_silence;
862 * reset the algorithm.
863 */
864 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
865 peer->rate_tokens = 0;
866
867 /* Too many ignored redirects; do not send anything
868 * set dst.rate_last to the last seen redirected packet.
869 */
870 if (peer->rate_tokens >= ip_rt_redirect_number) {
871 peer->rate_last = jiffies;
872 goto out_put_peer;
873 }
874
875 /* Check for load limit; set rate_last to the latest sent
876 * redirect.
877 */
878 if (peer->rate_tokens == 0 ||
879 time_after(jiffies,
880 (peer->rate_last +
881 (ip_rt_redirect_load << peer->rate_tokens)))) {
882 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
883
884 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
885 peer->rate_last = jiffies;
886 ++peer->rate_tokens;
887 #ifdef CONFIG_IP_ROUTE_VERBOSE
888 if (log_martians &&
889 peer->rate_tokens == ip_rt_redirect_number)
890 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
891 &ip_hdr(skb)->saddr, inet_iif(skb),
892 &ip_hdr(skb)->daddr, &gw);
893 #endif
894 }
895 out_put_peer:
896 inet_putpeer(peer);
897 }
898
899 static int ip_error(struct sk_buff *skb)
900 {
901 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
902 struct rtable *rt = skb_rtable(skb);
903 struct inet_peer *peer;
904 unsigned long now;
905 struct net *net;
906 bool send;
907 int code;
908
909 /* IP on this device is disabled. */
910 if (!in_dev)
911 goto out;
912
913 net = dev_net(rt->dst.dev);
914 if (!IN_DEV_FORWARD(in_dev)) {
915 switch (rt->dst.error) {
916 case EHOSTUNREACH:
917 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
918 break;
919
920 case ENETUNREACH:
921 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
922 break;
923 }
924 goto out;
925 }
926
927 switch (rt->dst.error) {
928 case EINVAL:
929 default:
930 goto out;
931 case EHOSTUNREACH:
932 code = ICMP_HOST_UNREACH;
933 break;
934 case ENETUNREACH:
935 code = ICMP_NET_UNREACH;
936 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
937 break;
938 case EACCES:
939 code = ICMP_PKT_FILTERED;
940 break;
941 }
942
943 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
944 vrf_master_ifindex(skb->dev), 1);
945
946 send = true;
947 if (peer) {
948 now = jiffies;
949 peer->rate_tokens += now - peer->rate_last;
950 if (peer->rate_tokens > ip_rt_error_burst)
951 peer->rate_tokens = ip_rt_error_burst;
952 peer->rate_last = now;
953 if (peer->rate_tokens >= ip_rt_error_cost)
954 peer->rate_tokens -= ip_rt_error_cost;
955 else
956 send = false;
957 inet_putpeer(peer);
958 }
959 if (send)
960 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
961
962 out: kfree_skb(skb);
963 return 0;
964 }
965
966 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
967 {
968 struct dst_entry *dst = &rt->dst;
969 struct fib_result res;
970
971 if (dst_metric_locked(dst, RTAX_MTU))
972 return;
973
974 if (ipv4_mtu(dst) < mtu)
975 return;
976
977 if (mtu < ip_rt_min_pmtu)
978 mtu = ip_rt_min_pmtu;
979
980 if (rt->rt_pmtu == mtu &&
981 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
982 return;
983
984 rcu_read_lock();
985 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
986 struct fib_nh *nh = &FIB_RES_NH(res);
987
988 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
989 jiffies + ip_rt_mtu_expires);
990 }
991 rcu_read_unlock();
992 }
993
994 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
995 struct sk_buff *skb, u32 mtu)
996 {
997 struct rtable *rt = (struct rtable *) dst;
998 struct flowi4 fl4;
999
1000 ip_rt_build_flow_key(&fl4, sk, skb);
1001 __ip_rt_update_pmtu(rt, &fl4, mtu);
1002 }
1003
1004 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1005 int oif, u32 mark, u8 protocol, int flow_flags)
1006 {
1007 const struct iphdr *iph = (const struct iphdr *) skb->data;
1008 struct flowi4 fl4;
1009 struct rtable *rt;
1010
1011 if (!mark)
1012 mark = IP4_REPLY_MARK(net, skb->mark);
1013
1014 __build_flow_key(&fl4, NULL, iph, oif,
1015 RT_TOS(iph->tos), protocol, mark, flow_flags);
1016 rt = __ip_route_output_key(net, &fl4);
1017 if (!IS_ERR(rt)) {
1018 __ip_rt_update_pmtu(rt, &fl4, mtu);
1019 ip_rt_put(rt);
1020 }
1021 }
1022 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1023
1024 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1025 {
1026 const struct iphdr *iph = (const struct iphdr *) skb->data;
1027 struct flowi4 fl4;
1028 struct rtable *rt;
1029
1030 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1031
1032 if (!fl4.flowi4_mark)
1033 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1034
1035 rt = __ip_route_output_key(sock_net(sk), &fl4);
1036 if (!IS_ERR(rt)) {
1037 __ip_rt_update_pmtu(rt, &fl4, mtu);
1038 ip_rt_put(rt);
1039 }
1040 }
1041
1042 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1043 {
1044 const struct iphdr *iph = (const struct iphdr *) skb->data;
1045 struct flowi4 fl4;
1046 struct rtable *rt;
1047 struct dst_entry *odst = NULL;
1048 bool new = false;
1049
1050 bh_lock_sock(sk);
1051
1052 if (!ip_sk_accept_pmtu(sk))
1053 goto out;
1054
1055 odst = sk_dst_get(sk);
1056
1057 if (sock_owned_by_user(sk) || !odst) {
1058 __ipv4_sk_update_pmtu(skb, sk, mtu);
1059 goto out;
1060 }
1061
1062 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1063
1064 rt = (struct rtable *)odst;
1065 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1066 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1067 if (IS_ERR(rt))
1068 goto out;
1069
1070 new = true;
1071 }
1072
1073 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1074
1075 if (!dst_check(&rt->dst, 0)) {
1076 if (new)
1077 dst_release(&rt->dst);
1078
1079 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1080 if (IS_ERR(rt))
1081 goto out;
1082
1083 new = true;
1084 }
1085
1086 if (new)
1087 sk_dst_set(sk, &rt->dst);
1088
1089 out:
1090 bh_unlock_sock(sk);
1091 dst_release(odst);
1092 }
1093 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1094
1095 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1096 int oif, u32 mark, u8 protocol, int flow_flags)
1097 {
1098 const struct iphdr *iph = (const struct iphdr *) skb->data;
1099 struct flowi4 fl4;
1100 struct rtable *rt;
1101
1102 __build_flow_key(&fl4, NULL, iph, oif,
1103 RT_TOS(iph->tos), protocol, mark, flow_flags);
1104 rt = __ip_route_output_key(net, &fl4);
1105 if (!IS_ERR(rt)) {
1106 __ip_do_redirect(rt, skb, &fl4, false);
1107 ip_rt_put(rt);
1108 }
1109 }
1110 EXPORT_SYMBOL_GPL(ipv4_redirect);
1111
1112 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1113 {
1114 const struct iphdr *iph = (const struct iphdr *) skb->data;
1115 struct flowi4 fl4;
1116 struct rtable *rt;
1117
1118 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1119 rt = __ip_route_output_key(sock_net(sk), &fl4);
1120 if (!IS_ERR(rt)) {
1121 __ip_do_redirect(rt, skb, &fl4, false);
1122 ip_rt_put(rt);
1123 }
1124 }
1125 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1126
1127 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1128 {
1129 struct rtable *rt = (struct rtable *) dst;
1130
1131 /* All IPV4 dsts are created with ->obsolete set to the value
1132 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1133 * into this function always.
