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ipv4: L3 hash-based multipath
[deliverable/linux.git] / net / ipv4 / route.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65 #define pr_fmt(fmt) "IPv4: " fmt
66
67 #include <linux/module.h>
68 #include <asm/uaccess.h>
69 #include <linux/bitops.h>
70 #include <linux/types.h>
71 #include <linux/kernel.h>
72 #include <linux/mm.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
77 #include <linux/in.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/skbuff.h>
83 #include <linux/inetdevice.h>
84 #include <linux/igmp.h>
85 #include <linux/pkt_sched.h>
86 #include <linux/mroute.h>
87 #include <linux/netfilter_ipv4.h>
88 #include <linux/random.h>
89 #include <linux/rcupdate.h>
90 #include <linux/times.h>
91 #include <linux/slab.h>
92 #include <linux/jhash.h>
93 #include <net/dst.h>
94 #include <net/dst_metadata.h>
95 #include <net/net_namespace.h>
96 #include <net/protocol.h>
97 #include <net/ip.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
102 #include <net/arp.h>
103 #include <net/tcp.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/lwtunnel.h>
107 #include <net/netevent.h>
108 #include <net/rtnetlink.h>
109 #ifdef CONFIG_SYSCTL
110 #include <linux/sysctl.h>
111 #include <linux/kmemleak.h>
112 #endif
113 #include <net/secure_seq.h>
114 #include <net/ip_tunnels.h>
115 #include <net/l3mdev.h>
116
117 #define RT_FL_TOS(oldflp4) \
118 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
119
120 #define RT_GC_TIMEOUT (300*HZ)
121
122 static int ip_rt_max_size;
123 static int ip_rt_redirect_number __read_mostly = 9;
124 static int ip_rt_redirect_load __read_mostly = HZ / 50;
125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly = HZ;
127 static int ip_rt_error_burst __read_mostly = 5 * HZ;
128 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
129 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
130 static int ip_rt_min_advmss __read_mostly = 256;
131
132 /*
133 * Interface to generic destination cache.
134 */
135
136 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
137 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
138 static unsigned int ipv4_mtu(const struct dst_entry *dst);
139 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
140 static void ipv4_link_failure(struct sk_buff *skb);
141 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
142 struct sk_buff *skb, u32 mtu);
143 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
144 struct sk_buff *skb);
145 static void ipv4_dst_destroy(struct dst_entry *dst);
146
147 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
148 {
149 WARN_ON(1);
150 return NULL;
151 }
152
153 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
154 struct sk_buff *skb,
155 const void *daddr);
156
157 static struct dst_ops ipv4_dst_ops = {
158 .family = AF_INET,
159 .check = ipv4_dst_check,
160 .default_advmss = ipv4_default_advmss,
161 .mtu = ipv4_mtu,
162 .cow_metrics = ipv4_cow_metrics,
163 .destroy = ipv4_dst_destroy,
164 .negative_advice = ipv4_negative_advice,
165 .link_failure = ipv4_link_failure,
166 .update_pmtu = ip_rt_update_pmtu,
167 .redirect = ip_do_redirect,
168 .local_out = __ip_local_out,
169 .neigh_lookup = ipv4_neigh_lookup,
170 };
171
172 #define ECN_OR_COST(class) TC_PRIO_##class
173
174 const __u8 ip_tos2prio[16] = {
175 TC_PRIO_BESTEFFORT,
176 ECN_OR_COST(BESTEFFORT),
177 TC_PRIO_BESTEFFORT,
178 ECN_OR_COST(BESTEFFORT),
179 TC_PRIO_BULK,
180 ECN_OR_COST(BULK),
181 TC_PRIO_BULK,
182 ECN_OR_COST(BULK),
183 TC_PRIO_INTERACTIVE,
184 ECN_OR_COST(INTERACTIVE),
185 TC_PRIO_INTERACTIVE,
186 ECN_OR_COST(INTERACTIVE),
187 TC_PRIO_INTERACTIVE_BULK,
188 ECN_OR_COST(INTERACTIVE_BULK),
189 TC_PRIO_INTERACTIVE_BULK,
190 ECN_OR_COST(INTERACTIVE_BULK)
191 };
192 EXPORT_SYMBOL(ip_tos2prio);
193
194 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
195 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
196
197 #ifdef CONFIG_PROC_FS
198 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
199 {
200 if (*pos)
201 return NULL;
202 return SEQ_START_TOKEN;
203 }
204
205 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
206 {
207 ++*pos;
208 return NULL;
209 }
210
211 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
212 {
213 }
214
215 static int rt_cache_seq_show(struct seq_file *seq, void *v)
216 {
217 if (v == SEQ_START_TOKEN)
218 seq_printf(seq, "%-127s\n",
219 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
220 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
221 "HHUptod\tSpecDst");
222 return 0;
223 }
224
225 static const struct seq_operations rt_cache_seq_ops = {
226 .start = rt_cache_seq_start,
227 .next = rt_cache_seq_next,
228 .stop = rt_cache_seq_stop,
229 .show = rt_cache_seq_show,
230 };
231
232 static int rt_cache_seq_open(struct inode *inode, struct file *file)
233 {
234 return seq_open(file, &rt_cache_seq_ops);
235 }
236
237 static const struct file_operations rt_cache_seq_fops = {
238 .owner = THIS_MODULE,
239 .open = rt_cache_seq_open,
240 .read = seq_read,
241 .llseek = seq_lseek,
242 .release = seq_release,
243 };
244
245
246 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
247 {
248 int cpu;
249
250 if (*pos == 0)
251 return SEQ_START_TOKEN;
252
253 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
254 if (!cpu_possible(cpu))
255 continue;
256 *pos = cpu+1;
257 return &per_cpu(rt_cache_stat, cpu);
258 }
259 return NULL;
260 }
261
262 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
263 {
264 int cpu;
265
266 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
267 if (!cpu_possible(cpu))
268 continue;
269 *pos = cpu+1;
270 return &per_cpu(rt_cache_stat, cpu);
271 }
272 return NULL;
273
274 }
275
276 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
277 {
278
279 }
280
281 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
282 {
283 struct rt_cache_stat *st = v;
284
285 if (v == SEQ_START_TOKEN) {
286 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
287 return 0;
288 }
289
290 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
291 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
292 dst_entries_get_slow(&ipv4_dst_ops),
293 0, /* st->in_hit */
294 st->in_slow_tot,
295 st->in_slow_mc,
296 st->in_no_route,
297 st->in_brd,
298 st->in_martian_dst,
299 st->in_martian_src,
300
301 0, /* st->out_hit */
302 st->out_slow_tot,
303 st->out_slow_mc,
304
305 0, /* st->gc_total */
306 0, /* st->gc_ignored */
307 0, /* st->gc_goal_miss */
308 0, /* st->gc_dst_overflow */
309 0, /* st->in_hlist_search */
310 0 /* st->out_hlist_search */
311 );
312 return 0;
313 }
314
315 static const struct seq_operations rt_cpu_seq_ops = {
316 .start = rt_cpu_seq_start,
317 .next = rt_cpu_seq_next,
318 .stop = rt_cpu_seq_stop,
319 .show = rt_cpu_seq_show,
320 };
321
322
323 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
324 {
325 return seq_open(file, &rt_cpu_seq_ops);
326 }
327
328 static const struct file_operations rt_cpu_seq_fops = {
329 .owner = THIS_MODULE,
330 .open = rt_cpu_seq_open,
331 .read = seq_read,
332 .llseek = seq_lseek,
333 .release = seq_release,
334 };
335
336 #ifdef CONFIG_IP_ROUTE_CLASSID
337 static int rt_acct_proc_show(struct seq_file *m, void *v)
338 {
339 struct ip_rt_acct *dst, *src;
340 unsigned int i, j;
341
342 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
343 if (!dst)
344 return -ENOMEM;
345
346 for_each_possible_cpu(i) {
347 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
348 for (j = 0; j < 256; j++) {
349 dst[j].o_bytes += src[j].o_bytes;
350 dst[j].o_packets += src[j].o_packets;
351 dst[j].i_bytes += src[j].i_bytes;
352 dst[j].i_packets += src[j].i_packets;
353 }
354 }
355
356 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
357 kfree(dst);
358 return 0;
359 }
360
361 static int rt_acct_proc_open(struct inode *inode, struct file *file)
362 {
363 return single_open(file, rt_acct_proc_show, NULL);
364 }
365
366 static const struct file_operations rt_acct_proc_fops = {
367 .owner = THIS_MODULE,
368 .open = rt_acct_proc_open,
369 .read = seq_read,
370 .llseek = seq_lseek,
371 .release = single_release,
372 };
373 #endif
374
375 static int __net_init ip_rt_do_proc_init(struct net *net)
376 {
377 struct proc_dir_entry *pde;
378
379 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
380 &rt_cache_seq_fops);
381 if (!pde)
382 goto err1;
383
384 pde = proc_create("rt_cache", S_IRUGO,
385 net->proc_net_stat, &rt_cpu_seq_fops);
386 if (!pde)
387 goto err2;
388
389 #ifdef CONFIG_IP_ROUTE_CLASSID
390 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
391 if (!pde)
392 goto err3;
393 #endif
394 return 0;
395
396 #ifdef CONFIG_IP_ROUTE_CLASSID
397 err3:
398 remove_proc_entry("rt_cache", net->proc_net_stat);
399 #endif
400 err2:
401 remove_proc_entry("rt_cache", net->proc_net);
402 err1:
403 return -ENOMEM;
404 }
405
406 static void __net_exit ip_rt_do_proc_exit(struct net *net)
407 {
408 remove_proc_entry("rt_cache", net->proc_net_stat);
409 remove_proc_entry("rt_cache", net->proc_net);
410 #ifdef CONFIG_IP_ROUTE_CLASSID
411 remove_proc_entry("rt_acct", net->proc_net);
412 #endif
413 }
414
415 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
416 .init = ip_rt_do_proc_init,
417 .exit = ip_rt_do_proc_exit,
418 };
419
420 static int __init ip_rt_proc_init(void)
421 {
422 return register_pernet_subsys(&ip_rt_proc_ops);
423 }
424
425 #else
426 static inline int ip_rt_proc_init(void)
427 {
428 return 0;
429 }
430 #endif /* CONFIG_PROC_FS */
431
432 static inline bool rt_is_expired(const struct rtable *rth)
433 {
434 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
435 }
436
437 void rt_cache_flush(struct net *net)
438 {
439 rt_genid_bump_ipv4(net);
440 }
441
442 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
443 struct sk_buff *skb,
444 const void *daddr)
445 {
446 struct net_device *dev = dst->dev;
447 const __be32 *pkey = daddr;
448 const struct rtable *rt;
449 struct neighbour *n;
450
451 rt = (const struct rtable *) dst;
452 if (rt->rt_gateway)
453 pkey = (const __be32 *) &rt->rt_gateway;
454 else if (skb)
455 pkey = &ip_hdr(skb)->daddr;
456
457 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
458 if (n)
459 return n;
460 return neigh_create(&arp_tbl, pkey, dev);
461 }
462
463 #define IP_IDENTS_SZ 2048u
464
465 static atomic_t *ip_idents __read_mostly;
466 static u32 *ip_tstamps __read_mostly;
467
468 /* In order to protect privacy, we add a perturbation to identifiers
469 * if one generator is seldom used. This makes hard for an attacker
470 * to infer how many packets were sent between two points in time.
