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ipv4: introduce ip_dst_mtu_maybe_forward and protect forwarding path against pmtu...
[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 <net/dst.h>
93 #include <net/net_namespace.h>
94 #include <net/protocol.h>
95 #include <net/ip.h>
96 #include <net/route.h>
97 #include <net/inetpeer.h>
98 #include <net/sock.h>
99 #include <net/ip_fib.h>
100 #include <net/arp.h>
101 #include <net/tcp.h>
102 #include <net/icmp.h>
103 #include <net/xfrm.h>
104 #include <net/netevent.h>
105 #include <net/rtnetlink.h>
106 #ifdef CONFIG_SYSCTL
107 #include <linux/sysctl.h>
108 #include <linux/kmemleak.h>
109 #endif
110 #include <net/secure_seq.h>
111
112 #define RT_FL_TOS(oldflp4) \
113 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
114
115 #define RT_GC_TIMEOUT (300*HZ)
116
117 static int ip_rt_max_size;
118 static int ip_rt_redirect_number __read_mostly = 9;
119 static int ip_rt_redirect_load __read_mostly = HZ / 50;
120 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
121 static int ip_rt_error_cost __read_mostly = HZ;
122 static int ip_rt_error_burst __read_mostly = 5 * HZ;
123 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
124 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
125 static int ip_rt_min_advmss __read_mostly = 256;
126
127 /*
128 * Interface to generic destination cache.
129 */
130
131 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
132 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
133 static unsigned int ipv4_mtu(const struct dst_entry *dst);
134 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
135 static void ipv4_link_failure(struct sk_buff *skb);
136 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
137 struct sk_buff *skb, u32 mtu);
138 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
139 struct sk_buff *skb);
140 static void ipv4_dst_destroy(struct dst_entry *dst);
141
142 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
143 int how)
144 {
145 }
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 .protocol = cpu_to_be16(ETH_P_IP),
160 .check = ipv4_dst_check,
161 .default_advmss = ipv4_default_advmss,
162 .mtu = ipv4_mtu,
163 .cow_metrics = ipv4_cow_metrics,
164 .destroy = ipv4_dst_destroy,
165 .ifdown = ipv4_dst_ifdown,
166 .negative_advice = ipv4_negative_advice,
167 .link_failure = ipv4_link_failure,
168 .update_pmtu = ip_rt_update_pmtu,
169 .redirect = ip_do_redirect,
170 .local_out = __ip_local_out,
171 .neigh_lookup = ipv4_neigh_lookup,
172 };
173
174 #define ECN_OR_COST(class) TC_PRIO_##class
175
176 const __u8 ip_tos2prio[16] = {
177 TC_PRIO_BESTEFFORT,
178 ECN_OR_COST(BESTEFFORT),
179 TC_PRIO_BESTEFFORT,
180 ECN_OR_COST(BESTEFFORT),
181 TC_PRIO_BULK,
182 ECN_OR_COST(BULK),
183 TC_PRIO_BULK,
184 ECN_OR_COST(BULK),
185 TC_PRIO_INTERACTIVE,
186 ECN_OR_COST(INTERACTIVE),
187 TC_PRIO_INTERACTIVE,
188 ECN_OR_COST(INTERACTIVE),
189 TC_PRIO_INTERACTIVE_BULK,
190 ECN_OR_COST(INTERACTIVE_BULK),
191 TC_PRIO_INTERACTIVE_BULK,
192 ECN_OR_COST(INTERACTIVE_BULK)
193 };
194 EXPORT_SYMBOL(ip_tos2prio);
195
196 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
197 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
198
199 #ifdef CONFIG_PROC_FS
200 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
201 {
202 if (*pos)
203 return NULL;
204 return SEQ_START_TOKEN;
205 }
206
207 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
208 {
209 ++*pos;
210 return NULL;
211 }
212
213 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
214 {
215 }
216
217 static int rt_cache_seq_show(struct seq_file *seq, void *v)
218 {
219 if (v == SEQ_START_TOKEN)
220 seq_printf(seq, "%-127s\n",
221 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
222 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
223 "HHUptod\tSpecDst");
224 return 0;
225 }
226
227 static const struct seq_operations rt_cache_seq_ops = {
228 .start = rt_cache_seq_start,
229 .next = rt_cache_seq_next,
230 .stop = rt_cache_seq_stop,
231 .show = rt_cache_seq_show,
232 };
233
234 static int rt_cache_seq_open(struct inode *inode, struct file *file)
235 {
236 return seq_open(file, &rt_cache_seq_ops);
237 }
238
239 static const struct file_operations rt_cache_seq_fops = {
240 .owner = THIS_MODULE,
241 .open = rt_cache_seq_open,
242 .read = seq_read,
243 .llseek = seq_lseek,
244 .release = seq_release,
245 };
246
247
248 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
249 {
250 int cpu;
251
252 if (*pos == 0)
253 return SEQ_START_TOKEN;
254
255 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
256 if (!cpu_possible(cpu))
257 continue;
258 *pos = cpu+1;
259 return &per_cpu(rt_cache_stat, cpu);
260 }
261 return NULL;
262 }
263
264 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
265 {
266 int cpu;
267
268 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
269 if (!cpu_possible(cpu))
270 continue;
271 *pos = cpu+1;
272 return &per_cpu(rt_cache_stat, cpu);
273 }
274 return NULL;
275
276 }
277
278 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
279 {
280
281 }
282
283 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
284 {
285 struct rt_cache_stat *st = v;
286
287 if (v == SEQ_START_TOKEN) {
288 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");
289 return 0;
290 }
291
292 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
293 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
294 dst_entries_get_slow(&ipv4_dst_ops),
295 0, /* st->in_hit */
296 st->in_slow_tot,
297 st->in_slow_mc,
298 st->in_no_route,
299 st->in_brd,
300 st->in_martian_dst,
301 st->in_martian_src,
302
303 0, /* st->out_hit */
304 st->out_slow_tot,
305 st->out_slow_mc,
306
307 0, /* st->gc_total */
308 0, /* st->gc_ignored */
309 0, /* st->gc_goal_miss */
310 0, /* st->gc_dst_overflow */
311 0, /* st->in_hlist_search */
312 0 /* st->out_hlist_search */
313 );
314 return 0;
315 }
316
317 static const struct seq_operations rt_cpu_seq_ops = {
318 .start = rt_cpu_seq_start,
319 .next = rt_cpu_seq_next,
320 .stop = rt_cpu_seq_stop,
321 .show = rt_cpu_seq_show,
322 };
323
324
325 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
326 {
327 return seq_open(file, &rt_cpu_seq_ops);
328 }
329
330 static const struct file_operations rt_cpu_seq_fops = {
331 .owner = THIS_MODULE,
332 .open = rt_cpu_seq_open,
333 .read = seq_read,
334 .llseek = seq_lseek,
335 .release = seq_release,
336 };
337
338 #ifdef CONFIG_IP_ROUTE_CLASSID
339 static int rt_acct_proc_show(struct seq_file *m, void *v)
340 {
341 struct ip_rt_acct *dst, *src;
342 unsigned int i, j;
343
344 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
345 if (!dst)
346 return -ENOMEM;
347
348 for_each_possible_cpu(i) {
349 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
350 for (j = 0; j < 256; j++) {
351 dst[j].o_bytes += src[j].o_bytes;
352 dst[j].o_packets += src[j].o_packets;
353 dst[j].i_bytes += src[j].i_bytes;
354 dst[j].i_packets += src[j].i_packets;
355 }
356 }
357
358 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
359 kfree(dst);
360 return 0;
361 }
362
363 static int rt_acct_proc_open(struct inode *inode, struct file *file)
364 {
365 return single_open(file, rt_acct_proc_show, NULL);
366 }
367
368 static const struct file_operations rt_acct_proc_fops = {
369 .owner = THIS_MODULE,
370 .open = rt_acct_proc_open,
371 .read = seq_read,
372 .llseek = seq_lseek,
373 .release = single_release,
374 };
375 #endif
376
377 static int __net_init ip_rt_do_proc_init(struct net *net)
378 {
379 struct proc_dir_entry *pde;
380
381 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
382 &rt_cache_seq_fops);
383 if (!pde)
384 goto err1;
385
386 pde = proc_create("rt_cache", S_IRUGO,
387 net->proc_net_stat, &rt_cpu_seq_fops);
388 if (!pde)
389 goto err2;
390
391 #ifdef CONFIG_IP_ROUTE_CLASSID
392 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
393 if (!pde)
394 goto err3;
395 #endif
396 return 0;
397
398 #ifdef CONFIG_IP_ROUTE_CLASSID
399 err3:
400 remove_proc_entry("rt_cache", net->proc_net_stat);
401 #endif
402 err2:
403 remove_proc_entry("rt_cache", net->proc_net);
404 err1:
405 return -ENOMEM;
406 }
407
408 static void __net_exit ip_rt_do_proc_exit(struct net *net)
409 {
410 remove_proc_entry("rt_cache", net->proc_net_stat);
411 remove_proc_entry("rt_cache", net->proc_net);
412 #ifdef CONFIG_IP_ROUTE_CLASSID
413 remove_proc_entry("rt_acct", net->proc_net);
414 #endif
415 }
416
417 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
418 .init = ip_rt_do_proc_init,
419 .exit = ip_rt_do_proc_exit,
420 };
421
422 static int __init ip_rt_proc_init(void)
423 {
424 return register_pernet_subsys(&ip_rt_proc_ops);
425 }
426
427 #else
428 static inline int ip_rt_proc_init(void)
429 {
430 return 0;
431 }
432 #endif /* CONFIG_PROC_FS */
433
434 static inline bool rt_is_expired(const struct rtable *rth)
435 {
436 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
437 }
438
439 void rt_cache_flush(struct net *net)
440 {
441 rt_genid_bump_ipv4(net);
442 }
443
444 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
445 struct sk_buff *skb,
446 const void *daddr)
447 {
448 struct net_device *dev = dst->dev;
449 const __be32 *pkey = daddr;
450 const struct rtable *rt;
451 struct neighbour *n;
452
453 rt = (const struct rtable *) dst;
454 if (rt->rt_gateway)
455 pkey = (const __be32 *) &rt->rt_gateway;
456 else if (skb)
457 pkey = &ip_hdr(skb)->daddr;
458
459 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
460 if (n)
461 return n;
462 return neigh_create(&arp_tbl, pkey, dev);
463 }
464
465 /*
466 * Peer allocation may fail only in serious out-of-memory conditions. However
467 * we still can generate some output.