1134 *
1135 * When a PMTU/redirect information update invalidates a route,
1136 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1137 * DST_OBSOLETE_DEAD by dst_free().
1138 */
1139 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1140 return NULL;
1141 return dst;
1142 }
1143
1144 static void ipv4_link_failure(struct sk_buff *skb)
1145 {
1146 struct rtable *rt;
1147
1148 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1149
1150 rt = skb_rtable(skb);
1151 if (rt)
1152 dst_set_expires(&rt->dst, 0);
1153 }
1154
1155 static int ip_rt_bug(struct sock *sk, struct sk_buff *skb)
1156 {
1157 pr_debug("%s: %pI4 -> %pI4, %s\n",
1158 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1159 skb->dev ? skb->dev->name : "?");
1160 kfree_skb(skb);
1161 WARN_ON(1);
1162 return 0;
1163 }
1164
1165 /*
1166 We do not cache source address of outgoing interface,
1167 because it is used only by IP RR, TS and SRR options,
1168 so that it out of fast path.
1169
1170 BTW remember: "addr" is allowed to be not aligned
1171 in IP options!
1172 */
1173
1174 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1175 {
1176 __be32 src;
1177
1178 if (rt_is_output_route(rt))
1179 src = ip_hdr(skb)->saddr;
1180 else {
1181 struct fib_result res;
1182 struct flowi4 fl4;
1183 struct iphdr *iph;
1184
1185 iph = ip_hdr(skb);
1186
1187 memset(&fl4, 0, sizeof(fl4));
1188 fl4.daddr = iph->daddr;
1189 fl4.saddr = iph->saddr;
1190 fl4.flowi4_tos = RT_TOS(iph->tos);
1191 fl4.flowi4_oif = rt->dst.dev->ifindex;
1192 fl4.flowi4_iif = skb->dev->ifindex;
1193 fl4.flowi4_mark = skb->mark;
1194
1195 rcu_read_lock();
1196 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1197 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1198 else
1199 src = inet_select_addr(rt->dst.dev,
1200 rt_nexthop(rt, iph->daddr),
1201 RT_SCOPE_UNIVERSE);
1202 rcu_read_unlock();
1203 }
1204 memcpy(addr, &src, 4);
1205 }
1206
1207 #ifdef CONFIG_IP_ROUTE_CLASSID
1208 static void set_class_tag(struct rtable *rt, u32 tag)
1209 {
1210 if (!(rt->dst.tclassid & 0xFFFF))
1211 rt->dst.tclassid |= tag & 0xFFFF;
1212 if (!(rt->dst.tclassid & 0xFFFF0000))
1213 rt->dst.tclassid |= tag & 0xFFFF0000;
1214 }
1215 #endif
1216
1217 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1218 {
1219 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1220
1221 if (advmss == 0) {
1222 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1223 ip_rt_min_advmss);
1224 if (advmss > 65535 - 40)
1225 advmss = 65535 - 40;
1226 }
1227 return advmss;
1228 }
1229
1230 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1231 {
1232 const struct rtable *rt = (const struct rtable *) dst;
1233 unsigned int mtu = rt->rt_pmtu;
1234
1235 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1236 mtu = dst_metric_raw(dst, RTAX_MTU);
1237
1238 if (mtu)
1239 return mtu;
1240
1241 mtu = dst->dev->mtu;
1242
1243 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1244 if (rt->rt_uses_gateway && mtu > 576)
1245 mtu = 576;
1246 }
1247
1248 return min_t(unsigned int, mtu, IP_MAX_MTU);
1249 }
1250
1251 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1252 {
1253 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1254 struct fib_nh_exception *fnhe;
1255 u32 hval;
1256
1257 if (!hash)
1258 return NULL;
1259
1260 hval = fnhe_hashfun(daddr);
1261
1262 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1263 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1264 if (fnhe->fnhe_daddr == daddr)
1265 return fnhe;
1266 }
1267 return NULL;
1268 }
1269
1270 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1271 __be32 daddr)
1272 {
1273 bool ret = false;
1274
1275 spin_lock_bh(&fnhe_lock);
1276
1277 if (daddr == fnhe->fnhe_daddr) {
1278 struct rtable __rcu **porig;
1279 struct rtable *orig;
1280 int genid = fnhe_genid(dev_net(rt->dst.dev));
1281
1282 if (rt_is_input_route(rt))
1283 porig = &fnhe->fnhe_rth_input;
1284 else
1285 porig = &fnhe->fnhe_rth_output;
1286 orig = rcu_dereference(*porig);
1287
1288 if (fnhe->fnhe_genid != genid) {
1289 fnhe->fnhe_genid = genid;
1290 fnhe->fnhe_gw = 0;
1291 fnhe->fnhe_pmtu = 0;
1292 fnhe->fnhe_expires = 0;
1293 fnhe_flush_routes(fnhe);
1294 orig = NULL;
1295 }
1296 fill_route_from_fnhe(rt, fnhe);
1297 if (!rt->rt_gateway)
1298 rt->rt_gateway = daddr;
1299
1300 if (!(rt->dst.flags & DST_NOCACHE)) {
1301 rcu_assign_pointer(*porig, rt);
1302 if (orig)
1303 rt_free(orig);
1304 ret = true;
1305 }
1306
1307 fnhe->fnhe_stamp = jiffies;
1308 }
1309 spin_unlock_bh(&fnhe_lock);
1310
1311 return ret;
1312 }
1313
1314 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1315 {
1316 struct rtable *orig, *prev, **p;
1317 bool ret = true;
1318
1319 if (rt_is_input_route(rt)) {
1320 p = (struct rtable **)&nh->nh_rth_input;
1321 } else {
1322 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1323 }
1324 orig = *p;
1325
1326 prev = cmpxchg(p, orig, rt);
1327 if (prev == orig) {
1328 if (orig)
1329 rt_free(orig);
1330 } else
1331 ret = false;
1332
1333 return ret;
1334 }
1335
1336 struct uncached_list {
1337 spinlock_t lock;
1338 struct list_head head;
1339 };
1340
1341 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1342
1343 static void rt_add_uncached_list(struct rtable *rt)
1344 {
1345 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1346
1347 rt->rt_uncached_list = ul;
1348
1349 spin_lock_bh(&ul->lock);
1350 list_add_tail(&rt->rt_uncached, &ul->head);
1351 spin_unlock_bh(&ul->lock);
1352 }
1353
1354 static void ipv4_dst_destroy(struct dst_entry *dst)
1355 {
1356 struct rtable *rt = (struct rtable *) dst;
1357
1358 if (!list_empty(&rt->rt_uncached)) {
1359 struct uncached_list *ul = rt->rt_uncached_list;
1360
1361 spin_lock_bh(&ul->lock);
1362 list_del(&rt->rt_uncached);
1363 spin_unlock_bh(&ul->lock);
1364 }
1365 }
1366
1367 void rt_flush_dev(struct net_device *dev)
1368 {
1369 struct net *net = dev_net(dev);
1370 struct rtable *rt;
1371 int cpu;
1372
1373 for_each_possible_cpu(cpu) {
1374 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1375
1376 spin_lock_bh(&ul->lock);
1377 list_for_each_entry(rt, &ul->head, rt_uncached) {
1378 if (rt->dst.dev != dev)
1379 continue;
1380 rt->dst.dev = net->loopback_dev;
1381 dev_hold(rt->dst.dev);
1382 dev_put(dev);
1383 }
1384 spin_unlock_bh(&ul->lock);
1385 }
1386 }
1387
1388 static bool rt_cache_valid(const struct rtable *rt)
1389 {
1390 return rt &&
1391 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1392 !rt_is_expired(rt);
1393 }
1394
1395 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1396 const struct fib_result *res,
1397 struct fib_nh_exception *fnhe,
1398 struct fib_info *fi, u16 type, u32 itag)
1399 {
1400 bool cached = false;
1401
1402 if (fi) {
1403 struct fib_nh *nh = &FIB_RES_NH(*res);
1404
1405 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1406 rt->rt_gateway = nh->nh_gw;
1407 rt->rt_uses_gateway = 1;
1408 }
1409 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1410 #ifdef CONFIG_IP_ROUTE_CLASSID
1411 rt->dst.tclassid = nh->nh_tclassid;
1412 #endif
1413 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
1414 if (unlikely(fnhe))
1415 cached = rt_bind_exception(rt, fnhe, daddr);
1416 else if (!(rt->dst.flags & DST_NOCACHE))
1417 cached = rt_cache_route(nh, rt);
1418 if (unlikely(!cached)) {
1419 /* Routes we intend to cache in nexthop exception or
1420 * FIB nexthop have the DST_NOCACHE bit clear.