471 */
472 u32 ip_idents_reserve(u32 hash, int segs)
473 {
474 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
475 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
476 u32 old = ACCESS_ONCE(*p_tstamp);
477 u32 now = (u32)jiffies;
478 u32 delta = 0;
479
480 if (old != now && cmpxchg(p_tstamp, old, now) == old)
481 delta = prandom_u32_max(now - old);
482
483 return atomic_add_return(segs + delta, p_id) - segs;
484 }
485 EXPORT_SYMBOL(ip_idents_reserve);
486
487 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
488 {
489 static u32 ip_idents_hashrnd __read_mostly;
490 u32 hash, id;
491
492 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
493
494 hash = jhash_3words((__force u32)iph->daddr,
495 (__force u32)iph->saddr,
496 iph->protocol ^ net_hash_mix(net),
497 ip_idents_hashrnd);
498 id = ip_idents_reserve(hash, segs);
499 iph->id = htons(id);
500 }
501 EXPORT_SYMBOL(__ip_select_ident);
502
503 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
504 const struct iphdr *iph,
505 int oif, u8 tos,
506 u8 prot, u32 mark, int flow_flags)
507 {
508 if (sk) {
509 const struct inet_sock *inet = inet_sk(sk);
510
511 oif = sk->sk_bound_dev_if;
512 mark = sk->sk_mark;
513 tos = RT_CONN_FLAGS(sk);
514 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
515 }
516 flowi4_init_output(fl4, oif, mark, tos,
517 RT_SCOPE_UNIVERSE, prot,
518 flow_flags,
519 iph->daddr, iph->saddr, 0, 0);
520 }
521
522 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
523 const struct sock *sk)
524 {
525 const struct iphdr *iph = ip_hdr(skb);
526 int oif = skb->dev->ifindex;
527 u8 tos = RT_TOS(iph->tos);
528 u8 prot = iph->protocol;
529 u32 mark = skb->mark;
530
531 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
532 }
533
534 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
535 {
536 const struct inet_sock *inet = inet_sk(sk);
537 const struct ip_options_rcu *inet_opt;
538 __be32 daddr = inet->inet_daddr;
539
540 rcu_read_lock();
541 inet_opt = rcu_dereference(inet->inet_opt);
542 if (inet_opt && inet_opt->opt.srr)
543 daddr = inet_opt->opt.faddr;
544 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
545 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
546 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
547 inet_sk_flowi_flags(sk),
548 daddr, inet->inet_saddr, 0, 0);
549 rcu_read_unlock();
550 }
551
552 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
553 const struct sk_buff *skb)
554 {
555 if (skb)
556 build_skb_flow_key(fl4, skb, sk);
557 else
558 build_sk_flow_key(fl4, sk);
559 }
560
561 static inline void rt_free(struct rtable *rt)
562 {
563 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
564 }
565
566 static DEFINE_SPINLOCK(fnhe_lock);
567
568 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
569 {
570 struct rtable *rt;
571
572 rt = rcu_dereference(fnhe->fnhe_rth_input);
573 if (rt) {
574 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
575 rt_free(rt);
576 }
577 rt = rcu_dereference(fnhe->fnhe_rth_output);
578 if (rt) {
579 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
580 rt_free(rt);
581 }
582 }
583
584 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
585 {
586 struct fib_nh_exception *fnhe, *oldest;
587
588 oldest = rcu_dereference(hash->chain);
589 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
590 fnhe = rcu_dereference(fnhe->fnhe_next)) {
591 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
592 oldest = fnhe;
593 }
594 fnhe_flush_routes(oldest);
595 return oldest;
596 }
597
598 static inline u32 fnhe_hashfun(__be32 daddr)
599 {
600 static u32 fnhe_hashrnd __read_mostly;
601 u32 hval;
602
603 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
604 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
605 return hash_32(hval, FNHE_HASH_SHIFT);
606 }
607
608 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
609 {
610 rt->rt_pmtu = fnhe->fnhe_pmtu;
611 rt->dst.expires = fnhe->fnhe_expires;
612
613 if (fnhe->fnhe_gw) {
614 rt->rt_flags |= RTCF_REDIRECTED;
615 rt->rt_gateway = fnhe->fnhe_gw;
616 rt->rt_uses_gateway = 1;
617 }
618 }
619
620 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
621 u32 pmtu, unsigned long expires)
622 {
623 struct fnhe_hash_bucket *hash;
624 struct fib_nh_exception *fnhe;
625 struct rtable *rt;
626 unsigned int i;
627 int depth;
628 u32 hval = fnhe_hashfun(daddr);
629
630 spin_lock_bh(&fnhe_lock);
631
632 hash = rcu_dereference(nh->nh_exceptions);
633 if (!hash) {
634 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
635 if (!hash)
636 goto out_unlock;
637 rcu_assign_pointer(nh->nh_exceptions, hash);
638 }
639
640 hash += hval;
641
642 depth = 0;
643 for (fnhe = rcu_dereference(hash->chain); fnhe;
644 fnhe = rcu_dereference(fnhe->fnhe_next)) {
645 if (fnhe->fnhe_daddr == daddr)
646 break;
647 depth++;
648 }
649
650 if (fnhe) {
651 if (gw)
652 fnhe->fnhe_gw = gw;
653 if (pmtu) {
654 fnhe->fnhe_pmtu = pmtu;
655 fnhe->fnhe_expires = max(1UL, expires);
656 }
657 /* Update all cached dsts too */
658 rt = rcu_dereference(fnhe->fnhe_rth_input);
659 if (rt)
660 fill_route_from_fnhe(rt, fnhe);
661 rt = rcu_dereference(fnhe->fnhe_rth_output);
662 if (rt)
663 fill_route_from_fnhe(rt, fnhe);
664 } else {
665 if (depth > FNHE_RECLAIM_DEPTH)
666 fnhe = fnhe_oldest(hash);
667 else {
668 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
669 if (!fnhe)
670 goto out_unlock;
671
672 fnhe->fnhe_next = hash->chain;
673 rcu_assign_pointer(hash->chain, fnhe);
674 }
675 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
676 fnhe->fnhe_daddr = daddr;
677 fnhe->fnhe_gw = gw;
678 fnhe->fnhe_pmtu = pmtu;
679 fnhe->fnhe_expires = expires;
680
681 /* Exception created; mark the cached routes for the nexthop
682 * stale, so anyone caching it rechecks if this exception
683 * applies to them.
684 */
685 rt = rcu_dereference(nh->nh_rth_input);
686 if (rt)
687 rt->dst.obsolete = DST_OBSOLETE_KILL;
688
689 for_each_possible_cpu(i) {
690 struct rtable __rcu **prt;
691 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
692 rt = rcu_dereference(*prt);
693 if (rt)
694 rt->dst.obsolete = DST_OBSOLETE_KILL;
695 }
696 }
697
698 fnhe->fnhe_stamp = jiffies;
699
700 out_unlock:
701 spin_unlock_bh(&fnhe_lock);
702 }
703
704 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
705 bool kill_route)
706 {
707 __be32 new_gw = icmp_hdr(skb)->un.gateway;
708 __be32 old_gw = ip_hdr(skb)->saddr;
709 struct net_device *dev = skb->dev;
710 struct in_device *in_dev;
711 struct fib_result res;
712 struct neighbour *n;
713 struct net *net;
714
715 switch (icmp_hdr(skb)->code & 7) {
716 case ICMP_REDIR_NET:
717 case ICMP_REDIR_NETTOS:
718 case ICMP_REDIR_HOST:
719 case ICMP_REDIR_HOSTTOS:
720 break;
721
722 default:
723 return;
724 }
725
726 if (rt->rt_gateway != old_gw)
727 return;
728
729 in_dev = __in_dev_get_rcu(dev);
730 if (!in_dev)
731 return;
732
733 net = dev_net(dev);
734 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
735 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
736 ipv4_is_zeronet(new_gw))
737 goto reject_redirect;
738
739 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
740 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
741 goto reject_redirect;
742 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
743 goto reject_redirect;
744 } else {
745 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
746 goto reject_redirect;
747 }
748
749 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
750 if (!IS_ERR(n)) {
751 if (!(n->nud_state & NUD_VALID)) {
752 neigh_event_send(n, NULL);
753 } else {
754 if (fib_lookup(net, fl4, &res, 0) == 0) {
755 struct fib_nh *nh = &FIB_RES_NH(res);
756
757 update_or_create_fnhe(nh, fl4->daddr, new_gw,
758 0, 0);
759 }
760 if (kill_route)
761 rt->dst.obsolete = DST_OBSOLETE_KILL;
762 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
763 }
764 neigh_release(n);
765 }
766 return;
767
768 reject_redirect:
769 #ifdef CONFIG_IP_ROUTE_VERBOSE
770 if (IN_DEV_LOG_MARTIANS(in_dev)) {
771 const struct iphdr *iph = (const struct iphdr *) skb->data;
772 __be32 daddr = iph->daddr;
773 __be32 saddr = iph->saddr;
774
775 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
776 " Advised path = %pI4 -> %pI4\n",
777 &old_gw, dev->name, &new_gw,
778 &saddr, &daddr);
779 }
780 #endif
781 ;
782 }
783
784 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
785 {
786 struct rtable *rt;
787 struct flowi4 fl4;
788 const struct iphdr *iph = (const struct iphdr *) skb->data;
789 int oif = skb->dev->ifindex;
790 u8 tos = RT_TOS(iph->tos);
791 u8 prot = iph->protocol;
792 u32 mark = skb->mark;
793
794 rt = (struct rtable *) dst;
795
796 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
797 __ip_do_redirect(rt, skb, &fl4, true);
798 }
799
800 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
801 {
802 struct rtable *rt = (struct rtable *)dst;
803 struct dst_entry *ret = dst;
804
805 if (rt) {
806 if (dst->obsolete > 0) {
807 ip_rt_put(rt);
808 ret = NULL;
809 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
810 rt->dst.expires) {
811 ip_rt_put(rt);
812 ret = NULL;
813 }
814 }
815 return ret;
816 }
817
818 /*
819 * Algorithm:
820 * 1. The first ip_rt_redirect_number redirects are sent
821 * with exponential backoff, then we stop sending them at all,
822 * assuming that the host ignores our redirects.