468 * Random ID selection looks a bit dangerous because we have no chances to
469 * select ID being unique in a reasonable period of time.
470 * But broken packet identifier may be better than no packet at all.
471 */
472 static void ip_select_fb_ident(struct iphdr *iph)
473 {
474 static DEFINE_SPINLOCK(ip_fb_id_lock);
475 static u32 ip_fallback_id;
476 u32 salt;
477
478 spin_lock_bh(&ip_fb_id_lock);
479 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
480 iph->id = htons(salt & 0xFFFF);
481 ip_fallback_id = salt;
482 spin_unlock_bh(&ip_fb_id_lock);
483 }
484
485 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
486 {
487 struct net *net = dev_net(dst->dev);
488 struct inet_peer *peer;
489
490 peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1);
491 if (peer) {
492 iph->id = htons(inet_getid(peer, more));
493 inet_putpeer(peer);
494 return;
495 }
496
497 ip_select_fb_ident(iph);
498 }
499 EXPORT_SYMBOL(__ip_select_ident);
500
501 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
502 const struct iphdr *iph,
503 int oif, u8 tos,
504 u8 prot, u32 mark, int flow_flags)
505 {
506 if (sk) {
507 const struct inet_sock *inet = inet_sk(sk);
508
509 oif = sk->sk_bound_dev_if;
510 mark = sk->sk_mark;
511 tos = RT_CONN_FLAGS(sk);
512 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
513 }
514 flowi4_init_output(fl4, oif, mark, tos,
515 RT_SCOPE_UNIVERSE, prot,
516 flow_flags,
517 iph->daddr, iph->saddr, 0, 0);
518 }
519
520 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
521 const struct sock *sk)
522 {
523 const struct iphdr *iph = ip_hdr(skb);
524 int oif = skb->dev->ifindex;
525 u8 tos = RT_TOS(iph->tos);
526 u8 prot = iph->protocol;
527 u32 mark = skb->mark;
528
529 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
530 }
531
532 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
533 {
534 const struct inet_sock *inet = inet_sk(sk);
535 const struct ip_options_rcu *inet_opt;
536 __be32 daddr = inet->inet_daddr;
537
538 rcu_read_lock();
539 inet_opt = rcu_dereference(inet->inet_opt);
540 if (inet_opt && inet_opt->opt.srr)
541 daddr = inet_opt->opt.faddr;
542 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
543 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
544 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
545 inet_sk_flowi_flags(sk),
546 daddr, inet->inet_saddr, 0, 0);
547 rcu_read_unlock();
548 }
549
550 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
551 const struct sk_buff *skb)
552 {
553 if (skb)
554 build_skb_flow_key(fl4, skb, sk);
555 else
556 build_sk_flow_key(fl4, sk);
557 }
558
559 static inline void rt_free(struct rtable *rt)
560 {
561 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
562 }
563
564 static DEFINE_SPINLOCK(fnhe_lock);
565
566 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
567 {
568 struct rtable *rt;
569
570 rt = rcu_dereference(fnhe->fnhe_rth_input);
571 if (rt) {
572 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
573 rt_free(rt);
574 }
575 rt = rcu_dereference(fnhe->fnhe_rth_output);
576 if (rt) {
577 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
578 rt_free(rt);
579 }
580 }
581
582 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
583 {
584 struct fib_nh_exception *fnhe, *oldest;
585
586 oldest = rcu_dereference(hash->chain);
587 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
588 fnhe = rcu_dereference(fnhe->fnhe_next)) {
589 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
590 oldest = fnhe;
591 }
592 fnhe_flush_routes(oldest);
593 return oldest;
594 }
595
596 static inline u32 fnhe_hashfun(__be32 daddr)
597 {
598 u32 hval;
599
600 hval = (__force u32) daddr;
601 hval ^= (hval >> 11) ^ (hval >> 22);
602
603 return hval & (FNHE_HASH_SIZE - 1);
604 }
605
606 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
607 {
608 rt->rt_pmtu = fnhe->fnhe_pmtu;
609 rt->dst.expires = fnhe->fnhe_expires;
610
611 if (fnhe->fnhe_gw) {
612 rt->rt_flags |= RTCF_REDIRECTED;
613 rt->rt_gateway = fnhe->fnhe_gw;
614 rt->rt_uses_gateway = 1;
615 }
616 }
617
618 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
619 u32 pmtu, unsigned long expires)
620 {
621 struct fnhe_hash_bucket *hash;
622 struct fib_nh_exception *fnhe;
623 struct rtable *rt;
624 unsigned int i;
625 int depth;
626 u32 hval = fnhe_hashfun(daddr);
627
628 spin_lock_bh(&fnhe_lock);
629
630 hash = nh->nh_exceptions;
631 if (!hash) {
632 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
633 if (!hash)
634 goto out_unlock;
635 nh->nh_exceptions = hash;
636 }
637
638 hash += hval;
639
640 depth = 0;
641 for (fnhe = rcu_dereference(hash->chain); fnhe;
642 fnhe = rcu_dereference(fnhe->fnhe_next)) {
643 if (fnhe->fnhe_daddr == daddr)
644 break;
645 depth++;
646 }
647
648 if (fnhe) {
649 if (gw)
650 fnhe->fnhe_gw = gw;
651 if (pmtu) {
652 fnhe->fnhe_pmtu = pmtu;
653 fnhe->fnhe_expires = max(1UL, expires);
654 }
655 /* Update all cached dsts too */
656 rt = rcu_dereference(fnhe->fnhe_rth_input);
657 if (rt)
658 fill_route_from_fnhe(rt, fnhe);
659 rt = rcu_dereference(fnhe->fnhe_rth_output);
660 if (rt)
661 fill_route_from_fnhe(rt, fnhe);
662 } else {
663 if (depth > FNHE_RECLAIM_DEPTH)
664 fnhe = fnhe_oldest(hash);
665 else {
666 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
667 if (!fnhe)
668 goto out_unlock;
669
670 fnhe->fnhe_next = hash->chain;
671 rcu_assign_pointer(hash->chain, fnhe);
672 }
673 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
674 fnhe->fnhe_daddr = daddr;
675 fnhe->fnhe_gw = gw;
676 fnhe->fnhe_pmtu = pmtu;
677 fnhe->fnhe_expires = expires;
678
679 /* Exception created; mark the cached routes for the nexthop
680 * stale, so anyone caching it rechecks if this exception
681 * applies to them.
682 */
683 rt = rcu_dereference(nh->nh_rth_input);
684 if (rt)
685 rt->dst.obsolete = DST_OBSOLETE_KILL;
686
687 for_each_possible_cpu(i) {
688 struct rtable __rcu **prt;
689 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
690 rt = rcu_dereference(*prt);
691 if (rt)
692 rt->dst.obsolete = DST_OBSOLETE_KILL;
693 }
694 }
695
696 fnhe->fnhe_stamp = jiffies;
697
698 out_unlock:
699 spin_unlock_bh(&fnhe_lock);
700 return;
701 }
702
703 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
704 bool kill_route)
705 {
706 __be32 new_gw = icmp_hdr(skb)->un.gateway;
707 __be32 old_gw = ip_hdr(skb)->saddr;
708 struct net_device *dev = skb->dev;
709 struct in_device *in_dev;
710 struct fib_result res;
711 struct neighbour *n;
712 struct net *net;
713
714 switch (icmp_hdr(skb)->code & 7) {
715 case ICMP_REDIR_NET:
716 case ICMP_REDIR_NETTOS:
717 case ICMP_REDIR_HOST:
718 case ICMP_REDIR_HOSTTOS:
719 break;
720
721 default:
722 return;
723 }
724
725 if (rt->rt_gateway != old_gw)
726 return;
727
728 in_dev = __in_dev_get_rcu(dev);
729 if (!in_dev)
730 return;
731
732 net = dev_net(dev);
733 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
734 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
735 ipv4_is_zeronet(new_gw))
736 goto reject_redirect;
737
738 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
739 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
740 goto reject_redirect;
741 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
742 goto reject_redirect;
743 } else {
744 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
745 goto reject_redirect;
746 }
747
748 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
749 if (n) {
750 if (!(n->nud_state & NUD_VALID)) {
751 neigh_event_send(n, NULL);
752 } else {
753 if (fib_lookup(net, fl4, &res) == 0) {
754 struct fib_nh *nh = &FIB_RES_NH(res);
755
756 update_or_create_fnhe(nh, fl4->daddr, new_gw,
757 0, 0);
758 }
759 if (kill_route)
760 rt->dst.obsolete = DST_OBSOLETE_KILL;
761 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
762 }
763 neigh_release(n);
764 }
765 return;
766
767 reject_redirect:
768 #ifdef CONFIG_IP_ROUTE_VERBOSE
769 if (IN_DEV_LOG_MARTIANS(in_dev)) {
770 const struct iphdr *iph = (const struct iphdr *) skb->data;
771 __be32 daddr = iph->daddr;
772 __be32 saddr = iph->saddr;
773
774 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
775 " Advised path = %pI4 -> %pI4\n",
776 &old_gw, dev->name, &new_gw,
777 &saddr, &daddr);
778 }
779 #endif
780 ;
781 }
782
783 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
784 {
785 struct rtable *rt;
786 struct flowi4 fl4;
787 const struct iphdr *iph = (const struct iphdr *) skb->data;
788 int oif = skb->dev->ifindex;
789 u8 tos = RT_TOS(iph->tos);
790 u8 prot = iph->protocol;
791 u32 mark = skb->mark;
792
793 rt = (struct rtable *) dst;
794
795 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
796 __ip_do_redirect(rt, skb, &fl4, true);
797 }
798
799 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
800 {
801 struct rtable *rt = (struct rtable *)dst;
802 struct dst_entry *ret = dst;
803
804 if (rt) {
805 if (dst->obsolete > 0) {
806 ip_rt_put(rt);
807 ret = NULL;
808 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
809 rt->dst.expires) {
810 ip_rt_put(rt);
811 ret = NULL;
812 }
813 }
814 return ret;
815 }
816
817 /*
818 * Algorithm:
819 * 1. The first ip_rt_redirect_number redirects are sent
820 * with exponential backoff, then we stop sending them at all,
821 * assuming that the host ignores our redirects.