1421 * However, if we are unsuccessful at storing this
1422 * route into the cache we really need to set it.
1423 */
1424 rt->dst.flags |= DST_NOCACHE;
1425 if (!rt->rt_gateway)
1426 rt->rt_gateway = daddr;
1427 rt_add_uncached_list(rt);
1428 }
1429 } else
1430 rt_add_uncached_list(rt);
1431
1432 #ifdef CONFIG_IP_ROUTE_CLASSID
1433 #ifdef CONFIG_IP_MULTIPLE_TABLES
1434 set_class_tag(rt, res->tclassid);
1435 #endif
1436 set_class_tag(rt, itag);
1437 #endif
1438 }
1439
1440 static struct rtable *rt_dst_alloc(struct net_device *dev,
1441 bool nopolicy, bool noxfrm, bool will_cache)
1442 {
1443 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1444 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1445 (nopolicy ? DST_NOPOLICY : 0) |
1446 (noxfrm ? DST_NOXFRM : 0));
1447 }
1448
1449 /* called in rcu_read_lock() section */
1450 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1451 u8 tos, struct net_device *dev, int our)
1452 {
1453 struct rtable *rth;
1454 struct in_device *in_dev = __in_dev_get_rcu(dev);
1455 u32 itag = 0;
1456 int err;
1457
1458 /* Primary sanity checks. */
1459
1460 if (!in_dev)
1461 return -EINVAL;
1462
1463 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1464 skb->protocol != htons(ETH_P_IP))
1465 goto e_inval;
1466
1467 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1468 if (ipv4_is_loopback(saddr))
1469 goto e_inval;
1470
1471 if (ipv4_is_zeronet(saddr)) {
1472 if (!ipv4_is_local_multicast(daddr))
1473 goto e_inval;
1474 } else {
1475 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1476 in_dev, &itag);
1477 if (err < 0)
1478 goto e_err;
1479 }
1480 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1481 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1482 if (!rth)
1483 goto e_nobufs;
1484
1485 #ifdef CONFIG_IP_ROUTE_CLASSID
1486 rth->dst.tclassid = itag;
1487 #endif
1488 rth->dst.output = ip_rt_bug;
1489
1490 rth->rt_genid = rt_genid_ipv4(dev_net(dev));
1491 rth->rt_flags = RTCF_MULTICAST;
1492 rth->rt_type = RTN_MULTICAST;
1493 rth->rt_is_input= 1;
1494 rth->rt_iif = 0;
1495 rth->rt_pmtu = 0;
1496 rth->rt_gateway = 0;
1497 rth->rt_uses_gateway = 0;
1498 INIT_LIST_HEAD(&rth->rt_uncached);
1499 if (our) {
1500 rth->dst.input= ip_local_deliver;
1501 rth->rt_flags |= RTCF_LOCAL;
1502 }
1503
1504 #ifdef CONFIG_IP_MROUTE
1505 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1506 rth->dst.input = ip_mr_input;
1507 #endif
1508 RT_CACHE_STAT_INC(in_slow_mc);
1509
1510 skb_dst_set(skb, &rth->dst);
1511 return 0;
1512
1513 e_nobufs:
1514 return -ENOBUFS;
1515 e_inval:
1516 return -EINVAL;
1517 e_err:
1518 return err;
1519 }
1520
1521
1522 static void ip_handle_martian_source(struct net_device *dev,
1523 struct in_device *in_dev,
1524 struct sk_buff *skb,
1525 __be32 daddr,
1526 __be32 saddr)
1527 {
1528 RT_CACHE_STAT_INC(in_martian_src);
1529 #ifdef CONFIG_IP_ROUTE_VERBOSE
1530 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1531 /*
1532 * RFC1812 recommendation, if source is martian,
1533 * the only hint is MAC header.
1534 */
1535 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1536 &daddr, &saddr, dev->name);
1537 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1538 print_hex_dump(KERN_WARNING, "ll header: ",
1539 DUMP_PREFIX_OFFSET, 16, 1,
1540 skb_mac_header(skb),
1541 dev->hard_header_len, true);
1542 }
1543 }
1544 #endif
1545 }
1546
1547 /* called in rcu_read_lock() section */
1548 static int __mkroute_input(struct sk_buff *skb,
1549 const struct fib_result *res,
1550 struct in_device *in_dev,
1551 __be32 daddr, __be32 saddr, u32 tos)
1552 {
1553 struct fib_nh_exception *fnhe;
1554 struct rtable *rth;
1555 int err;
1556 struct in_device *out_dev;
1557 bool do_cache;
1558 u32 itag = 0;
1559
1560 /* get a working reference to the output device */
1561 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1562 if (!out_dev) {
1563 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1564 return -EINVAL;
1565 }
1566
1567 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1568 in_dev->dev, in_dev, &itag);
1569 if (err < 0) {
1570 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1571 saddr);
1572
1573 goto cleanup;
1574 }
1575
1576 do_cache = res->fi && !itag;
1577 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1578 skb->protocol == htons(ETH_P_IP) &&
1579 (IN_DEV_SHARED_MEDIA(out_dev) ||
1580 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1581 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1582
1583 if (skb->protocol != htons(ETH_P_IP)) {
1584 /* Not IP (i.e. ARP). Do not create route, if it is
1585 * invalid for proxy arp. DNAT routes are always valid.
1586 *
1587 * Proxy arp feature have been extended to allow, ARP
1588 * replies back to the same interface, to support
1589 * Private VLAN switch technologies. See arp.c.