823 * 2. If we did not see packets requiring redirects
824 * during ip_rt_redirect_silence, we assume that the host
825 * forgot redirected route and start to send redirects again.
826 *
827 * This algorithm is much cheaper and more intelligent than dumb load limiting
828 * in icmp.c.
829 *
830 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
831 * and "frag. need" (breaks PMTU discovery) in icmp.c.
832 */
833
834 void ip_rt_send_redirect(struct sk_buff *skb)
835 {
836 struct rtable *rt = skb_rtable(skb);
837 struct in_device *in_dev;
838 struct inet_peer *peer;
839 struct net *net;
840 int log_martians;
841 int vif;
842
843 rcu_read_lock();
844 in_dev = __in_dev_get_rcu(rt->dst.dev);
845 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
846 rcu_read_unlock();
847 return;
848 }
849 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
850 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
851 rcu_read_unlock();
852
853 net = dev_net(rt->dst.dev);
854 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
855 if (!peer) {
856 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
857 rt_nexthop(rt, ip_hdr(skb)->daddr));
858 return;
859 }
860
861 /* No redirected packets during ip_rt_redirect_silence;
862 * reset the algorithm.
863 */
864 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
865 peer->rate_tokens = 0;
866
867 /* Too many ignored redirects; do not send anything
868 * set dst.rate_last to the last seen redirected packet.
869 */
870 if (peer->rate_tokens >= ip_rt_redirect_number) {
871 peer->rate_last = jiffies;
872 goto out_put_peer;
873 }
874
875 /* Check for load limit; set rate_last to the latest sent
876 * redirect.
877 */
878 if (peer->rate_tokens == 0 ||
879 time_after(jiffies,
880 (peer->rate_last +
881 (ip_rt_redirect_load << peer->rate_tokens)))) {
882 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
883
884 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
885 peer->rate_last = jiffies;
886 ++peer->rate_tokens;
887 #ifdef CONFIG_IP_ROUTE_VERBOSE
888 if (log_martians &&
889 peer->rate_tokens == ip_rt_redirect_number)
890 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
891 &ip_hdr(skb)->saddr, inet_iif(skb),
892 &ip_hdr(skb)->daddr, &gw);
893 #endif
894 }
895 out_put_peer:
896 inet_putpeer(peer);
897 }
898
899 static int ip_error(struct sk_buff *skb)
900 {
901 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
902 struct rtable *rt = skb_rtable(skb);
903 struct inet_peer *peer;
904 unsigned long now;
905 struct net *net;
906 bool send;
907 int code;
908
909 /* IP on this device is disabled. */
910 if (!in_dev)
911 goto out;
912
913 net = dev_net(rt->dst.dev);
914 if (!IN_DEV_FORWARD(in_dev)) {
915 switch (rt->dst.error) {
916 case EHOSTUNREACH:
917 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
918 break;
919
920 case ENETUNREACH:
921 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
922 break;
923 }
924 goto out;
925 }
926
927 switch (rt->dst.error) {
928 case EINVAL:
929 default:
930 goto out;
931 case EHOSTUNREACH:
932 code = ICMP_HOST_UNREACH;
933 break;
934 case ENETUNREACH:
935 code = ICMP_NET_UNREACH;
936 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
937 break;
938 case EACCES:
939 code = ICMP_PKT_FILTERED;
940 break;
941 }
942
943 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
944 l3mdev_master_ifindex(skb->dev), 1);
945
946 send = true;
947 if (peer) {
948 now = jiffies;
949 peer->rate_tokens += now - peer->rate_last;
950 if (peer->rate_tokens > ip_rt_error_burst)
951 peer->rate_tokens = ip_rt_error_burst;
952 peer->rate_last = now;
953 if (peer->rate_tokens >= ip_rt_error_cost)
954 peer->rate_tokens -= ip_rt_error_cost;
955 else
956 send = false;
957 inet_putpeer(peer);
958 }
959 if (send)
960 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
961
962 out: kfree_skb(skb);
963 return 0;
964 }
965
966 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
967 {
968 struct dst_entry *dst = &rt->dst;
969 struct fib_result res;
970
971 if (dst_metric_locked(dst, RTAX_MTU))
972 return;
973
974 if (ipv4_mtu(dst) < mtu)
975 return;
976
977 if (mtu < ip_rt_min_pmtu)
978 mtu = ip_rt_min_pmtu;
979
980 if (rt->rt_pmtu == mtu &&
981 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
982 return;
983
984 rcu_read_lock();
985 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
986 struct fib_nh *nh = &FIB_RES_NH(res);
987
988 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
989 jiffies + ip_rt_mtu_expires);
990 }
991 rcu_read_unlock();
992 }
993
994 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
995 struct sk_buff *skb, u32 mtu)
996 {
997 struct rtable *rt = (struct rtable *) dst;
998 struct flowi4 fl4;
999
1000 ip_rt_build_flow_key(&fl4, sk, skb);
1001 __ip_rt_update_pmtu(rt, &fl4, mtu);
1002 }
1003
1004 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1005 int oif, u32 mark, u8 protocol, int flow_flags)
1006 {
1007 const struct iphdr *iph = (const struct iphdr *) skb->data;
1008 struct flowi4 fl4;
1009 struct rtable *rt;
1010
1011 if (!mark)
1012 mark = IP4_REPLY_MARK(net, skb->mark);
1013
1014 __build_flow_key(&fl4, NULL, iph, oif,
1015 RT_TOS(iph->tos), protocol, mark, flow_flags);
1016 rt = __ip_route_output_key(net, &fl4);
1017 if (!IS_ERR(rt)) {
1018 __ip_rt_update_pmtu(rt, &fl4, mtu);
1019 ip_rt_put(rt);
1020 }
1021 }
1022 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1023
1024 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1025 {
1026 const struct iphdr *iph = (const struct iphdr *) skb->data;
1027 struct flowi4 fl4;
1028 struct rtable *rt;
1029
1030 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1031
1032 if (!fl4.flowi4_mark)
1033 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1034
1035 rt = __ip_route_output_key(sock_net(sk), &fl4);
1036 if (!IS_ERR(rt)) {
1037 __ip_rt_update_pmtu(rt, &fl4, mtu);
1038 ip_rt_put(rt);
1039 }
1040 }
1041
1042 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1043 {
1044 const struct iphdr *iph = (const struct iphdr *) skb->data;
1045 struct flowi4 fl4;
1046 struct rtable *rt;
1047 struct dst_entry *odst = NULL;
1048 bool new = false;
1049
1050 bh_lock_sock(sk);
1051
1052 if (!ip_sk_accept_pmtu(sk))
1053 goto out;
1054
1055 odst = sk_dst_get(sk);
1056
1057 if (sock_owned_by_user(sk) || !odst) {
1058 __ipv4_sk_update_pmtu(skb, sk, mtu);
1059 goto out;
1060 }
1061
1062 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1063
1064 rt = (struct rtable *)odst;
1065 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1066 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1067 if (IS_ERR(rt))
1068 goto out;
1069
1070 new = true;
1071 }
1072
1073 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1074
1075 if (!dst_check(&rt->dst, 0)) {
1076 if (new)
1077 dst_release(&rt->dst);
1078
1079 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1080 if (IS_ERR(rt))
1081 goto out;
1082
1083 new = true;
1084 }
1085
1086 if (new)
1087 sk_dst_set(sk, &rt->dst);
1088
1089 out:
1090 bh_unlock_sock(sk);
1091 dst_release(odst);
1092 }
1093 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1094
1095 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1096 int oif, u32 mark, u8 protocol, int flow_flags)
1097 {
1098 const struct iphdr *iph = (const struct iphdr *) skb->data;
1099 struct flowi4 fl4;
1100 struct rtable *rt;
1101
1102 __build_flow_key(&fl4, NULL, iph, oif,
1103 RT_TOS(iph->tos), protocol, mark, flow_flags);
1104 rt = __ip_route_output_key(net, &fl4);
1105 if (!IS_ERR(rt)) {
1106 __ip_do_redirect(rt, skb, &fl4, false);
1107 ip_rt_put(rt);
1108 }
1109 }
1110 EXPORT_SYMBOL_GPL(ipv4_redirect);
1111
1112 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1113 {
1114 const struct iphdr *iph = (const struct iphdr *) skb->data;
1115 struct flowi4 fl4;
1116 struct rtable *rt;
1117
1118 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1119 rt = __ip_route_output_key(sock_net(sk), &fl4);
1120 if (!IS_ERR(rt)) {
1121 __ip_do_redirect(rt, skb, &fl4, false);
1122 ip_rt_put(rt);
1123 }
1124 }
1125 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1126
1127 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1128 {
1129 struct rtable *rt = (struct rtable *) dst;
1130
1131 /* All IPV4 dsts are created with ->obsolete set to the value
1132 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1133 * into this function always.
1134 *
1135 * When a PMTU/redirect information update invalidates a route,
1136 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1137 * DST_OBSOLETE_DEAD by dst_free().