822 * 2. If we did not see packets requiring redirects
823 * during ip_rt_redirect_silence, we assume that the host
824 * forgot redirected route and start to send redirects again.
825 *
826 * This algorithm is much cheaper and more intelligent than dumb load limiting
827 * in icmp.c.
828 *
829 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
830 * and "frag. need" (breaks PMTU discovery) in icmp.c.
831 */
832
833 void ip_rt_send_redirect(struct sk_buff *skb)
834 {
835 struct rtable *rt = skb_rtable(skb);
836 struct in_device *in_dev;
837 struct inet_peer *peer;
838 struct net *net;
839 int log_martians;
840
841 rcu_read_lock();
842 in_dev = __in_dev_get_rcu(rt->dst.dev);
843 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
844 rcu_read_unlock();
845 return;
846 }
847 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
848 rcu_read_unlock();
849
850 net = dev_net(rt->dst.dev);
851 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
852 if (!peer) {
853 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
854 rt_nexthop(rt, ip_hdr(skb)->daddr));
855 return;
856 }
857
858 /* No redirected packets during ip_rt_redirect_silence;
859 * reset the algorithm.
860 */
861 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
862 peer->rate_tokens = 0;
863
864 /* Too many ignored redirects; do not send anything
865 * set dst.rate_last to the last seen redirected packet.
866 */
867 if (peer->rate_tokens >= ip_rt_redirect_number) {
868 peer->rate_last = jiffies;
869 goto out_put_peer;
870 }
871
872 /* Check for load limit; set rate_last to the latest sent
873 * redirect.
874 */
875 if (peer->rate_tokens == 0 ||
876 time_after(jiffies,
877 (peer->rate_last +
878 (ip_rt_redirect_load << peer->rate_tokens)))) {
879 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
880
881 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
882 peer->rate_last = jiffies;
883 ++peer->rate_tokens;
884 #ifdef CONFIG_IP_ROUTE_VERBOSE
885 if (log_martians &&
886 peer->rate_tokens == ip_rt_redirect_number)
887 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
888 &ip_hdr(skb)->saddr, inet_iif(skb),
889 &ip_hdr(skb)->daddr, &gw);
890 #endif
891 }
892 out_put_peer:
893 inet_putpeer(peer);
894 }
895
896 static int ip_error(struct sk_buff *skb)
897 {
898 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
899 struct rtable *rt = skb_rtable(skb);
900 struct inet_peer *peer;
901 unsigned long now;
902 struct net *net;
903 bool send;
904 int code;
905
906 net = dev_net(rt->dst.dev);
907 if (!IN_DEV_FORWARD(in_dev)) {
908 switch (rt->dst.error) {
909 case EHOSTUNREACH:
910 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
911 break;
912
913 case ENETUNREACH:
914 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
915 break;
916 }
917 goto out;
918 }
919
920 switch (rt->dst.error) {
921 case EINVAL:
922 default:
923 goto out;
924 case EHOSTUNREACH:
925 code = ICMP_HOST_UNREACH;
926 break;
927 case ENETUNREACH:
928 code = ICMP_NET_UNREACH;
929 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
930 break;
931 case EACCES:
932 code = ICMP_PKT_FILTERED;
933 break;
934 }
935
936 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
937
938 send = true;
939 if (peer) {
940 now = jiffies;
941 peer->rate_tokens += now - peer->rate_last;
942 if (peer->rate_tokens > ip_rt_error_burst)
943 peer->rate_tokens = ip_rt_error_burst;
944 peer->rate_last = now;
945 if (peer->rate_tokens >= ip_rt_error_cost)
946 peer->rate_tokens -= ip_rt_error_cost;
947 else
948 send = false;
949 inet_putpeer(peer);
950 }
951 if (send)
952 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
953
954 out: kfree_skb(skb);
955 return 0;
956 }
957
958 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
959 {
960 struct dst_entry *dst = &rt->dst;
961 struct fib_result res;
962
963 if (dst_metric_locked(dst, RTAX_MTU))
964 return;
965
966 if (dst->dev->mtu < mtu)
967 return;
968
969 if (mtu < ip_rt_min_pmtu)
970 mtu = ip_rt_min_pmtu;
971
972 if (rt->rt_pmtu == mtu &&
973 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
974 return;
975
976 rcu_read_lock();
977 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
978 struct fib_nh *nh = &FIB_RES_NH(res);
979
980 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
981 jiffies + ip_rt_mtu_expires);
982 }
983 rcu_read_unlock();
984 }
985
986 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
987 struct sk_buff *skb, u32 mtu)
988 {
989 struct rtable *rt = (struct rtable *) dst;
990 struct flowi4 fl4;
991
992 ip_rt_build_flow_key(&fl4, sk, skb);
993 __ip_rt_update_pmtu(rt, &fl4, mtu);
994 }
995
996 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
997 int oif, u32 mark, u8 protocol, int flow_flags)
998 {
999 const struct iphdr *iph = (const struct iphdr *) skb->data;
1000 struct flowi4 fl4;
1001 struct rtable *rt;
1002
1003 __build_flow_key(&fl4, NULL, iph, oif,
1004 RT_TOS(iph->tos), protocol, mark, flow_flags);
1005 rt = __ip_route_output_key(net, &fl4);
1006 if (!IS_ERR(rt)) {
1007 __ip_rt_update_pmtu(rt, &fl4, mtu);
1008 ip_rt_put(rt);
1009 }
1010 }
1011 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1012
1013 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1014 {
1015 const struct iphdr *iph = (const struct iphdr *) skb->data;
1016 struct flowi4 fl4;
1017 struct rtable *rt;
1018
1019 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1020 rt = __ip_route_output_key(sock_net(sk), &fl4);
1021 if (!IS_ERR(rt)) {
1022 __ip_rt_update_pmtu(rt, &fl4, mtu);
1023 ip_rt_put(rt);
1024 }
1025 }
1026
1027 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1028 {
1029 const struct iphdr *iph = (const struct iphdr *) skb->data;
1030 struct flowi4 fl4;
1031 struct rtable *rt;
1032 struct dst_entry *dst;
1033 bool new = false;
1034
1035 bh_lock_sock(sk);
1036
1037 if (!ip_sk_accept_pmtu(sk))
1038 goto out;
1039
1040 rt = (struct rtable *) __sk_dst_get(sk);
1041
1042 if (sock_owned_by_user(sk) || !rt) {
1043 __ipv4_sk_update_pmtu(skb, sk, mtu);
1044 goto out;
1045 }
1046
1047 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1048
1049 if (!__sk_dst_check(sk, 0)) {
1050 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1051 if (IS_ERR(rt))
1052 goto out;
1053
1054 new = true;
1055 }
1056
1057 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1058
1059 dst = dst_check(&rt->dst, 0);
1060 if (!dst) {
1061 if (new)
1062 dst_release(&rt->dst);
1063
1064 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1065 if (IS_ERR(rt))
1066 goto out;
1067
1068 new = true;
1069 }
1070
1071 if (new)
1072 __sk_dst_set(sk, &rt->dst);
1073
1074 out:
1075 bh_unlock_sock(sk);
1076 }
1077 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1078
1079 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1080 int oif, u32 mark, u8 protocol, int flow_flags)
1081 {
1082 const struct iphdr *iph = (const struct iphdr *) skb->data;
1083 struct flowi4 fl4;
1084 struct rtable *rt;
1085
1086 __build_flow_key(&fl4, NULL, iph, oif,
1087 RT_TOS(iph->tos), protocol, mark, flow_flags);
1088 rt = __ip_route_output_key(net, &fl4);
1089 if (!IS_ERR(rt)) {
1090 __ip_do_redirect(rt, skb, &fl4, false);
1091 ip_rt_put(rt);
1092 }
1093 }
1094 EXPORT_SYMBOL_GPL(ipv4_redirect);
1095
1096 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
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, sk, iph, 0, 0, 0, 0, 0);
1103 rt = __ip_route_output_key(sock_net(sk), &fl4);
1104 if (!IS_ERR(rt)) {
1105 __ip_do_redirect(rt, skb, &fl4, false);
1106 ip_rt_put(rt);
1107 }
1108 }
1109 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1110
1111 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1112 {
1113 struct rtable *rt = (struct rtable *) dst;
1114
1115 /* All IPV4 dsts are created with ->obsolete set to the value
1116 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1117 * into this function always.
1118 *
1119 * When a PMTU/redirect information update invalidates a route,
1120 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1121 * DST_OBSOLETE_DEAD by dst_free().
1122 */
1123 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1124 return NULL;
1125 return dst;
1126 }
1127
1128 static void ipv4_link_failure(struct sk_buff *skb)
1129 {
1130 struct rtable *rt;
1131
1132 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1133
1134 rt = skb_rtable(skb);
1135 if (rt)
1136 dst_set_expires(&rt->dst, 0);
1137 }
1138
1139 static int ip_rt_bug(struct sk_buff *skb)
1140 {
1141 pr_debug("%s: %pI4 -> %pI4, %s\n",
1142 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1143 skb->dev ? skb->dev->name : "?");
1144 kfree_skb(skb);
1145 WARN_ON(1);
1146 return 0;
1147 }
1148
1149 /*
1150 We do not cache source address of outgoing interface,
1151 because it is used only by IP RR, TS and SRR options,
1152 so that it out of fast path.