1590 */
1591 if (out_dev == in_dev &&
1592 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1593 err = -EINVAL;
1594 goto cleanup;
1595 }
1596 }
1597
1598 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1599 if (do_cache) {
1600 if (fnhe)
1601 rth = rcu_dereference(fnhe->fnhe_rth_input);
1602 else
1603 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1604
1605 if (rt_cache_valid(rth)) {
1606 skb_dst_set_noref(skb, &rth->dst);
1607 goto out;
1608 }
1609 }
1610
1611 rth = rt_dst_alloc(out_dev->dev,
1612 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1613 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1614 if (!rth) {
1615 err = -ENOBUFS;
1616 goto cleanup;
1617 }
1618
1619 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev));
1620 rth->rt_flags = 0;
1621 rth->rt_type = res->type;
1622 rth->rt_is_input = 1;
1623 rth->rt_iif = 0;
1624 rth->rt_pmtu = 0;
1625 rth->rt_gateway = 0;
1626 rth->rt_uses_gateway = 0;
1627 INIT_LIST_HEAD(&rth->rt_uncached);
1628 RT_CACHE_STAT_INC(in_slow_tot);
1629
1630 rth->dst.input = ip_forward;
1631 rth->dst.output = ip_output;
1632
1633 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1634 if (lwtunnel_output_redirect(rth->dst.lwtstate)) {
1635 rth->dst.lwtstate->orig_output = rth->dst.output;
1636 rth->dst.output = lwtunnel_output;
1637 }
1638 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
1639 rth->dst.lwtstate->orig_input = rth->dst.input;
1640 rth->dst.input = lwtunnel_input;
1641 }
1642 skb_dst_set(skb, &rth->dst);
1643 out:
1644 err = 0;
1645 cleanup:
1646 return err;
1647 }
1648
1649 static int ip_mkroute_input(struct sk_buff *skb,
1650 struct fib_result *res,
1651 const struct flowi4 *fl4,
1652 struct in_device *in_dev,
1653 __be32 daddr, __be32 saddr, u32 tos)
1654 {
1655 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1656 if (res->fi && res->fi->fib_nhs > 1)
1657 fib_select_multipath(res);
1658 #endif
1659
1660 /* create a routing cache entry */
1661 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1662 }
1663
1664 /*
1665 * NOTE. We drop all the packets that has local source
1666 * addresses, because every properly looped back packet
1667 * must have correct destination already attached by output routine.
1668 *
1669 * Such approach solves two big problems:
1670 * 1. Not simplex devices are handled properly.
1671 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1672 * called with rcu_read_lock()
1673 */
1674
1675 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1676 u8 tos, struct net_device *dev)
1677 {
1678 struct fib_result res;
1679 struct in_device *in_dev = __in_dev_get_rcu(dev);
1680 struct ip_tunnel_info *tun_info;
1681 struct flowi4 fl4;
1682 unsigned int flags = 0;
1683 u32 itag = 0;
1684 struct rtable *rth;
1685 int err = -EINVAL;
1686 struct net *net = dev_net(dev);
1687 bool do_cache;
1688
1689 /* IP on this device is disabled. */
1690
1691 if (!in_dev)
1692 goto out;
1693
1694 /* Check for the most weird martians, which can be not detected
1695 by fib_lookup.
1696 */
1697
1698 tun_info = skb_tunnel_info(skb);
1699 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
1700 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
1701 else
1702 fl4.flowi4_tun_key.tun_id = 0;
1703 skb_dst_drop(skb);
1704
1705 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1706 goto martian_source;
1707
1708 res.fi = NULL;
1709 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1710 goto brd_input;
1711
1712 /* Accept zero addresses only to limited broadcast;
1713 * I even do not know to fix it or not. Waiting for complains :-)
1714 */
1715 if (ipv4_is_zeronet(saddr))
1716 goto martian_source;
1717
1718 if (ipv4_is_zeronet(daddr))
1719 goto martian_destination;
1720
1721 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1722 * and call it once if daddr or/and saddr are loopback addresses
1723 */
1724 if (ipv4_is_loopback(daddr)) {
1725 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1726 goto martian_destination;
1727 } else if (ipv4_is_loopback(saddr)) {
1728 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1729 goto martian_source;
1730 }
1731
1732 /*
1733 * Now we are ready to route packet.
1734 */
1735 fl4.flowi4_oif = 0;
1736 fl4.flowi4_iif = vrf_master_ifindex_rcu(dev) ? : dev->ifindex;
1737 fl4.flowi4_mark = skb->mark;
1738 fl4.flowi4_tos = tos;
1739 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1740 fl4.daddr = daddr;
1741 fl4.saddr = saddr;
1742 err = fib_lookup(net, &fl4, &res, 0);
1743 if (err != 0) {
1744 if (!IN_DEV_FORWARD(in_dev))
1745 err = -EHOSTUNREACH;
1746 goto no_route;
1747 }
1748
1749 if (res.type == RTN_BROADCAST)
1750 goto brd_input;
1751
1752 if (res.type == RTN_LOCAL) {
1753 err = fib_validate_source(skb, saddr, daddr, tos,
1754 0, dev, in_dev, &itag);
1755 if (err < 0)
1756 goto martian_source_keep_err;
1757 goto local_input;
1758 }
1759
1760 if (!IN_DEV_FORWARD(in_dev)) {
1761 err = -EHOSTUNREACH;
1762 goto no_route;
1763 }
1764 if (res.type != RTN_UNICAST)
1765 goto martian_destination;
1766
1767 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1768 out: return err;
1769
1770 brd_input:
1771 if (skb->protocol != htons(ETH_P_IP))
1772 goto e_inval;
1773
1774 if (!ipv4_is_zeronet(saddr)) {
1775 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1776 in_dev, &itag);
1777 if (err < 0)
1778 goto martian_source_keep_err;
1779 }
1780 flags |= RTCF_BROADCAST;
1781 res.type = RTN_BROADCAST;
1782 RT_CACHE_STAT_INC(in_brd);
1783
1784 local_input:
1785 do_cache = false;
1786 if (res.fi) {
1787 if (!itag) {
1788 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1789 if (rt_cache_valid(rth)) {
1790 skb_dst_set_noref(skb, &rth->dst);
1791 err = 0;
1792 goto out;
1793 }
1794 do_cache = true;
1795 }
1796 }
1797
1798 rth = rt_dst_alloc(net->loopback_dev,
1799 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1800 if (!rth)
1801 goto e_nobufs;
1802
1803 rth->dst.input= ip_local_deliver;
1804 rth->dst.output= ip_rt_bug;
1805 #ifdef CONFIG_IP_ROUTE_CLASSID
1806 rth->dst.tclassid = itag;
1807 #endif
1808
1809 rth->rt_genid = rt_genid_ipv4(net);
1810 rth->rt_flags = flags|RTCF_LOCAL;
1811 rth->rt_type = res.type;
1812 rth->rt_is_input = 1;
1813 rth->rt_iif = 0;
1814 rth->rt_pmtu = 0;
1815 rth->rt_gateway = 0;
1816 rth->rt_uses_gateway = 0;
1817 INIT_LIST_HEAD(&rth->rt_uncached);
1818
1819 RT_CACHE_STAT_INC(in_slow_tot);
1820 if (res.type == RTN_UNREACHABLE) {
1821 rth->dst.input= ip_error;
1822 rth->dst.error= -err;
1823 rth->rt_flags &= ~RTCF_LOCAL;
1824 }
1825 if (do_cache) {
1826 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1827 rth->dst.flags |= DST_NOCACHE;
1828 rt_add_uncached_list(rth);
1829 }
1830 }
1831 skb_dst_set(skb, &rth->dst);
1832 err = 0;
1833 goto out;
1834
1835 no_route:
1836 RT_CACHE_STAT_INC(in_no_route);
1837 res.type = RTN_UNREACHABLE;
1838 res.fi = NULL;
1839 goto local_input;
1840
1841 /*
1842 * Do not cache martian addresses: they should be logged (RFC1812)
1843 */
1844 martian_destination:
1845 RT_CACHE_STAT_INC(in_martian_dst);
1846 #ifdef CONFIG_IP_ROUTE_VERBOSE
1847 if (IN_DEV_LOG_MARTIANS(in_dev))
1848 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1849 &daddr, &saddr, dev->name);
1850 #endif
1851
1852 e_inval:
1853 err = -EINVAL;
1854 goto out;
1855
1856 e_nobufs:
1857 err = -ENOBUFS;
1858 goto out;
1859
1860 martian_source:
1861 err = -EINVAL;
1862 martian_source_keep_err:
1863 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1864 goto out;
1865 }
1866
1867 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1868 u8 tos, struct net_device *dev)
1869 {
1870 int res;
1871
1872 rcu_read_lock();
1873
1874 /* Multicast recognition logic is moved from route cache to here.