1138 */
1139 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1140 return NULL;
1141 return dst;
1142 }
1143
1144 static void ipv4_link_failure(struct sk_buff *skb)
1145 {
1146 struct rtable *rt;
1147
1148 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1149
1150 rt = skb_rtable(skb);
1151 if (rt)
1152 dst_set_expires(&rt->dst, 0);
1153 }
1154
1155 static int ip_rt_bug(struct sock *sk, struct sk_buff *skb)
1156 {
1157 pr_debug("%s: %pI4 -> %pI4, %s\n",
1158 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1159 skb->dev ? skb->dev->name : "?");
1160 kfree_skb(skb);
1161 WARN_ON(1);
1162 return 0;
1163 }
1164
1165 /*
1166 We do not cache source address of outgoing interface,
1167 because it is used only by IP RR, TS and SRR options,
1168 so that it out of fast path.
1169
1170 BTW remember: "addr" is allowed to be not aligned
1171 in IP options!
1172 */
1173
1174 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1175 {
1176 __be32 src;
1177
1178 if (rt_is_output_route(rt))
1179 src = ip_hdr(skb)->saddr;
1180 else {
1181 struct fib_result res;
1182 struct flowi4 fl4;
1183 struct iphdr *iph;
1184
1185 iph = ip_hdr(skb);
1186
1187 memset(&fl4, 0, sizeof(fl4));
1188 fl4.daddr = iph->daddr;
1189 fl4.saddr = iph->saddr;
1190 fl4.flowi4_tos = RT_TOS(iph->tos);
1191 fl4.flowi4_oif = rt->dst.dev->ifindex;
1192 fl4.flowi4_iif = skb->dev->ifindex;
1193 fl4.flowi4_mark = skb->mark;
1194
1195 rcu_read_lock();
1196 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1197 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1198 else
1199 src = inet_select_addr(rt->dst.dev,
1200 rt_nexthop(rt, iph->daddr),
1201 RT_SCOPE_UNIVERSE);
1202 rcu_read_unlock();
1203 }
1204 memcpy(addr, &src, 4);
1205 }
1206
1207 #ifdef CONFIG_IP_ROUTE_CLASSID
1208 static void set_class_tag(struct rtable *rt, u32 tag)
1209 {
1210 if (!(rt->dst.tclassid & 0xFFFF))
1211 rt->dst.tclassid |= tag & 0xFFFF;
1212 if (!(rt->dst.tclassid & 0xFFFF0000))
1213 rt->dst.tclassid |= tag & 0xFFFF0000;
1214 }
1215 #endif
1216
1217 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1218 {
1219 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1220
1221 if (advmss == 0) {
1222 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1223 ip_rt_min_advmss);
1224 if (advmss > 65535 - 40)
1225 advmss = 65535 - 40;
1226 }
1227 return advmss;
1228 }
1229
1230 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1231 {
1232 const struct rtable *rt = (const struct rtable *) dst;
1233 unsigned int mtu = rt->rt_pmtu;
1234
1235 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1236 mtu = dst_metric_raw(dst, RTAX_MTU);
1237
1238 if (mtu)
1239 return mtu;
1240
1241 mtu = dst->dev->mtu;
1242
1243 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1244 if (rt->rt_uses_gateway && mtu > 576)
1245 mtu = 576;
1246 }
1247
1248 return min_t(unsigned int, mtu, IP_MAX_MTU);
1249 }
1250
1251 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1252 {
1253 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1254 struct fib_nh_exception *fnhe;
1255 u32 hval;
1256
1257 if (!hash)
1258 return NULL;
1259
1260 hval = fnhe_hashfun(daddr);
1261
1262 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1263 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1264 if (fnhe->fnhe_daddr == daddr)
1265 return fnhe;
1266 }
1267 return NULL;
1268 }
1269
1270 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1271 __be32 daddr)
1272 {
1273 bool ret = false;
1274
1275 spin_lock_bh(&fnhe_lock);
1276
1277 if (daddr == fnhe->fnhe_daddr) {
1278 struct rtable __rcu **porig;
1279 struct rtable *orig;
1280 int genid = fnhe_genid(dev_net(rt->dst.dev));
1281
1282 if (rt_is_input_route(rt))
1283 porig = &fnhe->fnhe_rth_input;
1284 else
1285 porig = &fnhe->fnhe_rth_output;
1286 orig = rcu_dereference(*porig);
1287
1288 if (fnhe->fnhe_genid != genid) {
1289 fnhe->fnhe_genid = genid;
1290 fnhe->fnhe_gw = 0;
1291 fnhe->fnhe_pmtu = 0;
1292 fnhe->fnhe_expires = 0;
1293 fnhe_flush_routes(fnhe);
1294 orig = NULL;
1295 }
1296 fill_route_from_fnhe(rt, fnhe);
1297 if (!rt->rt_gateway)
1298 rt->rt_gateway = daddr;
1299
1300 if (!(rt->dst.flags & DST_NOCACHE)) {
1301 rcu_assign_pointer(*porig, rt);
1302 if (orig)
1303 rt_free(orig);
1304 ret = true;
1305 }
1306
1307 fnhe->fnhe_stamp = jiffies;
1308 }
1309 spin_unlock_bh(&fnhe_lock);
1310
1311 return ret;
1312 }
1313
1314 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1315 {
1316 struct rtable *orig, *prev, **p;
1317 bool ret = true;
1318
1319 if (rt_is_input_route(rt)) {
1320 p = (struct rtable **)&nh->nh_rth_input;
1321 } else {
1322 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1323 }
1324 orig = *p;
1325
1326 prev = cmpxchg(p, orig, rt);
1327 if (prev == orig) {
1328 if (orig)
1329 rt_free(orig);
1330 } else
1331 ret = false;
1332
1333 return ret;
1334 }
1335
1336 struct uncached_list {
1337 spinlock_t lock;
1338 struct list_head head;
1339 };
1340
1341 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1342
1343 static void rt_add_uncached_list(struct rtable *rt)
1344 {
1345 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1346
1347 rt->rt_uncached_list = ul;
1348
1349 spin_lock_bh(&ul->lock);
1350 list_add_tail(&rt->rt_uncached, &ul->head);
1351 spin_unlock_bh(&ul->lock);
1352 }
1353
1354 static void ipv4_dst_destroy(struct dst_entry *dst)
1355 {
1356 struct rtable *rt = (struct rtable *) dst;
1357
1358 if (!list_empty(&rt->rt_uncached)) {
1359 struct uncached_list *ul = rt->rt_uncached_list;
1360
1361 spin_lock_bh(&ul->lock);
1362 list_del(&rt->rt_uncached);
1363 spin_unlock_bh(&ul->lock);
1364 }
1365 }
1366
1367 void rt_flush_dev(struct net_device *dev)
1368 {
1369 struct net *net = dev_net(dev);
1370 struct rtable *rt;
1371 int cpu;
1372
1373 for_each_possible_cpu(cpu) {
1374 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1375
1376 spin_lock_bh(&ul->lock);
1377 list_for_each_entry(rt, &ul->head, rt_uncached) {
1378 if (rt->dst.dev != dev)
1379 continue;
1380 rt->dst.dev = net->loopback_dev;
1381 dev_hold(rt->dst.dev);
1382 dev_put(dev);
1383 }
1384 spin_unlock_bh(&ul->lock);
1385 }
1386 }
1387
1388 static bool rt_cache_valid(const struct rtable *rt)
1389 {
1390 return rt &&
1391 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1392 !rt_is_expired(rt);
1393 }
1394
1395 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1396 const struct fib_result *res,
1397 struct fib_nh_exception *fnhe,
1398 struct fib_info *fi, u16 type, u32 itag)
1399 {
1400 bool cached = false;
1401
1402 if (fi) {
1403 struct fib_nh *nh = &FIB_RES_NH(*res);
1404
1405 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1406 rt->rt_gateway = nh->nh_gw;
1407 rt->rt_uses_gateway = 1;
1408 }
1409 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1410 #ifdef CONFIG_IP_ROUTE_CLASSID
1411 rt->dst.tclassid = nh->nh_tclassid;
1412 #endif
1413 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
1414 if (unlikely(fnhe))
1415 cached = rt_bind_exception(rt, fnhe, daddr);
1416 else if (!(rt->dst.flags & DST_NOCACHE))
1417 cached = rt_cache_route(nh, rt);
1418 if (unlikely(!cached)) {
1419 /* Routes we intend to cache in nexthop exception or
1420 * FIB nexthop have the DST_NOCACHE bit clear.
1421 * However, if we are unsuccessful at storing this
1422 * route into the cache we really need to set it.
1423 */
1424 rt->dst.flags |= DST_NOCACHE;
1425 if (!rt->rt_gateway)
1426 rt->rt_gateway = daddr;
1427 rt_add_uncached_list(rt);
1428 }
1429 } else
1430 rt_add_uncached_list(rt);
1431
1432 #ifdef CONFIG_IP_ROUTE_CLASSID
1433 #ifdef CONFIG_IP_MULTIPLE_TABLES
1434 set_class_tag(rt, res->tclassid);
1435 #endif
1436 set_class_tag(rt, itag);
1437 #endif
1438 }
1439
1440 static struct rtable *rt_dst_alloc(struct net_device *dev,
1441 unsigned int flags, u16 type,
1442 bool nopolicy, bool noxfrm, bool will_cache)
1443 {
1444 struct rtable *rt;
1445
1446 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1447 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1448 (nopolicy ? DST_NOPOLICY : 0) |
1449 (noxfrm ? DST_NOXFRM : 0));
1450
1451 if (rt) {
1452 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1453 rt->rt_flags = flags;
1454 rt->rt_type = type;
1455 rt->rt_is_input = 0;
1456 rt->rt_iif = 0;
1457 rt->rt_pmtu = 0;
1458 rt->rt_gateway = 0;
1459 rt->rt_uses_gateway = 0;
1460 rt->rt_table_id = 0;
1461 INIT_LIST_HEAD(&rt->rt_uncached);
1462
1463 rt->dst.output = ip_output;
1464 if (flags & RTCF_LOCAL)
1465 rt->dst.input = ip_local_deliver;
1466 }
1467
1468 return rt;
1469 }
1470
1471 /* called in rcu_read_lock() section */
1472 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1473 u8 tos, struct net_device *dev, int our)
1474 {
1475 struct rtable *rth;
1476 struct in_device *in_dev = __in_dev_get_rcu(dev);
1477 unsigned int flags = RTCF_MULTICAST;
1478 u32 itag = 0;
1479 int err;
1480
1481 /* Primary sanity checks. */
1482
1483 if (!in_dev)
1484 return -EINVAL;
1485
1486 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1487 skb->protocol != htons(ETH_P_IP))
1488 goto e_inval;
1489
1490 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1491 goto e_inval;
1492
1493 if (ipv4_is_zeronet(saddr)) {
1494 if (!ipv4_is_local_multicast(daddr))
1495 goto e_inval;
1496 } else {
1497 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1498 in_dev, &itag);
1499 if (err < 0)
1500 goto e_err;
1501 }
1502 if (our)
1503 flags |= RTCF_LOCAL;
1504
1505 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1506 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1507 if (!rth)
1508 goto e_nobufs;
1509
1510 #ifdef CONFIG_IP_ROUTE_CLASSID
1511 rth->dst.tclassid = itag;
1512 #endif
1513 rth->dst.output = ip_rt_bug;
1514 rth->rt_is_input= 1;
1515
1516 #ifdef CONFIG_IP_MROUTE
1517 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1518 rth->dst.input = ip_mr_input;
1519 #endif
1520 RT_CACHE_STAT_INC(in_slow_mc);
1521
1522 skb_dst_set(skb, &rth->dst);
1523 return 0;
1524
1525 e_nobufs:
1526 return -ENOBUFS;
1527 e_inval:
1528 return -EINVAL;
1529 e_err:
1530 return err;
1531 }
1532
1533
1534 static void ip_handle_martian_source(struct net_device *dev,
1535 struct in_device *in_dev,
1536 struct sk_buff *skb,
1537 __be32 daddr,
1538 __be32 saddr)
1539 {
1540 RT_CACHE_STAT_INC(in_martian_src);
1541 #ifdef CONFIG_IP_ROUTE_VERBOSE
1542 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1543 /*
1544 * RFC1812 recommendation, if source is martian,
1545 * the only hint is MAC header.