1153
1154 BTW remember: "addr" is allowed to be not aligned
1155 in IP options!
1156 */
1157
1158 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1159 {
1160 __be32 src;
1161
1162 if (rt_is_output_route(rt))
1163 src = ip_hdr(skb)->saddr;
1164 else {
1165 struct fib_result res;
1166 struct flowi4 fl4;
1167 struct iphdr *iph;
1168
1169 iph = ip_hdr(skb);
1170
1171 memset(&fl4, 0, sizeof(fl4));
1172 fl4.daddr = iph->daddr;
1173 fl4.saddr = iph->saddr;
1174 fl4.flowi4_tos = RT_TOS(iph->tos);
1175 fl4.flowi4_oif = rt->dst.dev->ifindex;
1176 fl4.flowi4_iif = skb->dev->ifindex;
1177 fl4.flowi4_mark = skb->mark;
1178
1179 rcu_read_lock();
1180 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1181 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1182 else
1183 src = inet_select_addr(rt->dst.dev,
1184 rt_nexthop(rt, iph->daddr),
1185 RT_SCOPE_UNIVERSE);
1186 rcu_read_unlock();
1187 }
1188 memcpy(addr, &src, 4);
1189 }
1190
1191 #ifdef CONFIG_IP_ROUTE_CLASSID
1192 static void set_class_tag(struct rtable *rt, u32 tag)
1193 {
1194 if (!(rt->dst.tclassid & 0xFFFF))
1195 rt->dst.tclassid |= tag & 0xFFFF;
1196 if (!(rt->dst.tclassid & 0xFFFF0000))
1197 rt->dst.tclassid |= tag & 0xFFFF0000;
1198 }
1199 #endif
1200
1201 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1202 {
1203 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1204
1205 if (advmss == 0) {
1206 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1207 ip_rt_min_advmss);
1208 if (advmss > 65535 - 40)
1209 advmss = 65535 - 40;
1210 }
1211 return advmss;
1212 }
1213
1214 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1215 {
1216 const struct rtable *rt = (const struct rtable *) dst;
1217 unsigned int mtu = rt->rt_pmtu;
1218
1219 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1220 mtu = dst_metric_raw(dst, RTAX_MTU);
1221
1222 if (mtu)
1223 return mtu;
1224
1225 mtu = dst->dev->mtu;
1226
1227 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1228 if (rt->rt_uses_gateway && mtu > 576)
1229 mtu = 576;
1230 }
1231
1232 return min_t(unsigned int, mtu, IP_MAX_MTU);
1233 }
1234
1235 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1236 {
1237 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1238 struct fib_nh_exception *fnhe;
1239 u32 hval;
1240
1241 if (!hash)
1242 return NULL;
1243
1244 hval = fnhe_hashfun(daddr);
1245
1246 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1247 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1248 if (fnhe->fnhe_daddr == daddr)
1249 return fnhe;
1250 }
1251 return NULL;
1252 }
1253
1254 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1255 __be32 daddr)
1256 {
1257 bool ret = false;
1258
1259 spin_lock_bh(&fnhe_lock);
1260
1261 if (daddr == fnhe->fnhe_daddr) {
1262 struct rtable __rcu **porig;
1263 struct rtable *orig;
1264 int genid = fnhe_genid(dev_net(rt->dst.dev));
1265
1266 if (rt_is_input_route(rt))
1267 porig = &fnhe->fnhe_rth_input;
1268 else
1269 porig = &fnhe->fnhe_rth_output;
1270 orig = rcu_dereference(*porig);
1271
1272 if (fnhe->fnhe_genid != genid) {
1273 fnhe->fnhe_genid = genid;
1274 fnhe->fnhe_gw = 0;
1275 fnhe->fnhe_pmtu = 0;
1276 fnhe->fnhe_expires = 0;
1277 fnhe_flush_routes(fnhe);
1278 orig = NULL;
1279 }
1280 fill_route_from_fnhe(rt, fnhe);
1281 if (!rt->rt_gateway)
1282 rt->rt_gateway = daddr;
1283
1284 if (!(rt->dst.flags & DST_NOCACHE)) {
1285 rcu_assign_pointer(*porig, rt);
1286 if (orig)
1287 rt_free(orig);
1288 ret = true;
1289 }
1290
1291 fnhe->fnhe_stamp = jiffies;
1292 }
1293 spin_unlock_bh(&fnhe_lock);
1294
1295 return ret;
1296 }
1297
1298 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1299 {
1300 struct rtable *orig, *prev, **p;
1301 bool ret = true;
1302
1303 if (rt_is_input_route(rt)) {
1304 p = (struct rtable **)&nh->nh_rth_input;
1305 } else {
1306 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1307 }
1308 orig = *p;
1309
1310 prev = cmpxchg(p, orig, rt);
1311 if (prev == orig) {
1312 if (orig)
1313 rt_free(orig);
1314 } else
1315 ret = false;
1316
1317 return ret;
1318 }
1319
1320 static DEFINE_SPINLOCK(rt_uncached_lock);
1321 static LIST_HEAD(rt_uncached_list);
1322
1323 static void rt_add_uncached_list(struct rtable *rt)
1324 {
1325 spin_lock_bh(&rt_uncached_lock);
1326 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1327 spin_unlock_bh(&rt_uncached_lock);
1328 }
1329
1330 static void ipv4_dst_destroy(struct dst_entry *dst)
1331 {
1332 struct rtable *rt = (struct rtable *) dst;
1333
1334 if (!list_empty(&rt->rt_uncached)) {
1335 spin_lock_bh(&rt_uncached_lock);
1336 list_del(&rt->rt_uncached);
1337 spin_unlock_bh(&rt_uncached_lock);
1338 }
1339 }
1340
1341 void rt_flush_dev(struct net_device *dev)
1342 {
1343 if (!list_empty(&rt_uncached_list)) {
1344 struct net *net = dev_net(dev);
1345 struct rtable *rt;
1346
1347 spin_lock_bh(&rt_uncached_lock);
1348 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1349 if (rt->dst.dev != dev)
1350 continue;
1351 rt->dst.dev = net->loopback_dev;
1352 dev_hold(rt->dst.dev);
1353 dev_put(dev);
1354 }
1355 spin_unlock_bh(&rt_uncached_lock);
1356 }
1357 }
1358
1359 static bool rt_cache_valid(const struct rtable *rt)
1360 {
1361 return rt &&
1362 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1363 !rt_is_expired(rt);
1364 }
1365
1366 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1367 const struct fib_result *res,
1368 struct fib_nh_exception *fnhe,
1369 struct fib_info *fi, u16 type, u32 itag)
1370 {
1371 bool cached = false;
1372
1373 if (fi) {
1374 struct fib_nh *nh = &FIB_RES_NH(*res);
1375
1376 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1377 rt->rt_gateway = nh->nh_gw;
1378 rt->rt_uses_gateway = 1;
1379 }
1380 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1381 #ifdef CONFIG_IP_ROUTE_CLASSID
1382 rt->dst.tclassid = nh->nh_tclassid;
1383 #endif
1384 if (unlikely(fnhe))
1385 cached = rt_bind_exception(rt, fnhe, daddr);
1386 else if (!(rt->dst.flags & DST_NOCACHE))
1387 cached = rt_cache_route(nh, rt);
1388 if (unlikely(!cached)) {
1389 /* Routes we intend to cache in nexthop exception or
1390 * FIB nexthop have the DST_NOCACHE bit clear.
1391 * However, if we are unsuccessful at storing this
1392 * route into the cache we really need to set it.
1393 */
1394 rt->dst.flags |= DST_NOCACHE;
1395 if (!rt->rt_gateway)
1396 rt->rt_gateway = daddr;
1397 rt_add_uncached_list(rt);
1398 }
1399 } else
1400 rt_add_uncached_list(rt);
1401
1402 #ifdef CONFIG_IP_ROUTE_CLASSID
1403 #ifdef CONFIG_IP_MULTIPLE_TABLES
1404 set_class_tag(rt, res->tclassid);
1405 #endif
1406 set_class_tag(rt, itag);
1407 #endif
1408 }
1409
1410 static struct rtable *rt_dst_alloc(struct net_device *dev,
1411 bool nopolicy, bool noxfrm, bool will_cache)
1412 {
1413 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1414 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1415 (nopolicy ? DST_NOPOLICY : 0) |
1416 (noxfrm ? DST_NOXFRM : 0));
1417 }
1418
1419 /* called in rcu_read_lock() section */
1420 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1421 u8 tos, struct net_device *dev, int our)
1422 {
1423 struct rtable *rth;
1424 struct in_device *in_dev = __in_dev_get_rcu(dev);
1425 u32 itag = 0;
1426 int err;
1427
1428 /* Primary sanity checks. */
1429
1430 if (in_dev == NULL)
1431 return -EINVAL;
1432
1433 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1434 skb->protocol != htons(ETH_P_IP))
1435 goto e_inval;
1436
1437 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1438 if (ipv4_is_loopback(saddr))
1439 goto e_inval;
1440
1441 if (ipv4_is_zeronet(saddr)) {
1442 if (!ipv4_is_local_multicast(daddr))
1443 goto e_inval;
1444 } else {
1445 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1446 in_dev, &itag);
1447 if (err < 0)
1448 goto e_err;
1449 }
1450 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1451 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1452 if (!rth)
1453 goto e_nobufs;
1454
1455 #ifdef CONFIG_IP_ROUTE_CLASSID
1456 rth->dst.tclassid = itag;
1457 #endif
1458 rth->dst.output = ip_rt_bug;
1459
1460 rth->rt_genid = rt_genid_ipv4(dev_net(dev));
1461 rth->rt_flags = RTCF_MULTICAST;
1462 rth->rt_type = RTN_MULTICAST;
1463 rth->rt_is_input= 1;
1464 rth->rt_iif = 0;
1465 rth->rt_pmtu = 0;
1466 rth->rt_gateway = 0;
1467 rth->rt_uses_gateway = 0;
1468 INIT_LIST_HEAD(&rth->rt_uncached);
1469 if (our) {
1470 rth->dst.input= ip_local_deliver;
1471 rth->rt_flags |= RTCF_LOCAL;
1472 }
1473
1474 #ifdef CONFIG_IP_MROUTE
1475 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1476 rth->dst.input = ip_mr_input;
1477 #endif
1478 RT_CACHE_STAT_INC(in_slow_mc);
1479
1480 skb_dst_set(skb, &rth->dst);
1481 return 0;
1482
1483 e_nobufs:
1484 return -ENOBUFS;
1485 e_inval:
1486 return -EINVAL;
1487 e_err:
1488 return err;
1489 }
1490
1491
1492 static void ip_handle_martian_source(struct net_device *dev,
1493 struct in_device *in_dev,
1494 struct sk_buff *skb,
1495 __be32 daddr,
1496 __be32 saddr)
1497 {
1498 RT_CACHE_STAT_INC(in_martian_src);
1499 #ifdef CONFIG_IP_ROUTE_VERBOSE
1500 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1501 /*
1502 * RFC1812 recommendation, if source is martian,
1503 * the only hint is MAC header.