1875 The problem was that too many Ethernet cards have broken/missing
1876 hardware multicast filters :-( As result the host on multicasting
1877 network acquires a lot of useless route cache entries, sort of
1878 SDR messages from all the world. Now we try to get rid of them.
1879 Really, provided software IP multicast filter is organized
1880 reasonably (at least, hashed), it does not result in a slowdown
1881 comparing with route cache reject entries.
1882 Note, that multicast routers are not affected, because
1883 route cache entry is created eventually.
1884 */
1885 if (ipv4_is_multicast(daddr)) {
1886 struct in_device *in_dev = __in_dev_get_rcu(dev);
1887
1888 if (in_dev) {
1889 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1890 ip_hdr(skb)->protocol);
1891 if (our
1892 #ifdef CONFIG_IP_MROUTE
1893 ||
1894 (!ipv4_is_local_multicast(daddr) &&
1895 IN_DEV_MFORWARD(in_dev))
1896 #endif
1897 ) {
1898 int res = ip_route_input_mc(skb, daddr, saddr,
1899 tos, dev, our);
1900 rcu_read_unlock();
1901 return res;
1902 }
1903 }
1904 rcu_read_unlock();
1905 return -EINVAL;
1906 }
1907 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1908 rcu_read_unlock();
1909 return res;
1910 }
1911 EXPORT_SYMBOL(ip_route_input_noref);
1912
1913 /* called with rcu_read_lock() */
1914 static struct rtable *__mkroute_output(const struct fib_result *res,
1915 const struct flowi4 *fl4, int orig_oif,
1916 struct net_device *dev_out,
1917 unsigned int flags)
1918 {
1919 struct fib_info *fi = res->fi;
1920 struct fib_nh_exception *fnhe;
1921 struct in_device *in_dev;
1922 u16 type = res->type;
1923 struct rtable *rth;
1924 bool do_cache;
1925
1926 in_dev = __in_dev_get_rcu(dev_out);
1927 if (!in_dev)
1928 return ERR_PTR(-EINVAL);
1929
1930 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1931 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1932 return ERR_PTR(-EINVAL);
1933
1934 if (ipv4_is_lbcast(fl4->daddr))
1935 type = RTN_BROADCAST;
1936 else if (ipv4_is_multicast(fl4->daddr))
1937 type = RTN_MULTICAST;
1938 else if (ipv4_is_zeronet(fl4->daddr))
1939 return ERR_PTR(-EINVAL);
1940
1941 if (dev_out->flags & IFF_LOOPBACK)
1942 flags |= RTCF_LOCAL;
1943
1944 do_cache = true;
1945 if (type == RTN_BROADCAST) {
1946 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1947 fi = NULL;
1948 } else if (type == RTN_MULTICAST) {
1949 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1950 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1951 fl4->flowi4_proto))
1952 flags &= ~RTCF_LOCAL;
1953 else
1954 do_cache = false;
1955 /* If multicast route do not exist use
1956 * default one, but do not gateway in this case.
1957 * Yes, it is hack.
1958 */
1959 if (fi && res->prefixlen < 4)
1960 fi = NULL;
1961 }
1962
1963 fnhe = NULL;
1964 do_cache &= fi != NULL;
1965 if (do_cache) {
1966 struct rtable __rcu **prth;
1967 struct fib_nh *nh = &FIB_RES_NH(*res);
1968
1969 fnhe = find_exception(nh, fl4->daddr);
1970 if (fnhe)
1971 prth = &fnhe->fnhe_rth_output;
1972 else {
1973 if (unlikely(fl4->flowi4_flags &
1974 FLOWI_FLAG_KNOWN_NH &&
1975 !(nh->nh_gw &&
1976 nh->nh_scope == RT_SCOPE_LINK))) {
1977 do_cache = false;
1978 goto add;
1979 }
1980 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
1981 }
1982 rth = rcu_dereference(*prth);
1983 if (rt_cache_valid(rth)) {
1984 dst_hold(&rth->dst);
1985 return rth;
1986 }
1987 }
1988
1989 add:
1990 rth = rt_dst_alloc(dev_out,
1991 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1992 IN_DEV_CONF_GET(in_dev, NOXFRM),
1993 do_cache);
1994 if (!rth)
1995 return ERR_PTR(-ENOBUFS);
1996
1997 rth->dst.output = ip_output;
1998
1999 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out));
2000 rth->rt_flags = flags;
2001 rth->rt_type = type;
2002 rth->rt_is_input = 0;
2003 rth->rt_iif = orig_oif ? : 0;
2004 rth->rt_pmtu = 0;
2005 rth->rt_gateway = 0;
2006 rth->rt_uses_gateway = 0;
2007 INIT_LIST_HEAD(&rth->rt_uncached);
2008 RT_CACHE_STAT_INC(out_slow_tot);
2009
2010 if (flags & RTCF_LOCAL)
2011 rth->dst.input = ip_local_deliver;
2012 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2013 if (flags & RTCF_LOCAL &&
2014 !(dev_out->flags & IFF_LOOPBACK)) {
2015 rth->dst.output = ip_mc_output;
2016 RT_CACHE_STAT_INC(out_slow_mc);
2017 }
2018 #ifdef CONFIG_IP_MROUTE
2019 if (type == RTN_MULTICAST) {
2020 if (IN_DEV_MFORWARD(in_dev) &&
2021 !ipv4_is_local_multicast(fl4->daddr)) {
2022 rth->dst.input = ip_mr_input;
2023 rth->dst.output = ip_mc_output;
2024 }
2025 }
2026 #endif
2027 }
2028
2029 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
2030 if (lwtunnel_output_redirect(rth->dst.lwtstate))
2031 rth->dst.output = lwtunnel_output;
2032
2033 return rth;
2034 }
2035
2036 /*
2037 * Major route resolver routine.
2038 */
2039
2040 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
2041 {
2042 struct net_device *dev_out = NULL;
2043 __u8 tos = RT_FL_TOS(fl4);
2044 unsigned int flags = 0;
2045 struct fib_result res;
2046 struct rtable *rth;
2047 int orig_oif;
2048
2049 res.tclassid = 0;
2050 res.fi = NULL;
2051 res.table = NULL;
2052
2053 orig_oif = fl4->flowi4_oif;
2054
2055 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2056 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2057 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2058 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2059
2060 rcu_read_lock();
2061 if (fl4->saddr) {
2062 rth = ERR_PTR(-EINVAL);
2063 if (ipv4_is_multicast(fl4->saddr) ||
2064 ipv4_is_lbcast(fl4->saddr) ||
2065 ipv4_is_zeronet(fl4->saddr))
2066 goto out;
2067
2068 /* I removed check for oif == dev_out->oif here.
2069 It was wrong for two reasons:
2070 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2071 is assigned to multiple interfaces.
2072 2. Moreover, we are allowed to send packets with saddr
2073 of another iface. --ANK
2074 */
2075
2076 if (fl4->flowi4_oif == 0 &&
2077 (ipv4_is_multicast(fl4->daddr) ||
2078 ipv4_is_lbcast(fl4->daddr))) {
2079 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2080 dev_out = __ip_dev_find(net, fl4->saddr, false);
2081 if (!dev_out)
2082 goto out;
2083
2084 /* Special hack: user can direct multicasts
2085 and limited broadcast via necessary interface
2086 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2087 This hack is not just for fun, it allows
2088 vic,vat and friends to work.