1546 */
1547 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1548 &daddr, &saddr, dev->name);
1549 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1550 print_hex_dump(KERN_WARNING, "ll header: ",
1551 DUMP_PREFIX_OFFSET, 16, 1,
1552 skb_mac_header(skb),
1553 dev->hard_header_len, true);
1554 }
1555 }
1556 #endif
1557 }
1558
1559 /* called in rcu_read_lock() section */
1560 static int __mkroute_input(struct sk_buff *skb,
1561 const struct fib_result *res,
1562 struct in_device *in_dev,
1563 __be32 daddr, __be32 saddr, u32 tos)
1564 {
1565 struct fib_nh_exception *fnhe;
1566 struct rtable *rth;
1567 int err;
1568 struct in_device *out_dev;
1569 bool do_cache;
1570 u32 itag = 0;
1571
1572 /* get a working reference to the output device */
1573 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1574 if (!out_dev) {
1575 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1576 return -EINVAL;
1577 }
1578
1579 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1580 in_dev->dev, in_dev, &itag);
1581 if (err < 0) {
1582 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1583 saddr);
1584
1585 goto cleanup;
1586 }
1587
1588 do_cache = res->fi && !itag;
1589 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1590 skb->protocol == htons(ETH_P_IP) &&
1591 (IN_DEV_SHARED_MEDIA(out_dev) ||
1592 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1593 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1594
1595 if (skb->protocol != htons(ETH_P_IP)) {
1596 /* Not IP (i.e. ARP). Do not create route, if it is
1597 * invalid for proxy arp. DNAT routes are always valid.
1598 *
1599 * Proxy arp feature have been extended to allow, ARP
1600 * replies back to the same interface, to support
1601 * Private VLAN switch technologies. See arp.c.
1602 */
1603 if (out_dev == in_dev &&
1604 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1605 err = -EINVAL;
1606 goto cleanup;
1607 }
1608 }
1609
1610 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1611 if (do_cache) {
1612 if (fnhe)
1613 rth = rcu_dereference(fnhe->fnhe_rth_input);
1614 else
1615 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1616
1617 if (rt_cache_valid(rth)) {
1618 skb_dst_set_noref(skb, &rth->dst);
1619 goto out;
1620 }
1621 }
1622
1623 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1624 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1625 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1626 if (!rth) {
1627 err = -ENOBUFS;
1628 goto cleanup;
1629 }
1630
1631 rth->rt_is_input = 1;
1632 if (res->table)
1633 rth->rt_table_id = res->table->tb_id;
1634 RT_CACHE_STAT_INC(in_slow_tot);
1635
1636 rth->dst.input = ip_forward;
1637
1638 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1639 if (lwtunnel_output_redirect(rth->dst.lwtstate)) {
1640 rth->dst.lwtstate->orig_output = rth->dst.output;
1641 rth->dst.output = lwtunnel_output;
1642 }
1643 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
1644 rth->dst.lwtstate->orig_input = rth->dst.input;
1645 rth->dst.input = lwtunnel_input;
1646 }
1647 skb_dst_set(skb, &rth->dst);
1648 out:
1649 err = 0;
1650 cleanup:
1651 return err;
1652 }
1653
1654 static int ip_mkroute_input(struct sk_buff *skb,
1655 struct fib_result *res,
1656 const struct flowi4 *fl4,
1657 struct in_device *in_dev,
1658 __be32 daddr, __be32 saddr, u32 tos)
1659 {
1660 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1661 if (res->fi && res->fi->fib_nhs > 1) {
1662 int h;
1663
1664 h = fib_multipath_hash(saddr, daddr);
1665 fib_select_multipath(res, h);
1666 }
1667 #endif
1668
1669 /* create a routing cache entry */
1670 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1671 }
1672
1673 /*
1674 * NOTE. We drop all the packets that has local source
1675 * addresses, because every properly looped back packet
1676 * must have correct destination already attached by output routine.
1677 *
1678 * Such approach solves two big problems:
1679 * 1. Not simplex devices are handled properly.
1680 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1681 * called with rcu_read_lock()
1682 */
1683
1684 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1685 u8 tos, struct net_device *dev)
1686 {
1687 struct fib_result res;
1688 struct in_device *in_dev = __in_dev_get_rcu(dev);
1689 struct ip_tunnel_info *tun_info;
1690 struct flowi4 fl4;
1691 unsigned int flags = 0;
1692 u32 itag = 0;
1693 struct rtable *rth;
1694 int err = -EINVAL;
1695 struct net *net = dev_net(dev);
1696 bool do_cache;
1697
1698 /* IP on this device is disabled. */
1699
1700 if (!in_dev)
1701 goto out;
1702
1703 /* Check for the most weird martians, which can be not detected
1704 by fib_lookup.
1705 */
1706
1707 tun_info = skb_tunnel_info(skb);
1708 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
1709 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
1710 else
1711 fl4.flowi4_tun_key.tun_id = 0;
1712 skb_dst_drop(skb);
1713
1714 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1715 goto martian_source;
1716
1717 res.fi = NULL;
1718 res.table = NULL;
1719 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1720 goto brd_input;
1721
1722 /* Accept zero addresses only to limited broadcast;
1723 * I even do not know to fix it or not. Waiting for complains :-)
1724 */
1725 if (ipv4_is_zeronet(saddr))
1726 goto martian_source;
1727
1728 if (ipv4_is_zeronet(daddr))
1729 goto martian_destination;
1730
1731 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1732 * and call it once if daddr or/and saddr are loopback addresses
1733 */
1734 if (ipv4_is_loopback(daddr)) {
1735 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1736 goto martian_destination;
1737 } else if (ipv4_is_loopback(saddr)) {
1738 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1739 goto martian_source;
1740 }
1741
1742 /*
1743 * Now we are ready to route packet.
1744 */
1745 fl4.flowi4_oif = 0;
1746 fl4.flowi4_iif = l3mdev_fib_oif_rcu(dev);
1747 fl4.flowi4_mark = skb->mark;
1748 fl4.flowi4_tos = tos;
1749 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1750 fl4.flowi4_flags = 0;
1751 fl4.daddr = daddr;
1752 fl4.saddr = saddr;
1753 err = fib_lookup(net, &fl4, &res, 0);
1754 if (err != 0) {
1755 if (!IN_DEV_FORWARD(in_dev))
1756 err = -EHOSTUNREACH;
1757 goto no_route;
1758 }
1759
1760 if (res.type == RTN_BROADCAST)
1761 goto brd_input;
1762
1763 if (res.type == RTN_LOCAL) {
1764 err = fib_validate_source(skb, saddr, daddr, tos,
1765 0, dev, in_dev, &itag);
1766 if (err < 0)
1767 goto martian_source;
1768 goto local_input;
1769 }
1770
1771 if (!IN_DEV_FORWARD(in_dev)) {
1772 err = -EHOSTUNREACH;
1773 goto no_route;
1774 }
1775 if (res.type != RTN_UNICAST)
1776 goto martian_destination;
1777
1778 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1779 out: return err;
1780
1781 brd_input:
1782 if (skb->protocol != htons(ETH_P_IP))
1783 goto e_inval;
1784
1785 if (!ipv4_is_zeronet(saddr)) {
1786 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1787 in_dev, &itag);
1788 if (err < 0)
1789 goto martian_source;
1790 }
1791 flags |= RTCF_BROADCAST;
1792 res.type = RTN_BROADCAST;
1793 RT_CACHE_STAT_INC(in_brd);
1794
1795 local_input:
1796 do_cache = false;
1797 if (res.fi) {
1798 if (!itag) {
1799 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1800 if (rt_cache_valid(rth)) {
1801 skb_dst_set_noref(skb, &rth->dst);
1802 err = 0;
1803 goto out;
1804 }
1805 do_cache = true;
1806 }
1807 }
1808
1809 rth = rt_dst_alloc(net->loopback_dev, flags | RTCF_LOCAL, res.type,
1810 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1811 if (!rth)
1812 goto e_nobufs;
1813
1814 rth->dst.output= ip_rt_bug;
1815 #ifdef CONFIG_IP_ROUTE_CLASSID
1816 rth->dst.tclassid = itag;
1817 #endif
1818 rth->rt_is_input = 1;
1819 if (res.table)
1820 rth->rt_table_id = res.table->tb_id;
1821
1822 RT_CACHE_STAT_INC(in_slow_tot);
1823 if (res.type == RTN_UNREACHABLE) {
1824 rth->dst.input= ip_error;
1825 rth->dst.error= -err;
1826 rth->rt_flags &= ~RTCF_LOCAL;
1827 }
1828 if (do_cache) {
1829 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1830 rth->dst.flags |= DST_NOCACHE;
1831 rt_add_uncached_list(rth);
1832 }
1833 }
1834 skb_dst_set(skb, &rth->dst);
1835 err = 0;
1836 goto out;
1837
1838 no_route:
1839 RT_CACHE_STAT_INC(in_no_route);
1840 res.type = RTN_UNREACHABLE;
1841 res.fi = NULL;
1842 res.table = NULL;
1843 goto local_input;
1844
1845 /*
1846 * Do not cache martian addresses: they should be logged (RFC1812)
1847 */
1848 martian_destination:
1849 RT_CACHE_STAT_INC(in_martian_dst);
1850 #ifdef CONFIG_IP_ROUTE_VERBOSE
1851 if (IN_DEV_LOG_MARTIANS(in_dev))
1852 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1853 &daddr, &saddr, dev->name);
1854 #endif
1855
1856 e_inval:
1857 err = -EINVAL;
1858 goto out;
1859
1860 e_nobufs:
1861 err = -ENOBUFS;
1862 goto out;
1863
1864 martian_source:
1865 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1866 goto out;
1867 }
1868
1869 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1870 u8 tos, struct net_device *dev)
1871 {
1872 int res;
1873
1874 rcu_read_lock();
1875
1876 /* Multicast recognition logic is moved from route cache to here.