1504 */
1505 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1506 &daddr, &saddr, dev->name);
1507 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1508 print_hex_dump(KERN_WARNING, "ll header: ",
1509 DUMP_PREFIX_OFFSET, 16, 1,
1510 skb_mac_header(skb),
1511 dev->hard_header_len, true);
1512 }
1513 }
1514 #endif
1515 }
1516
1517 /* called in rcu_read_lock() section */
1518 static int __mkroute_input(struct sk_buff *skb,
1519 const struct fib_result *res,
1520 struct in_device *in_dev,
1521 __be32 daddr, __be32 saddr, u32 tos)
1522 {
1523 struct fib_nh_exception *fnhe;
1524 struct rtable *rth;
1525 int err;
1526 struct in_device *out_dev;
1527 unsigned int flags = 0;
1528 bool do_cache;
1529 u32 itag;
1530
1531 /* get a working reference to the output device */
1532 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1533 if (out_dev == NULL) {
1534 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1535 return -EINVAL;
1536 }
1537
1538 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1539 in_dev->dev, in_dev, &itag);
1540 if (err < 0) {
1541 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1542 saddr);
1543
1544 goto cleanup;
1545 }
1546
1547 do_cache = res->fi && !itag;
1548 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1549 (IN_DEV_SHARED_MEDIA(out_dev) ||
1550 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) {
1551 flags |= RTCF_DOREDIRECT;
1552 do_cache = false;
1553 }
1554
1555 if (skb->protocol != htons(ETH_P_IP)) {
1556 /* Not IP (i.e. ARP). Do not create route, if it is
1557 * invalid for proxy arp. DNAT routes are always valid.
1558 *
1559 * Proxy arp feature have been extended to allow, ARP
1560 * replies back to the same interface, to support
1561 * Private VLAN switch technologies. See arp.c.
1562 */
1563 if (out_dev == in_dev &&
1564 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1565 err = -EINVAL;
1566 goto cleanup;
1567 }
1568 }
1569
1570 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1571 if (do_cache) {
1572 if (fnhe != NULL)
1573 rth = rcu_dereference(fnhe->fnhe_rth_input);
1574 else
1575 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1576
1577 if (rt_cache_valid(rth)) {
1578 skb_dst_set_noref(skb, &rth->dst);
1579 goto out;
1580 }
1581 }
1582
1583 rth = rt_dst_alloc(out_dev->dev,
1584 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1585 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1586 if (!rth) {
1587 err = -ENOBUFS;
1588 goto cleanup;
1589 }
1590
1591 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev));
1592 rth->rt_flags = flags;
1593 rth->rt_type = res->type;
1594 rth->rt_is_input = 1;
1595 rth->rt_iif = 0;
1596 rth->rt_pmtu = 0;
1597 rth->rt_gateway = 0;
1598 rth->rt_uses_gateway = 0;
1599 INIT_LIST_HEAD(&rth->rt_uncached);
1600
1601 rth->dst.input = ip_forward;
1602 rth->dst.output = ip_output;
1603
1604 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1605 skb_dst_set(skb, &rth->dst);
1606 out:
1607 err = 0;
1608 cleanup:
1609 return err;
1610 }
1611
1612 static int ip_mkroute_input(struct sk_buff *skb,
1613 struct fib_result *res,
1614 const struct flowi4 *fl4,
1615 struct in_device *in_dev,
1616 __be32 daddr, __be32 saddr, u32 tos)
1617 {
1618 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1619 if (res->fi && res->fi->fib_nhs > 1)
1620 fib_select_multipath(res);
1621 #endif
1622
1623 /* create a routing cache entry */
1624 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1625 }
1626
1627 /*
1628 * NOTE. We drop all the packets that has local source
1629 * addresses, because every properly looped back packet
1630 * must have correct destination already attached by output routine.
1631 *
1632 * Such approach solves two big problems:
1633 * 1. Not simplex devices are handled properly.
1634 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1635 * called with rcu_read_lock()
1636 */
1637
1638 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1639 u8 tos, struct net_device *dev)
1640 {
1641 struct fib_result res;
1642 struct in_device *in_dev = __in_dev_get_rcu(dev);
1643 struct flowi4 fl4;
1644 unsigned int flags = 0;
1645 u32 itag = 0;
1646 struct rtable *rth;
1647 int err = -EINVAL;
1648 struct net *net = dev_net(dev);
1649 bool do_cache;
1650
1651 /* IP on this device is disabled. */
1652
1653 if (!in_dev)
1654 goto out;
1655
1656 /* Check for the most weird martians, which can be not detected
1657 by fib_lookup.
1658 */
1659
1660 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1661 goto martian_source;
1662
1663 res.fi = NULL;
1664 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1665 goto brd_input;
1666
1667 /* Accept zero addresses only to limited broadcast;
1668 * I even do not know to fix it or not. Waiting for complains :-)
1669 */
1670 if (ipv4_is_zeronet(saddr))
1671 goto martian_source;
1672
1673 if (ipv4_is_zeronet(daddr))
1674 goto martian_destination;
1675
1676 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1677 * and call it once if daddr or/and saddr are loopback addresses
1678 */
1679 if (ipv4_is_loopback(daddr)) {
1680 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1681 goto martian_destination;
1682 } else if (ipv4_is_loopback(saddr)) {
1683 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1684 goto martian_source;
1685 }
1686
1687 /*
1688 * Now we are ready to route packet.
1689 */
1690 fl4.flowi4_oif = 0;
1691 fl4.flowi4_iif = dev->ifindex;
1692 fl4.flowi4_mark = skb->mark;
1693 fl4.flowi4_tos = tos;
1694 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1695 fl4.daddr = daddr;
1696 fl4.saddr = saddr;
1697 err = fib_lookup(net, &fl4, &res);
1698 if (err != 0)
1699 goto no_route;
1700
1701 RT_CACHE_STAT_INC(in_slow_tot);
1702
1703 if (res.type == RTN_BROADCAST)
1704 goto brd_input;
1705
1706 if (res.type == RTN_LOCAL) {
1707 err = fib_validate_source(skb, saddr, daddr, tos,
1708 LOOPBACK_IFINDEX,
1709 dev, in_dev, &itag);
1710 if (err < 0)
1711 goto martian_source_keep_err;
1712 goto local_input;
1713 }
1714
1715 if (!IN_DEV_FORWARD(in_dev))
1716 goto no_route;
1717 if (res.type != RTN_UNICAST)
1718 goto martian_destination;
1719
1720 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1721 out: return err;
1722
1723 brd_input:
1724 if (skb->protocol != htons(ETH_P_IP))
1725 goto e_inval;
1726
1727 if (!ipv4_is_zeronet(saddr)) {
1728 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1729 in_dev, &itag);
1730 if (err < 0)
1731 goto martian_source_keep_err;
1732 }
1733 flags |= RTCF_BROADCAST;
1734 res.type = RTN_BROADCAST;
1735 RT_CACHE_STAT_INC(in_brd);
1736
1737 local_input:
1738 do_cache = false;
1739 if (res.fi) {
1740 if (!itag) {
1741 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1742 if (rt_cache_valid(rth)) {
1743 skb_dst_set_noref(skb, &rth->dst);
1744 err = 0;
1745 goto out;
1746 }
1747 do_cache = true;
1748 }
1749 }
1750
1751 rth = rt_dst_alloc(net->loopback_dev,
1752 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1753 if (!rth)
1754 goto e_nobufs;
1755
1756 rth->dst.input= ip_local_deliver;
1757 rth->dst.output= ip_rt_bug;
1758 #ifdef CONFIG_IP_ROUTE_CLASSID
1759 rth->dst.tclassid = itag;
1760 #endif
1761
1762 rth->rt_genid = rt_genid_ipv4(net);
1763 rth->rt_flags = flags|RTCF_LOCAL;
1764 rth->rt_type = res.type;
1765 rth->rt_is_input = 1;
1766 rth->rt_iif = 0;
1767 rth->rt_pmtu = 0;
1768 rth->rt_gateway = 0;
1769 rth->rt_uses_gateway = 0;
1770 INIT_LIST_HEAD(&rth->rt_uncached);
1771 if (res.type == RTN_UNREACHABLE) {
1772 rth->dst.input= ip_error;
1773 rth->dst.error= -err;
1774 rth->rt_flags &= ~RTCF_LOCAL;
1775 }
1776 if (do_cache) {
1777 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1778 rth->dst.flags |= DST_NOCACHE;
1779 rt_add_uncached_list(rth);
1780 }
1781 }
1782 skb_dst_set(skb, &rth->dst);
1783 err = 0;
1784 goto out;
1785
1786 no_route:
1787 RT_CACHE_STAT_INC(in_no_route);
1788 res.type = RTN_UNREACHABLE;
1789 if (err == -ESRCH)
1790 err = -ENETUNREACH;
1791 goto local_input;
1792
1793 /*
1794 * Do not cache martian addresses: they should be logged (RFC1812)
1795 */
1796 martian_destination:
1797 RT_CACHE_STAT_INC(in_martian_dst);
1798 #ifdef CONFIG_IP_ROUTE_VERBOSE
1799 if (IN_DEV_LOG_MARTIANS(in_dev))
1800 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1801 &daddr, &saddr, dev->name);
1802 #endif
1803
1804 e_inval:
1805 err = -EINVAL;
1806 goto out;
1807
1808 e_nobufs:
1809 err = -ENOBUFS;
1810 goto out;
1811
1812 martian_source:
1813 err = -EINVAL;
1814 martian_source_keep_err:
1815 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1816 goto out;
1817 }
1818
1819 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1820 u8 tos, struct net_device *dev)
1821 {
1822 int res;
1823
1824 rcu_read_lock();
1825
1826 /* Multicast recognition logic is moved from route cache to here.