2089 They bind socket to loopback, set ttl to zero
2090 and expect that it will work.
2091 From the viewpoint of routing cache they are broken,
2092 because we are not allowed to build multicast path
2093 with loopback source addr (look, routing cache
2094 cannot know, that ttl is zero, so that packet
2095 will not leave this host and route is valid).
2096 Luckily, this hack is good workaround.
2097 */
2098
2099 fl4->flowi4_oif = dev_out->ifindex;
2100 goto make_route;
2101 }
2102
2103 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2104 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2105 if (!__ip_dev_find(net, fl4->saddr, false))
2106 goto out;
2107 }
2108 }
2109
2110
2111 if (fl4->flowi4_oif) {
2112 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2113 rth = ERR_PTR(-ENODEV);
2114 if (!dev_out)
2115 goto out;
2116
2117 /* RACE: Check return value of inet_select_addr instead. */
2118 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2119 rth = ERR_PTR(-ENETUNREACH);
2120 goto out;
2121 }
2122 if (ipv4_is_local_multicast(fl4->daddr) ||
2123 ipv4_is_lbcast(fl4->daddr) ||
2124 fl4->flowi4_proto == IPPROTO_IGMP) {
2125 if (!fl4->saddr)
2126 fl4->saddr = inet_select_addr(dev_out, 0,
2127 RT_SCOPE_LINK);
2128 goto make_route;
2129 }
2130 if (!fl4->saddr) {
2131 if (ipv4_is_multicast(fl4->daddr))
2132 fl4->saddr = inet_select_addr(dev_out, 0,
2133 fl4->flowi4_scope);
2134 else if (!fl4->daddr)
2135 fl4->saddr = inet_select_addr(dev_out, 0,
2136 RT_SCOPE_HOST);
2137 }
2138 if (netif_is_vrf(dev_out) &&
2139 !(fl4->flowi4_flags & FLOWI_FLAG_VRFSRC)) {
2140 rth = vrf_dev_get_rth(dev_out);
2141 goto out;
2142 }
2143 }
2144
2145 if (!fl4->daddr) {
2146 fl4->daddr = fl4->saddr;
2147 if (!fl4->daddr)
2148 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2149 dev_out = net->loopback_dev;
2150 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2151 res.type = RTN_LOCAL;
2152 flags |= RTCF_LOCAL;
2153 goto make_route;
2154 }
2155
2156 if (fib_lookup(net, fl4, &res, 0)) {
2157 res.fi = NULL;
2158 res.table = NULL;
2159 if (fl4->flowi4_oif) {
2160 /* Apparently, routing tables are wrong. Assume,
2161 that the destination is on link.
2162
2163 WHY? DW.
2164 Because we are allowed to send to iface
2165 even if it has NO routes and NO assigned
2166 addresses. When oif is specified, routing
2167 tables are looked up with only one purpose:
2168 to catch if destination is gatewayed, rather than
2169 direct. Moreover, if MSG_DONTROUTE is set,
2170 we send packet, ignoring both routing tables
2171 and ifaddr state. --ANK
2172
2173
2174 We could make it even if oif is unknown,
2175 likely IPv6, but we do not.
2176 */
2177
2178 if (fl4->saddr == 0)
2179 fl4->saddr = inet_select_addr(dev_out, 0,
2180 RT_SCOPE_LINK);
2181 res.type = RTN_UNICAST;
2182 goto make_route;
2183 }
2184 rth = ERR_PTR(-ENETUNREACH);
2185 goto out;
2186 }
2187
2188 if (res.type == RTN_LOCAL) {
2189 if (!fl4->saddr) {
2190 if (res.fi->fib_prefsrc)
2191 fl4->saddr = res.fi->fib_prefsrc;
2192 else
2193 fl4->saddr = fl4->daddr;
2194 }
2195 dev_out = net->loopback_dev;
2196 fl4->flowi4_oif = dev_out->ifindex;
2197 flags |= RTCF_LOCAL;
2198 goto make_route;
2199 }
2200
2201 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2202 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2203 fib_select_multipath(&res);
2204 else
2205 #endif
2206 if (!res.prefixlen &&
2207 res.table->tb_num_default > 1 &&
2208 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2209 fib_select_default(fl4, &res);
2210
2211 if (!fl4->saddr)
2212 fl4->saddr = FIB_RES_PREFSRC(net, res);
2213
2214 dev_out = FIB_RES_DEV(res);
2215 fl4->flowi4_oif = dev_out->ifindex;
2216
2217
2218 make_route:
2219 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2220
2221 out:
2222 rcu_read_unlock();
2223 return rth;
2224 }
2225 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2226
2227 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2228 {
2229 return NULL;
2230 }
2231
2232 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2233 {
2234 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2235
2236 return mtu ? : dst->dev->mtu;
2237 }
2238
2239 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2240 struct sk_buff *skb, u32 mtu)
2241 {
2242 }
2243
2244 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2245 struct sk_buff *skb)
2246 {
2247 }
2248
2249 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2250 unsigned long old)
2251 {
2252 return NULL;
2253 }
2254
2255 static struct dst_ops ipv4_dst_blackhole_ops = {
2256 .family = AF_INET,
2257 .check = ipv4_blackhole_dst_check,
2258 .mtu = ipv4_blackhole_mtu,
2259 .default_advmss = ipv4_default_advmss,
2260 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2261 .redirect = ipv4_rt_blackhole_redirect,
2262 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2263 .neigh_lookup = ipv4_neigh_lookup,
2264 };
2265
2266 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2267 {
2268 struct rtable *ort = (struct rtable *) dst_orig;
2269 struct rtable *rt;
2270
2271 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2272 if (rt) {
2273 struct dst_entry *new = &rt->dst;
2274
2275 new->__use = 1;
2276 new->input = dst_discard;
2277 new->output = dst_discard_sk;
2278
2279 new->dev = ort->dst.dev;
2280 if (new->dev)
2281 dev_hold(new->dev);
2282
2283 rt->rt_is_input = ort->rt_is_input;
2284 rt->rt_iif = ort->rt_iif;
2285 rt->rt_pmtu = ort->rt_pmtu;
2286
2287 rt->rt_genid = rt_genid_ipv4(net);
2288 rt->rt_flags = ort->rt_flags;
2289 rt->rt_type = ort->rt_type;
2290 rt->rt_gateway = ort->rt_gateway;
2291 rt->rt_uses_gateway = ort->rt_uses_gateway;
2292
2293 INIT_LIST_HEAD(&rt->rt_uncached);
2294 dst_free(new);
2295 }
2296
2297 dst_release(dst_orig);
2298
2299 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2300 }
2301
2302 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2303 struct sock *sk)
2304 {
2305 struct rtable *rt = __ip_route_output_key(net, flp4);
2306
2307 if (IS_ERR(rt))
2308 return rt;
2309
2310 if (flp4->flowi4_proto)
2311 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2312 flowi4_to_flowi(flp4),
2313 sk, 0);
2314
2315 return rt;
2316 }
2317 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2318
2319 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2320 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2321 u32 seq, int event, int nowait, unsigned int flags)
2322 {
2323 struct rtable *rt = skb_rtable(skb);
2324 struct rtmsg *r;
2325 struct nlmsghdr *nlh;
2326 unsigned long expires = 0;
2327 u32 error;
2328 u32 metrics[RTAX_MAX];
2329