1877 The problem was that too many Ethernet cards have broken/missing
1878 hardware multicast filters :-( As result the host on multicasting
1879 network acquires a lot of useless route cache entries, sort of
1880 SDR messages from all the world. Now we try to get rid of them.
1881 Really, provided software IP multicast filter is organized
1882 reasonably (at least, hashed), it does not result in a slowdown
1883 comparing with route cache reject entries.
1884 Note, that multicast routers are not affected, because
1885 route cache entry is created eventually.
1886 */
1887 if (ipv4_is_multicast(daddr)) {
1888 struct in_device *in_dev = __in_dev_get_rcu(dev);
1889
1890 if (in_dev) {
1891 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1892 ip_hdr(skb)->protocol);
1893 if (our
1894 #ifdef CONFIG_IP_MROUTE
1895 ||
1896 (!ipv4_is_local_multicast(daddr) &&
1897 IN_DEV_MFORWARD(in_dev))
1898 #endif
1899 ) {
1900 int res = ip_route_input_mc(skb, daddr, saddr,
1901 tos, dev, our);
1902 rcu_read_unlock();
1903 return res;
1904 }
1905 }
1906 rcu_read_unlock();
1907 return -EINVAL;
1908 }
1909 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1910 rcu_read_unlock();
1911 return res;
1912 }
1913 EXPORT_SYMBOL(ip_route_input_noref);
1914
1915 /* called with rcu_read_lock() */
1916 static struct rtable *__mkroute_output(const struct fib_result *res,
1917 const struct flowi4 *fl4, int orig_oif,
1918 struct net_device *dev_out,
1919 unsigned int flags)
1920 {
1921 struct fib_info *fi = res->fi;
1922 struct fib_nh_exception *fnhe;
1923 struct in_device *in_dev;
1924 u16 type = res->type;
1925 struct rtable *rth;
1926 bool do_cache;
1927
1928 in_dev = __in_dev_get_rcu(dev_out);
1929 if (!in_dev)
1930 return ERR_PTR(-EINVAL);
1931
1932 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1933 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1934 return ERR_PTR(-EINVAL);
1935
1936 if (ipv4_is_lbcast(fl4->daddr))
1937 type = RTN_BROADCAST;
1938 else if (ipv4_is_multicast(fl4->daddr))
1939 type = RTN_MULTICAST;
1940 else if (ipv4_is_zeronet(fl4->daddr))
1941 return ERR_PTR(-EINVAL);
1942
1943 if (dev_out->flags & IFF_LOOPBACK)
1944 flags |= RTCF_LOCAL;
1945
1946 do_cache = true;
1947 if (type == RTN_BROADCAST) {
1948 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1949 fi = NULL;
1950 } else if (type == RTN_MULTICAST) {
1951 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1952 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1953 fl4->flowi4_proto))
1954 flags &= ~RTCF_LOCAL;
1955 else
1956 do_cache = false;
1957 /* If multicast route do not exist use
1958 * default one, but do not gateway in this case.
1959 * Yes, it is hack.
1960 */
1961 if (fi && res->prefixlen < 4)
1962 fi = NULL;
1963 }
1964
1965 fnhe = NULL;
1966 do_cache &= fi != NULL;
1967 if (do_cache) {
1968 struct rtable __rcu **prth;
1969 struct fib_nh *nh = &FIB_RES_NH(*res);
1970
1971 fnhe = find_exception(nh, fl4->daddr);
1972 if (fnhe)
1973 prth = &fnhe->fnhe_rth_output;
1974 else {
1975 if (unlikely(fl4->flowi4_flags &
1976 FLOWI_FLAG_KNOWN_NH &&
1977 !(nh->nh_gw &&
1978 nh->nh_scope == RT_SCOPE_LINK))) {
1979 do_cache = false;
1980 goto add;
1981 }
1982 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
1983 }
1984 rth = rcu_dereference(*prth);
1985 if (rt_cache_valid(rth)) {
1986 dst_hold(&rth->dst);
1987 return rth;
1988 }
1989 }
1990
1991 add:
1992 rth = rt_dst_alloc(dev_out, flags, type,
1993 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1994 IN_DEV_CONF_GET(in_dev, NOXFRM),
1995 do_cache);
1996 if (!rth)
1997 return ERR_PTR(-ENOBUFS);
1998
1999 rth->rt_iif = orig_oif ? : 0;
2000 if (res->table)
2001 rth->rt_table_id = res->table->tb_id;
2002
2003 RT_CACHE_STAT_INC(out_slow_tot);
2004
2005 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2006 if (flags & RTCF_LOCAL &&
2007 !(dev_out->flags & IFF_LOOPBACK)) {
2008 rth->dst.output = ip_mc_output;
2009 RT_CACHE_STAT_INC(out_slow_mc);
2010 }
2011 #ifdef CONFIG_IP_MROUTE
2012 if (type == RTN_MULTICAST) {
2013 if (IN_DEV_MFORWARD(in_dev) &&
2014 !ipv4_is_local_multicast(fl4->daddr)) {
2015 rth->dst.input = ip_mr_input;
2016 rth->dst.output = ip_mc_output;
2017 }
2018 }
2019 #endif
2020 }
2021
2022 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
2023 if (lwtunnel_output_redirect(rth->dst.lwtstate))
2024 rth->dst.output = lwtunnel_output;
2025
2026 return rth;
2027 }
2028
2029 /*
2030 * Major route resolver routine.
2031 */
2032
2033 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
2034 {
2035 struct net_device *dev_out = NULL;
2036 __u8 tos = RT_FL_TOS(fl4);
2037 unsigned int flags = 0;
2038 struct fib_result res;
2039 struct rtable *rth;
2040 int orig_oif;
2041 int err = -ENETUNREACH;
2042
2043 res.tclassid = 0;
2044 res.fi = NULL;
2045 res.table = NULL;
2046
2047 orig_oif = fl4->flowi4_oif;
2048
2049 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2050 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2051 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2052 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2053
2054 rcu_read_lock();
2055 if (fl4->saddr) {
2056 rth = ERR_PTR(-EINVAL);
2057 if (ipv4_is_multicast(fl4->saddr) ||
2058 ipv4_is_lbcast(fl4->saddr) ||
2059 ipv4_is_zeronet(fl4->saddr))
2060 goto out;
2061
2062 /* I removed check for oif == dev_out->oif here.
2063 It was wrong for two reasons:
2064 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2065 is assigned to multiple interfaces.
2066 2. Moreover, we are allowed to send packets with saddr
2067 of another iface. --ANK
2068 */
2069
2070 if (fl4->flowi4_oif == 0 &&
2071 (ipv4_is_multicast(fl4->daddr) ||
2072 ipv4_is_lbcast(fl4->daddr))) {
2073 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2074 dev_out = __ip_dev_find(net, fl4->saddr, false);
2075 if (!dev_out)
2076 goto out;
2077
2078 /* Special hack: user can direct multicasts
2079 and limited broadcast via necessary interface
2080 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2081 This hack is not just for fun, it allows
2082 vic,vat and friends to work.
2083 They bind socket to loopback, set ttl to zero
2084 and expect that it will work.
2085 From the viewpoint of routing cache they are broken,
2086 because we are not allowed to build multicast path
2087 with loopback source addr (look, routing cache
2088 cannot know, that ttl is zero, so that packet
2089 will not leave this host and route is valid).
2090 Luckily, this hack is good workaround.
2091 */
2092
2093 fl4->flowi4_oif = dev_out->ifindex;
2094 goto make_route;
2095 }
2096
2097 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2098 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2099 if (!__ip_dev_find(net, fl4->saddr, false))
2100 goto out;
2101 }
2102 }
2103
2104
2105 if (fl4->flowi4_oif) {
2106 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2107 rth = ERR_PTR(-ENODEV);
2108 if (!dev_out)
2109 goto out;
2110
2111 /* RACE: Check return value of inet_select_addr instead. */
2112 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2113 rth = ERR_PTR(-ENETUNREACH);
2114 goto out;
2115 }
2116 if (ipv4_is_local_multicast(fl4->daddr) ||
2117 ipv4_is_lbcast(fl4->daddr) ||
2118 fl4->flowi4_proto == IPPROTO_IGMP) {
2119 if (!fl4->saddr)
2120 fl4->saddr = inet_select_addr(dev_out, 0,
2121 RT_SCOPE_LINK);
2122 goto make_route;
2123 }
2124 if (!fl4->saddr) {
2125 if (ipv4_is_multicast(fl4->daddr))
2126 fl4->saddr = inet_select_addr(dev_out, 0,
2127 fl4->flowi4_scope);
2128 else if (!fl4->daddr)
2129 fl4->saddr = inet_select_addr(dev_out, 0,
2130 RT_SCOPE_HOST);
2131 }
2132
2133 rth = l3mdev_get_rtable(dev_out, fl4);
2134 if (rth)
2135 goto out;
2136 }
2137
2138 if (!fl4->daddr) {
2139 fl4->daddr = fl4->saddr;
2140 if (!fl4->daddr)
2141 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2142 dev_out = net->loopback_dev;
2143 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2144 res.type = RTN_LOCAL;
2145 flags |= RTCF_LOCAL;
2146 goto make_route;
2147 }
2148
2149 err = fib_lookup(net, fl4, &res, 0);
2150 if (err) {
2151 res.fi = NULL;
2152 res.table = NULL;
2153 if (fl4->flowi4_oif) {
2154 /* Apparently, routing tables are wrong. Assume,
2155 that the destination is on link.