1827 The problem was that too many Ethernet cards have broken/missing
1828 hardware multicast filters :-( As result the host on multicasting
1829 network acquires a lot of useless route cache entries, sort of
1830 SDR messages from all the world. Now we try to get rid of them.
1831 Really, provided software IP multicast filter is organized
1832 reasonably (at least, hashed), it does not result in a slowdown
1833 comparing with route cache reject entries.
1834 Note, that multicast routers are not affected, because
1835 route cache entry is created eventually.
1836 */
1837 if (ipv4_is_multicast(daddr)) {
1838 struct in_device *in_dev = __in_dev_get_rcu(dev);
1839
1840 if (in_dev) {
1841 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1842 ip_hdr(skb)->protocol);
1843 if (our
1844 #ifdef CONFIG_IP_MROUTE
1845 ||
1846 (!ipv4_is_local_multicast(daddr) &&
1847 IN_DEV_MFORWARD(in_dev))
1848 #endif
1849 ) {
1850 int res = ip_route_input_mc(skb, daddr, saddr,
1851 tos, dev, our);
1852 rcu_read_unlock();
1853 return res;
1854 }
1855 }
1856 rcu_read_unlock();
1857 return -EINVAL;
1858 }
1859 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1860 rcu_read_unlock();
1861 return res;
1862 }
1863 EXPORT_SYMBOL(ip_route_input_noref);
1864
1865 /* called with rcu_read_lock() */
1866 static struct rtable *__mkroute_output(const struct fib_result *res,
1867 const struct flowi4 *fl4, int orig_oif,
1868 struct net_device *dev_out,
1869 unsigned int flags)
1870 {
1871 struct fib_info *fi = res->fi;
1872 struct fib_nh_exception *fnhe;
1873 struct in_device *in_dev;
1874 u16 type = res->type;
1875 struct rtable *rth;
1876 bool do_cache;
1877
1878 in_dev = __in_dev_get_rcu(dev_out);
1879 if (!in_dev)
1880 return ERR_PTR(-EINVAL);
1881
1882 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1883 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1884 return ERR_PTR(-EINVAL);
1885
1886 if (ipv4_is_lbcast(fl4->daddr))
1887 type = RTN_BROADCAST;
1888 else if (ipv4_is_multicast(fl4->daddr))
1889 type = RTN_MULTICAST;
1890 else if (ipv4_is_zeronet(fl4->daddr))
1891 return ERR_PTR(-EINVAL);
1892
1893 if (dev_out->flags & IFF_LOOPBACK)
1894 flags |= RTCF_LOCAL;
1895
1896 do_cache = true;
1897 if (type == RTN_BROADCAST) {
1898 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1899 fi = NULL;
1900 } else if (type == RTN_MULTICAST) {
1901 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1902 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1903 fl4->flowi4_proto))
1904 flags &= ~RTCF_LOCAL;
1905 else
1906 do_cache = false;
1907 /* If multicast route do not exist use
1908 * default one, but do not gateway in this case.
1909 * Yes, it is hack.
1910 */
1911 if (fi && res->prefixlen < 4)
1912 fi = NULL;
1913 }
1914
1915 fnhe = NULL;
1916 do_cache &= fi != NULL;
1917 if (do_cache) {
1918 struct rtable __rcu **prth;
1919 struct fib_nh *nh = &FIB_RES_NH(*res);
1920
1921 fnhe = find_exception(nh, fl4->daddr);
1922 if (fnhe)
1923 prth = &fnhe->fnhe_rth_output;
1924 else {
1925 if (unlikely(fl4->flowi4_flags &
1926 FLOWI_FLAG_KNOWN_NH &&
1927 !(nh->nh_gw &&
1928 nh->nh_scope == RT_SCOPE_LINK))) {
1929 do_cache = false;
1930 goto add;
1931 }
1932 prth = __this_cpu_ptr(nh->nh_pcpu_rth_output);
1933 }
1934 rth = rcu_dereference(*prth);
1935 if (rt_cache_valid(rth)) {
1936 dst_hold(&rth->dst);
1937 return rth;
1938 }
1939 }
1940
1941 add:
1942 rth = rt_dst_alloc(dev_out,
1943 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1944 IN_DEV_CONF_GET(in_dev, NOXFRM),
1945 do_cache);
1946 if (!rth)
1947 return ERR_PTR(-ENOBUFS);
1948
1949 rth->dst.output = ip_output;
1950
1951 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out));
1952 rth->rt_flags = flags;
1953 rth->rt_type = type;
1954 rth->rt_is_input = 0;
1955 rth->rt_iif = orig_oif ? : 0;
1956 rth->rt_pmtu = 0;
1957 rth->rt_gateway = 0;
1958 rth->rt_uses_gateway = 0;
1959 INIT_LIST_HEAD(&rth->rt_uncached);
1960
1961 RT_CACHE_STAT_INC(out_slow_tot);
1962
1963 if (flags & RTCF_LOCAL)
1964 rth->dst.input = ip_local_deliver;
1965 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1966 if (flags & RTCF_LOCAL &&
1967 !(dev_out->flags & IFF_LOOPBACK)) {
1968 rth->dst.output = ip_mc_output;
1969 RT_CACHE_STAT_INC(out_slow_mc);
1970 }
1971 #ifdef CONFIG_IP_MROUTE
1972 if (type == RTN_MULTICAST) {
1973 if (IN_DEV_MFORWARD(in_dev) &&
1974 !ipv4_is_local_multicast(fl4->daddr)) {
1975 rth->dst.input = ip_mr_input;
1976 rth->dst.output = ip_mc_output;
1977 }
1978 }
1979 #endif
1980 }
1981
1982 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1983
1984 return rth;
1985 }
1986
1987 /*
1988 * Major route resolver routine.
1989 */
1990
1991 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1992 {
1993 struct net_device *dev_out = NULL;
1994 __u8 tos = RT_FL_TOS(fl4);
1995 unsigned int flags = 0;
1996 struct fib_result res;
1997 struct rtable *rth;
1998 int orig_oif;
1999
2000 res.tclassid = 0;
2001 res.fi = NULL;
2002 res.table = NULL;
2003
2004 orig_oif = fl4->flowi4_oif;
2005
2006 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2007 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2008 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2009 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2010
2011 rcu_read_lock();
2012 if (fl4->saddr) {
2013 rth = ERR_PTR(-EINVAL);
2014 if (ipv4_is_multicast(fl4->saddr) ||
2015 ipv4_is_lbcast(fl4->saddr) ||
2016 ipv4_is_zeronet(fl4->saddr))
2017 goto out;
2018
2019 /* I removed check for oif == dev_out->oif here.
2020 It was wrong for two reasons:
2021 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2022 is assigned to multiple interfaces.
2023 2. Moreover, we are allowed to send packets with saddr
2024 of another iface. --ANK
2025 */
2026
2027 if (fl4->flowi4_oif == 0 &&
2028 (ipv4_is_multicast(fl4->daddr) ||
2029 ipv4_is_lbcast(fl4->daddr))) {
2030 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2031 dev_out = __ip_dev_find(net, fl4->saddr, false);
2032 if (dev_out == NULL)
2033 goto out;
2034
2035 /* Special hack: user can direct multicasts
2036 and limited broadcast via necessary interface
2037 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2038 This hack is not just for fun, it allows
2039 vic,vat and friends to work.
2040 They bind socket to loopback, set ttl to zero
2041 and expect that it will work.
2042 From the viewpoint of routing cache they are broken,
2043 because we are not allowed to build multicast path
2044 with loopback source addr (look, routing cache
2045 cannot know, that ttl is zero, so that packet
2046 will not leave this host and route is valid).
2047 Luckily, this hack is good workaround.
2048 */
2049
2050 fl4->flowi4_oif = dev_out->ifindex;
2051 goto make_route;
2052 }
2053
2054 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2055 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2056 if (!__ip_dev_find(net, fl4->saddr, false))
2057 goto out;
2058 }
2059 }
2060
2061
2062 if (fl4->flowi4_oif) {
2063 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2064 rth = ERR_PTR(-ENODEV);
2065 if (dev_out == NULL)
2066 goto out;
2067
2068 /* RACE: Check return value of inet_select_addr instead. */
2069 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2070 rth = ERR_PTR(-ENETUNREACH);
2071 goto out;
2072 }
2073 if (ipv4_is_local_multicast(fl4->daddr) ||
2074 ipv4_is_lbcast(fl4->daddr)) {
2075 if (!fl4->saddr)
2076 fl4->saddr = inet_select_addr(dev_out, 0,
2077 RT_SCOPE_LINK);
2078 goto make_route;
2079 }
2080 if (!fl4->saddr) {
2081 if (ipv4_is_multicast(fl4->daddr))
2082 fl4->saddr = inet_select_addr(dev_out, 0,
2083 fl4->flowi4_scope);
2084 else if (!fl4->daddr)
2085 fl4->saddr = inet_select_addr(dev_out, 0,
2086 RT_SCOPE_HOST);
2087 }
2088 }
2089
2090 if (!fl4->daddr) {
2091 fl4->daddr = fl4->saddr;
2092 if (!fl4->daddr)
2093 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2094 dev_out = net->loopback_dev;
2095 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2096 res.type = RTN_LOCAL;
2097 flags |= RTCF_LOCAL;
2098 goto make_route;
2099 }
2100
2101 if (fib_lookup(net, fl4, &res)) {
2102 res.fi = NULL;
2103 res.table = NULL;
2104 if (fl4->flowi4_oif) {
2105 /* Apparently, routing tables are wrong. Assume,
2106 that the destination is on link.