2330 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2331 if (!nlh)
2332 return -EMSGSIZE;
2333
2334 r = nlmsg_data(nlh);
2335 r->rtm_family = AF_INET;
2336 r->rtm_dst_len = 32;
2337 r->rtm_src_len = 0;
2338 r->rtm_tos = fl4->flowi4_tos;
2339 r->rtm_table = RT_TABLE_MAIN;
2340 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2341 goto nla_put_failure;
2342 r->rtm_type = rt->rt_type;
2343 r->rtm_scope = RT_SCOPE_UNIVERSE;
2344 r->rtm_protocol = RTPROT_UNSPEC;
2345 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2346 if (rt->rt_flags & RTCF_NOTIFY)
2347 r->rtm_flags |= RTM_F_NOTIFY;
2348 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2349 r->rtm_flags |= RTCF_DOREDIRECT;
2350
2351 if (nla_put_in_addr(skb, RTA_DST, dst))
2352 goto nla_put_failure;
2353 if (src) {
2354 r->rtm_src_len = 32;
2355 if (nla_put_in_addr(skb, RTA_SRC, src))
2356 goto nla_put_failure;
2357 }
2358 if (rt->dst.dev &&
2359 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2360 goto nla_put_failure;
2361 #ifdef CONFIG_IP_ROUTE_CLASSID
2362 if (rt->dst.tclassid &&
2363 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2364 goto nla_put_failure;
2365 #endif
2366 if (!rt_is_input_route(rt) &&
2367 fl4->saddr != src) {
2368 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2369 goto nla_put_failure;
2370 }
2371 if (rt->rt_uses_gateway &&
2372 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2373 goto nla_put_failure;
2374
2375 expires = rt->dst.expires;
2376 if (expires) {
2377 unsigned long now = jiffies;
2378
2379 if (time_before(now, expires))
2380 expires -= now;
2381 else
2382 expires = 0;
2383 }
2384
2385 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2386 if (rt->rt_pmtu && expires)
2387 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2388 if (rtnetlink_put_metrics(skb, metrics) < 0)
2389 goto nla_put_failure;
2390
2391 if (fl4->flowi4_mark &&
2392 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2393 goto nla_put_failure;
2394
2395 error = rt->dst.error;
2396
2397 if (rt_is_input_route(rt)) {
2398 #ifdef CONFIG_IP_MROUTE
2399 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2400 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2401 int err = ipmr_get_route(net, skb,
2402 fl4->saddr, fl4->daddr,
2403 r, nowait);
2404 if (err <= 0) {
2405 if (!nowait) {
2406 if (err == 0)
2407 return 0;
2408 goto nla_put_failure;
2409 } else {
2410 if (err == -EMSGSIZE)
2411 goto nla_put_failure;
2412 error = err;
2413 }
2414 }
2415 } else
2416 #endif
2417 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2418 goto nla_put_failure;
2419 }
2420
2421 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2422 goto nla_put_failure;
2423
2424 nlmsg_end(skb, nlh);
2425 return 0;
2426
2427 nla_put_failure:
2428 nlmsg_cancel(skb, nlh);
2429 return -EMSGSIZE;
2430 }
2431
2432 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2433 {
2434 struct net *net = sock_net(in_skb->sk);
2435 struct rtmsg *rtm;
2436 struct nlattr *tb[RTA_MAX+1];
2437 struct rtable *rt = NULL;
2438 struct flowi4 fl4;
2439 __be32 dst = 0;
2440 __be32 src = 0;
2441 u32 iif;
2442 int err;
2443 int mark;
2444 struct sk_buff *skb;
2445
2446 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2447 if (err < 0)
2448 goto errout;
2449
2450 rtm = nlmsg_data(nlh);
2451
2452 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2453 if (!skb) {
2454 err = -ENOBUFS;
2455 goto errout;
2456 }
2457
2458 /* Reserve room for dummy headers, this skb can pass
2459 through good chunk of routing engine.
2460 */
2461 skb_reset_mac_header(skb);
2462 skb_reset_network_header(skb);
2463
2464 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2465 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2466 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2467
2468 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2469 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2470 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2471 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2472
2473 memset(&fl4, 0, sizeof(fl4));
2474 fl4.daddr = dst;
2475 fl4.saddr = src;
2476 fl4.flowi4_tos = rtm->rtm_tos;
2477 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2478 fl4.flowi4_mark = mark;
2479
2480 if (iif) {
2481 struct net_device *dev;
2482
2483 dev = __dev_get_by_index(net, iif);
2484 if (!dev) {
2485 err = -ENODEV;
2486 goto errout_free;
2487 }
2488
2489 skb->protocol = htons(ETH_P_IP);
2490 skb->dev = dev;
2491 skb->mark = mark;
2492 local_bh_disable();
2493 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2494 local_bh_enable();
2495
2496 rt = skb_rtable(skb);
2497 if (err == 0 && rt->dst.error)
2498 err = -rt->dst.error;
2499 } else {
2500 rt = ip_route_output_key(net, &fl4);
2501
2502 err = 0;
2503 if (IS_ERR(rt))
2504 err = PTR_ERR(rt);
2505 }
2506
2507 if (err)
2508 goto errout_free;
2509
2510 skb_dst_set(skb, &rt->dst);
2511 if (rtm->rtm_flags & RTM_F_NOTIFY)
2512 rt->rt_flags |= RTCF_NOTIFY;
2513
2514 err = rt_fill_info(net, dst, src, &fl4, skb,
2515 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2516 RTM_NEWROUTE, 0, 0);
2517 if (err < 0)
2518 goto errout_free;
2519
2520 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2521 errout:
2522 return err;
2523
2524 errout_free:
2525 kfree_skb(skb);
2526 goto errout;
2527 }
2528
2529 void ip_rt_multicast_event(struct in_device *in_dev)
2530 {
2531 rt_cache_flush(dev_net(in_dev->dev));
2532 }
2533
2534 #ifdef CONFIG_SYSCTL
2535 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2536 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2537 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2538 static int ip_rt_gc_elasticity __read_mostly = 8;
2539
2540 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2541 void __user *buffer,
2542 size_t *lenp, loff_t *ppos)
2543 {
2544 struct net *net = (struct net *)__ctl->extra1;
2545
2546 if (write) {
2547 rt_cache_flush(net);
2548 fnhe_genid_bump(net);
2549 return 0;
2550 }
2551
2552 return -EINVAL;
2553 }
2554
2555 static struct ctl_table ipv4_route_table[] = {
2556 {
2557 .procname = "gc_thresh",
2558 .data = &ipv4_dst_ops.gc_thresh,
2559 .maxlen = sizeof(int),
2560 .mode = 0644,
2561 .proc_handler = proc_dointvec,
2562 },
2563 {
2564 .procname = "max_size",
2565 .data = &ip_rt_max_size,
2566 .maxlen = sizeof(int),
2567 .mode = 0644,
2568 .proc_handler = proc_dointvec,
2569 },
2570 {
2571 /* Deprecated. Use gc_min_interval_ms */
2572
2573 .procname = "gc_min_interval",
2574 .data = &ip_rt_gc_min_interval,
2575 .maxlen = sizeof(int),
2576 .mode = 0644,
2577 .proc_handler = proc_dointvec_jiffies,
2578 },
2579 {