2156
2157 WHY? DW.
2158 Because we are allowed to send to iface
2159 even if it has NO routes and NO assigned
2160 addresses. When oif is specified, routing
2161 tables are looked up with only one purpose:
2162 to catch if destination is gatewayed, rather than
2163 direct. Moreover, if MSG_DONTROUTE is set,
2164 we send packet, ignoring both routing tables
2165 and ifaddr state. --ANK
2166
2167
2168 We could make it even if oif is unknown,
2169 likely IPv6, but we do not.
2170 */
2171
2172 if (fl4->saddr == 0)
2173 fl4->saddr = inet_select_addr(dev_out, 0,
2174 RT_SCOPE_LINK);
2175 res.type = RTN_UNICAST;
2176 goto make_route;
2177 }
2178 rth = ERR_PTR(err);
2179 goto out;
2180 }
2181
2182 if (res.type == RTN_LOCAL) {
2183 if (!fl4->saddr) {
2184 if (res.fi->fib_prefsrc)
2185 fl4->saddr = res.fi->fib_prefsrc;
2186 else
2187 fl4->saddr = fl4->daddr;
2188 }
2189 dev_out = net->loopback_dev;
2190 fl4->flowi4_oif = dev_out->ifindex;
2191 flags |= RTCF_LOCAL;
2192 goto make_route;
2193 }
2194
2195 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2196 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) {
2197 int h;
2198
2199 h = fib_multipath_hash(fl4->saddr, fl4->daddr);
2200 fib_select_multipath(&res, h);
2201 }
2202 else
2203 #endif
2204 if (!res.prefixlen &&
2205 res.table->tb_num_default > 1 &&
2206 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2207 fib_select_default(fl4, &res);
2208
2209 if (!fl4->saddr)
2210 fl4->saddr = FIB_RES_PREFSRC(net, res);
2211
2212 dev_out = FIB_RES_DEV(res);
2213 fl4->flowi4_oif = dev_out->ifindex;
2214
2215
2216 make_route:
2217 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2218
2219 out:
2220 rcu_read_unlock();
2221 return rth;
2222 }
2223 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2224
2225 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2226 {
2227 return NULL;
2228 }
2229
2230 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2231 {
2232 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2233
2234 return mtu ? : dst->dev->mtu;
2235 }
2236
2237 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2238 struct sk_buff *skb, u32 mtu)
2239 {
2240 }
2241
2242 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2243 struct sk_buff *skb)
2244 {
2245 }
2246
2247 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2248 unsigned long old)
2249 {
2250 return NULL;
2251 }
2252
2253 static struct dst_ops ipv4_dst_blackhole_ops = {
2254 .family = AF_INET,
2255 .check = ipv4_blackhole_dst_check,
2256 .mtu = ipv4_blackhole_mtu,
2257 .default_advmss = ipv4_default_advmss,
2258 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2259 .redirect = ipv4_rt_blackhole_redirect,
2260 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2261 .neigh_lookup = ipv4_neigh_lookup,
2262 };
2263
2264 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2265 {
2266 struct rtable *ort = (struct rtable *) dst_orig;
2267 struct rtable *rt;
2268
2269 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2270 if (rt) {
2271 struct dst_entry *new = &rt->dst;
2272
2273 new->__use = 1;
2274 new->input = dst_discard;
2275 new->output = dst_discard_sk;
2276
2277 new->dev = ort->dst.dev;
2278 if (new->dev)
2279 dev_hold(new->dev);
2280
2281 rt->rt_is_input = ort->rt_is_input;
2282 rt->rt_iif = ort->rt_iif;
2283 rt->rt_pmtu = ort->rt_pmtu;
2284
2285 rt->rt_genid = rt_genid_ipv4(net);
2286 rt->rt_flags = ort->rt_flags;
2287 rt->rt_type = ort->rt_type;
2288 rt->rt_gateway = ort->rt_gateway;
2289 rt->rt_uses_gateway = ort->rt_uses_gateway;
2290
2291 INIT_LIST_HEAD(&rt->rt_uncached);
2292 dst_free(new);
2293 }
2294
2295 dst_release(dst_orig);
2296
2297 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2298 }
2299
2300 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2301 const struct sock *sk)
2302 {
2303 struct rtable *rt = __ip_route_output_key(net, flp4);
2304
2305 if (IS_ERR(rt))
2306 return rt;
2307
2308 if (flp4->flowi4_proto)
2309 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2310 flowi4_to_flowi(flp4),
2311 sk, 0);
2312
2313 return rt;
2314 }
2315 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2316
2317 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, u32 table_id,
2318 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2319 u32 seq, int event, int nowait, unsigned int flags)
2320 {
2321 struct rtable *rt = skb_rtable(skb);
2322 struct rtmsg *r;
2323 struct nlmsghdr *nlh;
2324 unsigned long expires = 0;
2325 u32 error;
2326 u32 metrics[RTAX_MAX];
2327
2328 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2329 if (!nlh)
2330 return -EMSGSIZE;
2331
2332 r = nlmsg_data(nlh);
2333 r->rtm_family = AF_INET;
2334 r->rtm_dst_len = 32;
2335 r->rtm_src_len = 0;
2336 r->rtm_tos = fl4->flowi4_tos;
2337 r->rtm_table = table_id;
2338 if (nla_put_u32(skb, RTA_TABLE, table_id))
2339 goto nla_put_failure;
2340 r->rtm_type = rt->rt_type;
2341 r->rtm_scope = RT_SCOPE_UNIVERSE;
2342 r->rtm_protocol = RTPROT_UNSPEC;
2343 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2344 if (rt->rt_flags & RTCF_NOTIFY)
2345 r->rtm_flags |= RTM_F_NOTIFY;
2346 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2347 r->rtm_flags |= RTCF_DOREDIRECT;
2348
2349 if (nla_put_in_addr(skb, RTA_DST, dst))
2350 goto nla_put_failure;
2351 if (src) {
2352 r->rtm_src_len = 32;
2353 if (nla_put_in_addr(skb, RTA_SRC, src))
2354 goto nla_put_failure;
2355 }
2356 if (rt->dst.dev &&
2357 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2358 goto nla_put_failure;
2359 #ifdef CONFIG_IP_ROUTE_CLASSID
2360 if (rt->dst.tclassid &&
2361 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2362 goto nla_put_failure;
2363 #endif
2364 if (!rt_is_input_route(rt) &&
2365 fl4->saddr != src) {
2366 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2367 goto nla_put_failure;
2368 }
2369 if (rt->rt_uses_gateway &&
2370 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2371 goto nla_put_failure;
2372
2373 expires = rt->dst.expires;
2374 if (expires) {
2375 unsigned long now = jiffies;
2376
2377 if (time_before(now, expires))
2378 expires -= now;
2379 else
2380 expires = 0;
2381 }
2382
2383 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2384 if (rt->rt_pmtu && expires)
2385 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2386 if (rtnetlink_put_metrics(skb, metrics) < 0)
2387 goto nla_put_failure;
2388
2389 if (fl4->flowi4_mark &&
2390 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2391 goto nla_put_failure;
2392
2393 error = rt->dst.error;
2394
2395 if (rt_is_input_route(rt)) {
2396 #ifdef CONFIG_IP_MROUTE
2397 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2398 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2399 int err = ipmr_get_route(net, skb,
2400 fl4->saddr, fl4->daddr,
2401 r, nowait);
2402 if (err <= 0) {
2403 if (!nowait) {
2404 if (err == 0)
2405 return 0;
2406 goto nla_put_failure;
2407 } else {
2408 if (err == -EMSGSIZE)
2409 goto nla_put_failure;
2410 error = err;
2411 }
2412 }
2413 } else
2414 #endif
2415 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2416 goto nla_put_failure;
2417 }
2418
2419 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2420 goto nla_put_failure;
2421
2422 nlmsg_end(skb, nlh);
2423 return 0;
2424
2425 nla_put_failure:
2426 nlmsg_cancel(skb, nlh);
2427 return -EMSGSIZE;
2428 }
2429
2430 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2431 {
2432 struct net *net = sock_net(in_skb->sk);
2433 struct rtmsg *rtm;
2434 struct nlattr *tb[RTA_MAX+1];
2435 struct rtable *rt = NULL;
2436 struct flowi4 fl4;
2437 __be32 dst = 0;
2438 __be32 src = 0;
2439 u32 iif;
2440 int err;
2441 int mark;
2442 struct sk_buff *skb;
2443 u32 table_id = RT_TABLE_MAIN;
2444
2445 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2446 if (err < 0)
2447 goto errout;
2448
2449 rtm = nlmsg_data(nlh);
2450
2451 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2452 if (!skb) {
2453 err = -ENOBUFS;
2454 goto errout;
2455 }
2456
2457 /* Reserve room for dummy headers, this skb can pass
2458 through good chunk of routing engine.