2107
2108 WHY? DW.
2109 Because we are allowed to send to iface
2110 even if it has NO routes and NO assigned
2111 addresses. When oif is specified, routing
2112 tables are looked up with only one purpose:
2113 to catch if destination is gatewayed, rather than
2114 direct. Moreover, if MSG_DONTROUTE is set,
2115 we send packet, ignoring both routing tables
2116 and ifaddr state. --ANK
2117
2118
2119 We could make it even if oif is unknown,
2120 likely IPv6, but we do not.
2121 */
2122
2123 if (fl4->saddr == 0)
2124 fl4->saddr = inet_select_addr(dev_out, 0,
2125 RT_SCOPE_LINK);
2126 res.type = RTN_UNICAST;
2127 goto make_route;
2128 }
2129 rth = ERR_PTR(-ENETUNREACH);
2130 goto out;
2131 }
2132
2133 if (res.type == RTN_LOCAL) {
2134 if (!fl4->saddr) {
2135 if (res.fi->fib_prefsrc)
2136 fl4->saddr = res.fi->fib_prefsrc;
2137 else
2138 fl4->saddr = fl4->daddr;
2139 }
2140 dev_out = net->loopback_dev;
2141 fl4->flowi4_oif = dev_out->ifindex;
2142 flags |= RTCF_LOCAL;
2143 goto make_route;
2144 }
2145
2146 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2147 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2148 fib_select_multipath(&res);
2149 else
2150 #endif
2151 if (!res.prefixlen &&
2152 res.table->tb_num_default > 1 &&
2153 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2154 fib_select_default(&res);
2155
2156 if (!fl4->saddr)
2157 fl4->saddr = FIB_RES_PREFSRC(net, res);
2158
2159 dev_out = FIB_RES_DEV(res);
2160 fl4->flowi4_oif = dev_out->ifindex;
2161
2162
2163 make_route:
2164 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2165
2166 out:
2167 rcu_read_unlock();
2168 return rth;
2169 }
2170 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2171
2172 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2173 {
2174 return NULL;
2175 }
2176
2177 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2178 {
2179 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2180
2181 return mtu ? : dst->dev->mtu;
2182 }
2183
2184 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2185 struct sk_buff *skb, u32 mtu)
2186 {
2187 }
2188
2189 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2190 struct sk_buff *skb)
2191 {
2192 }
2193
2194 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2195 unsigned long old)
2196 {
2197 return NULL;
2198 }
2199
2200 static struct dst_ops ipv4_dst_blackhole_ops = {
2201 .family = AF_INET,
2202 .protocol = cpu_to_be16(ETH_P_IP),
2203 .check = ipv4_blackhole_dst_check,
2204 .mtu = ipv4_blackhole_mtu,
2205 .default_advmss = ipv4_default_advmss,
2206 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2207 .redirect = ipv4_rt_blackhole_redirect,
2208 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2209 .neigh_lookup = ipv4_neigh_lookup,
2210 };
2211
2212 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2213 {
2214 struct rtable *ort = (struct rtable *) dst_orig;
2215 struct rtable *rt;
2216
2217 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2218 if (rt) {
2219 struct dst_entry *new = &rt->dst;
2220
2221 new->__use = 1;
2222 new->input = dst_discard;
2223 new->output = dst_discard;
2224
2225 new->dev = ort->dst.dev;
2226 if (new->dev)
2227 dev_hold(new->dev);
2228
2229 rt->rt_is_input = ort->rt_is_input;
2230 rt->rt_iif = ort->rt_iif;
2231 rt->rt_pmtu = ort->rt_pmtu;
2232
2233 rt->rt_genid = rt_genid_ipv4(net);
2234 rt->rt_flags = ort->rt_flags;
2235 rt->rt_type = ort->rt_type;
2236 rt->rt_gateway = ort->rt_gateway;
2237 rt->rt_uses_gateway = ort->rt_uses_gateway;
2238
2239 INIT_LIST_HEAD(&rt->rt_uncached);
2240
2241 dst_free(new);
2242 }
2243
2244 dst_release(dst_orig);
2245
2246 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2247 }
2248
2249 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2250 struct sock *sk)
2251 {
2252 struct rtable *rt = __ip_route_output_key(net, flp4);
2253
2254 if (IS_ERR(rt))
2255 return rt;
2256
2257 if (flp4->flowi4_proto)
2258 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2259 flowi4_to_flowi(flp4),
2260 sk, 0);
2261
2262 return rt;
2263 }
2264 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2265
2266 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2267 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2268 u32 seq, int event, int nowait, unsigned int flags)
2269 {
2270 struct rtable *rt = skb_rtable(skb);
2271 struct rtmsg *r;
2272 struct nlmsghdr *nlh;
2273 unsigned long expires = 0;
2274 u32 error;
2275 u32 metrics[RTAX_MAX];
2276
2277 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2278 if (nlh == NULL)
2279 return -EMSGSIZE;
2280
2281 r = nlmsg_data(nlh);
2282 r->rtm_family = AF_INET;
2283 r->rtm_dst_len = 32;
2284 r->rtm_src_len = 0;
2285 r->rtm_tos = fl4->flowi4_tos;
2286 r->rtm_table = RT_TABLE_MAIN;
2287 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2288 goto nla_put_failure;
2289 r->rtm_type = rt->rt_type;
2290 r->rtm_scope = RT_SCOPE_UNIVERSE;
2291 r->rtm_protocol = RTPROT_UNSPEC;
2292 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2293 if (rt->rt_flags & RTCF_NOTIFY)
2294 r->rtm_flags |= RTM_F_NOTIFY;
2295
2296 if (nla_put_be32(skb, RTA_DST, dst))
2297 goto nla_put_failure;
2298 if (src) {
2299 r->rtm_src_len = 32;
2300 if (nla_put_be32(skb, RTA_SRC, src))
2301 goto nla_put_failure;
2302 }
2303 if (rt->dst.dev &&
2304 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2305 goto nla_put_failure;
2306 #ifdef CONFIG_IP_ROUTE_CLASSID
2307 if (rt->dst.tclassid &&
2308 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2309 goto nla_put_failure;
2310 #endif
2311 if (!rt_is_input_route(rt) &&
2312 fl4->saddr != src) {
2313 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2314 goto nla_put_failure;
2315 }
2316 if (rt->rt_uses_gateway &&
2317 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2318 goto nla_put_failure;
2319
2320 expires = rt->dst.expires;
2321 if (expires) {
2322 unsigned long now = jiffies;
2323
2324 if (time_before(now, expires))
2325 expires -= now;
2326 else
2327 expires = 0;
2328 }
2329
2330 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2331 if (rt->rt_pmtu && expires)
2332 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2333 if (rtnetlink_put_metrics(skb, metrics) < 0)
2334 goto nla_put_failure;
2335
2336 if (fl4->flowi4_mark &&
2337 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2338 goto nla_put_failure;
2339
2340 error = rt->dst.error;
2341
2342 if (rt_is_input_route(rt)) {
2343 #ifdef CONFIG_IP_MROUTE
2344 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2345 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2346 int err = ipmr_get_route(net, skb,
2347 fl4->saddr, fl4->daddr,
2348 r, nowait);
2349 if (err <= 0) {
2350 if (!nowait) {
2351 if (err == 0)
2352 return 0;
2353 goto nla_put_failure;
2354 } else {
2355 if (err == -EMSGSIZE)
2356 goto nla_put_failure;
2357 error = err;
2358 }
2359 }
2360 } else
2361 #endif
2362 if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
2363 goto nla_put_failure;
2364 }
2365
2366 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2367 goto nla_put_failure;
2368
2369 return nlmsg_end(skb, nlh);
2370
2371 nla_put_failure:
2372 nlmsg_cancel(skb, nlh);
2373 return -EMSGSIZE;
2374 }
2375
2376 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2377 {
2378 struct net *net = sock_net(in_skb->sk);
2379 struct rtmsg *rtm;
2380 struct nlattr *tb[RTA_MAX+1];
2381 struct rtable *rt = NULL;
2382 struct flowi4 fl4;
2383 __be32 dst = 0;
2384 __be32 src = 0;
2385 u32 iif;
2386 int err;
2387 int mark;
2388 struct sk_buff *skb;
2389
2390 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2391 if (err < 0)
2392 goto errout;
2393
2394 rtm = nlmsg_data(nlh);
2395
2396 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2397 if (skb == NULL) {
2398 err = -ENOBUFS;
2399 goto errout;
2400 }
2401
2402 /* Reserve room for dummy headers, this skb can pass
2403 through good chunk of routing engine.