2580 .procname = "gc_min_interval_ms",
2581 .data = &ip_rt_gc_min_interval,
2582 .maxlen = sizeof(int),
2583 .mode = 0644,
2584 .proc_handler = proc_dointvec_ms_jiffies,
2585 },
2586 {
2587 .procname = "gc_timeout",
2588 .data = &ip_rt_gc_timeout,
2589 .maxlen = sizeof(int),
2590 .mode = 0644,
2591 .proc_handler = proc_dointvec_jiffies,
2592 },
2593 {
2594 .procname = "gc_interval",
2595 .data = &ip_rt_gc_interval,
2596 .maxlen = sizeof(int),
2597 .mode = 0644,
2598 .proc_handler = proc_dointvec_jiffies,
2599 },
2600 {
2601 .procname = "redirect_load",
2602 .data = &ip_rt_redirect_load,
2603 .maxlen = sizeof(int),
2604 .mode = 0644,
2605 .proc_handler = proc_dointvec,
2606 },
2607 {
2608 .procname = "redirect_number",
2609 .data = &ip_rt_redirect_number,
2610 .maxlen = sizeof(int),
2611 .mode = 0644,
2612 .proc_handler = proc_dointvec,
2613 },
2614 {
2615 .procname = "redirect_silence",
2616 .data = &ip_rt_redirect_silence,
2617 .maxlen = sizeof(int),
2618 .mode = 0644,
2619 .proc_handler = proc_dointvec,
2620 },
2621 {
2622 .procname = "error_cost",
2623 .data = &ip_rt_error_cost,
2624 .maxlen = sizeof(int),
2625 .mode = 0644,
2626 .proc_handler = proc_dointvec,
2627 },
2628 {
2629 .procname = "error_burst",
2630 .data = &ip_rt_error_burst,
2631 .maxlen = sizeof(int),
2632 .mode = 0644,
2633 .proc_handler = proc_dointvec,
2634 },
2635 {
2636 .procname = "gc_elasticity",
2637 .data = &ip_rt_gc_elasticity,
2638 .maxlen = sizeof(int),
2639 .mode = 0644,
2640 .proc_handler = proc_dointvec,
2641 },
2642 {
2643 .procname = "mtu_expires",
2644 .data = &ip_rt_mtu_expires,
2645 .maxlen = sizeof(int),
2646 .mode = 0644,
2647 .proc_handler = proc_dointvec_jiffies,
2648 },
2649 {
2650 .procname = "min_pmtu",
2651 .data = &ip_rt_min_pmtu,
2652 .maxlen = sizeof(int),
2653 .mode = 0644,
2654 .proc_handler = proc_dointvec,
2655 },
2656 {
2657 .procname = "min_adv_mss",
2658 .data = &ip_rt_min_advmss,
2659 .maxlen = sizeof(int),
2660 .mode = 0644,
2661 .proc_handler = proc_dointvec,
2662 },
2663 { }
2664 };
2665
2666 static struct ctl_table ipv4_route_flush_table[] = {
2667 {
2668 .procname = "flush",
2669 .maxlen = sizeof(int),
2670 .mode = 0200,
2671 .proc_handler = ipv4_sysctl_rtcache_flush,
2672 },
2673 { },
2674 };
2675
2676 static __net_init int sysctl_route_net_init(struct net *net)
2677 {
2678 struct ctl_table *tbl;
2679
2680 tbl = ipv4_route_flush_table;
2681 if (!net_eq(net, &init_net)) {
2682 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2683 if (!tbl)
2684 goto err_dup;
2685
2686 /* Don't export sysctls to unprivileged users */
2687 if (net->user_ns != &init_user_ns)
2688 tbl[0].procname = NULL;
2689 }
2690 tbl[0].extra1 = net;
2691
2692 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2693 if (!net->ipv4.route_hdr)
2694 goto err_reg;
2695 return 0;
2696
2697 err_reg:
2698 if (tbl != ipv4_route_flush_table)
2699 kfree(tbl);
2700 err_dup:
2701 return -ENOMEM;
2702 }
2703
2704 static __net_exit void sysctl_route_net_exit(struct net *net)
2705 {
2706 struct ctl_table *tbl;
2707
2708 tbl = net->ipv4.route_hdr->ctl_table_arg;
2709 unregister_net_sysctl_table(net->ipv4.route_hdr);
2710 BUG_ON(tbl == ipv4_route_flush_table);
2711 kfree(tbl);
2712 }
2713
2714 static __net_initdata struct pernet_operations sysctl_route_ops = {
2715 .init = sysctl_route_net_init,
2716 .exit = sysctl_route_net_exit,
2717 };
2718 #endif
2719
2720 static __net_init int rt_genid_init(struct net *net)
2721 {
2722 atomic_set(&net->ipv4.rt_genid, 0);
2723 atomic_set(&net->fnhe_genid, 0);
2724 get_random_bytes(&net->ipv4.dev_addr_genid,
2725 sizeof(net->ipv4.dev_addr_genid));
2726 return 0;
2727 }
2728
2729 static __net_initdata struct pernet_operations rt_genid_ops = {
2730 .init = rt_genid_init,
2731 };
2732
2733 static int __net_init ipv4_inetpeer_init(struct net *net)
2734 {
2735 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2736
2737 if (!bp)
2738 return -ENOMEM;
2739 inet_peer_base_init(bp);
2740 net->ipv4.peers = bp;
2741 return 0;
2742 }
2743
2744 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2745 {
2746 struct inet_peer_base *bp = net->ipv4.peers;
2747
2748 net->ipv4.peers = NULL;
2749 inetpeer_invalidate_tree(bp);
2750 kfree(bp);
2751 }
2752
2753 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2754 .init = ipv4_inetpeer_init,
2755 .exit = ipv4_inetpeer_exit,
2756 };
2757
2758 #ifdef CONFIG_IP_ROUTE_CLASSID
2759 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2760 #endif /* CONFIG_IP_ROUTE_CLASSID */
2761
2762 int __init ip_rt_init(void)
2763 {
2764 int rc = 0;
2765 int cpu;
2766
2767 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2768 if (!ip_idents)
2769 panic("IP: failed to allocate ip_idents\n");
2770
2771 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2772
2773 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
2774 if (!ip_tstamps)
2775 panic("IP: failed to allocate ip_tstamps\n");
2776
2777 for_each_possible_cpu(cpu) {
2778 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
2779
2780 INIT_LIST_HEAD(&ul->head);
2781 spin_lock_init(&ul->lock);
2782 }
2783 #ifdef CONFIG_IP_ROUTE_CLASSID
2784 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2785 if (!ip_rt_acct)
2786 panic("IP: failed to allocate ip_rt_acct\n");
2787 #endif
2788
2789 ipv4_dst_ops.kmem_cachep =
2790 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2791 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2792
2793 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2794
2795 if (dst_entries_init(&ipv4_dst_ops) < 0)
2796 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2797
2798 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2799 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2800
2801 ipv4_dst_ops.gc_thresh = ~0;
2802 ip_rt_max_size = INT_MAX;
2803
2804 devinet_init();
2805 ip_fib_init();
2806
2807 if (ip_rt_proc_init())
2808 pr_err("Unable to create route proc files\n");
2809 #ifdef CONFIG_XFRM
2810 xfrm_init();
2811 xfrm4_init();
2812 #endif
2813 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2814
2815 #ifdef CONFIG_SYSCTL
2816 register_pernet_subsys(&sysctl_route_ops);
2817 #endif
2818 register_pernet_subsys(&rt_genid_ops);
2819 register_pernet_subsys(&ipv4_inetpeer_ops);
2820 return rc;
2821 }
2822
2823 #ifdef CONFIG_SYSCTL
2824 /*
2825 * We really need to sanitize the damn ipv4 init order, then all
2826 * this nonsense will go away.
2827 */
2828 void __init ip_static_sysctl_init(void)
2829 {
2830 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2831 }
2832 #endif
Linux kernel - Deliverables
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