2459 */
2460 skb_reset_mac_header(skb);
2461 skb_reset_network_header(skb);
2462
2463 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2464 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2465 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2466
2467 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2468 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2469 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2470 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2471
2472 memset(&fl4, 0, sizeof(fl4));
2473 fl4.daddr = dst;
2474 fl4.saddr = src;
2475 fl4.flowi4_tos = rtm->rtm_tos;
2476 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2477 fl4.flowi4_mark = mark;
2478
2479 if (iif) {
2480 struct net_device *dev;
2481
2482 dev = __dev_get_by_index(net, iif);
2483 if (!dev) {
2484 err = -ENODEV;
2485 goto errout_free;
2486 }
2487
2488 skb->protocol = htons(ETH_P_IP);
2489 skb->dev = dev;
2490 skb->mark = mark;
2491 local_bh_disable();
2492 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2493 local_bh_enable();
2494
2495 rt = skb_rtable(skb);
2496 if (err == 0 && rt->dst.error)
2497 err = -rt->dst.error;
2498 } else {
2499 rt = ip_route_output_key(net, &fl4);
2500
2501 err = 0;
2502 if (IS_ERR(rt))
2503 err = PTR_ERR(rt);
2504 }
2505
2506 if (err)
2507 goto errout_free;
2508
2509 skb_dst_set(skb, &rt->dst);
2510 if (rtm->rtm_flags & RTM_F_NOTIFY)
2511 rt->rt_flags |= RTCF_NOTIFY;
2512
2513 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
2514 table_id = rt->rt_table_id;
2515
2516 err = rt_fill_info(net, dst, src, table_id, &fl4, skb,
2517 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2518 RTM_NEWROUTE, 0, 0);
2519 if (err < 0)
2520 goto errout_free;
2521
2522 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2523 errout:
2524 return err;
2525
2526 errout_free:
2527 kfree_skb(skb);
2528 goto errout;
2529 }
2530
2531 void ip_rt_multicast_event(struct in_device *in_dev)
2532 {
2533 rt_cache_flush(dev_net(in_dev->dev));
2534 }
2535
2536 #ifdef CONFIG_SYSCTL
2537 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2538 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2539 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2540 static int ip_rt_gc_elasticity __read_mostly = 8;
2541
2542 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2543 void __user *buffer,
2544 size_t *lenp, loff_t *ppos)
2545 {
2546 struct net *net = (struct net *)__ctl->extra1;
2547
2548 if (write) {
2549 rt_cache_flush(net);
2550 fnhe_genid_bump(net);
2551 return 0;
2552 }
2553
2554 return -EINVAL;
2555 }
2556
2557 static struct ctl_table ipv4_route_table[] = {
2558 {
2559 .procname = "gc_thresh",
2560 .data = &ipv4_dst_ops.gc_thresh,
2561 .maxlen = sizeof(int),
2562 .mode = 0644,
2563 .proc_handler = proc_dointvec,
2564 },
2565 {
2566 .procname = "max_size",
2567 .data = &ip_rt_max_size,
2568 .maxlen = sizeof(int),
2569 .mode = 0644,
2570 .proc_handler = proc_dointvec,
2571 },
2572 {
2573 /* Deprecated. Use gc_min_interval_ms */
2574
2575 .procname = "gc_min_interval",
2576 .data = &ip_rt_gc_min_interval,
2577 .maxlen = sizeof(int),
2578 .mode = 0644,
2579 .proc_handler = proc_dointvec_jiffies,
2580 },
2581 {
2582 .procname = "gc_min_interval_ms",
2583 .data = &ip_rt_gc_min_interval,
2584 .maxlen = sizeof(int),
2585 .mode = 0644,
2586 .proc_handler = proc_dointvec_ms_jiffies,
2587 },
2588 {
2589 .procname = "gc_timeout",
2590 .data = &ip_rt_gc_timeout,
2591 .maxlen = sizeof(int),
2592 .mode = 0644,
2593 .proc_handler = proc_dointvec_jiffies,
2594 },
2595 {
2596 .procname = "gc_interval",
2597 .data = &ip_rt_gc_interval,
2598 .maxlen = sizeof(int),
2599 .mode = 0644,
2600 .proc_handler = proc_dointvec_jiffies,
2601 },
2602 {
2603 .procname = "redirect_load",
2604 .data = &ip_rt_redirect_load,
2605 .maxlen = sizeof(int),
2606 .mode = 0644,
2607 .proc_handler = proc_dointvec,
2608 },
2609 {
2610 .procname = "redirect_number",
2611 .data = &ip_rt_redirect_number,
2612 .maxlen = sizeof(int),
2613 .mode = 0644,
2614 .proc_handler = proc_dointvec,
2615 },
2616 {
2617 .procname = "redirect_silence",
2618 .data = &ip_rt_redirect_silence,
2619 .maxlen = sizeof(int),
2620 .mode = 0644,
2621 .proc_handler = proc_dointvec,
2622 },
2623 {
2624 .procname = "error_cost",
2625 .data = &ip_rt_error_cost,
2626 .maxlen = sizeof(int),
2627 .mode = 0644,
2628 .proc_handler = proc_dointvec,
2629 },
2630 {
2631 .procname = "error_burst",
2632 .data = &ip_rt_error_burst,
2633 .maxlen = sizeof(int),
2634 .mode = 0644,
2635 .proc_handler = proc_dointvec,
2636 },
2637 {
2638 .procname = "gc_elasticity",
2639 .data = &ip_rt_gc_elasticity,
2640 .maxlen = sizeof(int),
2641 .mode = 0644,
2642 .proc_handler = proc_dointvec,
2643 },
2644 {
2645 .procname = "mtu_expires",
2646 .data = &ip_rt_mtu_expires,
2647 .maxlen = sizeof(int),
2648 .mode = 0644,
2649 .proc_handler = proc_dointvec_jiffies,
2650 },
2651 {
2652 .procname = "min_pmtu",
2653 .data = &ip_rt_min_pmtu,
2654 .maxlen = sizeof(int),
2655 .mode = 0644,
2656 .proc_handler = proc_dointvec,
2657 },
2658 {
2659 .procname = "min_adv_mss",
2660 .data = &ip_rt_min_advmss,
2661 .maxlen = sizeof(int),
2662 .mode = 0644,
2663 .proc_handler = proc_dointvec,
2664 },
2665 { }
2666 };
2667
2668 static struct ctl_table ipv4_route_flush_table[] = {
2669 {
2670 .procname = "flush",
2671 .maxlen = sizeof(int),
2672 .mode = 0200,
2673 .proc_handler = ipv4_sysctl_rtcache_flush,
2674 },
2675 { },
2676 };
2677
2678 static __net_init int sysctl_route_net_init(struct net *net)
2679 {
2680 struct ctl_table *tbl;
2681
2682 tbl = ipv4_route_flush_table;
2683 if (!net_eq(net, &init_net)) {
2684 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2685 if (!tbl)
2686 goto err_dup;
2687
2688 /* Don't export sysctls to unprivileged users */
2689 if (net->user_ns != &init_user_ns)
2690 tbl[0].procname = NULL;
2691 }
2692 tbl[0].extra1 = net;
2693
2694 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2695 if (!net->ipv4.route_hdr)
2696 goto err_reg;
2697 return 0;
2698
2699 err_reg:
2700 if (tbl != ipv4_route_flush_table)
2701 kfree(tbl);
2702 err_dup:
2703 return -ENOMEM;
2704 }
2705
2706 static __net_exit void sysctl_route_net_exit(struct net *net)
2707 {
2708 struct ctl_table *tbl;
2709
2710 tbl = net->ipv4.route_hdr->ctl_table_arg;
2711 unregister_net_sysctl_table(net->ipv4.route_hdr);
2712 BUG_ON(tbl == ipv4_route_flush_table);
2713 kfree(tbl);
2714 }
2715
2716 static __net_initdata struct pernet_operations sysctl_route_ops = {
2717 .init = sysctl_route_net_init,
2718 .exit = sysctl_route_net_exit,
2719 };
2720 #endif
2721
2722 static __net_init int rt_genid_init(struct net *net)
2723 {
2724 atomic_set(&net->ipv4.rt_genid, 0);
2725 atomic_set(&net->fnhe_genid, 0);
2726 get_random_bytes(&net->ipv4.dev_addr_genid,
2727 sizeof(net->ipv4.dev_addr_genid));
2728 return 0;
2729 }
2730
2731 static __net_initdata struct pernet_operations rt_genid_ops = {
2732 .init = rt_genid_init,
2733 };
2734
2735 static int __net_init ipv4_inetpeer_init(struct net *net)
2736 {
2737 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2738
2739 if (!bp)
2740 return -ENOMEM;
2741 inet_peer_base_init(bp);
2742 net->ipv4.peers = bp;
2743 return 0;
2744 }
2745
2746 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2747 {
2748 struct inet_peer_base *bp = net->ipv4.peers;
2749
2750 net->ipv4.peers = NULL;
2751 inetpeer_invalidate_tree(bp);
2752 kfree(bp);
2753 }
2754
2755 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2756 .init = ipv4_inetpeer_init,
2757 .exit = ipv4_inetpeer_exit,
2758 };
2759
2760 #ifdef CONFIG_IP_ROUTE_CLASSID
2761 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2762 #endif /* CONFIG_IP_ROUTE_CLASSID */
2763
2764 int __init ip_rt_init(void)
2765 {
2766 int rc = 0;
2767 int cpu;
2768
2769 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2770 if (!ip_idents)
2771 panic("IP: failed to allocate ip_idents\n");
2772
2773 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2774
2775 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
2776 if (!ip_tstamps)
2777 panic("IP: failed to allocate ip_tstamps\n");
2778
2779 for_each_possible_cpu(cpu) {
2780 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
2781
2782 INIT_LIST_HEAD(&ul->head);
2783 spin_lock_init(&ul->lock);
2784 }
2785 #ifdef CONFIG_IP_ROUTE_CLASSID
2786 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2787 if (!ip_rt_acct)
2788 panic("IP: failed to allocate ip_rt_acct\n");
2789 #endif
2790
2791 ipv4_dst_ops.kmem_cachep =
2792 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2793 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2794
2795 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2796
2797 if (dst_entries_init(&ipv4_dst_ops) < 0)
2798 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2799
2800 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2801 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2802
2803 ipv4_dst_ops.gc_thresh = ~0;
2804 ip_rt_max_size = INT_MAX;
2805
2806 devinet_init();
2807 ip_fib_init();
2808
2809 if (ip_rt_proc_init())
2810 pr_err("Unable to create route proc files\n");
2811 #ifdef CONFIG_XFRM
2812 xfrm_init();
2813 xfrm4_init();
2814 #endif
2815 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2816
2817 #ifdef CONFIG_SYSCTL
2818 register_pernet_subsys(&sysctl_route_ops);
2819 #endif
2820 register_pernet_subsys(&rt_genid_ops);
2821 register_pernet_subsys(&ipv4_inetpeer_ops);
2822 return rc;
2823 }
2824
2825 #ifdef CONFIG_SYSCTL
2826 /*
2827 * We really need to sanitize the damn ipv4 init order, then all
2828 * this nonsense will go away.
2829 */
2830 void __init ip_static_sysctl_init(void)
2831 {
2832 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2833 }
2834 #endif
Linux kernel - Deliverables
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