2404 */
2405 skb_reset_mac_header(skb);
2406 skb_reset_network_header(skb);
2407
2408 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2409 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2410 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2411
2412 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2413 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2414 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2415 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2416
2417 memset(&fl4, 0, sizeof(fl4));
2418 fl4.daddr = dst;
2419 fl4.saddr = src;
2420 fl4.flowi4_tos = rtm->rtm_tos;
2421 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2422 fl4.flowi4_mark = mark;
2423
2424 if (iif) {
2425 struct net_device *dev;
2426
2427 dev = __dev_get_by_index(net, iif);
2428 if (dev == NULL) {
2429 err = -ENODEV;
2430 goto errout_free;
2431 }
2432
2433 skb->protocol = htons(ETH_P_IP);
2434 skb->dev = dev;
2435 skb->mark = mark;
2436 local_bh_disable();
2437 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2438 local_bh_enable();
2439
2440 rt = skb_rtable(skb);
2441 if (err == 0 && rt->dst.error)
2442 err = -rt->dst.error;
2443 } else {
2444 rt = ip_route_output_key(net, &fl4);
2445
2446 err = 0;
2447 if (IS_ERR(rt))
2448 err = PTR_ERR(rt);
2449 }
2450
2451 if (err)
2452 goto errout_free;
2453
2454 skb_dst_set(skb, &rt->dst);
2455 if (rtm->rtm_flags & RTM_F_NOTIFY)
2456 rt->rt_flags |= RTCF_NOTIFY;
2457
2458 err = rt_fill_info(net, dst, src, &fl4, skb,
2459 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2460 RTM_NEWROUTE, 0, 0);
2461 if (err <= 0)
2462 goto errout_free;
2463
2464 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2465 errout:
2466 return err;
2467
2468 errout_free:
2469 kfree_skb(skb);
2470 goto errout;
2471 }
2472
2473 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2474 {
2475 return skb->len;
2476 }
2477
2478 void ip_rt_multicast_event(struct in_device *in_dev)
2479 {
2480 rt_cache_flush(dev_net(in_dev->dev));
2481 }
2482
2483 #ifdef CONFIG_SYSCTL
2484 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2485 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2486 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2487 static int ip_rt_gc_elasticity __read_mostly = 8;
2488
2489 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2490 void __user *buffer,
2491 size_t *lenp, loff_t *ppos)
2492 {
2493 struct net *net = (struct net *)__ctl->extra1;
2494
2495 if (write) {
2496 rt_cache_flush(net);
2497 fnhe_genid_bump(net);
2498 return 0;
2499 }
2500
2501 return -EINVAL;
2502 }
2503
2504 static struct ctl_table ipv4_route_table[] = {
2505 {
2506 .procname = "gc_thresh",
2507 .data = &ipv4_dst_ops.gc_thresh,
2508 .maxlen = sizeof(int),
2509 .mode = 0644,
2510 .proc_handler = proc_dointvec,
2511 },
2512 {
2513 .procname = "max_size",
2514 .data = &ip_rt_max_size,
2515 .maxlen = sizeof(int),
2516 .mode = 0644,
2517 .proc_handler = proc_dointvec,
2518 },
2519 {
2520 /* Deprecated. Use gc_min_interval_ms */
2521
2522 .procname = "gc_min_interval",
2523 .data = &ip_rt_gc_min_interval,
2524 .maxlen = sizeof(int),
2525 .mode = 0644,
2526 .proc_handler = proc_dointvec_jiffies,
2527 },
2528 {
2529 .procname = "gc_min_interval_ms",
2530 .data = &ip_rt_gc_min_interval,
2531 .maxlen = sizeof(int),
2532 .mode = 0644,
2533 .proc_handler = proc_dointvec_ms_jiffies,
2534 },
2535 {
2536 .procname = "gc_timeout",
2537 .data = &ip_rt_gc_timeout,
2538 .maxlen = sizeof(int),
2539 .mode = 0644,
2540 .proc_handler = proc_dointvec_jiffies,
2541 },
2542 {
2543 .procname = "gc_interval",
2544 .data = &ip_rt_gc_interval,
2545 .maxlen = sizeof(int),
2546 .mode = 0644,
2547 .proc_handler = proc_dointvec_jiffies,
2548 },
2549 {
2550 .procname = "redirect_load",
2551 .data = &ip_rt_redirect_load,
2552 .maxlen = sizeof(int),
2553 .mode = 0644,
2554 .proc_handler = proc_dointvec,
2555 },
2556 {
2557 .procname = "redirect_number",
2558 .data = &ip_rt_redirect_number,
2559 .maxlen = sizeof(int),
2560 .mode = 0644,
2561 .proc_handler = proc_dointvec,
2562 },
2563 {
2564 .procname = "redirect_silence",
2565 .data = &ip_rt_redirect_silence,
2566 .maxlen = sizeof(int),
2567 .mode = 0644,
2568 .proc_handler = proc_dointvec,
2569 },
2570 {
2571 .procname = "error_cost",
2572 .data = &ip_rt_error_cost,
2573 .maxlen = sizeof(int),
2574 .mode = 0644,
2575 .proc_handler = proc_dointvec,
2576 },
2577 {
2578 .procname = "error_burst",
2579 .data = &ip_rt_error_burst,
2580 .maxlen = sizeof(int),
2581 .mode = 0644,
2582 .proc_handler = proc_dointvec,
2583 },
2584 {
2585 .procname = "gc_elasticity",
2586 .data = &ip_rt_gc_elasticity,
2587 .maxlen = sizeof(int),
2588 .mode = 0644,
2589 .proc_handler = proc_dointvec,
2590 },
2591 {
2592 .procname = "mtu_expires",
2593 .data = &ip_rt_mtu_expires,
2594 .maxlen = sizeof(int),
2595 .mode = 0644,
2596 .proc_handler = proc_dointvec_jiffies,
2597 },
2598 {
2599 .procname = "min_pmtu",
2600 .data = &ip_rt_min_pmtu,
2601 .maxlen = sizeof(int),
2602 .mode = 0644,
2603 .proc_handler = proc_dointvec,
2604 },
2605 {
2606 .procname = "min_adv_mss",
2607 .data = &ip_rt_min_advmss,
2608 .maxlen = sizeof(int),
2609 .mode = 0644,
2610 .proc_handler = proc_dointvec,
2611 },
2612 { }
2613 };
2614
2615 static struct ctl_table ipv4_route_flush_table[] = {
2616 {
2617 .procname = "flush",
2618 .maxlen = sizeof(int),
2619 .mode = 0200,
2620 .proc_handler = ipv4_sysctl_rtcache_flush,
2621 },
2622 { },
2623 };
2624
2625 static __net_init int sysctl_route_net_init(struct net *net)
2626 {
2627 struct ctl_table *tbl;
2628
2629 tbl = ipv4_route_flush_table;
2630 if (!net_eq(net, &init_net)) {
2631 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2632 if (tbl == NULL)
2633 goto err_dup;
2634
2635 /* Don't export sysctls to unprivileged users */
2636 if (net->user_ns != &init_user_ns)
2637 tbl[0].procname = NULL;
2638 }
2639 tbl[0].extra1 = net;
2640
2641 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2642 if (net->ipv4.route_hdr == NULL)
2643 goto err_reg;
2644 return 0;
2645
2646 err_reg:
2647 if (tbl != ipv4_route_flush_table)
2648 kfree(tbl);
2649 err_dup:
2650 return -ENOMEM;
2651 }
2652
2653 static __net_exit void sysctl_route_net_exit(struct net *net)
2654 {
2655 struct ctl_table *tbl;
2656
2657 tbl = net->ipv4.route_hdr->ctl_table_arg;
2658 unregister_net_sysctl_table(net->ipv4.route_hdr);
2659 BUG_ON(tbl == ipv4_route_flush_table);
2660 kfree(tbl);
2661 }
2662
2663 static __net_initdata struct pernet_operations sysctl_route_ops = {
2664 .init = sysctl_route_net_init,
2665 .exit = sysctl_route_net_exit,
2666 };
2667 #endif
2668
2669 static __net_init int rt_genid_init(struct net *net)
2670 {
2671 atomic_set(&net->ipv4.rt_genid, 0);
2672 atomic_set(&net->fnhe_genid, 0);
2673 get_random_bytes(&net->ipv4.dev_addr_genid,
2674 sizeof(net->ipv4.dev_addr_genid));
2675 return 0;
2676 }
2677
2678 static __net_initdata struct pernet_operations rt_genid_ops = {
2679 .init = rt_genid_init,
2680 };
2681
2682 static int __net_init ipv4_inetpeer_init(struct net *net)
2683 {
2684 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2685
2686 if (!bp)
2687 return -ENOMEM;
2688 inet_peer_base_init(bp);
2689 net->ipv4.peers = bp;
2690 return 0;
2691 }
2692
2693 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2694 {
2695 struct inet_peer_base *bp = net->ipv4.peers;
2696
2697 net->ipv4.peers = NULL;
2698 inetpeer_invalidate_tree(bp);
2699 kfree(bp);
2700 }
2701
2702 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2703 .init = ipv4_inetpeer_init,
2704 .exit = ipv4_inetpeer_exit,
2705 };
2706
2707 #ifdef CONFIG_IP_ROUTE_CLASSID
2708 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2709 #endif /* CONFIG_IP_ROUTE_CLASSID */
2710
2711 int __init ip_rt_init(void)
2712 {
2713 int rc = 0;
2714
2715 #ifdef CONFIG_IP_ROUTE_CLASSID
2716 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2717 if (!ip_rt_acct)
2718 panic("IP: failed to allocate ip_rt_acct\n");
2719 #endif
2720
2721 ipv4_dst_ops.kmem_cachep =
2722 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2723 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2724
2725 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2726
2727 if (dst_entries_init(&ipv4_dst_ops) < 0)
2728 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2729
2730 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2731 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2732
2733 ipv4_dst_ops.gc_thresh = ~0;
2734 ip_rt_max_size = INT_MAX;
2735
2736 devinet_init();
2737 ip_fib_init();
2738
2739 if (ip_rt_proc_init())
2740 pr_err("Unable to create route proc files\n");
2741 #ifdef CONFIG_XFRM
2742 xfrm_init();
2743 xfrm4_init();
2744 #endif
2745 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2746
2747 #ifdef CONFIG_SYSCTL
2748 register_pernet_subsys(&sysctl_route_ops);
2749 #endif
2750 register_pernet_subsys(&rt_genid_ops);
2751 register_pernet_subsys(&ipv4_inetpeer_ops);
2752 return rc;
2753 }
2754
2755 #ifdef CONFIG_SYSCTL
2756 /*
2757 * We really need to sanitize the damn ipv4 init order, then all
2758 * this nonsense will go away.
2759 */
2760 void __init ip_static_sysctl_init(void)
2761 {
2762 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2763 }
2764 #endif
Linux kernel - Deliverables
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